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     struct dns_pkt_parsed* pdns = (struct dns_pkt_parsed*) cls;
 261
 262     unsigned short id = pdns->s.id;
 263
 264     free_parsed_dns_packet(pdns);
 265
 266     if (query_states[id].valid != GNUNET_YES) return;
 267     query_states[id].valid = GNUNET_NO;
 268
 269     GNUNET_assert(query_states[id].namelen == 74);
 270
 271     size_t len = sizeof(struct answer_packet) - 1 \
 272                  + sizeof(struct dns_static) \
 273                  + 74 /* this is the length of a reverse ipv6-lookup */ \
 274                  + sizeof(struct dns_query_line) \
 275                  + 2 /* To hold the pointer (as defined in RFC1035) to the name */ \
 276                  + sizeof(struct dns_record_line) - 1 \
 277                  - 2 /* We do not know the lenght of the answer yet*/;
 278
 279     struct answer_packet_list* answer = GNUNET_malloc(len + 2*sizeof(struct answer_packet_list*));
 280     memset(answer, 0, len + 2*sizeof(struct answer_packet_list*));
 281
 282     answer->pkt.hdr.type = htons(GNUNET_MESSAGE_TYPE_LOCAL_RESPONSE_DNS);
 283     answer->pkt.hdr.size = htons(len);
 284     answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_REV;
 285
 286     answer->pkt.from = query_states[id].remote_ip;
 287
 288     answer->pkt.to = query_states[id].local_ip;
 289     answer->pkt.dst_port = query_states[id].local_port;
 290
 291     struct dns_pkt *dpkt = (struct dns_pkt*)answer->pkt.data;
 292
 293     dpkt->s.id = id;
 294     dpkt->s.aa = 1;
 295     dpkt->s.qr = 1;
 296     dpkt->s.ra = 1;
 297     dpkt->s.qdcount = htons(1);
 298     dpkt->s.ancount = htons(1);
 299
 300     memcpy(dpkt->data, query_states[id].name, query_states[id].namelen);
 301     GNUNET_free(query_states[id].name);
 302
 303     struct dns_query_line* dque = (struct dns_query_line*)(dpkt->data+(query_states[id].namelen));
 304     dque->type = htons(12); /* PTR */
 305     dque->class = htons(1); /* IN */
 306
 307     char* anname = (char*)(dpkt->data+(query_states[id].namelen)+sizeof(struct dns_query_line));
 308     memcpy(anname, "\xc0\x0c", 2);
 309
 310     struct dns_record_line *drec_data = (struct dns_record_line*)(dpkt->data+(query_states[id].namelen)+sizeof(struct dns_query_line)+2);
 311     drec_data->type = htons(12); /* AAAA */
 312     drec_data->class = htons(1); /* IN */
 313     /* FIXME: read the TTL from block:
 314      * GNUNET_TIME_absolute_get_remaining(rec->expiration_time)
 315      *
 316      * But how to get the seconds out of this?
 317      */
 318     drec_data->ttl = htonl(3600);
 319
 320     /* Calculate at which offset in the packet the length of the name and the
 321      * name, it is filled in by the daemon-vpn */
 322     answer->pkt.addroffset = htons((unsigned short)((unsigned long)(&drec_data->data_len)-(unsigned long)(&answer->pkt)));
 323
 324     GNUNET_CONTAINER_DLL_insert_after(head, tail, tail, answer);
 325
 326     GNUNET_SERVER_notify_transmit_ready(query_states[id].client,
 327                                         len,
 328                                         GNUNET_TIME_UNIT_FOREVER_REL,
 329                                         &send_answer,
 330                                         query_states[id].client);
 331 }
 332
 333 /**
 334  * Receive a block from the dht.
