Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 465 insertions, 0 deletions

diff --git a/include/net/nexthop.h b/include/net/nexthop.h
new file mode 100644
index 000000000..fd87d727a
--- /dev/null
+++ b/include/net/nexthop.h
@@ -0,0 +1,465 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Generic nexthop implementation
+ *
+ * Copyright (c) 2017-19 Cumulus Networks
+ * Copyright (c) 2017-19 David Ahern <dsa@cumulusnetworks.com>
+ */
+
+#ifndef __LINUX_NEXTHOP_H
+#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>
+#include <net/ip6_fib.h>
+#include <net/netlink.h>
+
+#define NEXTHOP_VALID_USER_FLAGS RTNH_F_ONLINK
+
+struct nexthop;
+
+struct nh_config {
+	u32		nh_id;
+
+	u8		nh_family;
+	u8		nh_protocol;
+	u8		nh_blackhole;
+	u8		nh_fdb;
+	u32		nh_flags;
+
+	int		nh_ifindex;
+	struct net_device *dev;
+
+	union {
+		__be32		ipv4;
+		struct in6_addr	ipv6;
+	} gw;
+
+	struct nlattr	*nh_grp;
+	u16		nh_grp_type;
+
+	struct nlattr	*nh_encap;
+	u16		nh_encap_type;
+
+	u32		nlflags;
+	struct nl_info	nlinfo;
+};
+
+struct nh_info {
+	struct hlist_node	dev_hash;    /* entry on netns devhash */
+	struct nexthop		*nh_parent;
+
+	u8			family;
+	bool			reject_nh;
+	bool			fdb_nh;
+
+	union {
+		struct fib_nh_common	fib_nhc;
+		struct fib_nh		fib_nh;
+		struct fib6_nh		fib6_nh;
+	};
+};
+
+struct nh_grp_entry {
+	struct nexthop	*nh;
+	u8		weight;
+	atomic_t	upper_bound;
+
+	struct list_head nh_list;
+	struct nexthop	*nh_parent;  /* nexthop of group with this entry */
+};
+
+struct nh_group {
+	struct nh_group		*spare; /* spare group for removals */
+	u16			num_nh;
+	bool			mpath;
+	bool			fdb_nh;
+	bool			has_v4;
+	struct nh_grp_entry	nh_entries[];
+};
+
+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;
+
+	u32			id;
+
+	u8			protocol;   /* app managing this nh */
+	u8			nh_flags;
+	bool			is_group;
+
+	refcount_t		refcnt;
+	struct rcu_head		rcu;
+
+	union {
+		struct nh_info	__rcu *nh_info;
+		struct nh_group __rcu *nh_grp;
+	};
+};
+
+enum nexthop_event_type {
+	NEXTHOP_EVENT_DEL
+};
+
+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);
+
+static inline bool nexthop_get(struct nexthop *nh)
+{
+	return refcount_inc_not_zero(&nh->refcnt);
+}
+
+static inline void nexthop_put(struct nexthop *nh)
+{
+	if (refcount_dec_and_test(&nh->refcnt))
+		call_rcu(&nh->rcu, nexthop_free_rcu);
+}
+
+static inline bool nexthop_cmp(const struct nexthop *nh1,
+			       const struct nexthop *nh2)
+{
+	return nh1 == nh2;
+}
+
+static inline bool nexthop_is_fdb(const struct nexthop *nh)
+{
+	if (nh->is_group) {
+		const struct nh_group *nh_grp;
+
+		nh_grp = rcu_dereference_rtnl(nh->nh_grp);
+		return nh_grp->fdb_nh;
+	} else {
+		const struct nh_info *nhi;
+
+		nhi = rcu_dereference_rtnl(nh->nh_info);
+		return nhi->fdb_nh;
+	}
+}
+
+static inline bool nexthop_has_v4(const struct nexthop *nh)
+{
+	if (nh->is_group) {
+		struct nh_group *nh_grp;
+
+		nh_grp = rcu_dereference_rtnl(nh->nh_grp);
+		return nh_grp->has_v4;
+	}
+	return false;
+}
+
+static inline bool nexthop_is_multipath(const struct nexthop *nh)
+{
+	if (nh->is_group) {
+		struct nh_group *nh_grp;
