1 /* vi: set sw=4 ts=4: */
2 /*
3 * Mini ar implementation for busybox
4 *
5 * Copyright (C) 2000 by Glenn McGrath
6 *
7 * Based in part on BusyBox tar, Debian dpkg-deb and GNU ar.
8 *
9 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
10 *
11 * Archive creation support:
12 * Copyright (C) 2010 Nokia Corporation. All rights reserved.
13 * Written by Alexander Shishkin.
14 *
15 * There is no single standard to adhere to so ar may not portable
16 * between different systems
17 * http://www.unix-systems.org/single_unix_specification_v2/xcu/ar.html
18 */
19
20 //config:config AR
21 //config: bool "ar"
22 //config: default n # needs to be improved to be able to replace binutils ar
23 //config: help
24 //config: ar is an archival utility program used to create, modify, and
25 //config: extract contents from archives. In practice, it is used exclusively
26 //config: for object module archives used by compilers.
27 //config:
28 //config: On an x86 system, the ar applet adds about 1K.
29 //config:
30 //config: Unless you have a specific application which requires ar, you should
31 //config: probably say N here: most compilers come with their own ar utility.
32 //config:
33 //config:config FEATURE_AR_LONG_FILENAMES
34 //config: bool "Support for long filenames (not needed for debs)"
35 //config: default y
36 //config: depends on AR
37 //config: help
38 //config: By default the ar format can only store the first 15 characters
39 //config: of the filename, this option removes that limitation.
40 //config: It supports the GNU ar long filename method which moves multiple long
41 //config: filenames into a the data section of a new ar entry.
42 //config:
43 //config:config FEATURE_AR_CREATE
44 //config: bool "Support archive creation"
45 //config: default y
46 //config: depends on AR
47 //config: help
48 //config: This enables archive creation (-c and -r) with busybox ar.
49
50 //applet:IF_AR(APPLET(ar, BB_DIR_USR_BIN, BB_SUID_DROP))
51 //kbuild:lib-$(CONFIG_AR) += ar.o
52
53 //usage:#define ar_trivial_usage
54 //usage: "[-o] [-v] [-p] [-t] [-x] ARCHIVE FILES"
55 //usage:#define ar_full_usage "\n\n"
56 //usage: "Extract or list FILES from an ar archive\n"
57 //usage: "\n -o Preserve original dates"
58 //usage: "\n -p Extract to stdout"
59 //usage: "\n -t List"
60 //usage: "\n -x Extract"
61 //usage: "\n -v Verbose"
62
63 #include "libbb.h"
64 #include "bb_archive.h"
65 #include "ar.h"
66
67 #if ENABLE_FEATURE_AR_CREATE
68 /* filter out entries with same names as specified on the command line */
filter_replaceable(archive_handle_t * handle)69 static char FAST_FUNC filter_replaceable(archive_handle_t *handle)
70 {
71 if (find_list_entry(handle->accept, handle->file_header->name))
72 return EXIT_FAILURE;
73
74 return EXIT_SUCCESS;
75 }
76
output_ar_header(archive_handle_t * handle)77 static void output_ar_header(archive_handle_t *handle)
78 {
79 /* GNU ar 2.19.51.0.14 creates malformed archives
80 * if input files are >10G. It also truncates files >4GB
81 * (uses "size mod 4G"). We abort in this case:
82 * We could add support for up to 10G files, but this is unlikely to be useful.
83 * Note that unpacking side limits all fields to "unsigned int" data type,
84 * and treats "all ones" as an error indicator. Thus max we allow here is UINT_MAX-1.
