/*
net_packet.c -- Handles in- and outgoing VPN packets
- Copyright (C) 1998-2005 Ivo Timmermans,
- 2000-2012 Guus Sliepen <guus@tinc-vpn.org>
- 2010 Timothy Redaelli <timothy@redaelli.eu>
- 2010 Brandon Black <blblack@gmail.com>
+ Copyright (C) 2014-2017 Guus Sliepen <guus@meshlink.io>
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 "system.h"
-#include <openssl/rand.h>
-#include <openssl/err.h>
-#include <openssl/evp.h>
-#include <openssl/pem.h>
-#include <openssl/hmac.h>
-
-#ifdef HAVE_ZLIB
-#include <zlib.h>
-#endif
-
-#ifdef HAVE_LZO
-#include LZO1X_H
-#endif
-
-#include "cipher.h"
#include "conf.h"
#include "connection.h"
#include "crypto.h"
-#include "digest.h"
-#include "device.h"
-#include "ethernet.h"
#include "graph.h"
#include "logger.h"
+#include "meshlink_internal.h"
#include "net.h"
#include "netutl.h"
#include "protocol.h"
-#include "process.h"
#include "route.h"
#include "utils.h"
#include "xalloc.h"
int keylifetime = 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;
+static void send_udppacket(meshlink_handle_t *mesh, node_t *, vpn_packet_t *);
#define MAX_SEQNO 1073741824
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.
+ Probes are sent in batches of at least 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,
+ After the initial discovery, a fourth packet is added to each batch with a
+ size larger than the currently known PMTU, to test if the PMTU has increased.
+
+ In case local discovery is enabled, another packet is added to each batch,
which will be broadcast to the local network.
+
*/
-static void send_mtu_probe_handler(int fd, short events, void *data) {
+static void send_mtu_probe_handler(event_loop_t *loop, void *data) {
+ meshlink_handle_t *mesh = loop->data;
node_t *n = data;
int timeout = 1;
n->mtuprobes++;
if(!n->status.reachable || !n->status.validkey) {
- logger(DEBUG_TRAFFIC, LOG_INFO, "Trying to send MTU probe to unreachable or rekeying node %s (%s)", n->name, n->hostname);
+ logger(mesh, MESHLINK_INFO, "Trying to send MTU probe to unreachable or rekeying node %s", n->name);
n->mtuprobes = 0;
return;
}
if(n->mtuprobes > 32) {
if(!n->minmtu) {
n->mtuprobes = 31;
- timeout = pinginterval;
+ timeout = mesh->dev_class_traits[n->devclass].pinginterval;
goto end;
}
- logger(DEBUG_TRAFFIC, LOG_INFO, "%s (%s) did not respond to UDP ping, restarting PMTU discovery", n->name, n->hostname);
+ logger(mesh, MESHLINK_INFO, "%s did not respond to UDP ping, restarting PMTU discovery", n->name);
n->status.udp_confirmed = false;
n->mtuprobes = 1;
n->minmtu = 0;
n->maxmtu = MTU;
+
+ update_node_pmtu(mesh, n);
}
if(n->mtuprobes >= 10 && n->mtuprobes < 32 && !n->minmtu) {
- logger(DEBUG_TRAFFIC, LOG_INFO, "No response to MTU probes from %s (%s)", n->name, n->hostname);
+ logger(mesh, MESHLINK_INFO, "No response to MTU probes from %s", n->name);
n->mtuprobes = 31;
}
if(n->mtuprobes == 30 || (n->mtuprobes < 30 && n->minmtu >= n->maxmtu)) {
- if(n->minmtu > n->maxmtu)
+ if(n->minmtu > n->maxmtu) {
n->minmtu = n->maxmtu;
- else
+ update_node_pmtu(mesh, n);
+ } else {
n->maxmtu = n->minmtu;
+ }
+
n->mtu = n->minmtu;
- logger(DEBUG_TRAFFIC, LOG_INFO, "Fixing MTU of %s (%s) to %d after %d probes", n->name, n->hostname, n->mtu, n->mtuprobes);
+ logger(mesh, MESHLINK_INFO, "Fixing MTU of %s to %d after %d probes", n->name, n->mtu, n->mtuprobes);
n->mtuprobes = 31;
}
if(n->mtuprobes == 31) {
- timeout = pinginterval;
+ if(!n->minmtu && n->status.want_udp) {
+ /* Send a dummy ANS_KEY to try to update the reflexive UDP address */
+ send_request(mesh, n->nexthop->connection, NULL, "%d %s %s . -1 -1 -1 0", ANS_KEY, mesh->self->name, n->name);
+ n->status.want_udp = false;
+ }
+
+ timeout = mesh->dev_class_traits[n->devclass].pinginterval;
goto end;
} else if(n->mtuprobes == 32) {
- timeout = pingtimeout;
+ timeout = mesh->dev_class_traits[n->devclass].pingtimeout;
}
- for(int i = 0; i < 3 + localdiscovery; i++) {
+ for(int i = 0; i < 5; i++) {
int len;
- if(n->maxmtu <= n->minmtu)
+ if(i == 0) {
+ if(n->mtuprobes < 30 || n->maxmtu + 8 >= MTU) {
+ continue;
+ }
+
+ len = n->maxmtu + 8;
