2 * Copyright (c) 2010 Nokia Corporation and/or its subsidiary(-ies).
3 * Author: Jonas Gastal <jgastal@profusion.mobi>
4 * Copyright (c) 2011 Michihiro NAKAJIMA
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 #include "archive_platform.h"
30 __FBSDID("$FreeBSD: head/lib/libarchive/archive_write_set_format_gnu_tar.c 191579 2009-04-27 18:35:03Z gastal $");
45 #include "archive_entry.h"
46 #include "archive_entry_locale.h"
47 #include "archive_private.h"
48 #include "archive_write_private.h"
51 uint64_t entry_bytes_remaining;
52 uint64_t entry_padding;
53 const char * linkname;
54 size_t linkname_length;
55 const char * pathname;
56 size_t pathname_length;
61 struct archive_string_conv *opt_sconv;
62 struct archive_string_conv *sconv_default;
63 int init_default_conversion;
67 * Define structure of GNU tar header.
69 #define GNUTAR_name_offset 0
70 #define GNUTAR_name_size 100
71 #define GNUTAR_mode_offset 100
72 #define GNUTAR_mode_size 7
73 #define GNUTAR_mode_max_size 8
74 #define GNUTAR_uid_offset 108
75 #define GNUTAR_uid_size 7
76 #define GNUTAR_uid_max_size 8
77 #define GNUTAR_gid_offset 116
78 #define GNUTAR_gid_size 7
79 #define GNUTAR_gid_max_size 8
80 #define GNUTAR_size_offset 124
81 #define GNUTAR_size_size 11
82 #define GNUTAR_size_max_size 12
83 #define GNUTAR_mtime_offset 136
84 #define GNUTAR_mtime_size 11
85 #define GNUTAR_mtime_max_size 11
86 #define GNUTAR_checksum_offset 148
87 #define GNUTAR_checksum_size 8
88 #define GNUTAR_typeflag_offset 156
89 #define GNUTAR_typeflag_size 1
90 #define GNUTAR_linkname_offset 157
91 #define GNUTAR_linkname_size 100
92 #define GNUTAR_magic_offset 257
93 #define GNUTAR_magic_size 6
94 #define GNUTAR_version_offset 263
95 #define GNUTAR_version_size 2
96 #define GNUTAR_uname_offset 265
97 #define GNUTAR_uname_size 32
98 #define GNUTAR_gname_offset 297
99 #define GNUTAR_gname_size 32
100 #define GNUTAR_rdevmajor_offset 329
101 #define GNUTAR_rdevmajor_size 6
102 #define GNUTAR_rdevmajor_max_size 8
103 #define GNUTAR_rdevminor_offset 337
104 #define GNUTAR_rdevminor_size 6
105 #define GNUTAR_rdevminor_max_size 8
108 * A filled-in copy of the header for initialization.
110 static const char template_header[] = {
111 /* name: 100 bytes */
112 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
113 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
114 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
116 /* Mode, null termination: 8 bytes */
117 '0','0','0','0','0','0', '0','\0',
118 /* uid, null termination: 8 bytes */
119 '0','0','0','0','0','0', '0','\0',
120 /* gid, null termination: 8 bytes */
121 '0','0','0','0','0','0', '0','\0',
122 /* size, space termation: 12 bytes */
123 '0','0','0','0','0','0','0','0','0','0','0', '\0',
124 /* mtime, space termation: 12 bytes */
125 '0','0','0','0','0','0','0','0','0','0','0', '\0',
126 /* Initial checksum value: 8 spaces */
127 ' ',' ',' ',' ',' ',' ',' ',' ',
128 /* Typeflag: 1 byte */
129 '0', /* '0' = regular file */
130 /* Linkname: 100 bytes */
131 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
132 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
133 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
136 'u','s','t','a','r',' ', ' ','\0',
137 /* Uname: 32 bytes */
138 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
139 /* Gname: 32 bytes */
140 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
141 /* rdevmajor + null padding: 8 bytes */
142 '\0','\0','\0','\0','\0','\0', '\0','\0',
143 /* rdevminor + null padding: 8 bytes */
144 '\0','\0','\0','\0','\0','\0', '\0','\0',
145 /* Padding: 167 bytes */
146 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
147 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
148 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
149 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
150 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
154 static int archive_write_gnutar_options(struct archive_write *,
155 const char *, const char *);
156 static int archive_format_gnutar_header(struct archive_write *, char h[512],
157 struct archive_entry *, int tartype);
158 static int archive_write_gnutar_header(struct archive_write *,
159 struct archive_entry *entry);
160 static ssize_t archive_write_gnutar_data(struct archive_write *a, const void *buff,
162 static int archive_write_gnutar_free(struct archive_write *);
163 static int archive_write_gnutar_close(struct archive_write *);
164 static int archive_write_gnutar_finish_entry(struct archive_write *);
165 static int format_256(int64_t, char *, int);
166 static int format_number(int64_t, char *, int size, int maxsize);
167 static int format_octal(int64_t, char *, int);
170 * Set output format to 'GNU tar' format.
