1 files changed, 331 insertions, 151 deletions

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 778d7f03404a..204297dffd2a 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -62,7 +62,9 @@
 struct rtnl_link {
 	rtnl_doit_func		doit;
 	rtnl_dumpit_func	dumpit;
+	struct module		*owner;
 	unsigned int		flags;
+	struct rcu_head		rcu;
 };
 
 static DEFINE_MUTEX(rtnl_mutex);
@@ -127,8 +129,7 @@ bool lockdep_rtnl_is_held(void)
 EXPORT_SYMBOL(lockdep_rtnl_is_held);
 #endif /* #ifdef CONFIG_PROVE_LOCKING */
 
-static struct rtnl_link __rcu *rtnl_msg_handlers[RTNL_FAMILY_MAX + 1];
-static refcount_t rtnl_msg_handlers_ref[RTNL_FAMILY_MAX + 1];
+static struct rtnl_link *__rcu *rtnl_msg_handlers[RTNL_FAMILY_MAX + 1];
 
 static inline int rtm_msgindex(int msgtype)
 {
@@ -144,72 +145,127 @@ static inline int rtm_msgindex(int msgtype)
 	return msgindex;
 }
 
-/**
- * __rtnl_register - Register a rtnetlink message type
- * @protocol: Protocol family or PF_UNSPEC
- * @msgtype: rtnetlink message type
- * @doit: Function pointer called for each request message
- * @dumpit: Function pointer called for each dump request (NLM_F_DUMP) message
- * @flags: rtnl_link_flags to modifiy behaviour of doit/dumpit functions
- *
- * Registers the specified function pointers (at least one of them has
- * to be non-NULL) to be called whenever a request message for the
- * specified protocol family and message type is received.
- *
- * The special protocol family PF_UNSPEC may be used to define fallback
- * function pointers for the case when no entry for the specific protocol
- * family exists.
- *
- * Returns 0 on success or a negative error code.
- */
-int __rtnl_register(int protocol, int msgtype,
-		    rtnl_doit_func doit, rtnl_dumpit_func dumpit,
-		    unsigned int flags)
+static struct rtnl_link *rtnl_get_link(int protocol, int msgtype)
+{
+	struct rtnl_link **tab;
+
+	if (protocol >= ARRAY_SIZE(rtnl_msg_handlers))
+		protocol = PF_UNSPEC;
+
+	tab = rcu_dereference_rtnl(rtnl_msg_handlers[protocol]);
+	if (!tab)
+		tab = rcu_dereference_rtnl(rtnl_msg_handlers[PF_UNSPEC]);
+
+	return tab[msgtype];
+}
+
+static int rtnl_register_internal(struct module *owner,
+				  int protocol, int msgtype,
+				  rtnl_doit_func doit, rtnl_dumpit_func dumpit,
+				  unsigned int flags)
 {
-	struct rtnl_link *tab;
+	struct rtnl_link *link, *old;
+	struct rtnl_link __rcu **tab;
 	int msgindex;
+	int ret = -ENOBUFS;
 
 	BUG_ON(protocol < 0 || protocol > RTNL_FAMILY_MAX);
 	msgindex = rtm_msgindex(msgtype);
 
-	tab = rcu_dereference_raw(rtnl_msg_handlers[protocol]);
+	rtnl_lock();
+	tab = rtnl_msg_handlers[protocol];
 	if (tab == NULL) {
-		tab = kcalloc(RTM_NR_MSGTYPES, sizeof(*tab), GFP_KERNEL);
-		if (tab == NULL)
-			return -ENOBUFS;
+		tab = kcalloc(RTM_NR_MSGTYPES, sizeof(void *), GFP_KERNEL);
+		if (!tab)
+			goto unlock;
 
+		/* ensures we see the 0 stores */
 		rcu_assign_pointer(rtnl_msg_handlers[protocol], tab);
 	}
 
+	old = rtnl_dereference(tab[msgindex]);
+	if (old) {
+		link = kmemdup(old, sizeof(*old), GFP_KERNEL);
+		if (!link)
+			goto unlock;
+	} else {
+		link = kzalloc(sizeof(*link), GFP_KERNEL);
+		if (!link)
+			goto unlock;
+	}
+
+	WARN_ON(link->owner && link->owner != owner);
+	link->owner = owner;
+
+	WARN_ON(doit && link->doit && link->doit != doit);
 	if (doit)
-		tab[msgindex].doit = doit;
+		link->doit = doit;
+	WARN_ON(dumpit && link->dumpit && link->dumpit != dumpit);
 	if (dumpit)
-		tab[msgindex].dumpit = dumpit;
-	tab[msgindex].flags |= flags;
+		link->dumpit = dumpit;
 
