move to new skeleton

tutorials/tcpip/pcap-driver/main.c

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+// Copyright (c) 2022 Cesanta Software Limited
+// All rights reserved
+//
+// SNTP example using MIP and pcap driver
+
+#include <pcap.h>
+#include "mongoose.h"
+
+#define MQTT_URL "mqtt://broker.hivemq.com:1883"  // MQTT broker to connect to
+#define MQTT_TOPIC "t/123"                        // Topic to subscribe to
+
+#if MG_ARCH == MG_ARCH_WIN32
+#define usleep(x) Sleep((x) / 1000)
+#endif
+
+static int s_signo;
+void signal_handler(int signo) {
+  s_signo = signo;
+}
+
+static size_t pcap_tx(const void *buf, size_t len, struct mg_tcpip_if *ifp) {
+  int res = pcap_inject((pcap_t *) ifp->driver_data, buf, len);
+  if (res == PCAP_ERROR) {
+    MG_ERROR(("pcap_inject: %d", res));
+  }
+  return res == PCAP_ERROR ? 0 : len;
+}
+
+static bool pcap_up(struct mg_tcpip_if *ifp) {
+  return ifp->driver_data ? true : false;
+}
+
+static size_t pcap_rx(void *buf, size_t len, struct mg_tcpip_if *ifp) {
+  size_t received = 0;
+  struct pcap_pkthdr *hdr = NULL;
+  const unsigned char *pkt = NULL;
+  usleep(1000);  // Sleep 1 millisecond. This is to avoid 100% CPU
+  if (pcap_next_ex((pcap_t *) ifp->driver_data, &hdr, &pkt) == 1) {
+    received = hdr->len < len ? hdr->len : len;
+    memcpy(buf, pkt, received);
+  }
+  return received;
+}
+
+static void fn2(struct mg_connection *c, int ev, void *ev_data) {
+  if (ev == MG_EV_HTTP_MSG) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    MG_DEBUG(("Got response (%d) %.*s...", (int) hm->message.len, 12,
+              hm->message.buf));
+    c->is_draining = 1;
+  } else if (ev == MG_EV_CONNECT) {
+    mg_printf(c, "GET %s HTTP/1.1\r\n\r\n", mg_url_uri((char *) c->fn_data));
+  } else if (ev == MG_EV_CLOSE) {
+    free(c->fn_data);
+  }
+}
+
+static void fn(struct mg_connection *c, int ev, void *ev_data) {
+  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, "$.level", MG_LL_DEBUG);
+      mg_log_set(level);
+      mg_http_reply(c, 200, "", "Debug level set to %d\n", level);
+    } else if (mg_match(hm->uri, mg_str("/api/url"), NULL)) {
+      char *url = mg_json_get_str(hm->body, "$.url");
+      if (url == NULL) {
+        mg_http_reply(c, 200, NULL, "no url, rl %d\r\n", (int) c->recv.len);
+      } else {
+        mg_http_connect(c->mgr, url, fn2, url);
+        mg_http_reply(c, 200, NULL, "ok\r\n");
+      }
+    } else {
+      mg_http_reply(c, 200, NULL, "%.*s\r\n", (int) hm->message.len,
+                    hm->message.buf);
+    }
+  }
+  (void) ev_data;
+}
+
+int main(int argc, char *argv[]) {
+  const char *iface = "lo0";              // Network iface
+  const char *mac = "02:00:01:02:03:77";  // MAC address
+  const char *bpf = NULL;  // "host x.x.x.x or ether host ff:ff:ff:ff:ff:ff";
+  char errbuf[PCAP_ERRBUF_SIZE] = "";
+
+  // Parse options
+  for (int i = 1; i < argc; i++) {
+    if (strcmp(argv[i], "-i") == 0 && i + 1 < argc) {
+      iface = argv[++i];
+    } else if (strcmp(argv[i], "-mac") == 0 && i + 1 < argc) {
+      mac = argv[++i];
+    } else if (strcmp(argv[i], "-bpf") == 0 && i + 1 < argc) {
+      bpf = argv[++i];
+    } else if (strcmp(argv[i], "-v") == 0 && i + 1 < argc) {
+      mg_log_set(atoi(argv[++i]));
+    } else {
+      MG_ERROR(("unknown option %s", argv[i]));
+      return EXIT_FAILURE;
+    }
+  }
+
+  // Open network interface
+  pcap_t *ph = pcap_open_live(iface, 0xffff, 1, 1, errbuf);
+  if (ph == NULL) {
+    pcap_if_t *devs, *d;
+    MG_ERROR(("Failed to open interface %s. Available interfaces:", iface));
+    if (pcap_findalldevs(&devs, errbuf) == 0) {
+      for (d = devs; d != NULL; d = d->next) {
+        MG_ERROR(("%s (%s)", d->name, d->description ? d->description : ""));
+      }
+      pcap_freealldevs(devs);
+    }
+    return EXIT_FAILURE;
+  }
+  pcap_setnonblock(ph, 1, errbuf);
+  pcap_setdirection(ph, PCAP_D_IN);
+
+  // Apply BPF to reduce noise. Let in only broadcasts and our own traffic
+  if (bpf != NULL) {
+    struct bpf_program bpfp;
+    if (pcap_compile(ph, &bpfp, bpf, 1, 0)) MG_ERROR(("BPF compile failed\n"));
+    pcap_setfilter(ph, &bpfp);
+    pcap_freecode(&bpfp);
+  }
+
+  MG_INFO(("Opened interface %s", iface));
+  signal(SIGINT, signal_handler);
+  signal(SIGTERM, signal_handler);
+
+  struct mg_mgr mgr;        // Event manager
+  mg_mgr_init(&mgr);        // Initialise event manager
+  mg_log_set(MG_LL_DEBUG);  // Set log level
+
+  struct mg_tcpip_driver driver = {.tx = pcap_tx, .up = pcap_up, .rx = pcap_rx};
+  struct mg_tcpip_if mif = {.driver = &driver, .driver_data = ph};
+  sscanf(mac, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx", &mif.mac[0], &mif.mac[1],
+         &mif.mac[2], &mif.mac[3], &mif.mac[4], &mif.mac[5]);
+  mg_tcpip_init(&mgr, &mif);
+  MG_INFO(("Init done, starting main loop"));
+  mg_http_listen(&mgr, "http://0.0.0.0:8000", fn, &mgr);
+
+  while (s_signo == 0) mg_mgr_poll(&mgr, 100);  // Infinite event loop
+
+  mg_mgr_free(&mgr);
+  pcap_close(ph);
+  printf("Exiting on signal %d\n", s_signo);
+
+  return 0;
+}