173 archive_write_set_format_gnutar(struct archive *_a)
175 struct archive_write *a = (struct archive_write *)_a;
176 struct gnutar *gnutar;
178 gnutar = (struct gnutar *)calloc(1, sizeof(*gnutar));
179 if (gnutar == NULL) {
180 archive_set_error(&a->archive, ENOMEM, "Can't allocate gnutar data");
181 return (ARCHIVE_FATAL);
183 a->format_data = gnutar;
184 a->format_name = "gnutar";
185 a->format_options = archive_write_gnutar_options;
186 a->format_write_header = archive_write_gnutar_header;
187 a->format_write_data = archive_write_gnutar_data;
188 a->format_close = archive_write_gnutar_close;
189 a->format_free = archive_write_gnutar_free;
190 a->format_finish_entry = archive_write_gnutar_finish_entry;
191 a->archive.archive_format = ARCHIVE_FORMAT_TAR_GNUTAR;
192 a->archive.archive_format_name = "GNU tar";
197 archive_write_gnutar_options(struct archive_write *a, const char *key,
200 struct gnutar *gnutar = (struct gnutar *)a->format_data;
201 int ret = ARCHIVE_FAILED;
203 if (strcmp(key, "hdrcharset") == 0) {
204 if (val == NULL || val[0] == 0)
205 archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
206 "%s: hdrcharset option needs a character-set name",
209 gnutar->opt_sconv = archive_string_conversion_to_charset(
210 &a->archive, val, 0);
211 if (gnutar->opt_sconv != NULL)
217 archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
218 "%s: unknown keyword ``%s''", a->format_name, key);
224 archive_write_gnutar_close(struct archive_write *a)
226 return (__archive_write_nulls(a, 512*2));
230 archive_write_gnutar_free(struct archive_write *a)
232 struct gnutar *gnutar;
234 gnutar = (struct gnutar *)a->format_data;
236 a->format_data = NULL;
241 archive_write_gnutar_finish_entry(struct archive_write *a)
243 struct gnutar *gnutar;
246 gnutar = (struct gnutar *)a->format_data;
247 ret = __archive_write_nulls(a,
248 gnutar->entry_bytes_remaining + gnutar->entry_padding);
249 gnutar->entry_bytes_remaining = gnutar->entry_padding = 0;
254 archive_write_gnutar_data(struct archive_write *a, const void *buff, size_t s)
256 struct gnutar *gnutar;
259 gnutar = (struct gnutar *)a->format_data;
260 if (s > gnutar->entry_bytes_remaining)
261 s = gnutar->entry_bytes_remaining;
262 ret = __archive_write_output(a, buff, s);
263 gnutar->entry_bytes_remaining -= s;
264 if (ret != ARCHIVE_OK)
270 archive_write_gnutar_header(struct archive_write *a,
271 struct archive_entry *entry)
274 int r, ret, ret2 = ARCHIVE_OK;
276 struct gnutar *gnutar;
277 struct archive_string_conv *sconv;
279 gnutar = (struct gnutar *)a->format_data;
281 /* Setup default string conversion. */
282 if (gnutar->opt_sconv == NULL) {
283 if (!gnutar->init_default_conversion) {
284 gnutar->sconv_default =
285 archive_string_default_conversion_for_write(
287 gnutar->init_default_conversion = 1;
289 sconv = gnutar->sconv_default;
291 sconv = gnutar->opt_sconv;
293 /* Only regular files (not hardlinks) have data. */
294 if (archive_entry_hardlink(entry) != NULL ||
295 archive_entry_symlink(entry) != NULL ||
296 !(archive_entry_filetype(entry) == AE_IFREG))
297 archive_entry_set_size(entry, 0);
299 if (AE_IFDIR == archive_entry_filetype(entry)) {
303 * Ensure a trailing '/'. Modify the entry so
304 * the client sees the change.
