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| author |   David Ahern <dsahern@gmail.com> | 2019-04-16 17:31:43 -0700 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2019-04-17 23:19:07 -0700 |
| commit | b8fb1ab46169ac016a8552a6455bb0bfc401f8e2 (patch) | |
| tree | a7d8430a9044e9e3203915f401e68abfd6e30c31 /net/core | |
| parent | Merge branch 'ipv6-Use-fib6_result-for-fib_lookups' (diff) | |
| download | linux-dev-b8fb1ab46169ac016a8552a6455bb0bfc401f8e2.tar.xz linux-dev-b8fb1ab46169ac016a8552a6455bb0bfc401f8e2.zip | |
net ipv6: Prevent neighbor add if protocol is disabled on device
Disabling IPv6 on an interface removes existing entries but nothing prevents
new entries from being manually added. To that end, add a new neigh_table
operation, allow_add, that is called on RTM_NEWNEIGH to see if neighbor
entries are allowed on a given device. If IPv6 is disabled on the device,
allow_add returns false and passes a message back to the user via extack.
$ echo 1 > /proc/sys/net/ipv6/conf/eth1/disable_ipv6
$ ip -6 neigh add fe80::4c88:bff:fe21:2704 dev eth1 lladdr de:ad:be:ef:01:01
Error: IPv6 is disabled on this device.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/neighbour.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/net/core/neighbour.c b/net/core/neighbour.c index 30f6fd8f68e0..997cfa8f99ba 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -1920,6 +1920,11 @@ static int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh, goto out; } + if (tbl->allow_add && !tbl->allow_add(dev, extack)) { + err = -EINVAL; + goto out; + } + neigh = neigh_lookup(tbl, dst, dev); if (neigh == NULL) { bool exempt_from_gc; |