summaryrefslogtreecommitdiff
path: root/source3/smbd/session.c
blob: 3b431a19be006ef7f5accb0ce4cf18e2a4d6afdd (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
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
/* 
   Unix SMB/CIFS implementation.
   session handling for utmp and PAM

   Copyright (C) tridge@samba.org       2001
   Copyright (C) abartlet@samba.org     2001
   Copyright (C) Gerald (Jerry) Carter  2006   
   
   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/>.
*/

/* a "session" is claimed when we do a SessionSetupX operation
   and is yielded when the corresponding vuid is destroyed.

   sessions are used to populate utmp and PAM session structures
*/

#include "includes.h"

/********************************************************************
********************************************************************/

static struct db_context *session_db_ctx(void)
{
	static struct db_context *ctx;

	if (ctx)
		return ctx;

	ctx = db_open(NULL, lock_path("sessionid.tdb"), 0,
		      TDB_CLEAR_IF_FIRST|TDB_DEFAULT, 
		      O_RDWR | O_CREAT, 0644);
	return ctx;
}

bool session_init(void)
{
	if (session_db_ctx() == NULL) {
		DEBUG(1,("session_init: failed to open sessionid tdb\n"));
		return False;
	}

	return True;
}

/********************************************************************
 called when a session is created
********************************************************************/

bool session_claim(user_struct *vuser)
{
	TDB_DATA key, data;
	int i = 0;
	struct sessionid sessionid;
	struct server_id pid = procid_self();
	fstring keystr;
	const char * hostname;
	struct db_context *ctx;
	struct db_record *rec;
	NTSTATUS status;
	char addr[INET6_ADDRSTRLEN];

	vuser->session_keystr = NULL;

	/* don't register sessions for the guest user - its just too
	   expensive to go through pam session code for browsing etc */
	if (vuser->server_info->guest) {
		return True;
	}

	if (!(ctx = session_db_ctx())) {
		return False;
	}

	ZERO_STRUCT(sessionid);

	data.dptr = NULL;
	data.dsize = 0;

	if (lp_utmp()) {

		for (i=1;i<MAX_SESSION_ID;i++) {

			/*
			 * This is very inefficient and needs fixing -- vl
			 */

			struct server_id sess_pid;

			snprintf(keystr, sizeof(keystr), "ID/%d", i);
			key = string_term_tdb_data(keystr);

			rec = ctx->fetch_locked(ctx, NULL, key);

			if (rec == NULL) {
				DEBUG(1, ("Could not lock \"%s\"\n", keystr));
				return False;
			}

			if (rec->value.dsize != sizeof(sessionid)) {
				DEBUG(1, ("Re-using invalid record\n"));
				break;
			}

			sess_pid = ((struct sessionid *)rec->value.dptr)->pid;

			if (!process_exists(sess_pid)) {
				DEBUG(5, ("%s has died -- re-using session\n",
					  procid_str_static(&sess_pid)));
				break;
			}

			TALLOC_FREE(rec);
		}

		if (i == MAX_SESSION_ID) {
			SMB_ASSERT(rec == NULL);
			DEBUG(1,("session_claim: out of session IDs "
				 "(max is %d)\n", MAX_SESSION_ID));
			return False;
		}

		snprintf(sessionid.id_str, sizeof(sessionid.id_str),
			 SESSION_UTMP_TEMPLATE, i);
	} else
	{
		snprintf(keystr, sizeof(keystr), "ID/%s/%u",
			 procid_str_static(&pid), vuser->vuid);
		key = string_term_tdb_data(keystr);

		rec = ctx->fetch_locked(ctx, NULL, key);

		if (rec == NULL) {
			DEBUG(1, ("Could not lock \"%s\"\n", keystr));
			return False;
		}

		snprintf(sessionid.id_str, sizeof(sessionid.id_str),
			 SESSION_TEMPLATE, (long unsigned int)sys_getpid(),
			 vuser->vuid);
	}

	SMB_ASSERT(rec != NULL);

