wanmain.c

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/*****************************************************************************
* wanmain.c WAN Multiprotocol Router Module. Main code.
*
*       This module is completely hardware-independent and provides
*       the following common services for the WAN Link Drivers:
*        o WAN device management (registering, unregistering)
*        o Network interface management
*        o Physical connection management (dial-up, incoming calls)
*        o Logical connection management (switched virtual circuits)
*        o Protocol encapsulation/decapsulation
*
* Author:   Gideon Hack
*
* Copyright:    (c) 1995-1999 Sangoma Technologies 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.
* ============================================================================
* Nov 24, 2000  Nenad Corbic    Updated for 2.4.X kernels
* Nov 07, 2000  Nenad Corbic    Fixed the Mulit-Port PPP for kernels 2.2.16 and
*               greater.
* Aug 2,  2000  Nenad Corbic    Block the Multi-Port PPP from running on
*                   kernels 2.2.16 or greater.  The SyncPPP
*                   has changed.
* Jul 13, 2000  Nenad Corbic    Added SyncPPP support
*               Added extra debugging in device_setup().
* Oct 01, 1999  Gideon Hack     Update for s514 PCI card
* Dec 27, 1996  Gene Kozin  Initial version (based on Sangoma's WANPIPE)
* Jan 16, 1997  Gene Kozin  router_devlist made public
* Jan 31, 1997  Alan Cox    Hacked it about a bit for 2.1
* Jun 27, 1997  Alan Cox    realigned with vendor code
* Oct 15, 1997  Farhan Thawar   changed wan_encapsulate to add a pad byte of 0
* Apr 20, 1998  Alan Cox    Fixed 2.1 symbols
* May 17, 1998  K. Baranowski   Fixed SNAP encapsulation in wan_encapsulate
* Dec 15, 1998  Arnaldo Melo    support for firmwares of up to 128000 bytes
*                               check wandev->setup return value
* Dec 22, 1998  Arnaldo Melo    vmalloc/vfree used in device_setup to allocate
*                               kernel memory and copy configuration data to
*                               kernel space (for big firmwares)
* Jun 02, 1999  Gideon Hack Updates for Linux 2.0.X and 2.2.X kernels.
*****************************************************************************/

#include <linux/stddef.h>   /* offsetof(), etc. */
#include <linux/capability.h>
#include <linux/errno.h>    /* return codes */
#include <linux/kernel.h>
#include <linux/module.h>   /* support for loadable modules */
#include <linux/slab.h>     /* kmalloc(), kfree() */
#include <linux/mutex.h>
#include <linux/mm.h>
#include <linux/string.h>   /* inline mem*, str* functions */

#include <asm/byteorder.h>  /* htons(), etc. */
#include <linux/wanrouter.h>    /* WAN router API definitions */

#include <linux/vmalloc.h>  /* vmalloc, vfree */
#include <asm/uaccess.h>        /* copy_to/from_user */
#include <linux/init.h>         /* __initfunc et al. */

#define DEV_TO_SLAVE(dev)   (*((struct net_device **)netdev_priv(dev)))

/*
 *  Function Prototypes
 */

/*
 *  WAN device IOCTL handlers
 */

static DEFINE_MUTEX(wanrouter_mutex);
static int wanrouter_device_setup(struct wan_device *wandev,
                  wandev_conf_t __user *u_conf);
static int wanrouter_device_stat(struct wan_device *wandev,
                 wandev_stat_t __user *u_stat);
static int wanrouter_device_shutdown(struct wan_device *wandev);
static int wanrouter_device_new_if(struct wan_device *wandev,
                   wanif_conf_t __user *u_conf);
static int wanrouter_device_del_if(struct wan_device *wandev,
                   char __user *u_name);

/*
 *  Miscellaneous
 */

static struct wan_device *wanrouter_find_device(char *name);
static int wanrouter_delete_interface(struct wan_device *wandev, char *name);
static void lock_adapter_irq(spinlock_t *lock, unsigned long *smp_flags)
    __acquires(lock);
static void unlock_adapter_irq(spinlock_t *lock, unsigned long *smp_flags)
    __releases(lock);



/*
 *  Global Data
 */

static char wanrouter_fullname[]  = "Sangoma WANPIPE Router";
static char wanrouter_copyright[] = "(c) 1995-2000 Sangoma Technologies Inc.";
static char wanrouter_modname[] = ROUTER_NAME; /* short module name */
struct wan_device* wanrouter_router_devlist; /* list of registered devices */

/*
 *  Organize Unique Identifiers for encapsulation/decapsulation
 */

#if 0
static unsigned char wanrouter_oui_ether[] = { 0x00, 0x00, 0x00 };
static unsigned char wanrouter_oui_802_2[] = { 0x00, 0x80, 0xC2 };
#endif

static int __init wanrouter_init(void)
{
    int err;

    printk(KERN_INFO "%s v%u.%u %s\n",
           wanrouter_fullname, ROUTER_VERSION, ROUTER_RELEASE,
           wanrouter_copyright);

    err = wanrouter_proc_init();
    if (err)
        printk(KERN_INFO "%s: can't create entry in proc filesystem!\n",
               wanrouter_modname);

    return err;
}

static void __exit wanrouter_cleanup (void)
{
    wanrouter_proc_cleanup();
}

/*
 * This is just plain dumb.  We should move the bugger to drivers/net/wan,
 * slap it first in directory and make it module_init().  The only reason
 * for subsys_initcall() here is that net goes after drivers (why, BTW?)
 */
subsys_initcall(wanrouter_init);
module_exit(wanrouter_cleanup);

