2 This file is part of GNUnet.
3 (C) 2010 Christian Grothoff
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-daemon-vpn.c
24 * @author Philipp Tölke
27 #include "gnunet_getopt_lib.h"
28 #include "gnunet_program_lib.h"
29 #include "gnunet_os_lib.h"
30 #include "gnunet-vpn-helper-p.h"
31 #include "gnunet-vpn-packet.h"
32 #include "gnunet-vpn-pretty-print.h"
33 #include "gnunet_common.h"
34 #include "gnunet_protocols.h"
35 #include "gnunet_server_lib.h"
36 #include "gnunet-service-dns-p.h"
37 #include "gnunet_client_lib.h"
38 #include "gnunet_container_lib.h"
39 #include "block_dns.h"
47 struct GNUNET_DISK_PipeHandle* helper_in; // From the helper
48 struct GNUNET_DISK_PipeHandle* helper_out; // To the helper
49 const struct GNUNET_DISK_FileHandle* fh_from_helper;
50 const struct GNUNET_DISK_FileHandle* fh_to_helper;
52 struct GNUNET_SERVER_MessageStreamTokenizer* mst;
54 struct GNUNET_SCHEDULER_Handle *sched;
56 struct GNUNET_CLIENT_Connection *dns_connection;
57 unsigned char restart_hijack;
61 const struct GNUNET_CONFIGURATION_Handle *cfg;
63 struct query_packet_list *head;
64 struct query_packet_list *tail;
66 struct answer_packet_list *answer_proc_head;
67 struct answer_packet_list *answer_proc_tail;
70 static struct vpn_cls mycls;
72 size_t send_query(void* cls, size_t size, void* buf);
74 static void cleanup(void* cls, const struct GNUNET_SCHEDULER_TaskContext* tskctx) {
75 GNUNET_assert (0 != (tskctx->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN));
76 PLIBC_KILL(mycls.helper_pid, SIGTERM);
77 GNUNET_OS_process_wait(mycls.helper_pid);
78 if (mycls.dns_connection != NULL)
80 GNUNET_CLIENT_disconnect (mycls.dns_connection, GNUNET_NO);
81 mycls.dns_connection = NULL;
85 static void helper_read(void* cls, const struct GNUNET_SCHEDULER_TaskContext* tsdkctx);
87 static void start_helper_and_schedule(void *cls,
88 const struct GNUNET_SCHEDULER_TaskContext *tc) {
90 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
93 mycls.helper_in = GNUNET_DISK_pipe (GNUNET_YES, GNUNET_YES, GNUNET_NO);
94 mycls.helper_out = GNUNET_DISK_pipe (GNUNET_YES, GNUNET_NO, GNUNET_YES);
96 if (mycls.helper_in == NULL || mycls.helper_out == NULL) return;
98 mycls.helper_pid = GNUNET_OS_start_process(mycls.helper_in, mycls.helper_out, "gnunet-helper-vpn", "gnunet-helper-vpn", NULL);
100 mycls.fh_from_helper = GNUNET_DISK_pipe_handle (mycls.helper_out, GNUNET_DISK_PIPE_END_READ);
101 mycls.fh_to_helper = GNUNET_DISK_pipe_handle (mycls.helper_in, GNUNET_DISK_PIPE_END_WRITE);
103 GNUNET_DISK_pipe_close_end(mycls.helper_out, GNUNET_DISK_PIPE_END_WRITE);
104 GNUNET_DISK_pipe_close_end(mycls.helper_in, GNUNET_DISK_PIPE_END_READ);
106 GNUNET_SCHEDULER_add_read_file (mycls.sched, GNUNET_TIME_UNIT_FOREVER_REL, mycls.fh_from_helper, &helper_read, NULL);
110 static void restart_helper(void* cls, const struct GNUNET_SCHEDULER_TaskContext* tskctx) {
112 PLIBC_KILL(mycls.helper_pid, SIGKILL);
113 GNUNET_OS_process_wait(mycls.helper_pid);
115 /* Tell the dns-service to rehijack the dns-port
116 * The routing-table gets flushed if an interface disappears.
