2 * Routines for ftp packet dissection
3 * Copyright 1999, Richard Sharpe <rsharpe@ns.aus.com>
4 * Copyright 2001, Juan Toledo <toledo@users.sourceforge.net> (Passive FTP)
6 * $Id: packet-ftp.c,v 1.50 2003/02/25 19:27:19 guy Exp $
8 * Ethereal - Network traffic analyzer
9 * By Gerald Combs <gerald@ethereal.com>
10 * Copyright 1998 Gerald Combs
12 * Copied from packet-pop.c
14 * This program is free software; you can redistribute it and/or
15 * modify it under the terms of the GNU General Public License
16 * as published by the Free Software Foundation; either version 2
17 * of the License, or (at your option) any later version.
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with this program; if not, write to the Free Software
26 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
39 #include <epan/packet.h>
40 #include <epan/strutil.h>
41 #include <epan/conversation.h>
43 static int proto_ftp = -1;
44 static int proto_ftp_data = -1;
45 static int hf_ftp_response = -1;
46 static int hf_ftp_request = -1;
47 static int hf_ftp_request_command = -1;
48 static int hf_ftp_request_arg = -1;
49 static int hf_ftp_response_code = -1;
50 static int hf_ftp_response_arg = -1;
52 static gint ett_ftp = -1;
53 static gint ett_ftp_data = -1;
55 static dissector_handle_t ftpdata_handle;
57 #define TCP_PORT_FTPDATA 20
58 #define TCP_PORT_FTP 21
60 static const value_string response_table[] = {
61 { 110, "Restart marker reply" },
62 { 120, "Service ready in nnn minutes" },
63 { 125, "Data connection already open; transfer starting" },
64 { 150, "File status okay; about to open data connection" },
65 { 200, "Command okay" },
66 { 202, "Command not implemented, superfluous at this site" },
67 { 211, "System status, or system help reply" },
68 { 212, "Directory status" },
69 { 213, "File status" },
70 { 214, "Help message" },
71 { 215, "NAME system type" },
72 { 220, "Service ready for new user" },
73 { 221, "Service closing control connection" },
74 { 225, "Data connection open; no transfer in progress" },
75 { 226, "Closing data connection" },
76 { 227, "Entering Passive Mode" },
77 { 230, "User logged in, proceed" },
78 { 250, "Requested file action okay, completed" },
79 { 257, "PATHNAME created" },
80 { 331, "User name okay, need password" },
81 { 332, "Need account for login" },
82 { 350, "Requested file action pending further information" },
83 { 421, "Service not available, closing control connection" },
84 { 425, "Can't open data connection" },
85 { 426, "Connection closed; transfer aborted" },
86 { 450, "Requested file action not taken" },
87 { 451, "Requested action aborted: local error in processing" },
88 { 452, "Requested action not taken. Insufficient storage space in system" },
89 { 500, "Syntax error, command unrecognized" },
90 { 501, "Syntax error in parameters or arguments" },
91 { 502, "Command not implemented" },
92 { 503, "Bad sequence of commands" },
93 { 504, "Command not implemented for that parameter" },
94 { 530, "Not logged in" },
95 { 532, "Need account for storing files" },
96 { 550, "Requested action not taken: File unavailable" },
97 { 551, "Requested action aborted: page type unknown" },
98 { 552, "Requested file action aborted: Exceeded storage allocation" },
99 { 553, "Requested action not taken: File name not allowed" },
104 dissect_ftpdata(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree);
107 * Handle a response to a PASV command.
109 * We ignore the IP address in the reply, and use the address from which
112 * XXX - are there cases where they differ? What if the FTP server is
113 * behind a NAT box, so that the address it puts into the reply isn't
114 * the address at which you should contact it? Do all NAT boxes detect
115 * FTP PASV replies and rewrite the address? (I suspect not.)
117 * RFC 959 doesn't say much about the syntax of the 227 reply.
119 * A proposal from Dan Bernstein at
121 * http://cr.yp.to/ftp/retr.html
123 * "recommend[s] that clients use the following strategy to parse the
124 * response line: look for the first digit after the initial space; look
125 * for the fourth comma after that digit; read two (possibly negative)
126 * integers, separated by a comma; the TCP port number is p1*256+p2, where
127 * p1 is the first integer modulo 256 and p2 is the second integer modulo
130 * wget 1.5.3 looks for a digit, although it doesn't handle negative
133 * The FTP code in the source of the cURL library, at
135 * http://curl.haxx.se/lxr/source/lib/ftp.c
137 * says that cURL "now scans for a sequence of six comma-separated numbers
138 * and will take them as IP+port indicators"; it loops, doing "sscanf"s
139 * looking for six numbers separated by commas, stepping the start pointer
140 * in the scanf one character at a time - i.e., it tries rather exhaustively.
