fix wrong buffer allocation
[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 void uci_parse_history_tuple(struct uci_context *ctx, char **buf, char **package, char **section, char **option, char **value, int *cmd)
92 {
93 int c = UCI_CMD_CHANGE;
94
95 switch(**buf) {
96 case '-':
97 c = UCI_CMD_REMOVE;
98 break;
99 case '@':
100 c = UCI_CMD_RENAME;
101 break;
102 case '+':
103 /* UCI_CMD_ADD is used for anonymous sections or list values */
104 c = UCI_CMD_ADD;
105 break;
106 case '|':
107 c = UCI_CMD_LIST_ADD;
108 break;
109 }
110
111 if (c != UCI_CMD_CHANGE)
112 *buf += 1;
113
114 if (cmd)
115 *cmd = c;
116
117 UCI_INTERNAL(uci_parse_tuple, ctx, *buf, package, section, option, value);
118 if (!*section[0])
119 UCI_THROW(ctx, UCI_ERR_PARSE);
120
121 }
122
123 static void uci_parse_history_line(struct uci_context *ctx, struct uci_package *p, char *buf)
124 {
125 struct uci_element *e = NULL;
126 bool delete = false;
127 bool rename = false;
128 char *package = NULL;
129 char *section = NULL;
130 char *option = NULL;
131 char *value = NULL;
132 int cmd;
133
134 uci_parse_history_tuple(ctx, &buf, &package, &section, &option, &value, &cmd);
135 if (!package || (strcmp(package, p->e.name) != 0))
136 goto error;
137 if (!uci_validate_name(section))
138 goto error;
139 if (option && !uci_validate_name(option))
140 goto error;
141 if (rename && !uci_validate_str(value, (option || delete)))
142 goto error;
143
144 if (ctx->flags & UCI_FLAG_SAVED_HISTORY)
145 uci_add_history(ctx, &p->saved_history, cmd, section, option, value);
146
147 switch(cmd) {
148 case UCI_CMD_RENAME:
149 UCI_INTERNAL(uci_rename, ctx, p, section, option, value);
150 break;
151 case UCI_CMD_REMOVE:
152 UCI_INTERNAL(uci_delete, ctx, p, section, option);
153 break;
154 case UCI_CMD_LIST_ADD:
155 UCI_INTERNAL(uci_add_list, ctx, p, section, option, value, NULL);
156 break;
157 case UCI_CMD_ADD:
158 case UCI_CMD_CHANGE:
159 UCI_INTERNAL(uci_set, ctx, p, section, option, value, &e);
160 if (!option && e && (cmd == UCI_CMD_ADD))
161 uci_to_section(e)->anonymous = true;
162 break;
163 }
164 return;
165 error:
166 UCI_THROW(ctx, UCI_ERR_PARSE);
167 }
168
169 /* returns the number of changes that were successfully parsed */
170 static int uci_parse_history(struct uci_context *ctx, FILE *stream, struct uci_package *p)
171 {
172 struct uci_parse_context *pctx;
173 int changes = 0;
174
175 /* make sure no memory from previous parse attempts is leaked */
176 uci_cleanup(ctx);
177
178 pctx = (struct uci_parse_context *) uci_malloc(ctx, sizeof(struct uci_parse_context));
179 ctx->pctx = pctx;
180 pctx->file = stream;
181
182 while (!feof(pctx->file)) {
183 uci_getln(ctx, 0);
184 if (!pctx->buf[0])
185 continue;
186
187 /*
188 * ignore parse errors in single lines, we want to preserve as much
189 * history as possible
190 */
191 UCI_TRAP_SAVE(ctx, error);
192 uci_parse_history_line(ctx, p, pctx->buf);
193 UCI_TRAP_RESTORE(ctx);
194 changes++;
195 error:
196 continue;
197 }
198
199 /* no error happened, we can get rid of the parser context now */
