parser: fix precedence of quoting over ; as command terminator, thx to netprince...
[project/uci.git] / file.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 parsing uci config files
17 */
18
19 #define _GNU_SOURCE
20 #include <sys/types.h>
21 #include <sys/file.h>
22 #include <stdbool.h>
23 #include <unistd.h>
24 #include <fcntl.h>
25 #include <stdio.h>
26 #include <ctype.h>
27
28 static struct uci_backend uci_file_backend;
29
30 /*
31 * verify that the end of the line or command is reached.
32 * throw an error if extra arguments are given on the command line
33 */
34 static void assert_eol(struct uci_context *ctx, char **str)
35 {
36 char *tmp;
37
38 skip_whitespace(ctx, str);
39 tmp = next_arg(ctx, str, false, false);
40 if (*tmp && (ctx->flags & UCI_FLAG_STRICT))
41 uci_parse_error(ctx, *str, "too many arguments");
42 }
43
44 /*
45 * switch to a different config, either triggered by uci_load, or by a
46 * 'package <...>' statement in the import file
47 */
48 static void uci_switch_config(struct uci_context *ctx)
49 {
50 struct uci_parse_context *pctx;
51 struct uci_element *e;
52 const char *name;
53
54 pctx = ctx->pctx;
55 name = pctx->name;
56
57 /* add the last config to main config file list */
58 if (pctx->package) {
59 pctx->package->backend = ctx->backend;
60 uci_list_add(&ctx->root, &pctx->package->e.list);
61
62 pctx->package = NULL;
63 pctx->section = NULL;
64 }
65
66 if (!name)
67 return;
68
69 /*
70 * if an older config under the same name exists, unload it
71 * ignore errors here, e.g. if the config was not found
72 */
73 e = uci_lookup_list(&ctx->root, name);
74 if (e)
75 UCI_THROW(ctx, UCI_ERR_DUPLICATE);
76 pctx->package = uci_alloc_package(ctx, name);
77 }
78
79 /*
80 * parse the 'package' uci command (next config package)
81 */
82 static void uci_parse_package(struct uci_context *ctx, char **str, bool single)
83 {
84 char *name = NULL;
85
86 /* command string null-terminated by strtok */
87 *str += strlen(*str) + 1;
88
89 name = next_arg(ctx, str, true, true);
90 assert_eol(ctx, str);
91 if (single)
92 return;
93
94 ctx->pctx->name = name;
95 uci_switch_config(ctx);
96 }
97
98 /*
99 * parse the 'config' uci command (open a section)
100 */
101 static void uci_parse_config(struct uci_context *ctx, char **str)
102 {
103 struct uci_parse_context *pctx = ctx->pctx;
104 char *name = NULL;
105 char *type = NULL;
106
107 uci_fixup_section(ctx, ctx->pctx->section);
108 if (!ctx->pctx->package) {
109 if (!ctx->pctx->name)
110 uci_parse_error(ctx, *str, "attempting to import a file without a package name");
111
112 uci_switch_config(ctx);
113 }
114
115 /* command string null-terminated by strtok */
116 *str += strlen(*str) + 1;
117
118 type = next_arg(ctx, str, true, false);
119 if (!uci_validate_str(type, false))
120 uci_parse_error(ctx, type, "invalid character in field");
121 name = next_arg(ctx, str, false, true);
122 assert_eol(ctx, str);
123
124 if (pctx->merge) {
125 UCI_TRAP_SAVE(ctx, error);
126 if (uci_set(ctx, pctx->package, name, NULL, type, NULL) != UCI_OK)
127 goto error;
128 UCI_TRAP_RESTORE(ctx);
129 return;
130 error:
131 UCI_THROW(ctx, ctx->errno);
132 } else
133 pctx->section = uci_alloc_section(pctx->package, type, name);
134 }
135
136 /*
137 * parse the 'option' uci command (open a value)
138 */
139 static void uci_parse_option(struct uci_context *ctx, char **str)
