resolve.c revision 55682
155682Smarkm/* 255682Smarkm * Copyright (c) 1995, 1996, 1997, 1998, 1999 Kungliga Tekniska H�gskolan 355682Smarkm * (Royal Institute of Technology, Stockholm, Sweden). 455682Smarkm * All rights reserved. 555682Smarkm * 655682Smarkm * Redistribution and use in source and binary forms, with or without 755682Smarkm * modification, are permitted provided that the following conditions 855682Smarkm * are met: 955682Smarkm * 1055682Smarkm * 1. Redistributions of source code must retain the above copyright 1155682Smarkm * notice, this list of conditions and the following disclaimer. 1255682Smarkm * 1355682Smarkm * 2. Redistributions in binary form must reproduce the above copyright 1455682Smarkm * notice, this list of conditions and the following disclaimer in the 1555682Smarkm * documentation and/or other materials provided with the distribution. 1655682Smarkm * 1755682Smarkm * 3. Neither the name of the Institute nor the names of its contributors 1855682Smarkm * may be used to endorse or promote products derived from this software 1955682Smarkm * without specific prior written permission. 2055682Smarkm * 2155682Smarkm * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 2255682Smarkm * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 2355682Smarkm * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 2455682Smarkm * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 2555682Smarkm * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 2655682Smarkm * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2755682Smarkm * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2855682Smarkm * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2955682Smarkm * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 3055682Smarkm * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 3155682Smarkm * SUCH DAMAGE. 3255682Smarkm */ 3355682Smarkm 3455682Smarkm#ifdef HAVE_CONFIG_H 3555682Smarkm#include <config.h> 3655682Smarkm#endif 3755682Smarkm#include "roken.h" 3855682Smarkm#ifdef HAVE_ARPA_NAMESER_H 3955682Smarkm#include <arpa/nameser.h> 4055682Smarkm#endif 4155682Smarkm#ifdef HAVE_RESOLV_H 4255682Smarkm#include <resolv.h> 4355682Smarkm#endif 4455682Smarkm#include "resolve.h" 4555682Smarkm 4655682SmarkmRCSID("$Id: resolve.c,v 1.22 1999/12/02 16:58:52 joda Exp $"); 4755682Smarkm 4855682Smarkm#if defined(HAVE_RES_SEARCH) && defined(HAVE_DN_EXPAND) 4955682Smarkm 5055682Smarkm#define DECL(X) {#X, T_##X} 5155682Smarkm 5255682Smarkmstatic struct stot{ 5355682Smarkm const char *name; 5455682Smarkm int type; 5555682Smarkm}stot[] = { 5655682Smarkm DECL(A), 5755682Smarkm DECL(NS), 5855682Smarkm DECL(CNAME), 5955682Smarkm DECL(PTR), 6055682Smarkm DECL(MX), 6155682Smarkm DECL(TXT), 6255682Smarkm DECL(AFSDB), 6355682Smarkm DECL(SRV), 6455682Smarkm {NULL, 0} 6555682Smarkm}; 6655682Smarkm 6755682Smarkmint _resolve_debug; 6855682Smarkm 6955682Smarkmstatic int 7055682Smarkmstring_to_type(const char *name) 7155682Smarkm{ 7255682Smarkm struct stot *p = stot; 7355682Smarkm for(p = stot; p->name; p++) 7455682Smarkm if(strcasecmp(name, p->name) == 0) 7555682Smarkm return p->type; 