![Guy Harris](/assets/img/avatar_default.png)
statements. Move the setting of the Protocol column in various dissectors before anything is fetched from the packet, and also clear the Info column at that point in those and some other dissectors, so that if an exception is thrown, the columns don't reflect the previous protocol. Don't use col_add_fstr(..., "%s", string); Use col_add_str(..., string); as it does the same thing, but doesn't drag all the heavy *printf machinery in. Fix the DDTP dissector to set the Info column regardless of whether we're building a protocol tree or not, and to set it to "Encrypted payload" if the payload is encrypted. Also fix a typo in a field name. Register the FTP data dissector as being associated with the FTP data protocol, not the FTP protocol (the removed "CHECK_DISPLAY_AS_DATA()" call checked "proto_ftp_data", and the removed "pinfo->current_proto =" line set it to "FTP-DATA", so it should be associated with "proto_ftp_data"). Make the H1 dissector check whether the frame has at least 2 bytes in it before checking the first two bytes; heuristic dissectors must not throw exceptions until they've accepted the packet as one of theirs. Use "tvb_format_text()" rather than "tvb_get_ptr()" and "format_text()" in some dissectors where the result of "tvb_get_ptr()" is used only in the "format_text()" call. In the Quake dissector, don't check whether there are at least 4 bytes in the packet - if we return, the packet won't be dissected at all (it's not as if some other dissector will get to handle it), and, if we don't return, we'll throw an exception if there aren't at least 4 bytes in the packet, so the packet will be marked as short or malformed, as appropriate. In the RIPng dissector, associate the table of strings for the command field with the command field, so that the dissector doesn't have to format the string for the protocol tree entry itself, and so that the filter construction dialog box can let you select "Request" or "Response" from a list rather than requiring you to know the values for "Request" and "Response". Make "dissect_rpc()" static, as it's called only through a heuristic dissector list. Use "col_set_str()" to set the COL_PROTOCOL column for RPC protocols; the string used is from a table provided by the dissector, and is a string constant. Don't format the Info column for WSP into a buffer and then format that buffer into the column with "%s" - "col_add_fstr()" can do the formatting for you, without having to allocate your own buffer (or run through the *printf machinery twice). Don't fetch fields from the WTP packet until you're ready to use them, so that you don't throw an exception before you even set the Protocol column or clear the Info column. Use "pinfo->destport", not "pi.destport", in the Zebra dissector when checking whether the packet is a request or reply, and do the check by comparing with "pinfo->match_port" rather than TCP_PORT_ZEBRA (so that if the dissector is ever registered on another port, it still correctly determines whether the packet is a request or reply - the Network Monitor HTTP dissector has port 80 wired into its brain, which is a bit irritating if you're trying to get it to dissect HTTP proxy traffic on port 3128 or proxy administration UI traffic on port 3132). svn path=/trunk/; revision=2931
500 lines
13 KiB
C
500 lines
13 KiB
C
/* packet-rlogin.c
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* Routines for unix rlogin packet dissection
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* Copyright 2000, Jeffrey C. Foster <jfoste@woodward.com>
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*
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* $Id: packet-rlogin.c,v 1.14 2001/01/22 08:03:45 guy Exp $
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*
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* Ethereal - Network traffic analyzer
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* By Gerald Combs <gerald@zing.org>
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* Copyright 1998 Gerald Combs
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*
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*
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* Based upon RFC-1282 - BSD Rlogin
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*
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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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*
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*
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*/
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#ifdef HAVE_CONFIG_H
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# include "config.h"
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#endif
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#ifdef HAVE_SYS_TYPES_H
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# include <sys/types.h>
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#endif
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#ifdef HAVE_NETINET_IN_H
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# include <netinet/in.h>
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#endif
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#include <stdio.h>
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#include <string.h>
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#include <glib.h>
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#ifdef NEED_SNPRINTF_H
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# include "snprintf.h"
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#endif
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#include "packet.h"
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#include "resolv.h"
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#include "globals.h"
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#include "alignment.h"
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#include "conversation.h"
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#include "packet-tcp.h"
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#define CHECK_PACKET_LENGTH(X) if (!BYTES_ARE_IN_FRAME(offset, X)){ \
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proto_tree_add_text(tree, NullTVB, offset, 0, "*** FRAME TOO SHORT ***"); \
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return; }
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#define TCP_PORT_RLOGIN 513
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static int proto_rlogin = -1;
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static int ett_rlogin = -1;
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static int ett_rlogin_window = -1;
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static int ett_rlogin_user_info = -1;
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static int ett_rlogin_window_rows = -1;
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static int ett_rlogin_window_cols = -1;
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static int ett_rlogin_window_x_pixels = -1;
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static int ett_rlogin_window_y_pixels = -1;
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static int hf_user_info = -1;
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static int hf_window_info = -1;
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static int hf_window_info_rows = -1;
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static int hf_window_info_cols = -1;
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static int hf_window_info_x_pixels = -1;
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static int hf_window_info_y_pixels = -1;
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#define RLOGIN_PORT 513
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#define NAME_LEN 32
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typedef struct {
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int state;
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int info_framenum;
