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a6826fbc WD |
1 | /* |
2 | * This implementation is based on code from uClibc-0.9.30.3 but was | |
3 | * modified and extended for use within U-Boot. | |
4 | * | |
5 | * Copyright (C) 2010 Wolfgang Denk <wd@denx.de> | |
6 | * | |
7 | * Original license header: | |
8 | * | |
9 | * Copyright (C) 1993, 1995, 1996, 1997, 2002 Free Software Foundation, Inc. | |
10 | * This file is part of the GNU C Library. | |
11 | * Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1993. | |
12 | * | |
13 | * The GNU C Library is free software; you can redistribute it and/or | |
14 | * modify it under the terms of the GNU Lesser General Public | |
15 | * License as published by the Free Software Foundation; either | |
16 | * version 2.1 of the License, or (at your option) any later version. | |
17 | * | |
18 | * The GNU C Library is distributed in the hope that it will be useful, | |
19 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
20 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
21 | * Lesser General Public License for more details. | |
22 | * | |
23 | * You should have received a copy of the GNU Lesser General Public | |
24 | * License along with the GNU C Library; if not, write to the Free | |
25 | * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA | |
26 | * 02111-1307 USA. | |
27 | */ | |
28 | ||
29 | #include <errno.h> | |
30 | #include <malloc.h> | |
31 | ||
32 | #ifdef USE_HOSTCC /* HOST build */ | |
33 | # include <string.h> | |
34 | # include <assert.h> | |
4d91a6ec | 35 | # include <ctype.h> |
a6826fbc WD |
36 | |
37 | # ifndef debug | |
38 | # ifdef DEBUG | |
39 | # define debug(fmt,args...) printf(fmt ,##args) | |
40 | # else | |
41 | # define debug(fmt,args...) | |
42 | # endif | |
43 | # endif | |
44 | #else /* U-Boot build */ | |
45 | # include <common.h> | |
46 | # include <linux/string.h> | |
4d91a6ec | 47 | # include <linux/ctype.h> |
a6826fbc WD |
48 | #endif |
49 | ||
fc5fc76b AB |
50 | #ifndef CONFIG_ENV_MIN_ENTRIES /* minimum number of entries */ |
51 | #define CONFIG_ENV_MIN_ENTRIES 64 | |
52 | #endif | |
ea882baf WD |
53 | #ifndef CONFIG_ENV_MAX_ENTRIES /* maximum number of entries */ |
54 | #define CONFIG_ENV_MAX_ENTRIES 512 | |
55 | #endif | |
56 | ||
a6826fbc WD |
57 | #include "search.h" |
58 | ||
59 | /* | |
60 | * [Aho,Sethi,Ullman] Compilers: Principles, Techniques and Tools, 1986 | |
071bc923 | 61 | * [Knuth] The Art of Computer Programming, part 3 (6.4) |
a6826fbc WD |
62 | */ |
63 | ||
a6826fbc WD |
64 | /* |
65 | * The reentrant version has no static variables to maintain the state. | |
66 | * Instead the interface of all functions is extended to take an argument | |
67 | * which describes the current status. | |
68 | */ | |
69 | typedef struct _ENTRY { | |
c81c1222 | 70 | int used; |
a6826fbc WD |
71 | ENTRY entry; |
72 | } _ENTRY; | |
73 | ||
74 | ||
75 | /* | |
76 | * hcreate() | |
77 | */ | |
78 | ||
79 | /* | |
80 | * For the used double hash method the table size has to be a prime. To | |
81 | * correct the user given table size we need a prime test. This trivial | |
82 | * algorithm is adequate because | |
83 | * a) the code is (most probably) called a few times per program run and | |
84 | * b) the number is small because the table must fit in the core | |
85 | * */ | |
86 | static int isprime(unsigned int number) | |
87 | { | |
88 | /* no even number will be passed */ | |
89 | unsigned int div = 3; | |
90 | ||
91 | while (div * div < number && number % div != 0) | |
92 | div += 2; | |
93 | ||
94 | return number % div != 0; | |
95 | } | |
96 | ||
a6826fbc WD |
97 | /* |
98 | * Before using the hash table we must allocate memory for it. | |
99 | * Test for an existing table are done. We allocate one element | |
100 | * more as the found prime number says. This is done for more effective | |
