From: Guus Sliepen <guus@tinc-vpn.org>
Date: Sun, 11 Jan 2015 15:12:57 +0000 (+0100)
Subject: Move UDP probe reply code into its own function.
X-Git-Tag: release-1.1pre12~210
X-Git-Url: https://tinc-vpn.org/git/browse?a=commitdiff_plain;h=79b6adb489dde4ae92207ae7b9146f4e141c946c;p=tinc
Move UDP probe reply code into its own function.
This reduces the level of indentation, and prepares for sending gratuitous type 2 probe replies.
---
diff --git a/src/net_packet.c b/src/net_packet.c
index 96f8f10e..52c46e14 100644
--- a/src/net_packet.c
+++ b/src/net_packet.c
@@ -101,75 +101,79 @@ static void udp_probe_timeout_handler(void *data) {
n->maxmtu = MTU;
}
-static void udp_probe_h(node_t *n, vpn_packet_t *packet, length_t len) {
- if(!DATA(packet)[0]) {
- /* It's a probe request, send back a reply */
+static void send_udp_probe_reply(node_t *n, vpn_packet_t *packet, length_t len) {
+ if(!n->status.sptps && !n->status.validkey) {
+ // But not if we don't have his key.
+ logger(DEBUG_TRAFFIC, LOG_INFO, "Got UDP probe request from %s (%s) but we don't have his key yet", n->name, n->hostname);
+ return;
+ }
- if(!n->status.sptps && !n->status.validkey) {
- // But not if we don't have his key.
- logger(DEBUG_TRAFFIC, LOG_INFO, "Got UDP probe request from %s (%s) but we don't have his key yet", n->name, n->hostname);
- return;
- }
+ logger(DEBUG_TRAFFIC, LOG_INFO, "Got UDP probe request %d from %s (%s)", packet->len, n->name, n->hostname);
- logger(DEBUG_TRAFFIC, LOG_INFO, "Got UDP probe request %d from %s (%s)", packet->len, n->name, n->hostname);
+ /* Type 2 probe replies were introduced in protocol 17.3 */
+ if ((n->options >> 24) >= 3) {
+ uint8_t *data = DATA(packet);
+ *data++ = 2;
+ uint16_t len16 = htons(len);
+ memcpy(data, &len16, 2);
+ packet->len = MIN_PROBE_SIZE;
+ } else {
+ /* Legacy protocol: n won't understand type 2 probe replies. */
+ DATA(packet)[0] = 1;
+ }
- /* Type 2 probe replies were introduced in protocol 17.3 */
- if ((n->options >> 24) >= 3) {
- uint8_t *data = DATA(packet);
- *data++ = 2;
- uint16_t len16 = htons(len); memcpy(data, &len16, 2); data += 2;
- packet->len = MIN_PROBE_SIZE;
- } else {
- /* Legacy protocol: n won't understand type 2 probe replies. */
- DATA(packet)[0] = 1;
- }
+ /* Temporarily set udp_confirmed, so that the reply is sent
+ back exactly the way it came in. */
- /* Temporarily set udp_confirmed, so that the reply is sent
- back exactly the way it came in. */
+ bool udp_confirmed = n->status.udp_confirmed;
+ n->status.udp_confirmed = true;
+ send_udppacket(n, packet);
+ n->status.udp_confirmed = udp_confirmed;
+}
- bool udp_confirmed = n->status.udp_confirmed;
- n->status.udp_confirmed = true;
- send_udppacket(n, packet);
- n->status.udp_confirmed = udp_confirmed;
- } else {
- length_t probelen = len;
- if (DATA(packet)[0] == 2) {
- if (len < 3)
- logger(DEBUG_TRAFFIC, LOG_WARNING, "Received invalid (too short) UDP probe reply from %s (%s)", n->name, n->hostname);
- else {
- uint16_t probelen16; memcpy(&probelen16, DATA(packet) + 1, 2); probelen = ntohs(probelen16);
- }
- }
- logger(DEBUG_TRAFFIC, LOG_INFO, "Got type %d UDP probe reply %d from %s (%s)", DATA(packet)[0], probelen, n->name, n->hostname);
+static void udp_probe_h(node_t *n, vpn_packet_t *packet, length_t len) {
+ if(!DATA(packet)[0]) {
+ /* It's a probe request, send back a reply */
+ return send_udp_probe_reply(n, packet, len);
+ }
+
+ if (DATA(packet)[0] == 2) {
+ // It's a type 2 probe reply, use the length field inside the packet
+ uint16_t len16;
+ memcpy(&len16, DATA(packet) + 1, 2);
+ len = ntohs(len16);
+ }
- /* It's a valid reply: now we know bidirectional communication
- is possible using the address and socket that the reply
- packet used. */
- n->status.udp_confirmed = true;
+ logger(DEBUG_TRAFFIC, LOG_INFO, "Got type %d UDP probe reply %d from %s (%s)", DATA(packet)[0], len, n->name, n->hostname);
- if(udp_discovery) {
- timeout_del(&n->udp_ping_timeout);
- timeout_add(&n->udp_ping_timeout, &udp_probe_timeout_handler, n, &(struct timeval){udp_discovery_timeout, 0});
- }
+ /* It's a valid reply: now we know bidirectional communication
+ is possible using the address and socket that the reply
+ packet used. */
+ n->status.udp_confirmed = true;
- if(probelen > n->maxmtu) {
- logger(DEBUG_TRAFFIC, LOG_INFO, "Increase in PMTU to %s (%s) detected, restarting PMTU discovery", n->name, n->hostname);
- n->minmtu = probelen;
- n->maxmtu = MTU;
- /* Set mtuprobes to 1 so that try_mtu() doesn't reset maxmtu */
- n->mtuprobes = 1;
- return;
- } else if(n->mtuprobes < 0 && probelen == n->maxmtu) {
- /* We got a maxmtu sized packet, confirming the PMTU is still valid. */
- n->mtuprobes = -1;
- }
+ if(udp_discovery) {
+ timeout_del(&n->udp_ping_timeout);
+ timeout_add(&n->udp_ping_timeout, &udp_probe_timeout_handler, n, &(struct timeval){udp_discovery_timeout, 0});
+ }
+
+ if(len > n->maxmtu) {
+ logger(DEBUG_TRAFFIC, LOG_INFO, "Increase in PMTU to %s (%s) detected, restarting PMTU discovery", n->name, n->hostname);
+ n->minmtu = len;
+ n->maxmtu = MTU;
+ /* Set mtuprobes to 1 so that try_mtu() doesn't reset maxmtu */
+ n->mtuprobes = 1;
+ return;
+ } else if(n->mtuprobes < 0 && len == n->maxmtu) {
+ /* We got a maxmtu sized packet, confirming the PMTU is still valid. */
+ n->mtuprobes = -1;
+ n->mtu_ping_sent = now;
+ }
- /* If applicable, raise the minimum supported MTU */
+ /* If applicable, raise the minimum supported MTU */
- if(n->minmtu < probelen) {
- n->minmtu = probelen;
- try_fix_mtu(n);
- }
+ if(n->minmtu < len) {
+ n->minmtu = len;
+ try_fix_mtu(n);
}
}