lec.c

linux 内核源代码

static void lec_arp_init(struct lec_priv *priv)
{
	unsigned short i;

	for (i = 0; i < LEC_ARP_TABLE_SIZE; i++) {
		INIT_HLIST_HEAD(&priv->lec_arp_tables[i]);
	}
	INIT_HLIST_HEAD(&priv->lec_arp_empty_ones);
	INIT_HLIST_HEAD(&priv->lec_no_forward);
	INIT_HLIST_HEAD(&priv->mcast_fwds);
	spin_lock_init(&priv->lec_arp_lock);
	INIT_DELAYED_WORK(&priv->lec_arp_work, lec_arp_check_expire);
	schedule_delayed_work(&priv->lec_arp_work, LEC_ARP_REFRESH_INTERVAL);
}

static void lec_arp_clear_vccs(struct lec_arp_table *entry)
{
	if (entry->vcc) {
		struct atm_vcc *vcc = entry->vcc;
		struct lec_vcc_priv *vpriv = LEC_VCC_PRIV(vcc);
		struct net_device *dev = (struct net_device *)vcc->proto_data;

		vcc->pop = vpriv->old_pop;
		if (vpriv->xoff)
			netif_wake_queue(dev);
		kfree(vpriv);
		vcc->user_back = NULL;
		vcc->push = entry->old_push;
		vcc_release_async(vcc, -EPIPE);
		entry->vcc = NULL;
	}
	if (entry->recv_vcc) {
		entry->recv_vcc->push = entry->old_recv_push;
		vcc_release_async(entry->recv_vcc, -EPIPE);
		entry->recv_vcc = NULL;
	}
}

/*
 * Insert entry to lec_arp_table
 * LANE2: Add to the end of the list to satisfy 8.1.13
 */
static inline void
lec_arp_add(struct lec_priv *priv, struct lec_arp_table *entry)
{
	struct hlist_head *tmp;

	tmp = &priv->lec_arp_tables[HASH(entry->mac_addr[ETH_ALEN - 1])];
	hlist_add_head(&entry->next, tmp);

	pr_debug("LEC_ARP: Added entry:%2.2x %2.2x %2.2x %2.2x %2.2x %2.2x\n",
		0xff & entry->mac_addr[0], 0xff & entry->mac_addr[1],
		0xff & entry->mac_addr[2], 0xff & entry->mac_addr[3],
		0xff & entry->mac_addr[4], 0xff & entry->mac_addr[5]);
}

/*
 * Remove entry from lec_arp_table
 */
static int
lec_arp_remove(struct lec_priv *priv, struct lec_arp_table *to_remove)
{
	struct hlist_node *node;
	struct lec_arp_table *entry;
	int i, remove_vcc = 1;

	if (!to_remove) {
		return -1;
	}

	hlist_del(&to_remove->next);
	del_timer(&to_remove->timer);

	/* If this is the only MAC connected to this VCC, also tear down the VCC */
	if (to_remove->status >= ESI_FLUSH_PENDING) {
		/*
		 * ESI_FLUSH_PENDING, ESI_FORWARD_DIRECT
		 */
		for (i = 0; i < LEC_ARP_TABLE_SIZE; i++) {
			hlist_for_each_entry(entry, node, &priv->lec_arp_tables[i], next) {
				if (memcmp(to_remove->atm_addr,
					   entry->atm_addr, ATM_ESA_LEN) == 0) {
					remove_vcc = 0;
					break;
				}
			}
		}
		if (remove_vcc)
			lec_arp_clear_vccs(to_remove);
	}
	skb_queue_purge(&to_remove->tx_wait);	/* FIXME: good place for this? */

	pr_debug("LEC_ARP: Removed entry:%2.2x %2.2x %2.2x %2.2x %2.2x %2.2x\n",
		0xff & to_remove->mac_addr[0], 0xff & to_remove->mac_addr[1],
		0xff & to_remove->mac_addr[2], 0xff & to_remove->mac_addr[3],
		0xff & to_remove->mac_addr[4], 0xff & to_remove->mac_addr[5]);
	return 0;
}

