Change vpn_packet_t::seqno from uint32_t to uint8_t[4].
[tinc] / src / net_packet.c
index 1254e48..67407dc 100644 (file)
@@ -42,7 +42,6 @@
 #include "net.h"
 #include "netutl.h"
 #include "protocol.h"
-#include "process.h"
 #include "route.h"
 #include "utils.h"
 #include "xalloc.h"
@@ -55,8 +54,7 @@ static char lzo_wrkmem[LZO1X_999_MEM_COMPRESS > LZO1X_1_MEM_COMPRESS ? LZO1X_999
 static void send_udppacket(node_t *, vpn_packet_t *);
 
 unsigned replaywin = 16;
-bool localdiscovery = false;
-sockaddr_t localdiscovery_address;
+bool localdiscovery = true;
 
 #define MAX_SEQNO 1073741824
 
@@ -144,16 +142,15 @@ static void send_mtu_probe_handler(void *data) {
                memset(packet.data, 0, 14);
                randomize(packet.data + 14, len - 14);
                packet.len = len;
-               if(i >= 4 && n->mtuprobes <= 10)
-                       packet.priority = -1;
-               else
-                       packet.priority = 0;
+               packet.priority = 0;
+               n->status.send_locally = i >= 4 && n->mtuprobes <= 10 && n->prevedge;
 
                logger(DEBUG_TRAFFIC, LOG_INFO, "Sending MTU probe length %d to %s (%s)", len, n->name, n->hostname);
 
                send_udppacket(n, &packet);
        }
 
+       n->status.send_locally = false;
        n->probe_counter = 0;
        gettimeofday(&n->probe_time, NULL);
 
@@ -185,7 +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;
@@ -363,7 +360,6 @@ static void 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;
-       vpn_packet_t *outpkt = pkt[0];
        size_t outlen;
 
        if(n->status.sptps) {
@@ -380,7 +376,7 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
                return;
        }
 
-       if(!cipher_active(n->incipher)) {
+       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;
        }
@@ -405,7 +401,7 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
        /* Decrypt the packet */
 
        if(cipher_active(n->incipher)) {
-               outpkt = pkt[nextpkt++];
+               vpn_packet_t *outpkt = pkt[nextpkt++];
                outlen = MAXSIZE;
 
                if(!cipher_decrypt(n->incipher, &inpkt->seqno, inpkt->len, &outpkt->seqno, &outlen, true)) {
@@ -420,37 +416,39 @@ 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);
+                                               n->name, n->hostname, seqno - n->received_seqno - 1, n->farfuture);
                                        return;
                                }
                                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);
+                                               n->name, n->hostname, seqno, n->received_seqno);
                                        return;
                                }
                        } 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++;
 
@@ -462,7 +460,7 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
        length_t origlen = inpkt->len;
 
        if(n->incompression) {
-               outpkt = pkt[nextpkt++];
+               vpn_packet_t *outpkt = pkt[nextpkt++];
 
                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)",
@@ -546,6 +544,18 @@ static void send_sptps_packet(node_t *n, vpn_packet_t *origpkt) {
        return;
 }
 
+static void adapt_socket(const sockaddr_t *sa, int *sock) {
+       /* Make sure we have a suitable socket for the chosen address */
+       if(listen_socket[*sock].sa.sa.sa_family != sa->sa.sa_family) {
+               for(int i = 0; i < listen_sockets; i++) {
+                       if(listen_socket[i].sa.sa.sa_family == sa->sa.sa_family) {
+                               *sock = i;
+                               break;
+                       }
+               }
+       }
+}
+
 static void choose_udp_address(const node_t *n, const sockaddr_t **sa, int *sock) {
        /* Latest guess */
        *sa = &n->address;
@@ -584,54 +594,30 @@ static void choose_udp_address(const node_t *n, const sockaddr_t **sa, int *sock
                *sock = rand() % listen_sockets;
        }
 
-       /* Make sure we have a suitable socket for the chosen address */
-       if(listen_socket[*sock].sa.sa.sa_family != (*sa)->sa.sa_family) {
-               for(int i = 0; i < listen_sockets; i++) {
-                       if(listen_socket[i].sa.sa.sa_family == (*sa)->sa.sa_family) {
-                               *sock = i;
-                               break;
-                       }
-               }
-       }
+       adapt_socket(*sa, sock);
 }
 
