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"
46 struct GNUNET_DISK_PipeHandle* helper_in; // From the helper
47 struct GNUNET_DISK_PipeHandle* helper_out; // To the helper
48 const struct GNUNET_DISK_FileHandle* fh_from_helper;
49 const struct GNUNET_DISK_FileHandle* fh_to_helper;
51 struct GNUNET_SERVER_MessageStreamTokenizer* mst;
53 struct GNUNET_SCHEDULER_Handle *sched;
55 struct GNUNET_CLIENT_Connection *dns_connection;
59 struct query_packet_list *head;
60 struct query_packet_list *tail;
62 struct answer_packet_list *answer_head;
63 struct answer_packet_list *answer_tail;
66 static struct vpn_cls mycls;
68 static void cleanup(void* cls, const struct GNUNET_SCHEDULER_TaskContext* tskctx) {
69 if (tskctx->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) {
70 PLIBC_KILL(mycls.helper_pid, SIGTERM);
71 GNUNET_OS_process_wait(mycls.helper_pid);
75 static void helper_read(void* cls, const struct GNUNET_SCHEDULER_TaskContext* tsdkctx);
77 static void start_helper_and_schedule() {
78 mycls.helper_in = GNUNET_DISK_pipe (GNUNET_YES, GNUNET_YES, GNUNET_NO);;
79 mycls.helper_out = GNUNET_DISK_pipe (GNUNET_YES, GNUNET_NO, GNUNET_YES);
81 if (mycls.helper_in == NULL || mycls.helper_out == NULL) return;
83 mycls.helper_pid = GNUNET_OS_start_process(mycls.helper_in, mycls.helper_out, "gnunet-helper-vpn", "gnunet-helper-vpn", NULL);
85 mycls.fh_from_helper = GNUNET_DISK_pipe_handle (mycls.helper_out, GNUNET_DISK_PIPE_END_READ);
86 mycls.fh_to_helper = GNUNET_DISK_pipe_handle (mycls.helper_in, GNUNET_DISK_PIPE_END_WRITE);
88 GNUNET_DISK_pipe_close_end(mycls.helper_out, GNUNET_DISK_PIPE_END_WRITE);
89 GNUNET_DISK_pipe_close_end(mycls.helper_in, GNUNET_DISK_PIPE_END_READ);
91 GNUNET_SCHEDULER_add_read_file (mycls.sched, GNUNET_TIME_UNIT_FOREVER_REL, mycls.fh_from_helper, &helper_read, NULL);
95 static void restart_helper(void* cls, const struct GNUNET_SCHEDULER_TaskContext* tskctx) {
96 // FIXME: Ratelimit this!
99 PLIBC_KILL(mycls.helper_pid, SIGKILL);
100 GNUNET_OS_process_wait(mycls.helper_pid);
102 // FIXME: send msg to service-dns -- the hijacker has to be started again, too, the routing table is flushed if it depends on one interface
104 GNUNET_DISK_pipe_close(mycls.helper_in);
105 GNUNET_DISK_pipe_close(mycls.helper_out);
107 // Restart the helper
108 start_helper_and_schedule(mycls);
112 static void helper_read(void* cls, const struct GNUNET_SCHEDULER_TaskContext* tsdkctx) {
115 if (tsdkctx->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)
118 int t = GNUNET_DISK_file_read(mycls.fh_from_helper, &buf, 65535);
120 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Read error for header: %m\n");
121 GNUNET_SCHEDULER_add_now(mycls.sched, restart_helper, cls);
125 /* FIXME */ GNUNET_SERVER_mst_receive(mycls.mst, NULL, buf, t, 0, 0);
127 GNUNET_SCHEDULER_add_read_file (mycls.sched, GNUNET_TIME_UNIT_FOREVER_REL, mycls.fh_from_helper, &helper_read, NULL);
130 static uint16_t calculate_ip_checksum(uint16_t* hdr, short len) {
132 for(; len >= 2; len -= 2)
135 sum += *((unsigned char*)hdr);
137 sum = (sum >> 16) + (sum & 0xFFFF);
