e770234424ae92d2b7c109e64f28a847a9ee5ac9
[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 /* initialize a list head/item */
16 static inline void uci_list_init(struct uci_list *ptr)
17 {
18 ptr->prev = ptr;
19 ptr->next = ptr;
20 }
21
22 /* inserts a new list entry after a given entry */
23 static inline void uci_list_insert(struct uci_list *list, struct uci_list *ptr)
24 {
25 list->next->prev = ptr;
26 ptr->prev = list;
27 ptr->next = list->next;
28 list->next = ptr;
29 }
30
31 /* inserts a new list entry at the tail of the list */
32 static inline void uci_list_add(struct uci_list *head, struct uci_list *ptr)
33 {
34 /* NB: head->prev points at the tail */
35 uci_list_insert(head->prev, ptr);
36 }
37
38 static inline void uci_list_del(struct uci_list *ptr)
39 {
40 struct uci_list *next, *prev;
41
42 next = ptr->next;
43 prev = ptr->prev;
44
45 prev->next = next;
46 next->prev = prev;
47
48 uci_list_init(ptr);
49 }
50
51 /*
52 * uci_alloc_generic allocates a new uci_element with payload
53 * payload is appended to the struct to save memory and reduce fragmentation
54 */
55 static struct uci_element *
56 uci_alloc_generic(struct uci_context *ctx, int type, const char *name, int size)
57 {
58 struct uci_element *e;
59 int datalen = size;
60 void *ptr;
61
62 ptr = uci_malloc(ctx, datalen);
63 e = (struct uci_element *) ptr;
64 e->type = type;
65 if (name) {
66 UCI_TRAP_SAVE(ctx, error);
67 e->name = uci_strdup(ctx, name);
68 UCI_TRAP_RESTORE(ctx);
69 }
70 uci_list_init(&e->list);
71 goto done;
72
73 error:
74 free(ptr);
75 UCI_THROW(ctx, ctx->err);
76
77 done:
78 return e;
79 }
80
81 static void
82 uci_free_element(struct uci_element *e)
83 {
84 if (e->name)
85 free(e->name);
86 if (!uci_list_empty(&e->list))
87 uci_list_del(&e->list);
88 free(e);
89 }
90
91 static struct uci_option *
92 uci_alloc_option(struct uci_section *s, const char *name, const char *value)
93 {
94 struct uci_package *p = s->package;
95 struct uci_context *ctx = p->ctx;
96 struct uci_option *o;
97
98 o = uci_alloc_element(ctx, option, name, strlen(value) + 1);
99 o->type = UCI_TYPE_STRING;
100 o->v.string = uci_dataptr(o);
101 o->section = s;
102 strcpy(o->v.string, value);
103 uci_list_add(&s->options, &o->e.list);
104
105 return o;
106 }
107
108 static inline void
109 uci_free_option(struct uci_option *o)
110 {
111 struct uci_element *e, *tmp;
112
113 switch(o->type) {
114 case UCI_TYPE_STRING:
115 if ((o->v.string != uci_dataptr(o)) &&
116 (o->v.string != NULL))
117 free(o->v.string);
118 break;
119 case UCI_TYPE_LIST:
120 uci_foreach_element_safe(&o->v.list, tmp, e) {
121 uci_free_element(e);
122 }
123 break;
124 default:
125 break;
126 }
127 uci_free_element(&o->e);
128 }
129
130 static struct uci_option *
131 uci_alloc_list(struct uci_section *s, const char *name)
132 {
133 struct uci_package *p = s->package;
134 struct uci_context *ctx = p->ctx;
135 struct uci_option *o;
136
137 o = uci_alloc_element(ctx, option, name, 0);
138 o->type = UCI_TYPE_LIST;
139 o->section = s;
140 uci_list_init(&o->v.list);
141 uci_list_add(&s->options, &o->e.list);
142
143 return o;
144 }
145
146 /* fix up an unnamed section, e.g. after adding options to it */
147 static void uci_fixup_section(struct uci_context *ctx, struct uci_section *s)
148 {
149 unsigned int hash = ~0;
150 struct uci_element *e;
151 char buf[16];
152
153 if (!s || s->e.name)
154 return;
155
156 /*
157 * Generate a name for unnamed sections. This is used as reference
158 * when locating or updating the section from apps/scripts.
