src/vpn/gnunet-service-dns.c

   1 /*
   2      This file is part of GNUnet.
   3      (C) 2009 Christian Grothoff (and other contributing authors)
   4
   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.
   9
  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.
  14
  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.
  19 */
  20
  21 /**
  22  * @file vpn/gnunet-service-dns.c
  23  * @author Philipp Toelke
  24  */
  25 #include "platform.h"
  26 #include "gnunet_getopt_lib.h"
  27 #include "gnunet_service_lib.h"
  28 #include "gnunet_network_lib.h"
  29 #include "gnunet_os_lib.h"
  30 #include "gnunet-service-dns-p.h"
  31 #include "gnunet_protocols.h"
  32 #include "gnunet-vpn-packet.h"
  33 #include "gnunet-vpn-pretty-print.h"
  34 #include "gnunet_container_lib.h"
  35 #include "gnunet-dns-parser.h"
  36 #include "gnunet_dht_service.h"
  37 #include "gnunet_block_lib.h"
  38 #include "block_dns.h"
  39 #include "gnunet_crypto_lib.h"
  40 #include "gnunet_signatures.h"
  41
  42 /**
  43  * The UDP-Socket through which DNS-Resolves will be sent if they are not to be
  44  * sent through gnunet. The port of this socket will not be hijacked.
  45  */
  46 static struct GNUNET_NETWORK_Handle *dnsout;
  47
  48 /**
  49  * The port bound to the socket dnsout
  50  */
  51 static unsigned short dnsoutport;
  52
  53 /**
  54  * A handle to the DHT-Service
  55  */
  56 static struct GNUNET_DHT_Handle *dht;
  57
  58 /**
  59  * The configuration to use
  60  */
  61 static const struct GNUNET_CONFIGURATION_Handle *cfg;
  62
  63 /**
  64  * A list of DNS-Responses that have to be sent to the requesting client
  65  */
  66 static struct answer_packet_list *head;
  67
  68 /**
  69  * The tail of the list of DNS-responses
  70  */
  71 static struct answer_packet_list *tail;
  72
  73 /**
  74  * A structure containing a mapping from network-byte-ordered DNS-id to
  75  * some information needed to handle this query
  76  *
  77  * It currently allocates at least
  78  * (1 + machine-width + 32 + 32 + 16 + machine-width + 8) * 65536 bit
  79  * = 1.7 MiB on 64 bit.
  80  * = 1.2 MiB on 32 bit.
  81  */
  82 static struct {
  83     unsigned valid:1;
  84     struct GNUNET_SERVER_Client* client;
  85     unsigned local_ip:32;
  86     unsigned remote_ip:32;
  87     unsigned local_port:16;
  88     char* name;
  89     unsigned namelen:8;
  90 } query_states[65536];
  91
  92 /**
  93  * A struct used to give more than one value as
  94  * closure to receive_dht
  95  */
  96 struct receive_dht_cls {
  97     unsigned short id;
  98     struct GNUNET_DHT_GetHandle* handle;
  99 };
 100
 101 /**
 102  * Hijack all outgoing DNS-Traffic but for traffic leaving "our" port.
 103  */
 104 static void
 105 hijack(void* cls, const struct GNUNET_SCHEDULER_TaskContext* tc) {
 106     char port_s[6];
 107
 108     GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Hijacking, port is %d\n", dnsoutport);
 109     snprintf(port_s, 6, "%d", dnsoutport);
 110     GNUNET_OS_process_close (GNUNET_OS_start_process(NULL,
 111                                                      NULL,
 112                                                      "gnunet-helper-hijack-dns",
 113                                                      "gnunet-hijack-dns",
 114                                                      port_s,
 115                                                      NULL));
 116 }
 117
 118 /**
 119  * Delete the hijacking-routes
 120  */
 121 static void
 122 unhijack(unsigned short port) {
 123     char port_s[6];
 124
 125     GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "unHijacking, port is %d\n", port);
 126     snprintf(port_s, 6, "%d", port);
 127     GNUNET_OS_start_process(NULL,
 128                             NULL,
 129                             "gnunet-helper-hijack-dns",
 130                             "gnunet-hijack-dns",
 131                             "-d",
 132                             port_s,
 133                             NULL);
 134 }
 135
 136 /**
 137  * Send the DNS-Response to the client. Gets called via the notify_transmit_ready-
 138  * system.
