[mirror_ubuntu-hirsute-kernel.git] / net / bridge / br_input.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *	Handle incoming frames
 *	Linux ethernet bridge
 *
 *	Authors:
 *	Lennert Buytenhek		<buytenh@gnu.org>
 */

#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/netfilter_bridge.h>
#ifdef CONFIG_NETFILTER_FAMILY_BRIDGE
#include <net/netfilter/nf_queue.h>
#endif
#include <linux/neighbour.h>
#include <net/arp.h>
#include <net/dsa.h>
#include <linux/export.h>
#include <linux/rculist.h>
#include "br_private.h"
#include "br_private_tunnel.h"

static int
br_netif_receive_skb(struct net *net, struct sock *sk, struct sk_buff *skb)
{
	br_drop_fake_rtable(skb);
	return netif_receive_skb(skb);
}

static int br_pass_frame_up(struct sk_buff *skb)
{
	struct net_device *indev, *brdev = BR_INPUT_SKB_CB(skb)->brdev;
	struct net_bridge *br = netdev_priv(brdev);
	struct net_bridge_vlan_group *vg;

	dev_sw_netstats_rx_add(brdev, skb->len);

	vg = br_vlan_group_rcu(br);
	/* Bridge is just like any other port.  Make sure the
	 * packet is allowed except in promisc modue when someone
	 * may be running packet capture.
	 */
	if (!(brdev->flags & IFF_PROMISC) &&
	    !br_allowed_egress(vg, skb)) {
		kfree_skb(skb);
		return NET_RX_DROP;
	}

	indev = skb->dev;
	skb->dev = brdev;
	skb = br_handle_vlan(br, NULL, vg, skb);
	if (!skb)
		return NET_RX_DROP;
	/* update the multicast stats if the packet is IGMP/MLD */
	br_multicast_count(br, NULL, skb, br_multicast_igmp_type(skb),
			   BR_MCAST_DIR_TX);

	return NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN,
		       dev_net(indev), NULL, skb, indev, NULL,
		       br_netif_receive_skb);
}

/* note: already called with rcu_read_lock */
int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
{
	struct net_bridge_port *p = br_port_get_rcu(skb->dev);
	enum br_pkt_type pkt_type = BR_PKT_UNICAST;
	struct net_bridge_fdb_entry *dst = NULL;
	struct net_bridge_mdb_entry *mdst;
	bool local_rcv, mcast_hit = false;
	struct net_bridge *br;
	u16 vid = 0;
	u8 state;

	if (!p || p->state == BR_STATE_DISABLED)
		goto drop;

	state = p->state;
	if (!br_allowed_ingress(p->br, nbp_vlan_group_rcu(p), skb, &vid,
				&state))
		goto out;

	nbp_switchdev_frame_mark(p, skb);

	/* insert into forwarding database after filtering to avoid spoofing */
	br = p->br;
	if (p->flags & BR_LEARNING)
		br_fdb_update(br, p, eth_hdr(skb)->h_source, vid, 0);

	local_rcv = !!(br->dev->flags & IFF_PROMISC);
	if (is_multicast_ether_addr(eth_hdr(skb)->h_dest)) {
		/* by definition the broadcast is also a multicast address */
		if (is_broadcast_ether_addr(eth_hdr(skb)->h_dest)) {
			pkt_type = BR_PKT_BROADCAST;
			local_rcv = true;
		} else {
			pkt_type = BR_PKT_MULTICAST;
			if (br_multicast_rcv(br, p, skb, vid))
				goto drop;
		}
	}

	if (state == BR_STATE_LEARNING)
		goto drop;

	BR_INPUT_SKB_CB(skb)->brdev = br->dev;
	BR_INPUT_SKB_CB(skb)->src_port_isolated = !!(p->flags & BR_ISOLATED);

	if (IS_ENABLED(CONFIG_INET) &&
	    (skb->protocol == htons(ETH_P_ARP) ||
	     skb->protocol == htons(ETH_P_RARP))) {
		br_do_proxy_suppress_arp(skb, br, vid, p);
	} else if (IS_ENABLED(CONFIG_IPV6) &&
		   skb->protocol == htons(ETH_P_IPV6) &&
		   br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED) &&
		   pskb_may_pull(skb, sizeof(struct ipv6hdr) +
				 sizeof(struct nd_msg)) &&
		   ipv6_hdr(skb)->nexthdr == IPPROTO_ICMPV6) {
			struct nd_msg *msg, _msg;

