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wireshark/packet-socks.c

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/* packet-socks.c
* Routines for socks versions 4 &5 packet dissection
* Copyright 2000, Jeffrey C. Foster <jfoste@woodward.com>
*
* $Id: packet-socks.c,v 1.58 2004/02/12 21:04:05 guy Exp $
*
* Ethereal - Network traffic analyzer
* By Gerald Combs <gerald@ethereal.com>
* Copyright 1998 Gerald Combs
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
*
* The Version 4 decode is based on SOCKS4.protocol and SOCKS4A.protocol.
* The Version 5 decoder is based upon rfc-1928
* The Version 5 User/Password authentication is based on rfc-1929.
*
* See
*
* http://www.socks.permeo.com/TechnicalResources/ProtocolDocuments.asp
*
* for these and other documents.
*
* Revisions:
*
* 2003-09-18 JCFoster Fixed problem with socks tunnel in socks tunnel
* causing heap overflow because of an infinite loop
* where the socks dissect was call over and over.
*
* Also remove some old code marked with __JUNK__
*
* 2001-01-08 JCFoster Fixed problem with NULL pointer for hash data.
* Now test and exit if hash_info is null.
*/
/* Possible enhancements -
*
* Add GSS-API authentication per rfc-1961
* Add CHAP authentication
* Decode FLAG bits per
* http://archive.socks.permeo.com/draft/draft-ietf-aft-socks-pro-v5-04.txt
* In call_next_dissector, could load the destination address into
* pinfo->src or pinfo->dst structure before calling next dissector.
* remove display_string or at least make it use protocol identifiers
* socks_hash_entry_t needs to handle V5 address type and domain names
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <stdio.h>
#include <string.h>
#include <glib.h>
#include <epan/packet.h>
#include <epan/resolv.h>
#include <epan/conversation.h>
#include "packet-tcp.h"
#include "packet-udp.h"
#include <epan/strutil.h>
#define compare_packet(X) (X == (pinfo->fd->num))
#define get_packet_ptr (pinfo->fd->num)
#define row_pointer_type guint32
#define TCP_PORT_SOCKS 1080
/**************** Socks commands ******************/
#define CONNECT_COMMAND 1
#define BIND_COMMAND 2
#define UDP_ASSOCIATE_COMMAND 3
#define PING_COMMAND 0x80
#define TRACERT_COMMAND 0x81
/********** V5 Authentication methods *************/
#define NO_AUTHENTICATION 0
#define GSS_API_AUTHENTICATION 1
#define USER_NAME_AUTHENTICATION 2
#define CHAP_AUTHENTICATION 3
#define AUTHENTICATION_FAILED 0xff
/* 2003-09-18 JCFoster Fixed problem with socks tunnel in socks tunnel */
static int in_socks_dissector_flag = 0; /* set to 1 to avoid recursive overflow */
/*********** Header field identifiers *************/
static int proto_socks = -1;
static int ett_socks = -1;
static int ett_socks_auth = -1;
static int ett_socks_name = -1;
static int hf_socks_ver = -1;
static int hf_socks_ip_dst = -1;
static int hf_socks_ip6_dst = -1;
static int hf_user_name = -1;
static int hf_socks_dstport = -1;
static int hf_socks_cmd = -1;
static int hf_socks_results = -1;
static int hf_socks_results_4 = -1;
static int hf_socks_results_5 = -1;
/************* Dissector handles ***********/
static dissector_handle_t socks_handle;
static dissector_handle_t socks_udp_handle;
/************* State Machine names ***********/
enum SockState {
None = 0,
Connecting,
V4UserNameWait,
V4NameWait,
V5Command,
V5Reply,
V5BindReply,
UserNameAuth,
UserNameAuthReply,
GssApiAuth,
AuthReply,
Done
};
typedef struct {
int state;
int version;
int command;
int grant;
guint32 port;
guint32 udp_port;
guint32 udp_remote_port;
int connect_offset;
row_pointer_type v4_name_row;
row_pointer_type v4_user_name_row;
row_pointer_type connect_row;
row_pointer_type cmd_reply_row;
row_pointer_type bind_reply_row;
row_pointer_type command_row;
row_pointer_type auth_method_row;
row_pointer_type user_name_auth_row;
row_pointer_type auth_version;