 335  */
 336 static void
 337 receive_dht(void *cls,
 338             struct GNUNET_TIME_Absolute exp,
 339             const GNUNET_HashCode *key,
 340             const struct GNUNET_PeerIdentity *const *get_path,
 341             const struct GNUNET_PeerIdentity *const *put_path,
 342             enum GNUNET_BLOCK_Type type,
 343             size_t size,
 344             const void *data) {
 345
 346     unsigned short id = ((struct receive_dht_cls*)cls)->id;
 347     struct GNUNET_DHT_GetHandle* handle = ((struct receive_dht_cls*)cls)->handle;
 348     GNUNET_free(cls);
 349
 350     GNUNET_assert(type == GNUNET_BLOCK_TYPE_DNS);
 351
 352     /* If no query with this id is pending, ignore the block */
 353     if (query_states[id].valid != GNUNET_YES) return;
 354     query_states[id].valid = GNUNET_NO;
 355
 356     const struct GNUNET_DNS_Record* rec = data;
 357     GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
 358                "Got block of size %d, peer: %08x, desc: %08x\n",
 359                size,
 360                *((unsigned int*)&rec->peer),
 361                *((unsigned int*)&rec->service_descriptor));
 362
 363     size_t len = sizeof(struct answer_packet) - 1 \
 364                  + sizeof(struct dns_static) \
 365                  + query_states[id].namelen \
 366                  + sizeof(struct dns_query_line) \
 367                  + 2 /* To hold the pointer (as defined in RFC1035) to the name */ \
 368                  + sizeof(struct dns_record_line) - 1 \
 369                  + 16; /* To hold the IPv6-Address */
 370
 371     struct answer_packet_list* answer = GNUNET_malloc(len + 2*sizeof(struct answer_packet_list*));
 372     memset(answer, 0, len + 2*sizeof(struct answer_packet_list*));
 373
 374     answer->pkt.hdr.type = htons(GNUNET_MESSAGE_TYPE_LOCAL_RESPONSE_DNS);
 375     answer->pkt.hdr.size = htons(len);
 376     answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_SERVICE;
 377
 378     GNUNET_CRYPTO_hash(&rec->peer,
 379                        sizeof(struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
 380                        &answer->pkt.service_descr.peer);
 381
 382     memcpy(&answer->pkt.service_descr.service_descriptor,
 383            &rec->service_descriptor,
 384            sizeof(GNUNET_HashCode));
 385     memcpy(&answer->pkt.service_descr.service_type,
 386            &rec->service_type,
 387            sizeof(answer->pkt.service_descr.service_type));
 388     memcpy(&answer->pkt.service_descr.ports, &rec->ports, sizeof(answer->pkt.service_descr.ports));
 389
 390     answer->pkt.from = query_states[id].remote_ip;
 391
 392     answer->pkt.to = query_states[id].local_ip;
 393     answer->pkt.dst_port = query_states[id].local_port;
 394
 395     struct dns_pkt *dpkt = (struct dns_pkt*)answer->pkt.data;
 396
 397     dpkt->s.id = id;
 398     dpkt->s.aa = 1;
 399     dpkt->s.qr = 1;
 400     dpkt->s.ra = 1;
 401     dpkt->s.qdcount = htons(1);
 402     dpkt->s.ancount = htons(1);
 403
 404     memcpy(dpkt->data, query_states[id].name, query_states[id].namelen);
 405     GNUNET_free(query_states[id].name);
 406
 407     struct dns_query_line* dque = (struct dns_query_line*)(dpkt->data+(query_states[id].namelen));
 408     dque->type = htons(28); /* AAAA */
 409     dque->class = htons(1); /* IN */
 410
 411     char* anname = (char*)(dpkt->data+(query_states[id].namelen)+sizeof(struct dns_query_line));
 412     memcpy(anname, "\xc0\x0c", 2);
 413
 414     struct dns_record_line *drec_data = (struct dns_record_line*)(dpkt->data+(query_states[id].namelen)+sizeof(struct dns_query_line)+2);
 415     drec_data->type = htons(28); /* AAAA */
 416     drec_data->class = htons(1); /* IN */
 417
 418     /* FIXME: read the TTL from block:
 419      * GNUNET_TIME_absolute_get_remaining(rec->expiration_time)
 420      *
 421      * But how to get the seconds out of this?
