1 // SPDX-License-Identifier: LGPL-2.1+
2 /*
3 * This implementation is based on code from uClibc-0.9.30.3 but was
4 * modified and extended for use within U-Boot.
5 *
6 * Copyright (C) 2010-2013 Wolfgang Denk <wd@denx.de>
7 *
8 * Original license header:
9 *
10 * Copyright (C) 1993, 1995, 1996, 1997, 2002 Free Software Foundation, Inc.
11 * This file is part of the GNU C Library.
12 * Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1993.
13 */
14
15 #include <errno.h>
16 #include <malloc.h>
17
18 #ifdef USE_HOSTCC /* HOST build */
19 # include <string.h>
20 # include <assert.h>
21 # include <ctype.h>
22
23 # ifndef debug
24 # ifdef DEBUG
25 # define debug(fmt,args...) printf(fmt ,##args)
26 # else
27 # define debug(fmt,args...)
28 # endif
29 # endif
30 #else /* U-Boot build */
31 # include <common.h>
32 # include <linux/string.h>
33 # include <linux/ctype.h>
34 #endif
35
36 #ifndef CONFIG_ENV_MIN_ENTRIES /* minimum number of entries */
37 #define CONFIG_ENV_MIN_ENTRIES 64
38 #endif
39 #ifndef CONFIG_ENV_MAX_ENTRIES /* maximum number of entries */
40 #define CONFIG_ENV_MAX_ENTRIES 512
41 #endif
42
43 #include <env_callback.h>
44 #include <env_flags.h>
45 #include <search.h>
46 #include <slre.h>
47
48 /*
49 * [Aho,Sethi,Ullman] Compilers: Principles, Techniques and Tools, 1986
50 * [Knuth] The Art of Computer Programming, part 3 (6.4)
51 */
52
53 /*
54 * The reentrant version has no static variables to maintain the state.
55 * Instead the interface of all functions is extended to take an argument
56 * which describes the current status.
57 */
58
59 typedef struct _ENTRY {
60 int used;
61 ENTRY entry;
62 } _ENTRY;
63
64
65 static void _hdelete(const char *key, struct hsearch_data *htab, ENTRY *ep,
66 int idx);
67
68 /*
69 * hcreate()
70 */
71
72 /*
73 * For the used double hash method the table size has to be a prime. To
74 * correct the user given table size we need a prime test. This trivial
75 * algorithm is adequate because
76 * a) the code is (most probably) called a few times per program run and
77 * b) the number is small because the table must fit in the core
78 * */
isprime(unsigned int number)79 static int isprime(unsigned int number)
80 {
81 /* no even number will be passed */
82 unsigned int div = 3;
83
84 while (div * div < number && number % div != 0)
85 div += 2;
86
87 return number % div != 0;
88 }
89
90 /*
91 * Before using the hash table we must allocate memory for it.
92 * Test for an existing table are done. We allocate one element
93 * more as the found prime number says. This is done for more effective
94 * indexing as explained in the comment for the hsearch function.
95 * The contents of the table is zeroed, especially the field used
96 * becomes zero.
97 */
98
hcreate_r(size_t nel,struct hsearch_data * htab)99 int hcreate_r(size_t nel, struct hsearch_data *htab)
100 {
101 /* Test for correct arguments. */
102 if (htab == NULL) {
103 __set_errno(EINVAL);
104 return 0;
105 }
106
107 /* There is still another table active. Return with error. */
108 if (htab->table != NULL)
109 return 0;
110
111 /* Change nel to the first prime number not smaller as nel. */
112 nel |= 1; /* make odd */
113 while (!isprime(nel))
114 nel += 2;
115
116 htab->size = nel;
117 htab->filled = 0;
118
119 /* allocate memory and zero out */
120 htab->table = (_ENTRY *) calloc(htab->size + 1, sizeof(_ENTRY));
121 if (htab->table == NULL)
122 return 0;
123
124 /* everything went alright */
125 return 1;
126 }
127
128
129 /*
130 * hdestroy()
131 */
132
133 /*
134 * After using the hash table it has to be destroyed. The used memory can
135 * be freed and the local static variable can be marked as not used.
