Always send MTU probes at least once every PingInterval.
[tinc] / src / net_packet.c
index 3243670..aef5534 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 "conf.h"
 #include "utils.h"
 #include "xalloc.h"
 
-#ifdef HAVE_MINGW
-#include <winerror.h>
-#define EMSGSIZE WSAEMSGSIZE
-#define EAGAIN WSATRY_AGAIN
-#define EINTR WSAEINTR
-#define sockstrerror(x) winerror(x)
-#define sockerrno WSAGetLastError()
-#else
-#define sockstrerror(x) strerror(x)
-#define sockerrno errno
-#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
 
 // mtuprobes == 1..30: initial discovery, send bursts with 1 second interval
@@ -86,16 +85,21 @@ void send_mtu_probe(node_t *n) {
        }
 
        if(n->mtuprobes > 32) {
+               if(!n->minmtu) {
+                       n->mtuprobes = 31;
+                       timeout = pinginterval;
+                       goto end;
+               }
+
                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) {
+       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);
-               n->mtuprobes = 0;
-               return;
+               n->mtuprobes = 31;
        }
 
        if(n->mtuprobes == 30 || (n->mtuprobes < 30 && n->minmtu >= n->maxmtu)) {
@@ -149,50 +153,76 @@ void mtu_probe_h(node_t *n, vpn_packet_t *packet, length_t len) {
                packet->data[0] = 1;
                send_udppacket(n, packet);
        } else {
+               if(n->mtuprobes > 30) {
+                       if(n->minmtu)
+                               n->mtuprobes = 30;
+                       else
+                               n->mtuprobes = 1;
+               }
+
                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;
 }
 
@@ -276,25 +306,32 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
        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;
@@ -349,7 +386,9 @@ 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;
        int sock;
 
@@ -365,10 +404,10 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
                                   "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);
 
@@ -457,8 +496,8 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
        }
 #endif
 
-       if((sendto(listen_socket[sock].udp, (char *) &inpkt->seqno, inpkt->len, 0, &(n->address.sa), SALEN(n->address.sa))) < 0) {
-               if(sockerrno == 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)
@@ -570,7 +609,7 @@ void handle_incoming_vpn_data(int sock) {
        pkt.len = recvfrom(sock, (char *) &pkt.seqno, MAXSIZE, 0, &from.sa, &fromlen);
 
        if(pkt.len < 0) {
-               if(sockerrno != EAGAIN && sockerrno != EINTR)
+               if(!sockwouldblock(sockerrno))
                        logger(LOG_ERR, "Receiving packet failed: %s", sockstrerror(sockerrno));
                return;
        }