xref: /freebsd/contrib/libarchive/tar/util.c (revision 007679a138089676aadc9a712277f4004403b905)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2003-2007 Tim Kientzle
5  * All rights reserved.
6  */
7 
8 #include "bsdtar_platform.h"
9 
10 #ifdef HAVE_SYS_STAT_H
11 #include <sys/stat.h>
12 #endif
13 #ifdef HAVE_SYS_TYPES_H
14 #include <sys/types.h>  /* Linux doesn't define mode_t, etc. in sys/stat.h. */
15 #endif
16 #include <ctype.h>
17 #ifdef HAVE_ERRNO_H
18 #include <errno.h>
19 #endif
20 #ifdef HAVE_IO_H
21 #include <io.h>
22 #endif
23 #ifdef HAVE_STDARG_H
24 #include <stdarg.h>
25 #endif
26 #ifdef HAVE_STDINT_H
27 #include <stdint.h>
28 #endif
29 #include <stdio.h>
30 #ifdef HAVE_STDLIB_H
31 #include <stdlib.h>
32 #endif
33 #ifdef HAVE_STRING_H
34 #include <string.h>
35 #endif
36 #ifdef HAVE_WCTYPE_H
37 #include <wctype.h>
38 #else
39 /* If we don't have wctype, we need to hack up some version of iswprint(). */
40 #define	iswprint isprint
41 #endif
42 
43 #include "bsdtar.h"
44 #include "lafe_err.h"
45 #include "passphrase.h"
46 
47 static size_t	bsdtar_expand_char(char *, size_t, size_t, char);
48 static const char *strip_components(const char *path, int elements);
49 
50 #if defined(_WIN32) && !defined(__CYGWIN__)
51 #define	read _read
52 #endif
53 
54 /* TODO:  Hack up a version of mbtowc for platforms with no wide
55  * character support at all.  I think the following might suffice,
56  * but it needs careful testing.
57  * #if !HAVE_MBTOWC
58  * #define	mbtowc(wcp, p, n) ((*wcp = *p), 1)
59  * #endif
60  */
61 
62 /*
63  * Print a string, taking care with any non-printable characters.
64  *
65  * Note that we use a stack-allocated buffer to receive the formatted
66  * string if we can.  This is partly performance (avoiding a call to
67  * malloc()), partly out of expedience (we have to call vsnprintf()
68  * before malloc() anyway to find out how big a buffer we need; we may
69  * as well point that first call at a small local buffer in case it
70  * works).
71  */
72 
73 void
safe_fprintf(FILE * restrict f,const char * restrict fmt,...)74 safe_fprintf(FILE * restrict f, const char * restrict fmt, ...)
75 {
76 	char fmtbuff_stack[256]; /* Place to format the printf() string. */
77 	char outbuff[256]; /* Buffer for outgoing characters. */
78 	char *fmtbuff_heap; /* If fmtbuff_stack is too small, we use malloc */
79 	char *fmtbuff;  /* Pointer to fmtbuff_stack or fmtbuff_heap. */
80 	size_t fmtbuff_length;
81 	int length, n;
82 	va_list ap;
83 	const char *p;
84 	size_t i;
85 	wchar_t wc;
86 	char try_wc;
87 
88 	/* Use a stack-allocated buffer if we can, for speed and safety. */
89 	memset(fmtbuff_stack, '\0', sizeof(fmtbuff_stack));
90 	fmtbuff_heap = NULL;
91 	fmtbuff_length = sizeof(fmtbuff_stack);
92 	fmtbuff = fmtbuff_stack;
93 
94 	/* Try formatting into the stack buffer. */
95 	va_start(ap, fmt);
