static void process_rs(int sock, struct Interface *iface, unsigned char *msg, int len, struct sockaddr_in6 *addr)
{
/* validation */
len -= sizeof(struct nd_router_solicit);
uint8_t *opt_str = (uint8_t *) (msg + sizeof(struct nd_router_solicit));
while (len > 0) {
if (len < 2) {
flog(LOG_WARNING, "trailing garbage in RS");
return;
}
int const optlen = (opt_str[1] << 3);
if (optlen == 0) {
flog(LOG_WARNING, "zero length option in RS");
return;
} else if (optlen > len) {
flog(LOG_WARNING, "option length greater than total length in RS");
return;
}
if (*opt_str == ND_OPT_SOURCE_LINKADDR && IN6_IS_ADDR_UNSPECIFIED(&addr->sin6_addr)) {
flog(LOG_WARNING,
"received icmpv6 RS packet with unspecified source address and there is a lladdr option");
return;
}
len -= optlen;
opt_str += optlen;
}
struct timespec ts;
clock_gettime(CLOCK_MONOTONIC, &ts);
double const delay = (MAX_RA_DELAY_SECONDS * rand() / (RAND_MAX + 1.0));
if (iface->UnicastOnly) {
send_ra_forall(sock, iface, &addr->sin6_addr);
} else if (timespecdiff(&ts, &iface->times.last_multicast) / 1000.0 < iface->MinDelayBetweenRAs) {
/* last RA was sent only a few moments ago, don't send another immediately. */
double next =
iface->MinDelayBetweenRAs - (ts.tv_sec + ts.tv_nsec / 1000000000.0) + (iface->times.last_multicast.tv_sec +
iface->times.last_multicast.tv_nsec /
1000000000.0) + delay;
dlog(LOG_DEBUG, 5, "%s: rate limiting RA's, rescheduling RA %f seconds from now", iface->props.name, next);
reschedule_iface(iface, next);
} else {
/* no RA sent in a while, send a multicast reply */
send_ra_forall(sock, iface, NULL);
double next = rand_between(iface->MinRtrAdvInterval, iface->MaxRtrAdvInterval);
reschedule_iface(iface, next);
}
dlog(LOG_DEBUG, 2, "%s processed an RS", iface->props.name);
}
static void timer_handler(int sock, struct Interface *iface)
{
dlog(LOG_DEBUG, 1, "timer_handler called for %s", iface->props.name);
if (send_ra_forall(sock, iface, NULL) != 0) {
dlog(LOG_DEBUG, 4, "send_ra_forall failed on interface %s", iface->props.name);
}
double next = rand_between(iface->MinRtrAdvInterval, iface->MaxRtrAdvInterval);
reschedule_iface(iface, next);
}
/*
* send initial advertisement and set timers
*/
static void kickoff_adverts(int sock, struct Interface *iface)
{
clock_gettime(CLOCK_MONOTONIC, &iface->times.last_ra_time);
if (iface->UnicastOnly)
return;
clock_gettime(CLOCK_MONOTONIC, &iface->times.last_multicast);
/* send an initial advertisement */
if (send_ra_forall(sock, iface, NULL) != 0) {
dlog(LOG_DEBUG, 4, "send_ra_forall failed on interface %s", iface->props.name);
}
double next = min(MAX_INITIAL_RTR_ADVERT_INTERVAL, iface->MaxRtrAdvInterval);
reschedule_iface(iface, next);
}