142 * An optimization would be to scan for a digit, and start there, and if
143 * the scanf doesn't find six values, scan for the next digit and try
144 * again; this will probably succeed on the first try.
146 * The cURL code also says that "found reply-strings include":
148 * "227 Entering Passive Mode (127,0,0,1,4,51)"
149 * "227 Data transfer will passively listen to 127,0,0,1,4,51"
150 * "227 Entering passive mode. 127,0,0,1,4,51"
152 * so it appears that you can't assume there are parentheses around
153 * the address and port number.
156 handle_pasv_response(const guchar *line, int linelen, packet_info *pinfo)
162 int address[4], port[2];
164 conversation_t *conversation;
167 * Copy the rest of the line into a null-terminated buffer.
169 args = g_malloc(linelen + 1);
170 memcpy(args, line, linelen);
171 args[linelen] = '\0';
178 while ((c = *p) != '\0' && !isdigit(c))
183 * We ran out of text without finding anything.
189 * See if we have six numbers.
191 i = sscanf(p, "%d,%d,%d,%d,%d,%d",
192 &address[0], &address[1], &address[2], &address[3],
197 * Set up a conversation, to be dissected as FTP data.
199 server_port = ((port[0] & 0xFF)<<8) | (port[1] & 0xFF);
202 * XXX - should this call to "find_conversation()"
203 * just use "pinfo->src" and "server_port", and
204 * wildcard everything else?
206 conversation = find_conversation(&pinfo->src,
207 &pinfo->dst, PT_TCP, server_port, 0, NO_PORT_B);
208 if (conversation == NULL) {
210 * XXX - should this call to
211 * "conversation_new()" just use "pinfo->src"
212 * and "server_port", and wildcard everything
215 * XXX - what if we did find a conversation?
216 * As we create it only on the first pass
217 * through the packets, if we find one, it's
218 * presumably an unrelated conversation.
219 * Should we remove the old one from the hash
220 * table and put this one in its place?
221 * Can the conversaton code handle
222 * conversations not in the hash table?
224 conversation = conversation_new(&pinfo->src,
225 &pinfo->dst, PT_TCP, server_port, 0,
227 conversation_set_dissector(conversation,
234 * Well, that didn't work. Skip the first number we found,
237 while ((c = *p) != '\0' && isdigit(c))
245 dissect_ftp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
248 proto_tree *ftp_tree = NULL;
254 gboolean is_pasv_response = FALSE;
258 const guchar *next_token;
260 if (pinfo->match_port == pinfo->destport)
265 if (check_col(pinfo->cinfo, COL_PROTOCOL))
266 col_set_str(pinfo->cinfo, COL_PROTOCOL, "FTP");
269 * Find the end of the first line.
271 * Note that "tvb_find_line_end()" will return a value that is
272 * not longer than what's in the buffer, so the "tvb_get_ptr()"
273 * call won't throw an exception.
275 linelen = tvb_find_line_end(tvb, offset, -1, &next_offset, FALSE);
276 line = tvb_get_ptr(tvb, offset, linelen);
278 if (check_col(pinfo->cinfo, COL_INFO)) {
280 * Put the first line from the buffer into the summary
281 * (but leave out the line terminator).
283 col_add_fstr(pinfo->cinfo, COL_INFO, "%s: %s",
284 is_request ? "Request" : "Response",
285 format_text(line, linelen));
289 ti = proto_tree_add_item(tree, proto_ftp, tvb, offset, -1,
291 ftp_tree = proto_item_add_subtree(ti, ett_ftp);
294 proto_tree_add_boolean_hidden(ftp_tree,
295 hf_ftp_request, tvb, 0, 0, TRUE);
296 proto_tree_add_boolean_hidden(ftp_tree,
297 hf_ftp_response, tvb, 0, 0, FALSE);
299 proto_tree_add_boolean_hidden(ftp_tree,
300 hf_ftp_request, tvb, 0, 0, FALSE);
301 proto_tree_add_boolean_hidden(ftp_tree,
302 hf_ftp_response, tvb, 0, 0, TRUE);
308 * Extract the first token, and, if there is a first
309 * token, add it as the request.
311 tokenlen = get_token_len(line, line + linelen, &next_token);
314 proto_tree_add_item(ftp_tree,
315 hf_ftp_request_command, tvb, offset,
321 * This is a response; the response code is 3 digits,
322 * followed by a space or hyphen, possibly followed by
325 * If the line doesn't start with 3 digits, it's part of
328 * XXX - keep track of state in the first pass, and
329 * treat non-continuation lines not beginning with digits
332 if (linelen >= 3 && isdigit(line[0]) && isdigit(line[1])
333 && isdigit(line[2])) {
335 * One-line reply, or first or last line
336 * of a multi-line reply.
