Line data    Source code

       1             : /* 
       2             :    Unix SMB/CIFS implementation.
       3             : 
       4             :    Copyright (C) Andrew Tridgell 2006
       5             :    
       6             :    This program is free software; you can redistribute it and/or modify
       7             :    it under the terms of the GNU General Public License as published by
       8             :    the Free Software Foundation; either version 3 of the License, or
       9             :    (at your option) any later version.
      10             :    
      11             :    This program is distributed in the hope that it will be useful,
      12             :    but WITHOUT ANY WARRANTY; without even the implied warranty of
      13             :    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      14             :    GNU General Public License for more details.
      15             :    
      16             :    You should have received a copy of the GNU General Public License
      17             :    along with this program.  If not, see <http://www.gnu.org/licenses/>.
      18             : */
      19             : 
      20             : /*
      21             :   abstract the various kernel interfaces to change notify into a
      22             :   single Samba friendly interface
      23             : */
      24             : 
      25             : #include "includes.h"
      26             : #include "system/filesys.h"
      27             : #include "ntvfs/sysdep/sys_notify.h"
      28             : #include <tevent.h>
      29             : #include "../lib/util/dlinklist.h"
      30             : #include "param/param.h"
      31             : #include "lib/util/samba_modules.h"
      32             : 
      33             : #undef strcasecmp
      34             : 
      35             : /* list of registered backends */
      36             : static struct sys_notify_backend *backends;
      37             : static uint32_t num_backends;
      38             : 
      39             : #define NOTIFY_BACKEND  "notify:backend"
      40             : 
      41             : /*
      42             :   initialise a system change notify backend
      43             : */
      44        1321 : _PUBLIC_ struct sys_notify_context *sys_notify_context_create(struct share_config *scfg,
      45             :                                                               TALLOC_CTX *mem_ctx, 
      46             :                                                               struct tevent_context *ev)
      47             : {
      48             :         struct sys_notify_context *ctx;
      49             :         const char *bname;
      50             :         int i;
      51             : 
      52        1321 :         if (num_backends == 0) {
      53           0 :                 return NULL;
      54             :         }
      55             : 
      56        1321 :         if (ev == NULL) {
      57           0 :                 return NULL;
      58             :         }
      59             : 
      60        1321 :         ctx = talloc_zero(mem_ctx, struct sys_notify_context);
      61        1321 :         if (ctx == NULL) {
      62           0 :                 return NULL;
      63             :         }
      64             : 
      65        1321 :         ctx->ev = ev;
      66             : 
      67        1321 :         bname = share_string_option(ctx, scfg, NOTIFY_BACKEND, NULL);
      68        1321 :         if (!bname) {
      69        1321 :                 if (num_backends) {
      70        1321 :                         bname = backends[0].name;
      71             :                 } else {
      72           0 :                         bname = "__unknown__";
      73             :                 }
      74             :         }
      75             : 
      76        2642 :         for (i=0;i<num_backends;i++) {
      77             :                 char *enable_opt_name;
      78             :                 bool enabled;
      79             :                 
      80        1321 :                 enable_opt_name = talloc_asprintf(mem_ctx, "notify:%s", 
      81        1321 :                                                                                   backends[i].name);
      82        1321 :                 enabled = share_bool_option(scfg, enable_opt_name, true);
      83        1321 :                 talloc_free(enable_opt_name);
      84             : 
      85        1321 :                 if (!enabled) 
      86        1321 :                         continue;
      87             : 
      88           0 :                 if (strcasecmp(backends[i].name, bname) == 0) {
      89           0 :                         bname = backends[i].name;
      90           0 :                         break;
      91             :                 }
      92             :         }
      93             : 
      94        1321 :         ctx->name = bname;
      95        1321 :         ctx->notify_watch = NULL;
      96             : 
      97        1321 :         if (i < num_backends) {
      98           0 :                 ctx->notify_watch = backends[i].notify_watch;
      99             :         }
     100             : 
     101        1321 :         return ctx;
     102             : }
     103             : 
     104             : /*
     105             :   add a watch
     106             : 
     107             :   note that this call must modify the e->filter and e->subdir_filter
     108             :   bits to remove ones handled by this backend. Any remaining bits will
     109             :   be handled by the generic notify layer
     110             : */
     111         513 : _PUBLIC_ NTSTATUS sys_notify_watch(struct sys_notify_context *ctx,
     112             :                                    struct notify_entry *e,
     113             :                                    sys_notify_callback_t callback,
     114             :                                    void *private_data, void *handle)
     115             : {
     116         513 :         if (!ctx->notify_watch) {
     117         513 :                 return NT_STATUS_INVALID_SYSTEM_SERVICE;
     118             :         }
     119           0 :         return ctx->notify_watch(ctx, e, callback, private_data, handle);
     120             : }
     121             : 
     122             : /*
     123             :   register a notify backend
     124             : */
     125          55 : _PUBLIC_ NTSTATUS sys_notify_register(TALLOC_CTX *ctx,
     126             :                         struct sys_notify_backend *backend)
     127             : {
     128             :         struct sys_notify_backend *b;
     129          55 :         b = talloc_realloc(ctx, backends,
     130             :                            struct sys_notify_backend, num_backends+1);
     131          55 :         NT_STATUS_HAVE_NO_MEMORY(b);
     132          55 :         backends = b;
     133          55 :         backends[num_backends] = *backend;
     134          55 :         num_backends++;
     135          55 :         return NT_STATUS_OK;
     136             : }
     137             : 
     138          55 : _PUBLIC_ NTSTATUS sys_notify_init(void)
     139             : {
     140             :         static bool initialized = false;
     141             : #define _MODULE_PROTO(init) extern NTSTATUS init(TALLOC_CTX *);
     142             :         STATIC_sys_notify_MODULES_PROTO;
     143          55 :         init_module_fn static_init[] = { STATIC_sys_notify_MODULES };
     144             : 
     145          55 :         if (initialized) return NT_STATUS_OK;
     146          55 :         initialized = true;
     147             : 
     148          55 :         run_init_functions(NULL, static_init);
     149             :         
     150          55 :         return NT_STATUS_OK;
     151             : }