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char name[ NAME_LEN];
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}rlogin_hash_entry_t;
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#define NONE 0
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#define USER_INFO_WAIT 1
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#define DONE 2
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#define BAD 2
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static GMemChunk *rlogin_vals = NULL;
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#define rlogin_hash_init_count 20
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static guint32 last_abs_sec = 0;
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static guint32 last_abs_usec= 0;
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/* Find the length of a '\0'-terminated string, *INCLUDING* the terminating
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'\0', but don't run past the end of the packet doing so. */
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static int
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string_len(const char *str, int maxlen)
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{
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const char *str_end;
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str_end = memchr(str, '\0', maxlen);
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if (str_end == NULL) {
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/* No '\0' found - return the length as of when we stopped,
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plus one to force the length to be too long and and
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CHECK_PACKET_LENGTH to fail. */
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return maxlen + 1;
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}
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return str_end - str + 1;
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}
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static void
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rlogin_init( void){
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/* Routine to initialize rlogin protocol before each capture or filter pass. */
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/* Release any memory if needed. Then setup the memory chunks. */
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last_abs_sec = 0;
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last_abs_usec= 0;
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if (rlogin_vals)
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g_mem_chunk_destroy(rlogin_vals);
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rlogin_vals = g_mem_chunk_new("rlogin_vals",
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sizeof( rlogin_hash_entry_t),
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rlogin_hash_init_count * sizeof( rlogin_hash_entry_t),
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G_ALLOC_AND_FREE);
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}
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/**************** Decoder State Machine ******************/
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static void
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rlogin_state_machine( rlogin_hash_entry_t *hash_info, const u_char *pd,
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int offset, frame_data *fd) {
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/* rlogin stream decoder */
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/* Just watched for second packet from client with the user name and */
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/* terminal type information. */
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if ( pi.destport != RLOGIN_PORT) /* not from client */
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return;
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/* exit if not needed */
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if (( hash_info->state == DONE) || ( hash_info->state == BAD))
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return;
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/* test timestamp */
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if (( last_abs_sec > fd->abs_secs) ||
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(( last_abs_sec == fd->abs_secs) && ( last_abs_usec >= fd->abs_usecs)))
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return;
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last_abs_sec = fd->abs_secs; /* save timestamp */
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last_abs_usec = fd->abs_usecs;
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if ( !IS_DATA_IN_FRAME(offset)) /* exit if no data */
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return;
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if ( hash_info->state == NONE){ /* new connection*/
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if ( GBYTE( pd, offset + 1)) { /* expect a NULL */
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hash_info->state = DONE; /* quit, no NULL */
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return;
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}
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else {
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if (( END_OF_FRAME) <= 1) /* if no data */
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hash_info->state = USER_INFO_WAIT;
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else {
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hash_info->state = DONE;
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hash_info->info_framenum = fd->num;
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}
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}
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} /* expect user data here */
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/*$$$ may need to do more checking here */
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else if ( hash_info->state == USER_INFO_WAIT) {
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hash_info->state = DONE;
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hash_info->info_framenum = fd->num;
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/* save name for later*/
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strncpy( hash_info->name, &pd[ offset], NAME_LEN);
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hash_info->name[ NAME_LEN] = 0;
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if (check_col(fd, COL_INFO)) /* update summary */
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col_append_str( fd, COL_INFO, ", User information");
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}
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}
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static void rlogin_display( rlogin_hash_entry_t *hash_info, const u_char *pd,
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int offset, frame_data *fd, proto_tree *tree) {
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/* Display the proto tree */
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proto_tree *rlogin_tree, *user_info_tree, *window_tree;
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proto_item *ti;
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guint8 *Ptr;
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const char *str;
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int str_len;
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proto_item *user_info_item, *window_info_item;
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ti = proto_tree_add_item( tree, proto_rlogin, NullTVB, offset,
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END_OF_FRAME, FALSE);
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rlogin_tree = proto_item_add_subtree(ti, ett_rlogin);
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if ( !IS_DATA_IN_FRAME(offset)) /* exit if no data */
