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 {
 107   char port_s[6];
 108   char *virt_dns;
 109   struct GNUNET_OS_Process *proc;
 110
 111   if (GNUNET_SYSERR ==
 112       GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "VIRTDNS",
 113                                              &virt_dns))
 114     {
 115       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 116                   "No entry 'VIRTDNS' in configuration!\n");
 117       exit (1);
 118     }
 119
 120   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Hijacking, port is %d\n", dnsoutport);
 121   snprintf (port_s, 6, "%d", dnsoutport);
 122   if (NULL != (proc = GNUNET_OS_start_process (NULL,
 123                                                NULL,
 124                                                "gnunet-helper-hijack-dns",
 125                                                "gnunet-hijack-dns",
 126                                                port_s, virt_dns, NULL)))
 127     GNUNET_OS_process_close (proc);
 128   GNUNET_free (virt_dns);
 129 }
 130
 131 /**
 132  * Delete the hijacking-routes
 133  */
 134 static void
 135 unhijack (unsigned short port)
 136 {
 137   char port_s[6];
 138   char *virt_dns;
 139   struct GNUNET_OS_Process *proc;
 140
 141   if (GNUNET_SYSERR ==
 142       GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "VIRTDNS",
 143                                              &virt_dns))
 144     {
 145       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 146                   "No entry 'VIRTDNS' in configuration!\n");
 147       exit (1);
 148     }
 149
 150   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "unHijacking, port is %d\n", port);
 151   snprintf (port_s, 6, "%d", port);
 152   if (NULL != (proc = GNUNET_OS_start_process (NULL,
 153                                                NULL,
 154                                                "gnunet-helper-hijack-dns",
 155                                                "gnunet-hijack-dns",
 156                                                "-d", port_s, virt_dns, NULL)))
 157     GNUNET_OS_process_close (proc);
 158   GNUNET_free (virt_dns);
 159 }
 160
 161 /**
 162  * Send the DNS-Response to the client. Gets called via the notify_transmit_ready-
 163  * system.
 164  */
 165 static size_t
 166 send_answer(void* cls, size_t size, void* buf) {
 167     struct answer_packet_list* query = head;
 168     size_t len = ntohs(query->pkt.hdr.size);
 169
 170     GNUNET_assert(len <= size);
 171
 172     memcpy(buf, &query->pkt.hdr, len);
 173
 174     GNUNET_CONTAINER_DLL_remove (head, tail, query);
 175
 176     GNUNET_free(query);
 177
 178     /* When more data is to be sent, reschedule */
 179     if (head != NULL)
 180       GNUNET_SERVER_notify_transmit_ready(cls,
 181                                           ntohs(head->pkt.hdr.size),
 182                                           GNUNET_TIME_UNIT_FOREVER_REL,
 183                                           &send_answer,
 184                                           cls);
 185
 186     return len;
 187 }
 188
 189 static void
 190 send_rev_query(void * cls, const struct GNUNET_SCHEDULER_TaskContext *tc) {
 191     struct dns_pkt_parsed* pdns = (struct dns_pkt_parsed*) cls;
 192
 193     unsigned short id = pdns->s.id;
 194
 195     if (query_states[id].valid != GNUNET_YES) return;
 196     query_states[id].valid = GNUNET_NO;
 197
 198     GNUNET_assert(query_states[id].namelen == 74);
 199
 200     size_t len = sizeof(struct answer_packet) - 1 \
 201                  + sizeof(struct dns_static) \
 202                  + 74 /* this is the length of a reverse ipv6-lookup */ \
 203                  + sizeof(struct dns_query_line) \
 204                  + 2 /* To hold the pointer (as defined in RFC1035) to the name */ \
 205                  + sizeof(struct dns_record_line) - 1 \
 206                  - 2 /* We do not know the lenght of the answer yet*/ \
 207                  - 2 /* No idea why... */ ;
 208
 209     struct answer_packet_list* answer = GNUNET_malloc(len + 2*sizeof(struct answer_packet_list*));
 210     memset(answer, 0, len + 2*sizeof(struct answer_packet_list*));
