linux_dsm_epyc7002/net/ipv6
Roopa Prabhu 6b9ea5a64e ipv6: fix multipath route replace error recovery
Problem:
The ecmp route replace support for ipv6 in the kernel, deletes the
existing ecmp route too early, ie when it installs the first nexthop.
If there is an error in installing the subsequent nexthops, its too late
to recover the already deleted existing route leaving the fib
in an inconsistent state.

This patch reduces the possibility of this by doing the following:
a) Changes the existing multipath route add code to a two stage process:
  build rt6_infos + insert them
	ip6_route_add rt6_info creation code is moved into
	ip6_route_info_create.
b) This ensures that most errors are caught during building rt6_infos
  and we fail early
c) Separates multipath add and del code. Because add needs the special
  two stage mode in a) and delete essentially does not care.
d) In any event if the code fails during inserting a route again, a
  warning is printed (This should be unlikely)

Before the patch:
$ip -6 route show
3000:1000:1000:1000::2 via fe80::202:ff:fe00:b dev swp49s0 metric 1024
3000:1000:1000:1000::2 via fe80::202:ff:fe00:d dev swp49s1 metric 1024
3000:1000:1000:1000::2 via fe80::202:ff:fe00:f dev swp49s2 metric 1024

/* Try replacing the route with a duplicate nexthop */
$ip -6 route change 3000:1000:1000:1000::2/128 nexthop via
fe80::202:ff:fe00:b dev swp49s0 nexthop via fe80::202:ff:fe00:d dev
swp49s1 nexthop via fe80::202:ff:fe00:d dev swp49s1
RTNETLINK answers: File exists

$ip -6 route show
/* previously added ecmp route 3000:1000:1000:1000::2 dissappears from
 * kernel */

After the patch:
$ip -6 route show
3000:1000:1000:1000::2 via fe80::202:ff:fe00:b dev swp49s0 metric 1024
3000:1000:1000:1000::2 via fe80::202:ff:fe00:d dev swp49s1 metric 1024
3000:1000:1000:1000::2 via fe80::202:ff:fe00:f dev swp49s2 metric 1024

/* Try replacing the route with a duplicate nexthop */
$ip -6 route change 3000:1000:1000:1000::2/128 nexthop via
fe80::202:ff:fe00:b dev swp49s0 nexthop via fe80::202:ff:fe00:d dev
swp49s1 nexthop via fe80::202:ff:fe00:d dev swp49s1
RTNETLINK answers: File exists

$ip -6 route show
3000:1000:1000:1000::2 via fe80::202:ff:fe00:b dev swp49s0 metric 1024
3000:1000:1000:1000::2 via fe80::202:ff:fe00:d dev swp49s1 metric 1024
3000:1000:1000:1000::2 via fe80::202:ff:fe00:f dev swp49s2 metric 1024

