Decouple from Ethernet, introduce "l2"

mongoose.h

@@ -1242,6 +1242,7 @@ size_t mg_print_ip_port(void (*out)(char, void *), void *arg, va_list *ap);
 size_t mg_print_ip4(void (*out)(char, void *), void *arg, va_list *ap);
 size_t mg_print_ip6(void (*out)(char, void *), void *arg, va_list *ap);
 size_t mg_print_mac(void (*out)(char, void *), void *arg, va_list *ap);
+size_t mg_print_l2addr(void (*out)(char, void *), void *arg, va_list *ap);
 
 // Various output functions
 void mg_pfn_iobuf(char ch, void *param);  // param: struct mg_iobuf *
@@ -3148,6 +3149,62 @@ bool mg_wifi_ap_stop(void);
 
 
 
+#if MG_ENABLE_TCPIP
+
+// no config defaults to 0 => Ethernet
+enum mg_l2type { MG_TCPIP_L2_ETH = 0, MG_TCPIP_L2_PPP };  // MG_TCPIP_L2_PPPoE
+
+#if defined(__DCC__)
+#pragma pack(1)
+#else
+#pragma pack(push, 1)
+#endif
+
+struct mg_l2addr {
+  union {
+    uint8_t mac[6];
+  } addr;
+};
+
+#if defined(__DCC__)
+#pragma pack(0)
+#else
+#pragma pack(pop)
+#endif
+
+#if 0
+TODO(): ?
+struct eth_opts {
+  bool enable_crc32_check;         // Do a CRC check on RX frames and strip it
+  bool enable_mac_check;           // Do a MAC check on RX frames
+};
+struct mg_l2opts {
+  union {
+    struct eth_opts eth;
+  };
+};
+#endif
+
+enum mg_l2proto {
+  MG_TCPIP_L2PROTO_IPV4 = 0,
+  MG_TCPIP_L2PROTO_IPV6,
+  MG_TCPIP_L2PROTO_ARP,
+  MG_TCPIP_L2PROTO_PPPoE_DISC,
+  MG_TCPIP_L2PROTO_PPPoE_SESS
+};
+enum mg_l2addrtype {
+  MG_TCPIP_L2ADDR_BCAST,
+  MG_TCPIP_L2ADDR_MCAST,
+  MG_TCPIP_L2ADDR_MCAST6
+};
+
+#endif
+
+
+
+
+
+
 
 
 #if MG_ENABLE_TCPIP
@@ -3165,29 +3222,32 @@ typedef void (*mg_tcpip_event_handler_t)(struct mg_tcpip_if *ifp, int ev,
                                          void *ev_data);
 
 enum {
-  MG_TCPIP_EV_ST_CHG,           // state change                   uint8_t * (&ifp->state)
-  MG_TCPIP_EV_DHCP_DNS,         // DHCP DNS assignment            uint32_t *ipaddr
-  MG_TCPIP_EV_DHCP_SNTP,        // DHCP SNTP assignment           uint32_t *ipaddr
-  MG_TCPIP_EV_ARP,              // Got ARP packet                 struct mg_str *
-  MG_TCPIP_EV_TIMER_1S,         // 1 second timer                 NULL
-  MG_TCPIP_EV_WIFI_SCAN_RESULT, // Wi-Fi scan results             struct mg_wifi_scan_bss_data *
-  MG_TCPIP_EV_WIFI_SCAN_END,    // Wi-Fi scan has finished        NULL
-  MG_TCPIP_EV_WIFI_CONNECT_ERR, // Wi-Fi connect has failed       driver and chip specific
-  MG_TCPIP_EV_DRIVER,           // Driver event                   driver specific
-  MG_TCPIP_EV_ST6_CHG,          // state6 change                  uint8_t * (&ifp->state6)
-  MG_TCPIP_EV_USER              // Starting ID for user events
+  MG_TCPIP_EV_ST_CHG,  // state change                   uint8_t * (&ifp->state)
+  MG_TCPIP_EV_DHCP_DNS,   // DHCP DNS assignment            uint32_t *ipaddr
+  MG_TCPIP_EV_DHCP_SNTP,  // DHCP SNTP assignment           uint32_t *ipaddr
+  MG_TCPIP_EV_ARP,        // Got ARP packet                 struct mg_str *
+  MG_TCPIP_EV_TIMER_1S,   // 1 second timer                 NULL
+  MG_TCPIP_EV_WIFI_SCAN_RESULT,  // Wi-Fi scan results             struct
+                                 // mg_wifi_scan_bss_data *
+  MG_TCPIP_EV_WIFI_SCAN_END,     // Wi-Fi scan has finished        NULL
+  MG_TCPIP_EV_WIFI_CONNECT_ERR,  // Wi-Fi connect has failed       driver and
+                                 // chip specific
+  MG_TCPIP_EV_DRIVER,   // Driver event                   driver specific
+  MG_TCPIP_EV_ST6_CHG,  // state6 change                  uint8_t *
+                        // (&ifp->state6)
+  MG_TCPIP_EV_USER      // Starting ID for user events
 };
 
