diff options
Diffstat (limited to 'libsparse/sparse_read.c')
| -rw-r--r-- | libsparse/sparse_read.c | 509 |
1 files changed, 509 insertions, 0 deletions
diff --git a/libsparse/sparse_read.c b/libsparse/sparse_read.c new file mode 100644 index 0000000..704bcfa --- /dev/null +++ b/libsparse/sparse_read.c @@ -0,0 +1,509 @@ +/* + * Copyright (C) 2012 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#define _GNU_SOURCE +#define _FILE_OFFSET_BITS 64 +#define _LARGEFILE64_SOURCE 1 + +#include <fcntl.h> +#include <stdarg.h> +#include <stdbool.h> +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +#include <sparse/sparse.h> + +#include "sparse_crc32.h" +#include "sparse_file.h" +#include "sparse_format.h" + +#if defined(__APPLE__) && defined(__MACH__) +#define lseek64 lseek +#define off64_t off_t +#endif + +#define SPARSE_HEADER_MAJOR_VER 1 +#define SPARSE_HEADER_LEN (sizeof(sparse_header_t)) +#define CHUNK_HEADER_LEN (sizeof(chunk_header_t)) + +#define COPY_BUF_SIZE (1024U*1024U) +static char *copybuf; + +#define min(a, b) \ + ({ typeof(a) _a = (a); typeof(b) _b = (b); (_a < _b) ? _a : _b; }) + +static void verbose_error(bool verbose, int err, const char *fmt, ...) +{ + char *s = ""; + char *at = ""; + if (fmt) { + va_list argp; + int size; + + va_start(argp, fmt); + size = vsnprintf(NULL, 0, fmt, argp); + va_end(argp); + + if (size < 0) { + return; + } + + at = malloc(size + 1); + if (at == NULL) { + return; + } + + va_start(argp, fmt); + vsnprintf(at, size, fmt, argp); + va_end(argp); + at[size] = 0; + s = " at "; + } + if (verbose) { +#ifndef USE_MINGW + if (err == -EOVERFLOW) { + sparse_print_verbose("EOF while reading file%s%s\n", s, at); + } else +#endif + if (err == -EINVAL) { + sparse_print_verbose("Invalid sparse file format%s%s\n", s, at); + } else if (err == -ENOMEM) { + sparse_print_verbose("Failed allocation while reading file%s%s\n", + s, at); + } else { + sparse_print_verbose("Unknown error %d%s%s\n", err, s, at); + } + } + if (fmt) { + free(at); + } +} + +static int process_raw_chunk(struct sparse_file *s, unsigned int chunk_size, + int fd, int64_t offset, unsigned int blocks, unsigned int block, + uint32_t *crc32) +{ + int ret; + int chunk; + unsigned int len = blocks * s->block_size; + + if (chunk_size % s->block_size != 0) { + return -EINVAL; + } + + if (chunk_size / s->block_size != blocks) { + return -EINVAL; + } + + ret = sparse_file_add_fd(s, fd, offset, len, block); + if (ret < 0) { + return ret; + } + + if (crc32) { + while (len) { + chunk = min(len, COPY_BUF_SIZE); + ret = read_all(fd, copybuf, chunk); + if (ret < 0) { + return ret; + } + *crc32 = sparse_crc32(*crc32, copybuf, chunk); + len -= chunk; + } + } else { + lseek64(fd, len, SEEK_CUR); + } + + return 0; +} + +static int process_fill_chunk(struct sparse_file *s, unsigned int chunk_size, + int fd, unsigned int blocks, unsigned int block, uint32_t *crc32) +{ + int ret; + int chunk; + int64_t len = (int64_t)blocks * s->block_size; + uint32_t fill_val; + uint32_t *fillbuf; + unsigned int i; + + if (chunk_size != sizeof(fill_val)) { + return -EINVAL; + } + + ret = read_all(fd, &fill_val, sizeof(fill_val)); + if (ret < 0) { + return ret; + } + + ret = sparse_file_add_fill(s, fill_val, len, block); + if (ret < 0) { + return ret; + } + + if (crc32) { + /* Fill copy_buf with the fill value */ + fillbuf = (uint32_t *)copybuf; + for (i = 0; i < (COPY_BUF_SIZE / sizeof(fill_val)); i++) { + fillbuf[i] = fill_val; + } + + while (len) { + chunk = min(len, COPY_BUF_SIZE); + *crc32 = sparse_crc32(*crc32, copybuf, chunk); + len -= chunk; + } + } + + return 0; +} + +static int process_skip_chunk(struct sparse_file *s, unsigned int chunk_size, + int fd, unsigned int blocks, unsigned int block, uint32_t *crc32) +{ + int ret; + int chunk; + int64_t len = (int64_t)blocks * s->block_size; + uint32_t fill_val; + uint32_t *fillbuf; + unsigned int i; + + if (chunk_size != 0) { + return -EINVAL; + } + + if (crc32) { + memset(copybuf, 0, COPY_BUF_SIZE); + + while (len) { + chunk = min(len, COPY_BUF_SIZE); + *crc32 = sparse_crc32(*crc32, copybuf, chunk); + len -= chunk; + } + } + + return 0; +} + +static int process_crc32_chunk(int fd, unsigned int chunk_size, uint32_t crc32) +{ + uint32_t file_crc32; + int ret; + + if (chunk_size != sizeof(file_crc32)) { + return -EINVAL; + } + + ret = read_all(fd, &file_crc32, sizeof(file_crc32)); + if (ret < 0) { + return ret; + } + + if (file_crc32 != crc32) { + return -EINVAL; + } + + return 0; +} + +static int process_chunk(struct sparse_file *s, int fd, off64_t offset, + unsigned int chunk_hdr_sz, chunk_header_t *chunk_header, + unsigned int cur_block, uint32_t *crc_ptr) +{ + int ret; + unsigned int chunk_data_size; + + chunk_data_size = chunk_header->total_sz - chunk_hdr_sz; + + switch (chunk_header->chunk_type) { + case CHUNK_TYPE_RAW: + ret = process_raw_chunk(s, chunk_data_size, fd, offset, + chunk_header->chunk_sz, cur_block, crc_ptr); + if (ret < 0) { + verbose_error(s->verbose, ret, "data block at %lld", offset); + return ret; + } + return chunk_header->chunk_sz; + case CHUNK_TYPE_FILL: + ret = process_fill_chunk(s, chunk_data_size, fd, + chunk_header->chunk_sz, cur_block, crc_ptr); + if (ret < 0) { + verbose_error(s->verbose, ret, "fill block at %lld", offset); + return ret; + } + return chunk_header->chunk_sz; + case CHUNK_TYPE_DONT_CARE: + ret = process_skip_chunk(s, chunk_data_size, fd, + chunk_header->chunk_sz, cur_block, crc_ptr); + if (chunk_data_size != 0) { + if (ret < 0) { + verbose_error(s->verbose, ret, "skip block at %lld", offset); + return ret; + } + } + return chunk_header->chunk_sz; + case CHUNK_TYPE_CRC32: + ret = process_crc32_chunk(fd, chunk_data_size, *crc_ptr); + if (ret < 0) { + verbose_error(s->verbose, -EINVAL, "crc block at %lld", + offset); + return ret; + } + return 0; + default: + verbose_error(s->verbose, -EINVAL, "unknown block %04X at %lld", + chunk_header->chunk_type, offset); + } + + return 0; +} + +static int sparse_file_read_sparse(struct sparse_file *s, int fd, bool crc) +{ + int ret; + unsigned int i; + sparse_header_t sparse_header; + chunk_header_t chunk_header; + uint32_t crc32 = 0; + uint32_t *crc_ptr = 0; + unsigned int cur_block = 0; + off64_t offset; + + if (!copybuf) { + copybuf = malloc(COPY_BUF_SIZE); + } + + if (!copybuf) { + return -ENOMEM; + } + + if (crc) { + crc_ptr = &crc32; + } + + ret = read_all(fd, &sparse_header, sizeof(sparse_header)); + if (ret < 0) { + return ret; + } + + if (sparse_header.magic != SPARSE_HEADER_MAGIC) { + return -EINVAL; + } + + if (sparse_header.major_version != SPARSE_HEADER_MAJOR_VER) { + return -EINVAL; + } + + if (sparse_header.file_hdr_sz < SPARSE_HEADER_LEN) { + return -EINVAL; + } + + if (sparse_header.chunk_hdr_sz < sizeof(chunk_header)) { + return -EINVAL; + } + + if (sparse_header.file_hdr_sz > SPARSE_HEADER_LEN) { + /* Skip the remaining bytes in a header that is longer than + * we expected. + */ + lseek64(fd, sparse_header.file_hdr_sz - SPARSE_HEADER_LEN, SEEK_CUR); + } + + for (i = 0; i < sparse_header.total_chunks; i++) { + ret = read_all(fd, &chunk_header, sizeof(chunk_header)); + if (ret < 0) { + return ret; + } + + if (sparse_header.chunk_hdr_sz > CHUNK_HEADER_LEN) { + /* Skip the remaining bytes in a header that is longer than + * we expected. + */ + lseek64(fd, sparse_header.chunk_hdr_sz - CHUNK_HEADER_LEN, SEEK_CUR); + } + + offset = lseek64(fd, 0, SEEK_CUR); + + ret = process_chunk(s, fd, offset, sparse_header.chunk_hdr_sz, &chunk_header, + cur_block, crc_ptr); + if (ret < 0) { + return ret; + } + + cur_block += ret; + } + + if (sparse_header.total_blks != cur_block) { + return -EINVAL; + } + + return 0; +} + +static int sparse_file_read_normal(struct sparse_file *s, int fd) +{ + int ret; + uint32_t *buf = malloc(s->block_size); + unsigned int block = 0; + int64_t remain = s->len; + int64_t offset = 0; + unsigned int to_read; + char *ptr; + unsigned int i; + bool sparse_block; + + if (!buf) { + return -ENOMEM; + } + + while (remain > 0) { + to_read = min(remain, s->block_size); + ret = read_all(fd, buf, to_read); + if (ret < 0) { + error("failed to read sparse file"); + return ret; + } + + if (to_read == s->block_size) { + sparse_block = true; + for (i = 1; i < s->block_size / sizeof(uint32_t); i++) { + if (buf[0] != buf[i]) { + sparse_block = false; + break; + } + } + } else { + sparse_block = false; + } + + if (sparse_block) { + /* TODO: add flag to use skip instead of fill for buf[0] == 0 */ + sparse_file_add_fill(s, buf[0], to_read, block); + } else { + sparse_file_add_fd(s, fd, offset, to_read, block); + } + + remain -= to_read; + offset += to_read; + block++; + } + + return 0; +} + +int sparse_file_read(struct sparse_file *s, int fd, bool sparse, bool crc) +{ + if (crc && !sparse) { + return -EINVAL; + } + + if (sparse) { + return sparse_file_read_sparse(s, fd, crc); + } else { + return sparse_file_read_normal(s, fd); + } +} + +struct sparse_file *sparse_file_import(int fd, bool verbose, bool crc) +{ + int ret; + sparse_header_t sparse_header; + int64_t len; + struct sparse_file *s; + + ret = read_all(fd, &sparse_header, sizeof(sparse_header)); + if (ret < 0) { + verbose_error(verbose, ret, "header"); + return NULL; + } + + if (sparse_header.magic != SPARSE_HEADER_MAGIC) { + verbose_error(verbose, -EINVAL, "header magic"); + return NULL; + } + + if (sparse_header.major_version != SPARSE_HEADER_MAJOR_VER) { + verbose_error(verbose, -EINVAL, "header major version"); + return NULL; + } + + if (sparse_header.file_hdr_sz < SPARSE_HEADER_LEN) { + return NULL; + } + + if (sparse_header.chunk_hdr_sz < sizeof(chunk_header_t)) { + return NULL; + } + + len = (int64_t)sparse_header.total_blks * sparse_header.blk_sz; + s = sparse_file_new(sparse_header.blk_sz, len); + if (!s) { + verbose_error(verbose, -EINVAL, NULL); + return NULL; + } + + ret = lseek64(fd, 0, SEEK_SET); + if (ret < 0) { + verbose_error(verbose, ret, "seeking"); + sparse_file_destroy(s); + return NULL; + } + + s->verbose = verbose; + + ret = sparse_file_read(s, fd, true, crc); + if (ret < 0) { + sparse_file_destroy(s); + return NULL; + } + + return s; +} + +struct sparse_file *sparse_file_import_auto(int fd, bool crc) +{ + struct sparse_file *s; + int64_t len; + int ret; + + s = sparse_file_import(fd, true, crc); + if (s) { + return s; + } + + len = lseek64(fd, 0, SEEK_END); + if (len < 0) { + return NULL; + } + + lseek64(fd, 0, SEEK_SET); + + s = sparse_file_new(4096, len); + if (!s) { + return NULL; + } + + ret = sparse_file_read_normal(s, fd); + if (ret < 0) { + sparse_file_destroy(s); + return NULL; + } + + return s; +} |