1 /*-
2  * Copyright (c) 2003-2007 Tim Kientzle
3  * Copyright (c) 2011-2012 Michihiro NAKAJIMA
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
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 "archive_platform.h"
28 __FBSDID("$FreeBSD: head/lib/libarchive/archive_write_set_format_cpio.c 201170 2009-12-29 06:34:23Z kientzle $");
29 
30 #ifdef HAVE_ERRNO_H
31 #include <errno.h>
32 #endif
33 #include <stdio.h>
34 #ifdef HAVE_STDLIB_H
35 #include <stdlib.h>
36 #endif
37 #ifdef HAVE_STRING_H
38 #include <string.h>
39 #endif
40 
41 #include "archive.h"
42 #include "archive_entry.h"
43 #include "archive_entry_locale.h"
44 #include "archive_private.h"
45 #include "archive_write_private.h"
46 #include "archive_write_set_format_private.h"
47 
48 static ssize_t	archive_write_binary_data(struct archive_write *,
49 		    const void *buff, size_t s);
50 static int	archive_write_binary_close(struct archive_write *);
51 static int	archive_write_binary_free(struct archive_write *);
52 static int	archive_write_binary_finish_entry(struct archive_write *);
53 static int	archive_write_binary_header(struct archive_write *,
54 		    struct archive_entry *);
55 static int	archive_write_binary_options(struct archive_write *,
56 		    const char *, const char *);
57 static int	write_header(struct archive_write *, struct archive_entry *);
58 
59 struct cpio {
60 	uint64_t	  entry_bytes_remaining;
61 
62 	int64_t		  ino_next;
63 
64 	struct		 { int64_t old; int new;} *ino_list;
65 	size_t		  ino_list_size;
66 	size_t		  ino_list_next;
67 
68 	struct archive_string_conv *opt_sconv;
69 	struct archive_string_conv *sconv_default;
70 	int		  init_default_conversion;
71 };
72 
73 /* This struct needs to be packed to get the header right */
74 
75 #if defined(__GNUC__)
76 #define PACKED(x) x __attribute__((packed))
77 #elif defined(_MSC_VER)
78 #define PACKED(x) __pragma(pack(push, 1)) x __pragma(pack(pop))
79 #else
80 #define PACKED(x) x
81 #endif
82 
83 #define HSIZE 26
84 
85 PACKED(struct cpio_binary_header {
86 	uint16_t	h_magic;
87 	uint16_t	h_dev;
88 	uint16_t	h_ino;
89 	uint16_t	h_mode;
90 	uint16_t	h_uid;
91 	uint16_t	h_gid;
92 	uint16_t	h_nlink;
93 	uint16_t	h_majmin;
94 	uint32_t	h_mtime;
95 	uint16_t	h_namesize;
96 	uint32_t	h_filesize;
97 });
98 
99 /* Back in the day, the 7th Edition cpio.c had this, to
100  * adapt to, as the comment said, "VAX, Interdata, ...":
101  *
102  * union { long l; short s[2]; char c[4]; } U;
103  * #define MKSHORT(v,lv) {U.l=1L;if(U.c[0]) U.l=lv,v[0]=U.s[1],v[1]=U.s[0]; else U.l=lv,v[0]=U.s[0],v[1]=U.s[1];}
104  * long mklong(v)
105  * short v[];
106  * {
107  *         U.l = 1;
108  *         if(U.c[0])
109  *                 U.s[0] = v[1], U.s[1] = v[0];
110  *         else
111  *                 U.s[0] = v[0], U.s[1] = v[1];
112  *         return U.l;
113  * }
114  *
115  * Of course, that assumes that all machines have little-endian shorts,
116  * and just adapts the others to the special endianness of the PDP-11.
