keep unnamed sections unnamed on export
[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 if (name)
65 datalen += strlen(name) + 1;
66 ptr = uci_malloc(ctx, datalen);
67 e = (struct uci_element *) ptr;
68 e->type = type;
69 if (name) {
70 e->name = (char *) ptr + size;
71 strcpy(e->name, name);
72 }
73 uci_list_init(&e->list);
74
75 return e;
76 }
77
78 static void
79 uci_free_element(struct uci_element *e)
80 {
81 if (!uci_list_empty(&e->list))
82 uci_list_del(&e->list);
83 free(e);
84 }
85
86 static struct uci_option *
87 uci_alloc_option(struct uci_section *s, const char *name, const char *value)
88 {
89 struct uci_package *p = s->package;
90 struct uci_context *ctx = p->ctx;
91 struct uci_option *o;
92
93 o = uci_alloc_element(ctx, option, name, strlen(value) + 1);
94 o->value = uci_dataptr(o);
95 o->section = s;
96 strcpy(o->value, value);
97 uci_list_add(&s->options, &o->e.list);
98
99 return o;
100 }
101
102 static inline void
103 uci_free_option(struct uci_option *o)
104 {
105 if ((o->value != uci_dataptr(o)) &&
106 (o->value != NULL))
107 free(o->value);
108 uci_free_element(&o->e);
109 }
110
111 static struct uci_section *
112 uci_alloc_section(struct uci_package *p, const char *type, const char *name)
113 {
114 struct uci_context *ctx = p->ctx;
115 struct uci_section *s;
116
117 if (name && !name[0])
118 name = NULL;
119
120 s = uci_alloc_element(ctx, section, name, strlen(type) + 1);
121 uci_list_init(&s->options);
122 s->type = uci_dataptr(s);
123 s->package = p;
124 strcpy(s->type, type);
125 if (name == NULL)
126 s->anonymous = true;
127
128 uci_list_add(&p->sections, &s->e.list);
129
130 return s;
131 }
132
133 static void
134 uci_free_section(struct uci_section *s)
135 {
136 struct uci_element *o, *tmp;
137
138 uci_foreach_element_safe(&s->options, tmp, o) {
139 uci_free_option(uci_to_option(o));
140 }
141 if ((s->type != uci_dataptr(s)) &&
142 (s->type != NULL))
143 free(s->type);
144 uci_free_element(&s->e);
145 }
146
147 /* record a change that was done to a package */
148 static void
149 uci_add_history(struct uci_context *ctx, struct uci_package *p, int cmd, char *section, char *option, char *value)
150 {
151 struct uci_history *h;
152 int size = strlen(section) + 1;
153 char *ptr;
154
155 if (!p->confdir)
156 return;
157
158 if (value)
159 size += strlen(section) + 1;
160
161 h = uci_alloc_element(ctx, history, option, size);
162 ptr = uci_dataptr(h);
163 h->cmd = cmd;
164 h->section = strcpy(ptr, section);
165 if (value) {
166 ptr += strlen(ptr) + 1;
167 h->value = strcpy(ptr, value);
168 }
169 uci_list_add(&p->history, &h->e.list);
170 }
171
172 static void
173 uci_free_history(struct uci_history *h)
174 {
175 if (!h)
176 return;
177 if ((h->section != NULL) &&
178 (h->section != uci_dataptr(h))) {
179 free(h->section);
180 free(h->value);
181 }
182 uci_free_element(&h->e);
183 }
184
185 static struct uci_package *
186 uci_alloc_package(struct uci_context *ctx, const char *name)
187 {
188 struct uci_package *p;
189
190 p = uci_alloc_element(ctx, package, name, 0);
191 p->ctx = ctx;
192 uci_list_init(&p->sections);
193 uci_list_init(&p->history);
194 return p;
195 }
196
197 static void
198 uci_free_package(struct uci_package **package)
199 {
200 struct uci_element *e, *tmp;
201 struct uci_package *p = *package;
