On 02/22/2017 11:46 AM, zhanghailiang wrote:
While the offset of packets's sequence for primary side and
secondary 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) {"
+ /* 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.
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