Replace the connection_tree with a connection_list.
[tinc] / src / net_packet.c
index 3627f31..c9a6663 100644 (file)
@@ -1,7 +1,7 @@
 /*
     net_packet.c -- Handles in- and outgoing VPN packets
     Copyright (C) 1998-2005 Ivo Timmermans,
-                  2000-2011 Guus Sliepen <guus@tinc-vpn.org>
+                  2000-2012 Guus Sliepen <guus@tinc-vpn.org>
                   2010      Timothy Redaelli <timothy@redaelli.eu>
                   2010      Brandon Black <blblack@gmail.com>
 
@@ -36,7 +36,6 @@
 #include LZO1X_H
 #endif
 
-#include "splay_tree.h"
 #include "cipher.h"
 #include "conf.h"
 #include "connection.h"
@@ -62,13 +61,21 @@ 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;
 
 #define MAX_SEQNO 1073741824
 
-// mtuprobes == 1..30: initial discovery, send bursts with 1 second interval
-// mtuprobes ==    31: sleep pinginterval seconds
-// mtuprobes ==    32: send 1 burst, sleep pingtimeout second
-// mtuprobes ==    33: no response from other side, restart PMTU discovery process
+/* mtuprobes == 1..30: initial discovery, send bursts with 1 second interval
+   mtuprobes ==    31: sleep pinginterval seconds
+   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.
+
+   In case local discovery is enabled, a fourth packet is added to each batch,
+   which will be broadcast to the local network.
+*/
 
 static void send_mtu_probe_handler(int fd, short events, void *data) {
        node_t *n = data;
@@ -79,7 +86,7 @@ static void send_mtu_probe_handler(int fd, short events, void *data) {
        n->mtuprobes++;
 
        if(!n->status.reachable || !n->status.validkey) {
-               ifdebug(TRAFFIC) logger(LOG_INFO, "Trying to send MTU probe to unreachable or rekeying node %s (%s)", n->name, n->hostname);
+               logger(DEBUG_TRAFFIC, LOG_INFO, "Trying to send MTU probe to unreachable or rekeying node %s (%s)", n->name, n->hostname);
                n->mtuprobes = 0;
                return;
        }
@@ -91,14 +98,14 @@ static void send_mtu_probe_handler(int fd, short events, void *data) {
                        goto end;
                }
 
-               ifdebug(TRAFFIC) logger(LOG_INFO, "%s (%s) did not respond to UDP ping, restarting PMTU discovery", n->name, n->hostname);
+               logger(DEBUG_TRAFFIC, LOG_INFO, "%s (%s) did not respond to UDP ping, restarting PMTU discovery", n->name, n->hostname);
                n->mtuprobes = 1;
                n->minmtu = 0;
                n->maxmtu = MTU;
        }
 
        if(n->mtuprobes >= 10 && n->mtuprobes < 32 && !n->minmtu) {
-               ifdebug(TRAFFIC) logger(LOG_INFO, "No response to MTU probes from %s (%s)", n->name, n->hostname);
+               logger(DEBUG_TRAFFIC, LOG_INFO, "No response to MTU probes from %s (%s)", n->name, n->hostname);
                n->mtuprobes = 31;
        }
 
@@ -108,7 +115,7 @@ static void send_mtu_probe_handler(int fd, short events, void *data) {
                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);
+               logger(DEBUG_TRAFFIC, LOG_INFO, "Fixing MTU of %s (%s) to %d after %d probes", n->name, n->hostname, n->mtu, n->mtuprobes);
                n->mtuprobes = 31;
        }
 
@@ -119,7 +126,7 @@ static void send_mtu_probe_handler(int fd, short events, void *data) {
                timeout = pingtimeout;
        }
 
-       for(i = 0; i < 3; i++) {
+       for(i = 0; i < 3 + localdiscovery; i++) {
                if(n->maxmtu <= n->minmtu)
                        len = n->maxmtu;
                else
@@ -131,9 +138,12 @@ static void send_mtu_probe_handler(int fd, short events, void *data) {
                memset(packet.data, 0, 14);
                randomize(packet.data + 14, len - 14);
                packet.len = len;
-               packet.priority = 0;
+               if(i >= 3 && n->mtuprobes <= 10)
+                       packet.priority = -1;
+               else
+                       packet.priority = 0;
 
