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 #include "lib/util/samba_modules.h"
  30
  31 /* the list of currently registered NTVFS backends, note that there
  32  * can be more than one backend with the same name, as long as they
  33  * have different typesx */
  34 static struct ntvfs_backend {
  35         const struct ntvfs_ops *ops;
  36 } *backends = NULL;
  37 static int num_backends;
  38
  39 /*
  40   register a NTVFS backend.
  41
  42   The 'name' can be later used by other backends to find the operations
  43   structure for this backend.
  44
  45   The 'type' is used to specify whether this is for a disk, printer or IPC$ share
  46 */
  47 NTSTATUS ntvfs_register(const struct ntvfs_ops *ops,
  48                                  const struct ntvfs_critical_sizes *const sizes)
  49 {
  50         struct ntvfs_ops *new_ops;
  51
  52         if (ntvfs_interface_differs(sizes)) {
  53                 DEBUG(0, ("NTVFS backend '%s' for type %d "
  54                           "failed version check\n",
  55                           ops->name, (int)ops->type));
  56                 return NT_STATUS_BAD_FUNCTION_TABLE;
  57         }
  58
  59         if (ntvfs_backend_byname(ops->name, ops->type) != NULL) {
  60                 /* its already registered! */
  61                 DEBUG(0,("NTVFS backend '%s' for type %d already registered\n",
  62                          ops->name, (int)ops->type));
  63                 return NT_STATUS_OBJECT_NAME_COLLISION;
  64         }
  65
  66         backends = realloc_p(backends, struct ntvfs_backend, num_backends+1);
  67         if (!backends) {
  68                 smb_panic("out of memory in ntvfs_register");
  69         }
  70
  71         new_ops = smb_xmemdup(ops, sizeof(*ops));
  72         new_ops->name = smb_xstrdup(ops->name);
  73
  74         backends[num_backends].ops = new_ops;
  75
  76         num_backends++;
  77
  78         DEBUG(3,("NTVFS backend '%s' for type %d registered\n",
  79                  ops->name,ops->type));
  80
  81         return NT_STATUS_OK;
  82 }
  83
  84
  85 /*
  86   return the operations structure for a named backend of the specified type
  87 */
  88 const struct ntvfs_ops *ntvfs_backend_byname(const char *name, enum ntvfs_type type)
  89 {
  90         int i;
  91
  92         for (i=0;i<num_backends;i++) {
  93                 if (backends[i].ops->type == type &&
  94                     strcmp(backends[i].ops->name, name) == 0) {
  95                         return backends[i].ops;
  96                 }
  97         }
  98
  99         return NULL;
 100 }
 101
 102
 103 /*
 104   return the NTVFS interface version, and the size of some critical types
 105   This can be used by backends to either detect compilation errors, or provide
 106   multiple implementations for different smbd compilation options in one module
 107 */
 108
 109 static const NTVFS_CURRENT_CRITICAL_SIZES(critical_sizes);
 110
 111 const struct ntvfs_critical_sizes *ntvfs_interface_version(void)
 112 {
 113         return &critical_sizes;
 114 }
 115
 116 bool ntvfs_interface_differs(const struct ntvfs_critical_sizes *const iface)
 117 {
 118         /* The comparison would be easier with memcmp, but compiler-interset
 119          * alignment padding is not guaranteed to be zeroed.
