6c46a77d95
- The lmfs_get_block*(3) API calls may now return an error. The idea is to encourage a next generation of file system services to do a better job at dealing with block read errors than the MFS-derived implementations do. These existing file systems have been changed to panic immediately upon getting a block read error, in order to let unchecked errors cause corruption. Note that libbdev already retries failing I/O operations a few times first. - The libminixfs block device I/O module (bio.c) now deals properly with end-of-file conditions on block devices. Since a device or partition size may not be a multiple of the root file system's block size, support for partial block retrival has been added, with a new internal lmfs_get_partial_block(3) call. A new test program, test85, tests the new handling of EOF conditions when reading, writing, and memory-mapping a block device. Change-Id: I05e35b6b8851488328a2679da635ebba0c6d08ce
130 lines
3.2 KiB
C
130 lines
3.2 KiB
C
/*
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* This file contains support for System Use Sharing Protocol (SUSP) extension
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* to ISO 9660.
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*/
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#include "inc.h"
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#include <sys/stat.h>
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int parse_susp(struct rrii_dir_record *dir, char *buffer)
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{
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/* Parse fundamental SUSP entries */
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char susp_signature[2];
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u8_t susp_length;
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u8_t susp_version;
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u32_t ca_block_nr;
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u32_t ca_offset;
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u32_t ca_length;
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struct buf *ca_bp;
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int r;
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susp_signature[0] = buffer[0];
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susp_signature[1] = buffer[1];
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susp_length = *((u8_t*)buffer + 2);
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susp_version = *((u8_t*)buffer + 3);
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if ((susp_signature[0] == 'C') && (susp_signature[1] == 'E') &&
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(susp_length >= 28) && (susp_version >= 1)) {
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/*
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* Continuation area, perform a recursion.
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*
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* FIXME: Currently we're parsing only first logical block of a
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* continuation area, and infinite recursion is not checked.
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*/
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ca_block_nr = *((u32_t*)(buffer + 4));
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ca_offset = *((u32_t*)(buffer + 12));
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ca_length = *((u32_t*)(buffer + 20));
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/* Truncate continuation area to fit one logical block. */
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if (ca_offset >= v_pri.logical_block_size_l) {
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return EINVAL;
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}
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if (ca_offset + ca_length > v_pri.logical_block_size_l) {
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ca_length = v_pri.logical_block_size_l - ca_offset;
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}
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r = lmfs_get_block(&ca_bp, fs_dev, ca_block_nr, NORMAL);
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if (r != OK)
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return r;
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parse_susp_buffer(dir, b_data(ca_bp) + ca_offset, ca_length);
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lmfs_put_block(ca_bp);
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return OK;
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}
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else if ((susp_signature[0] == 'P') && (susp_signature[1] == 'D')) {
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/* Padding, skip. */
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return OK;
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}
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else if ((susp_signature[0] == 'S') && (susp_signature[1] == 'P')) {
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/* Ignored, skip. */
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return OK;
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}
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else if ((susp_signature[0] == 'S') && (susp_signature[1] == 'T')) {
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/* Terminator entry, stop processing. */
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return(ECANCELED);
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}
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else if ((susp_signature[0] == 'E') && (susp_signature[1] == 'R')) {
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/* Ignored, skip. */
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return OK;
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}
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else if ((susp_signature[0] == 'E') && (susp_signature[1] == 'S')) {
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/* Ignored, skip. */
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return OK;
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}
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/* Not a SUSP fundamental entry. */
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return EINVAL;
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}
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void parse_susp_buffer(struct rrii_dir_record *dir, char *buffer, u32_t size)
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{
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/*
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* Parse a SUSP system use entry for the ISO 9660.
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* This is the main entry point for parsing SUSP data : SUSP entries are
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* routed from here to the relevant handling functions.
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*/
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char susp_signature[2];
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u8_t susp_length;
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int parser_return;
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while (TRUE) {
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/* A SUSP entry can't be smaller than 4 bytes. */
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if (size < 4)
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return;
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susp_signature[0] = buffer[0];
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susp_signature[1] = buffer[1];
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susp_length = *((u8_t*)buffer + 2);
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/* Check if SUSP entry is present. */
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if (((susp_signature[0] == 0) && (susp_signature[1] == 0)) ||
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(susp_length > size) || (susp_length < 4))
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return;
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/* Check for SUSP fundamental entry. */
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parser_return = parse_susp(dir, buffer);
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if (parser_return == ECANCELED)
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return;
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else if (parser_return == OK)
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goto next_entry;
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/* Check for Rock Ridge entry. */
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if (opt.norock == FALSE) {
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parser_return = parse_susp_rock_ridge(dir, buffer);
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if (parser_return == ECANCELED)
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return;
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else if (parser_return == OK)
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goto next_entry;
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}
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/* Parse next SUSP entry. */
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next_entry:
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buffer += susp_length;
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size -= susp_length;
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}
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}
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