Release 4.14 net/bridge/br_input.c

/*
 *      Handle incoming frames
 *      Linux ethernet bridge
 *
 *      Authors:
 *      Lennert Buytenhek               <buytenh@gnu.org>
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */

#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/netfilter_bridge.h>
#include <linux/neighbour.h>
#include <net/arp.h>
#include <linux/export.h>
#include <linux/rculist.h>
#include "br_private.h"
#include "br_private_tunnel.h"

/* Hook for brouter */

br_should_route_hook_t __rcu *br_should_route_hook __read_mostly;

EXPORT_SYMBOL(br_should_route_hook);


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);
}

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Eric W. Biedermann
27
84.38%
2
66.67%
Florian Westphal
5
15.62%
1
33.33%
Total
32
100.00%
3
100.00%



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;
	struct pcpu_sw_netstats *brstats = this_cpu_ptr(br->stats);

	u64_stats_update_begin(&brstats->syncp);
	brstats->rx_packets++;
	brstats->rx_bytes += skb->len;
	u64_stats_update_end(&brstats->syncp);

	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);
}

Contributors
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Vlad Yasevich
63
32.81%
3
16.67%
Nikolay Aleksandrov
27
14.06%
3
16.67%
Linus Torvalds (pre-git)
24
12.50%
1
5.56%
Stephen Hemminger
21
10.94%
1
5.56%
Eric Dumazet
16
8.33%
1
5.56%
Linus Torvalds
13
6.77%
1
5.56%
Pavel Emelyanov
8
4.17%
1
5.56%
Herbert Xu
8
4.17%
1
5.56%
Eric W. Biedermann
6
3.12%
2
11.11%
Roopa Prabhu
2
1.04%
1
5.56%
David S. Miller
2
1.04%
1
5.56%
Li RongQing
1
0.52%
1
5.56%
Jan Engelhardt
1
0.52%
1
5.56%
Total
192
100.00%
18
100.00%



static void br_do_proxy_arp(struct sk_buff *skb, struct net_bridge *br,
			    u16 vid, struct net_bridge_port *p)
{
	struct net_device *dev = br->dev;
	struct neighbour *n;
	struct arphdr *parp;
	u8 *arpptr, *sha;
	__be32 sip, tip;

	BR_INPUT_SKB_CB(skb)->proxyarp_replied = false;

	if ((dev->flags & IFF_NOARP) ||
	    !pskb_may_pull(skb, arp_hdr_len(dev)))
		return;

	parp = arp_hdr(skb);

	if (parp->ar_pro != htons(ETH_P_IP) ||
	    parp->ar_op != htons(ARPOP_REQUEST) ||
	    parp->ar_hln != dev->addr_len ||
	    parp->ar_pln != 4)
		return;

	arpptr = (u8 *)parp + sizeof(struct arphdr);
	sha = arpptr;
	arpptr += dev->addr_len;	/* sha */
	memcpy(&sip, arpptr, sizeof(sip));
	arpptr += sizeof(sip);
	arpptr += dev->addr_len;	/* tha */
	memcpy(&tip, arpptr, sizeof(tip));

	if (ipv4_is_loopback(tip) ||
	    ipv4_is_multicast(tip))
		return;

	n = neigh_lookup(&arp_tbl, &tip, dev);
	if (n) {
		struct net_bridge_fdb_entry *f;

		if (!(n->nud_state & NUD_VALID)) {
			neigh_release(n);
			return;
		}

		f = br_fdb_find_rcu(br, n->ha, vid);
		if (f && ((p->flags & BR_PROXYARP) ||
			  (f->dst && (f->dst->flags & BR_PROXYARP_WIFI)))) {
			arp_send(ARPOP_REPLY, ETH_P_ARP, sip, skb->dev, tip,
				 sha, n->ha, sha);
			BR_INPUT_SKB_CB(skb)->proxyarp_replied = true;
		}

		neigh_release(n);
	}
}

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Kyeyoon Park
276
83.38%
1
25.00%
Jouni Malinen
51
15.41%
1
25.00%
Nikolay Aleksandrov
4
1.21%
2
50.00%
Total
331
100.00%
4
100.00%

