summaryrefslogtreecommitdiff
path: root/source3/smbd/conn.c
blob: 1344bac7a801614cb0a592fcadf19b775fdf2413 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
/*
   Unix SMB/CIFS implementation.
   Manage connections_struct structures
   Copyright (C) Andrew Tridgell 1998
   Copyright (C) Alexander Bokovoy 2002
   Copyright (C) Jeremy Allison 2010

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "includes.h"
#include "smbd/smbd.h"
#include "smbd/globals.h"
#include "lib/util/bitmap.h"

/* The connections bitmap is expanded in increments of BITMAP_BLOCK_SZ. The
 * maximum size of the bitmap is the largest positive integer, but you will hit
 * the "max connections" limit, looong before that.
 */

#define BITMAP_BLOCK_SZ 128

/****************************************************************************
 Init the conn structures.
****************************************************************************/

void conn_init(struct smbd_server_connection *sconn)
{
	sconn->smb1.tcons.bmap = bitmap_talloc(sconn, BITMAP_BLOCK_SZ);
}

/****************************************************************************
 Return the number of open connections.
****************************************************************************/

int conn_num_open(struct smbd_server_connection *sconn)
{
	return sconn->num_connections;
}

/****************************************************************************
 Check if a snum is in use.
****************************************************************************/

bool conn_snum_used(struct smbd_server_connection *sconn,
		    int snum)
{
	struct connection_struct *conn;

	for (conn=sconn->connections; conn; conn=conn->next) {
		if (conn->params->service == snum) {
			return true;
		}
	}

	return false;
}

/****************************************************************************
 Find a conn given a cnum.
****************************************************************************/

connection_struct *conn_find(struct smbd_server_connection *sconn,unsigned cnum)
{
	size_t count=0;
	struct connection_struct *conn;

	for (conn=sconn->connections; conn; conn=conn->next,count++) {
		if (conn->cnum == cnum) {
			if (count > 10) {
				DLIST_PROMOTE(sconn->connections, conn);
			}
			return conn;
		}
	}

	return NULL;
}

/****************************************************************************
 Find first available connection slot, starting from a random position.
 The randomisation stops problems with the server dieing and clients
 thinking the server is still available.
****************************************************************************/

connection_struct *conn_new(struct smbd_server_connection *sconn)
{
	connection_struct *conn;
	int i;
        int find_offset = 1;

	if (sconn->using_smb2) {
		/* SMB2 */
		if (!(conn=talloc_zero(NULL, connection_struct)) ||
		    !(conn->params = talloc(conn, struct share_params))) {
			DEBUG(0,("TALLOC_ZERO() failed!\n"));
			TALLOC_FREE(conn);
			return NULL;
		}
		conn->sconn = sconn;

		DLIST_ADD(sconn->connections, conn);
		sconn->num_connections++;

		return conn;
	}

	/* SMB1 */
find_again:
	i = bitmap_find(sconn->smb1.tcons.bmap, find_offset);

	if (i == -1) {
                /* Expand the connections bitmap. */
                int             oldsz = sconn->smb1.tcons.bmap->n;
                int             newsz = sconn->smb1.tcons.bmap->n +
					BITMAP_BLOCK_SZ;
                struct bitmap * nbmap;

                if (newsz <= oldsz) {
                        /* Integer wrap. */
		        DEBUG(0,("ERROR! Out of connection structures\n"));
                        return NULL;
                }

		DEBUG(4,("resizing connections bitmap from %d to %d\n",
                        oldsz, newsz));

                nbmap = bitmap_talloc(sconn, newsz);
		if (!nbmap) {
			DEBUG(0,("ERROR! malloc fail.\n"));
			return NULL;
		}

                bitmap_copy(nbmap, sconn->smb1.tcons.bmap);
		TALLOC_FREE(sconn->smb1.tcons.bmap);

                sconn->smb1.tcons.bmap = nbmap;
                find_offset = oldsz; /* Start next search in the new portion. */

                goto find_again;
	}

	/* The bitmap position is used below as the connection number
	 * conn->cnum). This ends up as the TID field in the SMB header,
	 * which is limited to 16 bits (we skip 0xffff which is the
	 * NULL TID).
	 */
	if (i > 65534) {
		DEBUG(0, ("Maximum connection limit reached\n"));
		return NULL;
	}

	if (!(conn=talloc_zero(NULL, connection_struct)) ||
	    !(conn->params = talloc(conn, struct share_params))) {
		DEBUG(0,("TALLOC_ZERO() failed!\n"));
		TALLOC_FREE(conn);
		return NULL;
	}
	conn->sconn = sconn;
	conn->cnum = i;
	conn->force_group_gid = (gid_t)-1;

	bitmap_set(sconn->smb1.tcons.bmap, i);

	string_set(&conn->connectpath,"");
	string_set(&conn->origpath,"");

