/*
   * DECnet       An implementation of the DECnet protocol suite for the LINUX
   *              operating system.  DECnet is implemented using the  BSD Socket
   *              interface as the means of communication with the user level.
   *
   *              DECnet Device Layer
   *
   * Authors:     Steve Whitehouse <SteveW@ACM.org>
   *              Eduardo Marcelo Serrat <emserrat@geocities.com>
   *
   * Changes:
   *          Steve Whitehouse : Devices now see incoming frames so they
   *                             can mark on who it came from.
   *          Steve Whitehouse : Fixed bug in creating neighbours. Each neighbour
   *                             can now have a device specific setup func.
   *          Steve Whitehouse : Added /proc/sys/net/decnet/conf/<dev>/
   *          Steve Whitehouse : Fixed bug which sometimes killed timer
   *          Steve Whitehouse : Multiple ifaddr support
   *          Steve Whitehouse : SIOCGIFCONF is now a compile time option
   *          Steve Whitehouse : /proc/sys/net/decnet/conf/<sys>/forwarding
   *          Steve Whitehouse : Removed timer1 - it's a user space issue now
   *         Patrick Caulfield : Fixed router hello message format
   *          Steve Whitehouse : Got rid of constant sizes for blksize for
   *                             devices. All mtu based now.
   */

  #include <linux/capability.h>

  #include <linux/module.h>
  #include <linux/moduleparam.h>
  #include <linux/init.h>
  #include <linux/net.h>
  #include <linux/netdevice.h>
  #include <linux/proc_fs.h>
  #include <linux/seq_file.h>
  #include <linux/timer.h>
  #include <linux/string.h>

  #include <linux/if_addr.h>

  #include <linux/if_arp.h>
  #include <linux/if_ether.h>
  #include <linux/skbuff.h>

  #include <linux/sysctl.h>
  #include <linux/notifier.h>

  #include <linux/slab.h>

  #include <asm/uaccess.h>
  #include <asm/system.h>

  #include <net/net_namespace.h>

  #include <net/neighbour.h>
  #include <net/dst.h>
  #include <net/flow.h>

  #include <net/fib_rules.h>

  #include <net/netlink.h>

  #include <net/dn.h>
  #include <net/dn_dev.h>
  #include <net/dn_route.h>
  #include <net/dn_neigh.h>
  #include <net/dn_fib.h>
  
  #define DN_IFREQ_SIZE (sizeof(struct ifreq) - sizeof(struct sockaddr) + sizeof(struct sockaddr_dn))
  
  static char dn_rt_all_end_mcast[ETH_ALEN] = {0xAB,0x00,0x00,0x04,0x00,0x00};
  static char dn_rt_all_rt_mcast[ETH_ALEN]  = {0xAB,0x00,0x00,0x03,0x00,0x00};
  static char dn_hiord[ETH_ALEN]            = {0xAA,0x00,0x04,0x00,0x00,0x00};
  static unsigned char dn_eco_version[3]    = {0x02,0x00,0x00};
  
  extern struct neigh_table dn_neigh_table;
  
  /*
   * decnet_address is kept in network order.
   */

  __le16 decnet_address = 0;

  static DEFINE_SPINLOCK(dndev_lock);

  static struct net_device *decnet_default_device;

  static BLOCKING_NOTIFIER_HEAD(dnaddr_chain);

  
  static struct dn_dev *dn_dev_create(struct net_device *dev, int *err);
  static void dn_dev_delete(struct net_device *dev);

  static void dn_ifaddr_notify(int event, struct dn_ifaddr *ifa);

  
  static int dn_eth_up(struct net_device *);
  static void dn_eth_down(struct net_device *);
  static void dn_send_brd_hello(struct net_device *dev, struct dn_ifaddr *ifa);
  static void dn_send_ptp_hello(struct net_device *dev, struct dn_ifaddr *ifa);
  
  static struct dn_dev_parms dn_dev_list[] =  {
  {
  	.type =		ARPHRD_ETHER, /* Ethernet */
  	.mode =		DN_DEV_BCAST,
  	.state =	DN_DEV_S_RU,
  	.t2 =		1,
  	.t3 =		10,
  	.name =		"ethernet",

  	.up =		dn_eth_up,
  	.down = 	dn_eth_down,
  	.timer3 =	dn_send_brd_hello,
  },
  {
  	.type =		ARPHRD_IPGRE, /* DECnet tunneled over GRE in IP */
  	.mode =		DN_DEV_BCAST,
  	.state =	DN_DEV_S_RU,
  	.t2 =		1,
  	.t3 =		10,
  	.name =		"ipgre",

  	.timer3 =	dn_send_brd_hello,
  },
  #if 0
  {
  	.type =		ARPHRD_X25, /* Bog standard X.25 */
  	.mode =		DN_DEV_UCAST,
  	.state =	DN_DEV_S_DS,
  	.t2 =		1,
  	.t3 =		120,
  	.name =		"x25",

  	.timer3 =	dn_send_ptp_hello,
  },
  #endif
  #if 0
  {
  	.type =		ARPHRD_PPP, /* DECnet over PPP */
  	.mode =		DN_DEV_BCAST,
  	.state =	DN_DEV_S_RU,
  	.t2 =		1,
  	.t3 =		10,
  	.name =		"ppp",

  	.timer3 =	dn_send_brd_hello,
  },
  #endif
  {
  	.type =		ARPHRD_DDCMP, /* DECnet over DDCMP */
  	.mode =		DN_DEV_UCAST,
  	.state =	DN_DEV_S_DS,
  	.t2 =		1,
  	.t3 =		120,
  	.name =		"ddcmp",

  	.timer3 =	dn_send_ptp_hello,
  },
  {
  	.type =		ARPHRD_LOOPBACK, /* Loopback interface - always last */
  	.mode =		DN_DEV_BCAST,
  	.state =	DN_DEV_S_RU,
  	.t2 =		1,
  	.t3 =		10,
  	.name =		"loopback",

  	.timer3 =	dn_send_brd_hello,
  }
  };

  #define DN_DEV_LIST_SIZE ARRAY_SIZE(dn_dev_list)

  #define DN_DEV_PARMS_OFFSET(x) offsetof(struct dn_dev_parms, x)

