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 #include "socketengine.h"
  41
  42 extern SocketEngine* SE;
  43 serverstats* stats;
  44
  45 #define max(a,b) (a > b ? a : b)
  46 #define DNS_MAX              8                    /* max number of nameservers used */
  47 #define DNS_CONFIG_FBCK     "/etc/resolv.conf"    /* fallback config file */
  48 #define DNS_PORT            53                    /* DNS well known port */
  49 #define DNS_QRY_A            1                    /* name to IP address */
  50 #define DNS_QRY_AAAA        28                    /* name to IP6 address */
  51 #define DNS_QRY_PTR         12                    /* IP address to name */
  52 #define DNS_QRY_MX          15                    /* name to MX */
  53 #define DNS_QRY_TXT         16                    /* name to TXT */
  54 #define DNS_QRY_CNAME       5
  55
  56 #define DNS_ALIGN (sizeof(void *) > sizeof(long) ? sizeof(void *) : sizeof(long))
  57 #define DNS_TRIES 3
  58 #define RESULTSIZE 1024
  59 #define min(a,b) (a < b ? a : b)
  60
  61 static struct in_addr servers4[DNS_MAX]; /* up to DNS_MAX nameservers; populated by dns_init() */
  62 static int i4; /* actual count of nameservers; set by dns_init() */
  63
  64 static int initdone = 0; /* to ensure dns_init() only runs once (on the first call) */
  65 static int wantclose = 0;
  66 static int lastcreate = -1;
  67
  68 struct s_connection { /* open DNS query */
  69         struct s_connection *next; /* next in list */
  70         unsigned char id[2];
  71         unsigned int _class;
  72         unsigned int type;
  73         int want_list;
  74         int fd; /* file descriptor returned from sockets */
  75 };
  76
  77 struct s_rr_middle {
  78         unsigned int type;
  79         unsigned int _class;
  80         unsigned long ttl;
  81         unsigned int rdlength;
  82 };
  83
  84 #define DNS_POINTER_VALUE 0xc000
  85
  86 static s_connection *connection_head = NULL; /* linked list of open DNS queries; populated by dns_add_query(), decimated by dns_getresult_s() */
  87
  88 struct s_header { /* DNS query header */
  89         unsigned char id[2];
  90         unsigned int flags1;
  91 #define FLAGS1_MASK_QR 0x80
  92 #define FLAGS1_MASK_OPCODE 0x78 /* bitshift right 3 */
  93 #define FLAGS1_MASK_AA 0x04
  94 #define FLAGS1_MASK_TC 0x02
  95 #define FLAGS1_MASK_RD 0x01
  96         unsigned int flags2;
  97 #define FLAGS2_MASK_RA 0x80
  98 #define FLAGS2_MASK_Z  0x70
  99 #define FLAGS2_MASK_RCODE 0x0f
 100         unsigned int qdcount;
 101         unsigned int ancount;
 102         unsigned int nscount;
 103         unsigned int arcount;
 104         unsigned char payload[512]; /* DNS question, populated by dns_build_query_payload() */
 105 };
 106
 107 extern time_t TIME;
 108
 109 void *dns_align(void *inp) {
 110         char *p = (char*)inp;
 111         int offby = ((char *)p - (char *)0) % DNS_ALIGN;
 112         if (offby != 0)
 113                 return p + (DNS_ALIGN - offby);
 114         else
 115                 return p;
 116 }
 117
 118 /*
 119  * These little hacks are here to avoid alignment and type sizing issues completely by doing manual copies
 120  */
 121 void dns_fill_rr(s_rr_middle* rr, const unsigned char *input) {
 122         rr->type = input[0] * 256 + input[1];
 123         rr->_class = input[2] * 256 + input[3];
 124         rr->ttl = input[4] * 16777216 + input[5] * 65536 + input[6] * 256 + input[7];
 125         rr->rdlength = input[8] * 256 + input[9];
 126 }
 127
 128 void dns_fill_header(s_header *header, const unsigned char *input, const int l) {
 129         header->id[0] = input[0];
 130         header->id[1] = input[1];
 131         header->flags1 = input[2];
 132         header->flags2 = input[3];
 133         header->qdcount = input[4] * 256 + input[5];
 134         header->ancount = input[6] * 256 + input[7];
 135         header->nscount = input[8] * 256 + input[9];
 136         header->arcount = input[10] * 256 + input[11];
 137         memcpy(header->payload,&input[12],l);
