Introducing the Big Tinc Lock.
[tinc] / src / net_packet.c
index 05336b0..a985390 100644 (file)
@@ -1,7 +1,9 @@
 /*
     net_packet.c -- Handles in- and outgoing VPN packets
     Copyright (C) 1998-2005 Ivo Timmermans,
-                  2000-2009 Guus Sliepen <guus@tinc-vpn.org>
+                  2000-2010 Guus Sliepen <guus@tinc-vpn.org>
+                  2010      Timothy Redaelli <timothy@redaelli.eu>
+                  2010      Brandon Black <blblack@gmail.com>
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
 #include <openssl/pem.h>
 #include <openssl/hmac.h>
 
+#ifdef HAVE_ZLIB
 #include <zlib.h>
+#endif
+
+#ifdef HAVE_LZO
 #include LZO1X_H
+#endif
 
-#include "avl_tree.h"
+#include "splay_tree.h"
+#include "cipher.h"
 #include "conf.h"
 #include "connection.h"
+#include "crypto.h"
+#include "digest.h"
 #include "device.h"
 #include "ethernet.h"
-#include "event.h"
 #include "graph.h"
 #include "list.h"
 #include "logger.h"
 #include "utils.h"
 #include "xalloc.h"
 
-#ifdef WSAEMSGSIZE
-#define EMSGSIZE WSAEMSGSIZE
-#endif
-
 int keylifetime = 0;
 int keyexpires = 0;
+#ifdef HAVE_LZO
 static char lzo_wrkmem[LZO1X_999_MEM_COMPRESS > LZO1X_1_MEM_COMPRESS ? LZO1X_999_MEM_COMPRESS : LZO1X_1_MEM_COMPRESS];
+#endif
 
 static void send_udppacket(node_t *, vpn_packet_t *);
 
+unsigned replaywin = 16;
+
 #define MAX_SEQNO 1073741824
 
-void send_mtu_probe(node_t *n) {
+// 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
+
+static void send_mtu_probe_handler(void *data) {
+       node_t *n = data;
        vpn_packet_t packet;
        int len, i;
+       int timeout = 1;
        
        n->mtuprobes++;
-       n->mtuevent = NULL;
 
-       if(!n->status.reachable) {
-               logger(LOG_DEBUG, _("Trying to send MTU probe to unreachable node %s (%s)"), n->name, n->hostname);
+       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);
+               n->mtuprobes = 0;
                return;
        }
 
+       if(n->mtuprobes > 32) {
+               ifdebug(TRAFFIC) logger(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->minmtu) {
-               ifdebug(TRAFFIC) logger(LOG_INFO, _("No response to MTU probes from %s (%s)"), n->name, n->hostname);
+               ifdebug(TRAFFIC) logger(LOG_INFO, "No response to MTU probes from %s (%s)", n->name, n->hostname);
+               n->mtuprobes = 0;
                return;
        }
 
+       if(n->mtuprobes == 30 || (n->mtuprobes < 30 && n->minmtu >= n->maxmtu)) {
+               if(n->minmtu > n->maxmtu)
+                       n->minmtu = n->maxmtu;
+               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;
+       }
+
+       if(n->mtuprobes == 31) {
+               timeout = pinginterval;
+               goto end;
+       } else if(n->mtuprobes == 32) {
+               timeout = pingtimeout;
+       }
+
        for(i = 0; i < 3; i++) {
-               if(n->mtuprobes >= 30 || n->minmtu >= n->maxmtu) {
-                       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);
-                       return;
-               }
+               if(n->maxmtu <= n->minmtu)
+                       len = n->maxmtu;
+               else
+                       len = n->minmtu + 1 + rand() % (n->maxmtu - n->minmtu);
 
-               len = n->minmtu + 1 + rand() % (n->maxmtu - n->minmtu);
                if(len < 64)
                        len = 64;
                
                memset(packet.data, 0, 14);
-               RAND_pseudo_bytes(packet.data + 14, len - 14);
+               randomize(packet.data + 14, len - 14);
                packet.len = len;
                packet.priority = 0;
 
