forked from osmocom/wireshark
![Michael Mann](/assets/img/avatar_default.png)
This patch introduces new APIs to allow dissectors to have a preference for a (TCP) port, but the underlying data is actually part of Decode As functionality. For now the APIs are intentionally separate from the regular APIs that register a dissector within a dissector table. It may be possible to eventually combine the two so that all dissectors that register with a dissector table have an opportunity to "automatically" have a preference to adjust the "table value" through the preferences dialog. The tcp.port dissector table was used as the guinea pig. This will eventually be expanded to other dissector tables as well (most notably UDP ports). Some dissectors that "shared" a TCP/UDP port preference were also converted. It also removed the need for some preference callback functions (mostly when the callback function was the proto_reg_handoff function) so there is cleanup around that. Dissectors that has a port preference whose default was 0 were switched to using the dissector_add_for_decode_as_with_preference API rather than dissector_add_uint_with_preference Also added comments for TCP ports used that aren't IANA registered. Change-Id: I99604f95d426ad345f4b494598d94178b886eb67 Reviewed-on: https://code.wireshark.org/review/17724 Reviewed-by: Michael Mann <mmann78@netscape.net>
277 lines
9.4 KiB
C
277 lines
9.4 KiB
C
/* packet-pmproxy.c
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*
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* Routines for dissecting Performance Co-Pilot Proxy
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*
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* Wireshark - Network traffic analyzer
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* By Gerald Combs <gerald@wireshark.org>
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* Copyright 1998 Gerald Combs
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#include "config.h"
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#include <epan/packet.h>
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#include <epan/conversation.h>
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#define PMPROXY_PORT 44322
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/* length of "pmproxy-server 1\n" and also "pmproxy-client 1\n" */
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#define PMPROXY_CLIENT_SERVER_VERSION_LENGTH 17
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#define PMPROXY_START_OF_PACKET 0
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#define PMPROXY_HOST_AND_PORT_DELIMETER_LENGTH 1
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static dissector_handle_t pmproxy_handle;
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static dissector_handle_t pcp_handle;
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static int proto_pmproxy = -1;
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static int hf_pmproxy_host = -1;
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static int hf_pmproxy_port = -1;
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static int hf_pmproxy_client_version = -1;
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static int hf_pmproxy_server_version = -1;
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static gint ett_pmproxy = -1;
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typedef struct pmproxy_conversation_info_t {
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guint32 last_proxy_frame;
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} pmproxy_conversation_info_t;
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void proto_register_pmproxy(void);
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void proto_reg_handoff_pmproxy(void);
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static int is_ascii(const guchar *data, gint size)
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{
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const unsigned char *str = data;
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const unsigned char *end = str + size;
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for (; str != end; str++) {
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if (*str & 0x80)
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return FALSE;
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}
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return TRUE;
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}
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static int looks_like_proxy_exchange(tvbuff_t *tvb) {
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gint packet_length;
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const guchar *packet_data;
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packet_length = tvb_ensure_captured_length_remaining(tvb, PMPROXY_START_OF_PACKET);
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packet_data = tvb_get_ptr(tvb, PMPROXY_START_OF_PACKET, packet_length);
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/* A proxy exchange packet only contains ascii characters (eg "localhost 44321") and terminated with \n */
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return is_ascii(packet_data, packet_length) && packet_data[packet_length-1] == '\n';
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}
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static int dissect_proxy_to_host(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) {
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int offset = 0;
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gint next_offset;
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gint proxy_to_length;
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gchar *pmproxy_host_and_port_string;
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gchar **host_and_port;
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gchar *host;
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gchar *port;
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col_set_str(pinfo->cinfo, COL_INFO, "Proxy");
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proxy_to_length = tvb_find_line_end(tvb, offset, tvb_ensure_captured_length_remaining(tvb, offset), &next_offset, FALSE);
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if(proxy_to_length != -1) {
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pmproxy_host_and_port_string = (gchar *) tvb_get_string_enc(wmem_packet_scope(), tvb, offset, proxy_to_length, ENC_ASCII);
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host_and_port = wmem_strsplit(wmem_packet_scope(), pmproxy_host_and_port_string, " ", -1);
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if(host_and_port != NULL) {
