conversions.c: Add conversions for largest max sized integer

Added a conversion for umax (largest maximum sized integer allowed). Adjusted
the other current conversion functions (uint and ulong) to be derivatives of
the umax conversion since they are simply subsets of umax.

Also made the negative check move the pointer on spaces since strtoumax does it
anyways.

Change-Id: I56c2ef2629d49b524c8df58af12951c181f81f08

main/conversions.c

@@ -26,22 +26,26 @@
 #include <ctype.h>
 #include <errno.h>
 #include <limits.h>
-#include <stdlib.h>
+#include <inttypes.h>
+#include <stdio.h>
 
 #include "asterisk/conversions.h"
 
-static int str_is_negative(const char *str)
+static int str_is_negative(const char **str)
 {
-	/* Ignore any preceding white space */
-	while (isspace(*str) && *++str);
-	return *str == '-';
+	/*
+	 * Ignore any preceding white space. It's okay to move the pointer here
+	 * since the converting function would do the same, i.e. skip white space.
+	 */
+	while (isspace(**str)) ++*str;
+	return **str == '-';
 }
 
 int ast_str_to_uint(const char *str, unsigned int *res)
 {
-	unsigned long val;
+	uintmax_t val;
 
-	if (ast_str_to_ulong(str, &val) || val > UINT_MAX) {
+	if (ast_str_to_umax(str, &val) || val > UINT_MAX) {
 		return -1;
 	}
 
@@ -51,15 +55,27 @@ int ast_str_to_uint(const char *str, unsigned int *res)
 
 int ast_str_to_ulong(const char *str, unsigned long *res)
 {
-	char *end;
-	unsigned long val;
+	uintmax_t val;
 
-	if (!str || str_is_negative(str)) {
+	if (ast_str_to_umax(str, &val) || val > ULONG_MAX) {
+		return -1;
+	}
+
+	*res = val;
+	return 0;
+}
+
+int ast_str_to_umax(const char *str, uintmax_t *res)
+{
+	char *end;
+	uintmax_t val;
+
+	if (!str || str_is_negative(&str)) {
 		return -1;
 	}
 
 	errno = 0;
-	val = strtoul(str, &end, 0);
+	val = strtoumax(str, &end, 0);
 
 	/*
 	 * If str equals end then no digits were found. If end is not pointing to
@@ -67,11 +83,10 @@ int ast_str_to_ulong(const char *str, unsigned long *res)
 	 * converted, but some characters that could not, which we'll consider
 	 * invalid.
 	 */
-	if ((str == end || *end != '\0' || (errno == ERANGE && val == ULONG_MAX))) {
+	if ((str == end || *end != '\0' || (errno == ERANGE && val == UINTMAX_MAX))) {
 		return -1;
 	}
 
 	*res = val;
 	return 0;
-
 }