net: bridge: multicast: add EHT host handling functions

Add functions to create, destroy and lookup an EHT host. These are
per-host entries contained in the eht_host_tree in net_bridge_port_group
which are used to store a list of all sources (S,G) entries joined for that
group by each host, the host's current filter mode and total number of
joined entries.
No functional changes yet, these would be used in later patches.

Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/bridge/Makefile

@@ -18,7 +18,7 @@ br_netfilter-y := br_netfilter_hooks.o
 br_netfilter-$(subst m,y,$(CONFIG_IPV6)) += br_netfilter_ipv6.o
 obj-$(CONFIG_BRIDGE_NETFILTER) += br_netfilter.o
 
-bridge-$(CONFIG_BRIDGE_IGMP_SNOOPING) += br_multicast.o br_mdb.o
+bridge-$(CONFIG_BRIDGE_IGMP_SNOOPING) += br_multicast.o br_mdb.o br_multicast_eht.o
 
 bridge-$(CONFIG_BRIDGE_VLAN_FILTERING) += br_vlan.o br_vlan_tunnel.o br_vlan_options.o
 

net/bridge/br_multicast.c

@@ -1173,6 +1173,7 @@ struct net_bridge_port_group *br_multicast_new_port_group(
 	p->flags = flags;
 	p->filter_mode = filter_mode;
 	p->rt_protocol = rt_protocol;
+	p->eht_host_tree = RB_ROOT;
 	p->mcast_gc.destroy = br_multicast_destroy_port_group;
 	INIT_HLIST_HEAD(&p->src_list);
 

net/bridge/br_multicast_eht.c

@@ -0,0 +1,115 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+// Copyright (c) 2020, Nikolay Aleksandrov <nikolay@nvidia.com>
+#include <linux/err.h>
+#include <linux/export.h>
+#include <linux/if_ether.h>
+#include <linux/igmp.h>
+#include <linux/in.h>
+#include <linux/jhash.h>
+#include <linux/kernel.h>
+#include <linux/log2.h>
+#include <linux/netdevice.h>
+#include <linux/netfilter_bridge.h>
+#include <linux/random.h>
+#include <linux/rculist.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <linux/timer.h>
+#include <linux/inetdevice.h>
+#include <linux/mroute.h>
+#include <net/ip.h>
+#include <net/switchdev.h>
+#if IS_ENABLED(CONFIG_IPV6)
+#include <linux/icmpv6.h>
+#include <net/ipv6.h>
+#include <net/mld.h>
+#include <net/ip6_checksum.h>
+#include <net/addrconf.h>
+#endif
+
+#include "br_private.h"
+#include "br_private_mcast_eht.h"
+
+static struct net_bridge_group_eht_host *
+br_multicast_eht_host_lookup(struct net_bridge_port_group *pg,
+			     union net_bridge_eht_addr *h_addr)
+{
+	struct rb_node *node = pg->eht_host_tree.rb_node;
+
+	while (node) {
+		struct net_bridge_group_eht_host *this;
+		int result;
+
+		this = rb_entry(node, struct net_bridge_group_eht_host,
+				rb_node);
+		result = memcmp(h_addr, &this->h_addr, sizeof(*h_addr));
+		if (result < 0)
+			node = node->rb_left;
+		else if (result > 0)
+			node = node->rb_right;
+		else
+			return this;
+	}
+
+	return NULL;
+}
+
+static int br_multicast_eht_host_filter_mode(struct net_bridge_port_group *pg,
+					     union net_bridge_eht_addr *h_addr)
+{
+	struct net_bridge_group_eht_host *eht_host;
+
+	eht_host = br_multicast_eht_host_lookup(pg, h_addr);
+	if (!eht_host)
+		return MCAST_INCLUDE;
+
+	return eht_host->filter_mode;
+}
+
+static void __eht_destroy_host(struct net_bridge_group_eht_host *eht_host)
+{
+	WARN_ON(!hlist_empty(&eht_host->set_entries));
+
+	rb_erase(&eht_host->rb_node, &eht_host->pg->eht_host_tree);
+	RB_CLEAR_NODE(&eht_host->rb_node);
+	kfree(eht_host);
+}
+
+static struct net_bridge_group_eht_host *
+__eht_lookup_create_host(struct net_bridge_port_group *pg,
+			 union net_bridge_eht_addr *h_addr,
+			 unsigned char filter_mode)
+{
+	struct rb_node **link = &pg->eht_host_tree.rb_node, *parent = NULL;
+	struct net_bridge_group_eht_host *eht_host;
+
+	while (*link) {
+		struct net_bridge_group_eht_host *this;
+		int result;
+
+		this = rb_entry(*link, struct net_bridge_group_eht_host,
+				rb_node);
+		result = memcmp(h_addr, &this->h_addr, sizeof(*h_addr));
+		parent = *link;
+		if (result < 0)
+			link = &((*link)->rb_left);
+		else if (result > 0)
+			link = &((*link)->rb_right);
+		else
+			return this;
+	}
+
+	eht_host = kzalloc(sizeof(*eht_host), GFP_ATOMIC);
+	if (!eht_host)
+		return NULL;
+
+	memcpy(&eht_host->h_addr, h_addr, sizeof(*h_addr));
+	INIT_HLIST_HEAD(&eht_host->set_entries);
+	eht_host->pg = pg;
+	eht_host->filter_mode = filter_mode;
+
+	rb_link_node(&eht_host->rb_node, parent, link);
+	rb_insert_color(&eht_host->rb_node, &pg->eht_host_tree);
+
+	return eht_host;
+}