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-rw-r--r--lib/sqfs/Makemodule.am5
-rw-r--r--lib/sqfs/data_reader.c371
2 files changed, 374 insertions, 2 deletions
diff --git a/lib/sqfs/Makemodule.am b/lib/sqfs/Makemodule.am
index 66d49b6..cb003c0 100644
--- a/lib/sqfs/Makemodule.am
+++ b/lib/sqfs/Makemodule.am
@@ -5,7 +5,8 @@ LIBSQFS_HEARDS = include/sqfs/data.h include/sqfs/meta_writer.h \
include/sqfs/dir.h include/sqfs/xattr.h \
include/sqfs/table.h include/sqfs/predef.h \
include/sqfs/error.h include/sqfs/dir_reader.h \
- include/sqfs/dir_writer.h include/sqfs/io.h
+ include/sqfs/dir_writer.h include/sqfs/io.h \
+ include/sqfs/data_reader.h
libsquashfs_la_SOURCES = $(LIBSQFS_HEARDS) lib/sqfs/id_table.c lib/sqfs/super.c
libsquashfs_la_SOURCES += lib/sqfs/readdir.c lib/sqfs/io_file.c lib/sqfs/xattr.c
@@ -17,7 +18,7 @@ libsquashfs_la_SOURCES += lib/sqfs/read_table.c lib/sqfs/comp/compressor.c
libsquashfs_la_SOURCES += lib/sqfs/io_stdin.c lib/sqfs/comp/internal.h
libsquashfs_la_SOURCES += lib/sqfs/dir_reader.c lib/sqfs/read_tree.c
libsquashfs_la_SOURCES += lib/sqfs/blk_proc/process_block.c lib/sqfs/io.c
-libsquashfs_la_SOURCES += lib/sqfs/blk_proc/internal.h
+libsquashfs_la_SOURCES += lib/sqfs/blk_proc/internal.h lib/sqfs/data_reader.c
libsquashfs_la_CPPFLAGS = $(AM_CPPFLAGS)
libsquashfs_la_CFLAGS = $(AM_CFLAGS) $(PTHREAD_CFLAGS) $(ZLIB_CFLAGS)
libsquashfs_la_CFLAGS += $(XZ_CFLAGS) $(LZO_CFLAGS) $(LZ4_CFLAGS)
diff --git a/lib/sqfs/data_reader.c b/lib/sqfs/data_reader.c
new file mode 100644
index 0000000..3de59ff
--- /dev/null
+++ b/lib/sqfs/data_reader.c
@@ -0,0 +1,371 @@
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/*
+ * data_reader.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#define SQFS_BUILDING_DLL
+#include "config.h"
+
+#include "sqfs/block_processor.h"
+#include "sqfs/data_reader.h"
+#include "sqfs/compress.h"
+#include "sqfs/error.h"
+#include "sqfs/table.h"
+#include "sqfs/inode.h"
+#include "sqfs/data.h"
+#include "sqfs/io.h"
+#include "util.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+struct sqfs_data_reader_t {
+ sqfs_fragment_t *frag;
+ sqfs_compressor_t *cmp;
+ sqfs_block_t *data_block;
+ sqfs_block_t *frag_block;
+
+ uint64_t current_block;
+
+ sqfs_file_t *file;
+
+ uint32_t num_fragments;
+ uint32_t current_frag_index;
+ uint32_t block_size;
+
+ uint8_t scratch[];
+};
+
+static int get_block(sqfs_data_reader_t *data, uint64_t off, uint32_t size,
+ size_t unpacked_size, sqfs_block_t **out)
+{
+ sqfs_block_t *blk = alloc_flex(sizeof(*blk), 1, unpacked_size);
+ size_t on_disk_size;
+ ssize_t ret;
+ int err;
+
+ if (blk == NULL)
+ return SQFS_ERROR_ALLOC;
+
+ blk->size = unpacked_size;
+
+ if (SQFS_IS_SPARSE_BLOCK(size)) {
+ *out = blk;
+ return 0;
+ }
+
+ on_disk_size = SQFS_ON_DISK_BLOCK_SIZE(size);
+
+ if (on_disk_size > unpacked_size)
+ return SQFS_ERROR_OVERFLOW;
+
+ if (SQFS_IS_BLOCK_COMPRESSED(size)) {
+ err = data->file->read_at(data->file, off,
+ data->scratch, on_disk_size);
+ if (err) {
+ free(blk);
+ return err;
+ }
+
+ ret = data->cmp->do_block(data->cmp, data->scratch,
+ on_disk_size, blk->data, blk->size);
+ if (ret <= 0)
+ err = ret < 0 ? ret : SQFS_ERROR_OVERFLOW;
+ } else {
+ err = data->file->read_at(data->file, off,
+ blk->data, on_disk_size);
+ }
+
+ if (err) {
+ free(blk);