142 static void helper_write(void* cls, const struct GNUNET_SCHEDULER_TaskContext* tsdkctx) {
143 if (tsdkctx->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)
145 struct answer_packet_list* ans = mycls.answer_head;
146 size_t len = ntohs(ans->pkt.hdr.size);
148 size_t data_len = len - sizeof(struct answer_packet) + 1;
149 size_t net_len = sizeof(struct ip_hdr) + sizeof(struct udp_dns) + data_len;
150 size_t pkt_len = sizeof(struct GNUNET_MessageHeader) + sizeof(struct pkt_tun) + net_len;
152 struct ip_udp_dns* pkt = alloca(pkt_len);
154 pkt->shdr.size = htons(pkt_len);
155 pkt->shdr.type = htons(GNUNET_MESSAGE_TYPE_VPN_HELPER);
158 pkt->tun.type = htons(0x0800);
160 pkt->ip_hdr.version = 4;
161 pkt->ip_hdr.hdr_lngth = 5;
162 pkt->ip_hdr.diff_serv = 0;
163 pkt->ip_hdr.tot_lngth = htons(net_len);
164 pkt->ip_hdr.ident = 0;
165 pkt->ip_hdr.flags = 0;
166 pkt->ip_hdr.frag_off = 0;
167 pkt->ip_hdr.ttl = 255;
168 pkt->ip_hdr.proto = 0x11; /* UDP */
169 pkt->ip_hdr.chks = 0; /* Will be calculated later*/
170 pkt->ip_hdr.sadr = ans->pkt.from;
171 pkt->ip_hdr.dadr = ans->pkt.to;
173 pkt->ip_hdr.chks = calculate_ip_checksum((uint16_t*)&pkt->ip_hdr, 5*4);
175 pkt->udp_dns.udp_hdr.spt = htons(53);
176 pkt->udp_dns.udp_hdr.dpt = ans->pkt.dst_port;
177 pkt->udp_dns.udp_hdr.len = htons(net_len - sizeof(struct ip_hdr));
178 pkt->udp_dns.udp_hdr.crc = 0; /* Optional for IPv4 */
180 memcpy(&pkt->udp_dns.data, ans->pkt.data, data_len);
182 /* GNUNET_MessageHeader
190 GNUNET_CONTAINER_DLL_remove (mycls.answer_head, mycls.answer_tail, ans);
193 /* FIXME */ GNUNET_DISK_file_write(mycls.fh_to_helper, pkt, pkt_len);
195 if (mycls.answer_head != NULL)
196 GNUNET_SCHEDULER_add_write_file (mycls.sched, GNUNET_TIME_UNIT_FOREVER_REL, mycls.fh_to_helper, &helper_write, NULL);
199 size_t send_query(void* cls, size_t size, void* buf)
201 struct query_packet_list* query = mycls.head;
202 size_t len = ntohs(query->pkt.hdr.size);
204 GNUNET_assert(len <= size);
206 memcpy(buf, &query->pkt.hdr, len);
208 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Sent %d bytes.\n", len);
210 GNUNET_CONTAINER_DLL_remove (mycls.head, mycls.tail, query);
214 if (mycls.head != NULL) {
215 GNUNET_CLIENT_notify_transmit_ready(mycls.dns_connection, ntohs(mycls.head->pkt.hdr.size), GNUNET_TIME_UNIT_FOREVER_REL, GNUNET_YES, &send_query, NULL);
221 static void message_token(void *cls, void *client, const struct GNUNET_MessageHeader *message) {
222 if (ntohs(message->type) != GNUNET_MESSAGE_TYPE_VPN_HELPER) return;
224 struct tun_pkt *pkt_tun = (struct tun_pkt*) message;
226 if (ntohs(pkt_tun->tun.type) == 0x86dd) {
227 struct ip6_pkt *pkt6 = (struct ip6_pkt*) message;
228 struct ip6_tcp *pkt6_tcp;
229 struct ip6_udp *pkt6_udp;
232 switch(pkt6->ip6_hdr.nxthdr) {
234 pkt6_tcp = (struct ip6_tcp*)pkt6;
235 pkt_printf_ip6tcp(pkt6_tcp);
238 pkt6_udp = (struct ip6_udp*)pkt6;
239 pkt_printf_ip6udp(pkt6_udp);
240 if (ntohs(pkt6_udp->udp_hdr.dpt) == 53) {
241 pkt_printf_ip6dns((struct ip6_udp_dns*)pkt6_udp);
245 } else if (ntohs(pkt_tun->tun.type) == 0x0800) {
246 struct ip_pkt *pkt = (struct ip_pkt*) message;
