source3/utils/net_ads_join_dns.c

   1 /*
   2    Samba Unix/Linux SMB client library
   3    net ads dns internal functions
   4    Copyright (C) 2001 Andrew Tridgell (tridge@samba.org)
   5    Copyright (C) 2001 Remus Koos (remuskoos@yahoo.com)
   6    Copyright (C) 2002 Jim McDonough (jmcd@us.ibm.com)
   7    Copyright (C) 2006 Gerald (Jerry) Carter (jerry@samba.org)
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21 */
  22
  23 #include "includes.h"
  24 #include "utils/net.h"
  25 #include "../lib/addns/dnsquery.h"
  26 #include "secrets.h"
  27 #include "krb5_env.h"
  28 #include "utils/net_dns.h"
  29 #include "lib/util/string_wrappers.h"
  30
  31 #ifdef HAVE_ADS
  32
  33 /*******************************************************************
  34  Send a DNS update request
  35 *******************************************************************/
  36
  37 #if defined(HAVE_KRB5)
  38 #include "../lib/addns/dns.h"
  39
  40 void use_in_memory_ccache(void) {
  41         /* Use in-memory credentials cache so we do not interfere with
  42          * existing credentials */
  43         setenv(KRB5_ENV_CCNAME, "MEMORY:net_ads", 1);
  44 }
  45
  46 static NTSTATUS net_update_dns_internal(struct net_context *c,
  47                                         TALLOC_CTX *ctx, ADS_STRUCT *ads,
  48                                         const char *machine_name,
  49                                         const struct sockaddr_storage *addrs,
  50                                         int num_addrs, bool remove_host)
  51 {
  52         struct dns_rr_ns *nameservers = NULL;
  53         size_t ns_count = 0, i;
  54         NTSTATUS status = NT_STATUS_UNSUCCESSFUL;
  55         DNS_ERROR dns_err;
  56         fstring dns_server;
  57         const char *dnsdomain = NULL;
  58         char *root_domain = NULL;
  59         uint32_t ttl = 3600;
  60
  61         if (c->opt_dns_ttl > 0) {
  62                 ttl = MIN(c->opt_dns_ttl, UINT32_MAX);
  63         }
  64
  65         if ( (dnsdomain = strchr_m( machine_name, '.')) == NULL ) {
  66                 d_printf(_("No DNS domain configured for %s. "
  67                            "Unable to perform DNS Update.\n"), machine_name);
  68                 status = NT_STATUS_INVALID_PARAMETER;
  69                 goto done;
  70         }
  71         dnsdomain++;
  72
  73         status = ads_dns_lookup_ns(ctx,
  74                                    dnsdomain,
  75                                    &nameservers,
  76                                    &ns_count);
  77         if ( !NT_STATUS_IS_OK(status) || (ns_count == 0)) {
  78                 /* Child domains often do not have NS records.  Look
  79                    for the NS record for the forest root domain
  80                    (rootDomainNamingContext in therootDSE) */
  81
  82                 const char *rootname_attrs[] =  { "rootDomainNamingContext", NULL };
  83                 LDAPMessage *msg = NULL;
  84                 char *root_dn;
  85                 ADS_STATUS ads_status;
  86
  87                 if ( !ads->ldap.ld ) {
  88                         ads_status = ads_connect( ads );
  89                         if ( !ADS_ERR_OK(ads_status) ) {
  90                                 DEBUG(0,("net_update_dns_internal: Failed to connect to our DC!\n"));
  91                                 goto done;
  92                         }
  93                 }
  94
  95                 ads_status = ads_do_search(ads, "", LDAP_SCOPE_BASE,
  96                                        "(objectclass=*)", rootname_attrs, &msg);
  97                 if (!ADS_ERR_OK(ads_status)) {
  98                         goto done;
  99                 }
 100
 101                 root_dn = ads_pull_string(ads, ctx, msg,  "rootDomainNamingContext");
 102                 if ( !root_dn ) {
 103                         ads_msgfree( ads, msg );
 104                         goto done;
 105                 }
 106
 107                 root_domain = ads_build_domain( root_dn );
 108
 109                 /* cleanup */
 110                 ads_msgfree( ads, msg );
 111
 112                 /* try again for NS servers */
 113
 114                 status = ads_dns_lookup_ns(ctx,
 115                                            root_domain,
 116                                            &nameservers,
 117                                            &ns_count);
 118
 119                 if ( !NT_STATUS_IS_OK(status) || (ns_count == 0)) {
 120                         DEBUG(3,("net_update_dns_internal: Failed to find name server for the %s "
 121                          "realm\n", ads->config.realm));
 122                         if (ns_count == 0) {
 123                                 status = NT_STATUS_UNSUCCESSFUL;
 124                         }
 125                         goto done;
 126                 }
 127
 128                 dnsdomain = root_domain;
 129
 130         }
 131
 132         for (i=0; i < ns_count; i++) {
 133
 134                 uint32_t flags = DNS_UPDATE_SIGNED |
 135                                  DNS_UPDATE_UNSIGNED |
 136                                  DNS_UPDATE_UNSIGNED_SUFFICIENT |
 137                                  DNS_UPDATE_PROBE |
 138                                  DNS_UPDATE_PROBE_SUFFICIENT;
 139
 140                 if (c->opt_force) {
 141                         flags &= ~DNS_UPDATE_PROBE_SUFFICIENT;
 142                         flags &= ~DNS_UPDATE_UNSIGNED_SUFFICIENT;
 143                 }
 144
 145                 /*
 146                  *  Do not return after PROBE completion if this function
 147                  *  is called for DNS removal.
