Reformat all code using astyle.
[tinc] / src / net_packet.c
index 43c8ce2..2a419ca 100644 (file)
@@ -1,7 +1,7 @@
 /*
     net_packet.c -- Handles in- and outgoing VPN packets
     Copyright (C) 1998-2005 Ivo Timmermans,
-                  2000-2012 Guus Sliepen <guus@tinc-vpn.org>
+                  2000-2016 Guus Sliepen <guus@tinc-vpn.org>
                   2010      Timothy Redaelli <timothy@redaelli.eu>
                   2010      Brandon Black <blblack@gmail.com>
 
@@ -70,18 +70,22 @@ bool localdiscovery = false;
    mtuprobes ==    32: send 1 burst, sleep pingtimeout second
    mtuprobes ==    33: no response from other side, restart PMTU discovery process
 
-   Probes are sent in batches of three, with random sizes between the lower and
-   upper boundaries for the MTU thus far discovered.
+   Probes are sent in batches of at least three, with random sizes between the
+   lower and upper boundaries for the MTU thus far discovered.
 
-   In case local discovery is enabled, a fourth packet is added to each batch,
+   After the initial discovery, a fourth packet is added to each batch with a
+   size larger than the currently known PMTU, to test if the PMTU has increased.
+
+   In case local discovery is enabled, another packet is added to each batch,
    which will be broadcast to the local network.
+
 */
 
 void send_mtu_probe(node_t *n) {
        vpn_packet_t packet;
        int len, i;
        int timeout = 1;
-       
+
        n->mtuprobes++;
        n->mtuevent = NULL;
 
@@ -110,10 +114,12 @@ void send_mtu_probe(node_t *n) {
        }
 
        if(n->mtuprobes == 30 || (n->mtuprobes < 30 && n->minmtu >= n->maxmtu)) {
-               if(n->minmtu > n->maxmtu)
+               if(n->minmtu > n->maxmtu) {
                        n->minmtu = n->maxmtu;
-               else
+               } else {
                        n->maxmtu = n->minmtu;
+               }
+
                n->mtu = n->minmtu;
                ifdebug(TRAFFIC) logger(LOG_INFO, "Fixing MTU of %s (%s) to %d after %d probes", n->name, n->hostname, n->mtu, n->mtuprobes);
                n->mtuprobes = 31;
@@ -126,22 +132,32 @@ void send_mtu_probe(node_t *n) {
                timeout = pingtimeout;
        }
 
-       for(i = 0; i < 3 + localdiscovery; i++) {
-               if(n->maxmtu <= n->minmtu)
+       for(i = 0; i < 4 + localdiscovery; i++) {
+               if(i == 0) {
+                       if(n->mtuprobes < 30 || n->maxmtu + 8 >= MTU) {
+                               continue;
+                       }
+
+                       len = n->maxmtu + 8;
+               } else if(n->maxmtu <= n->minmtu) {
                        len = n->maxmtu;
-               else
+               } else {
                        len = n->minmtu + 1 + rand() % (n->maxmtu - n->minmtu);
+               }
 
-               if(len < 64)
+               if(len < 64) {
                        len = 64;
-               
+               }
+
                memset(packet.data, 0, 14);
-               RAND_pseudo_bytes(packet.data + 14, len - 14);
+               RAND_bytes(packet.data + 14, len - 14);
                packet.len = len;
-               if(i >= 3 && n->mtuprobes <= 10)
+
+               if(i >= 4 && n->mtuprobes <= 10) {
                        packet.priority = -1;
-               else
+               } else {
                        packet.priority = 0;
+               }
 
                ifdebug(TRAFFIC) logger(LOG_INFO, "Sending MTU probe length %d to %s (%s)", len, n->name, n->hostname);
 
@@ -164,16 +180,27 @@ void mtu_probe_h(node_t *n, vpn_packet_t *packet, length_t len) {
                send_udppacket(n, packet);
        } else {
                if(n->mtuprobes > 30) {
-                       if(n->minmtu)
+                       if(len == n->maxmtu + 8) {
+                               ifdebug(TRAFFIC) logger(LOG_INFO, "Increase in PMTU to %s (%s) detected, restarting PMTU discovery", n->name, n->hostname);
+                               n->maxmtu = MTU;
+                               n->mtuprobes = 10;
+                               return;
+                       }
+
+                       if(n->minmtu) {
                                n->mtuprobes = 30;
-                       else
+                       } else {
                                n->mtuprobes = 1;
+                       }
                }
 
