111321cdb7d97f26c840a4b1c36d55f53589bd59
[project/uci.git] / delta.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 Lesser General Public License for more details.
13 */
14
15 /*
16 * This file contains the code for handling uci config delta files
17 */
18
19 #define _GNU_SOURCE
20 #include <sys/types.h>
21 #include <sys/stat.h>
22 #include <sys/file.h>
23 #include <stdbool.h>
24 #include <unistd.h>
25 #include <fcntl.h>
26 #include <stdio.h>
27 #include <ctype.h>
28 #include <string.h>
29 #include <stdlib.h>
30
31 #include "uci.h"
32 #include "uci_internal.h"
33
34 /* record a change that was done to a package */
35 void
36 uci_add_delta(struct uci_context *ctx, struct uci_list *list, int cmd, const char *section, const char *option, const char *value)
37 {
38 struct uci_delta *h;
39 int size = strlen(section) + 1;
40 char *ptr;
41
42 if (value)
43 size += strlen(value) + 1;
44
45 h = uci_alloc_element(ctx, delta, option, size);
46 ptr = uci_dataptr(h);
47 h->cmd = cmd;
48 h->section = strcpy(ptr, section);
49 if (value) {
50 ptr += strlen(ptr) + 1;
51 h->value = strcpy(ptr, value);
52 }
53 uci_list_add(list, &h->e.list);
54 }
55
56 void
57 uci_free_delta(struct uci_delta *h)
58 {
59 if (!h)
60 return;
61 if ((h->section != NULL) &&
62 (h->section != uci_dataptr(h))) {
63 free(h->section);
64 free(h->value);
65 }
66 uci_free_element(&h->e);
67 }
68
69
70 int uci_set_savedir(struct uci_context *ctx, const char *dir)
71 {
72 char *sdir;
73
74 UCI_HANDLE_ERR(ctx);
75 UCI_ASSERT(ctx, dir != NULL);
76
77 sdir = uci_strdup(ctx, dir);
78 if (ctx->savedir != uci_savedir)
79 free(ctx->savedir);
80 ctx->savedir = sdir;
81 return 0;
82 }
83
84 int uci_add_delta_path(struct uci_context *ctx, const char *dir)
85 {
86 struct uci_element *e;
87
88 UCI_HANDLE_ERR(ctx);
89 UCI_ASSERT(ctx, dir != NULL);
90 e = uci_alloc_generic(ctx, UCI_TYPE_PATH, dir, sizeof(struct uci_element));
91 uci_list_add(&ctx->delta_path, &e->list);
92
93 return 0;
94 }
95
96 static inline int uci_parse_delta_tuple(struct uci_context *ctx, char **buf, struct uci_ptr *ptr)
97 {
98 int c = UCI_CMD_CHANGE;
99
100 switch(**buf) {
101 case '^':
102 c = UCI_CMD_REORDER;
103 break;
104 case '-':
105 c = UCI_CMD_REMOVE;
106 break;
107 case '@':
108 c = UCI_CMD_RENAME;
109 break;
110 case '+':
111 /* UCI_CMD_ADD is used for anonymous sections or list values */
112 c = UCI_CMD_ADD;
113 break;
114 case '|':
115 c = UCI_CMD_LIST_ADD;
116 break;
117 case '_':
118 c = UCI_CMD_LIST_DEL;
119 break;
120 }
121
122 if (c != UCI_CMD_CHANGE)
123 *buf += 1;
124
125 UCI_INTERNAL(uci_parse_ptr, ctx, ptr, *buf);
126
127 if (!ptr->section)
128 goto error;
129 if (ptr->flags & UCI_LOOKUP_EXTENDED)
130 goto error;
131
132 switch(c) {
133 case UCI_CMD_REORDER:
134 if (!ptr->value || ptr->option)
135 goto error;
136 break;
137 case UCI_CMD_RENAME:
138 if (!ptr->value || !uci_validate_name(ptr->value))
139 goto error;
140 break;
141 case UCI_CMD_LIST_ADD:
142 if (!ptr->option)
143 goto error;
144 case UCI_CMD_LIST_DEL:
