xref: /freebsd/usr.bin/ar/write.c (revision 2f02600abfddfc4e9f20dd384a2e729b451e16bd)
1 /*-
2  * Copyright (c) 2007 Kai Wang
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer
10  *    in this position and unchanged.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/endian.h>
31 #include <sys/mman.h>
32 #include <sys/queue.h>
33 #include <sys/stat.h>
34 #include <archive.h>
35 #include <archive_entry.h>
36 #include <errno.h>
37 #include <fcntl.h>
38 #include <gelf.h>
39 #include <libgen.h>
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43 #include <sysexits.h>
44 
45 #include "ar.h"
46 
47 #define _ARMAG_LEN 8		/* length of ar magic string */
48 #define _ARHDR_LEN 60		/* length of ar header */
49 #define _INIT_AS_CAP 128	/* initial archive string table size */
50 #define _INIT_SYMOFF_CAP (256*(sizeof(uint32_t))) /* initial so table size */
51 #define _INIT_SYMNAME_CAP 1024			  /* initial sn table size */
52 #define _MAXNAMELEN_SVR4 15	/* max member name length in svr4 variant */
53 #define _TRUNCATE_LEN 15	/* number of bytes to keep for member name */
54 
55 static void	add_to_ar_str_table(struct bsdar *bsdar, const char *name);
56 static void	add_to_ar_sym_table(struct bsdar *bsdar, const char *name);
57 static struct ar_obj	*create_obj_from_file(struct bsdar *bsdar,
58 		    const char *name, time_t mtime);
59 static void	create_symtab_entry(struct bsdar *bsdar, void *maddr,
60 		    size_t size);
61 static void	free_obj(struct bsdar *bsdar, struct ar_obj *obj);
62 static void	insert_obj(struct bsdar *bsdar, struct ar_obj *obj,
63 		    struct ar_obj *pos);
64 static void	read_objs(struct bsdar *bsdar, const char *archive,
65 		    int checkargv);
66 static void	write_archive(struct bsdar *bsdar, char mode);
67 static void	write_cleanup(struct bsdar *bsdar);
68 static void	write_data(struct bsdar *bsdar, struct archive *a,
69 		    const void *buf, size_t s);
70 static void	write_objs(struct bsdar *bsdar);
71 
72 void
73 ar_mode_d(struct bsdar *bsdar)
74 {
75 
76 	write_archive(bsdar, 'd');
77 }
78 
79 void
80 ar_mode_m(struct bsdar *bsdar)
81 {
82 
83 	write_archive(bsdar, 'm');
84 }
85 
86 void
87 ar_mode_q(struct bsdar *bsdar)
88 {
89 
90 	write_archive(bsdar, 'q');
91 }
92 
93 void
94 ar_mode_r(struct bsdar *bsdar)
95 {
96 
97 	write_archive(bsdar, 'r');
98 }
99 
100 void
101 ar_mode_s(struct bsdar *bsdar)
102 {
103 
104 	write_archive(bsdar, 's');
105 }
106 
107 void
108 ar_mode_A(struct bsdar *bsdar)
109 {
110 
111 	write_archive(bsdar, 'A');
112 }
113 
114 /*
115  * Create object from file, return created obj upon success, or NULL
116  * when an error occurs or the member is not newer than existing
117  * one while -u is specified.
