Restore length of the original packet in send_udppacket().

[tinc] / src / net_packet.c

diff --git a/src/net_packet.c b/src/net_packet.c
index ac4ad42..8b877c2 100644 (file)
--- a/src/net_packet.c
+++ b/src/net_packet.c
@@ -1,7 +1,7 @@
 /*
     net_packet.c -- Handles in- and outgoing VPN packets
-    Copyright (C) 1998-2003 Ivo Timmermans <ivo@o2w.nl>,
-                  2000-2003 Guus Sliepen <guus@sliepen.eu.org>
+    Copyright (C) 1998-2005 Ivo Timmermans,
+                  2000-2006 Guus Sliepen <guus@tinc-vpn.org>
 
     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
@@ -17,7 +17,7 @@
     along with this program; if not, write to the Free Software
     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 
-    $Id: net_packet.c,v 1.1.2.45 2003/12/20 19:47:52 guus Exp $
+    $Id$
 */
 
 #include "system.h"
@@ -35,6 +35,7 @@
 #include "conf.h"
 #include "connection.h"
 #include "device.h"
+#include "ethernet.h"
 #include "event.h"
 #include "graph.h"
 #include "list.h"
@@ -47,6 +48,10 @@
 #include "utils.h"
 #include "xalloc.h"
 
+#ifdef WSAEMSGSIZE
+#define EMSGSIZE WSAEMSGSIZE
+#endif
+
 int keylifetime = 0;
 int keyexpires = 0;
 EVP_CIPHER_CTX packet_ctx;
@@ -64,15 +69,21 @@ void send_mtu_probe(node_t *n)
        cp();
 
        n->mtuprobes++;
+       n->mtuevent = NULL;
+
+       if(n->mtuprobes >= 10 && !n->minmtu) {
+               ifdebug(TRAFFIC) logger(LOG_INFO, _("No response to MTU probes from %s (%s)"), n->name, n->hostname);
+               return;
+       }
 
        for(i = 0; i < 3; i++) {
-               if(n->mtuprobes >= 100 || n->probedmtu >= n->mtu) {
-                       n->mtu = n->probedmtu;
+               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;
                }
 
-               len = n->probedmtu + 1 + random() % (n->mtu - n->probedmtu);
+               len = n->minmtu + 1 + random() % (n->maxmtu - n->minmtu);
                if(len < 64)
                        len = 64;
                
@@ -99,8 +110,8 @@ void mtu_probe_h(node_t *n, vpn_packet_t *packet) {
                packet->data[0] = 1;
                send_packet(n, packet);
        } else {
-               if(n->probedmtu < packet->len)
-                       n->probedmtu = packet->len;
+               if(n->minmtu < packet->len)
+                       n->minmtu = packet->len;
        }
 }
 
@@ -163,7 +174,7 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt)
        int nextpkt = 0;
        vpn_packet_t *outpkt = pkt[0];
        int outlen, outpad;
-       char hmac[EVP_MAX_MD_SIZE];
+       unsigned char hmac[EVP_MAX_MD_SIZE];
        int i;
 
        cp();
@@ -181,7 +192,7 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt)
        if(myself->digest && myself->maclength) {
                inpkt->len -= myself->maclength;
                HMAC(myself->digest, myself->key, myself->keylength,
-                        (char *) &inpkt->seqno, inpkt->len, hmac, NULL);
+                        (unsigned char *) &inpkt->seqno, inpkt->len, (unsigned char *)hmac, NULL);
 
                if(memcmp(hmac, (char *) &inpkt->seqno + inpkt->len, myself->maclength)) {
                        ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Got unauthenticated packet from %s (%s)"),
@@ -196,9 +207,9 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt)
                outpkt = pkt[nextpkt++];
 
                if(!EVP_DecryptInit_ex(&packet_ctx, NULL, NULL, NULL, NULL)
-                               || !EVP_DecryptUpdate(&packet_ctx, (char *) &outpkt->seqno, &outlen,
-                                       (char *) &inpkt->seqno, inpkt->len)
-                               || !EVP_DecryptFinal_ex(&packet_ctx, (char *) &outpkt->seqno + outlen, &outpad)) {
+                               || !EVP_DecryptUpdate(&packet_ctx, (unsigned char *) &outpkt->seqno, &outlen,
+                                       (unsigned char *) &inpkt->seqno, inpkt->len)
+                               || !EVP_DecryptFinal_ex(&packet_ctx, (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));
                        return;
@@ -220,17 +231,21 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt)
                        
