5 * Copyright (C) 2007-2009 Intel Corporation. All rights reserved.
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
30 #include <arpa/inet.h>
31 #include <netinet/in.h>
33 #define CONNMAN_API_SUBJECT_TO_CHANGE
34 #include <connman/plugin.h>
35 #include <connman/resolver.h>
36 #include <connman/notifier.h>
37 #include <connman/log.h>
41 #if __BYTE_ORDER == __LITTLE_ENDIAN
56 } __attribute__ ((packed));
57 #elif __BYTE_ORDER == __BIG_ENDIAN
72 } __attribute__ ((packed));
74 #error "Unknown byte order"
87 struct sockaddr_in sin;
99 static GSList *server_list = NULL;
100 static GSList *request_list = NULL;
101 static guint16 request_id = 0x0000;
103 static GIOChannel *listener_channel = NULL;
104 static guint listener_watch = 0;
106 static struct request_data *find_request(guint16 id)
110 for (list = request_list; list; list = list->next) {
111 struct request_data *req = list->data;
113 if (req->dstid == id || req->altid == id)
120 static struct server_data *find_server(const char *interface,
121 const char *domain, const char *server)
125 DBG("interface %s server %s", interface, server);
127 for (list = server_list; list; list = list->next) {
128 struct server_data *data = list->data;
130 if (data->interface == NULL || data->server == NULL)
133 if (g_str_equal(data->interface, interface) == TRUE &&
134 g_str_equal(data->server, server) == TRUE) {
135 if (domain == NULL) {
136 if (data->domain == NULL)
141 if (g_str_equal(data->domain, domain) == TRUE)
149 static gboolean server_event(GIOChannel *channel, GIOCondition condition,
152 struct server_data *data = user_data;
153 struct request_data *req;
154 unsigned char buf[4096];
155 struct domain_hdr *hdr = (void *) &buf;
158 if (condition & (G_IO_NVAL | G_IO_ERR | G_IO_HUP)) {
159 connman_error("Error with server channel");
164 sk = g_io_channel_unix_get_fd(channel);
166 len = recv(sk, buf, sizeof(buf), 0);
170 DBG("Received %d bytes (id 0x%04x)", len, buf[0] | buf[1] << 8);
172 req = find_request(buf[0] | buf[1] << 8);
176 DBG("id 0x%04x rcode %d", hdr->id, hdr->rcode);
178 buf[0] = req->srcid & 0xff;
179 buf[1] = req->srcid >> 8;
183 if (hdr->rcode == 0 || req->resp == NULL) {
187 req->resp = g_try_malloc(len);
188 if (req->resp == NULL)
191 memcpy(req->resp, buf, len);
195 if (hdr->rcode > 0 && req->numresp < req->numserv)
198 if (req->timeout > 0)
199 g_source_remove(req->timeout);
201 request_list = g_slist_remove(request_list, req);
203 sk = g_io_channel_unix_get_fd(listener_channel);
205 err = sendto(sk, req->resp, req->resplen, 0,
206 (struct sockaddr *) &req->sin, req->len);
214 static struct server_data *create_server(const char *interface,
215 const char *domain, const char *server)
217 struct server_data *data;
218 struct sockaddr_in sin;
221 DBG("interface %s server %s", interface, server);
223 sk = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
225 connman_error("Failed to create server %s socket", server);
229 if (setsockopt(sk, SOL_SOCKET, SO_BINDTODEVICE,
230 interface, strlen(interface) + 1) < 0) {
231 connman_error("Failed to bind server %s to interface %s",
237 memset(&sin, 0, sizeof(sin));
238 sin.sin_family = AF_INET;
239 sin.sin_port = htons(53);
240 sin.sin_addr.s_addr = inet_addr(server);
242 if (connect(sk, (struct sockaddr *) &sin, sizeof(sin)) < 0) {
243 connman_error("Failed to connect server %s", server);
248 data = g_try_new0(struct server_data, 1);
250 connman_error("Failed to allocate server %s data", server);
255 data->channel = g_io_channel_unix_new(sk);
256 if (data->channel == NULL) {
257 connman_error("Failed to create server %s channel", server);
263 g_io_channel_set_close_on_unref(data->channel, TRUE);
265 data->watch = g_io_add_watch(data->channel, G_IO_IN,
268 data->interface = g_strdup(interface);
269 data->domain = g_strdup(domain);
270 data->server = g_strdup(server);
272 /* Enable new servers by default */
273 data->enabled = TRUE;
275 connman_info("Adding DNS server %s", data->server);
280 static void destroy_server(struct server_data *data)
282 DBG("interface %s server %s", data->interface, data->server);
285 g_source_remove(data->watch);
287 g_io_channel_unref(data->channel);
289 connman_info("Removing DNS server %s", data->server);
291 g_free(data->server);
292 g_free(data->domain);
293 g_free(data->interface);
