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increased resilience to supernode failure (#660)

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Logan oos Even 2021-03-09 04:46:42 +05:45 committed by GitHub
parent 1bcc64ccb3
commit 23a9c871f8
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GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 69 additions and 26 deletions
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1
include/n2n_typedefs.h
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@ -426,6 +426,7 @@ struct peer_info {
SN_SELECTION_CRITERION_DATA_TYPE selection_criterion;
uint64_t last_valid_time_stamp;
char *ip_addr;
uint8_t local;
UT_hash_handle hh; /* makes this structure hashable */
};

94
src/edge_utils.c
View File

@ -31,6 +31,7 @@ static void send_register (n2n_edge_t *eee, const n2n_sock_t *remote_peer, const
static void check_peer_registration_needed (n2n_edge_t *eee,
uint8_t from_supernode,
uint8_t via_multicast,
const n2n_mac_t mac,
const n2n_ip_subnet_t *dev_addr,
const n2n_desc_t *dev_desc,
@ -42,6 +43,7 @@ static void edge_cleanup_routes (n2n_edge_t *eee);
static void check_known_peer_sock_change (n2n_edge_t *eee,
uint8_t from_supernode,
uint8_t via_multicast,
const n2n_mac_t mac,
const n2n_ip_subnet_t *dev_addr,
const n2n_desc_t *dev_desc,
@ -531,6 +533,7 @@ static struct peer_info* find_peer_by_sock (const n2n_sock_t *sock, struct peer_
*/
static void register_with_new_peer (n2n_edge_t *eee,
uint8_t from_supernode,
uint8_t via_multicast,
const n2n_mac_t mac,
const n2n_ip_subnet_t *dev_addr,
const n2n_desc_t *dev_desc,
@ -551,6 +554,8 @@ static void register_with_new_peer (n2n_edge_t *eee,
scan->sock = *peer;
scan->timeout = eee->conf.register_interval; /* TODO: should correspond to the peer supernode registration timeout */
scan->last_valid_time_stamp = initial_time_stamp();
if(via_multicast)
scan->local = 1;
HASH_ADD_PEER(eee->pending_peers, scan);
@ -607,7 +612,6 @@ static void register_with_new_peer (n2n_edge_t *eee,
memcpy(&(scan->dev_addr), dev_addr, sizeof(n2n_ip_subnet_t));
}
if(dev_desc) memcpy(scan->dev_desc, dev_desc, N2N_DESC_SIZE);
}
@ -616,6 +620,7 @@ static void register_with_new_peer (n2n_edge_t *eee,
/** Update the last_seen time for this peer, or get registered. */
static void check_peer_registration_needed (n2n_edge_t *eee,
uint8_t from_supernode,
uint8_t via_multicast,
const n2n_mac_t mac,
const n2n_ip_subnet_t *dev_addr,
const n2n_desc_t *dev_desc,
@ -638,7 +643,7 @@ static void check_peer_registration_needed (n2n_edge_t *eee,
if(scan == NULL) {
/* Not in known_peers - start the REGISTER process. */
register_with_new_peer(eee, from_supernode, mac, dev_addr, dev_desc, peer);
register_with_new_peer(eee, from_supernode, via_multicast, mac, dev_addr, dev_desc, peer);
} else {
/* Already in known_peers. */
time_t now = time(NULL);
@ -646,9 +651,12 @@ static void check_peer_registration_needed (n2n_edge_t *eee,
if(!from_supernode)
scan->last_p2p = now;
if(via_multicast)
scan->local = 1;
if((now - scan->last_seen) > 0 /* >= 1 sec */) {
/* Don't register too often */
check_known_peer_sock_change(eee, from_supernode, mac, dev_addr, dev_desc, peer, now);
check_known_peer_sock_change(eee, from_supernode, via_multicast, mac, dev_addr, dev_desc, peer, now);
}
}
}
@ -761,6 +769,7 @@ int is_empty_ip_address (const n2n_sock_t * sock) {
*/
static void check_known_peer_sock_change (n2n_edge_t *eee,
uint8_t from_supernode,
uint8_t via_multicast,
const n2n_mac_t mac,
const n2n_ip_subnet_t *dev_addr,
const n2n_desc_t *dev_desc,
@ -796,7 +805,7 @@ static void check_known_peer_sock_change (n2n_edge_t *eee,
HASH_DEL(eee->known_peers, scan);
free(scan);
register_with_new_peer(eee, from_supernode, mac, dev_addr, dev_desc, peer);
register_with_new_peer(eee, from_supernode, via_multicast, mac, dev_addr, dev_desc, peer);
} else {
/* Don't worry about what the supernode reports, it could be seeing a different socket. */
}
@ -1191,7 +1200,6 @@ static void send_register (n2n_edge_t * eee,
reg.dev_addr.net_bitlen = mask2bitlen(ntohl(eee->device.device_mask));
memcpy(reg.dev_desc, eee->conf.dev_desc, N2N_DESC_SIZE);
idx = 0;
encode_REGISTER(pktbuf, &idx, &cmn, &reg);
@ -1304,6 +1312,9 @@ static void send_grat_arps (n2n_edge_t * eee) {
*/
void update_supernode_reg (n2n_edge_t * eee, time_t now) {
struct peer_info *peer, *tmp_peer;
int cnt = 0;
