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 <log.h>
17 #include <malloc.h>
18 #include <sort.h>
19
20 #ifdef USE_HOSTCC /* HOST build */
21 # include <string.h>
22 # include <assert.h>
23 # include <ctype.h>
24
25 # ifndef debug
26 # ifdef DEBUG
27 # define debug(fmt,args...) printf(fmt ,##args)
28 # else
29 # define debug(fmt,args...)
30 # endif
31 # endif
32 #else /* U-Boot build */
33 # include <common.h>
34 # include <linux/string.h>
35 # include <linux/ctype.h>
36 #endif
37
38 #define USED_FREE 0
39 #define USED_DELETED -1
40
41 #include <env_callback.h>
42 #include <env_flags.h>
43 #include <search.h>
44 #include <slre.h>
45
46 /*
47 * [Aho,Sethi,Ullman] Compilers: Principles, Techniques and Tools, 1986
48 * [Knuth] The Art of Computer Programming, part 3 (6.4)
49 */
50
51 /*
52 * The reentrant version has no static variables to maintain the state.
53 * Instead the interface of all functions is extended to take an argument
54 * which describes the current status.
55 */
56
57 struct env_entry_node {
58 int used;
59 struct env_entry entry;
60 };
61
62
63 static void _hdelete(const char *key, struct hsearch_data *htab,
64 struct env_entry *ep, int idx);
65
66 /*
67 * hcreate()
68 */
69
70 /*
71 * For the used double hash method the table size has to be a prime. To
72 * correct the user given table size we need a prime test. This trivial
73 * algorithm is adequate because
74 * a) the code is (most probably) called a few times per program run and
75 * b) the number is small because the table must fit in the core
76 * */
isprime(unsigned int number)77 static int isprime(unsigned int number)
78 {
79 /* no even number will be passed */
80 unsigned int div = 3;
81
82 while (div * div < number && number % div != 0)
83 div += 2;
84
85 return number % div != 0;
86 }
87
88 /*
89 * Before using the hash table we must allocate memory for it.
90 * Test for an existing table are done. We allocate one element
91 * more as the found prime number says. This is done for more effective
92 * indexing as explained in the comment for the hsearch function.
93 * The contents of the table is zeroed, especially the field used
94 * becomes zero.
95 */
96
hcreate_r(size_t nel,struct hsearch_data * htab)97 int hcreate_r(size_t nel, struct hsearch_data *htab)
98 {
99 /* Test for correct arguments. */
100 if (htab == NULL) {
101 __set_errno(EINVAL);
102 return 0;
103 }
104
105 /* There is still another table active. Return with error. */
106 if (htab->table != NULL) {
107 __set_errno(EINVAL);
108 return 0;
109 }
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 = (struct env_entry_node *)calloc(htab->size + 1,
121 sizeof(struct env_entry_node));
122 if (htab->table == NULL) {
123 __set_errno(ENOMEM);
124 return 0;
125 }
126
127 /* everything went alright */
128 return 1;
129 }
130
131
132 /*
133 * hdestroy()
134 */
135
136 /*
137 * After using the hash table it has to be destroyed. The used memory can
138 * be freed and the local static variable can be marked as not used.
139 */
140
hdestroy_r(struct hsearch_data * htab)141 void hdestroy_r(struct hsearch_data *htab)
142 {
143 int i;
144
145 /* Test for correct arguments. */
146 if (htab == NULL) {
147 __set_errno(EINVAL);
148 return;
149 }
150
151 /* free used memory */
152 for (i = 1; i <= htab->size; ++i) {
153 if (htab->table[i].used > 0) {
154 struct env_entry *ep = &htab->table[i].entry;
155
156 free((void *)ep->key);
157 free(ep->data);
158 }
159 }
160 free(htab->table);
161
162 /* the sign for an existing table is an value != NULL in htable */
163 htab->table = NULL;
164 }
165
166 /*
167 * hsearch()
168 */
169
170 /*
171 * This is the search function. It uses double hashing with open addressing.