136 */
137
hdestroy_r(struct hsearch_data * htab)138 void hdestroy_r(struct hsearch_data *htab)
139 {
140 int i;
141
142 /* Test for correct arguments. */
143 if (htab == NULL) {
144 __set_errno(EINVAL);
145 return;
146 }
147
148 /* free used memory */
149 for (i = 1; i <= htab->size; ++i) {
150 if (htab->table[i].used > 0) {
151 ENTRY *ep = &htab->table[i].entry;
152
153 free((void *)ep->key);
154 free(ep->data);
155 }
156 }
157 free(htab->table);
158
159 /* the sign for an existing table is an value != NULL in htable */
160 htab->table = NULL;
161 }
162
163 /*
164 * hsearch()
165 */
166
167 /*
168 * This is the search function. It uses double hashing with open addressing.
169 * The argument item.key has to be a pointer to an zero terminated, most
170 * probably strings of chars. The function for generating a number of the
171 * strings is simple but fast. It can be replaced by a more complex function
172 * like ajw (see [Aho,Sethi,Ullman]) if the needs are shown.
173 *
174 * We use an trick to speed up the lookup. The table is created by hcreate
175 * with one more element available. This enables us to use the index zero
176 * special. This index will never be used because we store the first hash
177 * index in the field used where zero means not used. Every other value
178 * means used. The used field can be used as a first fast comparison for
179 * equality of the stored and the parameter value. This helps to prevent
180 * unnecessary expensive calls of strcmp.
181 *
182 * This implementation differs from the standard library version of
183 * this function in a number of ways:
184 *
185 * - While the standard version does not make any assumptions about
186 * the type of the stored data objects at all, this implementation
187 * works with NUL terminated strings only.
188 * - Instead of storing just pointers to the original objects, we
189 * create local copies so the caller does not need to care about the
190 * data any more.
191 * - The standard implementation does not provide a way to update an
192 * existing entry. This version will create a new entry or update an
193 * existing one when both "action == ENTER" and "item.data != NULL".
194 * - Instead of returning 1 on success, we return the index into the
195 * internal hash table, which is also guaranteed to be positive.
196 * This allows us direct access to the found hash table slot for
197 * example for functions like hdelete().
198 */
199
hmatch_r(const char * match,int last_idx,ENTRY ** retval,struct hsearch_data * htab)200 int hmatch_r(const char *match, int last_idx, ENTRY ** retval,
201 struct hsearch_data *htab)
202 {
203 unsigned int idx;
204 size_t key_len = strlen(match);
205
206 for (idx = last_idx + 1; idx < htab->size; ++idx) {
207 if (htab->table[idx].used <= 0)
208 continue;
209 if (!strncmp(match, htab->table[idx].entry.key, key_len)) {
210 *retval = &htab->table[idx].entry;
211 return idx;
212 }
213 }
214
215 __set_errno(ESRCH);
216 *retval = NULL;
217 return 0;
218 }
219
220 /*
221 * Compare an existing entry with the desired key, and overwrite if the action
222 * is ENTER. This is simply a helper function for hsearch_r().