96 	length = vsnprintf(fmtbuff, fmtbuff_length, fmt, ap);
97 	va_end(ap);
98 
99 	/* If vsnprintf will always fail, stop early. */
100 	if (length < 0 && errno == EOVERFLOW)
101 		return;
102 
103 	/* If the result was too large, allocate a buffer on the heap. */
104 	while (length < 0 || (size_t)length >= fmtbuff_length) {
105 		if (length >= 0 && (size_t)length >= fmtbuff_length)
106 			fmtbuff_length = (size_t)length + 1;
107 		else if (fmtbuff_length < 8192)
108 			fmtbuff_length *= 2;
109 		else if (fmtbuff_length < 1000000)
110 			fmtbuff_length += fmtbuff_length / 4;
111 		else {
112 			fmtbuff[fmtbuff_length - 1] = '\0';
113 			length = (int)strlen(fmtbuff);
114 			break;
115 		}
116 		free(fmtbuff_heap);
117 		fmtbuff_heap = malloc(fmtbuff_length);
118 
119 		/* Reformat the result into the heap buffer if we can. */
120 		if (fmtbuff_heap != NULL) {
121 			fmtbuff = fmtbuff_heap;
122 			va_start(ap, fmt);
123 			length = vsnprintf(fmtbuff, fmtbuff_length, fmt, ap);
124 			va_end(ap);
125 		} else {
126 			/* Leave fmtbuff pointing to the truncated
127 			 * string in fmtbuff_stack. */
128 			fmtbuff_stack[sizeof(fmtbuff_stack) - 1] = '\0';
129 			fmtbuff = fmtbuff_stack;
130 			length = (int)strlen(fmtbuff);
131 			break;
132 		}
133 	}
134 
135 	/* Note: mbrtowc() has a cleaner API, but mbtowc() seems a bit
136 	 * more portable, so we use that here instead. */
137 	if (mbtowc(NULL, NULL, 1) == -1) { /* Reset the shift state. */
138 		/* mbtowc() should never fail in practice, but
139 		 * handle the theoretical error anyway. */
140 		free(fmtbuff_heap);
141 		return;
142 	}
143 
144 	/* Write data, expanding unprintable characters. */
145 	p = fmtbuff;
146 	i = 0;
147 	try_wc = 1;
148 	while (*p != '\0') {
149 
150 		/* Convert to wide char, test if the wide
151 		 * char is printable in the current locale. */
152 		if (try_wc && (n = mbtowc(&wc, p, length)) != -1) {
153 			length -= n;
154 			if (iswprint(wc) && wc != L'\\') {
155 				/* Printable, copy the bytes through. */
156 				while (n-- > 0)
157 					outbuff[i++] = *p++;
158 			} else {
159 				/* Not printable, format the bytes. */
160 				while (n-- > 0)
161 					i += bsdtar_expand_char(
162 					    outbuff, sizeof(outbuff), i, *p++);
163 			}
164 		} else {
165 			/* After any conversion failure, don't bother
166 			 * trying to convert the rest. */
167 			i += bsdtar_expand_char(outbuff, sizeof(outbuff), i, *p++);
168 			try_wc = 0;
169 		}
170 
171 		/* If our output buffer is full, dump it and keep going. */
172 		if (i > (sizeof(outbuff) - 128)) {
173 			outbuff[i] = '\0';
174 			fprintf(f, "%s", outbuff);
175 			i = 0;
176 		}
177 	}
178 	outbuff[i] = '\0';
179 	fprintf(f, "%s", outbuff);
180 
181 	/* If we allocated a heap-based formatting buffer, free it now. */
182 	free(fmtbuff_heap);
183 }
184 
185 /*
186  * Render an arbitrary sequence of bytes into printable ASCII characters.
