Add full datagram support for BSD

Make mg_http_ota_cb public, add /ota endpoints to MCU examples

.github/workflows/nightly.yml

@@ -637,7 +637,6 @@ jobs:
         example:
           - path: micropython/esp32
           - path: esp32/uart-bridge
-          - path: esp32/minimal
     name: ${{ matrix.example.path }}
     env:
       GO: 0

.github/workflows/quicktest.yml

@@ -186,7 +186,6 @@ jobs:
       matrix:
         example:
           - path: esp32/uart-bridge
-          - path: esp32/minimal
     name: ${{ matrix.example.path }}
     env:
       GO: 0

AGENTS.md

@@ -1,8 +1,12 @@
-# Mongoose - Embedded Network Library
+# Mongoose: a full-stack embedded networking library
+
+Mongoose is a full-stack embedded networking library for C/C++: a TCP/IP stack
+with drivers, TLS 1.3, an embedded web server (HTTP, WebSocket), MQTT and
+firmware OTA updates in two files, `mongoose.c` and `mongoose.h`. Mongoose runs on
+STM32, NXP and other microcontrollers, on bare metal or with an RTOS, with no
+external dependencies. Use it for cloud connectivity, device web dashboards,
+secure firmware updates and remote control.
 
-Mongoose is an open source, two-file C networking library and embedded web server for
-microcontrollers that combines TCP/IP stack, HTTP, WebSocket, MQTT, TLS 1.3
-stack, built-in firmware OTA updates, and device-dashboard infrastructure.
 License: GPLv2 or commercial.
 Website: https://mongoose.ws/
 GitHub repo: https://github.com/cesanta/mongoose

README.md

@@ -1,4 +1,4 @@
-# Mongoose - Embedded Web Server / Embedded Network Library
+# Mongoose: a full-stack embedded networking library
 
 [![License: GPLv2/Commercial](https://img.shields.io/badge/License-GPLv2%20or%20Commercial-green.svg)](https://opensource.org/licenses/gpl-2.0.php)
 [![Build Status]( https://github.com/cesanta/mongoose/actions/workflows/quicktest.yml/badge.svg)](https://github.com/cesanta/mongoose/actions)
@@ -7,11 +7,17 @@
 
 <img src="https://mongoose.ws/images/logo.svg" width="48" height="48"
 align="left" style="float:left;" />
-Two files. Drop `mongoose.c` and `mongoose.h` into any C/C++ project and get a
-full network stack — HTTP, WebSocket, MQTT, TLS, firmware OTA
-updates, device dashboard — on any microcontroller or desktop OS.
+Mongoose is a full-stack embedded networking library for C/C++: a TCP/IP stack
+with drivers, TLS 1.3, an embedded web server (HTTP, WebSocket), MQTT and
+firmware OTA updates in two files, `mongoose.c` and `mongoose.h`. Mongoose runs on
+STM32, NXP and other microcontrollers, on bare metal or with an RTOS, with no
+external dependencies. Use it for cloud connectivity, device web dashboards,
+secure firmware updates and remote control.
 
-On the market since 2004, used by vast number of open source and commercial
+Use it instead of lwIP + mbedTLS + httpd + an MQTT client + OTA glue code, or
+run it on top of lwIP or Zephyr.
+
+On the market since 2004, used by a vast number of open source and commercial
 products - it even runs on the International Space Station! Features include:
 
 - Cross-platform:
@@ -24,7 +30,7 @@ products - it even runs on the International Space Station! Features include:
 - Source code is both ISO C and ISO C++ compliant
 - Very easy to integrate
 - Own TCP/IP stack for bare metal / RTOS, or run on top of any existing one (lwIP, Zephyr, ...)
-- Built-in TLS 1.3 ECC stack. Also can use external TLS libraries - mbedTLS, OpenSSL, or other
+- Built-in TLS 1.3 stack. Also can use external TLS libraries - mbedTLS, OpenSSL, or other
 - Does not depend on any other software to implement networking
 - Built-in firmware updates for STM32 H5, STM32 H7, NXP IMXRT, RP2040/2350, ESP32 and more
 - Commercial support with proactive security updates; [CRA-compliant](https://mongoose.ws/security/cra-compliance/)
@@ -35,8 +41,32 @@ See https://mongoose.ws/ for complete documentation, videos, case studies, etc.
 
 ## Supported platforms
 
-Mongoose can work on top of any TCP/IP stack that supports BSD sockets API.
-Platforms supported by the 3rd party TCP/IP stacks:
+Mongoose has its own built-in TCP/IP stack with drivers, so it needs no
+additional software to implement networking. The built-in stack runs on bare
+metal and under any RTOS. Platforms supported by the Mongoose built-in TCP/IP
+stack:
+
+| MCU | Connectivity | Notes |
+| :-- | :----------- | :---- |
+| **STM32** | Built-in Ethernet | Ethernet-capable STM32F, STM32H5, STM32H7, STM32N6, STM32C5 variants |
+| **NXP i.MX RT** | Built-in Ethernet | RT102x, RT104x, RT105x, RT106x, RT117x, RT118x (NETC) |
+| **NXP MCX** | Built-in Ethernet | MCXN94x, MCXE247 |
+| **NXP RW612** | Eth, WiFi, 802.15.4 | Separate Ethernet and radio drivers |
+| **Microchip ATSAME54** | Built-in Ethernet | GMAC driver |
+| **Renesas RA** | Built-in Ethernet | RA6M, RA8M |
+| **Infineon XMC** | Built-in Ethernet | XMC4, XMC7 |
+| **Texas Instruments** | Built-in Ethernet | TM4C, TMS570 |
+| **RP2040, RP2350, STM32, others** | CYW43xx Wi-Fi chips | SPI or SDIO; Pico W, Pico 2 W, Pico RM2, Arduino Portenta H7 |
+| **STM32, others** | ST67W6 Wi-Fi modules | SPI; for example, STM32U5 with the ST67W611M1 module |
+| **MCUs with an NXP Wi-Fi SDK port** | NXP Wi-Fi | Requires the SDK's Wi-Fi port implementing the driver's network hooks |
+| **NXP MCXW71** | Built-in 802.15.4 radio | IPv4 over IEEE 802.15.4 |
+| **NXP RW612** | Built-in 802.15.4 radio | IPv4 over IEEE 802.15.4; requires NXP radio firmware |
+| **Any MCU with SPI** | W5500 or W5100 Ethernet chips | External Wiznet MAC+PHY |
+| **MCUs connected to a cellular modem** | Cellular | AT commands and PPP; for example, SIM800 |
+| **MCUs with CMSIS Ethernet drivers** | Ethernet via CMSIS-Driver | Requires CMSIS Ethernet MAC and PHY drivers |
+
+Mongoose can also run on top of any TCP/IP stack that supports the BSD
+sockets API. Platforms supported via 3rd party TCP/IP stacks:
 
 | TCP/IP stack    | Notes |
 | :-------------- | :------- |
@@ -45,23 +75,6 @@ Platforms supported by the 3rd party TCP/IP stacks:
 | **Other**       | Any other TCP/IP stack that supports BSD socket API, for example Amazon FreeRTOS-TCP |
 | **Linux, Mac, Windows**   | Workstations, server, single board computers, embedded Linux devices running on MPUs or FPGAs |
 
-Optionally, Mongoose provides its own built-in TCP/IP stack, eliminating the
-need for additional software to implement networking functionality. The
-built-in stack supports operation in both bare-metal and RTOS environments.
-Platforms supported by the Mongoose built-in TCP/IP stack:
-
-| Hardware       | Notes |
-| :------------- | :------- |
-| **STM32**      | All STM32 MCUs with built-in Ethernet: STM32Fxx, STM32H5xx, STM32H7xx |
-| **NXP**        |  All NXP MCUs with built-in Ethernet: IMXRT102x, IMXRT104x, IMXRT105x, IMXRT106x, IMXRT117x, RW612, MCXN94x   |
-| **Microchip**  | ATSAME54 MCUs with built-int Ethernet  |
-| **Renesas**    | RA5M, RA6M, RA8M MCUs with built-in Ethernet    |
-| **Infineon**   | XMC4, XMC7 MCUs with built-in Ethernet    |
-| **Texas Instruments**  |  TM4C, TMS570 MCUs with built-in Ethernet   |
-| **Cypress WiFi**  | Any MCU with CY43xx WiFi chips, like RP2040 Pico-W, RP2350 Pico2-W, Arduino Portenta    |
-| **Wiznet Ethernet**  | Any MCU that use Wiznet W5500 or Wiznet 5100 MAC+PHY chips    |
-| **Cellular**   | NRF9160, SIM800    |
-
 ## Usage Examples
 
