source4/nbt_server/wins/winsclient.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    wins client name registration and refresh
   5
   6    Copyright (C) Andrew Tridgell        2005
   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 "nbt_server/nbt_server.h"
  24 #include "nbt_server/wins/winsserver.h"
  25 #include "libcli/composite/composite.h"
  26 #include "lib/events/events.h"
  27 #include "librpc/gen_ndr/ndr_nbt.h"
  28 #include "smbd/service_task.h"
  29 #include "param/param.h"
  30
  31 /* we send WINS client requests using our primary network interface
  32 */
  33 static struct nbt_name_socket *wins_socket(struct nbtd_interface *iface)
  34 {
  35         struct nbtd_server *nbtsrv = iface->nbtsrv;
  36         return nbtsrv->interfaces->nbtsock;
  37 }
  38
  39
  40 static void nbtd_wins_refresh(struct tevent_context *ev, struct tevent_timer *te,
  41                               struct timeval t, void *private_data);
  42
  43 /*
  44   retry a WINS name registration
  45 */
  46 static void nbtd_wins_register_retry(struct tevent_context *ev, struct tevent_timer *te,
  47                                      struct timeval t, void *private_data)
  48 {
  49         struct nbtd_iface_name *iname = talloc_get_type(private_data, struct nbtd_iface_name);
  50         nbtd_winsclient_register(iname);
  51 }
  52
  53 /*
  54   start a timer to refresh this name
  55 */
  56 static void nbtd_wins_start_refresh_timer(struct nbtd_iface_name *iname)
  57 {
  58         uint32_t refresh_time;
  59         uint32_t max_refresh_time = lpcfg_parm_int(iname->iface->nbtsrv->task->lp_ctx, NULL, "nbtd", "max_refresh_time", 7200);
  60
  61         refresh_time = MIN(max_refresh_time, iname->ttl/2);
  62
  63         tevent_add_timer(iname->iface->nbtsrv->task->event_ctx,
  64                         iname,
  65                         timeval_add(&iname->registration_time, refresh_time, 0),
  66                         nbtd_wins_refresh, iname);
  67 }
  68
  69 struct nbtd_wins_refresh_state {
  70         struct nbtd_iface_name *iname;
  71         struct nbt_name_refresh_wins io;
  72 };
  73
  74 /*
  75   called when a wins name refresh has completed
  76 */
  77 static void nbtd_wins_refresh_handler(struct tevent_req *subreq)
  78 {
  79         NTSTATUS status;
  80         struct nbtd_wins_refresh_state *state =
  81                 tevent_req_callback_data(subreq,
  82                 struct nbtd_wins_refresh_state);
  83         struct nbtd_iface_name *iname = state->iname;
  84
  85         status = nbt_name_refresh_wins_recv(subreq, state, &state->io);
  86         TALLOC_FREE(subreq);
  87         if (NT_STATUS_EQUAL(status, NT_STATUS_IO_TIMEOUT)) {
  88                 /* our WINS server is dead - start registration over
  89                    from scratch */
  90                 DEBUG(2,("Failed to refresh %s with WINS server %s\n",
  91                          nbt_name_string(state, &iname->name), iname->wins_server));
  92                 talloc_free(state);
  93                 nbtd_winsclient_register(iname);
  94                 return;
  95         }
  96
  97         if (!NT_STATUS_IS_OK(status)) {
  98                 DEBUG(1,("Name refresh failure with WINS for %s - %s\n",
  99                          nbt_name_string(state, &iname->name), nt_errstr(status)));
 100                 talloc_free(state);
 101                 return;
 102         }
 103
 104         if (state->io.out.rcode != 0) {
 105                 DEBUG(1,("WINS server %s rejected name refresh of %s - %s\n",
 106                          state->io.out.wins_server,
 107                          nbt_name_string(state, &iname->name),
 108                          nt_errstr(nbt_rcode_to_ntstatus(state->io.out.rcode))));
 109                 iname->nb_flags |= NBT_NM_CONFLICT;
 110                 talloc_free(state);
 111                 return;
 112         }
 113
 114         DEBUG(4,("Refreshed name %s with WINS server %s\n",
 115                  nbt_name_string(state, &iname->name), iname->wins_server));
 116         /* success - start a periodic name refresh */
 117         iname->nb_flags |= NBT_NM_ACTIVE;
 118         if (iname->wins_server) {
 119                 /*
 120                  * talloc_free() would generate a warning,
 121                  * so steal it into the tmp context
 122                  */
 123                 talloc_steal(state, iname->wins_server);
 124         }
 125         iname->wins_server = talloc_move(iname, &state->io.out.wins_server);
 126         iname->registration_time = timeval_current();
 127
 128         talloc_free(state);
 129
 130         nbtd_wins_start_refresh_timer(iname);
 131 }
 132
 133
 134 /*
 135   refresh a WINS name registration
 136 */
 137 static void nbtd_wins_refresh(struct tevent_context *ev, struct tevent_timer *te,
 138                               struct timeval t, void *private_data)
 139 {
 140         struct nbtd_iface_name *iname = talloc_get_type(private_data, struct nbtd_iface_name);
 141         struct nbtd_interface *iface = iname->iface;
 142         struct nbt_name_socket *nbtsock = wins_socket(iface);
 143         struct tevent_req *subreq;
 144         struct nbtd_wins_refresh_state *state;
 145         char **l;
 146
 147         state = talloc_zero(iname, struct nbtd_wins_refresh_state);
 148         if (state == NULL) {
 149                 return;
 150         }
 151
 152         state->iname = iname;