 // Network interface
 struct mg_tcpip_if {
-  uint8_t mac[6];                  // MAC address. Must be set to a valid MAC
-  uint32_t ip, mask, gw;           // IP address, mask, default gateway
-  struct mg_str tx;                // Output (TX) buffer
-  bool enable_dhcp_client;         // Enable DCHP client
-  bool enable_dhcp_server;         // Enable DCHP server
-  bool enable_get_gateway;         // DCHP server sets client as gateway
-  bool enable_req_dns;             // DCHP client requests DNS server
-  bool enable_req_sntp;            // DCHP client requests SNTP server
+  uint8_t mac[sizeof(struct mg_l2addr)];  // hw address. Set to a valid addr
+  uint32_t ip, mask, gw;                  // IP address, mask, default gateway
+  struct mg_str tx;                       // Output (TX) buffer
+  bool enable_dhcp_client;                // Enable DCHP client
+  bool enable_dhcp_server;                // Enable DCHP server
+  bool enable_get_gateway;                // DCHP server sets client as gateway
+  bool enable_req_dns;                    // DCHP client requests DNS server
+  bool enable_req_sntp;                   // DCHP client requests SNTP server
   bool enable_crc32_check;         // Do a CRC check on RX frames and strip it
   bool enable_mac_check;           // Do a MAC check on RX frames
   bool update_mac_hash_table;      // Signal drivers to update MAC controller
@@ -3198,21 +3258,22 @@ struct mg_tcpip_if {
   struct mg_mgr *mgr;              // Mongoose event manager
   struct mg_queue recv_queue;      // Receive queue
   char dhcp_name[MG_TCPIP_DHCPNAME_SIZE];  // Name for DHCP, "mip" if unset
-  uint16_t mtu;                            // Interface MTU
-#define MG_TCPIP_MTU_DEFAULT 1500
+  uint16_t mtu;                            // Interface link payload
+  uint16_t framesize;                      // Interface frame max length
 #if MG_ENABLE_IPV6
-  uint64_t ip6ll[2], ip6[2];       // IPv6 link-local and global addresses
-  uint8_t prefix[8];               // IPv6 global address prefix
-  uint8_t prefix_len;              // Prefix length
-  uint64_t gw6[2];                 // Default gateway
-  bool enable_slaac;               // Enable IPv6 address autoconfiguration
-  bool enable_dhcp6_client;        // Enable DCHPv6 client
+  uint64_t ip6ll[2], ip6[2];  // IPv6 link-local and global addresses,
+  uint8_t prefix[8];          // prefix,
+  uint8_t prefix_len;         // prefix length,
+  uint64_t gw6[2];            // default gateway.
+  bool enable_slaac;          // Enable IPv6 address autoconfiguration
+  bool enable_dhcp6_client;   // Enable DCHPv6 client TODO()
 #endif
 
   // Internal state, user can use it but should not change it
-  uint8_t gwmac[6];             // Router's MAC
-  char *dns4_url;               // DNS server URL
-  uint64_t now;                 // Current time
+  uint8_t gwmac[sizeof(struct mg_l2addr)];  // Router's hw address
+  enum mg_l2type l2type;                    // Ethernet, PPP, etc.
+  char *dns4_url;                           // DNS server URL
+  uint64_t now;                             // Current time
   uint64_t timer_1000ms;        // 1000 ms timer: for DHCP and link state
   uint64_t lease_expire;        // Lease expiration time, in ms
   uint16_t eport;               // Next ephemeral port
@@ -3228,11 +3289,12 @@ struct mg_tcpip_if {
 #define MG_TCPIP_STATE_READY 4  // Interface has fully come up, ready to work
   bool gw_ready;                // We've got a hw address for the router
 #if MG_ENABLE_IPV6
-  uint8_t gw6mac[6];             // IPv6 Router's MAC
-  uint8_t state6;                // Current IPv6 state
-  bool gw6_ready;                // We've got a hw address for the IPv6 router
+  uint8_t gw6mac[sizeof(struct mg_l2addr)];  // IPV6 Router's hw address
+  uint8_t state6;                            // Current IPv6 state
+  bool gw6_ready;  // We've got a hw address for the IPv6 router
 #endif
 };
+
 void mg_tcpip_init(struct mg_mgr *, struct mg_tcpip_if *);
 void mg_tcpip_free(struct mg_tcpip_if *);
 void mg_tcpip_qwrite(void *buf, size_t len, struct mg_tcpip_if *ifp);
@@ -3264,39 +3326,38 @@ struct mg_tcpip_spi {
   uint8_t (*txn)(void *, uint8_t);  // SPI transaction: write 1 byte, read reply
 };
 
-
 // Alignment and memory section requirements
 #ifndef MG_8BYTE_ALIGNED
 #if defined(__GNUC__)
 #define MG_8BYTE_ALIGNED __attribute__((aligned((8U))))
 #else
 #define MG_8BYTE_ALIGNED
-#endif // compiler
-#endif // 8BYTE_ALIGNED
+#endif  // compiler
+#endif  // 8BYTE_ALIGNED
 
 #ifndef MG_16BYTE_ALIGNED
 #if defined(__GNUC__)
 #define MG_16BYTE_ALIGNED __attribute__((aligned((16U))))
 #else
 #define MG_16BYTE_ALIGNED
-#endif // compiler
-#endif // 16BYTE_ALIGNED
+#endif  // compiler
+#endif  // 16BYTE_ALIGNED
 
 #ifndef MG_32BYTE_ALIGNED
 #if defined(__GNUC__)
 #define MG_32BYTE_ALIGNED __attribute__((aligned((32U))))
 #else
 #define MG_32BYTE_ALIGNED
-#endif // compiler
-#endif // 32BYTE_ALIGNED
+#endif  // compiler
+#endif  // 32BYTE_ALIGNED
 
 #ifndef MG_64BYTE_ALIGNED
 #if defined(__GNUC__)
 #define MG_64BYTE_ALIGNED __attribute__((aligned((64U))))
 #else
 #define MG_64BYTE_ALIGNED
-#endif // compiler
-#endif // 64BYTE_ALIGNED
+#endif  // compiler
+#endif  // 64BYTE_ALIGNED
 
