Fix memory leak in colo-compare.c and filter-rewriter.c
Report by Coverity and add some comments.
Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
Reviewed-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
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>
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>
Filter-rewriter is a part of COLO project.
It will rewrite some of secondary packet to make
secondary guest's tcp connection established successfully.
In this module we will rewrite tcp packet's ack to the secondary
from primary,and rewrite tcp packet's seq to the primary from
secondary.
usage:
colo secondary:
-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
-object filter-rewriter,id=rew0,netdev=hn0,queue=all
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>