-               if(len > n->maxmtu)
+               if(len > n->maxmtu) {
                        len = n->maxmtu;
-               if(n->minmtu < len)
+               }
+
+               if(n->minmtu < len) {
                        n->minmtu = len;
+               }
        }
 }
 
@@ -192,9 +219,10 @@ static length_t compress_packet(uint8_t *dest, const uint8_t *source, length_t l
        } else if(level < 10) {
 #ifdef HAVE_ZLIB
                unsigned long destlen = MAXSIZE;
-               if(compress2(dest, &destlen, source, len, level) == Z_OK)
+
+               if(compress2(dest, &destlen, source, len, level) == Z_OK) {
                        return destlen;
-               else
+               else
 #endif
                        return -1;
        } else {
@@ -206,7 +234,7 @@ static length_t compress_packet(uint8_t *dest, const uint8_t *source, length_t l
                return -1;
 #endif
        }
-       
+
        return -1;
 }
 
@@ -217,20 +245,25 @@ static length_t uncompress_packet(uint8_t *dest, const uint8_t *source, length_t
        } else if(level > 9) {
 #ifdef HAVE_LZO
                lzo_uint lzolen = MAXSIZE;
-               if(lzo1x_decompress_safe(source, len, dest, &lzolen, NULL) == LZO_E_OK)
+
+               if(lzo1x_decompress_safe(source, len, dest, &lzolen, NULL) == LZO_E_OK) {
                        return lzolen;
-               else
+               else
 #endif
                        return -1;
        }
+
 #ifdef HAVE_ZLIB
        else {
                unsigned long destlen = MAXSIZE;
-               if(uncompress(dest, &destlen, source, len) == Z_OK)
+
+               if(uncompress(dest, &destlen, source, len) == Z_OK) {
                        return destlen;
-               else
+               } else {
                        return -1;
+               }
        }
+
 #endif
 
        return -1;
@@ -240,7 +273,7 @@ static length_t uncompress_packet(uint8_t *dest, const uint8_t *source, length_t
 
 static void receive_packet(node_t *n, vpn_packet_t *packet) {
        ifdebug(TRAFFIC) logger(LOG_DEBUG, "Received packet of %d bytes from %s (%s)",
-                          packet->len, n->name, n->hostname);
+                               packet->len, n->name, n->hostname);
 
        route(n, packet);
 }
@@ -248,26 +281,27 @@ static void receive_packet(node_t *n, vpn_packet_t *packet) {
 static bool try_mac(const node_t *n, const vpn_packet_t *inpkt) {
        unsigned char hmac[EVP_MAX_MD_SIZE];
 
-       if(!n->indigest || !n->inmaclength || !n->inkey || inpkt->len < sizeof inpkt->seqno + n->inmaclength)
+       if(!n->indigest || !n->inmaclength || !n->inkey || inpkt->len < sizeof(inpkt->seqno) + n->inmaclength) {
                return false;
+       }
 
        HMAC(n->indigest, n->inkey, n->inkeylength, (unsigned char *) &inpkt->seqno, inpkt->len - n->inmaclength, (unsigned char *)hmac, NULL);
 
-       return !memcmp(hmac, (char *) &inpkt->seqno + inpkt->len - n->inmaclength, n->inmaclength);
+       return !memcmp_constant_time(hmac, (char *) &inpkt->seqno + inpkt->len - n->inmaclength, n->inmaclength);
 }
 
 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];
+       vpn_packet_t *outpkt;
        int outlen, outpad;
        unsigned char hmac[EVP_MAX_MD_SIZE];
        int i;
 
        if(!n->inkey) {
                ifdebug(TRAFFIC) logger(LOG_DEBUG, "Got packet from %s (%s) but he hasn't got our key yet",
-                                       n->name, n->hostname);
+                                       n->name, n->hostname);
                return;
        }
 