-               ifdebug(TRAFFIC) logger(LOG_INFO, _("Sending MTU probe length %d to %s (%s)"), len, n->name, n->hostname);
+               ifdebug(TRAFFIC) logger(LOG_INFO, "Sending MTU probe length %d to %s (%s)", len, n->name, n->hostname);
 
                send_udppacket(n, &packet);
        }
 
-       n->mtuevent = new_event();
-       n->mtuevent->handler = (event_handler_t)send_mtu_probe;
-       n->mtuevent->data = n;
-       n->mtuevent->time = now + 1;
-       event_add(n->mtuevent);
+end:
+       n->mtuevent.time = time(NULL) + timeout;
+       event_add(&n->mtuevent);
+}
+
+void send_mtu_probe(node_t *n) {
+       event_del(&n->mtuevent);
+       n->mtuevent.handler = send_mtu_probe_handler;
+       n->mtuevent.data = n;
+       send_mtu_probe_handler(n);
 }
 
 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);
+       ifdebug(TRAFFIC) logger(LOG_INFO, "Got MTU probe length %d from %s (%s)", packet->len, n->name, n->hostname);
 
        if(!packet->data[0]) {
                packet->data[0] = 1;
-               send_packet(n, packet);
+               send_udppacket(n, packet);
        } else {
+               if(len > n->maxmtu)
+                       len = n->maxmtu;
                if(n->minmtu < len)
                        n->minmtu = len;
+               if(n->mtuprobes > 30)
+                       n->mtuprobes = 30;
        }
 }
 
 static length_t compress_packet(uint8_t *dest, const uint8_t *source, length_t len, int level) {
-       if(level == 10) {
+       if(level == 0) {
+               memcpy(dest, source, len);
+               return len;
+       } else if(level == 10) {
+#ifdef HAVE_LZO
                lzo_uint lzolen = MAXSIZE;
                lzo1x_1_compress(source, len, dest, &lzolen, lzo_wrkmem);
                return lzolen;
+#else
+               return -1;
+#endif
        } else if(level < 10) {
+#ifdef HAVE_ZLIB
                unsigned long destlen = MAXSIZE;
                if(compress2(dest, &destlen, source, len, level) == Z_OK)
                        return destlen;
                else
+#endif
                        return -1;
        } else {
+#ifdef HAVE_LZO
                lzo_uint lzolen = MAXSIZE;
                lzo1x_999_compress(source, len, dest, &lzolen, lzo_wrkmem);
                return lzolen;
+#else
+               return -1;
+#endif
        }
        
        return -1;
 }
 
 static length_t uncompress_packet(uint8_t *dest, const uint8_t *source, length_t len, int level) {
-       if(level > 9) {
+       if(level == 0) {
+               memcpy(dest, source, len);
+               return len;
+       } else if(level > 9) {
+#ifdef HAVE_LZO
                lzo_uint lzolen = MAXSIZE;
                if(lzo1x_decompress_safe(source, len, dest, &lzolen, NULL) == LZO_E_OK)
                        return lzolen;
                else
+#endif
                        return -1;
-       } else {
+       }
+#ifdef HAVE_ZLIB
+       else {
                unsigned long destlen = MAXSIZE;
                if(uncompress(dest, &destlen, source, len) == Z_OK)
                        return destlen;
                else
                        return -1;
        }
-       
+#endif
+
        return -1;
 }
 
 /* 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)"),
+       ifdebug(TRAFFIC) logger(LOG_DEBUG, "Received packet of %d bytes from %s (%s)",
                           packet->len, n->name, n->hostname);
 
        route(n, 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)
+static bool try_mac(node_t *n, const vpn_packet_t *inpkt) {
+       if(!digest_active(&n->indigest) || inpkt->len < sizeof inpkt->seqno + digest_length(&n->indigest))
                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 digest_verify(&n->indigest, &inpkt->seqno, inpkt->len - n->indigest.maclength, (const char *)&inpkt->seqno + inpkt->len - n->indigest.maclength);
 }
 
 static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
@@ -178,86 +243,84 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
        vpn_packet_t *pkt[] = { &pkt1, &pkt2, &pkt1, &pkt2 };
        int nextpkt = 0;
        vpn_packet_t *outpkt = pkt[0];
-       int outlen, outpad;
-       unsigned char hmac[EVP_MAX_MD_SIZE];
+       size_t outlen;
        int i;
 