#if DEBUG_ARP_TABLE
static char *get_status_string(unsigned char st)
{
	switch (st) {
	case ESI_UNKNOWN:
		return "ESI_UNKNOWN";
	case ESI_ARP_PENDING:
		return "ESI_ARP_PENDING";
	case ESI_VC_PENDING:
		return "ESI_VC_PENDING";
	case ESI_FLUSH_PENDING:
		return "ESI_FLUSH_PENDING";
	case ESI_FORWARD_DIRECT:
		return "ESI_FORWARD_DIRECT";
	default:
		return "<UNKNOWN>";
	}
}

static void dump_arp_table(struct lec_priv *priv)
{
	struct hlist_node *node;
	struct lec_arp_table *rulla;
	char buf[256];
	int i, j, offset;

	printk("Dump %p:\n", priv);
	for (i = 0; i < LEC_ARP_TABLE_SIZE; i++) {
		hlist_for_each_entry(rulla, node, &priv->lec_arp_tables[i], next) {
			offset = 0;
			offset += sprintf(buf, "%d: %p\n", i, rulla);
			offset += sprintf(buf + offset, "Mac:");
			for (j = 0; j < ETH_ALEN; j++) {
				offset += sprintf(buf + offset,
						  "%2.2x ",
						  rulla->mac_addr[j] & 0xff);
			}
			offset += sprintf(buf + offset, "Atm:");
			for (j = 0; j < ATM_ESA_LEN; j++) {
				offset += sprintf(buf + offset,
						  "%2.2x ",
						  rulla->atm_addr[j] & 0xff);
			}
			offset += sprintf(buf + offset,
					  "Vcc vpi:%d vci:%d, Recv_vcc vpi:%d vci:%d Last_used:%lx, Timestamp:%lx, No_tries:%d ",
					  rulla->vcc ? rulla->vcc->vpi : 0,
					  rulla->vcc ? rulla->vcc->vci : 0,
					  rulla->recv_vcc ? rulla->recv_vcc->
					  vpi : 0,
					  rulla->recv_vcc ? rulla->recv_vcc->
					  vci : 0, rulla->last_used,
					  rulla->timestamp, rulla->no_tries);
			offset +=
			    sprintf(buf + offset,
				    "Flags:%x, Packets_flooded:%x, Status: %s ",
				    rulla->flags, rulla->packets_flooded,
				    get_status_string(rulla->status));
			printk("%s\n", buf);
		}
	}

	if (!hlist_empty(&priv->lec_no_forward))
		printk("No forward\n");
	hlist_for_each_entry(rulla, node, &priv->lec_no_forward, next) {
		offset = 0;
		offset += sprintf(buf + offset, "Mac:");
		for (j = 0; j < ETH_ALEN; j++) {
			offset += sprintf(buf + offset, "%2.2x ",
					  rulla->mac_addr[j] & 0xff);
		}
		offset += sprintf(buf + offset, "Atm:");
		for (j = 0; j < ATM_ESA_LEN; j++) {
			offset += sprintf(buf + offset, "%2.2x ",
					  rulla->atm_addr[j] & 0xff);
		}
		offset += sprintf(buf + offset,
				  "Vcc vpi:%d vci:%d, Recv_vcc vpi:%d vci:%d Last_used:%lx, Timestamp:%lx, No_tries:%d ",
				  rulla->vcc ? rulla->vcc->vpi : 0,
				  rulla->vcc ? rulla->vcc->vci : 0,
				  rulla->recv_vcc ? rulla->recv_vcc->vpi : 0,
				  rulla->recv_vcc ? rulla->recv_vcc->vci : 0,
				  rulla->last_used,
				  rulla->timestamp, rulla->no_tries);
		offset += sprintf(buf + offset,
				  "Flags:%x, Packets_flooded:%x, Status: %s ",
				  rulla->flags, rulla->packets_flooded,
				  get_status_string(rulla->status));
		printk("%s\n", buf);
	}