187  */
188 static size_t
bsdtar_expand_char(char * buff,size_t buffsize,size_t offset,char c)189 bsdtar_expand_char(char *buff, size_t buffsize, size_t offset, char c)
190 {
191 	size_t i = offset;
192 
193 	if (isprint((unsigned char)c) && c != '\\')
194 		buff[i++] = c;
195 	else {
196 		buff[i++] = '\\';
197 		switch (c) {
198 		case '\a': buff[i++] = 'a'; break;
199 		case '\b': buff[i++] = 'b'; break;
200 		case '\f': buff[i++] = 'f'; break;
201 		case '\n': buff[i++] = 'n'; break;
202 #if '\r' != '\n'
203 		/* On some platforms, \n and \r are the same. */
204 		case '\r': buff[i++] = 'r'; break;
205 #endif
206 		case '\t': buff[i++] = 't'; break;
207 		case '\v': buff[i++] = 'v'; break;
208 		case '\\': buff[i++] = '\\'; break;
209 		default:
210 			snprintf(buff + i, buffsize - i, "%03o",
211 			    0xFF & (unsigned int)c);
212 			i += 3;
213 		}
214 	}
215 
216 	return (i - offset);
217 }
218 
219 int
yes(const char * fmt,...)220 yes(const char *fmt, ...)
221 {
222 	char buff[32];
223 	char *p;
224 	ssize_t l;
225 	int read_fd = 2; /* stderr */
226 
227 	va_list ap;
228 	va_start(ap, fmt);
229 	vfprintf(stderr, fmt, ap);
230 	va_end(ap);
231 	fprintf(stderr, " (y/N)? ");
232 	fflush(stderr);
233 
234 #if defined(_WIN32) && !defined(__CYGWIN__)
235 	/* To be resilient when stdin is a pipe, bsdtar prefers to read from
236 	 * stderr.  On Windows, stderr cannot be read. The nearest "piping
237 	 * resilient" equivalent is reopening the console input handle.
238 	 */
239 	read_fd = _open("CONIN$", O_RDONLY);
240 	if (read_fd < 0) {
241 	  fprintf(stderr, "Keyboard read failed\n");
242 	  exit(1);
243 	}
244 #endif
245 
246 	l = read(read_fd, buff, sizeof(buff) - 1);
247 
248 #if defined(_WIN32) && !defined(__CYGWIN__)
249 	_close(read_fd);
250 #endif
251 
252 	if (l < 0) {
253 	  fprintf(stderr, "Keyboard read failed\n");
254 	  exit(1);
255 	}
256 	if (l == 0)
257 		return (0);
258 	buff[l] = 0;
259 
260 	for (p = buff; *p != '\0'; p++) {
261 		if (isspace((unsigned char)*p))
262 			continue;
263 		switch(*p) {
264 		case 'y': case 'Y':
265 			return (1);
266 		case 'n': case 'N':
267 			return (0);
268 		default:
269 			return (0);
270 		}
271 	}
272 
273 	return (0);
274 }
275 
276 /*-
277  * The logic here for -C <dir> attempts to avoid
278  * chdir() as long as possible.  For example:
279  * "-C /foo -C /bar file"          needs chdir("/bar") but not chdir("/foo")
280  * "-C /foo -C bar file"           needs chdir("/foo/bar")
281  * "-C /foo -C bar /file1"         does not need chdir()
282  * "-C /foo -C bar /file1 file2"   needs chdir("/foo/bar") before file2
283  *
284  * The only correct way to handle this is to record a "pending" chdir
285  * request and combine multiple requests intelligently until we
286  * need to process a non-absolute file.  set_chdir() adds the new dir
287  * to the pending list; do_chdir() actually executes any pending chdir.
288  *
289  * This way, programs that build tar command lines don't have to worry
290  * about -C with non-existent directories; such requests will only
291  * fail if the directory must be accessed.
