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"
49 * This hashmap contains the mapping from peer, service-descriptor,
50 * source-port and destination-port to a socket
52 static struct GNUNET_CONTAINER_MultiHashMap *udp_connections;
55 * Function scheduled as very last function, cleans up after us
59 cleanup(void* cls, const struct GNUNET_SCHEDULER_TaskContext* tskctx) {
60 GNUNET_assert (0 != (tskctx->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN));
63 cleanup_helper(helper_handle);
65 /* close the connection to the service-dns */
66 if (dns_connection != NULL)
68 GNUNET_CLIENT_disconnect (dns_connection, GNUNET_NO);
69 dns_connection = NULL;
72 if (mesh_handle != NULL)
74 GNUNET_MESH_disconnect(mesh_handle);
80 static uint32_t calculate_checksum_update(uint32_t sum, uint16_t *hdr, short len) {
81 for(; len >= 2; len -= 2)
84 sum += *((unsigned char*)hdr);
88 static uint16_t calculate_checksum_end(uint32_t sum) {
90 sum = (sum >> 16) + (sum & 0xFFFF);
96 * Calculate the checksum of an IPv4-Header
99 calculate_ip_checksum(uint16_t* hdr, short len) {
100 uint32_t sum = calculate_checksum_update(0, hdr, len);
101 return calculate_checksum_end(sum);
105 * @return the hash of the IP-Address if a mapping exists, NULL otherwise
108 address_mapping_exists(unsigned char addr[]) {
109 GNUNET_HashCode* key = GNUNET_malloc(sizeof(GNUNET_HashCode));
110 unsigned char* k = (unsigned char*)key;
111 memset(key, 0, sizeof(GNUNET_HashCode));
113 for (i = 0; i < 16; i++)
116 if (GNUNET_YES == GNUNET_CONTAINER_multihashmap_contains(hashmap, key))
126 send_icmp_response(void* cls, const struct GNUNET_SCHEDULER_TaskContext *tc) {
127 struct ip6_icmp* request = cls;
129 struct ip6_icmp* response = alloca(ntohs(request->shdr.size));
130 GNUNET_assert(response != NULL);
131 memset(response, 0, ntohs(request->shdr.size));
133 response->shdr.size = request->shdr.size;
134 response->shdr.type = htons(GNUNET_MESSAGE_TYPE_VPN_HELPER);
136 response->tun.flags = 0;
137 response->tun.type = htons(0x86dd);
139 response->ip6_hdr.hoplmt = 255;
140 response->ip6_hdr.paylgth = request->ip6_hdr.paylgth;
141 response->ip6_hdr.nxthdr = 0x3a;
142 response->ip6_hdr.version = 6;
143 memcpy(&response->ip6_hdr.sadr, &request->ip6_hdr.dadr, 16);
144 memcpy(&response->ip6_hdr.dadr, &request->ip6_hdr.sadr, 16);
146 response->icmp_hdr.code = 0;
147 response->icmp_hdr.type = 0x81;
149 /* Magic, more Magic! */
150 response->icmp_hdr.chks = request->icmp_hdr.chks - 0x1;
152 /* Copy the rest of the packet */
153 memcpy(response+1, request+1, ntohs(request->shdr.size) - sizeof(struct ip6_icmp));
155 write_to_helper(response, ntohs(response->shdr.size));
157 GNUNET_free(request);
161 * cls is the pointer to a GNUNET_MessageHeader that is
162 * followed by the service-descriptor and the udp-packet that should be sent;
165 send_udp_to_peer_notify_callback (void *cls, size_t size, void *buf)
167 struct GNUNET_MESH_Tunnel **tunnel = cls;
168 struct GNUNET_MessageHeader *hdr =
169 (struct GNUNET_MessageHeader *) (tunnel + 1);
170 GNUNET_HashCode *hc = (GNUNET_HashCode *) (hdr + 1);
