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;
376 struct uci_section *s;
380 uci_fixup_section(ctx, ctx->pctx->section);
381 if (!ctx->pctx->package) {
382 if (!ctx->pctx->name)
383 uci_parse_error(ctx, *str, "attempting to import a file without a package name");
385 uci_switch_config(ctx);
388 /* command string null-terminated by strtok */
389 *str += strlen(*str) + 1;
391 type = next_arg(ctx, str, true, true);
392 name = next_arg(ctx, str, false, true);
393 assert_eol(ctx, str);
396 UCI_INTERNAL(uci_set, ctx, pctx->package, name, NULL, type);
398 pctx->section = uci_alloc_section(pctx->package, type, name);
402 * parse the 'option' uci command (open a value)
404 static void uci_parse_option(struct uci_context *ctx, char **str)
406 struct uci_parse_context *pctx = ctx->pctx;
411 uci_parse_error(ctx, *str, "option command found before the first section");
413 /* command string null-terminated by strtok */
414 *str += strlen(*str) + 1;
416 name = next_arg(ctx, str, true, true);
417 value = next_arg(ctx, str, true, false);
418 assert_eol(ctx, str);
421 UCI_INTERNAL(uci_set, ctx, pctx->package, pctx->section->e.name, name, value);
423 uci_alloc_option(pctx->section, name, value);
428 * parse a complete input line, split up combined commands by ';'
430 static void uci_parse_line(struct uci_context *ctx, bool single)
432 struct uci_parse_context *pctx = ctx->pctx;
433 char *word, *brk = NULL;
435 for (word = strtok_r(pctx->buf, ";", &brk);
437 word = strtok_r(NULL, ";", &brk)) {
440 word = strtok_r(word, " \t", &pbrk);
444 if ((word[1] == 0) || !strcmp(word + 1, "ackage"))
445 uci_parse_package(ctx, &word, single);
448 if ((word[1] == 0) || !strcmp(word + 1, "onfig"))
449 uci_parse_config(ctx, &word);
452 if ((word[1] == 0) || !strcmp(word + 1, "ption"))
453 uci_parse_option(ctx, &word);
456 uci_parse_error(ctx, word, "unterminated command");
462 /* max number of characters that escaping adds to the string */
463 #define UCI_QUOTE_ESCAPE "'\\''"
466 * escape an uci string for export
468 static char *uci_escape(struct uci_context *ctx, char *str)
474 ctx->bufsz = LINEBUF;
475 ctx->buf = malloc(LINEBUF);
479 p = strchr(str, '\'');
486 if (p + sizeof(UCI_QUOTE_ESCAPE) - str >= ctx->bufsz) {
488 ctx->buf = realloc(ctx->buf, ctx->bufsz);
490 UCI_THROW(ctx, UCI_ERR_MEM);
492 memcpy(&ctx->buf[pos], s, len);
495 strcpy(&ctx->buf[pos], UCI_QUOTE_ESCAPE);
496 pos += sizeof(UCI_QUOTE_ESCAPE);
498 } while ((p = strchr(s, '\'')));
505 * export a single config package to a file stream
507 static void uci_export_package(struct uci_package *p, FILE *stream, bool header)
509 struct uci_context *ctx = p->ctx;
510 struct uci_element *s, *o;
513 fprintf(stream, "package '%s'\n", uci_escape(ctx, p->e.name));
514 uci_foreach_element(&p->sections, s) {
515 struct uci_section *sec = uci_to_section(s);
516 fprintf(stream, "\nconfig '%s'", uci_escape(ctx, sec->type));
518 fprintf(stream, " '%s'", uci_escape(ctx, sec->e.name));
519 fprintf(stream, "\n");
520 uci_foreach_element(&sec->options, o) {
521 struct uci_option *opt = uci_to_option(o);
522 fprintf(stream, "\toption '%s'", uci_escape(ctx, opt->e.name));
523 fprintf(stream, " '%s'\n", uci_escape(ctx, opt->value));
526 fprintf(stream, "\n");
529 int uci_export(struct uci_context *ctx, FILE *stream, struct uci_package *package, bool header)
531 struct uci_element *e;
534 UCI_ASSERT(ctx, stream != NULL);
537 uci_export_package(package, stream, header);
539 uci_foreach_element(&ctx->root, e) {
540 uci_export_package(uci_to_package(e), stream, header);
