Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next

Pull networking updates from David Miller:
 "Some highlights from this development cycle:

   1) Big refactoring of ipv6 route and neigh handling to support
      nexthop objects configurable as units from userspace. From David
      Ahern.

   2) Convert explored_states in BPF verifier into a hash table,
      significantly decreased state held for programs with bpf2bpf
      calls, from Alexei Starovoitov.

   3) Implement bpf_send_signal() helper, from Yonghong Song.

   4) Various classifier enhancements to mvpp2 driver, from Maxime
      Chevallier.

   5) Add aRFS support to hns3 driver, from Jian Shen.

   6) Fix use after free in inet frags by allocating fqdirs dynamically
      and reworking how rhashtable dismantle occurs, from Eric Dumazet.

   7) Add act_ctinfo packet classifier action, from Kevin
      Darbyshire-Bryant.

   8) Add TFO key backup infrastructure, from Jason Baron.

   9) Remove several old and unused ISDN drivers, from Arnd Bergmann.

  10) Add devlink notifications for flash update status to mlxsw driver,
      from Jiri Pirko.

  11) Lots of kTLS offload infrastructure fixes, from Jakub Kicinski.

  12) Add support for mv88e6250 DSA chips, from Rasmus Villemoes.

  13) Various enhancements to ipv6 flow label handling, from Eric
      Dumazet and Willem de Bruijn.

  14) Support TLS offload in nfp driver, from Jakub Kicinski, Dirk van
      der Merwe, and others.

  15) Various improvements to axienet driver including converting it to
      phylink, from Robert Hancock.

  16) Add PTP support to sja1105 DSA driver, from Vladimir Oltean.

  17) Add mqprio qdisc offload support to dpaa2-eth, from Ioana
      Radulescu.

  18) Add devlink health reporting to mlx5, from Moshe Shemesh.

  19) Convert stmmac over to phylink, from Jose Abreu.

  20) Add PTP PHC (Physical Hardware Clock) support to mlxsw, from
      Shalom Toledo.

  21) Add nftables SYNPROXY support, from Fernando Fernandez Mancera.

  22) Convert tcp_fastopen over to use SipHash, from Ard Biesheuvel.

  23) Track spill/fill of constants in BPF verifier, from Alexei
      Starovoitov.

  24) Support bounded loops in BPF, from Alexei Starovoitov.

  25) Various page_pool API fixes and improvements, from Jesper Dangaard
      Brouer.

  26) Just like ipv4, support ref-countless ipv6 route handling. From
      Wei Wang.

  27) Support VLAN offloading in aquantia driver, from Igor Russkikh.

  28) Add AF_XDP zero-copy support to mlx5, from Maxim Mikityanskiy.

  29) Add flower GRE encap/decap support to nfp driver, from Pieter
      Jansen van Vuuren.

  30) Protect against stack overflow when using act_mirred, from John
      Hurley.

  31) Allow devmap map lookups from eBPF, from Toke Høiland-Jørgensen.

  32) Use page_pool API in netsec driver, Ilias Apalodimas.

  33) Add Google gve network driver, from Catherine Sullivan.

  34) More indirect call avoidance, from Paolo Abeni.

  35) Add kTLS TX HW offload support to mlx5, from Tariq Toukan.

  36) Add XDP_REDIRECT support to bnxt_en, from Andy Gospodarek.

  37) Add MPLS manipulation actions to TC, from John Hurley.

  38) Add sending a packet to connection tracking from TC actions, and
      then allow flower classifier matching on conntrack state. From
      Paul Blakey.

  39) Netfilter hw offload support, from Pablo Neira Ayuso"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (2080 commits)
  net/mlx5e: Return in default case statement in tx_post_resync_params
  mlx5: Return -EINVAL when WARN_ON_ONCE triggers in mlx5e_tls_resync().
  net: dsa: add support for BRIDGE_MROUTER attribute
  pkt_sched: Include const.h
  net: netsec: remove static declaration for netsec_set_tx_de()
  net: netsec: remove superfluous if statement
  netfilter: nf_tables: add hardware offload support
  net: flow_offload: rename tc_cls_flower_offload to flow_cls_offload
  net: flow_offload: add flow_block_cb_is_busy() and use it
  net: sched: remove tcf block API
  drivers: net: use flow block API
  net: sched: use flow block API
  net: flow_offload: add flow_block_cb_{priv, incref, decref}()
  net: flow_offload: add list handling functions
  net: flow_offload: add flow_block_cb_alloc() and flow_block_cb_free()
  net: flow_offload: rename TCF_BLOCK_BINDER_TYPE_* to FLOW_BLOCK_BINDER_TYPE_*
  net: flow_offload: rename TC_BLOCK_{UN}BIND to FLOW_BLOCK_{UN}BIND
  net: flow_offload: add flow_block_cb_setup_simple()
  net: hisilicon: Add an tx_desc to adapt HI13X1_GMAC
  net: hisilicon: Add an rx_desc to adapt HI13X1_GMAC
  ...

