2 net_socket.c -- Handle various kinds of sockets.
3 Copyright (C) 2014-2017 Guus Sliepen <guus@meshlink.io>
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License along
16 with this program; if not, write to the Free Software Foundation, Inc.,
17 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
23 #include "connection.h"
26 #include "meshlink_internal.h"
34 /* Needed on Mac OS/X */
36 #define SOL_TCP IPPROTO_TCP
40 #define MSG_NOSIGNAL 0
43 static const int max_connection_burst = 100;
47 static void configure_tcp(connection_t *c) {
49 int flags = fcntl(c->socket, F_GETFL);
51 if(fcntl(c->socket, F_SETFL, flags | O_NONBLOCK) < 0) {
52 logger(c->mesh, MESHLINK_ERROR, "System call `%s' failed: %s", "fcntl", strerror(errno));
56 unsigned long arg = 1;
58 if(ioctlsocket(c->socket, FIONBIO, &arg) != 0) {
59 logger(c->mesh, MESHLINK_ERROR, "System call `%s' failed: %s", "ioctlsocket", sockstrerror(sockerrno));
64 #if defined(SOL_TCP) && defined(TCP_NODELAY)
66 setsockopt(c->socket, SOL_TCP, TCP_NODELAY, (void *)&nodelay, sizeof(nodelay));
69 #if defined(IP_TOS) && defined(IPTOS_LOWDELAY)
70 int lowdelay = IPTOS_LOWDELAY;
71 setsockopt(c->socket, IPPROTO_IP, IP_TOS, (void *)&lowdelay, sizeof(lowdelay));
75 static void retry_outgoing_handler(event_loop_t *loop, void *data) {
78 meshlink_handle_t *mesh = loop->data;
79 outgoing_t *outgoing = data;
80 setup_outgoing_connection(mesh, outgoing);
83 void retry_outgoing(meshlink_handle_t *mesh, outgoing_t *outgoing) {
84 if(!mesh->reachable && mesh->loop.now.tv_sec < mesh->last_unreachable + mesh->dev_class_traits[mesh->devclass].fast_retry_period) {
85 outgoing->timeout = 1;
87 outgoing->timeout += 5;
90 if(outgoing->timeout > mesh->maxtimeout) {
91 outgoing->timeout = mesh->maxtimeout;
94 timeout_add(&mesh->loop, &outgoing->ev, retry_outgoing_handler, outgoing, &(struct timespec) {
95 outgoing->timeout, prng(mesh, TIMER_FUDGE)
98 logger(mesh, MESHLINK_INFO, "Trying to re-establish outgoing connection in %d seconds", outgoing->timeout);
101 void finish_connecting(meshlink_handle_t *mesh, connection_t *c) {
102 logger(mesh, MESHLINK_INFO, "Connected to %s", c->name);
104 c->last_ping_time = mesh->loop.now.tv_sec;
105 c->status.connecting = false;
110 static void handle_meta_write(meshlink_handle_t *mesh, connection_t *c) {
111 if(c->outbuf.len <= c->outbuf.offset) {
115 ssize_t outlen = send(c->socket, c->outbuf.data + c->outbuf.offset, c->outbuf.len - c->outbuf.offset, MSG_NOSIGNAL);
118 if(!errno || errno == EPIPE) {
119 logger(mesh, MESHLINK_INFO, "Connection closed by %s", c->name);
120 } else if(sockwouldblock(sockerrno)) {
121 logger(mesh, MESHLINK_DEBUG, "Sending %lu bytes to %s would block", (unsigned long)(c->outbuf.len - c->outbuf.offset), c->name);
124 logger(mesh, MESHLINK_ERROR, "Could not send %lu bytes of data to %s: %s", (unsigned long)(c->outbuf.len - c->outbuf.offset), c->name, strerror(errno));
127 terminate_connection(mesh, c, c->status.active);
131 buffer_read(&c->outbuf, outlen);
134 io_set(&mesh->loop, &c->io, IO_READ);
138 static void handle_meta_io(event_loop_t *loop, void *data, int flags) {
139 meshlink_handle_t *mesh = loop->data;
140 connection_t *c = data;
142 if(c->status.connecting) {
143 c->status.connecting = false;
146 socklen_t len = sizeof(result);
147 getsockopt(c->socket, SOL_SOCKET, SO_ERROR, (void *)&result, &len);
150 finish_connecting(mesh, c);
152 logger(mesh, MESHLINK_DEBUG, "Error while connecting to %s: %s", c->name, sockstrerror(result));
153 terminate_connection(mesh, c, false);
158 if(flags & IO_WRITE) {
159 handle_meta_write(mesh, c);
161 handle_meta_connection_data(mesh, c);
165 // Find edges pointing to this node, and use them to build a list of unique, known addresses.