85 */
86 enum {
87 /* for 2nd field: mtime */
88 MAX11CHARS = UINT_MAX > 0xffffffff ? (unsigned)99999999999 : UINT_MAX-1,
89 /* for last field: filesize */
90 MAX10CHARS = UINT_MAX > 0xffffffff ? (unsigned)9999999999 : UINT_MAX-1,
91 };
92
93 struct file_header_t *fh = handle->file_header;
94
95 if (handle->offset & 1) {
96 xwrite(handle->src_fd, "\n", 1);
97 handle->offset++;
98 }
99
100 /* Careful! The widths should be exact. Fields must be separated */
101 if (sizeof(off_t) > 4 && fh->size > (off_t)MAX10CHARS) {
102 bb_error_msg_and_die("'%s' is bigger than ar can handle", fh->name);
103 }
104 fdprintf(handle->src_fd, "%-16.16s%-12lu%-6u%-6u%-8o%-10"OFF_FMT"u`\n",
105 fh->name,
106 (sizeof(time_t) > 4 && fh->mtime > MAX11CHARS) ? (long)0 : (long)fh->mtime,
107 fh->uid > 99999 ? 0 : (int)fh->uid,
108 fh->gid > 99999 ? 0 : (int)fh->gid,
109 (int)fh->mode & 07777777,
110 fh->size
111 );
112
113 handle->offset += AR_HEADER_LEN;
114 }
115
116 /*
117 * when replacing files in an existing archive, copy from the
118 * original archive those files that are to be left intact
119 */
copy_data(archive_handle_t * handle)120 static void FAST_FUNC copy_data(archive_handle_t *handle)
121 {
122 archive_handle_t *out_handle = handle->ar__out;
123 struct file_header_t *fh = handle->file_header;
124
125 out_handle->file_header = fh;
126 output_ar_header(out_handle);
127
128 bb_copyfd_exact_size(handle->src_fd, out_handle->src_fd, fh->size);
129 out_handle->offset += fh->size;
130 }
131
write_ar_header(archive_handle_t * handle)132 static int write_ar_header(archive_handle_t *handle)
133 {
134 char *fn;
135 char fn_h[17]; /* 15 + "/" + NUL */
136 struct stat st;
137 int fd;
138
139 fn = llist_pop(&handle->accept);
140 if (!fn)
141 return -1;
142
143 xstat(fn, &st);
144
145 handle->file_header->mtime = st.st_mtime;
146 handle->file_header->uid = st.st_uid;
147 handle->file_header->gid = st.st_gid;
148 handle->file_header->mode = st.st_mode;
149 handle->file_header->size = st.st_size;
150 handle->file_header->name = fn_h;
151 //TODO: if ENABLE_FEATURE_AR_LONG_FILENAMES...
152 sprintf(fn_h, "%.15s/", bb_basename(fn));
153
154 output_ar_header(handle);
155
156 fd = xopen(fn, O_RDONLY);
157 bb_copyfd_exact_size(fd, handle->src_fd, st.st_size);
158 close(fd);
159 handle->offset += st.st_size;
160
161 return 0;
162 }
163
write_ar_archive(archive_handle_t * handle)164 static int write_ar_archive(archive_handle_t *handle)
165 {
166 struct stat st;
167 archive_handle_t *out_handle;
168
169 xfstat(handle->src_fd, &st, handle->ar__name);
170
171 /* if archive exists, create a new handle for output.
172 * we create it in place of the old one.