140 {
141 struct uci_parse_context *pctx = ctx->pctx;
142 char *name = NULL;
143 char *value = NULL;
144
145 if (!pctx->section)
146 uci_parse_error(ctx, *str, "option command found before the first section");
147
148 /* command string null-terminated by strtok */
149 *str += strlen(*str) + 1;
150
151 name = next_arg(ctx, str, true, true);
152 value = next_arg(ctx, str, false, false);
153 assert_eol(ctx, str);
154
155 if (pctx->merge) {
156 UCI_TRAP_SAVE(ctx, error);
157 uci_set(ctx, pctx->package, pctx->section->e.name, name, value, NULL);
158 UCI_TRAP_RESTORE(ctx);
159 return;
160 error:
161 UCI_THROW(ctx, ctx->errno);
162 } else
163 uci_alloc_option(pctx->section, name, value);
164 }
165
166
167 /*
168 * parse a complete input line, split up combined commands by ';'
169 */
170 static void uci_parse_line(struct uci_context *ctx, bool single)
171 {
172 struct uci_parse_context *pctx = ctx->pctx;
173 char *word, *brk;
174
175 word = pctx->buf;
176 do {
177 brk = NULL;
178 word = strtok_r(word, " \t", &brk);
179 if (!word)
180 return;
181
182 switch(word[0]) {
183 case 0:
184 case '#':
185 return;
186 case 'p':
187 if ((word[1] == 0) || !strcmp(word + 1, "ackage"))
188 uci_parse_package(ctx, &word, single);
189 break;
190 case 'c':
191 if ((word[1] == 0) || !strcmp(word + 1, "onfig"))
192 uci_parse_config(ctx, &word);
193 break;
194 case 'o':
195 if ((word[1] == 0) || !strcmp(word + 1, "ption"))
196 uci_parse_option(ctx, &word);
197 break;
198 default:
199 uci_parse_error(ctx, word, "unterminated command");
200 break;
201 }
202 } while (1);
203 }
204
205 /* max number of characters that escaping adds to the string */
206 #define UCI_QUOTE_ESCAPE "'\\''"
207
208 /*
209 * escape an uci string for export
210 */
211 static char *uci_escape(struct uci_context *ctx, char *str)
212 {
213 char *s, *p;
214 int pos = 0;
215
216 if (!ctx->buf) {
217 ctx->bufsz = LINEBUF;
218 ctx->buf = malloc(LINEBUF);
219 }
220
221 s = str;
222 p = strchr(str, '\'');
223 if (!p)
224 return str;
225
226 do {
227 int len = p - s;
228 if (len > 0) {
229 if (p + sizeof(UCI_QUOTE_ESCAPE) - str >= ctx->bufsz) {
230 ctx->bufsz *= 2;
231 ctx->buf = realloc(ctx->buf, ctx->bufsz);
232 if (!ctx->buf)
233 UCI_THROW(ctx, UCI_ERR_MEM);
234 }
235 memcpy(&ctx->buf[pos], s, len);
236 pos += len;
237 }
238 strcpy(&ctx->buf[pos], UCI_QUOTE_ESCAPE);
239 pos += sizeof(UCI_QUOTE_ESCAPE);
240 s = p + 1;
241 } while ((p = strchr(s, '\'')));
242
243 return ctx->buf;
244 }
245
246
247 /*
248 * export a single config package to a file stream
249 */
250 static void uci_export_package(struct uci_package *p, FILE *stream, bool header)
251 {
252 struct uci_context *ctx = p->ctx;
253 struct uci_element *s, *o;
254
255 if (header)
256 fprintf(stream, "package '%s'\n", uci_escape(ctx, p->e.name));
257 uci_foreach_element(&p->sections, s) {
258 struct uci_section *sec = uci_to_section(s);
259 fprintf(stream, "\nconfig '%s'", uci_escape(ctx, sec->type));
260 if (!sec->anonymous || (ctx->flags & UCI_FLAG_EXPORT_NAME))
261 fprintf(stream, " '%s'", uci_escape(ctx, sec->e.name));
262 fprintf(stream, "\n");
263 uci_foreach_element(&sec->options, o) {
264 struct uci_option *opt = uci_to_option(o);
265 fprintf(stream, "\toption '%s'", uci_escape(ctx, opt->e.name));
266 fprintf(stream, " '%s'\n", uci_escape(ctx, opt->value));
