Prepend source node ID information to UDP datagrams.
[tinc] / src / net_packet.c
index c8cd0ca..6b7c3b9 100644 (file)
@@ -182,7 +182,7 @@ static void mtu_probe_h(node_t *n, vpn_packet_t *packet, length_t len) {
                /* It's a probe request, send back a reply */
 
                /* Type 2 probe replies were introduced in protocol 17.3 */
-               if ((n->options >> 24) == 3) {
+               if ((n->options >> 24) >= 3) {
                        uint8_t* data = packet->data;
                        *data++ = 2;
                        uint16_t len16 = htons(len); memcpy(data, &len16, 2); data += 2;
@@ -356,7 +356,7 @@ static bool try_mac(node_t *n, const vpn_packet_t *inpkt) {
        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) {
+static bool receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
        vpn_packet_t pkt1, pkt2;
        vpn_packet_t *pkt[] = { &pkt1, &pkt2, &pkt1, &pkt2 };
        int nextpkt = 0;
@@ -370,15 +370,14 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
                        } else {
                                logger(DEBUG_TRAFFIC, LOG_DEBUG, "Got packet from %s (%s) but he hasn't got our key yet", n->name, n->hostname);
                        }
-                       return;
+                       return false;
                }
-               sptps_receive_data(&n->sptps, (char *)&inpkt->seqno, inpkt->len);
-               return;
+               return sptps_receive_data(&n->sptps, (char *)&inpkt->seqno, inpkt->len);
        }
 
        if(!n->status.validkey) {
                logger(DEBUG_TRAFFIC, LOG_DEBUG, "Got packet from %s (%s) but he hasn't got our key yet", n->name, n->hostname);
-               return;
+               return false;
        }
 
        /* Check packet length */
@@ -386,7 +385,7 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
        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;
+               return false;
        }
 
        /* Check the message authentication code */
@@ -395,7 +394,7 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
                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;
+                       return false;
                }
        }
        /* Decrypt the packet */
@@ -406,7 +405,7 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
 
                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;
+                       return false;
                }
 
                outpkt->len = outlen;
@@ -416,37 +415,39 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
        /* Check the sequence number */
 
        inpkt->len -= sizeof inpkt->seqno;
-       inpkt->seqno = ntohl(inpkt->seqno);
+       uint32_t seqno;
+       memcpy(&seqno, inpkt->seqno, sizeof seqno);
+       seqno = ntohl(seqno);
 
        if(replaywin) {
-               if(inpkt->seqno != n->received_seqno + 1) {
-                       if(inpkt->seqno >= n->received_seqno + replaywin * 8) {
+               if(seqno != n->received_seqno + 1) {
+                       if(seqno >= n->received_seqno + replaywin * 8) {
                                if(n->farfuture++ < replaywin >> 2) {
                                        logger(DEBUG_ALWAYS, LOG_WARNING, "Packet from %s (%s) is %d seqs in the future, dropped (%u)",
-                                               n->name, n->hostname, inpkt->seqno - n->received_seqno - 1, n->farfuture);
-                                       return;
+                                               n->name, n->hostname, seqno - n->received_seqno - 1, n->farfuture);
+                                       return false;
                                }
                                logger(DEBUG_ALWAYS, LOG_WARNING, "Lost %d packets from %s (%s)",
-                                               inpkt->seqno - n->received_seqno - 1, n->name, n->hostname);
+                                               seqno - n->received_seqno - 1, n->name, n->hostname);
                                memset(n->late, 0, replaywin);
-                       } else if (inpkt->seqno <= n->received_seqno) {
-                               if((n->received_seqno >= replaywin * 8 && inpkt->seqno <= n->received_seqno - replaywin * 8) || !(n->late[(inpkt->seqno / 8) % replaywin] & (1 << inpkt->seqno % 8))) {
+                       } else if (seqno <= n->received_seqno) {
+                               if((n->received_seqno >= replaywin * 8 && seqno <= n->received_seqno - replaywin * 8) || !(n->late[(seqno / 8) % replaywin] & (1 << seqno % 8))) {
                                        logger(DEBUG_ALWAYS, LOG_WARNING, "Got late or replayed packet from %s (%s), seqno %d, last received %d",
-                                               n->name, n->hostname, inpkt->seqno, n->received_seqno);
-                                       return;
+                                               n->name, n->hostname, seqno, n->received_seqno);
+                                       return false;
                                }
                        } else {
-                               for(int i = n->received_seqno + 1; i < inpkt->seqno; i++)
+                               for(int i = n->received_seqno + 1; i < seqno; i++)
                                        n->late[(i / 8) % replaywin] |= 1 << i % 8;
                        }
                }
 
