lib/sharesec.c: fix the upgrade code, db_traverse returns the number of records!
[ira/wip.git] / source3 / lib / sharesec.c
1 /* 
2  *  Unix SMB/Netbios implementation.
3  *  SEC_DESC handling functions
4  *  Copyright (C) Jeremy R. Allison            1995-2003.
5  *  
6  *  This program is free software; you can redistribute it and/or modify
7  *  it under the terms of the GNU General Public License as published by
8  *  the Free Software Foundation; either version 3 of the License, or
9  *  (at your option) any later version.
10  *  
11  *  This program is distributed in the hope that it will be useful,
12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *  GNU General Public License for more details.
15  *  
16  *  You should have received a copy of the GNU General Public License
17  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
18  */
19
20 #include "includes.h"
21
22 /*******************************************************************
23  Create the share security tdb.
24  ********************************************************************/
25
26 static struct db_context *share_db; /* used for share security descriptors */
27 #define SHARE_DATABASE_VERSION_V1 1
28 #define SHARE_DATABASE_VERSION_V2 2 /* version id in little endian. */
29
30 /* Map generic permissions to file object specific permissions */
31
32 static const struct generic_mapping file_generic_mapping = {
33         FILE_GENERIC_READ,
34         FILE_GENERIC_WRITE,
35         FILE_GENERIC_EXECUTE,
36         FILE_GENERIC_ALL
37 };
38
39 static int delete_fn(struct db_record *rec, void *priv)
40 {
41         rec->delete_rec(rec);
42         return 0;
43 }
44
45 static bool share_info_db_init(void)
46 {
47         const char *vstring = "INFO/version";
48         int32 vers_id;
49  
50         if (share_db != NULL) {
51                 return True;
52         }
53
54         share_db = db_open_trans(NULL, state_path("share_info.tdb"), 0,
55                                  TDB_DEFAULT, O_RDWR|O_CREAT, 0600);
56         if (share_db == NULL) {
57                 DEBUG(0,("Failed to open share info database %s (%s)\n",
58                         state_path("share_info.tdb"), strerror(errno) ));
59                 return False;
60         }
61  
62         vers_id = dbwrap_fetch_int32(share_db, vstring);
63         if (vers_id == SHARE_DATABASE_VERSION_V2) {
64                 return true;
65         }
66
67         if (share_db->transaction_start(share_db) != 0) {
68                 DEBUG(0, ("transaction_start failed\n"));
69                 TALLOC_FREE(share_db);
70                 return false;
71         }
72
73         vers_id = dbwrap_fetch_int32(share_db, vstring);
74         if (vers_id == SHARE_DATABASE_VERSION_V2) {
75                 /*
76                  * Race condition
77                  */
78                 if (share_db->transaction_cancel(share_db)) {
79                         smb_panic("transaction_cancel failed");
80                 }
81                 return true;
82         }
83
84         /* Cope with byte-reversed older versions of the db. */
85         if ((vers_id == SHARE_DATABASE_VERSION_V1) || (IREV(vers_id) == SHARE_DATABASE_VERSION_V1)) {
86                 /* Written on a bigendian machine with old fetch_int code. Save as le. */
87
88                 if (dbwrap_store_int32(share_db, vstring,
89                                        SHARE_DATABASE_VERSION_V2) != 0) {
90                         DEBUG(0, ("dbwrap_store_int32 failed\n"));
91                         goto cancel;
92                 }
93                 vers_id = SHARE_DATABASE_VERSION_V2;
94         }
95
96         if (vers_id != SHARE_DATABASE_VERSION_V2) {
97                 int ret;
98                 ret = share_db->traverse(share_db, delete_fn, NULL);
99                 if (ret < 0) {
100                         DEBUG(0, ("traverse failed\n"));
101                         goto cancel;
102                 }
103                 if (dbwrap_store_int32(share_db, vstring,
104                                        SHARE_DATABASE_VERSION_V2) != 0) {
105                         DEBUG(0, ("dbwrap_store_int32 failed\n"));
106                         goto cancel;
107                 }
108         }
109
110         if (share_db->transaction_commit(share_db) != 0) {
111                 DEBUG(0, ("transaction_commit failed\n"));
112                 goto cancel;
113         }
114
115         return true;
116
117  cancel:
118         if (share_db->transaction_cancel(share_db)) {
119                 smb_panic("transaction_cancel failed");
120         }
121
122         return false;
123 }
124
125 /*******************************************************************
126  Fake up a Everyone, default access as a default.
127  def_access is a GENERIC_XXX access mode.
