source4/ntvfs/ntvfs_base.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    NTVFS base code
   4
   5    Copyright (C) Andrew Tridgell 2003
   6    Copyright (C) Stefan (metze) Metzmacher 2004
   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   this implements the core code for all NTVFS modules. Backends register themselves here.
  23 */
  24
  25 #include "includes.h"
  26 #include "../lib/util/dlinklist.h"
  27 #include "ntvfs/ntvfs.h"
  28 #include "param/param.h"
  29
  30 /* the list of currently registered NTVFS backends, note that there
  31  * can be more than one backend with the same name, as long as they
  32  * have different typesx */
  33 static struct ntvfs_backend {
  34         const struct ntvfs_ops *ops;
  35 } *backends = NULL;
  36 static int num_backends;
  37
  38 /*
  39   register a NTVFS backend.
  40
  41   The 'name' can be later used by other backends to find the operations
  42   structure for this backend.
  43
  44   The 'type' is used to specify whether this is for a disk, printer or IPC$ share
  45 */
  46 NTSTATUS ntvfs_register(const struct ntvfs_ops *ops,
  47                                  const struct ntvfs_critical_sizes *const sizes)
  48 {
  49         struct ntvfs_ops *new_ops;
  50
  51         if (ntvfs_interface_differs(sizes)) {
  52                 DEBUG(0, ("NTVFS backend '%s' for type %d "
  53                           "failed version check\n",
  54                           ops->name, (int)ops->type));
  55                 return NT_STATUS_BAD_FUNCTION_TABLE;
  56         }
  57
  58         if (ntvfs_backend_byname(ops->name, ops->type) != NULL) {
  59                 /* its already registered! */
  60                 DEBUG(0,("NTVFS backend '%s' for type %d already registered\n",
  61                          ops->name, (int)ops->type));
  62                 return NT_STATUS_OBJECT_NAME_COLLISION;
  63         }
  64
  65         backends = realloc_p(backends, struct ntvfs_backend, num_backends+1);
  66         if (!backends) {
  67                 smb_panic("out of memory in ntvfs_register");
  68         }
  69
  70         new_ops = smb_xmemdup(ops, sizeof(*ops));
  71         new_ops->name = smb_xstrdup(ops->name);
  72
  73         backends[num_backends].ops = new_ops;
  74
  75         num_backends++;
  76
  77         DEBUG(3,("NTVFS backend '%s' for type %d registered\n",
  78                  ops->name,ops->type));
  79
  80         return NT_STATUS_OK;
  81 }
  82
  83
  84 /*
  85   return the operations structure for a named backend of the specified type
  86 */
  87 const struct ntvfs_ops *ntvfs_backend_byname(const char *name, enum ntvfs_type type)
  88 {
  89         int i;
  90
  91         for (i=0;i<num_backends;i++) {
  92                 if (backends[i].ops->type == type &&
  93                     strcmp(backends[i].ops->name, name) == 0) {
  94                         return backends[i].ops;
  95                 }
  96         }
  97
  98         return NULL;
  99 }
 100
 101
 102 /*
 103   return the NTVFS interface version, and the size of some critical types
 104   This can be used by backends to either detect compilation errors, or provide
 105   multiple implementations for different smbd compilation options in one module
 106 */
 107
 108 static const NTVFS_CURRENT_CRITICAL_SIZES(critical_sizes);
 109
 110 const struct ntvfs_critical_sizes *ntvfs_interface_version(void)
 111 {
 112         return &critical_sizes;
 113 }
 114
 115 bool ntvfs_interface_differs(const struct ntvfs_critical_sizes *const iface)
 116 {
 117         /* The comparison would be easier with memcmp, but compiler-interset
 118          * alignment padding is not guaranteed to be zeroed.