172 * The argument item.key has to be a pointer to an zero terminated, most
173 * probably strings of chars. The function for generating a number of the
174 * strings is simple but fast. It can be replaced by a more complex function
175 * like ajw (see [Aho,Sethi,Ullman]) if the needs are shown.
176 *
177 * We use an trick to speed up the lookup. The table is created by hcreate
178 * with one more element available. This enables us to use the index zero
179 * special. This index will never be used because we store the first hash
180 * index in the field used where zero means not used. Every other value
181 * means used. The used field can be used as a first fast comparison for
182 * equality of the stored and the parameter value. This helps to prevent
183 * unnecessary expensive calls of strcmp.
184 *
185 * This implementation differs from the standard library version of
186 * this function in a number of ways:
187 *
188 * - While the standard version does not make any assumptions about
189 * the type of the stored data objects at all, this implementation
190 * works with NUL terminated strings only.
191 * - Instead of storing just pointers to the original objects, we
192 * create local copies so the caller does not need to care about the
193 * data any more.
194 * - The standard implementation does not provide a way to update an
195 * existing entry. This version will create a new entry or update an
196 * existing one when both "action == ENV_ENTER" and "item.data != NULL".
197 * - Instead of returning 1 on success, we return the index into the
198 * internal hash table, which is also guaranteed to be positive.
199 * This allows us direct access to the found hash table slot for
200 * example for functions like hdelete().
201 */
202
hmatch_r(const char * match,int last_idx,struct env_entry ** retval,struct hsearch_data * htab)203 int hmatch_r(const char *match, int last_idx, struct env_entry **retval,
204 struct hsearch_data *htab)
205 {
206 unsigned int idx;
207 size_t key_len = strlen(match);
208
209 for (idx = last_idx + 1; idx < htab->size; ++idx) {
210 if (htab->table[idx].used <= 0)
211 continue;
212 if (!strncmp(match, htab->table[idx].entry.key, key_len)) {
213 *retval = &htab->table[idx].entry;
214 return idx;
215 }
216 }
217
218 __set_errno(ESRCH);
219 *retval = NULL;
220 return 0;
221 }
222
223 static int
do_callback(const struct env_entry * e,const char * name,const char * value,enum env_op op,int flags)224 do_callback(const struct env_entry *e, const char *name, const char *value,
225 enum env_op op, int flags)
226 {
227 #ifndef CONFIG_SPL_BUILD
228 if (e->callback)
229 return e->callback(name, value, op, flags);
230 #endif
231 return 0;
232 }
233
234 /*
235 * Compare an existing entry with the desired key, and overwrite if the action
236 * is ENV_ENTER. This is simply a helper function for hsearch_r().
237 */
_compare_and_overwrite_entry(struct env_entry item,enum env_action action,struct env_entry ** retval,struct hsearch_data * htab,int flag,unsigned int hval,unsigned int idx)238 static inline int _compare_and_overwrite_entry(struct env_entry item,
239 enum env_action action, struct env_entry **retval,
240 struct hsearch_data *htab, int flag, unsigned int hval,
241 unsigned int idx)
242 {
243 if (htab->table[idx].used == hval
244 && strcmp(item.key, htab->table[idx].entry.key) == 0) {
245 /* Overwrite existing value? */
246 if (action == ENV_ENTER && item.data) {
247 /* check for permission */
248 if (htab->change_ok != NULL && htab->change_ok(
249 &htab->table[idx].entry, item.data,
250 env_op_overwrite, flag)) {
251 debug("change_ok() rejected setting variable "
252 "%s, skipping it!\n", item.key);
253 __set_errno(EPERM);
254 *retval = NULL;
255 return 0;
256 }
257
258 /* If there is a callback, call it */
259 if (do_callback(&htab->table[idx].entry, item.key,
260 item.data, env_op_overwrite, flag)) {
261 debug("callback() rejected setting variable "
262 "%s, skipping it!\n", item.key);
263 __set_errno(EINVAL);
264 *retval = NULL;
265 return 0;
266 }
267
268 free(htab->table[idx].entry.data);
269 htab->table[idx].entry.data = strdup(item.data);
