diff options
Diffstat (limited to 'epan/packet.c')
| -rw-r--r-- | epan/packet.c | 125 |
1 files changed, 65 insertions, 60 deletions
diff --git a/epan/packet.c b/epan/packet.c index fb02e699a6..27a3434079 100644 --- a/epan/packet.c +++ b/epan/packet.c @@ -1,7 +1,7 @@ /* packet.c * Routines for packet disassembly * - * $Id: packet.c,v 1.79 2002/10/22 08:22:05 guy Exp $ + * $Id: packet.c,v 1.80 2002/10/28 23:04:15 guy Exp $ * * Ethereal - Network traffic analyzer * By Gerald Combs <gerald@ethereal.com> @@ -337,6 +337,57 @@ struct dissector_handle { }; /* + * Call a dissector through a handle. + * If the protocol for that handle isn't enabled, return 0 without + * calling the dissector. + * Otherwise, if the handle refers to a new-style dissector, call the + * dissector and return its return value, otherwise call it and return + * the length of the tvbuff pointed to by the argument. + */ +static int +call_dissector_work(dissector_handle_t handle, tvbuff_t *tvb, + packet_info *pinfo, proto_tree *tree) +{ + const char *saved_proto; + guint16 saved_can_desegment; + int ret; + + if (handle->proto_index != -1 && + !proto_is_protocol_enabled(handle->proto_index)) { + /* + * The protocol isn't enabled. + */ + return 0; + } + + saved_proto = pinfo->current_proto; + saved_can_desegment = pinfo->can_desegment; + + /* + * can_desegment is set to 2 by anyone which offers the + * desegmentation api/service. + * Then everytime a subdissector is called it is decremented + * by one. + * Thus only the subdissector immediately on top of whoever + * offers this service can use it. + */ + pinfo->can_desegment = saved_can_desegment-(saved_can_desegment>0); + if (handle->proto_index != -1) { + pinfo->current_proto = + proto_get_protocol_short_name(handle->proto_index); + } + if (handle->is_new) + ret = (*handle->dissector.new)(tvb, pinfo, tree); + else { + (*handle->dissector.old)(tvb, pinfo, tree); + ret = tvb_length(tvb); + } + pinfo->current_proto = saved_proto; + pinfo->can_desegment = saved_can_desegment; + return ret; +} + +/* * An entry in the hash table portion of a dissector table. */ struct dtbl_entry { @@ -518,9 +569,7 @@ dissector_try_port(dissector_table_t sub_dissectors, guint32 port, { dtbl_entry_t *dtbl_entry; struct dissector_handle *handle; - const char *saved_proto; guint32 saved_match_port; - guint16 saved_can_desegment; int ret; dtbl_entry = g_hash_table_lookup(sub_dissectors->hash_table, @@ -540,48 +589,14 @@ dissector_try_port(dissector_table_t sub_dissectors, guint32 port, } /* - * Yes - is its protocol enabled? + * Save the current value of "pinfo->match_port", + * set it to the port that matched, call the + * dissector, and restore "pinfo->match_port". */ - if (handle->proto_index != -1 && - !proto_is_protocol_enabled(handle->proto_index)) { - /* - * No - pretend this dissector didn't exist, - * so that other dissectors might have a chance - * to dissect this packet. - */ - return FALSE; - } - - /* - * Yes, it's enabled. - */ - saved_proto = pinfo->current_proto; saved_match_port = pinfo->match_port; - saved_can_desegment = pinfo->can_desegment; - - /* - * can_desegment is set to 2 by anyone which offers the - * desegmentation api/service. - * Then everytime a subdissector is called it is decremented - * by one. - * Thus only the subdissector immediately on top of whoever - * offers this serveice can use it. - */ - pinfo->can_desegment = saved_can_desegment-(saved_can_desegment>0); pinfo->match_port = port; - if (handle->proto_index != -1) { - pinfo->current_proto = - proto_get_protocol_short_name(handle->proto_index); - } - if (handle->is_new) - ret = (*handle->dissector.new)(tvb, pinfo, tree); - else { - (*handle->dissector.old)(tvb, pinfo, tree); - ret = 1; - } - pinfo->current_proto = saved_proto; + ret = call_dissector_work(handle, tvb, pinfo, tree); pinfo->match_port = saved_match_port; - pinfo->can_desegment = saved_can_desegment; /* * If a new-style dissector returned 0, it means that @@ -590,8 +605,11 @@ dissector_try_port(dissector_table_t sub_dissectors, guint32 port, * * Old-style dissectors can't reject the packet. * - * If the packet was rejected, we return FALSE, otherwise - * we return TRUE. + * 0 is also returned if the protocol wasn't enabled. + * + * If the packet was rejected, we return FALSE, so that + * other dissectors might have a chance to dissect this + * packet, otherwise we return TRUE. */ return ret != 0; } @@ -1074,31 +1092,18 @@ int call_dissector(dissector_handle_t handle, tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) { - const char *saved_proto; int ret; - if (handle->proto_index != -1 && - !proto_is_protocol_enabled(handle->proto_index)) { + ret = call_dissector_work(handle, tvb, pinfo, tree); + if (ret == 0) { /* - * No - just dissect this packet as data. + * The protocol was disabled, or the dissector rejected + * it. Just dissect this packet as data. */ g_assert(data_handle != NULL); g_assert(data_handle->proto_index != -1); call_dissector(data_handle, tvb, pinfo, tree); return tvb_length(tvb); } - - saved_proto = pinfo->current_proto; - if (handle->proto_index != -1) { - pinfo->current_proto = - proto_get_protocol_short_name(handle->proto_index); - } - if (handle->is_new) - ret = (*handle->dissector.new)(tvb, pinfo, tree); - else { - (*handle->dissector.old)(tvb, pinfo, tree); - ret = tvb_length(tvb); - } - pinfo->current_proto = saved_proto; return ret; } |