 119          */
 120
 121 #define FIELD_DIFFERS(field) (iface->field != critical_sizes.field)
 122
 123         if (FIELD_DIFFERS(interface_version))
 124                 return true;
 125
 126         if (FIELD_DIFFERS(sizeof_ntvfs_critical_sizes))
 127                 return true;
 128
 129         if (FIELD_DIFFERS(sizeof_ntvfs_context))
 130                 return true;
 131
 132         if (FIELD_DIFFERS(sizeof_ntvfs_module_context))
 133                 return true;
 134
 135         if (FIELD_DIFFERS(sizeof_ntvfs_ops))
 136                 return true;
 137
 138         if (FIELD_DIFFERS(sizeof_ntvfs_async_state))
 139                 return true;
 140
 141         if (FIELD_DIFFERS(sizeof_ntvfs_request))
 142                 return true;
 143
 144         /* Versions match. */
 145         return false;
 146
 147 #undef FIELD_DIFFERS
 148 }
 149
 150 /*
 151   initialise a connection structure to point at a NTVFS backend
 152 */
 153 NTSTATUS ntvfs_init_connection(TALLOC_CTX *mem_ctx, struct share_config *scfg, enum ntvfs_type type,
 154                                enum protocol_types protocol,
 155                                uint64_t ntvfs_client_caps,
 156                                struct tevent_context *ev, struct messaging_context *msg,
 157                                struct loadparm_context *lp_ctx,
 158                                struct server_id server_id, struct ntvfs_context **_ctx)
 159 {
 160         const char **handlers = share_string_list_option(mem_ctx, scfg, SHARE_NTVFS_HANDLER);
 161         int i;
 162         struct ntvfs_context *ctx;
 163
 164         if (!handlers) {
 165                 return NT_STATUS_INTERNAL_ERROR;
 166         }
 167
 168         ctx = talloc_zero(mem_ctx, struct ntvfs_context);
 169         NT_STATUS_HAVE_NO_MEMORY(ctx);
 170         ctx->protocol           = protocol;
 171         ctx->client_caps        = ntvfs_client_caps;
 172         ctx->type               = type;
 173         ctx->config             = talloc_steal(ctx, scfg);
 174         ctx->event_ctx          = ev;
 175         ctx->msg_ctx            = msg;
 176         ctx->server_id          = server_id;
 177         ctx->lp_ctx             = lp_ctx;
 178
 179         for (i=0; handlers[i]; i++) {
 180                 struct ntvfs_module_context *ntvfs;
 181
 182                 ntvfs = talloc_zero(ctx, struct ntvfs_module_context);
 183                 NT_STATUS_HAVE_NO_MEMORY(ntvfs);
 184                 ntvfs->ctx = ctx;
 185                 ntvfs->ops = ntvfs_backend_byname(handlers[i], ctx->type);
 186                 if (!ntvfs->ops) {
 187                         DEBUG(1,("ntvfs_init_connection: failed to find backend=%s, type=%d\n",
 188                                 handlers[i], ctx->type));
 189                         return NT_STATUS_INTERNAL_ERROR;
 190                 }
 191                 ntvfs->depth = i;
 192                 DLIST_ADD_END(ctx->modules, ntvfs, struct ntvfs_module_context *);
 193         }
 194
 195         if (!ctx->modules) {
 196                 return NT_STATUS_INTERNAL_ERROR;
 197         }
 198
 199         *_ctx = ctx;
 200         return NT_STATUS_OK;
 201 }
 202
 203 /*
 204   adds the IPC$ share, needed for RPC calls
 205  */
 206 static NTSTATUS ntvfs_add_ipc_share(struct loadparm_context *lp_ctx)
 207 {
 208         struct loadparm_service *ipc;
 209
 210         if (lpcfg_service(lp_ctx, "IPC$")) {
 211                 /* it has already been defined in smb.conf or elsewhere */
 212                 return NT_STATUS_OK;
 213         }
 214
 215         ipc = lpcfg_add_service(lp_ctx, NULL, "IPC$");
 216         NT_STATUS_HAVE_NO_MEMORY(ipc);
 217
 218         lpcfg_do_service_parameter(lp_ctx, ipc, "comment", "IPC Service");
 219         lpcfg_do_service_parameter(lp_ctx, ipc, "path", "/dev/null");
 220         lpcfg_do_service_parameter(lp_ctx, ipc, "ntvfs handler", "default");
 221         lpcfg_do_service_parameter(lp_ctx, ipc, "browseable", "No");
 222         lpcfg_do_service_parameter(lp_ctx, ipc, "fstype", "IPC");
 223
 224         return NT_STATUS_OK;
 225 }
 226
 227 NTSTATUS ntvfs_init(struct loadparm_context *lp_ctx)
 228 {
 229         static bool initialized = false;
 230 #define _MODULE_PROTO(init) extern NTSTATUS init(void);
 231         STATIC_ntvfs_MODULES_PROTO;
 232         init_module_fn static_init[] = { STATIC_ntvfs_MODULES };
 233         init_module_fn *shared_init;
 234
 235         if (initialized) return NT_STATUS_OK;
 236         initialized = true;
 237
 238         shared_init = load_samba_modules(NULL, lp_ctx, "ntvfs");
 239
 240         run_init_functions(static_init);
 241         run_init_functions(shared_init);
 242
 243         talloc_free(shared_init);
 244
 245         ntvfs_add_ipc_share(lp_ctx);
 246
 247         return NT_STATUS_OK;
 248 }