diff options
Diffstat (limited to 'lib/sqfs/super.c')
| -rw-r--r-- | lib/sqfs/super.c | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/lib/sqfs/super.c b/lib/sqfs/super.c new file mode 100644 index 0000000..b402496 --- /dev/null +++ b/lib/sqfs/super.c @@ -0,0 +1,95 @@ +/* SPDX-License-Identifier: GPL-3.0-or-later */ +#include "squashfs.h" +#include "util.h" + +#include <endian.h> +#include <string.h> +#include <unistd.h> +#include <stdio.h> + +int sqfs_super_init(sqfs_super_t *super, size_t block_size, uint32_t mtime, + E_SQFS_COMPRESSOR compressor) +{ + unsigned int i; + + if (block_size & (block_size - 1)) { + fputs("Block size must be a power of 2!\n", stderr); + return -1; + } + + if (block_size < 8192 || block_size >= (1 << 24)) { + fputs("Block size must be between 8k and 1M\n", stderr); + return -1; + } + + memset(super, 0, sizeof(*super)); + super->magic = SQFS_MAGIC; + super->modification_time = mtime; + super->block_size = block_size; + super->compression_id = compressor; + super->flags = SQFS_FLAG_NO_FRAGMENTS | SQFS_FLAG_NO_XATTRS; + super->version_major = SQFS_VERSION_MAJOR; + super->version_minor = SQFS_VERSION_MINOR; + super->bytes_used = sizeof(*super); + super->id_table_start = 0xFFFFFFFFFFFFFFFFUL; + super->xattr_id_table_start = 0xFFFFFFFFFFFFFFFFUL; + super->inode_table_start = 0xFFFFFFFFFFFFFFFFUL; + super->directory_table_start = 0xFFFFFFFFFFFFFFFFUL; + super->fragment_table_start = 0xFFFFFFFFFFFFFFFFUL; + super->export_table_start = 0xFFFFFFFFFFFFFFFFUL; + + for (i = block_size; i != 0x01; i >>= 1) + super->block_log += 1; + + return 0; +} + +int sqfs_super_write(sqfs_super_t *super, int fd) +{ + sqfs_super_t copy; + ssize_t ret; + + copy.magic = htole32(super->magic); + copy.inode_count = htole32(super->inode_count); + copy.modification_time = htole32(super->modification_time); + copy.block_size = htole32(super->block_size); + copy.fragment_entry_count = htole32(super->fragment_entry_count); + copy.compression_id = htole16(super->compression_id); + copy.block_log = htole16(super->block_log); + copy.flags = htole16(super->flags); + copy.id_count = htole16(super->id_count); + copy.version_major = htole16(super->version_major); + copy.version_minor = htole16(super->version_minor); + copy.root_inode_ref = htole64(super->root_inode_ref); + copy.bytes_used = htole64(super->bytes_used); + copy.id_table_start = htole64(super->id_table_start); + copy.xattr_id_table_start = htole64(super->xattr_id_table_start); + copy.inode_table_start = htole64(super->inode_table_start); + copy.directory_table_start = htole64(super->directory_table_start); + copy.fragment_table_start = htole64(super->fragment_table_start); + copy.export_table_start = htole64(super->export_table_start); + + if (lseek(fd, 0, SEEK_SET) == (off_t)-1) + goto fail_seek; + + ret = write_retry(fd, ©, sizeof(copy)); + + if (ret < 0) { + perror("squashfs writing super block"); + return -1; + } + + if ((size_t)ret < sizeof(copy)) { + fputs("squashfs writing super block: truncated write\n", + stderr); + return -1; + } + + if (lseek(fd, 0, SEEK_END) == (off_t)-1) + goto fail_seek; + + return 0; +fail_seek: + perror("squashfs writing super block: seek on output file"); + return -1; +} |