diff options
Diffstat (limited to 'lib/sqfs')
| -rw-r--r-- | lib/sqfs/read_inode.c | 316 |
1 files changed, 316 insertions, 0 deletions
diff --git a/lib/sqfs/read_inode.c b/lib/sqfs/read_inode.c new file mode 100644 index 0000000..71b3a54 --- /dev/null +++ b/lib/sqfs/read_inode.c @@ -0,0 +1,316 @@ +/* SPDX-License-Identifier: GPL-3.0-or-later */ +#include "meta_reader.h" + +#include <sys/stat.h> +#include <stdlib.h> +#include <stdio.h> + +#define SWAB16(x) x = le16toh(x) +#define SWAB32(x) x = le32toh(x) +#define SWAB64(x) x = le64toh(x) + +static int check_mode(sqfs_inode_t *inode) +{ + switch (inode->mode & S_IFMT) { + case S_IFSOCK: + if (inode->type != SQFS_INODE_SOCKET && + inode->type != SQFS_INODE_EXT_SOCKET) { + goto fail_mismatch; + } + break; + case S_IFLNK: + if (inode->type != SQFS_INODE_SLINK && + inode->type != SQFS_INODE_EXT_SLINK) { + goto fail_mismatch; + } + break; + case S_IFREG: + if (inode->type != SQFS_INODE_FILE && + inode->type != SQFS_INODE_EXT_FILE) { + goto fail_mismatch; + } + break; + case S_IFBLK: + if (inode->type != SQFS_INODE_BDEV && + inode->type != SQFS_INODE_EXT_BDEV) { + goto fail_mismatch; + } + break; + case S_IFDIR: + if (inode->type != SQFS_INODE_DIR && + inode->type != SQFS_INODE_EXT_DIR) { + goto fail_mismatch; + } + break; + case S_IFCHR: + if (inode->type != SQFS_INODE_CDEV && + inode->type != SQFS_INODE_EXT_CDEV) { + goto fail_mismatch; + } + break; + case S_IFIFO: + if (inode->type != SQFS_INODE_FIFO && + inode->type != SQFS_INODE_EXT_FIFO) { + goto fail_mismatch; + } + break; + default: + fputs("Found inode with unknown file mode\n", stderr); + return -1; + } + + return 0; +fail_mismatch: + fputs("Found inode where type does not match mode\n", stderr); + return -1; +} + +static sqfs_inode_generic_t *read_inode_file(meta_reader_t *ir, + sqfs_inode_t *base, + size_t block_size) +{ + sqfs_inode_generic_t *out; + sqfs_inode_file_t file; + size_t i, count; + + if (meta_reader_read(ir, &file, sizeof(file))) + return NULL; + + SWAB32(file.blocks_start); + SWAB32(file.fragment_index); + SWAB32(file.fragment_offset); + SWAB32(file.file_size); + + count = file.file_size / block_size; + + out = calloc(1, sizeof(*out) + count * sizeof(uint32_t)); + if (out == NULL) { + perror("reading extended file inode"); + return NULL; + } + + out->base = *base; + out->data.file = file; + out->block_sizes = (uint32_t *)out->extra; + + if (meta_reader_read(ir, out->block_sizes, count * sizeof(uint32_t))) { + free(out); + return NULL; + } + + for (i = 0; i < count; ++i) + SWAB32(out->block_sizes[i]); + + return out; +} + +static sqfs_inode_generic_t *read_inode_file_ext(meta_reader_t *ir, + sqfs_inode_t *base, + size_t block_size) +{ + sqfs_inode_file_ext_t file; + sqfs_inode_generic_t *out; + size_t i, count; + + if (meta_reader_read(ir, &file, sizeof(file))) + return NULL; + + SWAB64(file.blocks_start); + SWAB64(file.file_size); + SWAB64(file.sparse); + SWAB32(file.nlink); + SWAB32(file.fragment_idx); + SWAB32(file.fragment_offset); + SWAB32(file.xattr_idx); + + count = file.file_size / block_size; + + out = calloc(1, sizeof(*out) + count * sizeof(uint32_t)); + if (out == NULL) { + perror("reading extended file inode"); + return NULL; + } + + out->base = *base; + out->data.file_ext = file; + out->block_sizes = (uint32_t *)out->extra; + + if (meta_reader_read(ir, out->block_sizes, count * sizeof(uint32_t))) { + free(out); + return NULL; + } + + for (i = 0; i < count; ++i) + SWAB32(out->block_sizes[i]); + + return out; +} + +static sqfs_inode_generic_t *read_inode_slink(meta_reader_t *ir, + sqfs_inode_t *base) +{ + sqfs_inode_generic_t *out; + sqfs_inode_slink_t slink; + + if (meta_reader_read(ir, &slink, sizeof(slink))) + return