  
  #ifdef CONFIG_SYSCTL
  
  static int min_t2[] = { 1 };
  static int max_t2[] = { 60 }; /* No max specified, but this seems sensible */
  static int min_t3[] = { 1 };
  static int max_t3[] = { 8191 }; /* Must fit in 16 bits when multiplied by BCT3MULT or T3MULT */
  
  static int min_priority[1];
  static int max_priority[] = { 127 }; /* From DECnet spec */

  static int dn_forwarding_proc(ctl_table *, int,

  			void __user *, size_t *, loff_t *);

  static struct dn_dev_sysctl_table {
  	struct ctl_table_header *sysctl_header;
  	ctl_table dn_dev_vars[5];

  } dn_dev_sysctl = {
  	NULL,
  	{
  	{

  		.procname = "forwarding",
  		.data = (void *)DN_DEV_PARMS_OFFSET(forwarding),
  		.maxlen = sizeof(int),
  		.mode = 0644,
  		.proc_handler = dn_forwarding_proc,

  	},
  	{

  		.procname = "priority",
  		.data = (void *)DN_DEV_PARMS_OFFSET(priority),
  		.maxlen = sizeof(int),
  		.mode = 0644,
  		.proc_handler = proc_dointvec_minmax,

  		.extra1 = &min_priority,
  		.extra2 = &max_priority
  	},
  	{

  		.procname = "t2",
  		.data = (void *)DN_DEV_PARMS_OFFSET(t2),
  		.maxlen = sizeof(int),
  		.mode = 0644,
  		.proc_handler = proc_dointvec_minmax,

  		.extra1 = &min_t2,
  		.extra2 = &max_t2
  	},
  	{

  		.procname = "t3",
  		.data = (void *)DN_DEV_PARMS_OFFSET(t3),
  		.maxlen = sizeof(int),
  		.mode = 0644,
  		.proc_handler = proc_dointvec_minmax,

  		.extra1 = &min_t3,
  		.extra2 = &max_t3
  	},
  	{0}
  	},

  };
  
  static void dn_dev_sysctl_register(struct net_device *dev, struct dn_dev_parms *parms)
  {
  	struct dn_dev_sysctl_table *t;
  	int i;

  #define DN_CTL_PATH_DEV	3
  
  	struct ctl_path dn_ctl_path[] = {

  		{ .procname = "net",  },
  		{ .procname = "decnet",  },
  		{ .procname = "conf",  },

  		{ /* to be set */ },
  		{ },
  	};

  	t = kmemdup(&dn_dev_sysctl, sizeof(*t), GFP_KERNEL);

  	if (t == NULL)
  		return;

  	for(i = 0; i < ARRAY_SIZE(t->dn_dev_vars) - 1; i++) {
  		long offset = (long)t->dn_dev_vars[i].data;
  		t->dn_dev_vars[i].data = ((char *)parms) + offset;

  	}
  
  	if (dev) {

  		dn_ctl_path[DN_CTL_PATH_DEV].procname = dev->name;

  	} else {

  		dn_ctl_path[DN_CTL_PATH_DEV].procname = parms->name;

  	}

  	t->dn_dev_vars[0].extra1 = (void *)dev;

  	t->sysctl_header = register_sysctl_paths(dn_ctl_path, t->dn_dev_vars);

  	if (t->sysctl_header == NULL)
  		kfree(t);
  	else
  		parms->sysctl = t;
  }
  
  static void dn_dev_sysctl_unregister(struct dn_dev_parms *parms)
  {
  	if (parms->sysctl) {
  		struct dn_dev_sysctl_table *t = parms->sysctl;
  		parms->sysctl = NULL;
  		unregister_sysctl_table(t->sysctl_header);
  		kfree(t);
  	}
  }

  static int dn_forwarding_proc(ctl_table *table, int write,

  				void __user *buffer,
  				size_t *lenp, loff_t *ppos)
  {
  #ifdef CONFIG_DECNET_ROUTER
  	struct net_device *dev = table->extra1;
  	struct dn_dev *dn_db;
  	int err;
  	int tmp, old;
  
  	if (table->extra1 == NULL)
  		return -EINVAL;

  	dn_db = rcu_dereference_raw(dev->dn_ptr);

  	old = dn_db->parms.forwarding;

  	err = proc_dointvec(table, write, buffer, lenp, ppos);

  
  	if ((err >= 0) && write) {
  		if (dn_db->parms.forwarding < 0)
  			dn_db->parms.forwarding = 0;
  		if (dn_db->parms.forwarding > 2)
  			dn_db->parms.forwarding = 2;
  		/*
  		 * What an ugly hack this is... its works, just. It
  		 * would be nice if sysctl/proc were just that little
  		 * bit more flexible so I don't have to write a special
  		 * routine, or suffer hacks like this - SJW
  		 */
  		tmp = dn_db->parms.forwarding;
  		dn_db->parms.forwarding = old;
  		if (dn_db->parms.down)
  			dn_db->parms.down(dev);
  		dn_db->parms.forwarding = tmp;
  		if (dn_db->parms.up)
  			dn_db->parms.up(dev);
  	}
  
  	return err;
  #else
  	return -EINVAL;
  #endif
  }

  #else /* CONFIG_SYSCTL */
  static void dn_dev_sysctl_unregister(struct dn_dev_parms *parms)
  {
  }
  static void dn_dev_sysctl_register(struct net_device *dev, struct dn_dev_parms *parms)
  {
  }
  
  #endif /* CONFIG_SYSCTL */
  
  static inline __u16 mtu2blksize(struct net_device *dev)
  {
  	u32 blksize = dev->mtu;
  	if (blksize > 0xffff)
  		blksize = 0xffff;
  
  	if (dev->type == ARPHRD_ETHER ||
  	    dev->type == ARPHRD_PPP ||
  	    dev->type == ARPHRD_IPGRE ||
  	    dev->type == ARPHRD_LOOPBACK)
  		blksize -= 2;
  
  	return (__u16)blksize;
  }
  
  static struct dn_ifaddr *dn_dev_alloc_ifa(void)
  {
  	struct dn_ifaddr *ifa;

  	ifa = kzalloc(sizeof(*ifa), GFP_KERNEL);

  
  	return ifa;
  }

  static void dn_dev_free_ifa(struct dn_ifaddr *ifa)

  {

  	kfree_rcu(ifa, rcu);

