net/sched: fix corrupted L2 header with MPLS 'push' and 'pop' actions
the following script: # tc qdisc add dev eth0 clsact # tc filter add dev eth0 egress protocol ip matchall \ > action mpls push protocol mpls_uc label 0x355aa bos 1 causes corruption of all IP packets transmitted by eth0. On TC egress, we can't rely on the value of skb->mac_len, because it's 0 and a MPLS 'push' operation will result in an overwrite of the first 4 octets in the packet L2 header (e.g. the Destination Address if eth0 is an Ethernet); the same error pattern is present also in the MPLS 'pop' operation. Fix this error in act_mpls data plane, computing 'mac_len' as the difference between the network header and the mac header (when not at TC ingress), and use it in MPLS 'push'/'pop' core functions. v2: unbreak 'make htmldocs' because of missing documentation of 'mac_len' in skb_mpls_pop(), reported by kbuild test robot CC: Lorenzo Bianconi <lorenzo@kernel.org> Fixes: 2a2ea508 ("net: sched: add mpls manipulation actions to TC") Reviewed-by:Simon Horman <simon.horman@netronome.com> Acked-by:
John Hurley <john.hurley@netronome.com> Signed-off-by:
Davide Caratti <dcaratti@redhat.com> Signed-off-by:
David S. Miller <davem@davemloft.net>
parent
dedc5a08
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