166 static struct addrinfo *get_known_addresses(node_t *n) {
167 struct addrinfo *ai = NULL;
169 for splay_each(edge_t, e, n->edge_tree) {
176 for(struct addrinfo *aip = ai; aip; aip = aip->ai_next) {
177 if(!sockaddrcmp(&e->reverse->address, (sockaddr_t *)aip->ai_addr)) {
187 // Create a new struct addrinfo, and put it at the head of the list.
188 struct addrinfo *nai = xzalloc(sizeof(*nai) + SALEN(e->reverse->address.sa));
192 ai->ai_family = e->reverse->address.sa.sa_family;
193 ai->ai_socktype = SOCK_STREAM;
194 ai->ai_protocol = IPPROTO_TCP;
195 ai->ai_addrlen = SALEN(e->reverse->address.sa);
196 ai->ai_addr = (struct sockaddr *)(nai + 1);
197 memcpy(ai->ai_addr, &e->reverse->address, ai->ai_addrlen);
203 // Build a list of recently seen addresses.
204 static struct addrinfo *get_recent_addresses(node_t *n) {
205 struct addrinfo *ai = NULL;
206 struct addrinfo *aip;
208 for(int i = 0; i < 5; i++) {
209 if(!n->recent[i].sa.sa_family) {
213 // Create a new struct addrinfo, and put it at the end of the list.
214 struct addrinfo *nai = xzalloc(sizeof(*nai) + SALEN(n->recent[i].sa));
224 nai->ai_family = n->recent[i].sa.sa_family;
225 nai->ai_socktype = SOCK_STREAM;
226 nai->ai_protocol = IPPROTO_TCP;
227 nai->ai_addrlen = SALEN(n->recent[i].sa);
228 nai->ai_addr = (struct sockaddr *)(nai + 1);
229 memcpy(nai->ai_addr, &n->recent[i], nai->ai_addrlen);
235 // Free struct addrinfo list from get_known_addresses().
236 static void free_known_addresses(struct addrinfo *ai) {
237 for(struct addrinfo *aip = ai, *next; aip; aip = next) {
243 static struct addrinfo *get_canonical_address(node_t *n) {
244 if(!n->canonical_address) {
248 char *address = xstrdup(n->canonical_address);
249 char *port = strchr(address, ' ');
258 struct addrinfo *ai = str2addrinfo(address, port, SOCK_STREAM);
264 static bool get_next_outgoing_address(meshlink_handle_t *mesh, outgoing_t *outgoing) {
269 if(outgoing->state == OUTGOING_START) {
271 outgoing->state = OUTGOING_CANONICAL;
274 if(outgoing->state == OUTGOING_CANONICAL) {
276 outgoing->ai = get_canonical_address(outgoing->node);
277 outgoing->aip = outgoing->ai;
279 outgoing->aip = outgoing->aip->ai_next;
286 freeaddrinfo(outgoing->ai);
288 outgoing->aip = NULL;
289 outgoing->state = OUTGOING_RECENT;
292 if(outgoing->state == OUTGOING_RECENT) {
294 outgoing->ai = get_recent_addresses(outgoing->node);
295 outgoing->aip = outgoing->ai;
297 outgoing->aip = outgoing->aip->ai_next;
304 free_known_addresses(outgoing->ai);
306 outgoing->aip = NULL;
307 outgoing->state = OUTGOING_KNOWN;
310 if(outgoing->state == OUTGOING_KNOWN) {
312 outgoing->ai = get_known_addresses(outgoing->node);
313 outgoing->aip = outgoing->ai;
315 outgoing->aip = outgoing->aip->ai_next;
322 free_known_addresses(outgoing->ai);
324 outgoing->aip = NULL;
325 outgoing->state = OUTGOING_END;
329 outgoing->state = OUTGOING_NO_KNOWN_ADDRESSES;
335 void do_outgoing_connection(meshlink_handle_t *mesh, outgoing_t *outgoing) {
338 if(!get_next_outgoing_address(mesh, outgoing)) {
339 if(outgoing->state == OUTGOING_NO_KNOWN_ADDRESSES) {
340 logger(mesh, MESHLINK_ERROR, "No known addresses for %s", outgoing->node->name);
342 logger(mesh, MESHLINK_ERROR, "Could not set up a meta connection to %s", outgoing->node->name);
343 retry_outgoing(mesh, outgoing);
349 connection_t *c = new_connection();
350 c->outgoing = outgoing;
352 memcpy(&c->address, outgoing->aip->ai_addr, outgoing->aip->ai_addrlen);
354 if(mesh->log_level <= MESHLINK_INFO) {
355 char *hostname = sockaddr2hostname(&c->address);
356 logger(mesh, MESHLINK_INFO, "Trying to connect to %s at %s", outgoing->node->name, hostname);
360 c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
362 if(c->socket == -1) {
363 if(mesh->log_level <= MESHLINK_ERROR) {
364 char *hostname = sockaddr2hostname(&c->address);
