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