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"
40 #include "gnunet-daemon-vpn.h"
41 #include "gnunet-vpn-checksum.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);
85 * @return the hash of the IP-Address if a mapping exists, NULL otherwise
88 address_mapping_exists(unsigned char addr[]) {
89 GNUNET_HashCode* key = GNUNET_malloc(sizeof(GNUNET_HashCode));
90 unsigned char* k = (unsigned char*)key;
91 memset(key, 0, sizeof(GNUNET_HashCode));
93 for (i = 0; i < 16; i++)
96 if (GNUNET_YES == GNUNET_CONTAINER_multihashmap_contains(hashmap, key))
106 send_icmp_response(void* cls, const struct GNUNET_SCHEDULER_TaskContext *tc) {
107 struct ip6_icmp* request = cls;
109 struct ip6_icmp* response = alloca(ntohs(request->shdr.size));
110 GNUNET_assert(response != NULL);
111 memset(response, 0, ntohs(request->shdr.size));
113 response->shdr.size = request->shdr.size;
114 response->shdr.type = htons(GNUNET_MESSAGE_TYPE_VPN_HELPER);
116 response->tun.flags = 0;
117 response->tun.type = htons(0x86dd);
119 response->ip6_hdr.hoplmt = 255;
120 response->ip6_hdr.paylgth = request->ip6_hdr.paylgth;
121 response->ip6_hdr.nxthdr = 0x3a;
122 response->ip6_hdr.version = 6;
123 memcpy(&response->ip6_hdr.sadr, &request->ip6_hdr.dadr, 16);
124 memcpy(&response->ip6_hdr.dadr, &request->ip6_hdr.sadr, 16);
126 response->icmp_hdr.code = 0;
127 response->icmp_hdr.type = 0x81;
129 /* Magic, more Magic! */
130 response->icmp_hdr.chks = request->icmp_hdr.chks - 0x1;
132 /* Copy the rest of the packet */
133 memcpy(response+1, request+1, ntohs(request->shdr.size) - sizeof(struct ip6_icmp));
135 write_to_helper(response, ntohs(response->shdr.size));
137 GNUNET_free(request);
141 * cls is the pointer to a GNUNET_MessageHeader that is
142 * followed by the service-descriptor and the packet that should be sent;
145 send_pkt_to_peer_notify_callback (void *cls, size_t size, void *buf)
147 struct GNUNET_MESH_Tunnel **tunnel = cls;
148 struct GNUNET_MessageHeader *hdr =
149 (struct GNUNET_MessageHeader *) (tunnel + 1);
150 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "send_pkt_to_peer_notify_callback: buf = %x; size = %u;\n", buf, size);
151 GNUNET_assert (size >= ntohs (hdr->size));
152 memcpy (buf, hdr, ntohs (hdr->size));
153 size = ntohs(hdr->size);
155 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Sent!\n");
160 port_in_ports (uint64_t ports, uint16_t port)
162 uint16_t *ps = (uint16_t *) & ports;
163 return ps[0] == port || ps[1] == port || ps[2] == port || ps[3] == port;
167 send_pkt_to_peer (void *cls,
168 const struct GNUNET_PeerIdentity *peer,
169 const struct GNUNET_TRANSPORT_ATS_Information *atsi)
171 if (peer == NULL) return;
172 struct GNUNET_MESH_Tunnel **tunnel = cls;
173 struct GNUNET_MessageHeader *hdr =
174 (struct GNUNET_MessageHeader *) (tunnel + 1);
175 GNUNET_MESH_notify_transmit_ready (*tunnel,
178 GNUNET_TIME_relative_divide(GNUNET_CONSTANTS_MAX_CORK_DELAY, 2),
179 (const struct GNUNET_PeerIdentity *)NULL,
181 send_pkt_to_peer_notify_callback,
186 * Create a new Address from an answer-packet
189 new_ip6addr(unsigned char* buf, const GNUNET_HashCode *peer, const GNUNET_HashCode *service_desc) { /* {{{ */
191 unsigned long long ipv6prefix;
192 GNUNET_assert(GNUNET_OK == GNUNET_CONFIGURATION_get_value_string(cfg, "vpn", "IPV6ADDR", &ipv6addr));
193 GNUNET_assert(GNUNET_OK == GNUNET_CONFIGURATION_get_value_number(cfg, "vpn", "IPV6PREFIX", &ipv6prefix));
194 GNUNET_assert(ipv6prefix < 127);
195 ipv6prefix = (ipv6prefix + 7)/8;
197 inet_pton (AF_INET6, ipv6addr, buf);
198 GNUNET_free(ipv6addr);
200 int peer_length = 16 - ipv6prefix - 6;
201 if (peer_length <= 0)
204 int service_length = 16 - ipv6prefix - peer_length;
205 if (service_length <= 0)
208 memcpy(buf+ipv6prefix, service_desc, service_length);
209 memcpy(buf+ipv6prefix+service_length, peer, peer_length);
214 * This gets scheduled with cls pointing to an answer_packet and does everything
215 * needed in order to send it to the helper.