-	return 0;
+	link->flags |= flags;
+
+	/* publish protocol:msgtype */
+	rcu_assign_pointer(tab[msgindex], link);
+	ret = 0;
+	if (old)
+		kfree_rcu(old, rcu);
+unlock:
+	rtnl_unlock();
+	return ret;
 }
-EXPORT_SYMBOL_GPL(__rtnl_register);
+
+/**
+ * rtnl_register_module - Register a rtnetlink message type
+ *
+ * @owner: module registering the hook (THIS_MODULE)
+ * @protocol: Protocol family or PF_UNSPEC
+ * @msgtype: rtnetlink message type
+ * @doit: Function pointer called for each request message
+ * @dumpit: Function pointer called for each dump request (NLM_F_DUMP) message
+ * @flags: rtnl_link_flags to modifiy behaviour of doit/dumpit functions
+ *
+ * Like rtnl_register, but for use by removable modules.
+ */
+int rtnl_register_module(struct module *owner,
+			 int protocol, int msgtype,
+			 rtnl_doit_func doit, rtnl_dumpit_func dumpit,
+			 unsigned int flags)
+{
+	return rtnl_register_internal(owner, protocol, msgtype,
+				      doit, dumpit, flags);
+}
+EXPORT_SYMBOL_GPL(rtnl_register_module);
 
 /**
  * rtnl_register - Register a rtnetlink message type
+ * @protocol: Protocol family or PF_UNSPEC
+ * @msgtype: rtnetlink message type
+ * @doit: Function pointer called for each request message
+ * @dumpit: Function pointer called for each dump request (NLM_F_DUMP) message
+ * @flags: rtnl_link_flags to modifiy behaviour of doit/dumpit functions
+ *
+ * Registers the specified function pointers (at least one of them has
+ * to be non-NULL) to be called whenever a request message for the
+ * specified protocol family and message type is received.
  *
- * Identical to __rtnl_register() but panics on failure. This is useful
- * as failure of this function is very unlikely, it can only happen due
- * to lack of memory when allocating the chain to store all message
- * handlers for a protocol. Meant for use in init functions where lack
- * of memory implies no sense in continuing.
+ * The special protocol family PF_UNSPEC may be used to define fallback
+ * function pointers for the case when no entry for the specific protocol
+ * family exists.
  */
 void rtnl_register(int protocol, int msgtype,
 		   rtnl_doit_func doit, rtnl_dumpit_func dumpit,
 		   unsigned int flags)
 {
-	if (__rtnl_register(protocol, msgtype, doit, dumpit, flags) < 0)
-		panic("Unable to register rtnetlink message handler, "
-		      "protocol = %d, message type = %d\n",
-		      protocol, msgtype);
+	int err;
+
+	err = rtnl_register_internal(NULL, protocol, msgtype, doit, dumpit,
+				     flags);
+	if (err)
+		pr_err("Unable to register rtnetlink message handler, "
+		       "protocol = %d, message type = %d\n", protocol, msgtype);
 }
-EXPORT_SYMBOL_GPL(rtnl_register);
 
 /**
  * rtnl_unregister - Unregister a rtnetlink message type
@@ -220,24 +276,25 @@ EXPORT_SYMBOL_GPL(rtnl_register);
  */
 int rtnl_unregister(int protocol, int msgtype)
 {
-	struct rtnl_link *handlers;
+	struct rtnl_link **tab, *link;
 	int msgindex;
 
 	BUG_ON(protocol < 0 || protocol > RTNL_FAMILY_MAX);
 	msgindex = rtm_msgindex(msgtype);
 
 	rtnl_lock();
-	handlers = rtnl_dereference(rtnl_msg_handlers[protocol]);
-	if (!handlers) {
+	tab = rtnl_dereference(rtnl_msg_handlers[protocol]);
+	if (!tab) {
 		rtnl_unlock();
 		return -ENOENT;
 	}
 
-	handlers[msgindex].doit = NULL;
-	handlers[msgindex].dumpit = NULL;
-	handlers[msgindex].flags = 0;
+	link = tab[msgindex];
+	rcu_assign_pointer(tab[msgindex], NULL);
 	rtnl_unlock();
 
+	kfree_rcu(link, rcu);
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(rtnl_unregister);
@@ -251,20 +308,27 @@ EXPORT_SYMBOL_GPL(rtnl_unregister);
  */
 void rtnl_unregister_all(int protocol)
 {
-	struct rtnl_link *handlers;
+	struct rtnl_link **tab, *link;
+	int msgindex;
 
