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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> | |
35 | ||
36 | # ifndef debug | |
37 | # ifdef DEBUG | |
38 | # define debug(fmt,args...) printf(fmt ,##args) | |
39 | # else | |
40 | # define debug(fmt,args...) | |
41 | # endif | |
42 | # endif | |
43 | #else /* U-Boot build */ | |
44 | # include <common.h> | |
45 | # include <linux/string.h> | |
46 | #endif | |
47 | ||
fc5fc76b AB |
48 | #ifndef CONFIG_ENV_MIN_ENTRIES /* minimum number of entries */ |
49 | #define CONFIG_ENV_MIN_ENTRIES 64 | |
50 | #endif | |
ea882baf WD |
51 | #ifndef CONFIG_ENV_MAX_ENTRIES /* maximum number of entries */ |
52 | #define CONFIG_ENV_MAX_ENTRIES 512 | |
53 | #endif | |
54 | ||
a6826fbc WD |
55 | #include "search.h" |
56 | ||
57 | /* | |
58 | * [Aho,Sethi,Ullman] Compilers: Principles, Techniques and Tools, 1986 | |
071bc923 | 59 | * [Knuth] The Art of Computer Programming, part 3 (6.4) |
a6826fbc WD |
60 | */ |
61 | ||
a6826fbc WD |
62 | /* |
63 | * The reentrant version has no static variables to maintain the state. | |
64 | * Instead the interface of all functions is extended to take an argument | |
65 | * which describes the current status. | |
66 | */ | |
67 | typedef struct _ENTRY { | |
c81c1222 | 68 | int used; |
a6826fbc WD |
69 | ENTRY entry; |
70 | } _ENTRY; | |
71 | ||
72 | ||
73 | /* | |
74 | * hcreate() | |
75 | */ | |
76 | ||
77 | /* | |
78 | * For the used double hash method the table size has to be a prime. To | |
79 | * correct the user given table size we need a prime test. This trivial | |
80 | * algorithm is adequate because | |
81 | * a) the code is (most probably) called a few times per program run and | |
82 | * b) the number is small because the table must fit in the core | |
83 | * */ | |
84 | static int isprime(unsigned int number) | |
85 | { | |
86 | /* no even number will be passed */ | |
87 | unsigned int div = 3; | |
88 | ||
89 | while (div * div < number && number % div != 0) | |
90 | div += 2; | |
91 | ||
92 | return number % div != 0; | |
93 | } | |
94 | ||
a6826fbc WD |
95 | /* |
96 | * Before using the hash table we must allocate memory for it. | |
97 | * Test for an existing table are done. We allocate one element | |
98 | * more as the found prime number says. This is done for more effective | |
99 | * indexing as explained in the comment for the hsearch function. | |
100 | * The contents of the table is zeroed, especially the field used | |
101 | * becomes zero. | |
102 | */ | |
2eb1573f | 103 | |
a6826fbc WD |
104 | int hcreate_r(size_t nel, struct hsearch_data *htab) |
105 | { | |
106 | /* Test for correct arguments. */ | |
107 | if (htab == NULL) { | |
108 | __set_errno(EINVAL); | |
109 | return 0; | |
110 | } | |
111 | ||
112 | /* There is still another table active. Return with error. */ | |
113 | if (htab->table != NULL) | |
114 | return 0; | |
115 | ||
116 | /* Change nel to the first prime number not smaller as nel. */ | |
117 | nel |= 1; /* make odd */ | |
118 | while (!isprime(nel)) | |
119 | nel += 2; | |
120 | ||
121 | htab->size = nel; | |
122 | htab->filled = 0; | |
123 | ||
124 | /* allocate memory and zero out */ | |
125 | htab->table = (_ENTRY *) calloc(htab->size + 1, sizeof(_ENTRY)); | |
126 | if (htab->table == NULL) | |
127 | return 0; | |
128 | ||
129 | /* everything went alright */ | |
130 | return 1; | |
131 | } | |
132 | ||
133 | ||
134 | /* | |
135 | * hdestroy() | |
136 | */ | |
a6826fbc WD |
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 | */ | |
2eb1573f | 142 | |
a6826fbc WD |
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) { | |
c81c1222 | 155 | if (htab->table[i].used > 0) { |
a6826fbc WD |
156 | ENTRY *ep = &htab->table[i].entry; |