1 files changed, 1828 insertions, 0 deletions

diff --git a/net/ipv4/nexthop.c b/net/ipv4/nexthop.c
new file mode 100644
index 000000000000..5fe5a3981d43
--- /dev/null
+++ b/net/ipv4/nexthop.c
@@ -0,0 +1,1828 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Generic nexthop implementation
+ *
+ * Copyright (c) 2017-19 Cumulus Networks
+ * Copyright (c) 2017-19 David Ahern <dsa@cumulusnetworks.com>
+ */
+
+#include <linux/nexthop.h>
+#include <linux/rtnetlink.h>
+#include <linux/slab.h>
+#include <net/arp.h>
+#include <net/ipv6_stubs.h>
+#include <net/lwtunnel.h>
+#include <net/ndisc.h>
+#include <net/nexthop.h>
+#include <net/route.h>
+#include <net/sock.h>
+
+static void remove_nexthop(struct net *net, struct nexthop *nh,
+			   struct nl_info *nlinfo);
+
+#define NH_DEV_HASHBITS  8
+#define NH_DEV_HASHSIZE (1U << NH_DEV_HASHBITS)
+
+static const struct nla_policy rtm_nh_policy[NHA_MAX + 1] = {
+	[NHA_UNSPEC]		= { .strict_start_type = NHA_UNSPEC + 1 },
+	[NHA_ID]		= { .type = NLA_U32 },
+	[NHA_GROUP]		= { .type = NLA_BINARY },
+	[NHA_GROUP_TYPE]	= { .type = NLA_U16 },
+	[NHA_BLACKHOLE]		= { .type = NLA_FLAG },
+	[NHA_OIF]		= { .type = NLA_U32 },
+	[NHA_GATEWAY]		= { .type = NLA_BINARY },
+	[NHA_ENCAP_TYPE]	= { .type = NLA_U16 },
+	[NHA_ENCAP]		= { .type = NLA_NESTED },
+	[NHA_GROUPS]		= { .type = NLA_FLAG },
+	[NHA_MASTER]		= { .type = NLA_U32 },
+};
+
+static unsigned int nh_dev_hashfn(unsigned int val)
+{
+	unsigned int mask = NH_DEV_HASHSIZE - 1;
+
+	return (val ^
+		(val >> NH_DEV_HASHBITS) ^
+		(val >> (NH_DEV_HASHBITS * 2))) & mask;
+}
+
+static void nexthop_devhash_add(struct net *net, struct nh_info *nhi)
+{
+	struct net_device *dev = nhi->fib_nhc.nhc_dev;
+	struct hlist_head *head;
+	unsigned int hash;
+
+	WARN_ON(!dev);
+
+	hash = nh_dev_hashfn(dev->ifindex);
+	head = &net->nexthop.devhash[hash];
+	hlist_add_head(&nhi->dev_hash, head);
+}
+
+static void nexthop_free_mpath(struct nexthop *nh)
+{
+	struct nh_group *nhg;
+	int i;
+
+	nhg = rcu_dereference_raw(nh->nh_grp);
+	for (i = 0; i < nhg->num_nh; ++i)
+		WARN_ON(nhg->nh_entries[i].nh);
+
+	kfree(nhg);
+}
+
+static void nexthop_free_single(struct nexthop *nh)
+{
+	struct nh_info *nhi;
+
+	nhi = rcu_dereference_raw(nh->nh_info);
+	switch (nhi->family) {
+	case AF_INET:
+		fib_nh_release(nh->net, &nhi->fib_nh);
+		break;
+	case AF_INET6:
+		ipv6_stub->fib6_nh_release(&nhi->fib6_nh);
+		break;
+	}
+	kfree(nhi);
+}
+
+void nexthop_free_rcu(struct rcu_head *head)
+{
+	struct nexthop *nh = container_of(head, struct nexthop, rcu);
+
+	if (nh->is_group)
+		nexthop_free_mpath(nh);
+	else
+		nexthop_free_single(nh);
+
+	kfree(nh);
+}
+EXPORT_SYMBOL_GPL(nexthop_free_rcu);
+
+static struct nexthop *nexthop_alloc(void)
+{
+	struct nexthop *nh;
+
+	nh = kzalloc(sizeof(struct nexthop), GFP_KERNEL);
+	if (nh) {
+		INIT_LIST_HEAD(&nh->fi_list);
+		INIT_LIST_HEAD(&nh->f6i_list);
+		INIT_LIST_HEAD(&nh->grp_list);
+	}
+	return nh;
+}
+
+static struct nh_group *nexthop_grp_alloc(u16 num_nh)
+{
+	size_t sz = offsetof(struct nexthop, nh_grp)
+		    + sizeof(struct nh_group)
+		    + sizeof(struct nh_grp_entry) * num_nh;
+	struct nh_group *nhg;
+
+	nhg = kzalloc(sz, GFP_KERNEL);
+	if (nhg)
+		nhg->num_nh = num_nh;
+
+	return nhg;
+}
+
+static void nh_base_seq_inc(struct net *net)
+{
+	while (++net->nexthop.seq == 0)
+		;
+}
+
+/* no reference taken; rcu lock or rtnl must be held */
+struct nexthop *nexthop_find_by_id(struct net *net, u32 id)
+{
+	struct rb_node **pp, *parent = NULL, *next;
+
+	pp = &net->nexthop.rb_root.rb_node;
+	while (1) {
+		struct nexthop *nh;
+
+		next = rcu_dereference_raw(*pp);
+		if (!next)
+			break;
+		parent = next;
+
+		nh = rb_entry(parent, struct nexthop, rb_node);
+		if (id < nh->id)
+			pp = &next->rb_left;
+		else if (id > nh->id)
+			pp = &next->rb_right;
+		else
+			return nh;
+	}
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(nexthop_find_by_id);
+
+/* used for auto id allocation; called with rtnl held */
+static u32 nh_find_unused_id(struct net *net)
+{
+	u32 id_start = net->nexthop.last_id_allocated;
+
+	while (1) {
+		net->nexthop.last_id_allocated++;
+		if (net->nexthop.last_id_allocated == id_start)
+			break;
+
+		if (!nexthop_find_by_id(net, net->nexthop.last_id_allocated))
+			return net->nexthop.last_id_allocated;
+	}
+	return 0;
+}
+
+static int nla_put_nh_group(struct sk_buff *skb, struct nh_group *nhg)
+{
+	struct nexthop_grp *p;
+	size_t len = nhg->num_nh * sizeof(*p);
+	struct nlattr *nla;
+	u16 group_type = 0;
+	int i;
+
+	if (nhg->mpath)
+		group_type = NEXTHOP_GRP_TYPE_MPATH;
+
+	if (nla_put_u16(skb, NHA_GROUP_TYPE, group_type))
+		goto nla_put_failure;
+
+	nla = nla_reserve(skb, NHA_GROUP, len);
+	if (!nla)
+		goto nla_put_failure;
+
+	p = nla_data(nla);
+	for (i = 0; i < nhg->num_nh; ++i) {
+		p->id = nhg->nh_entries[i].nh->id;
+		p->weight = nhg->nh_entries[i].weight - 1;
+		p += 1;
+	}
+
+	return 0;
+
+nla_put_failure:
+	return -EMSGSIZE;
+}
+
+static int nh_fill_node(struct sk_buff *skb, struct nexthop *nh,
+			int event, u32 portid, u32 seq, unsigned int nlflags)
+{
+	struct fib6_nh *fib6_nh;
+	struct fib_nh *fib_nh;
+	struct nlmsghdr *nlh;
+	struct nh_info *nhi;
+	struct nhmsg *nhm;
+
+	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nhm), nlflags);
+	if (!nlh)
+		return -EMSGSIZE;
+
+	nhm = nlmsg_data(nlh);
+	nhm->nh_family = AF_UNSPEC;
+	nhm->nh_flags = nh->nh_flags;
+	nhm->nh_protocol = nh->protocol;
+	nhm->nh_scope = 0;
+	nhm->resvd = 0;
+
+	if (nla_put_u32(skb, NHA_ID, nh->id))
+		goto nla_put_failure;
+
+	if (nh->is_group) {
+		struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
+
+		if (nla_put_nh_group(skb, nhg))
+			goto nla_put_failure;
+		goto out;
+	}
+
+	nhi = rtnl_dereference(nh->nh_info);
+	nhm->nh_family = nhi->family;
+	if (nhi->reject_nh) {
+		if (nla_put_flag(skb, NHA_BLACKHOLE))
+			goto nla_put_failure;
+		goto out;
+	} else {
+		const struct net_device *dev;
+
+		dev = nhi->fib_nhc.nhc_dev;
+		if (dev && nla_put_u32(skb, NHA_OIF, dev->ifindex))
+			goto nla_put_failure;
+	}
+
+	nhm->nh_scope = nhi->fib_nhc.nhc_scope;
+	switch (nhi->family) {
+	case AF_INET:
+		fib_nh = &nhi->fib_nh;
+		if (fib_nh->fib_nh_gw_family &&
