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 #include <sort.h>
18
19 #ifdef USE_HOSTCC /* HOST build */
20 # include <string.h>
21 # include <assert.h>
22 # include <ctype.h>
23
24 # ifndef debug
25 # ifdef DEBUG
26 # define debug(fmt,args...) printf(fmt ,##args)
27 # else
28 # define debug(fmt,args...)
29 # endif
30 # endif
31 #else /* U-Boot build */
32 # include <common.h>
33 # include <linux/string.h>
34 # include <linux/ctype.h>
35 #endif
36
37 #ifndef CONFIG_ENV_MIN_ENTRIES /* minimum number of entries */
38 #define CONFIG_ENV_MIN_ENTRIES 64
39 #endif
40 #ifndef CONFIG_ENV_MAX_ENTRIES /* maximum number of entries */
41 #define CONFIG_ENV_MAX_ENTRIES 512
42 #endif
43
44 #define USED_FREE 0
45 #define USED_DELETED -1
46
47 #include <env_callback.h>
48 #include <env_flags.h>
49 #include <search.h>
50 #include <slre.h>
51
52 /*
53 * [Aho,Sethi,Ullman] Compilers: Principles, Techniques and Tools, 1986
54 * [Knuth] The Art of Computer Programming, part 3 (6.4)
55 */
56
57 /*
58 * The reentrant version has no static variables to maintain the state.
59 * Instead the interface of all functions is extended to take an argument
60 * which describes the current status.
61 */
62
63 struct env_entry_node {
64 int used;
65 struct env_entry entry;
66 };
67
68
69 static void _hdelete(const char *key, struct hsearch_data *htab,
70 struct env_entry *ep, int idx);
71
72 /*
73 * hcreate()
74 */
75
76 /*
77 * For the used double hash method the table size has to be a prime. To
78 * correct the user given table size we need a prime test. This trivial
79 * algorithm is adequate because
80 * a) the code is (most probably) called a few times per program run and
81 * b) the number is small because the table must fit in the core
82 * */
isprime(unsigned int number)83 static int isprime(unsigned int number)
84 {
85 /* no even number will be passed */
86 unsigned int div = 3;
87
88 while (div * div < number && number % div != 0)
89 div += 2;
90
91 return number % div != 0;
92 }
93
94 /*
95 * Before using the hash table we must allocate memory for it.
96 * Test for an existing table are done. We allocate one element
97 * more as the found prime number says. This is done for more effective
98 * indexing as explained in the comment for the hsearch function.
99 * The contents of the table is zeroed, especially the field used
100 * becomes zero.
101 */
102
hcreate_r(size_t nel,struct hsearch_data * htab)103 int hcreate_r(size_t nel, struct hsearch_data *htab)
104 {
105 /* Test for correct arguments. */
106 if (htab == NULL) {
107 __set_errno(EINVAL);
108 return 0;
109 }
110
111 /* There is still another table active. Return with error. */
112 if (htab->table != NULL)
113 return 0;
114
115 /* Change nel to the first prime number not smaller as nel. */
116 nel |= 1; /* make odd */
117 while (!isprime(nel))
118 nel += 2;
119
120 htab->size = nel;
121 htab->filled = 0;
122
123 /* allocate memory and zero out */
124 htab->table = (struct env_entry_node *)calloc(htab->size + 1,
125 sizeof(struct env_entry_node));
126 if (htab->table == NULL)
127 return 0;
128
129 /* everything went alright */
130 return 1;
131 }
132
133
134 /*
135 * hdestroy()
136 */
137
138 /*
139 * After using the hash table it has to be destroyed. The used memory can
140 * be freed and the local static variable can be marked as not used.
