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 scheduler to use throughout the service
  44  */
  45 static struct GNUNET_SCHEDULER_Handle *sched;
  46
  47 /**
  48  * The UDP-Socket through which DNS-Resolves will be sent if they are not to be
  49  * sent through gnunet. The port of this socket will not be hijacked.
  50  */
  51 static struct GNUNET_NETWORK_Handle *dnsout;
  52
  53 /**
  54  * The port bound to the socket dnsout
  55  */
  56 static unsigned short dnsoutport;
  57
  58 /**
  59  * A handle to the DHT-Service
  60  */
  61 static struct GNUNET_DHT_Handle *dht;
  62
  63 /**
  64  * The configuration to use
  65  */
  66 static const struct GNUNET_CONFIGURATION_Handle *cfg;
  67
  68 /**
  69  * A list of DNS-Responses that have to be sent to the requesting client
  70  */
  71 static struct answer_packet_list *head;
  72
  73 /**
  74  * The tail of the list of DNS-responses
  75  */
  76 static struct answer_packet_list *tail;
  77
  78 /**
  79  * A structure containing a mapping from network-byte-ordered DNS-id to
  80  * some information needed to handle this query
  81  *
  82  * It currently allocates at least
  83  * (1 + machine-width + 32 + 32 + 16 + machine-width + 8) * 65536 bit
  84  * = 1.7 MiB on 64 bit.
  85  * = 1.2 MiB on 32 bit.
  86  */
  87 static struct {
  88     unsigned valid:1;
  89     struct GNUNET_SERVER_Client* client;
  90     unsigned local_ip:32;
  91     unsigned remote_ip:32;
  92     unsigned local_port:16;
  93     char* name;
  94     unsigned namelen:8;
  95 } query_states[65536];
  96
  97 /**
  98  * A struct used to give more than one value as
  99  * closure to receive_dht
 100  */
 101 struct receive_dht_cls {
 102     unsigned short id;
 103     struct GNUNET_DHT_GetHandle* handle;
 104 };
 105
 106 /**
 107  * Hijack all outgoing DNS-Traffic but for traffic leaving "our" port.
 108  */
 109 static void
 110 hijack(void* cls, const struct GNUNET_SCHEDULER_TaskContext* tc) {
 111     char port_s[6];
 112
 113     GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Hijacking, port is %d\n", dnsoutport);
 114     snprintf(port_s, 6, "%d", dnsoutport);
 115     GNUNET_OS_process_close (GNUNET_OS_start_process(NULL,
 116                                                      NULL,
 117                                                      "gnunet-helper-hijack-dns",
 118                                                      "gnunet-hijack-dns",
 119                                                      port_s,
 120                                                      NULL));
 121 }
 122
 123 /**
 124  * Delete the hijacking-routes
 125  */
 126 static void
 127 unhijack(unsigned short port) {
 128     char port_s[6];
 129
 130     GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "unHijacking, port is %d\n", port);
 131     snprintf(port_s, 6, "%d", port);
 132     GNUNET_OS_start_process(NULL,
 133                             NULL,
 134                             "gnunet-helper-hijack-dns",
 135                             "gnunet-hijack-dns",
 136                             "-d",
 137                             port_s,
 138                             NULL);
 139 }
 140
 141 /**
 142  * Send the DNS-Response to the client. Gets called via the notify_transmit_ready-
 143  * system.