 138 }
 139
 140 void dns_empty_header(unsigned char *output, const s_header *header, const int l) {
 141         output[0] = header->id[0];
 142         output[1] = header->id[1];
 143         output[2] = header->flags1;
 144         output[3] = header->flags2;
 145         output[4] = header->qdcount / 256;
 146         output[5] = header->qdcount % 256;
 147         output[6] = header->ancount / 256;
 148         output[7] = header->ancount % 256;
 149         output[8] = header->nscount / 256;
 150         output[9] = header->nscount % 256;
 151         output[10] = header->arcount / 256;
 152         output[11] = header->arcount % 256;
 153         memcpy(&output[12],header->payload,l);
 154 }
 155
 156 void dns_close(int fd) { /* close query */
 157         log(DEBUG,"DNS: dns_close on fd %d",fd);
 158         if (fd == lastcreate) {
 159                 wantclose = 1;
 160                 return;
 161         }
 162         shutdown(fd,2);
 163         close(fd);
 164         return;
 165 }
 166
 167 void DNS::dns_init() { /* on first call only: populates servers4 struct with up to DNS_MAX nameserver IP addresses from /etc/resolv.conf */
 168         FILE *f;
 169         int i;
 170         in_addr addr4;
 171         char buf[1024];
 172         if (initdone == 1)
 173                 return;
 174         i4 = 0;
 175
 176         initdone = 1;
 177         srand((unsigned int) TIME);
 178         memset(servers4,'\0',sizeof(in_addr) * DNS_MAX);
 179         f = fopen(DNS_CONFIG_FBCK,"r");
 180         if (f == NULL)
 181                 return;
 182         while (fgets(buf,1024,f) != NULL) {
 183                 if (strncmp(buf,"nameserver",10) == 0) {
 184                         i = 10;
 185                         while (buf[i] == ' ' || buf[i] == '\t')
 186                                 i++;
 187                         if (i4 < DNS_MAX) {
 188                                 if (dns_aton4_s(&buf[i],&addr4) != NULL)
 189                                         memcpy(&servers4[i4++],&addr4,sizeof(in_addr));
 190                         }
 191                 }
 192         }
 193         fclose(f);
 194 }
 195
 196 void DNS::dns_init_2(const char* dnsserver)
 197 {
 198         in_addr addr4;
 199         i4 = 0;
 200         srand((unsigned int) TIME);
 201         memset(servers4,'\0',sizeof(in_addr) * DNS_MAX);
 202         if (dns_aton4_s(dnsserver,&addr4) != NULL)
 203             memcpy(&servers4[i4++],&addr4,sizeof(in_addr));
 204 }
 205
 206
 207 static int dns_send_requests(const s_header *h, const s_connection *s, const int l)
 208 {
 209         int i;
 210         sockaddr_in addr4;
 211         unsigned char payload[sizeof(s_header)];
 212
 213         dns_empty_header(payload,h,l);
 214
 215
 216         i = 0;
 217
 218         /* otherwise send via standard ipv4 boringness */
 219         memset(&addr4,0,sizeof(addr4));
 220         memcpy(&addr4.sin_addr,&servers4[i],sizeof(addr4.sin_addr));
 221         addr4.sin_family = AF_INET;
 222         addr4.sin_port = htons(DNS_PORT);
 223         if (sendto(s->fd, payload, l + 12, 0, (sockaddr *) &addr4, sizeof(addr4)) == -1)
 224         {
 225                 return -1;
 226         }
 227
 228         return 0;
 229 }
 230
 231 static s_connection *dns_add_query(s_header *h) { /* build DNS query, add to list */
 232         s_connection * s;
 233
 234         s = new s_connection;
 235
 236         /* set header flags */
 237         h->id[0] = s->id[0] = rand() % 255; /* verified by dns_getresult_s() */
 238         h->id[1] = s->id[1] = rand() % 255;
 239         h->flags1 = 0 | FLAGS1_MASK_RD;
 240         h->flags2 = 0;
 241         h->qdcount = 1;
 242         h->ancount = 0;
 243         h->nscount = 0;
 244         h->arcount = 0;
 245
 246         /* turn off want_list by default */
 247         s->want_list = 0;
 248
 249         /* try to create ipv6 or ipv4 socket */
 250                 s->fd = socket(PF_INET, SOCK_DGRAM, 0);
 251                 if (s->fd != -1) {