128  ********************************************************************/
129
130 SEC_DESC *get_share_security_default( TALLOC_CTX *ctx, size_t *psize, uint32 def_access)
131 {
132         SEC_ACCESS sa;
133         SEC_ACE ace;
134         SEC_ACL *psa = NULL;
135         SEC_DESC *psd = NULL;
136         uint32 spec_access = def_access;
137
138         se_map_generic(&spec_access, &file_generic_mapping);
139
140         init_sec_access(&sa, def_access | spec_access );
141         init_sec_ace(&ace, &global_sid_World, SEC_ACE_TYPE_ACCESS_ALLOWED, sa, 0);
142
143         if ((psa = make_sec_acl(ctx, NT4_ACL_REVISION, 1, &ace)) != NULL) {
144                 psd = make_sec_desc(ctx, SECURITY_DESCRIPTOR_REVISION_1,
145                                     SEC_DESC_SELF_RELATIVE, NULL, NULL, NULL,
146                                     psa, psize);
147         }
148
149         if (!psd) {
150                 DEBUG(0,("get_share_security: Failed to make SEC_DESC.\n"));
151                 return NULL;
152         }
153
154         return psd;
155 }
156
157 /*******************************************************************
158  Pull a security descriptor from the share tdb.
159  ********************************************************************/
160
161 SEC_DESC *get_share_security( TALLOC_CTX *ctx, const char *servicename,
162                               size_t *psize)
163 {
164         char *key;
165         SEC_DESC *psd = NULL;
166         TDB_DATA data;
167         NTSTATUS status;
168
169         if (!share_info_db_init()) {
170                 return NULL;
171         }
172
173         if (!(key = talloc_asprintf(ctx, "SECDESC/%s", servicename))) {
174                 DEBUG(0, ("talloc_asprintf failed\n"));
175                 return NULL;
176         }
177
178         data = dbwrap_fetch_bystring(share_db, talloc_tos(), key);
179
180         TALLOC_FREE(key);
181
182         if (data.dptr == NULL) {
183                 return get_share_security_default(ctx, psize,
184                                                   GENERIC_ALL_ACCESS);
185         }
186
187         status = unmarshall_sec_desc(ctx, data.dptr, data.dsize, &psd);
188
189         TALLOC_FREE(data.dptr);
190
191         if (!NT_STATUS_IS_OK(status)) {
192                 DEBUG(0, ("unmarshall_sec_desc failed: %s\n",
193                           nt_errstr(status)));
194                 return NULL;
195         }
196
197         if (psd)
198                 *psize = ndr_size_security_descriptor(psd, 0);
199
200         return psd;
201 }
202
203 /*******************************************************************
204  Store a security descriptor in the share db.
205  ********************************************************************/
206
207 bool set_share_security(const char *share_name, SEC_DESC *psd)
208 {
209         TALLOC_CTX *frame;
210         char *key;
211         bool ret = False;
212         TDB_DATA blob;
213         NTSTATUS status;
214
215         if (!share_info_db_init()) {
216                 return False;
217         }
218
219         frame = talloc_stackframe();
220
221         status = marshall_sec_desc(frame, psd, &blob.dptr, &blob.dsize);
222
223         if (!NT_STATUS_IS_OK(status)) {
224                 DEBUG(0, ("marshall_sec_desc failed: %s\n",
225                           nt_errstr(status)));
226                 goto out;
227         }
228
229         if (!(key = talloc_asprintf(frame, "SECDESC/%s", share_name))) {
230                 DEBUG(0, ("talloc_asprintf failed\n"));
231                 goto out;
232         }
233
234         status = dbwrap_trans_store(share_db, string_term_tdb_data(key), blob,
235                                     TDB_REPLACE);
236         if (!NT_STATUS_IS_OK(status)) {
237                 DEBUG(1, ("set_share_security: Failed to store secdesc for "
238                           "%s: %s\n", share_name, nt_errstr(status)));
239                 goto out;
240         }
241
242         DEBUG(5,("set_share_security: stored secdesc for %s\n", share_name ));
243         ret = True;
244
245  out:
246         TALLOC_FREE(frame);
247         return ret;
248 }
249
250 /*******************************************************************
251  Delete a security descriptor.
252 ********************************************************************/
253
254 bool delete_share_security(const char *servicename)
255 {
256         TDB_DATA kbuf;
257         char *key;
258         NTSTATUS status;
259
260         if (!(key = talloc_asprintf(talloc_tos(), "SECDESC/%s",
261                                     servicename))) {
262                 return False;
263         }
264         kbuf = string_term_tdb_data(key);
265
266         status = dbwrap_trans_delete(share_db, kbuf);
267         if (!NT_STATUS_IS_OK(status)) {
268                 DEBUG(0, ("delete_share_security: Failed to delete entry for "
269                           "share %s: %s\n", servicename, nt_errstr(status)));
270                 return False;
271         }
272
273         return True;
