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