202
203 if(!p)
204 return;
205
206 if (p->path)
207 free(p->path);
208 uci_foreach_element_safe(&p->sections, tmp, e) {
209 uci_free_section(uci_to_section(e));
210 }
211 uci_foreach_element_safe(&p->history, tmp, e) {
212 uci_free_history(uci_to_history(e));
213 }
214 uci_free_element(&p->e);
215 *package = NULL;
216 }
217
218 static struct uci_element *uci_lookup_list(struct uci_context *ctx, struct uci_list *list, const char *name)
219 {
220 struct uci_element *e;
221
222 uci_foreach_element(list, e) {
223 if (!strcmp(e->name, name))
224 return e;
225 }
226 return NULL;
227 }
228
229 int uci_lookup(struct uci_context *ctx, struct uci_element **res, struct uci_package *p, char *section, char *option)
230 {
231 struct uci_element *e;
232 struct uci_section *s;
233 struct uci_option *o;
234
235 UCI_HANDLE_ERR(ctx);
236 UCI_ASSERT(ctx, res != NULL);
237 UCI_ASSERT(ctx, p != NULL);
238 UCI_ASSERT(ctx, section != NULL);
239
240 e = uci_lookup_list(ctx, &p->sections, section);
241 if (!e)
242 goto notfound;
243
244 if (option) {
245 s = uci_to_section(e);
246 e = uci_lookup_list(ctx, &s->options, option);
247 }
248
249 *res = e;
250 return 0;
251
252 notfound:
253 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
254 return 0;
255 }
256
257 int uci_del_element(struct uci_context *ctx, struct uci_element *e)
258 {
259 /* NB: UCI_INTERNAL use means without history tracking */
260 bool internal = ctx->internal;
261 struct uci_package *p = NULL;
262 struct uci_section *s = NULL;
263 struct uci_option *o = NULL;
264 struct uci_element *i, *tmp;
265 char *option = NULL;
266
267 UCI_HANDLE_ERR(ctx);
268 UCI_ASSERT(ctx, e != NULL);
269
270 switch(e->type) {
271 case UCI_TYPE_SECTION:
272 s = uci_to_section(e);
273 uci_foreach_element_safe(&s->options, tmp, i) {
274 uci_del_element(ctx, i);
275 }
276 break;
277 case UCI_TYPE_OPTION:
278 o = uci_to_option(e);
279 s = o->section;
280 p = s->package;
281 option = e->name;
282 break;
283 default:
284 UCI_THROW(ctx, UCI_ERR_INVAL);
285 break;
286 }
287
288 p = s->package;
289 if (!internal)
290 uci_add_history(ctx, p, UCI_CMD_REMOVE, s->e.name, option, NULL);
291
292 switch(e->type) {
293 case UCI_TYPE_SECTION:
294 uci_free_section(s);
295 break;
296 case UCI_TYPE_OPTION:
297 uci_free_option(o);
298 break;
299 default:
300 break;
301 }
302 return 0;
303 }
304
305 int uci_set_element_value(struct uci_context *ctx, struct uci_element **element, char *value)
306 {
307 /* NB: UCI_INTERNAL use means without history tracking */
308 bool internal = ctx->internal;
309 struct uci_list *list;
310 struct uci_element *e;
311 struct uci_package *p;
312 struct uci_section *s;
313 char *section;
314 char *option;
315 char *str;
316 int size;
317
318 UCI_HANDLE_ERR(ctx);
319 UCI_ASSERT(ctx, value != NULL);
320 UCI_ASSERT(ctx, element != NULL);
321 UCI_ASSERT(ctx, *element != NULL);
322
323 /* what the 'value' of an element means depends on the type
324 * for a section, the 'value' means its type
325 * for an option, the 'value' means its value string
326 * when changing the value, shrink the element to its actual size
327 * (it may have been allocated with a bigger size, to include
328 * its buffer)
329 * then duplicate the string passed on the command line and
330 * insert it into the structure.