217 * At the moment this means "inventing" and IPv6-Address for .gnunet-services and
218 * doing nothing for "real" services.
221 process_answer(void* cls, const struct GNUNET_SCHEDULER_TaskContext* tc) {
222 struct answer_packet* pkt = cls;
223 struct answer_packet_list* list;
225 /* This answer is about a .gnunet-service
227 * It contains an almost complete DNS-Response, we have to fill in the ip
228 * at the offset pkt->addroffset
231 if (pkt->subtype == GNUNET_DNS_ANSWER_TYPE_SERVICE)
233 pkt->subtype = GNUNET_DNS_ANSWER_TYPE_IP;
236 memset(&key, 0, sizeof(GNUNET_HashCode));
238 unsigned char* c = ((unsigned char*)pkt)+ntohs(pkt->addroffset);
239 unsigned char* k = (unsigned char*)&key;
240 new_ip6addr(c, &pkt->service_descr.peer, &pkt->service_descr.service_descriptor);
242 * Copy the newly generated ip-address to the key backwarts (as only the first part is hashed)
245 for (i = 0; i < 16; i++)
248 uint16_t namelen = strlen((char*)pkt->data+12)+1;
250 struct map_entry* value = GNUNET_malloc(sizeof(struct map_entry) + namelen);
251 char* name = (char*)(value +1);
253 value->namelen = namelen;
254 memcpy(name, pkt->data+12, namelen);
256 memcpy(&value->desc, &pkt->service_descr, sizeof(struct GNUNET_vpn_service_descriptor));
258 memset(value->additional_ports, 0, 8192);
261 GNUNET_CONTAINER_multihashmap_contains (hashmap, &key))
262 GNUNET_CONTAINER_multihashmap_put (hashmap, &key, value,
263 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY);
268 list = GNUNET_malloc(htons(pkt->hdr.size) + 2*sizeof(struct answer_packet_list*));
270 memcpy(&list->pkt, pkt, htons(pkt->hdr.size));
273 else if (pkt->subtype == GNUNET_DNS_ANSWER_TYPE_REV)
276 memset(&key, 0, sizeof key);
277 unsigned char* k = (unsigned char*)&key;
278 unsigned char* s = pkt->data+12;
280 /* Whoever designed the reverse IPv6-lookup is batshit insane */
281 for (i = 0; i < 16; i++)
283 unsigned char c1 = s[(4*i)+1];
284 unsigned char c2 = s[(4*i)+3];
288 k[i] = c1 - 87; /* 87 is the difference between 'a' and 10 */
290 k[i] += 16*(c2 - '0');
292 k[i] += 16*(c2 - 87);
295 struct map_entry* map_entry = GNUNET_CONTAINER_multihashmap_get(hashmap, &key);
296 uint16_t offset = ntohs(pkt->addroffset);
298 if (map_entry == NULL)
304 unsigned short namelen = htons(map_entry->namelen);
305 char* name = (char*)(map_entry + 1);
307 list = GNUNET_malloc(2*sizeof(struct answer_packet_list*) + offset + 2 + ntohs(namelen));
309 struct answer_packet* rpkt = &list->pkt;
311 /* The offset points to the first byte belonging to the address */
312 memcpy(rpkt, pkt, offset - 1);
314 rpkt->subtype = GNUNET_DNS_ANSWER_TYPE_IP;
315 rpkt->hdr.size = ntohs(offset + 2 + ntohs(namelen));
317 memcpy(((char*)rpkt)+offset, &namelen, 2);
