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wireshark/packet-rlogin.c

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/* packet-rlogin.c
* Routines for unix rlogin packet dissection
* Copyright 2000, Jeffrey C. Foster <jfoste@woodward.com>
*
* $Id: packet-rlogin.c,v 1.28 2002/08/28 21:00:29 jmayer Exp $
*
* Ethereal - Network traffic analyzer
* By Gerald Combs <gerald@ethereal.com>
* Copyright 1998 Gerald Combs
*
* Based upon RFC-1282 - BSD Rlogin
*
* 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.
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <stdio.h>
#include <string.h>
#include <glib.h>
#include <epan/packet.h>
#include <epan/conversation.h>
#include "packet-tcp.h"
#define TCP_PORT_RLOGIN 513
static int proto_rlogin = -1;
static int ett_rlogin = -1;
static int ett_rlogin_window = -1;
static int ett_rlogin_user_info = -1;
static int ett_rlogin_window_rows = -1;
static int ett_rlogin_window_cols = -1;
static int ett_rlogin_window_x_pixels = -1;
static int ett_rlogin_window_y_pixels = -1;
static int hf_user_info = -1;
static int hf_window_info = -1;
static int hf_window_info_rows = -1;
static int hf_window_info_cols = -1;
static int hf_window_info_x_pixels = -1;
static int hf_window_info_y_pixels = -1;
#define RLOGIN_PORT 513
#define NAME_LEN 32
typedef struct {
int state;
guint32 info_framenum;
char name[ NAME_LEN];
} rlogin_hash_entry_t;
#define NONE 0
#define USER_INFO_WAIT 1
#define DONE 2
#define BAD 2
static GMemChunk *rlogin_vals = NULL;
#define rlogin_hash_init_count 20
static guint32 last_abs_sec = 0;
static guint32 last_abs_usec= 0;
static void
rlogin_init(void)
{
/* Routine to initialize rlogin protocol before each capture or filter pass. */
/* Release any memory if needed. Then setup the memory chunks. */
last_abs_sec = 0;
last_abs_usec= 0;
if (rlogin_vals)
g_mem_chunk_destroy(rlogin_vals);
rlogin_vals = g_mem_chunk_new("rlogin_vals",
sizeof( rlogin_hash_entry_t),
rlogin_hash_init_count * sizeof( rlogin_hash_entry_t),
G_ALLOC_AND_FREE);
}
/**************** Decoder State Machine ******************/
static void
rlogin_state_machine( rlogin_hash_entry_t *hash_info, tvbuff_t *tvb,
packet_info *pinfo)
{
guint length;
gint stringlen;
/* rlogin stream decoder */
/* Just watched for second packet from client with the user name and */
/* terminal type information. */
if ( pinfo->destport != RLOGIN_PORT) /* not from client */
return;
/* exit if not needed */
if (( hash_info->state == DONE) || ( hash_info->state == BAD))
return;
/* test timestamp */
if (( last_abs_sec > pinfo->fd->abs_secs) ||
(( last_abs_sec == pinfo->fd->abs_secs) &&
( last_abs_usec >= pinfo->fd->abs_usecs)))
return;
last_abs_sec = pinfo->fd->abs_secs; /* save timestamp */
last_abs_usec = pinfo->fd->abs_usecs;
length = tvb_length(tvb);
if ( length == 0) /* exit if no data */
return;
if ( hash_info->state == NONE){ /* new connection*/
if (tvb_get_guint8(tvb, 0) != '\0') {
/*
* We expected a NUL, but didn't get one; quit.
*/
hash_info->state = DONE;
return;
}
else {
if (length <= 1) /* if no data */
hash_info->state = USER_INFO_WAIT;
else {
hash_info->state = DONE;
hash_info->info_framenum = pinfo->fd->num;
}
}
} /* expect user data here */
/*$$$ may need to do more checking here */
else if ( hash_info->state == USER_INFO_WAIT) {
hash_info->state = DONE;
hash_info->info_framenum = pinfo->fd->num;
/* save name for later*/
stringlen = tvb_strnlen(tvb, 0, NAME_LEN);
if (stringlen == -1)
stringlen = NAME_LEN - 1; /* no '\0' found */
else if (stringlen > NAME_LEN - 1)
stringlen = NAME_LEN - 1; /* name too long */
tvb_memcpy(tvb, (guint8 *)hash_info->name, 0, stringlen);
hash_info->name[stringlen] = '\0';
if (check_col(pinfo->cinfo, COL_INFO)) /* update summary */
col_append_str(pinfo->cinfo, COL_INFO,
", User information");
}
}
static void rlogin_display( rlogin_hash_entry_t *hash_info, tvbuff_t *tvb,
packet_info *pinfo, proto_tree *tree, struct tcpinfo *tcpinfo)
{
/* Display the proto tree */
int offset = 0;
proto_tree *rlogin_tree, *user_info_tree, *window_tree;
proto_item *ti;
guint length;
int str_len;
gint ti_offset;
proto_item *user_info_item, *window_info_item;
ti = proto_tree_add_item( tree, proto_rlogin, tvb, 0, -1, FALSE);
rlogin_tree = proto_item_add_subtree(ti, ett_rlogin);
length = tvb_length(tvb);
if ( length == 0) /* exit if no captured data */
return;
/*
* XXX - this works only if the urgent pointer points to something
* in this segment; to make it work if the urgent pointer points
* to something past this segment, we'd have to remember the urgent
* pointer setting for this conversation.
