source3/rpc_server/rpc_ep_register.c

   1 /*
   2  *  Unix SMB/CIFS implementation.
   3  *
   4  *  RPC Endpoint Registration
   5  *
   6  *  Copyright (c) 2011      Andreas Schneider <asn@samba.org>
   7  *
   8  *  This program is free software; you can redistribute it and/or modify
   9  *  it under the terms of the GNU General Public License as published by
  10  *  the Free Software Foundation; either version 3 of the License, or
  11  *  (at your option) any later version.
  12  *
  13  *  This program is distributed in the hope that it will be useful,
  14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *  GNU General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License
  19  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  20  */
  21
  22 #include "includes.h"
  23 #include "ntdomain.h"
  24
  25 #include "../librpc/gen_ndr/ndr_epmapper_c.h"
  26
  27 #include "librpc/rpc/dcerpc_ep.h"
  28 #include "rpc_server/rpc_ep_register.h"
  29
  30 static void rpc_ep_register_loop(struct tevent_req *subreq);
  31 static NTSTATUS rpc_ep_try_register(TALLOC_CTX *mem_ctx,
  32                                     struct tevent_context *ev_ctx,
  33                                     struct messaging_context *msg_ctx,
  34                                     const struct ndr_interface_table *iface,
  35                                     const struct dcerpc_binding_vector *v,
  36                                     struct dcerpc_binding_handle **pbh);
  37
  38 struct rpc_ep_register_state {
  39         struct dcerpc_binding_handle *h;
  40
  41         struct tevent_context *ev_ctx;
  42         struct messaging_context *msg_ctx;
  43
  44         const struct ndr_interface_table *iface;
  45         const struct dcerpc_binding_vector *vector;
  46
  47         uint32_t wait_time;
  48 };
  49
  50 NTSTATUS rpc_ep_register(struct tevent_context *ev_ctx,
  51                          struct messaging_context *msg_ctx,
  52                          const struct ndr_interface_table *iface,
  53                          const struct dcerpc_binding_vector *v)
  54 {
  55         struct rpc_ep_register_state *state;
  56         struct tevent_req *req;
  57
  58         state = talloc(ev_ctx, struct rpc_ep_register_state);
  59         if (state == NULL) {
  60                 return NT_STATUS_NO_MEMORY;
  61         }
  62
  63         state->wait_time = 1;
  64         state->ev_ctx = ev_ctx;
  65         state->msg_ctx = msg_ctx;
  66         state->iface = iface;
  67         state->vector = dcerpc_binding_vector_dup(state, v);
  68         if (state->vector == NULL) {
  69                 talloc_free(state);
  70                 return NT_STATUS_NO_MEMORY;
  71         }
  72
  73         req = tevent_wakeup_send(state,
  74                                  state->ev_ctx,
  75                                  timeval_current_ofs(1, 0));
  76         if (req == NULL) {
  77                 talloc_free(state);
  78                 return NT_STATUS_NO_MEMORY;
  79         }
  80
  81         tevent_req_set_callback(req, rpc_ep_register_loop, state);
  82
  83         return NT_STATUS_OK;
  84 }
  85
  86 #define MONITOR_WAIT_TIME 30
  87 static void rpc_ep_monitor_loop(struct tevent_req *subreq);
  88
  89 static void rpc_ep_register_loop(struct tevent_req *subreq)
  90 {
  91         struct rpc_ep_register_state *state =
  92                 tevent_req_callback_data(subreq, struct rpc_ep_register_state);
  93         NTSTATUS status;
  94         bool ok;
  95
  96         ok = tevent_wakeup_recv(subreq);
  97         TALLOC_FREE(subreq);
  98         if (!ok) {
  99                 talloc_free(state);
 100                 return;
 101         }
 102
 103         status = rpc_ep_try_register(state,
 104                                      state->ev_ctx,
 105                                      state->msg_ctx,
 106                                      state->iface,
 107                                      state->vector,
 108                                      &state->h);
 109         if (NT_STATUS_IS_OK(status)) {
 110                 /* endpoint registered, monitor the connnection. */
 111                 subreq = tevent_wakeup_send(state,
 112                                             state->ev_ctx,
 113                                             timeval_current_ofs(MONITOR_WAIT_TIME, 0));
 114                 if (subreq == NULL) {
 115                         talloc_free(state);
 116                         return;
 117                 }
 118
 119                 tevent_req_set_callback(subreq, rpc_ep_monitor_loop, state);
 120                 return;
 121         }
 122
 123         state->wait_time = state->wait_time * 2;
 124         if (state->wait_time > 16) {
 125                 DEBUG(0, ("Failed to register endpoint '%s'!\n",
 126                            state->iface->name));
 127                 state->wait_time = 16;
 128         }
 129
 130         subreq = tevent_wakeup_send(state,
 131                                     state->ev_ctx,
 132                                     timeval_current_ofs(state->wait_time, 0));
 133         if (subreq == NULL) {
 134                 talloc_free(state);
 135                 return;
 136         }
 137
 138         tevent_req_set_callback(subreq, rpc_ep_register_loop, state);
 139         return;
 140 }
 141
 142 static NTSTATUS rpc_ep_try_register(TALLOC_CTX *mem_ctx,
 143                                     struct tevent_context *ev_ctx,
 144                                     struct messaging_context *msg_ctx,
 145                                     const struct ndr_interface_table *iface,
 146                                     const struct dcerpc_binding_vector *v,
 147                                     struct dcerpc_binding_handle **pbh)
 148 {
 149         NTSTATUS status;
 150
 151         status = dcerpc_ep_register(mem_ctx,
 152                                     msg_ctx,
 153                                     iface,
 154                                     v,
 155                                     &iface->syntax_id.uuid,
 156                                     iface->name,
 157                                     pbh);
 158         if (!NT_STATUS_IS_OK(status)) {
 159                 return status;
 160         }
 161
 162         return status;
 163 }
 164
 165 /*
 166  * Monitor the connection to the endpoint mapper and if it goes away, try to
 167  * register the endpoint.