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return;
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if ( tcp_urgent_pointer && /* if control message */
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BYTES_ARE_IN_FRAME(offset + tcp_urgent_pointer - 1, 1)) {
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int i = offset + tcp_urgent_pointer - 1;
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guint16 Temp = GBYTE( pd, i);
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if ( i < offset) /* check for data in front */
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proto_tree_add_text( rlogin_tree, NullTVB, offset, i - offset,
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"Data");
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proto_tree_add_text( rlogin_tree, NullTVB, i, 1, "Control byte: %u (%s)",
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Temp,
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(Temp == 2) ? "Clear buffer" :
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(Temp == 0x10) ? "Raw mode" :
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(Temp == 0x20) ? "Cooked mode" :
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(Temp == 0x80) ? "Window size request" :
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"Unknown");
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offset = i; /* adjust offset */
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}
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else if ( !GBYTE( pd, offset)){ /* startup */
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if ( pi.srcport== RLOGIN_PORT) /* from server */
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proto_tree_add_text(rlogin_tree, NullTVB, offset, 1,
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"Startup info received flag (0x00)");
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else
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proto_tree_add_text(rlogin_tree, NullTVB, offset, 1,
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"Client Startup Flag (0x00)");
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++offset;
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}
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if (!IS_DATA_IN_FRAME(offset))
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return; /* No more data to check */
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if ( hash_info->info_framenum == fd->num){ /* user info ?*/
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user_info_item = proto_tree_add_item( rlogin_tree, hf_user_info, NullTVB,
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offset, END_OF_FRAME, FALSE);
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str = &pd[ offset]; /* do server user name */
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str_len = string_len( str, END_OF_FRAME);
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CHECK_PACKET_LENGTH( str_len);
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user_info_tree = proto_item_add_subtree( user_info_item,
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ett_rlogin_user_info);
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proto_tree_add_text( user_info_tree, NullTVB, offset, str_len,
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"Server User Name: %.*s", str_len, str);
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offset += str_len;
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if (!IS_DATA_IN_FRAME(offset))
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return; /* No more data to check */
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str = &pd[ offset]; /* do client user name */
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str_len = string_len( str, END_OF_FRAME);
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CHECK_PACKET_LENGTH( str_len);
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proto_tree_add_text( user_info_tree, NullTVB, offset, str_len,
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"Client User Name: %.*s", str_len, str);
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offset += str_len;
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if (!IS_DATA_IN_FRAME(offset))
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return; /* No more data to check */
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str = &pd[ offset]; /* do terminal type/speed */
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str_len = string_len( str, END_OF_FRAME);
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CHECK_PACKET_LENGTH( str_len);
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proto_tree_add_text( user_info_tree, NullTVB, offset, str_len,
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"Terminal Type/Speed: %.*s", str_len, str);
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offset += str_len;
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}
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if (!IS_DATA_IN_FRAME(offset))
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return; /* No more data to check */
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/* test for terminal information, the data will have 2 0xff bytes */
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/* look for first 0xff byte */
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Ptr = (guint8*)memchr( &pd[ offset], 0xff, END_OF_FRAME);
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if (( Ptr) && (*(Ptr + 1) == 0xff)) { /* found terminal info */
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int ti_offset = Ptr - pd; /* get offset */
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if ( ti_offset < offset){ /*if data before terminal info*/
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proto_tree_add_text( rlogin_tree, NullTVB, offset,
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(ti_offset - offset), "Data");
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offset = ti_offset;
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}
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CHECK_PACKET_LENGTH( 12);
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window_info_item = proto_tree_add_item( rlogin_tree,
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hf_window_info, NullTVB, offset, 12, FALSE );
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window_tree = proto_item_add_subtree( window_info_item,
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ett_rlogin_window);
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CHECK_PACKET_LENGTH( 2);
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proto_tree_add_text( window_tree, NullTVB, offset, 2,
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"Magic Cookie: (0xff, 0xff)");
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offset += 2;
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CHECK_PACKET_LENGTH( 2);
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proto_tree_add_text( window_tree, NullTVB, offset, 2,
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"Window size marker: 'ss'");
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offset += 2;
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CHECK_PACKET_LENGTH( 2);
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proto_tree_add_uint( window_tree, hf_window_info_rows, NullTVB, offset,
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2, pntohs( &pd[offset]));
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offset += 2;
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CHECK_PACKET_LENGTH( 2);
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proto_tree_add_uint( window_tree, hf_window_info_cols, NullTVB, offset,
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2, pntohs( &pd[offset]) );
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offset += 2;
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CHECK_PACKET_LENGTH( 2);
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proto_tree_add_uint( window_tree, hf_window_info_x_pixels, NullTVB,