159 * To make multiple concurrent versions somewhat safe for updating,
160 * the name is generated from a hash of its type and name/value
161 * pairs of its option, and it is prefixed by a counter value.
162 * If the order of the unnamed sections changes for some reason,
163 * updates to them will be rejected.
164 */
165 hash = djbhash(hash, s->type);
166 uci_foreach_element(&s->options, e) {
167 struct uci_option *o;
168 hash = djbhash(hash, e->name);
169 o = uci_to_option(e);
170 switch(o->type) {
171 case UCI_TYPE_STRING:
172 hash = djbhash(hash, o->v.string);
173 break;
174 default:
175 break;
176 }
177 }
178 sprintf(buf, "cfg%02x%04x", ++s->package->n_section, hash % (1 << 16));
179 s->e.name = uci_strdup(ctx, buf);
180 }
181
182 static struct uci_section *
183 uci_alloc_section(struct uci_package *p, const char *type, const char *name)
184 {
185 struct uci_context *ctx = p->ctx;
186 struct uci_section *s;
187
188 if (name && !name[0])
189 name = NULL;
190
191 s = uci_alloc_element(ctx, section, name, strlen(type) + 1);
192 uci_list_init(&s->options);
193 s->type = uci_dataptr(s);
194 s->package = p;
195 strcpy(s->type, type);
196 if (name == NULL)
197 s->anonymous = true;
198 p->n_section++;
199
200 uci_list_add(&p->sections, &s->e.list);
201
202 return s;
203 }
204
205 static void
206 uci_free_section(struct uci_section *s)
207 {
208 struct uci_element *o, *tmp;
209
210 uci_foreach_element_safe(&s->options, tmp, o) {
211 uci_free_option(uci_to_option(o));
212 }
213 if ((s->type != uci_dataptr(s)) &&
214 (s->type != NULL))
215 free(s->type);
216 uci_free_element(&s->e);
217 }
218
219 __plugin struct uci_package *
220 uci_alloc_package(struct uci_context *ctx, const char *name)
221 {
222 struct uci_package *p;
223
224 p = uci_alloc_element(ctx, package, name, 0);
225 p->ctx = ctx;
226 uci_list_init(&p->sections);
227 uci_list_init(&p->history);
228 uci_list_init(&p->saved_history);
229 return p;
230 }
231
232 static void
233 uci_free_package(struct uci_package **package)
234 {
235 struct uci_element *e, *tmp;
236 struct uci_package *p = *package;
237
238 if(!p)
239 return;
240
241 if (p->path)
242 free(p->path);
243 uci_foreach_element_safe(&p->sections, tmp, e) {
244 uci_free_section(uci_to_section(e));
245 }
246 uci_foreach_element_safe(&p->history, tmp, e) {
247 uci_free_history(uci_to_history(e));
248 }
249 uci_foreach_element_safe(&p->saved_history, tmp, e) {
250 uci_free_history(uci_to_history(e));
251 }
252 uci_free_element(&p->e);
253 *package = NULL;
254 }
255
256 static void
257 uci_free_any(struct uci_element **e)
258 {
259 switch((*e)->type) {
260 case UCI_TYPE_SECTION:
261 uci_free_section(uci_to_section(*e));
262 break;
263 case UCI_TYPE_OPTION:
264 uci_free_option(uci_to_option(*e));
265 break;
266 default:
267 break;
268 }
269 *e = NULL;
270 }
271
272 static struct uci_element *uci_lookup_list(struct uci_list *list, const char *name)
273 {
274 struct uci_element *e;
275
276 uci_foreach_element(list, e) {