318 memcpy(((char*)rpkt)+offset+2, name, ntohs(namelen));
321 else if (pkt->subtype == GNUNET_DNS_ANSWER_TYPE_IP)
323 list = GNUNET_malloc(htons(pkt->hdr.size) + 2*sizeof(struct answer_packet_list*));
324 memcpy(&list->pkt, pkt, htons(pkt->hdr.size));
335 GNUNET_CONTAINER_DLL_insert_after(answer_proc_head, answer_proc_tail, answer_proc_tail, list);
337 schedule_helper_write(GNUNET_TIME_UNIT_FOREVER_REL, NULL);
343 * Sets a bit active in a bitArray.
345 * @param bitArray memory area to set the bit in
346 * @param bitIdx which bit to set
349 setBit (char *bitArray, unsigned int bitIdx)
352 unsigned int targetBit;
354 arraySlot = bitIdx / 8;
355 targetBit = (1L << (bitIdx % 8));
356 bitArray[arraySlot] |= targetBit;
360 * Clears a bit from bitArray.
362 * @param bitArray memory area to set the bit in
363 * @param bitIdx which bit to unset
366 clearBit (char *bitArray, unsigned int bitIdx)
369 unsigned int targetBit;
372 targetBit = (1L << (bitIdx % 8));
373 bitArray[slot] = bitArray[slot] & (~targetBit);
377 * Checks if a bit is active in the bitArray
379 * @param bitArray memory area to set the bit in
380 * @param bitIdx which bit to test
381 * @return GNUNET_YES if the bit is set, GNUNET_NO if not.
384 testBit (char *bitArray, unsigned int bitIdx)
387 unsigned int targetBit;
390 targetBit = (1L << (bitIdx % 8));
391 if (bitArray[slot] & targetBit)
398 * @brief Add the port to the list of additional ports in the map_entry
400 * @param me the map_entry
401 * @param port the port in host-byte-order
404 add_additional_port (struct map_entry *me, uint16_t port)
406 setBit(me->additional_ports, port);
410 receive_udp_back (void *cls, struct GNUNET_MESH_Tunnel* tunnel,
412 const struct GNUNET_PeerIdentity *sender,
413 const struct GNUNET_MessageHeader *message,
414 const struct GNUNET_TRANSPORT_ATS_Information *atsi)
416 GNUNET_HashCode *desc = (GNUNET_HashCode *) (message + 1);
417 struct udp_pkt *pkt = (struct udp_pkt *) (desc + 1);
418 const struct GNUNET_PeerIdentity* other = GNUNET_MESH_get_peer(tunnel);
420 size_t size = sizeof(struct ip6_udp) + ntohs(pkt->len) - 1 - sizeof(struct udp_pkt);
422 struct ip6_udp* pkt6 = alloca(size);
424 GNUNET_assert(pkt6 != NULL);
426 new_ip6addr(pkt6->ip6_hdr.sadr, &other->hashPubKey, desc);
428 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Relaying calc:%d gnu:%d udp:%d bytes!\n", size, ntohs(message->size), ntohs(pkt->len));
430 pkt6->shdr.type = htons(GNUNET_MESSAGE_TYPE_VPN_HELPER);
431 pkt6->shdr.size = htons(size);
434 pkt6->tun.type = htons(0x86dd);
436 pkt6->ip6_hdr.version = 6;
437 pkt6->ip6_hdr.tclass_h = 0;
438 pkt6->ip6_hdr.tclass_l = 0;
439 pkt6->ip6_hdr.flowlbl = 0;
440 pkt6->ip6_hdr.paylgth = pkt->len;