 148                  */
 149                 if (remove_host) {
 150                         flags &= ~DNS_UPDATE_PROBE_SUFFICIENT;
 151                 }
 152
 153                 status = NT_STATUS_UNSUCCESSFUL;
 154
 155                 /* Now perform the dns update - we'll try non-secure and if we fail,
 156                    we'll follow it up with a secure update */
 157
 158                 fstrcpy( dns_server, nameservers[i].hostname );
 159
 160                 dns_err = DoDNSUpdate(dns_server,
 161                                       dnsdomain,
 162                                       machine_name,
 163                                       addrs,
 164                                       num_addrs,
 165                                       flags,
 166                                       ttl,
 167                                       remove_host);
 168                 if (ERR_DNS_IS_OK(dns_err)) {
 169                         status = NT_STATUS_OK;
 170                         goto done;
 171                 }
 172
 173                 if (ERR_DNS_EQUAL(dns_err, ERROR_DNS_INVALID_NAME_SERVER) ||
 174                     ERR_DNS_EQUAL(dns_err, ERROR_DNS_CONNECTION_FAILED) ||
 175                     ERR_DNS_EQUAL(dns_err, ERROR_DNS_SOCKET_ERROR)) {
 176                         DEBUG(1,("retrying DNS update with next nameserver after receiving %s\n",
 177                                 dns_errstr(dns_err)));
 178                         continue;
 179                 }
 180
 181                 d_printf(_("DNS Update for %s failed: %s\n"),
 182                         machine_name, dns_errstr(dns_err));
 183                 status = NT_STATUS_UNSUCCESSFUL;
 184                 goto done;
 185         }
 186
 187 done:
 188
 189         SAFE_FREE( root_domain );
 190
 191         return status;
 192 }
 193
 194 NTSTATUS net_update_dns_ext(struct net_context *c,
 195                             TALLOC_CTX *mem_ctx, ADS_STRUCT *ads,
 196                             const char *hostname,
 197                             struct sockaddr_storage *iplist,
 198                             int num_addrs, bool remove_host)
 199 {
 200         struct sockaddr_storage *iplist_alloc = NULL;
 201         fstring machine_name;
 202         NTSTATUS status;
 203
 204         if (hostname) {
 205                 fstrcpy(machine_name, hostname);
 206         } else {
 207                 name_to_fqdn( machine_name, lp_netbios_name() );
 208         }
 209         if (!strlower_m( machine_name )) {
 210                 return NT_STATUS_INVALID_PARAMETER;
 211         }
 212
 213         /*
 214          * If remove_host is true, then remove all IP addresses associated with
 215          * this hostname from the AD server.
