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_applications.h"
  33 #include "gnunet-vpn-packet.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_mesh_service.h"
  41 #include "gnunet_signatures.h"
  42
  43 struct GNUNET_MESH_Handle *mesh_handle;
  44
  45 /**
  46  * The UDP-Socket through which DNS-Resolves will be sent if they are not to be
  47  * sent through gnunet. The port of this socket will not be hijacked.
  48  */
  49 static struct GNUNET_NETWORK_Handle *dnsout;
  50
  51 /**
  52  * The port bound to the socket dnsout
  53  */
  54 static unsigned short dnsoutport;
  55
  56 /**
  57  * A handle to the DHT-Service
  58  */
  59 static struct GNUNET_DHT_Handle *dht;
  60
  61 /**
  62  * The configuration to use
  63  */
  64 static const struct GNUNET_CONFIGURATION_Handle *cfg;
  65
  66 /**
  67  * The handle to the service-configuration
  68  */
  69 static struct GNUNET_CONFIGURATION_Handle *servicecfg;
  70
  71 /**
  72  * A list of DNS-Responses that have to be sent to the requesting client
  73  */
  74 static struct answer_packet_list *head;
  75
  76 /**
  77  * The tail of the list of DNS-responses
  78  */
  79 static struct answer_packet_list *tail;
  80
  81 /**
  82  * A structure containing a mapping from network-byte-ordered DNS-id (16 bit) to
  83  * some information needed to handle this query
  84  *
  85  * It currently allocates at least
  86  * (1 + machine-width + 32 + 32 + 16 + machine-width + 8) * 65536 bit
  87  * = 1.7 MiB on 64 bit.
  88  * = 1.2 MiB on 32 bit.
  89  */
  90 static struct {
  91     unsigned valid:1;
  92     struct GNUNET_SERVER_Client* client;
  93     uint32_t local_ip;
  94     uint32_t remote_ip;
  95     uint16_t local_port;
  96     char* name;
  97     uint8_t namelen;
  98 } query_states[UINT16_MAX];
  99
 100 /**
 101  * A struct used to give more than one value as
 102  * closure to receive_dht
 103  */
 104 struct receive_dht_cls {
 105     uint16_t id;
 106     struct GNUNET_DHT_GetHandle* handle;
 107 };
 108
 109 /**
 110  * Hijack all outgoing DNS-Traffic but for traffic leaving "our" port.
 111  */
 112 static void
 113 hijack (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
 114 {
 115   char port_s[6];
 116   char *virt_dns;
 117   struct GNUNET_OS_Process *proc;
 118
 119   if (GNUNET_SYSERR ==
 120       GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "VIRTDNS",
 121                                              &virt_dns))
 122     {
 123       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 124                   "No entry 'VIRTDNS' in configuration!\n");
 125       exit (1);
 126     }
 127
 128   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Hijacking, port is %d\n", dnsoutport);
 129   snprintf (port_s, 6, "%d", dnsoutport);
 130   if (NULL != (proc = GNUNET_OS_start_process (NULL,
 131                                                NULL,
 132                                                "gnunet-helper-hijack-dns",
 133                                                "gnunet-hijack-dns",
 134                                                port_s, virt_dns, NULL)))
 135     GNUNET_OS_process_close (proc);
 136   GNUNET_free (virt_dns);
 137 }
 138
 139 /**
 140  * Delete the hijacking-routes
 141  */
 142 static void
 143 unhijack (unsigned short port)
 144 {
 145   char port_s[6];
 146   char *virt_dns;
 147   struct GNUNET_OS_Process *proc;
 148
 149   if (GNUNET_SYSERR ==
 150       GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "VIRTDNS",
 151                                              &virt_dns))
 152     {
 153       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 154                   "No entry 'VIRTDNS' in configuration!\n");
 155       exit (1);
 156     }
 157
 158   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "unHijacking, port is %d\n", port);
 159   snprintf (port_s, 6, "%d", port);
 160   if (NULL != (proc = GNUNET_OS_start_process (NULL,
 161                                                NULL,
 162                                                "gnunet-helper-hijack-dns",
 163                                                "gnunet-hijack-dns",
 164                                                "-d", port_s, virt_dns, NULL)))
 165     GNUNET_OS_process_close (proc);
 166   GNUNET_free (virt_dns);
 167 }
 168
 169 /**
 170  * Send the DNS-Response to the client. Gets called via the notify_transmit_ready-
 171  * system.
