diff options
Diffstat (limited to 'applypatch/bspatch.c')
| -rw-r--r-- | applypatch/bspatch.c | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/applypatch/bspatch.c b/applypatch/bspatch.c new file mode 100644 index 000000000..d5cd6174d --- /dev/null +++ b/applypatch/bspatch.c @@ -0,0 +1,252 @@ +/* + * 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 <errno.h> +#include <unistd.h> +#include <string.h> + +#include <bzlib.h> + +#include "mincrypt/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 ApplyBSDiffPatch(const unsigned char* old_data, ssize_t old_size, + const char* patch_filename, ssize_t patch_offset, + SinkFn sink, void* token, SHA_CTX* ctx) { + + unsigned char* new_data; + ssize_t new_size; + if (ApplyBSDiffPatchMem(old_data, old_size, patch_filename, patch_offset, + &new_data, &new_size) != 0) { + return -1; + } + + if (sink(new_data, new_size, token) < new_size) { + fprintf(stderr, "short write of output: %d (%s)\n", errno, strerror(errno)); + return 1; + } + if (ctx) { + SHA_update(ctx, new_data, new_size); + } + free(new_data); + + return 0; +} + +int ApplyBSDiffPatchMem(const unsigned char* old_data, ssize_t old_size, + const char* patch_filename, ssize_t patch_offset, + unsigned char** new_data, ssize_t* new_size) { + + FILE* f; + if ((f = fopen(patch_filename, "rb")) == NULL) { + fprintf(stderr, "failed to open patch file\n"); + return 1; + } + + // File 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". + + fseek(f, patch_offset, SEEK_SET); + + unsigned char header[32]; + if (fread(header, 1, 32, f) < 32) { + fprintf(stderr, "failed to read patch file header\n"); + return 1; + } + + if (memcmp(header, "BSDIFF40", 8) != 0) { + fprintf(stderr, "corrupt bsdiff patch file header (magic number)\n"); + return 1; + } + + ssize_t ctrl_len, data_len; + 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) { + fprintf(stderr, "corrupt patch file header (data lengths)\n"); + return 1; + } + + fclose(f); + + int bzerr; + +#define OPEN_AT(f, bzf, offset) \ + FILE* f; \ + BZFILE* bzf; \ + if ((f = fopen(patch_filename, "rb")) == NULL) { \ + fprintf(stderr, "failed to open patch file\n"); \ + return 1; \ + } \ + if (fseeko(f, offset+patch_offset, SEEK_SET)) { \ + fprintf(stderr, "failed to seek in patch file\n"); \ + return 1; \ + } \ + if ((bzf = BZ2_bzReadOpen(&bzerr, f, 0, 0, NULL, 0)) == NULL) { \ + fprintf(stderr, "failed to bzReadOpen in patch file (%d)\n", bzerr); \ + return 1; \ + } + + OPEN_AT(cpf, cpfbz2, 32); + OPEN_AT(dpf, dpfbz2, 32+ctrl_len); + OPEN_AT(epf, epfbz2, 32+ctrl_len+data_len); + +#undef OPEN_AT + + *new_data = malloc(*new_size); + if (*new_data == NULL) { + fprintf(stderr, "failed to allocate %d bytes of memory for output file\n", + (int)*new_size); + return 1; + } + + off_t oldpos = 0, newpos = 0; + off_t ctrl[3]; + off_t len_read; + int i; + unsigned char buf[8]; + while (newpos < *new_size) { + // Read control data + for (i = 0; i < 3; ++i) { + len_read = BZ2_bzRead(&bzerr, cpfbz2, buf, 8); + if (len_read < 8 || !(bzerr == BZ_OK || bzerr == BZ_STREAM_END)) { + fprintf(stderr, "corrupt patch (read control)\n"); + return 1; + } + ctrl[i] = offtin(buf); + } + + // Sanity check + if (newpos + ctrl[0] > *new_size) { + fprintf(stderr, "corrupt patch (new file overrun)\n"); + return 1; + } + + // Read diff string + len_read = BZ2_bzRead(&bzerr, dpfbz2, *new_data + newpos, ctrl[0]); + if (len_read < ctrl[0] || !(bzerr == BZ_OK || bzerr == BZ_STREAM_END)) { + fprintf(stderr, "corrupt patch (read diff)\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) { + fprintf(stderr, "corrupt patch (new file overrun)\n"); + return 1; + } + + // Read extra string + len_read = BZ2_bzRead(&bzerr, epfbz2, *new_data + newpos, ctrl[1]); + if (len_read < ctrl[1] || !(bzerr == BZ_OK || bzerr == BZ_STREAM_END)) { + fprintf(stderr, "corrupt patch (read extra)\n"); + return 1; + } + + // Adjust pointers + newpos += ctrl[1]; + oldpos += ctrl[2]; + } + + BZ2_bzReadClose(&bzerr, cpfbz2); + BZ2_bzReadClose(&bzerr, dpfbz2); + BZ2_bzReadClose(&bzerr, epfbz2); + fclose(cpf); + fclose(dpf); + fclose(epf); + + return 0; +} |