#include <netinet/in.h>
#include <arpa/inet.h>
#include <errno.h>
+#include <net/if.h>
+#include <linux/if_tun.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <sys/poll.h>
+#include <syslog.h>
+#include <signal.h>
#include "utils.h"
+static int quit = 0;
+static unsigned char macaddr[6];
+
static void usage(FILE *out)
{
- fprintf(out, "usage: mctap [-h] MCASTGROUP PORT\n");
+ fprintf(out, "usage: mctap [-hdpk] [-P PIDFILE] [-D TAPNAME] MCASTGROUP PORT\n");
}
-static char *formataddress(struct sockaddr *arg, socklen_t arglen)
+static __attribute__ ((unused)) char *formataddress(struct sockaddr *arg, socklen_t arglen)
{
struct sockaddr_in *ipv4;
struct sockaddr_in6 *ipv6;
switch(arg->sa_family)
{
case AF_UNIX:
- ret = strdup("Unix socket");
+ ret = sstrdup("Unix socket");
break;
case AF_INET:
ipv4 = (struct sockaddr_in *)arg;
static int mkmcastsk4(struct in_addr group, int port)
{
int fd;
+ int soval;
struct sockaddr_in nm;
struct ip_mreqn mreq;
fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
+ soval = 1;
+ if(setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &soval, sizeof(soval)))
+ return(-1);
memset(&nm, 0, sizeof(nm));
nm.sin_family = AF_INET;
nm.sin_port = htons(port);
return(-1);
memset(&mreq, 0, sizeof(mreq));
mreq.imr_multiaddr = group;
- if(setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)))
+ if(setsockopt(fd, SOL_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)))
+ return(-1);
+ soval = 1;
+ if(setsockopt(fd, SOL_IP, IP_MULTICAST_LOOP, &soval, sizeof(soval)))
return(-1);
return(fd);
}
-static void test(int fd)
+static __attribute__ ((unused)) void test(int fd)
{
char buf[65536];
- int ret;
- struct sockaddr_storage nm;
- socklen_t nmlen;
+ int i, ret;
+ struct pollfd pfd;
while(1) {
- nmlen = sizeof(nm);
- ret = recvfrom(fd, buf, sizeof(buf), 0, (struct sockaddr *)&nm, &nmlen);
+ pfd.fd = fd;
+ pfd.events = POLLIN;
+ ret = poll(&pfd, 1, -1);
if(ret < 0) {
- fprintf(stderr, "mctap: recvfrom: %s\n", strerror(ret));
+ fprintf(stderr, "mctap: poll: %s\n", strerror(errno));
exit(1);
}
- printf("%s %i:\n", formataddress((struct sockaddr *)&nm, nmlen), ret);
+ if(pfd.revents) {
+ ret = read(fd, buf, sizeof(buf));
+ if(ret < 0) {
+ fprintf(stderr, "mctap: read: %s\n", strerror(errno));
+ exit(1);
+ }
+ for(i = 0; i < ret; i++) {
+ printf("%02x ", (unsigned char)buf[i]);
+ if(i % 20 == 19)
+ putchar(10);
+ }
+ putchar(10);
+ }
+ }
+}
+
+static void bridge(int sock, int tap, struct sockaddr *dst, socklen_t dstlen)
+{
+ char buf[65536];
+ int ret;
+ struct pollfd pfds[2];
+ struct tun_pi pi;
+
+ fcntl(sock, F_SETFL, fcntl(sock, F_GETFL) | O_NONBLOCK);
+ fcntl(tap, F_SETFL, fcntl(tap, F_GETFL) | O_NONBLOCK);
+ while(!quit) {
+ pfds[0].fd = sock;
+ pfds[0].events = POLLIN;
+ pfds[1].fd = tap;
+ pfds[1].events = POLLIN;
+ ret = poll(pfds, 2, -1);
+ if(ret < 0) {
+ if(errno != EINTR) {
+ syslog(LOG_ERR, "mctap: poll: %s", strerror(errno));
+ exit(1);
+ }
+ continue;
+ }
+ if(pfds[0].revents) {
+ ret = read(sock, buf, sizeof(buf));
+ if(ret < 0) {
+ if((errno != EINTR) && (errno != EAGAIN)) {
+ syslog(LOG_ERR, "mctap: mcast packet: %s", strerror(errno));
+ exit(1);
+ }
+ } else {
+ if(sizeof(buf) - ret < sizeof(pi)) {
+ /* Drop */
+ } else if((ret < 12) || !memcmp(macaddr, buf + 6, 6)) {
+ /* Drop looped back */
+ } else {
+ memmove(buf + sizeof(pi), buf, ret);
+ pi.flags = 0;
+ pi.proto = 0;
+ memcpy(buf, &pi, sizeof(pi));
