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 misc utility functions and wrappers to standard
17 * functions, which throw exceptions upon failure.
19 #include <sys/types.h>
28 #define LINEBUF_MAX 4096
30 __plugin void *uci_malloc(struct uci_context *ctx, size_t size)
36 UCI_THROW(ctx, UCI_ERR_MEM);
42 __plugin void *uci_realloc(struct uci_context *ctx, void *ptr, size_t size)
44 ptr = realloc(ptr, size);
46 UCI_THROW(ctx, UCI_ERR_MEM);
51 __plugin char *uci_strdup(struct uci_context *ctx, const char *str)
57 UCI_THROW(ctx, UCI_ERR_MEM);
62 /* Based on an efficient hash function published by D. J. Bernstein */
63 static unsigned int djbhash(unsigned int hash, char *str)
65 int len = strlen(str);
72 for(i = 0; i < len; i++) {
73 hash = ((hash << 5) + hash) + str[i];
75 return (hash & 0x7FFFFFFF);
79 * validate strings for names and types, reject special characters
80 * for names, only alphanum and _ is allowed (shell compatibility)
81 * for types, we allow more characters
83 __plugin bool uci_validate_str(const char *str, bool name)
90 if (!isalnum(c) && c != '_') {
91 if (name || (c < 33) || (c > 126))
99 static inline bool uci_validate_name(const char *str)
101 return uci_validate_str(str, true);
104 static inline bool uci_validate_text(const char *str)
107 if ((*str == '\r') || (*str == '\n') ||
108 ((*str < 32) && (*str != '\t')))
114 static void uci_alloc_parse_context(struct uci_context *ctx)
116 ctx->pctx = (struct uci_parse_context *) uci_malloc(ctx, sizeof(struct uci_parse_context));
119 int uci_parse_tuple(struct uci_context *ctx, char *str, char **package, char **section, char **option, char **value)
124 UCI_ASSERT(ctx, str && package && section && option);
126 last = strchr(str, '=');
132 *package = strsep(&str, ".");
133 if (!*package || !uci_validate_str(*package, false))
136 *section = strsep(&str, ".");
142 *option = strsep(&str, ".");
156 if (*section && *section[0] && !uci_validate_name(*section))
158 if (*option && !uci_validate_name(*option))
160 if (*value && !uci_validate_text(*value))
166 UCI_THROW(ctx, UCI_ERR_PARSE);
173 static void uci_parse_error(struct uci_context *ctx, char *pos, char *reason)
175 struct uci_parse_context *pctx = ctx->pctx;
177 pctx->reason = reason;
178 pctx->byte = pos - pctx->buf;
179 UCI_THROW(ctx, UCI_ERR_PARSE);
184 * Fetch a new line from the input stream and resize buffer if necessary
186 static void uci_getln(struct uci_context *ctx, int offset)
188 struct uci_parse_context *pctx = ctx->pctx;
192 if (pctx->buf == NULL) {
193 pctx->buf = uci_malloc(ctx, LINEBUF);
194 pctx->bufsz = LINEBUF;
202 p = fgets(p, pctx->bufsz - ofs, pctx->file);
207 if (pctx->buf[ofs - 1] == '\n') {
209 pctx->buf[ofs - 1] = 0;
213 if (pctx->bufsz > LINEBUF_MAX/2)
214 uci_parse_error(ctx, p, "line too long");
217 pctx->buf = uci_realloc(ctx, pctx->buf, pctx->bufsz);
222 * parse a character escaped by '\'
223 * returns true if the escaped character is to be parsed
224 * returns false if the escaped character is to be ignored
226 static inline bool parse_backslash(struct uci_context *ctx, char **str)
231 /* undecoded backslash at the end of line, fetch the next line */
234 uci_getln(ctx, *str - ctx->pctx->buf);
238 /* FIXME: decode escaped char, necessary? */
243 * move the string pointer forward until a non-whitespace character or
246 static void skip_whitespace(struct uci_context *ctx, char **str)
249 while (**str && isspace(**str))
253 if (!parse_backslash(ctx, str))
258 static inline void addc(char **dest, char **src)
266 * parse a double quoted string argument from the command line
268 static void parse_double_quote(struct uci_context *ctx, char **str, char **target)
272 /* skip quote character */
275 while ((c = **str)) {
282 if (!parse_backslash(ctx, str))
290 uci_parse_error(ctx, *str, "unterminated \"");
294 * parse a single quoted string argument from the command line
296 static void parse_single_quote(struct uci_context *ctx, char **str, char **target)
299 /* skip quote character */
302 while ((c = **str)) {
312 uci_parse_error(ctx, *str, "unterminated '");
316 * parse a string from the command line and detect the quoting style
318 static void parse_str(struct uci_context *ctx, char **str, char **target)
324 parse_single_quote(ctx, str, target);
327 parse_double_quote(ctx, str, target);
338 if (!parse_backslash(ctx, str))
345 } while (**str && !isspace(**str));
349 * if the string was unquoted and we've stopped at a whitespace
350 * character, skip to the next one, because the whitespace will
351 * be overwritten by a null byte here
356 /* terminate the parsed string */
361 * extract the next argument from the command line
363 static char *next_arg(struct uci_context *ctx, char **str, bool required, bool name)
369 skip_whitespace(ctx, str);
374 parse_str(ctx, str, &ptr);
378 uci_parse_error(ctx, *str, "insufficient arguments");
382 if (name && !uci_validate_name(val))
383 uci_parse_error(ctx, val, "invalid character in field");
389 int uci_parse_argument(struct uci_context *ctx, FILE *stream, char **str, char **result)
392 UCI_ASSERT(ctx, str != NULL);
393 UCI_ASSERT(ctx, result != NULL);
396 if (ctx->pctx->file != stream) {
400 uci_alloc_parse_context(ctx);
401 ctx->pctx->file = stream;
405 *str = ctx->pctx->buf;
408 *result = next_arg(ctx, str, false, false);
415 * open a stream and go to the right position
417 * note: when opening for write and seeking to the beginning of
418 * the stream, truncate the file
420 static FILE *uci_open_stream(struct uci_context *ctx, const char *filename, int pos, bool write, bool create)
425 int mode = (write ? O_RDWR : O_RDONLY);
430 if (!write && ((stat(filename, &statbuf) < 0) ||
431 ((statbuf.st_mode & S_IFMT) != S_IFREG))) {
432 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
435 fd = open(filename, mode, UCI_FILEMODE);
439 if (flock(fd, (write ? LOCK_EX : LOCK_SH)) < 0)
442 ret = lseek(fd, 0, pos);
447 file = fdopen(fd, (write ? "w+" : "r"));
452 UCI_THROW(ctx, UCI_ERR_IO);
457 static void uci_close_stream(FILE *stream)