2 * libuci - Library for the Unified Configuration Interface
3 * Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org>
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
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.
16 * This file contains the code for parsing uci config files
19 #include <sys/types.h>
28 #define LINEBUF_MAX 4096
30 static void uci_parse_error(struct uci_context *ctx, char *pos, char *reason)
32 struct uci_parse_context *pctx = ctx->pctx;
34 pctx->reason = reason;
35 pctx->byte = pos - pctx->buf;
36 UCI_THROW(ctx, UCI_ERR_PARSE);
40 * Fetch a new line from the input stream and resize buffer if necessary
42 static void uci_getln(struct uci_context *ctx, int offset)
44 struct uci_parse_context *pctx = ctx->pctx;
48 if (pctx->buf == NULL) {
49 pctx->buf = uci_malloc(ctx, LINEBUF);
50 pctx->bufsz = LINEBUF;
58 p = fgets(p, pctx->bufsz - ofs, pctx->file);
63 if (pctx->buf[ofs - 1] == '\n') {
65 pctx->buf[ofs - 1] = 0;
69 if (pctx->bufsz > LINEBUF_MAX/2)
70 uci_parse_error(ctx, p, "line too long");
73 pctx->buf = uci_realloc(ctx, pctx->buf, pctx->bufsz);
78 * Clean up all extra memory used by the parser and exporter
80 static void uci_file_cleanup(struct uci_context *ctx)
82 struct uci_parse_context *pctx;
96 uci_free_package(&pctx->package);
105 * parse a character escaped by '\'
106 * returns true if the escaped character is to be parsed
107 * returns false if the escaped character is to be ignored
109 static inline bool parse_backslash(struct uci_context *ctx, char **str)
114 /* undecoded backslash at the end of line, fetch the next line */
117 uci_getln(ctx, *str - ctx->pctx->buf);
121 /* FIXME: decode escaped char, necessary? */
126 * move the string pointer forward until a non-whitespace character or
129 static void skip_whitespace(struct uci_context *ctx, char **str)
132 while (**str && isspace(**str))
136 if (!parse_backslash(ctx, str))
141 static inline void addc(char **dest, char **src)
149 * parse a double quoted string argument from the command line
151 static void parse_double_quote(struct uci_context *ctx, char **str, char **target)
155 /* skip quote character */
158 while ((c = **str)) {
165 if (!parse_backslash(ctx, str))
173 uci_parse_error(ctx, *str, "unterminated \"");
177 * parse a single quoted string argument from the command line
179 static void parse_single_quote(struct uci_context *ctx, char **str, char **target)
182 /* skip quote character */
185 while ((c = **str)) {
195 uci_parse_error(ctx, *str, "unterminated '");
199 * parse a string from the command line and detect the quoting style
201 static void parse_str(struct uci_context *ctx, char **str, char **target)
206 parse_single_quote(ctx, str, target);
209 parse_double_quote(ctx, str, target);
214 if (!parse_backslash(ctx, str))
221 } while (**str && !isspace(**str));
225 * if the string was unquoted and we've stopped at a whitespace
226 * character, skip to the next one, because the whitespace will
227 * be overwritten by a null byte here
232 /* terminate the parsed string */
237 * extract the next argument from the command line
239 static char *next_arg(struct uci_context *ctx, char **str, bool required, bool name)
245 skip_whitespace(ctx, str);
246 parse_str(ctx, str, &ptr);
249 uci_parse_error(ctx, *str, "insufficient arguments");
253 if (name && !uci_validate_name(val))
254 uci_parse_error(ctx, val, "invalid character in field");
261 * verify that the end of the line or command is reached.
