lec.c

linux 内核源代码

/*
 * lec.c: Lan Emulation driver
 *
 * Marko Kiiskila <[e-mail]>
 */

#include <linux/kernel.h>
#include <linux/bitops.h>
#include <linux/capability.h>

/* We are ethernet device */
#include <linux/if_ether.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <net/sock.h>
#include <linux/skbuff.h>
#include <linux/ip.h>
#include <asm/byteorder.h>
#include <asm/uaccess.h>
#include <net/arp.h>
#include <net/dst.h>
#include <linux/proc_fs.h>
#include <linux/spinlock.h>
#include <linux/seq_file.h>

/* TokenRing if needed */
#ifdef CONFIG_TR
#include <linux/trdevice.h>
#endif

/* And atm device */
#include <linux/atmdev.h>
#include <linux/atmlec.h>

/* Proxy LEC knows about bridging */
#if defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)
#include <linux/if_bridge.h>
#include "../bridge/br_private.h"

static unsigned char bridge_ula_lec[] = { 0x01, 0x80, 0xc2, 0x00, 0x00 };
#endif

/* Modular too */
#include <linux/module.h>
#include <linux/init.h>

#include "lec.h"
#include "lec_arpc.h"
#include "resources.h"

#define DUMP_PACKETS 0		/*
				 * 0 = None,
				 * 1 = 30 first bytes
				 * 2 = Whole packet
				 */

#define LEC_UNRES_QUE_LEN 8	/*
				 * number of tx packets to queue for a
				 * single destination while waiting for SVC
				 */

static int lec_open(struct net_device *dev);
static int lec_start_xmit(struct sk_buff *skb, struct net_device *dev);
static int lec_close(struct net_device *dev);
static struct net_device_stats *lec_get_stats(struct net_device *dev);
static void lec_init(struct net_device *dev);
static struct lec_arp_table *lec_arp_find(struct lec_priv *priv,
					  unsigned char *mac_addr);
static int lec_arp_remove(struct lec_priv *priv,
			  struct lec_arp_table *to_remove);
/* LANE2 functions */
static void lane2_associate_ind(struct net_device *dev, u8 *mac_address,
				u8 *tlvs, u32 sizeoftlvs);
static int lane2_resolve(struct net_device *dev, u8 *dst_mac, int force,
			 u8 **tlvs, u32 *sizeoftlvs);
static int lane2_associate_req(struct net_device *dev, u8 *lan_dst,
			       u8 *tlvs, u32 sizeoftlvs);

static int lec_addr_delete(struct lec_priv *priv, unsigned char *atm_addr,
			   unsigned long permanent);
static void lec_arp_check_empties(struct lec_priv *priv,
				  struct atm_vcc *vcc, struct sk_buff *skb);
static void lec_arp_destroy(struct lec_priv *priv);
static void lec_arp_init(struct lec_priv *priv);
static struct atm_vcc *lec_arp_resolve(struct lec_priv *priv,
				       unsigned char *mac_to_find,
				       int is_rdesc,
				       struct lec_arp_table **ret_entry);
static void lec_arp_update(struct lec_priv *priv, unsigned char *mac_addr,
			   unsigned char *atm_addr, unsigned long remoteflag,
			   unsigned int targetless_le_arp);
static void lec_flush_complete(struct lec_priv *priv, unsigned long tran_id);
static int lec_mcast_make(struct lec_priv *priv, struct atm_vcc *vcc);
static void lec_set_flush_tran_id(struct lec_priv *priv,
				  unsigned char *atm_addr,
				  unsigned long tran_id);
static void lec_vcc_added(struct lec_priv *priv, struct atmlec_ioc *ioc_data,
			  struct atm_vcc *vcc,
			  void (*old_push) (struct atm_vcc *vcc,
					    struct sk_buff *skb));
static void lec_vcc_close(struct lec_priv *priv, struct atm_vcc *vcc);

/* must be done under lec_arp_lock */
static inline void lec_arp_hold(struct lec_arp_table *entry)
{
	atomic_inc(&entry->usage);
}

static inline void lec_arp_put(struct lec_arp_table *entry)
{
	if (atomic_dec_and_test(&entry->usage))
		kfree(entry);
}


static struct lane2_ops lane2_ops = {
	lane2_resolve,		/* resolve,             spec 3.1.3 */
	lane2_associate_req,	/* associate_req,       spec 3.1.4 */
	NULL			/* associate indicator, spec 3.1.5 */
};

static unsigned char bus_mac[ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };

