implement extended uci lookup syntax
[project/uci.git] / list.c
1 /*
2 * libuci - Library for the Unified Configuration Interface
3 * Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU Lesser General Public License version 2.1
7 * as published by the Free Software Foundation
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 */
14
15 #include <glob.h>
16
17 /* initialize a list head/item */
18 static inline void uci_list_init(struct uci_list *ptr)
19 {
20 ptr->prev = ptr;
21 ptr->next = ptr;
22 }
23
24 /* inserts a new list entry after a given entry */
25 static inline void uci_list_insert(struct uci_list *list, struct uci_list *ptr)
26 {
27 list->next->prev = ptr;
28 ptr->prev = list;
29 ptr->next = list->next;
30 list->next = ptr;
31 }
32
33 /* inserts a new list entry at the tail of the list */
34 static inline void uci_list_add(struct uci_list *head, struct uci_list *ptr)
35 {
36 /* NB: head->prev points at the tail */
37 uci_list_insert(head->prev, ptr);
38 }
39
40 static inline void uci_list_del(struct uci_list *ptr)
41 {
42 struct uci_list *next, *prev;
43
44 next = ptr->next;
45 prev = ptr->prev;
46
47 prev->next = next;
48 next->prev = prev;
49
50 uci_list_init(ptr);
51 }
52
53 /*
54 * uci_alloc_generic allocates a new uci_element with payload
55 * payload is appended to the struct to save memory and reduce fragmentation
56 */
57 static struct uci_element *
58 uci_alloc_generic(struct uci_context *ctx, int type, const char *name, int size)
59 {
60 struct uci_element *e;
61 int datalen = size;
62 void *ptr;
63
64 ptr = uci_malloc(ctx, datalen);
65 e = (struct uci_element *) ptr;
66 e->type = type;
67 if (name) {
68 UCI_TRAP_SAVE(ctx, error);
69 e->name = uci_strdup(ctx, name);
70 UCI_TRAP_RESTORE(ctx);
71 }
72 uci_list_init(&e->list);
73 goto done;
74
75 error:
76 free(ptr);
77 UCI_THROW(ctx, ctx->err);
78
79 done:
80 return e;
81 }
82
83 static void
84 uci_free_element(struct uci_element *e)
85 {
86 if (e->name)
87 free(e->name);
88 if (!uci_list_empty(&e->list))
89 uci_list_del(&e->list);
90 free(e);
91 }
92
93 static struct uci_option *
94 uci_alloc_option(struct uci_section *s, const char *name, const char *value)
95 {
96 struct uci_package *p = s->package;
97 struct uci_context *ctx = p->ctx;
98 struct uci_option *o;
99
100 o = uci_alloc_element(ctx, option, name, strlen(value) + 1);
101 o->value = uci_dataptr(o);
102 o->section = s;
103 strcpy(o->value, value);
104 uci_list_add(&s->options, &o->e.list);
105
106 return o;
107 }
108
109 static inline void
110 uci_free_option(struct uci_option *o)
111 {
112 if ((o->value != uci_dataptr(o)) &&
113 (o->value != NULL))
114 free(o->value);
115 uci_free_element(&o->e);
116 }
117
118 /* fix up an unnamed section, e.g. after adding options to it */
119 static void uci_fixup_section(struct uci_context *ctx, struct uci_section *s)
120 {
121 unsigned int hash = ~0;
122 struct uci_element *e;
123 char buf[16];
124
125 if (!s || s->e.name)
126 return;
127
128 /*
129 * Generate a name for unnamed sections. This is used as reference
130 * when locating or updating the section from apps/scripts.
131 * To make multiple concurrent versions somewhat safe for updating,
132 * the name is generated from a hash of its type and name/value
133 * pairs of its option, and it is prefixed by a counter value.
134 * If the order of the unnamed sections changes for some reason,
135 * updates to them will be rejected.
