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-helper.c
24 * @author Philipp Toelke
27 #include <gnunet_common.h>
28 #include <gnunet_client_lib.h>
29 #include <gnunet_os_lib.h>
30 #include <gnunet_mesh_service.h>
31 #include <gnunet_protocols.h>
32 #include <gnunet_server_lib.h>
33 #include <gnunet_container_lib.h>
34 #include <block_dns.h>
35 #include <gnunet_configuration_lib.h>
36 #include <gnunet_applications.h>
38 #include "gnunet-daemon-vpn-dns.h"
39 #include "gnunet-daemon-vpn.h"
40 #include "gnunet-daemon-vpn-helper.h"
41 #include "gnunet-service-dns-p.h"
42 #include "gnunet-vpn-packet.h"
43 #include "gnunet-vpn-checksum.h"
44 #include "gnunet-helper-vpn-api.h"
46 struct GNUNET_VPN_HELPER_Handle *helper_handle;
49 * The tunnels that will be used to send tcp- and udp-packets
51 static struct GNUNET_MESH_Tunnel *tcp_tunnel;
52 static struct GNUNET_MESH_Tunnel *udp_tunnel;
55 * Start the helper-process
57 * If cls != NULL it is assumed that this function is called as a result of a dying
58 * helper. cls is then taken as handle to the old helper and is cleaned up.
62 start_helper_and_schedule (void *cls,
63 const struct GNUNET_SCHEDULER_TaskContext *tc)
65 shs_task = GNUNET_SCHEDULER_NO_TASK;
66 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
80 GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "IFNAME", &ifname))
82 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
83 "No entry 'IFNAME' in configuration!\n");
88 GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "IPV6ADDR", &ipv6addr))
90 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
91 "No entry 'IPV6ADDR' in configuration!\n");
96 GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "IPV6PREFIX",
99 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
100 "No entry 'IPV6PREFIX' in configuration!\n");
105 GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "IPV4ADDR", &ipv4addr))
107 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
108 "No entry 'IPV4ADDR' in configuration!\n");
113 GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "IPV4MASK", &ipv4mask))
115 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
116 "No entry 'IPV4MASK' in configuration!\n");
121 * Messages get passed to the function message_token
122 * When the helper dies, this function will be called again with the
123 * helper_handle as cls.
125 helper_handle = start_helper (ifname,
131 start_helper_and_schedule, message_token, NULL);
133 GNUNET_free (ipv6addr);
134 GNUNET_free (ipv6prefix);
135 GNUNET_free (ipv4addr);
136 GNUNET_free (ipv4mask);
137 GNUNET_free (ifname);
139 /* Tell the dns-service to rehijack the dns-port
140 * The routing-table gets flushed if an interface disappears.
143 if (NULL != dns_connection)
144 GNUNET_CLIENT_notify_transmit_ready (dns_connection,
145 sizeof (struct GNUNET_MessageHeader),
146 GNUNET_TIME_UNIT_FOREVER_REL,
147 GNUNET_YES, &send_query, NULL);
149 GNUNET_SCHEDULER_add_write_file (GNUNET_TIME_UNIT_FOREVER_REL,
150 helper_handle->fh_to_helper, &helper_write,
157 * Send an dns-answer-packet to the helper
160 helper_write (void *cls
