Use common is_ctrl_char() helper function

This modifies couple of code segments that replaced control characters
in strings with '_' to use a common helper function.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>

src/p2p/p2p_parse.c

@@ -161,8 +161,7 @@ static int p2p_parse_attribute(u8 id, const u8 *data, u16 len,
 		for (i = 0; i < nlen; i++) {
 			if (msg->device_name[i] == '\0')
 				break;
-			if (msg->device_name[i] > 0 &&
-			    msg->device_name[i] < 32)
+			if (is_ctrl_char(msg->device_name[i]))
 				msg->device_name[i] = '_';
 		}
 		wpa_printf(MSG_DEBUG, "P2P: * Device Info: addr " MACSTR
@@ -743,7 +742,7 @@ static int p2p_group_info_text(const u8 *gi, size_t gi_len, char *buf,
 		name[cli->dev_name_len] = '\0';
 		count = (int) cli->dev_name_len - 1;
 		while (count >= 0) {
-			if (name[count] > 0 && name[count] < 32)
+			if (is_ctrl_char(name[count]))
 				name[count] = '_';
 			count--;
 		}

src/utils/common.c

@@ -1088,3 +1088,9 @@ size_t utf8_escape(const char *inp, size_t in_size,
 
 	return res_size;
 }
+
+
+int is_ctrl_char(char c)
+{
+	return c > 0 && c < 32;
+}

src/utils/common.h

@@ -554,6 +554,7 @@ size_t utf8_escape(const char *inp, size_t in_size,
 		   char *outp, size_t out_size);
 size_t utf8_unescape(const char *inp, size_t in_size,
 		     char *outp, size_t out_size);
+int is_ctrl_char(char c);
 
 
 /*

src/wps/wps.c

@@ -618,7 +618,8 @@ int wps_attr_text(struct wpabuf *data, char *buf, char *end)
 		if (str == NULL)
 			return pos - buf;
 		for (i = 0; i < attr.dev_name_len; i++) {
-			if (attr.dev_name[i] < 32)
+			if (attr.dev_name[i] == 0 ||
+			    is_ctrl_char(attr.dev_name[i]))
 				str[i] = '_';
 			else
 				str[i] = attr.dev_name[i];