136 */
137 hash = djbhash(hash, s->type);
138 uci_foreach_element(&s->options, e) {
139 hash = djbhash(hash, e->name);
140 hash = djbhash(hash, uci_to_option(e)->value);
141 }
142 sprintf(buf, "cfg%02x%04x", ++s->package->n_section, hash % (1 << 16));
143 s->e.name = uci_strdup(ctx, buf);
144 }
145
146 static struct uci_section *
147 uci_alloc_section(struct uci_package *p, const char *type, const char *name)
148 {
149 struct uci_context *ctx = p->ctx;
150 struct uci_section *s;
151
152 if (name && !name[0])
153 name = NULL;
154
155 s = uci_alloc_element(ctx, section, name, strlen(type) + 1);
156 uci_list_init(&s->options);
157 s->type = uci_dataptr(s);
158 s->package = p;
159 strcpy(s->type, type);
160 if (name == NULL)
161 s->anonymous = true;
162 p->n_section++;
163
164 uci_list_add(&p->sections, &s->e.list);
165
166 return s;
167 }
168
169 static void
170 uci_free_section(struct uci_section *s)
171 {
172 struct uci_element *o, *tmp;
173
174 uci_foreach_element_safe(&s->options, tmp, o) {
175 uci_free_option(uci_to_option(o));
176 }
177 if ((s->type != uci_dataptr(s)) &&
178 (s->type != NULL))
179 free(s->type);
180 uci_free_element(&s->e);
181 }
182
183 __plugin struct uci_package *
184 uci_alloc_package(struct uci_context *ctx, const char *name)
185 {
186 struct uci_package *p;
187
188 p = uci_alloc_element(ctx, package, name, 0);
189 p->ctx = ctx;
190 uci_list_init(&p->sections);
191 uci_list_init(&p->history);
192 uci_list_init(&p->saved_history);
193 return p;
194 }
195
196 static void
197 uci_free_package(struct uci_package **package)
198 {
199 struct uci_element *e, *tmp;
200 struct uci_package *p = *package;
201
202 if(!p)
203 return;
204
205 if (p->path)
206 free(p->path);
207 uci_foreach_element_safe(&p->sections, tmp, e) {
208 uci_free_section(uci_to_section(e));
209 }
210 uci_foreach_element_safe(&p->history, tmp, e) {
211 uci_free_history(uci_to_history(e));
212 }
213 uci_foreach_element_safe(&p->saved_history, tmp, e) {
214 uci_free_history(uci_to_history(e));
215 }
216 uci_free_element(&p->e);
217 *package = NULL;
218 }
219
220 static struct uci_element *uci_lookup_list(struct uci_list *list, const char *name)
221 {
222 struct uci_element *e;
223
224 uci_foreach_element(list, e) {
225 if (!strcmp(e->name, name))
226 return e;
227 }
228 return NULL;
229 }
230
231 int uci_lookup_ext(struct uci_context *ctx, struct uci_element **res, char *ptr)
232 {
233 struct uci_package *p = NULL;
234 struct uci_element *e;
235 struct uci_section *s;
236 char *package = NULL;
237 char *section = NULL;
238 char *option = NULL;
239 char *idxstr, *t;
240 int idx, c;
241
242 UCI_HANDLE_ERR(ctx);
243 UCI_ASSERT(ctx, res != NULL);
244 UCI_ASSERT(ctx, ptr != NULL);
245
246 UCI_INTERNAL(uci_parse_tuple, ctx, ptr, &package, &section, &option, NULL);
247
248 /* look up the package first */
249 e = uci_lookup_list(&ctx->root, package);
250 if (!e) {
251 UCI_INTERNAL(uci_load, ctx, package, &p);
252 if (!p)
253 goto notfound;
254 e = &p->e;
255 } else {
256 p = uci_to_package(e);
257 }
258
259 if (!section)
260 goto done;
261
262 /* if the section name validates as a regular name, pass through
263 * to the regular uci_lookup function call */
264 if (!*section || uci_validate_name(section)) {
265 UCI_INTERNAL(uci_lookup, ctx, &e, p, section, option);
266 goto done;
267 }
268
269 /* name did not validate, that means we have an extended lookup call
270 * parse it here. for now only the section index syntax is supported */
271 if (section[0] != '@')
272 goto error;
273
274 section++;
275
276 /* parse the section index part */
277 idxstr = strchr(section, '[');
278 if (!idxstr)
279 goto error;
280 *idxstr = 0;
281 idxstr++;
282
283 t = strchr(idxstr, ']');
284 if (!t)
285 goto error;
286 if (t[1] != 0)
287 goto error;
288 *t = 0;
289
290 t = NULL;
291 idx = strtol(idxstr, &t, 10);
292 if (t && *t)
293 goto error;
294
295 if (!*section)
296 section = NULL;
297 if (section && !uci_validate_str(section, false))
298 goto error;
299
300 /* if the given index is negative, it specifies the section number from
301 * the end of the list */
302 if (idx < 0) {
303 c = 0;
304 uci_foreach_element(&p->sections, e) {
305 s = uci_to_section(e);
306 if (section && (strcmp(s->type, section) != 0))
307 continue;
308