 Below are quick snippets that should give an idea how simple the API is and
@@ -158,6 +171,17 @@ int main() {
 }
 ```
 
+## Licensing
+
+Mongoose is dual-licensed:
+- GPLv2: free for open source projects. Many popular open source projects use
+  Mongoose, for example
+  [SWUpdate](https://github.com/sbabic/swupdate/tree/master/mongoose), the
+  embedded Linux update framework
+- Commercial: for closed-source products. Includes support directly from the
+  engineers who wrote the whole stack, and early security fixes.
+  See [licensing](https://mongoose.ws/licensing/)
+
 ## Commercial use
 - Mongoose is used by hundreds of businesses, from Fortune500 giants like
   Siemens, Schneider Electric, Broadcom, Bosch, Google, Samsung, Qualcomm, Caterpillar to the small businesses
@@ -222,12 +246,12 @@ Technical guides and deep dives into embedded web servers, WebUI integration and
 - [lwIP vs Mongoose - TCP/IP Stack Integration Benchmark](https://mongoose.ws/articles/lwip-vs-mongoose-tcpip-stack-integration/)
 - [Embedded TCP/IP Stacks Comparison](https://mongoose.ws/embedded-tcpip-stack-comparison/)
 - [STM32H5 File System on Internal Flash: LittleFS + Mongoose](https://mongoose.ws/articles/stm32h5-file-system-on-internal-flash/)
-- [Firmware OTA and remote control on NXP FRDM-RW612](https://mongoose.ws/articles/mdash/)
+- [Firmware OTA and remote control on NXP FRDM-RW612](https://mongoose.ws/articles/rw612-mdash/)
 - [25000 WebSocket messages per second on STM32 Nucleo-H723ZG](https://mongoose.ws/articles/stm32-websocket-benchmark/)
 - [How to connect STM32 to AWS IoT Core](https://mongoose.ws/articles/stm32-aws-iot/)
 - [How to connect STM32 to Azure IoT Hub](https://mongoose.ws/articles/stm32-azure-iot-hub/)
 - [How to connect STM32 to EMQX](https://mongoose.ws/articles/stm32-emqx/)
-- [STM32 Device Management deep dive: Secure OTA, Remote Control, health monitor](https://mongoose.ws/articles/stm32-mdash-deep-dive/")
+- [STM32 Device Management deep dive: Secure OTA, Remote Control, health monitor](https://mongoose.ws/articles/stm32-mdash-deep-dive/)
 - [STM32 TCP/IP footprint: how much flash and RAM does Mongoose take?](https://mongoose.ws/articles/tcp-ip-footprint/)
 
 

mongoose.c

@@ -167,6 +167,7 @@ fail:
 #endif
 
 
+
 #include <stdarg.h>
 
 #if MG_ENABLE_BSD_SOCKETS && MG_ENABLE_FREERTOS
@@ -277,6 +278,57 @@ static struct mg_connection *bsd_new_conn(struct mg_bsd_sock *s) {
   return c;
 }
 
+// Mirror net_builtin.c::trim_len() logic
+static bool bsd_udp_too_big(struct mg_connection *c, size_t len) {
+  struct mg_tcpip_if *ifp = c->mgr->ifp;
+  size_t hlen = c->rem.is_ip6 ? 48 : 32;  // IP plus UDP headers
+  size_t cap = ifp->mtu - hlen;
+  size_t room = ifp->tx.len - (ifp->framesize - ifp->l2mtu) - hlen;
+
+  return len > cap || len > room;
+}
+
+static bool bsd_udp_send(struct mg_connection *c, uint32_t ip, uint16_t port,
+                         const void *buf, size_t len) {
+  struct mg_bsd_udp_frame *h;
+  size_t off = c->send.len, total = sizeof(*h) + len;
+
+  if (mg_iobuf_add(&c->send, off, NULL, total) != total) return false;
+  h = (struct mg_bsd_udp_frame *) (c->send.buf + off);
+  h->ip = ip;
+  h->port = port;
+  h->len = (uint16_t) len;
+  memcpy(h + 1, buf, len);
+  return true;
+}
+
+static size_t bsd_recv(struct mg_bsd_sock *s, void *buf, size_t len,
+                       int flags, struct sockaddr *src, socklen_t *addrlen) {
+  struct mg_connection *c = s->c;
+  size_t n;
+
+  if (!s->is_udp) {
+    n = c->recv.len < len ? c->recv.len : len;
+    memcpy(buf, c->recv.buf, n);
+    if (!(flags & MSG_PEEK)) mg_iobuf_del(&c->recv, 0, n);
+  } else {
+    struct mg_bsd_udp_frame *h = (struct mg_bsd_udp_frame *) c->recv.buf;
+    assert(c->recv.len >= sizeof(*h));
+    assert(h->len <= c->recv.len - sizeof(*h));
+    n = h->len < len ? h->len : len;
+    memcpy(buf, h + 1, n);
+    if (src != NULL && addrlen != NULL) {
+      struct sockaddr_in *sa = (struct sockaddr_in *) src;
+      sa->sin_family = AF_INET;
+      sa->sin_port = h->port;
+      sa->sin_addr.s_addr = h->ip;
+      *addrlen = sizeof(*sa);
+    }
+    if (!(flags & MSG_PEEK)) mg_iobuf_del(&c->recv, 0, sizeof(*h) + h->len);
+  }
+  return n;
+}
+
 #if MG_ENABLE_FREERTOS
 // Complete operations blocked on c before Mongoose destroys it.
 static void bsd_finish_waiters(struct mg_bsd_sock *s, bool error) {
@@ -457,9 +509,9 @@ static int bsd_ready(struct mg_bsd_sock *s) {
     return 0;
   }
   if (s->c->recv.len > 0 || s->c->is_draining) ready |= BSD_READ;
-  if (!s->is_udp && !s->c->is_connecting && !s->c->is_closing &&
+  if ((s->is_udp || !s->c->is_connecting) && !s->c->is_closing &&
       !s->c->is_draining)
-    ready |= BSD_WRITE;  // Established TCP socket
+    ready |= BSD_WRITE;  // UDP socket or established TCP socket
   return ready;
 }
 
@@ -473,7 +525,7 @@ static void bsd_close(struct mg_bsd_sock *s) {
     if (t->orphan && t->listener == s) {
       if (t->c != NULL) {
         t->c->fn_data = NULL;
-        mg_close_conn(t->c);
+        t->c->is_draining = 1;
         t->c = NULL;
       }
       memset(t, 0, sizeof(*t));  // Release orphan
@@ -481,7 +533,7 @@ static void bsd_close(struct mg_bsd_sock *s) {
   }
   if (s->c != NULL) {
     s->c->fn_data = NULL;
-    mg_close_conn(s->c);
+    s->c->is_draining = 1;
     s->c = NULL;
   }
   memset(s, 0, sizeof(*s));  // Release socket
@@ -660,8 +712,8 @@ static bool bsd_run(struct mg_bsd_cmd *cmd) {
         cmd->result = -1, cmd->err = ECONNREFUSED;
         return true;
       }
-      if (!c->is_connecting) {
-        cmd->result = 0;
+      if (s->is_udp || !c->is_connecting) {
+        cmd->result = 0;  // UDP may still resolve ARP; TCP waits for SYN/SYN-ACK
         return true;
       }
       if (s->nonblock) {
@@ -685,11 +737,8 @@ static bool bsd_run(struct mg_bsd_cmd *cmd) {
         return true;
       }
       if (c->recv.len > 0) {
-        size_t n = cmd->op_recv.len;
-        if (c->recv.len < n) n = c->recv.len;
-        memcpy(cmd->op_recv.buf, c->recv.buf, n);
-        if (!(cmd->op_recv.flags & MSG_PEEK)) mg_iobuf_del(&c->recv, 0, n);
-        cmd->result = (int) n;
+        cmd->result = (int) bsd_recv(s, cmd->op_recv.buf, cmd->op_recv.len,
+                                     cmd->op_recv.flags, NULL, NULL);
         return true;
       }
       if (s->err != 0) {
@@ -710,10 +759,17 @@ static bool bsd_run(struct mg_bsd_cmd *cmd) {
     case BSD_OP_SEND:
       if ((s = bsd_get(cmd->op_send.fd)) == NULL) {
         cmd->result = -1, cmd->err = EBADF;
-      } else if ((c = s->c) == NULL || s->err != 0 || c->is_closing ||
-                 c->is_draining) {
+      } else if (s->err != 0 || s->closed ||
+                 ((c = s->c) != NULL && (c->is_closing || c->is_draining))) {
         cmd->result = -1, cmd->err = EPIPE;
-      } else if (mg_send(c, cmd->op_send.buf, cmd->op_send.len)) {
+      } else if (c == NULL || (s->is_udp && !c->is_client)) {
+        cmd->result = -1, cmd->err = s->is_udp ? EDESTADDRREQ : EPIPE;
+      } else if (s->is_udp && bsd_udp_too_big(c, cmd->op_send.len)) {
+        cmd->result = -1, cmd->err = EMSGSIZE;
+      } else if ((s->is_udp ? bsd_udp_send(c, c->rem.addr.ip4, c->rem.port,
+                                            cmd->op_send.buf, cmd->op_send.len)
+                            : mg_send(c, cmd->op_send.buf,
+                                      cmd->op_send.len))) {
         cmd->result = (int) cmd->op_send.len;
       } else if (s->nonblock || (cmd->op_send.flags & MSG_DONTWAIT)) {
         cmd->result = -1, cmd->err = EAGAIN;
@@ -728,16 +784,20 @@ static bool bsd_run(struct mg_bsd_cmd *cmd) {
     case BSD_OP_SENDTO:
       if ((s = bsd_get(cmd->op_sendto.fd)) == NULL) {
         cmd->result = -1, cmd->err = EBADF;
+      } else if (!s->is_udp) {
+        cmd->result = -1, cmd->err = EOPNOTSUPP;
       } else if ((c = s->c) == NULL || s->err != 0 || c->is_closing ||
                  c->is_draining) {
         cmd->result = -1, cmd->err = EPIPE;
+      } else if (c->is_client) {
+        cmd->result = -1, cmd->err = EISCONN;
       } else {
         const struct sockaddr_in *sa =
             (const struct sockaddr_in *) cmd->op_sendto.addr;
-        c->rem.port = sa->sin_port;
-        c->rem.addr.ip4 = sa->sin_addr.s_addr;
-        c->rem.is_ip6 = false;
-        if (mg_send(c, cmd->op_sendto.buf, cmd->op_sendto.len)) {
+        if (bsd_udp_too_big(c, cmd->op_sendto.len)) {
+          cmd->result = -1, cmd->err = EMSGSIZE;
+        } else if (bsd_udp_send(c, sa->sin_addr.s_addr, sa->sin_port,
+                                cmd->op_sendto.buf, cmd->op_sendto.len)) {
           cmd->result = (int) cmd->op_sendto.len;
         } else if (s->nonblock || (cmd->op_sendto.flags & MSG_DONTWAIT)) {
           cmd->result = -1, cmd->err = EAGAIN;
@@ -754,6 +814,9 @@ static bool bsd_run(struct mg_bsd_cmd *cmd) {
       if ((s = bsd_get(cmd->op_recvfrom.fd)) == NULL) {
         cmd->result = -1, cmd->err = EBADF;
         return true;
+      } else if (!s->is_udp) {
+        cmd->result = -1, cmd->err = EOPNOTSUPP;
+        return true;
       }
       if ((c = s->c) == NULL) {
         cmd->result = s->closed && s->err == 0 ? 0 : -1;
@@ -761,18 +824,11 @@ static bool bsd_run(struct mg_bsd_cmd *cmd) {
         return true;
       }
       if (c->recv.len > 0) {
-        size_t n = cmd->op_recvfrom.len;
-        if (c->recv.len < n) n = c->recv.len;
-        memcpy(cmd->op_recvfrom.buf, c->recv.buf, n);
-        if (!(cmd->op_recvfrom.flags & MSG_PEEK)) mg_iobuf_del(&c->recv, 0, n);
-        if (cmd->op_recvfrom.src != NULL && cmd->op_recvfrom.addrlen != NULL) {
-          struct sockaddr_in *sa = (struct sockaddr_in *) cmd->op_recvfrom.src;
-          sa->sin_family = AF_INET;
-          sa->sin_port = c->rem.port;
-          sa->sin_addr.s_addr = c->rem.addr.ip4;
-          *cmd->op_recvfrom.addrlen = sizeof(*sa);
-        }
-        cmd->result = (int) n;
+        cmd->result = (int) bsd_recv(s, cmd->op_recvfrom.buf,
+                                     cmd->op_recvfrom.len,
+                                     cmd->op_recvfrom.flags,
+                                     cmd->op_recvfrom.src,
+                                     cmd->op_recvfrom.addrlen);
         return true;
       }
       if (s->err != 0) {
@@ -1668,21 +1724,6 @@ static void mg_dash_handle_add(struct mg_connection *c, struct mg_dash *dash,
   }
 }
 
-// Firmware upload callback for mg_http_stream_body(). Uses *p as a flag:
-// non-NULL means an OTA session is open and must be closed by mg_ota_end()
-static bool otacb(struct mg_http_message *hm, struct mg_str *data, void **p) {
-  if (hm != NULL) {  // Start
-    if (!mg_ota_begin(hm->body.len)) return false;
-    *p = (void *) (ptrdiff_t) 1;
-    return true;
-  } else if (data != NULL) {  // Next chunk
-    return mg_ota_write(data->buf, data->len);
-  }
-  if (*p == NULL) return false;  // End. Begin failed, nothing to finish
-  *p = NULL;
-  return mg_ota_end();
-}
-
 static void mg_serve_fs(struct mg_connection *c, struct mg_http_message *hm,
                         struct mg_dash_user *u, bool stream) {
   struct mg_dash *dash = (struct mg_dash *) c->fn_data;
@@ -1729,9 +1770,9 @@ void mg_dash_ev_handler(struct mg_connection *c, int ev, void *ev_data) {
       mg_serve_fs(c, hm, u, true);
       return;  // Important - the serve_fs() call can invalidate hm
     } else if (mg_match(hm->uri, mg_str("/api/ota"), NULL)) {
-      // Authenticated above. If streaming started, the stream handler owns
-      // the connection and c->data, so skip the marker check below
-      if (mg_http_stream_body(c, hm, otacb, NULL)) return;
+      // Authenticated above. Streaming owns the connection and c->data.
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+      return;
     }
     if (d->marker != '\0') mg_log_http_req(c, hm);
   } else if (ev == MG_EV_HTTP_MSG && d->marker != '\0') {
@@ -3641,66 +3682,12 @@ struct mg_fs mg_fs_posix = {p_stat,  p_list, p_open,   p_close,  p_read,
 
 
 
-#if MG_ENABLE_HEALTH
-#if MG_ARCH == MG_ARCH_ESP32
-// reusable for other platforms, currently ESP32-only
-struct mg_health_coredump {
-  const void *ptr;
-  size_t poffset;
-  size_t size;
-};
-
-static struct mg_health_coredump s_coredump;
-#endif
-
-bool mg_health_coredump_begin(size_t *size) {
-#if MG_ARCH == MG_ARCH_ESP32 && CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH
-  const esp_partition_t *p = esp_partition_find_first(
-      ESP_PARTITION_TYPE_DATA, ESP_PARTITION_SUBTYPE_DATA_COREDUMP, NULL);
-  size_t address = 0, len = 0;
-  esp_err_t err = esp_core_dump_image_get(&address, &len);
-  if (size == NULL || s_coredump.ptr != NULL || err != ESP_OK || p == NULL)
-    return false;
-  s_coredump.ptr = p;
-  s_coredump.poffset = address - p->address;
-  s_coredump.size = len;
-  *size = len;
-  return true;
-#else
-  (void) size;
-  return false;
-#endif
-}
-
-bool mg_health_coredump_read(size_t offset, void *buf, size_t *len) {
-#if MG_ARCH == MG_ARCH_ESP32 && CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH
-  const esp_partition_t *p = (const esp_partition_t *) s_coredump.ptr;
-  if (p == NULL || offset > s_coredump.size)
-    return false;
-  if (*len > s_coredump.size - offset) *len = s_coredump.size - offset;
-  return esp_partition_read(p, s_coredump.poffset + offset, buf, *len) == ESP_OK;
-#else
-  (void) offset, (void) buf, (void) len;
-  return false;
-#endif
-}
-
-bool mg_health_coredump_end(void) {
-#if MG_ARCH == MG_ARCH_ESP32 && CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH
-  bool ok = s_coredump.ptr != NULL;
-  memset(&s_coredump, 0, sizeof(s_coredump));
-  return ok;
-#else
-  return false;
-#endif
-}
-
 // The one health record. Lives in RAM that survives a warm reset, see
 // MG_HEALTH_RAM and the .mg_health region in the linker script
 struct mg_health mg_health_record MG_HEALTH_RAM;
 
-// STM32 H7, H5, C5 support. Needs the _estack symbol from the linker script
-#if defined(STM32H7_DEV_ID) || defined(STM32H5) || defined(STM32C5)
+// STM32 H723 support. Needs the _estack symbol from the linker script
+#if MG_ENABLE_HEALTH && (defined(STM32H7_DEV_ID) || defined(STM32H5) || defined(STM32C5))
 // Fault handler body. Runs in exception context: no printf, no malloc, no
 // blocking calls. Copies the unwind registers and raw stack into the health
 // record, then resets.
@@ -3742,57 +3729,52 @@ void BusFault_Handler(void) __attribute__((alias("HardFault_Handler")));
 void UsageFault_Handler(void) __attribute__((alias("HardFault_Handler")));
 #endif
 
-// Start a new boot: validate the record. Called by MG_HEALTH_INIT()
+// Start a new boot: validate the record, count the boot, store the reset
+// reason. The current boot moves to prev_* slots first, so the previous
+// boot's uptime and reason stay readable. Called by MG_HEALTH_INIT()
 void mg_health_init(void) {
   char magic[] = MG_HEALTH_MAGIC;
+  // struct mg_health *h = mg_health_get();
   if (!mg_health_valid()) {  // First boot, or RAM lost its contents
     memset(&mg_health_record, 0, sizeof(mg_health_record));
     memcpy(mg_health_record.magic, magic, sizeof(mg_health_record.magic));
   }
-#if MG_ARCH == MG_ARCH_ESP32
-#if CONFIG_IDF_TARGET_ARCH_XTENSA
-  mg_health_record.arch = (uint16_t) MG_HEALTH_ARCH_XTENSA;
-#elif CONFIG_IDF_TARGET_ARCH_RISCV
-  mg_health_record.arch = (uint16_t) MG_HEALTH_ARCH_RISCV;
-#endif
-  esp_reset_reason_t rr = esp_reset_reason();
-  mg_health_record.reset_reason = esp2mg(rr);
-#if CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH == 0
-  MG_ERROR(("MG_HEALTH is enabled but CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH=n"));
-#else
+
+#if 0 && MG_ARCH == MG_ARCH_ESP32 && CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH
+  {
     // After a crash, copy the backtrace from the core dump in flash: the same
     // addresses the panic handler prints as "Backtrace: PC:SP PC:SP ...".
     // The core dump stays in flash, so check the reset reason, otherwise an
     // old crash is reported on every boot
-    esp_core_dump_summary_t *s = calloc(1, sizeof(*s));
+    static esp_core_dump_summary_t s;  // Big on RISC-V, keep it off the stack
+    esp_reset_reason_t rr = esp_reset_reason();
     uint32_t *out = mg_health_record.data;
-    size_t n = 0;
+    size_t n = 0, max = MG_HEALTH_DATA_SIZE;
+    if (rr != ESP_RST_PANIC && rr != ESP_RST_INT_WDT && rr != ESP_RST_TASK_WDT)
+      return;  // Not a crash that went through the panic handler
+    if (max == 0 || esp_core_dump_get_summary(&s) != ESP_OK) return;
+
+    mg_health_record.cpuid = 42;  // ESP32
+    mg_health_record.reset_reason = MG_HEALTH_RESET_FAULT;
+
     memset(out, 0, sizeof(mg_health_record.data));
-    if (s == NULL) return;
-    if ((rr != ESP_RST_PANIC && rr != ESP_RST_INT_WDT &&
-         rr != ESP_RST_TASK_WDT)  // Not a crash caught by the panic handler
-        || esp_core_dump_get_summary(s) != ESP_OK) {
-      free(s);
-      return;
-    }
-    out[n++] = s->exc_pc;
-    memcpy(&out[n], s->exc_task, 16), n += 4;
+    out[n++] = s.exc_pc;
 #if CONFIG_IDF_TARGET_ARCH_XTENSA
-    out[n++] = s->ex_info.exc_a[0];
-    out[n++] = s->ex_info.exc_a[1];
-    size_t len = s->exc_bt_info.depth;
-    if (len > MG_HEALTH_DATA_SIZE - n) len = (MG_HEALTH_DATA_SIZE - n);
-    memcpy(&out[n], s->exc_bt_info.bt, 4 * len); // sizeof(uint32_t)
+    for (uint32_t i = 0; i < s.exc_bt_info.depth && n < max; i++) {
+      if (s.exc_bt_info.bt[i] != s.exc_pc) out[n++] = s.exc_bt_info.bt[i];
+    }
 #elif CONFIG_IDF_TARGET_ARCH_RISCV
-    out[n++] = s->ex_info.exc_ra;
-    out[n++] = s->ex_info.exc_sp;
-    size_t len = s->exc_bt_info.dump_size / 4 ; // sizeof(uint32_t)
-    if (len > MG_HEALTH_DATA_SIZE - n) len = (MG_HEALTH_DATA_SIZE - n);
-    memcpy(&out[n], s->exc_bt_info.stackdump, 4 * len);
+    // No unwinder: take the return address, then words on the stack that
+    // point into executable memory (a heuristic, may include stale values)
+    if (n < max) out[n++] = s.ex_info.ra;
+    for (uint32_t i = 0; i + 4 <= s.exc_bt_info.dump_size && n < max; i += 4) {
+      uint32_t w;
+      memcpy(&w, &s.exc_bt_info.stackdump[i], sizeof(w));  // Byte array
+      if (esp_ptr_executable((void *) (uintptr_t) w)) out[n++] = w;
+    }
+#endif
+  }
 #endif
-    free(s);
-#endif  // CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH
-#endif  // MG_ARCH_ESP32
 }
 
 static size_t print_uint32(void (*fn)(char, void *), void *arg, va_list *ap) {
@@ -3806,17 +3788,11 @@ static size_t print_uint32(void (*fn)(char, void *), void *arg, va_list *ap) {
 size_t mg_print_crash_record(void (*fn)(char, void *), void *arg, va_list *ap) {
   size_t len = 0;
   if (mg_health_valid() &&
-      (mg_health_record.reset_reason == (uint16_t) MG_HEALTH_RESET_FAULT
-#if MG_ARCH == MG_ARCH_ESP32
-       || mg_health_record.reset_reason == (uint16_t) MG_HEALTH_RESET_WATCHDOG
-#endif
-       )) {
+      mg_health_record.reset_reason == MG_HEALTH_RESET_FAULT) {
     size_t n = sizeof(mg_health_record.data) / sizeof(mg_health_record.data[0]);
-    len += mg_xprintf(fn, arg, "{%m:%hhu,%m:%hu,%m:%hu,%m:%u,%m:[%M]}",  //
-                      MG_ESC("version"), mg_health_record.magic[3],      //
-                      MG_ESC("arch"), mg_health_record.arch,             //
-                      MG_ESC("reason"), mg_health_record.reset_reason,   //
-                      MG_ESC("cpuid"), mg_health_record.cpuid,           //
+    len += mg_xprintf(fn, arg, "{%m:%hhu,%m:%u,%m:[%M]}",            //
+                      MG_ESC("version"), mg_health_record.magic[3],  //
+                      MG_ESC("cpuid"), mg_health_record.cpuid,       //
                       MG_ESC("data"), print_uint32, n, mg_health_record.data);
   } else {
     len += mg_xprintf(fn, arg, "{}");
@@ -3824,7 +3800,6 @@ size_t mg_print_crash_record(void (*fn)(char, void *), void *arg, va_list *ap) {
   (void) ap;
   return len;
 }
-#endif
 
 #ifdef MG_ENABLE_LINES
 #line 1 "src/http.c"
@@ -4710,8 +4685,8 @@ void mg_http_serve_upload(struct mg_connection *c, struct mg_http_message *hm,
     fs->rm(path);  // MG_FS_WRITE appends, not truncates: drop any old file
     if ((fd = mg_fs_open(fs, path, MG_FS_WRITE)) == NULL) {
       MG_ERROR(("Cannot open %s for upload", path));
-    } else if (!mg_http_stream_body(c, hm, serve_upload_cb, fd)) {
-      mg_fs_close(fd);
+    } else {
+      mg_http_stream_body(c, hm, serve_upload_cb, fd);
     }
   }
 }
@@ -4845,6 +4820,7 @@ struct mg_upload_state {
   size_t received;  // Number of body bytes received so far
   void *user_data;  // Passed to cb, free for cb to use
   bool failed;      // Set when cb returned false
+  bool finished;    // End callback has been called
 };
 
 // Event handler installed by mg_http_stream_body(). Feeds the body to the
@@ -4852,18 +4828,18 @@ struct mg_upload_state {
 // handler: the connection is closed after the reply.
 static void mg_stream_handler(struct mg_connection *c, int ev, void *ev_data) {
   struct mg_upload_state *us = (struct mg_upload_state *) c->data;
-    bool (*fn)(struct mg_http_message *, struct mg_str *, void **) =
+  bool (*fn)(struct mg_http_message *, struct mg_str *, void **) =
       (bool (*)(struct mg_http_message *, struct mg_str *, void **))
       (ptrdiff_t) c->fn_data;
   (void) ev_data;
   if (ev == MG_EV_CLOSE || ev == MG_EV_ERROR) {
-    if (us->received < us->expected) {
+    if (!us->finished) {
       // Connection dropped mid-upload. Let cb clean up, e.g. call mg_ota_end()
-      us->received = us->expected;  // MG_EV_ERROR is followed by MG_EV_CLOSE
+      us->finished = true;  // MG_EV_ERROR is followed by MG_EV_CLOSE
       fn(NULL, NULL, &us->user_data);
     }
-  } else if (ev == MG_EV_READ && !c->is_draining) {
-    if (c->recv.len > 0 && us->received < us->expected) {
+  } else if (ev == MG_EV_READ && !c->is_draining && !us->finished) {
+    if (!us->failed && c->recv.len > 0 && us->received < us->expected) {
       // Got some uploaded data. Feed by 512-byte aligned chunks, for OTA
       size_t left = us->expected - us->received, r = c->recv.len;
       size_t aligned = r < left ? MG_ROUND_DOWN(r, 512) : left;
@@ -4874,10 +4850,13 @@ static void mg_stream_handler(struct mg_connection *c, int ev, void *ev_data) {
       us->received += aligned;
       mg_iobuf_del(&c->recv, 0, aligned);  // Shift the unprocessed tail
     }
-    if (us->received >= us->expected) {
+    if (!us->finished && (us->failed || us->received >= us->expected)) {
       // Finished upload. Always call cb, even after error, so it can clean up
+      us->finished = true;
       us->failed |= !fn(NULL, NULL, &us->user_data);
-      if (!c->is_client) {
+      if (c->is_client && us->failed) {
+        mg_error(c, "Body streaming failed");
+      } else if (!c->is_client) {
         mg_http_reply(c, us->failed ? 500 : 200, NULL, "%zu %s\n",
                       us->received, us->failed ? "fail" : "ok");
       }
@@ -4886,48 +4865,54 @@ static void mg_stream_handler(struct mg_connection *c, int ev, void *ev_data) {
   }
 }
 
-bool mg_http_stream_body(struct mg_connection *c, struct mg_http_message *hm,
+void mg_http_stream_body(struct mg_connection *c, struct mg_http_message *hm,
                          bool (*cb)(struct mg_http_message *, struct mg_str *,
-                                    void **user_data),
+                                    void **),
                          void *user_data) {
   struct mg_upload_state *us = (struct mg_upload_state *) c->data;