223 */
_compare_and_overwrite_entry(ENTRY item,ACTION action,ENTRY ** retval,struct hsearch_data * htab,int flag,unsigned int hval,unsigned int idx)224 static inline int _compare_and_overwrite_entry(ENTRY item, ACTION action,
225 ENTRY **retval, struct hsearch_data *htab, int flag,
226 unsigned int hval, unsigned int idx)
227 {
228 if (htab->table[idx].used == hval
229 && strcmp(item.key, htab->table[idx].entry.key) == 0) {
230 /* Overwrite existing value? */
231 if ((action == ENTER) && (item.data != NULL)) {
232 /* check for permission */
233 if (htab->change_ok != NULL && htab->change_ok(
234 &htab->table[idx].entry, item.data,
235 env_op_overwrite, flag)) {
236 debug("change_ok() rejected setting variable "
237 "%s, skipping it!\n", item.key);
238 __set_errno(EPERM);
239 *retval = NULL;
240 return 0;
241 }
242
243 /* If there is a callback, call it */
244 if (htab->table[idx].entry.callback &&
245 htab->table[idx].entry.callback(item.key,
246 item.data, env_op_overwrite, flag)) {
247 debug("callback() rejected setting variable "
248 "%s, skipping it!\n", item.key);
249 __set_errno(EINVAL);
250 *retval = NULL;
251 return 0;
252 }
253
254 free(htab->table[idx].entry.data);
255 htab->table[idx].entry.data = strdup(item.data);
256 if (!htab->table[idx].entry.data) {
257 __set_errno(ENOMEM);
258 *retval = NULL;
259 return 0;
260 }
261 }
262 /* return found entry */
263 *retval = &htab->table[idx].entry;
264 return idx;
265 }
266 /* keep searching */
267 return -1;
268 }
269
hsearch_r(ENTRY item,ACTION action,ENTRY ** retval,struct hsearch_data * htab,int flag)270 int hsearch_r(ENTRY item, ACTION action, ENTRY ** retval,
271 struct hsearch_data *htab, int flag)
272 {
273 unsigned int hval;
274 unsigned int count;
275 unsigned int len = strlen(item.key);
276 unsigned int idx;
277 unsigned int first_deleted = 0;
278 int ret;
279
280 /* Compute an value for the given string. Perhaps use a better method. */
281 hval = len;
282 count = len;
283 while (count-- > 0) {
284 hval <<= 4;
285 hval += item.key[count];
286 }
287
288 /*
289 * First hash function:
290 * simply take the modul but prevent zero.
291 */
292 hval %= htab->size;
293 if (hval == 0)
294 ++hval;
295
296 /* The first index tried. */
297 idx = hval;
298
299 if (htab->table[idx].used) {
300 /*
301 * Further action might be required according to the
302 * action value.
303 */
304 unsigned hval2;
305
306 if (htab->table[idx].used == -1
307 && !first_deleted)
308 first_deleted = idx;
309
310 ret = _compare_and_overwrite_entry(item, action, retval, htab,
311 flag, hval, idx);
312 if (ret != -1)
313 return ret;
314
315 /*
316 * Second hash function:
317 * as suggested in [Knuth]
318 */
319 hval2 = 1 + hval % (htab->size - 2);
320
321 do {
322 /*
323 * Because SIZE is prime this guarantees to
324 * step through all available indices.
325 */
326 if (idx <= hval2)
327 idx = htab->size + idx - hval2;
328 else
329 idx -= hval2;
330
331 /*
332 * If we visited all entries leave the loop
333 * unsuccessfully.
334 */
335 if (idx == hval)
336 break;
337
338 /* If entry is found use it. */
339 ret = _compare_and_overwrite_entry(item, action, retval,
340 htab, flag, hval, idx);
341 if (ret != -1)
342 return ret;
343 }
344 while (htab->table[idx].used);
345 }
346
347 /* An empty bucket has been found. */
348 if (action == ENTER) {
349 /*
350 * If table is full and another entry should be
351 * entered return with error.
