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

   1 /* $OpenLDAP$ */
   2 /*
   3  * Copyright 1998-1999 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) + 2 );
 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                                 if( domain == NULL ) {
 110                                         ndomain[0] = '\0';
 111                                 } else {
 112                                         strcat( ndomain, "." );
 113                                 }
 114                                 strcat( ndomain, dc );
 115                                 domain = ndomain;
 116                                 continue;
 117                         }
 118                 }
 119
 120                 LDAP_VFREE( rdn );
 121                 LDAP_FREE( domain );
 122                 domain = NULL;
 123         }
 124
 125         *domainp = domain;
 126         return 0;
 127 }
 128
 129 int ldap_domain2dn(
 130         LDAP_CONST char *domain_in,
 131         char **dnp)
 132 {
 133     char *domain, *s, *tok_r, *dn;
 134     size_t loc;
 135
 136     if (domain_in == NULL || dnp == NULL) {
 137         return LDAP_NO_MEMORY;
 138     }
 139     domain = LDAP_STRDUP(domain_in);
 140     if (domain == NULL) {
 141         return LDAP_NO_MEMORY;
 142     }
 143     dn = NULL;
 144     loc = 0;
 145
 146     for (s = ldap_pvt_strtok(domain, ".", &tok_r);
 147          s != NULL;
 148          s = ldap_pvt_strtok(NULL, ".", &tok_r)) {
 149         size_t len = strlen(s);
 150
 151         dn = (char *) LDAP_REALLOC(dn, loc + sizeof(",dc=") + len );
 152         if (dn == NULL) {
 153             LDAP_FREE(domain);
 154             return LDAP_NO_MEMORY;
 155         }
 156         if (loc > 0) {
 157             /* not first time. */
 158             strcpy(dn + loc, ",");
 159             loc++;
 160         }
 161         strcpy(dn + loc, "dc=");
 162         loc += sizeof("dc=")-1;
 163
 164         strcpy(dn + loc, s);
 165         loc += len;
 166     }
 167
 168     LDAP_FREE(domain);
 169
 170     *dnp = dn;
 171
 172     return LDAP_SUCCESS;
 173 }
 174
 175 /*
 176  * Lookup and return LDAP servers for domain (using the DNS
 177  * SRV record _ldap._tcp.domain).
 178  */
 179 int ldap_domain2hostlist(
 180         LDAP_CONST char *domain,
 181         char **list )
 182 {
 183 #ifdef HAVE_RES_SEARCH
 184     char *request;
 185     char *dn;
 186     char *hostlist = NULL;
 187     int rc, len, cur = 0;
 188     unsigned char reply[1024];
 189
 190         if( domain == NULL || *domain == '\0' ) {
 191                 return LDAP_PARAM_ERROR;
 192         }
 193
 194         if( list == NULL ) {
 195                 return LDAP_PARAM_ERROR;
 196         }
 197
 198     request = LDAP_MALLOC(strlen(domain) + sizeof("_ldap._tcp."));
 199     if (request == NULL) {
 200         rc = LDAP_NO_MEMORY;
 201         goto out;
 202     }
 203     sprintf(request, "_ldap._tcp.%s", domain);
 204
 205 #ifdef LDAP_R_COMPILE
 206     ldap_pvt_thread_mutex_lock(&ldap_int_resolv_mutex);
 207 #endif
 208
 209     len = res_search(request, C_IN, T_SRV, reply, sizeof(reply));
 210     if (len >= 0) {
 211         unsigned char *p;
 212         char host[1024];
 213         int status;
 214         u_short port;
 215         /* int priority, weight; */
 216
 217         /* Parse out query */
 218         p = reply;
 219         p += sizeof(HEADER);
 220         status = dn_expand(reply, reply + len, p, host, sizeof(host));
 221         if (status < 0) {
 222             goto out;
 223         }
 224         p += status;
 225         p += 4;
 226
 227         while (p < reply + len) {
 228             int type, class, ttl, size;
 229             status = dn_expand(reply, reply + len, p, host, sizeof(host));
 230             if (status < 0) {
 231                 goto out;
 232             }
 233             p += status;
 234             type = (p[0] << 8) | p[1];
 235             p += 2;
 236             class = (p[0] << 8) | p[1];
 237             p += 2;
 238             ttl = (p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3];
 239             p += 4;
 240             size = (p[0] << 8) | p[1];
 241             p += 2;
 242             if (type == T_SRV) {
 243                 int buflen;
 244                 status = dn_expand(reply, reply + len, p + 6, host, sizeof(host));
 245                 if (status < 0) {
 246                     goto out;
 247                 }
 248                 /* ignore priority and weight for now */
 249                 /* priority = (p[0] << 8) | p[1]; */
 250                 /* weight = (p[2] << 8) | p[3]; */
 251                 port = (p[4] << 8) | p[5];
 252
 253                 buflen = strlen(host) + sizeof(":65355");
 254                 hostlist = (char *) LDAP_REALLOC(hostlist, cur + buflen);
 255                 if (hostlist == NULL) {
 256                     rc = LDAP_NO_MEMORY;
 257                     goto out;
 258                 }
 259                 if (cur > 0) {
 260                     /* not first time around */
 261                     hostlist[cur++] = ' ';
 262                 }
 263                 cur += sprintf(&hostlist[cur], "%s:%hd", host, port);
 264             }
 265             p += size;
 266         }
 267     }
 268     if (hostlist == NULL) {
 269         /* No LDAP servers found in DNS. */
 270         rc = LDAP_UNAVAILABLE;
 271         goto out;
 272     }
 273
 274     rc = LDAP_SUCCESS;
 275         *list = hostlist;
 276
 277   out:
 278 #ifdef LDAP_R_COMPILE
 279     ldap_pvt_thread_mutex_unlock(&ldap_int_resolv_mutex);
 280 #endif
 281
 282     if (request != NULL) {
 283         LDAP_FREE(request);
 284     }
 285     if (rc != LDAP_SUCCESS && hostlist != NULL) {
 286         LDAP_FREE(hostlist);
 287     }
 288     return rc;
 289 #else
 290     return LDAP_NOT_SUPPORTED;
 291 #endif                          /* HAVE_RES_SEARCH */
 292 }