 139  */
 140 static size_t
 141 send_answer(void* cls, size_t size, void* buf) {
 142     struct answer_packet_list* query = head;
 143     size_t len = ntohs(query->pkt.hdr.size);
 144
 145     GNUNET_assert(len <= size);
 146
 147     memcpy(buf, &query->pkt.hdr, len);
 148
 149     GNUNET_CONTAINER_DLL_remove (head, tail, query);
 150
 151     GNUNET_free(query);
 152
 153     /* When more data is to be sent, reschedule */
 154     if (head != NULL)
 155       GNUNET_SERVER_notify_transmit_ready(cls,
 156                                           ntohs(head->pkt.hdr.size),
 157                                           GNUNET_TIME_UNIT_FOREVER_REL,
 158                                           &send_answer,
 159                                           cls);
 160
 161     return len;
 162 }
 163
 164 static void
 165 send_rev_query(void * cls, const struct GNUNET_SCHEDULER_TaskContext *tc) {
 166     struct dns_pkt_parsed* pdns = (struct dns_pkt_parsed*) cls;
 167
 168     unsigned short id = pdns->s.id;
 169
 170     if (query_states[id].valid != GNUNET_YES) return;
 171     query_states[id].valid = GNUNET_NO;
 172
 173     GNUNET_assert(query_states[id].namelen == 74);
 174
 175     size_t len = sizeof(struct answer_packet) - 1 \
 176                  + sizeof(struct dns_static) \
 177                  + 74 /* this is the length of a reverse ipv6-lookup */ \
 178                  + sizeof(struct dns_query_line) \
 179                  + 2 /* To hold the pointer (as defined in RFC1035) to the name */ \
 180                  + sizeof(struct dns_record_line) - 1 \
 181                  - 2 /* We do not know the lenght of the answer yet*/ \
 182                  - 2 /* No idea why... */ ;
 183
 184     struct answer_packet_list* answer = GNUNET_malloc(len + 2*sizeof(struct answer_packet_list*));
 185     memset(answer, 0, len + 2*sizeof(struct answer_packet_list*));
 186
 187     answer->pkt.hdr.type = htons(GNUNET_MESSAGE_TYPE_LOCAL_RESPONSE_DNS);
 188     answer->pkt.hdr.size = htons(len);
 189     answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_REV;
 190
 191     answer->pkt.from = query_states[id].remote_ip;
 192
 193     answer->pkt.to = query_states[id].local_ip;
 194     answer->pkt.dst_port = query_states[id].local_port;
 195
 196     struct dns_pkt *dpkt = (struct dns_pkt*)answer->pkt.data;
 197
 198     dpkt->s.id = id;
 199     dpkt->s.aa = 1;
 200     dpkt->s.qr = 1;
 201     dpkt->s.ra = 1;
 202     dpkt->s.qdcount = htons(1);
 203     dpkt->s.ancount = htons(1);
 204
 205     memcpy(dpkt->data, query_states[id].name, query_states[id].namelen);
 206     GNUNET_free(query_states[id].name);
 207
 208     struct dns_query_line* dque = (struct dns_query_line*)(dpkt->data+(query_states[id].namelen));
 209     dque->type = htons(12); /* PTR */
 210     dque->class = htons(1); /* IN */
 211
 212     char* anname = (char*)(dpkt->data+(query_states[id].namelen)+sizeof(struct dns_query_line));
 213     memcpy(anname, (char[]){0xc0, 0x0c}, 2);
 214
 215     struct dns_record_line *drec_data = (struct dns_record_line*)(dpkt->data+(query_states[id].namelen)+sizeof(struct dns_query_line)+2);
 216     drec_data->type = htons(12); /* AAAA */
 217     drec_data->class = htons(1); /* IN */
 218     drec_data->ttl = htonl(3600); /* FIXME: read from block */
 219
 220     /* Calculate at which offset in the packet the length of the name and the
 221      * name, it is filled in by the daemon-vpn */
 222     answer->pkt.addroffset = htons((unsigned short)((unsigned long)(&drec_data->data_len)-(unsigned long)(&answer->pkt)));
 223
 224     GNUNET_CONTAINER_DLL_insert_after(head, tail, tail, answer);
 225
 226     GNUNET_SERVER_notify_transmit_ready(query_states[id].client,
 227                                         len,
 228                                         GNUNET_TIME_UNIT_FOREVER_REL,
 229                                         &send_answer,
 230                                         query_states[id].client);
 231
 232     /*
 233      * build
 234      * complete dns-packet with empty name in the answer
 235      * provide offsett of the name
 236      */
 237 }
 238
 239 /**
 240  * Receive a block from the dht.