 168  */
 169 static void rpc_ep_monitor_loop(struct tevent_req *subreq)
 170 {
 171         struct rpc_ep_register_state *state =
 172                 tevent_req_callback_data(subreq, struct rpc_ep_register_state);
 173         struct policy_handle entry_handle;
 174         struct dcerpc_binding map_binding;
 175         struct epm_twr_p_t towers[10];
 176         struct epm_twr_t *map_tower;
 177         uint32_t num_towers = 0;
 178         struct GUID object;
 179         NTSTATUS status;
 180         uint32_t result = EPMAPPER_STATUS_CANT_PERFORM_OP;
 181         TALLOC_CTX *tmp_ctx;
 182         bool ok;
 183
 184         ZERO_STRUCT(object);
 185         ZERO_STRUCT(entry_handle);
 186
 187         tmp_ctx = talloc_stackframe();
 188         if (tmp_ctx == NULL) {
 189                 talloc_free(state);
 190                 return;
 191         }
 192
 193         ok = tevent_wakeup_recv(subreq);
 194         TALLOC_FREE(subreq);
 195         if (!ok) {
 196                 talloc_free(tmp_ctx);
 197                 talloc_free(state);
 198                 return;
 199         }
 200
 201         /* Create map tower */
 202         map_binding.transport = NCACN_NP;
 203         map_binding.object = state->iface->syntax_id;
 204         map_binding.host = "";
 205         map_binding.endpoint = "";
 206
 207         map_tower = talloc_zero(tmp_ctx, struct epm_twr_t);
 208         if (map_tower == NULL) {
 209                 talloc_free(tmp_ctx);
 210                 talloc_free(state);
 211                 return;
 212         }
 213
 214         status = dcerpc_binding_build_tower(map_tower, &map_binding,
 215                                             &map_tower->tower);
 216         if (!NT_STATUS_IS_OK(status)) {
 217                 talloc_free(tmp_ctx);
 218                 talloc_free(state);
 219                 return;
 220         }
 221
 222         ok = false;
 223         status = dcerpc_epm_Map(state->h,
 224                                 tmp_ctx,
 225                                 &object,
 226                                 map_tower,
 227                                 &entry_handle,
 228                                 10,
 229                                 &num_towers,
 230                                 towers,
 231                                 &result);
 232         if (NT_STATUS_IS_OK(status)) {
 233                 ok = true;
 234         }
 235         if (result == EPMAPPER_STATUS_OK ||
 236             result == EPMAPPER_STATUS_NO_MORE_ENTRIES) {
 237                 ok = true;
 238         }
 239         if (num_towers == 0) {
 240                 ok = false;
 241         }
 242
 243         dcerpc_epm_LookupHandleFree(state->h,
 244                                     tmp_ctx,
 245                                     &entry_handle,
 246                                     &result);
 247         talloc_free(tmp_ctx);
 248
 249         subreq = tevent_wakeup_send(state,
 250                                     state->ev_ctx,
 251                                     timeval_current_ofs(MONITOR_WAIT_TIME, 0));
 252         if (subreq == NULL) {
 253                 talloc_free(state);
 254                 return;
 255         }
 256
 257         if (ok) {
 258                 tevent_req_set_callback(subreq, rpc_ep_monitor_loop, state);
 259         } else {
 260                 TALLOC_FREE(state->h);
 261                 state->wait_time = 1;
 262
 263                 tevent_req_set_callback(subreq, rpc_ep_register_loop, state);
 264         }
 265
 266         return;
 267 }