network.c

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/*
 *
 * arch/xtensa/platforms/iss/network.c
 *
 * Platform specific initialization.
 *
 * Authors: Chris Zankel <[email protected]>
 * Based on work form the UML team.
 *
 * Copyright 2005 Tensilica Inc.
 *
 * This program is free software; you can redistribute  it and/or modify it
 * under  the terms of  the GNU General  Public License as published by the
 * Free Software Foundation;  either version 2 of the  License, or (at your
 * option) any later version.
 *
 */

#include <linux/list.h>
#include <linux/irq.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/timer.h>
#include <linux/if_ether.h>
#include <linux/inetdevice.h>
#include <linux/init.h>
#include <linux/if_tun.h>
#include <linux/etherdevice.h>
#include <linux/interrupt.h>
#include <linux/ioctl.h>
#include <linux/bootmem.h>
#include <linux/ethtool.h>
#include <linux/rtnetlink.h>
#include <linux/platform_device.h>

#include <platform/simcall.h>

#define DRIVER_NAME "iss-netdev"
#define ETH_MAX_PACKET 1500
#define ETH_HEADER_OTHER 14
#define ISS_NET_TIMER_VALUE (2 * HZ)


static DEFINE_SPINLOCK(opened_lock);
static LIST_HEAD(opened);

static DEFINE_SPINLOCK(devices_lock);
static LIST_HEAD(devices);

/* ------------------------------------------------------------------------- */

/* We currently only support the TUNTAP transport protocol. */

#define TRANSPORT_TUNTAP_NAME "tuntap"
#define TRANSPORT_TUNTAP_MTU ETH_MAX_PACKET

struct tuntap_info {
    char dev_name[IFNAMSIZ];
    int fixed_config;
    unsigned char gw[ETH_ALEN];
    int fd;
};

/* ------------------------------------------------------------------------- */


/* This structure contains out private information for the driver. */

struct iss_net_private {

    struct list_head device_list;
    struct list_head opened_list;

    spinlock_t lock;
    struct net_device *dev;
    struct platform_device pdev;
    struct timer_list tl;
    struct net_device_stats stats;

    struct timer_list timer;
    unsigned int timer_val;

    int index;
    int mtu;

    unsigned char mac[ETH_ALEN];
    int have_mac;

    struct {
        union {
            struct tuntap_info tuntap;
        } info;

        int (*open)(struct iss_net_private *lp);
        void (*close)(struct iss_net_private *lp);
        int (*read)(struct iss_net_private *lp, struct sk_buff **skb);
        int (*write)(struct iss_net_private *lp, struct sk_buff **skb);
        unsigned short (*protocol)(struct sk_buff *skb);
        int (*poll)(struct iss_net_private *lp);
    } tp;

};

/* ================================ HELPERS ================================ */


static char *split_if_spec(char *str, ...)
{
    char **arg, *end;
    va_list ap;

    va_start(ap, str);
    while ((arg = va_arg(ap, char**)) != NULL) {
        if (*str == '\0')
            return NULL;
        end = strchr(str, ',');
        if (end != str)
            *arg = str;
        if (end == NULL)
            return NULL;
        *end ++ = '\0';
        str = end;
    }
    va_end(ap);
    return str;
}


#if 0
/* Adjust SKB. */

struct sk_buff *ether_adjust_skb(struct sk_buff *skb, int extra)
{
    if ((skb != NULL) && (skb_tailroom(skb) < extra)) {
        struct sk_buff *skb2;

        skb2 = skb_copy_expand(skb, 0, extra, GFP_ATOMIC);
        dev_kfree_skb(skb);
        skb = skb2;
    }
    if (skb != NULL)
        skb_put(skb, extra);

    return skb;
}
#endif

/* Return the IP address as a string for a given device. */

static void dev_ip_addr(void *d, char *buf, char *bin_buf)
{
    struct net_device *dev = d;
    struct in_device *ip = dev->ip_ptr;
    struct in_ifaddr *in;
    __be32 addr;

    if ((ip == NULL) || ((in = ip->ifa_list) == NULL)) {
        printk(KERN_WARNING "Device not assigned an IP address!\n");
        return;
    }

    addr = in->ifa_address;
    sprintf(buf, "%d.%d.%d.%d", addr & 0xff, (addr >> 8) & 0xff,
        (addr >> 16) & 0xff, addr >> 24);

    if (bin_buf) {
        bin_buf[0] = addr & 0xff;
        bin_buf[1] = (addr >> 8) & 0xff;
        bin_buf[2] = (addr >> 16) & 0xff;
        bin_buf[3] = addr >> 24;
    }
}

