[linux-block.git] / net / decnet / dn_neigh.c

// SPDX-License-Identifier: GPL-2.0
/*
 * 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 Neighbour Functions (Adjacency Database and
 *                                                        On-Ethernet Cache)
 *
 * Author:      Steve Whitehouse <SteveW@ACM.org>
 *
 *
 * Changes:
 *     Steve Whitehouse     : Fixed router listing routine
 *     Steve Whitehouse     : Added error_report functions
 *     Steve Whitehouse     : Added default router detection
 *     Steve Whitehouse     : Hop counts in outgoing messages
 *     Steve Whitehouse     : Fixed src/dst in outgoing messages so
 *                            forwarding now stands a good chance of
 *                            working.
 *     Steve Whitehouse     : Fixed neighbour states (for now anyway).
 *     Steve Whitehouse     : Made error_report functions dummies. This
 *                            is not the right place to return skbs.
 *     Steve Whitehouse     : Convert to seq_file
 *
 */

#include <linux/net.h>
#include <linux/module.h>
#include <linux/socket.h>
#include <linux/if_arp.h>
#include <linux/slab.h>
#include <linux/if_ether.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/string.h>
#include <linux/netfilter_decnet.h>
#include <linux/spinlock.h>
#include <linux/seq_file.h>
#include <linux/rcupdate.h>
#include <linux/jhash.h>
#include <linux/atomic.h>
#include <net/net_namespace.h>
#include <net/neighbour.h>
#include <net/dst.h>
#include <net/flow.h>
#include <net/dn.h>
#include <net/dn_dev.h>
#include <net/dn_neigh.h>
#include <net/dn_route.h>

static int dn_neigh_construct(struct neighbour *);
static void dn_neigh_error_report(struct neighbour *, struct sk_buff *);
static int dn_neigh_output(struct neighbour *neigh, struct sk_buff *skb);

/*
 * Operations for adding the link layer header.
 */
static const struct neigh_ops dn_neigh_ops = {
	.family =		AF_DECnet,
	.error_report =		dn_neigh_error_report,
	.output =		dn_neigh_output,
	.connected_output =	dn_neigh_output,
};

static u32 dn_neigh_hash(const void *pkey,
			 const struct net_device *dev,
			 __u32 *hash_rnd)
{
	return jhash_2words(*(__u16 *)pkey, 0, hash_rnd[0]);
}

static bool dn_key_eq(const struct neighbour *neigh, const void *pkey)
{
	return neigh_key_eq16(neigh, pkey);
}

struct neigh_table dn_neigh_table = {
	.family =			PF_DECnet,
	.entry_size =			NEIGH_ENTRY_SIZE(sizeof(struct dn_neigh)),
	.key_len =			sizeof(__le16),
	.protocol =			cpu_to_be16(ETH_P_DNA_RT),
	.hash =				dn_neigh_hash,
	.key_eq =			dn_key_eq,
	.constructor =			dn_neigh_construct,
	.id =				"dn_neigh_cache",
	.parms ={
		.tbl =			&dn_neigh_table,
		.reachable_time =	30 * HZ,
		.data = {
			[NEIGH_VAR_MCAST_PROBES] = 0,
			[NEIGH_VAR_UCAST_PROBES] = 0,
			[NEIGH_VAR_APP_PROBES] = 0,
			[NEIGH_VAR_RETRANS_TIME] = 1 * HZ,
			[NEIGH_VAR_BASE_REACHABLE_TIME] = 30 * HZ,
			[NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ,
			[NEIGH_VAR_GC_STALETIME] = 60 * HZ,
			[NEIGH_VAR_QUEUE_LEN_BYTES] = SK_WMEM_MAX,
			[NEIGH_VAR_PROXY_QLEN] = 0,
			[NEIGH_VAR_ANYCAST_DELAY] = 0,
			[NEIGH_VAR_PROXY_DELAY] = 0,
			[NEIGH_VAR_LOCKTIME] = 1 * HZ,
		},
	},
	.gc_interval =			30 * HZ,
	.gc_thresh1 =			128,
	.gc_thresh2 =			512,
	.gc_thresh3 =			1024,
};

static int dn_neigh_construct(struct neighbour *neigh)
{
	struct net_device *dev = neigh->dev;
	struct dn_neigh *dn = container_of(neigh, struct dn_neigh, n);
	struct dn_dev *dn_db;
	struct neigh_parms *parms;

	rcu_read_lock();
	dn_db = rcu_dereference(dev->dn_ptr);
	if (dn_db == NULL) {
		rcu_read_unlock();
		return -EINVAL;
	}

	parms = dn_db->neigh_parms;
	if (!parms) {
		rcu_read_unlock();
		return -EINVAL;
	}

	__neigh_parms_put(neigh->parms);
	neigh->parms = neigh_parms_clone(parms);
	rcu_read_unlock();

	neigh->ops = &dn_neigh_ops;
	neigh->nud_state = NUD_NOARP;
	neigh->output = neigh->ops->connected_output;

	if ((dev->type == ARPHRD_IPGRE) || (dev->flags & IFF_POINTOPOINT))
		memcpy(neigh->ha, dev->broadcast, dev->addr_len);
	else if ((dev->type == ARPHRD_ETHER) || (dev->type == ARPHRD_LOOPBACK))
		dn_dn2eth(neigh->ha, dn->addr);
	else {
		net_dbg_ratelimited("Trying to create neigh for hw %d\n",
				    dev->type);
		return -EINVAL;
	}

