/*-
* Copyright 2003-2005 Colin Percival
* All rights reserved
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted providing that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#if 0
__FBSDID("$FreeBSD: src/usr.bin/bsdiff/bspatch/bspatch.c,v 1.1 2005/08/06 01:59:06 cperciva Exp $");
#endif
#include "bspatch.h"
#include <bzlib.h>
#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <algorithm>
#include <memory>
#include <limits>
#include <vector>
#include "buffer_file.h"
#include "extents.h"
#include "extents_file.h"
#include "file.h"
#include "file_interface.h"
#include "memory_file.h"
#include "sink_file.h"
namespace {
int64_t ParseInt64(const u_char* buf) {
int64_t y;
y = buf[7] & 0x7F;
y = y * 256;
y += buf[6];
y = y * 256;
y += buf[5];
y = y * 256;
y += buf[4];
y = y * 256;
y += buf[3];
y = y * 256;
y += buf[2];
y = y * 256;
y += buf[1];
y = y * 256;
y += buf[0];
if (buf[7] & 0x80)
y = -y;
return y;
}
bool ReadBZ2(bz_stream* stream, uint8_t* data, size_t size) {
stream->next_out = (char*)data;
while (size > 0) {
unsigned int read_size = std::min(
static_cast<size_t>(std::numeric_limits<unsigned int>::max()), size);
stream->avail_out = read_size;
int bz2err = BZ2_bzDecompress(stream);
if (bz2err != BZ_OK && bz2err != BZ_STREAM_END)
return false;
size -= read_size - stream->avail_out;
}
return true;
}
int ReadBZ2AndWriteAll(const std::unique_ptr<bsdiff::FileInterface>& file,
bz_stream* stream,
size_t size,
uint8_t* buf,
size_t buf_size) {
while (size > 0) {
size_t bytes_to_read = std::min(size, buf_size);
if (!ReadBZ2(stream, buf, bytes_to_read)) {
fprintf(stderr, "Failed to read bzip stream.\n");
return 2;
}
if (!WriteAll(file, buf, bytes_to_read)) {
perror("WriteAll() failed");
return 1;
}
size -= bytes_to_read;
}
return 0;
}
} // namespace
namespace bsdiff {
bool ReadAll(const std::unique_ptr<FileInterface>& file,
uint8_t* data,
size_t size) {
size_t offset = 0, read;
while (offset < size) {
if (!file->Read(data + offset, size - offset, &read) || read == 0)
return false;
offset += read;
}
return true;
}
bool WriteAll(const std::unique_ptr<FileInterface>& file,
const uint8_t* data,
size_t size) {
size_t offset = 0, written;
while (offset < size) {
if (!file->Write(data + offset, size - offset, &written) || written == 0)
return false;
offset += written;
}
return true;
}
bool IsOverlapping(const char* old_filename,
const char* new_filename,
const std::vector<ex_t>& old_extents,
const std::vector<ex_t>& new_extents) {
struct stat old_stat, new_stat;
if (stat(new_filename, &new_stat) == -1) {
if (errno == ENOENT)
return false;
fprintf(stderr, "Error stat the new file %s: %s\n", new_filename,
strerror(errno));
return true;
}
if (stat(old_filename, &old_stat) == -1) {
fprintf(stderr, "Error stat the old file %s: %s\n", old_filename,
strerror(errno));
return true;
}
if (old_stat.st_dev != new_stat.st_dev || old_stat.st_ino != new_stat.st_ino)
return false;
if (old_extents.empty() && new_extents.empty())
return true;
for (ex_t old_ex : old_extents)
for (ex_t new_ex : new_extents)
if (static_cast<uint64_t>(old_ex.off) < new_ex.off + new_ex.len &&
static_cast<uint64_t>(new_ex.off) < old_ex.off + old_ex.len)
return true;
return false;
}
// Patch |old_filename| with |patch_filename| and save it to |new_filename|.
// |old_extents| and |new_extents| are comma-separated lists of "offset:length"
// extents of |old_filename| and |new_filename|.
// Returns 0 on success, 1 on I/O error and 2 on data error.
int bspatch(const char* old_filename,
const char* new_filename,
const char* patch_filename,
const char* old_extents,
const char* new_extents) {
std::unique_ptr<FileInterface> patch_file =
File::FOpen(patch_filename, O_RDONLY);
if (!patch_file) {
fprintf(stderr, "Error opening the patch file %s: %s\n", patch_filename,
strerror(errno));
return 1;
}
uint64_t patch_size;
patch_file->GetSize(&patch_size);
std::vector<uint8_t> patch(patch_size);
if (!ReadAll(patch_file, patch.data(), patch_size)) {
fprintf(stderr, "Error reading the patch file %s: %s\n", patch_filename,
strerror(errno));
return 1;
}
patch_file.reset();
return bspatch(old_filename, new_filename, patch.data(), patch_size,
old_extents, new_extents);
}
// Patch |old_filename| with |patch_data| and save it to |new_filename|.