+ } else if(n->maxmtu <= n->minmtu) {
len = n->maxmtu;
- else
- len = n->minmtu + 1 + rand() % (n->maxmtu - n->minmtu);
+ } else {
+ len = n->minmtu + 1 + prng(mesh, n->maxmtu - n->minmtu);
+ }
- if(len < 64)
+ if(len < 64) {
len = 64;
+ }
vpn_packet_t packet;
+ packet.probe = true;
memset(packet.data, 0, 14);
randomize(packet.data + 14, len - 14);
packet.len = len;
- if(i >= 3 && n->mtuprobes <= 10)
- packet.priority = -1;
- else
- packet.priority = 0;
+ n->status.broadcast = i >= 4 && n->mtuprobes <= 10 && n->prevedge;
- logger(DEBUG_TRAFFIC, LOG_INFO, "Sending MTU probe length %d to %s (%s)", len, n->name, n->hostname);
+ logger(mesh, MESHLINK_DEBUG, "Sending MTU probe length %d to %s", len, n->name);
- send_udppacket(n, &packet);
+ send_udppacket(mesh, n, &packet);
}
+ n->status.broadcast = false;
+
end:
- event_add(&n->mtuevent, &(struct timeval){timeout, rand() % 100000});
+ timeout_set(&mesh->loop, &n->mtutimeout, &(struct timespec) {
+ timeout, prng(mesh, TIMER_FUDGE)
+ });
}
-void send_mtu_probe(node_t *n) {
- if(!timeout_initialized(&n->mtuevent))
- timeout_set(&n->mtuevent, send_mtu_probe_handler, n);
- send_mtu_probe_handler(0, 0, n);
+void send_mtu_probe(meshlink_handle_t *mesh, node_t *n) {
+ timeout_add(&mesh->loop, &n->mtutimeout, send_mtu_probe_handler, n, &(struct timespec) {
+ 1, 0
+ });
+ send_mtu_probe_handler(&mesh->loop, n);
}
-static void mtu_probe_h(node_t *n, vpn_packet_t *packet, length_t len) {
- logger(DEBUG_TRAFFIC, LOG_INFO, "Got MTU probe length %d from %s (%s)", packet->len, n->name, n->hostname);
+static void mtu_probe_h(meshlink_handle_t *mesh, node_t *n, vpn_packet_t *packet, uint16_t len) {
+ if(len < 64) {
+ logger(mesh, MESHLINK_WARNING, "Got too short MTU probe length %d from %s", packet->len, n->name);
+ return;
+ }
+
+ logger(mesh, MESHLINK_DEBUG, "Got MTU probe length %d from %s", packet->len, n->name);
if(!packet->data[0]) {
+ /* It's a probe request, send back a reply */
+
packet->data[0] = 1;
- send_udppacket(n, packet);
- } else {
+
+ /* Temporarily set udp_confirmed, so that the reply is sent
+ back exactly the way it came in. */
+
+ bool udp_confirmed = n->status.udp_confirmed;
n->status.udp_confirmed = true;
+ send_udppacket(mesh, n, packet);
+ n->status.udp_confirmed = udp_confirmed;
+ } else {
+ /* It's a valid reply: now we know bidirectional communication
+ is possible using the address and socket that the reply
+ packet used. */
+
+ if(!n->status.udp_confirmed) {
+ char *address, *port;
+ sockaddr2str(&n->address, &address, &port);
+ send_request(mesh, n->nexthop->connection, NULL, "%d %s %s . -1 -1 -1 0 %s %s", ANS_KEY, n->name, n->name, address, port);
+ free(address);
+ free(port);
+ n->status.udp_confirmed = true;
+ }
+
+ /* If we haven't established the PMTU yet, restart the discovery process. */
if(n->mtuprobes > 30) {
- if(n->minmtu)
+ if(len == n->maxmtu + 8) {
+ logger(mesh, MESHLINK_INFO, "Increase in PMTU to %s detected, restarting PMTU discovery", n->name);
+ n->maxmtu = MTU;
+ n->mtuprobes = 10;
+ return;
+ }
+
+ if(n->minmtu) {
n->mtuprobes = 30;
- else
+ } else {
n->mtuprobes = 1;
+ }
}
- if(len > n->maxmtu)
+ /* If applicable, raise the minimum supported MTU */
+
+ if(len > n->maxmtu) {
len = n->maxmtu;
- if(n->minmtu < len)
- n->minmtu = len;
- }
-}
+ }
-static length_t compress_packet(uint8_t *dest, const uint8_t *source, length_t len, int level) {
- 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
+ if(n->minmtu < len) {
+ n->minmtu = len;
+ update_node_pmtu(mesh, n);
+ }
}
-
- return -1;
-}
-
-static length_t uncompress_packet(uint8_t *dest, const uint8_t *source, length_t len, int level) {
- 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;
- }
-#ifdef HAVE_ZLIB
- else {
- unsigned long destlen = MAXSIZE;
- if(uncompress(dest, &destlen, source, len) == Z_OK)
- return destlen;
- else
- return -1;
- }
-#endif
-
- return -1;
}
/* VPN packet I/O */
-static void receive_packet(node_t *n, vpn_packet_t *packet) {
- logger(DEBUG_TRAFFIC, LOG_DEBUG, "Received packet of %d bytes from %s (%s)",
- packet->len, n->name, n->hostname);
