diff options
| -rw-r--r-- | packet-sctp.c | 61 | ||||
| -rw-r--r-- | packet-tcp.c | 33 | ||||
| -rw-r--r-- | packet-udp.c | 34 |
3 files changed, 103 insertions, 25 deletions
diff --git a/packet-sctp.c b/packet-sctp.c index 47536178b0..1587dd937e 100644 --- a/packet-sctp.c +++ b/packet-sctp.c @@ -10,7 +10,7 @@ * - support for reassembly * - code cleanup * - * $Id: packet-sctp.c,v 1.37 2002/05/30 08:34:18 guy Exp $ + * $Id: packet-sctp.c,v 1.38 2002/06/08 21:54:52 guy Exp $ * * Ethereal - Network traffic analyzer * By Gerald Combs <gerald@ethereal.com> @@ -1317,24 +1317,51 @@ static gboolean dissect_payload(tvbuff_t *payload_tvb, packet_info *pinfo, proto_tree *tree, proto_tree *chunk_tree, guint32 ppi, guint16 payload_length, guint16 padding_length) { - /* do lookup with the subdissector table */ - if (dissector_try_port (sctp_ppi_dissector_table, ppi, payload_tvb, pinfo, tree) || - dissector_try_port(sctp_port_dissector_table, pinfo->srcport, payload_tvb, pinfo, tree) || - dissector_try_port(sctp_port_dissector_table, pinfo->destport, payload_tvb, pinfo, tree)){ + guint32 low_port, high_port; + + /* Do lookups with the subdissector table. + + When trying port numbers, we try the port number with the lower value + first, followed by the port number with the higher value. This means + that, for packets where a dissector is registered for *both* port + numbers, and where there's no match on the PPI: + + 1) we pick the same dissector for traffic going in both directions; + + 2) we prefer the port number that's more likely to be the right + one (as that prefers well-known ports to reserved ports); + + although there is, of course, no guarantee that any such strategy + will always pick the right port number. + + XXX - we ignore port numbers of 0, as some dissectors use a port + number of 0 to disable the port. */ + if (dissector_try_port(sctp_ppi_dissector_table, ppi, payload_tvb, pinfo, tree)) return TRUE; + if (pinfo->srcport > pinfo->destport) { + low_port = pinfo->destport; + high_port = pinfo->srcport; + } else { + low_port = pinfo->srcport; + high_port = pinfo->destport; } - else { - if (check_col(pinfo->cinfo, COL_INFO)) - col_append_str(pinfo->cinfo, COL_INFO, "DATA "); - proto_tree_add_text(chunk_tree, payload_tvb, 0, payload_length, - "Payload (%u byte%s)", - payload_length, plurality(payload_length, "", "s")); - if (padding_length > 0) - proto_tree_add_text(chunk_tree, payload_tvb, payload_length, padding_length, - "Padding: %u byte%s", - padding_length, plurality(padding_length, "", "s")); - return FALSE; - } + if (low_port != 0 && + dissector_try_port(sctp_port_dissector_table, low_port, payload_tvb, pinfo, tree)) + return TRUE; + if (high_port != 0 && + dissector_try_port(sctp_port_dissector_table, high_port, payload_tvb, pinfo, tree)) + return TRUE; + + if (check_col(pinfo->cinfo, COL_INFO)) + col_append_str(pinfo->cinfo, COL_INFO, "DATA "); + proto_tree_add_text(chunk_tree, payload_tvb, 0, payload_length, + "Payload (%u byte%s)", + payload_length, plurality(payload_length, "", "s")); + if (padding_length > 0) + proto_tree_add_text(chunk_tree, payload_tvb, payload_length, padding_length, + "Padding: %u byte%s", + padding_length, plurality(padding_length, "", "s")); + return FALSE; } static gboolean diff --git a/packet-tcp.c b/packet-tcp.c index c8a1db09ac..515075d9d1 100644 --- a/packet-tcp.c +++ b/packet-tcp.c @@ -1,7 +1,7 @@ /* packet-tcp.c * Routines for TCP packet disassembly * - * $Id: packet-tcp.c,v 1.143 2002/06/04 07:03:46 guy Exp $ + * $Id: packet-tcp.c,v 1.144 2002/06/08 21:54:52 guy Exp $ * * Ethereal - Network traffic analyzer * By Gerald Combs <gerald@ethereal.com> @@ -1023,6 +1023,7 @@ decode_tcp_ports(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree, int src_port, int dst_port) { tvbuff_t *next_tvb; + int low_port, high_port; next_tvb = tvb_new_subset(tvb, offset, -1, -1); @@ -1033,9 +1034,33 @@ decode_tcp_ports(tvbuff_t *tvb, int offset, packet_info *pinfo, src_port, dst_port, next_tvb, pinfo, tree)) return; - /* do lookup with the subdissector table */ - if (dissector_try_port(subdissector_table, src_port, next_tvb, pinfo, tree) || - dissector_try_port(subdissector_table, dst_port, next_tvb, pinfo, tree)) + /* Do lookups with the subdissector table. + We try the port number with the lower value first, followed by the + port number with the higher value. This means that, for packets + where a dissector is registered for *both* port numbers: + + 1) we pick the same dissector for traffic going in both directions; + + 2) we prefer the port number that's more likely to be the right + one (as that prefers well-known ports to reserved ports); + + although there is, of course, no guarantee that any such strategy + will always pick the right port number. + + XXX - we ignore port numbers of 0, as some dissectors use a port + number of 0 to disable the port. */ + if (src_port > dst_port) { + low_port = dst_port; + high_port = src_port; + } else { + low_port = src_port; + high_port = dst_port; + } + if (low_port != 0 && + dissector_try_port(subdissector_table, low_port, next_tvb, pinfo, tree)) + return; + if (high_port != 0 && + dissector_try_port(subdissector_table, high_port, next_tvb, pinfo, tree)) return; /* do lookup with the heuristic subdissector table */ diff --git a/packet-udp.c b/packet-udp.c index aab65d01ad..32d8ce4ed4 100644 --- a/packet-udp.c +++ b/packet-udp.c @@ -1,7 +1,7 @@ /* packet-udp.c * Routines for UDP packet disassembly * - * $Id: packet-udp.c,v 1.102 2002/01/22 15:05:43 nneul Exp $ + * $Id: packet-udp.c,v 1.103 2002/06/08 21:54:51 guy Exp $ * * Ethereal - Network traffic analyzer * By Gerald Combs <gerald@ethereal.com> @@ -88,6 +88,7 @@ decode_udp_ports(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree, int uh_sport, int uh_dport) { tvbuff_t *next_tvb; + int low_port, high_port; next_tvb = tvb_new_subset(tvb, offset, -1, -1); @@ -98,9 +99,34 @@ decode_udp_ports(tvbuff_t *tvb, int offset, packet_info *pinfo, uh_sport, uh_dport, next_tvb, pinfo, tree)) return; - /* do lookup with the subdissector table */ - if (dissector_try_port(udp_dissector_table, uh_sport, next_tvb, pinfo, tree) || - dissector_try_port(udp_dissector_table, uh_dport, next_tvb, pinfo, tree)) + /* Do lookups with the subdissector table. + We try the port number with the lower value first, followed by the + port number with the higher value. This means that, for packets + where a dissector is registered for *both* port numbers: + + 1) we pick the same dissector for traffic going in both directions; + + 2) we prefer the port number that's more likely to be the right + one (as that prefers well-known ports to reserved ports); + + although there is, of course, no guarantee that any such strategy + will always pick the right port number. + + XXX - we ignore port numbers of 0, as some dissectors use a port + number of 0 to disable the port, and as RFC 768 says that the source + port in UDP datagrams is optional and is 0 if not used. */ + if (uh_sport > uh_dport) { + low_port = uh_dport; + high_port = uh_sport; + } else { + low_port = uh_sport; + high_port = uh_dport; + } + if (low_port != 0 && + dissector_try_port(udp_dissector_table, low_port, next_tvb, pinfo, tree)) + return; + if (high_port != 0 && + dissector_try_port(udp_dissector_table, high_port, next_tvb, pinfo, tree)) return; /* do lookup with the heuristic subdissector table */ |