	/*
	 * Make an estimate of the remote block size by assuming that its
	 * two less then the device mtu, which it true for ethernet (and
	 * other things which support long format headers) since there is
	 * an extra length field (of 16 bits) which isn't part of the
	 * ethernet headers and which the DECnet specs won't admit is part
	 * of the DECnet routing headers either.
	 *
	 * If we over estimate here its no big deal, the NSP negotiations
	 * will prevent us from sending packets which are too large for the
	 * remote node to handle. In any case this figure is normally updated
	 * by a hello message in most cases.
	 */
	dn->blksize = dev->mtu - 2;

	return 0;
}

static void dn_neigh_error_report(struct neighbour *neigh, struct sk_buff *skb)
{
	printk(KERN_DEBUG "dn_neigh_error_report: called\n");
	kfree_skb(skb);
}

static int dn_neigh_output(struct neighbour *neigh, struct sk_buff *skb)
{
	struct dst_entry *dst = skb_dst(skb);
	struct dn_route *rt = (struct dn_route *)dst;
	struct net_device *dev = neigh->dev;
	char mac_addr[ETH_ALEN];
	unsigned int seq;
	int err;

	dn_dn2eth(mac_addr, rt->rt_local_src);
	do {
		seq = read_seqbegin(&neigh->ha_lock);
		err = dev_hard_header(skb, dev, ntohs(skb->protocol),
				      neigh->ha, mac_addr, skb->len);
	} while (read_seqretry(&neigh->ha_lock, seq));

	if (err >= 0)
		err = dev_queue_xmit(skb);
	else {
		kfree_skb(skb);
		err = -EINVAL;
	}
	return err;
}

static int dn_neigh_output_packet(struct net *net, struct sock *sk, struct sk_buff *skb)
{
	struct dst_entry *dst = skb_dst(skb);
	struct dn_route *rt = (struct dn_route *)dst;
	struct neighbour *neigh = rt->n;

	return neigh->output(neigh, skb);
}

/*
 * For talking to broadcast devices: Ethernet & PPP
 */
static int dn_long_output(struct neighbour *neigh, struct sock *sk,
			  struct sk_buff *skb)
{
	struct net_device *dev = neigh->dev;
	int headroom = dev->hard_header_len + sizeof(struct dn_long_packet) + 3;
	unsigned char *data;
	struct dn_long_packet *lp;
	struct dn_skb_cb *cb = DN_SKB_CB(skb);


	if (skb_headroom(skb) < headroom) {
		struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom);
		if (skb2 == NULL) {
			net_crit_ratelimited("dn_long_output: no memory\n");
			kfree_skb(skb);
			return -ENOBUFS;
		}
		consume_skb(skb);
		skb = skb2;
		net_info_ratelimited("dn_long_output: Increasing headroom\n");
	}

	data = skb_push(skb, sizeof(struct dn_long_packet) + 3);
	lp = (struct dn_long_packet *)(data+3);

	*((__le16 *)data) = cpu_to_le16(skb->len - 2);
	*(data + 2) = 1 | DN_RT_F_PF; /* Padding */

	lp->msgflg   = DN_RT_PKT_LONG|(cb->rt_flags&(DN_RT_F_IE|DN_RT_F_RQR|DN_RT_F_RTS));
	lp->d_area   = lp->d_subarea = 0;
	dn_dn2eth(lp->d_id, cb->dst);
	lp->s_area   = lp->s_subarea = 0;
	dn_dn2eth(lp->s_id, cb->src);
	lp->nl2      = 0;
	lp->visit_ct = cb->hops & 0x3f;
	lp->s_class  = 0;
	lp->pt       = 0;

	skb_reset_network_header(skb);

	return NF_HOOK(NFPROTO_DECNET, NF_DN_POST_ROUTING,
		       &init_net, sk, skb, NULL, neigh->dev,
		       dn_neigh_output_packet);
}

/*
 * For talking to pointopoint and multidrop devices: DDCMP and X.25
 */
static int dn_short_output(struct neighbour *neigh, struct sock *sk,
			   struct sk_buff *skb)
{
	struct net_device *dev = neigh->dev;
	int headroom = dev->hard_header_len + sizeof(struct dn_short_packet) + 2;
	struct dn_short_packet *sp;
	unsigned char *data;
	struct dn_skb_cb *cb = DN_SKB_CB(skb);


	if (skb_headroom(skb) < headroom) {
		struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom);
		if (skb2 == NULL) {
			net_crit_ratelimited("dn_short_output: no memory\n");
			kfree_skb(skb);
			return -ENOBUFS;
		}
		consume_skb(skb);
		skb = skb2;
		net_info_ratelimited("dn_short_output: Increasing headroom\n");
	}

	data = skb_push(skb, sizeof(struct dn_short_packet) + 2);
	*((__le16 *)data) = cpu_to_le16(skb->len - 2);
	sp = (struct dn_short_packet *)(data+2);

	sp->msgflg     = DN_RT_PKT_SHORT|(cb->rt_flags&(DN_RT_F_RQR|DN_RT_F_RTS));
	sp->dstnode    = cb->dst;
	sp->srcnode    = cb->src;
	sp->forward    = cb->hops & 0x3f;

	skb_reset_network_header(skb);

	return NF_HOOK(NFPROTO_DECNET, NF_DN_POST_ROUTING,
		       &init_net, sk, skb, NULL, neigh->dev,
		       dn_neigh_output_packet);
}

/*
 * For talking to DECnet phase III nodes
 * Phase 3 output is the same as short output, execpt that
 * it clears the area bits before transmission.
 */
static int dn_phase3_output(struct neighbour *neigh, struct sock *sk,
			    struct sk_buff *skb)
{
	struct net_device *dev = neigh->dev;
	int headroom = dev->hard_header_len + sizeof(struct dn_short_packet) + 2;
	struct dn_short_packet *sp;
	unsigned char *data;
	struct dn_skb_cb *cb = DN_SKB_CB(skb);

	if (skb_headroom(skb) < headroom) {
		struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom);
		if (skb2 == NULL) {
			net_crit_ratelimited("dn_phase3_output: no memory\n");
			kfree_skb(skb);
			return -ENOBUFS;
		}
		consume_skb(skb);
		skb = skb2;
		net_info_ratelimited("dn_phase3_output: Increasing headroom\n");
	}

	data = skb_push(skb, sizeof(struct dn_short_packet) + 2);
	*((__le16 *)data) = cpu_to_le16(skb->len - 2);
	sp = (struct dn_short_packet *)(data + 2);

	sp->msgflg   = DN_RT_PKT_SHORT|(cb->rt_flags&(DN_RT_F_RQR|DN_RT_F_RTS));
	sp->dstnode  = cb->dst & cpu_to_le16(0x03ff);
	sp->srcnode  = cb->src & cpu_to_le16(0x03ff);
	sp->forward  = cb->hops & 0x3f;

	skb_reset_network_header(skb);

