Release 4.11 net/bridge/br_multicast.c

/*
 * Bridge multicast support.
 *
 * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au>
 *
 * 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/err.h>
#include <linux/export.h>
#include <linux/if_ether.h>
#include <linux/igmp.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 <net/ipv6.h>
#include <net/mld.h>
#include <net/ip6_checksum.h>
#include <net/addrconf.h>
#endif

#include "br_private.h"

static void br_multicast_start_querier(struct net_bridge *br,
				       struct bridge_mcast_own_query *query);
static void br_multicast_add_router(struct net_bridge *br,
				    struct net_bridge_port *port);
static void br_ip4_multicast_leave_group(struct net_bridge *br,
					 struct net_bridge_port *port,
					 __be32 group,
					 __u16 vid,
					 const unsigned char *src);

static void __del_port_router(struct net_bridge_port *p);
#if IS_ENABLED(CONFIG_IPV6)
static void br_ip6_multicast_leave_group(struct net_bridge *br,
					 struct net_bridge_port *port,
					 const struct in6_addr *group,
					 __u16 vid, const unsigned char *src);
#endif

unsigned int br_mdb_rehash_seq;



static inline int br_ip_equal(const struct br_ip *a, const struct br_ip *b)
{
	if (a->proto != b->proto)
		return 0;
	if (a->vid != b->vid)
		return 0;
	switch (a->proto) {
	case htons(ETH_P_IP):
		return a->u.ip4 == b->u.ip4;
#if IS_ENABLED(CONFIG_IPV6)
	case htons(ETH_P_IPV6):
		return ipv6_addr_equal(&a->u.ip6, &b->u.ip6);
#endif
	}
	return 0;
}

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Hideaki Yoshifuji / 吉藤英明
90
84.11%
2
40.00%
Vlad Yasevich
13
12.15%
1
20.00%
Herbert Xu
3
2.80%
1
20.00%
Eric Dumazet
1
0.93%
1
20.00%
Total
107
100.00%
5
100.00%



static inline int __br_ip4_hash(struct net_bridge_mdb_htable *mdb, __be32 ip,
				__u16 vid)
{
	return jhash_2words((__force u32)ip, vid, mdb->secret) & (mdb->max - 1);
}

Contributors
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Herbert Xu
27
64.29%
1
25.00%
Vlad Yasevich
10
23.81%
1
25.00%
Hideaki Yoshifuji / 吉藤英明
4
9.52%
1
25.00%
Eric Dumazet
1
2.38%
1
25.00%
Total
42
100.00%
4
100.00%

#if IS_ENABLED(CONFIG_IPV6)


static inline int __br_ip6_hash(struct net_bridge_mdb_htable *mdb,
				const struct in6_addr *ip,
				__u16 vid)
{
	return jhash_2words(ipv6_addr_hash(ip), vid,
			    mdb->secret) & (mdb->max - 1);
}
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Hideaki Yoshifuji / 吉藤英明
24
54.55%
1
33.33%
Herbert Xu
12
27.27%
1
33.33%
Vlad Yasevich
8
18.18%
1
33.33%
Total
44
100.00%
3
100.00%

#endif



static inline int br_ip_hash(struct net_bridge_mdb_htable *mdb,
			     struct br_ip *ip)
{
	switch (ip->proto) {
	case htons(ETH_P_IP):
		return __br_ip4_hash(mdb, ip->u.ip4, ip->vid);
#if IS_ENABLED(CONFIG_IPV6)
	case htons(ETH_P_IPV6):
		return __br_ip6_hash(mdb, &ip->u.ip6, ip->vid);
#endif
	}
	return 0;
}

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Hideaki Yoshifuji / 吉藤英明
72
88.89%
2
50.00%
Vlad Yasevich
8
9.88%
1
25.00%
Eric Dumazet
1
1.23%
1
25.00%
Total
81
100.00%
4
100.00%



static struct net_bridge_mdb_entry *__br_mdb_ip_get(
	struct net_bridge_mdb_htable *mdb, struct br_ip *dst, int hash)
{
	struct net_bridge_mdb_entry *mp;

	hlist_for_each_entry_rcu(mp, &mdb->mhash[hash], hlist[mdb->ver]) {
		if (br_ip_equal(&mp->addr, dst))
			return mp;
	}

	return NULL;
}

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Herbert Xu
45
83.33%
2
66.67%
Hideaki Yoshifuji / 吉藤英明
9
16.67%
1
33.33%
Total
54
100.00%
3
100.00%