262 * throw an error if extra arguments are given on the command line
264 static void assert_eol(struct uci_context *ctx, char **str)
268 tmp = next_arg(ctx, str, false, false);
270 uci_parse_error(ctx, *str, "too many arguments");
274 * switch to a different config, either triggered by uci_load, or by a
275 * 'package <...>' statement in the import file
277 static void uci_switch_config(struct uci_context *ctx)
279 struct uci_parse_context *pctx;
280 struct uci_element *e;
286 /* add the last config to main config file list */
288 uci_list_add(&ctx->root, &pctx->package->e.list);
290 pctx->package = NULL;
291 pctx->section = NULL;
298 * if an older config under the same name exists, unload it
299 * ignore errors here, e.g. if the config was not found
301 e = uci_lookup_list(ctx, &ctx->root, name);
303 UCI_THROW(ctx, UCI_ERR_DUPLICATE);
304 pctx->package = uci_alloc_package(ctx, name);
308 * parse the 'package' uci command (next config package)
310 static void uci_parse_package(struct uci_context *ctx, char **str, bool single)
314 /* command string null-terminated by strtok */
315 *str += strlen(*str) + 1;
317 name = next_arg(ctx, str, true, true);
318 assert_eol(ctx, str);
322 ctx->pctx->name = name;
323 uci_switch_config(ctx);
326 /* Based on an efficient hash function published by D. J. Bernstein */
327 static unsigned int djbhash(unsigned int hash, char *str)
329 int len = strlen(str);
336 for(i = 0; i < len; i++) {
337 hash = ((hash << 5) + hash) + str[i];
339 return (hash & 0x7FFFFFFF);
342 /* fix up an unnamed section */
343 static void uci_fixup_section(struct uci_context *ctx, struct uci_section *s)
345 unsigned int hash = ~0;
346 struct uci_element *e;
353 * Generate a name for unnamed sections. This is used as reference
354 * when locating or updating the section from apps/scripts.
355 * To make multiple concurrent versions somewhat safe for updating,
356 * the name is generated from a hash of its type and name/value
357 * pairs of its option, and it is prefixed by a counter value.
358 * If the order of the unnamed sections changes for some reason,
359 * updates to them will be rejected.
361 hash = djbhash(hash, s->type);
362 uci_foreach_element(&s->options, e) {
363 hash = djbhash(hash, e->name);
364 hash = djbhash(hash, uci_to_option(e)->value);
366 sprintf(buf, "cfg%02x%04x", ++s->package->n_section, hash % (1 << 16));
367 s->e.name = uci_strdup(ctx, buf);
371 * parse the 'config' uci command (open a section)
373 static void uci_parse_config(struct uci_context *ctx, char **str)
375 struct uci_parse_context *pctx = ctx->pctx;
379 uci_fixup_section(ctx, ctx->pctx->section);
380 if (!ctx->pctx->package) {
381 if (!ctx->pctx->name)
382 uci_parse_error(ctx, *str, "attempting to import a file without a package name");
384 uci_switch_config(ctx);
387 /* command string null-terminated by strtok */
388 *str += strlen(*str) + 1;
390 type = next_arg(ctx, str, true, true);
391 name = next_arg(ctx, str, false, true);
392 assert_eol(ctx, str);
395 UCI_TRAP_SAVE(ctx, error);
396 uci_set(ctx, pctx->package, name, NULL, type);
397 UCI_TRAP_RESTORE(ctx);
400 UCI_THROW(ctx, ctx->errno);
402 pctx->section = uci_alloc_section(pctx->package, type, name);
406 * parse the 'option' uci command (open a value)
408 static void uci_parse_option(struct uci_context *ctx, char **str)
410 struct uci_parse_context *pctx = ctx->pctx;
415 uci_parse_error(ctx, *str, "option command found before the first section");