 	BUG_ON(protocol < 0 || protocol > RTNL_FAMILY_MAX);
 
 	rtnl_lock();
-	handlers = rtnl_dereference(rtnl_msg_handlers[protocol]);
+	tab = rtnl_msg_handlers[protocol];
 	RCU_INIT_POINTER(rtnl_msg_handlers[protocol], NULL);
+	for (msgindex = 0; msgindex < RTM_NR_MSGTYPES; msgindex++) {
+		link = tab[msgindex];
+		if (!link)
+			continue;
+
+		rcu_assign_pointer(tab[msgindex], NULL);
+		kfree_rcu(link, rcu);
+	}
 	rtnl_unlock();
 
 	synchronize_net();
 
-	while (refcount_read(&rtnl_msg_handlers_ref[protocol]) > 1)
-		schedule();
-	kfree(handlers);
+	kfree(tab);
 }
 EXPORT_SYMBOL_GPL(rtnl_unregister_all);
 
@@ -840,6 +904,10 @@ static inline int rtnl_vfinfo_size(const struct net_device *dev,
 			 nla_total_size_64bit(sizeof(__u64)) +
 			 /* IFLA_VF_STATS_MULTICAST */
 			 nla_total_size_64bit(sizeof(__u64)) +
+			 /* IFLA_VF_STATS_RX_DROPPED */
+			 nla_total_size_64bit(sizeof(__u64)) +
+			 /* IFLA_VF_STATS_TX_DROPPED */
+			 nla_total_size_64bit(sizeof(__u64)) +
 			 nla_total_size(sizeof(struct ifla_vf_trust)));
 		return size;
 	} else
@@ -920,8 +988,11 @@ static noinline size_t if_nlmsg_size(const struct net_device *dev,
 	       + rtnl_xdp_size() /* IFLA_XDP */
 	       + nla_total_size(4)  /* IFLA_EVENT */
 	       + nla_total_size(4)  /* IFLA_NEW_NETNSID */
+	       + nla_total_size(4)  /* IFLA_NEW_IFINDEX */
 	       + nla_total_size(1)  /* IFLA_PROTO_DOWN */
 	       + nla_total_size(4)  /* IFLA_IF_NETNSID */
+	       + nla_total_size(4)  /* IFLA_CARRIER_UP_COUNT */
+	       + nla_total_size(4)  /* IFLA_CARRIER_DOWN_COUNT */
 	       + 0;
 }
 
@@ -1194,7 +1265,11 @@ static noinline_for_stack int rtnl_fill_vfinfo(struct sk_buff *skb,
 	    nla_put_u64_64bit(skb, IFLA_VF_STATS_BROADCAST,
 			      vf_stats.broadcast, IFLA_VF_STATS_PAD) ||
 	    nla_put_u64_64bit(skb, IFLA_VF_STATS_MULTICAST,
-			      vf_stats.multicast, IFLA_VF_STATS_PAD)) {
+			      vf_stats.multicast, IFLA_VF_STATS_PAD) ||
+	    nla_put_u64_64bit(skb, IFLA_VF_STATS_RX_DROPPED,
+			      vf_stats.rx_dropped, IFLA_VF_STATS_PAD) ||
+	    nla_put_u64_64bit(skb, IFLA_VF_STATS_TX_DROPPED,
+			      vf_stats.tx_dropped, IFLA_VF_STATS_PAD)) {
 		nla_nest_cancel(skb, vfstats);
 		goto nla_put_vf_failure;
 	}
@@ -1261,6 +1336,7 @@ static u8 rtnl_xdp_attached_mode(struct net_device *dev, u32 *prog_id)
 {
 	const struct net_device_ops *ops = dev->netdev_ops;
 	const struct bpf_prog *generic_xdp_prog;
+	struct netdev_bpf xdp;
 
 	ASSERT_RTNL();
 
@@ -1273,7 +1349,10 @@ static u8 rtnl_xdp_attached_mode(struct net_device *dev, u32 *prog_id)
 	if (!ops->ndo_bpf)
 		return XDP_ATTACHED_NONE;
 