117  *
118  * Now, we could do this:
119  *
120  * union { uint32_t l; uint16_t s[2]; uint8_t c[4]; } U;
121  * #define PUTI16(v,sv) {U.s[0]=1;if(U.c[0]) v=sv; else U.s[0]=sv,U.c[2]=U.c[1],U.c[3]=U.c[0],v=U.s[1];}
122  * #define PUTI32(v,lv) {char_t Ut;U.l=1;if(U.c[0]) U.l=lv,v[0]=U.s[1],v[1]=U.s[0]; else U.l=lv,Ut=U.c[0],U.c[0]=U.c[1],U.c[1]=Ut,Ut=U.c[2],U.c[2]=U.c[3],U.c[3]=Ut,v[0]=U.s[0],v[1]=U.s[1];}
123  *
124  * ...but it feels a little better to do it like this:
125  */
126 
127 static uint16_t la_swap16(uint16_t in) {
128 	union {
129 		uint16_t s[2];
130 		uint8_t c[4];
131 	} U;
132 	U.s[0] = 1;
133 	if (U.c[0])
134 		return in;
135 	else {
136 		U.s[0] = in;
137 		U.c[2] = U.c[1];
138 		U.c[3] = U.c[0];
139 		return U.s[1];
140 	}
141 	/* NOTREACHED */
142 }
143 
144 static uint32_t la_swap32(uint32_t in) {
145 	union {
146 		uint32_t l;
147 		uint16_t s[2];
148 		uint8_t c[4];
149 	} U;
150 	U.l = 1;
151 	if (U.c[0]) {		/* Little-endian */
152 		uint16_t t;
153 		U.l = in;
154 		t = U.s[0];
155 		U.s[0] = U.s[1];
156 		U.s[1] = t;
157 	} else if (U.c[3]) {	/* Big-endian */
158 		U.l = in;
159 		U.s[0] = la_swap16(U.s[0]);
160 		U.s[1] = la_swap16(U.s[1]);
161 	} else {		/* PDP-endian */
162 		U.l = in;
163 	}
164 	return U.l;
165 }
166 
167 /*
168  * Set output format to the selected binary variant
169  */
170 static int
171 archive_write_set_format_cpio_binary(struct archive *_a, int format)
172 {
173 	struct archive_write *a = (struct archive_write *)_a;
174 	struct cpio *cpio;
175 
176 	if (sizeof(struct cpio_binary_header) != HSIZE) {
177 		archive_set_error(&a->archive, EINVAL,
178 				  "Binary cpio format not supported on this platform");
179 		return (ARCHIVE_FATAL);
180 	}
181 
182 	archive_check_magic(_a, ARCHIVE_WRITE_MAGIC,
183 	    ARCHIVE_STATE_NEW, "archive_write_set_format_cpio_binary");
184 
185 	/* If someone else was already registered, unregister them. */
186 	if (a->format_free != NULL)
187 		(a->format_free)(a);
188 
189 	cpio = (struct cpio *)calloc(1, sizeof(*cpio));
190 	if (cpio == NULL) {
191 		archive_set_error(&a->archive, ENOMEM, "Can't allocate cpio data");
192 		return (ARCHIVE_FATAL);
193 	}
194 	a->format_data = cpio;
195 	a->format_name = "cpio";
196 	a->format_options = archive_write_binary_options;
197 	a->format_write_header = archive_write_binary_header;
198 	a->format_write_data = archive_write_binary_data;
199 	a->format_finish_entry = archive_write_binary_finish_entry;
200 	a->format_close = archive_write_binary_close;
201 	a->format_free = archive_write_binary_free;
202 	a->archive.archive_format = format;
203 	switch (format) {
204 	case ARCHIVE_FORMAT_CPIO_PWB:
205 		a->archive.archive_format_name = "PWB cpio";
206 		break;
207 	case ARCHIVE_FORMAT_CPIO_BIN_LE:
