1 files changed, 280 insertions, 116 deletions

diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index eec1f6df80d8..ca9eaee4c2ef 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -42,6 +42,7 @@
 #include <linux/init.h>
 #include <linux/if_ether.h>
 #include <linux/slab.h>
+#include <net/flow.h>
 #include <net/net_namespace.h>
 #include <net/ip.h>
 #include <net/protocol.h>
@@ -62,6 +63,7 @@
 #include <net/fib_rules.h>
 #include <linux/netconf.h>
 #include <net/rtnh.h>
+#include <net/inet_dscp.h>
 
 #include <linux/nospec.h>
 
@@ -136,7 +138,7 @@ static struct mr_table *ipmr_mr_table_iter(struct net *net,
 	return ret;
 }
 
-static struct mr_table *ipmr_get_table(struct net *net, u32 id)
+static struct mr_table *__ipmr_get_table(struct net *net, u32 id)
 {
 	struct mr_table *mrt;
 
@@ -147,6 +149,16 @@ static struct mr_table *ipmr_get_table(struct net *net, u32 id)
 	return NULL;
 }
 
+static struct mr_table *ipmr_get_table(struct net *net, u32 id)
+{
+	struct mr_table *mrt;
+
+	rcu_read_lock();
+	mrt = __ipmr_get_table(net, id);
+	rcu_read_unlock();
+	return mrt;
+}
+
 static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
 			   struct mr_table **mrt)
 {
@@ -188,7 +200,7 @@ static int ipmr_rule_action(struct fib_rule *rule, struct flowi *flp,
 
 	arg->table = fib_rule_get_table(rule, arg);
 
-	mrt = ipmr_get_table(rule->fr_net, arg->table);
+	mrt = __ipmr_get_table(rule->fr_net, arg->table);
 	if (!mrt)
 		return -EAGAIN;
 	res->mrt = mrt;
@@ -253,7 +265,7 @@ static int __net_init ipmr_rules_init(struct net *net)
 		goto err1;
 	}
 
-	err = fib_default_rule_add(ops, 0x7fff, RT_TABLE_DEFAULT, 0);
+	err = fib_default_rule_add(ops, 0x7fff, RT_TABLE_DEFAULT);
 	if (err < 0)
 		goto err2;
 
@@ -287,7 +299,7 @@ static int ipmr_rules_dump(struct net *net, struct notifier_block *nb,
 	return fib_rules_dump(net, nb, RTNL_FAMILY_IPMR, extack);
 }
 
-static unsigned int ipmr_rules_seq_read(struct net *net)
+static unsigned int ipmr_rules_seq_read(const struct net *net)
 {
 	return fib_rules_seq_read(net, RTNL_FAMILY_IPMR);
 }
@@ -314,6 +326,8 @@ static struct mr_table *ipmr_get_table(struct net *net, u32 id)
 	return net->ipv4.mrt;
 }
 
+#define __ipmr_get_table ipmr_get_table
+
 static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
 			   struct mr_table **mrt)
 {
@@ -345,7 +359,7 @@ static int ipmr_rules_dump(struct net *net, struct notifier_block *nb,
 	return 0;
 }
 
-static unsigned int ipmr_rules_seq_read(struct net *net)
+static unsigned int ipmr_rules_seq_read(const struct net *net)
 {
 	return 0;
 }
@@ -402,7 +416,7 @@ static struct mr_table *ipmr_new_table(struct net *net, u32 id)
 	if (id != RT_TABLE_DEFAULT && id >= 1000000000)
 		return ERR_PTR(-EINVAL);
 
-	mrt = ipmr_get_table(net, id);
+	mrt = __ipmr_get_table(net, id);
 	if (mrt)
 		return mrt;
 
@@ -412,6 +426,10 @@ static struct mr_table *ipmr_new_table(struct net *net, u32 id)
 
 static void ipmr_free_table(struct mr_table *mrt)
 {
+	struct net *net = read_pnet(&mrt->net);
+
+	WARN_ON_ONCE(!mr_can_free_table(net));
+
 	timer_shutdown_sync(&mrt->ipmr_expire_timer);
 	mroute_clean_tables(mrt, MRT_FLUSH_VIFS | MRT_FLUSH_VIFS_STATIC |
 				 MRT_FLUSH_MFC | MRT_FLUSH_MFC_STATIC);
@@ -441,7 +459,7 @@ static bool ipmr_init_vif_indev(const struct net_device *dev)
 static struct net_device *ipmr_new_tunnel(struct net *net, struct vifctl *v)
 {
 	struct net_device *tunnel_dev, *new_dev;
-	struct ip_tunnel_parm p = { };
+	struct ip_tunnel_parm_kern p = { };
 	int err;
 