struct net_bridge_mdb_entry *br_mdb_ip_get(struct net_bridge_mdb_htable *mdb,
					   struct br_ip *dst)
{
	if (!mdb)
		return NULL;

	return __br_mdb_ip_get(mdb, dst, br_ip_hash(mdb, dst));
}

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Herbert Xu
40
100.00%
1
100.00%
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40
100.00%
1
100.00%



static struct net_bridge_mdb_entry *br_mdb_ip4_get(
	struct net_bridge_mdb_htable *mdb, __be32 dst, __u16 vid)
{
	struct br_ip br_dst;

	br_dst.u.ip4 = dst;
	br_dst.proto = htons(ETH_P_IP);
	br_dst.vid = vid;

	return br_mdb_ip_get(mdb, &br_dst);
}

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Hideaki Yoshifuji / 吉藤英明
29
52.73%
1
20.00%
Herbert Xu
17
30.91%
3
60.00%
Vlad Yasevich
9
16.36%
1
20.00%
Total
55
100.00%
5
100.00%

#if IS_ENABLED(CONFIG_IPV6)


static struct net_bridge_mdb_entry *br_mdb_ip6_get(
	struct net_bridge_mdb_htable *mdb, const struct in6_addr *dst,
	__u16 vid)
{
	struct br_ip br_dst;

	br_dst.u.ip6 = *dst;
	br_dst.proto = htons(ETH_P_IPV6);
	br_dst.vid = vid;

	return br_mdb_ip_get(mdb, &br_dst);
}
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Hideaki Yoshifuji / 吉藤英明
47
79.66%
1
25.00%
Vlad Yasevich
9
15.25%
1
25.00%
Alexey Dobriyan
2
3.39%
1
25.00%
Herbert Xu
1
1.69%
1
25.00%
Total
59
100.00%
4
100.00%

#endif



struct net_bridge_mdb_entry *br_mdb_get(struct net_bridge *br,
					struct sk_buff *skb, u16 vid)
{
	struct net_bridge_mdb_htable *mdb = rcu_dereference(br->mdb);
	struct br_ip ip;

	if (br->multicast_disabled)
		return NULL;

	if (BR_INPUT_SKB_CB(skb)->igmp)
		return NULL;

	ip.proto = skb->protocol;
	ip.vid = vid;

	switch (skb->protocol) {
	case htons(ETH_P_IP):
		ip.u.ip4 = ip_hdr(skb)->daddr;
		break;
#if IS_ENABLED(CONFIG_IPV6)
	case htons(ETH_P_IPV6):
		ip.u.ip6 = ipv6_hdr(skb)->daddr;
		break;
#endif
	default:
		return NULL;
	}

	return br_mdb_ip_get(mdb, &ip);
}

Contributors
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Hideaki Yoshifuji / 吉藤英明
67
47.86%
2
28.57%
Herbert Xu
59
42.14%
1
14.29%
Américo Wang
9
6.43%
1
14.29%
Eric Dumazet
4
2.86%
2
28.57%
Alexey Dobriyan
1
0.71%
1
14.29%
Total
140
100.00%
7
100.00%



static void br_mdb_free(struct rcu_head *head)
{
	struct net_bridge_mdb_htable *mdb =
		container_of(head, struct net_bridge_mdb_htable, rcu);
	struct net_bridge_mdb_htable *old = mdb->old;

	mdb->old = NULL;
	kfree(old->mhash);
	kfree(old);
}

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53
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53
100.00%
1
100.00%



static int br_mdb_copy(struct net_bridge_mdb_htable *new,
		       struct net_bridge_mdb_htable *old,
		       int elasticity)
{
	struct net_bridge_mdb_entry *mp;
	int maxlen;
	int len;
	int i;

	for (i = 0; i < old->max; i++)
		hlist_for_each_entry(mp, &old->mhash[i], hlist[old->ver])
			hlist_add_head(&mp->hlist[new->ver],
				       &new->mhash[br_ip_hash(new, &mp->addr)]);

	if (!elasticity)
		return 0;

	maxlen = 0;
	for (i = 0; i < new->max; i++) {
		len = 0;
		hlist_for_each_entry(mp, &new->mhash[i], hlist[new->ver])
			len++;
		if (len > maxlen)
			maxlen = len;
	}

	return maxlen > elasticity ? -EINVAL : 0;
}

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Herbert Xu
148
99.33%
1
50.00%
Hideaki Yoshifuji / 吉藤英明
1
0.67%
1
50.00%
Total
149
100.00%
2
100.00%



void br_multicast_free_pg(struct rcu_head *head)
{
	struct net_bridge_port_group *p =
		container_of(head, struct net_bridge_port_group, rcu);

