summaryrefslogtreecommitdiff
path: root/source4/smbd/connection.c
blob: 35f5138956dbbef1db321d3f2d6ea9a14f7231d4 (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
/* 
   Unix SMB/CIFS implementation.
   connection claim routines
   Copyright (C) Andrew Tridgell 1998
   
   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 2 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, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include "includes.h"

static TDB_CONTEXT *tdb;


static void make_conn_key(struct tcon_context *conn, const char *name, TDB_DATA *pkbuf, struct connections_key *pkey)
{
	ZERO_STRUCTP(pkey);
	pkey->pid = getpid();
	pkey->cnum = conn?conn->cnum:-1;
	fstrcpy(pkey->name, name);

	pkbuf->dptr = (char *)pkey;
	pkbuf->dsize = sizeof(*pkey);
}

/****************************************************************************
 Delete a connection record.
****************************************************************************/

BOOL yield_connection(struct tcon_context *conn, const char *name)
{
	struct connections_key key;
	TDB_DATA kbuf;

	if (!tdb)
		return False;

	DEBUG(3,("Yielding connection to %s\n",name));

	make_conn_key(conn, name, &kbuf, &key);

	if (tdb_delete(tdb, kbuf) != 0) {
		int dbg_lvl = (!conn && (tdb_error(tdb) == TDB_ERR_NOEXIST)) ? 3 : 0;
		DEBUG(dbg_lvl,("yield_connection: tdb_delete for name %s failed with error %s.\n",
			name, tdb_errorstr(tdb) ));
		return (False);
	}

	return(True);
}

struct count_stat {
	pid_t mypid;
	int curr_connections;
	char *name;
	BOOL Clear;
};

/****************************************************************************
 Count the entries belonging to a service in the connection db.
****************************************************************************/

static int count_fn( TDB_CONTEXT *the_tdb, TDB_DATA kbuf, TDB_DATA dbuf, void *udp)
{
	struct connections_data crec;
	struct count_stat *cs = (struct count_stat *)udp;
 
	if (dbuf.dsize != sizeof(crec))
		return 0;

	memcpy(&crec, dbuf.dptr, sizeof(crec));
 
	if (crec.cnum == -1)
		return 0;

	/* If the pid was not found delete the entry from connections.tdb */

	if (cs->Clear && !process_exists(crec.pid) && (errno == ESRCH)) {
		DEBUG(2,("pid %u doesn't exist - deleting connections %d [%s]\n",
			(unsigned int)crec.pid, crec.cnum, crec.name));
		if (tdb_delete(the_tdb, kbuf) != 0)
			DEBUG(0,("count_fn: tdb_delete failed with error %s\n", tdb_errorstr(tdb) ));
		return 0;
	}

	if (strequal(crec.name, cs->name))
		cs->curr_connections++;

	return 0;
}

/****************************************************************************
 Claim an entry in the connections database.
****************************************************************************/

BOOL claim_connection(struct tcon_context *conn, const char *name,int max_connections,BOOL Clear, uint32 msg_flags)
{
	struct connections_key key;
	struct connections_data crec;
	TDB_DATA kbuf, dbuf;

	if (!tdb)
		tdb = tdb_open_log(lock_path(conn->mem_ctx, "connections.tdb"), 0, TDB_CLEAR_IF_FIRST|TDB_DEFAULT, 
			       O_RDWR | O_CREAT, 0644);

	if (!tdb)
		return False;

	/*
	 * Enforce the max connections parameter.
	 */

	if (max_connections > 0) {
		struct count_stat cs;

		cs.mypid = getpid();
		cs.curr_connections = 0;
		cs.name = lp_servicename(SNUM(conn));
		cs.Clear = Clear;

		/*
		 * This has a race condition, but locking the chain before hand is worse
		 * as it leads to deadlock.
		 */

		if (tdb_traverse(tdb, count_fn, &cs) == -1) {
			DEBUG(0,("claim_connection: traverse of connections.tdb failed with error %s.\n",
				tdb_errorstr(tdb) ));
			return False;
		}

		if (cs.curr_connections >= max_connections) {
			DEBUG(1,("claim_connection: Max connections (%d) exceeded for %s\n",
				max_connections, name ));
			return False;
		}
	}

	DEBUG(5,("claiming %s %d\n",name,max_connections));

	make_conn_key(conn, name, &kbuf, &key);

	/* fill in the crec */
	ZERO_STRUCT(crec);
	crec.magic = 0x280267;
	crec.pid = getpid();
	crec.cnum = conn?conn->cnum:-1;
	if (conn) {
		crec.uid = -1;
		crec.gid = -1;
		StrnCpy(crec.name,
			lp_servicename(SNUM(conn)),sizeof(crec.name)-1);
	}
	crec.start = time(NULL);
	crec.bcast_msg_flags = msg_flags;
	
	StrnCpy(crec.machine,sub_get_remote_machine(),sizeof(crec.machine)-1);
	StrnCpy(crec.addr,conn?conn->smb->socket.client_addr:"NONE",sizeof(crec.addr)-1);

	dbuf.dptr = (char *)&crec;
	dbuf.dsize = sizeof(crec);

	if (tdb_store(tdb, kbuf, dbuf, TDB_REPLACE) != 0) {
		DEBUG(0,("claim_connection: tdb_store failed with error %s.\n",
			tdb_errorstr(tdb) ));
		return False;
	}

	return True;
}

BOOL register_message_flags(BOOL doreg, uint32 msg_flags)
{
	struct connections_key key;
	struct connections_data *pcrec;
	TDB_DATA kbuf, dbuf;

	if (!tdb)
		return False;

	DEBUG(10,("register_message_flags: %s flags 0x%x\n",
		doreg ? "adding" : "removing",
		(unsigned int)msg_flags ));

	make_conn_key(NULL, "", &kbuf, &key);

        dbuf = tdb_fetch(tdb, kbuf);
        if (!dbuf.dptr) {
		DEBUG(0,("register_message_flags: tdb_fetch failed\n"));
		return False;
	}

	pcrec = (struct connections_data *)dbuf.dptr;
	pcrec->bcast_msg_flags = msg_flags;
	if (doreg)
		pcrec->bcast_msg_flags |= msg_flags;
	else
		pcrec->bcast_msg_flags &= ~msg_flags;

	if (tdb_store(tdb, kbuf, dbuf, TDB_REPLACE) != 0) {
		DEBUG(0,("register_message_flags: tdb_store failed with error %s.\n",
			tdb_errorstr(tdb) ));
		SAFE_FREE(dbuf.dptr);
		return False;
	}

	DEBUG(10,("register_message_flags: new flags 0x%x\n",
		(unsigned int)pcrec->bcast_msg_flags ));

	SAFE_FREE(dbuf.dptr);
	return True;
}