277 if (!strcmp(e->name, name))
278 return e;
279 }
280 return NULL;
281 }
282
283 static struct uci_element *uci_lookup_ext_section(struct uci_context *ctx, struct uci_ptr *ptr)
284 {
285 char *idxstr, *t, *section, *name;
286 struct uci_element *e = NULL;
287 struct uci_section *s;
288 int idx, c;
289
290 section = uci_strdup(ctx, ptr->section);
291 name = idxstr = section + 1;
292
293 if (section[0] != '@')
294 goto error;
295
296 /* parse the section index part */
297 idxstr = strchr(idxstr, '[');
298 if (!idxstr)
299 goto error;
300 *idxstr = 0;
301 idxstr++;
302
303 t = strchr(idxstr, ']');
304 if (!t)
305 goto error;
306 if (t[1] != 0)
307 goto error;
308 *t = 0;
309
310 t = NULL;
311 idx = strtol(idxstr, &t, 10);
312 if (t && *t)
313 goto error;
314
315 if (!*name)
316 name = NULL;
317 else if (!uci_validate_str(name, false))
318 goto error;
319
320 /* if the given index is negative, it specifies the section number from
321 * the end of the list */
322 if (idx < 0) {
323 c = 0;
324 uci_foreach_element(&ptr->p->sections, e) {
325 s = uci_to_section(e);
326 if (name && (strcmp(s->type, name) != 0))
327 continue;
328
329 c++;
330 }
331 idx += c;
332 }
333
334 c = 0;
335 uci_foreach_element(&ptr->p->sections, e) {
336 s = uci_to_section(e);
337 if (name && (strcmp(s->type, name) != 0))
338 continue;
339
340 if (idx == c)
341 goto done;
342 c++;
343 }
344 e = NULL;
345 goto done;
346
347 error:
348 e = NULL;
349 memset(ptr, 0, sizeof(struct uci_ptr));
350 UCI_THROW(ctx, UCI_ERR_INVAL);
351 done:
352 free(section);
353 return e;
354 }
355
356 int uci_lookup_ptr(struct uci_context *ctx, struct uci_ptr *ptr, char *str, bool extended)
357 {
358 struct uci_element *e;
359
360 UCI_HANDLE_ERR(ctx);
361 UCI_ASSERT(ctx, ptr != NULL);
362
363 if (str)
364 UCI_INTERNAL(uci_parse_ptr, ctx, ptr, str);
365
366 ptr->flags |= UCI_LOOKUP_DONE;
367
368 /* look up the package first */
369 e = uci_lookup_list(&ctx->root, ptr->package);
370 if (!e) {
371 UCI_INTERNAL(uci_load, ctx, ptr->package, &ptr->p);
372 if (!ptr->p)
373 goto notfound;
374 } else {
375 ptr->p = uci_to_package(e);
376 }
377
378 if (!ptr->section)
379 goto complete;
380
381 /* if the section name validates as a regular name, pass through
382 * to the regular uci_lookup function call */
383 if (ptr->flags & UCI_LOOKUP_EXTENDED)
384 e = uci_lookup_ext_section(ctx, ptr);
385 else
386 e = uci_lookup_list(&ptr->p->sections, ptr->section);
387
388 if (!e)
389 goto abort;
390
391 ptr->s = uci_to_section(e);
392
393 if (ptr->option) {
394 e = uci_lookup_list(&ptr->s->options, ptr->option);
395 if (!e)
396 goto abort;
397
398 ptr->o = uci_to_option(e);
399 }
400
401 complete:
402 ptr->flags |= UCI_LOOKUP_COMPLETE;
403 abort:
404 return 0;
405
406 notfound:
407 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
408 return 0;
409 }
410
411 int
412 uci_fill_ptr(struct uci_context *ctx, struct uci_ptr *ptr, struct uci_element *e, bool complete)
413 {