 #ifndef MG_ETH_RAM
 #define MG_ETH_RAM

src/l2.c

@@ -0,0 +1,121 @@
+#include "l2.h"
+#include "net.h"
+#include "net_builtin.h"
+
+#if MG_ENABLE_TCPIP
+
+// L2 API
+void mg_l2_init(enum mg_l2type type, uint8_t *addr, uint16_t *mtu,
+                uint16_t *framesize);
+uint8_t *mg_l2_header(enum mg_l2type type, enum mg_l2proto proto, uint8_t *src,
+                      uint8_t *dst, uint8_t *frame);
+size_t mg_l2_footer(enum mg_l2type type, size_t len, uint8_t *frame);
+bool mg_l2_rx(struct mg_tcpip_if *ifp, enum mg_l2proto *proto,
+              struct mg_str *pay, struct mg_str *raw);
+// TODO(): ? bool mg_l2_rx(enum mg_l2type type, struct mg_l2opts *opts, uint8_t
+// *addr, enum mg_l2proto *proto, struct mg_str *pay, struct mg_str *raw);
+uint8_t *mg_l2_getaddr(enum mg_l2type type, uint8_t *frame);
+uint8_t *mg_l2_mapip(enum mg_l2type type, enum mg_l2addrtype addrtype,
+                     struct mg_addr *ip);
+bool mg_l2_genip6(enum mg_l2type type, uint64_t *ip6, uint8_t prefix_len,
+                  uint8_t *addr);
+bool mg_l2_ip6get(enum mg_l2type type, uint8_t *addr, uint8_t *opts,
+                  uint8_t len);
+uint8_t mg_l2_ip6put(enum mg_l2type type, uint8_t *addr, uint8_t *opts);
+
+// clang-format off
+extern void mg_l2_eth_init(struct mg_l2addr *, uint16_t *, uint16_t *);
+extern uint8_t *mg_l2_eth_header(enum mg_l2proto, struct mg_l2addr *, struct mg_l2addr *, uint8_t *);
+extern size_t mg_l2_eth_footer(size_t, uint8_t *);
+extern bool mg_l2_eth_rx(struct mg_tcpip_if *, enum mg_l2proto *, struct mg_str *, struct mg_str *);
+extern struct mg_l2addr *mg_l2_eth_getaddr(uint8_t *);
+extern struct mg_l2addr *mg_l2_eth_mapip(enum mg_l2addrtype, struct mg_addr *);
+extern bool mg_l2_eth_genip6(uint64_t *, uint8_t, struct mg_l2addr *);
+extern bool mg_l2_eth_ip6get(struct mg_l2addr *, uint8_t *, uint8_t);
+extern uint8_t mg_l2_eth_ip6put(struct mg_l2addr *, uint8_t *);
+
+extern void mg_l2_ppp_init(struct mg_l2addr *, uint16_t *, uint16_t *);
+extern uint8_t *mg_l2_ppp_header(enum mg_l2proto, struct mg_l2addr *, struct mg_l2addr *, uint8_t *);
+extern size_t mg_l2_ppp_footer(size_t, uint8_t *);
+extern bool mg_l2_ppp_rx(struct mg_tcpip_if *, enum mg_l2proto *, struct mg_str *, struct mg_str *);
+extern struct mg_l2addr *mg_l2_ppp_getaddr(uint8_t *);
+extern struct mg_l2addr *mg_l2_ppp_mapip(enum mg_l2addrtype, struct mg_addr *);
+#if MG_ENABLE_IPV6
+extern bool mg_l2_ppp_genip6(uint64_t *, uint8_t, struct mg_l2addr *);
+extern bool mg_l2_ppp_ip6get(struct mg_l2addr *, uint8_t *, uint8_t);
+extern uint8_t mg_l2_ppp_ip6put(struct mg_l2addr *, uint8_t *);
+#endif
+
+typedef void (*l2_init_fn)(struct mg_l2addr *, uint16_t *, uint16_t *);
+typedef uint8_t *((*l2_header_fn)(enum mg_l2proto, struct mg_l2addr *, struct mg_l2addr *, uint8_t *));
+typedef size_t (*l2_footer_fn)(size_t, uint8_t *);
+typedef bool (*l2_rx_fn)(struct mg_tcpip_if *, enum mg_l2proto *, struct mg_str *, struct mg_str *);
+typedef struct mg_l2addr (*(*l2_getaddr_fn)(uint8_t *));
+typedef struct mg_l2addr (*(*l2_mapip_fn)(enum mg_l2addrtype, struct mg_addr *));
+#if MG_ENABLE_IPV6
+typedef bool (*l2_genip6_fn)(uint64_t *, uint8_t, struct mg_l2addr *);
+typedef bool (*l2_ip6get_fn)(struct mg_l2addr *, uint8_t *, uint8_t);
+typedef uint8_t (*l2_ip6put_fn)(struct mg_l2addr *, uint8_t *);
+#endif
+// clang-format on
+
+static const l2_init_fn l2_init[] = {mg_l2_eth_init, mg_l2_ppp_init};
+static const l2_header_fn l2_header[] = {mg_l2_eth_header, mg_l2_ppp_header};
+static const l2_footer_fn l2_footer[] = {mg_l2_eth_footer, mg_l2_ppp_footer};
+static const l2_rx_fn l2_rx[] = {mg_l2_eth_rx, mg_l2_ppp_rx};
+static const l2_getaddr_fn l2_getaddr[] = {mg_l2_eth_getaddr,
+                                           mg_l2_ppp_getaddr};
+static const l2_mapip_fn l2_mapip[] = {mg_l2_eth_mapip, mg_l2_ppp_mapip};
+#if MG_ENABLE_IPV6
+static const l2_genip6_fn l2_genip6[] = {mg_l2_eth_genip6, mg_l2_ppp_genip6};
+static const l2_ip6get_fn l2_ip6get[] = {mg_l2_eth_ip6get, mg_l2_ppp_ip6get};
+static const l2_ip6put_fn l2_ip6put[] = {mg_l2_eth_ip6put, mg_l2_ppp_ip6put};
+#endif
+
+void mg_l2_init(enum mg_l2type type, uint8_t *addr, uint16_t *mtu,
+                uint16_t *framesize) {
+  l2_init[type]((struct mg_l2addr *) addr, mtu, framesize);
+}
+
+uint8_t *mg_l2_header(enum mg_l2type type, enum mg_l2proto proto, uint8_t *src,
+                      uint8_t *dst, uint8_t *frame) {
+  return l2_header[type](proto, (struct mg_l2addr *) src,
+                         (struct mg_l2addr *) dst, frame);
+}
+
+size_t mg_l2_footer(enum mg_l2type type, size_t len, uint8_t *frame) {
+  return l2_footer[type](len, frame);
+}
+
+bool mg_l2_rx(struct mg_tcpip_if *ifp, enum mg_l2proto *proto,
+              struct mg_str *pay, struct mg_str *raw) {
+  return l2_rx[ifp->l2type](ifp, proto, pay, raw);
+}
+
+uint8_t *mg_l2_getaddr(enum mg_l2type type, uint8_t *frame) {
+  return (uint8_t *) l2_getaddr[type](frame);
+}
+
+struct mg_l2addr s_mapip;
+
+uint8_t *mg_l2_mapip(enum mg_l2type type, enum mg_l2addrtype addrtype,
+                     struct mg_addr *ip) {
+  return (uint8_t *) l2_mapip[type](addrtype, ip);
+}
+
+#if MG_ENABLE_IPV6
+bool mg_l2_genip6(enum mg_l2type type, uint64_t *ip6, uint8_t prefix_len,
+                  uint8_t *addr) {
+  return l2_genip6[type](ip6, prefix_len, (struct mg_l2addr *) addr);
+}
+
+bool mg_l2_ip6get(enum mg_l2type type, uint8_t *addr, uint8_t *opts,
+                  uint8_t len) {
+  return l2_ip6get[type]((struct mg_l2addr *) addr, opts, len);
+}
+uint8_t mg_l2_ip6put(enum mg_l2type type, uint8_t *addr, uint8_t *opts) {
+  return l2_ip6put[type]((struct mg_l2addr *) addr, opts);
+}
+#endif
+
+#endif

