/*
net_packet.c -- Handles in- and outgoing VPN packets
- Copyright (C) 1998-2005 Ivo Timmermans,
- 2000-2011 Guus Sliepen <guus@tinc-vpn.org>
- 2010 Timothy Redaelli <timothy@redaelli.eu>
- 2010 Brandon Black <blblack@gmail.com>
+ Copyright (C) 2014 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 "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 "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 *);
+static void send_udppacket(meshlink_handle_t *mesh, node_t *, vpn_packet_t *);
unsigned replaywin = 16;
-bool localdiscovery = false;
#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.
+
+ 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, a fourth packet is added to each batch,
+ 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;
- vpn_packet_t packet;
- int len, i;
int timeout = 1;
-
+
n->mtuprobes++;
if(!n->status.reachable || !n->status.validkey) {
- ifdebug(TRAFFIC) logger(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 (%s)", n->name, n->hostname);
n->mtuprobes = 0;
return;
}
if(n->mtuprobes > 32) {
if(!n->minmtu) {
n->mtuprobes = 31;
- timeout = pinginterval;
+ timeout = mesh->pinginterval;
goto end;
}
- ifdebug(TRAFFIC) logger(LOG_INFO, "%s (%s) did not respond to UDP ping, restarting PMTU discovery", n->name, n->hostname);
+ logger(mesh, MESHLINK_INFO, "%s (%s) did not respond to UDP ping, restarting PMTU discovery", n->name, n->hostname);
+ n->status.udp_confirmed = false;
n->mtuprobes = 1;
n->minmtu = 0;
n->maxmtu = MTU;
}
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);
+ logger(mesh, MESHLINK_INFO, "No response to MTU probes from %s (%s)", n->name, n->hostname);
n->mtuprobes = 31;
}
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);
+ logger(mesh, MESHLINK_INFO, "Fixing MTU of %s (%s) to %d after %d probes", n->name, n->hostname, n->mtu, n->mtuprobes);
n->mtuprobes = 31;
}
if(n->mtuprobes == 31) {
- timeout = pinginterval;
+ timeout = mesh->pinginterval;
goto end;
} else if(n->mtuprobes == 32) {
- timeout = pingtimeout;
+ timeout = mesh->pingtimeout;
}
- for(i = 0; i < 3 + localdiscovery; i++) {
- if(n->maxmtu <= n->minmtu)
+ for(int i = 0; i < 4 + mesh->localdiscovery; i++) {
+ int len;
+
+ 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
+ } else {
len = n->minmtu + 1 + rand() % (n->maxmtu - n->minmtu);
+ }
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;
- packet.priority = i < 3 ? 0 : -1;
+ n->status.broadcast = i >= 4 && n->mtuprobes <= 10 && n->prevedge;
- ifdebug(TRAFFIC) logger(LOG_INFO, "Sending MTU probe length %d to %s (%s)", len, n->name, n->hostname);
+ logger(mesh, MESHLINK_INFO, "Sending MTU probe length %d to %s (%s)", len, n->name, n->hostname);
- send_udppacket(n, &packet);
+ send_udppacket(mesh, n, &packet);
}
+ n->status.broadcast = false;
+ n->probe_counter = 0;
+ gettimeofday(&n->probe_time, NULL);
+
+ /* Calculate the packet loss of incoming traffic by comparing the rate of
+ packets received to the rate with which the sequence number has increased.
+ */
+
+ if(n->received > n->prev_received)
+ n->packetloss = 1.0 - (n->received - n->prev_received) / (float)(n->received_seqno - n->prev_received_seqno);
+ else
+ n->packetloss = n->received_seqno <= n->prev_received_seqno;
+
+ n->prev_received_seqno = n->received_seqno;
+ n->prev_received = n->received;
+
end:
- event_add(&n->mtuevent, &(struct timeval){timeout, 0});
+ timeout_set(&mesh->loop, &n->mtutimeout, &(struct timeval){timeout, rand() % 100000});
}
-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 timeval){1, 0});
+ send_mtu_probe_handler(&mesh->loop, n);
}
-static void mtu_probe_h(node_t *n, vpn_packet_t *packet, length_t len) {
- ifdebug(TRAFFIC) logger(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) {
+ logger(mesh, MESHLINK_INFO, "Got MTU probe length %d from %s (%s)", packet->len, n->name, n->hostname);
if(!packet->data[0]) {
+ /* It's a probe request, send back a reply */
+
packet->data[0] = 1;
- send_udppacket(n, packet);
+
+ /* 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. */
+
+ n->status.udp_confirmed = true;
+
+ /* If we haven't established the PMTU yet, restart the discovery process. */
+
if(n->mtuprobes > 30) {
+ if (len == n->maxmtu + 8) {
+ logger(mesh, MESHLINK_INFO, "Increase in PMTU to %s (%s) detected, restarting PMTU discovery", n->name, n->hostname);
+ n->maxmtu = MTU;
+ n->mtuprobes = 10;
+ return;
+ }
+
if(n->minmtu)
n->mtuprobes = 30;
else
n->mtuprobes = 1;
}
+ /* If applicable, raise the minimum supported MTU */
+
if(len > n->maxmtu)
len = n->maxmtu;
if(n->minmtu < len)
n->minmtu = len;
+
+ /* Calculate RTT and bandwidth.