			msg = br_is_nd_neigh_msg(skb, &_msg);
			if (msg)
				br_do_suppress_nd(skb, br, vid, p, msg);
	}

	switch (pkt_type) {
	case BR_PKT_MULTICAST:
		mdst = br_mdb_get(br, skb, vid);
		if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) &&
		    br_multicast_querier_exists(br, eth_hdr(skb), mdst)) {
			if ((mdst && mdst->host_joined) ||
			    br_multicast_is_router(br)) {
				local_rcv = true;
				br->dev->stats.multicast++;
			}
			mcast_hit = true;
		} else {
			local_rcv = true;
			br->dev->stats.multicast++;
		}
		break;
	case BR_PKT_UNICAST:
		dst = br_fdb_find_rcu(br, eth_hdr(skb)->h_dest, vid);
	default:
		break;
	}

	if (dst) {
		unsigned long now = jiffies;

		if (test_bit(BR_FDB_LOCAL, &dst->flags))
			return br_pass_frame_up(skb);

		if (now != dst->used)
			dst->used = now;
		br_forward(dst->dst, skb, local_rcv, false);
	} else {
		if (!mcast_hit)
			br_flood(br, skb, pkt_type, local_rcv, false);
		else
			br_multicast_flood(mdst, skb, local_rcv, false);
	}

	if (local_rcv)
		return br_pass_frame_up(skb);

out:
	return 0;
drop:
	kfree_skb(skb);
	goto out;
}
EXPORT_SYMBOL_GPL(br_handle_frame_finish);

static void __br_handle_local_finish(struct sk_buff *skb)
{
	struct net_bridge_port *p = br_port_get_rcu(skb->dev);
	u16 vid = 0;

	/* check if vlan is allowed, to avoid spoofing */
	if ((p->flags & BR_LEARNING) &&
	    nbp_state_should_learn(p) &&
	    !br_opt_get(p->br, BROPT_NO_LL_LEARN) &&
	    br_should_learn(p, skb, &vid))
		br_fdb_update(p->br, p, eth_hdr(skb)->h_source, vid, 0);
}

/* note: already called with rcu_read_lock */
static int br_handle_local_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
{
	__br_handle_local_finish(skb);

	/* return 1 to signal the okfn() was called so it's ok to use the skb */
	return 1;
}

static int nf_hook_bridge_pre(struct sk_buff *skb, struct sk_buff **pskb)
{
#ifdef CONFIG_NETFILTER_FAMILY_BRIDGE
	struct nf_hook_entries *e = NULL;
	struct nf_hook_state state;
	unsigned int verdict, i;
	struct net *net;
	int ret;

	net = dev_net(skb->dev);
#ifdef HAVE_JUMP_LABEL
	if (!static_key_false(&nf_hooks_needed[NFPROTO_BRIDGE][NF_BR_PRE_ROUTING]))
		goto frame_finish;
#endif

	e = rcu_dereference(net->nf.hooks_bridge[NF_BR_PRE_ROUTING]);
	if (!e)
		goto frame_finish;

	nf_hook_state_init(&state, NF_BR_PRE_ROUTING,
			   NFPROTO_BRIDGE, skb->dev, NULL, NULL,
			   net, br_handle_frame_finish);

	for (i = 0; i < e->num_hook_entries; i++) {
		verdict = nf_hook_entry_hookfn(&e->hooks[i], skb, &state);
		switch (verdict & NF_VERDICT_MASK) {
		case NF_ACCEPT:
			if (BR_INPUT_SKB_CB(skb)->br_netfilter_broute) {
				*pskb = skb;
				return RX_HANDLER_PASS;
			}
			break;
		case NF_DROP:
			kfree_skb(skb);
			return RX_HANDLER_CONSUMED;
		case NF_QUEUE:
			ret = nf_queue(skb, &state, i, verdict);
			if (ret == 1)
				continue;
			return RX_HANDLER_CONSUMED;
		default: /* STOLEN */
			return RX_HANDLER_CONSUMED;
		}
	}
frame_finish:
	net = dev_net(skb->dev);
	br_handle_frame_finish(net, NULL, skb);
#else
	br_handle_frame_finish(dev_net(skb->dev), NULL, skb);
#endif
	return RX_HANDLER_CONSUMED;
}