@@ -275,7 +309,7 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
 
        if(inpkt->len < sizeof(inpkt->seqno) + n->inmaclength) {
                ifdebug(TRAFFIC) logger(LOG_DEBUG, "Got too short packet from %s (%s)",
-                                       n->name, n->hostname);
+                                       n->name, n->hostname);
                return;
        }
 
@@ -284,11 +318,11 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
        if(n->indigest && n->inmaclength) {
                inpkt->len -= n->inmaclength;
                HMAC(n->indigest, n->inkey, n->inkeylength,
-                        (unsigned char *) &inpkt->seqno, inpkt->len, (unsigned char *)hmac, NULL);
+                    (unsigned char *) &inpkt->seqno, inpkt->len, (unsigned char *)hmac, NULL);
 
-               if(memcmp(hmac, (char *) &inpkt->seqno + inpkt->len, n->inmaclength)) {
+               if(memcmp_constant_time(hmac, (char *) &inpkt->seqno + inpkt->len, n->inmaclength)) {
                        ifdebug(TRAFFIC) logger(LOG_DEBUG, "Got unauthenticated packet from %s (%s)",
-                                          n->name, n->hostname);
+                                               n->name, n->hostname);
                        return;
                }
        }
@@ -298,15 +332,15 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
        if(n->incipher) {
                outpkt = pkt[nextpkt++];
 
-               if(!EVP_DecryptInit_ex(&n->inctx, NULL, NULL, NULL, NULL)
-                               || !EVP_DecryptUpdate(&n->inctx, (unsigned char *) &outpkt->seqno, &outlen,
-                                       (unsigned char *) &inpkt->seqno, inpkt->len)
-                               || !EVP_DecryptFinal_ex(&n->inctx, (unsigned char *) &outpkt->seqno + outlen, &outpad)) {
+               if(!EVP_DecryptInit_ex(n->inctx, NULL, NULL, NULL, NULL)
+                               || !EVP_DecryptUpdate(n->inctx, (unsigned char *) &outpkt->seqno, &outlen,
+                                                     (unsigned char *) &inpkt->seqno, inpkt->len)
+                               || !EVP_DecryptFinal_ex(n->inctx, (unsigned char *) &outpkt->seqno + outlen, &outpad)) {
                        ifdebug(TRAFFIC) logger(LOG_DEBUG, "Error decrypting packet from %s (%s): %s",
-                                               n->name, n->hostname, ERR_error_string(ERR_get_error(), NULL));
+                                               n->name, n->hostname, ERR_error_string(ERR_get_error(), NULL));
                        return;
                }
-               
+
                outpkt->len = outlen + outpad;
                inpkt = outpkt;
        }
@@ -320,22 +354,24 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
                if(inpkt->seqno != n->received_seqno + 1) {
                        if(inpkt->seqno >= n->received_seqno + replaywin * 8) {
                                if(n->farfuture++ < replaywin >> 2) {
-                                       logger(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);
+                                       ifdebug(TRAFFIC) logger(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;
                                }
-                               logger(LOG_WARNING, "Lost %d packets from %s (%s)",
-                                               inpkt->seqno - n->received_seqno - 1, n->name, n->hostname);
+
+                               ifdebug(TRAFFIC) logger(LOG_WARNING, "Lost %d packets from %s (%s)",
+                                                       inpkt->seqno - n->received_seqno - 1, n->name, n->hostname);
                                memset(n->late, 0, replaywin);
-                       } else if (inpkt->seqno <= n->received_seqno) {
+                       } 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))) {
-                                       logger(LOG_WARNING, "Got late or replayed packet from %s (%s), seqno %d, last received %d",
-                                               n->name, n->hostname, inpkt->seqno, n->received_seqno);
+                                       ifdebug(TRAFFIC) logger(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;
                                }
                        } else {
-                               for(i = n->received_seqno + 1; i < inpkt->seqno; i++)
+                               for(i = n->received_seqno + 1; i < inpkt->seqno; i++) {
                                        n->late[(i / 8) % replaywin] |= 1 << i % 8;
+                               }
                        }
                }
 
@@ -343,11 +379,13 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
                n->late[(inpkt->seqno / 8) % replaywin] &= ~(1 << inpkt->seqno % 8);
        }
 
