mongoose/examples/mip-tap/main.c
2022-09-12 10:52:23 -03:00

92 lines
2.6 KiB
C

// Copyright (c) 2022 Cesanta Software Limited
// All rights reserved
//
// example using MIP and a TUN/TAP interface
#include "mongoose.h"
#include <linux/if.h>
#include <linux/if_tun.h>
#include <sys/ioctl.h>
static int s_signo;
void signal_handler(int signo) {
s_signo = signo;
}
static size_t tap_tx(const void *buf, size_t len, void *userdata) {
ssize_t res = write((int) userdata, buf, len);
if (res < 0) {
MG_ERROR(("tap_tx failed: %d", errno));
return 0;
}
return (size_t) res;
}
static bool tap_up(void *userdata) {
return userdata ? true : false;
}
static size_t tap_rx(void *buf, size_t len, void *userdata) {
ssize_t received = read((int) userdata, buf, len);
usleep(1); // This is to avoid 100% CPU
if (received < 0) return 0;
return (size_t) received;
}
int main(int argc, char *argv[]) {
const char *iface = "tap0"; // Network iface
const char *mac = "00:00:01:02:03:77"; // MAC address
// 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], "-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
int fd = open("/dev/net/tun", O_RDWR);
struct ifreq ifr;
memset(&ifr, 0, sizeof(ifr));
strncpy(ifr.ifr_name, iface, IFNAMSIZ);
ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
if (ioctl(fd, TUNSETIFF, (void *) &ifr) < 0) {
MG_ERROR(("Failed to setup TAP interface: %s", ifr.ifr_name));
return EXIT_FAILURE;
}
fcntl(fd, F_SETFL, fcntl(fd, F_GETFL, 0) | O_NONBLOCK); // Non-blocking mode
MG_INFO(("Opened TAP 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_cfg c = {.ip = 0, .mask = 0, .gw = 0};
sscanf(mac, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx", &c.mac[0], &c.mac[1], &c.mac[2],
&c.mac[3], &c.mac[4], &c.mac[5]);
struct mip_driver driver = {.tx = tap_tx, .up = tap_up, .rx = tap_rx};
mip_init(&mgr, &c, &driver, (void *) fd);
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);
close(fd);
printf("Exiting on signal %d\n", s_signo);
return 0;
}