 216          */
 217         if (!remove_host && (num_addrs == 0 || iplist == NULL)) {
 218                 /*
 219                  * Get our ip address
 220                  * (not the 127.0.0.x address but a real ip address)
 221                  */
 222                 num_addrs = get_my_ip_address(&iplist_alloc);
 223                 if ( num_addrs <= 0 ) {
 224                         DEBUG(4, ("net_update_dns_ext: Failed to find my "
 225                                   "non-loopback IP addresses!\n"));
 226                         return NT_STATUS_INVALID_PARAMETER;
 227                 }
 228                 iplist = iplist_alloc;
 229         }
 230
 231         status = net_update_dns_internal(c, mem_ctx, ads, machine_name,
 232                                          iplist, num_addrs, remove_host);
 233
 234         SAFE_FREE(iplist_alloc);
 235         return status;
 236 }
 237
 238 static NTSTATUS net_update_dns(struct net_context *c, TALLOC_CTX *mem_ctx, ADS_STRUCT *ads, const char *hostname)
 239 {
 240         NTSTATUS status;
 241
 242         status = net_update_dns_ext(c, mem_ctx, ads, hostname, NULL, 0, false);
 243         return status;
 244 }
 245 #endif
 246
 247 void net_ads_join_dns_updates(struct net_context *c, TALLOC_CTX *ctx, struct libnet_JoinCtx *r)
 248 {
 249 #if defined(HAVE_KRB5)
 250         ADS_STRUCT *ads_dns = NULL;
 251         int ret;
 252         NTSTATUS status;
 253         char *machine_password = NULL;
 254
 255         /*
 256          * In a clustered environment, don't do dynamic dns updates:
 257          * Registering the set of ip addresses that are assigned to
 258          * the interfaces of the node that performs the join does usually
 259          * not have the desired effect, since the local interfaces do not
 260          * carry the complete set of the cluster's public IP addresses.
 261          * And it can also contain internal addresses that should not
 262          * be visible to the outside at all.
 263          * In order to do dns updates in a clustererd setup, use
 264          * net ads dns register.
 265          */
 266         if (lp_clustering()) {
 267                 d_fprintf(stderr, _("Not doing automatic DNS update in a "
 268                                     "clustered setup.\n"));
 269                 return;
 270         }
 271
 272         if (!r->out.domain_is_ad) {
 273                 return;
 274         }
 275
 276         /*
 277          * We enter this block with user creds.
 278          * kinit with the machine password to do dns update.
 279          */
 280
 281         ads_dns = ads_init(ctx,
 282                            lp_realm(),
 283                            NULL,
 284                            r->in.dc_name,
 285                            ADS_SASL_PLAIN);
 286         if (ads_dns == NULL) {
 287                 d_fprintf(stderr, _("DNS update failed: out of memory!\n"));
 288                 goto done;
 289         }
 290
 291         use_in_memory_ccache();
 292
 293         ads_dns->auth.user_name = talloc_asprintf(ads_dns,
 294                                                   "%s$",
 295                                                   lp_netbios_name());
 296         if (ads_dns->auth.user_name == NULL) {
 297                 d_fprintf(stderr, _("DNS update failed: out of memory\n"));
 298                 goto done;
 299         }
 300
 301         machine_password = secrets_fetch_machine_password(
 302                 r->out.netbios_domain_name, NULL, NULL);
 303         if (machine_password != NULL) {
 304                 ads_dns->auth.password = talloc_strdup(ads_dns,
 305                                                        machine_password);
 306                 SAFE_FREE(machine_password);
 307                 if (ads_dns->auth.password == NULL) {
 308                         d_fprintf(stderr,
 309                                   _("DNS update failed: out of memory\n"));
 310                         goto done;
 311                 }
 312         }
 313
 314         ads_dns->auth.realm = talloc_asprintf_strupper_m(ads_dns, "%s", r->out.dns_domain_name);
 315         if (ads_dns->auth.realm == NULL) {
 316                 d_fprintf(stderr, _("talloc_asprintf_strupper_m %s failed\n"),
 317                                   ads_dns->auth.realm);
 318                 goto done;
 319         }
 320
 321         ret = ads_kinit_password(ads_dns);
 322         if (ret != 0) {
 323                 d_fprintf(stderr,
 324                           _("DNS update failed: kinit failed: %s\n"),
 325                           error_message(ret));
 326                 goto done;
 327         }
 328
 329         status = net_update_dns(c, ctx, ads_dns, NULL);
 330         if (!NT_STATUS_IS_OK(status)) {
 331                 d_fprintf( stderr, _("DNS update failed: %s\n"),
 332                           nt_errstr(status));
 333         }
 334
 335 done:
 336         TALLOC_FREE(ads_dns);
 337 #endif
 338
 339         return;
 340 }
 341
 342 #endif  /* HAVE_ADS */