Thread (11 messages) flat view 11 messages, 3 authors, 2021-02-25

Re: [PATCH V3 net-next 1/5] icmp: add support for RFC 8335 PROBE

From: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Date: 2021-02-22 04:43:58

On Wed, Feb 17, 2021 at 1:10 PM Andreas Roeseler
[off-list ref] wrote:
quoted hunk ↗ jump to hunk
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.

Add a struct to represent the entire Interface Identification Object
(IIO) section of an incoming PROBE packet

Signed-off-by: Andreas Roeseler <redacted>
---
Changes since v1:
 - Add AFI_IP and AFI_IP6 definitions

Changes since v2:
Suggested by Willem de Brujin [off-list ref]
 - Add prefix for PROBE specific defined variables
 - Create struct icmp_ext_echo_iio for parsing incoming packet
---
 include/uapi/linux/icmp.h | 40 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)
diff --git a/include/uapi/linux/icmp.h b/include/uapi/linux/icmp.h
index fb169a50895e..166ca77561de 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 EXT_ECHO_CTYPE_NAME    1
+#define EXT_ECHO_CTYPE_INDEX   2
+#define EXT_ECHO_CTYPE_ADDR    3
+#define EXT_ECHO_AFI_IP                1       /* Address Family Identifier for IPV4 */
+#define EXT_ECHO_AFI_IP6       2       /* Address Family Identifier for IPV6 */

 struct icmphdr {
   __u8         type;
@@ -118,4 +135,27 @@ struct icmp_extobj_hdr {
        __u8            class_type;
 };

+/* RFC 8335: 2.1 Header for C-type 3 payload */
+struct icmp_ext_echo_ctype3_hdr {
+       __u16           afi;
+       __u8            addrlen;
+       __u8            reserved;
+};
+
+/* RFC 8335: Interface Identification Object */
+struct icmp_ext_echo_iio {
+       struct icmp_extobj_hdr  extobj_hdr;
+       union {
+               __u32   ifIndex;
please no camelcase.
+               char name;
why single char?
+               struct {
+                       struct icmp_ext_echo_ctype3_hdr ctype3_hdr;
+                       union {
+                               __be32          ipv4_addr;
perhaps struct in_addr
+                               struct in6_addr ipv6_addr;
+                       } ip_addr;
+               } addr;
+       } ident;
+};
+
 #endif /* _UAPI_LINUX_ICMP_H */
--
2.25.1
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