	/* If 'hostname lookup' == yes, then do the DNS lookup.  This is
           needed because utmp and PAM both expect DNS names

	   client_name() handles this case internally.
	*/

	hostname = client_name(get_client_fd());
	if (strcmp(hostname, "UNKNOWN") == 0) {
		hostname = client_addr(get_client_fd(),addr,sizeof(addr));
	}

	fstrcpy(sessionid.username, vuser->server_info->unix_name);
	fstrcpy(sessionid.hostname, hostname);
	sessionid.id_num = i;  /* Only valid for utmp sessions */
	sessionid.pid = pid;
	sessionid.uid = vuser->server_info->utok.uid;
	sessionid.gid = vuser->server_info->utok.gid;
	fstrcpy(sessionid.remote_machine, get_remote_machine_name());
	fstrcpy(sessionid.ip_addr_str,
		client_addr(get_client_fd(),addr,sizeof(addr)));
	sessionid.connect_start = time(NULL);

	if (!smb_pam_claim_session(sessionid.username, sessionid.id_str,
				   sessionid.hostname)) {
		DEBUG(1,("pam_session rejected the session for %s [%s]\n",
				sessionid.username, sessionid.id_str));

		TALLOC_FREE(rec);
		return False;
	}

	data.dptr = (uint8 *)&sessionid;
	data.dsize = sizeof(sessionid);

	status = rec->store(rec, data, TDB_REPLACE);

	TALLOC_FREE(rec);

	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(1,("session_claim: unable to create session id "
			 "record: %s\n", nt_errstr(status)));
		return False;
	}

	if (lp_utmp()) {
		sys_utmp_claim(sessionid.username, sessionid.hostname,
			       sessionid.ip_addr_str,
			       sessionid.id_str, sessionid.id_num);
	}

	vuser->session_keystr = talloc_strdup(vuser, keystr);
	if (!vuser->session_keystr) {
		DEBUG(0, ("session_claim:  talloc_strdup() failed for session_keystr\n"));
		return False;
	}
	return True;
}

/********************************************************************
 called when a session is destroyed
********************************************************************/

void session_yield(user_struct *vuser)
{
	TDB_DATA key;
	struct sessionid sessionid;
	struct db_context *ctx;
	struct db_record *rec;

	if (!(ctx = session_db_ctx())) return;

	if (!vuser->session_keystr) {
		return;
	}

	key = string_term_tdb_data(vuser->session_keystr);

	if (!(rec = ctx->fetch_locked(ctx, NULL, key))) {
		return;
	}

	if (rec->value.dsize != sizeof(sessionid))
		return;

	memcpy(&sessionid, rec->value.dptr, sizeof(sessionid));

	if (lp_utmp()) {
		sys_utmp_yield(sessionid.username, sessionid.hostname, 
			       sessionid.ip_addr_str,
			       sessionid.id_str, sessionid.id_num);
	}

	smb_pam_close_session(sessionid.username, sessionid.id_str,
			      sessionid.hostname);

	rec->delete_rec(rec);

	TALLOC_FREE(rec);
}

/********************************************************************
********************************************************************/

static bool session_traverse(int (*fn)(struct db_record *db,
				       void *private_data),
			     void *private_data)
{
	struct db_context *ctx;

	if (!(ctx = session_db_ctx())) {
		DEBUG(3, ("No tdb opened\n"));
		return False;
	}

	ctx->traverse_read(ctx, fn, private_data);
	return True;
}

/********************************************************************
********************************************************************/

struct session_list {
	TALLOC_CTX *mem_ctx;
	int count;
	struct sessionid *sessions;
};

static int gather_sessioninfo(struct db_record *rec, void *state)
{
	struct session_list *sesslist = (struct session_list *) state;
	const struct sessionid *current =
		(const struct sessionid *) rec->value.dptr;

	sesslist->sessions = TALLOC_REALLOC_ARRAY(
		sesslist->mem_ctx, sesslist->sessions, struct sessionid,
		sesslist->count+1);

	if (!sesslist->sessions) {
		sesslist->count = 0;
		return -1;
	}

	memcpy(&sesslist->sessions[sesslist->count], current,
	       sizeof(struct sessionid));

	sesslist->count++;

	DEBUG(7,("gather_sessioninfo session from %s@%s\n", 
		 current->username, current->remote_machine));

	return 0;
}

/********************************************************************
********************************************************************/

int list_sessions(TALLOC_CTX *mem_ctx, struct sessionid **session_list)
{
	struct session_list sesslist;

	sesslist.mem_ctx = mem_ctx;
	sesslist.count = 0;
	sesslist.sessions = NULL;
	
	if (!session_traverse(gather_sessioninfo, (void *) &sesslist)) {
		DEBUG(3, ("Session traverse failed\n"));
		SAFE_FREE(sesslist.sessions);
		*session_list = NULL;
		return 0;
	}

	*session_list = sesslist.sessions;
	return sesslist.count;
}