ut: add hex2string decoding

modules/aaa_diameter/dm_impl.c

@@ -2196,8 +2196,8 @@ static cJSON *dict_avp_dec_ip(struct avp_hdr * h, struct dict_avp_data *avp)
 
 static int dict_avp_enc_hex(cJSON *obj, struct dict_avp_data *avp, int _, str *ret)
 {
-	int len, i;
-	char *buf, *val;
+	int len;
+	char *buf;
 
 	if ((obj->type & cJSON_String) == 0)
 		return 1; /* encode it as it is */
@@ -2207,24 +2207,9 @@ static int dict_avp_enc_hex(cJSON *obj, struct dict_avp_data *avp, int _, str *r
 		LM_ERR("oom for hex encoding\n");
 		return -1;
 	}
-	val = obj->valuestring;
-	for (i = 0; i < len / 2; i++) {
-		if(val[2*i]>='0' && val[2*i]<='9')
-			buf[i] = (val[2*i]-'0') << 4;
-		else if(val[2*i]>='a' && val[2*i]<='f')
-			buf[i] = (val[2*i]-'a'+10) << 4;
-		else if(val[2*i]>='A' && val[2*i]<='F')
-			buf[i] = (val[2*i]-'A'+10) << 4;
-		else goto error;
-
-		if(val[2*i+1]>='0' && val[2*i+1]<='9')
-			buf[i] += val[2*i+1]-'0';
-		else if(val[2*i+1]>='a' && val[2*i+1]<='f')
-			buf[i] += val[2*i+1]-'a'+10;
-		else if(val[2*i+1]>='A' && val[2*i+1]<='F')
-			buf[i] += val[2*i+1]-'A'+10;
-		else goto error;
-	}
+	len = hex2string(obj->valuestring, len, buf);
+	if (len < 0)
+		goto error;
 	ret->s = buf;
 	ret->len = len/2;
 	return 0;

ut.h

@@ -472,6 +472,33 @@ inline static int string2hex(
 	return orig_len * 2;
 }
 
+inline static int hex2string(
+	/* input */ const char *str, int len,
+	/* output */ char *hex )
+{
+	int i;
+	for (i = 0; i < len / 2; i++) {
+		if(str[2*i]>='0' && str[2*i]<='9')
+			hex[i] = (str[2*i]-'0') << 4;
+		else if(str[2*i]>='a' && str[2*i]<='f')
+			hex[i] = (str[2*i]-'a'+10) << 4;
+		else if(str[2*i]>='A' && str[2*i]<='F')
+			hex[i] = (str[2*i]-'A'+10) << 4;
+		else goto error;
+
+		if(str[2*i+1]>='0' && str[2*i+1]<='9')
+			hex[i] += str[2*i+1]-'0';
+		else if(str[2*i+1]>='a' && str[2*i+1]<='f')
+			hex[i] += str[2*i+1]-'a'+10;
+		else if(str[2*i+1]>='A' && str[2*i+1]<='F')
+			hex[i] += str[2*i+1]-'A'+10;
+		else goto error;
+	}
+	return i;
+error:
+	return -1;
+}
+
 /* portable sleep in microseconds (no interrupt handling now) */
 
 inline static void sleep_us( unsigned int nusecs )