-               ifdebug(TRAFFIC) logger(LOG_INFO, "Sending MTU probe length %d to %s (%s)", len, n->name, n->hostname);
+               logger(DEBUG_TRAFFIC, LOG_INFO, "Sending MTU probe length %d to %s (%s)", len, n->name, n->hostname);
 
                send_udppacket(n, &packet);
        }
@@ -149,7 +159,7 @@ void send_mtu_probe(node_t *n) {
 }
 
 static void mtu_probe_h(node_t *n, vpn_packet_t *packet, length_t len) {
-       ifdebug(TRAFFIC) logger(LOG_INFO, "Got MTU probe length %d from %s (%s)", packet->len, n->name, n->hostname);
+       logger(DEBUG_TRAFFIC, LOG_INFO, "Got MTU probe length %d from %s (%s)", packet->len, n->name, n->hostname);
 
        if(!packet->data[0]) {
                packet->data[0] = 1;
@@ -231,7 +241,7 @@ static length_t uncompress_packet(uint8_t *dest, const uint8_t *source, length_t
 /* VPN packet I/O */
 
 static void receive_packet(node_t *n, vpn_packet_t *packet) {
-       ifdebug(TRAFFIC) logger(LOG_DEBUG, "Received packet of %d bytes from %s (%s)",
+       logger(DEBUG_TRAFFIC, LOG_DEBUG, "Received packet of %d bytes from %s (%s)",
                           packet->len, n->name, n->hostname);
 
        n->in_packets++;
@@ -241,6 +251,9 @@ static void receive_packet(node_t *n, vpn_packet_t *packet) {
 }
 
 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))
                return false;
 
@@ -254,8 +267,13 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
        vpn_packet_t *outpkt = pkt[0];
        size_t outlen;
 
+       if(n->status.sptps) {
+               sptps_receive_data(&n->sptps, (char *)&inpkt->seqno, inpkt->len);
+               return;
+       }
+
        if(!cipher_active(&n->incipher)) {
-               ifdebug(TRAFFIC) logger(LOG_DEBUG, "Got packet from %s (%s) but he hasn't got our key yet",
+               logger(DEBUG_TRAFFIC, LOG_DEBUG, "Got packet from %s (%s) but he hasn't got our key yet",
                                        n->name, n->hostname);
                return;
        }
@@ -263,7 +281,7 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
        /* Check packet length */
 
        if(inpkt->len < sizeof inpkt->seqno + digest_length(&n->indigest)) {
-               ifdebug(TRAFFIC) logger(LOG_DEBUG, "Got too short packet from %s (%s)",
+               logger(DEBUG_TRAFFIC, LOG_DEBUG, "Got too short packet from %s (%s)",
                                        n->name, n->hostname);
                return;
        }
@@ -273,7 +291,7 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
        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)) {
-                       ifdebug(TRAFFIC) logger(LOG_DEBUG, "Got unauthenticated packet from %s (%s)", n->name, n->hostname);
+                       logger(DEBUG_TRAFFIC, LOG_DEBUG, "Got unauthenticated packet from %s (%s)", n->name, n->hostname);
                        return;
                }
        }
@@ -284,7 +302,7 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
                outlen = MAXSIZE;
 
                if(!cipher_decrypt(&n->incipher, &inpkt->seqno, inpkt->len, &outpkt->seqno, &outlen, true)) {
-                       ifdebug(TRAFFIC) logger(LOG_DEBUG, "Error decrypting packet from %s (%s)", n->name, n->hostname);
+                       logger(DEBUG_TRAFFIC, LOG_DEBUG, "Error decrypting packet from %s (%s)", n->name, n->hostname);
                        return;
                }
                
@@ -301,16 +319,16 @@ 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)",
+                                       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;
                                }
-                               logger(LOG_WARNING, "Lost %d packets from %s (%s)",
+                               logger(DEBUG_ALWAYS, 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) {
                                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",
+                                       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;
                                }
@@ -338,7 +356,7 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
                outpkt = pkt[nextpkt++];
 
                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)",
+                       logger(DEBUG_TRAFFIC, LOG_ERR, "Error while uncompressing packet from %s (%s)",
                                                 n->name, n->hostname);
                        return;
                }
@@ -369,6 +387,52 @@ void receive_tcppacket(connection_t *c, const char *buffer, int len) {
        receive_packet(c->node, &outpkt);
 }
 