+		    nla_put_u32(skb, NHA_GATEWAY, fib_nh->fib_nh_gw4))
+			goto nla_put_failure;
+		break;
+
+	case AF_INET6:
+		fib6_nh = &nhi->fib6_nh;
+		if (fib6_nh->fib_nh_gw_family &&
+		    nla_put_in6_addr(skb, NHA_GATEWAY, &fib6_nh->fib_nh_gw6))
+			goto nla_put_failure;
+		break;
+	}
+
+	if (nhi->fib_nhc.nhc_lwtstate &&
+	    lwtunnel_fill_encap(skb, nhi->fib_nhc.nhc_lwtstate,
+				NHA_ENCAP, NHA_ENCAP_TYPE) < 0)
+		goto nla_put_failure;
+
+out:
+	nlmsg_end(skb, nlh);
+	return 0;
+
+nla_put_failure:
+	return -EMSGSIZE;
+}
+
+static size_t nh_nlmsg_size_grp(struct nexthop *nh)
+{
+	struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
+	size_t sz = sizeof(struct nexthop_grp) * nhg->num_nh;
+
+	return nla_total_size(sz) +
+	       nla_total_size(2);  /* NHA_GROUP_TYPE */
+}
+
+static size_t nh_nlmsg_size_single(struct nexthop *nh)
+{
+	struct nh_info *nhi = rtnl_dereference(nh->nh_info);
+	size_t sz;
+
+	/* covers NHA_BLACKHOLE since NHA_OIF and BLACKHOLE
+	 * are mutually exclusive
+	 */
+	sz = nla_total_size(4);  /* NHA_OIF */
+
+	switch (nhi->family) {
+	case AF_INET:
+		if (nhi->fib_nh.fib_nh_gw_family)
+			sz += nla_total_size(4);  /* NHA_GATEWAY */
+		break;
+
+	case AF_INET6:
+		/* NHA_GATEWAY */
+		if (nhi->fib6_nh.fib_nh_gw_family)
+			sz += nla_total_size(sizeof(const struct in6_addr));
+		break;
+	}
+
+	if (nhi->fib_nhc.nhc_lwtstate) {
+		sz += lwtunnel_get_encap_size(nhi->fib_nhc.nhc_lwtstate);
+		sz += nla_total_size(2);  /* NHA_ENCAP_TYPE */
+	}
+
+	return sz;
+}
+
+static size_t nh_nlmsg_size(struct nexthop *nh)
+{
+	size_t sz = nla_total_size(4);    /* NHA_ID */
+
+	if (nh->is_group)
+		sz += nh_nlmsg_size_grp(nh);
+	else
+		sz += nh_nlmsg_size_single(nh);
+
+	return sz;
+}
+
+static void nexthop_notify(int event, struct nexthop *nh, struct nl_info *info)
+{
+	unsigned int nlflags = info->nlh ? info->nlh->nlmsg_flags : 0;
+	u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
+	struct sk_buff *skb;
+	int err = -ENOBUFS;
+
+	skb = nlmsg_new(nh_nlmsg_size(nh), gfp_any());
+	if (!skb)
+		goto errout;
+
+	err = nh_fill_node(skb, nh, event, info->portid, seq, nlflags);
+	if (err < 0) {
+		/* -EMSGSIZE implies BUG in nh_nlmsg_size() */
+		WARN_ON(err == -EMSGSIZE);
+		kfree_skb(skb);
+		goto errout;
+	}
+
+	rtnl_notify(skb, info->nl_net, info->portid, RTNLGRP_NEXTHOP,
+		    info->nlh, gfp_any());
+	return;
+errout:
+	if (err < 0)
+		rtnl_set_sk_err(info->nl_net, RTNLGRP_NEXTHOP, err);
+}
+
+static bool valid_group_nh(struct nexthop *nh, unsigned int npaths,
+			   struct netlink_ext_ack *extack)
+{
+	if (nh->is_group) {
+		struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
+
+		/* nested multipath (group within a group) is not
+		 * supported
+		 */
+		if (nhg->mpath) {
+			NL_SET_ERR_MSG(extack,
+				       "Multipath group can not be a nexthop within a group");
+			return false;
+		}
+	} else {
+		struct nh_info *nhi = rtnl_dereference(nh->nh_info);
+
+		if (nhi->reject_nh && npaths > 1) {
+			NL_SET_ERR_MSG(extack,
+				       "Blackhole nexthop can not be used in a group with more than 1 path");
+			return false;
+		}
+	}
+
+	return true;
+}
+
+static int nh_check_attr_group(struct net *net, struct nlattr *tb[],
+			       struct netlink_ext_ack *extack)
+{
+	unsigned int len = nla_len(tb[NHA_GROUP]);
+	struct nexthop_grp *nhg;
+	unsigned int i, j;
+
+	if (len & (sizeof(struct nexthop_grp) - 1)) {
+		NL_SET_ERR_MSG(extack,
+			       "Invalid length for nexthop group attribute");
+		return -EINVAL;
+	}
+
+	/* convert len to number of nexthop ids */
+	len /= sizeof(*nhg);
+
+	nhg = nla_data(tb[NHA_GROUP]);
+	for (i = 0; i < len; ++i) {
+		if (nhg[i].resvd1 || nhg[i].resvd2) {
+			NL_SET_ERR_MSG(extack, "Reserved fields in nexthop_grp must be 0");
+			return -EINVAL;
+		}
+		if (nhg[i].weight > 254) {
+			NL_SET_ERR_MSG(extack, "Invalid value for weight");
+			return -EINVAL;
+		}
+		for (j = i + 1; j < len; ++j) {
+			if (nhg[i].id == nhg[j].id) {
+				NL_SET_ERR_MSG(extack, "Nexthop id can not be used twice in a group");
+				return -EINVAL;
+			}
+		}
+	}
+
+	nhg = nla_data(tb[NHA_GROUP]);
+	for (i = 0; i < len; ++i) {
+		struct nexthop *nh;
+
+		nh = nexthop_find_by_id(net, nhg[i].id);
+		if (!nh) {
+			NL_SET_ERR_MSG(extack, "Invalid nexthop id");
+			return -EINVAL;
+		}
+		if (!valid_group_nh(nh, len, extack))
+			return -EINVAL;
+	}
+	for (i = NHA_GROUP + 1; i < __NHA_MAX; ++i) {
+		if (!tb[i])
+			continue;
+
+		NL_SET_ERR_MSG(extack,
+			       "No other attributes can be set in nexthop groups");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static bool ipv6_good_nh(const struct fib6_nh *nh)
+{
+	int state = NUD_REACHABLE;
+	struct neighbour *n;
+
+	rcu_read_lock_bh();
+
+	n = __ipv6_neigh_lookup_noref_stub(nh->fib_nh_dev, &nh->fib_nh_gw6);
+	if (n)
+		state = n->nud_state;
+
+	rcu_read_unlock_bh();
+
+	return !!(state & NUD_VALID);
+}
+
+static bool ipv4_good_nh(const struct fib_nh *nh)
+{
+	int state = NUD_REACHABLE;
+	struct neighbour *n;
+
+	rcu_read_lock_bh();
+
+	n = __ipv4_neigh_lookup_noref(nh->fib_nh_dev,
+				      (__force u32)nh->fib_nh_gw4);
+	if (n)
+		state = n->nud_state;
+
+	rcu_read_unlock_bh();
+
+	return !!(state & NUD_VALID);
+}
+
+struct nexthop *nexthop_select_path(struct nexthop *nh, int hash)
+{
+	struct nexthop *rc = NULL;
+	struct nh_group *nhg;
+	int i;
+
+	if (!nh->is_group)
+		return nh;
+
+	nhg = rcu_dereference(nh->nh_grp);
+	for (i = 0; i < nhg->num_nh; ++i) {
+		struct nh_grp_entry *nhge = &nhg->nh_entries[i];
+		struct nh_info *nhi;
+
+		if (hash > atomic_read(&nhge->upper_bound))
+			continue;
+
+		/* nexthops always check if it is good and does
+		 * not rely on a sysctl for this behavior
+		 */
+		nhi = rcu_dereference(nhge->nh->nh_info);
+		switch (nhi->family) {
+		case AF_INET:
+			if (ipv4_good_nh(&nhi->fib_nh))
+				return nhge->nh;
+			break;
+		case AF_INET6:
+			if (ipv6_good_nh(&nhi->fib6_nh))
+				return nhge->nh;
+			break;
+		}
+
+		if (!rc)
+			rc = nhge->nh;
+	}
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(nexthop_select_path);
+
+int nexthop_for_each_fib6_nh(struct nexthop *nh,
+			     int (*cb)(struct fib6_nh *nh, void *arg),
+			     void *arg)
+{
+	struct nh_info *nhi;
+	int err;