247 struct ip_udp *udp = (struct ip_udp*) message;
248 GNUNET_assert(pkt->ip_hdr.version == 4);
249 if (pkt->ip_hdr.proto == 0x11 && ntohs(udp->udp_hdr.dpt) == 53 ) {
250 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]; */
251 struct query_packet_list* query = GNUNET_malloc(len + 2*sizeof(struct query_packet_list*));
252 query->pkt.hdr.type = htons(GNUNET_MESSAGE_TYPE_LOCAL_QUERY_DNS);
253 query->pkt.hdr.size = htons(len);
254 query->pkt.orig_to = pkt->ip_hdr.dadr;
255 query->pkt.orig_from = pkt->ip_hdr.sadr;
256 query->pkt.src_port = udp->udp_hdr.spt;
257 memcpy(query->pkt.data, udp->data, ntohs(udp->udp_hdr.len) - 8);
259 GNUNET_CONTAINER_DLL_insert_after(mycls.head, mycls.tail, mycls.tail, query);
261 struct GNUNET_CLIENT_TransmitHandle* th = GNUNET_CLIENT_notify_transmit_ready(mycls.dns_connection, len, GNUNET_TIME_UNIT_FOREVER_REL, GNUNET_YES, &send_query, NULL);
263 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Queued sending of %d bytes.\n", len);
265 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Already queued for %d bytes.\n", len);
271 void dns_answer_handler(void* cls, const struct GNUNET_MessageHeader *msg) {
272 if (msg == NULL) return;
273 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Got an answer!\n");
275 if (msg->type != htons(GNUNET_MESSAGE_TYPE_LOCAL_RESPONSE_DNS)) goto out;
277 struct answer_packet_list* pkt = GNUNET_malloc(ntohs(msg->size) + 2*sizeof(struct answer_packet_list*));
279 memcpy(&pkt->pkt, msg, ntohs(msg->size));
281 GNUNET_CONTAINER_DLL_insert_after(mycls.answer_head, mycls.answer_tail, mycls.answer_tail, pkt);
283 GNUNET_SCHEDULER_add_write_file (mycls.sched, GNUNET_TIME_UNIT_FOREVER_REL, mycls.fh_to_helper, &helper_write, NULL);
286 GNUNET_CLIENT_receive(mycls.dns_connection, &dns_answer_handler, NULL, GNUNET_TIME_UNIT_FOREVER_REL);
290 * Main function that will be run by the scheduler.
293 * @param sched the scheduler to use
294 * @param args remaining command-line arguments
295 * @param cfgfile name of the configuration file used (for saving, can be NULL!)
296 * @param cfg configuration
300 struct GNUNET_SCHEDULER_Handle *sched,
303 const struct GNUNET_CONFIGURATION_Handle *cfg)
306 mycls.mst = GNUNET_SERVER_mst_create(&message_token, NULL);
308 mycls.dns_connection = GNUNET_CLIENT_connect (sched, "dns", cfg);
309 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Connection: %x\n", mycls.dns_connection);
311 GNUNET_CLIENT_receive(mycls.dns_connection, &dns_answer_handler, NULL, GNUNET_TIME_UNIT_FOREVER_REL);
313 GNUNET_SCHEDULER_add_delayed(sched, GNUNET_TIME_UNIT_FOREVER_REL, &cleanup, cls);
314 start_helper_and_schedule(mycls);
319 * The main function to obtain template from gnunetd.
321 * @param argc number of arguments from the command line
322 * @param argv command line arguments
323 * @return 0 ok, 1 on error
326 main (int argc, char *const *argv)
328 static const struct GNUNET_GETOPT_CommandLineOption options[] = {
329 GNUNET_GETOPT_OPTION_END
333 GNUNET_PROGRAM_run (argc,
336 gettext_noop ("help text"),
337 options, &run, NULL)) ? ret : 1;
340 /* end of gnunet-daemon-vpn.c */