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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. An archive is a single file holding
26//config: a collection of other files in a structure that makes it possible to
27//config: retrieve the original individual files (called archive members).
28//config: The original files' contents, mode (permissions), timestamp, owner,
29//config: and group are preserved in the archive, and can be restored on
30//config: extraction.
31//config:
32//config: The stored filename is limited to 15 characters. (for more information
33//config: see long filename support).
34//config: ar has 60 bytes of overheads for every stored file.
35//config:
36//config: This implementation of ar can extract archives, it cannot create or
37//config: modify them.
38//config: On an x86 system, the ar applet adds about 1K.
39//config:
40//config: Unless you have a specific application which requires ar, you should
41//config: probably say N here.
42//config:
43//config:config FEATURE_AR_LONG_FILENAMES
44//config: bool "Support for long filenames (not needed for debs)"
45//config: default y
46//config: depends on AR
47//config: help
48//config: By default the ar format can only store the first 15 characters
49//config: of the filename, this option removes that limitation.
50//config: It supports the GNU ar long filename method which moves multiple long
51//config: filenames into a the data section of a new ar entry.
52//config:
53//config:config FEATURE_AR_CREATE
54//config: bool "Support archive creation"
55//config: default y
56//config: depends on AR
57//config: help
58//config: This enables archive creation (-c and -r) with busybox ar.
59
60//applet:IF_AR(APPLET(ar, BB_DIR_USR_BIN, BB_SUID_DROP))
61//kbuild:lib-$(CONFIG_AR) += ar.o
62
63//usage:#define ar_trivial_usage
64//usage: "[-o] [-v] [-p] [-t] [-x] ARCHIVE FILES"
65//usage:#define ar_full_usage "\n\n"
66//usage: "Extract or list FILES from an ar archive\n"
67//usage: "\n -o Preserve original dates"
68//usage: "\n -p Extract to stdout"
69//usage: "\n -t List"
70//usage: "\n -x Extract"
71//usage: "\n -v Verbose"
72
73#include "libbb.h"
74#include "bb_archive.h"
75#include "ar.h"
76
77#if ENABLE_FEATURE_AR_CREATE
78/* filter out entries with same names as specified on the command line */
79static char FAST_FUNC filter_replaceable(archive_handle_t *handle)
80{
81 if (find_list_entry(handle->accept, handle->file_header->name))
82 return EXIT_FAILURE;
83
84 return EXIT_SUCCESS;
85}
86
87static void output_ar_header(archive_handle_t *handle)
88{
89 /* GNU ar 2.19.51.0.14 creates malformed archives
90 * if input files are >10G. It also truncates files >4GB
91 * (uses "size mod 4G"). We abort in this case:
92 * We could add support for up to 10G files, but this is unlikely to be useful.
93 * Note that unpacking side limits all fields to "unsigned int" data type,
94 * and treats "all ones" as an error indicator. Thus max we allow here is UINT_MAX-1.
95 */
96 enum {
97 /* for 2nd field: mtime */
98 MAX11CHARS = UINT_MAX > 0xffffffff ? (unsigned)99999999999 : UINT_MAX-1,
99 /* for last field: filesize */
100 MAX10CHARS = UINT_MAX > 0xffffffff ? (unsigned)9999999999 : UINT_MAX-1,
101 };
102
103 struct file_header_t *fh = handle->file_header;
104
105 if (handle->offset & 1) {
106 xwrite(handle->src_fd, "\n", 1);
107 handle->offset++;
108 }
109
110 /* Careful! The widths should be exact. Fields must be separated */
111 if (sizeof(off_t) > 4 && fh->size > (off_t)MAX10CHARS) {
112 bb_error_msg_and_die("'%s' is bigger than ar can handle", fh->name);
113 }
114 fdprintf(handle->src_fd, "%-16.16s%-12lu%-6u%-6u%-8o%-10"OFF_FMT"u`\n",
115 fh->name,
116 (sizeof(time_t) > 4 && fh->mtime > MAX11CHARS) ? (long)0 : (long)fh->mtime,
117 fh->uid > 99999 ? 0 : (int)fh->uid,
118 fh->gid > 99999 ? 0 : (int)fh->gid,
119 (int)fh->mode & 07777777,
120 fh->size
121 );
122
123 handle->offset += AR_HEADER_LEN;
124}
125
126/*
127 * when replacing files in an existing archive, copy from the
128 * original archive those files that are to be left intact
129 */
130static void FAST_FUNC copy_data(archive_handle_t *handle)
131{
132 archive_handle_t *out_handle = handle->ar__out;
133 struct file_header_t *fh = handle->file_header;
134
135 out_handle->file_header = fh;
136 output_ar_header(out_handle);
137
138 bb_copyfd_exact_size(handle->src_fd, out_handle->src_fd, fh->size);
139 out_handle->offset += fh->size;
140}
141
142static int write_ar_header(archive_handle_t *handle)
143{
144 char *fn;
145 char fn_h[17]; /* 15 + "/" + NUL */
146 struct stat st;
147 int fd;
148
149 fn = llist_pop(&handle->accept);
150 if (!fn)
151 return -1;
152
153 xstat(fn, &st);
154
155 handle->file_header->mtime = st.st_mtime;
156 handle->file_header->uid = st.st_uid;
157 handle->file_header->gid = st.st_gid;
158 handle->file_header->mode = st.st_mode;
159 handle->file_header->size = st.st_size;
160 handle->file_header->name = fn_h;
161//TODO: if ENABLE_FEATURE_AR_LONG_FILENAMES...
