blob: c1997b65da97e9cda50dae99c47a2cce50763fd8 [file] [log] [blame]
/*
* Copyright (C) 2010 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.
*/
#include "ext4_utils.h"
#include "output_file.h"
#include "sparse_format.h"
#include "sparse_crc32.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/mman.h>
#include <unistd.h>
#include <fcntl.h>
#include <zlib.h>
#if defined(__APPLE__) && defined(__MACH__)
#define lseek64 lseek
#define off64_t off_t
#endif
#define SPARSE_HEADER_MAJOR_VER 1
#define SPARSE_HEADER_MINOR_VER 0
#define SPARSE_HEADER_LEN (sizeof(sparse_header_t))
#define CHUNK_HEADER_LEN (sizeof(chunk_header_t))
struct output_file_ops {
int (*seek)(struct output_file *, off64_t);
int (*write)(struct output_file *, u8 *, int);
void (*close)(struct output_file *);
};
struct output_file {
int fd;
gzFile gz_fd;
int sparse;
u64 cur_out_ptr;
u32 chunk_cnt;
u32 crc32;
struct output_file_ops *ops;
int use_crc;
};
static int file_seek(struct output_file *out, off64_t off)
{
off64_t ret;
ret = lseek64(out->fd, off, SEEK_SET);
if (ret < 0) {
error_errno("lseek64");
return -1;
}
return 0;
}
static int file_write(struct output_file *out, u8 *data, int len)
{
int ret;
ret = write(out->fd, data, len);
if (ret < 0) {
error_errno("write");
return -1;
} else if (ret < len) {
error("incomplete write");
return -1;
}
return 0;
}
static void file_close(struct output_file *out)
{
close(out->fd);
}
static struct output_file_ops file_ops = {
.seek = file_seek,
.write = file_write,
.close = file_close,
};
static int gz_file_seek(struct output_file *out, off64_t off)
{
off64_t ret;
ret = gzseek(out->gz_fd, off, SEEK_SET);
if (ret < 0) {
error_errno("gzseek");
return -1;
}
return 0;
}
static int gz_file_write(struct output_file *out, u8 *data, int len)
{
int ret;
ret = gzwrite(out->gz_fd, data, len);
if (ret < 0) {
error_errno("gzwrite");
return -1;
} else if (ret < len) {
error("incomplete gzwrite");
return -1;
}
return 0;
}
static void gz_file_close(struct output_file *out)
{
gzclose(out->gz_fd);
}
static struct output_file_ops gz_file_ops = {
.seek = gz_file_seek,
.write = gz_file_write,
.close = gz_file_close,
};
static sparse_header_t sparse_header = {
.magic = SPARSE_HEADER_MAGIC,
.major_version = SPARSE_HEADER_MAJOR_VER,
.minor_version = SPARSE_HEADER_MINOR_VER,
.file_hdr_sz = SPARSE_HEADER_LEN,
.chunk_hdr_sz = CHUNK_HEADER_LEN,
.blk_sz = 0,
.total_blks = 0,
.total_chunks = 0,
.image_checksum = 0
};
static u8 *zero_buf;
static int emit_skip_chunk(struct output_file *out, u64 skip_len)
{
chunk_header_t chunk_header;
int ret, chunk;
//DBG printf("skip chunk: 0x%llx bytes\n", skip_len);
if (skip_len % info.block_size) {
error("don't care size %llu is not a multiple of the block size %u",
skip_len, info.block_size);
return -1;
}
/* We are skipping data, so emit a don't care chunk. */
chunk_header.chunk_type = CHUNK_TYPE_DONT_CARE;
chunk_header.reserved1 = 0;
chunk_header.chunk_sz = skip_len / info.block_size;
chunk_header.total_sz = CHUNK_HEADER_LEN;
ret = out->ops->write(out, (u8 *)&chunk_header, sizeof(chunk_header));
if (ret < 0)
return -1;
out->cur_out_ptr += skip_len;
out->chunk_cnt++;
return 0;
}
static int write_chunk_raw(struct output_file *out, u64 off, u8 *data, int len)
{
chunk_header_t chunk_header;
int rnd_up_len, zero_len;
int ret;
/* We can assume that all the chunks to be written are in
* ascending order, block-size aligned, and non-overlapping.
* So, if the offset is less than the current output pointer,
* throw an error, and if there is a gap, emit a "don't care"
* chunk. The first write (of the super block) may not be
* blocksize aligned, so we need to deal with that too.