352 */
353 if (htab->filled == htab->size) {
354 __set_errno(ENOMEM);
355 *retval = NULL;
356 return 0;
357 }
358
359 /*
360 * Create new entry;
361 * create copies of item.key and item.data
362 */
363 if (first_deleted)
364 idx = first_deleted;
365
366 htab->table[idx].used = hval;
367 htab->table[idx].entry.key = strdup(item.key);
368 htab->table[idx].entry.data = strdup(item.data);
369 if (!htab->table[idx].entry.key ||
370 !htab->table[idx].entry.data) {
371 __set_errno(ENOMEM);
372 *retval = NULL;
373 return 0;
374 }
375
376 ++htab->filled;
377
378 /* This is a new entry, so look up a possible callback */
379 env_callback_init(&htab->table[idx].entry);
380 /* Also look for flags */
381 env_flags_init(&htab->table[idx].entry);
382
383 /* check for permission */
384 if (htab->change_ok != NULL && htab->change_ok(
385 &htab->table[idx].entry, item.data, env_op_create, flag)) {
386 debug("change_ok() rejected setting variable "
387 "%s, skipping it!\n", item.key);
388 _hdelete(item.key, htab, &htab->table[idx].entry, idx);
389 __set_errno(EPERM);
390 *retval = NULL;
391 return 0;
392 }
393
394 /* If there is a callback, call it */
395 if (htab->table[idx].entry.callback &&
396 htab->table[idx].entry.callback(item.key, item.data,
397 env_op_create, flag)) {
398 debug("callback() rejected setting variable "
399 "%s, skipping it!\n", item.key);
400 _hdelete(item.key, htab, &htab->table[idx].entry, idx);
401 __set_errno(EINVAL);
402 *retval = NULL;
403 return 0;
404 }
405
406 /* return new entry */
407 *retval = &htab->table[idx].entry;
408 return 1;
409 }
410
411 __set_errno(ESRCH);
412 *retval = NULL;
413 return 0;
414 }
415
416
417 /*
418 * hdelete()
419 */
420
421 /*
422 * The standard implementation of hsearch(3) does not provide any way
423 * to delete any entries from the hash table. We extend the code to
424 * do that.
425 */
426
_hdelete(const char * key,struct hsearch_data * htab,ENTRY * ep,int idx)427 static void _hdelete(const char *key, struct hsearch_data *htab, ENTRY *ep,
428 int idx)
429 {
430 /* free used ENTRY */
431 debug("hdelete: DELETING key \"%s\"\n", key);
432 free((void *)ep->key);
433 free(ep->data);
434 ep->callback = NULL;
435 ep->flags = 0;
436 htab->table[idx].used = -1;
437
438 --htab->filled;
439 }
440
hdelete_r(const char * key,struct hsearch_data * htab,int flag)441 int hdelete_r(const char *key, struct hsearch_data *htab, int flag)
442 {
443 ENTRY e, *ep;
444 int idx;
445
446 debug("hdelete: DELETE key \"%s\"\n", key);
447
448 e.key = (char *)key;
449
450 idx = hsearch_r(e, FIND, &ep, htab, 0);
451 if (idx == 0) {
452 __set_errno(ESRCH);
453 return 0; /* not found */
454 }
455
456 /* Check for permission */
457 if (htab->change_ok != NULL &&
458 htab->change_ok(ep, NULL, env_op_delete, flag)) {
459 debug("change_ok() rejected deleting variable "
460 "%s, skipping it!\n", key);
461 __set_errno(EPERM);
462 return 0;
463 }
464
465 /* If there is a callback, call it */
466 if (htab->table[idx].entry.callback &&
467 htab->table[idx].entry.callback(key, NULL, env_op_delete, flag)) {
468 debug("callback() rejected deleting variable "
469 "%s, skipping it!\n", key);
470 __set_errno(EINVAL);
471 return 0;
472 }
473
474 _hdelete(key, htab, ep, idx);
475
476 return 1;
477 }
478
479 #if !(defined(CONFIG_SPL_BUILD) && !defined(CONFIG_SPL_SAVEENV))
480 /*
481 * hexport()
482 */
483
484 /*
485 * Export the data stored in the hash table in linearized form.
486 *
487 * Entries are exported as "name=value" strings, separated by an
488 * arbitrary (non-NUL, of course) separator character. This allows to
489 * use this function both when formatting the U-Boot environment for
490 * external storage (using '\0' as separator), but also when using it
491 * for the "printenv" command to print all variables, simply by using
492 * as '\n" as separator. This can also be used for new features like
493 * exporting the environment data as text file, including the option
494 * for later re-import.
495 *
496 * The entries in the result list will be sorted by ascending key
497 * values.
