From 723884339f90a9c420783135168cc1045750eb5d Mon Sep 17 00:00:00 2001 From: Bhaskar Dutta Date: Thu, 3 Sep 2009 17:25:47 +0530 Subject: sctp: Sysctl configuration for IPv4 Address Scoping This patch introduces a new sysctl option to make IPv4 Address Scoping configurable . In networking environments where DNAT rules in iptables prerouting chains convert destination IP's to link-local/private IP addresses, SCTP connections fail to establish as the INIT chunk is dropped by the kernel due to address scope match failure. For example to support overlapping IP addresses (same IP address with different vlan id) a Layer-5 application listens on link local IP's, and there is a DNAT rule that maps the destination IP to a link local IP. Such applications never get the SCTP INIT if the address-scoping draft is strictly followed. This sysctl configuration allows SCTP to function in such unconventional networking environments. Sysctl options: 0 - Disable IPv4 address scoping draft altogether 1 - Enable IPv4 address scoping (default, current behavior) 2 - Enable address scoping but allow IPv4 private addresses in init/init-ack 3 - Enable address scoping but allow IPv4 link local address in init/init-ack Signed-off-by: Bhaskar Dutta Signed-off-by: Vlad Yasevich --- Documentation/networking/ip-sysctl.txt | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'Documentation/networking') diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index 4e9c6d7b4efc..fbe427a6580c 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -1297,6 +1297,16 @@ sctp_rmem - vector of 3 INTEGERs: min, default, max sctp_wmem - vector of 3 INTEGERs: min, default, max See tcp_wmem for a description. +addr_scope_policy - INTEGER + Control IPv4 address scoping - draft-stewart-tsvwg-sctp-ipv4-00 + + 0 - Disable IPv4 address scoping + 1 - Enable IPv4 address scoping + 2 - Follow draft but allow IPv4 private addresses + 3 - Follow draft but allow IPv4 link local addresses + + Default: 1 + /proc/sys/net/core/* dev_weight - INTEGER -- cgit v1.2.3