118 mycls.restart_hijack = 1;
119 GNUNET_CLIENT_notify_transmit_ready(mycls.dns_connection, sizeof(struct GNUNET_MessageHeader), GNUNET_TIME_UNIT_FOREVER_REL, GNUNET_YES, &send_query, NULL);
121 GNUNET_DISK_pipe_close(mycls.helper_in);
122 GNUNET_DISK_pipe_close(mycls.helper_out);
124 // Restart the helper
125 GNUNET_SCHEDULER_add_delayed (mycls.sched, GNUNET_TIME_UNIT_SECONDS, start_helper_and_schedule, NULL);
129 static void helper_read(void* cls, const struct GNUNET_SCHEDULER_TaskContext* tsdkctx) {
132 if (tsdkctx->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)
135 int t = GNUNET_DISK_file_read(mycls.fh_from_helper, &buf, 65535);
137 GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Read error for header from vpn-helper: %m\n");
138 GNUNET_SCHEDULER_add_now(mycls.sched, restart_helper, cls);
142 /* FIXME */ GNUNET_SERVER_mst_receive(mycls.mst, NULL, buf, t, 0, 0);
144 GNUNET_SCHEDULER_add_read_file (mycls.sched, GNUNET_TIME_UNIT_FOREVER_REL, mycls.fh_from_helper, &helper_read, NULL);
147 static uint16_t calculate_ip_checksum(uint16_t* hdr, short len) {
149 for(; len >= 2; len -= 2)
152 sum += *((unsigned char*)hdr);
154 sum = (sum >> 16) + (sum & 0xFFFF);
159 static void helper_write(void* cls, const struct GNUNET_SCHEDULER_TaskContext* tsdkctx) {
160 if (tsdkctx->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)
162 struct answer_packet_list* ans = mycls.answer_proc_head;
163 size_t len = ntohs(ans->pkt.hdr.size);
165 GNUNET_assert(ans->pkt.subtype == GNUNET_DNS_ANSWER_TYPE_IP);
167 size_t data_len = len - sizeof(struct answer_packet) + 1;
168 size_t net_len = sizeof(struct ip_hdr) + sizeof(struct udp_dns) + data_len;
169 size_t pkt_len = sizeof(struct GNUNET_MessageHeader) + sizeof(struct pkt_tun) + net_len;
171 struct ip_udp_dns* pkt = alloca(pkt_len);
172 memset(pkt, 0, pkt_len);
174 pkt->shdr.size = htons(pkt_len);
175 pkt->shdr.type = htons(GNUNET_MESSAGE_TYPE_VPN_HELPER);
178 pkt->tun.type = htons(0x0800);
180 pkt->ip_hdr.version = 4;
181 pkt->ip_hdr.hdr_lngth = 5;
182 pkt->ip_hdr.diff_serv = 0;
183 pkt->ip_hdr.tot_lngth = htons(net_len);
184 pkt->ip_hdr.ident = 0;
185 pkt->ip_hdr.flags = 0;
186 pkt->ip_hdr.frag_off = 0;
187 pkt->ip_hdr.ttl = 255;
188 pkt->ip_hdr.proto = 0x11; /* UDP */
189 pkt->ip_hdr.chks = 0; /* Will be calculated later*/
190 pkt->ip_hdr.sadr = ans->pkt.from;
191 pkt->ip_hdr.dadr = ans->pkt.to;
193 pkt->ip_hdr.chks = calculate_ip_checksum((uint16_t*)&pkt->ip_hdr, 5*4);
195 pkt->udp_dns.udp_hdr.spt = htons(53);
196 pkt->udp_dns.udp_hdr.dpt = ans->pkt.dst_port;
197 pkt->udp_dns.udp_hdr.len = htons(net_len - sizeof(struct ip_hdr));
198 pkt->udp_dns.udp_hdr.crc = 0; /* Optional for IPv4 */
200 memcpy(&pkt->udp_dns.data, ans->pkt.data, data_len);
202 GNUNET_CONTAINER_DLL_remove (mycls.answer_proc_head, mycls.answer_proc_tail, ans);
205 /* FIXME */ GNUNET_DISK_file_write(mycls.fh_to_helper, pkt, pkt_len);
207 if (mycls.answer_proc_head != NULL)
208 GNUNET_SCHEDULER_add_write_file (mycls.sched, GNUNET_TIME_UNIT_FOREVER_REL, mycls.fh_to_helper, &helper_write, NULL);
211 size_t send_query(void* cls, size_t size, void* buf)
214 if (mycls.restart_hijack == 1)
216 mycls.restart_hijack = 0;
217 GNUNET_assert(sizeof(struct GNUNET_MessageHeader) >= size);
218 struct GNUNET_MessageHeader* hdr = buf;
219 len = sizeof(struct GNUNET_MessageHeader);
220 hdr->size = htons(len);
221 hdr->type = htons(GNUNET_MESSAGE_TYPE_REHIJACK);
225 struct query_packet_list* query = mycls.head;
226 len = ntohs(query->pkt.hdr.size);