	kfree(p);
}

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30
100.00%
1
100.00%



static void br_multicast_free_group(struct rcu_head *head)
{
	struct net_bridge_mdb_entry *mp =
		container_of(head, struct net_bridge_mdb_entry, rcu);

	kfree(mp);
}

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31
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31
100.00%
1
100.00%



static void br_multicast_group_expired(unsigned long data)
{
	struct net_bridge_mdb_entry *mp = (void *)data;
	struct net_bridge *br = mp->br;
	struct net_bridge_mdb_htable *mdb;

	spin_lock(&br->multicast_lock);
	if (!netif_running(br->dev) || timer_pending(&mp->timer))
		goto out;

	mp->mglist = false;

	if (mp->ports)
		goto out;

	mdb = mlock_dereference(br->mdb, br);

	hlist_del_rcu(&mp->hlist[mdb->ver]);
	mdb->size--;

	call_rcu_bh(&mp->rcu, br_multicast_free_group);

out:
	spin_unlock(&br->multicast_lock);
}

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Herbert Xu
123
96.09%
2
66.67%
Eric Dumazet
5
3.91%
1
33.33%
Total
128
100.00%
3
100.00%



static void br_multicast_del_pg(struct net_bridge *br,
				struct net_bridge_port_group *pg)
{
	struct net_bridge_mdb_htable *mdb;
	struct net_bridge_mdb_entry *mp;
	struct net_bridge_port_group *p;
	struct net_bridge_port_group __rcu **pp;

	mdb = mlock_dereference(br->mdb, br);

	mp = br_mdb_ip_get(mdb, &pg->addr);
	if (WARN_ON(!mp))
		return;

	for (pp = &mp->ports;
	     (p = mlock_dereference(*pp, br)) != NULL;
	     pp = &p->next) {
		if (p != pg)
			continue;

		rcu_assign_pointer(*pp, p->next);
		hlist_del_init(&p->mglist);
		del_timer(&p->timer);
		br_mdb_notify(br->dev, p->port, &pg->addr, RTM_DELMDB,
			      p->flags);
		call_rcu_bh(&p->rcu, br_multicast_free_pg);

		if (!mp->ports && !mp->mglist &&
		    netif_running(br->dev))
			mod_timer(&mp->timer, jiffies);

		return;
	}

	WARN_ON(1);
}

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Herbert Xu
156
77.23%
2
28.57%
Eric Dumazet
19
9.41%
1
14.29%
Elad Raz
11
5.45%
1
14.29%
Nikolay Aleksandrov
11
5.45%
1
14.29%
Stephen Hemminger
4
1.98%
1
14.29%
Hideaki Yoshifuji / 吉藤英明
1
0.50%
1
14.29%
Total
202
100.00%
7
100.00%



static void br_multicast_port_group_expired(unsigned long data)
{
	struct net_bridge_port_group *pg = (void *)data;
	struct net_bridge *br = pg->port->br;

	spin_lock(&br->multicast_lock);
	if (!netif_running(br->dev) || timer_pending(&pg->timer) ||
	    hlist_unhashed(&pg->mglist) || pg->flags & MDB_PG_FLAGS_PERMANENT)
		goto out;

	br_multicast_del_pg(br, pg);

out:
	spin_unlock(&br->multicast_lock);
}

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Herbert Xu
86
93.48%
1
33.33%
Américo Wang
4
4.35%
1
33.33%
Elad Raz
2
2.17%
1
33.33%
Total
92
100.00%
3
100.00%



static int br_mdb_rehash(struct net_bridge_mdb_htable __rcu **mdbp, int max,
			 int elasticity)
{
	struct net_bridge_mdb_htable *old = rcu_dereference_protected(*mdbp, 1);
	struct net_bridge_mdb_htable *mdb;
	int err;

	mdb = kmalloc(sizeof(*mdb), GFP_ATOMIC);
	if (!mdb)
		return -ENOMEM;

	mdb->max = max;
	mdb->old = old;

	mdb->mhash = kzalloc(max * sizeof(*mdb->mhash), GFP_ATOMIC);
	if (!mdb->mhash) {
		kfree(mdb);
		return -ENOMEM;
	}

	mdb->size = old ? old->size : 0;
	mdb->ver = old ? old->ver ^ 1 : 0;

	if (!old || elasticity)
		get_random_bytes(&mdb->secret, sizeof(mdb->secret));
	else
		mdb->secret = old->secret;

	if (!old)
		goto out;

