2 This file is part of GNUnet.
3 (C) 2009 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 3, or (at your
8 option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
22 * @file vpn/gnunet-service-dns.c
23 * @author Philipp Toelke
26 #include "gnunet_getopt_lib.h"
27 #include "gnunet_service_lib.h"
28 #include "gnunet_network_lib.h"
29 #include "gnunet_os_lib.h"
30 #include "gnunet-service-dns-p.h"
31 #include "gnunet_protocols.h"
32 #include "gnunet-vpn-packet.h"
33 #include "gnunet-vpn-pretty-print.h"
34 #include "gnunet_container_lib.h"
35 #include "gnunet-dns-parser.h"
36 #include "gnunet_dht_service.h"
37 #include "gnunet_block_lib.h"
38 #include "gnunet_block_dns.h"
41 struct GNUNET_SCHEDULER_Handle *sched;
43 struct GNUNET_NETWORK_Handle *dnsout;
45 struct GNUNET_DHT_Handle *dht;
47 unsigned short dnsoutport;
49 struct answer_packet_list *head;
50 struct answer_packet_list *tail;
52 static struct dns_cls mycls;
54 struct dns_query_id_state {
56 struct GNUNET_SERVER_Client* client;
58 unsigned remote_ip:32;
59 unsigned local_port:16;
61 static struct dns_query_id_state query_states[65536]; /* This is < 1.5MiB */
63 void hijack(unsigned short port) {
66 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Hijacking, port is %d\n", port);
67 snprintf(port_s, 6, "%d", port);
68 GNUNET_OS_start_process(NULL, NULL, "gnunet-helper-hijack-dns", "gnunet-hijack-dns", port_s, NULL);
71 void unhijack(unsigned short port) {
74 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "unHijacking, port is %d\n", port);
75 snprintf(port_s, 6, "%d", port);
76 GNUNET_OS_start_process(NULL, NULL, "gnunet-helper-hijack-dns", "gnunet-hijack-dns", "-d", port_s, NULL);
79 size_t send_answer(void* cls, size_t size, void* buf);
81 struct receive_dht_cls {
83 struct GNUNET_DHT_GetHandle* handle;
86 void receive_dht(void *cls,
87 struct GNUNET_TIME_Absolute exp,
88 const GNUNET_HashCode *key,
89 const struct GNUNET_PeerIdentity *const *get_path,
90 const struct GNUNET_PeerIdentity *const *put_path,
91 enum GNUNET_BLOCK_Type type,
95 unsigned short id = ((struct receive_dht_cls*)cls)->id;
96 struct GNUNET_DHT_GetHandle* handle = ((struct receive_dht_cls*)cls)->handle;
99 GNUNET_assert(type == GNUNET_BLOCK_TYPE_DNS);
101 if (query_states[id].valid != GNUNET_YES) return;
102 query_states[id].valid = GNUNET_NO;
104 const struct GNUNET_DNS_Record* rec = data;
105 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Got block of size %d, peer: %08x, desc: %08x\n", size, *((unsigned int*)&rec->peer), *((unsigned int*)&rec->service_descriptor));
107 size_t len = sizeof(struct answer_packet) + size - 1; /* 1 for the unsigned char data[1]; */
108 struct answer_packet_list* answer = GNUNET_malloc(len + 2*sizeof(struct answer_packet_list*));
109 answer->pkt.hdr.type = htons(GNUNET_MESSAGE_TYPE_LOCAL_RESPONSE_DNS);
110 answer->pkt.hdr.size = htons(len);
111 answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_SERVICE;
113 answer->pkt.from = query_states[id].remote_ip;
115 answer->pkt.to = query_states[id].local_ip;
116 answer->pkt.dst_port = query_states[id].local_port;
120 memcpy(answer->pkt.data, data, size);
122 GNUNET_CONTAINER_DLL_insert_after(mycls.head, mycls.tail, mycls.tail, answer);
124 GNUNET_SERVER_notify_transmit_ready(query_states[id].client,
126 GNUNET_TIME_UNIT_FOREVER_REL,
128 query_states[id].client);
130 GNUNET_DHT_get_stop(handle);
134 * This receives the dns-payload from the daemon-vpn and sends it on over the udp-socket
