source4/libcli/finddcs.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 "lib/messaging/irpc.h"
  25 #include "librpc/gen_ndr/ndr_irpc.h"
  26 #include "librpc/gen_ndr/samr.h"
  27 #include "libcli/composite/composite.h"
  28 #include "libcli/libcli.h"
  29 #include "libcli/resolve/resolve.h"
  30 #include "libcli/finddcs.h"
  31
  32 struct finddcs_state {
  33         struct composite_context *ctx;
  34         struct messaging_context *msg_ctx;
  35
  36         const char *my_netbios_name;
  37         const char *domain_name;
  38         struct dom_sid *domain_sid;
  39
  40         struct nbtd_getdcname r;
  41         struct nbt_name_status node_status;
  42
  43         struct smb_iconv_convenience *iconv_convenience;
  44
  45         int num_dcs;
  46         struct nbt_dc_name *dcs;
  47         uint16_t nbt_port;
  48 };
  49
  50 static void finddcs_name_resolved(struct composite_context *ctx);
  51 static void finddcs_getdc_replied(struct irpc_request *ireq);
  52 static void fallback_node_status(struct finddcs_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 composite_context *finddcs_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 smb_iconv_convenience *iconv_convenience,
  72                                        struct resolve_context *resolve_ctx,
  73                                        struct tevent_context *event_ctx,
  74                                        struct messaging_context *msg_ctx)
  75 {
  76         struct composite_context *c, *creq;
  77         struct finddcs_state *state;
  78         struct nbt_name name;
  79
  80         c = composite_create(mem_ctx, event_ctx);
  81         if (c == NULL) return NULL;
  82
  83         state = talloc(c, struct finddcs_state);
  84         if (composite_nomem(state, c)) return c;
  85         c->private_data = state;
  86
  87         state->ctx = c;
  88
  89         state->nbt_port = nbt_port;
  90         state->my_netbios_name = talloc_strdup(state, my_netbios_name);
  91         state->domain_name = talloc_strdup(state, domain_name);
  92         state->iconv_convenience = iconv_convenience;
  93         if (composite_nomem(state->domain_name, c)) return c;
  94
  95         if (domain_sid) {
  96                 state->domain_sid = talloc_reference(state, domain_sid);
  97                 if (composite_nomem(state->domain_sid, c)) return c;
  98         } else {
  99                 state->domain_sid = NULL;
 100         }
 101
 102         state->msg_ctx = msg_ctx;
 103
 104         make_nbt_name(&name, state->domain_name, name_type);
 105         creq = resolve_name_send(resolve_ctx, state, &name, event_ctx);
 106         composite_continue(c, creq, finddcs_name_resolved, state);
 107         return c;
 108 }
 109
 110 /* Having got an name query answer, fire off a GetDC request, so we
 111  * can find the target's all-important name.  (Kerberos and some
 112  * netlogon operations are quite picky about names)
 113  *
 114  * The name is a courtesy, if we don't find it, don't completely fail.
 115  *
 116  * However, if the nbt server is down, fall back to a node status
 117  * request
 118  */
 119 static void finddcs_name_resolved(struct composite_context *ctx)
 120 {
 121         struct finddcs_state *state =
 122                 talloc_get_type(ctx->async.private_data, struct finddcs_state);
 123         struct irpc_request *ireq;
 124         struct server_id *nbt_servers;
 125         const char *address;
 126
 127         state->ctx->status = resolve_name_recv(ctx, state, &address);
 128         if (!composite_is_ok(state->ctx)) return;
 129
 130         /* TODO: This should try and find all the DCs, and give the
 131          * caller them in the order they responded */
 132
 133         state->num_dcs = 1;
 134         state->dcs = talloc_array(state, struct nbt_dc_name, state->num_dcs);
 135         if (composite_nomem(state->dcs, state->ctx)) return;
 136
 137         state->dcs[0].address = talloc_steal(state->dcs, address);
 138
 139         /* Try and find the nbt server.  Fallback to a node status
 140          * request if we can't make this happen The nbt server just
 141          * might not be running, or we may not have a messaging
 142          * context (not root etc) */
 143         if (!state->msg_ctx) {
 144                 fallback_node_status(state);
 145                 return;
 146         }
 147
 148         nbt_servers = irpc_servers_byname(state->msg_ctx, state, "nbt_server");
 149         if ((nbt_servers == NULL) || (nbt_servers[0].id == 0)) {
 150                 fallback_node_status(state);
 151                 return;
 152         }
 153
 154         state->r.in.domainname = state->domain_name;
 155         state->r.in.ip_address = state->dcs[0].address;
 156         state->r.in.my_computername = state->my_netbios_name;
 157         state->r.in.my_accountname = talloc_asprintf(state, "%s$", state->my_netbios_name);
 158         if (composite_nomem(state->r.in.my_accountname, state->ctx)) return;
 159         state->r.in.account_control = ACB_WSTRUST;
 160         state->r.in.domain_sid = state->domain_sid;
 161
 162         ireq = irpc_call_send(state->msg_ctx, nbt_servers[0],
 163                               &ndr_table_irpc, NDR_NBTD_GETDCNAME,