228 GNUNET_assert(len <= size);
230 memcpy(buf, &query->pkt.hdr, len);
232 GNUNET_CONTAINER_DLL_remove (mycls.head, mycls.tail, query);
237 if (mycls.head != NULL || mycls.restart_hijack == 1) {
238 GNUNET_CLIENT_notify_transmit_ready(mycls.dns_connection, ntohs(mycls.head->pkt.hdr.size), GNUNET_TIME_UNIT_FOREVER_REL, GNUNET_YES, &send_query, NULL);
244 static void message_token(void *cls, void *client, const struct GNUNET_MessageHeader *message) {
245 if (ntohs(message->type) != GNUNET_MESSAGE_TYPE_VPN_HELPER) return;
247 struct tun_pkt *pkt_tun = (struct tun_pkt*) message;
249 if (ntohs(pkt_tun->tun.type) == 0x86dd) {
250 struct ip6_pkt *pkt6 = (struct ip6_pkt*) message;
251 struct ip6_tcp *pkt6_tcp;
252 struct ip6_udp *pkt6_udp;
255 switch(pkt6->ip6_hdr.nxthdr) {
257 pkt6_tcp = (struct ip6_tcp*)pkt6;
258 pkt_printf_ip6tcp(pkt6_tcp);
261 pkt6_udp = (struct ip6_udp*)pkt6;
262 pkt_printf_ip6udp(pkt6_udp);
263 if (ntohs(pkt6_udp->udp_hdr.dpt) == 53) {
264 pkt_printf_ip6dns((struct ip6_udp_dns*)pkt6_udp);
268 } else if (ntohs(pkt_tun->tun.type) == 0x0800) {
269 struct ip_pkt *pkt = (struct ip_pkt*) message;
270 struct ip_udp *udp = (struct ip_udp*) message;
271 GNUNET_assert(pkt->ip_hdr.version == 4);
272 if (pkt->ip_hdr.proto == 0x11 && ntohs(udp->udp_hdr.dpt) == 53 ) {
273 size_t len = sizeof(struct query_packet) + ntohs(udp->udp_hdr.len) - 9; /* 9 = 8 for the udp-header + 1 for the unsigned char data[1]; */
274 struct query_packet_list* query = GNUNET_malloc(len + 2*sizeof(struct query_packet_list*));
275 query->pkt.hdr.type = htons(GNUNET_MESSAGE_TYPE_LOCAL_QUERY_DNS);
276 query->pkt.hdr.size = htons(len);
277 query->pkt.orig_to = pkt->ip_hdr.dadr;
278 query->pkt.orig_from = pkt->ip_hdr.sadr;
279 query->pkt.src_port = udp->udp_hdr.spt;
280 memcpy(query->pkt.data, udp->data, ntohs(udp->udp_hdr.len) - 8);
282 GNUNET_CONTAINER_DLL_insert_after(mycls.head, mycls.tail, mycls.tail, query);
284 if (mycls.dns_connection != NULL)
285 /* struct GNUNET_CLIENT_TransmitHandle* th = */ GNUNET_CLIENT_notify_transmit_ready(mycls.dns_connection, len, GNUNET_TIME_UNIT_FOREVER_REL, GNUNET_YES, &send_query, NULL);
292 dns_answer_handler(void* cls, const struct GNUNET_MessageHeader *msg);
295 reconnect_to_service_dns (void *cls,
296 const struct GNUNET_SCHEDULER_TaskContext *tc) {
297 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
299 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Connecting\n");
300 GNUNET_assert (mycls.dns_connection == NULL);
301 mycls.dns_connection = GNUNET_CLIENT_connect (mycls.sched, "dns", mycls.cfg);
302 GNUNET_CLIENT_receive(mycls.dns_connection, &dns_answer_handler, NULL, GNUNET_TIME_UNIT_FOREVER_REL);
303 if (mycls.head != NULL)
304 /* struct GNUNET_CLIENT_TransmitHandle* th = */ GNUNET_CLIENT_notify_transmit_ready(mycls.dns_connection, ntohs(mycls.head->pkt.hdr.size), GNUNET_TIME_UNIT_FOREVER_REL, GNUNET_YES, &send_query, NULL);
308 process_answer(void* cls, const struct GNUNET_SCHEDULER_TaskContext* tc) {
309 struct answer_packet* pkt = cls;
311 if (pkt->subtype == GNUNET_DNS_ANSWER_TYPE_SERVICE)
313 pkt->subtype = GNUNET_DNS_ANSWER_TYPE_IP;
314 unsigned char ip6addr[16];
315 memcpy(ip6addr, (int[]){htons(0x1234)}, 2);
316 memcpy(ip6addr+2, &pkt->peer, 7);
317 memcpy(ip6addr+9, &pkt->service_descriptor, 7);
319 memcpy(((char*)pkt)+ntohs(pkt->addroffset), ip6addr, 16);
322 * -save DNS_Record into hashmap, pointed to by ip
323 * -regularily walk through hashmap, deleting old entries
324 * when is an entry old?
