src/dns.cpp

   1 /*
   2 dns.cpp - based on the firedns library Copyright (C) 2002 Ian Gulliver
   3
   4 This program is free software; you can redistribute it and/or modify
   5 it under the terms of version 2 of the GNU General Public License as
   6 published by the Free Software Foundation.
   7
   8 This program is distributed in the hope that it will be useful,
   9 but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11 GNU General Public License for more details.
  12
  13 You should have received a copy of the GNU General Public License
  14 along with this program; if not, write to the Free Software
  15 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  16 */
  17
  18 #define _DNS_C
  19
  20 using namespace std;
  21
  22 #include <string>
  23 #include <stdlib.h>
  24 #include <time.h>
  25 #include <sys/types.h>
  26 #include <sys/socket.h>
  27 #include <sys/time.h>
  28 #include <string.h>
  29 #include <unistd.h>
  30 #include <stdio.h>
  31 #include <errno.h>
  32 #include <fcntl.h>
  33 #include <poll.h>
  34 #include <sys/types.h>
  35 #include <sys/socket.h>
  36 #include <netinet/in.h>
  37 #include <arpa/inet.h>
  38 #include "dns.h"
  39 #include "helperfuncs.h"
  40
  41 extern int statsAccept,statsRefused,statsUnknown,statsCollisions,statsDns,statsDnsGood,statsDnsBad,statsConnects,statsSent,statsRecv;
  42
  43 #define max(a,b) (a > b ? a : b)
  44 #define DNS_MAX              8                    /* max number of nameservers used */
  45 #define DNS_CONFIG_FBCK     "/etc/resolv.conf"    /* fallback config file */
  46 #define DNS_PORT            53                    /* DNS well known port */
  47 #define DNS_QRY_A            1                    /* name to IP address */
  48 #define DNS_QRY_AAAA        28                    /* name to IP6 address */
  49 #define DNS_QRY_PTR         12                    /* IP address to name */
  50 #define DNS_QRY_MX          15                    /* name to MX */
  51 #define DNS_QRY_TXT         16                    /* name to TXT */
  52 #define DNS_QRY_CNAME       5
  53
  54 #define DNS_ALIGN (sizeof(void *) > sizeof(long) ? sizeof(void *) : sizeof(long))
  55 #define DNS_TRIES 3
  56 #define RESULTSIZE 1024
  57 #define min(a,b) (a < b ? a : b)
  58
  59 static struct in_addr servers4[DNS_MAX]; /* up to DNS_MAX nameservers; populated by dns_init() */
  60 static int i4; /* actual count of nameservers; set by dns_init() */
  61
  62 static int initdone = 0; /* to ensure dns_init() only runs once (on the first call) */
  63 static int wantclose = 0;
  64 static int lastcreate = -1;
  65
  66 struct s_connection { /* open DNS query */
  67         struct s_connection *next; /* next in list */
  68         unsigned char id[2];
  69         unsigned int _class;
  70         unsigned int type;
  71         int want_list;
  72         int fd; /* file descriptor returned from sockets */
  73 };
  74
  75 struct s_rr_middle {
  76         unsigned int type;
  77         unsigned int _class;
  78         unsigned long ttl;
  79         unsigned int rdlength;
  80 };
  81
  82 #define DNS_POINTER_VALUE 0xc000
  83
  84 static s_connection *connection_head = NULL; /* linked list of open DNS queries; populated by dns_add_query(), decimated by dns_getresult_s() */
  85
  86 struct s_header { /* DNS query header */
  87         unsigned char id[2];
  88         unsigned int flags1;
  89 #define FLAGS1_MASK_QR 0x80
  90 #define FLAGS1_MASK_OPCODE 0x78 /* bitshift right 3 */
  91 #define FLAGS1_MASK_AA 0x04
  92 #define FLAGS1_MASK_TC 0x02
  93 #define FLAGS1_MASK_RD 0x01
  94         unsigned int flags2;
  95 #define FLAGS2_MASK_RA 0x80
  96 #define FLAGS2_MASK_Z  0x70
  97 #define FLAGS2_MASK_RCODE 0x0f
  98         unsigned int qdcount;
  99         unsigned int ancount;
 100         unsigned int nscount;
 101         unsigned int arcount;
 102         unsigned char payload[512]; /* DNS question, populated by dns_build_query_payload() */
 103 };
 104
 105 extern time_t TIME;
 106
 107 void *dns_align(void *inp) {
 108         char *p = (char*)inp;
 109         int offby = ((char *)p - (char *)0) % DNS_ALIGN;