331 */
332 e = *element;
333 list = e->list.prev;
334 switch(e->type) {
335 case UCI_TYPE_SECTION:
336 size = sizeof(struct uci_section);
337 s = uci_to_section(e);
338 section = e->name;
339 option = NULL;
340 break;
341 case UCI_TYPE_OPTION:
342 size = sizeof(struct uci_option);
343 s = uci_to_option(e)->section;
344 section = s->e.name;
345 option = e->name;
346 break;
347 default:
348 UCI_THROW(ctx, UCI_ERR_INVAL);
349 return 0;
350 }
351 p = s->package;
352 if (!internal)
353 uci_add_history(ctx, p, UCI_CMD_CHANGE, section, option, value);
354
355 uci_list_del(&e->list);
356 e = uci_realloc(ctx, e, size);
357 str = uci_strdup(ctx, value);
358 uci_list_insert(list, &e->list);
359 *element = e;
360
361 switch(e->type) {
362 case UCI_TYPE_SECTION:
363 uci_to_section(e)->type = str;
364 break;
365 case UCI_TYPE_OPTION:
366 uci_to_option(e)->value = str;
367 break;
368 default:
369 break;
370 }
371
372 return 0;
373 }
374
375 int uci_del(struct uci_context *ctx, struct uci_package *p, char *section, char *option)
376 {
377 /* NB: pass on internal flag to uci_del_element */
378 bool internal = ctx->internal;
379 struct uci_element *e;
380 struct uci_section *s = NULL;
381 struct uci_option *o = NULL;
382
383 UCI_HANDLE_ERR(ctx);
384 UCI_ASSERT(ctx, p != NULL);
385 UCI_ASSERT(ctx, section != NULL);
386
387 UCI_INTERNAL(uci_lookup, ctx, &e, p, section, option);
388
389 if (!internal)
390 return uci_del_element(ctx, e);
391 UCI_INTERNAL(uci_del_element, ctx, e);
392
393 return 0;
394 }
395
396 int uci_set(struct uci_context *ctx, struct uci_package *p, char *section, char *option, char *value)
397 {
398 /* NB: UCI_INTERNAL use means without history tracking */
399 bool internal = ctx->internal;
400 struct uci_element *e = NULL;
401 struct uci_section *s = NULL;
402 struct uci_option *o = NULL;
403 struct uci_history *h;
404
405 UCI_HANDLE_ERR(ctx);
406 UCI_ASSERT(ctx, p != NULL);
407 UCI_ASSERT(ctx, section != NULL);
408 UCI_ASSERT(ctx, value != NULL);
409
410 /*
411 * look up the package, section and option (if set)
412 * if the section/option is to be modified and it is not found
413 * create a new element in the appropriate list
414 */
415 e = uci_lookup_list(ctx, &p->sections, section);
416 if (!e)
417 goto notfound;
418
419 s = uci_to_section(e);
420 if (option) {
421 e = uci_lookup_list(ctx, &s->options, option);
422 if (!e)
423 goto notfound;
424 o = uci_to_option(e);
425 }
426
427 /*
428 * no unknown element was supplied, assume that we can just update
429 * an existing entry
430 */
431 if (o)
432 e = &o->e;
433 else
434 e = &s->e;
435
436 if (!internal)
437 return uci_set_element_value(ctx, &e, value);
438
439 UCI_INTERNAL(uci_set_element_value, ctx, &e, value);
440 return 0;
441
442 notfound:
443 /*
444 * the entry that we need to update was not found,
445 * check if the search failed prematurely.
446 * this can happen if the package was not found, or if
447 * an option was supplied, but the section wasn't found
448 */
449 if (!p || (!s && option))
450 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
451
452 /* now add the missing entry */
453 if (!internal)
454 uci_add_history(ctx, p, UCI_CMD_ADD, section, option, value);
455 if (s)
456 uci_alloc_option(s, option, value);
457 else
458 uci_alloc_section(p, value, section);
459
460 return 0;
461 }
462
463 int uci_unload(struct uci_context *ctx, struct uci_package *p)
464 {
465 struct uci_element *e;
466
467 UCI_HANDLE_ERR(ctx);
468 UCI_ASSERT(ctx, p != NULL);
469
470 uci_free_package(&p);
471 return 0;
472 }
473