-       if(inpkt->seqno > n->received_seqno)
+       if(inpkt->seqno > n->received_seqno) {
                n->received_seqno = inpkt->seqno;
-                       
-       if(n->received_seqno > MAX_SEQNO)
+       }
+
+       if(n->received_seqno > MAX_SEQNO) {
                keyexpires = 0;
+       }
 
        /* Decompress the packet */
 
@@ -358,31 +396,39 @@ 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) {
                        ifdebug(TRAFFIC) logger(LOG_ERR, "Error while uncompressing packet from %s (%s)",
-                                                n->name, n->hostname);
+                                               n->name, n->hostname);
                        return;
                }
 
                inpkt = outpkt;
 
-               origlen -= MTU/64 + 20;
+               origlen -= MTU / 64 + 20;
        }
 
        inpkt->priority = 0;
 
-       if(!inpkt->data[12] && !inpkt->data[13])
+       if(!inpkt->data[12] && !inpkt->data[13]) {
                mtu_probe_h(n, inpkt, origlen);
-       else
+       } else {
                receive_packet(n, 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)
+
+       if(c->options & OPTION_TCPONLY) {
                outpkt.priority = 0;
-       else
+       } else {
                outpkt.priority = -1;
+       }
+
        memcpy(outpkt.data, buffer, len);
 
        receive_packet(c->node, &outpkt);
@@ -396,9 +442,6 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
        vpn_packet_t *outpkt;
        int origlen;
        int outlen, outpad;
-#if defined(SOL_IP) && defined(IP_TOS)
-       static int priority = 0;
-#endif
        int origpriority;
 
        if(!n->status.reachable) {
@@ -410,8 +453,8 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
 
        if(!n->status.validkey) {
                ifdebug(TRAFFIC) logger(LOG_INFO,
-                                  "No valid key known yet for %s (%s), forwarding via TCP",
-                                  n->name, n->hostname);
+                                       "No valid key known yet for %s (%s), forwarding via TCP",
+                                       n->name, n->hostname);
 
                if(n->last_req_key + 10 <= now) {
                        send_req_key(n);
@@ -425,13 +468,14 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
 
        if(n->options & OPTION_PMTU_DISCOVERY && inpkt->len > n->minmtu && (inpkt->data[12] | inpkt->data[13])) {
                ifdebug(TRAFFIC) logger(LOG_INFO,
-                               "Packet for %s (%s) larger than minimum MTU, forwarding via %s",
-                               n->name, n->hostname, n != n->nexthop ? n->nexthop->name : "TCP");
+                                       "Packet for %s (%s) larger than minimum MTU, forwarding via %s",
+                                       n->name, n->hostname, n != n->nexthop ? n->nexthop->name : "TCP");
 
-               if(n != n->nexthop)
+               if(n != n->nexthop) {
                        send_packet(n->nexthop, origpkt);
-               else
+               } else {
                        send_tcppacket(n->nexthop->connection, origpkt);
+               }
 
                return;
        }
@@ -446,7 +490,7 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
 
                if((outpkt->len = compress_packet(outpkt->data, inpkt->data, inpkt->len, n->outcompression)) < 0) {
                        ifdebug(TRAFFIC) logger(LOG_ERR, "Error while compressing packet to %s (%s)",
-                                  n->name, n->hostname);
+                                               n->name, n->hostname);
                        return;
                }
 
@@ -463,12 +507,12 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
        if(n->outcipher) {
                outpkt = pkt[nextpkt++];
 
-               if(!EVP_EncryptInit_ex(&n->outctx, NULL, NULL, NULL, NULL)
-                               || !EVP_EncryptUpdate(&n->outctx, (unsigned char *) &outpkt->seqno, &outlen,
-                                       (unsigned char *) &inpkt->seqno, inpkt->len)
-                               || !EVP_EncryptFinal_ex(&n->outctx, (unsigned char *) &outpkt->seqno + outlen, &outpad)) {
+               if(!EVP_EncryptInit_ex(n->outctx, NULL, NULL, NULL, NULL)
+                               || !EVP_EncryptUpdate(n->outctx, (unsigned char *) &outpkt->seqno, &outlen,
+                                                     (unsigned char *) &inpkt->seqno, inpkt->len)
+                               || !EVP_EncryptFinal_ex(n->outctx, (unsigned char *) &outpkt->seqno + outlen, &outpad)) {
                        ifdebug(TRAFFIC) logger(LOG_ERR, "Error while encrypting packet to %s (%s): %s",
-                                               n->name, n->hostname, ERR_error_string(ERR_get_error(), NULL));
+                                               n->name, n->hostname, ERR_error_string(ERR_get_error(), NULL));
                        goto end;
                }
 