-static void choose_broadcast_address(const node_t *n, const sockaddr_t **sa, int *sock) {
-       static sockaddr_t broadcast_ipv4 = {
-               .in = {
-                       .sin_family = AF_INET,
-                       .sin_addr.s_addr = -1,
-               }
-       };
-
-       static sockaddr_t broadcast_ipv6 = {
-               .in6 = {
-                       .sin6_family = AF_INET6,
-                       .sin6_addr.s6_addr[0x0] = 0xff,
-                       .sin6_addr.s6_addr[0x1] = 0x02,
-                       .sin6_addr.s6_addr[0xf] = 0x01,
-               }
-       };
+static void choose_local_address(const node_t *n, const sockaddr_t **sa, int *sock) {
+       *sa = NULL;
 
-       *sock = rand() % listen_sockets;
+       /* Pick one of the edges from this node at random, then use its local address. */
 
-       if(listen_socket[*sock].sa.sa.sa_family == AF_INET6) {
-               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 {
-               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;
+       int i = 0;
+       int j = rand() % n->edge_tree->count;
+       edge_t *candidate = NULL;
+
+       for splay_each(edge_t, e, n->edge_tree) {
+               if(i++ == j) {
+                       candidate = e;
+                       break;
                }
        }
+
+       if (candidate && candidate->local_address.sa.sa_family) {
+               *sa = &candidate->local_address;
+               *sock = rand() % listen_sockets;
+               adapt_socket(*sa, sock);
+       }
 }
 
 static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
@@ -644,8 +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);
@@ -701,7 +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 */
@@ -710,7 +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;
                }
@@ -722,7 +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;
                }
@@ -732,14 +719,12 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
 
        /* Send the packet */
 
-       const sockaddr_t *sa;
+       const sockaddr_t *sa = NULL;
        int sock;
 
-       /* Overloaded use of priority field: -1 means local broadcast */
-
-       if(origpriority == -1 && n->prevedge)
-               choose_broadcast_address(n, &sa, &sock);
-       else
+       if(n->status.send_locally)
+               choose_local_address(n, &sa, &sock);
+       if(!sa)
                choose_udp_address(n, &sa, &sock);
 
 #if defined(SOL_IP) && defined(IP_TOS)
@@ -748,11 +733,11 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
                priority = origpriority;
                logger(DEBUG_TRAFFIC, LOG_DEBUG, "Setting outgoing packet priority to %d", priority);
                if(setsockopt(listen_socket[n->sock].udp.fd, SOL_IP, IP_TOS, &priority, sizeof(priority))) /* SO_PRIORITY doesn't seem to work */
-                       logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setsockopt", strerror(errno));
+                       logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setsockopt", sockstrerror(sockerrno));
        }
 #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;
@@ -771,26 +756,33 @@ bool send_sptps_data(void *handle, uint8_t type, const char *data, size_t len) {
 
        /* Send it via TCP if it is a handshake packet, TCPOnly is in use, or this packet is larger than the MTU. */
 
-       if(type >= SPTPS_HANDSHAKE || ((myself->options | to->options) & OPTION_TCPONLY) || (type != PKT_PROBE && len > to->minmtu)) {
+       if(type >= SPTPS_HANDSHAKE || ((myself->options | to->options) & OPTION_TCPONLY) || (type != PKT_PROBE && (len - SPTPS_DATAGRAM_OVERHEAD) > to->minmtu)) {
                char buf[len * 4 / 3 + 5];
                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 */
 
-       const sockaddr_t *sa;
+       const sockaddr_t *sa = NULL;
        int sock;
 
-       choose_udp_address(to, &sa, &sock);
+       if(to->status.send_locally)
+               choose_local_address(to, &sa, &sock);
+       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)) {
                if(sockmsgsize(sockerrno)) {
+                       // Compensate for SPTPS overhead
+                       len -= SPTPS_DATAGRAM_OVERHEAD;
                        if(to->maxmtu >= len)
                                to->maxmtu = len - 1;
                        if(to->mtu >= len)
@@ -947,7 +939,7 @@ 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;
 
@@ -959,7 +951,7 @@ void broadcast_packet(const node_t *from, vpn_packet_t *packet) {
                                break;
 
                        for splay_each(node_t, n, node_tree)
-                               if(n->status.reachable && ((n->via == myself && n->nexthop == n) || n->via == n))
+                               if(n->status.reachable && n != myself && ((n->via == myself && n->nexthop == n) || n->via == n))
                                        send_packet(n, packet);
                        break;
 
@@ -1006,7 +998,7 @@ void handle_incoming_vpn_data(void *data, int flags) {
        node_t *n;
        int len;
 
-       len = recvfrom(ls->udp.fd, (char *) &pkt.seqno, MAXSIZE, 0, &from.sa, &fromlen);
+       len = recvfrom(ls->udp.fd, pkt.seqno, MAXSIZE, 0, &from.sa, &fromlen);
 
        if(len <= 0 || len > MAXSIZE) {
                if(!sockwouldblock(sockerrno))