/* Return 0 if the frame was not processed otherwise 1
 * note: already called with rcu_read_lock
 */
static int br_process_frame_type(struct net_bridge_port *p,
				 struct sk_buff *skb)
{
	struct br_frame_type *tmp;

	hlist_for_each_entry_rcu(tmp, &p->br->frame_type_list, list)
		if (unlikely(tmp->type == skb->protocol))
			return tmp->frame_handler(p, skb);

	return 0;
}

/*
 * Return NULL if skb is handled
 * note: already called with rcu_read_lock
 */
static rx_handler_result_t br_handle_frame(struct sk_buff **pskb)
{
	struct net_bridge_port *p;
	struct sk_buff *skb = *pskb;
	const unsigned char *dest = eth_hdr(skb)->h_dest;

	if (unlikely(skb->pkt_type == PACKET_LOOPBACK))
		return RX_HANDLER_PASS;

	if (!is_valid_ether_addr(eth_hdr(skb)->h_source))
		goto drop;

	skb = skb_share_check(skb, GFP_ATOMIC);
	if (!skb)
		return RX_HANDLER_CONSUMED;

	memset(skb->cb, 0, sizeof(struct br_input_skb_cb));

	p = br_port_get_rcu(skb->dev);
	if (p->flags & BR_VLAN_TUNNEL) {
		if (br_handle_ingress_vlan_tunnel(skb, p,
						  nbp_vlan_group_rcu(p)))
			goto drop;
	}

	if (unlikely(is_link_local_ether_addr(dest))) {
		u16 fwd_mask = p->br->group_fwd_mask_required;

		/*
		 * See IEEE 802.1D Table 7-10 Reserved addresses
		 *
		 * Assignment		 		Value
		 * Bridge Group Address		01-80-C2-00-00-00
		 * (MAC Control) 802.3		01-80-C2-00-00-01
		 * (Link Aggregation) 802.3	01-80-C2-00-00-02
		 * 802.1X PAE address		01-80-C2-00-00-03
		 *
		 * 802.1AB LLDP 		01-80-C2-00-00-0E
		 *
		 * Others reserved for future standardization
		 */
		fwd_mask |= p->group_fwd_mask;
		switch (dest[5]) {
		case 0x00:	/* Bridge Group Address */
			/* If STP is turned off,
			   then must forward to keep loop detection */
			if (p->br->stp_enabled == BR_NO_STP ||
			    fwd_mask & (1u << dest[5]))
				goto forward;
			*pskb = skb;
			__br_handle_local_finish(skb);
			return RX_HANDLER_PASS;

		case 0x01:	/* IEEE MAC (Pause) */
			goto drop;

		case 0x0E:	/* 802.1AB LLDP */
			fwd_mask |= p->br->group_fwd_mask;
			if (fwd_mask & (1u << dest[5]))
				goto forward;
			*pskb = skb;
			__br_handle_local_finish(skb);
			return RX_HANDLER_PASS;

		default:
			/* Allow selective forwarding for most other protocols */
			fwd_mask |= p->br->group_fwd_mask;
			if (fwd_mask & (1u << dest[5]))
				goto forward;
		}

		/* The else clause should be hit when nf_hook():
		 *   - returns < 0 (drop/error)
		 *   - returns = 0 (stolen/nf_queue)
		 * Thus return 1 from the okfn() to signal the skb is ok to pass
		 */
		if (NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN,
			    dev_net(skb->dev), NULL, skb, skb->dev, NULL,
			    br_handle_local_finish) == 1) {
			return RX_HANDLER_PASS;
		} else {
			return RX_HANDLER_CONSUMED;
		}
	}

	if (unlikely(br_process_frame_type(p, skb)))
		return RX_HANDLER_PASS;

forward:
	switch (p->state) {
	case BR_STATE_FORWARDING:
	case BR_STATE_LEARNING:
		if (ether_addr_equal(p->br->dev->dev_addr, dest))
			skb->pkt_type = PACKET_HOST;

		return nf_hook_bridge_pre(skb, pskb);
	default:
drop:
		kfree_skb(skb);
	}
	return RX_HANDLER_CONSUMED;
}

