import HEAD into svn+ssh://svn.samba.org/home/svn/samba/trunk
[metze/old/v3-2-winbind-ndr.git] / source / smbd / connection.c
1 /* 
2    Unix SMB/CIFS implementation.
3    connection claim routines
4    Copyright (C) Andrew Tridgell 1998
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 2 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, write to the Free Software
18    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20
21 #include "includes.h"
22
23 static TDB_CONTEXT *tdb;
24
25 /****************************************************************************
26  Return the connection tdb context (used for message send all).
27 ****************************************************************************/
28
29 TDB_CONTEXT *conn_tdb_ctx(void)
30 {
31         if (!tdb)
32                 tdb = tdb_open_ex(lock_path("connections.tdb"), 0, TDB_CLEAR_IF_FIRST|TDB_DEFAULT, 
33                                O_RDWR | O_CREAT, 0644, smbd_tdb_log);
34
35         return tdb;
36 }
37
38 static void make_conn_key(connection_struct *conn, const char *name, TDB_DATA *pkbuf, struct connections_key *pkey)
39 {
40         ZERO_STRUCTP(pkey);
41         pkey->pid = sys_getpid();
42         pkey->cnum = conn?conn->cnum:-1;
43         fstrcpy(pkey->name, name);
44 #ifdef DEVELOPER
45         /* valgrind fixer... */
46         {
47                 size_t sl = strlen(pkey->name);
48                 if (sizeof(fstring)-sl)
49                         memset(&pkey->name[sl], '\0', sizeof(fstring)-sl);
50         }
51 #endif
52
53         pkbuf->dptr = (char *)pkey;
54         pkbuf->dsize = sizeof(*pkey);
55 }
56
57 /****************************************************************************
58  Delete a connection record.
59 ****************************************************************************/
60
61 BOOL yield_connection(connection_struct *conn, const char *name)
62 {
63         struct connections_key key;
64         TDB_DATA kbuf;
65
66         if (!tdb)
67                 return False;
68
69         DEBUG(3,("Yielding connection to %s\n",name));
70
71         make_conn_key(conn, name, &kbuf, &key);
72
73         if (tdb_delete(tdb, kbuf) != 0) {
74                 int dbg_lvl = (!conn && (tdb_error(tdb) == TDB_ERR_NOEXIST)) ? 3 : 0;
75                 DEBUG(dbg_lvl,("yield_connection: tdb_delete for name %s failed with error %s.\n",
76                         name, tdb_errorstr(tdb) ));
77                 return (False);
78         }
79
80         return(True);
81 }
82
83 struct count_stat {
84         pid_t mypid;
85         int curr_connections;
86         char *name;
87         BOOL Clear;
88 };
89
90 /****************************************************************************
91  Count the entries belonging to a service in the connection db.
92 ****************************************************************************/
93
94 static int count_fn( TDB_CONTEXT *the_tdb, TDB_DATA kbuf, TDB_DATA dbuf, void *udp)
95 {
96         struct connections_data crec;
97         struct count_stat *cs = (struct count_stat *)udp;
98  
99         if (dbuf.dsize != sizeof(crec))
100                 return 0;
101
102         memcpy(&crec, dbuf.dptr, sizeof(crec));
103  
104         if (crec.cnum == -1)
105                 return 0;
106
107         /* If the pid was not found delete the entry from connections.tdb */
108
109         if (cs->Clear && !process_exists(crec.pid) && (errno == ESRCH)) {
110                 DEBUG(2,("pid %u doesn't exist - deleting connections %d [%s]\n",
111                         (unsigned int)crec.pid, crec.cnum, crec.name));
112                 if (tdb_delete(the_tdb, kbuf) != 0)
113                         DEBUG(0,("count_fn: tdb_delete failed with error %s\n", tdb_errorstr(tdb) ));
114                 return 0;
115         }
116
117         if (strequal(crec.name, cs->name))
118                 cs->curr_connections++;
119
120         return 0;
121 }
122
123 /****************************************************************************
124  Claim an entry in the connections database.
125 ****************************************************************************/
126
127 BOOL claim_connection(connection_struct *conn, const char *name,int max_connections,BOOL Clear, uint32 msg_flags)
128 {
129         struct connections_key key;
130         struct connections_data crec;
131         TDB_DATA kbuf, dbuf;
132
133         if (!tdb)
134                 tdb = tdb_open_ex(lock_path("connections.tdb"), 0, TDB_CLEAR_IF_FIRST|TDB_DEFAULT, 
135                                O_RDWR | O_CREAT, 0644, smbd_tdb_log);
136
137         if (!tdb)
138                 return False;
139
140         /*
141          * Enforce the max connections parameter.