309 c++;
310 }
311 idx += c;
312 }
313
314 c = 0;
315 uci_foreach_element(&p->sections, e) {
316 s = uci_to_section(e);
317 if (section && (strcmp(s->type, section) != 0))
318 continue;
319
320 if (idx == c)
321 goto found;
322 c++;
323 }
324 goto notfound;
325
326 found:
327 if (option)
328 e = uci_lookup_list(&s->options, option);
329 done:
330 *res = e;
331 return 0;
332
333 notfound:
334 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
335 error:
336 UCI_THROW(ctx, UCI_ERR_INVAL);
337 return 0;
338 }
339
340 int uci_lookup(struct uci_context *ctx, struct uci_element **res, struct uci_package *p, const char *section, const char *option)
341 {
342 struct uci_element *e;
343 struct uci_section *s;
344
345 UCI_HANDLE_ERR(ctx);
346 UCI_ASSERT(ctx, res != NULL);
347 UCI_ASSERT(ctx, p != NULL);
348 UCI_ASSERT(ctx, section && uci_validate_name(section));
349 if (option)
350 UCI_ASSERT(ctx, uci_validate_name(option));
351
352 e = uci_lookup_list(&p->sections, section);
353 if (!e)
354 goto notfound;
355
356 if (option) {
357 s = uci_to_section(e);
358 e = uci_lookup_list(&s->options, option);
359 if (!e)
360 goto notfound;
361 }
362
363 *res = e;
364 return 0;
365
366 notfound:
367 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
368 return 0;
369 }
370
371 int uci_del_element(struct uci_context *ctx, struct uci_element *e)
372 {
373 /* NB: UCI_INTERNAL use means without history tracking */
374 bool internal = ctx->internal;
375 struct uci_package *p = NULL;
376 struct uci_section *s = NULL;
377 struct uci_option *o = NULL;
378 struct uci_element *i, *tmp;
379 char *option = NULL;
380
381 UCI_HANDLE_ERR(ctx);
382 UCI_ASSERT(ctx, e != NULL);
383
384 switch(e->type) {
385 case UCI_TYPE_SECTION:
386 s = uci_to_section(e);
387 uci_foreach_element_safe(&s->options, tmp, i) {
388 uci_del_element(ctx, i);
389 }
390 break;
391 case UCI_TYPE_OPTION:
392 o = uci_to_option(e);
393 s = o->section;
394 p = s->package;
395 option = e->name;
396 break;
397 default:
398 UCI_THROW(ctx, UCI_ERR_INVAL);
399 break;
400 }
401
402 p = s->package;
403 if (!internal && p->has_history)
404 uci_add_history(ctx, &p->history, UCI_CMD_REMOVE, s->e.name, option, NULL);
405
406 switch(e->type) {
407 case UCI_TYPE_SECTION:
408 uci_free_section(s);
409 break;
410 case UCI_TYPE_OPTION:
411 uci_free_option(o);
412 break;
413 default:
414 break;
415 }
416 return 0;
417 }
418
419 int uci_set_element_value(struct uci_context *ctx, struct uci_element **element, const char *value)
420 {
421 /* NB: UCI_INTERNAL use means without history tracking */
422 bool internal = ctx->internal;
423 struct uci_list *list;
424 struct uci_element *e;
425 struct uci_package *p;
426 struct uci_section *s;
427 struct uci_option *o;
428 char *section;
429 char *option;
430 char *str;
431 int size;
432
433 UCI_HANDLE_ERR(ctx);
434 UCI_ASSERT(ctx, (element != NULL) && (*element != NULL));
435
436 /* what the 'value' of an element means depends on the type
437 * for a section, the 'value' means its type
438 * for an option, the 'value' means its value string
439 * when changing the value, shrink the element to its actual size
440 * (it may have been allocated with a bigger size, to include
441 * its buffer)
442 * then duplicate the string passed on the command line and
443 * insert it into the structure.
444 */
445 e = *element;
446 list = e->list.prev;
447 switch(e->type) {
448 case UCI_TYPE_SECTION:
449 UCI_ASSERT(ctx, uci_validate_str(value, false));
450 size = sizeof(struct uci_section);
451 s = uci_to_section(e);
452 section = e->name;
453 option = NULL;
454 /* matches the currently set value */
455 if (!strcmp(value, s->type))
456 return 0;
457 break;
458 case UCI_TYPE_OPTION:
459 UCI_ASSERT(ctx, value != NULL);
460 size = sizeof(struct uci_option);
461 o = uci_to_option(e);
462 s = o->section;
463 section = s->e.name;
464 option = o->e.name;
465 /* matches the currently set value */
466 if (!strcmp(value, o->value))
467 return 0;
468 break;
469 default:
470 UCI_THROW(ctx, UCI_ERR_INVAL);
471 return 0;
472 }
473 p = s->package;
474 if (!internal && p->has_history)
475 uci_add_history(ctx, &p->history, UCI_CMD_CHANGE, section, option, value);
476
477 uci_list_del(&e->list);
478 e = uci_realloc(ctx, e, size);
479 str = uci_strdup(ctx, value);
