lec.c

Linux Kernel 2.6.9 for OMAP1710

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

#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/bitops.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/proc_fs.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};

extern struct net_bridge_fdb_entry *(*br_fdb_get_hook)(struct net_bridge *br,
       unsigned char *addr);
extern void (*br_fdb_put_hook)(struct net_bridge_fdb_entry *ent);
#endif

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

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

#if 0
#define DPRINTK printk
#else
#define DPRINTK(format,args...)
#endif

#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 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];

/* This will be called from proc.c via function pointer */
struct net_device *get_dev_lec(int itf)
{
	struct net_device *dev;

	if (itf >= MAX_LEC_ITF)
		return NULL;
	rtnl_lock();
	dev = dev_lec[itf];
	if (dev)
		dev_hold(dev);
	rtnl_unlock();
	return dev;
}

#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 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);
                skb_queue_tail(&priv->lecd->sk->sk_receive_queue, skb2);
                priv->lecd->sk->sk_data_ready(priv->lecd->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
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(uint16_t));
        else {
                memcpy(&rdesc[4], &trh->rseg[1], sizeof(uint16_t));
                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, &vcc->sk->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 */
        
        DPRINTK("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;
        } 

        DPRINTK("skbuff head:%lx data:%lx tail:%lx end:%lx\n",
                (long)skb->head, (long)skb->data, (long)skb->tail,
                (long)skb->end);
#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) {

                DPRINTK("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);
        DPRINTK("%s:vcc:%p vcc_flags:%x, 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)) {
                        DPRINTK("%s:lec_start_xmit: queuing packet, ", dev->name);
                        DPRINTK("MAC address 0x%02x:%02x:%02x:%02x:%02x:%02x\n",
                                lec_h->h_dest[0], lec_h->h_dest[1], lec_h->h_dest[2],
                                lec_h->h_dest[3], lec_h->h_dest[4], lec_h->h_dest[5]);
                        skb_queue_tail(&entry->tx_wait, skb);
                } else {
                        DPRINTK("%s:lec_start_xmit: tx queue full or no arp entry, dropping, ", dev->name);
                        DPRINTK("MAC address 0x%02x:%02x:%02x:%02x:%02x:%02x\n",
                                lec_h->h_dest[0], lec_h->h_dest[1], lec_h->h_dest[2],
                                lec_h->h_dest[3], lec_h->h_dest[4], lec_h->h_dest[5]);
                        priv->stats.tx_dropped++;
                        dev_kfree_skb(skb);
                }
                return 0;
        }
                
#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))) {
                DPRINTK("lec.c: emptying tx queue, ");
                DPRINTK("MAC address 0x%02x:%02x:%02x:%02x:%02x:%02x\n",
                        lec_h->h_dest[0], lec_h->h_dest[1], lec_h->h_dest[2],
                        lec_h->h_dest[3], lec_h->h_dest[4], lec_h->h_dest[5]);
		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);
	}