414 UCI_HANDLE_ERR(ctx);
415 UCI_ASSERT(ctx, ptr != NULL);
416 UCI_ASSERT(ctx, e != NULL);
417
418 memset(ptr, 0, sizeof(struct uci_ptr));
419 switch(e->type) {
420 case UCI_TYPE_OPTION:
421 ptr->o = uci_to_option(e);
422 goto fill_option;
423 case UCI_TYPE_SECTION:
424 ptr->s = uci_to_section(e);
425 goto fill_section;
426 case UCI_TYPE_PACKAGE:
427 ptr->p = uci_to_package(e);
428 goto fill_package;
429 default:
430 UCI_THROW(ctx, UCI_ERR_INVAL);
431 }
432
433 fill_option:
434 ptr->option = ptr->o->e.name;
435 ptr->s = ptr->o->section;
436 fill_section:
437 ptr->section = ptr->s->e.name;
438 ptr->p = ptr->s->package;
439 fill_package:
440 ptr->package = ptr->p->e.name;
441
442 ptr->flags |= UCI_LOOKUP_DONE;
443 if (complete)
444 ptr->flags |= UCI_LOOKUP_COMPLETE;
445
446 return 0;
447 }
448
449 static struct uci_element *
450 expand_ptr(struct uci_context *ctx, struct uci_ptr *ptr, bool complete)
451 {
452 UCI_ASSERT(ctx, ptr != NULL);
453
454 if (!(ptr->flags & UCI_LOOKUP_DONE))
455 uci_lookup_ptr(ctx, ptr, NULL, 1);
456 if (complete && !(ptr->flags & UCI_LOOKUP_COMPLETE))
457 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
458 UCI_ASSERT(ctx, ptr->p != NULL);
459
460 /* fill in missing string info */
461 if (ptr->p && !ptr->package)
462 ptr->package = ptr->p->e.name;
463 if (ptr->s && !ptr->section)
464 ptr->section = ptr->s->e.name;
465 if (ptr->o && !ptr->option)
466 ptr->option = ptr->o->e.name;
467
468 if (ptr->o)
469 return &ptr->o->e;
470 if (ptr->s)
471 return &ptr->s->e;
472 if (ptr->p)
473 return &ptr->p->e;
474 else
475 return NULL;
476 }
477
478 static void uci_add_element_list(struct uci_context *ctx, struct uci_ptr *ptr, bool internal)
479 {
480 struct uci_element *e;
481 struct uci_package *p;
482
483 p = ptr->p;
484 if (!internal && p->has_history)
485 uci_add_history(ctx, &p->history, UCI_CMD_LIST_ADD, ptr->section, ptr->option, ptr->value);
486
487 e = uci_alloc_generic(ctx, UCI_TYPE_ITEM, ptr->value, sizeof(struct uci_option));
488 uci_list_add(&ptr->o->v.list, &e->list);
489 }
490
491 int uci_set_element_value(struct uci_context *ctx, struct uci_element **element, const char *value)
492 {
493 /* NB: UCI_INTERNAL use means without history tracking */
494 bool internal = ctx->internal;
495 struct uci_list *list;
496 struct uci_element *e;
497 struct uci_package *p;
498 struct uci_section *s;
499 struct uci_option *o;
500 char *section;
501 char *option;
502 char *str;
503 int size = 0;
504
505 UCI_HANDLE_ERR(ctx);
506 UCI_ASSERT(ctx, (element != NULL) && (*element != NULL));
507
508 /* what the 'value' of an element means depends on the type
509 * for a section, the 'value' means its type
510 * for an option, the 'value' means its value string
511 * when changing the value, shrink the element to its actual size
512 * (it may have been allocated with a bigger size, to include
513 * its buffer)
514 * then duplicate the string passed on the command line and
515 * insert it into the structure.
