common: add universal safe functions for string to number conversion

Knot.files

@@ -83,6 +83,7 @@ src/common/slab/slab.c
 src/common/slab/slab.h
 src/common/sockaddr.c
 src/common/sockaddr.h
+src/common/strtonum.h
 src/knot/conf/cf-lex.l
 src/knot/conf/cf-parse.y
 src/knot/conf/conf.c

src/Makefile.am

@@ -234,7 +234,8 @@ libknots_la_SOURCES =				\
 	common/hattrie/murmurhash3.c		\
 	common/hattrie/murmurhash3.h		\
 	common/hex.c				\
-	common/hex.h
+	common/hex.h				\
+	common/strtonum.h
 
 libknotd_la_SOURCES =				\
 	knot/stat/gatherer.c			\

src/common/strtonum.h

+/*  Copyright (C) 2011 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/*!
+ * \file strtonum.h
+ *
+ * \brief Universal interface for save conversion of strings to numbers.
+ *
+ * \author Jan Vcelak <jan.vcelak@nic.cz>
+ *
+ * \addtogroup common_lib
+ * @{
+ */
+
+#ifndef _KNOT_COMMON_STRTONUM_
+#define _KNOT_COMMON_STRTONUM_
+
+#include <limits.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include "common/errcode.h"
+
+typedef long long int knot_strtoll_result_t;
+typedef unsigned long long int knot_strtoull_result_t;
+
+/*!
+ * \brief Convert string to signed integer.
+ *
+ * \param[in]  src   Input string.
+ * \param[out] dest  Output integral value.
+ *
+ * \return Error code.
+ * \retval KNOT_EOK     The conversion was successful.
+ * \retval KNOT_ERANGE  The value is outside target type range.
+ * \retval KNOT_EMALF   The input value is not terminated.
+ */
+static int knot_strtoll(const char *src, knot_strtoll_result_t *dest)
+{
+	char *end;
+	knot_strtoll_result_t result = strtoll(src, &end, 10);
+	if (errno == ERANGE)
+		return KNOT_ERANGE;
+
+	if (src == end || *end != '\0')
+		return KNOT_EMALF;
+
+	*dest = result;
+	return KNOT_EOK;
+}
+
+/*!
+ * \brief Convert string to unsigned integer.
+ *
+ * \see knot_strtoll
+ */
+static int knot_strtoull(const char *src, knot_strtoull_result_t *dest)
+{
+	char *end;
+	knot_strtoull_result_t result = strtoull(src, &end, 10);
+	if (errno == ERANGE)
+		return KNOT_ERANGE;
+
+	if (src == end || *end != '\0')
+		return KNOT_EMALF;
+
+	*dest = result;
+	return KNOT_EOK;
+}
+
+/*!
+ * \brief Helper macro defining body of individual conversion functions.
+ *
+ * \param type      Target data type.
+ * \param function  Underlying conversion function.
+ * \param min       Minimal value valid for given data type.
+ * \param max       Maximal value valid for given data type.
+ * \param src       Pointer to source string.
+ * \param dest      Pointer to destination type.
+ *
+ * \return Error code.
+ * \retval KNOT_EOK     The conversion was successful.
+ * \retval KNOT_ERANGE  The value is outside target type range.
+ * \retval KNOT_EMALF   The input value is not terminated.
+ */
+#define KNOT_STR2NUM(type, function, min, max, src, dest) \
+{                                                         \
+	function##_result_t value;                        \
+	errno = 0;                                        \
+	int result = function((src), &value);             \
+	if (result != KNOT_EOK)                           \
+		return result;                            \
+	                                                  \
+	if (value < (min) || value > (max))               \
+		return KNOT_ERANGE;                       \
+	                                                  \
+	*(dest) = (type)value;                            \
+	return KNOT_EOK;                                  \
+}
+
+inline static int knot_str2int(const char *src, int *dest)
+{
+	KNOT_STR2NUM(int, knot_strtoll, INT_MIN, INT_MAX, src, dest)
+}
+
+inline static int knot_str2uint8t(const char *src, uint8_t *dest)
+{
+	KNOT_STR2NUM(uint8_t, knot_strtoull, 0, UINT8_MAX, src, dest)
+}
+
+inline static int knot_str2uint16t(const char *src, uint16_t *dest)
+{
+	KNOT_STR2NUM(uint16_t, knot_strtoull, 0, UINT16_MAX, src, dest)
+}
+
+#endif // _KNOT_COMMON_STRTONUM_
+/*! @} */