haproxy/include/proto/port_range.h
Willy Tarreau c6f4ce8fc4 [MEDIUM] add support for binding to source port ranges during connect
Some users are already hitting the 64k source port limit when
connecting to servers. The system usually maintains a list of
unused source ports, regardless of the source IP they're bound
to. So in order to go beyond the 64k concurrent connections, we
have to manage the source ip:port lists ourselves.

The solution consists in assigning a source port range to each
server and use a free port in that range when connecting to that
server, either for a proxied connection or for a health check.
The port must then be put back into the server's range when the
connection is closed.

This mechanism is used only when a port range is specified on
a server. It makes it possible to reach 64k connections per
server, possibly all from the same IP address. Right now it
should be more than enough even for huge deployments.
2009-06-10 12:23:32 +02:00

78 lines
2.1 KiB
C

/*
include/proto/port_range.h
This file defines everything needed to manage port ranges
Copyright (C) 2000-2009 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_PORT_RANGE_H
#define _PROTO_PORT_RANGE_H
#include <types/port_range.h>
/* return an available port from range <range>, or zero if none is left */
static inline int port_range_alloc_port(struct port_range *range)
{
int ret;
if (!range->avail)
return 0;
ret = range->ports[range->get];
range->get++;
if (range->get >= range->size)
range->get = 0;
range->avail--;
return ret;
}
/* release port <port> into port range <range>. Does nothing if <port> is zero
* nor if <range> is null. The caller is responsible for marking the port
* unused by either setting the port to zero or the range to NULL.
*/
static inline void port_range_release_port(struct port_range *range, int port)
{
if (!port || !range)
return;
range->ports[range->put] = port;
range->avail++;
range->put++;
if (range->put >= range->size)
range->put = 0;
}
/* return a new initialized port range of N ports. The ports are not
* filled in, it's up to the caller to do it.
*/
static inline struct port_range *port_range_alloc_range(int n)
{
struct port_range *ret;
ret = calloc(1, sizeof(struct port_range) +
n * sizeof(((struct port_range *)0)->ports[0]));
ret->size = ret->avail = n;
return ret;
}
#endif /* _PROTO_PORT_RANGE_H */
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* End:
*/