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authorDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2019-08-31 16:59:50 +0200
committerDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2019-08-31 17:17:23 +0200
commit2ac43d981859bda063e7067371c1cf246c7f81b0 (patch)
treeca289d2b708a60d13e300cc36ae47839389d26cf /lib/sqfs/data_reader.c
parent9b3d958fb7c37855a63ed75707281c61dc1d44c4 (diff)
Split libsquashfs.a into low seperate libraries
The idea is to make libsquashfs.a independend of libfstree.a, so it becomes a general purpose squashfs manipulation library. All the high level glue code for libfstree.a and utilites that are overly specific with to tools are moved to a seperate librarby. This commit makes the first step by moving the stuff with dependencies on libfstree to a seperate library. Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
Diffstat (limited to 'lib/sqfs/data_reader.c')
-rw-r--r--lib/sqfs/data_reader.c314
1 files changed, 0 insertions, 314 deletions
diff --git a/lib/sqfs/data_reader.c b/lib/sqfs/data_reader.c
deleted file mode 100644
index 4ad6266..0000000
--- a/lib/sqfs/data_reader.c
+++ /dev/null
@@ -1,314 +0,0 @@
-/* SPDX-License-Identifier: GPL-3.0-or-later */
-/*
- * data_reader.c
- *
- * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
- */
-#include "config.h"
-
-#include "data_reader.h"
-#include "highlevel.h"
-#include "util.h"
-
-#include <stdlib.h>
-#include <unistd.h>
-#include <string.h>
-#include <stdio.h>
-
-struct data_reader_t {
- sqfs_fragment_t *frag;
- size_t num_fragments;
- size_t current_frag_index;
- size_t frag_used;
-
- off_t current_block;
-
- compressor_t *cmp;
- size_t block_size;
- int sqfsfd;
-
- void *block;
- void *scratch;
- void *frag_block;
-};
-
-static ssize_t read_block(data_reader_t *data, off_t offset, uint32_t size,
- void *dst)
-{
- bool compressed = SQFS_IS_BLOCK_COMPRESSED(size);
- void *ptr = compressed ? data->scratch : dst;
- ssize_t ret;
-
- size = SQFS_ON_DISK_BLOCK_SIZE(size);
-
- if (size > data->block_size)
- goto fail_bs;
-
- if (read_data_at("reading block", offset, data->sqfsfd, ptr, size))
- return -1;
-
- if (compressed) {
- ret = data->cmp->do_block(data->cmp, data->scratch, size,
- dst, data->block_size);
- if (ret <= 0) {
- fputs("extracting block failed\n", stderr);
- return -1;
- }
- size = ret;
- }
-
- return size;
-fail_bs:
- fputs("found compressed block larger than block size\n", stderr);
- return -1;
-}
-
-static int precache_data_block(data_reader_t *data, off_t location,
- uint32_t size)
-{
- ssize_t ret;
-
- if (data->current_block == location)
- return 0;
-
- ret = read_block(data, location, size, data->block);
- if (ret < 0)
- return -1;
-
- if ((size_t)ret < data->block_size)
- memset((char *)data->block + ret, 0, data->block_size - ret);
-
- data->current_block = location;
- return 0;
-}
-
-static int precache_fragment_block(data_reader_t *data, size_t idx)
-{
- ssize_t ret;
-
- if (idx == data->current_frag_index)
- return 0;
-
- if (idx >= data->num_fragments) {
- fputs("fragment index out of bounds\n", stderr);
- return -1;
- }
-
- ret = read_block(data, data->frag[idx].start_offset,
- data->frag[idx].size, data->frag_block);
- if (ret < 0)
- return -1;
-
- data->current_frag_index = idx;
- data->frag_used = ret;
- return 0;
-}
-
-data_reader_t *data_reader_create(int fd, sqfs_super_t *super,
- compressor_t *cmp)
-{
- data_reader_t *data = alloc_flex(sizeof(*data), super->block_size, 3);
- size_t i, size;
-
- if (data == NULL) {
- perror("creating data reader");
- return data;
- }
-
- data->num_fragments = super->fragment_entry_count;
- data->current_frag_index = super->fragment_entry_count;
- data->block = (char *)data + sizeof(*data);
- data->scratch = (char *)data->block + super->block_size;
- data->frag_block = (char *)data->scratch + super->block_size;
- data->current_block = -1;
- data->sqfsfd = fd;
- data->block_size = super->block_size;
- data->cmp = cmp;
-
- if (super->fragment_entry_count == 0 ||
- (super->flags & SQFS_FLAG_NO_FRAGMENTS) != 0) {
- return data;
- }
-
- if (super->fragment_table_start >= super->bytes_used) {
