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_name;
  40         const char **srv_addresses;
  41         uint32_t minimum_dc_flags;
  42         uint32_t srv_address_index;
  43         struct cldap_socket *cldap;
  44         struct cldap_netlogon *netlogon;
  45 };
  46
  47 static void finddcs_cldap_srv_resolved(struct composite_context *ctx);
  48 static void finddcs_cldap_netlogon_replied(struct tevent_req *req);
  49 static bool finddcs_cldap_srv_lookup(struct finddcs_cldap_state *state,
  50                                      struct finddcs *io,
  51                                      struct resolve_context *resolve_ctx,
  52                                      struct tevent_context *event_ctx);
  53 static bool finddcs_cldap_nbt_lookup(struct finddcs_cldap_state *state,
  54                                      struct finddcs *io,
  55                                      struct resolve_context *resolve_ctx,
  56                                      struct tevent_context *event_ctx);
  57 static void finddcs_cldap_name_resolved(struct composite_context *ctx);
  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 (strchr(state->domain_name, '.')) {
  95                 /* looks like a DNS name */
  96                 if (!finddcs_cldap_srv_lookup(state, io, resolve_ctx, event_ctx)) {
  97                         return tevent_req_post(req, event_ctx);
  98                 }
  99         } else {
 100                 if (!finddcs_cldap_nbt_lookup(state, io, resolve_ctx, event_ctx)) {
 101                         return tevent_req_post(req, event_ctx);
 102                 }
 103         }
 104
 105         return req;
 106 }
 107
 108 /*
 109   start a SRV DNS lookup
 110  */
 111 static bool finddcs_cldap_srv_lookup(struct finddcs_cldap_state *state,
 112                                      struct finddcs *io,
 113                                      struct resolve_context *resolve_ctx,
 114                                      struct tevent_context *event_ctx)
 115 {
 116         struct composite_context *creq;
 117         struct nbt_name name;
 118
 119         if (io->in.site_name) {
 120                 state->srv_name = talloc_asprintf(state, "_ldap._tcp.%s._sites.%s",
 121                                            io->in.site_name, io->in.domain_name);
 122         } else {
 123                 state->srv_name = talloc_asprintf(state, "_ldap._tcp.%s", io->in.domain_name);
 124         }
 125
 126         make_nbt_name(&name, state->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                 DEBUG(2,("finddcs: No matching CLDAP server found\n"));
 171                 return;
 172         }
 173
 174         state->netlogon = talloc_zero(state, struct cldap_netlogon);
 175         if (tevent_req_nomem(state->netlogon, state->req)) {
 176                 return;
 177         }
 178
 179         state->netlogon->in.dest_address = state->srv_addresses[state->srv_address_index];
 180         /* we should get the port from the SRV response */
 181         state->netlogon->in.dest_port = 389;
 182         if (strchr(state->domain_name, '.')) {
 183                 state->netlogon->in.realm = state->domain_name;
 184         }
 185         if (state->domain_sid) {
 186                 state->netlogon->in.domain_sid = dom_sid_string(state, state->domain_sid);
 187                 if (tevent_req_nomem(state->netlogon->in.domain_sid, state->req)) {
 188                         return;
 189                 }
 190         }
 191         state->netlogon->in.acct_control = -1;
 192         state->netlogon->in.version =
 193                 NETLOGON_NT_VERSION_5 |
 194                 NETLOGON_NT_VERSION_5EX |
 195                 NETLOGON_NT_VERSION_IP;
 196         state->netlogon->in.map_response = true;
 197
 198         subreq = cldap_netlogon_send(state, state->cldap, state->netlogon);
 199         if (tevent_req_nomem(subreq, state->req)) {
 200                 return;
 201         }
 202
 203         tevent_req_set_callback(subreq, finddcs_cldap_netlogon_replied, state);
 204 }
 205
 206
 207 /*
 208   we have a response from a CLDAP server for a netlogon request
 209  */
 210 static void finddcs_cldap_netlogon_replied(struct tevent_req *subreq)
 211 {
 212         struct finddcs_cldap_state *state;
 213         NTSTATUS status;
 214
 215         state = tevent_req_callback_data(subreq, struct finddcs_cldap_state);
 216
 217         status = cldap_netlogon_recv(subreq, state->netlogon, state->netlogon);
 218         talloc_free(subreq);
 219         if (!NT_STATUS_IS_OK(status)) {
 220                 state->srv_address_index++;
