move history code into history.c
[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 /*
29 * Clean up all extra memory used by the parser and exporter
30 */
31 static void uci_file_cleanup(struct uci_context *ctx)
32 {
33 struct uci_parse_context *pctx;
34
35 if (ctx->buf) {
36 free(ctx->buf);
37 ctx->buf = NULL;
38 ctx->bufsz = 0;
39 }
40
41 pctx = ctx->pctx;
42 if (!pctx)
43 return;
44
45 ctx->pctx = NULL;
46 if (pctx->package)
47 uci_free_package(&pctx->package);
48
49 if (pctx->buf)
50 free(pctx->buf);
51
52 free(pctx);
53 }
54
55
56 /*
57 * parse a character escaped by '\'
58 * returns true if the escaped character is to be parsed
59 * returns false if the escaped character is to be ignored
60 */
61 static inline bool parse_backslash(struct uci_context *ctx, char **str)
62 {
63 /* skip backslash */
64 *str += 1;
65
66 /* undecoded backslash at the end of line, fetch the next line */
67 if (!**str) {
68 *str += 1;
69 uci_getln(ctx, *str - ctx->pctx->buf);
70 return false;
71 }
72
73 /* FIXME: decode escaped char, necessary? */
74 return true;
75 }
76
77 /*
78 * move the string pointer forward until a non-whitespace character or
79 * EOL is reached
80 */
81 static void skip_whitespace(struct uci_context *ctx, char **str)
82 {
83 restart:
84 while (**str && isspace(**str))
85 *str += 1;
86
87 if (**str == '\\') {
88 if (!parse_backslash(ctx, str))
89 goto restart;
90 }
91 }
92
93 static inline void addc(char **dest, char **src)
94 {
95 **dest = **src;
96 *dest += 1;
97 *src += 1;
98 }
99
100 /*
101 * parse a double quoted string argument from the command line
102 */
103 static void parse_double_quote(struct uci_context *ctx, char **str, char **target)
104 {
105 char c;
106
107 /* skip quote character */
108 *str += 1;
109
110 while ((c = **str)) {
111 switch(c) {
112 case '"':
113 **target = 0;
114 *str += 1;
115 return;
116 case '\\':
117 if (!parse_backslash(ctx, str))
118 continue;
119 /* fall through */
120 default:
121 addc(target, str);
122 break;
123 }
124 }
125 uci_parse_error(ctx, *str, "unterminated \"");
126 }
127
128 /*
129 * parse a single quoted string argument from the command line
130 */
131 static void parse_single_quote(struct uci_context *ctx, char **str, char **target)
132 {
133 char c;
134 /* skip quote character */
135 *str += 1;
136
137 while ((c = **str)) {
138 switch(c) {
139 case '\'':
140 **target = 0;
141 *str += 1;
142 return;
143 default:
144 addc(target, str);
145 }
146 }
147 uci_parse_error(ctx, *str, "unterminated '");
148 }
149
150 /*
151 * parse a string from the command line and detect the quoting style
152 */
153 static void parse_str(struct uci_context *ctx, char **str, char **target)
154 {
155 do {
156 switch(**str) {
157 case '\'':
158 parse_single_quote(ctx, str, target);
159 break;
160 case '"':
161 parse_double_quote(ctx, str, target);
162 break;
163 case '#':
164 **str = 0;
165 /* fall through */
166 case 0:
167 goto done;
168 case '\\':
169 if (!parse_backslash(ctx, str))
170 continue;
171 /* fall through */
172 default:
173 addc(target, str);
174 break;
175 }
176 } while (**str && !isspace(**str));
177 done:
178
179 /*
180 * if the string was unquoted and we've stopped at a whitespace
181 * character, skip to the next one, because the whitespace will
182 * be overwritten by a null byte here
183 */
184 if (**str)
185 *str += 1;
186
187 /* terminate the parsed string */
188 **target = 0;
189 }
190
191 /*
192 * extract the next argument from the command line
193 */
194 static char *next_arg(struct uci_context *ctx, char **str, bool required, bool name)
195 {
196 char *val;
197 char *ptr;
198
199 val = ptr = *str;
200 skip_whitespace(ctx, str);
201 parse_str(ctx, str, &ptr);
202 if (!*val) {
203 if (required)
204 uci_parse_error(ctx, *str, "insufficient arguments");
205 goto done;
206 }
207
208 if (name && !uci_validate_name(val))
209 uci_parse_error(ctx, val, "invalid character in field");
210
211 done:
212 return val;
213 }
214
215 /*
216 * verify that the end of the line or command is reached.