441 pkt6->ip6_hdr.nxthdr = 0x11;
442 pkt6->ip6_hdr.hoplmt = 0xff;
446 GNUNET_assert(GNUNET_OK == GNUNET_CONFIGURATION_get_value_string(cfg, "vpn", "IPV6ADDR", &ipv6addr));
447 inet_pton (AF_INET6, ipv6addr, pkt6->ip6_hdr.dadr);
448 GNUNET_free(ipv6addr);
450 memcpy(&pkt6->udp_hdr, pkt, ntohs(pkt->len));
452 GNUNET_HashCode* key = address_mapping_exists(pkt6->ip6_hdr.sadr);
453 GNUNET_assert (key != NULL);
455 struct map_entry *me = GNUNET_CONTAINER_multihashmap_get(hashmap, key);
459 GNUNET_assert (me != NULL);
460 GNUNET_assert (me->desc.service_type & htonl(GNUNET_DNS_SERVICE_TYPE_UDP));
461 if (!port_in_ports(me->desc.ports, pkt6->udp_hdr.spt) &&
462 !testBit(me->additional_ports, ntohs(pkt6->udp_hdr.spt))) {
463 add_additional_port(me, ntohs(pkt6->udp_hdr.spt));
466 pkt6->udp_hdr.crc = 0;
468 sum = calculate_checksum_update(sum, (uint16_t*)&pkt6->ip6_hdr.sadr, 16);
469 sum = calculate_checksum_update(sum, (uint16_t*)&pkt6->ip6_hdr.dadr, 16);
470 uint32_t tmp = (pkt6->udp_hdr.len & 0xffff);
471 sum = calculate_checksum_update(sum, (uint16_t*)&tmp, 4);
472 tmp = htons(((pkt6->ip6_hdr.nxthdr & 0x00ff)));
473 sum = calculate_checksum_update(sum, (uint16_t*)&tmp, 4);
475 sum = calculate_checksum_update(sum, (uint16_t*)&pkt6->udp_hdr, ntohs(pkt->len));
476 pkt6->udp_hdr.crc = calculate_checksum_end(sum);
478 write_to_helper(pkt6, size);
484 receive_tcp_back (void *cls, struct GNUNET_MESH_Tunnel* tunnel,
486 const struct GNUNET_PeerIdentity *sender,
487 const struct GNUNET_MessageHeader *message,
488 const struct GNUNET_TRANSPORT_ATS_Information *atsi)
490 GNUNET_HashCode *desc = (GNUNET_HashCode *) (message + 1);
491 struct tcp_pkt *pkt = (struct tcp_pkt *) (desc + 1);
492 const struct GNUNET_PeerIdentity* other = GNUNET_MESH_get_peer(tunnel);
494 size_t pktlen = ntohs(message->size) - sizeof(struct GNUNET_MessageHeader) - sizeof(GNUNET_HashCode);
495 size_t size = pktlen + sizeof(struct ip6_tcp) - 1;
497 struct ip6_tcp* pkt6 = alloca(size);
499 GNUNET_assert(pkt6 != NULL);
501 new_ip6addr(pkt6->ip6_hdr.sadr, &other->hashPubKey, desc);
503 pkt6->shdr.type = htons(GNUNET_MESSAGE_TYPE_VPN_HELPER);
504 pkt6->shdr.size = htons(size);
507 pkt6->tun.type = htons(0x86dd);
509 pkt6->ip6_hdr.version = 6;
510 pkt6->ip6_hdr.tclass_h = 0;
511 pkt6->ip6_hdr.tclass_l = 0;
512 pkt6->ip6_hdr.flowlbl = 0;
513 pkt6->ip6_hdr.paylgth = htons(pktlen);
514 pkt6->ip6_hdr.nxthdr = 0x06;
515 pkt6->ip6_hdr.hoplmt = 0xff;
519 GNUNET_assert(GNUNET_OK == GNUNET_CONFIGURATION_get_value_string(cfg, "vpn", "IPV6ADDR", &ipv6addr));
520 inet_pton (AF_INET6, ipv6addr, pkt6->ip6_hdr.dadr);
521 GNUNET_free(ipv6addr);
523 memcpy(&pkt6->tcp_hdr, pkt, pktlen);
525 GNUNET_HashCode* key = address_mapping_exists(pkt6->ip6_hdr.sadr);