/* This function has no purpose other than to appease the br_port_get_rcu/rtnl
 * helpers which identify bridged ports according to the rx_handler installed
 * on them (so there _needs_ to be a bridge rx_handler even if we don't need it
 * to do anything useful). This bridge won't support traffic to/from the stack,
 * but only hardware bridging. So return RX_HANDLER_PASS so we don't steal
 * frames from the ETH_P_XDSA packet_type handler.
 */
static rx_handler_result_t br_handle_frame_dummy(struct sk_buff **pskb)
{
	return RX_HANDLER_PASS;
}

rx_handler_func_t *br_get_rx_handler(const struct net_device *dev)
{
	if (netdev_uses_dsa(dev))
		return br_handle_frame_dummy;

	return br_handle_frame;
}

void br_add_frame(struct net_bridge *br, struct br_frame_type *ft)
{
	hlist_add_head_rcu(&ft->list, &br->frame_type_list);
}

void br_del_frame(struct net_bridge *br, struct br_frame_type *ft)
{
	struct br_frame_type *tmp;

	hlist_for_each_entry(tmp, &br->frame_type_list, list)
		if (ft == tmp) {
			hlist_del_rcu(&ft->list);
			return;
		}
}
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
1da177e4 LT	2	/*
	3	* Handle incoming frames
	4	* Linux ethernet bridge
	5	*
	6	* Authors:
	7	* Lennert Buytenhek <buytenh@gnu.org>
1da177e4 LT	8	*/
1da177e4 LT	9
5a0e3ad6	10	#include <linux/slab.h>
1da177e4 LT	11	#include <linux/kernel.h>
	12	#include <linux/netdevice.h>
	13	#include <linux/etherdevice.h>
	14	#include <linux/netfilter_bridge.h>
dc2f4189	15	#ifdef CONFIG_NETFILTER_FAMILY_BRIDGE
971502d7	16	#include <net/netfilter/nf_queue.h>
dc2f4189	17	#endif
95850116 KP	18	#include <linux/neighbour.h>
95850116 KP	19	#include <net/arp.h>
9eb8eff0	20	#include <net/dsa.h>
bc3b2d7f	21	#include <linux/export.h>
a37b85c9	22	#include <linux/rculist.h>
1da177e4	23	#include "br_private.h"
11538d03	24	#include "br_private_tunnel.h"
1da177e4	25
0c4b51f0 EB	26	static int
0c4b51f0 EB	27	br_netif_receive_skb(struct net net, struct sock sk, struct sk_buff *skb)
04eb4489	28	{
a13b2082	29	br_drop_fake_rtable(skb);
04eb4489 EB	30	return netif_receive_skb(skb);
	31	}
	32
68b7c895	33	static int br_pass_frame_up(struct sk_buff *skb)
1da177e4	34	{
68b7c895	35	struct net_device indev, brdev = BR_INPUT_SKB_CB(skb)->brdev;
14bb4789	36	struct net_bridge *br = netdev_priv(brdev);
2594e906	37	struct net_bridge_vlan_group *vg;
1da177e4	38
7609ecb2	39	dev_sw_netstats_rx_add(brdev, skb->len);
1da177e4	40
907b1e6e	41	vg = br_vlan_group_rcu(br);
85f46c6b VY	42	/* Bridge is just like any other port. Make sure the
	43	* packet is allowed except in promisc modue when someone
	44	* may be running packet capture.
	45	*/
	46	if (!(brdev->flags & IFF_PROMISC) &&
2594e906	47	!br_allowed_egress(vg, skb)) {
85f46c6b VY	48	kfree_skb(skb);
	49	return NET_RX_DROP;
	50	}
	51
1da177e4	52	indev = skb->dev;
a339f1c8	53	skb->dev = brdev;
11538d03	54	skb = br_handle_vlan(br, NULL, vg, skb);
fc92f745 VY	55	if (!skb)
fc92f745 VY	56	return NET_RX_DROP;
1080ab95	57	/* update the multicast stats if the packet is IGMP/MLD */
