xref: /aosp_15_r20/external/sandboxed-api/oss-internship-2020/libarchive/ld_preload_example/minitar.cc (revision ec63e07ab9515d95e79c211197c445ef84cefa6a)
1 // Copyright 2020 Google LLC
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 //     https://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14 
15 // clang-format off
16 #include "minitar.h"  // NOLINT(build/include)
17 
18 /*
19  * NO_CREATE implies NO_BZIP2_CREATE and NO_GZIP_CREATE and NO_COMPRESS_CREATE.
20  */
21 #ifdef NO_CREATE
22 #undef NO_BZIP2_CREATE
23 #define NO_BZIP2_CREATE
24 #undef NO_COMPRESS_CREATE
25 #define NO_COMPRESS_CREATE
26 #undef NO_GZIP_CREATE
27 #define NO_GZIP_CREATE
28 #endif
29 
30 /*
31  * The combination of NO_BZIP2_CREATE and NO_BZIP2_EXTRACT is
32  * equivalent to NO_BZIP2.
33  */
34 #ifdef NO_BZIP2_CREATE
35 #ifdef NO_BZIP2_EXTRACT
36 #undef NO_BZIP2
37 #define NO_BZIP2
38 #endif
39 #endif
40 
41 #ifdef NO_BZIP2
42 #undef NO_BZIP2_EXTRACT
43 #define NO_BZIP2_EXTRACT
44 #undef NO_BZIP2_CREATE
45 #define NO_BZIP2_CREATE
46 #endif
47 
48 /*
49  * The combination of NO_COMPRESS_CREATE and NO_COMPRESS_EXTRACT is
50  * equivalent to NO_COMPRESS.
51  */
52 #ifdef NO_COMPRESS_CREATE
53 #ifdef NO_COMPRESS_EXTRACT
54 #undef NO_COMPRESS
55 #define NO_COMPRESS
56 #endif
57 #endif
58 
59 #ifdef NO_COMPRESS
60 #undef NO_COMPRESS_EXTRACT
61 #define NO_COMPRESS_EXTRACT
62 #undef NO_COMPRESS_CREATE
63 #define NO_COMPRESS_CREATE
64 #endif
65 
66 /*
67  * The combination of NO_GZIP_CREATE and NO_GZIP_EXTRACT is
68  * equivalent to NO_GZIP.
69  */
70 #ifdef NO_GZIP_CREATE
71 #ifdef NO_GZIP_EXTRACT
72 #undef NO_GZIP
73 #define NO_GZIP
74 #endif
75 #endif
76 
77 #ifdef NO_GZIP
78 #undef NO_GZIP_EXTRACT
79 #define NO_GZIP_EXTRACT
80 #undef NO_GZIP_CREATE
81 #define NO_GZIP_CREATE
82 #endif
83 
84 #ifndef NO_CREATE
85 void create(const char* filename, int compress, const char** argv);
86 #endif
87 void errmsg(const char*);
88 void extract(const char* filename, int do_extract, int flags);
89 int copy_data(struct archive*, struct archive*);
90 void msg(const char*);
91 void usage(void);
92 
93 #ifndef NO_CREATE
94 
create(const char * filename,int compress,const char ** argv,int verbose)95 void create(const char* filename, int compress, const char** argv,
96             int verbose) {
97   struct archive* a;
98   struct archive_entry* entry;
99   ssize_t len;
100   int fd;
101 
102   a = archive_write_new();
103   switch (compress) {
104 #ifndef NO_BZIP2_CREATE
105     case 'j':
106     case 'y':
107       archive_write_add_filter_bzip2(a);
108       break;
109 #endif
110 #ifndef NO_COMPRESS_CREATE
111     case 'Z':
112       archive_write_add_filter_compress(a);
113       break;
114 #endif
115 #ifndef NO_GZIP_CREATE
116     case 'z':
117       archive_write_add_filter_gzip(a);
118       break;
119 #endif
120     default:
121       archive_write_add_filter_none(a);
122       break;
123   }
124   archive_write_set_format_ustar(a);
125   if (filename != NULL && strcmp(filename, "-") == 0) filename = NULL;
126   archive_write_open_filename(a, filename);
127 
128   while (*argv != NULL) {
129     struct archive* disk = archive_read_disk_new();
130 #ifndef NO_LOOKUP
131     archive_read_disk_set_standard_lookup(disk);
132 #endif
133     int r;
134 
135     r = archive_read_disk_open(disk, *argv);
136     if (r != ARCHIVE_OK) {
137       errmsg(archive_error_string(disk));
138       errmsg("\n");
139       exit(1);
140     }
141 
142     for (;;) {
143       int needcr = 0;
144 
145       entry = archive_entry_new();
146       r = archive_read_next_header2(disk, entry);
147       if (r == ARCHIVE_EOF) break;
148       if (r != ARCHIVE_OK) {
149         errmsg(archive_error_string(disk));
150         errmsg("\n");
151         exit(1);
152       }
153       archive_read_disk_descend(disk);
154       if (verbose) {
155         msg("a ");
156         msg(archive_entry_pathname(entry));
157         needcr = 1;
158       }
159       r = archive_write_header(a, entry);
160       if (r < ARCHIVE_OK) {
161         errmsg(": ");
162         errmsg(archive_error_string(a));
