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) {
64 shs_task = GNUNET_SCHEDULER_NO_TASK;
65 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
78 if (GNUNET_SYSERR == GNUNET_CONFIGURATION_get_value_string(cfg, "vpn", "IFNAME", &ifname))
80 GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "No entry 'IFNAME' in configuration!\n");
84 if (GNUNET_SYSERR == GNUNET_CONFIGURATION_get_value_string(cfg, "vpn", "IPV6ADDR", &ipv6addr))
86 GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "No entry 'IPV6ADDR' in configuration!\n");
90 if (GNUNET_SYSERR == GNUNET_CONFIGURATION_get_value_string(cfg, "vpn", "IPV6PREFIX", &ipv6prefix))
92 GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "No entry 'IPV6PREFIX' in configuration!\n");
96 if (GNUNET_SYSERR == GNUNET_CONFIGURATION_get_value_string(cfg, "vpn", "IPV4ADDR", &ipv4addr))
98 GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "No entry 'IPV4ADDR' in configuration!\n");
102 if (GNUNET_SYSERR == GNUNET_CONFIGURATION_get_value_string(cfg, "vpn", "IPV4MASK", &ipv4mask))
104 GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "No entry 'IPV4MASK' in configuration!\n");
109 * Messages get passed to the function message_token
110 * When the helper dies, this function will be called again with the
111 * helper_handle as cls.
113 helper_handle = start_helper(ifname,
119 start_helper_and_schedule,
123 GNUNET_free(ipv6addr);
124 GNUNET_free(ipv6prefix);
125 GNUNET_free(ipv4addr);
126 GNUNET_free(ipv4mask);
129 /* Tell the dns-service to rehijack the dns-port
130 * The routing-table gets flushed if an interface disappears.
133 if (NULL != dns_connection)
134 GNUNET_CLIENT_notify_transmit_ready(dns_connection, sizeof(struct GNUNET_MessageHeader), GNUNET_TIME_UNIT_FOREVER_REL, GNUNET_YES, &send_query, NULL);
136 GNUNET_SCHEDULER_add_write_file (GNUNET_TIME_UNIT_FOREVER_REL, helper_handle->fh_to_helper, &helper_write, NULL);
141 * Send an dns-answer-packet to the helper
144 helper_write(void* cls __attribute__((unused)), const struct GNUNET_SCHEDULER_TaskContext* tsdkctx) {
145 if (tsdkctx->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)
148 struct answer_packet_list* ans = answer_proc_head;
150 if (NULL == ans) return;
152 size_t len = ntohs(ans->pkt.hdr.size);
154 GNUNET_assert(ans->pkt.subtype == GNUNET_DNS_ANSWER_TYPE_IP);
156 GNUNET_assert (20 == sizeof (struct ip_hdr));
157 GNUNET_assert (8 == sizeof (struct udp_pkt));
158 size_t data_len = len - sizeof(struct answer_packet) + 1;
159 size_t net_len = sizeof(struct ip_hdr) + sizeof(struct udp_dns) + data_len;
160 size_t pkt_len = sizeof(struct GNUNET_MessageHeader) + sizeof(struct pkt_tun) + net_len;
162 struct ip_udp_dns* pkt = alloca(pkt_len);
163 GNUNET_assert(pkt != NULL);
164 memset(pkt, 0, pkt_len);
166 /* set the gnunet-header */
167 pkt->shdr.size = htons(pkt_len);
168 pkt->shdr.type = htons(GNUNET_MESSAGE_TYPE_VPN_HELPER);
170 /* set the tun-header (no flags and ethertype of IPv4) */
172 pkt->tun.type = htons(0x0800);
174 /* set the ip-header */
175 pkt->ip_hdr.version = 4;
176 pkt->ip_hdr.hdr_lngth = 5;
177 pkt->ip_hdr.diff_serv = 0;
178 pkt->ip_hdr.tot_lngth = htons(net_len);
179 pkt->ip_hdr.ident = 0;
180 pkt->ip_hdr.flags = 0;
181 pkt->ip_hdr.frag_off = 0;
182 pkt->ip_hdr.ttl = 255;
183 pkt->ip_hdr.proto = 0x11; /* UDP */
184 pkt->ip_hdr.chks = 0; /* Will be calculated later*/
185 pkt->ip_hdr.sadr = ans->pkt.from;
186 pkt->ip_hdr.dadr = ans->pkt.to;
188 pkt->ip_hdr.chks = calculate_ip_checksum((uint16_t*)&pkt->ip_hdr, 5*4);