 172  */
 173 static size_t
 174 send_answer(void* cls, size_t size, void* buf) {
 175     struct answer_packet_list* query = head;
 176     size_t len = ntohs(query->pkt.hdr.size);
 177
 178     GNUNET_assert(len <= size);
 179
 180     memcpy(buf, &query->pkt.hdr, len);
 181
 182     GNUNET_CONTAINER_DLL_remove (head, tail, query);
 183
 184     GNUNET_free(query);
 185
 186     /* When more data is to be sent, reschedule */
 187     if (head != NULL)
 188       GNUNET_SERVER_notify_transmit_ready(cls,
 189                                           ntohs(head->pkt.hdr.size),
 190                                           GNUNET_TIME_UNIT_FOREVER_REL,
 191                                           &send_answer,
 192                                           cls);
 193
 194     return len;
 195 }
 196
 197 struct tunnel_cls {
 198     struct GNUNET_MESH_Tunnel *tunnel;
 199     struct GNUNET_MessageHeader hdr;
 200     struct dns_pkt dns;
 201 };
 202
 203 struct tunnel_cls *remote_pending[UINT16_MAX];
 204
 205
 206 static size_t
 207 mesh_send (void *cls, size_t size, void *buf)
 208 {
 209   struct tunnel_cls *cls_ = (struct tunnel_cls *) cls;
 210
 211   GNUNET_assert(cls_->hdr.size <= size);
 212
 213   size = cls_->hdr.size;
 214   cls_->hdr.size = htons(cls_->hdr.size);
 215
 216   memcpy(buf, &cls_->hdr, size);
 217   return size;
 218 }
 219
 220
 221 void mesh_connect (void* cls, const struct GNUNET_PeerIdentity* peer, const struct GNUNET_TRANSPORT_ATS_Information *atsi) {
 222   GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Connected to peer %x\n", *((unsigned long*)peer));
 223   struct tunnel_cls *cls_ = (struct tunnel_cls*)cls;
 224
 225   GNUNET_MESH_notify_transmit_ready(cls_->tunnel,
 226                                     GNUNET_YES,
 227                                     42,
 228                                     GNUNET_TIME_UNIT_MINUTES,
 229                                     NULL,
 230                                     cls_->hdr.size,
 231                                     mesh_send,
 232                                     cls);
 233 }
 234
 235
 236 static void
 237 send_mesh_query (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
 238 {
 239   if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
 240     return;
 241
 242   struct tunnel_cls *cls_ = (struct tunnel_cls*)cls;
 243
 244   cls_->tunnel = GNUNET_MESH_peer_request_connect_by_type(mesh_handle,
 245                                            GNUNET_TIME_UNIT_HOURS,
 246                                            GNUNET_APPLICATION_TYPE_INTERNET_RESOLVER,
 247                                            mesh_connect,
 248                                            NULL,
 249                                            cls_);
 250
 251   remote_pending[cls_->dns.s.id] = cls_;
 252
 253   /* TODO
 254    * at receive: walk through pending list, send answer
 255    */
 256 }
 257
 258 static void
 259 send_rev_query(void * cls, const struct GNUNET_SCHEDULER_TaskContext *tc) {
 260     if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
 261       return;
 262
 263     struct dns_pkt_parsed* pdns = (struct dns_pkt_parsed*) cls;
 264
 265     unsigned short id = pdns->s.id;
 266
 267     free_parsed_dns_packet(pdns);
 268
 269     if (query_states[id].valid != GNUNET_YES) return;
 270     query_states[id].valid = GNUNET_NO;
 271
 272     GNUNET_assert(query_states[id].namelen == 74);
 273
 274     size_t len = sizeof(struct answer_packet) - 1 \
 275                  + sizeof(struct dns_static) \
 276                  + 74 /* this is the length of a reverse ipv6-lookup */ \
 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                  - 2 /* We do not know the lenght of the answer yet*/;
 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_REV;
 288
 289     answer->pkt.from = query_states[id].remote_ip;
 290
 291     answer->pkt.to = query_states[id].local_ip;
 292     answer->pkt.dst_port = query_states[id].local_port;
 293
 294     struct dns_pkt *dpkt = (struct dns_pkt*)answer->pkt.data;
 295
 296     dpkt->s.id = id;
 297     dpkt->s.aa = 1;
 298     dpkt->s.qr = 1;
 299     dpkt->s.ra = 1;
 300     dpkt->s.qdcount = htons(1);
 301     dpkt->s.ancount = htons(1);
 302
 303     memcpy(dpkt->data, query_states[id].name, query_states[id].namelen);
 304     GNUNET_free(query_states[id].name);
 305
 306     struct dns_query_line* dque = (struct dns_query_line*)(dpkt->data+(query_states[id].namelen));
 307     dque->type = htons(12); /* PTR */
 308     dque->class = htons(1); /* IN */
 309
 310     char* anname = (char*)(dpkt->data+(query_states[id].namelen)+sizeof(struct dns_query_line));
 311     memcpy(anname, "\xc0\x0c", 2);
 312
 313     struct dns_record_line *drec_data = (struct dns_record_line*)(dpkt->data+(query_states[id].namelen)+sizeof(struct dns_query_line)+2);
 314     drec_data->type = htons(12); /* AAAA */
 315     drec_data->class = htons(1); /* IN */
 316     /* FIXME: read the TTL from block:
 317      * GNUNET_TIME_absolute_get_remaining(rec->expiration_time)
 318      *
 319      * But how to get the seconds out of this?