161 __attribute__ ((unused)),
162 const struct GNUNET_SCHEDULER_TaskContext *tsdkctx)
164 if (tsdkctx->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)
167 struct answer_packet_list *ans = answer_proc_head;
172 size_t len = ntohs (ans->pkt.hdr.size);
174 GNUNET_assert (ans->pkt.subtype == GNUNET_DNS_ANSWER_TYPE_IP);
176 GNUNET_assert (20 == sizeof (struct ip_hdr));
177 GNUNET_assert (8 == sizeof (struct udp_pkt));
178 size_t data_len = len - sizeof (struct answer_packet) + 1;
179 size_t net_len = sizeof (struct ip_hdr) + sizeof (struct udp_dns) + data_len;
181 sizeof (struct GNUNET_MessageHeader) + sizeof (struct pkt_tun) + net_len;
183 struct ip_udp_dns *pkt = alloca (pkt_len);
185 GNUNET_assert (pkt != NULL);
186 memset (pkt, 0, pkt_len);
188 /* set the gnunet-header */
189 pkt->shdr.size = htons (pkt_len);
190 pkt->shdr.type = htons (GNUNET_MESSAGE_TYPE_VPN_HELPER);
192 /* set the tun-header (no flags and ethertype of IPv4) */
194 pkt->tun.type = htons (0x0800);
196 /* set the ip-header */
197 pkt->ip_hdr.version = 4;
198 pkt->ip_hdr.hdr_lngth = 5;
199 pkt->ip_hdr.diff_serv = 0;
200 pkt->ip_hdr.tot_lngth = htons (net_len);
201 pkt->ip_hdr.ident = 0;
202 pkt->ip_hdr.flags = 0;
203 pkt->ip_hdr.frag_off = 0;
204 pkt->ip_hdr.ttl = 255;
205 pkt->ip_hdr.proto = 0x11; /* UDP */
206 pkt->ip_hdr.chks = 0; /* Will be calculated later */
207 pkt->ip_hdr.sadr = ans->pkt.from;
208 pkt->ip_hdr.dadr = ans->pkt.to;
210 pkt->ip_hdr.chks = calculate_ip_checksum ((uint16_t *) & pkt->ip_hdr, 5 * 4);
212 /* set the udp-header */
213 pkt->udp_dns.udp_hdr.spt = htons (53);
214 pkt->udp_dns.udp_hdr.dpt = ans->pkt.dst_port;
215 pkt->udp_dns.udp_hdr.len = htons (net_len - sizeof (struct ip_hdr));
216 pkt->udp_dns.udp_hdr.crc = 0; /* Optional for IPv4 */
218 memcpy (&pkt->udp_dns.data, ans->pkt.data, data_len);
220 GNUNET_CONTAINER_DLL_remove (answer_proc_head, answer_proc_tail, ans);
223 if (GNUNET_DISK_file_write (helper_handle->fh_to_helper, pkt, pkt_len) < 0)
225 cleanup_helper (helper_handle);
226 GNUNET_SCHEDULER_add_now (start_helper_and_schedule, NULL);
230 /* if more packets are available, reschedule */
231 if (answer_proc_head != NULL)
232 GNUNET_SCHEDULER_add_write_file (GNUNET_TIME_UNIT_FOREVER_REL,
233 helper_handle->fh_to_helper,
234 &helper_write, NULL);
238 * Receive packets from the helper-process
241 message_token (void *cls __attribute__ ((unused)),
243 __attribute__ ((unused)),
244 const struct GNUNET_MessageHeader *message)
246 GNUNET_assert (ntohs (message->type) == GNUNET_MESSAGE_TYPE_VPN_HELPER);
248 struct tun_pkt *pkt_tun = (struct tun_pkt *) message;
249 GNUNET_HashCode *key;
251 /* ethertype is ipv6 */
252 if (ntohs (pkt_tun->tun.type) == 0x86dd)
254 struct ip6_pkt *pkt6 = (struct ip6_pkt *) message;
256 GNUNET_assert (pkt6->ip6_hdr.version == 6);
257 struct ip6_tcp *pkt6_tcp;
258 struct ip6_udp *pkt6_udp;
259 struct ip6_icmp *pkt6_icmp;
261 switch (pkt6->ip6_hdr.nxthdr)
265 pkt6_tcp = (struct ip6_tcp *) pkt6;
266 pkt6_udp = (struct ip6_udp *) pkt6;
268 if ((key = address6_mapping_exists (pkt6->ip6_hdr.dadr)) != NULL)