547 int uci_import(struct uci_context *ctx, FILE *stream, const char *name, struct uci_package **package, bool single)
549 struct uci_parse_context *pctx;
552 /* make sure no memory from previous parse attempts is leaked */
553 uci_file_cleanup(ctx);
555 pctx = (struct uci_parse_context *) uci_malloc(ctx, sizeof(struct uci_parse_context));
558 if (*package && single) {
559 pctx->package = *package;
564 * If 'name' was supplied, assume that the supplied stream does not contain
565 * the appropriate 'package <name>' string to specify the config name
566 * NB: the config file can still override the package name
571 while (!feof(pctx->file)) {
573 UCI_TRAP_SAVE(ctx, error);
575 uci_parse_line(ctx, single);
576 UCI_TRAP_RESTORE(ctx);
579 if (ctx->flags & UCI_FLAG_PERROR)
580 uci_perror(ctx, NULL);
581 if ((ctx->errno != UCI_ERR_PARSE) ||
582 (ctx->flags & UCI_FLAG_STRICT))
583 UCI_THROW(ctx, ctx->errno);
586 uci_fixup_section(ctx, ctx->pctx->section);
588 *package = pctx->package;
591 uci_switch_config(ctx);
593 /* no error happened, we can get rid of the parser context now */
594 uci_file_cleanup(ctx);
600 * open a stream and go to the right position
602 * note: when opening for write and seeking to the beginning of
603 * the stream, truncate the file
605 static FILE *uci_open_stream(struct uci_context *ctx, const char *filename, int pos, bool write, bool create)
610 int mode = (write ? O_RDWR : O_RDONLY);
615 if (!write && ((stat(filename, &statbuf) < 0) ||
616 ((statbuf.st_mode & S_IFMT) != S_IFREG))) {
617 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
620 fd = open(filename, mode, UCI_FILEMODE);
624 if (flock(fd, (write ? LOCK_EX : LOCK_SH)) < 0)
627 ret = lseek(fd, 0, pos);
632 file = fdopen(fd, (write ? "w+" : "r"));
637 UCI_THROW(ctx, UCI_ERR_IO);
642 static void uci_close_stream(FILE *stream)
654 static void uci_parse_history_line(struct uci_context *ctx, struct uci_package *p, char *buf)
658 char *package = NULL;
659 char *section = NULL;
666 } else if (buf[0] == '@') {
671 UCI_INTERNAL(uci_parse_tuple, ctx, buf, &package, §ion, &option, &value);
672 if (!package || !section || (!delete && !value))
674 if (strcmp(package, p->e.name) != 0)
676 if (!uci_validate_name(section))
678 if (option && !uci_validate_name(option))
682 UCI_INTERNAL(uci_rename, ctx, p, section, option, value);
684 UCI_INTERNAL(uci_delete, ctx, p, section, option);
686 UCI_INTERNAL(uci_set, ctx, p, section, option, value);
690 UCI_THROW(ctx, UCI_ERR_PARSE);
693 static void uci_parse_history(struct uci_context *ctx, FILE *stream, struct uci_package *p)
695 struct uci_parse_context *pctx;
697 /* make sure no memory from previous parse attempts is leaked */
698 uci_file_cleanup(ctx);
700 pctx = (struct uci_parse_context *) uci_malloc(ctx, sizeof(struct uci_parse_context));
704 while (!feof(pctx->file)) {
710 * ignore parse errors in single lines, we want to preserve as much
711 * history as possible
713 UCI_TRAP_SAVE(ctx, error);
714 uci_parse_history_line(ctx, p, pctx->buf);
715 UCI_TRAP_RESTORE(ctx);
720 /* no error happened, we can get rid of the parser context now */
721 uci_file_cleanup(ctx);
724 static void uci_load_history(struct uci_context *ctx, struct uci_package *p, bool flush)
726 char *filename = NULL;
731 if ((asprintf(&filename, "%s/%s", UCI_SAVEDIR, p->e.name) < 0) || !filename)
732 UCI_THROW(ctx, UCI_ERR_MEM);
734 UCI_TRAP_SAVE(ctx, done);
735 f = uci_open_stream(ctx, filename, SEEK_SET, flush, false);
736 uci_parse_history(ctx, f, p);
737 UCI_TRAP_RESTORE(ctx);
742 ftruncate(fileno(f), 0);
751 int uci_load(struct uci_context *ctx, const char *name, struct uci_package **package)