 422      */
 423     drec_data->ttl = htonl(3600);
 424     drec_data->data_len = htons(16);
 425
 426     /* Calculate at which offset in the packet the IPv6-Address belongs, it is
 427      * filled in by the daemon-vpn */
 428     answer->pkt.addroffset = htons((unsigned short)((unsigned long)(&drec_data->data)-(unsigned long)(&answer->pkt)));
 429
 430     GNUNET_CONTAINER_DLL_insert_after(head, tail, tail, answer);
 431
 432     GNUNET_SERVER_notify_transmit_ready(query_states[id].client,
 433                                         len,
 434                                         GNUNET_TIME_UNIT_FOREVER_REL,
 435                                         &send_answer,
 436                                         query_states[id].client);
 437
 438     GNUNET_DHT_get_stop(handle);
 439 }
 440
 441 /**
 442  * This receives a GNUNET_MESSAGE_TYPE_REHIJACK and rehijacks the DNS
 443  */
 444 static void
 445 rehijack(void *cls,
 446          struct GNUNET_SERVER_Client *client,
 447          const struct GNUNET_MessageHeader *message) {
 448     unhijack(dnsoutport);
 449     GNUNET_SCHEDULER_add_delayed(GNUNET_TIME_UNIT_SECONDS, hijack, NULL);
 450
 451     GNUNET_SERVER_receive_done(client, GNUNET_OK);
 452 }
 453
 454 /**
 455  * This receives the dns-payload from the daemon-vpn and sends it on over the udp-socket
 456  */
 457 static void
 458 receive_query(void *cls,
 459               struct GNUNET_SERVER_Client *client,
 460               const struct GNUNET_MessageHeader *message) {
 461     struct query_packet* pkt = (struct query_packet*)message;
 462     struct dns_pkt* dns = (struct dns_pkt*)pkt->data;
 463     struct dns_pkt_parsed* pdns = parse_dns_packet(dns);
 464
 465     query_states[dns->s.id].valid = GNUNET_YES;
 466     query_states[dns->s.id].client = client;
 467     query_states[dns->s.id].local_ip = pkt->orig_from;
 468     query_states[dns->s.id].local_port = pkt->src_port;
 469     query_states[dns->s.id].remote_ip = pkt->orig_to;
 470     query_states[dns->s.id].namelen = strlen((char*)dns->data) + 1;
 471     query_states[dns->s.id].name = GNUNET_malloc(query_states[dns->s.id].namelen);
 472     memcpy(query_states[dns->s.id].name, dns->data, query_states[dns->s.id].namelen);
 473
 474     /* The query is for a .gnunet-address */
 475     if (pdns->queries[0]->namelen > 9 &&
 476         0 == strncmp(pdns->queries[0]->name+(pdns->queries[0]->namelen - 9), ".gnunet.", 9))
 477       {
 478         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Query for .gnunet!\n");
 479         GNUNET_HashCode key;
 480         GNUNET_CRYPTO_hash(pdns->queries[0]->name, pdns->queries[0]->namelen, &key);
 481
 482         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
 483                    "Getting with key %08x, len is %d\n",
 484                    *((unsigned int*)&key),
 485                    pdns->queries[0]->namelen);
 486
 487         struct receive_dht_cls* cls = GNUNET_malloc(sizeof(struct receive_dht_cls));
 488         cls->id = dns->s.id;
 489
 490         cls->handle = GNUNET_DHT_get_start(dht,
 491                                            GNUNET_TIME_UNIT_MINUTES,
 492                                            GNUNET_BLOCK_TYPE_DNS,
 493                                            &key,
 494                                            DEFAULT_GET_REPLICATION,
 495                                            GNUNET_DHT_RO_NONE,
 496                                            NULL,
 497                                            0,
 498                                            NULL,
 499                                            0,
 500                                            receive_dht,
 501                                            cls);
 502
 503         goto outfree;
 504       }
 505
 506     GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Query for '%s'; namelen=%d\n", pdns->queries[0]->name, pdns->queries[0]->namelen);
 507     /* The query is for a PTR of a previosly resolved virtual IP */
 508     if (htons(pdns->queries[0]->qtype) == 12 &&
 509         74 == pdns->queries[0]->namelen)
 510       {