/* 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;
	const unsigned char *dest;
	struct net_bridge *br;
	u16 vid = 0;

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

	if (!br_allowed_ingress(p->br, nbp_vlan_group_rcu(p), skb, &vid))
		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, false);

	local_rcv = !!(br->dev->flags & IFF_PROMISC);
	dest = eth_hdr(skb)->h_dest;
	if (is_multicast_ether_addr(dest)) {
		/* by definition the broadcast is also a multicast address */
		if (is_broadcast_ether_addr(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 (p->state == BR_STATE_LEARNING)
		goto drop;

	BR_INPUT_SKB_CB(skb)->brdev = br->dev;

	if (IS_ENABLED(CONFIG_INET) && skb->protocol == htons(ETH_P_ARP))
		br_do_proxy_arp(skb, br, vid, p);

	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))) {
			if ((mdst && mdst->mglist) ||
			    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, dest, vid);
	default:
		break;
	}

	if (dst) {
		unsigned long now = jiffies;

		if (dst->is_local)
			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;
}
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Nikolay Aleksandrov
163
33.20%
10
21.28%
Herbert Xu
91
18.53%
6
12.77%
Stephen Hemminger
86
17.52%
7
14.89%
Linus Torvalds (pre-git)
43
8.76%
2
4.26%
Vlad Yasevich
34
6.92%
6
12.77%
Kyeyoon Park
18
3.67%
1
2.13%
Linus Lüssing
12
2.44%
2
4.26%
Linus Torvalds
8
1.63%
1
2.13%
Ido Schimmel
7
1.43%
1
2.13%
David S. Miller
5
1.02%
1
2.13%
Eric W. Biedermann
5
1.02%
1
2.13%
Arnd Bergmann
5
1.02%
1
2.13%
Pavel Emelyanov
3
0.61%
1
2.13%
Toshiaki Makita
3
0.61%
2
4.26%
Jouni Malinen
3
0.61%
1
2.13%
Américo Wang
2
0.41%
1
2.13%
Michael Braun
1
0.20%
1
2.13%
Jiri Pirko
1
0.20%
1
2.13%
Hideaki Yoshifuji / 吉藤英明
1
0.20%
1
2.13%
Total
491
100.00%
47
100.00%


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 && br_should_learn(p, skb, &vid))
		br_fdb_update(p->br, p, eth_hdr(skb)->h_source, vid, false);
}

Contributors
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Stephen Hemminger
35
52.24%
1
14.29%
Vlad Yasevich
15
22.39%
2
28.57%
Toshiaki Makita
13
19.40%
2
28.57%
Ido Schimmel
3
4.48%
1
14.29%
Jiri Pirko
1
1.49%
1
14.29%
Total
67
100.00%
7
100.00%

/* note: already called with rcu_read_lock */


static int br_handle_local_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
{
	struct net_bridge_port *p = br_port_get_rcu(skb->dev);

	__br_handle_local_finish(skb);

	BR_INPUT_SKB_CB(skb)->brdev = p->br->dev;
	br_pass_frame_up(skb);
	return 0;
}

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Ido Schimmel
37
62.71%
1
33.33%
Florian Westphal
18
30.51%
1
33.33%
Stephen Hemminger
4
6.78%
1
33.33%
Total
59
100.00%
3
100.00%

/*
 * Return NULL if skb is handled
 * note: already called with rcu_read_lock
 */


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;
	br_should_route_hook_t *rhook;

	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;

	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
                 */
		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;
		}

