source4/libcli/finddcs_cldap.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    a composite API for finding a DC and its name via CLDAP
   5
   6    Copyright (C) Andrew Tridgell 2010
   7    Copyright (C) Andrew Bartlett 2010
   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 "include/includes.h"
  24 #include <tevent.h>
  25 #include "libcli/resolve/resolve.h"
  26 #include "libcli/cldap/cldap.h"
  27 #include "libcli/finddc.h"
  28 #include "libcli/security/security.h"
  29 #include "lib/util/tevent_ntstatus.h"
  30 #include "libcli/composite/composite.h"
  31
  32 struct finddcs_cldap_state {
  33         struct tevent_context *ev;
  34         struct tevent_req *req;
  35         const char *domain_name;
  36         struct dom_sid *domain_sid;
  37         const char *srv_name;
  38         const char **srv_addresses;
  39         uint32_t minimum_dc_flags;
  40         uint32_t srv_address_index;
  41         struct cldap_socket *cldap;
  42         struct cldap_netlogon *netlogon;
  43 };
  44
  45 static void finddcs_cldap_srv_resolved(struct composite_context *ctx);
  46 static void finddcs_cldap_netlogon_replied(struct tevent_req *req);
  47 static bool finddcs_cldap_srv_lookup(struct finddcs_cldap_state *state,
  48                                      struct finddcs *io,
  49                                      struct resolve_context *resolve_ctx,
  50                                      struct tevent_context *event_ctx);
  51 static bool finddcs_cldap_nbt_lookup(struct finddcs_cldap_state *state,
  52                                      struct finddcs *io,
  53                                      struct resolve_context *resolve_ctx,
  54                                      struct tevent_context *event_ctx);
  55 static void finddcs_cldap_name_resolved(struct composite_context *ctx);
  56 static void finddcs_cldap_next_server(struct finddcs_cldap_state *state);
  57 static bool finddcs_cldap_ipaddress(struct finddcs_cldap_state *state, struct finddcs *io);
  58
  59
  60 /*
  61  * find a list of DCs via DNS/CLDAP
  62  *
  63  */
  64 struct tevent_req *finddcs_cldap_send(TALLOC_CTX *mem_ctx,
  65                                       struct finddcs *io,
  66                                       struct resolve_context *resolve_ctx,
  67                                       struct tevent_context *event_ctx)
  68 {
  69         struct finddcs_cldap_state *state;
  70         struct tevent_req *req;
  71
  72         req = tevent_req_create(mem_ctx, &state, struct finddcs_cldap_state);
  73         if (req == NULL) {
  74                 return NULL;
  75         }
  76
  77         state->req = req;
  78         state->ev = event_ctx;
  79         state->minimum_dc_flags = io->in.minimum_dc_flags;
  80         state->domain_name = talloc_strdup(state, io->in.domain_name);
  81         if (tevent_req_nomem(state->domain_name, req)) {
  82                 return tevent_req_post(req, event_ctx);
  83         }
  84
  85         if (io->in.domain_sid) {
  86                 state->domain_sid = dom_sid_dup(state, io->in.domain_sid);
  87                 if (tevent_req_nomem(state->domain_sid, req)) {
  88                         return tevent_req_post(req, event_ctx);
  89                 }
  90         } else {
  91                 state->domain_sid = NULL;
  92         }
  93
  94         if (io->in.server_address) {
  95                 DEBUG(4,("finddcs: searching for a DC by IP %s\n", io->in.server_address));
  96                 if (!finddcs_cldap_ipaddress(state, io)) {
  97                         return tevent_req_post(req, event_ctx);
  98                 }
  99         } else if (strchr(state->domain_name, '.')) {
 100                 /* looks like a DNS name */
 101                 DEBUG(4,("finddcs: searching for a DC by DNS domain %s\n", state->domain_name));
 102                 if (!finddcs_cldap_srv_lookup(state, io, resolve_ctx, event_ctx)) {
 103                         return tevent_req_post(req, event_ctx);
 104                 }
 105         } else {
 106                 DEBUG(4,("finddcs: searching for a DC by NBT lookup %s\n", state->domain_name));
 107                 if (!finddcs_cldap_nbt_lookup(state, io, resolve_ctx, event_ctx)) {
 108                         return tevent_req_post(req, event_ctx);
 109                 }
 110         }
 111
 112         return req;
 113 }
 114
 115
 116 /*
 117   we've been told the IP of the server, bypass name
 118   resolution and go straight to CLDAP
 119 */
 120 static bool finddcs_cldap_ipaddress(struct finddcs_cldap_state *state, struct finddcs *io)
 121 {
 122         NTSTATUS status;
 123
 124         state->srv_addresses = talloc_array(state, const char *, 2);
 125         if (tevent_req_nomem(state->srv_addresses, state->req)) {
 126                 return false;
 127         }
 128         state->srv_addresses[0] = talloc_strdup(state->srv_addresses, io->in.server_address);
 129         if (tevent_req_nomem(state->srv_addresses[0], state->req)) {
 130                 return false;
 131         }
 132         state->srv_addresses[1] = NULL;
