diff options
| -rw-r--r-- | src/lib/ndpi_main.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/src/lib/ndpi_main.c b/src/lib/ndpi_main.c index eb883d677..1e3170862 100644 --- a/src/lib/ndpi_main.c +++ b/src/lib/ndpi_main.c @@ -3923,7 +3923,12 @@ void ndpi_connection_tracking(struct ndpi_detection_module_struct *ndpi_str, flow->next_tcp_seq_nr[flow->packet.packet_direction] = ntohl(tcph->seq) + (tcph->syn ? 1 : packet->payload_packet_len); - flow->next_tcp_seq_nr[1 - flow->packet.packet_direction] = ntohl(tcph->ack_seq); + /* + Check to avoid discrepancies in case we analyze a flow that does not start with SYN... + but that is already started when nDPI being to process it. See also (***) below + */ + if(flow->num_processed_pkts > 1) + flow->next_tcp_seq_nr[1 - flow->packet.packet_direction] = ntohl(tcph->ack_seq); } } else if(packet->payload_packet_len > 0) { /* check tcp sequence counters */ @@ -3940,7 +3945,9 @@ void ndpi_connection_tracking(struct ndpi_detection_module_struct *ndpi_str, packet->num_retried_bytes = (u_int16_t)(flow->next_tcp_seq_nr[packet->packet_direction] - ntohl(tcph->seq)); packet->actual_payload_len = packet->payload_packet_len - packet->num_retried_bytes; - flow->next_tcp_seq_nr[packet->packet_direction] = ntohl(tcph->seq) + packet->payload_packet_len; + + if(flow->num_processed_pkts > 1) /* See also (***) above */ + flow->next_tcp_seq_nr[packet->packet_direction] = ntohl(tcph->seq) + packet->payload_packet_len; } } |