guint32 start_done_row;
guint32 dst_addr; /* this needs to handle IPv6 */
}socks_hash_entry_t;
static char *address_type_table[] = {
"Unknown",
"IPv4",
"Unknown",
"Domain Name",
"IPv6",
"Unknown"
};
/* String table for the V4 reply status messages */
static const value_string reply_table_v4[] = {
{90, "Granted"},
{91, "Rejected or Failed"},
{92, "Rejected because SOCKS server cannot connect to identd on the client"},
{93, "Rejected because the client program and identd report different user-ids"},
{0, NULL}
};
/* String table for the V5 reply status messages */
static const value_string reply_table_v5[] = {
{0, "Succeeded"},
{1, "General SOCKS server failure"},
{2, "Connection not allowed by ruleset"},
{3, "Network unreachable"},
{4, "Host unreachable"},
{5, "Connection refused"},
{6, "TTL expired"},
{7, "Command not supported"},
{8, "Address type not supported"},
{0, NULL},
};
static const value_string cmd_strings[] = {
{0, "Unknow"},
{1, "Connect"},
{2, "Bind"},
{3, "UdpAssociate"},
{0x80, "Ping"},
{0x81, "Traceroute"},
{0, NULL}
};
#define socks_hash_init_count 20
#define socks_hash_val_length (sizeof(socks_hash_entry_t))
static GMemChunk *socks_vals = NULL;
/************************* Support routines ***************************/
static int display_string(tvbuff_t *tvb, int offset,
proto_tree *tree, char *label){
/* display a string with a length, characters encoding */
/* they are displayed under a tree with the name in Label variable */
/* return the length of the string and the length byte */
proto_tree *name_tree;
proto_item *ti;
char temp[ 256];
int length = tvb_get_guint8(tvb, offset);
tvb_memcpy(tvb, (guint8 *)temp, offset+1, length);
temp[ length ] = 0;
ti = proto_tree_add_text(tree, tvb, offset, length + 1,
"%s: %s" , label, temp);
name_tree = proto_item_add_subtree(ti, ett_socks_name);
proto_tree_add_text( name_tree, tvb, offset, 1, "Length: %u", length);
++offset;
proto_tree_add_text( name_tree, tvb, offset, length, "String: %s", temp);
return length + 1;
}
static char *get_auth_method_name( guint Number){
/* return the name of the authenication method */
if ( Number == 0) return "No authentication";
if ( Number == 1) return "GSSAPI";
if ( Number == 2) return "Username/Password";
if ( Number == 3) return "Chap";
if (( Number >= 4) && ( Number <= 0x7f))return "IANA assigned";
if (( Number >= 0x80) && ( Number <= 0xfe)) return "private method";
if ( Number == 0xff) return "no acceptable method";
/* shouldn't reach here */
return "Bad method number (not 0-0xff)";
}
static char *get_command_name( guint Number){
/* return the name of the command as a string */
if ( Number == 0) return "Unknow";
if ( Number == 1) return "Connect";
if ( Number == 2) return "Bind";
if ( Number == 3) return "UdpAssociate";
if ( Number == 0x80) return "Ping";
if ( Number == 0x81) return "Traceroute";
return "Unknown";
}
static int display_address(tvbuff_t *tvb, int offset, proto_tree *tree) {
/* decode and display the v5 address, return offset of next byte */
int a_type = tvb_get_guint8(tvb, offset);
proto_tree_add_text( tree, tvb, offset, 1,
"Address Type: %d (%s)", a_type,
address_type_table[ MIN( (guint) a_type,
array_length( address_type_table)-1) ]);
++offset;
if ( a_type == 1){ /* IPv4 address */
proto_tree_add_item( tree, hf_socks_ip_dst, tvb, offset,
4, FALSE);
offset += 4;
}
else if ( a_type == 3){ /* domain name address */
offset += display_string(tvb, offset, tree,
"Remote name");
}
else if ( a_type == 4){ /* IPv6 address */
proto_tree_add_item( tree, hf_socks_ip6_dst, tvb, offset,
16, FALSE);
offset += 16;
}
return offset;
}
static int get_address_v5(tvbuff_t *tvb, int offset,
socks_hash_entry_t *hash_info) {
/* decode the v5 address and return offset of next byte */
/*XXX this needs to handle IPV6 and domain name addresses */
int a_type = tvb_get_guint8(tvb, offset++);