7655682Smarkm return -1; 7755682Smarkm} 7855682Smarkm 7955682Smarkmstatic const char * 8055682Smarkmtype_to_string(int type) 8155682Smarkm{ 8255682Smarkm struct stot *p = stot; 8355682Smarkm for(p = stot; p->name; p++) 8455682Smarkm if(type == p->type) 8555682Smarkm return p->name; 8655682Smarkm return NULL; 8755682Smarkm} 8855682Smarkm 8955682Smarkmvoid 9055682Smarkmdns_free_data(struct dns_reply *r) 9155682Smarkm{ 9255682Smarkm struct resource_record *rr; 9355682Smarkm if(r->q.domain) 9455682Smarkm free(r->q.domain); 9555682Smarkm for(rr = r->head; rr;){ 9655682Smarkm struct resource_record *tmp = rr; 9755682Smarkm if(rr->domain) 9855682Smarkm free(rr->domain); 9955682Smarkm if(rr->u.data) 10055682Smarkm free(rr->u.data); 10155682Smarkm rr = rr->next; 10255682Smarkm free(tmp); 10355682Smarkm } 10455682Smarkm free (r); 10555682Smarkm} 10655682Smarkm 10755682Smarkmstatic struct dns_reply* 10855682Smarkmparse_reply(unsigned char *data, int len) 10955682Smarkm{ 11055682Smarkm unsigned char *p; 11155682Smarkm char host[128]; 11255682Smarkm int status; 11355682Smarkm 11455682Smarkm struct dns_reply *r; 11555682Smarkm struct resource_record **rr; 11655682Smarkm 11755682Smarkm r = calloc(1, sizeof(*r)); 11855682Smarkm if (r == NULL) 11955682Smarkm return NULL; 12055682Smarkm 12155682Smarkm p = data; 12255682Smarkm#if 0 12355682Smarkm /* doesn't work on Crays */ 12455682Smarkm memcpy(&r->h, p, sizeof(HEADER)); 12555682Smarkm p += sizeof(HEADER); 12655682Smarkm#else 12755682Smarkm memcpy(&r->h, p, 12); /* XXX this will probably be mostly garbage */ 12855682Smarkm p += 12; 12955682Smarkm#endif 13055682Smarkm status = dn_expand(data, data + len, p, host, sizeof(host)); 13155682Smarkm if(status < 0){ 13255682Smarkm dns_free_data(r); 13355682Smarkm return NULL; 13455682Smarkm } 13555682Smarkm r->q.domain = strdup(host); 13655682Smarkm if(r->q.domain == NULL) { 13755682Smarkm dns_free_data(r); 13855682Smarkm return NULL; 13955682Smarkm } 14055682Smarkm p += status; 14155682Smarkm r->q.type = (p[0] << 8 | p[1]); 14255682Smarkm p += 2; 14355682Smarkm r->q.class = (p[0] << 8 | p[1]); 14455682Smarkm p += 2; 14555682Smarkm rr = &r->head; 14655682Smarkm while(p < data + len){ 14755682Smarkm int type, class, ttl, size; 14855682Smarkm status = dn_expand(data, data + len, p, host, sizeof(host)); 14955682Smarkm if(status < 0){ 15055682Smarkm dns_free_data(r); 15155682Smarkm return NULL; 15255682Smarkm } 15355682Smarkm p += status; 15455682Smarkm type = (p[0] << 8) | p[1]; 15555682Smarkm p += 2; 15655682Smarkm class = (p[0] << 8) | p[1]; 15755682Smarkm p += 2; 15855682Smarkm ttl = (p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3]; 15955682Smarkm p += 4; 16055682Smarkm size = (p[0] << 8) | p[1]; 16155682Smarkm p += 2; 16255682Smarkm *rr = (struct resource_record*)calloc(1, 16355682Smarkm sizeof(struct resource_record)); 16455682Smarkm if(*rr == NULL) { 16555682Smarkm dns_free_data(r); 16655682Smarkm return NULL; 16755682Smarkm } 16855682Smarkm (*rr)->domain = strdup(host); 16955682Smarkm if((*rr)->domain == NULL) { 17055682Smarkm dns_free_data(r); 17155682Smarkm return NULL; 