	return NF_HOOK(NFPROTO_DECNET, NF_DN_POST_ROUTING,
		       &init_net, sk, skb, NULL, neigh->dev,
		       dn_neigh_output_packet);
}

int dn_to_neigh_output(struct net *net, struct sock *sk, struct sk_buff *skb)
{
	struct dst_entry *dst = skb_dst(skb);
	struct dn_route *rt = (struct dn_route *) dst;
	struct neighbour *neigh = rt->n;
	struct dn_neigh *dn = container_of(neigh, struct dn_neigh, n);
	struct dn_dev *dn_db;
	bool use_long;

	rcu_read_lock();
	dn_db = rcu_dereference(neigh->dev->dn_ptr);
	if (dn_db == NULL) {
		rcu_read_unlock();
		return -EINVAL;
	}
	use_long = dn_db->use_long;
	rcu_read_unlock();

	if (dn->flags & DN_NDFLAG_P3)
		return dn_phase3_output(neigh, sk, skb);
	if (use_long)
		return dn_long_output(neigh, sk, skb);
	else
		return dn_short_output(neigh, sk, skb);
}

/*
 * Unfortunately, the neighbour code uses the device in its hash
 * function, so we don't get any advantage from it. This function
 * basically does a neigh_lookup(), but without comparing the device
 * field. This is required for the On-Ethernet cache
 */

/*
 * Pointopoint link receives a hello message
 */
void dn_neigh_pointopoint_hello(struct sk_buff *skb)
{
	kfree_skb(skb);
}

/*
 * Ethernet router hello message received
 */
int dn_neigh_router_hello(struct net *net, struct sock *sk, struct sk_buff *skb)
{
	struct rtnode_hello_message *msg = (struct rtnode_hello_message *)skb->data;

	struct neighbour *neigh;
	struct dn_neigh *dn;
	struct dn_dev *dn_db;
	__le16 src;

	src = dn_eth2dn(msg->id);

	neigh = __neigh_lookup(&dn_neigh_table, &src, skb->dev, 1);

	dn = container_of(neigh, struct dn_neigh, n);

	if (neigh) {
		write_lock(&neigh->lock);

		neigh->used = jiffies;
		dn_db = rcu_dereference(neigh->dev->dn_ptr);

		if (!(neigh->nud_state & NUD_PERMANENT)) {
			neigh->updated = jiffies;

			if (neigh->dev->type == ARPHRD_ETHER)
				memcpy(neigh->ha, &eth_hdr(skb)->h_source, ETH_ALEN);

			dn->blksize  = le16_to_cpu(msg->blksize);
			dn->priority = msg->priority;

			dn->flags &= ~DN_NDFLAG_P3;

			switch (msg->iinfo & DN_RT_INFO_TYPE) {
			case DN_RT_INFO_L1RT:
				dn->flags &=~DN_NDFLAG_R2;
				dn->flags |= DN_NDFLAG_R1;
				break;
			case DN_RT_INFO_L2RT:
				dn->flags |= DN_NDFLAG_R2;
			}
		}

		/* Only use routers in our area */
		if ((le16_to_cpu(src)>>10) == (le16_to_cpu((decnet_address))>>10)) {
			if (!dn_db->router) {
				dn_db->router = neigh_clone(neigh);
			} else {
				if (msg->priority > ((struct dn_neigh *)dn_db->router)->priority)
					neigh_release(xchg(&dn_db->router, neigh_clone(neigh)));
			}
		}
		write_unlock(&neigh->lock);
		neigh_release(neigh);
	}

	kfree_skb(skb);
	return 0;
}

/*
 * Endnode hello message received
 */
int dn_neigh_endnode_hello(struct net *net, struct sock *sk, struct sk_buff *skb)
{
	struct endnode_hello_message *msg = (struct endnode_hello_message *)skb->data;
	struct neighbour *neigh;
	struct dn_neigh *dn;
	__le16 src;

	src = dn_eth2dn(msg->id);

	neigh = __neigh_lookup(&dn_neigh_table, &src, skb->dev, 1);

	dn = container_of(neigh, struct dn_neigh, n);

	if (neigh) {
		write_lock(&neigh->lock);

		neigh->used = jiffies;

		if (!(neigh->nud_state & NUD_PERMANENT)) {
			neigh->updated = jiffies;

			if (neigh->dev->type == ARPHRD_ETHER)
				memcpy(neigh->ha, &eth_hdr(skb)->h_source, ETH_ALEN);
			dn->flags   &= ~(DN_NDFLAG_R1 | DN_NDFLAG_R2);
			dn->blksize  = le16_to_cpu(msg->blksize);
			dn->priority = 0;
		}

		write_unlock(&neigh->lock);
		neigh_release(neigh);
	}

	kfree_skb(skb);
	return 0;
}

static char *dn_find_slot(char *base, int max, int priority)
{
	int i;
	unsigned char *min = NULL;

	base += 6; /* skip first id */

	for(i = 0; i < max; i++) {
		if (!min || (*base < *min))
			min = base;
		base += 7; /* find next priority */
	}

	if (!min)
		return NULL;

	return (*min < priority) ? (min - 6) : NULL;
}

struct elist_cb_state {
	struct net_device *dev;
	unsigned char *ptr;
	unsigned char *rs;
	int t, n;
};

static void neigh_elist_cb(struct neighbour *neigh, void *_info)
{
	struct elist_cb_state *s = _info;
	struct dn_neigh *dn;

	if (neigh->dev != s->dev)
		return;

	dn = container_of(neigh, struct dn_neigh, n);
	if (!(dn->flags & (DN_NDFLAG_R1|DN_NDFLAG_R2)))
		return;

	if (s->t == s->n)
		s->rs = dn_find_slot(s->ptr, s->n, dn->priority);
	else
		s->t++;
	if (s->rs == NULL)
		return;

	dn_dn2eth(s->rs, dn->addr);
	s->rs += 6;
	*(s->rs) = neigh->nud_state & NUD_CONNECTED ? 0x80 : 0x0;
	*(s->rs) |= dn->priority;
	s->rs++;
}

int dn_neigh_elist(struct net_device *dev, unsigned char *ptr, int n)
{
	struct elist_cb_state state;

	state.dev = dev;
	state.t = 0;
	state.n = n;
	state.ptr = ptr;
	state.rs = ptr;