@@ -480,7 +524,7 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
 
        if(n->outdigest && n->outmaclength) {
                HMAC(n->outdigest, n->outkey, n->outkeylength, (unsigned char *) &inpkt->seqno,
-                        inpkt->len, (unsigned char *) &inpkt->seqno + inpkt->len, NULL);
+                    inpkt->len, (unsigned char *) &inpkt->seqno + inpkt->len, NULL);
                inpkt->len += n->outmaclength;
        }
 
@@ -500,44 +544,83 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
        struct sockaddr *sa;
        socklen_t sl;
        int sock;
+       sockaddr_t broadcast;
 
        /* Overloaded use of priority field: -1 means local broadcast */
 
        if(origpriority == -1 && n->prevedge) {
-               struct sockaddr_in in;
-               in.sin_family = AF_INET;
-               in.sin_addr.s_addr = -1;
-               in.sin_port = n->prevedge->address.in.sin_port;
-               sa = (struct sockaddr *)&in;
-               sl = sizeof in;
-               sock = 0;
+               sock = rand() % listen_sockets;
+               memset(&broadcast, 0, sizeof(broadcast));
+
+               if(listen_socket[sock].sa.sa.sa_family == AF_INET6) {
+                       broadcast.in6.sin6_family = AF_INET6;
+                       broadcast.in6.sin6_addr.s6_addr[0x0] = 0xff;
+                       broadcast.in6.sin6_addr.s6_addr[0x1] = 0x02;
+                       broadcast.in6.sin6_addr.s6_addr[0xf] = 0x01;
+                       broadcast.in6.sin6_port = n->prevedge->address.in.sin_port;
+                       broadcast.in6.sin6_scope_id = listen_socket[sock].sa.in6.sin6_scope_id;
+               } else {
+                       broadcast.in.sin_family = AF_INET;
+                       broadcast.in.sin_addr.s_addr = -1;
+                       broadcast.in.sin_port = n->prevedge->address.in.sin_port;
+               }
+
+               sa = &broadcast.sa;
+               sl = SALEN(broadcast.sa);
        } else {
-               if(origpriority == -1)
+               if(origpriority == -1) {
                        origpriority = 0;
+               }
 
                sa = &(n->address.sa);
                sl = SALEN(n->address.sa);
                sock = n->sock;
        }
 
+       if(priorityinheritance && origpriority != listen_socket[n->sock].priority) {
+               listen_socket[n->sock].priority = origpriority;
+
+               switch(listen_socket[n->sock].sa.sa.sa_family) {
 #if defined(SOL_IP) && defined(IP_TOS)
-       if(priorityinheritance && origpriority != priority
-          && listen_socket[n->sock].sa.sa.sa_family == AF_INET) {
-               priority = origpriority;
-               ifdebug(TRAFFIC) logger(LOG_DEBUG, "Setting outgoing packet priority to %d", priority);
-               if(setsockopt(listen_socket[n->sock].udp, SOL_IP, IP_TOS, &priority, sizeof(priority))) /* SO_PRIORITY doesn't seem to work */
-                       logger(LOG_ERR, "System call `%s' failed: %s", "setsockopt", strerror(errno));
-       }
+
+               case AF_INET:
+                       ifdebug(TRAFFIC) logger(LOG_DEBUG, "Setting IPv4 outgoing packet priority to %d", origpriority);
+
+                       if(setsockopt(listen_socket[n->sock].udp, SOL_IP, IP_TOS, (void *)&origpriority, sizeof(origpriority))) { /* SO_PRIORITY doesn't seem to work */
+                               logger(LOG_ERR, "System call `%s' failed: %s", "setsockopt", strerror(errno));
+                       }
+
+                       break;
+#endif
+#if defined(IPPROTO_IPV6) && defined(IPV6_TCLASS)
+
+               case AF_INET6:
+                       ifdebug(TRAFFIC) logger(LOG_DEBUG, "Setting IPv6 outgoing packet priority to %d", origpriority);
+
+                       if(setsockopt(listen_socket[n->sock].udp, IPPROTO_IPV6, IPV6_TCLASS, (void *)&origpriority, sizeof(origpriority))) {
+                               logger(LOG_ERR, "System call `%s' failed: %s", "setsockopt", strerror(errno));
+                       }
+
+                       break;
 #endif
 
