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v6.8
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 *	Handle incoming frames
  4 *	Linux ethernet bridge
  5 *
  6 *	Authors:
  7 *	Lennert Buytenhek		<buytenh@gnu.org>
 
 
 
 
 
  8 */
  9
 10#include <linux/slab.h>
 11#include <linux/kernel.h>
 12#include <linux/netdevice.h>
 13#include <linux/etherdevice.h>
 14#include <linux/netfilter_bridge.h>
 15#ifdef CONFIG_NETFILTER_FAMILY_BRIDGE
 16#include <net/netfilter/nf_queue.h>
 17#endif
 18#include <linux/neighbour.h>
 19#include <net/arp.h>
 20#include <net/dsa.h>
 21#include <linux/export.h>
 22#include <linux/rculist.h>
 23#include "br_private.h"
 24#include "br_private_tunnel.h"
 25
 26static int
 27br_netif_receive_skb(struct net *net, struct sock *sk, struct sk_buff *skb)
 28{
 29	br_drop_fake_rtable(skb);
 30	return netif_receive_skb(skb);
 31}
 32
 33static int br_pass_frame_up(struct sk_buff *skb)
 34{
 35	struct net_device *indev, *brdev = BR_INPUT_SKB_CB(skb)->brdev;
 36	struct net_bridge *br = netdev_priv(brdev);
 37	struct net_bridge_vlan_group *vg;
 38
 39	dev_sw_netstats_rx_add(brdev, skb->len);
 40
 41	vg = br_vlan_group_rcu(br);
 42
 43	/* Reset the offload_fwd_mark because there could be a stacked
 44	 * bridge above, and it should not think this bridge it doing
 45	 * that bridge's work forwarding out its ports.
 46	 */
 47	br_switchdev_frame_unmark(skb);
 48
 49	/* Bridge is just like any other port.  Make sure the
 50	 * packet is allowed except in promisc mode when someone
 51	 * may be running packet capture.
 52	 */
 53	if (!(brdev->flags & IFF_PROMISC) &&
 54	    !br_allowed_egress(vg, skb)) {
 55		kfree_skb(skb);
 56		return NET_RX_DROP;
 57	}
 58
 59	indev = skb->dev;
 60	skb->dev = brdev;
 61	skb = br_handle_vlan(br, NULL, vg, skb);
 62	if (!skb)
 63		return NET_RX_DROP;
 64	/* update the multicast stats if the packet is IGMP/MLD */
 65	br_multicast_count(br, NULL, skb, br_multicast_igmp_type(skb),
 66			   BR_MCAST_DIR_TX);
 67
 68	return NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN,
 69		       dev_net(indev), NULL, skb, indev, NULL,
 70		       br_netif_receive_skb);
 71}
 72
 73/* note: already called with rcu_read_lock */
 74int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
 75{
 
 76	struct net_bridge_port *p = br_port_get_rcu(skb->dev);
 77	enum br_pkt_type pkt_type = BR_PKT_UNICAST;
 78	struct net_bridge_fdb_entry *dst = NULL;
 79	struct net_bridge_mcast_port *pmctx;
 80	struct net_bridge_mdb_entry *mdst;
 81	bool local_rcv, mcast_hit = false;
 82	struct net_bridge_mcast *brmctx;
 83	struct net_bridge_vlan *vlan;
 84	struct net_bridge *br;
 85	u16 vid = 0;
 86	u8 state;
 