+
+		nh_grp = rcu_dereference_rtnl(nh->nh_grp);
+		return nh_grp->mpath;
+	}
+	return false;
+}
+
+struct nexthop *nexthop_select_path(struct nexthop *nh, int hash);
+
+static inline unsigned int nexthop_num_path(const struct nexthop *nh)
+{
+	unsigned int rc = 1;
+
+	if (nh->is_group) {
+		struct nh_group *nh_grp;
+
+		nh_grp = rcu_dereference_rtnl(nh->nh_grp);
+		if (nh_grp->mpath)
+			rc = nh_grp->num_nh;
+	}
+
+	return rc;
+}
+
+static inline
+struct nexthop *nexthop_mpath_select(const struct nh_group *nhg, int nhsel)
+{
+	/* for_nexthops macros in fib_semantics.c grabs a pointer to
+	 * the nexthop before checking nhsel
+	 */
+	if (nhsel >= nhg->num_nh)
+		return NULL;
+
+	return nhg->nh_entries[nhsel].nh;
+}
+
+static inline
+int nexthop_mpath_fill_node(struct sk_buff *skb, struct nexthop *nh,
+			    u8 rt_family)
+{
+	struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
+	int i;
+
+	for (i = 0; i < nhg->num_nh; i++) {
+		struct nexthop *nhe = nhg->nh_entries[i].nh;
+		struct nh_info *nhi = rcu_dereference_rtnl(nhe->nh_info);
+		struct fib_nh_common *nhc = &nhi->fib_nhc;
+		int weight = nhg->nh_entries[i].weight;
+
+		if (fib_add_nexthop(skb, nhc, weight, rt_family, 0) < 0)
+			return -EMSGSIZE;
+	}
+
+	return 0;
+}
+
+/* called with rcu lock */
+static inline bool nexthop_is_blackhole(const struct nexthop *nh)
+{
+	const struct nh_info *nhi;
+
+	if (nh->is_group) {
+		struct nh_group *nh_grp;
+
+		nh_grp = rcu_dereference_rtnl(nh->nh_grp);
+		if (nh_grp->num_nh > 1)
+			return false;
+
+		nh = nh_grp->nh_entries[0].nh;
+	}
+
+	nhi = rcu_dereference_rtnl(nh->nh_info);
+	return nhi->reject_nh;
+}
+
+static inline void nexthop_path_fib_result(struct fib_result *res, int hash)
+{
+	struct nh_info *nhi;
+	struct nexthop *nh;
+
+	nh = nexthop_select_path(res->fi->nh, hash);
+	nhi = rcu_dereference(nh->nh_info);
+	res->nhc = &nhi->fib_nhc;
+}
+
+/* called with rcu read lock or rtnl held */
+static inline
+struct fib_nh_common *nexthop_fib_nhc(struct nexthop *nh, int nhsel)
+{
+	struct nh_info *nhi;
+
+	BUILD_BUG_ON(offsetof(struct fib_nh, nh_common) != 0);
+	BUILD_BUG_ON(offsetof(struct fib6_nh, nh_common) != 0);
+
+	if (nh->is_group) {
+		struct nh_group *nh_grp;
+
+		nh_grp = rcu_dereference_rtnl(nh->nh_grp);
+		if (nh_grp->mpath) {
+			nh = nexthop_mpath_select(nh_grp, nhsel);
+			if (!nh)
+				return NULL;
+		}
+	}
+
+	nhi = rcu_dereference_rtnl(nh->nh_info);
+	return &nhi->fib_nhc;
+}
+
+/* called from fib_table_lookup with rcu_lock */
+static inline
+struct fib_nh_common *nexthop_get_nhc_lookup(const struct nexthop *nh,
+					     int fib_flags,
+					     const struct flowi4 *flp,
+					     int *nhsel)
+{
+	struct nh_info *nhi;
+
+	if (nh->is_group) {
+		struct nh_group *nhg = rcu_dereference(nh->nh_grp);
+		int i;
+
+		for (i = 0; i < nhg->num_nh; i++) {
+			struct nexthop *nhe = nhg->nh_entries[i].nh;
+
+			nhi = rcu_dereference(nhe->nh_info);
+			if (fib_lookup_good_nhc(&nhi->fib_nhc, fib_flags, flp)) {
+				*nhsel = i;
+				return &nhi->fib_nhc;
+			}
+		}
+	} else {
+		nhi = rcu_dereference(nh->nh_info);