+               default:
+                       break;
+               }
+       }
+
        if(sendto(listen_socket[sock].udp, (char *) &inpkt->seqno, inpkt->len, 0, sa, sl) < 0 && !sockwouldblock(sockerrno)) {
                if(sockmsgsize(sockerrno)) {
-                       if(n->maxmtu >= origlen)
+                       if(n->maxmtu >= origlen) {
                                n->maxmtu = origlen - 1;
-                       if(n->mtu >= origlen)
+                       }
+
+                       if(n->mtu >= origlen) {
                                n->mtu = origlen - 1;
-               } else
+                       }
+               } else {
                        ifdebug(TRAFFIC) logger(LOG_WARNING, "Error sending packet to %s (%s): %s", n->name, n->hostname, sockstrerror(sockerrno));
+               }
        }
 
 end:
@@ -551,18 +634,20 @@ void send_packet(const node_t *n, vpn_packet_t *packet) {
        node_t *via;
 
        if(n == myself) {
-               if(overwrite_mac)
-                        memcpy(packet->data, mymac.x, ETH_ALEN);
+               if(overwrite_mac) {
+                       memcpy(packet->data, mymac.x, ETH_ALEN);
+               }
+
                devops.write(packet);
                return;
        }
 
        ifdebug(TRAFFIC) logger(LOG_ERR, "Sending packet of %d bytes to %s (%s)",
-                          packet->len, n->name, n->hostname);
+                               packet->len, n->name, n->hostname);
 
        if(!n->status.reachable) {
                ifdebug(TRAFFIC) logger(LOG_INFO, "Node %s (%s) is not reachable",
-                                  n->name, n->hostname);
+                                       n->name, n->hostname);
                return;
        }
 
@@ -570,13 +655,15 @@ void send_packet(const node_t *n, vpn_packet_t *packet) {
 
        if(via != n)
                ifdebug(TRAFFIC) logger(LOG_INFO, "Sending packet to %s via %s (%s)",
-                          n->name, via->name, n->via->hostname);
+                                       n->name, via->name, n->via->hostname);
 
        if(packet->priority == -1 || ((myself->options | via->options) & OPTION_TCPONLY)) {
-               if(!send_tcppacket(via->connection, packet))
+               if(!send_tcppacket(via->connection, packet)) {
                        terminate_connection(via->connection, true);
-       } else
+               }
+       } else {
                send_udppacket(via, packet);
+       }
 }
 
 /* Broadcast a packet using the minimum spanning tree */
@@ -587,47 +674,54 @@ void broadcast_packet(const node_t *from, vpn_packet_t *packet) {
        node_t *n;
 
        // Always give ourself a copy of the packet.
-       if(from != myself)
+       if(from != myself) {
                send_packet(myself, packet);
+       }
 
        // In TunnelServer mode, do not forward broadcast packets.
-        // The MST might not be valid and create loops.
-       if(tunnelserver || broadcast_mode == BMODE_NONE)
+       // The MST might not be valid and create loops.
+       if(tunnelserver || broadcast_mode == BMODE_NONE) {
                return;
+       }
 
        ifdebug(TRAFFIC) logger(LOG_INFO, "Broadcasting packet of %d bytes from %s (%s)",
-                          packet->len, from->name, from->hostname);
+                               packet->len, from->name, from->hostname);
 
