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 Toelke
27 #include "gnunet_getopt_lib.h"
28 #include "gnunet_program_lib.h"
29 #include "gnunet-vpn-packet.h"
30 #include "gnunet-vpn-pretty-print.h"
31 #include "gnunet_common.h"
32 #include "gnunet_protocols.h"
33 #include <gnunet_mesh_service.h>
34 #include "gnunet_client_lib.h"
35 #include "gnunet_container_lib.h"
36 #include "gnunet_constants.h"
37 #include <block_dns.h>
38 #include "gnunet-daemon-vpn-helper.h"
39 #include "gnunet-daemon-vpn-dns.h"
41 #include "gnunet-daemon-vpn.h"
43 const struct GNUNET_CONFIGURATION_Handle *cfg;
44 struct GNUNET_MESH_Handle *mesh_handle;
45 struct GNUNET_CONTAINER_MultiHashMap* hashmap;
53 * This hashmap contains the mapping from peer, service-descriptor,
54 * source-port and destination-port to a socket
56 static struct GNUNET_CONTAINER_MultiHashMap *udp_connections;
59 * Function scheduled as very last function, cleans up after us
63 cleanup(void* cls, const struct GNUNET_SCHEDULER_TaskContext* tskctx) {
64 GNUNET_assert (0 != (tskctx->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN));
67 cleanup_helper(helper_handle);
69 /* close the connection to the service-dns */
70 if (dns_connection != NULL)
72 GNUNET_CLIENT_disconnect (dns_connection, GNUNET_NO);
73 dns_connection = NULL;
76 if (mesh_handle != NULL)
78 GNUNET_MESH_disconnect(mesh_handle);
84 static uint32_t calculate_checksum_update(uint32_t sum, uint16_t *hdr, short len) {
85 for(; len >= 2; len -= 2)
88 sum += *((unsigned char*)hdr);
92 static uint16_t calculate_checksum_end(uint32_t sum) {
94 sum = (sum >> 16) + (sum & 0xFFFF);
100 * Calculate the checksum of an IPv4-Header
103 calculate_ip_checksum(uint16_t* hdr, short len) {
104 uint32_t sum = calculate_checksum_update(0, hdr, len);
105 return calculate_checksum_end(sum);
109 * @return the hash of the IP-Address if a mapping exists, NULL otherwise
112 address_mapping_exists(unsigned char addr[]) {
113 GNUNET_HashCode* key = GNUNET_malloc(sizeof(GNUNET_HashCode));
114 unsigned char* k = (unsigned char*)key;
115 memset(key, 0, sizeof(GNUNET_HashCode));
117 for (i = 0; i < 16; i++)
120 if (GNUNET_YES == GNUNET_CONTAINER_multihashmap_contains(hashmap, key))
130 send_icmp_response(void* cls, const struct GNUNET_SCHEDULER_TaskContext *tc) {
131 struct ip6_icmp* request = cls;
133 struct ip6_icmp* response = alloca(ntohs(request->shdr.size));
134 GNUNET_assert(response != NULL);
135 memset(response, 0, ntohs(request->shdr.size));
137 response->shdr.size = request->shdr.size;
138 response->shdr.type = htons(GNUNET_MESSAGE_TYPE_VPN_HELPER);
140 response->tun.flags = 0;
141 response->tun.type = htons(0x86dd);
143 response->ip6_hdr.hoplmt = 255;
144 response->ip6_hdr.paylgth = request->ip6_hdr.paylgth;
145 response->ip6_hdr.nxthdr = 0x3a;
146 response->ip6_hdr.version = 6;
147 memcpy(&response->ip6_hdr.sadr, &request->ip6_hdr.dadr, 16);
148 memcpy(&response->ip6_hdr.dadr, &request->ip6_hdr.sadr, 16);
150 response->icmp_hdr.code = 0;
151 response->icmp_hdr.type = 0x81;
153 /* Magic, more Magic! */
