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 "lib/tsocket/tsocket.h"
  31 #include "libcli/composite/composite.h"
  32
  33 struct finddcs_cldap_state {
  34         struct tevent_context *ev;
  35         struct tevent_req *req;
  36         const char *domain_name;
  37         struct dom_sid *domain_sid;
  38         const char *srv_name;
  39         const char **srv_addresses;
  40         uint32_t minimum_dc_flags;
  41         uint32_t srv_address_index;
  42         struct cldap_socket *cldap;
  43         struct cldap_netlogon *netlogon;
  44 };
  45
  46 static void finddcs_cldap_srv_resolved(struct composite_context *ctx);
  47 static void finddcs_cldap_netlogon_replied(struct tevent_req *req);
  48 static bool finddcs_cldap_srv_lookup(struct finddcs_cldap_state *state,
  49                                      struct finddcs *io,
  50                                      struct resolve_context *resolve_ctx,
  51                                      struct tevent_context *event_ctx);
  52 static bool finddcs_cldap_nbt_lookup(struct finddcs_cldap_state *state,
  53                                      struct finddcs *io,
  54                                      struct resolve_context *resolve_ctx,
  55                                      struct tevent_context *event_ctx);
  56 static void finddcs_cldap_name_resolved(struct composite_context *ctx);
  57 static void finddcs_cldap_next_server(struct finddcs_cldap_state *state);
  58 static bool finddcs_cldap_ipaddress(struct finddcs_cldap_state *state, struct finddcs *io);
  59
  60
  61 /*
  62  * find a list of DCs via DNS/CLDAP
  63  *
  64  */
  65 struct tevent_req *finddcs_cldap_send(TALLOC_CTX *mem_ctx,
  66                                       struct finddcs *io,
  67                                       struct resolve_context *resolve_ctx,
  68                                       struct tevent_context *event_ctx)
  69 {
  70         struct finddcs_cldap_state *state;
  71         struct tevent_req *req;
  72
  73         req = tevent_req_create(mem_ctx, &state, struct finddcs_cldap_state);
  74         if (req == NULL) {
  75                 return NULL;
  76         }
  77
  78         state->req = req;
  79         state->ev = event_ctx;
  80         state->minimum_dc_flags = io->in.minimum_dc_flags;
  81         state->domain_name = talloc_strdup(state, io->in.domain_name);
  82         if (tevent_req_nomem(state->domain_name, req)) {
  83                 return tevent_req_post(req, event_ctx);
  84         }
  85
  86         if (io->in.domain_sid) {
  87                 state->domain_sid = dom_sid_dup(state, io->in.domain_sid);
  88                 if (tevent_req_nomem(state->domain_sid, req)) {
  89                         return tevent_req_post(req, event_ctx);
  90                 }
  91         } else {
  92                 state->domain_sid = NULL;
  93         }
  94
  95         if (io->in.server_address) {
  96                 DEBUG(4,("finddcs: searching for a DC by IP %s\n", io->in.server_address));
  97                 if (!finddcs_cldap_ipaddress(state, io)) {
  98                         return tevent_req_post(req, event_ctx);
  99                 }
 100         } else if (strchr(state->domain_name, '.')) {
 101                 /* looks like a DNS name */
 102                 DEBUG(4,("finddcs: searching for a DC by DNS domain %s\n", state->domain_name));
 103                 if (!finddcs_cldap_srv_lookup(state, io, resolve_ctx, event_ctx)) {
 104                         return tevent_req_post(req, event_ctx);
 105                 }
 106         } else {
 107                 DEBUG(4,("finddcs: searching for a DC by NBT lookup %s\n", state->domain_name));
 108                 if (!finddcs_cldap_nbt_lookup(state, io, resolve_ctx, event_ctx)) {
 109                         return tevent_req_post(req, event_ctx);
 110                 }
 111         }
 112
 113         return req;
 114 }
 115
 116
 117 /*
 118   we've been told the IP of the server, bypass name
 119   resolution and go straight to CLDAP
 120 */
 121 static bool finddcs_cldap_ipaddress(struct finddcs_cldap_state *state, struct finddcs *io)
 122 {
 123         NTSTATUS status;
 124
 125         state->srv_addresses = talloc_array(state, const char *, 2);
 126         if (tevent_req_nomem(state->srv_addresses, state->req)) {
 127                 return false;
 128         }
 129         state->srv_addresses[0] = talloc_strdup(state->srv_addresses, io->in.server_address);
 130         if (tevent_req_nomem(state->srv_addresses[0], state->req)) {
 131                 return false;
 132         }
 133         state->srv_addresses[1] = NULL;
 134         state->srv_address_index = 0;
 135
 136         finddcs_cldap_next_server(state);
 137         return tevent_req_is_nterror(state->req, &status);
 138 }
 139
 140 /*
 141   start a SRV DNS lookup