if ( a_type == 1){ /* IPv4 address */
if ( hash_info)
tvb_memcpy(tvb, (guint8 *)&hash_info->dst_addr,
offset, 4);
offset += 4;
}
else if ( a_type == 4) /* IPv6 address */
offset += 16;
else if ( a_type == 3) /* domain name address */
offset += tvb_get_guint8(tvb, offset) + 1;
return offset;
}
/********************* V5 UDP Associate handlers ***********************/
static void
socks_udp_dissector(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) {
/* Conversation dissector called from UDP dissector. Decode and display */
/* the socks header, the pass the rest of the data to the udp port */
/* decode routine to handle the payload. */
int offset = 0;
guint32 *ptr;
socks_hash_entry_t *hash_info;
conversation_t *conversation;
proto_tree *socks_tree;
proto_item *ti;
conversation = find_conversation( &pinfo->src, &pinfo->dst, pinfo->ptype,
pinfo->srcport, pinfo->destport, 0);
g_assert( conversation); /* should always find a conversation */
hash_info = conversation_get_proto_data(conversation, proto_socks);
if (check_col(pinfo->cinfo, COL_PROTOCOL))
col_set_str(pinfo->cinfo, COL_PROTOCOL, "Socks");
if (check_col(pinfo->cinfo, COL_INFO))
col_add_fstr(pinfo->cinfo, COL_INFO, "Version: 5, UDP Associated packet");
if ( tree) {
ti = proto_tree_add_protocol_format( tree, proto_socks, tvb,
offset, -1, "Socks" );
socks_tree = proto_item_add_subtree(ti, ett_socks);
proto_tree_add_text( socks_tree, tvb, offset, 2, "Reserved");
offset += 2;
proto_tree_add_text( socks_tree, tvb, offset, 1, "Fragment Number: %u", tvb_get_guint8(tvb, offset));
++offset;
offset = display_address( tvb, offset, socks_tree);
hash_info->udp_remote_port = tvb_get_ntohs(tvb, offset);
proto_tree_add_uint( socks_tree, hf_socks_dstport, tvb,
offset, 2, hash_info->udp_remote_port);
offset += 2;
}
else { /* no tree, skip past the socks header */
offset += 3;
offset = get_address_v5( tvb, offset, 0) + 2;
}
/* set pi src/dst port and call the udp sub-dissector lookup */
if ( pinfo->srcport == hash_info->port)
ptr = &pinfo->destport;
else
ptr = &pinfo->srcport;
*ptr = hash_info->udp_remote_port;
decode_udp_ports( tvb, offset, pinfo, tree, pinfo->srcport, pinfo->destport, -1);
*ptr = hash_info->udp_port;
}
static void
new_udp_conversation( socks_hash_entry_t *hash_info, packet_info *pinfo){
conversation_t *conversation = conversation_new( &pinfo->src, &pinfo->dst, PT_UDP,
hash_info->udp_port, hash_info->port, 0);
g_assert( conversation);
conversation_add_proto_data(conversation, proto_socks, hash_info);
conversation_set_dissector(conversation, socks_udp_handle);
}
/**************** Protocol Tree Display routines ******************/
static void
display_socks_v4(tvbuff_t *tvb, int offset, packet_info *pinfo,
proto_tree *tree, socks_hash_entry_t *hash_info) {
/* Display the protocol tree for the V4 version. This routine uses the */
/* stored conversation information to decide what to do with the row. */
/* Per packet information would have been better to do this, but we */
/* didn't have that when I wrote this. And I didn't expect this to get */
/* so messy. */
guint command;
/* Display command from client */
if (compare_packet( hash_info->connect_row)){
proto_tree_add_text( tree, tvb, offset, 1,
"Version: %u", hash_info->version);
++offset;
command = tvb_get_guint8(tvb, offset);
proto_tree_add_text( tree, tvb, offset, 1,
"Command: %u (%s)", command,
get_command_name( command));
++offset;
/* Do remote port */
proto_tree_add_item( tree, hf_socks_dstport, tvb, offset, 2,
FALSE);
offset += 2;
/* Do destination address */
proto_tree_add_item( tree, hf_socks_ip_dst, tvb, offset,
4, FALSE);
offset += 4;
/*XXX check this, needs to do length checking */
/* Should perhaps do TCP reassembly as well */
if ( tvb_offset_exists(tvb, offset)) {
/* display user name */
proto_tree_add_string( tree, hf_user_name, tvb, offset,