101 | * indexing as explained in the comment for the hsearch function. | |
102 | * The contents of the table is zeroed, especially the field used | |
103 | * becomes zero. | |
104 | */ | |
2eb1573f | 105 | |
a6826fbc WD |
106 | int hcreate_r(size_t nel, struct hsearch_data *htab) |
107 | { | |
108 | /* Test for correct arguments. */ | |
109 | if (htab == NULL) { | |
110 | __set_errno(EINVAL); | |
111 | return 0; | |
112 | } | |
113 | ||
114 | /* There is still another table active. Return with error. */ | |
115 | if (htab->table != NULL) | |
116 | return 0; | |
117 | ||
118 | /* Change nel to the first prime number not smaller as nel. */ | |
119 | nel |= 1; /* make odd */ | |
120 | while (!isprime(nel)) | |
121 | nel += 2; | |
122 | ||
123 | htab->size = nel; | |
124 | htab->filled = 0; | |
125 | ||
126 | /* allocate memory and zero out */ | |
127 | htab->table = (_ENTRY *) calloc(htab->size + 1, sizeof(_ENTRY)); | |
128 | if (htab->table == NULL) | |
129 | return 0; | |
130 | ||
131 | /* everything went alright */ | |
132 | return 1; | |
133 | } | |
134 | ||
135 | ||
136 | /* | |
137 | * hdestroy() | |
138 | */ | |
a6826fbc WD |
139 | |
140 | /* | |
141 | * After using the hash table it has to be destroyed. The used memory can | |
142 | * be freed and the local static variable can be marked as not used. | |
143 | */ | |
2eb1573f | 144 | |
c4e0057f | 145 | void hdestroy_r(struct hsearch_data *htab) |
a6826fbc WD |
146 | { |
147 | int i; | |
148 | ||
149 | /* Test for correct arguments. */ | |
150 | if (htab == NULL) { | |
151 | __set_errno(EINVAL); | |
152 | return; | |
153 | } | |
154 | ||
155 | /* free used memory */ | |
156 | for (i = 1; i <= htab->size; ++i) { | |
c81c1222 | 157 | if (htab->table[i].used > 0) { |
a6826fbc | 158 | ENTRY *ep = &htab->table[i].entry; |
c4e0057f | 159 | |
84b5e802 | 160 | free((void *)ep->key); |
a6826fbc WD |
161 | free(ep->data); |
162 | } | |
163 | } | |
164 | free(htab->table); | |
165 | ||
166 | /* the sign for an existing table is an value != NULL in htable */ | |
167 | htab->table = NULL; | |
168 | } | |
169 | ||
170 | /* | |
171 | * hsearch() | |
172 | */ | |
173 | ||
174 | /* | |
175 | * This is the search function. It uses double hashing with open addressing. | |
176 | * The argument item.key has to be a pointer to an zero terminated, most | |
177 | * probably strings of chars. The function for generating a number of the | |
178 | * strings is simple but fast. It can be replaced by a more complex function | |
179 | * like ajw (see [Aho,Sethi,Ullman]) if the needs are shown. | |
180 | * | |
181 | * We use an trick to speed up the lookup. The table is created by hcreate | |
182 | * with one more element available. This enables us to use the index zero | |
183 | * special. This index will never be used because we store the first hash | |
184 | * index in the field used where zero means not used. Every other value | |
185 | * means used. The used field can be used as a first fast comparison for | |
186 | * equality of the stored and the parameter value. This helps to prevent | |
187 | * unnecessary expensive calls of strcmp. | |
188 | * | |
189 | * This implementation differs from the standard library version of | |
190 | * this function in a number of ways: | |
191 | * | |
192 | * - While the standard version does not make any assumptions about | |
193 | * the type of the stored data objects at all, this implementation | |
194 | * works with NUL terminated strings only. | |
195 | * - Instead of storing just pointers to the original objects, we | |
196 | * create local copies so the caller does not need to care about the | |
197 | * data any more. | |
198 | * - The standard implementation does not provide a way to update an | |
199 | * existing entry. This version will create a new entry or update an | |