162 sprintf(fn_h, "%.15s/", bb_basename(fn));
163
164 output_ar_header(handle);
165
166 fd = xopen(fn, O_RDONLY);
167 bb_copyfd_exact_size(fd, handle->src_fd, st.st_size);
168 close(fd);
169 handle->offset += st.st_size;
170
171 return 0;
172}
173
174static int write_ar_archive(archive_handle_t *handle)
175{
176 struct stat st;
177 archive_handle_t *out_handle;
178
179 xfstat(handle->src_fd, &st, handle->ar__name);
180
181 /* if archive exists, create a new handle for output.
182 * we create it in place of the old one.
183 */
184 if (st.st_size != 0) {
185 out_handle = init_handle();
186 xunlink(handle->ar__name);
187 out_handle->src_fd = xopen(handle->ar__name, O_WRONLY | O_CREAT | O_TRUNC);
188 out_handle->accept = handle->accept;
189 } else {
190 out_handle = handle;
191 }
192
193 handle->ar__out = out_handle;
194
195 xwrite(out_handle->src_fd, AR_MAGIC "\n", AR_MAGIC_LEN + 1);
196 out_handle->offset += AR_MAGIC_LEN + 1;
197
198 /* skip to the end of the archive if we have to append stuff */
199 if (st.st_size != 0) {
200 handle->filter = filter_replaceable;
201 handle->action_data = copy_data;
202 unpack_ar_archive(handle);
203 }
204
205 while (write_ar_header(out_handle) == 0)
206 continue;
207
208 /* optional, since we exit right after we return */
209 if (ENABLE_FEATURE_CLEAN_UP) {
210 close(handle->src_fd);
211 if (out_handle->src_fd != handle->src_fd)
212 close(out_handle->src_fd);
213 }
214
215 return EXIT_SUCCESS;
216}
217#endif /* FEATURE_AR_CREATE */
218
219static void FAST_FUNC header_verbose_list_ar(const file_header_t *file_header)
220{
221 const char *mode = bb_mode_string(file_header->mode);
222 char *mtime;
223
224 mtime = ctime(&file_header->mtime);
225 mtime[16] = ' ';
226 memmove(&mtime[17], &mtime[20], 4);
227 mtime[21] = '\0';
228 printf("%s %u/%u%7"OFF_FMT"u %s %s\n", &mode[1],
229 (int)file_header->uid, (int)file_header->gid,
230 file_header->size,
231 &mtime[4], file_header->name
232 );
233}
234
235#define AR_OPT_VERBOSE (1 << 0)
236#define AR_OPT_PRESERVE_DATE (1 << 1)
237/* "ar r" implies create, but warns about it. c suppresses warning.
238 * bbox accepts but ignores it: */
239#define AR_OPT_CREATE (1 << 2)
240
241#define AR_CMD_PRINT (1 << 3)
242#define FIRST_CMD AR_CMD_PRINT
243#define AR_CMD_LIST (1 << 4)
244#define AR_CMD_EXTRACT (1 << 5)
245#define AR_CMD_INSERT (1 << 6)
246
247int ar_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
248int ar_main(int argc UNUSED_PARAM, char **argv)
249{
250 archive_handle_t *archive_handle;
251 unsigned opt, t;
252
253 archive_handle = init_handle();
254
255 /* --: prepend '-' to the first argument if required */
256 /* -1: at least one param is reqd */
257 /* one of p,t,x[,r] is required */
258 opt_complementary = "--:-1:p:t:x"IF_FEATURE_AR_CREATE(":r");
259 opt = getopt32(argv, "voc""ptx"IF_FEATURE_AR_CREATE("r"));
260 argv += optind;
261
262 t = opt / FIRST_CMD;
263 if (t & (t-1)) /* more than one of p,t,x[,r] are specified */
264 bb_show_usage();
265
266 if (opt & AR_CMD_PRINT) {
267 archive_handle->action_data = data_extract_to_stdout;
268 }
269 if (opt & AR_CMD_LIST) {
270 archive_handle->action_header = header_list;
271 }
272 if (opt & AR_CMD_EXTRACT) {
273 archive_handle->action_data = data_extract_all;
274 }
275 if (opt & AR_OPT_PRESERVE_DATE) {
276 archive_handle->ah_flags |= ARCHIVE_RESTORE_DATE;
277 }
278 if (opt & AR_OPT_VERBOSE) {
279 archive_handle->action_header = header_verbose_list_ar;
280 }
281#if ENABLE_FEATURE_AR_CREATE
282 archive_handle->ar__name = *argv;
283#endif
284 archive_handle->src_fd = xopen(*argv++,
285 (opt & AR_CMD_INSERT)
286 ? O_RDWR | O_CREAT
287 : O_RDONLY
288 );
289
290 if (*argv)
291 archive_handle->filter = filter_accept_list;
292 while (*argv) {
293 llist_add_to_end(&archive_handle->accept, *argv++);
294 }
295
296#if ENABLE_FEATURE_AR_CREATE
297 if (opt & AR_CMD_INSERT)
298 return write_ar_archive(archive_handle);
299#endif
300
301 unpack_ar_archive(archive_handle);
302
303 return EXIT_SUCCESS;
304}
305
generated by cgit at 2024-05-15 12:59:51 (GMT)