neighbour.c

linux 内核源代码

	}
	return *pos ? NULL : n;
}

static struct pneigh_entry *pneigh_get_first(struct seq_file *seq)
{
	struct neigh_seq_state *state = seq->private;
	struct neigh_table *tbl = state->tbl;
	struct pneigh_entry *pn = NULL;
	int bucket = state->bucket;

	state->flags |= NEIGH_SEQ_IS_PNEIGH;
	for (bucket = 0; bucket <= PNEIGH_HASHMASK; bucket++) {
		pn = tbl->phash_buckets[bucket];
		if (pn)
			break;
	}
	state->bucket = bucket;

	return pn;
}

static struct pneigh_entry *pneigh_get_next(struct seq_file *seq,
					    struct pneigh_entry *pn,
					    loff_t *pos)
{
	struct neigh_seq_state *state = seq->private;
	struct neigh_table *tbl = state->tbl;

	pn = pn->next;
	while (!pn) {
		if (++state->bucket > PNEIGH_HASHMASK)
			break;
		pn = tbl->phash_buckets[state->bucket];
		if (pn)
			break;
	}

	if (pn && pos)
		--(*pos);

	return pn;
}

static struct pneigh_entry *pneigh_get_idx(struct seq_file *seq, loff_t *pos)
{
	struct pneigh_entry *pn = pneigh_get_first(seq);

	if (pn) {
		while (*pos) {
			pn = pneigh_get_next(seq, pn, pos);
			if (!pn)
				break;
		}
	}
	return *pos ? NULL : pn;
}

static void *neigh_get_idx_any(struct seq_file *seq, loff_t *pos)
{
	struct neigh_seq_state *state = seq->private;
	void *rc;

	rc = neigh_get_idx(seq, pos);
	if (!rc && !(state->flags & NEIGH_SEQ_NEIGH_ONLY))
		rc = pneigh_get_idx(seq, pos);

	return rc;
}

void *neigh_seq_start(struct seq_file *seq, loff_t *pos, struct neigh_table *tbl, unsigned int neigh_seq_flags)
{
	struct neigh_seq_state *state = seq->private;
	loff_t pos_minus_one;

	state->tbl = tbl;
	state->bucket = 0;
	state->flags = (neigh_seq_flags & ~NEIGH_SEQ_IS_PNEIGH);

	read_lock_bh(&tbl->lock);

	pos_minus_one = *pos - 1;
	return *pos ? neigh_get_idx_any(seq, &pos_minus_one) : SEQ_START_TOKEN;
}
EXPORT_SYMBOL(neigh_seq_start);

void *neigh_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
	struct neigh_seq_state *state;
	void *rc;

	if (v == SEQ_START_TOKEN) {
		rc = neigh_get_idx(seq, pos);
		goto out;
	}

	state = seq->private;
	if (!(state->flags & NEIGH_SEQ_IS_PNEIGH)) {
		rc = neigh_get_next(seq, v, NULL);
		if (rc)
			goto out;
		if (!(state->flags & NEIGH_SEQ_NEIGH_ONLY))
			rc = pneigh_get_first(seq);
	} else {
		BUG_ON(state->flags & NEIGH_SEQ_NEIGH_ONLY);
		rc = pneigh_get_next(seq, v, NULL);
	}
out:
	++(*pos);
	return rc;
}
EXPORT_SYMBOL(neigh_seq_next);

void neigh_seq_stop(struct seq_file *seq, void *v)
{
	struct neigh_seq_state *state = seq->private;
	struct neigh_table *tbl = state->tbl;

	read_unlock_bh(&tbl->lock);
}
EXPORT_SYMBOL(neigh_seq_stop);

