diff options
Diffstat (limited to 'packet-nbns.c')
| -rw-r--r-- | packet-nbns.c | 66 |
1 files changed, 50 insertions, 16 deletions
diff --git a/packet-nbns.c b/packet-nbns.c index 0c3447f53e..eae3224087 100644 --- a/packet-nbns.c +++ b/packet-nbns.c @@ -3,7 +3,7 @@ * to when it had only NBNS) * Guy Harris <guy@alum.mit.edu> * - * $Id: packet-nbns.c,v 1.73 2002/02/18 23:51:55 guy Exp $ + * $Id: packet-nbns.c,v 1.74 2002/02/28 23:09:03 guy Exp $ * * Ethereal - Network traffic analyzer * By Gerald Combs <gerald@ethereal.com> @@ -1359,6 +1359,7 @@ dissect_nbss_packet(tvbuff_t *tvb, int offset, packet_info *pinfo, guint8 msg_type; guint8 flags; volatile int length; + int length_remaining; int len; char name[(NETBIOS_NAME_LEN - 1)*4 + MAXDNAME]; int name_type; @@ -1366,8 +1367,28 @@ dissect_nbss_packet(tvbuff_t *tvb, int offset, packet_info *pinfo, tvbuff_t *next_tvb; const char *saved_proto; - msg_type = tvb_get_guint8(tvb, offset); + /* Desegmentation */ + length_remaining = tvb_length_remaining(tvb, offset); + + /* + * Can we do reassembly? + */ + if (nbss_desegment && pinfo->can_desegment) { + /* + * Yes - is the NBSS header split across segment boundaries? + */ + if (length_remaining < 4) { + /* + * Yes. Tell our caller how many more bytes + * we need. + */ + return -(4 - length_remaining); + } + } + /* + * Get the length of the NBSS message. + */ if (is_cifs) { flags = 0; length = tvb_get_ntoh24(tvb, offset + 1); @@ -1378,25 +1399,24 @@ dissect_nbss_packet(tvbuff_t *tvb, int offset, packet_info *pinfo, length += 65536; } - /*Desegmentation */ - if (nbss_desegment) { - if (pinfo->can_desegment - && length > tvb_length_remaining(tvb, offset+4)) { + /* + * Can we do reassembly? + */ + if (nbss_desegment && pinfo->can_desegment) { + /* + * Yes - is the NBSS message split across segment boundaries? + */ + if (length_remaining < length + 4) { /* - * This frame doesn't have all of the data for - * this message, but we can do reassembly on it. - * - * Tell the TCP dissector where the data for this - * message starts in the data it handed us, and - * how many more bytes we need, and return. + * Yes. Tell our caller how many more bytes + * we need. */ - pinfo->desegment_offset = offset; - pinfo->desegment_len = - length - tvb_length_remaining(tvb, offset+4); - return max_data; + return -((length + 4) - length_remaining); } } + msg_type = tvb_get_guint8(tvb, offset); + if (tree) { ti = proto_tree_add_item(tree, proto_nbss, tvb, offset, length + 4, FALSE); nbss_tree = proto_item_add_subtree(ti, ett_nbss); @@ -1687,6 +1707,20 @@ dissect_nbss(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) while (max_data > 0) { len = dissect_nbss_packet(tvb, offset, pinfo, tree, max_data, is_cifs); + if (len < 0) { + /* + * We need more data to dissect this, and + * desegmentation is enabled. "-len" is the + * number of additional bytes of data we need. + * + * Tell the TCP dissector where the data for this + * message starts in the data it handed us, and + * how many more bytes we need, and return. + */ + pinfo->desegment_offset = offset; + pinfo->desegment_len = -len; + return; + } offset += len; max_data -= len; } |