src/l2.h

@@ -0,0 +1,55 @@
+#pragma once
+
+#include "arch.h"
+#include "config.h"
+
+#if MG_ENABLE_TCPIP
+
+// no config defaults to 0 => Ethernet
+enum mg_l2type { MG_TCPIP_L2_ETH = 0, MG_TCPIP_L2_PPP };  // MG_TCPIP_L2_PPPoE
+
+#if defined(__DCC__)
+#pragma pack(1)
+#else
+#pragma pack(push, 1)
+#endif
+
+struct mg_l2addr {
+  union {
+    uint8_t mac[6];
+  } addr;
+};
+
+#if defined(__DCC__)
+#pragma pack(0)
+#else
+#pragma pack(pop)
+#endif
+
+#if 0
+TODO(): ?
+struct eth_opts {
+  bool enable_crc32_check;         // Do a CRC check on RX frames and strip it
+  bool enable_mac_check;           // Do a MAC check on RX frames
+};
+struct mg_l2opts {
+  union {
+    struct eth_opts eth;
+  };
+};
+#endif
+
+enum mg_l2proto {
+  MG_TCPIP_L2PROTO_IPV4 = 0,
+  MG_TCPIP_L2PROTO_IPV6,
+  MG_TCPIP_L2PROTO_ARP,
+  MG_TCPIP_L2PROTO_PPPoE_DISC,
+  MG_TCPIP_L2PROTO_PPPoE_SESS
+};
+enum mg_l2addrtype {
+  MG_TCPIP_L2ADDR_BCAST,
+  MG_TCPIP_L2ADDR_MCAST,
+  MG_TCPIP_L2ADDR_MCAST6
+};
+
+#endif