-	return __dev_xdp_attached(dev, ops->ndo_bpf, prog_id);
+	__dev_xdp_query(dev, ops->ndo_bpf, &xdp);
+	*prog_id = xdp.prog_id;
+
+	return xdp.prog_attached;
 }
 
 static int rtnl_xdp_fill(struct sk_buff *skb, struct net_device *dev)
@@ -1433,7 +1512,8 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb,
 			    struct net_device *dev, struct net *src_net,
 			    int type, u32 pid, u32 seq, u32 change,
 			    unsigned int flags, u32 ext_filter_mask,
-			    u32 event, int *new_nsid, int tgt_netnsid)
+			    u32 event, int *new_nsid, int new_ifindex,
+			    int tgt_netnsid)
 {
 	struct ifinfomsg *ifm;
 	struct nlmsghdr *nlh;
@@ -1475,8 +1555,13 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb,
 	     nla_put_string(skb, IFLA_QDISC, dev->qdisc->ops->id)) ||
 	    nla_put_ifalias(skb, dev) ||
 	    nla_put_u32(skb, IFLA_CARRIER_CHANGES,
-			atomic_read(&dev->carrier_changes)) ||
-	    nla_put_u8(skb, IFLA_PROTO_DOWN, dev->proto_down))
+			atomic_read(&dev->carrier_up_count) +
+			atomic_read(&dev->carrier_down_count)) ||
+	    nla_put_u8(skb, IFLA_PROTO_DOWN, dev->proto_down) ||
+	    nla_put_u32(skb, IFLA_CARRIER_UP_COUNT,
+			atomic_read(&dev->carrier_up_count)) ||
+	    nla_put_u32(skb, IFLA_CARRIER_DOWN_COUNT,
+			atomic_read(&dev->carrier_down_count)))
 		goto nla_put_failure;
 
 	if (event != IFLA_EVENT_NONE) {
@@ -1525,6 +1610,10 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb,
 	if (new_nsid &&
 	    nla_put_s32(skb, IFLA_NEW_NETNSID, *new_nsid) < 0)
 		goto nla_put_failure;
+	if (new_ifindex &&
+	    nla_put_s32(skb, IFLA_NEW_IFINDEX, new_ifindex) < 0)
+		goto nla_put_failure;
+
 
 	rcu_read_lock();
 	if (rtnl_fill_link_af(skb, dev, ext_filter_mask))
@@ -1569,6 +1658,8 @@ static const struct nla_policy ifla_policy[IFLA_MAX+1] = {
 	[IFLA_PROMISCUITY]	= { .type = NLA_U32 },
 	[IFLA_NUM_TX_QUEUES]	= { .type = NLA_U32 },
 	[IFLA_NUM_RX_QUEUES]	= { .type = NLA_U32 },
+	[IFLA_GSO_MAX_SEGS]	= { .type = NLA_U32 },
+	[IFLA_GSO_MAX_SIZE]	= { .type = NLA_U32 },
 	[IFLA_PHYS_PORT_ID]	= { .type = NLA_BINARY, .len = MAX_PHYS_ITEM_ID_LEN },
 	[IFLA_CARRIER_CHANGES]	= { .type = NLA_U32 },  /* ignored */
 	[IFLA_PHYS_SWITCH_ID]	= { .type = NLA_BINARY, .len = MAX_PHYS_ITEM_ID_LEN },
@@ -1578,6 +1669,8 @@ static const struct nla_policy ifla_policy[IFLA_MAX+1] = {
 	[IFLA_EVENT]		= { .type = NLA_U32 },
 	[IFLA_GROUP]		= { .type = NLA_U32 },
 	[IFLA_IF_NETNSID]	= { .type = NLA_S32 },
+	[IFLA_CARRIER_UP_COUNT]	= { .type = NLA_U32 },
+	[IFLA_CARRIER_DOWN_COUNT] = { .type = NLA_U32 },
 };
 
 static const struct nla_policy ifla_info_policy[IFLA_INFO_MAX+1] = {
@@ -1766,7 +1859,7 @@ static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
 					       NETLINK_CB(cb->skb).portid,
 					       cb->nlh->nlmsg_seq, 0,
 					       flags,
-					       ext_filter_mask, 0, NULL,
+					       ext_filter_mask, 0, NULL, 0,
 					       netnsid);
 
 			if (err < 0) {
@@ -1815,6 +1908,49 @@ struct net *rtnl_link_get_net(struct net *src_net, struct nlattr *tb[])
 }
 EXPORT_SYMBOL(rtnl_link_get_net);
 
