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_package(const char *str)
101 return uci_validate_str(str, false);
104 static inline bool uci_validate_type(const char *str)
106 return uci_validate_str(str, false);
109 static inline bool uci_validate_name(const char *str)
111 return uci_validate_str(str, true);
114 bool uci_validate_text(const char *str)
117 if ((*str == '\r') || (*str == '\n') ||
118 ((*str < 32) && (*str != '\t')))
125 static void uci_alloc_parse_context(struct uci_context *ctx)
127 ctx->pctx = (struct uci_parse_context *) uci_malloc(ctx, sizeof(struct uci_parse_context));
130 int uci_parse_ptr(struct uci_context *ctx, struct uci_ptr *ptr, char *str)
136 UCI_ASSERT(ctx, str);
137 UCI_ASSERT(ctx, ptr);
139 memset(ptr, 0, sizeof(struct uci_ptr));
142 last = strchr(str, '=');
149 ptr->package = strsep(&str, ".");
153 ptr->section = strsep(&str, ".");
155 ptr->target = UCI_TYPE_PACKAGE;
159 ptr->option = strsep(&str, ".");
161 ptr->target = UCI_TYPE_SECTION;
164 ptr->target = UCI_TYPE_OPTION;
167 tmp = strsep(&str, ".");
172 if (ptr->package && !uci_validate_package(ptr->package))
174 if (ptr->section && !uci_validate_name(ptr->section))
175 ptr->flags |= UCI_LOOKUP_EXTENDED;
176 if (ptr->option && !uci_validate_name(ptr->option))
178 if (ptr->value && !uci_validate_text(ptr->value))
184 memset(ptr, 0, sizeof(struct uci_ptr));
185 UCI_THROW(ctx, UCI_ERR_PARSE);
189 static void uci_parse_error(struct uci_context *ctx, char *pos, char *reason)
191 struct uci_parse_context *pctx = ctx->pctx;
193 pctx->reason = reason;
194 pctx->byte = pos - pctx->buf;
195 UCI_THROW(ctx, UCI_ERR_PARSE);
200 * Fetch a new line from the input stream and resize buffer if necessary
202 static void uci_getln(struct uci_context *ctx, int offset)
204 struct uci_parse_context *pctx = ctx->pctx;
208 if (pctx->buf == NULL) {
209 pctx->buf = uci_malloc(ctx, LINEBUF);
210 pctx->bufsz = LINEBUF;
218 p = fgets(p, pctx->bufsz - ofs, pctx->file);
223 if (pctx->buf[ofs - 1] == '\n') {
225 pctx->buf[ofs - 1] = 0;
229 if (pctx->bufsz > LINEBUF_MAX/2)
230 uci_parse_error(ctx, p, "line too long");
233 pctx->buf = uci_realloc(ctx, pctx->buf, pctx->bufsz);
238 * parse a character escaped by '\'
239 * returns true if the escaped character is to be parsed
240 * returns false if the escaped character is to be ignored
242 static inline bool parse_backslash(struct uci_context *ctx, char **str)
247 /* undecoded backslash at the end of line, fetch the next line */
250 uci_getln(ctx, *str - ctx->pctx->buf);
254 /* FIXME: decode escaped char, necessary? */
259 * move the string pointer forward until a non-whitespace character or
262 static void skip_whitespace(struct uci_context *ctx, char **str)
265 while (**str && isspace(**str))
269 if (!parse_backslash(ctx, str))
274 static inline void addc(char **dest, char **src)
282 * parse a double quoted string argument from the command line
284 static void parse_double_quote(struct uci_context *ctx, char **str, char **target)
288 /* skip quote character */
291 while ((c = **str)) {
298 if (!parse_backslash(ctx, str))
306 uci_parse_error(ctx, *str, "unterminated \"");
310 * parse a single quoted string argument from the command line
312 static void parse_single_quote(struct uci_context *ctx, char **str, char **target)
315 /* skip quote character */
318 while ((c = **str)) {
328 uci_parse_error(ctx, *str, "unterminated '");
332 * parse a string from the command line and detect the quoting style
334 static void parse_str(struct uci_context *ctx, char **str, char **target)
340 parse_single_quote(ctx, str, target);
343 parse_double_quote(ctx, str, target);
354 if (!parse_backslash(ctx, str))
361 } while (**str && !isspace(**str));
365 * if the string was unquoted and we've stopped at a whitespace
366 * character, skip to the next one, because the whitespace will
367 * be overwritten by a null byte here
372 /* terminate the parsed string */
377 * extract the next argument from the command line
379 static char *next_arg(struct uci_context *ctx, char **str, bool required, bool name)
385 skip_whitespace(ctx, str);
390 parse_str(ctx, str, &ptr);
394 uci_parse_error(ctx, *str, "insufficient arguments");
398 if (name && !uci_validate_name(val))
399 uci_parse_error(ctx, val, "invalid character in field");
405 int uci_parse_argument(struct uci_context *ctx, FILE *stream, char **str, char **result)
408 UCI_ASSERT(ctx, str != NULL);
409 UCI_ASSERT(ctx, result != NULL);
411 if (ctx->pctx && (ctx->pctx->file != stream))
415 uci_alloc_parse_context(ctx);
417 ctx->pctx->file = stream;
421 *str = ctx->pctx->buf;
424 *result = next_arg(ctx, str, false, false);
431 * open a stream and go to the right position
433 * note: when opening for write and seeking to the beginning of
434 * the stream, truncate the file
436 static FILE *uci_open_stream(struct uci_context *ctx, const char *filename, int pos, bool write, bool create)
441 int mode = (write ? O_RDWR : O_RDONLY);
446 if (!write && ((stat(filename, &statbuf) < 0) ||
447 ((statbuf.st_mode & S_IFMT) != S_IFREG))) {
448 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
451 fd = open(filename, mode, UCI_FILEMODE);
455 if (flock(fd, (write ? LOCK_EX : LOCK_SH)) < 0)
458 ret = lseek(fd, 0, pos);
463 file = fdopen(fd, (write ? "w+" : "r"));
468 UCI_THROW(ctx, UCI_ERR_IO);
473 static void uci_close_stream(FILE *stream)