diff options
Diffstat (limited to 'epan/dissectors/packet-ftp.c')
| -rw-r--r-- | epan/dissectors/packet-ftp.c | 1892 |
1 files changed, 1892 insertions, 0 deletions
diff --git a/epan/dissectors/packet-ftp.c b/epan/dissectors/packet-ftp.c new file mode 100644 index 00000000..c53781a9 --- /dev/null +++ b/epan/dissectors/packet-ftp.c @@ -0,0 +1,1892 @@ +/* packet-ftp.c + * Routines for ftp packet dissection + * Copyright 1999, Richard Sharpe <rsharpe@ns.aus.com> + * Copyright 2001, Juan Toledo <toledo@users.sourceforge.net> (Passive FTP) + * + * Wireshark - Network traffic analyzer + * By Gerald Combs <gerald@wireshark.org> + * Copyright 1998 Gerald Combs + * + * Copied from packet-pop.c + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +#include "config.h" + +#include <stdio.h> /* for sscanf() */ +#include <wsutil/strtoi.h> + +#include <epan/packet.h> +#include <epan/strutil.h> +#include <epan/conversation.h> +#include <epan/expert.h> +#include <epan/addr_resolv.h> +#include <epan/proto_data.h> +#include "packet-acdr.h" + +#include <tap.h> +#include <epan/export_object.h> +#include <ui/tap-credentials.h> + +#include "packet-tls.h" +#include "packet-tls-utils.h" + +void proto_register_ftp(void); +void proto_reg_handoff_ftp(void); + +static int credentials_tap = -1; + +static int proto_ftp = -1; +static int proto_ftp_data = -1; +static int hf_ftp_current_working_directory = -1; +static int hf_ftp_response = -1; +static int hf_ftp_request = -1; +static int hf_ftp_request_command = -1; +static int hf_ftp_request_arg = -1; +static int hf_ftp_response_code = -1; +static int hf_ftp_response_arg = -1; +static int hf_ftp_pasv_ip = -1 ; +static int hf_ftp_pasv_port = -1; +static int hf_ftp_pasv_nat = -1; +static int hf_ftp_active_ip = -1; +static int hf_ftp_active_port = -1; +static int hf_ftp_active_nat = -1; +static int hf_ftp_eprt_af = -1; +static int hf_ftp_eprt_ip = -1; +static int hf_ftp_eprt_ipv6 = -1; +static int hf_ftp_eprt_port = -1; +static int hf_ftp_epsv_ip = -1; +static int hf_ftp_epsv_ipv6 = -1; +static int hf_ftp_epsv_port = -1; +static int hf_ftp_command_response_frames = -1; +static int hf_ftp_command_response_bytes = -1; +static int hf_ftp_command_response_first_frame_num = -1; +static int hf_ftp_command_response_last_frame_num = -1; +static int hf_ftp_command_response_duration = -1; +static int hf_ftp_command_response_kbps = -1; +static int hf_ftp_command_setup_frame = -1; +static int hf_ftp_command_command_frame = -1; +static int hf_ftp_command_command = -1; + +static int hf_ftp_data_setup_frame = -1; +static int hf_ftp_data_setup_method = -1; +static int hf_ftp_data_command = -1; +static int hf_ftp_data_command_frame = -1; +static int hf_ftp_data_current_working_directory = -1; + +static gint ett_ftp = -1; +static gint ett_ftp_reqresp = -1; + +static expert_field ei_ftp_eprt_args_invalid = EI_INIT; +static expert_field ei_ftp_epsv_args_invalid = EI_INIT; +static expert_field ei_ftp_response_code_invalid = EI_INIT; +static expert_field ei_ftp_pwd_response_invalid = EI_INIT; + +static int ftp_eo_tap = -1; + +static dissector_handle_t ftpdata_handle; +static dissector_handle_t ftp_handle; +static dissector_handle_t data_text_lines_handle; +static dissector_handle_t tls_handle; + +#define TCP_PORT_FTPDATA 20 +#define TCP_PORT_FTP 21 + +static const value_string response_table[] = { + { 110, "Restart marker reply" }, + { 120, "Service ready in nnn minutes" }, + { 125, "Data connection already open; transfer starting" }, + { 150, "File status okay; about to open data connection" }, + { 200, "Command okay" }, + { 202, "Command not implemented, superfluous at this site" }, + { 211, "System status, or system help reply" }, + { 212, "Directory status" }, + { 213, "File status" }, + { 214, "Help message" }, + { 215, "NAME system type" }, + { 220, "Service ready for new user" }, + { 221, "Service closing control connection" }, + { 225, "Data connection open; no transfer in progress" }, + { 226, "Closing data connection" }, + { 227, "Entering Passive Mode" }, + { 229, "Entering Extended Passive Mode" }, + { 230, "User logged in, proceed" }, + { 232, "User logged in, authorized by security data exchange" }, + { 234, "Security data exchange complete" }, + { 235, "Security data exchange completed successfully" }, + { 250, "Requested file action okay, completed" }, + { 257, "PATHNAME created" }, + { 331, "User name okay, need password" }, + { 332, "Need account for login" }, + { 334, "Requested security mechanism is ok" }, + { 335, "Security data is acceptable, more is required" }, + { 336, "Username okay, need password. Challenge is ..." }, + { 350, "Requested file action pending further information" }, + { 421, "Service not available, closing control connection" }, + { 425, "Can't open data connection" }, + { 426, "Connection closed; transfer aborted" }, + { 431, "Need some unavailable resource to process security" }, + { 450, "Requested file action not taken" }, + { 451, "Requested action aborted: local error in processing" }, + { 452, "Requested action not taken. Insufficient storage space in system" }, + { 500, "Syntax error, command unrecognized" }, + { 501, "Syntax error in parameters or arguments" }, + { 502, "Command not implemented" }, + { 503, "Bad sequence of commands" }, + { 504, "Command not implemented for that parameter" }, + { 522, "Network protocol not supported" }, + { 530, "Not logged in" }, + { 532, "Need account for storing files" }, + { 533, "Command protection level denied for policy reasons" }, + { 534, "Request denied for policy reasons" }, + { 535, "Failed security check (hash, sequence, etc)" }, + { 536, "Requested PROT level not supported by mechanism" }, + { 537, "Command protection level not supported by security mechanism" }, + { 550, "Requested action not taken: File unavailable" }, + { 551, "Requested action aborted: page type unknown" }, + { 552, "Requested file action aborted: Exceeded storage allocation" }, + { 553, "Requested action not taken: File name not allowed" }, + { 631, "Integrity protected reply" }, + { 632, "Confidentiality and integrity protected reply" }, + { 633, "Confidentiality protected reply" }, + { 0, NULL } +}; +static value_string_ext response_table_ext = VALUE_STRING_EXT_INIT(response_table); + +#define EPRT_AF_IPv4 1 +#define EPRT_AF_IPv6 2 +static const value_string eprt_af_vals[] = { + { EPRT_AF_IPv4, "IPv4" }, + { EPRT_AF_IPv6, "IPv6" }, + { 0, NULL } +}; + +/* Used for FTP-DATA's Export Object feature + This will be controlled by the preferences setting "export.maxsize". + It will be used to set the maximum file size for FTP's export + objects (in megabytes). Use 0 for no limit. + */ +static guint pref_export_maxsize = 0; + +typedef struct _ftp_eo_t { + gchar *command; /* Command this data stream answers (e.g., RETR foo.txt) */ + guint32 command_frame; /* Where command for this data was seen */ + guint32 payload_len; /* Length of packet's data */ + gchar *payload_data; /* Packet's data */ +} ftp_eo_t; + +/* Stores mappings of the command packet number to the export object + table's row number, so we can append data from later FTP packets + to the entries. + */ +GHashTable *command_packet_to_eo_row = NULL; + +/* Track which row number in the export object table we're up to */ +guint32 eo_row_count = 0; + +/** + * This is the callback passed to register_export_object() + * as the tap processing function. It will be called each time + * tap_queue_packet() sends a packet to the export objects tap. + * + * The general approach is that when a file transfer begins, + * besides storing the standard export object data, like + * the source system, filename, data, and length, + * an entry is added to the command_packet_to_eo_row hashtable, + * mapping the FTP command packet's number to the + * export object list's row number. + * + * When a later