	if (!hlist_empty(&priv->lec_arp_empty_ones))
		printk("Empty ones\n");
	hlist_for_each_entry(rulla, node, &priv->lec_arp_empty_ones, next) {
		offset = 0;
		offset += sprintf(buf + offset, "Mac:");
		for (j = 0; j < ETH_ALEN; j++) {
			offset += sprintf(buf + offset, "%2.2x ",
					  rulla->mac_addr[j] & 0xff);
		}
		offset += sprintf(buf + offset, "Atm:");
		for (j = 0; j < ATM_ESA_LEN; j++) {
			offset += sprintf(buf + offset, "%2.2x ",
					  rulla->atm_addr[j] & 0xff);
		}
		offset += sprintf(buf + offset,
				  "Vcc vpi:%d vci:%d, Recv_vcc vpi:%d vci:%d Last_used:%lx, Timestamp:%lx, No_tries:%d ",
				  rulla->vcc ? rulla->vcc->vpi : 0,
				  rulla->vcc ? rulla->vcc->vci : 0,
				  rulla->recv_vcc ? rulla->recv_vcc->vpi : 0,
				  rulla->recv_vcc ? rulla->recv_vcc->vci : 0,
				  rulla->last_used,
				  rulla->timestamp, rulla->no_tries);
		offset += sprintf(buf + offset,
				  "Flags:%x, Packets_flooded:%x, Status: %s ",
				  rulla->flags, rulla->packets_flooded,
				  get_status_string(rulla->status));
		printk("%s", buf);
	}

	if (!hlist_empty(&priv->mcast_fwds))
		printk("Multicast Forward VCCs\n");
	hlist_for_each_entry(rulla, node, &priv->mcast_fwds, next) {
		offset = 0;
		offset += sprintf(buf + offset, "Mac:");
		for (j = 0; j < ETH_ALEN; j++) {
			offset += sprintf(buf + offset, "%2.2x ",
					  rulla->mac_addr[j] & 0xff);
		}
		offset += sprintf(buf + offset, "Atm:");
		for (j = 0; j < ATM_ESA_LEN; j++) {
			offset += sprintf(buf + offset, "%2.2x ",
					  rulla->atm_addr[j] & 0xff);
		}
		offset += sprintf(buf + offset,
				  "Vcc vpi:%d vci:%d, Recv_vcc vpi:%d vci:%d Last_used:%lx, Timestamp:%lx, No_tries:%d ",
				  rulla->vcc ? rulla->vcc->vpi : 0,
				  rulla->vcc ? rulla->vcc->vci : 0,
				  rulla->recv_vcc ? rulla->recv_vcc->vpi : 0,
				  rulla->recv_vcc ? rulla->recv_vcc->vci : 0,
				  rulla->last_used,
				  rulla->timestamp, rulla->no_tries);
		offset += sprintf(buf + offset,
				  "Flags:%x, Packets_flooded:%x, Status: %s ",
				  rulla->flags, rulla->packets_flooded,
				  get_status_string(rulla->status));
		printk("%s\n", buf);
	}

}
#else
#define dump_arp_table(priv) do { } while (0)
#endif

/*
 * Destruction of arp-cache
 */
static void lec_arp_destroy(struct lec_priv *priv)
{
	unsigned long flags;
	struct hlist_node *node, *next;
	struct lec_arp_table *entry;
	int i;

	cancel_rearming_delayed_work(&priv->lec_arp_work);

	/*
	 * Remove all entries
	 */

	spin_lock_irqsave(&priv->lec_arp_lock, flags);
	for (i = 0; i < LEC_ARP_TABLE_SIZE; i++) {
		hlist_for_each_entry_safe(entry, node, next, &priv->lec_arp_tables[i], next) {
			lec_arp_remove(priv, entry);
			lec_arp_put(entry);
		}
		INIT_HLIST_HEAD(&priv->lec_arp_tables[i]);
	}