 221                 finddcs_cldap_next_server(state);
 222                 return;
 223         }
 224         if (state->minimum_dc_flags !=
 225             (state->minimum_dc_flags & state->netlogon->out.netlogon.data.nt5_ex.server_type)) {
 226                 /* the server didn't match the minimum requirements */
 227                 DEBUG(4,(__location__ ": Skipping DC %s with server_type=0x%08x - required 0x%08x\n",
 228                          state->srv_addresses[state->srv_address_index],
 229                          state->netlogon->out.netlogon.data.nt5_ex.server_type,
 230                          state->minimum_dc_flags));
 231                 state->srv_address_index++;
 232                 finddcs_cldap_next_server(state);
 233                 return;
 234         }
 235
 236         tevent_req_done(state->req);
 237 }
 238
 239 /*
 240    handle NBT name lookup reply
 241  */
 242 static void finddcs_cldap_name_resolved(struct composite_context *ctx)
 243 {
 244         struct finddcs_cldap_state *state =
 245                 talloc_get_type(ctx->async.private_data, struct finddcs_cldap_state);
 246         const char *address;
 247         NTSTATUS status;
 248
 249         status = resolve_name_recv(ctx, state, &address);
 250         if (tevent_req_nterror(state->req, status)) {
 251                 DEBUG(2,("finddcs: No matching NBT <1c> server found\n"));
 252                 return;
 253         }
 254
 255         DEBUG(4,("finddcs: Found NBT <1c> server at %s\n", address));
 256
 257         state->srv_addresses = talloc_array(state, const char *, 2);
 258         if (tevent_req_nomem(state->srv_addresses, state->req)) {
 259                 return;
 260         }
 261         state->srv_addresses[0] = address;
 262         state->srv_addresses[1] = NULL;
 263
 264         state->srv_address_index = 0;
 265
 266         status = cldap_socket_init(state, state->ev, NULL, NULL, &state->cldap);
 267         if (tevent_req_nterror(state->req, status)) {
 268                 return;
 269         }
 270
 271         finddcs_cldap_next_server(state);
 272 }
 273
 274
 275 /*
 276  * Having got a DNS SRV answer, fire off the first CLDAP request
 277  */
 278 static void finddcs_cldap_srv_resolved(struct composite_context *ctx)
 279 {
 280         struct finddcs_cldap_state *state =
 281                 talloc_get_type(ctx->async.private_data, struct finddcs_cldap_state);
 282         NTSTATUS status;
 283
 284         status = resolve_name_multiple_recv(ctx, state, &state->srv_addresses);
 285         if (tevent_req_nterror(state->req, status)) {
 286                 DEBUG(2,("finddcs: Failed to find SRV record for %s\n", state->srv_name));
 287                 return;
 288         }
 289
 290         state->srv_address_index = 0;
 291
 292         status = cldap_socket_init(state, state->ev, NULL, NULL, &state->cldap);
 293         if (tevent_req_nterror(state->req, status)) {
 294                 return;
 295         }
 296
 297         finddcs_cldap_next_server(state);
 298 }
 299
 300
 301 NTSTATUS finddcs_cldap_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx, struct finddcs *io)
 302 {
 303         struct finddcs_cldap_state *state = tevent_req_data(req, struct finddcs_cldap_state);
 304         bool ok;
 305         NTSTATUS status;
 306
 307         ok = tevent_req_poll(req, state->ev);
 308         if (!ok) {
 309                 talloc_free(req);
 310                 return NT_STATUS_INTERNAL_ERROR;
 311         }
 312         status = tevent_req_simple_recv_ntstatus(req);
 313         if (NT_STATUS_IS_OK(status)) {
 314                 talloc_steal(mem_ctx, state->netlogon);
 315                 io->out.netlogon = state->netlogon->out.netlogon;
 316                 io->out.address = talloc_steal(mem_ctx, state->srv_addresses[state->srv_address_index]);
 317         }
 318         tevent_req_received(req);
 319         return status;
 320 }
 321
 322 NTSTATUS finddcs_cldap(TALLOC_CTX *mem_ctx,
 323                        struct finddcs *io,
 324                        struct resolve_context *resolve_ctx,
 325                        struct tevent_context *event_ctx)
 326 {
 327         NTSTATUS status;
 328         struct tevent_req *req = finddcs_cldap_send(mem_ctx,
 329                                                     io,
 330                                                     resolve_ctx,
 331                                                     event_ctx);
 332         status = finddcs_cldap_recv(req, mem_ctx, io);
 333         talloc_free(req);
 334         return status;
 335 }