417 /* command string null-terminated by strtok */
418 *str += strlen(*str) + 1;
420 name = next_arg(ctx, str, true, true);
421 value = next_arg(ctx, str, true, false);
422 assert_eol(ctx, str);
425 UCI_TRAP_SAVE(ctx, error);
426 uci_set(ctx, pctx->package, pctx->section->e.name, name, value);
427 UCI_TRAP_RESTORE(ctx);
430 UCI_THROW(ctx, ctx->errno);
432 uci_alloc_option(pctx->section, name, value);
437 * parse a complete input line, split up combined commands by ';'
439 static void uci_parse_line(struct uci_context *ctx, bool single)
441 struct uci_parse_context *pctx = ctx->pctx;
442 char *word, *brk = NULL;
444 for (word = strtok_r(pctx->buf, ";", &brk);
446 word = strtok_r(NULL, ";", &brk)) {
449 word = strtok_r(word, " \t", &pbrk);
453 if ((word[1] == 0) || !strcmp(word + 1, "ackage"))
454 uci_parse_package(ctx, &word, single);
457 if ((word[1] == 0) || !strcmp(word + 1, "onfig"))
458 uci_parse_config(ctx, &word);
461 if ((word[1] == 0) || !strcmp(word + 1, "ption"))
462 uci_parse_option(ctx, &word);
465 uci_parse_error(ctx, word, "unterminated command");
471 /* max number of characters that escaping adds to the string */
472 #define UCI_QUOTE_ESCAPE "'\\''"
475 * escape an uci string for export
477 static char *uci_escape(struct uci_context *ctx, char *str)
483 ctx->bufsz = LINEBUF;
484 ctx->buf = malloc(LINEBUF);
488 p = strchr(str, '\'');
495 if (p + sizeof(UCI_QUOTE_ESCAPE) - str >= ctx->bufsz) {
497 ctx->buf = realloc(ctx->buf, ctx->bufsz);
499 UCI_THROW(ctx, UCI_ERR_MEM);
501 memcpy(&ctx->buf[pos], s, len);
504 strcpy(&ctx->buf[pos], UCI_QUOTE_ESCAPE);
505 pos += sizeof(UCI_QUOTE_ESCAPE);
507 } while ((p = strchr(s, '\'')));
514 * export a single config package to a file stream
516 static void uci_export_package(struct uci_package *p, FILE *stream, bool header)
518 struct uci_context *ctx = p->ctx;
519 struct uci_element *s, *o;
522 fprintf(stream, "package '%s'\n", uci_escape(ctx, p->e.name));
523 uci_foreach_element(&p->sections, s) {
524 struct uci_section *sec = uci_to_section(s);
525 fprintf(stream, "\nconfig '%s'", uci_escape(ctx, sec->type));
527 fprintf(stream, " '%s'", uci_escape(ctx, sec->e.name));
528 fprintf(stream, "\n");
529 uci_foreach_element(&sec->options, o) {
530 struct uci_option *opt = uci_to_option(o);
531 fprintf(stream, "\toption '%s'", uci_escape(ctx, opt->e.name));
532 fprintf(stream, " '%s'\n", uci_escape(ctx, opt->value));
535 fprintf(stream, "\n");
538 int uci_export(struct uci_context *ctx, FILE *stream, struct uci_package *package, bool header)
540 struct uci_element *e;
543 UCI_ASSERT(ctx, stream != NULL);
546 uci_export_package(package, stream, header);
548 uci_foreach_element(&ctx->root, e) {
549 uci_export_package(uci_to_package(e), stream, header);
556 int uci_import(struct uci_context *ctx, FILE *stream, const char *name, struct uci_package **package, bool single)
558 struct uci_parse_context *pctx;
561 /* make sure no memory from previous parse attempts is leaked */
562 uci_file_cleanup(ctx);
564 pctx = (struct uci_parse_context *) uci_malloc(ctx, sizeof(struct uci_parse_context));
567 if (*package && single) {
568 pctx->package = *package;
573 * If 'name' was supplied, assume that the supplied stream does not contain
574 * the appropriate 'package <name>' string to specify the config name
575 * NB: the config file can still override the package name
580 while (!feof(pctx->file)) {
