rename ctx->errno to ctx->err to avoid conflicts with a #define errno in the system...
[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(struct uci_context *ctx, struct uci_element **res, struct uci_package *p, char *section, char *option)
232 {
233 struct uci_element *e;
234 struct uci_section *s;
235
236 UCI_HANDLE_ERR(ctx);
237 UCI_ASSERT(ctx, res != NULL);
238 UCI_ASSERT(ctx, p != NULL);
239 UCI_ASSERT(ctx, section && uci_validate_name(section));
240 if (option)
241 UCI_ASSERT(ctx, uci_validate_name(option));
242
243 e = uci_lookup_list(&p->sections, section);
244 if (!e)
245 goto notfound;
246
247 if (option) {
248 s = uci_to_section(e);
249 e = uci_lookup_list(&s->options, option);
250 if (!e)
251 goto notfound;
252 }
253
254 *res = e;
255 return 0;
256
257 notfound:
258 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
259 return 0;
260 }
261
262 int uci_del_element(struct uci_context *ctx, struct uci_element *e)
263 {
264 /* NB: UCI_INTERNAL use means without history tracking */
265 bool internal = ctx->internal;
266 struct uci_package *p = NULL;
267 struct uci_section *s = NULL;
268 struct uci_option *o = NULL;
269 struct uci_element *i, *tmp;
270 char *option = NULL;
271
272 UCI_HANDLE_ERR(ctx);
273 UCI_ASSERT(ctx, e != NULL);
274
275 switch(e->type) {
276 case UCI_TYPE_SECTION:
277 s = uci_to_section(e);
278 uci_foreach_element_safe(&s->options, tmp, i) {
279 uci_del_element(ctx, i);
280 }
281 break;
282 case UCI_TYPE_OPTION:
283 o = uci_to_option(e);
284 s = o->section;
285 p = s->package;
286 option = e->name;
287 break;
288 default:
289 UCI_THROW(ctx, UCI_ERR_INVAL);
290 break;
291 }
292
293 p = s->package;
294 if (!internal && p->has_history)
295 uci_add_history(ctx, &p->history, UCI_CMD_REMOVE, s->e.name, option, NULL);
296
297 switch(e->type) {
298 case UCI_TYPE_SECTION:
299 uci_free_section(s);
300 break;
301 case UCI_TYPE_OPTION:
302 uci_free_option(o);
303 break;
304 default:
305 break;
306 }
307 return 0;
308 }
309
310 int uci_set_element_value(struct uci_context *ctx, struct uci_element **element, char *value)
311 {
312 /* NB: UCI_INTERNAL use means without history tracking */
313 bool internal = ctx->internal;
314 struct uci_list *list;
315 struct uci_element *e;
316 struct uci_package *p;
317 struct uci_section *s;
318 char *section;
319 char *option;
320 char *str;
321 int size;
322
323 UCI_HANDLE_ERR(ctx);
324 UCI_ASSERT(ctx, (element != NULL) && (*element != NULL));
325
326 /* what the 'value' of an element means depends on the type
327 * for a section, the 'value' means its type
328 * for an option, the 'value' means its value string
329 * when changing the value, shrink the element to its actual size
330 * (it may have been allocated with a bigger size, to include
331 * its buffer)
332 * then duplicate the string passed on the command line and
333 * insert it into the structure.
