1 files changed, 481 insertions, 0 deletions

diff --git a/net/bridge/br_mdb.c b/net/bridge/br_mdb.c
new file mode 100644
index 0000000..6f0a2ee
--- /dev/null
+++ b/net/bridge/br_mdb.c
@@ -0,0 +1,481 @@
+#include <linux/err.h>
+#include <linux/igmp.h>
+#include <linux/kernel.h>
+#include <linux/netdevice.h>
+#include <linux/rculist.h>
+#include <linux/skbuff.h>
+#include <linux/if_ether.h>
+#include <net/ip.h>
+#include <net/netlink.h>
+#if IS_ENABLED(CONFIG_IPV6)
+#include <net/ipv6.h>
+#endif
+
+#include "br_private.h"
+
+static int br_rports_fill_info(struct sk_buff *skb, struct netlink_callback *cb,
+			       struct net_device *dev)
+{
+	struct net_bridge *br = netdev_priv(dev);
+	struct net_bridge_port *p;
+	struct hlist_node *n;
+	struct nlattr *nest;
+
+	if (!br->multicast_router || hlist_empty(&br->router_list))
+		return 0;
+
+	nest = nla_nest_start(skb, MDBA_ROUTER);
+	if (nest == NULL)
+		return -EMSGSIZE;
+
+	hlist_for_each_entry_rcu(p, n, &br->router_list, rlist) {
+		if (p && nla_put_u32(skb, MDBA_ROUTER_PORT, p->dev->ifindex))
+			goto fail;
+	}
+
+	nla_nest_end(skb, nest);
+	return 0;
+fail:
+	nla_nest_cancel(skb, nest);
+	return -EMSGSIZE;
+}
+
+static int br_mdb_fill_info(struct sk_buff *skb, struct netlink_callback *cb,
+			    struct net_device *dev)
+{
+	struct net_bridge *br = netdev_priv(dev);
+	struct net_bridge_mdb_htable *mdb;
+	struct nlattr *nest, *nest2;
+	int i, err = 0;
+	int idx = 0, s_idx = cb->args[1];
+
+	if (br->multicast_disabled)
+		return 0;
+
+	mdb = rcu_dereference(br->mdb);
+	if (!mdb)
+		return 0;
+
+	nest = nla_nest_start(skb, MDBA_MDB);
+	if (nest == NULL)
+		return -EMSGSIZE;
+
+	for (i = 0; i < mdb->max; i++) {
+		struct hlist_node *h;
+		struct net_bridge_mdb_entry *mp;
+		struct net_bridge_port_group *p, **pp;
+		struct net_bridge_port *port;
+
+		hlist_for_each_entry_rcu(mp, h, &mdb->mhash[i], hlist[mdb->ver]) {
+			if (idx < s_idx)
+				goto skip;
+
+			nest2 = nla_nest_start(skb, MDBA_MDB_ENTRY);
+			if (nest2 == NULL) {
+				err = -EMSGSIZE;
+				goto out;
+			}
+
+			for (pp = &mp->ports;
+			     (p = rcu_dereference(*pp)) != NULL;
+			      pp = &p->next) {
+				port = p->port;
+				if (port) {
+					struct br_mdb_entry e;
+					e.ifindex = port->dev->ifindex;
+					e.addr.u.ip4 = p->addr.u.ip4;
+#if IS_ENABLED(CONFIG_IPV6)
+					e.addr.u.ip6 = p->addr.u.ip6;
+#endif
+					e.addr.proto = p->addr.proto;
+					if (nla_put(skb, MDBA_MDB_ENTRY_INFO, sizeof(e), &e)) {
+						nla_nest_cancel(skb, nest2);
+						err = -EMSGSIZE;
+						goto out;
+					}
+				}
+			}
+			nla_nest_end(skb, nest2);
+		skip:
+			idx++;
+		}
+	}
+
+out:
+	cb->args[1] = idx;
+	nla_nest_end(skb, nest);
+	return err;
+}
+
+static int br_mdb_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	struct net_device *dev;
+	struct net *net = sock_net(skb->sk);