 	tunnel_dev = __dev_get_by_name(net, "tunl0");
@@ -536,7 +554,7 @@ static void reg_vif_setup(struct net_device *dev)
 	dev->flags		= IFF_NOARP;
 	dev->netdev_ops		= &reg_vif_netdev_ops;
 	dev->needs_free_netdev	= true;
-	dev->features		|= NETIF_F_NETNS_LOCAL;
+	dev->netns_immutable	= true;
 }
 
 static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
@@ -748,7 +766,7 @@ static void ipmr_destroy_unres(struct mr_table *mrt, struct mfc_cache *c)
 /* Timer process for the unresolved queue. */
 static void ipmr_expire_process(struct timer_list *t)
 {
-	struct mr_table *mrt = from_timer(mrt, t, ipmr_expire_timer);
+	struct mr_table *mrt = timer_container_of(mrt, t, ipmr_expire_timer);
 	struct mr_mfc *c, *next;
 	unsigned long expires;
 	unsigned long now;
@@ -804,7 +822,7 @@ static void ipmr_update_thresholds(struct mr_table *mrt, struct mr_mfc *cache,
 				cache->mfc_un.res.maxvif = vifi + 1;
 		}
 	}
-	cache->mfc_un.res.lastuse = jiffies;
+	WRITE_ONCE(cache->mfc_un.res.lastuse, jiffies);
 }
 
 static int vif_add(struct net *net, struct mr_table *mrt,
@@ -884,7 +902,7 @@ static int vif_add(struct net *net, struct mr_table *mrt,
 			vifc->vifc_flags | (!mrtsock ? VIFF_STATIC : 0),
 			(VIFF_TUNNEL | VIFF_REGISTER));
 
-	err = dev_get_port_parent_id(dev, &ppid, true);
+	err = netif_get_port_parent_id(dev, &ppid, true);
 	if (err == 0) {
 		memcpy(v->dev_parent_id.id, ppid.id, ppid.id_len);
 		v->dev_parent_id.id_len = ppid.id_len;
@@ -1025,6 +1043,10 @@ static int ipmr_cache_report(const struct mr_table *mrt,
 	struct sk_buff *skb;
 	int ret;
 
+	mroute_sk = rcu_dereference(mrt->mroute_sk);
+	if (!mroute_sk)
+		return -EINVAL;
+
 	if (assert == IGMPMSG_WHOLEPKT || assert == IGMPMSG_WRVIFWHOLE)
 		skb = skb_realloc_headroom(pkt, sizeof(struct iphdr));
 	else
@@ -1069,7 +1091,8 @@ static int ipmr_cache_report(const struct mr_table *mrt,
 		msg = (struct igmpmsg *)skb_network_header(skb);
 		msg->im_vif = vifi;
 		msg->im_vif_hi = vifi >> 8;
-		skb_dst_set(skb, dst_clone(skb_dst(pkt)));
+		ipv4_pktinfo_prepare(mroute_sk, pkt, false);
+		memcpy(skb->cb, pkt->cb, sizeof(skb->cb));
 		/* Add our header */
 		igmp = skb_put(skb, sizeof(struct igmphdr));
 		igmp->type = assert;
@@ -1079,12 +1102,6 @@ static int ipmr_cache_report(const struct mr_table *mrt,
 		skb->transport_header = skb->network_header;
 	}
 
-	mroute_sk = rcu_dereference(mrt->mroute_sk);
-	if (!mroute_sk) {
-		kfree_skb(skb);
-		return -EINVAL;
-	}
-
 	igmpmsg_netlink_event(mrt, skb);
 
 	/* Deliver to mrouted */
@@ -1263,7 +1280,7 @@ static int ipmr_mfc_add(struct net *net, struct mr_table *mrt,
 		}
 	}
 	if (list_empty(&mrt->mfc_unres_queue))
-		del_timer(&mrt->ipmr_expire_timer);
+		timer_delete(&mrt->ipmr_expire_timer);
 	spin_unlock_bh(&mfc_unres_lock);
 
 	if (found) {
@@ -1374,7 +1391,7 @@ int ip_mroute_setsockopt(struct sock *sk, int optname, sockptr_t optval,
 		goto out_unlock;
 	}
 
