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Retry multicast group join instead of exiting

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Multicast group join failures can occur during system startup
This commit is contained in:
emanuele-f 2019-07-06 11:19:27 +02:00
parent 593bde7944
commit 1c9e029b88
1 changed files with 33 additions and 18 deletions
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51
edge_utils.c
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@ -112,6 +112,7 @@ struct n2n_edge {
#ifndef SKIP_MULTICAST_PEERS_DISCOVERY
n2n_sock_t multicast_peer; /**< Multicast peer group (for local edges) */
int udp_multicast_sock; /**< socket for local multicast registrations. */
int multicast_joined; /**< 1 if the group has been joined.*/
#endif
/* Peers */
@ -329,10 +330,12 @@ static void supernode2addr(n2n_sock_t * sn, const n2n_sn_name_t addrIn) {
*/
static void register_with_local_peers(n2n_edge_t * eee) {
#ifndef SKIP_MULTICAST_PEERS_DISCOVERY
/* no send registration to the local multicast group */
traceEvent(TRACE_INFO, "Registering with multicast group %s:%u",
N2N_MULTICAST_GROUP, N2N_MULTICAST_PORT);
send_register(eee, &(eee->multicast_peer), NULL);
if(eee->multicast_joined) {
/* send registration to the local multicast group */
traceEvent(TRACE_INFO, "Registering with multicast group %s:%u",
N2N_MULTICAST_GROUP, N2N_MULTICAST_PORT);
send_register(eee, &(eee->multicast_peer), NULL);
}
#else
traceEvent(TRACE_DEBUG, "Multicast peers discovery is disabled, skipping");
#endif
@ -572,6 +575,30 @@ static ssize_t sendto_sock(int fd, const void * buf,
/* ************************************** */
/* Bind eee->udp_multicast_sock to multicast group */
static void check_join_multicast_group(n2n_edge_t *eee) {
if(!eee->multicast_joined) {
struct ip_mreq mreq;
mreq.imr_multiaddr.s_addr = inet_addr(N2N_MULTICAST_GROUP);
mreq.imr_interface.s_addr = htonl(INADDR_ANY);
if(setsockopt(eee->udp_multicast_sock, IPPROTO_IP, IP_ADD_MEMBERSHIP, (char *)&mreq, sizeof(mreq)) < 0) {
traceEvent(TRACE_WARNING, "Failed to bind to local multicast group %s:%u [errno %u]",
N2N_MULTICAST_GROUP, N2N_MULTICAST_PORT, errno);
#ifdef WIN32
traceEvent(TRACE_ERROR, "WSAGetLastError(): %u", WSAGetLastError());
#endif
} else {
traceEvent(TRACE_NORMAL, "Successfully joined multicast group %s:%u",
N2N_MULTICAST_GROUP, N2N_MULTICAST_PORT);
eee->multicast_joined = 1;
}
}
}
/* ************************************** */
/** Send a REGISTER_SUPER packet to the current supernode. */
static void send_register_super(n2n_edge_t * eee,
const n2n_sock_t * supernode) {
@ -723,6 +750,8 @@ static void update_supernode_reg(n2n_edge_t * eee, time_t nowTime) {
} else if(nowTime < (eee->last_register_req + eee->conf.register_interval))
return; /* Too early */
check_join_multicast_group(eee);
if(0 == eee->sup_attempts) {
/* Give up on that supernode and try the next one. */
++(eee->sn_idx);
@ -1767,8 +1796,6 @@ static int edge_init_sockets(n2n_edge_t *eee, int udp_local_port, int mgmt_port)
if(eee->udp_multicast_sock < 0)
return(-3);
else {
/* Bind eee->udp_multicast_sock to multicast group */
struct ip_mreq mreq;
u_int enable_reuse = 1;
/* allow multiple sockets to use the same PORT number */
@ -1776,18 +1803,6 @@ static int edge_init_sockets(n2n_edge_t *eee, int udp_local_port, int mgmt_port)
#ifdef SO_REUSEPORT /* no SO_REUSEPORT in Windows / old linux versions */
setsockopt(eee->udp_multicast_sock, SOL_SOCKET, SO_REUSEPORT, &enable_reuse, sizeof(enable_reuse));
#endif
mreq.imr_multiaddr.s_addr = inet_addr(N2N_MULTICAST_GROUP);
mreq.imr_interface.s_addr = htonl(INADDR_ANY);
if (setsockopt(eee->udp_multicast_sock, IPPROTO_IP, IP_ADD_MEMBERSHIP, (char *)&mreq, sizeof(mreq)) < 0) {
traceEvent(TRACE_ERROR, "Failed to bind to local multicast group %s:%u [errno %u]",
N2N_MULTICAST_GROUP, N2N_MULTICAST_PORT, errno);
#ifdef WIN32
traceEvent(TRACE_ERROR, "WSAGetLastError(): %u", WSAGetLastError());
#endif
return(-4);
}
}
#endif