 211
 212     answer->pkt.hdr.type = htons(GNUNET_MESSAGE_TYPE_LOCAL_RESPONSE_DNS);
 213     answer->pkt.hdr.size = htons(len);
 214     answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_REV;
 215
 216     answer->pkt.from = query_states[id].remote_ip;
 217
 218     answer->pkt.to = query_states[id].local_ip;
 219     answer->pkt.dst_port = query_states[id].local_port;
 220
 221     struct dns_pkt *dpkt = (struct dns_pkt*)answer->pkt.data;
 222
 223     dpkt->s.id = id;
 224     dpkt->s.aa = 1;
 225     dpkt->s.qr = 1;
 226     dpkt->s.ra = 1;
 227     dpkt->s.qdcount = htons(1);
 228     dpkt->s.ancount = htons(1);
 229
 230     memcpy(dpkt->data, query_states[id].name, query_states[id].namelen);
 231     GNUNET_free(query_states[id].name);
 232
 233     struct dns_query_line* dque = (struct dns_query_line*)(dpkt->data+(query_states[id].namelen));
 234     dque->type = htons(12); /* PTR */
 235     dque->class = htons(1); /* IN */
 236
 237     char* anname = (char*)(dpkt->data+(query_states[id].namelen)+sizeof(struct dns_query_line));
 238     memcpy(anname, (char[]){0xc0, 0x0c}, 2);
 239
 240     struct dns_record_line *drec_data = (struct dns_record_line*)(dpkt->data+(query_states[id].namelen)+sizeof(struct dns_query_line)+2);
 241     drec_data->type = htons(12); /* AAAA */
 242     drec_data->class = htons(1); /* IN */
 243     drec_data->ttl = htonl(3600); /* FIXME: read from block */
 244
 245     /* Calculate at which offset in the packet the length of the name and the
 246      * name, it is filled in by the daemon-vpn */
 247     answer->pkt.addroffset = htons((unsigned short)((unsigned long)(&drec_data->data_len)-(unsigned long)(&answer->pkt)));
 248
 249     GNUNET_CONTAINER_DLL_insert_after(head, tail, tail, answer);
 250
 251     GNUNET_SERVER_notify_transmit_ready(query_states[id].client,
 252                                         len,
 253                                         GNUNET_TIME_UNIT_FOREVER_REL,
 254                                         &send_answer,
 255                                         query_states[id].client);
 256
 257     /*
 258      * build
 259      * complete dns-packet with empty name in the answer
 260      * provide offsett of the name
 261      */
 262 }
 263
 264 /**
 265  * Receive a block from the dht.
 266  */
 267 static void
 268 receive_dht(void *cls,
 269             struct GNUNET_TIME_Absolute exp,
 270             const GNUNET_HashCode *key,
 271             const struct GNUNET_PeerIdentity *const *get_path,
 272             const struct GNUNET_PeerIdentity *const *put_path,
 273             enum GNUNET_BLOCK_Type type,
 274             size_t size,
 275             const void *data) {
 276
 277     unsigned short id = ((struct receive_dht_cls*)cls)->id;
 278     struct GNUNET_DHT_GetHandle* handle = ((struct receive_dht_cls*)cls)->handle;
 279     GNUNET_free(cls);
 280
 281     GNUNET_assert(type == GNUNET_BLOCK_TYPE_DNS);
 282
 283     /* If no query with this id is pending, ignore the block */
 284     if (query_states[id].valid != GNUNET_YES) return;
 285     query_states[id].valid = GNUNET_NO;
 286
 287     const struct GNUNET_DNS_Record* rec = data;
 288     GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
 289                "Got block of size %d, peer: %08x, desc: %08x\n",
 290                size,
 291                *((unsigned int*)&rec->peer),
 292                *((unsigned int*)&rec->service_descriptor));
 293
 294     size_t len = sizeof(struct answer_packet) - 1 \
 295                  + sizeof(struct dns_static) \
 296                  + query_states[id].namelen \
 297                  + sizeof(struct dns_query_line) \
 298                  + 2 /* To hold the pointer (as defined in RFC1035) to the name */ \
 299                  + sizeof(struct dns_record_line) - 1 \
 300                  + 16; /* To hold the IPv6-Address */
 301
 302     struct answer_packet_list* answer = GNUNET_malloc(len + 2*sizeof(struct answer_packet_list*));
 303     memset(answer, 0, len + 2*sizeof(struct answer_packet_list*));
 304
 305     answer->pkt.hdr.type = htons(GNUNET_MESSAGE_TYPE_LOCAL_RESPONSE_DNS);
 306     answer->pkt.hdr.size = htons(len);