        switch(broadcast_mode) {
-               // In MST mode, broadcast packets travel via the Minimum Spanning Tree.
-               // This guarantees all nodes receive the broadcast packet, and
-               // usually distributes the sending of broadcast packets over all nodes.
-               case BMODE_MST:
-                       for(node = connection_tree->head; node; node = node->next) {
-                               c = node->data;
-
-                               if(c->status.active && c->status.mst && c != from->nexthop->connection)
-                                       send_packet(c->node, packet);
+       // In MST mode, broadcast packets travel via the Minimum Spanning Tree.
+       // This guarantees all nodes receive the broadcast packet, and
+       // usually distributes the sending of broadcast packets over all nodes.
+       case BMODE_MST:
+               for(node = connection_tree->head; node; node = node->next) {
+                       c = node->data;
+
+                       if(c->status.active && c->status.mst && c != from->nexthop->connection) {
+                               send_packet(c->node, packet);
                        }
-                       break;
+               }
 
-               // In direct mode, we send copies to each node we know of.
-               // However, this only reaches nodes that can be reached in a single hop.
-               // We don't have enough information to forward broadcast packets in this case.
-               case BMODE_DIRECT:
-                       if(from != myself)
-                               break;
+               break;
 
-                       for(node = node_udp_tree->head; node; node = node->next) {
-                               n = node->data;
+       // In direct mode, we send copies to each node we know of.
+       // However, this only reaches nodes that can be reached in a single hop.
+       // We don't have enough information to forward broadcast packets in this case.
+       case BMODE_DIRECT:
+               if(from != myself) {
+                       break;
+               }
+
+               for(node = node_udp_tree->head; node; node = node->next) {
+                       n = node->data;
 
-                               if(n->status.reachable && ((n->via == myself && n->nexthop == n) || n->via == n))
-                                       send_packet(c->node, packet);
+                       if(n->status.reachable && n != myself && ((n->via == myself && n->nexthop == n) || n->via == n)) {
+                               send_packet(n, packet);
                        }
-                       break;
+               }
 
-               default:
-                       break;
+               break;
+
+       default:
+               break;
        }
 }
 
@@ -635,31 +729,27 @@ static node_t *try_harder(const sockaddr_t *from, const vpn_packet_t *pkt) {
        avl_node_t *node;
        edge_t *e;
        node_t *n = NULL;
-       bool hard = false;
        static time_t last_hard_try = 0;
 
        for(node = edge_weight_tree->head; node; node = node->next) {
                e = node->data;
 
-               if(e->to == myself)
+               if(e->to == myself) {
                        continue;
+               }
 
-               if(sockaddrcmp_noport(from, &e->address)) {
-                       if(last_hard_try == now)
-                               continue;
-                       hard = true;
+               if(last_hard_try == now && sockaddrcmp_noport(from, &e->address)) {
+                       continue;
                }
 
-               if(!try_mac(e->to, pkt))
+               if(!try_mac(e->to, pkt)) {
                        continue;
+               }
 
                n = e->to;
                break;
        }
 
-       if(hard)
-               last_hard_try = now;
-
        last_hard_try = now;
        return n;
 }
@@ -674,27 +764,30 @@ void handle_incoming_vpn_data(int sock) {
        pkt.len = recvfrom(listen_socket[sock].udp, (char *) &pkt.seqno, MAXSIZE, 0, &from.sa, &fromlen);
 
        if(pkt.len < 0) {
-               if(!sockwouldblock(sockerrno))
+               if(!sockwouldblock(sockerrno)) {
                        logger(LOG_ERR, "Receiving packet failed: %s", sockstrerror(sockerrno));
+               }
+
                return;
        }
 
-       sockaddrunmap(&from);           /* Some braindead IPv6 implementations do stupid things. */
+       sockaddrunmap(&from);           /* Some braindead IPv6 implementations do stupid things. */
 
        n = lookup_node_udp(&from);
 
        if(!n) {
                n = try_harder(&from, &pkt);
-               if(n)
+
+               if(n) {
                        update_node_udp(n, &from);
-               else ifdebug(PROTOCOL) {
+               else ifdebug(PROTOCOL) {
                        hostname = sockaddr2hostname(&from);
                        logger(LOG_WARNING, "Received UDP packet from unknown source %s", hostname);
                        free(hostname);
                        return;
-               }
-               else
+               } else {
                        return;
+               }
        }
 
        n->sock = sock;