+static void receive_packet(meshlink_handle_t *mesh, node_t *n, vpn_packet_t *packet) {
+ logger(mesh, MESHLINK_DEBUG, "Received packet of %d bytes from %s", packet->len, n->name);
- n->in_packets++;
- n->in_bytes += packet->len;
+ if(n->status.blacklisted) {
+ logger(mesh, MESHLINK_WARNING, "Dropping packet from blacklisted node %s", n->name);
+ } else {
+ n->in_packets++;
+ n->in_bytes += packet->len;
- route(n, packet);
+ route(mesh, n, packet);
+ }
}
-static bool try_mac(node_t *n, const vpn_packet_t *inpkt) {
- if(n->status.sptps)
- return sptps_verify_datagram(&n->sptps, (char *)&inpkt->seqno, inpkt->len);
-
- if(!digest_active(&n->indigest) || inpkt->len < sizeof inpkt->seqno + digest_length(&n->indigest))
- return false;
-
- return digest_verify(&n->indigest, &inpkt->seqno, inpkt->len - n->indigest.maclength, (const char *)&inpkt->seqno + inpkt->len - n->indigest.maclength);
+static bool try_mac(meshlink_handle_t *mesh, node_t *n, const vpn_packet_t *inpkt) {
+ (void)mesh;
+ return sptps_verify_datagram(&n->sptps, inpkt->data, inpkt->len);
}
-static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
- vpn_packet_t pkt1, pkt2;
- vpn_packet_t *pkt[] = { &pkt1, &pkt2, &pkt1, &pkt2 };
- int nextpkt = 0;
- vpn_packet_t *outpkt = pkt[0];
- size_t outlen;
-
- if(n->status.sptps) {
- sptps_receive_data(&n->sptps, (char *)&inpkt->seqno, inpkt->len);
- return;
- }
-
- if(!cipher_active(&n->incipher)) {
- logger(DEBUG_TRAFFIC, LOG_DEBUG, "Got packet from %s (%s) but he hasn't got our key yet",
- n->name, n->hostname);
- return;
- }
-
- /* Check packet length */
+static void receive_udppacket(meshlink_handle_t *mesh, node_t *n, vpn_packet_t *inpkt) {
+ if(!n->sptps.state) {
+ if(!n->status.waitingforkey) {
+ logger(mesh, MESHLINK_DEBUG, "Got packet from %s but we haven't exchanged keys yet", n->name);
+ send_req_key(mesh, n);
+ } else {
+ logger(mesh, MESHLINK_DEBUG, "Got packet from %s but he hasn't got our key yet", n->name);
+ }
- if(inpkt->len < sizeof inpkt->seqno + digest_length(&n->indigest)) {
- logger(DEBUG_TRAFFIC, LOG_DEBUG, "Got too short packet from %s (%s)",
- n->name, n->hostname);
return;
}
- /* Check the message authentication code */
-
- 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)) {
- logger(DEBUG_TRAFFIC, LOG_DEBUG, "Got unauthenticated packet from %s (%s)", n->name, n->hostname);
- return;
- }
+ if(!sptps_receive_data(&n->sptps, inpkt->data, inpkt->len)) {
+ logger(mesh, MESHLINK_ERROR, "Could not process SPTPS data from %s: %s", n->name, strerror(errno));
}
- /* Decrypt the packet */
-
- if(cipher_active(&n->incipher)) {
- outpkt = pkt[nextpkt++];
- outlen = MAXSIZE;
-
- if(!cipher_decrypt(&n->incipher, &inpkt->seqno, inpkt->len, &outpkt->seqno, &outlen, true)) {
- logger(DEBUG_TRAFFIC, LOG_DEBUG, "Error decrypting packet from %s (%s)", n->name, n->hostname);
- return;
- }
-
- outpkt->len = outlen;
- inpkt = outpkt;
- }
-
- /* Check the sequence number */
-
- inpkt->len -= sizeof inpkt->seqno;
- inpkt->seqno = ntohl(inpkt->seqno);
-
- if(replaywin) {
- if(inpkt->seqno != n->received_seqno + 1) {
- if(inpkt->seqno >= n->received_seqno + replaywin * 8) {
- if(n->farfuture++ < replaywin >> 2) {
- logger(DEBUG_ALWAYS, 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(DEBUG_ALWAYS, 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(DEBUG_ALWAYS, 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(int i = n->received_seqno + 1; i < inpkt->seqno; i++)
- n->late[(i / 8) % replaywin] |= 1 << i % 8;
- }
- }
-
- n->farfuture = 0;
- n->late[(inpkt->seqno / 8) % replaywin] &= ~(1 << inpkt->seqno % 8);
- }
-
- if(inpkt->seqno > n->received_seqno)
- n->received_seqno = inpkt->seqno;
-
- if(n->received_seqno > MAX_SEQNO)
- regenerate_key();
-
- /* Decompress the packet */
-
- length_t origlen = inpkt->len;
-
- if(n->incompression) {
- outpkt = pkt[nextpkt++];
-
- if((outpkt->len = uncompress_packet(outpkt->data, inpkt->data, inpkt->len, n->incompression)) < 0) {
- logger(DEBUG_TRAFFIC, LOG_ERR, "Error while uncompressing packet from %s (%s)",
- n->name, n->hostname);
- return;
- }
-
- inpkt = outpkt;
-
- origlen -= MTU/64 + 20;
- }
-
