/* ipfix.c * * Wiretap Library * Copyright (c) 1998 by Gilbert Ramirez * * File format support for ipfix file format * Copyright (c) 2010 by Hadriel Kaplan * with generous copying from other wiretaps, such as pcapng * * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ /* File format reference: * RFC 5655 and 5101 * http://tools.ietf.org/rfc/rfc5655 * http://tools.ietf.org/rfc/rfc5101 * * This wiretap is for an ipfix file format reader, per RFC 5655/5101. * All "records" in the file are IPFIX messages, beginning with an IPFIX * message header of 16 bytes as follows from RFC 5101: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Version Number | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Export Time | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sequence Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Observation Domain ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure F: IPFIX Message Header Format * which is then followed by one or more "Sets": Data Sets, Template Sets, * and Options Template Sets. Each Set then has one or more Records in * it. * * All IPFIX files are recorded in big-endian form (network byte order), * per the RFCs. That means if we're on a little-endian system, all * hell will break loose if we don't g_ntohX. * * Since wireshark already has an IPFIX dissector (implemented in * packet-netflow.c), this reader will just set that dissector upon * reading each message. Thus, an IPFIX Message is treated as a packet * as far as the dissector is concerned. */ #include "config.h" #include #include #include #include "wtap-int.h" #include "file_wrappers.h" #include "ipfix.h" #if 0 #define ipfix_debug(...) g_warning(__VA_ARGS__) #else #define ipfix_debug(...) #endif #define RECORDS_FOR_IPFIX_CHECK 20 static gboolean ipfix_read(wtap *wth, int *err, gchar **err_info, gint64 *data_offset); static gboolean ipfix_seek_read(wtap *wth, gint64 seek_off, struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info); #define IPFIX_VERSION 10 /* ipfix: message header */ typedef struct ipfix_message_header_s { guint16 version; guint16 message_length; guint32 export_time_secs; guint32 sequence_number; guint32 observation_id; /* might be 0 for none */ /* x bytes msg_body */ } ipfix_message_header_t; #define IPFIX_MSG_HDR_SIZE 16 /* ipfix: common Set header for every Set type */ typedef struct ipfix_set_header_s { guint16 set_type; guint16 set_length; /* x bytes set_body */ } ipfix_set_header_t; #define IPFIX_SET_HDR_SIZE 4 /* Read IPFIX message header from file. Return true on success. Set *err to * 0 on EOF, any other value for "real" errors (EOF is ok, since return * value is still FALSE) */ static gboolean ipfix_read_message_header(ipfix_message_header_t *pfx_hdr, FILE_T fh, int *err, gchar **err_info) { if (!wtap_read_bytes_or_eof(fh, pfx_hdr, IPFIX_MSG_HDR_SIZE, err, err_info)) return FALSE; /* fix endianess, because IPFIX files are always big-endian */ pfx_hdr->version = g_ntohs(pfx_hdr->version); pfx_hdr->message_length = g_ntohs(pfx_hdr->message_length); pfx_hdr->export_time_secs = g_ntohl(pfx_hdr->export_time_secs); pfx_hdr->sequence_number = g_ntohl(pfx_hdr->sequence_number); pfx_hdr->observation_id = g_ntohl(pfx_hdr->observation_id); /* is the version number one we expect? */ if (pfx_hdr->version != IPFIX_VERSION) { /* Not an ipfix file. */ *err = WTAP_ERR_BAD_FILE; *err_info = g_strdup_printf("ipfix: wrong version %d", pfx_hdr->version); return FALSE; } if (pfx_hdr->message_length < 16) { *err = WTAP_ERR_BAD_FILE; *err_info = g_strdup_printf("ipfix: message length %u is too short", pfx_hdr->message_length); return FALSE; } /* go back to before header */ if (file_seek(fh, 0 - IPFIX_MSG_HDR_SIZE, SEEK_CUR, err) == -1) { ipfix_debug("ipfix_read: couldn't go back in file before header"); return FALSE; } return TRUE; } /* Read IPFIX message header from file and fill in the struct wtap_pkthdr * for the packet, and, if that succeeds, read the packet data. * Return true on success. Set *err to 0 on EOF, any other value for "real" * errors (EOF is ok, since return value is still FALSE). */ static gboolean ipfix_read_message(FILE_T fh, struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info) { ipfix_message_header_t msg_hdr; if (!ipfix_read_message_header(&msg_hdr, fh, err, err_info)) return FALSE; phdr->rec_type = REC_TYPE_PACKET; phdr->presence_flags = WTAP_HAS_TS; phdr->len = msg_hdr.message_length; phdr->caplen = msg_hdr.message_length; phdr->ts.secs = msg_hdr.export_time_secs; phdr->ts.nsecs = 0; return