 144  */
 145 static size_t
 146 send_answer(void* cls, size_t size, void* buf) {
 147     struct answer_packet_list* query = head;
 148     size_t len = ntohs(query->pkt.hdr.size);
 149
 150     GNUNET_assert(len <= size);
 151
 152     memcpy(buf, &query->pkt.hdr, len);
 153
 154     GNUNET_CONTAINER_DLL_remove (head, tail, query);
 155
 156     GNUNET_free(query);
 157
 158     /* When more data is to be sent, reschedule */
 159     if (head != NULL)
 160       GNUNET_SERVER_notify_transmit_ready(cls,
 161                                           ntohs(head->pkt.hdr.size),
 162                                           GNUNET_TIME_UNIT_FOREVER_REL,
 163                                           &send_answer,
 164                                           cls);
 165
 166     return len;
 167 }
 168
 169 static void
 170 send_rev_query(void * cls, const struct GNUNET_SCHEDULER_TaskContext *tc) {
 171     struct dns_pkt_parsed* pdns = (struct dns_pkt_parsed*) cls;
 172
 173     unsigned short id = pdns->s.id;
 174
 175     if (query_states[id].valid != GNUNET_YES) return;
 176     query_states[id].valid = GNUNET_NO;
 177
 178     GNUNET_assert(query_states[id].namelen == 74);
 179
 180     size_t len = sizeof(struct answer_packet) - 1 \
 181                  + sizeof(struct dns_static) \
 182                  + 74 /* this is the length of a reverse ipv6-lookup */ \
 183                  + sizeof(struct dns_query_line) \
 184                  + 2 /* To hold the pointer (as defined in RFC1035) to the name */ \
 185                  + sizeof(struct dns_record_line) - 1 \
 186                  - 2 /* We do not know the lenght of the answer yet*/ \
 187                  - 2 /* No idea why... */ ;
 188
 189     struct answer_packet_list* answer = GNUNET_malloc(len + 2*sizeof(struct answer_packet_list*));
 190     memset(answer, 0, len + 2*sizeof(struct answer_packet_list*));
 191
 192     answer->pkt.hdr.type = htons(GNUNET_MESSAGE_TYPE_LOCAL_RESPONSE_DNS);
 193     answer->pkt.hdr.size = htons(len);
 194     answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_REV;
 195
 196     answer->pkt.from = query_states[id].remote_ip;
 197
 198     answer->pkt.to = query_states[id].local_ip;
 199     answer->pkt.dst_port = query_states[id].local_port;
 200
 201     struct dns_pkt *dpkt = (struct dns_pkt*)answer->pkt.data;
 202
 203     dpkt->s.id = id;
 204     dpkt->s.aa = 1;
 205     dpkt->s.qr = 1;
 206     dpkt->s.ra = 1;
 207     dpkt->s.qdcount = htons(1);
 208     dpkt->s.ancount = htons(1);
 209
 210     memcpy(dpkt->data, query_states[id].name, query_states[id].namelen);
 211     GNUNET_free(query_states[id].name);
 212
 213     struct dns_query_line* dque = (struct dns_query_line*)(dpkt->data+(query_states[id].namelen));
 214     dque->type = htons(12); /* PTR */
 215     dque->class = htons(1); /* IN */
 216
 217     char* anname = (char*)(dpkt->data+(query_states[id].namelen)+sizeof(struct dns_query_line));
 218     memcpy(anname, (char[]){0xc0, 0x0c}, 2);
 219
 220     struct dns_record_line *drec_data = (struct dns_record_line*)(dpkt->data+(query_states[id].namelen)+sizeof(struct dns_query_line)+2);
 221     drec_data->type = htons(12); /* AAAA */
 222     drec_data->class = htons(1); /* IN */
 223     drec_data->ttl = htonl(3600); /* FIXME: read from block */
 224
 225     /* Calculate at which offset in the packet the length of the name and the
 226      * name, it is filled in by the daemon-vpn */
 227     answer->pkt.addroffset = htons((unsigned short)((unsigned long)(&drec_data->data_len)-(unsigned long)(&answer->pkt)));
 228
 229     GNUNET_CONTAINER_DLL_insert_after(head, tail, tail, answer);
 230
 231     GNUNET_SERVER_notify_transmit_ready(query_states[id].client,
 232                                         len,
 233                                         GNUNET_TIME_UNIT_FOREVER_REL,
 234                                         &send_answer,
 235                                         query_states[id].client);
 236
 237     /*
 238      * build
 239      * complete dns-packet with empty name in the answer
 240      * provide offsett of the name
 241      */
 242 }
 243
 244 /**
 245  * Receive a block from the dht.