 320      */
 321     drec_data->ttl = htonl(3600);
 322
 323     /* Calculate at which offset in the packet the length of the name and the
 324      * name, it is filled in by the daemon-vpn */
 325     answer->pkt.addroffset = htons((unsigned short)((unsigned long)(&drec_data->data_len)-(unsigned long)(&answer->pkt)));
 326
 327     GNUNET_CONTAINER_DLL_insert_after(head, tail, tail, answer);
 328
 329     GNUNET_SERVER_notify_transmit_ready(query_states[id].client,
 330                                         len,
 331                                         GNUNET_TIME_UNIT_FOREVER_REL,
 332                                         &send_answer,
 333                                         query_states[id].client);
 334 }
 335
 336 /**
 337  * Receive a block from the dht.
 338  */
 339 static void
 340 receive_dht(void *cls,
 341             struct GNUNET_TIME_Absolute exp,
 342             const GNUNET_HashCode *key,
 343             const struct GNUNET_PeerIdentity *const *get_path,
 344             const struct GNUNET_PeerIdentity *const *put_path,
 345             enum GNUNET_BLOCK_Type type,
 346             size_t size,
 347             const void *data) {
 348
 349     unsigned short id = ((struct receive_dht_cls*)cls)->id;
 350     struct GNUNET_DHT_GetHandle* handle = ((struct receive_dht_cls*)cls)->handle;
 351     GNUNET_free(cls);
 352
 353     GNUNET_assert(type == GNUNET_BLOCK_TYPE_DNS);
 354
 355     /* If no query with this id is pending, ignore the block */
 356     if (query_states[id].valid != GNUNET_YES) return;
 357     query_states[id].valid = GNUNET_NO;
 358
 359     const struct GNUNET_DNS_Record* rec = data;
 360     GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
 361                "Got block of size %d, peer: %08x, desc: %08x\n",
 362                size,
 363                *((unsigned int*)&rec->peer),
 364                *((unsigned int*)&rec->service_descriptor));
 365
 366     size_t len = sizeof(struct answer_packet) - 1 \
 367                  + sizeof(struct dns_static) \
 368                  + query_states[id].namelen \
 369                  + sizeof(struct dns_query_line) \
 370                  + 2 /* To hold the pointer (as defined in RFC1035) to the name */ \
 371                  + sizeof(struct dns_record_line) - 1 \
 372                  + 16; /* To hold the IPv6-Address */
 373
 374     struct answer_packet_list* answer = GNUNET_malloc(len + 2*sizeof(struct answer_packet_list*));
 375     memset(answer, 0, len + 2*sizeof(struct answer_packet_list*));
 376
 377     answer->pkt.hdr.type = htons(GNUNET_MESSAGE_TYPE_LOCAL_RESPONSE_DNS);
 378     answer->pkt.hdr.size = htons(len);
 379     answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_SERVICE;
 380
 381     GNUNET_CRYPTO_hash(&rec->peer,
 382                        sizeof(struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
 383                        &answer->pkt.service_descr.peer);
 384
 385     memcpy(&answer->pkt.service_descr.service_descriptor,
 386            &rec->service_descriptor,
 387            sizeof(GNUNET_HashCode));
 388     memcpy(&answer->pkt.service_descr.service_type,
 389            &rec->service_type,
 390            sizeof(answer->pkt.service_descr.service_type));
 391     memcpy(&answer->pkt.service_descr.ports, &rec->ports, sizeof(answer->pkt.service_descr.ports));
 392
 393     answer->pkt.from = query_states[id].remote_ip;
 394
 395     answer->pkt.to = query_states[id].local_ip;
 396     answer->pkt.dst_port = query_states[id].local_port;
 397
 398     struct dns_pkt *dpkt = (struct dns_pkt*)answer->pkt.data;
 399
 400     dpkt->s.id = id;
 401     dpkt->s.aa = 1;
 402     dpkt->s.qr = 1;
 403     dpkt->s.ra = 1;
 404     dpkt->s.qdcount = htons(1);
 405     dpkt->s.ancount = htons(1);
 406
 407     memcpy(dpkt->data, query_states[id].name, query_states[id].namelen);
 408     GNUNET_free(query_states[id].name);
 409
 410     struct dns_query_line* dque = (struct dns_query_line*)(dpkt->data+(query_states[id].namelen));
 411     dque->type = htons(28); /* AAAA */
 412     dque->class = htons(1); /* IN */
 413
 414     char* anname = (char*)(dpkt->data+(query_states[id].namelen)+sizeof(struct dns_query_line));
 415     memcpy(anname, "\xc0\x0c", 2);
 416
 417     struct dns_record_line *drec_data = (struct dns_record_line*)(dpkt->data+(query_states[id].namelen)+sizeof(struct dns_query_line)+2);
 418     drec_data->type = htons(28); /* AAAA */
 419     drec_data->class = htons(1); /* IN */
 420
 421     /* FIXME: read the TTL from block:
 422      * GNUNET_TIME_absolute_get_remaining(rec->expiration_time)
 423      *
 424      * But how to get the seconds out of this?