582 UCI_TRAP_SAVE(ctx, error);
584 uci_parse_line(ctx, single);
585 UCI_TRAP_RESTORE(ctx);
588 if (ctx->flags & UCI_FLAG_PERROR)
589 uci_perror(ctx, NULL);
590 if ((ctx->errno != UCI_ERR_PARSE) ||
591 (ctx->flags & UCI_FLAG_STRICT))
592 UCI_THROW(ctx, ctx->errno);
595 uci_fixup_section(ctx, ctx->pctx->section);
597 *package = pctx->package;
599 pctx->package = NULL;
602 uci_switch_config(ctx);
604 /* no error happened, we can get rid of the parser context now */
605 uci_file_cleanup(ctx);
611 * open a stream and go to the right position
613 * note: when opening for write and seeking to the beginning of
614 * the stream, truncate the file
616 static FILE *uci_open_stream(struct uci_context *ctx, const char *filename, int pos, bool write, bool create)
621 int mode = (write ? O_RDWR : O_RDONLY);
626 if (!write && ((stat(filename, &statbuf) < 0) ||
627 ((statbuf.st_mode & S_IFMT) != S_IFREG))) {
628 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
631 fd = open(filename, mode, UCI_FILEMODE);
635 if (flock(fd, (write ? LOCK_EX : LOCK_SH)) < 0)
638 ret = lseek(fd, 0, pos);
643 file = fdopen(fd, (write ? "w+" : "r"));
648 UCI_THROW(ctx, UCI_ERR_IO);
653 static void uci_close_stream(FILE *stream)
665 static void uci_parse_history_line(struct uci_context *ctx, struct uci_package *p, char *buf)
669 char *package = NULL;
670 char *section = NULL;
677 } else if (buf[0] == '@') {
682 UCI_INTERNAL(uci_parse_tuple, ctx, buf, &package, §ion, &option, &value);
683 if (!package || !section || (!delete && !value))
685 if (strcmp(package, p->e.name) != 0)
687 if (!uci_validate_name(section))
689 if (option && !uci_validate_name(option))
693 UCI_INTERNAL(uci_rename, ctx, p, section, option, value);
695 UCI_INTERNAL(uci_delete, ctx, p, section, option);
697 UCI_INTERNAL(uci_set, ctx, p, section, option, value);
701 UCI_THROW(ctx, UCI_ERR_PARSE);
704 static void uci_parse_history(struct uci_context *ctx, FILE *stream, struct uci_package *p)
706 struct uci_parse_context *pctx;
708 /* make sure no memory from previous parse attempts is leaked */
709 uci_file_cleanup(ctx);
711 pctx = (struct uci_parse_context *) uci_malloc(ctx, sizeof(struct uci_parse_context));
715 while (!feof(pctx->file)) {
721 * ignore parse errors in single lines, we want to preserve as much
722 * history as possible
724 UCI_TRAP_SAVE(ctx, error);
725 uci_parse_history_line(ctx, p, pctx->buf);
726 UCI_TRAP_RESTORE(ctx);
731 /* no error happened, we can get rid of the parser context now */
732 uci_file_cleanup(ctx);
735 static void uci_load_history(struct uci_context *ctx, struct uci_package *p, bool flush)
737 char *filename = NULL;
742 if ((asprintf(&filename, "%s/%s", UCI_SAVEDIR, p->e.name) < 0) || !filename)
743 UCI_THROW(ctx, UCI_ERR_MEM);
745 UCI_TRAP_SAVE(ctx, done);
746 f = uci_open_stream(ctx, filename, SEEK_SET, flush, false);
748 uci_parse_history(ctx, f, p);
749 UCI_TRAP_RESTORE(ctx);
754 ftruncate(fileno(f), 0);
763 static char *uci_config_path(struct uci_context *ctx, const char *name)
767 if (strchr(name, '/'))
768 UCI_THROW(ctx, UCI_ERR_INVAL);
769 filename = uci_malloc(ctx, strlen(name) + sizeof(UCI_CONFDIR) + 2);
770 sprintf(filename, UCI_CONFDIR "/%s", name);
775 int uci_load(struct uci_context *ctx, const char *name, struct uci_package **package)
782 UCI_ASSERT(ctx, uci_validate_name(name));
786 /* relative path outside of /etc/config */
788 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