270 if (!htab->table[idx].entry.data) {
271 __set_errno(ENOMEM);
272 *retval = NULL;
273 return 0;
274 }
275 }
276 /* return found entry */
277 *retval = &htab->table[idx].entry;
278 return idx;
279 }
280 /* keep searching */
281 return -1;
282 }
283
hsearch_r(struct env_entry item,enum env_action action,struct env_entry ** retval,struct hsearch_data * htab,int flag)284 int hsearch_r(struct env_entry item, enum env_action action,
285 struct env_entry **retval, struct hsearch_data *htab, int flag)
286 {
287 unsigned int hval;
288 unsigned int count;
289 unsigned int len = strlen(item.key);
290 unsigned int idx;
291 unsigned int first_deleted = 0;
292 int ret;
293
294 /* Compute an value for the given string. Perhaps use a better method. */
295 hval = len;
296 count = len;
297 while (count-- > 0) {
298 hval <<= 4;
299 hval += item.key[count];
300 }
301
302 /*
303 * First hash function:
304 * simply take the modul but prevent zero.
305 */
306 hval %= htab->size;
307 if (hval == 0)
308 ++hval;
309
310 /* The first index tried. */
311 idx = hval;
312
313 if (htab->table[idx].used) {
314 /*
315 * Further action might be required according to the
316 * action value.
317 */
318 unsigned hval2;
319
320 if (htab->table[idx].used == USED_DELETED)
321 first_deleted = idx;
322
323 ret = _compare_and_overwrite_entry(item, action, retval, htab,
324 flag, hval, idx);
325 if (ret != -1)
326 return ret;
327
328 /*
329 * Second hash function:
330 * as suggested in [Knuth]
331 */
332 hval2 = 1 + hval % (htab->size - 2);
333
334 do {
335 /*
336 * Because SIZE is prime this guarantees to
337 * step through all available indices.
338 */
339 if (idx <= hval2)
340 idx = htab->size + idx - hval2;
341 else
342 idx -= hval2;
343
344 /*
345 * If we visited all entries leave the loop
346 * unsuccessfully.
347 */
348 if (idx == hval)
349 break;
350
351 if (htab->table[idx].used == USED_DELETED
352 && !first_deleted)
353 first_deleted = idx;
354
355 /* If entry is found use it. */
356 ret = _compare_and_overwrite_entry(item, action, retval,
357 htab, flag, hval, idx);
358 if (ret != -1)
359 return ret;
360 }
361 while (htab->table[idx].used != USED_FREE);
362 }
363
364 /* An empty bucket has been found. */
365 if (action == ENV_ENTER) {
366 /*
367 * If table is full and another entry should be
368 * entered return with error.
369 */
370 if (htab->filled == htab->size) {
371 __set_errno(ENOMEM);
372 *retval = NULL;
373 return 0;
374 }
375
376 /*
377 * Create new entry;
378 * create copies of item.key and item.data
379 */
380 if (first_deleted)
381 idx = first_deleted;
382
383 htab->table[idx].used = hval;
384 htab->table[idx].entry.key = strdup(item.key);
385 htab->table[idx].entry.data = strdup(item.data);
386 if (!htab->table[idx].entry.key ||
387 !htab->table[idx].entry.data) {
388 __set_errno(ENOMEM);
389 *retval = NULL;
390 return 0;
391 }
392
393 ++htab->filled;
394
395 /* This is a new entry, so look up a possible callback */
396 env_callback_init(&htab->table[idx].entry);
397 /* Also look for flags */
398 env_flags_init(&htab->table[idx].entry);
399
400 /* check for permission */
401 if (htab->change_ok != NULL && htab->change_ok(
402 &htab->table[idx].entry, item.data, env_op_create, flag)) {
403 debug("change_ok() rejected setting variable "
404 "%s, skipping it!\n", item.key);
405 _hdelete(item.key, htab, &htab->table[idx].entry, idx);
406 __set_errno(EPERM);
407 *retval = NULL;
408 return 0;
409 }
410
411 /* If there is a callback, call it */
412 if (do_callback(&htab->table[idx].entry, item.key, item.data,
413 env_op_create, flag)) {
414 debug("callback() rejected setting variable "
415 "%s, skipping it!\n", item.key);
416 _hdelete(item.key, htab, &htab->table[idx].entry, idx);
417 __set_errno(EINVAL);
418 *retval = NULL;
419 return 0;
420 }
421
422 /* return new entry */
423 *retval = &htab->table[idx].entry;
424 return 1;
425 }
426
427 __set_errno(ESRCH);
428 *retval = NULL;
429 return 0;
430 }
431
432
433 /*
434 * hdelete()
435 */
436
437 /*
438 * The standard implementation of hsearch(3) does not provide any way
439 * to delete any entries from the hash table. We extend the code to
440 * do that.
