nexthop: Add netlink defines and enumerators for resilient NH groups

- RTM_NEWNEXTHOP et.al. that handle resilient groups will have a new nested
  attribute, NHA_RES_GROUP, whose elements are attributes NHA_RES_GROUP_*.

- RTM_NEWNEXTHOPBUCKET et.al. is a suite of new messages that will
  currently serve only for dumping of individual buckets of resilient next
  hop groups. For nexthop group buckets, these messages will carry a nested
  attribute NHA_RES_BUCKET, whose elements are attributes NHA_RES_BUCKET_*.

  There are several reasons why a new suite of messages is created for
  nexthop buckets instead of overloading the information on the existing
  RTM_{NEW,DEL,GET}NEXTHOP messages.

  First, a nexthop group can contain a large number of nexthop buckets (4k
  is not unheard of). This imposes limits on the amount of information that
  can be encoded for each nexthop bucket given a netlink message is limited
  to 64k bytes.

  Second, while RTM_NEWNEXTHOPBUCKET is only used for notifications at
  this point, in the future it can be extended to provide user space with
  control over nexthop buckets configuration.

- The new group type is NEXTHOP_GRP_TYPE_RES. Note that nexthop code is
  adjusted to bounce groups with that type for now.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 53 insertions, 1 deletions

diff --git a/include/uapi/linux/nexthop.h b/include/uapi/linux/nexthop.h
index 2d4a1e784cf0..d8ffa8c9ca78 100644
--- a/include/uapi/linux/nexthop.h
+++ b/include/uapi/linux/nexthop.h
@@ -21,7 +21,10 @@ struct nexthop_grp {
 };
 
 enum {
-	NEXTHOP_GRP_TYPE_MPATH,  /* default type if not specified */
+	NEXTHOP_GRP_TYPE_MPATH,  /* hash-threshold nexthop group
+				  * default type if not specified
+				  */
+	NEXTHOP_GRP_TYPE_RES,    /* resilient nexthop group */
 	__NEXTHOP_GRP_TYPE_MAX,
 };
 
@@ -52,8 +55,50 @@ enum {
 	NHA_FDB,	/* flag; nexthop belongs to a bridge fdb */
 	/* if NHA_FDB is added, OIF, BLACKHOLE, ENCAP cannot be set */
 
+	/* nested; resilient nexthop group attributes */
+	NHA_RES_GROUP,
+	/* nested; nexthop bucket attributes */
+	NHA_RES_BUCKET,
+
 	__NHA_MAX,
 };
 
 #define NHA_MAX	(__NHA_MAX - 1)
+
+enum {
+	NHA_RES_GROUP_UNSPEC,
+	/* Pad attribute for 64-bit alignment. */
+	NHA_RES_GROUP_PAD = NHA_RES_GROUP_UNSPEC,
+
+	/* u16; number of nexthop buckets in a resilient nexthop group */
+	NHA_RES_GROUP_BUCKETS,
+	/* clock_t as u32; nexthop bucket idle timer (per-group) */
+	NHA_RES_GROUP_IDLE_TIMER,
+	/* clock_t as u32; nexthop unbalanced timer */
+	NHA_RES_GROUP_UNBALANCED_TIMER,
+	/* clock_t as u64; nexthop unbalanced time */
+	NHA_RES_GROUP_UNBALANCED_TIME,
+
+	__NHA_RES_GROUP_MAX,
+};
+
+#define NHA_RES_GROUP_MAX	(__NHA_RES_GROUP_MAX - 1)
+
+enum {
+	NHA_RES_BUCKET_UNSPEC,
+	/* Pad attribute for 64-bit alignment. */
+	NHA_RES_BUCKET_PAD = NHA_RES_BUCKET_UNSPEC,
+
+	/* u16; nexthop bucket index */
+	NHA_RES_BUCKET_INDEX,
+	/* clock_t as u64; nexthop bucket idle time */
+	NHA_RES_BUCKET_IDLE_TIME,
+	/* u32; nexthop id assigned to the nexthop bucket */
+	NHA_RES_BUCKET_NH_ID,
+
+	__NHA_RES_BUCKET_MAX,
+};
+
+#define NHA_RES_BUCKET_MAX	(__NHA_RES_BUCKET_MAX - 1)
+
 #endif
diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h
index 91e4ca064d61..d35953bc7d53 100644
--- a/include/uapi/linux/rtnetlink.h
+++ b/include/uapi/linux/rtnetlink.h
@@ -178,6 +178,13 @@ enum {
 	RTM_GETVLAN,
 #define RTM_GETVLAN	RTM_GETVLAN
 
+	RTM_NEWNEXTHOPBUCKET = 116,
+#define RTM_NEWNEXTHOPBUCKET	RTM_NEWNEXTHOPBUCKET
+	RTM_DELNEXTHOPBUCKET,
+#define RTM_DELNEXTHOPBUCKET	RTM_DELNEXTHOPBUCKET
+	RTM_GETNEXTHOPBUCKET,
+#define RTM_GETNEXTHOPBUCKET	RTM_GETNEXTHOPBUCKET
+
 	__RTM_MAX,
 #define RTM_MAX		(((__RTM_MAX + 3) & ~3) - 1)
 };