-	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
+	mrt = __ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
 	if (!mrt) {
 		ret = -ENOENT;
 		goto out_unlock;
@@ -1547,6 +1564,28 @@ out:
 	return ret;
 }
 
+/* Execute if this ioctl is a special mroute ioctl */
+int ipmr_sk_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
+{
+	switch (cmd) {
+	/* These userspace buffers will be consumed by ipmr_ioctl() */
+	case SIOCGETVIFCNT: {
+		struct sioc_vif_req buffer;
+
+		return sock_ioctl_inout(sk, cmd, arg, &buffer,
+				      sizeof(buffer));
+		}
+	case SIOCGETSGCNT: {
+		struct sioc_sg_req buffer;
+
+		return sock_ioctl_inout(sk, cmd, arg, &buffer,
+				      sizeof(buffer));
+		}
+	}
+	/* return code > 0 means that the ioctl was not executed */
+	return 1;
+}
+
 /* Getsock opt support for the multicast routing system. */
 int ip_mroute_getsockopt(struct sock *sk, int optname, sockptr_t optval,
 			 sockptr_t optlen)
@@ -1582,9 +1621,11 @@ int ip_mroute_getsockopt(struct sock *sk, int optname, sockptr_t optval,
 
 	if (copy_from_sockptr(&olr, optlen, sizeof(int)))
 		return -EFAULT;
-	olr = min_t(unsigned int, olr, sizeof(int));
 	if (olr < 0)
 		return -EINVAL;
+
+	olr = min_t(unsigned int, olr, sizeof(int));
+
 	if (copy_to_sockptr(optlen, &olr, sizeof(int)))
 		return -EFAULT;
 	if (copy_to_sockptr(optval, &val, olr))
@@ -1593,13 +1634,13 @@ int ip_mroute_getsockopt(struct sock *sk, int optname, sockptr_t optval,
 }
 
 /* The IP multicast ioctl support routines. */
-int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg)
+int ipmr_ioctl(struct sock *sk, int cmd, void *arg)
 {
-	struct sioc_sg_req sr;
-	struct sioc_vif_req vr;
 	struct vif_device *vif;
 	struct mfc_cache *c;
 	struct net *net = sock_net(sk);
+	struct sioc_vif_req *vr;
+	struct sioc_sg_req *sr;
 	struct mr_table *mrt;
 
 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
@@ -1608,40 +1649,33 @@ int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg)
 
 	switch (cmd) {
 	case SIOCGETVIFCNT:
-		if (copy_from_user(&vr, arg, sizeof(vr)))
-			return -EFAULT;
-		if (vr.vifi >= mrt->maxvif)
+		vr = (struct sioc_vif_req *)arg;
+		if (vr->vifi >= mrt->maxvif)
 			return -EINVAL;
-		vr.vifi = array_index_nospec(vr.vifi, mrt->maxvif);
+		vr->vifi = array_index_nospec(vr->vifi, mrt->maxvif);
 		rcu_read_lock();
-		vif = &mrt->vif_table[vr.vifi];
-		if (VIF_EXISTS(mrt, vr.vifi)) {
-			vr.icount = READ_ONCE(vif->pkt_in);
-			vr.ocount = READ_ONCE(vif->pkt_out);
-			vr.ibytes = READ_ONCE(vif->bytes_in);
-			vr.obytes = READ_ONCE(vif->bytes_out);
+		vif = &mrt->vif_table[vr->vifi];
+		if (VIF_EXISTS(mrt, vr->vifi)) {
+			vr->icount = READ_ONCE(vif->pkt_in);
+			vr->ocount = READ_ONCE(vif->pkt_out);
+			vr->ibytes = READ_ONCE(vif->bytes_in);
+			vr->obytes = READ_ONCE(vif->bytes_out);
 			rcu_read_unlock();
 
-			if (copy_to_user(arg, &vr, sizeof(vr)))
-				return -EFAULT;
 			return 0;
 		}
 		rcu_read_unlock();
 		return -EADDRNOTAVAIL;
 	case SIOCGETSGCNT:
-		if (copy_from_user(&sr, arg, sizeof(sr)))
-			return -EFAULT;
+		sr = (struct sioc_sg_req *)arg;
 
