• Bhaskar Dutta's avatar
    sctp: Sysctl configuration for IPv4 Address Scoping · 72388433
    Bhaskar Dutta authored
    This patch introduces a new sysctl option to make IPv4 Address Scoping
    configurable <draft-stewart-tsvwg-sctp-ipv4-00.txt>.
    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: default avatarBhaskar Dutta <bhaskar.dutta@globallogic.com>
    Signed-off-by: default avatarVlad Yasevich <vladislav.yasevich@hp.com>
structs.h 63.2 KB