292  *
293  */
294 void
set_chdir(struct bsdtar * bsdtar,const char * newdir)295 set_chdir(struct bsdtar *bsdtar, const char *newdir)
296 {
297 #if defined(_WIN32) && !defined(__CYGWIN__)
298 	if (newdir[0] == '/' || newdir[0] == '\\' ||
299 	    /* Detect this type, for example, "C:\" or "C:/" */
300 	    (((newdir[0] >= 'a' && newdir[0] <= 'z') ||
301 	      (newdir[0] >= 'A' && newdir[0] <= 'Z')) &&
302 	    newdir[1] == ':' && (newdir[2] == '/' || newdir[2] == '\\'))) {
303 #else
304 	if (newdir[0] == '/') {
305 #endif
306 		/* The -C /foo -C /bar case; dump first one. */
307 		free(bsdtar->pending_chdir);
308 		bsdtar->pending_chdir = NULL;
309 	}
310 	if (bsdtar->pending_chdir == NULL)
311 		/* Easy case: no previously-saved dir. */
312 		bsdtar->pending_chdir = strdup(newdir);
313 	else {
314 		/* The -C /foo -C bar case; concatenate */
315 		char *old_pending = bsdtar->pending_chdir;
316 		size_t old_len = strlen(old_pending);
317 		size_t newdir_len = strlen(newdir);
318 		size_t new_len = old_len + newdir_len + 2;
319 		if (old_len > SIZE_MAX - newdir_len - 2)
320 		    lafe_errc(1, errno, "Path too long");
321 		bsdtar->pending_chdir = malloc(new_len);
322 		if (old_pending[old_len - 1] == '/')
323 			old_pending[old_len - 1] = '\0';
324 		if (bsdtar->pending_chdir != NULL)
325 			snprintf(bsdtar->pending_chdir, new_len, "%s/%s",
326 			    old_pending, newdir);
327 		free(old_pending);
328 	}
329 	if (bsdtar->pending_chdir == NULL)
330 		lafe_errc(1, errno, "No memory");
331 }
332 
333 void
334 do_chdir(struct bsdtar *bsdtar)
335 {
336 	if (bsdtar->pending_chdir == NULL)
337 		return;
338 
339 	if (chdir(bsdtar->pending_chdir) != 0) {
340 		lafe_errc(1, 0, "could not chdir to '%s'",
341 		    bsdtar->pending_chdir);
342 	}
343 	free(bsdtar->pending_chdir);
344 	bsdtar->pending_chdir = NULL;
345 }
346 
347 static const char *
348 strip_components(const char *p, int elements)
349 {
350 	/* Skip as many elements as necessary. */
351 	while (elements > 0) {
352 		switch (*p++) {
353 		case '/':
354 #if defined(_WIN32) && !defined(__CYGWIN__)
355 		case '\\': /* Support \ path sep on Windows ONLY. */
356 #endif
357 			elements--;
358 			break;
359 		case '\0':
360 			/* Path is too short, skip it. */
361 			return (NULL);
362 		}
363 	}
364 
365 	/* Skip any / characters.  This handles short paths that have
366 	 * additional / termination.  This also handles the case where
367 	 * the logic above stops in the middle of a duplicate //
368 	 * sequence (which would otherwise get converted to an
369 	 * absolute path). */
370 	for (;;) {
371 		switch (*p) {
372 		case '/':
373 #if defined(_WIN32) && !defined(__CYGWIN__)
374 		case '\\': /* Support \ path sep on Windows ONLY. */
375 #endif
376 			++p;
377 			break;
378 		case '\0':
379 			return (NULL);
380 		default:
381 			return (p);
382 		}
383 	}
384 }
385 
386 static void
387 warn_strip_leading_char(struct bsdtar *bsdtar, const char *c)
388 {
389 	if (!bsdtar->warned_lead_slash) {
390 		lafe_warnc(0,
391 			   "Removing leading '%c' from member names",
392 			   c[0]);
393 		bsdtar->warned_lead_slash = 1;
394 	}
395 }
396 
397 static void
398 warn_strip_drive_letter(struct bsdtar *bsdtar)
399 {
400 	if (!bsdtar->warned_lead_slash) {
401 		lafe_warnc(0,
402 			   "Removing leading drive letter from "
403 			   "member names");
404 		bsdtar->warned_lead_slash = 1;
405 	}
406 }
407 
408 /*
409  * Convert absolute path to non-absolute path by skipping leading
410  * absolute path prefixes.