 307     answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_SERVICE;
 308
 309     GNUNET_CRYPTO_hash(&rec->peer,
 310                        sizeof(struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
 311                        &answer->pkt.service_descr.peer);
 312
 313     memcpy(&answer->pkt.service_descr.service_descriptor,
 314            &rec->service_descriptor,
 315            sizeof(GNUNET_HashCode));
 316     memcpy(&answer->pkt.service_descr.service_type,
 317            &rec->service_type,
 318            sizeof(answer->pkt.service_descr.service_type));
 319     memcpy(&answer->pkt.service_descr.ports, &rec->ports, sizeof(answer->pkt.service_descr.ports));
 320
 321     answer->pkt.from = query_states[id].remote_ip;
 322
 323     answer->pkt.to = query_states[id].local_ip;
 324     answer->pkt.dst_port = query_states[id].local_port;
 325
 326     struct dns_pkt *dpkt = (struct dns_pkt*)answer->pkt.data;
 327
 328     dpkt->s.id = id;
 329     dpkt->s.aa = 1;
 330     dpkt->s.qr = 1;
 331     dpkt->s.ra = 1;
 332     dpkt->s.qdcount = htons(1);
 333     dpkt->s.ancount = htons(1);
 334
 335     memcpy(dpkt->data, query_states[id].name, query_states[id].namelen);
 336     GNUNET_free(query_states[id].name);
 337
 338     struct dns_query_line* dque = (struct dns_query_line*)(dpkt->data+(query_states[id].namelen));
 339     dque->type = htons(28); /* AAAA */
 340     dque->class = htons(1); /* IN */
 341
 342     char* anname = (char*)(dpkt->data+(query_states[id].namelen)+sizeof(struct dns_query_line));
 343     memcpy(anname, (char[]){0xc0, 0x0c}, 2);
 344
 345     struct dns_record_line *drec_data = (struct dns_record_line*)(dpkt->data+(query_states[id].namelen)+sizeof(struct dns_query_line)+2);
 346     drec_data->type = htons(28); /* AAAA */
 347     drec_data->class = htons(1); /* IN */
 348     drec_data->ttl = htonl(3600); /* FIXME: read from block */
 349     drec_data->data_len = htons(16);
 350
 351     /* Calculate at which offset in the packet the IPv6-Address belongs, it is
 352      * filled in by the daemon-vpn */
 353     answer->pkt.addroffset = htons((unsigned short)((unsigned long)(&drec_data->data)-(unsigned long)(&answer->pkt)));
 354
 355     GNUNET_CONTAINER_DLL_insert_after(head, tail, tail, answer);
 356
 357     GNUNET_SERVER_notify_transmit_ready(query_states[id].client,
 358                                         len,
 359                                         GNUNET_TIME_UNIT_FOREVER_REL,
 360                                         &send_answer,
 361                                         query_states[id].client);
 362
 363     GNUNET_DHT_get_stop(handle);
 364 }
 365
 366 /**
 367  * This receives a GNUNET_MESSAGE_TYPE_REHIJACK and rehijacks the DNS
 368  */
 369 static void
 370 rehijack(void *cls,
 371          struct GNUNET_SERVER_Client *client,
 372          const struct GNUNET_MessageHeader *message) {
 373     unhijack(dnsoutport);
 374     GNUNET_SCHEDULER_add_delayed(GNUNET_TIME_UNIT_SECONDS, hijack, NULL);
 375
 376     GNUNET_SERVER_receive_done(client, GNUNET_OK);
 377 }
 378
 379 /**
 380  * This receives the dns-payload from the daemon-vpn and sends it on over the udp-socket
 381  */
 382 static void
 383 receive_query(void *cls,
 384               struct GNUNET_SERVER_Client *client,
 385               const struct GNUNET_MessageHeader *message) {
 386     struct query_packet* pkt = (struct query_packet*)message;
 387     struct dns_pkt* dns = (struct dns_pkt*)pkt->data;
 388     struct dns_pkt_parsed* pdns = parse_dns_packet(dns);
 389
 390     query_states[dns->s.id].valid = GNUNET_YES;
 391     query_states[dns->s.id].client = client;
 392     query_states[dns->s.id].local_ip = pkt->orig_from;
 393     query_states[dns->s.id].local_port = pkt->src_port;
 394     query_states[dns->s.id].remote_ip = pkt->orig_to;
 395     query_states[dns->s.id].namelen = strlen((char*)dns->data) + 1;
 396     query_states[dns->s.id].name = GNUNET_malloc(query_states[dns->s.id].namelen);
 397     memcpy(query_states[dns->s.id].name, dns->data, query_states[dns->s.id].namelen);
 398
 399     /* The query is for a .gnunet-address */
 400     if (pdns->queries[0]->namelen > 9 &&
