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-rw-r--r--epan/dissectors/packet-tftp.c352
1 files changed, 352 insertions, 0 deletions
diff --git a/epan/dissectors/packet-tftp.c b/epan/dissectors/packet-tftp.c
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index 0000000000..879619b72f
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+++ b/epan/dissectors/packet-tftp.c
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+/* 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
+ *
+ * $Id$
+ *
+ * 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
+
+#include <glib.h>
+#include <epan/packet.h>
+#include <epan/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;
+
+static dissector_handle_t tftp_handle;
+
+#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" },
+ { 8, "Option negotiation failed" },
+ { 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 = NULL;
+ proto_item *ti;
+ conversation_t *conversation;
+ gint offset = 0;
+ guint16 opcode;
+ guint16 bytes;
+ guint16 blocknum;
+ guint i1;
+ guint16 error;
+
+ /*
+ * 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, NO_PORT2);
+ conversation_set_dissector(conversation, tftp_handle);
+ }
+ }
+
+ if (check_col(pinfo->cinfo, COL_PROTOCOL))
+ col_set_str(pinfo->cinfo, COL_PROTOCOL, "TFTP");
+
+ opcode = tvb_get_ntohs(tvb, offset);
+
+ if (check_col(pinfo->cinfo, COL_INFO)) {
+
+ col_add_fstr(pinfo->cinfo, COL_INFO, "%s",
+ val_to_str(opcode, tftp_opcode_vals, "Unknown (0x%04x)"));
+
+ }
+
+ if (tree) {
+
+ ti = proto_tree_add_item(tree, proto_tftp, tvb, offset, -1, 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);
+ if (tree) {
+ proto_tree_add_item(tftp_tree, hf_tftp_source_file,
+ tvb, offset, i1, FALSE);
+ }
+ if (check_col(pinfo->cinfo, COL_INFO)) {
+ col_append_fstr(pinfo->cinfo, COL_INFO, ", File: %s",
+ tvb_get_ptr(tvb, offset, i1));
+ }
+ offset += i1;
+
+ i1 = tvb_strsize(tvb, offset);
+ if (tree) {
+ ti = proto_tree_add_item(tftp_tree, hf_tftp_transfer_type,
+ tvb, offset, i1, FALSE);
+ }
+ if (check_col(pinfo->cinfo, COL_INFO)) {
+ col_append_fstr(pinfo->cinfo, COL_INFO, ", Transfer type: %s",
+ tvb_get_ptr(tvb, offset, i1));
+ }
+ offset += i1;
+
+ if (tree)
+ tftp_dissect_options(tvb, offset, tftp_tree);
+ break;
+
+ case TFTP_WRQ:
+ i1 = tvb_strsize(tvb, offset);
+ if (tree) {
+ proto_tree_add_item(tftp_tree, hf_tftp_destination_file,
+ tvb, offset, i1, FALSE);
+ }
+ if (check_col(pinfo->cinfo, COL_INFO)) {
+ col_append_fstr(pinfo->cinfo, COL_INFO, ", File: %s",
+ tvb_get_ptr(tvb, offset, i1));
+ }
+ offset += i1;
+
+ i1 = tvb_strsize(tvb, offset);
+ if (tree) {
+ ti = proto_tree_add_item(tftp_tree, hf_tftp_transfer_type,
+ tvb, offset, i1, FALSE);
+ }
+ if (check_col(pinfo->cinfo, COL_INFO)) {
+ col_append_fstr(pinfo->cinfo, COL_INFO, ", Transfer type: %s",
+ tvb_get_ptr(tvb, offset, i1));
+ }
+ offset += i1;
+
+ if (tree)
+ tftp_dissect_options(tvb, offset, tftp_tree);
+ break;
+
+ case TFTP_DATA:
+ blocknum = tvb_get_ntohs(tvb, offset);
+ if (tree) {
+ proto_tree_add_uint(tftp_tree, hf_tftp_blocknum, tvb, offset, 2,
+ blocknum);
+ }
+ offset += 2;
+
+ bytes = tvb_reported_length_remaining(tvb, offset);
+
+ if (check_col(pinfo->cinfo, COL_INFO)) {
+ col_append_fstr(pinfo->cinfo, COL_INFO, ", Block: %i%s",
+ blocknum,
+ (bytes < 512)?" (last)":"" );
+ }
+
+ if (bytes != 0) {
+ if (tree) {
+ proto_tree_add_text(tftp_tree, tvb, offset, -1,
+ "Data (%d bytes)", bytes);
+ }
+ }
+ break;
+
+ case TFTP_ACK:
+ blocknum = tvb_get_ntohs(tvb, offset);
+ if (tree) {
+ proto_tree_add_uint(tftp_tree, hf_tftp_blocknum, tvb, offset, 2,
+ blocknum);
+ }
+ if (check_col(pinfo->cinfo, COL_INFO)) {
+ col_append_fstr(pinfo->cinfo, COL_INFO, ", Block: %i",
+ blocknum);
+ }
+ break;
+
+ case TFTP_ERROR:
+ error = tvb_get_ntohs(tvb, offset);
+ if (tree) {
+ proto_tree_add_uint(tftp_tree, hf_tftp_error_code, tvb, offset, 2,
+ error);
+ }
+ if (check_col(pinfo->cinfo, COL_INFO)) {
+ col_append_fstr(pinfo->cinfo, COL_INFO, ", Code: %s",
+ val_to_str(error, tftp_error_code_vals, "Unknown (%u)"));
+ }
+ offset += 2;
+
+ i1 = tvb_strsize(tvb, offset);
+ if (tree) {
+ proto_tree_add_item(tftp_tree, hf_tftp_error_string, tvb, offset,
+ i1, FALSE);
+ }
+ if (check_col(pinfo->cinfo, COL_INFO)) {
+ col_append_fstr(pinfo->cinfo, COL_INFO, ", Message: %s",
+ tvb_get_ptr(tvb, offset, i1));
+ }
+ break;
+
+ case TFTP_OACK:
+ if (tree)
+ tftp_dissect_options(tvb, offset, tftp_tree);
+ break;
+
+ default:
+ if (tree) {
+ proto_tree_add_text(tftp_tree, tvb, offset, -1,
+ "Data (%d bytes)", tvb_reported_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));
+
+ tftp_handle = create_dissector_handle(dissect_tftp, proto_tftp);
+}
+
+void
+proto_reg_handoff_tftp(void)
+{
+ dissector_add("udp.port", UDP_PORT_TFTP, tftp_handle);
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-24 04:59:49 +0000