17255682Smarkm } 17355682Smarkm (*rr)->type = type; 17455682Smarkm (*rr)->class = class; 17555682Smarkm (*rr)->ttl = ttl; 17655682Smarkm (*rr)->size = size; 17755682Smarkm switch(type){ 17855682Smarkm case T_NS: 17955682Smarkm case T_CNAME: 18055682Smarkm case T_PTR: 18155682Smarkm status = dn_expand(data, data + len, p, host, sizeof(host)); 18255682Smarkm if(status < 0){ 18355682Smarkm dns_free_data(r); 18455682Smarkm return NULL; 18555682Smarkm } 18655682Smarkm (*rr)->u.txt = strdup(host); 18755682Smarkm if((*rr)->u.txt == NULL) { 18855682Smarkm dns_free_data(r); 18955682Smarkm return NULL; 19055682Smarkm } 19155682Smarkm break; 19255682Smarkm case T_MX: 19355682Smarkm case T_AFSDB:{ 19455682Smarkm status = dn_expand(data, data + len, p + 2, host, sizeof(host)); 19555682Smarkm if(status < 0){ 19655682Smarkm dns_free_data(r); 19755682Smarkm return NULL; 19855682Smarkm } 19955682Smarkm (*rr)->u.mx = (struct mx_record*)malloc(sizeof(struct mx_record) + 20055682Smarkm strlen(host)); 20155682Smarkm if((*rr)->u.mx == NULL) { 20255682Smarkm dns_free_data(r); 20355682Smarkm return NULL; 20455682Smarkm } 20555682Smarkm (*rr)->u.mx->preference = (p[0] << 8) | p[1]; 20655682Smarkm strcpy((*rr)->u.mx->domain, host); 20755682Smarkm break; 20855682Smarkm } 20955682Smarkm case T_SRV:{ 21055682Smarkm status = dn_expand(data, data + len, p + 6, host, sizeof(host)); 21155682Smarkm if(status < 0){ 21255682Smarkm dns_free_data(r); 21355682Smarkm return NULL; 21455682Smarkm } 21555682Smarkm (*rr)->u.srv = 21655682Smarkm (struct srv_record*)malloc(sizeof(struct srv_record) + 21755682Smarkm strlen(host)); 21855682Smarkm if((*rr)->u.srv == NULL) { 21955682Smarkm dns_free_data(r); 22055682Smarkm return NULL; 22155682Smarkm } 22255682Smarkm (*rr)->u.srv->priority = (p[0] << 8) | p[1]; 22355682Smarkm (*rr)->u.srv->weight = (p[2] << 8) | p[3]; 22455682Smarkm (*rr)->u.srv->port = (p[4] << 8) | p[5]; 22555682Smarkm strcpy((*rr)->u.srv->target, host); 22655682Smarkm break; 22755682Smarkm } 22855682Smarkm case T_TXT:{ 22955682Smarkm (*rr)->u.txt = (char*)malloc(size + 1); 23055682Smarkm if((*rr)->u.txt == NULL) { 23155682Smarkm dns_free_data(r); 23255682Smarkm return NULL; 23355682Smarkm } 23455682Smarkm strncpy((*rr)->u.txt, (char*)p + 1, *p); 23555682Smarkm (*rr)->u.txt[*p] = 0; 23655682Smarkm break; 23755682Smarkm } 23855682Smarkm 23955682Smarkm default: 24055682Smarkm (*rr)->u.data = (unsigned char*)malloc(size); 24155682Smarkm if(size != 0 && (*rr)->u.data == NULL) { 24255682Smarkm dns_free_data(r); 24355682Smarkm return NULL; 24455682Smarkm } 24555682Smarkm memcpy((*rr)->u.data, p, size); 24655682Smarkm } 24755682Smarkm p += size; 24855682Smarkm rr = &(*rr)->next; 24955682Smarkm } 25055682Smarkm *rr = NULL; 25155682Smarkm return r; 25255682Smarkm} 25355682Smarkm 25455682Smarkmstatic struct dns_reply * 25555682Smarkmdns_lookup_int(const char *domain, int rr_class, int rr_type) 25655682Smarkm{ 25755682Smarkm unsigned char reply[1024]; 25855682Smarkm int len; 25955682Smarkm struct dns_reply *r = NULL; 26055682Smarkm u_long old_options = 0; 26155682Smarkm 26255682Smarkm if (_resolve_debug) { 26355682Smarkm