+ The RTT is the time between the MTU probe burst was sent and the first
+ reply is received. The bandwidth is measured using the time between the
+ arrival of the first and third probe reply.
+ */
+
+ struct timeval now, diff;
+ gettimeofday(&now, NULL);
+ timersub(&now, &n->probe_time, &diff);
+
+ n->probe_counter++;
+
+ if(n->probe_counter == 1) {
+ n->rtt = diff.tv_sec + diff.tv_usec * 1e-6;
+ n->probe_time = now;
+ } else if(n->probe_counter == 3) {
+ n->bandwidth = 2.0 * len / (diff.tv_sec + diff.tv_usec * 1e-6);
+ logger(mesh, MESHLINK_DEBUG, "%s (%s) RTT %.2f ms, burst bandwidth %.3f Mbit/s, rx packet loss %.2f %%", n->name, n->hostname, n->rtt * 1e3, n->bandwidth * 8e-6, n->packetloss * 1e2);
+ }
}
}
-static length_t compress_packet(uint8_t *dest, const uint8_t *source, length_t len, int level) {
+static uint16_t compress_packet(uint8_t *dest, const uint8_t *source, uint16_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;
#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) {
+static uint16_t uncompress_packet(uint8_t *dest, const uint8_t *source, uint16_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
/* VPN packet I/O */
-static void receive_packet(node_t *n, vpn_packet_t *packet) {
- ifdebug(TRAFFIC) logger(LOG_DEBUG, "Received packet of %d bytes from %s (%s)",
+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 (%s)",
packet->len, n->name, n->hostname);
+ 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(!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) {
+ 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(!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);
+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 (%s) but we haven't exchanged keys yet", n->name, n->hostname);
+ send_req_key(mesh, n);
+ } else {
+ logger(mesh, MESHLINK_DEBUG, "Got packet from %s (%s) but he hasn't got our key yet", n->name, n->hostname);
+ }
return;
}
+ sptps_receive_data(&n->sptps, inpkt->data, inpkt->len);
+}
- /* Check packet length */
+void receive_tcppacket(meshlink_handle_t *mesh, connection_t *c, const char *buffer, int len) {
+ vpn_packet_t outpkt;
- 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);
+ if(len > sizeof outpkt.data)
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)) {
- ifdebug(TRAFFIC) logger(LOG_DEBUG, "Got unauthenticated packet from %s (%s)", n->name, n->hostname);
- return;
- }
- }
- /* Decrypt the packet */
+ outpkt.len = len;
+ outpkt.tcp = true;
+ memcpy(outpkt.data, buffer, len);
- if(cipher_active(&n->incipher)) {
- outpkt = pkt[nextpkt++];
- outlen = MAXSIZE;
+ receive_packet(mesh, c->node, &outpkt);
+}
- 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;
- 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(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(int i = n->received_seqno + 1; i < inpkt->seqno; i++)
- n->late[(i / 8) % replaywin] |= 1 << i % 8;
- }
+static void send_sptps_packet(meshlink_handle_t *mesh, node_t *n, vpn_packet_t *origpkt) {
+ if(!n->status.validkey) {
+ logger(mesh, MESHLINK_INFO, "No valid key known yet for %s (%s)", n->name, n->hostname);
+ 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(mesh, n);
}
-
- n->farfuture = 0;
- n->late[(inpkt->seqno / 8) % replaywin] &= ~(1 << inpkt->seqno % 8);
+ return;
}
- if(inpkt->seqno > n->received_seqno)
- n->received_seqno = inpkt->seqno;
-
- if(n->received_seqno > MAX_SEQNO)
- regenerate_key();
-
- /* Decompress the packet */
+ uint8_t type = 0;
- length_t origlen = inpkt->len;
+ // 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;
+ }
- if(n->incompression) {
- outpkt = pkt[nextpkt++];
+ vpn_packet_t outpkt;