src/l2_eth.c

@@ -0,0 +1,171 @@
+#include "l2.h"
+#include "log.h"
+#include "net.h"
+#include "net_builtin.h"
+#include "printf.h"
+#include "util.h"
+
+#if MG_ENABLE_TCPIP
+
+#if defined(__DCC__)
+#pragma pack(1)
+#else
+#pragma pack(push, 1)
+#endif
+
+struct eth {
+  uint8_t dst[6];  // Destination MAC address
+  uint8_t src[6];  // Source MAC address
+  uint16_t type;   // Ethernet type
+};
+
+#if defined(__DCC__)
+#pragma pack(0)
+#else
+#pragma pack(pop)
+#endif
+
+static const uint16_t eth_types[] = {
+    // order is vital, see l2.h
+    0x800,   // IPv4
+    0x86dd,  // IPv6
+    0x806,   // ARP
+    0x8863,  // PPPoE Discovery Stage
+    0x8864   // PPPoE Session Stage
+};
+
+void mg_l2_eth_init(struct mg_l2addr *l2addr, uint16_t *mtu,
+                    uint16_t *framesize) {
+  // If MAC is not set, make a random one
+  if (l2addr->addr.mac[0] == 0 && l2addr->addr.mac[1] == 0 &&
+      l2addr->addr.mac[2] == 0 && l2addr->addr.mac[3] == 0 &&
+      l2addr->addr.mac[4] == 0 && l2addr->addr.mac[5] == 0) {
+    l2addr->addr.mac[0] = 0x02;  // Locally administered, unicast
+    mg_random(&l2addr->addr.mac[1], sizeof(l2addr->addr.mac) - 1);
+    MG_INFO(
+        ("MAC not set. Generated random: %M", mg_print_mac, l2addr->addr.mac));
+  }
+  *mtu = 1500;
+  *framesize = 1540;
+}
+
+uint8_t *mg_l2_eth_header(enum mg_l2proto proto, struct mg_l2addr *src,
+                          struct mg_l2addr *dst, uint8_t *frame) {
+  struct eth *eth = (struct eth *) frame;
+  eth->type = mg_htons(eth_types[(unsigned int) proto]);
+  memcpy(eth->src, src->addr.mac, sizeof(eth->dst));
+  memcpy(eth->dst, dst->addr.mac, sizeof(eth->dst));
+  return (uint8_t *) (eth + 1);
+}
+
+size_t mg_l2_eth_footer(size_t len, uint8_t *frame) {
+  struct eth *eth = (struct eth *) frame;
+  // nothing to do; there is no len field in Ethernet, CRC is hw-calculated
+  return len + sizeof(*eth);
+}
+
+struct mg_l2addr *mg_l2_eth_mapip(enum mg_l2addrtype addrtype,
+                                  struct mg_addr *addr);
+
+bool mg_l2_eth_rx(struct mg_tcpip_if *ifp, enum mg_l2proto *proto,
+                  struct mg_str *pay, struct mg_str *raw) {
+  struct eth *eth = (struct eth *) raw->buf;
+  uint16_t type, len;
+  unsigned int i;
+  if (raw->len < sizeof(*eth)) return false;  // Truncated - runt?
+  len = (uint16_t) raw->len;
+  if (ifp->enable_mac_check &&
+      memcmp(eth->dst, ifp->mac, sizeof(eth->dst)) != 0 &&
+      memcmp(eth->dst, mg_l2_eth_mapip(MG_TCPIP_L2ADDR_BCAST, NULL),
+             sizeof(eth->dst)) != 0)
+    return false;  // TODO(): add multicast addresses
+  if (ifp->enable_crc32_check && len > sizeof(*eth) + 4) {
+    uint32_t crc;
+    len -= 4;  // TODO(scaprile): check on bigendian
+    crc = mg_crc32(0, (const char *) raw->buf, len);
+    if (memcmp((void *) ((size_t) raw->buf + len), &crc, sizeof(crc)))
+      return false;
+  }
+  pay->buf = (char *) (eth + 1);
+  pay->len = len;
+
+  type = mg_htons(eth->type);
+  for (i = 0; i < sizeof(eth_types) / sizeof(uint16_t); i++) {
+    if (type == eth_types[i]) break;
+  }
+  if (i == sizeof(eth_types)) {
+    MG_DEBUG(("Unknown eth type %x", type));
+    if (mg_log_level >= MG_LL_VERBOSE)
+      mg_hexdump(raw->buf, raw->len >= 32 ? 32 : raw->len);
+    return false;
+  }
+  *proto = (enum mg_l2proto) i;
+  return true;
+}
+
+struct mg_l2addr *mg_l2_eth_getaddr(uint8_t *frame) {
+  struct eth *eth = (struct eth *) frame;
+  return (struct mg_l2addr *) &eth->src;
+}
+
+extern struct mg_l2addr s_mapip;
+
+struct mg_l2addr *mg_l2_eth_mapip(enum mg_l2addrtype addrtype,
+                                  struct mg_addr *addr) {
+  switch (addrtype) {
+    case MG_TCPIP_L2ADDR_BCAST:
+      memset(s_mapip.addr.mac, 0xff, sizeof(s_mapip.addr.mac));
+      break;
+    case MG_TCPIP_L2ADDR_MCAST: {
+      uint8_t *ip = (uint8_t *) &addr->addr.ip4;
+      // IP multicast group MAC, RFC-1112 6.4
+      s_mapip.addr.mac[0] = 0x01, s_mapip.addr.mac[1] = 0x00,
+      s_mapip.addr.mac[2] = 0x5E;
+      s_mapip.addr.mac[3] = ip[1] & 0x7F;  // 23 LSb
+      s_mapip.addr.mac[4] = ip[2];
+      s_mapip.addr.mac[5] = ip[3];
+      break;
+    }
+    case MG_TCPIP_L2ADDR_MCAST6: {
+      // IPv6 multicast address mapping, RFC-2464 7
+      uint8_t *ip = (uint8_t *) &addr->addr.ip6;
+      s_mapip.addr.mac[0] = 0x33, s_mapip.addr.mac[1] = 0x33;
+      s_mapip.addr.mac[2] = ip[12], s_mapip.addr.mac[3] = ip[13],
+      s_mapip.addr.mac[4] = ip[14], s_mapip.addr.mac[5] = ip[15];
+      break;
+    }
+  }
+  return &s_mapip;
+}
+
+#if MG_ENABLE_IPV6
+static void meui64(uint8_t *addr, uint8_t *mac) {
+  *addr++ = *mac++ ^ (uint8_t) 0x02, *addr++ = *mac++, *addr++ = *mac++;
+  *addr++ = 0xff, *addr++ = 0xfe;
+  *addr++ = *mac++, *addr++ = *mac++, *addr = *mac;
+}
+
+bool mg_l2_eth_genip6(uint64_t *ip6, uint8_t prefix_len,
+                      struct mg_l2addr *l2addr) {
+  if (prefix_len > 64) {
+    MG_ERROR(("Prefix length > 64, UNSUPPORTED"));
+    return false;
+  }
+  ip6[0] = 0;
+  meui64(((uint8_t *) &ip6[1]), l2addr->addr.mac);  // RFC-4291 2.5.4, 2.5.1
+  return true;
+}
+
+bool mg_l2_eth_ip6get(struct mg_l2addr *l2addr, uint8_t *opts, uint8_t len) {
+  if (len != 1) return false;
+  memcpy(l2addr->addr.mac, opts, 6);
+  return true;
+}
+
+uint8_t mg_l2_eth_ip6put(struct mg_l2addr *l2addr, uint8_t *opts) {
+  memcpy(opts, l2addr->addr.mac, 6);
+  return 1;
+}
+#endif
+
+#endif

