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>
29 #define LINEBUF_MAX 4096
31 __plugin void *uci_malloc(struct uci_context *ctx, size_t size)
37 UCI_THROW(ctx, UCI_ERR_MEM);
43 __plugin void *uci_realloc(struct uci_context *ctx, void *ptr, size_t size)
45 ptr = realloc(ptr, size);
47 UCI_THROW(ctx, UCI_ERR_MEM);
52 __plugin char *uci_strdup(struct uci_context *ctx, const char *str)
58 UCI_THROW(ctx, UCI_ERR_MEM);
63 /* Based on an efficient hash function published by D. J. Bernstein */
64 static unsigned int djbhash(unsigned int hash, char *str)
66 int len = strlen(str);
73 for(i = 0; i < len; i++) {
74 hash = ((hash << 5) + hash) + str[i];
76 return (hash & 0x7FFFFFFF);
80 * validate strings for names and types, reject special characters
81 * for names, only alphanum and _ is allowed (shell compatibility)
82 * for types, we allow more characters
84 __plugin bool uci_validate_str(const char *str, bool name)
90 unsigned char c = *str;
91 if (!isalnum(c) && c != '_') {
92 if (name || (c < 33) || (c > 126))
100 static inline bool uci_validate_package(const char *str)
102 return uci_validate_str(str, false);
105 static inline bool uci_validate_type(const char *str)
107 return uci_validate_str(str, false);
110 static inline bool uci_validate_name(const char *str)
112 return uci_validate_str(str, true);
115 bool uci_validate_text(const char *str)
118 unsigned char c = *str;
119 if ((c == '\r') || (c == '\n') ||
120 ((c < 32) && (c != '\t')))
127 static void uci_alloc_parse_context(struct uci_context *ctx)
129 ctx->pctx = (struct uci_parse_context *) uci_malloc(ctx, sizeof(struct uci_parse_context));
132 int uci_parse_ptr(struct uci_context *ctx, struct uci_ptr *ptr, char *str)
138 UCI_ASSERT(ctx, str);
139 UCI_ASSERT(ctx, ptr);
141 memset(ptr, 0, sizeof(struct uci_ptr));
144 last = strchr(str, '=');
151 ptr->package = strsep(&str, ".");
155 ptr->section = strsep(&str, ".");
157 ptr->target = UCI_TYPE_PACKAGE;
161 ptr->option = strsep(&str, ".");
163 ptr->target = UCI_TYPE_SECTION;
166 ptr->target = UCI_TYPE_OPTION;
169 tmp = strsep(&str, ".");
174 if (ptr->package && !uci_validate_package(ptr->package))
176 if (ptr->section && !uci_validate_name(ptr->section))
177 ptr->flags |= UCI_LOOKUP_EXTENDED;
178 if (ptr->option && !uci_validate_name(ptr->option))
180 if (ptr->value && !uci_validate_text(ptr->value))
186 memset(ptr, 0, sizeof(struct uci_ptr));
187 UCI_THROW(ctx, UCI_ERR_PARSE);
191 static void uci_parse_error(struct uci_context *ctx, char *pos, char *reason)
193 struct uci_parse_context *pctx = ctx->pctx;
195 pctx->reason = reason;
196 pctx->byte = pos - pctx->buf;
197 UCI_THROW(ctx, UCI_ERR_PARSE);
202 * Fetch a new line from the input stream and resize buffer if necessary
204 static void uci_getln(struct uci_context *ctx, int offset)
206 struct uci_parse_context *pctx = ctx->pctx;
210 if (pctx->buf == NULL) {
211 pctx->buf = uci_malloc(ctx, LINEBUF);
212 pctx->bufsz = LINEBUF;
220 p = fgets(p, pctx->bufsz - ofs, pctx->file);
225 if (pctx->buf[ofs - 1] == '\n') {
227 pctx->buf[ofs - 1] = 0;
231 if (pctx->bufsz > LINEBUF_MAX/2)
232 uci_parse_error(ctx, p, "line too long");
235 pctx->buf = uci_realloc(ctx, pctx->buf, pctx->bufsz);
240 * parse a character escaped by '\'
241 * returns true if the escaped character is to be parsed
242 * returns false if the escaped character is to be ignored
244 static inline bool parse_backslash(struct uci_context *ctx, char **str)
249 /* undecoded backslash at the end of line, fetch the next line */
252 uci_getln(ctx, *str - ctx->pctx->buf);
256 /* FIXME: decode escaped char, necessary? */
261 * move the string pointer forward until a non-whitespace character or
264 static void skip_whitespace(struct uci_context *ctx, char **str)
267 while (**str && isspace(**str))
271 if (!parse_backslash(ctx, str))
276 static inline void addc(char **dest, char **src)
284 * parse a double quoted string argument from the command line
286 static void parse_double_quote(struct uci_context *ctx, char **str, char **target)
290 /* skip quote character */
293 while ((c = **str)) {
300 if (!parse_backslash(ctx, str))
308 uci_parse_error(ctx, *str, "unterminated \"");
312 * parse a single quoted string argument from the command line
314 static void parse_single_quote(struct uci_context *ctx, char **str, char **target)
317 /* skip quote character */
320 while ((c = **str)) {
330 uci_parse_error(ctx, *str, "unterminated '");
334 * parse a string from the command line and detect the quoting style
336 static void parse_str(struct uci_context *ctx, char **str, char **target)
342 parse_single_quote(ctx, str, target);
345 parse_double_quote(ctx, str, target);
356 if (!parse_backslash(ctx, str))
363 } while (**str && !isspace(**str));
367 * if the string was unquoted and we've stopped at a whitespace
368 * character, skip to the next one, because the whitespace will
369 * be overwritten by a null byte here
374 /* terminate the parsed string */
379 * extract the next argument from the command line
381 static char *next_arg(struct uci_context *ctx, char **str, bool required, bool name)
387 skip_whitespace(ctx, str);
392 parse_str(ctx, str, &ptr);
396 uci_parse_error(ctx, *str, "insufficient arguments");
400 if (name && !uci_validate_name(val))
401 uci_parse_error(ctx, val, "invalid character in field");
407 int uci_parse_argument(struct uci_context *ctx, FILE *stream, char **str, char **result)
410 UCI_ASSERT(ctx, str != NULL);
411 UCI_ASSERT(ctx, result != NULL);
413 if (ctx->pctx && (ctx->pctx->file != stream))
417 uci_alloc_parse_context(ctx);
419 ctx->pctx->file = stream;
423 *str = ctx->pctx->buf;
426 *result = next_arg(ctx, str, false, false);
433 * open a stream and go to the right position
435 * note: when opening for write and seeking to the beginning of
436 * the stream, truncate the file
438 static FILE *uci_open_stream(struct uci_context *ctx, const char *filename, int pos, bool write, bool create)
443 int mode = (write ? O_RDWR : O_RDONLY);
448 if (!write && ((stat(filename, &statbuf) < 0) ||
449 ((statbuf.st_mode & S_IFMT) != S_IFREG))) {
450 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
453 fd = open(filename, mode, UCI_FILEMODE);
457 ret = flock(fd, (write ? LOCK_EX : LOCK_SH));
458 if ((ret < 0) && (errno != ENOSYS))
461 ret = lseek(fd, 0, pos);
466 file = fdopen(fd, (write ? "w+" : "r"));
471 UCI_THROW(ctx, UCI_ERR_IO);
476 static void uci_close_stream(FILE *stream)