118  */
119 static struct ar_obj *
120 create_obj_from_file(struct bsdar *bsdar, const char *name, time_t mtime)
121 {
122 	struct ar_obj		*obj;
123 	struct stat		 sb;
124 	const char		*bname;
125 
126 	if (name == NULL)
127 		return (NULL);
128 
129 	obj = malloc(sizeof(struct ar_obj));
130 	if (obj == NULL)
131 		bsdar_errc(bsdar, EX_SOFTWARE, errno, "malloc failed");
132 	if ((obj->fd = open(name, O_RDONLY, 0)) < 0) {
133 		bsdar_warnc(bsdar, errno, "can't open file: %s", name);
134 		free(obj);
135 		return (NULL);
136 	}
137 
138 	if ((bname = basename(name)) == NULL)
139 		bsdar_errc(bsdar, EX_SOFTWARE, errno, "basename failed");
140 	if (bsdar->options & AR_TR && strlen(bname) > _TRUNCATE_LEN) {
141 		if ((obj->name = malloc(_TRUNCATE_LEN + 1)) == NULL)
142 			bsdar_errc(bsdar, EX_SOFTWARE, errno, "malloc failed");
143 		(void)strncpy(obj->name, bname, _TRUNCATE_LEN);
144 		obj->name[_TRUNCATE_LEN] = '\0';
145 	} else
146 		if ((obj->name = strdup(bname)) == NULL)
147 		    bsdar_errc(bsdar, EX_SOFTWARE, errno, "strdup failed");
148 
149 	if (fstat(obj->fd, &sb) < 0) {
150 		bsdar_warnc(bsdar, errno, "can't fstat file: %s", obj->name);
151 		goto giveup;
152 	}
153 	if (!S_ISREG(sb.st_mode)) {
154 		bsdar_warnc(bsdar, 0, "%s is not an ordinary file", obj->name);
155 		goto giveup;
156 	}
157 
158 	/*
159 	 * When option '-u' is specified and member is not newer than the
160 	 * existing one, the replace will not happen. While if mtime == 0,
161 	 * which indicates that this is to "replace a none exist member",
162 	 * the replace will proceed regardless of '-u'.
163 	 */
164 	if (mtime != 0 && bsdar->options & AR_U && sb.st_mtime <= mtime)
165 		goto giveup;
166 
167 	/*
168 	 * When option '-D' is specified, mtime and UID / GID from the file
169 	 * will be replaced with 0, and file mode with 644. This ensures that
170 	 * checksums will match for two archives containing the exact same
171 	 * files.
172 	 */
173 	if (bsdar->options & AR_D) {
174 		obj->uid = 0;
175 		obj->gid = 0;
176 		obj->mtime = 0;
177 		obj->md = S_IFREG | 0644;
178 	} else {
179 		obj->uid = sb.st_uid;
180 		obj->gid = sb.st_gid;
181 		obj->mtime = sb.st_mtime;
182 		obj->md = sb.st_mode;
183 	}
184 	obj->size = sb.st_size;
185 	obj->dev = sb.st_dev;
186 	obj->ino = sb.st_ino;
187 
188 	if (obj->size == 0) {
189 		obj->maddr = NULL;
190 		return (obj);
191 	}
192 
193 	if ((obj->maddr = mmap(NULL, obj->size, PROT_READ,
194 	    MAP_PRIVATE, obj->fd, (off_t)0)) == MAP_FAILED) {
195 		bsdar_warnc(bsdar, errno, "can't mmap file: %s", obj->name);
196 		goto giveup;
197 	}
198 	if (close(obj->fd) < 0)
199 		bsdar_errc(bsdar, EX_SOFTWARE, errno, "close failed: %s",
200 		    obj->name);
201 
202 	return (obj);
203 
204 giveup:
205 	if (close(obj->fd) < 0)
206 		bsdar_errc(bsdar, EX_SOFTWARE, errno, "close failed: %s",
207 		    obj->name);
208 	free(obj->name);
209 	free(obj);
210 	return (NULL);
211 }
212 
213 /*
214  * Free object itself and its associated allocations.
215  */
216 static void
217 free_obj(struct bsdar *bsdar, struct ar_obj *obj)
218 {
219 	if (obj->fd == -1)
220 		free(obj->maddr);
221 	else
222 		if (obj->maddr != NULL && munmap(obj->maddr, obj->size))
223 			bsdar_warnc(bsdar, errno,
224 			    "can't munmap file: %s", obj->name);
225 	free(obj->name);
226 	free(obj);
227 }
228 
229 /*
230  * Insert obj to the tail, or before/after the pos obj.
231  */
232 static void
233 insert_obj(struct bsdar *bsdar, struct ar_obj *obj, struct ar_obj *pos)
234 {
235 	if (obj == NULL)
236 		bsdar_errc(bsdar, EX_SOFTWARE, 0, "try to insert a null obj");
237 
238 	if (pos == NULL || obj == pos)
239 		/*
240 		 * If the object to move happens to be the position obj,
241 		 * or if there is not a pos obj, move it to tail.