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host = host_and_port[0];
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if (host) {
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proto_tree_add_string(tree, hf_pmproxy_host, tvb, offset, (guint32)strlen(host), host);
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offset += (int)strlen(host) + PMPROXY_HOST_AND_PORT_DELIMETER_LENGTH;
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port = host_and_port[1];
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if (port) {
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proto_tree_add_string(tree, hf_pmproxy_port, tvb, offset, (guint32)strlen(port), port);
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}
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} else {
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port = NULL;
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}
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col_append_fstr(pinfo->cinfo, COL_INFO, " Host=%s, Port=%s", host ? host : "", port ? port : "");
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}
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}
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return proxy_to_length;
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}
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static int is_banner_exchange_for(const gchar *type, tvbuff_t *tvb) {
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gchar *pmproxy_exchange_string;
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/* Exchange packets have to be this length */
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if(tvb_ensure_captured_length_remaining(tvb, PMPROXY_START_OF_PACKET) != PMPROXY_CLIENT_SERVER_VERSION_LENGTH) {
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return 0;
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}
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pmproxy_exchange_string = (gchar *) tvb_get_string_enc(wmem_packet_scope(), tvb, PMPROXY_START_OF_PACKET,
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PMPROXY_CLIENT_SERVER_VERSION_LENGTH, ENC_ASCII);
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return g_strcmp0(pmproxy_exchange_string, wmem_strdup_printf(wmem_packet_scope(), "pmproxy-%s 1\n", type)) == 0;
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}
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static int is_server_exchange(tvbuff_t *tvb) {
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return is_banner_exchange_for("server", tvb);
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}
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static int is_client_exchange(tvbuff_t *tvb) {
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return is_banner_exchange_for("client", tvb);
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}
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static int dissect_server_exchange(tvbuff_t *tvb, packet_info *pinfo, proto_tree *pmproxy_tree) {
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int offset = PMPROXY_START_OF_PACKET;
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col_set_str(pinfo->cinfo, COL_INFO, "Server exchange");
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proto_tree_add_item(pmproxy_tree, hf_pmproxy_server_version, tvb, offset, PMPROXY_CLIENT_SERVER_VERSION_LENGTH, ENC_ASCII|ENC_NA);
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offset += PMPROXY_CLIENT_SERVER_VERSION_LENGTH;
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return offset;
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}
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static int dissect_client_exchange(tvbuff_t *tvb, packet_info *pinfo, proto_tree *pmproxy_tree) {
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int offset = PMPROXY_START_OF_PACKET;
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col_set_str(pinfo->cinfo, COL_INFO, "Client exchange");
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proto_tree_add_item(pmproxy_tree, hf_pmproxy_client_version, tvb, offset, PMPROXY_CLIENT_SERVER_VERSION_LENGTH, ENC_ASCII|ENC_NA);
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offset += PMPROXY_CLIENT_SERVER_VERSION_LENGTH;
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return offset;
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}
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static void mark_pmproxy_exchange_complete(packet_info *pinfo) {
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conversation_t *conversation;
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pmproxy_conversation_info_t *pmproxy_conversation;
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conversation = find_or_create_conversation(pinfo);
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pmproxy_conversation = (pmproxy_conversation_info_t *)conversation_get_proto_data(conversation, proto_pmproxy);
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if(pmproxy_conversation == NULL) {
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pmproxy_conversation = wmem_new(wmem_file_scope(), pmproxy_conversation_info_t);
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}
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pmproxy_conversation->last_proxy_frame = pinfo->num;
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conversation_add_proto_data(conversation, proto_pmproxy, pmproxy_conversation);
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}
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static int is_pmproxy_exchange_complete(packet_info *pinfo) {
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conversation_t *conversation;
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pmproxy_conversation_info_t *pmproxy_conversation;
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conversation = find_or_create_conversation(pinfo);
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pmproxy_conversation = (pmproxy_conversation_info_t *)conversation_get_proto_data(conversation, proto_pmproxy);
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if(pmproxy_conversation == NULL) {
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return FALSE;
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}
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return pinfo->num >= pmproxy_conversation->last_proxy_frame;
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}
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static int dissect_through_pcp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) {
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pinfo->can_desegment = pinfo->saved_can_desegment;
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return call_dissector(pcp_handle, tvb, pinfo, tree);