 110         if (offby != 0)
 111                 return p + (DNS_ALIGN - offby);
 112         else
 113                 return p;
 114 }
 115
 116 /*
 117  * These little hacks are here to avoid alignment and type sizing issues completely by doing manual copies
 118  */
 119 void dns_fill_rr(s_rr_middle* rr, const unsigned char *input) {
 120         rr->type = input[0] * 256 + input[1];
 121         rr->_class = input[2] * 256 + input[3];
 122         rr->ttl = input[4] * 16777216 + input[5] * 65536 + input[6] * 256 + input[7];
 123         rr->rdlength = input[8] * 256 + input[9];
 124 }
 125
 126 void dns_fill_header(s_header *header, const unsigned char *input, const int l) {
 127         header->id[0] = input[0];
 128         header->id[1] = input[1];
 129         header->flags1 = input[2];
 130         header->flags2 = input[3];
 131         header->qdcount = input[4] * 256 + input[5];
 132         header->ancount = input[6] * 256 + input[7];
 133         header->nscount = input[8] * 256 + input[9];
 134         header->arcount = input[10] * 256 + input[11];
 135         memcpy(header->payload,&input[12],l);
 136 }
 137
 138 void dns_empty_header(unsigned char *output, const s_header *header, const int l) {
 139         output[0] = header->id[0];
 140         output[1] = header->id[1];
 141         output[2] = header->flags1;
 142         output[3] = header->flags2;
 143         output[4] = header->qdcount / 256;
 144         output[5] = header->qdcount % 256;
 145         output[6] = header->ancount / 256;
 146         output[7] = header->ancount % 256;
 147         output[8] = header->nscount / 256;
 148         output[9] = header->nscount % 256;
 149         output[10] = header->arcount / 256;
 150         output[11] = header->arcount % 256;
 151         memcpy(&output[12],header->payload,l);
 152 }
 153
 154 void dns_close(int fd) { /* close query */
 155         log(DEBUG,"DNS: dns_close on fd %d",fd);
 156         if (fd == lastcreate) {
 157                 wantclose = 1;
 158                 return;
 159         }
 160         shutdown(fd,2);
 161         close(fd);
 162         return;
 163 }
 164
 165 void DNS::dns_init() { /* on first call only: populates servers4 struct with up to DNS_MAX nameserver IP addresses from /etc/resolv.conf */
 166         FILE *f;
 167         int i;
 168         in_addr addr4;
 169         char buf[1024];
 170         if (initdone == 1)
 171                 return;
 172         i4 = 0;
 173
 174         initdone = 1;
 175         srand((unsigned int) TIME);
 176         memset(servers4,'\0',sizeof(in_addr) * DNS_MAX);
 177         f = fopen(DNS_CONFIG_FBCK,"r");
 178         if (f == NULL)
 179                 return;
 180         while (fgets(buf,1024,f) != NULL) {
 181                 if (strncmp(buf,"nameserver",10) == 0) {
 182                         i = 10;
 183                         while (buf[i] == ' ' || buf[i] == '\t')
 184                                 i++;
 185                         if (i4 < DNS_MAX) {
 186                                 if (dns_aton4_s(&buf[i],&addr4) != NULL)
 187                                         memcpy(&servers4[i4++],&addr4,sizeof(in_addr));
 188                         }
 189                 }
 190         }
 191         fclose(f);
 192 }
 193
 194 void DNS::dns_init_2(const char* dnsserver)
 195 {
 196         in_addr addr4;
 197         i4 = 0;
 198         srand((unsigned int) TIME);
 199         memset(servers4,'\0',sizeof(in_addr) * DNS_MAX);
 200         if (dns_aton4_s(dnsserver,&addr4) != NULL)
 201             memcpy(&servers4[i4++],&addr4,sizeof(in_addr));
 202 }
 203
 204
 205 static int dns_send_requests(const s_header *h, const s_connection *s, const int l)
 206 {
 207         int i;
 208         sockaddr_in addr4;
 209         unsigned char payload[sizeof(s_header)];
 210
 211         dns_empty_header(payload,h,l);
 212
 213
 214         i = 0;
 215
 216         /* otherwise send via standard ipv4 boringness */
 217         memset(&addr4,0,sizeof(addr4));
 218         memcpy(&addr4.sin_addr,&servers4[i],sizeof(addr4.sin_addr));