 164                               &state->r, state);
 165         if (!ireq) {
 166                 fallback_node_status(state);
 167                 return;
 168         }
 169
 170         composite_continue_irpc(state->ctx, ireq, finddcs_getdc_replied, state);
 171 }
 172
 173 /* Called when the GetDC request returns */
 174 static void finddcs_getdc_replied(struct irpc_request *ireq)
 175 {
 176         struct finddcs_state *state =
 177                 talloc_get_type(ireq->async.private_data, struct finddcs_state);
 178
 179         state->ctx->status = irpc_call_recv(ireq);
 180         if (!composite_is_ok(state->ctx)) return;
 181
 182         state->dcs[0].name = talloc_steal(state->dcs, state->r.out.dcname);
 183         composite_done(state->ctx);
 184 }
 185
 186 /* The GetDC request might not be available (such as occours when the
 187  * NBT server is down).  Fallback to a node status.  It is the best
 188  * hope we have... */
 189 static void fallback_node_status(struct finddcs_state *state)
 190 {
 191         struct nbt_name_socket *nbtsock;
 192         struct nbt_name_request *name_req;
 193
 194         state->node_status.in.name.name = "*";
 195         state->node_status.in.name.type = NBT_NAME_CLIENT;
 196         state->node_status.in.name.scope = NULL;
 197         state->node_status.in.dest_addr = state->dcs[0].address;
 198         state->node_status.in.dest_port = state->nbt_port;
 199         state->node_status.in.timeout = 1;
 200         state->node_status.in.retries = 2;
 201
 202         nbtsock = nbt_name_socket_init(state, state->ctx->event_ctx,
 203                                        state->iconv_convenience);
 204         if (composite_nomem(nbtsock, state->ctx)) return;
 205
 206         name_req = nbt_name_status_send(nbtsock, &state->node_status);
 207         if (composite_nomem(name_req, state->ctx)) return;
 208
 209         composite_continue_nbt(state->ctx,
 210                                name_req,
 211                                fallback_node_status_replied,
 212                                state);
 213 }
 214
 215 /* We have a node status reply (or perhaps a timeout) */
 216 static void fallback_node_status_replied(struct nbt_name_request *name_req)
 217 {
 218         int i;
 219         struct finddcs_state *state = talloc_get_type(name_req->async.private_data, struct finddcs_state);
 220         state->ctx->status = nbt_name_status_recv(name_req, state, &state->node_status);
 221         if (!composite_is_ok(state->ctx)) return;
 222
 223         for (i=0; i < state->node_status.out.status.num_names; i++) {
 224                 int j;
 225                 if (state->node_status.out.status.names[i].type == NBT_NAME_SERVER) {
 226                         char *name = talloc_strndup(state->dcs, state->node_status.out.status.names[0].name, 15);
 227                         /* Strip space padding */
 228                         if (name) {
 229                                 j = MIN(strlen(name), 15);
 230                                 for (; j > 0 && name[j - 1] == ' '; j--) {
 231                                         name[j - 1] = '\0';
 232                                 }
 233                         }
 234                         state->dcs[0].name = name;
 235                         composite_done(state->ctx);
 236                         return;
 237                 }
 238         }
 239         composite_error(state->ctx, NT_STATUS_NO_LOGON_SERVERS);
 240 }
 241
 242 NTSTATUS finddcs_recv(struct composite_context *c, TALLOC_CTX *mem_ctx,
 243                       int *num_dcs, struct nbt_dc_name **dcs)
 244 {
 245         NTSTATUS status = composite_wait(c);
 246         if (NT_STATUS_IS_OK(status)) {
 247                 struct finddcs_state *state =
 248                         talloc_get_type(c->private_data, struct finddcs_state);
 249                 *num_dcs = state->num_dcs;
 250                 *dcs = talloc_steal(mem_ctx, state->dcs);
 251         }
 252         talloc_free(c);
 253         return status;
 254 }
 255
 256 NTSTATUS finddcs(TALLOC_CTX *mem_ctx,
 257                  const char *my_netbios_name,
 258                  uint16_t nbt_port,
 259                  const char *domain_name, int name_type,
 260                  struct dom_sid *domain_sid,
 261                  struct smb_iconv_convenience *iconv_convenience,
 262                  struct resolve_context *resolve_ctx,
 263                  struct tevent_context *event_ctx,
 264                  struct messaging_context *msg_ctx,
 265                  int *num_dcs, struct nbt_dc_name **dcs)
 266 {
 267         struct composite_context *c = finddcs_send(mem_ctx,
 268                                                    my_netbios_name,
 269                                                    nbt_port,
 270                                                    domain_name, name_type,
 271                                                    domain_sid,
 272                                                    iconv_convenience,
 273                                                    resolve_ctx,
 274                                                    event_ctx, msg_ctx);
 275         return finddcs_recv(c, mem_ctx, num_dcs, dcs);
 276 }