git.sur5r.net Git - openldap/blob - libraries/libldap/dnssrv.c

   1 /* $OpenLDAP$ */
   2 /*
   3  * Copyright 1998-2000 The OpenLDAP Foundation, All Rights Reserved.
   4  * COPYING RESTRICTIONS APPLY, see COPYRIGHT file
   5  */
   6
   7 /*
   8  * locate LDAP servers using DNS SRV records.
   9  * Location code based on MIT Kerberos KDC location code.
  10  */
  11 #include "portable.h"
  12
  13 #include <stdio.h>
  14
  15 #include <ac/stdlib.h>
  16
  17 #include <ac/param.h>
  18 #include <ac/socket.h>
  19 #include <ac/string.h>
  20 #include <ac/time.h>
  21
  22 #include "ldap-int.h"
  23
  24 #ifdef HAVE_ARPA_NAMESER_H
  25 #include <arpa/nameser.h>
  26 #endif
  27 #ifdef HAVE_RESOLV_H
  28 #include <resolv.h>
  29 #endif
  30
  31 /* Sometimes this is not defined. */
  32 #ifndef T_SRV
  33 #define T_SRV            33
  34 #endif                          /* T_SRV */
  35
  36 int ldap_dn2domain(
  37         LDAP_CONST char *dn_in,
  38         char **domainp)
  39 {
  40         int i;
  41         char *domain = NULL;
  42         char **dn;
  43
  44         if( dn_in == NULL || domainp == NULL ) {
  45                 return -1;
  46         }
  47
  48         dn = ldap_explode_dn( dn_in, 0 );
  49
  50         if( dn == NULL ) {
  51                 return -2;
  52         }
  53
  54         for( i=0; dn[i] != NULL; i++ ) {
  55                 char ** rdn = ldap_explode_rdn( dn[i], 0 );
  56
  57                 if( rdn == NULL || *rdn == NULL ) {
  58                         LDAP_FREE( rdn );
  59                         LDAP_FREE( domain );
  60                         LDAP_VFREE( dn );
  61                         return -3;
  62                 }
  63
  64 #define LDAP_DC "dc="
  65 #define LDAP_DCOID "0.9.2342.19200300.100.1.25="
  66
  67                 if( rdn[1] == NULL ) {
  68                         char *dc;
  69                         /* single RDN */
  70
  71                         if( strncasecmp( rdn[0],
  72                                 LDAP_DC, sizeof(LDAP_DC)-1 ) == 0 )
  73                         {
  74                                 dc = &rdn[0][sizeof(LDAP_DC)-1];
  75
  76                         } else if( strncmp( rdn[0],
  77                                 LDAP_DCOID, sizeof(LDAP_DCOID)-1 ) == 0 )
  78                         {
  79                                 dc = &rdn[0][sizeof(LDAP_DCOID)-1];
  80
  81                         } else {
  82                                 dc = NULL;
  83                         }
  84
  85                         if( dc != NULL ) {
  86                                 char *ndomain;
  87
  88                                 if( *dc == '\0' ) {
  89                                         /* dc value is empty! */
  90                                         LDAP_FREE( rdn );
  91                                         LDAP_FREE( domain );
  92                                         LDAP_VFREE( dn );
  93                                         LDAP_VFREE( rdn );
  94                                         return -4;
  95                                 }
  96
  97                                 ndomain = LDAP_REALLOC( domain,
  98                                         ( domain == NULL ? 0 : strlen(domain) )
  99                                         + strlen(dc) + sizeof(".") );
 100
 101                                 if( ndomain == NULL ) {
 102                                         LDAP_FREE( rdn );
 103                                         LDAP_FREE( domain );
 104                                         LDAP_VFREE( dn );
 105                                         LDAP_VFREE( rdn );
 106                                         return -5;
 107                                 }
 108
 109                                 strcat( ndomain, dc );
 110                                 strcat( ndomain, "." );
 111
 112                                 domain = ndomain;
 113                                 continue;
 114                         }
 115                 }
 116
 117                 LDAP_VFREE( rdn );
 118                 LDAP_FREE( domain );
 119                 domain = NULL;
 120         }
 121
 122         *domainp = domain;
 123         return 0;
 124 }
 125
 126 int ldap_domain2dn(
 127         LDAP_CONST char *domain_in,
 128         char **dnp)
 129 {
 130     char *domain, *s, *tok_r, *dn;
 131     size_t loc;
 132
 133     if (domain_in == NULL || dnp == NULL) {
 134         return LDAP_NO_MEMORY;
 135     }
 136     domain = LDAP_STRDUP(domain_in);
 137     if (domain == NULL) {
 138         return LDAP_NO_MEMORY;
 139     }
 140     dn = NULL;
 141     loc = 0;
 142
 143     for (s = ldap_pvt_strtok(domain, ".", &tok_r);
 144          s != NULL;
 145          s = ldap_pvt_strtok(NULL, ".", &tok_r)) {
 146         size_t len = strlen(s);
 147
 148         dn = (char *) LDAP_REALLOC(dn, loc + sizeof(",dc=") + len );
 149         if (dn == NULL) {
 150             LDAP_FREE(domain);
 151             return LDAP_NO_MEMORY;
 152         }
 153         if (loc > 0) {
 154             /* not first time. */
 155             strcpy(dn + loc, ",");
 156             loc++;
 157         }
 158         strcpy(dn + loc, "dc=");
 159         loc += sizeof("dc=")-1;
 160
 161         strcpy(dn + loc, s);
 162         loc += len;
 163     }
 164
 165     LDAP_FREE(domain);
 166
 167     *dnp = dn;
 168
 169     return LDAP_SUCCESS;
 170 }
 171
 172 /*
 173  * Lookup and return LDAP servers for domain (using the DNS
 174  * SRV record _ldap._tcp.domain).