/* Device structures */
static struct net_device *dev_lec[MAX_LEC_ITF];

#if defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)
static void lec_handle_bridge(struct sk_buff *skb, struct net_device *dev)
{
	struct ethhdr *eth;
	char *buff;
	struct lec_priv *priv;

	/*
	 * Check if this is a BPDU. If so, ask zeppelin to send
	 * LE_TOPOLOGY_REQUEST with the same value of Topology Change bit
	 * as the Config BPDU has
	 */
	eth = (struct ethhdr *)skb->data;
	buff = skb->data + skb->dev->hard_header_len;
	if (*buff++ == 0x42 && *buff++ == 0x42 && *buff++ == 0x03) {
		struct sock *sk;
		struct sk_buff *skb2;
		struct atmlec_msg *mesg;

		skb2 = alloc_skb(sizeof(struct atmlec_msg), GFP_ATOMIC);
		if (skb2 == NULL)
			return;
		skb2->len = sizeof(struct atmlec_msg);
		mesg = (struct atmlec_msg *)skb2->data;
		mesg->type = l_topology_change;
		buff += 4;
		mesg->content.normal.flag = *buff & 0x01;	/* 0x01 is topology change */

		priv = (struct lec_priv *)dev->priv;
		atm_force_charge(priv->lecd, skb2->truesize);
		sk = sk_atm(priv->lecd);
		skb_queue_tail(&sk->sk_receive_queue, skb2);
		sk->sk_data_ready(sk, skb2->len);
	}

	return;
}
#endif /* defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE) */

/*
 * Modelled after tr_type_trans
 * All multicast and ARE or STE frames go to BUS.
 * Non source routed frames go by destination address.
 * Last hop source routed frames go by destination address.
 * Not last hop source routed frames go by _next_ route descriptor.
 * Returns pointer to destination MAC address or fills in rdesc
 * and returns NULL.
 */
#ifdef CONFIG_TR
static unsigned char *get_tr_dst(unsigned char *packet, unsigned char *rdesc)
{
	struct trh_hdr *trh;
	int riflen, num_rdsc;

	trh = (struct trh_hdr *)packet;
	if (trh->daddr[0] & (uint8_t) 0x80)
		return bus_mac;	/* multicast */

	if (trh->saddr[0] & TR_RII) {
		riflen = (ntohs(trh->rcf) & TR_RCF_LEN_MASK) >> 8;
		if ((ntohs(trh->rcf) >> 13) != 0)
			return bus_mac;	/* ARE or STE */
	} else
		return trh->daddr;	/* not source routed */

	if (riflen < 6)
		return trh->daddr;	/* last hop, source routed */

	/* riflen is 6 or more, packet has more than one route descriptor */
	num_rdsc = (riflen / 2) - 1;
	memset(rdesc, 0, ETH_ALEN);
	/* offset 4 comes from LAN destination field in LE control frames */
	if (trh->rcf & htons((uint16_t) TR_RCF_DIR_BIT))
		memcpy(&rdesc[4], &trh->rseg[num_rdsc - 2], sizeof(__be16));
	else {
		memcpy(&rdesc[4], &trh->rseg[1], sizeof(__be16));
		rdesc[5] = ((ntohs(trh->rseg[0]) & 0x000f) | (rdesc[5] & 0xf0));
	}

	return NULL;
}
#endif /* CONFIG_TR */

/*
 * Open/initialize the netdevice. This is called (in the current kernel)
 * sometime after booting when the 'ifconfig' program is run.
 *
 * This routine should set everything up anew at each open, even
 * registers that "should" only need to be set once at boot, so that
 * there is non-reboot way to recover if something goes wrong.
 */

static int lec_open(struct net_device *dev)
{
	struct lec_priv *priv = (struct lec_priv *)dev->priv;

	netif_start_queue(dev);
	memset(&priv->stats, 0, sizeof(struct net_device_stats));

	return 0;
}

static __inline__ void
lec_send(struct atm_vcc *vcc, struct sk_buff *skb, struct lec_priv *priv)
{
	ATM_SKB(skb)->vcc = vcc;
	ATM_SKB(skb)->atm_options = vcc->atm_options;

	atomic_add(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
	if (vcc->send(vcc, skb) < 0) {
		priv->stats.tx_dropped++;
		return;
	}