  }
  
  static void dn_dev_del_ifa(struct dn_dev *dn_db, struct dn_ifaddr __rcu **ifap, int destroy)
  {
  	struct dn_ifaddr *ifa1 = rtnl_dereference(*ifap);

  	unsigned char mac_addr[6];
  	struct net_device *dev = dn_db->dev;
  
  	ASSERT_RTNL();
  
  	*ifap = ifa1->ifa_next;
  
  	if (dn_db->dev->type == ARPHRD_ETHER) {

  		if (ifa1->ifa_local != dn_eth2dn(dev->dev_addr)) {

  			dn_dn2eth(mac_addr, ifa1->ifa_local);

  			dev_mc_del(dev, mac_addr);

  		}
  	}

  	dn_ifaddr_notify(RTM_DELADDR, ifa1);

  	blocking_notifier_call_chain(&dnaddr_chain, NETDEV_DOWN, ifa1);

  	if (destroy) {
  		dn_dev_free_ifa(ifa1);
  
  		if (dn_db->ifa_list == NULL)
  			dn_dev_delete(dn_db->dev);
  	}
  }
  
  static int dn_dev_insert_ifa(struct dn_dev *dn_db, struct dn_ifaddr *ifa)
  {
  	struct net_device *dev = dn_db->dev;
  	struct dn_ifaddr *ifa1;
  	unsigned char mac_addr[6];
  
  	ASSERT_RTNL();

  	/* Check for duplicates */

  	for (ifa1 = rtnl_dereference(dn_db->ifa_list);
  	     ifa1 != NULL;
  	     ifa1 = rtnl_dereference(ifa1->ifa_next)) {

  		if (ifa1->ifa_local == ifa->ifa_local)
  			return -EEXIST;
  	}
  
  	if (dev->type == ARPHRD_ETHER) {

  		if (ifa->ifa_local != dn_eth2dn(dev->dev_addr)) {

  			dn_dn2eth(mac_addr, ifa->ifa_local);

  			dev_mc_add(dev, mac_addr);

  		}
  	}
  
  	ifa->ifa_next = dn_db->ifa_list;

  	rcu_assign_pointer(dn_db->ifa_list, ifa);

  	dn_ifaddr_notify(RTM_NEWADDR, ifa);

  	blocking_notifier_call_chain(&dnaddr_chain, NETDEV_UP, ifa);

  
  	return 0;
  }
  
  static int dn_dev_set_ifa(struct net_device *dev, struct dn_ifaddr *ifa)
  {

  	struct dn_dev *dn_db = rtnl_dereference(dev->dn_ptr);

  	int rv;
  
  	if (dn_db == NULL) {
  		int err;
  		dn_db = dn_dev_create(dev, &err);
  		if (dn_db == NULL)
  			return err;
  	}
  
  	ifa->ifa_dev = dn_db;
  
  	if (dev->flags & IFF_LOOPBACK)
  		ifa->ifa_scope = RT_SCOPE_HOST;
  
  	rv = dn_dev_insert_ifa(dn_db, ifa);
  	if (rv)
  		dn_dev_free_ifa(ifa);
  	return rv;
  }
  
  
  int dn_dev_ioctl(unsigned int cmd, void __user *arg)
  {
  	char buffer[DN_IFREQ_SIZE];
  	struct ifreq *ifr = (struct ifreq *)buffer;
  	struct sockaddr_dn *sdn = (struct sockaddr_dn *)&ifr->ifr_addr;
  	struct dn_dev *dn_db;
  	struct net_device *dev;

  	struct dn_ifaddr *ifa = NULL;
  	struct dn_ifaddr __rcu **ifap = NULL;

  	int ret = 0;
  
  	if (copy_from_user(ifr, arg, DN_IFREQ_SIZE))
  		return -EFAULT;
  	ifr->ifr_name[IFNAMSIZ-1] = 0;

  	dev_load(&init_net, ifr->ifr_name);

  	switch (cmd) {
  	case SIOCGIFADDR:
  		break;
  	case SIOCSIFADDR:
  		if (!capable(CAP_NET_ADMIN))
  			return -EACCES;
  		if (sdn->sdn_family != AF_DECnet)

  			return -EINVAL;

  		break;
  	default:
  		return -EINVAL;

  	}
  
  	rtnl_lock();

  	if ((dev = __dev_get_by_name(&init_net, ifr->ifr_name)) == NULL) {

  		ret = -ENODEV;
  		goto done;
  	}

  	if ((dn_db = rtnl_dereference(dev->dn_ptr)) != NULL) {
  		for (ifap = &dn_db->ifa_list;
  		     (ifa = rtnl_dereference(*ifap)) != NULL;
  		     ifap = &ifa->ifa_next)

  			if (strcmp(ifr->ifr_name, ifa->ifa_label) == 0)
  				break;
  	}
  
  	if (ifa == NULL && cmd != SIOCSIFADDR) {
  		ret = -EADDRNOTAVAIL;
  		goto done;
  	}

  	switch (cmd) {
  	case SIOCGIFADDR:
  		*((__le16 *)sdn->sdn_nodeaddr) = ifa->ifa_local;
  		goto rarok;
  
  	case SIOCSIFADDR:
  		if (!ifa) {
  			if ((ifa = dn_dev_alloc_ifa()) == NULL) {
  				ret = -ENOBUFS;
  				break;

  			}

  			memcpy(ifa->ifa_label, dev->name, IFNAMSIZ);
  		} else {
  			if (ifa->ifa_local == dn_saddr2dn(sdn))
  				break;
  			dn_dev_del_ifa(dn_db, ifap, 0);
  		}

  		ifa->ifa_local = ifa->ifa_address = dn_saddr2dn(sdn);

  		ret = dn_dev_set_ifa(dev, ifa);

