/*
   *	Bridge netlink control interface
   *
   *	Authors:
   *	Stephen Hemminger		<shemminger@osdl.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/kernel.h>

  #include <linux/slab.h>

  #include <linux/etherdevice.h>

  #include <net/rtnetlink.h>

  #include <net/net_namespace.h>

  #include <net/sock.h>

  #include "br_private.h"

  #include "br_private_stp.h"

  static inline size_t br_nlmsg_size(void)
  {
  	return NLMSG_ALIGN(sizeof(struct ifinfomsg))
  	       + nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */
  	       + nla_total_size(MAX_ADDR_LEN) /* IFLA_ADDRESS */
  	       + nla_total_size(4) /* IFLA_MASTER */
  	       + nla_total_size(4) /* IFLA_MTU */
  	       + nla_total_size(4) /* IFLA_LINK */
  	       + nla_total_size(1) /* IFLA_OPERSTATE */
  	       + nla_total_size(1); /* IFLA_PROTINFO */
  }

  /*
   * Create one netlink message for one interface
   * Contains port and master info as well as carrier and bridge state.
   */
  static int br_fill_ifinfo(struct sk_buff *skb, const struct net_bridge_port *port,
  			  u32 pid, u32 seq, int event, unsigned int flags)
  {
  	const struct net_bridge *br = port->br;
  	const struct net_device *dev = port->dev;

  	struct ifinfomsg *hdr;

  	struct nlmsghdr *nlh;

  	u8 operstate = netif_running(dev) ? dev->operstate : IF_OPER_DOWN;

  	br_debug(br, "br_fill_info event %d port %s master %s
  ",
  		     event, dev->name, br->dev->name);

  	nlh = nlmsg_put(skb, pid, seq, event, sizeof(*hdr), flags);
  	if (nlh == NULL)

  		return -EMSGSIZE;

  	hdr = nlmsg_data(nlh);
  	hdr->ifi_family = AF_BRIDGE;
  	hdr->__ifi_pad = 0;
  	hdr->ifi_type = dev->type;
  	hdr->ifi_index = dev->ifindex;
  	hdr->ifi_flags = dev_get_flags(dev);
  	hdr->ifi_change = 0;

  	NLA_PUT_STRING(skb, IFLA_IFNAME, dev->name);
  	NLA_PUT_U32(skb, IFLA_MASTER, br->dev->ifindex);
  	NLA_PUT_U32(skb, IFLA_MTU, dev->mtu);
  	NLA_PUT_U8(skb, IFLA_OPERSTATE, operstate);

  
  	if (dev->addr_len)

  		NLA_PUT(skb, IFLA_ADDRESS, dev->addr_len, dev->dev_addr);

  	if (dev->ifindex != dev->iflink)

  		NLA_PUT_U32(skb, IFLA_LINK, dev->iflink);

  
  	if (event == RTM_NEWLINK)

  		NLA_PUT_U8(skb, IFLA_PROTINFO, port->state);

  	return nlmsg_end(skb, nlh);

  nla_put_failure:

  	nlmsg_cancel(skb, nlh);
  	return -EMSGSIZE;

  }
  
  /*
   * Notify listeners of a change in port information
   */
  void br_ifinfo_notify(int event, struct net_bridge_port *port)
  {

  	struct net *net = dev_net(port->dev);

  	struct sk_buff *skb;

  	int err = -ENOBUFS;

  	br_debug(port->br, "port %u(%s) event %d
  ",
  		 (unsigned)port->port_no, port->dev->name, event);

  	skb = nlmsg_new(br_nlmsg_size(), GFP_ATOMIC);

  	if (skb == NULL)
  		goto errout;
  
  	err = br_fill_ifinfo(skb, port, 0, 0, event, 0);

  	if (err < 0) {
  		/* -EMSGSIZE implies BUG in br_nlmsg_size() */
  		WARN_ON(err == -EMSGSIZE);
  		kfree_skb(skb);
  		goto errout;
  	}

  	rtnl_notify(skb, net, 0, RTNLGRP_LINK, NULL, GFP_ATOMIC);
  	return;

  errout:

  	if (err < 0)

  		rtnl_set_sk_err(net, RTNLGRP_LINK, err);

  }
  
  /*
   * Dump information about all ports, in response to GETLINK
   */
  static int br_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
  {

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

  	struct net_device *dev;
  	int idx;

  	idx = 0;

  	rcu_read_lock();
  	for_each_netdev_rcu(net, dev) {
  		struct net_bridge_port *port = br_port_get_rcu(dev);