src/l2_ppp.c

@@ -0,0 +1,115 @@
+#include "l2.h"
+#include "log.h"
+#include "net.h"
+#include "net_builtin.h"
+#include "printf.h"
+#include "util.h"
+
+#if MG_ENABLE_TCPIP
+
+#if defined(__DCC__)
+#pragma pack(1)
+#else
+#pragma pack(push, 1)
+#endif
+
+struct ppp {  // RFC-1662
+  uint8_t addr, ctrl;
+  uint16_t proto;
+};
+
+struct lcp {  // RFC-1661
+  uint8_t code, id, len[2];
+};
+
+struct ipcp { // RFC-1332
+  uint8_t code;
+};
+
+struct ipv6cp { // RFC-5072
+  uint8_t code;
+};
+
+#if defined(__DCC__)
+#pragma pack(0)
+#else
+#pragma pack(pop)
+#endif
+
+
+void mg_l2_ppp_init(struct mg_l2addr *addr, uint16_t *mtu,
+                    uint16_t *framesize) {
+  (void) addr;
+  *mtu = 1500;        // 1492 for PPPoE
+  *framesize = 1540;  // *** TODO(scaprile): actual value, check for PPPoE too
+}
+
+uint8_t *mg_l2_ppp_header(enum mg_l2proto proto, struct mg_l2addr *src,
+                          struct mg_l2addr *dst, uint8_t *frame) {
+  (void) src;
+  (void) dst;
+  (void) proto;
+  return frame;
+}
+
+size_t mg_l2_ppp_footer(size_t len, uint8_t *frame) {
+  (void) frame;
+  return len;
+}
+
+bool mg_l2_ppp_rx(struct mg_tcpip_if *ifp, enum mg_l2proto *proto,
+                  struct mg_str *pay, struct mg_str *raw) {
+#if 0
+if (ppp->addr == MG_PPP_ADDR && ppp->ctrl == MG_PPP_CTRL) {
+  code = ntohs(ppp->proto);
+  payload = (uint8_t *) (ppp + 1);
+} else { // Address-and-Control-Field-Compressed PPP header
+  uint16_t *cppp = (uint16_t *) ppp;
+  code = ntohs(*cppp);
+  payload = (uint8_t *) (cppp + 1);
+}
+#endif
+  *pay = *raw;
+  *proto = MG_TCPIP_L2PROTO_IPV4;
+  (void) ifp;
+  return true;
+}
+
+struct mg_l2addr *mg_l2_ppp_getaddr(uint8_t *frame) {
+  (void) frame;
+  return &s_mapip;  // bogus
+}
+
+extern struct mg_l2addr s_mapip;
+
+struct mg_l2addr *mg_l2_ppp_mapip(enum mg_l2addrtype addrtype,
+                                  struct mg_addr *addr) {
+  (void) addrtype;
+  (void) addr;
+  return &s_mapip;  // bogus
+}
+
+#if MG_ENABLE_IPV6
+bool mg_l2_ppp_genip6(uint64_t *ip6, uint8_t prefix_len,
+                      struct mg_l2addr *addr) {
+  (void) ip6;
+  (void) prefix_len;
+  (void) addr;
+  return false;
+}
+
+bool mg_l2_ppp_ip6get(struct mg_l2addr *addr, uint8_t *opts, uint8_t len) {
+  (void) addr;
+  (void) opts;
+  (void) len;
+  return false;
+}
+
+uint8_t mg_l2_ppp_ip6put(struct mg_l2addr *addr, uint8_t *opts) {
+  (void) addr;
+  (void) opts;
+  return 0;
+}
+#endif
+
+#endif

src/net_builtin.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include "arch.h"
+#include "l2.h"
 #include "net.h"
 #include "queue.h"
 #include "str.h"
@@ -20,29 +21,32 @@ typedef void (*mg_tcpip_event_handler_t)(struct mg_tcpip_if *ifp, int ev,
                                          void *ev_data);
 
 enum {
-  MG_TCPIP_EV_ST_CHG,           // state change                   uint8_t * (&ifp->state)
-  MG_TCPIP_EV_DHCP_DNS,         // DHCP DNS assignment            uint32_t *ipaddr
-  MG_TCPIP_EV_DHCP_SNTP,        // DHCP SNTP assignment           uint32_t *ipaddr
-  MG_TCPIP_EV_ARP,              // Got ARP packet                 struct mg_str *
-  MG_TCPIP_EV_TIMER_1S,         // 1 second timer                 NULL
-  MG_TCPIP_EV_WIFI_SCAN_RESULT, // Wi-Fi scan results             struct mg_wifi_scan_bss_data *
-  MG_TCPIP_EV_WIFI_SCAN_END,    // Wi-Fi scan has finished        NULL
-  MG_TCPIP_EV_WIFI_CONNECT_ERR, // Wi-Fi connect has failed       driver and chip specific
-  MG_TCPIP_EV_DRIVER,           // Driver event                   driver specific
-  MG_TCPIP_EV_ST6_CHG,          // state6 change                  uint8_t * (&ifp->state6)
-  MG_TCPIP_EV_USER              // Starting ID for user events
+  MG_TCPIP_EV_ST_CHG,  // state change                   uint8_t * (&ifp->state)
+  MG_TCPIP_EV_DHCP_DNS,   // DHCP DNS assignment            uint32_t *ipaddr
+  MG_TCPIP_EV_DHCP_SNTP,  // DHCP SNTP assignment           uint32_t *ipaddr
+  MG_TCPIP_EV_ARP,        // Got ARP packet                 struct mg_str *
+  MG_TCPIP_EV_TIMER_1S,   // 1 second timer                 NULL
+  MG_TCPIP_EV_WIFI_SCAN_RESULT,  // Wi-Fi scan results             struct
+                                 // mg_wifi_scan_bss_data *
+  MG_TCPIP_EV_WIFI_SCAN_END,     // Wi-Fi scan has finished        NULL
+  MG_TCPIP_EV_WIFI_CONNECT_ERR,  // Wi-Fi connect has failed       driver and
+                                 // chip specific
+  MG_TCPIP_EV_DRIVER,   // Driver event                   driver specific
+  MG_TCPIP_EV_ST6_CHG,  // state6 change                  uint8_t *
+                        // (&ifp->state6)
+  MG_TCPIP_EV_USER      // Starting ID for user events
 };
 