242 		 */
243 		goto tail;
244 
245 	if (bsdar->options & AR_B) {
246 		TAILQ_INSERT_BEFORE(pos, obj, objs);
247 		return;
248 	}
249 	if (bsdar->options & AR_A) {
250 		TAILQ_INSERT_AFTER(&bsdar->v_obj, pos, obj, objs);
251 		return;
252 	}
253 
254 tail:
255 	TAILQ_INSERT_TAIL(&bsdar->v_obj, obj, objs);
256 
257 }
258 
259 /*
260  * Read objects from archive into v_obj list. Note that checkargv is
261  * set when read_objs is used to read objects from the target of
262  * ADDLIB command (ar script mode), in this case argv array possibly
263  * specifies the members ADDLIB want.
264  */
265 static void
266 read_objs(struct bsdar *bsdar, const char *archive, int checkargv)
267 {
268 	struct archive		 *a;
269 	struct archive_entry	 *entry;
270 	struct ar_obj		 *obj;
271 	const char		 *name;
272 	const char		 *bname;
273 	char			 *buff;
274 	char			**av;
275 	size_t			  size;
276 	int			  i, r, find;
277 
278 	if ((a = archive_read_new()) == NULL)
279 		bsdar_errc(bsdar, EX_SOFTWARE, 0, "archive_read_new failed");
280 	archive_read_support_format_ar(a);
281 	AC(archive_read_open_filename(a, archive, DEF_BLKSZ));
282 	for (;;) {
283 		r = archive_read_next_header(a, &entry);
284 		if (r == ARCHIVE_FATAL)
285 			bsdar_errc(bsdar, EX_DATAERR, 0, "%s",
286 			    archive_error_string(a));
287 		if (r == ARCHIVE_EOF)
288 			break;
289 		if (r == ARCHIVE_WARN || r == ARCHIVE_RETRY)
290 			bsdar_warnc(bsdar, 0, "%s", archive_error_string(a));
291 		if (r == ARCHIVE_RETRY) {
292 			bsdar_warnc(bsdar, 0, "Retrying...");
293 			continue;
294 		}
295 
296 		name = archive_entry_pathname(entry);
297 
298 		/*
299 		 * skip pseudo members.
300 		 */
301 		if (strcmp(name, "/") == 0 || strcmp(name, "//") == 0)
302 			continue;
303 
304 		/*
305 		 * If checkargv is set, only read those members specified
306 		 * in argv.
307 		 */
308 		if (checkargv && bsdar->argc > 0) {
309 			find = 0;
310 			for(i = 0; i < bsdar->argc; i++) {
311 				av = &bsdar->argv[i];
312 				if (*av == NULL)
313 					continue;
314 				if ((bname = basename(*av)) == NULL)
315 					bsdar_errc(bsdar, EX_SOFTWARE, errno,
316 					    "basename failed");
317 				if (strcmp(bname, name) != 0)
318 					continue;
319 
320 				*av = NULL;
321 				find = 1;
322 				break;
323 			}
324 			if (!find)
325 				continue;
326 		}
327 
328 		size = archive_entry_size(entry);
329 
330 		if (size > 0) {
331 			if ((buff = malloc(size)) == NULL)
332 				bsdar_errc(bsdar, EX_SOFTWARE, errno,
333 				    "malloc failed");
334 			if (archive_read_data(a, buff, size) != (ssize_t)size) {
335 				bsdar_warnc(bsdar, 0, "%s",
336 				    archive_error_string(a));
337 				free(buff);
338 				continue;
339 			}
340 		} else
341 			buff = NULL;
342 
343 		obj = malloc(sizeof(struct ar_obj));
344 		if (obj == NULL)
345 			bsdar_errc(bsdar, EX_SOFTWARE, errno, "malloc failed");
346 		obj->maddr = buff;
347 		if ((obj->name = strdup(name)) == NULL)
348 			bsdar_errc(bsdar, EX_SOFTWARE, errno, "strdup failed");
349 		obj->size = size;
350 		obj->uid = archive_entry_uid(entry);
351 		obj->gid = archive_entry_gid(entry);
352 		obj->md = archive_entry_mode(entry);
353 		obj->mtime = archive_entry_mtime(entry);
354 		obj->dev = 0;
355 		obj->ino = 0;
356 
357 		/*
358 		 * Objects from archive have obj->fd set to -1,
359 		 * for the ease of cleaning up.