 133         state->srv_address_index = 0;
 134         status = cldap_socket_init(state, state->ev, NULL, NULL, &state->cldap);
 135         if (tevent_req_nterror(state->req, status)) {
 136                 return false;
 137         }
 138
 139         finddcs_cldap_next_server(state);
 140         return tevent_req_is_nterror(state->req, &status);
 141 }
 142
 143 /*
 144   start a SRV DNS lookup
 145  */
 146 static bool finddcs_cldap_srv_lookup(struct finddcs_cldap_state *state,
 147                                      struct finddcs *io,
 148                                      struct resolve_context *resolve_ctx,
 149                                      struct tevent_context *event_ctx)
 150 {
 151         struct composite_context *creq;
 152         struct nbt_name name;
 153
 154         if (io->in.site_name) {
 155                 state->srv_name = talloc_asprintf(state, "_ldap._tcp.%s._sites.%s",
 156                                            io->in.site_name, io->in.domain_name);
 157         } else {
 158                 state->srv_name = talloc_asprintf(state, "_ldap._tcp.%s", io->in.domain_name);
 159         }
 160
 161         DEBUG(4,("finddcs: looking for SRV records for %s\n", state->srv_name));
 162
 163         make_nbt_name(&name, state->srv_name, 0);
 164
 165         creq = resolve_name_ex_send(resolve_ctx, state,
 166                                     RESOLVE_NAME_FLAG_FORCE_DNS | RESOLVE_NAME_FLAG_DNS_SRV,
 167                                     0, &name, event_ctx);
 168         if (tevent_req_nomem(creq, state->req)) {
 169                 return false;
 170         }
 171         creq->async.fn = finddcs_cldap_srv_resolved;
 172         creq->async.private_data = state;
 173
 174         return true;
 175 }
 176
 177 /*
 178   start a NBT name lookup for domain<1C>
 179  */
 180 static bool finddcs_cldap_nbt_lookup(struct finddcs_cldap_state *state,
 181                                      struct finddcs *io,
 182                                      struct resolve_context *resolve_ctx,
 183                                      struct tevent_context *event_ctx)
 184 {
 185         struct composite_context *creq;
 186         struct nbt_name name;
 187
 188         make_nbt_name(&name, state->domain_name, NBT_NAME_LOGON);
 189         creq = resolve_name_send(resolve_ctx, state, &name, event_ctx);
 190         if (tevent_req_nomem(creq, state->req)) {
 191                 return false;
 192         }
 193         creq->async.fn = finddcs_cldap_name_resolved;
 194         creq->async.private_data = state;
 195         return true;
 196 }
 197
 198 /*
 199   fire off a CLDAP query to the next server
 200  */
 201 static void finddcs_cldap_next_server(struct finddcs_cldap_state *state)
 202 {
 203         struct tevent_req *subreq;
 204
 205         if (state->srv_addresses[state->srv_address_index] == NULL) {
 206                 tevent_req_nterror(state->req, NT_STATUS_OBJECT_NAME_NOT_FOUND);
 207                 DEBUG(2,("finddcs: No matching CLDAP server found\n"));
 208                 return;
 209         }
 210
 211         state->netlogon = talloc_zero(state, struct cldap_netlogon);
 212         if (tevent_req_nomem(state->netlogon, state->req)) {
 213                 return;
 214         }
 215
 216         state->netlogon->in.dest_address = state->srv_addresses[state->srv_address_index];
 217         /* we should get the port from the SRV response */
 218         state->netlogon->in.dest_port = 389;
 219         if (strchr(state->domain_name, '.')) {
 220                 state->netlogon->in.realm = state->domain_name;
 221         }
 222         if (state->domain_sid) {
 223                 state->netlogon->in.domain_sid = dom_sid_string(state, state->domain_sid);
 224                 if (tevent_req_nomem(state->netlogon->in.domain_sid, state->req)) {
 225                         return;
 226                 }
 227         }
 228         state->netlogon->in.acct_control = -1;
 229         state->netlogon->in.version =
 230                 NETLOGON_NT_VERSION_5 |
 231                 NETLOGON_NT_VERSION_5EX |
 232                 NETLOGON_NT_VERSION_IP;
 233         state->netlogon->in.map_response = true;
 234
 235         DEBUG(4,("finddcs: performing CLDAP query on %s\n", state->netlogon->in.dest_address));
 236
 237         subreq = cldap_netlogon_send(state, state->cldap, state->netlogon);
 238         if (tevent_req_nomem(subreq, state->req)) {
 239                 return;
 240         }
 241
 242         tevent_req_set_callback(subreq, finddcs_cldap_netlogon_replied, state);
 243 }
 244
 245
 246 /*
 247   we have a response from a CLDAP server for a netlogon request
 248  */
 249 static void finddcs_cldap_netlogon_replied(struct tevent_req *subreq)
 250 {
 251         struct finddcs_cldap_state *state;
 252         NTSTATUS status;
 253
 254         state = tevent_req_callback_data(subreq, struct finddcs_cldap_state);
 255
 256         status = cldap_netlogon_recv(subreq, state->netlogon, state->netlogon);
 257         talloc_free(subreq);