-  struct mg_str *te = mg_http_get_header(hm, "Transfer-Encoding");
-  bool handled = false;
+  int code = 0;
+  size_t head_len = hm->head.len;
 
   // Catch upload requests early, without buffering whole body. Called on the
   // MG_EV_HTTP_HDRS event: we've received all HTTP headers but not necessarily
   // the full HTTP body
-  if (hm->body.len == (size_t) ~0 ||
-      (te != NULL && mg_strcasecmp(*te, mg_str("chunked")) == 0)) {
-    // Unknown length or chunked, cannot stream. Leave it to the caller
-  } else if (!c->is_client &&
-             mg_strcmp(hm->method, mg_str("POST")) != 0 &&
-             mg_strcmp(hm->method, mg_str("PUT")) != 0) {
-    // Not an upload request. Leave it to the caller
+  if (!c->is_client && mg_strcmp(hm->method, mg_str("POST")) != 0 &&
+      mg_strcmp(hm->method, mg_str("PUT")) != 0) {
+    code = 405;
+  } else if (mg_http_get_header(hm, "Transfer-Encoding") != NULL) {
+    code = 400;
+  } else if (hm->body.len == (size_t) ~0 ||
+             (!c->is_client && mg_http_get_header(hm, "Content-Length") == NULL)) {
+    code = 411;
   } else if (sizeof(*us) > sizeof(c->data)) {
-    if (!c->is_client) {  // Nobody to reply to on a client connection
-      c->pfn = NULL;
-      mg_http_reply(c, 500, NULL, "data too small\n");
-      c->is_draining = 1;
-      cb(NULL, NULL, &user_data);  // Let cb release user_data, start skipped
-      handled = true;
+    code = 500;
+  }
+  c->pfn = NULL;  // Take ownership even when validation fails
+  if (code != 0) {
+    c->fn = NULL;
+    c->fn_data = NULL;
+    mg_iobuf_del(&c->recv, 0, c->recv.len);
+    cb(NULL, NULL, &user_data);  // Release resources even if start was skipped
+    if (c->is_client) {
+      mg_error(c, "%s", mg_http_status_code_str(code));
+    } else {
+      mg_http_reply(c, code, code == 405 ? "Allow: POST, PUT\r\n" : NULL, "");
     }
+    c->is_draining = 1;
   } else {
-    c->pfn = NULL;  // Silence HTTP protocol handler
     memset(us, 0, sizeof(*us));
     us->expected = hm->body.len;  // Store number of bytes we expect
     us->user_data = user_data;
+    c->fn = mg_stream_handler;
+    c->fn_data = (void *) (ptrdiff_t) cb;
     us->failed = !cb(hm, NULL, &us->user_data);  // Call before deleting headers
-    if (mg_http_get_header(hm, "Expect") != NULL) {
+    if (!c->is_client && !us->failed && !us->finished &&
+        mg_http_get_header(hm, "Expect") != NULL) {
       mg_http_reply(c, 100, NULL, "");  // If curl expects, we continue
     }
-    mg_iobuf_del(&c->recv, 0, hm->head.len);  // Delete HTTP headers
-    c->fn = mg_stream_handler;                // We own the connection from now
-    c->fn_data = (void *) (ptrdiff_t) cb;
+    mg_iobuf_del(&c->recv, 0, head_len);  // Delete HTTP headers
     mg_call(c, MG_EV_READ, &c->recv.len);  // Process the body bytes we have
-    handled = true;
   }
-  return handled;
 }
 
 static bool is_hex_digit(int c) {
@@ -5852,7 +5837,7 @@ size_t mg_l2_driver_output(struct mg_tcpip_if *ifp, size_t len) {
 #define MGI_802154_DATA (125 - MGI_802154_HDR)
 
 size_t mg_l2_802154_tx(struct mg_tcpip_if *ifp, const void *buf, size_t len,
-                       size_t (*send)(const uint8_t *, size_t,
+                       size_t (*send_fn)(const uint8_t *, size_t,
                                       struct mg_tcpip_if *)) {
   struct mg_l2_802154_data *d =
       (struct mg_l2_802154_data *) ifp->driver_data;
@@ -5870,7 +5855,7 @@ size_t mg_l2_802154_tx(struct mg_tcpip_if *ifp, const void *buf, size_t len,
     f[12] = m[2], f[13] = m[1], f[14] = m[0];  // Little endian EUI-64
     f[15] = d->tag, f[16] = (uint8_t) ((i << 4) | last);
     memcpy(f + MGI_802154_HDR, p + i * MGI_802154_DATA, n);
-    if (send(f, MGI_802154_HDR + n, ifp) == 0) return 0;
+    if (send_fn(f, MGI_802154_HDR + n, ifp) == 0) return 0;
   }
   return len;
 }
@@ -7404,7 +7389,6 @@ static void mg_mdash_fn(struct mg_connection *c, int ev, void *ev_data) {
     }
     mg_iobuf_free(&io);
   } else if (ev == MG_EV_CLOSE) {
-    mg_health_coredump_end();
     mg_mdash_conn = NULL;
     MG_INFO(("disconnected, ram %lu", 0));
   }
@@ -7462,35 +7446,6 @@ static void mg_mdash_rpc_ota_end(struct mg_rpc_req *r) {
   // MG_ESC("percent"));
 }
 
-static void rpc_coredump_begin(struct mg_rpc_req *r) {
-  size_t size = 0;
-  if (mg_health_coredump_begin(&size)) {
-    mg_rpc_ok(r, "{%m:%llu}", MG_ESC("size"), (uint64_t) size);
-  } else {
-    mg_rpc_err(r, 500, "%m", MG_ESC("failed"));
-  }
-}
-
-static void rpc_coredump_read(struct mg_rpc_req *r) {
-  uint8_t buf[768];
-  size_t len = sizeof(buf);
-  size_t offset = (size_t) mg_json_get_long(r->frame, "$.params.offset", -1);
-  if (mg_health_coredump_read(offset, buf, &len)) {
-    mg_rpc_ok(r, "{%m:\"%M\"}", MG_ESC("data"), mg_print_base64,
-              (int) len, buf);
-  } else {
-    mg_rpc_err(r, 500, "%m", MG_ESC("failed"));
-  }
-}
-
-static void rpc_coredump_end(struct mg_rpc_req *r) {
-  if (mg_health_coredump_end()) {
-    mg_rpc_ok(r, "true");
-  } else {
-    mg_rpc_err(r, 500, "%m", MG_ESC("failed"));
-  }
-}
-
 void mg_mdash_init(struct mg_mgr *mgr) {
   MG_INFO(("Initialising mdash agent, key [%s]", MG_MDASH_KEY));
   mg_rpc_add(&mgr->rpcs, mg_str("RPC.List"), mg_rpc_list, NULL);
@@ -7498,9 +7453,6 @@ void mg_mdash_init(struct mg_mgr *mgr) {
   mg_rpc_add(&mgr->rpcs, mg_str("OTA.Begin"), mg_mdash_rpc_ota_begin, NULL);
   mg_rpc_add(&mgr->rpcs, mg_str("OTA.Write"), mg_mdash_rpc_ota_write, NULL);
   mg_rpc_add(&mgr->rpcs, mg_str("OTA.End"), mg_mdash_rpc_ota_end, NULL);
-  mg_rpc_add(&mgr->rpcs, mg_str("CoreDump.Begin"), rpc_coredump_begin, NULL);
-  mg_rpc_add(&mgr->rpcs, mg_str("CoreDump.Read"), rpc_coredump_read, NULL);
-  mg_rpc_add(&mgr->rpcs, mg_str("CoreDump.End"), rpc_coredump_end, NULL);
 }
 
 void mg_mdash_poll(struct mg_mgr *mgr) {
@@ -9378,6 +9330,36 @@ static void l2addr_resolved(struct mg_connection *c);
 static uint8_t *get_return_l2addr(struct mg_tcpip_if *ifp, struct mg_addr *rem,
                                   bool is_udp, struct pkt *pkt);
 
+#if MG_ENABLE_BSD_SOCKETS
+static uint8_t *sendto_cache_find(struct mg_tcpip_if *ifp, uint32_t ip) {
+  struct mg_tcpip_sendto_entry *a;
+  for (a = ifp->sendto; a < ifp->sendto + MG_TCPIP_SENDTO_CACHE_SIZE; a++) {
+    if (a->ip == ip) return (uint8_t *) &a->addr;
+  }
+  return NULL;
+}
+
+static void sendto_cache_add(struct mg_tcpip_if *ifp, uint32_t ip,
+                             const uint8_t *addr) {
+  struct mg_tcpip_sendto_entry *a;
+  for (a = ifp->sendto; a < ifp->sendto + MG_TCPIP_SENDTO_CACHE_SIZE; a++) {
+    if (a->ip == ip) return;  // already cached, skip
+    if (a->ip == 0) break;    // not present, first empty slot
+  }
+  if (a == ifp->sendto + MG_TCPIP_SENDTO_CACHE_SIZE) { // no room
+    memmove(ifp->sendto, ifp->sendto + 1,
+            sizeof(ifp->sendto[0]) * (MG_TCPIP_SENDTO_CACHE_SIZE - 1));
+    a--; // make room and point to last entry (just made)
+  }
+  a->ip = ip; // populate this entry
+  memcpy(&a->addr, addr, sizeof(a->addr));
+}
+
+static void sendto_cache_clear(struct mg_tcpip_if *ifp) {
+  memset(ifp->sendto, 0, sizeof(ifp->sendto));
+}
+#endif
+
 // RFC826, ARP assumes Ethernet MAC addresses
 static void rx_arp(struct mg_tcpip_if *ifp, struct pkt *pkt) {
   if (pkt->arp->op == mg_htons(1) && pkt->arp->tpa == ifp->ip) {
@@ -9983,30 +9965,57 @@ static void proto_error(struct mg_connection *c, bool r, const char *f, ...) {
 static bool rx_udp(struct mg_tcpip_if *ifp, struct pkt *pkt) {
   struct mg_connection *c = getpeer(ifp->mgr, pkt, true);
   struct connstate *s;
+  struct mg_addr rem;
   uint8_t *l2addr;
+  size_t len = pkt->pay.len;
   if (c == NULL) return false;  // No UDP listener on this port
   s = (struct connstate *) (c + 1);
-  c->rem.port = pkt->udp->sport;
 #if MG_ENABLE_IPV6
   if (c->loc.is_ip6) {  // matching of v4/v6 to dest is done bt getpeer()
     if (!udp6csum_ok(pkt->ip6, pkt->udp)) return false;
-    c->rem.addr.ip6[0] = pkt->ip6->src[0],
-    c->rem.addr.ip6[1] = pkt->ip6->src[1], c->rem.is_ip6 = true;
+    if (c->is_bsd && c->is_client &&
+        (c->rem.port != pkt->udp->sport ||
+         !MG_IP6MATCH(c->rem.addr.ip6, pkt->ip6->src)))
+      return true;
+    rem.addr.ip6[0] = pkt->ip6->src[0],
+    rem.addr.ip6[1] = pkt->ip6->src[1], rem.is_ip6 = true;
   } else
 #endif
   {
     if (!udpcsum_ok(pkt->ip, pkt->udp)) return false;
-    c->rem.addr.ip4 = pkt->ip->src;
+    if (c->is_bsd && c->is_client &&
+        (c->rem.port != pkt->udp->sport || c->rem.addr.ip4 != pkt->ip->src))
+      return true;
+    rem.addr.ip4 = pkt->ip->src, rem.is_ip6 = false;
   }
-  if ((l2addr = get_return_l2addr(ifp, &c->rem, true, pkt)) == NULL)
+  rem.port = pkt->udp->sport;
+  if (!c->is_bsd || c->is_client) c->rem = rem;
+  if ((l2addr = get_return_l2addr(ifp, &rem, true, pkt)) == NULL)
     return false;  // safety net for lousy networks
-  memcpy(s->mac, l2addr, sizeof(s->mac));
+  if (!c->is_bsd || c->is_client) memcpy(s->mac, l2addr, sizeof(s->mac));
+#if MG_ENABLE_BSD_SOCKETS
+  if (c->is_bsd && !rem.is_ip6 && MG_IPISLOCAL(ifp, rem.addr.ip4))
+    sendto_cache_add(ifp, rem.addr.ip4, l2addr);
+#endif
+#if MG_ENABLE_BSD_SOCKETS
+  if (c->is_bsd) len += sizeof(struct mg_bsd_udp_frame);
+#endif
   if (c->recv.len >= MG_MAX_RECV_SIZE) {
     proto_error(c, false, "max_recv_buf_size reached");
-  } else if (c->recv.size - c->recv.len < pkt->pay.len &&
-             !mg_iobuf_resize(&c->recv, c->recv.len + pkt->pay.len)) {
+  } else if (c->recv.size - c->recv.len < len &&
+             !mg_iobuf_resize(&c->recv, c->recv.len + len)) {
     proto_error(c, false, "oom");
   } else {
+#if MG_ENABLE_BSD_SOCKETS
+    if (c->is_bsd) {
+      struct mg_bsd_udp_frame *h =
+          (struct mg_bsd_udp_frame *) &c->recv.buf[c->recv.len];
+      h->ip = rem.addr.ip4;
+      h->port = rem.port;
+      h->len = (uint16_t) pkt->pay.len;
+      c->recv.len += sizeof(*h);
+    }
+#endif
     memcpy(&c->recv.buf[c->recv.len], pkt->pay.buf, pkt->pay.len);
     c->recv.len += pkt->pay.len;
     mg_call(c, MG_EV_READ, &pkt->pay.len);
@@ -11059,6 +11068,9 @@ void mg_tcpip_init(struct mg_mgr *mgr, struct mg_tcpip_if *ifp) {
 
 static void close_conn(struct mg_connection *c) {
   struct connstate *s = (struct connstate *) (c + 1);
+#if MG_ENABLE_BSD_SOCKETS
+  if (c->is_bsd && c->is_udp) sendto_cache_clear(c->mgr->ifp);
+#endif
   mg_iobuf_free(&s->txq);
   mg_close_conn(c);
 }
@@ -11080,6 +11092,11 @@ static void send_syn(struct mg_connection *c) {
 static void l2addr_resolved(struct mg_connection *c) {
   if (c->is_udp) {
     c->is_connecting = 0;
+#if MG_ENABLE_BSD_SOCKETS
+    if (c->is_bsd)
+      sendto_cache_add(c->mgr->ifp, c->rem.addr.ip4,
+                       ((struct connstate *) (c + 1))->mac);
+#endif
     mg_call(c, MG_EV_CONNECT, NULL);
   } else {
     send_syn(c);
@@ -11094,20 +11111,25 @@ void mg_connect_resolved(struct mg_connection *c) {
   s->retransmit = ifp->enable_tcp_retransmit;
   s->txq.align = MG_TCPIP_TXQ_ALIGN;
   c->is_resolving = 0;
-  if (ifp->eport < MG_EPHEMERAL_PORT_BASE) ifp->eport = MG_EPHEMERAL_PORT_BASE;
-  c->loc.port = mg_htons(ifp->eport++);
+  if (c->loc.port == 0) {
+    if (ifp->eport < MG_EPHEMERAL_PORT_BASE)
+      ifp->eport = MG_EPHEMERAL_PORT_BASE;
+    c->loc.port = mg_htons(ifp->eport++);
+  }  // otherwise retain an existing bound port
 #if MG_ENABLE_IPV6
   if (c->rem.is_ip6) {
-    if (c->rem.addr.ip6[0] == ifp->ip6ll[0]) {  // same local LAN, use ll
+    if (c->loc.addr.ip6[0] == 0 && c->loc.addr.ip6[1] == 0 &&
+        c->rem.addr.ip6[0] == ifp->ip6ll[0]) {  // same local LAN, use ll
       c->loc.addr.ip6[0] = ifp->ip6ll[0], c->loc.addr.ip6[1] = ifp->ip6ll[1];
-    } else {  // use global address
+    } else if (c->loc.addr.ip6[0] == 0 && c->loc.addr.ip6[1] == 0) {
+      // Use global address
       c->loc.addr.ip6[0] = ifp->ip6[0], c->loc.addr.ip6[1] = ifp->ip6[1];
-    }
+    } // otherwise retain an existing bound address
     c->loc.is_ip6 = true;
   } else
 #endif
   {
-    c->loc.addr.ip4 = ifp->ip;
+    if (c->loc.addr.ip4 == 0) c->loc.addr.ip4 = ifp->ip;
   }
   MG_DEBUG(("%lu %M -> %M", c->id, mg_print_ip_port, &c->loc, mg_print_ip_port,
             &c->rem));
@@ -11138,11 +11160,20 @@ void mg_connect_resolved(struct mg_connection *c) {
     uint32_t rem_ip = c->rem.addr.ip4;
     if (ifp->ip && MG_IPISLOCAL(ifp, rem_ip) &&
         rem_ip != ifp->gw) {  // skip if gw (onstatechange -> ARP)
-      // If we're in the same LAN, fire an ARP lookup.
-      MG_DEBUG(("%lu ARP lookup...", c->id));
-      mg_tcpip_arp_request(ifp, rem_ip, NULL);
-      settmout(c, MIP_TTYPE_ARP);
-      c->is_arplooking = 1;
+        // We're in the same LAN
+#if MG_ENABLE_BSD_SOCKETS
+      if (c->is_bsd && c->is_udp && // see if we already have L2 data
+          (l2addr = sendto_cache_find(ifp, rem_ip)) != NULL) {
+        memcpy(s->mac, l2addr, sizeof(s->mac));
+        l2addr_resolved(c);
+      } else
+#endif
+      {  // fire an ARP lookup
+        MG_DEBUG(("%lu ARP lookup...", c->id));
+        mg_tcpip_arp_request(ifp, rem_ip, NULL);
+        settmout(c, MIP_TTYPE_ARP);
+        c->is_arplooking = 1;
+      }
     } else if (ifp->gw_ready) {
       memcpy(s->mac, ifp->gwmac, sizeof(s->mac));
       l2addr_resolved(c);
@@ -11162,13 +11193,36 @@ bool mg_open_listener(struct mg_connection *c, const char *url) {
 }
 
 static void write_conn(struct mg_connection *c) {
-  long len = c->is_tls ? mg_tls_send(c, c->send.buf, c->send.len)
-                       : mg_io_send(c, c->send.buf, c->send.len);
+  long len;
+  size_t off = 0;
+  bool empty = false;
+#if MG_ENABLE_BSD_SOCKETS
+  struct mg_bsd_udp_frame *h;
+  if (c->is_bsd && c->is_udp) {
+    if (c->is_connecting) return;
+    h = (struct mg_bsd_udp_frame *) c->send.buf;
+    assert(c->send.len >= sizeof(*h));
+    assert(h->len <= c->send.len - sizeof(*h));
+    c->rem.port = h->port;
+    c->rem.is_ip6 = false;
+    if (!c->is_client && c->rem.addr.ip4 != h->ip) {
+      c->rem.addr.ip4 = h->ip;
+      mg_connect_resolved(c);
+      if (c->is_connecting) return;
+    }
+    len = mg_io_send(c, h + 1, h->len);
+    off = sizeof(*h), empty = h->len == 0;
+  } else
+#endif
+  {
+    len = c->is_tls ? mg_tls_send(c, c->send.buf, c->send.len)
+                    : mg_io_send(c, c->send.buf, c->send.len);
+  }
   // TODO(): mg_tls_send() may return 0 forever on steady OOM
   if (len == MG_IO_ERR) {
     proto_error(c, false, "tx err");
-  } else if (len > 0) {
-    mg_iobuf_del(&c->send, 0, (size_t) len);
+  } else if (len > 0 || empty) {
+    mg_iobuf_del(&c->send, 0, off + (size_t) len);
     mg_call(c, MG_EV_WRITE, &len);
   }
 }
@@ -11528,9 +11582,7 @@ static void s_firmware_fn(struct mg_connection *c, int ev, void *ev_data) {
                (unsigned long) hm->body.len, (unsigned long) s_ota->size);
     } else {
       MG_DEBUG(("Beginning OTA (%lu bytes)", (unsigned long) s_ota->size));
-      if (!mg_http_stream_body(c, hm, s_firmware_cb, NULL)) {
-        mg_error(c, "Cannot stream firmware");
-      }
+      mg_http_stream_body(c, hm, s_firmware_cb, NULL);
     }
   } else if (ev == MG_EV_ERROR) {
     s_ota->fn((char *) ev_data);
@@ -11563,6 +11615,21 @@ void mg_ota_url_check(struct mg_mgr *mgr, const char *json_url,
   }
 }
 
+// Uses *p as a flag: non-NULL means an OTA session is open and must be
+// closed by mg_ota_end()
+bool mg_http_ota_cb(struct mg_http_message *hm, struct mg_str *data, void **p) {
+  if (hm != NULL) {  // Start
+    if (!mg_ota_begin(hm->body.len)) return false;
+    *p = (void *) (ptrdiff_t) 1;
+    return true;
+  } else if (data != NULL) {  // Next chunk
+    return mg_ota_write(data->buf, data->len);
+  }
+  if (*p == NULL) return false;  // End. Begin failed, nothing to finish
+  *p = NULL;
+  return mg_ota_end();
+}
+
 void mg_ota_poll(struct mg_mgr *mgr) {
   static uint64_t t = 5000;  // Fire first time 5 sec after boot
 
@@ -15464,7 +15531,11 @@ static long recv_raw(struct mg_connection *c, void *buf, size_t len) {
     union usa usa;
     socklen_t slen = tousa(&c->rem, &usa);
     n = recvfrom(FD(c), (char *) buf, len, 0, &usa.sa, &slen);
-    if (n > 0) tomgaddr(&usa, &c->rem, slen != sizeof(usa.sin));
+    if (n > 0) {
+      struct mg_addr rem;
+      tomgaddr(&usa, &rem, slen != sizeof(usa.sin));
+      c->rem = rem;
+    }
   } else {
     n = recv(FD(c), (char *) buf, len, MSG_NONBLOCKING);
   }
@@ -29490,8 +29561,9 @@ uint64_t mg_ntohll(uint64_t net) {
 }
 
 void mg_delayms(unsigned int ms) {
-  uint64_t to = mg_millis() + ms + 1;
-  while (mg_millis() < to) (void) 0;
+  uint64_t now, to = mg_millis() + ms + 1;
+  while ((now = mg_millis()) < to)
+    if (now + ms + 1 < to) to = now + ms + 1;
 }
 
 #if MG_ENABLE_CUSTOM_CALLOC
@@ -34618,7 +34690,7 @@ static bool st67w6_init(uint8_t *mac) {
   }
   // set clock, who cares ???
   if (!st67w6_at_cmd("AT+GET_CLOCK\r\n", 14)) return false;
-  MG_DEBUG(("%.*s", s_at_resp_len, at_resp));  // TODO(scaprile): --> VERBOSE
+  MG_VERBOSE(("%.*s", s_at_resp_len, at_resp));
   // BT-ENABLED DEPENDENCY
 
   // MODULE DEPENDENCY

mongoose.h

@@ -253,11 +253,8 @@ extern "C" {
 #include <esp_system.h>
 #include <esp_mac.h>
 #include <esp_idf_version.h>
-#if MG_ENABLE_HEALTH
-#include <esp_memory_utils.h>
-#include <esp_core_dump.h>
-#include <esp_partition.h>
-#endif
+// #include <esp_memory_utils.h>  // For health record coredumps
+// #include <esp_core_dump.h>     // For health record coredumps
 
 #define MG_PATH_MAX 128
 
@@ -2727,29 +2724,32 @@ int mg_http_status(const struct mg_http_message *hm);
 
 // Streams a POST/PUT body to a callback as it arrives, without buffering it.
 // Call it from an MG_EV_HTTP_HDRS handler, after matching the request, e.g.
-// with mg_match(). Returns true if it took over the connection, false if the
-// request is not POST/PUT, is chunked, or has no Content-Length.
+// with mg_match(). Always takes over the connection. Invalid requests receive
+// an HTTP error; client-side failures call mg_error(). Replies and connection
+// draining are handled internally, including callback failures.
 //
 // Callback upload_fn(hm, data, user_data) is called:
 //   - at start: hm is set. Open the file, set *user_data.
 //   - per chunk: data is set, 512 byte aligned except the last. Not called
 //     again after a failure.
-//   - at end: both NULL. Always called once, also when the connection drops
-//     early, so release resources here. A truncated body looks like a complete
-//     one: validate before committing.
-// Return true on success, false on error.
+//   - at end: both NULL. Always called exactly once, including validation
+//     failures before start and connections that drop early. Release resources
+//     here. A truncated body looks like a complete one: validate before
+//     committing.
+// The callback returns true on success, false on error. A failure stops
+// streaming immediately and calls the end callback before closing.
 // Example:
-//   if (ev == MG_EV_HTTP_HDRS && mg_match(hm->uri, mg_str("/fs/*"), NULL) {
-//     mg_http_stream_body(c, hm, upload, NULL));
+//   if (ev == MG_EV_HTTP_HDRS && mg_match(hm->uri, mg_str("/fs/*"), NULL)) {
+//     mg_http_stream_body(c, hm, upload, NULL);
 //   }
 // Full example:
 //   tutorials/http/file-upload-single-post
 // Related APIs:
 //   mg_http_listen(), mg_http_next_multipart()
 // Notes:
-//   After it returns true, this function hijacks the connection. Existing event
-//   handler not called, hm is invalid, c->data and c->fn_data are modified
-bool mg_http_stream_body(struct mg_connection *c, struct mg_http_message *hm,
+//   The existing event handler is no longer called. hm is invalid after this
+//   call; c->data and c->fn_data are reserved for streaming state.
+void mg_http_stream_body(struct mg_connection *c, struct mg_http_message *hm,
                          bool (*upload_fn)(struct mg_http_message *,
                                            struct mg_str *, void **user_data),
                          void *user_data);
@@ -4223,9 +4223,8 @@ bool mg_ota_end(void);
 // ```c
 // if (ev == MG_EV_HTTP_HDRS) {
 //   struct mg_http_message *hm = (struct mg_http_message *) ev_data;
-//   if (mg_match(hm->uri, mg_str("/ota"), NULL) &&
-//       !mg_http_stream_body(c, hm, mg_http_ota_cb, NULL)) {
-//     mg_http_reply(c, 400, "", "POST firmware with Content-Length\n");
+//   if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+//     mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
 //   }
 // }
 // ```
@@ -4374,8 +4373,6 @@ void mg_ota_poll(struct mg_mgr *);
 
 
 
-#if MG_ENABLE_HEALTH
-
 #ifndef MG_HEALTH_MAGIC
 #define MG_HEALTH_MAGIC {'M', 'G', 'H', '3'}  // '3' is the layout version
 #endif
@@ -4384,15 +4381,13 @@ void mg_ota_poll(struct mg_mgr *);
 #define MG_HEALTH_RAM __attribute__((section(".mg_health")))
 #endif
 
-#ifndef MG_HEALTH_DATA_SIZE
-#if (defined(STM32H7_DEV_ID) || defined(STM32H5)) || defined(STM32C5)
+#if !defined(MG_HEALTH_DATA_SIZE) && (defined(STM32H7_DEV_ID) || defined(STM32H5) || defined(STM32C5))
 #define MG_HEALTH_DATA_SIZE 250
-#elif MG_ARCH == MG_ARCH_ESP32
-#define MG_HEALTH_DATA_SIZE 23
-#else
+#endif
+
+#ifndef MG_HEALTH_DATA_SIZE
 #define MG_HEALTH_DATA_SIZE 10
 #endif
-#endif  // MG_HEALTH_DATA_SIZE
 
 // Places the record in RAM that survives a reset. Define in mongoose_config.h
 // to match the linker script, e.g. __attribute__((section(".mg_health")))
@@ -4400,13 +4395,6 @@ void mg_ota_poll(struct mg_mgr *);
 #define MG_HEALTH_RAM
 #endif
 
-// CPU core architecture
-enum mg_health_arch {
-  MG_HEALTH_ARCH_ARM = 0,
-  MG_HEALTH_ARCH_XTENSA,
-  MG_HEALTH_ARCH_RISCV
-};
-
 // Why the device restarted. Hardware usually reports several flags at once,
 // so these are ordered by how much they tell you: the most specific cause a
 // device reports wins
@@ -4423,8 +4411,7 @@ enum mg_health_reason {
 
 struct mg_health {
   char magic[4];          // MG_HEALTH_MAGIC when the record holds valid data
-  uint16_t reset_reason;  // enum mg_health_reason that started this boot
-  uint16_t arch;          // enum mg_health_arch, core architecture (ARM, etc)
+  uint32_t reset_reason;  // enum mg_health_reason that started this boot
   uint32_t cpuid;         // ARM CPU ID
   uint32_t data[MG_HEALTH_DATA_SIZE];
 };
@@ -4457,72 +4444,9 @@ static inline const char *mg_health_reason_str(int reason) {
   }
 }
 
-#if MG_ARCH == MG_ARCH_ESP32
-#ifndef CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH
-#define CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH 0
-#endif
-#ifndef ESP_PARTITION_SUBTYPE_DATA_COREDUMP
-#define ESP_PARTITION_SUBTYPE_DATA_COREDUMP 0x03
-#endif
-// clang-format off
-static inline uint16_t esp2mg(esp_reset_reason_t rr) {
-  switch(rr) {
-    case ESP_RST_POWERON: return (uint16_t) MG_HEALTH_RESET_POWER;
-#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(5, 2, 2)
-    case ESP_RST_PWR_GLITCH:
-#endif
-    case ESP_RST_BROWNOUT: return (uint16_t) MG_HEALTH_RESET_BROWNOUT;
-    case ESP_RST_EXT: return (uint16_t) MG_HEALTH_RESET_PIN;
-    case ESP_RST_SW: return (uint16_t) MG_HEALTH_RESET_SOFTWARE;
-    case ESP_RST_DEEPSLEEP: return (uint16_t) MG_HEALTH_RESET_LOWPOWER;
-    case ESP_RST_INT_WDT:
-    case ESP_RST_TASK_WDT:
-    case ESP_RST_WDT: return (uint16_t) MG_HEALTH_RESET_WATCHDOG;
-#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(5, 2, 2)
-    case ESP_RST_CPU_LOCKUP:
-#endif
-    case ESP_RST_PANIC: return (uint16_t) MG_HEALTH_RESET_FAULT;
-    default: break;
-  }
-  return (uint16_t) MG_HEALTH_RESET_UNKNOWN;
