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>

diff --git a/include/uapi/linux/nexthop.h b/include/uapi/linux/nexthop.h
index 2d4a1e7..d8ffa8c 100644 (file)
--- 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 91e4ca0..d35953b 100644 (file)
--- 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)
 };

diff --git a/net/ipv4/nexthop.c b/net/ipv4/nexthop.c
index 56c54d0..7a94591 100644 (file)
--- a/net/ipv4/nexthop.c
+++ b/net/ipv4/nexthop.c
@@ -1492,6 +1492,8 @@ static struct nexthop *nexthop_create_group(struct net *net,
        if (cfg->nh_grp_type == NEXTHOP_GRP_TYPE_MPATH) {
                nhg->mpath = 1;
                nhg->is_multipath = true;
+       } else if (cfg->nh_grp_type == NEXTHOP_GRP_TYPE_RES) {
+               goto out_no_nh;
        }
 
        WARN_ON_ONCE(nhg->mpath != 1);

diff --git a/security/selinux/nlmsgtab.c b/security/selinux/nlmsgtab.c
index b692319..d59276f 100644 (file)
--- a/security/selinux/nlmsgtab.c
+++ b/security/selinux/nlmsgtab.c
@@ -88,6 +88,9 @@ static const struct nlmsg_perm nlmsg_route_perms[] =
        { RTM_NEWVLAN,          NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
        { RTM_DELVLAN,          NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
        { RTM_GETVLAN,          NETLINK_ROUTE_SOCKET__NLMSG_READ  },
+       { RTM_NEWNEXTHOPBUCKET, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
+       { RTM_DELNEXTHOPBUCKET, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
+       { RTM_GETNEXTHOPBUCKET, NETLINK_ROUTE_SOCKET__NLMSG_READ  },
 };
 
 static const struct nlmsg_perm nlmsg_tcpdiag_perms[] =
@@ -171,7 +174,7 @@ int selinux_nlmsg_lookup(u16 sclass, u16 nlmsg_type, u32 *perm)
                 * structures at the top of this file with the new mappings
                 * before updating the BUILD_BUG_ON() macro!
                 */
-               BUILD_BUG_ON(RTM_MAX != (RTM_NEWVLAN + 3));
+               BUILD_BUG_ON(RTM_MAX != (RTM_NEWNEXTHOPBUCKET + 3));
                err = nlmsg_perm(nlmsg_type, perm, nlmsg_route_perms,
                                 sizeof(nlmsg_route_perms));
                break;