  	}
  done:
  	rtnl_unlock();
  
  	return ret;
  rarok:
  	if (copy_to_user(arg, ifr, DN_IFREQ_SIZE))
  		ret = -EFAULT;
  	goto done;
  }
  
  struct net_device *dn_dev_get_default(void)
  {
  	struct net_device *dev;

  
  	spin_lock(&dndev_lock);

  	dev = decnet_default_device;
  	if (dev) {
  		if (dev->dn_ptr)
  			dev_hold(dev);
  		else
  			dev = NULL;
  	}

  	spin_unlock(&dndev_lock);

  	return dev;
  }
  
  int dn_dev_set_default(struct net_device *dev, int force)
  {
  	struct net_device *old = NULL;
  	int rv = -EBUSY;
  	if (!dev->dn_ptr)
  		return -ENODEV;

  
  	spin_lock(&dndev_lock);

  	if (force || decnet_default_device == NULL) {
  		old = decnet_default_device;
  		decnet_default_device = dev;
  		rv = 0;
  	}

  	spin_unlock(&dndev_lock);

  	if (old)

  		dev_put(old);

  	return rv;
  }
  
  static void dn_dev_check_default(struct net_device *dev)
  {

  	spin_lock(&dndev_lock);

  	if (dev == decnet_default_device) {
  		decnet_default_device = NULL;
  	} else {
  		dev = NULL;
  	}

  	spin_unlock(&dndev_lock);

  	if (dev)
  		dev_put(dev);
  }

  /*
   * Called with RTNL
   */

  static struct dn_dev *dn_dev_by_index(int ifindex)
  {
  	struct net_device *dev;
  	struct dn_dev *dn_dev = NULL;

  
  	dev = __dev_get_by_index(&init_net, ifindex);
  	if (dev)

  		dn_dev = rtnl_dereference(dev->dn_ptr);

  
  	return dn_dev;
  }

  static const struct nla_policy dn_ifa_policy[IFA_MAX+1] = {

  	[IFA_ADDRESS]		= { .type = NLA_U16 },
  	[IFA_LOCAL]		= { .type = NLA_U16 },
  	[IFA_LABEL]		= { .type = NLA_STRING,
  				    .len = IFNAMSIZ - 1 },
  };
  
  static int dn_nl_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)

  {

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

  	struct nlattr *tb[IFA_MAX+1];

  	struct dn_dev *dn_db;

  	struct ifaddrmsg *ifm;

  	struct dn_ifaddr *ifa;
  	struct dn_ifaddr __rcu **ifap;

  	int err = -EINVAL;

  	if (!net_eq(net, &init_net))

  		goto errout;

  
  	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, dn_ifa_policy);
  	if (err < 0)
  		goto errout;

  	err = -ENODEV;

  	ifm = nlmsg_data(nlh);

  	if ((dn_db = dn_dev_by_index(ifm->ifa_index)) == NULL)

  		goto errout;

  	err = -EADDRNOTAVAIL;

  	for (ifap = &dn_db->ifa_list;
  	     (ifa = rtnl_dereference(*ifap)) != NULL;
  	     ifap = &ifa->ifa_next) {

  		if (tb[IFA_LOCAL] &&
  		    nla_memcmp(tb[IFA_LOCAL], &ifa->ifa_local, 2))
  			continue;

  		if (tb[IFA_LABEL] && nla_strcmp(tb[IFA_LABEL], ifa->ifa_label))

  			continue;
  
  		dn_dev_del_ifa(dn_db, ifap, 1);
  		return 0;
  	}

  errout:
  	return err;

  }

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

  {

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

  	struct nlattr *tb[IFA_MAX+1];

  	struct net_device *dev;
  	struct dn_dev *dn_db;

  	struct ifaddrmsg *ifm;

  	struct dn_ifaddr *ifa;

  	int err;

  	if (!net_eq(net, &init_net))

  		return -EINVAL;

  	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, dn_ifa_policy);
  	if (err < 0)
  		return err;

  	if (tb[IFA_LOCAL] == NULL)

  		return -EINVAL;

  	ifm = nlmsg_data(nlh);

  	if ((dev = __dev_get_by_index(&init_net, ifm->ifa_index)) == NULL)

  		return -ENODEV;

  	if ((dn_db = rtnl_dereference(dev->dn_ptr)) == NULL) {

  		dn_db = dn_dev_create(dev, &err);
  		if (!dn_db)
  			return err;
  	}

  	if ((ifa = dn_dev_alloc_ifa()) == NULL)
  		return -ENOBUFS;

  	if (tb[IFA_ADDRESS] == NULL)
  		tb[IFA_ADDRESS] = tb[IFA_LOCAL];
  
  	ifa->ifa_local = nla_get_le16(tb[IFA_LOCAL]);
  	ifa->ifa_address = nla_get_le16(tb[IFA_ADDRESS]);

  	ifa->ifa_flags = ifm->ifa_flags;
  	ifa->ifa_scope = ifm->ifa_scope;
  	ifa->ifa_dev = dn_db;

  
  	if (tb[IFA_LABEL])
  		nla_strlcpy(ifa->ifa_label, tb[IFA_LABEL], IFNAMSIZ);

  	else
  		memcpy(ifa->ifa_label, dev->name, IFNAMSIZ);

  	err = dn_dev_insert_ifa(dn_db, ifa);
  	if (err)

  		dn_dev_free_ifa(ifa);

  
  	return err;

  }

  static inline size_t dn_ifaddr_nlmsg_size(void)
  {
  	return NLMSG_ALIGN(sizeof(struct ifaddrmsg))
  	       + nla_total_size(IFNAMSIZ) /* IFA_LABEL */
  	       + nla_total_size(2) /* IFA_ADDRESS */
  	       + nla_total_size(2); /* IFA_LOCAL */
  }

  static int dn_nl_fill_ifaddr(struct sk_buff *skb, struct dn_ifaddr *ifa,
  			     u32 pid, u32 seq, int event, unsigned int flags)

  {
  	struct ifaddrmsg *ifm;
  	struct nlmsghdr *nlh;

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

  		return -EMSGSIZE;

  	ifm = nlmsg_data(nlh);

  	ifm->ifa_family = AF_DECnet;
  	ifm->ifa_prefixlen = 16;
  	ifm->ifa_flags = ifa->ifa_flags | IFA_F_PERMANENT;
  	ifm->ifa_scope = ifa->ifa_scope;
  	ifm->ifa_index = ifa->ifa_dev->dev->ifindex;

  	if (ifa->ifa_address)

  		NLA_PUT_LE16(skb, IFA_ADDRESS, ifa->ifa_address);

  	if (ifa->ifa_local)

  		NLA_PUT_LE16(skb, IFA_LOCAL, ifa->ifa_local);

  	if (ifa->ifa_label[0])

