Fix compression when using the SPTPS protocol.
[tinc] / src / net_packet.c
index db571ba..6f7a3a1 100644 (file)
 
 #include "system.h"
 
-#include <openssl/rand.h>
-#include <openssl/err.h>
-#include <openssl/evp.h>
-#include <openssl/pem.h>
-#include <openssl/hmac.h>
-
 #ifdef HAVE_ZLIB
 #include <zlib.h>
 #endif
@@ -62,6 +56,7 @@ static void send_udppacket(node_t *, vpn_packet_t *);
 
 unsigned replaywin = 16;
 bool localdiscovery = false;
+sockaddr_t localdiscovery_address;
 
 #define MAX_SEQNO 1073741824
 
@@ -184,12 +179,25 @@ void send_mtu_probe(node_t *n) {
 }
 
 static void mtu_probe_h(node_t *n, vpn_packet_t *packet, length_t len) {
-       logger(DEBUG_TRAFFIC, LOG_INFO, "Got MTU probe length %d from %s (%s)", packet->len, n->name, n->hostname);
-
        if(!packet->data[0]) {
+               logger(DEBUG_TRAFFIC, LOG_INFO, "Got MTU probe request %d from %s (%s)", packet->len, n->name, n->hostname);
+
                /* It's a probe request, send back a reply */
 
-               packet->data[0] = 1;
+               /* Type 2 probe replies were introduced in protocol 17.3 */
+               if ((n->options >> 24) == 3) {
+                       uint8_t* data = packet->data;
+                       *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 = data - packet->data;
+               } else {
+                       /* Legacy protocol: n won't understand type 2 probe replies. */
+                       packet->data[0] = 1;
+               }
 
                /* Temporarily set udp_confirmed, so that the reply is sent
                   back exactly the way it came in. */
@@ -199,6 +207,16 @@ static void mtu_probe_h(node_t *n, vpn_packet_t *packet, length_t len) {
                send_udppacket(n, packet);
                n->status.udp_confirmed = udp_confirmed;
        } else {
+               length_t probelen = len;
+               if (packet->data[0] == 2) {
+                       if (len < 3)
+                               logger(DEBUG_TRAFFIC, LOG_WARNING, "Received invalid (too short) MTU probe reply from %s (%s)", n->name, n->hostname);
+                       else {
+                               uint16_t probelen16; memcpy(&probelen16, packet->data + 1, 2); probelen = ntohs(probelen16);
+                       }
+               }
+               logger(DEBUG_TRAFFIC, LOG_INFO, "Got type %d MTU probe reply %d from %s (%s)", packet->data[0], probelen, n->name, n->hostname);
+
                /* It's a valid reply: now we know bidirectional communication
                   is possible using the address and socket that the reply
                   packet used. */
@@ -208,7 +226,7 @@ static void mtu_probe_h(node_t *n, vpn_packet_t *packet, length_t len) {
                /* If we haven't established the PMTU yet, restart the discovery process. */
 
                if(n->mtuprobes > 30) {
-                       if (len == n->maxmtu + 8) {
+                       if (probelen == n->maxmtu + 8) {
                                logger(DEBUG_TRAFFIC, LOG_INFO, "Increase in PMTU to %s (%s) detected, restarting PMTU discovery", n->name, n->hostname);
                                n->maxmtu = MTU;
                                n->mtuprobes = 10;
@@ -223,27 +241,38 @@ static void mtu_probe_h(node_t *n, vpn_packet_t *packet, length_t len) {
 
                /* If applicable, raise the minimum supported MTU */
 
-               if(len > n->maxmtu)
-                       len = n->maxmtu;
-               if(n->minmtu < len)
-                       n->minmtu = len;
+               if(probelen > n->maxmtu)
+                       probelen = n->maxmtu;
+               if(n->minmtu < probelen)
+                       n->minmtu = probelen;
 
                /* Calculate RTT and bandwidth.
                   The RTT is the time between the MTU probe burst was sent and the first
                   reply is received. The bandwidth is measured using the time between the
-                  arrival of the first and third probe reply.
+                  arrival of the first and third probe reply (or type 2 probe requests).
                 */
 
