X-Git-Url: http://git.archive.openwrt.org/?p=project%2Fuci.git;a=blobdiff_plain;f=util.c;h=4713c74befe6eab5935c2d6be48033c95f64204a;hp=c0f4451debf0946374314c87e50507bcf30eb107;hb=031b620e1f3a16078da45ce00352508764902786;hpb=a49b8b7e23945590fc35c7a8ef904169e856368b

diff --git a/util.c b/util.c
index c0f4451..4713c74 100644
--- a/util.c
+++ b/util.c
@@ -16,8 +16,16 @@
  * This file contains wrappers to standard functions, which
  * throw exceptions upon failure.
  */
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/file.h>
 #include <stdbool.h>
+#include <unistd.h>
 #include <ctype.h>
+#include <fcntl.h>
+
+#define LINEBUF	32
+#define LINEBUF_MAX	4096
 
 static void *uci_malloc(struct uci_context *ctx, size_t size)
 {
@@ -51,19 +59,37 @@ static char *uci_strdup(struct uci_context *ctx, const char *str)
 	return ptr;
 }
 
-static bool uci_validate_name(const char *str)
+/*
+ * validate strings for names and types, reject special characters
+ * for names, only alphanum and _ is allowed (shell compatibility)
+ * for types, we allow more characters
+ */
+static bool uci_validate_str(const char *str, bool name)
 {
 	if (!*str)
 		return false;
 
 	while (*str) {
-		if (!isalnum(*str) && (*str != '_'))
-			return false;
+		char c = *str;
+		if (!isalnum(c) && c != '_') {
+			if (name || (c < 33) || (c > 126))
+				return false;
+		}
 		str++;
 	}
 	return true;
 }
 
+static inline bool uci_validate_name(const char *str)
+{
+	return uci_validate_str(str, true);
+}
+
+static void uci_alloc_parse_context(struct uci_context *ctx)
+{
+	ctx->pctx = (struct uci_parse_context *) uci_malloc(ctx, sizeof(struct uci_parse_context));
+}
+
 int uci_parse_tuple(struct uci_context *ctx, char *str, char **package, char **section, char **option, char **value)
 {
 	char *last = NULL;
@@ -114,3 +140,293 @@ done:
 	return 0;
 }
 
