[PATCH V2 net-next 1/5] icmp: add support for RFC 8335 PROBE

[Andreas Roeseler <andreas.a.roeseler@gmail.com>]

Add definitions for PROBE ICMP types and codes.

Add AFI definitions for IP and IPV6 as specified by IANA

Add a struct to represent the additional header when probing by IP
address (ctype == 3) for use in parsing incoming PROBE messages.

Signed-off-by: Andreas Roeseler <andreas.a.roeseler@gmail.com>
---
Changes since v1:
 - Add AFI_IP and AFI_IP6 definitions
---
 include/uapi/linux/icmp.h | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/include/uapi/linux/icmp.h b/include/uapi/linux/icmp.h
index fb169a50895e..e70bfcc06247 100644
--- a/include/uapi/linux/icmp.h
+++ b/include/uapi/linux/icmp.h
@@ -66,6 +66,23 @@
 #define ICMP_EXC_TTL		0	/* TTL count exceeded		*/
 #define ICMP_EXC_FRAGTIME	1	/* Fragment Reass time exceeded	*/
 
+/* Codes for EXT_ECHO (PROBE) */
+#define ICMP_EXT_ECHO		42
+#define ICMP_EXT_ECHOREPLY	43
+#define ICMP_EXT_MAL_QUERY	1	/* Malformed Query */
+#define ICMP_EXT_NO_IF		2	/* No such Interface */
+#define ICMP_EXT_NO_TABLE_ENT	3	/* No such Table Entry */
+#define ICMP_EXT_MULT_IFS	4	/* Multiple Interfaces Satisfy Query */
+
+/* constants for EXT_ECHO (PROBE) */
+#define EXT_ECHOREPLY_ACTIVE	(1 << 2)/* position of active flag in reply */
+#define EXT_ECHOREPLY_IPV4	(1 << 1)/* position of ipv4 flag in reply */
+#define EXT_ECHOREPLY_IPV6	1	/* position of ipv6 flag in reply */
+#define CTYPE_NAME		1
+#define CTYPE_INDEX		2
+#define CTYPE_ADDR		3
+#define AFI_IP			1	/* Address Family Identifier for IPV4 */
+#define AFI_IP6			2	/* Address Family Identifier for IPV6 */
 
 struct icmphdr {
   __u8		type;
@@ -118,4 +135,11 @@ struct icmp_extobj_hdr {
 	__u8		class_type;
 };
 
+/* RFC 8335: 2.1 Header for C-type 3 payload */
+struct icmp_ext_ctype3_hdr {
+	__u16		afi;
+	__u8		addrlen;
+	__u8		reserved;
+};
+
 #endif /* _UAPI_LINUX_ICMP_H */
-- 
2.25.1