  		/* not a bridge port */

  		if (!port || idx < cb->args[0])

  			goto skip;

  		if (br_fill_ifinfo(skb, port,

  				   NETLINK_CB(cb->skb).pid,

  				   cb->nlh->nlmsg_seq, RTM_NEWLINK,
  				   NLM_F_MULTI) < 0)

  			break;

  skip:

  		++idx;
  	}

  	rcu_read_unlock();

  	cb->args[0] = idx;
  
  	return skb->len;
  }
  
  /*
   * Change state of port (ie from forwarding to blocking etc)
   * Used by spanning tree in user space.
   */
  static int br_rtm_setlink(struct sk_buff *skb,  struct nlmsghdr *nlh, void *arg)
  {

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

  	struct ifinfomsg *ifm;
  	struct nlattr *protinfo;

  	struct net_device *dev;
  	struct net_bridge_port *p;
  	u8 new_state;

  	if (nlmsg_len(nlh) < sizeof(*ifm))
  		return -EINVAL;
  
  	ifm = nlmsg_data(nlh);

  	if (ifm->ifi_family != AF_BRIDGE)
  		return -EPFNOSUPPORT;

  	protinfo = nlmsg_find_attr(nlh, sizeof(*ifm), IFLA_PROTINFO);
  	if (!protinfo || nla_len(protinfo) < sizeof(u8))

  		return -EINVAL;

  	new_state = nla_get_u8(protinfo);

  	if (new_state > BR_STATE_BLOCKING)
  		return -EINVAL;

  	dev = __dev_get_by_index(net, ifm->ifi_index);

  	if (!dev)
  		return -ENODEV;

  	p = br_port_get_rtnl(dev);

  	if (!p)
  		return -EINVAL;

  
  	/* if kernel STP is running, don't allow changes */

  	if (p->br->stp_enabled == BR_KERNEL_STP)

  		return -EBUSY;

  	if (!netif_running(dev) ||
  	    (!netif_carrier_ok(dev) && new_state != BR_STATE_DISABLED))

  		return -ENETDOWN;
  
  	p->state = new_state;
  	br_log_state(p);

  
  	spin_lock_bh(&p->br->lock);
  	br_port_state_selection(p->br);
  	spin_unlock_bh(&p->br->lock);

  	br_ifinfo_notify(RTM_NEWLINK, p);

  	return 0;
  }

  static int br_validate(struct nlattr *tb[], struct nlattr *data[])
  {
  	if (tb[IFLA_ADDRESS]) {
  		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
  			return -EINVAL;
  		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
  			return -EADDRNOTAVAIL;
  	}
  
  	return 0;
  }
  
  static struct rtnl_link_ops br_link_ops __read_mostly = {
  	.kind		= "bridge",
  	.priv_size	= sizeof(struct net_bridge),
  	.setup		= br_dev_setup,
  	.validate	= br_validate,

  	.dellink	= br_dev_delete,

  };

  int __init br_netlink_init(void)

  {

  	int err;

  	err = rtnl_link_register(&br_link_ops);
  	if (err < 0)
  		goto err1;

  	err = __rtnl_register(PF_BRIDGE, RTM_GETLINK, NULL,
  			      br_dump_ifinfo, NULL);

  	if (err)
  		goto err2;

  	err = __rtnl_register(PF_BRIDGE, RTM_SETLINK,
  			      br_rtm_setlink, NULL, NULL);

  	if (err)
  		goto err3;

  	err = __rtnl_register(PF_BRIDGE, RTM_NEWNEIGH,
  			      br_fdb_add, NULL, NULL);

  	if (err)
  		goto err3;

  	err = __rtnl_register(PF_BRIDGE, RTM_DELNEIGH,
  			      br_fdb_delete, NULL, NULL);

  	if (err)
  		goto err3;

  	err = __rtnl_register(PF_BRIDGE, RTM_GETNEIGH,
  			      NULL, br_fdb_dump, NULL);

  	if (err)
  		goto err3;

  
  	return 0;

  
  err3:
  	rtnl_unregister_all(PF_BRIDGE);
  err2:
  	rtnl_link_unregister(&br_link_ops);
  err1:
  	return err;

  }
  
  void __exit br_netlink_fini(void)
  {

  	rtnl_link_unregister(&br_link_ops);

  	rtnl_unregister_all(PF_BRIDGE);

  }