141 */
142
hdestroy_r(struct hsearch_data * htab)143 void hdestroy_r(struct hsearch_data *htab)
144 {
145 int i;
146
147 /* Test for correct arguments. */
148 if (htab == NULL) {
149 __set_errno(EINVAL);
150 return;
151 }
152
153 /* free used memory */
154 for (i = 1; i <= htab->size; ++i) {
155 if (htab->table[i].used > 0) {
156 struct env_entry *ep = &htab->table[i].entry;
157
158 free((void *)ep->key);
159 free(ep->data);
160 }
161 }
162 free(htab->table);
163
164 /* the sign for an existing table is an value != NULL in htable */
165 htab->table = NULL;
166 }
167
168 /*
169 * hsearch()
170 */
171
172 /*
173 * This is the search function. It uses double hashing with open addressing.
174 * The argument item.key has to be a pointer to an zero terminated, most
175 * probably strings of chars. The function for generating a number of the
176 * strings is simple but fast. It can be replaced by a more complex function
177 * like ajw (see [Aho,Sethi,Ullman]) if the needs are shown.
178 *
179 * We use an trick to speed up the lookup. The table is created by hcreate
180 * with one more element available. This enables us to use the index zero
181 * special. This index will never be used because we store the first hash
182 * index in the field used where zero means not used. Every other value
183 * means used. The used field can be used as a first fast comparison for
184 * equality of the stored and the parameter value. This helps to prevent
185 * unnecessary expensive calls of strcmp.
186 *
187 * This implementation differs from the standard library version of
188 * this function in a number of ways:
189 *
190 * - While the standard version does not make any assumptions about
191 * the type of the stored data objects at all, this implementation
192 * works with NUL terminated strings only.
193 * - Instead of storing just pointers to the original objects, we
194 * create local copies so the caller does not need to care about the
195 * data any more.
196 * - The standard implementation does not provide a way to update an
197 * existing entry. This version will create a new entry or update an
198 * existing one when both "action == ENV_ENTER" and "item.data != NULL".
199 * - Instead of returning 1 on success, we return the index into the
200 * internal hash table, which is also guaranteed to be positive.
201 * This allows us direct access to the found hash table slot for
202 * example for functions like hdelete().
203 */
204
hmatch_r(const char * match,int last_idx,struct env_entry ** retval,struct hsearch_data * htab)205 int hmatch_r(const char *match, int last_idx, struct env_entry **retval,
206 struct hsearch_data *htab)
207 {
208 unsigned int idx;
209 size_t key_len = strlen(match);
210
211 for (idx = last_idx + 1; idx < htab->size; ++idx) {
212 if (htab->table[idx].used <= 0)
213 continue;
214 if (!strncmp(match, htab->table[idx].entry.key, key_len)) {
215 *retval = &htab->table[idx].entry;
216 return idx;
217 }
218 }
219
220 __set_errno(ESRCH);
221 *retval = NULL;
222 return 0;
223 }
224
225 /*
226 * Compare an existing entry with the desired key, and overwrite if the action
227 * is ENV_ENTER. This is simply a helper function for hsearch_r().