 511         char* ipv6addr;
 512         char ipv6[16];
 513         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.";
 514         unsigned int i;
 515         unsigned long long ipv6prefix;
 516         unsigned int comparelen;
 517
 518         GNUNET_assert(GNUNET_OK == GNUNET_CONFIGURATION_get_value_string(cfg, "vpn", "IPV6ADDR", &ipv6addr));
 519         inet_pton (AF_INET6, ipv6addr, ipv6);
 520         GNUNET_free(ipv6addr);
 521
 522         GNUNET_assert(GNUNET_OK == GNUNET_CONFIGURATION_get_value_number(cfg, "vpn", "IPV6PREFIX", &ipv6prefix));
 523         GNUNET_assert(ipv6prefix < 127);
 524         ipv6prefix = (ipv6prefix + 7)/8;
 525
 526         for (i = ipv6prefix; i < 16; i++)
 527           ipv6[i] = 0;
 528
 529         for (i = 0; i < 16; i++)
 530           {
 531             unsigned char c1 = ipv6[i] >> 4;
 532             unsigned char c2 = ipv6[i] & 0xf;
 533
 534             if (c1 <= 9)
 535               ipv6rev[62-(4*i)] = c1 + '0';
 536             else
 537               ipv6rev[62-(4*i)] = c1 + 87; /* 87 is the difference between 'a' and 10 */
 538
 539             if (c2 <= 9)
 540               ipv6rev[62-((4*i)+2)] = c2 + '0';
 541             else
 542               ipv6rev[62-((4*i)+2)] = c2 + 87;
 543           }
 544         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "My network is %s'.\n", ipv6rev);
 545         comparelen = 10 + 4*ipv6prefix;
 546         if(0 == strncmp(pdns->queries[0]->name+(pdns->queries[0]->namelen - comparelen),
 547                         ipv6rev + (74 - comparelen),
 548                         comparelen))
 549           {
 550             GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Reverse-Query for .gnunet!\n");
 551
 552             GNUNET_SCHEDULER_add_now(send_rev_query, pdns);
 553
 554             goto out;
 555           }
 556       }
 557
 558     char* virt_dns;
 559     int virt_dns_bytes;
 560     if (GNUNET_SYSERR ==
 561         GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "VIRTDNS",
 562                                                &virt_dns))
 563       {
 564         GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 565                     "No entry 'VIRTDNS' in configuration!\n");
 566         exit (1);
 567       }
 568
 569     if (1 != inet_pton (AF_INET, virt_dns, &virt_dns_bytes))
 570       {
 571         GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 572                     "Error parsing 'VIRTDNS': %s; %m!\n", virt_dns);
 573         exit(1);
 574       }
 575
 576     GNUNET_free(virt_dns);
 577
 578     if (virt_dns_bytes == pkt->orig_to)
 579       {
 580         /* This is a packet that was sent directly to the virtual dns-server
 581          *
 582          * This means we have to send this query over gnunet
 583          */
 584
 585         size_t size = sizeof(struct GNUNET_MESH_Tunnel*) + sizeof(struct GNUNET_MessageHeader) + (ntohs(message->size) - sizeof(struct query_packet) + 1);
 586         struct tunnel_cls *cls_ =  GNUNET_malloc(size);
 587         cls_->hdr.size = size - sizeof(struct GNUNET_MESH_Tunnel*);
 588
 589         cls_->hdr.type = ntohs(GNUNET_MESSAGE_TYPE_REMOTE_QUERY_DNS);
 590
 591         memcpy(&cls_->dns, dns, cls_->hdr.size);
 592         GNUNET_SCHEDULER_add_now(send_mesh_query, cls_);
 593
 594         goto out;
 595       }
 596
 597
 598     /* The query should be sent to the network */
 599
 600     struct sockaddr_in dest;
 601     memset(&dest, 0, sizeof dest);
 602     dest.sin_port = htons(53);
 603     dest.sin_addr.s_addr = pkt->orig_to;
 604
 605     GNUNET_NETWORK_socket_sendto(dnsout,
 606                                  dns,
 607                                  ntohs(pkt->hdr.size) - sizeof(struct query_packet) + 1,
 608                                  (struct sockaddr*) &dest,
 609                                  sizeof dest);
 610
 611 outfree:
 612     free_parsed_dns_packet(pdns);
 613     pdns = NULL;
 614 out:
 615     GNUNET_SERVER_receive_done(client, GNUNET_OK);
 616 }
 617
 618 static void read_response (void *cls,