154 response->icmp_hdr.chks = request->icmp_hdr.chks - 0x1;
156 /* Copy the rest of the packet */
157 memcpy(response+1, request+1, ntohs(request->shdr.size) - sizeof(struct ip6_icmp));
159 write_to_helper(response, ntohs(response->shdr.size));
161 GNUNET_free(request);
165 * cls is the pointer to a GNUNET_MessageHeader that is
166 * followed by the service-descriptor and the udp-packet that should be sent;
169 send_udp_to_peer_notify_callback (void *cls, size_t size, void *buf)
171 struct GNUNET_MESH_Tunnel **tunnel = cls;
172 struct GNUNET_MessageHeader *hdr =
173 (struct GNUNET_MessageHeader *) (tunnel + 1);
174 GNUNET_HashCode *hc = (GNUNET_HashCode *) (hdr + 1);
175 struct udp_pkt *udp = (struct udp_pkt *) (hc + 1);
176 hdr->size = htons (sizeof (struct GNUNET_MessageHeader) +
177 sizeof (GNUNET_HashCode) + ntohs (udp->len));
178 hdr->type = ntohs (GNUNET_MESSAGE_TYPE_SERVICE_UDP);
179 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "send_udp_to_peer_notify_callback: buf = %x; size = %u;\n", buf, size);
180 GNUNET_assert (size >= ntohs (hdr->size));
181 memcpy (buf, hdr, ntohs (hdr->size));
182 size = ntohs(hdr->size);
184 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Sent!\n");
189 port_in_ports (uint64_t ports, uint16_t port)
191 uint16_t *ps = (uint16_t *) & ports;
192 return ps[0] == port || ps[1] == port || ps[2] == port || ps[3] == port;
196 send_udp_to_peer (void *cls,
197 const struct GNUNET_PeerIdentity *peer,
198 const struct GNUNET_TRANSPORT_ATS_Information *atsi)
200 if (peer == NULL) return;
201 struct GNUNET_MESH_Tunnel **tunnel = cls;
202 struct GNUNET_MessageHeader *hdr =
203 (struct GNUNET_MessageHeader *) (tunnel + 1);
204 GNUNET_HashCode *hc = (GNUNET_HashCode *) (hdr + 1);
205 struct udp_pkt *udp = (struct udp_pkt *) (hc + 1);
206 GNUNET_MESH_notify_transmit_ready (*tunnel,
209 GNUNET_TIME_relative_divide(GNUNET_CONSTANTS_MAX_CORK_DELAY, 2),
211 (struct GNUNET_MessageHeader) +
212 sizeof (GNUNET_HashCode) +
214 send_udp_to_peer_notify_callback,
219 * Create a new Address from an answer-packet
222 new_ip6addr(unsigned char* buf, const GNUNET_HashCode *peer, const GNUNET_HashCode *service_desc) { /* {{{ */
224 unsigned long long ipv6prefix;
225 GNUNET_assert(GNUNET_OK == GNUNET_CONFIGURATION_get_value_string(cfg, "vpn", "IPV6ADDR", &ipv6addr));
226 GNUNET_assert(GNUNET_OK == GNUNET_CONFIGURATION_get_value_number(cfg, "vpn", "IPV6PREFIX", &ipv6prefix));
227 GNUNET_assert(ipv6prefix < 127);
228 ipv6prefix = (ipv6prefix + 7)/8;
230 inet_pton (AF_INET6, ipv6addr, buf);
231 GNUNET_free(ipv6addr);
233 int peer_length = 16 - ipv6prefix - 6;
234 if (peer_length <= 0)
237 int service_length = 16 - ipv6prefix - peer_length;
238 if (service_length <= 0)
241 memcpy(buf+ipv6prefix, service_desc, service_length);
242 memcpy(buf+ipv6prefix+service_length, peer, peer_length);
247 * This gets scheduled with cls pointing to an answer_packet and does everything
248 * needed in order to send it to the helper.
250 * At the moment this means "inventing" and IPv6-Address for .gnunet-services and
251 * doing nothing for "real" services.