228 */
_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)229 static inline int _compare_and_overwrite_entry(struct env_entry item,
230 enum env_action action, struct env_entry **retval,
231 struct hsearch_data *htab, int flag, unsigned int hval,
232 unsigned int idx)
233 {
234 if (htab->table[idx].used == hval
235 && strcmp(item.key, htab->table[idx].entry.key) == 0) {
236 /* Overwrite existing value? */
237 if (action == ENV_ENTER && item.data) {
238 /* check for permission */
239 if (htab->change_ok != NULL && htab->change_ok(
240 &htab->table[idx].entry, item.data,
241 env_op_overwrite, flag)) {
242 debug("change_ok() rejected setting variable "
243 "%s, skipping it!\n", item.key);
244 __set_errno(EPERM);
245 *retval = NULL;
246 return 0;
247 }
248
249 /* If there is a callback, call it */
250 if (htab->table[idx].entry.callback &&
251 htab->table[idx].entry.callback(item.key,
252 item.data, env_op_overwrite, flag)) {
253 debug("callback() rejected setting variable "
254 "%s, skipping it!\n", item.key);
255 __set_errno(EINVAL);
256 *retval = NULL;
257 return 0;
258 }
259
260 free(htab->table[idx].entry.data);
261 htab->table[idx].entry.data = strdup(item.data);
262 if (!htab->table[idx].entry.data) {
263 __set_errno(ENOMEM);
264 *retval = NULL;
265 return 0;
266 }
267 }
268 /* return found entry */
269 *retval = &htab->table[idx].entry;
270 return idx;
271 }
272 /* keep searching */
273 return -1;
274 }
275
hsearch_r(struct env_entry item,enum env_action action,struct env_entry ** retval,struct hsearch_data * htab,int flag)276 int hsearch_r(struct env_entry item, enum env_action action,
277 struct env_entry **retval, struct hsearch_data *htab, int flag)
278 {
279 unsigned int hval;
280 unsigned int count;
281 unsigned int len = strlen(item.key);
282 unsigned int idx;
283 unsigned int first_deleted = 0;
284 int ret;
285
286 /* Compute an value for the given string. Perhaps use a better method. */
287 hval = len;
288 count = len;
289 while (count-- > 0) {
290 hval <<= 4;
291 hval += item.key[count];
292 }
293
294 /*
295 * First hash function:
296 * simply take the modul but prevent zero.
297 */
298 hval %= htab->size;
299 if (hval == 0)
300 ++hval;
301
302 /* The first index tried. */
303 idx = hval;
304
305 if (htab->table[idx].used) {
306 /*
307 * Further action might be required according to the
308 * action value.
309 */
310 unsigned hval2;
311
312 if (htab->table[idx].used == USED_DELETED
313 && !first_deleted)
314 first_deleted = idx;
315
316 ret = _compare_and_overwrite_entry(item, action, retval, htab,
317 flag, hval, idx);
318 if (ret != -1)
319 return ret;
320
321 /*
322 * Second hash function:
323 * as suggested in [Knuth]
324 */
325 hval2 = 1 + hval % (htab->size - 2);
326
327 do {
328 /*
329 * Because SIZE is prime this guarantees to
330 * step through all available indices.
331 */
332 if (idx <= hval2)
333 idx = htab->size + idx - hval2;
334 else
335 idx -= hval2;
336
337 /*
338 * If we visited all entries leave the loop
339 * unsuccessfully.
340 */
341 if (idx == hval)
342 break;
343
344 if (htab->table[idx].used == USED_DELETED
345 && !first_deleted)
346 first_deleted = idx;
347
348 /* If entry is found use it. */
349 ret = _compare_and_overwrite_entry(item, action, retval,
350 htab, flag, hval, idx);
351 if (ret != -1)
352 return ret;
353 }
354 while (htab->table[idx].used != USED_FREE);
355 }
356
357 /* An empty bucket has been found. */
358 if (action == ENV_ENTER) {
359 /*
360 * If table is full and another entry should be
361 * entered return with error.
362 */
363 if (htab->filled == htab->size) {
364 __set_errno(ENOMEM);
365 *retval = NULL;
366 return 0;
367 }
368
369 /*
370 * Create new entry;
371 * create copies of item.key and item.data
372 */
373 if (first_deleted)
374 idx = first_deleted;
375
376 htab->table[idx].used = hval;
377 htab->table[idx].entry.key = strdup(item.key);
378 htab->table[idx].entry.data = strdup(item.data);
379 if (!htab->table[idx].entry.key ||
380 !htab->table[idx].entry.data) {
381 __set_errno(ENOMEM);
382 *retval = NULL;
383 return 0;
384 }
385
386 ++htab->filled;
387
388 /* This is a new entry, so look up a possible callback */
389 env_callback_init(&htab->table[idx].entry);
390 /* Also look for flags */
391 env_flags_init(&htab->table[idx].entry);
392
393 /* check for permission */
394 if (htab->change_ok != NULL && htab->change_ok(
395 &htab->table[idx].entry, item.data, env_op_create, flag)) {
396 debug("change_ok() rejected setting variable "
397 "%s, skipping it!\n", item.key);
398 _hdelete(item.key, htab, &htab->table[idx].entry, idx);
399 __set_errno(EPERM);
400 *retval = NULL;
401 return 0;
402 }
403
404 /* If there is a callback, call it */
405 if (htab->table[idx].entry.callback &&
406 htab->table[idx].entry.callback(item.key, item.data,
407 env_op_create, flag)) {
408 debug("callback() rejected setting variable "
409 "%s, skipping it!\n", item.key);
410 _hdelete(item.key, htab, &htab->table[idx].entry, idx);
411 __set_errno(EINVAL);
412 *retval = NULL;
413 return 0;
414 }
415
416 /* return new entry */
417 *retval = &htab->table[idx].entry;
418 return 1;
419 }
420
421 __set_errno(ESRCH);
422 *retval = NULL;
423 return 0;
424 }
425
426
427 /*
428 * hdelete()
429 */
430
431 /*
432 * The standard implementation of hsearch(3) does not provide any way
433 * to delete any entries from the hash table. We extend the code to
434 * do that.