145 if (!ptr->option)
146 goto error;
147 }
148
149 return c;
150
151 error:
152 UCI_THROW(ctx, UCI_ERR_INVAL);
153 return 0;
154 }
155
156 static void uci_parse_delta_line(struct uci_context *ctx, struct uci_package *p, char *buf)
157 {
158 struct uci_element *e = NULL;
159 struct uci_ptr ptr;
160 int cmd;
161
162 cmd = uci_parse_delta_tuple(ctx, &buf, &ptr);
163 if (strcmp(ptr.package, p->e.name) != 0)
164 goto error;
165
166 if (ctx->flags & UCI_FLAG_SAVED_DELTA)
167 uci_add_delta(ctx, &p->saved_delta, cmd, ptr.section, ptr.option, ptr.value);
168
169 switch(cmd) {
170 case UCI_CMD_REORDER:
171 uci_expand_ptr(ctx, &ptr, true);
172 if (!ptr.s)
173 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
174 UCI_INTERNAL(uci_reorder_section, ctx, ptr.s, strtoul(ptr.value, NULL, 10));
175 break;
176 case UCI_CMD_RENAME:
177 UCI_INTERNAL(uci_rename, ctx, &ptr);
178 break;
179 case UCI_CMD_REMOVE:
180 UCI_INTERNAL(uci_delete, ctx, &ptr);
181 break;
182 case UCI_CMD_LIST_ADD:
183 UCI_INTERNAL(uci_add_list, ctx, &ptr);
184 break;
185 case UCI_CMD_LIST_DEL:
186 UCI_INTERNAL(uci_del_list, ctx, &ptr);
187 break;
188 case UCI_CMD_ADD:
189 case UCI_CMD_CHANGE:
190 UCI_INTERNAL(uci_set, ctx, &ptr);
191 e = ptr.last;
192 if (!ptr.option && e && (cmd == UCI_CMD_ADD))
193 uci_to_section(e)->anonymous = true;
194 break;
195 }
196 return;
197 error:
198 UCI_THROW(ctx, UCI_ERR_PARSE);
199 }
200
201 /* returns the number of changes that were successfully parsed */
202 static int uci_parse_delta(struct uci_context *ctx, FILE *stream, struct uci_package *p)
203 {
204 struct uci_parse_context *pctx;
205 int changes = 0;
206
207 /* make sure no memory from previous parse attempts is leaked */
208 uci_cleanup(ctx);
209
210 pctx = (struct uci_parse_context *) uci_malloc(ctx, sizeof(struct uci_parse_context));
211 ctx->pctx = pctx;
212 pctx->file = stream;
213
214 while (!feof(pctx->file)) {
215 uci_getln(ctx, 0);
216 if (!pctx->buf[0])
217 continue;
218
219 /*
220 * ignore parse errors in single lines, we want to preserve as much
221 * delta as possible
222 */
223 UCI_TRAP_SAVE(ctx, error);
224 uci_parse_delta_line(ctx, p, pctx->buf);
225 UCI_TRAP_RESTORE(ctx);
226 changes++;
227 error:
228 continue;
229 }
230
231 /* no error happened, we can get rid of the parser context now */
232 uci_cleanup(ctx);
233 return changes;
234 }
235
236 /* returns the number of changes that were successfully parsed */
237 static int uci_load_delta_file(struct uci_context *ctx, struct uci_package *p, char *filename, FILE **f, bool flush)
238 {
239 FILE *stream = NULL;
240 int changes = 0;
241
242 UCI_TRAP_SAVE(ctx, done);
243 stream = uci_open_stream(ctx, filename, SEEK_SET, flush, false);
244 if (p)
245 changes = uci_parse_delta(ctx, stream, p);
246 UCI_TRAP_RESTORE(ctx);
247 done:
248 if (f)
249 *f = stream;
250 else if (stream)
251 uci_close_stream(stream);
252 return changes;
253 }
254
255 /* returns the number of changes that were successfully parsed */