 219         addr4.sin_family = AF_INET;
 220         addr4.sin_port = htons(DNS_PORT);
 221         if (sendto(s->fd, payload, l + 12, 0, (sockaddr *) &addr4, sizeof(addr4)) == -1)
 222         {
 223                 return -1;
 224         }
 225
 226         return 0;
 227 }
 228
 229 static s_connection *dns_add_query(s_header *h) { /* build DNS query, add to list */
 230         s_connection * s;
 231
 232         s = new s_connection;
 233
 234         /* set header flags */
 235         h->id[0] = s->id[0] = rand() % 255; /* verified by dns_getresult_s() */
 236         h->id[1] = s->id[1] = rand() % 255;
 237         h->flags1 = 0 | FLAGS1_MASK_RD;
 238         h->flags2 = 0;
 239         h->qdcount = 1;
 240         h->ancount = 0;
 241         h->nscount = 0;
 242         h->arcount = 0;
 243
 244         /* turn off want_list by default */
 245         s->want_list = 0;
 246
 247         /* try to create ipv6 or ipv4 socket */
 248                 s->fd = socket(PF_INET, SOCK_DGRAM, 0);
 249                 if (s->fd != -1) {
 250                         if (fcntl(s->fd, F_SETFL, O_NONBLOCK) != 0) {
 251                                 shutdown(s->fd,2);
 252                                 close(s->fd);
 253                                 s->fd = -1;
 254                         }
 255                 }
 256                 if (s->fd != -1) {
 257                         sockaddr_in addr;
 258                         memset(&addr,0,sizeof(addr));
 259                         addr.sin_family = AF_INET;
 260                         addr.sin_port = 0;
 261                         addr.sin_addr.s_addr = INADDR_ANY;
 262                         if (bind(s->fd,(sockaddr *)&addr,sizeof(addr)) != 0) {
 263                                 shutdown(s->fd,2);
 264                                 close(s->fd);
 265                                 s->fd = -1;
 266                         }
 267                 }
 268                 if (s->fd == -1) {
 269                         delete s;
 270                         return NULL;
 271                 }
 272         /* create new connection object, add to linked list */
 273         s->next = connection_head;
 274         connection_head = s;
 275
 276         if (wantclose == 1) {
 277                 shutdown(lastcreate,2);
 278                 close(lastcreate);
 279                 wantclose = 0;
 280         }
 281         lastcreate = s->fd;
 282         return s;
 283 }
 284
 285 static int dns_build_query_payload(const char * const name, const unsigned short rr, const unsigned short _class, unsigned char * const payload) {
 286         short payloadpos;
 287         const char * tempchr, * tempchr2;
 288         unsigned short l;
 289
 290         payloadpos = 0;
 291         tempchr2 = name;
 292
 293         /* split name up into labels, create query */
 294         while ((tempchr = strchr(tempchr2,'.')) != NULL) {
 295                 l = tempchr - tempchr2;
 296                 if (payloadpos + l + 1 > 507)
 297                         return -1;
 298                 payload[payloadpos++] = l;
 299                 memcpy(&payload[payloadpos],tempchr2,l);
 300                 payloadpos += l;
 301                 tempchr2 = &tempchr[1];
 302         }
 303         l = strlen(tempchr2);
 304         if (l) {
 305                 if (payloadpos + l + 2 > 507)
 306                         return -1;
 307                 payload[payloadpos++] = l;
 308                 memcpy(&payload[payloadpos],tempchr2,l);
 309                 payloadpos += l;
 310                 payload[payloadpos++] = '\0';
 311         }
 312         if (payloadpos > 508)
 313                 return -1;
 314         l = htons(rr);
 315         memcpy(&payload[payloadpos],&l,2);
 316         l = htons(_class);
 317         memcpy(&payload[payloadpos + 2],&l,2);
 318         return payloadpos + 4;
 319 }
 320
 321 in_addr* DNS::dns_aton4(const char * const ipstring) { /* ascii to numeric: convert string to static 4part IP addr struct */
 322         static in_addr ip;
 323         return dns_aton4_s(ipstring,&ip);
 324 }