/* statistics via seq_file */

static void *neigh_stat_seq_start(struct seq_file *seq, loff_t *pos)
{
	struct proc_dir_entry *pde = seq->private;
	struct neigh_table *tbl = pde->data;
	int cpu;

	if (*pos == 0)
		return SEQ_START_TOKEN;

	for (cpu = *pos-1; cpu < NR_CPUS; ++cpu) {
		if (!cpu_possible(cpu))
			continue;
		*pos = cpu+1;
		return per_cpu_ptr(tbl->stats, cpu);
	}
	return NULL;
}

static void *neigh_stat_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
	struct proc_dir_entry *pde = seq->private;
	struct neigh_table *tbl = pde->data;
	int cpu;

	for (cpu = *pos; cpu < NR_CPUS; ++cpu) {
		if (!cpu_possible(cpu))
			continue;
		*pos = cpu+1;
		return per_cpu_ptr(tbl->stats, cpu);
	}
	return NULL;
}

static void neigh_stat_seq_stop(struct seq_file *seq, void *v)
{

}

static int neigh_stat_seq_show(struct seq_file *seq, void *v)
{
	struct proc_dir_entry *pde = seq->private;
	struct neigh_table *tbl = pde->data;
	struct neigh_statistics *st = v;

	if (v == SEQ_START_TOKEN) {
		seq_printf(seq, "entries  allocs destroys hash_grows  lookups hits  res_failed  rcv_probes_mcast rcv_probes_ucast  periodic_gc_runs forced_gc_runs\n");
		return 0;
	}

	seq_printf(seq, "%08x  %08lx %08lx %08lx  %08lx %08lx  %08lx  "
			"%08lx %08lx  %08lx %08lx\n",
		   atomic_read(&tbl->entries),

		   st->allocs,
		   st->destroys,
		   st->hash_grows,

		   st->lookups,
		   st->hits,

		   st->res_failed,

		   st->rcv_probes_mcast,
		   st->rcv_probes_ucast,

		   st->periodic_gc_runs,
		   st->forced_gc_runs
		   );

	return 0;
}

static const struct seq_operations neigh_stat_seq_ops = {
	.start	= neigh_stat_seq_start,
	.next	= neigh_stat_seq_next,
	.stop	= neigh_stat_seq_stop,
	.show	= neigh_stat_seq_show,
};

static int neigh_stat_seq_open(struct inode *inode, struct file *file)
{
	int ret = seq_open(file, &neigh_stat_seq_ops);

	if (!ret) {
		struct seq_file *sf = file->private_data;
		sf->private = PDE(inode);
	}
	return ret;
};

static const struct file_operations neigh_stat_seq_fops = {
	.owner	 = THIS_MODULE,
	.open 	 = neigh_stat_seq_open,
	.read	 = seq_read,
	.llseek	 = seq_lseek,
	.release = seq_release,
};

#endif /* CONFIG_PROC_FS */

static inline size_t neigh_nlmsg_size(void)
{
	return NLMSG_ALIGN(sizeof(struct ndmsg))
	       + nla_total_size(MAX_ADDR_LEN) /* NDA_DST */
	       + nla_total_size(MAX_ADDR_LEN) /* NDA_LLADDR */
	       + nla_total_size(sizeof(struct nda_cacheinfo))
	       + nla_total_size(4); /* NDA_PROBES */
}

static void __neigh_notify(struct neighbour *n, int type, int flags)
{
	struct sk_buff *skb;
	int err = -ENOBUFS;

	skb = nlmsg_new(neigh_nlmsg_size(), GFP_ATOMIC);
	if (skb == NULL)
		goto errout;

	err = neigh_fill_info(skb, n, 0, 0, type, flags);
	if (err < 0) {
		/* -EMSGSIZE implies BUG in neigh_nlmsg_size() */
		WARN_ON(err == -EMSGSIZE);
		kfree_skb(skb);
		goto errout;
	}
	err = rtnl_notify(skb, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
errout:
	if (err < 0)
		rtnl_set_sk_err(RTNLGRP_NEIGH, err);
}

#ifdef CONFIG_ARPD
void neigh_app_ns(struct neighbour *n)
{
	__neigh_notify(n, RTM_GETNEIGH, NLM_F_REQUEST);
}
#endif /* CONFIG_ARPD */

