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 "lib/messaging/messaging.h"
  27 #include "libcli/libcli.h"
  28 #include "libcli/cldap/cldap.h"
  29 #include "libcli/finddc.h"
  30 #include "libcli/security/dom_sid.h"
  31 #include "lib/util/tevent_ntstatus.h"
  32 #include "libcli/composite/composite.h"
  33
  34 struct finddcs_cldap_state {
  35         struct tevent_context *ev;
  36         struct tevent_req *req;
  37         const char *domain_name;
  38         struct dom_sid *domain_sid;
  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
  58
  59 /*
  60  * find a list of DCs via DNS/CLDAP
  61  *
  62  */
  63 struct tevent_req *finddcs_cldap_send(TALLOC_CTX *mem_ctx,
  64                                       struct finddcs *io,
  65                                       struct resolve_context *resolve_ctx,
  66                                       struct tevent_context *event_ctx)
  67 {
  68         struct finddcs_cldap_state *state;
  69         struct tevent_req *req;
  70
  71         req = tevent_req_create(mem_ctx, &state, struct finddcs_cldap_state);
  72         if (req == NULL) {
  73                 return NULL;
  74         }
  75
  76         state->req = req;
  77         state->ev = event_ctx;
  78         state->minimum_dc_flags = io->in.minimum_dc_flags;
  79         state->domain_name = talloc_strdup(state, io->in.domain_name);
  80         if (tevent_req_nomem(state->domain_name, req)) {
  81                 return tevent_req_post(req, event_ctx);
  82         }
  83
  84         if (io->in.domain_sid) {
  85                 state->domain_sid = dom_sid_dup(state, io->in.domain_sid);
  86                 if (tevent_req_nomem(state->domain_sid, req)) {
  87                         return tevent_req_post(req, event_ctx);
  88                 }
  89         } else {
  90                 state->domain_sid = NULL;
  91         }
  92
  93         if (strchr(state->domain_name, '.')) {
  94                 /* looks like a DNS name */
  95                 if (!finddcs_cldap_srv_lookup(state, io, resolve_ctx, event_ctx)) {
  96                         return tevent_req_post(req, event_ctx);
  97                 }
  98         } else {
  99                 if (!finddcs_cldap_nbt_lookup(state, io, resolve_ctx, event_ctx)) {
 100                         return tevent_req_post(req, event_ctx);
 101                 }
 102         }
 103
 104         return req;
 105 }
 106
 107 /*
 108   start a SRV DNS lookup
 109  */
 110 static bool finddcs_cldap_srv_lookup(struct finddcs_cldap_state *state,
 111                                      struct finddcs *io,
 112                                      struct resolve_context *resolve_ctx,
 113                                      struct tevent_context *event_ctx)
 114 {
 115         const char *srv_name;
 116         struct composite_context *creq;
 117         struct nbt_name name;
 118
 119         if (io->in.site_name) {
 120                 srv_name = talloc_asprintf(state, "_ldap._tcp.%s._sites.%s",
 121                                            io->in.site_name, io->in.domain_name);
 122         } else {
 123                 srv_name = talloc_asprintf(state, "_ldap._tcp.%s", io->in.domain_name);
 124         }
 125
 126         make_nbt_name(&name, srv_name, 0);
 127
 128         creq = resolve_name_ex_send(resolve_ctx, state,
 129                                     RESOLVE_NAME_FLAG_FORCE_DNS | RESOLVE_NAME_FLAG_DNS_SRV,
 130                                     0, &name, event_ctx);
 131         if (tevent_req_nomem(creq, state->req)) {
 132                 return false;
 133         }
 134         creq->async.fn = finddcs_cldap_srv_resolved;
 135         creq->async.private_data = state;
 136
 137         return true;
 138 }
 139
 140 /*
 141   start a NBT name lookup for domain<1C>
 142  */
 143 static bool finddcs_cldap_nbt_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         make_nbt_name(&name, state->domain_name, NBT_NAME_LOGON);
 152         creq = resolve_name_send(resolve_ctx, state, &name, event_ctx);
 153         if (tevent_req_nomem(creq, state->req)) {
 154                 return false;
 155         }
 156         creq->async.fn = finddcs_cldap_name_resolved;
 157         creq->async.private_data = state;
 158         return true;
 159 }
 160
 161 /*
 162   fire off a CLDAP query to the next server
 163  */
 164 static void finddcs_cldap_next_server(struct finddcs_cldap_state *state)
 165 {
 166         struct tevent_req *subreq;
 167
 168         if (state->srv_addresses[state->srv_address_index] == NULL) {
 169                 tevent_req_nterror(state->req, NT_STATUS_OBJECT_NAME_NOT_FOUND);
 170                 return;
 171         }
 172
 173         state->netlogon = talloc_zero(state, struct cldap_netlogon);
 174         if (tevent_req_nomem(state->netlogon, state->req)) {
 175                 return;
 176         }
 177
 178         state->netlogon->in.dest_address = state->srv_addresses[state->srv_address_index];
 179         /* we should get the port from the SRV response */
 180         state->netlogon->in.dest_port = 389;
 181         if (strchr(state->domain_name, '.')) {
 182                 state->netlogon->in.realm = state->domain_name;
 183         }
 184         if (state->domain_sid) {
 185                 state->netlogon->in.domain_sid = dom_sid_string(state, state->domain_sid);
 186                 if (tevent_req_nomem(state->netlogon->in.domain_sid, state->req)) {