+ return err;
+ }
+
+ *out = blk;
+ return 0;
+}
+
+static int precache_data_block(sqfs_data_reader_t *data, uint64_t location,
+ uint32_t size)
+{
+ int ret;
+
+ if (data->data_block != NULL && data->current_block == location)
+ return 0;
+
+ free(data->data_block);
+
+ ret = get_block(data, location, size, data->block_size,
+ &data->data_block);
+
+ if (ret < 0) {
+ data->data_block = NULL;
+ return -1;
+ }
+
+ data->current_block = location;
+ return 0;
+}
+
+static int precache_fragment_block(sqfs_data_reader_t *data, size_t idx)
+{
+ int ret;
+
+ if (data->frag_block != NULL && idx == data->current_frag_index)
+ return 0;
+
+ if (idx >= data->num_fragments)
+ return SQFS_ERROR_OUT_OF_BOUNDS;
+
+ free(data->frag_block);
+
+ ret = get_block(data, data->frag[idx].start_offset,
+ data->frag[idx].size, data->block_size,
+ &data->frag_block);
+ if (ret < 0)
+ return -1;
+
+ data->current_frag_index = idx;
+ return 0;
+}
+
+sqfs_data_reader_t *sqfs_data_reader_create(sqfs_file_t *file,
+ size_t block_size,
+ sqfs_compressor_t *cmp)
+{
+ sqfs_data_reader_t *data = alloc_flex(sizeof(*data), 1, block_size);
+
+ if (data != NULL) {
+ data->file = file;
+ data->block_size = block_size;
+ data->cmp = cmp;
+ }
+
+ return data;
+}
+
+int sqfs_data_reader_load_fragment_table(sqfs_data_reader_t *data,
+ const sqfs_super_t *super)
+{
+ void *raw_frag;
+ size_t size;
+ uint32_t i;
+ int ret;
+
+ free(data->frag_block);
+ free(data->frag);
+
+ data->frag = NULL;
+ data->frag_block = NULL;
+ data->num_fragments = 0;
+ data->current_frag_index = 0;
+
+ if (super->fragment_entry_count == 0 ||
+ (super->flags & SQFS_FLAG_NO_FRAGMENTS) != 0) {
+ return 0;
+ }
+
+ if (super->fragment_table_start >= super->bytes_used)
+ return SQFS_ERROR_OUT_OF_BOUNDS;
+
+ if (SZ_MUL_OV(sizeof(data->frag[0]), super->fragment_entry_count,
+ &size)) {
+ return SQFS_ERROR_OVERFLOW;
+ }
+
+ ret = sqfs_read_table(data->file, data->cmp, size,
+ super->fragment_table_start,
+ super->directory_table_start,
+ super->fragment_table_start, &raw_frag);
+ if (ret)
+ return ret;
+
+ data->num_fragments = super->fragment_entry_count;
+ data->current_frag_index = super->fragment_entry_count;
+ data->frag = raw_frag;
+
+ 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 0;
+}
+
+void sqfs_data_reader_destroy(sqfs_data_reader_t *data)
+{
+ free(data->data_block);
+ free(data->frag_block);
+ free(data->frag);
+ free(data);
+}
+
+int sqfs_data_reader_get_block(sqfs_data_reader_t *data,
+ const sqfs_inode_generic_t *inode,
+ size_t index, sqfs_block_t **out)
+{
+ size_t i, unpacked_size;
+ uint64_t off, filesz;
+
+ if (inode->base.type == SQFS_INODE_FILE) {
+ off = inode->data.file.blocks_start;
+ filesz = inode->data.file.file_size;
+ } else if (inode->base.type == SQFS_INODE_EXT_FILE) {
+ off = inode->data.file_ext.blocks_start;
+ filesz = inode->data.file_ext.file_size;
+ } else {
+ return SQFS_ERROR_NOT_FILE;
+ }
+
+ if (index >= inode->num_file_blocks)
+ return SQFS_ERROR_OUT_OF_BOUNDS;
+
+ for (i = 0; i < index; ++i) {
+ off += SQFS_ON_DISK_BLOCK_SIZE(inode->block_sizes[i]);
+ filesz -= data->block_size;
+ }
+
+ unpacked_size = filesz < data->block_size ? filesz : data->block_size;
+
+ return get_block(data, off, inode->block_sizes[index],
+ unpacked_size, out);
+}
+