200 uci_cleanup(ctx);
201 return changes;
202 }
203
204 /* returns the number of changes that were successfully parsed */
205 static int uci_load_history_file(struct uci_context *ctx, struct uci_package *p, char *filename, FILE **f, bool flush)
206 {
207 FILE *stream = NULL;
208 int changes = 0;
209
210 UCI_TRAP_SAVE(ctx, done);
211 stream = uci_open_stream(ctx, filename, SEEK_SET, flush, false);
212 if (p)
213 changes = uci_parse_history(ctx, stream, p);
214 UCI_TRAP_RESTORE(ctx);
215 done:
216 if (f)
217 *f = stream;
218 else if (stream)
219 uci_close_stream(stream);
220 return changes;
221 }
222
223 /* returns the number of changes that were successfully parsed */
224 static int uci_load_history(struct uci_context *ctx, struct uci_package *p, bool flush)
225 {
226 struct uci_element *e;
227 char *filename = NULL;
228 FILE *f = NULL;
229 int changes = 0;
230
231 if (!p->has_history)
232 return 0;
233
234 uci_foreach_element(&ctx->history_path, e) {
235 if ((asprintf(&filename, "%s/%s", e->name, p->e.name) < 0) || !filename)
236 UCI_THROW(ctx, UCI_ERR_MEM);
237
238 uci_load_history_file(ctx, p, filename, NULL, false);
239 free(filename);
240 }
241
242 if ((asprintf(&filename, "%s/%s", ctx->savedir, p->e.name) < 0) || !filename)
243 UCI_THROW(ctx, UCI_ERR_MEM);
244
245 changes = uci_load_history_file(ctx, p, filename, &f, flush);
246 if (flush && f && (changes > 0)) {
247 rewind(f);
248 ftruncate(fileno(f), 0);
249 }
250 if (filename)
251 free(filename);
252 uci_close_stream(f);
253 ctx->err = 0;
254 return changes;
255 }
256
257 static void uci_filter_history(struct uci_context *ctx, const char *name, const char *section, const char *option)
258 {
259 struct uci_parse_context *pctx;
260 struct uci_element *e, *tmp;
261 struct uci_list list;
262 char *filename = NULL;
263 char *p = NULL;
264 char *s = NULL;
265 char *o = NULL;
266 char *v = NULL;
267 FILE *f = NULL;
268
269 uci_list_init(&list);
270 uci_alloc_parse_context(ctx);
271 pctx = ctx->pctx;
272
273 if ((asprintf(&filename, "%s/%s", ctx->savedir, name) < 0) || !filename)
274 UCI_THROW(ctx, UCI_ERR_MEM);
275
276 UCI_TRAP_SAVE(ctx, done);
277 f = uci_open_stream(ctx, filename, SEEK_SET, true, false);
278 pctx->file = f;
279 while (!feof(f)) {
280 struct uci_element *e;
281 char *buf;
282
283 uci_getln(ctx, 0);
284 buf = pctx->buf;
285 if (!buf[0])
286 continue;
287
288 /* NB: need to allocate the element before the call to
289 * uci_parse_history_tuple, otherwise the original string
290 * gets modified before it is saved */
291 e = uci_alloc_generic(ctx, UCI_TYPE_HISTORY, pctx->buf, sizeof(struct uci_element));
292 uci_list_add(&list, &e->list);
293
294 uci_parse_history_tuple(ctx, &buf, &p, &s, &o, &v, NULL);
295 if (section) {
296 if (!s || (strcmp(section, s) != 0))
297 continue;
298 }
299 if (option) {
300 if (!o || (strcmp(option, o) != 0))
301 continue;
302 }
303 /* match, drop this element again */
304 uci_free_element(e);
305 }
306
307 /* rebuild the history file */
308 rewind(f);