+
+	if (nh->is_group) {
+		struct nh_group *nhg;
+		int i;
+
+		nhg = rcu_dereference_rtnl(nh->nh_grp);
+		for (i = 0; i < nhg->num_nh; i++) {
+			struct nh_grp_entry *nhge = &nhg->nh_entries[i];
+
+			nhi = rcu_dereference_rtnl(nhge->nh->nh_info);
+			err = cb(&nhi->fib6_nh, arg);
+			if (err)
+				return err;
+		}
+	} else {
+		nhi = rcu_dereference_rtnl(nh->nh_info);
+		err = cb(&nhi->fib6_nh, arg);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nexthop_for_each_fib6_nh);
+
+static int check_src_addr(const struct in6_addr *saddr,
+			  struct netlink_ext_ack *extack)
+{
+	if (!ipv6_addr_any(saddr)) {
+		NL_SET_ERR_MSG(extack, "IPv6 routes using source address can not use nexthop objects");
+		return -EINVAL;
+	}
+	return 0;
+}
+
+int fib6_check_nexthop(struct nexthop *nh, struct fib6_config *cfg,
+		       struct netlink_ext_ack *extack)
+{
+	struct nh_info *nhi;
+
+	/* fib6_src is unique to a fib6_info and limits the ability to cache
+	 * routes in fib6_nh within a nexthop that is potentially shared
+	 * across multiple fib entries. If the config wants to use source
+	 * routing it can not use nexthop objects. mlxsw also does not allow
+	 * fib6_src on routes.
+	 */
+	if (cfg && check_src_addr(&cfg->fc_src, extack) < 0)
+		return -EINVAL;
+
+	if (nh->is_group) {
+		struct nh_group *nhg;
+
+		nhg = rtnl_dereference(nh->nh_grp);
+		if (nhg->has_v4)
+			goto no_v4_nh;
+	} else {
+		nhi = rtnl_dereference(nh->nh_info);
+		if (nhi->family == AF_INET)
+			goto no_v4_nh;
+	}
+
+	return 0;
+no_v4_nh:
+	NL_SET_ERR_MSG(extack, "IPv6 routes can not use an IPv4 nexthop");
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(fib6_check_nexthop);
+
+/* if existing nexthop has ipv6 routes linked to it, need
+ * to verify this new spec works with ipv6
+ */
+static int fib6_check_nh_list(struct nexthop *old, struct nexthop *new,
+			      struct netlink_ext_ack *extack)
+{
+	struct fib6_info *f6i;
+
+	if (list_empty(&old->f6i_list))
+		return 0;
+
+	list_for_each_entry(f6i, &old->f6i_list, nh_list) {
+		if (check_src_addr(&f6i->fib6_src.addr, extack) < 0)
+			return -EINVAL;
+	}
+
+	return fib6_check_nexthop(new, NULL, extack);
+}
+
+static int nexthop_check_scope(struct nexthop *nh, u8 scope,
+			       struct netlink_ext_ack *extack)
+{
+	struct nh_info *nhi;
+
+	nhi = rtnl_dereference(nh->nh_info);
+	if (scope == RT_SCOPE_HOST && nhi->fib_nhc.nhc_gw_family) {
+		NL_SET_ERR_MSG(extack,
+			       "Route with host scope can not have a gateway");
+		return -EINVAL;
+	}
+
+	if (nhi->fib_nhc.nhc_flags & RTNH_F_ONLINK && scope >= RT_SCOPE_LINK) {
+		NL_SET_ERR_MSG(extack, "Scope mismatch with nexthop");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/* Invoked by fib add code to verify nexthop by id is ok with
+ * config for prefix; parts of fib_check_nh not done when nexthop
+ * object is used.
+ */
+int fib_check_nexthop(struct nexthop *nh, u8 scope,
+		      struct netlink_ext_ack *extack)
+{
+	int err = 0;
+
+	if (nh->is_group) {
+		struct nh_group *nhg;
+
+		if (scope == RT_SCOPE_HOST) {
+			NL_SET_ERR_MSG(extack, "Route with host scope can not have multiple nexthops");
+			err = -EINVAL;
+			goto out;
+		}
+
+		nhg = rtnl_dereference(nh->nh_grp);
+		/* all nexthops in a group have the same scope */
+		err = nexthop_check_scope(nhg->nh_entries[0].nh, scope, extack);
+	} else {
+		err = nexthop_check_scope(nh, scope, extack);
+	}
+out:
+	return err;
+}
+
+static int fib_check_nh_list(struct nexthop *old, struct nexthop *new,
+			     struct netlink_ext_ack *extack)
+{
+	struct fib_info *fi;
+
+	list_for_each_entry(fi, &old->fi_list, nh_list) {
+		int err;
+
+		err = fib_check_nexthop(new, fi->fib_scope, extack);
+		if (err)
+			return err;
+	}
+	return 0;
+}
+
+static void nh_group_rebalance(struct nh_group *nhg)
+{
+	int total = 0;
+	int w = 0;
+	int i;
+
+	for (i = 0; i < nhg->num_nh; ++i)
+		total += nhg->nh_entries[i].weight;
+
+	for (i = 0; i < nhg->num_nh; ++i) {
+		struct nh_grp_entry *nhge = &nhg->nh_entries[i];
+		int upper_bound;
+
+		w += nhge->weight;
+		upper_bound = DIV_ROUND_CLOSEST_ULL((u64)w << 31, total) - 1;
+		atomic_set(&nhge->upper_bound, upper_bound);
+	}
+}
+
+static void remove_nh_grp_entry(struct nh_grp_entry *nhge,
+				struct nh_group *nhg,
+				struct nl_info *nlinfo)
+{
+	struct nexthop *nh = nhge->nh;
+	struct nh_grp_entry *nhges;
+	bool found = false;
+	int i;
+
+	WARN_ON(!nh);
+
+	nhges = nhg->nh_entries;
+	for (i = 0; i < nhg->num_nh; ++i) {
+		if (found) {
+			nhges[i-1].nh = nhges[i].nh;
+			nhges[i-1].weight = nhges[i].weight;
+			list_del(&nhges[i].nh_list);
+			list_add(&nhges[i-1].nh_list, &nhges[i-1].nh->grp_list);
+		} else if (nhg->nh_entries[i].nh == nh) {
+			found = true;
+		}
+	}
+
+	if (WARN_ON(!found))
+		return;
+
+	nhg->num_nh--;
+	nhg->nh_entries[nhg->num_nh].nh = NULL;
+
+	nh_group_rebalance(nhg);
+
+	nexthop_put(nh);
+
+	if (nlinfo)
+		nexthop_notify(RTM_NEWNEXTHOP, nhge->nh_parent, nlinfo);
+}
+
+static void remove_nexthop_from_groups(struct net *net, struct nexthop *nh,
+				       struct nl_info *nlinfo)
+{
+	struct nh_grp_entry *nhge, *tmp;
+
+	list_for_each_entry_safe(nhge, tmp, &nh->grp_list, nh_list) {
+		struct nh_group *nhg;
+
+		list_del(&nhge->nh_list);
+		nhg = rtnl_dereference(nhge->nh_parent->nh_grp);
+		remove_nh_grp_entry(nhge, nhg, nlinfo);
+
+		/* if this group has no more entries then remove it */
+		if (!nhg->num_nh)
+			remove_nexthop(net, nhge->nh_parent, nlinfo);
+	}
+}
+
+static void remove_nexthop_group(struct nexthop *nh, struct nl_info *nlinfo)
+{
+	struct nh_group *nhg = rcu_dereference_rtnl(nh->nh_grp);
+	int i, num_nh = nhg->num_nh;
+
+	for (i = 0; i < num_nh; ++i) {
+		struct nh_grp_entry *nhge = &nhg->nh_entries[i];
+
+		if (WARN_ON(!nhge->nh))
+			continue;
+
+		list_del(&nhge->nh_list);
+		nexthop_put(nhge->nh);
+		nhge->nh = NULL;
+		nhg->num_nh--;
+	}
+}
+
+/* not called for nexthop replace */
+static void __remove_nexthop_fib(struct net *net, struct nexthop *nh)
+{
+	struct fib6_info *f6i, *tmp;
+	bool do_flush = false;
+	struct fib_info *fi;
+
+	list_for_each_entry(fi, &nh->fi_list, nh_list) {
+		fi->fib_flags |= RTNH_F_DEAD;
+		do_flush = true;
+	}
+	if (do_flush)
+		fib_flush(net);