157 | ||
84b5e802 | 158 | free((void *)ep->key); |
a6826fbc WD |
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 == 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 | ||
a000b795 KP |
205 | /* |
206 | * hstrstr_r - return index to entry whose key and/or data contains match | |
207 | */ | |
208 | int hstrstr_r(const char *match, int last_idx, ENTRY ** retval, | |
209 | struct hsearch_data *htab) | |
210 | { | |
211 | unsigned int idx; | |
212 | ||
213 | for (idx = last_idx + 1; idx < htab->size; ++idx) { | |
214 | if (htab->table[idx].used <= 0) | |
215 | continue; | |
216 | if (strstr(htab->table[idx].entry.key, match) || | |
217 | strstr(htab->table[idx].entry.data, match)) { | |
218 | *retval = &htab->table[idx].entry; | |
219 | return idx; | |
220 | } | |
221 | } | |
222 | ||
223 | __set_errno(ESRCH); | |
224 | *retval = NULL; | |
225 | return 0; | |
226 | } | |
227 | ||
560d424b MF |
228 | int hmatch_r(const char *match, int last_idx, ENTRY ** retval, |
229 | struct hsearch_data *htab) | |
230 | { | |
231 | unsigned int idx; | |
232 | size_t key_len = strlen(match); | |
233 | ||
234 | for (idx = last_idx + 1; idx < htab->size; ++idx) { | |
af4d9074 | 235 | if (htab->table[idx].used <= 0) |
560d424b MF |
236 | continue; |
237 | if (!strncmp(match, htab->table[idx].entry.key, key_len)) { | |
238 | *retval = &htab->table[idx].entry; | |
239 | return idx; | |
240 | } | |
241 | } | |
242 | ||
243 | __set_errno(ESRCH); | |
244 | *retval = NULL; | |
245 | return 0; | |
246 | } | |
247 | ||
a6826fbc WD |
248 | int hsearch_r(ENTRY item, ACTION action, ENTRY ** retval, |
249 | struct hsearch_data *htab) | |
250 | { | |
251 | unsigned int hval; | |
252 | unsigned int count; | |
253 | unsigned int len = strlen(item.key); | |
254 | unsigned int idx; | |
c81c1222 | 255 | unsigned int first_deleted = 0; |
a6826fbc WD |
256 | |
257 | /* Compute an value for the given string. Perhaps use a better method. */ | |
258 | hval = len; | |
259 | count = len; | |
260 | while (count-- > 0) { | |
261 | hval <<= 4; | |
262 | hval += item.key[count]; | |
263 | } | |
264 | ||
265 | /* | |
266 | * First hash function: | |
267 | * simply take the modul but prevent zero. | |
268 | */ | |
269 | hval %= htab->size; | |
270 | if (hval == 0) | |
271 | ++hval; | |
272 | ||
273 | /* The first index tried. */ | |
274 | idx = hval; | |
275 | ||
276 | if (htab->table[idx].used) { | |
277 | /* | |
071bc923 | 278 | * Further action might be required according to the |
a6826fbc WD |
279 | * action value. |
280 | */ | |
281 | unsigned hval2; | |
282 | ||
c81c1222 PB |
283 | if (htab->table[idx].used == -1 |
284 | && !first_deleted) | |
285 | first_deleted = idx; | |
286 | ||
a6826fbc WD |
287 | if (htab->table[idx].used == hval |
288 | && strcmp(item.key, htab->table[idx].entry.key) == 0) { | |
289 | /* Overwrite existing value? */ | |
290 | if ((action == ENTER) && (item.data != NULL)) { | |
291 | free(htab->table[idx].entry.data); | |
292 | htab->table[idx].entry.data = | |
293 | strdup(item.data); | |
294 | if (!htab->table[idx].entry.data) { | |
295 | __set_errno(ENOMEM); | |
296 | *retval = NULL; | |
297 | return 0; | |
298 | } | |
299 | } | |
300 | /* return found entry */ | |
301 | *retval = &htab->table[idx].entry; | |
302 | return idx; | |
303 | } | |
304 | ||
305 | /* | |
306 | * Second hash function: | |
307 | * as suggested in [Knuth] | |
308 | */ | |
309 | hval2 = 1 + hval % (htab->size - 2); | |
310 | ||
311 | do { | |
312 | /* | |
071bc923 WD |
313 | * Because SIZE is prime this guarantees to |
314 | * step through all available indices. | |
a6826fbc WD |
315 | */ |
316 | if (idx <= hval2) | |
317 | idx = htab->size + idx - hval2; | |
318 | else | |
319 | idx -= hval2; | |
