neighbour.c

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	if (tbl->proxy_queue.qlen > p->proxy_qlen) {
		kfree_skb(skb);
		return;
	}
	skb->stamp.tv_sec = 0;
	skb->stamp.tv_usec = now + sched_next;

	spin_lock(&tbl->proxy_queue.lock);
	if (del_timer(&tbl->proxy_timer)) {
		long tval = tbl->proxy_timer.expires - now;
		if (tval < sched_next)
			sched_next = tval;
	}
	dst_release(skb->dst);
	skb->dst = NULL;
	dev_hold(skb->dev);
	__skb_queue_tail(&tbl->proxy_queue, skb);
	mod_timer(&tbl->proxy_timer, now + sched_next);
	spin_unlock(&tbl->proxy_queue.lock);
}


struct neigh_parms *neigh_parms_alloc(struct net_device *dev, struct neigh_table *tbl)
{
	struct neigh_parms *p;
	p = kmalloc(sizeof(*p), GFP_KERNEL);
	if (p) {
		memcpy(p, &tbl->parms, sizeof(*p));
		p->tbl = tbl;
		p->reachable_time = neigh_rand_reach_time(p->base_reachable_time);
		if (dev && dev->neigh_setup) {
			if (dev->neigh_setup(dev, p)) {
				kfree(p);
				return NULL;
			}
		}
		write_lock_bh(&tbl->lock);
		p->next = tbl->parms.next;
		tbl->parms.next = p;
		write_unlock_bh(&tbl->lock);
	}
	return p;
}

void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms)
{
	struct neigh_parms **p;
	
	if (parms == NULL || parms == &tbl->parms)
		return;
	write_lock_bh(&tbl->lock);
	for (p = &tbl->parms.next; *p; p = &(*p)->next) {
		if (*p == parms) {
			*p = parms->next;
			write_unlock_bh(&tbl->lock);
#ifdef CONFIG_SYSCTL
			neigh_sysctl_unregister(parms);
#endif
			kfree(parms);
			return;
		}
	}
	write_unlock_bh(&tbl->lock);
	NEIGH_PRINTK1("neigh_parms_release: not found\n");
}


void neigh_table_init(struct neigh_table *tbl)
{
	unsigned long now = jiffies;

	tbl->parms.reachable_time = neigh_rand_reach_time(tbl->parms.base_reachable_time);

	if (tbl->kmem_cachep == NULL)
		tbl->kmem_cachep = kmem_cache_create(tbl->id,
						     (tbl->entry_size+15)&~15,
						     0, SLAB_HWCACHE_ALIGN,
						     NULL, NULL);

#ifdef CONFIG_SMP
	tasklet_init(&tbl->gc_task, SMP_TIMER_NAME(neigh_periodic_timer), (unsigned long)tbl);
#endif
	init_timer(&tbl->gc_timer);
	tbl->lock = RW_LOCK_UNLOCKED;
	tbl->gc_timer.data = (unsigned long)tbl;
	tbl->gc_timer.function = neigh_periodic_timer;
	tbl->gc_timer.expires = now + tbl->gc_interval + tbl->parms.reachable_time;
	add_timer(&tbl->gc_timer);

	init_timer(&tbl->proxy_timer);
	tbl->proxy_timer.data = (unsigned long)tbl;
	tbl->proxy_timer.function = neigh_proxy_process;
	skb_queue_head_init(&tbl->proxy_queue);

	tbl->last_flush = now;
	tbl->last_rand = now + tbl->parms.reachable_time*20;
	write_lock(&neigh_tbl_lock);
	tbl->next = neigh_tables;
	neigh_tables = tbl;
	write_unlock(&neigh_tbl_lock);
}

int neigh_table_clear(struct neigh_table *tbl)
{
	struct neigh_table **tp;