tvb_strsize(tvb, offset),
tvb_get_ptr(tvb, offset, -1));
}
}
/*Display command response from server*/
else if ( compare_packet( hash_info->cmd_reply_row)){
proto_tree_add_item( tree, hf_socks_ver, tvb, offset, 1,
FALSE);
++offset;
/* Do results code */
proto_tree_add_item( tree, hf_socks_results_4, tvb, offset, 1, FALSE);
proto_tree_add_item_hidden(tree, hf_socks_results, tvb, offset, 1, FALSE);
++offset;
/* Do remote port */
proto_tree_add_item( tree, hf_socks_dstport, tvb, offset, 2,
FALSE);
offset += 2;
/* Do remote address */
proto_tree_add_item( tree, hf_socks_ip_dst, tvb, offset, 4,
FALSE);
}
else if ( compare_packet( hash_info->v4_user_name_row)){
/*XXX check this, needs to do length checking */
/* Should perhaps do TCP reassembly as well */
if ( tvb_offset_exists(tvb, offset)) {
proto_tree_add_text( tree, tvb, offset,
tvb_strsize(tvb, offset),
"User Name: %s", tvb_get_ptr(tvb, offset, -1));
}
}
}
static void
display_socks_v5(tvbuff_t *tvb, int offset, packet_info *pinfo,
proto_tree *tree, socks_hash_entry_t *hash_info) {
/* Display the protocol tree for the version. This routine uses the */
/* stored conversation information to decide what to do with the row. */
/* Per packet information would have been better to do this, but we */
/* didn't have that when I wrote this. And I didn't expect this to get */
/* so messy. */
unsigned int i, command;
guint temp;
char *AuthMethodStr;
guint8 auth_status;
proto_tree_add_item( tree, hf_socks_ver, tvb, offset, 1, FALSE);
++offset;
if (compare_packet( hash_info->connect_row)){
proto_tree *AuthTree;
proto_item *ti;
temp = tvb_get_guint8(tvb, offset); /* Get Auth method count */
/* build auth tree */
ti = proto_tree_add_text( tree, tvb, offset, -1,
"Client Authentication Methods");
AuthTree = proto_item_add_subtree(ti, ett_socks_auth);
proto_tree_add_text( AuthTree, tvb, offset, 1,
"Count: %u", temp);
++offset;
for( i = 0; i < temp; ++i) {
AuthMethodStr = get_auth_method_name(
tvb_get_guint8( tvb, offset));
proto_tree_add_text( AuthTree, tvb, offset, 1,
"Method[%u]: %u (%s)", i,
tvb_get_guint8( tvb, offset), AuthMethodStr);
++offset;
}
proto_item_set_end( ti, tvb, offset);
return;
} /* Get accepted auth method */
else if (compare_packet( hash_info->auth_method_row)) {
proto_tree_add_text( tree, tvb, offset, 1,
"Accepted Auth Method: 0x%0x (%s)", tvb_get_guint8( tvb, offset),
get_auth_method_name( tvb_get_guint8( tvb, offset)));
return;
} /* handle user/password auth */
else if (compare_packet( hash_info->user_name_auth_row)) {
/* process user name */
offset += display_string( tvb, offset, tree,
"User name");
/* process password */
offset += display_string( tvb, offset, tree,
"Password");
}
/* command to the server */
/* command response from server */
else if (compare_packet( hash_info->auth_version)) {
auth_status = tvb_get_guint8(tvb, offset);
if(auth_status != 0)
proto_tree_add_text( tree, tvb, offset, 1, "Status: %u (failure)", auth_status);
else
proto_tree_add_text( tree, tvb, offset, 1, "Status: success");
offset ++;
}
else if ((compare_packet( hash_info->command_row)) ||
(compare_packet( hash_info->cmd_reply_row)) ||
(compare_packet( hash_info->bind_reply_row))){
command = tvb_get_guint8(tvb, offset);
if (compare_packet( hash_info->command_row))
proto_tree_add_uint( tree, hf_socks_cmd, tvb, offset, 1,
command);
else {
proto_tree_add_item( tree, hf_socks_results_5, tvb, offset, 1, FALSE);
proto_tree_add_item_hidden(tree, hf_socks_results, tvb, offset, 1, FALSE);
}
++offset;
proto_tree_add_text( tree, tvb, offset, 1,
"Reserved: 0x%0x (should = 0x00)", tvb_get_guint8(tvb, offset));
++offset;
offset = display_address(tvb, offset, tree);
/*XXX Add remote port for search somehow */
/* Do remote port */
proto_tree_add_text( tree, tvb, offset, 2,
"%sPort: %u",
(compare_packet( hash_info->bind_reply_row) ?