 401         0 == strncmp(pdns->queries[0]->name+(pdns->queries[0]->namelen - 9), ".gnunet.", 9))
 402       {
 403         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Query for .gnunet!\n");
 404         GNUNET_HashCode key;
 405         GNUNET_CRYPTO_hash(pdns->queries[0]->name, pdns->queries[0]->namelen, &key);
 406
 407         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
 408                    "Getting with key %08x, len is %d\n",
 409                    *((unsigned int*)&key),
 410                    pdns->queries[0]->namelen);
 411
 412         struct receive_dht_cls* cls = GNUNET_malloc(sizeof(struct receive_dht_cls));
 413         cls->id = dns->s.id;
 414
 415         cls->handle = GNUNET_DHT_get_start(dht,
 416                                            GNUNET_TIME_UNIT_MINUTES,
 417                                            GNUNET_BLOCK_TYPE_DNS,
 418                                            &key,
 419                                            DEFAULT_GET_REPLICATION,
 420                                            GNUNET_DHT_RO_NONE,
 421                                            NULL,
 422                                            0,
 423                                            NULL,
 424                                            0,
 425                                            receive_dht,
 426                                            cls);
 427
 428         goto outfree;
 429       }
 430
 431     GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Query for '%s'; namelen=%d\n", pdns->queries[0]->name, pdns->queries[0]->namelen);
 432     /* The query is for a PTR of a previosly resolved virtual IP */
 433     if (htons(pdns->queries[0]->qtype) == 12 &&
 434         74 == pdns->queries[0]->namelen)
 435       {
 436         char* ipv6addr;
 437         char ipv6[16];
 438         char ipv6rev[74] = "X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.ip6.arpa.";
 439         unsigned int i;
 440         unsigned long long ipv6prefix;
 441         unsigned int comparelen;
 442
 443         GNUNET_assert(GNUNET_OK == GNUNET_CONFIGURATION_get_value_string(cfg, "vpn", "IPV6ADDR", &ipv6addr));
 444         inet_pton (AF_INET6, ipv6addr, ipv6);
 445         GNUNET_free(ipv6addr);
 446
 447         GNUNET_assert(GNUNET_OK == GNUNET_CONFIGURATION_get_value_number(cfg, "vpn", "IPV6PREFIX", &ipv6prefix));
 448         GNUNET_assert(ipv6prefix < 127);
 449         ipv6prefix = (ipv6prefix + 7)/8;
 450
 451         for (i = ipv6prefix; i < 16; i++)
 452           ipv6[i] = 0;
 453
 454         for (i = 0; i < 16; i++)
 455           {
 456             unsigned char c1 = ipv6[i] >> 4;
 457             unsigned char c2 = ipv6[i] & 0xf;
 458
 459             if (c1 <= 9)
 460               ipv6rev[62-(4*i)] = c1 + '0';
 461             else
 462               ipv6rev[62-(4*i)] = c1 + 87; /* 87 is the difference between 'a' and 10 */
 463
 464             if (c2 <= 9)
 465               ipv6rev[62-((4*i)+2)] = c2 + '0';
 466             else
 467               ipv6rev[62-((4*i)+2)] = c2 + 87;
 468           }
 469         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "My network is %s'.\n", ipv6rev);
 470         comparelen = 10 + 4*ipv6prefix;
 471         if(0 == strncmp(pdns->queries[0]->name+(pdns->queries[0]->namelen - comparelen),
 472                         ipv6rev + (74 - comparelen),
 473                         comparelen))
 474           {
 475             GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Reverse-Query for .gnunet!\n");
 476
 477             GNUNET_SCHEDULER_add_now(send_rev_query, pdns);
 478
 479             goto out;
 480           }
 481       }
 482
 483     /* The query should be sent to the network */
 484
 485     struct sockaddr_in dest;
 486     memset(&dest, 0, sizeof dest);
 487     dest.sin_port = htons(53);
 488     dest.sin_addr.s_addr = pkt->orig_to;
 489
 490     GNUNET_NETWORK_socket_sendto(dnsout,
 491                                  dns,
 492                                  ntohs(pkt->hdr.size) - sizeof(struct query_packet) + 1,
 493                                  (struct sockaddr*) &dest,
 494                                  sizeof dest);