// |old_extents| and |new_extents| are comma-separated lists of "offset:length"
// extents of |old_filename| and |new_filename|.
// Returns 0 on success, 1 on I/O error and 2 on data error.
int bspatch(const char* old_filename,
const char* new_filename,
const uint8_t* patch_data,
size_t patch_size,
const char* old_extents,
const char* new_extents) {
int using_extents = (old_extents != NULL || new_extents != NULL);
// Open input file for reading.
std::unique_ptr<FileInterface> old_file = File::FOpen(old_filename, O_RDONLY);
if (!old_file) {
fprintf(stderr, "Error opening the old file %s: %s\n", old_filename,
strerror(errno));
return 1;
}
std::vector<ex_t> parsed_old_extents;
if (using_extents) {
if (!ParseExtentStr(old_extents, &parsed_old_extents)) {
fprintf(stderr, "Error parsing the old extents\n");
return 2;
}
old_file.reset(new ExtentsFile(std::move(old_file), parsed_old_extents));
}
// Open output file for writing.
std::unique_ptr<FileInterface> new_file =
File::FOpen(new_filename, O_CREAT | O_WRONLY);
if (!new_file) {
fprintf(stderr, "Error opening the new file %s: %s\n", new_filename,
strerror(errno));
return 1;
}
std::vector<ex_t> parsed_new_extents;
if (using_extents) {
if (!ParseExtentStr(new_extents, &parsed_new_extents)) {
fprintf(stderr, "Error parsing the new extents\n");
return 2;
}
new_file.reset(new ExtentsFile(std::move(new_file), parsed_new_extents));
}
if (IsOverlapping(old_filename, new_filename, parsed_old_extents,
parsed_new_extents)) {
// New and old file is overlapping, we can not stream output to new file,
// cache it in a buffer and write to the file at the end.
uint64_t newsize = ParseInt64(patch_data + 24);
new_file.reset(new BufferFile(std::move(new_file), newsize));
}
return bspatch(old_file, new_file, patch_data, patch_size);
}
// Patch |old_data| with |patch_data| and save it by calling sink function.
// Returns 0 on success, 1 on I/O error and 2 on data error.
int bspatch(const uint8_t* old_data,
size_t old_size,
const uint8_t* patch_data,
size_t patch_size,
const sink_func& sink) {
std::unique_ptr<FileInterface> old_file(new MemoryFile(old_data, old_size));
std::unique_ptr<FileInterface> new_file(new SinkFile(sink));
return bspatch(old_file, new_file, patch_data, patch_size);
}
// Patch |old_file| with |patch_data| and save it to |new_file|.
// Returns 0 on success, 1 on I/O error and 2 on data error.
int bspatch(const std::unique_ptr<FileInterface>& old_file,
const std::unique_ptr<FileInterface>& new_file,
const uint8_t* patch_data,
size_t patch_size) {
int bz2err;
u_char buf[8];
off_t ctrl[3];
// File format:
// 0 8 "BSDIFF40"
// 8 8 X
// 16 8 Y
// 24 8 sizeof(new_filename)
// 32 X bzip2(control block)
// 32+X Y bzip2(diff block)
// 32+X+Y ??? bzip2(extra block)
// with control block a set of triples (x,y,z) meaning "add x bytes
// from oldfile to x bytes from the diff block; copy y bytes from the
// extra block; seek forwards in oldfile by z bytes".
// Check for appropriate magic.
if (memcmp(patch_data, "BSDIFF40", 8) != 0) {
fprintf(stderr, "Not a bsdiff patch.\n");
return 2;
}
// Read lengths from header.
