• Xin Long's avatar
    ipv6: set dst.obsolete when a cached route has expired · 1e2ea8ad
    Xin Long authored
    Now it doesn't check for the cached route expiration in ipv6's
    dst_ops->check(), because it trusts dst_gc that would clean the
    cached route up when it's expired.
    
    The problem is in dst_gc, it would clean the cached route only
    when it's refcount is 1. If some other module (like xfrm) keeps
    holding it and the module only release it when dst_ops->check()
    fails.
    
    But without checking for the cached route expiration, .check()
    may always return true. Meanwhile, without releasing the cached
    route, dst_gc couldn't del it. It will cause this cached route
    never to expire.
    
    This patch is to set dst.obsolete with DST_OBSOLETE_KILL in .gc
    when it's expired, and check obsolete != DST_OBSOLETE_FORCE_CHK
    in .check.
    
    Note that this is even needed when ipv6 dst_gc timer is removed
    one day. It would set dst.obsolete in .redirect and .update_pmtu
    instead, and check for cached route expiration when getting it,
    just like what ipv4 route does.
    Reported-by: default avatarJianlin Shi <jishi@redhat.com>
    Signed-off-by: default avatarXin Long <lucien.xin@gmail.com>
    Acked-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    1e2ea8ad
route.c 101 KB