packet has a command packet number + * that's already present in the command_packet_to_eo_row hashtable, + * we detect that's it's a continuation of a previous + * file transfer, so we look up the associated entry in the export + * object list and append the data to there. + * + * FTP is complex in that there's no guarantee that the file transmission + * was completely captured. It might be possible to infer a successful + * transfer with either the "SIZE" command or with a 226 response code + * (indicating that the STOR or RETR command was succesful), but there + * is no guarantee that either of these are present. As such, this + * implementation takes a best-effort approach of simply appending + * all associated ftp-data packets to the export objects entry. + */ +static tap_packet_status +ftp_eo_packet(void *tapdata, packet_info *pinfo, epan_dissect_t *edt _U_, const void *data, tap_flags_t flags _U_) +{ + export_object_list_t *object_list = (export_object_list_t *)tapdata; + const ftp_eo_t *eo_info = (const ftp_eo_t *)data; + + if(eo_info) { /* We have data waiting for us */ + /* Only export files transferred with STOR or RETR*/ + if (strncmp(eo_info->command, "STOR", 4) != 0 && strncmp(eo_info->command, "RETR", 4) != 0) { + return TAP_PACKET_DONT_REDRAW; /* State unchanged - no window updates needed */ + } + /* Create the command_packet_to_eo_row hashtable for mapping the FTP + command packet's number to the export object list's row number */ + if(command_packet_to_eo_row == NULL) { + command_packet_to_eo_row = g_hash_table_new(g_direct_hash, g_direct_equal); + } + if (!g_hash_table_contains(command_packet_to_eo_row, GUINT_TO_POINTER(eo_info->command_frame))) { + /* Command packet not previously seen. Create the new entry in the hashtable. */ + export_object_entry_t *entry = g_new(export_object_entry_t, 1); + entry->pkt_num = pinfo->num; + /* If the command is STOR, the transfer is from the client to the server + If the command is RETR, the transfer is from the server to the client + However, ftp-data will always have the file's origin as pinfo->src */ + entry->hostname = g_strdup(address_to_str(pinfo->pool, &pinfo->src)); + entry->content_type = g_strdup("FTP file"); + + /* Remove the "STOR " or "RETR " to extract the filename */ + if (strlen(eo_info->command) > 5){ + entry->filename = g_strdup(eo_info->command + 5); + } else { + entry->filename = g_strdup("(MISSING)"); + } + + gsize bytes_to_copy; + if (pref_export_maxsize != 0 && (eo_info->payload_len > pref_export_maxsize*1024*1024)) { + bytes_to_copy = pref_export_maxsize*1024*1024; + } + else { + bytes_to_copy = eo_info->payload_len; + } + entry->payload_len = bytes_to_copy; + entry->payload_data = (guint8 *)g_memdup2(eo_info->payload_data, bytes_to_copy); + + /* Add the mapping of the command frame and the export object + list's row number to the hash table */ + g_hash_table_insert(command_packet_to_eo_row, GUINT_TO_POINTER(eo_info->command_frame), GUINT_TO_POINTER(eo_row_count)); + eo_row_count += 1; + object_list->add_entry(object_list->gui_data, entry); + } else { + /* This command packet number is already present in the + command_packet_to_eo_row hashtable, so it's a continuation of + a previous. Let's look up the entry in the export + object list and append the data to there */ + guint32 row_num = GPOINTER_TO_UINT(g_hash_table_lookup(command_packet_to_eo_row, GUINT_TO_POINTER(eo_info->command_frame))); + export_object_entry_t *entry = object_list->get_entry(object_list->gui_data, row_num); + + gsize bytes_to_copy; + if (pref_export_maxsize != 0 && (entry->payload_len + eo_info->payload_len) > pref_export_maxsize*1024*1024) { + bytes_to_copy = pref_export_maxsize*1024*1024 - entry->payload_len; + } + else { + bytes_to_copy = eo_info->payload_len; + } + + entry->payload_data = (guint8 *) g_realloc(entry->payload_data, entry->payload_len + bytes_to_copy); + memcpy(entry->payload_data + entry->payload_len, eo_info->payload_data, bytes_to_copy); + entry->payload_len = entry->payload_len + bytes_to_copy; + } + /* payload_data will be freed when the Export Object window is closed. */ + return TAP_PACKET_REDRAW; /* State changed - window should be redrawn */ + } else { + return TAP_PACKET_DONT_REDRAW; /* State unchanged - no window updates needed */ + } +} + +/** + * This is the callback passed to register_export_object() + * as the reset_cb. This will be used in the export_object module + * to cleanup any previous private data of the export object functionality + * before performing the eo_reset function or when the window closes */ +static void +ftp_eo_cleanup(void) +{ + if(command_packet_to_eo_row != NULL) { + g_hash_table_destroy(command_packet_to_eo_row); + command_packet_to_eo_row = NULL; + } + eo_row_count = 0; +} + + + +/********************************************************************/ +/* Storing session state and linking between control (ftp) and data */ +/* data (ftp-data) conversations */ + +typedef struct ftp_data_conversation_t +{ + const gchar *command; /* Command that this data answers */ + guint32 command_frame; /* Frame command was seen */ + const gchar *setup_method; /* Type of command used to set up data conversation */ + guint32 setup_frame; /* Frame where this happened */ + wmem_strbuf_t *current_working_directory; + + /* Summary details of stream to show in command frame. */ + guint first_frame_num; + nstime_t first_frame_time; + guint last_frame_num; + nstime_t last_frame_time; + guint frames_seen; + guint bytes_seen; +} ftp_data_conversation_t; + +/* Data to associate with individual FTP frame */ +typedef struct ftp_packet_data_t +{ + wmem_strbuf_t *current_working_directory; +} ftp_packet_data_t; + +/* State of FTP conversation */ +typedef struct ftp_conversation_t +{ + const gchar *last_command; /* Most recent request command seen (on first pass) */ + guint32 last_command_frame; /* When request was seen */ + wmem_strbuf_t *current_working_directory; + ftp_data_conversation_t *current_data_conv; /* Current data conversation (during first pass) */ + guint32 current_data_setup_frame; + gchar *username; + guint username_pkt_num; + gboolean tls_requested; +} ftp_conversation_t; + +/* For a given packet, retrieve or initialise a new conversation, and return it */ +static ftp_conversation_t *find_or_create_ftp_conversation(packet_info *pinfo) +{ + /* Create control conversation if necessary */ + conversation_t *conv = find_or_create_conversation(pinfo); + ftp_conversation_t *p_ftp_conv; + + /* Control conversation data */ + p_ftp_conv = (ftp_conversation_t *)conversation_get_proto_data(conv, proto_ftp); + if (!p_ftp_conv) { + p_ftp_conv = wmem_new0(wmem_file_scope(), ftp_conversation_t); + /* Start with an empty string - assume relative path unless/until find out differently. */ + p_ftp_conv->current_working_directory = wmem_strbuf_new(wmem_file_scope(), ""); + conversation_add_proto_data(conv, proto_ftp, p_ftp_conv); + } + + return p_ftp_conv; +} + +/* Keep track of ftp_data_conversation_t*, keyed by the ftp command frame */ +static GHashTable *ftp_command_to_data_hash = NULL; + + +/* When new data conversation is being created, should: + * - create data conversation + * - create control conversation, and have it point at control conversation + */ +static void create_and_link_data_conversation(packet_info *pinfo, + address *addr_a, + guint16 port_a, + address *addr_b, + guint16 port_b, + const char *method) +{ + /* Only to do on first pass */ + if (pinfo->fd->visited) { + return; + } + + ftp_conversation_t *p_ftp_conv = find_or_create_ftp_conversation(pinfo); + + /* Create data conversation and set dissector */ + ftp_data_conversation_t *p_ftp_data_conv; + conversation_t *data_conversation = conversation_new(pinfo->num, + addr_a, addr_b, + CONVERSATION_TCP, + port_a, port_b, + NO_PORT2); + conversation_set_dissector(data_conversation, ftpdata_handle); + + /* Allocate