498 *
499 * If the separator character is different from NUL, then any
500 * separator characters and backslash characters in the values will
501 * be escaped by a preceding backslash in output. This is needed for
502 * example to enable multi-line values, especially when the output
503 * shall later be parsed (for example, for re-import).
504 *
505 * There are several options how the result buffer is handled:
506 *
507 * *resp size
508 * -----------
509 * NULL 0 A string of sufficient length will be allocated.
510 * NULL >0 A string of the size given will be
511 * allocated. An error will be returned if the size is
512 * not sufficient. Any unused bytes in the string will
513 * be '\0'-padded.
514 * !NULL 0 The user-supplied buffer will be used. No length
515 * checking will be performed, i. e. it is assumed that
516 * the buffer size will always be big enough. DANGEROUS.
517 * !NULL >0 The user-supplied buffer will be used. An error will
518 * be returned if the size is not sufficient. Any unused
519 * bytes in the string will be '\0'-padded.
520 */
521
cmpkey(const void * p1,const void * p2)522 static int cmpkey(const void *p1, const void *p2)
523 {
524 ENTRY *e1 = *(ENTRY **) p1;
525 ENTRY *e2 = *(ENTRY **) p2;
526
527 return (strcmp(e1->key, e2->key));
528 }
529
match_string(int flag,const char * str,const char * pat,void * priv)530 static int match_string(int flag, const char *str, const char *pat, void *priv)
531 {
532 switch (flag & H_MATCH_METHOD) {
533 case H_MATCH_IDENT:
534 if (strcmp(str, pat) == 0)
535 return 1;
536 break;
537 case H_MATCH_SUBSTR:
538 if (strstr(str, pat))
539 return 1;
540 break;
541 #ifdef CONFIG_REGEX
542 case H_MATCH_REGEX:
543 {
544 struct slre *slrep = (struct slre *)priv;
545 struct cap caps[slrep->num_caps + 2];
546
547 if (slre_match(slrep, str, strlen(str), caps))
548 return 1;
549 }
550 break;
551 #endif
552 default:
553 printf("## ERROR: unsupported match method: 0x%02x\n",
554 flag & H_MATCH_METHOD);
555 break;
556 }
557 return 0;
558 }
559
match_entry(ENTRY * ep,int flag,int argc,char * const argv[])560 static int match_entry(ENTRY *ep, int flag,
561 int argc, char * const argv[])
562 {
563 int arg;
564 void *priv = NULL;
565
566 for (arg = 0; arg < argc; ++arg) {
567 #ifdef CONFIG_REGEX
568 struct slre slre;
569
570 if (slre_compile(&slre, argv[arg]) == 0) {
571 printf("Error compiling regex: %s\n", slre.err_str);
572 return 0;
573 }
574
575 priv = (void *)&slre;
576 #endif
577 if (flag & H_MATCH_KEY) {
578 if (match_string(flag, ep->key, argv[arg], priv))
579 return 1;
580 }
581 if (flag & H_MATCH_DATA) {
582 if (match_string(flag, ep->data, argv[arg], priv))
583 return 1;
584 }
585 }
586 return 0;
587 }
588
hexport_r(struct hsearch_data * htab,const char sep,int flag,char ** resp,size_t size,int argc,char * const argv[])589 ssize_t hexport_r(struct hsearch_data *htab, const char sep, int flag,
590 char **resp, size_t size,
591 int argc, char * const argv[])
592 {
593 ENTRY *list[htab->size];
594 char *res, *p;
595 size_t totlen;
596 int i, n;
597
598 /* Test for correct arguments. */
599 if ((resp == NULL) || (htab == NULL)) {
600 __set_errno(EINVAL);
601 return (-1);
602 }
603
604 debug("EXPORT table = %p, htab.size = %d, htab.filled = %d, size = %lu\n",
605 htab, htab->size, htab->filled, (ulong)size);
606 /*
607 * Pass 1:
608 * search used entries,
609 * save addresses and compute total length
610 */
611 for (i = 1, n = 0, totlen = 0; i <= htab->size; ++i) {
612
613 if (htab->table[i].used > 0) {
614 ENTRY *ep = &htab->table[i].entry;
615 int found = match_entry(ep, flag, argc, argv);
616
617 if ((argc > 0) && (found == 0))
618 continue;
619
620 if ((flag & H_HIDE_DOT) && ep->key[0] == '.')