NULL; + + SWAB32(slink.nlink); + SWAB32(slink.target_size); + + out = calloc(1, sizeof(*out) + slink.target_size + 1); + if (out == NULL) { + perror("reading symlink inode"); + return NULL; + } + + out->slink_target = (char *)out->extra; + out->base = *base; + out->data.slink = slink; + + if (meta_reader_read(ir, out->slink_target, slink.target_size)) { + free(out); + return NULL; + } + + return out; +} + +static sqfs_inode_generic_t *read_inode_slink_ext(meta_reader_t *ir, + sqfs_inode_t *base) +{ + sqfs_inode_generic_t *out = read_inode_slink(ir, base); + uint32_t xattr; + + if (out != NULL) { + if (meta_reader_read(ir, &xattr, sizeof(xattr))) { + free(out); + return NULL; + } + + out->data.slink_ext.xattr_idx = le32toh(xattr); + } + return 0; +} + +sqfs_inode_generic_t *meta_reader_read_inode(meta_reader_t *ir, + sqfs_super_t *super, + uint64_t block_start, + size_t offset) +{ + sqfs_inode_generic_t *out; + sqfs_inode_t inode; + + /* read base inode */ + block_start += super->inode_table_start; + + if (meta_reader_seek(ir, block_start, offset)) + return NULL; + + if (meta_reader_read(ir, &inode, sizeof(inode))) + return NULL; + + SWAB16(inode.type); + SWAB16(inode.mode); + SWAB16(inode.uid_idx); + SWAB16(inode.gid_idx); + SWAB32(inode.mod_time); + SWAB32(inode.inode_number); + + if (check_mode(&inode)) + return NULL; + + /* inode types where the size is variable */ + switch (inode.type) { + case SQFS_INODE_FILE: + return read_inode_file(ir, &inode, super->block_size); + case SQFS_INODE_SLINK: + return read_inode_slink(ir, &inode); + case SQFS_INODE_EXT_FILE: + return read_inode_file_ext(ir, &inode, super->block_size); + case SQFS_INODE_EXT_SLINK: + return read_inode_slink_ext(ir, &inode); + default: + break; + } + + /* everything else */ + out = calloc(1, sizeof(*out)); + if (out == NULL) { + perror("reading symlink inode"); + return NULL; + } + + out->base = inode; + + switch (inode.type) { + case SQFS_INODE_DIR: + if (meta_reader_read(ir, &out->data.dir, + sizeof(out->data.dir))) { + goto fail_free; + } + SWAB32(out->data.dir.start_block); + SWAB32(out->data.dir.nlink); + SWAB16(out->data.dir.size); + SWAB16(out->data.dir.offset); + SWAB32(out->data.dir.parent_inode); + break; + case SQFS_INODE_BDEV: + case SQFS_INODE_CDEV: + if (meta_reader_read(ir, &out->data.dev, + sizeof(out->data.dev))) { + goto fail_free; + } + SWAB32(out->data.dev.nlink); + SWAB32(out->data.dev.devno); + break; + case SQFS_INODE_FIFO: + case SQFS_INODE_SOCKET: + if (meta_reader_read(ir, &out->data.ipc, + sizeof(out->data.ipc))) { + goto fail_free; + } + SWAB32(out->data.ipc.nlink); + break; + case SQFS_INODE_EXT_DIR: + if (meta_reader_read(ir, &out->data.dir_ext, + sizeof(out->data.dir_ext))) { + goto fail_free; + } + SWAB32(out->data.dir_ext.nlink); + SWAB32(out->data.dir_ext.size); + SWAB32(out->data.dir_ext.start_block); + SWAB32(out->data.dir_ext.parent_inode); + SWAB16(out->data.dir_ext.inodex_count); + SWAB16(out->data.dir_ext.offset); + SWAB32(out->data.dir_ext.xattr_idx); + break; + case SQFS_INODE_EXT_BDEV: + case SQFS_INODE_EXT_CDEV: + if (meta_reader_read(ir, &out->data.dev_ext, + sizeof(out->data.dev_ext))) { + goto fail_free; + } + SWAB32(out->data.dev_ext.nlink); + SWAB32(out->data.dev_ext.devno); + SWAB32(out->data.dev_ext.xattr_idx); + break; + case SQFS_INODE_EXT_FIFO: + case SQFS_INODE_EXT_SOCKET: + if (meta_reader_read(ir, &out->data.ipc_ext, + sizeof(out->data.ipc_ext))) { + goto fail_free; + } + SWAB32(out->data.ipc_ext.nlink); + SWAB32(out->data.ipc_ext.xattr_idx); + break; + default: + fputs("Unknown inode type found\n", stderr); + goto fail_free; + } + + return out; +fail_free: + free(out); + return NULL; +} |