Fixes: 2759647247 ("ipv6: fix ECMP route replacement")
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-09 14:07:50 -07:00
..
netfilter netfilter: nf_dup{4, 6}: fix build error when nf_conntrack disabled 2015-09-02 16:28:06 -07:00
addrconf_core.c ipv6: change ipv6_stub_impl.ipv6_dst_lookup to take net argument 2015-07-31 15:21:30 -07:00
addrconf.c net: Optimize snmp stat aggregation by walking all the percpu data at once 2015-08-30 21:48:58 -07:00
addrlabel.c netlink: implement nla_put_in_addr and nla_put_in6_addr 2015-03-31 13:58:35 -04:00
af_inet6.c ipv6: Disable flowlabel state ranges by default 2015-07-31 17:07:11 -07:00
ah6.c ah6: fix error return code 2015-08-25 13:37:31 -07:00
anycast.c ipv6: coding style: comparison for equality with NULL 2015-03-31 13:51:54 -04:00
datagram.c net: Set sk_txhash from a random number 2015-07-29 22:44:04 -07:00
esp6.c esp6: Switch to new AEAD interface 2015-05-28 11:23:20 +08:00
exthdrs_core.c ipv6: coding style: comparison for equality with NULL 2015-03-31 13:51:54 -04:00
exthdrs_offload.c ipv6: fix exthdrs offload registration in out_rt path 2015-09-02 15:31:00 -07:00
exthdrs.c ipv6: use flag instead of u16 for hop in inet6_skb_parm 2015-07-09 15:06:59 -07:00
fib6_rules.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-04-06 22:34:15 -04:00
icmp.c ipv6: change ipv6_stub_impl.ipv6_dst_lookup to take net argument 2015-07-31 15:21:30 -07:00
ila.c ila: Precompute checksum difference for translations 2015-08-24 10:34:40 -07:00
inet6_connection_sock.c net: convert syn_wait_lock to a spinlock 2015-03-23 16:52:26 -04:00
inet6_hashtables.c inet: inet_twsk_deschedule factorization 2015-07-09 15:12:20 -07:00
ip6_checksum.c udp: Generic functions to set checksum 2014-06-04 22:46:38 -07:00
ip6_fib.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-08-21 11:44:04 -07:00
ip6_flowlabel.c ipv6: Flow label state ranges 2015-05-03 21:58:01 -04:00
ip6_gre.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-08-27 21:45:31 -07:00
ip6_icmp.c ipv6: White-space cleansing : Line Layouts 2014-08-24 22:37:52 -07:00
ip6_input.c ipv6: fix crash over flow-based vxlan device 2015-07-26 20:54:56 -07:00
ip6_offload.c Revert "sit: Add gro callbacks to sit_offload" 2015-07-20 16:52:28 -07:00
ip6_offload.h ipv6: Pull IPv6 GSO registration out of the module 2012-11-15 17:39:24 -05:00
ip6_output.c ipv6: Call skb_get_hash_flowi6 to get skb->hash in ip6_make_flowlabel 2015-07-31 17:07:11 -07:00
ip6_tunnel.c ipv6: Implement different admin modes for automatic flow labels 2015-07-31 17:07:11 -07:00
ip6_udp_tunnel.c vxlan: do not receive IPv4 packets on IPv6 socket 2015-08-29 13:07:54 -07:00
ip6_vti.c vti6: Add pmtu handling to vti6_xmit. 2015-06-01 16:03:43 -07:00
ip6mr.c net/ipv6: Correct PIM6 mrt_lock handling 2015-09-05 17:31:30 -07:00
ipcomp6.c ipv6: White-space cleansing : Structure layouts 2014-08-24 22:37:52 -07:00
ipv6_sockglue.c ipv6: coding style: comparison for equality with NULL 2015-03-31 13:51:54 -04:00
Kconfig net: Identifier Locator Addressing module 2015-08-17 21:33:06 -07:00
Makefile net: Identifier Locator Addressing module 2015-08-17 21:33:06 -07:00
mcast_snoop.c net: fix wrong skb_get() usage / crash in IGMP/MLD parsing code 2015-08-13 17:08:39 -07:00
mcast.c netfilter: Pass socket pointer down through okfn(). 2015-04-07 15:25:55 -04:00
mip6.c net: Convert LIMIT_NETDEBUG to net_dbg_ratelimited 2014-11-11 14:10:31 -05:00
ndisc.c ipv6: send only one NEWLINK when RA causes changes 2015-08-31 21:20:29 -07:00
netfilter.c netfilter: bridge: forward IPv6 fragmented packets 2015-06-12 14:10:12 +02:00
output_core.c netfilter: don't pull include/linux/netfilter.h from netns headers 2015-06-18 21:14:31 +02:00
ping.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-03-09 23:38:02 -04:00
proc.c udp: Increment UDP_MIB_IGNOREDMULTI for arriving unmatched multicasts 2014-11-07 15:45:50 -05:00
protocol.c net: Export inet_offloads and inet6_offloads 2014-09-19 17:15:31 -04:00
raw.c ipv6: Nonlocal bind 2015-07-09 21:09:10 -07:00
reassembly.c inet: frags: remove INET_FRAG_EVICTED and use list_evictor for the test 2015-07-26 21:00:15 -07:00
route.c ipv6: fix multipath route replace error recovery 2015-09-09 14:07:50 -07:00
sit.c ip_gre: Add support to collect tunnel metadata. 2015-08-10 14:03:54 -07:00
syncookies.c tcp: get_cookie_sock() consolidation 2015-06-07 15:19:52 -07:00
sysctl_net_ipv6.c ipv6: Implement different admin modes for automatic flow labels 2015-07-31 17:07:11 -07:00
tcp_ipv6.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-08-13 16:23:11 -07:00
tcpv6_offload.c tcp: cleanup static functions 2015-02-28 16:56:51 -05:00
tunnel6.c ipv6: White-space cleansing : gaps between function and symbol export 2014-08-24 22:37:52 -07:00
udp_impl.h net: Remove iocb argument from sendmsg and recvmsg 2015-03-02 13:06:31 -05:00
udp_offload.c ipv6: hash net ptr into fragmentation bucket selection 2015-03-25 14:07:04 -04:00
udp.c ipv6: trivial whitespace fix 2015-08-17 14:34:48 -07:00
udplite.c net: Eliminate no_check from protosw 2014-05-23 16:28:53 -04:00
xfrm6_input.c netfilter: Pass socket pointer down through okfn(). 2015-04-07 15:25:55 -04:00
xfrm6_mode_beet.c xfrm: simplify xfrm_address_t use 2015-03-31 13:58:35 -04:00
xfrm6_mode_ro.c ipv4/ipv6: Fix FSF address in file headers 2013-12-06 12:37:56 -05:00
xfrm6_mode_transport.c
xfrm6_mode_tunnel.c xfrm6: Fix IPv6 ECN decapsulation 2015-08-11 12:41:34 +02:00
xfrm6_output.c netfilter: Pass socket pointer down through okfn(). 2015-04-07 15:25:55 -04:00
xfrm6_policy.c xfrm: Use VRF master index if output device is enslaved 2015-08-25 11:25:09 -07:00
xfrm6_protocol.c xfrm6: Properly handle unsupported protocols 2014-05-06 07:08:38 +02:00
xfrm6_state.c ipv6: White-space cleansing : Line Layouts 2014-08-24 22:37:52 -07:00
xfrm6_tunnel.c ipv6: White-space cleansing : gaps between function and symbol export 2014-08-24 22:37:52 -07:00