+ write(tap, buf, sizeof(pi) + ret);
+ }
+ }
+ }
+ if(pfds[1].revents) {
+ ret = read(tap, buf, sizeof(buf));
+ if(ret < 0) {
+ if((errno != EINTR) && (errno != EAGAIN)) {
+ syslog(LOG_ERR, "mctap: mcast packet: %s", strerror(errno));
+ exit(1);
+ }
+ } else {
+ if(ret < sizeof(pi)) {
+ /* Drop */
+ } else {
+ memcpy(&pi, buf, sizeof(pi));
+ if(pi.flags & TUN_PKT_STRIP) {
+ /* Drop */
+ } else {
+ sendto(sock, buf + sizeof(pi), ret - sizeof(pi), 0, dst, dstlen);
+ }
+ }
+ }
+ }
+ }
+}
+
+static int maketap(char *name)
+{
+ int fd;
+ struct ifreq rb;
+
+ if((fd = open("/dev/net/tun", O_RDWR)) < 0)
+ return(-1);
+ memset(&rb, 0, sizeof(rb));
+ rb.ifr_flags = IFF_TAP;
+ strncpy(rb.ifr_name, name, IFNAMSIZ);
+ if(ioctl(fd, TUNSETIFF, &rb))
+ return(-1);
+ if(ioctl(fd, SIOCGIFHWADDR, &rb))
+ return(-1);
+ memcpy(macaddr, rb.ifr_hwaddr.sa_data, 6);
+ return(fd);
+}
+
+static void sighand(int sig)
+{
+ switch(sig) {
+ case SIGINT:
+ case SIGTERM:
+ quit = 1;
+ break;
+ case SIGHUP:
+ break;
+ }
+}
+
+static void killrunning(char *pidfile)
+{
+ FILE *pidfd;
+ int pid;
+
+ if((pidfd = fopen(pidfile, "r")) == NULL) {
+ fprintf(stderr, "mctab -k: could not read PID file %s: %s\n", pidfile, strerror(errno));
+ exit(1);
+ }
+ fscanf(pidfd, "%i", &pid);
+ if(kill(pid, SIGTERM)) {
+ fprintf(stderr, "mctab -k: could not kill %i: %s\n", pid, strerror(errno));
+ exit(1);
}
+ fclose(pidfd);
}
int main(int argc, char **argv)
{
int c;
- int sock;
+ int sock, tap;
struct in_addr group;
int port;
+ char *tapname;
+ char *pidfile;
+ int daemonize, killold;
+ struct sockaddr_in dst;
+ FILE *pidfd;
- while((c = getopt(argc, argv, "h")) >= 0) {
+ tapname = "mctap";
+ daemonize = killold = 0;
+ pidfile = NULL;
+ while((c = getopt(argc, argv, "hD:dpP:k")) >= 0) {
switch(c) {
+ case 'D':
+ tapname = optarg;
+ break;
+ case 'd':
+ daemonize = 1;
+ break;
+ case 'p':
+ pidfile = (void *)-1;
+ break;
+ case 'P':
+ pidfile = optarg;
+ break;
+ case 'k':
+ killold = 1;
+ if(pidfile == NULL)
+ pidfile = (void *)-1;
+ break;
case 'h':
usage(stdout);
return(0);
exit(1);
}
}
+ if(pidfile == (void *)-1)
+ pidfile = sprintf2("/var/run/mctap.%s.pid", tapname);
+ if(killold) {
+ killrunning(pidfile);
+ return(0);
+ }
if(argc - optind < 2) {
usage(stderr);
exit(1);
fprintf(stderr, "mctap: could not create multicast socket: %s\n", strerror(errno));
exit(1);
}
+ if((tap = maketap(tapname)) < 0) {
+ fprintf(stderr, "mctap: could not create TAP device: %s\n", strerror(errno));
+ exit(1);
+ }
+ openlog(sprintf2("mctap-%s", tapname), LOG_PID, LOG_DAEMON);
+
+ pidfd = NULL;
+ if((pidfile != NULL) && ((pidfd = fopen(pidfile, "w")) == NULL)) {
+ fprintf(stderr, "mctap: could not create PID file %s: %s\n", pidfile, strerror(errno));
+ exit(1);
+ }
+ if(daemonize)
+ daemon(0, 0);
+ if(pidfd != NULL) {
+ fprintf(pidfd, "%i\n", getpid());
+ fclose(pidfd);
+ }
+
+ signal(SIGTERM, sighand);
+ signal(SIGINT, sighand);
+ signal(SIGHUP, sighand);
+
+ memset(&dst, 0, sizeof(dst));
+ dst.sin_family = AF_INET;
+ dst.sin_addr = group;
+ dst.sin_port = htons(port);
+ syslog(LOG_INFO, "bridge created with MAC %02x:%02x:%02x:%02x:%02x:%02x", macaddr[0], macaddr[1], macaddr[2], macaddr[3], macaddr[4], macaddr[5]);
+ bridge(sock, tap, (struct sockaddr *)&dst, sizeof(dst));
+ syslog(LOG_INFO, "exiting");
- test(sock);
+ if(pidfile != NULL)
+ unlink(pidfile);
return(0);
}
Dolda2000 GitWeb / mctap.git / blobdiff