 325
 326 in_addr* DNS::dns_aton4_r(const char *ipstring) { /* ascii to numeric (reentrant): convert string to new 4part IP addr struct */
 327         in_addr* ip;
 328         ip = new in_addr;
 329         if(dns_aton4_s(ipstring,ip) == NULL) {
 330                 delete ip;
 331                 return NULL;
 332         }
 333         return ip;
 334 }
 335
 336 in_addr* DNS::dns_aton4_s(const char *ipstring, in_addr *ip) { /* ascii to numeric (buffered): convert string to given 4part IP addr struct */
 337         inet_aton(ipstring,ip);
 338         return ip;
 339 }
 340
 341 int DNS::dns_getip4(const char *name) { /* build, add and send A query; retrieve result with dns_getresult() */
 342         s_header h;
 343         s_connection *s;
 344         int l;
 345
 346         dns_init();
 347
 348
 349         l = dns_build_query_payload(name,DNS_QRY_A,1,(unsigned char *)&h.payload);
 350         if (l == -1)
 351                 return -1;
 352         s = dns_add_query(&h);
 353         if (s == NULL)
 354                 return -1;
 355         s->_class = 1;
 356         s->type = DNS_QRY_A;
 357         if (dns_send_requests(&h,s,l) == -1)
 358                 return -1;
 359
 360         return s->fd;
 361 }
 362
 363 int DNS::dns_getip4list(const char *name) { /* build, add and send A query; retrieve result with dns_getresult() */
 364         s_header h;
 365         s_connection *s;
 366         int l;
 367
 368         dns_init();
 369
 370
 371         l = dns_build_query_payload(name,DNS_QRY_A,1,(unsigned char *)&h.payload);
 372         if (l == -1)
 373                 return -1;
 374         s = dns_add_query(&h);
 375         if (s == NULL)
 376                 return -1;
 377         s->_class = 1;
 378         s->type = DNS_QRY_A;
 379         s->want_list = 1;
 380         if (dns_send_requests(&h,s,l) == -1)
 381                 return -1;
 382
 383         return s->fd;
 384 }
 385
 386 int DNS::dns_getname4(const in_addr *ip) { /* build, add and send PTR query; retrieve result with dns_getresult() */
 387         char query[512];
 388         s_header h;
 389         s_connection * s;
 390         unsigned char *c;
 391         int l;
 392
 393         c = (unsigned char *)&ip->s_addr;
 394
 395         sprintf(query,"%d.%d.%d.%d.in-addr.arpa",c[3],c[2],c[1],c[0]);
 396
 397         l = dns_build_query_payload(query,DNS_QRY_PTR,1,(unsigned char *)&h.payload);
 398         if (l == -1)
 399                 return -1;
 400         s = dns_add_query(&h);
 401         if (s == NULL)
 402                 return -1;
 403         s->_class = 1;
 404         s->type = DNS_QRY_PTR;
 405         if (dns_send_requests(&h,s,l) == -1)
 406                 return -1;
 407
 408         return s->fd;
 409 }
 410
 411 char* DNS::dns_ntoa4(const in_addr * const ip) { /* numeric to ascii: convert 4part IP addr struct to static string */
 412         static char r[256];
 413         return dns_ntoa4_s(ip,r);
 414 }
 415
 416 char* DNS::dns_ntoa4_s(const in_addr *ip, char *r) { /* numeric to ascii (buffered): convert 4part IP addr struct to given string */
 417         unsigned char *m;
 418         m = (unsigned char *)&ip->s_addr;
 419         sprintf(r,"%d.%d.%d.%d",m[0],m[1],m[2],m[3]);
 420         return r;
 421 }
 422
 423 char* DNS::dns_getresult(const int cfd) { /* retrieve result of DNS query */
 424         log(DEBUG,"DNS: dns_getresult with cfd=%d",cfd);
 425         return dns_getresult_s(cfd,this->localbuf);
 426 }
 427
 428 char* DNS::dns_getresult_s(const int cfd, char *res) { /* retrieve result of DNS query (buffered) */
 429         s_header h;
 430         s_connection *c, *prev;
 431         int l,i,q,curanswer,o;
 432         s_rr_middle rr;
 433         unsigned char buffer[sizeof(s_header)];
 434         unsigned short p;
 435
 436         if (res)
 437         {
 438                 res[0] = 0;
 439         }
 440
 441         prev = NULL;
 442         c = connection_head;
 443         while (c != NULL) { /* find query in list of open queries */
 444                 if (c->fd == cfd)
 445                         break;
