fix uci_set()
[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 void *ptr;
62
63 ptr = uci_malloc(ctx, size + strlen(name) + 1);
64 e = (struct uci_element *) ptr;
65 e->type = type;
66 e->name = (char *) ptr + size;
67 strcpy(e->name, name);
68 uci_list_init(&e->list);
69
70 return e;
71 }
72
73 static void
74 uci_free_element(struct uci_element *e)
75 {
76 if (!uci_list_empty(&e->list))
77 uci_list_del(&e->list);
78 free(e);
79 }
80
81 static struct uci_option *
82 uci_alloc_option(struct uci_section *s, const char *name, const char *value)
83 {
84 struct uci_package *p = s->package;
85 struct uci_context *ctx = p->ctx;
86 struct uci_option *o;
87
88 o = uci_alloc_element(ctx, option, name, strlen(value) + 1);
89 o->value = uci_dataptr(o);
90 o->section = s;
91 strcpy(o->value, value);
92 uci_list_add(&s->options, &o->e.list);
93
94 return o;
95 }
96
97 static inline void
98 uci_free_option(struct uci_option *o)
99 {
100 uci_free_element(&o->e);
101 }
102
103 static struct uci_section *
104 uci_alloc_section(struct uci_package *p, const char *type, const char *name)
105 {
106 struct uci_context *ctx = p->ctx;
107 struct uci_section *s;
108 char buf[16];
109
110 if (!name || !name[0]) {
111 snprintf(buf, 16, "cfg%d", p->n_section);
112 name = buf;
113 }
114
115 s = uci_alloc_element(ctx, section, name, strlen(type) + 1);
116 s->type = uci_dataptr(s);
117 s->package = p;
118 strcpy(s->type, type);
119 uci_list_init(&s->options);
120 uci_list_add(&p->sections, &s->e.list);
121
122 return s;
123 }
124
125 static void
126 uci_free_section(struct uci_section *s)
127 {
128 struct uci_element *o, *tmp;
129
130 uci_foreach_element_safe(&s->options, tmp, o) {
131 uci_free_option(uci_to_option(o));
132 }
133 uci_free_element(&s->e);
134 }
135
136 static struct uci_package *
137 uci_alloc_package(struct uci_context *ctx, const char *name)
138 {
139 struct uci_package *p;
140
141 p = uci_alloc_element(ctx, package, name, 0);
142 p->ctx = ctx;
143 uci_list_init(&p->sections);
144 uci_list_init(&p->history);
145 return p;
146 }
147
148 static void
149 uci_free_package(struct uci_package *p)
150 {
151 struct uci_element *e, *tmp;
152
153 if(!p)
154 return;
155
156 if (p->path)
157 free(p->path);
158 uci_foreach_element_safe(&p->sections, tmp, e) {
159 uci_free_section(uci_to_section(e));
160 }
161 uci_free_element(&p->e);
162 }
163
164 /* record a change that was done to a package */
165 static inline void
166 uci_add_history(struct uci_context *ctx, struct uci_package *p, int cmd, char *section, char *option, char *value)
167 {
168 struct uci_history *h = (struct uci_history *) uci_malloc(ctx, sizeof(struct uci_history));
169
170 uci_list_init(&h->list);
171 h->cmd = cmd;
172 h->section = section;
173 h->option = option;
174 h->value = value;
175 uci_list_add(&p->history, &h->list);
176 }
177
178
179 static struct uci_element *uci_lookup_list(struct uci_context *ctx, struct uci_list *list, const char *name)
180 {
181 struct uci_element *e;
182
183 uci_foreach_element(list, e) {
184 if (!strcmp(e->name, name))
185 return e;
186 }
187 return NULL;
188 }
189
190 int uci_lookup(struct uci_context *ctx, struct uci_element **res, struct uci_package *p, char *section, char *option)
191 {
192 struct uci_element *e;
193 struct uci_section *s;
194 struct uci_option *o;
195
196 UCI_HANDLE_ERR(ctx);
197 UCI_ASSERT(ctx, res != NULL);
198 UCI_ASSERT(ctx, p != NULL);
199 UCI_ASSERT(ctx, section != NULL);
200
201 e = uci_lookup_list(ctx, &p->sections, section);
202 if (!e)
203 goto notfound;
204
205 if (option) {
206 s = uci_to_section(e);
207 e = uci_lookup_list(ctx, &s->options, option);
208 }
209
210 *res = e;
211 return 0;
212
213 notfound:
214 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
215 return 0;
216 }
217
218 int uci_set_element_value(struct uci_context *ctx, struct uci_element **element, char *value)
219 {
220 int size;
221 char *str;
222 struct uci_list *list;
223 struct uci_element *e;
224
225 UCI_HANDLE_ERR(ctx);
226 UCI_ASSERT(ctx, value != NULL);
227 UCI_ASSERT(ctx, element != NULL);
228 UCI_ASSERT(ctx, *element != NULL);
229
230 /* what the 'value' of an element means depends on the type
231 * for a section, the 'value' means its type
232 * for an option, the 'value' means its value string
233 * when changing the value, shrink the element to its actual size
234 * (it may have been allocated with a bigger size, to include
235 * its buffer)
236 * then duplicate the string passed on the command line and
237 * insert it into the structure.