data for data conversation. Note that control conversation will update it with commands. */ + p_ftp_data_conv = wmem_new0(wmem_file_scope(), ftp_data_conversation_t); + /* Set method */ + p_ftp_data_conv->setup_method = method; + /* Copy snapshot of what cwd is at this point */ + p_ftp_data_conv->current_working_directory = p_ftp_conv->current_working_directory; + + /* Point control conversation at current data conversation */ + conversation_add_proto_data(data_conversation, proto_ftp_data, + p_ftp_data_conv); + p_ftp_conv->current_data_conv = p_ftp_data_conv; + p_ftp_conv->current_data_setup_frame = pinfo->num; +} + +/********************************************************************/ + + +/* + * Parse the address and port information in a PORT command or in the + * response to a PASV command. Return TRUE if we found an address and + * port, and supply the address and port; return FALSE if we didn't find + * them. + * + * We ignore the IP address in the reply, and use the address from which + * the request came. + * + * XXX - are there cases where they differ? What if the FTP server is + * behind a NAT box, so that the address it puts into the reply isn't + * the address at which you should contact it? Do all NAT boxes detect + * FTP PASV replies and rewrite the address? (I suspect not.) + * + * RFC 959 doesn't say much about the syntax of the 227 reply. + * + * A proposal from Dan Bernstein at + * + * http://cr.yp.to/ftp/retr.html + * + * "recommend[s] that clients use the following strategy to parse the + * response line: look for the first digit after the initial space; look + * for the fourth comma after that digit; read two (possibly negative) + * integers, separated by a comma; the TCP port number is p1*256+p2, where + * p1 is the first integer modulo 256 and p2 is the second integer modulo + * 256." + * + * wget 1.5.3 looks for a digit, although it doesn't handle negative + * integers. + * + * The FTP code in the source of the cURL library, at + * + * https://github.com/curl/curl/blob/master/lib/ftp.c + * + * says that cURL "now scans for a sequence of six comma-separated numbers + * and will take them as IP+port indicators"; it loops, doing "sscanf"s + * looking for six numbers separated by commas, stepping the start pointer + * in the scanf one character at a time - i.e., it tries rather exhaustively. + * + * An optimization would be to scan for a digit, and start there, and if + * the scanf doesn't find six values, scan for the next digit and try + * again; this will probably succeed on the first try. + * + * The cURL code also says that "found reply-strings include": + * + * "227 Entering Passive Mode (127,0,0,1,4,51)" + * "227 Data transfer will passively listen to 127,0,0,1,4,51" + * "227 Entering passive mode. 127,0,0,1,4,51" + * + * so it appears that you can't assume there are parentheses around + * the address and port number. + */ +static gboolean +parse_port_pasv(tvbuff_t *tvb, int offset, int linelen, guint32 *ftp_ip, + guint16 *ftp_port, guint32 *pasv_offset, guint *ftp_ip_len, + guint *ftp_port_len) +{ + char *args; + char *p; + guchar c; + int i; + int ip_address[4], port[2]; + gboolean ret = FALSE; + + /* + * Copy the rest of the line into a null-terminated buffer. + */ + args = wmem_alloc(wmem_packet_scope(), linelen + 1); + tvb_get_raw_bytes_as_string(tvb, offset, args, linelen + 1); + p = args; + + for (;;) { + /* + * Look for a digit. + */ + while ((c = *p) != '\0' && !g_ascii_isdigit(c)) + p++; + + if (*p == '\0') { + /* + * We ran out of text without finding anything. + */ + break; + } + + /* + * See if we have six numbers. + */ + i = sscanf(p, "%d,%d,%d,%d,%d,%d", + &ip_address[0], &ip_address[1], &ip_address[2], &ip_address[3], + &port[0], &port[1]); + if (i == 6) { + /* + * We have a winner! + */ + *ftp_port = ((port[0] & 0xFF)<<8) | (port[1] & 0xFF); + *ftp_ip = g_htonl((ip_address[0] << 24) | (ip_address[1] <<16) | (ip_address[2] <<8) | ip_address[3]); + *pasv_offset = (guint32)(p - args); + *ftp_port_len = (port[0] < 10 ? 1 : (port[0] < 100 ? 2 : 3 )) + 1 + + (port[1] < 10 ? 1 : (port[1] < 100 ? 2 : 3 )); + *ftp_ip_len = (ip_address[0] < 10 ? 1 : (ip_address[0] < 100 ? 2 : 3)) + 1 + + (ip_address[1] < 10 ? 1 : (ip_address[1] < 100 ? 2 : 3)) + 1 + + (ip_address[2] < 10 ? 1 : (ip_address[2] < 100 ? 2 : 3)) + 1 + + (ip_address[3] < 10 ? 1 : (ip_address[3] < 100 ? 2 : 3)); + ret = TRUE; + break; + } + + /* + * Well, that didn't work. Skip the first number we found, + * and keep trying. + */ + while ((c = *p) != '\0' && g_ascii_isdigit(c)) + p++; + } + + return ret; +} + +static gboolean +isvalid_rfc2428_delimiter(const guchar c) +{ + /* RFC2428 sect. 2 states rules for a valid delimiter */ + const gchar *forbidden = "0123456789abcdef.:"; + if (!g_ascii_isgraph(c)) + return FALSE; + if (strchr(forbidden, g_ascii_tolower(c))) + return FALSE; + return TRUE; +} + + +/* + * RFC2428 states... + * + * AF Number Protocol + * --------- -------- + * 1 Internet Protocol, Version 4 + * 2 Internet Protocol, Version 6 + * + * AF Number Address Format Example + * --------- -------------- ------- + * 1 dotted decimal 132.235.1.2 + * 2 IPv6 string 1080::8:800:200C:417A + * representations + * defined in + * + * The following are sample EPRT commands: + * EPRT |1|132.235.1.2|6275| + * EPRT |2|1080::8:800:200C:417A|5282| + * + * The first command specifies that the server should use IPv4 to open a + * data connection to the host "132.235.1.2" on TCP port 6275. The + * second command specifies that the server should use the IPv6 network + * protocol and the network address "1080::8:800:200C:417A" to open a + * TCP data connection on port 5282. + * + * ... which means in fact that RFC2428 is capable to handle both, + * IPv4 and IPv6 so we have to care about the address family and properly + * act depending on it. + * + */ +static gboolean +parse_eprt_request(tvbuff_t *tvb, int offset, gint linelen, guint32 *eprt_af, + guint32 *eprt_ip, guint16 *eprt_ipv6, guint16 *ftp_port, + guint32 *eprt_ip_len, guint32 *ftp_port_len) +{ + gint delimiters_seen = 0; + gchar delimiter; + gint fieldlen; + gchar *field; + gint n; + gint lastn; + char *args, *p; + gboolean ret = TRUE; + + + /* line contains the EPRT parameters, we need at least the 4 delimiters */ + if (linelen<4) + return FALSE; + + /* Copy the rest of the line into a null-terminated buffer. */ + args = wmem_alloc(wmem_packet_scope(), linelen + 1); + tvb_get_raw_bytes_as_string(tvb, offset, args, linelen + 1); + p = args; + /* + * Handle a NUL being in the line; if there's a NUL in the line, + * strlen(args) will terminate at the NUL and will thus return + * a value less than linelen. + */ + if ((gint)strlen(args) < linelen) + linelen = (gint)strlen(args); + + /* + * RFC2428 sect. 2 states ... + * + * The EPRT command keyword MUST be followed by a single space (ASCII + * 32). Following the space, a delimiter character (<d>) MUST be + * specified. + * + * ... the preceding <space> is already stripped so we know that the first + * character must be the delimiter and has just to be checked to be valid. + */ + if (!isvalid_rfc2428_delimiter(*p)) + return FALSE; /* EPRT command does not follow a vaild delimiter; + * malformed EPRT command - immediate escape */ + + delimiter = *p; + /* Validate that the delimiter occurs 4 times in the string */ + for (n = 0; n < linelen; n++) { + if (*(p+n) == delimiter) + delimiters_seen++; + } + if (delimiters_seen != 4) + return FALSE; /* delimiter doesn't occur 4 times + * probably no EPRT request - immediate escape */ + + /* we know that the first character is a delimiter... */ + delimiters_seen = 1; + lastn = 0; + /* ... so we can start searching from the 2nd onwards */ + for (n=1; n < linelen; n++) { + + if (*(p+n) != delimiter) + continue; + + /* we