256 __private int uci_load_delta(struct uci_context *ctx, struct uci_package *p, bool flush)
257 {
258 struct uci_element *e;
259 char *filename = NULL;
260 FILE *f = NULL;
261 int changes = 0;
262
263 if (!p->has_delta)
264 return 0;
265
266 uci_foreach_element(&ctx->delta_path, e) {
267 if ((asprintf(&filename, "%s/%s", e->name, p->e.name) < 0) || !filename)
268 UCI_THROW(ctx, UCI_ERR_MEM);
269
270 uci_load_delta_file(ctx, p, filename, NULL, false);
271 free(filename);
272 }
273
274 if ((asprintf(&filename, "%s/%s", ctx->savedir, p->e.name) < 0) || !filename)
275 UCI_THROW(ctx, UCI_ERR_MEM);
276
277 changes = uci_load_delta_file(ctx, p, filename, &f, flush);
278 if (flush && f && (changes > 0)) {
279 rewind(f);
280 if (ftruncate(fileno(f), 0) < 0) {
281 uci_close_stream(f);
282 UCI_THROW(ctx, UCI_ERR_IO);
283 }
284 }
285 if (filename)
286 free(filename);
287 uci_close_stream(f);
288 ctx->err = 0;
289 return changes;
290 }
291
292 static void uci_filter_delta(struct uci_context *ctx, const char *name, const char *section, const char *option)
293 {
294 struct uci_parse_context *pctx;
295 struct uci_element *e, *tmp;
296 struct uci_list list;
297 char *filename = NULL;
298 struct uci_ptr ptr;
299 FILE *f = NULL;
300
301 uci_list_init(&list);
302 uci_alloc_parse_context(ctx);
303 pctx = ctx->pctx;
304
305 if ((asprintf(&filename, "%s/%s", ctx->savedir, name) < 0) || !filename)
306 UCI_THROW(ctx, UCI_ERR_MEM);
307
308 UCI_TRAP_SAVE(ctx, done);
309 f = uci_open_stream(ctx, filename, SEEK_SET, true, false);
310 pctx->file = f;
311 while (!feof(f)) {
312 struct uci_element *e;
313 char *buf;
314
315 uci_getln(ctx, 0);
316 buf = pctx->buf;
317 if (!buf[0])
318 continue;
319
320 /* NB: need to allocate the element before the call to
321 * uci_parse_delta_tuple, otherwise the original string
322 * gets modified before it is saved */
323 e = uci_alloc_generic(ctx, UCI_TYPE_DELTA, pctx->buf, sizeof(struct uci_element));
324 uci_list_add(&list, &e->list);
325
326 uci_parse_delta_tuple(ctx, &buf, &ptr);
327 if (section) {
328 if (!ptr.section || (strcmp(section, ptr.section) != 0))
329 continue;
330 }
331 if (option) {
332 if (!ptr.option || (strcmp(option, ptr.option) != 0))
333 continue;
334 }
335 /* match, drop this element again */
336 uci_free_element(e);
337 }
338
339 /* rebuild the delta file */
340 rewind(f);
341 if (ftruncate(fileno(f), 0) < 0)
342 UCI_THROW(ctx, UCI_ERR_IO);
343 uci_foreach_element_safe(&list, tmp, e) {
344 fprintf(f, "%s\n", e->name);
345 uci_free_element(e);
346 }
347 UCI_TRAP_RESTORE(ctx);
348
349 done:
350 if (filename)
351 free(filename);
352 uci_close_stream(pctx->file);
353 uci_foreach_element_safe(&list, tmp, e) {
354 uci_free_element(e);
355 }
356 uci_cleanup(ctx);
357 }
358
359 int uci_revert(struct uci_context *ctx, struct uci_ptr *ptr)
360 {
361 char *package = NULL;
362 char *section = NULL;
363 char *option = NULL;
364
365 UCI_HANDLE_ERR(ctx);
366 uci_expand_ptr(ctx, ptr, false);
367 UCI_ASSERT(ctx, ptr->p->has_delta);
368
369 /*
370 * - flush unwritten changes