411  */
412 static const char*
413 strip_absolute_path(struct bsdtar *bsdtar, const char *p)
414 {
415 	const char *rp;
416 
417 	/* Remove leading "//./" or "//?/" or "//?/UNC/"
418 	 * (absolute path prefixes used by Windows API) */
419 	if ((p[0] == '/' || p[0] == '\\') &&
420 	    (p[1] == '/' || p[1] == '\\') &&
421 	    (p[2] == '.' || p[2] == '?') &&
422 	    (p[3] == '/' || p[3] == '\\'))
423 	{
424 		if (p[2] == '?' &&
425 		    (p[4] == 'U' || p[4] == 'u') &&
426 		    (p[5] == 'N' || p[5] == 'n') &&
427 		    (p[6] == 'C' || p[6] == 'c') &&
428 		    (p[7] == '/' || p[7] == '\\'))
429 			p += 8;
430 		else
431 			p += 4;
432 		warn_strip_drive_letter(bsdtar);
433 	}
434 
435 	/* Remove multiple leading slashes and Windows drive letters. */
436 	do {
437 		rp = p;
438 		if (((p[0] >= 'a' && p[0] <= 'z') ||
439 		     (p[0] >= 'A' && p[0] <= 'Z')) &&
440 		    p[1] == ':') {
441 			p += 2;
442 			warn_strip_drive_letter(bsdtar);
443 		}
444 
445 		/* Remove leading "/../", "/./", "//", etc. */
446 		while (p[0] == '/' || p[0] == '\\') {
447 			if (p[1] == '.' &&
448 			    p[2] == '.' &&
449 			    (p[3] == '/' || p[3] == '\\')) {
450 				p += 3; /* Remove "/..", leave "/" for next pass. */
451 			} else if (p[1] == '.' &&
452 				   (p[2] == '/' || p[2] == '\\')) {
453 				p += 2; /* Remove "/.", leave "/" for next pass. */
454 			} else
455 				p += 1; /* Remove "/". */
456 			warn_strip_leading_char(bsdtar, rp);
457 		}
458 	} while (rp != p);
459 
460 	return (p);
461 }
462 
463 /*
464  * Handle --strip-components and any future path-rewriting options.
465  * Returns non-zero if the pathname should not be extracted.
466  *
467  * Note: The rewrites are applied uniformly to pathnames and hardlink
468  * names but not to symlink bodies.  This is deliberate: Symlink
469  * bodies are not necessarily filenames.  Even when they are, they
470  * need to be interpreted relative to the directory containing them,
471  * so simple rewrites like this are rarely appropriate.
472  *
473  * TODO: Support pax-style regex path rewrites.
