ipv6: ioam: move the check for undefined bits

The check for undefined bits in the trace type is moved from the input side to
the output side, while the input side is relaxed and now inserts default empty
values when an undefined bit is set.
Signed-off-by: Justin Iurman <justin.iurman@uliege.be>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv6/ioam6.c

@@ -770,6 +770,66 @@ static void __ioam6_fill_trace_data(struct sk_buff *skb,
 		data += sizeof(__be32);
 	}
 
+	/* bit12 undefined: filled with empty value */
+	if (trace->type.bit12) {
+		*(__be32 *)data = cpu_to_be32(IOAM6_U32_UNAVAILABLE);
+		data += sizeof(__be32);
+	}
+
+	/* bit13 undefined: filled with empty value */
+	if (trace->type.bit13) {
+		*(__be32 *)data = cpu_to_be32(IOAM6_U32_UNAVAILABLE);
+		data += sizeof(__be32);
+	}
+
+	/* bit14 undefined: filled with empty value */
+	if (trace->type.bit14) {
+		*(__be32 *)data = cpu_to_be32(IOAM6_U32_UNAVAILABLE);
+		data += sizeof(__be32);
+	}
+
+	/* bit15 undefined: filled with empty value */
+	if (trace->type.bit15) {
+		*(__be32 *)data = cpu_to_be32(IOAM6_U32_UNAVAILABLE);
+		data += sizeof(__be32);
+	}
+
+	/* bit16 undefined: filled with empty value */
+	if (trace->type.bit16) {
+		*(__be32 *)data = cpu_to_be32(IOAM6_U32_UNAVAILABLE);
+		data += sizeof(__be32);
+	}
+
+	/* bit17 undefined: filled with empty value */
+	if (trace->type.bit17) {
+		*(__be32 *)data = cpu_to_be32(IOAM6_U32_UNAVAILABLE);
+		data += sizeof(__be32);
+	}
+
+	/* bit18 undefined: filled with empty value */
+	if (trace->type.bit18) {
+		*(__be32 *)data = cpu_to_be32(IOAM6_U32_UNAVAILABLE);
+		data += sizeof(__be32);
+	}
+
+	/* bit19 undefined: filled with empty value */
+	if (trace->type.bit19) {
+		*(__be32 *)data = cpu_to_be32(IOAM6_U32_UNAVAILABLE);
+		data += sizeof(__be32);
+	}
+
+	/* bit20 undefined: filled with empty value */
+	if (trace->type.bit20) {
+		*(__be32 *)data = cpu_to_be32(IOAM6_U32_UNAVAILABLE);
+		data += sizeof(__be32);
+	}
+
+	/* bit21 undefined: filled with empty value */
+	if (trace->type.bit21) {
+		*(__be32 *)data = cpu_to_be32(IOAM6_U32_UNAVAILABLE);
+		data += sizeof(__be32);
+	}
+
 	/* opaque state snapshot */
 	if (trace->type.bit22) {
 		if (!sc) {
@@ -791,16 +851,10 @@ void ioam6_fill_trace_data(struct sk_buff *skb,
 	struct ioam6_schema *sc;
 	u8 sclen = 0;
 
-	/* Skip if Overflow flag is set OR
-	 * if an unknown type (bit 12-21) is set
+	/* Skip if Overflow flag is set
 	 */
-	if (trace->overflow ||
-	    trace->type.bit12 | trace->type.bit13 | trace->type.bit14 |
-	    trace->type.bit15 | trace->type.bit16 | trace->type.bit17 |
-	    trace->type.bit18 | trace->type.bit19 | trace->type.bit20 |
-	    trace->type.bit21) {
+	if (trace->overflow)
 		return;
-	}
 
 	/* NodeLen does not include Opaque State Snapshot length. We need to
 	 * take it into account if the corresponding bit is set (bit 22) and

net/ipv6/ioam6_iptunnel.c

@@ -75,7 +75,11 @@ static bool ioam6_validate_trace_hdr(struct ioam6_trace_hdr *trace)
 	u32 fields;
 
 	if (!trace->type_be32 || !trace->remlen ||
-	    trace->remlen > IOAM6_TRACE_DATA_SIZE_MAX / 4)
+	    trace->remlen > IOAM6_TRACE_DATA_SIZE_MAX / 4 ||
+	    trace->type.bit12 | trace->type.bit13 | trace->type.bit14 |
+	    trace->type.bit15 | trace->type.bit16 | trace->type.bit17 |
+	    trace->type.bit18 | trace->type.bit19 | trace->type.bit20 |
+	    trace->type.bit21)
 		return false;
 
 	trace->nodelen = 0;