 252                         if (fcntl(s->fd, F_SETFL, O_NONBLOCK) != 0) {
 253                                 shutdown(s->fd,2);
 254                                 close(s->fd);
 255                                 s->fd = -1;
 256                         }
 257                 }
 258                 if (s->fd != -1) {
 259                         sockaddr_in addr;
 260                         memset(&addr,0,sizeof(addr));
 261                         addr.sin_family = AF_INET;
 262                         addr.sin_port = 0;
 263                         addr.sin_addr.s_addr = INADDR_ANY;
 264                         if (bind(s->fd,(sockaddr *)&addr,sizeof(addr)) != 0) {
 265                                 shutdown(s->fd,2);
 266                                 close(s->fd);
 267                                 s->fd = -1;
 268                         }
 269                 }
 270                 if (s->fd == -1) {
 271                         delete s;
 272                         return NULL;
 273                 }
 274         /* create new connection object, add to linked list */
 275         s->next = connection_head;
 276         connection_head = s;
 277
 278         if (wantclose == 1) {
 279                 shutdown(lastcreate,2);
 280                 close(lastcreate);
 281                 wantclose = 0;
 282         }
 283         lastcreate = s->fd;
 284         return s;
 285 }
 286
 287 static int dns_build_query_payload(const char * const name, const unsigned short rr, const unsigned short _class, unsigned char * const payload) {
 288         short payloadpos;
 289         const char * tempchr, * tempchr2;
 290         unsigned short l;
 291
 292         payloadpos = 0;
 293         tempchr2 = name;
 294
 295         /* split name up into labels, create query */
 296         while ((tempchr = strchr(tempchr2,'.')) != NULL) {
 297                 l = tempchr - tempchr2;
 298                 if (payloadpos + l + 1 > 507)
 299                         return -1;
 300                 payload[payloadpos++] = l;
 301                 memcpy(&payload[payloadpos],tempchr2,l);
 302                 payloadpos += l;
 303                 tempchr2 = &tempchr[1];
 304         }
 305         l = strlen(tempchr2);
 306         if (l) {
 307                 if (payloadpos + l + 2 > 507)
 308                         return -1;
 309                 payload[payloadpos++] = l;
 310                 memcpy(&payload[payloadpos],tempchr2,l);
 311                 payloadpos += l;
 312                 payload[payloadpos++] = '\0';
 313         }
 314         if (payloadpos > 508)
 315                 return -1;
 316         l = htons(rr);
 317         memcpy(&payload[payloadpos],&l,2);
 318         l = htons(_class);
 319         memcpy(&payload[payloadpos + 2],&l,2);
 320         return payloadpos + 4;
 321 }
 322
 323 in_addr* DNS::dns_aton4(const char * const ipstring) { /* ascii to numeric: convert string to static 4part IP addr struct */
 324         static in_addr ip;
 325         return dns_aton4_s(ipstring,&ip);
 326 }
 327
 328 in_addr* DNS::dns_aton4_r(const char *ipstring) { /* ascii to numeric (reentrant): convert string to new 4part IP addr struct */
 329         in_addr* ip;
 330         ip = new in_addr;
 331         if(dns_aton4_s(ipstring,ip) == NULL) {
 332                 delete ip;
 333                 return NULL;
 334         }
 335         return ip;
 336 }
 337
 338 in_addr* DNS::dns_aton4_s(const char *ipstring, in_addr *ip) { /* ascii to numeric (buffered): convert string to given 4part IP addr struct */
 339         inet_aton(ipstring,ip);
 340         return ip;
 341 }
 342
 343 int DNS::dns_getip4(const char *name) { /* build, add and send A query; retrieve result with dns_getresult() */
 344         s_header h;
 345         s_connection *s;
 346         int l;
 347
 348         dns_init();
 349
 350
 351         l = dns_build_query_payload(name,DNS_QRY_A,1,(unsigned char *)&h.payload);
 352         if (l == -1)
 353                 return -1;