217 * throw an error if extra arguments are given on the command line
218 */
219 static void assert_eol(struct uci_context *ctx, char **str)
220 {
221 char *tmp;
222
223 tmp = next_arg(ctx, str, false, false);
224 if (tmp && *tmp && (ctx->flags & UCI_FLAG_STRICT))
225 uci_parse_error(ctx, *str, "too many arguments");
226 }
227
228 /*
229 * switch to a different config, either triggered by uci_load, or by a
230 * 'package <...>' statement in the import file
231 */
232 static void uci_switch_config(struct uci_context *ctx)
233 {
234 struct uci_parse_context *pctx;
235 struct uci_element *e;
236 const char *name;
237
238 pctx = ctx->pctx;
239 name = pctx->name;
240
241 /* add the last config to main config file list */
242 if (pctx->package) {
243 uci_list_add(&ctx->root, &pctx->package->e.list);
244
245 pctx->package = NULL;
246 pctx->section = NULL;
247 }
248
249 if (!name)
250 return;
251
252 /*
253 * if an older config under the same name exists, unload it
254 * ignore errors here, e.g. if the config was not found
255 */
256 e = uci_lookup_list(ctx, &ctx->root, name);
257 if (e)
258 UCI_THROW(ctx, UCI_ERR_DUPLICATE);
259 pctx->package = uci_alloc_package(ctx, name);
260 }
261
262 /*
263 * parse the 'package' uci command (next config package)
264 */
265 static void uci_parse_package(struct uci_context *ctx, char **str, bool single)
266 {
267 char *name = NULL;
268
269 /* command string null-terminated by strtok */
270 *str += strlen(*str) + 1;
271
272 name = next_arg(ctx, str, true, true);
273 assert_eol(ctx, str);
274 if (single)
275 return;
276
277 ctx->pctx->name = name;
278 uci_switch_config(ctx);
279 }
280
281 /* Based on an efficient hash function published by D. J. Bernstein */
282 static unsigned int djbhash(unsigned int hash, char *str)
283 {
284 int len = strlen(str);
285 int i;
286
287 /* initial value */
288 if (hash == ~0)
289 hash = 5381;
290
291 for(i = 0; i < len; i++) {
292 hash = ((hash << 5) + hash) + str[i];
293 }
294 return (hash & 0x7FFFFFFF);
295 }
296
297 /* fix up an unnamed section */
298 static void uci_fixup_section(struct uci_context *ctx, struct uci_section *s)
299 {
300 unsigned int hash = ~0;
301 struct uci_element *e;
302 char buf[16];
303
304 if (!s || s->e.name)
305 return;
306
307 /*
308 * Generate a name for unnamed sections. This is used as reference
309 * when locating or updating the section from apps/scripts.
310 * To make multiple concurrent versions somewhat safe for updating,
311 * the name is generated from a hash of its type and name/value
312 * pairs of its option, and it is prefixed by a counter value.
313 * If the order of the unnamed sections changes for some reason,
314 * updates to them will be rejected.