	/* It is not clean... Fix it to unload IPv6 module safely */
	del_timer_sync(&tbl->gc_timer);
	tasklet_kill(&tbl->gc_task);
	del_timer_sync(&tbl->proxy_timer);
	pneigh_queue_purge(&tbl->proxy_queue);
	neigh_ifdown(tbl, NULL);
	if (tbl->entries)
		printk(KERN_CRIT "neighbour leakage\n");
	write_lock(&neigh_tbl_lock);
	for (tp = &neigh_tables; *tp; tp = &(*tp)->next) {
		if (*tp == tbl) {
			*tp = tbl->next;
			break;
		}
	}
	write_unlock(&neigh_tbl_lock);
#ifdef CONFIG_SYSCTL
	neigh_sysctl_unregister(&tbl->parms);
#endif
	return 0;
}

int neigh_delete(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
{
	struct ndmsg *ndm = NLMSG_DATA(nlh);
	struct rtattr **nda = arg;
	struct neigh_table *tbl;
	struct net_device *dev = NULL;
	int err = 0;

	if (ndm->ndm_ifindex) {
		if ((dev = dev_get_by_index(ndm->ndm_ifindex)) == NULL)
			return -ENODEV;
	}

	read_lock(&neigh_tbl_lock);
	for (tbl=neigh_tables; tbl; tbl = tbl->next) {
		struct neighbour *n;

		if (tbl->family != ndm->ndm_family)
			continue;
		read_unlock(&neigh_tbl_lock);

		err = -EINVAL;
		if (nda[NDA_DST-1] == NULL ||
		    nda[NDA_DST-1]->rta_len != RTA_LENGTH(tbl->key_len))
			goto out;

		if (ndm->ndm_flags&NTF_PROXY) {
			err = pneigh_delete(tbl, RTA_DATA(nda[NDA_DST-1]), dev);
			goto out;
		}

		if (dev == NULL)
			return -EINVAL;

		n = neigh_lookup(tbl, RTA_DATA(nda[NDA_DST-1]), dev);
		if (n) {
			err = neigh_update(n, NULL, NUD_FAILED, 1, 0);
			neigh_release(n);
		}
out:
		if (dev)
			dev_put(dev);
		return err;
	}
	read_unlock(&neigh_tbl_lock);

	if (dev)
		dev_put(dev);

	return -EADDRNOTAVAIL;
}

int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
{
	struct ndmsg *ndm = NLMSG_DATA(nlh);
	struct rtattr **nda = arg;
	struct neigh_table *tbl;
	struct net_device *dev = NULL;

	if (ndm->ndm_ifindex) {
		if ((dev = dev_get_by_index(ndm->ndm_ifindex)) == NULL)
			return -ENODEV;
	}

	read_lock(&neigh_tbl_lock);
	for (tbl=neigh_tables; tbl; tbl = tbl->next) {
		int err = 0;
		struct neighbour *n;

		if (tbl->family != ndm->ndm_family)
			continue;
		read_unlock(&neigh_tbl_lock);

		err = -EINVAL;
		if (nda[NDA_DST-1] == NULL ||
		    nda[NDA_DST-1]->rta_len != RTA_LENGTH(tbl->key_len))
			goto out;
		if (ndm->ndm_flags&NTF_PROXY) {
			err = -ENOBUFS;
			if (pneigh_lookup(tbl, RTA_DATA(nda[NDA_DST-1]), dev, 1))
				err = 0;
			goto out;
		}
		if (dev == NULL)
			return -EINVAL;
		err = -EINVAL;
		if (nda[NDA_LLADDR-1] != NULL &&
		    nda[NDA_LLADDR-1]->rta_len != RTA_LENGTH(dev->addr_len))
			goto out;
		err = 0;
		n = neigh_lookup(tbl, RTA_DATA(nda[NDA_DST-1]), dev);
		if (n) {
			if (nlh->nlmsg_flags&NLM_F_EXCL)
				err = -EEXIST;
		} else if (!(nlh->nlmsg_flags&NLM_F_CREATE))
			err = -ENOENT;
		else {
			n = __neigh_lookup_errno(tbl, RTA_DATA(nda[NDA_DST-1]), dev);
			if (IS_ERR(n)) {
				err = PTR_ERR(n);
				n = NULL;
			}
		}
		if (err == 0) {
			err = neigh_update(n, nda[NDA_LLADDR-1] ? RTA_DATA(nda[NDA_LLADDR-1]) : NULL,
					   ndm->ndm_state,
					   nlh->nlmsg_flags&NLM_F_REPLACE, 0);
		}
		if (n)
			neigh_release(n);
out:
		if (dev)
			dev_put(dev);
		return err;
	}
	read_unlock(&neigh_tbl_lock);