 354         s = dns_add_query(&h);
 355         if (s == NULL)
 356                 return -1;
 357         s->_class = 1;
 358         s->type = DNS_QRY_A;
 359         if (dns_send_requests(&h,s,l) == -1)
 360                 return -1;
 361
 362         return s->fd;
 363 }
 364
 365 int DNS::dns_getip4list(const char *name) { /* build, add and send A query; retrieve result with dns_getresult() */
 366         s_header h;
 367         s_connection *s;
 368         int l;
 369
 370         dns_init();
 371
 372
 373         l = dns_build_query_payload(name,DNS_QRY_A,1,(unsigned char *)&h.payload);
 374         if (l == -1)
 375                 return -1;
 376         s = dns_add_query(&h);
 377         if (s == NULL)
 378                 return -1;
 379         s->_class = 1;
 380         s->type = DNS_QRY_A;
 381         s->want_list = 1;
 382         if (dns_send_requests(&h,s,l) == -1)
 383                 return -1;
 384
 385         return s->fd;
 386 }
 387
 388 int DNS::dns_getname4(const in_addr *ip) { /* build, add and send PTR query; retrieve result with dns_getresult() */
 389         char query[512];
 390         s_header h;
 391         s_connection * s;
 392         unsigned char *c;
 393         int l;
 394
 395         c = (unsigned char *)&ip->s_addr;
 396
 397         sprintf(query,"%d.%d.%d.%d.in-addr.arpa",c[3],c[2],c[1],c[0]);
 398
 399         l = dns_build_query_payload(query,DNS_QRY_PTR,1,(unsigned char *)&h.payload);
 400         if (l == -1)
 401                 return -1;
 402         s = dns_add_query(&h);
 403         if (s == NULL)
 404                 return -1;
 405         s->_class = 1;
 406         s->type = DNS_QRY_PTR;
 407         if (dns_send_requests(&h,s,l) == -1)
 408                 return -1;
 409
 410         return s->fd;
 411 }
 412
 413 char* DNS::dns_ntoa4(const in_addr * const ip) { /* numeric to ascii: convert 4part IP addr struct to static string */
 414         static char r[256];
 415         return dns_ntoa4_s(ip,r);
 416 }
 417
 418 char* DNS::dns_ntoa4_s(const in_addr *ip, char *r) { /* numeric to ascii (buffered): convert 4part IP addr struct to given string */
 419         unsigned char *m;
 420         m = (unsigned char *)&ip->s_addr;
 421         sprintf(r,"%d.%d.%d.%d",m[0],m[1],m[2],m[3]);
 422         return r;
 423 }
 424
 425 char* DNS::dns_getresult(const int cfd) { /* retrieve result of DNS query */
 426         log(DEBUG,"DNS: dns_getresult with cfd=%d",cfd);
 427         return dns_getresult_s(cfd,this->localbuf);
 428 }
 429
 430 char* DNS::dns_getresult_s(const int cfd, char *res) { /* retrieve result of DNS query (buffered) */
 431         s_header h;
 432         s_connection *c, *prev;
 433         int l,i,q,curanswer,o;
 434         s_rr_middle rr;
 435         unsigned char buffer[sizeof(s_header)];
 436         unsigned short p;
 437
 438         if (res)
 439         {
 440                 res[0] = 0;
 441         }
 442
 443         prev = NULL;
 444         c = connection_head;
 445         while (c != NULL) { /* find query in list of open queries */
 446                 if (c->fd == cfd)
 447                         break;
 448                 prev = c;
 449                 c = c->next;
 450         }
 451         if (c == NULL) {
 452                 log(DEBUG,"DNS: got a response for a query we didnt send with fd=%d",cfd);
 453                 return NULL; /* query not found */
 454         }
 455         /* query found-- pull from list: */
 456         if (prev != NULL)
 457                 prev->next = c->next;
 458         else
 459                 connection_head = c->next;
 460
 461         l = recv(c->fd,buffer,sizeof(s_header),0);
 462         dns_close(c->fd);
 463         if (l < 12) {
 464                 delete c;
 465                 return NULL;
 466         }
 467         dns_fill_header(&h,buffer,l - 12);
 468         if (c->id[0] != h.id[0] || c->id[1] != h.id[1]) {
 469                 log(DEBUG,"DNS: id mismatch on query");
 470                 delete c;