                        memset(n->late, 0, sizeof(n->late));
                } else if (inpkt->seqno <= n->received_seqno) {
-                       if(inpkt->seqno <= n->received_seqno - sizeof(n->late) * 8 || !(n->late[(inpkt->seqno / 8) % sizeof(n->late)] & (1 << inpkt->seqno % 8))) {
+                       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);
-                       } else
-                               for(i = n->received_seqno + 1; i < inpkt->seqno; i++)
-                                       n->late[(inpkt->seqno / 8) % sizeof(n->late)] |= 1 << i % 8;
+                               return;
+                       }
+               } else {
+                       for(i = n->received_seqno + 1; i < inpkt->seqno; i++)
+                               n->late[(i / 8) % sizeof(n->late)] |= 1 << i % 8;
                }
        }
        
-       n->received_seqno = inpkt->seqno;
-       n->late[(n->received_seqno / 8) % sizeof(n->late)] &= ~(1 << n->received_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;
@@ -270,10 +285,11 @@ void receive_tcppacket(connection_t *c, char *buffer, int len)
        receive_packet(c->node, &outpkt);
 }
 
-static void send_udppacket(node_t *n, vpn_packet_t *inpkt)
+static void send_udppacket(node_t *n, vpn_packet_t *origpkt)
 {
        vpn_packet_t pkt1, pkt2;
        vpn_packet_t *pkt[] = { &pkt1, &pkt2, &pkt1, &pkt2 };
+       vpn_packet_t *inpkt = origpkt;
        int nextpkt = 0;
        vpn_packet_t *outpkt;
        int origlen;
@@ -337,12 +353,12 @@ static void send_udppacket(node_t *n, vpn_packet_t *inpkt)
                outpkt = pkt[nextpkt++];
 
                if(!EVP_EncryptInit_ex(&n->packet_ctx, NULL, NULL, NULL, NULL)
-                               || !EVP_EncryptUpdate(&n->packet_ctx, (char *) &outpkt->seqno, &outlen,
-                                       (char *) &inpkt->seqno, inpkt->len)
-                               || !EVP_EncryptFinal_ex(&n->packet_ctx, (char *) &outpkt->seqno + outlen, &outpad)) {
+                               || !EVP_EncryptUpdate(&n->packet_ctx, (unsigned char *) &outpkt->seqno, &outlen,
+                                       (unsigned char *) &inpkt->seqno, inpkt->len)
+                               || !EVP_EncryptFinal_ex(&n->packet_ctx, (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));
-                       return;
+                       goto end;
                }
 
                outpkt->len = outlen + outpad;
@@ -352,8 +368,8 @@ static void send_udppacket(node_t *n, vpn_packet_t *inpkt)
        /* Add the message authentication code */
 
        if(n->digest && n->maclength) {
-               HMAC(n->digest, n->key, n->keylength, (char *) &inpkt->seqno,
-                        inpkt->len, (char *) &inpkt->seqno + inpkt->len, &outlen);
+               HMAC(n->digest, n->key, n->keylength, (unsigned char *) &inpkt->seqno,
+                        inpkt->len, (unsigned char *) &inpkt->seqno + inpkt->len, NULL);
                inpkt->len += n->maclength;
        }
 
@@ -379,15 +395,17 @@ static void send_udppacket(node_t *n, vpn_packet_t *inpkt)
 #endif
 
        if((sendto(listen_socket[sock].udp, (char *) &inpkt->seqno, inpkt->len, 0, &(n->address.sa), SALEN(n->address.sa))) < 0) {
-               logger(LOG_ERR, _("Error sending packet to %s (%s): %s"), n->name, n->hostname, strerror(errno));
                if(errno == EMSGSIZE) {
+                       if(n->maxmtu >= origlen)
+                               n->maxmtu = origlen - 1;
                        if(n->mtu >= origlen)
                                n->mtu = origlen - 1;
-               }
-               return;
+               } else
+                       logger(LOG_ERR, _("Error sending packet to %s (%s): %s"), n->name, n->hostname, strerror(errno));
        }
 
-       inpkt->len = origlen;
+end:
+       origpkt->len = origlen;
 }
 
 /*
@@ -400,6 +418,8 @@ void send_packet(const node_t *n, vpn_packet_t *packet)
        cp();
 
        if(n == myself) {
+               if(overwrite_mac)
+                        memcpy(packet->data, mymac.x, ETH_ALEN);
                write_packet(packet);
                return;
        }
@@ -438,6 +458,9 @@ void broadcast_packet(const node_t *from, vpn_packet_t *packet)
        ifdebug(TRAFFIC) logger(LOG_INFO, _("Broadcasting packet of %d bytes from %s (%s)"),
                           packet->len, from->name, from->hostname);
 
+       if(from != myself)
+               send_packet(myself, packet);
+
        for(node = connection_tree->head; node; node = node->next) {
                c = node->data;