	if (dev)
		dev_put(dev);
	return -EADDRNOTAVAIL;
}


static int neigh_fill_info(struct sk_buff *skb, struct neighbour *n,
			   u32 pid, u32 seq, int event)
{
	unsigned long now = jiffies;
	struct ndmsg *ndm;
	struct nlmsghdr  *nlh;
	unsigned char	 *b = skb->tail;
	struct nda_cacheinfo ci;
	int locked = 0;

	nlh = NLMSG_PUT(skb, pid, seq, event, sizeof(*ndm));
	ndm = NLMSG_DATA(nlh);
	ndm->ndm_family = n->ops->family;
	ndm->ndm_flags = n->flags;
	ndm->ndm_type = n->type;
	ndm->ndm_ifindex = n->dev->ifindex;
	RTA_PUT(skb, NDA_DST, n->tbl->key_len, n->primary_key);
	read_lock_bh(&n->lock);
	locked=1;
	ndm->ndm_state = n->nud_state;
	if (n->nud_state&NUD_VALID)
		RTA_PUT(skb, NDA_LLADDR, n->dev->addr_len, n->ha);
	ci.ndm_used = now - n->used;
	ci.ndm_confirmed = now - n->confirmed;
	ci.ndm_updated = now - n->updated;
	ci.ndm_refcnt = atomic_read(&n->refcnt) - 1;
	read_unlock_bh(&n->lock);
	locked=0;
	RTA_PUT(skb, NDA_CACHEINFO, sizeof(ci), &ci);
	nlh->nlmsg_len = skb->tail - b;
	return skb->len;

nlmsg_failure:
rtattr_failure:
	if (locked)
		read_unlock_bh(&n->lock);
	skb_trim(skb, b - skb->data);
	return -1;
}


static int neigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb, struct netlink_callback *cb)
{
	struct neighbour *n;
	int h, s_h;
	int idx, s_idx;

	s_h = cb->args[1];
	s_idx = idx = cb->args[2];
	for (h=0; h <= NEIGH_HASHMASK; h++) {
		if (h < s_h) continue;
		if (h > s_h)
			s_idx = 0;
		read_lock_bh(&tbl->lock);
		for (n = tbl->hash_buckets[h], idx = 0; n;
		     n = n->next, idx++) {
			if (idx < s_idx)
				continue;
			if (neigh_fill_info(skb, n, NETLINK_CB(cb->skb).pid,
					    cb->nlh->nlmsg_seq, RTM_NEWNEIGH) <= 0) {
				read_unlock_bh(&tbl->lock);
				cb->args[1] = h;
				cb->args[2] = idx;
				return -1;
			}
		}
		read_unlock_bh(&tbl->lock);
	}

	cb->args[1] = h;
	cb->args[2] = idx;
	return skb->len;
}

int neigh_dump_info(struct sk_buff *skb, struct netlink_callback *cb)
{
	int t;
	int s_t;
	struct neigh_table *tbl;
	int family = ((struct rtgenmsg*)NLMSG_DATA(cb->nlh))->rtgen_family;

	s_t = cb->args[0];