441 */
442
_hdelete(const char * key,struct hsearch_data * htab,struct env_entry * ep,int idx)443 static void _hdelete(const char *key, struct hsearch_data *htab,
444 struct env_entry *ep, int idx)
445 {
446 /* free used entry */
447 debug("hdelete: DELETING key \"%s\"\n", key);
448 free((void *)ep->key);
449 free(ep->data);
450 ep->flags = 0;
451 htab->table[idx].used = USED_DELETED;
452
453 --htab->filled;
454 }
455
hdelete_r(const char * key,struct hsearch_data * htab,int flag)456 int hdelete_r(const char *key, struct hsearch_data *htab, int flag)
457 {
458 struct env_entry e, *ep;
459 int idx;
460
461 debug("hdelete: DELETE key \"%s\"\n", key);
462
463 e.key = (char *)key;
464
465 idx = hsearch_r(e, ENV_FIND, &ep, htab, 0);
466 if (idx == 0) {
467 __set_errno(ESRCH);
468 return -ENOENT; /* not found */
469 }
470
471 /* Check for permission */
472 if (htab->change_ok != NULL &&
473 htab->change_ok(ep, NULL, env_op_delete, flag)) {
474 debug("change_ok() rejected deleting variable "
475 "%s, skipping it!\n", key);
476 __set_errno(EPERM);
477 return -EPERM;
478 }
479
480 /* If there is a callback, call it */
481 if (do_callback(&htab->table[idx].entry, key, NULL,
482 env_op_delete, flag)) {
483 debug("callback() rejected deleting variable "
484 "%s, skipping it!\n", key);
485 __set_errno(EINVAL);
486 return -EINVAL;
487 }
488
489 _hdelete(key, htab, ep, idx);
490
491 return 0;
492 }
493
494 #if !(defined(CONFIG_SPL_BUILD) && !defined(CONFIG_SPL_SAVEENV))
495 /*
496 * hexport()
497 */
498
499 /*
500 * Export the data stored in the hash table in linearized form.
501 *
502 * Entries are exported as "name=value" strings, separated by an
503 * arbitrary (non-NUL, of course) separator character. This allows to
504 * use this function both when formatting the U-Boot environment for
505 * external storage (using '\0' as separator), but also when using it
506 * for the "printenv" command to print all variables, simply by using
507 * as '\n" as separator. This can also be used for new features like
508 * exporting the environment data as text file, including the option
509 * for later re-import.
510 *
511 * The entries in the result list will be sorted by ascending key
512 * values.
513 *
514 * If the separator character is different from NUL, then any
515 * separator characters and backslash characters in the values will
516 * be escaped by a preceding backslash in output. This is needed for
517 * example to enable multi-line values, especially when the output
518 * shall later be parsed (for example, for re-import).
519 *
520 * There are several options how the result buffer is handled:
521 *
522 * *resp size
523 * -----------
524 * NULL 0 A string of sufficient length will be allocated.