+	struct nlmsghdr *nlh = NULL;
+	int idx = 0, s_idx;
+
+	s_idx = cb->args[0];
+
+	rcu_read_lock();
+
+	/* In theory this could be wrapped to 0... */
+	cb->seq = net->dev_base_seq + br_mdb_rehash_seq;
+
+	for_each_netdev_rcu(net, dev) {
+		if (dev->priv_flags & IFF_EBRIDGE) {
+			struct br_port_msg *bpm;
+
+			if (idx < s_idx)
+				goto skip;
+
+			nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid,
+					cb->nlh->nlmsg_seq, RTM_GETMDB,
+					sizeof(*bpm), NLM_F_MULTI);
+			if (nlh == NULL)
+				break;
+
+			bpm = nlmsg_data(nlh);
+			bpm->ifindex = dev->ifindex;
+			if (br_mdb_fill_info(skb, cb, dev) < 0)
+				goto out;
+			if (br_rports_fill_info(skb, cb, dev) < 0)
+				goto out;
+
+			cb->args[1] = 0;
+			nlmsg_end(skb, nlh);
+		skip:
+			idx++;
+		}
+	}
+
+out:
+	if (nlh)
+		nlmsg_end(skb, nlh);
+	rcu_read_unlock();
+	cb->args[0] = idx;
+	return skb->len;
+}
+
+static int nlmsg_populate_mdb_fill(struct sk_buff *skb,
+				   struct net_device *dev,
+				   struct br_mdb_entry *entry, u32 pid,
+				   u32 seq, int type, unsigned int flags)
+{
+	struct nlmsghdr *nlh;
+	struct br_port_msg *bpm;
+	struct nlattr *nest, *nest2;
+
+	nlh = nlmsg_put(skb, pid, seq, type, sizeof(*bpm), NLM_F_MULTI);
+	if (!nlh)
+		return -EMSGSIZE;
+
+	bpm = nlmsg_data(nlh);
+	bpm->family  = AF_BRIDGE;
+	bpm->ifindex = dev->ifindex;
+	nest = nla_nest_start(skb, MDBA_MDB);
+	if (nest == NULL)
+		goto cancel;
+	nest2 = nla_nest_start(skb, MDBA_MDB_ENTRY);
+	if (nest2 == NULL)
+		goto end;
+
+	if (nla_put(skb, MDBA_MDB_ENTRY_INFO, sizeof(*entry), entry))
+		goto end;
+
+	nla_nest_end(skb, nest2);
+	nla_nest_end(skb, nest);
+	return nlmsg_end(skb, nlh);
+
+end:
+	nla_nest_end(skb, nest);
+cancel:
+	nlmsg_cancel(skb, nlh);
+	return -EMSGSIZE;
+}
+
+static inline size_t rtnl_mdb_nlmsg_size(void)
+{
+	return NLMSG_ALIGN(sizeof(struct br_port_msg))
+		+ nla_total_size(sizeof(struct br_mdb_entry));
+}
+
+static void __br_mdb_notify(struct net_device *dev, struct br_mdb_entry *entry,
+			    int type)
+{
+	struct net *net = dev_net(dev);
+	struct sk_buff *skb;
+	int err = -ENOBUFS;
+
+	skb = nlmsg_new(rtnl_mdb_nlmsg_size(), GFP_ATOMIC);
+	if (!skb)
+		goto errout;
+
+	err = nlmsg_populate_mdb_fill(skb, dev, entry, 0, 0, type, NTF_SELF);
+	if (err < 0) {
+		kfree_skb(skb);
+		goto errout;
+	}
+
+	rtnl_notify(skb, net, 0, RTNLGRP_MDB, NULL, GFP_ATOMIC);
+	return;
+errout:
+	rtnl_set_sk_err(net, RTNLGRP_MDB, err);
+}
+
+void br_mdb_notify(struct net_device *dev, struct net_bridge_port *port,
+		   struct br_ip *group, int type)
+{
+	struct br_mdb_entry entry;
+
+	entry.ifindex = port->dev->ifindex;
+	entry.addr.proto = group->proto;
+	entry.addr.u.ip4 = group->u.ip4;
+#if IS_ENABLED(CONFIG_IPV6)
+	entry.addr.u.ip6 = group->u.ip6;
+#endif
+	__br_mdb_notify(dev, &entry, type);
+}
+
+static bool is_valid_mdb_entry(struct br_mdb_entry *entry)