 241  */
 242 static void
 243 receive_dht(void *cls,
 244             struct GNUNET_TIME_Absolute exp,
 245             const GNUNET_HashCode *key,
 246             const struct GNUNET_PeerIdentity *const *get_path,
 247             const struct GNUNET_PeerIdentity *const *put_path,
 248             enum GNUNET_BLOCK_Type type,
 249             size_t size,
 250             const void *data) {
 251
 252     unsigned short id = ((struct receive_dht_cls*)cls)->id;
 253     struct GNUNET_DHT_GetHandle* handle = ((struct receive_dht_cls*)cls)->handle;
 254     GNUNET_free(cls);
 255
 256     GNUNET_assert(type == GNUNET_BLOCK_TYPE_DNS);
 257
 258     /* If no query with this id is pending, ignore the block */
 259     if (query_states[id].valid != GNUNET_YES) return;
 260     query_states[id].valid = GNUNET_NO;
 261
 262     const struct GNUNET_DNS_Record* rec = data;
 263     GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
 264                "Got block of size %d, peer: %08x, desc: %08x\n",
 265                size,
 266                *((unsigned int*)&rec->peer),
 267                *((unsigned int*)&rec->service_descriptor));
 268
 269     size_t len = sizeof(struct answer_packet) - 1 \
 270                  + sizeof(struct dns_static) \
 271                  + query_states[id].namelen \
 272                  + sizeof(struct dns_query_line) \
 273                  + 2 /* To hold the pointer (as defined in RFC1035) to the name */ \
 274                  + sizeof(struct dns_record_line) - 1 \
 275                  + 16; /* To hold the IPv6-Address */
 276
 277     struct answer_packet_list* answer = GNUNET_malloc(len + 2*sizeof(struct answer_packet_list*));
 278     memset(answer, 0, len + 2*sizeof(struct answer_packet_list*));
 279
 280     answer->pkt.hdr.type = htons(GNUNET_MESSAGE_TYPE_LOCAL_RESPONSE_DNS);
 281     answer->pkt.hdr.size = htons(len);
 282     answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_SERVICE;
 283
 284     GNUNET_CRYPTO_hash(&rec->peer,
 285                        sizeof(struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
 286                        &answer->pkt.service_descr.peer);
 287
 288     memcpy(&answer->pkt.service_descr.service_descriptor,
 289            &rec->service_descriptor,
 290            sizeof(GNUNET_HashCode));
 291     memcpy(&answer->pkt.service_descr.service_type,
 292            &rec->service_type,
 293            sizeof(answer->pkt.service_descr.service_type));
 294     memcpy(&answer->pkt.service_descr.ports, &rec->ports, sizeof(answer->pkt.service_descr.ports));
 295
 296     answer->pkt.from = query_states[id].remote_ip;
 297
 298     answer->pkt.to = query_states[id].local_ip;
 299     answer->pkt.dst_port = query_states[id].local_port;
 300
 301     struct dns_pkt *dpkt = (struct dns_pkt*)answer->pkt.data;
 302
 303     dpkt->s.id = id;
 304     dpkt->s.aa = 1;
 305     dpkt->s.qr = 1;
 306     dpkt->s.ra = 1;
 307     dpkt->s.qdcount = htons(1);
 308     dpkt->s.ancount = htons(1);
 309
 310     memcpy(dpkt->data, query_states[id].name, query_states[id].namelen);
 311     GNUNET_free(query_states[id].name);
 312
 313     struct dns_query_line* dque = (struct dns_query_line*)(dpkt->data+(query_states[id].namelen));
 314     dque->type = htons(28); /* AAAA */
 315     dque->class = htons(1); /* IN */
 316
 317     char* anname = (char*)(dpkt->data+(query_states[id].namelen)+sizeof(struct dns_query_line));
 318     memcpy(anname, (char[]){0xc0, 0x0c}, 2);
 319
 320     struct dns_record_line *drec_data = (struct dns_record_line*)(dpkt->data+(query_states[id].namelen)+sizeof(struct dns_query_line)+2);
 321     drec_data->type = htons(28); /* AAAA */
 322     drec_data->class = htons(1); /* IN */
 323     drec_data->ttl = htonl(3600); /* FIXME: read from block */