270 struct map_entry *me = GNUNET_CONTAINER_multihashmap_get (hashmap, key);
272 GNUNET_assert (me != NULL);
276 sizeof (struct GNUNET_MESH_Tunnel *) +
277 sizeof (struct GNUNET_MessageHeader) +
278 sizeof (GNUNET_HashCode) + ntohs (pkt6->ip6_hdr.paylgth);
280 struct GNUNET_MESH_Tunnel **cls = GNUNET_malloc (size);
281 struct GNUNET_MessageHeader *hdr =
282 (struct GNUNET_MessageHeader *) (cls + 1);
283 GNUNET_HashCode *hc = (GNUNET_HashCode *) (hdr + 1);
285 hdr->size = htons (sizeof (struct GNUNET_MessageHeader) +
286 sizeof (GNUNET_HashCode) +
287 ntohs (pkt6->ip6_hdr.paylgth));
289 GNUNET_MESH_ApplicationType app_type;
291 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "me->addrlen is %d\n",
293 if (me->addrlen == 0)
295 /* This is a mapping to a gnunet-service */
296 memcpy (hc, &me->desc.service_descriptor, sizeof (GNUNET_HashCode));
298 if (0x11 == pkt6->ip6_hdr.nxthdr
299 && (me->desc.service_type & htonl (GNUNET_DNS_SERVICE_TYPE_UDP))
300 && (port_in_ports (me->desc.ports, pkt6_udp->udp_hdr.dpt)
301 || testBit (me->additional_ports,
302 ntohs (pkt6_udp->udp_hdr.dpt))))
304 hdr->type = ntohs (GNUNET_MESSAGE_TYPE_VPN_SERVICE_UDP);
306 memcpy (hc + 1, &pkt6_udp->udp_hdr, ntohs (pkt6_udp->udp_hdr.len));
309 else if (0x06 == pkt6->ip6_hdr.nxthdr
311 service_type & htonl (GNUNET_DNS_SERVICE_TYPE_TCP)) &&
312 (port_in_ports (me->desc.ports, pkt6_tcp->tcp_hdr.dpt)))
314 hdr->type = ntohs (GNUNET_MESSAGE_TYPE_VPN_SERVICE_TCP);
316 memcpy (hc + 1, &pkt6_tcp->tcp_hdr, ntohs (pkt6->ip6_hdr.paylgth));
319 if (me->tunnel == NULL && NULL != cls)
322 GNUNET_MESH_peer_request_connect_all (mesh_handle,
323 GNUNET_TIME_UNIT_FOREVER_REL,
332 else if (NULL != cls)
335 send_pkt_to_peer (cls, (struct GNUNET_PeerIdentity *) 1, NULL);
336 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
337 "Queued to send to peer %x, type %d\n",
338 *((unsigned int *) &me->desc.peer), ntohs (hdr->type));
343 /* This is a mapping to a "real" address */
344 struct remote_addr *s = (struct remote_addr *) hc;
346 s->addrlen = me->addrlen;
347 memcpy (s->addr, me->addr, me->addrlen);
348 s->proto = pkt6->ip6_hdr.nxthdr;
349 if (s->proto == 0x11)
351 hdr->type = htons (GNUNET_MESSAGE_TYPE_VPN_REMOTE_UDP);
352 memcpy (hc + 1, &pkt6_udp->udp_hdr, ntohs (pkt6_udp->udp_hdr.len));
353 app_type = GNUNET_APPLICATION_TYPE_INTERNET_UDP_GATEWAY;
354 if (NULL != udp_tunnel)
355 me->tunnel = udp_tunnel;
357 else if (s->proto == 0x06)
359 hdr->type = htons (GNUNET_MESSAGE_TYPE_VPN_REMOTE_TCP);
360 memcpy (hc + 1, &pkt6_tcp->tcp_hdr, ntohs (pkt6->ip6_hdr.paylgth));
361 app_type = GNUNET_APPLICATION_TYPE_INTERNET_TCP_GATEWAY;
362 if (NULL != tcp_tunnel)
363 me->tunnel = tcp_tunnel;
365 if (me->tunnel == NULL && NULL != cls)
367 *cls = GNUNET_MESH_peer_request_connect_by_type (mesh_handle,
368 GNUNET_TIME_UNIT_FOREVER_REL,
373 if (GNUNET_APPLICATION_TYPE_INTERNET_UDP_GATEWAY == app_type)
375 else if (GNUNET_APPLICATION_TYPE_INTERNET_TCP_GATEWAY == app_type)
378 else if (NULL != cls)
381 send_pkt_to_peer (cls, (struct GNUNET_PeerIdentity *) 1, NULL);
387 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