320 | ||
321 | /* | |
322 | * If we visited all entries leave the loop | |
323 | * unsuccessfully. | |
324 | */ | |
325 | if (idx == hval) | |
326 | break; | |
327 | ||
328 | /* If entry is found use it. */ | |
329 | if ((htab->table[idx].used == hval) | |
330 | && strcmp(item.key, htab->table[idx].entry.key) == 0) { | |
331 | /* Overwrite existing value? */ | |
332 | if ((action == ENTER) && (item.data != NULL)) { | |
333 | free(htab->table[idx].entry.data); | |
334 | htab->table[idx].entry.data = | |
335 | strdup(item.data); | |
336 | if (!htab->table[idx].entry.data) { | |
337 | __set_errno(ENOMEM); | |
338 | *retval = NULL; | |
339 | return 0; | |
340 | } | |
341 | } | |
342 | /* return found entry */ | |
343 | *retval = &htab->table[idx].entry; | |
344 | return idx; | |
345 | } | |
346 | } | |
347 | while (htab->table[idx].used); | |
348 | } | |
349 | ||
350 | /* An empty bucket has been found. */ | |
351 | if (action == ENTER) { | |
352 | /* | |
071bc923 WD |
353 | * If table is full and another entry should be |
354 | * entered return with error. | |
a6826fbc WD |
355 | */ |
356 | if (htab->filled == htab->size) { | |
357 | __set_errno(ENOMEM); | |
358 | *retval = NULL; | |
359 | return 0; | |
360 | } | |
361 | ||
362 | /* | |
363 | * Create new entry; | |
364 | * create copies of item.key and item.data | |
365 | */ | |
c81c1222 PB |
366 | if (first_deleted) |
367 | idx = first_deleted; | |
368 | ||
a6826fbc WD |
369 | htab->table[idx].used = hval; |
370 | htab->table[idx].entry.key = strdup(item.key); | |
371 | htab->table[idx].entry.data = strdup(item.data); | |
372 | if (!htab->table[idx].entry.key || | |
373 | !htab->table[idx].entry.data) { | |
374 | __set_errno(ENOMEM); | |
375 | *retval = NULL; | |
376 | return 0; | |
377 | } | |
378 | ||
379 | ++htab->filled; | |
380 | ||
381 | /* return new entry */ | |
382 | *retval = &htab->table[idx].entry; | |
383 | return 1; | |
384 | } | |
385 | ||
386 | __set_errno(ESRCH); | |
387 | *retval = NULL; | |
388 | return 0; | |
389 | } | |
390 | ||
391 | ||
392 | /* | |
393 | * hdelete() | |
394 | */ | |
395 | ||
396 | /* | |
397 | * The standard implementation of hsearch(3) does not provide any way | |
398 | * to delete any entries from the hash table. We extend the code to | |
399 | * do that. | |
400 | */ | |
401 | ||
a6826fbc WD |
402 | int hdelete_r(const char *key, struct hsearch_data *htab) |
403 | { | |
404 | ENTRY e, *ep; | |
405 | int idx; | |
406 | ||
407 | debug("hdelete: DELETE key \"%s\"\n", key); | |
408 | ||
409 | e.key = (char *)key; | |
410 | ||
411 | if ((idx = hsearch_r(e, FIND, &ep, htab)) == 0) { | |
412 | __set_errno(ESRCH); | |
413 | return 0; /* not found */ | |
414 | } | |
415 | ||
416 | /* free used ENTRY */ | |
417 | debug("hdelete: DELETING key \"%s\"\n", key); | |
418 | ||
84b5e802 | 419 | free((void *)ep->key); |
a6826fbc | 420 | free(ep->data); |
c81c1222 | 421 | htab->table[idx].used = -1; |
a6826fbc WD |
422 | |
423 | --htab->filled; | |
424 | ||
425 | return 1; | |
426 | } | |
427 | ||
428 | /* | |
429 | * hexport() | |
430 | */ | |
431 | ||
432 | /* | |
433 | * Export the data stored in the hash table in linearized form. | |
434 | * | |
435 | * Entries are exported as "name=value" strings, separated by an | |
436 | * arbitrary (non-NUL, of course) separator character. This allows to | |
437 | * use this function both when formatting the U-Boot environment for | |
438 | * external storage (using '\0' as separator), but also when using it | |
439 | * for the "printenv" command to print all variables, simply by using | |
440 | * as '\n" as separator. This can also be used for new features like | |
441 | * exporting the environment data as text file, including the option | |