	neigh_for_each(&dn_neigh_table, neigh_elist_cb, &state);

	return state.t;
}


#ifdef CONFIG_PROC_FS

static inline void dn_neigh_format_entry(struct seq_file *seq,
					 struct neighbour *n)
{
	struct dn_neigh *dn = container_of(n, struct dn_neigh, n);
	char buf[DN_ASCBUF_LEN];

	read_lock(&n->lock);
	seq_printf(seq, "%-7s %s%s%s   %02x    %02d  %07ld %-8s\n",
		   dn_addr2asc(le16_to_cpu(dn->addr), buf),
		   (dn->flags&DN_NDFLAG_R1) ? "1" : "-",
		   (dn->flags&DN_NDFLAG_R2) ? "2" : "-",
		   (dn->flags&DN_NDFLAG_P3) ? "3" : "-",
		   dn->n.nud_state,
		   refcount_read(&dn->n.refcnt),
		   dn->blksize,
		   (dn->n.dev) ? dn->n.dev->name : "?");
	read_unlock(&n->lock);
}

static int dn_neigh_seq_show(struct seq_file *seq, void *v)
{
	if (v == SEQ_START_TOKEN) {
		seq_puts(seq, "Addr    Flags State Use Blksize Dev\n");
	} else {
		dn_neigh_format_entry(seq, v);
	}

	return 0;
}

static void *dn_neigh_seq_start(struct seq_file *seq, loff_t *pos)
{
	return neigh_seq_start(seq, pos, &dn_neigh_table,
			       NEIGH_SEQ_NEIGH_ONLY);
}

static const struct seq_operations dn_neigh_seq_ops = {
	.start = dn_neigh_seq_start,
	.next  = neigh_seq_next,
	.stop  = neigh_seq_stop,
	.show  = dn_neigh_seq_show,
};

static int dn_neigh_seq_open(struct inode *inode, struct file *file)
{
	return seq_open_net(inode, file, &dn_neigh_seq_ops,
			    sizeof(struct neigh_seq_state));
}

static const struct file_operations dn_neigh_seq_fops = {
	.owner		= THIS_MODULE,
	.open		= dn_neigh_seq_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= seq_release_net,
};

#endif

void __init dn_neigh_init(void)
{
	neigh_table_init(NEIGH_DN_TABLE, &dn_neigh_table);
	proc_create("decnet_neigh", S_IRUGO, init_net.proc_net,
		    &dn_neigh_seq_fops);
}