388 "Packet to %02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x, which has no mapping\n",
389 pkt6->ip6_hdr.dadr[0], pkt6->ip6_hdr.dadr[1],
390 pkt6->ip6_hdr.dadr[2], pkt6->ip6_hdr.dadr[3],
391 pkt6->ip6_hdr.dadr[4], pkt6->ip6_hdr.dadr[5],
392 pkt6->ip6_hdr.dadr[6], pkt6->ip6_hdr.dadr[7],
393 pkt6->ip6_hdr.dadr[8], pkt6->ip6_hdr.dadr[9],
394 pkt6->ip6_hdr.dadr[10], pkt6->ip6_hdr.dadr[11],
395 pkt6->ip6_hdr.dadr[12], pkt6->ip6_hdr.dadr[13],
396 pkt6->ip6_hdr.dadr[14], pkt6->ip6_hdr.dadr[15]);
401 pkt6_icmp = (struct ip6_icmp *) pkt6;
402 /* If this packet is an icmp-echo-request and a mapping exists, answer */
403 if (pkt6_icmp->icmp_hdr.type == 0x80
404 && (key = address6_mapping_exists (pkt6->ip6_hdr.dadr)) != NULL)
407 pkt6_icmp = GNUNET_malloc (ntohs (pkt6->shdr.size));
408 memcpy (pkt6_icmp, pkt6, ntohs (pkt6->shdr.size));
409 GNUNET_SCHEDULER_add_now (&send_icmp6_response, pkt6_icmp);
414 /* ethertype is ipv4 */
415 else if (ntohs (pkt_tun->tun.type) == 0x0800)
417 struct ip_pkt *pkt = (struct ip_pkt *) message;
418 struct ip_udp *udp = (struct ip_udp *) message;
419 struct ip_tcp *pkt_tcp;
420 struct ip_udp *pkt_udp;
421 struct ip_icmp *pkt_icmp;
423 GNUNET_assert (pkt->ip_hdr.version == 4);
425 /* Send dns-packets to the service-dns */
426 if (pkt->ip_hdr.proto == 0x11 && ntohs (udp->udp_hdr.dpt) == 53)
428 /* 9 = 8 for the udp-header + 1 for the unsigned char data[1]; */
429 size_t len = sizeof (struct query_packet) + ntohs (udp->udp_hdr.len) - 9;
431 struct query_packet_list *query =
432 GNUNET_malloc (len + 2 * sizeof (struct query_packet_list *));
433 query->pkt.hdr.type = htons (GNUNET_MESSAGE_TYPE_VPN_DNS_LOCAL_QUERY_DNS);
434 query->pkt.hdr.size = htons (len);
435 query->pkt.orig_to = pkt->ip_hdr.dadr;
436 query->pkt.orig_from = pkt->ip_hdr.sadr;
437 query->pkt.src_port = udp->udp_hdr.spt;
438 memcpy (query->pkt.data, udp->data, ntohs (udp->udp_hdr.len) - 8);
440 GNUNET_CONTAINER_DLL_insert_after (head, tail, tail, query);
442 GNUNET_assert (head != NULL);
444 if (dns_connection != NULL)
445 GNUNET_CLIENT_notify_transmit_ready (dns_connection,
447 GNUNET_TIME_UNIT_FOREVER_REL,
448 GNUNET_YES, &send_query, NULL);
452 uint32_t dadr = pkt->ip_hdr.dadr;
453 unsigned char *c = (unsigned char *) &dadr;
455 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Packet to %d.%d.%d.%d, proto %x\n",
456 c[0], c[1], c[2], c[3], pkt->ip_hdr.proto);
457 switch (pkt->ip_hdr.proto)
461 pkt_tcp = (struct ip_tcp *) pkt;
462 pkt_udp = (struct ip_udp *) pkt;
464 if ((key = address4_mapping_exists (dadr)) != NULL)
466 struct map_entry *me =
467 GNUNET_CONTAINER_multihashmap_get (hashmap, key);
468 GNUNET_assert (me != NULL);
472 sizeof (struct GNUNET_MESH_Tunnel *) +
473 sizeof (struct GNUNET_MessageHeader) +
474 sizeof (GNUNET_HashCode) + ntohs (pkt->ip_hdr.tot_lngth) -
475 4 * pkt->ip_hdr.hdr_lngth;
477 struct GNUNET_MESH_Tunnel **cls = GNUNET_malloc (size);
478 struct GNUNET_MessageHeader *hdr =
479 (struct GNUNET_MessageHeader *) (cls + 1);
480 GNUNET_HashCode *hc = (GNUNET_HashCode *) (hdr + 1);
483 htons (sizeof (struct GNUNET_MessageHeader) +
