forked from osmocom/wireshark
![Guy Harris](/assets/img/avatar_default.png)
Cast away some implicit 64-bit-to-32-bit conversion errors due to use of sizeof. Cast away some implicit 64-bit-to-32-bit conversion errors due to use of strtol() and strtoul(). Change some data types to avoid those implicit conversion warnings. When assigning a constant to a float, make sure the constant isn't a double, by appending "f" to the constant. Constify a bunch of variables, parameters, and return values to eliminate warnings due to strings being given const qualifiers. Cast away those warnings in some cases where an API we don't control forces us to do so. Enable a bunch of additional warnings by default. Note why at least some of the other warnings aren't enabled. randpkt.c and text2pcap.c are used to build programs, so they don't need to be in EXTRA_DIST. If the user specifies --enable-warnings-as-errors, add -Werror *even if the user specified --enable-extra-gcc-flags; assume they know what they're doing and are willing to have the compile fail due to the extra GCC warnings being treated as errors. svn path=/trunk/; revision=46748
541 lines
16 KiB
C
541 lines
16 KiB
C
/* packet-tftp.c
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* Routines for tftp packet dissection
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*
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* Richard Sharpe <rsharpe@ns.aus.com>
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* Craig Newell <CraigN@cheque.uq.edu.au>
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* RFC2347 TFTP Option Extension
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* Joerg Mayer (see AUTHORS file)
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* RFC2348 TFTP Blocksize Option
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*
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* $Id$
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*
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* Wireshark - Network traffic analyzer
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* By Gerald Combs <gerald@wireshark.org>
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* Copyright 1998 Gerald Combs
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*
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* Copied from packet-bootp.c
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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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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/* Documentation:
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* RFC 1350: THE TFTP PROTOCOL (REVISION 2)
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* RFC 2090: TFTP Multicast Option
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* (not yet implemented)
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* RFC 2347: TFTP Option Extension
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* RFC 2348: TFTP Blocksize Option
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* RFC 2349: TFTP Timeout Interval and Transfer Size Options
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* (not yet implemented)
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*/
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#include "config.h"
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#include <glib.h>
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#include <stdlib.h>
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#include <epan/packet.h>
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#include <epan/conversation.h>
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#include <epan/emem.h>
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#include <epan/expert.h>
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#include <epan/range.h>
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#include <epan/prefs.h>
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/* Things we may want to remember for a whole conversation */
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typedef struct _tftp_conv_info_t {
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guint16 blocksize;
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gchar *source_file, *destination_file;
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} tftp_conv_info_t;
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static int proto_tftp = -1;
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static int hf_tftp_opcode = -1;
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static int hf_tftp_source_file = -1;
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static int hf_tftp_destination_file = -1;
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static int hf_tftp_transfer_type = -1;
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static int hf_tftp_blocknum = -1;
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static int hf_tftp_error_code = -1;
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static int hf_tftp_error_string = -1;
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static int hf_tftp_option_name = -1;
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static int hf_tftp_option_value = -1;
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static gint ett_tftp = -1;
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static gint ett_tftp_option = -1;
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static dissector_handle_t tftp_handle;
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static dissector_handle_t data_handle;
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#define UDP_PORT_TFTP_RANGE "69"
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void proto_reg_handoff_tftp (void);
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/* User definable values */
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static range_t *global_tftp_port_range;
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#define TFTP_RRQ 1
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#define TFTP_WRQ 2
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#define TFTP_DATA 3
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#define TFTP_ACK 4
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#define TFTP_ERROR 5
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#define TFTP_OACK 6
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#define TFTP_INFO 255
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static const value_string tftp_opcode_vals[] = {
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{ TFTP_RRQ, "Read Request" },
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{ TFTP_WRQ, "Write Request" },
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{ TFTP_DATA, "Data Packet" },