void __exit dn_neigh_cleanup(void)
{
	remove_proc_entry("decnet_neigh", init_net.proc_net);
	neigh_table_clear(NEIGH_DN_TABLE, &dn_neigh_table);
}
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
1da177e4 LT	2	/*
	3	* DECnet An implementation of the DECnet protocol suite for the LINUX
	4	* operating system. DECnet is implemented using the BSD Socket
	5	* interface as the means of communication with the user level.
	6	*
429eb0fa	7	* DECnet Neighbour Functions (Adjacency Database and
1da177e4 LT	8	* On-Ethernet Cache)
	9	*
	10	* Author: Steve Whitehouse <SteveW@ACM.org>
	11	*
	12	*
	13	* Changes:
	14	* Steve Whitehouse : Fixed router listing routine
	15	* Steve Whitehouse : Added error_report functions
	16	* Steve Whitehouse : Added default router detection
	17	* Steve Whitehouse : Hop counts in outgoing messages
	18	* Steve Whitehouse : Fixed src/dst in outgoing messages so
	19	* forwarding now stands a good chance of
	20	* working.
	21	* Steve Whitehouse : Fixed neighbour states (for now anyway).
	22	* Steve Whitehouse : Made error_report functions dummies. This
	23	* is not the right place to return skbs.
	24	* Steve Whitehouse : Convert to seq_file
	25	*
	26	*/
	27
1da177e4 LT	28	#include <linux/net.h>
	29	#include <linux/module.h>
	30	#include <linux/socket.h>
	31	#include <linux/if_arp.h>
5a0e3ad6	32	#include <linux/slab.h>
1da177e4 LT	33	#include <linux/if_ether.h>
	34	#include <linux/init.h>
	35	#include <linux/proc_fs.h>
	36	#include <linux/string.h>
	37	#include <linux/netfilter_decnet.h>
	38	#include <linux/spinlock.h>
	39	#include <linux/seq_file.h>
	40	#include <linux/rcupdate.h>
	41	#include <linux/jhash.h>
60063497	42	#include <linux/atomic.h>
457c4cbc	43	#include <net/net_namespace.h>
1da177e4 LT	44	#include <net/neighbour.h>
	45	#include <net/dst.h>
	46	#include <net/flow.h>
	47	#include <net/dn.h>
	48	#include <net/dn_dev.h>
	49	#include <net/dn_neigh.h>
	50	#include <net/dn_route.h>
	51
1da177e4	52	static int dn_neigh_construct(struct neighbour *);
aaa4e704 EB	53	static void dn_neigh_error_report(struct neighbour , struct sk_buff );
aaa4e704 EB	54	static int dn_neigh_output(struct neighbour neigh, struct sk_buff skb);
1da177e4 LT	55
1da177e4 LT	56	/*
aaa4e704	57	* Operations for adding the link layer header.
1da177e4	58	*/
aaa4e704	59	static const struct neigh_ops dn_neigh_ops = {
1da177e4	60	.family = AF_DECnet,
aaa4e704 EB	61	.error_report = dn_neigh_error_report,
	62	.output = dn_neigh_output,
	63	.connected_output = dn_neigh_output,
1da177e4 LT	64	};
1da177e4 LT	65
d6bf7817 ED	66	static u32 dn_neigh_hash(const void *pkey,
d6bf7817 ED	67	const struct net_device *dev,
2c2aba6c	68	__u32 *hash_rnd)
d6bf7817	69	{
2c2aba6c	70	return jhash_2words((__u16 )pkey, 0, hash_rnd[0]);
d6bf7817 ED	71	}
d6bf7817 ED	72
60395a20 EB	73	static bool dn_key_eq(const struct neighbour neigh, const void pkey)
	74	{
	75	return neigh_key_eq16(neigh, pkey);
	76	}
	77
1da177e4 LT	78	struct neigh_table dn_neigh_table = {
1da177e4 LT	79	.family = PF_DECnet,
daaba4fa	80	.entry_size = NEIGH_ENTRY_SIZE(sizeof(struct dn_neigh)),
c4ea94ab	81	.key_len = sizeof(__le16),
bdf53c58	82	.protocol = cpu_to_be16(ETH_P_DNA_RT),
1da177e4	83	.hash = dn_neigh_hash,
60395a20	84	.key_eq = dn_key_eq,
1da177e4 LT	85	.constructor = dn_neigh_construct,
	86	.id = "dn_neigh_cache",
	87	.parms ={
	88	.tbl = &dn_neigh_table,
1f9248e5 JP	89	.reachable_time = 30 * HZ,
	90	.data = {
	91	[NEIGH_VAR_MCAST_PROBES] = 0,
	92	[NEIGH_VAR_UCAST_PROBES] = 0,
	93	[NEIGH_VAR_APP_PROBES] = 0,
	94	[NEIGH_VAR_RETRANS_TIME] = 1 * HZ,
	95	[NEIGH_VAR_BASE_REACHABLE_TIME] = 30 * HZ,
	96	[NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ,
	97	[NEIGH_VAR_GC_STALETIME] = 60 * HZ,
eaa72dc4	98	[NEIGH_VAR_QUEUE_LEN_BYTES] = SK_WMEM_MAX,
1f9248e5 JP	99	[NEIGH_VAR_PROXY_QLEN] = 0,
	100	[NEIGH_VAR_ANYCAST_DELAY] = 0,
	101	[NEIGH_VAR_PROXY_DELAY] = 0,
	102	[NEIGH_VAR_LOCKTIME] = 1 * HZ,
	103	},
1da177e4 LT	104	},
	105	.gc_interval = 30 * HZ,
	106	.gc_thresh1 = 128,
	107	.gc_thresh2 = 512,
	108	.gc_thresh3 = 1024,
	109	};
	110
1da177e4 LT	111	static int dn_neigh_construct(struct neighbour *neigh)
	112	{
	113	struct net_device *dev = neigh->dev;
f92ceb01	114	struct dn_neigh *dn = container_of(neigh, struct dn_neigh, n);
1da177e4 LT	115	struct dn_dev *dn_db;
	116	struct neigh_parms *parms;
	117
	118	rcu_read_lock();
	119	dn_db = rcu_dereference(dev->dn_ptr);
	120	if (dn_db == NULL) {
	121	rcu_read_unlock();
	122	return -EINVAL;
	123	}
	124
	125	parms = dn_db->neigh_parms;
	126	if (!parms) {
	127	rcu_read_unlock();
	128	return -EINVAL;
	129	}
	130
	131	__neigh_parms_put(neigh->parms);
	132	neigh->parms = neigh_parms_clone(parms);
1f07247d	133	rcu_read_unlock();
1da177e4	134
aaa4e704	135	neigh->ops = &dn_neigh_ops;
1da177e4 LT	136	neigh->nud_state = NUD_NOARP;
	137	neigh->output = neigh->ops->connected_output;
	138
	139	if ((dev->type == ARPHRD_IPGRE) \|\| (dev->flags & IFF_POINTOPOINT))
	140	memcpy(neigh->ha, dev->broadcast, dev->addr_len);
	141	else if ((dev->type == ARPHRD_ETHER) \|\| (dev->type == ARPHRD_LOOPBACK))