306 p = archive_entry_pathname(entry);
307 if (p[strlen(p) - 1] != '/') {
308 t = (char *)malloc(strlen(p) + 2);
310 archive_set_error(&a->archive, ENOMEM,
311 "Can't allocate gnutar data");
312 return(ARCHIVE_FATAL);
316 archive_entry_copy_pathname(entry, t);
321 r = archive_entry_pathname_l(entry, &(gnutar->pathname),
322 &(gnutar->pathname_length), sconv);
324 if (errno == ENOMEM) {
325 archive_set_error(&a->archive, ENOMEM,
326 "Can't allocate memory for Pathame");
327 return (ARCHIVE_FATAL);
329 archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
330 "Can't translate pathname '%s' to %s",
331 archive_entry_pathname(entry),
332 archive_string_conversion_charset_name(sconv));
335 r = archive_entry_uname_l(entry, &(gnutar->uname),
336 &(gnutar->uname_length), sconv);
338 if (errno == ENOMEM) {
339 archive_set_error(&a->archive, ENOMEM,
340 "Can't allocate memory for Uname");
341 return (ARCHIVE_FATAL);
343 archive_set_error(&a->archive,
344 ARCHIVE_ERRNO_FILE_FORMAT,
345 "Can't translate uname '%s' to %s",
346 archive_entry_uname(entry),
347 archive_string_conversion_charset_name(sconv));
350 r = archive_entry_gname_l(entry, &(gnutar->gname),
351 &(gnutar->gname_length), sconv);
353 if (errno == ENOMEM) {
354 archive_set_error(&a->archive, ENOMEM,
355 "Can't allocate memory for Gname");
356 return (ARCHIVE_FATAL);
358 archive_set_error(&a->archive,
359 ARCHIVE_ERRNO_FILE_FORMAT,
360 "Can't translate gname '%s' to %s",
361 archive_entry_gname(entry),
362 archive_string_conversion_charset_name(sconv));
366 /* If linkname is longer than 100 chars we need to add a 'K' header. */
367 r = archive_entry_hardlink_l(entry, &(gnutar->linkname),
368 &(gnutar->linkname_length), sconv);
370 if (errno == ENOMEM) {
371 archive_set_error(&a->archive, ENOMEM,
372 "Can't allocate memory for Linkname");
373 return (ARCHIVE_FATAL);
375 archive_set_error(&a->archive,
376 ARCHIVE_ERRNO_FILE_FORMAT,
377 "Can't translate linkname '%s' to %s",
378 archive_entry_hardlink(entry),
379 archive_string_conversion_charset_name(sconv));
382 if (gnutar->linkname_length == 0) {
383 r = archive_entry_symlink_l(entry, &(gnutar->linkname),
384 &(gnutar->linkname_length), sconv);
386 if (errno == ENOMEM) {
387 archive_set_error(&a->archive, ENOMEM,
388 "Can't allocate memory for Linkname");
389 return (ARCHIVE_FATAL);
391 archive_set_error(&a->archive,
392 ARCHIVE_ERRNO_FILE_FORMAT,
393 "Can't translate linkname '%s' to %s",
394 archive_entry_hardlink(entry),
395 archive_string_conversion_charset_name(sconv));
399 if (gnutar->linkname_length > GNUTAR_linkname_size) {
400 size_t todo = gnutar->linkname_length;
401 struct archive_entry *temp = archive_entry_new2(&a->archive);
403 /* Uname/gname here don't really matter since noone reads them;
404 * these are the values that GNU tar happens to use on FreeBSD. */
405 archive_entry_set_uname(temp, "root");
406 archive_entry_set_gname(temp, "wheel");
408 archive_entry_set_pathname(temp, "././@LongLink");
409 archive_entry_set_size(temp, gnutar->linkname_length + 1);