 446                 prev = c;
 447                 c = c->next;
 448         }
 449         if (c == NULL) {
 450                 log(DEBUG,"DNS: got a response for a query we didnt send with fd=%d",cfd);
 451                 return NULL; /* query not found */
 452         }
 453         /* query found-- pull from list: */
 454         if (prev != NULL)
 455                 prev->next = c->next;
 456         else
 457                 connection_head = c->next;
 458
 459         l = recv(c->fd,buffer,sizeof(s_header),0);
 460         dns_close(c->fd);
 461         if (l < 12) {
 462                 delete c;
 463                 return NULL;
 464         }
 465         dns_fill_header(&h,buffer,l - 12);
 466         if (c->id[0] != h.id[0] || c->id[1] != h.id[1]) {
 467                 log(DEBUG,"DNS: id mismatch on query");
 468                 delete c;
 469                 return NULL; /* ID mismatch */
 470         }
 471         if ((h.flags1 & FLAGS1_MASK_QR) == 0) {
 472                 log(DEBUG,"DNS: didnt get a query result");
 473                 delete c;
 474                 return NULL;
 475         }
 476         if ((h.flags1 & FLAGS1_MASK_OPCODE) != 0) {
 477                 log(DEBUG,"DNS: got an OPCODE and didnt want one");
 478                 delete c;
 479                 return NULL;
 480         }
 481         if ((h.flags2 & FLAGS2_MASK_RCODE) != 0) {
 482                 log(DEBUG,"DNS lookup failed due to SERVFAIL");
 483                 delete c;
 484                 return NULL;
 485         }
 486         if (h.ancount < 1)  { /* no sense going on if we don't have any answers */
 487                 log(DEBUG,"DNS: no answers!");
 488                 delete c;
 489                 return NULL;
 490         }
 491         /* skip queries */
 492         i = 0;
 493         q = 0;
 494         l -= 12;
 495         while ((unsigned)q < h.qdcount && i < l) {
 496                 if (h.payload[i] > 63) { /* pointer */
 497                         i += 6; /* skip pointer, _class and type */
 498                         q++;
 499                 } else { /* label */
 500                         if (h.payload[i] == 0) {
 501                                 q++;
 502                                 i += 5; /* skip nil, _class and type */
 503                         } else
 504                                 i += h.payload[i] + 1; /* skip length and label */
 505                 }
 506         }
 507         /* &h.payload[i] should now be the start of the first response */
 508         curanswer = 0;
 509         while ((unsigned)curanswer < h.ancount) {
 510                 q = 0;
 511                 while (q == 0 && i < l) {
 512                         if (h.payload[i] > 63) { /* pointer */
 513                                 i += 2; /* skip pointer */
 514                                 q = 1;
 515                         } else { /* label */
 516                                 if (h.payload[i] == 0) {
 517                                         i++;
 518                                         q = 1;
 519                                 } else
 520                                         i += h.payload[i] + 1; /* skip length and label */
 521                         }
 522                 }
 523                 if (l - i < 10) {
 524                         delete c;
 525                         return NULL;
 526                 }
 527                 dns_fill_rr(&rr,&h.payload[i]);
 528                 i += 10;
 529                 if (rr.type != c->type) {
 530                         curanswer++;
 531                         i += rr.rdlength;
 532                         continue;
 533                 }
 534                 if (rr._class != c->_class) {
 535                         curanswer++;
 536                         i += rr.rdlength;
 537                         continue;
 538                 }
 539                 break;
 540         }
 541         if ((unsigned)curanswer == h.ancount)
 542                 return NULL;
 543         if ((unsigned)i + rr.rdlength > (unsigned)l)
 544                 return NULL;