*/
if ( tcpinfo->urgent && /* if urgent pointer set */
length >= tcpinfo->urgent_pointer) { /* and it's in this frame */
int urgent_offset = tcpinfo->urgent_pointer - 1;
guint8 Temp = tvb_get_guint8(tvb, urgent_offset);
if (urgent_offset > offset) /* check for data in front */
proto_tree_add_text( rlogin_tree, tvb, offset,
urgent_offset, "Data");
proto_tree_add_text( rlogin_tree, tvb, urgent_offset, 1,
"Control byte: %u (%s)",
Temp,
(Temp == 0x02) ? "Clear buffer" :
(Temp == 0x10) ? "Raw mode" :
(Temp == 0x20) ? "Cooked mode" :
(Temp == 0x80) ? "Window size request" :
"Unknown");
offset = urgent_offset + 1; /* adjust offset */
}
else if ( tvb_get_guint8(tvb, offset) == '\0'){ /* startup */
if ( pinfo->srcport== RLOGIN_PORT) /* from server */
proto_tree_add_text(rlogin_tree, tvb, offset, 1,
"Startup info received flag (0x00)");
else
proto_tree_add_text(rlogin_tree, tvb, offset, 1,
"Client Startup Flag (0x00)");
++offset;
}
if (!tvb_offset_exists(tvb, offset))
return; /* No more data to check */
if ( hash_info->info_framenum == pinfo->fd->num){
/*
* First frame of conversation, hence user info?
*/
user_info_item = proto_tree_add_item( rlogin_tree, hf_user_info, tvb,
offset, -1, FALSE);
/*
* Do server user name.
*/
str_len = tvb_strsize(tvb, offset);
user_info_tree = proto_item_add_subtree( user_info_item,
ett_rlogin_user_info);
proto_tree_add_text(user_info_tree, tvb, offset, str_len,
"Server User Name: %.*s", str_len - 1,
tvb_get_ptr(tvb, offset, str_len - 1));
offset += str_len;
/*
* Do client user name.
*/
str_len = tvb_strsize(tvb, offset);
proto_tree_add_text(user_info_tree, tvb, offset, str_len,
"Client User Name: %.*s", str_len - 1,
tvb_get_ptr(tvb, offset, str_len - 1));
offset += str_len;
/*
* Do terminal type/speed.
*/
str_len = tvb_strsize(tvb, offset);
proto_tree_add_text(user_info_tree, tvb, offset, str_len,
"Terminal Type/Speed: %.*s", str_len - 1,
tvb_get_ptr(tvb, offset, str_len - 1));
offset += str_len;
}
if (!tvb_offset_exists(tvb, offset))
return; /* No more data to check */
/* test for terminal information, the data will have 2 0xff bytes */
/* look for first 0xff byte */
ti_offset = tvb_find_guint8(tvb, offset, -1, 0xff);
if (ti_offset != -1 &&
tvb_bytes_exist(tvb, ti_offset + 1, 1) &&
tvb_get_guint8(tvb, ti_offset + 1) == 0xff) {
/*
* Found terminal info.
*/
if (ti_offset > offset) {
/*
* There's data before the terminal info.
*/
proto_tree_add_text( rlogin_tree, tvb, offset,
(ti_offset - offset), "Data");
offset = ti_offset;
}
window_info_item = proto_tree_add_item(rlogin_tree,
hf_window_info, tvb, offset, 12, FALSE );
window_tree = proto_item_add_subtree(window_info_item,
ett_rlogin_window);
proto_tree_add_text(window_tree, tvb, offset, 2,
"Magic Cookie: (0xff, 0xff)");
offset += 2;
proto_tree_add_text(window_tree, tvb, offset, 2,
"Window size marker: 'ss'");
offset += 2;
proto_tree_add_item(window_tree, hf_window_info_rows, tvb,
offset, 2, FALSE);
offset += 2;
proto_tree_add_item(window_tree, hf_window_info_cols, tvb,
offset, 2, FALSE);
offset += 2;
proto_tree_add_item(window_tree, hf_window_info_x_pixels, tvb,
offset, 2, FALSE);
offset += 2;
proto_tree_add_item(window_tree, hf_window_info_y_pixels, tvb,
offset, 2, FALSE);
offset += 2;
}
if (tvb_offset_exists(tvb, offset)) {
/*
* There's more data in the frame.