	read_lock(&neigh_tbl_lock);
	for (tbl=neigh_tables, t=0; tbl; tbl = tbl->next, t++) {
		if (t < s_t) continue;
		if (family && tbl->family != family)
			continue;
		if (t > s_t)
			memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
		if (neigh_dump_table(tbl, skb, cb) < 0) 
			break;
	}
	read_unlock(&neigh_tbl_lock);

	cb->args[0] = t;

	return skb->len;
}

#ifdef CONFIG_ARPD
void neigh_app_ns(struct neighbour *n)
{
	struct sk_buff *skb;
	struct nlmsghdr  *nlh;
	int size = NLMSG_SPACE(sizeof(struct ndmsg)+256);

	skb = alloc_skb(size, GFP_ATOMIC);
	if (!skb)
		return;

	if (neigh_fill_info(skb, n, 0, 0, RTM_GETNEIGH) < 0) {
		kfree_skb(skb);
		return;
	}
	nlh = (struct nlmsghdr*)skb->data;
	nlh->nlmsg_flags = NLM_F_REQUEST;
	NETLINK_CB(skb).dst_groups = RTMGRP_NEIGH;
	netlink_broadcast(rtnl, skb, 0, RTMGRP_NEIGH, GFP_ATOMIC);
}

static void neigh_app_notify(struct neighbour *n)
{
	struct sk_buff *skb;
	struct nlmsghdr  *nlh;
	int size = NLMSG_SPACE(sizeof(struct ndmsg)+256);

	skb = alloc_skb(size, GFP_ATOMIC);
	if (!skb)
		return;

	if (neigh_fill_info(skb, n, 0, 0, RTM_NEWNEIGH) < 0) {
		kfree_skb(skb);
		return;
	}
	nlh = (struct nlmsghdr*)skb->data;
	NETLINK_CB(skb).dst_groups = RTMGRP_NEIGH;
	netlink_broadcast(rtnl, skb, 0, RTMGRP_NEIGH, GFP_ATOMIC);
}

#endif /* CONFIG_ARPD */

#ifdef CONFIG_SYSCTL

struct neigh_sysctl_table
{
	struct ctl_table_header *sysctl_header;
	ctl_table neigh_vars[17];
	ctl_table neigh_dev[2];
	ctl_table neigh_neigh_dir[2];
	ctl_table neigh_proto_dir[2];
	ctl_table neigh_root_dir[2];
} neigh_sysctl_template = {
	NULL,
        {{NET_NEIGH_MCAST_SOLICIT, "mcast_solicit",
         NULL, sizeof(int), 0644, NULL,
         &proc_dointvec},
	{NET_NEIGH_UCAST_SOLICIT, "ucast_solicit",
         NULL, sizeof(int), 0644, NULL,
         &proc_dointvec},
	{NET_NEIGH_APP_SOLICIT, "app_solicit",
         NULL, sizeof(int), 0644, NULL,
         &proc_dointvec},
	{NET_NEIGH_RETRANS_TIME, "retrans_time",
         NULL, sizeof(int), 0644, NULL,
         &proc_dointvec},
	{NET_NEIGH_REACHABLE_TIME, "base_reachable_time",
         NULL, sizeof(int), 0644, NULL,
         &proc_dointvec_jiffies},
	{NET_NEIGH_DELAY_PROBE_TIME, "delay_first_probe_time",
         NULL, sizeof(int), 0644, NULL,
         &proc_dointvec_jiffies},
	{NET_NEIGH_GC_STALE_TIME, "gc_stale_time",
         NULL, sizeof(int), 0644, NULL,
         &proc_dointvec_jiffies},
	{NET_NEIGH_UNRES_QLEN, "unres_qlen",
         NULL, sizeof(int), 0644, NULL,
         &proc_dointvec},
	{NET_NEIGH_PROXY_QLEN, "proxy_qlen",
         NULL, sizeof(int), 0644, NULL,
         &proc_dointvec},
	{NET_NEIGH_ANYCAST_DELAY, "anycast_delay",
         NULL, sizeof(int), 0644, NULL,
         &proc_dointvec},
	{NET_NEIGH_PROXY_DELAY, "proxy_delay",
         NULL, sizeof(int), 0644, NULL,
         &proc_dointvec},
	{NET_NEIGH_LOCKTIME, "locktime",
         NULL, sizeof(int), 0644, NULL,
         &proc_dointvec},
	{NET_NEIGH_GC_INTERVAL, "gc_interval",
         NULL, sizeof(int), 0644, NULL,
         &proc_dointvec_jiffies},
	{NET_NEIGH_GC_THRESH1, "gc_thresh1",
         NULL, sizeof(int), 0644, NULL,
         &proc_dointvec},
	{NET_NEIGH_GC_THRESH2, "gc_thresh2",
         NULL, sizeof(int), 0644, NULL,
         &proc_dointvec},
	{NET_NEIGH_GC_THRESH3, "gc_thresh3",
         NULL, sizeof(int), 0644, NULL,
         &proc_dointvec},
	 {0}},