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offset, 2, pntohs( &pd[offset]));
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offset += 2;
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CHECK_PACKET_LENGTH( 2);
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proto_tree_add_uint( window_tree, hf_window_info_y_pixels, NullTVB,
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offset, 2, pntohs( &pd[offset]) );
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offset += 2;
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}
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if ( END_OF_FRAME != 0) /* if more data */
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proto_tree_add_text(rlogin_tree, NullTVB, offset, END_OF_FRAME, "Data");
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}
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static void
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dissect_rlogin(const u_char *pd, int offset, frame_data *fd, proto_tree *tree) {
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guint8 *Ptr;
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rlogin_hash_entry_t *hash_info = 0;
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conversation_t *conversation;
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/* Lookup this connection*/
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conversation = find_conversation( &pi.src, &pi.dst, pi.ptype,
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pi.srcport, pi.destport, 0);
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if ( conversation) /* conversation found */
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hash_info = conversation->data;
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/* new conversation create local data structure */
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else {
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hash_info = g_mem_chunk_alloc(rlogin_vals);
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hash_info->state = NONE;
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hash_info->info_framenum = -1;
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hash_info->name[ 0] = 0;
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conversation_new( &pi.src, &pi.dst, pi.ptype,
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pi.srcport, pi.destport, hash_info, 0);
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}
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if (check_col(fd, COL_PROTOCOL)) /* update protocol */
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col_set_str(fd, COL_PROTOCOL, "Rlogin");
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if (check_col(fd, COL_INFO)){ /* display packet info*/
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char temp[1000];
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col_clear(fd, COL_INFO);
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if ( hash_info->name[0]) {
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strcpy( temp, "User name: ");
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strcat( temp, hash_info->name);
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strcat( temp, ", ");
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}
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else
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temp[0] = 0;
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if ( !GBYTE(pd, offset))
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strcat( temp, "Start Handshake");
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else if ( tcp_urgent_pointer)
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strcat( temp, "Control Message");
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else { /* check for terminal info */
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Ptr = (guint8*)memchr( &pd[ offset], 0xff, END_OF_FRAME);
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if (( Ptr) && (*(Ptr + 1) == 0xff))
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strcat( temp, "Terminal Info");
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else {
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int i;
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strcat( temp, "Data:");
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i = strlen( temp);
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strncat( temp, &pd[ offset], 128);
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temp[ i + MIN( 128, END_OF_FRAME)] = 0;
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}
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}
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col_add_str(fd, COL_INFO, temp);
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}
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rlogin_state_machine( hash_info, pd, offset, fd);
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if ( tree) /* if proto tree, decode data */
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rlogin_display( hash_info, pd, offset, fd, tree);
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}
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void
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proto_register_rlogin( void){
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/* Prep the rlogin protocol, for now, just register it */
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static gint *ett[] = {
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&ett_rlogin,
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&ett_rlogin_window,
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&ett_rlogin_window_rows,
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&ett_rlogin_window_cols,
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&ett_rlogin_window_x_pixels,
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&ett_rlogin_window_y_pixels,
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&ett_rlogin_user_info
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};
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static hf_register_info hf[] = {
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{ &hf_user_info,
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{ "User Info", "rlogin.user_info", FT_NONE, BASE_NONE,
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NULL, 0x0, ""
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}
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},
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{ &hf_window_info,
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{ "Window Info", "rlogin.window_size", FT_NONE, BASE_NONE,
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NULL, 0x0, ""
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}
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},
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{ &hf_window_info_rows,
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{ "Rows", "rlogin.window_size.rows", FT_UINT16, BASE_DEC,
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NULL, 0x0, ""
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}
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},
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{ &hf_window_info_cols,
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{ "Columns", "rlogin.window_size.cols", FT_UINT16, BASE_DEC,
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NULL, 0x0, ""
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}
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},
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{ &hf_window_info_x_pixels,
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{ "X Pixels", "rlogin.window_size.x_pixels", FT_UINT16, BASE_DEC,
|
|
NULL, 0x0, ""
|
|
}
|
|
},
|
|
{ &hf_window_info_y_pixels,
|
|
{ "Y Pixels", "rlogin.window_size.y_pixels", FT_UINT16, BASE_DEC,
|
|
NULL, 0x0, ""
|
|
}
|
|
}
|
|
};
|
|
|
|
|
|
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 */
|
|
|
|
old_dissector_add("tcp.port", TCP_PORT_RLOGIN, dissect_rlogin,
|
|
proto_rlogin);
|
|
}
|