442 | * for later re-import. | |
443 | * | |
444 | * The entries in the result list will be sorted by ascending key | |
445 | * values. | |
446 | * | |
447 | * If the separator character is different from NUL, then any | |
448 | * separator characters and backslash characters in the values will | |
449 | * be escaped by a preceeding backslash in output. This is needed for | |
450 | * example to enable multi-line values, especially when the output | |
451 | * shall later be parsed (for example, for re-import). | |
452 | * | |
453 | * There are several options how the result buffer is handled: | |
454 | * | |
455 | * *resp size | |
456 | * ----------- | |
457 | * NULL 0 A string of sufficient length will be allocated. | |
458 | * NULL >0 A string of the size given will be | |
459 | * allocated. An error will be returned if the size is | |
460 | * not sufficient. Any unused bytes in the string will | |
461 | * be '\0'-padded. | |
462 | * !NULL 0 The user-supplied buffer will be used. No length | |
463 | * checking will be performed, i. e. it is assumed that | |
464 | * the buffer size will always be big enough. DANGEROUS. | |
465 | * !NULL >0 The user-supplied buffer will be used. An error will | |
466 | * be returned if the size is not sufficient. Any unused | |
467 | * bytes in the string will be '\0'-padded. | |
468 | */ | |
469 | ||
a6826fbc WD |
470 | static int cmpkey(const void *p1, const void *p2) |
471 | { | |
472 | ENTRY *e1 = *(ENTRY **) p1; | |
473 | ENTRY *e2 = *(ENTRY **) p2; | |
474 | ||
475 | return (strcmp(e1->key, e2->key)); | |
476 | } | |
477 | ||
478 | ssize_t hexport_r(struct hsearch_data *htab, const char sep, | |
479 | char **resp, size_t size) | |
480 | { | |
481 | ENTRY *list[htab->size]; | |
482 | char *res, *p; | |
483 | size_t totlen; | |
484 | int i, n; | |
485 | ||
486 | /* Test for correct arguments. */ | |
487 | if ((resp == NULL) || (htab == NULL)) { | |
488 | __set_errno(EINVAL); | |
489 | return (-1); | |
490 | } | |
491 | ||
492 | debug("EXPORT table = %p, htab.size = %d, htab.filled = %d, size = %d\n", | |
493 | htab, htab->size, htab->filled, size); | |
494 | /* | |
495 | * Pass 1: | |
496 | * search used entries, | |
497 | * save addresses and compute total length | |
498 | */ | |
499 | for (i = 1, n = 0, totlen = 0; i <= htab->size; ++i) { | |
500 | ||
c81c1222 | 501 | if (htab->table[i].used > 0) { |
a6826fbc WD |
502 | ENTRY *ep = &htab->table[i].entry; |
503 | ||
504 | list[n++] = ep; | |
505 | ||
506 | totlen += strlen(ep->key) + 2; | |
507 | ||
508 | if (sep == '\0') { | |
509 | totlen += strlen(ep->data); | |
510 | } else { /* check if escapes are needed */ | |
511 | char *s = ep->data; | |
512 | ||
513 | while (*s) { | |
514 | ++totlen; | |
515 | /* add room for needed escape chars */ | |
516 | if ((*s == sep) || (*s == '\\')) | |
517 | ++totlen; | |
518 | ++s; | |
519 | } | |
520 | } | |
521 | totlen += 2; /* for '=' and 'sep' char */ | |
522 | } | |
523 | } | |
524 | ||
525 | #ifdef DEBUG | |
526 | /* Pass 1a: print unsorted list */ | |
527 | printf("Unsorted: n=%d\n", n); | |
528 | for (i = 0; i < n; ++i) { | |
529 | printf("\t%3d: %p ==> %-10s => %s\n", | |
530 | i, list[i], list[i]->key, list[i]->data); | |
531 | } | |
532 | #endif | |
533 | ||
534 | /* Sort list by keys */ | |
535 | qsort(list, n, sizeof(ENTRY *), cmpkey); | |
536 | ||
537 | /* Check if the user supplied buffer size is sufficient */ | |
538 | if (size) { | |
539 | if (size < totlen + 1) { /* provided buffer too small */ | |
540 | debug("### buffer too small: %d, but need %d\n", | |
541 | size, totlen + 1); | |
542 | __set_errno(ENOMEM); | |
543 | return (-1); | |
544 | } | |
545 | } else { | |
546 | size = totlen + 1; | |
547 | } | |
548 | ||