- inpkt->priority = 0;
-
- if(!inpkt->data[12] && !inpkt->data[13])
- mtu_probe_h(n, inpkt, origlen);
- else
- receive_packet(n, inpkt);
}
-void receive_tcppacket(connection_t *c, const char *buffer, int len) {
- vpn_packet_t outpkt;
-
- outpkt.len = len;
- if(c->options & OPTION_TCPONLY)
- outpkt.priority = 0;
- else
- outpkt.priority = -1;
- memcpy(outpkt.data, buffer, len);
-
- receive_packet(c->node, &outpkt);
-}
-
-static void send_sptps_packet(node_t *n, vpn_packet_t *origpkt) {
+static void send_sptps_packet(meshlink_handle_t *mesh, node_t *n, vpn_packet_t *origpkt) {
if(!n->status.validkey) {
- logger(DEBUG_TRAFFIC, LOG_INFO, "No valid key known yet for %s (%s)", n->name, n->hostname);
- if(!n->status.waitingforkey)
- send_req_key(n);
- else if(n->last_req_key + 10 < time(NULL)) {
- logger(DEBUG_ALWAYS, LOG_DEBUG, "No key from %s after 10 seconds, restarting SPTPS", n->name);
+ logger(mesh, MESHLINK_INFO, "No valid key known yet for %s", n->name);
+
+ if(!n->status.waitingforkey) {
+ send_req_key(mesh, n);
+ } else if(n->last_req_key + 10 < mesh->loop.now.tv_sec) {
+ logger(mesh, MESHLINK_DEBUG, "No key from %s after 10 seconds, restarting SPTPS", n->name);
sptps_stop(&n->sptps);
n->status.waitingforkey = false;
- send_req_key(n);
+ send_req_key(mesh, n);
}
- return;
- }
-
- uint8_t type = 0;
- int offset = 0;
- if(!(origpkt->data[12] | origpkt->data[13])) {
- sptps_send_record(&n->sptps, PKT_PROBE, (char *)origpkt->data, origpkt->len);
return;
}
- if(routing_mode == RMODE_ROUTER)
- offset = 14;
- else
- type = PKT_MAC;
+ uint8_t type = 0;
- if(origpkt->len < offset)
+ // If it's a probe, send it immediately without trying to compress it.
+ if(origpkt->probe) {
+ sptps_send_record(&n->sptps, PKT_PROBE, origpkt->data, origpkt->len);
return;
-
- vpn_packet_t outpkt;
-
- if(n->outcompression) {
- int len = compress_packet(outpkt.data + offset, origpkt->data + offset, origpkt->len - offset, n->outcompression);
- if(len < 0) {
- logger(DEBUG_TRAFFIC, LOG_ERR, "Error while compressing packet to %s (%s)", n->name, n->hostname);
- } else if(len < origpkt->len - offset) {
- outpkt.len = len + offset;
- origpkt = &outpkt;
- type |= PKT_COMPRESSED;
- }
}
- sptps_send_record(&n->sptps, type, (char *)origpkt->data + offset, origpkt->len - offset);
+ sptps_send_record(&n->sptps, type, origpkt->data, origpkt->len);
return;
}
-static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
- vpn_packet_t pkt1, pkt2;
- vpn_packet_t *pkt[] = { &pkt1, &pkt2, &pkt1, &pkt2 };
- vpn_packet_t *inpkt = origpkt;
- int nextpkt = 0;
- vpn_packet_t *outpkt;
- int origlen = origpkt->len;
- size_t outlen;
-#if defined(SOL_IP) && defined(IP_TOS)
- static int priority = 0;
-#endif
- int origpriority = origpkt->priority;
+static void choose_udp_address(meshlink_handle_t *mesh, const node_t *n, const sockaddr_t **sa, int *sock) {
+ /* Latest guess */
+ *sa = &n->address;
+ *sock = n->sock;
- if(!n->status.reachable) {
- logger(DEBUG_TRAFFIC, LOG_INFO, "Trying to send UDP packet to unreachable node %s (%s)", n->name, n->hostname);
+ /* If the UDP address is confirmed, use it. */
+ if(n->status.udp_confirmed) {
return;
}
- if(n->status.sptps)
- return send_sptps_packet(n, origpkt);
-
- /* Make sure we have a valid key */
-
- if(!n->status.validkey) {
- time_t now = time(NULL);
-
- logger(DEBUG_TRAFFIC, LOG_INFO,
- "No valid key known yet for %s (%s), forwarding via TCP",
- n->name, n->hostname);
-
- if(n->last_req_key + 10 <= now) {
- send_req_key(n);
- n->last_req_key = now;
- }
-
- send_tcppacket(n->nexthop->connection, origpkt);
+ /* Send every third packet to n->address; that could be set
+ to the node's reflexive UDP address discovered during key
+ exchange. */
+ if(++mesh->udp_choice >= 3) {
+ mesh->udp_choice = 0;
return;
}
- if(n->options & OPTION_PMTU_DISCOVERY && inpkt->len > n->minmtu && (inpkt->data[12] | inpkt->data[13])) {
- logger(DEBUG_TRAFFIC, LOG_INFO,
- "Packet for %s (%s) larger than minimum MTU, forwarding via %s",
- n->name, n->hostname, n != n->nexthop ? n->nexthop->name : "TCP");
+ /* Otherwise, address are found in edges to this node.