                n->farfuture = 0;
-               n->late[(inpkt->seqno / 8) % replaywin] &= ~(1 << inpkt->seqno % 8);
+               n->late[(seqno / 8) % replaywin] &= ~(1 << seqno % 8);
        }
 
-       if(inpkt->seqno > n->received_seqno)
-               n->received_seqno = inpkt->seqno;
+       if(seqno > n->received_seqno)
+               n->received_seqno = seqno;
 
        n->received++;
 
@@ -463,7 +464,7 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
                if((outpkt->len = uncompress_packet(outpkt->data, inpkt->data, inpkt->len, n->incompression)) < 0) {
                        logger(DEBUG_TRAFFIC, LOG_ERR, "Error while uncompressing packet from %s (%s)",
                                                 n->name, n->hostname);
-                       return;
+                       return false;
                }
 
                inpkt = outpkt;
@@ -477,6 +478,7 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
                mtu_probe_h(n, inpkt, origlen);
        else
                receive_packet(n, inpkt);
+       return true;
 }
 
 void receive_tcppacket(connection_t *c, const char *buffer, int len) {
@@ -628,8 +630,8 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
        size_t outlen;
 #if defined(SOL_IP) && defined(IP_TOS)
        static int priority = 0;
-#endif
        int origpriority = origpkt->priority;
+#endif
 
        if(!n->status.reachable) {
                logger(DEBUG_TRAFFIC, LOG_INFO, "Trying to send UDP packet to unreachable node %s (%s)", n->name, n->hostname);
@@ -685,7 +687,8 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
 
        /* Add sequence number */
 
-       inpkt->seqno = htonl(++(n->sent_seqno));
+       uint32_t seqno = htonl(++(n->sent_seqno));
+       memcpy(inpkt->seqno, &seqno, sizeof inpkt->seqno);
        inpkt->len += sizeof inpkt->seqno;
 
        /* Encrypt the packet */
@@ -694,7 +697,7 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
                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;
                }
@@ -706,7 +709,7 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
        /* Add the message authentication code */
 
        if(digest_active(n->outdigest)) {
-               if(!digest_create(n->outdigest, &inpkt->seqno, inpkt->len, (char *)&inpkt->seqno + inpkt->len)) {
+               if(!digest_create(n->outdigest, inpkt->seqno, inpkt->len, inpkt->seqno + inpkt->len)) {
                        logger(DEBUG_TRAFFIC, LOG_ERR, "Error while encrypting packet to %s (%s)", n->name, n->hostname);
                        goto end;
                }
@@ -734,7 +737,7 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
        }
 #endif
 
-       if(sendto(listen_socket[sock].udp.fd, (char *) &inpkt->seqno, inpkt->len, 0, &sa->sa, SALEN(sa->sa)) < 0 && !sockwouldblock(sockerrno)) {
+       if(sendto(listen_socket[sock].udp.fd, inpkt->seqno, inpkt->len, 0, &sa->sa, SALEN(sa->sa)) < 0 && !sockwouldblock(sockerrno)) {
                if(sockmsgsize(sockerrno)) {
                        if(n->maxmtu >= origlen)
                                n->maxmtu = origlen - 1;
@@ -776,7 +779,17 @@ bool send_sptps_data(void *handle, uint8_t type, const char *data, size_t len) {
        if(!sa)
                choose_udp_address(to, &sa, &sock);
 