360 		 */
361 		obj->fd = -1;
362 		TAILQ_INSERT_TAIL(&bsdar->v_obj, obj, objs);
363 	}
364 	AC(archive_read_close(a));
365 	AC(archive_read_free(a));
366 }
367 
368 /*
369  * Determine the constitution of resulting archive.
370  */
371 static void
372 write_archive(struct bsdar *bsdar, char mode)
373 {
374 	struct ar_obj		 *nobj, *obj, *obj_temp, *pos;
375 	struct stat		  sb;
376 	const char		 *bname;
377 	char			**av;
378 	int			  i;
379 
380 	TAILQ_INIT(&bsdar->v_obj);
381 	nobj = NULL;
382 	pos = NULL;
383 	memset(&sb, 0, sizeof(sb));
384 
385 	/*
386 	 * Test if the specified archive exists, to figure out
387 	 * whether we are creating one here.
388 	 */
389 	if (stat(bsdar->filename, &sb) != 0) {
390 		if (errno != ENOENT) {
391 			bsdar_warnc(bsdar, 0, "stat %s failed",
392 			    bsdar->filename);
393 			return;
394 		}
395 
396 		/* We do not create archive in mode 'd', 'm' and 's'.  */
397 		if (mode != 'r' && mode != 'q') {
398 			bsdar_warnc(bsdar, 0, "%s: no such file",
399 			    bsdar->filename);
400 			return;
401 		}
402 
403 		/* Issue a warning if -c is not specified when creating. */
404 		if (!(bsdar->options & AR_C))
405 			bsdar_warnc(bsdar, 0, "creating %s", bsdar->filename);
406 		goto new_archive;
407 	}
408 
409 	/*
410 	 * First read members from existing archive.
411 	 */
412 	read_objs(bsdar, bsdar->filename, 0);
413 
414 	/*
415 	 * For mode 's', no member will be moved, deleted or replaced.
416 	 */
417 	if (mode == 's')
418 		goto write_objs;
419 
420 	/*
421 	 * For mode 'q', we don't need to adjust existing members either.
422 	 * Also, -a, -b and -i are ignored in this mode. New members are
423 	 * always inserted at tail.
424 	 */
425 	if (mode == 'q')
426 		goto new_archive;
427 
428 	/*
429 	 * Mode 'A' adds the contents of another archive to the tail of
430 	 * current archive. Note that mode 'A' is a special mode for the
431 	 * ADDLIB command of the ar script mode. Currently there is no
432 	 * access to this function from the ar command line mode.
433 	 */
434 	if (mode == 'A') {
435 		/*
436 		 * Read objects from the target archive of ADDLIB command.
437 		 * If there are members specified in argv, read those members
438 		 * only, otherwise the entire archive will be read.
439 		 */
440 		read_objs(bsdar, bsdar->addlib, 1);
441 		goto write_objs;
442 	}
443 
444 	/*
445 	 * Try to find the position member specified by user.
446 	 */
447 	if (bsdar->options & AR_A || bsdar->options & AR_B) {
448 		TAILQ_FOREACH(obj, &bsdar->v_obj, objs) {
449 			if (strcmp(obj->name, bsdar->posarg) == 0) {
450 				pos = obj;
451 				break;
452 			}
453 		}
454 
455 		/*
456 		 * If can't find `pos' specified by user,
457 		 * silently insert objects at tail.
458 		 */
459 		if (pos == NULL)
460 			bsdar->options &= ~(AR_A | AR_B);
461 	}
462 
463 	for (i = 0; i < bsdar->argc; i++) {
464 		av = &bsdar->argv[i];
465 
466 		TAILQ_FOREACH_SAFE(obj, &bsdar->v_obj, objs, obj_temp) {
467 			if ((bname = basename(*av)) == NULL)
468 				bsdar_errc(bsdar, EX_SOFTWARE, errno,
469 				    "basename failed");
470 			if (bsdar->options & AR_TR) {
471 				if (strncmp(bname, obj->name, _TRUNCATE_LEN))
472 					continue;
473 			} else
474 				if (strcmp(bname, obj->name) != 0)
475 					continue;
476 
477 			if (mode == 'r') {
478 				/*
479 				 * if the new member is not qualified
480 				 * to replace the old one, skip it.