200 | * existing one when both "action == ENTER" and "item.data != NULL". | |
201 | * - Instead of returning 1 on success, we return the index into the | |
202 | * internal hash table, which is also guaranteed to be positive. | |
203 | * This allows us direct access to the found hash table slot for | |
204 | * example for functions like hdelete(). | |
205 | */ | |
206 | ||
a000b795 KP |
207 | /* |
208 | * hstrstr_r - return index to entry whose key and/or data contains match | |
209 | */ | |
210 | int hstrstr_r(const char *match, int last_idx, ENTRY ** retval, | |
211 | struct hsearch_data *htab) | |
212 | { | |
213 | unsigned int idx; | |
214 | ||
215 | for (idx = last_idx + 1; idx < htab->size; ++idx) { | |
216 | if (htab->table[idx].used <= 0) | |
217 | continue; | |
218 | if (strstr(htab->table[idx].entry.key, match) || | |
219 | strstr(htab->table[idx].entry.data, match)) { | |
220 | *retval = &htab->table[idx].entry; | |
221 | return idx; | |
222 | } | |
223 | } | |
224 | ||
225 | __set_errno(ESRCH); | |
226 | *retval = NULL; | |
227 | return 0; | |
228 | } | |
229 | ||
560d424b MF |
230 | int hmatch_r(const char *match, int last_idx, ENTRY ** retval, |
231 | struct hsearch_data *htab) | |
232 | { | |
233 | unsigned int idx; | |
234 | size_t key_len = strlen(match); | |
235 | ||
236 | for (idx = last_idx + 1; idx < htab->size; ++idx) { | |
af4d9074 | 237 | if (htab->table[idx].used <= 0) |
560d424b MF |
238 | continue; |
239 | if (!strncmp(match, htab->table[idx].entry.key, key_len)) { | |
240 | *retval = &htab->table[idx].entry; | |
241 | return idx; | |
242 | } | |
243 | } | |
244 | ||
245 | __set_errno(ESRCH); | |
246 | *retval = NULL; | |
247 | return 0; | |
248 | } | |
249 | ||
3d3b52f2 JH |
250 | /* |
251 | * Compare an existing entry with the desired key, and overwrite if the action | |
252 | * is ENTER. This is simply a helper function for hsearch_r(). | |
253 | */ | |
254 | static inline int _compare_and_overwrite_entry(ENTRY item, ACTION action, | |
255 | ENTRY **retval, struct hsearch_data *htab, int flag, | |
256 | unsigned int hval, unsigned int idx) | |
257 | { | |
258 | if (htab->table[idx].used == hval | |
259 | && strcmp(item.key, htab->table[idx].entry.key) == 0) { | |
260 | /* Overwrite existing value? */ | |
261 | if ((action == ENTER) && (item.data != NULL)) { | |
262 | free(htab->table[idx].entry.data); | |
263 | htab->table[idx].entry.data = strdup(item.data); | |
264 | if (!htab->table[idx].entry.data) { | |
265 | __set_errno(ENOMEM); | |
266 | *retval = NULL; | |
267 | return 0; | |
268 | } | |
269 | } | |
270 | /* return found entry */ | |
271 | *retval = &htab->table[idx].entry; | |
272 | return idx; | |
273 | } | |
274 | /* keep searching */ | |
275 | return -1; | |
276 | } | |
277 | ||
a6826fbc | 278 | int hsearch_r(ENTRY item, ACTION action, ENTRY ** retval, |
c4e0057f | 279 | struct hsearch_data *htab, int flag) |
a6826fbc WD |
280 | { |
281 | unsigned int hval; | |
282 | unsigned int count; | |
283 | unsigned int len = strlen(item.key); | |
284 | unsigned int idx; | |
c81c1222 | 285 | unsigned int first_deleted = 0; |
3d3b52f2 | 286 | int ret; |
a6826fbc WD |
287 | |
288 | /* Compute an value for the given string. Perhaps use a better method. */ | |
289 | hval = len; | |
290 | count = len; | |
291 | while (count-- > 0) { | |
292 | hval <<= 4; | |
293 | hval += item.key[count]; | |
294 | } | |
295 | ||
296 | /* | |
297 | * First hash function: | |
298 | * simply take the modul but prevent zero. | |
299 | */ | |
300 | hval %= htab->size; | |
301 | if (hval == 0) | |
302 | ++hval; | |
303 | ||
304 | /* The first index tried. */ | |
305 | idx = hval; | |
306 | ||
307 | if (htab->table[idx].used) { | |
308 | /* | |
071bc923 | 309 | * Further action might be required according to the |
a6826fbc WD |
310 | * action value. |
311 | */ | |
312 | unsigned hval2; | |