 545         if (rr.rdlength > 1023)
 546                 return NULL;
 547
 548         switch (rr.type) {
 549                 case DNS_QRY_PTR:
 550                         log(DEBUG,"DNS: got a result of type DNS_QRY_PTR");
 551                         o = 0;
 552                         q = 0;
 553                         while (q == 0 && i < l && o + 256 < 1023) {
 554                                 if (h.payload[i] > 63) { /* pointer */
 555                                         memcpy(&p,&h.payload[i],2);
 556                                         i = ntohs(p) - DNS_POINTER_VALUE - 12;
 557                                 } else { /* label */
 558                                         if (h.payload[i] == 0)
 559                                                 q = 1;
 560                                         else {
 561                                                 res[o] = '\0';
 562                                                 if (o != 0)
 563                                                         res[o++] = '.';
 564                                                 memcpy(&res[o],&h.payload[i + 1],h.payload[i]);
 565                                                 o += h.payload[i];
 566                                                 i += h.payload[i] + 1;
 567                                         }
 568                                 }
 569                         }
 570                         res[o] = '\0';
 571                         break;
 572                 case DNS_QRY_A:
 573                         log(DEBUG,"DNS: got a result of type DNS_QRY_A");
 574                         if (c->want_list) {
 575                                 dns_ip4list *alist = (dns_ip4list *) res; /* we have to trust that this is aligned */
 576                                 while ((char *)alist - (char *)res < 700) {
 577                                         if (rr.type != DNS_QRY_A)
 578                                                 break;
 579                                         if (rr._class != 1)
 580                                                 break;
 581                                         if (rr.rdlength != 4) {
 582                                                 delete c;
 583                                                 return NULL;
 584                                         }
 585                                         memcpy(&alist->ip,&h.payload[i],4);
 586                                         if ((unsigned)++curanswer >= h.ancount)
 587                                                 break;
 588                                         i += rr.rdlength;
 589                                         {
 590                                                 /* skip next name */
 591                                                 q = 0;
 592                                                 while (q == 0 && i < l) {
 593                                                         if (h.payload[i] > 63) { /* pointer */
 594                                                                 i += 2; /* skip pointer */
 595                                                                 q = 1;
 596                                                         } else { /* label */
 597                                                                 if (h.payload[i] == 0) {
 598                                                                         i++;
 599                                                                         q = 1;
 600                                                                 } else
 601                                                                         i += h.payload[i] + 1; /* skip length and label */
 602                                                         }
 603                                                 }
 604                                         }
 605                                         if (l - i < 10) {
 606                                                 delete c;
 607                                                 return NULL;
 608                                         }