+		if (fib_lookup_good_nhc(&nhi->fib_nhc, fib_flags, flp)) {
+			*nhsel = 0;
+			return &nhi->fib_nhc;
+		}
+	}
+
+	return NULL;
+}
+
+static inline bool nexthop_uses_dev(const struct nexthop *nh,
+				    const struct net_device *dev)
+{
+	struct nh_info *nhi;
+
+	if (nh->is_group) {
+		struct nh_group *nhg = rcu_dereference(nh->nh_grp);
+		int i;
+
+		for (i = 0; i < nhg->num_nh; i++) {
+			struct nexthop *nhe = nhg->nh_entries[i].nh;
+
+			nhi = rcu_dereference(nhe->nh_info);
+			if (nhc_l3mdev_matches_dev(&nhi->fib_nhc, dev))
+				return true;
+		}
+	} else {
+		nhi = rcu_dereference(nh->nh_info);
+		if (nhc_l3mdev_matches_dev(&nhi->fib_nhc, dev))
+			return true;
+	}
+
+	return false;
+}
+
+static inline unsigned int fib_info_num_path(const struct fib_info *fi)
+{
+	if (unlikely(fi->nh))
+		return nexthop_num_path(fi->nh);
+
+	return fi->fib_nhs;
+}
+
+int fib_check_nexthop(struct nexthop *nh, u8 scope,
+		      struct netlink_ext_ack *extack);
+
+static inline struct fib_nh_common *fib_info_nhc(struct fib_info *fi, int nhsel)
+{
+	if (unlikely(fi->nh))
+		return nexthop_fib_nhc(fi->nh, nhsel);
+
+	return &fi->fib_nh[nhsel].nh_common;
+}
+
+/* only used when fib_nh is built into fib_info */
+static inline struct fib_nh *fib_info_nh(struct fib_info *fi, int nhsel)
+{
+	WARN_ON(fi->nh);
+
+	return &fi->fib_nh[nhsel];
+}
+
+/*
+ * IPv6 variants
+ */
+int fib6_check_nexthop(struct nexthop *nh, struct fib6_config *cfg,
+		       struct netlink_ext_ack *extack);
+
+/* Caller should either hold rcu_read_lock(), or RTNL. */
+static inline struct fib6_nh *nexthop_fib6_nh(struct nexthop *nh)
+{
+	struct nh_info *nhi;
+
+	if (nh->is_group) {
+		struct nh_group *nh_grp;
+
+		nh_grp = rcu_dereference_rtnl(nh->nh_grp);
+		nh = nexthop_mpath_select(nh_grp, 0);
+		if (!nh)
+			return NULL;
+	}
+
+	nhi = rcu_dereference_rtnl(nh->nh_info);
+	if (nhi->family == AF_INET6)
+		return &nhi->fib6_nh;
+
+	return NULL;
+}
+
+/* Variant of nexthop_fib6_nh().
+ * Caller should either hold rcu_read_lock_bh(), or RTNL.
+ */
+static inline struct fib6_nh *nexthop_fib6_nh_bh(struct nexthop *nh)
+{
+	struct nh_info *nhi;
+
+	if (nh->is_group) {
+		struct nh_group *nh_grp;
+
+		nh_grp = rcu_dereference_bh_rtnl(nh->nh_grp);
+		nh = nexthop_mpath_select(nh_grp, 0);
+		if (!nh)
+			return NULL;
+	}
+
+	nhi = rcu_dereference_bh_rtnl(nh->nh_info);
+	if (nhi->family == AF_INET6)
+		return &nhi->fib6_nh;
+
+	return NULL;
+}
+
+static inline struct net_device *fib6_info_nh_dev(struct fib6_info *f6i)
+{
+	struct fib6_nh *fib6_nh;
+
+	fib6_nh = f6i->nh ? nexthop_fib6_nh(f6i->nh) : f6i->fib6_nh;
+	return fib6_nh->fib_nh_dev;
+}
+
+static inline void nexthop_path_fib6_result(struct fib6_result *res, int hash)
+{
+	struct nexthop *nh = res->f6i->nh;
+	struct nh_info *nhi;
+
+	nh = nexthop_select_path(nh, hash);
+
+	nhi = rcu_dereference_rtnl(nh->nh_info);
+	if (nhi->reject_nh) {
+		res->fib6_type = RTN_BLACKHOLE;
+		res->fib6_flags |= RTF_REJECT;
+		res->nh = nexthop_fib6_nh(nh);
+	} else {
+		res->nh = &nhi->fib6_nh;
+	}
+}
+
+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