474  */
475 int
476 edit_pathname(struct bsdtar *bsdtar, struct archive_entry *entry)
477 {
478 	const char *name = archive_entry_pathname(entry);
479 	const char *original_name = name;
480 	const char *hardlinkname = archive_entry_hardlink(entry);
481 	const char *original_hardlinkname = hardlinkname;
482 #if defined(HAVE_REGEX_H) || defined(HAVE_PCREPOSIX_H) || defined(HAVE_PCRE2POSIX_H)
483 	char *subst_name;
484 	int r;
485 
486 	/* Apply user-specified substitution to pathname. */
487 	r = apply_substitution(bsdtar, name, &subst_name, 0, 0);
488 	if (r == -1) {
489 		lafe_warnc(0, "Invalid substitution, skipping entry");
490 		return 1;
491 	}
492 	if (r == 1) {
493 		archive_entry_copy_pathname(entry, subst_name);
494 		if (*subst_name == '\0') {
495 			free(subst_name);
496 			return -1;
497 		} else
498 			free(subst_name);
499 		name = archive_entry_pathname(entry);
500 		original_name = name;
501 	}
502 
503 	/* Apply user-specified substitution to hardlink target. */
504 	if (hardlinkname != NULL) {
505 		r = apply_substitution(bsdtar, hardlinkname, &subst_name, 0, 1);
506 		if (r == -1) {
507 			lafe_warnc(0, "Invalid substitution, skipping entry");
508 			return 1;
509 		}
510 		if (r == 1) {
511 			archive_entry_copy_hardlink(entry, subst_name);
512 			free(subst_name);
513 		}
514 		hardlinkname = archive_entry_hardlink(entry);
515 		original_hardlinkname = hardlinkname;
516 	}
517 
518 	/* Apply user-specified substitution to symlink body. */
519 	if (archive_entry_symlink(entry) != NULL) {
520 		r = apply_substitution(bsdtar, archive_entry_symlink(entry), &subst_name, 1, 0);
521 		if (r == -1) {
522 			lafe_warnc(0, "Invalid substitution, skipping entry");
523 			return 1;
524 		}
525 		if (r == 1) {
526 			archive_entry_copy_symlink(entry, subst_name);
527 			free(subst_name);
528 		}
529 	}
530 #endif
531 
532 	/* Strip leading dir names as per --strip-components option. */
533 	if (bsdtar->strip_components > 0) {
534 		name = strip_components(name, bsdtar->strip_components);
535 		if (name == NULL)
536 			return (1);
537 
538 		if (hardlinkname != NULL) {
539 			hardlinkname = strip_components(hardlinkname,
540 			    bsdtar->strip_components);
541 			if (hardlinkname == NULL)
542 				return (1);
543 		}
544 	}
545 
546 	if ((bsdtar->flags & OPTFLAG_ABSOLUTE_PATHS) == 0) {
547 		/* By default, don't write or restore absolute pathnames. */
548 		name = strip_absolute_path(bsdtar, name);
549 		if (*name == '\0')
550 			name = ".";
551 
552 		if (hardlinkname != NULL) {
553 			hardlinkname = strip_absolute_path(bsdtar, hardlinkname);
554 			if (*hardlinkname == '\0')
555 				return (1);
556 		}
557 	} else {
558 		/* Strip redundant leading '/' characters. */
559 		while (name[0] == '/' && name[1] == '/')
560 			name++;
561 	}
562 
563 	/* Replace name in archive_entry. */
564 	if (name != original_name) {
565 		archive_entry_copy_pathname(entry, name);
566 	}
567 	if (hardlinkname != original_hardlinkname) {
568 		archive_entry_copy_hardlink(entry, hardlinkname);
569 	}
570 	return (0);
571 }
572 
573 /*
574  * Apply --mtime and --clamp-mtime options.
575  */
576 void
577 edit_mtime(struct bsdtar *bsdtar, struct archive_entry *entry)
578 {
579 	if (!bsdtar->has_mtime)
580 		return;
581 
582 	__LA_TIME_T entry_mtime = archive_entry_mtime(entry);
583 	if (!bsdtar->clamp_mtime || entry_mtime > bsdtar->mtime)
584 		archive_entry_set_mtime(entry, bsdtar->mtime, 0);
585 }
586 
587 /*
588  * It would be nice to just use printf() for formatting large numbers,
589  * but the compatibility problems are quite a headache.  Hence the
590  * following simple utility function.
591  */
592 const char *
593 tar_i64toa(int64_t n0)
594 {
595 	static char buff[24];
596 	uint64_t n = n0 < 0 ? -n0 : n0;
597 	char *p = buff + sizeof(buff);
598 
599 	*--p = '\0';
600 	do {
601 		*--p = '0' + (int)(n % 10);
602 	} while (n /= 10);
603 	if (n0 < 0)
604 		*--p = '-';
605 	return p;
606 }
607 
608 /*
609  * Like strcmp(), but try to be a little more aware of the fact that
610  * we're comparing two paths.  Right now, it just handles leading
611  * "./" and trailing '/' specially, so that "a/b/" == "./a/b"
612  *
613  * TODO: Make this better, so that "./a//b/./c/" == "a/b/c"
614  * TODO: After this works, push it down into libarchive.