#ifdef CONFIG_SYSCTL

static struct neigh_sysctl_table {
	struct ctl_table_header *sysctl_header;
	ctl_table		neigh_vars[__NET_NEIGH_MAX];
	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 __read_mostly = {
	.neigh_vars = {
		{
			.ctl_name	= NET_NEIGH_MCAST_SOLICIT,
			.procname	= "mcast_solicit",
			.maxlen		= sizeof(int),
			.mode		= 0644,
			.proc_handler	= &proc_dointvec,
		},
		{
			.ctl_name	= NET_NEIGH_UCAST_SOLICIT,
			.procname	= "ucast_solicit",
			.maxlen		= sizeof(int),
			.mode		= 0644,
			.proc_handler	= &proc_dointvec,
		},
		{
			.ctl_name	= NET_NEIGH_APP_SOLICIT,
			.procname	= "app_solicit",
			.maxlen		= sizeof(int),
			.mode		= 0644,
			.proc_handler	= &proc_dointvec,
		},
		{
			.procname	= "retrans_time",
			.maxlen		= sizeof(int),
			.mode		= 0644,
			.proc_handler	= &proc_dointvec_userhz_jiffies,
		},
		{
			.ctl_name	= NET_NEIGH_REACHABLE_TIME,
			.procname	= "base_reachable_time",
			.maxlen		= sizeof(int),
			.mode		= 0644,
			.proc_handler	= &proc_dointvec_jiffies,
			.strategy	= &sysctl_jiffies,
		},
		{
			.ctl_name	= NET_NEIGH_DELAY_PROBE_TIME,
			.procname	= "delay_first_probe_time",
			.maxlen		= sizeof(int),
			.mode		= 0644,
			.proc_handler	= &proc_dointvec_jiffies,
			.strategy	= &sysctl_jiffies,
		},
		{
			.ctl_name	= NET_NEIGH_GC_STALE_TIME,
			.procname	= "gc_stale_time",
			.maxlen		= sizeof(int),
			.mode		= 0644,
			.proc_handler	= &proc_dointvec_jiffies,
			.strategy	= &sysctl_jiffies,
		},
		{
			.ctl_name	= NET_NEIGH_UNRES_QLEN,
			.procname	= "unres_qlen",
			.maxlen		= sizeof(int),
			.mode		= 0644,
			.proc_handler	= &proc_dointvec,
		},
		{
			.ctl_name	= NET_NEIGH_PROXY_QLEN,
			.procname	= "proxy_qlen",
			.maxlen		= sizeof(int),
			.mode		= 0644,
			.proc_handler	= &proc_dointvec,
		},
		{
			.procname	= "anycast_delay",
			.maxlen		= sizeof(int),
			.mode		= 0644,
			.proc_handler	= &proc_dointvec_userhz_jiffies,
		},
		{
			.procname	= "proxy_delay",
			.maxlen		= sizeof(int),
			.mode		= 0644,
			.proc_handler	= &proc_dointvec_userhz_jiffies,
		},
		{
			.procname	= "locktime",
			.maxlen		= sizeof(int),
			.mode		= 0644,
			.proc_handler	= &proc_dointvec_userhz_jiffies,
		},
		{
			.ctl_name	= NET_NEIGH_RETRANS_TIME_MS,
			.procname	= "retrans_time_ms",
			.maxlen		= sizeof(int),
			.mode		= 0644,
			.proc_handler	= &proc_dointvec_ms_jiffies,
			.strategy	= &sysctl_ms_jiffies,
		},
		{
			.ctl_name	= NET_NEIGH_REACHABLE_TIME_MS,
			.procname	= "base_reachable_time_ms",
			.maxlen		= sizeof(int),
			.mode		= 0644,
			.proc_handler	= &proc_dointvec_ms_jiffies,
			.strategy	= &sysctl_ms_jiffies,
		},
		{
			.ctl_name	= NET_NEIGH_GC_INTERVAL,
			.procname	= "gc_interval",
			.maxlen		= sizeof(int),
			.mode		= 0644,
			.proc_handler	= &proc_dointvec_jiffies,
			.strategy	= &sysctl_jiffies,
		},
		{
			.ctl_name	= NET_NEIGH_GC_THRESH1,
			.procname	= "gc_thresh1",
			.maxlen		= sizeof(int),
			.mode		= 0644,
			.proc_handler	= &proc_dointvec,
		},
		{
			.ctl_name	= NET_NEIGH_GC_THRESH2,
			.procname	= "gc_thresh2",
			.maxlen		= sizeof(int),
			.mode		= 0644,
			.proc_handler	= &proc_dointvec,
		},
		{
			.ctl_name	= NET_NEIGH_GC_THRESH3,
			.procname	= "gc_thresh3",
			.maxlen		= sizeof(int),
			.mode		= 0644,
			.proc_handler	= &proc_dointvec,
		},
		{}
	},
	.neigh_dev = {
		{
			.ctl_name	= NET_PROTO_CONF_DEFAULT,
			.procname	= "default",
			.mode		= 0555,
		},
	},
	.neigh_neigh_dir = {
		{
			.procname	= "neigh",
			.mode		= 0555,
		},
	},
	.neigh_proto_dir = {
		{
			.mode		= 0555,
		},
	},
	.neigh_root_dir = {
		{
			.ctl_name	= CTL_NET,
			.procname	= "net",
			.mode		= 0555,
		},
	},
};