 425      */
 426     drec_data->ttl = htonl(3600);
 427     drec_data->data_len = htons(16);
 428
 429     /* Calculate at which offset in the packet the IPv6-Address belongs, it is
 430      * filled in by the daemon-vpn */
 431     answer->pkt.addroffset = htons((unsigned short)((unsigned long)(&drec_data->data)-(unsigned long)(&answer->pkt)));
 432
 433     GNUNET_CONTAINER_DLL_insert_after(head, tail, tail, answer);
 434
 435     GNUNET_SERVER_notify_transmit_ready(query_states[id].client,
 436                                         len,
 437                                         GNUNET_TIME_UNIT_FOREVER_REL,
 438                                         &send_answer,
 439                                         query_states[id].client);
 440
 441     GNUNET_DHT_get_stop(handle);
 442 }
 443
 444 /**
 445  * This receives a GNUNET_MESSAGE_TYPE_REHIJACK and rehijacks the DNS
 446  */
 447 static void
 448 rehijack(void *cls,
 449          struct GNUNET_SERVER_Client *client,
 450          const struct GNUNET_MessageHeader *message) {
 451     unhijack(dnsoutport);
 452     GNUNET_SCHEDULER_add_delayed(GNUNET_TIME_UNIT_SECONDS, hijack, NULL);
 453
 454     GNUNET_SERVER_receive_done(client, GNUNET_OK);
 455 }
 456
 457 /**
 458  * This receives the dns-payload from the daemon-vpn and sends it on over the udp-socket
 459  */
 460 static void
 461 receive_query(void *cls,
 462               struct GNUNET_SERVER_Client *client,
 463               const struct GNUNET_MessageHeader *message) {
 464     struct query_packet* pkt = (struct query_packet*)message;
 465     struct dns_pkt* dns = (struct dns_pkt*)pkt->data;
 466     struct dns_pkt_parsed* pdns = parse_dns_packet(dns);
 467
 468     query_states[dns->s.id].valid = GNUNET_YES;
 469     query_states[dns->s.id].client = client;
 470     query_states[dns->s.id].local_ip = pkt->orig_from;
 471     query_states[dns->s.id].local_port = pkt->src_port;
 472     query_states[dns->s.id].remote_ip = pkt->orig_to;
 473     query_states[dns->s.id].namelen = strlen((char*)dns->data) + 1;
 474     query_states[dns->s.id].name = GNUNET_malloc(query_states[dns->s.id].namelen);
 475     memcpy(query_states[dns->s.id].name, dns->data, query_states[dns->s.id].namelen);
 476
 477     /* The query is for a .gnunet-address */
 478     if (pdns->queries[0]->namelen > 9 &&
 479         0 == strncmp(pdns->queries[0]->name+(pdns->queries[0]->namelen - 9), ".gnunet.", 9))
 480       {
 481         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Query for .gnunet!\n");
 482         GNUNET_HashCode key;
 483         GNUNET_CRYPTO_hash(pdns->queries[0]->name, pdns->queries[0]->namelen, &key);
 484
 485         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
 486                    "Getting with key %08x, len is %d\n",
 487                    *((unsigned int*)&key),
 488                    pdns->queries[0]->namelen);
 489
 490         struct receive_dht_cls* cls = GNUNET_malloc(sizeof(struct receive_dht_cls));
 491         cls->id = dns->s.id;
 492
 493         cls->handle = GNUNET_DHT_get_start(dht,
 494                                            GNUNET_TIME_UNIT_MINUTES,
 495                                            GNUNET_BLOCK_TYPE_DNS,
 496                                            &key,
 497                                            DEFAULT_GET_REPLICATION,
 498                                            GNUNET_DHT_RO_NONE,
 499                                            NULL,
 500                                            0,
 501                                            NULL,
 502                                            0,
 503                                            receive_dht,
 504                                            cls);
 505
 506         goto outfree;
 507       }
 508
 509     GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Query for '%s'; namelen=%d\n", pdns->queries[0]->name, pdns->queries[0]->namelen);
 510
 511     /* This is a PTR-Query. Check if it is for "our" network */
 512     if (htons(pdns->queries[0]->qtype) == 12 &&
 513         74 == pdns->queries[0]->namelen)
 514       {
 515         char* ipv6addr;
 516         char ipv6[16];
 517         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.";
 518         unsigned int i;
 519         unsigned long long ipv6prefix;
 520         unsigned int comparelen;
 521
 522         GNUNET_assert(GNUNET_OK == GNUNET_CONFIGURATION_get_value_string(cfg, "vpn", "IPV6ADDR", &ipv6addr));
 523         inet_pton (AF_INET6, ipv6addr, ipv6);
 524         GNUNET_free(ipv6addr);
 525
 526         GNUNET_assert(GNUNET_OK == GNUNET_CONFIGURATION_get_value_number(cfg, "vpn", "IPV6PREFIX", &ipv6prefix));
 527         GNUNET_assert(ipv6prefix < 127);
 528         ipv6prefix = (ipv6prefix + 7)/8;
 529
 530         for (i = ipv6prefix; i < 16; i++)
 531           ipv6[i] = 0;
 532
 533         for (i = 0; i < 16; i++)
 534           {
 535             unsigned char c1 = ipv6[i] >> 4;
