diff options
author | Paolo Abeni <pabeni@redhat.com> | 2017-10-19 16:07:11 +0200 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2017-10-21 01:39:10 +0100 |
commit | 1859bac04fb696b858dbbff59503c945ec871bd9 (patch) | |
tree | 50297ab528d0e1eacc1ec9f34f1698500327c263 /net/ipv6 | |
parent | b886d5f2f2906a866e33212734d204dfe35d50d9 (diff) | |
download | linux-1859bac04fb696b858dbbff59503c945ec871bd9.tar.bz2 |
ipv6: remove from fib tree aged out RTF_CACHE dst
The commit 2b760fcf5cfb ("ipv6: hook up exception table to store
dst cache") partially reverted the commit 1e2ea8ad37be ("ipv6: set
dst.obsolete when a cached route has expired").
As a result, RTF_CACHE dst referenced outside the fib tree will
not be removed until the next sernum change; dst_check() does not
fail on aged-out dst, and dst->__refcnt can't decrease: the aged
out dst will stay valid for a potentially unlimited time after the
timeout expiration.
This change explicitly removes RTF_CACHE dst from the fib tree when
aged out. The rt6_remove_exception() logic will then obsolete the
dst and other entities will drop the related reference on next
dst_check().
pMTU exceptions are not aged-out, and are removed from the exception
table only when the - usually considerably longer - ip6_rt_mtu_expires
timeout expires.
v1 -> v2:
- do not touch dst.obsolete in rt6_remove_exception(), not needed
v2 -> v3:
- take care of pMTU exceptions, too
Fixes: 2b760fcf5cfb ("ipv6: hook up exception table to store dst cache")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6')
-rw-r--r-- | net/ipv6/route.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/net/ipv6/route.c b/net/ipv6/route.c index efecdcff5055..074fac966018 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -1575,7 +1575,13 @@ static void rt6_age_examine_exception(struct rt6_exception_bucket *bucket, { struct rt6_info *rt = rt6_ex->rt6i; - if (atomic_read(&rt->dst.__refcnt) == 1 && + /* we are pruning and obsoleting aged-out and non gateway exceptions + * even if others have still references to them, so that on next + * dst_check() such references can be dropped. + * EXPIRES exceptions - e.g. pmtu-generated ones are pruned when + * expired, independently from their aging, as per RFC 8201 section 4 + */ + if (!(rt->rt6i_flags & RTF_EXPIRES) && time_after_eq(now, rt->dst.lastuse + gc_args->timeout)) { RT6_TRACE("aging clone %p\n", rt); rt6_remove_exception(bucket, rt6_ex); @@ -1595,6 +1601,10 @@ static void rt6_age_examine_exception(struct rt6_exception_bucket *bucket, rt6_remove_exception(bucket, rt6_ex); return; } + } else if (__rt6_check_expired(rt)) { + RT6_TRACE("purging expired route %p\n", rt); + rt6_remove_exception(bucket, rt6_ex); + return; } gc_args->more++; } |