if(eee->sn_wait && (now > (eee->last_register_req + (eee->conf.register_interval/10)))) {
/* fall through */
traceEvent(TRACE_DEBUG, "update_supernode_reg: doing fast retry.");
@ -1327,12 +1338,21 @@ void update_supernode_reg (n2n_edge_t * eee, time_t now) {
// privileges. as we are not able to check for sufficent privileges here, we only do it
// if port is sufficently high or unset. uncovered: privileged port and sufficent privileges
if((eee->conf.local_port == 0) || (eee->conf.local_port > 1024)) {
// do not explicitly disconnect every time as the condition descibed is rare
(eee->close_socket_counter)++;
if(eee->close_socket_counter >= N2N_CLOSE_SOCKET_COUNTER_MAX) {
eee->close_socket_counter = 0;
supernode_disconnect(eee);
traceEvent(TRACE_DEBUG, "update_supernode_reg disconnected supernode");
// do not explicitly disconnect every time as the condition described is rare, so ...
// ... check that there are no external peers (indicating a working socket) ...
HASH_ITER(hh, eee->known_peers, peer, tmp_peer)
if(!peer->local) {
cnt++;
break;
}
if(!cnt) {
// ... and then count the connection retries
(eee->close_socket_counter)++;
if(eee->close_socket_counter >= N2N_CLOSE_SOCKET_COUNTER_MAX) {
eee->close_socket_counter = 0;
supernode_disconnect(eee);
traceEvent(TRACE_DEBUG, "update_supernode_reg disconnected supernode");
}
}
supernode_connect(eee);
@ -1349,8 +1369,16 @@ void update_supernode_reg (n2n_edge_t * eee, time_t now) {
send_register_super(eee);
}
register_with_local_peers(eee);
// if supernode repeatedly not responding (already waiting), safeguard the
// current known connections to peers by re-registering
if(eee->sn_wait)
HASH_ITER(hh, eee->known_peers, peer, tmp_peer)
if((now - peer->last_seen) > REGISTER_SUPER_INTERVAL_DFL)
send_register(eee, &(peer->sock), peer->mac_addr);
eee->sn_wait = 1;
eee->last_register_req = now;
@ -1877,24 +1905,33 @@ static int send_packet (n2n_edge_t * eee,
n2n_sock_str_t sockbuf;
n2n_sock_t destination;
macstr_t mac_buf;
struct peer_info *peer, *tmp_peer;
/* hexdump(pktbuf, pktlen); */
is_p2p = find_peer_destination(eee, dstMac, &destination);
if(is_p2p)
++(eee->stats.tx_p2p);
else {
++(eee->stats.tx_sup);
if(!memcmp(dstMac, broadcast_mac, N2N_MAC_SIZE))
++(eee->stats.tx_sup_broadcast);
}
traceEvent(TRACE_INFO, "Tx PACKET to %s (dest=%s) [%u B]",
sock_to_cstr(sockbuf, &destination),
macaddr_str(mac_buf, dstMac), pktlen);
if(is_p2p)
++(eee->stats.tx_p2p);
else
++(eee->stats.tx_sup);
if(!memcmp(dstMac, broadcast_mac, N2N_MAC_SIZE)) {
++(eee->stats.tx_sup_broadcast);
// if no supernode around, foward the broadcast to all known peers
if(eee->sn_wait) {
HASH_ITER(hh, eee->known_peers, peer, tmp_peer)
/* s = */ sendto_sock(eee, pktbuf, pktlen, &peer->sock);
return 0;
}
// fall through otherwise
}
/* s = */ sendto_sock(eee, pktbuf, pktlen, &destination);
return 0;
@ -2227,7 +2264,8 @@ void process_udp (n2n_edge_t *eee, const struct sockaddr_in *sender_sock, const
}
/* Update the sender in peer table entry */
check_peer_registration_needed(eee, from_supernode, pkt.srcMac, NULL, NULL, orig_sender);
check_peer_registration_needed(eee, from_supernode, via_multicast,
pkt.srcMac, NULL, NULL, orig_sender);
handle_PACKET(eee, from_supernode, &pkt, orig_sender, udp_buf + idx, udp_size - idx);
break;
@ -2280,7 +2318,8 @@ void process_udp (n2n_edge_t *eee, const struct sockaddr_in *sender_sock, const
sock_to_cstr(sockbuf1, &sender), sock_to_cstr(sockbuf2, orig_sender));
}
check_peer_registration_needed(eee, from_supernode, reg.srcMac, &reg.dev_addr, (const n2n_desc_t*)&reg.dev_desc, orig_sender);
check_peer_registration_needed(eee, from_supernode, via_multicast,
reg.srcMac, &reg.dev_addr, (const n2n_desc_t*)&reg.dev_desc, orig_sender);
break;
}
@ -2742,10 +2781,13 @@ int run_edge_loop (n2n_edge_t *eee, int *keep_running) {
// finished processing select data
update_supernode_reg(eee, now);
numPurged = purge_expired_nodes(&eee->known_peers,
eee->sock, NULL,
&last_purge_known,
PURGE_REGISTRATION_FREQUENCY, REGISTRATION_TIMEOUT);
numPurged = 0;
// keep, i.e. do not purge, the known peers while no supernode supernode connection
if(!eee->sn_wait)
numPurged = purge_expired_nodes(&eee->known_peers,
eee->sock, NULL,
&last_purge_known,
PURGE_REGISTRATION_FREQUENCY, REGISTRATION_TIMEOUT);
numPurged += purge_expired_nodes(&eee->pending_peers,
eee->sock, NULL,
&last_purge_pending,