 619                            const struct GNUNET_SCHEDULER_TaskContext *tc);
 620
 621 static void
 622 open_port ()
 623 {
 624   struct sockaddr_in addr;
 625
 626   dnsout = GNUNET_NETWORK_socket_create (AF_INET, SOCK_DGRAM, 0);
 627   if (dnsout == NULL)
 628     return;
 629   memset (&addr, 0, sizeof (struct sockaddr_in));
 630
 631   int err = GNUNET_NETWORK_socket_bind (dnsout,
 632                                         (struct sockaddr *) &addr,
 633                                         sizeof (struct sockaddr_in));
 634
 635   if (err != GNUNET_YES)
 636     {
 637       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 638                   "Could not bind a port, exiting\n");
 639       return;
 640     }
 641
 642   /* Read the port we bound to */
 643   socklen_t addrlen = sizeof (struct sockaddr_in);
 644   err = getsockname (GNUNET_NETWORK_get_fd (dnsout),
 645                      (struct sockaddr *) &addr, &addrlen);
 646
 647   dnsoutport = htons (addr.sin_port);
 648
 649   GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL, dnsout,
 650                                  &read_response, NULL);
 651 }
 652
 653 /**
 654  * Read a response-packet of the UDP-Socket
 655  */
 656 static void
 657 read_response (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) {
 658     struct sockaddr_in addr;
 659     socklen_t addrlen = sizeof (addr);
 660     int r;
 661     int len;
 662
 663     if (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)
 664       return;
 665
 666     memset(&addr, 0, sizeof addr);
 667
 668 #ifndef MINGW
 669     if (0 != ioctl (GNUNET_NETWORK_get_fd (dnsout),
 670                     FIONREAD, &len))
 671       {
 672         unhijack(dnsoutport);
 673         open_port();
 674         GNUNET_SCHEDULER_add_delayed(GNUNET_TIME_UNIT_SECONDS, hijack, NULL);
 675         return;
 676       }
 677 #else
 678     /* port the code above? */
 679     len = 65536;
 680 #endif
 681     {
 682       unsigned char buf[len];
 683       struct dns_pkt* dns = (struct dns_pkt*)buf;
 684
 685       r = GNUNET_NETWORK_socket_recvfrom (dnsout,
 686                                           buf,
 687                                           sizeof (buf),
 688                                           (struct sockaddr*)&addr,
 689                                           &addrlen);
 690
 691       if (r < 0)
 692         {
 693           unhijack(dnsoutport);
 694           open_port();
 695           GNUNET_SCHEDULER_add_delayed(GNUNET_TIME_UNIT_SECONDS, hijack, NULL);
 696           return;
 697         }
 698
 699       if (query_states[dns->s.id].valid == GNUNET_YES)
 700         {
 701           query_states[dns->s.id].valid = GNUNET_NO;
 702
 703           size_t len = sizeof(struct answer_packet) + r - 1; /* 1 for the unsigned char data[1]; */
 704           struct answer_packet_list* answer = GNUNET_malloc(len + 2*sizeof(struct answer_packet_list*));
 705           answer->pkt.hdr.type = htons(GNUNET_MESSAGE_TYPE_LOCAL_RESPONSE_DNS);
 706           answer->pkt.hdr.size = htons(len);
 707           answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_IP;
 708           answer->pkt.from = addr.sin_addr.s_addr;
 709           answer->pkt.to = query_states[dns->s.id].local_ip;
 710           answer->pkt.dst_port = query_states[dns->s.id].local_port;
 711           memcpy(answer->pkt.data, buf, r);
 712
 713           GNUNET_CONTAINER_DLL_insert_after(head, tail, tail, answer);
 714
 715           GNUNET_SERVER_notify_transmit_ready(query_states[dns->s.id].client,
 716                                               len,
 717                                               GNUNET_TIME_UNIT_FOREVER_REL,
 718                                               &send_answer,
 719                                               query_states[dns->s.id].client);
 720         }
 721     }
 722     GNUNET_SCHEDULER_add_read_net(GNUNET_TIME_UNIT_FOREVER_REL,
 723                                   dnsout,
 724                                   &read_response,
 725                                   NULL);
 726 }
 727
 728
 729 /**
 730  * Task run during shutdown.