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{ TFTP_ACK, "Acknowledgement" },
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{ TFTP_ERROR, "Error Code" },
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{ TFTP_OACK, "Option Acknowledgement" },
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{ TFTP_INFO, "Information (MSDP)" },
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{ 0, NULL }
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};
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static const value_string tftp_error_code_vals[] = {
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{ 0, "Not defined" },
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{ 1, "File not found" },
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{ 2, "Access violation" },
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{ 3, "Disk full or allocation exceeded" },
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{ 4, "Illegal TFTP Operation" },
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{ 5, "Unknown transfer ID" }, /* Does not cause termination */
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{ 6, "File already exists" },
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{ 7, "No such user" },
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{ 8, "Option negotiation failed" },
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{ 0, NULL }
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};
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static void
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tftp_dissect_options(tvbuff_t *tvb, packet_info *pinfo, int offset,
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proto_tree *tree, guint16 opcode, tftp_conv_info_t *tftp_info)
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{
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int option_len, value_len;
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int value_offset;
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const char *optionname;
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const char *optionvalue;
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proto_item *opt_item;
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proto_tree *opt_tree;
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while (tvb_offset_exists(tvb, offset)) {
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option_len = tvb_strsize(tvb, offset); /* length of option */
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value_offset = offset + option_len;
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value_len = tvb_strsize(tvb, value_offset); /* length of value */
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optionname = tvb_format_text(tvb, offset, option_len);
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optionvalue = tvb_format_text(tvb, value_offset, value_len);
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opt_item = proto_tree_add_text(tree, tvb, offset, option_len+value_len,
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"Option: %s = %s", optionname, optionvalue);
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opt_tree = proto_item_add_subtree(opt_item, ett_tftp_option);
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proto_tree_add_item(opt_tree, hf_tftp_option_name, tvb, offset,
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option_len, ENC_ASCII|ENC_NA);
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proto_tree_add_item(opt_tree, hf_tftp_option_value, tvb, value_offset,
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value_len, ENC_ASCII|ENC_NA);
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offset += option_len + value_len;
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col_append_fstr(pinfo->cinfo, COL_INFO, ", %s=%s",
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optionname, optionvalue);
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/* Special code to handle individual options */
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if (!g_ascii_strcasecmp((const char *)optionname, "blksize") &&
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opcode == TFTP_OACK) {
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gint blocksize = (gint)strtol((const char *)optionvalue, NULL, 10);
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if (blocksize < 8 || blocksize > 65464) {
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expert_add_info_format(pinfo, NULL, PI_RESPONSE_CODE,
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PI_WARN, "TFTP blocksize out of range");
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} else {
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tftp_info->blocksize = blocksize;
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}
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}
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}
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}
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static void dissect_tftp_message(tftp_conv_info_t *tftp_info,
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tvbuff_t *tvb, packet_info *pinfo,
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proto_tree *tree)
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{
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proto_tree *tftp_tree = NULL;
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proto_item *ti;
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gint offset = 0;
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guint16 opcode;
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guint16 bytes;
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guint16 blocknum;
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guint i1;
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guint16 error;
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col_set_str(pinfo->cinfo, COL_PROTOCOL, "TFTP");
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opcode = tvb_get_ntohs(tvb, offset);
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col_add_str(pinfo->cinfo, COL_INFO,
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val_to_str(opcode, tftp_opcode_vals, "Unknown (0x%04x)"));
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if (tree) {
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ti = proto_tree_add_item(tree, proto_tftp, tvb, offset, -1, ENC_NA);
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tftp_tree = proto_item_add_subtree(ti, ett_tftp);
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if (tftp_info->source_file) {
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ti = proto_tree_add_string(tftp_tree, hf_tftp_source_file, tvb,
