From 184d4d42033d5c111276e4eef9ea273c2e114d18 Mon Sep 17 00:00:00 2001 From: Zhang Chen Date: Tue, 18 Apr 2017 10:20:19 +0800 Subject: [PATCH] COLO-compare: Optimize tcp compare for option field In this patch we support packet that have tcp options field. Add tcp options field check, If the packet have options field we just skip it and compare tcp payload, Avoid unnecessary checkpoint, optimize performance. Signed-off-by: Zhang Chen Signed-off-by: Jason Wang --- net/colo-compare.c | 27 ++++++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-) diff --git a/net/colo-compare.c b/net/colo-compare.c index 9b09cfc9c0..4ab80b1cbb 100644 --- a/net/colo-compare.c +++ b/net/colo-compare.c @@ -233,7 +233,32 @@ static int colo_packet_compare_tcp(Packet *spkt, Packet *ppkt) spkt->ip->ip_sum = ppkt->ip->ip_sum; } - if (ptcp->th_sum == stcp->th_sum) { + /* + * Check tcp header length for tcp option field. + * th_off > 5 means this tcp packet have options field. + * The tcp options maybe always different. + * for example: + * From RFC 7323. + * TCP Timestamps option (TSopt): + * Kind: 8 + * + * Length: 10 bytes + * + * +-------+-------+---------------------+---------------------+ + * |Kind=8 | 10 | TS Value (TSval) |TS Echo Reply (TSecr)| + * +-------+-------+---------------------+---------------------+ + * 1 1 4 4 + * + * In this case the primary guest's timestamp always different with + * the secondary guest's timestamp. COLO just focus on payload, + * so we just need skip this field. + */ + if (ptcp->th_off > 5) { + ptrdiff_t tcp_offset; + tcp_offset = ppkt->transport_header - (uint8_t *)ppkt->data + + (ptcp->th_off * 4); + res = colo_packet_compare_common(ppkt, spkt, tcp_offset); + } else if (ptcp->th_sum == stcp->th_sum) { res = colo_packet_compare_common(ppkt, spkt, ETH_HLEN); } else { res = -1;