136 void receive_query(void *cls, struct GNUNET_SERVER_Client *client, const struct GNUNET_MessageHeader *message)
138 struct query_packet* pkt = (struct query_packet*)message;
139 struct dns_pkt* dns = (struct dns_pkt*)pkt->data;
140 struct dns_pkt_parsed* pdns = parse_dns_packet(dns);
142 query_states[dns->s.id].valid = GNUNET_YES;
143 query_states[dns->s.id].client = client;
144 query_states[dns->s.id].local_ip = pkt->orig_from;
145 query_states[dns->s.id].local_port = pkt->src_port;
146 query_states[dns->s.id].remote_ip = pkt->orig_to;
148 if (pdns->queries[0]->namelen > 9 &&
149 0 == strncmp(pdns->queries[0]->name+(pdns->queries[0]->namelen - 9), ".gnunet.", 9)) {
151 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Query for .gnunet!\n");
153 GNUNET_CRYPTO_hash(pdns->queries[0]->name, pdns->queries[0]->namelen, &key);
155 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Getting with key %08x, len is %d\n", *((unsigned int*)&key), pdns->queries[0]->namelen);
157 struct receive_dht_cls* cls = GNUNET_malloc(sizeof(struct receive_dht_cls));
160 cls->handle = GNUNET_DHT_get_start(mycls.dht,
161 GNUNET_TIME_UNIT_MINUTES,
162 GNUNET_BLOCK_TYPE_DNS,
175 /* The query should be sent to the network */
178 struct sockaddr_in dest;
179 memset(&dest, 0, sizeof dest);
180 dest.sin_port = htons(53);
181 dest.sin_addr.s_addr = pkt->orig_to;
183 /* int r = */ GNUNET_NETWORK_socket_sendto(mycls.dnsout, dns, ntohs(pkt->hdr.size) - sizeof(struct query_packet) + 1, (struct sockaddr*) &dest, sizeof dest);
186 GNUNET_SERVER_receive_done(client, GNUNET_OK);
189 size_t send_answer(void* cls, size_t size, void* buf) {
190 struct answer_packet_list* query = mycls.head;
191 size_t len = ntohs(query->pkt.hdr.size);
193 GNUNET_assert(len <= size);
195 memcpy(buf, &query->pkt.hdr, len);
197 GNUNET_CONTAINER_DLL_remove (mycls.head, mycls.tail, query);
201 if (mycls.head != NULL) {
202 GNUNET_SERVER_notify_transmit_ready(cls, ntohs(mycls.head->pkt.hdr.size), GNUNET_TIME_UNIT_FOREVER_REL, &send_answer, cls);
208 static void read_response (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) {
209 unsigned char buf[65536];
210 struct dns_pkt* dns = (struct dns_pkt*)buf;
212 if (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)
215 struct sockaddr_in addr;
216 memset(&addr, 0, sizeof addr);
217 unsigned int addrlen = sizeof addr;
220 r = GNUNET_NETWORK_socket_recvfrom(mycls.dnsout, buf, 65536, (struct sockaddr*)&addr, &addrlen);
222 /* if (r < 0) TODO */
224 if (query_states[dns->s.id].valid == GNUNET_YES) {
225 query_states[dns->s.id].valid = GNUNET_NO;
227 size_t len = sizeof(struct answer_packet) + r - 1; /* 1 for the unsigned char data[1]; */
228 struct answer_packet_list* answer = GNUNET_malloc(len + 2*sizeof(struct answer_packet_list*));
229 answer->pkt.hdr.type = htons(GNUNET_MESSAGE_TYPE_LOCAL_RESPONSE_DNS);
230 answer->pkt.hdr.size = htons(len);
231 answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_IP;
232 answer->pkt.from = addr.sin_addr.s_addr;
233 answer->pkt.to = query_states[dns->s.id].local_ip;
234 answer->pkt.dst_port = query_states[dns->s.id].local_port;
235 memcpy(answer->pkt.data, buf, r);
237 GNUNET_CONTAINER_DLL_insert_after(mycls.head, mycls.tail, mycls.tail, answer);
239 /* struct GNUNET_CONNECTION_TransmitHandle* th = */ GNUNET_SERVER_notify_transmit_ready(query_states[dns->s.id].client, len, GNUNET_TIME_UNIT_FOREVER_REL, &send_answer, query_states[dns->s.id].client);
242 GNUNET_SCHEDULER_add_read_net(mycls.sched, GNUNET_TIME_UNIT_FOREVER_REL, mycls.dnsout, &read_response, NULL);
247 * Task run during shutdown.