+static void send_sptps_packet(node_t *n, vpn_packet_t *origpkt) {
+       if(!n->status.validkey) {
+               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)) {
+                       sptps_stop(&n->sptps);
+                       n->status.waitingforkey = false;
+                       send_req_key(n);
+               }
+               return;
+       }
+
+       uint8_t type = 0;
+       int offset = 0;
+
+       if(!(origpkt->data[12] | origpkt->data[13])) {
+               sptps_send_record(&n->sptps, PKT_PROBE, (char *)origpkt->data, origpkt->len);
+               return;
+       }
+
+       if(routing_mode == RMODE_ROUTER)
+               offset = 14;
+       else
+               type = PKT_MAC;
+
+       if(origpkt->len < offset)
+               return;
+
+       vpn_packet_t outpkt;
+
+       if(n->outcompression) {
+               int len = compress_packet(outpkt.data + offset, origpkt->data + offset, origpkt->len - offset, n->outcompression);
+               if(len < 0) {
+                       logger(DEBUG_TRAFFIC, LOG_ERR, "Error while compressing packet to %s (%s)", n->name, n->hostname);
+               } else if(len < origpkt->len - offset) {
+                       outpkt.len = len + offset;
+                       origpkt = &outpkt;
+                       type |= PKT_COMPRESSED;
+               }
+       }
+
+       sptps_send_record(&n->sptps, type, (char *)origpkt->data + offset, origpkt->len - offset);
+       return;
+}
+
 static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
        vpn_packet_t pkt1, pkt2;
        vpn_packet_t *pkt[] = { &pkt1, &pkt2, &pkt1, &pkt2 };
@@ -379,21 +443,23 @@ 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;
-       int origpriority = origpkt->priority;
 #endif
-       int sock;
+       int origpriority = origpkt->priority;
 
        if(!n->status.reachable) {
-               ifdebug(TRAFFIC) logger(LOG_INFO, "Trying to send UDP packet to unreachable node %s (%s)", n->name, n->hostname);
+               logger(DEBUG_TRAFFIC, LOG_INFO, "Trying to send UDP packet to unreachable node %s (%s)", n->name, n->hostname);
                return;
        }
 
+       if(n->status.sptps)
+               return send_sptps_packet(n, origpkt);
+
        /* Make sure we have a valid key */
 
        if(!n->status.validkey) {
                time_t now = time(NULL);
 
-               ifdebug(TRAFFIC) logger(LOG_INFO,
+               logger(DEBUG_TRAFFIC, LOG_INFO,
                                   "No valid key known yet for %s (%s), forwarding via TCP",
                                   n->name, n->hostname);
 
@@ -408,7 +474,7 @@ 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,
+               logger(DEBUG_TRAFFIC, LOG_INFO,
                                "Packet for %s (%s) larger than minimum MTU, forwarding via %s",
                                n->name, n->hostname, n != n->nexthop ? n->nexthop->name : "TCP");
 
@@ -426,7 +492,7 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
                outpkt = pkt[nextpkt++];
 
                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)",
+                       logger(DEBUG_TRAFFIC, LOG_ERR, "Error while compressing packet to %s (%s)",
                                   n->name, n->hostname);
                        return;
                }
@@ -446,7 +512,7 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
                outlen = MAXSIZE;
 
                if(!cipher_encrypt(&n->outcipher, &inpkt->seqno, inpkt->len, &outpkt->seqno, &outlen, true)) {
-                       ifdebug(TRAFFIC) logger(LOG_ERR, "Error while encrypting packet to %s (%s)", n->name, n->hostname);
+                       logger(DEBUG_TRAFFIC, LOG_ERR, "Error while encrypting packet to %s (%s)", n->name, n->hostname);
                        goto end;
                }
 
@@ -463,39 +529,178 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
 
        /* Determine which socket we have to use */
 
-       for(sock = 0; sock < listen_sockets; sock++)
-               if(n->address.sa.sa_family == listen_socket[sock].sa.sa.sa_family)
-                       break;
-
-       if(sock >= listen_sockets)
-               sock = 0;                               /* If none is available, just use the first and hope for the best. */
+       if(n->address.sa.sa_family != listen_socket[n->sock].sa.sa.sa_family) {
+               for(int sock = 0; sock < listen_sockets; sock++) {
+                       if(n->address.sa.sa_family == listen_socket[sock].sa.sa.sa_family) {
+                               n->sock = sock;
+                               break;
+                       }
+               }
+       }
 