-       if(!n->inkey) {
-               ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Got packet from %s (%s) but he hasn't got our key yet"),
+       if(!cipher_active(&n->incipher)) {
+               ifdebug(TRAFFIC) logger(LOG_DEBUG, "Got packet from %s (%s) but he hasn't got our key yet",
                                        n->name, n->hostname);
                return;
        }
 
        /* Check packet length */
 
-       if(inpkt->len < sizeof(inpkt->seqno) + n->inmaclength) {
-               ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Got too short packet from %s (%s)"),
+       if(inpkt->len < sizeof inpkt->seqno + digest_length(&n->indigest)) {
+               ifdebug(TRAFFIC) logger(LOG_DEBUG, "Got too short packet from %s (%s)",
                                        n->name, n->hostname);
                return;
        }
 
        /* Check the message authentication code */
 
-       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);
-
-               if(memcmp(hmac, (char *) &inpkt->seqno + inpkt->len, n->inmaclength)) {
-                       ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Got unauthenticated packet from %s (%s)"),
-                                          n->name, n->hostname);
+       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);
                        return;
                }
        }
-
        /* Decrypt the packet */
 
-       if(n->incipher) {
+       if(cipher_active(&n->incipher)) {
                outpkt = pkt[nextpkt++];
+               outlen = MAXSIZE;
 
-               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));
+               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);
                        return;
                }
                
-               outpkt->len = outlen + outpad;
+               outpkt->len = outlen;
                inpkt = outpkt;
        }
 
        /* Check the sequence number */
 
-       inpkt->len -= sizeof(inpkt->seqno);
+       inpkt->len -= sizeof inpkt->seqno;
        inpkt->seqno = ntohl(inpkt->seqno);
 
-       if(inpkt->seqno != n->received_seqno + 1) {
-               if(inpkt->seqno >= n->received_seqno + sizeof(n->late) * 8) {
-                       logger(LOG_WARNING, _("Lost %d packets from %s (%s)"),
-                                          inpkt->seqno - n->received_seqno - 1, n->name, n->hostname);
-                       
-                       memset(n->late, 0, sizeof(n->late));
-               } else if (inpkt->seqno <= n->received_seqno) {
-                       if((n->received_seqno >= sizeof(n->late) * 8 && inpkt->seqno <= n->received_seqno - sizeof(n->late) * 8) || !(n->late[(inpkt->seqno / 8) % sizeof(n->late)] & (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);
-                               return;
+       if(replaywin) {
+               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);
+                                       return;
+                               }
+                               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) {
+                               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);
+                                       return;
+                               }
+                       } else {
+                               for(i = n->received_seqno + 1; i < inpkt->seqno; i++)
+                                       n->late[(i / 8) % replaywin] |= 1 << i % 8;
                        }
-               } else {
-                       for(i = n->received_seqno + 1; i < inpkt->seqno; i++)
-                               n->late[(i / 8) % sizeof(n->late)] |= 1 << i % 8;
                }
+
+               n->farfuture = 0;
+               n->late[(inpkt->seqno / 8) % replaywin] &= ~(1 << inpkt->seqno % 8);
        }
-       
-       n->late[(inpkt->seqno / 8) % sizeof(n->late)] &= ~(1 << inpkt->seqno % 8);
 
        if(inpkt->seqno > n->received_seqno)
                n->received_seqno = inpkt->seqno;
                        
        if(n->received_seqno > MAX_SEQNO)
-               keyexpires = 0;
+               regenerate_key();
 
        /* Decompress the packet */
 
@@ -267,7 +330,7 @@ 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)"),
+                       ifdebug(TRAFFIC) logger(LOG_ERR, "Error while uncompressing packet from %s (%s)",
                                                 n->name, n->hostname);
                        return;
                }
@@ -279,9 +342,6 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
 
        inpkt->priority = 0;
 