  		NLA_PUT_STRING(skb, IFA_LABEL, ifa->ifa_label);

  	return nlmsg_end(skb, nlh);
  
  nla_put_failure:

  	nlmsg_cancel(skb, nlh);
  	return -EMSGSIZE;

  }

  static void dn_ifaddr_notify(int event, struct dn_ifaddr *ifa)

  {
  	struct sk_buff *skb;

  	int err = -ENOBUFS;

  	skb = alloc_skb(dn_ifaddr_nlmsg_size(), GFP_KERNEL);

  	if (skb == NULL)
  		goto errout;

  	err = dn_nl_fill_ifaddr(skb, ifa, 0, 0, event, 0);

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

  	rtnl_notify(skb, &init_net, 0, RTNLGRP_DECnet_IFADDR, NULL, GFP_KERNEL);
  	return;

  errout:
  	if (err < 0)

  		rtnl_set_sk_err(&init_net, RTNLGRP_DECnet_IFADDR, err);

  }

  static int dn_nl_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)

  {

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

  	int idx, dn_idx = 0, skip_ndevs, skip_naddr;

  	struct net_device *dev;
  	struct dn_dev *dn_db;
  	struct dn_ifaddr *ifa;

  	if (!net_eq(net, &init_net))

  		return 0;

  	skip_ndevs = cb->args[0];
  	skip_naddr = cb->args[1];

  	idx = 0;

  	rcu_read_lock();
  	for_each_netdev_rcu(&init_net, dev) {

  		if (idx < skip_ndevs)

  			goto cont;

  		else if (idx > skip_ndevs) {
  			/* Only skip over addresses for first dev dumped
  			 * in this iteration (idx == skip_ndevs) */
  			skip_naddr = 0;
  		}

  		if ((dn_db = rcu_dereference(dev->dn_ptr)) == NULL)

  			goto cont;

  		for (ifa = rcu_dereference(dn_db->ifa_list), dn_idx = 0; ifa;
  		     ifa = rcu_dereference(ifa->ifa_next), dn_idx++) {

  			if (dn_idx < skip_naddr)

  				continue;

  			if (dn_nl_fill_ifaddr(skb, ifa, NETLINK_CB(cb->skb).pid,
  					      cb->nlh->nlmsg_seq, RTM_NEWADDR,
  					      NLM_F_MULTI) < 0)

  				goto done;
  		}

  cont:
  		idx++;

  	}
  done:

  	rcu_read_unlock();

  	cb->args[0] = idx;
  	cb->args[1] = dn_idx;
  
  	return skb->len;
  }

  static int dn_dev_get_first(struct net_device *dev, __le16 *addr)

  {

  	struct dn_dev *dn_db;

  	struct dn_ifaddr *ifa;
  	int rv = -ENODEV;

  	rcu_read_lock();
  	dn_db = rcu_dereference(dev->dn_ptr);

  	if (dn_db == NULL)
  		goto out;

  	ifa = rcu_dereference(dn_db->ifa_list);

  	if (ifa != NULL) {
  		*addr = ifa->ifa_local;
  		rv = 0;
  	}
  out:

  	rcu_read_unlock();

  	return rv;
  }

  /*

   * Find a default address to bind to.
   *
   * This is one of those areas where the initial VMS concepts don't really
   * map onto the Linux concepts, and since we introduced multiple addresses
   * per interface we have to cope with slightly odd ways of finding out what
   * "our address" really is. Mostly it's not a problem; for this we just guess
   * a sensible default. Eventually the routing code will take care of all the
   * nasties for us I hope.
   */

  int dn_dev_bind_default(__le16 *addr)

  {
  	struct net_device *dev;
  	int rv;
  	dev = dn_dev_get_default();
  last_chance:
  	if (dev) {

  		rv = dn_dev_get_first(dev, addr);

  		dev_put(dev);

  		if (rv == 0 || dev == init_net.loopback_dev)

  			return rv;
  	}

  	dev = init_net.loopback_dev;

  	dev_hold(dev);
  	goto last_chance;
  }
  
  static void dn_send_endnode_hello(struct net_device *dev, struct dn_ifaddr *ifa)
  {

  	struct endnode_hello_message *msg;
  	struct sk_buff *skb = NULL;
  	__le16 *pktlen;

  	struct dn_dev *dn_db = rcu_dereference_raw(dev->dn_ptr);

  	if ((skb = dn_alloc_skb(NULL, sizeof(*msg), GFP_ATOMIC)) == NULL)

  		return;

  	skb->dev = dev;

  	msg = (struct endnode_hello_message *)skb_put(skb,sizeof(*msg));

  	msg->msgflg  = 0x0D;
  	memcpy(msg->tiver, dn_eco_version, 3);

  	dn_dn2eth(msg->id, ifa->ifa_local);

  	msg->iinfo   = DN_RT_INFO_ENDN;

  	msg->blksize = cpu_to_le16(mtu2blksize(dev));

  	msg->area    = 0x00;
  	memset(msg->seed, 0, 8);
  	memcpy(msg->neighbor, dn_hiord, ETH_ALEN);

  
  	if (dn_db->router) {
  		struct dn_neigh *dn = (struct dn_neigh *)dn_db->router;
  		dn_dn2eth(msg->neighbor, dn->addr);
  	}

  	msg->timer   = cpu_to_le16((unsigned short)dn_db->parms.t3);

  	msg->mpd     = 0x00;
  	msg->datalen = 0x02;
  	memset(msg->data, 0xAA, 2);
  
  	pktlen = (__le16 *)skb_push(skb,2);

  	*pktlen = cpu_to_le16(skb->len - 2);

  	skb_reset_network_header(skb);

  
  	dn_rt_finish_output(skb, dn_rt_all_rt_mcast, msg->id);
  }
  
  
  #define DRDELAY (5 * HZ)
  
  static int dn_am_i_a_router(struct dn_neigh *dn, struct dn_dev *dn_db, struct dn_ifaddr *ifa)
  {
  	/* First check time since device went up */
  	if ((jiffies - dn_db->uptime) < DRDELAY)
  		return 0;
  
  	/* If there is no router, then yes... */
  	if (!dn_db->router)
  		return 1;
  
  	/* otherwise only if we have a higher priority or.. */
  	if (dn->priority < dn_db->parms.priority)
  		return 1;
  