- if((outpkt->len = uncompress_packet(outpkt->data, inpkt->data, inpkt->len, n->incompression)) < 0) {
- ifdebug(TRAFFIC) logger(LOG_ERR, "Error while uncompressing packet from %s (%s)",
- n->name, n->hostname);
- return;
+ if(n->outcompression) {
+ int len = compress_packet(outpkt.data, origpkt->data, origpkt->len, n->outcompression);
+ if(len < 0) {
+ logger(mesh, MESHLINK_ERROR, "Error while compressing packet to %s (%s)", n->name, n->hostname);
+ } else if(len < origpkt->len) {
+ outpkt.len = len;
+ origpkt = &outpkt;
+ type |= PKT_COMPRESSED;
}
-
- 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);
+ sptps_send_record(&n->sptps, type, origpkt->data, origpkt->len);
+ return;
}
-void receive_tcppacket(connection_t *c, const char *buffer, int len) {
- vpn_packet_t outpkt;
+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;
- 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);
-}
+ /* If the UDP address is confirmed, use it. */
+ if(n->status.udp_confirmed)
+ 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;
- int origpriority = origpkt->priority;
-#endif
+ /* Send every third packet to n->address; that could be set
+ to the node's reflexive UDP address discovered during key
+ exchange. */
- if(!n->status.reachable) {
- ifdebug(TRAFFIC) logger(LOG_INFO, "Trying to send UDP packet to unreachable node %s (%s)", n->name, n->hostname);
+ static int x = 0;
+ if(++x >= 3) {
+ x = 0;
return;
}
- /* Make sure we have a valid key */
-
- if(!n->status.validkey) {
- time_t now = time(NULL);
+ /* Otherwise, address are found in edges to this node.
+ So we pick a random edge and a random socket. */
- ifdebug(TRAFFIC) logger(LOG_INFO,
- "No valid key known yet for %s (%s), forwarding via TCP",
- n->name, n->hostname);
+ int i = 0;
+ int j = rand() % n->edge_tree->count;
+ edge_t *candidate = NULL;
- if(n->last_req_key + 10 <= now) {
- send_req_key(n);
- n->last_req_key = now;
+ for splay_each(edge_t, e, n->edge_tree) {
+ if(i++ == j) {
+ candidate = e->reverse;
+ break;
}
+ }
- send_tcppacket(n->nexthop->connection, origpkt);
-
- return;
+ if(candidate) {
+ *sa = &candidate->address;
+ *sock = rand() % mesh->listen_sockets;
}
- 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 %s",
- n->name, n->hostname, n != n->nexthop ? n->nexthop->name : "TCP");
+ /* 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(n != n->nexthop)
- send_packet(n->nexthop, origpkt);
- else
- send_tcppacket(n->nexthop->connection, origpkt);
+static void choose_broadcast_address(meshlink_handle_t *mesh, const node_t *n, const sockaddr_t **sa, int *sock) {
+ static sockaddr_t broadcast_ipv4 = {
+ .in = {
+ .sin_family = AF_INET,
+ .sin_addr.s_addr = -1,
+ }
+ };
+
+ static sockaddr_t broadcast_ipv6 = {
+ .in6 = {
+ .sin6_family = AF_INET6,
+ .sin6_addr.s6_addr[0x0] = 0xff,
+ .sin6_addr.s6_addr[0x1] = 0x02,
+ .sin6_addr.s6_addr[0xf] = 0x01,
+ }
+ };
+
+ *sock = rand() % mesh->listen_sockets;
+
+ if(mesh->listen_socket[*sock].sa.sa.sa_family == AF_INET6) {
+ if(mesh->localdiscovery_address.sa.sa_family == AF_INET6) {
+ mesh->localdiscovery_address.in6.sin6_port = n->prevedge->address.in.sin_port;
+ *sa = &mesh->localdiscovery_address;
+ } else {
+ broadcast_ipv6.in6.sin6_port = n->prevedge->address.in.sin_port;
+ broadcast_ipv6.in6.sin6_scope_id = mesh->listen_socket[*sock].sa.in6.sin6_scope_id;
+ *sa = &broadcast_ipv6;
+ }
+ } else {
+ if(mesh->localdiscovery_address.sa.sa_family == AF_INET) {
+ mesh->localdiscovery_address.in.sin_port = n->prevedge->address.in.sin_port;
+ *sa = &mesh->localdiscovery_address;
+ } else {
+ broadcast_ipv4.in.sin_port = n->prevedge->address.in.sin_port;
+ *sa = &broadcast_ipv4;
+ }
+ }
+}
+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 (%s)", n->name, n->hostname);