313 | ||
c81c1222 PB |
314 | if (htab->table[idx].used == -1 |
315 | && !first_deleted) | |
316 | first_deleted = idx; | |
317 | ||
3d3b52f2 JH |
318 | ret = _compare_and_overwrite_entry(item, action, retval, htab, |
319 | flag, hval, idx); | |
320 | if (ret != -1) | |
321 | return ret; | |
a6826fbc WD |
322 | |
323 | /* | |
324 | * Second hash function: | |
325 | * as suggested in [Knuth] | |
326 | */ | |
327 | hval2 = 1 + hval % (htab->size - 2); | |
328 | ||
329 | do { | |
330 | /* | |
071bc923 WD |
331 | * Because SIZE is prime this guarantees to |
332 | * step through all available indices. | |
a6826fbc WD |
333 | */ |
334 | if (idx <= hval2) | |
335 | idx = htab->size + idx - hval2; | |
336 | else | |
337 | idx -= hval2; | |
338 | ||
339 | /* | |
340 | * If we visited all entries leave the loop | |
341 | * unsuccessfully. | |
342 | */ | |
343 | if (idx == hval) | |
344 | break; | |
345 | ||
346 | /* If entry is found use it. */ | |
3d3b52f2 JH |
347 | ret = _compare_and_overwrite_entry(item, action, retval, |
348 | htab, flag, hval, idx); | |
349 | if (ret != -1) | |
350 | return ret; | |
a6826fbc WD |
351 | } |
352 | while (htab->table[idx].used); | |
353 | } | |
354 | ||
355 | /* An empty bucket has been found. */ | |
356 | if (action == ENTER) { | |
357 | /* | |
071bc923 WD |
358 | * If table is full and another entry should be |
359 | * entered return with error. | |
a6826fbc WD |
360 | */ |
361 | if (htab->filled == htab->size) { | |
362 | __set_errno(ENOMEM); | |
363 | *retval = NULL; | |
364 | return 0; | |
365 | } | |
366 | ||
367 | /* | |
368 | * Create new entry; | |
369 | * create copies of item.key and item.data | |
370 | */ | |
c81c1222 PB |
371 | if (first_deleted) |
372 | idx = first_deleted; | |
373 | ||
a6826fbc WD |
374 | htab->table[idx].used = hval; |
375 | htab->table[idx].entry.key = strdup(item.key); | |
376 | htab->table[idx].entry.data = strdup(item.data); | |
377 | if (!htab->table[idx].entry.key || | |
378 | !htab->table[idx].entry.data) { | |
379 | __set_errno(ENOMEM); | |
380 | *retval = NULL; | |
381 | return 0; | |
382 | } | |
383 | ||
384 | ++htab->filled; | |
385 | ||
386 | /* return new entry */ | |
387 | *retval = &htab->table[idx].entry; | |
388 | return 1; | |
389 | } | |
390 | ||
391 | __set_errno(ESRCH); | |
392 | *retval = NULL; | |
393 | return 0; | |
394 | } | |
395 | ||
396 | ||
397 | /* | |
398 | * hdelete() | |
399 | */ | |
400 | ||
401 | /* | |
402 | * The standard implementation of hsearch(3) does not provide any way | |
403 | * to delete any entries from the hash table. We extend the code to | |
404 | * do that. | |
405 | */ | |
406 | ||
c4e0057f | 407 | int hdelete_r(const char *key, struct hsearch_data *htab, int flag) |
a6826fbc WD |
408 | { |
409 | ENTRY e, *ep; | |
410 | int idx; | |
411 | ||
412 | debug("hdelete: DELETE key \"%s\"\n", key); | |
413 | ||
414 | e.key = (char *)key; | |
415 | ||
c4e0057f JH |
416 | idx = hsearch_r(e, FIND, &ep, htab, 0); |
417 | if (idx == 0) { | |
a6826fbc WD |
418 | __set_errno(ESRCH); |
419 | return 0; /* not found */ | |
420 | } | |
421 | ||
c4e0057f JH |
422 | /* Check for permission */ |
423 | if (htab->apply != NULL && | |
424 | htab->apply(ep->key, ep->data, NULL, flag)) { | |
425 | __set_errno(EPERM); | |
426 | return 0; | |
427 | } | |
428 | ||
a6826fbc WD |
429 | /* free used ENTRY */ |
430 | debug("hdelete: DELETING key \"%s\"\n", key); | |
84b5e802 | 431 | free((void *)ep->key); |
a6826fbc | 432 | free(ep->data); |
c81c1222 | 433 | htab->table[idx].used = -1; |
a6826fbc WD |
434 | |
435 | --htab->filled; | |
436 | ||
437 | return 1; | |
438 | } | |
439 | ||
440 | /* | |
441 | * hexport() | |
442 | */ | |
443 | ||
7ac2fe2d | 444 | #ifndef CONFIG_SPL_BUILD |
a6826fbc WD |
445 | /* |
446 | * Export the data stored in the hash table in linearized form. | |