621 continue;
622
623 list[n++] = ep;
624
625 totlen += strlen(ep->key) + 2;
626
627 if (sep == '\0') {
628 totlen += strlen(ep->data);
629 } else { /* check if escapes are needed */
630 char *s = ep->data;
631
632 while (*s) {
633 ++totlen;
634 /* add room for needed escape chars */
635 if ((*s == sep) || (*s == '\\'))
636 ++totlen;
637 ++s;
638 }
639 }
640 totlen += 2; /* for '=' and 'sep' char */
641 }
642 }
643
644 #ifdef DEBUG
645 /* Pass 1a: print unsorted list */
646 printf("Unsorted: n=%d\n", n);
647 for (i = 0; i < n; ++i) {
648 printf("\t%3d: %p ==> %-10s => %s\n",
649 i, list[i], list[i]->key, list[i]->data);
650 }
651 #endif
652
653 /* Sort list by keys */
654 qsort(list, n, sizeof(ENTRY *), cmpkey);
655
656 /* Check if the user supplied buffer size is sufficient */
657 if (size) {
658 if (size < totlen + 1) { /* provided buffer too small */
659 printf("Env export buffer too small: %lu, but need %lu\n",
660 (ulong)size, (ulong)totlen + 1);
661 __set_errno(ENOMEM);
662 return (-1);
663 }
664 } else {
665 size = totlen + 1;
666 }
667
668 /* Check if the user provided a buffer */
669 if (*resp) {
670 /* yes; clear it */
671 res = *resp;
672 memset(res, '\0', size);
673 } else {
674 /* no, allocate and clear one */
675 *resp = res = calloc(1, size);
676 if (res == NULL) {
677 __set_errno(ENOMEM);
678 return (-1);
679 }
680 }
681 /*
682 * Pass 2:
683 * export sorted list of result data
684 */
685 for (i = 0, p = res; i < n; ++i) {
686 const char *s;
687
688 s = list[i]->key;
689 while (*s)
690 *p++ = *s++;
691 *p++ = '=';
692
693 s = list[i]->data;
694
695 while (*s) {
696 if ((*s == sep) || (*s == '\\'))
697 *p++ = '\\'; /* escape */
698 *p++ = *s++;
699 }
700 *p++ = sep;
701 }
702 *p = '\0'; /* terminate result */
703
704 return size;
705 }
706 #endif
707
708
709 /*
710 * himport()
711 */
712
713 /*
714 * Check whether variable 'name' is amongst vars[],
715 * and remove all instances by setting the pointer to NULL
716 */
drop_var_from_set(const char * name,int nvars,char * vars[])717 static int drop_var_from_set(const char *name, int nvars, char * vars[])
718 {
719 int i = 0;
720 int res = 0;
721
722 /* No variables specified means process all of them */
723 if (nvars == 0)
724 return 1;
725
726 for (i = 0; i < nvars; i++) {
727 if (vars[i] == NULL)
728 continue;
729 /* If we found it, delete all of them */
730 if (!strcmp(name, vars[i])) {
731 vars[i] = NULL;
732 res = 1;
733 }
734 }
735 if (!res)
736 debug("Skipping non-listed variable %s\n", name);
737
738 return res;
739 }
740
741 /*
742 * Import linearized data into hash table.
743 *
744 * This is the inverse function to hexport(): it takes a linear list
745 * of "name=value" pairs and creates hash table entries from it.
746 *
747 * Entries without "value", i. e. consisting of only "name" or
748 * "name=", will cause this entry to be deleted from the hash table.
749 *
750 * The "flag" argument can be used to control the behaviour: when the
751 * H_NOCLEAR bit is set, then an existing hash table will kept, i. e.
