2 dns.c -- hostname resolving functions
3 Copyright (C) 2019 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 <stdatomic.h>
30 typedef struct adns_item {
40 static void *adns_loop(void *data) {
41 meshlink_handle_t *mesh = data;
44 adns_item_t *item = meshlink_queue_pop_cond(&mesh->adns_queue, &mesh->adns_cond);
50 if(time(NULL) < item->deadline) {
51 logger(mesh, MESHLINK_DEBUG, "Resolving %s port %s", item->host, item->serv);
52 devtool_adns_resolve_probe();
53 int result = getaddrinfo(item->host, item->serv, NULL, &item->ai);
60 logger(mesh, MESHLINK_WARNING, "Deadline passed for DNS request %s port %s", item->host, item->serv);
62 item->err = ETIMEDOUT;
65 if(meshlink_queue_push(&mesh->adns_done_queue, item)) {
66 signal_trigger(&mesh->loop, &mesh->adns_signal);
77 static void adns_cb_handler(event_loop_t *loop, void *data) {
79 meshlink_handle_t *mesh = data;
81 for(adns_item_t *item; (item = meshlink_queue_pop(&mesh->adns_done_queue));) {
82 item->cb(mesh, item->host, item->serv, item->data, item->ai, item->err);
87 void init_adns(meshlink_handle_t *mesh) {
88 meshlink_queue_init(&mesh->adns_queue);
89 meshlink_queue_init(&mesh->adns_done_queue);
90 signal_add(&mesh->loop, &mesh->adns_signal, adns_cb_handler, mesh, 1);
91 pthread_create(&mesh->adns_thread, NULL, adns_loop, mesh);
94 void exit_adns(meshlink_handle_t *mesh) {
95 if(!mesh->adns_signal.cb) {
99 /* Drain the queue of any pending ADNS requests */
100 for(adns_item_t *item; (item = meshlink_queue_pop(&mesh->adns_queue));) {
106 /* Signal the ADNS thread to stop */
107 if(!meshlink_queue_push(&mesh->adns_queue, NULL)) {
111 assert(pthread_cond_signal(&mesh->adns_cond) == 0);
113 pthread_join(mesh->adns_thread, NULL);
114 meshlink_queue_exit(&mesh->adns_queue);
115 signal_del(&mesh->loop, &mesh->adns_signal);
118 void adns_queue(meshlink_handle_t *mesh, char *host, char *serv, adns_cb_t cb, void *data, int timeout) {
119 adns_item_t *item = xmalloc(sizeof(*item));
122 item->deadline = time(NULL) + timeout;
126 logger(mesh, MESHLINK_DEBUG, "Enqueueing DNS request for %s port %s", item->host, item->serv);
128 if(!meshlink_queue_push(&mesh->adns_queue, item)) {
132 assert(pthread_cond_signal(&mesh->adns_cond) == 0);
135 struct adns_blocking_info {
136 meshlink_handle_t *mesh;
137 pthread_mutex_t mutex;
146 static void *adns_blocking_handler(void *data) {
147 struct adns_blocking_info *info = data;
149 logger(info->mesh, MESHLINK_DEBUG, "Resolving %s port %s", info->host, info->serv);
150 devtool_adns_resolve_probe();
152 struct addrinfo hint = {
153 .ai_family = AF_UNSPEC,
154 .ai_socktype = info->socktype,
157 if(getaddrinfo(info->host, info->serv, &hint, &info->ai)) {
161 assert(pthread_mutex_lock(&info->mutex) == 0);
163 bool cleanup = info->done;
167 assert(pthread_cond_signal(&info->cond) == 0);
170 assert(pthread_mutex_unlock(&info->mutex) == 0);
181 struct addrinfo *adns_blocking_request(meshlink_handle_t *mesh, char *host, char *serv, int socktype, int timeout) {
182 struct adns_blocking_info *info = xzalloc(sizeof(*info));
187 info->socktype = socktype;
188 assert(pthread_mutex_init(&info->mutex, NULL) == 0);
189 assert(pthread_cond_init(&info->cond, NULL) == 0);
191 struct timespec deadline;
192 clock_gettime(CLOCK_REALTIME, &deadline);
193 deadline.tv_sec += timeout;
197 if(pthread_create(&thread, NULL, adns_blocking_handler, info)) {
203 assert(pthread_detach(thread) == 0);
206 assert(pthread_mutex_lock(&info->mutex) == 0);
207 assert(pthread_cond_timedwait(&info->cond, &info->mutex, &deadline) == 0);
209 struct addrinfo *result = NULL;
210 bool cleanup = info->done;
215 logger(mesh, MESHLINK_WARNING, "Deadline passed for DNS request %s port %s", host, serv);
219 assert(pthread_mutex_unlock(&info->mutex) == 0);