8a96e880538efb67e1d02c3c049e2fdbf5e38198
[samba.git] / source3 / smbd / conn.c
1 /*
2    Unix SMB/CIFS implementation.
3    Manage connections_struct structures
4    Copyright (C) Andrew Tridgell 1998
5    Copyright (C) Alexander Bokovoy 2002
6    Copyright (C) Jeremy Allison 2010
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 #include "includes.h"
23 #include "smbd/smbd.h"
24 #include "smbd/globals.h"
25 #include "rpc_server/rpc_ncacn_np.h"
26
27 /* The connections bitmap is expanded in increments of BITMAP_BLOCK_SZ. The
28  * maximum size of the bitmap is the largest positive integer, but you will hit
29  * the "max connections" limit, looong before that.
30  */
31
32 #define BITMAP_BLOCK_SZ 128
33
34 /****************************************************************************
35  Init the conn structures.
36 ****************************************************************************/
37
38 void conn_init(struct smbd_server_connection *sconn)
39 {
40         sconn->smb1.tcons.Connections = NULL;
41         sconn->smb1.tcons.bmap = bitmap_talloc(sconn, BITMAP_BLOCK_SZ);
42 }
43
44 /****************************************************************************
45  Return the number of open connections.
46 ****************************************************************************/
47
48 int conn_num_open(struct smbd_server_connection *sconn)
49 {
50         return sconn->num_tcons_open;
51 }
52
53 /****************************************************************************
54  Check if a snum is in use.
55 ****************************************************************************/
56
57 bool conn_snum_used(int snum)
58 {
59         struct smbd_server_connection *sconn = smbd_server_conn;
60
61         if (sconn->using_smb2) {
62                 /* SMB2 */
63                 struct smbd_smb2_session *sess;
64                 for (sess = sconn->smb2.sessions.list; sess; sess = sess->next) {
65                         struct smbd_smb2_tcon *ptcon;
66
67                         for (ptcon = sess->tcons.list; ptcon; ptcon = ptcon->next) {
68                                 if (ptcon->compat_conn &&
69                                                 ptcon->compat_conn->params &&
70                                                 (ptcon->compat_conn->params->service == snum)) {
71                                         return true;
72                                 }
73                         }
74                 }
75         } else {
76                 /* SMB1 */
77                 connection_struct *conn;
78                 for (conn=sconn->smb1.tcons.Connections;conn;conn=conn->next) {
79                         if (conn->params->service == snum) {
80                                 return true;
81                         }
82                 }
83         }
84         return false;
85 }
86
87 /****************************************************************************
88  Find a conn given a cnum.
89 ****************************************************************************/
90
91 connection_struct *conn_find(struct smbd_server_connection *sconn,unsigned cnum)
92 {
93         if (sconn->using_smb2) {
94                 /* SMB2 */
95                 struct smbd_smb2_session *sess;
96                 for (sess = sconn->smb2.sessions.list; sess; sess = sess->next) {
97                         struct smbd_smb2_tcon *ptcon;
98
99                         for (ptcon = sess->tcons.list; ptcon; ptcon = ptcon->next) {
100                                 if (ptcon->compat_conn &&
101                                                 ptcon->compat_conn->cnum == cnum) {
102                                         return ptcon->compat_conn;
103                                 }
104                         }
105                 }
106         } else {
107                 /* SMB1 */
108                 int count=0;
109                 connection_struct *conn;
110                 for (conn=sconn->smb1.tcons.Connections;conn;conn=conn->next,count++) {
111                         if (conn->cnum == cnum) {
112                                 if (count > 10) {
113                                         DLIST_PROMOTE(sconn->smb1.tcons.Connections,
114                                                 conn);
115                                 }
116                                 return conn;
117                         }
118                 }
119         }
120
121         return NULL;
122 }
123
124 /****************************************************************************
125  Find first available connection slot, starting from a random position.
126  The randomisation stops problems with the server dieing and clients
127  thinking the server is still available.
