Harmonize tcp_v4_rcv() and tcp_v6_rcv() -- better document tcp doff and header length assumptions, and carefully compare implementations. Reduces multiply/shifts, marginally improving speed. Removes redundant tcp header length checks before checksumming. Instead, assumes (and documents) that any backlog processing and transform policies will carefully preserve the header, and will ensure the socket buffer length remains >= the header size. Stand-alone patch, originally developed for TCPCT. Signed-off-by: William.Allen.Simpson@gmail.com CC: Andi Kleen --- include/net/xfrm.h | 7 ++++++ net/ipv4/tcp_ipv4.c | 45 +++++++++++++++++++++----------------- net/ipv6/tcp_ipv6.c | 59 ++++++++++++++++++++++++++++---------------------- 3 files changed, 65 insertions(+), 46 deletions(-)