found a delimiter */ + delimiters_seen++; + + fieldlen = n - lastn - 1; + if (fieldlen<=0) + return FALSE; /* all fields must have data in them */ + field = p + lastn + 1; + + if (delimiters_seen == 2) { /* end of address family field */ + gchar *af_str; + af_str = wmem_strndup(wmem_packet_scope(), field, fieldlen); + if (!ws_strtou32(af_str, NULL, eprt_af)) + return FALSE; + } + else if (delimiters_seen == 3) {/* end of IP address field */ + gchar *ip_str; + ip_str = wmem_strndup(wmem_packet_scope(), field, fieldlen); + + if (*eprt_af == EPRT_AF_IPv4) { + if (str_to_ip(ip_str, eprt_ip)) + ret = TRUE; + else + ret = FALSE; + } + else if (*eprt_af == EPRT_AF_IPv6) { + if (str_to_ip6(ip_str, eprt_ipv6)) + ret = TRUE; + else + ret = FALSE; + } + else + return FALSE; /* invalid/unknown address family */ + + *eprt_ip_len = fieldlen; + } + else if (delimiters_seen == 4) {/* end of port field */ + gchar *pt_str; + pt_str = wmem_strndup(wmem_packet_scope(), field, fieldlen); + + if (!ws_strtou16(pt_str, NULL, ftp_port)) + return FALSE; + *ftp_port_len = fieldlen; + } + + lastn = n; + } + + return ret; +} + +/* + * RFC2428 states .... + * + * The first two fields contained in the parenthesis MUST be blank. The + * third field MUST be the string representation of the TCP port number + * on which the server is listening for a data connection. + * + * The network protocol used by the data connection will be the same network + * protocol used by the control connection. In addition, the network + * address used to establish the data connection will be the same + * network address used for the control connection. + * + * An example response string follows: + * + * Entering Extended Passive Mode (|||6446|) + * + * ... which in fact means that again both address families IPv4 and IPv6 + * are supported. But gladly it's not necessary to parse because it doesn't + * occur in EPSV responses. We can leverage ftp_ip_address which is + * protocol independent and already set. + * + */ +static gboolean +parse_extended_pasv_response(tvbuff_t *tvb, int offset, gint linelen, + guint16 *ftp_port, guint *pasv_offset, guint *ftp_port_len) +{ + gint n; + gchar *args; + gchar *p; + gchar *e; + guchar c; + gboolean ret = FALSE; + gboolean delimiters_seen = FALSE; + + /* + * Copy the rest of the line into a null-terminated buffer. + */ + args = wmem_alloc(wmem_packet_scope(), linelen + 1); + tvb_get_raw_bytes_as_string(tvb, offset, args, linelen + 1); + p = args; + + /* + * Look for ( <d> <d> <d> + (Try to cope with '(' in description) + */ + for (; !delimiters_seen;) { + guchar delimiter = '\0'; + while ((c = *p) != '\0' && (c != '(')) + p++; + + if (*p == '\0') { + return FALSE; + } + + /* Skip '(' */ + p++; + + /* Make sure same delimiter is used 3 times */ + for (n=0; n<3; n++) { + if ((c = *p) != '\0') { + if (delimiter == '\0' && isvalid_rfc2428_delimiter(c)) { + delimiter = c; + } + if (c != delimiter) { + break; + } + p++; + } + else { + break; + } + } + delimiters_seen = TRUE; + } + + /* + * Should now be at digits. + */ + if (*p != '\0') { + const gchar* endptr; + gboolean port_valid; + /* + * We didn't run out of text without finding anything. + */ + port_valid = ws_strtou16(p, &endptr, ftp_port); + /* the conversion returned false, but the converted value could + be valid instead, check it out */ + if (!port_valid && *endptr == '|') + port_valid = TRUE; + if (port_valid) { + *pasv_offset = (guint32)(p - args); + + ret = TRUE; + + /* get port string length */ + if ((e=strchr(p,')')) == NULL) { + ret = FALSE; + } + else { + *ftp_port_len = (guint)(--e - p); + } + } + } + + return ret; +} + +/* Get the last character out of a string */ +static gchar wmem_strbuf_get_last_char(wmem_strbuf_t *string) +{ + gsize len = wmem_strbuf_get_len(string); + if (len > 0) { + const gchar *buf = wmem_strbuf_get_str(string); + return buf[len-1]; + } + else { + /* Error */ + return '\0'; + } +} + +/* Get the nth character out of string */ +static gchar wmem_strbuf_get_char_n(wmem_strbuf_t *string, size_t n) +{ + if (n > wmem_strbuf_get_len(string)-1) { + return '\0'; + } + else { + return wmem_strbuf_get_str(string)[n]; + } +} + +/* Does the path end with the separator character? */ +static gboolean ends_with_separator(wmem_strbuf_t *path) +{ + if (wmem_strbuf_get_len(path) == 0) { + return FALSE; + } + + gchar last = wmem_strbuf_get_last_char(path); + return last == '/'; +} + +/* Does the path begin with the separator character? */ +static gboolean begins_with_separator(wmem_strbuf_t *path) +{ + if (wmem_strbuf_get_len(path) == 0) { + return FALSE; + } + + gchar first = wmem_strbuf_get_char_n(path, 0); + return first == '/'; +} + + +/* Add new_path to the current working directory of the conversation, then normalise. */ +/* N.B. could use e.g. g_build_path() here, but doesn't really buy us anything */ +static void add_directory_to_conv(ftp_conversation_t *conv, const char *new_path) +{ + wmem_strbuf_t *appended_path = wmem_strbuf_new(wmem_packet_scope(), NULL); + + if (!wmem_strbuf_get_len(conv->current_working_directory)) { + /* Currently empty so just assign to new */ + wmem_strbuf_append(conv->current_working_directory, new_path); + return; + } + if (ends_with_separator(conv->current_working_directory)) { + /* Ends in separator, so don't need to write one */ + wmem_strbuf_append_printf(appended_path, "%s%s", wmem_strbuf_get_str(conv->current_working_directory), new_path); + } + else { + /* Separator needed */ + wmem_strbuf_append_printf(appended_path, "%s/%s", wmem_strbuf_get_str(conv->current_working_directory), new_path); + } + + /* Now normalise, by going through the string one directory at a time. If see "..", + remove it and the previous folder. If see ".", ignore it. */ + guint offset; + + /* Initialise with empty path */ + wmem_strbuf_t *normalised_directory = wmem_strbuf_new(wmem_file_scope(), NULL); + wmem_strbuf_t *this_folder = wmem_strbuf_new(wmem_packet_scope(), NULL); + + offset = 0; + /* If absolute, add root to this one too */ + if (begins_with_separator(conv->current_working_directory)) { + wmem_strbuf_append_c(normalised_directory, '/'); + offset++; + } + + /* Now go through the appended path, one directory at a time, and + copy to normalised_directory */ + for (; offset <= wmem_strbuf_get_len(appended_path); offset++) { + gchar ch = wmem_strbuf_get_char_n(appended_path, offset); + if ((offset == wmem_strbuf_get_len(appended_path)) || ch == '/' || ch == '\0') { + /* Folder name is complete */ + if (offset>0 && wmem_strbuf_get_len(this_folder) > 0) { + + /* Up a level. Rewind to before last directory - don't output this one */ + if (strcmp(wmem_strbuf_get_str(this_folder), "..") == 0) { + while (wmem_strbuf_get_len(normalised_directory) && !ends_with_separator(normalised_directory)) { + wmem_strbuf_truncate(normalised_directory, wmem_strbuf_get_len(normalised_directory)-1); + } + /* Potentially skip left-over trailing '/' too */ + if ((wmem_strbuf_get_len(normalised_directory) > 1) && + (wmem_strbuf_get_last_char(normalised_directory) == '/')) { + + wmem_strbuf_truncate(normalised_directory, wmem_strbuf_get_len(normalised_directory)-1); + } + } + /* Current directory - ignore */ + else if (strcmp(wmem_strbuf_get_str(this_folder), ".") == 0) { + /* Don't copy to normalised_directory */ + } + else { + /* Regular directory name - copy this one out */ + if (wmem_strbuf_get_len(normalised_directory) > 0 && !ends_with_separator(normalised_directory)) { + wmem_strbuf_append_c(normalised_directory, '/'); + } + wmem_strbuf_append(normalised_directory, wmem_strbuf_get_str(this_folder)); + } + + /* Reset folder name for next time */ + this_folder = wmem_strbuf_new(wmem_packet_scope(), NULL); + } + } + else { + /* Keep copying this folder name */ + wmem_strbuf_append_c(this_folder, ch); + } + if (ch == '\0') { + /* Reached end - get out of loop */ + break; + } + } + + /* Copy normalised path into conversation */ + conv->current_working_directory = normalised_directory; +} + +/* In response to the arg to a CWD command succeeding, update the conversation's current working directory */ +static void process_cwd_success(ftp_conversation_t *conv, const char *new_path) +{ + if (g_path_is_absolute(new_path)) { + /* Just adopt new_path */ + conv->current_working_directory = wmem_strbuf_new(wmem_file_scope(), new_path); + } + else { + /* Add new_path to what we already have */ + add_directory_to_conv(conv, new_path); + } +} + +/* When get a PWD command response, extract directory and set it in conversation. */ +static void process_pwd_success(ftp_conversation_t *conv, tvbuff_t *tvb, + int offset, int linelen, packet_info *pinfo, + proto_item *pi) +{ + wmem_strbuf_t *output; + const char *line = tvb_get_ptr(tvb, offset, linelen); + gboolean outputStarted = FALSE; + + /* Line must start with quotes */ + if ((linelen < 2) || (line[0] != '"')) { + expert_add_info(pinfo, pi, &ei_ftp_pwd_response_invalid); + return; + } + + output = wmem_strbuf_new(wmem_file_scope(), NULL); + + /* For each character */ + for (offset=0; + (offset < linelen) && (line[offset] != '\r') && (line[offset] != '\n'); + offset++) { + + if (line[offset] == '"') { + if ((offset+1 < linelen) && (line[offset+1] == '"')) { + /* Double, so output one */ + wmem_strbuf_append_c(output, '"'); + offset++; + } + else { + if (outputStarted) { + /* End of path */ + break; + } + outputStarted = TRUE; + } + } + else { + /* Part of path - append */ + wmem_strbuf_append_c(output, line[offset]); + } + } + + /* Make sure output ends in " */ + if (offset >= linelen || line[offset] != '"') { + expert_add_info(pinfo, pi, &ei_ftp_pwd_response_invalid); + wmem_strbuf_destroy(output); + return; + } + + /* Save result - assume it's UTF-8 */ + wmem_strbuf_utf8_make_valid(output); + conv->current_working_directory = output; +} + + +/* Associate the conversation's current working directory with the given packet */ +static void store_directory_in_packet(packet_info *pinfo, ftp_conversation_t *p_ftp_conv) +{ + ftp_packet_data_t *p_packet_data = wmem_new0(wmem_file_scope(), ftp_packet_data_t); + /* Take deep copy of current path, and associate with this packet */ + p_packet_data->current_working_directory = wmem_strbuf_new(wmem_file_scope(), + wmem_strbuf_get_str(p_ftp_conv->current_working_directory)); + p_add_proto_data(wmem_file_scope(), pinfo, proto_ftp, 0, p_packet_data); +} + + +static int +dissect_ftp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_) +{ + gboolean is_request; + proto_tree *ftp_tree; + proto_tree *reqresp_tree; + proto_item *ti, *hidden_item; + gint offset = 0; + guint32 code; + gchar code_str[4]; + gboolean is_port_request = FALSE; + gboolean is_eprt_request = FALSE; + gboolean is_pasv_response = FALSE; + gboolean is_epasv_response = FALSE; + gint next_offset; + gint next_token; + int linelen; + int tokenlen = 0; + guint32 pasv_ip; + guint32 pasv_offset; + guint32 ftp_ip; + guint32 ftp_ip_len; + guint32 eprt_offset; + guint32 eprt_af = 0; + guint32 eprt_ip; + guint16 eprt_ipv6[8]; + guint32 eprt_ip_len = 0; + guint16 ftp_port; + guint32 ftp_port_len; + address ftp_ip_address; + gboolean ftp_nat; + + copy_address_shallow(&ftp_ip_address, &pinfo->src); + + if (pinfo->match_uint == pinfo->destport) + is_request = TRUE; + else + is_request = FALSE; + + col_set_str(pinfo->cinfo, COL_PROTOCOL, "FTP"); + + /* Get the conversation */ + ftp_conversation_t *p_ftp_conv = find_or_create_ftp_conversation(pinfo); + + /* Store the current working directory */ + if (!pinfo->fd->visited) { + store_directory_in_packet(pinfo, p_ftp_conv); + } + + /* + * Find the end of the first line. + * + * Note that "tvb_find_line_end()" will return a value that is + * not longer than what's in the buffer, so the "tvb_get_ptr()" + * call won't throw an exception. + */ + /* + * Both request and reply arguments can be pathnames, which according + * to RFC 2640 MUST be assumed to be UTF-8 if they are valid UTF-8, + * unless explicitly configured to use another character set (and there + * is no official way to do so.) We don't have a preference for character + * set, so we'll display strings as UTF-8 (backwards compatible to ASCII). + * + * XXX: Non valid UTF-8 sequences SHOULD be treated as raw bytes, + * which means that the various extracted strings should be copied + * as raw bytes, and added as FT_BYTES with BASE_SHOW_UTF_8_PRINTABLE. + * That would work better for pathnames that are in a different character + * set, but worse for those intended to be in ASCII/UTF-8 but with errors. + * Pathnames would still need to be converted to a valid string for Export + * Objects, though. + * + * XXX: RFC 2640 allows embedded <CR> and <LF> in pathnames by enforcing + * that ftp commands end with \r\n and requiring that <CR> be padded + * with a <NUL> that is then stripped away upon receipt, similar to Telnet. + */ + linelen = tvb_find_line_end(tvb, 0, -1, &next_offset, FALSE); + + /* + * Put the first line from the buffer into the summary + * (but leave out the line terminator). + */ + col_add_fstr(pinfo->cinfo, COL_INFO, "%s: %s", + is_request ? "Request" : "Response", + tvb_format_text(pinfo->pool, tvb, 0, linelen)); + + ti = proto_tree_add_item(tree, proto_ftp, tvb, 0, -1, ENC_NA); + ftp_tree = proto_item_add_subtree(ti, ett_ftp); + + hidden_item = proto_tree_add_boolean(ftp_tree, + hf_ftp_request, tvb, 0, 0, is_request); + proto_item_set_hidden(hidden_item); + hidden_item = proto_tree_add_boolean(ftp_tree, + hf_ftp_response, tvb, 0, 0, is_request == FALSE); + proto_item_set_hidden(hidden_item); + + /* Put the line into the protocol tree. */ + ti = proto_tree_add_format_text(ftp_tree, tvb, 0, next_offset); + reqresp_tree = proto_item_add_subtree(ti, ett_ftp_reqresp); + + if (is_request) { + /* + * Extract the first token, and, if there is a first + * token, add it as the request. + */ + /* RFC 2640 s3.1: "There MUST be only one <SP> between a ftp command + * and the pathname. Implementations MUST assume <SP> characters + * following the initial <SP> as part of the pathname." + * + * tvb_get_token_len() does not skip trailing spaces, which is + * what we want. (get_token_len() _does_ skip extra spaces.) + */ + tokenlen = tvb_get_token_len(tvb, 0, linelen, &next_token, FALSE); + if (tokenlen != 0) { + proto_tree_add_item(reqresp_tree, hf_ftp_request_command, + tvb, 0, tokenlen, ENC_UTF_8); + if (tvb_strneql(tvb, 0, "PORT", tokenlen) == 0) + is_port_request = TRUE; + /* + * EPRT request command, as per RFC 2428 + */ + else if (tvb_strneql(tvb, 0, "EPRT", tokenlen) == 0) + is_eprt_request = TRUE; + else if (tvb_strneql(tvb, 0, "USER", tokenlen) == 0) { + if (p_ftp_conv && !p_ftp_conv->username && linelen - tokenlen > 1) { + p_ftp_conv->username = tvb_get_string_enc(wmem_file_scope(), tvb, tokenlen + 1, linelen - tokenlen - 1, ENC_UTF_8); + p_ftp_conv->username_pkt_num = pinfo->num; + } + } else if (tvb_strneql(tvb, 0, "PASS", tokenlen) == 0) { + if (p_ftp_conv && p_ftp_conv->username) { + tap_credential_t* auth = wmem_new0(wmem_packet_scope(), tap_credential_t); + auth->num = pinfo->num; + auth->proto = "FTP"; + auth->password_hf_id = hf_ftp_request_arg; + auth->username = p_ftp_conv->username; + auth->username_num = p_ftp_conv->username_pkt_num; + auth->info = wmem_strdup_printf(wmem_packet_scope(), "Username in packet: %u", p_ftp_conv->username_pkt_num); + tap_queue_packet(credentials_tap, pinfo, auth); + } + } + } + + /* If there is an ftp data conversation that doesn't have a + command yet, attempt to update here */ + if (p_ftp_conv) { + p_ftp_conv->last_command = tvb_get_string_enc(wmem_file_scope(), tvb, 0, linelen, ENC_UTF_8); + p_ftp_conv->last_command_frame = pinfo->num; + + if ( (linelen == 