mongoose/examples/mip-pcap/main.c
2022-11-09 19:25:40 +00:00

116 lines
3.5 KiB
C

// 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, void *userdata) {
int res = pcap_inject((pcap_t *) userdata, buf, len);
if (res == PCAP_ERROR) {
MG_ERROR(("pcap_inject: %d", res));
}
return res == PCAP_ERROR ? 0 : len;
}
static bool pcap_up(void *userdata) {
return userdata ? true : false;
}
static size_t pcap_rx(void *buf, size_t len, void *userdata) {
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 *) userdata, &hdr, &pkt) == 1) { // Yes, read
received = hdr->len < len ? hdr->len : len;
memcpy(buf, pkt, received);
}
return received;
}
int main(int argc, char *argv[]) {
const char *iface = "lo0"; // Network iface
const char *mac = "00:00:01:02:03:77"; // 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
struct mip_driver driver = {.tx = pcap_tx, .up = pcap_up, .rx = pcap_rx};
struct mip_if mif = {.use_dhcp = true, .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]);
mip_init(&mgr, &mif);
MG_INFO(("Init done, starting main loop"));
extern void device_dashboard_fn(struct mg_connection *, int, void *, void *);
mg_http_listen(&mgr, "http://0.0.0.0:8000", device_dashboard_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;
}