 187                         return;
 188                 }
 189         }
 190         state->netlogon->in.acct_control = -1;
 191         state->netlogon->in.version =
 192                 NETLOGON_NT_VERSION_5 |
 193                 NETLOGON_NT_VERSION_5EX |
 194                 NETLOGON_NT_VERSION_IP;
 195         state->netlogon->in.map_response = true;
 196
 197         subreq = cldap_netlogon_send(state, state->cldap, state->netlogon);
 198         if (tevent_req_nomem(subreq, state->req)) {
 199                 return;
 200         }
 201
 202         tevent_req_set_callback(subreq, finddcs_cldap_netlogon_replied, state);
 203 }
 204
 205
 206 /*
 207   we have a response from a CLDAP server for a netlogon request
 208  */
 209 static void finddcs_cldap_netlogon_replied(struct tevent_req *subreq)
 210 {
 211         struct finddcs_cldap_state *state;
 212         NTSTATUS status;
 213
 214         state = tevent_req_callback_data(subreq, struct finddcs_cldap_state);
 215
 216         status = cldap_netlogon_recv(subreq, state->netlogon, state->netlogon);
 217         if (!NT_STATUS_IS_OK(status)) {
 218                 state->srv_address_index++;
 219                 finddcs_cldap_next_server(state);
 220                 return;
 221         }
 222         if (state->minimum_dc_flags !=
 223             (state->minimum_dc_flags & state->netlogon->out.netlogon.data.nt5_ex.server_type)) {
 224                 /* the server didn't match the minimum requirements */
 225                 DEBUG(4,(__location__ ": Skipping DC %s with server_type=0x%08x\n",
 226                          state->srv_addresses[state->srv_address_index],
 227                          state->netlogon->out.netlogon.data.nt5_ex.server_type));
 228                 state->srv_address_index++;
 229                 finddcs_cldap_next_server(state);
 230                 return;
 231         }
 232
 233         talloc_free(subreq);
 234         tevent_req_done(state->req);
 235 }
 236
 237 /*
 238    handle NBT name lookup reply
 239  */
 240 static void finddcs_cldap_name_resolved(struct composite_context *ctx)
 241 {
 242         struct finddcs_cldap_state *state =
 243                 talloc_get_type(ctx->async.private_data, struct finddcs_cldap_state);
 244         const char *address;
 245         NTSTATUS status;
 246
 247         status = resolve_name_recv(ctx, state, &address);
 248         if (tevent_req_nterror(state->req, status)) {
 249                 return;
 250         }
 251
 252         state->srv_addresses = talloc_array(state, const char *, 2);
 253         if (tevent_req_nomem(state->srv_addresses, state->req)) {
 254                 return;
 255         }
 256         state->srv_addresses[0] = address;
 257         state->srv_addresses[1] = NULL;
 258
 259         state->srv_address_index = 0;
 260
 261         status = cldap_socket_init(state, state->ev, NULL, NULL, &state->cldap);
 262         if (tevent_req_nterror(state->req, status)) {
 263                 return;
 264         }
 265
 266         finddcs_cldap_next_server(state);
 267 }
 268
 269
 270 /*
 271  * Having got a DNS SRV answer, fire off the first CLDAP request
 272  */
 273 static void finddcs_cldap_srv_resolved(struct composite_context *ctx)
 274 {
 275         struct finddcs_cldap_state *state =
 276                 talloc_get_type(ctx->async.private_data, struct finddcs_cldap_state);
 277         NTSTATUS status;
 278
 279         status = resolve_name_multiple_recv(ctx, state, &state->srv_addresses);
 280         if (tevent_req_nterror(state->req, status)) {
 281                 return;
 282         }
 283
 284         state->srv_address_index = 0;
 285
 286         status = cldap_socket_init(state, state->ev, NULL, NULL, &state->cldap);
 287         if (tevent_req_nterror(state->req, status)) {
 288                 return;
 289         }
 290
 291         finddcs_cldap_next_server(state);
 292 }
 293
 294
 295 NTSTATUS finddcs_cldap_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx, struct finddcs *io)
 296 {
 297         struct finddcs_cldap_state *state = tevent_req_data(req, struct finddcs_cldap_state);
 298         bool ok;
 299         NTSTATUS status;
 300
 301         ok = tevent_req_poll(req, state->ev);
 302         if (!ok) {
 303                 talloc_free(req);
 304                 return NT_STATUS_INTERNAL_ERROR;
 305         }
 306         status = tevent_req_simple_recv_ntstatus(req);
 307         if (NT_STATUS_IS_OK(status)) {
 308                 talloc_steal(mem_ctx, state->netlogon);
 309                 io->out.netlogon = state->netlogon->out.netlogon;
 310                 io->out.address = talloc_steal(mem_ctx, state->srv_addresses[state->srv_address_index]);
 311         }
 312         tevent_req_received(req);
 313         return status;
 314 }
 315
 316 NTSTATUS finddcs_cldap(TALLOC_CTX *mem_ctx,
 317                        struct finddcs *io,
 318                        struct resolve_context *resolve_ctx,
 319                        struct tevent_context *event_ctx)
 320 {
 321         NTSTATUS status;
 322         struct tevent_req *req = finddcs_cldap_send(mem_ctx,
 323                                                     io,
 324                                                     resolve_ctx,
 325                                                     event_ctx);
 326         status = finddcs_cldap_recv(req, mem_ctx, io);
 327         talloc_free(req);
 328         return status;
 329 }