#include <sys/types.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <arpa/inet.h>
#include <net/if.h>
#include <netinet/in.h>
#include <netinet6/ip6_mroute.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <signal.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
void __dead usage(void);
void sigexit(int);
size_t get_sysctl(const int *mib, u_int mcnt, char **buf);
void __dead
usage(void)
{
fprintf(stderr,
"mc6route [-b] [-f file] [-g group] -i ifname [-n timeout] -o outname\n"
" [-r timeout]\n"
" -b fork to background after setup\n"
" -f file print message to log file, default stdout\n"
" -g group multicast group, default 224.0.0.123\n"
" -i ifname multicast interface address\n"
" -n timeout expect not to receive any message until timeout\n"
" -o outname outgoing interface address\n"
" -r timeout receive timeout in seconds\n");
exit(2);
}
int
main(int argc, char *argv[])
{
struct mif6ctl mif;
struct mf6cctl mfc;
struct mif6info *minfo;
FILE *log;
const char *errstr, *file, *group, *ifname, *outname;
char *buf;
size_t needed;
u_int64_t pktin, pktout;
int value, ch, s, fd, background, norecv;
unsigned int timeout;
pid_t pid;
int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, IPV6CTL_MRTMIF };
background = 0;
log = stdout;
file = NULL;
group = "ff04::123";
ifname = NULL;
norecv = 0;
outname = NULL;
timeout = 0;
while ((ch = getopt(argc, argv, "bf:g:i:n:o:r:")) != -1) {
switch (ch) {
case 'b':
background = 1;
break;
case 'f':
file = optarg;
break;
case 'g':
group = optarg;
break;
case 'i':
ifname = optarg;
break;
case 'n':
norecv = 1;
timeout = strtonum(optarg, 1, INT_MAX, &errstr);
if (errstr != NULL)
errx(1, "no timeout is %s: %s", errstr, optarg);
break;
case 'o':
outname = optarg;
break;
case 'r':
timeout = strtonum(optarg, 1, INT_MAX, &errstr);
if (errstr != NULL)
errx(1, "timeout is %s: %s", errstr, optarg);
break;
default:
usage();
}
}
argc -= optind;
argv += optind;
if (ifname == NULL)
errx(2, "no ifname");
if (outname == NULL)
errx(2, "no outname");
if (argc)
usage();
if (file != NULL) {
log = fopen(file, "w");
if (log == NULL)
err(1, "fopen %s", file);
}
s = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6);
if (s == -1)
err(1, "socket");
value = 1;
if (setsockopt(s, IPPROTO_IPV6, MRT6_INIT, &value, sizeof(value)) == -1)
err(1, "setsockopt MRT6_INIT");
memset(&mif, 0, sizeof(mif));
mif.mif6c_mifi = 0;
mif.mif6c_pifi = if_nametoindex(ifname);
if (mif.mif6c_pifi == 0)
err(1, "if_nametoindex %s", ifname);
if (setsockopt(s, IPPROTO_IPV6, MRT6_ADD_MIF, &mif, sizeof(mif)) == -1)
err(1, "setsockopt MRT6_ADD_MIF %s", ifname);
memset(&mif, 0, sizeof(mif));
mif.mif6c_mifi = 1;
mif.mif6c_pifi = if_nametoindex(outname);
if (mif.mif6c_pifi == 0)
err(1, "if_nametoindex %s", outname);
if (setsockopt(s, IPPROTO_IPV6, MRT6_ADD_MIF, &mif, sizeof(mif)) == -1)
err(1, "setsockopt MRT6_ADD_MIF %s", outname);
memset(&mfc, 0, sizeof(mfc));
if (inet_pton(AF_INET6, group, &mfc.mf6cc_mcastgrp.sin6_addr) == -1)
err(1, "inet_pton %s", group);
mfc.mf6cc_parent = 0;
IF_SET(1, &mfc.mf6cc_ifset);
if (setsockopt(s, IPPROTO_IPV6, MRT6_ADD_MFC, &mfc, sizeof(mfc)) == -1)
err(1, "setsockopt MRT6_ADD_MFC %s", ifname);
if (background) {
pid = fork();
switch (pid) {
case -1:
err(1, "fork");
case 0:
fd = open("/dev/null", O_RDWR);
if (fd == -1)
err(1, "open /dev/null");
if (dup2(fd, 0) == -1)
err(1, "dup 0");
if (dup2(fd, 1) == -1)
err(1, "dup 1");
if (dup2(fd, 2) == -1)
err(1, "dup 2");
break;
default:
_exit(0);
}
}
if (timeout) {
if (norecv) {
if (signal(SIGALRM, sigexit) == SIG_ERR)
err(1, "signal SIGALRM");
}
alarm(timeout);
}
buf = NULL;
pktin = pktout = 0;
do {
struct timespec sleeptime = { 0, 10000000 };
if (nanosleep(&sleeptime, NULL) == -1)
err(1, "nanosleep");
needed = get_sysctl(mib, sizeof(mib) / sizeof(mib[0]), &buf);
for (minfo = (struct mif6info *)buf;
(char *)minfo < buf + needed;
minfo++) {
switch (minfo->m6_ifindex) {
case 0:
if (pktin != minfo->m6_pkt_in) {
fprintf(log, "<<< %llu\n",
minfo->m6_pkt_in);
fflush(log);
}
pktin = minfo->m6_pkt_in;
break;
case 1:
if (pktout != minfo->m6_pkt_out) {
fprintf(log, ">>> %llu\n",
minfo->m6_pkt_out);
fflush(log);
}
pktout = minfo->m6_pkt_out;
break;
}
}
} while (pktin == 0 || pktout == 0);
free(buf);
if (norecv)
errx(1, "pktin %llu, pktout %llu", pktin, pktout);
return 0;
}
void
sigexit(int sig)
{
_exit(0);
}
size_t
get_sysctl(const int *mib, u_int mcnt, char **buf)
{
size_t needed;
while (1) {
if (sysctl(mib, mcnt, NULL, &needed, NULL, 0) == -1)
err(1, "sysctl-estimate");
if (needed == 0)
break;
if ((*buf = realloc(*buf, needed)) == NULL)
err(1, NULL);
if (sysctl(mib, mcnt, *buf, &needed, NULL, 0) == -1) {
if (errno == ENOMEM)
continue;
err(1, "sysctl");
}
break;
}
return needed;
}