163         needcr = 1;
164       }
165       if (r == ARCHIVE_FATAL) exit(1);
166       if (r > ARCHIVE_FAILED) {
167         static char buff[16384];
168         fd = open(archive_entry_sourcepath(entry), O_RDONLY);
169         len = read(fd, buff, sizeof(buff));
170         while (len > 0) {
171           archive_write_data(a, buff, len);
172           len = read(fd, buff, sizeof(buff));
173         }
174         close(fd);
175       }
176       archive_entry_free(entry);
177       if (needcr) msg("\n");
178     }
179     archive_read_close(disk);
180     archive_read_free(disk);
181     argv++;
182   }
183   archive_write_close(a);
184   archive_write_free(a);
185 }
186 #endif
187 
extract(const char * filename,int do_extract,int flags,int verbose)188 void extract(const char* filename, int do_extract, int flags, int verbose) {
189   struct archive* a;
190   struct archive* ext;
191   struct archive_entry* entry;
192   int r;
193 
194   a = archive_read_new();
195   ext = archive_write_disk_new();
196   archive_write_disk_set_options(ext, flags);
197 #ifndef NO_BZIP2_EXTRACT
198   archive_read_support_filter_bzip2(a);
199 #endif
200 #ifndef NO_GZIP_EXTRACT
201   archive_read_support_filter_gzip(a);
202 #endif
203 #ifndef NO_COMPRESS_EXTRACT
204   archive_read_support_filter_compress(a);
205 #endif
206 #ifndef NO_TAR_EXTRACT
207   archive_read_support_format_tar(a);
208 #endif
209 #ifndef NO_CPIO_EXTRACT
210   archive_read_support_format_cpio(a);
211 #endif
212 #ifndef NO_LOOKUP
213   archive_write_disk_set_standard_lookup(ext);
214 #endif
215   if (filename != NULL && strcmp(filename, "-") == 0) filename = NULL;
216   if ((r = archive_read_open_filename(a, filename, 10240))) {
217     errmsg(archive_error_string(a));
218     errmsg("\n");
219     exit(r);
220   }
221   for (;;) {
222     int needcr = 0;
223     r = archive_read_next_header(a, &entry);
224     if (r == ARCHIVE_EOF) break;
225     if (r != ARCHIVE_OK) {
226       errmsg(archive_error_string(a));
227       errmsg("\n");
228       exit(1);
229     }
230     if (verbose && do_extract) msg("x ");
231 
232     if (verbose || !do_extract) {
233       std::cout << archive_entry_pathname(entry) << std::endl;
234       msg(" ");
235       needcr = 1;
236     }
237     if (do_extract) {
238       r = archive_write_header(ext, entry);
239       if (r != ARCHIVE_OK) {
240         errmsg(archive_error_string(a));
241         needcr = 1;
242       } else {
243         r = copy_data(a, ext);
244         if (r != ARCHIVE_OK) needcr = 1;
245       }
246     }
247     if (needcr) msg("\n");
248   }
249   archive_read_close(a);
250   archive_read_free(a);
251 
252   archive_write_close(ext);
253   archive_write_free(ext);
254 }
255 
copy_data(struct archive * ar,struct archive * aw)256 int copy_data(struct archive* ar, struct archive* aw) {
257   int r;
258   const void* buff;
259   size_t size;
260   int64_t offset;
261 
262   for (;;) {
263     r = archive_read_data_block(ar, &buff, &size, &offset);
264     if (r == ARCHIVE_EOF) return (ARCHIVE_OK);
265     if (r != ARCHIVE_OK) {
266       errmsg(archive_error_string(ar));
267       return (r);
268     }
269     r = archive_write_data_block(aw, buff, size, offset);
270     if (r != ARCHIVE_OK) {
271       errmsg(archive_error_string(ar));
272       return (r);
273     }
274   }
275 }
276 
msg(const char * m)277 void msg(const char* m) { write(1, m, strlen(m)); }
278 
errmsg(const char * m)279 void errmsg(const char* m) {
280   if (m == NULL) {
281     m = "Error: No error description provided.\n";
282   }
283   write(2, m, strlen(m));
284 }
285 
usage(void)286 void usage(void) {
287   /* Many program options depend on compile options. */
288   const char* m =
289       "Usage: minitar [-"
290 #ifndef NO_CREATE
291       "c"
292 #endif
293 #ifndef NO_BZIP2
294       "j"
295 #endif
296       "tvx"
297 #ifndef NO_BZIP2
298       "y"
299 #endif
300 #ifndef NO_COMPRESS
301       "Z"
302 #endif
303 #ifndef NO_GZIP
304       "z"
305 #endif
306       "] [-f file] [file]\n";
307 
308   errmsg(m);
309   exit(1);
310 }
311 
312 // clang-format on
313