435 */
436
_hdelete(const char * key,struct hsearch_data * htab,struct env_entry * ep,int idx)437 static void _hdelete(const char *key, struct hsearch_data *htab,
438 struct env_entry *ep, int idx)
439 {
440 /* free used entry */
441 debug("hdelete: DELETING key \"%s\"\n", key);
442 free((void *)ep->key);
443 free(ep->data);
444 ep->callback = NULL;
445 ep->flags = 0;
446 htab->table[idx].used = USED_DELETED;
447
448 --htab->filled;
449 }
450
hdelete_r(const char * key,struct hsearch_data * htab,int flag)451 int hdelete_r(const char *key, struct hsearch_data *htab, int flag)
452 {
453 struct env_entry e, *ep;
454 int idx;
455
456 debug("hdelete: DELETE key \"%s\"\n", key);
457
458 e.key = (char *)key;
459
460 idx = hsearch_r(e, ENV_FIND, &ep, htab, 0);
461 if (idx == 0) {
462 __set_errno(ESRCH);
463 return 0; /* not found */
464 }
465
466 /* Check for permission */
467 if (htab->change_ok != NULL &&
468 htab->change_ok(ep, NULL, env_op_delete, flag)) {
469 debug("change_ok() rejected deleting variable "
470 "%s, skipping it!\n", key);
471 __set_errno(EPERM);
472 return 0;
473 }
474
475 /* If there is a callback, call it */
476 if (htab->table[idx].entry.callback &&
477 htab->table[idx].entry.callback(key, NULL, env_op_delete, flag)) {
478 debug("callback() rejected deleting variable "
479 "%s, skipping it!\n", key);
480 __set_errno(EINVAL);
481 return 0;
482 }
483
484 _hdelete(key, htab, ep, idx);
485
486 return 1;
487 }
488
489 #if !(defined(CONFIG_SPL_BUILD) && !defined(CONFIG_SPL_SAVEENV))
490 /*
491 * hexport()
492 */
493
494 /*
495 * Export the data stored in the hash table in linearized form.
496 *
497 * Entries are exported as "name=value" strings, separated by an
498 * arbitrary (non-NUL, of course) separator character. This allows to
499 * use this function both when formatting the U-Boot environment for
500 * external storage (using '\0' as separator), but also when using it
501 * for the "printenv" command to print all variables, simply by using
502 * as '\n" as separator. This can also be used for new features like
503 * exporting the environment data as text file, including the option
504 * for later re-import.
505 *
506 * The entries in the result list will be sorted by ascending key
507 * values.
508 *
509 * If the separator character is different from NUL, then any
510 * separator characters and backslash characters in the values will
511 * be escaped by a preceding backslash in output. This is needed for
512 * example to enable multi-line values, especially when the output
513 * shall later be parsed (for example, for re-import).