 246  */
 247 static void
 248 receive_dht(void *cls,
 249             struct GNUNET_TIME_Absolute exp,
 250             const GNUNET_HashCode *key,
 251             const struct GNUNET_PeerIdentity *const *get_path,
 252             const struct GNUNET_PeerIdentity *const *put_path,
 253             enum GNUNET_BLOCK_Type type,
 254             size_t size,
 255             const void *data) {
 256
 257     unsigned short id = ((struct receive_dht_cls*)cls)->id;
 258     struct GNUNET_DHT_GetHandle* handle = ((struct receive_dht_cls*)cls)->handle;
 259     GNUNET_free(cls);
 260
 261     GNUNET_assert(type == GNUNET_BLOCK_TYPE_DNS);
 262
 263     /* If no query with this id is pending, ignore the block */
 264     if (query_states[id].valid != GNUNET_YES) return;
 265     query_states[id].valid = GNUNET_NO;
 266
 267     const struct GNUNET_DNS_Record* rec = data;
 268     GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
 269                "Got block of size %d, peer: %08x, desc: %08x\n",
 270                size,
 271                *((unsigned int*)&rec->peer),
 272                *((unsigned int*)&rec->service_descriptor));
 273
 274     size_t len = sizeof(struct answer_packet) - 1 \
 275                  + sizeof(struct dns_static) \
 276                  + query_states[id].namelen \
 277                  + sizeof(struct dns_query_line) \
 278                  + 2 /* To hold the pointer (as defined in RFC1035) to the name */ \
 279                  + sizeof(struct dns_record_line) - 1 \
 280                  + 16; /* To hold the IPv6-Address */
 281
 282     struct answer_packet_list* answer = GNUNET_malloc(len + 2*sizeof(struct answer_packet_list*));
 283     memset(answer, 0, len + 2*sizeof(struct answer_packet_list*));
 284
 285     answer->pkt.hdr.type = htons(GNUNET_MESSAGE_TYPE_LOCAL_RESPONSE_DNS);
 286     answer->pkt.hdr.size = htons(len);
 287     answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_SERVICE;
 288
 289     GNUNET_CRYPTO_hash(&rec->peer,
 290                        sizeof(struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
 291                        &answer->pkt.peer);
 292
 293     memcpy(&answer->pkt.service_descriptor,
 294            &rec->service_descriptor,
 295            sizeof(GNUNET_HashCode));
 296     memcpy(&answer->pkt.service_type,
 297            &rec->service_type,
 298            sizeof(answer->pkt.service_type));
 299     memcpy(&answer->pkt.ports, &rec->ports, sizeof(answer->pkt.ports));
 300
 301     answer->pkt.from = query_states[id].remote_ip;
 302
 303     answer->pkt.to = query_states[id].local_ip;
 304     answer->pkt.dst_port = query_states[id].local_port;
 305
 306     struct dns_pkt *dpkt = (struct dns_pkt*)answer->pkt.data;
 307
 308     dpkt->s.id = id;
 309     dpkt->s.aa = 1;
 310     dpkt->s.qr = 1;
 311     dpkt->s.ra = 1;
 312     dpkt->s.qdcount = htons(1);
 313     dpkt->s.ancount = htons(1);
 314
 315     memcpy(dpkt->data, query_states[id].name, query_states[id].namelen);
 316     GNUNET_free(query_states[id].name);
 317
 318     struct dns_query_line* dque = (struct dns_query_line*)(dpkt->data+(query_states[id].namelen));
 319     dque->type = htons(28); /* AAAA */
 320     dque->class = htons(1); /* IN */
 321
 322     char* anname = (char*)(dpkt->data+(query_states[id].namelen)+sizeof(struct dns_query_line));
 323     memcpy(anname, (char[]){0xc0, 0x0c}, 2);
 324
 325     struct dns_record_line *drec_data = (struct dns_record_line*)(dpkt->data+(query_states[id].namelen)+sizeof(struct dns_query_line)+2);
 326     drec_data->type = htons(28); /* AAAA */
 327     drec_data->class = htons(1); /* IN */
 328     drec_data->ttl = htonl(3600); /* FIXME: read from block */
 329     drec_data->data_len = htons(16);
 330
 331     /* Calculate at which offset in the packet the IPv6-Address belongs, it is
 332      * filled in by the daemon-vpn */
 333     answer->pkt.addroffset = htons((unsigned short)((unsigned long)(&drec_data->data)-(unsigned long)(&answer->pkt)));
 334
 335     GNUNET_CONTAINER_DLL_insert_after(head, tail, tail, answer);
 336
 337     GNUNET_SERVER_notify_transmit_ready(query_states[id].client,
