forked from osmocom/wireshark
c0e48778b7
git/epan/dissectors/packet-a21.c:478:25: error: 'item' was marked unused but was used [-Werror,-Wused-but-marked-unused] proto_item_append_text(item, "%s", val_to_str_const(event_id, a21_event_vals, "Unknown")); ^ Added manual change id because file-jpeg.c forced the use of commit -n Change-Id: Iffff53d6253758c8454d9583f0a11f317c8390cb Reviewed-on: https://code.wireshark.org/review/14666 Reviewed-by: Jörg Mayer <jmayer@loplof.de>
194 lines
5.1 KiB
C
194 lines
5.1 KiB
C
/* ber.c
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*
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* Basic Encoding Rules (BER) file reading
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#include "config.h"
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#include <errno.h>
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#include "wtap-int.h"
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#include "file_wrappers.h"
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#include <wsutil/buffer.h>
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#include "ber.h"
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#define BER_CLASS_UNI 0
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#define BER_CLASS_APP 1
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#define BER_CLASS_CON 2
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#define BER_UNI_TAG_SEQ 16 /* SEQUENCE, SEQUENCE OF */
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#define BER_UNI_TAG_SET 17 /* SET, SET OF */
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static gboolean ber_read_file(wtap *wth, FILE_T fh, struct wtap_pkthdr *phdr,
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Buffer *buf, int *err, gchar **err_info)
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{
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gint64 file_size;
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int packet_size;
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if ((file_size = wtap_file_size(wth, err)) == -1)
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return FALSE;
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if (file_size > G_MAXINT) {
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/*
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* Probably a corrupt capture file; don't blow up trying
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* to allocate space for an immensely-large packet.
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*/
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*err = WTAP_ERR_BAD_FILE;
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*err_info = g_strdup_printf("ber: File has %" G_GINT64_MODIFIER "d-byte packet, bigger than maximum of %u",
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file_size, G_MAXINT);
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return FALSE;
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}
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packet_size = (int)file_size;
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phdr->rec_type = REC_TYPE_PACKET;
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phdr->presence_flags = 0; /* yes, we have no bananas^Wtime stamp */
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phdr->caplen = packet_size;
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phdr->len = packet_size;
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phdr->ts.secs = 0;
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phdr->ts.nsecs = 0;
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ws_buffer_assure_space(buf, packet_size);
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return wtap_read_packet_bytes(fh, buf, packet_size, err, err_info);
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}
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static gboolean ber_read(wtap *wth, int *err, gchar **err_info, gint64 *data_offset)
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{
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gint64 offset;
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*err = 0;
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offset = file_tell(wth->fh);
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/* there is only ever one packet */
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if (offset != 0)
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return FALSE;
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*data_offset = offset;
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return ber_read_file(wth, wth->fh, &wth->phdr, wth->frame_buffer, err, err_info);
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}
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static gboolean ber_seek_read(wtap *wth, gint64 seek_off, struct wtap_pkthdr *phdr,
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Buffer *buf, int *err, gchar **err_info)
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{
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/* there is only one packet */
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if(seek_off > 0) {
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*err = 0;
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return FALSE;
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}
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if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
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return FALSE;
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return ber_read_file(wth, wth->random_fh, phdr, buf, err, err_info);
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}
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wtap_open_return_val ber_open(wtap *wth, int *err, gchar **err_info)
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{
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#define BER_BYTES_TO_CHECK 8
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guint8 bytes[BER_BYTES_TO_CHECK];
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guint8 ber_id;
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gint8 ber_class;
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gint8 ber_tag;
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gboolean ber_pc;
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guint8 oct, nlb = 0;
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int len = 0;
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gint64 file_size;
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int offset = 0, i;
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if (!wtap_read_bytes(wth->fh, &bytes, BER_BYTES_TO_CHECK, err, err_info)) {
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if (*err != WTAP_ERR_SHORT_READ)
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return WTAP_OPEN_ERROR;
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return WTAP_OPEN_NOT_MINE;
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}
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ber_id = bytes[offset++];
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ber_class = (ber_id>>6) & 0x03;
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ber_pc = (ber_id>>5) & 0x01;
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ber_tag = ber_id & 0x1F;
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/* it must be constructed and either a SET or a SEQUENCE */
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/* or a CONTEXT/APPLICATION less than 32 (arbitrary) */
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if(!(ber_pc &&
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(((ber_class == BER_CLASS_UNI) && ((ber_tag == BER_UNI_TAG_SET) || (ber_tag == BER_UNI_TAG_SEQ))) ||
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(((ber_class == BER_CLASS_CON) || (ber_class == BER_CLASS_APP)) && (ber_tag < 32)))))
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return WTAP_OPEN_NOT_MINE;
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/* now check the length */
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oct = bytes[offset++];
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if(oct != 0x80) {
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/* not indefinite length encoded */
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if(!(oct & 0x80))
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/* length fits into a single byte */
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len = oct;
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else {
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nlb = oct & 0x7F; /* number of length bytes */
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if((nlb > 0) && (nlb <= (BER_BYTES_TO_CHECK - 2))) {
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/* not indefinite length and we have read enough bytes to compute the length */
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i = nlb;
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while(i--) {
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oct = bytes[offset++];
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len = (len<<8) + oct;
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}
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}
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}
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len += (2 + nlb); /* add back Tag and Length bytes */
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file_size = wtap_file_size(wth, err);
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if(len != file_size) {
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return WTAP_OPEN_NOT_MINE; /* not ASN.1 */
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}
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} else {
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/* Indefinite length encoded - assume it is BER */
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}
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/* seek back to the start of the file */
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if (file_seek(wth->fh, 0, SEEK_SET, err) == -1)
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return WTAP_OPEN_ERROR;
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wth->file_type_subtype = WTAP_FILE_TYPE_SUBTYPE_BER;
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wth->file_encap = WTAP_ENCAP_BER;
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wth->snapshot_length = 0;
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wth->subtype_read = ber_read;
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wth->subtype_seek_read = ber_seek_read;
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wth->file_tsprec = WTAP_TSPREC_SEC;
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return WTAP_OPEN_MINE;
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}
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/*
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* Editor modelines - http://www.wireshark.org/tools/modelines.html
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*
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* Local Variables:
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* c-basic-offset: 2
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* tab-width: 8
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* indent-tabs-mode: nil
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* End:
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*
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* vi: set shiftwidth=2 tabstop=8 expandtab:
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* :indentSize=2:tabSize=8:noTabs=true:
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*/
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