525 * NULL >0 A string of the size given will be
526 * allocated. An error will be returned if the size is
527 * not sufficient. Any unused bytes in the string will
528 * be '\0'-padded.
529 * !NULL 0 The user-supplied buffer will be used. No length
530 * checking will be performed, i. e. it is assumed that
531 * the buffer size will always be big enough. DANGEROUS.
532 * !NULL >0 The user-supplied buffer will be used. An error will
533 * be returned if the size is not sufficient. Any unused
534 * bytes in the string will be '\0'-padded.
535 */
536
cmpkey(const void * p1,const void * p2)537 static int cmpkey(const void *p1, const void *p2)
538 {
539 struct env_entry *e1 = *(struct env_entry **)p1;
540 struct env_entry *e2 = *(struct env_entry **)p2;
541
542 return (strcmp(e1->key, e2->key));
543 }
544
match_string(int flag,const char * str,const char * pat,void * priv)545 static int match_string(int flag, const char *str, const char *pat, void *priv)
546 {
547 switch (flag & H_MATCH_METHOD) {
548 case H_MATCH_IDENT:
549 if (strcmp(str, pat) == 0)
550 return 1;
551 break;
552 case H_MATCH_SUBSTR:
553 if (strstr(str, pat))
554 return 1;
555 break;
556 #ifdef CONFIG_REGEX
557 case H_MATCH_REGEX:
558 {
559 struct slre *slrep = (struct slre *)priv;
560
561 if (slre_match(slrep, str, strlen(str), NULL))
562 return 1;
563 }
564 break;
565 #endif
566 default:
567 printf("## ERROR: unsupported match method: 0x%02x\n",
568 flag & H_MATCH_METHOD);
569 break;
570 }
571 return 0;
572 }
573
match_entry(struct env_entry * ep,int flag,int argc,char * const argv[])574 static int match_entry(struct env_entry *ep, int flag, int argc,
575 char *const argv[])
576 {
577 int arg;
578 void *priv = NULL;
579
580 for (arg = 0; arg < argc; ++arg) {
581 #ifdef CONFIG_REGEX
582 struct slre slre;
583
584 if (slre_compile(&slre, argv[arg]) == 0) {
585 printf("Error compiling regex: %s\n", slre.err_str);
586 return 0;
587 }
588
589 priv = (void *)&slre;
590 #endif
591 if (flag & H_MATCH_KEY) {
592 if (match_string(flag, ep->key, argv[arg], priv))
593 return 1;
594 }
595 if (flag & H_MATCH_DATA) {
596 if (match_string(flag, ep->data, argv[arg], priv))
597 return 1;
598 }
599 }
600 return 0;
601 }
602
hexport_r(struct hsearch_data * htab,const char sep,int flag,char ** resp,size_t size,int argc,char * const argv[])603 ssize_t hexport_r(struct hsearch_data *htab, const char sep, int flag,
604 char **resp, size_t size,
605 int argc, char *const argv[])
606 {
607 struct env_entry *list[htab->size];
608 char *res, *p;
609 size_t totlen;
610 int i, n;
611
612 /* Test for correct arguments. */
613 if ((resp == NULL) || (htab == NULL)) {
614 __set_errno(EINVAL);
615 return (-1);
616 }
617
618 debug("EXPORT table = %p, htab.size = %d, htab.filled = %d, size = %lu\n",
619 htab, htab->size, htab->filled, (ulong)size);
620 /*
621 * Pass 1:
622 * search used entries,
623 * save addresses and compute total length
624 */
625 for (i = 1, n = 0, totlen = 0; i <= htab->size; ++i) {
626
627 if (htab->table[i].used > 0) {
628 struct env_entry *ep = &htab->table[i].entry;
629 int found = match_entry(ep, flag, argc, argv);
630
631 if ((argc > 0) && (found == 0))
632 continue;
633
634 if ((flag & H_HIDE_DOT) && ep->key[0] == '.')