208 		a->archive.archive_format_name = "7th Edition cpio";
209 		break;
210 	default:
211 		archive_set_error(&a->archive, EINVAL, "binary format must be 'pwb' or 'bin'");
212 		return (ARCHIVE_FATAL);
213 	}
214 	return (ARCHIVE_OK);
215 }
216 
217 /*
218  * Set output format to PWB (6th Edition) binary format
219  */
220 int
221 archive_write_set_format_cpio_pwb(struct archive *_a)
222 {
223 	return archive_write_set_format_cpio_binary(_a, ARCHIVE_FORMAT_CPIO_PWB);
224 }
225 
226 /*
227  * Set output format to 7th Edition binary format
228  */
229 int
230 archive_write_set_format_cpio_bin(struct archive *_a)
231 {
232 	return archive_write_set_format_cpio_binary(_a, ARCHIVE_FORMAT_CPIO_BIN_LE);
233 }
234 
235 static int
236 archive_write_binary_options(struct archive_write *a, const char *key,
237     const char *val)
238 {
239 	struct cpio *cpio = (struct cpio *)a->format_data;
240 	int ret = ARCHIVE_FAILED;
241 
242 	if (strcmp(key, "hdrcharset")  == 0) {
243 		if (val == NULL || val[0] == 0)
244 			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
245 			    "%s: hdrcharset option needs a character-set name",
246 			    a->format_name);
247 		else {
248 			cpio->opt_sconv = archive_string_conversion_to_charset(
249 			    &a->archive, val, 0);
250 			if (cpio->opt_sconv != NULL)
251 				ret = ARCHIVE_OK;
252 			else
253 				ret = ARCHIVE_FATAL;
254 		}
255 		return (ret);
256 	}
257 
258 	/* Note: The "warn" return is just to inform the options
259 	 * supervisor that we didn't handle it.  It will generate
260 	 * a suitable error if no one used this option. */
261 	return (ARCHIVE_WARN);
262 }
263 
264 /*
265  * Ino values are as long as 64 bits on some systems; cpio format
266  * only allows 16 bits and relies on the ino values to identify hardlinked
267  * files.  So, we can't merely "hash" the ino numbers since collisions
268  * would corrupt the archive.  Instead, we generate synthetic ino values
269  * to store in the archive and maintain a map of original ino values to
270  * synthetic ones so we can preserve hardlink information.
271  *
272  * TODO: Make this more efficient.  It's not as bad as it looks (most
273  * files don't have any hardlinks and we don't do any work here for those),
274  * but it wouldn't be hard to do better.
275  *
276  * TODO: Work with dev/ino pairs here instead of just ino values.
277  */
278 static int
279 synthesize_ino_value(struct cpio *cpio, struct archive_entry *entry)
280 {
281 	int64_t ino = archive_entry_ino64(entry);
282 	int ino_new;
283 	size_t i;
284 
285 	/*
286 	 * If no index number was given, don't assign one.  In
287 	 * particular, this handles the end-of-archive marker
288 	 * correctly by giving it a zero index value.  (This is also
289 	 * why we start our synthetic index numbers with one below.)