8) && ! tvb_strneql(tvb, 0, "AUTH TLS", 8) ) + p_ftp_conv->tls_requested = TRUE; + } + /* And make sure set for FTP data conversation */ + if (p_ftp_conv && p_ftp_conv->current_data_conv && !p_ftp_conv->current_data_conv->command) { + /* Store command and frame where it happened */ + p_ftp_conv->current_data_conv->command = tvb_get_string_enc(wmem_file_scope(), tvb, 0, linelen, ENC_UTF_8); + p_ftp_conv->current_data_conv->command_frame = pinfo->num; + + /* Add to table to ftp-data response can be shown with this frame on later passes */ + g_hash_table_insert(ftp_command_to_data_hash, GUINT_TO_POINTER(pinfo->num), + p_ftp_conv->current_data_conv); + g_hash_table_insert(ftp_command_to_data_hash, GUINT_TO_POINTER(p_ftp_conv->current_data_setup_frame), + p_ftp_conv->current_data_conv); + } + } else { + /* + * This is a response; the response code is 3 digits, + * followed by a space or hyphen, possibly followed by + * text. + * + * If the line doesn't start with 3 digits, it's part of + * a continuation. + * + * XXX - keep track of state in the first pass, and + * treat non-continuation lines not beginning with digits + * as errors? + */ + if (linelen >= 3 && tvb_ascii_isdigit(tvb, 0, 3)) { + gboolean code_valid; + proto_item* pi; + /* + * One-line reply, or first or last line + * of a multi-line reply. + */ + tvb_get_raw_bytes_as_string(tvb, 0, code_str, sizeof code_str); + code_valid = ws_strtou32(code_str, NULL, &code); + + pi = proto_tree_add_uint(reqresp_tree, + hf_ftp_response_code, tvb, 0, 3, code); + + if (!code_valid) + expert_add_info(pinfo, pi, &ei_ftp_response_code_invalid); + + /* + * See if it's a passive-mode response. + * + * XXX - does anybody do FOOBAR, as per RFC + * 1639, or has that been supplanted by RFC 2428? + */ + if (code == 227) + is_pasv_response = TRUE; + + /* + * Responses to EPSV command, as per RFC 2428 + */ + if (code == 229) + is_epasv_response = TRUE; + + /* + * Response to AUTH TLS command as per RFC 4217 + */ + if (code == 234) { + if ( p_ftp_conv->tls_requested ) { + /* AUTH TLS accepted, next reply will be TLS */ + ssl_starttls_ack( tls_handle, pinfo, ftp_handle); + + p_ftp_conv->tls_requested = FALSE ; + } + } + + /* + * Responses to CWD command. + */ + if (code == 250) { + if (!pinfo->fd->visited) { + if (p_ftp_conv && p_ftp_conv->last_command) { + /* Explicit Change Working Directory command */ + if (strncmp(p_ftp_conv->last_command, "CWD ", 4) == 0) { + process_cwd_success(p_ftp_conv, p_ftp_conv->last_command+4); + /* Update path in packet */ + store_directory_in_packet(pinfo, p_ftp_conv); + } + /* Change Directory Up command (i.e. "CWD ..") */ + else if (strncmp(p_ftp_conv->last_command, "CDUP", 4) == 0) { + process_cwd_success(p_ftp_conv, ".."); + /* Update path in packet */ + store_directory_in_packet(pinfo, p_ftp_conv); + } + } + } + } + + /* + * Responses to PWD command. Overwrite whatever is stored - this is the truth! + */ + if (code == 257) { + if (!pinfo->fd->visited) { + if (p_ftp_conv && linelen >= 4) { + /* Want directory name, which will be between " " */ + process_pwd_success(p_ftp_conv, tvb, 4, linelen-4, pinfo, pi); + + /* Update path in packet */ + if (!pinfo->fd->visited) { + store_directory_in_packet(pinfo, p_ftp_conv); + } + } + } + } + + + /* + * Skip the 3 digits and, if present, the + * space or hyphen. + */ + if (linelen >= 4) + next_token = 4; + else + next_token = linelen; + } else { + /* + * Line doesn't start with 3 digits; assume it's + * a line in the middle of a multi-line reply. + */ + next_token = 0; + } + } + + offset = next_token; + linelen -= next_token; + + /* + * Add the rest of the first line as request or + * reply data. + */ + if (linelen != 0) { + if (is_request) { + proto_tree_add_item(reqresp_tree, + hf_ftp_request_arg, tvb, offset, + linelen, ENC_UTF_8); + } else { + proto_tree_add_item(reqresp_tree, + hf_ftp_response_arg, tvb, offset, + linelen, ENC_UTF_8); + } + } + + /* + * If this is a PORT request or a PASV response, handle it. + */ + if (is_port_request) { + if (parse_port_pasv(tvb, offset, linelen, &ftp_ip, &ftp_port, &pasv_offset, &ftp_ip_len, &ftp_port_len)) { + proto_tree_add_ipv4(reqresp_tree, hf_ftp_active_ip, + tvb, pasv_offset + (tokenlen+1) , ftp_ip_len, ftp_ip); + proto_tree_add_uint(reqresp_tree, hf_ftp_active_port, + tvb, pasv_offset + 1 + (tokenlen+1) + ftp_ip_len, ftp_port_len, ftp_port); + set_address(&ftp_ip_address, AT_IPv4, 4, (const guint8 *)&ftp_ip); + ftp_nat = !addresses_equal(&pinfo->src, &ftp_ip_address); + if (ftp_nat) { + proto_tree_add_boolean(reqresp_tree, hf_ftp_active_nat, + tvb, 0, 0, ftp_nat); + } + + /* Set up data conversation */ + create_and_link_data_conversation(pinfo, + &pinfo->dst, 20, + &ftp_ip_address, ftp_port, + "PORT"); + } + } + + if (is_pasv_response) { + if (linelen != 0) { + /* + * This frame contains a PASV response; set up a + * conversation for the data. + */ + if (parse_port_pasv(tvb, offset, linelen, &pasv_ip, &ftp_port, &pasv_offset, &ftp_ip_len, &ftp_port_len)) { + proto_tree_add_ipv4(reqresp_tree, hf_ftp_pasv_ip, + tvb, pasv_offset + 4, ftp_ip_len, pasv_ip); + proto_tree_add_uint(reqresp_tree, hf_ftp_pasv_port, + tvb, pasv_offset + 4 + 1 + ftp_ip_len, ftp_port_len, ftp_port); + set_address(&ftp_ip_address, AT_IPv4, 4, + (const guint8 *)&pasv_ip); + ftp_nat = !addresses_equal(&pinfo->src, &ftp_ip_address); + if (ftp_nat) { + proto_tree_add_boolean(reqresp_tree, hf_ftp_pasv_nat, + tvb, 0, 0, ftp_nat); + } + + create_and_link_data_conversation(pinfo, &ftp_ip_address, ftp_port, &pinfo->dst, pinfo->destport, "PASV"); + } + } + } + + if (is_eprt_request) { + /* + * RFC2428 - sect. 2 + * This frame contains a EPRT request; let's dissect it and set up a + * conversation for the data connection. + */ + if (parse_eprt_request(tvb, offset, linelen, + &eprt_af, &eprt_ip, eprt_ipv6, &ftp_port, + &eprt_ip_len, &ftp_port_len)) { + + /* since parse_eprt_request() returned TRUE, + we know that we have a valid address family */ + eprt_offset = tokenlen + 1 + 1; /* token, space, 1st delimiter */ + proto_tree_add_uint(reqresp_tree, hf_ftp_eprt_af, tvb, + eprt_offset, 1, eprt_af); + eprt_offset += 1 + 1; /* addr family, 2nd delimiter */ + + if (eprt_af == EPRT_AF_IPv4) { + proto_tree_add_ipv4(reqresp_tree, hf_ftp_eprt_ip, + tvb, eprt_offset, eprt_ip_len, eprt_ip); + set_address(&ftp_ip_address, AT_IPv4, 4, + (const guint8 *)&eprt_ip); + } + else if (eprt_af == EPRT_AF_IPv6) { + proto_tree_add_ipv6(reqresp_tree, hf_ftp_eprt_ipv6, + tvb, eprt_offset, eprt_ip_len, (const ws_in6_addr *)eprt_ipv6); + set_address(&ftp_ip_address, AT_IPv6, 16, eprt_ipv6); + } + eprt_offset += eprt_ip_len + 1; /* addr, 3rd delimiter */ + + proto_tree_add_uint(reqresp_tree, hf_ftp_eprt_port, + tvb, eprt_offset, ftp_port_len, ftp_port); + + /* Set up data conversation */ + create_and_link_data_conversation(pinfo, + &pinfo->src, ftp_port, + &ftp_ip_address, 0, + "EPRT"); + } + else { + proto_tree_add_expert(reqresp_tree, pinfo, &ei_ftp_eprt_args_invalid, + tvb, offset - linelen - 1, linelen); + } + } + + if (is_epasv_response) { + if (linelen != 0) { + proto_item *addr_it; + /* + * RFC2428 - sect. 3 + * This frame contains an EPSV response; set up a + * conversation for the data. + */ + if (parse_extended_pasv_response(tvb, offset, linelen, + &ftp_port, &pasv_offset, &ftp_port_len)) { + /* Add IP address and port number to tree */ + + if (ftp_ip_address.type == AT_IPv4) { + guint32 addr; + memcpy(&addr, ftp_ip_address.data, 4); + addr_it = proto_tree_add_ipv4(reqresp_tree, + hf_ftp_epsv_ip, tvb, 0, 0, addr); + proto_item_set_generated(addr_it); + } + else if (ftp_ip_address.type == AT_IPv6) { + addr_it = proto_tree_add_ipv6(reqresp_tree, + hf_ftp_epsv_ipv6, tvb, 0, 0, + (const ws_in6_addr *)ftp_ip_address.data); + proto_item_set_generated(addr_it); + } + + proto_tree_add_uint(reqresp_tree, + hf_ftp_epsv_port, tvb, pasv_offset + 4, + ftp_port_len, ftp_port); + + /* Set up data conversation */ + create_and_link_data_conversation(pinfo, + &ftp_ip_address, ftp_port, + &pinfo->dst, 0, "EPASV"); } + else { + proto_tree_add_expert(reqresp_tree, pinfo, &ei_ftp_epsv_args_invalid, + tvb, offset - linelen - 1, linelen); + } + } + } + + offset = next_offset; + + /* + * Show the rest of the request or response as text, + * a line at a time. + * XXX - only if there's a continuation indicator? + */ + while (tvb_offset_exists(tvb, offset)) { + /* + * Find the end of the line. + */ + tvb_find_line_end(tvb, offset, -1, &next_offset, FALSE); + + /* + * Put this line. + */ + proto_tree_add_format_text(ftp_tree, tvb, offset, + next_offset - offset); + offset = next_offset; + } + + /* Show current working directory */ + ftp_packet_data_t *ftp_packet_data = (ftp_packet_data_t *)p_get_proto_data(wmem_file_scope(), pinfo, proto_ftp, 0); + if (ftp_packet_data != NULL) { + /* Should always be set.. */ + if (ftp_packet_data->current_working_directory) { + proto_item *cwd_ti = proto_tree_add_string(tree, hf_ftp_current_working_directory, + tvb, 0, 0, wmem_strbuf_get_str(ftp_packet_data->current_working_directory)); + proto_item_set_generated(cwd_ti); + } + } + + /* If this is a command resulting in an ftp-data stream, show details */ + if (pinfo->fd->visited) { + /* Look up what has been stored for this frame */ + ftp_data_conversation_t *ftp_data = + (ftp_data_conversation_t *)g_hash_table_lookup(ftp_command_to_data_hash, GUINT_TO_POINTER(pinfo->num)); + if (ftp_data) { + /* Show these for the command frame only */ + if (pinfo->num == ftp_data->command_frame) { + /* Number of frames */ + ti = proto_tree_add_uint(tree, hf_ftp_command_response_frames, + tvb, 0, 0, ftp_data->frames_seen); + proto_item_set_generated(ti); + + /* Number of bytes */ + ti = proto_tree_add_uint(tree, hf_ftp_command_response_bytes, + tvb, 0, 0, ftp_data->bytes_seen); + proto_item_set_generated(ti); + + /* First frame */ + ti = proto_tree_add_uint(tree, hf_ftp_command_response_first_frame_num, + tvb, 0, 0, ftp_data->first_frame_num); + proto_item_set_generated(ti); + + /* Last frame */ + ti = proto_tree_add_uint(tree, hf_ftp_command_response_last_frame_num, + tvb, 0, 0, ftp_data->last_frame_num); + proto_item_set_generated(ti); + + /* Length of stream */ + if (ftp_data->frames_seen > 1) { + /* Work out gap between frames */ + gint seconds = (gint) + (ftp_data->last_frame_time.secs - ftp_data->first_frame_time.secs); + gint nseconds = + ftp_data->last_frame_time.nsecs - ftp_data->first_frame_time.nsecs; + + /* Round gap to nearest ms. */ + gint gap_ms = (seconds*1000) + ((nseconds+500000) / 1000000); + ti = proto_tree_add_uint(tree, hf_ftp_command_response_duration, + tvb, 0, 0, gap_ms); + proto_item_set_generated(ti); + + /* Bitrate (kbps)*/ + guint bitrate = (guint)(((ftp_data->bytes_seen*8.0)/(gap_ms/1000.0))/1000); + ti = proto_tree_add_uint(tree, hf_ftp_command_response_kbps, + tvb, offset, 0, bitrate); + proto_item_set_generated(ti); + } + + ti = proto_tree_add_uint(tree, hf_ftp_command_setup_frame, + tvb, 0, 0, ftp_data->setup_frame); + proto_item_set_generated(ti); + } + + /* Show this only under the setup frame */ + if (pinfo->num == ftp_data->setup_frame) { + ti = proto_tree_add_string(tree, hf_ftp_command_command, + tvb, 0, 0, ftp_data->command); + proto_item_set_generated(ti); + + ti = proto_tree_add_uint(tree, hf_ftp_command_command_frame, + tvb, 0, 0, ftp_data->command_frame); + proto_item_set_generated(ti); + } + } + } + + return tvb_captured_length(tvb); +} + +static int +dissect_ftpdata(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_) +{ + proto_item *data_ti, *ti; + int data_length = tvb_captured_length(tvb); + gboolean is_text = TRUE; + gint check_chars, i; + conversation_t *p_conv; + ftp_data_conversation_t *p_ftp_data_conv; + + col_set_str(pinfo->cinfo, COL_PROTOCOL, "FTP-DATA"); + + col_add_fstr(pinfo->cinfo, COL_INFO, "FTP Data: %u bytes", + tvb_reported_length(tvb)); + + data_ti = proto_tree_add_item(tree, proto_ftp_data, tvb, 0, -1, ENC_NA); + + /* Link back to setup of this stream */ + p_conv = find_conversation_pinfo(pinfo, 0); + + if (p_conv) { + /* Link back to FTP frame where this conversation was created */ + ti = proto_tree_add_uint(tree, hf_ftp_data_setup_frame, + tvb, 0, 0, p_conv->setup_frame); + proto_item_set_generated(ti); + + p_ftp_data_conv = (ftp_data_conversation_t*)conversation_get_proto_data(p_conv, proto_ftp_data); + + if (p_ftp_data_conv) { + /* First time around, update info. */ + if (!pinfo->fd->visited) { + if (!p_ftp_data_conv->first_frame_num) { + p_ftp_data_conv->first_frame_num = pinfo->num; + p_ftp_data_conv->first_frame_time = pinfo->abs_ts; + } + if (pinfo->num > p_ftp_data_conv->last_frame_num) { + p_ftp_data_conv->last_frame_num = pinfo->num; + p_ftp_data_conv->last_frame_time = pinfo->abs_ts; + } + p_ftp_data_conv->frames_seen++; + p_ftp_data_conv->bytes_seen += tvb_reported_length(tvb); + + /* Also store setup_frame here for benefit of ftp (control) */ + p_ftp_data_conv->setup_frame = p_conv->setup_frame; + } + + /* Show setup method as field and in info column */ + if (p_ftp_data_conv->setup_method) { + ti = proto_tree_add_string(tree, hf_ftp_data_setup_method, + tvb, 0, 0, p_ftp_data_conv->setup_method); + col_append_fstr(pinfo->cinfo, COL_INFO, " (%s)", p_ftp_data_conv->setup_method); + proto_item_set_generated(ti); + } + + /* Show command in info column */ + if (p_ftp_data_conv->command) { + ti = proto_tree_add_string(tree, hf_ftp_data_command, + tvb, 0, 0, p_ftp_data_conv->command); + proto_item_set_generated(ti); + col_append_fstr(pinfo->cinfo, COL_INFO, " (%s)", p_ftp_data_conv->command); + + proto_tree_add_uint(tree, hf_ftp_data_command_frame, + tvb, 0, 0, p_ftp_data_conv->command_frame); + proto_item_set_generated(ti); + } + + /* Show current working directory */ + if (p_ftp_data_conv->current_working_directory) { + ti = proto_tree_add_string(tree, hf_ftp_data_current_working_directory, + tvb, 0, 0, wmem_strbuf_get_str(p_ftp_data_conv->current_working_directory)); + proto_item_set_generated(ti); + } + if (have_tap_listener(ftp_eo_tap)) { + if (p_ftp_data_conv->command_frame) { + ftp_eo_t *eo_info = wmem_new0(wmem_packet_scope(), ftp_eo_t); + eo_info->command = wmem_strdup(wmem_packet_scope(), p_ftp_data_conv->command); + eo_info->command_frame = p_ftp_data_conv->command_frame; + eo_info->payload_len = tvb_reported_length(tvb); + eo_info->payload_data = (gchar *) tvb_memdup(wmem_packet_scope(), tvb, 0, tvb_reported_length(tvb)); + tap_queue_packet(ftp_eo_tap, pinfo, eo_info); + } + } + } + } + + /* Check the first few chars to see whether it looks like a text file or output */ + check_chars = MIN(20, data_length); + for (i=0; i < check_chars; i++) { + guint8 c = tvb_get_guint8(tvb, i); + if (c!='\r' && c!