 536             unsigned char c2 = ipv6[i] & 0xf;
 537
 538             if (c1 <= 9)
 539               ipv6rev[62-(4*i)] = c1 + '0';
 540             else
 541               ipv6rev[62-(4*i)] = c1 + 87; /* 87 is the difference between 'a' and 10 */
 542
 543             if (c2 <= 9)
 544               ipv6rev[62-((4*i)+2)] = c2 + '0';
 545             else
 546               ipv6rev[62-((4*i)+2)] = c2 + 87;
 547           }
 548         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "My network is %s'.\n", ipv6rev);
 549         comparelen = 10 + 4*ipv6prefix;
 550         if(0 == strncmp(pdns->queries[0]->name+(pdns->queries[0]->namelen - comparelen),
 551                         ipv6rev + (74 - comparelen),
 552                         comparelen))
 553           {
 554             GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Reverse-Query for .gnunet!\n");
 555
 556             GNUNET_SCHEDULER_add_now(send_rev_query, pdns);
 557
 558             goto out;
 559           }
 560       }
 561
 562     char* virt_dns;
 563     int virt_dns_bytes;
 564     if (GNUNET_SYSERR ==
 565         GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "VIRTDNS",
 566                                                &virt_dns))
 567       {
 568         GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 569                     "No entry 'VIRTDNS' in configuration!\n");
 570         exit (1);
 571       }
 572
 573     if (1 != inet_pton (AF_INET, virt_dns, &virt_dns_bytes))
 574       {
 575         GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 576                     "Error parsing 'VIRTDNS': %s; %m!\n", virt_dns);
 577         exit(1);
 578       }
 579
 580     GNUNET_free(virt_dns);
 581
 582     if (virt_dns_bytes == pkt->orig_to)
 583       {
 584         /* This is a packet that was sent directly to the virtual dns-server
 585          *
 586          * This means we have to send this query over gnunet
 587          */
 588
 589         size_t size = sizeof(struct GNUNET_MESH_Tunnel*) + sizeof(struct GNUNET_MessageHeader) + (ntohs(message->size) - sizeof(struct query_packet) + 1);
 590         struct tunnel_cls *cls_ =  GNUNET_malloc(size);
 591         cls_->hdr.size = size - sizeof(struct GNUNET_MESH_Tunnel*);
 592
 593         cls_->hdr.type = ntohs(GNUNET_MESSAGE_TYPE_REMOTE_QUERY_DNS);
 594
 595         memcpy(&cls_->dns, dns, cls_->hdr.size);
 596         GNUNET_SCHEDULER_add_now(send_mesh_query, cls_);
 597
 598         goto out;
 599       }
 600
 601
 602     /* The query should be sent to the network */
 603
 604     struct sockaddr_in dest;
 605     memset(&dest, 0, sizeof dest);
 606     dest.sin_port = htons(53);
 607     dest.sin_addr.s_addr = pkt->orig_to;
 608
 609     GNUNET_NETWORK_socket_sendto(dnsout,
 610                                  dns,
 611                                  ntohs(pkt->hdr.size) - sizeof(struct query_packet) + 1,
 612                                  (struct sockaddr*) &dest,
 613                                  sizeof dest);
 614
 615 outfree:
 616     free_parsed_dns_packet(pdns);
 617     pdns = NULL;
 618 out:
 619     GNUNET_SERVER_receive_done(client, GNUNET_OK);
 620 }
 621
 622 static void read_response (void *cls,
 623                            const struct GNUNET_SCHEDULER_TaskContext *tc);
 624
 625 static void
 626 open_port ()
 627 {
 628   struct sockaddr_in addr;
 629
 630   dnsout = GNUNET_NETWORK_socket_create (AF_INET, SOCK_DGRAM, 0);
 631   if (dnsout == NULL)
 632     return;
 633   memset (&addr, 0, sizeof (struct sockaddr_in));
 634
 635   int err = GNUNET_NETWORK_socket_bind (dnsout,
 636                                         (struct sockaddr *) &addr,
 637                                         sizeof (struct sockaddr_in));
 638
 639   if (err != GNUNET_YES)
 640     {
 641       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 642                   "Could not bind a port, exiting\n");
 643       return;
 644     }
 645
 646   /* Read the port we bound to */
 647   socklen_t addrlen = sizeof (struct sockaddr_in);
 648   err = getsockname (GNUNET_NETWORK_get_fd (dnsout),
 649                      (struct sockaddr *) &addr, &addrlen);
 650
 651   dnsoutport = htons (addr.sin_port);
 652
 653   GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL, dnsout,
 654                                  &read_response, NULL);
 655 }
 656
 657 /**
 658  * Read a response-packet of the UDP-Socket
 659  */
 660 static void
 661 read_response (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) {
 662     struct sockaddr_in addr;
 663     socklen_t addrlen = sizeof (addr);
 664     int r;
 665     int len;
 666
 667     if (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)
 668       return;
 669
 670     memset(&addr, 0, sizeof addr);
 671
 672 #ifndef MINGW
 673     if (0 != ioctl (GNUNET_NETWORK_get_fd (dnsout),
 674                     FIONREAD, &len))
 675       {
