haproxy/include/proto/protocol.h
Willy Tarreau daacf36645 BUG/MEDIUM: protocols: add a global lock for the init/deinit stuff
Dragan Dosen found that the listeners lock is not sufficient to protect
the listeners list when proxies are stopping because the listeners are
also unlinked from the protocol list, and under certain situations like
bombing with soft-stop signals or shutting down many frontends in parallel
from multiple CLI connections, it could be possible to provoke multiple
instances of delete_listener() to be called in parallel for different
listeners, thus corrupting the protocol lists.

Such operations are pretty rare, they are performed once per proxy upon
startup and once per proxy on shut down. Thus there is no point trying
to optimize anything and we can use a global lock to protect the protocol
lists during these manipulations.

This fix (or a variant) will have to be backported as far as 1.8.
2019-07-24 16:45:02 +02:00

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2.3 KiB
C

/*
* include/proto/protocol.h
* This file declares generic protocol management primitives.
*
* Copyright (C) 2000-2012 Willy Tarreau - w@1wt.eu
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation, version 2.1
* exclusively.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef _PROTO_PROTOCOL_H
#define _PROTO_PROTOCOL_H
#include <sys/socket.h>
#include <common/hathreads.h>
#include <types/protocol.h>
extern struct protocol *__protocol_by_family[AF_CUST_MAX];
__decl_hathreads(extern HA_SPINLOCK_T proto_lock);
/* Registers the protocol <proto> */
void protocol_register(struct protocol *proto);
/* Unregisters the protocol <proto>. Note that all listeners must have
* previously been unbound.
*/
void protocol_unregister(struct protocol *proto);
/* binds all listeners of all registered protocols. Returns a composition
* of ERR_NONE, ERR_RETRYABLE, ERR_FATAL.
*/
int protocol_bind_all(char *errmsg, int errlen);
/* unbinds all listeners of all registered protocols. They are also closed.
* This must be performed before calling exit() in order to get a chance to
* remove file-system based sockets and pipes.
* Returns a composition of ERR_NONE, ERR_RETRYABLE, ERR_FATAL.
*/
int protocol_unbind_all(void);
/* enables all listeners of all registered protocols. This is intended to be
* used after a fork() to enable reading on all file descriptors. Returns a
* composition of ERR_NONE, ERR_RETRYABLE, ERR_FATAL.
*/
int protocol_enable_all(void);
/* returns the protocol associated to family <family> or NULL if not found */
static inline struct protocol *protocol_by_family(int family)
{
if (family >= 0 && family < AF_CUST_MAX)
return __protocol_by_family[family];
return NULL;
}
#endif /* _PROTO_PROTOCOL_H */
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* End:
*/