334 */
335 e = *element;
336 list = e->list.prev;
337 switch(e->type) {
338 case UCI_TYPE_SECTION:
339 UCI_ASSERT(ctx, uci_validate_str(value, false));
340 size = sizeof(struct uci_section);
341 s = uci_to_section(e);
342 section = e->name;
343 option = NULL;
344 break;
345 case UCI_TYPE_OPTION:
346 UCI_ASSERT(ctx, value != NULL);
347 size = sizeof(struct uci_option);
348 s = uci_to_option(e)->section;
349 section = s->e.name;
350 option = e->name;
351 break;
352 default:
353 UCI_THROW(ctx, UCI_ERR_INVAL);
354 return 0;
355 }
356 p = s->package;
357 if (!internal && p->has_history)
358 uci_add_history(ctx, &p->history, UCI_CMD_CHANGE, section, option, value);
359
360 uci_list_del(&e->list);
361 e = uci_realloc(ctx, e, size);
362 str = uci_strdup(ctx, value);
363 uci_list_insert(list, &e->list);
364 *element = e;
365
366 switch(e->type) {
367 case UCI_TYPE_SECTION:
368 uci_to_section(e)->type = str;
369 break;
370 case UCI_TYPE_OPTION:
371 uci_to_option(e)->value = str;
372 break;
373 default:
374 break;
375 }
376
377 return 0;
378 }
379
380 int uci_rename(struct uci_context *ctx, struct uci_package *p, char *section, char *option, char *name)
381 {
382 /* NB: UCI_INTERNAL use means without history tracking */
383 bool internal = ctx->internal;
384 struct uci_element *e;
385
386 UCI_HANDLE_ERR(ctx);
387
388 /* NB: p, section, option validated by uci_lookup */
389 UCI_INTERNAL(uci_lookup, ctx, &e, p, section, option);
390
391 if (!internal && p->has_history)
392 uci_add_history(ctx, &p->history, UCI_CMD_RENAME, section, option, name);
393
394 name = uci_strdup(ctx, name);
395 if (e->name)
396 free(e->name);
397 e->name = name;
398
399 return 0;
400 }
401
402 int uci_add_section(struct uci_context *ctx, struct uci_package *p, char *type, struct uci_section **res)
403 {
404 bool internal = ctx->internal;
405 struct uci_section *s;
406
407 UCI_HANDLE_ERR(ctx);
408 UCI_ASSERT(ctx, p != NULL);
409 s = uci_alloc_section(p, type, NULL);
410 uci_fixup_section(ctx, s);
411 *res = s;
412 if (!internal && p->has_history)
413 uci_add_history(ctx, &p->history, UCI_CMD_ADD, s->e.name, NULL, type);
414
415 return 0;
416 }
417
418 int uci_delete(struct uci_context *ctx, struct uci_package *p, char *section, char *option)
419 {
420 /* NB: pass on internal flag to uci_del_element */
421 bool internal = ctx->internal;
422 struct uci_element *e;
423
424 UCI_HANDLE_ERR(ctx);
425
426 /* NB: p, section, option validated by uci_lookup */
427 UCI_INTERNAL(uci_lookup, ctx, &e, p, section, option);
428
429 ctx->internal = internal;
430 return uci_del_element(ctx, e);
431 }
432
433 int uci_set(struct uci_context *ctx, struct uci_package *p, char *section, char *option, char *value, struct uci_element **result)
434 {
435 /* NB: UCI_INTERNAL use means without history tracking */
436 bool internal = ctx->internal;
437 struct uci_element *e = NULL;
438 struct uci_section *s = NULL;
439 struct uci_option *o = NULL;
440
441 UCI_HANDLE_ERR(ctx);
442 UCI_ASSERT(ctx, p != NULL);
443 UCI_ASSERT(ctx, uci_validate_name(section));
444 if (option) {
445 UCI_ASSERT(ctx, uci_validate_name(option));
446 UCI_ASSERT(ctx, value != NULL);
447 } else {
448 UCI_ASSERT(ctx, uci_validate_str(value, false));
449 }
450
451 /*
452 * look up the package, section and option (if set)
453 * if the section/option is to be modified and it is not found
454 * create a new element in the appropriate list
455 */
456 e = uci_lookup_list(&p->sections, section);
457 if (!e)
458 goto notfound;
459
460 s = uci_to_section(e);
461 if (ctx->pctx && ctx->pctx->merge)
462 ctx->pctx->section = s;
463
464 if (option) {
465 e = uci_lookup_list(&s->options, option);
466 if (!e)
467 goto notfound;
468 o = uci_to_option(e);
469 }
470
471 /*
472 * no unknown element was supplied, assume that we can just update
473 * an existing entry
474 */
475 if (o)
476 e = &o->e;
477 else
478 e = &s->e;
479 if (result)
480 *result = e;
481 else
482 result = &e;
483
484 ctx->internal = internal;
485 return uci_set_element_value(ctx, result, value);
486
487 notfound:
488 /*
489 * the entry that we need to update was not found,
490 * check if the search failed prematurely.
491 * this can happen if the package was not found, or if
492 * an option was supplied, but the section wasn't found
493 */
494 if (!p || (!s && option))
495 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
496
497 /* now add the missing entry */
498 if (!internal && p->has_history)
499 uci_add_history(ctx, &p->history, UCI_CMD_CHANGE, section, option, value);
500 if (s) {
501 o = uci_alloc_option(s, option, value);
502 if (result)
503 *result = &o->e;
504 } else {
505 s = uci_alloc_section(p, value, section);
506 if (result)
507 *result = &s->e;
508 if (ctx->pctx && ctx->pctx->merge)
509 ctx->pctx->section = s;
510 }
511
512 return 0;
513 }
514
515 int uci_unload(struct uci_context *ctx, struct uci_package *p)
516 {
517 UCI_HANDLE_ERR(ctx);
518 UCI_ASSERT(ctx, p != NULL);
519
520 uci_free_package(&p);
521 return 0;
522 }
523