                struct timeval now, diff;
                gettimeofday(&now, NULL);
                timersub(&now, &n->probe_time, &diff);
+
+               struct timeval probe_timestamp = now;
+               if (packet->data[0] == 2 && packet->len >= 11) {
+                       uint32_t sec; memcpy(&sec, packet->data + 3, 4);
+                       uint32_t usec; memcpy(&usec, packet->data + 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 = now;
+                       n->probe_time = probe_timestamp;
                } else if(n->probe_counter == 3) {
-                       n->bandwidth = 2.0 * len / (diff.tv_sec + diff.tv_usec * 1e-6);
+                       struct timeval probe_timestamp_diff;
+                       timersub(&probe_timestamp, &n->probe_time, &probe_timestamp_diff);
+                       n->bandwidth = 2.0 * probelen / (probe_timestamp_diff.tv_sec + probe_timestamp_diff.tv_usec * 1e-6);
                        logger(DEBUG_TRAFFIC, LOG_DEBUG, "%s (%s) RTT %.2f ms, burst bandwidth %.3f Mbit/s, rx packet loss %.2f %%", n->name, n->hostname, n->rtt * 1e3, n->bandwidth * 8e-6, n->packetloss * 1e2);
                }
        }
@@ -324,10 +353,10 @@ static bool try_mac(node_t *n, const vpn_packet_t *inpkt) {
        if(n->status.sptps)
                return sptps_verify_datagram(&n->sptps, (char *)&inpkt->seqno, inpkt->len);
 
-       if(!digest_active(&n->indigest) || inpkt->len < sizeof inpkt->seqno + digest_length(&n->indigest))
+       if(!digest_active(n->indigest) || inpkt->len < sizeof inpkt->seqno + digest_length(n->indigest))
                return false;
 
-       return digest_verify(&n->indigest, &inpkt->seqno, inpkt->len - n->indigest.maclength, (const char *)&inpkt->seqno + inpkt->len - n->indigest.maclength);
+       return digest_verify(n->indigest, &inpkt->seqno, inpkt->len - digest_length(n->indigest), (const char *)&inpkt->seqno + inpkt->len - digest_length(n->indigest));
 }
 
 static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
@@ -338,19 +367,27 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
        size_t outlen;
 
        if(n->status.sptps) {
+               if(!n->sptps.state) {
+                       if(!n->status.waitingforkey) {
+                               logger(DEBUG_TRAFFIC, LOG_DEBUG, "Got packet from %s (%s) but we haven't exchanged keys yet", n->name, n->hostname);
+                               send_req_key(n);
+                       } else {
+                               logger(DEBUG_TRAFFIC, LOG_DEBUG, "Got packet from %s (%s) but he hasn't got our key yet", n->name, n->hostname);
+                       }
+                       return;
+               }
                sptps_receive_data(&n->sptps, (char *)&inpkt->seqno, inpkt->len);
                return;
        }
 
-       if(!cipher_active(&n->incipher)) {
-               logger(DEBUG_TRAFFIC, LOG_DEBUG, "Got packet from %s (%s) but he hasn't got our key yet",
-                                       n->name, n->hostname);
+       if(!cipher_active(n->incipher)) {
+               logger(DEBUG_TRAFFIC, LOG_DEBUG, "Got packet from %s (%s) but he hasn't got our key yet", n->name, n->hostname);
                return;
        }
 
        /* Check packet length */
 
-       if(inpkt->len < sizeof inpkt->seqno + digest_length(&n->indigest)) {
+       if(inpkt->len < sizeof inpkt->seqno + digest_length(n->indigest)) {
                logger(DEBUG_TRAFFIC, LOG_DEBUG, "Got too short packet from %s (%s)",
                                        n->name, n->hostname);
                return;
@@ -358,20 +395,20 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
 
        /* Check the message authentication code */
 
-       if(digest_active(&n->indigest)) {
-               inpkt->len -= n->indigest.maclength;
-               if(!digest_verify(&n->indigest, &inpkt->seqno, inpkt->len, (const char *)&inpkt->seqno + inpkt->len)) {
+       if(digest_active(n->indigest)) {
+               inpkt->len -= digest_length(n->indigest);
+               if(!digest_verify(n->indigest, &inpkt->seqno, inpkt->len, (const char *)&inpkt->seqno + inpkt->len)) {
                        logger(DEBUG_TRAFFIC, LOG_DEBUG, "Got unauthenticated packet from %s (%s)", n->name, n->hostname);
                        return;
                }
        }
        /* Decrypt the packet */
 
-       if(cipher_active(&n->incipher)) {
+       if(cipher_active(n->incipher)) {
                outpkt = pkt[nextpkt++];
                outlen = MAXSIZE;
 
-               if(!cipher_decrypt(&n->incipher, &inpkt->seqno, inpkt->len, &outpkt->seqno, &outlen, true)) {
+               if(!cipher_decrypt(n->incipher, &inpkt->seqno, inpkt->len, &outpkt->seqno, &outlen, true)) {
                        logger(DEBUG_TRAFFIC, LOG_DEBUG, "Error decrypting packet from %s (%s)", n->name, n->hostname);
                        return;
                }
@@ -449,6 +486,9 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
 void receive_tcppacket(connection_t *c, const char *buffer, int len) {
        vpn_packet_t outpkt;
 