480 uci_list_insert(list, &e->list);
481 *element = e;
482
483 switch(e->type) {
484 case UCI_TYPE_SECTION:
485 uci_to_section(e)->type = str;
486 break;
487 case UCI_TYPE_OPTION:
488 uci_to_option(e)->value = str;
489 break;
490 default:
491 break;
492 }
493
494 return 0;
495 }
496
497 int uci_rename(struct uci_context *ctx, struct uci_package *p, char *section, char *option, char *name)
498 {
499 /* NB: UCI_INTERNAL use means without history tracking */
500 bool internal = ctx->internal;
501 struct uci_element *e;
502
503 UCI_HANDLE_ERR(ctx);
504
505 /* NB: p, section, option validated by uci_lookup */
506 UCI_INTERNAL(uci_lookup, ctx, &e, p, section, option);
507
508 if (!internal && p->has_history)
509 uci_add_history(ctx, &p->history, UCI_CMD_RENAME, section, option, name);
510
511 name = uci_strdup(ctx, name);
512 if (e->name)
513 free(e->name);
514 e->name = name;
515
516 return 0;
517 }
518
519 int uci_add_section(struct uci_context *ctx, struct uci_package *p, const char *type, struct uci_section **res)
520 {
521 bool internal = ctx->internal;
522 struct uci_section *s;
523
524 UCI_HANDLE_ERR(ctx);
525 UCI_ASSERT(ctx, p != NULL);
526 s = uci_alloc_section(p, type, NULL);
527 uci_fixup_section(ctx, s);
528 *res = s;
529 if (!internal && p->has_history)
530 uci_add_history(ctx, &p->history, UCI_CMD_ADD, s->e.name, NULL, type);
531
532 return 0;
533 }
534
535 int uci_delete(struct uci_context *ctx, struct uci_package *p, const char *section, const char *option)
536 {
537 /* NB: pass on internal flag to uci_del_element */
538 bool internal = ctx->internal;
539 struct uci_element *e;
540
541 UCI_HANDLE_ERR(ctx);
542
543 /* NB: p, section, option validated by uci_lookup */
544 UCI_INTERNAL(uci_lookup, ctx, &e, p, section, option);
545
546 ctx->internal = internal;
547 return uci_del_element(ctx, e);
548 }
549
550 int uci_set(struct uci_context *ctx, struct uci_package *p, const char *section, const char *option, const char *value, struct uci_element **result)
551 {
552 /* NB: UCI_INTERNAL use means without history tracking */
553 bool internal = ctx->internal;
554 struct uci_element *e = NULL;
555 struct uci_section *s = NULL;
556 struct uci_option *o = NULL;
557
558 UCI_HANDLE_ERR(ctx);
559 UCI_ASSERT(ctx, p != NULL);
560 UCI_ASSERT(ctx, uci_validate_name(section));
561 if (option) {
562 UCI_ASSERT(ctx, uci_validate_name(option));
563 UCI_ASSERT(ctx, value != NULL);
564 } else {
565 UCI_ASSERT(ctx, uci_validate_str(value, false));
566 }
567
568 /*
569 * look up the package, section and option (if set)
570 * if the section/option is to be modified and it is not found
571 * create a new element in the appropriate list
572 */
573 e = uci_lookup_list(&p->sections, section);
574 if (!e)
575 goto notfound;
576
577 s = uci_to_section(e);
578 if (ctx->pctx && ctx->pctx->merge)
579 ctx->pctx->section = s;
580
581 if (option) {
582 e = uci_lookup_list(&s->options, option);
583 if (!e)
584 goto notfound;
585 o = uci_to_option(e);
586 }
587
588 /*
589 * no unknown element was supplied, assume that we can just update
590 * an existing entry
591 */
592 if (o)
593 e = &o->e;
594 else
595 e = &s->e;
596 if (result)
597 *result = e;
598 else
599 result = &e;
600
601 ctx->internal = internal;
602 return uci_set_element_value(ctx, result, value);
603
604 notfound:
605 /*
606 * the entry that we need to update was not found,
607 * check if the search failed prematurely.
608 * this can happen if the package was not found, or if
609 * an option was supplied, but the section wasn't found
610 */
611 if (!p || (!s && option))
612 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
613
614 /* now add the missing entry */
615 if (!internal && p->has_history)
616 uci_add_history(ctx, &p->history, UCI_CMD_CHANGE, section, option, value);
617 if (s) {
618 o = uci_alloc_option(s, option, value);
619 if (result)
620 *result = &o->e;
621 } else {
622 s = uci_alloc_section(p, value, section);
623 if (result)
624 *result = &s->e;
625 if (ctx->pctx && ctx->pctx->merge)
626 ctx->pctx->section = s;
627 }
628
629 return 0;
630 }
631
632 int uci_unload(struct uci_context *ctx, struct uci_package *p)
633 {
634 UCI_HANDLE_ERR(ctx);
635 UCI_ASSERT(ctx, p != NULL);
636
637 uci_free_package(&p);
638 return 0;
639 }
640