return;
}
- /* Compress the packet */
-
- if(n->outcompression) {
- outpkt = pkt[nextpkt++];
+ return send_sptps_packet(mesh, n, origpkt);
+}
- if((outpkt->len = compress_packet(outpkt->data, inpkt->data, inpkt->len, n->outcompression)) < 0) {
- ifdebug(TRAFFIC) logger(LOG_ERR, "Error while compressing packet to %s (%s)",
- n->name, n->hostname);
- return;
+bool send_sptps_data(void *handle, uint8_t type, const void *data, size_t 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 || ((mesh->self->options | to->options) & OPTION_TCPONLY) || (type != PKT_PROBE && len > 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) {
+ to->incompression = mesh->self->incompression;
+ return send_request(mesh, to->nexthop->connection, "%d %s %s %s -1 -1 -1 %d", ANS_KEY, mesh->self->name, to->name, buf, to->incompression);
+ } else {
+ return send_request(mesh, to->nexthop->connection, "%d %s %s %d %s", REQ_KEY, mesh->self->name, to->name, REQ_SPTPS, buf);
}
-
- inpkt = outpkt;
}
- /* Add sequence number */
-
- inpkt->seqno = htonl(++(n->sent_seqno));
- inpkt->len += sizeof inpkt->seqno;
+ /* Otherwise, send the packet via UDP */
- /* Encrypt the packet */
+ const sockaddr_t *sa;
+ int sock;
- if(cipher_active(&n->outcipher)) {
- outpkt = pkt[nextpkt++];
- outlen = MAXSIZE;
+ if(to->status.broadcast)
+ choose_broadcast_address(mesh, to, &sa, &sock);
+ else
+ choose_udp_address(mesh, to, &sa, &sock);
- 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;
+ 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)
+ to->maxmtu = len - 1;
+ if(to->mtu >= len)
+ to->mtu = len - 1;
+ } else {
+ logger(mesh, MESHLINK_WARNING, "Error sending UDP SPTPS packet to %s (%s): %s", to->name, to->hostname, sockstrerror(sockerrno));
+ return false;
}
-
- 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);
- }
+ return true;
+}
- /* Determine which socket we have to use */
+bool receive_sptps_record(void *handle, uint8_t type, const void *data, uint16_t len) {
+ node_t *from = handle;
+ meshlink_handle_t *mesh = from->mesh;
- 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;
- }
+ if(type == SPTPS_HANDSHAKE) {
+ if(!from->status.validkey) {
+ from->status.validkey = true;
+ from->status.waitingforkey = false;
+ logger(mesh, MESHLINK_INFO, "SPTPS key exchange with %s (%s) succesful", from->name, from->hostname);
}
+ return true;
}
- /* Send the packet */
-
- struct sockaddr *sa;
- socklen_t sl;
- int sock;
+ if(len > MTU) {
+ logger(mesh, MESHLINK_ERROR, "Packet from %s (%s) larger than maximum supported size (%d > %d)", from->name, from->hostname, len, MTU);
+ return false;
+ }
- /* Overloaded use of priority field: -1 means local broadcast */
+ vpn_packet_t inpkt;
- 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;
+ if(type == PKT_PROBE) {
+ inpkt.len = len;
+ inpkt.probe = true;
+ memcpy(inpkt.data, data, len);
+ mtu_probe_h(mesh, from, &inpkt, len);
+ return true;
} else {
- if(origpriority == -1)
- origpriority = 0;
-
- sa = &(n->address.sa);
- sl = SALEN(n->address.sa);
- sock = n->sock;
+ inpkt.probe = false;
}
-#if defined(SOL_IP) && defined(IP_TOS)
- if(priorityinheritance && origpriority != priority
- && 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[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));
+ if(type & ~(PKT_COMPRESSED)) {
+ logger(mesh, MESHLINK_ERROR, "Unexpected SPTPS record type %d len %d from %s (%s)", type, len, from->name, from->hostname);
+ return false;
}
-#endif
- 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));
+ if(type & PKT_COMPRESSED) {
+ uint16_t ulen = uncompress_packet(inpkt.data, (const uint8_t *)data, len, from->incompression);
+ if(ulen < 0) {
