Move library source into src sub-directory

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

1 files changed, 191 insertions, 0 deletions

diff --git a/lib/sqfs/src/meta_reader.c b/lib/sqfs/src/meta_reader.c
new file mode 100644
index 0000000..e431d40
--- /dev/null
+++ b/lib/sqfs/src/meta_reader.c
@@ -0,0 +1,191 @@
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/*
+ * meta_reader.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#define SQFS_BUILDING_DLL
+#include "config.h"
+
+#include "sqfs/meta_reader.h"
+#include "sqfs/compressor.h"
+#include "sqfs/error.h"
+#include "sqfs/block.h"
+#include "sqfs/io.h"
+#include "util/util.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+struct sqfs_meta_reader_t {
+	sqfs_object_t base;
+
+	sqfs_u64 start;
+	sqfs_u64 limit;
+	size_t data_used;
+
+	/* The location of the current block in the image */
+	sqfs_u64 block_offset;
+
+	/* The location of the next block after the current one */
+	sqfs_u64 next_block;
+
+	/* A byte offset into the uncompressed data of the current block */
+	size_t offset;
+
+	/* The underlying file descriptor to read from */
+	sqfs_file_t *file;
+
+	/* A pointer to the compressor to use for extracting data */
+	sqfs_compressor_t *cmp;
+
+	/* The raw data read from the input file */
+	sqfs_u8 data[SQFS_META_BLOCK_SIZE];
+
+	/* The uncompressed data read from the input file */
+	sqfs_u8 scratch[SQFS_META_BLOCK_SIZE];
+};
+
+static void meta_reader_destroy(sqfs_object_t *m)
+{
+	sqfs_meta_reader_t *mr = (sqfs_meta_reader_t *)m;
+
+	sqfs_drop(mr->file);
+	sqfs_drop(mr->cmp);
+	free(m);
+}
+
+static sqfs_object_t *meta_reader_copy(const sqfs_object_t *obj)
+{
+	const sqfs_meta_reader_t *m = (const sqfs_meta_reader_t *)obj;
+	sqfs_meta_reader_t *copy = malloc(sizeof(*copy));
+
+	if (copy != NULL) {
+		memcpy(copy, m, sizeof(*m));
+
+		/* duplicate references */
+		copy->cmp = sqfs_grab(copy->cmp);
+		copy->file = sqfs_grab(copy->file);
+	}
+
+	return (sqfs_object_t *)copy;
+}
+
+sqfs_meta_reader_t *sqfs_meta_reader_create(sqfs_file_t *file,
+					    sqfs_compressor_t *cmp,
+					    sqfs_u64 start, sqfs_u64 limit)
+{
+	sqfs_meta_reader_t *m = calloc(1, sizeof(*m));
+
+	if (m == NULL)
+		return NULL;
+
+	sqfs_object_init(m, meta_reader_destroy, meta_reader_copy);
+
+	m->block_offset = 0xFFFFFFFFFFFFFFFFUL;
+	m->start = start;
+	m->limit = limit;
+	m->file = sqfs_grab(file);
+	m->cmp = sqfs_grab(cmp);
+	return m;
+}
+
+int sqfs_meta_reader_seek(sqfs_meta_reader_t *m, sqfs_u64 block_start,
+			  size_t offset)
+{
+	bool compressed;
+	sqfs_u16 header;
+	sqfs_u32 size;
+	sqfs_s32 ret;
+	int err;
+
+	if (block_start < m->start || block_start >= m->limit)
+		return SQFS_ERROR_OUT_OF_BOUNDS;
+
+	if (block_start == m->block_offset) {
+		if (offset >= m->data_used)
+			return SQFS_ERROR_OUT_OF_BOUNDS;
+
+		m->offset = offset;
+		return 0;
+	}
+
+	err = m->file->read_at(m->file, block_start, &header, 2);
+	if (err)
+		return err;
+
+	header = le16toh(header);
+	compressed = (header & 0x8000) == 0;
+	size = header & 0x7FFF;
+
+	if (size > sizeof(m->data))
+		return SQFS_ERROR_CORRUPTED;
+
+	if ((block_start + 2 + size) > m->limit)
+		return SQFS_ERROR_OUT_OF_BOUNDS;
+
+	err = m->file->read_at(m->file, block_start + 2, m->data, size);
+	if (err)
+		return err;
+
+	if (compressed) {
+		ret = m->cmp->do_block(m->cmp, m->data, size,
+				       m->scratch, sizeof(m->scratch));
+
+		if (ret < 0)
+			return ret;
+
+		memcpy(m->data, m->scratch, ret);
+		m->data_used = ret;
+	} else {
+		m->data_used = size;
+	}
+
+	if (offset >= m->data_used)
+		return SQFS_ERROR_OUT_OF_BOUNDS;
+
+	m->block_offset = block_start;
+	m->next_block = block_start + size + 2;
+	m->offset = offset;
+	return 0;
+}
+
+void sqfs_meta_reader_get_position(const sqfs_meta_reader_t *m,
+				   sqfs_u64 *block_start, size_t *offset)
+{
+	if (m->offset == m->data_used) {
+		*block_start = m->next_block;
+		*offset = 0;
+	} else {
+		*block_start = m->block_offset;
+		*offset = m->offset;
+	}
+}
+
+int sqfs_meta_reader_read(sqfs_meta_reader_t *m, void *data, size_t size)
+{
+	size_t diff;
+	int ret;
+
+	while (size != 0) {
+		diff = m->data_used - m->offset;
+
+		if (diff == 0) {
+			ret = sqfs_meta_reader_seek(m, m->next_block, 0);
+			if (ret)
+				return ret;
+			diff = m->data_used;
+		}
+
+		if (diff > size)
+			diff = size;
+
+		memcpy(data, m->data + m->offset, diff);
+
+		m->offset += diff;
+		data = (char *)data + diff;
+		size -= diff;
+	}
+
+	return 0;
+}