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 #include "libcli/finddc.h"
  32
  33 struct finddcs_nbt_state {
  34         struct tevent_context *ev;
  35         struct tevent_req *req;
  36         struct imessaging_context *msg_ctx;
  37
  38         const char *my_netbios_name;
  39         const char *domain_name;
  40         struct dom_sid *domain_sid;
  41
  42         struct nbtd_getdcname r;
  43         struct nbt_name_status node_status;
  44
  45         int num_dcs;
  46         struct nbt_dc_name *dcs;
  47         uint16_t nbt_port;
  48 };
  49
  50 static void finddcs_nbt_name_resolved(struct composite_context *ctx);
  51 static void finddcs_nbt_getdc_replied(struct tevent_req *subreq);
  52 static void fallback_node_status(struct finddcs_nbt_state *state);
  53 static void fallback_node_status_replied(struct nbt_name_request *name_req);
  54
  55 /*
  56  * Setup and send off the a normal name resolution for the target name.
  57  *
  58  * The domain_sid parameter is optional, and is used in the subsequent getdc request.
  59  *
  60  * This will try a GetDC request, but this may not work.  It will try
  61  * a node status as a fallback, then return no name (but still include
  62  * the IP)
  63  */
  64
  65 struct tevent_req *finddcs_nbt_send(TALLOC_CTX *mem_ctx,
  66                                 const char *my_netbios_name,
  67                                 uint16_t nbt_port,
  68                                 const char *domain_name,
  69                                 int name_type,
  70                                 struct dom_sid *domain_sid,
  71                                 struct resolve_context *resolve_ctx,
  72                                 struct tevent_context *event_ctx,
  73                                 struct imessaging_context *msg_ctx)
  74 {
  75         struct finddcs_nbt_state *state;
  76         struct nbt_name name;
  77         struct tevent_req *req;
  78         struct composite_context *creq;
  79
  80         req = tevent_req_create(mem_ctx, &state, struct finddcs_nbt_state);
  81         if (req == NULL) {
  82                 return NULL;
  83         }
  84
  85         state->req = req;
  86         state->ev = event_ctx;
  87         state->nbt_port = nbt_port;
  88         state->my_netbios_name = talloc_strdup(state, my_netbios_name);
  89         if (tevent_req_nomem(state->my_netbios_name, req)) {
  90                 return tevent_req_post(req, event_ctx);
  91         }
  92         state->domain_name = talloc_strdup(state, domain_name);
  93         if (tevent_req_nomem(state->domain_name, req)) {
  94                 return tevent_req_post(req, event_ctx);
  95         }
  96
  97         if (domain_sid) {
  98                 state->domain_sid = talloc_reference(state, domain_sid);
  99                 if (tevent_req_nomem(state->domain_sid, req)) {
 100                         return tevent_req_post(req, event_ctx);
 101                 }
 102         } else {
 103                 state->domain_sid = NULL;
 104         }
 105
 106         state->msg_ctx = msg_ctx;
 107
 108         make_nbt_name(&name, state->domain_name, name_type);
 109         creq = resolve_name_send(resolve_ctx, state, &name, event_ctx);
 110         if (tevent_req_nomem(creq, req)) {
 111                 return tevent_req_post(req, event_ctx);
 112         }
 113         creq->async.fn = finddcs_nbt_name_resolved;
 114         creq->async.private_data = state;
 115
 116         return req;
 117 }
 118
 119 /* Having got an name query answer, fire off a GetDC request, so we
 120  * can find the target's all-important name.  (Kerberos and some
 121  * netlogon operations are quite picky about names)
 122  *
 123  * The name is a courtesy, if we don't find it, don't completely fail.
 124  *
 125  * However, if the nbt server is down, fall back to a node status
 126  * request
 127  */
 128 static void finddcs_nbt_name_resolved(struct composite_context *ctx)
 129 {
 130         struct finddcs_nbt_state *state =
 131                 talloc_get_type(ctx->async.private_data, struct finddcs_nbt_state);
 132         struct tevent_req *subreq;
 133         struct dcerpc_binding_handle *irpc_handle;
 134         const char *address;
 135         NTSTATUS status;
 136
 137         status = resolve_name_recv(ctx, state, &address);
 138         if (tevent_req_nterror(state->req, status)) {
 139                 return;
 140         }
 141
 142         /* TODO: This should try and find all the DCs, and give the
 143          * caller them in the order they responded */
 144
 145         state->num_dcs = 1;
 146         state->dcs = talloc_array(state, struct nbt_dc_name, state->num_dcs);
 147         if (tevent_req_nomem(state->dcs, state->req)) {
 148                 return;
 149         }
 150
 151         state->dcs[0].address = talloc_steal(state->dcs, address);
 152
 153         /* Try and find the nbt server.  Fallback to a node status
 154          * request if we can't make this happen The nbt server just
 155          * might not be running, or we may not have a messaging
 156          * context (not root etc) */
 157         if (!state->msg_ctx) {
 158                 fallback_node_status(state);
 159                 return;
 160         }
 161
 162         irpc_handle = irpc_binding_handle_by_name(state, state->msg_ctx,
 163                                                   "nbt_server", &ndr_table_irpc);
 164         if (irpc_handle == NULL) {
 165                 fallback_node_status(state);
 166                 return;
 167         }
 168
 169         state->r.in.domainname = state->domain_name;
 170         state->r.in.ip_address = state->dcs[0].address;
 171         state->r.in.my_computername = state->my_netbios_name;
 172         state->r.in.my_accountname = talloc_asprintf(state, "%s$", state->my_netbios_name);