516 */
517 e = *element;
518 list = e->list.prev;
519
520 switch(e->type) {
521 case UCI_TYPE_SECTION:
522 UCI_ASSERT(ctx, uci_validate_str(value, false));
523 size = sizeof(struct uci_section);
524 s = uci_to_section(e);
525 section = e->name;
526 option = NULL;
527 /* matches the currently set value */
528 if (!strcmp(value, s->type))
529 return 0;
530 break;
531
532 case UCI_TYPE_OPTION:
533 UCI_ASSERT(ctx, value != NULL);
534 o = uci_to_option(e);
535 s = o->section;
536 section = s->e.name;
537 option = o->e.name;
538 switch(o->type) {
539 case UCI_TYPE_STRING:
540 size = sizeof(struct uci_option);
541 /* matches the currently set value */
542 if (!strcmp(value, o->v.string))
543 return 0;
544 break;
545 default:
546 /* default action for non-string datatypes is to delete
547 * the existing entry, then re-create it as a string */
548 break;
549 }
550 break;
551
552 default:
553 UCI_THROW(ctx, UCI_ERR_INVAL);
554 return 0;
555 }
556 p = s->package;
557 if (!internal && p->has_history)
558 uci_add_history(ctx, &p->history, UCI_CMD_CHANGE, section, option, value);
559
560 if ((e->type == UCI_TYPE_OPTION) && (size == 0)) {
561 o = uci_alloc_option(s, option, value);
562 uci_free_any(&e);
563 *element = &o->e;
564 goto done;
565 }
566
567 uci_list_del(&e->list);
568 e = uci_realloc(ctx, e, size);
569 str = uci_strdup(ctx, value);
570 uci_list_insert(list, &e->list);
571 *element = e;
572
573 switch(e->type) {
574 case UCI_TYPE_SECTION:
575 uci_to_section(e)->type = str;
576 break;
577 case UCI_TYPE_OPTION:
578 uci_to_option(e)->v.string = str;
579 break;
580 default:
581 break;
582 }
583
584 done:
585 return 0;
586 }
587
588 int uci_rename(struct uci_context *ctx, struct uci_ptr *ptr)
589 {
590 /* NB: UCI_INTERNAL use means without history tracking */
591 bool internal = ctx->internal;
592 struct uci_element *e;
593 struct uci_package *p;
594 char *n;
595
596 UCI_HANDLE_ERR(ctx);
597
598 e = expand_ptr(ctx, ptr, true);
599 p = ptr->p;
600
601 UCI_ASSERT(ctx, ptr->s);
602 UCI_ASSERT(ctx, ptr->value);
603
604 if (!internal && p->has_history)
605 uci_add_history(ctx, &p->history, UCI_CMD_RENAME, ptr->section, ptr->option, ptr->value);
606
607 n = uci_strdup(ctx, ptr->value);
608 if (e->name)
609 free(e->name);
610 e->name = n;
611
612 return 0;
613 }
614
615 int uci_add_section(struct uci_context *ctx, struct uci_package *p, const char *type, struct uci_section **res)
616 {
617 bool internal = ctx->internal;
618 struct uci_section *s;
619
620 UCI_HANDLE_ERR(ctx);
621 UCI_ASSERT(ctx, p != NULL);
622 s = uci_alloc_section(p, type, NULL);
623 uci_fixup_section(ctx, s);
624 *res = s;
625 if (!internal && p->has_history)
626 uci_add_history(ctx, &p->history, UCI_CMD_ADD, s->e.name, NULL, type);
627
628 return 0;
629 }
630
631 int uci_delete(struct uci_context *ctx, struct uci_ptr *ptr)
632 {
633 /* NB: pass on internal flag to uci_del_element */
634 bool internal = ctx->internal;
635 struct uci_package *p;
636 struct uci_element *e;
637
638 UCI_HANDLE_ERR(ctx);
639
640 e = expand_ptr(ctx, ptr, true);
641 p = ptr->p;
642
643 UCI_ASSERT(ctx, ptr->s);
644
645 if (!internal && p->has_history)
646 uci_add_history(ctx, &p->history, UCI_CMD_REMOVE, ptr->section, ptr->option, NULL);
647
648 uci_free_any(&e);
649 return 0;
650 }
651
652 int uci_add_list(struct uci_context *ctx, struct uci_ptr *ptr)