	{{NET_PROTO_CONF_DEFAULT, "default", NULL, 0, 0555, NULL},{0}},
	{{0, "neigh", NULL, 0, 0555, NULL},{0}},
	{{0, NULL, NULL, 0, 0555, NULL},{0}},
	{{CTL_NET, "net", NULL, 0, 0555, NULL},{0}}
};

int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p,
			  int p_id, int pdev_id, char *p_name)
{
	struct neigh_sysctl_table *t;

	t = kmalloc(sizeof(*t), GFP_KERNEL);
	if (t == NULL)
		return -ENOBUFS;
	memcpy(t, &neigh_sysctl_template, sizeof(*t));
	t->neigh_vars[0].data = &p->mcast_probes;
	t->neigh_vars[1].data = &p->ucast_probes;
	t->neigh_vars[2].data = &p->app_probes;
	t->neigh_vars[3].data = &p->retrans_time;
	t->neigh_vars[4].data = &p->base_reachable_time;
	t->neigh_vars[5].data = &p->delay_probe_time;
	t->neigh_vars[6].data = &p->gc_staletime;
	t->neigh_vars[7].data = &p->queue_len;
	t->neigh_vars[8].data = &p->proxy_qlen;
	t->neigh_vars[9].data = &p->anycast_delay;
	t->neigh_vars[10].data = &p->proxy_delay;
	t->neigh_vars[11].data = &p->locktime;
	if (dev) {
		t->neigh_dev[0].procname = dev->name;
		t->neigh_dev[0].ctl_name = dev->ifindex;
		memset(&t->neigh_vars[12], 0, sizeof(ctl_table));
	} else {
		t->neigh_vars[12].data = (int*)(p+1);
		t->neigh_vars[13].data = (int*)(p+1) + 1;
		t->neigh_vars[14].data = (int*)(p+1) + 2;
		t->neigh_vars[15].data = (int*)(p+1) + 3;
	}
	t->neigh_neigh_dir[0].ctl_name = pdev_id;

	t->neigh_proto_dir[0].procname = p_name;
	t->neigh_proto_dir[0].ctl_name = p_id;

	t->neigh_dev[0].child = t->neigh_vars;
	t->neigh_neigh_dir[0].child = t->neigh_dev;
	t->neigh_proto_dir[0].child = t->neigh_neigh_dir;
	t->neigh_root_dir[0].child = t->neigh_proto_dir;

	t->sysctl_header = register_sysctl_table(t->neigh_root_dir, 0);
	if (t->sysctl_header == NULL) {
		kfree(t);
		return -ENOBUFS;
	}
	p->sysctl_table = t;
	return 0;
}

void neigh_sysctl_unregister(struct neigh_parms *p)
{
	if (p->sysctl_table) {
		struct neigh_sysctl_table *t = p->sysctl_table;
		p->sysctl_table = NULL;
		unregister_sysctl_table(t->sysctl_header);
		kfree(t);
	}
}

#endif	/* CONFIG_SYSCTL */