int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p,
			  int p_id, int pdev_id, char *p_name,
			  proc_handler *handler, ctl_handler *strategy)
{
	struct neigh_sysctl_table *t = kmemdup(&neigh_sysctl_template,
					       sizeof(*t), GFP_KERNEL);
	const char *dev_name_source = NULL;
	char *dev_name = NULL;
	int err = 0;

	if (!t)
		return -ENOBUFS;
	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;
	t->neigh_vars[12].data  = &p->retrans_time;
	t->neigh_vars[13].data  = &p->base_reachable_time;

	if (dev) {
		dev_name_source = dev->name;
		t->neigh_dev[0].ctl_name = dev->ifindex;
		/* Terminate the table early */
		memset(&t->neigh_vars[14], 0, sizeof(t->neigh_vars[14]));
	} else {
		dev_name_source = t->neigh_dev[0].procname;
		t->neigh_vars[14].data = (int *)(p + 1);
		t->neigh_vars[15].data = (int *)(p + 1) + 1;
		t->neigh_vars[16].data = (int *)(p + 1) + 2;
		t->neigh_vars[17].data = (int *)(p + 1) + 3;
	}


	if (handler || strategy) {
		/* RetransTime */
		t->neigh_vars[3].proc_handler = handler;
		t->neigh_vars[3].strategy = strategy;
		t->neigh_vars[3].extra1 = dev;
		if (!strategy)
			t->neigh_vars[3].ctl_name = CTL_UNNUMBERED;
		/* ReachableTime */
		t->neigh_vars[4].proc_handler = handler;
		t->neigh_vars[4].strategy = strategy;
		t->neigh_vars[4].extra1 = dev;
		if (!strategy)
			t->neigh_vars[4].ctl_name = CTL_UNNUMBERED;
		/* RetransTime (in milliseconds)*/
		t->neigh_vars[12].proc_handler = handler;
		t->neigh_vars[12].strategy = strategy;
		t->neigh_vars[12].extra1 = dev;
		if (!strategy)
			t->neigh_vars[12].ctl_name = CTL_UNNUMBERED;
		/* ReachableTime (in milliseconds) */
		t->neigh_vars[13].proc_handler = handler;
		t->neigh_vars[13].strategy = strategy;
		t->neigh_vars[13].extra1 = dev;
		if (!strategy)
			t->neigh_vars[13].ctl_name = CTL_UNNUMBERED;
	}

	dev_name = kstrdup(dev_name_source, GFP_KERNEL);
	if (!dev_name) {
		err = -ENOBUFS;
		goto free;
	}

	t->neigh_dev[0].procname = dev_name;

	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);
	if (!t->sysctl_header) {
		err = -ENOBUFS;
		goto free_procname;
	}
	p->sysctl_table = t;
	return 0;

	/* error path */
 free_procname:
	kfree(dev_name);
 free:
	kfree(t);

	return err;
}

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->neigh_dev[0].procname);
		kfree(t);
	}
}

#endif	/* CONFIG_SYSCTL */

static int __init neigh_init(void)
{
	rtnl_register(PF_U