410 ret = archive_format_gnutar_header(a, buff, temp, 'K');
411 if (ret < ARCHIVE_WARN)
413 ret = __archive_write_output(a, buff, 512);
414 if(ret < ARCHIVE_WARN)
416 archive_entry_free(temp);
417 /* Write as many 512 bytes blocks as needed to write full name. */
418 ret = __archive_write_output(a, gnutar->linkname, todo);
419 if(ret < ARCHIVE_WARN)
421 ret = __archive_write_nulls(a, 0x1ff & (-(ssize_t)todo));
422 if (ret < ARCHIVE_WARN)
426 /* If pathname is longer than 100 chars we need to add an 'L' header. */
427 if (gnutar->pathname_length > GNUTAR_name_size) {
428 const char *pathname = gnutar->pathname;
429 size_t todo = gnutar->pathname_length;
430 struct archive_entry *temp = archive_entry_new2(&a->archive);
432 /* Uname/gname here don't really matter since noone reads them;
433 * these are the values that GNU tar happens to use on FreeBSD. */
434 archive_entry_set_uname(temp, "root");
435 archive_entry_set_gname(temp, "wheel");
437 archive_entry_set_pathname(temp, "././@LongLink");
438 archive_entry_set_size(temp, gnutar->pathname_length + 1);
439 ret = archive_format_gnutar_header(a, buff, temp, 'L');
440 if (ret < ARCHIVE_WARN)
442 ret = __archive_write_output(a, buff, 512);
443 if(ret < ARCHIVE_WARN)
445 archive_entry_free(temp);
446 /* Write as many 512 bytes blocks as needed to write full name. */
447 ret = __archive_write_output(a, pathname, todo);
448 if(ret < ARCHIVE_WARN)
450 ret = __archive_write_nulls(a, 0x1ff & (-(ssize_t)todo));
451 if (ret < ARCHIVE_WARN)
455 if (archive_entry_hardlink(entry) != NULL) {
458 switch (archive_entry_filetype(entry)) {
459 case AE_IFREG: tartype = '0' ; break;
460 case AE_IFLNK: tartype = '2' ; break;
461 case AE_IFCHR: tartype = '3' ; break;
462 case AE_IFBLK: tartype = '4' ; break;
463 case AE_IFDIR: tartype = '5' ; break;
464 case AE_IFIFO: tartype = '6' ; break;
466 archive_set_error(&a->archive,
467 ARCHIVE_ERRNO_FILE_FORMAT,
468 "tar format cannot archive socket");
469 return (ARCHIVE_FAILED);
471 archive_set_error(&a->archive,
472 ARCHIVE_ERRNO_FILE_FORMAT,
473 "tar format cannot archive this (mode=0%lo)",
474 (unsigned long)archive_entry_mode(entry));
475 return (ARCHIVE_FAILED);
478 ret = archive_format_gnutar_header(a, buff, entry, tartype);
479 if (ret < ARCHIVE_WARN)
483 ret2 = __archive_write_output(a, buff, 512);
484 if (ret2 < ARCHIVE_WARN)
489 gnutar->entry_bytes_remaining = archive_entry_size(entry);
490 gnutar->entry_padding = 0x1ff & (-(int64_t)gnutar->entry_bytes_remaining);
495 archive_format_gnutar_header(struct archive_write *a, char h[512],
496 struct archive_entry *entry, int tartype)
498 unsigned int checksum;
502 struct gnutar *gnutar;
504 gnutar = (struct gnutar *)a->format_data;
509 * The "template header" already includes the signature,
510 * various end-of-field markers, and other required elements.
512 memcpy(h, &template_header, 512);
515 * Because the block is already null-filled, and strings
516 * are allowed to exactly fill their destination (without null),
517 * I use memcpy(dest, src, strlen()) here a lot to copy strings.