  	/* if we have equal priority and a higher node number */
  	if (dn->priority != dn_db->parms.priority)
  		return 0;

  	if (le16_to_cpu(dn->addr) < le16_to_cpu(ifa->ifa_local))

  		return 1;
  
  	return 0;
  }
  
  static void dn_send_router_hello(struct net_device *dev, struct dn_ifaddr *ifa)
  {
  	int n;

  	struct dn_dev *dn_db = rcu_dereference_raw(dev->dn_ptr);

  	struct dn_neigh *dn = (struct dn_neigh *)dn_db->router;
  	struct sk_buff *skb;
  	size_t size;
  	unsigned char *ptr;
  	unsigned char *i1, *i2;

  	__le16 *pktlen;

  	char *src;
  
  	if (mtu2blksize(dev) < (26 + 7))
  		return;
  
  	n = mtu2blksize(dev) - 26;
  	n /= 7;
  
  	if (n > 32)
  		n = 32;
  
  	size = 2 + 26 + 7 * n;
  
  	if ((skb = dn_alloc_skb(NULL, size, GFP_ATOMIC)) == NULL)
  		return;
  
  	skb->dev = dev;
  	ptr = skb_put(skb, size);
  
  	*ptr++ = DN_RT_PKT_CNTL | DN_RT_PKT_ERTH;
  	*ptr++ = 2; /* ECO */
  	*ptr++ = 0;
  	*ptr++ = 0;
  	dn_dn2eth(ptr, ifa->ifa_local);
  	src = ptr;
  	ptr += ETH_ALEN;

  	*ptr++ = dn_db->parms.forwarding == 1 ?

  			DN_RT_INFO_L1RT : DN_RT_INFO_L2RT;

  	*((__le16 *)ptr) = cpu_to_le16(mtu2blksize(dev));

  	ptr += 2;

  	*ptr++ = dn_db->parms.priority; /* Priority */

  	*ptr++ = 0; /* Area: Reserved */

  	*((__le16 *)ptr) = cpu_to_le16((unsigned short)dn_db->parms.t3);

  	ptr += 2;
  	*ptr++ = 0; /* MPD: Reserved */
  	i1 = ptr++;
  	memset(ptr, 0, 7); /* Name: Reserved */
  	ptr += 7;
  	i2 = ptr++;
  
  	n = dn_neigh_elist(dev, ptr, n);
  
  	*i2 = 7 * n;
  	*i1 = 8 + *i2;
  
  	skb_trim(skb, (27 + *i2));

  	pktlen = (__le16 *)skb_push(skb, 2);

  	*pktlen = cpu_to_le16(skb->len - 2);

  	skb_reset_network_header(skb);

  
  	if (dn_am_i_a_router(dn, dn_db, ifa)) {
  		struct sk_buff *skb2 = skb_copy(skb, GFP_ATOMIC);
  		if (skb2) {
  			dn_rt_finish_output(skb2, dn_rt_all_end_mcast, src);
  		}
  	}
  
  	dn_rt_finish_output(skb, dn_rt_all_rt_mcast, src);
  }
  
  static void dn_send_brd_hello(struct net_device *dev, struct dn_ifaddr *ifa)
  {

  	struct dn_dev *dn_db = rcu_dereference_raw(dev->dn_ptr);

  
  	if (dn_db->parms.forwarding == 0)
  		dn_send_endnode_hello(dev, ifa);
  	else
  		dn_send_router_hello(dev, ifa);
  }
  
  static void dn_send_ptp_hello(struct net_device *dev, struct dn_ifaddr *ifa)
  {
  	int tdlen = 16;
  	int size = dev->hard_header_len + 2 + 4 + tdlen;
  	struct sk_buff *skb = dn_alloc_skb(NULL, size, GFP_ATOMIC);
  	int i;
  	unsigned char *ptr;
  	char src[ETH_ALEN];
  
  	if (skb == NULL)
  		return ;
  
  	skb->dev = dev;
  	skb_push(skb, dev->hard_header_len);
  	ptr = skb_put(skb, 2 + 4 + tdlen);
  
  	*ptr++ = DN_RT_PKT_HELO;

  	*((__le16 *)ptr) = ifa->ifa_local;

  	ptr += 2;
  	*ptr++ = tdlen;
  
  	for(i = 0; i < tdlen; i++)
  		*ptr++ = 0252;
  
  	dn_dn2eth(src, ifa->ifa_local);
  	dn_rt_finish_output(skb, dn_rt_all_rt_mcast, src);
  }
  
  static int dn_eth_up(struct net_device *dev)
  {

  	struct dn_dev *dn_db = rcu_dereference_raw(dev->dn_ptr);

  
  	if (dn_db->parms.forwarding == 0)

  		dev_mc_add(dev, dn_rt_all_end_mcast);

  	else

  		dev_mc_add(dev, dn_rt_all_rt_mcast);

  	dn_db->use_long = 1;
  
  	return 0;
  }
  
  static void dn_eth_down(struct net_device *dev)
  {

  	struct dn_dev *dn_db = rcu_dereference_raw(dev->dn_ptr);

  
  	if (dn_db->parms.forwarding == 0)

  		dev_mc_del(dev, dn_rt_all_end_mcast);

  	else

  		dev_mc_del(dev, dn_rt_all_rt_mcast);

  }
  
  static void dn_dev_set_timer(struct net_device *dev);
  
  static void dn_dev_timer_func(unsigned long arg)
  {
  	struct net_device *dev = (struct net_device *)arg;

  	struct dn_dev *dn_db;

  	struct dn_ifaddr *ifa;

  	rcu_read_lock();
  	dn_db = rcu_dereference(dev->dn_ptr);

  	if (dn_db->t3 <= dn_db->parms.t2) {
  		if (dn_db->parms.timer3) {

  			for (ifa = rcu_dereference(dn_db->ifa_list);
  			     ifa;
  			     ifa = rcu_dereference(ifa->ifa_next)) {

  				if (!(ifa->ifa_flags & IFA_F_SECONDARY))
  					dn_db->parms.timer3(dev, ifa);
  			}
  		}
  		dn_db->t3 = dn_db->parms.t3;
  	} else {
  		dn_db->t3 -= dn_db->parms.t2;
  	}

  	rcu_read_unlock();

  	dn_dev_set_timer(dev);
  }
  
  static void dn_dev_set_timer(struct net_device *dev)
  {

  	struct dn_dev *dn_db = rcu_dereference_raw(dev->dn_ptr);

  
  	if (dn_db->parms.t2 > dn_db->parms.t3)
  		dn_db->parms.t2 = dn_db->parms.t3;
  
  	dn_db->timer.data = (unsigned long)dev;
  	dn_db->timer.function = dn_dev_timer_func;
  	dn_db->timer.expires = jiffies + (dn_db->parms.t2 * HZ);
  
  	add_timer(&dn_db->timer);
  }

  static struct dn_dev *dn_dev_create(struct net_device *dev, int *err)