 324     drec_data->data_len = htons(16);
 325
 326     /* Calculate at which offset in the packet the IPv6-Address belongs, it is
 327      * filled in by the daemon-vpn */
 328     answer->pkt.addroffset = htons((unsigned short)((unsigned long)(&drec_data->data)-(unsigned long)(&answer->pkt)));
 329
 330     GNUNET_CONTAINER_DLL_insert_after(head, tail, tail, answer);
 331
 332     GNUNET_SERVER_notify_transmit_ready(query_states[id].client,
 333                                         len,
 334                                         GNUNET_TIME_UNIT_FOREVER_REL,
 335                                         &send_answer,
 336                                         query_states[id].client);
 337
 338     GNUNET_DHT_get_stop(handle);
 339 }
 340
 341 /**
 342  * This receives a GNUNET_MESSAGE_TYPE_REHIJACK and rehijacks the DNS
 343  */
 344 static void
 345 rehijack(void *cls,
 346          struct GNUNET_SERVER_Client *client,
 347          const struct GNUNET_MessageHeader *message) {
 348     unhijack(dnsoutport);
 349     GNUNET_SCHEDULER_add_delayed(GNUNET_TIME_UNIT_SECONDS, hijack, NULL);
 350
 351     GNUNET_SERVER_receive_done(client, GNUNET_OK);
 352 }
 353
 354 /**
 355  * This receives the dns-payload from the daemon-vpn and sends it on over the udp-socket
 356  */
 357 static void
 358 receive_query(void *cls,
 359               struct GNUNET_SERVER_Client *client,
 360               const struct GNUNET_MessageHeader *message) {
 361     struct query_packet* pkt = (struct query_packet*)message;
 362     struct dns_pkt* dns = (struct dns_pkt*)pkt->data;
 363     struct dns_pkt_parsed* pdns = parse_dns_packet(dns);
 364
 365     query_states[dns->s.id].valid = GNUNET_YES;
 366     query_states[dns->s.id].client = client;
 367     query_states[dns->s.id].local_ip = pkt->orig_from;
 368     query_states[dns->s.id].local_port = pkt->src_port;
 369     query_states[dns->s.id].remote_ip = pkt->orig_to;
 370     query_states[dns->s.id].namelen = strlen((char*)dns->data) + 1;
 371     query_states[dns->s.id].name = GNUNET_malloc(query_states[dns->s.id].namelen);
 372     memcpy(query_states[dns->s.id].name, dns->data, query_states[dns->s.id].namelen);
 373
 374     /* The query is for a .gnunet-address */
 375     if (pdns->queries[0]->namelen > 9 &&
 376         0 == strncmp(pdns->queries[0]->name+(pdns->queries[0]->namelen - 9), ".gnunet.", 9))
 377       {
 378         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Query for .gnunet!\n");
 379         GNUNET_HashCode key;
 380         GNUNET_CRYPTO_hash(pdns->queries[0]->name, pdns->queries[0]->namelen, &key);
 381
 382         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
 383                    "Getting with key %08x, len is %d\n",
 384                    *((unsigned int*)&key),
 385                    pdns->queries[0]->namelen);
 386
 387         struct receive_dht_cls* cls = GNUNET_malloc(sizeof(struct receive_dht_cls));
 388         cls->id = dns->s.id;
 389
 390         cls->handle = GNUNET_DHT_get_start(dht,
 391                                            GNUNET_TIME_UNIT_MINUTES,
 392                                            GNUNET_BLOCK_TYPE_DNS,
 393                                            &key,
 394                                            DEFAULT_GET_REPLICATION,
 395                                            GNUNET_DHT_RO_NONE,
 396                                            NULL,
 397                                            0,
 398                                            NULL,
 399                                            0,
 400                                            receive_dht,
 401                                            cls);
 402
 403         goto outfree;
 404       }
 405
 406     /* The query is for a PTR of a previosly resolved virtual IP */
