diff options
Diffstat (limited to 'source4/smbd/connection.c')
| -rw-r--r-- | source4/smbd/connection.c | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/source4/smbd/connection.c b/source4/smbd/connection.c new file mode 100644 index 0000000000..35f5138956 --- /dev/null +++ b/source4/smbd/connection.c @@ -0,0 +1,223 @@ +/* + 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; +} |