From 56aad1bb486675ff9aba31418708cc179eea0381 Mon Sep 17 00:00:00 2001 From: Guus Sliepen Date: Sat, 20 Mar 2004 15:28:55 +0000 Subject: [PATCH] Applied Martin Kihlgren's IdentityGenerosity patch, simplified and renamed to StrictSource. --- src/graph.c | 21 ++-------------- src/net.h | 1 + src/net_packet.c | 63 ++++++++++++++++++++++++++++++++---------------- src/net_setup.c | 2 ++ src/node.c | 22 +++++++++++++++++ src/node.h | 1 + 6 files changed, 70 insertions(+), 40 deletions(-) diff --git a/src/graph.c b/src/graph.c index 3ed1d721..3870c709 100644 --- a/src/graph.c +++ b/src/graph.c @@ -219,25 +219,8 @@ void sssp_bfs(void) e->to->via = indirect ? n->via : e->to; e->to->options = e->options; - if(sockaddrcmp(&e->to->address, &e->address)) { - node = avl_unlink(node_udp_tree, e->to); - sockaddrfree(&e->to->address); - sockaddrcpy(&e->to->address, &e->address); - - if(e->to->hostname) - free(e->to->hostname); - - e->to->hostname = sockaddr2hostname(&e->to->address); - avl_insert_node(node_udp_tree, node); - - if(e->to->options & OPTION_PMTU_DISCOVERY) { - e->to->mtuprobes = 0; - e->to->minmtu = 0; - e->to->maxmtu = MTU; - if(e->to->status.validkey) - send_mtu_probe(e->to); - } - } + if(sockaddrcmp(&e->to->address, &e->address)) + update_node_address(e->to, &e->address); node = avl_alloc_node(); node->data = e->to; diff --git a/src/net.h b/src/net.h index 5b145538..90463eb2 100644 --- a/src/net.h +++ b/src/net.h @@ -122,6 +122,7 @@ extern listen_socket_t listen_socket[MAXSOCKETS]; extern int listen_sockets; extern int keyexpires; extern int keylifetime; +extern bool strictsource; extern bool do_prune; extern bool do_purge; extern char *myport; diff --git a/src/net_packet.c b/src/net_packet.c index 255453e9..ae5a8402 100644 --- a/src/net_packet.c +++ b/src/net_packet.c @@ -54,6 +54,7 @@ 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]; @@ -167,6 +168,25 @@ 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; @@ -174,32 +194,17 @@ 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(); - /* 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); + if(!authenticate_udppacket(n, inpkt)) { + ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Got unauthenticated packet from %s (%s)"), + n->name, n->hostname); return; } - /* 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; - } - } + inpkt->len -= myself->digest ? myself->maclength : 0; /* Decrypt the packet */ @@ -483,6 +488,7 @@ void handle_incoming_vpn_data(int sock) sockaddr_t from; socklen_t fromlen = sizeof(from); node_t *n; + static time_t lasttime = 0; cp(); @@ -497,10 +503,25 @@ 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; } diff --git a/src/net_setup.c b/src/net_setup.c index aa2fbfbe..502e7b20 100644 --- a/src/net_setup.c +++ b/src/net_setup.c @@ -343,6 +343,8 @@ bool setup_myself(void) get_config_bool(lookup_config(config_tree, "Hostnames"), &hostnames); + get_config_bool(lookup_config(config_tree, "StrictSource"), &strictsource); + /* Generate packet encryption key */ if(get_config_string diff --git a/src/node.c b/src/node.c index 35199161..79320e71 100644 --- a/src/node.c +++ b/src/node.c @@ -150,6 +150,28 @@ void node_del(node_t *n) avl_delete(node_udp_tree, n); } +void update_node_address(node_t *n, const sockaddr_t address) { + avl_node_t *node; + + node = avl_unlink(node_udp_tree, n); + sockaddrfree(&n->address); + sockaddrcpy(&n->address, &address); + + if(n->hostname) + free(n->hostname); + + n->hostname = sockaddr2hostname(&n->address); + avl_insert_node(node_udp_tree, node); + + if(n->options & OPTION_PMTU_DISCOVERY) { + n->mtuprobes = 0; + n->minmtu = 0; + n->maxmtu = MTU; + if(n->status.validkey) + send_mtu_probe(n); + } +} + node_t *lookup_node(char *name) { node_t n = {0}; diff --git a/src/node.h b/src/node.h index dd9c7a12..6dc7338b 100644 --- a/src/node.h +++ b/src/node.h @@ -90,6 +90,7 @@ extern node_t *new_node(void) __attribute__ ((__malloc__)); extern void free_node(node_t *); extern void node_add(node_t *); extern void node_del(node_t *); +extern void update_node_udpaddress(node_t *, const sockaddr_t *); extern node_t *lookup_node(char *); extern node_t *lookup_node_udp(const sockaddr_t *); extern void dump_nodes(void); -- 2.39.5