	err = br_mdb_copy(mdb, old, elasticity);
	if (err) {
		kfree(mdb->mhash);
		kfree(mdb);
		return err;
	}

	br_mdb_rehash_seq++;
	call_rcu_bh(&mdb->rcu, br_mdb_free);

out:
	rcu_assign_pointer(*mdbp, mdb);

	return 0;
}

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Herbert Xu
225
96.15%
1
33.33%
Eric Dumazet
6
2.56%
1
33.33%
Américo Wang
3
1.28%
1
33.33%
Total
234
100.00%
3
100.00%



static struct sk_buff *br_ip4_multicast_alloc_query(struct net_bridge *br,
						    __be32 group,
						    u8 *igmp_type)
{
	struct igmpv3_query *ihv3;
	size_t igmp_hdr_size;
	struct sk_buff *skb;
	struct igmphdr *ih;
	struct ethhdr *eth;
	struct iphdr *iph;

	igmp_hdr_size = sizeof(*ih);
	if (br->multicast_igmp_version == 3)
		igmp_hdr_size = sizeof(*ihv3);
	skb = netdev_alloc_skb_ip_align(br->dev, sizeof(*eth) + sizeof(*iph) +
						 igmp_hdr_size + 4);
	if (!skb)
		goto out;

	skb->protocol = htons(ETH_P_IP);

	skb_reset_mac_header(skb);
	eth = eth_hdr(skb);

	ether_addr_copy(eth->h_source, br->dev->dev_addr);
	eth->h_dest[0] = 1;
	eth->h_dest[1] = 0;
	eth->h_dest[2] = 0x5e;
	eth->h_dest[3] = 0;
	eth->h_dest[4] = 0;
	eth->h_dest[5] = 1;
	eth->h_proto = htons(ETH_P_IP);
	skb_put(skb, sizeof(*eth));

	skb_set_network_header(skb, skb->len);
	iph = ip_hdr(skb);

	iph->version = 4;
	iph->ihl = 6;
	iph->tos = 0xc0;
	iph->tot_len = htons(sizeof(*iph) + igmp_hdr_size + 4);
	iph->id = 0;
	iph->frag_off = htons(IP_DF);
	iph->ttl = 1;
	iph->protocol = IPPROTO_IGMP;
	iph->saddr = br->multicast_query_use_ifaddr ?
		     inet_select_addr(br->dev, 0, RT_SCOPE_LINK) : 0;
	iph->daddr = htonl(INADDR_ALLHOSTS_GROUP);
	((u8 *)&iph[1])[0] = IPOPT_RA;
	((u8 *)&iph[1])[1] = 4;
	((u8 *)&iph[1])[2] = 0;
	((u8 *)&iph[1])[3] = 0;
	ip_send_check(iph);
	skb_put(skb, 24);

	skb_set_transport_header(skb, skb->len);
	*igmp_type = IGMP_HOST_MEMBERSHIP_QUERY;

	switch (br->multicast_igmp_version) {
	case 2:
		ih = igmp_hdr(skb);
		ih->type = IGMP_HOST_MEMBERSHIP_QUERY;
		ih->code = (group ? br->multicast_last_member_interval :
				    br->multicast_query_response_interval) /
			   (HZ / IGMP_TIMER_SCALE);
		ih->group = group;
		ih->csum = 0;
		ih->csum = ip_compute_csum((void *)ih, sizeof(*ih));
		break;
	case 3:
		ihv3 = igmpv3_query_hdr(skb);
		ihv3->type = IGMP_HOST_MEMBERSHIP_QUERY;
		ihv3->code = (group ? br->multicast_last_member_interval :
				      br->multicast_query_response_interval) /
			     (HZ / IGMP_TIMER_SCALE);
		ihv3->group = group;
		ihv3->qqic = br->multicast_query_interval / HZ;
		ihv3->nsrcs = 0;
		ihv3->resv = 0;
		ihv3->suppress = 0;
		ihv3->qrv = 2;
		ihv3->csum = 0;
		ihv3->csum = ip_compute_csum((void *)ihv3, sizeof(*ihv3));
		break;
	}

	skb_put(skb, igmp_hdr_size);
	__skb_pull(skb, sizeof(*eth));

out:
	return skb;
}

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Herbert Xu
444
71.61%
1
16.67%
Nikolay Aleksandrov
159
25.65%
2
33.33%
Américo Wang
15
2.42%
1
16.67%
Joe Perches
1
0.16%
1
16.67%
Hideaki Yoshifuji / 吉藤英明
1
0.16%
1
16.67%
Total
620
100.00%
6
100.00%