514 *
515 * There are several options how the result buffer is handled:
516 *
517 * *resp size
518 * -----------
519 * NULL 0 A string of sufficient length will be allocated.
520 * NULL >0 A string of the size given will be
521 * allocated. An error will be returned if the size is
522 * not sufficient. Any unused bytes in the string will
523 * be '\0'-padded.
524 * !NULL 0 The user-supplied buffer will be used. No length
525 * checking will be performed, i. e. it is assumed that
526 * the buffer size will always be big enough. DANGEROUS.
527 * !NULL >0 The user-supplied buffer will be used. An error will
528 * be returned if the size is not sufficient. Any unused
529 * bytes in the string will be '\0'-padded.
530 */
531
cmpkey(const void * p1,const void * p2)532 static int cmpkey(const void *p1, const void *p2)
533 {
534 struct env_entry *e1 = *(struct env_entry **)p1;
535 struct env_entry *e2 = *(struct env_entry **)p2;
536
537 return (strcmp(e1->key, e2->key));
538 }
539
match_string(int flag,const char * str,const char * pat,void * priv)540 static int match_string(int flag, const char *str, const char *pat, void *priv)
541 {
542 switch (flag & H_MATCH_METHOD) {
543 case H_MATCH_IDENT:
544 if (strcmp(str, pat) == 0)
545 return 1;
546 break;
547 case H_MATCH_SUBSTR:
548 if (strstr(str, pat))
549 return 1;
550 break;
551 #ifdef CONFIG_REGEX
552 case H_MATCH_REGEX:
553 {
554 struct slre *slrep = (struct slre *)priv;
555
556 if (slre_match(slrep, str, strlen(str), NULL))
557 return 1;
558 }
559 break;
560 #endif
561 default:
562 printf("## ERROR: unsupported match method: 0x%02x\n",
563 flag & H_MATCH_METHOD);
564 break;
565 }
566 return 0;
567 }
568
match_entry(struct env_entry * ep,int flag,int argc,char * const argv[])569 static int match_entry(struct env_entry *ep, int flag, int argc,
570 char *const argv[])
571 {
572 int arg;
573 void *priv = NULL;
574
575 for (arg = 0; arg < argc; ++arg) {
576 #ifdef CONFIG_REGEX
577 struct slre slre;
578
579 if (slre_compile(&slre, argv[arg]) == 0) {
580 printf("Error compiling regex: %s\n", slre.err_str);
581 return 0;
582 }
583
584 priv = (void *)&slre;
585 #endif
586 if (flag & H_MATCH_KEY) {
587 if (match_string(flag, ep->key, argv[arg], priv))
588 return 1;
589 }
590 if (flag & H_MATCH_DATA) {
591 if (match_string(flag, ep->data, argv[arg], priv))
592 return 1;
593 }
594 }
595 return 0;
596 }
597
hexport_r(struct hsearch_data * htab,const char sep,int flag,char ** resp,size_t size,int argc,char * const argv[])598 ssize_t hexport_r(struct hsearch_data *htab, const char sep, int flag,
599 char **resp, size_t size,
600 int argc, char * const argv[])
601 {
602 struct env_entry *list[htab->size];
603 char *res, *p;
604 size_t totlen;
605 int i, n;
606
607 /* Test for correct arguments. */
608 if ((resp == NULL) || (htab == NULL)) {
609 __set_errno(EINVAL);
610 return (-1);
611 }
612
613 debug("EXPORT table = %p, htab.size = %d, htab.filled = %d, size = %lu\n",
614 htab, htab->size, htab->filled, (ulong)size);
615 /*
616 * Pass 1:
617 * search used entries,
618 * save addresses and compute total length
619 */
620 for (i = 1, n = 0, totlen = 0; i <= htab->size; ++i) {
621
622 if (htab->table[i].used > 0) {
623 struct env_entry *ep = &htab->table[i].entry;
624 int found = match_entry(ep, flag, argc, argv);
625
626 if ((argc > 0) && (found == 0))
627 continue;
628
629 if ((flag & H_HIDE_DOT) && ep->key[0] == '.')