 // Network interface
 struct mg_tcpip_if {
-  uint8_t mac[6];                  // MAC address. Must be set to a valid MAC
-  uint32_t ip, mask, gw;           // IP address, mask, default gateway
-  struct mg_str tx;                // Output (TX) buffer
-  bool enable_dhcp_client;         // Enable DCHP client
-  bool enable_dhcp_server;         // Enable DCHP server
-  bool enable_get_gateway;         // DCHP server sets client as gateway
-  bool enable_req_dns;             // DCHP client requests DNS server
-  bool enable_req_sntp;            // DCHP client requests SNTP server
+  uint8_t mac[sizeof(struct mg_l2addr)];  // hw address. Set to a valid addr
+  uint32_t ip, mask, gw;                  // IP address, mask, default gateway
+  struct mg_str tx;                       // Output (TX) buffer
+  bool enable_dhcp_client;                // Enable DCHP client
+  bool enable_dhcp_server;                // Enable DCHP server
+  bool enable_get_gateway;                // DCHP server sets client as gateway
+  bool enable_req_dns;                    // DCHP client requests DNS server
+  bool enable_req_sntp;                   // DCHP client requests SNTP server
   bool enable_crc32_check;         // Do a CRC check on RX frames and strip it
   bool enable_mac_check;           // Do a MAC check on RX frames
   bool update_mac_hash_table;      // Signal drivers to update MAC controller
@@ -53,21 +57,22 @@ struct mg_tcpip_if {
   struct mg_mgr *mgr;              // Mongoose event manager
   struct mg_queue recv_queue;      // Receive queue
   char dhcp_name[MG_TCPIP_DHCPNAME_SIZE];  // Name for DHCP, "mip" if unset
-  uint16_t mtu;                            // Interface MTU
-#define MG_TCPIP_MTU_DEFAULT 1500
+  uint16_t mtu;                            // Interface link payload
+  uint16_t framesize;                      // Interface frame max length
 #if MG_ENABLE_IPV6
-  uint64_t ip6ll[2], ip6[2];       // IPv6 link-local and global addresses
-  uint8_t prefix[8];               // IPv6 global address prefix
-  uint8_t prefix_len;              // Prefix length
-  uint64_t gw6[2];                 // Default gateway
-  bool enable_slaac;               // Enable IPv6 address autoconfiguration
-  bool enable_dhcp6_client;        // Enable DCHPv6 client
+  uint64_t ip6ll[2], ip6[2];  // IPv6 link-local and global addresses,
+  uint8_t prefix[8];          // prefix,
+  uint8_t prefix_len;         // prefix length,
+  uint64_t gw6[2];            // default gateway.
+  bool enable_slaac;          // Enable IPv6 address autoconfiguration
+  bool enable_dhcp6_client;   // Enable DCHPv6 client TODO()
 #endif
 
   // Internal state, user can use it but should not change it
-  uint8_t gwmac[6];             // Router's MAC
-  char *dns4_url;               // DNS server URL
-  uint64_t now;                 // Current time
+  uint8_t gwmac[sizeof(struct mg_l2addr)];  // Router's hw address
+  enum mg_l2type l2type;                    // Ethernet, PPP, etc.
+  char *dns4_url;                           // DNS server URL
+  uint64_t now;                             // Current time
   uint64_t timer_1000ms;        // 1000 ms timer: for DHCP and link state
   uint64_t lease_expire;        // Lease expiration time, in ms
   uint16_t eport;               // Next ephemeral port
@@ -83,11 +88,12 @@ struct mg_tcpip_if {
 #define MG_TCPIP_STATE_READY 4  // Interface has fully come up, ready to work
   bool gw_ready;                // We've got a hw address for the router
 #if MG_ENABLE_IPV6
-  uint8_t gw6mac[6];             // IPv6 Router's MAC
-  uint8_t state6;                // Current IPv6 state
-  bool gw6_ready;                // We've got a hw address for the IPv6 router
+  uint8_t gw6mac[sizeof(struct mg_l2addr)];  // IPV6 Router's hw address
+  uint8_t state6;                            // Current IPv6 state
+  bool gw6_ready;  // We've got a hw address for the IPv6 router
 #endif
 };
+
 void mg_tcpip_init(struct mg_mgr *, struct mg_tcpip_if *);
 void mg_tcpip_free(struct mg_tcpip_if *);
 void mg_tcpip_qwrite(void *buf, size_t len, struct mg_tcpip_if *ifp);
@@ -119,39 +125,38 @@ struct mg_tcpip_spi {
   uint8_t (*txn)(void *, uint8_t);  // SPI transaction: write 1 byte, read reply
 };
 
-
 // Alignment and memory section requirements
 #ifndef MG_8BYTE_ALIGNED
 #if defined(__GNUC__)
 #define MG_8BYTE_ALIGNED __attribute__((aligned((8U))))
 #else
 #define MG_8BYTE_ALIGNED
-#endif // compiler
-#endif // 8BYTE_ALIGNED
+#endif  // compiler
+#endif  // 8BYTE_ALIGNED
 
 #ifndef MG_16BYTE_ALIGNED
 #if defined(__GNUC__)
 #define MG_16BYTE_ALIGNED __attribute__((aligned((16U))))
 #else
 #define MG_16BYTE_ALIGNED
-#endif // compiler
-#endif // 16BYTE_ALIGNED
+#endif  // compiler
+#endif  // 16BYTE_ALIGNED
 
 #ifndef MG_32BYTE_ALIGNED
 #if defined(__GNUC__)
 #define MG_32BYTE_ALIGNED __attribute__((aligned((32U))))
 #else
 #define MG_32BYTE_ALIGNED
-#endif // compiler
-#endif // 32BYTE_ALIGNED
+#endif  // compiler
+#endif  // 32BYTE_ALIGNED
 