+
+	/* ip6_del_rt removes the entry from this list hence the _safe */
+	list_for_each_entry_safe(f6i, tmp, &nh->f6i_list, nh_list) {
+		/* __ip6_del_rt does a release, so do a hold here */
+		fib6_info_hold(f6i);
+		ipv6_stub->ip6_del_rt(net, f6i);
+	}
+}
+
+static void __remove_nexthop(struct net *net, struct nexthop *nh,
+			     struct nl_info *nlinfo)
+{
+	__remove_nexthop_fib(net, nh);
+
+	if (nh->is_group) {
+		remove_nexthop_group(nh, nlinfo);
+	} else {
+		struct nh_info *nhi;
+
+		nhi = rtnl_dereference(nh->nh_info);
+		if (nhi->fib_nhc.nhc_dev)
+			hlist_del(&nhi->dev_hash);
+
+		remove_nexthop_from_groups(net, nh, nlinfo);
+	}
+}
+
+static void remove_nexthop(struct net *net, struct nexthop *nh,
+			   struct nl_info *nlinfo)
+{
+	/* remove from the tree */
+	rb_erase(&nh->rb_node, &net->nexthop.rb_root);
+
+	if (nlinfo)
+		nexthop_notify(RTM_DELNEXTHOP, nh, nlinfo);
+
+	__remove_nexthop(net, nh, nlinfo);
+	nh_base_seq_inc(net);
+
+	nexthop_put(nh);
+}
+
+/* if any FIB entries reference this nexthop, any dst entries
+ * need to be regenerated
+ */
+static void nh_rt_cache_flush(struct net *net, struct nexthop *nh)
+{
+	struct fib6_info *f6i;
+
+	if (!list_empty(&nh->fi_list))
+		rt_cache_flush(net);
+
+	list_for_each_entry(f6i, &nh->f6i_list, nh_list)
+		ipv6_stub->fib6_update_sernum(net, f6i);
+}
+
+static int replace_nexthop_grp(struct net *net, struct nexthop *old,
+			       struct nexthop *new,
+			       struct netlink_ext_ack *extack)
+{
+	struct nh_group *oldg, *newg;
+	int i;
+
+	if (!new->is_group) {
+		NL_SET_ERR_MSG(extack, "Can not replace a nexthop group with a nexthop.");
+		return -EINVAL;
+	}
+
+	oldg = rtnl_dereference(old->nh_grp);
+	newg = rtnl_dereference(new->nh_grp);
+
+	/* update parents - used by nexthop code for cleanup */
+	for (i = 0; i < newg->num_nh; i++)
+		newg->nh_entries[i].nh_parent = old;
+
+	rcu_assign_pointer(old->nh_grp, newg);
+
+	for (i = 0; i < oldg->num_nh; i++)
+		oldg->nh_entries[i].nh_parent = new;
+
+	rcu_assign_pointer(new->nh_grp, oldg);
+
+	return 0;
+}
+
+static int replace_nexthop_single(struct net *net, struct nexthop *old,
+				  struct nexthop *new,
+				  struct netlink_ext_ack *extack)
+{
+	struct nh_info *oldi, *newi;
+
+	if (new->is_group) {
+		NL_SET_ERR_MSG(extack, "Can not replace a nexthop with a nexthop group.");
+		return -EINVAL;
+	}
+
+	oldi = rtnl_dereference(old->nh_info);
+	newi = rtnl_dereference(new->nh_info);
+
+	newi->nh_parent = old;
+	oldi->nh_parent = new;
+
+	old->protocol = new->protocol;
+	old->nh_flags = new->nh_flags;
+
+	rcu_assign_pointer(old->nh_info, newi);
+	rcu_assign_pointer(new->nh_info, oldi);
+
+	return 0;
+}
+
+static void __nexthop_replace_notify(struct net *net, struct nexthop *nh,
+				     struct nl_info *info)
+{
+	struct fib6_info *f6i;
+
+	if (!list_empty(&nh->fi_list)) {
+		struct fib_info *fi;
+
+		/* expectation is a few fib_info per nexthop and then
+		 * a lot of routes per fib_info. So mark the fib_info
+		 * and then walk the fib tables once
+		 */
+		list_for_each_entry(fi, &nh->fi_list, nh_list)
+			fi->nh_updated = true;
+
+		fib_info_notify_update(net, info);
+
+		list_for_each_entry(fi, &nh->fi_list, nh_list)
+			fi->nh_updated = false;
+	}
+
+	list_for_each_entry(f6i, &nh->f6i_list, nh_list)
+		ipv6_stub->fib6_rt_update(net, f6i, info);
+}
+
+/* send RTM_NEWROUTE with REPLACE flag set for all FIB entries
+ * linked to this nexthop and for all groups that the nexthop
+ * is a member of
+ */
+static void nexthop_replace_notify(struct net *net, struct nexthop *nh,
+				   struct nl_info *info)
+{
+	struct nh_grp_entry *nhge;
+
+	__nexthop_replace_notify(net, nh, info);
+
+	list_for_each_entry(nhge, &nh->grp_list, nh_list)
+		__nexthop_replace_notify(net, nhge->nh_parent, info);
+}
+
+static int replace_nexthop(struct net *net, struct nexthop *old,
+			   struct nexthop *new, struct netlink_ext_ack *extack)
+{
+	bool new_is_reject = false;
+	struct nh_grp_entry *nhge;
+	int err;
+
+	/* check that existing FIB entries are ok with the
+	 * new nexthop definition
+	 */
+	err = fib_check_nh_list(old, new, extack);
+	if (err)
+		return err;
+
+	err = fib6_check_nh_list(old, new, extack);
+	if (err)
+		return err;
+
+	if (!new->is_group) {
+		struct nh_info *nhi = rtnl_dereference(new->nh_info);
+
+		new_is_reject = nhi->reject_nh;
+	}
+
+	list_for_each_entry(nhge, &old->grp_list, nh_list) {
+		/* if new nexthop is a blackhole, any groups using this
+		 * nexthop cannot have more than 1 path
+		 */
+		if (new_is_reject &&
+		    nexthop_num_path(nhge->nh_parent) > 1) {
+			NL_SET_ERR_MSG(extack, "Blackhole nexthop can not be a member of a group with more than one path");
+			return -EINVAL;
+		}
+
+		err = fib_check_nh_list(nhge->nh_parent, new, extack);
+		if (err)
+			return err;
+
+		err = fib6_check_nh_list(nhge->nh_parent, new, extack);
+		if (err)
+			return err;
+	}
+
+	if (old->is_group)
+		err = replace_nexthop_grp(net, old, new, extack);
+	else
+		err = replace_nexthop_single(net, old, new, extack);
+
+	if (!err) {
+		nh_rt_cache_flush(net, old);
+
+		__remove_nexthop(net, new, NULL);
+		nexthop_put(new);
+	}
+
+	return err;
+}
+
+/* called with rtnl_lock held */
+static int insert_nexthop(struct net *net, struct nexthop *new_nh,
+			  struct nh_config *cfg, struct netlink_ext_ack *extack)
+{
+	struct rb_node **pp, *parent = NULL, *next;
+	struct rb_root *root = &net->nexthop.rb_root;
+	bool replace = !!(cfg->nlflags & NLM_F_REPLACE);
+	bool create = !!(cfg->nlflags & NLM_F_CREATE);
+	u32 new_id = new_nh->id;
+	int replace_notify = 0;
+	int rc = -EEXIST;
+
+	pp = &root->rb_node;
+	while (1) {
+		struct nexthop *nh;
+
+		next = rtnl_dereference(*pp);
+		if (!next)
+			break;
+
+		parent = next;
+
+		nh = rb_entry(parent, struct nexthop, rb_node);
+		if (new_id < nh->id) {
+			pp = &next->rb_left;
+		} else if (new_id > nh->id) {
+			pp = &next->rb_right;
+		} else if (replace) {
+			rc = replace_nexthop(net, nh, new_nh, extack);
+			if (!rc) {
+				new_nh = nh; /* send notification with old nh */
+				replace_notify = 1;
+			}
+			goto out;
+		} else {
+			/* id already exists and not a replace */
+			goto out;
+		}
+	}
+
+	if (replace && !create) {