	priv->stats.tx_packets++;
	priv->stats.tx_bytes += skb->len;
}

static void lec_tx_timeout(struct net_device *dev)
{
	printk(KERN_INFO "%s: tx timeout\n", dev->name);
	dev->trans_start = jiffies;
	netif_wake_queue(dev);
}

static int lec_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct sk_buff *skb2;
	struct lec_priv *priv = (struct lec_priv *)dev->priv;
	struct lecdatahdr_8023 *lec_h;
	struct atm_vcc *vcc;
	struct lec_arp_table *entry;
	unsigned char *dst;
	int min_frame_size;
#ifdef CONFIG_TR
	unsigned char rdesc[ETH_ALEN];	/* Token Ring route descriptor */
#endif
	int is_rdesc;
#if DUMP_PACKETS > 0
	char buf[300];
	int i = 0;
#endif /* DUMP_PACKETS >0 */
	DECLARE_MAC_BUF(mac);

	pr_debug("lec_start_xmit called\n");
	if (!priv->lecd) {
		printk("%s:No lecd attached\n", dev->name);
		priv->stats.tx_errors++;
		netif_stop_queue(dev);
		return -EUNATCH;
	}

	pr_debug("skbuff head:%lx data:%lx tail:%lx end:%lx\n",
		(long)skb->head, (long)skb->data, (long)skb_tail_pointer(skb),
		(long)skb_end_pointer(skb));
#if defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)
	if (memcmp(skb->data, bridge_ula_lec, sizeof(bridge_ula_lec)) == 0)
		lec_handle_bridge(skb, dev);
#endif

	/* Make sure we have room for lec_id */
	if (skb_headroom(skb) < 2) {

		pr_debug("lec_start_xmit: reallocating skb\n");
		skb2 = skb_realloc_headroom(skb, LEC_HEADER_LEN);
		kfree_skb(skb);
		if (skb2 == NULL)
			return 0;
		skb = skb2;
	}
	skb_push(skb, 2);

	/* Put le header to place, works for TokenRing too */
	lec_h = (struct lecdatahdr_8023 *)skb->data;
	lec_h->le_header = htons(priv->lecid);

#ifdef CONFIG_TR
	/*
	 * Ugly. Use this to realign Token Ring packets for
	 * e.g. PCA-200E driver.
	 */
	if (priv->is_trdev) {
		skb2 = skb_realloc_headroom(skb, LEC_HEADER_LEN);
		kfree_skb(skb);
		if (skb2 == NULL)
			return 0;
		skb = skb2;
	}
#endif

#if DUMP_PACKETS > 0
	printk("%s: send datalen:%ld lecid:%4.4x\n", dev->name,
	       skb->len, priv->lecid);
#if DUMP_PACKETS >= 2
	for (i = 0; i < skb->len && i < 99; i++) {
		sprintf(buf + i * 3, "%2.2x ", 0xff & skb->data[i]);
	}
#elif DUMP_PACKETS >= 1
	for (i = 0; i < skb->len && i < 30; i++) {
		sprintf(buf + i * 3, "%2.2x ", 0xff & skb->data[i]);
	}
#endif /* DUMP_PACKETS >= 1 */
	if (i == skb->len)
		printk("%s\n", buf);
	else
		printk("%s...\n", buf);
#endif /* DUMP_PACKETS > 0 */

	/* Minimum ethernet-frame size */
#ifdef CONFIG_TR
	if (priv->is_trdev)
		min_frame_size = LEC_MINIMUM_8025_SIZE;
	else
#endif
		min_frame_size = LEC_MINIMUM_8023_SIZE;
	if (skb->len < min_frame_size) {
		if ((skb->len + skb_tailroom(skb)) < min_frame_size) {
			skb2 = skb_copy_expand(skb, 0,
					       min_frame_size - skb->truesize,
					       GFP_ATOMIC);
			dev_kfree_skb(skb);
			if (skb2 == NULL) {
				priv->stats.tx_dropped++;
				return 0;
			}
			skb = skb2;
		}
		skb_put(skb, min_frame_size - skb->len);
	}