171 struct udp_pkt *udp = (struct udp_pkt *) (hc + 1);
172 hdr->size = htons (sizeof (struct GNUNET_MessageHeader) +
173 sizeof (GNUNET_HashCode) + ntohs (udp->len));
174 hdr->type = ntohs (GNUNET_MESSAGE_TYPE_SERVICE_UDP);
175 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "send_udp_to_peer_notify_callback: buf = %x; size = %u;\n", buf, size);
176 GNUNET_assert (size >= ntohs (hdr->size));
177 memcpy (buf, hdr, ntohs (hdr->size));
178 size = ntohs(hdr->size);
180 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Sent!\n");
185 port_in_ports (uint64_t ports, uint16_t port)
187 uint16_t *ps = (uint16_t *) & ports;
188 return ps[0] == port || ps[1] == port || ps[2] == port || ps[3] == port;
192 send_udp_to_peer (void *cls,
193 const struct GNUNET_PeerIdentity *peer,
194 const struct GNUNET_TRANSPORT_ATS_Information *atsi)
196 if (peer == NULL) return;
197 struct GNUNET_MESH_Tunnel **tunnel = cls;
198 struct GNUNET_MessageHeader *hdr =
199 (struct GNUNET_MessageHeader *) (tunnel + 1);
200 GNUNET_HashCode *hc = (GNUNET_HashCode *) (hdr + 1);
201 struct udp_pkt *udp = (struct udp_pkt *) (hc + 1);
202 GNUNET_MESH_notify_transmit_ready (*tunnel,
205 GNUNET_TIME_relative_divide(GNUNET_CONSTANTS_MAX_CORK_DELAY, 2),
207 (struct GNUNET_MessageHeader) +
208 sizeof (GNUNET_HashCode) +
210 send_udp_to_peer_notify_callback,
215 * Create a new Address from an answer-packet
218 new_ip6addr(char* buf, const GNUNET_HashCode *peer, const GNUNET_HashCode *service_desc) { /* {{{ */
219 memcpy(buf+14, (int[]){htons(0x3412)}, 2);
220 memcpy(buf+8, service_desc, 6);
221 memcpy(buf, peer, 8);
226 * This gets scheduled with cls pointing to an answer_packet and does everything
227 * needed in order to send it to the helper.
229 * At the moment this means "inventing" and IPv6-Address for .gnunet-services and
230 * doing nothing for "real" services.
233 process_answer(void* cls, const struct GNUNET_SCHEDULER_TaskContext* tc) {
234 struct answer_packet* pkt = cls;
235 struct answer_packet_list* list;
237 /* This answer is about a .gnunet-service
239 * It contains an almost complete DNS-Response, we have to fill in the ip
240 * at the offset pkt->addroffset
243 if (pkt->subtype == GNUNET_DNS_ANSWER_TYPE_SERVICE)
245 pkt->subtype = GNUNET_DNS_ANSWER_TYPE_IP;
248 memset(&key, 0, sizeof(GNUNET_HashCode));
249 new_ip6addr((char*)&key, &pkt->service_descr.peer, &pkt->service_descr.service_descriptor);
251 uint16_t namelen = strlen((char*)pkt->data+12)+1;
253 struct map_entry* value = GNUNET_malloc(sizeof(struct map_entry) + namelen);
254 char* name = (char*)(value +1);
256 value->namelen = namelen;
257 memcpy(name, pkt->data+12, namelen);
259 memcpy(&value->desc, &pkt->service_descr, sizeof(struct GNUNET_vpn_service_descriptor));
261 value->additional_ports = 0;
263 if (GNUNET_OK != GNUNET_CONTAINER_multihashmap_put(hashmap,
266 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY))
268 GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "Could not store to hashmap\n");
272 * Copy the newly generated backward ip-address to the packet