- fputs("Fragment table start is past end of file\n", stderr);
- free(data);
- return NULL;
- }
-
- if (SZ_MUL_OV(sizeof(data->frag[0]), data->num_fragments, &size)) {
- fputs("Too many fragments: overflow\n", stderr);
- free(data);
- return NULL;
- }
-
- data->frag = sqfs_read_table(fd, cmp, size,
- super->fragment_table_start,
- super->directory_table_start,
- super->fragment_table_start);
- if (data->frag == NULL) {
- free(data);
- return NULL;
- }
-
- for (i = 0; i < data->num_fragments; ++i) {
- data->frag[i].size = le32toh(data->frag[i].size);
- data->frag[i].start_offset =
- le64toh(data->frag[i].start_offset);
- }
-
- return data;
-}
-
-void data_reader_destroy(data_reader_t *data)
-{
- free(data->frag);
- free(data);
-}
-
-int data_reader_dump_file(data_reader_t *data, file_info_t *fi, int outfd,
- bool allow_sparse)
-{
- uint64_t filesz = fi->size;
- size_t fragsz = fi->size % data->block_size;
- size_t count = fi->size / data->block_size;
- off_t off = fi->startblock;
- size_t i, diff;
-
- if (fragsz != 0 && !(fi->flags & FILE_FLAG_HAS_FRAGMENT)) {
- fragsz = 0;
- ++count;
- }
-
- if (allow_sparse && ftruncate(outfd, filesz))
- goto fail_sparse;
-
- for (i = 0; i < count; ++i) {
- diff = filesz > data->block_size ? data->block_size : filesz;
- filesz -= diff;
-
- if (SQFS_IS_SPARSE_BLOCK(fi->blocks[i].size)) {
- if (allow_sparse) {
- if (lseek(outfd, diff, SEEK_CUR) == (off_t)-1)
- goto fail_sparse;
- continue;
- }
- memset(data->block, 0, diff);
- } else {
- if (precache_data_block(data, off, fi->blocks[i].size))
- return -1;
- off += SQFS_ON_DISK_BLOCK_SIZE(fi->blocks[i].size);
- }
-
- if (write_data("writing uncompressed block",
- outfd, data->block, diff)) {
- return -1;
- }
- }
-
- if (fragsz > 0) {
- if (precache_fragment_block(data, fi->fragment))
- return -1;
-
- if (fi->fragment_offset >= data->frag_used)
- goto fail_range;
-
- if ((fi->fragment_offset + fragsz - 1) >= data->frag_used)
- goto fail_range;
-
- if (write_data("writing uncompressed fragment", outfd,
- (char *)data->frag_block + fi->fragment_offset,
- fragsz)) {
- return -1;
- }
- }
-
- return 0;
-fail_range:
- fputs("attempted to read past fragment block limits\n", stderr);
- return -1;
-fail_sparse:
- perror("creating sparse output file");
- return -1;
-}
-
-ssize_t data_reader_read(data_reader_t *data, file_info_t *fi,
- uint64_t offset, void *buffer, size_t size)
-{
- size_t i, diff, fragsz, count, total = 0;
- off_t off;
- char *ptr;
-
- /* work out block count and fragment size */
- fragsz = fi->size % data->block_size;
- count = fi->size / data->block_size;
-
- if (fragsz != 0 && !(fi->flags & FILE_FLAG_HAS_FRAGMENT)) {
- fragsz = 0;
- ++count;
- }
-
- /* work out block index and on-disk location */
- off = fi->startblock;
- i = 0;
-
- while (offset > data->block_size && i < count) {
- off += SQFS_ON_DISK_BLOCK_SIZE(fi->blocks[i++].size);
- offset -= data->block_size;
- }
-
- /* copy data from blocks */
- while (i < count && size > 0) {
- diff = data->block_size - offset;
- if (size < diff)
- size = diff;
-
- if (SQFS_IS_SPARSE_BLOCK(fi->blocks[i].size)) {
- memset(buffer, 0, diff);
- } else {
- if (precache_data_block(data, off, fi->blocks[i].size))
- return -1;
-
- memcpy(buffer, (char *)data->block + offset, diff);
- off += SQFS_ON_DISK_BLOCK_SIZE(fi->blocks[i].size);
- }
-
- ++i;
- offset = 0;
- size -= diff;
- total += diff;
- buffer = (char *)buffer + diff;
- }
-
- /* copy from fragment */
- if (i == count && size > 0 && fragsz > 0) {
- if (precache_fragment_block(data, fi->fragment))
- return -1;
-
- if (fi->fragment_offset >= data->frag_used)
- goto fail_range;
-
- if ((fi->fragment_offset + fragsz - 1) >= data->frag_used)
- goto fail_range;
-
- ptr = (char *)data->frag_block + fi->fragment_offset;
- ptr += offset;
-
- if (offset >= fragsz) {
- offset = 0;
- size = 0;
- }
-
- if (offset + size > fragsz)
- size = fragsz - offset;
-
- if (size > 0) {
- memcpy(buffer, ptr + offset, size);
- total += size;
- }
- }
- return total;
-fail_range:
- fputs("attempted to read past fragment block limits\n", stderr);
- return -1;
-}