549 | /* Check if the user provided a buffer */ | |
550 | if (*resp) { | |
551 | /* yes; clear it */ | |
552 | res = *resp; | |
553 | memset(res, '\0', size); | |
554 | } else { | |
555 | /* no, allocate and clear one */ | |
556 | *resp = res = calloc(1, size); | |
557 | if (res == NULL) { | |
558 | __set_errno(ENOMEM); | |
559 | return (-1); | |
560 | } | |
561 | } | |
562 | /* | |
563 | * Pass 2: | |
564 | * export sorted list of result data | |
565 | */ | |
566 | for (i = 0, p = res; i < n; ++i) { | |
84b5e802 | 567 | const char *s; |
a6826fbc WD |
568 | |
569 | s = list[i]->key; | |
570 | while (*s) | |
571 | *p++ = *s++; | |
572 | *p++ = '='; | |
573 | ||
574 | s = list[i]->data; | |
575 | ||
576 | while (*s) { | |
577 | if ((*s == sep) || (*s == '\\')) | |
578 | *p++ = '\\'; /* escape */ | |
579 | *p++ = *s++; | |
580 | } | |
581 | *p++ = sep; | |
582 | } | |
583 | *p = '\0'; /* terminate result */ | |
584 | ||
585 | return size; | |
586 | } | |
587 | ||
588 | ||
589 | /* | |
590 | * himport() | |
591 | */ | |
592 | ||
593 | /* | |
594 | * Import linearized data into hash table. | |
595 | * | |
596 | * This is the inverse function to hexport(): it takes a linear list | |
597 | * of "name=value" pairs and creates hash table entries from it. | |
598 | * | |
599 | * Entries without "value", i. e. consisting of only "name" or | |
600 | * "name=", will cause this entry to be deleted from the hash table. | |
601 | * | |
602 | * The "flag" argument can be used to control the behaviour: when the | |
603 | * H_NOCLEAR bit is set, then an existing hash table will kept, i. e. | |
604 | * new data will be added to an existing hash table; otherwise, old | |
605 | * data will be discarded and a new hash table will be created. | |
606 | * | |
607 | * The separator character for the "name=value" pairs can be selected, | |
608 | * so we both support importing from externally stored environment | |
609 | * data (separated by NUL characters) and from plain text files | |
610 | * (entries separated by newline characters). | |
611 | * | |
612 | * To allow for nicely formatted text input, leading white space | |
613 | * (sequences of SPACE and TAB chars) is ignored, and entries starting | |
614 | * (after removal of any leading white space) with a '#' character are | |
615 | * considered comments and ignored. | |
616 | * | |
617 | * [NOTE: this means that a variable name cannot start with a '#' | |
618 | * character.] | |
619 | * | |
620 | * When using a non-NUL separator character, backslash is used as | |
621 | * escape character in the value part, allowing for example for | |
622 | * multi-line values. | |
623 | * | |
624 | * In theory, arbitrary separator characters can be used, but only | |
625 | * '\0' and '\n' have really been tested. | |
626 | */ | |
627 | ||
a6826fbc WD |
628 | int himport_r(struct hsearch_data *htab, |
629 | const char *env, size_t size, const char sep, int flag) | |
630 | { | |
631 | char *data, *sp, *dp, *name, *value; | |
632 | ||
633 | /* Test for correct arguments. */ | |
634 | if (htab == NULL) { | |
635 | __set_errno(EINVAL); | |
636 | return 0; | |
637 | } | |
638 | ||
639 | /* we allocate new space to make sure we can write to the array */ | |
640 | if ((data = malloc(size)) == NULL) { | |
641 | debug("himport_r: can't malloc %d bytes\n", size); | |
642 | __set_errno(ENOMEM); | |
643 | return 0; | |
644 | } | |
645 | memcpy(data, env, size); | |
646 | dp = data; | |
647 | ||
648 | if ((flag & H_NOCLEAR) == 0) { | |
649 | /* Destroy old hash table if one exists */ | |
650 | debug("Destroy Hash Table: %p table = %p\n", htab, | |
651 | htab->table); | |
652 | if (htab->table) | |
653 | hdestroy_r(htab); | |
654 | } | |
655 | ||
656 | /* | |