 471                 return NULL; /* ID mismatch */
 472         }
 473         if ((h.flags1 & FLAGS1_MASK_QR) == 0) {
 474                 log(DEBUG,"DNS: didnt get a query result");
 475                 delete c;
 476                 return NULL;
 477         }
 478         if ((h.flags1 & FLAGS1_MASK_OPCODE) != 0) {
 479                 log(DEBUG,"DNS: got an OPCODE and didnt want one");
 480                 delete c;
 481                 return NULL;
 482         }
 483         if ((h.flags2 & FLAGS2_MASK_RCODE) != 0) {
 484                 log(DEBUG,"DNS lookup failed due to SERVFAIL");
 485                 delete c;
 486                 return NULL;
 487         }
 488         if (h.ancount < 1)  { /* no sense going on if we don't have any answers */
 489                 log(DEBUG,"DNS: no answers!");
 490                 delete c;
 491                 return NULL;
 492         }
 493         /* skip queries */
 494         i = 0;
 495         q = 0;
 496         l -= 12;
 497         while ((unsigned)q < h.qdcount && i < l) {
 498                 if (h.payload[i] > 63) { /* pointer */
 499                         i += 6; /* skip pointer, _class and type */
 500                         q++;
 501                 } else { /* label */
 502                         if (h.payload[i] == 0) {
 503                                 q++;
 504                                 i += 5; /* skip nil, _class and type */
 505                         } else
 506                                 i += h.payload[i] + 1; /* skip length and label */
 507                 }
 508         }
 509         /* &h.payload[i] should now be the start of the first response */
 510         curanswer = 0;
 511         while ((unsigned)curanswer < h.ancount) {
 512                 q = 0;
 513                 while (q == 0 && i < l) {
 514                         if (h.payload[i] > 63) { /* pointer */
 515                                 i += 2; /* skip pointer */
 516                                 q = 1;
 517                         } else { /* label */
 518                                 if (h.payload[i] == 0) {
 519                                         i++;
 520                                         q = 1;
 521                                 } else
 522                                         i += h.payload[i] + 1; /* skip length and label */
 523                         }
 524                 }
 525                 if (l - i < 10) {
 526                         delete c;
 527                         return NULL;
 528                 }
 529                 dns_fill_rr(&rr,&h.payload[i]);
 530                 i += 10;
 531                 if (rr.type != c->type) {
 532                         curanswer++;
 533                         i += rr.rdlength;
 534                         continue;
 535                 }
 536                 if (rr._class != c->_class) {
 537                         curanswer++;
 538                         i += rr.rdlength;
 539                         continue;
 540                 }
 541                 break;
 542         }
 543         if ((unsigned)curanswer == h.ancount)
 544                 return NULL;
 545         if ((unsigned)i + rr.rdlength > (unsigned)l)
 546                 return NULL;
 547         if (rr.rdlength > 1023)
 548                 return NULL;
 549
 550         switch (rr.type) {
 551                 case DNS_QRY_PTR:
 552                         log(DEBUG,"DNS: got a result of type DNS_QRY_PTR");
 553                         o = 0;
 554                         q = 0;
 555                         while (q == 0 && i < l && o + 256 < 1023) {
 556                                 if (h.payload[i] > 63) { /* pointer */
 557                                         memcpy(&p,&h.payload[i],2);
 558                                         i = ntohs(p) - DNS_POINTER_VALUE - 12;
 559                                 } else { /* label */
 560                                         if (h.payload[i] == 0)
 561                                                 q = 1;
