/*
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
// mtuprobes == 1..30: initial discovery, send bursts with 1 second interval
// mtuprobes == 32: send 1 burst, sleep pingtimeout second
// mtuprobes == 33: no response from other side, restart PMTU discovery process
-void send_mtu_probe(node_t *n) {
+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 || !n->status.validkey) {
- logger(LOG_DEBUG, "Trying to send MTU probe to unreachable node %s (%s)", n->name, n->hostname);
+ 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 == 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;
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;
}
end:
- n->mtuevent = new_event();
- n->mtuevent->handler = (event_handler_t)send_mtu_probe;
- n->mtuevent->data = n;
- n->mtuevent->time = now + timeout;
- event_add(n->mtuevent);
+ 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) {
if(!packet->data[0]) {
packet->data[0] = 1;
- send_packet(n, packet);
+ send_udppacket(n, packet);
} else {
if(len > n->maxmtu)
len = n->maxmtu;
}
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;
}
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) {
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) {
+ 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) {
+ 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 */
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;
/* 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",
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);
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;
}
/* 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 */
&& 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 */
+ 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:
/* 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)",
}
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);
}