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}
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static int dissect_pmproxy_exchange(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) {
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proto_item *root_pmproxy_item;
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proto_tree *pmproxy_tree;
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root_pmproxy_item = proto_tree_add_item(tree, proto_pmproxy, tvb, 0, -1, ENC_NA);
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pmproxy_tree = proto_item_add_subtree(root_pmproxy_item, ett_pmproxy);
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if (is_server_exchange(tvb)) {
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return dissect_server_exchange(tvb, pinfo, pmproxy_tree);
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} else if (is_client_exchange(tvb)) {
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return dissect_client_exchange(tvb, pinfo, pmproxy_tree);
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} else if (looks_like_proxy_exchange(tvb)) {
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return dissect_proxy_to_host(tvb, pinfo, pmproxy_tree);
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} else {
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/* If its none of these, it is going to be vanilla PCP traffic */
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mark_pmproxy_exchange_complete(pinfo);
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}
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return tvb_reported_length_remaining(tvb, 0);
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}
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static int dissect_pmproxy(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_) {
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col_set_str(pinfo->cinfo, COL_PROTOCOL, "PMPROXY");
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col_clear(pinfo->cinfo, COL_INFO);
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if(is_pmproxy_exchange_complete(pinfo)) {
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return dissect_through_pcp(tvb, pinfo, tree);
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}
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else {
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return dissect_pmproxy_exchange(tvb, pinfo, tree);
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}
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}
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void proto_register_pmproxy(void) {
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static hf_register_info hf[] = {
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{ &hf_pmproxy_host,
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{ "Host", "pmproxy.host",
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FT_STRING, BASE_NONE,
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NULL, 0x0,
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NULL, HFILL
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}
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},
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{ &hf_pmproxy_port,
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{ "Port", "pmproxy.port",
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FT_STRING, BASE_NONE,
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NULL, 0x0,
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NULL, HFILL
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}
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},
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{ &hf_pmproxy_client_version,
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{ "Client Version", "pmproxy.client_version",
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FT_STRING, BASE_NONE,
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NULL, 0x0,
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NULL, HFILL
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}
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},
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{ &hf_pmproxy_server_version,
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{ "Server Version", "pmproxy.server_version",
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FT_STRING, BASE_NONE,
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NULL, 0x0,
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NULL, HFILL
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}
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},
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};
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static gint *ett[] = {
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&ett_pmproxy,
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};
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proto_pmproxy = proto_register_protocol("Performance Co-Pilot Proxy", "PMPROXY", "pmproxy");
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proto_register_field_array(proto_pmproxy, hf, array_length(hf));
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proto_register_subtree_array(ett, array_length(ett));
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}
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void proto_reg_handoff_pmproxy(void) {
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pmproxy_handle = create_dissector_handle(dissect_pmproxy, proto_pmproxy);
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pcp_handle = find_dissector_add_dependency("pcp", proto_pmproxy);
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dissector_add_uint_with_preference("tcp.port", PMPROXY_PORT, pmproxy_handle);
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}
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/*
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* Editor modelines - https://www.wireshark.org/tools/modelines.html
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*
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* Local variables:
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* c-basic-offset: 4
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* tab-width: 8
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* indent-tabs-mode: nil
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* End:
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*
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* vi: set shiftwidth=4 tabstop=8 expandtab:
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* :indentSize=4:tabSize=8:noTabs=true:
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*/
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