-}
-// clang-format on
-#endif
-
 #define MG_HEALTH_INIT() mg_health_init()
 extern size_t mg_print_crash_record(mg_pfn_t, void *, va_list *);
 extern void mg_health_init(void);
-extern bool mg_health_coredump_begin(size_t *size);
-extern bool mg_health_coredump_read(size_t offset, void *buf, size_t *len);
-extern bool mg_health_coredump_end(void);
-#else
-#define MG_HEALTH_INIT()
-static inline int mg_health_reason(void) {
-  return 0;
-}
-static inline const char *mg_health_reason_str(int reason) {
-  (void) reason;
-  return "unknown";
-}
-static inline size_t mg_print_crash_record(mg_pfn_t fn, void *arg,
-                                           va_list *ap) {
-  (void) ap;
-  return mg_xprintf(fn, arg, "{}");
-}
-static inline bool mg_health_coredump_begin(size_t *size) {
-  (void) size;
-  return false;
-}
-static inline bool mg_health_coredump_read(size_t offset, void *buf,
-                                           size_t *len) {
-  (void) offset, (void) buf, (void) len;
-  return false;
-}
-static inline bool mg_health_coredump_end(void) {
-  return false;
-}
-
-#endif
 // Cloud connector API to https://mdash.net - device management cloud
 
 
@@ -4696,6 +4620,17 @@ struct mg_tcpip_driver {
 typedef void (*mg_tcpip_event_handler_t)(struct mg_tcpip_if *ifp, int ev,
                                          void *ev_data);
 
+#if MG_ENABLE_BSD_SOCKETS
+#ifndef MG_TCPIP_SENDTO_CACHE_SIZE
+#define MG_TCPIP_SENDTO_CACHE_SIZE 4
+#endif
+
+struct mg_tcpip_sendto_entry {
+  uint32_t ip;
+  struct mg_l2addr addr;
+};
+#endif
+
 // clang-format off
 // Events delivered to mg_tcpip_if.fn (user) and mg_tcpip_if.pfn (driver).
 // Each entry shows the ev_data type to cast inside the handler.
@@ -4758,6 +4693,9 @@ struct mg_tcpip_if {
   enum mg_l2type l2type;                    // Layer-2 type: Ethernet, PPP, etc. (see l2.h)
   union mg_l2data l2data;                   // Layer-2 config and state (see l2.h)
   char *dns4_url;                           // Active DNS server URL (set from DHCP or config)
+#if MG_ENABLE_BSD_SOCKETS
+  struct mg_tcpip_sendto_entry sendto[MG_TCPIP_SENDTO_CACHE_SIZE];  // Local IPv4 neighbors
+#endif
   uint64_t now;                             // Current time in ms (updated each mg_mgr_poll)
   uint64_t timer_1000ms;                    // Timestamp of last 1-second tick
   uint64_t lease_expire;                    // DHCP lease expiry time in ms
@@ -4969,10 +4907,37 @@ void mg_bsd_poll(struct mg_mgr *);
 #ifndef EPIPE
 #define EPIPE 32
 #endif
+#ifndef EOPNOTSUPP
+#define EOPNOTSUPP 95
+#endif
+#ifndef EISCONN
+#define EISCONN 106
+#endif
+#ifndef EDESTADDRREQ
+#define EDESTADDRREQ 121
+#endif
+#ifndef EMSGSIZE
+#define EMSGSIZE 90
+#endif
 #ifndef EPROTONOSUPPORT
 #define EPROTONOSUPPORT 93
 #endif
 
+#if defined(__DCC__)
+#pragma pack(1)
+#else
+#pragma pack(push, 1)
+#endif
+struct mg_bsd_udp_frame {
+  uint32_t ip;
+  uint16_t port, len;
+};
+#if defined(__DCC__)
+#pragma pack(0)
+#else
+#pragma pack(pop)
+#endif
+
 #if MG_ENABLE_BSD_PROTOTYPES
 typedef unsigned int socklen_t;
 typedef unsigned long nfds_t;

src/arch_esp32.h

@@ -22,11 +22,8 @@
 #include <esp_system.h>
 #include <esp_mac.h>
 #include <esp_idf_version.h>
-#if MG_ENABLE_HEALTH
-#include <esp_memory_utils.h>
-#include <esp_core_dump.h>
-#include <esp_partition.h>
-#endif
+// #include <esp_memory_utils.h>  // For health record coredumps
+// #include <esp_core_dump.h>     // For health record coredumps
 
 #define MG_PATH_MAX 128
 

src/bsd.c

@@ -1,5 +1,6 @@
 #include "bsd.h"
 #include "dns.h"
+#include "util.h"
 #include <stdarg.h>
 
 #if MG_ENABLE_BSD_SOCKETS && MG_ENABLE_FREERTOS
@@ -110,6 +111,57 @@ static struct mg_connection *bsd_new_conn(struct mg_bsd_sock *s) {
   return c;
 }
 
+// Mirror net_builtin.c::trim_len() logic
+static bool bsd_udp_too_big(struct mg_connection *c, size_t len) {
+  struct mg_tcpip_if *ifp = c->mgr->ifp;
+  size_t hlen = c->rem.is_ip6 ? 48 : 32;  // IP plus UDP headers
+  size_t cap = ifp->mtu - hlen;
+  size_t room = ifp->tx.len - (ifp->framesize - ifp->l2mtu) - hlen;
+
+  return len > cap || len > room;
+}
+
+static bool bsd_udp_send(struct mg_connection *c, uint32_t ip, uint16_t port,
+                         const void *buf, size_t len) {
+  struct mg_bsd_udp_frame *h;
+  size_t off = c->send.len, total = sizeof(*h) + len;
+
+  if (mg_iobuf_add(&c->send, off, NULL, total) != total) return false;
+  h = (struct mg_bsd_udp_frame *) (c->send.buf + off);
+  h->ip = ip;
+  h->port = port;
+  h->len = (uint16_t) len;
+  memcpy(h + 1, buf, len);
+  return true;
+}
+
+static size_t bsd_recv(struct mg_bsd_sock *s, void *buf, size_t len,
+                       int flags, struct sockaddr *src, socklen_t *addrlen) {
+  struct mg_connection *c = s->c;
+  size_t n;
+
+  if (!s->is_udp) {
+    n = c->recv.len < len ? c->recv.len : len;
+    memcpy(buf, c->recv.buf, n);
+    if (!(flags & MSG_PEEK)) mg_iobuf_del(&c->recv, 0, n);
+  } else {
+    struct mg_bsd_udp_frame *h = (struct mg_bsd_udp_frame *) c->recv.buf;
+    assert(c->recv.len >= sizeof(*h));
+    assert(h->len <= c->recv.len - sizeof(*h));
+    n = h->len < len ? h->len : len;
+    memcpy(buf, h + 1, n);
+    if (src != NULL && addrlen != NULL) {
+      struct sockaddr_in *sa = (struct sockaddr_in *) src;
+      sa->sin_family = AF_INET;
+      sa->sin_port = h->port;
+      sa->sin_addr.s_addr = h->ip;
+      *addrlen = sizeof(*sa);
+    }
+    if (!(flags & MSG_PEEK)) mg_iobuf_del(&c->recv, 0, sizeof(*h) + h->len);
+  }
+  return n;
+}
+
 #if MG_ENABLE_FREERTOS
 // Complete operations blocked on c before Mongoose destroys it.
 static void bsd_finish_waiters(struct mg_bsd_sock *s, bool error) {
@@ -290,9 +342,9 @@ static int bsd_ready(struct mg_bsd_sock *s) {
     return 0;
   }
   if (s->c->recv.len > 0 || s->c->is_draining) ready |= BSD_READ;
-  if (!s->is_udp && !s->c->is_connecting && !s->c->is_closing &&
+  if ((s->is_udp || !s->c->is_connecting) && !s->c->is_closing &&
       !s->c->is_draining)
-    ready |= BSD_WRITE;  // Established TCP socket
+    ready |= BSD_WRITE;  // UDP socket or established TCP socket
   return ready;
 }
 
@@ -306,7 +358,7 @@ static void bsd_close(struct mg_bsd_sock *s) {
     if (t->orphan && t->listener == s) {
       if (t->c != NULL) {
         t->c->fn_data = NULL;
-        mg_close_conn(t->c);
+        t->c->is_draining = 1;
         t->c = NULL;
       }
       memset(t, 0, sizeof(*t));  // Release orphan
@@ -314,7 +366,7 @@ static void bsd_close(struct mg_bsd_sock *s) {
   }
   if (s->c != NULL) {
     s->c->fn_data = NULL;
-    mg_close_conn(s->c);
+    s->c->is_draining = 1;
     s->c = NULL;
   }
   memset(s, 0, sizeof(*s));  // Release socket
@@ -493,8 +545,8 @@ static bool bsd_run(struct mg_bsd_cmd *cmd) {
         cmd->result = -1, cmd->err = ECONNREFUSED;
         return true;
       }
-      if (!c->is_connecting) {
-        cmd->result = 0;
+      if (s->is_udp || !c->is_connecting) {
+        cmd->result = 0;  // UDP may still resolve ARP; TCP waits for SYN/SYN-ACK
         return true;
       }
       if (s->nonblock) {
@@ -518,11 +570,8 @@ static bool bsd_run(struct mg_bsd_cmd *cmd) {
         return true;
       }
       if (c->recv.len > 0) {
-        size_t n = cmd->op_recv.len;
-        if (c->recv.len < n) n = c->recv.len;
-        memcpy(cmd->op_recv.buf, c->recv.buf, n);
-        if (!(cmd->op_recv.flags & MSG_PEEK)) mg_iobuf_del(&c->recv, 0, n);
-        cmd->result = (int) n;
+        cmd->result = (int) bsd_recv(s, cmd->op_recv.buf, cmd->op_recv.len,
+                                     cmd->op_recv.flags, NULL, NULL);
         return true;
       }
       if (s->err != 0) {
@@ -543,10 +592,17 @@ static bool bsd_run(struct mg_bsd_cmd *cmd) {
     case BSD_OP_SEND:
       if ((s = bsd_get(cmd->op_send.fd)) == NULL) {
         cmd->result = -1, cmd->err = EBADF;
-      } else if ((c = s->c) == NULL || s->err != 0 || c->is_closing ||
-                 c->is_draining) {
+      } else if (s->err != 0 || s->closed ||
+                 ((c = s->c) != NULL && (c->is_closing || c->is_draining))) {
         cmd->result = -1, cmd->err = EPIPE;
-      } else if (mg_send(c, cmd->op_send.buf, cmd->op_send.len)) {
+      } else if (c == NULL || (s->is_udp && !c->is_client)) {
+        cmd->result = -1, cmd->err = s->is_udp ? EDESTADDRREQ : EPIPE;
+      } else if (s->is_udp && bsd_udp_too_big(c, cmd->op_send.len)) {
+        cmd->result = -1, cmd->err = EMSGSIZE;
+      } else if ((s->is_udp ? bsd_udp_send(c, c->rem.addr.ip4, c->rem.port,
+                                            cmd->op_send.buf, cmd->op_send.len)
+                            : mg_send(c, cmd->op_send.buf,
+                                      cmd->op_send.len))) {
         cmd->result = (int) cmd->op_send.len;
       } else if (s->nonblock || (cmd->op_send.flags & MSG_DONTWAIT)) {
         cmd->result = -1, cmd->err = EAGAIN;
@@ -561,16 +617,20 @@ static bool bsd_run(struct mg_bsd_cmd *cmd) {
     case BSD_OP_SENDTO:
       if ((s = bsd_get(cmd->op_sendto.fd)) == NULL) {
         cmd->result = -1, cmd->err = EBADF;
+      } else if (!s->is_udp) {
+        cmd->result = -1, cmd->err = EOPNOTSUPP;
       } else if ((c = s->c) == NULL || s->err != 0 || c->is_closing ||
                  c->is_draining) {
         cmd->result = -1, cmd->err = EPIPE;
+      } else if (c->is_client) {
+        cmd->result = -1, cmd->err = EISCONN;
       } else {
         const struct sockaddr_in *sa =
             (const struct sockaddr_in *) cmd->op_sendto.addr;
-        c->rem.port = sa->sin_port;
-        c->rem.addr.ip4 = sa->sin_addr.s_addr;
-        c->rem.is_ip6 = false;
-        if (mg_send(c, cmd->op_sendto.buf, cmd->op_sendto.len)) {
+        if (bsd_udp_too_big(c, cmd->op_sendto.len)) {
+          cmd->result = -1, cmd->err = EMSGSIZE;
+        } else if (bsd_udp_send(c, sa->sin_addr.s_addr, sa->sin_port,
+                                cmd->op_sendto.buf, cmd->op_sendto.len)) {
           cmd->result = (int) cmd->op_sendto.len;
         } else if (s->nonblock || (cmd->op_sendto.flags & MSG_DONTWAIT)) {
           cmd->result = -1, cmd->err = EAGAIN;
@@ -587,6 +647,9 @@ static bool bsd_run(struct mg_bsd_cmd *cmd) {
       if ((s = bsd_get(cmd->op_recvfrom.fd)) == NULL) {
         cmd->result = -1, cmd->err = EBADF;
         return true;
+      } else if (!s->is_udp) {
+        cmd->result = -1, cmd->err = EOPNOTSUPP;
+        return true;
       }
       if ((c = s->c) == NULL) {
         cmd->result = s->closed && s->err == 0 ? 0 : -1;
@@ -594,18 +657,11 @@ static bool bsd_run(struct mg_bsd_cmd *cmd) {
         return true;
       }
       if (c->recv.len > 0) {
-        size_t n = cmd->op_recvfrom.len;
-        if (c->recv.len < n) n = c->recv.len;
-        memcpy(cmd->op_recvfrom.buf, c->recv.buf, n);
-        if (!(cmd->op_recvfrom.flags & MSG_PEEK)) mg_iobuf_del(&c->recv, 0, n);
-        if (cmd->op_recvfrom.src != NULL && cmd->op_recvfrom.addrlen != NULL) {
-          struct sockaddr_in *sa = (struct sockaddr_in *) cmd->op_recvfrom.src;
-          sa->sin_family = AF_INET;
-          sa->sin_port = c->rem.port;
-          sa->sin_addr.s_addr = c->rem.addr.ip4;
-          *cmd->op_recvfrom.addrlen = sizeof(*sa);
-        }
-        cmd->result = (int) n;
+        cmd->result = (int) bsd_recv(s, cmd->op_recvfrom.buf,
+                                     cmd->op_recvfrom.len,
+                                     cmd->op_recvfrom.flags,
+                                     cmd->op_recvfrom.src,
+                                     cmd->op_recvfrom.addrlen);
         return true;
       }
       if (s->err != 0) {

src/bsd.h

@@ -55,10 +55,37 @@ void mg_bsd_poll(struct mg_mgr *);
 #ifndef EPIPE
 #define EPIPE 32
 #endif
+#ifndef EOPNOTSUPP
+#define EOPNOTSUPP 95
+#endif
+#ifndef EISCONN
+#define EISCONN 106
+#endif
+#ifndef EDESTADDRREQ
+#define EDESTADDRREQ 121
+#endif
+#ifndef EMSGSIZE
+#define EMSGSIZE 90
+#endif
 #ifndef EPROTONOSUPPORT
 #define EPROTONOSUPPORT 93
 #endif
 
+#if defined(__DCC__)
+#pragma pack(1)
+#else
+#pragma pack(push, 1)
+#endif
+struct mg_bsd_udp_frame {
+  uint32_t ip;
+  uint16_t port, len;
+};
+#if defined(__DCC__)
+#pragma pack(0)
+#else
+#pragma pack(pop)
+#endif
+
 #if MG_ENABLE_BSD_PROTOTYPES
 typedef unsigned int socklen_t;
 typedef unsigned long nfds_t;

src/dash.c

@@ -533,21 +533,6 @@ static void mg_dash_handle_add(struct mg_connection *c, struct mg_dash *dash,
   }
 }
 
-// Firmware upload callback for mg_http_stream_body(). Uses *p as a flag:
-// non-NULL means an OTA session is open and must be closed by mg_ota_end()
-static bool otacb(struct mg_http_message *hm, struct mg_str *data, void **p) {
-  if (hm != NULL) {  // Start
-    if (!mg_ota_begin(hm->body.len)) return false;
-    *p = (void *) (ptrdiff_t) 1;
-    return true;
-  } else if (data != NULL) {  // Next chunk
-    return mg_ota_write(data->buf, data->len);
-  }
-  if (*p == NULL) return false;  // End. Begin failed, nothing to finish
-  *p = NULL;
-  return mg_ota_end();
-}
-
 static void mg_serve_fs(struct mg_connection *c, struct mg_http_message *hm,
                         struct mg_dash_user *u, bool stream) {
   struct mg_dash *dash = (struct mg_dash *) c->fn_data;
@@ -594,9 +579,9 @@ void mg_dash_ev_handler(struct mg_connection *c, int ev, void *ev_data) {
       mg_serve_fs(c, hm, u, true);
       return;  // Important - the serve_fs() call can invalidate hm
     } else if (mg_match(hm->uri, mg_str("/api/ota"), NULL)) {
-      // Authenticated above. If streaming started, the stream handler owns
-      // the connection and c->data, so skip the marker check below
-      if (mg_http_stream_body(c, hm, otacb, NULL)) return;
+      // Authenticated above. Streaming owns the connection and c->data.
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+      return;
     }
     if (d->marker != '\0') mg_log_http_req(c, hm);
   } else if (ev == MG_EV_HTTP_MSG && d->marker != '\0') {

src/drivers/st67w6.c

@@ -365,7 +365,7 @@ static bool st67w6_init(uint8_t *mac) {
   }
   // set clock, who cares ???
   if (!st67w6_at_cmd("AT+GET_CLOCK\r\n", 14)) return false;
-  MG_DEBUG(("%.*s", s_at_resp_len, at_resp));  // TODO(scaprile): --> VERBOSE
+  MG_VERBOSE(("%.*s", s_at_resp_len, at_resp));
   // BT-ENABLED DEPENDENCY
 
   // MODULE DEPENDENCY

src/health.c

@@ -1,66 +1,12 @@
 #include "config.h"
 #include "health.h"
 
-#if MG_ENABLE_HEALTH
-#if MG_ARCH == MG_ARCH_ESP32
-// reusable for other platforms, currently ESP32-only
-struct mg_health_coredump {
-  const void *ptr;
-  size_t poffset;
-  size_t size;
-};
-
-static struct mg_health_coredump s_coredump;
-#endif
-
-bool mg_health_coredump_begin(size_t *size) {
-#if MG_ARCH == MG_ARCH_ESP32 && CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH
-  const esp_partition_t *p = esp_partition_find_first(
-      ESP_PARTITION_TYPE_DATA, ESP_PARTITION_SUBTYPE_DATA_COREDUMP, NULL);
-  size_t address = 0, len = 0;
-  esp_err_t err = esp_core_dump_image_get(&address, &len);
-  if (size == NULL || s_coredump.ptr != NULL || err != ESP_OK || p == NULL)
-    return false;
-  s_coredump.ptr = p;
-  s_coredump.poffset = address - p->address;
-  s_coredump.size = len;
-  *size = len;
-  return true;
-#else
-  (void) size;
-  return false;
-#endif
-}
-
-bool mg_health_coredump_read(size_t offset, void *buf, size_t *len) {
-#if MG_ARCH == MG_ARCH_ESP32 && CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH
-  const esp_partition_t *p = (const esp_partition_t *) s_coredump.ptr;
-  if (p == NULL || offset > s_coredump.size)
-    return false;
-  if (*len > s_coredump.size - offset) *len = s_coredump.size - offset;
-  return esp_partition_read(p, s_coredump.poffset + offset, buf, *len) == ESP_OK;
-#else
-  (void) offset, (void) buf, (void) len;
-  return false;
-#endif
-}
-
-bool mg_health_coredump_end(void) {
-#if MG_ARCH == MG_ARCH_ESP32 && CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH
-  bool ok = s_coredump.ptr != NULL;
-  memset(&s_coredump, 0, sizeof(s_coredump));
-  return ok;
-#else
-  return false;
-#endif
-}
-
 // The one health record. Lives in RAM that survives a warm reset, see
 // MG_HEALTH_RAM and the .mg_health region in the linker script
 struct mg_health mg_health_record MG_HEALTH_RAM;
 
-// STM32 H7, H5, C5 support. Needs the _estack symbol from the linker script
-#if defined(STM32H7_DEV_ID) || defined(STM32H5) || defined(STM32C5)
+// STM32 H723 support. Needs the _estack symbol from the linker script
+#if MG_ENABLE_HEALTH && (defined(STM32H7_DEV_ID) || defined(STM32H5) || defined(STM32C5))
 // Fault handler body. Runs in exception context: no printf, no malloc, no
 // blocking calls. Copies the unwind registers and raw stack into the health
 // record, then resets.
@@ -102,57 +48,52 @@ void BusFault_Handler(void) __attribute__((alias("HardFault_Handler")));
 void UsageFault_Handler(void) __attribute__((alias("HardFault_Handler")));
 #endif
 
-// Start a new boot: validate the record. Called by MG_HEALTH_INIT()
+// Start a new boot: validate the record, count the boot, store the reset
+// reason. The current boot moves to prev_* slots first, so the previous
+// boot's uptime and reason stay readable. Called by MG_HEALTH_INIT()
 void mg_health_init(void) {
   char magic[] = MG_HEALTH_MAGIC;
+  // struct mg_health *h = mg_health_get();
   if (!mg_health_valid()) {  // First boot, or RAM lost its contents
     memset(&mg_health_record, 0, sizeof(mg_health_record));
     memcpy(mg_health_record.magic, magic, sizeof(mg_health_record.magic));
   }
-#if MG_ARCH == MG_ARCH_ESP32
-#if CONFIG_IDF_TARGET_ARCH_XTENSA
-  mg_health_record.arch = (uint16_t) MG_HEALTH_ARCH_XTENSA;
-#elif CONFIG_IDF_TARGET_ARCH_RISCV
-  mg_health_record.arch = (uint16_t) MG_HEALTH_ARCH_RISCV;
-#endif
-  esp_reset_reason_t rr = esp_reset_reason();
-  mg_health_record.reset_reason = esp2mg(rr);
-#if CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH == 0
-  MG_ERROR(("MG_HEALTH is enabled but CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH=n"));
-#else
+
+#if 0 && MG_ARCH == MG_ARCH_ESP32 && CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH
+  {
     // After a crash, copy the backtrace from the core dump in flash: the same
     // addresses the panic handler prints as "Backtrace: PC:SP PC:SP ...".
     // The core dump stays in flash, so check the reset reason, otherwise an
     // old crash is reported on every boot
-    esp_core_dump_summary_t *s = calloc(1, sizeof(*s));
+    static esp_core_dump_summary_t s;  // Big on RISC-V, keep it off the stack
+    esp_reset_reason_t rr = esp_reset_reason();
     uint32_t *out = mg_health_record.data;
-    size_t n = 0;
+    size_t n = 0, max = MG_HEALTH_DATA_SIZE;
+    if (rr != ESP_RST_PANIC && rr != ESP_RST_INT_WDT && rr != ESP_RST_TASK_WDT)
+      return;  // Not a crash that went through the panic handler
+    if (max == 0 || esp_core_dump_get_summary(&s) != ESP_OK) return;
+
+    mg_health_record.cpuid = 42;  // ESP32
+    mg_health_record.reset_reason = MG_HEALTH_RESET_FAULT;
+
     memset(out, 0, sizeof(mg_health_record.data));
-    if (s == NULL) return;
-    if ((rr != ESP_RST_PANIC && rr != ESP_RST_INT_WDT &&
-         rr != ESP_RST_TASK_WDT)  // Not a crash caught by the panic handler
-        || esp_core_dump_get_summary(s) != ESP_OK) {
-      free(s);
-      return;
-    }
-    out[n++] = s->exc_pc;
-    memcpy(&out[n], s->exc_task, 16), n += 4;
+    out[n++] = s.exc_pc;
 #if CONFIG_IDF_TARGET_ARCH_XTENSA
-    out[n++] = s->ex_info.exc_a[0];
-    out[n++] = s->ex_info.exc_a[1];
-    size_t len = s->exc_bt_info.depth;
-    if (len > MG_HEALTH_DATA_SIZE - n) len = (MG_HEALTH_DATA_SIZE - n);
-    memcpy(&out[n], s->exc_bt_info.bt, 4 * len); // sizeof(uint32_t)
+    for (uint32_t i = 0; i < s.exc_bt_info.depth && n < max; i++) {
+      if (s.exc_bt_info.bt[i] != s.exc_pc) out[n++] = s.exc_bt_info.bt[i];
+    }
 #elif CONFIG_IDF_TARGET_ARCH_RISCV
-    out[n++] = s->ex_info.exc_ra;
-    out[n++] = s->ex_info.exc_sp;
-    size_t len = s->exc_bt_info.dump_size / 4 ; // sizeof(uint32_t)
-    if (len > MG_HEALTH_DATA_SIZE - n) len = (MG_HEALTH_DATA_SIZE - n);
-    memcpy(&out[n], s->exc_bt_info.stackdump, 4 * len);
+    // No unwinder: take the return address, then words on the stack that
+    // point into executable memory (a heuristic, may include stale values)
+    if (n < max) out[n++] = s.ex_info.ra;
+    for (uint32_t i = 0; i + 4 <= s.exc_bt_info.dump_size && n < max; i += 4) {
+      uint32_t w;
+      memcpy(&w, &s.exc_bt_info.stackdump[i], sizeof(w));  // Byte array
+      if (esp_ptr_executable((void *) (uintptr_t) w)) out[n++] = w;
+    }
+#endif
+  }
 #endif
-    free(s);
-#endif  // CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH
-#endif  // MG_ARCH_ESP32
 }
 
 static size_t print_uint32(void (*fn)(char, void *), void *arg, va_list *ap) {
@@ -166,17 +107,11 @@ static size_t print_uint32(void (*fn)(char, void *), void *arg, va_list *ap) {
 size_t mg_print_crash_record(void (*fn)(char, void *), void *arg, va_list *ap) {
   size_t len = 0;
   if (mg_health_valid() &&
-      (mg_health_record.reset_reason == (uint16_t) MG_HEALTH_RESET_FAULT
-#if MG_ARCH == MG_ARCH_ESP32
-       || mg_health_record.reset_reason == (uint16_t) MG_HEALTH_RESET_WATCHDOG
-#endif
-       )) {
+      mg_health_record.reset_reason == MG_HEALTH_RESET_FAULT) {
     size_t n = sizeof(mg_health_record.data) / sizeof(mg_health_record.data[0]);
-    len += mg_xprintf(fn, arg, "{%m:%hhu,%m:%hu,%m:%hu,%m:%u,%m:[%M]}",  //
-                      MG_ESC("version"), mg_health_record.magic[3],      //
-                      MG_ESC("arch"), mg_health_record.arch,             //
-                      MG_ESC("reason"), mg_health_record.reset_reason,   //
-                      MG_ESC("cpuid"), mg_health_record.cpuid,           //
+    len += mg_xprintf(fn, arg, "{%m:%hhu,%m:%u,%m:[%M]}",            //
+                      MG_ESC("version"), mg_health_record.magic[3],  //
+                      MG_ESC("cpuid"), mg_health_record.cpuid,       //
                       MG_ESC("data"), print_uint32, n, mg_health_record.data);
   } else {
     len += mg_xprintf(fn, arg, "{}");
@@ -184,4 +119,3 @@ size_t mg_print_crash_record(void (*fn)(char, void *), void *arg, va_list *ap) {
   (void) ap;
   return len;
 }
-#endif

src/health.h

@@ -5,8 +5,6 @@
 #include "arch.h"
 #include "printf.h"
 
-#if MG_ENABLE_HEALTH
-
 #ifndef MG_HEALTH_MAGIC
 #define MG_HEALTH_MAGIC {'M', 'G', 'H', '3'}  // '3' is the layout version
 #endif
@@ -15,15 +13,13 @@
 #define MG_HEALTH_RAM __attribute__((section(".mg_health")))
 #endif
 
-#ifndef MG_HEALTH_DATA_SIZE
-#if (defined(STM32H7_DEV_ID) || defined(STM32H5)) || defined(STM32C5)
+#if !defined(MG_HEALTH_DATA_SIZE) && (defined(STM32H7_DEV_ID) || defined(STM32H5) || defined(STM32C5))
 #define MG_HEALTH_DATA_SIZE 250
-#elif MG_ARCH == MG_ARCH_ESP32
-#define MG_HEALTH_DATA_SIZE 23
-#else
+#endif
+
+#ifndef MG_HEALTH_DATA_SIZE
 #define MG_HEALTH_DATA_SIZE 10
 #endif
-#endif  // MG_HEALTH_DATA_SIZE
 
 // Places the record in RAM that survives a reset. Define in mongoose_config.h
 // to match the linker script, e.g. __attribute__((section(".mg_health")))
@@ -31,13 +27,6 @@
 #define MG_HEALTH_RAM
 #endif
 
-// CPU core architecture
-enum mg_health_arch {
-  MG_HEALTH_ARCH_ARM = 0,
-  MG_HEALTH_ARCH_XTENSA,
-  MG_HEALTH_ARCH_RISCV
-};
-
 // Why the device restarted. Hardware usually reports several flags at once,
 // so these are ordered by how much they tell you: the most specific cause a
 // device reports wins