-       if(n->connection)
-               n->connection->last_ping_time = now;
-
        if(!inpkt->data[12] && !inpkt->data[13])
                mtu_probe_h(n, inpkt, origlen);
        else
@@ -308,27 +368,31 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
        int nextpkt = 0;
        vpn_packet_t *outpkt;
        int origlen;
-       int outlen, outpad;
+       size_t outlen;
+#if defined(SOL_IP) && defined(IP_TOS)
        static int priority = 0;
+#endif
        int origpriority;
        int sock;
 
        if(!n->status.reachable) {
-               ifdebug(TRAFFIC) logger(LOG_INFO, _("Trying to send UDP packet to unreachable node %s (%s)"), n->name, n->hostname);
+               ifdebug(TRAFFIC) logger(LOG_INFO, "Trying to send UDP packet to unreachable node %s (%s)", n->name, n->hostname);
                return;
        }
 
        /* Make sure we have a valid key */
 
        if(!n->status.validkey) {
+               time_t now = time(NULL);
+
                ifdebug(TRAFFIC) logger(LOG_INFO,
-                                  _("No valid key known yet for %s (%s), forwarding via TCP"),
+                                  "No valid key known yet for %s (%s), forwarding via TCP",
                                   n->name, n->hostname);
 
-               if(!n->status.waitingforkey)
+               if(n->last_req_key + 10 < now) {
                        send_req_key(n);
-
-               n->status.waitingforkey = true;
+                       n->last_req_key = now;
+               }
 
                send_tcppacket(n->nexthop->connection, origpkt);
 
@@ -337,10 +401,13 @@ 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 TCP"),
-                               n->name, n->hostname);
+                               "Packet for %s (%s) larger than minimum MTU, forwarding via %s",
+                               n->name, n->hostname, n != n->nexthop ? n->nexthop->name : "TCP");
 
-               send_tcppacket(n->nexthop->connection, origpkt);
+               if(n != n->nexthop)
+                       send_packet(n->nexthop, origpkt);
+               else
+                       send_tcppacket(n->nexthop->connection, origpkt);
 
                return;
        }
@@ -354,7 +421,7 @@ 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)"),
+                       ifdebug(TRAFFIC) logger(LOG_ERR, "Error while compressing packet to %s (%s)",
                                   n->name, n->hostname);
                        return;
                }
@@ -365,32 +432,28 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
        /* Add sequence number */
 
        inpkt->seqno = htonl(++(n->sent_seqno));
-       inpkt->len += sizeof(inpkt->seqno);
+       inpkt->len += sizeof inpkt->seqno;
 
        /* Encrypt the packet */
 
-       if(n->outcipher) {
+       if(cipher_active(&n->outcipher)) {
                outpkt = pkt[nextpkt++];
+               outlen = MAXSIZE;
 
-               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));
+               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);
                        goto end;
                }
 
-               outpkt->len = outlen + outpad;
+               outpkt->len = outlen;
                inpkt = outpkt;
        }
 
        /* Add the message authentication code */
 
-       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 += n->outmaclength;
+       if(digest_active(&n->outdigest)) {
+               digest_create(&n->outdigest, &inpkt->seqno, inpkt->len, (char *)&inpkt->seqno + inpkt->len);
+               inpkt->len += digest_length(&n->outdigest);
        }
 
        /* Determine which socket we have to use */
@@ -408,20 +471,20 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
        if(priorityinheritance && origpriority != priority
           && listen_socket[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));
+               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));
        }
 #endif
 
-       if((sendto(listen_socket[sock].udp, (char *) &inpkt->seqno, inpkt->len, 0, &(n->address.sa), SALEN(n->address.sa))) < 0) {
-               if(errno == EMSGSIZE) {
+       if(sendto(listen_socket[sock].udp, (char *) &inpkt->seqno, inpkt->len, 0, &(n->address.sa), SALEN(n->address.sa)) < 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, strerror(errno));
+                       logger(LOG_ERR, "Error sending packet to %s (%s): %s", n->name, n->hostname, sockstrerror(sockerrno));
        }
 
 end:
@@ -441,11 +504,11 @@ void send_packet(const node_t *n, vpn_packet_t *packet) {
                return;
        }
 
-       ifdebug(TRAFFIC) logger(LOG_ERR, _("Sending packet of %d bytes to %s (%s)"),
+       ifdebug(TRAFFIC) logger(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"),
+               ifdebug(TRAFFIC) logger(LOG_INFO, "Node %s (%s) is not reachable",
                                   n->name, n->hostname);
                return;
        }
@@ -453,7 +516,7 @@ void send_packet(const node_t *n, vpn_packet_t *packet) {
        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)"),
+               ifdebug(TRAFFIC) logger(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)) {
@@ -466,10 +529,10 @@ void send_packet(const 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) {
-       avl_node_t *node;
+       splay_node_t *node;
        connection_t *c;
 
