diff options
| -rw-r--r-- | epan/dissectors/packet-tcp.c | 29 |
1 files changed, 27 insertions, 2 deletions
diff --git a/epan/dissectors/packet-tcp.c b/epan/dissectors/packet-tcp.c index 66849afd0c..c4a9a6eb15 100644 --- a/epan/dissectors/packet-tcp.c +++ b/epan/dissectors/packet-tcp.c @@ -3217,12 +3217,16 @@ again: } } - if (reassemble_ooo && tcpd && !PINFO_FD_VISITED(pinfo)) { + if (reassemble_ooo && tcpd && !(tcpd->fwd->flags & TCP_FLOW_REASSEMBLE_UNTIL_FIN) && !PINFO_FD_VISITED(pinfo)) { /* If there is a gap between this segment and any previous ones (that * is, seqno is larger than the maximum expected seqno), then it is * possibly an out-of-order segment. The very first segment is expected * to be in-order though (otherwise captures starting in midst of a * connection would never be reassembled). + * + * Do not bother checking for OoO segments for streams that are + * reassembled at FIN, the order of segments before FIN does not matter + * as reordering and reassembly occurs at FIN. */ if (tcpd->fwd->maxnextseq) { /* Segments may be missing due to packet loss (assume later @@ -3290,7 +3294,7 @@ again: last_fragment_len = len; - if (reassemble_ooo) { + if (reassemble_ooo && tcpd && !(tcpd->fwd->flags & TCP_FLOW_REASSEMBLE_UNTIL_FIN)) { /* * If the previous segment requested more data (setting * FD_PARTIAL_REASSEMBLY as the next segment length is unknown), but @@ -3298,6 +3302,12 @@ again: * then "fragment_add" would truncate the reassembled PDU to the end * of this OoO segment. To prevent that, explicitly specify the MSP * length before calling "fragment_add". + * + * When a subdissector requests reassembly at the end of the + * connection (DESEGMENT_UNTIL_FIN), then it is not + * possible for an earlier segment to complete reassembly + * (more_frags for fragment_add is always TRUE). Thus we do not + * have to worry about increasing the fragment length here. */ fragment_reset_tot_len(&tcp_reassembly_table, pinfo, msp->first_frame, NULL, @@ -3599,6 +3609,21 @@ again: msp = pdu_store_sequencenumber_of_next_pdu(pinfo, deseg_seq, nxtseq+1, tcpd->fwd->multisegment_pdus); msp->flags |= MSP_FLAGS_REASSEMBLE_ENTIRE_SEGMENT; + } else if (pinfo->desegment_len == DESEGMENT_UNTIL_FIN) { + /* + * The subdissector asked to reassemble at the end of the + * connection. That will be done in dissect_tcp, but here we + * have to ask reassembly to collect all future segments. + * Note that TCP_FLOW_REASSEMBLE_UNTIL_FIN was set before, this + * ensures that OoO detection is skipped. + * The exact nxtpdu offset does not matter, but it should be + * smaller than half of the maximum 32-bit unsigned integer to + * allow detection of sequence number wraparound, and larger + * than the largest possible stream size. Hopefully 1GiB + * (0x40000000 bytes) should be enough. + */ + msp = pdu_store_sequencenumber_of_next_pdu(pinfo, deseg_seq, + nxtseq+0x40000000, tcpd->fwd->multisegment_pdus); } else { msp = pdu_store_sequencenumber_of_next_pdu(pinfo, deseg_seq, nxtseq+pinfo->desegment_len, tcpd->fwd->multisegment_pdus); |