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0, 0, tftp_info->source_file);
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PROTO_ITEM_SET_GENERATED(ti);
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}
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if (tftp_info->destination_file) {
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ti = proto_tree_add_string(tftp_tree, hf_tftp_destination_file, tvb,
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0, 0, tftp_info->destination_file);
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PROTO_ITEM_SET_GENERATED(ti);
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}
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proto_tree_add_uint(tftp_tree, hf_tftp_opcode, tvb,
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offset, 2, opcode);
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}
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offset += 2;
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switch (opcode) {
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case TFTP_RRQ:
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i1 = tvb_strsize(tvb, offset);
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proto_tree_add_item(tftp_tree, hf_tftp_source_file,
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tvb, offset, i1, ENC_ASCII|ENC_NA);
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tftp_info->source_file = tvb_get_seasonal_string(tvb, offset, i1);
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col_append_fstr(pinfo->cinfo, COL_INFO, ", File: %s",
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tvb_format_stringzpad(tvb, offset, i1));
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offset += i1;
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i1 = tvb_strsize(tvb, offset);
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proto_tree_add_item(tftp_tree, hf_tftp_transfer_type,
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tvb, offset, i1, ENC_ASCII|ENC_NA);
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col_append_fstr(pinfo->cinfo, COL_INFO, ", Transfer type: %s",
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tvb_format_stringzpad(tvb, offset, i1));
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offset += i1;
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tftp_dissect_options(tvb, pinfo, offset, tftp_tree,
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opcode, tftp_info);
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break;
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case TFTP_WRQ:
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i1 = tvb_strsize(tvb, offset);
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proto_tree_add_item(tftp_tree, hf_tftp_destination_file,
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tvb, offset, i1, ENC_ASCII|ENC_NA);
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tftp_info->destination_file =
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tvb_get_seasonal_string(tvb, offset, i1);
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col_append_fstr(pinfo->cinfo, COL_INFO, ", File: %s",
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tvb_format_stringzpad(tvb, offset, i1));
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offset += i1;
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i1 = tvb_strsize(tvb, offset);
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proto_tree_add_item(tftp_tree, hf_tftp_transfer_type,
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tvb, offset, i1, ENC_ASCII|ENC_NA);
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col_append_fstr(pinfo->cinfo, COL_INFO, ", Transfer type: %s",
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tvb_format_stringzpad(tvb, offset, i1));
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offset += i1;
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tftp_dissect_options(tvb, pinfo, offset, tftp_tree,
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opcode, tftp_info);
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break;
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case TFTP_INFO:
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tftp_dissect_options(tvb, pinfo, offset, tftp_tree,
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opcode, tftp_info);
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break;
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case TFTP_DATA:
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blocknum = tvb_get_ntohs(tvb, offset);
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proto_tree_add_uint(tftp_tree, hf_tftp_blocknum, tvb, offset, 2,
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blocknum);
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offset += 2;
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bytes = tvb_reported_length_remaining(tvb, offset);
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col_append_fstr(pinfo->cinfo, COL_INFO, ", Block: %i%s",
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blocknum,
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(bytes < tftp_info->blocksize)?" (last)":"" );
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if (bytes != 0) {
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tvbuff_t *data_tvb = tvb_new_subset(tvb, offset, -1, bytes);
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call_dissector(data_handle, data_tvb, pinfo, tree);
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}
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break;
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case TFTP_ACK:
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blocknum = tvb_get_ntohs(tvb, offset);
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proto_tree_add_uint(tftp_tree, hf_tftp_blocknum, tvb, offset, 2,
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blocknum);
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col_append_fstr(pinfo->cinfo, COL_INFO, ", Block: %i",
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blocknum);
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break;
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case TFTP_ERROR:
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error = tvb_get_ntohs(tvb, offset);
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proto_tree_add_uint(tftp_tree, hf_tftp_error_code, tvb, offset, 2,
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error);
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col_append_fstr(pinfo->cinfo, COL_INFO, ", Code: %s",
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val_to_str(error, tftp_error_code_vals, "Unknown (%u)"));
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offset += 2;
