This patch set addresses bug "Bug 95171 - "hw csum failure" message flood for ppp tunnel since upgrade to 3.16". The problem is that pppoe is being used over UDP with UDP checksusm enabled. On receive checksum conversion turns checksum-unnecessary in checksum- complete. The PPP receive functions do no properly pull the checksum over its headers, so that when an encapsulated checksums is considered the checksum-complete value is incorrect.
This patch adds skb_checksum_complete_unset which can be called in the receive path in lieu of pulling checksum complete in layer. This is useful when the packet is being modified (e.g. decompressed) and the checksum-complete value is no longer relevant. In the ppp_receive_frame we call skb_checksum_complete_unset to toss out checksum-complete. This should eliminate the reported messages. Alternatively, we could add skb_postpull_rcsum and probably special case handling for VJ compression if maintaining the checksum-complete is needed (not clear to me this is worth the effort). I haven't tested this since setting up the failure scenario doesn't seem trivial to configure. Tom Herbert (2): net: add skb_checksum_complete_unset ppp: call skb_checksum_complete_unset in ppp_receive_frame drivers/net/ppp/ppp_generic.c | 1 + include/linux/skbuff.h | 12 ++++++++++++ 2 files changed, 13 insertions(+) -- 1.8.1 -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