  {
  	int i;
  	struct dn_dev_parms *p = dn_dev_list;
  	struct dn_dev *dn_db;
  
  	for(i = 0; i < DN_DEV_LIST_SIZE; i++, p++) {
  		if (p->type == dev->type)
  			break;
  	}
  
  	*err = -ENODEV;
  	if (i == DN_DEV_LIST_SIZE)
  		return NULL;
  
  	*err = -ENOBUFS;

  	if ((dn_db = kzalloc(sizeof(struct dn_dev), GFP_ATOMIC)) == NULL)

  		return NULL;

  	memcpy(&dn_db->parms, p, sizeof(struct dn_dev_parms));

  	rcu_assign_pointer(dev->dn_ptr, dn_db);

  	dn_db->dev = dev;
  	init_timer(&dn_db->timer);
  
  	dn_db->uptime = jiffies;

  
  	dn_db->neigh_parms = neigh_parms_alloc(dev, &dn_neigh_table);
  	if (!dn_db->neigh_parms) {

  		RCU_INIT_POINTER(dev->dn_ptr, NULL);

  		kfree(dn_db);
  		return NULL;
  	}

  	if (dn_db->parms.up) {
  		if (dn_db->parms.up(dev) < 0) {

  			neigh_parms_release(&dn_neigh_table, dn_db->neigh_parms);

  			dev->dn_ptr = NULL;
  			kfree(dn_db);
  			return NULL;
  		}
  	}

  	dn_dev_sysctl_register(dev, &dn_db->parms);
  
  	dn_dev_set_timer(dev);
  
  	*err = 0;
  	return dn_db;
  }
  
  
  /*
   * This processes a device up event. We only start up
   * the loopback device & ethernet devices with correct

   * MAC addresses automatically. Others must be started

   * specifically.
   *
   * FIXME: How should we configure the loopback address ? If we could dispense
   * with using decnet_address here and for autobind, it will be one less thing
   * for users to worry about setting up.
   */
  
  void dn_dev_up(struct net_device *dev)
  {
  	struct dn_ifaddr *ifa;

  	__le16 addr = decnet_address;

  	int maybe_default = 0;

  	struct dn_dev *dn_db = rtnl_dereference(dev->dn_ptr);

  
  	if ((dev->type != ARPHRD_ETHER) && (dev->type != ARPHRD_LOOPBACK))
  		return;
  
  	/*
  	 * Need to ensure that loopback device has a dn_db attached to it
  	 * to allow creation of neighbours against it, even though it might
  	 * not have a local address of its own. Might as well do the same for
  	 * all autoconfigured interfaces.
  	 */
  	if (dn_db == NULL) {
  		int err;
  		dn_db = dn_dev_create(dev, &err);
  		if (dn_db == NULL)
  			return;
  	}
  
  	if (dev->type == ARPHRD_ETHER) {
  		if (memcmp(dev->dev_addr, dn_hiord, 4) != 0)
  			return;

  		addr = dn_eth2dn(dev->dev_addr);

  		maybe_default = 1;
  	}
  
  	if (addr == 0)
  		return;
  
  	if ((ifa = dn_dev_alloc_ifa()) == NULL)
  		return;
  
  	ifa->ifa_local = ifa->ifa_address = addr;
  	ifa->ifa_flags = 0;
  	ifa->ifa_scope = RT_SCOPE_UNIVERSE;
  	strcpy(ifa->ifa_label, dev->name);
  
  	dn_dev_set_ifa(dev, ifa);
  
  	/*
  	 * Automagically set the default device to the first automatically
  	 * configured ethernet card in the system.
  	 */
  	if (maybe_default) {
  		dev_hold(dev);
  		if (dn_dev_set_default(dev, 0))
  			dev_put(dev);
  	}
  }
  
  static void dn_dev_delete(struct net_device *dev)
  {

  	struct dn_dev *dn_db = rtnl_dereference(dev->dn_ptr);

  
  	if (dn_db == NULL)
  		return;
  
  	del_timer_sync(&dn_db->timer);
  	dn_dev_sysctl_unregister(&dn_db->parms);
  	dn_dev_check_default(dev);
  	neigh_ifdown(&dn_neigh_table, dev);
  
  	if (dn_db->parms.down)
  		dn_db->parms.down(dev);
  
  	dev->dn_ptr = NULL;
  
  	neigh_parms_release(&dn_neigh_table, dn_db->neigh_parms);
  	neigh_ifdown(&dn_neigh_table, dev);
  
  	if (dn_db->router)
  		neigh_release(dn_db->router);
  	if (dn_db->peer)
  		neigh_release(dn_db->peer);
  
  	kfree(dn_db);
  }
  
  void dn_dev_down(struct net_device *dev)
  {

  	struct dn_dev *dn_db = rtnl_dereference(dev->dn_ptr);

  	struct dn_ifaddr *ifa;
  
  	if (dn_db == NULL)
  		return;

  	while ((ifa = rtnl_dereference(dn_db->ifa_list)) != NULL) {

  		dn_dev_del_ifa(dn_db, &dn_db->ifa_list, 0);
  		dn_dev_free_ifa(ifa);
  	}
  
  	dn_dev_delete(dev);
  }
  
  void dn_dev_init_pkt(struct sk_buff *skb)
  {

  }
  
  void dn_dev_veri_pkt(struct sk_buff *skb)
  {

  }
  
  void dn_dev_hello(struct sk_buff *skb)
  {

  }
  
  void dn_dev_devices_off(void)
  {
  	struct net_device *dev;
  
  	rtnl_lock();

  	for_each_netdev(&init_net, dev)

  		dn_dev_down(dev);
  	rtnl_unlock();
  