128 ****************************************************************************/
129
130 connection_struct *conn_new(struct smbd_server_connection *sconn)
131 {
132         connection_struct *conn;
133         int i;
134         int find_offset = 1;
135
136         if (sconn->using_smb2) {
137                 /* SMB2 */
138                 if (!(conn=TALLOC_ZERO_P(NULL, connection_struct)) ||
139                     !(conn->params = TALLOC_P(conn, struct share_params))) {
140                         DEBUG(0,("TALLOC_ZERO() failed!\n"));
141                         TALLOC_FREE(conn);
142                         return NULL;
143                 }
144                 conn->sconn = sconn;
145                 return conn;
146         }
147
148         /* SMB1 */
149 find_again:
150         i = bitmap_find(sconn->smb1.tcons.bmap, find_offset);
151
152         if (i == -1) {
153                 /* Expand the connections bitmap. */
154                 int             oldsz = sconn->smb1.tcons.bmap->n;
155                 int             newsz = sconn->smb1.tcons.bmap->n +
156                                         BITMAP_BLOCK_SZ;
157                 struct bitmap * nbmap;
158
159                 if (newsz <= oldsz) {
160                         /* Integer wrap. */
161                         DEBUG(0,("ERROR! Out of connection structures\n"));
162                         return NULL;
163                 }
164
165                 DEBUG(4,("resizing connections bitmap from %d to %d\n",
166                         oldsz, newsz));
167
168                 nbmap = bitmap_talloc(sconn, newsz);
169                 if (!nbmap) {
170                         DEBUG(0,("ERROR! malloc fail.\n"));
171                         return NULL;
172                 }
173
174                 bitmap_copy(nbmap, sconn->smb1.tcons.bmap);
175                 TALLOC_FREE(sconn->smb1.tcons.bmap);
176
177                 sconn->smb1.tcons.bmap = nbmap;
178                 find_offset = oldsz; /* Start next search in the new portion. */
179
180                 goto find_again;
181         }
182
183         /* The bitmap position is used below as the connection number
184          * conn->cnum). This ends up as the TID field in the SMB header,
185          * which is limited to 16 bits (we skip 0xffff which is the
186          * NULL TID).
187          */
188         if (i > 65534) {
189                 DEBUG(0, ("Maximum connection limit reached\n"));
190                 return NULL;
191         }
192
193         if (!(conn=TALLOC_ZERO_P(NULL, connection_struct)) ||
194             !(conn->params = TALLOC_P(conn, struct share_params))) {
195                 DEBUG(0,("TALLOC_ZERO() failed!\n"));
196                 TALLOC_FREE(conn);
197                 return NULL;
198         }
199         conn->sconn = sconn;
200         conn->cnum = i;
201         conn->force_group_gid = (gid_t)-1;
202
203         bitmap_set(sconn->smb1.tcons.bmap, i);
204
205         sconn->num_tcons_open++;
206
207         string_set(&conn->connectpath,"");
208         string_set(&conn->origpath,"");
209
210         DLIST_ADD(sconn->smb1.tcons.Connections, conn);
211
212         return conn;
213 }
214
215 /****************************************************************************
216  Close all conn structures.
217  Return true if any were closed.
218 ****************************************************************************/
219
220 bool conn_close_all(struct smbd_server_connection *sconn)
221 {
222         bool ret = false;
223         if (sconn->using_smb2) {
224                 /* SMB2 */
225                 struct smbd_smb2_session *sess;
226                 for (sess = sconn->smb2.sessions.list; sess; sess = sess->next) {
227                         struct smbd_smb2_tcon *tcon, *tc_next;
228
229                         for (tcon = sess->tcons.list; tcon; tcon = tc_next) {
230                                 tc_next = tcon->next;
231                                 TALLOC_FREE(tcon);
232                                 ret = true;
233                         }
234                 }
235         } else {
236                 /* SMB1 */
237                 connection_struct *conn, *next;
238
239                 for (conn=sconn->smb1.tcons.Connections;conn;conn=next) {
240                         next=conn->next;
241                         set_current_service(conn, 0, True);
242                         close_cnum(conn, conn->vuid);
243                         ret = true;
244                 }
245         }
246         return ret;
247 }
248
249 /****************************************************************************