758 UCI_ASSERT(ctx, name != NULL);
762 /* relative path outside of /etc/config */
764 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
767 /* absolute path outside of /etc/config */
768 filename = uci_strdup(ctx, name);
769 name = strrchr(name, '/') + 1;
773 /* config in /etc/config */
774 if (strchr(name, '/'))
775 UCI_THROW(ctx, UCI_ERR_INVAL);
776 filename = uci_malloc(ctx, strlen(name) + sizeof(UCI_CONFDIR) + 2);
777 sprintf(filename, UCI_CONFDIR "/%s", name);
782 file = uci_open_stream(ctx, filename, SEEK_SET, false, false);
784 UCI_TRAP_SAVE(ctx, done);
785 uci_import(ctx, file, name, package, true);
786 UCI_TRAP_RESTORE(ctx);
789 (*package)->path = filename;
790 (*package)->confdir = confdir;
791 uci_load_history(ctx, *package, false);
795 uci_close_stream(file);
799 int uci_save(struct uci_context *ctx, struct uci_package *p)
802 char *filename = NULL;
803 struct uci_element *e, *tmp;
806 UCI_ASSERT(ctx, p != NULL);
809 * if the config file was outside of the /etc/config path,
810 * don't save the history to a file, update the real file
812 * does not modify the uci_package pointer
815 return uci_commit(ctx, &p);
817 if (uci_list_empty(&p->history))
820 if ((asprintf(&filename, "%s/%s", UCI_SAVEDIR, p->e.name) < 0) || !filename)
821 UCI_THROW(ctx, UCI_ERR_MEM);
824 UCI_TRAP_SAVE(ctx, done);
825 f = uci_open_stream(ctx, filename, SEEK_END, true, true);
826 UCI_TRAP_RESTORE(ctx);
828 uci_foreach_element_safe(&p->history, tmp, e) {
829 struct uci_history *h = uci_to_history(e);
831 if (h->cmd == UCI_CMD_REMOVE)
833 else if (h->cmd == UCI_CMD_RENAME)
836 fprintf(f, "%s.%s", p->e.name, h->section);
838 fprintf(f, ".%s", e->name);
840 if (h->cmd == UCI_CMD_REMOVE)
843 fprintf(f, "=%s\n", h->value);
852 UCI_THROW(ctx, ctx->errno);
857 int uci_commit(struct uci_context *ctx, struct uci_package **package)
859 struct uci_package *p;
865 UCI_ASSERT(ctx, package != NULL);
868 UCI_ASSERT(ctx, p != NULL);
869 UCI_ASSERT(ctx, p->path != NULL);
871 /* open the config file for writing now, so that it is locked */
872 f = uci_open_stream(ctx, p->path, SEEK_SET, true, true);
874 /* flush unsaved changes and reload from history file */
875 UCI_TRAP_SAVE(ctx, done);
877 name = uci_strdup(ctx, p->e.name);
878 path = uci_strdup(ctx, p->path);
879 if (!uci_list_empty(&p->history))
880 UCI_INTERNAL(uci_save, ctx, p);
881 uci_free_package(&p);
882 uci_file_cleanup(ctx);
883 UCI_INTERNAL(uci_import, ctx, f, name, &p, true);
889 /* freed together with the uci_package */
892 /* check for updated history, just in case */
893 uci_load_history(ctx, p, true);
897 ftruncate(fileno(f), 0);
899 uci_export(ctx, f, p, false);
900 UCI_TRAP_RESTORE(ctx);
909 UCI_THROW(ctx, ctx->errno);
916 * This function returns the filename by returning the string
917 * after the last '/' character. By checking for a non-'\0'
918 * character afterwards, directories are ignored (glob marks
919 * those with a trailing '/'
921 static inline char *get_filename(char *path)
925 p = strrchr(path, '/');
932 int uci_list_configs(struct uci_context *ctx, char ***list)
941 if (glob(UCI_CONFDIR "/*", GLOB_MARK, NULL, &globbuf) != 0)
942 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
944 size = sizeof(char *) * (globbuf.gl_pathc + 1);
945 for(i = 0; i < globbuf.gl_pathc; i++) {
948 p = get_filename(globbuf.gl_pathv[i]);
952 size += strlen(p) + 1;
955 configs = uci_malloc(ctx, size);
956 buf = (char *) &configs[globbuf.gl_pathc + 1];
957 for(i = 0; i < globbuf.gl_pathc; i++) {
960 p = get_filename(globbuf.gl_pathv[i]);
966 buf += strlen(buf) + 1;