630 continue;
631
632 list[n++] = ep;
633
634 totlen += strlen(ep->key);
635
636 if (sep == '\0') {
637 totlen += strlen(ep->data);
638 } else { /* check if escapes are needed */
639 char *s = ep->data;
640
641 while (*s) {
642 ++totlen;
643 /* add room for needed escape chars */
644 if ((*s == sep) || (*s == '\\'))
645 ++totlen;
646 ++s;
647 }
648 }
649 totlen += 2; /* for '=' and 'sep' char */
650 }
651 }
652
653 #ifdef DEBUG
654 /* Pass 1a: print unsorted list */
655 printf("Unsorted: n=%d\n", n);
656 for (i = 0; i < n; ++i) {
657 printf("\t%3d: %p ==> %-10s => %s\n",
658 i, list[i], list[i]->key, list[i]->data);
659 }
660 #endif
661
662 /* Sort list by keys */
663 qsort(list, n, sizeof(struct env_entry *), cmpkey);
664
665 /* Check if the user supplied buffer size is sufficient */
666 if (size) {
667 if (size < totlen + 1) { /* provided buffer too small */
668 printf("Env export buffer too small: %lu, but need %lu\n",
669 (ulong)size, (ulong)totlen + 1);
670 __set_errno(ENOMEM);
671 return (-1);
672 }
673 } else {
674 size = totlen + 1;
675 }
676
677 /* Check if the user provided a buffer */
678 if (*resp) {
679 /* yes; clear it */
680 res = *resp;
681 memset(res, '\0', size);
682 } else {
683 /* no, allocate and clear one */
684 *resp = res = calloc(1, size);
685 if (res == NULL) {
686 __set_errno(ENOMEM);
687 return (-1);
688 }
689 }
690 /*
691 * Pass 2:
692 * export sorted list of result data
693 */
694 for (i = 0, p = res; i < n; ++i) {
695 const char *s;
696
697 s = list[i]->key;
698 while (*s)
699 *p++ = *s++;
700 *p++ = '=';
701
702 s = list[i]->data;
703
704 while (*s) {
705 if ((*s == sep) || (*s == '\\'))
706 *p++ = '\\'; /* escape */
707 *p++ = *s++;
708 }
709 *p++ = sep;
710 }
711 *p = '\0'; /* terminate result */
712
713 return size;
714 }
715 #endif
716
717
718 /*
719 * himport()
720 */
721
722 /*
723 * Check whether variable 'name' is amongst vars[],
724 * and remove all instances by setting the pointer to NULL
725 */
drop_var_from_set(const char * name,int nvars,char * vars[])726 static int drop_var_from_set(const char *name, int nvars, char * vars[])
727 {
728 int i = 0;
729 int res = 0;
730
731 /* No variables specified means process all of them */
732 if (nvars == 0)
733 return 1;
734
735 for (i = 0; i < nvars; i++) {
736 if (vars[i] == NULL)
737 continue;
738 /* If we found it, delete all of them */
739 if (!strcmp(name, vars[i])) {
740 vars[i] = NULL;
741 res = 1;
742 }
743 }
744 if (!res)
745 debug("Skipping non-listed variable %s\n", name);
746
747 return res;
748 }
749
750 /*
751 * Import linearized data into hash table.
752 *
753 * This is the inverse function to hexport(): it takes a linear list
754 * of "name=value" pairs and creates hash table entries from it.
755 *
756 * Entries without "value", i. e. consisting of only "name" or
757 * "name=", will cause this entry to be deleted from the hash table.
758 *
759 * The "flag" argument can be used to control the behaviour: when the
760 * H_NOCLEAR bit is set, then an existing hash table will kept, i. e.
761 * new data will be added to an existing hash table; otherwise, if no
762 * vars are passed, old data will be discarded and a new hash table
763 * will be created. If vars are passed, passed vars that are not in
764 * the linear list of "name=value" pairs will be removed from the
765 * current hash table.