 175  */
 176 int ldap_domain2hostlist(
 177         LDAP_CONST char *domain,
 178         char **list )
 179 {
 180 #ifdef HAVE_RES_SEARCH
 181     char *request;
 182     char *dn;
 183     char *hostlist = NULL;
 184     int rc, len, cur = 0;
 185     unsigned char reply[1024];
 186
 187         if( domain == NULL || *domain == '\0' ) {
 188                 return LDAP_PARAM_ERROR;
 189         }
 190
 191         if( list == NULL ) {
 192                 return LDAP_PARAM_ERROR;
 193         }
 194
 195     request = LDAP_MALLOC(strlen(domain) + sizeof("_ldap._tcp."));
 196     if (request == NULL) {
 197         rc = LDAP_NO_MEMORY;
 198         goto out;
 199     }
 200     sprintf(request, "_ldap._tcp.%s", domain);
 201
 202 #ifdef LDAP_R_COMPILE
 203     ldap_pvt_thread_mutex_lock(&ldap_int_resolv_mutex);
 204 #endif
 205
 206     len = res_search(request, C_IN, T_SRV, reply, sizeof(reply));
 207     if (len >= 0) {
 208         unsigned char *p;
 209         char host[1024];
 210         int status;
 211         u_short port;
 212         /* int priority, weight; */
 213
 214         /* Parse out query */
 215         p = reply;
 216         p += sizeof(HEADER);
 217         status = dn_expand(reply, reply + len, p, host, sizeof(host));
 218         if (status < 0) {
 219             goto out;
 220         }
 221         p += status;
 222         p += 4;
 223
 224         while (p < reply + len) {
 225             int type, class, ttl, size;
 226             status = dn_expand(reply, reply + len, p, host, sizeof(host));
 227             if (status < 0) {
 228                 goto out;
 229             }
 230             p += status;
 231             type = (p[0] << 8) | p[1];
 232             p += 2;
 233             class = (p[0] << 8) | p[1];
 234             p += 2;
 235             ttl = (p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3];
 236             p += 4;
 237             size = (p[0] << 8) | p[1];
 238             p += 2;
 239             if (type == T_SRV) {
 240                 int buflen;
 241                 status = dn_expand(reply, reply + len, p + 6, host, sizeof(host));
 242                 if (status < 0) {
 243                     goto out;
 244                 }
 245                 /* ignore priority and weight for now */
 246                 /* priority = (p[0] << 8) | p[1]; */
 247                 /* weight = (p[2] << 8) | p[3]; */
 248                 port = (p[4] << 8) | p[5];
 249
 250                 buflen = strlen(host) + sizeof(":65355");
 251                 hostlist = (char *) LDAP_REALLOC(hostlist, cur + buflen);
 252                 if (hostlist == NULL) {
 253                     rc = LDAP_NO_MEMORY;
 254                     goto out;
 255                 }
 256                 if (cur > 0) {
 257                     /* not first time around */
 258                     hostlist[cur++] = ' ';
 259                 }
 260                 cur += sprintf(&hostlist[cur], "%s:%hd", host, port);
 261             }
 262             p += size;
 263         }
 264     }
 265     if (hostlist == NULL) {
 266         /* No LDAP servers found in DNS. */
 267         rc = LDAP_UNAVAILABLE;
 268         goto out;
 269     }
 270
 271     rc = LDAP_SUCCESS;
 272         *list = hostlist;
 273
 274   out:
 275 #ifdef LDAP_R_COMPILE
 276     ldap_pvt_thread_mutex_unlock(&ldap_int_resolv_mutex);
 277 #endif
 278
 279     if (request != NULL) {
 280         LDAP_FREE(request);
 281     }
 282     if (rc != LDAP_SUCCESS && hostlist != NULL) {
 283         LDAP_FREE(hostlist);
 284     }
 285     return rc;
 286 #else
 287     return LDAP_NOT_SUPPORTED;
 288 #endif                          /* HAVE_RES_SEARCH */
 289 }