X-Git-Url: https://www.tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fnet_packet.c;h=ed49b0b2add2020cc0e62ec414e009ee72b04e70;hp=ae5a8402a7af159ad3873b877854c2b286a0c485;hb=0077cfaae112b63d6af6aa1e5d079cebdde84b74;hpb=56aad1bb486675ff9aba31418708cc179eea0381 diff --git a/src/net_packet.c b/src/net_packet.c index ae5a8402..ed49b0b2 100644 --- 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 , - 2000-2003 Guus Sliepen + Copyright (C) 1998-2004 Ivo Timmermans , + 2000-2004 Guus Sliepen 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 1.1.2.49 2003/12/27 16:32:52 guus Exp $ + $Id$ */ #include "system.h" @@ -54,7 +54,6 @@ int keylifetime = 0; int keyexpires = 0; -bool strictsource = true; EVP_CIPHER_CTX packet_ctx; static char lzo_wrkmem[LZO1X_999_MEM_COMPRESS > LZO1X_1_MEM_COMPRESS ? LZO1X_999_MEM_COMPRESS : LZO1X_1_MEM_COMPRESS]; @@ -168,25 +167,6 @@ static void receive_packet(node_t *n, vpn_packet_t *packet) route(n, packet); } -static bool authenticate_udppacket(node_t *n, vpn_packet_t *inpkt) { - char hmac[EVP_MAX_MD_SIZE]; - - if(inpkt->len < sizeof(inpkt->seqno) + (myself->digest ? myself->maclength : 0)) - return false; - - /* Check the message authentication code */ - - if(myself->digest && myself->maclength) { - HMAC(myself->digest, myself->key, myself->keylength, - (char *) &inpkt->seqno, inpkt->len - myself->maclength, hmac, NULL); - - if(memcmp(hmac, (char *) &inpkt->seqno + inpkt->len - myself->maclength, myself->maclength)) - return false; - } - - return true; -} - static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) { vpn_packet_t pkt1, pkt2; @@ -194,17 +174,32 @@ 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]; int i; cp(); - if(!authenticate_udppacket(n, inpkt)) { - ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Got unauthenticated packet from %s (%s)"), - n->name, n->hostname); + /* Check packet length */ + + if(inpkt->len < sizeof(inpkt->seqno) + myself->maclength) { + ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Got too short packet from %s (%s)"), + n->name, n->hostname); return; } - inpkt->len -= myself->digest ? myself->maclength : 0; + /* Check the message authentication code */ + + if(myself->digest && myself->maclength) { + inpkt->len -= myself->maclength; + HMAC(myself->digest, myself->key, myself->keylength, + (char *) &inpkt->seqno, inpkt->len, hmac, NULL); + + if(memcmp(hmac, (char *) &inpkt->seqno + inpkt->len, myself->maclength)) { + ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Got unauthenticated packet from %s (%s)"), + n->name, n->hostname); + return; + } + } /* Decrypt the packet */ @@ -236,17 +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; @@ -458,6 +457,12 @@ 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) { + if(overwrite_mac) + memcpy(packet->data, mymac.x, ETH_ALEN); + write_packet(packet); + } + for(node = connection_tree->head; node; node = node->next) { c = node->data; @@ -488,7 +493,6 @@ void handle_incoming_vpn_data(int sock) sockaddr_t from; socklen_t fromlen = sizeof(from); node_t *n; - static time_t lasttime = 0; cp(); @@ -503,25 +507,10 @@ void handle_incoming_vpn_data(int sock) n = lookup_node_udp(&from); - if(!n && !strictsource && myself->digest && myself->maclength && lasttime != now) { - avl_node_t *node; - - lasttime = now; - - for(node = node_tree->head; node; node = node->next) { - n = node->data; - - if(authenticate_udppacket(n, &pkt)) { - update_node_address(n, &from); - logger(LOG_DEBUG, _("Updated address of node %s to %s"), n->name, n->hostname); - break; - } - } - } - if(!n) { hostname = sockaddr2hostname(&from); - logger(LOG_WARNING, _("Received UDP packet from unknown source %s"), hostname); + logger(LOG_WARNING, _("Received UDP packet from unknown source %s"), + hostname); free(hostname); return; }