/*
net_packet.c -- Handles in- and outgoing VPN packets
Copyright (C) 1998-2005 Ivo Timmermans,
- 2000-2010 Guus Sliepen <guus@tinc-vpn.org>
+ 2000-2012 Guus Sliepen <guus@tinc-vpn.org>
2010 Timothy Redaelli <timothy@redaelli.eu>
2010 Brandon Black <blblack@gmail.com>
#include "ethernet.h"
#include "event.h"
#include "graph.h"
-#include "list.h"
#include "logger.h"
#include "net.h"
#include "netutl.h"
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;
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);
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;
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->last_req_key + 10 < now) {
+ if(n->last_req_key + 10 <= now) {
send_req_key(n);
n->last_req_key = now;
}
/* 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 && !sockwouldblock(sockerrno)) {
+ 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, sockstrerror(sockerrno));
+ ifdebug(TRAFFIC) logger(LOG_WARNING, "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;
}
void broadcast_packet(const node_t *from, vpn_packet_t *packet) {
avl_node_t *node;
connection_t *c;
+ node_t *n;
+
+ // Always give ourself a copy of the packet.
+ if(from != myself)
+ send_packet(myself, packet);
+
+ // In TunnelServer mode, do not forward broadcast packets.
+ // The MST might not be valid and create loops.
+ if(tunnelserver || broadcast_mode == BMODE_NONE)
+ return;
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);
+ switch(broadcast_mode) {
+ // In MST mode, broadcast packets travel via the Minimum Spanning Tree.
+ // This guarantees all nodes receive the broadcast packet, and
+ // usually distributes the sending of broadcast packets over all nodes.
+ case BMODE_MST:
+ for(node = connection_tree->head; node; node = node->next) {
+ c = node->data;
- // In TunnelServer mode, do not forward broadcast packets.
- // The MST might not be valid and create loops.
- if(tunnelserver)
- return;
- }
+ if(c->status.active && c->status.mst && c != from->nexthop->connection)
+ send_packet(c->node, packet);
+ }
+ break;
+
+ // In direct mode, we send copies to each node we know of.
+ // However, this only reaches nodes that can be reached in a single hop.
+ // We don't have enough information to forward broadcast packets in this case.
+ case BMODE_DIRECT:
+ if(from != myself)
+ break;
- for(node = connection_tree->head; node; node = node->next) {
- c = node->data;
+ for(node = node_udp_tree->head; node; node = node->next) {
+ n = node->data;
- if(c->status.active && c->status.mst && c != from->nexthop->connection)
- send_packet(c->node, packet);
+ if(n->status.reachable && ((n->via == myself && n->nexthop == n) || n->via == n))
+ send_packet(n, packet);
+ }
+ break;
+
+ default:
+ break;
}
}
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(!sockwouldblock(sockerrno))
return;
}
+ n->sock = sock;
+
receive_udppacket(n, &pkt);
}
projects / tinc / blobdiff