a65056ec	58	br_multicast_count(br, NULL, skb, br_multicast_igmp_type(skb),
1080ab95	59	BR_MCAST_DIR_TX);
1da177e4	60
29a26a56 EB	61	return NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN,
29a26a56 EB	62	dev_net(indev), NULL, skb, indev, NULL,
04eb4489	63	br_netif_receive_skb);
1da177e4 LT	64	}
1da177e4 LT	65
eeaf61d8	66	/* note: already called with rcu_read_lock */
0c4b51f0	67	int br_handle_frame_finish(struct net net, struct sock sk, struct sk_buff *skb)
1da177e4	68	{
f350a0a8	69	struct net_bridge_port *p = br_port_get_rcu(skb->dev);
8addd5e7	70	enum br_pkt_type pkt_type = BR_PKT_UNICAST;
46c0772d	71	struct net_bridge_fdb_entry *dst = NULL;
c4fcb78c	72	struct net_bridge_mdb_entry *mdst;
8addd5e7	73	bool local_rcv, mcast_hit = false;
46c0772d	74	struct net_bridge *br;
78851988	75	u16 vid = 0;
a580c76d	76	u8 state;
1da177e4	77
b3f1be4b SH	78	if (!p \|\| p->state == BR_STATE_DISABLED)
	79	goto drop;
	80
a580c76d NA	81	state = p->state;
	82	if (!br_allowed_ingress(p->br, nbp_vlan_group_rcu(p), skb, &vid,
	83	&state))
eb707618	84	goto out;
a37b85c9	85
6bc506b4 IS	86	nbp_switchdev_frame_mark(p, skb);
6bc506b4 IS	87
85967bb4	88	/* insert into forwarding database after filtering to avoid spoofing */
b3f1be4b	89	br = p->br;
9ba18891	90	if (p->flags & BR_LEARNING)
be0c5677	91	br_fdb_update(br, p, eth_hdr(skb)->h_source, vid, 0);
85967bb4	92
8addd5e7	93	local_rcv = !!(br->dev->flags & IFF_PROMISC);
3d26eb8a	94	if (is_multicast_ether_addr(eth_hdr(skb)->h_dest)) {
8addd5e7	95	/* by definition the broadcast is also a multicast address */
3d26eb8a	96	if (is_broadcast_ether_addr(eth_hdr(skb)->h_dest)) {
8addd5e7 NA	97	pkt_type = BR_PKT_BROADCAST;
	98	local_rcv = true;
	99	} else {
	100	pkt_type = BR_PKT_MULTICAST;
	101	if (br_multicast_rcv(br, p, skb, vid))
	102	goto drop;
	103	}
	104	}
c4fcb78c	105
a580c76d	106	if (state == BR_STATE_LEARNING)
b3f1be4b	107	goto drop;
0e5eabac	108
68b7c895	109	BR_INPUT_SKB_CB(skb)->brdev = br->dev;
7d850abd	110	BR_INPUT_SKB_CB(skb)->src_port_isolated = !!(p->flags & BR_ISOLATED);
68b7c895	111
057658cb RP	112	if (IS_ENABLED(CONFIG_INET) &&
	113	(skb->protocol == htons(ETH_P_ARP) \|\|
	114	skb->protocol == htons(ETH_P_RARP))) {
	115	br_do_proxy_suppress_arp(skb, br, vid, p);
ed842fae RP	116	} else if (IS_ENABLED(CONFIG_IPV6) &&
ed842fae RP	117	skb->protocol == htons(ETH_P_IPV6) &&
c69c2cd4	118	br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED) &&
ed842fae RP	119	pskb_may_pull(skb, sizeof(struct ipv6hdr) +
	120	sizeof(struct nd_msg)) &&
	121	ipv6_hdr(skb)->nexthdr == IPPROTO_ICMPV6) {
	122	struct nd_msg *msg, _msg;
	123
	124	msg = br_is_nd_neigh_msg(skb, &_msg);
	125	if (msg)
	126	br_do_suppress_nd(skb, br, vid, p, msg);
057658cb	127	}
95850116	128
8addd5e7 NA	129	switch (pkt_type) {
8addd5e7 NA	130	case BR_PKT_MULTICAST:
fbca58a2	131	mdst = br_mdb_get(br, skb, vid);
b00589af	132	if ((mdst \|\| BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) &&
955062b0	133	br_multicast_querier_exists(br, eth_hdr(skb), mdst)) {