447 | * | |
448 | * Entries are exported as "name=value" strings, separated by an | |
449 | * arbitrary (non-NUL, of course) separator character. This allows to | |
450 | * use this function both when formatting the U-Boot environment for | |
451 | * external storage (using '\0' as separator), but also when using it | |
452 | * for the "printenv" command to print all variables, simply by using | |
453 | * as '\n" as separator. This can also be used for new features like | |
454 | * exporting the environment data as text file, including the option | |
455 | * for later re-import. | |
456 | * | |
457 | * The entries in the result list will be sorted by ascending key | |
458 | * values. | |
459 | * | |
460 | * If the separator character is different from NUL, then any | |
461 | * separator characters and backslash characters in the values will | |
462 | * be escaped by a preceeding backslash in output. This is needed for | |
463 | * example to enable multi-line values, especially when the output | |
464 | * shall later be parsed (for example, for re-import). | |
465 | * | |
466 | * There are several options how the result buffer is handled: | |
467 | * | |
468 | * *resp size | |
469 | * ----------- | |
470 | * NULL 0 A string of sufficient length will be allocated. | |
471 | * NULL >0 A string of the size given will be | |
472 | * allocated. An error will be returned if the size is | |
473 | * not sufficient. Any unused bytes in the string will | |
474 | * be '\0'-padded. | |
475 | * !NULL 0 The user-supplied buffer will be used. No length | |
476 | * checking will be performed, i. e. it is assumed that | |
477 | * the buffer size will always be big enough. DANGEROUS. | |
478 | * !NULL >0 The user-supplied buffer will be used. An error will | |
479 | * be returned if the size is not sufficient. Any unused | |
480 | * bytes in the string will be '\0'-padded. | |
481 | */ | |
482 | ||
a6826fbc WD |
483 | static int cmpkey(const void *p1, const void *p2) |
484 | { | |
485 | ENTRY *e1 = *(ENTRY **) p1; | |
486 | ENTRY *e2 = *(ENTRY **) p2; | |
487 | ||
488 | return (strcmp(e1->key, e2->key)); | |
489 | } | |
490 | ||
491 | ssize_t hexport_r(struct hsearch_data *htab, const char sep, | |
37f2fe74 WD |
492 | char **resp, size_t size, |
493 | int argc, char * const argv[]) | |
a6826fbc WD |
494 | { |
495 | ENTRY *list[htab->size]; | |
496 | char *res, *p; | |
497 | size_t totlen; | |
498 | int i, n; | |
499 | ||
500 | /* Test for correct arguments. */ | |
501 | if ((resp == NULL) || (htab == NULL)) { | |
502 | __set_errno(EINVAL); | |
503 | return (-1); | |
504 | } | |
505 | ||
ff856286 SG |
506 | debug("EXPORT table = %p, htab.size = %d, htab.filled = %d, " |
507 | "size = %zu\n", htab, htab->size, htab->filled, size); | |
a6826fbc WD |
508 | /* |
509 | * Pass 1: | |
510 | * search used entries, | |
511 | * save addresses and compute total length | |
512 | */ | |
513 | for (i = 1, n = 0, totlen = 0; i <= htab->size; ++i) { | |
514 | ||
c81c1222 | 515 | if (htab->table[i].used > 0) { |
a6826fbc | 516 | ENTRY *ep = &htab->table[i].entry; |
37f2fe74 WD |
517 | int arg, found = 0; |
518 | ||
519 | for (arg = 0; arg < argc; ++arg) { | |
520 | if (strcmp(argv[arg], ep->key) == 0) { | |
521 | found = 1; | |
522 | break; | |
523 | } | |
524 | } | |
525 | if ((argc > 0) && (found == 0)) | |
526 | continue; | |
a6826fbc WD |
527 | |
528 | list[n++] = ep; | |
529 | ||
530 | totlen += strlen(ep->key) + 2; | |
531 | ||
532 | if (sep == '\0') { | |
533 | totlen += strlen(ep->data); | |
534 | } else { /* check if escapes are needed */ | |
535 | char *s = ep->data; | |
536 | ||
537 | while (*s) { | |
538 | ++totlen; | |
539 | /* add room for needed escape chars */ | |
540 | if ((*s == sep) || (*s == '\\')) | |
541 | ++totlen; | |
542 | ++s; | |
543 | } | |
544 | } | |
545 | totlen += 2; /* for '=' and 'sep' char */ | |
