osmith
/
wireshark
forked from osmocom/wireshark
1
0
Fork 0
Code Pull Requests Releases Wiki Activity
wireshark/packet-tftp.c

288 lines
8.2 KiB
C
Raw Blame History

/* packet-tftp.c
* Routines for tftp packet dissection
*
* Richard Sharpe <rsharpe@ns.aus.com>
* Craig Newell <CraigN@cheque.uq.edu.au>
* RFC2347 TFTP Option Extension
*
* $Id: packet-tftp.c,v 1.26 2001/06/18 02:17:53 guy Exp $
*
* Ethereal - Network traffic analyzer
* By Gerald Combs <gerald@ethereal.com>
* Copyright 1998 Gerald Combs
*
* Copied from packet-bootp.c
*
* 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
#ifdef HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif
#ifdef HAVE_NETINET_IN_H
# include <netinet/in.h>
#endif
#include <glib.h>
#include "packet.h"
#include "conversation.h"
static int proto_tftp = -1;
static int hf_tftp_opcode = -1;
static int hf_tftp_source_file = -1;
static int hf_tftp_destination_file = -1;
static int hf_tftp_transfer_type = -1;
static int hf_tftp_blocknum = -1;
static int hf_tftp_error_code = -1;
static int hf_tftp_error_string = -1;
static gint ett_tftp = -1;
#define UDP_PORT_TFTP 69
#define TFTP_RRQ 1
#define TFTP_WRQ 2
#define TFTP_DATA 3
#define TFTP_ACK 4
#define TFTP_ERROR 5
#define TFTP_OACK 6
static const value_string tftp_opcode_vals[] = {
{ TFTP_RRQ, "Read Request" },
{ TFTP_WRQ, "Write Request" },
{ TFTP_DATA, "Data Packet" },
{ TFTP_ACK, "Acknowledgement" },
{ TFTP_ERROR, "Error Code" },
{ TFTP_OACK, "Option Acknowledgement" },
{ 0, NULL }
};
static const value_string tftp_error_code_vals[] = {
{ 0, "Not defined" },
{ 1, "File not found" },
{ 2, "Access violation" },
{ 3, "Disk full or allocation exceeded" },
{ 4, "Illegal TFTP Operation" },
{ 5, "Unknown transfer ID" },
{ 6, "File already exists" },
{ 7, "No such user" },
{ 0, NULL }
};
static void tftp_dissect_options(tvbuff_t *tvb, int offset, proto_tree *tree);
static void
dissect_tftp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
proto_tree *tftp_tree;
proto_item *ti;
conversation_t *conversation;
gint offset = 0;
guint16 opcode;
u_int i1;
CHECK_DISPLAY_AS_DATA(proto_tftp, tvb, pinfo, tree);
pinfo->current_proto = "TFTP";
/*
* The first TFTP packet goes to the TFTP port; the second one
* comes from some *other* port, but goes back to the same
* IP address and port as the ones from which the first packet
* came; all subsequent packets go between those two IP addresses
* and ports.
*
* If this packet went to the TFTP port, we check to see if
* there's already a conversation with one address/port pair
* matching the source IP address and port of this packet,
* the other address matching the destination IP address of this
* packet, and any destination port.
*
* If not, we create one, with its address 1/port 1 pair being
* the source address/port of this packet, its address 2 being
* the destination address of this packet, and its port 2 being
* wildcarded, and give it the TFTP dissector as a dissector.