@@ -54,8 +43,7 @@ enum mg_health_reason {
 
 struct mg_health {
   char magic[4];          // MG_HEALTH_MAGIC when the record holds valid data
-  uint16_t reset_reason;  // enum mg_health_reason that started this boot
-  uint16_t arch;          // enum mg_health_arch, core architecture (ARM, etc)
+  uint32_t reset_reason;  // enum mg_health_reason that started this boot
   uint32_t cpuid;         // ARM CPU ID
   uint32_t data[MG_HEALTH_DATA_SIZE];
 };
@@ -88,69 +76,6 @@ static inline const char *mg_health_reason_str(int reason) {
   }
 }
 
-#if MG_ARCH == MG_ARCH_ESP32
-#ifndef CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH
-#define CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH 0
-#endif
-#ifndef ESP_PARTITION_SUBTYPE_DATA_COREDUMP
-#define ESP_PARTITION_SUBTYPE_DATA_COREDUMP 0x03
-#endif
-// clang-format off
-static inline uint16_t esp2mg(esp_reset_reason_t rr) {
-  switch(rr) {
-    case ESP_RST_POWERON: return (uint16_t) MG_HEALTH_RESET_POWER;
-#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(5, 2, 2)
-    case ESP_RST_PWR_GLITCH:
-#endif
-    case ESP_RST_BROWNOUT: return (uint16_t) MG_HEALTH_RESET_BROWNOUT;
-    case ESP_RST_EXT: return (uint16_t) MG_HEALTH_RESET_PIN;
-    case ESP_RST_SW: return (uint16_t) MG_HEALTH_RESET_SOFTWARE;
-    case ESP_RST_DEEPSLEEP: return (uint16_t) MG_HEALTH_RESET_LOWPOWER;
-    case ESP_RST_INT_WDT:
-    case ESP_RST_TASK_WDT:
-    case ESP_RST_WDT: return (uint16_t) MG_HEALTH_RESET_WATCHDOG;
-#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(5, 2, 2)
-    case ESP_RST_CPU_LOCKUP:
-#endif
-    case ESP_RST_PANIC: return (uint16_t) MG_HEALTH_RESET_FAULT;
-    default: break;
-  }
-  return (uint16_t) MG_HEALTH_RESET_UNKNOWN;
-}
-// clang-format on
-#endif
-
 #define MG_HEALTH_INIT() mg_health_init()
 extern size_t mg_print_crash_record(mg_pfn_t, void *, va_list *);
 extern void mg_health_init(void);
-extern bool mg_health_coredump_begin(size_t *size);
-extern bool mg_health_coredump_read(size_t offset, void *buf, size_t *len);
-extern bool mg_health_coredump_end(void);
-#else
-#define MG_HEALTH_INIT()
-static inline int mg_health_reason(void) {
-  return 0;
-}
-static inline const char *mg_health_reason_str(int reason) {
-  (void) reason;
-  return "unknown";
-}
-static inline size_t mg_print_crash_record(mg_pfn_t fn, void *arg,
-                                           va_list *ap) {
-  (void) ap;
-  return mg_xprintf(fn, arg, "{}");
-}
-static inline bool mg_health_coredump_begin(size_t *size) {
-  (void) size;
-  return false;
-}
-static inline bool mg_health_coredump_read(size_t offset, void *buf,
-                                           size_t *len) {
-  (void) offset, (void) buf, (void) len;
-  return false;
-}
-static inline bool mg_health_coredump_end(void) {
-  return false;
-}
-
-#endif

src/http.c

@@ -879,8 +879,8 @@ void mg_http_serve_upload(struct mg_connection *c, struct mg_http_message *hm,
     fs->rm(path);  // MG_FS_WRITE appends, not truncates: drop any old file
     if ((fd = mg_fs_open(fs, path, MG_FS_WRITE)) == NULL) {
       MG_ERROR(("Cannot open %s for upload", path));
-    } else if (!mg_http_stream_body(c, hm, serve_upload_cb, fd)) {
-      mg_fs_close(fd);
+    } else {
+      mg_http_stream_body(c, hm, serve_upload_cb, fd);
     }
   }
 }
@@ -1014,6 +1014,7 @@ struct mg_upload_state {
   size_t received;  // Number of body bytes received so far
   void *user_data;  // Passed to cb, free for cb to use
   bool failed;      // Set when cb returned false
+  bool finished;    // End callback has been called
 };
 
 // Event handler installed by mg_http_stream_body(). Feeds the body to the
@@ -1021,18 +1022,18 @@ struct mg_upload_state {
 // handler: the connection is closed after the reply.
 static void mg_stream_handler(struct mg_connection *c, int ev, void *ev_data) {
   struct mg_upload_state *us = (struct mg_upload_state *) c->data;
-    bool (*fn)(struct mg_http_message *, struct mg_str *, void **) =
+  bool (*fn)(struct mg_http_message *, struct mg_str *, void **) =
       (bool (*)(struct mg_http_message *, struct mg_str *, void **))
       (ptrdiff_t) c->fn_data;
   (void) ev_data;
   if (ev == MG_EV_CLOSE || ev == MG_EV_ERROR) {
-    if (us->received < us->expected) {
+    if (!us->finished) {
       // Connection dropped mid-upload. Let cb clean up, e.g. call mg_ota_end()
-      us->received = us->expected;  // MG_EV_ERROR is followed by MG_EV_CLOSE
+      us->finished = true;  // MG_EV_ERROR is followed by MG_EV_CLOSE
       fn(NULL, NULL, &us->user_data);
     }
-  } else if (ev == MG_EV_READ && !c->is_draining) {
-    if (c->recv.len > 0 && us->received < us->expected) {
+  } else if (ev == MG_EV_READ && !c->is_draining && !us->finished) {
+    if (!us->failed && c->recv.len > 0 && us->received < us->expected) {
       // Got some uploaded data. Feed by 512-byte aligned chunks, for OTA
       size_t left = us->expected - us->received, r = c->recv.len;
       size_t aligned = r < left ? MG_ROUND_DOWN(r, 512) : left;
@@ -1043,10 +1044,13 @@ static void mg_stream_handler(struct mg_connection *c, int ev, void *ev_data) {
       us->received += aligned;
       mg_iobuf_del(&c->recv, 0, aligned);  // Shift the unprocessed tail
     }
-    if (us->received >= us->expected) {
+    if (!us->finished && (us->failed || us->received >= us->expected)) {
       // Finished upload. Always call cb, even after error, so it can clean up
+      us->finished = true;
       us->failed |= !fn(NULL, NULL, &us->user_data);
-      if (!c->is_client) {
+      if (c->is_client && us->failed) {
+        mg_error(c, "Body streaming failed");
+      } else if (!c->is_client) {
         mg_http_reply(c, us->failed ? 500 : 200, NULL, "%zu %s\n",
                       us->received, us->failed ? "fail" : "ok");
       }
@@ -1055,48 +1059,54 @@ static void mg_stream_handler(struct mg_connection *c, int ev, void *ev_data) {
   }
 }
 
-bool mg_http_stream_body(struct mg_connection *c, struct mg_http_message *hm,
+void mg_http_stream_body(struct mg_connection *c, struct mg_http_message *hm,
                          bool (*cb)(struct mg_http_message *, struct mg_str *,
-                                    void **user_data),
+                                    void **),
                          void *user_data) {
   struct mg_upload_state *us = (struct mg_upload_state *) c->data;
-  struct mg_str *te = mg_http_get_header(hm, "Transfer-Encoding");
-  bool handled = false;
+  int code = 0;
+  size_t head_len = hm->head.len;
 
   // Catch upload requests early, without buffering whole body. Called on the
   // MG_EV_HTTP_HDRS event: we've received all HTTP headers but not necessarily
   // the full HTTP body
-  if (hm->body.len == (size_t) ~0 ||
-      (te != NULL && mg_strcasecmp(*te, mg_str("chunked")) == 0)) {
-    // Unknown length or chunked, cannot stream. Leave it to the caller
-  } else if (!c->is_client &&
-             mg_strcmp(hm->method, mg_str("POST")) != 0 &&
-             mg_strcmp(hm->method, mg_str("PUT")) != 0) {
-    // Not an upload request. Leave it to the caller
+  if (!c->is_client && mg_strcmp(hm->method, mg_str("POST")) != 0 &&
+      mg_strcmp(hm->method, mg_str("PUT")) != 0) {
+    code = 405;
+  } else if (mg_http_get_header(hm, "Transfer-Encoding") != NULL) {
+    code = 400;
+  } else if (hm->body.len == (size_t) ~0 ||
+             (!c->is_client && mg_http_get_header(hm, "Content-Length") == NULL)) {
+    code = 411;
   } else if (sizeof(*us) > sizeof(c->data)) {
-    if (!c->is_client) {  // Nobody to reply to on a client connection
-      c->pfn = NULL;
-      mg_http_reply(c, 500, NULL, "data too small\n");
-      c->is_draining = 1;
-      cb(NULL, NULL, &user_data);  // Let cb release user_data, start skipped
-      handled = true;
+    code = 500;
+  }
+  c->pfn = NULL;  // Take ownership even when validation fails
+  if (code != 0) {
+    c->fn = NULL;
+    c->fn_data = NULL;
+    mg_iobuf_del(&c->recv, 0, c->recv.len);
+    cb(NULL, NULL, &user_data);  // Release resources even if start was skipped
+    if (c->is_client) {
+      mg_error(c, "%s", mg_http_status_code_str(code));
+    } else {
+      mg_http_reply(c, code, code == 405 ? "Allow: POST, PUT\r\n" : NULL, "");
     }
+    c->is_draining = 1;
   } else {
-    c->pfn = NULL;  // Silence HTTP protocol handler
     memset(us, 0, sizeof(*us));
     us->expected = hm->body.len;  // Store number of bytes we expect
     us->user_data = user_data;
+    c->fn = mg_stream_handler;
+    c->fn_data = (void *) (ptrdiff_t) cb;
     us->failed = !cb(hm, NULL, &us->user_data);  // Call before deleting headers
-    if (mg_http_get_header(hm, "Expect") != NULL) {
+    if (!c->is_client && !us->failed && !us->finished &&
+        mg_http_get_header(hm, "Expect") != NULL) {
       mg_http_reply(c, 100, NULL, "");  // If curl expects, we continue
     }
-    mg_iobuf_del(&c->recv, 0, hm->head.len);  // Delete HTTP headers
-    c->fn = mg_stream_handler;                // We own the connection from now
-    c->fn_data = (void *) (ptrdiff_t) cb;
+    mg_iobuf_del(&c->recv, 0, head_len);  // Delete HTTP headers
     mg_call(c, MG_EV_READ, &c->recv.len);  // Process the body bytes we have
-    handled = true;
   }
-  return handled;
 }
 
 static bool is_hex_digit(int c) {

src/http.h

@@ -205,29 +205,32 @@ int mg_http_status(const struct mg_http_message *hm);
 
 // Streams a POST/PUT body to a callback as it arrives, without buffering it.
 // Call it from an MG_EV_HTTP_HDRS handler, after matching the request, e.g.
-// with mg_match(). Returns true if it took over the connection, false if the
-// request is not POST/PUT, is chunked, or has no Content-Length.
+// with mg_match(). Always takes over the connection. Invalid requests receive
+// an HTTP error; client-side failures call mg_error(). Replies and connection
+// draining are handled internally, including callback failures.
 //
 // Callback upload_fn(hm, data, user_data) is called:
 //   - at start: hm is set. Open the file, set *user_data.
 //   - per chunk: data is set, 512 byte aligned except the last. Not called
 //     again after a failure.
-//   - at end: both NULL. Always called once, also when the connection drops
-//     early, so release resources here. A truncated body looks like a complete
-//     one: validate before committing.
-// Return true on success, false on error.
+//   - at end: both NULL. Always called exactly once, including validation
+//     failures before start and connections that drop early. Release resources
+//     here. A truncated body looks like a complete one: validate before
+//     committing.
+// The callback returns true on success, false on error. A failure stops
+// streaming immediately and calls the end callback before closing.
 // Example:
-//   if (ev == MG_EV_HTTP_HDRS && mg_match(hm->uri, mg_str("/fs/*"), NULL) {
-//     mg_http_stream_body(c, hm, upload, NULL));
+//   if (ev == MG_EV_HTTP_HDRS && mg_match(hm->uri, mg_str("/fs/*"), NULL)) {
+//     mg_http_stream_body(c, hm, upload, NULL);
 //   }
 // Full example:
 //   tutorials/http/file-upload-single-post
 // Related APIs:
 //   mg_http_listen(), mg_http_next_multipart()
 // Notes:
-//   After it returns true, this function hijacks the connection. Existing event
-//   handler not called, hm is invalid, c->data and c->fn_data are modified
-bool mg_http_stream_body(struct mg_connection *c, struct mg_http_message *hm,
+//   The existing event handler is no longer called. hm is invalid after this
+//   call; c->data and c->fn_data are reserved for streaming state.
+void mg_http_stream_body(struct mg_connection *c, struct mg_http_message *hm,
                          bool (*upload_fn)(struct mg_http_message *,
                                            struct mg_str *, void **user_data),
                          void *user_data);

src/l2_802154.c

@@ -11,7 +11,7 @@
 #define MGI_802154_DATA (125 - MGI_802154_HDR)
 
 size_t mg_l2_802154_tx(struct mg_tcpip_if *ifp, const void *buf, size_t len,
-                       size_t (*send)(const uint8_t *, size_t,
+                       size_t (*send_fn)(const uint8_t *, size_t,
                                       struct mg_tcpip_if *)) {
   struct mg_l2_802154_data *d =
       (struct mg_l2_802154_data *) ifp->driver_data;
@@ -29,7 +29,7 @@ size_t mg_l2_802154_tx(struct mg_tcpip_if *ifp, const void *buf, size_t len,
     f[12] = m[2], f[13] = m[1], f[14] = m[0];  // Little endian EUI-64
     f[15] = d->tag, f[16] = (uint8_t) ((i << 4) | last);
     memcpy(f + MGI_802154_HDR, p + i * MGI_802154_DATA, n);
-    if (send(f, MGI_802154_HDR + n, ifp) == 0) return 0;
+    if (send_fn(f, MGI_802154_HDR + n, ifp) == 0) return 0;
   }
   return len;
 }

src/mdash.c

@@ -89,7 +89,6 @@ static void mg_mdash_fn(struct mg_connection *c, int ev, void *ev_data) {
     }
     mg_iobuf_free(&io);
   } else if (ev == MG_EV_CLOSE) {
-    mg_health_coredump_end();
     mg_mdash_conn = NULL;
     MG_INFO(("disconnected, ram %lu", 0));
   }
@@ -147,35 +146,6 @@ static void mg_mdash_rpc_ota_end(struct mg_rpc_req *r) {
   // MG_ESC("percent"));
 }
 
-static void rpc_coredump_begin(struct mg_rpc_req *r) {
-  size_t size = 0;
-  if (mg_health_coredump_begin(&size)) {
-    mg_rpc_ok(r, "{%m:%llu}", MG_ESC("size"), (uint64_t) size);
-  } else {
-    mg_rpc_err(r, 500, "%m", MG_ESC("failed"));
-  }
-}
-
-static void rpc_coredump_read(struct mg_rpc_req *r) {
-  uint8_t buf[768];
-  size_t len = sizeof(buf);
-  size_t offset = (size_t) mg_json_get_long(r->frame, "$.params.offset", -1);
-  if (mg_health_coredump_read(offset, buf, &len)) {
-    mg_rpc_ok(r, "{%m:\"%M\"}", MG_ESC("data"), mg_print_base64,
-              (int) len, buf);
-  } else {
-    mg_rpc_err(r, 500, "%m", MG_ESC("failed"));
-  }
-}
-
-static void rpc_coredump_end(struct mg_rpc_req *r) {
-  if (mg_health_coredump_end()) {
-    mg_rpc_ok(r, "true");
-  } else {
-    mg_rpc_err(r, 500, "%m", MG_ESC("failed"));
-  }
-}
-
 void mg_mdash_init(struct mg_mgr *mgr) {
   MG_INFO(("Initialising mdash agent, key [%s]", MG_MDASH_KEY));
   mg_rpc_add(&mgr->rpcs, mg_str("RPC.List"), mg_rpc_list, NULL);
@@ -183,9 +153,6 @@ void mg_mdash_init(struct mg_mgr *mgr) {
   mg_rpc_add(&mgr->rpcs, mg_str("OTA.Begin"), mg_mdash_rpc_ota_begin, NULL);
   mg_rpc_add(&mgr->rpcs, mg_str("OTA.Write"), mg_mdash_rpc_ota_write, NULL);
   mg_rpc_add(&mgr->rpcs, mg_str("OTA.End"), mg_mdash_rpc_ota_end, NULL);
-  mg_rpc_add(&mgr->rpcs, mg_str("CoreDump.Begin"), rpc_coredump_begin, NULL);
-  mg_rpc_add(&mgr->rpcs, mg_str("CoreDump.Read"), rpc_coredump_read, NULL);
-  mg_rpc_add(&mgr->rpcs, mg_str("CoreDump.End"), rpc_coredump_end, NULL);
 }
 
 void mg_mdash_poll(struct mg_mgr *mgr) {

src/net_builtin.c

@@ -609,6 +609,36 @@ static void l2addr_resolved(struct mg_connection *c);
 static uint8_t *get_return_l2addr(struct mg_tcpip_if *ifp, struct mg_addr *rem,
                                   bool is_udp, struct pkt *pkt);
 
+#if MG_ENABLE_BSD_SOCKETS
+static uint8_t *sendto_cache_find(struct mg_tcpip_if *ifp, uint32_t ip) {
+  struct mg_tcpip_sendto_entry *a;
+  for (a = ifp->sendto; a < ifp->sendto + MG_TCPIP_SENDTO_CACHE_SIZE; a++) {
+    if (a->ip == ip) return (uint8_t *) &a->addr;
+  }
+  return NULL;
+}
+
+static void sendto_cache_add(struct mg_tcpip_if *ifp, uint32_t ip,
+                             const uint8_t *addr) {
+  struct mg_tcpip_sendto_entry *a;
+  for (a = ifp->sendto; a < ifp->sendto + MG_TCPIP_SENDTO_CACHE_SIZE; a++) {
+    if (a->ip == ip) return;  // already cached, skip
+    if (a->ip == 0) break;    // not present, first empty slot
+  }
+  if (a == ifp->sendto + MG_TCPIP_SENDTO_CACHE_SIZE) { // no room
+    memmove(ifp->sendto, ifp->sendto + 1,
+            sizeof(ifp->sendto[0]) * (MG_TCPIP_SENDTO_CACHE_SIZE - 1));
+    a--; // make room and point to last entry (just made)
+  }
+  a->ip = ip; // populate this entry
+  memcpy(&a->addr, addr, sizeof(a->addr));
+}
+
+static void sendto_cache_clear(struct mg_tcpip_if *ifp) {
+  memset(ifp->sendto, 0, sizeof(ifp->sendto));
+}
+#endif
+
 // RFC826, ARP assumes Ethernet MAC addresses
 static void rx_arp(struct mg_tcpip_if *ifp, struct pkt *pkt) {
   if (pkt->arp->op == mg_htons(1) && pkt->arp->tpa == ifp->ip) {
@@ -1214,30 +1244,57 @@ static void proto_error(struct mg_connection *c, bool r, const char *f, ...) {
 static bool rx_udp(struct mg_tcpip_if *ifp, struct pkt *pkt) {
   struct mg_connection *c = getpeer(ifp->mgr, pkt, true);
   struct connstate *s;
+  struct mg_addr rem;
   uint8_t *l2addr;
+  size_t len = pkt->pay.len;
   if (c == NULL) return false;  // No UDP listener on this port
   s = (struct connstate *) (c + 1);
-  c->rem.port = pkt->udp->sport;
 #if MG_ENABLE_IPV6
   if (c->loc.is_ip6) {  // matching of v4/v6 to dest is done bt getpeer()
     if (!udp6csum_ok(pkt->ip6, pkt->udp)) return false;
-    c->rem.addr.ip6[0] = pkt->ip6->src[0],
-    c->rem.addr.ip6[1] = pkt->ip6->src[1], c->rem.is_ip6 = true;
+    if (c->is_bsd && c->is_client &&
+        (c->rem.port != pkt->udp->sport ||
+         !MG_IP6MATCH(c->rem.addr.ip6, pkt->ip6->src)))
+      return true;
+    rem.addr.ip6[0] = pkt->ip6->src[0],
+    rem.addr.ip6[1] = pkt->ip6->src[1], rem.is_ip6 = true;
   } else
 #endif
   {
     if (!udpcsum_ok(pkt->ip, pkt->udp)) return false;
-    c->rem.addr.ip4 = pkt->ip->src;
+    if (c->is_bsd && c->is_client &&
+        (c->rem.port != pkt->udp->sport || c->rem.addr.ip4 != pkt->ip->src))
+      return true;
+    rem.addr.ip4 = pkt->ip->src, rem.is_ip6 = false;
   }
-  if ((l2addr = get_return_l2addr(ifp, &c->rem, true, pkt)) == NULL)
+  rem.port = pkt->udp->sport;
+  if (!c->is_bsd || c->is_client) c->rem = rem;
+  if ((l2addr = get_return_l2addr(ifp, &rem, true, pkt)) == NULL)
     return false;  // safety net for lousy networks
-  memcpy(s->mac, l2addr, sizeof(s->mac));
+  if (!c->is_bsd || c->is_client) memcpy(s->mac, l2addr, sizeof(s->mac));
+#if MG_ENABLE_BSD_SOCKETS
+  if (c->is_bsd && !rem.is_ip6 && MG_IPISLOCAL(ifp, rem.addr.ip4))
+    sendto_cache_add(ifp, rem.addr.ip4, l2addr);
+#endif
+#if MG_ENABLE_BSD_SOCKETS
+  if (c->is_bsd) len += sizeof(struct mg_bsd_udp_frame);
+#endif
   if (c->recv.len >= MG_MAX_RECV_SIZE) {
     proto_error(c, false, "max_recv_buf_size reached");
-  } else if (c->recv.size - c->recv.len < pkt->pay.len &&
-             !mg_iobuf_resize(&c->recv, c->recv.len + pkt->pay.len)) {
+  } else if (c->recv.size - c->recv.len < len &&
+             !mg_iobuf_resize(&c->recv, c->recv.len + len)) {
     proto_error(c, false, "oom");
   } else {
+#if MG_ENABLE_BSD_SOCKETS
+    if (c->is_bsd) {
+      struct mg_bsd_udp_frame *h =
+          (struct mg_bsd_udp_frame *) &c->recv.buf[c->recv.len];
+      h->ip = rem.addr.ip4;
+      h->port = rem.port;
+      h->len = (uint16_t) pkt->pay.len;
+      c->recv.len += sizeof(*h);
+    }
+#endif
     memcpy(&c->recv.buf[c->recv.len], pkt->pay.buf, pkt->pay.len);
     c->recv.len += pkt->pay.len;
     mg_call(c, MG_EV_READ, &pkt->pay.len);
@@ -2290,6 +2347,9 @@ void mg_tcpip_init(struct mg_mgr *mgr, struct mg_tcpip_if *ifp) {
 
 static void close_conn(struct mg_connection *c) {
   struct connstate *s = (struct connstate *) (c + 1);
+#if MG_ENABLE_BSD_SOCKETS
+  if (c->is_bsd && c->is_udp) sendto_cache_clear(c->mgr->ifp);
+#endif
   mg_iobuf_free(&s->txq);
   mg_close_conn(c);
 }
@@ -2311,6 +2371,11 @@ static void send_syn(struct mg_connection *c) {
 static void l2addr_resolved(struct mg_connection *c) {
   if (c->is_udp) {
     c->is_connecting = 0;
+#if MG_ENABLE_BSD_SOCKETS
+    if (c->is_bsd)
+      sendto_cache_add(c->mgr->ifp, c->rem.addr.ip4,
+                       ((struct connstate *) (c + 1))->mac);
+#endif
     mg_call(c, MG_EV_CONNECT, NULL);
   } else {
     send_syn(c);
@@ -2325,20 +2390,25 @@ void mg_connect_resolved(struct mg_connection *c) {
   s->retransmit = ifp->enable_tcp_retransmit;
   s->txq.align = MG_TCPIP_TXQ_ALIGN;
   c->is_resolving = 0;
-  if (ifp->eport < MG_EPHEMERAL_PORT_BASE) ifp->eport = MG_EPHEMERAL_PORT_BASE;
-  c->loc.port = mg_htons(ifp->eport++);
+  if (c->loc.port == 0) {
+    if (ifp->eport < MG_EPHEMERAL_PORT_BASE)
+      ifp->eport = MG_EPHEMERAL_PORT_BASE;
+    c->loc.port = mg_htons(ifp->eport++);
+  }  // otherwise retain an existing bound port
 #if MG_ENABLE_IPV6
   if (c->rem.is_ip6) {
-    if (c->rem.addr.ip6[0] == ifp->ip6ll[0]) {  // same local LAN, use ll
+    if (c->loc.addr.ip6[0] == 0 && c->loc.addr.ip6[1] == 0 &&
+        c->rem.addr.ip6[0] == ifp->ip6ll[0]) {  // same local LAN, use ll
       c->loc.addr.ip6[0] = ifp->ip6ll[0], c->loc.addr.ip6[1] = ifp->ip6ll[1];
-    } else {  // use global address
+    } else if (c->loc.addr.ip6[0] == 0 && c->loc.addr.ip6[1] == 0) {
+      // Use global address
       c->loc.addr.ip6[0] = ifp->ip6[0], c->loc.addr.ip6[1] = ifp->ip6[1];
-    }
+    } // otherwise retain an existing bound address
     c->loc.is_ip6 = true;
   } else
 #endif
   {
-    c->loc.addr.ip4 = ifp->ip;
+    if (c->loc.addr.ip4 == 0) c->loc.addr.ip4 = ifp->ip;
   }
   MG_DEBUG(("%lu %M -> %M", c->id, mg_print_ip_port, &c->loc, mg_print_ip_port,
             &c->rem));
@@ -2369,11 +2439,20 @@ void mg_connect_resolved(struct mg_connection *c) {
     uint32_t rem_ip = c->rem.addr.ip4;
     if (ifp->ip && MG_IPISLOCAL(ifp, rem_ip) &&
         rem_ip != ifp->gw) {  // skip if gw (onstatechange -> ARP)
-      // If we're in the same LAN, fire an ARP lookup.
-      MG_DEBUG(("%lu ARP lookup...", c->id));
-      mg_tcpip_arp_request(ifp, rem_ip, NULL);
-      settmout(c, MIP_TTYPE_ARP);
-      c->is_arplooking = 1;
+        // We're in the same LAN
+#if MG_ENABLE_BSD_SOCKETS
+      if (c->is_bsd && c->is_udp && // see if we already have L2 data
+          (l2addr = sendto_cache_find(ifp, rem_ip)) != NULL) {
+        memcpy(s->mac, l2addr, sizeof(s->mac));
+        l2addr_resolved(c);
+      } else
+#endif
+      {  // fire an ARP lookup
+        MG_DEBUG(("%lu ARP lookup...", c->id));
+        mg_tcpip_arp_request(ifp, rem_ip, NULL);
+        settmout(c, MIP_TTYPE_ARP);
+        c->is_arplooking = 1;
+      }
     } else if (ifp->gw_ready) {
       memcpy(s->mac, ifp->gwmac, sizeof(s->mac));
       l2addr_resolved(c);
@@ -2393,13 +2472,36 @@ bool mg_open_listener(struct mg_connection *c, const char *url) {
 }
 
 static void write_conn(struct mg_connection *c) {
-  long len = c->is_tls ? mg_tls_send(c, c->send.buf, c->send.len)
-                       : mg_io_send(c, c->send.buf, c->send.len);
+  long len;
+  size_t off = 0;
+  bool empty = false;
+#if MG_ENABLE_BSD_SOCKETS
+  struct mg_bsd_udp_frame *h;
+  if (c->is_bsd && c->is_udp) {
+    if (c->is_connecting) return;
+    h = (struct mg_bsd_udp_frame *) c->send.buf;
+    assert(c->send.len >= sizeof(*h));
+    assert(h->len <= c->send.len - sizeof(*h));
+    c->rem.port = h->port;
+    c->rem.is_ip6 = false;
+    if (!c->is_client && c->rem.addr.ip4 != h->ip) {
+      c->rem.addr.ip4 = h->ip;
+      mg_connect_resolved(c);
+      if (c->is_connecting) return;
+    }
+    len = mg_io_send(c, h + 1, h->len);
+    off = sizeof(*h), empty = h->len == 0;
+  } else
+#endif
+  {
+    len = c->is_tls ? mg_tls_send(c, c->send.buf, c->send.len)
+                    : mg_io_send(c, c->send.buf, c->send.len);
+  }
   // TODO(): mg_tls_send() may return 0 forever on steady OOM
   if (len == MG_IO_ERR) {
     proto_error(c, false, "tx err");
-  } else if (len > 0) {
-    mg_iobuf_del(&c->send, 0, (size_t) len);
+  } else if (len > 0 || empty) {
+    mg_iobuf_del(&c->send, 0, off + (size_t) len);
     mg_call(c, MG_EV_WRITE, &len);
   }
