/*
net_packet.c -- Handles in- and outgoing VPN packets
Copyright (C) 1998-2005 Ivo Timmermans,
- 2000-2009 Guus Sliepen <guus@tinc-vpn.org>
+ 2000-2011 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 "ethernet.h"
#include "event.h"
#include "graph.h"
-#include "list.h"
#include "logger.h"
#include "net.h"
#include "netutl.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;
+bool localdiscovery = false;
+
#define MAX_SEQNO 1073741824
-// mtuprobes == 1..30: initial discovery, send bursts with 1 second interval
-// mtuprobes == 31: sleep pinginterval seconds
-// mtuprobes == 32: send 1 burst, sleep pingtimeout second
-// mtuprobes == 33: no response from other side, restart PMTU discovery process
+/* mtuprobes == 1..30: initial discovery, send bursts with 1 second interval
+ mtuprobes == 31: sleep pinginterval seconds
+ mtuprobes == 32: send 1 burst, sleep pingtimeout second
+ mtuprobes == 33: no response from other side, restart PMTU discovery process
+
+ Probes are sent in batches of three, with random sizes between the lower and
+ upper boundaries for the MTU thus far discovered.
+
+ In case local discovery is enabled, a fourth packet is added to each batch,
+ which will be broadcast to the local network.
+*/
void send_mtu_probe(node_t *n) {
vpn_packet_t packet;
}
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)) {
+ 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;
timeout = pingtimeout;
}
- for(i = 0; i < 3; i++) {
+ for(i = 0; i < 3 + localdiscovery; i++) {
if(n->maxmtu <= n->minmtu)
len = n->maxmtu;
else
memset(packet.data, 0, 14);
RAND_pseudo_bytes(packet.data + 14, len - 14);
packet.len = len;
- packet.priority = 0;
+ if(i >= 3 && n->mtuprobes <= 10)
+ packet.priority = -1;
+ else
+ packet.priority = 0;
ifdebug(TRAFFIC) logger(LOG_INFO, "Sending MTU probe length %d to %s (%s)", len, n->name, n->hostname);
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;
}
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;
receive_packet(n, inpkt);
}
-void receive_tcppacket(connection_t *c, char *buffer, int len) {
+void receive_tcppacket(connection_t *c, const char *buffer, int len) {
vpn_packet_t outpkt;
outpkt.len = len;
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;
if(!n->status.reachable) {
ifdebug(TRAFFIC) logger(LOG_INFO, "Trying to send UDP packet to unreachable node %s (%s)", n->name, n->hostname);
"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;
}
/* Determine which socket we have to use */
- for(sock = 0; sock < listen_sockets; sock++)
- if(n->address.sa.sa_family == listen_socket[sock].sa.sa.sa_family)
- break;
-
- if(sock >= listen_sockets)
- sock = 0; /* If none is available, just use the first and hope for the best. */
+ if(n->address.sa.sa_family != listen_socket[n->sock].sa.sa.sa_family) {
+ for(int sock = 0; sock < listen_sockets; sock++) {
+ if(n->address.sa.sa_family == listen_socket[sock].sa.sa.sa_family) {
+ n->sock = sock;
+ break;
+ }
+ }
+ }
/* Send the packet */
+ struct sockaddr *sa;
+ socklen_t sl;
+ int sock;
+
+ /* Overloaded use of priority field: -1 means local broadcast */
+
+ if(origpriority == -1 && n->prevedge) {
+ struct sockaddr_in in;
+ in.sin_family = AF_INET;
+ in.sin_addr.s_addr = -1;
+ in.sin_port = n->prevedge->address.in.sin_port;
+ sa = (struct sockaddr *)∈
+ sl = sizeof in;
+ sock = 0;
+ } else {
+ if(origpriority == -1)
+ origpriority = 0;
+
+ sa = &(n->address.sa);
+ sl = SALEN(n->address.sa);
+ sock = n->sock;
+ }
+
#if defined(SOL_IP) && defined(IP_TOS)
if(priorityinheritance && origpriority != priority
- && listen_socket[sock].sa.sa.sa_family == AF_INET) {
+ && listen_socket[n->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[n->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, sa, sl) < 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:
if(n == myself) {
if(overwrite_mac)
memcpy(packet->data, mymac.x, ETH_ALEN);
- write_packet(packet);
+ devops.write(packet);
return;
}
avl_node_t *node;
edge_t *e;
node_t *n = NULL;
+ bool hard = false;
static time_t last_hard_try = 0;
for(node = edge_weight_tree->head; node; node = node->next) {
e = node->data;
+ if(e->to == myself)
+ continue;
+
if(sockaddrcmp_noport(from, &e->address)) {
if(last_hard_try == now)
continue;
- last_hard_try = now;
+ hard = true;
}
- if(!n)
- n = e->to;
-
if(!try_mac(e->to, pkt))
continue;
break;
}
+ if(hard)
+ last_hard_try = now;
+
+ last_hard_try = now;
return n;
}
socklen_t fromlen = sizeof(from);
node_t *n;
- pkt.len = recvfrom(sock, (char *) &pkt.seqno, MAXSIZE, 0, &from.sa, &fromlen);
+ pkt.len = recvfrom(listen_socket[sock].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));
+ if(!sockwouldblock(sockerrno))
+ logger(LOG_ERR, "Receiving packet failed: %s", sockstrerror(sockerrno));
return;
}
return;
}
+ n->sock = sock;
+
receive_udppacket(n, &pkt);
}
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