142          */
143
144         if (max_connections > 0) {
145                 struct count_stat cs;
146
147                 cs.mypid = sys_getpid();
148                 cs.curr_connections = 0;
149                 cs.name = lp_servicename(SNUM(conn));
150                 cs.Clear = Clear;
151
152                 /*
153                  * This has a race condition, but locking the chain before hand is worse
154                  * as it leads to deadlock.
155                  */
156
157                 if (tdb_traverse(tdb, count_fn, &cs) == -1) {
158                         DEBUG(0,("claim_connection: traverse of connections.tdb failed with error %s.\n",
159                                 tdb_errorstr(tdb) ));
160                         return False;
161                 }
162
163                 if (cs.curr_connections >= max_connections) {
164                         DEBUG(1,("claim_connection: Max connections (%d) exceeded for %s\n",
165                                 max_connections, name ));
166                         return False;
167                 }
168         }
169
170         DEBUG(5,("claiming %s %d\n",name,max_connections));
171
172         make_conn_key(conn, name, &kbuf, &key);
173
174         /* fill in the crec */
175         ZERO_STRUCT(crec);
176         crec.magic = 0x280267;
177         crec.pid = sys_getpid();
178         crec.cnum = conn?conn->cnum:-1;
179         if (conn) {
180                 crec.uid = conn->uid;
181                 crec.gid = conn->gid;
182                 safe_strcpy(crec.name,
183                             lp_servicename(SNUM(conn)),sizeof(crec.name)-1);
184         }
185         crec.start = time(NULL);
186         crec.bcast_msg_flags = msg_flags;
187         
188         safe_strcpy(crec.machine,get_remote_machine_name(),sizeof(crec.machine)-1);
189         safe_strcpy(crec.addr,conn?conn->client_address:client_addr(),sizeof(crec.addr)-1);
190
191         dbuf.dptr = (char *)&crec;
192         dbuf.dsize = sizeof(crec);
193
194         if (tdb_store(tdb, kbuf, dbuf, TDB_REPLACE) != 0) {
195                 DEBUG(0,("claim_connection: tdb_store failed with error %s.\n",
196                         tdb_errorstr(tdb) ));
197                 return False;
198         }
199
200         return True;
201 }
202
203 BOOL register_message_flags(BOOL doreg, uint32 msg_flags)
204 {
205         struct connections_key key;
206         struct connections_data *pcrec;
207         TDB_DATA kbuf, dbuf;
208
209         if (!tdb)
210                 return False;
211
212         DEBUG(10,("register_message_flags: %s flags 0x%x\n",
213                 doreg ? "adding" : "removing",
214                 (unsigned int)msg_flags ));
215
216         make_conn_key(NULL, "", &kbuf, &key);
217
218         dbuf = tdb_fetch(tdb, kbuf);
219         if (!dbuf.dptr) {
220                 DEBUG(0,("register_message_flags: tdb_fetch failed\n"));
221                 return False;
222         }
223
224         pcrec = (struct connections_data *)dbuf.dptr;
225         pcrec->bcast_msg_flags = msg_flags;
226         if (doreg)
227                 pcrec->bcast_msg_flags |= msg_flags;
228         else
229                 pcrec->bcast_msg_flags &= ~msg_flags;
230
231         if (tdb_store(tdb, kbuf, dbuf, TDB_REPLACE) != 0) {
232                 DEBUG(0,("register_message_flags: tdb_store failed with error %s.\n",
233                         tdb_errorstr(tdb) ));
234                 SAFE_FREE(dbuf.dptr);
235                 return False;
236         }
237
238         DEBUG(10,("register_message_flags: new flags 0x%x\n",
239                 (unsigned int)pcrec->bcast_msg_flags ));
240
241         SAFE_FREE(dbuf.dptr);
242         return True;
243 }