 676         unhijack(dnsoutport);
 677         open_port();
 678         GNUNET_SCHEDULER_add_delayed(GNUNET_TIME_UNIT_SECONDS, hijack, NULL);
 679         return;
 680       }
 681 #else
 682     /* port the code above? */
 683     len = 65536;
 684 #endif
 685     {
 686       unsigned char buf[len];
 687       struct dns_pkt* dns = (struct dns_pkt*)buf;
 688
 689       r = GNUNET_NETWORK_socket_recvfrom (dnsout,
 690                                           buf,
 691                                           sizeof (buf),
 692                                           (struct sockaddr*)&addr,
 693                                           &addrlen);
 694
 695       if (r < 0)
 696         {
 697           unhijack(dnsoutport);
 698           open_port();
 699           GNUNET_SCHEDULER_add_delayed(GNUNET_TIME_UNIT_SECONDS, hijack, NULL);
 700           return;
 701         }
 702
 703       if (query_states[dns->s.id].valid == GNUNET_YES)
 704         {
 705           query_states[dns->s.id].valid = GNUNET_NO;
 706
 707           size_t len = sizeof(struct answer_packet) + r - 1; /* 1 for the unsigned char data[1]; */
 708           struct answer_packet_list* answer = GNUNET_malloc(len + 2*sizeof(struct answer_packet_list*));
 709           answer->pkt.hdr.type = htons(GNUNET_MESSAGE_TYPE_LOCAL_RESPONSE_DNS);
 710           answer->pkt.hdr.size = htons(len);
 711           answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_IP;
 712           answer->pkt.from = addr.sin_addr.s_addr;
 713           answer->pkt.to = query_states[dns->s.id].local_ip;
 714           answer->pkt.dst_port = query_states[dns->s.id].local_port;
 715           memcpy(answer->pkt.data, buf, r);
 716
 717           GNUNET_CONTAINER_DLL_insert_after(head, tail, tail, answer);
 718
 719           GNUNET_SERVER_notify_transmit_ready(query_states[dns->s.id].client,
 720                                               len,
 721                                               GNUNET_TIME_UNIT_FOREVER_REL,
 722                                               &send_answer,
 723                                               query_states[dns->s.id].client);
 724         }
 725     }
 726     GNUNET_SCHEDULER_add_read_net(GNUNET_TIME_UNIT_FOREVER_REL,
 727                                   dnsout,
 728                                   &read_response,
 729                                   NULL);
 730 }
 731
 732
 733 /**
 734  * Task run during shutdown.
 735  *
 736  * @param cls unused
 737  * @param tc unused
 738  */
 739 static void
 740 cleanup_task (void *cls,
 741               const struct GNUNET_SCHEDULER_TaskContext *tc)
 742 {
 743   unhijack(dnsoutport);
 744   GNUNET_DHT_disconnect(dht);
 745 }
 746
 747 /**
 748  * @brief Create a port-map from udp and tcp redirects
 749  *
 750  * @param udp_redirects
 751  * @param tcp_redirects
 752  *
 753  * @return
 754  */
 755 uint64_t
 756 get_port_from_redirects (const char *udp_redirects, const char *tcp_redirects)
 757 {
 758   uint64_t ret = 0;
 759   char* cpy, *hostname, *redirect;
 760   int local_port, count = 0;
 761
 762   if (NULL != udp_redirects)
 763     {
 764       cpy = GNUNET_strdup (udp_redirects);
 765       for (redirect = strtok (cpy, " "); redirect != NULL; redirect = strtok (NULL, " "))
 766         {
 767           if (NULL == (hostname = strstr (redirect, ":")))
 768             {
 769               GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Warning: option %s is not formatted correctly!\n", redirect);
 770               continue;
 771             }
 772           hostname[0] = '\0';
 773           local_port = atoi (redirect);
 774           if (!((local_port > 0) && (local_port < 65536)))
 775             GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Warning: %s is not a correct port.", redirect);
 776
 777           ret |= (0xFFFF & htons(local_port));
 778           ret <<= 16;
 779           count ++;
 780
 781           if(count > 4)
 782             {
 783               ret = 0;
 784               goto out;
 785             }
 786         }
 787       GNUNET_free(cpy);
 788       cpy = NULL;
 789     }
 790
 791   if (NULL != tcp_redirects)
 792     {
 793       cpy = GNUNET_strdup (tcp_redirects);
 794       for (redirect = strtok (cpy, " "); redirect != NULL; redirect = strtok (NULL, " "))
 795         {
 796           if (NULL == (hostname = strstr (redirect, ":")))
 797             {
 798               GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Warning: option %s is not formatted correctly!\n", redirect);
 799               continue;
 800             }
 801           hostname[0] = '\0';
 802           local_port = atoi (redirect);
 803           if (!((local_port > 0) && (local_port < 65536)))
 804             GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Warning: %s is not a correct port.", redirect);
 805
 806           ret |= (0xFFFF & htons(local_port));
 807           ret <<= 16;
 808           count ++;