 731  *
 732  * @param cls unused
 733  * @param tc unused
 734  */
 735 static void
 736 cleanup_task (void *cls,
 737               const struct GNUNET_SCHEDULER_TaskContext *tc)
 738 {
 739   unhijack(dnsoutport);
 740   GNUNET_DHT_disconnect(dht);
 741 }
 742
 743 /**
 744  * @brief Create a port-map from udp and tcp redirects
 745  *
 746  * @param udp_redirects
 747  * @param tcp_redirects
 748  *
 749  * @return
 750  */
 751 uint64_t
 752 get_port_from_redirects (const char *udp_redirects, const char *tcp_redirects)
 753 {
 754   uint64_t ret = 0;
 755   char* cpy, *hostname, *redirect;
 756   int local_port, count = 0;
 757
 758   if (NULL != udp_redirects)
 759     {
 760       cpy = GNUNET_strdup (udp_redirects);
 761       for (redirect = strtok (cpy, " "); redirect != NULL; redirect = strtok (NULL, " "))
 762         {
 763           if (NULL == (hostname = strstr (redirect, ":")))
 764             {
 765               GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Warning: option %s is not formatted correctly!\n", redirect);
 766               continue;
 767             }
 768           hostname[0] = '\0';
 769           local_port = atoi (redirect);
 770           if (!((local_port > 0) && (local_port < 65536)))
 771             GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Warning: %s is not a correct port.", redirect);
 772
 773           ret |= (0xFFFF & htons(local_port));
 774           ret <<= 16;
 775           count ++;
 776
 777           if(count > 4)
 778             {
 779               ret = 0;
 780               goto out;
 781             }
 782         }
 783       GNUNET_free(cpy);
 784       cpy = NULL;
 785     }
 786
 787   if (NULL != tcp_redirects)
 788     {
 789       cpy = GNUNET_strdup (tcp_redirects);
 790       for (redirect = strtok (cpy, " "); redirect != NULL; redirect = strtok (NULL, " "))
 791         {
 792           if (NULL == (hostname = strstr (redirect, ":")))
 793             {
 794               GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Warning: option %s is not formatted correctly!\n", redirect);
 795               continue;
 796             }
 797           hostname[0] = '\0';
 798           local_port = atoi (redirect);
 799           if (!((local_port > 0) && (local_port < 65536)))
 800             GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Warning: %s is not a correct port.", redirect);
 801
 802           ret |= (0xFFFF & htons(local_port));
 803           ret <<= 16;
 804           count ++;
 805
 806           if(count > 4)
 807             {
 808               ret = 0;
 809               goto out;
 810             }
 811         }
 812       GNUNET_free(cpy);
 813       cpy = NULL;
 814     }
 815
 816 out:
 817   if (NULL != cpy)
 818     GNUNET_free(cpy);
 819   return ret;
 820 }
 821
 822 void
 823 publish_name (const char *name, uint64_t ports, uint32_t service_type,
 824               struct GNUNET_CRYPTO_RsaPrivateKey *my_private_key)
 825 {
 826   size_t size = sizeof (struct GNUNET_DNS_Record);
 827   struct GNUNET_DNS_Record data;
 828   memset (&data, 0, size);
 829
 830   data.purpose.size =
 831     htonl (size - sizeof (struct GNUNET_CRYPTO_RsaSignature));
 832   data.purpose.purpose = GNUNET_SIGNATURE_PURPOSE_DNS_RECORD;
 833
 834   GNUNET_CRYPTO_hash (name, strlen (name) + 1, &data.service_descriptor);
 835   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Store with key1 %x\n",
 836               *((unsigned long long *) &data.service_descriptor));
 837
 838   data.service_type = service_type;
 839   data.ports = ports;
 840
 841   GNUNET_CRYPTO_rsa_key_get_public (my_private_key, &data.peer);
 842
 843   data.expiration_time =
