1 // Copyright 2015 The Chromium OS Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include <err.h>
6 #include <fcntl.h>
7 #include <getopt.h>
8 #include <sys/mman.h>
9 #include <sys/stat.h>
10 #include <sys/types.h>
11 #include <unistd.h>
12
13 #include <stddef.h>
14 #include <stdio.h>
15 #include <stdlib.h>
16
17 #include <iostream>
18 #include <limits>
19
20 #include "bsdiff/bsdiff.h"
21 #include "bsdiff/bsdiff_arguments.h"
22 #include "bsdiff/constants.h"
23 #include "bsdiff/patch_writer_factory.h"
24
25 namespace {
26
27 // mmap() the passed |filename| to read-only memory and store in |filesize| the
28 // size of the file. To release the memory, call munmap with the returned
29 // pointer and filesize. In case of error returns nullptr.
MapFile(const char * filename,size_t * filesize)30 void* MapFile(const char* filename, size_t* filesize) {
31 int fd = open(filename, O_RDONLY);
32 if (fd < 0) {
33 perror("open()");
34 return nullptr;
35 }
36
37 struct stat st;
38 fstat(fd, &st);
39 if (static_cast<uint64_t>(st.st_size) > std::numeric_limits<size_t>::max()) {
40 fprintf(stderr, "File too big\n");
41 close(fd);
42 return nullptr;
43 }
44 *filesize = st.st_size;
45
46 void* ret = mmap(nullptr, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
47 if (ret == MAP_FAILED) {
48 perror("mmap()");
49 close(fd);
50 return nullptr;
51 }
52 close(fd);
53 return ret;
54 }
55
56 // Generate bsdiff patch from the |old_filename| file to the |new_filename|
57 // file with options in |arguments|. Store the resulting patch in a new
58 // |patch_filename| file. Returns 0 on success.
GenerateBsdiffFromFiles(const char * old_filename,const char * new_filename,const char * patch_filename,const bsdiff::BsdiffArguments & arguments)59 int GenerateBsdiffFromFiles(const char* old_filename,
60 const char* new_filename,
61 const char* patch_filename,
62 const bsdiff::BsdiffArguments& arguments) {
63 size_t oldsize;
64 uint8_t* old_buf = static_cast<uint8_t*>(MapFile(old_filename, &oldsize));
65 if (!old_buf) {
66 return 1;
67 }
68
69 size_t newsize;
70 uint8_t* new_buf = static_cast<uint8_t*>(MapFile(new_filename, &newsize));
71 if (!new_buf) {
72 munmap(old_buf, oldsize);
73 return 1;
74 }
75
76 std::unique_ptr<bsdiff::PatchWriterInterface> patch_writer;
77 std::vector<uint8_t> raw_data;
78
79 if (arguments.format() == bsdiff::BsdiffFormat::kLegacy) {
80 patch_writer = bsdiff::CreateBsdiffPatchWriter(patch_filename);
81 } else if (arguments.format() == bsdiff::BsdiffFormat::kBsdf2) {
82 patch_writer = bsdiff::CreateBSDF2PatchWriter(
83 patch_filename, arguments.compressor_type(),
84 arguments.compression_quality());
85 } else if (arguments.format() == bsdiff::BsdiffFormat::kEndsley) {
86 patch_writer =
87 bsdiff::CreateEndsleyPatchWriter(&raw_data, arguments.compressor_type(),
88 arguments.compression_quality());
89 } else {
90 std::cerr << "unexpected bsdiff format." << std::endl;
91 return 1;
92 }
93
94 int ret = bsdiff::bsdiff(old_buf, oldsize, new_buf, newsize,
95 arguments.min_length(), patch_writer.get(), nullptr);
96
97 munmap(old_buf, oldsize);
98 munmap(new_buf, newsize);
99
100 if (!ret && arguments.format() == bsdiff::BsdiffFormat::kEndsley) {
101 // Store the raw_data on disk.
102 FILE* fp = fopen(patch_filename, "wb");
103 if (!fp) {
104 perror("Opening the patch file");
105 return 1;
106 }
107 if (raw_data.size() != fwrite(raw_data.data(), 1, raw_data.size(), fp)) {
108 perror("Writing to the patch file");
109 ret = 1;
110 }
111 fclose(fp);
112 }
113 return ret;
114 }
115
PrintUsage(const std::string & proc_name)116 void PrintUsage(const std::string& proc_name) {
117 std::cerr << "usage: " << proc_name
118 << " [options] oldfile newfile patchfile\n";
119 std::cerr << " --format <legacy|bsdiff40|bsdf2|endsley> The format of the"
120 " bsdiff patch.\n"
121 << " --minlen LEN The minimum match length "
122 "required to consider a match in the algorithm.\n"
123 << " --type <bz2|brotli|nocompression> The algorithm to compress "
124 "the patch, bsdf2 format only.\n"
125 << " --quality Quality of the patch "
126 "compression, brotli only.\n";
127 }
128
129 } // namespace
130
main(int argc,char * argv[])131 int main(int argc, char* argv[]) {
132 bsdiff::BsdiffArguments arguments;
133
134 if (!arguments.ParseCommandLine(argc, argv)) {
135 PrintUsage(argv[0]);
136 return 1;
137 }
138
139 // The optind will be updated in ParseCommandLine to parse the options; and
140 // we expect the rest of the arguments to be oldfile, newfile, patchfile.
141 if (!arguments.IsValid() || argc - optind != 3) {
142 PrintUsage(argv[0]);
143 return 1;
144 }
145
146 return GenerateBsdiffFromFiles(argv[optind], argv[optind + 1],
147 argv[optind + 2], arguments);
148 }
149