250  Update last used timestamps.
251 ****************************************************************************/
252
253 static void conn_lastused_update(struct smbd_server_connection *sconn,time_t t)
254 {
255         if (sconn->using_smb2) {
256                 /* SMB2 */
257                 struct smbd_smb2_session *sess;
258                 for (sess = sconn->smb2.sessions.list; sess; sess = sess->next) {
259                         struct smbd_smb2_tcon *ptcon;
260
261                         for (ptcon = sess->tcons.list; ptcon; ptcon = ptcon->next) {
262                                 connection_struct *conn = ptcon->compat_conn;
263                                 /* Update if connection wasn't idle. */
264                                 if (conn && conn->lastused != conn->lastused_count) {
265                                         conn->lastused = t;
266                                         conn->lastused_count = t;
267                                 }
268                         }
269                 }
270         } else {
271                 /* SMB1 */
272                 connection_struct *conn;
273                 for (conn=sconn->smb1.tcons.Connections;conn;conn=conn->next) {
274                         /* Update if connection wasn't idle. */
275                         if (conn->lastused != conn->lastused_count) {
276                                 conn->lastused = t;
277                                 conn->lastused_count = t;
278                         }
279                 }
280         }
281 }
282
283 /****************************************************************************
284  Idle inactive connections.
285 ****************************************************************************/
286
287 bool conn_idle_all(struct smbd_server_connection *sconn, time_t t)
288 {
289         int deadtime = lp_deadtime()*60;
290
291         conn_lastused_update(sconn, t);
292
293         if (deadtime <= 0) {
294                 deadtime = DEFAULT_SMBD_TIMEOUT;
295         }
296
297         if (sconn->using_smb2) {
298                 /* SMB2 */
299                 struct smbd_smb2_session *sess;
300                 for (sess = sconn->smb2.sessions.list; sess; sess = sess->next) {
301                         struct smbd_smb2_tcon *ptcon;
302
303                         for (ptcon = sess->tcons.list; ptcon; ptcon = ptcon->next) {
304                                 time_t age;
305                                 connection_struct *conn = ptcon->compat_conn;
306
307                                 if (conn == NULL) {
308                                         continue;
309                                 }
310
311                                 age = t - conn->lastused;
312                                 /* close dirptrs on connections that are idle */
313                                 if (age > DPTR_IDLE_TIMEOUT) {
314                                         dptr_idlecnum(conn);
315                                 }
316
317                                 if (conn->num_files_open > 0 || age < deadtime) {
318                                         return false;
319                                 }
320                         }
321                 }
322         } else {
323                 /* SMB1 */
324                 connection_struct *conn;
325                 for (conn=sconn->smb1.tcons.Connections;conn;conn=conn->next) {
326                         time_t age = t - conn->lastused;
327
328                         /* close dirptrs on connections that are idle */
329                         if (age > DPTR_IDLE_TIMEOUT) {
330                                 dptr_idlecnum(conn);
331                         }
332
333                         if (conn->num_files_open > 0 || age < deadtime) {
334                                 return false;
335                         }
336                 }
337         }
338
339         /*
340          * Check all pipes for any open handles. We cannot
341          * idle with a handle open.
342          */
343         if (check_open_pipes()) {
344                 return false;
345         }
346
347         return true;
348 }
349
350 /****************************************************************************
351  Clear a vuid out of the validity cache, and as the 'owner' of a connection.
352 ****************************************************************************/
353
354 void conn_clear_vuid_caches(struct smbd_server_connection *sconn,uint16_t vuid)
355 {
356         connection_struct *conn;
357
358         if (sconn->using_smb2) {
359                 /* SMB2 */
360                 struct smbd_smb2_session *sess;
361                 for (sess = sconn->smb2.sessions.list; sess; sess = sess->next) {
362                         struct smbd_smb2_tcon *ptcon;
363
364                         for (ptcon = sess->tcons.list; ptcon; ptcon = ptcon->next) {
365                                 if (ptcon->compat_conn) {
366                                         if (ptcon->compat_conn->vuid == vuid) {
367                                                 ptcon->compat_conn->vuid = UID_FIELD_INVALID;
368                                         }
369                                         conn_clear_vuid_cache(ptcon->compat_conn, vuid);
370                                 }
371                         }
372                 }
373         } else {
374                 /* SMB1 */
375                 for (conn=sconn->smb1.tcons.Connections;conn;conn=conn->next) {
376                         if (conn->vuid == vuid) {
377                                 conn->vuid = UID_FIELD_INVALID;
378                         }
379                         conn_clear_vuid_cache(conn, vuid);
380                 }
381         }
382 }
383
384 /****************************************************************************