 		rcu_read_lock();
-		c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
+		c = ipmr_cache_find(mrt, sr->src.s_addr, sr->grp.s_addr);
 		if (c) {
-			sr.pktcnt = c->_c.mfc_un.res.pkt;
-			sr.bytecnt = c->_c.mfc_un.res.bytes;
-			sr.wrong_if = c->_c.mfc_un.res.wrong_if;
+			sr->pktcnt = atomic_long_read(&c->_c.mfc_un.res.pkt);
+			sr->bytecnt = atomic_long_read(&c->_c.mfc_un.res.bytes);
+			sr->wrong_if = atomic_long_read(&c->_c.mfc_un.res.wrong_if);
 			rcu_read_unlock();
-
-			if (copy_to_user(arg, &sr, sizeof(sr)))
-				return -EFAULT;
 			return 0;
 		}
 		rcu_read_unlock();
@@ -1710,9 +1744,9 @@ int ipmr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
 		rcu_read_lock();
 		c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
 		if (c) {
-			sr.pktcnt = c->_c.mfc_un.res.pkt;
-			sr.bytecnt = c->_c.mfc_un.res.bytes;
-			sr.wrong_if = c->_c.mfc_un.res.wrong_if;
+			sr.pktcnt = atomic_long_read(&c->_c.mfc_un.res.pkt);
+			sr.bytecnt = atomic_long_read(&c->_c.mfc_un.res.bytes);
+			sr.wrong_if = atomic_long_read(&c->_c.mfc_un.res.wrong_if);
 			rcu_read_unlock();
 
 			if (copy_to_user(arg, &sr, sizeof(sr)))
@@ -1789,7 +1823,6 @@ static inline int ipmr_forward_finish(struct net *net, struct sock *sk,
 	struct ip_options *opt = &(IPCB(skb)->opt);
 
 	IP_INC_STATS(net, IPSTATS_MIB_OUTFORWDATAGRAMS);
-	IP_ADD_STATS(net, IPSTATS_MIB_OUTOCTETS, skb->len);
 
 	if (unlikely(opt->optlen))
 		ip_forward_options(skb);
@@ -1821,20 +1854,19 @@ static bool ipmr_forward_offloaded(struct sk_buff *skb, struct mr_table *mrt,
 
 /* Processing handlers for ipmr_forward, under rcu_read_lock() */
 
-static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt,
-			    int in_vifi, struct sk_buff *skb, int vifi)
+static int ipmr_prepare_xmit(struct net *net, struct mr_table *mrt,
+			     struct sk_buff *skb, int vifi)
 {
 	const struct iphdr *iph = ip_hdr(skb);
 	struct vif_device *vif = &mrt->vif_table[vifi];
 	struct net_device *vif_dev;
-	struct net_device *dev;
 	struct rtable *rt;
 	struct flowi4 fl4;
 	int    encap = 0;
 
 	vif_dev = vif_dev_read(vif);
 	if (!vif_dev)
-		goto out_free;
+		return -1;
 
 	if (vif->flags & VIFF_REGISTER) {
 		WRITE_ONCE(vif->pkt_out, vif->pkt_out + 1);
@@ -1842,32 +1874,27 @@ static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt,
 		DEV_STATS_ADD(vif_dev, tx_bytes, skb->len);
 		DEV_STATS_INC(vif_dev, tx_packets);
 		ipmr_cache_report(mrt, skb, vifi, IGMPMSG_WHOLEPKT);
-		goto out_free;
+		return -1;
 	}
 
-	if (ipmr_forward_offloaded(skb, mrt, in_vifi, vifi))
-		goto out_free;
-
 	if (vif->flags & VIFF_TUNNEL) {
 		rt = ip_route_output_ports(net, &fl4, NULL,
 					   vif->remote, vif->local,
 					   0, 0,
 					   IPPROTO_IPIP,
-					   RT_TOS(iph->tos), vif->link);
+					   iph->tos & INET_DSCP_MASK, vif->link);
 		if (IS_ERR(rt))
-			goto out_free;
+			return -1;
 		encap = sizeof(struct iphdr);
 	} else {
 		rt = ip_route_output_ports(net, &fl4, NULL, iph->daddr, 0,
 					   0, 0,
 					   IPPROTO_IPIP,
-					   RT_TOS(iph->tos), vif->link);
+					   iph->tos & INET_DSCP_MASK, vif->link);
 		if (IS_ERR(rt))
-			goto out_free;
+			return -1;
 	}
 
-	dev = rt->dst.dev;
-
 	if (skb->len+encap > dst_mtu(&rt->dst) && (ntohs(iph->frag_off) & IP_DF)) {
 		/* Do not fragment multicasts. Alas, IPv4 does not
 		 * allow to send ICMP, so that packets will disappear
@@ -1875,14 +1902,14 @@ static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt,
 		 */
 		IP_INC_STATS(net, IPSTATS_MIB_FRAGFAILS);
 		ip_rt_put(rt);
-		goto out_free;
+		return -1;
 	}
 