 }

src/net_builtin.h

@@ -26,6 +26,17 @@ struct mg_tcpip_driver {
 typedef void (*mg_tcpip_event_handler_t)(struct mg_tcpip_if *ifp, int ev,
                                          void *ev_data);
 
+#if MG_ENABLE_BSD_SOCKETS
+#ifndef MG_TCPIP_SENDTO_CACHE_SIZE
+#define MG_TCPIP_SENDTO_CACHE_SIZE 4
+#endif
+
+struct mg_tcpip_sendto_entry {
+  uint32_t ip;
+  struct mg_l2addr addr;
+};
+#endif
+
 // clang-format off
 // Events delivered to mg_tcpip_if.fn (user) and mg_tcpip_if.pfn (driver).
 // Each entry shows the ev_data type to cast inside the handler.
@@ -88,6 +99,9 @@ struct mg_tcpip_if {
   enum mg_l2type l2type;                    // Layer-2 type: Ethernet, PPP, etc. (see l2.h)
   union mg_l2data l2data;                   // Layer-2 config and state (see l2.h)
   char *dns4_url;                           // Active DNS server URL (set from DHCP or config)
+#if MG_ENABLE_BSD_SOCKETS
+  struct mg_tcpip_sendto_entry sendto[MG_TCPIP_SENDTO_CACHE_SIZE];  // Local IPv4 neighbors
+#endif
   uint64_t now;                             // Current time in ms (updated each mg_mgr_poll)
   uint64_t timer_1000ms;                    // Timestamp of last 1-second tick
   uint64_t lease_expire;                    // DHCP lease expiry time in ms

src/ota.c

@@ -208,9 +208,7 @@ static void s_firmware_fn(struct mg_connection *c, int ev, void *ev_data) {
                (unsigned long) hm->body.len, (unsigned long) s_ota->size);
     } else {
       MG_DEBUG(("Beginning OTA (%lu bytes)", (unsigned long) s_ota->size));
-      if (!mg_http_stream_body(c, hm, s_firmware_cb, NULL)) {
-        mg_error(c, "Cannot stream firmware");
-      }
+      mg_http_stream_body(c, hm, s_firmware_cb, NULL);
     }
   } else if (ev == MG_EV_ERROR) {
     s_ota->fn((char *) ev_data);
@@ -243,6 +241,21 @@ void mg_ota_url_check(struct mg_mgr *mgr, const char *json_url,
   }
 }
 
+// Uses *p as a flag: non-NULL means an OTA session is open and must be
+// closed by mg_ota_end()
+bool mg_http_ota_cb(struct mg_http_message *hm, struct mg_str *data, void **p) {
+  if (hm != NULL) {  // Start
+    if (!mg_ota_begin(hm->body.len)) return false;
+    *p = (void *) (ptrdiff_t) 1;
+    return true;
+  } else if (data != NULL) {  // Next chunk
+    return mg_ota_write(data->buf, data->len);
+  }
+  if (*p == NULL) return false;  // End. Begin failed, nothing to finish
+  *p = NULL;
+  return mg_ota_end();
+}
+
 void mg_ota_poll(struct mg_mgr *mgr) {
   static uint64_t t = 5000;  // Fire first time 5 sec after boot
 

src/ota.h

@@ -80,9 +80,8 @@ bool mg_ota_end(void);
 // ```c
 // if (ev == MG_EV_HTTP_HDRS) {
 //   struct mg_http_message *hm = (struct mg_http_message *) ev_data;
-//   if (mg_match(hm->uri, mg_str("/ota"), NULL) &&
-//       !mg_http_stream_body(c, hm, mg_http_ota_cb, NULL)) {
-//     mg_http_reply(c, 400, "", "POST firmware with Content-Length\n");
+//   if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+//     mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
 //   }
 // }
 // ```

src/sock.c

@@ -299,7 +299,11 @@ static long recv_raw(struct mg_connection *c, void *buf, size_t len) {
     union usa usa;
     socklen_t slen = tousa(&c->rem, &usa);
     n = recvfrom(FD(c), (char *) buf, len, 0, &usa.sa, &slen);
-    if (n > 0) tomgaddr(&usa, &c->rem, slen != sizeof(usa.sin));
+    if (n > 0) {
+      struct mg_addr rem;
+      tomgaddr(&usa, &rem, slen != sizeof(usa.sin));
+      c->rem = rem;
+    }
   } else {
     n = recv(FD(c), (char *) buf, len, MSG_NONBLOCKING);
   }

src/util.c

@@ -261,8 +261,9 @@ uint64_t mg_ntohll(uint64_t net) {
 }
 
 void mg_delayms(unsigned int ms) {
-  uint64_t to = mg_millis() + ms + 1;
-  while (mg_millis() < to) (void) 0;
+  uint64_t now, to = mg_millis() + ms + 1;
+  while ((now = mg_millis()) < to)
+    if (now + ms + 1 < to) to = now + ms + 1;
 }
 
 #if MG_ENABLE_CUSTOM_CALLOC

test/bsd/Makefile

@@ -13,7 +13,7 @@ else
 C_WARN ?= -Wno-deprecated
 endif
 
-.PHONY: all bsd bsd_test bsd_client bsd_nortos bsd_nortos_test shm_tap_bridge \
+.PHONY: all bsd bsd_test bsd_client bsd_udp bsd_nortos bsd_nortos_test shm_tap_bridge \
         shm_port_bridge bsd_s390 bsd_nortos_s390 clean
 
 TEST_SOURCES = bsd_shm_test.c
@@ -47,11 +47,11 @@ DOCKER ?= $(DOCKER_BIN) run --platform linux/amd64 --net=host --rm $(ENV) -v $(R
 CFLAGS_MONGOOSE += -DMG_ARCH=MG_ARCH_CUSTOM
 
 
-all bsd: shm_tap_bridge bsd_client FreeRTOS-Kernel bsd_test
+all bsd: shm_tap_bridge bsd_client bsd_udp FreeRTOS-Kernel bsd_test
 	ASAN_OPTIONS=$(ASAN_OPTIONS) $(RUN) ./bsd_test $(ARGS)
 
 # also
-bsd_nortos: shm_tap_bridge bsd_client bsd_nortos_test
+bsd_nortos: shm_tap_bridge bsd_client bsd_udp bsd_nortos_test
 	ASAN_OPTIONS=$(ASAN_OPTIONS) $(RUN) ./bsd_nortos_test $(ARGS)
 
 # requires shm_tap_bridge to be running
@@ -70,6 +70,9 @@ bsd_nortos_test:
 bsd_client: bsd_client.c
 	$(CC) bsd_client.c -pthread -o $@
 
+bsd_udp: bsd_udp.c
+	$(CC) bsd_udp.c -o $@
+
 # bridge shm queue <--> TAP interface
 shm_tap_bridge: shm_tap_bridge.c shm_queue.h
 	$(CC) shm_tap_bridge.c -pthread -o $@
@@ -79,7 +82,7 @@ bsd_s390: CFLAGS_MONGOOSE += -DMG_ENABLE_BSD_PROTOTYPES=0
 bsd_s390: ASAN=
 bsd_s390: CC = $(DOCKER) mdashnet/s390 cc
 bsd_s390: RUN = $(DOCKER) --init mdashnet/s390
-bsd_s390: shm_port_bridge bsd_client FreeRTOS-Kernel bsd_test
+bsd_s390: shm_port_bridge bsd_client bsd_udp FreeRTOS-Kernel bsd_test
 	$(RUN) sh -c './shm_port_bridge & pid=$$!; sleep 1; ./bsd_test; rc=$$?; kill $$pid >/dev/null 2>&1; wait $$pid >/dev/null 2>&1; exit $$rc'
 
 #also
@@ -87,14 +90,14 @@ bsd_nortos_s390: CFLAGS_MONGOOSE += -DMG_ENABLE_BSD_PROTOTYPES=0
 bsd_nortos_s390: ASAN=
 bsd_nortos_s390: CC = $(DOCKER) mdashnet/s390 cc
 bsd_nortos_s390: RUN = $(DOCKER) --init mdashnet/s390
-bsd_nortos_s390: shm_port_bridge bsd_client bsd_nortos_test
+bsd_nortos_s390: shm_port_bridge bsd_client bsd_udp bsd_nortos_test
 	$(RUN) sh -c './shm_port_bridge & pid=$$!; sleep 1; ./bsd_nortos_test; rc=$$?; kill $$pid >/dev/null 2>&1; wait $$pid >/dev/null 2>&1; exit $$rc'
 
 shm_port_bridge: shm_port_bridge.c shm_queue.h
 	$(CC) shm_port_bridge.c $(CFLAGS) -pthread -o $@
 
 clean:                    # Cleanup. Delete built program and all build artifacts
-	rm -rf bsd_test bsd_client shm_port_bridge *.o *.obj FreeRTOS-Kernel
+	rm -rf bsd_test bsd_client bsd_udp shm_port_bridge *.o *.obj FreeRTOS-Kernel
 
 FreeRTOS-Kernel:  # FreeRTOS sources
 	git clone -q -c advice.detachedHead=false --depth 1 -b V11.2.0 https://github.com/FreeRTOS/FreeRTOS-Kernel $@

test/bsd/bsd_udp.c

@@ -0,0 +1,55 @@
+#include <arpa/inet.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+#include <unistd.h>
+
+#define PORT 1235
+
+int main(int argc, char *argv[]) {
+  struct sockaddr_in sa;
+  struct timeval timeout;
+  char buf[8];
+  ssize_t n;
+  int fd, rogue;
+
+  if (argc != 2) return 1;
+  memset(&sa, 0, sizeof(sa));
+  sa.sin_family = AF_INET;
+  sa.sin_port = htons(PORT);
+  if (inet_pton(AF_INET, argv[1], &sa.sin_addr) != 1) return 1;
+  timeout.tv_sec = 5, timeout.tv_usec = 0;
+  if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0 ||
+      setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, &timeout, sizeof(timeout)) != 0 ||
+      connect(fd, (struct sockaddr *) &sa, sizeof(sa)) != 0 ||
+      send(fd, "hello", 5, 0) != 5 || recv(fd, buf, sizeof(buf), 0) != 5 ||
+      memcmp(buf, "ready", 5) != 0)
+    goto fail;
+  if ((rogue = socket(AF_INET, SOCK_DGRAM, 0)) < 0 ||
+      setsockopt(rogue, SOL_SOCKET, SO_RCVTIMEO, &timeout, sizeof(timeout)) !=
+          0 ||
+      send(fd, "one", 3, 0) != 3 ||
+      sendto(rogue, "two2", 4, 0, (struct sockaddr *) &sa, sizeof(sa)) != 4 ||
+      recv(fd, buf, sizeof(buf), 0) != 4 || memcmp(buf, "peer", 4) != 0 ||
+      recv(rogue, buf, sizeof(buf), 0) != 5 || memcmp(buf, "rogue", 5) != 0 ||
+      send(fd, "truncate", 8, 0) != 8 || send(fd, "peek", 4, 0) != 4 ||
+      recv(fd, buf, sizeof(buf), 0) != 4 || memcmp(buf, "more", 4) != 0 ||
+      recv(fd, buf, sizeof(buf), 0) != 3 || memcmp(buf, "one", 3) != 0 ||
+      recv(fd, buf, sizeof(buf), 0) != 4 || memcmp(buf, "two2", 4) != 0 ||
+      recv(fd, buf, sizeof(buf), 0) != 0 ||
+      sendto(rogue, "rogue", 5, 0, (struct sockaddr *) &sa, sizeof(sa)) != 5 ||
+      recv(fd, buf, sizeof(buf), 0) != 7 || memcmp(buf, "checked", 7) != 0 ||
+      send(fd, "echo", 4, 0) != 4 || recv(fd, buf, sizeof(buf), 0) != 4 ||
+      memcmp(buf, "echo", 4) != 0)
+    goto fail_close_rogue;
+  close(rogue);
+  close(fd);
+  return 0;
+
+fail_close_rogue:
+  close(rogue);
+fail:
+  close(fd);
+  return 1;
+}

test/bsd/bsd_x_test.c

@@ -33,6 +33,175 @@ static int s_abort = 0;
 #define DASHBOARD(x) \
   printf("HEALTH_DASHBOARD\t\"%s\": %s,\n", x, s_error ? "false" : "true")
 
+#define UDP_PORT 1235
+
+#if MG_ENABLE_FREERTOS
+static volatile bool s_tx_held, s_tx_waits;
+#endif
+
+static int open_udp(void) {
+  struct sockaddr_in sa;
+  char buf;
+  int fd;
+
+  memset(&sa, 0, sizeof(sa));
+  sa.sin_family = AF_INET;
+  sa.sin_port = htons(UDP_PORT);
+  sa.sin_addr.s_addr = INADDR_ANY;
+  ASSERT((fd = socket(AF_INET, SOCK_DGRAM, 0)) >= 0);
+  ASSERT(bind(fd, (struct sockaddr *) &sa, sizeof(sa)) == 0);
+  ASSERT(send(fd, &buf, sizeof(buf), 0) < 0 && errno == EDESTADDRREQ);
+  ASSERT(fcntl(fd, F_SETFL, O_NONBLOCK) == 0);
+  return fd;
+}
+
+static void check_udp_oversize(struct mg_mgr *mgr, int fd,
+                               const struct sockaddr *dst, socklen_t dstlen) {
+  static char buf[1600];
+  size_t len = mgr->ifp->mtu + 1;
+
+  ASSERT(len <= sizeof(buf));
+  if (dst == NULL) {
+    ASSERT(send(fd, buf, len, 0) < 0 && errno == EMSGSIZE);
+  } else {
+    ASSERT(sendto(fd, buf, len, 0, dst, dstlen) < 0 && errno == EMSGSIZE);
+  }
+}
+
+static void udp_exchange(struct mg_mgr *mgr, int fd,
+                         void (*progress)(struct mg_mgr *)) {
+  struct sockaddr_in peer, other, rogue = {0};
+  socklen_t peerlen, otherlen;
+  uint64_t deadline;
+  struct timeval zero = {0, 0};
+  struct pollfd p;
+  fd_set r, w, e;
+  bool one;
+  char buf[8];
+  ssize_t n;
+
+  for (;;) {
+    peerlen = sizeof(peer);
+    n = recvfrom(fd, buf, sizeof(buf), 0, (struct sockaddr *) &peer, &peerlen);
+    if (n >= 0) break;
+    ASSERT(errno == EAGAIN);
+    progress(mgr);
+  }
+  ASSERT(n == 5 && memcmp(buf, "hello", 5) == 0);
+  ASSERT(sendto(fd, "ready", 5, 0, (struct sockaddr *) &peer, peerlen) ==
+         5);
+  deadline = mg_millis() + 100;
+  while (mg_millis() < deadline) progress(mgr);  // Queue both UDP datagrams
+  do {
+    otherlen = sizeof(other);
+    n = recvfrom(fd, buf, sizeof(buf), 0, (struct sockaddr *) &other,
+                 &otherlen);
+    if (n < 0) {
+      ASSERT(errno == EAGAIN);
+      progress(mgr);
+    }
+  } while (n < 0);
+  one = n == 3;
+  if (one) {
+    ASSERT(memcmp(buf, "one", 3) == 0 && other.sin_port == peer.sin_port);
+  } else {
+    ASSERT(n == 4 && memcmp(buf, "two2", 4) == 0 &&
+           other.sin_port != peer.sin_port);
+  }
+  if (other.sin_port != peer.sin_port) rogue = other;
+  do {
+    otherlen = sizeof(other);
+    n = recvfrom(fd, buf, sizeof(buf), 0, (struct sockaddr *) &other,
+                 &otherlen);
+    if (n < 0) {
+      ASSERT(errno == EAGAIN);
+      progress(mgr);
+    }
+  } while (n < 0);
+  if (one) {
+    ASSERT(n == 4 && memcmp(buf, "two2", 4) == 0 &&
+           other.sin_port != peer.sin_port);
+  } else {
+    ASSERT(n == 3 && memcmp(buf, "one", 3) == 0 &&
+           other.sin_port == peer.sin_port);
+  }
+  if (other.sin_port != peer.sin_port) rogue = other;
+  check_udp_oversize(mgr, fd, (struct sockaddr *) &peer, peerlen);
+  ASSERT(sendto(fd, "peer", 4, 0, (struct sockaddr *) &peer, peerlen) == 4);
+  ASSERT(sendto(fd, "rogue", 5, 0, (struct sockaddr *) &rogue,
+                sizeof(rogue)) == 5);
+  deadline = mg_millis() + 100;
+  while (mg_millis() < deadline) progress(mgr);
+  ASSERT(connect(fd, (struct sockaddr *) &peer, peerlen) == 0);
+  ASSERT(sendto(fd, "no", 2, 0, (struct sockaddr *) &peer, peerlen) < 0 &&
+         errno == EISCONN);
+  check_udp_oversize(mgr, fd, NULL, 0);
+  ASSERT(send(fd, "more", 4, 0) == 4);
+  deadline = mg_millis() + 100;
+  while (mg_millis() < deadline) progress(mgr);  // Queue both UDP datagrams
+  do {
+    p.fd = fd, p.events = POLLIN | POLLOUT, p.revents = 0;
+    ASSERT(poll(&p, 1, 0) == 1);
+    if (!(p.revents & POLLIN)) progress(mgr);
+  } while (!(p.revents & POLLIN));
+  ASSERT(p.revents == (POLLIN | POLLOUT));
+  FD_ZERO(&r);
+  FD_ZERO(&w);
+  FD_ZERO(&e);
+  FD_SET(fd, &r);
+  FD_SET(fd, &w);
+  FD_SET(fd, &e);
+  ASSERT(select(fd + 1, &r, &w, &e, &zero) == 1);
+  ASSERT(FD_ISSET(fd, &r) && FD_ISSET(fd, &w) && !FD_ISSET(fd, &e));
+  do {
+    n = recv(fd, buf, 3, 0);
+    if (n < 0) {
+      ASSERT(errno == EAGAIN);
+      progress(mgr);
+    }
+  } while (n < 0);
+  ASSERT(n == 3 && memcmp(buf, "tru", 3) == 0);
+  do {
+    n = recv(fd, buf, sizeof(buf), MSG_PEEK);
+    if (n < 0) {
+      ASSERT(errno == EAGAIN);
+      progress(mgr);
+    }
+  } while (n < 0);
+  ASSERT(n == 4 && memcmp(buf, "peek", 4) == 0);
+  ASSERT(recv(fd, buf, sizeof(buf), 0) == 4 && memcmp(buf, "peek", 4) == 0);
+  p.events = POLLIN | POLLOUT, p.revents = 0;
+  ASSERT(poll(&p, 1, 0) == 1 && p.revents == POLLOUT);
+#if MG_ENABLE_FREERTOS
+  s_tx_waits = false, s_tx_held = true;
+#endif
+  ASSERT(send(fd, "one", 3, 0) == 3);
+  ASSERT(send(fd, "two2", 4, 0) == 4);
+  ASSERT(send(fd, "", 0, 0) == 0);
+#if MG_ENABLE_FREERTOS
+  while (!s_tx_waits) progress(mgr);  // MG_IO_WAIT keeps all records queued
+  s_tx_held = false;
+#endif
+  deadline = mg_millis() + 100;
+  while (mg_millis() < deadline) progress(mgr);  // Let rogue arrive
+  ASSERT(recv(fd, buf, sizeof(buf), MSG_DONTWAIT) < 0 && errno == EAGAIN);
+  while ((n = send(fd, "checked", 7, 0)) < 0) {
+    ASSERT(errno == EAGAIN);
+    progress(mgr);
+  }
+  ASSERT(n == 7);
+  for (;;) {
+    n = recv(fd, buf, sizeof(buf), 0);
+    if (n >= 0) break;
+    ASSERT(errno == EAGAIN);
+    progress(mgr);
+  }
+  ASSERT(n == 4 && memcmp(buf, "echo", 4) == 0);
+  ASSERT(send(fd, "echo", 4, 0) == 4);
+  progress(mgr);  // Drain the last queued datagram before close
+  ASSERT(close(fd) == 0);
+}
+
 static pid_t start_client(const char *ip, const char *connections) {
   char *cmd[4];
   pid_t pid;
@@ -46,6 +215,18 @@ static pid_t start_client(const char *ip, const char *connections) {
   return pid;
 }
 
+static pid_t start_udp(const char *ip) {
+  char *cmd[3];
+  pid_t pid;
+  extern char **environ;
+
+  cmd[0] = (char *) "./bsd_udp";
+  cmd[1] = (char *) ip;
+  cmd[2] = NULL;
+  ASSERT(posix_spawn(&pid, cmd[0], NULL, NULL, cmd, environ) == 0);
+  return pid;
+}
+
 static bool client_done(pid_t pid, int *status) {
   pid_t r = waitpid(pid, status, WNOHANG);
   ASSERT(r >= 0);
@@ -60,12 +241,17 @@ static void check_client(int status) {
 static int open_listener(int backlog, bool nonblock) {
   int lfd = socket(AF_INET, SOCK_STREAM, 0);
   struct sockaddr_in sa;
+  char buf;
 
   memset(&sa, 0, sizeof(sa));
   sa.sin_family = AF_INET;
   sa.sin_port = htons(1234);
   sa.sin_addr.s_addr = INADDR_ANY;
   ASSERT(lfd >= 0);
+  ASSERT(sendto(lfd, &buf, sizeof(buf), 0, (struct sockaddr *) &sa,
+                sizeof(sa)) < 0 && errno == EOPNOTSUPP);
+  ASSERT(recvfrom(lfd, &buf, sizeof(buf), 0, NULL, NULL) < 0 &&
+         errno == EOPNOTSUPP);
   ASSERT(bind(lfd, (struct sockaddr *) &sa, sizeof(sa)) == 0);
   ASSERT(listen(lfd, backlog) == 0);
   if (nonblock) ASSERT(fcntl(lfd, F_SETFL, O_NONBLOCK) == 0);
@@ -130,11 +316,12 @@ static volatile bool s_select_waiting, s_select_done;
 static volatile bool s_poll_waiting, s_poll_done;
 static volatile bool s_ready_waiting, s_ready_done;
 static volatile bool s_backlog_ready, s_backlog_full, s_backlog_accept;
-static volatile bool s_tx_held, s_tx_waits, s_tx_fail, s_tx_error;
+static volatile bool s_tx_fail, s_tx_error;
 static volatile bool s_send_waiting;
 static volatile bool s_send_done, s_send_expect_error;
 static volatile bool s_recv_start, s_recv_waiting, s_recv_done;
 static volatile bool s_recv_expect_error;
+static volatile bool s_udp_ready, s_udp_done;
 static size_t (*s_tx)(const void *, size_t, struct mg_tcpip_if *);
 
 struct client_data {
@@ -152,6 +339,7 @@ static void select_task(void *args);
 static void readiness_task(void *args);
 static void backlog_task(void *args);
 static void tx_gate_task(void *args);
+static void udp_task(void *args);
 
 struct atask_args {
   bool listener_nonblock;
@@ -306,6 +494,21 @@ static void tx_gate_task(void *args) {
   (void) args;
 }
 
+static void udp_delay(struct mg_mgr *mgr) {
+  (void) mgr;
+  vTaskDelay(1);
+}
+
+static void udp_task(void *args) {
+  struct mg_mgr *mgr = (struct mg_mgr *) args;
+  int fd = open_udp();
+
+  s_udp_ready = true;
+  udp_exchange(mgr, fd, udp_delay);
+  s_udp_done = true;
+  vTaskDelete(NULL);
+}
+
 static void recv_wait_task(void *args) {
   char buf;
   int fd = (int) (uintptr_t) args;
@@ -519,12 +722,22 @@ static void task2(void *args) {
   struct mg_mgr *mgr = (struct mg_mgr *)args;  // Event manager
   char *ip;
   int status;
-  pid_t first, second;
+  pid_t first, second, udp;
 
   vTaskDelay(pdMS_TO_TICKS(500));  // 500 ms
   s_error = false;
   s_wait = false;
   ip = mg_mprintf("%M", mg_print_ip4, &mgr->ifp->ip);
+  s_udp_ready = s_udp_done = false;
+  ASSERT(xTaskCreate(udp_task, "udp", 512, mgr, configMAX_PRIORITIES - 1,
+                     NULL) == pdPASS);
+  while (!s_udp_ready) vTaskDelay(1);
+  udp = start_udp(ip);
+  while (!client_done(udp, &status)) vTaskDelay(1);
+  check_client(status);
+  while (!s_udp_done) vTaskDelay(1);
+  DASHBOARD("udp");
+
   s_poll_waiting = s_poll_done = false;
   ASSERT(xTaskCreate(poll_task, "poll", 512, NULL,
                      configMAX_PRIORITIES - 1, NULL) == pdPASS);
@@ -555,7 +768,6 @@ static void task2(void *args) {
   DASHBOARD("select_child_write");
   DASHBOARD("poll_child_write");
 
-  #if 0
   s_error = false;
   s_backlog_ready = s_backlog_full = s_backlog_accept = false;
   ASSERT(xTaskCreate(backlog_task, "backlog", 512, NULL,
@@ -570,12 +782,6 @@ static void task2(void *args) {
   while (!client_done(first, &status)) vTaskDelay(1);
   check_client(status);
   DASHBOARD("listen_backlog");
-#else
-    (void) first;
-    (void) second;
-    (void) status;
-    (void) backlog_task;
-#endif
 
   s_error = false;
   // atask at higher priority than task1
@@ -859,6 +1065,20 @@ static void nortos_echo(struct mg_mgr *mgr, struct nortos_echo_client *clients,
   nortos_wait_client(mgr, pid);
 }
 
+static void udp_poll(struct mg_mgr *mgr) {
+  mg_mgr_poll(mgr, 0);
+}
+
+static void nortos_udp(struct mg_mgr *mgr, const char *ip) {
+  pid_t pid;
+  int fd = open_udp();
+
+  pid = start_udp(ip);
+  udp_exchange(mgr, fd, udp_poll);
+  nortos_wait_client(mgr, pid);
+  DASHBOARD("nortos_udp");
+}
+
 static void nortos_test(struct mg_mgr *mgr) {
   static const char bootstrap = '\0';
   static const char grow[512] = {0};
@@ -960,6 +1180,7 @@ static void nortos_test(struct mg_mgr *mgr) {
   ASSERT(close(fd) == 0);
   mg_mgr_poll(mgr, 0);
   DASHBOARD("nortos_nonblocking_connect");
+  nortos_udp(mgr, ip);
   mg_free(ip);
 }
 

test/unit_test.c

@@ -3158,8 +3158,6 @@ static bool su_cb(struct mg_http_message *hm, struct mg_str *data, void **p) {
 static void su(struct mg_connection *c, int ev, void *ev_data) {
   if (ev == MG_EV_HTTP_HDRS) {
     mg_http_stream_body(c, (struct mg_http_message *) ev_data, su_cb, NULL);
-  } else if (ev == MG_EV_HTTP_MSG) {  // Only for requests that were not streamed
-    mg_http_reply(c, 400, "", "not streamed\n");
   }
 }
 
@@ -3194,8 +3192,7 @@ static void cr(struct mg_connection *c, int ev, void *ev_data) {
   if (ev == MG_EV_CONNECT) {
     mg_printf(c, "GET / HTTP/1.0\r\n\r\n");
   } else if (ev == MG_EV_HTTP_HDRS) {
-    ASSERT(mg_http_stream_body(c, (struct mg_http_message *) ev_data, cr_cb,
-                               NULL));
+    mg_http_stream_body(c, (struct mg_http_message *) ev_data, cr_cb, NULL);
   }
 }
 
@@ -3208,12 +3205,103 @@ static void cs(struct mg_connection *c, int ev, void *ev_data) {
   (void) ev_data;
 }
 
+struct stream_test_state {
+  int fail_at, starts, chunks, ends;
+};
+
+static bool stream_test_cb(struct mg_http_message *hm, struct mg_str *data,
+                            void **p) {
+  struct stream_test_state *s = (struct stream_test_state *) *p;
+  ASSERT(s != NULL);
+  if (hm != NULL) {
+    s->starts++;
+    return s->fail_at != 1;
+  } else if (data != NULL) {
+    s->chunks++;
+    return s->fail_at != 2;
+  }
+  s->ends++;
+  *p = NULL;
+  return s->fail_at != 3;
+}
+
+static void stream_test_original(struct mg_connection *c, int ev, void *data) {
+  (void) c, (void) ev, (void) data;
+  ASSERT(false);  // Streaming must take ownership even when validation fails
+}
+
+static void test_http_stream_errors(void) {
+  static const struct {
+    const char *request;
+    int client, fail_at, body_size, code, starts, chunks;
+  } cases[] = {
+      {"GET / HTTP/1.1\r\nContent-Length: 0\r\n\r\n", 0, 0, 0, 405, 0, 0},
+      {"POST / HTTP/1.1\r\n\r\n", 0, 0, 0, 411, 0, 0},
+      {"POST / HTTP/1.1\r\nTransfer-Encoding: chunked\r\n\r\n",
+       0, 0, 0, 400, 0, 0},
+      {"POST / HTTP/1.1\r\nContent-Length: 3\r\n\r\nabc", 0, 0, 0, 200, 1, 1},
+      {"PUT / HTTP/1.1\r\nContent-Length: 0\r\n\r\n", 0, 0, 0, 200, 1, 0},
+      // Start failure must reply without waiting for the body or sending 100.
+      {"POST / HTTP/1.1\r\nContent-Length: 1000000\r\nExpect: 100-continue\r\n\r\n",
+       0, 1, 0, 500, 1, 0},
+      // Write failure must also reply before the announced body is complete.
+      {"POST / HTTP/1.1\r\nContent-Length: 1000000\r\n\r\n",
+       0, 2, 512, 500, 1, 1},
+      {"POST / HTTP/1.1\r\nContent-Length: 3\r\n\r\nabc", 0, 3, 0, 500, 1, 1},
+      // Clients close on errors and never send an HTTP error response.
+      {"HTTP/1.1 200 OK\r\n\r\n", 1, 0, 0, 411, 0, 0},
+      {"HTTP/1.1 200 OK\r\nTransfer-Encoding: chunked\r\n\r\n",
+       1, 0, 0, 400, 0, 0},
+      {"HTTP/1.1 200 OK\r\nContent-Length: 1000000\r\n\r\n",
+       1, 1, 0, 500, 1, 0},
+      {"HTTP/1.1 200 OK\r\nContent-Length: 1000000\r\n\r\n",
+       1, 2, 512, 500, 1, 1},
+      {"HTTP/1.1 200 OK\r\nContent-Length: 3\r\n\r\nabc", 1, 3, 0, 500, 1, 1},
+      {"HTTP/1.1 200 OK\r\nContent-Length: 3\r\n\r\nabc", 1, 0, 0, 200, 1, 1},
+      {"HTTP/1.1 204 No Content\r\n\r\n", 1, 0, 0, 200, 1, 0},
+  };
+  size_t i;
+  for (i = 0; i < sizeof(cases) / sizeof(cases[0]); i++) {
+    struct mg_connection c;
+    struct mg_http_message hm;
+    struct stream_test_state state = {0, 0, 0, 0};
+    char body[512];
+    memset(&c, 0, sizeof(c));
+    memset(body, 'x', sizeof(body));
+    state.fail_at = cases[i].fail_at;
+    c.is_client = cases[i].client != 0;
+    c.fn = c.pfn = stream_test_original;
+    mg_iobuf_add(&c.recv, 0, cases[i].request, strlen(cases[i].request));
+    mg_iobuf_add(&c.recv, c.recv.len, body, (size_t) cases[i].body_size);
+    ASSERT(mg_http_parse((char *) c.recv.buf, c.recv.len, &hm) > 0);
+    mg_http_stream_body(&c, &hm, stream_test_cb, &state);
+    ASSERT(c.pfn == NULL && c.is_draining);
+    ASSERT(state.starts == cases[i].starts && state.chunks == cases[i].chunks);
+    ASSERT(state.ends == 1);
+    if (c.is_client) {
+      ASSERT(c.send.len == 0);
+      ASSERT(c.is_closing == (cases[i].code != 200));
+    } else {
+      ASSERT(mg_http_parse((char *) c.send.buf, c.send.len, &hm) > 0);
+      ASSERT(mg_http_status(&hm) == cases[i].code);