371 * - save the package name
372 * - unload the package
373 * - filter the delta
374 * - reload the package
375 */
376 UCI_TRAP_SAVE(ctx, error);
377 UCI_INTERNAL(uci_save, ctx, ptr->p);
378
379 /* NB: need to clone package, section and option names,
380 * as they may get freed on uci_free_package() */
381 package = uci_strdup(ctx, ptr->p->e.name);
382 if (ptr->section)
383 section = uci_strdup(ctx, ptr->section);
384 if (ptr->option)
385 option = uci_strdup(ctx, ptr->option);
386
387 uci_free_package(&ptr->p);
388 uci_filter_delta(ctx, package, section, option);
389
390 UCI_INTERNAL(uci_load, ctx, package, &ptr->p);
391 UCI_TRAP_RESTORE(ctx);
392 ctx->err = 0;
393
394 error:
395 if (package)
396 free(package);
397 if (section)
398 free(section);
399 if (option)
400 free(option);
401 if (ctx->err)
402 UCI_THROW(ctx, ctx->err);
403 return 0;
404 }
405
406 int uci_save(struct uci_context *ctx, struct uci_package *p)
407 {
408 FILE *f = NULL;
409 char *filename = NULL;
410 struct uci_element *e, *tmp;
411 struct stat statbuf;
412
413 UCI_HANDLE_ERR(ctx);
414 UCI_ASSERT(ctx, p != NULL);
415
416 /*
417 * if the config file was outside of the /etc/config path,
418 * don't save the delta to a file, update the real file
419 * directly.
420 * does not modify the uci_package pointer
421 */
422 if (!p->has_delta)
423 return uci_commit(ctx, &p, false);
424
425 if (uci_list_empty(&p->delta))
426 return 0;
427
428 if (stat(ctx->savedir, &statbuf) < 0)
429 mkdir(ctx->savedir, UCI_DIRMODE);
430 else if ((statbuf.st_mode & S_IFMT) != S_IFDIR)
431 UCI_THROW(ctx, UCI_ERR_IO);
432
433 if ((asprintf(&filename, "%s/%s", ctx->savedir, p->e.name) < 0) || !filename)
434 UCI_THROW(ctx, UCI_ERR_MEM);
435
436 uci_foreach_element(&ctx->hooks, tmp) {
437 struct uci_hook *hook = uci_to_hook(tmp);
438
439 if (!hook->ops->set)
440 continue;
441
442 uci_foreach_element(&p->delta, e) {
443 hook->ops->set(hook->ops, p, uci_to_delta(e));
444 }
445 }
446
447 ctx->err = 0;
448 UCI_TRAP_SAVE(ctx, done);
449 f = uci_open_stream(ctx, filename, SEEK_END, true, true);
450 UCI_TRAP_RESTORE(ctx);
451
452 uci_foreach_element_safe(&p->delta, tmp, e) {
453 struct uci_delta *h = uci_to_delta(e);
454 char *prefix = "";
455
456 switch(h->cmd) {
457 case UCI_CMD_REMOVE:
458 prefix = "-";
459 break;
460 case UCI_CMD_RENAME:
461 prefix = "@";
462 break;
463 case UCI_CMD_ADD:
464 prefix = "+";
465 break;
466 case UCI_CMD_REORDER:
467 prefix = "^";
468 break;
469 case UCI_CMD_LIST_ADD:
470 prefix = "|";
471 break;
472 case UCI_CMD_LIST_DEL:
473 prefix = "_";
474 break;
475 default:
476 break;
477 }
478
479 fprintf(f, "%s%s.%s", prefix, p->e.name, h->section);
480 if (e->name)
481 fprintf(f, ".%s", e->name);
482
483 if (h->cmd == UCI_CMD_REMOVE && !h->value)
484 fprintf(f, "\n");
485 else
486 fprintf(f, "=%s\n", h->value);
487 uci_free_delta(h);
488 }
489
490 done:
491 uci_close_stream(f);
492 if (filename)
493 free(filename);
494 if (ctx->err)
495 UCI_THROW(ctx, ctx->err);
496
497 return 0;
498 }
499
500