481 				 */
482 				nobj = create_obj_from_file(bsdar, *av,
483 				    obj->mtime);
484 				if (nobj == NULL)
485 					goto skip_obj;
486 			}
487 
488 			if (bsdar->options & AR_V)
489 				(void)fprintf(stdout, "%c - %s\n", mode,
490 				    *av);
491 
492 			TAILQ_REMOVE(&bsdar->v_obj, obj, objs);
493 			if (mode == 'd' || mode == 'r')
494 				free_obj(bsdar, obj);
495 
496 			if (mode == 'm')
497 				insert_obj(bsdar, obj, pos);
498 			if (mode == 'r')
499 				insert_obj(bsdar, nobj, pos);
500 
501 		skip_obj:
502 			*av = NULL;
503 			break;
504 		}
505 
506 	}
507 
508 new_archive:
509 	/*
510 	 * When operating in mode 'r', directly add those user specified
511 	 * objects which do not exist in current archive. When operating
512 	 * in mode 'q', all objects specified in command line args are
513 	 * appended to the archive, without comparing with existing ones.
514 	 */
515 	for (i = 0; i < bsdar->argc; i++) {
516 		av = &bsdar->argv[i];
517 		if (*av != NULL && (mode == 'r' || mode == 'q')) {
518 			nobj = create_obj_from_file(bsdar, *av, 0);
519 			if (nobj != NULL)
520 				insert_obj(bsdar, nobj, pos);
521 			if (bsdar->options & AR_V && nobj != NULL)
522 				(void)fprintf(stdout, "a - %s\n", *av);
523 			*av = NULL;
524 		}
525 	}
526 
527 write_objs:
528 	write_objs(bsdar);
529 	write_cleanup(bsdar);
530 }
531 
532 /*
533  * Memory cleaning up.
534  */
535 static void
536 write_cleanup(struct bsdar *bsdar)
537 {
538 	struct ar_obj		*obj, *obj_temp;
539 
540 	TAILQ_FOREACH_SAFE(obj, &bsdar->v_obj, objs, obj_temp) {
541 		TAILQ_REMOVE(&bsdar->v_obj, obj, objs);
542 		free_obj(bsdar, obj);
543 	}
544 
545 	free(bsdar->as);
546 	free(bsdar->s_so);
547 	free(bsdar->s_sn);
548 	bsdar->as = NULL;
549 	bsdar->s_so = NULL;
550 	bsdar->s_sn = NULL;
551 }
552 
553 /*
554  * Wrapper for archive_write_data().
555  */
556 static void
557 write_data(struct bsdar *bsdar, struct archive *a, const void *buf, size_t s)
558 {
559 	if (archive_write_data(a, buf, s) != (ssize_t)s)
560 		bsdar_errc(bsdar, EX_SOFTWARE, 0, "%s",
561 		    archive_error_string(a));
562 }
563 
564 /*
565  * Write the resulting archive members.
566  */
567 static void
568 write_objs(struct bsdar *bsdar)
569 {
570 	struct ar_obj		*obj;
571 	struct archive		*a;
572 	struct archive_entry	*entry;
573 	size_t s_sz;		/* size of archive symbol table. */
574 	size_t pm_sz;		/* size of pseudo members */
575 	int			 i, nr;
576 
577 	if (elf_version(EV_CURRENT) == EV_NONE)
578 		bsdar_errc(bsdar, EX_SOFTWARE, 0,
579 		    "ELF library initialization failed: %s", elf_errmsg(-1));
580 
581 	bsdar->rela_off = 0;
582 
583 	/* Create archive symbol table and archive string table, if need. */
584 	TAILQ_FOREACH(obj, &bsdar->v_obj, objs) {
585 		if (!(bsdar->options & AR_SS) && obj->maddr != NULL)
586 			create_symtab_entry(bsdar, obj->maddr, obj->size);
587 		if (strlen(obj->name) > _MAXNAMELEN_SVR4)
588 			add_to_ar_str_table(bsdar, obj->name);
589 		bsdar->rela_off += _ARHDR_LEN + obj->size + obj->size % 2;
590 	}
591 
592 	/*
593 	 * Pad the symbol name string table. It is treated specially because
594 	 * symbol name table should be padded by a '\0', not the common '\n'
595 	 * for other members. The size of sn table includes the pad bit.
