source4/libcli/finddcs_nbt.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    a composite API for finding a DC and its name
   5
   6    Copyright (C) Volker Lendecke 2005
   7    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2006
   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 "lib/messaging/irpc.h"
  26 #include "librpc/gen_ndr/ndr_irpc_c.h"
  27 #include "libcli/composite/composite.h"
  28 #include "libcli/libcli.h"
  29 #include "libcli/resolve/resolve.h"
  30 #include "lib/util/tevent_ntstatus.h"
  31
  32 struct finddcs_nbt_state {
  33         struct tevent_context *ev;
  34         struct tevent_req *req;
  35         struct messaging_context *msg_ctx;
  36
  37         const char *my_netbios_name;
  38         const char *domain_name;
  39         struct dom_sid *domain_sid;
  40
  41         struct nbtd_getdcname r;
  42         struct nbt_name_status node_status;
  43
  44         int num_dcs;
  45         struct nbt_dc_name *dcs;
  46         uint16_t nbt_port;
  47 };
  48
  49 static void finddcs_nbt_name_resolved(struct composite_context *ctx);
  50 static void finddcs_nbt_getdc_replied(struct tevent_req *subreq);
  51 static void fallback_node_status(struct finddcs_nbt_state *state);
  52 static void fallback_node_status_replied(struct nbt_name_request *name_req);
  53
  54 /*
  55  * Setup and send off the a normal name resolution for the target name.
  56  *
  57  * The domain_sid parameter is optional, and is used in the subsequent getdc request.
  58  *
  59  * This will try a GetDC request, but this may not work.  It will try
  60  * a node status as a fallback, then return no name (but still include
  61  * the IP)
  62  */
  63
  64 struct tevent_req *finddcs_nbt_send(TALLOC_CTX *mem_ctx,
  65                                 const char *my_netbios_name,
  66                                 uint16_t nbt_port,
  67                                 const char *domain_name,
  68                                 int name_type,
  69                                 struct dom_sid *domain_sid,
  70                                 struct resolve_context *resolve_ctx,
  71                                 struct tevent_context *event_ctx,
  72                                 struct messaging_context *msg_ctx)
  73 {
  74         struct finddcs_nbt_state *state;
  75         struct nbt_name name;
  76         struct tevent_req *req;
  77         struct composite_context *creq;
  78
  79         req = tevent_req_create(mem_ctx, &state, struct finddcs_nbt_state);
  80         if (req == NULL) {
  81                 return NULL;
  82         }
  83
  84         state->req = req;
  85         state->ev = event_ctx;
  86         state->nbt_port = nbt_port;
  87         state->my_netbios_name = talloc_strdup(state, my_netbios_name);
  88         if (tevent_req_nomem(state->my_netbios_name, req)) {
  89                 return tevent_req_post(req, event_ctx);
  90         }
  91         state->domain_name = talloc_strdup(state, domain_name);
  92         if (tevent_req_nomem(state->domain_name, req)) {
  93                 return tevent_req_post(req, event_ctx);
  94         }
  95
  96         if (domain_sid) {
  97                 state->domain_sid = talloc_reference(state, domain_sid);
  98                 if (tevent_req_nomem(state->domain_sid, req)) {
  99                         return tevent_req_post(req, event_ctx);
 100                 }
 101         } else {
 102                 state->domain_sid = NULL;
 103         }
 104
 105         state->msg_ctx = msg_ctx;
 106
 107         make_nbt_name(&name, state->domain_name, name_type);
 108         creq = resolve_name_send(resolve_ctx, state, &name, event_ctx);
 109         if (tevent_req_nomem(creq, req)) {
 110                 return tevent_req_post(req, event_ctx);
 111         }
 112         creq->async.fn = finddcs_nbt_name_resolved;
 113         creq->async.private_data = state;
 114
 115         return req;
 116 }
 117
 118 /* Having got an name query answer, fire off a GetDC request, so we
 119  * can find the target's all-important name.  (Kerberos and some
 120  * netlogon operations are quite picky about names)
 121  *
 122  * The name is a courtesy, if we don't find it, don't completely fail.