 142  */
 143 static bool finddcs_cldap_srv_lookup(struct finddcs_cldap_state *state,
 144                                      struct finddcs *io,
 145                                      struct resolve_context *resolve_ctx,
 146                                      struct tevent_context *event_ctx)
 147 {
 148         struct composite_context *creq;
 149         struct nbt_name name;
 150
 151         if (io->in.site_name) {
 152                 state->srv_name = talloc_asprintf(state, "_ldap._tcp.%s._sites.%s",
 153                                            io->in.site_name, io->in.domain_name);
 154         } else {
 155                 state->srv_name = talloc_asprintf(state, "_ldap._tcp.%s", io->in.domain_name);
 156         }
 157
 158         DEBUG(4,("finddcs: looking for SRV records for %s\n", state->srv_name));
 159
 160         make_nbt_name(&name, state->srv_name, 0);
 161
 162         creq = resolve_name_ex_send(resolve_ctx, state,
 163                                     RESOLVE_NAME_FLAG_FORCE_DNS | RESOLVE_NAME_FLAG_DNS_SRV,
 164                                     0, &name, event_ctx);
 165         if (tevent_req_nomem(creq, state->req)) {
 166                 return false;
 167         }
 168         creq->async.fn = finddcs_cldap_srv_resolved;
 169         creq->async.private_data = state;
 170
 171         return true;
 172 }
 173
 174 /*
 175   start a NBT name lookup for domain<1C>
 176  */
 177 static bool finddcs_cldap_nbt_lookup(struct finddcs_cldap_state *state,
 178                                      struct finddcs *io,
 179                                      struct resolve_context *resolve_ctx,
 180                                      struct tevent_context *event_ctx)
 181 {
 182         struct composite_context *creq;
 183         struct nbt_name name;
 184
 185         make_nbt_name(&name, state->domain_name, NBT_NAME_LOGON);
 186         creq = resolve_name_send(resolve_ctx, state, &name, event_ctx);
 187         if (tevent_req_nomem(creq, state->req)) {
 188                 return false;
 189         }
 190         creq->async.fn = finddcs_cldap_name_resolved;
 191         creq->async.private_data = state;
 192         return true;
 193 }
 194
 195 /*
 196   fire off a CLDAP query to the next server
 197  */
 198 static void finddcs_cldap_next_server(struct finddcs_cldap_state *state)
 199 {
 200         struct tevent_req *subreq;
 201         struct tsocket_address *dest;
 202         int ret;
 203         NTSTATUS status;
 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         /* we should get the port from the SRV response */
 212         ret = tsocket_address_inet_from_strings(state, "ip",
 213                                                 state->srv_addresses[state->srv_address_index],
 214                                                 389,
 215                                                 &dest);
 216         if (tevent_req_error(state->req, ret)) {
 217                 return;
 218         }
 219
 220         status = cldap_socket_init(state, NULL, dest, &state->cldap);
 221         if (tevent_req_nterror(state->req, status)) {
 222                 return;
 223         }
 224
 225         state->netlogon = talloc_zero(state, struct cldap_netlogon);
 226         if (tevent_req_nomem(state->netlogon, state->req)) {
 227                 return;
 228         }
 229
 230         if (strchr(state->domain_name, '.')) {
 231                 state->netlogon->in.realm = state->domain_name;
 232         }
 233         if (state->domain_sid) {
 234                 state->netlogon->in.domain_sid = dom_sid_string(state, state->domain_sid);
 235                 if (tevent_req_nomem(state->netlogon->in.domain_sid, state->req)) {
 236                         return;
 237                 }
 238         }
 239         state->netlogon->in.acct_control = -1;
 240         state->netlogon->in.version =
 241                 NETLOGON_NT_VERSION_5 |
 242                 NETLOGON_NT_VERSION_5EX |
 243                 NETLOGON_NT_VERSION_IP;
 244         state->netlogon->in.map_response = true;
 245
 246         DEBUG(4,("finddcs: performing CLDAP query on %s\n", state->netlogon->in.dest_address));
 247
 248         subreq = cldap_netlogon_send(state, state->ev,
 249                                      state->cldap, state->netlogon);
 250         if (tevent_req_nomem(subreq, state->req)) {
 251                 return;
 252         }
 253
 254         tevent_req_set_callback(subreq, finddcs_cldap_netlogon_replied, state);
 255 }
 256
 257
 258 /*
 259   we have a response from a CLDAP server for a netlogon request
 260  */
 261 static void finddcs_cldap_netlogon_replied(struct tevent_req *subreq)
 262 {
 263         struct finddcs_cldap_state *state;
 264         NTSTATUS status;
 265
 266         state = tevent_req_callback_data(subreq, struct finddcs_cldap_state);