596 	 */
597 	if (bsdar->s_cnt != 0 && bsdar->s_sn_sz % 2 != 0)
598 		bsdar->s_sn[bsdar->s_sn_sz++] = '\0';
599 
600 	/*
601 	 * Archive string table is padded by a "\n" as the normal members.
602 	 * The difference is that the size of archive string table counts
603 	 * in the pad bit, while normal members' size fileds do not.
604 	 */
605 	if (bsdar->as != NULL && bsdar->as_sz % 2 != 0)
606 		bsdar->as[bsdar->as_sz++] = '\n';
607 
608 	/*
609 	 * If there is a symbol table, calculate the size of pseudo members,
610 	 * convert previously stored relative offsets to absolute ones, and
611 	 * then make them Big Endian.
612 	 *
613 	 * absolute_offset = htobe32(relative_offset + size_of_pseudo_members)
614 	 */
615 
616 	if (bsdar->s_cnt != 0) {
617 		s_sz = (bsdar->s_cnt + 1) * sizeof(uint32_t) + bsdar->s_sn_sz;
618 		pm_sz = _ARMAG_LEN + (_ARHDR_LEN + s_sz);
619 		if (bsdar->as != NULL)
620 			pm_sz += _ARHDR_LEN + bsdar->as_sz;
621 		for (i = 0; (size_t)i < bsdar->s_cnt; i++)
622 			*(bsdar->s_so + i) = htobe32(*(bsdar->s_so + i) +
623 			    pm_sz);
624 	}
625 
626 	if ((a = archive_write_new()) == NULL)
627 		bsdar_errc(bsdar, EX_SOFTWARE, 0, "archive_write_new failed");
628 
629 	archive_write_set_format_ar_svr4(a);
630 
631 	AC(archive_write_open_filename(a, bsdar->filename));
632 
633 	/*
634 	 * write the archive symbol table, if there is one.
635 	 * If options -s is explicitly specified or we are invoked
636 	 * as ranlib, write the symbol table even if it is empty.
637 	 */
638 	if ((bsdar->s_cnt != 0 && !(bsdar->options & AR_SS)) ||
639 	    bsdar->options & AR_S) {
640 		entry = archive_entry_new();
641 		archive_entry_copy_pathname(entry, "/");
642 		if ((bsdar->options & AR_D) == 0)
643 			archive_entry_set_mtime(entry, time(NULL), 0);
644 		archive_entry_set_size(entry, (bsdar->s_cnt + 1) *
645 		    sizeof(uint32_t) + bsdar->s_sn_sz);
646 		AC(archive_write_header(a, entry));
647 		nr = htobe32(bsdar->s_cnt);
648 		write_data(bsdar, a, &nr, sizeof(uint32_t));
649 		write_data(bsdar, a, bsdar->s_so, sizeof(uint32_t) *
650 		    bsdar->s_cnt);
651 		write_data(bsdar, a, bsdar->s_sn, bsdar->s_sn_sz);
652 		archive_entry_free(entry);
653 	}
654 
655 	/* write the archive string table, if any. */
656 	if (bsdar->as != NULL) {
657 		entry = archive_entry_new();
658 		archive_entry_copy_pathname(entry, "//");
659 		archive_entry_set_size(entry, bsdar->as_sz);
660 		AC(archive_write_header(a, entry));
661 		write_data(bsdar, a, bsdar->as, bsdar->as_sz);
662 		archive_entry_free(entry);
663 	}
664 
665 	/* write normal members. */
666 	TAILQ_FOREACH(obj, &bsdar->v_obj, objs) {
667 		entry = archive_entry_new();
668 		archive_entry_copy_pathname(entry, obj->name);
669 		archive_entry_set_uid(entry, obj->uid);
670 		archive_entry_set_gid(entry, obj->gid);
671 		archive_entry_set_mode(entry, obj->md);
672 		archive_entry_set_size(entry, obj->size);
673 		archive_entry_set_mtime(entry, obj->mtime, 0);
674 		archive_entry_set_dev(entry, obj->dev);
675 		archive_entry_set_ino(entry, obj->ino);
676 		archive_entry_set_filetype(entry, AE_IFREG);
677 		AC(archive_write_header(a, entry));
678 		write_data(bsdar, a, obj->maddr, obj->size);
679 		archive_entry_free(entry);
680 	}
681 
682 	AC(archive_write_close(a));
683 	AC(archive_write_free(a));
684 }
685 
686 /*
687  * Extract global symbols from ELF binary members.
