source4/ntvfs/sysdep/sys_lease.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    Copyright (C) Stefan Metzmacher 2008
   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 leases (oplocks) into a
  22   single Samba friendly interface
  23 */
  24
  25 #include "includes.h"
  26 #include "system/filesys.h"
  27 #include "ntvfs/sysdep/sys_lease.h"
  28 #include "../lib/util/dlinklist.h"
  29 #include "param/param.h"
  30 #include "lib/util/samba_modules.h"
  31
  32 /* list of registered backends */
  33 static struct sys_lease_ops *backends;
  34 static uint32_t num_backends;
  35
  36 #define LEASE_BACKEND   "lease:backend"
  37
  38 /*
  39   initialise a system change notify backend
  40 */
  41 _PUBLIC_ struct sys_lease_context *sys_lease_context_create(struct share_config *scfg,
  42                                                             TALLOC_CTX *mem_ctx,
  43                                                             struct tevent_context *ev,
  44                                                             struct imessaging_context *msg,
  45                                                             sys_lease_send_break_fn break_send)
  46 {
  47         struct sys_lease_context *ctx;
  48         const char *bname;
  49         int i;
  50         NTSTATUS status;
  51         TALLOC_CTX * tmp_ctx;
  52
  53         if (num_backends == 0) {
  54                 return NULL;
  55         }
  56
  57         if (ev == NULL) {
  58                 return NULL;
  59         }
  60
  61         ctx = talloc_zero(mem_ctx, struct sys_lease_context);
  62         if (ctx == NULL) {
  63                 return NULL;
  64         }
  65
  66         tmp_ctx = talloc_new(ctx);
  67         if (tmp_ctx == NULL) {
  68                 return NULL;
  69         }
  70
  71         ctx->event_ctx = ev;
  72         ctx->msg_ctx = msg;
  73         ctx->break_send = break_send;
  74
  75         bname = share_string_option(tmp_ctx, scfg, LEASE_BACKEND, NULL);
  76         if (!bname) {
  77                 talloc_free(ctx);
  78                 return NULL;
  79         }
  80
  81         for (i=0;i<num_backends;i++) {
  82                 if (strcasecmp(backends[i].name, bname) == 0) {
  83                         ctx->ops = &backends[i];
  84                         break;
  85                 }
  86         }
  87
  88         if (!ctx->ops) {
  89                 talloc_free(ctx);
  90                 return NULL;
  91         }
  92
  93         status = ctx->ops->init(ctx);
  94         if (!NT_STATUS_IS_OK(status)) {
  95                 talloc_free(ctx);
  96                 return NULL;
  97         }
  98
  99         TALLOC_FREE(tmp_ctx);
 100         return ctx;
 101 }
 102
 103 /*
 104   register a lease backend
 105 */
 106 _PUBLIC_ NTSTATUS sys_lease_register(const struct sys_lease_ops *backend)
 107 {
 108         struct sys_lease_ops *b;
 109         b = talloc_realloc(talloc_autofree_context(), backends,
 110                            struct sys_lease_ops, num_backends+1);
 111         NT_STATUS_HAVE_NO_MEMORY(b);
 112         backends = b;
 113         backends[num_backends] = *backend;
 114         num_backends++;
 115         return NT_STATUS_OK;
 116 }
 117
 118 _PUBLIC_ NTSTATUS sys_lease_init(void)
 119 {
 120         static bool initialized = false;
 121 #define _MODULE_PROTO(init) extern NTSTATUS init(void);
 122         STATIC_sys_lease_MODULES_PROTO;
 123         init_module_fn static_init[] = { STATIC_sys_lease_MODULES };
 124
 125         if (initialized) return NT_STATUS_OK;
 126         initialized = true;
 127
 128         run_init_functions(static_init);
 129
 130         return NT_STATUS_OK;
 131 }
 132
 133 NTSTATUS sys_lease_setup(struct sys_lease_context *ctx,
 134                          struct opendb_entry *e)
 135 {
 136         return ctx->ops->setup(ctx, e);
 137 }
 138
 139 NTSTATUS sys_lease_update(struct sys_lease_context *ctx,
 140                           struct opendb_entry *e)
 141 {
 142         return ctx->ops->update(ctx, e);
 143 }
 144
 145 NTSTATUS sys_lease_remove(struct sys_lease_context *ctx,
 146                           struct opendb_entry *e)
 147 {
 148         return ctx->ops->remove(ctx, e);
 149 }