290 	 */
291 	if (ino == 0)
292 		return (0);
293 
294 	/* Don't store a mapping if we don't need to. */
295 	if (archive_entry_nlink(entry) < 2) {
296 		return (int)(++cpio->ino_next);
297 	}
298 
299 	/* Look up old ino; if we have it, this is a hardlink
300 	 * and we reuse the same value. */
301 	for (i = 0; i < cpio->ino_list_next; ++i) {
302 		if (cpio->ino_list[i].old == ino)
303 			return (cpio->ino_list[i].new);
304 	}
305 
306 	/* Assign a new index number. */
307 	ino_new = (int)(++cpio->ino_next);
308 
309 	/* Ensure space for the new mapping. */
310 	if (cpio->ino_list_size <= cpio->ino_list_next) {
311 		size_t newsize = cpio->ino_list_size < 512
312 		    ? 512 : cpio->ino_list_size * 2;
313 		void *newlist = realloc(cpio->ino_list,
314 		    sizeof(cpio->ino_list[0]) * newsize);
315 		if (newlist == NULL)
316 			return (-1);
317 
318 		cpio->ino_list_size = newsize;
319 		cpio->ino_list = newlist;
320 	}
321 
322 	/* Record and return the new value. */
323 	cpio->ino_list[cpio->ino_list_next].old = ino;
324 	cpio->ino_list[cpio->ino_list_next].new = ino_new;
325 	++cpio->ino_list_next;
326 	return (ino_new);
327 }
328 
329 
330 static struct archive_string_conv *
331 get_sconv(struct archive_write *a)
332 {
333 	struct cpio *cpio;
334 	struct archive_string_conv *sconv;
335 
336 	cpio = (struct cpio *)a->format_data;
337 	sconv = cpio->opt_sconv;
338 	if (sconv == NULL) {
339 		if (!cpio->init_default_conversion) {
340 			cpio->sconv_default =
341 			    archive_string_default_conversion_for_write(
342 			      &(a->archive));
343 			cpio->init_default_conversion = 1;
344 		}
345 		sconv = cpio->sconv_default;
346 	}
347 	return (sconv);
348 }
349 
350 static int
351 archive_write_binary_header(struct archive_write *a, struct archive_entry *entry)
352 {
353 	const char *path;
354 	size_t len;
355 
356 	if (archive_entry_filetype(entry) == 0 && archive_entry_hardlink(entry) == NULL) {
357 		archive_set_error(&a->archive, -1, "Filetype required");
358 		return (ARCHIVE_FAILED);
359 	}
360 
361 	if (archive_entry_pathname_l(entry, &path, &len, get_sconv(a)) != 0
362 	    && errno == ENOMEM) {
363 		archive_set_error(&a->archive, ENOMEM,
364 		    "Can't allocate memory for Pathname");
365 		return (ARCHIVE_FATAL);
366 	}
367 	if (len == 0 || path == NULL || path[0] == '\0') {
368 		archive_set_error(&a->archive, -1, "Pathname required");
369 		return (ARCHIVE_FAILED);
370 	}
371 
372 	if (!archive_entry_size_is_set(entry) || archive_entry_size(entry) < 0) {
373 		archive_set_error(&a->archive, -1, "Size required");
374 		return (ARCHIVE_FAILED);
375 	}
376 	return write_header(a, entry);
377 }
378 
379 static int
380 write_header(struct archive_write *a, struct archive_entry *entry)
381 {
382 	struct cpio *cpio;
383 	const char *p, *path;
384 	int pathlength, ret, ret_final;
385 	int64_t	ino;
386 	struct cpio_binary_header h;
387 	struct archive_string_conv *sconv;
388 	struct archive_entry *entry_main;
389 	size_t len;
390 
391 	cpio = (struct cpio *)a->format_data;
392 	ret_final = ARCHIVE_OK;
393 	sconv = get_sconv(a);
394 
395 #if defined(_WIN32) && !defined(__CYGWIN__)
396 	/* Make sure the path separators in pathname, hardlink and symlink
397 	 * are all slash '/', not the Windows path separator '\'. */
398 	entry_main = __la_win_entry_in_posix_pathseparator(entry);
399 	if (entry_main == NULL) {
400 		archive_set_error(&a->archive, ENOMEM,