688  */
689 static void
690 create_symtab_entry(struct bsdar *bsdar, void *maddr, size_t size)
691 {
692 	Elf		*e;
693 	Elf_Scn		*scn;
694 	GElf_Shdr	 shdr;
695 	GElf_Sym	 sym;
696 	Elf_Data	*data;
697 	char		*name;
698 	size_t		 n, shstrndx;
699 	int		 elferr, tabndx, len, i;
700 
701 	if ((e = elf_memory(maddr, size)) == NULL) {
702 		bsdar_warnc(bsdar, 0, "elf_memory() failed: %s",
703 		     elf_errmsg(-1));
704 		return;
705 	}
706 	if (elf_kind(e) != ELF_K_ELF) {
707 		/* Silently ignore non-elf member. */
708 		elf_end(e);
709 		return;
710 	}
711 	if (elf_getshstrndx(e, &shstrndx) == 0) {
712 		bsdar_warnc(bsdar, EX_SOFTWARE, 0, "elf_getshstrndx failed: %s",
713 		     elf_errmsg(-1));
714 		elf_end(e);
715 		return;
716 	}
717 
718 	tabndx = -1;
719 	scn = NULL;
720 	while ((scn = elf_nextscn(e, scn)) != NULL) {
721 		if (gelf_getshdr(scn, &shdr) != &shdr) {
722 			bsdar_warnc(bsdar, 0,
723 			    "elf_getshdr failed: %s", elf_errmsg(-1));
724 			continue;
725 		}
726 		if ((name = elf_strptr(e, shstrndx, shdr.sh_name)) == NULL) {
727 			bsdar_warnc(bsdar, 0,
728 			    "elf_strptr failed: %s", elf_errmsg(-1));
729 			continue;
730 		}
731 		if (strcmp(name, ".strtab") == 0) {
732 			tabndx = elf_ndxscn(scn);
733 			break;
734 		}
735 	}
736 	elferr = elf_errno();
737 	if (elferr != 0)
738 		bsdar_warnc(bsdar, 0, "elf_nextscn failed: %s",
739 		     elf_errmsg(elferr));
740 	if (tabndx == -1) {
741 		bsdar_warnc(bsdar, 0, "can't find .strtab section");
742 		elf_end(e);
743 		return;
744 	}
745 
746 	scn = NULL;
747 	while ((scn = elf_nextscn(e, scn)) != NULL) {
748 		if (gelf_getshdr(scn, &shdr) != &shdr) {
749 			bsdar_warnc(bsdar, EX_SOFTWARE, 0,
750 			    "elf_getshdr failed: %s", elf_errmsg(-1));
751 			continue;
752 		}
753 		if (shdr.sh_type != SHT_SYMTAB)
754 			continue;
755 
756 		data = NULL;
757 		n = 0;
758 		while (n < shdr.sh_size &&
759 		    (data = elf_getdata(scn, data)) != NULL) {
760 			len = data->d_size / shdr.sh_entsize;
761 			for (i = 0; i < len; i++) {
762 				if (gelf_getsym(data, i, &sym) != &sym) {
763 					bsdar_warnc(bsdar, EX_SOFTWARE, 0,
764 					    "gelf_getsym failed: %s",
765 					     elf_errmsg(-1));
766 					continue;
767 				}
768 
769 				/* keep only global or weak symbols */
770 				if (GELF_ST_BIND(sym.st_info) != STB_GLOBAL &&
771 				    GELF_ST_BIND(sym.st_info) != STB_WEAK)
772 					continue;
773 
774 				/* keep only defined symbols */
775 				if (sym.st_shndx == SHN_UNDEF)
776 					continue;
777 
778 				if ((name = elf_strptr(e, tabndx,
779 				    sym.st_name)) == NULL) {
780 					bsdar_warnc(bsdar, EX_SOFTWARE, 0,
781 					    "elf_strptr failed: %s",
782 					     elf_errmsg(-1));
783 					continue;
784 				}
785 
786 				add_to_ar_sym_table(bsdar, name);
787 			}
788 		}
789 	}
790 	elferr = elf_errno();
791 	if (elferr != 0)
792 		bsdar_warnc(bsdar, EX_SOFTWARE, 0, "elf_nextscn failed: %s",
793 		     elf_errmsg(elferr));
794 
795 	elf_end(e);
796 }
797 
798 /*
799  * Append to the archive string table buffer.