*/
proto_tree_add_text(rlogin_tree, tvb, offset, -1, "Data");
}
}
static void
dissect_rlogin(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
struct tcpinfo *tcpinfo = pinfo->private_data;
conversation_t *conversation;
rlogin_hash_entry_t *hash_info;
guint length;
gint ti_offset;
/* Lookup this connection*/
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_rlogin);
if ( !hash_info) {
hash_info = g_mem_chunk_alloc(rlogin_vals);
hash_info->state = NONE;
hash_info->info_framenum = 0; /* no frame has the number 0 */
hash_info->name[ 0] = 0;
conversation_add_proto_data(conversation, proto_rlogin,
hash_info);
}
if (check_col(pinfo->cinfo, COL_PROTOCOL)) /* update protocol */
col_set_str(pinfo->cinfo, COL_PROTOCOL, "Rlogin");
if (check_col(pinfo->cinfo, COL_INFO)){ /* display packet info*/
char temp[1000];
col_clear(pinfo->cinfo, COL_INFO);
if ( hash_info->name[0]) {
strcpy( temp, "User name: ");
strcat( temp, hash_info->name);
strcat( temp, ", ");
}
else
temp[0] = 0;
length = tvb_length(tvb);
if (length != 0) {
if ( tvb_get_guint8(tvb, 0) == '\0')
strcat( temp, "Start Handshake");
else if ( tcpinfo->urgent &&
length >= tcpinfo->urgent_pointer )
strcat( temp, "Control Message");
else { /* check for terminal info */
ti_offset = tvb_find_guint8(tvb, 0, -1, 0xff);
if (ti_offset != -1 &&
tvb_bytes_exist(tvb, ti_offset + 1, 1) &&
tvb_get_guint8(tvb, ti_offset + 1) == 0xff)
strcat( temp, "Terminal Info");
else {
int i;
int bytes_to_copy;
strcat( temp, "Data: ");
i = strlen( temp);
bytes_to_copy = tvb_length(tvb);
if (bytes_to_copy > 128)
bytes_to_copy = 128;
tvb_memcpy(tvb, (guint8 *)&temp[i], 0,
bytes_to_copy);
temp[i + bytes_to_copy] = '\0';
}
}
}
col_add_str(pinfo->cinfo, COL_INFO, temp);
}
rlogin_state_machine( hash_info, tvb, pinfo);
if ( tree) /* if proto tree, decode data */
rlogin_display( hash_info, tvb, pinfo, tree, tcpinfo);
}
void
proto_register_rlogin( void){
/* Prep the rlogin protocol, for now, just register it */
static gint *ett[] = {
&ett_rlogin,
&ett_rlogin_window,
&ett_rlogin_window_rows,
&ett_rlogin_window_cols,
&ett_rlogin_window_x_pixels,
&ett_rlogin_window_y_pixels,
&ett_rlogin_user_info
};
static hf_register_info hf[] = {
{ &hf_user_info,
{ "User Info", "rlogin.user_info", FT_NONE, BASE_NONE,
NULL, 0x0, "", HFILL
}
},
{ &hf_window_info,
{ "Window Info", "rlogin.window_size", FT_NONE, BASE_NONE,
NULL, 0x0, "", HFILL
}
},
{ &hf_window_info_rows,
{ "Rows", "rlogin.window_size.rows", FT_UINT16, BASE_DEC,
NULL, 0x0, "", HFILL
}
},
{ &hf_window_info_cols,
{ "Columns", "rlogin.window_size.cols", FT_UINT16, BASE_DEC,
NULL, 0x0, "", HFILL
}
},
{ &hf_window_info_x_pixels,
{ "X Pixels", "rlogin.window_size.x_pixels", FT_UINT16, BASE_DEC,
NULL, 0x0, "", HFILL
}
},
{ &hf_window_info_y_pixels,
{ "Y Pixels", "rlogin.window_size.y_pixels", FT_UINT16, BASE_DEC,
NULL, 0x0, "", HFILL
}
}
};
proto_rlogin = proto_register_protocol (
"Rlogin Protocol", "Rlogin", "rlogin");
proto_register_field_array(proto_rlogin, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
register_init_routine( &rlogin_init); /* register re-init routine */
}
void
proto_reg_handoff_rlogin(void) {
/* dissector install routine */
dissector_handle_t rlogin_handle;
rlogin_handle = create_dissector_handle(dissect_rlogin, proto_rlogin);
dissector_add("tcp.port", TCP_PORT_RLOGIN, rlogin_handle);
}
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