diff options
author | Robert Shearman <rshearma@brocade.com> | 2015-12-10 19:30:49 +0000 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2015-12-12 00:43:44 -0500 |
commit | 72dcac96c7f8320caf80dfaa559331174060a1ce (patch) | |
tree | 6ebf1a477b7f842038fb96ade44df2a500d10653 /fs/stack.c | |
parent | a3e948e83a302c63f196512e253067ded6bbc832 (diff) |
mpls: don't dump RTA_VIA attribute if not specified
The problem seen is that when adding a route with a nexthop with no
via address specified, iproute2 generates bogus output:
# ip -f mpls route add 100 dev lo
# ip -f mpls route list
100 via inet 0.0.8.0 dev lo
The reason for this is that the kernel generates an RTA_VIA attribute
with the family set to AF_INET, but the via address data having zero
length. The cause of family being AF_INET is that on route insert
cfg->rc_via_table is left set to 0, which just happens to be
NEIGH_ARP_TABLE which is then translated into AF_INET.
iproute2 doesn't validate the length prior to printing and so prints
garbage. Although it could be fixed to do the validation, I would
argue that AF_INET addresses should always be exactly 4 bytes so the
kernel is really giving userspace bogus data.
Therefore, avoid generating the RTA_VIA attribute when dumping the
route if the via address wasn't specified on add/modify. This is
indicated by NEIGH_ARP_TABLE and a zero via address length - if the
user specified a via address the address length would have been
validated such that it was 4 bytes. Although this is a change in
behaviour that is visible to userspace, I believe that what was
generated before was invalid and as such userspace wouldn't be
expecting it.
Signed-off-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'fs/stack.c')
0 files changed, 0 insertions, 0 deletions