-       if(sendto(listen_socket[sock].udp.fd, data, len, 0, &sa->sa, SALEN(sa->sa)) < 0 && !sockwouldblock(sockerrno)) {
+       bool add_srcid = (to->options >> 24) >= 4;
+       size_t overhead = 0;
+       if (add_srcid) overhead += sizeof myself->id;
+       char buf[len + overhead]; char* buf_ptr = buf;
+       if(add_srcid) {
+               memcpy(buf_ptr, &myself->id, sizeof myself->id); buf_ptr += sizeof myself->id;
+       }
+       /* TODO: if this copy turns out to be a performance concern, change sptps_send_record() to add some "pre-padding" to the buffer and use that instead */
+       memcpy(buf_ptr, data, len); buf_ptr += len;
+
+       if(sendto(listen_socket[sock].udp.fd, buf, buf_ptr - buf, 0, &sa->sa, SALEN(sa->sa)) < 0 && !sockwouldblock(sockerrno)) {
                if(sockmsgsize(sockerrno)) {
                        // Compensate for SPTPS overhead
                        len -= SPTPS_DATAGRAM_OVERHEAD;
@@ -936,7 +949,7 @@ void broadcast_packet(const node_t *from, vpn_packet_t *packet) {
                // usually distributes the sending of broadcast packets over all nodes.
                case BMODE_MST:
                        for list_each(connection_t, c, connection_list)
-                               if(c->status.active && c->status.mst && c != from->nexthop->connection)
+                               if(c->edge && c->status.mst && c != from->nexthop->connection)
                                        send_packet(c->node, packet);
                        break;
 
@@ -992,10 +1005,10 @@ void handle_incoming_vpn_data(void *data, int flags) {
        char *hostname;
        sockaddr_t from = {{0}};
        socklen_t fromlen = sizeof from;
-       node_t *n;
+       node_t *n = NULL;
        int len;
 
-       len = recvfrom(ls->udp.fd, (char *) &pkt.seqno, MAXSIZE, 0, &from.sa, &fromlen);
+       len = recvfrom(ls->udp.fd, &pkt.srcid, MAXSIZE, 0, &from.sa, &fromlen);
 
        if(len <= 0 || len > MAXSIZE) {
                if(!sockwouldblock(sockerrno))
@@ -1007,25 +1020,34 @@ void handle_incoming_vpn_data(void *data, int flags) {
 
        sockaddrunmap(&from); /* Some braindead IPv6 implementations do stupid things. */
 
-       n = lookup_node_udp(&from);
+       if(len >= sizeof pkt.srcid)
+               n = lookup_node_id(&pkt.srcid);
+       if(n)
+               pkt.len -= sizeof pkt.srcid;
+       else {
+               /* Most likely an old-style packet without a source ID. */
+               memmove(pkt.seqno, &pkt.srcid, sizeof pkt - offsetof(vpn_packet_t, seqno));
+               n = lookup_node_udp(&from);
+       }
+
+       if(!n)
+               n = try_harder(&from, &pkt);
 
        if(!n) {
-               n = try_harder(&from, &pkt);
-               if(n)
-                       update_node_udp(n, &from);
-               else if(debug_level >= DEBUG_PROTOCOL) {
+               if(debug_level >= DEBUG_PROTOCOL) {
                        hostname = sockaddr2hostname(&from);
                        logger(DEBUG_PROTOCOL, LOG_WARNING, "Received UDP packet from unknown source %s", hostname);
                        free(hostname);
-                       return;
                }
-               else
-                       return;
+               return;
        }
 
-       n->sock = ls - listen_socket;
+       if(!receive_udppacket(n, &pkt))
+               return;
 
-       receive_udppacket(n, &pkt);
+       n->sock = ls - listen_socket;
+       if(sockaddrcmp(&from, &n->address))
+               update_node_udp(n, &from);
 }
 
 void handle_device_data(void *data, int flags) {