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2018-01-29colo: compare the packet based on the tcp sequence numberMao Zhongyi
Packet size some time different or when network is busy. Based on same payload size, but TCP protocol can not guarantee send the same one packet in the same way, like that: We send this payload: ------------------------------ | header |1|2|3|4|5|6|7|8|9|0| ------------------------------ primary: ppkt1: ---------------- | header |1|2|3| ---------------- ppkt2: ------------------------ | header |4|5|6|7|8|9|0| ------------------------ secondary: spkt1: ------------------------------ | header |1|2|3|4|5|6|7|8|9|0| ------------------------------ In the original method, ppkt1 and ppkt2 are different in size and spkt1, so they can't compare and trigger the checkpoint. I have tested FTP get 200M and 1G file many times, I found that the performance was less than 1% of the native. Now I reconstructed the comparison of TCP packets based on the TCP sequence number. first of all, ppkt1 and spkt1 have the same starting sequence number, so they can compare, even though their length is different. And then ppkt1 with a smaller payload length is used as the comparison length, if the payload is same, send out the ppkt1 and record the offset(the length of ppkt1 payload) in spkt1. The next comparison, ppkt2 and spkt1 can be compared from the recorded position of spkt1. like that: ---------------- | header |1|2|3| ppkt1 ---------|-----| | | ---------v-----v-------------- | header |1|2|3|4|5|6|7|8|9|0| spkt1 ---------------|\------------| | \offset | ---------v-------------v | header |4|5|6|7|8|9|0| ppkt2 ------------------------ In this way, the performance can reach native 20% in my multiple tests. Cc: Zhang Chen <zhangckid@gmail.com> Cc: Li Zhijian <lizhijian@cn.fujitsu.com> Cc: Jason Wang <jasowang@redhat.com> Signed-off-by: Mao Zhongyi <maozy.fnst@cn.fujitsu.com> Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com> Signed-off-by: Zhang Chen <zhangckid@gmail.com> Reviewed-by: Zhang Chen <zhangckid@gmail.com> Tested-by: Zhang Chen <zhangckid@gmail.com> Signed-off-by: Jason Wang <jasowang@redhat.com>
2017-11-13colo: Consolidate the duplicate code chunk into a routineMao Zhongyi
Consolidate the code that extract the ip address(src,dst) and port number(src,dst) of the packet into a separate routine extract_ip_and_port() since the same chunk of code is called from two place. Cc: Zhang Chen <zhangckid@gmail.com> Cc: Li Zhijian <lizhijian@cn.fujitsu.com> Cc: Jason Wang <jasowang@redhat.com> Signed-off-by: Mao Zhongyi <maozy.fnst@cn.fujitsu.com> Signed-off-by: Jason Wang <jasowang@redhat.com>
2017-07-17net/colo.c: Make vnet_hdr_len as packet propertyZhang Chen
We can use this property flush and send packet with vnet_hdr_len. Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com> Signed-off-by: Jason Wang <jasowang@redhat.com>
2016-09-27filter-rewriter: rewrite tcp packet to keep secondary connectionZhang Chen
We will rewrite tcp packet secondary received and sent. When colo guest is a tcp server. Firstly, client start a tcp handshake. the packet's seq=client_seq, ack=0,flag=SYN. COLO primary guest get this pkt and mirror(filter-mirror) to secondary guest, secondary get it use filter-redirector. Then,primary guest response pkt (seq=primary_seq,ack=client_seq+1,flag=ACK|SYN). secondary guest response pkt (seq=secondary_seq,ack=client_seq+1,flag=ACK|SYN). In here,we use filter-rewriter save the secondary_seq to it's tcp connection. Finally handshake,client send pkt (seq=client_seq+1,ack=primary_seq+1,flag=ACK). Here,filter-rewriter can get primary_seq, and rewrite ack from primary_seq+1 to secondary_seq+1, recalculate checksum. So the secondary tcp connection kept good. When we send/recv packet. client send pkt(seq=client_seq+1+data_len,ack=primary_seq+1,flag=ACK|PSH). filter-rewriter rewrite ack and send to secondary guest. primary guest response pkt (seq=primary_seq+1,ack=client_seq+1+data_len,flag=ACK) secondary guest response pkt (seq=secondary_seq+1,ack=client_seq+1+data_len,flag=ACK) we rewrite secondary guest seq from secondary_seq+1 to primary_seq+1. So tcp connection kept good. In code We use offset( = secondary_seq - primary_seq ) to rewrite seq or ack. handle_primary_tcp_pkt: tcp_pkt->th_ack += offset; handle_secondary_tcp_pkt: tcp_pkt->th_seq -= offset; Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com> Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Jason Wang <jasowang@redhat.com>
2016-09-27filter-rewriter: track connection and parse packetZhang Chen
We use net/colo.h to track connection and parse packet Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com> Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Jason Wang <jasowang@redhat.com>
2016-09-27colo-compare: introduce packet comparison threadZhang Chen
If primary packet is same with secondary packet, we will send primary packet and drop secondary packet, otherwise notify COLO frame to do checkpoint. If primary packet comes but secondary packet does not, after REGULAR_PACKET_CHECK_MS milliseconds we set the primary packet as old_packet,then do a checkpoint. Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com> Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Jason Wang <jasowang@redhat.com>
2016-09-27colo-compare: track connection and enqueue packetZhang Chen
In this patch we use kernel jhash table to track connection, and then enqueue net packet like this: + CompareState ++ | | +---------------+ +---------------+ +---------------+ |conn list +--->conn +--------->conn | +---------------+ +---------------+ +---------------+ | | | | | | +---------------+ +---v----+ +---v----+ +---v----+ +---v----+ |primary | |secondary |primary | |secondary |packet | |packet + |packet | |packet + +--------+ +--------+ +--------+ +--------+ | | | | +---v----+ +---v----+ +---v----+ +---v----+ |primary | |secondary |primary | |secondary |packet | |packet + |packet | |packet + +--------+ +--------+ +--------+ +--------+ | | | | +---v----+ +---v----+ +---v----+ +---v----+ |primary | |secondary |primary | |secondary |packet | |packet + |packet | |packet + +--------+ +--------+ +--------+ +--------+ We use conn_list to record connection info. When we want to enqueue a packet, firstly get the connection from connection_track_table. then push the packet to g_queue(pri/sec) in it's own conn. Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com> Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Jason Wang <jasowang@redhat.com>
2016-09-27Jhash: add linux kernel jhashtable in qemuZhang Chen
Jhash will be used by colo-compare and filter-rewriter to save and lookup net connection info Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com> Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Jason Wang <jasowang@redhat.com>
2016-09-27net/colo.c: add colo.c to define and handle packetZhang Chen
The net/colo.c is used by colo-compare and filter-rewriter. this can share common data structure like net packet, and other functions. Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com> Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Jason Wang <jasowang@redhat.com>