+{
+	if (entry->ifindex == 0)
+		return false;
+
+	if (entry->addr.proto == htons(ETH_P_IP)) {
+		if (!ipv4_is_multicast(entry->addr.u.ip4))
+			return false;
+		if (ipv4_is_local_multicast(entry->addr.u.ip4))
+			return false;
+#if IS_ENABLED(CONFIG_IPV6)
+	} else if (entry->addr.proto == htons(ETH_P_IPV6)) {
+		if (!ipv6_is_transient_multicast(&entry->addr.u.ip6))
+			return false;
+#endif
+	} else
+		return false;
+
+	return true;
+}
+
+static int br_mdb_parse(struct sk_buff *skb, struct nlmsghdr *nlh,
+			struct net_device **pdev, struct br_mdb_entry **pentry)
+{
+	struct net *net = sock_net(skb->sk);
+	struct br_mdb_entry *entry;
+	struct br_port_msg *bpm;
+	struct nlattr *tb[MDBA_SET_ENTRY_MAX+1];
+	struct net_device *dev;
+	int err;
+
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
+	err = nlmsg_parse(nlh, sizeof(*bpm), tb, MDBA_SET_ENTRY, NULL);
+	if (err < 0)
+		return err;
+
+	bpm = nlmsg_data(nlh);
+	if (bpm->ifindex == 0) {
+		pr_info("PF_BRIDGE: br_mdb_parse() with invalid ifindex\n");
+		return -EINVAL;
+	}
+
+	dev = __dev_get_by_index(net, bpm->ifindex);
+	if (dev == NULL) {
+		pr_info("PF_BRIDGE: br_mdb_parse() with unknown ifindex\n");
+		return -ENODEV;
+	}
+
+	if (!(dev->priv_flags & IFF_EBRIDGE)) {
+		pr_info("PF_BRIDGE: br_mdb_parse() with non-bridge\n");
+		return -EOPNOTSUPP;
+	}
+
+	*pdev = dev;
+
+	if (!tb[MDBA_SET_ENTRY] ||
+	    nla_len(tb[MDBA_SET_ENTRY]) != sizeof(struct br_mdb_entry)) {
+		pr_info("PF_BRIDGE: br_mdb_parse() with invalid attr\n");
+		return -EINVAL;
+	}
+
+	entry = nla_data(tb[MDBA_SET_ENTRY]);
+	if (!is_valid_mdb_entry(entry)) {
+		pr_info("PF_BRIDGE: br_mdb_parse() with invalid entry\n");
+		return -EINVAL;
+	}
+
+	*pentry = entry;
+	return 0;
+}
+
+static int br_mdb_add_group(struct net_bridge *br, struct net_bridge_port *port,
+			    struct br_ip *group)
+{
+	struct net_bridge_mdb_entry *mp;
+	struct net_bridge_port_group *p;
+	struct net_bridge_port_group __rcu **pp;
+	struct net_bridge_mdb_htable *mdb;
+	int err;
+
+	mdb = mlock_dereference(br->mdb, br);
+	mp = br_mdb_ip_get(mdb, group);
+	if (!mp) {
+		mp = br_multicast_new_group(br, port, group);
+		err = PTR_ERR(mp);
+		if (IS_ERR(mp))
+			return err;
+	}
+
+	for (pp = &mp->ports;
+	     (p = mlock_dereference(*pp, br)) != NULL;
+	     pp = &p->next) {
+		if (p->port == port)
+			return -EEXIST;
+		if ((unsigned long)p->port < (unsigned long)port)
+			break;
+	}
+
+	p = br_multicast_new_port_group(port, group, *pp);
+	if (unlikely(!p))
+		return -ENOMEM;
+	rcu_assign_pointer(*pp, p);
+
+	br_mdb_notify(br->dev, port, group, RTM_NEWMDB);
+	return 0;
+}
+
+static int __br_mdb_add(struct net *net, struct net_bridge *br,
+			struct br_mdb_entry *entry)
+{
+	struct br_ip ip;
+	struct net_device *dev;
+	struct net_bridge_port *p;
+	int ret;
+