-	encap += LL_RESERVED_SPACE(dev) + rt->dst.header_len;
+	encap += LL_RESERVED_SPACE(dst_dev_rcu(&rt->dst)) + rt->dst.header_len;
 
 	if (skb_cow(skb, encap)) {
 		ip_rt_put(rt);
-		goto out_free;
+		return -1;
 	}
 
 	WRITE_ONCE(vif->pkt_out, vif->pkt_out + 1);
@@ -1902,6 +1929,22 @@ static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt,
 		DEV_STATS_ADD(vif_dev, tx_bytes, skb->len);
 	}
 
+	return 0;
+}
+
+static void ipmr_queue_fwd_xmit(struct net *net, struct mr_table *mrt,
+				int in_vifi, struct sk_buff *skb, int vifi)
+{
+	struct rtable *rt;
+
+	if (ipmr_forward_offloaded(skb, mrt, in_vifi, vifi))
+		goto out_free;
+
+	if (ipmr_prepare_xmit(net, mrt, skb, vifi))
+		goto out_free;
+
+	rt = skb_rtable(skb);
+
 	IPCB(skb)->flags |= IPSKB_FORWARDED;
 
 	/* RFC1584 teaches, that DVMRP/PIM router must deliver packets locally
@@ -1915,7 +1958,7 @@ static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt,
 	 * result in receiving multiple packets.
 	 */
 	NF_HOOK(NFPROTO_IPV4, NF_INET_FORWARD,
-		net, NULL, skb, skb->dev, dev,
+		net, NULL, skb, skb->dev, dst_dev_rcu(&rt->dst),
 		ipmr_forward_finish);
 	return;
 
@@ -1923,6 +1966,19 @@ out_free:
 	kfree_skb(skb);
 }
 
+static void ipmr_queue_output_xmit(struct net *net, struct mr_table *mrt,
+				   struct sk_buff *skb, int vifi)
+{
+	if (ipmr_prepare_xmit(net, mrt, skb, vifi))
+		goto out_free;
+
+	ip_mc_output(net, NULL, skb);
+	return;
+
+out_free:
+	kfree_skb(skb);
+}
+
 /* Called with mrt_lock or rcu_read_lock() */
 static int ipmr_find_vif(const struct mr_table *mrt, struct net_device *dev)
 {
@@ -1946,9 +2002,9 @@ static void ip_mr_forward(struct net *net, struct mr_table *mrt,
 	int vif, ct;
 
 	vif = c->_c.mfc_parent;
-	c->_c.mfc_un.res.pkt++;
-	c->_c.mfc_un.res.bytes += skb->len;
-	c->_c.mfc_un.res.lastuse = jiffies;
+	atomic_long_inc(&c->_c.mfc_un.res.pkt);
+	atomic_long_add(skb->len, &c->_c.mfc_un.res.bytes);
+	WRITE_ONCE(c->_c.mfc_un.res.lastuse, jiffies);
 
 	if (c->mfc_origin == htonl(INADDR_ANY) && true_vifi >= 0) {
 		struct mfc_cache *cache_proxy;
@@ -1979,7 +2035,7 @@ static void ip_mr_forward(struct net *net, struct mr_table *mrt,
 			goto dont_forward;
 		}
 
-		c->_c.mfc_un.res.wrong_if++;
+		atomic_long_inc(&c->_c.mfc_un.res.wrong_if);
 
 		if (true_vifi >= 0 && mrt->mroute_do_assert &&
 		    /* pimsm uses asserts, when switching from RPT to SPT,
@@ -2033,8 +2089,8 @@ forward:
 				struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
 
 				if (skb2)
-					ipmr_queue_xmit(net, mrt, true_vifi,
-							skb2, psend);
+					ipmr_queue_fwd_xmit(net, mrt, true_vifi,
+							    skb2, psend);
 			}
 			psend = ct;
 		}
@@ -2045,10 +2101,10 @@ last_forward:
 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
 