190 /* set the udp-header */
191 pkt->udp_dns.udp_hdr.spt = htons(53);
192 pkt->udp_dns.udp_hdr.dpt = ans->pkt.dst_port;
193 pkt->udp_dns.udp_hdr.len = htons(net_len - sizeof(struct ip_hdr));
194 pkt->udp_dns.udp_hdr.crc = 0; /* Optional for IPv4 */
196 memcpy(&pkt->udp_dns.data, ans->pkt.data, data_len);
198 GNUNET_CONTAINER_DLL_remove (answer_proc_head, answer_proc_tail, ans);
201 if (GNUNET_DISK_file_write(helper_handle->fh_to_helper, pkt, pkt_len) < 0)
203 cleanup_helper(helper_handle);
204 GNUNET_SCHEDULER_add_now(start_helper_and_schedule, NULL);
208 /* if more packets are available, reschedule */
209 if (answer_proc_head != NULL)
210 GNUNET_SCHEDULER_add_write_file (GNUNET_TIME_UNIT_FOREVER_REL,
211 helper_handle->fh_to_helper,
217 * Receive packets from the helper-process
220 message_token (void *cls __attribute__((unused)),
221 void *client __attribute__((unused)), const struct GNUNET_MessageHeader *message)
223 GNUNET_assert (ntohs (message->type) == GNUNET_MESSAGE_TYPE_VPN_HELPER);
225 struct tun_pkt *pkt_tun = (struct tun_pkt *) message;
227 /* ethertype is ipv6 */
228 if (ntohs (pkt_tun->tun.type) == 0x86dd)
230 struct ip6_pkt *pkt6 = (struct ip6_pkt *) message;
231 GNUNET_assert (pkt6->ip6_hdr.version == 6);
232 struct ip6_tcp *pkt6_tcp;
233 struct ip6_udp *pkt6_udp;
234 struct ip6_icmp *pkt6_icmp;
235 GNUNET_HashCode *key;
237 switch (pkt6->ip6_hdr.nxthdr)
241 pkt6_tcp = (struct ip6_tcp *) pkt6;
242 pkt6_udp = (struct ip6_udp *) pkt6;
244 if ((key = address_mapping_exists (pkt6->ip6_hdr.dadr)) != NULL)
246 struct map_entry *me =
247 GNUNET_CONTAINER_multihashmap_get (hashmap, key);
248 GNUNET_assert (me != NULL);
252 sizeof (struct GNUNET_MESH_Tunnel *) +
253 sizeof (struct GNUNET_MessageHeader) +
254 sizeof (GNUNET_HashCode) + ntohs (pkt6->ip6_hdr.paylgth);
256 struct GNUNET_MESH_Tunnel **cls = GNUNET_malloc (size);
257 struct GNUNET_MessageHeader *hdr =
258 (struct GNUNET_MessageHeader *) (cls + 1);
259 GNUNET_HashCode *hc = (GNUNET_HashCode *) (hdr + 1);
261 hdr->size = htons (sizeof (struct GNUNET_MessageHeader) +
262 sizeof (GNUNET_HashCode) +
263 ntohs (pkt6->ip6_hdr.paylgth));
265 GNUNET_MESH_ApplicationType app_type;
266 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "me->addrlen is %d\n", me->addrlen);
267 if (me->addrlen == 0)
269 /* This is a mapping to a gnunet-service */
270 memcpy (hc, &me->desc.service_descriptor,
271 sizeof (GNUNET_HashCode));
273 if (0x11 == pkt6->ip6_hdr.nxthdr
275 service_type & htonl (GNUNET_DNS_SERVICE_TYPE_UDP))
276 && (port_in_ports (me->desc.ports, pkt6_udp->udp_hdr.dpt)
277 || testBit (me->additional_ports,
278 ntohs (pkt6_udp->udp_hdr.dpt))))
280 hdr->type = ntohs (GNUNET_MESSAGE_TYPE_SERVICE_UDP);
282 memcpy (hc + 1, &pkt6_udp->udp_hdr,
283 ntohs (pkt6_udp->udp_hdr.len));
286 else if (0x06 == pkt6->ip6_hdr.nxthdr
288 service_type & htonl (GNUNET_DNS_SERVICE_TYPE_TCP))
290 (port_in_ports (me->desc.ports, pkt6_tcp->tcp_hdr.dpt)))
292 hdr->type = ntohs (GNUNET_MESSAGE_TYPE_SERVICE_TCP);
294 memcpy (hc + 1, &pkt6_tcp->tcp_hdr,
295 ntohs (pkt6->ip6_hdr.paylgth));
298 if (me->tunnel == NULL && NULL != cls)
301 GNUNET_MESH_peer_request_connect_all (mesh_handle,
302 GNUNET_TIME_UNIT_FOREVER_REL,
311 else if (NULL != cls)
314 send_pkt_to_peer (cls, (struct GNUNET_PeerIdentity *) 1,
316 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
317 "Queued to send to peer %x, type %d\n",
318 *((unsigned int *) &me->desc.peer), ntohs(hdr->type));
323 /* This is a mapping to a "real" address */