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i1 = tvb_strsize(tvb, offset);
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proto_tree_add_item(tftp_tree, hf_tftp_error_string, tvb, offset,
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i1, ENC_ASCII|ENC_NA);
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col_append_fstr(pinfo->cinfo, COL_INFO, ", Message: %s",
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tvb_format_stringzpad(tvb, offset, i1));
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expert_add_info_format(pinfo, NULL, PI_RESPONSE_CODE,
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PI_NOTE, "TFTP blocksize out of range");
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break;
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case TFTP_OACK:
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tftp_dissect_options(tvb, pinfo, offset, tftp_tree,
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opcode, tftp_info);
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break;
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default:
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proto_tree_add_text(tftp_tree, tvb, offset, -1,
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"Data (%d bytes)", tvb_reported_length_remaining(tvb, offset));
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break;
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}
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return;
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}
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static gboolean
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dissect_embeddedtftp_heur(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
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{
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/* Used to dissect TFTP packets where one can not assume
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that the TFTP is the only protocol used by that port, and
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that TFTP may not be carried by UDP */
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conversation_t *conversation = NULL;
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guint16 opcode;
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tftp_conv_info_t *tftp_info;
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conversation = find_or_create_conversation(pinfo);
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tftp_info = conversation_get_proto_data(conversation, proto_tftp);
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if (!tftp_info) {
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tftp_info = se_alloc(sizeof(tftp_conv_info_t));
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tftp_info->blocksize = 512; /* TFTP default block size */
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tftp_info->source_file = NULL;
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tftp_info->destination_file = NULL;
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conversation_add_proto_data(conversation, proto_tftp, tftp_info);
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}
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opcode = tvb_get_ntohs(tvb, 0);
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if ((opcode == TFTP_RRQ) ||
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(opcode == TFTP_WRQ) ||
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(opcode == TFTP_DATA) ||
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(opcode == TFTP_ACK) ||
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(opcode == TFTP_ERROR) ||
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(opcode == TFTP_INFO) ||
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(opcode == TFTP_OACK)) {
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dissect_tftp_message(tftp_info, tvb, pinfo, tree);
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return TRUE;
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}
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else {
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return FALSE;
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}
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}
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static void
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dissect_tftp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
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{
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conversation_t *conversation = NULL;
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tftp_conv_info_t *tftp_info;
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/*
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* The first TFTP packet goes to the TFTP port; the second one
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* comes from some *other* port, but goes back to the same
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* IP address and port as the ones from which the first packet
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* came; all subsequent packets go between those two IP addresses
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* and ports.
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*
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* If this packet went to the TFTP port, we check to see if
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* there's already a conversation with one address/port pair
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* matching the source IP address and port of this packet,
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* the other address matching the destination IP address of this
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* packet, and any destination port.
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*
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* If not, we create one, with its address 1/port 1 pair being
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* the source address/port of this packet, its address 2 being
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* the destination address of this packet, and its port 2 being
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* wildcarded, and give it the TFTP dissector as a dissector.
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*/
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if (value_is_in_range(global_tftp_port_range, pinfo->destport)) {
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conversation = find_conversation(pinfo->fd->num, &pinfo->src, &pinfo->dst, PT_UDP,
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pinfo->srcport, 0, NO_PORT_B);