old_options = _res.options; 26455682Smarkm _res.options |= RES_DEBUG; 26555682Smarkm fprintf(stderr, "dns_lookup(%s, %d, %s)\n", domain, 26655682Smarkm rr_class, type_to_string(rr_type)); 26755682Smarkm } 26855682Smarkm len = res_search(domain, rr_class, rr_type, reply, sizeof(reply)); 26955682Smarkm if (_resolve_debug) { 27055682Smarkm _res.options = old_options; 27155682Smarkm fprintf(stderr, "dns_lookup(%s, %d, %s) --> %d\n", 27255682Smarkm domain, rr_class, type_to_string(rr_type), len); 27355682Smarkm } 27455682Smarkm if (len >= 0) 27555682Smarkm r = parse_reply(reply, len); 27655682Smarkm return r; 27755682Smarkm} 27855682Smarkm 27955682Smarkmstruct dns_reply * 28055682Smarkmdns_lookup(const char *domain, const char *type_name) 28155682Smarkm{ 28255682Smarkm int type; 28355682Smarkm 28455682Smarkm type = string_to_type(type_name); 28555682Smarkm if(type == -1) { 28655682Smarkm if(_resolve_debug) 28755682Smarkm fprintf(stderr, "dns_lookup: unknown resource type: `%s'\n", 28855682Smarkm type_name); 28955682Smarkm return NULL; 29055682Smarkm } 29155682Smarkm return dns_lookup_int(domain, C_IN, type); 29255682Smarkm} 29355682Smarkm 29455682Smarkm#else /* NOT defined(HAVE_RES_SEARCH) && defined(HAVE_DN_EXPAND) */ 29555682Smarkm 29655682Smarkmstruct dns_reply * 29755682Smarkmdns_lookup(const char *domain, const char *type_name) 29855682Smarkm{ 29955682Smarkm return NULL; 30055682Smarkm} 30155682Smarkm 30255682Smarkmvoid 30355682Smarkmdns_free_data(struct dns_reply *r) 30455682Smarkm{ 30555682Smarkm} 30655682Smarkm 30755682Smarkm#endif 30855682Smarkm 30955682Smarkm#ifdef TEST 31055682Smarkmint 31155682Smarkmmain(int argc, char **argv) 31255682Smarkm{ 31355682Smarkm struct dns_reply *r; 31455682Smarkm struct resource_record *rr; 31555682Smarkm r = dns_lookup(argv[1], argv[2]); 31655682Smarkm if(r == NULL){ 31755682Smarkm printf("No reply.\n"); 31855682Smarkm return 1; 31955682Smarkm } 32055682Smarkm for(rr = r->head; rr;rr=rr->next){ 32155682Smarkm printf("%s %s %d ", rr->domain, type_to_string(rr->type), rr->ttl); 32255682Smarkm switch(rr->type){ 32355682Smarkm case T_NS: 32455682Smarkm printf("%s\n", (char*)rr->u.data); 32555682Smarkm break; 32655682Smarkm case T_A: 32755682Smarkm printf("%d.%d.%d.%d\n", 32855682Smarkm ((unsigned char*)rr->u.data)[0], 32955682Smarkm ((unsigned char*)rr->u.data)[1], 33055682Smarkm ((unsigned char*)rr->u.data)[2], 33155682Smarkm ((unsigned char*)rr->u.data)[3]); 33255682Smarkm break; 33355682Smarkm case T_MX: 33455682Smarkm case T_AFSDB:{ 33555682Smarkm struct mx_record *mx = (struct mx_record*)rr->u.data; 33655682Smarkm printf("%d %s\n", mx->preference, mx->domain); 33755682Smarkm break; 33855682Smarkm } 33955682Smarkm case T_SRV:{ 34055682Smarkm struct srv_record *srv = (struct srv_record*)rr->u.data; 34155682Smarkm printf("%d %d %d %s\n", srv->priority, srv->weight, 34255682Smarkm srv->port, srv->target); 34355682Smarkm break; 34455682Smarkm } 34555682Smarkm default: 34655682Smarkm printf("\n"); 34755682Smarkm break; 34855682Smarkm } 34955682Smarkm } 35055682Smarkm 35155682Smarkm return 0; 35255682Smarkm} 35355682Smarkm#endif 354