 338                                         len,
 339                                         GNUNET_TIME_UNIT_FOREVER_REL,
 340                                         &send_answer,
 341                                         query_states[id].client);
 342
 343     GNUNET_DHT_get_stop(handle);
 344 }
 345
 346 /**
 347  * This receives a GNUNET_MESSAGE_TYPE_REHIJACK and rehijacks the DNS
 348  */
 349 static void
 350 rehijack(void *cls,
 351          struct GNUNET_SERVER_Client *client,
 352          const struct GNUNET_MessageHeader *message) {
 353     unhijack(dnsoutport);
 354     GNUNET_SCHEDULER_add_delayed(sched, GNUNET_TIME_UNIT_SECONDS, hijack, NULL);
 355
 356     GNUNET_SERVER_receive_done(client, GNUNET_OK);
 357 }
 358
 359 /**
 360  * This receives the dns-payload from the daemon-vpn and sends it on over the udp-socket
 361  */
 362 static void
 363 receive_query(void *cls,
 364               struct GNUNET_SERVER_Client *client,
 365               const struct GNUNET_MessageHeader *message) {
 366     struct query_packet* pkt = (struct query_packet*)message;
 367     struct dns_pkt* dns = (struct dns_pkt*)pkt->data;
 368     struct dns_pkt_parsed* pdns = parse_dns_packet(dns);
 369
 370     query_states[dns->s.id].valid = GNUNET_YES;
 371     query_states[dns->s.id].client = client;
 372     query_states[dns->s.id].local_ip = pkt->orig_from;
 373     query_states[dns->s.id].local_port = pkt->src_port;
 374     query_states[dns->s.id].remote_ip = pkt->orig_to;
 375     query_states[dns->s.id].namelen = strlen((char*)dns->data) + 1;
 376     query_states[dns->s.id].name = GNUNET_malloc(query_states[dns->s.id].namelen);
 377     memcpy(query_states[dns->s.id].name, dns->data, query_states[dns->s.id].namelen);
 378
 379     /* The query is for a .gnunet-address */
 380     if (pdns->queries[0]->namelen > 9 &&
 381         0 == strncmp(pdns->queries[0]->name+(pdns->queries[0]->namelen - 9), ".gnunet.", 9))
 382       {
 383         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Query for .gnunet!\n");
 384         GNUNET_HashCode key;
 385         GNUNET_CRYPTO_hash(pdns->queries[0]->name, pdns->queries[0]->namelen, &key);
 386
 387         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
 388                    "Getting with key %08x, len is %d\n",
 389                    *((unsigned int*)&key),
 390                    pdns->queries[0]->namelen);
 391
 392         struct receive_dht_cls* cls = GNUNET_malloc(sizeof(struct receive_dht_cls));
 393         cls->id = dns->s.id;
 394
 395         cls->handle = GNUNET_DHT_get_start(dht,
 396                                            GNUNET_TIME_UNIT_MINUTES,
 397                                            GNUNET_BLOCK_TYPE_DNS,
 398                                            &key,
 399                                            GNUNET_DHT_RO_NONE,
 400                                            NULL,
 401                                            0,
 402                                            NULL,
 403                                            0,
 404                                            receive_dht,
 405                                            cls);
 406
 407         goto outfree;
 408       }
 409
 410     /* The query is for a PTR of a previosly resolved virtual IP */
 411     if (htons(pdns->queries[0]->qtype) == 12 &&
 412         pdns->queries[0]->namelen > 19 &&
 413         0 == strncmp(pdns->queries[0]->name+(pdns->queries[0]->namelen - 19), ".4.3.2.1.ip6.arpa.", 19))
 414       {
 415         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Reverse-Query for .gnunet!\n");
 416
 417         GNUNET_SCHEDULER_add_now(sched, send_rev_query, pdns);
 418
 419         goto out;
 420       }
 421
 422     /* The query should be sent to the network */
 423
 424     struct sockaddr_in dest;
 425     memset(&dest, 0, sizeof dest);
 426     dest.sin_port = htons(53);
 427     dest.sin_addr.s_addr = pkt->orig_to;
 428
 429     GNUNET_NETWORK_socket_sendto(dnsout,
 430                                  dns,
 431                                  ntohs(pkt->hdr.size) - sizeof(struct query_packet) + 1,
 432                                  (struct sockaddr*) &dest,
