/*-
* 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 <err.h>
#include <fcntl.h>
#include <inttypes.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <algorithm>
#include <memory>
#include <limits>
#include "extents.h"
#include "extents_file.h"
#include "file.h"
#include "file_interface.h"
namespace {
int64_t ParseInt64(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;
}
} // namespace
namespace bsdiff {
int bspatch(
const char* old_filename, const char* new_filename,
const char* patch_filename,
const char* old_extents, const char* new_extents) {
FILE* f, *cpf, *dpf, *epf;
BZFILE* cpfbz2, *dpfbz2, *epfbz2;
int cbz2err, dbz2err, ebz2err;
ssize_t bzctrllen, bzdatalen;
u_char header[32], buf[8];
u_char* new_buf;
off_t ctrl[3];
off_t lenread;
int using_extents = (old_extents != NULL || new_extents != NULL);
// Open patch file.
if ((f = fopen(patch_filename, "r")) == NULL)
err(1, "fopen(%s)", patch_filename);
// 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".
// Read header.
if (fread(header, 1, 32, f) < 32) {
if (feof(f))
errx(1, "Corrupt patch\n");
err(1, "fread(%s)", patch_filename);
}
// Check for appropriate magic.
if (memcmp(header, "BSDIFF40", 8) != 0)
errx(1, "Corrupt patch\n");
// Read lengths from header.
uint64_t oldsize, newsize;
bzctrllen = ParseInt64(header + 8);
bzdatalen = ParseInt64(header + 16);
int64_t signed_newsize = ParseInt64(header + 24);
newsize = signed_newsize;
if ((bzctrllen < 0) || (bzdatalen < 0) || (signed_newsize < 0))
errx(1, "Corrupt patch\n");
// Close patch file and re-open it via libbzip2 at the right places.
if (fclose(f))
err(1, "fclose(%s)", patch_filename);
if ((cpf = fopen(patch_filename, "r")) == NULL)
err(1, "fopen(%s)", patch_filename);
if (fseek(cpf, 32, SEEK_SET))
err(1, "fseeko(%s, %lld)", patch_filename, (long long)32);
if ((cpfbz2 = BZ2_bzReadOpen(&cbz2err, cpf, 0, 0, NULL, 0)) == NULL)
errx(1, "BZ2_bzReadOpen, bz2err = %d", cbz2err);
if ((dpf = fopen(patch_filename, "r")) == NULL)
err(1, "fopen(%s)", patch_filename);
if (fseek(dpf, 32 + bzctrllen, SEEK_SET))
err(1, "fseeko(%s, %lld)", patch_filename, (long long)(32 + bzctrllen));
if ((dpfbz2 = BZ2_bzReadOpen(&dbz2err, dpf, 0, 0, NULL, 0)) == NULL)
errx(1, "BZ2_bzReadOpen, bz2err = %d", dbz2err);
if ((epf = fopen(patch_filename, "r")) == NULL)
err(1, "fopen(%s)", patch_filename);
if (fseek(epf, 32 + bzctrllen + bzdatalen, SEEK_SET))
err(1, "fseeko(%s, %lld)", patch_filename,
(long long)(32 + bzctrllen + bzdatalen));
if ((epfbz2 = BZ2_bzReadOpen(&ebz2err, epf, 0, 0, NULL, 0)) == NULL)
errx(1, "BZ2_bzReadOpen, bz2err = %d", ebz2err);
// Open input file for reading.
std::unique_ptr<FileInterface> old_file = File::FOpen(old_filename, O_RDONLY);
if (!old_file)
err(1, "Error opening the old filename");
if (using_extents) {
std::vector<ex_t> parsed_old_extents;
if (!ParseExtentStr(old_extents, &parsed_old_extents))
errx(1, "Error parsing the old extents");
old_file.reset(new ExtentsFile(std::move(old_file), parsed_old_extents));
}
if (!old_file->GetSize(&oldsize))
err(1, "cannot obtain the size of %s", old_filename);
uint64_t old_file_pos = 0;
if ((new_buf = static_cast<u_char*>(malloc(newsize + 1))) == NULL)
err(1, NULL);
// The oldpos can be negative, but the new pos is only incremented linearly.