274 char* c = ((char*)pkt)+ntohs(pkt->addroffset);
275 char* k = (char*)&key;
277 for (i = 0; i < 16; i++)
280 list = GNUNET_malloc(htons(pkt->hdr.size) + 2*sizeof(struct answer_packet_list*));
282 memcpy(&list->pkt, pkt, htons(pkt->hdr.size));
285 else if (pkt->subtype == GNUNET_DNS_ANSWER_TYPE_REV)
288 memset(&key, 0, sizeof key);
289 unsigned char* k = (unsigned char*)&key;
290 unsigned char* s = pkt->data+12;
292 /* Whoever designed the reverse IPv6-lookup is batshit insane */
293 for (i = 0; i < 16; i++)
295 unsigned char c1 = s[(4*i)+1];
296 unsigned char c2 = s[(4*i)+3];
300 k[i] = c1 - 87; /* 87 is the difference between 'a' and 10 */
302 k[i] += 16*(c2 - '0');
304 k[i] += 16*(c2 - 87);
307 struct map_entry* map_entry = GNUNET_CONTAINER_multihashmap_get(hashmap, &key);
308 uint16_t offset = ntohs(pkt->addroffset);
310 if (map_entry == NULL)
316 unsigned short namelen = htons(map_entry->namelen);
317 char* name = (char*)(map_entry + 1);
319 list = GNUNET_malloc(2*sizeof(struct answer_packet_list*) + offset + 2 + ntohs(namelen));
321 struct answer_packet* rpkt = &list->pkt;
323 /* The offset points to the first byte belonging to the address */
324 memcpy(rpkt, pkt, offset - 1);
326 rpkt->subtype = GNUNET_DNS_ANSWER_TYPE_IP;
327 rpkt->hdr.size = ntohs(offset + 2 + ntohs(namelen));
329 memcpy(((char*)rpkt)+offset, &namelen, 2);
330 memcpy(((char*)rpkt)+offset+2, name, ntohs(namelen));
333 else if (pkt->subtype == GNUNET_DNS_ANSWER_TYPE_IP)
335 list = GNUNET_malloc(htons(pkt->hdr.size) + 2*sizeof(struct answer_packet_list*));
336 memcpy(&list->pkt, pkt, htons(pkt->hdr.size));
347 GNUNET_CONTAINER_DLL_insert_after(answer_proc_head, answer_proc_tail, answer_proc_tail, list);
349 schedule_helper_write(GNUNET_TIME_UNIT_FOREVER_REL, NULL);
355 add_additional_port (struct map_entry *me, uint16_t port)
357 uint16_t *ps = (uint16_t *) & me->additional_ports;
359 for (i = 0; i < 4; i++)
370 receive_udp_back (void *cls, struct GNUNET_MESH_Tunnel* tunnel,
372 const struct GNUNET_MessageHeader *message,
373 const struct GNUNET_TRANSPORT_ATS_Information *atsi)
375 GNUNET_HashCode *desc = (GNUNET_HashCode *) (message + 1);
376 struct udp_pkt *pkt = (struct udp_pkt *) (desc + 1);
378 const struct GNUNET_PeerIdentity* other = GNUNET_MESH_get_peer(tunnel);
380 new_ip6addr(addr, &other->hashPubKey, desc);
382 size_t size = sizeof(struct ip6_udp) + ntohs(pkt->len) - 1 - sizeof(struct udp_pkt);
384 struct ip6_udp* pkt6 = alloca(size);
386 GNUNET_assert(pkt6 != NULL);
388 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Relaying calc:%d gnu:%d udp:%d bytes!\n", size, ntohs(message->size), ntohs(pkt->len));
390 pkt6->shdr.type = htons(GNUNET_MESSAGE_TYPE_VPN_HELPER);
391 pkt6->shdr.size = htons(size);
394 pkt6->tun.type = htons(0x86dd);
396 pkt6->ip6_hdr.version = 6;
397 pkt6->ip6_hdr.tclass_h = 0;
398 pkt6->ip6_hdr.tclass_l = 0;
399 pkt6->ip6_hdr.flowlbl = 0;
400 pkt6->ip6_hdr.paylgth = pkt->len;
401 pkt6->ip6_hdr.nxthdr = 0x11;
402 pkt6->ip6_hdr.hoplmt = 0xff;
405 for (i = 0; i < 16; i++)