635 continue;
636
637 list[n++] = ep;
638
639 totlen += strlen(ep->key);
640
641 if (sep == '\0') {
642 totlen += strlen(ep->data);
643 } else { /* check if escapes are needed */
644 char *s = ep->data;
645
646 while (*s) {
647 ++totlen;
648 /* add room for needed escape chars */
649 if ((*s == sep) || (*s == '\\'))
650 ++totlen;
651 ++s;
652 }
653 }
654 totlen += 2; /* for '=' and 'sep' char */
655 }
656 }
657
658 #ifdef DEBUG
659 /* Pass 1a: print unsorted list */
660 printf("Unsorted: n=%d\n", n);
661 for (i = 0; i < n; ++i) {
662 printf("\t%3d: %p ==> %-10s => %s\n",
663 i, list[i], list[i]->key, list[i]->data);
664 }
665 #endif
666
667 /* Sort list by keys */
668 qsort(list, n, sizeof(struct env_entry *), cmpkey);
669
670 /* Check if the user supplied buffer size is sufficient */
671 if (size) {
672 if (size < totlen + 1) { /* provided buffer too small */
673 printf("Env export buffer too small: %lu, but need %lu\n",
674 (ulong)size, (ulong)totlen + 1);
675 __set_errno(ENOMEM);
676 return (-1);
677 }
678 } else {
679 size = totlen + 1;
680 }
681
682 /* Check if the user provided a buffer */
683 if (*resp) {
684 /* yes; clear it */
685 res = *resp;
686 memset(res, '\0', size);
687 } else {
688 /* no, allocate and clear one */
689 *resp = res = calloc(1, size);
690 if (res == NULL) {
691 __set_errno(ENOMEM);
692 return (-1);
693 }
694 }
695 /*
696 * Pass 2:
697 * export sorted list of result data
698 */
699 for (i = 0, p = res; i < n; ++i) {
700 const char *s;
701
702 s = list[i]->key;
703 while (*s)
704 *p++ = *s++;
705 *p++ = '=';
706
707 s = list[i]->data;
708
709 while (*s) {
710 if ((*s == sep) || (*s == '\\'))
711 *p++ = '\\'; /* escape */
712 *p++ = *s++;
713 }
714 *p++ = sep;
715 }
716 *p = '\0'; /* terminate result */
717
718 return size;
719 }
720 #endif
721
722
723 /*
724 * himport()
725 */
726
727 /*
728 * Check whether variable 'name' is amongst vars[],
729 * and remove all instances by setting the pointer to NULL
730 */
drop_var_from_set(const char * name,int nvars,char * vars[])731 static int drop_var_from_set(const char *name, int nvars, char * vars[])
732 {
733 int i = 0;
734 int res = 0;
735
736 /* No variables specified means process all of them */
737 if (nvars == 0)
738 return 1;
739
740 for (i = 0; i < nvars; i++) {
741 if (vars[i] == NULL)
742 continue;
743 /* If we found it, delete all of them */
744 if (!strcmp(name, vars[i])) {
745 vars[i] = NULL;
746 res = 1;
747 }
748 }
749 if (!res)
750 debug("Skipping non-listed variable %s\n", name);
751
752 return res;
753 }
754
755 /*
756 * Import linearized data into hash table.
757 *
758 * This is the inverse function to hexport(): it takes a linear list
759 * of "name=value" pairs and creates hash table entries from it.
760 *
761 * Entries without "value", i. e. consisting of only "name" or
762 * "name=", will cause this entry to be deleted from the hash table.
763 *
764 * The "flag" argument can be used to control the behaviour: when the
765 * H_NOCLEAR bit is set, then an existing hash table will kept, i. e.
766 * new data will be added to an existing hash table; otherwise, if no
767 * vars are passed, old data will be discarded and a new hash table
768 * will be created. If vars are passed, passed vars that are not in
769 * the linear list of "name=value" pairs will be removed from the
770 * current hash table.
771 *
772 * The separator character for the "name=value" pairs can be selected,
773 * so we both support importing from externally stored environment
774 * data (separated by NUL characters) and from plain text files
775 * (entries separated by newline characters).
