linux/include
William Manley 2690048c01 net: igmp: Allow user-space configuration of igmp unsolicited report interval
Adds the new procfs knobs:

    /proc/sys/net/ipv4/conf/*/igmpv2_unsolicited_report_interval
    /proc/sys/net/ipv4/conf/*/igmpv3_unsolicited_report_interval

Which will allow userspace configuration of the IGMP unsolicited report
interval (see below) in milliseconds.  The defaults are 10000ms for IGMPv2
and 1000ms for IGMPv3 in accordance with RFC2236 and RFC3376.

Background:

If an IGMP join packet is lost you will not receive data sent to the
multicast group so if no data arrives from that multicast group in a
period of time after the IGMP join a second IGMP join will be sent.  The
delay between joins is the "IGMP Unsolicited Report Interval".

Prior to this patch this value was hard coded in the kernel to 10s for
IGMPv2 and 1s for IGMPv3.  10s is unsuitable for some use-cases, such as
IPTV as it can cause channel change to be slow in the presence of packet
loss.

This patch allows the value to be overridden from userspace for both
IGMPv2 and IGMPv3 such that it can be tuned accoding to the network.

Tested with Wireshark and a simple program to join a (non-existent)
multicast group.  The distribution of timings for the second join differ
based upon setting the procfs knobs.

igmpvX_unsolicited_report_interval is intended to follow the pattern
established by force_igmp_version, and while a procfs entry has been added
a corresponding sysctl knob has not as it is my understanding that sysctl
is deprecated[1].

[1]: http://lwn.net/Articles/247243/

Signed-off-by: William Manley <william.manley@youview.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-09 11:27:46 -07:00
..
acpi Revert "ACPI / video / i915: No ACPI backlight if firmware expects Windows 8" 2013-07-26 14:59:20 +02:00
asm-generic Merge branch 'cpuinit-delete' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2013-07-07 11:01:19 -07:00
clocksource
crypto
drm drm: fix 64 bit drm fixed point helpers 2013-07-30 17:24:13 -04:00
dt-bindings Pin control fixes for the v3.11 series: 2013-07-28 18:19:27 -07:00
keys
kvm ARM: KVM: Allow host virt timer irq to be different from guest timer virt irq 2013-06-26 10:50:02 -07:00
linux net: igmp: Allow user-space configuration of igmp unsolicited report interval 2013-08-09 11:27:46 -07:00
math-emu
media include: Convert ethernet mac address declarations to use ETH_ALEN 2013-08-02 12:33:54 -07:00
memory
misc
net ip_tunnel: embed hash list head 2013-08-07 16:47:52 -07:00
pcmcia
ras
rdma Merge branches 'af_ib', 'cxgb4', 'misc', 'mlx5', 'ocrdma', 'qib' and 'srp' into for-next 2013-07-08 11:22:11 -07:00
rxrpc
scsi [SCSI] libiscsi: Added new boot entries in the session sysfs 2013-06-26 18:04:11 -07:00
sound ASoC: More updates for v3.11 2013-06-28 13:36:22 +02:00
target target: make queue_tm_rsp() return void 2013-07-07 18:36:53 -07:00
trace This contains fixes, optimizations and some clean ups 2013-07-22 19:07:24 -07:00
uapi net: add SNMP counters tracking incoming ECN bits 2013-08-08 22:24:59 -07:00
video Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2013-07-09 16:04:31 -07:00
xen Merge branch 'for-3.11/drivers' of git://git.kernel.dk/linux-block 2013-07-22 19:02:52 -07:00
Kbuild