/* Set Ethernet address of the specified device. */

static void inline set_ether_mac(void *d, unsigned char *addr)
{
    struct net_device *dev = d;
    memcpy(dev->dev_addr, addr, ETH_ALEN);
}


/* ======================= TUNTAP TRANSPORT INTERFACE ====================== */

static int tuntap_open(struct iss_net_private *lp)
{
    struct ifreq ifr;
    char *dev_name = lp->tp.info.tuntap.dev_name;
    int err = -EINVAL;
    int fd;

    /* We currently only support a fixed configuration. */

    if (!lp->tp.info.tuntap.fixed_config)
        return -EINVAL;

    if ((fd = simc_open("/dev/net/tun", 02, 0)) < 0) {  /* O_RDWR */
        printk("Failed to open /dev/net/tun, returned %d "
               "(errno = %d)\n", fd, errno);
        return fd;
    }

    memset(&ifr, 0, sizeof ifr);
    ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
    strlcpy(ifr.ifr_name, dev_name, sizeof ifr.ifr_name);

    if ((err = simc_ioctl(fd, TUNSETIFF, (void*) &ifr)) < 0) {
        printk("Failed to set interface, returned %d "
               "(errno = %d)\n", err, errno);
        simc_close(fd);
        return err;
    }

    lp->tp.info.tuntap.fd = fd;
    return err;
}

static void tuntap_close(struct iss_net_private *lp)
{
#if 0
    if (lp->tp.info.tuntap.fixed_config)
        iter_addresses(lp->tp.info.tuntap.dev, close_addr, lp->host.dev_name);
#endif
    simc_close(lp->tp.info.tuntap.fd);
    lp->tp.info.tuntap.fd = -1;
}

static int tuntap_read (struct iss_net_private *lp, struct sk_buff **skb)
{
#if 0
    *skb = ether_adjust_skb(*skb, ETH_HEADER_OTHER);
    if (*skb == NULL)
        return -ENOMEM;
#endif

    return simc_read(lp->tp.info.tuntap.fd,
            (*skb)->data, (*skb)->dev->mtu + ETH_HEADER_OTHER);
}

static int tuntap_write (struct iss_net_private *lp, struct sk_buff **skb)
{
    return simc_write(lp->tp.info.tuntap.fd, (*skb)->data, (*skb)->len);
}

unsigned short tuntap_protocol(struct sk_buff *skb)
{
    return eth_type_trans(skb, skb->dev);
}

static int tuntap_poll(struct iss_net_private *lp)
{
    return simc_poll(lp->tp.info.tuntap.fd);
}

/*
 * Currently only a device name is supported.
 * ethX=tuntap[,[mac address][,[device name]]]
 */

static int tuntap_probe(struct iss_net_private *lp, int index, char *init)
{
    const int len = strlen(TRANSPORT_TUNTAP_NAME);
    char *dev_name = NULL, *mac_str = NULL, *rem = NULL;

    /* Transport should be 'tuntap': ethX=tuntap,mac,dev_name */

    if (strncmp(init, TRANSPORT_TUNTAP_NAME, len))
        return 0;

    if (*(init += strlen(TRANSPORT_TUNTAP_NAME)) == ',') {
        if ((rem=split_if_spec(init+1, &mac_str, &dev_name)) != NULL) {
            printk("Extra garbage on specification : '%s'\n", rem);
            return 0;
        }
    } else if (*init != '\0') {
        printk("Invalid argument: %s. Skipping device!\n", init);
        return 0;
    }

    if (dev_name) {
        strncpy(lp->tp.info.tuntap.dev_name, dev_name,
             sizeof lp->tp.info.tuntap.dev_name);
        lp->tp.info.tuntap.fixed_config = 1;
    } else
        strcpy(lp->tp.info.tuntap.dev_name, TRANSPORT_TUNTAP_NAME);


#if 0
    if (setup_etheraddr(mac_str, lp->mac))
        lp->have_mac = 1;
#endif
    lp->mtu = TRANSPORT_TUNTAP_MTU;