	hlist_for_each_entry_safe(entry, node, next, &priv->lec_arp_empty_ones, next) {
		del_timer_sync(&entry->timer);
		lec_arp_clear_vccs(entry);
		hlist_del(&entry->next);
		lec_arp_put(entry);
	}
	INIT_HLIST_HEAD(&priv->lec_arp_empty_ones);

	hlist_for_each_entry_safe(entry, node, next, &priv->lec_no_forward, next) {
		del_timer_sync(&entry->timer);
		lec_arp_clear_vccs(entry);
		hlist_del(&entry->next);
		lec_arp_put(entry);
	}
	INIT_HLIST_HEAD(&priv->lec_no_forward);

	hlist_for_each_entry_safe(entry, node, next, &priv->mcast_fwds, next) {
		/* No timer, LANEv2 7.1.20 and 2.3.5.3 */
		lec_arp_clear_vccs(entry);
		hlist_del(&entry->next);
		lec_arp_put(entry);
	}
	INIT_HLIST_HEAD(&priv->mcast_fwds);
	priv->mcast_vcc = NULL;
	spin_unlock_irqrestore(&priv->lec_arp_lock, flags);
}

/*
 * Find entry by mac_address
 */
static struct lec_arp_table *lec_arp_find(struct lec_priv *priv,
					  unsigned char *mac_addr)
{
	struct hlist_node *node;
	struct hlist_head *head;
	struct lec_arp_table *entry;

	pr_debug("LEC_ARP: lec_arp_find :%2.2x %2.2x %2.2x %2.2x %2.2x %2.2x\n",
		mac_addr[0] & 0xff, mac_addr[1] & 0xff, mac_addr[2] & 0xff,
		mac_addr[3] & 0xff, mac_addr[4] & 0xff, mac_addr[5] & 0xff);

	head = &priv->lec_arp_tables[HASH(mac_addr[ETH_ALEN - 1])];
	hlist_for_each_entry(entry, node, head, next) {
		if (!compare_ether_addr(mac_addr, entry->mac_addr)) {
			return entry;
		}
	}
	return NULL;
}

static struct lec_arp_table *make_entry(struct lec_priv *priv,
					unsigned char *mac_addr)
{
	struct lec_arp_table *to_return;

	to_return = kzalloc(sizeof(struct lec_arp_table), GFP_ATOMIC);
	if (!to_return) {
		printk("LEC: Arp entry kmalloc failed\n");
		return NULL;
	}
	memcpy(to_return->mac_addr, mac_addr, ETH_ALEN);
	INIT_HLIST_NODE(&to_return->next);
	init_timer(&to_return->timer);
	to_return->timer.function = lec_arp_expire_arp;
	to_return->timer.data = (unsigned long)to_return;
	to_return->last_used = jiffies;
	to_return->priv = priv;
	skb_queue_head_init(&to_return->tx_wait);
	atomic_set(&to_return->usage, 1);
	return to_return;
}

/* Arp sent timer expired */
static void lec_arp_expire_arp(unsigned long data)
{
	struct lec_arp_table *entry;

	entry = (struct lec_arp_table *)data;

	pr_debug("lec_arp_expire_arp\n");
	if (entry->status == ESI_ARP_PENDING) {
		if (entry->no_tries <= entry->priv->max_retry_count) {
			if (entry->is_rdesc)
				send_to_lecd(entry->priv, l_rdesc_arp_xmt,
					     entry->mac_addr, NULL, NULL);
			else
				send_to_lecd(entry->priv, l_arp_xmt,
					     entry->mac_addr, NULL, NULL);
			entry->no_tries++;
		}
		mod_timer(&entry->timer, jiffies + (1 * HZ));
	}
}