 809
 810           if(count > 4)
 811             {
 812               ret = 0;
 813               goto out;
 814             }
 815         }
 816       GNUNET_free(cpy);
 817       cpy = NULL;
 818     }
 819
 820 out:
 821   if (NULL != cpy)
 822     GNUNET_free(cpy);
 823   return ret;
 824 }
 825
 826 void
 827 publish_name (const char *name, uint64_t ports, uint32_t service_type,
 828               struct GNUNET_CRYPTO_RsaPrivateKey *my_private_key)
 829 {
 830   size_t size = sizeof (struct GNUNET_DNS_Record);
 831   struct GNUNET_DNS_Record data;
 832   memset (&data, 0, size);
 833
 834   data.purpose.size =
 835     htonl (size - sizeof (struct GNUNET_CRYPTO_RsaSignature));
 836   data.purpose.purpose = GNUNET_SIGNATURE_PURPOSE_DNS_RECORD;
 837
 838   GNUNET_CRYPTO_hash (name, strlen (name) + 1, &data.service_descriptor);
 839   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Store with key1 %x\n",
 840               *((unsigned long long *) &data.service_descriptor));
 841
 842   data.service_type = service_type;
 843   data.ports = ports;
 844
 845   GNUNET_CRYPTO_rsa_key_get_public (my_private_key, &data.peer);
 846
 847   data.expiration_time =
 848     GNUNET_TIME_relative_to_absolute (GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_HOURS, 2));
 849
 850   /* Sign the block */
 851   if (GNUNET_OK != GNUNET_CRYPTO_rsa_sign (my_private_key,
 852                                            &data.purpose, &data.signature))
 853     {
 854       GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "could not sign DNS_Record\n");
 855       return;
 856     }
 857
 858   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 859               "Putting with key %08x, size = %d\n",
 860               *((unsigned int *) &data.service_descriptor), size);
 861
 862   GNUNET_DHT_put (dht,
 863                   &data.service_descriptor,
 864                   DEFAULT_PUT_REPLICATION,
 865                   GNUNET_DHT_RO_NONE,
 866                   GNUNET_BLOCK_TYPE_DNS,
 867                   size,
 868                   (char *) &data,
 869                   GNUNET_TIME_relative_to_absolute (GNUNET_TIME_UNIT_HOURS),
 870                   GNUNET_TIME_UNIT_MINUTES, NULL, NULL);
 871 }
 872
 873 /**
 874  * @brief Publishes the record defined by the section section
 875  *
 876  * @param cls closure
 877  * @param section the current section
 878  */
 879 void
 880 publish_iterate (void *cls, const char *section)
 881 {
 882   char *udp_redirects, *tcp_redirects, *alternative_names, *alternative_name,
 883     *keyfile;
 884
 885   GNUNET_CONFIGURATION_get_value_string (servicecfg, section,
 886                                          "UDP_REDIRECTS", &udp_redirects);
 887   GNUNET_CONFIGURATION_get_value_string (servicecfg, section, "TCP_REDIRECTS",
 888                                          &tcp_redirects);
 889
 890   if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_filename (cfg, "GNUNETD",
 891                                                             "HOSTKEY",
 892                                                             &keyfile))
 893     {
 894       GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "could not read keyfile-value\n");
 895       if (keyfile != NULL)
 896         GNUNET_free (keyfile);
 897       return;
 898     }
 899
 900   struct GNUNET_CRYPTO_RsaPrivateKey *my_private_key =
 901     GNUNET_CRYPTO_rsa_key_create_from_file (keyfile);
 902   GNUNET_free (keyfile);
 903   GNUNET_assert (my_private_key != NULL);
 904
 905   uint64_t ports = get_port_from_redirects (udp_redirects, tcp_redirects);
 906   uint32_t service_type = 0;
 907
 908   if (NULL != udp_redirects)
 909     service_type = GNUNET_DNS_SERVICE_TYPE_UDP;
 910
 911   if (NULL != tcp_redirects)
 912     service_type |= GNUNET_DNS_SERVICE_TYPE_TCP;
 913
 914   service_type = htonl (service_type);
 915
 916
 917   publish_name (section, ports, service_type, my_private_key);
 918
 919   GNUNET_CONFIGURATION_get_value_string (servicecfg, section,
 920                                          "ALTERNATIVE_NAMES",
 921                                          &alternative_names);
 922   for (alternative_name = strtok (alternative_names, " ");
 923        alternative_name != NULL; alternative_name = strtok (NULL, " "))
 924     {
 925       char *altname =
 926         alloca (strlen (alternative_name) + strlen (section) + 1 + 1);
 927       strcpy (altname, alternative_name);
 928       strcpy (altname + strlen (alternative_name) + 1, section);
 929       altname[strlen (alternative_name)] = '.';
 930
 931       publish_name (altname, ports, service_type, my_private_key);
 932     }
 933
 934   GNUNET_free_non_null(alternative_names);
 935   GNUNET_CRYPTO_rsa_key_free (my_private_key);
 936   GNUNET_free_non_null (udp_redirects);
 937   GNUNET_free_non_null (tcp_redirects);
 938 }
 939
 940 /**
 941  * Publish a DNS-record in the DHT. This is up to now just for testing.