 495
 496 outfree:
 497     free_parsed_dns_packet(pdns);
 498     pdns = NULL;
 499 out:
 500     GNUNET_SERVER_receive_done(client, GNUNET_OK);
 501 }
 502
 503 /**
 504  * Read a response-packet of the UDP-Socket
 505  */
 506 static void
 507 read_response (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) {
 508     unsigned char buf[65536];
 509     struct dns_pkt* dns = (struct dns_pkt*)buf;
 510
 511     if (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)
 512       return;
 513
 514     struct sockaddr_in addr;
 515     memset(&addr, 0, sizeof addr);
 516     socklen_t addrlen = sizeof addr;
 517
 518     int r;
 519     r = GNUNET_NETWORK_socket_recvfrom(dnsout,
 520                                        buf,
 521                                        65536,
 522                                        (struct sockaddr*)&addr,
 523                                        &addrlen);
 524
 525     /* if (r < 0) FIXME */
 526
 527     if (query_states[dns->s.id].valid == GNUNET_YES) {
 528         query_states[dns->s.id].valid = GNUNET_NO;
 529
 530         size_t len = sizeof(struct answer_packet) + r - 1; /* 1 for the unsigned char data[1]; */
 531         struct answer_packet_list* answer = GNUNET_malloc(len + 2*sizeof(struct answer_packet_list*));
 532         answer->pkt.hdr.type = htons(GNUNET_MESSAGE_TYPE_LOCAL_RESPONSE_DNS);
 533         answer->pkt.hdr.size = htons(len);
 534         answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_IP;
 535         answer->pkt.from = addr.sin_addr.s_addr;
 536         answer->pkt.to = query_states[dns->s.id].local_ip;
 537         answer->pkt.dst_port = query_states[dns->s.id].local_port;
 538         memcpy(answer->pkt.data, buf, r);
 539
 540         GNUNET_CONTAINER_DLL_insert_after(head, tail, tail, answer);
 541
 542         GNUNET_SERVER_notify_transmit_ready(query_states[dns->s.id].client,
 543                                             len,
 544                                             GNUNET_TIME_UNIT_FOREVER_REL,
 545                                             &send_answer,
 546                                             query_states[dns->s.id].client);
 547     }
 548
 549     GNUNET_SCHEDULER_add_read_net(GNUNET_TIME_UNIT_FOREVER_REL,
 550                                   dnsout,
 551                                   &read_response,
 552                                   NULL);
 553 }
 554
 555
 556 /**
 557  * Task run during shutdown.
 558  *
 559  * @param cls unused
 560  * @param tc unused
 561  */
 562 static void
 563 cleanup_task (void *cls,
 564               const struct GNUNET_SCHEDULER_TaskContext *tc)
 565 {
 566   unhijack(dnsoutport);
 567   GNUNET_DHT_disconnect(dht);
 568 }
 569
 570 /**
 571  * Publish a DNS-record in the DHT. This is up to now just for testing.
 572  */
 573 static void
 574 publish_name (void *cls,
 575               const struct GNUNET_SCHEDULER_TaskContext *tc) {
 576     if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
 577       return;
 578
 579     char* name = "philipptoelke.gnunet.";
 580     size_t size = sizeof(struct GNUNET_DNS_Record);
 581     struct GNUNET_DNS_Record data;
 582     memset(&data, 0, size);
 583
 584     data.purpose.size = htonl(size - sizeof(struct GNUNET_CRYPTO_RsaSignature));
 585     data.purpose.purpose = GNUNET_SIGNATURE_PURPOSE_DNS_RECORD;
 586
 587     GNUNET_CRYPTO_hash(name, strlen(name)+1, &data.service_descriptor);
 588     GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Store with key1 %x\n", *((unsigned long long*)&data.service_descriptor));
 589
 590     data.service_type = htonl(GNUNET_DNS_SERVICE_TYPE_UDP);
 591     data.ports = htons(69);
 592
 593     char* keyfile;
 594     if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_filename(cfg, "GNUNETD",
 595                                                              "HOSTKEY", &keyfile))
 596       {
 597         GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "could not read keyfile-value\n");
 598         if (keyfile != NULL) GNUNET_free(keyfile);
 599         return;
 600       }
 601
 602     struct GNUNET_CRYPTO_RsaPrivateKey *my_private_key = GNUNET_CRYPTO_rsa_key_create_from_file(keyfile);
