• Chris Friesen's avatar
    route: do not cache fib route info on local routes with oif · 992ce0a3
    Chris Friesen authored
    [ Upstream commit d6d5e999 ]
    
    For local routes that require a particular output interface we do not want
    to cache the result.  Caching the result causes incorrect behaviour when
    there are multiple source addresses on the interface.  The end result
    being that if the intended recipient is waiting on that interface for the
    packet he won't receive it because it will be delivered on the loopback
    interface and the IP_PKTINFO ipi_ifindex will be set to the loopback
    interface as well.
    
    This can be tested by running a program such as "dhcp_release" which
    attempts to inject a packet on a particular interface so that it is
    received by another program on the same board.  The receiving process
    should see an IP_PKTINFO ipi_ifndex value of the source interface
    (e.g., eth1) instead of the loopback interface (e.g., lo).  The packet
    will still appear on the loopback interface in tcpdump but the important
    aspect is that the CMSG info is correct.
    
    Sample dhcp_release command line:
    
       dhcp_release eth1 192.168.204.222 02:11:33:22:44:66
    Signed-off-by: default avatarAllain Legacy <allain.legacy@windriver.com>
    Signed off-by: Chris Friesen <chris.friesen@windriver.com>
    Reviewed-by: default avatarJulian Anastasov <ja@ssi.bg>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    992ce0a3
route.c 70.9 KB