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| author | Paolo Abeni <pabeni@redhat.com> | 2019-10-26 11:53:39 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-10-26 11:25:53 -0700 |
| commit | 0b834ba00ab5337e938c727e216e1f5249794717 (patch) | |
| tree | ec9938470f8f09a00dcccef74c98cd80a4bb2c72 | |
| parent | 5ff223e86f5addbfae26419cbb5d61d98f6fbf7d (diff) | |
| download | lwn-0b834ba00ab5337e938c727e216e1f5249794717.tar.gz lwn-0b834ba00ab5337e938c727e216e1f5249794717.zip | |
ipv4: fix route update on metric change.
Since commit af4d768ad28c ("net/ipv4: Add support for specifying metric
of connected routes"), when updating an IP address with a different metric,
the associated connected route is updated, too.
Still, the mentioned commit doesn't handle properly some corner cases:
$ ip addr add dev eth0 192.168.1.0/24
$ ip addr add dev eth0 192.168.2.1/32 peer 192.168.2.2
$ ip addr add dev eth0 192.168.3.1/24
$ ip addr change dev eth0 192.168.1.0/24 metric 10
$ ip addr change dev eth0 192.168.2.1/32 peer 192.168.2.2 metric 10
$ ip addr change dev eth0 192.168.3.1/24 metric 10
$ ip -4 route
192.168.1.0/24 dev eth0 proto kernel scope link src 192.168.1.0
192.168.2.2 dev eth0 proto kernel scope link src 192.168.2.1
192.168.3.0/24 dev eth0 proto kernel scope link src 192.168.2.1 metric 10
Only the last route is correctly updated.
The problem is the current test in fib_modify_prefix_metric():
if (!(dev->flags & IFF_UP) ||
ifa->ifa_flags & (IFA_F_SECONDARY | IFA_F_NOPREFIXROUTE) ||
ipv4_is_zeronet(prefix) ||
prefix == ifa->ifa_local || ifa->ifa_prefixlen == 32)
Which should be the logical 'not' of the pre-existing test in
fib_add_ifaddr():
if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
(prefix != addr || ifa->ifa_prefixlen < 32))
To properly negate the original expression, we need to change the last
logical 'or' to a logical 'and'.
Fixes: af4d768ad28c ("net/ipv4: Add support for specifying metric of connected routes")
Reported-and-suggested-by: Beniamino Galvani <bgalvani@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/ipv4/fib_frontend.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c index dde77f72e03e..71c78d223dfd 100644 --- a/net/ipv4/fib_frontend.c +++ b/net/ipv4/fib_frontend.c @@ -1148,7 +1148,7 @@ void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric) if (!(dev->flags & IFF_UP) || ifa->ifa_flags & (IFA_F_SECONDARY | IFA_F_NOPREFIXROUTE) || ipv4_is_zeronet(prefix) || - prefix == ifa->ifa_local || ifa->ifa_prefixlen == 32) + (prefix == ifa->ifa_local && ifa->ifa_prefixlen == 32)) return; /* add the new */ |