 87
 88	if (!p)
 89		goto drop;
 90
 91	br = p->br;
 92
 93	if (br_mst_is_enabled(br)) {
 94		state = BR_STATE_FORWARDING;
 95	} else {
 96		if (p->state == BR_STATE_DISABLED)
 97			goto drop;
 98
 99		state = p->state;
100	}
101
102	brmctx = &p->br->multicast_ctx;
103	pmctx = &p->multicast_ctx;
104	if (!br_allowed_ingress(p->br, nbp_vlan_group_rcu(p), skb, &vid,
105				&state, &vlan))
106		goto out;
107
108	if (p->flags & BR_PORT_LOCKED) {
109		struct net_bridge_fdb_entry *fdb_src =
110			br_fdb_find_rcu(br, eth_hdr(skb)->h_source, vid);
111
112		if (!fdb_src) {
113			/* FDB miss. Create locked FDB entry if MAB is enabled
114			 * and drop the packet.
115			 */
116			if (p->flags & BR_PORT_MAB)
117				br_fdb_update(br, p, eth_hdr(skb)->h_source,
118					      vid, BIT(BR_FDB_LOCKED));
119			goto drop;
120		} else if (READ_ONCE(fdb_src->dst) != p ||
121			   test_bit(BR_FDB_LOCAL, &fdb_src->flags)) {
122			/* FDB mismatch. Drop the packet without roaming. */
123			goto drop;
124		} else if (test_bit(BR_FDB_LOCKED, &fdb_src->flags)) {
125			/* FDB match, but entry is locked. Refresh it and drop
126			 * the packet.
127			 */
128			br_fdb_update(br, p, eth_hdr(skb)->h_source, vid,
129				      BIT(BR_FDB_LOCKED));
130			goto drop;
131		}
132	}
133
134	nbp_switchdev_frame_mark(p, skb);
135
136	/* insert into forwarding database after filtering to avoid spoofing */
137	if (p->flags & BR_LEARNING)
138		br_fdb_update(br, p, eth_hdr(skb)->h_source, vid, 0);
139
140	local_rcv = !!(br->dev->flags & IFF_PROMISC);
141	if (is_multicast_ether_addr(eth_hdr(skb)->h_dest)) {
142		/* by definition the broadcast is also a multicast address */
143		if (is_broadcast_ether_addr(eth_hdr(skb)->h_dest)) {
144			pkt_type = BR_PKT_BROADCAST;
145			local_rcv = true;
146		} else {
147			pkt_type = BR_PKT_MULTICAST;
148			if (br_multicast_rcv(&brmctx, &pmctx, vlan, skb, vid))
149				goto drop;
150		}
151	}
152
153	if (state == BR_STATE_LEARNING)
154		goto drop;
155
156	BR_INPUT_SKB_CB(skb)->brdev = br->dev;
157	BR_INPUT_SKB_CB(skb)->src_port_isolated = !!(p->flags & BR_ISOLATED);
158
159	if (IS_ENABLED(CONFIG_INET) &&
160	    (skb->protocol == htons(ETH_P_ARP) ||
161	     skb->protocol == htons(ETH_P_RARP))) {
162		br_do_proxy_suppress_arp(skb, br, vid, p);
163	} else if (IS_ENABLED(CONFIG_IPV6) &&
164		   skb->protocol == htons(ETH_P_IPV6) &&
165		   br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED) &&
166		   pskb_may_pull(skb, sizeof(struct ipv6hdr) +
167				 sizeof(struct nd_msg)) &&
168		   ipv6_hdr(skb)->nexthdr == IPPROTO_ICMPV6) {
169			struct nd_msg *msg, _msg;
170
171			msg = br_is_nd_neigh_msg(skb, &_msg);
172			if (msg)
173				br_do_suppress_nd(skb, br, vid, p, msg);
174	}
175
176	switch (pkt_type) {
177	case BR_PKT_MULTICAST:
178		mdst = br_mdb_entry_skb_get(brmctx, skb, vid);
179		if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) &&
180		    br_multicast_querier_exists(brmctx, eth_hdr(skb), mdst)) {
181			if ((mdst && mdst->host_joined) ||
182			    br_multicast_is_router(brmctx, skb)) {
183				local_rcv = true;
184				DEV_STATS_INC(br->dev, multicast);
185			}
186			mcast_hit = true;
187		} else {
188			local_rcv = true;
189			DEV_STATS_INC(br->dev, multicast);
190		}
191		break;
192	case BR_PKT_UNICAST:
193		dst = br_fdb_find_rcu(br, eth_hdr(skb)->h_dest, vid);
194		break;
195	default:
196		break;
197	}
198
199	if (dst) {
200		unsigned long now = jiffies;
201
202		if (test_bit(BR_FDB_LOCAL, &dst->flags))