 			if (skb2)
-				ipmr_queue_xmit(net, mrt, true_vifi, skb2,
-						psend);
+				ipmr_queue_fwd_xmit(net, mrt, true_vifi, skb2,
+						    psend);
 		} else {
-			ipmr_queue_xmit(net, mrt, true_vifi, skb, psend);
+			ipmr_queue_fwd_xmit(net, mrt, true_vifi, skb, psend);
 			return;
 		}
 	}
@@ -2065,7 +2121,7 @@ static struct mr_table *ipmr_rt_fib_lookup(struct net *net, struct sk_buff *skb)
 	struct flowi4 fl4 = {
 		.daddr = iph->daddr,
 		.saddr = iph->saddr,
-		.flowi4_tos = RT_TOS(iph->tos),
+		.flowi4_dscp = ip4h_dscp(iph),
 		.flowi4_oif = (rt_is_output_route(rt) ?
 			       skb->dev->ifindex : 0),
 		.flowi4_iif = (rt_is_output_route(rt) ?
@@ -2182,6 +2238,110 @@ dont_forward:
 	return 0;
 }
 
+static void ip_mr_output_finish(struct net *net, struct mr_table *mrt,
+				struct net_device *dev, struct sk_buff *skb,
+				struct mfc_cache *c)
+{
+	int psend = -1;
+	int ct;
+
+	atomic_long_inc(&c->_c.mfc_un.res.pkt);
+	atomic_long_add(skb->len, &c->_c.mfc_un.res.bytes);
+	WRITE_ONCE(c->_c.mfc_un.res.lastuse, jiffies);
+
+	/* Forward the frame */
+	if (c->mfc_origin == htonl(INADDR_ANY) &&
+	    c->mfc_mcastgrp == htonl(INADDR_ANY)) {
+		if (ip_hdr(skb)->ttl >
+		    c->_c.mfc_un.res.ttls[c->_c.mfc_parent]) {
+			/* It's an (*,*) entry and the packet is not coming from
+			 * the upstream: forward the packet to the upstream
+			 * only.
+			 */
+			psend = c->_c.mfc_parent;
+			goto last_xmit;
+		}
+		goto dont_xmit;
+	}
+
+	for (ct = c->_c.mfc_un.res.maxvif - 1;
+	     ct >= c->_c.mfc_un.res.minvif; ct--) {
+		if (ip_hdr(skb)->ttl > c->_c.mfc_un.res.ttls[ct]) {
+			if (psend != -1) {
+				struct sk_buff *skb2;
+
+				skb2 = skb_clone(skb, GFP_ATOMIC);
+				if (skb2)
+					ipmr_queue_output_xmit(net, mrt,
+							       skb2, psend);
+			}
+			psend = ct;
+		}
+	}
+
+last_xmit:
+	if (psend != -1) {
+		ipmr_queue_output_xmit(net, mrt, skb, psend);
+		return;
+	}
+
+dont_xmit:
+	kfree_skb(skb);
+}
+
+/* Multicast packets for forwarding arrive here
+ * Called with rcu_read_lock();
+ */
+int ip_mr_output(struct net *net, struct sock *sk, struct sk_buff *skb)
+{
+	struct rtable *rt = skb_rtable(skb);
+	struct mfc_cache *cache;
+	struct net_device *dev;
+	struct mr_table *mrt;
+	int vif;
+
+	guard(rcu)();
+
+	dev = dst_dev_rcu(&rt->dst);
+
+	if (IPCB(skb)->flags & IPSKB_FORWARDED)
+		goto mc_output;
+	if (!(IPCB(skb)->flags & IPSKB_MCROUTE))
+		goto mc_output;
+
+	skb->dev = dev;
+
+	mrt = ipmr_rt_fib_lookup(net, skb);
+	if (IS_ERR(mrt))
+		goto mc_output;
+
+	cache = ipmr_cache_find(mrt, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
+	if (!cache) {
+		vif = ipmr_find_vif(mrt, dev);
+		if (vif >= 0)
+			cache = ipmr_cache_find_any(mrt, ip_hdr(skb)->daddr,
+						    vif);
+	}
+
+	/* No usable cache entry */
+	if (!cache) {
+		vif = ipmr_find_vif(mrt, dev);
+		if (vif >= 0)
+			return ipmr_cache_unresolved(mrt, vif, skb, dev);
+		goto mc_output;
+	}
+
+	vif = cache->_c.mfc_parent;
+	if (rcu_access_pointer(mrt->vif_table[vif].dev) != dev)
+		goto mc_output;
+
+	ip_mr_output_finish(net, mrt, dev, skb, cache);
+	return 0;
+
+mc_output:
+	return ip_mc_output(net, sk, skb);
+}
+
 #ifdef CONFIG_IP_PIMSM_V1
 /* Handle IGMP messages of PIMv1 */
 int pim_rcv_v1(struct sk_buff *skb)
@@ -2246,11 +2406,13 @@ int ipmr_get_route(struct net *net, struct sk_buff *skb,
 	struct mr_table *mrt;
 	int err;
 
