Load balance sockets with new SO_REUSEPORT_LB option

This patch adds a new socket option, SO_REUSEPORT_LB, which allow multiple
programs or threads to bind to the same port and incoming connections will be
load balanced using a hash function.

Most of the code was copied from a similar patch for DragonflyBSD.

However, in DragonflyBSD, load balancing is a global on/off setting and can not
be set per socket. This patch allows for simultaneous use of both the current
SO_REUSEPORT and the new SO_REUSEPORT_LB options on the same system.

Required changes to structures
Globally change so_options from 16 to 32 bit value to allow for more options.
Add hashtable in pcbinfo to hold all SO_REUSEPORT_LB sockets.

Limitations
As DragonflyBSD, a load balance group is limited to 256 pcbs
(256 programs or threads sharing the same socket).

Submitted by:	Johannes Lundberg <johanlun0@gmail.com>
Sponsored by:	Limelight Networks
Differential Revision:	https://reviews.freebsd.org/D11003
This commit is contained in:
sbruno 2018-04-23 19:51:00 +00:00 committed by Sebastian Huber
parent 341e131f7f
commit 5c636abe89
1 changed files with 3 additions and 0 deletions

View File

@ -147,6 +147,9 @@ typedef __uintptr_t uintptr_t;
#define SO_NO_OFFLOAD 0x4000 /* socket cannot be offloaded */
#define SO_NO_DDP 0x8000 /* disable direct data placement */
// XXX: so_options was only 16 bit, now globally increased to 32 bit
#define SO_REUSEPORT_LB 0x00010000 /* reuse with load balancing */
/*
* Additional options, not kept in so_options.
*/