 562                                         else {
 563                                                 res[o] = '\0';
 564                                                 if (o != 0)
 565                                                         res[o++] = '.';
 566                                                 memcpy(&res[o],&h.payload[i + 1],h.payload[i]);
 567                                                 o += h.payload[i];
 568                                                 i += h.payload[i] + 1;
 569                                         }
 570                                 }
 571                         }
 572                         res[o] = '\0';
 573                         break;
 574                 case DNS_QRY_A:
 575                         log(DEBUG,"DNS: got a result of type DNS_QRY_A");
 576                         if (c->want_list) {
 577                                 dns_ip4list *alist = (dns_ip4list *) res; /* we have to trust that this is aligned */
 578                                 while ((char *)alist - (char *)res < 700) {
 579                                         if (rr.type != DNS_QRY_A)
 580                                                 break;
 581                                         if (rr._class != 1)
 582                                                 break;
 583                                         if (rr.rdlength != 4) {
 584                                                 delete c;
 585                                                 return NULL;
 586                                         }
 587                                         memcpy(&alist->ip,&h.payload[i],4);
 588                                         if ((unsigned)++curanswer >= h.ancount)
 589                                                 break;
 590                                         i += rr.rdlength;
 591                                         {
 592                                                 /* skip next name */
 593                                                 q = 0;
 594                                                 while (q == 0 && i < l) {
 595                                                         if (h.payload[i] > 63) { /* pointer */
 596                                                                 i += 2; /* skip pointer */
 597                                                                 q = 1;
 598                                                         } else { /* label */
 599                                                                 if (h.payload[i] == 0) {
 600                                                                         i++;
 601                                                                         q = 1;
 602                                                                 } else
 603                                                                         i += h.payload[i] + 1; /* skip length and label */
 604                                                         }
 605                                                 }
 606                                         }
 607                                         if (l - i < 10) {
 608                                                 delete c;
 609                                                 return NULL;
 610                                         }
 611                                         dns_fill_rr(&rr,&h.payload[i]);
 612                                         i += 10;
 613                                         alist->next = (dns_ip4list *) dns_align(((char *) alist) + sizeof(dns_ip4list));
 614                                         alist = alist->next;
 615                                         alist->next = NULL;
 616                                 }
 617                                 alist->next = NULL;
 618                                 break;
 619                         }
 620                         goto defaultcase;
 621                         break;
 622                 default:
 623                 defaultcase:
