CVS commit: [netbsd-10] src/sys/netinet

["Martin Husemann" <martin%netbsd.org@localhost>]

Module Name:    src
Committed By:   martin
Date:           Mon Jul 14 18:41:06 UTC 2025

Modified Files:
        src/sys/netinet [netbsd-10]: ip_input.c

Log Message:
Pull up following revision(s) (requested by ozaki-r in ticket #1137):

        sys/netinet/ip_input.c: revision 1.405

in: avoid packet looping on incoming packets destining to an initializing
address

The initialization of an IPv4 address is done by adding a connected route and
a local route (if necessary), and then publishing itself by adding it to the
global list (and the global hashtable).  Thus, there can exist a route with an
address that is not published.  This inconsistent state allows an incoming
packet destining to one of a host address which is not published but has a
local route to be forwarded and routed to a loopback interface.  This results
in forwarding the packet back to ip_input, that is, packet looping.

To avoid the situation, prohibit packets being forwarded via a local route.

This is a workaround for "IPv4 address initialization atomicity" in
doc/TODO.smpnet.


To generate a diff of this commit:
cvs rdiff -u -r1.402 -r1.402.4.1 src/sys/netinet/ip_input.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.