#if IS_ENABLED(CONFIG_IPV6)


static struct sk_buff *br_ip6_multicast_alloc_query(struct net_bridge *br,
						    const struct in6_addr *grp,
						    u8 *igmp_type)
{
	struct mld2_query *mld2q;
	unsigned long interval;
	struct ipv6hdr *ip6h;
	struct mld_msg *mldq;
	size_t mld_hdr_size;
	struct sk_buff *skb;
	struct ethhdr *eth;
	u8 *hopopt;

	mld_hdr_size = sizeof(*mldq);
	if (br->multicast_mld_version == 2)
		mld_hdr_size = sizeof(*mld2q);
	skb = netdev_alloc_skb_ip_align(br->dev, sizeof(*eth) + sizeof(*ip6h) +
						 8 + mld_hdr_size);
	if (!skb)
		goto out;

	skb->protocol = htons(ETH_P_IPV6);

	/* Ethernet header */
	skb_reset_mac_header(skb);
	eth = eth_hdr(skb);

	ether_addr_copy(eth->h_source, br->dev->dev_addr);
	eth->h_proto = htons(ETH_P_IPV6);
	skb_put(skb, sizeof(*eth));

	/* IPv6 header + HbH option */
	skb_set_network_header(skb, skb->len);
	ip6h = ipv6_hdr(skb);

	*(__force __be32 *)ip6h = htonl(0x60000000);
	ip6h->payload_len = htons(8 + mld_hdr_size);
	ip6h->nexthdr = IPPROTO_HOPOPTS;
	ip6h->hop_limit = 1;
	ipv6_addr_set(&ip6h->daddr, htonl(0xff020000), 0, 0, htonl(1));
	if (ipv6_dev_get_saddr(dev_net(br->dev), br->dev, &ip6h->daddr, 0,
			       &ip6h->saddr)) {
		kfree_skb(skb);
		br->has_ipv6_addr = 0;
		return NULL;
	}

	br->has_ipv6_addr = 1;
	ipv6_eth_mc_map(&ip6h->daddr, eth->h_dest);

	hopopt = (u8 *)(ip6h + 1);
	hopopt[0] = IPPROTO_ICMPV6;		/* next hdr */
	hopopt[1] = 0;				/* length of HbH */
	hopopt[2] = IPV6_TLV_ROUTERALERT;	/* Router Alert */
	hopopt[3] = 2;				/* Length of RA Option */
	hopopt[4] = 0;				/* Type = 0x0000 (MLD) */
	hopopt[5] = 0;
	hopopt[6] = IPV6_TLV_PAD1;		/* Pad1 */
	hopopt[7] = IPV6_TLV_PAD1;		/* Pad1 */

	skb_put(skb, sizeof(*ip6h) + 8);

	/* ICMPv6 */
	skb_set_transport_header(skb, skb->len);
	interval = ipv6_addr_any(grp) ?
			br->multicast_query_response_interval :
			br->multicast_last_member_interval;
	*igmp_type = ICMPV6_MGM_QUERY;
	switch (br->multicast_mld_version) {
	case 1:
		mldq = (struct mld_msg *)icmp6_hdr(skb);
		mldq->mld_type = ICMPV6_MGM_QUERY;
		mldq->mld_code = 0;
		mldq->mld_cksum = 0;
		mldq->mld_maxdelay = htons((u16)jiffies_to_msecs(interval));
		mldq->mld_reserved = 0;
		mldq->mld_mca = *grp;
		mldq->mld_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
						  sizeof(*mldq), IPPROTO_ICMPV6,
						  csum_partial(mldq,
							       sizeof(*mldq),
							       0));
		break;
	case 2:
		mld2q = (struct mld2_query *)icmp6_hdr(skb);
		mld2q->mld2q_mrc = htons((u16)jiffies_to_msecs(interval));
		mld2q->mld2q_type = ICMPV6_MGM_QUERY;
		mld2q->mld2q_code = 0;
		mld2q->mld2q_cksum = 0;
		mld2q->mld2q_resv1 = 0;
		mld2q->mld2q_resv2 = 0;
		mld2q->mld2q_suppress = 0;
		mld2q->mld2q_qrv = 2;
		mld2q->mld2q_nsrcs = 0;
		mld2q->mld2q_qqic = br->multicast_query_interval / HZ;
		mld2q->mld2q_mca = *grp;
		mld2q->mld2q_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
						     sizeof(*mld2q),
						     IPPROTO_ICMPV6,
						     csum_partial(mld2q,
								  sizeof(*mld2q),
								  0));
		break;
	}
	skb_put(skb