 407     if (htons(pdns->queries[0]->qtype) == 12 &&
 408         pdns->queries[0]->namelen > 19 &&
 409         0 == strncmp(pdns->queries[0]->name+(pdns->queries[0]->namelen - 19), ".4.3.2.1.ip6.arpa.", 19))
 410       {
 411         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Reverse-Query for .gnunet!\n");
 412
 413         GNUNET_SCHEDULER_add_now(send_rev_query, pdns);
 414
 415         goto out;
 416       }
 417
 418     /* The query should be sent to the network */
 419
 420     struct sockaddr_in dest;
 421     memset(&dest, 0, sizeof dest);
 422     dest.sin_port = htons(53);
 423     dest.sin_addr.s_addr = pkt->orig_to;
 424
 425     GNUNET_NETWORK_socket_sendto(dnsout,
 426                                  dns,
 427                                  ntohs(pkt->hdr.size) - sizeof(struct query_packet) + 1,
 428                                  (struct sockaddr*) &dest,
 429                                  sizeof dest);
 430
 431 outfree:
 432     free_parsed_dns_packet(pdns);
 433     pdns = NULL;
 434 out:
 435     GNUNET_SERVER_receive_done(client, GNUNET_OK);
 436 }
 437
 438 /**
 439  * Read a response-packet of the UDP-Socket
 440  */
 441 static void
 442 read_response (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) {
 443     unsigned char buf[65536];
 444     struct dns_pkt* dns = (struct dns_pkt*)buf;
 445
 446     if (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)
 447       return;
 448
 449     struct sockaddr_in addr;
 450     memset(&addr, 0, sizeof addr);
 451     socklen_t addrlen = sizeof addr;
 452
 453     int r;
 454     r = GNUNET_NETWORK_socket_recvfrom(dnsout,
 455                                        buf,
 456                                        65536,
 457                                        (struct sockaddr*)&addr,
 458                                        &addrlen);
 459
 460     /* if (r < 0) FIXME */
 461
 462     if (query_states[dns->s.id].valid == GNUNET_YES) {
 463         query_states[dns->s.id].valid = GNUNET_NO;
 464
 465         size_t len = sizeof(struct answer_packet) + r - 1; /* 1 for the unsigned char data[1]; */
 466         struct answer_packet_list* answer = GNUNET_malloc(len + 2*sizeof(struct answer_packet_list*));
 467         answer->pkt.hdr.type = htons(GNUNET_MESSAGE_TYPE_LOCAL_RESPONSE_DNS);
 468         answer->pkt.hdr.size = htons(len);
 469         answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_IP;
 470         answer->pkt.from = addr.sin_addr.s_addr;
 471         answer->pkt.to = query_states[dns->s.id].local_ip;
 472         answer->pkt.dst_port = query_states[dns->s.id].local_port;
 473         memcpy(answer->pkt.data, buf, r);
 474
 475         GNUNET_CONTAINER_DLL_insert_after(head, tail, tail, answer);
 476
 477         GNUNET_SERVER_notify_transmit_ready(query_states[dns->s.id].client,
 478                                             len,
 479                                             GNUNET_TIME_UNIT_FOREVER_REL,
 480                                             &send_answer,
 481                                             query_states[dns->s.id].client);
 482     }
 483
 484     GNUNET_SCHEDULER_add_read_net(GNUNET_TIME_UNIT_FOREVER_REL,
 485                                   dnsout,
 486                                   &read_response,
 487                                   NULL);
 488 }
 489
 490
 491 /**
 492  * Task run during shutdown.
 493  *
 494  * @param cls unused
 495  * @param tc unused
 496  */
 497 static void
 498 cleanup_task (void *cls,
 499               const struct GNUNET_SCHEDULER_TaskContext *tc)
 500 {
 501   unhijack(dnsoutport);
 502   GNUNET_DHT_disconnect(dht);
 503 }
 504
 505 /**
 506  * Publish a DNS-record in the DHT. This is up to now just for testing.