ff0fd34e	134	if ((mdst && mdst->host_joined) \|\|
e151aab9	135	br_multicast_is_router(br)) {
b35c5f63	136	local_rcv = true;
e151aab9 NA	137	br->dev->stats.multicast++;
	138	}
	139	mcast_hit = true;
46c0772d	140	} else {
b35c5f63	141	local_rcv = true;
e151aab9	142	br->dev->stats.multicast++;
46c0772d	143	}
8addd5e7 NA	144	break;
8addd5e7 NA	145	case BR_PKT_UNICAST:
3d26eb8a	146	dst = br_fdb_find_rcu(br, eth_hdr(skb)->h_dest, vid);
8addd5e7 NA	147	default:
8addd5e7 NA	148	break;
1da177e4 LT	149	}
1da177e4 LT	150
e151aab9	151	if (dst) {
ca6d4480	152	unsigned long now = jiffies;
ca6d4480	153
6869c3b0	154	if (test_bit(BR_FDB_LOCAL, &dst->flags))
8addd5e7 NA	155	return br_pass_frame_up(skb);
8addd5e7 NA	156
ca6d4480	157	if (now != dst->used)
ca6d4480	158	dst->used = now;
37b090e6	159	br_forward(dst->dst, skb, local_rcv, false);
e151aab9 NA	160	} else {
e151aab9 NA	161	if (!mcast_hit)
8addd5e7	162	br_flood(br, skb, pkt_type, local_rcv, false);
e151aab9	163	else
37b090e6	164	br_multicast_flood(mdst, skb, local_rcv, false);
e081e1e3	165	}
1da177e4	166
b35c5f63 NA	167	if (local_rcv)
b35c5f63 NA	168	return br_pass_frame_up(skb);
87557c18	169
1da177e4 LT	170	out:
1da177e4 LT	171	return 0;
b3f1be4b SH	172	drop:
	173	kfree_skb(skb);
	174	goto out;
1da177e4	175	}
34666d46	176	EXPORT_SYMBOL_GPL(br_handle_frame_finish);
1da177e4	177
56fae404	178	static void __br_handle_local_finish(struct sk_buff *skb)
cf0f02d0	179	{
f350a0a8	180	struct net_bridge_port *p = br_port_get_rcu(skb->dev);
2ba071ec	181	u16 vid = 0;
cf0f02d0	182
e0d7968a	183	/* check if vlan is allowed, to avoid spoofing */
70e4272b	184	if ((p->flags & BR_LEARNING) &&
5d1fcaf3	185	nbp_state_should_learn(p) &&
70e4272b NA	186	!br_opt_get(p->br, BROPT_NO_LL_LEARN) &&
70e4272b NA	187	br_should_learn(p, skb, &vid))
be0c5677	188	br_fdb_update(p->br, p, eth_hdr(skb)->h_source, vid, 0);
56fae404 IS	189	}
	190
	191	/* note: already called with rcu_read_lock */
	192	static int br_handle_local_finish(struct net net, struct sock sk, struct sk_buff *skb)
	193	{
56fae404	194	__br_handle_local_finish(skb);
8626c56c	195
3b2e2904 NA	196	/* return 1 to signal the okfn() was called so it's ok to use the skb */
3b2e2904 NA	197	return 1;
cf0f02d0 SH	198	}
cf0f02d0 SH	199
971502d7 FW	200	static int nf_hook_bridge_pre(struct sk_buff skb, struct sk_buff *pskb)
	201	{
	202	#ifdef CONFIG_NETFILTER_FAMILY_BRIDGE
	203	struct nf_hook_entries *e = NULL;
	204	struct nf_hook_state state;
	205	unsigned int verdict, i;
	206	struct net *net;
	207	int ret;
	208
	209	net = dev_net(skb->dev);
	210	#ifdef HAVE_JUMP_LABEL
	211	if (!static_key_false(&nf_hooks_needed[NFPROTO_BRIDGE][NF_BR_PRE_ROUTING]))
	212	goto frame_finish;
	213	#endif
	214
	215	e = rcu_dereference(net->nf.hooks_bridge[NF_BR_PRE_ROUTING]);
	216	if (!e)
	217	goto frame_finish;
	218
	219	nf_hook_state_init(&state, NF_BR_PRE_ROUTING,
	220	NFPROTO_BRIDGE, skb->dev, NULL, NULL,
	221	net, br_handle_frame_finish);
	222
	223	for (i = 0; i < e->num_hook_entries; i++) {