+       if(len > sizeof outpkt.data)
+               return;
+
        outpkt.len = len;
        if(c->options & OPTION_TCPONLY)
                outpkt.priority = 0;
@@ -464,7 +504,7 @@ static void send_sptps_packet(node_t *n, vpn_packet_t *origpkt) {
                logger(DEBUG_TRAFFIC, LOG_INFO, "No valid key known yet for %s (%s)", n->name, n->hostname);
                if(!n->status.waitingforkey)
                        send_req_key(n);
-               else if(n->last_req_key + 10 < time(NULL)) {
+               else if(n->last_req_key + 10 < now.tv_sec) {
                        logger(DEBUG_ALWAYS, LOG_DEBUG, "No key from %s after 10 seconds, restarting SPTPS", n->name);
                        sptps_stop(&n->sptps);
                        n->status.waitingforkey = false;
@@ -575,12 +615,22 @@ static void choose_broadcast_address(const node_t *n, const sockaddr_t **sa, int
        *sock = rand() % listen_sockets;
 
        if(listen_socket[*sock].sa.sa.sa_family == AF_INET6) {
-               broadcast_ipv6.in6.sin6_port = n->prevedge->address.in.sin_port;
-               broadcast_ipv6.in6.sin6_scope_id = listen_socket[*sock].sa.in6.sin6_scope_id;
-               *sa = &broadcast_ipv6;
+               if(localdiscovery_address.sa.sa_family == AF_INET6) {
+                       localdiscovery_address.in6.sin6_port = n->prevedge->address.in.sin_port;
+                       *sa = &localdiscovery_address;
+               } else {
+                       broadcast_ipv6.in6.sin6_port = n->prevedge->address.in.sin_port;
+                       broadcast_ipv6.in6.sin6_scope_id = listen_socket[*sock].sa.in6.sin6_scope_id;
+                       *sa = &broadcast_ipv6;
+               }
        } else {
-               broadcast_ipv4.in.sin_port = n->prevedge->address.in.sin_port;
-               *sa = &broadcast_ipv4;
+               if(localdiscovery_address.sa.sa_family == AF_INET) {
+                       localdiscovery_address.in.sin_port = n->prevedge->address.in.sin_port;
+                       *sa = &localdiscovery_address;
+               } else {
+                       broadcast_ipv4.in.sin_port = n->prevedge->address.in.sin_port;
+                       *sa = &broadcast_ipv4;
+               }
        }
 }
 
@@ -656,11 +706,11 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
 
        /* Encrypt the packet */
 
-       if(cipher_active(&n->outcipher)) {
+       if(cipher_active(n->outcipher)) {
                outpkt = pkt[nextpkt++];
                outlen = MAXSIZE;
 
-               if(!cipher_encrypt(&n->outcipher, &inpkt->seqno, inpkt->len, &outpkt->seqno, &outlen, true)) {
+               if(!cipher_encrypt(n->outcipher, &inpkt->seqno, inpkt->len, &outpkt->seqno, &outlen, true)) {
                        logger(DEBUG_TRAFFIC, LOG_ERR, "Error while encrypting packet to %s (%s)", n->name, n->hostname);
                        goto end;
                }
@@ -671,9 +721,13 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
 
        /* Add the message authentication code */
 
-       if(digest_active(&n->outdigest)) {
-               digest_create(&n->outdigest, &inpkt->seqno, inpkt->len, (char *)&inpkt->seqno + inpkt->len);
-               inpkt->len += digest_length(&n->outdigest);
+       if(digest_active(n->outdigest)) {
+               if(!digest_create(n->outdigest, &inpkt->seqno, inpkt->len, (char *)&inpkt->seqno + inpkt->len)) {
+                       logger(DEBUG_TRAFFIC, LOG_ERR, "Error while encrypting packet to %s (%s)", n->name, n->hostname);
+                       goto end;
+               }
+
+               inpkt->len += digest_length(n->outdigest);
        }
 
        /* Send the packet */
@@ -722,10 +776,12 @@ bool send_sptps_data(void *handle, uint8_t type, const char *data, size_t len) {
                b64encode(data, buf, len);
                /* If no valid key is known yet, send the packets using ANS_KEY requests,
                   to ensure we get to learn the reflexive UDP address. */
-               if(!to->status.validkey)
-                       return send_request(to->nexthop->connection, "%d %s %s %s -1 -1 -1 %d", ANS_KEY, myself->name, to->name, buf, myself->incompression);
-               else
+               if(!to->status.validkey) {
+                       to->incompression = myself->incompression;
+                       return send_request(to->nexthop->connection, "%d %s %s %s -1 -1 -1 %d", ANS_KEY, myself->name, to->name, buf, to->incompression);
+               } else {
                        return send_request(to->nexthop->connection, "%d %s %s %d %s", REQ_KEY, myself->name, to->name, REQ_SPTPS, buf);
+               }
        }
 
        /* Otherwise, send the packet via UDP */