+      ASSERT(hm.message.len == c.send.len);  // Exactly one response
+    }
+    mg_call(&c, MG_EV_READ, NULL);
+    mg_error(&c, "stream cleanup test");
+    mg_call(&c, MG_EV_CLOSE, NULL);
+    ASSERT(state.ends == 1);  // Error followed by close must not clean up twice
+    mg_iobuf_free(&c.recv);
+    mg_iobuf_free(&c.send);
+  }
+}
+
 static void test_http_upload(void) {
   struct mg_mgr mgr;
   const char *url = "http://127.0.0.1:12352";
   int i;
   const char *s = "ok (8 foo\nbar\n)\n";
 
+  test_http_stream_errors();
   mg_mgr_init(&mgr);
   mg_http_listen(&mgr, url, us, NULL);
   mg_http_connect(&mgr, url, uc, (void *) &s);
@@ -3257,7 +3345,7 @@ static void test_http_upload(void) {
     ASSERT(mgr.conns == NULL);
   }
 
-  // mg_http_stream_body: chunked request is not streamed, caller replies "400"
+  // mg_http_stream_body: chunked request rejected with "400", cleanup still runs
   {
     char buf[FETCH_BUF_SIZE];
     s_su_done = s_su_end = 0;
@@ -3268,7 +3356,7 @@ static void test_http_upload(void) {
                  "POST /su_chunked.txt HTTP/1.1\r\n"
                  "Transfer-Encoding: chunked\r\n\r\n"
                  "3\r\nfoo\r\n0\r\n\r\n") == 400);
-    ASSERT(s_su_done == 0 && s_su_end == 0);  // The callback was never called
+    ASSERT(s_su_done == 1 && s_su_end == 1);  // End called without start
     ASSERT(fopen("su_chunked.txt", "r") == NULL);
     mg_mgr_free(&mgr);
     ASSERT(mgr.conns == NULL);
@@ -5010,6 +5098,20 @@ static void test_dash(void) {
                "Authorization: Basic YWRtaW46YWRtaW4=\n\n") == 200);
   ASSERT(cmpbody(buf, login_admin_expected) == 0);
 
+  // OTA uses streaming and enforces the dashboard's authentication.
+  ASSERT(fetch(&mgr, buf, url,
+               "POST /api/ota HTTP/1.0\nContent-Length: 1\n\nx") == 403);
+  ASSERT(fetch(&mgr, buf, url,
+               "GET /api/ota HTTP/1.0\nContent-Length: 0\n"
+               "Authorization: Basic YWRtaW46YWRtaW4=\n\n") == 405);
+  ASSERT(fetch(&mgr, buf, url,
+               "POST /ota HTTP/1.0\nContent-Length: 1\n"
+               "Authorization: Basic YWRtaW46YWRtaW4=\n\nx") == 404);
+  ASSERT(fetch(&mgr, buf, url,
+               "POST /api/ota HTTP/1.0\nContent-Length: 1\n"
+               "Authorization: Basic YWRtaW46YWRtaW4=\n\nx") == 200);
+  ASSERT(cmpbody(buf, "1 ok\n") == 0);
+
   // set3 is admin-only
   ASSERT(fetch(&mgr, buf, url,
                "GET /api/get/set3 HTTP/1.0\n"

tutorials/esp32/minimal/Makefile

@@ -1,9 +1,11 @@
 THISDIR = $(realpath $(CURDIR))
 ROOTDIR = $(realpath $(CURDIR)/../../..)
 DOCKER ?= docker run --rm $(DA) -v $(ROOTDIR):$(ROOTDIR) -w $(THISDIR) espressif/idf
-CMD ?= idf.py build
+CMD ?= idf.py -DCFLAGS_EXTRA="$(CFLAGS_EXTRA)" build
 PORT ?= /dev/ttyUSB0
 
+CFLAGS_EXTRA ?= -DMG_TLS=MG_TLS_BUILTIN
+
 all: example
 
 example:

tutorials/esp32/minimal/main/CMakeLists.txt

@@ -12,3 +12,5 @@ idf_component_register(SRCS "main.c"
                                 espcoredump
                                 nvs_flash
                                 app_update)
+separate_arguments(CFLAGS_EXTRA)
+component_compile_options(${CFLAGS_EXTRA})

tutorials/esp32/minimal/main/main.c

@@ -44,6 +44,11 @@ static void http_ev_handler(struct mg_connection *c, int ev, void *ev_data) {
     struct mg_tls_opts opts = {.cert = mg_str(TLS_CERT),
                                .key = mg_str(TLS_KEY)};
     mg_tls_init(c, &opts);
+  } else if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
   } else if (ev == MG_EV_HTTP_MSG) {
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     size_t total = heap_caps_get_total_size(MALLOC_CAP_DEFAULT);
@@ -65,10 +70,8 @@ static void http_ev_handler(struct mg_connection *c, int ev, void *ev_data) {
   }
 }
 
-extern void wifi_init(const char *ssid, const char *pass);
-
 void app_main(void) {
-  MG_HEALTH_INIT();
+  void wifi_init(const char *ssid, const char *pass);
   wifi_init(WIFI_SSID, WIFI_PASS);
 
   struct mg_mgr mgr;

tutorials/esp32/minimal/main/mongoose_config.h

@@ -1,6 +1 @@
 #define MG_ARCH MG_ARCH_ESP32
-
-#define MG_ENABLE_HEALTH 1
-
-#define MG_TLS MG_TLS_BUILTIN
-//#define MG_TLS MG_TLS_MBED

tutorials/micropython/esp32/mongoose/main.c

@@ -9,7 +9,12 @@ static void t_fn(void *arg) {  // Tick periodically
 }
 
 static void fn(struct mg_connection *c, int ev, void *ev_data) {
-  if (ev == MG_EV_HTTP_MSG) mg_http_reply(c, 200, "", "hi\n");
+  if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
+  } else if (ev == MG_EV_HTTP_MSG) mg_http_reply(c, 200, "", "hi\n");
   (void) ev_data;
 }
 

tutorials/micropython/mongoose/main.c

@@ -9,7 +9,12 @@ static void t_fn(void *arg) {  // Tick periodically
 }
 
 static void fn(struct mg_connection *c, int ev, void *ev_data) {
-  if (ev == MG_EV_HTTP_MSG) mg_http_reply(c, 200, "", "hi\n");
+  if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
+  } else if (ev == MG_EV_HTTP_MSG) mg_http_reply(c, 200, "", "hi\n");
   (void) ev_data;
 }
 

tutorials/micropython/mongoose/module.c

@@ -3,24 +3,24 @@
 extern void mgmp_init(void);
 extern void mgmp_poll(int);
 
-STATIC mp_obj_t mongoose_init(void) {
+static mp_obj_t mongoose_init(void) {
     mgmp_init();
     return mp_const_none;
 }
-STATIC MP_DEFINE_CONST_FUN_OBJ_0(mongoose_init_obj, mongoose_init);
+static MP_DEFINE_CONST_FUN_OBJ_0(mongoose_init_obj, mongoose_init);
 
-STATIC mp_obj_t mongoose_poll(mp_obj_t t_obj) {
+static mp_obj_t mongoose_poll(mp_obj_t t_obj) {
     mgmp_poll(mp_obj_get_int(t_obj));
     return mp_const_none;
 }
-STATIC MP_DEFINE_CONST_FUN_OBJ_1(mongoose_poll_obj, mongoose_poll);
+static MP_DEFINE_CONST_FUN_OBJ_1(mongoose_poll_obj, mongoose_poll);
 
-STATIC const mp_rom_map_elem_t mongoose_module_globals_table[] = {
+static const mp_rom_map_elem_t mongoose_module_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_mongoose) },
     { MP_ROM_QSTR(MP_QSTR_init), MP_ROM_PTR(&mongoose_init_obj) },
     { MP_ROM_QSTR(MP_QSTR_poll), MP_ROM_PTR(&mongoose_poll_obj) },
 };
-STATIC MP_DEFINE_CONST_DICT(mongoose_module_globals, mongoose_module_globals_table);
+static MP_DEFINE_CONST_DICT(mongoose_module_globals, mongoose_module_globals_table);
 
 const mp_obj_module_t mongoose_module = {
     .base = { &mp_type_module },

tutorials/mqtt/mqtt-client/mongoose_mqtt.c

@@ -120,7 +120,7 @@ void mg_mqtt_poll(struct mg_mgr *mgr) {
 
   // Reconnect if connection is closed, and send MQTT PINGs to keep
   // the connection alive or to detect connection loss
-  if (mg_timer_expired(&timer, MQTT_RECONNECT_PERIOD_MS, mg_now())) {
+  if (mg_timer_expired(&timer, MQTT_RECONNECT_PERIOD_MS, mg_millis())) {
     if (s_mqtt_conn == NULL) {
       struct mg_mqtt_opts opts = {
           .clean = true,

tutorials/nxp/frdm-imxrt1186/minimal/main.c

@@ -65,6 +65,11 @@ static void http_ev_handler(struct mg_connection *c, int ev, void *ev_data) {
     struct mg_tls_opts opts = {.cert = mg_str(TLS_CERT),
                                .key = mg_str(TLS_KEY)};
     mg_tls_init(c, &opts);
+  } else if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
   } else if (ev == MG_EV_HTTP_MSG) {  // New HTTP request received
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     if (mg_match(hm->uri, mg_str("/api/tick"), NULL)) {

tutorials/nxp/frdm-mcxe247/minimal/main.c

@@ -89,6 +89,11 @@ static void http_ev_handler(struct mg_connection *c, int ev, void *ev_data) {
     struct mg_tls_opts opts = {.cert = mg_str(TLS_CERT),
                                .key = mg_str(TLS_KEY)};
     mg_tls_init(c, &opts);
+  } else if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
   } else if (ev == MG_EV_HTTP_MSG) {  // New HTTP request received
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     if (mg_match(hm->uri, mg_str("/api/tick"), NULL)) {

tutorials/nxp/frdm-mcxn947/minimal/main.c

@@ -97,6 +97,11 @@ static void http_ev_handler(struct mg_connection *c, int ev, void *ev_data) {
     struct mg_tls_opts opts = {.cert = mg_str(TLS_CERT),
                                .key = mg_str(TLS_KEY)};
     mg_tls_init(c, &opts);
+  } else if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
   } else if (ev == MG_EV_HTTP_MSG) {  // New HTTP request received
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     if (mg_match(hm->uri, mg_str("/api/tick"), NULL)) {

tutorials/nxp/frdm-mcxw71/minimal/main.c

@@ -47,6 +47,11 @@ static void http_ev_handler(struct mg_connection *c, int ev, void *ev_data) {
     struct mg_tls_opts opts = {.cert = mg_str(TLS_CERT),
                                .key = mg_str(TLS_KEY)};
     mg_tls_init(c, &opts);
+  } else if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
   } else if (ev == MG_EV_HTTP_MSG) {
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     if (mg_match(hm->uri, mg_str("/api/tick"), NULL)) {

tutorials/nxp/frdm-rw612/minimal/main.c

@@ -65,6 +65,11 @@ static void http_ev_handler(struct mg_connection *c, int ev, void *ev_data) {
     struct mg_tls_opts opts = {.cert = mg_str(TLS_CERT),
                                .key = mg_str(TLS_KEY)};
     mg_tls_init(c, &opts);
+  } else if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
   } else if (ev == MG_EV_HTTP_MSG) {  // New HTTP request received
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     if (mg_match(hm->uri, mg_str("/api/tick"), NULL)) {

tutorials/nxp/rt1060-evkb/minimal/main.c

@@ -61,6 +61,11 @@ static void http_ev_handler(struct mg_connection *c, int ev, void *ev_data) {
     struct mg_tls_opts opts = {.cert = mg_str(TLS_CERT),
                                .key = mg_str(TLS_KEY)};
     mg_tls_init(c, &opts);
+  } else if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
   } else if (ev == MG_EV_HTTP_MSG) {  // New HTTP request received
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     if (mg_match(hm->uri, mg_str("/api/tick"), NULL)) {

tutorials/nxp/rt1170-evkb/minimal/main.c

@@ -65,6 +65,11 @@ static void http_ev_handler(struct mg_connection *c, int ev, void *ev_data) {
     struct mg_tls_opts opts = {.cert = mg_str(TLS_CERT),
                                .key = mg_str(TLS_KEY)};
     mg_tls_init(c, &opts);
+  } else if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
   } else if (ev == MG_EV_HTTP_MSG) {  // New HTTP request received
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     if (mg_match(hm->uri, mg_str("/api/tick"), NULL)) {

tutorials/rp/pico-rm2/main.c

@@ -5,7 +5,12 @@
 #include "mongoose.h"
 
 static void http_ev_handler(struct mg_connection *c, int ev, void *ev_data) {
-  if (ev == MG_EV_HTTP_MSG) {  // New HTTP request received
+  if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
+  } else if (ev == MG_EV_HTTP_MSG) {  // New HTTP request received
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     uint64_t tick = to_ms_since_boot(get_absolute_time());
     if (mg_match(hm->uri, mg_str("/api/tick"), NULL)) {

tutorials/rp/pico-rmii/main.c

@@ -33,7 +33,12 @@ static void driver_init(struct mg_mgr *mgr) {
 }
 
 static void http_ev_handler(struct mg_connection *c, int ev, void *ev_data) {
-  if (ev == MG_EV_HTTP_MSG) {  // New HTTP request received
+  if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
+  } else if (ev == MG_EV_HTTP_MSG) {  // New HTTP request received
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     uint64_t tick = to_ms_since_boot(get_absolute_time());
     if (mg_match(hm->uri, mg_str("/api/tick"), NULL)) {

tutorials/rp/pico-rndis/main.c

@@ -58,7 +58,12 @@ static void driver_init(struct mg_mgr *mgr) {
 }
 
 static void http_ev_handler(struct mg_connection *c, int ev, void *ev_data) {
-  if (ev == MG_EV_HTTP_MSG) {  // New HTTP request received
+  if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
+  } else if (ev == MG_EV_HTTP_MSG) {  // New HTTP request received
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     uint64_t tick = to_ms_since_boot(get_absolute_time());
     if (mg_match(hm->uri, mg_str("/api/tick"), NULL)) {

tutorials/rp/pico-w/main.c

@@ -39,6 +39,11 @@ static void http_ev_handler(struct mg_connection *c, int ev, void *ev_data) {
     struct mg_tls_opts opts = {.cert = mg_str(TLS_CERT),
                                .key = mg_str(TLS_KEY)};
     mg_tls_init(c, &opts);
+  } else if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
   } else if (ev == MG_EV_HTTP_MSG) {  // New HTTP request received
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     uint64_t tick = to_ms_since_boot(get_absolute_time());

tutorials/rp/w5500-evb-pico/main.c

@@ -82,6 +82,11 @@ static void http_ev_handler(struct mg_connection *c, int ev, void *ev_data) {
     struct mg_tls_opts opts = {.cert = mg_str(TLS_CERT),
                                .key = mg_str(TLS_KEY)};
     mg_tls_init(c, &opts);
+  } else if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
   } else if (ev == MG_EV_HTTP_MSG) {  // New HTTP request received
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     uint64_t tick = to_ms_since_boot(get_absolute_time());

tutorials/rp/w55rp20-evb-pico/main.c

@@ -195,6 +195,11 @@ static void http_ev_handler(struct mg_connection *c, int ev, void *ev_data) {
     struct mg_tls_opts opts = {.cert = mg_str(TLS_CERT),
                                .key = mg_str(TLS_KEY)};
     mg_tls_init(c, &opts);
+  } else if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
   } else if (ev == MG_EV_HTTP_MSG) {  // New HTTP request received
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     uint64_t tick = to_ms_since_boot(get_absolute_time());

tutorials/stm32/nucleo-c5a3zg/minimal/main.c

@@ -63,6 +63,11 @@ static void http_ev_handler(struct mg_connection *c, int ev, void *ev_data) {
     struct mg_tls_opts opts = {.cert = mg_str(TLS_CERT),
                                .key = mg_str(TLS_KEY)};
     mg_tls_init(c, &opts);
+  } else if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
   } else if (ev == MG_EV_HTTP_MSG) {
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     if (mg_match(hm->uri, mg_str("/api/tick"), NULL)) {

tutorials/stm32/nucleo-f429zi/minimal-rndis/main.c

@@ -66,7 +66,12 @@ static bool usb_poll(struct mg_tcpip_if *ifp, bool s1) {
 }
 
 static void fn(struct mg_connection *c, int ev, void *ev_data) {
-  if (ev == MG_EV_HTTP_MSG) {
+  if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
+  } else if (ev == MG_EV_HTTP_MSG) {
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     if (mg_match(hm->uri, mg_str("/api/debug"), NULL)) {
       int level = mg_json_get_long(hm->body, "$.level", MG_LL_DEBUG);

tutorials/stm32/nucleo-f429zi/minimal/main.c

@@ -68,6 +68,11 @@ static void http_ev_handler(struct mg_connection *c, int ev, void *ev_data) {
     struct mg_tls_opts opts = {.cert = mg_str(TLS_CERT),
                                .key = mg_str(TLS_KEY)};
     mg_tls_init(c, &opts);
+  } else if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
   } else if (ev == MG_EV_HTTP_MSG) {  // New HTTP request received
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     if (mg_match(hm->uri, mg_str("/api/tick"), NULL)) {

tutorials/stm32/nucleo-f746zg/minimal-pppoe/main.c

@@ -28,7 +28,12 @@ bool mg_random(void *buf, size_t len) {  // Use on-board RNG
 
 
 static void fn(struct mg_connection *c, int ev, void *ev_data) {
-  if (ev == MG_EV_HTTP_MSG) {
+  if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
+  } else if (ev == MG_EV_HTTP_MSG) {
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     (void) hm;
     mg_http_reply(c, 200, "", "hi\n");

tutorials/stm32/nucleo-f746zg/minimal-rndis/main.c

@@ -66,7 +66,12 @@ static bool usb_poll(struct mg_tcpip_if *ifp, bool s1) {
 }
 
 static void fn(struct mg_connection *c, int ev, void *ev_data) {
-  if (ev == MG_EV_HTTP_MSG) {
+  if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
+  } else if (ev == MG_EV_HTTP_MSG) {
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     if (mg_match(hm->uri, mg_str("/api/debug"), NULL)) {
       int level = mg_json_get_long(hm->body, "$.level", MG_LL_DEBUG);

tutorials/stm32/nucleo-f746zg/minimal/main.c

@@ -68,6 +68,11 @@ static void http_ev_handler(struct mg_connection *c, int ev, void *ev_data) {
     struct mg_tls_opts opts = {.cert = mg_str(TLS_CERT),
                                .key = mg_str(TLS_KEY)};
     mg_tls_init(c, &opts);
+  } else if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
   } else if (ev == MG_EV_HTTP_MSG) {  // New HTTP request received
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     if (mg_match(hm->uri, mg_str("/api/tick"), NULL)) {

tutorials/stm32/nucleo-f756zg/minimal/main.c

@@ -68,6 +68,11 @@ static void http_ev_handler(struct mg_connection *c, int ev, void *ev_data) {
     struct mg_tls_opts opts = {.cert = mg_str(TLS_CERT),
                                .key = mg_str(TLS_KEY)};
     mg_tls_init(c, &opts);
+  } else if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
   } else if (ev == MG_EV_HTTP_MSG) {  // New HTTP request received
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     if (mg_match(hm->uri, mg_str("/api/tick"), NULL)) {

tutorials/stm32/nucleo-g031k8/minimal-w5500/main.c

@@ -47,7 +47,12 @@ static void timer_fn(void *arg) {
 
 static void fn(struct mg_connection *c, int ev, void *ev_data) {
   struct mg_tcpip_if *ifp = (struct mg_tcpip_if *) c->fn_data;
-  if (ev == MG_EV_HTTP_MSG) {
+  if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
+  } else if (ev == MG_EV_HTTP_MSG) {
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     if (mg_match(hm->uri, mg_str("/api/hello"),
                  NULL)) {  // Request to /api/hello

tutorials/stm32/nucleo-h563zi/minimal/main.c

@@ -68,6 +68,11 @@ static void http_ev_handler(struct mg_connection *c, int ev, void *ev_data) {
     struct mg_tls_opts opts = {.cert = mg_str(TLS_CERT),
                                .key = mg_str(TLS_KEY)};
     mg_tls_init(c, &opts);
+  } else if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
   } else if (ev == MG_EV_HTTP_MSG) {
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     if (mg_match(hm->uri, mg_str("/api/tick"), NULL)) {

tutorials/stm32/nucleo-h723zg/cubemx/Core/Src/main.c

@@ -89,7 +89,12 @@ static void log_fn(char ch, void *param) {
 }
 
 static void http_ev_handler(struct mg_connection *c, int ev, void *ev_data) {
- if (ev == MG_EV_HTTP_MSG) {
+  if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
+  } else if (ev == MG_EV_HTTP_MSG) {
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     if (mg_match(hm->uri, mg_str("/api/tick"), NULL)) {
       mg_http_reply(c, 200, "", "{%m:%lu}\n", MG_ESC("tick"), HAL_GetTick());

tutorials/stm32/nucleo-h723zg/minimal-bsd-baremetal/echo.c

@@ -6,7 +6,6 @@
 
 #include "mongoose.h"
 
-#include <stdio.h>
 #include <stdlib.h>
 
 struct echo_server {
@@ -43,12 +42,12 @@ int echo_init(uint16_t port) {
 
   if (fd < 0 || !echo_nonblock(fd) ||
       bind(fd, (struct sockaddr *) &sa, sizeof(sa)) < 0 || listen(fd, 3) < 0) {
-    printf("BSD echo init: %d\n", errno);
+    MG_ERROR(("BSD echo init: %d", errno));
     if (fd >= 0) close(fd);
     return 0;
   }
   s_server.sock = fd;
-  printf("BSD echo server on port %hu\n", port);
+  MG_INFO(("BSD echo server on port %hu", port));
   return 1;
 }
 
@@ -80,7 +79,7 @@ void echo_poll(void) {
     if (fd >= 0) {
       c = (struct echo_client *) calloc(1, sizeof(*c));
       if (c == NULL || !echo_nonblock(fd)) {
-        printf("BSD echo accept: %d\n", c == NULL ? ENOMEM : errno);
+        MG_ERROR(("BSD echo accept: %d", c == NULL ? ENOMEM : errno));
         close(fd);
         free(c);
       } else {

tutorials/stm32/nucleo-h723zg/minimal-bsd-baremetal/main.c

@@ -44,7 +44,12 @@ bool mg_random(void *buf, size_t len) {
 }
 
 static void http_ev_handler(struct mg_connection *c, int ev, void *ev_data) {
-  if (ev == MG_EV_HTTP_MSG) {
+  if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
+  } else if (ev == MG_EV_HTTP_MSG) {
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     if (mg_match(hm->uri, mg_str("/api/tick"), NULL)) {
       mg_http_reply(c, 200, "", "{%m:%llu}\n", MG_ESC("tick"), hal_get_tick());

tutorials/stm32/nucleo-h723zg/minimal-bsd-freertos/main.c

@@ -43,7 +43,12 @@ bool mg_random(void *buf, size_t len) {
 }
 
 static void http_ev_handler(struct mg_connection *c, int ev, void *ev_data) {
-  if (ev == MG_EV_HTTP_MSG) {
+  if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
+  } else if (ev == MG_EV_HTTP_MSG) {
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     if (mg_match(hm->uri, mg_str("/api/tick"), NULL)) {
       mg_http_reply(c, 200, "", "{%m:%llu}\n", MG_ESC("tick"), hal_get_tick());

tutorials/stm32/nucleo-h723zg/minimal-bsd-udp-baremetal/Makefile

@@ -0,0 +1,36 @@
+# Copyright (c) 2026 Cesanta Software Limited
+# Environment setup: https://mongoose.ws/docs/getting-started/build-environment/
+
+MGDIR = ../../../..
+CFLAGS  = -W -Wall -Wextra -Wundef -Wshadow -Wdouble-promotion
+CFLAGS += -Wformat-truncation -fno-common -Wconversion -Wno-sign-conversion
+CFLAGS += -g3 -Os -ffunction-sections -fdata-sections
+CFLAGS += -I. -I$(MGDIR) -Icmsis_core/CMSIS/Core/Include -Icmsis_h7/Include
+CFLAGS += -mcpu=cortex-m7 -mthumb -mfloat-abi=hard -mfpu=fpv5-d16 $(CFLAGS_EXTRA)
+LDFLAGS ?= -Tlink.ld -nostdlib -nostartfiles --specs nosys.specs -lc -lgcc -Wl,--gc-sections -Wl,-Map=$@.map
+
+SOURCES = main.c hal.c udp.c
+SOURCES += cmsis_h7/Source/Templates/gcc/startup_stm32h723xx.s
+SOURCES += $(MGDIR)/mongoose.c
+
+all build example: firmware.bin
+
+firmware.elf: cmsis_core cmsis_h7 hal.h link.ld Makefile $(SOURCES) $(MGDIR)/mongoose.h mongoose_config.h
+	arm-none-eabi-gcc $(SOURCES) $(CFLAGS) $(CFLAGS_EXTRA) $(LDFLAGS) -o $@
+
+firmware.bin: firmware.elf
+	arm-none-eabi-objcopy -O binary $< $@
+	@echo
+	@echo "To flash, run 'make flash', or use STM32CubeProgrammer"
+
+flash: firmware.bin
+	STM32_Programmer_CLI -c port=swd -w firmware.elf -hardRst
+
+cmsis_core:
+	git clone -q -c advice.detachedHead=false --depth 1 -b 5.9.0 https://github.com/ARM-software/CMSIS_5 $@
+
+cmsis_h7:
+	git clone -q -c advice.detachedHead=false --depth 1 -b v1.10.6 https://github.com/STMicroelectronics/cmsis_device_h7 $@
+
+clean:
+	rm -rf firmware.* cmsis_*

tutorials/stm32/nucleo-h723zg/minimal-bsd-udp-baremetal/hal.c

@@ -0,0 +1,125 @@
+// Copyright (c) 2026 Cesanta Software Limited
+// All rights reserved
+
+#include "hal.h"
+
+bool hal_timer_expired(volatile uint64_t *t, uint64_t period, uint64_t now) {
+  uint64_t diff = now - *t;         // Wrap-safe elapsed time since last expiry
+  if (period == 0) return false;    // Avoid division by zero
+  if (diff < period) return false;  // Period has not elapsed yet
+  *t += (diff / period) * period;   // Preserve cadence, skip missed periods
+  return true;
+}
+
+static volatile uint64_t s_ticks;  // Milliseconds since boot
+void SysTick_Handler(void) {       // SyStick IRQ handler, triggered every 1ms
+  s_ticks++;
+}
+
+uint64_t hal_get_tick(void) {
+  return s_ticks;
+};
+
+uint32_t SystemCoreClock = 160000000;
+void SystemInit(void) {  // Called automatically by startup code
+  hal_system_init();     // Enable FPU
+  hal_clock_init();
+  SysTick_Config(SystemCoreClock / 1000);  // Sys tick every 1ms
+}
+
+void ExitRun0Mode(void) {
+}
+
+struct stat;
+__attribute__((weak)) int _fstat(int fd, struct stat *st) {
+  (void) fd, (void) st;
+  return -1;
+}
+
+extern unsigned char _end[];  // End of data section, start of heap. See link.ld
+static unsigned char *s_current_heap_end = _end;
+
+size_t hal_ram_used(void) {
+  return (size_t) (s_current_heap_end - _end);