 #ifndef MG_64BYTE_ALIGNED
 #if defined(__GNUC__)
 #define MG_64BYTE_ALIGNED __attribute__((aligned((64U))))
 #else
 #define MG_64BYTE_ALIGNED
-#endif // compiler
-#endif // 64BYTE_ALIGNED
+#endif  // compiler
+#endif  // 64BYTE_ALIGNED
 
 #ifndef MG_ETH_RAM
 #define MG_ETH_RAM

src/printf.c

@@ -107,12 +107,27 @@ size_t mg_print_ip_port(void (*out)(char, void *), void *arg, va_list *ap) {
   return mg_xprintf(out, arg, "%M:%hu", mg_print_ip, a, mg_ntohs(a->port));
 }
 
-size_t mg_print_mac(void (*out)(char, void *), void *arg, va_list *ap) {
-  uint8_t *p = va_arg(*ap, uint8_t *);
+static size_t print_mac(void (*out)(char, void *), void *arg, uint8_t *p) {
   return mg_xprintf(out, arg, "%02x:%02x:%02x:%02x:%02x:%02x", p[0], p[1], p[2],
                     p[3], p[4], p[5]);
 }
 
+size_t mg_print_mac(void (*out)(char, void *), void *arg, va_list *ap) {
+  uint8_t *p = va_arg(*ap, uint8_t *);
+  return print_mac(out, arg, p);
+}
+
+#if MG_ENABLE_TCPIP
+size_t mg_print_l2addr(void (*out)(char, void *), void *arg, va_list *ap) {
+  enum mg_l2type type = (enum mg_l2type) va_arg(*ap, int);
+  if (type == MG_TCPIP_L2_ETH) {
+    uint8_t *p = va_arg(*ap, uint8_t *);
+    return print_mac(out, arg, p);
+  }
+  return 0;
+}
+#endif
+
 static char mg_esc(int c, bool esc) {
   const char *p, *esc1 = "\b\f\n\r\t\\\"", *esc2 = "bfnrt\\\"";
   for (p = esc ? esc1 : esc2; *p != '\0'; p++) {

src/printf.h

@@ -20,6 +20,7 @@ size_t mg_print_ip_port(void (*out)(char, void *), void *arg, va_list *ap);
 size_t mg_print_ip4(void (*out)(char, void *), void *arg, va_list *ap);
 size_t mg_print_ip6(void (*out)(char, void *), void *arg, va_list *ap);
 size_t mg_print_mac(void (*out)(char, void *), void *arg, va_list *ap);
+size_t mg_print_l2addr(void (*out)(char, void *), void *arg, va_list *ap);
 
 // Various output functions
 void mg_pfn_iobuf(char ch, void *param);  // param: struct mg_iobuf *

test/Makefile

@@ -230,7 +230,7 @@ mongoose.c: Makefile $(wildcard ../src/*.c) $(wildcard ../src/drivers/*.c)
 	cd .. && (export LC_ALL=C ; cat src/license.h; echo; echo '#include "mongoose.h"' ; (for F in src/*.c src/drivers/*.c ; do echo; echo '#ifdef MG_ENABLE_LINES'; echo "#line 1 \"$$F\""; echo '#endif'; cat $$F | sed -e 's,#include ".*,,'; done))> $@
 
 mongoose.h: $(HDRS) Makefile
-	cd .. && (cat src/license.h; echo; echo '#ifndef MONGOOSE_H'; echo '#define MONGOOSE_H'; echo; cat src/version.h ; echo; echo '#ifdef __cplusplus'; echo 'extern "C" {'; echo '#endif'; cat src/arch.h src/arch_*.h src/net_ft.h src/net_lwip.h src/net_rl.h src/config.h src/profile.h src/str.h src/queue.h src/fmt.h src/printf.h src/log.h src/timer.h src/fs.h src/util.h src/url.h src/iobuf.h src/base64.h src/md5.h src/sha1.h src/sha256.h src/event.h src/net.h src/http.h src/ssi.h src/tls.h src/tls_x25519.h src/tls_aes128.h src/tls_uecc.h src/tls_chacha20.h src/tls_rsa.h src/tls_mbed.h src/tls_openssl.h src/ws.h src/sntp.h src/mqtt.h src/dns.h src/json.h src/rpc.h src/ota.h src/flash.h src/wifi.h src/net_builtin.h src/drivers/*.h | sed -e '/keep/! s,#include ".*,,' -e 's,^#pragma once,,'; echo; echo '#ifdef __cplusplus'; echo '}'; echo '#endif'; echo '#endif  // MONGOOSE_H')> $@
+	cd .. && (cat src/license.h; echo; echo '#ifndef MONGOOSE_H'; echo '#define MONGOOSE_H'; echo; cat src/version.h ; echo; echo '#ifdef __cplusplus'; echo 'extern "C" {'; echo '#endif'; cat src/arch.h src/arch_*.h src/net_ft.h src/net_lwip.h src/net_rl.h src/config.h src/profile.h src/str.h src/queue.h src/fmt.h src/printf.h src/log.h src/timer.h src/fs.h src/util.h src/url.h src/iobuf.h src/base64.h src/md5.h src/sha1.h src/sha256.h src/event.h src/net.h src/http.h src/ssi.h src/tls.h src/tls_x25519.h src/tls_aes128.h src/tls_uecc.h src/tls_chacha20.h src/tls_rsa.h src/tls_mbed.h src/tls_openssl.h src/ws.h src/sntp.h src/mqtt.h src/dns.h src/json.h src/rpc.h src/ota.h src/flash.h src/wifi.h src/l2.h src/net_builtin.h src/drivers/*.h | sed -e '/keep/! s,#include ".*,,' -e 's,^#pragma once,,'; echo; echo '#ifdef __cplusplus'; echo '}'; echo '#endif'; echo '#endif  // MONGOOSE_H')> $@
 
 
 clean: clean_tutorials clean_tutorials_embedded