*/
if (pinfo->destport == UDP_PORT_TFTP) {
conversation = find_conversation(&pinfo->src, &pinfo->dst, PT_UDP,
pinfo->srcport, 0, NO_PORT_B);
if (conversation == NULL) {
conversation = conversation_new(&pinfo->src, &pinfo->dst, PT_UDP,
pinfo->srcport, 0, NULL,
NO_PORT2);
conversation_set_dissector(conversation, dissect_tftp);
}
}
if (check_col(pinfo->fd, COL_PROTOCOL))
col_set_str(pinfo->fd, COL_PROTOCOL, "TFTP");
opcode = tvb_get_ntohs(tvb, offset);
if (check_col(pinfo->fd, COL_INFO)) {
col_add_fstr(pinfo->fd, COL_INFO, "TFTP %s",
val_to_str(opcode, tftp_opcode_vals, "Unknown (0x%04x)"));
}
if (tree) {
ti = proto_tree_add_item(tree, proto_tftp, tvb, offset,
tvb_length_remaining(tvb, offset), FALSE);
tftp_tree = proto_item_add_subtree(ti, ett_tftp);
proto_tree_add_uint(tftp_tree, hf_tftp_opcode, tvb,
offset, 2, opcode);
offset += 2;
switch (opcode) {
case TFTP_RRQ:
i1 = tvb_strsize(tvb, offset);
proto_tree_add_item(tftp_tree, hf_tftp_source_file,
tvb, offset, i1, FALSE);
offset += i1;
i1 = tvb_strsize(tvb, offset);
ti = proto_tree_add_item(tftp_tree, hf_tftp_transfer_type,
tvb, offset, i1, FALSE);
offset += i1;
tftp_dissect_options(tvb, offset, tftp_tree);
break;
case TFTP_WRQ:
i1 = tvb_strsize(tvb, offset);
proto_tree_add_item(tftp_tree, hf_tftp_destination_file,
tvb, offset, i1, FALSE);
offset += i1;
i1 = tvb_strsize(tvb, offset);
ti = proto_tree_add_item(tftp_tree, hf_tftp_transfer_type,
tvb, offset, i1, FALSE);
offset += i1;
tftp_dissect_options(tvb, offset, tftp_tree);
break;
case TFTP_DATA:
proto_tree_add_item(tftp_tree, hf_tftp_blocknum, tvb, offset, 2,
FALSE);
offset += 2;
proto_tree_add_text(tftp_tree, tvb, offset, tvb_length_remaining(tvb, offset),
"Data (%d bytes)", tvb_length_remaining(tvb, offset));
break;
case TFTP_ACK:
proto_tree_add_item(tftp_tree, hf_tftp_blocknum, tvb, offset, 2,
FALSE);
break;
case TFTP_ERROR:
proto_tree_add_item(tftp_tree, hf_tftp_error_code, tvb, offset, 2,
FALSE);
offset += 2;
i1 = tvb_strsize(tvb, offset);
proto_tree_add_item(tftp_tree, hf_tftp_error_string, tvb, offset,
i1, FALSE);
break;
case TFTP_OACK:
tftp_dissect_options(tvb, offset, tftp_tree);
break;
default:
proto_tree_add_text(tftp_tree, tvb, offset, tvb_length_remaining(tvb, offset),
"Data (%d bytes)", tvb_length_remaining(tvb, offset));
break;
}
}
}
static void
tftp_dissect_options(tvbuff_t *tvb, int offset, proto_tree *tree)
{
int option_len, value_len;
int value_offset;
while (tvb_offset_exists(tvb, offset)) {
option_len = tvb_strsize(tvb, offset); /* length of option */
value_offset = offset + option_len;
value_len = tvb_strsize(tvb, value_offset); /* length of value */
proto_tree_add_text(tree, tvb, offset, option_len+value_len,
"Option: %s = %s",
tvb_get_ptr(tvb, offset, option_len),
tvb_get_ptr(tvb, value_offset, value_len));
offset += option_len + value_len;
}
}
void
proto_register_tftp(void)
{
static hf_register_info hf[] = {
{ &hf_tftp_opcode,
{ "Opcode", "tftp.opcode",
FT_UINT16, BASE_DEC, VALS(tftp_opcode_vals), 0x0,
"TFTP message type", HFILL }},
{ &hf_tftp_source_file,
{ "Source File", "tftp.source_file",
FT_STRINGZ, BASE_DEC, NULL, 0x0,
"TFTP source file name", HFILL }},
{ &hf_tftp_destination_file,
{ "DESTINATION File", "tftp.destination_file",
FT_STRINGZ, BASE_DEC, NULL, 0x0,
"TFTP source file name", HFILL }},
{ &hf_tftp_transfer_type,
{ "Type", "tftp.type",
FT_STRINGZ, BASE_DEC, NULL, 0x0,
"TFTP transfer type", HFILL }},
{ &hf_tftp_blocknum,
{ "Block", "tftp.block",
FT_UINT16, BASE_DEC, NULL, 0x0,
"Block number", HFILL }},
{ &hf_tftp_error_code,
{ "Error code", "tftp.error.code",
FT_UINT16, BASE_DEC, VALS(tftp_error_code_vals), 0x0,
"Error code in case of TFTP error message", HFILL }},
{ &hf_tftp_error_string,
{ "Error message", "tftp.error.message",
FT_STRINGZ, BASE_DEC, NULL, 0x0,
"Error string in case of TFTP error message", HFILL }}
};
static gint *ett[] = {
&ett_tftp,
};
proto_tftp = proto_register_protocol("Trivial File Transfer Protocol",
"TFTP", "tftp");
proto_register_field_array(proto_tftp, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
}
void
proto_reg_handoff_tftp(void)
{
dissector_add("udp.port", UDP_PORT_TFTP, dissect_tftp, proto_tftp);
}
View Git Blame Copy Permalink