+ So we pick a random edge and a random socket. */
- if(n != n->nexthop)
- send_packet(n->nexthop, origpkt);
- else
- send_tcppacket(n->nexthop->connection, origpkt);
+ int i = 0;
+ int j = prng(mesh, n->edge_tree->count);
+ edge_t *candidate = NULL;
- return;
- }
-
- /* Compress the packet */
-
- if(n->outcompression) {
- outpkt = pkt[nextpkt++];
-
- if((outpkt->len = compress_packet(outpkt->data, inpkt->data, inpkt->len, n->outcompression)) < 0) {
- logger(DEBUG_TRAFFIC, LOG_ERR, "Error while compressing packet to %s (%s)",
- n->name, n->hostname);
- return;
- }
-
- inpkt = outpkt;
- }
-
- /* Add sequence number */
-
- inpkt->seqno = htonl(++(n->sent_seqno));
- inpkt->len += sizeof inpkt->seqno;
-
- /* Encrypt the packet */
-
- if(cipher_active(&n->outcipher)) {
- outpkt = pkt[nextpkt++];
- outlen = MAXSIZE;
-
- if(!cipher_encrypt(&n->outcipher, &inpkt->seqno, inpkt->len, &outpkt->seqno, &outlen, true)) {
- logger(DEBUG_TRAFFIC, LOG_ERR, "Error while encrypting packet to %s (%s)", n->name, n->hostname);
- goto end;
+ for splay_each(edge_t, e, n->edge_tree) {
+ if(i++ == j) {
+ candidate = e->reverse;
+ break;
}
-
- outpkt->len = outlen;
- inpkt = outpkt;
}
- /* Add the message authentication code */
-
- if(digest_active(&n->outdigest)) {
- digest_create(&n->outdigest, &inpkt->seqno, inpkt->len, (char *)&inpkt->seqno + inpkt->len);
- inpkt->len += digest_length(&n->outdigest);
+ if(candidate) {
+ *sa = &candidate->address;
+ *sock = prng(mesh, mesh->listen_sockets);
}
- /* Send the packet */
-
- sockaddr_t *sa;
- int sock;
- sockaddr_t broadcast;
-
- /* Overloaded use of priority field: -1 means local broadcast */
-
- if(origpriority == -1 && n->prevedge) {
- broadcast.in.sin_family = AF_INET;
- broadcast.in.sin_addr.s_addr = -1;
- broadcast.in.sin_port = n->prevedge->address.in.sin_port;
- sa = &broadcast;
- sock = 0;
- } else {
- if(origpriority == -1)
- origpriority = 0;
-
- if(n->status.udp_confirmed) {
- /* Address of this node is confirmed, so use it. */
- sa = &n->address;
- sock = n->sock;
- } else {
- /* Otherwise, go through the list of known addresses of
- this node. The first address we try is always the
- one in n->address; that could be set to the node's
- reflexive UDP address discovered during key
- exchange. The other known addresses are those found
- in edges to this node. */
-
- static unsigned int i;
- int j = 0;
- edge_t *candidate = NULL;
-
- if(i) {
- for splay_each(edge_t, e, edge_weight_tree) {
- if(e->to != n)
- continue;
- j++;
- if(!candidate || j == i)
- candidate = e;
- }
- }
-
- if(!candidate) {
- sa = &n->address;
- sock = n->sock;
- } else {
- sa = &candidate->address;
- sock = rand() % listen_sockets;
+ /* Make sure we have a suitable socket for the chosen address */
+ if(mesh->listen_socket[*sock].sa.sa.sa_family != (*sa)->sa.sa_family) {
+ for(int i = 0; i < mesh->listen_sockets; i++) {
+ if(mesh->listen_socket[i].sa.sa.sa_family == (*sa)->sa.sa_family) {
+ *sock = i;
+ break;
}
-
- if(i++)
- if(i > j)
- i = 0;
}
}
+}
- /* Determine which socket we have to use */
-
- if(sa->sa.sa_family != listen_socket[sock].sa.sa.sa_family)
- for(sock = 0; sock < listen_sockets; sock++)
- if(sa->sa.sa_family == listen_socket[sock].sa.sa.sa_family)
- break;
-
- if(sock >= listen_sockets)
- sock = 0;
-
- if(!n->status.udp_confirmed)
- n->sock = sock;
+static void choose_broadcast_address(meshlink_handle_t *mesh, const node_t *n, const sockaddr_t **sa, int *sock) {