325 * have a last-used field
326 * don't remove if last-used "recent", ask dht again if record expired
330 struct answer_packet_list* list = GNUNET_malloc(htons(pkt->hdr.size) + 2*sizeof(struct answer_packet_list*));
332 memcpy(&list->pkt, pkt, htons(pkt->hdr.size));
334 GNUNET_CONTAINER_DLL_insert_after(mycls.answer_proc_head, mycls.answer_proc_tail, mycls.answer_proc_tail, list);
336 GNUNET_SCHEDULER_add_write_file (mycls.sched, GNUNET_TIME_UNIT_FOREVER_REL, mycls.fh_to_helper, &helper_write, NULL);
342 dns_answer_handler(void* cls, const struct GNUNET_MessageHeader *msg)
346 GNUNET_CLIENT_disconnect(mycls.dns_connection, GNUNET_NO);
347 mycls.dns_connection = NULL;
348 GNUNET_SCHEDULER_add_delayed (mycls.sched,
349 GNUNET_TIME_UNIT_SECONDS,
350 &reconnect_to_service_dns,
355 if (msg->type != htons(GNUNET_MESSAGE_TYPE_LOCAL_RESPONSE_DNS))
358 GNUNET_CLIENT_disconnect(mycls.dns_connection, GNUNET_NO);
359 mycls.dns_connection = NULL;
360 GNUNET_SCHEDULER_add_now (mycls.sched,
361 &reconnect_to_service_dns,
365 void *pkt = GNUNET_malloc(ntohs(msg->size));
367 memcpy(pkt, msg, ntohs(msg->size));
369 GNUNET_SCHEDULER_add_now(mycls.sched, process_answer, pkt);
370 GNUNET_CLIENT_receive(mycls.dns_connection, &dns_answer_handler, NULL, GNUNET_TIME_UNIT_FOREVER_REL);
374 * Main function that will be run by the scheduler.
377 * @param sched the scheduler to use
378 * @param args remaining command-line arguments
379 * @param cfgfile name of the configuration file used (for saving, can be NULL!)
380 * @param cfg configuration
384 struct GNUNET_SCHEDULER_Handle *sched,
387 const struct GNUNET_CONFIGURATION_Handle *cfg)
390 mycls.mst = GNUNET_SERVER_mst_create(&message_token, NULL);
392 mycls.restart_hijack = 0;
393 GNUNET_SCHEDULER_add_now (sched, &reconnect_to_service_dns, NULL);
394 GNUNET_SCHEDULER_add_delayed(sched, GNUNET_TIME_UNIT_FOREVER_REL, &cleanup, cls);
395 GNUNET_SCHEDULER_add_now (sched, start_helper_and_schedule, NULL);
400 * The main function to obtain template from gnunetd.
402 * @param argc number of arguments from the command line
403 * @param argv command line arguments
404 * @return 0 ok, 1 on error
407 main (int argc, char *const *argv)
409 static const struct GNUNET_GETOPT_CommandLineOption options[] = {
410 GNUNET_GETOPT_OPTION_END
414 GNUNET_PROGRAM_run (argc,
417 gettext_noop ("help text"),
418 options, &run, NULL)) ? ret : 1;
421 /* end of gnunet-daemon-vpn.c */