    //lp->info.tuntap.gate_addr = gate_addr;

    lp->tp.info.tuntap.fd = -1;

    lp->tp.open = tuntap_open;
    lp->tp.close = tuntap_close;
    lp->tp.read = tuntap_read;
    lp->tp.write = tuntap_write;
    lp->tp.protocol = tuntap_protocol;
    lp->tp.poll = tuntap_poll;

    printk("TUN/TAP backend - ");
#if 0
    if (lp->host.gate_addr != NULL)
        printk("IP = %s", lp->host.gate_addr);
#endif
    printk("\n");

    return 1;
}

/* ================================ ISS NET ================================ */

static int iss_net_rx(struct net_device *dev)
{
    struct iss_net_private *lp = netdev_priv(dev);
    int pkt_len;
    struct sk_buff *skb;

    /* Check if there is any new data. */

    if (lp->tp.poll(lp) == 0)
        return 0;

    /* Try to allocate memory, if it fails, try again next round. */

    if ((skb = dev_alloc_skb(dev->mtu + 2 + ETH_HEADER_OTHER)) == NULL) {
        lp->stats.rx_dropped++;
        return 0;
    }

    skb_reserve(skb, 2);

    /* Setup skb */

    skb->dev = dev;
    skb_reset_mac_header(skb);
    pkt_len = lp->tp.read(lp, &skb);
    skb_put(skb, pkt_len);

    if (pkt_len > 0) {
        skb_trim(skb, pkt_len);
        skb->protocol = lp->tp.protocol(skb);

        lp->stats.rx_bytes += skb->len;
        lp->stats.rx_packets++;
    //  netif_rx(skb);
        netif_rx_ni(skb);
        return pkt_len;
    }
    kfree_skb(skb);
    return pkt_len;
}

static int iss_net_poll(void)
{
    struct list_head *ele;
    int err, ret = 0;

    spin_lock(&opened_lock);

    list_for_each(ele, &opened) {
        struct iss_net_private *lp;

        lp = list_entry(ele, struct iss_net_private, opened_list);

        if (!netif_running(lp->dev))
            break;

        spin_lock(&lp->lock);

        while ((err = iss_net_rx(lp->dev)) > 0)
            ret++;

        spin_unlock(&lp->lock);

        if (err < 0) {
            printk(KERN_ERR "Device '%s' read returned %d, "
                   "shutting it down\n", lp->dev->name, err);
            dev_close(lp->dev);
        } else {
            // FIXME reactivate_fd(lp->fd, ISS_ETH_IRQ);
        }
    }

    spin_unlock(&opened_lock);
    return ret;
}


static void iss_net_timer(unsigned long priv)
{
    struct iss_net_private* lp = (struct iss_net_private*) priv;

    spin_lock(&lp->lock);

    iss_net_poll();

    mod_timer(&lp->timer, jiffies + lp->timer_val);

    spin_unlock(&lp->lock);
}


static int iss_net_open(struct net_device *dev)
{
    struct iss_net_private *lp = netdev_priv(dev);
    char addr[sizeof "255.255.255.255\0"];
    int err;

    spin_lock(&lp->lock);

    if ((err = lp->tp.open(lp)) < 0)
        goto out;

    if (!lp->have_mac) {
        dev_ip_addr(dev, addr, &lp->mac[2]);
        set_ether_mac(dev, lp->mac);
    }

    netif_start_queue(dev);

    /* clear buffer - it can happen that the host side of the interface
     * is full when we get here. In this case, new data is never queued,
     * SIGIOs never arrive, and the net never works.
     */
    while ((err = iss_net_rx(dev)) > 0)
        ;

    spin_lock(&opened_lock);
    list_add(&lp->opened_list, &opened);
    spin_unlock(&opened_lock);

    init_timer(&lp->timer);
    lp->timer_val = ISS_NET_TIMER_VALUE;
    lp->timer.data = (unsigned long) lp;
    lp->timer.function = iss_net_timer;
    mod_timer(&lp->timer, jiffies + lp->timer_val);

out:
    spin_unlock(&lp->lock);
    return err;
}

static int iss_net_close(struct net_device *dev)
{
    struct iss_net_private *lp = netdev_priv(dev);
printk("iss_net_close!\n");
    netif_stop_queue(dev);
    spin_lock(&lp->lock);

