From 1ac34884c1cc4e808674d8901c97e31776e8fc5c Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@openwrt.org>
Date: Mon, 4 Feb 2008 23:51:08 +0100
Subject: [PATCH] export a function for parsing shell-style arguments in libuci

---
 file.c | 161 +---------------------------------------------------
 uci.h  |   8 +++
 util.c | 175 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 3 files changed, 183 insertions(+), 161 deletions(-)

diff --git a/file.c b/file.c
index bc6b5a9..4f1392e 100644
--- a/file.c
+++ b/file.c
@@ -53,165 +53,6 @@ static void uci_file_cleanup(struct uci_context *ctx)
 }
 
 
-/* 
- * 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;
-}
-
 /*
  * verify that the end of the line or command is reached.
  * throw an error if extra arguments are given on the command line
@@ -221,7 +62,7 @@ static void assert_eol(struct uci_context *ctx, char **str)
 	char *tmp;
 
 	tmp = next_arg(ctx, str, false, false);
-	if (tmp && *tmp && (ctx->flags & UCI_FLAG_STRICT))
+	if (*tmp && (ctx->flags & UCI_FLAG_STRICT))
 		uci_parse_error(ctx, *str, "too many arguments");
 }
 
diff --git a/uci.h b/uci.h
index 8e73bfe..8a89b71 100644
--- a/uci.h
+++ b/uci.h
@@ -260,6 +260,14 @@ extern int uci_add_history_path(struct uci_context *ctx, const char *dir);
  */
 extern int uci_revert(struct uci_context *ctx, struct uci_package **p, char *section, char *option);
 
+/**
+ * uci_parse_argument: parse a shell-style argument, with an arbitrary quoting style
+ * @ctx: uci context
+ * @str: pointer to the input string (will be changed to the end of the parsed string)
+ * @result: pointer for the result
+ */
+extern int uci_parse_argument(struct uci_context *ctx, char **str, char **result);
+
 /* UCI data structures */
 enum uci_type {
 	UCI_TYPE_HISTORY = 0,
diff --git a/util.c b/util.c
index 78b22cf..0ac33c7 100644
--- a/util.c
+++ b/util.c
@@ -146,7 +146,10 @@ 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;
+	if ((pos < pctx->buf) || (pos > pctx->buf + pctx->bufsz))
+		pctx->byte = 0;
+	else
+		pctx->byte = pos - pctx->buf;
 	UCI_THROW(ctx, UCI_ERR_PARSE);
 }
 
@@ -189,6 +192,176 @@ static void uci_getln(struct uci_context *ctx, int offset)
 	} 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, char **str, char **result)
+{
+	UCI_HANDLE_ERR(ctx);
+	UCI_ASSERT(ctx, (str != NULL) && (*str != NULL));
+	UCI_ASSERT(ctx, result != NULL);
+
+	*result = next_arg(ctx, str, false, false);
+	return 0;
+}
+
+
 /*
  * open a stream and go to the right position
  *
-- 
2.41.1