309 ftruncate(fileno(f), 0);
310 uci_foreach_element_safe(&list, tmp, e) {
311 fprintf(f, "%s\n", e->name);
312 uci_free_element(e);
313 }
314 UCI_TRAP_RESTORE(ctx);
315
316 done:
317 if (filename)
318 free(filename);
319 uci_close_stream(f);
320 uci_foreach_element_safe(&list, tmp, e) {
321 uci_free_element(e);
322 }
323 uci_cleanup(ctx);
324 }
325
326 int uci_revert(struct uci_context *ctx, struct uci_package **pkg, const char *section, const char *option)
327 {
328 struct uci_package *p;
329 char *name = NULL;
330
331 UCI_HANDLE_ERR(ctx);
332 UCI_ASSERT(ctx, pkg != NULL);
333 p = *pkg;
334 UCI_ASSERT(ctx, p != NULL);
335 UCI_ASSERT(ctx, p->has_history);
336
337 /*
338 * - flush unwritten changes
339 * - save the package name
340 * - unload the package
341 * - filter the history
342 * - reload the package
343 */
344 UCI_TRAP_SAVE(ctx, error);
345 UCI_INTERNAL(uci_save, ctx, p);
346 name = uci_strdup(ctx, p->e.name);
347
348 *pkg = NULL;
349 uci_free_package(&p);
350 uci_filter_history(ctx, name, section, option);
351
352 UCI_INTERNAL(uci_load, ctx, name, &p);
353 UCI_TRAP_RESTORE(ctx);
354 ctx->err = 0;
355
356 error:
357 if (name)
358 free(name);
359 if (ctx->err)
360 UCI_THROW(ctx, ctx->err);
361 return 0;
362 }
363
364 int uci_save(struct uci_context *ctx, struct uci_package *p)
365 {
366 FILE *f = NULL;
367 char *filename = NULL;
368 struct uci_element *e, *tmp;
369 struct stat statbuf;
370
371 UCI_HANDLE_ERR(ctx);
372 UCI_ASSERT(ctx, p != NULL);
373
374 /*
375 * if the config file was outside of the /etc/config path,
376 * don't save the history to a file, update the real file
377 * directly.
378 * does not modify the uci_package pointer
379 */
380 if (!p->has_history)
381 return uci_commit(ctx, &p, false);
382
383 if (uci_list_empty(&p->history))
384 return 0;
385
386 if (stat(ctx->savedir, &statbuf) < 0)
387 mkdir(ctx->savedir, UCI_DIRMODE);
388 else if ((statbuf.st_mode & S_IFMT) != S_IFDIR)
389 UCI_THROW(ctx, UCI_ERR_IO);
390
391 if ((asprintf(&filename, "%s/%s", ctx->savedir, p->e.name) < 0) || !filename)
392 UCI_THROW(ctx, UCI_ERR_MEM);
393
394 ctx->err = 0;
395 UCI_TRAP_SAVE(ctx, done);
396 f = uci_open_stream(ctx, filename, SEEK_END, true, true);
397 UCI_TRAP_RESTORE(ctx);
398
399 uci_foreach_element_safe(&p->history, tmp, e) {
400 struct uci_history *h = uci_to_history(e);
401 char *prefix = "";
402
403 switch(h->cmd) {
404 case UCI_CMD_REMOVE:
405 prefix = "-";
406 break;
407 case UCI_CMD_RENAME:
408 prefix = "@";
409 break;
410 case UCI_CMD_ADD:
411 prefix = "+";
412 break;
413 case UCI_CMD_LIST_ADD:
414 prefix = "|";
415 break;
416 default:
417 break;
418 }
419
420 fprintf(f, "%s%s.%s", prefix, p->e.name, h->section);
421 if (e->name)
422 fprintf(f, ".%s", e->name);
423
424 if (h->cmd == UCI_CMD_REMOVE)
425 fprintf(f, "\n");
426 else
427 fprintf(f, "=%s\n", h->value);
428 uci_free_history(h);
429 }
430
431 done:
432 uci_close_stream(f);
433 if (filename)
434 free(filename);
435 if (ctx->err)
436 UCI_THROW(ctx, ctx->err);
437
438 return 0;
439 }
440
441