	DLIST_ADD(sconn->connections, conn);
	sconn->num_connections++;

	return conn;
}

/****************************************************************************
 Clear a vuid out of the connection's vuid cache
****************************************************************************/

static void conn_clear_vuid_cache(connection_struct *conn, uint64_t vuid)
{
	int i;

	for (i=0; i<VUID_CACHE_SIZE; i++) {
		struct vuid_cache_entry *ent;

		ent = &conn->vuid_cache.array[i];

		if (ent->vuid == vuid) {
			ent->vuid = UID_FIELD_INVALID;
			/*
			 * We need to keep conn->session_info around
			 * if it's equal to ent->session_info as a SMBulogoff
			 * is often followed by a SMBtdis (with an invalid
			 * vuid). The debug code (or regular code in
			 * vfs_full_audit) wants to refer to the
			 * conn->session_info pointer to print debug
			 * statements. Theoretically this is a bug,
			 * as once the vuid is gone the session_info
			 * on the conn struct isn't valid any more,
			 * but there's enough code that assumes
			 * conn->session_info is never null that
			 * it's easier to hold onto the old pointer
			 * until we get a new sessionsetupX.
			 * As everything is hung off the
			 * conn pointer as a talloc context we're not
			 * leaking memory here. See bug #6315. JRA.
			 */
			if (conn->session_info == ent->session_info) {
				ent->session_info = NULL;
			} else {
				TALLOC_FREE(ent->session_info);
			}
			ent->read_only = False;
		}
	}
}

/****************************************************************************
 Clear a vuid out of the validity cache, and as the 'owner' of a connection.

 Called from invalidate_vuid()
****************************************************************************/

void conn_clear_vuid_caches(struct smbd_server_connection *sconn, uint64_t vuid)
{
	connection_struct *conn;

	for (conn=sconn->connections; conn;conn=conn->next) {
		if (conn->vuid == vuid) {
			conn->vuid = UID_FIELD_INVALID;
		}
		conn_clear_vuid_cache(conn, vuid);
	}
}

/****************************************************************************
 Free a conn structure - internal part.
****************************************************************************/

static void conn_free_internal(connection_struct *conn)
{
	vfs_handle_struct *handle = NULL, *thandle = NULL;
	struct trans_state *state = NULL;

	/* Free vfs_connection_struct */
	handle = conn->vfs_handles;
	while(handle) {
		thandle = handle->next;
		DLIST_REMOVE(conn->vfs_handles, handle);
		if (handle->free_data)
			handle->free_data(&handle->data);
		handle = thandle;
	}

	/* Free any pending transactions stored on this conn. */
	for (state = conn->pending_trans; state; state = state->next) {
		/* state->setup is a talloc child of state. */
		SAFE_FREE(state->param);
		SAFE_FREE(state->data);
	}

	free_namearray(conn->veto_list);
	free_namearray(conn->hide_list);
	free_namearray(conn->veto_oplock_list);
	free_namearray(conn->aio_write_behind_list);

	string_free(&conn->connectpath);
	string_free(&conn->origpath);

	ZERO_STRUCTP(conn);
	talloc_destroy(conn);
}

/****************************************************************************
 Free a conn structure.
****************************************************************************/

void conn_free(connection_struct *conn)
{
	if (conn->sconn == NULL) {
		conn_free_internal(conn);
		return;
	}

	if (!conn->sconn->using_smb2 &&
	    conn->sconn->smb1.tcons.bmap != NULL) {
		/*
		 * Can be NULL for fake connections created by
		 * create_conn_struct()
		 */
		bitmap_clear(conn->sconn->smb1.tcons.bmap, conn->cnum);
	}

	DLIST_REMOVE(conn->sconn->connections, conn);
	SMB_ASSERT(conn->sconn->num_connections > 0);
	conn->sconn->num_connections--;

	conn_free_internal(conn);
}