  }
  
  void dn_dev_devices_on(void)
  {
  	struct net_device *dev;
  
  	rtnl_lock();

  	for_each_netdev(&init_net, dev) {

  		if (dev->flags & IFF_UP)
  			dn_dev_up(dev);
  	}
  	rtnl_unlock();
  }
  
  int register_dnaddr_notifier(struct notifier_block *nb)
  {

  	return blocking_notifier_chain_register(&dnaddr_chain, nb);

  }
  
  int unregister_dnaddr_notifier(struct notifier_block *nb)
  {

  	return blocking_notifier_chain_unregister(&dnaddr_chain, nb);

  }
  
  #ifdef CONFIG_PROC_FS

  static inline int is_dn_dev(struct net_device *dev)

  {

  	return dev->dn_ptr != NULL;

  }

  static void *dn_dev_seq_start(struct seq_file *seq, loff_t *pos)

  	__acquires(RCU)

  {

  	int i;

  	struct net_device *dev;

  	rcu_read_lock();

  	if (*pos == 0)
  		return SEQ_START_TOKEN;
  
  	i = 1;

  	for_each_netdev_rcu(&init_net, dev) {

  		if (!is_dn_dev(dev))
  			continue;
  
  		if (i++ == *pos)
  			return dev;

  	}

  
  	return NULL;

  }
  
  static void *dn_dev_seq_next(struct seq_file *seq, void *v, loff_t *pos)
  {

  	struct net_device *dev;

  	++*pos;

  	dev = v;

  	if (v == SEQ_START_TOKEN)

  		dev = net_device_entry(&init_net.dev_base_head);

  	for_each_netdev_continue_rcu(&init_net, dev) {

  		if (!is_dn_dev(dev))
  			continue;
  
  		return dev;
  	}
  
  	return NULL;

  }
  
  static void dn_dev_seq_stop(struct seq_file *seq, void *v)

  	__releases(RCU)

  {

  	rcu_read_unlock();

  }
  
  static char *dn_type2asc(char type)
  {

  	switch (type) {
  	case DN_DEV_BCAST:
  		return "B";
  	case DN_DEV_UCAST:
  		return "U";
  	case DN_DEV_MPOINT:
  		return "M";

  	}
  
  	return "?";
  }
  
  static int dn_dev_seq_show(struct seq_file *seq, void *v)
  {
  	if (v == SEQ_START_TOKEN)

  		seq_puts(seq, "Name     Flags T1   Timer1 T3   Timer3 BlkSize Pri State DevType    Router Peer
  ");

  	else {
  		struct net_device *dev = v;
  		char peer_buf[DN_ASCBUF_LEN];
  		char router_buf[DN_ASCBUF_LEN];

  		struct dn_dev *dn_db = rcu_dereference(dev->dn_ptr);

  		seq_printf(seq, "%-8s %1s     %04u %04u   %04lu %04lu"

  				"   %04hu    %03d %02x    %-10s %-7s %-7s
  ",

  				dev->name ? dev->name : "???",
  				dn_type2asc(dn_db->parms.mode),
  				0, 0,

  				dn_db->t3, dn_db->parms.t3,
  				mtu2blksize(dev),
  				dn_db->parms.priority,
  				dn_db->parms.state, dn_db->parms.name,

  				dn_db->router ? dn_addr2asc(le16_to_cpu(*(__le16 *)dn_db->router->primary_key), router_buf) : "",
  				dn_db->peer ? dn_addr2asc(le16_to_cpu(*(__le16 *)dn_db->peer->primary_key), peer_buf) : "");

  	}
  	return 0;
  }

  static const struct seq_operations dn_dev_seq_ops = {

  	.start	= dn_dev_seq_start,
  	.next	= dn_dev_seq_next,
  	.stop	= dn_dev_seq_stop,
  	.show	= dn_dev_seq_show,
  };
  
  static int dn_dev_seq_open(struct inode *inode, struct file *file)
  {
  	return seq_open(file, &dn_dev_seq_ops);
  }

  static const struct file_operations dn_dev_seq_fops = {

  	.owner	 = THIS_MODULE,
  	.open	 = dn_dev_seq_open,
  	.read	 = seq_read,
  	.llseek	 = seq_lseek,
  	.release = seq_release,
  };
  
  #endif /* CONFIG_PROC_FS */

  static int addr[2];

  module_param_array(addr, int, NULL, 0444);
  MODULE_PARM_DESC(addr, "The DECnet address of this machine: area,node");
  
  void __init dn_dev_init(void)
  {

  	if (addr[0] > 63 || addr[0] < 0) {
  		printk(KERN_ERR "DECnet: Area must be between 0 and 63");
  		return;
  	}

  	if (addr[1] > 1023 || addr[1] < 0) {
  		printk(KERN_ERR "DECnet: Node must be between 0 and 1023");
  		return;
  	}

  	decnet_address = cpu_to_le16((addr[0] << 10) | addr[1]);

  
  	dn_dev_devices_on();

  	rtnl_register(PF_DECnet, RTM_NEWADDR, dn_nl_newaddr, NULL, NULL);
  	rtnl_register(PF_DECnet, RTM_DELADDR, dn_nl_deladdr, NULL, NULL);
  	rtnl_register(PF_DECnet, RTM_GETADDR, NULL, dn_nl_dump_ifaddr, NULL);

  	proc_net_fops_create(&init_net, "decnet_dev", S_IRUGO, &dn_dev_seq_fops);

  
  #ifdef CONFIG_SYSCTL
  	{
  		int i;
  		for(i = 0; i < DN_DEV_LIST_SIZE; i++)
  			dn_dev_sysctl_register(NULL, &dn_dev_list[i]);
  	}
  #endif /* CONFIG_SYSCTL */
  }
  
  void __exit dn_dev_cleanup(void)
  {

  #ifdef CONFIG_SYSCTL
  	{
  		int i;
  		for(i = 0; i < DN_DEV_LIST_SIZE; i++)
  			dn_dev_sysctl_unregister(&dn_dev_list[i]);
  	}
  #endif /* CONFIG_SYSCTL */

  	proc_net_remove(&init_net, "decnet_dev");

  
  	dn_dev_devices_off();
  }