752 * new data will be added to an existing hash table; otherwise, old
753 * data will be discarded and a new hash table will be created.
754 *
755 * The separator character for the "name=value" pairs can be selected,
756 * so we both support importing from externally stored environment
757 * data (separated by NUL characters) and from plain text files
758 * (entries separated by newline characters).
759 *
760 * To allow for nicely formatted text input, leading white space
761 * (sequences of SPACE and TAB chars) is ignored, and entries starting
762 * (after removal of any leading white space) with a '#' character are
763 * considered comments and ignored.
764 *
765 * [NOTE: this means that a variable name cannot start with a '#'
766 * character.]
767 *
768 * When using a non-NUL separator character, backslash is used as
769 * escape character in the value part, allowing for example for
770 * multi-line values.
771 *
772 * In theory, arbitrary separator characters can be used, but only
773 * '\0' and '\n' have really been tested.
774 */
775
himport_r(struct hsearch_data * htab,const char * env,size_t size,const char sep,int flag,int crlf_is_lf,int nvars,char * const vars[])776 int himport_r(struct hsearch_data *htab,
777 const char *env, size_t size, const char sep, int flag,
778 int crlf_is_lf, int nvars, char * const vars[])
779 {
780 char *data, *sp, *dp, *name, *value;
781 char *localvars[nvars];
782 int i;
783
784 /* Test for correct arguments. */
785 if (htab == NULL) {
786 __set_errno(EINVAL);
787 return 0;
788 }
789
790 /* we allocate new space to make sure we can write to the array */
791 if ((data = malloc(size + 1)) == NULL) {
792 debug("himport_r: can't malloc %lu bytes\n", (ulong)size + 1);
793 __set_errno(ENOMEM);
794 return 0;
795 }
796 memcpy(data, env, size);
797 data[size] = '\0';
798 dp = data;
799
800 /* make a local copy of the list of variables */
801 if (nvars)
802 memcpy(localvars, vars, sizeof(vars[0]) * nvars);
803
804 if ((flag & H_NOCLEAR) == 0) {
805 /* Destroy old hash table if one exists */
806 debug("Destroy Hash Table: %p table = %p\n", htab,
807 htab->table);
808 if (htab->table)
809 hdestroy_r(htab);
810 }
811
812 /*
813 * Create new hash table (if needed). The computation of the hash
814 * table size is based on heuristics: in a sample of some 70+
815 * existing systems we found an average size of 39+ bytes per entry
816 * in the environment (for the whole key=value pair). Assuming a
817 * size of 8 per entry (= safety factor of ~5) should provide enough
818 * safety margin for any existing environment definitions and still
819 * allow for more than enough dynamic additions. Note that the
820 * "size" argument is supposed to give the maximum environment size
821 * (CONFIG_ENV_SIZE). This heuristics will result in
822 * unreasonably large numbers (and thus memory footprint) for
823 * big flash environments (>8,000 entries for 64 KB
824 * environment size), so we clip it to a reasonable value.
825 * On the other hand we need to add some more entries for free
826 * space when importing very small buffers. Both boundaries can
827 * be overwritten in the board config file if needed.
