linux-imx

/*

 * Linux ARCnet driver - "cap mode" packet encapsulation.

 * It adds sequence numbers to packets for communicating between a user space

 * application and the driver. After a transmit it sends a packet with protocol

 * byte 0 back up to the userspace containing the sequence number of the packet

 * plus the transmit-status on the ArcNet.

 *

 * Written 2002-4 by Esben Nielsen, Vestas Wind Systems A/S

 * Derived from arc-rawmode.c by Avery Pennarun.

 * arc-rawmode was in turned based on skeleton.c, see below.

 *

 * **********************

 *

 * The original copyright of skeleton.c was as follows:

 *

 * skeleton.c Written 1993 by Donald Becker.

 * Copyright 1993 United States Government as represented by the

 * Director, National Security Agency.  This software may only be used

 * and distributed according to the terms of the GNU General Public License as

 * modified by SRC, incorporated herein by reference.

 *

 * **********************

 *

 * For more details, see drivers/net/arcnet.c

 *

 * **********************

 */

​

#define pr_fmt(fmt) "arcnet:" KBUILD_MODNAME ": " fmt

​

#include <linux/module.h>

#include <linux/gfp.h>

#include <linux/init.h>

#include <linux/if_arp.h>

#include <net/arp.h>

#include <linux/netdevice.h>

#include <linux/skbuff.h>

​

#include "arcdevice.h"

​

/* packet receiver */

static void rx(struct net_device *dev, int bufnum,

           struct archdr *pkthdr, int length)

{

    struct arcnet_local *lp = netdev_priv(dev);

    struct sk_buff *skb;

    struct archdr *pkt = pkthdr;

    char *pktbuf, *pkthdrbuf;

    int ofs;

​

    arc_printk(D_DURING, dev, "it's a raw(cap) packet (length=%d)\n",

           length);

​

    if (length >= MinTU)

        ofs = 512 - length;

    else

        ofs = 256 - length;

​

    skb = alloc_skb(length + ARC_HDR_SIZE + sizeof(int), GFP_ATOMIC);

    if (!skb) {

        dev->stats.rx_dropped++;

        return;

    }

    skb_put(skb, length + ARC_HDR_SIZE + sizeof(int));

    skb->dev = dev;

    skb_reset_mac_header(skb);

    pkt = (struct archdr *)skb_mac_header(skb);

    skb_pull(skb, ARC_HDR_SIZE);

​

    /* up to sizeof(pkt->soft) has already been copied from the card

     * squeeze in an int for the cap encapsulation

     * use these variables to be sure we count in bytes, not in

     * sizeof(struct archdr)

     */

    pktbuf = (char *)pkt;

    pkthdrbuf = (char *)pkthdr;

    memcpy(pktbuf, pkthdrbuf, ARC_HDR_SIZE + sizeof(pkt->soft.cap.proto));

    memcpy(pktbuf + ARC_HDR_SIZE + sizeof(pkt->soft.cap.proto) + sizeof(int),

           pkthdrbuf + ARC_HDR_SIZE + sizeof(pkt->soft.cap.proto),

           sizeof(struct archdr) - ARC_HDR_SIZE - sizeof(pkt->soft.cap.proto));

​

    if (length > sizeof(pkt->soft))

        lp->hw.copy_from_card(dev, bufnum, ofs + sizeof(pkt->soft),

                      pkt->soft.raw + sizeof(pkt->soft)

                      + sizeof(int),

                      length - sizeof(pkt->soft));

​

    if (BUGLVL(D_SKB))

        arcnet_dump_skb(dev, skb, "rx");

​

    skb->protocol = cpu_to_be16(ETH_P_ARCNET);

    netif_rx(skb);