297 static int dnsproxy_append(const char *interface, const char *domain,
300 struct server_data *data;
302 DBG("interface %s server %s", interface, server);
304 if (g_str_equal(server, "127.0.0.1") == TRUE)
307 data = create_server(interface, domain, server);
311 server_list = g_slist_append(server_list, data);
316 static int dnsproxy_remove(const char *interface, const char *domain,
319 struct server_data *data;
321 DBG("interface %s server %s", interface, server);
323 if (g_str_equal(server, "127.0.0.1") == TRUE)
326 data = find_server(interface, domain, server);
330 server_list = g_slist_remove(server_list, data);
332 destroy_server(data);
337 static struct connman_resolver dnsproxy_resolver = {
339 .priority = CONNMAN_RESOLVER_PRIORITY_HIGH,
340 .append = dnsproxy_append,
341 .remove = dnsproxy_remove,
344 static void dnsproxy_offline_mode(connman_bool_t enabled)
348 DBG("enabled %d", enabled);
350 for (list = server_list; list; list = list->next) {
351 struct server_data *data = list->data;
353 if (enabled == FALSE) {
354 connman_info("Enabling DNS server %s", data->server);
355 data->enabled = TRUE;
357 connman_info("Disabling DNS server %s", data->server);
358 data->enabled = FALSE;
363 static void dnsproxy_default_changed(struct connman_service *service)
368 DBG("service %p", service);
370 if (service == NULL) {
371 /* When no services are active, then disable DNS proxying */
372 dnsproxy_offline_mode(TRUE);
376 interface = connman_service_get_interface(service);
377 if (interface == NULL)
380 for (list = server_list; list; list = list->next) {
381 struct server_data *data = list->data;
383 if (g_strcmp0(data->interface, interface) == 0) {
384 connman_info("Enabling DNS server %s", data->server);
385 data->enabled = TRUE;
387 connman_info("Disabling DNS server %s", data->server);
388 data->enabled = FALSE;
395 static struct connman_notifier dnsproxy_notifier = {
397 .default_changed = dnsproxy_default_changed,
398 .offline_mode = dnsproxy_offline_mode,
401 static int parse_request(unsigned char *buf, int len,
402 char *name, unsigned int size)
404 struct domain_hdr *hdr = (void *) buf;
405 uint16_t qdcount = ntohs(hdr->qdcount);
406 uint16_t arcount = ntohs(hdr->arcount);
408 char *last_label = NULL;
410 unsigned int remain, used = 0;
415 DBG("id 0x%04x qr %d opcode %d qdcount %d arcount %d",
416 hdr->id, hdr->qr, hdr->opcode,
419 if (hdr->qr != 0 || qdcount != 1)
422 memset(name, 0, size);
432 last_label = (char *) (ptr + 1);
438 if (used + len + 1 > size)
441 strncat(name, (char *) (ptr + 1), len);
450 if (arcount && remain >= 9 && last_label[4] == 0 &&
451 last_label[5] == 0 && last_label[6] == 0x29) {
452 uint16_t edns0_bufsize;
454 edns0_bufsize = last_label[7] << 8 | last_label[8];
456 DBG("EDNS0 buffer size %u", edns0_bufsize);
458 /* This is an evil hack until full TCP support has been
461 * Somtimes the EDNS0 request gets send with a too-small
462 * buffer size. Since glibc doesn't seem to crash when it
463 * gets a response biffer then it requested, just bump
464 * the buffer size up to 4KiB.
466 if (edns0_bufsize < 0x1000) {
467 last_label[7] = 0x10;
468 last_label[8] = 0x00;
472 DBG("query %s (%d labels)", name, label_count);
477 static void send_response(int sk, unsigned char *buf, int len,
478 const struct sockaddr *to, socklen_t tolen)
480 struct domain_hdr *hdr = (void *) buf;
486 DBG("id 0x%04x qr %d opcode %d", hdr->id, hdr->qr, hdr->opcode);
495 err = sendto(sk, buf, len, 0, to, tolen);
498 static int append_query(unsigned char *buf, unsigned int size,
499 const char *query, const char *domain)
501 unsigned char *ptr = buf;
504 DBG("query %s domain %s", query, domain);
506 offset = (char *) query;
507 while (offset != NULL) {
510 tmp = strchr(offset, '.');
512 if (strlen(offset) == 0)
514 *ptr = strlen(offset);
515 memcpy(ptr + 1, offset, strlen(offset));
516 ptr += strlen(offset) + 1;
521 memcpy(ptr + 1, offset, tmp - offset);
522 ptr += tmp - offset + 1;
527 offset = (char *) domain;
528 while (offset != NULL) {
531 tmp = strchr(offset, '.');
533 if (strlen(offset) == 0)
535 *ptr = strlen(offset);
536 memcpy(ptr + 1, offset, strlen(offset));
537 ptr += strlen(offset) + 1;
542 memcpy(ptr + 1, offset, tmp - offset);
543 ptr += tmp - offset + 1;
553 static gboolean request_timeout(gpointer user_data)