 844     GNUNET_TIME_relative_to_absolute (GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_HOURS, 2));
 845
 846   /* Sign the block */
 847   if (GNUNET_OK != GNUNET_CRYPTO_rsa_sign (my_private_key,
 848                                            &data.purpose, &data.signature))
 849     {
 850       GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "could not sign DNS_Record\n");
 851       return;
 852     }
 853
 854   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 855               "Putting with key %08x, size = %d\n",
 856               *((unsigned int *) &data.service_descriptor), size);
 857
 858   GNUNET_DHT_put (dht,
 859                   &data.service_descriptor,
 860                   DEFAULT_PUT_REPLICATION,
 861                   GNUNET_DHT_RO_NONE,
 862                   GNUNET_BLOCK_TYPE_DNS,
 863                   size,
 864                   (char *) &data,
 865                   GNUNET_TIME_relative_to_absolute (GNUNET_TIME_UNIT_HOURS),
 866                   GNUNET_TIME_UNIT_MINUTES, NULL, NULL);
 867 }
 868
 869 /**
 870  * @brief Publishes the record defined by the section section
 871  *
 872  * @param cls closure
 873  * @param section the current section
 874  */
 875 void
 876 publish_iterate (void *cls, const char *section)
 877 {
 878   char *udp_redirects, *tcp_redirects, *alternative_names, *alternative_name,
 879     *keyfile;
 880
 881   GNUNET_CONFIGURATION_get_value_string (servicecfg, section,
 882                                          "UDP_REDIRECTS", &udp_redirects);
 883   GNUNET_CONFIGURATION_get_value_string (servicecfg, section, "TCP_REDIRECTS",
 884                                          &tcp_redirects);
 885
 886   if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_filename (cfg, "GNUNETD",
 887                                                             "HOSTKEY",
 888                                                             &keyfile))
 889     {
 890       GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "could not read keyfile-value\n");
 891       if (keyfile != NULL)
 892         GNUNET_free (keyfile);
 893       return;
 894     }
 895
 896   struct GNUNET_CRYPTO_RsaPrivateKey *my_private_key =
 897     GNUNET_CRYPTO_rsa_key_create_from_file (keyfile);
 898   GNUNET_free (keyfile);
 899   GNUNET_assert (my_private_key != NULL);
 900
 901   uint64_t ports = get_port_from_redirects (udp_redirects, tcp_redirects);
 902   uint32_t service_type = 0;
 903
 904   if (NULL != udp_redirects)
 905     service_type = GNUNET_DNS_SERVICE_TYPE_UDP;
 906
 907   if (NULL != tcp_redirects)
 908     service_type |= GNUNET_DNS_SERVICE_TYPE_TCP;
 909
 910   service_type = htonl (service_type);
 911
 912
 913   publish_name (section, ports, service_type, my_private_key);
 914
 915   GNUNET_CONFIGURATION_get_value_string (servicecfg, section,
 916                                          "ALTERNATIVE_NAMES",
 917                                          &alternative_names);
 918   for (alternative_name = strtok (alternative_names, " ");
 919        alternative_name != NULL; alternative_name = strtok (NULL, " "))
 920     {
 921       char *altname =
 922         alloca (strlen (alternative_name) + strlen (section) + 1 + 1);
 923       strcpy (altname, alternative_name);
 924       strcpy (altname + strlen (alternative_name) + 1, section);
 925       altname[strlen (alternative_name)] = '.';
 926
 927       publish_name (altname, ports, service_type, my_private_key);
 928     }
 929
 930   GNUNET_free_non_null(alternative_names);
 931   GNUNET_CRYPTO_rsa_key_free (my_private_key);
 932   GNUNET_free_non_null (udp_redirects);
 933   GNUNET_free_non_null (tcp_redirects);
 934 }
 935
 936 /**
 937  * Publish a DNS-record in the DHT. This is up to now just for testing.