+ return false;
+ } else {
+ inpkt.len = ulen;
+ }
+ if(inpkt.len > MAXSIZE)
+ abort();
+ } else {
+ memcpy(inpkt.data, data, len);
+ inpkt.len = len;
}
-end:
- origpkt->len = origlen;
+ 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;
}
- ifdebug(TRAFFIC) logger(LOG_ERR, "Sending packet of %d bytes to %s (%s)",
+ logger(mesh, MESHLINK_ERROR, "Sending packet of %d bytes to %s (%s)",
packet->len, n->name, n->hostname);
if(!n->status.reachable) {
- ifdebug(TRAFFIC) logger(LOG_INFO, "Node %s (%s) is not reachable",
+ logger(mesh, MESHLINK_INFO, "Node %s (%s) is not reachable",
n->name, n->hostname);
return;
}
n->out_packets++;
n->out_bytes += packet->len;
- via = (packet->priority == -1 || n->via == myself) ? n->nexthop : n->via;
-
- if(via != n)
- ifdebug(TRAFFIC) logger(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);
+ send_sptps_packet(mesh, n, packet);
+ return;
}
/* Broadcast a packet using the minimum spanning tree */
-void broadcast_packet(const node_t *from, vpn_packet_t *packet) {
- splay_node_t *node;
- connection_t *c;
+void broadcast_packet(meshlink_handle_t *mesh, const node_t *from, vpn_packet_t *packet) {
+ // Always give ourself a copy of the packet.
+ if(from != mesh->self)
+ send_packet(mesh, mesh->self, packet);
- ifdebug(TRAFFIC) logger(LOG_INFO, "Broadcasting packet of %d bytes from %s (%s)",
+ logger(mesh, MESHLINK_INFO, "Broadcasting packet of %d bytes from %s (%s)",
packet->len, from->name, from->hostname);
- 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)
- return;
- }
-
- for(node = connection_tree->head; node; node = node->next) {
- c = node->data;
-
+ for list_each(connection_t, c, mesh->connections)
if(c->status.active && c->status.mst && c != from->nexthop->connection)
- send_packet(c->node, packet);
- }
+ send_packet(mesh, c->node, packet);
}
-static node_t *try_harder(const sockaddr_t *from, const vpn_packet_t *pkt) {
- splay_node_t *node;
- edge_t *e;
+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(node = edge_weight_tree->head; node; node = node->next) {
- e = node->data;
-
- if(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(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;
}
if(hard)
- last_hard_try = now;
+ last_hard_try = mesh->loop.now.tv_sec;
- last_hard_try = now;
+ last_hard_try = mesh->loop.now.tv_sec;
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) {
+ meshlink_handle_t *mesh = loop->data;
+ listen_socket_t *ls = data;
vpn_packet_t pkt;
char *hostname;
- sockaddr_t from;
+ sockaddr_t from = {{0}};
socklen_t fromlen = sizeof from;
node_t *n;
int len;
- len = recvfrom(sock, (char *) &pkt.seqno, MAXSIZE, 0, &from.sa, &fromlen);
+ len = recvfrom(ls->udp.fd, pkt.data, MAXSIZE, 0, &from.sa, &fromlen);
if(len <= 0 || len > MAXSIZE) {
if(!sockwouldblock(sockerrno))
- logger(LOG_ERR, "Receiving packet failed: %s", sockstrerror(sockerrno));
+ logger(mesh, MESHLINK_ERROR, "Receiving packet failed: %s", sockstrerror(sockerrno));
return;
}
pkt.len = len;
- sockaddrunmap(&from); /* Some braindead IPv6 implementations do stupid things. */
+ 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);
+ n = try_harder(mesh, &from, &pkt);
if(n)
- update_node_udp(n, &from);
- else ifdebug(PROTOCOL) {
+ update_node_udp(mesh, n, &from);
+ else if(mesh->log_level >= MESHLINK_WARNING) {
hostname = sockaddr2hostname(&from);
- logger(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;
}
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;
+ }
+ n->sock = ls - mesh->listen_socket;
- packet.priority = 0;
-
- if(devops.read(&packet)) {
- myself->in_packets++;
- myself->in_bytes += packet.len;
- route(myself, &packet);
- }
+ receive_udppacket(mesh, n, &pkt);
}