-	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
-	if (!mrt)
+	rcu_read_lock();
+	mrt = __ipmr_get_table(net, RT_TABLE_DEFAULT);
+	if (!mrt) {
+		rcu_read_unlock();
 		return -ENOENT;
+	}
 
-	rcu_read_lock();
 	cache = ipmr_cache_find(mrt, saddr, daddr);
 	if (!cache && skb->dev) {
 		int vif = ipmr_find_vif(mrt, skb->dev);
@@ -2391,8 +2553,7 @@ static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
 
 errout:
 	kfree_skb(skb);
-	if (err < 0)
-		rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE, err);
+	rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE, err);
 }
 
 static size_t igmpmsg_netlink_msgsize(size_t payloadlen)
@@ -2468,7 +2629,8 @@ static int ipmr_rtm_valid_getroute_req(struct sk_buff *skb,
 	struct rtmsg *rtm;
 	int i, err;
 
-	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
+	rtm = nlmsg_payload(nlh, sizeof(*rtm));
+	if (!rtm) {
 		NL_SET_ERR_MSG(extack, "ipv4: Invalid header for multicast route get request");
 		return -EINVAL;
 	}
@@ -2477,7 +2639,6 @@ static int ipmr_rtm_valid_getroute_req(struct sk_buff *skb,
 		return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
 					      rtm_ipv4_policy, extack);
 
-	rtm = nlmsg_data(nlh);
 	if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) ||
 	    (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) ||
 	    rtm->rtm_tos || rtm->rtm_table || rtm->rtm_protocol ||
@@ -2531,11 +2692,11 @@ static int ipmr_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
 	if (err < 0)
 		goto errout;
 
-	src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0;
-	grp = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0;
-	tableid = tb[RTA_TABLE] ? nla_get_u32(tb[RTA_TABLE]) : 0;
+	src = nla_get_in_addr_default(tb[RTA_SRC], 0);
+	grp = nla_get_in_addr_default(tb[RTA_DST], 0);
+	tableid = nla_get_u32_default(tb[RTA_TABLE], 0);
 
-	mrt = ipmr_get_table(net, tableid ? tableid : RT_TABLE_DEFAULT);
+	mrt = __ipmr_get_table(net, tableid ? tableid : RT_TABLE_DEFAULT);
 	if (!mrt) {
 		err = -ENOENT;
 		goto errout_free;
@@ -2574,7 +2735,9 @@ errout_free:
 
 static int ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
 {
-	struct fib_dump_filter filter = {};
+	struct fib_dump_filter filter = {
+		.rtnl_held = true,
+	};
 	int err;
 
 	if (cb->strict_check) {
@@ -2587,7 +2750,7 @@ static int ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
 	if (filter.table_id) {
 		struct mr_table *mrt;
 
-		mrt = ipmr_get_table(sock_net(skb->sk), filter.table_id);
+		mrt = __ipmr_get_table(sock_net(skb->sk), filter.table_id);
 		if (!mrt) {
 			if (rtnl_msg_family(cb->nlh) != RTNL_FAMILY_IPMR)
 				return skb->len;
@@ -2695,7 +2858,7 @@ static int rtm_to_ipmr_mfcc(struct net *net, struct nlmsghdr *nlh,
 			break;
 		}
 	}
-	mrt = ipmr_get_table(net, tblid);
+	mrt = __ipmr_get_table(net, tblid);
 	if (!mrt) {
 		ret = -ENOENT;
 		goto out;
@@ -2791,7 +2954,8 @@ static int ipmr_valid_dumplink(const struct nlmsghdr *nlh,
 {
 	struct ifinfomsg *ifm;
 
-	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ifm))) {
+	ifm = nlmsg_payload(nlh, sizeof(*ifm));
+	if (!ifm) {
 		NL_SET_ERR_MSG(extack, "ipv4: Invalid header for ipmr link dump");
 		return -EINVAL;
 	}
@@ -2801,7 +2965,6 @@ static int ipmr_valid_dumplink(const struct nlmsghdr *nlh,
 		return -EINVAL;
 	}
 
