/* classic wtap: seek to file position and read packet */ static gboolean ipfix_seek_read(wtap *wth, gint64 seek_off, union wtap_pseudo_header *pseudo_header, guint8 *pd, int length _U_, int *err, gchar **err_info) { ipfix_message_header_t msg_hdr; (void) pseudo_header; /* avoids compiler warning about unused variable */ /* seek to the right file position */ if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1) { ipfix_debug2("ipfix_seek_read: couldn't read message header with code: %d\n, and error '%s'", *err, *err_info); return FALSE; /* Seek error */ } ipfix_debug1("ipfix_seek_read: reading at offset %" G_GINT64_MODIFIER "u", seek_off); if (!ipfix_read_message_header(&msg_hdr, wth->random_fh, err, err_info)) { ipfix_debug0("ipfix_read: couldn't read message header"); return FALSE; } if(length != (int)msg_hdr.message_length) { *err = WTAP_ERR_BAD_FILE; *err_info = g_strdup_printf("ipfix: record length %u doesn't match requested length %d", msg_hdr.message_length, length); ipfix_debug1("ipfix_seek_read: %s", *err_info); return FALSE; } wtap_file_read_expected_bytes(pd, length, wth->random_fh, err, err_info); return TRUE; }
/* classic wtap: read packet */ static gboolean ipfix_read(wtap *wth, int *err, gchar **err_info, gint64 *data_offset) { ipfix_message_header_t msg_hdr; *data_offset = file_tell(wth->fh); ipfix_debug1("ipfix_read: data_offset is initially %" G_GINT64_MODIFIER "d", *data_offset); if (!ipfix_read_message_header(&msg_hdr, wth->fh, err, err_info)) { ipfix_debug2("ipfix_read: couldn't read message header with code: %d\n, and error '%s'", *err, *err_info); return FALSE; } buffer_assure_space(wth->frame_buffer, msg_hdr.message_length); wtap_file_read_expected_bytes(buffer_start_ptr(wth->frame_buffer), msg_hdr.message_length, wth->fh, err, err_info); wth->phdr.presence_flags = 0; wth->phdr.len = msg_hdr.message_length; wth->phdr.caplen = msg_hdr.message_length; wth->phdr.ts.secs = 0; wth->phdr.ts.nsecs = 0; /*ipfix_debug2("Read length: %u Packet length: %u", msg_hdr.message_length, wth->phdr.caplen);*/ ipfix_debug1("ipfix_read: data_offset is finally %" G_GINT64_MODIFIER "d", file_tell(wth->fh)); 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->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); }
/* 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; /* * The maximum value of msg_hdr.message_length is 65535, which is * less than WTAP_MAX_PACKET_SIZE_STANDARD will ever be, so we don't need * to check it. */ 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 1 on success, 0 on normal failure * like malformed format, -1 on bad error like file system */ int 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_debug0("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_debug3("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 0; } if (*err != 0) return -1; /* real failure */ /* else it's EOF */ if (i < 1) { /* we haven't seen enough to prove this is a ipfix file */ return 0; } /* if we got here, it's EOF and we think it's an ipfix file */ break; } if (file_seek(wth->fh, IPFIX_MSG_HDR_SIZE, SEEK_CUR, err) == -1) { ipfix_debug1("ipfix_open: failed seek to next message in file, %d bytes away", msg_hdr.message_length); return 0; } checked_len = IPFIX_MSG_HDR_SIZE; /* check each Set in IPFIX Message for sanity */ while (checked_len < msg_hdr.message_length) { wtap_file_read_expected_bytes(&set_hdr, IPFIX_SET_HDR_SIZE, wth->fh, err, err_info); 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_debug1("ipfix_open: found invalid set_length of %d", set_hdr.set_length); return 0; } if (file_seek(wth->fh, set_hdr.set_length - IPFIX_SET_HDR_SIZE, SEEK_CUR, err) == -1) { ipfix_debug1("ipfix_open: failed seek to next set in file, %d bytes away", set_hdr.set_length - IPFIX_SET_HDR_SIZE); return 0; } checked_len += set_hdr.set_length; } } /* all's good, this is a IPFIX file */ wth->file_encap = WTAP_ENCAP_RAW_IPFIX; wth->snapshot_length = 0; wth->tsprecision = WTAP_FILE_TSPREC_SEC; wth->subtype_read = ipfix_read; wth->subtype_seek_read = ipfix_seek_read; wth->subtype_close = ipfix_close; wth->file_type = WTAP_FILE_IPFIX; /* go back to beginning of file */ if (file_seek (wth->fh, 0, SEEK_SET, err) != 0) { return -1; } return 1; }
/* 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 (ws_strtoi32(s, NULL, &n) && n > 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; }