 609                                         dns_fill_rr(&rr,&h.payload[i]);
 610                                         i += 10;
 611                                         alist->next = (dns_ip4list *) dns_align(((char *) alist) + sizeof(dns_ip4list));
 612                                         alist = alist->next;
 613                                         alist->next = NULL;
 614                                 }
 615                                 alist->next = NULL;
 616                                 break;
 617                         }
 618                         goto defaultcase;
 619                         break;
 620                 default:
 621                 defaultcase:
 622                         log(DEBUG,"DNS: doing something with result 'default'");
 623                         memcpy(res,&h.payload[i],rr.rdlength);
 624                         res[rr.rdlength] = '\0';
 625                         break;
 626         }
 627         delete c;
 628         return res;
 629 }
 630
 631 DNS::DNS()
 632 {
 633         dns_init();
 634         log(DEBUG,"Create blank DNS");
 635 }
 636
 637 DNS::DNS(std::string dnsserver)
 638 {
 639         dns_init_2(dnsserver.c_str());
 640         log(DEBUG,"Create DNS");
 641 }
 642
 643 void DNS::SetNS(std::string dnsserver)
 644 {
 645         dns_init_2(dnsserver.c_str());
 646         log(DEBUG,"Set NS");
 647 }
 648
 649 DNS::~DNS()
 650 {
 651 }
 652
 653 bool DNS::ReverseLookup(std::string ip)
 654 {
 655         statsDns++;
 656         binip = dns_aton4(ip.c_str());
 657         if (binip == NULL) {
 658                 return false;
 659         }
 660
 661         this->myfd = dns_getname4(binip);
 662         if (this->myfd == -1)
 663         {
 664                 return false;
 665         }
 666         log(DEBUG,"DNS: ReverseLookup, fd=%d",this->myfd);
 667         return true;
 668 }
 669
 670 bool DNS::ForwardLookup(std::string host)
 671 {
 672         statsDns++;
 673         this->myfd = dns_getip4(host.c_str());
 674         if (this->myfd == -1)
 675         {
 676                 return false;
 677         }
 678         log(DEBUG,"DNS: ForwardLookup, fd=%d",this->myfd);
 679         return true;
 680 }
 681
 682 bool DNS::HasResult()
 683 {
 684         log(DEBUG,"DNS: HasResult, fd=%d",this->myfd);
 685         pollfd polls;
 686         polls.fd = this->myfd;
 687         polls.events = POLLIN;
 688         int ret = poll(&polls,1,1);
 689         log(DEBUG,"DNS: Hasresult returning %d",ret);
 690         return (ret > 0);
 691 }
 692
 693 int DNS::GetFD()
 694 {
 695         return this->myfd;
 696 }
 697
 698 std::string DNS::GetResult()
 699 {
 700         log(DEBUG,"DNS: GetResult()");
 701         result = dns_getresult(this->myfd);
 702         if (result) {
 703                 statsDnsGood++;
 704                 dns_close(this->myfd);
 705                 return result;
 706         } else {
 707                 statsDnsBad++;
 708                 if (this->myfd != -1)
 709                 {
 710                         dns_close(this->myfd);
 711                 }
 712                 return "";
 713         }
 714 }
 715
 716 std::string DNS::GetResultIP()
 717 {
 718         char r[1024];
 719         log(DEBUG,"DNS: GetResultIP()");
 720         result = dns_getresult(this->myfd);
 721         if (this->myfd != -1)
 722         {
 723                 dns_close(this->myfd);
 724         }
 725         if (result)
 726         {
 727                 statsDnsGood++;
 728                 unsigned char a = (unsigned)result[0];
 729                 unsigned char b = (unsigned)result[1];
 730                 unsigned char c = (unsigned)result[2];
 731                 unsigned char d = (unsigned)result[3];
 732                 snprintf(r,1024,"%u.%u.%u.%u",a,b,c,d);
 733                 return r;
 734         }
 735         else
 736         {
 737                 statsDnsBad++;
 738                 log(DEBUG,"DANGER WILL ROBINSON! NXDOMAIN for forward lookup, but we got a reverse lookup!");
 739                 return "";
 740         }
 741 }
 742