    spin_lock(&opened_lock);
    list_del(&opened);
    spin_unlock(&opened_lock);

    del_timer_sync(&lp->timer);

    lp->tp.close(lp);

    spin_unlock(&lp->lock);
    return 0;
}

static int iss_net_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
    struct iss_net_private *lp = netdev_priv(dev);
    unsigned long flags;
    int len;

    netif_stop_queue(dev);
    spin_lock_irqsave(&lp->lock, flags);

    len = lp->tp.write(lp, &skb);

    if (len == skb->len) {
        lp->stats.tx_packets++;
        lp->stats.tx_bytes += skb->len;
        dev->trans_start = jiffies;
        netif_start_queue(dev);

        /* this is normally done in the interrupt when tx finishes */
        netif_wake_queue(dev);

    } else if (len == 0) {
        netif_start_queue(dev);
        lp->stats.tx_dropped++;

    } else {
        netif_start_queue(dev);
        printk(KERN_ERR "iss_net_start_xmit: failed(%d)\n", len);
    }

    spin_unlock_irqrestore(&lp->lock, flags);

    dev_kfree_skb(skb);
    return NETDEV_TX_OK;
}


static struct net_device_stats *iss_net_get_stats(struct net_device *dev)
{
    struct iss_net_private *lp = netdev_priv(dev);
    return &lp->stats;
}

static void iss_net_set_multicast_list(struct net_device *dev)
{
#if 0
    if (dev->flags & IFF_PROMISC)
        return;
    else if (!netdev_mc_empty(dev))
        dev->flags |= IFF_ALLMULTI;
    else
        dev->flags &= ~IFF_ALLMULTI;
#endif
}

static void iss_net_tx_timeout(struct net_device *dev)
{
#if 0
    dev->trans_start = jiffies;
    netif_wake_queue(dev);
#endif
}

static int iss_net_set_mac(struct net_device *dev, void *addr)
{
#if 0
    struct iss_net_private *lp = netdev_priv(dev);
    struct sockaddr *hwaddr = addr;

    spin_lock(&lp->lock);
    memcpy(dev->dev_addr, hwaddr->sa_data, ETH_ALEN);
    spin_unlock(&lp->lock);
#endif

    return 0;
}

static int iss_net_change_mtu(struct net_device *dev, int new_mtu)
{
#if 0
    struct iss_net_private *lp = netdev_priv(dev);
    int err = 0;

    spin_lock(&lp->lock);

    // FIXME not needed new_mtu = transport_set_mtu(new_mtu, &lp->user);

    if (new_mtu < 0)
        err = new_mtu;
    else
        dev->mtu = new_mtu;

    spin_unlock(&lp->lock);
    return err;
#endif
    return -EINVAL;
}

void iss_net_user_timer_expire(unsigned long _conn)
{
}


static struct platform_driver iss_net_driver = {
    .driver = {
        .name  = DRIVER_NAME,
    },
};

static int driver_registered;

static const struct net_device_ops iss_netdev_ops = {
    .ndo_open       = iss_net_open,
    .ndo_stop       = iss_net_close,
    .ndo_get_stats      = iss_net_get_stats,
    .ndo_start_xmit     = iss_net_start_xmit,
    .ndo_validate_addr  = eth_validate_addr,
    .ndo_change_mtu     = iss_net_change_mtu,
    .ndo_set_mac_address    = iss_net_set_mac,
    //.ndo_do_ioctl     = iss_net_ioctl,
    .ndo_tx_timeout     = iss_net_tx_timeout,
    .ndo_set_rx_mode    = iss_net_set_multicast_list,
};

static int iss_net_configure(int index, char *init)
{
    struct net_device *dev;
    struct iss_net_private *lp;
    int err;

    if ((dev = alloc_etherdev(sizeof *lp)) == NULL) {
        printk(KERN_ERR "eth_configure: failed to allocate device\n");
        return 1;
    }

    /* Initialize private element. */

    lp = netdev_priv(dev);
    *lp = ((struct iss_net_private) {
        .device_list        = LIST_HEAD_INIT(lp->device_list),
        .opened_list        = LIST_HEAD_INIT(lp->opened_list),
        .lock           = __SPIN_LOCK_UNLOCKED(lp.lock),
        .dev            = dev,
        .index          = index,
        //.fd                   = -1,
        .mac            = { 0xfe, 0xfd, 0x0, 0x0, 0x0, 0x0 },
        .have_mac       = 0,
        });