615  * TODO: Publish the path normalization routines in libarchive so
616  * that bsdtar can normalize paths and use fast strcmp() instead
617  * of this.
618  *
619  * Note: This is currently only used within write.c, so should
620  * not handle \ path separators.
621  */
622 
623 int
624 pathcmp(const char *a, const char *b)
625 {
626 	/* Skip leading './' */
627 	if (a[0] == '.' && a[1] == '/' && a[2] != '\0')
628 		a += 2;
629 	if (b[0] == '.' && b[1] == '/' && b[2] != '\0')
630 		b += 2;
631 	/* Find the first difference, or return (0) if none. */
632 	while (*a == *b) {
633 		if (*a == '\0')
634 			return (0);
635 		a++;
636 		b++;
637 	}
638 	/*
639 	 * If one ends in '/' and the other one doesn't,
640 	 * they're the same.
641 	 */
642 	if (a[0] == '/' && a[1] == '\0' && b[0] == '\0')
643 		return (0);
644 	if (a[0] == '\0' && b[0] == '/' && b[1] == '\0')
645 		return (0);
646 	/* They're really different, return the correct sign. */
647 	return (*(const unsigned char *)a - *(const unsigned char *)b);
648 }
649 
650 #define PPBUFF_SIZE 1024
651 const char *
652 passphrase_callback(struct archive *a, void *_client_data)
653 {
654 	struct bsdtar *bsdtar = (struct bsdtar *)_client_data;
655 	(void)a; /* UNUSED */
656 
657 	if (bsdtar->ppbuff == NULL) {
658 		bsdtar->ppbuff = malloc(PPBUFF_SIZE);
659 		if (bsdtar->ppbuff == NULL)
660 			lafe_errc(1, errno, "Out of memory");
661 	}
662 	return lafe_readpassphrase("Enter passphrase:",
663 		bsdtar->ppbuff, PPBUFF_SIZE);
664 }
665 
666 void
667 passphrase_free(char *ppbuff)
668 {
669 	if (ppbuff != NULL) {
670 		memset(ppbuff, 0, PPBUFF_SIZE);
671 		free(ppbuff);
672 	}
673 }
674 
675 /*
676  * Display information about the current file.
677  *
678  * The format here roughly duplicates the output of 'ls -l'.
679  * This is based on SUSv2, where 'tar tv' is documented as
680  * listing additional information in an "unspecified format,"
681  * and 'pax -l' is documented as using the same format as 'ls -l'.
682  */
683 void
684 list_item_verbose(struct bsdtar *bsdtar, FILE *out, struct archive_entry *entry)
685 {
686 	char			 tmp[100];
687 	size_t			 w;
688 	size_t			 sw;
689 	const char		*p;
690 	const char		*fmt;
691 	time_t			 tim;
692 	static time_t		 now;
693 	struct tm		*ltime;
694 #if defined(HAVE_LOCALTIME_R) || defined(HAVE_LOCALTIME_S)
695 	struct tm		tmbuf;
696 #endif
697 
698 	/*
699 	 * We avoid collecting the entire list in memory at once by
700 	 * listing things as we see them.  However, that also means we can't
701 	 * just pre-compute the field widths.  Instead, we start with guesses
702 	 * and just widen them as necessary.  These numbers are completely
703 	 * arbitrary.