+/* Figure out which network namespace we are talking about by
+ * examining the link attributes in the following order:
+ *
+ * 1. IFLA_NET_NS_PID
+ * 2. IFLA_NET_NS_FD
+ * 3. IFLA_IF_NETNSID
+ */
+static struct net *rtnl_link_get_net_by_nlattr(struct net *src_net,
+					       struct nlattr *tb[])
+{
+	struct net *net;
+
+	if (tb[IFLA_NET_NS_PID] || tb[IFLA_NET_NS_FD])
+		return rtnl_link_get_net(src_net, tb);
+
+	if (!tb[IFLA_IF_NETNSID])
+		return get_net(src_net);
+
+	net = get_net_ns_by_id(src_net, nla_get_u32(tb[IFLA_IF_NETNSID]));
+	if (!net)
+		return ERR_PTR(-EINVAL);
+
+	return net;
+}
+
+static struct net *rtnl_link_get_net_capable(const struct sk_buff *skb,
+					     struct net *src_net,
+					     struct nlattr *tb[], int cap)
+{
+	struct net *net;
+
+	net = rtnl_link_get_net_by_nlattr(src_net, tb);
+	if (IS_ERR(net))
+		return net;
+
+	if (!netlink_ns_capable(skb, net->user_ns, cap)) {
+		put_net(net);
+		return ERR_PTR(-EPERM);
+	}
+
+	return net;
+}
+
 static int validate_linkmsg(struct net_device *dev, struct nlattr *tb[])
 {
 	if (dev) {
@@ -2077,17 +2213,14 @@ static int do_setlink(const struct sk_buff *skb,
 	const struct net_device_ops *ops = dev->netdev_ops;
 	int err;
 
-	if (tb[IFLA_NET_NS_PID] || tb[IFLA_NET_NS_FD]) {
-		struct net *net = rtnl_link_get_net(dev_net(dev), tb);
+	if (tb[IFLA_NET_NS_PID] || tb[IFLA_NET_NS_FD] || tb[IFLA_IF_NETNSID]) {
+		struct net *net = rtnl_link_get_net_capable(skb, dev_net(dev),
+							    tb, CAP_NET_ADMIN);
 		if (IS_ERR(net)) {
 			err = PTR_ERR(net);
 			goto errout;
 		}
-		if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN)) {
-			put_net(net);
-			err = -EPERM;
-			goto errout;
-		}
+
 		err = dev_change_net_namespace(dev, net, ifname);
 		put_net(net);
 		if (err)
@@ -2204,17 +2337,37 @@ static int do_setlink(const struct sk_buff *skb,
 
 	if (tb[IFLA_TXQLEN]) {
 		unsigned int value = nla_get_u32(tb[IFLA_TXQLEN]);
-		unsigned int orig_len = dev->tx_queue_len;
-
-		if (dev->tx_queue_len ^ value) {
-			dev->tx_queue_len = value;
-			err = call_netdevice_notifiers(
-			      NETDEV_CHANGE_TX_QUEUE_LEN, dev);
-			err = notifier_to_errno(err);
-			if (err) {
-				dev->tx_queue_len = orig_len;
-				goto errout;
-			}
+
+		err = dev_change_tx_queue_len(dev, value);
+		if (err)
+			goto errout;
+		status |= DO_SETLINK_MODIFIED;
+	}
+
+	if (tb[IFLA_GSO_MAX_SIZE]) {
+		u32 max_size = nla_get_u32(tb[IFLA_GSO_MAX_SIZE]);
+
+		if (max_size > GSO_MAX_SIZE) {
+			err = -EINVAL;
+			goto errout;
+		}
+
+		if (dev->gso_max_size ^ max_size) {
+			netif_set_gso_max_size(dev, max_size);
+			status |= DO_SETLINK_MODIFIED;
+		}
+	}
+
+	if (tb[IFLA_GSO_MAX_SEGS]) {
+		u32 max_segs = nla_get_u32(tb[IFLA_GSO_MAX_SEGS]);
+
+		if (max_segs > GSO_MAX_SEGS) {
+			err = -EINVAL;
+			goto errout;
+		}
+
+		if (dev->gso_max_segs ^ max_segs) {
+			dev->gso_max_segs = max_segs;
 			status |= DO_SETLINK_MODIFIED;
 		}
 	}
@@ -2400,9 +2553,6 @@ static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh,
 	if (err < 0)
 		goto errout;
 
-	if (tb[IFLA_IF_NETNSID])
-		return -EOPNOTSUPP;
-
 	if (tb[IFLA_IFNAME])
 		nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
 	else
@@ -2487,36 +2637,53 @@ static int rtnl_dellink(struct sk_buff *skb, struct nlmsghdr *nlh,
 			struct netlink_ext_ack *extack)
 {
 	struct net *net = sock_net(skb->sk);
-	struct net_device *dev;
+	struct net *tgt_net = net;
+	struct net_device *dev = NULL;
 	struct ifinfomsg *ifm;
 	char ifname[IFNAMSIZ];
 	struct nlattr *tb[IFLA_MAX+1];
 	int err;
+	int netnsid = -1;
 