203			return br_pass_frame_up(skb);
204
205		if (now != dst->used)
206			dst->used = now;
207		br_forward(dst->dst, skb, local_rcv, false);
208	} else {
209		if (!mcast_hit)
210			br_flood(br, skb, pkt_type, local_rcv, false, vid);
211		else
212			br_multicast_flood(mdst, skb, brmctx, local_rcv, false);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
213	}
214
215	if (local_rcv)
216		return br_pass_frame_up(skb);
217
218out:
219	return 0;
220drop:
221	kfree_skb(skb);
222	goto out;
223}
224EXPORT_SYMBOL_GPL(br_handle_frame_finish);
225
226static void __br_handle_local_finish(struct sk_buff *skb)
227{
228	struct net_bridge_port *p = br_port_get_rcu(skb->dev);
229	u16 vid = 0;
230
231	/* check if vlan is allowed, to avoid spoofing */
232	if ((p->flags & BR_LEARNING) &&
233	    nbp_state_should_learn(p) &&
234	    !br_opt_get(p->br, BROPT_NO_LL_LEARN) &&
235	    br_should_learn(p, skb, &vid))
236		br_fdb_update(p->br, p, eth_hdr(skb)->h_source, vid, 0);
237}
238
239/* note: already called with rcu_read_lock */
240static int br_handle_local_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
241{
242	__br_handle_local_finish(skb);
243
244	/* return 1 to signal the okfn() was called so it's ok to use the skb */
245	return 1;
246}
247
248static int nf_hook_bridge_pre(struct sk_buff *skb, struct sk_buff **pskb)
249{
250#ifdef CONFIG_NETFILTER_FAMILY_BRIDGE
251	struct nf_hook_entries *e = NULL;
252	struct nf_hook_state state;
253	unsigned int verdict, i;
254	struct net *net;
255	int ret;
256
257	net = dev_net(skb->dev);
258#ifdef HAVE_JUMP_LABEL
259	if (!static_key_false(&nf_hooks_needed[NFPROTO_BRIDGE][NF_BR_PRE_ROUTING]))
260		goto frame_finish;
261#endif
262
263	e = rcu_dereference(net->nf.hooks_bridge[NF_BR_PRE_ROUTING]);
264	if (!e)
265		goto frame_finish;
266
267	nf_hook_state_init(&state, NF_BR_PRE_ROUTING,
268			   NFPROTO_BRIDGE, skb->dev, NULL, NULL,
269			   net, br_handle_frame_finish);
270
271	for (i = 0; i < e->num_hook_entries; i++) {
272		verdict = nf_hook_entry_hookfn(&e->hooks[i], skb, &state);
273		switch (verdict & NF_VERDICT_MASK) {
274		case NF_ACCEPT:
275			if (BR_INPUT_SKB_CB(skb)->br_netfilter_broute) {
276				*pskb = skb;
277				return RX_HANDLER_PASS;
278			}
279			break;
280		case NF_DROP:
281			kfree_skb(skb);
282			return RX_HANDLER_CONSUMED;
283		case NF_QUEUE:
284			ret = nf_queue(skb, &state, i, verdict);
285			if (ret == 1)
286				continue;
287			return RX_HANDLER_CONSUMED;
288		default: /* STOLEN */
289			return RX_HANDLER_CONSUMED;
290		}
291	}
292frame_finish:
293	net = dev_net(skb->dev);
294	br_handle_frame_finish(net, NULL, skb);
295#else
296	br_handle_frame_finish(dev_net(skb->dev), NULL, skb);
297#endif
298	return RX_HANDLER_CONSUMED;
299}
300
301/* Return 0 if the frame was not processed otherwise 1
302 * note: already called with rcu_read_lock
303 */
304static int br_process_frame_type(struct net_bridge_port *p,
305				 struct sk_buff *skb)
306{
307	struct br_frame_type *tmp;
308
309	hlist_for_each_entry_rcu(tmp, &p->br->frame_type_list, list)
310		if (unlikely(tmp->type == skb->protocol))
311			return tmp->frame_handler(p, skb);
312
313	return 0;
314}
315
316/*
317 * Return NULL if skb is handled
318 * note: already called with rcu_read_lock
319 */
320static rx_handler_result_t br_handle_frame(struct sk_buff **pskb)
321{
322	struct net_bridge_port *p;
323	struct sk_buff *skb = *pskb;
324	const unsigned char *dest = eth_hdr(skb)->h_dest;
 