+int sqfs_data_reader_get_fragment(sqfs_data_reader_t *data,
+ const sqfs_inode_generic_t *inode,
+ sqfs_block_t **out)
+{
+ uint32_t frag_idx, frag_off, frag_sz;
+ sqfs_block_t *blk;
+ uint64_t filesz;
+
+ if (inode->base.type == SQFS_INODE_EXT_FILE) {
+ filesz = inode->data.file_ext.file_size;
+ frag_idx = inode->data.file_ext.fragment_idx;
+ frag_off = inode->data.file_ext.fragment_offset;
+ } else if (inode->base.type == SQFS_INODE_FILE) {
+ filesz = inode->data.file.file_size;
+ frag_idx = inode->data.file.fragment_index;
+ frag_off = inode->data.file.fragment_offset;
+ } else {
+ return -1;
+ }
+
+ if (inode->num_file_blocks * data->block_size >= filesz) {
+ *out = NULL;
+ return 0;
+ }
+
+ frag_sz = filesz % data->block_size;
+
+ if (precache_fragment_block(data, frag_idx))
+ return -1;
+
+ if (frag_off + frag_sz > data->block_size)
+ return -1;
+
+ blk = alloc_flex(sizeof(*blk), 1, frag_sz);
+ if (blk == NULL)
+ return -1;
+
+ blk->size = frag_sz;
+ memcpy(blk->data, (char *)data->frag_block->data + frag_off, frag_sz);
+
+ *out = blk;
+ return 0;
+}
+
+ssize_t sqfs_data_reader_read(sqfs_data_reader_t *data,
+ const sqfs_inode_generic_t *inode,
+ uint64_t offset, void *buffer, size_t size)
+{
+ uint32_t frag_idx, frag_off;
+ size_t i, diff, total = 0;
+ uint64_t off, filesz;
+ char *ptr;
+
+ /* work out file location and size */
+ if (inode->base.type == SQFS_INODE_EXT_FILE) {
+ off = inode->data.file_ext.blocks_start;
+ filesz = inode->data.file_ext.file_size;
+ frag_idx = inode->data.file_ext.fragment_idx;
+ frag_off = inode->data.file_ext.fragment_offset;
+ } else {
+ off = inode->data.file.blocks_start;
+ filesz = inode->data.file.file_size;
+ frag_idx = inode->data.file.fragment_index;
+ frag_off = inode->data.file.fragment_offset;
+ }
+
+ /* find location of the first block */
+ i = 0;
+
+ while (offset > data->block_size && i < inode->num_file_blocks) {
+ off += SQFS_ON_DISK_BLOCK_SIZE(inode->block_sizes[i++]);
+ offset -= data->block_size;
+
+ if (filesz >= data->block_size) {
+ filesz -= data->block_size;
+ } else {
+ filesz = 0;
+ }
+ }
+
+ /* copy data from blocks */
+ while (i < inode->num_file_blocks && size > 0 && filesz > 0) {
+ diff = data->block_size - offset;
+ if (size < diff)
+ diff = size;
+
+ if (SQFS_IS_SPARSE_BLOCK(inode->block_sizes[i])) {
+ memset(buffer, 0, diff);
+ } else {
+ if (precache_data_block(data, off,
+ inode->block_sizes[i])) {
+ return -1;
+ }
+
+ memcpy(buffer, (char *)data->data_block->data + offset,
+ diff);
+ off += SQFS_ON_DISK_BLOCK_SIZE(inode->block_sizes[i]);
+ }
+
+ if (filesz >= data->block_size) {
+ filesz -= data->block_size;
+ } else {
+ filesz = 0;
+ }
+
+ ++i;
+ offset = 0;
+ size -= diff;
+ total += diff;
+ buffer = (char *)buffer + diff;
+ }
+
+ /* copy from fragment */
+ if (i == inode->num_file_blocks && size > 0 && filesz > 0) {
+ if (precache_fragment_block(data, frag_idx))
+ return -1;
+
+ if (frag_off + filesz > data->block_size)
+ return SQFS_ERROR_OUT_OF_BOUNDS;
+
+ if (offset >= filesz)
+ return total;
+
+ if (offset + size > filesz)
+ size = filesz - offset;
+
+ if (size == 0)
+ return total;
+
+ ptr = (char *)data->frag_block->data + frag_off + offset;
+ memcpy(buffer, ptr, size);
+ total += size;
+ }
+
+ return total;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-25 17:18:36 +0000