401 		    "Can't allocate ustar data");
402 		return(ARCHIVE_FATAL);
403 	}
404 	if (entry != entry_main)
405 		entry = entry_main;
406 	else
407 		entry_main = NULL;
408 #else
409 	entry_main = NULL;
410 #endif
411 
412 	ret = archive_entry_pathname_l(entry, &path, &len, sconv);
413 	if (ret != 0) {
414 		if (errno == ENOMEM) {
415 			archive_set_error(&a->archive, ENOMEM,
416 			    "Can't allocate memory for Pathname");
417 			ret_final = ARCHIVE_FATAL;
418 			goto exit_write_header;
419 		}
420 		archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
421 		    "Can't translate pathname '%s' to %s",
422 		    archive_entry_pathname(entry),
423 		    archive_string_conversion_charset_name(sconv));
424 		ret_final = ARCHIVE_WARN;
425 	}
426 	/* Include trailing null */
427 	pathlength = (int)len + 1;
428 
429 	h.h_magic = la_swap16(070707);
430 	h.h_dev = la_swap16(archive_entry_dev(entry));
431 
432 	ino = synthesize_ino_value(cpio, entry);
433 	if (ino < 0) {
434 		archive_set_error(&a->archive, ENOMEM,
435 		    "No memory for ino translation table");
436 		ret_final = ARCHIVE_FATAL;
437 		goto exit_write_header;
438 	} else if (ino > 077777) {
439 		archive_set_error(&a->archive, ERANGE,
440 		    "Too many files for this cpio format");
441 		ret_final = ARCHIVE_FATAL;
442 		goto exit_write_header;
443 	}
444 	h.h_ino = la_swap16((uint16_t)ino);
445 
446 	h.h_mode = archive_entry_mode(entry);
447 	if (((h.h_mode & AE_IFMT) == AE_IFSOCK) || ((h.h_mode & AE_IFMT) == AE_IFIFO)) {
448 		archive_set_error(&a->archive, EINVAL,
449 				  "sockets and fifos cannot be represented in the binary cpio formats");
450 		ret_final = ARCHIVE_FATAL;
451 		goto exit_write_header;
452 	}
453 	if (a->archive.archive_format == ARCHIVE_FORMAT_CPIO_PWB) {
454 		if ((h.h_mode & AE_IFMT) == AE_IFLNK) {
455 			archive_set_error(&a->archive, EINVAL,
456 					  "symbolic links cannot be represented in the PWB cpio format");
457 			ret_final = ARCHIVE_FATAL;
458 			goto exit_write_header;
459 		}
460 		/* we could turn off AE_IFREG here, but it does no harm, */
461 		/* and allows v7 cpio to read the entry without confusion */
462 	}
463 	h.h_mode = la_swap16(h.h_mode);
464 
465 	h.h_uid = la_swap16((uint16_t)archive_entry_uid(entry));
466 	h.h_gid = la_swap16((uint16_t)archive_entry_gid(entry));
467 	h.h_nlink = la_swap16((uint16_t)archive_entry_nlink(entry));
468 
469 	if (archive_entry_filetype(entry) == AE_IFBLK
470 	    || archive_entry_filetype(entry) == AE_IFCHR)
471 		h.h_majmin = la_swap16(archive_entry_rdev(entry));
472 	else
473 		h.h_majmin = 0;
474 
475 	h.h_mtime = la_swap32((uint32_t)archive_entry_mtime(entry));
476 	h.h_namesize = la_swap16(pathlength);
477 
478 	/* Non-regular files don't store bodies. */
479 	if (archive_entry_filetype(entry) != AE_IFREG)
480 		archive_entry_set_size(entry, 0);
481 
482 	/* Symlinks get the link written as the body of the entry. */
483 	ret = archive_entry_symlink_l(entry, &p, &len, sconv);
484 	if (ret != 0) {
485 		if (errno == ENOMEM) {
486 			archive_set_error(&a->archive, ENOMEM,
487 			    "Can't allocate memory for Linkname");
488 			ret_final = ARCHIVE_FATAL;
489 			goto exit_write_header;
490 		}
491 		archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
492 		    "Can't translate linkname '%s' to %s",
493 		    archive_entry_symlink(entry),
494 		    archive_string_conversion_charset_name(sconv));
495 		ret_final = ARCHIVE_WARN;
496 	}
