samba-mirror/source3/smbd/connection.c

/* 
   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 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/>.
*/

#include "includes.h"

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

BOOL yield_connection(connection_struct *conn, const char *name)
{
	struct db_record *rec;
	NTSTATUS status;

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

	if (!(rec = connections_fetch_entry(NULL, conn, name))) {
		DEBUG(0, ("connections_fetch_entry failed\n"));
		return False;
	}

	status = rec->delete_rec(rec);
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG( NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND) ? 3 : 0,
		       ("deleting connection record returned %s\n",
			nt_errstr(status)));
	}

	TALLOC_FREE(rec);
	return NT_STATUS_IS_OK(status);
}

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

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

static int count_fn(struct db_record *rec,
		    const struct connections_key *ckey,
		    const struct connections_data *crec,
		    void *udp)
{
	struct count_stat *cs = (struct count_stat *)udp;
 
	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)) {
		NTSTATUS status;
		DEBUG(2,("pid %s doesn't exist - deleting connections %d [%s]\n",
			 procid_str_static(&crec->pid), crec->cnum,
			 crec->servicename));

		status = rec->delete_rec(rec);
		if (!NT_STATUS_IS_OK(status)) {
			DEBUG(0,("count_fn: tdb_delete failed with error %s\n",
				 nt_errstr(status)));
		}
		return 0;
	}
 
	if (cs->name) {
		/* We are counting all the connections to a given share. */
		if (strequal(crec->servicename, cs->name)) {
			cs->curr_connections++;
		}
	} else {
		/* We are counting all the connections. Static registrations
		 * like the lpq backgroud process and the smbd daemon process
		 * have a cnum of -1, so won't be counted here.
		 */
		cs->curr_connections++;
	}

	return 0;
}

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

int count_current_connections( const char *sharename, BOOL clear  )
{
	struct count_stat cs;

	cs.mypid = sys_getpid();
	cs.curr_connections = 0;
	cs.name = sharename;
	cs.Clear = clear;

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

	if (connections_forall(count_fn, &cs) == -1) {
		DEBUG(0,("count_current_connections: traverse of "
			 "connections.tdb failed\n"));
		DEBUGADD(0, ("count_current_connections: connection count of %d might not be accurate",
			    cs.curr_connections));
	}

	/* If the traverse failed part-way through, we at least return
	 * as many connections as we had already counted. If it failed
	 * right at the start, we will return 0, which is about all we
	 * can do anywway.
	 */

	return cs.curr_connections;
}

/****************************************************************************
 Count the number of connections open across all shares.
****************************************************************************/

int count_all_current_connections(void)
{
	return count_current_connections(NULL, True /* clear stale entries */);
}

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

BOOL claim_connection(connection_struct *conn, const char *name,
		      uint32 msg_flags)
{
	struct db_record *rec;
	struct connections_data crec;
	TDB_DATA dbuf;
	NTSTATUS status;

	DEBUG(5,("claiming [%s]\n", name));

	if (!(rec = connections_fetch_entry(NULL, conn, name))) {
		DEBUG(0, ("connections_fetch_entry failed\n"));
		return False;
	}

	/* fill in the crec */
	ZERO_STRUCT(crec);
	crec.magic = 0x280267;
	crec.pid = procid_self();
	crec.cnum = conn?conn->cnum:-1;
	if (conn) {
		crec.uid = conn->uid;
		crec.gid = conn->gid;
		strlcpy(crec.servicename, lp_servicename(SNUM(conn)),
			sizeof(crec.servicename));
	}
	crec.start = time(NULL);
	crec.bcast_msg_flags = msg_flags;
	
	strlcpy(crec.machine,get_remote_machine_name(),sizeof(crec.machine));
	strlcpy(crec.addr,conn?conn->client_address:client_addr(),
		sizeof(crec.addr));

	dbuf.dptr = (uint8 *)&crec;
	dbuf.dsize = sizeof(crec);