	224	verdict = nf_hook_entry_hookfn(&e->hooks[i], skb, &state);
	225	switch (verdict & NF_VERDICT_MASK) {
	226	case NF_ACCEPT:
223fd0ad FW	227	if (BR_INPUT_SKB_CB(skb)->br_netfilter_broute) {
	228	*pskb = skb;
	229	return RX_HANDLER_PASS;
	230	}
971502d7 FW	231	break;
	232	case NF_DROP:
	233	kfree_skb(skb);
	234	return RX_HANDLER_CONSUMED;
	235	case NF_QUEUE:
0d9cb300	236	ret = nf_queue(skb, &state, i, verdict);
971502d7 FW	237	if (ret == 1)
	238	continue;
	239	return RX_HANDLER_CONSUMED;
	240	default: /* STOLEN */
	241	return RX_HANDLER_CONSUMED;
	242	}
	243	}
	244	frame_finish:
	245	net = dev_net(skb->dev);
	246	br_handle_frame_finish(net, NULL, skb);
	247	#else
	248	br_handle_frame_finish(dev_net(skb->dev), NULL, skb);
	249	#endif
	250	return RX_HANDLER_CONSUMED;
	251	}
	252
90c628dd HB	253	/* Return 0 if the frame was not processed otherwise 1
	254	* note: already called with rcu_read_lock
	255	*/
	256	static int br_process_frame_type(struct net_bridge_port *p,
	257	struct sk_buff *skb)
	258	{
	259	struct br_frame_type *tmp;
	260
	261	hlist_for_each_entry_rcu(tmp, &p->br->frame_type_list, list)
	262	if (unlikely(tmp->type == skb->protocol))
	263	return tmp->frame_handler(p, skb);
	264
	265	return 0;
	266	}
	267
1da177e4	268	/*
6229e362	269	* Return NULL if skb is handled
eeaf61d8	270	* note: already called with rcu_read_lock
1da177e4	271	*/
9eb8eff0	272	static rx_handler_result_t br_handle_frame(struct sk_buff **pskb)
1da177e4	273	{
ab95bfe0	274	struct net_bridge_port *p;
8a4eb573	275	struct sk_buff skb = pskb;
1da177e4 LT	276	const unsigned char *dest = eth_hdr(skb)->h_dest;
1da177e4 LT	277
c2368e79	278	if (unlikely(skb->pkt_type == PACKET_LOOPBACK))
8a4eb573	279	return RX_HANDLER_PASS;
ab95bfe0	280
1da177e4	281	if (!is_valid_ether_addr(eth_hdr(skb)->h_source))
467aea0d	282	goto drop;
1da177e4	283
7b995651 HX	284	skb = skb_share_check(skb, GFP_ATOMIC);
7b995651 HX	285	if (!skb)
8a4eb573	286	return RX_HANDLER_CONSUMED;
7b995651	287
f12064d1 FW	288	memset(skb->cb, 0, sizeof(struct br_input_skb_cb));
f12064d1 FW	289
f350a0a8	290	p = br_port_get_rcu(skb->dev);
11538d03 RP	291	if (p->flags & BR_VLAN_TUNNEL) {
	292	if (br_handle_ingress_vlan_tunnel(skb, p,
	293	nbp_vlan_group_rcu(p)))
	294	goto drop;
	295	}
ab95bfe0	296
46acc460	297	if (unlikely(is_link_local_ether_addr(dest))) {
f2808d22 TM	298	u16 fwd_mask = p->br->group_fwd_mask_required;
f2808d22 TM	299
515853cc	300	/*
	301	* See IEEE 802.1D Table 7-10 Reserved addresses
	302	*
	303	* Assignment Value
	304	* Bridge Group Address 01-80-C2-00-00-00
	305	* (MAC Control) 802.3 01-80-C2-00-00-01
	306	* (Link Aggregation) 802.3 01-80-C2-00-00-02
	307	* 802.1X PAE address 01-80-C2-00-00-03
	308	*
	309	* 802.1AB LLDP 01-80-C2-00-00-0E
	310	*
	311	* Others reserved for future standardization
	312	*/
5af48b59	313	fwd_mask \|= p->group_fwd_mask;
515853cc	314	switch (dest[5]) {
	315	case 0x00: /* Bridge Group Address */
	316	/* If STP is turned off,
	317	then must forward to keep loop detection */
f2808d22 TM	318	if (p->br->stp_enabled == BR_NO_STP \|\|