254 process_answer(void* cls, const struct GNUNET_SCHEDULER_TaskContext* tc) {
255 struct answer_packet* pkt = cls;
256 struct answer_packet_list* list;
258 /* This answer is about a .gnunet-service
260 * It contains an almost complete DNS-Response, we have to fill in the ip
261 * at the offset pkt->addroffset
264 if (pkt->subtype == GNUNET_DNS_ANSWER_TYPE_SERVICE)
266 pkt->subtype = GNUNET_DNS_ANSWER_TYPE_IP;
269 memset(&key, 0, sizeof(GNUNET_HashCode));
271 unsigned char* c = ((unsigned char*)pkt)+ntohs(pkt->addroffset);
272 unsigned char* k = (unsigned char*)&key;
273 new_ip6addr(c, &pkt->service_descr.peer, &pkt->service_descr.service_descriptor);
275 * Copy the newly generated ip-address to the key backwarts (as only the first part is hashed)
278 for (i = 0; i < 16; i++)
281 uint16_t namelen = strlen((char*)pkt->data+12)+1;
283 struct map_entry* value = GNUNET_malloc(sizeof(struct map_entry) + namelen);
284 char* name = (char*)(value +1);
286 value->namelen = namelen;
287 memcpy(name, pkt->data+12, namelen);
289 memcpy(&value->desc, &pkt->service_descr, sizeof(struct GNUNET_vpn_service_descriptor));
291 value->additional_ports = 0;
293 if (GNUNET_OK != GNUNET_CONTAINER_multihashmap_put(hashmap,
296 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY))
298 GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "Could not store to hashmap\n");
302 list = GNUNET_malloc(htons(pkt->hdr.size) + 2*sizeof(struct answer_packet_list*));
304 memcpy(&list->pkt, pkt, htons(pkt->hdr.size));
307 else if (pkt->subtype == GNUNET_DNS_ANSWER_TYPE_REV)
310 memset(&key, 0, sizeof key);
311 unsigned char* k = (unsigned char*)&key;
312 unsigned char* s = pkt->data+12;
314 /* Whoever designed the reverse IPv6-lookup is batshit insane */
315 for (i = 0; i < 16; i++)
317 unsigned char c1 = s[(4*i)+1];
318 unsigned char c2 = s[(4*i)+3];
322 k[i] = c1 - 87; /* 87 is the difference between 'a' and 10 */
324 k[i] += 16*(c2 - '0');
326 k[i] += 16*(c2 - 87);
329 struct map_entry* map_entry = GNUNET_CONTAINER_multihashmap_get(hashmap, &key);
330 uint16_t offset = ntohs(pkt->addroffset);
332 if (map_entry == NULL)
338 unsigned short namelen = htons(map_entry->namelen);
339 char* name = (char*)(map_entry + 1);
341 list = GNUNET_malloc(2*sizeof(struct answer_packet_list*) + offset + 2 + ntohs(namelen));
343 struct answer_packet* rpkt = &list->pkt;
345 /* The offset points to the first byte belonging to the address */
346 memcpy(rpkt, pkt, offset - 1);
348 rpkt->subtype = GNUNET_DNS_ANSWER_TYPE_IP;
349 rpkt->hdr.size = ntohs(offset + 2 + ntohs(namelen));
351 memcpy(((char*)rpkt)+offset, &namelen, 2);
352 memcpy(((char*)rpkt)+offset+2, name, ntohs(namelen));
355 else if (pkt->subtype == GNUNET_DNS_ANSWER_TYPE_IP)
357 list = GNUNET_malloc(htons(pkt->hdr.size) + 2*sizeof(struct answer_packet_list*));
358 memcpy(&list->pkt, pkt, htons(pkt->hdr.size));
369 GNUNET_CONTAINER_DLL_insert_after(answer_proc_head, answer_proc_tail, answer_proc_tail, list);
371 schedule_helper_write(GNUNET_TIME_UNIT_FOREVER_REL, NULL);
377 add_additional_port (struct map_entry *me, uint16_t port)
379 uint16_t *ps = (uint16_t *) & me->additional_ports;
381 for (i = 0; i < 4; i++)
392 receive_udp_back (void *cls, struct GNUNET_MESH_Tunnel* tunnel,
394 const struct GNUNET_MessageHeader *message,
395 const struct GNUNET_TRANSPORT_ATS_Information *atsi)
397 GNUNET_HashCode *desc = (GNUNET_HashCode *) (message + 1);
398 struct udp_pkt *pkt = (struct udp_pkt *) (desc + 1);
399 const struct GNUNET_PeerIdentity* other = GNUNET_MESH_get_peer(tunnel);
401 size_t size = sizeof(struct ip6_udp) + ntohs(pkt->len) - 1 - sizeof(struct udp_pkt);
403 struct ip6_udp* pkt6 = alloca(size);