 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy, extack);
 	if (err < 0)
 		return err;
 
-	if (tb[IFLA_IF_NETNSID])
-		return -EOPNOTSUPP;
-
 	if (tb[IFLA_IFNAME])
 		nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
 
+	if (tb[IFLA_IF_NETNSID]) {
+		netnsid = nla_get_s32(tb[IFLA_IF_NETNSID]);
+		tgt_net = get_target_net(NETLINK_CB(skb).sk, netnsid);
+		if (IS_ERR(tgt_net))
+			return PTR_ERR(tgt_net);
+	}
+
+	err = -EINVAL;
 	ifm = nlmsg_data(nlh);
 	if (ifm->ifi_index > 0)
-		dev = __dev_get_by_index(net, ifm->ifi_index);
+		dev = __dev_get_by_index(tgt_net, ifm->ifi_index);
 	else if (tb[IFLA_IFNAME])
-		dev = __dev_get_by_name(net, ifname);
+		dev = __dev_get_by_name(tgt_net, ifname);
 	else if (tb[IFLA_GROUP])
-		return rtnl_group_dellink(net, nla_get_u32(tb[IFLA_GROUP]));
+		err = rtnl_group_dellink(tgt_net, nla_get_u32(tb[IFLA_GROUP]));
 	else
-		return -EINVAL;
+		goto out;
 
-	if (!dev)
-		return -ENODEV;
+	if (!dev) {
+		if (tb[IFLA_IFNAME] || ifm->ifi_index > 0)
+			err = -ENODEV;
 
-	return rtnl_delete_link(dev);
+		goto out;
+	}
+
+	err = rtnl_delete_link(dev);
+
+out:
+	if (netnsid >= 0)
+		put_net(tgt_net);
+
+	return err;
 }
 
 int rtnl_configure_link(struct net_device *dev, const struct ifinfomsg *ifm)
@@ -2583,6 +2750,10 @@ struct net_device *rtnl_create_link(struct net *net,
 		dev->link_mode = nla_get_u8(tb[IFLA_LINKMODE]);
 	if (tb[IFLA_GROUP])
 		dev_set_group(dev, nla_get_u32(tb[IFLA_GROUP]));
+	if (tb[IFLA_GSO_MAX_SIZE])
+		netif_set_gso_max_size(dev, nla_get_u32(tb[IFLA_GSO_MAX_SIZE]));
+	if (tb[IFLA_GSO_MAX_SEGS])
+		dev->gso_max_segs = nla_get_u32(tb[IFLA_GSO_MAX_SEGS]);
 
 	return dev;
 }
@@ -2781,14 +2952,10 @@ replay:
 			name_assign_type = NET_NAME_ENUM;
 		}
 
-		dest_net = rtnl_link_get_net(net, tb);
+		dest_net = rtnl_link_get_net_capable(skb, net, tb, CAP_NET_ADMIN);
 		if (IS_ERR(dest_net))
 			return PTR_ERR(dest_net);
 
-		err = -EPERM;
-		if (!netlink_ns_capable(skb, dest_net->user_ns, CAP_NET_ADMIN))
-			goto out;
-
 		if (tb[IFLA_LINK_NETNSID]) {
 			int id = nla_get_s32(tb[IFLA_LINK_NETNSID]);
 
@@ -2915,7 +3082,7 @@ static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr *nlh,
 	err = rtnl_fill_ifinfo(nskb, dev, net,
 			       RTM_NEWLINK, NETLINK_CB(skb).portid,
 			       nlh->nlmsg_seq, 0, 0, ext_filter_mask,
-			       0, NULL, netnsid);
+			       0, NULL, 0, netnsid);
 	if (err < 0) {
 		/* -EMSGSIZE implies BUG in if_nlmsg_size */
 		WARN_ON(err == -EMSGSIZE);
@@ -2973,18 +3140,26 @@ static int rtnl_dump_all(struct sk_buff *skb, struct netlink_callback *cb)
 		s_idx = 1;
 
 	for (idx = 1; idx <= RTNL_FAMILY_MAX; idx++) {
+		struct rtnl_link **tab;
 		int type = cb->nlh->nlmsg_type-RTM_BASE;
-		struct rtnl_link *handlers;
+		struct rtnl_link *link;
 		rtnl_dumpit_func dumpit;
 
 		if (idx < s_idx || idx == PF_PACKET)
 			continue;
 