267 }
268 }
269 fprintf(stream, "\n");
270 }
271
272 int uci_export(struct uci_context *ctx, FILE *stream, struct uci_package *package, bool header)
273 {
274 struct uci_element *e;
275
276 UCI_HANDLE_ERR(ctx);
277 UCI_ASSERT(ctx, stream != NULL);
278
279 if (package)
280 uci_export_package(package, stream, header);
281 else {
282 uci_foreach_element(&ctx->root, e) {
283 uci_export_package(uci_to_package(e), stream, header);
284 }
285 }
286
287 return 0;
288 }
289
290 int uci_import(struct uci_context *ctx, FILE *stream, const char *name, struct uci_package **package, bool single)
291 {
292 struct uci_parse_context *pctx;
293 UCI_HANDLE_ERR(ctx);
294
295 /* make sure no memory from previous parse attempts is leaked */
296 uci_cleanup(ctx);
297
298 uci_alloc_parse_context(ctx);
299 pctx = ctx->pctx;
300 pctx->file = stream;
301 if (*package && single) {
302 pctx->package = *package;
303 pctx->merge = true;
304 }
305
306 /*
307 * If 'name' was supplied, assume that the supplied stream does not contain
308 * the appropriate 'package <name>' string to specify the config name
309 * NB: the config file can still override the package name
310 */
311 if (name) {
312 UCI_ASSERT(ctx, uci_validate_name(name));
313 pctx->name = name;
314 }
315
316 while (!feof(pctx->file)) {
317 uci_getln(ctx, 0);
318 UCI_TRAP_SAVE(ctx, error);
319 if (pctx->buf[0])
320 uci_parse_line(ctx, single);
321 UCI_TRAP_RESTORE(ctx);
322 continue;
323 error:
324 if (ctx->flags & UCI_FLAG_PERROR)
325 uci_perror(ctx, NULL);
326 if ((ctx->errno != UCI_ERR_PARSE) ||
327 (ctx->flags & UCI_FLAG_STRICT))
328 UCI_THROW(ctx, ctx->errno);
329 }
330
331 uci_fixup_section(ctx, ctx->pctx->section);
332 if (!pctx->package && name)
333 uci_switch_config(ctx);
334 if (package)
335 *package = pctx->package;
336 if (pctx->merge)
337 pctx->package = NULL;
338
339 pctx->name = NULL;
340 uci_switch_config(ctx);
341
342 /* no error happened, we can get rid of the parser context now */
343 uci_cleanup(ctx);
344
345 return 0;
346 }
347
348
349 static char *uci_config_path(struct uci_context *ctx, const char *name)
350 {
351 char *filename;
352
353 UCI_ASSERT(ctx, uci_validate_name(name));
354 filename = uci_malloc(ctx, strlen(name) + strlen(ctx->confdir) + 2);
355 sprintf(filename, "%s/%s", ctx->confdir, name);
356
357 return filename;
358 }
359
360 void uci_file_commit(struct uci_context *ctx, struct uci_package **package, bool overwrite)
361 {
362 struct uci_package *p = *package;
363 FILE *f = NULL;
364 char *name = NULL;
365 char *path = NULL;
366
367 if (!p->path) {
368 if (overwrite)
369 p->path = uci_config_path(ctx, p->e.name);
370 else
371 UCI_THROW(ctx, UCI_ERR_INVAL);
372 }
373
374 /* open the config file for writing now, so that it is locked */
375 f = uci_open_stream(ctx, p->path, SEEK_SET, true, true);
376
377 /* flush unsaved changes and reload from history file */
378 UCI_TRAP_SAVE(ctx, done);
379 if (p->has_history) {
380 if (!overwrite) {
381 name = uci_strdup(ctx, p->e.name);
382 path = uci_strdup(ctx, p->path);
383 /* dump our own changes to the history file */
384 if (!uci_list_empty(&p->history))
385 UCI_INTERNAL(uci_save, ctx, p);
386
387 /*
388 * other processes might have modified the config
389 * as well. dump and reload
390 */
391 uci_free_package(&p);
392 uci_cleanup(ctx);