        /* Send the packet */
 
+       struct sockaddr *sa;
+       socklen_t sl;
+       int sock;
+
+       /* 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;
+       } else {
+               if(origpriority == -1)
+                       origpriority = 0;
+
+               sa = &(n->address.sa);
+               sl = SALEN(n->address.sa);
+               sock = n->sock;
+       }
+
 #if defined(SOL_IP) && defined(IP_TOS)
        if(priorityinheritance && origpriority != priority
-          && listen_socket[sock].sa.sa.sa_family == AF_INET) {
+          && 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[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));
+               logger(DEBUG_TRAFFIC, 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(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setsockopt", strerror(errno));
        }
 #endif
 
-       if(sendto(listen_socket[sock].udp, (char *) &inpkt->seqno, inpkt->len, 0, &(n->address.sa), SALEN(n->address.sa)) < 0 && !sockwouldblock(sockerrno)) {
+       if(sendto(listen_socket[sock].udp, (char *) &inpkt->seqno, inpkt->len, 0, sa, sl) < 0 && !sockwouldblock(sockerrno)) {
                if(sockmsgsize(sockerrno)) {
                        if(n->maxmtu >= origlen)
                                n->maxmtu = origlen - 1;
                        if(n->mtu >= origlen)
                                n->mtu = origlen - 1;
                } else
-                       logger(LOG_ERR, "Error sending packet to %s (%s): %s", n->name, n->hostname, sockstrerror(sockerrno));
+                       logger(DEBUG_TRAFFIC, LOG_WARNING, "Error sending packet to %s (%s): %s", n->name, n->hostname, sockstrerror(sockerrno));
        }
 