315 */
316 hash = djbhash(hash, s->type);
317 uci_foreach_element(&s->options, e) {
318 hash = djbhash(hash, e->name);
319 hash = djbhash(hash, uci_to_option(e)->value);
320 }
321 sprintf(buf, "cfg%02x%04x", ++s->package->n_section, hash % (1 << 16));
322 s->e.name = uci_strdup(ctx, buf);
323 }
324
325 /*
326 * parse the 'config' uci command (open a section)
327 */
328 static void uci_parse_config(struct uci_context *ctx, char **str)
329 {
330 struct uci_parse_context *pctx = ctx->pctx;
331 char *name = NULL;
332 char *type = NULL;
333
334 uci_fixup_section(ctx, ctx->pctx->section);
335 if (!ctx->pctx->package) {
336 if (!ctx->pctx->name)
337 uci_parse_error(ctx, *str, "attempting to import a file without a package name");
338
339 uci_switch_config(ctx);
340 }
341
342 /* command string null-terminated by strtok */
343 *str += strlen(*str) + 1;
344
345 type = next_arg(ctx, str, true, true);
346 name = next_arg(ctx, str, false, true);
347 assert_eol(ctx, str);
348
349 if (pctx->merge) {
350 UCI_TRAP_SAVE(ctx, error);
351 uci_set(ctx, pctx->package, name, NULL, type);
352 UCI_TRAP_RESTORE(ctx);
353 return;
354 error:
355 UCI_THROW(ctx, ctx->errno);
356 } else
357 pctx->section = uci_alloc_section(pctx->package, type, name);
358 }
359
360 /*
361 * parse the 'option' uci command (open a value)
362 */
363 static void uci_parse_option(struct uci_context *ctx, char **str)
364 {
365 struct uci_parse_context *pctx = ctx->pctx;
366 char *name = NULL;
367 char *value = NULL;
368
369 if (!pctx->section)
370 uci_parse_error(ctx, *str, "option command found before the first section");
371
372 /* command string null-terminated by strtok */
373 *str += strlen(*str) + 1;
374
375 name = next_arg(ctx, str, true, true);
376 value = next_arg(ctx, str, true, false);
377 assert_eol(ctx, str);
378
379 if (pctx->merge) {
380 UCI_TRAP_SAVE(ctx, error);
381 uci_set(ctx, pctx->package, pctx->section->e.name, name, value);
382 UCI_TRAP_RESTORE(ctx);
383 return;
384 error:
385 UCI_THROW(ctx, ctx->errno);
386 } else
387 uci_alloc_option(pctx->section, name, value);
388 }
389
390
391 /*
392 * parse a complete input line, split up combined commands by ';'
393 */
394 static void uci_parse_line(struct uci_context *ctx, bool single)
395 {
396 struct uci_parse_context *pctx = ctx->pctx;
397 char *word, *brk = NULL;
398
399 for (word = strtok_r(pctx->buf, ";", &brk);
400 word;
401 word = strtok_r(NULL, ";", &brk)) {
402
403 char *pbrk = NULL;
404 word = strtok_r(word, " \t", &pbrk);
405
406 if (!word)
407 continue;
408
409 switch(word[0]) {
410 case '#':
411 return;
412 case 'p':
413 if ((word[1] == 0) || !strcmp(word + 1, "ackage"))
414 uci_parse_package(ctx, &word, single);
415 break;
416 case 'c':
417 if ((word[1] == 0) || !strcmp(word + 1, "onfig"))
418 uci_parse_config(ctx, &word);
419 break;
420 case 'o':
421 if ((word[1] == 0) || !strcmp(word + 1, "ption"))
422 uci_parse_option(ctx, &word);
423 break;
424 default:
425 uci_parse_error(ctx, word, "unterminated command");
426 break;
427 }
428 }
429 }
430
431 /* max number of characters that escaping adds to the string */
432 #define UCI_QUOTE_ESCAPE "'\\''"
433
434 /*
435 * escape an uci string for export
436 */
437 static char *uci_escape(struct uci_context *ctx, char *str)
438 {
439 char *s, *p;
440 int pos = 0;
441
442 if (!ctx->buf) {
443 ctx->bufsz = LINEBUF;
444 ctx->buf = malloc(LINEBUF);
445 }
446
447 s = str;
448 p = strchr(str, '\'');
449 if (!p)
450 return str;
451
452 do {
453 int len = p - s;
454 if (len > 0) {
455 if (p + sizeof(UCI_QUOTE_ESCAPE) - str >= ctx->bufsz) {
456 ctx->bufsz *= 2;
457 ctx->buf = realloc(ctx->buf, ctx->bufsz);
458 if (!ctx->buf)
459 UCI_THROW(ctx, UCI_ERR_MEM);
460 }
461 memcpy(&ctx->buf[pos], s, len);
462 pos += len;
463 }
464 strcpy(&ctx->buf[pos], UCI_QUOTE_ESCAPE);