546 | } | |
547 | } | |
548 | ||
549 | #ifdef DEBUG | |
550 | /* Pass 1a: print unsorted list */ | |
551 | printf("Unsorted: n=%d\n", n); | |
552 | for (i = 0; i < n; ++i) { | |
553 | printf("\t%3d: %p ==> %-10s => %s\n", | |
554 | i, list[i], list[i]->key, list[i]->data); | |
555 | } | |
556 | #endif | |
557 | ||
558 | /* Sort list by keys */ | |
559 | qsort(list, n, sizeof(ENTRY *), cmpkey); | |
560 | ||
561 | /* Check if the user supplied buffer size is sufficient */ | |
562 | if (size) { | |
563 | if (size < totlen + 1) { /* provided buffer too small */ | |
ff856286 SG |
564 | printf("Env export buffer too small: %zu, " |
565 | "but need %zu\n", size, totlen + 1); | |
a6826fbc WD |
566 | __set_errno(ENOMEM); |
567 | return (-1); | |
568 | } | |
569 | } else { | |
570 | size = totlen + 1; | |
571 | } | |
572 | ||
573 | /* Check if the user provided a buffer */ | |
574 | if (*resp) { | |
575 | /* yes; clear it */ | |
576 | res = *resp; | |
577 | memset(res, '\0', size); | |
578 | } else { | |
579 | /* no, allocate and clear one */ | |
580 | *resp = res = calloc(1, size); | |
581 | if (res == NULL) { | |
582 | __set_errno(ENOMEM); | |
583 | return (-1); | |
584 | } | |
585 | } | |
586 | /* | |
587 | * Pass 2: | |
588 | * export sorted list of result data | |
589 | */ | |
590 | for (i = 0, p = res; i < n; ++i) { | |
84b5e802 | 591 | const char *s; |
a6826fbc WD |
592 | |
593 | s = list[i]->key; | |
594 | while (*s) | |
595 | *p++ = *s++; | |
596 | *p++ = '='; | |
597 | ||
598 | s = list[i]->data; | |
599 | ||
600 | while (*s) { | |
601 | if ((*s == sep) || (*s == '\\')) | |
602 | *p++ = '\\'; /* escape */ | |
603 | *p++ = *s++; | |
604 | } | |
605 | *p++ = sep; | |
606 | } | |
607 | *p = '\0'; /* terminate result */ | |
608 | ||
609 | return size; | |
610 | } | |
7ac2fe2d | 611 | #endif |
a6826fbc WD |
612 | |
613 | ||
614 | /* | |
615 | * himport() | |
616 | */ | |
617 | ||
d5370feb GF |
618 | /* |
619 | * Check whether variable 'name' is amongst vars[], | |
620 | * and remove all instances by setting the pointer to NULL | |
621 | */ | |
622 | static int drop_var_from_set(const char *name, int nvars, char * vars[]) | |
348b1f1c GF |
623 | { |
624 | int i = 0; | |
d5370feb | 625 | int res = 0; |
348b1f1c GF |
626 | |
627 | /* No variables specified means process all of them */ | |
628 | if (nvars == 0) | |
629 | return 1; | |
630 | ||
631 | for (i = 0; i < nvars; i++) { | |
d5370feb GF |
632 | if (vars[i] == NULL) |
633 | continue; | |
634 | /* If we found it, delete all of them */ | |
635 | if (!strcmp(name, vars[i])) { | |
636 | vars[i] = NULL; | |
637 | res = 1; | |
638 | } | |
348b1f1c | 639 | } |
d5370feb GF |
640 | if (!res) |
641 | debug("Skipping non-listed variable %s\n", name); | |
348b1f1c | 642 | |
d5370feb | 643 | return res; |
348b1f1c GF |
644 | } |
645 | ||
a6826fbc WD |
646 | /* |
647 | * Import linearized data into hash table. | |
648 | * | |
649 | * This is the inverse function to hexport(): it takes a linear list | |
650 | * of "name=value" pairs and creates hash table entries from it. | |
651 | * | |
652 | * Entries without "value", i. e. consisting of only "name" or | |
653 | * "name=", will cause this entry to be deleted from the hash table. | |
654 | * | |
655 | * The "flag" argument can be used to control the behaviour: when the | |
656 | * H_NOCLEAR bit is set, then an existing hash table will kept, i. e. | |
657 | * new data will be added to an existing hash table; otherwise, old | |
658 | * data will be discarded and a new hash table will be created. | |
659 | * | |
660 | * The separator character for the "name=value" pairs can be selected, | |
661 | * so we both support importing from externally stored environment | |
662 | * data (separated by NUL characters) and from plain text files | |
663 | * (entries separated by newline characters). | |