 end:
        origpkt->len = origlen;
 }
 
+bool send_sptps_data(void *handle, uint8_t type, const char *data, size_t len) {
+       node_t *to = handle;
+
+       if(type >= SPTPS_HANDSHAKE
+                       || ((myself->options | to->options) & OPTION_TCPONLY)
+                       || (type != PKT_PROBE && len > to->minmtu)) {
+               char buf[len * 4 / 3 + 5];
+               b64encode(data, buf, len);
+               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
+                       return send_request(to->nexthop->connection, "%d %s %s %d %s", REQ_KEY, myself->name, to->name, type >= SPTPS_HANDSHAKE ? REQ_SPTPS : REQ_PACKET, buf);
+       }
+
+       /* Send the packet */
+
+       struct sockaddr *sa;
+       socklen_t sl;
+       int sock;
+
+       sa = &(to->address.sa);
+       sl = SALEN(to->address.sa);
+       sock = to->sock;
+
+       if(sendto(listen_socket[sock].udp, data, len, 0, sa, sl) < 0 && !sockwouldblock(sockerrno)) {
+               if(sockmsgsize(sockerrno)) {
+                       if(to->maxmtu >= len)
+                               to->maxmtu = len - 1;
+                       if(to->mtu >= len)
+                               to->mtu = len - 1;
+               } else {
+                       logger(DEBUG_TRAFFIC, LOG_WARNING, "Error sending UDP SPTPS packet to %s (%s): %s", to->name, to->hostname, sockstrerror(sockerrno));
+                       return false;
+               }
+       }
+
+       return true;
+}
+
+bool receive_sptps_record(void *handle, uint8_t type, const char *data, uint16_t len) {
+       node_t *from = handle;
+
+       if(type == SPTPS_HANDSHAKE) {
+               from->status.validkey = true;
+               from->status.waitingforkey = false;
+               logger(DEBUG_META, LOG_INFO, "SPTPS key exchange with %s (%s) succesful", from->name, from->hostname);
+               return true;
+       }
+
+       if(len > MTU) {
+               logger(DEBUG_ALWAYS, LOG_ERR, "Packet from %s (%s) larger than maximum supported size (%d > %d)", from->name, from->hostname, len, MTU);
+               return false;
+       }
+
+       vpn_packet_t inpkt;
+
+       if(type == PKT_PROBE) {
+               inpkt.len = len;
+               memcpy(inpkt.data, data, len);
+               mtu_probe_h(from, &inpkt, len);
+               return true;
+       }
+
+       if(type & ~(PKT_COMPRESSED | PKT_MAC)) {
+               logger(DEBUG_ALWAYS, LOG_ERR, "Unexpected SPTPS record type %d len %d from %s (%s)", type, len, from->name, from->hostname);
+               return false;
+       }
+
+       /* Check if we have the headers we need */
+       if(routing_mode != RMODE_ROUTER && !(type & PKT_MAC)) {
+               logger(DEBUG_TRAFFIC, LOG_ERR, "Received packet from %s (%s) without MAC header (maybe Mode is not set correctly)", from->name, from->hostname);
+               return false;
+       } else if(routing_mode == RMODE_ROUTER && (type & PKT_MAC)) {
+               logger(DEBUG_TRAFFIC, LOG_WARNING, "Received packet from %s (%s) with MAC header (maybe Mode is not set correctly)", from->name, from->hostname);
+       }
+
+       int offset = (type & PKT_MAC) ? 0 : 14;
+       if(type & PKT_COMPRESSED) {
+               len = uncompress_packet(inpkt.data + offset, (const uint8_t *)data, len, from->incompression);
+               if(len < 0) {
+                       return false;
+               } else {
+                       inpkt.len = len + offset;
+               }
+               if(inpkt.len > MAXSIZE)
+                       abort();
+       } else {
+               memcpy(inpkt.data + offset, data, len);
+               inpkt.len = len + offset;
+       }
+
+       /* Generate the Ethernet packet type if necessary */
+       if(offset) {
+               switch(inpkt.data[14] >> 4) {
+                       case 4:
+                               inpkt.data[12] = 0x08;
+                               inpkt.data[13] = 0x00;
+                               break;
+                       case 6:
+                               inpkt.data[12] = 0x86;
+                               inpkt.data[13] = 0xDD;
+                               break;
+                       default:
+                               logger(DEBUG_TRAFFIC, LOG_ERR,
+                                                  "Unknown IP version %d while reading packet from %s (%s)",
+                                                  inpkt.data[14] >> 4, from->name, from->hostname);
+                               return false;
+               }
+       }
+
+       receive_packet(from, &inpkt);
+       return true;
+}
+
 /*
   send a packet to the given vpn ip.
 */
@@ -507,15 +712,15 @@ void send_packet(node_t *n, vpn_packet_t *packet) {
                         memcpy(packet->data, mymac.x, ETH_ALEN);
                n->out_packets++;
                n->out_bytes += packet->len;
-               write_packet(packet);
+               devops.write(packet);
                return;
        }
 
-       ifdebug(TRAFFIC) logger(LOG_ERR, "Sending packet of %d bytes to %s (%s)",
+       logger(DEBUG_TRAFFIC, LOG_ERR, "Sending packet of %d bytes to %s (%s)",
                           packet->len, n->name, n->hostname);
 
        if(!n->status.reachable) {
-               ifdebug(TRAFFIC) logger(LOG_INFO, "Node %s (%s) is not reachable",
+               logger(DEBUG_TRAFFIC, LOG_INFO, "Node %s (%s) is not reachable",
                                   n->name, n->hostname);
                return;
        }
@@ -523,10 +728,15 @@ void send_packet(node_t *n, vpn_packet_t *packet) {
        n->out_packets++;
        n->out_bytes += packet->len;
 
+       if(n->status.sptps) {
+               send_sptps_packet(n, packet);
+               return;
+       }
+
        via = (packet->priority == -1 || n->via == myself) ? n->nexthop : n->via;
 
        if(via != n)
-               ifdebug(TRAFFIC) logger(LOG_INFO, "Sending packet to %s via %s (%s)",
+               logger(DEBUG_TRAFFIC, LOG_INFO, "Sending packet to %s via %s (%s)",
                           n->name, via->name, n->via->hostname);
 
        if(packet->priority == -1 || ((myself->options | via->options) & OPTION_TCPONLY)) {
@@ -539,26 +749,49 @@ void send_packet(node_t *n, vpn_packet_t *packet) {
 /* Broadcast a packet using the minimum spanning tree */
 
 void broadcast_packet(const node_t *from, vpn_packet_t *packet) {
-       splay_node_t *node;
-       connection_t *c;
+       // Always give ourself a copy of the packet.
+       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)
+               return;
 