484 sizeof (GNUNET_HashCode) + ntohs (pkt->ip_hdr.tot_lngth) -
485 4 * pkt->ip_hdr.hdr_lngth);
487 GNUNET_MESH_ApplicationType app_type;
489 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "me->addrlen is %d\n",
491 if (me->addrlen == 0)
493 /* This is a mapping to a gnunet-service */
494 memcpy (hc, &me->desc.service_descriptor, sizeof (GNUNET_HashCode));
496 if (0x11 == pkt->ip_hdr.proto
497 && (me->desc.service_type & htonl (GNUNET_DNS_SERVICE_TYPE_UDP))
498 && (port_in_ports (me->desc.ports, pkt_udp->udp_hdr.dpt)
499 || testBit (me->additional_ports,
500 ntohs (pkt_udp->udp_hdr.dpt))))
502 hdr->type = ntohs (GNUNET_MESSAGE_TYPE_VPN_SERVICE_UDP);
504 memcpy (hc + 1, &pkt_udp->udp_hdr, ntohs (pkt_udp->udp_hdr.len));
507 else if (0x06 == pkt->ip_hdr.proto
508 && (me->desc.service_type &
509 htonl (GNUNET_DNS_SERVICE_TYPE_TCP)) &&
510 (port_in_ports (me->desc.ports, pkt_tcp->tcp_hdr.dpt)))
512 hdr->type = ntohs (GNUNET_MESSAGE_TYPE_VPN_SERVICE_TCP);
514 memcpy (hc + 1, &pkt_tcp->tcp_hdr,
515 ntohs (pkt->ip_hdr.tot_lngth) -
516 4 * pkt->ip_hdr.hdr_lngth);
519 if (me->tunnel == NULL && NULL != cls)
522 GNUNET_MESH_peer_request_connect_all (mesh_handle,
523 GNUNET_TIME_UNIT_FOREVER_REL,
532 else if (NULL != cls)
535 send_pkt_to_peer (cls, (struct GNUNET_PeerIdentity *) 1, NULL);
536 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
537 "Queued to send to peer %x, type %d\n",
538 *((unsigned int *) &me->desc.peer),
544 /* This is a mapping to a "real" address */
545 struct remote_addr *s = (struct remote_addr *) hc;
547 s->addrlen = me->addrlen;
548 memcpy (s->addr, me->addr, me->addrlen);
549 s->proto = pkt->ip_hdr.proto;
550 if (s->proto == 0x11)
552 hdr->type = htons (GNUNET_MESSAGE_TYPE_VPN_REMOTE_UDP);
553 memcpy (hc + 1, &pkt_udp->udp_hdr, ntohs (pkt_udp->udp_hdr.len));
554 app_type = GNUNET_APPLICATION_TYPE_INTERNET_UDP_GATEWAY;
556 else if (s->proto == 0x06)
558 hdr->type = htons (GNUNET_MESSAGE_TYPE_VPN_REMOTE_TCP);
559 memcpy (hc + 1, &pkt_tcp->tcp_hdr,
560 ntohs (pkt->ip_hdr.tot_lngth) -
561 4 * pkt->ip_hdr.hdr_lngth);
562 app_type = GNUNET_APPLICATION_TYPE_INTERNET_TCP_GATEWAY;
564 if (me->tunnel == NULL && NULL != cls)
566 *cls = GNUNET_MESH_peer_request_connect_by_type (mesh_handle,
567 GNUNET_TIME_UNIT_FOREVER_REL,
573 else if (NULL != cls)
576 send_pkt_to_peer (cls, (struct GNUNET_PeerIdentity *) 1, NULL);
582 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
583 "Packet to %x which has no mapping\n", dadr);
588 pkt_icmp = (struct ip_icmp *) pkt;
589 if (pkt_icmp->icmp_hdr.type == 0x8 &&
590 (key = address4_mapping_exists (dadr)) != NULL)
593 pkt_icmp = GNUNET_malloc (ntohs (pkt->shdr.size));
594 memcpy (pkt_icmp, pkt, ntohs (pkt->shdr.size));
595 GNUNET_SCHEDULER_add_now (&send_icmp4_response, pkt_icmp);
604 write_to_helper (void *buf, size_t len)
606 (void) GNUNET_DISK_file_write (helper_handle->fh_to_helper, buf, len);
610 schedule_helper_write (struct GNUNET_TIME_Relative time, void *cls)
612 if (GNUNET_SCHEDULER_NO_TASK != shs_task)
614 GNUNET_SCHEDULER_add_write_file (time, helper_handle->fh_to_helper,