net/colo-compare.c: Fix ACK track reverse issue

The TCP protocol ACK maybe bigger than uint32_t MAX.
At this time, the ACK will reverse to 0. This patch
fix the max_ack and min_ack track issue.

Signed-off-by: Zhang Chen <chen.zhang@intel.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>

net/colo-compare.c

@@ -209,7 +209,8 @@ static void fill_pkt_tcp_info(void *data, uint32_t *max_ack)
 
     pkt->tcp_seq = ntohl(tcphd->th_seq);
     pkt->tcp_ack = ntohl(tcphd->th_ack);
-    *max_ack = *max_ack > pkt->tcp_ack ? *max_ack : pkt->tcp_ack;
+    /* Need to consider ACK will bigger than uint32_t MAX */
+    *max_ack = pkt->tcp_ack - *max_ack > 0 ? pkt->tcp_ack : *max_ack;
     pkt->header_size = pkt->transport_header - (uint8_t *)pkt->data
                        + (tcphd->th_off << 2);
     pkt->payload_size = pkt->size - pkt->header_size;
@@ -413,7 +414,8 @@ static void colo_compare_tcp(CompareState *s, Connection *conn)
      * can ensure that the packet's payload is acknowledged by
      * primary and secondary.
     */
-    uint32_t min_ack = conn->pack > conn->sack ? conn->sack : conn->pack;
+    uint32_t min_ack = conn->pack - conn->sack > 0 ?
+                       conn->sack : conn->pack;
 
 pri:
     if (g_queue_is_empty(&conn->primary_list)) {