253 cleanup_task (void *cls,
254 const struct GNUNET_SCHEDULER_TaskContext *tc)
256 unhijack(mycls.dnsoutport);
257 GNUNET_DHT_disconnect(mycls.dht);
261 publish_name (void *cls,
262 const struct GNUNET_SCHEDULER_TaskContext *tc)
264 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
267 char* name = "philipptoelke.gnunet.";
268 size_t size = sizeof(struct GNUNET_DNS_Record) + strlen(name);
269 struct GNUNET_DNS_Record *data = alloca(size);
270 memset(data, 0, size);
271 memcpy(data->name, name, strlen(name) + 1);
272 data->namelen = strlen(name) + 1;
273 *((unsigned int*)&data->service_descriptor) = 0x11223344;
274 *((unsigned int*)&data->peer) = 0x55667788;
277 GNUNET_CRYPTO_hash(name, strlen(name)+1, &key);
278 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Putting with key %08x, len is %d\n", *((unsigned int*)&key), strlen(name));
280 GNUNET_DHT_put(mycls.dht,
283 GNUNET_BLOCK_TYPE_DNS,
286 GNUNET_TIME_relative_to_absolute(GNUNET_TIME_UNIT_HOURS),
287 GNUNET_TIME_UNIT_MINUTES,
291 GNUNET_SCHEDULER_add_delayed (mycls.sched, GNUNET_TIME_UNIT_HOURS, publish_name, NULL);
296 * @param sched scheduler to use
297 * @param server the initialized server
298 * @param cfg configuration to use
302 struct GNUNET_SCHEDULER_Handle *sched,
303 struct GNUNET_SERVER_Handle *server,
304 const struct GNUNET_CONFIGURATION_Handle *cfg)
306 static const struct GNUNET_SERVER_MessageHandler handlers[] = {
307 /* callback, cls, type, size */
308 {&receive_query, NULL, GNUNET_MESSAGE_TYPE_LOCAL_QUERY_DNS, 0},
314 for (i = 0; i < 65536; i++) {
315 query_states[i].valid = GNUNET_NO;
319 mycls.dht = GNUNET_DHT_connect(sched, cfg, 1024);
321 struct sockaddr_in addr;
324 mycls.dnsout = GNUNET_NETWORK_socket_create (AF_INET, SOCK_DGRAM, 0);
325 if (mycls.dnsout == NULL)
327 memset(&addr, 0, sizeof(struct sockaddr_in));
329 int err = GNUNET_NETWORK_socket_bind (mycls.dnsout,
330 (struct sockaddr*)&addr,
331 sizeof(struct sockaddr_in));
333 if (err != GNUNET_YES) {
334 GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "Could not bind a port, exiting\n");
337 socklen_t addrlen = sizeof(struct sockaddr_in);
338 err = getsockname(GNUNET_NETWORK_get_fd(mycls.dnsout),
339 (struct sockaddr*) &addr,
342 mycls.dnsoutport = htons(addr.sin_port);
344 hijack(htons(addr.sin_port));
346 GNUNET_SCHEDULER_add_now (mycls.sched, publish_name, NULL);
348 GNUNET_SCHEDULER_add_read_net(sched, GNUNET_TIME_UNIT_FOREVER_REL, mycls.dnsout, &read_response, NULL);
350 GNUNET_SERVER_add_handlers (server, handlers);
351 GNUNET_SCHEDULER_add_delayed (sched,
352 GNUNET_TIME_UNIT_FOREVER_REL,
358 * The main function for the dns service.
360 * @param argc number of arguments from the command line
361 * @param argv command line arguments
362 * @return 0 ok, 1 on error
365 main (int argc, char *const *argv)
368 GNUNET_SERVICE_run (argc,
371 GNUNET_SERVICE_OPTION_NONE,
372 &run, NULL)) ? 0 : 1;