520 if (tartype == 'K' || tartype == 'L') {
521 p = archive_entry_pathname(entry);
522 copy_length = strlen(p);
524 p = gnutar->pathname;
525 copy_length = gnutar->pathname_length;
527 if (copy_length > GNUTAR_name_size)
528 copy_length = GNUTAR_name_size;
529 memcpy(h + GNUTAR_name_offset, p, copy_length);
531 if ((copy_length = gnutar->linkname_length) > 0) {
532 if (copy_length > GNUTAR_linkname_size)
533 copy_length = GNUTAR_linkname_size;
534 memcpy(h + GNUTAR_linkname_offset, gnutar->linkname,
538 /* TODO: How does GNU tar handle unames longer than GNUTAR_uname_size? */
539 if (tartype == 'K' || tartype == 'L') {
540 p = archive_entry_uname(entry);
541 copy_length = strlen(p);
544 copy_length = gnutar->uname_length;
546 if (copy_length > 0) {
547 if (copy_length > GNUTAR_uname_size)
548 copy_length = GNUTAR_uname_size;
549 memcpy(h + GNUTAR_uname_offset, p, copy_length);
552 /* TODO: How does GNU tar handle gnames longer than GNUTAR_gname_size? */
553 if (tartype == 'K' || tartype == 'L') {
554 p = archive_entry_gname(entry);
555 copy_length = strlen(p);
558 copy_length = gnutar->gname_length;
560 if (copy_length > 0) {
561 if (strlen(p) > GNUTAR_gname_size)
562 copy_length = GNUTAR_gname_size;
563 memcpy(h + GNUTAR_gname_offset, p, copy_length);
566 /* By truncating the mode here, we ensure it always fits. */
567 format_octal(archive_entry_mode(entry) & 07777,
568 h + GNUTAR_mode_offset, GNUTAR_mode_size);
570 /* TODO: How does GNU tar handle large UIDs? */
571 if (format_octal(archive_entry_uid(entry),
572 h + GNUTAR_uid_offset, GNUTAR_uid_size)) {
573 archive_set_error(&a->archive, ERANGE,
574 "Numeric user ID %jd too large",
575 (intmax_t)archive_entry_uid(entry));
576 ret = ARCHIVE_FAILED;
579 /* TODO: How does GNU tar handle large GIDs? */
580 if (format_octal(archive_entry_gid(entry),
581 h + GNUTAR_gid_offset, GNUTAR_gid_size)) {
582 archive_set_error(&a->archive, ERANGE,
583 "Numeric group ID %jd too large",
584 (intmax_t)archive_entry_gid(entry));
585 ret = ARCHIVE_FAILED;
588 /* GNU tar supports base-256 here, so should never overflow. */
589 if (format_number(archive_entry_size(entry), h + GNUTAR_size_offset,
590 GNUTAR_size_size, GNUTAR_size_max_size)) {
591 archive_set_error(&a->archive, ERANGE,
592 "File size out of range");
593 ret = ARCHIVE_FAILED;
596 /* Shouldn't overflow before 2106, since mtime field is 33 bits. */
597 format_octal(archive_entry_mtime(entry),
598 h + GNUTAR_mtime_offset, GNUTAR_mtime_size);
600 if (archive_entry_filetype(entry) == AE_IFBLK
601 || archive_entry_filetype(entry) == AE_IFCHR) {
602 if (format_octal(archive_entry_rdevmajor(entry),
603 h + GNUTAR_rdevmajor_offset,
604 GNUTAR_rdevmajor_size)) {
605 archive_set_error(&a->archive, ERANGE,
606 "Major device number too large");
607 ret = ARCHIVE_FAILED;
610 if (format_octal(archive_entry_rdevminor(entry),
611 h + GNUTAR_rdevminor_offset,
612 GNUTAR_rdevminor_size)) {
613 archive_set_error(&a->archive, ERANGE,
614 "Minor device number too large");
615 ret = ARCHIVE_FAILED;
619 h[GNUTAR_typeflag_offset] = tartype;
622 for (i = 0; i < 512; i++)
623 checksum += 255 & (unsigned int)h[i];
624 h[GNUTAR_checksum_offset + 6] = '\0'; /* Can't be pre-set in the template. */
625 /* h[GNUTAR_checksum_offset + 7] = ' '; */ /* This is pre-set in the template. */
626 format_octal(checksum, h + GNUTAR_checksum_offset, 6);
631 * Format a number into a field, falling back to base-256 if necessary.
634 format_number(int64_t v, char *p, int s, int maxsize)
636 int64_t limit = ((int64_t)1 << (s*3));
639 return (format_octal(v, p, s));
640 return (format_256(v, p, maxsize));
644 * Format a number into the specified field using base-256.
647 format_256(int64_t v, char *p, int s)
651 *--p = (char)(v & 0xff);
654 *p |= 0x80; /* Set the base-256 marker bit. */
659 * Format a number into the specified field using octal.
662 format_octal(int64_t v, char *p, int s)
666 /* Octal values can't be negative, so use 0. */
670 p += s; /* Start at the end and work backwards. */
672 *--p = (char)('0' + (v & 7));
679 /* If it overflowed, fill field with max value. */