+		NL_SET_ERR_MSG(extack, "Replace specified without create and no entry exists");
+		rc = -ENOENT;
+		goto out;
+	}
+
+	rb_link_node_rcu(&new_nh->rb_node, parent, pp);
+	rb_insert_color(&new_nh->rb_node, root);
+	rc = 0;
+out:
+	if (!rc) {
+		nh_base_seq_inc(net);
+		nexthop_notify(RTM_NEWNEXTHOP, new_nh, &cfg->nlinfo);
+		if (replace_notify)
+			nexthop_replace_notify(net, new_nh, &cfg->nlinfo);
+	}
+
+	return rc;
+}
+
+/* rtnl */
+/* remove all nexthops tied to a device being deleted */
+static void nexthop_flush_dev(struct net_device *dev)
+{
+	unsigned int hash = nh_dev_hashfn(dev->ifindex);
+	struct net *net = dev_net(dev);
+	struct hlist_head *head = &net->nexthop.devhash[hash];
+	struct hlist_node *n;
+	struct nh_info *nhi;
+
+	hlist_for_each_entry_safe(nhi, n, head, dev_hash) {
+		if (nhi->fib_nhc.nhc_dev != dev)
+			continue;
+
+		remove_nexthop(net, nhi->nh_parent, NULL);
+	}
+}
+
+/* rtnl; called when net namespace is deleted */
+static void flush_all_nexthops(struct net *net)
+{
+	struct rb_root *root = &net->nexthop.rb_root;
+	struct rb_node *node;
+	struct nexthop *nh;
+
+	while ((node = rb_first(root))) {
+		nh = rb_entry(node, struct nexthop, rb_node);
+		remove_nexthop(net, nh, NULL);
+		cond_resched();
+	}
+}
+
+static struct nexthop *nexthop_create_group(struct net *net,
+					    struct nh_config *cfg)
+{
+	struct nlattr *grps_attr = cfg->nh_grp;
+	struct nexthop_grp *entry = nla_data(grps_attr);
+	struct nh_group *nhg;
+	struct nexthop *nh;
+	int i;
+
+	nh = nexthop_alloc();
+	if (!nh)
+		return ERR_PTR(-ENOMEM);
+
+	nh->is_group = 1;
+
+	nhg = nexthop_grp_alloc(nla_len(grps_attr) / sizeof(*entry));
+	if (!nhg) {
+		kfree(nh);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	for (i = 0; i < nhg->num_nh; ++i) {
+		struct nexthop *nhe;
+		struct nh_info *nhi;
+
+		nhe = nexthop_find_by_id(net, entry[i].id);
+		if (!nexthop_get(nhe))
+			goto out_no_nh;
+
+		nhi = rtnl_dereference(nhe->nh_info);
+		if (nhi->family == AF_INET)
+			nhg->has_v4 = true;
+
+		nhg->nh_entries[i].nh = nhe;
+		nhg->nh_entries[i].weight = entry[i].weight + 1;
+		list_add(&nhg->nh_entries[i].nh_list, &nhe->grp_list);
+		nhg->nh_entries[i].nh_parent = nh;
+	}
+
+	if (cfg->nh_grp_type == NEXTHOP_GRP_TYPE_MPATH) {
+		nhg->mpath = 1;
+		nh_group_rebalance(nhg);
+	}
+
+	rcu_assign_pointer(nh->nh_grp, nhg);
+
+	return nh;
+
+out_no_nh:
+	for (; i >= 0; --i)
+		nexthop_put(nhg->nh_entries[i].nh);
+
+	kfree(nhg);
+	kfree(nh);
+
+	return ERR_PTR(-ENOENT);
+}
+
+static int nh_create_ipv4(struct net *net, struct nexthop *nh,
+			  struct nh_info *nhi, struct nh_config *cfg,
+			  struct netlink_ext_ack *extack)
+{
+	struct fib_nh *fib_nh = &nhi->fib_nh;
+	struct fib_config fib_cfg = {
+		.fc_oif   = cfg->nh_ifindex,
+		.fc_gw4   = cfg->gw.ipv4,
+		.fc_gw_family = cfg->gw.ipv4 ? AF_INET : 0,
+		.fc_flags = cfg->nh_flags,
+		.fc_encap = cfg->nh_encap,
+		.fc_encap_type = cfg->nh_encap_type,
+	};
+	u32 tb_id = l3mdev_fib_table(cfg->dev);
+	int err = -EINVAL;
+
+	err = fib_nh_init(net, fib_nh, &fib_cfg, 1, extack);
+	if (err) {
+		fib_nh_release(net, fib_nh);
+		goto out;
+	}
+
+	/* sets nh_dev if successful */
+	err = fib_check_nh(net, fib_nh, tb_id, 0, extack);
+	if (!err) {
+		nh->nh_flags = fib_nh->fib_nh_flags;
+		fib_info_update_nhc_saddr(net, &fib_nh->nh_common,
+					  fib_nh->fib_nh_scope);
+	} else {
+		fib_nh_release(net, fib_nh);
+	}
+out:
+	return err;
+}
+
+static int nh_create_ipv6(struct net *net,  struct nexthop *nh,
+			  struct nh_info *nhi, struct nh_config *cfg,
+			  struct netlink_ext_ack *extack)
+{
+	struct fib6_nh *fib6_nh = &nhi->fib6_nh;
+	struct fib6_config fib6_cfg = {
+		.fc_table = l3mdev_fib_table(cfg->dev),
+		.fc_ifindex = cfg->nh_ifindex,
+		.fc_gateway = cfg->gw.ipv6,
+		.fc_flags = cfg->nh_flags,
+		.fc_encap = cfg->nh_encap,
+		.fc_encap_type = cfg->nh_encap_type,
+	};
+	int err;
+
+	if (!ipv6_addr_any(&cfg->gw.ipv6))
+		fib6_cfg.fc_flags |= RTF_GATEWAY;
+
+	/* sets nh_dev if successful */
+	err = ipv6_stub->fib6_nh_init(net, fib6_nh, &fib6_cfg, GFP_KERNEL,
+				      extack);
+	if (err)
+		ipv6_stub->fib6_nh_release(fib6_nh);
+	else
+		nh->nh_flags = fib6_nh->fib_nh_flags;
+
+	return err;
+}
+
+static struct nexthop *nexthop_create(struct net *net, struct nh_config *cfg,
+				      struct netlink_ext_ack *extack)
+{
+	struct nh_info *nhi;
+	struct nexthop *nh;
+	int err = 0;
+
+	nh = nexthop_alloc();
+	if (!nh)
+		return ERR_PTR(-ENOMEM);
+
+	nhi = kzalloc(sizeof(*nhi), GFP_KERNEL);
+	if (!nhi) {
+		kfree(nh);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	nh->nh_flags = cfg->nh_flags;
+	nh->net = net;
+
+	nhi->nh_parent = nh;
+	nhi->family = cfg->nh_family;
+	nhi->fib_nhc.nhc_scope = RT_SCOPE_LINK;
+
+	if (cfg->nh_blackhole) {
+		nhi->reject_nh = 1;
+		cfg->nh_ifindex = net->loopback_dev->ifindex;
+	}
+
+	switch (cfg->nh_family) {
+	case AF_INET:
+		err = nh_create_ipv4(net, nh, nhi, cfg, extack);
+		break;
+	case AF_INET6:
+		err = nh_create_ipv6(net, nh, nhi, cfg, extack);
+		break;
+	}
+
+	if (err) {
+		kfree(nhi);
+		kfree(nh);
+		return ERR_PTR(err);
+	}
+
+	/* add the entry to the device based hash */
+	nexthop_devhash_add(net, nhi);
+
+	rcu_assign_pointer(nh->nh_info, nhi);
+
+	return nh;
+}
+
+/* called with rtnl lock held */
+static struct nexthop *nexthop_add(struct net *net, struct nh_config *cfg,
+				   struct netlink_ext_ack *extack)
+{
+	struct nexthop *nh;
+	int err;
+
+	if (cfg->nlflags & NLM_F_REPLACE && !cfg->nh_id) {
+		NL_SET_ERR_MSG(extack, "Replace requires nexthop id");
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (!cfg->nh_id) {
+		cfg->nh_id = nh_find_unused_id(net);
+		if (!cfg->nh_id) {
+			NL_SET_ERR_MSG(extack, "No unused id");
+			return ERR_PTR(-EINVAL);
+		}
+	}
+
+	if (cfg->nh_grp)
+		nh = nexthop_create_group(net, cfg);
+	else
+		nh = nexthop_create(net, cfg, extack);
+
+	if (IS_ERR(nh))
+		return nh;
+
+	refcount_set(&nh->refcnt, 1);
+	nh->id = cfg->nh_id;
+	nh->protocol = cfg->nh_protocol;
+	nh->net = net;
+
+	err = insert_nexthop(net, nh, cfg, extack);
+	if (err) {
+		__remove_nexthop(net, nh, NULL);
+		nexthop_put(nh);
+		nh = ERR_PTR(err);
+	}
+
+	return nh;
+}
+