405 GNUNET_assert(pkt6 != NULL);
407 new_ip6addr(pkt6->ip6_hdr.sadr, &other->hashPubKey, desc);
409 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Relaying calc:%d gnu:%d udp:%d bytes!\n", size, ntohs(message->size), ntohs(pkt->len));
411 pkt6->shdr.type = htons(GNUNET_MESSAGE_TYPE_VPN_HELPER);
412 pkt6->shdr.size = htons(size);
415 pkt6->tun.type = htons(0x86dd);
417 pkt6->ip6_hdr.version = 6;
418 pkt6->ip6_hdr.tclass_h = 0;
419 pkt6->ip6_hdr.tclass_l = 0;
420 pkt6->ip6_hdr.flowlbl = 0;
421 pkt6->ip6_hdr.paylgth = pkt->len;
422 pkt6->ip6_hdr.nxthdr = 0x11;
423 pkt6->ip6_hdr.hoplmt = 0xff;
427 GNUNET_assert(GNUNET_OK == GNUNET_CONFIGURATION_get_value_string(cfg, "vpn", "IPV6ADDR", &ipv6addr));
428 inet_pton (AF_INET6, ipv6addr, pkt6->ip6_hdr.dadr);
429 GNUNET_free(ipv6addr);
431 memcpy(&pkt6->udp_hdr, pkt, ntohs(pkt->len));
433 GNUNET_HashCode* key = address_mapping_exists(pkt6->ip6_hdr.sadr);
434 GNUNET_assert (key != NULL);
436 struct map_entry *me = GNUNET_CONTAINER_multihashmap_get(hashmap, key);
440 GNUNET_assert (me != NULL);
441 GNUNET_assert (me->desc.service_type & htonl(GNUNET_DNS_SERVICE_TYPE_UDP));
442 if (!port_in_ports(me->desc.ports, pkt6->udp_hdr.spt) ||
443 !port_in_ports(me->additional_ports, pkt6->udp_hdr.spt)) {
444 add_additional_port(me, pkt6->udp_hdr.spt);
447 pkt6->udp_hdr.crc = 0;
449 sum = calculate_checksum_update(sum, (uint16_t*)&pkt6->ip6_hdr.sadr, 16);
450 sum = calculate_checksum_update(sum, (uint16_t*)&pkt6->ip6_hdr.dadr, 16);
451 uint32_t tmp = (pkt6->udp_hdr.len & 0xffff);
452 sum = calculate_checksum_update(sum, (uint16_t*)&tmp, 4);
453 tmp = htons(((pkt6->ip6_hdr.nxthdr & 0x00ff)));
454 sum = calculate_checksum_update(sum, (uint16_t*)&tmp, 4);
456 sum = calculate_checksum_update(sum, (uint16_t*)&pkt6->udp_hdr, ntohs(pkt->len));
457 pkt6->udp_hdr.crc = calculate_checksum_end(sum);
459 write_to_helper(pkt6, size);
464 void init_mesh (void* cls, struct GNUNET_MESH_Handle* server, const struct GNUNET_PeerIdentity* my_identity, const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *pubkey) {
465 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Connected to MESH, I am %x\n", *((unsigned long*)my_identity));
468 void connect_mesh (void* cls, const struct GNUNET_PeerIdentity* peer, const struct GNUNET_TRANSPORT_ATS_Information *atsi) {
469 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Connected to peer %x\n", *((unsigned long*)peer));
473 * Main function that will be run by the scheduler.
476 * @param args remaining command-line arguments
477 * @param cfgfile name of the configuration file used (for saving, can be NULL!)
478 * @param cfg_ configuration
484 const struct GNUNET_CONFIGURATION_Handle *cfg_)
486 const static struct GNUNET_MESH_MessageHandler handlers[] = {
487 {receive_udp_back, GNUNET_MESSAGE_TYPE_SERVICE_UDP_BACK, 0},
490 mesh_handle = GNUNET_MESH_connect(cfg_,
496 hashmap = GNUNET_CONTAINER_multihashmap_create(65536);
497 udp_connections = GNUNET_CONTAINER_multihashmap_create(65536);
498 GNUNET_SCHEDULER_add_now (connect_to_service_dns, NULL);
499 GNUNET_SCHEDULER_add_now (start_helper_and_schedule, NULL);
500 GNUNET_SCHEDULER_add_delayed(GNUNET_TIME_UNIT_FOREVER_REL, &cleanup, cls);
504 * The main function to obtain template from gnunetd.
506 * @param argc number of arguments from the command line
507 * @param argv command line arguments
508 * @return 0 ok, 1 on error
511 main (int argc, char *const *argv) {
512 static const struct GNUNET_GETOPT_CommandLineOption options[] = {
513 GNUNET_GETOPT_OPTION_END
517 GNUNET_PROGRAM_run (argc,
520 gettext_noop ("help text"),
521 options, &run, NULL)) ? ret : 1;
524 /* end of gnunet-daemon-vpn.c */