 173         if (tevent_req_nomem(state->r.in.my_accountname, state->req)) {
 174                 return;
 175         }
 176         state->r.in.account_control = ACB_WSTRUST;
 177         state->r.in.domain_sid = state->domain_sid;
 178         if (state->r.in.domain_sid == NULL) {
 179                 state->r.in.domain_sid = talloc_zero(state, struct dom_sid);
 180         }
 181
 182         subreq = dcerpc_nbtd_getdcname_r_send(state, state->ev,
 183                                               irpc_handle, &state->r);
 184         if (tevent_req_nomem(subreq, state->req)) {
 185                 return;
 186         }
 187         tevent_req_set_callback(subreq, finddcs_nbt_getdc_replied, state);
 188 }
 189
 190 /* Called when the GetDC request returns */
 191 static void finddcs_nbt_getdc_replied(struct tevent_req *subreq)
 192 {
 193         struct finddcs_nbt_state *state =
 194                 tevent_req_callback_data(subreq,
 195                 struct finddcs_nbt_state);
 196         NTSTATUS status;
 197
 198         status = dcerpc_nbtd_getdcname_r_recv(subreq, state);
 199         TALLOC_FREE(subreq);
 200         if (!NT_STATUS_IS_OK(status)) {
 201                 fallback_node_status(state);
 202                 return;
 203         }
 204
 205         state->dcs[0].name = talloc_steal(state->dcs, state->r.out.dcname);
 206         tevent_req_done(state->req);
 207 }
 208
 209 /* The GetDC request might not be available (such as occours when the
 210  * NBT server is down).  Fallback to a node status.  It is the best
 211  * hope we have... */
 212 static void fallback_node_status(struct finddcs_nbt_state *state)
 213 {
 214         struct nbt_name_socket *nbtsock;
 215         struct nbt_name_request *name_req;
 216
 217         state->node_status.in.name.name = "*";
 218         state->node_status.in.name.type = NBT_NAME_CLIENT;
 219         state->node_status.in.name.scope = NULL;
 220         state->node_status.in.dest_addr = state->dcs[0].address;
 221         state->node_status.in.dest_port = state->nbt_port;
 222         state->node_status.in.timeout = 1;
 223         state->node_status.in.retries = 2;
 224
 225         nbtsock = nbt_name_socket_init(state, state->ev);
 226         if (tevent_req_nomem(nbtsock, state->req)) {
 227                 return;
 228         }
 229
 230         name_req = nbt_name_status_send(nbtsock, &state->node_status);
 231         if (tevent_req_nomem(name_req, state->req)) {
 232                 return;
 233         }
 234
 235         name_req->async.fn = fallback_node_status_replied;
 236         name_req->async.private_data = state;
 237 }
 238
 239 /* We have a node status reply (or perhaps a timeout) */
 240 static void fallback_node_status_replied(struct nbt_name_request *name_req)
 241 {
 242         int i;
 243         struct finddcs_nbt_state *state = talloc_get_type(name_req->async.private_data, struct finddcs_nbt_state);
 244         NTSTATUS status;
 245
 246         status = nbt_name_status_recv(name_req, state, &state->node_status);
 247         if (tevent_req_nterror(state->req, status)) {
 248                 return;
 249         }
 250
 251         for (i=0; i < state->node_status.out.status.num_names; i++) {
 252                 int j;
 253                 if (state->node_status.out.status.names[i].type == NBT_NAME_SERVER) {
 254                         char *name = talloc_strndup(state->dcs, state->node_status.out.status.names[0].name, 15);
 255                         /* Strip space padding */
 256                         if (name) {
 257                                 j = MIN(strlen(name), 15);
 258                                 for (; j > 0 && name[j - 1] == ' '; j--) {
 259                                         name[j - 1] = '\0';
 260                                 }
 261                         }
 262                         state->dcs[0].name = name;
 263                         tevent_req_done(state->req);
 264                         return;
 265                 }
 266         }
 267         tevent_req_nterror(state->req, NT_STATUS_NO_LOGON_SERVERS);
 268 }
 269
 270 NTSTATUS finddcs_nbt_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
 271                       int *num_dcs, struct nbt_dc_name **dcs)
 272 {
 273         struct finddcs_nbt_state *state = tevent_req_data(req, struct finddcs_nbt_state);
 274         bool ok;
 275         NTSTATUS status;
 276
 277         ok = tevent_req_poll(req, state->ev);
 278         if (!ok) {
 279                 talloc_free(req);
 280                 return NT_STATUS_INTERNAL_ERROR;
 281         }
 282         status = tevent_req_simple_recv_ntstatus(req);
 283         if (NT_STATUS_IS_OK(status)) {
 284                 *num_dcs = state->num_dcs;
 285                 *dcs = talloc_steal(mem_ctx, state->dcs);
 286         }
 287         talloc_free(req);
 288         return status;
 289 }
 290
 291 NTSTATUS finddcs_nbt(TALLOC_CTX *mem_ctx,
 292                  const char *my_netbios_name,
 293                  uint16_t nbt_port,
 294                  const char *domain_name, int name_type,
 295                  struct dom_sid *domain_sid,
 296                  struct resolve_context *resolve_ctx,
 297                  struct tevent_context *event_ctx,
 298                  struct imessaging_context *msg_ctx,
 299                  int *num_dcs, struct nbt_dc_name **dcs)
 300 {
 301         struct tevent_req *req = finddcs_nbt_send(mem_ctx,
 302                                               my_netbios_name,
 303                                               nbt_port,
 304                                               domain_name, name_type,
 305                                               domain_sid,
 306                                               resolve_ctx,
 307                                               event_ctx, msg_ctx);
 308         return finddcs_nbt_recv(req, mem_ctx, num_dcs, dcs);
 309 }