 258         if (!NT_STATUS_IS_OK(status)) {
 259                 state->srv_address_index++;
 260                 finddcs_cldap_next_server(state);
 261                 return;
 262         }
 263         if (state->minimum_dc_flags !=
 264             (state->minimum_dc_flags & state->netlogon->out.netlogon.data.nt5_ex.server_type)) {
 265                 /* the server didn't match the minimum requirements */
 266                 DEBUG(4,("finddcs: Skipping DC %s with server_type=0x%08x - required 0x%08x\n",
 267                          state->srv_addresses[state->srv_address_index],
 268                          state->netlogon->out.netlogon.data.nt5_ex.server_type,
 269                          state->minimum_dc_flags));
 270                 state->srv_address_index++;
 271                 finddcs_cldap_next_server(state);
 272                 return;
 273         }
 274
 275         DEBUG(4,("finddcs: Found matching DC %s with server_type=0x%08x\n",
 276                  state->srv_addresses[state->srv_address_index],
 277                  state->netlogon->out.netlogon.data.nt5_ex.server_type));
 278
 279         tevent_req_done(state->req);
 280 }
 281
 282 /*
 283    handle NBT name lookup reply
 284  */
 285 static void finddcs_cldap_name_resolved(struct composite_context *ctx)
 286 {
 287         struct finddcs_cldap_state *state =
 288                 talloc_get_type(ctx->async.private_data, struct finddcs_cldap_state);
 289         const char *address;
 290         NTSTATUS status;
 291
 292         status = resolve_name_recv(ctx, state, &address);
 293         if (tevent_req_nterror(state->req, status)) {
 294                 DEBUG(2,("finddcs: No matching NBT <1c> server found\n"));
 295                 return;
 296         }
 297
 298         DEBUG(4,("finddcs: Found NBT <1c> server at %s\n", address));
 299
 300         state->srv_addresses = talloc_array(state, const char *, 2);
 301         if (tevent_req_nomem(state->srv_addresses, state->req)) {
 302                 return;
 303         }
 304         state->srv_addresses[0] = address;
 305         state->srv_addresses[1] = NULL;
 306
 307         state->srv_address_index = 0;
 308
 309         status = cldap_socket_init(state, state->ev, NULL, NULL, &state->cldap);
 310         if (tevent_req_nterror(state->req, status)) {
 311                 return;
 312         }
 313
 314         finddcs_cldap_next_server(state);
 315 }
 316
 317
 318 /*
 319  * Having got a DNS SRV answer, fire off the first CLDAP request
 320  */
 321 static void finddcs_cldap_srv_resolved(struct composite_context *ctx)
 322 {
 323         struct finddcs_cldap_state *state =
 324                 talloc_get_type(ctx->async.private_data, struct finddcs_cldap_state);
 325         NTSTATUS status;
 326         unsigned i;
 327
 328         status = resolve_name_multiple_recv(ctx, state, &state->srv_addresses);
 329         if (tevent_req_nterror(state->req, status)) {
 330                 DEBUG(2,("finddcs: Failed to find SRV record for %s\n", state->srv_name));
 331                 return;
 332         }
 333
 334         for (i=0; state->srv_addresses[i]; i++) {
 335                 DEBUG(4,("finddcs: DNS SRV response %u at '%s'\n", i, state->srv_addresses[i]));
 336         }
 337
 338         state->srv_address_index = 0;
 339
 340         status = cldap_socket_init(state, state->ev, NULL, NULL, &state->cldap);
 341         if (tevent_req_nterror(state->req, status)) {
 342                 return;
 343         }
 344
 345         finddcs_cldap_next_server(state);
 346 }
 347
 348
 349 NTSTATUS finddcs_cldap_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx, struct finddcs *io)
 350 {
 351         struct finddcs_cldap_state *state = tevent_req_data(req, struct finddcs_cldap_state);
 352         bool ok;
 353         NTSTATUS status;
 354
 355         ok = tevent_req_poll(req, state->ev);
 356         if (!ok) {
 357                 talloc_free(req);
 358                 return NT_STATUS_INTERNAL_ERROR;
 359         }
 360         status = tevent_req_simple_recv_ntstatus(req);
 361         if (NT_STATUS_IS_OK(status)) {
 362                 talloc_steal(mem_ctx, state->netlogon);
 363                 io->out.netlogon = state->netlogon->out.netlogon;
 364                 io->out.address = talloc_steal(mem_ctx, state->srv_addresses[state->srv_address_index]);
 365         }
 366         tevent_req_received(req);
 367         return status;
 368 }
 369
 370 NTSTATUS finddcs_cldap(TALLOC_CTX *mem_ctx,
 371                        struct finddcs *io,
 372                        struct resolve_context *resolve_ctx,
 373                        struct tevent_context *event_ctx)
 374 {
 375         NTSTATUS status;
 376         struct tevent_req *req = finddcs_cldap_send(mem_ctx,
 377                                                     io,
 378                                                     resolve_ctx,
 379                                                     event_ctx);
 380         status = finddcs_cldap_recv(req, mem_ctx, io);
 381         talloc_free(req);
 382         return status;
 383 }