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if( (conversation == NULL) || (conversation->dissector_handle != tftp_handle) ){
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conversation = conversation_new(pinfo->fd->num, &pinfo->src, &pinfo->dst, PT_UDP,
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pinfo->srcport, 0, NO_PORT2);
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conversation_set_dissector(conversation, tftp_handle);
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}
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} else {
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conversation = find_conversation(pinfo->fd->num, &pinfo->src, &pinfo->dst,
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pinfo->ptype, pinfo->srcport, pinfo->destport, 0);
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if( (conversation == NULL) || (conversation->dissector_handle != tftp_handle) ){
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conversation = conversation_new(pinfo->fd->num, &pinfo->src, &pinfo->dst, PT_UDP,
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pinfo->destport, pinfo->srcport, 0);
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conversation_set_dissector(conversation, tftp_handle);
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} else if (conversation->options & NO_PORT_B) {
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if (pinfo->destport == conversation->key_ptr->port1)
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conversation_set_port2(conversation, pinfo->srcport);
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else
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return;
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}
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}
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tftp_info = conversation_get_proto_data(conversation, proto_tftp);
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if (!tftp_info) {
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tftp_info = se_alloc(sizeof(tftp_conv_info_t));
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tftp_info->blocksize = 512; /* TFTP default block size */
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tftp_info->source_file = NULL;
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tftp_info->destination_file = NULL;
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conversation_add_proto_data(conversation, proto_tftp, tftp_info);
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}
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dissect_tftp_message(tftp_info, tvb, pinfo, tree);
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return;
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}
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|
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void
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proto_register_tftp(void)
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{
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static hf_register_info hf[] = {
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{ &hf_tftp_opcode,
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{ "Opcode", "tftp.opcode",
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FT_UINT16, BASE_DEC, VALS(tftp_opcode_vals), 0x0,
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"TFTP message type", HFILL }},
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{ &hf_tftp_source_file,
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{ "Source File", "tftp.source_file",
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FT_STRINGZ, BASE_NONE, NULL, 0x0,
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"TFTP source file name", HFILL }},
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{ &hf_tftp_destination_file,
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{ "DESTINATION File", "tftp.destination_file",
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FT_STRINGZ, BASE_NONE, NULL, 0x0,
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"TFTP source file name", HFILL }},
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{ &hf_tftp_transfer_type,
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{ "Type", "tftp.type",
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FT_STRINGZ, BASE_NONE, NULL, 0x0,
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"TFTP transfer type", HFILL }},
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{ &hf_tftp_blocknum,
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{ "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_NONE, NULL, 0x0,
|
|
"Error string in case of TFTP error message", HFILL }},
|
|
|
|
{ &hf_tftp_option_name,
|
|
{ "Option name", "tftp.option.name",
|
|
FT_STRINGZ, BASE_NONE, NULL, 0x0,
|
|
NULL, HFILL }},
|
|
|
|
{ &hf_tftp_option_value,
|
|
{ "Option value", "tftp.option.value",
|
|
FT_STRINGZ, BASE_NONE, NULL, 0x0,
|
|
NULL, HFILL }},
|
|
|
|
};
|
|
static gint *ett[] = {
|
|
&ett_tftp,
|
|
&ett_tftp_option,
|
|
};
|
|
|
|
module_t *tftp_module;
|
|
|
|
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));
|
|
|
|
register_dissector("tftp", dissect_tftp, proto_tftp);
|
|
|
|
/* Set default UDP ports */
|
|
range_convert_str(&global_tftp_port_range, UDP_PORT_TFTP_RANGE, MAX_UDP_PORT);
|
|
|
|
tftp_module = prefs_register_protocol(proto_tftp, proto_reg_handoff_tftp);
|
|
prefs_register_range_preference(tftp_module, "udp_ports",
|
|
"TFTP port numbers",
|
|
"Port numbers used for TFTP traffic "
|
|
"(default " UDP_PORT_TFTP_RANGE ")",
|
|
&global_tftp_port_range, MAX_UDP_PORT);
|
|
}
|
|
|
|
static void range_delete_callback (guint32 port)
|
|
{
|
|
dissector_delete_uint("udp.port", port, tftp_handle);
|
|
}
|
|
|
|
static void range_add_callback (guint32 port)
|
|
{
|
|
dissector_add_uint("udp.port", port, tftp_handle);
|
|
}
|
|
|
|
void
|
|
proto_reg_handoff_tftp(void)
|
|
{
|
|
static range_t *tftp_port_range;
|
|
static gboolean tftp_initialized = FALSE;
|
|
|
|
if (!tftp_initialized) {
|
|
tftp_handle = find_dissector("tftp");
|
|
data_handle = find_dissector("data");
|
|
heur_dissector_add("stun", dissect_embeddedtftp_heur, proto_tftp);
|
|
tftp_initialized = TRUE;
|
|
} else {
|
|
range_foreach(tftp_port_range, range_delete_callback);
|
|
g_free(tftp_port_range);
|
|
}
|
|
|
|
tftp_port_range = range_copy(global_tftp_port_range);
|
|
range_foreach(tftp_port_range, range_add_callback);
|
|
}
|
|
|
|
/*
|
|
* Editor modelines - http://www.wireshark.org/tools/modelines.html
|
|
*
|
|
* Local variables:
|
|
* c-basic-offset: 2
|
|
* tab-width: 8
|
|
* indent-tabs-mode: nil
|
|
* End:
|
|
*
|
|
* vi: set shiftwidth=2 tabstop=8 expandtab:
|
|
* :indentSize=2:tabSize=8:noTabs=true:
|
|
*/
|