		/* Deliver packet to local host only */
		NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, dev_net(skb->dev),
			NULL, skb, skb->dev, NULL, br_handle_local_finish);
		return RX_HANDLER_CONSUMED;
	}

forward:
	switch (p->state) {
	case BR_STATE_FORWARDING:
		rhook = rcu_dereference(br_should_route_hook);
		if (rhook) {
			if ((*rhook)(skb)) {
				*pskb = skb;
				return RX_HANDLER_PASS;
			}
			dest = eth_hdr(skb)->h_dest;
		}
		/* fall through */
	case BR_STATE_LEARNING:
		if (ether_addr_equal(p->br->dev->dev_addr, dest))
			skb->pkt_type = PACKET_HOST;

		NF_HOOK(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING,
			dev_net(skb->dev), NULL, skb, skb->dev, NULL,
			br_handle_frame_finish);
		break;
	default:
drop:
		kfree_skb(skb);
	}
	return RX_HANDLER_CONSUMED;
}
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Stephen Hemminger
112
26.73%
12
32.43%
Ido Schimmel
54
12.89%
2
5.41%
Jiri Pirko
49
11.69%
3
8.11%
Linus Torvalds
45
10.74%
2
5.41%
Roopa Prabhu
27
6.44%
1
2.70%
Bart De Schuymer
27
6.44%
3
8.11%
Toshiaki Makita
26
6.21%
1
2.70%
Herbert Xu
16
3.82%
1
2.70%
Eric W. Biedermann
14
3.34%
1
2.70%
Pavel Emelyanov
11
2.63%
1
2.70%
Arnaldo Carvalho de Melo
9
2.15%
1
2.70%
David S. Miller
8
1.91%
2
5.41%
Linus Torvalds (pre-git)
8
1.91%
1
2.70%
Eric Dumazet
5
1.19%
1
2.70%
Simon Horman
3
0.72%
1
2.70%
Jan Engelhardt
2
0.48%
1
2.70%
Florian Westphal
1
0.24%
1
2.70%
Joe Perches
1
0.24%
1
2.70%
Ben Hutchings
1
0.24%
1
2.70%
Total
419
100.00%
37
100.00%

Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
Kyeyoon Park
300
18.24%
1
1.04%
Stephen Hemminger
259
15.74%
20
20.83%
Nikolay Aleksandrov
194
11.79%
13
13.54%
Herbert Xu
115
6.99%
7
7.29%
Vlad Yasevich
115
6.99%
8
8.33%
Ido Schimmel
102
6.20%
3
3.12%
Linus Torvalds (pre-git)
87
5.29%
2
2.08%
Linus Torvalds
69
4.19%
2
2.08%
Jouni Malinen
54
3.28%
1
1.04%
Eric W. Biedermann
52
3.16%
3
3.12%
Jiri Pirko
51
3.10%
3
3.12%
Toshiaki Makita
42
2.55%
4
4.17%
Eric Dumazet
33
2.01%
2
2.08%
Roopa Prabhu
32
1.95%
1
1.04%
Bart De Schuymer
27
1.64%
3
3.12%
Florian Westphal
24
1.46%
2
2.08%
Pavel Emelyanov
22
1.34%
2
2.08%
David S. Miller
16
0.97%
3
3.12%
Linus Lüssing
12
0.73%
2
2.08%
Arnaldo Carvalho de Melo
9
0.55%
1
1.04%
Pablo Neira Ayuso
5
0.30%
1
1.04%
Arnd Bergmann
5
0.30%
1
1.04%
Paul Gortmaker
3
0.18%
1
1.04%
Simon Horman
3
0.18%
1
1.04%
Jan Engelhardt
3
0.18%
1
1.04%
Tejun Heo
3
0.18%
1
1.04%
Américo Wang
2
0.12%
1
1.04%
Ben Hutchings
1
0.06%
1
1.04%
Hideaki Yoshifuji / 吉藤英明
1
0.06%
1
1.04%
Joe Perches
1
0.06%
1
1.04%
Li RongQing
1
0.06%
1
1.04%
Michael Braun
1
0.06%
1
1.04%
Adrian Bunk
1
0.06%
1
1.04%
Total
1645
100.00%
96
100.00%
Directory: net/bridge

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