    /*
     * Try all transport protocols.
     * Note: more protocols can be added by adding '&& !X_init(lp, eth)'.
     */

    if (!tuntap_probe(lp, index, init)) {
        printk("Invalid arguments. Skipping device!\n");
        goto errout;
    }

    printk(KERN_INFO "Netdevice %d ", index);
    if (lp->have_mac)
        printk("(%pM) ", lp->mac);
    printk(": ");

    /* sysfs register */

    if (!driver_registered) {
        platform_driver_register(&iss_net_driver);
        driver_registered = 1;
    }

    spin_lock(&devices_lock);
    list_add(&lp->device_list, &devices);
    spin_unlock(&devices_lock);

    lp->pdev.id = index;
    lp->pdev.name = DRIVER_NAME;
    platform_device_register(&lp->pdev);
    SET_NETDEV_DEV(dev,&lp->pdev.dev);

    /*
     * If this name ends up conflicting with an existing registered
     * netdevice, that is OK, register_netdev{,ice}() will notice this
     * and fail.
     */
    snprintf(dev->name, sizeof dev->name, "eth%d", index);

    dev->netdev_ops = &iss_netdev_ops;
    dev->mtu = lp->mtu;
    dev->watchdog_timeo = (HZ >> 1);
    dev->irq = -1;

    rtnl_lock();
    err = register_netdevice(dev);
    rtnl_unlock();

    if (err) {
        printk("Error registering net device!\n");
        /* XXX: should we call ->remove() here? */
        free_netdev(dev);
        return 1;
    }

    init_timer(&lp->tl);
    lp->tl.function = iss_net_user_timer_expire;

#if 0
    if (lp->have_mac)
        set_ether_mac(dev, lp->mac);
#endif
    return 0;

errout:
    // FIXME: unregister; free, etc..
    return -EIO;

}

/* ------------------------------------------------------------------------- */

/* Filled in during early boot */

struct list_head eth_cmd_line = LIST_HEAD_INIT(eth_cmd_line);

struct iss_net_init {
    struct list_head list;
    char *init;     /* init string */
    int index;
};

/*
 * Parse the command line and look for 'ethX=...' fields, and register all
 * those fields. They will be later initialized in iss_net_init.
 */

#define ERR KERN_ERR "iss_net_setup: "

static int iss_net_setup(char *str)
{
    struct iss_net_private *device = NULL;
    struct iss_net_init *new;
    struct list_head *ele;
    char *end;
    int n;

    n = simple_strtoul(str, &end, 0);
    if (end == str) {
        printk(ERR "Failed to parse '%s'\n", str);
        return 1;
    }
    if (n < 0) {
        printk(ERR "Device %d is negative\n", n);
        return 1;
    }
    if (*(str = end) != '=') {
        printk(ERR "Expected '=' after device number\n");
        return 1;
    }

    spin_lock(&devices_lock);

    list_for_each(ele, &devices) {
        device = list_entry(ele, struct iss_net_private, device_list);
        if (device->index == n)
            break;
    }

    spin_unlock(&devices_lock);

    if (device && device->index == n) {
        printk(ERR "Device %d already configured\n", n);
        return 1;
    }

    if ((new = alloc_bootmem(sizeof new)) == NULL) {
        printk("Alloc_bootmem failed\n");
        return 1;
    }

    INIT_LIST_HEAD(&new->list);
    new->index = n;
    new->init = str + 1;

    list_add_tail(&new->list, &eth_cmd_line);
    return 1;
}

#undef ERR

__setup("eth=", iss_net_setup);

/*
 * Initialize all ISS Ethernet devices previously registered in iss_net_setup.
 */

static int iss_net_init(void)
{
    struct list_head *ele, *next;

    /* Walk through all Ethernet devices specified in the command line. */

    list_for_each_safe(ele, next, &eth_cmd_line) {
        struct iss_net_init *eth;
        eth = list_entry(ele, struct iss_net_init, list);
        iss_net_configure(eth->index, eth->init);
    }

    return 1;
}

module_init(iss_net_init);