kernel_optimize_test/net/ipv6
Michal Kubeček e5fd387ad5 ipv6: do not overwrite inetpeer metrics prematurely
If an IPv6 host route with metrics exists, an attempt to add a
new route for the same target with different metrics fails but
rewrites the metrics anyway:

12sp0:~ # ip route add fec0::1 dev eth0 rto_min 1000
12sp0:~ # ip -6 route show
fe80::/64 dev eth0  proto kernel  metric 256
fec0::1 dev eth0  metric 1024  rto_min lock 1s
12sp0:~ # ip route add fec0::1 dev eth0 rto_min 1500
RTNETLINK answers: File exists
12sp0:~ # ip -6 route show
fe80::/64 dev eth0  proto kernel  metric 256
fec0::1 dev eth0  metric 1024  rto_min lock 1.5s

This is caused by all IPv6 host routes using the metrics in
their inetpeer (or the shared default). This also holds for the
new route created in ip6_route_add() which shares the metrics
with the already existing route and thus ip6_route_add()
rewrites the metrics even if the new route ends up not being
used at all.

Another problem is that old metrics in inetpeer can reappear
unexpectedly for a new route, e.g.

12sp0:~ # ip route add fec0::1 dev eth0 rto_min 1000
12sp0:~ # ip route del fec0::1
12sp0:~ # ip route add fec0::1 dev eth0
12sp0:~ # ip route change fec0::1 dev eth0 hoplimit 10
12sp0:~ # ip -6 route show
fe80::/64 dev eth0  proto kernel  metric 256
fec0::1 dev eth0  metric 1024  hoplimit 10 rto_min lock 1s

Resolve the first problem by moving the setting of metrics down
into fib6_add_rt2node() to the point we are sure we are
inserting the new route into the tree. Second problem is
addressed by introducing new flag DST_METRICS_FORCE_OVERWRITE
which is set for a new host route in ip6_route_add() and makes
ipv6_cow_metrics() always overwrite the metrics in inetpeer
(even if they are not "new"); it is reset after that.

v5: use a flag in _metrics member rather than one in flags

v4: fix a typo making a condition always true (thanks to Hannes
Frederic Sowa)

v3: rewritten based on David Miller's idea to move setting the
metrics (and allocation in non-host case) down to the point we
already know the route is to be inserted. Also rebased to
net-next as it is quite late in the cycle.

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-27 15:09:07 -04:00
..
netfilter
addrconf_core.c
addrconf.c ipv6: Avoid unnecessary temporary addresses being generated 2014-03-13 15:49:14 -04:00
addrlabel.c
af_inet6.c
ah6.c ah6: Use the IPsec protocol multiplexer API 2014-03-14 07:28:07 +01:00
anycast.c
datagram.c
esp6.c esp6: Use the IPsec protocol multiplexer API 2014-03-14 07:28:07 +01:00
exthdrs_core.c ipv6: ipv6_find_hdr restore prev functionality 2014-02-27 18:27:26 -05:00
exthdrs_offload.c ipv6: Fix exthdrs offload registration. 2014-03-06 16:35:55 -05:00
exthdrs.c
fib6_rules.c
icmp.c
inet6_connection_sock.c
inet6_hashtables.c
ip6_checksum.c ipv6: log src and dst along with "udp checksum is 0" 2014-02-26 15:46:25 -05:00
ip6_fib.c ipv6: do not overwrite inetpeer metrics prematurely 2014-03-27 15:09:07 -04:00
ip6_flowlabel.c
ip6_gre.c
ip6_icmp.c
ip6_input.c
ip6_offload.c
ip6_offload.h
ip6_output.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-03-25 20:29:20 -04:00
ip6_tunnel.c net: Replace u64_stats_fetch_begin_bh to u64_stats_fetch_begin_irq 2014-03-14 22:41:36 -04:00
ip6_vti.c vti6: Enable namespace changing 2014-03-14 07:28:09 +01:00
ip6mr.c ip6mr: fix mfc notification flags 2014-03-20 16:24:28 -04:00
ipcomp6.c ipcomp6: Use the IPsec protocol multiplexer API 2014-03-14 07:28:07 +01:00
ipv6_sockglue.c ipv6: yet another new IPV6_MTU_DISCOVER option IPV6_PMTUDISC_OMIT 2014-02-26 15:51:01 -05:00
Kconfig
Makefile xfrm6: Add IPsec protocol multiplexer 2014-03-14 07:28:07 +01:00
mcast.c
mip6.c
ndisc.c
netfilter.c
output_core.c inet: remove now unused flag DST_NOPEER 2014-03-06 13:15:52 -05:00
ping.c net: ipv6: ping: Use socket mark in routing lookup 2014-02-27 16:08:46 -05:00
proc.c
protocol.c
raw.c
reassembly.c
route.c ipv6: do not overwrite inetpeer metrics prematurely 2014-03-27 15:09:07 -04:00
sit.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-03-05 20:32:02 -05:00
syncookies.c
sysctl_net_ipv6.c
tcp_ipv6.c tcp: snmp stats for Fast Open, SYN rtx, and data pkts 2014-03-03 15:58:03 -05:00
tcpv6_offload.c
tunnel6.c
udp_impl.h
udp_offload.c
udp.c
udplite.c
xfrm6_input.c
xfrm6_mode_beet.c
xfrm6_mode_ro.c
xfrm6_mode_transport.c
xfrm6_mode_tunnel.c xfrm6: Remove xfrm_tunnel_notifier 2014-03-14 07:28:08 +01:00
xfrm6_output.c
xfrm6_policy.c xfrm6: Add IPsec protocol multiplexer 2014-03-14 07:28:07 +01:00
xfrm6_protocol.c xfrm6: Add IPsec protocol multiplexer 2014-03-14 07:28:07 +01:00
xfrm6_state.c
xfrm6_tunnel.c