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| author | Jeff Dike <jdike@akamai.com> | 2020-11-12 20:58:15 -0500 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2020-11-13 14:24:39 -0800 |
| commit | 8cf8821e15cd553339a5b48ee555a0439c2b2742 (patch) | |
| tree | 13666363e35caf4ee8c97d7f765d55ea9062f32d /net/ipv6 | |
| parent | 2b5668733050fca85f0ab458c5b91732f9496a38 (diff) | |
| download | linux-8cf8821e15cd553339a5b48ee555a0439c2b2742.tar.bz2 | |
net: Exempt multicast addresses from five-second neighbor lifetime
Commit 58956317c8de ("neighbor: Improve garbage collection")
guarantees neighbour table entries a five-second lifetime. Processes
which make heavy use of multicast can fill the neighour table with
multicast addresses in five seconds. At that point, neighbour entries
can't be GC-ed because they aren't five seconds old yet, the kernel
log starts to fill up with "neighbor table overflow!" messages, and
sends start to fail.
This patch allows multicast addresses to be thrown out before they've
lived out their five seconds. This makes room for non-multicast
addresses and makes messages to all addresses more reliable in these
circumstances.
Fixes: 58956317c8de ("neighbor: Improve garbage collection")
Signed-off-by: Jeff Dike <jdike@akamai.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20201113015815.31397-1-jdike@akamai.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/ipv6')
| -rw-r--r-- | net/ipv6/ndisc.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c index 27f29b957ee7..76717478f173 100644 --- a/net/ipv6/ndisc.c +++ b/net/ipv6/ndisc.c @@ -81,6 +81,7 @@ static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb); static int pndisc_constructor(struct pneigh_entry *n); static void pndisc_destructor(struct pneigh_entry *n); static void pndisc_redo(struct sk_buff *skb); +static int ndisc_is_multicast(const void *pkey); static const struct neigh_ops ndisc_generic_ops = { .family = AF_INET6, @@ -115,6 +116,7 @@ struct neigh_table nd_tbl = { .pconstructor = pndisc_constructor, .pdestructor = pndisc_destructor, .proxy_redo = pndisc_redo, + .is_multicast = ndisc_is_multicast, .allow_add = ndisc_allow_add, .id = "ndisc_cache", .parms = { @@ -1706,6 +1708,11 @@ static void pndisc_redo(struct sk_buff *skb) kfree_skb(skb); } +static int ndisc_is_multicast(const void *pkey) +{ + return ipv6_addr_is_multicast((struct in6_addr *)pkey); +} + static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb) { struct inet6_dev *idev = __in6_dev_get(skb->dev); |