555 struct request_data *req = user_data;
557 DBG("id 0x%04x", req->srcid);
559 request_list = g_slist_remove(request_list, req);
561 if (req->resplen > 0 && req->resp != NULL) {
564 sk = g_io_channel_unix_get_fd(listener_channel);
566 err = sendto(sk, req->resp, req->resplen, 0,
567 (struct sockaddr *) &req->sin, req->len);
576 static gboolean listener_event(GIOChannel *channel, GIOCondition condition,
580 unsigned char buf[768];
582 struct request_data *req;
583 struct sockaddr_in sin;
584 socklen_t size = sizeof(sin);
587 if (condition & (G_IO_NVAL | G_IO_ERR | G_IO_HUP)) {
588 connman_error("Error with listener channel");
593 sk = g_io_channel_unix_get_fd(channel);
595 memset(&sin, 0, sizeof(sin));
596 len = recvfrom(sk, buf, sizeof(buf), 0,
597 (struct sockaddr *) &sin, &size);
601 DBG("Received %d bytes (id 0x%04x)", len, buf[0] | buf[1] << 8);
603 err = parse_request(buf, len, query, sizeof(query));
604 if (err < 0 || g_slist_length(server_list) == 0) {
605 send_response(sk, buf, len, (struct sockaddr *) &sin, size);
609 req = g_try_new0(struct request_data, 1);
613 memcpy(&req->sin, &sin, sizeof(sin));
617 if (request_id == 0x0000 || request_id == 0xffff)
620 req->srcid = buf[0] | (buf[1] << 8);
621 req->dstid = request_id;
622 req->altid = request_id + 1;
624 buf[0] = req->dstid & 0xff;
625 buf[1] = req->dstid >> 8;
627 request_list = g_slist_append(request_list, req);
630 req->timeout = g_timeout_add_seconds(5, request_timeout, req);
632 for (list = server_list; list; list = list->next) {
633 struct server_data *data = list->data;
635 DBG("server %s domain %s enabled %d",
636 data->server, data->domain, data->enabled);
638 if (data->enabled == FALSE)
641 sk = g_io_channel_unix_get_fd(data->channel);
643 err = send(sk, buf, len, 0);
647 if (data->domain != NULL) {
648 unsigned char alt[1024];
649 struct domain_hdr *hdr = (void *) &alt;
652 domlen = strlen(data->domain) + 1;
656 alt[0] = req->altid & 0xff;
657 alt[1] = req->altid >> 8;
659 memcpy(alt + 2, buf + 2, 10);
660 hdr->qdcount = htons(1);
662 altlen = append_query(alt + 12, sizeof(alt) - 12,
663 query, data->domain);
669 memcpy(alt + altlen, buf + altlen - domlen,
670 len - altlen + domlen);
672 err = send(sk, alt, altlen + 4, 0);
681 static int create_listener(void)
683 const char *ifname = "lo";
684 struct sockaddr_in sin;
689 sk = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
691 connman_error("Failed to create listener socket");
695 //setsockopt(sk, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
696 //setsockopt(sk, SOL_IP, IP_PKTINFO, &opt, sizeof(opt));
698 if (setsockopt(sk, SOL_SOCKET, SO_BINDTODEVICE,
699 ifname, strlen(ifname) + 1) < 0) {
700 connman_error("Failed to bind listener interface");
705 memset(&sin, 0, sizeof(sin));
706 sin.sin_family = AF_INET;
707 sin.sin_port = htons(53);
708 sin.sin_addr.s_addr = inet_addr("127.0.0.1");
709 //sin.sin_addr.s_addr = INADDR_ANY;
711 if (bind(sk, (struct sockaddr *) &sin, sizeof(sin)) < 0) {
712 connman_error("Failed to bind listener socket");
717 listener_channel = g_io_channel_unix_new(sk);
718 if (listener_channel == NULL) {
719 connman_error("Failed to create listener channel");
724 g_io_channel_set_close_on_unref(listener_channel, TRUE);
726 listener_watch = g_io_add_watch(listener_channel, G_IO_IN,
727 listener_event, NULL);
729 connman_resolver_append("lo", NULL, "127.0.0.1");
734 static void destroy_listener(void)
740 connman_resolver_remove_all("lo");
742 if (listener_watch > 0)
743 g_source_remove(listener_watch);
745 for (list = request_list; list; list = list->next) {
746 struct request_data *req = list->data;
748 DBG("Dropping request (id 0x%04x -> 0x%04x)",
749 req->srcid, req->dstid);
756 g_slist_free(request_list);
759 g_io_channel_unref(listener_channel);
762 static int dnsproxy_init(void)
766 err = create_listener();
770 err = connman_resolver_register(&dnsproxy_resolver);
774 err = connman_notifier_register(&dnsproxy_notifier);
781 connman_resolver_unregister(&dnsproxy_resolver);
789 static void dnsproxy_exit(void)
791 connman_notifier_unregister(&dnsproxy_notifier);
793 connman_resolver_unregister(&dnsproxy_resolver);
798 CONNMAN_PLUGIN_DEFINE(dnsproxy, "DNS proxy resolver plugin", VERSION,
799 CONNMAN_PLUGIN_PRIORITY_DEFAULT, dnsproxy_init, dnsproxy_exit)