325
326	if (unlikely(skb->pkt_type == PACKET_LOOPBACK))
327		return RX_HANDLER_PASS;
328
329	if (!is_valid_ether_addr(eth_hdr(skb)->h_source))
330		goto drop;
331
332	skb = skb_share_check(skb, GFP_ATOMIC);
333	if (!skb)
334		return RX_HANDLER_CONSUMED;
335
336	memset(skb->cb, 0, sizeof(struct br_input_skb_cb));
337	br_tc_skb_miss_set(skb, false);
338
339	p = br_port_get_rcu(skb->dev);
340	if (p->flags & BR_VLAN_TUNNEL)
341		br_handle_ingress_vlan_tunnel(skb, p, nbp_vlan_group_rcu(p));
342
343	if (unlikely(is_link_local_ether_addr(dest))) {
344		u16 fwd_mask = p->br->group_fwd_mask_required;
345
 
346		/*
347		 * See IEEE 802.1D Table 7-10 Reserved addresses
348		 *
349		 * Assignment		 		Value
350		 * Bridge Group Address		01-80-C2-00-00-00
351		 * (MAC Control) 802.3		01-80-C2-00-00-01
352		 * (Link Aggregation) 802.3	01-80-C2-00-00-02
353		 * 802.1X PAE address		01-80-C2-00-00-03
354		 *
355		 * 802.1AB LLDP 		01-80-C2-00-00-0E
356		 *
357		 * Others reserved for future standardization
358		 */
359		fwd_mask |= p->group_fwd_mask;
360		switch (dest[5]) {
361		case 0x00:	/* Bridge Group Address */
362			/* If STP is turned off,
363			   then must forward to keep loop detection */
364			if (p->br->stp_enabled == BR_NO_STP ||
365			    fwd_mask & (1u << dest[5]))
366				goto forward;
367			*pskb = skb;
368			__br_handle_local_finish(skb);
369			return RX_HANDLER_PASS;
370
371		case 0x01:	/* IEEE MAC (Pause) */
372			goto drop;
373
374		case 0x0E:	/* 802.1AB LLDP */
375			fwd_mask |= p->br->group_fwd_mask;
376			if (fwd_mask & (1u << dest[5]))
377				goto forward;
378			*pskb = skb;
379			__br_handle_local_finish(skb);
380			return RX_HANDLER_PASS;
381
382		default:
383			/* Allow selective forwarding for most other protocols */
384			fwd_mask |= p->br->group_fwd_mask;
385			if (fwd_mask & (1u << dest[5]))
386				goto forward;
387		}
388
389		/* The else clause should be hit when nf_hook():
390		 *   - returns < 0 (drop/error)
391		 *   - returns = 0 (stolen/nf_queue)
392		 * Thus return 1 from the okfn() to signal the skb is ok to pass
393		 */
394		if (NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN,
395			    dev_net(skb->dev), NULL, skb, skb->dev, NULL,
396			    br_handle_local_finish) == 1) {
397			return RX_HANDLER_PASS;
398		} else {
399			return RX_HANDLER_CONSUMED;
 
400		}
401	}
402
403	if (unlikely(br_process_frame_type(p, skb)))
404		return RX_HANDLER_PASS;
405
406forward:
407	if (br_mst_is_enabled(p->br))
408		goto defer_stp_filtering;
409
410	switch (p->state) {
411	case BR_STATE_FORWARDING:
 
 
 
 
 
 
 
 
 
412	case BR_STATE_LEARNING:
413defer_stp_filtering:
414		if (ether_addr_equal(p->br->dev->dev_addr, dest))
415			skb->pkt_type = PACKET_HOST;
416
417		return nf_hook_bridge_pre(skb, pskb);
 
 
418	default:
419drop:
420		kfree_skb(skb);
421	}
422	return RX_HANDLER_CONSUMED;
423}
424
425/* This function has no purpose other than to appease the br_port_get_rcu/rtnl
426 * helpers which identify bridged ports according to the rx_handler installed
427 * on them (so there _needs_ to be a bridge rx_handler even if we don't need it
428 * to do anything useful). This bridge won't support traffic to/from the stack,
429 * but only hardware bridging. So return RX_HANDLER_PASS so we don't steal
430 * frames from the ETH_P_XDSA packet_type handler.
431 */
432static rx_handler_result_t br_handle_frame_dummy(struct sk_buff **pskb)
433{
434	return RX_HANDLER_PASS;
435}
436
437rx_handler_func_t *br_get_rx_handler(const struct net_device *dev)
438{
439	if (netdev_uses_dsa(dev))
440		return br_handle_frame_dummy;
441
442	return br_handle_frame;
443}
444
445void br_add_frame(struct net_bridge *br, struct br_frame_type *ft)
446{
447	hlist_add_head_rcu(&ft->list, &br->frame_type_list);
448}
449
450void br_del_frame(struct net_bridge *br, struct br_frame_type *ft)
451{
452	struct br_frame_type *tmp;
453
454	hlist_for_each_entry(tmp, &br->frame_type_list, list)
455		if (ft == tmp) {
456			hlist_del_rcu(&ft->list);
457			return;
458		}
459}
v3.5.6
 