"Remote Host " : ""),
tvb_get_ntohs(tvb, offset));
}
}
/**************** Decoder State Machines ******************/
static guint
state_machine_v4( socks_hash_entry_t *hash_info, tvbuff_t *tvb,
int offset, packet_info *pinfo) {
/* Decode V4 protocol. This is done on the first pass through the */
/* list. Based upon the current state, decode the packet and determine */
/* what the next state should be. If we had per packet information, */
/* this would be the place to load them up. */
if ( hash_info->state == None) { /* new connection */
if (check_col(pinfo->cinfo, COL_INFO))
col_append_str(pinfo->cinfo, COL_INFO, " Connect to server request");
hash_info->state = Connecting; /* change state */
hash_info->command = tvb_get_guint8(tvb, offset + 1);
/* get remote port */
if ( hash_info->command == CONNECT_COMMAND)
hash_info->port = tvb_get_ntohs(tvb, offset + 2);
/* get remote address */
tvb_memcpy(tvb, (guint8 *)&hash_info->dst_addr, offset + 4, 4);
/* save the packet pointer */
hash_info->connect_row = get_packet_ptr;
/* skip past this stuff */
hash_info->connect_offset = offset + 8;
offset += 8;
if ( !tvb_offset_exists(tvb, offset)) { /* if no user name */
/* change state */
hash_info->state = V4UserNameWait;
/*
* XXX - add 1, or leave it alone?
* We were adding "strlen(...) + 1".
*/
hash_info->connect_offset += 1;
} else {
/*
* Add in the length of the user name.
* XXX - what if the user name is split between
* TCP segments?
*/
hash_info->connect_offset += tvb_strsize(tvb, offset);
}
if ( !hash_info->dst_addr){ /* if no dest address */
/* if more data */
if ( tvb_offset_exists(tvb, hash_info->connect_offset)) {
/*XXX copy remote name here ??? */
hash_info->state = Connecting;
}
else
hash_info->state = V4NameWait;
}
/* waiting for V4 user name */
}else if ( hash_info->state == V4UserNameWait){
if (check_col(pinfo->cinfo, COL_INFO))
col_append_str(pinfo->cinfo, COL_INFO, " Connect Request (User name)");
hash_info->v4_user_name_row = get_packet_ptr;
/*XXX may need to check for domain name here */
hash_info->state = Connecting;
}
/* waiting for V4 domain name */
else if ( hash_info->state == V4NameWait){
hash_info->v4_name_row = get_packet_ptr;
hash_info->state = Connecting;
}
else if ( hash_info->state == Connecting){
if (check_col(pinfo->cinfo, COL_INFO))
col_append_str(pinfo->cinfo, COL_INFO, " Connect Response");
/* save packet pointer */
hash_info->cmd_reply_row = get_packet_ptr;
hash_info->state = Done; /* change state */
offset = offset + 8;
}
return offset;
}
static void
state_machine_v5( socks_hash_entry_t *hash_info, tvbuff_t *tvb,
int offset, packet_info *pinfo) {
/* Decode V5 protocol. This is done on the first pass through the */
/* list. Based upon the current state, decode the packet and determine */
/* what the next state should be. If we had per packet information, */
/* this would be the place to load them up. */
int temp;
if ( hash_info->state == None) {
if (check_col(pinfo->cinfo, COL_INFO))
col_append_str(pinfo->cinfo, COL_INFO, " Connect to server request");
hash_info->state = Connecting; /* change state */
hash_info->connect_row = get_packet_ptr;
temp = tvb_get_guint8(tvb, offset + 1);
/* skip past auth methods */
offset = hash_info->connect_offset = offset + 1 + temp;
}
else if ( hash_info->state == Connecting){
guint AuthMethod = tvb_get_guint8(tvb, offset + 1);
if (check_col(pinfo->cinfo, COL_INFO))
col_append_str(pinfo->cinfo, COL_INFO, " Connect to server response");
hash_info->auth_method_row = get_packet_ptr;