465 pos += sizeof(UCI_QUOTE_ESCAPE);
466 s = p + 1;
467 } while ((p = strchr(s, '\'')));
468
469 return ctx->buf;
470 }
471
472
473 /*
474 * export a single config package to a file stream
475 */
476 static void uci_export_package(struct uci_package *p, FILE *stream, bool header)
477 {
478 struct uci_context *ctx = p->ctx;
479 struct uci_element *s, *o;
480
481 if (header)
482 fprintf(stream, "package '%s'\n", uci_escape(ctx, p->e.name));
483 uci_foreach_element(&p->sections, s) {
484 struct uci_section *sec = uci_to_section(s);
485 fprintf(stream, "\nconfig '%s'", uci_escape(ctx, sec->type));
486 if (!sec->anonymous || (ctx->flags & UCI_FLAG_EXPORT_NAME))
487 fprintf(stream, " '%s'", uci_escape(ctx, sec->e.name));
488 fprintf(stream, "\n");
489 uci_foreach_element(&sec->options, o) {
490 struct uci_option *opt = uci_to_option(o);
491 fprintf(stream, "\toption '%s'", uci_escape(ctx, opt->e.name));
492 fprintf(stream, " '%s'\n", uci_escape(ctx, opt->value));
493 }
494 }
495 fprintf(stream, "\n");
496 }
497
498 int uci_export(struct uci_context *ctx, FILE *stream, struct uci_package *package, bool header)
499 {
500 struct uci_element *e;
501
502 UCI_HANDLE_ERR(ctx);
503 UCI_ASSERT(ctx, stream != NULL);
504
505 if (package)
506 uci_export_package(package, stream, header);
507 else {
508 uci_foreach_element(&ctx->root, e) {
509 uci_export_package(uci_to_package(e), stream, header);
510 }
511 }
512
513 return 0;
514 }
515
516 int uci_import(struct uci_context *ctx, FILE *stream, const char *name, struct uci_package **package, bool single)
517 {
518 struct uci_parse_context *pctx;
519 UCI_HANDLE_ERR(ctx);
520
521 /* make sure no memory from previous parse attempts is leaked */
522 uci_file_cleanup(ctx);
523
524 pctx = (struct uci_parse_context *) uci_malloc(ctx, sizeof(struct uci_parse_context));
525 ctx->pctx = pctx;
526 pctx->file = stream;
527 if (*package && single) {
528 pctx->package = *package;
529 pctx->merge = true;
530 }
531
532 /*
533 * If 'name' was supplied, assume that the supplied stream does not contain
534 * the appropriate 'package <name>' string to specify the config name
535 * NB: the config file can still override the package name
536 */
537 if (name) {
538 UCI_ASSERT(ctx, uci_validate_name(name));
539 pctx->name = name;
540 }
541
542 while (!feof(pctx->file)) {
543 uci_getln(ctx, 0);
544 UCI_TRAP_SAVE(ctx, error);
545 if (pctx->buf[0])
546 uci_parse_line(ctx, single);
547 UCI_TRAP_RESTORE(ctx);
548 continue;
549 error:
550 if (ctx->flags & UCI_FLAG_PERROR)
551 uci_perror(ctx, NULL);
552 if ((ctx->errno != UCI_ERR_PARSE) ||
553 (ctx->flags & UCI_FLAG_STRICT))
554 UCI_THROW(ctx, ctx->errno);
555 }
556
557 uci_fixup_section(ctx, ctx->pctx->section);
558 if (package)
559 *package = pctx->package;
560 if (pctx->merge)
561 pctx->package = NULL;
562
563 pctx->name = NULL;
564 uci_switch_config(ctx);
565
566 /* no error happened, we can get rid of the parser context now */
567 uci_file_cleanup(ctx);
568
569 return 0;
570 }
571
572
573 static char *uci_config_path(struct uci_context *ctx, const char *name)
574 {
575 char *filename;
576
577 UCI_ASSERT(ctx, uci_validate_name(name));
578 filename = uci_malloc(ctx, strlen(name) + strlen(ctx->confdir) + 2);
579 sprintf(filename, "%s/%s", ctx->confdir, name);
580
581 return filename;
582 }
583
584 int uci_load(struct uci_context *ctx, const char *name, struct uci_package **package)
585 {
586 char *filename;
587 bool confdir;
588 FILE *file = NULL;
589
590 UCI_HANDLE_ERR(ctx);
591
592 switch (name[0]) {
593 case '.':
594 /* relative path outside of /etc/config */
595 if (name[1] != '/')
596 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
597 /* fall through */
598 case '/':
599 /* absolute path outside of /etc/config */