-       ifdebug(TRAFFIC) logger(LOG_INFO, "Broadcasting packet of %d bytes from %s (%s)",
+       logger(DEBUG_TRAFFIC, LOG_INFO, "Broadcasting packet of %d bytes from %s (%s)",
                           packet->len, from->name, from->hostname);
 
-       if(from != myself) {
-               send_packet(myself, packet);
+       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(list_node_t *node = connection_list->head, *next; node; node = next) {
+                               next = node->next;
+                               connection_t *c = node->data;
+
+                               if(c->status.active && c->status.mst && c != from->nexthop->connection)
+                                       send_packet(c->node, packet);
+                       }
+                       break;
 
-               // In TunnelServer mode, do not forward broadcast packets.
-                // The MST might not be valid and create loops.
-               if(tunnelserver)
-                       return;
-       }
+               // 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 = connection_tree->head; node; node = node->next) {
-               c = node->data;
+                       for(splay_node_t *node = node_tree->head; node; node = node->next) {
+                               node_t *n = node->data;
 
-               if(c->status.active && c->status.mst && c != from->nexthop->connection)
-                       send_packet(c->node, packet);
+                               if(n->status.reachable && ((n->via == myself && n->nexthop == n) || n->via == n))
+                                       send_packet(n, packet);
+                       }
+                       break;
+
+               default:
+                       break;
        }
 }
 
@@ -570,15 +803,10 @@ static node_t *try_harder(const sockaddr_t *from, const vpn_packet_t *pkt) {
        static time_t last_hard_try = 0;
        time_t now = time(NULL);
 
-       if(last_hard_try == now)
-               return NULL;
-       else
-               last_hard_try = now;
-
        for(node = edge_weight_tree->head; node; node = node->next) {
                e = node->data;
 
-               if(e->to == myself)
+               if(!e->to->status.reachable || e->to == myself)
                        continue;
 
                if(sockaddrcmp_noport(from, &e->address)) {
@@ -597,13 +825,14 @@ static node_t *try_harder(const sockaddr_t *from, const vpn_packet_t *pkt) {
        if(hard)
                last_hard_try = now;
 
+       last_hard_try = now;
        return n;
 }
 
 void handle_incoming_vpn_data(int sock, short events, void *data) {
        vpn_packet_t pkt;
        char *hostname;
-       sockaddr_t from;
+       sockaddr_t from = {{0}};
        socklen_t fromlen = sizeof from;
        node_t *n;
        int len;
@@ -612,7 +841,7 @@ void handle_incoming_vpn_data(int sock, short events, void *data) {
 
        if(len <= 0 || len > MAXSIZE) {
                if(!sockwouldblock(sockerrno))
-                       logger(LOG_ERR, "Receiving packet failed: %s", sockstrerror(sockerrno));
+                       logger(DEBUG_ALWAYS, LOG_ERR, "Receiving packet failed: %s", sockstrerror(sockerrno));
                return;
        }
 
@@ -626,9 +855,9 @@ void handle_incoming_vpn_data(int sock, short events, void *data) {
                n = try_harder(&from, &pkt);
                if(n)
                        update_node_udp(n, &from);
-               else ifdebug(PROTOCOL) {
+               else if(debug_level >= DEBUG_PROTOCOL) {
                        hostname = sockaddr2hostname(&from);
-                       logger(LOG_WARNING, "Received UDP packet from unknown source %s", hostname);
+                       logger(DEBUG_PROTOCOL, LOG_WARNING, "Received UDP packet from unknown source %s", hostname);
                        free(hostname);
                        return;
                }
@@ -636,6 +865,8 @@ void handle_incoming_vpn_data(int sock, short events, void *data) {
                        return;
        }
 
+       n->sock = (intptr_t)data;
+
        receive_udppacket(n, &pkt);
 }
 
@@ -644,7 +875,7 @@ void handle_device_data(int sock, short events, void *data) {
 
        packet.priority = 0;
 
-       if(read_packet(&packet)) {
+       if(devops.read(&packet)) {
                myself->in_packets++;
                myself->in_bytes += packet.len;
                route(myself, &packet);