 433                                  sizeof dest);
 434
 435 outfree:
 436     free_parsed_dns_packet(pdns);
 437     pdns = NULL;
 438 out:
 439     GNUNET_SERVER_receive_done(client, GNUNET_OK);
 440 }
 441
 442 /**
 443  * Read a response-packet of the UDP-Socket
 444  */
 445 static void
 446 read_response (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) {
 447     unsigned char buf[65536];
 448     struct dns_pkt* dns = (struct dns_pkt*)buf;
 449
 450     if (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)
 451       return;
 452
 453     struct sockaddr_in addr;
 454     memset(&addr, 0, sizeof addr);
 455     unsigned int addrlen = sizeof addr;
 456
 457     int r;
 458     r = GNUNET_NETWORK_socket_recvfrom(dnsout,
 459                                        buf,
 460                                        65536,
 461                                        (struct sockaddr*)&addr,
 462                                        &addrlen);
 463
 464     /* if (r < 0) FIXME */
 465
 466     if (query_states[dns->s.id].valid == GNUNET_YES) {
 467         query_states[dns->s.id].valid = GNUNET_NO;
 468
 469         size_t len = sizeof(struct answer_packet) + r - 1; /* 1 for the unsigned char data[1]; */
 470         struct answer_packet_list* answer = GNUNET_malloc(len + 2*sizeof(struct answer_packet_list*));
 471         answer->pkt.hdr.type = htons(GNUNET_MESSAGE_TYPE_LOCAL_RESPONSE_DNS);
 472         answer->pkt.hdr.size = htons(len);
 473         answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_IP;
 474         answer->pkt.from = addr.sin_addr.s_addr;
 475         answer->pkt.to = query_states[dns->s.id].local_ip;
 476         answer->pkt.dst_port = query_states[dns->s.id].local_port;
 477         memcpy(answer->pkt.data, buf, r);
 478
 479         GNUNET_CONTAINER_DLL_insert_after(head, tail, tail, answer);
 480
 481         GNUNET_SERVER_notify_transmit_ready(query_states[dns->s.id].client,
 482                                             len,
 483                                             GNUNET_TIME_UNIT_FOREVER_REL,
 484                                             &send_answer,
 485                                             query_states[dns->s.id].client);
 486     }
 487
 488     GNUNET_SCHEDULER_add_read_net(sched,
 489                                   GNUNET_TIME_UNIT_FOREVER_REL,
 490                                   dnsout,
 491                                   &read_response,
 492                                   NULL);
 493 }
 494
 495
 496 /**
 497  * Task run during shutdown.
 498  *
 499  * @param cls unused
 500  * @param tc unused
 501  */
 502 static void
 503 cleanup_task (void *cls,
 504               const struct GNUNET_SCHEDULER_TaskContext *tc)
 505 {
 506   unhijack(dnsoutport);
 507   GNUNET_DHT_disconnect(dht);
 508 }
 509
 510 /**
 511  * Publish a DNS-record in the DHT. This is up to now just for testing.
 512  */
 513 static void
 514 publish_name (void *cls,
 515               const struct GNUNET_SCHEDULER_TaskContext *tc) {
 516     if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
 517       return;
 518
 519     char* name = "philipptoelke.gnunet.";
 520     size_t size = sizeof(struct GNUNET_DNS_Record);
 521     struct GNUNET_DNS_Record data;
 522     memset(&data, 0, size);
 523
 524     data.purpose.size = htonl(size - sizeof(struct GNUNET_CRYPTO_RsaSignature));
 525     data.purpose.purpose = GNUNET_SIGNATURE_PURPOSE_DNS_RECORD;
 526
 527     GNUNET_CRYPTO_hash(name, strlen(name)+1, &data.service_descriptor);
 528
 529     char* keyfile;
 530     if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_filename(cfg, "GNUNETD",
 531                                                              "HOSTKEY", &keyfile))
 532       {
 533         GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "could not read keyfile-value\n");
 534         if (keyfile != NULL) GNUNET_free(keyfile);
 535         return;
 536       }
 537
 538     struct GNUNET_CRYPTO_RsaPrivateKey *my_private_key = GNUNET_CRYPTO_rsa_key_create_from_file(keyfile);
 539     GNUNET_free(keyfile);
 540
 541     GNUNET_CRYPTO_rsa_key_get_public(my_private_key, &data.peer);