+static int rtm_to_nh_config(struct net *net, struct sk_buff *skb,
+			    struct nlmsghdr *nlh, struct nh_config *cfg,
+			    struct netlink_ext_ack *extack)
+{
+	struct nhmsg *nhm = nlmsg_data(nlh);
+	struct nlattr *tb[NHA_MAX + 1];
+	int err;
+
+	err = nlmsg_parse(nlh, sizeof(*nhm), tb, NHA_MAX, rtm_nh_policy,
+			  extack);
+	if (err < 0)
+		return err;
+
+	err = -EINVAL;
+	if (nhm->resvd || nhm->nh_scope) {
+		NL_SET_ERR_MSG(extack, "Invalid values in ancillary header");
+		goto out;
+	}
+	if (nhm->nh_flags & ~NEXTHOP_VALID_USER_FLAGS) {
+		NL_SET_ERR_MSG(extack, "Invalid nexthop flags in ancillary header");
+		goto out;
+	}
+
+	switch (nhm->nh_family) {
+	case AF_INET:
+	case AF_INET6:
+		break;
+	case AF_UNSPEC:
+		if (tb[NHA_GROUP])
+			break;
+		/* fallthrough */
+	default:
+		NL_SET_ERR_MSG(extack, "Invalid address family");
+		goto out;
+	}
+
+	if (tb[NHA_GROUPS] || tb[NHA_MASTER]) {
+		NL_SET_ERR_MSG(extack, "Invalid attributes in request");
+		goto out;
+	}
+
+	memset(cfg, 0, sizeof(*cfg));
+	cfg->nlflags = nlh->nlmsg_flags;
+	cfg->nlinfo.portid = NETLINK_CB(skb).portid;
+	cfg->nlinfo.nlh = nlh;
+	cfg->nlinfo.nl_net = net;
+
+	cfg->nh_family = nhm->nh_family;
+	cfg->nh_protocol = nhm->nh_protocol;
+	cfg->nh_flags = nhm->nh_flags;
+
+	if (tb[NHA_ID])
+		cfg->nh_id = nla_get_u32(tb[NHA_ID]);
+
+	if (tb[NHA_GROUP]) {
+		if (nhm->nh_family != AF_UNSPEC) {
+			NL_SET_ERR_MSG(extack, "Invalid family for group");
+			goto out;
+		}
+		cfg->nh_grp = tb[NHA_GROUP];
+
+		cfg->nh_grp_type = NEXTHOP_GRP_TYPE_MPATH;
+		if (tb[NHA_GROUP_TYPE])
+			cfg->nh_grp_type = nla_get_u16(tb[NHA_GROUP_TYPE]);
+
+		if (cfg->nh_grp_type > NEXTHOP_GRP_TYPE_MAX) {
+			NL_SET_ERR_MSG(extack, "Invalid group type");
+			goto out;
+		}
+		err = nh_check_attr_group(net, tb, extack);
+
+		/* no other attributes should be set */
+		goto out;
+	}
+
+	if (tb[NHA_BLACKHOLE]) {
+		if (tb[NHA_GATEWAY] || tb[NHA_OIF] ||
+		    tb[NHA_ENCAP]   || tb[NHA_ENCAP_TYPE]) {
+			NL_SET_ERR_MSG(extack, "Blackhole attribute can not be used with gateway or oif");
+			goto out;
+		}
+
+		cfg->nh_blackhole = 1;
+		err = 0;
+		goto out;
+	}
+
+	if (!tb[NHA_OIF]) {
+		NL_SET_ERR_MSG(extack, "Device attribute required for non-blackhole nexthops");
+		goto out;
+	}
+
+	cfg->nh_ifindex = nla_get_u32(tb[NHA_OIF]);
+	if (cfg->nh_ifindex)
+		cfg->dev = __dev_get_by_index(net, cfg->nh_ifindex);
+
+	if (!cfg->dev) {
+		NL_SET_ERR_MSG(extack, "Invalid device index");
+		goto out;
+	} else if (!(cfg->dev->flags & IFF_UP)) {
+		NL_SET_ERR_MSG(extack, "Nexthop device is not up");
+		err = -ENETDOWN;
+		goto out;
+	} else if (!netif_carrier_ok(cfg->dev)) {
+		NL_SET_ERR_MSG(extack, "Carrier for nexthop device is down");
+		err = -ENETDOWN;
+		goto out;
+	}
+
+	err = -EINVAL;
+	if (tb[NHA_GATEWAY]) {
+		struct nlattr *gwa = tb[NHA_GATEWAY];
+
+		switch (cfg->nh_family) {
+		case AF_INET:
+			if (nla_len(gwa) != sizeof(u32)) {
+				NL_SET_ERR_MSG(extack, "Invalid gateway");
+				goto out;
+			}
+			cfg->gw.ipv4 = nla_get_be32(gwa);
+			break;
+		case AF_INET6:
+			if (nla_len(gwa) != sizeof(struct in6_addr)) {
+				NL_SET_ERR_MSG(extack, "Invalid gateway");
+				goto out;
+			}
+			cfg->gw.ipv6 = nla_get_in6_addr(gwa);
+			break;
+		default:
+			NL_SET_ERR_MSG(extack,
+				       "Unknown address family for gateway");
+			goto out;
+		}
+	} else {
+		/* device only nexthop (no gateway) */
+		if (cfg->nh_flags & RTNH_F_ONLINK) {
+			NL_SET_ERR_MSG(extack,
+				       "ONLINK flag can not be set for nexthop without a gateway");
+			goto out;
+		}
+	}
+
+	if (tb[NHA_ENCAP]) {
+		cfg->nh_encap = tb[NHA_ENCAP];
+
+		if (!tb[NHA_ENCAP_TYPE]) {
+			NL_SET_ERR_MSG(extack, "LWT encapsulation type is missing");
+			goto out;
+		}
+
+		cfg->nh_encap_type = nla_get_u16(tb[NHA_ENCAP_TYPE]);
+		err = lwtunnel_valid_encap_type(cfg->nh_encap_type, extack);
+		if (err < 0)
+			goto out;
+
+	} else if (tb[NHA_ENCAP_TYPE]) {
+		NL_SET_ERR_MSG(extack, "LWT encapsulation attribute is missing");
+		goto out;
+	}
+
+
+	err = 0;
+out:
+	return err;
+}
+
+/* rtnl */
+static int rtm_new_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh,
+			   struct netlink_ext_ack *extack)
+{
+	struct net *net = sock_net(skb->sk);
+	struct nh_config cfg;
+	struct nexthop *nh;
+	int err;
+
+	err = rtm_to_nh_config(net, skb, nlh, &cfg, extack);
+	if (!err) {
+		nh = nexthop_add(net, &cfg, extack);
+		if (IS_ERR(nh))
+			err = PTR_ERR(nh);
+	}
+
+	return err;
+}
+
+static int nh_valid_get_del_req(struct nlmsghdr *nlh, u32 *id,
+				struct netlink_ext_ack *extack)
+{
+	struct nhmsg *nhm = nlmsg_data(nlh);
+	struct nlattr *tb[NHA_MAX + 1];
+	int err, i;
+
+	err = nlmsg_parse(nlh, sizeof(*nhm), tb, NHA_MAX, rtm_nh_policy,
+			  extack);
+	if (err < 0)
+		return err;
+
+	err = -EINVAL;
+	for (i = 0; i < __NHA_MAX; ++i) {
+		if (!tb[i])
+			continue;
+
+		switch (i) {
+		case NHA_ID:
+			break;
+		default:
+			NL_SET_ERR_MSG_ATTR(extack, tb[i],
+					    "Unexpected attribute in request");
+			goto out;
+		}
+	}
+	if (nhm->nh_protocol || nhm->resvd || nhm->nh_scope || nhm->nh_flags) {
+		NL_SET_ERR_MSG(extack, "Invalid values in header");
+		goto out;
+	}
+
+	if (!tb[NHA_ID]) {
+		NL_SET_ERR_MSG(extack, "Nexthop id is missing");
+		goto out;
+	}
+
+	*id = nla_get_u32(tb[NHA_ID]);
+	if (!(*id))
+		NL_SET_ERR_MSG(extack, "Invalid nexthop id");
+	else
+		err = 0;
+out:
+	return err;
+}
+
+/* rtnl */
+static int rtm_del_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh,
+			   struct netlink_ext_ack *extack)
+{
+	struct net *net = sock_net(skb->sk);
+	struct nl_info nlinfo = {
+		.nlh = nlh,
+		.nl_net = net,
+		.portid = NETLINK_CB(skb).portid,
+	};
+	struct nexthop *nh;
+	int err;
+	u32 id;
+
+	err = nh_valid_get_del_req(nlh, &id, extack);
+	if (err)
+		return err;
+
+	nh = nexthop_find_by_id(net, id);
+	if (!nh)
+		return -ENOENT;
+
+	remove_nexthop(net, nh, &nlinfo);
+
+	return 0;
+}
+
+/* rtnl */
+static int rtm_get_nexthop(struct sk_buff *in_skb, struct nlmsghdr *nlh,
+			   struct netlink_ext_ack *extack)
+{
+	struct net *net = sock_net(in_skb->sk);
+	struct sk_buff *skb = NULL;
+	struct nexthop *nh;
+	int err;
+	u32 id;
+
+	err = nh_valid_get_del_req(nlh, &id, extack);
+	if (err)
