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Diffstat (limited to '')
| -rw-r--r-- | applypatch/bspatch.cpp | 247 |
1 files changed, 247 insertions, 0 deletions
diff --git a/applypatch/bspatch.cpp b/applypatch/bspatch.cpp new file mode 100644 index 000000000..ebb55f1d1 --- /dev/null +++ b/applypatch/bspatch.cpp @@ -0,0 +1,247 @@ +/* + * Copyright (C) 2008 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. + */ + +// This file is a nearly line-for-line copy of bspatch.c from the +// bsdiff-4.3 distribution; the primary differences being how the +// input and output data are read and the error handling. Running +// applypatch with the -l option will display the bsdiff license +// notice. + +#include <stdio.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <errno.h> +#include <unistd.h> +#include <string.h> + +#include <bzlib.h> + +#include "openssl/sha.h" +#include "applypatch.h" + +void ShowBSDiffLicense() { + puts("The bsdiff library used herein is:\n" + "\n" + "Copyright 2003-2005 Colin Percival\n" + "All rights reserved\n" + "\n" + "Redistribution and use in source and binary forms, with or without\n" + "modification, are permitted providing that the following conditions\n" + "are met:\n" + "1. Redistributions of source code must retain the above copyright\n" + " notice, this list of conditions and the following disclaimer.\n" + "2. Redistributions in binary form must reproduce the above copyright\n" + " notice, this list of conditions and the following disclaimer in the\n" + " documentation and/or other materials provided with the distribution.\n" + "\n" + "THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR\n" + "IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED\n" + "WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE\n" + "ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY\n" + "DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL\n" + "DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS\n" + "OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)\n" + "HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,\n" + "STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING\n" + "IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE\n" + "POSSIBILITY OF SUCH DAMAGE.\n" + "\n------------------\n\n" + "This program uses Julian R Seward's \"libbzip2\" library, available\n" + "from http://www.bzip.org/.\n" + ); +} + +static off_t offtin(u_char *buf) +{ + off_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; +} + +int FillBuffer(unsigned char* buffer, int size, bz_stream* stream) { + stream->next_out = (char*)buffer; + stream->avail_out = size; + while (stream->avail_out > 0) { + int bzerr = BZ2_bzDecompress(stream); + if (bzerr != BZ_OK && bzerr != BZ_STREAM_END) { + printf("bz error %d decompressing\n", bzerr); + return -1; + } + if (stream->avail_out > 0) { + printf("need %d more bytes\n", stream->avail_out); + } + } + return 0; +} + +int ApplyBSDiffPatch(const unsigned char* old_data, ssize_t old_size, + const Value* patch, ssize_t patch_offset, + SinkFn sink, void* token, SHA_CTX* ctx) { + + std::vector<unsigned char> new_data; + if (ApplyBSDiffPatchMem(old_data, old_size, patch, patch_offset, &new_data) != 0) { + return -1; + } + + if (sink(new_data.data(), new_data.size(), token) < static_cast<ssize_t>(new_data.size())) { + printf("short write of output: %d (%s)\n", errno, strerror(errno)); + return 1; + } + if (ctx) SHA1_Update(ctx, new_data.data(), new_data.size()); + return 0; +} + +int ApplyBSDiffPatchMem(const unsigned char* old_data, ssize_t old_size, + const Value* patch, ssize_t patch_offset, + std::vector<unsigned char>* new_data) { + // Patch data format: + // 0 8 "BSDIFF40" + // 8 8 X + // 16 8 Y + // 24 8 sizeof(newfile) + // 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". + + unsigned char* header = (unsigned char*) patch->data + patch_offset; + if (memcmp(header, "BSDIFF40", 8) != 0) { + printf("corrupt bsdiff patch file header (magic number)\n"); + return 1; + } + + ssize_t ctrl_len, data_len, new_size; + ctrl_len = offtin(header+8); + data_len = offtin(header+16); + new_size = offtin(header+24); + + if (ctrl_len < 0 || data_len < 0 || new_size < 0) { + printf("corrupt patch file header (data lengths)\n"); + return 1; + } + + int bzerr; + + bz_stream cstream; + cstream.next_in = patch->data + patch_offset + 32; + cstream.avail_in = ctrl_len; + cstream.bzalloc = NULL; + cstream.bzfree = NULL; + cstream.opaque = NULL; + if ((bzerr = BZ2_bzDecompressInit(&cstream, 0, 0)) != BZ_OK) { + printf("failed to bzinit control stream (%d)\n", bzerr); + } + + bz_stream dstream; + dstream.next_in = patch->data + patch_offset + 32 + ctrl_len; + dstream.avail_in = data_len; + dstream.bzalloc = NULL; + dstream.bzfree = NULL; + dstream.opaque = NULL; + if ((bzerr = BZ2_bzDecompressInit(&dstream, 0, 0)) != BZ_OK) { + printf("failed to bzinit diff stream (%d)\n", bzerr); + } + + bz_stream estream; + estream.next_in = patch->data + patch_offset + 32 + ctrl_len + data_len; + estream.avail_in = patch->size - (patch_offset + 32 + ctrl_len + data_len); + estream.bzalloc = NULL; + estream.bzfree = NULL; + estream.opaque = NULL; + if ((bzerr = BZ2_bzDecompressInit(&estream, 0, 0)) != BZ_OK) { + printf("failed to bzinit extra stream (%d)\n", bzerr); + } + + new_data->resize(new_size); + + off_t oldpos = 0, newpos = 0; + off_t ctrl[3]; + off_t len_read; + int i; + unsigned char buf[24]; + while (newpos < new_size) { + // Read control data + if (FillBuffer(buf, 24, &cstream) != 0) { + printf("error while reading control stream\n"); + return 1; + } + ctrl[0] = offtin(buf); + ctrl[1] = offtin(buf+8); + ctrl[2] = offtin(buf+16); + + if (ctrl[0] < 0 || ctrl[1] < 0) { + printf("corrupt patch (negative byte counts)\n"); + return 1; + } + + // Sanity check + if (newpos + ctrl[0] > new_size) { + printf("corrupt patch (new file overrun)\n"); + return 1; + } + + // Read diff string + if (FillBuffer(new_data->data() + newpos, ctrl[0], &dstream) != 0) { + printf("error while reading diff stream\n"); + return 1; + } + + // Add old data to diff string + for (i = 0; i < ctrl[0]; ++i) { + if ((oldpos+i >= 0) && (oldpos+i < old_size)) { + (*new_data)[newpos+i] += old_data[oldpos+i]; + } + } + + // Adjust pointers + newpos += ctrl[0]; + oldpos += ctrl[0]; + + // Sanity check + if (newpos + ctrl[1] > new_size) { + printf("corrupt patch (new file overrun)\n"); + return 1; + } + + // Read extra string + if (FillBuffer(new_data->data() + newpos, ctrl[1], &estream) != 0) { + printf("error while reading extra stream\n"); + return 1; + } + + // Adjust pointers + newpos += ctrl[1]; + oldpos += ctrl[2]; + } + + BZ2_bzDecompressEnd(&cstream); + BZ2_bzDecompressEnd(&dstream); + BZ2_bzDecompressEnd(&estream); + return 0; +} |