 542
 543     data.expiration_time = GNUNET_TIME_relative_to_absolute(GNUNET_TIME_UNIT_HOURS);
 544
 545   /* Sign the block */
 546     if (GNUNET_OK != GNUNET_CRYPTO_rsa_sign(my_private_key,
 547                                             &data.purpose,
 548                                             &data.signature))
 549       {
 550         GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "could not sign DNS_Record\n");
 551         return;
 552       }
 553     GNUNET_CRYPTO_rsa_key_free(my_private_key);
 554
 555     GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
 556                "Putting with key %08x\n",
 557                *((unsigned int*)&data.service_descriptor));
 558
 559     GNUNET_DHT_put(dht,
 560                    &data.service_descriptor,
 561                    GNUNET_DHT_RO_NONE,
 562                    GNUNET_BLOCK_TYPE_DNS,
 563                    size,
 564                    (char*)&data,
 565                    GNUNET_TIME_relative_to_absolute(GNUNET_TIME_UNIT_HOURS),
 566                    GNUNET_TIME_UNIT_MINUTES,
 567                    NULL,
 568                    NULL);
 569
 570     GNUNET_SCHEDULER_add_delayed (sched,
 571                                   GNUNET_TIME_UNIT_HOURS,
 572                                   publish_name,
 573                                   NULL);
 574 }
 575
 576 /**
 577  * @param cls closure
 578  * @param sched scheduler to use
 579  * @param server the initialized server
 580  * @param cfg configuration to use
 581  */
 582 static void
 583 run (void *cls,
 584      struct GNUNET_SCHEDULER_Handle *sched_,
 585      struct GNUNET_SERVER_Handle *server,
 586      const struct GNUNET_CONFIGURATION_Handle *cfg_)
 587 {
 588   static const struct GNUNET_SERVER_MessageHandler handlers[] = {
 589       /* callback, cls, type, size */
 590         {&receive_query, NULL, GNUNET_MESSAGE_TYPE_LOCAL_QUERY_DNS, 0},
 591         {&rehijack, NULL, GNUNET_MESSAGE_TYPE_REHIJACK, sizeof(struct GNUNET_MessageHeader)},
 592         {NULL, NULL, 0, 0}
 593   };
 594
 595   cfg = cfg_;
 596   sched = sched_;
 597
 598   unsigned int i;
 599   for (i = 0; i < 65536; i++) {
 600       query_states[i].valid = GNUNET_NO;
 601   }
 602
 603   dht = GNUNET_DHT_connect(sched, cfg, 1024);
 604
 605   struct sockaddr_in addr;
 606
 607   dnsout = GNUNET_NETWORK_socket_create (AF_INET, SOCK_DGRAM, 0);
 608   if (dnsout == NULL)
 609     return;
 610   memset(&addr, 0, sizeof(struct sockaddr_in));
 611
 612   int err = GNUNET_NETWORK_socket_bind (dnsout,
 613                                         (struct sockaddr*)&addr,
 614                                         sizeof(struct sockaddr_in));
 615
 616   if (err != GNUNET_YES) {
 617       GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "Could not bind a port, exiting\n");
 618       return;
 619   }
 620
 621   /* Read the port we bound to */
 622   socklen_t addrlen = sizeof(struct sockaddr_in);
 623   err = getsockname(GNUNET_NETWORK_get_fd(dnsout),
 624                     (struct sockaddr*) &addr,
 625                     &addrlen);
 626
 627   dnsoutport = htons(addr.sin_port);
 628
 629   GNUNET_SCHEDULER_add_now (sched, publish_name, NULL);
 630
 631   GNUNET_SCHEDULER_add_read_net(sched, GNUNET_TIME_UNIT_FOREVER_REL, dnsout, &read_response, NULL);
 632
 633   GNUNET_SERVER_add_handlers (server, handlers);
 634   GNUNET_SCHEDULER_add_delayed (sched,
 635                                 GNUNET_TIME_UNIT_FOREVER_REL,
 636                                 &cleanup_task,
 637                                 cls);
 638 }
 639
 640 /**
 641  * The main function for the dns service.
 642  *
 643  * @param argc number of arguments from the command line
 644  * @param argv command line arguments
 645  * @return 0 ok, 1 on error
 646  */
 647 int
 648 main (int argc, char *const *argv)
 649 {
 650   return (GNUNET_OK ==
 651           GNUNET_SERVICE_run (argc,
 652                               argv,
 653                               "dns",
 654                               GNUNET_SERVICE_OPTION_NONE,
 655                               &run, NULL)) ? 0 : 1;
 656 }