-		handlers = rtnl_dereference(rtnl_msg_handlers[idx]);
-		if (!handlers)
+		if (type < 0 || type >= RTM_NR_MSGTYPES)
 			continue;
 
-		dumpit = READ_ONCE(handlers[type].dumpit);
+		tab = rcu_dereference_rtnl(rtnl_msg_handlers[idx]);
+		if (!tab)
+			continue;
+
+		link = tab[type];
+		if (!link)
+			continue;
+
+		dumpit = link->dumpit;
 		if (!dumpit)
 			continue;
 
@@ -3003,7 +3178,8 @@ static int rtnl_dump_all(struct sk_buff *skb, struct netlink_callback *cb)
 
 struct sk_buff *rtmsg_ifinfo_build_skb(int type, struct net_device *dev,
 				       unsigned int change,
-				       u32 event, gfp_t flags, int *new_nsid)
+				       u32 event, gfp_t flags, int *new_nsid,
+				       int new_ifindex)
 {
 	struct net *net = dev_net(dev);
 	struct sk_buff *skb;
@@ -3016,7 +3192,7 @@ struct sk_buff *rtmsg_ifinfo_build_skb(int type, struct net_device *dev,
 
 	err = rtnl_fill_ifinfo(skb, dev, dev_net(dev),
 			       type, 0, 0, change, 0, 0, event,
-			       new_nsid, -1);
+			       new_nsid, new_ifindex, -1);
 	if (err < 0) {
 		/* -EMSGSIZE implies BUG in if_nlmsg_size() */
 		WARN_ON(err == -EMSGSIZE);
@@ -3039,14 +3215,15 @@ void rtmsg_ifinfo_send(struct sk_buff *skb, struct net_device *dev, gfp_t flags)
 
 static void rtmsg_ifinfo_event(int type, struct net_device *dev,
 			       unsigned int change, u32 event,
-			       gfp_t flags, int *new_nsid)
+			       gfp_t flags, int *new_nsid, int new_ifindex)
 {
 	struct sk_buff *skb;
 
 	if (dev->reg_state != NETREG_REGISTERED)
 		return;
 
-	skb = rtmsg_ifinfo_build_skb(type, dev, change, event, flags, new_nsid);
+	skb = rtmsg_ifinfo_build_skb(type, dev, change, event, flags, new_nsid,
+				     new_ifindex);
 	if (skb)
 		rtmsg_ifinfo_send(skb, dev, flags);
 }
@@ -3054,14 +3231,15 @@ static void rtmsg_ifinfo_event(int type, struct net_device *dev,
 void rtmsg_ifinfo(int type, struct net_device *dev, unsigned int change,
 		  gfp_t flags)
 {
-	rtmsg_ifinfo_event(type, dev, change, rtnl_get_event(0), flags, NULL);
+	rtmsg_ifinfo_event(type, dev, change, rtnl_get_event(0), flags,
+			   NULL, 0);
 }
 
 void rtmsg_ifinfo_newnet(int type, struct net_device *dev, unsigned int change,
-			 gfp_t flags, int *new_nsid)
+			 gfp_t flags, int *new_nsid, int new_ifindex)
 {
 	rtmsg_ifinfo_event(type, dev, change, rtnl_get_event(0), flags,
-			   new_nsid);
+			   new_nsid, new_ifindex);
 }
 
 static int nlmsg_populate_fdb_fill(struct sk_buff *skb,
@@ -4314,7 +4492,8 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
 			     struct netlink_ext_ack *extack)
 {
 	struct net *net = sock_net(skb->sk);
-	struct rtnl_link *handlers;
+	struct rtnl_link *link;
+	struct module *owner;
 	int err = -EOPNOTSUPP;
 	rtnl_doit_func doit;
 	unsigned int flags;
@@ -4338,79 +4517,85 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
 	if (kind != 2 && !netlink_net_capable(skb, CAP_NET_ADMIN))
 		return -EPERM;
 
-	if (family >= ARRAY_SIZE(rtnl_msg_handlers))
-		family = PF_UNSPEC;
-
 	rcu_read_lock();
-	handlers = rcu_dereference(rtnl_msg_handlers[family]);
-	if (!handlers) {
-		family = PF_UNSPEC;
-		handlers = rcu_dereference(rtnl_msg_handlers[family]);
-	}
-
 	if (kind == 2 && nlh->nlmsg_flags&NLM_F_DUMP) {
 		struct sock *rtnl;
 		rtnl_dumpit_func dumpit;
 		u16 min_dump_alloc = 0;
 