+	if (!netif_running(br->dev) || br->multicast_disabled)
+		return -EINVAL;
+
+	dev = __dev_get_by_index(net, entry->ifindex);
+	if (!dev)
+		return -ENODEV;
+
+	p = br_port_get_rtnl(dev);
+	if (!p || p->br != br || p->state == BR_STATE_DISABLED)
+		return -EINVAL;
+
+	ip.proto = entry->addr.proto;
+	if (ip.proto == htons(ETH_P_IP))
+		ip.u.ip4 = entry->addr.u.ip4;
+#if IS_ENABLED(CONFIG_IPV6)
+	else
+		ip.u.ip6 = entry->addr.u.ip6;
+#endif
+
+	spin_lock_bh(&br->multicast_lock);
+	ret = br_mdb_add_group(br, p, &ip);
+	spin_unlock_bh(&br->multicast_lock);
+	return ret;
+}
+
+static int br_mdb_add(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
+{
+	struct net *net = sock_net(skb->sk);
+	struct br_mdb_entry *entry;
+	struct net_device *dev;
+	struct net_bridge *br;
+	int err;
+
+	err = br_mdb_parse(skb, nlh, &dev, &entry);
+	if (err < 0)
+		return err;
+
+	br = netdev_priv(dev);
+
+	err = __br_mdb_add(net, br, entry);
+	if (!err)
+		__br_mdb_notify(dev, entry, RTM_NEWMDB);
+	return err;
+}
+
+static int __br_mdb_del(struct net_bridge *br, struct br_mdb_entry *entry)
+{
+	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;
+	struct br_ip ip;
+	int err = -EINVAL;
+
+	if (!netif_running(br->dev) || br->multicast_disabled)
+		return -EINVAL;
+
+	if (timer_pending(&br->multicast_querier_timer))
+		return -EBUSY;
+
+	ip.proto = entry->addr.proto;
+	if (ip.proto == htons(ETH_P_IP))
+		ip.u.ip4 = entry->addr.u.ip4;
+#if IS_ENABLED(CONFIG_IPV6)
+	else
+		ip.u.ip6 = entry->addr.u.ip6;
+#endif
+
+	spin_lock_bh(&br->multicast_lock);
+	mdb = mlock_dereference(br->mdb, br);
+
+	mp = br_mdb_ip_get(mdb, &ip);
+	if (!mp)
+		goto unlock;
+
+	for (pp = &mp->ports;
+	     (p = mlock_dereference(*pp, br)) != NULL;
+	     pp = &p->next) {
+		if (!p->port || p->port->dev->ifindex != entry->ifindex)
+			continue;
+
+		if (p->port->state == BR_STATE_DISABLED)
+			goto unlock;
+
+		rcu_assign_pointer(*pp, p->next);
+		hlist_del_init(&p->mglist);
+		del_timer(&p->timer);
+		call_rcu_bh(&p->rcu, br_multicast_free_pg);
+		err = 0;
+
+		if (!mp->ports && !mp->mglist &&
+		    netif_running(br->dev))
+			mod_timer(&mp->timer, jiffies);
+		break;
+	}
+
+unlock:
+	spin_unlock_bh(&br->multicast_lock);
+	return err;
+}
+
+static int br_mdb_del(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
+{
+	struct net_device *dev;
+	struct br_mdb_entry *entry;
+	struct net_bridge *br;
+	int err;
+
+	err = br_mdb_parse(skb, nlh, &dev, &entry);
+	if (err < 0)
+		return err;
+
+	br = netdev_priv(dev);
+
+	err = __br_mdb_del(br, entry);
+	if (!err)
+		__br_mdb_notify(dev, entry, RTM_DELMDB);
+	return err;
+}
+
+void br_mdb_init(void)
+{
+	rtnl_register(PF_BRIDGE, RTM_GETMDB, NULL, br_mdb_dump, NULL);
+	rtnl_register(PF_BRIDGE, RTM_NEWMDB, br_mdb_add, NULL, NULL);
+	rtnl_register(PF_BRIDGE, RTM_DELMDB, br_mdb_del, NULL, NULL);
+}