='\n' && !g_ascii_isprint(c)) { + is_text = FALSE; + break; + } + } + + /* Show the number of bytes */ + proto_item_append_text(data_ti, " (%u bytes data)", data_length); + + /* Show line-by-line if text */ + if (is_text) { + call_dissector(data_text_lines_handle, tvb, pinfo, tree); + } + + return data_length; +} + +static void ftp_init_protocol(void) +{ + ftp_command_to_data_hash = g_hash_table_new(g_direct_hash, g_direct_equal); +} + +static void ftp_cleanup_protocol(void) +{ + g_hash_table_destroy(ftp_command_to_data_hash); +} + +void +proto_register_ftp(void) +{ + static hf_register_info hf[] = { + { &hf_ftp_current_working_directory, + { "Current working directory", "ftp.current-working-directory", + FT_STRING, BASE_NONE, NULL, 0, + NULL, HFILL }}, + + { &hf_ftp_response, + { "Response", "ftp.response", + FT_BOOLEAN, BASE_NONE, NULL, 0x0, + "TRUE if FTP response", HFILL }}, + + { &hf_ftp_request, + { "Request", "ftp.request", + FT_BOOLEAN, BASE_NONE, NULL, 0x0, + "TRUE if FTP request", HFILL }}, + + { &hf_ftp_request_command, + { "Request command", "ftp.request.command", + FT_STRING, BASE_NONE, NULL, 0x0, + NULL, HFILL }}, + + { &hf_ftp_request_arg, + { "Request arg", "ftp.request.arg", + FT_STRING, BASE_NONE, NULL, 0x0, + NULL, HFILL }}, + + { &hf_ftp_response_code, + { "Response code", "ftp.response.code", + FT_UINT32, BASE_DEC|BASE_EXT_STRING, &response_table_ext, 0x0, + NULL, HFILL }}, + + { &hf_ftp_response_arg, + { "Response arg", "ftp.response.arg", + FT_STRING, BASE_NONE, NULL, 0x0, + NULL, HFILL }}, + + { &hf_ftp_pasv_ip, + { "Passive IP address", "ftp.passive.ip", + FT_IPv4, BASE_NONE, NULL,0x0, + "Passive IP address (check NAT)", HFILL}}, + + { &hf_ftp_pasv_port, + { "Passive port", "ftp.passive.port", + FT_UINT16, BASE_DEC, NULL,0x0, + "Passive FTP server port", HFILL }}, + + { &hf_ftp_pasv_nat, + {"Passive IP NAT", "ftp.passive.nat", + FT_BOOLEAN, BASE_NONE, NULL, 0x0, + "NAT is active SIP and passive IP different", HFILL }}, + + { &hf_ftp_active_ip, + { "Active IP address", "ftp.active.cip", + FT_IPv4, BASE_NONE, NULL, 0x0, + "Active FTP client IP address", HFILL }}, + + { &hf_ftp_active_port, + {"Active port", "ftp.active.port", + FT_UINT16, BASE_DEC, NULL, 0x0, + "Active FTP client port", HFILL }}, + + { &hf_ftp_active_nat, + { "Active IP NAT", "ftp.active.nat", + FT_BOOLEAN, BASE_NONE, NULL, 0x0, + "NAT is active", HFILL}}, + + { &hf_ftp_eprt_af, + { "Extended active address family", "ftp.eprt.af", + FT_UINT8, BASE_DEC, VALS(eprt_af_vals), 0, + NULL, HFILL }}, + + { &hf_ftp_eprt_ip, + { "Extended active IP address", "ftp.eprt.ip", + FT_IPv4, BASE_NONE, NULL, 0, + "Extended active FTP client IPv4 address", HFILL }}, + + { &hf_ftp_eprt_ipv6, + { "Extended active IPv6 address", "ftp.eprt.ipv6", + FT_IPv6, BASE_NONE, NULL, 0, + "Extended active FTP client IPv6 address", HFILL }}, + + { &hf_ftp_eprt_port, + { "Extended active port", "ftp.eprt.port", + FT_UINT16, BASE_DEC, NULL, 0, + "Extended active FTP client listener port", HFILL }}, + + { &hf_ftp_epsv_ip, + { "Extended passive IPv4 address", "ftp.epsv.ip", + FT_IPv4, BASE_NONE, NULL, 0, + "Extended passive FTP server IPv4 address", HFILL }}, + + { &hf_ftp_epsv_ipv6, + { "Extended passive IPv6 address", "ftp.epsv.ipv6", + FT_IPv6, BASE_NONE, NULL, 0, + "Extended passive FTP server IPv6 address", HFILL }}, + + { &hf_ftp_epsv_port, + { "Extended passive port", "ftp.epsv.port", + FT_UINT16, BASE_DEC, NULL, 0, + "Extended passive FTP server port", HFILL }}, + + { &hf_ftp_command_response_first_frame_num, + { "Command response first frame", "ftp.command-response.first-frame-num", + FT_FRAMENUM, BASE_NONE, FRAMENUM_TYPE(FT_FRAMENUM_RESPONSE), 0, + "First frame seen in resulting ftp-data stream", HFILL }}, + + { &hf_ftp_command_response_last_frame_num, + { "Command response last frame", "ftp.command-response.last-frame-num", + FT_FRAMENUM, BASE_NONE, FRAMENUM_TYPE(FT_FRAMENUM_RESPONSE), 0, + "Last frame seen in resulting ftp-data stream", HFILL }}, + + { &hf_ftp_command_response_duration, + { "Response duration", "ftp.command-response.duration", + FT_UINT32, BASE_DEC|BASE_UNIT_STRING, &units_milliseconds, 0, + "Duration of command response in ms", HFILL }}, + + { &hf_ftp_command_response_kbps, + { "Response bitrate", "ftp.command-response.bitrate", + FT_UINT32, BASE_DEC|BASE_UNIT_STRING, &units_kbps, 0, + "Bitrate of command response", HFILL }}, + + { &hf_ftp_command_response_frames, + { "Command response frames", "ftp.command-response.frames", + FT_UINT32, BASE_DEC, NULL, 0, + "Number of frames seen in resulting ftp-data stream", HFILL }}, + + { &hf_ftp_command_response_bytes, + { "Command response bytes", "ftp.command-response.bytes", + FT_UINT32, BASE_DEC, NULL, 0, + "Number of bytes seen in resulting ftp-data stream", HFILL }}, + + { &hf_ftp_command_setup_frame, + { "Setup frame", "ftp.setup-frame", + FT_FRAMENUM, BASE_NONE, FRAMENUM_TYPE(FT_FRAMENUM_REQUEST), 0, + "Where ftp-data conversation for this command was signalled", HFILL }}, + + { &hf_ftp_command_command_frame, + { "Command frame", "ftp.command-frame", + FT_FRAMENUM, BASE_NONE, FRAMENUM_TYPE(FT_FRAMENUM_REQUEST), 0, + "Where command for setup was seen", HFILL }}, + + { &hf_ftp_command_command, + { "Command", "ftp.command", + FT_STRING, BASE_NONE, NULL, 0, + "Command corresponding to this setup frame", HFILL }}, + }; + static gint *ett[] = { + &ett_ftp, + &ett_ftp_reqresp + }; + + static hf_register_info data_hf[] = { + { &hf_ftp_data_setup_frame, + { "Setup frame", "ftp-data.setup-frame", + FT_FRAMENUM, BASE_NONE, NULL, 0, + "Where ftp-data conversation was signalled", HFILL }}, + + { &hf_ftp_data_setup_method, + { "Setup method", "ftp-data.setup-method", + FT_STRING, BASE_NONE, NULL, 0, + "Method used to set up data conversation", HFILL }}, + + { &hf_ftp_data_command, + { "Command", "ftp-data.command", + FT_STRING, BASE_NONE, NULL, 0, + "Command that this data stream answers", HFILL }}, + + { &hf_ftp_data_command_frame, + { "Command frame", "ftp-data.command-frame", + FT_FRAMENUM, BASE_NONE, NULL, 0, + "Where command for this data was seen", HFILL }}, + + { &hf_ftp_data_current_working_directory, + { "Current working directory", "ftp-data.current-working-directory", + FT_STRING, BASE_NONE, NULL, 0, + "Current working directory at time of command", HFILL }} + }; + + static ei_register_info ei[] = { + { &ei_ftp_eprt_args_invalid, { "ftp.eprt.args_invalid", PI_MALFORMED, PI_WARN, "EPRT arguments must have the form: |<family>|<addr>|<port>|", EXPFILL }}, + { &ei_ftp_epsv_args_invalid, { "ftp.epsv.args_invalid", PI_MALFORMED, PI_WARN, "EPSV arguments must have the form (|||<port>|)", EXPFILL }}, + { &ei_ftp_response_code_invalid, { "ftp.response.code.invalid", PI_MALFORMED, PI_ERROR, "Invalid response code", EXPFILL }}, + { &ei_ftp_pwd_response_invalid, { "ftp.response.pwd.invalid", PI_MALFORMED, PI_ERROR, "Invalid PWD response", EXPFILL }} + }; + + expert_module_t* expert_ftp; + + proto_ftp = proto_register_protocol("File Transfer Protocol (FTP)", "FTP", "ftp"); + + ftp_handle = register_dissector("ftp", dissect_ftp, proto_ftp); + proto_ftp_data = proto_register_protocol("FTP Data", "FTP-DATA", "ftp-data"); + ftpdata_handle = register_dissector("ftp-data", dissect_ftpdata, proto_ftp_data); + proto_register_field_array(proto_ftp, hf, array_length(hf)); + proto_register_field_array(proto_ftp, data_hf, array_length(data_hf)); + proto_register_subtree_array(ett, array_length(ett)); + expert_ftp = expert_register_protocol(proto_ftp); + expert_register_field_array(expert_ftp, ei, array_length(ei)); + + register_init_routine(&ftp_init_protocol); + register_cleanup_routine(&ftp_cleanup_protocol); + + credentials_tap = register_tap("credentials"); + + module_t *ftp_prefs_module = prefs_register_protocol(proto_ftp_data, NULL); + prefs_register_uint_preference(ftp_prefs_module, "export.maxsize", + "Max file size (in MB) for export objects (use 0 for unlimited)", /* Title */ + "Maximum file size (in megabytes) for export objects (use 0 for unlimited).", /* Description */ + 10, + &pref_export_maxsize); + ftp_eo_tap = register_export_object(proto_ftp_data, ftp_eo_packet, ftp_eo_cleanup); +} + +void +proto_reg_handoff_ftp(void) +{ + dissector_add_uint_with_preference("tcp.port", TCP_PORT_FTPDATA, ftpdata_handle); + dissector_add_uint_with_preference("tcp.port", TCP_PORT_FTP, ftp_handle); + dissector_add_uint("acdr.tls_application", TLS_APP_FTP, ftp_handle); + + data_text_lines_handle = find_dissector_add_dependency("data-text-lines", proto_ftp_data); + + tls_handle = find_dissector( "tls" ); +} + +/* + * Editor modelines - https://www.wireshark.org/tools/modelines.html + * + * Local variables: + * c-basic-offset: 4 + * tab-width: 8 + * indent-tabs-mode: nil + * End: + * + * vi: set shiftwidth=4 tabstop=8 expandtab: + * :indentSize=4:tabSize=8:noTabs=true: + */ |