497 
498 	if (len > 0 && p != NULL  &&  *p != '\0') {
499 		if (a->archive.archive_format == ARCHIVE_FORMAT_CPIO_PWB) {
500 			archive_set_error(&a->archive, EINVAL,
501 					  "symlinks are not supported by UNIX V6 or by PWB cpio");
502 			ret_final = ARCHIVE_FATAL;
503 			goto exit_write_header;
504 		}
505 		h.h_filesize = la_swap32((uint32_t)strlen(p)); /* symlink */
506 	} else {
507 		if ((a->archive.archive_format == ARCHIVE_FORMAT_CPIO_PWB) &&
508 		    (archive_entry_size(entry) > 256*256*256-1)) {
509 			archive_set_error(&a->archive, ERANGE,
510 					  "File is too large for PWB binary cpio format.");
511 			ret_final = ARCHIVE_FAILED;
512 			goto exit_write_header;
513 		} else if (archive_entry_size(entry) > INT32_MAX) {
514 			archive_set_error(&a->archive, ERANGE,
515 					  "File is too large for binary cpio format.");
516 			ret_final = ARCHIVE_FAILED;
517 			goto exit_write_header;
518 		}
519 		h.h_filesize = la_swap32((uint32_t)archive_entry_size(entry)); /* file */
520 	}
521 
522 	ret = __archive_write_output(a, &h, HSIZE);
523 	if (ret != ARCHIVE_OK) {
524 		ret_final = ARCHIVE_FATAL;
525 		goto exit_write_header;
526 	}
527 
528 	ret = __archive_write_output(a, path, pathlength);
529 	if ((ret == ARCHIVE_OK) && ((pathlength % 2) != 0))
530 		ret = __archive_write_nulls(a, 1);
531 	if (ret != ARCHIVE_OK) {
532 		ret_final = ARCHIVE_FATAL;
533 		goto exit_write_header;
534 	}
535 
536 	cpio->entry_bytes_remaining = archive_entry_size(entry);
537 	if ((cpio->entry_bytes_remaining % 2) != 0)
538 		cpio->entry_bytes_remaining++;
539 
540 	/* Write the symlink now. */
541 	if (p != NULL  &&  *p != '\0') {
542 		ret = __archive_write_output(a, p, strlen(p));
543 		if ((ret == ARCHIVE_OK) && ((strlen(p) % 2) != 0))
544 			ret = __archive_write_nulls(a, 1);
545 		if (ret != ARCHIVE_OK) {
546 			ret_final = ARCHIVE_FATAL;
547 			goto exit_write_header;
548 		}
549 	}
550 
551 exit_write_header:
552 	archive_entry_free(entry_main);
553 	return (ret_final);
554 }
555 
556 static ssize_t
557 archive_write_binary_data(struct archive_write *a, const void *buff, size_t s)
558 {
559 	struct cpio *cpio;
560 	int ret;
561 
562 	cpio = (struct cpio *)a->format_data;
563 	if (s > cpio->entry_bytes_remaining)
564 		s = (size_t)cpio->entry_bytes_remaining;
565 
566 	ret = __archive_write_output(a, buff, s);
567 	cpio->entry_bytes_remaining -= s;
568 	if (ret >= 0)
569 		return (s);
570 	else
571 		return (ret);
572 }
573 
574 static int
575 archive_write_binary_close(struct archive_write *a)
576 {
577 	int er;
578 	struct archive_entry *trailer;
579 
580 	trailer = archive_entry_new2(NULL);
581 	/* nlink = 1 here for GNU cpio compat. */
582 	archive_entry_set_nlink(trailer, 1);
583 	archive_entry_set_size(trailer, 0);
584 	archive_entry_set_pathname(trailer, "TRAILER!!!");
585 	er = write_header(a, trailer);
586 	archive_entry_free(trailer);
587 	return (er);
588 }
589 
590 static int
591 archive_write_binary_free(struct archive_write *a)
592 {
593 	struct cpio *cpio;
594 
595 	cpio = (struct cpio *)a->format_data;
596 	free(cpio->ino_list);
597 	free(cpio);
598 	a->format_data = NULL;
599 	return (ARCHIVE_OK);
600 }
601 
602 static int
603 archive_write_binary_finish_entry(struct archive_write *a)
604 {
605 	struct cpio *cpio;
606 
607 	cpio = (struct cpio *)a->format_data;
608 	return (__archive_write_nulls(a,
609 		(size_t)cpio->entry_bytes_remaining));
610 }
611