int64_t oldpos = 0;
uint64_t newpos = 0;
std::vector<u_char> old_buf(1024 * 1024);
while (newpos < newsize) {
int64_t i, j;
// Read control data.
for (i = 0; i <= 2; i++) {
lenread = BZ2_bzRead(&cbz2err, cpfbz2, buf, 8);
if ((lenread < 8) || ((cbz2err != BZ_OK) && (cbz2err != BZ_STREAM_END)))
errx(1, "Corrupt patch\n");
ctrl[i] = ParseInt64(buf);
};
// Sanity-check.
if (ctrl[0] < 0 || ctrl[1] < 0)
errx(1, "Corrupt patch\n");
// Sanity-check.
if (newpos + ctrl[0] > newsize)
errx(1, "Corrupt patch\n");
// Read diff string.
lenread = BZ2_bzRead(&dbz2err, dpfbz2, new_buf + newpos, ctrl[0]);
if ((lenread < ctrl[0]) ||
((dbz2err != BZ_OK) && (dbz2err != BZ_STREAM_END)))
errx(1, "Corrupt patch\n");
// Add old data to diff string. It is enough to fseek once, at
// the beginning of the sequence, to avoid unnecessary overhead.
j = newpos;
if ((i = oldpos) < 0) {
j -= i;
i = 0;
}
// We just checked that |i| is not negative.
if (static_cast<uint64_t>(i) != old_file_pos && !old_file->Seek(i))
err(1, "error seeking input file to offset %" PRId64, i);
if ((old_file_pos = oldpos + ctrl[0]) > oldsize)
old_file_pos = oldsize;
uint64_t chunk_size = old_file_pos - i;
while (chunk_size > 0) {
size_t read_bytes;
size_t bytes_to_read =
std::min(chunk_size, static_cast<uint64_t>(old_buf.size()));
if (!old_file->Read(old_buf.data(), bytes_to_read, &read_bytes))
err(1, "error reading from input file");
if (!read_bytes)
errx(1, "EOF reached while reading from input file");
// new_buf already has data from diff block, adds old data to it.
for (size_t k = 0; k < read_bytes; k++)
new_buf[j++] += old_buf[k];
chunk_size -= read_bytes;
}
// Adjust pointers.
newpos += ctrl[0];
oldpos += ctrl[0];
// Sanity-check.
if (newpos + ctrl[1] > newsize)
errx(1, "Corrupt patch\n");
// Read extra string.
lenread = BZ2_bzRead(&ebz2err, epfbz2, new_buf + newpos, ctrl[1]);
if ((lenread < ctrl[1]) ||
((ebz2err != BZ_OK) && (ebz2err != BZ_STREAM_END)))
errx(1, "Corrupt patch\n");
// Adjust pointers.
newpos += ctrl[1];
oldpos += ctrl[2];
};
// Close input file.
old_file->Close();
// Clean up the bzip2 reads.
BZ2_bzReadClose(&cbz2err, cpfbz2);
BZ2_bzReadClose(&dbz2err, dpfbz2);
BZ2_bzReadClose(&ebz2err, epfbz2);
if (fclose(cpf) || fclose(dpf) || fclose(epf))
err(1, "fclose(%s)", patch_filename);
// Write the new file.
std::unique_ptr<FileInterface> new_file =
File::FOpen(new_filename, O_CREAT | O_WRONLY);
if (!new_file)
err(1, "Error opening the new filename %s", new_filename);
if (using_extents) {
std::vector<ex_t> parsed_new_extents;
if (!ParseExtentStr(new_extents, &parsed_new_extents))
errx(1, "Error parsing the new extents");
new_file.reset(new ExtentsFile(std::move(new_file), parsed_new_extents));
}
u_char* temp_new_buf = new_buf; // new_buf needed for free()
while (newsize > 0) {
size_t bytes_written;
if (!new_file->Write(temp_new_buf, newsize, &bytes_written))
err(1, "Error writing new file %s", new_filename);
newsize -= bytes_written;
temp_new_buf += bytes_written;
}
if (!new_file->Close())
err(1, "Error closing new file %s", new_filename);
free(new_buf);
return 0;
}
} // namespace bsdiff