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From: | Zhang Chen |
Subject: | Re: [Qemu-devel] [PATCH v2 3/3] filter-rewriter: skip net_checksum_calculate() while offset = 0 |
Date: | Mon, 27 Feb 2017 11:44:15 +0800 |
User-agent: | Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 |
On 02/27/2017 09:36 AM, Hailiang Zhang wrote:
On 2017/2/24 16:08, Zhang Chen wrote:On 02/22/2017 11:46 AM, zhanghailiang wrote:While the offset of packets's sequence for primary side andsecondary side is zero, it is unnecessary to call net_checksum_calculate()to recalculate the checksume value of packets. Signed-off-by: zhanghailiang <address@hidden> --- net/filter-rewriter.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) diff --git a/net/filter-rewriter.c b/net/filter-rewriter.c index 7e7ec35..c9a6d43 100644 --- a/net/filter-rewriter.c +++ b/net/filter-rewriter.c@@ -93,10 +93,12 @@ static int handle_primary_tcp_pkt(RewriterState *rf,conn->offset -= (ntohl(tcp_pkt->th_ack) - 1); conn->syn_flag = 0; } - /* handle packets to the secondary from the primary */- tcp_pkt->th_ack = htonl(ntohl(tcp_pkt->th_ack) + conn->offset);+ if (conn->offset) {This is wrong, conn->offset maybe is a negative value(like -1000), So you can change here to "if (conn->offset == 0) {"Er, if it is a negative value, it can still go into this if (conn->offset)branch, and we need to adjust the checksum value in this case.
Sorry, I misunderstand it, ignore. Thanks Zhang Chen
+ /* handle packets to the secondary from the primary */+ tcp_pkt->th_ack = htonl(ntohl(tcp_pkt->th_ack) + conn->offset);- net_checksum_calculate((uint8_t *)pkt->data, pkt->size); + net_checksum_calculate((uint8_t *)pkt->data, pkt->size); + } /* * Case 1:* The *server* side of this connect is VM, *client* tries to close @@ -112,7 +114,6 @@ static int handle_primary_tcp_pkt(RewriterState *rf,*/ if ((conn->tcp_state == TCPS_LAST_ACK) && (ntohl(tcp_pkt->th_ack) == (conn->fin_ack_seq + 1))) { - fprintf(stderr, "Remove conn "Here need fix.OK.g_hash_table_remove(rf->connection_track_table, key); } }@@ -159,10 +160,13 @@ static int handle_secondary_tcp_pkt(RewriterState *rf,} if ((tcp_pkt->th_flags & (TH_ACK | TH_SYN)) == TH_ACK) { - /* handle packets to the primary from the secondary*/- tcp_pkt->th_seq = htonl(ntohl(tcp_pkt->th_seq) - conn->offset);+ /* Only need to adjust seq while offset is Non-zero */ + if (conn->offset) {Refer to the above comments. Thanks Zhang Chen+ /* handle packets to the primary from the secondary*/+ tcp_pkt->th_seq = htonl(ntohl(tcp_pkt->th_seq) - conn->offset);- net_checksum_calculate((uint8_t *)pkt->data, pkt->size); + net_checksum_calculate((uint8_t *)pkt->data, pkt->size); + } /* * Case 2:* The *server* side of this connect is VM, *server* tries to close.
-- Thanks Zhang Chen
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