/* radcom.c * * Wiretap Library * Copyright (c) 1998 by Gilbert Ramirez * * 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. */ #include "config.h" #include #include #include "wtap-int.h" #include "file_wrappers.h" #include "radcom.h" struct frame_date { guint16 year; guint8 month; guint8 day; guint32 sec; /* seconds since midnight */ guint32 usec; }; struct unaligned_frame_date { char year[2]; char month; char day; char sec[4]; /* seconds since midnight */ char usec[4]; }; /* Found at the beginning of the file. Bytes 2 and 3 (D2:00) seem to be * different in some captures */ static const guint8 radcom_magic[8] = { 0x42, 0xD2, 0x00, 0x34, 0x12, 0x66, 0x22, 0x88 }; static const guint8 encap_magic[4] = { 0x00, 0x42, 0x43, 0x09 }; static const guint8 active_time_magic[11] = { 'A', 'c', 't', 'i', 'v', 'e', ' ', 'T', 'i', 'm', 'e' }; /* RADCOM record header - followed by frame data (perhaps including FCS). "data_length" appears to be the length of packet data following the record header. It's 0 in the last record. "length" appears to be the amount of captured packet data, and "real_length" might be the actual length of the frame on the wire - in some captures, it's the same as "length", and, in others, it's greater than "length". In the last record, however, those may have bogus values (or is that some kind of trailer record?). "xxx" appears to be all-zero in all but the last record in one capture; if so, perhaps this indicates that the last record is, in fact, a trailer of some sort, and some field in the header is a record type. */ struct radcomrec_hdr { char xxx[4]; /* unknown */ char data_length[2]; /* packet length? */ char xxy[5]; /* unknown */ struct unaligned_frame_date date; /* date/time stamp of packet */ char real_length[2]; /* actual length of packet */ char length[2]; /* captured length of packet */ char xxz[2]; /* unknown */ char dce; /* DCE/DTE flag (and other flags?) */ char xxw[9]; /* unknown */ }; static gboolean radcom_read(wtap *wth, int *err, gchar **err_info, gint64 *data_offset); static gboolean radcom_seek_read(wtap *wth, gint64 seek_off, struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info); static gboolean radcom_read_rec(wtap *wth, FILE_T fh, struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info); wtap_open_return_val radcom_open(wtap *wth, int *err, gchar **err_info) { guint8 r_magic[8], t_magic[11], search_encap[7]; struct frame_date start_date; #if 0 guint32 sec; struct tm tm; #endif /* Read in the string that should be at the start of a RADCOM file */ if (!wtap_read_bytes(wth->fh, r_magic, 8, err, err_info)) { if (*err != WTAP_ERR_SHORT_READ) return WTAP_OPEN_ERROR; return WTAP_OPEN_NOT_MINE; } /* XXX: bytes 2 and 3 of the "magic" header seem to be different in some * captures. We force them to our standard value so that the test * succeeds (until we find if they have a special meaning, perhaps a * version number ?) */ r_magic[1] = 0xD2; r_magic[2] = 0x00; if (memcmp(r_magic, radcom_magic, 8) != 0) { return WTAP_OPEN_NOT_MINE; } /* Look for the "Active Time" string. The "frame_date" structure should * be located 32 bytes before the beginning of this string */ if (!wtap_read_bytes(wth->fh, t_magic, 11, err, err_info)) { if (*err != WTAP_ERR_SHORT_READ) return WTAP_OPEN_ERROR; return WTAP_OPEN_NOT_MINE; } while (memcmp(t_magic, active_time_magic, 11) != 0) { if (file_seek(wth->fh, -10, SEEK_CUR, err) == -1) return WTAP_OPEN_ERROR; if (!wtap_read_bytes(wth->fh, t_magic, 11, err, err_info)) { if (*err != WTAP_ERR_SHORT_READ) return WTAP_OPEN_ERROR; return WTAP_OPEN_NOT_MINE; } } if (file_seek(wth->fh, -43, SEEK_CUR, err) == -1) return WTAP_OPEN_ERROR; /* Get capture start time */ if (!wtap_read_bytes(wth->fh, &start_date, sizeof(struct frame_date), err, err_info)) { if (*err != WTAP_ERR_SHORT_READ) return WTAP_OPEN_ERROR; return WTAP_OPEN_NOT_MINE; } /* So what time is this? */ if (!wtap_read_bytes(wth->fh, NULL, sizeof(struct frame_date), err, err_info)) { if (*err != WTAP_ERR_SHORT_READ) return WTAP_OPEN_ERROR; return WTAP_OPEN_NOT_MINE; } for (;;) { if (!wtap_read_bytes(wth->fh, search_encap, 4, err, err_info)) { if (*err != WTAP_ERR_SHORT_READ) return WTAP_OPEN_ERROR; return WTAP_OPEN_NOT_MINE; } if (memcmp(encap_magic, search_encap, 4) == 0) break; /* * OK, that's not it, go forward 1 byte - reading * the magic moved us forward 4 bytes, so seeking * backward 3 bytes moves forward 1 byte - and * try the 4 bytes at that offset. */ if (file_seek(wth->fh, -3, SEEK_CUR, err) == -1) return WTAP_OPEN_ERROR; } if (!wtap_read_bytes(wth->fh, NULL, 12, err, err_info)) { if (*err != WTAP_ERR_SHORT_READ) return WTAP_OPEN_ERROR; return WTAP_OPEN_NOT_MINE; } if (!wtap_read_bytes(wth->fh, search_encap, 4, err, err_info)) { if (*err != WTAP_ERR_SHORT_READ) return WTAP_OPEN_ERROR; return WTAP_OPEN_NOT_MINE; } /* This is a radcom file */ wth->file_type_subtype = WTAP_FILE_TYPE_SUBTYPE_RADCOM; wth->subtype_read = radcom_read; wth->subtype_seek_read = radcom_seek_read; wth->snapshot_length = 0; /* not available in header, only in frame */ wth->file_tsprec = WTAP_TSPREC_USEC; #if 0 tm.tm_year = pletoh16(&start_date.year)-1900; tm.tm_mon = start_date.month-1; tm.tm_mday = start_date.day; sec = pletoh32(&start_date.sec); tm.tm_hour = sec/3600; tm.tm_min = (sec%3600)/60; tm.tm_sec = sec%60; tm.tm_isdst = -1; #endif if (memcmp(search_encap, "LAPB", 4) == 0) wth->file_encap = WTAP_ENCAP_LAPB; else if (memcmp(search_encap, "Ethe", 4) == 0) wth->file_encap = WTAP_ENCAP_ETHERNET; else if (memcmp(search_encap, "ATM/", 4) == 0) wth->file_encap = WTAP_ENCAP_ATM_RFC1483; else { *err = WTAP_ERR_UNSUPPORTED; *err_info = g_strdup_printf("radcom: network type \"%.4s\" unknown", search_encap); return WTAP_OPEN_ERROR; } #if 0 if (!wtap_read_bytes(wth->fh, &next_date, sizeof(struct frame_date), err, err_info)) return WTAP_OPEN_ERROR; while (memcmp(&start_date, &next_date, 4)) { if (file_seek(wth->fh, 1-sizeof(struct frame_date), SEEK_CUR, err) == -1) return WTAP_OPEN_ERROR; if (!wtap_read_bytes(wth->fh, &next_date, sizeof(struct frame_date), err, err_info)) return WTAP_OPEN_ERROR; } #endif if (wth->file_encap == WTAP_ENCAP_ETHERNET) { if (!wtap_read_bytes(wth->fh, NULL, 294, err, err_info)) return WTAP_OPEN_ERROR; } else if (wth->file_encap == WTAP_ENCAP_LAPB) { if (!wtap_read_bytes(wth->fh, NULL, 297, err, err_info)) return WTAP_OPEN_ERROR; } else if (wth->file_encap == WTAP_ENCAP_ATM_RFC1483) { if (!wtap_read_bytes(wth->fh, NULL, 