238 */
239 e = *element;
240 list = e->list.prev;
241 switch(e->type) {
242 case UCI_TYPE_SECTION:
243 size = sizeof(struct uci_section);
244 break;
245 case UCI_TYPE_OPTION:
246 size = sizeof(struct uci_option);
247 break;
248 default:
249 UCI_THROW(ctx, UCI_ERR_INVAL);
250 break;
251 }
252
253 uci_list_del(&e->list);
254 e = uci_realloc(ctx, e, size);
255 str = uci_strdup(ctx, value);
256 uci_list_insert(list, &e->list);
257 *element = e;
258
259 switch(e->type) {
260 case UCI_TYPE_SECTION:
261 uci_to_section(e)->type = value;
262 break;
263 case UCI_TYPE_OPTION:
264 uci_to_option(e)->value = value;
265 break;
266 default:
267 break;
268 }
269
270 return 0;
271 }
272
273 int uci_set(struct uci_context *ctx, char *package, char *section, char *option, char *value)
274 {
275 struct uci_element *e;
276 struct uci_package *p = NULL;
277 struct uci_section *s = NULL;
278 struct uci_option *o = NULL;
279 struct uci_history *h;
280
281 UCI_HANDLE_ERR(ctx);
282 UCI_ASSERT(ctx, package != NULL);
283 UCI_ASSERT(ctx, section != NULL);
284
285 /*
286 * look up the package, section and option (if set)
287 * if the section/option is to be modified and it is not found
288 * create a new element in the appropriate list
289 */
290 e = uci_lookup_list(ctx, &ctx->root, package);
291 if (!e)
292 goto notfound;
293
294 p = uci_to_package(e);
295 e = uci_lookup_list(ctx, &p->sections, section);
296 if (!e)
297 goto notfound;
298
299 s = uci_to_section(e);
300 if (option) {
301 e = uci_lookup_list(ctx, &s->options, option);
302 if (!e)
303 goto notfound;
304 o = uci_to_option(e);
305 }
306
307 /*
308 * no unknown element was supplied, assume that we can just update
309 * an existing entry
310 */
311 if (o)
312 e = &o->e;
313 else
314 e = &s->e;
315
316 uci_add_history(ctx, p, UCI_CMD_CHANGE, section, option, value);
317 return uci_set_element_value(ctx, &e, value);
318
319 notfound:
320 /*
321 * the entry that we need to update was not found,
322 * check if the search failed prematurely.
323 * this can happen if the package was not found, or if
324 * an option was supplied, but the section wasn't found
325 */
326 if (!p || (!s && option))
327 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
328
329 /* now add the missing entry */
330 uci_add_history(ctx, p, UCI_CMD_ADD, section, option, value);
331 if (s)
332 uci_alloc_option(s, option, value);
333 else
334 uci_alloc_section(p, value, section);
335
336 return 0;
337 }
338
339 int uci_unload(struct uci_context *ctx, struct uci_package *p)
340 {
341 struct uci_element *e;
342
343 UCI_HANDLE_ERR(ctx);
344 UCI_ASSERT(ctx, p != NULL);
345
346 uci_free_package(p);
347 return 0;
348 }
349