/* Unknown/unused vcc expire, remove associated entry */
static void lec_arp_expire_vcc(unsigned long data)
{
	unsigned long flags;
	struct lec_arp_table *to_remove = (struct lec_arp_table *)data;
	struct lec_priv *priv = (struct lec_priv *)to_remove->priv;

	del_timer(&to_remove->timer);

	pr_debug("LEC_ARP %p %p: lec_arp_expire_vcc vpi:%d vci:%d\n",
		to_remove, priv,
		to_remove->vcc ? to_remove->recv_vcc->vpi : 0,
		to_remove->vcc ? to_remove->recv_vcc->vci : 0);

	spin_lock_irqsave(&priv->lec_arp_lock, flags);
	hlist_del(&to_remove->next);
	spin_unlock_irqrestore(&priv->lec_arp_lock, flags);

	lec_arp_clear_vccs(to_remove);
	lec_arp_put(to_remove);
}

/*
 * Expire entries.
 * 1. Re-set timer
 * 2. For each entry, delete entries that have aged past the age limit.
 * 3. For each entry, depending on the status of the entry, perform
 *    the following maintenance.
 *    a. If status is ESI_VC_PENDING or ESI_ARP_PENDING then if the
 *       tick_count is above the max_unknown_frame_time, clear
 *       the tick_count to zero and clear the packets_flooded counter
 *       to zero. This supports the packet rate limit per address
 *       while flooding unknowns.
 *    b. If the status is ESI_FLUSH_PENDING and the tick_count is greater
 *       than or equal to the path_switching_delay, change the status
 *       to ESI_FORWARD_DIRECT. This causes the flush period to end
 *       regardless of the progress of the flush protocol.
 */
static void lec_arp_check_expire(struct work_struct *work)
{
	unsigned long flags;
	struct lec_priv *priv =
		container_of(work, struct lec_priv, lec_arp_work.work);
	struct hlist_node *node, *next;
	struct lec_arp_table *entry;
	unsigned long now;
	unsigned long time_to_check;
	int i;

	pr_debug("lec_arp_check_expire %p\n", priv);
	now = jiffies;
restart:
	spin_lock_irqsave(&priv->lec_arp_lock, flags);
	for (i = 0; i < LEC_ARP_TABLE_SIZE; i++) {
		hlist_for_each_entry_safe(entry, node, next, &priv->lec_arp_tables[i], next) {
			if ((entry->flags) & LEC_REMOTE_FLAG &&
			    priv->topology_change)
				time_to_check = priv->forward_delay_time;
			else
				time_to_check = priv->aging_time;

			pr_debug("About to expire: %lx - %lx > %lx\n",
				now, entry->last_used, time_to_check);
			if (time_after(now, entry->last_used + time_to_check)
			    && !(entry->flags & LEC_PERMANENT_FLAG)
			    && !(entry->mac_addr[0] & 0x01)) {	/* LANE2: 7.1.20 */
				/* Remove entry */
				pr_debug("LEC:Entry timed out\n");
				lec_arp_remove(priv, entry);
				lec_arp_put(entry);
			} else {
				/* Something else */
				if ((entry->status == ESI_VC_PENDING ||
				     entry->status == ESI_ARP_PENDING)
				    && time_after_eq(now,
						     entry->timestamp +
						     priv->
						     max_unknown_frame_time)) {
					entry->timestamp = jiffies;
					entry->packets_flooded = 0;
					if (entry->status == ESI_VC_PENDING)
						send_to_lecd(priv, l_svc_setup,
							     entry->mac_addr,
							     entry->atm_addr,
							     NULL);
				}
				if (entry->status == ESI_FLUSH_PENDING
				    &&
				    time_after_eq(now, entry->timestamp +
						  priv->path_switching_delay)) {
					struct sk_buff *skb;
					struct atm_vcc *vcc = entry->vcc;

					lec_arp_hold(entry);
					spin_unlock_irqrestore(&priv->lec_arp_lock, flags);
					while ((skb = skb_dequeue(&entry->tx_wait)) != NULL)
						lec_send(vcc, skb, entry->priv);
					entry->last_used = jiffies;
					entry->status = ESI_FORWARD_DIRECT;
					lec_arp_put(entry);
					goto restart;
				}
			}
		}
	}
	spin_unlock_irqrestore(&priv->lec_arp_lock, flags);

	schedule_delayed_work(&priv->lec_arp_work, LEC_ARP_REFRESH_INTERVAL);
}

/*
 * Try to find vcc where mac_address is attached.
 *