274 }
275
276 /*******************************************************************
277  Can this user access with share with the required permissions ?
278 ********************************************************************/
279
280 bool share_access_check(const NT_USER_TOKEN *token, const char *sharename,
281                         uint32 desired_access)
282 {
283         uint32 granted;
284         NTSTATUS status;
285         SEC_DESC *psd = NULL;
286         size_t sd_size;
287         bool ret = True;
288
289         psd = get_share_security(talloc_tos(), sharename, &sd_size);
290
291         if (!psd) {
292                 return True;
293         }
294
295         ret = se_access_check(psd, token, desired_access, &granted, &status);
296
297         TALLOC_FREE(psd);
298
299         return ret;
300 }
301
302 /***************************************************************************
303  Parse the contents of an acl string from a usershare file.
304 ***************************************************************************/
305
306 bool parse_usershare_acl(TALLOC_CTX *ctx, const char *acl_str, SEC_DESC **ppsd)
307 {
308         size_t s_size = 0;
309         const char *pacl = acl_str;
310         int num_aces = 0;
311         SEC_ACE *ace_list = NULL;
312         SEC_ACL *psa = NULL;
313         SEC_DESC *psd = NULL;
314         size_t sd_size = 0;
315         int i;
316
317         *ppsd = NULL;
318
319         /* If the acl string is blank return "Everyone:R" */
320         if (!*acl_str) {
321                 SEC_DESC *default_psd = get_share_security_default(ctx, &s_size, GENERIC_READ_ACCESS);
322                 if (!default_psd) {
323                         return False;
324                 }
325                 *ppsd = default_psd;
326                 return True;
327         }
328
329         num_aces = 1;
330
331         /* Add the number of ',' characters to get the number of aces. */
332         num_aces += count_chars(pacl,',');
333
334         ace_list = TALLOC_ARRAY(ctx, SEC_ACE, num_aces);
335         if (!ace_list) {
336                 return False;
337         }
338
339         for (i = 0; i < num_aces; i++) {
340                 SEC_ACCESS sa;
341                 uint32 g_access;
342                 uint32 s_access;
343                 DOM_SID sid;
344                 char *sidstr;
345                 enum security_ace_type type = SEC_ACE_TYPE_ACCESS_ALLOWED;
346
347                 if (!next_token_talloc(ctx, &pacl, &sidstr, ":")) {
348                         DEBUG(0,("parse_usershare_acl: malformed usershare acl looking "
349                                 "for ':' in string '%s'\n", pacl));
350                         return False;
351                 }
352
353                 if (!string_to_sid(&sid, sidstr)) {
354                         DEBUG(0,("parse_usershare_acl: failed to convert %s to sid.\n",
355                                 sidstr ));
356                         return False;
357                 }
358
359                 switch (*pacl) {
360                         case 'F': /* Full Control, ie. R+W */
361                         case 'f': /* Full Control, ie. R+W */
362                                 s_access = g_access = GENERIC_ALL_ACCESS;
363                                 break;
364                         case 'R': /* Read only. */
365                         case 'r': /* Read only. */
366                                 s_access = g_access = GENERIC_READ_ACCESS;
367                                 break;
368                         case 'D': /* Deny all to this SID. */
369                         case 'd': /* Deny all to this SID. */
370                                 type = SEC_ACE_TYPE_ACCESS_DENIED;
371                                 s_access = g_access = GENERIC_ALL_ACCESS;
372                                 break;
373                         default:
374                                 DEBUG(0,("parse_usershare_acl: unknown acl type at %s.\n",
375                                         pacl ));
376                                 return False;
377                 }
378
379                 pacl++;
380                 if (*pacl && *pacl != ',') {
381                         DEBUG(0,("parse_usershare_acl: bad acl string at %s.\n",
382                                 pacl ));
383                         return False;
384                 }
385                 pacl++; /* Go past any ',' */
386
387                 se_map_generic(&s_access, &file_generic_mapping);
388                 init_sec_access(&sa, g_access | s_access );
389                 init_sec_ace(&ace_list[i], &sid, type, sa, 0);
390         }
391
392         if ((psa = make_sec_acl(ctx, NT4_ACL_REVISION, num_aces, ace_list)) != NULL) {
393                 psd = make_sec_desc(ctx, SECURITY_DESCRIPTOR_REVISION_1,
394                                     SEC_DESC_SELF_RELATIVE, NULL, NULL, NULL,
395                                     psa, &sd_size);
396         }
397
398         if (!psd) {
399                 DEBUG(0,("parse_usershare_acl: Failed to make SEC_DESC.\n"));
400                 return False;
401         }
402
403         *ppsd = psd;
404         return True;
405 }