365 logger(mesh, MESHLINK_ERROR, "Creating socket for %s at %s failed: %s", c->name, hostname, sockstrerror(sockerrno));
376 fcntl(c->socket, F_SETFD, FD_CLOEXEC);
379 #if defined(IPV6_V6ONLY)
381 if(c->address.sa.sa_family == AF_INET6) {
382 static const int option = 1;
383 setsockopt(c->socket, IPPROTO_IPV6, IPV6_V6ONLY, (void *)&option, sizeof(option));
390 int result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
392 if(result == -1 && !sockinprogress(sockerrno)) {
393 if(mesh->log_level <= MESHLINK_ERROR) {
394 char *hostname = sockaddr2hostname(&c->address);
395 logger(mesh, MESHLINK_ERROR, "Could not connect to %s: %s", outgoing->node->name, sockstrerror(sockerrno));
403 /* Now that there is a working socket, fill in the rest and register this connection. */
405 c->status.connecting = true;
406 c->status.initiator = true;
407 c->name = xstrdup(outgoing->node->name);
408 c->last_ping_time = mesh->loop.now.tv_sec;
410 connection_add(mesh, c);
412 io_add(&mesh->loop, &c->io, handle_meta_io, c, c->socket, IO_READ | IO_WRITE);
415 void reset_outgoing(outgoing_t *outgoing) {
417 if(outgoing->state == OUTGOING_RECENT || outgoing->state == OUTGOING_KNOWN) {
418 free_known_addresses(outgoing->ai);
420 freeaddrinfo(outgoing->ai);
425 outgoing->aip = NULL;
426 outgoing->state = OUTGOING_START;
429 void setup_outgoing_connection(meshlink_handle_t *mesh, outgoing_t *outgoing) {
430 timeout_del(&mesh->loop, &outgoing->ev);
432 if(outgoing->node->connection) {
433 logger(mesh, MESHLINK_INFO, "Already connected to %s", outgoing->node->name);
435 outgoing->node->connection->outgoing = outgoing;
439 reset_outgoing(outgoing);
441 if(outgoing->node->status.blacklisted) {
445 if(mesh->connection_try_cb) {
446 mesh->connection_try_cb(mesh, (meshlink_node_t *)outgoing->node);
449 do_outgoing_connection(mesh, outgoing);
452 /// Delayed close of a filedescriptor.
453 static void tarpit(meshlink_handle_t *mesh, int fd) {
458 if(mesh->pits[mesh->next_pit]) {
459 closesocket(mesh->pits[mesh->next_pit]);
462 mesh->pits[mesh->next_pit++] = fd;
464 if(mesh->next_pit >= (int)(sizeof mesh->pits / sizeof mesh->pits[0])) {
470 accept a new tcp connect and create a
473 void handle_new_meta_connection(event_loop_t *loop, void *data, int flags) {
475 meshlink_handle_t *mesh = loop->data;
476 listen_socket_t *l = data;
480 socklen_t len = sizeof(sa);
482 memset(&sa, 0, sizeof(sa));
484 fd = accept(l->tcp.fd, &sa.sa, &len);
487 if(errno == EINVAL) { // TODO: check if Windows agrees
488 event_loop_stop(loop);
492 logger(mesh, MESHLINK_ERROR, "Accepting a new connection failed: %s", sockstrerror(sockerrno));
498 /* Rate limit incoming connections to max_connection_burst/second. */
500 if(mesh->loop.now.tv_sec != mesh->connection_burst_time) {
501 mesh->connection_burst_time = mesh->loop.now.tv_sec;
502 mesh->connection_burst = 0;
505 if(mesh->connection_burst >= max_connection_burst) {
510 mesh->connection_burst++;
512 // Accept the new connection
514 c = new_connection();
515 c->name = xstrdup("<unknown>");
519 c->last_ping_time = mesh->loop.now.tv_sec;
521 char *hostname = sockaddr2hostname(&sa);
522 logger(mesh, MESHLINK_INFO, "Connection from %s", hostname);
525 io_add(&mesh->loop, &c->io, handle_meta_io, c, c->socket, IO_READ);
529 connection_add(mesh, c);
531 c->allow_request = ID;
535 static void free_outgoing(outgoing_t *outgoing) {
536 meshlink_handle_t *mesh = outgoing->node->mesh;
538 timeout_del(&mesh->loop, &outgoing->ev);
541 if(outgoing->state == OUTGOING_RECENT || outgoing->state == OUTGOING_KNOWN) {
542 free_known_addresses(outgoing->ai);
544 freeaddrinfo(outgoing->ai);
551 void init_outgoings(meshlink_handle_t *mesh) {
552 mesh->outgoings = list_alloc((list_action_t)free_outgoing);
555 void exit_outgoings(meshlink_handle_t *mesh) {
556 if(mesh->outgoings) {
557 list_delete_list(mesh->outgoings);
558 mesh->outgoings = NULL;