	/* Send to right vcc */
	is_rdesc = 0;
	dst = lec_h->h_dest;
#ifdef CONFIG_TR
	if (priv->is_trdev) {
		dst = get_tr_dst(skb->data + 2, rdesc);
		if (dst == NULL) {
			dst = rdesc;
			is_rdesc = 1;
		}
	}
#endif
	entry = NULL;
	vcc = lec_arp_resolve(priv, dst, is_rdesc, &entry);
	pr_debug("%s:vcc:%p vcc_flags:%lx, entry:%p\n", dev->name,
		vcc, vcc ? vcc->flags : 0, entry);
	if (!vcc || !test_bit(ATM_VF_READY, &vcc->flags)) {
		if (entry && (entry->tx_wait.qlen < LEC_UNRES_QUE_LEN)) {
			pr_debug("%s:lec_start_xmit: queuing packet, ",
				dev->name);
			pr_debug("MAC address %s\n",
				 print_mac(mac, lec_h->h_dest));
			skb_queue_tail(&entry->tx_wait, skb);
		} else {
			pr_debug
			    ("%s:lec_start_xmit: tx queue full or no arp entry, dropping, ",
			     dev->name);
			pr_debug("MAC address %s\n",
				 print_mac(mac, lec_h->h_dest));
			priv->stats.tx_dropped++;
			dev_kfree_skb(skb);
		}
		goto out;
	}
#if DUMP_PACKETS > 0
	printk("%s:sending to vpi:%d vci:%d\n", dev->name, vcc->vpi, vcc->vci);
#endif /* DUMP_PACKETS > 0 */

	while (entry && (skb2 = skb_dequeue(&entry->tx_wait))) {
		pr_debug("lec.c: emptying tx queue, ");
		pr_debug("MAC address %s\n",
			 print_mac(mac, lec_h->h_dest));
		lec_send(vcc, skb2, priv);
	}

	lec_send(vcc, skb, priv);

	if (!atm_may_send(vcc, 0)) {
		struct lec_vcc_priv *vpriv = LEC_VCC_PRIV(vcc);

		vpriv->xoff = 1;
		netif_stop_queue(dev);

		/*
		 * vcc->pop() might have occurred in between, making
		 * the vcc usuable again.  Since xmit is serialized,
		 * this is the only situation we have to re-test.
		 */

		if (atm_may_send(vcc, 0))
			netif_wake_queue(dev);
	}

out:
	if (entry)
		lec_arp_put(entry);
	dev->trans_start = jiffies;
	return 0;
}

/* The inverse routine to net_open(). */
static int lec_close(struct net_device *dev)
{
	netif_stop_queue(dev);
	return 0;
}

/*
 * Get the current statistics.
 * This may be called with the card open or closed.
 */
static struct net_device_stats *lec_get_stats(struct net_device *dev)
{
	return &((struct lec_priv *)dev->priv)->stats;
}

static int lec_atm_send(struct atm_vcc *vcc, struct sk_buff *skb)
{
	unsigned long flags;
	struct net_device *dev = (struct net_device *)vcc->proto_data;
	struct lec_priv *priv = (struct lec_priv *)dev->priv;
	struct atmlec_msg *mesg;
	struct lec_arp_table *entry;
	int i;
	char *tmp;		/* FIXME */
	DECLARE_MAC_BUF(mac);

	atomic_sub(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
	mesg = (struct atmlec_msg *)skb->data;
	tmp = skb->data;
	tmp += sizeof(struct atmlec_msg);
	pr_debug("%s: msg from zeppelin:%d\n", dev->name, mesg->type);
	switch (mesg->type) {
	case l_set_mac_addr:
		for (i = 0; i < 6; i++) {
			dev->dev_addr[i] = mesg->content.normal.mac_addr[i];
		}
		break;
	case l_del_mac_addr:
		for (i = 0; i < 6; i++) {
			dev->dev_addr[i] = 0;
		}
		break;
	case l_addr_delete:
		lec_addr_delete(priv, mesg->content.normal.atm_addr,
				mesg->content.normal.flag);
		break;
	case l_topology_change:
		priv->topology_change = mesg->content.normal.flag;
		break;
	case l_flush_complete:
		lec_flush_complete(priv, mesg->content.normal.flag);
		break;
	case l_narp_req:	/* LANE2: see 7.1.35 in the lane2 spec */
		spin_lock_irqsave(&priv->lec_arp_lock, flags);
		entry = lec_arp_find(priv, mesg->content.normal.mac_addr);
		lec_arp_remove(priv, entry);
		spin_unlock_irqrestore(&priv->lec_arp_lock, flags);