 507  */
 508 static void
 509 publish_name (void *cls,
 510               const struct GNUNET_SCHEDULER_TaskContext *tc) {
 511     if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
 512       return;
 513
 514     char* name = "philipptoelke.gnunet.";
 515     size_t size = sizeof(struct GNUNET_DNS_Record);
 516     struct GNUNET_DNS_Record data;
 517     memset(&data, 0, size);
 518
 519     data.purpose.size = htonl(size - sizeof(struct GNUNET_CRYPTO_RsaSignature));
 520     data.purpose.purpose = GNUNET_SIGNATURE_PURPOSE_DNS_RECORD;
 521
 522     GNUNET_CRYPTO_hash(name, strlen(name)+1, &data.service_descriptor);
 523
 524     data.service_type = htonl(GNUNET_DNS_SERVICE_TYPE_UDP);
 525     data.ports = htons(69);
 526
 527     char* keyfile;
 528     if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_filename(cfg, "GNUNETD",
 529                                                              "HOSTKEY", &keyfile))
 530       {
 531         GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "could not read keyfile-value\n");
 532         if (keyfile != NULL) GNUNET_free(keyfile);
 533         return;
 534       }
 535
 536     struct GNUNET_CRYPTO_RsaPrivateKey *my_private_key = GNUNET_CRYPTO_rsa_key_create_from_file(keyfile);
 537     GNUNET_free(keyfile);
 538
 539     GNUNET_CRYPTO_rsa_key_get_public(my_private_key, &data.peer);
 540
 541     data.expiration_time = GNUNET_TIME_relative_to_absolute(GNUNET_TIME_UNIT_HOURS);
 542
 543   /* Sign the block */
 544     if (GNUNET_OK != GNUNET_CRYPTO_rsa_sign(my_private_key,
 545                                             &data.purpose,
 546                                             &data.signature))
 547       {
 548         GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "could not sign DNS_Record\n");
 549         return;
 550       }
 551     GNUNET_CRYPTO_rsa_key_free(my_private_key);
 552
 553     GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
 554                "Putting with key %08x\n",
 555                *((unsigned int*)&data.service_descriptor));
 556
 557     GNUNET_DHT_put(dht,
 558                    &data.service_descriptor,
 559                    DEFAULT_PUT_REPLICATION,
 560                    GNUNET_DHT_RO_NONE,
 561                    GNUNET_BLOCK_TYPE_DNS,
 562                    size,
 563                    (char*)&data,
 564                    GNUNET_TIME_relative_to_absolute(GNUNET_TIME_UNIT_HOURS),
 565                    GNUNET_TIME_UNIT_MINUTES,
 566                    NULL,
 567                    NULL);
 568
 569     GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_HOURS,
 570                                   publish_name,
 571                                   NULL);
 572 }
 573
 574 /**
 575  * @param cls closure
 576  * @param sched scheduler to use
 577  * @param server the initialized server
 578  * @param cfg configuration to use
 579  */
 580 static void
 581 run (void *cls,
 582      struct GNUNET_SERVER_Handle *server,
 583      const struct GNUNET_CONFIGURATION_Handle *cfg_)
 584 {
 585   static const struct GNUNET_SERVER_MessageHandler handlers[] = {
 586       /* callback, cls, type, size */
 587         {&receive_query, NULL, GNUNET_MESSAGE_TYPE_LOCAL_QUERY_DNS, 0},
 588         {&rehijack, NULL, GNUNET_MESSAGE_TYPE_REHIJACK, sizeof(struct GNUNET_MessageHeader)},
 589         {NULL, NULL, 0, 0}
 590   };
 591
 592   cfg = cfg_;
 593
 594   unsigned int i;
 595   for (i = 0; i < 65536; i++) {
 596       query_states[i].valid = GNUNET_NO;
 597   }
 598
 599   dht = GNUNET_DHT_connect(cfg, 1024);
 600
 601   struct sockaddr_in addr;
 602
 603   dnsout = GNUNET_NETWORK_socket_create (AF_INET, SOCK_DGRAM, 0);
 604   if (dnsout == NULL)
 605     return;
 606   memset(&addr, 0, sizeof(struct sockaddr_in));
 607
 608   int err = GNUNET_NETWORK_socket_bind (dnsout,
 609                                         (struct sockaddr*)&addr,
 610                                         sizeof(struct sockaddr_in));
 611
 612   if (err != GNUNET_YES) {
 613       GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "Could not bind a port, exiting\n");
 614       return;
 615   }
 616
 617   /* Read the port we bound to */
 618   socklen_t addrlen = sizeof(struct sockaddr_in);
 619   err = getsockname(GNUNET_NETWORK_get_fd(dnsout),
 620                     (struct sockaddr*) &addr,
 621                     &addrlen);
 622
 623   dnsoutport = htons(addr.sin_port);
 624
 625   GNUNET_SCHEDULER_add_now (publish_name, NULL);
 626
 627   GNUNET_SCHEDULER_add_read_net(GNUNET_TIME_UNIT_FOREVER_REL, dnsout, &read_response, NULL);
 628
 629   GNUNET_SERVER_add_handlers (server, handlers);
 630   GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
 631                                 &cleanup_task,
 632                                 cls);
 633 }
 634
 635 /**
 636  * The main function for the dns service.
 637  *
 638  * @param argc number of arguments from the command line
 639  * @param argv command line arguments
 640  * @return 0 ok, 1 on error
 641  */
 642 int
 643 main (int argc, char *const *argv)
 644 {
 645   return (GNUNET_OK ==
 646           GNUNET_SERVICE_run (argc,
 647                               argv,
 648                               "dns",
 649                               GNUNET_SERVICE_OPTION_NONE,
 650                               &run, NULL)) ? 0 : 1;
 651 }