if ( AuthMethod == NO_AUTHENTICATION)
hash_info->state = V5Command;
else if ( AuthMethod == USER_NAME_AUTHENTICATION)
hash_info->state = UserNameAuth;
else if ( AuthMethod == GSS_API_AUTHENTICATION)
/*XXX should be this hash_info->state = GssApiAuth; */
hash_info->state = Done;
else hash_info->state = Done; /*Auth failed or error*/
}
else if ( hash_info->state == V5Command) { /* Handle V5 Command */
guint temp;
hash_info->command = tvb_get_guint8(tvb, offset + 1); /* get command */
if (check_col(pinfo->cinfo, COL_INFO))
col_append_fstr(pinfo->cinfo, COL_INFO, " Command Request - %s",
get_command_name(hash_info->command));
hash_info->state = V5Reply;
hash_info->command_row = get_packet_ptr;
offset += 3; /* skip to address type */
offset = get_address_v5(tvb, offset, hash_info);
temp = tvb_get_guint8(tvb, offset);
if (( hash_info->command == CONNECT_COMMAND) ||
( hash_info->command == UDP_ASSOCIATE_COMMAND))
/* get remote port */
hash_info->port = tvb_get_ntohs(tvb, offset);
}
else if ( hash_info->state == V5Reply) { /* V5 Command Reply */
if (check_col(pinfo->cinfo, COL_INFO))
col_append_fstr(pinfo->cinfo, COL_INFO, " Command Response - %s",
get_command_name(hash_info->command));
hash_info->cmd_reply_row = get_packet_ptr;
if (( hash_info->command == CONNECT_COMMAND) ||
(hash_info->command == PING_COMMAND) ||
(hash_info->command == TRACERT_COMMAND))
hash_info->state = Done;
else if ( hash_info->command == BIND_COMMAND)
hash_info->state = V5BindReply;
else if ( hash_info->command == UDP_ASSOCIATE_COMMAND){
offset += 3; /* skip to address type */
offset = get_address_v5(tvb, offset, hash_info);
/* save server udp port and create udp conversation */
hash_info->udp_port = tvb_get_ntohs(tvb, offset);
if (!pinfo->fd->flags.visited)
new_udp_conversation( hash_info, pinfo);
/*XXX may need else statement to handle unknows and generate error message */
}
}
else if ( hash_info->state == V5BindReply) { /* V5 Bind Second Reply */
if (check_col(pinfo->cinfo, COL_INFO))
col_append_str(pinfo->cinfo, COL_INFO, " Command Response: Bind remote host info");
hash_info->bind_reply_row = get_packet_ptr;
hash_info->state = Done;
}
else if ( hash_info->state == UserNameAuth) { /* Handle V5 User Auth*/
hash_info->auth_version = get_packet_ptr;
if (check_col(pinfo->cinfo, COL_INFO))
col_append_str(pinfo->cinfo, COL_INFO,
" User authentication request");
hash_info->user_name_auth_row = get_packet_ptr;
hash_info->state = AuthReply;
}
else if ( hash_info->state == AuthReply){ /* V5 User Auth reply */
hash_info->auth_version = get_packet_ptr;
if (check_col(pinfo->cinfo, COL_INFO))
col_append_str(pinfo->cinfo, COL_INFO, " User authentication reply");
hash_info->state = V5Command;
}
}
static void
display_ping_and_tracert(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree, socks_hash_entry_t *hash_info) {
/* Display the ping/trace_route conversation */
const guchar *data, *dataend;
const guchar *lineend, *eol;
int linelen;
/* handle the end command */
if ( pinfo->destport == TCP_PORT_SOCKS){
if (check_col(pinfo->cinfo, COL_INFO))
col_append_str(pinfo->cinfo, COL_INFO, ", Terminate Request");
if ( tree)
proto_tree_add_text(tree, tvb, offset, 1,
(hash_info->command == PING_COMMAND) ?
"Ping: End command" :
"Traceroute: End command");
}
else{ /* display the PING or Traceroute results */
if (check_col(pinfo->cinfo, COL_INFO))
col_append_str(pinfo->cinfo, COL_INFO, ", Results");
if ( tree){
proto_tree_add_text(tree, tvb, offset, -1,
(hash_info->command == PING_COMMAND) ?