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

	TALLOC_FREE(rec);

	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(0,("claim_connection: tdb_store failed with error %s.\n",
			 nt_errstr(status)));
		return False;
	}

	return True;
}

BOOL register_message_flags(BOOL doreg, uint32 msg_flags)
{
	struct db_record *rec;
	struct connections_data *pcrec;
	NTSTATUS status;

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

	if (!(rec = connections_fetch_entry(NULL, NULL, ""))) {
		DEBUG(0, ("connections_fetch_entry failed\n"));
		return False;
	}

	if (rec->value.dsize != sizeof(struct connections_data)) {
		DEBUG(0,("register_message_flags: Got wrong record size\n"));
		TALLOC_FREE(rec);
		return False;
	}

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

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

	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(0,("register_message_flags: tdb_store failed: %s.\n",
			 nt_errstr(status)));
		TALLOC_FREE(rec);
		return False;
	}

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

	TALLOC_FREE(rec);

	return True;
}

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

static TDB_DATA* make_pipe_rec_key( struct pipe_open_rec *prec )
{
	TDB_DATA *kbuf = NULL;
	fstring key_string;
	
	if ( !prec )
		return NULL;
	
	if ( (kbuf = TALLOC_P(prec, TDB_DATA)) == NULL ) {
		return NULL;
	}
	
	snprintf( key_string, sizeof(key_string), "%s/%d/%d",
		prec->name, procid_to_pid(&prec->pid), prec->pnum );
		
	*kbuf = string_term_tdb_data(talloc_strdup(prec, key_string));
	if (kbuf->dptr == NULL )
		return NULL;

	return kbuf;
}

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

static void fill_pipe_open_rec( struct pipe_open_rec *prec, smb_np_struct *p )
{
	prec->pid = pid_to_procid(sys_getpid());
	prec->pnum = p->pnum;
	prec->uid = geteuid();
	fstrcpy( prec->name, p->name );

	return;
}

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

BOOL store_pipe_opendb( smb_np_struct *p )
{
	struct db_record *dbrec;
	struct pipe_open_rec *prec;
	TDB_DATA *key;
	TDB_DATA data;
	BOOL ret = False;
	
	if ( (prec = TALLOC_P( NULL, struct pipe_open_rec)) == NULL ) {
		DEBUG(0,("store_pipe_opendb: talloc failed!\n"));
		return False;
	}
	
	fill_pipe_open_rec( prec, p );
	if ( (key = make_pipe_rec_key( prec )) == NULL ) {
		goto done;
	}
	
	data.dptr = (uint8 *)prec;
	data.dsize = sizeof(struct pipe_open_rec);

	if (!(dbrec = connections_fetch_record(prec, *key))) {
		DEBUG(0, ("connections_fetch_record failed\n"));
		goto done;
	}

	ret = NT_STATUS_IS_OK(dbrec->store(dbrec, data, TDB_REPLACE));
	
done:
	TALLOC_FREE( prec );	
	return ret;
}

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

BOOL delete_pipe_opendb( smb_np_struct *p )
{
	struct db_record *dbrec;
	struct pipe_open_rec *prec;
	TDB_DATA *key;
	BOOL ret = False;
	
	if ( (prec = TALLOC_P( NULL, struct pipe_open_rec)) == NULL ) {
		DEBUG(0,("store_pipe_opendb: talloc failed!\n"));
		return False;
	}
	
	fill_pipe_open_rec( prec, p );
	if ( (key = make_pipe_rec_key( prec )) == NULL ) {
		goto done;
	}
	
	if (!(dbrec = connections_fetch_record(prec, *key))) {
		DEBUG(0, ("connections_fetch_record failed\n"));
		goto done;
	}

	ret = NT_STATUS_IS_OK(dbrec->delete_rec(dbrec));
	
done:
	TALLOC_FREE( prec );
	return ret;
}