 267
 268         status = cldap_netlogon_recv(subreq, state->netlogon, state->netlogon);
 269         talloc_free(subreq);
 270         if (!NT_STATUS_IS_OK(status)) {
 271                 state->srv_address_index++;
 272                 finddcs_cldap_next_server(state);
 273                 return;
 274         }
 275         if (state->minimum_dc_flags !=
 276             (state->minimum_dc_flags & state->netlogon->out.netlogon.data.nt5_ex.server_type)) {
 277                 /* the server didn't match the minimum requirements */
 278                 DEBUG(4,("finddcs: Skipping DC %s with server_type=0x%08x - required 0x%08x\n",
 279                          state->srv_addresses[state->srv_address_index],
 280                          state->netlogon->out.netlogon.data.nt5_ex.server_type,
 281                          state->minimum_dc_flags));
 282                 state->srv_address_index++;
 283                 finddcs_cldap_next_server(state);
 284                 return;
 285         }
 286
 287         DEBUG(4,("finddcs: Found matching DC %s with server_type=0x%08x\n",
 288                  state->srv_addresses[state->srv_address_index],
 289                  state->netlogon->out.netlogon.data.nt5_ex.server_type));
 290
 291         tevent_req_done(state->req);
 292 }
 293
 294 /*
 295    handle NBT name lookup reply
 296  */
 297 static void finddcs_cldap_name_resolved(struct composite_context *ctx)
 298 {
 299         struct finddcs_cldap_state *state =
 300                 talloc_get_type(ctx->async.private_data, struct finddcs_cldap_state);
 301         const char *address;
 302         NTSTATUS status;
 303
 304         status = resolve_name_recv(ctx, state, &address);
 305         if (tevent_req_nterror(state->req, status)) {
 306                 DEBUG(2,("finddcs: No matching NBT <1c> server found\n"));
 307                 return;
 308         }
 309
 310         DEBUG(4,("finddcs: Found NBT <1c> server at %s\n", address));
 311
 312         state->srv_addresses = talloc_array(state, const char *, 2);
 313         if (tevent_req_nomem(state->srv_addresses, state->req)) {
 314                 return;
 315         }
 316         state->srv_addresses[0] = address;
 317         state->srv_addresses[1] = NULL;
 318
 319         state->srv_address_index = 0;
 320
 321         finddcs_cldap_next_server(state);
 322 }
 323
 324
 325 /*
 326  * Having got a DNS SRV answer, fire off the first CLDAP request
 327  */
 328 static void finddcs_cldap_srv_resolved(struct composite_context *ctx)
 329 {
 330         struct finddcs_cldap_state *state =
 331                 talloc_get_type(ctx->async.private_data, struct finddcs_cldap_state);
 332         NTSTATUS status;
 333         unsigned i;
 334
 335         status = resolve_name_multiple_recv(ctx, state, &state->srv_addresses);
 336         if (tevent_req_nterror(state->req, status)) {
 337                 DEBUG(2,("finddcs: Failed to find SRV record for %s\n", state->srv_name));
 338                 return;
 339         }
 340
 341         for (i=0; state->srv_addresses[i]; i++) {
 342                 DEBUG(4,("finddcs: DNS SRV response %u at '%s'\n", i, state->srv_addresses[i]));
 343         }
 344
 345         state->srv_address_index = 0;
 346
 347         finddcs_cldap_next_server(state);
 348 }
 349
 350
 351 NTSTATUS finddcs_cldap_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx, struct finddcs *io)
 352 {
 353         struct finddcs_cldap_state *state = tevent_req_data(req, struct finddcs_cldap_state);
 354         bool ok;
 355         NTSTATUS status;
 356
 357         ok = tevent_req_poll(req, state->ev);
 358         if (!ok) {
 359                 talloc_free(req);
 360                 return NT_STATUS_INTERNAL_ERROR;
 361         }
 362         status = tevent_req_simple_recv_ntstatus(req);
 363         if (NT_STATUS_IS_OK(status)) {
 364                 talloc_steal(mem_ctx, state->netlogon);
 365                 io->out.netlogon = state->netlogon->out.netlogon;
 366                 io->out.address = talloc_steal(mem_ctx, state->srv_addresses[state->srv_address_index]);
 367         }
 368         tevent_req_received(req);
 369         return status;
 370 }
 371
 372 NTSTATUS finddcs_cldap(TALLOC_CTX *mem_ctx,
 373                        struct finddcs *io,
 374                        struct resolve_context *resolve_ctx,
 375                        struct tevent_context *event_ctx)
 376 {
 377         NTSTATUS status;
 378         struct tevent_req *req = finddcs_cldap_send(mem_ctx,
 379                                                     io,
 380                                                     resolve_ctx,
 381                                                     event_ctx);
 382         status = finddcs_cldap_recv(req, mem_ctx, io);
 383         talloc_free(req);
 384         return status;
 385 }