+ *sock = prng(mesh, mesh->listen_sockets);
+ sockaddr_t *broadcast_sa = &mesh->listen_socket[*sock].broadcast_sa;
-#if defined(SOL_IP) && defined(IP_TOS)
- if(priorityinheritance && origpriority != priority
- && listen_socket[n->sock].sa.sa.sa_family == AF_INET) {
- priority = origpriority;
- logger(DEBUG_TRAFFIC, LOG_DEBUG, "Setting outgoing packet priority to %d", priority);
- if(setsockopt(listen_socket[n->sock].udp, SOL_IP, IP_TOS, &priority, sizeof(priority))) /* SO_PRIORITY doesn't seem to work */
- logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setsockopt", strerror(errno));
+ if(broadcast_sa->sa.sa_family == AF_INET6) {
+ broadcast_sa->in6.sin6_port = n->prevedge->address.in.sin_port;
+ } else {
+ broadcast_sa->in.sin_port = n->prevedge->address.in.sin_port;
}
-#endif
- socklen_t sl = SALEN(n->address.sa);
+ *sa = broadcast_sa;
+}
- if(sendto(listen_socket[sock].udp, (char *) &inpkt->seqno, inpkt->len, 0, &sa->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(DEBUG_TRAFFIC, LOG_WARNING, "Error sending packet to %s (%s): %s", n->name, n->hostname, sockstrerror(sockerrno));
+static void send_udppacket(meshlink_handle_t *mesh, node_t *n, vpn_packet_t *origpkt) {
+ if(!n->status.reachable) {
+ logger(mesh, MESHLINK_INFO, "Trying to send UDP packet to unreachable node %s", n->name);
+ return;
}
-end:
- origpkt->len = origlen;
+ send_sptps_packet(mesh, n, origpkt);
}
-bool send_sptps_data(void *handle, uint8_t type, const char *data, size_t len) {
+bool send_sptps_data(void *handle, uint8_t type, const void *data, size_t len) {
+ assert(handle);
+ assert(data);
+ assert(len);
+
node_t *to = handle;
+ meshlink_handle_t *mesh = to->mesh;
/* Send it via TCP if it is a handshake packet, TCPOnly is in use, or this packet is larger than the MTU. */
- if(type >= SPTPS_HANDSHAKE || ((myself->options | to->options) & OPTION_TCPONLY) || (type != PKT_PROBE && len > to->minmtu)) {
+ if(type >= SPTPS_HANDSHAKE || (type != PKT_PROBE && (len - 21) > to->minmtu)) {
char buf[len * 4 / 3 + 5];
b64encode(data, buf, len);
+
/* If no valid key is known yet, send the packets using ANS_KEY requests,
to ensure we get to learn the reflexive UDP address. */
- if(!to->status.validkey)
- return send_request(to->nexthop->connection, "%d %s %s %s -1 -1 -1 %d", ANS_KEY, myself->name, to->name, buf, myself->incompression);
- else
- return send_request(to->nexthop->connection, "%d %s %s %d %s", REQ_KEY, myself->name, to->name, REQ_SPTPS, buf);
+ if(!to->status.validkey) {
+ return send_request(mesh, to->nexthop->connection, NULL, "%d %s %s %s -1 -1 -1 %d", ANS_KEY, mesh->self->name, to->name, buf, 0);
+ } else {
+ return send_request(mesh, to->nexthop->connection, NULL, "%d %s %s %d %s", REQ_KEY, mesh->self->name, to->name, REQ_SPTPS, buf);
+ }
}
/* Otherwise, send the packet via UDP */
- struct sockaddr *sa;
- socklen_t sl;
+ const sockaddr_t *sa;
int sock;
- sa = &(to->address.sa);
- sl = SALEN(to->address.sa);
- sock = to->sock;
+ if(to->status.broadcast) {
+ choose_broadcast_address(mesh, to, &sa, &sock);
+ } else {
+ choose_udp_address(mesh, to, &sa, &sock);
+ }
- if(sendto(listen_socket[sock].udp, data, len, 0, sa, sl) < 0 && !sockwouldblock(sockerrno)) {
+ if(sendto(mesh->listen_socket[sock].udp.fd, data, len, 0, &sa->sa, SALEN(sa->sa)) < 0 && !sockwouldblock(sockerrno)) {
if(sockmsgsize(sockerrno)) {
- if(to->maxmtu >= len)
+ if(to->maxmtu >= len) {
to->maxmtu = len - 1;
- if(to->mtu >= len)