 603     GNUNET_free(keyfile);
 604     GNUNET_assert(my_private_key != NULL);
 605
 606     GNUNET_CRYPTO_rsa_key_get_public(my_private_key, &data.peer);
 607
 608     data.expiration_time = GNUNET_TIME_relative_to_absolute(GNUNET_TIME_UNIT_HOURS);
 609
 610   /* Sign the block */
 611     if (GNUNET_OK != GNUNET_CRYPTO_rsa_sign(my_private_key,
 612                                             &data.purpose,
 613                                             &data.signature))
 614       {
 615         GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "could not sign DNS_Record\n");
 616         return;
 617       }
 618     GNUNET_CRYPTO_rsa_key_free(my_private_key);
 619
 620     GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
 621                "Putting with key %08x, size = %d\n",
 622                *((unsigned int*)&data.service_descriptor),
 623                size);
 624
 625     GNUNET_DHT_put(dht,
 626                    &data.service_descriptor,
 627                    DEFAULT_PUT_REPLICATION,
 628                    GNUNET_DHT_RO_NONE,
 629                    GNUNET_BLOCK_TYPE_DNS,
 630                    size,
 631                    (char*)&data,
 632                    GNUNET_TIME_relative_to_absolute(GNUNET_TIME_UNIT_HOURS),
 633                    GNUNET_TIME_UNIT_MINUTES,
 634                    NULL,
 635                    NULL);
 636
 637     GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_HOURS,
 638                                   publish_name,
 639                                   NULL);
 640 }
 641
 642 /**
 643  * @param cls closure
 644  * @param server the initialized server
 645  * @param cfg_ configuration to use
 646  */
 647 static void
 648 run (void *cls,
 649      struct GNUNET_SERVER_Handle *server,
 650      const struct GNUNET_CONFIGURATION_Handle *cfg_)
 651 {
 652   static const struct GNUNET_SERVER_MessageHandler handlers[] = {
 653       /* callback, cls, type, size */
 654         {&receive_query, NULL, GNUNET_MESSAGE_TYPE_LOCAL_QUERY_DNS, 0},
 655         {&rehijack, NULL, GNUNET_MESSAGE_TYPE_REHIJACK, sizeof(struct GNUNET_MessageHeader)},
 656         {NULL, NULL, 0, 0}
 657   };
 658
 659   cfg = cfg_;
 660
 661   unsigned int i;
 662   for (i = 0; i < 65536; i++) {
 663       query_states[i].valid = GNUNET_NO;
 664   }
 665
 666   dht = GNUNET_DHT_connect(cfg, 1024);
 667
 668   struct sockaddr_in addr;
 669
 670   dnsout = GNUNET_NETWORK_socket_create (AF_INET, SOCK_DGRAM, 0);
 671   if (dnsout == NULL)
 672     return;
 673   memset(&addr, 0, sizeof(struct sockaddr_in));
 674
 675   int err = GNUNET_NETWORK_socket_bind (dnsout,
 676                                         (struct sockaddr*)&addr,
 677                                         sizeof(struct sockaddr_in));
 678
 679   if (err != GNUNET_YES) {
 680       GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "Could not bind a port, exiting\n");
 681       return;
 682   }
 683
 684   /* Read the port we bound to */
 685   socklen_t addrlen = sizeof(struct sockaddr_in);
 686   err = getsockname(GNUNET_NETWORK_get_fd(dnsout),
 687                     (struct sockaddr*) &addr,
 688                     &addrlen);
 689
 690   dnsoutport = htons(addr.sin_port);
 691
 692   GNUNET_SCHEDULER_add_now (publish_name, NULL);
 693
 694   GNUNET_SCHEDULER_add_read_net(GNUNET_TIME_UNIT_FOREVER_REL, dnsout, &read_response, NULL);
 695
 696   GNUNET_SERVER_add_handlers (server, handlers);
 697   GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
 698                                 &cleanup_task,
 699                                 cls);
 700 }
 701
 702 /**
 703  * The main function for the dns service.
 704  *
 705  * @param argc number of arguments from the command line
 706  * @param argv command line arguments
 707  * @return 0 ok, 1 on error
 708  */
 709 int
 710 main (int argc, char *const *argv)
 711 {
 712   return (GNUNET_OK ==
 713           GNUNET_SERVICE_run (argc,
 714                               argv,
 715                               "dns",
 716                               GNUNET_SERVICE_OPTION_NONE,
 717                               &run, NULL)) ? 0 : 1;
 718 }