"Ping Results:" :
"Traceroute Results");
data = tvb_get_ptr(tvb, offset, -1);
dataend = data + tvb_length_remaining(tvb, offset);
while (data < dataend) {
lineend = find_line_end(data, dataend, &eol);
linelen = lineend - data;
proto_tree_add_text( tree, tvb, offset, linelen,
"%s", format_text(data, linelen));
offset += linelen;
data = lineend;
}
}
}
}
static void clear_in_socks_dissector_flag(void *dummy _U_)
{
in_socks_dissector_flag = 0; /* avoid recursive overflow */
}
static void call_next_dissector(tvbuff_t *tvb, int offset, packet_info *pinfo,
proto_tree *tree, proto_tree *socks_tree,
socks_hash_entry_t *hash_info)
{
/* Display the results for PING and TRACERT extensions or */
/* Call TCP dissector for the port that was passed during the */
/* connect process */
/* Load pointer to pinfo->XXXport depending upon the direction, */
/* change pinfo port to the remote port, call next dissecotr to decode */
/* the payload, and restore the pinfo port after that is done. */
guint32 *ptr;
struct tcpinfo *tcpinfo = pinfo->private_data;
guint16 save_can_desegment;
if (( hash_info->command == PING_COMMAND) ||
( hash_info->command == TRACERT_COMMAND))
display_ping_and_tracert(tvb, offset, pinfo, tree, hash_info);
else { /* call the tcp port decoder to handle the payload */
/*XXX may want to load dest address here */
if ( pinfo->destport == TCP_PORT_SOCKS)
ptr = &pinfo->destport;
else
ptr = &pinfo->srcport;
*ptr = hash_info->port;
/* 2003-09-18 JCFoster Fixed problem with socks tunnel in socks tunnel */
in_socks_dissector_flag = 1; /* avoid recursive overflow */
CLEANUP_PUSH(clear_in_socks_dissector_flag, NULL);
save_can_desegment = pinfo->can_desegment;
pinfo->can_desegment = pinfo->saved_can_desegment;
dissect_tcp_payload(tvb, pinfo, offset, tcpinfo->seq,
tcpinfo->nxtseq, pinfo->srcport, pinfo->destport,
tree, socks_tree);
pinfo->can_desegment = save_can_desegment;
CLEANUP_CALL_AND_POP;
*ptr = TCP_PORT_SOCKS;
}
}
static void
dissect_socks(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) {
int offset = 0;
proto_tree *socks_tree = NULL;
proto_item *ti;
socks_hash_entry_t *hash_info;
conversation_t *conversation;
/* 2003-09-18 JCFoster Fixed problem with socks tunnel in socks tunnel */
/* avoid recursive overflow */
if ( in_socks_dissector_flag) {
return;
}
conversation = find_conversation( &pinfo->src, &pinfo->dst, pinfo->ptype,
pinfo->srcport, pinfo->destport, 0);
if ( !conversation){
conversation = conversation_new( &pinfo->src, &pinfo->dst, pinfo->ptype,
pinfo->srcport, pinfo->destport, 0);
}
hash_info = conversation_get_proto_data(conversation,proto_socks);
if ( !hash_info){
hash_info = g_mem_chunk_alloc(socks_vals);
hash_info->start_done_row = G_MAXINT;
hash_info->state = None;
hash_info->port = 0;
hash_info->version = tvb_get_guint8(tvb, offset); /* get version*/
if (( hash_info->version != 4) && /* error test version */
( hash_info->version != 5))
hash_info->state = Done;
conversation_add_proto_data(conversation, proto_socks,
hash_info);
/* set dissector for now */
conversation_set_dissector(conversation, socks_handle);
}
/* display summary window information */
if (check_col(pinfo->cinfo, COL_PROTOCOL))
col_set_str(pinfo->cinfo, COL_PROTOCOL, "Socks");
if (check_col(pinfo->cinfo, COL_INFO)){
if (( hash_info->version == 4) || ( hash_info->version == 5)){
col_add_fstr(pinfo->cinfo, COL_INFO, "Version: %d",
hash_info->version);
}
else /* unknown version display error */
col_set_str(pinfo->cinfo, COL_INFO, "Unknown");
if ( hash_info->command == PING_COMMAND)
col_append_str(pinfo->cinfo, COL_INFO, ", Ping Req");
if ( hash_info->command == TRACERT_COMMAND)
col_append_str(pinfo->cinfo, COL_INFO, ", Traceroute Req");
/*XXX if ( hash_info->port != -1) */