 123  *
 124  * However, if the nbt server is down, fall back to a node status
 125  * request
 126  */
 127 static void finddcs_nbt_name_resolved(struct composite_context *ctx)
 128 {
 129         struct finddcs_nbt_state *state =
 130                 talloc_get_type(ctx->async.private_data, struct finddcs_nbt_state);
 131         struct tevent_req *subreq;
 132         struct dcerpc_binding_handle *irpc_handle;
 133         const char *address;
 134         NTSTATUS status;
 135
 136         status = resolve_name_recv(ctx, state, &address);
 137         if (tevent_req_nterror(state->req, status)) {
 138                 return;
 139         }
 140
 141         /* TODO: This should try and find all the DCs, and give the
 142          * caller them in the order they responded */
 143
 144         state->num_dcs = 1;
 145         state->dcs = talloc_array(state, struct nbt_dc_name, state->num_dcs);
 146         if (tevent_req_nomem(state->dcs, state->req)) {
 147                 return;
 148         }
 149
 150         state->dcs[0].address = talloc_steal(state->dcs, address);
 151
 152         /* Try and find the nbt server.  Fallback to a node status
 153          * request if we can't make this happen The nbt server just
 154          * might not be running, or we may not have a messaging
 155          * context (not root etc) */
 156         if (!state->msg_ctx) {
 157                 fallback_node_status(state);
 158                 return;
 159         }
 160
 161         irpc_handle = irpc_binding_handle_by_name(state, state->msg_ctx,
 162                                                   "nbt_server", &ndr_table_irpc);
 163         if (irpc_handle == NULL) {
 164                 fallback_node_status(state);
 165                 return;
 166         }
 167
 168         state->r.in.domainname = state->domain_name;
 169         state->r.in.ip_address = state->dcs[0].address;
 170         state->r.in.my_computername = state->my_netbios_name;
 171         state->r.in.my_accountname = talloc_asprintf(state, "%s$", state->my_netbios_name);
 172         if (tevent_req_nomem(state->r.in.my_accountname, state->req)) {
 173                 return;
 174         }
 175         state->r.in.account_control = ACB_WSTRUST;
 176         state->r.in.domain_sid = state->domain_sid;
 177         if (state->r.in.domain_sid == NULL) {
 178                 state->r.in.domain_sid = talloc_zero(state, struct dom_sid);
 179         }
 180
 181         subreq = dcerpc_nbtd_getdcname_r_send(state, state->ev,
 182                                               irpc_handle, &state->r);
 183         if (tevent_req_nomem(subreq, state->req)) {
 184                 return;
 185         }
 186         tevent_req_set_callback(subreq, finddcs_nbt_getdc_replied, state);
 187 }
 188
 189 /* Called when the GetDC request returns */
 190 static void finddcs_nbt_getdc_replied(struct tevent_req *subreq)
 191 {
 192         struct finddcs_nbt_state *state =
 193                 tevent_req_callback_data(subreq,
 194                 struct finddcs_nbt_state);
 195         NTSTATUS status;
 196
 197         status = dcerpc_nbtd_getdcname_r_recv(subreq, state);
 198         TALLOC_FREE(subreq);
 199         if (!NT_STATUS_IS_OK(status)) {
 200                 fallback_node_status(state);
 201                 return;
 202         }
 203
 204         state->dcs[0].name = talloc_steal(state->dcs, state->r.out.dcname);
 205         tevent_req_done(state->req);
 206 }
 207
 208 /* The GetDC request might not be available (such as occours when the
 209  * NBT server is down).  Fallback to a node status.  It is the best
 210  * hope we have... */
 211 static void fallback_node_status(struct finddcs_nbt_state *state)
 212 {
 213         struct nbt_name_socket *nbtsock;
 214         struct nbt_name_request *name_req;
 215
 216         state->node_status.in.name.name = "*";
 217         state->node_status.in.name.type = NBT_NAME_CLIENT;
 218         state->node_status.in.name.scope = NULL;
