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/* packet-pmproxy.c
*
* Routines for dissecting Performance Co-Pilot Proxy
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "config.h"
#include <epan/packet.h>
#include <epan/conversation.h>
#include <epan/strutil.h>
#define PMPROXY_PORT 44322
/* length of "pmproxy-server 1\n" and also "pmproxy-client 1\n" */
#define PMPROXY_CLIENT_SERVER_VERSION_LENGTH 17
#define PMPROXY_START_OF_PACKET 0
#define PMPROXY_HOST_AND_PORT_DELIMETER_LENGTH 1
static dissector_handle_t pmproxy_handle;
static dissector_handle_t pcp_handle;
static int proto_pmproxy = -1;
static int hf_pmproxy_host = -1;
static int hf_pmproxy_port = -1;
static int hf_pmproxy_client_version = -1;
static int hf_pmproxy_server_version = -1;
static gint ett_pmproxy = -1;
typedef struct pmproxy_conversation_info_t {
guint32 last_proxy_frame;
} pmproxy_conversation_info_t;
void proto_register_pmproxy(void);
void proto_reg_handoff_pmproxy(void);
static int is_ascii(const guchar *data, gint size)
{
const unsigned char *str = data;
const unsigned char *end = str + size;
for (; str != end; str++) {
if (*str & 0x80)
return FALSE;
}
return TRUE;
}
static int looks_like_proxy_exchange(tvbuff_t *tvb) {
gint packet_length;
const guchar *packet_data;
packet_length = tvb_ensure_captured_length_remaining(tvb, PMPROXY_START_OF_PACKET);
packet_data = tvb_get_ptr(tvb, PMPROXY_START_OF_PACKET, packet_length);
/* A proxy exchange packet only contains ascii characters (eg "localhost 44321") and terminated with \n */
return is_ascii(packet_data, packet_length) && packet_data[packet_length-1] == '\n';
}
static int dissect_proxy_to_host(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) {
int offset = 0;
gint next_offset;
gint proxy_to_length;
gchar *pmproxy_host_and_port_string;
gchar **host_and_port;
gchar *host;
gchar *port;
col_set_str(pinfo->cinfo, COL_INFO, "Proxy");
proxy_to_length = tvb_find_line_end(tvb, offset, tvb_ensure_captured_length_remaining(tvb, offset), &next_offset, FALSE);
if(proxy_to_length != -1) {
pmproxy_host_and_port_string = (gchar *) tvb_get_string_enc(wmem_packet_scope(), tvb, offset, proxy_to_length, ENC_ASCII);
host_and_port = wmem_strsplit(wmem_packet_scope(), pmproxy_host_and_port_string, " ", -1);
if(host_and_port != NULL) {
host = host_and_port[0];
if (host) {
proto_tree_add_string(tree, hf_pmproxy_host, tvb, offset, (guint32)strlen(host), host);
offset += (int)strlen(host) + PMPROXY_HOST_AND_PORT_DELIMETER_LENGTH;
port = host_and_port[1];
if (port) {
proto_tree_add_string(tree, hf_pmproxy_port, tvb, offset, (guint32)strlen(port), port);
}
} else {
port = NULL;
}
col_append_fstr(pinfo->cinfo, COL_INFO, " Host=%s, Port=%s", host ? host : "", port ? port : "");
}
}
return proxy_to_length;
}
static int is_banner_exchange_for(const gchar *type, tvbuff_t *tvb) {
gchar *pmproxy_exchange_string;
/* Exchange packets have to be this length */
if(tvb_ensure_captured_length_remaining(tvb, PMPROXY_START_OF_PACKET) != PMPROXY_CLIENT_SERVER_VERSION_LENGTH) {
return 0;
}
pmproxy_exchange_string = (gchar *) tvb_get_string_enc(wmem_packet_scope(), tvb, PMPROXY_START_OF_PACKET,
PMPROXY_CLIENT_SERVER_VERSION_LENGTH, ENC_ASCII);
return g_strcmp0(pmproxy_exchange_string, wmem_strdup_printf(wmem_packet_scope(), "pmproxy-%s 1\n", type)) == 0;
}
static int is_server_exchange(tvbuff_t *tvb) {
return is_banner_exchange_for("server", tvb);
}
static int is_client_exchange(tvbuff_t *tvb) {
return is_banner_exchange_for("client", tvb);
}
static int dissect_server_exchange(tvbuff_t *tvb, packet_info *pinfo, proto_tree *pmproxy_tree) {
int offset = PMPROXY_START_OF_PACKET;
col_set_str(pinfo->cinfo, COL_INFO, "Server exchange");
proto_tree_add_item(pmproxy_tree, hf_pmproxy_server_version, tvb, offset, PMPROXY_CLIENT_SERVER_VERSION_LENGTH, ENC_ASCII);
offset += PMPROXY_CLIENT_SERVER_VERSION_LENGTH;
return offset;
}
