[NETFILTER]: Add more debug info to TFTP helper.

From Vineet Mehta <extreme@zayanionline.com>

include/linux/netfilter_ipv4/ip_conntrack_tftp.h

@@ -9,5 +9,8 @@ struct tftphdr {
 
 #define TFTP_OPCODE_READ	1
 #define TFTP_OPCODE_WRITE	2
+#define TFTP_OPCODE_DATA	3
+#define TFTP_OPCODE_ACK		4
+#define TFTP_OPCODE_ERROR	5
 
 #endif /* _IP_CT_TFTP */

net/ipv4/netfilter/ip_conntrack_tftp.c

@@ -71,6 +71,13 @@ static int tftp_help(struct sk_buff *skb,
 		DUMP_TUPLE(&exp.mask);
 		ip_conntrack_expect_related(ct, &exp);
 		break;
+	case TFTP_OPCODE_DATA:
+	case TFTP_OPCODE_ACK:
+		DEBUGP("Data/ACK opcode\n");
+		break;
+	case TFTP_OPCODE_ERROR:
+		DEBUGP("Error opcode\n");
+		break;
 	default:
 		DEBUGP("Unknown opcode\n");
 	}