385  Free a conn structure - internal part.
386 ****************************************************************************/
387
388 static void conn_free_internal(connection_struct *conn)
389 {
390         vfs_handle_struct *handle = NULL, *thandle = NULL;
391         struct trans_state *state = NULL;
392
393         /* Free vfs_connection_struct */
394         handle = conn->vfs_handles;
395         while(handle) {
396                 thandle = handle->next;
397                 DLIST_REMOVE(conn->vfs_handles, handle);
398                 if (handle->free_data)
399                         handle->free_data(&handle->data);
400                 handle = thandle;
401         }
402
403         /* Free any pending transactions stored on this conn. */
404         for (state = conn->pending_trans; state; state = state->next) {
405                 /* state->setup is a talloc child of state. */
406                 SAFE_FREE(state->param);
407                 SAFE_FREE(state->data);
408         }
409
410         free_namearray(conn->veto_list);
411         free_namearray(conn->hide_list);
412         free_namearray(conn->veto_oplock_list);
413         free_namearray(conn->aio_write_behind_list);
414
415         string_free(&conn->connectpath);
416         string_free(&conn->origpath);
417
418         ZERO_STRUCTP(conn);
419         talloc_destroy(conn);
420 }
421
422 /****************************************************************************
423  Free a conn structure.
424 ****************************************************************************/
425
426 void conn_free(connection_struct *conn)
427 {
428         if (conn->sconn == NULL) {
429                 conn_free_internal(conn);
430                 return;
431         }
432
433         if (conn->sconn->using_smb2) {
434                 /* SMB2 */
435                 conn_free_internal(conn);
436                 return;
437         }
438
439         /* SMB1 */
440         DLIST_REMOVE(conn->sconn->smb1.tcons.Connections, conn);
441
442         if (conn->sconn->smb1.tcons.bmap != NULL) {
443                 /*
444                  * Can be NULL for fake connections created by
445                  * create_conn_struct()
446                  */
447                 bitmap_clear(conn->sconn->smb1.tcons.bmap, conn->cnum);
448         }
449
450         SMB_ASSERT(conn->sconn->num_tcons_open > 0);
451         conn->sconn->num_tcons_open--;
452
453         conn_free_internal(conn);
454 }
455
456 /****************************************************************************
457  Receive a smbcontrol message to forcibly unmount a share.
458  The message contains just a share name and all instances of that
459  share are unmounted.
460  The special sharename '*' forces unmount of all shares.
461 ****************************************************************************/
462
463 void msg_force_tdis(struct messaging_context *msg,
464                     void *private_data,
465                     uint32_t msg_type,
466                     struct server_id server_id,
467                     DATA_BLOB *data)
468 {
469         struct smbd_server_connection *sconn;
470         connection_struct *conn, *next;
471         fstring sharename;
472
473         sconn = msg_ctx_to_sconn(msg);
474         if (sconn == NULL) {
475                 DEBUG(1, ("could not find sconn\n"));
476                 return;
477         }
478
479         fstrcpy(sharename, (const char *)data->data);
480
481         if (strcmp(sharename, "*") == 0) {
482                 DEBUG(1,("Forcing close of all shares\n"));
483                 conn_close_all(sconn);
484                 return;
485         }
486
487         if (sconn->using_smb2) {
488                 /* SMB2 */
489                 struct smbd_smb2_session *sess;
490                 for (sess = sconn->smb2.sessions.list; sess; sess = sess->next) {
491                         struct smbd_smb2_tcon *tcon, *tc_next;
492
493                         for (tcon = sess->tcons.list; tcon; tcon = tc_next) {
494                                 tc_next = tcon->next;
495                                 if (tcon->compat_conn &&
496                                                 strequal(lp_servicename(SNUM(tcon->compat_conn)),
497                                                                 sharename)) {
498                                         DEBUG(1,("Forcing close of share %s cnum=%d\n",
499                                                 sharename, tcon->compat_conn->cnum));
500                                         TALLOC_FREE(tcon);
501                                 }
502                         }
503                 }
504         } else {
505                 /* SMB1 */
506                 for (conn=sconn->smb1.tcons.Connections;conn;conn=next) {
507                         next=conn->next;
508                         if (strequal(lp_servicename(SNUM(conn)), sharename)) {
509                                 DEBUG(1,("Forcing close of share %s cnum=%d\n",
510                                         sharename, conn->cnum));
511                                 close_cnum(conn, (uint16)-1);
512                         }
513                 }
514         }
515 }