504, err, err_info)) return WTAP_OPEN_ERROR; } return WTAP_OPEN_MINE; } /* Read the next packet */ static gboolean radcom_read(wtap *wth, int *err, gchar **err_info, gint64 *data_offset) { char fcs[2]; *data_offset = file_tell(wth->fh); /* Read record. */ if (!radcom_read_rec(wth, wth->fh, &wth->phdr, wth->frame_buffer, err, err_info)) { /* Read error or EOF */ return FALSE; } if (wth->file_encap == WTAP_ENCAP_LAPB) { /* Read the FCS. XXX - should we have some way of indicating the presence and size of an FCS to our caller? That'd let us handle other file types as well. */ if (!wtap_read_bytes(wth->fh, &fcs, sizeof fcs, err, err_info)) return FALSE; } return TRUE; } static gboolean radcom_seek_read(wtap *wth, gint64 seek_off, struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info) { if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1) return FALSE; /* Read record. */ if (!radcom_read_rec(wth, wth->random_fh, phdr, buf, err, err_info)) { /* Read error or EOF */ if (*err == 0) { /* EOF means "short read" in random-access mode */ *err = WTAP_ERR_SHORT_READ; } return FALSE; } return TRUE; } static gboolean radcom_read_rec(wtap *wth, FILE_T fh, struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info) { struct radcomrec_hdr hdr; guint16 data_length, real_length, length; guint32 sec; struct tm tm; guint8 atmhdr[8]; if (!wtap_read_bytes_or_eof(fh, &hdr, sizeof hdr, err, err_info)) return FALSE; data_length = pletoh16(&hdr.data_length); if (data_length == 0) { /* * The last record appears to have 0 in its "data_length" * field, but non-zero values in other fields, so we * check for that and treat it as an EOF indication. */ *err = 0; return FALSE; } length = pletoh16(&hdr.length); real_length = pletoh16(&hdr.real_length); /* * The maximum value of length is 65535, which is less than * WTAP_MAX_PACKET_SIZE will ever be, so we don't need to check * it. */ phdr->rec_type = REC_TYPE_PACKET; phdr->presence_flags = WTAP_HAS_TS|WTAP_HAS_CAP_LEN; tm.tm_year = pletoh16(&hdr.date.year)-1900; tm.tm_mon = (hdr.date.month&0x0f)-1; tm.tm_mday = hdr.date.day; sec = pletoh32(&hdr.date.sec); tm.tm_hour = sec/3600; tm.tm_min = (sec%3600)/60; tm.tm_sec = sec%60; tm.tm_isdst = -1; phdr->ts.secs = mktime(&tm); phdr->ts.nsecs = pletoh32(&hdr.date.usec) * 1000; switch (wth->file_encap) { case WTAP_ENCAP_ETHERNET: /* XXX - is there an FCS? */ phdr->pseudo_header.eth.fcs_len = -1; break; case WTAP_ENCAP_LAPB: phdr->pseudo_header.x25.flags = (hdr.dce & 0x1) ? 0x00 : FROM_DCE; length -= 2; /* FCS */ real_length -= 2; break; case WTAP_ENCAP_ATM_RFC1483: /* * XXX - is this stuff a pseudo-header? * The direction appears to be in the "hdr.dce" field. */ if (!wtap_read_bytes(fh, atmhdr, sizeof atmhdr, err, err_info)) return FALSE; /* Read error */ length -= 8; real_length -= 8; break; } phdr->len = real_length; phdr->caplen = length; /* * Read the packet data. */ if (!wtap_read_packet_bytes(fh, buf, length, err, err_info)) return FALSE; /* Read error */ return TRUE; } /* * Editor modelines - http://www.wireshark.org/tools/modelines.html * * Local variables: * c-basic-offset: 8 * tab-width: 8 * indent-tabs-mode: t * End: * * vi: set shiftwidth=8 tabstop=8 noexpandtab: * :indentSize=8:tabSize=8:noTabs=false: */