600 filename = uci_strdup(ctx, name);
601 name = strrchr(name, '/') + 1;
602 confdir = false;
603 break;
604 default:
605 /* config in /etc/config */
606 filename = uci_config_path(ctx, name);
607 confdir = true;
608 break;
609 }
610
611 file = uci_open_stream(ctx, filename, SEEK_SET, false, false);
612 ctx->errno = 0;
613 UCI_TRAP_SAVE(ctx, done);
614 UCI_INTERNAL(uci_import, ctx, file, name, package, true);
615 UCI_TRAP_RESTORE(ctx);
616
617 if (*package) {
618 (*package)->path = filename;
619 (*package)->confdir = confdir;
620 uci_load_history(ctx, *package, false);
621 }
622
623 done:
624 uci_close_stream(file);
625 return ctx->errno;
626 }
627
628 int uci_commit(struct uci_context *ctx, struct uci_package **package, bool overwrite)
629 {
630 struct uci_package *p;
631 FILE *f = NULL;
632 char *name = NULL;
633 char *path = NULL;
634
635 UCI_HANDLE_ERR(ctx);
636 UCI_ASSERT(ctx, package != NULL);
637 p = *package;
638
639 UCI_ASSERT(ctx, p != NULL);
640 if (!p->path) {
641 if (overwrite)
642 p->path = uci_config_path(ctx, p->e.name);
643 else
644 UCI_THROW(ctx, UCI_ERR_INVAL);
645 }
646
647
648 /* open the config file for writing now, so that it is locked */
649 f = uci_open_stream(ctx, p->path, SEEK_SET, true, true);
650
651 /* flush unsaved changes and reload from history file */
652 UCI_TRAP_SAVE(ctx, done);
653 if (p->confdir) {
654 if (!overwrite) {
655 name = uci_strdup(ctx, p->e.name);
656 path = uci_strdup(ctx, p->path);
657 /* dump our own changes to the history file */
658 if (!uci_list_empty(&p->history))
659 UCI_INTERNAL(uci_save, ctx, p);
660
661 /*
662 * other processes might have modified the config
663 * as well. dump and reload
664 */
665 uci_free_package(&p);
666 uci_file_cleanup(ctx);
667 UCI_INTERNAL(uci_import, ctx, f, name, &p, true);
668
669 p->path = path;
670 p->confdir = true;
671 *package = p;
672
673 /* freed together with the uci_package */
674 path = NULL;
675
676 /* check for updated history, just in case */
677 uci_load_history(ctx, p, true);
678 } else {
679 /* flush history */
680 uci_load_history(ctx, NULL, true);
681 }
682 }
683
684 rewind(f);
685 ftruncate(fileno(f), 0);
686
687 uci_export(ctx, f, p, false);
688 UCI_TRAP_RESTORE(ctx);
689
690 done:
691 if (name)
692 free(name);
693 if (path)
694 free(path);
695 uci_close_stream(f);
696 if (ctx->errno)
697 UCI_THROW(ctx, ctx->errno);
698
699 return 0;
700 }
701
702
703 /*
704 * This function returns the filename by returning the string
705 * after the last '/' character. By checking for a non-'\0'
706 * character afterwards, directories are ignored (glob marks
707 * those with a trailing '/'
708 */
709 static inline char *get_filename(char *path)
710 {
711 char *p;
712
713 p = strrchr(path, '/');
714 p++;
715 if (!*p)
716 return NULL;
717 return p;
718 }
719
720 int uci_list_configs(struct uci_context *ctx, char ***list)
721 {
722 char **configs;
723 glob_t globbuf;
724 int size, i;
725 char *buf;
726 char *dir;
727
728 UCI_HANDLE_ERR(ctx);
729
730 dir = uci_malloc(ctx, strlen(ctx->confdir) + 1 + sizeof("/*"));
731 sprintf(dir, "%s/*", ctx->confdir);
732 if (glob(dir, GLOB_MARK, NULL, &globbuf) != 0)
733 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
734
735 size = sizeof(char *) * (globbuf.gl_pathc + 1);
736 for(i = 0; i < globbuf.gl_pathc; i++) {
737 char *p;
738
739 p = get_filename(globbuf.gl_pathv[i]);
740 if (!p)
741 continue;
742
743 size += strlen(p) + 1;
744 }
745
746 configs = uci_malloc(ctx, size);
747 buf = (char *) &configs[globbuf.gl_pathc + 1];
748 for(i = 0; i < globbuf.gl_pathc; i++) {
749 char *p;
750
751 p = get_filename(globbuf.gl_pathv[i]);
752 if (!p)
753 continue;
754
755 configs[i] = buf;
756 strcpy(buf, p);
757 buf += strlen(buf) + 1;
758 }
759 *list = configs;
760 free(dir);
761
762 return 0;
763 }
764