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