	142	dn_dn2eth(neigh->ha, dn->addr);
	143	else {
e87cc472 JP	144	net_dbg_ratelimited("Trying to create neigh for hw %d\n",
e87cc472 JP	145	dev->type);
1da177e4 LT	146	return -EINVAL;
	147	}
	148
	149	/*
	150	* Make an estimate of the remote block size by assuming that its
	151	* two less then the device mtu, which it true for ethernet (and
	152	* other things which support long format headers) since there is
	153	* an extra length field (of 16 bits) which isn't part of the
	154	* ethernet headers and which the DECnet specs won't admit is part
	155	* of the DECnet routing headers either.
	156	*
	157	* If we over estimate here its no big deal, the NSP negotiations
	158	* will prevent us from sending packets which are too large for the
	159	* remote node to handle. In any case this figure is normally updated
	160	* by a hello message in most cases.
	161	*/
	162	dn->blksize = dev->mtu - 2;
	163
	164	return 0;
	165	}
	166
aaa4e704	167	static void dn_neigh_error_report(struct neighbour neigh, struct sk_buff skb)
1da177e4	168	{
aaa4e704	169	printk(KERN_DEBUG "dn_neigh_error_report: called\n");
1da177e4 LT	170	kfree_skb(skb);
	171	}
	172
aaa4e704	173	static int dn_neigh_output(struct neighbour neigh, struct sk_buff skb)
1da177e4	174	{
adf30907	175	struct dst_entry *dst = skb_dst(skb);
1da177e4	176	struct dn_route rt = (struct dn_route )dst;
1da177e4 LT	177	struct net_device *dev = neigh->dev;
1da177e4 LT	178	char mac_addr[ETH_ALEN];
3329bdfc DM	179	unsigned int seq;
3329bdfc DM	180	int err;
1da177e4 LT	181
1da177e4 LT	182	dn_dn2eth(mac_addr, rt->rt_local_src);
3329bdfc DM	183	do {
	184	seq = read_seqbegin(&neigh->ha_lock);
	185	err = dev_hard_header(skb, dev, ntohs(skb->protocol),
	186	neigh->ha, mac_addr, skb->len);
	187	} while (read_seqretry(&neigh->ha_lock, seq));
	188
	189	if (err >= 0)
	190	err = dev_queue_xmit(skb);
	191	else {
	192	kfree_skb(skb);
	193	err = -EINVAL;
	194	}
	195	return err;
1da177e4 LT	196	}
1da177e4 LT	197
0c4b51f0	198	static int dn_neigh_output_packet(struct net net, struct sock sk, struct sk_buff *skb)
aaa4e704 EB	199	{
	200	struct dst_entry *dst = skb_dst(skb);
	201	struct dn_route rt = (struct dn_route )dst;
	202	struct neighbour *neigh = rt->n;
	203
	204	return neigh->output(neigh, skb);
	205	}
	206
	207	/*
	208	* For talking to broadcast devices: Ethernet & PPP
	209	*/
7026b1dd DM	210	static int dn_long_output(struct neighbour neigh, struct sock sk,
7026b1dd DM	211	struct sk_buff *skb)
1da177e4	212	{
1da177e4 LT	213	struct net_device *dev = neigh->dev;
	214	int headroom = dev->hard_header_len + sizeof(struct dn_long_packet) + 3;
	215	unsigned char *data;
	216	struct dn_long_packet *lp;
	217	struct dn_skb_cb *cb = DN_SKB_CB(skb);
	218
	219
	220	if (skb_headroom(skb) < headroom) {
	221	struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom);
	222	if (skb2 == NULL) {
e87cc472	223	net_crit_ratelimited("dn_long_output: no memory\n");
1da177e4 LT	224	kfree_skb(skb);
	225	return -ENOBUFS;
	226	}
5d0ba55b	227	consume_skb(skb);
1da177e4	228	skb = skb2;
e87cc472	229	net_info_ratelimited("dn_long_output: Increasing headroom\n");
1da177e4 LT	230	}
	231
	232	data = skb_push(skb, sizeof(struct dn_long_packet) + 3);
	233	lp = (struct dn_long_packet *)(data+3);
	234
c4106aa8	235	((__le16 )data) = cpu_to_le16(skb->len - 2);
1da177e4 LT	236	(data + 2) = 1 \| DN_RT_F_PF; / Padding */
	237
	238	lp->msgflg = DN_RT_PKT_LONG\|(cb->rt_flags&(DN_RT_F_IE\|DN_RT_F_RQR\|DN_RT_F_RTS));
	239	lp->d_area = lp->d_subarea = 0;
c4ea94ab	240	dn_dn2eth(lp->d_id, cb->dst);
1da177e4	241	lp->s_area = lp->s_subarea = 0;
c4ea94ab	242	dn_dn2eth(lp->s_id, cb->src);
1da177e4 LT	243	lp->nl2 = 0;
	244	lp->visit_ct = cb->hops & 0x3f;
	245	lp->s_class = 0;
	246	lp->pt = 0;
	247
c1d2bbe1	248	skb_reset_network_header(skb);
1da177e4	249
29a26a56 EB	250	return NF_HOOK(NFPROTO_DECNET, NF_DN_POST_ROUTING,
	251	&init_net, sk, skb, NULL, neigh->dev,
	252	dn_neigh_output_packet);
1da177e4 LT	253	}
1da177e4 LT	254
aaa4e704 EB	255	/*
	256	* For talking to pointopoint and multidrop devices: DDCMP and X.25
	257	*/
7026b1dd DM	258	static int dn_short_output(struct neighbour neigh, struct sock sk,
7026b1dd DM	259	struct sk_buff *skb)
1da177e4	260	{
1da177e4 LT	261	struct net_device *dev = neigh->dev;
	262	int headroom = dev->hard_header_len + sizeof(struct dn_short_packet) + 2;
	263	struct dn_short_packet *sp;
	264	unsigned char *data;
	265	struct dn_skb_cb *cb = DN_SKB_CB(skb);
	266
	267
429eb0fa YH	268	if (skb_headroom(skb) < headroom) {
	269	struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom);
	270	if (skb2 == NULL) {
e87cc472	271	net_crit_ratelimited("dn_short_output: no memory\n");
429eb0fa YH	272	kfree_skb(skb);
	273	return -ENOBUFS;
	274	}
5d0ba55b	275	consume_skb(skb);
429eb0fa	276	skb = skb2;
e87cc472	277	net_info_ratelimited("dn_short_output: Increasing headroom\n");
429eb0fa	278	}
1da177e4 LT	279
1da177e4 LT	280	data = skb_push(skb, sizeof(struct dn_short_packet) + 2);
c4106aa8	281	((__le16 )data) = cpu_to_le16(skb->len - 2);
1da177e4 LT	282	sp = (struct dn_short_packet *)(data+2);
	283