-       ifdebug(TRAFFIC) logger(LOG_INFO, _("Broadcasting packet of %d bytes from %s (%s)"),
+       ifdebug(TRAFFIC) logger(LOG_INFO, "Broadcasting packet of %d bytes from %s (%s)",
                           packet->len, from->name, from->hostname);
 
        if(from != myself) {
@@ -490,61 +553,78 @@ void broadcast_packet(const node_t *from, vpn_packet_t *packet) {
 }
 
 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;
+       splay_node_t *node;
+       node_t *n, *found = NULL;
+       static time_t last_hard_try = 0;
+       time_t now = time(NULL);
 
-       for(node = edge_weight_tree->head; node; node = node->next) {
-               e = node->data;
-
-               if(sockaddrcmp_noport(from, &e->address))
-                       continue;
+       if(last_hard_try == now)
+               return NULL;
+       else
+               last_hard_try = now;
 
-               if(!n)
-                       n = e->to;
+       for(node = node_tree->head; node; node = node->next) {
+               n = node->data;
 
-               if(!try_mac(e->to, pkt))
+               if(n == myself || !n->status.reachable || !digest_active(&n->indigest))
                        continue;
 
-               n = e->to;
-               break;
+               if(try_mac(n, pkt)) {
+                       found = n;
+                       break;
+               }
        }
 
-       return n;
+       return found;
 }
 
-void handle_incoming_vpn_data(int sock) {
+void handle_incoming_vpn_data(void *arg) {
+       listen_socket_t *l = arg;
        vpn_packet_t pkt;
        char *hostname;
        sockaddr_t from;
-       socklen_t fromlen = sizeof(from);
+       socklen_t fromlen = sizeof from;
        node_t *n;
+       int len;
 
-       pkt.len = recvfrom(sock, (char *) &pkt.seqno, MAXSIZE, 0, &from.sa, &fromlen);
+       while(true) {
+               len = recvfrom(l->udp, (char *) &pkt.seqno, MAXSIZE, 0, &from.sa, &fromlen);
 
-       if(pkt.len < 0) {
-               if(errno != EAGAIN && errno != EINTR)
-                       logger(LOG_ERR, _("Receiving packet failed: %s"), strerror(errno));
-               return;
-       }
+               if(len <= 0 || len > MAXSIZE) {
+                       logger(LOG_ERR, "Receiving packet failed: %s", sockstrerror(sockerrno));
+                       return;
+               }
 
-       sockaddrunmap(&from);           /* Some braindead IPv6 implementations do stupid things. */
+               pkt.len = len;
 
-       n = lookup_node_udp(&from);
+               sockaddrunmap(&from);           /* Some braindead IPv6 implementations do stupid things. */
 
-       if(!n) {
-               n = try_harder(&from, &pkt);
-               if(n)
-                       update_node_udp(n, &from);
-               else ifdebug(PROTOCOL) {
-                       hostname = sockaddr2hostname(&from);
-                       logger(LOG_WARNING, _("Received UDP packet from unknown source %s"), hostname);
-                       free(hostname);
-                       return;
+               mutex_lock(&mutex);
+               n = lookup_node_udp(&from);
+
+               if(!n) {
+                       n = try_harder(&from, &pkt);
+                       if(n)
+                               update_node_udp(n, &from);
                }
-               else
-                       return;
+
+               if(n) {
+                       receive_udppacket(n, &pkt);
+               } else {
+                       ifdebug(PROTOCOL) {
+                               hostname = sockaddr2hostname(&from);
+                               logger(LOG_WARNING, "Received UDP packet from unknown source %s", hostname);
+                               free(hostname);
+                       }
+               }
+
+               mutex_unlock(&mutex);
        }
+}
+
+void handle_device_data(int sock, short events, void *data) {
+       vpn_packet_t packet;
 
-       receive_udppacket(n, &pkt);
+       if(read_packet(&packet))
+               route(myself, &packet);
 }