  1/*
  2 *	Handle incoming frames
  3 *	Linux ethernet bridge
  4 *
  5 *	Authors:
  6 *	Lennert Buytenhek		<buytenh@gnu.org>
  7 *
  8 *	This program is free software; you can redistribute it and/or
  9 *	modify it under the terms of the GNU General Public License
 10 *	as published by the Free Software Foundation; either version
 11 *	2 of the License, or (at your option) any later version.
 12 */
 13
 14#include <linux/slab.h>
 15#include <linux/kernel.h>
 16#include <linux/netdevice.h>
 17#include <linux/etherdevice.h>
 18#include <linux/netfilter_bridge.h>
 
 
 
 
 
 
 19#include <linux/export.h>
 
 20#include "br_private.h"
 
 21
 22/* Bridge group multicast address 802.1d (pg 51). */
 23const u8 br_group_address[ETH_ALEN] = { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 };
 24
 25/* Hook for brouter */
 26br_should_route_hook_t __rcu *br_should_route_hook __read_mostly;
 27EXPORT_SYMBOL(br_should_route_hook);
 28
 29static int br_pass_frame_up(struct sk_buff *skb)
 30{
 31	struct net_device *indev, *brdev = BR_INPUT_SKB_CB(skb)->brdev;
 32	struct net_bridge *br = netdev_priv(brdev);
 33	struct br_cpu_netstats *brstats = this_cpu_ptr(br->stats);
 
 
 
 
 34
 35	u64_stats_update_begin(&brstats->syncp);
 36	brstats->rx_packets++;
 37	brstats->rx_bytes += skb->len;
 38	u64_stats_update_end(&brstats->syncp);
 
 
 
 
 
 
 
 
 
 
 
 39
 40	indev = skb->dev;
 41	skb->dev = brdev;
 42
 43	return NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, skb, indev, NULL,
 44		       netif_receive_skb);
 
 
 
 
 
 
 
 45}
 46
 47/* note: already called with rcu_read_lock */
 48int br_handle_frame_finish(struct sk_buff *skb)
 49{
 50	const unsigned char *dest = eth_hdr(skb)->h_dest;
 51	struct net_bridge_port *p = br_port_get_rcu(skb->dev);
 
 
 
 
 
 
 
 52	struct net_bridge *br;
 53	struct net_bridge_fdb_entry *dst;
 54	struct net_bridge_mdb_entry *mdst;
 55	struct sk_buff *skb2;
 56
 57	if (!p || p->state == BR_STATE_DISABLED)
 58		goto drop;
 59
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 60	/* insert into forwarding database after filtering to avoid spoofing */
 61	br = p->br;
 62	br_fdb_update(br, p, eth_hdr(skb)->h_source);
 63
 64	if (!is_broadcast_ether_addr(dest) && is_multicast_ether_addr(dest) &&
 65	    br_multicast_rcv(br, p, skb))
 66		goto drop;
 
 
 
 
 
 
 
 
 
 67
 68	if (p->state == BR_STATE_LEARNING)
 69		goto drop;
 70
 71	BR_INPUT_SKB_CB(skb)->brdev = br->dev;
 
 72
 73	/* The packet skb2 goes to the local host (NULL to skip). */
 74	skb2 = NULL;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 75
 76	if (br->dev->flags & IFF_PROMISC)
 77		skb2 = skb;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 78
 79	dst = NULL;
 
 80
 81	if (is_broadcast_ether_addr(dest))
 82		skb2 = skb;
 83	else if (is_multicast_ether_addr(dest)) {
 84		mdst = br_mdb_get(br, skb);
 85		if (mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) {
 86			if ((mdst && mdst->mglist) ||
 87			    br_multicast_is_router(br))
 88				skb2 = skb;
 89			br_multicast_forward(mdst, skb, skb2);
 90			skb = NULL;
 91			if (!skb2)
 92				goto out;
 93		} else
 94			skb2 = skb;
 95
 96		br->dev->stats.multicast++;
 97	} else if ((dst = __br_fdb_get(br, dest)) && dst->is_local) {
 98		skb2 = skb;
 99		/* Do not forward the packet since it's local. */
100		skb = NULL;
101	}
102
103	if (skb) {
104		if (dst) {
105			dst->used = jiffies;
106			br_forward(dst->dst, skb, skb2);
107		} else
108			br_flood_forward(br, skb, skb2);
109	}
110
111	if (skb2)
112		return br_pass_frame_up(skb2);
113
114out:
115	return 0;
116drop:
117	kfree_skb(skb);
118	goto out;
119}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
120
121/* note: already called with rcu_read_lock */
122static int br_handle_local_finish(struct sk_buff *skb)
123{
124	struct net_bridge_port *p = br_port_get_rcu(skb->dev);
 
