X-Git-Url: https://tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fnet_packet.c;h=44f9ef45c022e06f54b27f171b9c0a11cc4e3b62;hb=e97e9b22cb6061070611212a06756fb493846955;hp=99063ac25a245ff922993b8ae28c0d0a29319255;hpb=eb7a0db18ea71a44999d6a37b4b179dac0ed9bc7;p=tinc

diff --git a/src/net_packet.c b/src/net_packet.c
index 99063ac2..44f9ef45 100644
--- a/src/net_packet.c
+++ b/src/net_packet.c
@@ -52,6 +52,11 @@
 #define MAX(a, b) ((a) > (b) ? (a) : (b))
 #endif
 
+/* The minimum size of a probe is 14 bytes, but since we normally use CBC mode
+   encryption, we can add a few extra random bytes without increasing the
+   resulting packet size. */
+#define MIN_PROBE_SIZE 18
+
 int keylifetime = 0;
 #ifdef HAVE_LZO
 static char lzo_wrkmem[LZO1X_999_MEM_COMPRESS > LZO1X_1_MEM_COMPRESS ? LZO1X_999_MEM_COMPRESS : LZO1X_1_MEM_COMPRESS];
@@ -112,11 +117,7 @@ static void udp_probe_h(node_t *n, vpn_packet_t *packet, length_t len) {
 			uint8_t *data = DATA(packet);
 			*data++ = 2;
 			uint16_t len16 = htons(len); memcpy(data, &len16, 2); data += 2;
-			struct timeval now;
-			gettimeofday(&now, NULL);
-			uint32_t sec = htonl(now.tv_sec); memcpy(data, &sec, 4); data += 4;
-			uint32_t usec = htonl(now.tv_usec); memcpy(data, &usec, 4); data += 4;
-			packet->len = 14; // Minimum size for any probe packet.
+			packet->len = MIN_PROBE_SIZE;
 		} else {
 			/* Legacy protocol: n won't understand type 2 probe replies. */
 			DATA(packet)[0] = 1;
@@ -166,31 +167,6 @@ static void udp_probe_h(node_t *n, vpn_packet_t *packet, length_t len) {
 			n->minmtu = probelen;
 			try_fix_mtu(n);
 		}
-
-		/* Calculate RTT.
-		   The RTT is the time between the MTU probe burst was sent and the first
-		   reply is received.
-		 */
-
-		struct timeval now, diff;
-		gettimeofday(&now, NULL);
-		timersub(&now, &n->probe_time, &diff);
-
-		struct timeval probe_timestamp = now;
-		if (DATA(packet)[0] == 2 && packet->len >= 11) {
-			uint32_t sec; memcpy(&sec, DATA(packet) + 3, 4);
-			uint32_t usec; memcpy(&usec, DATA(packet) + 7, 4);
-			probe_timestamp.tv_sec = ntohl(sec);
-			probe_timestamp.tv_usec = ntohl(usec);
-		}
-		
-		n->probe_counter++;
-
-		if(n->probe_counter == 1) {
-			n->rtt = diff.tv_sec + diff.tv_usec * 1e-6;
-			n->probe_time = probe_timestamp;
-			logger(DEBUG_TRAFFIC, LOG_DEBUG, "%s (%s) RTT %.2f ms, rx packet loss %.2f %%", n->name, n->hostname, n->rtt * 1e3, n->packetloss * 1e2);
-		}
 	}
 }
 
@@ -882,12 +858,12 @@ static void try_udp(node_t* n) {
 	int interval = n->status.udp_confirmed ? udp_discovery_keepalive_interval : udp_discovery_interval;
 
 	if(ping_tx_elapsed.tv_sec >= interval) {
-		send_udp_probe_packet(n, MAX(n->minmtu, 16));
+		send_udp_probe_packet(n, MIN_PROBE_SIZE);
 		n->udp_ping_sent = now;
 
 		if(localdiscovery && !n->status.udp_confirmed && n->prevedge) {
 			n->status.send_locally = true;
-			send_udp_probe_packet(n, 16);
+			send_udp_probe_packet(n, MIN_PROBE_SIZE);
 			n->status.send_locally = false;
 		}
 	}
@@ -992,23 +968,26 @@ static void try_mtu(node_t *n) {
 
 	/* mtuprobes == 0..19: initial discovery, send bursts with 1 second interval, mtuprobes++
 	   mtuprobes ==    20: fix MTU, and go to -1
-	   mtuprobes ==    -1: send one >maxmtu probe every pingtimeout */
+	   mtuprobes ==    -1: send one >maxmtu probe every pinginterval */
 
 	struct timeval elapsed;
-	timersub(&now, &n->probe_sent_time, &elapsed);
+	timersub(&now, &n->mtu_ping_sent, &elapsed);
 	if(n->mtuprobes >= 0) {
 		if(n->mtuprobes != 0 && elapsed.tv_sec == 0 && elapsed.tv_usec < 333333)
 			return;
 	} else {
-		if(elapsed.tv_sec < pingtimeout)
+		if(elapsed.tv_sec < pinginterval)
 			return;
 	}
 
+	n->mtu_ping_sent = now;
+
 	try_fix_mtu(n);
 
 	if(n->mtuprobes < 0) {
-		/* After the initial discovery, we only send one >maxmtu probe
-		   to detect PMTU increases. */
+		/* After the initial discovery, we only send one maxmtu and one
+		   maxmtu+1 probe to detect PMTU increases. */
+		send_udp_probe_packet(n, n->maxmtu);
 		if(n->maxmtu + 1 < MTU)
 			send_udp_probe_packet(n, n->maxmtu + 1);
 	} else {
@@ -1055,23 +1034,6 @@ static void try_mtu(node_t *n) {
 		if(n->mtuprobes >= 0)
 			n->mtuprobes++;
 	}
-
-	n->probe_counter = 0;
-	n->probe_sent_time = now;
-	n->probe_time = now;
-
-	/* Calculate the packet loss of incoming traffic by comparing the rate of
-	   packets received to the rate with which the sequence number has increased.
-	   TODO: this is unrelated to PMTU discovery - it should be moved elsewhere.
-	 */
-
-	if(n->received > n->prev_received)
-		n->packetloss = 1.0 - (n->received - n->prev_received) / (float)(n->received_seqno - n->prev_received_seqno);
-	else
-		n->packetloss = n->received_seqno <= n->prev_received_seqno;
-
-	n->prev_received_seqno = n->received_seqno;
-	n->prev_received = n->received;
 }
 
 /* These functions try to establish a tunnel to a node (or its relay) so that