f2808d22 TM	319	fwd_mask & (1u << dest[5]))
515853cc	320	goto forward;
56fae404 IS	321	*pskb = skb;
	322	__br_handle_local_finish(skb);
	323	return RX_HANDLER_PASS;
515853cc	324
515853cc	325	case 0x01: /* IEEE MAC (Pause) */
2111f8b9 SH	326	goto drop;
2111f8b9 SH	327
baedbe55 IS	328	case 0x0E: /* 802.1AB LLDP */
	329	fwd_mask \|= p->br->group_fwd_mask;
	330	if (fwd_mask & (1u << dest[5]))
	331	goto forward;
	332	*pskb = skb;
	333	__br_handle_local_finish(skb);
	334	return RX_HANDLER_PASS;
	335
515853cc	336	default:
515853cc	337	/* Allow selective forwarding for most other protocols */
f2808d22 TM	338	fwd_mask \|= p->br->group_fwd_mask;
f2808d22 TM	339	if (fwd_mask & (1u << dest[5]))
515853cc	340	goto forward;
515853cc	341	}
a598f6ae	342
3b2e2904 NA	343	/* The else clause should be hit when nf_hook():
	344	* - returns < 0 (drop/error)
	345	* - returns = 0 (stolen/nf_queue)
	346	* Thus return 1 from the okfn() to signal the skb is ok to pass
	347	*/
	348	if (NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN,
	349	dev_net(skb->dev), NULL, skb, skb->dev, NULL,
	350	br_handle_local_finish) == 1) {
	351	return RX_HANDLER_PASS;
	352	} else {
	353	return RX_HANDLER_CONSUMED;
	354	}
2111f8b9	355	}
1da177e4	356
90c628dd	357	if (unlikely(br_process_frame_type(p, skb)))
65369933 HV	358	return RX_HANDLER_PASS;
65369933 HV	359
a598f6ae	360	forward:
467aea0d SH	361	switch (p->state) {
467aea0d SH	362	case BR_STATE_FORWARDING:
467aea0d	363	case BR_STATE_LEARNING:
9a7b6ef9	364	if (ether_addr_equal(p->br->dev->dev_addr, dest))
1da177e4 LT	365	skb->pkt_type = PACKET_HOST;
1da177e4 LT	366
971502d7	367	return nf_hook_bridge_pre(skb, pskb);
467aea0d SH	368	default:
	369	drop:
	370	kfree_skb(skb);
1da177e4	371	}
8a4eb573	372	return RX_HANDLER_CONSUMED;
1da177e4	373	}
9eb8eff0 VO	374
	375	/* This function has no purpose other than to appease the br_port_get_rcu/rtnl
	376	* helpers which identify bridged ports according to the rx_handler installed
	377	* on them (so there _needs_ to be a bridge rx_handler even if we don't need it
	378	* to do anything useful). This bridge won't support traffic to/from the stack,
	379	* but only hardware bridging. So return RX_HANDLER_PASS so we don't steal
	380	* frames from the ETH_P_XDSA packet_type handler.
	381	*/
	382	static rx_handler_result_t br_handle_frame_dummy(struct sk_buff **pskb)
	383	{
	384	return RX_HANDLER_PASS;
	385	}
	386
	387	rx_handler_func_t br_get_rx_handler(const struct net_device dev)
	388	{
	389	if (netdev_uses_dsa(dev))
	390	return br_handle_frame_dummy;
	391
	392	return br_handle_frame;
	393	}
90c628dd HB	394
	395	void br_add_frame(struct net_bridge br, struct br_frame_type ft)
	396	{
	397	hlist_add_head_rcu(&ft->list, &br->frame_type_list);
	398	}
	399
	400	void br_del_frame(struct net_bridge br, struct br_frame_type ft)
	401	{
	402	struct br_frame_type *tmp;
	403
	404	hlist_for_each_entry(tmp, &br->frame_type_list, list)
	405	if (ft == tmp) {
	406	hlist_del_rcu(&ft->list);
	407	return;
	408	}
	409	}