664 | * | |
665 | * To allow for nicely formatted text input, leading white space | |
666 | * (sequences of SPACE and TAB chars) is ignored, and entries starting | |
667 | * (after removal of any leading white space) with a '#' character are | |
668 | * considered comments and ignored. | |
669 | * | |
670 | * [NOTE: this means that a variable name cannot start with a '#' | |
671 | * character.] | |
672 | * | |
673 | * When using a non-NUL separator character, backslash is used as | |
674 | * escape character in the value part, allowing for example for | |
675 | * multi-line values. | |
676 | * | |
677 | * In theory, arbitrary separator characters can be used, but only | |
678 | * '\0' and '\n' have really been tested. | |
679 | */ | |
680 | ||
a6826fbc | 681 | int himport_r(struct hsearch_data *htab, |
348b1f1c | 682 | const char *env, size_t size, const char sep, int flag, |
c4e0057f | 683 | int nvars, char * const vars[]) |
a6826fbc WD |
684 | { |
685 | char *data, *sp, *dp, *name, *value; | |
d5370feb GF |
686 | char *localvars[nvars]; |
687 | int i; | |
a6826fbc WD |
688 | |
689 | /* Test for correct arguments. */ | |
690 | if (htab == NULL) { | |
691 | __set_errno(EINVAL); | |
692 | return 0; | |
693 | } | |
694 | ||
695 | /* we allocate new space to make sure we can write to the array */ | |
696 | if ((data = malloc(size)) == NULL) { | |
ff856286 | 697 | debug("himport_r: can't malloc %zu bytes\n", size); |
a6826fbc WD |
698 | __set_errno(ENOMEM); |
699 | return 0; | |
700 | } | |
701 | memcpy(data, env, size); | |
702 | dp = data; | |
703 | ||
d5370feb GF |
704 | /* make a local copy of the list of variables */ |
705 | if (nvars) | |
706 | memcpy(localvars, vars, sizeof(vars[0]) * nvars); | |
707 | ||
a6826fbc WD |
708 | if ((flag & H_NOCLEAR) == 0) { |
709 | /* Destroy old hash table if one exists */ | |
710 | debug("Destroy Hash Table: %p table = %p\n", htab, | |
711 | htab->table); | |
712 | if (htab->table) | |
c4e0057f | 713 | hdestroy_r(htab); |
a6826fbc WD |
714 | } |
715 | ||
716 | /* | |
717 | * Create new hash table (if needed). The computation of the hash | |
718 | * table size is based on heuristics: in a sample of some 70+ | |
719 | * existing systems we found an average size of 39+ bytes per entry | |
720 | * in the environment (for the whole key=value pair). Assuming a | |
ea882baf WD |
721 | * size of 8 per entry (= safety factor of ~5) should provide enough |
722 | * safety margin for any existing environment definitions and still | |
a6826fbc WD |
723 | * allow for more than enough dynamic additions. Note that the |
724 | * "size" argument is supposed to give the maximum enviroment size | |
ea882baf WD |
725 | * (CONFIG_ENV_SIZE). This heuristics will result in |
726 | * unreasonably large numbers (and thus memory footprint) for | |
727 | * big flash environments (>8,000 entries for 64 KB | |
fc5fc76b AB |
728 | * envrionment size), so we clip it to a reasonable value. |
729 | * On the other hand we need to add some more entries for free | |
730 | * space when importing very small buffers. Both boundaries can | |
731 | * be overwritten in the board config file if needed. | |
a6826fbc WD |
732 | */ |
733 | ||
734 | if (!htab->table) { | |
fc5fc76b | 735 | int nent = CONFIG_ENV_MIN_ENTRIES + size / 8; |
ea882baf WD |
736 | |
737 | if (nent > CONFIG_ENV_MAX_ENTRIES) | |
738 | nent = CONFIG_ENV_MAX_ENTRIES; | |
a6826fbc WD |
739 | |
740 | debug("Create Hash Table: N=%d\n", nent); | |
741 | ||
742 | if (hcreate_r(nent, htab) == 0) { | |
743 | free(data); | |
744 | return 0; | |
745 | } | |
746 | } | |
747 | ||
748 | /* Parse environment; allow for '\0' and 'sep' as separators */ | |
749 | do { | |
750 | ENTRY e, *rv; | |
751 | ||
752 | /* skip leading white space */ | |
4d91a6ec | 753 | while (isblank(*dp)) |
a6826fbc WD |
754 | ++dp; |
