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| author |   Lorenzo Colitti <lorenzo@google.com> | 2018-01-11 18:36:26 +0900 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2018-01-15 13:53:30 -0500 |
| commit | 6503a30440962f1e1ccb8868816b4e18201218d4 (patch) | |
| tree | 7a806e0521b02ee9b82dd0debb708c7481954986 /net | |
| parent | netlink: extack needs to be reset each time through loop (diff) | |
| download | linux-dev-6503a30440962f1e1ccb8868816b4e18201218d4.tar.xz linux-dev-6503a30440962f1e1ccb8868816b4e18201218d4.zip | |
net: ipv4: Make "ip route get" match iif lo rules again.
Commit 3765d35ed8b9 ("net: ipv4: Convert inet_rtm_getroute to rcu
versions of route lookup") broke "ip route get" in the presence
of rules that specify iif lo.
Host-originated traffic always has iif lo, because
ip_route_output_key_hash and ip6_route_output_flags set the flow
iif to LOOPBACK_IFINDEX. Thus, putting "iif lo" in an ip rule is a
convenient way to select only originated traffic and not forwarded
traffic.
inet_rtm_getroute used to match these rules correctly because
even though it sets the flow iif to 0, it called
ip_route_output_key which overwrites iif with LOOPBACK_IFINDEX.
But now that it calls ip_route_output_key_hash_rcu, the ifindex
will remain 0 and not match the iif lo in the rule. As a result,
"ip route get" will return ENETUNREACH.
Fixes: 3765d35ed8b9 ("net: ipv4: Convert inet_rtm_getroute to rcu versions of route lookup")
Tested: https://android.googlesource.com/kernel/tests/+/master/net/test/multinetwork_test.py passes again
Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/route.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 43b69af242e1..4e153b23bcec 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -2762,6 +2762,7 @@ static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, if (err == 0 && rt->dst.error) err = -rt->dst.error; } else { + fl4.flowi4_iif = LOOPBACK_IFINDEX; rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb); err = 0; if (IS_ERR(rt)) |