653 {
654 /* NB: UCI_INTERNAL use means without history tracking */
655 bool internal = ctx->internal;
656 struct uci_option *prev = NULL;
657 const char *value2 = NULL;
658
659 UCI_HANDLE_ERR(ctx);
660
661 expand_ptr(ctx, ptr, false);
662 UCI_ASSERT(ctx, ptr->s);
663 UCI_ASSERT(ctx, ptr->value);
664
665 if (ptr->o) {
666 switch (ptr->o->type) {
667 case UCI_TYPE_STRING:
668 /* we already have a string value, convert that to a list */
669 prev = ptr->o;
670 value2 = ptr->value;
671 ptr->value = ptr->o->v.string;
672 break;
673 case UCI_TYPE_LIST:
674 uci_add_element_list(ctx, ptr, internal);
675 return 0;
676 default:
677 UCI_THROW(ctx, UCI_ERR_INVAL);
678 break;
679 }
680 }
681
682 ptr->o = uci_alloc_list(ptr->s, ptr->option);
683 if (prev) {
684 uci_add_element_list(ctx, ptr, true);
685 uci_free_option(prev);
686 ptr->value = value2;
687 }
688 uci_add_element_list(ctx, ptr, internal);
689
690 return 0;
691 }
692
693 int uci_set(struct uci_context *ctx, struct uci_package *p, const char *section, const char *option, const char *value, struct uci_element **result)
694 {
695 /* NB: UCI_INTERNAL use means without history tracking */
696 bool internal = ctx->internal;
697 struct uci_element *e = NULL;
698 struct uci_section *s = NULL;
699 struct uci_option *o = NULL;
700
701 UCI_HANDLE_ERR(ctx);
702 UCI_ASSERT(ctx, p != NULL);
703 UCI_ASSERT(ctx, uci_validate_name(section));
704 if (option) {
705 UCI_ASSERT(ctx, uci_validate_name(option));
706 UCI_ASSERT(ctx, value != NULL);
707 } else {
708 UCI_ASSERT(ctx, uci_validate_str(value, false));
709 }
710
711 /*
712 * look up the package, section and option (if set)
713 * if the section/option is to be modified and it is not found
714 * create a new element in the appropriate list
715 */
716 e = uci_lookup_list(&p->sections, section);
717 if (!e)
718 goto notfound;
719
720 s = uci_to_section(e);
721 if (ctx->pctx && ctx->pctx->merge)
722 ctx->pctx->section = s;
723
724 if (option) {
725 e = uci_lookup_list(&s->options, option);
726 if (!e)
727 goto notfound;
728 o = uci_to_option(e);
729 }
730
731 /*
732 * no unknown element was supplied, assume that we can just update
733 * an existing entry
734 */
735 if (o)
736 e = &o->e;
737 else
738 e = &s->e;
739 if (result)
740 *result = e;
741 else
742 result = &e;
743
744 ctx->internal = internal;
745 return uci_set_element_value(ctx, result, value);
746
747 notfound:
748 /*
749 * the entry that we need to update was not found,
750 * check if the search failed prematurely.
751 * this can happen if the package was not found, or if
752 * an option was supplied, but the section wasn't found
753 */
754 if (!p || (!s && option))
755 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
756
757 /* now add the missing entry */
758 if (!internal && p->has_history)
759 uci_add_history(ctx, &p->history, UCI_CMD_CHANGE, section, option, value);
760 if (s) {
761 o = uci_alloc_option(s, option, value);
762 if (result)
763 *result = &o->e;
764 } else {
765 s = uci_alloc_section(p, value, section);
766 if (result)
767 *result = &s->e;
768 if (ctx->pctx && ctx->pctx->merge)
769 ctx->pctx->section = s;
770 }
771
772 return 0;
773 }
774
775 int uci_unload(struct uci_context *ctx, struct uci_package *p)
776 {
777 UCI_HANDLE_ERR(ctx);
778 UCI_ASSERT(ctx, p != NULL);
779
780 uci_free_package(&p);
781 return 0;
782 }
783