173 */
174 if (st.st_size != 0) {
175 out_handle = init_handle();
176 xunlink(handle->ar__name);
177 out_handle->src_fd = xopen(handle->ar__name, O_WRONLY | O_CREAT | O_TRUNC);
178 out_handle->accept = handle->accept;
179 } else {
180 out_handle = handle;
181 }
182
183 handle->ar__out = out_handle;
184
185 xwrite(out_handle->src_fd, AR_MAGIC "\n", AR_MAGIC_LEN + 1);
186 out_handle->offset += AR_MAGIC_LEN + 1;
187
188 /* skip to the end of the archive if we have to append stuff */
189 if (st.st_size != 0) {
190 handle->filter = filter_replaceable;
191 handle->action_data = copy_data;
192 unpack_ar_archive(handle);
193 }
194
195 while (write_ar_header(out_handle) == 0)
196 continue;
197
198 /* optional, since we exit right after we return */
199 if (ENABLE_FEATURE_CLEAN_UP) {
200 close(handle->src_fd);
201 if (out_handle->src_fd != handle->src_fd)
202 close(out_handle->src_fd);
203 }
204
205 return EXIT_SUCCESS;
206 }
207 #endif /* FEATURE_AR_CREATE */
208
header_verbose_list_ar(const file_header_t * file_header)209 static void FAST_FUNC header_verbose_list_ar(const file_header_t *file_header)
210 {
211 const char *mode = bb_mode_string(file_header->mode);
212 char *mtime;
213
214 mtime = ctime(&file_header->mtime);
215 mtime[16] = ' ';
216 memmove(&mtime[17], &mtime[20], 4);
217 mtime[21] = '\0';
218 printf("%s %u/%u%7"OFF_FMT"u %s %s\n", &mode[1],
219 (int)file_header->uid, (int)file_header->gid,
220 file_header->size,
221 &mtime[4], file_header->name
222 );
223 }
224
225 #define AR_OPT_VERBOSE (1 << 0)
226 #define AR_OPT_PRESERVE_DATE (1 << 1)
227 /* "ar r" implies create, but warns about it. c suppresses warning.
228 * bbox accepts but ignores it: */
229 #define AR_OPT_CREATE (1 << 2)
230
231 #define AR_CMD_PRINT (1 << 3)
232 #define FIRST_CMD AR_CMD_PRINT
233 #define AR_CMD_LIST (1 << 4)
234 #define AR_CMD_EXTRACT (1 << 5)
235 #define AR_CMD_INSERT (1 << 6)
236
237 int ar_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
ar_main(int argc UNUSED_PARAM,char ** argv)238 int ar_main(int argc UNUSED_PARAM, char **argv)
239 {
240 archive_handle_t *archive_handle;
241 unsigned opt, t;
242
243 archive_handle = init_handle();
244
245 /* --: prepend '-' to the first argument if required */
246 /* -1: at least one param is reqd */
247 /* one of p,t,x[,r] is required */
248 opt_complementary = "--:-1:p:t:x"IF_FEATURE_AR_CREATE(":r");
249 opt = getopt32(argv, "voc""ptx"IF_FEATURE_AR_CREATE("r"));
250 argv += optind;
251
252 t = opt / FIRST_CMD;
253 if (t & (t-1)) /* more than one of p,t,x[,r] are specified */
254 bb_show_usage();
255
256 if (opt & AR_CMD_PRINT) {
257 archive_handle->action_data = data_extract_to_stdout;
258 }
259 if (opt & AR_CMD_LIST) {
260 archive_handle->action_header = header_list;
261 }
262 if (opt & AR_CMD_EXTRACT) {
263 archive_handle->action_data = data_extract_all;
264 }
265 if (opt & AR_OPT_PRESERVE_DATE) {
266 archive_handle->ah_flags |= ARCHIVE_RESTORE_DATE;
267 }
268 if (opt & AR_OPT_VERBOSE) {
269 archive_handle->action_header = header_verbose_list_ar;
270 }
271 #if ENABLE_FEATURE_AR_CREATE
272 archive_handle->ar__name = *argv;
273 #endif
274 archive_handle->src_fd = xopen(*argv++,
275 (opt & AR_CMD_INSERT)
276 ? O_RDWR | O_CREAT
277 : O_RDONLY
278 );
279
280 if (*argv)
281 archive_handle->filter = filter_accept_list;
282 while (*argv) {
283 llist_add_to_end(&archive_handle->accept, *argv++);
284 }
285
286 #if ENABLE_FEATURE_AR_CREATE
287 if (opt & AR_CMD_INSERT)
288 return write_ar_archive(archive_handle);
289 #endif
290
291 unpack_ar_archive(archive_handle);
292
293 return EXIT_SUCCESS;
294 }
295