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Commit 36fd2b63 authored by stephen hemminger's avatar stephen hemminger Committed by David S. Miller
Browse files

bridge: allow creating/deleting fdb entries via netlink 



Use RTM_NEWNEIGH and RTM_DELNEIGH to allow updating of entries
in bridge forwarding table. This allows manipulating static entries
which is not possible with existing tools.

Example (using bridge extensions to iproute2)
   # br fdb add 00:02:03:04:05:06 dev eth0

Signed-off-by: default avatarStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent b078f0df

net/bridge/br_fdb.c

+139 −0
Original line number Diff line number Diff line
@@ -555,3 +555,142 @@ skip: 


	return skb->len;

}



/* Create new static fdb entry */

static int fdb_add_entry(struct net_bridge_port *source, const __u8 *addr,

			 __u16 state)

{

	struct net_bridge *br = source->br;

	struct hlist_head *head = &br->hash[br_mac_hash(addr)];

	struct net_bridge_fdb_entry *fdb;



	fdb = fdb_find(head, addr);

	if (fdb)

		return -EEXIST;



	fdb = fdb_create(head, source, addr);

	if (!fdb)

		return -ENOMEM;



	if (state & NUD_PERMANENT)

		fdb->is_local = fdb->is_static = 1;

	else if (state & NUD_NOARP)

		fdb->is_static = 1;

	return 0;

}



/* Add new permanent fdb entry with RTM_NEWNEIGH */

int br_fdb_add(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)

{

	struct net *net = sock_net(skb->sk);

	struct ndmsg *ndm;

	struct nlattr *tb[NDA_MAX+1];

	struct net_device *dev;

	struct net_bridge_port *p;

	const __u8 *addr;

	int err;



	ASSERT_RTNL();

	err = nlmsg_parse(nlh, sizeof(*ndm), tb, NDA_MAX, NULL);

	if (err < 0)

		return err;



	ndm = nlmsg_data(nlh);

	if (ndm->ndm_ifindex == 0) {

		pr_info("bridge: RTM_NEWNEIGH with invalid ifindex\n");

		return -EINVAL;

	}



	dev = __dev_get_by_index(net, ndm->ndm_ifindex);

	if (dev == NULL) {

		pr_info("bridge: RTM_NEWNEIGH with unknown ifindex\n");

		return -ENODEV;

	}



	if (!tb[NDA_LLADDR] || nla_len(tb[NDA_LLADDR]) != ETH_ALEN) {

		pr_info("bridge: RTM_NEWNEIGH with invalid address\n");

		return -EINVAL;

	}



	addr = nla_data(tb[NDA_LLADDR]);

	if (!is_valid_ether_addr(addr)) {

		pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n");

		return -EINVAL;

	}



	p = br_port_get_rtnl(dev);

	if (p == NULL) {

		pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",

			dev->name);

		return -EINVAL;

	}



	spin_lock_bh(&p->br->hash_lock);

	err = fdb_add_entry(p, addr, ndm->ndm_state);

	spin_unlock_bh(&p->br->hash_lock);



	return err;

}



static int fdb_delete_by_addr(struct net_bridge_port *p, const u8 *addr)

{

	struct net_bridge *br = p->br;

	struct hlist_head *head = &br->hash[br_mac_hash(addr)];

	struct net_bridge_fdb_entry *fdb;



	fdb = fdb_find(head, addr);

	if (!fdb)

		return -ENOENT;



	fdb_delete(fdb);

	return 0;

}



/* Remove neighbor entry with RTM_DELNEIGH */

int br_fdb_delete(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)

{

	struct net *net = sock_net(skb->sk);

	struct ndmsg *ndm;

	struct net_bridge_port *p;

	struct nlattr *llattr;

	const __u8 *addr;

	struct net_device *dev;

	int err;



	ASSERT_RTNL();

	if (nlmsg_len(nlh) < sizeof(*ndm))

		return -EINVAL;



	ndm = nlmsg_data(nlh);

	if (ndm->ndm_ifindex == 0) {

		pr_info("bridge: RTM_DELNEIGH with invalid ifindex\n");

		return -EINVAL;

	}



	dev = __dev_get_by_index(net, ndm->ndm_ifindex);

	if (dev == NULL) {

		pr_info("bridge: RTM_DELNEIGH with unknown ifindex\n");

		return -ENODEV;

	}



	llattr = nlmsg_find_attr(nlh, sizeof(*ndm), NDA_LLADDR);

	if (llattr == NULL || nla_len(llattr) != ETH_ALEN) {

		pr_info("bridge: RTM_DELNEIGH with invalid address\n");

		return -EINVAL;

	}



	addr = nla_data(llattr);



	p = br_port_get_rtnl(dev);

	if (p == NULL) {

		pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",

			dev->name);

		return -EINVAL;

	}



	spin_lock_bh(&p->br->hash_lock);

	err = fdb_delete_by_addr(p, addr);

	spin_unlock_bh(&p->br->hash_lock);



	return err;

}

net/bridge/br_netlink.c

+3 −0
Original line number Diff line number Diff line
@@ -196,6 +196,9 @@ int __init br_netlink_init(void) 


	/* Only the first call to __rtnl_register can fail */

	__rtnl_register(PF_BRIDGE, RTM_SETLINK, br_rtm_setlink, NULL);



	__rtnl_register(PF_BRIDGE, RTM_NEWNEIGH, br_fdb_add, NULL);

	__rtnl_register(PF_BRIDGE, RTM_DELNEIGH, br_fdb_delete, NULL);

	__rtnl_register(PF_BRIDGE, RTM_GETNEIGH, NULL, br_fdb_dump);



	return 0;

net/bridge/br_private.h

+2 −0
Original line number Diff line number Diff line
@@ -355,6 +355,8 @@ extern void br_fdb_update(struct net_bridge *br, 
			  struct net_bridge_port *source,

			  const unsigned char *addr);

extern int br_fdb_dump(struct sk_buff *skb, struct netlink_callback *cb);

extern int br_fdb_add(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg);

extern int br_fdb_delete(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg);



/* br_forward.c */

extern void br_deliver(const struct net_bridge_port *to,