From f4105ac21a9f11f5231681239ca92ac814b5149d Mon Sep 17 00:00:00 2001 From: Andrei Vagin Date: Thu, 28 Mar 2019 11:02:23 -0700 Subject: netstack/fdbased: add generic segmentation offload (GSO) support The linux packet socket can handle GSO packets, so we can segment packets to 64K instead of the MTU which is usually 1500. Here are numbers for the nginx-1m test: runsc: 579330.01 [Kbytes/sec] received runsc-gso: 1794121.66 [Kbytes/sec] received runc: 2122139.06 [Kbytes/sec] received and for tcp_benchmark: $ tcp_benchmark --duration 15 --ideal [ 4] 0.0-15.0 sec 86647 MBytes 48456 Mbits/sec $ tcp_benchmark --client --duration 15 --ideal [ 4] 0.0-15.0 sec 2173 MBytes 1214 Mbits/sec $ tcp_benchmark --client --duration 15 --ideal --gso 65536 [ 4] 0.0-15.0 sec 19357 MBytes 10825 Mbits/sec PiperOrigin-RevId: 240809103 Change-Id: I2637f104db28b5d4c64e1e766c610162a195775a --- pkg/tcpip/header/tcp.go | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'pkg/tcpip/header') diff --git a/pkg/tcpip/header/tcp.go b/pkg/tcpip/header/tcp.go index d37d624fe..6e3ee2e50 100644 --- a/pkg/tcpip/header/tcp.go +++ b/pkg/tcpip/header/tcp.go @@ -167,6 +167,12 @@ const ( // TCPMinimumSize is the minimum size of a valid TCP packet. TCPMinimumSize = 20 + // TCPOptionsMaximumSize is the maximum size of TCP options. + TCPOptionsMaximumSize = 40 + + // TCPHeaderMaximumSize is the maximum header size of a TCP packet. + TCPHeaderMaximumSize = TCPMinimumSize + TCPOptionsMaximumSize + // TCPProtocolNumber is TCP's transport protocol number. TCPProtocolNumber tcpip.TransportProtocolNumber = 6 ) @@ -291,6 +297,11 @@ func (b TCP) EncodePartial(partialChecksum, length uint16, seqnum, acknum uint32 b.SetChecksum(^checksum) } +// TCPChecksumOffset returns offset of the checksum field. +func TCPChecksumOffset() uint16 { + return tcpChecksum +} + // ParseSynOptions parses the options received in a SYN segment and returns the // relevant ones. opts should point to the option part of the TCP Header. func ParseSynOptions(opts []byte, isAck bool) TCPSynOptions { -- cgit v1.2.3