393 UCI_INTERNAL(uci_import, ctx, f, name, &p, true);
394
395 p->path = path;
396 p->has_history = true;
397 *package = p;
398
399 /* freed together with the uci_package */
400 path = NULL;
401
402 /* check for updated history, flush */
403 if (!uci_load_history(ctx, p, true))
404 goto done;
405 } else {
406 /* flush history */
407 if (!uci_load_history(ctx, NULL, true))
408 goto done;
409 }
410 }
411
412 rewind(f);
413 ftruncate(fileno(f), 0);
414
415 uci_export(ctx, f, p, false);
416 UCI_TRAP_RESTORE(ctx);
417
418 done:
419 if (name)
420 free(name);
421 if (path)
422 free(path);
423 uci_close_stream(f);
424 if (ctx->errno)
425 UCI_THROW(ctx, ctx->errno);
426 }
427
428
429 /*
430 * This function returns the filename by returning the string
431 * after the last '/' character. By checking for a non-'\0'
432 * character afterwards, directories are ignored (glob marks
433 * those with a trailing '/'
434 */
435 static inline char *get_filename(char *path)
436 {
437 char *p;
438
439 p = strrchr(path, '/');
440 p++;
441 if (!*p)
442 return NULL;
443 return p;
444 }
445
446 static char **uci_list_config_files(struct uci_context *ctx)
447 {
448 char **configs;
449 glob_t globbuf;
450 int size, i;
451 char *buf;
452 char *dir;
453
454 dir = uci_malloc(ctx, strlen(ctx->confdir) + 1 + sizeof("/*"));
455 sprintf(dir, "%s/*", ctx->confdir);
456 if (glob(dir, GLOB_MARK, NULL, &globbuf) != 0)
457 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
458
459 size = sizeof(char *) * (globbuf.gl_pathc + 1);
460 for(i = 0; i < globbuf.gl_pathc; i++) {
461 char *p;
462
463 p = get_filename(globbuf.gl_pathv[i]);
464 if (!p)
465 continue;
466
467 size += strlen(p) + 1;
468 }
469
470 configs = uci_malloc(ctx, size);
471 buf = (char *) &configs[globbuf.gl_pathc + 1];
472 for(i = 0; i < globbuf.gl_pathc; i++) {
473 char *p;
474
475 p = get_filename(globbuf.gl_pathv[i]);
476 if (!p)
477 continue;
478
479 configs[i] = buf;
480 strcpy(buf, p);
481 buf += strlen(buf) + 1;
482 }
483 free(dir);
484 return configs;
485 }
486
487 static struct uci_package *uci_file_load(struct uci_context *ctx, const char *name)
488 {
489 struct uci_package *package = NULL;
490 char *filename;
491 bool confdir;
492 FILE *file = NULL;
493
494 switch (name[0]) {
495 case '.':
496 /* relative path outside of /etc/config */
497 if (name[1] != '/')
498 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
499 /* fall through */
500 case '/':
501 /* absolute path outside of /etc/config */
502 filename = uci_strdup(ctx, name);
503 name = strrchr(name, '/') + 1;
504 confdir = false;
505 break;
506 default:
507 /* config in /etc/config */
508 filename = uci_config_path(ctx, name);
509 confdir = true;
510 break;
511 }
512
513 file = uci_open_stream(ctx, filename, SEEK_SET, false, false);
514 ctx->errno = 0;
515 UCI_TRAP_SAVE(ctx, done);
516 UCI_INTERNAL(uci_import, ctx, file, name, &package, true);
517 UCI_TRAP_RESTORE(ctx);
518
519 if (package) {
520 package->path = filename;
521 package->has_history = confdir;
522 uci_load_history(ctx, package, false);
523 }
524
525 done:
526 uci_close_stream(file);
527 if (ctx->errno)
528 UCI_THROW(ctx, ctx->errno);
529 return package;
530 }
531
532 static UCI_BACKEND(uci_file_backend, "file",
533 .load = uci_file_load,
534 .commit = uci_file_commit,
535 .list_configs = uci_list_config_files,
536 );