766 *
767 * The separator character for the "name=value" pairs can be selected,
768 * so we both support importing from externally stored environment
769 * data (separated by NUL characters) and from plain text files
770 * (entries separated by newline characters).
771 *
772 * To allow for nicely formatted text input, leading white space
773 * (sequences of SPACE and TAB chars) is ignored, and entries starting
774 * (after removal of any leading white space) with a '#' character are
775 * considered comments and ignored.
776 *
777 * [NOTE: this means that a variable name cannot start with a '#'
778 * character.]
779 *
780 * When using a non-NUL separator character, backslash is used as
781 * escape character in the value part, allowing for example for
782 * multi-line values.
783 *
784 * In theory, arbitrary separator characters can be used, but only
785 * '\0' and '\n' have really been tested.
786 */
787
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[])788 int himport_r(struct hsearch_data *htab,
789 const char *env, size_t size, const char sep, int flag,
790 int crlf_is_lf, int nvars, char * const vars[])
791 {
792 char *data, *sp, *dp, *name, *value;
793 char *localvars[nvars];
794 int i;
795
796 /* Test for correct arguments. */
797 if (htab == NULL) {
798 __set_errno(EINVAL);
799 return 0;
800 }
801
802 /* we allocate new space to make sure we can write to the array */
803 if ((data = malloc(size + 1)) == NULL) {
804 debug("himport_r: can't malloc %lu bytes\n", (ulong)size + 1);
805 __set_errno(ENOMEM);
806 return 0;
807 }
808 memcpy(data, env, size);
809 data[size] = '\0';
810 dp = data;
811
812 /* make a local copy of the list of variables */
813 if (nvars)
814 memcpy(localvars, vars, sizeof(vars[0]) * nvars);
815
816 if ((flag & H_NOCLEAR) == 0 && !nvars) {
817 /* Destroy old hash table if one exists */
818 debug("Destroy Hash Table: %p table = %p\n", htab,
819 htab->table);
820 if (htab->table)
821 hdestroy_r(htab);
822 }
823
824 /*
825 * Create new hash table (if needed). The computation of the hash
826 * table size is based on heuristics: in a sample of some 70+
827 * existing systems we found an average size of 39+ bytes per entry
828 * in the environment (for the whole key=value pair). Assuming a
829 * size of 8 per entry (= safety factor of ~5) should provide enough
830 * safety margin for any existing environment definitions and still
831 * allow for more than enough dynamic additions. Note that the
832 * "size" argument is supposed to give the maximum environment size
833 * (CONFIG_ENV_SIZE). This heuristics will result in
834 * unreasonably large numbers (and thus memory footprint) for
835 * big flash environments (>8,000 entries for 64 KB
836 * environment size), so we clip it to a reasonable value.
837 * On the other hand we need to add some more entries for free
838 * space when importing very small buffers. Both boundaries can
839 * be overwritten in the board config file if needed.