657 | * Create new hash table (if needed). The computation of the hash | |
658 | * table size is based on heuristics: in a sample of some 70+ | |
659 | * existing systems we found an average size of 39+ bytes per entry | |
660 | * in the environment (for the whole key=value pair). Assuming a | |
ea882baf WD |
661 | * size of 8 per entry (= safety factor of ~5) should provide enough |
662 | * safety margin for any existing environment definitions and still | |
a6826fbc WD |
663 | * allow for more than enough dynamic additions. Note that the |
664 | * "size" argument is supposed to give the maximum enviroment size | |
ea882baf WD |
665 | * (CONFIG_ENV_SIZE). This heuristics will result in |
666 | * unreasonably large numbers (and thus memory footprint) for | |
667 | * big flash environments (>8,000 entries for 64 KB | |
fc5fc76b AB |
668 | * envrionment size), so we clip it to a reasonable value. |
669 | * On the other hand we need to add some more entries for free | |
670 | * space when importing very small buffers. Both boundaries can | |
671 | * be overwritten in the board config file if needed. | |
a6826fbc WD |
672 | */ |
673 | ||
674 | if (!htab->table) { | |
fc5fc76b | 675 | int nent = CONFIG_ENV_MIN_ENTRIES + size / 8; |
ea882baf WD |
676 | |
677 | if (nent > CONFIG_ENV_MAX_ENTRIES) | |
678 | nent = CONFIG_ENV_MAX_ENTRIES; | |
a6826fbc WD |
679 | |
680 | debug("Create Hash Table: N=%d\n", nent); | |
681 | ||
682 | if (hcreate_r(nent, htab) == 0) { | |
683 | free(data); | |
684 | return 0; | |
685 | } | |
686 | } | |
687 | ||
688 | /* Parse environment; allow for '\0' and 'sep' as separators */ | |
689 | do { | |
690 | ENTRY e, *rv; | |
691 | ||
692 | /* skip leading white space */ | |
693 | while ((*dp == ' ') || (*dp == '\t')) | |
694 | ++dp; | |
695 | ||
696 | /* skip comment lines */ | |
697 | if (*dp == '#') { | |
698 | while (*dp && (*dp != sep)) | |
699 | ++dp; | |
700 | ++dp; | |
701 | continue; | |
702 | } | |
703 | ||
704 | /* parse name */ | |
705 | for (name = dp; *dp != '=' && *dp && *dp != sep; ++dp) | |
706 | ; | |
707 | ||
708 | /* deal with "name" and "name=" entries (delete var) */ | |
709 | if (*dp == '\0' || *(dp + 1) == '\0' || | |
710 | *dp == sep || *(dp + 1) == sep) { | |
711 | if (*dp == '=') | |
712 | *dp++ = '\0'; | |
713 | *dp++ = '\0'; /* terminate name */ | |
714 | ||
715 | debug("DELETE CANDIDATE: \"%s\"\n", name); | |
716 | ||
717 | if (hdelete_r(name, htab) == 0) | |
718 | debug("DELETE ERROR ##############################\n"); | |
719 | ||
720 | continue; | |
721 | } | |
722 | *dp++ = '\0'; /* terminate name */ | |
723 | ||
724 | /* parse value; deal with escapes */ | |
725 | for (value = sp = dp; *dp && (*dp != sep); ++dp) { | |
726 | if ((*dp == '\\') && *(dp + 1)) | |
727 | ++dp; | |
728 | *sp++ = *dp; | |
729 | } | |
730 | *sp++ = '\0'; /* terminate value */ | |
731 | ++dp; | |
732 | ||
733 | /* enter into hash table */ | |
734 | e.key = name; | |
735 | e.data = value; | |
736 | ||
737 | hsearch_r(e, ENTER, &rv, htab); | |
738 | if (rv == NULL) { | |
ea882baf WD |
739 | printf("himport_r: can't insert \"%s=%s\" into hash table\n", |
740 | name, value); | |
a6826fbc WD |
741 | return 0; |
742 | } | |
743 | ||
ea882baf WD |
744 | debug("INSERT: table %p, filled %d/%d rv %p ==> name=\"%s\" value=\"%s\"\n", |
745 | htab, htab->filled, htab->size, | |
746 | rv, name, value); | |
a6826fbc WD |
747 | } while ((dp < data + size) && *dp); /* size check needed for text */ |
748 | /* without '\0' termination */ | |
ea882baf | 749 | debug("INSERT: free(data = %p)\n", data); |
a6826fbc WD |
750 | free(data); |
751 | ||
ea882baf | 752 | debug("INSERT: done\n"); |
a6826fbc WD |
753 | return 1; /* everything OK */ |
754 | } |