755 | ||
756 | /* skip comment lines */ | |
757 | if (*dp == '#') { | |
758 | while (*dp && (*dp != sep)) | |
759 | ++dp; | |
760 | ++dp; | |
761 | continue; | |
762 | } | |
763 | ||
764 | /* parse name */ | |
765 | for (name = dp; *dp != '=' && *dp && *dp != sep; ++dp) | |
766 | ; | |
767 | ||
768 | /* deal with "name" and "name=" entries (delete var) */ | |
769 | if (*dp == '\0' || *(dp + 1) == '\0' || | |
770 | *dp == sep || *(dp + 1) == sep) { | |
771 | if (*dp == '=') | |
772 | *dp++ = '\0'; | |
773 | *dp++ = '\0'; /* terminate name */ | |
774 | ||
775 | debug("DELETE CANDIDATE: \"%s\"\n", name); | |
d5370feb | 776 | if (!drop_var_from_set(name, nvars, localvars)) |
348b1f1c | 777 | continue; |
a6826fbc | 778 | |
c4e0057f | 779 | if (hdelete_r(name, htab, flag) == 0) |
a6826fbc WD |
780 | debug("DELETE ERROR ##############################\n"); |
781 | ||
782 | continue; | |
783 | } | |
784 | *dp++ = '\0'; /* terminate name */ | |
785 | ||
786 | /* parse value; deal with escapes */ | |
787 | for (value = sp = dp; *dp && (*dp != sep); ++dp) { | |
788 | if ((*dp == '\\') && *(dp + 1)) | |
789 | ++dp; | |
790 | *sp++ = *dp; | |
791 | } | |
792 | *sp++ = '\0'; /* terminate value */ | |
793 | ++dp; | |
794 | ||
348b1f1c | 795 | /* Skip variables which are not supposed to be processed */ |
d5370feb | 796 | if (!drop_var_from_set(name, nvars, localvars)) |
348b1f1c GF |
797 | continue; |
798 | ||
a6826fbc WD |
799 | /* enter into hash table */ |
800 | e.key = name; | |
801 | e.data = value; | |
802 | ||
c5983592 | 803 | /* if there is an apply function, check what it has to say */ |
c4e0057f | 804 | if (htab->apply != NULL) { |
c5983592 GF |
805 | debug("searching before calling cb function" |
806 | " for %s\n", name); | |
807 | /* | |
808 | * Search for variable in existing env, so to pass | |
809 | * its previous value to the apply callback | |
810 | */ | |
c4e0057f | 811 | hsearch_r(e, FIND, &rv, htab, 0); |
c5983592 GF |
812 | debug("previous value was %s\n", rv ? rv->data : ""); |
813 | if (htab->apply(name, rv ? rv->data : NULL, | |
814 | value, flag)) { | |
815 | debug("callback function refused to set" | |
816 | " variable %s, skipping it!\n", name); | |
817 | continue; | |
818 | } | |
819 | } | |
820 | ||
c4e0057f | 821 | hsearch_r(e, ENTER, &rv, htab, flag); |
a6826fbc | 822 | if (rv == NULL) { |
ea882baf WD |
823 | printf("himport_r: can't insert \"%s=%s\" into hash table\n", |
824 | name, value); | |
a6826fbc WD |
825 | return 0; |
826 | } | |
827 | ||
ea882baf WD |
828 | debug("INSERT: table %p, filled %d/%d rv %p ==> name=\"%s\" value=\"%s\"\n", |
829 | htab, htab->filled, htab->size, | |
830 | rv, name, value); | |
a6826fbc WD |
831 | } while ((dp < data + size) && *dp); /* size check needed for text */ |
832 | /* without '\0' termination */ | |
ea882baf | 833 | debug("INSERT: free(data = %p)\n", data); |
a6826fbc WD |
834 | free(data); |
835 | ||
d5370feb GF |
836 | /* process variables which were not considered */ |
837 | for (i = 0; i < nvars; i++) { | |
838 | if (localvars[i] == NULL) | |
839 | continue; | |
840 | /* | |
841 | * All variables which were not deleted from the variable list | |
842 | * were not present in the imported env | |
843 | * This could mean two things: | |
844 | * a) if the variable was present in current env, we delete it | |
845 | * b) if the variable was not present in current env, we notify | |
846 | * it might be a typo | |
847 | */ | |
c4e0057f | 848 | if (hdelete_r(localvars[i], htab, flag) == 0) |
d5370feb GF |
849 | printf("WARNING: '%s' neither in running nor in imported env!\n", localvars[i]); |
850 | else | |
851 | printf("WARNING: '%s' not in imported env, deleting it!\n", localvars[i]); | |
852 | } | |
853 | ||
ea882baf | 854 | debug("INSERT: done\n"); |
a6826fbc WD |
855 | return 1; /* everything OK */ |
856 | } |