840 */
841
842 if (!htab->table) {
843 int nent = CONFIG_ENV_MIN_ENTRIES + size / 8;
844
845 if (nent > CONFIG_ENV_MAX_ENTRIES)
846 nent = CONFIG_ENV_MAX_ENTRIES;
847
848 debug("Create Hash Table: N=%d\n", nent);
849
850 if (hcreate_r(nent, htab) == 0) {
851 free(data);
852 return 0;
853 }
854 }
855
856 if (!size) {
857 free(data);
858 return 1; /* everything OK */
859 }
860 if(crlf_is_lf) {
861 /* Remove Carriage Returns in front of Line Feeds */
862 unsigned ignored_crs = 0;
863 for(;dp < data + size && *dp; ++dp) {
864 if(*dp == '\r' &&
865 dp < data + size - 1 && *(dp+1) == '\n')
866 ++ignored_crs;
867 else
868 *(dp-ignored_crs) = *dp;
869 }
870 size -= ignored_crs;
871 dp = data;
872 }
873 /* Parse environment; allow for '\0' and 'sep' as separators */
874 do {
875 struct env_entry e, *rv;
876
877 /* skip leading white space */
878 while (isblank(*dp))
879 ++dp;
880
881 /* skip comment lines */
882 if (*dp == '#') {
883 while (*dp && (*dp != sep))
884 ++dp;
885 ++dp;
886 continue;
887 }
888
889 /* parse name */
890 for (name = dp; *dp != '=' && *dp && *dp != sep; ++dp)
891 ;
892
893 /* deal with "name" and "name=" entries (delete var) */
894 if (*dp == '\0' || *(dp + 1) == '\0' ||
895 *dp == sep || *(dp + 1) == sep) {
896 if (*dp == '=')
897 *dp++ = '\0';
898 *dp++ = '\0'; /* terminate name */
899
900 debug("DELETE CANDIDATE: \"%s\"\n", name);
901 if (!drop_var_from_set(name, nvars, localvars))
902 continue;
903
904 if (hdelete_r(name, htab, flag) == 0)
905 debug("DELETE ERROR ##############################\n");
906
907 continue;
908 }
909 *dp++ = '\0'; /* terminate name */
910
911 /* parse value; deal with escapes */
912 for (value = sp = dp; *dp && (*dp != sep); ++dp) {
913 if ((*dp == '\\') && *(dp + 1))
914 ++dp;
915 *sp++ = *dp;
916 }
917 *sp++ = '\0'; /* terminate value */
918 ++dp;
919
920 if (*name == 0) {
921 debug("INSERT: unable to use an empty key\n");
922 __set_errno(EINVAL);
923 free(data);
924 return 0;
925 }
926
927 /* Skip variables which are not supposed to be processed */
928 if (!drop_var_from_set(name, nvars, localvars))
929 continue;
930
931 /* enter into hash table */
932 e.key = name;
933 e.data = value;
934
935 hsearch_r(e, ENV_ENTER, &rv, htab, flag);
936 if (rv == NULL)
937 printf("himport_r: can't insert \"%s=%s\" into hash table\n",
938 name, value);
939
940 debug("INSERT: table %p, filled %d/%d rv %p ==> name=\"%s\" value=\"%s\"\n",
941 htab, htab->filled, htab->size,
942 rv, name, value);
943 } while ((dp < data + size) && *dp); /* size check needed for text */
944 /* without '\0' termination */
945 debug("INSERT: free(data = %p)\n", data);
946 free(data);
947
948 if (flag & H_NOCLEAR)
949 goto end;
950
951 /* process variables which were not considered */
952 for (i = 0; i < nvars; i++) {
953 if (localvars[i] == NULL)
954 continue;
955 /*
956 * All variables which were not deleted from the variable list
957 * were not present in the imported env
958 * This could mean two things:
959 * a) if the variable was present in current env, we delete it
960 * b) if the variable was not present in current env, we notify
961 * it might be a typo
962 */
963 if (hdelete_r(localvars[i], htab, flag) == 0)
964 printf("WARNING: '%s' neither in running nor in imported env!\n", localvars[i]);
965 else
966 printf("WARNING: '%s' not in imported env, deleting it!\n", localvars[i]);
967 }
968
969 end:
970 debug("INSERT: done\n");
971 return 1; /* everything OK */
972 }
973
974 /*
975 * hwalk_r()
976 */
977
978 /*
979 * Walk all of the entries in the hash, calling the callback for each one.
980 * this allows some generic operation to be performed on each element.
981 */
hwalk_r(struct hsearch_data * htab,int (* callback)(struct env_entry * entry))982 int hwalk_r(struct hsearch_data *htab, int (*callback)(struct env_entry *entry))
983 {
984 int i;
985 int retval;
986
987 for (i = 1; i <= htab->size; ++i) {
988 if (htab->table[i].used > 0) {
989 retval = callback(&htab->table[i].entry);
990 if (retval)
991 return retval;
992 }
993 }
994
995 return 0;
996 }
997