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 */
33static struct ntvfs_backend {
34	const struct ntvfs_ops *ops;
35} *backends = NULL;
36static 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*/
46NTSTATUS 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*/
87const 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
108static const NTVFS_CURRENT_CRITICAL_SIZES(critical_sizes);
109
110const struct ntvfs_critical_sizes *ntvfs_interface_version(void)
111{
112	return &critical_sizes;
113}
114
115bool 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*/
153NTSTATUS 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
203NTSTATUS ntvfs_init(struct loadparm_context *lp_ctx)
204{
205	static bool initialized = false;
206	extern NTSTATUS ntvfs_posix_init(void);
207	extern NTSTATUS ntvfs_cifs_init(void);
208	extern NTSTATUS ntvfs_smb2_init(void);
209	extern NTSTATUS ntvfs_nbench_init(void);
210	extern NTSTATUS ntvfs_unixuid_init(void);
211	extern NTSTATUS ntvfs_ipc_init(void);
212	extern NTSTATUS ntvfs_print_init(void);
213	extern NTSTATUS ntvfs_simple_init(void);
214	extern NTSTATUS ntvfs_cifs_posix_init(void);
215	init_module_fn static_init[] = { STATIC_ntvfs_MODULES };
216	init_module_fn *shared_init;
217
218	if (initialized) return NT_STATUS_OK;
219	initialized = true;
220
221	shared_init = load_samba_modules(NULL, lp_ctx, "ntvfs");
222
223	run_init_functions(static_init);
224	run_init_functions(shared_init);
225
226	talloc_free(shared_init);
227
228	return NT_STATUS_OK;
229}
230