swconfig: improve failure reporting

Report the translated error to the user if a get/set netlink operation failed.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

package/network/config/swconfig/Makefile

@@ -8,7 +8,7 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=swconfig
-PKG_RELEASE:=10
+PKG_RELEASE:=11
 
 PKG_MAINTAINER:=Felix Fietkau <nbd@nbd.name>
 PKG_LICENSE:=GPL-2.0

package/network/config/swconfig/src/cli.c

@@ -335,10 +335,10 @@ int main(int argc, char **argv)
 		if(cvlan > -1)
 			cport = cvlan;
 
-		if(swlib_set_attr_string(dev, a, cport, cvalue) < 0)
+		retval = swlib_set_attr_string(dev, a, cport, cvalue);
+		if (retval < 0)
 		{
-			fprintf(stderr, "failed\n");
+			nl_perror(-retval, "Failed to set attribute");
-			retval = -1;
 			goto out;
 		}
 		break;
@@ -347,10 +347,10 @@ int main(int argc, char **argv)
 			val.port_vlan = cvlan;
 		if(cport > -1)
 			val.port_vlan = cport;
-		if(swlib_get_attr(dev, a, &val) < 0)
+		retval = swlib_get_attr(dev, a, &val);
+		if (retval < 0)
 		{
-			fprintf(stderr, "failed\n");
+			nl_perror(-retval, "Failed to get attribute");
-			retval = -1;
 			goto out;
 		}
 		print_attr_val(a, &val);