800  */
801 static void
802 add_to_ar_str_table(struct bsdar *bsdar, const char *name)
803 {
804 
805 	if (bsdar->as == NULL) {
806 		bsdar->as_cap = _INIT_AS_CAP;
807 		bsdar->as_sz = 0;
808 		if ((bsdar->as = malloc(bsdar->as_cap)) == NULL)
809 			bsdar_errc(bsdar, EX_SOFTWARE, errno, "malloc failed");
810 	}
811 
812 	/*
813 	 * The space required for holding one member name in as table includes:
814 	 * strlen(name) + (1 for '/') + (1 for '\n') + (possibly 1 for padding).
815 	 */
816 	while (bsdar->as_sz + strlen(name) + 3 > bsdar->as_cap) {
817 		bsdar->as_cap *= 2;
818 		bsdar->as = realloc(bsdar->as, bsdar->as_cap);
819 		if (bsdar->as == NULL)
820 			bsdar_errc(bsdar, EX_SOFTWARE, errno, "realloc failed");
821 	}
822 	strncpy(&bsdar->as[bsdar->as_sz], name, strlen(name));
823 	bsdar->as_sz += strlen(name);
824 	bsdar->as[bsdar->as_sz++] = '/';
825 	bsdar->as[bsdar->as_sz++] = '\n';
826 }
827 
828 /*
829  * Append to the archive symbol table buffer.
830  */
831 static void
832 add_to_ar_sym_table(struct bsdar *bsdar, const char *name)
833 {
834 
835 	if (bsdar->s_so == NULL) {
836 		if ((bsdar->s_so = malloc(_INIT_SYMOFF_CAP)) ==
837 		    NULL)
838 			bsdar_errc(bsdar, EX_SOFTWARE, errno, "malloc failed");
839 		bsdar->s_so_cap = _INIT_SYMOFF_CAP;
840 		bsdar->s_cnt = 0;
841 	}
842 
843 	if (bsdar->s_sn == NULL) {
844 		if ((bsdar->s_sn = malloc(_INIT_SYMNAME_CAP)) == NULL)
845 			bsdar_errc(bsdar, EX_SOFTWARE, errno, "malloc failed");
846 		bsdar->s_sn_cap = _INIT_SYMNAME_CAP;
847 		bsdar->s_sn_sz = 0;
848 	}
849 
850 	if (bsdar->s_cnt * sizeof(uint32_t) >= bsdar->s_so_cap) {
851 		bsdar->s_so_cap *= 2;
852 		bsdar->s_so = realloc(bsdar->s_so, bsdar->s_so_cap);
853 		if (bsdar->s_so == NULL)
854 			bsdar_errc(bsdar, EX_SOFTWARE, errno, "realloc failed");
855 	}
856 	bsdar->s_so[bsdar->s_cnt] = bsdar->rela_off;
857 	bsdar->s_cnt++;
858 
859 	/*
860 	 * The space required for holding one symbol name in sn table includes:
861 	 * strlen(name) + (1 for '\n') + (possibly 1 for padding).
862 	 */
863 	while (bsdar->s_sn_sz + strlen(name) + 2 > bsdar->s_sn_cap) {
864 		bsdar->s_sn_cap *= 2;
865 		bsdar->s_sn = realloc(bsdar->s_sn, bsdar->s_sn_cap);
866 		if (bsdar->s_sn == NULL)
867 			bsdar_errc(bsdar, EX_SOFTWARE, errno, "realloc failed");
868 	}
869 	strncpy(&bsdar->s_sn[bsdar->s_sn_sz], name, strlen(name));
870 	bsdar->s_sn_sz += strlen(name);
871 	bsdar->s_sn[bsdar->s_sn_sz++] = '\0';
872 }
873