776 *
777 * To allow for nicely formatted text input, leading white space
778 * (sequences of SPACE and TAB chars) is ignored, and entries starting
779 * (after removal of any leading white space) with a '#' character are
780 * considered comments and ignored.
781 *
782 * [NOTE: this means that a variable name cannot start with a '#'
783 * character.]
784 *
785 * When using a non-NUL separator character, backslash is used as
786 * escape character in the value part, allowing for example for
787 * multi-line values.
788 *
789 * In theory, arbitrary separator characters can be used, but only
790 * '\0' and '\n' have really been tested.
791 */
792
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[])793 int himport_r(struct hsearch_data *htab,
794 const char *env, size_t size, const char sep, int flag,
795 int crlf_is_lf, int nvars, char * const vars[])
796 {
797 char *data, *sp, *dp, *name, *value;
798 char *localvars[nvars];
799 int i;
800
801 /* Test for correct arguments. */
802 if (htab == NULL) {
803 __set_errno(EINVAL);
804 return 0;
805 }
806
807 /* we allocate new space to make sure we can write to the array */
808 if ((data = malloc(size + 1)) == NULL) {
809 debug("himport_r: can't malloc %lu bytes\n", (ulong)size + 1);
810 __set_errno(ENOMEM);
811 return 0;
812 }
813 memcpy(data, env, size);
814 data[size] = '\0';
815 dp = data;
816
817 /* make a local copy of the list of variables */
818 if (nvars)
819 memcpy(localvars, vars, sizeof(vars[0]) * nvars);
820
821 #if CONFIG_IS_ENABLED(ENV_APPEND)
822 flag |= H_NOCLEAR;
823 #endif
824
825 if ((flag & H_NOCLEAR) == 0 && !nvars) {
826 /* Destroy old hash table if one exists */
827 debug("Destroy Hash Table: %p table = %p\n", htab,
828 htab->table);
829 if (htab->table)
830 hdestroy_r(htab);
831 }
832
833 /*
834 * Create new hash table (if needed). The computation of the hash
835 * table size is based on heuristics: in a sample of some 70+
836 * existing systems we found an average size of 39+ bytes per entry
837 * in the environment (for the whole key=value pair). Assuming a
838 * size of 8 per entry (= safety factor of ~5) should provide enough
839 * safety margin for any existing environment definitions and still
840 * allow for more than enough dynamic additions. Note that the
841 * "size" argument is supposed to give the maximum environment size
842 * (CONFIG_ENV_SIZE). This heuristics will result in
843 * unreasonably large numbers (and thus memory footprint) for
844 * big flash environments (>8,000 entries for 64 KB
845 * environment size), so we clip it to a reasonable value.
846 * On the other hand we need to add some more entries for free
847 * space when importing very small buffers. Both boundaries can
848 * be overwritten in the board config file if needed.