wtap_read_packet_bytes(fh, buf, msg_hdr.message_length, err, err_info); } /* classic wtap: open capture file. Return WTAP_OPEN_MINE on success, * WTAP_OPEN_NOT_MINE on normal failure like malformed format, * WTAP_OPEN_ERROR on bad error like file system */ wtap_open_return_val ipfix_open(wtap *wth, int *err, gchar **err_info) { gint i, n, records_for_ipfix_check = RECORDS_FOR_IPFIX_CHECK; gchar *s; guint16 checked_len = 0; ipfix_message_header_t msg_hdr; ipfix_set_header_t set_hdr; ipfix_debug("ipfix_open: opening file"); /* number of records to scan before deciding if this really is IPFIX */ if ((s = getenv("IPFIX_RECORDS_TO_CHECK")) != NULL) { if ((n = atoi(s)) > 0 && n < 101) { records_for_ipfix_check = n; } } /* * IPFIX is a little hard because there's no magic number; we look at * the first few records and see if they look enough like IPFIX * records. */ for (i = 0; i < records_for_ipfix_check; i++) { /* read first message header to check version */ if (!ipfix_read_message_header(&msg_hdr, wth->fh, err, err_info)) { ipfix_debug("ipfix_open: couldn't read message header #%d with err code #%d (%s)", i, *err, *err_info); if (*err == WTAP_ERR_BAD_FILE) { *err = 0; /* not actually an error in this case */ g_free(*err_info); *err_info = NULL; return WTAP_OPEN_NOT_MINE; } if (*err != 0 && *err != WTAP_ERR_SHORT_READ) return WTAP_OPEN_ERROR; /* real failure */ /* else it's EOF */ if (i < 1) { /* we haven't seen enough to prove this is a ipfix file */ return WTAP_OPEN_NOT_MINE; } /* * If we got here, it's EOF and we haven't yet seen anything * that doesn't look like an IPFIX record - i.e. everything * we've seen looks like an IPFIX record - so we assume this * is an IPFIX file. */ break; } if (file_seek(wth->fh, IPFIX_MSG_HDR_SIZE, SEEK_CUR, err) == -1) { ipfix_debug("ipfix_open: failed seek to next message in file, %d bytes away", msg_hdr.message_length); return WTAP_OPEN_NOT_MINE; } checked_len = IPFIX_MSG_HDR_SIZE; /* check each Set in IPFIX Message for sanity */ while (checked_len < msg_hdr.message_length) { if (!wtap_read_bytes(wth->fh, &set_hdr, IPFIX_SET_HDR_SIZE, err, err_info)) { if (*err == WTAP_ERR_SHORT_READ) { /* Not a valid IPFIX Set, so not an IPFIX file. */ ipfix_debug("ipfix_open: error %d reading set", *err); return WTAP_OPEN_NOT_MINE; } /* A real I/O error; fail. */ return WTAP_OPEN_ERROR; } set_hdr.set_length = g_ntohs(set_hdr.set_length); if ((set_hdr.set_length < IPFIX_SET_HDR_SIZE) || ((set_hdr.set_length + checked_len) > msg_hdr.message_length)) { ipfix_debug("ipfix_open: found invalid set_length of %d", set_hdr.set_length); return WTAP_OPEN_NOT_MINE; } if (file_seek(wth->fh, set_hdr.set_length - IPFIX_SET_HDR_SIZE, SEEK_CUR, err) == -1) { ipfix_debug("ipfix_open: failed seek to next set in file, %d bytes away", set_hdr.set_length - IPFIX_SET_HDR_SIZE); return WTAP_OPEN_ERROR; } checked_len += set_hdr.set_length; } } /* go back to beginning of file */ if (file_seek (wth->fh, 0, SEEK_SET, err) != 0) { return WTAP_OPEN_ERROR; } /* all's good, this is a IPFIX file */ wth->file_encap = WTAP_ENCAP_RAW_IPFIX; wth->snapshot_length = 0; wth->file_tsprec = WTAP_TSPREC_SEC; wth->subtype_read = ipfix_read; wth->subtype_seek_read = ipfix_seek_read; wth->file_type_subtype = WTAP_FILE_TYPE_SUBTYPE_IPFIX; return WTAP_OPEN_MINE; } /* classic wtap: read packet */ static gboolean ipfix_read(wtap *wth, int *err, gchar **err_info, gint64 *data_offset) { *data_offset = file_tell(wth->fh); ipfix_debug("ipfix_read: data_offset is initially %" G_GINT64_MODIFIER "d", *data_offset); if (!ipfix_read_message(wth->fh, &wth->phdr, wth->frame_buffer, err, err_info)) { ipfix_debug("ipfix_read: couldn't read message header with code: %d\n, and error '%s'", *err, *err_info); return FALSE; } return TRUE; } /* classic wtap: seek to file position and read packet */ static gboolean ipfix_seek_read(wtap *wth, gint64 seek_off, struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info) { /* seek to the right file position */ if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1) { ipfix_debug("ipfix_seek_read: couldn't read message header with code: %d\n, and error '%s'", *err, *err_info); return FALSE; /* Seek error */ } ipfix_debug("ipfix_seek_read: reading at offset %" G_GINT64_MODIFIER "u", seek_off); if (!ipfix_read_message(wth->random_fh, phdr, buf, err, err_info)) { ipfix_debug("ipfix_seek_read: couldn't read message header"); if (*err == 0) *err = WTAP_ERR_SHORT_READ; return FALSE; } return TRUE; } /* * Editor modelines - http://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: */