if ( hash_info->port != 0)
col_append_fstr(pinfo->cinfo, COL_INFO, ", Remote Port: %u",
hash_info->port);
}
/* run state machine if needed */
if ((hash_info->state != Done) && ( !pinfo->fd->flags.visited)){
if ( hash_info->version == 4)
state_machine_v4( hash_info, tvb, offset, pinfo);
else if ( hash_info->version == 5)
state_machine_v5( hash_info, tvb, offset, pinfo);
if (hash_info->state == Done) { /* if done now */
hash_info->start_done_row = pinfo->fd->num;
}
}
/* if proto tree, decode and display */
if (tree) {
ti = proto_tree_add_item( tree, proto_socks, tvb, offset, -1,
FALSE );
socks_tree = proto_item_add_subtree(ti, ett_socks);
if ( hash_info->version == 4)
display_socks_v4(tvb, offset, pinfo, socks_tree,
hash_info);
else if ( hash_info->version == 5)
display_socks_v5(tvb, offset, pinfo, socks_tree,
hash_info);
/* if past startup, add the faked stuff */
if ( pinfo->fd->num > hash_info->start_done_row){
/* add info to tree */
proto_tree_add_text( socks_tree, tvb, offset, 0,
"Command: %d (%s)", hash_info->command,
get_command_name(hash_info->command));
proto_tree_add_ipv4( socks_tree, hf_socks_ip_dst, tvb,
offset, 0, hash_info->dst_addr);
/* no fake address for ping & traceroute */
if (( hash_info->command != PING_COMMAND) &&
( hash_info->command != TRACERT_COMMAND)){
proto_tree_add_uint( socks_tree, hf_socks_dstport, tvb,
offset, 0, hash_info->port);
}
}
}
/* call next dissector if ready */
if ( pinfo->fd->num > hash_info->start_done_row){
call_next_dissector(tvb, offset, pinfo, tree, socks_tree,
hash_info);
}
}
static void socks_reinit( void){
/* Do the cleanup work when a new pass through the packet list is */
/* performed. Reset the highest row seen counter and re-initialize the */
/* conversation memory chunks. */
if (socks_vals)
g_mem_chunk_destroy(socks_vals);
socks_vals = g_mem_chunk_new("socks_vals", socks_hash_val_length,
socks_hash_init_count * socks_hash_val_length,
G_ALLOC_AND_FREE);
}
void
proto_register_socks( void){
/*** Prep the socks protocol, register it and a initialization routine */
/* to clear the hash stuff. */
static gint *ett[] = {
&ett_socks,
&ett_socks_auth,
&ett_socks_name
};
static hf_register_info hf[] = {
{ &hf_socks_ver,
{ "Version", "socks.version", FT_UINT8, BASE_DEC, NULL,
0x0, "", HFILL
}
},
{ &hf_socks_ip_dst,
{ "Remote Address", "socks.dst", FT_IPv4, BASE_NONE, NULL,
0x0, "", HFILL
}
},
{ &hf_socks_ip6_dst,
{ "Remote Address(ipv6)", "socks.dstV6", FT_IPv6, BASE_NONE, NULL,
0x0, "", HFILL
}
},
{ &hf_user_name,
{ "User Name", "socks.username", FT_STRING, BASE_NONE,
NULL, 0x0, "", HFILL
}
},
{ &hf_socks_dstport,
{ "Remote Port", "socks.dstport", FT_UINT16,
BASE_DEC, NULL, 0x0, "", HFILL
}
},
{ &hf_socks_cmd,
{ "Command", "socks.command", FT_UINT8,
BASE_DEC, VALS(cmd_strings), 0x0, "", HFILL
}
},
{ &hf_socks_results_4,
{ "Results(V4)", "socks.results_v4", FT_UINT8,
BASE_DEC, VALS(reply_table_v4), 0x0, "", HFILL
}
},
{ &hf_socks_results_5,
{ "Results(V5)", "socks.results_v5", FT_UINT8,
BASE_DEC, VALS(reply_table_v5), 0x0, "", HFILL
}
},
{ &hf_socks_results,
{ "Results(V5)", "socks.results", FT_UINT8,
BASE_DEC, NULL, 0x0, "", HFILL
}
}
};
proto_socks = proto_register_protocol (
"Socks Protocol", "Socks", "socks");
proto_register_field_array(proto_socks, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
register_init_routine( &socks_reinit); /* register re-init routine */
socks_udp_handle = create_dissector_handle(socks_udp_dissector,
proto_socks);
socks_handle = create_dissector_handle(dissect_socks, proto_socks);
}
void
proto_reg_handoff_socks(void) {
/* dissector install routine */
dissector_add("tcp.port", TCP_PORT_SOCKS, socks_handle);
}
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