*/
//DBG printf("write chunk: offset 0x%llx, length 0x%x bytes\n", off, len);
if (off < out->cur_out_ptr) {
error("offset %llu is less than the current output offset %llu",
off, out->cur_out_ptr);
return -1;
}
if (off > out->cur_out_ptr) {
emit_skip_chunk(out, off - out->cur_out_ptr);
}
if (off % info.block_size) {
error("write chunk offset %llu is not a multiple of the block size %u",
off, info.block_size);
return -1;
}
if (off != out->cur_out_ptr) {
error("internal error, offset accounting screwy in write_chunk_raw()");
return -1;
}
/* Round up the file length to a multiple of the block size */
rnd_up_len = (len + (info.block_size - 1)) & (~(info.block_size -1));
zero_len = rnd_up_len - len;
/* Finally we can safely emit a chunk of data */
chunk_header.chunk_type = CHUNK_TYPE_RAW;
chunk_header.reserved1 = 0;
chunk_header.chunk_sz = rnd_up_len / info.block_size;
chunk_header.total_sz = CHUNK_HEADER_LEN + rnd_up_len;
ret = out->ops->write(out, (u8 *)&chunk_header, sizeof(chunk_header));
if (ret < 0)
return -1;
ret = out->ops->write(out, data, len);
if (ret < 0)
return -1;
if (zero_len) {
ret = out->ops->write(out, zero_buf, zero_len);
if (ret < 0)
return -1;
}
if (out->use_crc) {
out->crc32 = sparse_crc32(out->crc32, data, len);
if (zero_len)
out->crc32 = sparse_crc32(out->crc32, zero_buf, zero_len);
}
out->cur_out_ptr += rnd_up_len;
out->chunk_cnt++;
return 0;
}
void close_output_file(struct output_file *out)
{
int ret;
chunk_header_t chunk_header;
if (out->sparse) {
if (out->use_crc) {
chunk_header.chunk_type = CHUNK_TYPE_CRC32;
chunk_header.reserved1 = 0;
chunk_header.chunk_sz = 0;
chunk_header.total_sz = CHUNK_HEADER_LEN + 4;
out->ops->write(out, (u8 *)&chunk_header, sizeof(chunk_header));
out->ops->write(out, (u8 *)&out->crc32, 4);
out->chunk_cnt++;
}
if (out->chunk_cnt != sparse_header.total_chunks)
error("sparse chunk count did not match: %d %d", out->chunk_cnt,
sparse_header.total_chunks);
}
out->ops->close(out);
}
struct output_file *open_output_file(const char *filename, int gz, int sparse,
int chunks, int crc)
{
int ret;
struct output_file *out = malloc(sizeof(struct output_file));
if (!out) {
error_errno("malloc struct out");
return NULL;
}
zero_buf = malloc(info.block_size);
if (!zero_buf) {
error_errno("malloc zero_buf");
return NULL;
}
memset(zero_buf, '\0', info.block_size);
if (gz) {
out->ops = &gz_file_ops;
out->gz_fd = gzopen(filename, "wb9");
if (!out->gz_fd) {
error_errno("gzopen");
free(out);
return NULL;
}
} else {
if (strcmp(filename, "-")) {
out->fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0644);
if (out->fd < 0) {
error_errno("open");
free(out);
return NULL;
}
} else {
out->fd = STDOUT_FILENO;
}
out->ops = &file_ops;
}
out->sparse = sparse;
out->cur_out_ptr = 0ll;
out->chunk_cnt = 0;
/* Initialize the crc32 value */
out->crc32 = 0;
out->use_crc = crc;
if (out->sparse) {
sparse_header.blk_sz = info.block_size,
sparse_header.total_blks = info.len / info.block_size,
sparse_header.total_chunks = chunks;
if (out->use_crc)
sparse_header.total_chunks++;
ret = out->ops->write(out, (u8 *)&sparse_header, sizeof(sparse_header));
if (ret < 0)
return NULL;
}
return out;
}
void pad_output_file(struct output_file *out, u64 len)
{
int ret;
if (len > (u64) info.len) {
error("attempted to pad file %llu bytes past end of filesystem",
len - info.len);
return;
}
if (out->sparse) {
/* We need to emit a DONT_CARE chunk to pad out the file if the
* cur_out_ptr is not already at the end of the filesystem.
*/
if (len < out->cur_out_ptr) {
error("attempted to pad file %llu bytes less than the current output pointer",
out->cur_out_ptr - len);
return;
}
if (len > out->cur_out_ptr) {
emit_skip_chunk(out, len - out->cur_out_ptr);
}
} else {
//KEN TODO: Fixme. If the filesystem image needs no padding,
// this will overwrite the last byte in the file with 0
// The answer is to do accounting like the sparse image
// code does and know if there is already data there.
ret = out->ops->seek(out, len - 1);
if (ret < 0)
return;
ret = out->ops->write(out, (u8*)"", 1);
if (ret < 0)
return;
}
}
/* Write a contiguous region of data blocks from a memory buffer */
void write_data_block(struct output_file *out, u64 off, u8 *data, int len)
{
int ret;
if (off + len > (u64) info.len) {
error("attempted to write block %llu past end of filesystem",
off + len - info.len);
return;
}
if (out->sparse) {
write_chunk_raw(out, off, data, len);
} else {
ret = out->ops->seek(out, off);
if (ret < 0)
return;
ret = out->ops->write(out, data, len);
if (ret < 0)
return;
}
}
/* Write a contiguous region of data blocks from a file */
void write_data_file(struct output_file *out, u64 off, const char *file,
off64_t offset, int len)
{
int ret;
off64_t aligned_offset;
int aligned_diff;
if (off + len >= (u64) info.len) {
error("attempted to write block %llu past end of filesystem",
off + len - info.len);
return;
}
int file_fd = open(file, O_RDONLY);
if (file_fd < 0) {
error_errno("open");
return;
}
aligned_offset = offset & ~(4096 - 1);
aligned_diff = offset - aligned_offset;
u8 *data = mmap64(NULL, len + aligned_diff, PROT_READ, MAP_SHARED, file_fd,
aligned_offset);
if (data == MAP_FAILED) {
error_errno("mmap64");
close(file_fd);
return;
}
if (out->sparse) {
write_chunk_raw(out, off, data + aligned_diff, len);
} else {
ret = out->ops->seek(out, off);
if (ret < 0)
goto err;
ret = out->ops->write(out, data + aligned_diff, len);
if (ret < 0)
goto err;
}
munmap(data, len);
close(file_fd);
err:
munmap(data, len);
close(file_fd);
}