Merge branch 'Support-for-fdb-ECMP-nexthop-groups'

Roopa Prabhu says: ==================== Support for fdb ECMP nexthop groups This series introduces ecmp nexthops and nexthop groups for mac fdb entries. In subsequent patches this is used by the vxlan driver fdb entries. The use case is E-VPN multihoming [1,2,3] which requires bridged vxlan traffic to be load balanced to remote switches (vteps) belonging to the same multi-homed ethernet segment (This is analogous to a multi-homed LAG but over vxlan). Changes include new nexthop flag NHA_FDB for nexthops referenced by fdb entries. These nexthops only have ip. The patches make sure that routes dont reference such nexthops. example: $ip nexthop add id 12 via 172.16.1.2 fdb $ip nexthop add id 13 via 172.16.1.3 fdb $ip nexthop add id 102 group 12/13 fdb $bridge fdb add 02:02:00:00:00:13 dev vxlan1000 nhid 101 self [1] E-VPN https://tools.ietf.org/html/rfc7432 [2] E-VPN VxLAN: https://tools.ietf.org/html/rfc8365 [3] LPC talk with mention of nexthop groups for L2 ecmp http://vger.kernel.org/lpc_net2018_talks/scaling_bridge_fdb_database_slidesV3.pdf v4 - - fix error path free_skb in vxlan_xmit_nh - fix atomic notifier initialization issue (Reported-by: kernel test robot <rong.a.chen@intel.com>) The reported error was easy to locate and fix, but i was not able to re-test with the robot reproducer script due to some other issues with running the script on my test system. v3 - fix wording in selftest print as pointed out by davidA v2 - - dropped nikolays fixes for nexthop multipath null pointer deref (he will send those separately) - added negative tests for route add with fdb nexthop + a few more - Fixes for a few fdb replace conditions found during more testing - Moved to rcu_dereference_rtnl in vxlan_fdb_info and consolidate rcu dereferences - Fixes to build failures Reported-by: kbuild test robot <lkp@intel.com> - DavidA, I am going to send a separate patch for the neighbor code validation for NDA_NH_ID if thats ok. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
mariux64 · May 22, 2020 · 4001f1f · 4001f1f
2 parents 7b1b843 + 0534c54
commit 4001f1f
Show file tree

Hide file tree

Showing 11 changed files with 650 additions and 90 deletions.
diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h
@@ -65,6 +65,7 @@ struct fib6_config {
 	struct nl_info	fc_nlinfo;
 	struct nlattr	*fc_encap;
 	u16		fc_encap_type;
+	bool		fc_is_fdb;
 };
 
 struct fib6_node {

diff --git a/include/net/netns/nexthop.h b/include/net/netns/nexthop.h
@@ -14,5 +14,6 @@ struct netns_nexthop {
 
 	unsigned int		seq;		/* protected by rtnl_mutex */
 	u32			last_id_allocated;
+	struct atomic_notifier_head notifier_chain;
 };
 #endif
diff --git a/include/net/nexthop.h b/include/net/nexthop.h
@@ -10,6 +10,7 @@
 #define __LINUX_NEXTHOP_H
 
 #include <linux/netdevice.h>
+#include <linux/notifier.h>
 #include <linux/route.h>
 #include <linux/types.h>
 #include <net/ip_fib.h>
@@ -26,6 +27,7 @@ struct nh_config {
 	u8		nh_family;
 	u8		nh_protocol;
 	u8		nh_blackhole;
+	u8		nh_fdb;
 	u32		nh_flags;
 
 	int		nh_ifindex;
@@ -52,6 +54,7 @@ struct nh_info {
 
 	u8			family;
 	bool			reject_nh;
+	bool			fdb_nh;
 
 	union {
 		struct fib_nh_common	fib_nhc;
@@ -80,6 +83,7 @@ struct nexthop {
 	struct rb_node		rb_node;    /* entry on netns rbtree */
 	struct list_head	fi_list;    /* v4 entries using nh */
 	struct list_head	f6i_list;   /* v6 entries using nh */
+	struct list_head        fdb_list;   /* fdb entries using this nh */
 	struct list_head	grp_list;   /* nh group entries using this nh */
 	struct net		*net;
 
@@ -88,6 +92,7 @@ struct nexthop {
 	u8			protocol;   /* app managing this nh */
 	u8			nh_flags;
 	bool			is_group;
+	bool			is_fdb_nh;
 
 	refcount_t		refcnt;
 	struct rcu_head		rcu;
@@ -98,6 +103,17 @@ struct nexthop {
 	};
 };
 
