]> git.baikalelectronics.ru Git - kernel.git/commit
udp: Avoid post-GRO UDP checksum recalculation
authorSean Tranchetti <stranche@codeaurora.org>
Tue, 28 May 2019 18:22:54 +0000 (12:22 -0600)
committerDavid S. Miller <davem@davemloft.net>
Thu, 30 May 2019 18:10:39 +0000 (11:10 -0700)
commitd080bbf79485bafbb711f5ea3aad791bdb655d43
tree2fa99b8df392eab2bcc926e095f6b71998a49b3f
parent379bddde9a435f946aa0431a2722337c3d0bb66f
udp: Avoid post-GRO UDP checksum recalculation

Currently, when resegmenting an unexpected UDP GRO packet, the full UDP
checksum will be calculated for every new SKB created by skb_segment()
because the netdev features passed in by udp_rcv_segment() lack any
information about checksum offload capabilities.

Usually, we have no need to perform this calculation again, as
  1) The GRO implementation guarantees that any packets making it to the
     udp_rcv_segment() function had correct checksums, and, more
     importantly,
  2) Upon the successful return of udp_rcv_segment(), we immediately pull
     the UDP header off and either queue the segment to the socket or
     hand it off to a new protocol handler.

Unless userspace has set the IP_CHECKSUM sockopt to indicate that they
want the final checksum values, we can pass the needed netdev feature
flags to __skb_gso_segment() to avoid checksumming each segment in
skb_segment().

Fixes: c1b82510d8bc ("udp: cope with UDP GRO packet misdirection")
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: Sean Tranchetti <stranche@codeaurora.org>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
include/net/udp.h