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         event_add_timed(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
 146         state = talloc_zero(iname, struct nbtd_wins_refresh_state);
 147         if (state == NULL) {
 148                 return;
 149         }
 150
 151         state->iname = iname;
 152
 153         /* setup a wins name refresh request */
 154         state->io.in.name            = iname->name;
 155         state->io.in.wins_servers    = (const char **)str_list_make_single(state, iname->wins_server);
 156         state->io.in.wins_port       = lpcfg_nbt_port(iface->nbtsrv->task->lp_ctx);
 157         state->io.in.addresses       = nbtd_address_list(iface, state);
 158         state->io.in.nb_flags        = iname->nb_flags;
 159         state->io.in.ttl             = iname->ttl;
 160
 161         if (!state->io.in.addresses) {
 162                 talloc_free(state);
 163                 return;
 164         }
 165
 166         subreq = nbt_name_refresh_wins_send(state, ev, nbtsock, &state->io);
 167         if (subreq == NULL) {
 168                 talloc_free(state);
 169                 return;
 170         }
 171
 172         tevent_req_set_callback(subreq, nbtd_wins_refresh_handler, state);
 173 }
 174
 175
 176 /*
 177   called when a wins name register has completed
 178 */
 179 static void nbtd_wins_register_handler(struct composite_context *c)
 180 {
 181         NTSTATUS status;
 182         struct nbt_name_register_wins io;
 183         struct nbtd_iface_name *iname = talloc_get_type(c->async.private_data,
 184                                                         struct nbtd_iface_name);
 185         TALLOC_CTX *tmp_ctx = talloc_new(iname);
 186
 187         status = nbt_name_register_wins_recv(c, tmp_ctx, &io);
 188         if (NT_STATUS_EQUAL(status, NT_STATUS_IO_TIMEOUT)) {
 189                 /* none of the WINS servers responded - try again
 190                    periodically */
 191                 int wins_retry_time = lpcfg_parm_int(iname->iface->nbtsrv->task->lp_ctx, NULL, "nbtd", "wins_retry", 300);
 192                 event_add_timed(iname->iface->nbtsrv->task->event_ctx,
 193                                 iname,
 194                                 timeval_current_ofs(wins_retry_time, 0),
 195                                 nbtd_wins_register_retry,
 196                                 iname);
 197                 talloc_free(tmp_ctx);
 198                 return;
 199         }
 200
 201         if (!NT_STATUS_IS_OK(status)) {
 202                 DEBUG(1,("Name register failure with WINS for %s - %s\n",
 203                          nbt_name_string(tmp_ctx, &iname->name), nt_errstr(status)));
 204                 talloc_free(tmp_ctx);
 205                 return;
 206         }
 207
 208         if (io.out.rcode != 0) {
 209                 DEBUG(1,("WINS server %s rejected name register of %s - %s\n",
 210                          io.out.wins_server, nbt_name_string(tmp_ctx, &iname->name),
 211                          nt_errstr(nbt_rcode_to_ntstatus(io.out.rcode))));
 212                 iname->nb_flags |= NBT_NM_CONFLICT;
 213                 talloc_free(tmp_ctx);
 214                 return;
 215         }
 216
 217         /* success - start a periodic name refresh */
 218         iname->nb_flags |= NBT_NM_ACTIVE;
 219         if (iname->wins_server) {
 220                 /*
 221                  * talloc_free() would generate a warning,
 222                  * so steal it into the tmp context
 223                  */
 224                 talloc_steal(tmp_ctx, iname->wins_server);
 225         }
 226         iname->wins_server = talloc_steal(iname, io.out.wins_server);
 227
 228         iname->registration_time = timeval_current();
 229         nbtd_wins_start_refresh_timer(iname);
 230
 231         DEBUG(3,("Registered %s with WINS server %s\n",
 232                  nbt_name_string(tmp_ctx, &iname->name), iname->wins_server));
 233
 234         talloc_free(tmp_ctx);
 235 }
 236
 237 /*
 238   register a name with our WINS servers
 239 */
 240 void nbtd_winsclient_register(struct nbtd_iface_name *iname)
 241 {
 242         struct nbtd_interface *iface = iname->iface;
 243         struct nbt_name_register_wins io;
 244         struct composite_context *c;
 245
 246         /* setup a wins name register request */
 247         io.in.name            = iname->name;
 248         io.in.wins_port       = lpcfg_nbt_port(iname->iface->nbtsrv->task->lp_ctx);
 249         io.in.wins_servers    = lpcfg_wins_server_list(iname->iface->nbtsrv->task->lp_ctx);
 250         io.in.addresses       = nbtd_address_list(iface, iname);
 251         io.in.nb_flags        = iname->nb_flags;
 252         io.in.ttl             = iname->ttl;
 253
 254         if (!io.in.addresses) {
 255                 return;
 256         }
 257
 258         c = nbt_name_register_wins_send(wins_socket(iface), &io);
 259         if (c == NULL) {
 260                 talloc_free(io.in.addresses);
 261                 return;
 262         }
 263         talloc_steal(c, io.in.addresses);
 264
 265         c->async.fn = nbtd_wins_register_handler;
 266         c->async.private_data = iname;
 267 }