 120          */
 121
 122 #define FIELD_DIFFERS(field) (iface->field != critical_sizes.field)
 123
 124         if (FIELD_DIFFERS(interface_version))
 125                 return true;
 126
 127         if (FIELD_DIFFERS(sizeof_ntvfs_critical_sizes))
 128                 return true;
 129
 130         if (FIELD_DIFFERS(sizeof_ntvfs_context))
 131                 return true;
 132
 133         if (FIELD_DIFFERS(sizeof_ntvfs_module_context))
 134                 return true;
 135
 136         if (FIELD_DIFFERS(sizeof_ntvfs_ops))
 137                 return true;
 138
 139         if (FIELD_DIFFERS(sizeof_ntvfs_async_state))
 140                 return true;
 141
 142         if (FIELD_DIFFERS(sizeof_ntvfs_request))
 143                 return true;
 144
 145         /* Versions match. */
 146         return false;
 147
 148 #undef FIELD_DIFFERS
 149 }
 150
 151 /*
 152   initialise a connection structure to point at a NTVFS backend
 153 */
 154 NTSTATUS ntvfs_init_connection(TALLOC_CTX *mem_ctx, struct share_config *scfg, enum ntvfs_type type,
 155                                enum protocol_types protocol,
 156                                uint64_t ntvfs_client_caps,
 157                                struct tevent_context *ev, struct imessaging_context *msg,
 158                                struct loadparm_context *lp_ctx,
 159                                struct server_id server_id, struct ntvfs_context **_ctx)
 160 {
 161         const char **handlers = share_string_list_option(mem_ctx, scfg, SHARE_NTVFS_HANDLER);
 162         int i;
 163         struct ntvfs_context *ctx;
 164
 165         if (!handlers) {
 166                 return NT_STATUS_INTERNAL_ERROR;
 167         }
 168
 169         ctx = talloc_zero(mem_ctx, struct ntvfs_context);
 170         NT_STATUS_HAVE_NO_MEMORY(ctx);
 171         ctx->protocol           = protocol;
 172         ctx->client_caps        = ntvfs_client_caps;
 173         ctx->type               = type;
 174         ctx->config             = talloc_steal(ctx, scfg);
 175         ctx->event_ctx          = ev;
 176         ctx->msg_ctx            = msg;
 177         ctx->server_id          = server_id;
 178         ctx->lp_ctx             = lp_ctx;
 179
 180         for (i=0; handlers[i]; i++) {
 181                 struct ntvfs_module_context *ntvfs;
 182
 183                 ntvfs = talloc_zero(ctx, struct ntvfs_module_context);
 184                 NT_STATUS_HAVE_NO_MEMORY(ntvfs);
 185                 ntvfs->ctx = ctx;
 186                 ntvfs->ops = ntvfs_backend_byname(handlers[i], ctx->type);
 187                 if (!ntvfs->ops) {
 188                         DEBUG(1,("ntvfs_init_connection: failed to find backend=%s, type=%d\n",
 189                                 handlers[i], ctx->type));
 190                         return NT_STATUS_INTERNAL_ERROR;
 191                 }
 192                 ntvfs->depth = i;
 193                 DLIST_ADD_END(ctx->modules, ntvfs, struct ntvfs_module_context *);
 194         }
 195
 196         if (!ctx->modules) {
 197                 return NT_STATUS_INTERNAL_ERROR;
 198         }
 199
 200         *_ctx = ctx;
 201         return NT_STATUS_OK;
 202 }
 203
 204 /*
 205   adds the IPC$ share, needed for RPC calls
 206  */
 207 static NTSTATUS ntvfs_add_ipc_share(struct loadparm_context *lp_ctx)
 208 {
 209         struct loadparm_service *ipc;
 210
 211         if (lpcfg_service(lp_ctx, "IPC$")) {
 212                 /* it has already been defined in smb.conf or elsewhere */
 213                 return NT_STATUS_OK;
 214         }
 215
 216         ipc = lpcfg_add_service(lp_ctx, NULL, "IPC$");
 217         NT_STATUS_HAVE_NO_MEMORY(ipc);
 218
 219         lpcfg_do_service_parameter(lp_ctx, ipc, "comment", "IPC Service");
 220         lpcfg_do_service_parameter(lp_ctx, ipc, "path", "/dev/null");
 221         lpcfg_do_service_parameter(lp_ctx, ipc, "ntvfs handler", "default");
 222         lpcfg_do_service_parameter(lp_ctx, ipc, "browseable", "No");
 223         lpcfg_do_service_parameter(lp_ctx, ipc, "fstype", "IPC");
 224
 225         return NT_STATUS_OK;
 226 }
 227
 228 NTSTATUS ntvfs_init(struct loadparm_context *lp_ctx)
 229 {
 230         static bool initialized = false;
 231 #define _MODULE_PROTO(init) extern NTSTATUS init(void);
 232         STATIC_ntvfs_MODULES_PROTO;
 233         init_module_fn static_init[] = { STATIC_ntvfs_MODULES };
 234         init_module_fn *shared_init;
 235
 236         if (initialized) return NT_STATUS_OK;
 237         initialized = true;
 238
 239         shared_init = load_samba_modules(NULL, "ntvfs");
 240
 241         run_init_functions(static_init);
 242         run_init_functions(shared_init);
 243
 244         talloc_free(shared_init);
 245
 246         ntvfs_add_ipc_share(lp_ctx);
 247
 248         return NT_STATUS_OK;
 249 }