 219         state->node_status.in.dest_addr = state->dcs[0].address;
 220         state->node_status.in.dest_port = state->nbt_port;
 221         state->node_status.in.timeout = 1;
 222         state->node_status.in.retries = 2;
 223
 224         nbtsock = nbt_name_socket_init(state, state->ev);
 225         if (tevent_req_nomem(nbtsock, state->req)) {
 226                 return;
 227         }
 228
 229         name_req = nbt_name_status_send(nbtsock, &state->node_status);
 230         if (tevent_req_nomem(name_req, state->req)) {
 231                 return;
 232         }
 233
 234         name_req->async.fn = fallback_node_status_replied;
 235         name_req->async.private_data = state;
 236 }
 237
 238 /* We have a node status reply (or perhaps a timeout) */
 239 static void fallback_node_status_replied(struct nbt_name_request *name_req)
 240 {
 241         int i;
 242         struct finddcs_nbt_state *state = talloc_get_type(name_req->async.private_data, struct finddcs_nbt_state);
 243         NTSTATUS status;
 244
 245         status = nbt_name_status_recv(name_req, state, &state->node_status);
 246         if (tevent_req_nterror(state->req, status)) {
 247                 return;
 248         }
 249
 250         for (i=0; i < state->node_status.out.status.num_names; i++) {
 251                 int j;
 252                 if (state->node_status.out.status.names[i].type == NBT_NAME_SERVER) {
 253                         char *name = talloc_strndup(state->dcs, state->node_status.out.status.names[0].name, 15);
 254                         /* Strip space padding */
 255                         if (name) {
 256                                 j = MIN(strlen(name), 15);
 257                                 for (; j > 0 && name[j - 1] == ' '; j--) {
 258                                         name[j - 1] = '\0';
 259                                 }
 260                         }
 261                         state->dcs[0].name = name;
 262                         tevent_req_done(state->req);
 263                         return;
 264                 }
 265         }
 266         tevent_req_nterror(state->req, NT_STATUS_NO_LOGON_SERVERS);
 267 }
 268
 269 NTSTATUS finddcs_nbt_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
 270                       int *num_dcs, struct nbt_dc_name **dcs)
 271 {
 272         struct finddcs_nbt_state *state = tevent_req_data(req, struct finddcs_nbt_state);
 273         bool ok;
 274         NTSTATUS status;
 275
 276         ok = tevent_req_poll(req, state->ev);
 277         if (!ok) {
 278                 talloc_free(req);
 279                 return NT_STATUS_INTERNAL_ERROR;
 280         }
 281         status = tevent_req_simple_recv_ntstatus(req);
 282         if (NT_STATUS_IS_OK(status)) {
 283                 *num_dcs = state->num_dcs;
 284                 *dcs = talloc_steal(mem_ctx, state->dcs);
 285         }
 286         talloc_free(req);
 287         return status;
 288 }
 289
 290 NTSTATUS finddcs_nbt(TALLOC_CTX *mem_ctx,
 291                  const char *my_netbios_name,
 292                  uint16_t nbt_port,
 293                  const char *domain_name, int name_type,
 294                  struct dom_sid *domain_sid,
 295                  struct resolve_context *resolve_ctx,
 296                  struct tevent_context *event_ctx,
 297                  struct messaging_context *msg_ctx,
 298                  int *num_dcs, struct nbt_dc_name **dcs)
 299 {
 300         struct tevent_req *req = finddcs_nbt_send(mem_ctx,
 301                                               my_netbios_name,
 302                                               nbt_port,
 303                                               domain_name, name_type,
 304                                               domain_sid,
 305                                               resolve_ctx,
 306                                               event_ctx, msg_ctx);
 307         return finddcs_nbt_recv(req, mem_ctx, num_dcs, dcs);
 308 }