 
 
 
125
126	br_fdb_update(p->br, p, eth_hdr(skb)->h_source);
127	return 0;	 /* process further */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
128}
129
130/* Does address match the link local multicast address.
131 * 01:80:c2:00:00:0X
132 */
133static inline int is_link_local(const unsigned char *dest)
 
134{
135	__be16 *a = (__be16 *)dest;
136	static const __be16 *b = (const __be16 *)br_group_address;
137	static const __be16 m = cpu_to_be16(0xfff0);
 
 
138
139	return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | ((a[2] ^ b[2]) & m)) == 0;
140}
141
142/*
143 * Return NULL if skb is handled
144 * note: already called with rcu_read_lock
145 */
146rx_handler_result_t br_handle_frame(struct sk_buff **pskb)
147{
148	struct net_bridge_port *p;
149	struct sk_buff *skb = *pskb;
150	const unsigned char *dest = eth_hdr(skb)->h_dest;
151	br_should_route_hook_t *rhook;
152
153	if (unlikely(skb->pkt_type == PACKET_LOOPBACK))
154		return RX_HANDLER_PASS;
155
156	if (!is_valid_ether_addr(eth_hdr(skb)->h_source))
157		goto drop;
158
159	skb = skb_share_check(skb, GFP_ATOMIC);
160	if (!skb)
161		return RX_HANDLER_CONSUMED;
162
 
 
 
163	p = br_port_get_rcu(skb->dev);
 
 
 
 
 
164
165	if (unlikely(is_link_local(dest))) {
166		/*
167		 * See IEEE 802.1D Table 7-10 Reserved addresses
168		 *
169		 * Assignment		 		Value
170		 * Bridge Group Address		01-80-C2-00-00-00
171		 * (MAC Control) 802.3		01-80-C2-00-00-01
172		 * (Link Aggregation) 802.3	01-80-C2-00-00-02
173		 * 802.1X PAE address		01-80-C2-00-00-03
174		 *
175		 * 802.1AB LLDP 		01-80-C2-00-00-0E
176		 *
177		 * Others reserved for future standardization
178		 */
 
179		switch (dest[5]) {
180		case 0x00:	/* Bridge Group Address */
181			/* If STP is turned off,
182			   then must forward to keep loop detection */
183			if (p->br->stp_enabled == BR_NO_STP)
 
184				goto forward;
185			break;
 
 
186
187		case 0x01:	/* IEEE MAC (Pause) */
188			goto drop;
189
 
 
 
 
 
 
 
 
190		default:
191			/* Allow selective forwarding for most other protocols */
192			if (p->br->group_fwd_mask & (1u << dest[5]))
 
193				goto forward;
194		}
195
196		/* Deliver packet to local host only */
197		if (NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, skb, skb->dev,
198			    NULL, br_handle_local_finish)) {
199			return RX_HANDLER_CONSUMED; /* consumed by filter */
 
 
 
 
 
200		} else {
201			*pskb = skb;
202			return RX_HANDLER_PASS;	/* continue processing */
203		}
204	}
205
 
 
 
206forward:
 
 
 
207	switch (p->state) {
208	case BR_STATE_FORWARDING:
209		rhook = rcu_dereference(br_should_route_hook);
210		if (rhook) {
211			if ((*rhook)(skb)) {
212				*pskb = skb;
213				return RX_HANDLER_PASS;
214			}
215			dest = eth_hdr(skb)->h_dest;
216		}
217		/* fall through */
218	case BR_STATE_LEARNING:
 
219		if (ether_addr_equal(p->br->dev->dev_addr, dest))
220			skb->pkt_type = PACKET_HOST;
221
222		NF_HOOK(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
223			br_handle_frame_finish);
224		break;
225	default:
226drop:
227		kfree_skb(skb);
228	}
229	return RX_HANDLER_CONSUMED;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
230}