406 pkt6->ip6_hdr.sadr[15-i] = addr[i];
410 GNUNET_assert(GNUNET_SYSERR == GNUNET_CONFIGURATION_get_value_string(cfg, "vpn", "IPV6ADDR", &ipv6addr));
411 inet_pton (AF_INET6, ipv6addr, pkt6->ip6_hdr.dadr);
413 memcpy(&pkt6->udp_hdr, pkt, ntohs(pkt->len));
415 GNUNET_HashCode* key = address_mapping_exists(pkt6->ip6_hdr.sadr);
416 GNUNET_assert (key != NULL);
418 struct map_entry *me = GNUNET_CONTAINER_multihashmap_get(hashmap, key);
422 GNUNET_assert (me != NULL);
423 GNUNET_assert (me->desc.service_type & htonl(GNUNET_DNS_SERVICE_TYPE_UDP));
424 if (!port_in_ports(me->desc.ports, pkt6->udp_hdr.spt) ||
425 !port_in_ports(me->additional_ports, pkt6->udp_hdr.spt)) {
426 add_additional_port(me, pkt6->udp_hdr.spt);
429 pkt6->udp_hdr.crc = 0;
431 sum = calculate_checksum_update(sum, (uint16_t*)&pkt6->ip6_hdr.sadr, 16);
432 sum = calculate_checksum_update(sum, (uint16_t*)&pkt6->ip6_hdr.dadr, 16);
433 uint32_t tmp = (pkt6->udp_hdr.len & 0xffff);
434 sum = calculate_checksum_update(sum, (uint16_t*)&tmp, 4);
435 tmp = htons(((pkt6->ip6_hdr.nxthdr & 0x00ff)));
436 sum = calculate_checksum_update(sum, (uint16_t*)&tmp, 4);
438 sum = calculate_checksum_update(sum, (uint16_t*)&pkt6->udp_hdr, ntohs(pkt->len));
439 pkt6->udp_hdr.crc = calculate_checksum_end(sum);
441 write_to_helper(pkt6, size);
446 void init_mesh (void* cls, struct GNUNET_MESH_Handle* server, const struct GNUNET_PeerIdentity* my_identity, const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *pubkey) {
447 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Connected to MESH, I am %x\n", *((unsigned long*)my_identity));
450 void connect_mesh (void* cls, const struct GNUNET_PeerIdentity* peer, const struct GNUNET_TRANSPORT_ATS_Information *atsi) {
451 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Connected to peer %x\n", *((unsigned long*)peer));
455 * Main function that will be run by the scheduler.
458 * @param args remaining command-line arguments
459 * @param cfgfile name of the configuration file used (for saving, can be NULL!)
460 * @param cfg_ configuration
466 const struct GNUNET_CONFIGURATION_Handle *cfg_)
468 const static struct GNUNET_MESH_MessageHandler handlers[] = {
469 {receive_udp_back, GNUNET_MESSAGE_TYPE_SERVICE_UDP_BACK, 0},
472 mesh_handle = GNUNET_MESH_connect(cfg_,
478 hashmap = GNUNET_CONTAINER_multihashmap_create(65536);
479 udp_connections = GNUNET_CONTAINER_multihashmap_create(65536);
480 GNUNET_SCHEDULER_add_now (connect_to_service_dns, NULL);
481 GNUNET_SCHEDULER_add_now (start_helper_and_schedule, NULL);
482 GNUNET_SCHEDULER_add_delayed(GNUNET_TIME_UNIT_FOREVER_REL, &cleanup, cls);
486 * The main function to obtain template from gnunetd.
488 * @param argc number of arguments from the command line
489 * @param argv command line arguments
490 * @return 0 ok, 1 on error
493 main (int argc, char *const *argv) {
494 static const struct GNUNET_GETOPT_CommandLineOption options[] = {
495 GNUNET_GETOPT_OPTION_END
499 GNUNET_PROGRAM_run (argc,
502 gettext_noop ("help text"),
503 options, &run, NULL)) ? ret : 1;
506 /* end of gnunet-daemon-vpn.c */