From 1d15ee609baf00459571b8d549bdd467dffa2b02 Mon Sep 17 00:00:00 2001 From: David Oberhollenzer Date: Thu, 23 Jan 2020 22:59:59 +0100 Subject: Add a fragment table primitive to libsquashfs Signed-off-by: David Oberhollenzer --- lib/sqfs/frag_table.c | 195 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 195 insertions(+) create mode 100644 lib/sqfs/frag_table.c (limited to 'lib/sqfs/frag_table.c') diff --git a/lib/sqfs/frag_table.c b/lib/sqfs/frag_table.c new file mode 100644 index 0000000..3373a3c --- /dev/null +++ b/lib/sqfs/frag_table.c @@ -0,0 +1,195 @@ +/* SPDX-License-Identifier: LGPL-3.0-or-later */ +/* + * frag_table.c + * + * Copyright (C) 2019 David Oberhollenzer + */ +#define SQFS_BUILDING_DLL +#include "config.h" + +#include "sqfs/frag_table.h" +#include "sqfs/super.h" +#include "sqfs/table.h" +#include "sqfs/error.h" +#include "sqfs/block.h" +#include "compat.h" + +#include +#include + +struct sqfs_frag_table_t { + size_t capacity; + size_t used; + sqfs_fragment_t *table; +}; + +sqfs_frag_table_t *sqfs_frag_table_create(sqfs_u32 flags) +{ + sqfs_frag_table_t *tbl; + + if (flags != 0) + return NULL; + + tbl = calloc(1, sizeof(*tbl)); + if (tbl == NULL) + return NULL; + + return tbl; +} + +void sqfs_frag_table_destroy(sqfs_frag_table_t *tbl) +{ + free(tbl->table); + free(tbl); +} + +int sqfs_frag_table_read(sqfs_frag_table_t *tbl, sqfs_file_t *file, + const sqfs_super_t *super, sqfs_compressor_t *cmp) +{ + sqfs_u64 location, lower, upper; + void *raw = NULL; + size_t size; + int err; + + free(tbl->table); + tbl->table = NULL; + tbl->capacity = 0; + tbl->used = 0; + + if (super->flags & SQFS_FLAG_NO_FRAGMENTS) + return 0; + + if (super->fragment_table_start == 0xFFFFFFFFFFFFFFFFUL) + return 0; + + if (super->fragment_entry_count == 0) + return 0; + + if (super->fragment_table_start >= super->bytes_used) + return SQFS_ERROR_OUT_OF_BOUNDS; + + /* location must be after inode & directory table, + but before the ID table */ + if (super->fragment_table_start < super->directory_table_start) + return SQFS_ERROR_CORRUPTED; + + if (super->fragment_table_start >= super->id_table_start) + return SQFS_ERROR_CORRUPTED; + + location = super->fragment_table_start; + lower = super->directory_table_start; + upper = super->id_table_start; + + if (super->export_table_start < super->id_table_start) + upper = super->export_table_start; + + if (SZ_MUL_OV(super->fragment_entry_count, sizeof(sqfs_fragment_t), + &size)) { + return SQFS_ERROR_OVERFLOW; + } + + err = sqfs_read_table(file, cmp, size, location, lower, upper, &raw); + if (err) { + free(raw); + return err; + } + + tbl->table = raw; + tbl->capacity = super->fragment_entry_count; + tbl->used = super->fragment_entry_count; + return 0; +} + +int sqfs_frag_table_write(sqfs_frag_table_t *tbl, sqfs_file_t *file, + sqfs_super_t *super, sqfs_compressor_t *cmp) +{ + size_t i; + int err; + + if (tbl->used == 0) { + super->fragment_table_start = 0xFFFFFFFFFFFFFFFF; + super->flags |= SQFS_FLAG_NO_FRAGMENTS; + super->flags &= ~SQFS_FLAG_ALWAYS_FRAGMENTS; + super->flags &= ~SQFS_FLAG_UNCOMPRESSED_FRAGMENTS; + return 0; + } + + err = sqfs_write_table(file, cmp, tbl->table, + sizeof(tbl->table[0]) * tbl->used, + &super->fragment_table_start); + if (err) + return err; + + super->fragment_entry_count = tbl->used; + super->flags &= ~SQFS_FLAG_NO_FRAGMENTS; + super->flags |= SQFS_FLAG_ALWAYS_FRAGMENTS; + super->flags |= SQFS_FLAG_UNCOMPRESSED_FRAGMENTS; + + for (i = 0; i < tbl->used; ++i) { + if (SQFS_IS_BLOCK_COMPRESSED(le32toh(tbl->table[i].size))) { + super->flags &= ~SQFS_FLAG_UNCOMPRESSED_FRAGMENTS; + break; + } + } + + return 0; +} + +int sqfs_frag_table_lookup(sqfs_frag_table_t *tbl, sqfs_u32 index, + sqfs_fragment_t *out) +{ + if (index >= tbl->used) + return SQFS_ERROR_OUT_OF_BOUNDS; + + out->start_offset = le64toh(tbl->table[index].start_offset); + out->size = le32toh(tbl->table[index].size); + out->pad0 = le32toh(tbl->table[index].pad0); + return 0; +} + +int sqfs_frag_table_append(sqfs_frag_table_t *tbl, sqfs_u64 location, + sqfs_u32 size, sqfs_u32 *index) +{ + size_t new_sz, total; + void *new; + + if (tbl->used == tbl->capacity) { + new_sz = tbl->capacity ? tbl->capacity * 2 : 128; + + if (SZ_MUL_OV(new_sz, sizeof(tbl->table[0]), &total)) + return SQFS_ERROR_OVERFLOW; + + new = realloc(tbl->table, total); + if (new == NULL) + return SQFS_ERROR_ALLOC; + + tbl->capacity = new_sz; + tbl->table = new; + } + + if (index != NULL) + *index = tbl->used; + + memset(tbl->table + tbl->used, 0, sizeof(tbl->table[0])); + tbl->table[tbl->used].start_offset = htole64(location); + tbl->table[tbl->used].size = htole32(size); + + tbl->used += 1; + return 0; +} + +int sqfs_frag_table_set(sqfs_frag_table_t *tbl, sqfs_u32 index, + sqfs_u64 location, sqfs_u32 size) +{ + if (index >= tbl->used) + return SQFS_ERROR_OUT_OF_BOUNDS; + + tbl->table[index].start_offset = htole64(location); + tbl->table[index].size = htole32(size); + return 0; +} + +size_t sqfs_frag_table_get_size(sqfs_frag_table_t *tbl) +{ + return tbl->used; +} -- cgit v1.2.3