791 /* absolute path outside of /etc/config */
792 filename = uci_strdup(ctx, name);
793 name = strrchr(name, '/') + 1;
797 /* config in /etc/config */
798 filename = uci_config_path(ctx, name);
803 file = uci_open_stream(ctx, filename, SEEK_SET, false, false);
805 UCI_TRAP_SAVE(ctx, done);
806 UCI_INTERNAL(uci_import, ctx, file, name, package, true);
807 UCI_TRAP_RESTORE(ctx);
810 (*package)->path = filename;
811 (*package)->confdir = confdir;
812 uci_load_history(ctx, *package, false);
816 uci_close_stream(file);
820 int uci_save(struct uci_context *ctx, struct uci_package *p)
823 char *filename = NULL;
824 struct uci_element *e, *tmp;
827 UCI_ASSERT(ctx, p != NULL);
830 * if the config file was outside of the /etc/config path,
831 * don't save the history to a file, update the real file
833 * does not modify the uci_package pointer
836 return uci_commit(ctx, &p, false);
838 if (uci_list_empty(&p->history))
841 if ((asprintf(&filename, "%s/%s", UCI_SAVEDIR, p->e.name) < 0) || !filename)
842 UCI_THROW(ctx, UCI_ERR_MEM);
845 UCI_TRAP_SAVE(ctx, done);
846 f = uci_open_stream(ctx, filename, SEEK_END, true, true);
847 UCI_TRAP_RESTORE(ctx);
849 uci_foreach_element_safe(&p->history, tmp, e) {
850 struct uci_history *h = uci_to_history(e);
852 if (h->cmd == UCI_CMD_REMOVE)
854 else if (h->cmd == UCI_CMD_RENAME)
857 fprintf(f, "%s.%s", p->e.name, h->section);
859 fprintf(f, ".%s", e->name);
861 if (h->cmd == UCI_CMD_REMOVE)
864 fprintf(f, "=%s\n", h->value);
873 UCI_THROW(ctx, ctx->errno);
878 int uci_commit(struct uci_context *ctx, struct uci_package **package, bool overwrite)
880 struct uci_package *p;
886 UCI_ASSERT(ctx, package != NULL);
889 UCI_ASSERT(ctx, p != NULL);
892 p->path = uci_config_path(ctx, p->e.name);
894 UCI_THROW(ctx, UCI_ERR_INVAL);
898 /* open the config file for writing now, so that it is locked */
899 f = uci_open_stream(ctx, p->path, SEEK_SET, true, true);
901 /* flush unsaved changes and reload from history file */
902 UCI_TRAP_SAVE(ctx, done);
905 name = uci_strdup(ctx, p->e.name);
906 path = uci_strdup(ctx, p->path);
907 if (!uci_list_empty(&p->history))
908 UCI_INTERNAL(uci_save, ctx, p);
909 uci_free_package(&p);
910 uci_file_cleanup(ctx);
911 UCI_INTERNAL(uci_import, ctx, f, name, &p, true);
917 /* freed together with the uci_package */
920 /* check for updated history, just in case */
921 uci_load_history(ctx, p, true);
924 uci_load_history(ctx, NULL, true);
929 ftruncate(fileno(f), 0);
931 uci_export(ctx, f, p, false);
932 UCI_TRAP_RESTORE(ctx);
941 UCI_THROW(ctx, ctx->errno);
948 * This function returns the filename by returning the string
949 * after the last '/' character. By checking for a non-'\0'
950 * character afterwards, directories are ignored (glob marks
951 * those with a trailing '/'
953 static inline char *get_filename(char *path)
957 p = strrchr(path, '/');
964 int uci_list_configs(struct uci_context *ctx, char ***list)
973 if (glob(UCI_CONFDIR "/*", GLOB_MARK, NULL, &globbuf) != 0)
974 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
976 size = sizeof(char *) * (globbuf.gl_pathc + 1);
977 for(i = 0; i < globbuf.gl_pathc; i++) {
980 p = get_filename(globbuf.gl_pathv[i]);
984 size += strlen(p) + 1;
987 configs = uci_malloc(ctx, size);
988 buf = (char *) &configs[globbuf.gl_pathc + 1];
989 for(i = 0; i < globbuf.gl_pathc; i++) {
992 p = get_filename(globbuf.gl_pathv[i]);
998 buf += strlen(buf) + 1;