+}
+
+size_t hal_ram_free(void) {
+  unsigned char endofstack;
+  return (size_t) (&endofstack - s_current_heap_end);
+}
+
+void *_sbrk(int incr) {
+  unsigned char *prev_heap;
+  unsigned char *heap_end = (unsigned char *) ((size_t) &heap_end - 256);
+  prev_heap = s_current_heap_end;
+  // Check how much space we  got from the heap end to the stack end
+  if (s_current_heap_end + incr > heap_end) return (void *) -1;
+  s_current_heap_end += incr;
+  return prev_heap;
+}
+
+__attribute__((weak)) int _open(const char *path) {
+  (void) path;
+  return -1;
+}
+
+__attribute__((weak)) int _close(int fd) {
+  (void) fd;
+  return -1;
+}
+
+__attribute__((weak)) int _isatty(int fd) {
+  (void) fd;
+  return 1;
+}
+
+__attribute__((weak)) int _lseek(int fd, int ptr, int dir) {
+  (void) fd, (void) ptr, (void) dir;
+  return 0;
+}
+
+__attribute__((weak)) void _exit(int status) {
+  (void) status;
+  for (;;) asm volatile("BKPT #0");
+}
+
+__attribute__((weak)) void _kill(int pid, int sig) {
+  (void) pid, (void) sig;
+}
+
+__attribute__((weak)) int _getpid(void) {
+  return -1;
+}
+
+__attribute__((weak)) int _write(int fd, char *ptr, int len) {
+  (void) fd, (void) ptr, (void) len;
+  return -1;
+}
+
+__attribute__((weak)) int _read(int fd, char *ptr, int len) {
+  (void) fd, (void) ptr, (void) len;
+  return -1;
+}
+
+__attribute__((weak)) int _link(const char *a, const char *b) {
+  (void) a, (void) b;
+  return -1;
+}
+
+__attribute__((weak)) int _unlink(const char *a) {
+  (void) a;
+  return -1;
+}
+
+__attribute__((weak)) int _stat(const char *path, struct stat *st) {
+  (void) path, (void) st;
+  return -1;
+}
+
+__attribute__((weak)) int mkdir(const char *path, int mode) {
+  (void) path, (void) mode;
+  return -1;
+}
+
+__attribute__((weak)) void _init(void) {
+}

tutorials/stm32/nucleo-h723zg/minimal-bsd-udp-baremetal/hal.h

@@ -0,0 +1,225 @@
+// Copyright (c) 2022-2026 Cesanta Software Limited
+// Datasheet: RM0468, devboard manual: UM2407
+// https://www.st.com/resource/en/reference_manual/rm0468-stm32h723733-stm32h725735-and-stm32h730-value-line-advanced-armbased-32bit-mcus-stmicroelectronics.pdf
+// https://www.st.com/resource/en/user_manual/um2407-stm32h7-nucleo144-boards-mb1364-stmicroelectronics.pdf
+// Alternate functions: https://www.st.com/resource/en/datasheet/stm32h723.pdf
+
+#pragma once
+
+#include <stm32h723xx.h>
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+
+extern bool hal_timer_expired(volatile uint64_t *t, uint64_t prd, uint64_t now);
+extern uint64_t hal_get_tick(void);
+extern size_t hal_ram_free(void);
+extern size_t hal_ram_used(void);
+extern uint32_t SystemCoreClock;
+
+#define BIT(x) (1UL << (x))
+#define CLRSET(reg, clear, set) ((reg) = ((reg) & ~(clear)) | (set))
+#define PIN(bank, num) ((((bank) - 'A') << 8) | (num))
+#define PINNO(pin) (pin & 255)
+#define PINBANK(pin) (pin >> 8)
+
+#define HAL_ETH_PINS  PIN('A', 1),  PIN('A', 2),  PIN('A', 7), \
+                      PIN('B', 13), PIN('C', 1),  PIN('C', 4), \
+                      PIN('C', 5),  PIN('G', 11), PIN('G', 13)
+
+// System clock (2.1, Figure 1; 8.5, Figure 45; 8.5.5, Figure 47; 8.5.6, Figure
+// 49; 8.5.8 Table 56; datasheet) CPU_FREQUENCY <= 550 MHz; hclk = CPU_FREQUENCY
+// / HAL_HPRE ; hclk <= 275 MHz; APB clocks <= 137.5 MHz. D1 domain bus matrix (and
+// so flash) runs at hclk frequency. Configure flash latency (WS) in accordance
+// to hclk freq (4.3.8, Table 16) The Ethernet controller is in D2 domain and
+// runs at hclk frequency
+enum {
+  HAL_D1CPRE = 1,  // actual divisor value
+  HAL_HPRE = 2,    // actual divisor value
+  HAL_D1PPRE = 4,  // register values, divisor value = BIT(value - 3) = / 2
+  HAL_D2PPRE1 = 4,
+  HAL_D2PPRE2 = 4,
+  HAL_D3PPRE = 4
+};
+// PLL1_P: odd division factors are not allowed (8.7.12) (except for '1')
+enum { PLL1_HSI = 64, PLL1_M = 32, PLL1_N = 225, PLL1_P = 1 };
+#define HAL_FLASH_LATENCY 0x33  // WRHIGHFREQ LATENCY
+#define SYS_FREQUENCY ((PLL1_HSI * PLL1_N / PLL1_M / PLL1_P / HAL_D1CPRE) * 1000000)
+#define AHB_FREQUENCY (SYS_FREQUENCY / HAL_HPRE)
+#define APB2_FREQUENCY (AHB_FREQUENCY / (BIT(HAL_D2PPRE2 - 3)))
+#define APB1_FREQUENCY (AHB_FREQUENCY / (BIT(HAL_D2PPRE1 - 3)))
+
+
+enum { HAL_GPIO_MODE_INPUT, HAL_GPIO_MODE_OUTPUT, HAL_GPIO_MODE_AF, HAL_GPIO_MODE_ANALOG };
+enum { HAL_GPIO_OTYPE_PUSH_PULL, HAL_GPIO_OTYPE_OPEN_DRAIN };
+enum { HAL_GPIO_SPEED_LOW, HAL_GPIO_SPEED_MEDIUM, HAL_GPIO_SPEED_HIGH, HAL_GPIO_SPEED_INSANE };
+enum { HAL_GPIO_PULL_NONE, HAL_GPIO_PULL_UP, HAL_GPIO_PULL_DOWN };
+
+#define HAL_GPIO(N) ((GPIO_TypeDef *) (0x40000000 + 0x18020000UL + 0x400 * (N)))
+
+static GPIO_TypeDef *hal_gpio_bank(uint16_t pin) {
+  return HAL_GPIO(PINBANK(pin));
+}
+static inline void hal_gpio_toggle(uint16_t pin) {
+  GPIO_TypeDef *gpio = hal_gpio_bank(pin);
+  uint32_t mask = BIT(PINNO(pin));
+  gpio->BSRR = mask << (gpio->ODR & mask ? 16 : 0);
+}
+static inline int hal_gpio_read(uint16_t pin) {
+  return hal_gpio_bank(pin)->IDR & BIT(PINNO(pin)) ? 1 : 0;
+}
+static inline void hal_gpio_write(uint16_t pin, bool val) {
+  GPIO_TypeDef *gpio = hal_gpio_bank(pin);
+  gpio->BSRR = BIT(PINNO(pin)) << (val ? 0 : 16);
+}
+static inline void hal_gpio_init(uint16_t pin, uint8_t mode, uint8_t type,
+                             uint8_t speed, uint8_t pull, uint8_t af) {
+  GPIO_TypeDef *gpio = hal_gpio_bank(pin);
+  uint8_t n = (uint8_t) (PINNO(pin));
+  RCC->AHB4ENR |= BIT(PINBANK(pin));  // Enable GPIO clock
+  CLRSET(gpio->OTYPER, 1UL << n, ((uint32_t) type) << n);
+  CLRSET(gpio->OSPEEDR, 3UL << (n * 2), ((uint32_t) speed) << (n * 2));
+  CLRSET(gpio->PUPDR, 3UL << (n * 2), ((uint32_t) pull) << (n * 2));
+  CLRSET(gpio->AFR[n >> 3], 15UL << ((n & 7) * 4),
+          ((uint32_t) af) << ((n & 7) * 4));
+  CLRSET(gpio->MODER, 3UL << (n * 2), ((uint32_t) mode) << (n * 2));
+}
+static inline void hal_gpio_input(uint16_t pin) {
+  hal_gpio_init(pin, HAL_GPIO_MODE_INPUT, HAL_GPIO_OTYPE_PUSH_PULL, HAL_GPIO_SPEED_HIGH,
+      HAL_GPIO_PULL_NONE, 0);
+}
+static inline void hal_gpio_output(uint16_t pin) {
+  hal_gpio_init(pin, HAL_GPIO_MODE_OUTPUT, HAL_GPIO_OTYPE_PUSH_PULL, HAL_GPIO_SPEED_HIGH,
+      HAL_GPIO_PULL_NONE, 0);
+}
+
+// D2 Kernel clock (8.7.21) USART1 defaults to pclk2 (APB2), while USART2,3
+// default to pclk1 (APB1). Even if using other kernel clocks, the APBx clocks
+// must be enabled for CPU access, as the kernel clock drives the BRR, not the
+// APB bus interface
+static inline void hal_uart_init(USART_TypeDef *uart, uint16_t tx,
+                                 uint16_t rx, unsigned long baud) {
+  uint8_t af = 7;           // Alternate function
+  uint32_t freq = 0;        // Bus frequency. UART1 is on APB2, rest on APB1
+
+  if (uart == USART1) freq = APB2_FREQUENCY, RCC->APB2ENR |= BIT(4);
+  if (uart == USART2) freq = APB1_FREQUENCY, RCC->APB1LENR |= BIT(17);
+  if (uart == USART3) freq = APB1_FREQUENCY, RCC->APB1LENR |= BIT(18);
+
+#if 0  // CONSTANT BAUD RATE FOR REMOTE DEBUGGING WHILE SETTING THE PLL
+  CLRSET(RCC->D2CCIP2R, 7 << 3, 3 << 3);  // use HSI for UART1
+  freq = 64000000;
+#endif
+
+  hal_gpio_init(tx, HAL_GPIO_MODE_AF, HAL_GPIO_OTYPE_PUSH_PULL, HAL_GPIO_SPEED_HIGH, 0, af);
+  hal_gpio_init(rx, HAL_GPIO_MODE_AF, HAL_GPIO_OTYPE_PUSH_PULL, HAL_GPIO_SPEED_HIGH, 0, af);
+  uart->CR1 = 0;                         // Disable this UART
+  uart->BRR = freq / baud;               // Set baud rate
+  uart->CR1 = BIT(0) | BIT(2) | BIT(3);  // Set UE, RE, TE
+}
+static inline void hal_uart_write_byte(USART_TypeDef *uart, uint8_t byte) {
+  uart->TDR = byte;
+  while ((uart->ISR & USART_ISR_TXE_TXFNF) == 0) (void) 0;
+}
+static inline void hal_uart_write_buf(USART_TypeDef *uart, char *buf, size_t len) {
+  while (len-- > 0) hal_uart_write_byte(uart, *(uint8_t *) buf++);
+}
+static inline int hal_uart_read_ready(USART_TypeDef *uart) {
+  return uart->ISR & BIT(5);  // If RXNE bit is set, data is ready
+}
+static inline uint8_t hal_uart_read_byte(USART_TypeDef *uart) {
+  return (uint8_t) (uart->RDR & 255);
+}
+
+// RNG clock (rng_clk) defaults to HSI48 and is characterized at this frequency.
+// Enable at SystemInit. (STM32CubeMX) It won't work with a 275MHz (AHB)
+static inline void hal_rng_init(void) {
+  RCC->AHB2ENR |= RCC_AHB2ENR_RNGEN;  // Enable RNG AHB clock (hal_rng_hclk)
+  // 39.6.2 Table 320 init
+  RNG->CR = RNG_CR_CONDRST | (0x0F << RNG_CR_RNG_CONFIG1_Pos) |
+            (0 << RNG_CR_RNG_CONFIG2_Pos) | (0xD << RNG_CR_RNG_CONFIG3_Pos);
+  RNG->HTCR = 0x17590abc;
+  RNG->HTCR = 0xaa74;
+  RNG->CR &= ~RNG_CR_CONDRST ;
+  while (RNG->CR & RNG_CR_CONDRST) (void) 0;  // 39.7.1
+  RNG->CR |= RNG_CR_RNGEN;  // Enable RNG
+}
+
+static inline uint32_t hal_rng_read(void) {
+  while ((RNG->SR & RNG_SR_DRDY) == 0) (void) 0;
+  return RNG->DR;
+}
+
+// Hw pull-ups on PHY RXD0,1,DV to enable autonegotiation
+static inline void hal_ethernet_init(void) {
+  // Initialise Ethernet. Enable MAC GPIO pins, see
+  // https://www.st.com/resource/en/user_manual/um2407-stm32h7-nucleo144-boards-mb1364-stmicroelectronics.pdf
+  uint16_t pins[] = {HAL_ETH_PINS};
+  for (size_t i = 0; i < sizeof(pins) / sizeof(pins[0]); i++) {
+    hal_gpio_init(pins[i], HAL_GPIO_MODE_AF, HAL_GPIO_OTYPE_PUSH_PULL, HAL_GPIO_SPEED_INSANE,
+        HAL_GPIO_PULL_NONE, 11);  // 11 is the Ethernet function
+  }
+  NVIC_EnableIRQ(ETH_IRQn);                     // Setup Ethernet IRQ handler
+  CLRSET(SYSCFG->PMCR, 7 << 21, 4 << 21);      // Use RMII (12.3.1)
+  RCC->AHB1ENR |= BIT(15) | BIT(16) | BIT(17);  // Enable Ethernet clocks
+}
+
+static inline unsigned int hal_div2prescval(unsigned int div) {
+  // 0 --> /1; 8 --> /2 ... 11 --> /16;  12 --> /64 ... 15 --> /512
+  if (div == 1) return 0;
+  if (div > 16) div /= 2;
+  unsigned int val = 7;
+  while (div >>= 1) ++val;
+  return val;
+}
+
+static inline unsigned int hal_pllrge(unsigned int f) {
+  unsigned int val = 0;
+  while (f >>= 1) ++val;
+  return val - 1;
+}
+
+// Enable RTC/BKP APB clock and backup domain write access.
+// Must be called before accessing RTC backup registers or IWDG.
+static inline void hal_backup_domain_init(void) {
+  RCC->APB4ENR |= RCC_APB4ENR_RTCAPBEN;  // enable RTC/BKP APB clock
+  PWR->CR1 |= PWR_CR1_DBP;               // enable backup domain write access
+}
+
+static inline void hal_clock_init(void) {
+  hal_backup_domain_init();
+  PWR->CR3 |= PWR_CR3_LDOEN;                   // select LDO (reset value)
+  while ((PWR->CSR1 & PWR_CSR1_ACTVOSRDY) == 0) (void) 0;  // ACTVOSRDY
+  PWR->D3CR &= ~PWR_D3CR_VOS_Msk;              // Select VOS0
+  while ((PWR->D3CR & PWR_D3CR_VOSRDY) == 0) (void) 0;  // VOSRDY
+  CLRSET(
+      RCC->D1CFGR, (0x0F << 8) | (7 << 4) | (0x0F << 0),
+      (hal_div2prescval(HAL_D1CPRE) << 8) | (HAL_D1PPRE << 4) | (hal_div2prescval(HAL_HPRE) << 0));
+  RCC->D2CFGR = (HAL_D2PPRE2 << 8) | (HAL_D2PPRE1 << 4);
+  RCC->D3CFGR = (HAL_D3PPRE << 4);
+  CLRSET(RCC->PLLCFGR, 3 << 2,
+          hal_pllrge(PLL1_HSI / PLL1_M)
+              << 2);  // keep reset config (DIVP1EN, !PLL1VCOSEL), PLL1RGE
+  CLRSET(RCC->PLL1DIVR, (0x7F << 9) | (0x1FF << 0),
+          ((PLL1_P - 1) << 9) | ((PLL1_N - 1) << 0));  // Set PLL1_P PLL1_N
+  CLRSET(RCC->PLLCKSELR, 0x3F << 4,
+          PLL1_M << 4);          // Set PLL1_M (source defaults to HSI)
+  RCC->CR |= RCC_CR_PLL1ON | RCC_CR_HSI48ON;  // Enable PLL1 and HSI48 (for RNG)
+  while ((RCC->CR & RCC_CR_PLL1RDY) == 0) (void) 0;  // Wait until done
+  RCC->CFGR |= (3 << 0);                      // Set clock source to PLL1
+  while ((RCC->CFGR & (7 << 3)) != (3 << 3)) (void) 0;  // Wait until done
+  FLASH->ACR = HAL_FLASH_LATENCY;             // default is larger
+  RCC->APB4ENR |= RCC_APB4ENR_SYSCFGEN;       // Enable SYSCFG
+  while ((RCC->CR & RCC_CR_HSI48RDY) == 0) (void) 0;  // Make sure HSI48 is ready
+  SystemCoreClock = SYS_FREQUENCY;         // Update SystemCoreClock global var
+  SysTick_Config(SystemCoreClock / 1000);  // Sys tick every 1ms
+}
+
+
+static inline void hal_system_init(void) {
+  SCB->CPACR |= ((3UL << 10 * 2) | (3UL << 11 * 2));  // Enable FPU
+  __DSB();
+  __ISB();
+}

tutorials/stm32/nucleo-h723zg/minimal-bsd-udp-baremetal/link.ld

@@ -0,0 +1,32 @@
+ENTRY(Reset_Handler);
+MEMORY {
+  flash(rx) : ORIGIN = 0x08000000, LENGTH = 1024k
+
+  dtcmram (rwx) : ORIGIN = 0x20000000, LENGTH = 128K
+  ram_d1 (rwx)  : ORIGIN = 0x24000000, LENGTH = 320K
+  ram_d2 (rwx)  : ORIGIN = 0x30000000, LENGTH = 32K
+  ram_d3 (rwx)  : ORIGIN = 0x38000000, LENGTH = 16K
+  itcmram (rwx) : ORIGIN = 0x00000000, LENGTH = 64K
+}
+_estack     = ORIGIN(ram_d1) + LENGTH(ram_d1);
+
+SECTIONS {
+  .vectors  : { KEEP(*(.isr_vector)) }  > flash
+  .text     : { *(.text* .text.*) }     > flash
+  .rodata   : { *(.rodata*) }           > flash
+
+  /* Note the .iram section, for functions copied to RAM. Required for MG_IRAM OTA support */
+  .data : { _sdata = .; *(.first_data) *(.iram .iram* .iram.*) *(.data SORT(.data.*)) _edata = .; } > ram_d1 AT > flash
+  _sidata = LOADADDR(.data);
+
+  .bss : { _sbss = .; *(.bss SORT(.bss.*) COMMON) _ebss = .; } > ram_d1
+
+  .eth_ram : { *(.eth_ram .eth_ram*) } > ram_d1 AT > flash
+
+  /* Health record. NOLOAD and in unused DTCM, so startup code neither copies
+     nor zeroes it and the contents survive a warm reset */
+  .mg_health (NOLOAD) : { KEEP(*(.mg_health .mg_health*)) } > dtcmram
+
+  . = ALIGN(8);
+  _end = .;
+}

tutorials/stm32/nucleo-h723zg/minimal-bsd-udp-baremetal/main.c

@@ -0,0 +1,69 @@
+// Copyright (c) 2026 Cesanta Software Limited
+// All rights reserved
+
+#include "hal.h"
+#include "mongoose.h"
+
+int udp_init(uint16_t port);
+void udp_poll(void);
+
+#ifndef UART_DEBUG
+#define UART_DEBUG USART3
+#define UART_DEBUG_TX_PIN PIN('D', 8)
+#define UART_DEBUG_RX_PIN PIN('D', 9)
+#else
+#define UART_DEBUG_TX_PIN PIN('A', 9)
+#define UART_DEBUG_RX_PIN PIN('A', 10)
+#endif
+
+#define LED1 PIN('B', 0)
+#define LED2 PIN('E', 1)
+#define LED3 PIN('B', 14)
+
+static void log_fn(char ch, void *param) {
+  hal_uart_write_buf(param, &ch, 1);
+}
+
+static void blink_task(void) {
+  static uint64_t blink_timer = 0;
+  if (hal_timer_expired(&blink_timer, 500, hal_get_tick())) {
+    hal_gpio_toggle(LED2);
+  }
+}
+
+uint64_t mg_millis(void) {
+  return hal_get_tick();
+}
+
+bool mg_random(void *buf, size_t len) {
+  for (size_t n = 0; n < len; n += sizeof(uint32_t)) {
+    uint32_t r = hal_rng_read();
+    memcpy((char *) buf + n, &r, n + sizeof(r) > len ? len - n : sizeof(r));
+  }
+  return true;
+}
+
+int main(void) {
+  struct mg_mgr mgr;
+
+  hal_clock_init();
+  hal_uart_init(UART_DEBUG, UART_DEBUG_TX_PIN, UART_DEBUG_RX_PIN, 115200);
+  mg_log_set_fn(log_fn, UART_DEBUG);
+  hal_rng_init();
+  hal_ethernet_init();
+  hal_gpio_output(LED1);
+  hal_gpio_output(LED2);
+  hal_gpio_output(LED3);
+
+  MG_INFO(("Initialised. CPU clock: %lu MHz", SystemCoreClock / 1000000));
+  mg_mgr_init(&mgr);
+  udp_init(1234);
+
+  for (;;) {
+    mg_mgr_poll(&mgr, 0);
+    udp_poll();
+    blink_task();
+  }
+
+  return 0;
+}

tutorials/stm32/nucleo-h723zg/minimal-bsd-udp-baremetal/mongoose_config.h

@@ -0,0 +1,37 @@
+#pragma once
+#include "hal.h"
+
+// See https://mongoose.ws/docs/getting-started/build-options/
+#define MG_ARCH MG_ARCH_ARMGCC
+#define MG_TLS MG_TLS_BUILTIN
+#define MG_OTA MG_OTA_STM32H7
+
+#define MG_ENABLE_TCPIP 1
+#define MG_ENABLE_BSD_SOCKETS 1
+#define MG_ENABLE_CUSTOM_MILLIS 1
+#define MG_ENABLE_CUSTOM_RANDOM 1
+#define MG_ENABLE_DRIVER_STM32H 1
+#define MG_ENABLE_PACKED_FS 1
+#define MG_ETH_RAM __attribute__((section(".eth_ram")))
+
+// #define MG_DRIVER_MDC_CR 4   // RMII MDC clock divider, from 0 to 5
+// #define MG_TCPIP_PHY_ADDR 0  // PHY address
+
+// For static IP configuration, define MG_TCPIP_{IP,MASK,GW}
+// By default, those are set to zero, meaning that DHCP is used
+//
+// #define MG_TCPIP_IP MG_IPV4(192, 168, 0, 10)     // IP
+// #define MG_TCPIP_GW MG_IPV4(192, 168, 0, 1)      // Gateway
+// #define MG_TCPIP_MASK MG_IPV4(255, 255, 255, 0)  // Netmask
+
+// Construct MAC address from the MCU unique ID
+#define MGUID ((uint32_t *) UID_BASE)
+#define MG_SET_MAC_ADDRESS(mac)      \
+  do {                               \
+    mac[0] = 2;                      \
+    mac[1] = MGUID[0] & 255;         \
+    mac[2] = (MGUID[0] >> 10) & 255; \
+    mac[3] = (MGUID[0] >> 19) & 255; \
+    mac[4] = MGUID[1] & 255;         \
+    mac[5] = MGUID[2] & 255;         \
+  } while (0)

tutorials/stm32/nucleo-h723zg/minimal-bsd-udp-baremetal/udp.c

@@ -0,0 +1,68 @@
+// Copyright (c) 2026 Cesanta Software Limited
+// All rights reserved
+
+#include "mongoose.h"
+
+struct udp_server {
+  int fd;
+  bool pending;
+  struct sockaddr_in peer;
+  socklen_t peerlen;
+  size_t len;
+  char buf[128];
+};
+
+static struct udp_server s_server = {.fd = -1};
+
+static int udp_nonblock(int fd) {
+  int flags = fcntl(fd, F_GETFL, 0);
+  return flags >= 0 && fcntl(fd, F_SETFL, flags | O_NONBLOCK) == 0;
+}
+
+int udp_init(uint16_t port) {
+  struct sockaddr_in sa = {
+      .sin_family = AF_INET,
+      .sin_port = htons(port),
+      .sin_addr = {.s_addr = INADDR_ANY},
+  };
+  int fd = socket(AF_INET, SOCK_DGRAM, 0);
+
+  if (fd < 0 || !udp_nonblock(fd) ||
+      bind(fd, (struct sockaddr *) &sa, sizeof(sa)) < 0) {
+    MG_ERROR(("BSD UDP init: %d", errno));
+    if (fd >= 0) close(fd);
+    return 0;
+  }
+  s_server.fd = fd;
+  MG_INFO(("BSD UDP echo server on port %hu", port));
+  return 1;
+}
+
+void udp_poll(void) {
+  struct udp_server *s = &s_server;
+  struct pollfd p;
+  ssize_t n;
+
+  if (s->fd < 0) return;
+  p.fd = s->fd, p.events = s->pending ? POLLOUT : POLLIN, p.revents = 0;
+  if (poll(&p, 1, 0) <= 0) return;
+  if (s->pending) {
+    n = sendto(s->fd, s->buf, s->len, 0, (struct sockaddr *) &s->peer,
+               s->peerlen);
+    if (n == (ssize_t) s->len) {
+      s->pending = false;
+    } else if (n < 0 && errno != EAGAIN) {
+      MG_ERROR(("BSD UDP send: %d", errno));
+      s->pending = false;
+    }
+  } else {
+    s->peerlen = sizeof(s->peer);
+    n = recvfrom(s->fd, s->buf, sizeof(s->buf), 0,
+                 (struct sockaddr *) &s->peer, &s->peerlen);
+    if (n >= 0) {
+      s->len = (size_t) n, s->pending = true;
+    } else if (errno != EAGAIN) {
+      MG_ERROR(("BSD UDP recv: %d", errno));
+    }
+  }
+}

tutorials/stm32/nucleo-h723zg/minimal/main.c

@@ -68,6 +68,11 @@ static void http_ev_handler(struct mg_connection *c, int ev, void *ev_data) {
     struct mg_tls_opts opts = {.cert = mg_str(TLS_CERT),
                                .key = mg_str(TLS_KEY)};
     mg_tls_init(c, &opts);
+  } else if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
   } else if (ev == MG_EV_HTTP_MSG) {
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     if (mg_match(hm->uri, mg_str("/api/tick"), NULL)) {

tutorials/stm32/nucleo-h743zi/minimal/main.c

@@ -68,6 +68,11 @@ static void http_ev_handler(struct mg_connection *c, int ev, void *ev_data) {
     struct mg_tls_opts opts = {.cert = mg_str(TLS_CERT),
                                .key = mg_str(TLS_KEY)};
     mg_tls_init(c, &opts);
+  } else if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
   } else if (ev == MG_EV_HTTP_MSG) {  // New HTTP request received
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     if (mg_match(hm->uri, mg_str("/api/tick"), NULL)) {

tutorials/stm32/nucleo-n657x0-q/minimal/main.c

@@ -64,6 +64,11 @@ static void http_ev_handler(struct mg_connection *c, int ev, void *ev_data) {
     struct mg_tls_opts opts = {.cert = mg_str(TLS_CERT),
                                .key = mg_str(TLS_KEY)};
     mg_tls_init(c, &opts);
+  } else if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
   } else if (ev == MG_EV_HTTP_MSG) {  // New HTTP request received
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     if (mg_match(hm->uri, mg_str("/api/tick"), NULL)) {

tutorials/stm32/nucleo-u5a5zj-q/minimal/main.c

@@ -60,6 +60,11 @@ static void http_ev_handler(struct mg_connection *c, int ev, void *ev_data) {
     struct mg_tls_opts opts = {.cert = mg_str(TLS_CERT),
                                .key = mg_str(TLS_KEY)};
     mg_tls_init(c, &opts);
+  } else if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
   } else if (ev == MG_EV_HTTP_MSG) {  // New HTTP request received
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     if (mg_match(hm->uri, mg_str("/api/tick"), NULL)) {

tutorials/stm32/portenta-h7/minimal/main.c

@@ -68,6 +68,11 @@ static void http_ev_handler(struct mg_connection *c, int ev, void *ev_data) {
     struct mg_tls_opts opts = {.cert = mg_str(TLS_CERT),
                                .key = mg_str(TLS_KEY)};
     mg_tls_init(c, &opts);
+  } else if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
   } else if (ev == MG_EV_HTTP_MSG) {  // New HTTP request received
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     if (mg_match(hm->uri, mg_str("/api/tick"), NULL)) {

tutorials/stm32/stm32h573i-dk/minimal/main.c

@@ -68,6 +68,11 @@ static void http_ev_handler(struct mg_connection *c, int ev, void *ev_data) {
     struct mg_tls_opts opts = {.cert = mg_str(TLS_CERT),
                                .key = mg_str(TLS_KEY)};
     mg_tls_init(c, &opts);
+  } else if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
   } else if (ev == MG_EV_HTTP_MSG) {  // New HTTP request received
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     if (mg_match(hm->uri, mg_str("/api/tick"), NULL)) {

tutorials/stm32/stm32h747i-disco/minimal/main.c

@@ -68,6 +68,11 @@ static void http_ev_handler(struct mg_connection *c, int ev, void *ev_data) {
     struct mg_tls_opts opts = {.cert = mg_str(TLS_CERT),
                                .key = mg_str(TLS_KEY)};
     mg_tls_init(c, &opts);
+  } else if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
   } else if (ev == MG_EV_HTTP_MSG) {  // New HTTP request received
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     if (mg_match(hm->uri, mg_str("/api/tick"), NULL)) {

tutorials/ti/ek-tm4c1294xl-make-baremetal-builtin-rndis/main.c

@@ -63,7 +63,12 @@ static bool usb_poll(struct mg_tcpip_if *ifp, bool s1) {
 }
 
 static void fn(struct mg_connection *c, int ev, void *ev_data) {
-  if (ev == MG_EV_HTTP_MSG) {
+  if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
+  } else if (ev == MG_EV_HTTP_MSG) {
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     if (mg_match(hm->uri, mg_str("/api/debug"), NULL)) {
       int level = mg_json_get_long(hm->body, "$.level", MG_LL_DEBUG);

tutorials/wch/ch32v307-make-baremetal-builtin/main.c

@@ -30,7 +30,12 @@ static void timer_fn(void *arg) {
 
 // https://mongoose.ws/documentation/#2-minute-integration-guide
 static void fn(struct mg_connection *c, int ev, void *ev_data) {
-  if (ev == MG_EV_HTTP_MSG) {
+  if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
+  } else if (ev == MG_EV_HTTP_MSG) {
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     mg_http_reply(c, 200, "", "ok %p\r\n", hm);
   }

tutorials/zephyr/http-server/src/main.c

@@ -14,6 +14,11 @@ static void wcb(struct mg_connection *c, int ev, void *ev_data) {
   if (ev == MG_EV_ACCEPT && c->is_tls) {
     struct mg_tls_opts opts = {.cert = (char *) s_ssl_cert, .key = (char *) s_ssl_key};
     mg_tls_init(c, &opts);
+  } else if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/ota"), NULL)) {
+      mg_http_stream_body(c, hm, mg_http_ota_cb, NULL);
+    }
   } else if (ev == MG_EV_HTTP_MSG) {
     struct mg_http_message *hm = ev_data;
     MG_INFO(("%.*s %.*s %ld", (int) hm->method.len, hm->method.buf,