static int dissect_client_exchange(tvbuff_t *tvb, packet_info *pinfo, proto_tree *pmproxy_tree) {
int offset = PMPROXY_START_OF_PACKET;
col_set_str(pinfo->cinfo, COL_INFO, "Client exchange");
proto_tree_add_item(pmproxy_tree, hf_pmproxy_client_version, tvb, offset, PMPROXY_CLIENT_SERVER_VERSION_LENGTH, ENC_ASCII);
offset += PMPROXY_CLIENT_SERVER_VERSION_LENGTH;
return offset;
}
static void mark_pmproxy_exchange_complete(packet_info *pinfo) {
conversation_t *conversation;
pmproxy_conversation_info_t *pmproxy_conversation;
conversation = find_or_create_conversation(pinfo);
pmproxy_conversation = (pmproxy_conversation_info_t *)conversation_get_proto_data(conversation, proto_pmproxy);
if(pmproxy_conversation == NULL) {
pmproxy_conversation = wmem_new(wmem_file_scope(), pmproxy_conversation_info_t);
}
pmproxy_conversation->last_proxy_frame = pinfo->num;
conversation_add_proto_data(conversation, proto_pmproxy, pmproxy_conversation);
}
static int is_pmproxy_exchange_complete(packet_info *pinfo) {
conversation_t *conversation;
pmproxy_conversation_info_t *pmproxy_conversation;
conversation = find_or_create_conversation(pinfo);
pmproxy_conversation = (pmproxy_conversation_info_t *)conversation_get_proto_data(conversation, proto_pmproxy);
if(pmproxy_conversation == NULL) {
return FALSE;
}
return pinfo->num >= pmproxy_conversation->last_proxy_frame;
}
static int dissect_through_pcp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) {
pinfo->can_desegment = pinfo->saved_can_desegment;
return call_dissector(pcp_handle, tvb, pinfo, tree);
}
static int dissect_pmproxy_exchange(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) {
proto_item *root_pmproxy_item;
proto_tree *pmproxy_tree;
root_pmproxy_item = proto_tree_add_item(tree, proto_pmproxy, tvb, 0, -1, ENC_NA);
pmproxy_tree = proto_item_add_subtree(root_pmproxy_item, ett_pmproxy);
if (is_server_exchange(tvb)) {
return dissect_server_exchange(tvb, pinfo, pmproxy_tree);
} else if (is_client_exchange(tvb)) {
return dissect_client_exchange(tvb, pinfo, pmproxy_tree);
} else if (looks_like_proxy_exchange(tvb)) {
return dissect_proxy_to_host(tvb, pinfo, pmproxy_tree);
} else {
/* If its none of these, it is going to be vanilla PCP traffic */
mark_pmproxy_exchange_complete(pinfo);
}
return tvb_reported_length_remaining(tvb, 0);
}
static int dissect_pmproxy(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_) {
col_set_str(pinfo->cinfo, COL_PROTOCOL, "PMPROXY");
col_clear(pinfo->cinfo, COL_INFO);
if(is_pmproxy_exchange_complete(pinfo)) {
return dissect_through_pcp(tvb, pinfo, tree);
}
else {
return dissect_pmproxy_exchange(tvb, pinfo, tree);
}
}
void proto_register_pmproxy(void) {
static hf_register_info hf[] = {
{ &hf_pmproxy_host,
{ "Host", "pmproxy.host",
FT_STRING, BASE_NONE,
NULL, 0x0,
NULL, HFILL
}
},
{ &hf_pmproxy_port,
{ "Port", "pmproxy.port",
FT_STRING, BASE_NONE,
NULL, 0x0,
NULL, HFILL
}
},
{ &hf_pmproxy_client_version,
{ "Client Version", "pmproxy.client_version",
FT_STRING, BASE_NONE,
NULL, 0x0,
NULL, HFILL
}
},
{ &hf_pmproxy_server_version,
{ "Server Version", "pmproxy.server_version",
FT_STRING, BASE_NONE,
NULL, 0x0,
NULL, HFILL
}
},
};
static gint *ett[] = {
&ett_pmproxy,
};
proto_pmproxy = proto_register_protocol("Performance Co-Pilot Proxy", "PMPROXY", "pmproxy");
proto_register_field_array(proto_pmproxy, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
}
void proto_reg_handoff_pmproxy(void) {
pmproxy_handle = create_dissector_handle(dissect_pmproxy, proto_pmproxy);
pcp_handle = find_dissector_add_dependency("pcp", proto_pmproxy);
dissector_add_uint_with_preference("tcp.port", PMPROXY_PORT, pmproxy_handle);
}
/*
* Editor modelines - https://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 4
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* vi: set shiftwidth=4 tabstop=8 expandtab:
* :indentSize=4:tabSize=8:noTabs=true:
*/
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