+		return err;
+
+	err = -ENOBUFS;
+	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
+	if (!skb)
+		goto out;
+
+	err = -ENOENT;
+	nh = nexthop_find_by_id(net, id);
+	if (!nh)
+		goto errout_free;
+
+	err = nh_fill_node(skb, nh, RTM_NEWNEXTHOP, NETLINK_CB(in_skb).portid,
+			   nlh->nlmsg_seq, 0);
+	if (err < 0) {
+		WARN_ON(err == -EMSGSIZE);
+		goto errout_free;
+	}
+
+	err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
+out:
+	return err;
+errout_free:
+	kfree_skb(skb);
+	goto out;
+}
+
+static bool nh_dump_filtered(struct nexthop *nh, int dev_idx, int master_idx,
+			     bool group_filter, u8 family)
+{
+	const struct net_device *dev;
+	const struct nh_info *nhi;
+
+	if (group_filter && !nh->is_group)
+		return true;
+
+	if (!dev_idx && !master_idx && !family)
+		return false;
+
+	if (nh->is_group)
+		return true;
+
+	nhi = rtnl_dereference(nh->nh_info);
+	if (family && nhi->family != family)
+		return true;
+
+	dev = nhi->fib_nhc.nhc_dev;
+	if (dev_idx && (!dev || dev->ifindex != dev_idx))
+		return true;
+
+	if (master_idx) {
+		struct net_device *master;
+
+		if (!dev)
+			return true;
+
+		master = netdev_master_upper_dev_get((struct net_device *)dev);
+		if (!master || master->ifindex != master_idx)
+			return true;
+	}
+
+	return false;
+}
+
+static int nh_valid_dump_req(const struct nlmsghdr *nlh, int *dev_idx,
+			     int *master_idx, bool *group_filter,
+			     struct netlink_callback *cb)
+{
+	struct netlink_ext_ack *extack = cb->extack;
+	struct nlattr *tb[NHA_MAX + 1];
+	struct nhmsg *nhm;
+	int err, i;
+	u32 idx;
+
+	err = nlmsg_parse(nlh, sizeof(*nhm), tb, NHA_MAX, rtm_nh_policy,
+			  NULL);
+	if (err < 0)
+		return err;
+
+	for (i = 0; i <= NHA_MAX; ++i) {
+		if (!tb[i])
+			continue;
+
+		switch (i) {
+		case NHA_OIF:
+			idx = nla_get_u32(tb[i]);
+			if (idx > INT_MAX) {
+				NL_SET_ERR_MSG(extack, "Invalid device index");
+				return -EINVAL;
+			}
+			*dev_idx = idx;
+			break;
+		case NHA_MASTER:
+			idx = nla_get_u32(tb[i]);
+			if (idx > INT_MAX) {
+				NL_SET_ERR_MSG(extack, "Invalid master device index");
+				return -EINVAL;
+			}
+			*master_idx = idx;
+			break;
+		case NHA_GROUPS:
+			*group_filter = true;
+			break;
+		default:
+			NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request");
+			return -EINVAL;
+		}
+	}
+
+	nhm = nlmsg_data(nlh);
+	if (nhm->nh_protocol || nhm->resvd || nhm->nh_scope || nhm->nh_flags) {
+		NL_SET_ERR_MSG(extack, "Invalid values in header for nexthop dump request");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/* rtnl */
+static int rtm_dump_nexthop(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	struct nhmsg *nhm = nlmsg_data(cb->nlh);
+	int dev_filter_idx = 0, master_idx = 0;
+	struct net *net = sock_net(skb->sk);
+	struct rb_root *root = &net->nexthop.rb_root;
+	bool group_filter = false;
+	struct rb_node *node;
+	int idx = 0, s_idx;
+	int err;
+
+	err = nh_valid_dump_req(cb->nlh, &dev_filter_idx, &master_idx,
+				&group_filter, cb);
+	if (err < 0)
+		return err;
+
+	s_idx = cb->args[0];
+	for (node = rb_first(root); node; node = rb_next(node)) {
+		struct nexthop *nh;
+
+		if (idx < s_idx)
+			goto cont;
+
+		nh = rb_entry(node, struct nexthop, rb_node);
+		if (nh_dump_filtered(nh, dev_filter_idx, master_idx,
+				     group_filter, nhm->nh_family))
+			goto cont;
+
+		err = nh_fill_node(skb, nh, RTM_NEWNEXTHOP,
+				   NETLINK_CB(cb->skb).portid,
+				   cb->nlh->nlmsg_seq, NLM_F_MULTI);
+		if (err < 0) {
+			if (likely(skb->len))
+				goto out;
+
+			goto out_err;
+		}
+cont:
+		idx++;
+	}
+
+out:
+	err = skb->len;
+out_err:
+	cb->args[0] = idx;
+	cb->seq = net->nexthop.seq;
+	nl_dump_check_consistent(cb, nlmsg_hdr(skb));
+
+	return err;
+}
+
+static void nexthop_sync_mtu(struct net_device *dev, u32 orig_mtu)
+{
+	unsigned int hash = nh_dev_hashfn(dev->ifindex);
+	struct net *net = dev_net(dev);
+	struct hlist_head *head = &net->nexthop.devhash[hash];
+	struct hlist_node *n;
+	struct nh_info *nhi;
+
+	hlist_for_each_entry_safe(nhi, n, head, dev_hash) {
+		if (nhi->fib_nhc.nhc_dev == dev) {
+			if (nhi->family == AF_INET)
+				fib_nhc_update_mtu(&nhi->fib_nhc, dev->mtu,
+						   orig_mtu);
+		}
+	}
+}
+
+/* rtnl */
+static int nh_netdev_event(struct notifier_block *this,
+			   unsigned long event, void *ptr)
+{
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+	struct netdev_notifier_info_ext *info_ext;
+
+	switch (event) {
+	case NETDEV_DOWN:
+	case NETDEV_UNREGISTER:
+		nexthop_flush_dev(dev);
+		break;
+	case NETDEV_CHANGE:
+		if (!(dev_get_flags(dev) & (IFF_RUNNING | IFF_LOWER_UP)))
+			nexthop_flush_dev(dev);
+		break;
+	case NETDEV_CHANGEMTU:
+		info_ext = ptr;
+		nexthop_sync_mtu(dev, info_ext->ext.mtu);
+		rt_cache_flush(dev_net(dev));
+		break;
+	}
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block nh_netdev_notifier = {
+	.notifier_call = nh_netdev_event,
+};
+
+static void __net_exit nexthop_net_exit(struct net *net)
+{
+	rtnl_lock();
+	flush_all_nexthops(net);
+	rtnl_unlock();
+	kfree(net->nexthop.devhash);
+}
+
+static int __net_init nexthop_net_init(struct net *net)
+{
+	size_t sz = sizeof(struct hlist_head) * NH_DEV_HASHSIZE;
+
+	net->nexthop.rb_root = RB_ROOT;
+	net->nexthop.devhash = kzalloc(sz, GFP_KERNEL);
+	if (!net->nexthop.devhash)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static struct pernet_operations nexthop_net_ops = {
+	.init = nexthop_net_init,
+	.exit = nexthop_net_exit,
+};
+
+static int __init nexthop_init(void)
+{
+	register_pernet_subsys(&nexthop_net_ops);
+
+	register_netdevice_notifier(&nh_netdev_notifier);
+
+	rtnl_register(PF_UNSPEC, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
+	rtnl_register(PF_UNSPEC, RTM_DELNEXTHOP, rtm_del_nexthop, NULL, 0);
+	rtnl_register(PF_UNSPEC, RTM_GETNEXTHOP, rtm_get_nexthop,
+		      rtm_dump_nexthop, 0);
+
+	rtnl_register(PF_INET, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
+	rtnl_register(PF_INET, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0);
+
+	rtnl_register(PF_INET6, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
+	rtnl_register(PF_INET6, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0);
+
+	return 0;
+}
+subsys_initcall(nexthop_init);