 624                         log(DEBUG,"DNS: doing something with result 'default'");
 625                         memcpy(res,&h.payload[i],rr.rdlength);
 626                         res[rr.rdlength] = '\0';
 627                         break;
 628         }
 629         delete c;
 630         return res;
 631 }
 632
 633 DNS::DNS()
 634 {
 635         dns_init();
 636         log(DEBUG,"Create blank DNS");
 637 }
 638
 639 DNS::DNS(std::string dnsserver)
 640 {
 641         dns_init_2(dnsserver.c_str());
 642         log(DEBUG,"Create DNS");
 643 }
 644
 645 void DNS::SetNS(std::string dnsserver)
 646 {
 647         dns_init_2(dnsserver.c_str());
 648         log(DEBUG,"Set NS");
 649 }
 650
 651 DNS::~DNS()
 652 {
 653 }
 654
 655 bool DNS::ReverseLookup(std::string ip)
 656 {
 657         stats->statsDns++;
 658         binip = dns_aton4(ip.c_str());
 659         if (binip == NULL) {
 660                 return false;
 661         }
 662
 663         this->myfd = dns_getname4(binip);
 664         if (this->myfd == -1)
 665         {
 666                 return false;
 667         }
 668         log(DEBUG,"DNS: ReverseLookup, fd=%d",this->myfd);
 669 #ifndef THREADED_DNS
 670         SE->AddFd(this->myfd,true,X_ESTAB_DNS);
 671 #endif
 672         return true;
 673 }
 674
 675 bool DNS::ForwardLookup(std::string host)
 676 {
 677         stats->statsDns++;
 678         this->myfd = dns_getip4(host.c_str());
 679         if (this->myfd == -1)
 680         {
 681                 return false;
 682         }
 683         log(DEBUG,"DNS: ForwardLookup, fd=%d",this->myfd);
 684 #ifndef THREADED_DNS
 685         SE->AddFd(this->myfd,true,X_ESTAB_DNS);
 686 #endif
 687         return true;
 688 }
 689
 690 bool DNS::HasResult(int fd)
 691 {
 692         return (fd == this->myfd);
 693 }
 694
 695 /* Only the multithreaded dns uses this poll() based
 696  * check now. As its in another thread we dont have
 697  * to worry about its performance that much.
 698  */
 699 bool DNS::HasResult()
 700 {
 701         log(DEBUG,"DNS: HasResult, fd=%d",this->myfd);
 702         pollfd polls;
 703         polls.fd = this->myfd;
 704         polls.events = POLLIN;
 705         int ret = poll(&polls,1,1);
 706         log(DEBUG,"DNS: Hasresult returning %d",ret);
 707         return (ret > 0);
 708 }
 709
 710 int DNS::GetFD()
 711 {
 712         return this->myfd;
 713 }
 714
 715 std::string DNS::GetResult()
 716 {
 717         log(DEBUG,"DNS: GetResult()");
 718         result = dns_getresult(this->myfd);
 719 #ifndef THREADED_DNS
 720         SE->DelFd(this->myfd);
 721 #endif
 722         if (result) {
 723                 stats->statsDnsGood++;
 724                 dns_close(this->myfd);
 725                 return result;
 726         } else {
 727                 stats->statsDnsBad++;
 728                 if (this->myfd != -1)
 729                 {
 730                         dns_close(this->myfd);
 731                 }
 732                 return "";
 733         }
 734 }
 735
 736 std::string DNS::GetResultIP()
 737 {
 738         char r[1024];
 739         log(DEBUG,"DNS: GetResultIP()");
 740         result = dns_getresult(this->myfd);
 741         if (this->myfd != -1)
 742         {
 743 #ifndef THREADED_DNS
 744                 SE->DelFd(this->myfd);
 745 #endif
 746                 dns_close(this->myfd);
 747         }
 748         if (result)
 749         {
 750                 stats->statsDnsGood++;
 751                 unsigned char a = (unsigned)result[0];
 752                 unsigned char b = (unsigned)result[1];
 753                 unsigned char c = (unsigned)result[2];
 754                 unsigned char d = (unsigned)result[3];
 755                 snprintf(r,1024,"%u.%u.%u.%u",a,b,c,d);
 756                 return r;
 757         }
 758         else
 759         {
 760                 stats->statsDnsBad++;
 761                 log(DEBUG,"DANGER WILL ROBINSON! NXDOMAIN for forward lookup, but we got a reverse lookup!");
 762                 return "";
 763         }
 764 }
 765