849 */
850
851 if (!htab->table) {
852 int nent = CONFIG_ENV_MIN_ENTRIES + size / 8;
853
854 if (nent > CONFIG_ENV_MAX_ENTRIES)
855 nent = CONFIG_ENV_MAX_ENTRIES;
856
857 debug("Create Hash Table: N=%d\n", nent);
858
859 if (hcreate_r(nent, htab) == 0) {
860 free(data);
861 return 0;
862 }
863 }
864
865 if (!size) {
866 free(data);
867 return 1; /* everything OK */
868 }
869 if(crlf_is_lf) {
870 /* Remove Carriage Returns in front of Line Feeds */
871 unsigned ignored_crs = 0;
872 for(;dp < data + size && *dp; ++dp) {
873 if(*dp == '\r' &&
874 dp < data + size - 1 && *(dp+1) == '\n')
875 ++ignored_crs;
876 else
877 *(dp-ignored_crs) = *dp;
878 }
879 size -= ignored_crs;
880 dp = data;
881 }
882 /* Parse environment; allow for '\0' and 'sep' as separators */
883 do {
884 struct env_entry e, *rv;
885
886 /* skip leading white space */
887 while (isblank(*dp))
888 ++dp;
889
890 /* skip comment lines */
891 if (*dp == '#') {
892 while (*dp && (*dp != sep))
893 ++dp;
894 ++dp;
895 continue;
896 }
897
898 /* parse name */
899 for (name = dp; *dp != '=' && *dp && *dp != sep; ++dp)
900 ;
901
902 /* deal with "name" and "name=" entries (delete var) */
903 if (*dp == '\0' || *(dp + 1) == '\0' ||
904 *dp == sep || *(dp + 1) == sep) {
905 if (*dp == '=')
906 *dp++ = '\0';
907 *dp++ = '\0'; /* terminate name */
908
909 debug("DELETE CANDIDATE: \"%s\"\n", name);
910 if (!drop_var_from_set(name, nvars, localvars))
911 continue;
912
913 if (hdelete_r(name, htab, flag))
914 debug("DELETE ERROR ##############################\n");
915
916 continue;
917 }
918 *dp++ = '\0'; /* terminate name */
919
920 /* parse value; deal with escapes */
921 for (value = sp = dp; *dp && (*dp != sep); ++dp) {
922 if ((*dp == '\\') && *(dp + 1))
923 ++dp;
924 *sp++ = *dp;
925 }
926 *sp++ = '\0'; /* terminate value */
927 ++dp;
928
929 if (*name == 0) {
930 debug("INSERT: unable to use an empty key\n");
931 __set_errno(EINVAL);
932 free(data);
933 return 0;
934 }
935
936 /* Skip variables which are not supposed to be processed */
937 if (!drop_var_from_set(name, nvars, localvars))
938 continue;
939
940 /* enter into hash table */
941 e.key = name;
942 e.data = value;
943
944 hsearch_r(e, ENV_ENTER, &rv, htab, flag);
945 #if !IS_ENABLED(CONFIG_ENV_WRITEABLE_LIST)
946 if (rv == NULL) {
947 printf("himport_r: can't insert \"%s=%s\" into hash table\n",
948 name, value);
949 }
950 #endif
951
952 debug("INSERT: table %p, filled %d/%d rv %p ==> name=\"%s\" value=\"%s\"\n",
953 htab, htab->filled, htab->size,
954 rv, name, value);
955 } while ((dp < data + size) && *dp); /* size check needed for text */
956 /* without '\0' termination */
957 debug("INSERT: free(data = %p)\n", data);
958 free(data);
959
960 if (flag & H_NOCLEAR)
961 goto end;
962
963 /* process variables which were not considered */
964 for (i = 0; i < nvars; i++) {
965 if (localvars[i] == NULL)
966 continue;
967 /*
968 * All variables which were not deleted from the variable list
969 * were not present in the imported env
970 * This could mean two things:
971 * a) if the variable was present in current env, we delete it
972 * b) if the variable was not present in current env, we notify
973 * it might be a typo
974 */
975 if (hdelete_r(localvars[i], htab, flag))
976 printf("WARNING: '%s' neither in running nor in imported env!\n", localvars[i]);
977 else
978 printf("WARNING: '%s' not in imported env, deleting it!\n", localvars[i]);
979 }
980
981 end:
982 debug("INSERT: done\n");
983 return 1; /* everything OK */
984 }
985
986 /*
987 * hwalk_r()
988 */
989
990 /*
991 * Walk all of the entries in the hash, calling the callback for each one.
992 * this allows some generic operation to be performed on each element.
993 */
hwalk_r(struct hsearch_data * htab,int (* callback)(struct env_entry * entry))994 int hwalk_r(struct hsearch_data *htab, int (*callback)(struct env_entry *entry))
995 {
996 int i;
997 int retval;
998
999 for (i = 1; i <= htab->size; ++i) {
1000 if (htab->table[i].used > 0) {
1001 retval = callback(&htab->table[i].entry);
1002 if (retval)
1003 return retval;
1004 }
1005 }
1006
1007 return 0;
1008 }
1009