338 tvb_get_nstringz0(tvb, offset, 3, code_str);
339 code = strtoul(code_str, NULL, 10);
342 proto_tree_add_uint(ftp_tree,
343 hf_ftp_response_code, tvb, offset, 3, code);
347 * See if it's a passive-mode response.
349 * XXX - check for "229" responses to EPSV
350 * commands, to handle IPv6, as per RFC 2428?
352 * XXX - does anybody do FOOBAR, as per RFC
353 * 1639, or has that been supplanted by RFC 2428?
356 is_pasv_response = TRUE;
359 * Skip the 3 digits and, if present, the
363 next_token = line + 4;
365 next_token = line + linelen;
368 * Line doesn't start with 3 digits; assume it's
369 * a line in the middle of a multi-line reply.
374 offset += next_token - line;
375 linelen -= next_token - line;
379 * If this is a PASV response, handle it if we haven't
380 * already processed this frame.
382 if (!pinfo->fd->flags.visited && is_pasv_response) {
385 * We haven't processed this frame, and it contains
386 * a PASV response; set up a conversation for the
389 handle_pasv_response(line, linelen, pinfo);
395 * Add the rest of the first line as request or
400 proto_tree_add_item(ftp_tree,
401 hf_ftp_request_arg, tvb, offset,
404 proto_tree_add_item(ftp_tree,
405 hf_ftp_response_arg, tvb, offset,
409 offset = next_offset;
412 * Show the rest of the request or response as text,
414 * XXX - only if there's a continuation indicator?
416 while (tvb_offset_exists(tvb, offset)) {
418 * Find the end of the line.
420 linelen = tvb_find_line_end(tvb, offset, -1,
421 &next_offset, FALSE);
426 proto_tree_add_text(ftp_tree, tvb, offset,
427 next_offset - offset, "%s",
428 tvb_format_text(tvb, offset, next_offset - offset));
429 offset = next_offset;
435 dissect_ftpdata(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
437 proto_tree *ti, *ftp_data_tree;
440 if (check_col(pinfo->cinfo, COL_PROTOCOL))
441 col_set_str(pinfo->cinfo, COL_PROTOCOL, "FTP-DATA");
443 if (check_col(pinfo->cinfo, COL_INFO)) {
444 col_add_fstr(pinfo->cinfo, COL_INFO, "FTP Data: %u bytes",
445 tvb_reported_length(tvb));
449 data_length = tvb_length(tvb);
451 ti = proto_tree_add_item(tree, proto_ftp_data, tvb, 0, -1,
453 ftp_data_tree = proto_item_add_subtree(ti, ett_ftp_data);
456 * XXX - if this is binary data, it'll produce
457 * a *really* long line.
459 proto_tree_add_text(ftp_data_tree, tvb, 0, data_length,
460 "FTP Data: %s", tvb_format_text(tvb, 0, data_length));
465 proto_register_ftp(void)
467 static hf_register_info hf[] = {
469 { "Response", "ftp.response",
470 FT_BOOLEAN, BASE_NONE, NULL, 0x0,
471 "TRUE if FTP response", HFILL }},
474 { "Request", "ftp.request",
475 FT_BOOLEAN, BASE_NONE, NULL, 0x0,
476 "TRUE if FTP request", HFILL }},
478 { &hf_ftp_request_command,
479 { "Request command", "ftp.request.command",
480 FT_STRING, BASE_NONE, NULL, 0x0,
483 { &hf_ftp_request_arg,
484 { "Request arg", "ftp.request.arg",
485 FT_STRING, BASE_NONE, NULL, 0x0,
488 { &hf_ftp_response_code,
489 { "Response code", "ftp.response.code",
490 FT_UINT32, BASE_DEC, VALS(response_table), 0x0,
493 { &hf_ftp_response_arg,
494 { "Response arg", "ftp.response.arg",
495 FT_STRING, BASE_NONE, NULL, 0x0,
498 static gint *ett[] = {
503 proto_ftp = proto_register_protocol("File Transfer Protocol (FTP)", "FTP",
505 proto_ftp_data = proto_register_protocol("FTP Data", "FTP-DATA", "ftp-data");
506 proto_register_field_array(proto_ftp, hf, array_length(hf));
507 proto_register_subtree_array(ett, array_length(ett));
509 ftpdata_handle = create_dissector_handle(dissect_ftpdata, proto_ftp_data);
513 proto_reg_handoff_ftp(void)
515 dissector_handle_t ftpdata_handle, ftp_handle;
517 ftpdata_handle = create_dissector_handle(dissect_ftpdata, proto_ftp_data);
518 dissector_add("tcp.port", TCP_PORT_FTPDATA, ftpdata_handle);
519 ftp_handle = create_dissector_handle(dissect_ftp, proto_ftp);
520 dissector_add("tcp.port", TCP_PORT_FTP, ftp_handle);