	284	sp->msgflg = DN_RT_PKT_SHORT\|(cb->rt_flags&(DN_RT_F_RQR\|DN_RT_F_RTS));
	285	sp->dstnode = cb->dst;
	286	sp->srcnode = cb->src;
	287	sp->forward = cb->hops & 0x3f;
	288
c1d2bbe1	289	skb_reset_network_header(skb);
1da177e4	290
29a26a56 EB	291	return NF_HOOK(NFPROTO_DECNET, NF_DN_POST_ROUTING,
	292	&init_net, sk, skb, NULL, neigh->dev,
	293	dn_neigh_output_packet);
1da177e4 LT	294	}
	295
	296	/*
aaa4e704 EB	297	* For talking to DECnet phase III nodes
aaa4e704 EB	298	* Phase 3 output is the same as short output, execpt that
1da177e4 LT	299	* it clears the area bits before transmission.
1da177e4 LT	300	*/
7026b1dd DM	301	static int dn_phase3_output(struct neighbour neigh, struct sock sk,
7026b1dd DM	302	struct sk_buff *skb)
1da177e4	303	{
1da177e4 LT	304	struct net_device *dev = neigh->dev;
	305	int headroom = dev->hard_header_len + sizeof(struct dn_short_packet) + 2;
	306	struct dn_short_packet *sp;
	307	unsigned char *data;
	308	struct dn_skb_cb *cb = DN_SKB_CB(skb);
	309
	310	if (skb_headroom(skb) < headroom) {
	311	struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom);
	312	if (skb2 == NULL) {
e87cc472	313	net_crit_ratelimited("dn_phase3_output: no memory\n");
1da177e4 LT	314	kfree_skb(skb);
	315	return -ENOBUFS;
	316	}
5d0ba55b	317	consume_skb(skb);
1da177e4	318	skb = skb2;
e87cc472	319	net_info_ratelimited("dn_phase3_output: Increasing headroom\n");
1da177e4 LT	320	}
	321
	322	data = skb_push(skb, sizeof(struct dn_short_packet) + 2);
c4106aa8	323	((__le16 )data) = cpu_to_le16(skb->len - 2);
1da177e4 LT	324	sp = (struct dn_short_packet *)(data + 2);
	325
	326	sp->msgflg = DN_RT_PKT_SHORT\|(cb->rt_flags&(DN_RT_F_RQR\|DN_RT_F_RTS));
c4106aa8 HH	327	sp->dstnode = cb->dst & cpu_to_le16(0x03ff);
c4106aa8 HH	328	sp->srcnode = cb->src & cpu_to_le16(0x03ff);
1da177e4 LT	329	sp->forward = cb->hops & 0x3f;
1da177e4 LT	330
c1d2bbe1	331	skb_reset_network_header(skb);
1da177e4	332
29a26a56 EB	333	return NF_HOOK(NFPROTO_DECNET, NF_DN_POST_ROUTING,
	334	&init_net, sk, skb, NULL, neigh->dev,
	335	dn_neigh_output_packet);
1da177e4 LT	336	}
1da177e4 LT	337
0c4b51f0	338	int dn_to_neigh_output(struct net net, struct sock sk, struct sk_buff *skb)
aaa4e704 EB	339	{
	340	struct dst_entry *dst = skb_dst(skb);
	341	struct dn_route rt = (struct dn_route ) dst;
	342	struct neighbour *neigh = rt->n;
f92ceb01	343	struct dn_neigh *dn = container_of(neigh, struct dn_neigh, n);
aaa4e704 EB	344	struct dn_dev *dn_db;
	345	bool use_long;
	346
	347	rcu_read_lock();
	348	dn_db = rcu_dereference(neigh->dev->dn_ptr);
	349	if (dn_db == NULL) {
	350	rcu_read_unlock();
	351	return -EINVAL;
	352	}
	353	use_long = dn_db->use_long;
	354	rcu_read_unlock();
	355
	356	if (dn->flags & DN_NDFLAG_P3)
7026b1dd	357	return dn_phase3_output(neigh, sk, skb);
aaa4e704	358	if (use_long)
7026b1dd	359	return dn_long_output(neigh, sk, skb);
aaa4e704	360	else
7026b1dd	361	return dn_short_output(neigh, sk, skb);
aaa4e704 EB	362	}
aaa4e704 EB	363
1da177e4 LT	364	/*
	365	* Unfortunately, the neighbour code uses the device in its hash
	366	* function, so we don't get any advantage from it. This function
	367	* basically does a neigh_lookup(), but without comparing the device
	368	* field. This is required for the On-Ethernet cache
	369	*/
	370
	371	/*
	372	* Pointopoint link receives a hello message
	373	*/
	374	void dn_neigh_pointopoint_hello(struct sk_buff *skb)
	375	{
	376	kfree_skb(skb);
	377	}
	378
	379	/*
	380	* Ethernet router hello message received
	381	*/
0c4b51f0	382	int dn_neigh_router_hello(struct net net, struct sock sk, struct sk_buff *skb)
1da177e4 LT	383	{
	384	struct rtnode_hello_message msg = (struct rtnode_hello_message )skb->data;
	385
	386	struct neighbour *neigh;
	387	struct dn_neigh *dn;
	388	struct dn_dev *dn_db;
c4ea94ab	389	__le16 src;
1da177e4	390
c4ea94ab	391	src = dn_eth2dn(msg->id);
1da177e4 LT	392
	393	neigh = __neigh_lookup(&dn_neigh_table, &src, skb->dev, 1);
	394
f92ceb01	395	dn = container_of(neigh, struct dn_neigh, n);
1da177e4 LT	396
	397	if (neigh) {
	398	write_lock(&neigh->lock);
	399
	400	neigh->used = jiffies;
fc766e4c	401	dn_db = rcu_dereference(neigh->dev->dn_ptr);
1da177e4 LT	402
	403	if (!(neigh->nud_state & NUD_PERMANENT)) {
	404	neigh->updated = jiffies;
	405
	406	if (neigh->dev->type == ARPHRD_ETHER)
	407	memcpy(neigh->ha, &eth_hdr(skb)->h_source, ETH_ALEN);
	408
c4106aa8	409	dn->blksize = le16_to_cpu(msg->blksize);
1da177e4 LT	410	dn->priority = msg->priority;
	411
	412	dn->flags &= ~DN_NDFLAG_P3;
	413
06f8fe11 JP	414	switch (msg->iinfo & DN_RT_INFO_TYPE) {
	415	case DN_RT_INFO_L1RT:
	416	dn->flags &=~DN_NDFLAG_R2;
	417	dn->flags \|= DN_NDFLAG_R1;
	418	break;
	419	case DN_RT_INFO_L2RT:
	420	dn->flags \|= DN_NDFLAG_R2;
1da177e4 LT	421	}
	422	}
	423
5062430c	424	/* Only use routers in our area */
c4106aa8	425	if ((le16_to_cpu(src)>>10) == (le16_to_cpu((decnet_address))>>10)) {
5062430c PC	426	if (!dn_db->router) {
	427	dn_db->router = neigh_clone(neigh);
	428	} else {
	429	if (msg->priority > ((struct dn_neigh *)dn_db->router)->priority)
	430	neigh_release(xchg(&dn_db->router, neigh_clone(neigh)));