+ }
+
+ if(to->mtu >= len) {
to->mtu = len - 1;
+ }
} else {
- logger(DEBUG_TRAFFIC, LOG_WARNING, "Error sending UDP SPTPS packet to %s (%s): %s", to->name, to->hostname, sockstrerror(sockerrno));
+ logger(mesh, MESHLINK_WARNING, "Error sending UDP SPTPS packet to %s: %s", to->name, sockstrerror(sockerrno));
return false;
}
}
return true;
}
-bool receive_sptps_record(void *handle, uint8_t type, const char *data, uint16_t len) {
+bool receive_sptps_record(void *handle, uint8_t type, const void *data, uint16_t len) {
+ assert(handle);
+ assert(!data || len);
+
node_t *from = handle;
+ meshlink_handle_t *mesh = from->mesh;
if(type == SPTPS_HANDSHAKE) {
if(!from->status.validkey) {
+ logger(mesh, MESHLINK_INFO, "SPTPS key exchange with %s successful", from->name);
from->status.validkey = true;
from->status.waitingforkey = false;
- logger(DEBUG_META, LOG_INFO, "SPTPS key exchange with %s (%s) succesful", from->name, from->hostname);
+
+ if(from->utcp) {
+ utcp_reset_timers(from->utcp);
+ }
}
+
return true;
}
- if(len > MTU) {
- logger(DEBUG_ALWAYS, LOG_ERR, "Packet from %s (%s) larger than maximum supported size (%d > %d)", from->name, from->hostname, len, MTU);
+ if(len > MAXSIZE) {
+ logger(mesh, MESHLINK_ERROR, "Packet from %s larger than maximum supported size (%d > %d)", from->name, len, MAXSIZE);
return false;
}
if(type == PKT_PROBE) {
inpkt.len = len;
+ inpkt.probe = true;
memcpy(inpkt.data, data, len);
- mtu_probe_h(from, &inpkt, len);
+ mtu_probe_h(mesh, from, &inpkt, len);
return true;
+ } else {
+ inpkt.probe = false;
}
- if(type & ~(PKT_COMPRESSED | PKT_MAC)) {
- logger(DEBUG_ALWAYS, LOG_ERR, "Unexpected SPTPS record type %d len %d from %s (%s)", type, len, from->name, from->hostname);
- return false;
- }
-
- /* Check if we have the headers we need */
- if(routing_mode != RMODE_ROUTER && !(type & PKT_MAC)) {
- logger(DEBUG_TRAFFIC, LOG_ERR, "Received packet from %s (%s) without MAC header (maybe Mode is not set correctly)", from->name, from->hostname);
+ if(type & ~(PKT_COMPRESSED)) {
+ logger(mesh, MESHLINK_ERROR, "Unexpected SPTPS record type %d len %d from %s", type, len, from->name);
return false;
- } else if(routing_mode == RMODE_ROUTER && (type & PKT_MAC)) {
- logger(DEBUG_TRAFFIC, LOG_WARNING, "Received packet from %s (%s) with MAC header (maybe Mode is not set correctly)", from->name, from->hostname);
}
- int offset = (type & PKT_MAC) ? 0 : 14;
if(type & PKT_COMPRESSED) {
- len = uncompress_packet(inpkt.data + offset, (const uint8_t *)data, len, from->incompression);
- if(len < 0) {
- return false;
- } else {
- inpkt.len = len + offset;
- }
- if(inpkt.len > MAXSIZE)
- abort();
- } else {
- memcpy(inpkt.data + offset, data, len);
- inpkt.len = len + offset;
+ logger(mesh, MESHLINK_ERROR, "Error while decompressing packet from %s", from->name);
+ return false;
}
- /* Generate the Ethernet packet type if necessary */
- if(offset) {
- switch(inpkt.data[14] >> 4) {
- case 4:
- inpkt.data[12] = 0x08;
- inpkt.data[13] = 0x00;
- break;
- case 6:
- inpkt.data[12] = 0x86;
- inpkt.data[13] = 0xDD;
- break;
- default:
- logger(DEBUG_TRAFFIC, LOG_ERR,
- "Unknown IP version %d while reading packet from %s (%s)",
- inpkt.data[14] >> 4, from->name, from->hostname);
- return false;
- }
- }
+ memcpy(inpkt.data, data, len); // TODO: get rid of memcpy
+ inpkt.len = len;
- receive_packet(from, &inpkt);
+ receive_packet(mesh, from, &inpkt);
return true;
}
/*
send a packet to the given vpn ip.