704 	 */
705 	if (!bsdtar->u_width) {
706 		bsdtar->u_width = 6;
707 		bsdtar->gs_width = 13;
708 	}
709 	if (!now)
710 		time(&now);
711 	fprintf(out, "%s %u ",
712 	    archive_entry_strmode(entry),
713 	    archive_entry_nlink(entry));
714 
715 	/* Use uname if it's present, else uid. */
716 	p = archive_entry_uname(entry);
717 	if ((p == NULL) || (*p == '\0')) {
718 		snprintf(tmp, sizeof(tmp), "%lu ",
719 		    (unsigned long)archive_entry_uid(entry));
720 		p = tmp;
721 	}
722 	w = strlen(p);
723 	if (w > bsdtar->u_width)
724 		bsdtar->u_width = w;
725 	fprintf(out, "%-*s ", (int)bsdtar->u_width, p);
726 
727 	/* Use gname if it's present, else gid. */
728 	p = archive_entry_gname(entry);
729 	if (p != NULL && p[0] != '\0') {
730 		fprintf(out, "%s", p);
731 		w = strlen(p);
732 	} else {
733 		snprintf(tmp, sizeof(tmp), "%lu",
734 		    (unsigned long)archive_entry_gid(entry));
735 		w = strlen(tmp);
736 		fprintf(out, "%s", tmp);
737 	}
738 
739 	/*
740 	 * Print device number or file size, right-aligned so as to make
741 	 * total width of group and devnum/filesize fields be gs_width.
742 	 * If gs_width is too small, grow it.
743 	 */
744 	if (archive_entry_filetype(entry) == AE_IFCHR
745 	    || archive_entry_filetype(entry) == AE_IFBLK) {
746 		snprintf(tmp, sizeof(tmp), "%lu,%lu",
747 		    (unsigned long)archive_entry_rdevmajor(entry),
748 		    (unsigned long)archive_entry_rdevminor(entry));
749 	} else {
750 		strcpy(tmp, tar_i64toa(archive_entry_size(entry)));
751 	}
752 	if (w + strlen(tmp) >= bsdtar->gs_width)
753 		bsdtar->gs_width = w+strlen(tmp)+1;
754 	fprintf(out, "%*s", (int)(bsdtar->gs_width - w), tmp);
755 
756 	/* Format the time using 'ls -l' conventions. */
757 	tim = archive_entry_mtime(entry);
758 #define	HALF_YEAR (time_t)365 * 86400 / 2
759 #if defined(_WIN32) && !defined(__CYGWIN__)
760 #define	DAY_FMT  "%d"  /* Windows' strftime function does not support %e format. */
761 #else
762 #define	DAY_FMT  "%e"  /* Day number without leading zeros */
763 #endif
764 	if (tim < now - HALF_YEAR || tim > now + HALF_YEAR)
765 		fmt = bsdtar->day_first ? DAY_FMT " %b  %Y" : "%b " DAY_FMT "  %Y";
766 	else
767 		fmt = bsdtar->day_first ? DAY_FMT " %b %H:%M" : "%b " DAY_FMT " %H:%M";
768 #if defined(HAVE_LOCALTIME_S)
769 	ltime = localtime_s(&tmbuf, &tim) ? NULL : &tmbuf;
770 #elif defined(HAVE_LOCALTIME_R)
771 	ltime = localtime_r(&tim, &tmbuf);
772 #else
773 	ltime = localtime(&tim);
774 #endif
775 	if (ltime)
776 		sw = strftime(tmp, sizeof(tmp), fmt, ltime);
777 	if (!ltime || !sw)
778 		sprintf(tmp, "-- -- ----");
779 	fprintf(out, " %s ", tmp);
780 	safe_fprintf(out, "%s", archive_entry_pathname(entry));
781 
782 	/* Extra information for links. */
783 	if (archive_entry_hardlink(entry)) /* Hard link */
784 		safe_fprintf(out, " link to %s",
785 		    archive_entry_hardlink(entry));
786 	else if (archive_entry_symlink(entry)) /* Symbolic link */
787 		safe_fprintf(out, " -> %s", archive_entry_symlink(entry));
788 }
789