	431	}
1da177e4 LT	432	}
	433	write_unlock(&neigh->lock);
	434	neigh_release(neigh);
	435	}
	436
	437	kfree_skb(skb);
	438	return 0;
	439	}
	440
	441	/*
	442	* Endnode hello message received
	443	*/
0c4b51f0	444	int dn_neigh_endnode_hello(struct net net, struct sock sk, struct sk_buff *skb)
1da177e4 LT	445	{
	446	struct endnode_hello_message msg = (struct endnode_hello_message )skb->data;
	447	struct neighbour *neigh;
	448	struct dn_neigh *dn;
c4ea94ab	449	__le16 src;
1da177e4	450
c4ea94ab	451	src = dn_eth2dn(msg->id);
1da177e4 LT	452
	453	neigh = __neigh_lookup(&dn_neigh_table, &src, skb->dev, 1);
	454
f92ceb01	455	dn = container_of(neigh, struct dn_neigh, n);
1da177e4 LT	456
	457	if (neigh) {
	458	write_lock(&neigh->lock);
	459
	460	neigh->used = jiffies;
	461
	462	if (!(neigh->nud_state & NUD_PERMANENT)) {
	463	neigh->updated = jiffies;
	464
	465	if (neigh->dev->type == ARPHRD_ETHER)
	466	memcpy(neigh->ha, &eth_hdr(skb)->h_source, ETH_ALEN);
	467	dn->flags &= ~(DN_NDFLAG_R1 \| DN_NDFLAG_R2);
c4106aa8	468	dn->blksize = le16_to_cpu(msg->blksize);
1da177e4 LT	469	dn->priority = 0;
	470	}
	471
	472	write_unlock(&neigh->lock);
	473	neigh_release(neigh);
	474	}
	475
	476	kfree_skb(skb);
	477	return 0;
	478	}
	479
	480	static char dn_find_slot(char base, int max, int priority)
	481	{
	482	int i;
	483	unsigned char *min = NULL;
	484
	485	base += 6; /* skip first id */
	486
	487	for(i = 0; i < max; i++) {
	488	if (!min \|\| (base < min))
	489	min = base;
	490	base += 7; /* find next priority */
	491	}
	492
	493	if (!min)
	494	return NULL;
	495
	496	return (*min < priority) ? (min - 6) : NULL;
	497	}
	498
	499	struct elist_cb_state {
	500	struct net_device *dev;
	501	unsigned char *ptr;
	502	unsigned char *rs;
	503	int t, n;
	504	};
	505
	506	static void neigh_elist_cb(struct neighbour neigh, void _info)
	507	{
	508	struct elist_cb_state *s = _info;
1da177e4 LT	509	struct dn_neigh *dn;
	510
	511	if (neigh->dev != s->dev)
	512	return;
	513
f92ceb01	514	dn = container_of(neigh, struct dn_neigh, n);
1da177e4 LT	515	if (!(dn->flags & (DN_NDFLAG_R1\|DN_NDFLAG_R2)))
	516	return;
	517
1da177e4 LT	518	if (s->t == s->n)
	519	s->rs = dn_find_slot(s->ptr, s->n, dn->priority);
	520	else
	521	s->t++;
	522	if (s->rs == NULL)
	523	return;
	524
	525	dn_dn2eth(s->rs, dn->addr);
	526	s->rs += 6;
	527	*(s->rs) = neigh->nud_state & NUD_CONNECTED ? 0x80 : 0x0;
	528	*(s->rs) \|= dn->priority;
	529	s->rs++;
	530	}
	531
	532	int dn_neigh_elist(struct net_device dev, unsigned char ptr, int n)
	533	{
	534	struct elist_cb_state state;
	535
	536	state.dev = dev;
	537	state.t = 0;
	538	state.n = n;
	539	state.ptr = ptr;
	540	state.rs = ptr;
	541
	542	neigh_for_each(&dn_neigh_table, neigh_elist_cb, &state);
	543
	544	return state.t;
	545	}
	546
	547
	548	#ifdef CONFIG_PROC_FS
	549
	550	static inline void dn_neigh_format_entry(struct seq_file *seq,
	551	struct neighbour *n)
	552	{
f92ceb01	553	struct dn_neigh *dn = container_of(n, struct dn_neigh, n);
1da177e4 LT	554	char buf[DN_ASCBUF_LEN];
	555
	556	read_lock(&n->lock);
	557	seq_printf(seq, "%-7s %s%s%s %02x %02d %07ld %-8s\n",
c4106aa8	558	dn_addr2asc(le16_to_cpu(dn->addr), buf),
1da177e4 LT	559	(dn->flags&DN_NDFLAG_R1) ? "1" : "-",
	560	(dn->flags&DN_NDFLAG_R2) ? "2" : "-",
	561	(dn->flags&DN_NDFLAG_P3) ? "3" : "-",
	562	dn->n.nud_state,
9f237430	563	refcount_read(&dn->n.refcnt),
1da177e4 LT	564	dn->blksize,
	565	(dn->n.dev) ? dn->n.dev->name : "?");
	566	read_unlock(&n->lock);
	567	}
	568
	569	static int dn_neigh_seq_show(struct seq_file seq, void v)
	570	{
	571	if (v == SEQ_START_TOKEN) {
	572	seq_puts(seq, "Addr Flags State Use Blksize Dev\n");
	573	} else {
	574	dn_neigh_format_entry(seq, v);
	575	}
	576
	577	return 0;
	578	}
	579
	580	static void dn_neigh_seq_start(struct seq_file seq, loff_t *pos)
	581	{
	582	return neigh_seq_start(seq, pos, &dn_neigh_table,
	583	NEIGH_SEQ_NEIGH_ONLY);
	584	}
	585
56b3d975	586	static const struct seq_operations dn_neigh_seq_ops = {
1da177e4 LT	587	.start = dn_neigh_seq_start,
	588	.next = neigh_seq_next,
	589	.stop = neigh_seq_stop,
	590	.show = dn_neigh_seq_show,
	591	};
	592
	593	static int dn_neigh_seq_open(struct inode inode, struct file file)
	594	{
426b5303 EB	595	return seq_open_net(inode, file, &dn_neigh_seq_ops,
426b5303 EB	596	sizeof(struct neigh_seq_state));
1da177e4 LT	597	}
1da177e4 LT	598
9a32144e	599	static const struct file_operations dn_neigh_seq_fops = {
1da177e4 LT	600	.owner = THIS_MODULE,
	601	.open = dn_neigh_seq_open,
	602	.read = seq_read,
	603	.llseek = seq_lseek,
426b5303	604	.release = seq_release_net,
1da177e4 LT	605	};
	606
	607	#endif
	608
	609	void __init dn_neigh_init(void)
	610	{
d7480fd3	611	neigh_table_init(NEIGH_DN_TABLE, &dn_neigh_table);
d4beaa66 G	612	proc_create("decnet_neigh", S_IRUGO, init_net.proc_net,
d4beaa66 G	613	&dn_neigh_seq_fops);
1da177e4 LT	614	}
	615
	616	void __exit dn_neigh_cleanup(void)
	617	{
ece31ffd	618	remove_proc_entry("decnet_neigh", init_net.proc_net);
d7480fd3	619	neigh_table_clear(NEIGH_DN_TABLE, &dn_neigh_table);
1da177e4	620	}