 942  */
 943 static void
 944 publish_names (void *cls,
 945                const struct GNUNET_SCHEDULER_TaskContext *tc) {
 946     char *services;
 947     if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
 948       return;
 949
 950     if (NULL != servicecfg)
 951       GNUNET_CONFIGURATION_destroy(servicecfg);
 952
 953     GNUNET_CONFIGURATION_get_value_filename(cfg, "dns", "SERVICES", &services);
 954
 955     servicecfg = GNUNET_CONFIGURATION_create();
 956     if (GNUNET_OK == GNUNET_CONFIGURATION_parse(servicecfg, services))
 957       {
 958         GNUNET_log(GNUNET_ERROR_TYPE_INFO, "Parsing services %s\n", services);
 959         GNUNET_CONFIGURATION_iterate_sections(servicecfg, publish_iterate, NULL);
 960       }
 961     if (NULL != services)
 962       GNUNET_free(services);
 963
 964     GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_HOURS,
 965                                   publish_names,
 966                                   NULL);
 967 }
 968
 969 /**
 970  * @param cls closure
 971  * @param server the initialized server
 972  * @param cfg_ configuration to use
 973  */
 974 static void
 975 run (void *cls,
 976      struct GNUNET_SERVER_Handle *server,
 977      const struct GNUNET_CONFIGURATION_Handle *cfg_)
 978 {
 979   static const struct GNUNET_SERVER_MessageHandler handlers[] = {
 980     /* callback, cls, type, size */
 981     {&receive_query, NULL, GNUNET_MESSAGE_TYPE_LOCAL_QUERY_DNS, 0},
 982     {&rehijack, NULL, GNUNET_MESSAGE_TYPE_REHIJACK,
 983      sizeof (struct GNUNET_MessageHeader)},
 984     {NULL, NULL, 0, 0}
 985   };
 986
 987
 988   const static struct GNUNET_MESH_MessageHandler mesh_handlers[] = {
 989     //{receive_mesh_qery, GNUNET_MESSAGE_TYPE_REMOTE_QUERY_DNS, 0},
 990     {NULL, 0, 0}
 991   };
 992
 993   const static GNUNET_MESH_ApplicationType apptypes[] =
 994     { GNUNET_APPLICATION_TYPE_INTERNET_RESOLVER,
 995     GNUNET_APPLICATION_TYPE_END
 996   };
 997
 998   mesh_handle = GNUNET_MESH_connect (cfg_, NULL, NULL, mesh_handlers, apptypes);
 999
1000   cfg = cfg_;
1001
1002   unsigned int i;
1003   for (i = 0; i < 65536; i++)
1004     {
1005       query_states[i].valid = GNUNET_NO;
1006     }
1007
1008   dht = GNUNET_DHT_connect (cfg, 1024);
1009
1010   open_port ();
1011
1012   GNUNET_SCHEDULER_add_now (publish_names, NULL);
1013
1014   GNUNET_SERVER_add_handlers (server, handlers);
1015   GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
1016                                 &cleanup_task, cls);
1017 }
1018
1019 /**
1020  * The main function for the dns service.
1021  *
1022  * @param argc number of arguments from the command line
1023  * @param argv command line arguments
1024  * @return 0 ok, 1 on error
1025  */
1026 int
1027 main (int argc, char *const *argv)
1028 {
1029   return (GNUNET_OK ==
1030           GNUNET_SERVICE_run (argc,
1031                               argv,
1032                               "dns",
1033                               GNUNET_SERVICE_OPTION_NONE,
1034                               &run, NULL)) ? 0 : 1;
1035 }