 938  */
 939 static void
 940 publish_names (void *cls,
 941                const struct GNUNET_SCHEDULER_TaskContext *tc) {
 942     char *services;
 943     if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
 944       return;
 945
 946     if (NULL != servicecfg)
 947       GNUNET_CONFIGURATION_destroy(servicecfg);
 948
 949     GNUNET_CONFIGURATION_get_value_filename(cfg, "dns", "SERVICES", &services);
 950
 951     servicecfg = GNUNET_CONFIGURATION_create();
 952     if (GNUNET_OK == GNUNET_CONFIGURATION_parse(servicecfg, services))
 953       {
 954         GNUNET_log(GNUNET_ERROR_TYPE_INFO, "Parsing services %s\n", services);
 955         GNUNET_CONFIGURATION_iterate_sections(servicecfg, publish_iterate, NULL);
 956       }
 957     if (NULL != services)
 958       GNUNET_free(services);
 959
 960     GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_HOURS,
 961                                   publish_names,
 962                                   NULL);
 963 }
 964
 965 /**
 966  * @param cls closure
 967  * @param server the initialized server
 968  * @param cfg_ configuration to use
 969  */
 970 static void
 971 run (void *cls,
 972      struct GNUNET_SERVER_Handle *server,
 973      const struct GNUNET_CONFIGURATION_Handle *cfg_)
 974 {
 975   static const struct GNUNET_SERVER_MessageHandler handlers[] = {
 976       /* callback, cls, type, size */
 977         {&receive_query, NULL, GNUNET_MESSAGE_TYPE_LOCAL_QUERY_DNS, 0},
 978         {&rehijack, NULL, GNUNET_MESSAGE_TYPE_REHIJACK, sizeof(struct GNUNET_MessageHeader)},
 979         {NULL, NULL, 0, 0}
 980   };
 981
 982
 983   const static struct GNUNET_MESH_MessageHandler mesh_handlers[] = {
 984     //{receive_mesh_qery, GNUNET_MESSAGE_TYPE_REMOTE_QUERY_DNS, 0},
 985     {NULL, 0, 0}
 986   };
 987
 988   const static GNUNET_MESH_ApplicationType apptypes[] =
 989     { GNUNET_APPLICATION_TYPE_INTERNET_RESOLVER,
 990     GNUNET_APPLICATION_TYPE_END
 991   };
 992
 993   mesh_handle = GNUNET_MESH_connect (cfg_, NULL, NULL, mesh_handlers, apptypes);
 994
 995   cfg = cfg_;
 996
 997   unsigned int i;
 998   for (i = 0; i < 65536; i++) {
 999       query_states[i].valid = GNUNET_NO;
1000   }
1001
1002   dht = GNUNET_DHT_connect(cfg, 1024);
1003
1004   open_port();
1005
1006   GNUNET_SCHEDULER_add_now (publish_names, NULL);
1007
1008   GNUNET_SERVER_add_handlers (server, handlers);
1009   GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
1010                                 &cleanup_task,
1011                                 cls);
1012 }
1013
1014 /**
1015  * The main function for the dns service.
1016  *
1017  * @param argc number of arguments from the command line
1018  * @param argv command line arguments
1019  * @return 0 ok, 1 on error
1020  */
1021 int
1022 main (int argc, char *const *argv)
1023 {
1024   return (GNUNET_OK ==
1025           GNUNET_SERVICE_run (argc,
1026                               argv,
1027                               "dns",
1028                               GNUNET_SERVICE_OPTION_NONE,
1029                               &run, NULL)) ? 0 : 1;
1030 }