-		dumpit = READ_ONCE(handlers[type].dumpit);
-		if (!dumpit) {
+		link = rtnl_get_link(family, type);
+		if (!link || !link->dumpit) {
 			family = PF_UNSPEC;
-			handlers = rcu_dereference(rtnl_msg_handlers[PF_UNSPEC]);
-			if (!handlers)
-				goto err_unlock;
-
-			dumpit = READ_ONCE(handlers[type].dumpit);
-			if (!dumpit)
+			link = rtnl_get_link(family, type);
+			if (!link || !link->dumpit)
 				goto err_unlock;
 		}
-
-		refcount_inc(&rtnl_msg_handlers_ref[family]);
+		owner = link->owner;
+		dumpit = link->dumpit;
 
 		if (type == RTM_GETLINK - RTM_BASE)
 			min_dump_alloc = rtnl_calcit(skb, nlh);
 
+		err = 0;
+		/* need to do this before rcu_read_unlock() */
+		if (!try_module_get(owner))
+			err = -EPROTONOSUPPORT;
+
 		rcu_read_unlock();
 
 		rtnl = net->rtnl;
-		{
+		if (err == 0) {
 			struct netlink_dump_control c = {
 				.dump		= dumpit,
 				.min_dump_alloc	= min_dump_alloc,
+				.module		= owner,
 			};
 			err = netlink_dump_start(rtnl, skb, nlh, &c);
+			/* netlink_dump_start() will keep a reference on
+			 * module if dump is still in progress.
+			 */
+			module_put(owner);
 		}
-		refcount_dec(&rtnl_msg_handlers_ref[family]);
 		return err;
 	}
 
-	doit = READ_ONCE(handlers[type].doit);
-	if (!doit) {
+	link = rtnl_get_link(family, type);
+	if (!link || !link->doit) {
 		family = PF_UNSPEC;
-		handlers = rcu_dereference(rtnl_msg_handlers[family]);
+		link = rtnl_get_link(PF_UNSPEC, type);
+		if (!link || !link->doit)
+			goto out_unlock;
+	}
+
+	owner = link->owner;
+	if (!try_module_get(owner)) {
+		err = -EPROTONOSUPPORT;
+		goto out_unlock;
 	}
 
-	flags = READ_ONCE(handlers[type].flags);
+	flags = link->flags;
 	if (flags & RTNL_FLAG_DOIT_UNLOCKED) {
-		refcount_inc(&rtnl_msg_handlers_ref[family]);
-		doit = READ_ONCE(handlers[type].doit);
+		doit = link->doit;
 		rcu_read_unlock();
 		if (doit)
 			err = doit(skb, nlh, extack);
-		refcount_dec(&rtnl_msg_handlers_ref[family]);
+		module_put(owner);
 		return err;
 	}
-
 	rcu_read_unlock();
 
 	rtnl_lock();
-	handlers = rtnl_dereference(rtnl_msg_handlers[family]);
-	if (handlers) {
-		doit = READ_ONCE(handlers[type].doit);
-		if (doit)
-			err = doit(skb, nlh, extack);
-	}
+	link = rtnl_get_link(family, type);
+	if (link && link->doit)
+		err = link->doit(skb, nlh, extack);
 	rtnl_unlock();
+
+	module_put(owner);
+
+	return err;
+
+out_unlock:
+	rcu_read_unlock();
 	return err;
 
 err_unlock:
@@ -4454,7 +4639,7 @@ static int rtnetlink_event(struct notifier_block *this, unsigned long event, voi
 	case NETDEV_CHANGELOWERSTATE:
 	case NETDEV_CHANGE_TX_QUEUE_LEN:
 		rtmsg_ifinfo_event(RTM_NEWLINK, dev, 0, rtnl_get_event(event),
-				   GFP_KERNEL, NULL);
+				   GFP_KERNEL, NULL, 0);
 		break;
 	default:
 		break;
@@ -4498,11 +4683,6 @@ static struct pernet_operations rtnetlink_net_ops = {
 
 void __init rtnetlink_init(void)
 {
-	int i;
-
-	for (i = 0; i < ARRAY_SIZE(rtnl_msg_handlers_ref); i++)
-		refcount_set(&rtnl_msg_handlers_ref[i], 1);
-
 	if (register_pernet_subsys(&rtnetlink_net_ops))
 		panic("rtnetlink_init: cannot initialize rtnetlink\n");