-	ifm = nlmsg_data(nlh);
 	if (ifm->__ifi_pad || ifm->ifi_type || ifm->ifi_flags ||
 	    ifm->ifi_change || ifm->ifi_index) {
 		NL_SET_ERR_MSG(extack, "Invalid values in header for ipmr link dump request");
@@ -2903,13 +3066,15 @@ static void *ipmr_vif_seq_start(struct seq_file *seq, loff_t *pos)
 	struct net *net = seq_file_net(seq);
 	struct mr_table *mrt;
 
-	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
-	if (!mrt)
+	rcu_read_lock();
+	mrt = __ipmr_get_table(net, RT_TABLE_DEFAULT);
+	if (!mrt) {
+		rcu_read_unlock();
 		return ERR_PTR(-ENOENT);
+	}
 
 	iter->mrt = mrt;
 
-	rcu_read_lock();
 	return mr_vif_seq_start(seq, pos);
 }
 
@@ -2982,9 +3147,9 @@ static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
 
 		if (it->cache != &mrt->mfc_unres_queue) {
 			seq_printf(seq, " %8lu %8lu %8lu",
-				   mfc->_c.mfc_un.res.pkt,
-				   mfc->_c.mfc_un.res.bytes,
-				   mfc->_c.mfc_un.res.wrong_if);
+				   atomic_long_read(&mfc->_c.mfc_un.res.pkt),
+				   atomic_long_read(&mfc->_c.mfc_un.res.bytes),
+				   atomic_long_read(&mfc->_c.mfc_un.res.wrong_if));
 			for (n = mfc->_c.mfc_un.res.minvif;
 			     n < mfc->_c.mfc_un.res.maxvif; n++) {
 				if (VIF_EXISTS(mrt, n) &&
@@ -3018,11 +3183,9 @@ static const struct net_protocol pim_protocol = {
 };
 #endif
 
-static unsigned int ipmr_seq_read(struct net *net)
+static unsigned int ipmr_seq_read(const struct net *net)
 {
-	ASSERT_RTNL();
-
-	return net->ipv4.ipmr_seq + ipmr_rules_seq_read(net);
+	return READ_ONCE(net->ipv4.ipmr_seq) + ipmr_rules_seq_read(net);
 }
 
 static int ipmr_dump(struct net *net, struct notifier_block *nb,
@@ -3122,14 +3285,22 @@ static struct pernet_operations ipmr_net_ops = {
 	.exit_batch = ipmr_net_exit_batch,
 };
 
+static const struct rtnl_msg_handler ipmr_rtnl_msg_handlers[] __initconst = {
+	{.protocol = RTNL_FAMILY_IPMR, .msgtype = RTM_GETLINK,
+	 .dumpit = ipmr_rtm_dumplink},
+	{.protocol = RTNL_FAMILY_IPMR, .msgtype = RTM_NEWROUTE,
+	 .doit = ipmr_rtm_route},
+	{.protocol = RTNL_FAMILY_IPMR, .msgtype = RTM_DELROUTE,
+	 .doit = ipmr_rtm_route},
+	{.protocol = RTNL_FAMILY_IPMR, .msgtype = RTM_GETROUTE,
+	 .doit = ipmr_rtm_getroute, .dumpit = ipmr_rtm_dumproute},
+};
+
 int __init ip_mr_init(void)
 {
 	int err;
 
-	mrt_cachep = kmem_cache_create("ip_mrt_cache",
-				       sizeof(struct mfc_cache),
-				       0, SLAB_HWCACHE_ALIGN | SLAB_PANIC,
-				       NULL);
+	mrt_cachep = KMEM_CACHE(mfc_cache, SLAB_HWCACHE_ALIGN | SLAB_PANIC);
 
 	err = register_pernet_subsys(&ipmr_net_ops);
 	if (err)
@@ -3145,15 +3316,8 @@ int __init ip_mr_init(void)
 		goto add_proto_fail;
 	}
 #endif
-	rtnl_register(RTNL_FAMILY_IPMR, RTM_GETROUTE,
-		      ipmr_rtm_getroute, ipmr_rtm_dumproute, 0);
-	rtnl_register(RTNL_FAMILY_IPMR, RTM_NEWROUTE,
-		      ipmr_rtm_route, NULL, 0);
-	rtnl_register(RTNL_FAMILY_IPMR, RTM_DELROUTE,
-		      ipmr_rtm_route, NULL, 0);
-
-	rtnl_register(RTNL_FAMILY_IPMR, RTM_GETLINK,
-		      NULL, ipmr_rtm_dumplink, 0);
+	rtnl_register_many(ipmr_rtnl_msg_handlers);
+
 	return 0;
 
 #ifdef CONFIG_IP_PIMSM_V2