+enum nexthop_event_type {
+	NEXTHOP_EVENT_ADD,
+	NEXTHOP_EVENT_DEL
+};
+
+int call_nexthop_notifier(struct notifier_block *nb, struct net *net,
+			  enum nexthop_event_type event_type,
+			  struct nexthop *nh);
+int register_nexthop_notifier(struct net *net, struct notifier_block *nb);
+int unregister_nexthop_notifier(struct net *net, struct notifier_block *nb);
+
 /* caller is holding rcu or rtnl; no reference taken to nexthop */
 struct nexthop *nexthop_find_by_id(struct net *net, u32 id);
 void nexthop_free_rcu(struct rcu_head *head);
@@ -304,4 +320,32 @@ static inline void nexthop_path_fib6_result(struct fib6_result *res, int hash)
 int nexthop_for_each_fib6_nh(struct nexthop *nh,
 			     int (*cb)(struct fib6_nh *nh, void *arg),
 			     void *arg);
+
+static inline int nexthop_get_family(struct nexthop *nh)
+{
+	struct nh_info *nhi = rcu_dereference_rtnl(nh->nh_info);
+
+	return nhi->family;
+}
+
+static inline
+struct fib_nh_common *nexthop_fdb_nhc(struct nexthop *nh)
+{
+	struct nh_info *nhi = rcu_dereference_rtnl(nh->nh_info);
+
+	return &nhi->fib_nhc;
+}
+
+static inline struct fib_nh_common *nexthop_path_fdb_result(struct nexthop *nh,
+							    int hash)
+{
+	struct nh_info *nhi;
+	struct nexthop *nhp;
+
+	nhp = nexthop_select_path(nh, hash);
+	if (unlikely(!nhp))
+		return NULL;
+	nhi = rcu_dereference(nhp->nh_info);
+	return &nhi->fib_nhc;
+}
 #endif
diff --git a/include/net/vxlan.h b/include/net/vxlan.h
@@ -7,6 +7,7 @@
 #include <net/dst_metadata.h>
 #include <net/rtnetlink.h>
 #include <net/switchdev.h>
+#include <net/nexthop.h>
 
 #define IANA_VXLAN_UDP_PORT     4789
 
@@ -487,4 +488,28 @@ static inline void vxlan_flag_attr_error(int attrtype,
 #undef VXLAN_FLAG
 }
 
+static inline bool vxlan_fdb_nh_path_select(struct nexthop *nh,
+					    int hash,
+					    struct vxlan_rdst *rdst)
+{
+	struct fib_nh_common *nhc;
+
+	nhc = nexthop_path_fdb_result(nh, hash);
+	if (unlikely(!nhc))
+		return false;
+
+	switch (nhc->nhc_gw_family) {
+	case AF_INET:
+		rdst->remote_ip.sin.sin_addr.s_addr = nhc->nhc_gw.ipv4;
+		rdst->remote_ip.sa.sa_family = AF_INET;
+		break;
+	case AF_INET6:
+		rdst->remote_ip.sin6.sin6_addr = nhc->nhc_gw.ipv6;
+		rdst->remote_ip.sa.sa_family = AF_INET6;
+		break;
+	}
+
+	return true;
+}
+
 #endif
diff --git a/include/uapi/linux/neighbour.h b/include/uapi/linux/neighbour.h
@@ -29,6 +29,7 @@ enum {
 	NDA_LINK_NETNSID,
 	NDA_SRC_VNI,
 	NDA_PROTOCOL,  /* Originator of entry */
+	NDA_NH_ID,
 	__NDA_MAX
 };
 

diff --git a/include/uapi/linux/nexthop.h b/include/uapi/linux/nexthop.h
@@ -49,6 +49,9 @@ enum {
 	NHA_GROUPS,	/* flag; only return nexthop groups in dump */
 	NHA_MASTER,	/* u32;  only return nexthops with given master dev */
 
+	NHA_FDB,	/* flag; nexthop belongs to a bridge fdb */
+	/* if NHA_FDB is added, OIF, BLACKHOLE, ENCAP cannot be set */
+
 	__NHA_MAX,
 };
 

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
@@ -1771,6 +1771,7 @@ static struct neigh_table *neigh_find_table(int family)
 }
 
 const struct nla_policy nda_policy[NDA_MAX+1] = {
+	[NDA_UNSPEC]		= { .strict_start_type = NDA_NH_ID },
 	[NDA_DST]		= { .type = NLA_BINARY, .len = MAX_ADDR_LEN },
 	[NDA_LLADDR]		= { .type = NLA_BINARY, .len = MAX_ADDR_LEN },
 	[NDA_CACHEINFO]		= { .len = sizeof(struct nda_cacheinfo) },
@@ -1781,6 +1782,7 @@ const struct nla_policy nda_policy[NDA_MAX+1] = {
 	[NDA_IFINDEX]		= { .type = NLA_U32 },
 	[NDA_MASTER]		= { .type = NLA_U32 },
 	[NDA_PROTOCOL]		= { .type = NLA_U8 },
+	[NDA_NH_ID]		= { .type = NLA_U32 },
 };
 
 static int neigh_delete(struct sk_buff *skb, struct nlmsghdr *nlh,