324 struct remote_addr *s = (struct remote_addr*) hc;
325 s->addrlen = me->addrlen;
326 memcpy(s->addr, me->addr, me->addrlen);
327 s->proto= pkt6->ip6_hdr.nxthdr;
328 if (s->proto == 0x11)
330 hdr->type = GNUNET_MESSAGE_TYPE_REMOTE_UDP;
331 memcpy (hc + 1, &pkt6_udp->udp_hdr,
332 ntohs (pkt6_udp->udp_hdr.len));
333 app_type = GNUNET_APPLICATION_TYPE_INTERNET_UDP_GATEWAY;
334 if (NULL != udp_tunnel)
335 me->tunnel = udp_tunnel;
337 else if (s->proto == 0x06)
339 hdr->type = GNUNET_MESSAGE_TYPE_REMOTE_TCP;
340 memcpy (hc + 1, &pkt6_tcp->tcp_hdr,
341 ntohs (pkt6->ip6_hdr.paylgth));
342 app_type = GNUNET_APPLICATION_TYPE_INTERNET_TCP_GATEWAY;
343 if (NULL != tcp_tunnel)
344 me->tunnel = tcp_tunnel;
346 if (me->tunnel == NULL && NULL != cls)
348 *cls = GNUNET_MESH_peer_request_connect_by_type(mesh_handle,
349 GNUNET_TIME_UNIT_FOREVER_REL,
355 if (GNUNET_APPLICATION_TYPE_INTERNET_UDP_GATEWAY == app_type)
357 else if (GNUNET_APPLICATION_TYPE_INTERNET_TCP_GATEWAY == app_type)
360 else if (NULL != cls)
363 send_pkt_to_peer(cls, (struct GNUNET_PeerIdentity*) 1, NULL);
369 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Packet to %02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x, which has no mapping\n", pkt6->ip6_hdr.dadr[0],
370 pkt6->ip6_hdr.dadr[1],
371 pkt6->ip6_hdr.dadr[2],
372 pkt6->ip6_hdr.dadr[3],
373 pkt6->ip6_hdr.dadr[4],
374 pkt6->ip6_hdr.dadr[5],
375 pkt6->ip6_hdr.dadr[6],
376 pkt6->ip6_hdr.dadr[7],
377 pkt6->ip6_hdr.dadr[8],
378 pkt6->ip6_hdr.dadr[9],
379 pkt6->ip6_hdr.dadr[10],
380 pkt6->ip6_hdr.dadr[11],
381 pkt6->ip6_hdr.dadr[12],
382 pkt6->ip6_hdr.dadr[13],
383 pkt6->ip6_hdr.dadr[14],
384 pkt6->ip6_hdr.dadr[15]);
389 pkt6_icmp = (struct ip6_icmp *) pkt6;
390 /* If this packet is an icmp-echo-request and a mapping exists, answer */
391 if (pkt6_icmp->icmp_hdr.type == 0x80
392 && (key = address_mapping_exists (pkt6->ip6_hdr.dadr)) != NULL)
395 pkt6_icmp = GNUNET_malloc (ntohs (pkt6->shdr.size));
396 memcpy (pkt6_icmp, pkt6, ntohs (pkt6->shdr.size));
397 GNUNET_SCHEDULER_add_now (&send_icmp_response, pkt6_icmp);
402 /* ethertype is ipv4 */
403 else if (ntohs (pkt_tun->tun.type) == 0x0800)
405 struct ip_pkt *pkt = (struct ip_pkt *) message;
406 struct ip_udp *udp = (struct ip_udp *) message;
407 GNUNET_assert (pkt->ip_hdr.version == 4);
409 /* Send dns-packets to the service-dns */
410 if (pkt->ip_hdr.proto == 0x11 && ntohs (udp->udp_hdr.dpt) == 53)
412 /* 9 = 8 for the udp-header + 1 for the unsigned char data[1]; */
414 sizeof (struct query_packet) + ntohs (udp->udp_hdr.len) - 9;
416 struct query_packet_list *query =
417 GNUNET_malloc (len + 2 * sizeof (struct query_packet_list *));
418 query->pkt.hdr.type = htons (GNUNET_MESSAGE_TYPE_LOCAL_QUERY_DNS);
419 query->pkt.hdr.size = htons (len);
420 query->pkt.orig_to = pkt->ip_hdr.dadr;
421 query->pkt.orig_from = pkt->ip_hdr.sadr;
422 query->pkt.src_port = udp->udp_hdr.spt;
423 memcpy (query->pkt.data, udp->data, ntohs (udp->udp_hdr.len) - 8);
425 GNUNET_CONTAINER_DLL_insert_after (head, tail, tail, query);
427 GNUNET_assert (head != NULL);
429 if (dns_connection != NULL)
430 GNUNET_CLIENT_notify_transmit_ready (dns_connection,
432 GNUNET_TIME_UNIT_FOREVER_REL,
439 void write_to_helper(void* buf, size_t len)
441 (void)GNUNET_DISK_file_write(helper_handle->fh_to_helper, buf, len);
444 void schedule_helper_write(struct GNUNET_TIME_Relative time, void* cls)
446 if (GNUNET_SCHEDULER_NO_TASK == shs_task) return;
447 GNUNET_SCHEDULER_add_write_file (time, helper_handle->fh_to_helper, &helper_write, cls);