526 GNUNET_assert (key != NULL);
528 struct map_entry *me = GNUNET_CONTAINER_multihashmap_get(hashmap, key);
532 GNUNET_assert (me != NULL);
533 GNUNET_assert (me->desc.service_type & htonl(GNUNET_DNS_SERVICE_TYPE_TCP));
535 pkt6->tcp_hdr.crc = 0;
539 calculate_checksum_update (sum, (uint16_t *) & pkt6->ip6_hdr.sadr, 16);
541 calculate_checksum_update (sum, (uint16_t *) & pkt6->ip6_hdr.dadr, 16);
543 sum = calculate_checksum_update (sum, (uint16_t *) & tmp, 4);
544 tmp = htonl (((pkt6->ip6_hdr.nxthdr & 0x000000ff)));
545 sum = calculate_checksum_update (sum, (uint16_t *) & tmp, 4);
548 calculate_checksum_update (sum, (uint16_t *) & pkt6->tcp_hdr,
549 ntohs (pkt6->ip6_hdr.paylgth));
550 pkt6->tcp_hdr.crc = calculate_checksum_end (sum);
552 write_to_helper(pkt6, size);
557 void init_mesh (void* cls, struct GNUNET_MESH_Handle* server, const struct GNUNET_PeerIdentity* my_identity, const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *pubkey) {
558 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Connected to MESH, I am %x\n", *((unsigned long*)my_identity));
561 void connect_mesh (void* cls, const struct GNUNET_PeerIdentity* peer, const struct GNUNET_TRANSPORT_ATS_Information *atsi) {
562 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Connected to peer %x\n", *((unsigned long*)peer));
566 * Main function that will be run by the scheduler.
569 * @param args remaining command-line arguments
570 * @param cfgfile name of the configuration file used (for saving, can be NULL!)
571 * @param cfg_ configuration
577 const struct GNUNET_CONFIGURATION_Handle *cfg_)
579 const static struct GNUNET_MESH_MessageHandler handlers[] = {
580 {receive_udp_back, GNUNET_MESSAGE_TYPE_SERVICE_UDP_BACK, 0},
581 {receive_tcp_back, GNUNET_MESSAGE_TYPE_SERVICE_TCP_BACK, 0},
584 mesh_handle = GNUNET_MESH_connect(cfg_,
590 hashmap = GNUNET_CONTAINER_multihashmap_create(65536);
591 udp_connections = GNUNET_CONTAINER_multihashmap_create(65536);
592 GNUNET_SCHEDULER_TaskIdentifier conn_task = GNUNET_SCHEDULER_add_now (connect_to_service_dns, NULL);
593 GNUNET_SCHEDULER_add_after (conn_task, start_helper_and_schedule, NULL);
594 GNUNET_SCHEDULER_add_delayed(GNUNET_TIME_UNIT_FOREVER_REL, &cleanup, cls);
598 * The main function to obtain template from gnunetd.
600 * @param argc number of arguments from the command line
601 * @param argv command line arguments
602 * @return 0 ok, 1 on error
605 main (int argc, char *const *argv) {
606 static const struct GNUNET_GETOPT_CommandLineOption options[] = {
607 GNUNET_GETOPT_OPTION_END
611 GNUNET_PROGRAM_run (argc,
614 gettext_noop ("help text"),
615 options, &run, NULL)) ? ret : 1;
618 /* end of gnunet-daemon-vpn.c */