 153
 154         /* setup a wins name refresh request */
 155         state->io.in.name            = iname->name;
 156         l = str_list_make_single(state, iname->wins_server);
 157         state->io.in.wins_servers    = discard_const_p(const char *, l);
 158         state->io.in.wins_port       = lpcfg_nbt_port(iface->nbtsrv->task->lp_ctx);
 159         state->io.in.addresses       = nbtd_address_list(iface, state);
 160         state->io.in.nb_flags        = iname->nb_flags;
 161         state->io.in.ttl             = iname->ttl;
 162
 163         if (!state->io.in.addresses) {
 164                 talloc_free(state);
 165                 return;
 166         }
 167
 168         subreq = nbt_name_refresh_wins_send(state, ev, nbtsock, &state->io);
 169         if (subreq == NULL) {
 170                 talloc_free(state);
 171                 return;
 172         }
 173
 174         tevent_req_set_callback(subreq, nbtd_wins_refresh_handler, state);
 175 }
 176
 177 struct nbtd_wins_register_state {
 178         struct nbtd_iface_name *iname;
 179         struct nbt_name_register_wins io;
 180 };
 181
 182 /*
 183   called when a wins name register has completed
 184 */
 185 static void nbtd_wins_register_handler(struct tevent_req *subreq)
 186 {
 187         NTSTATUS status;
 188         struct nbtd_wins_register_state *state =
 189                 tevent_req_callback_data(subreq,
 190                 struct nbtd_wins_register_state);
 191         struct nbtd_iface_name *iname = state->iname;
 192
 193         status = nbt_name_register_wins_recv(subreq, state, &state->io);
 194         TALLOC_FREE(subreq);
 195         if (NT_STATUS_EQUAL(status, NT_STATUS_IO_TIMEOUT)) {
 196                 /* none of the WINS servers responded - try again
 197                    periodically */
 198                 int wins_retry_time = lpcfg_parm_int(iname->iface->nbtsrv->task->lp_ctx, NULL, "nbtd", "wins_retry", 300);
 199                 tevent_add_timer(iname->iface->nbtsrv->task->event_ctx,
 200                                 iname,
 201                                 timeval_current_ofs(wins_retry_time, 0),
 202                                 nbtd_wins_register_retry,
 203                                 iname);
 204                 talloc_free(state);
 205                 return;
 206         }
 207
 208         if (!NT_STATUS_IS_OK(status)) {
 209                 DEBUG(1,("Name register failure with WINS for %s - %s\n",
 210                          nbt_name_string(state, &iname->name), nt_errstr(status)));
 211                 talloc_free(state);
 212                 return;
 213         }
 214
 215         if (state->io.out.rcode != 0) {
 216                 DEBUG(1,("WINS server %s rejected name register of %s - %s\n",
 217                          state->io.out.wins_server,
 218                          nbt_name_string(state, &iname->name),
 219                          nt_errstr(nbt_rcode_to_ntstatus(state->io.out.rcode))));
 220                 iname->nb_flags |= NBT_NM_CONFLICT;
 221                 talloc_free(state);
 222                 return;
 223         }
 224
 225         /* success - start a periodic name refresh */
 226         iname->nb_flags |= NBT_NM_ACTIVE;
 227         if (iname->wins_server) {
 228                 /*
 229                  * talloc_free() would generate a warning,
 230                  * so steal it into the tmp context
 231                  */
 232                 talloc_steal(state, iname->wins_server);
 233         }
 234         iname->wins_server = talloc_move(iname, &state->io.out.wins_server);
 235
 236         iname->registration_time = timeval_current();
 237
 238         DEBUG(3,("Registered %s with WINS server %s\n",
 239                  nbt_name_string(state, &iname->name), iname->wins_server));
 240
 241         talloc_free(state);
 242
 243         nbtd_wins_start_refresh_timer(iname);
 244 }
 245
 246 /*
 247   register a name with our WINS servers
 248 */
 249 void nbtd_winsclient_register(struct nbtd_iface_name *iname)
 250 {
 251         struct nbtd_interface *iface = iname->iface;
 252         struct nbt_name_socket *nbtsock = wins_socket(iface);
 253         struct nbtd_wins_register_state *state;
 254         struct tevent_req *subreq;
 255
 256         state = talloc_zero(iname, struct nbtd_wins_register_state);
 257         if (state == NULL) {
 258                 return;
 259         }
 260
 261         state->iname = iname;
 262
 263         /* setup a wins name register request */
 264         state->io.in.name         = iname->name;
 265         state->io.in.wins_port    = lpcfg_nbt_port(iface->nbtsrv->task->lp_ctx);
 266         state->io.in.wins_servers = lpcfg_wins_server_list(iface->nbtsrv->task->lp_ctx);
 267         state->io.in.addresses    = nbtd_address_list(iface, state);
 268         state->io.in.nb_flags     = iname->nb_flags;
 269         state->io.in.ttl          = iname->ttl;
 270
 271         if (state->io.in.addresses == NULL) {
 272                 talloc_free(state);
 273                 return;
 274         }
 275
 276         subreq = nbt_name_register_wins_send(state, iface->nbtsrv->task->event_ctx,
 277                                              nbtsock, &state->io);
 278         if (subreq == NULL) {
 279                 talloc_free(state);
 280                 return;
 281         }
 282
 283         tevent_req_set_callback(subreq, nbtd_wins_register_handler, state);
 284 }