*/
-void send_packet(node_t *n, vpn_packet_t *packet) {
- node_t *via;
-
- if(n == myself) {
- if(overwrite_mac)
- memcpy(packet->data, mymac.x, ETH_ALEN);
+void send_packet(meshlink_handle_t *mesh, node_t *n, vpn_packet_t *packet) {
+ if(n == mesh->self) {
n->out_packets++;
n->out_bytes += packet->len;
- devops.write(packet);
+ // TODO: send to application
return;
}
- logger(DEBUG_TRAFFIC, LOG_ERR, "Sending packet of %d bytes to %s (%s)",
- packet->len, n->name, n->hostname);
+ logger(mesh, MESHLINK_DEBUG, "Sending packet of %d bytes to %s", packet->len, n->name);
if(!n->status.reachable) {
- logger(DEBUG_TRAFFIC, LOG_INFO, "Node %s (%s) is not reachable",
- n->name, n->hostname);
+ logger(mesh, MESHLINK_WARNING, "Node %s is not reachable", n->name);
return;
}
n->out_packets++;
n->out_bytes += packet->len;
+ n->status.want_udp = true;
- if(n->status.sptps) {
- send_sptps_packet(n, packet);
- return;
- }
-
- via = (packet->priority == -1 || n->via == myself) ? n->nexthop : n->via;
-
- if(via != n)
- logger(DEBUG_TRAFFIC, LOG_INFO, "Sending packet to %s via %s (%s)",
- n->name, via->name, n->via->hostname);
-
- if(packet->priority == -1 || ((myself->options | via->options) & OPTION_TCPONLY)) {
- if(!send_tcppacket(via->connection, packet))
- terminate_connection(via->connection, true);
- } else
- send_udppacket(via, packet);
-}
-
-/* Broadcast a packet using the minimum spanning tree */
-
-void broadcast_packet(const node_t *from, vpn_packet_t *packet) {
- // 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;
-
- logger(DEBUG_TRAFFIC, LOG_INFO, "Broadcasting packet of %d bytes from %s (%s)",
- packet->len, from->name, from->hostname);
-
- 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 list_each(connection_t, c, connection_list)
- 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 splay_each(node_t, n, node_tree)
- if(n->status.reachable && ((n->via == myself && n->nexthop == n) || n->via == n))
- send_packet(n, packet);
- break;
-
- default:
- break;
- }
+ send_sptps_packet(mesh, n, packet);
+ return;
}
-static node_t *try_harder(const sockaddr_t *from, const vpn_packet_t *pkt) {
+static node_t *try_harder(meshlink_handle_t *mesh, const sockaddr_t *from, const vpn_packet_t *pkt) {
node_t *n = NULL;
bool hard = false;
- static time_t last_hard_try = 0;
- time_t now = time(NULL);
- for splay_each(edge_t, e, edge_weight_tree) {
- if(!e->to->status.reachable || e->to == myself)
+ for splay_each(edge_t, e, mesh->edges) {
+ if(!e->to->status.reachable || e->to == mesh->self) {
continue;
+ }
if(sockaddrcmp_noport(from, &e->address)) {
- if(last_hard_try == now)
+ if(mesh->last_hard_try == mesh->loop.now.tv_sec) {
continue;
+ }
+
hard = true;
}
- if(!try_mac(e->to, pkt))
+ if(!try_mac(mesh, e->to, pkt)) {
continue;
+ }
n = e->to;
break;
}
- if(hard)
- last_hard_try = now;
+ if(hard) {
+ mesh->last_hard_try = mesh->loop.now.tv_sec;
+ }
- last_hard_try = now;
return n;
}
-void handle_incoming_vpn_data(int sock, short events, void *data) {
+void handle_incoming_vpn_data(event_loop_t *loop, void *data, int flags) {
+ (void)flags;
+ meshlink_handle_t *mesh = loop->data;
+ listen_socket_t *ls = data;
vpn_packet_t pkt;
char *hostname;
- sockaddr_t from = {{0}};
- socklen_t fromlen = sizeof from;
+ sockaddr_t from;
+ socklen_t fromlen = sizeof(from);
node_t *n;
int len;
- len = recvfrom(sock, (char *) &pkt.seqno, MAXSIZE, 0, &from.sa, &fromlen);
+ memset(&from, 0, sizeof(from));
+
+ len = recvfrom(ls->udp.fd, pkt.data, MAXSIZE, 0, &from.sa, &fromlen);
if(len <= 0 || len > MAXSIZE) {
- if(!sockwouldblock(sockerrno))
- logger(DEBUG_ALWAYS, LOG_ERR, "Receiving packet failed: %s", sockstrerror(sockerrno));
+ if(!sockwouldblock(sockerrno)) {
+ logger(mesh, MESHLINK_ERROR, "Receiving packet failed: %s", sockstrerror(sockerrno));
+ }
+
return;
}
sockaddrunmap(&from); /* Some braindead IPv6 implementations do stupid things. */
- n = lookup_node_udp(&from);
+ n = lookup_node_udp(mesh, &from);
if(!n) {
- n = try_harder(&from, &pkt);
- if(n)
- update_node_udp(n, &from);
- else if(debug_level >= DEBUG_PROTOCOL) {
+ n = try_harder(mesh, &from, &pkt);
+
+ if(n) {
+ update_node_udp(mesh, n, &from);
+ } else if(mesh->log_level <= MESHLINK_WARNING) {
hostname = sockaddr2hostname(&from);
- logger(DEBUG_PROTOCOL, LOG_WARNING, "Received UDP packet from unknown source %s", hostname);
+ logger(mesh, MESHLINK_WARNING, "Received UDP packet from unknown source %s", hostname);
free(hostname);
return;
- }
- else
+ } else {
return;
+ }
}
- n->sock = (intptr_t)data;
-
- receive_udppacket(n, &pkt);
-}
-
-void handle_device_data(int sock, short events, void *data) {
- vpn_packet_t packet;
+ if(n->status.blacklisted) {
+ logger(mesh, MESHLINK_WARNING, "Dropping packet from blacklisted node %s", n->name);
+ return;
+ }
- packet.priority = 0;
+ n->sock = ls - mesh->listen_socket;
- if(devops.read(&packet)) {
- myself->in_packets++;
- myself->in_bytes += packet.len;
- route(myself, &packet);
- }
+ receive_udppacket(mesh, n, &pkt);
}
projects / meshlink / blobdiff