uint64_t oldsize, newsize;
int64_t ctrl_len = ParseInt64(patch_data + 8);
int64_t data_len = ParseInt64(patch_data + 16);
int64_t signed_newsize = ParseInt64(patch_data + 24);
newsize = signed_newsize;
if ((ctrl_len < 0) || (data_len < 0) || (signed_newsize < 0) ||
(32 + ctrl_len + data_len > static_cast<int64_t>(patch_size))) {
fprintf(stderr, "Corrupt patch.\n");
return 2;
}
bz_stream cstream;
cstream.next_in = (char*)patch_data + 32;
cstream.avail_in = ctrl_len;
cstream.bzalloc = nullptr;
cstream.bzfree = nullptr;
cstream.opaque = nullptr;
if ((bz2err = BZ2_bzDecompressInit(&cstream, 0, 0)) != BZ_OK) {
fprintf(stderr, "Failed to bzinit control stream (%d)\n", bz2err);
return 2;
}
bz_stream dstream;
dstream.next_in = (char*)patch_data + 32 + ctrl_len;
dstream.avail_in = data_len;
dstream.bzalloc = nullptr;
dstream.bzfree = nullptr;
dstream.opaque = nullptr;
if ((bz2err = BZ2_bzDecompressInit(&dstream, 0, 0)) != BZ_OK) {
fprintf(stderr, "Failed to bzinit diff stream (%d)\n", bz2err);
return 2;
}
bz_stream estream;
estream.next_in = (char*)patch_data + 32 + ctrl_len + data_len;
estream.avail_in = patch_size - (32 + ctrl_len + data_len);
estream.bzalloc = nullptr;
estream.bzfree = nullptr;
estream.opaque = nullptr;
if ((bz2err = BZ2_bzDecompressInit(&estream, 0, 0)) != BZ_OK) {
fprintf(stderr, "Failed to bzinit extra stream (%d)\n", bz2err);
return 2;
}
uint64_t old_file_pos = 0;
if (!old_file->GetSize(&oldsize)) {
fprintf(stderr, "Cannot obtain the size of old file.\n");
return 1;
}
// The oldpos can be negative, but the new pos is only incremented linearly.
int64_t oldpos = 0;
uint64_t newpos = 0;
std::vector<uint8_t> old_buf(1024 * 1024), new_buf(1024 * 1024);
while (newpos < newsize) {
int64_t i;
// Read control data.
for (i = 0; i <= 2; i++) {
if (!ReadBZ2(&cstream, buf, 8)) {
fprintf(stderr, "Failed to read control stream.\n");
return 2;
}
ctrl[i] = ParseInt64(buf);
}
// Sanity-check.
if (ctrl[0] < 0 || ctrl[1] < 0) {
fprintf(stderr, "Corrupt patch.\n");
return 2;
}
// Sanity-check.
if (newpos + ctrl[0] > newsize) {
fprintf(stderr, "Corrupt patch.\n");
return 2;
}
int ret = 0;
// Add old data to diff string. It is enough to fseek once, at
// the beginning of the sequence, to avoid unnecessary overhead.
if ((i = oldpos) < 0) {
// Write diff block directly to new file without adding old data,
// because we will skip part where |oldpos| < 0.
ret = ReadBZ2AndWriteAll(new_file, &dstream, -i, new_buf.data(),
new_buf.size());
if (ret)
return ret;
i = 0;
}
// We just checked that |i| is not negative.
if (static_cast<uint64_t>(i) != old_file_pos && !old_file->Seek(i)) {
fprintf(stderr, "Error seeking input file to offset %" PRId64 ": %s\n", i,
strerror(errno));
return 1;
}
if ((old_file_pos = oldpos + ctrl[0]) > oldsize)
old_file_pos = oldsize;
size_t chunk_size = old_file_pos - i;
while (chunk_size > 0) {
size_t read_bytes;
size_t bytes_to_read = std::min(chunk_size, old_buf.size());
if (!old_file->Read(old_buf.data(), bytes_to_read, &read_bytes)) {
perror("Error reading from input file");
return 1;
}
if (!read_bytes) {
fprintf(stderr, "EOF reached while reading from input file.\n");
return 2;
}
// Read same amount of bytes from diff block
if (!ReadBZ2(&dstream, new_buf.data(), read_bytes)) {
fprintf(stderr, "Failed to read diff stream.\n");
return 2;
}
// new_buf already has data from diff block, adds old data to it.
for (size_t k = 0; k < read_bytes; k++)
new_buf[k] += old_buf[k];
if (!WriteAll(new_file, new_buf.data(), read_bytes)) {
perror("Error writing to new file");
return 1;
}
chunk_size -= read_bytes;
}
// Adjust pointers.
newpos += ctrl[0];
oldpos += ctrl[0];
if (oldpos > static_cast<int64_t>(oldsize)) {
// Write diff block directly to new file without adding old data,
// because we skipped part where |oldpos| > oldsize.
ret = ReadBZ2AndWriteAll(new_file, &dstream, oldpos - oldsize,
new_buf.data(), new_buf.size());
if (ret)
return ret;
}
// Sanity-check.
if (newpos + ctrl[1] > newsize) {
fprintf(stderr, "Corrupt patch.\n");
return 2;
}
// Read extra block.
ret = ReadBZ2AndWriteAll(new_file, &estream, ctrl[1], new_buf.data(),
new_buf.size());
if (ret)
return ret;
// Adjust pointers.
newpos += ctrl[1];
oldpos += ctrl[2];
}
// Close input file.
old_file->Close();
// Clean up the bzip2 reads.
BZ2_bzDecompressEnd(&cstream);
BZ2_bzDecompressEnd(&dstream);
BZ2_bzDecompressEnd(&estream);
if (!new_file->Close()) {
perror("Error closing new file");
return 1;
}
return 0;
}
} // namespace bsdiff