828 */
829
830 if (!htab->table) {
831 int nent = CONFIG_ENV_MIN_ENTRIES + size / 8;
832
833 if (nent > CONFIG_ENV_MAX_ENTRIES)
834 nent = CONFIG_ENV_MAX_ENTRIES;
835
836 debug("Create Hash Table: N=%d\n", nent);
837
838 if (hcreate_r(nent, htab) == 0) {
839 free(data);
840 return 0;
841 }
842 }
843
844 if (!size) {
845 free(data);
846 return 1; /* everything OK */
847 }
848 if(crlf_is_lf) {
849 /* Remove Carriage Returns in front of Line Feeds */
850 unsigned ignored_crs = 0;
851 for(;dp < data + size && *dp; ++dp) {
852 if(*dp == '\r' &&
853 dp < data + size - 1 && *(dp+1) == '\n')
854 ++ignored_crs;
855 else
856 *(dp-ignored_crs) = *dp;
857 }
858 size -= ignored_crs;
859 dp = data;
860 }
861 /* Parse environment; allow for '\0' and 'sep' as separators */
862 do {
863 ENTRY e, *rv;
864
865 /* skip leading white space */
866 while (isblank(*dp))
867 ++dp;
868
869 /* skip comment lines */
870 if (*dp == '#') {
871 while (*dp && (*dp != sep))
872 ++dp;
873 ++dp;
874 continue;
875 }
876
877 /* parse name */
878 for (name = dp; *dp != '=' && *dp && *dp != sep; ++dp)
879 ;
880
881 /* deal with "name" and "name=" entries (delete var) */
882 if (*dp == '\0' || *(dp + 1) == '\0' ||
883 *dp == sep || *(dp + 1) == sep) {
884 if (*dp == '=')
885 *dp++ = '\0';
886 *dp++ = '\0'; /* terminate name */
887
888 debug("DELETE CANDIDATE: \"%s\"\n", name);
889 if (!drop_var_from_set(name, nvars, localvars))
890 continue;
891
892 if (hdelete_r(name, htab, flag) == 0)
893 debug("DELETE ERROR ##############################\n");
894
895 continue;
896 }
897 *dp++ = '\0'; /* terminate name */
898
899 /* parse value; deal with escapes */
900 for (value = sp = dp; *dp && (*dp != sep); ++dp) {
901 if ((*dp == '\\') && *(dp + 1))
902 ++dp;
903 *sp++ = *dp;
904 }
905 *sp++ = '\0'; /* terminate value */
906 ++dp;
907
908 if (*name == 0) {
909 debug("INSERT: unable to use an empty key\n");
910 __set_errno(EINVAL);
911 free(data);
912 return 0;
913 }
914
915 /* Skip variables which are not supposed to be processed */
916 if (!drop_var_from_set(name, nvars, localvars))
917 continue;
918
919 /* enter into hash table */
920 e.key = name;
921 e.data = value;
922
923 hsearch_r(e, ENTER, &rv, htab, flag);
924 if (rv == NULL)
925 printf("himport_r: can't insert \"%s=%s\" into hash table\n",
926 name, value);
927
928 debug("INSERT: table %p, filled %d/%d rv %p ==> name=\"%s\" value=\"%s\"\n",
929 htab, htab->filled, htab->size,
930 rv, name, value);
931 } while ((dp < data + size) && *dp); /* size check needed for text */
932 /* without '\0' termination */
933 debug("INSERT: free(data = %p)\n", data);
934 free(data);
935
936 /* process variables which were not considered */
937 for (i = 0; i < nvars; i++) {
938 if (localvars[i] == NULL)
939 continue;
940 /*
941 * All variables which were not deleted from the variable list
942 * were not present in the imported env
943 * This could mean two things:
944 * a) if the variable was present in current env, we delete it
945 * b) if the variable was not present in current env, we notify
946 * it might be a typo
947 */
948 if (hdelete_r(localvars[i], htab, flag) == 0)
949 printf("WARNING: '%s' neither in running nor in imported env!\n", localvars[i]);
950 else
951 printf("WARNING: '%s' not in imported env, deleting it!\n", localvars[i]);
952 }
953
954 debug("INSERT: done\n");
955 return 1; /* everything OK */
956 }
957
958 /*
959 * hwalk_r()
960 */
961
962 /*
963 * Walk all of the entries in the hash, calling the callback for each one.
964 * this allows some generic operation to be performed on each element.
965 */
hwalk_r(struct hsearch_data * htab,int (* callback)(ENTRY *))966 int hwalk_r(struct hsearch_data *htab, int (*callback)(ENTRY *))
967 {
968 int i;
969 int retval;
970
971 for (i = 1; i <= htab->size; ++i) {
972 if (htab->table[i].used > 0) {
973 retval = callback(&htab->table[i].entry);
974 if (retval)
975 return retval;
976 }
977 }
978
979 return 0;
980 }
981