+
+static void uci_parse_error(struct uci_context *ctx, char *pos, char *reason)
+{
+	struct uci_parse_context *pctx = ctx->pctx;
+
+	pctx->reason = reason;
+	pctx->byte = pos - pctx->buf;
+	UCI_THROW(ctx, UCI_ERR_PARSE);
+}
+
+
+/*
+ * Fetch a new line from the input stream and resize buffer if necessary
+ */
+static void uci_getln(struct uci_context *ctx, int offset)
+{
+	struct uci_parse_context *pctx = ctx->pctx;
+	char *p;
+	int ofs;
+
+	if (pctx->buf == NULL) {
+		pctx->buf = uci_malloc(ctx, LINEBUF);
+		pctx->bufsz = LINEBUF;
+	}
+
+	ofs = offset;
+	do {
+		p = &pctx->buf[ofs];
+		p[ofs] = 0;
+
+		p = fgets(p, pctx->bufsz - ofs, pctx->file);
+		if (!p || !*p)
+			return;
+
+		ofs += strlen(p);
+		if (pctx->buf[ofs - 1] == '\n') {
+			pctx->line++;
+			pctx->buf[ofs - 1] = 0;
+			return;
+		}
+
+		if (pctx->bufsz > LINEBUF_MAX/2)
+			uci_parse_error(ctx, p, "line too long");
+
+		pctx->bufsz *= 2;
+		pctx->buf = uci_realloc(ctx, pctx->buf, pctx->bufsz);
+	} while (1);
+}
+
+/* 
+ * parse a character escaped by '\'
+ * returns true if the escaped character is to be parsed
+ * returns false if the escaped character is to be ignored
+ */
+static inline bool parse_backslash(struct uci_context *ctx, char **str)
+{
+	/* skip backslash */
+	*str += 1;
+
+	/* undecoded backslash at the end of line, fetch the next line */
+	if (!**str) {
+		*str += 1;
+		uci_getln(ctx, *str - ctx->pctx->buf);
+		return false;
+	}
+
+	/* FIXME: decode escaped char, necessary? */
+	return true;
+}
+
+/*
+ * move the string pointer forward until a non-whitespace character or
+ * EOL is reached
+ */
+static void skip_whitespace(struct uci_context *ctx, char **str)
+{
+restart:
+	while (**str && isspace(**str))
+		*str += 1;
+
+	if (**str == '\\') {
+		if (!parse_backslash(ctx, str))
+			goto restart;
+	}
+}
+
+static inline void addc(char **dest, char **src)
+{
+	**dest = **src;
+	*dest += 1;
+	*src += 1;
+}
+
+/*
+ * parse a double quoted string argument from the command line
+ */
+static void parse_double_quote(struct uci_context *ctx, char **str, char **target)
+{
+	char c;
+
+	/* skip quote character */
+	*str += 1;
+
+	while ((c = **str)) {
+		switch(c) {
+		case '"':
+			**target = 0;
+			*str += 1;
+			return;
+		case '\\':
+			if (!parse_backslash(ctx, str))
+				continue;
+			/* fall through */
+		default:
+			addc(target, str);
+			break;
+		}
+	}
+	uci_parse_error(ctx, *str, "unterminated \"");
+}
+
+/*
+ * parse a single quoted string argument from the command line
+ */
+static void parse_single_quote(struct uci_context *ctx, char **str, char **target)
+{
+	char c;
+	/* skip quote character */
+	*str += 1;
+
+	while ((c = **str)) {
+		switch(c) {
+		case '\'':
+			**target = 0;
+			*str += 1;
+			return;
+		default:
+			addc(target, str);
+		}
+	}
+	uci_parse_error(ctx, *str, "unterminated '");
+}
+
+/*
+ * parse a string from the command line and detect the quoting style
+ */
+static void parse_str(struct uci_context *ctx, char **str, char **target)
+{
+	do {
+		switch(**str) {
+		case '\'':
+			parse_single_quote(ctx, str, target);
+			break;
+		case '"':
+			parse_double_quote(ctx, str, target);
+			break;
+		case '#':
+			**str = 0;
+			/* fall through */
+		case 0:
+			goto done;
+		case '\\':
+			if (!parse_backslash(ctx, str))
+				continue;
+			/* fall through */
+		default:
+			addc(target, str);
+			break;
+		}
+	} while (**str && !isspace(**str));
+done:
+
+	/* 
+	 * if the string was unquoted and we've stopped at a whitespace
+	 * character, skip to the next one, because the whitespace will
+	 * be overwritten by a null byte here
+	 */
+	if (**str)
+		*str += 1;
+
+	/* terminate the parsed string */
+	**target = 0;
+}
+
+/*
+ * extract the next argument from the command line
+ */
+static char *next_arg(struct uci_context *ctx, char **str, bool required, bool name)
+{
+	char *val;
+	char *ptr;
+
+	val = ptr = *str;
+	skip_whitespace(ctx, str);
+	parse_str(ctx, str, &ptr);
+	if (!*val) {
+		if (required)
+			uci_parse_error(ctx, *str, "insufficient arguments");
+		goto done;
+	}
+
+	if (name && !uci_validate_name(val))
+		uci_parse_error(ctx, val, "invalid character in field");
+
+done:
+	return val;
+}
+
+int uci_parse_argument(struct uci_context *ctx, FILE *stream, char **str, char **result)
+{
+	UCI_HANDLE_ERR(ctx);
+	UCI_ASSERT(ctx, str != NULL);
+	UCI_ASSERT(ctx, result != NULL);
+
+	if (ctx->pctx) {
+		if (ctx->pctx->file != stream) {
+			ctx->internal = true;
+			uci_cleanup(ctx);
+		}
+	} else {
+		uci_alloc_parse_context(ctx);
+		ctx->pctx->file = stream;
+	}
+	if (!*str) {
+		uci_getln(ctx, 0);
+		*str = ctx->pctx->buf;
+	}
+
+	*result = next_arg(ctx, str, false, false);
+
+	return 0;
+}
+
+
+/*
+ * open a stream and go to the right position
+ *
+ * note: when opening for write and seeking to the beginning of
+ * the stream, truncate the file
+ */
+static FILE *uci_open_stream(struct uci_context *ctx, const char *filename, int pos, bool write, bool create)
+{
+	struct stat statbuf;
+	FILE *file = NULL;
+	int fd, ret;
+	int mode = (write ? O_RDWR : O_RDONLY);
+
+	if (create)
+		mode |= O_CREAT;
+
+	if (!write && ((stat(filename, &statbuf) < 0) ||
+		((statbuf.st_mode &  S_IFMT) != S_IFREG))) {
+		UCI_THROW(ctx, UCI_ERR_NOTFOUND);
+	}
+
+	fd = open(filename, mode, UCI_FILEMODE);
+	if (fd <= 0)
+		goto error;
+
+	if (flock(fd, (write ? LOCK_EX : LOCK_SH)) < 0)
+		goto error;
+
+	ret = lseek(fd, 0, pos);
+
+	if (ret < 0)
+		goto error;
+
+	file = fdopen(fd, (write ? "w+" : "r"));
+	if (file)
+		goto done;
+
+error:
+	UCI_THROW(ctx, UCI_ERR_IO);
+done:
+	return file;
+}
+
+static void uci_close_stream(FILE *stream)
+{
+	int fd;
+
+	if (!stream)
+		return;
+
+	fd = fileno(stream);
+	flock(fd, LOCK_UN);
+	fclose(stream);
+}
+
+