/*
 *  Kernel APIs
 */

/*
 *  Register WAN device.
 *  o verify device credentials
 *  o create an entry for the device in the /proc/net/router directory
 *  o initialize internally maintained fields of the wan_device structure
 *  o link device data space to a singly-linked list
 *  o if it's the first device, then start kernel 'thread'
 *  o increment module use count
 *
 *  Return:
 *  0   Ok
 *  < 0 error.
 *
 *  Context:    process
 */


int register_wan_device(struct wan_device *wandev)
{
    int err, namelen;

    if ((wandev == NULL) || (wandev->magic != ROUTER_MAGIC) ||
        (wandev->name == NULL))
        return -EINVAL;

    namelen = strlen(wandev->name);
    if (!namelen || (namelen > WAN_DRVNAME_SZ))
        return -EINVAL;

    if (wanrouter_find_device(wandev->name))
        return -EEXIST;

#ifdef WANDEBUG
    printk(KERN_INFO "%s: registering WAN device %s\n",
           wanrouter_modname, wandev->name);
#endif

    /*
     *  Register /proc directory entry
     */
    err = wanrouter_proc_add(wandev);
    if (err) {
        printk(KERN_INFO
            "%s: can't create /proc/net/router/%s entry!\n",
            wanrouter_modname, wandev->name);
        return err;
    }

    /*
     *  Initialize fields of the wan_device structure maintained by the
     *  router and update local data.
     */

    wandev->ndev = 0;
    wandev->dev  = NULL;
    wandev->next = wanrouter_router_devlist;
    wanrouter_router_devlist = wandev;
    return 0;
}

/*
 *  Unregister WAN device.
 *  o shut down device
 *  o unlink device data space from the linked list
 *  o delete device entry in the /proc/net/router directory
 *  o decrement module use count
 *
 *  Return:     0   Ok
 *          <0  error.
 *  Context:    process
 */


int unregister_wan_device(char *name)
{
    struct wan_device *wandev, *prev;

    if (name == NULL)
        return -EINVAL;

    for (wandev = wanrouter_router_devlist, prev = NULL;
        wandev && strcmp(wandev->name, name);
        prev = wandev, wandev = wandev->next)
        ;
    if (wandev == NULL)
        return -ENODEV;

#ifdef WANDEBUG
    printk(KERN_INFO "%s: unregistering WAN device %s\n",
           wanrouter_modname, name);
#endif

    if (wandev->state != WAN_UNCONFIGURED)
        wanrouter_device_shutdown(wandev);

    if (prev)
        prev->next = wandev->next;
    else
        wanrouter_router_devlist = wandev->next;

    wanrouter_proc_delete(wandev);
    return 0;
}

#if 0

/*
 *  Encapsulate packet.
 *
 *  Return: encapsulation header size
 *      < 0 - unsupported Ethertype
 *
 *  Notes:
 *  1. This function may be called on interrupt context.
 */


int wanrouter_encapsulate(struct sk_buff *skb, struct net_device *dev,
              unsigned short type)
{
    int hdr_len = 0;

    switch (type) {
    case ETH_P_IP:      /* IP datagram encapsulation */
        hdr_len += 1;
        skb_push(skb, 1);
        skb->data[0] = NLPID_IP;
        break;

    case ETH_P_IPX:     /* SNAP encapsulation */
    case ETH_P_ARP:
        hdr_len += 7;
        skb_push(skb, 7);
        skb->data[0] = 0;
        skb->data[1] = NLPID_SNAP;
        skb_copy_to_linear_data_offset(skb, 2, wanrouter_oui_ether,
                           sizeof(wanrouter_oui_ether));
        *((unsigned short*)&skb->data[5]) = htons(type);
        break;

    default:        /* Unknown packet type */
        printk(KERN_INFO
            "%s: unsupported Ethertype 0x%04X on interface %s!\n",
            wanrouter_modname, type, dev->name);
        hdr_len = -EINVAL;
    }
    return hdr_len;
}


/*
 *  Decapsulate packet.
 *
 *  Return: Ethertype (in network order)
 *          0   unknown encapsulation
 *
 *  Notes:
 *  1. This function may be called on interrupt context.
 */


__be16 wanrouter_type_trans(struct sk_buff *skb, struct net_device *dev)
{
    int cnt = skb->data[0] ? 0 : 1; /* there may be a pad present */
    __be16 ethertype;

    switch (skb->data[cnt]) {
    case NLPID_IP:      /* IP datagramm */
        ethertype = htons(ETH_P_IP);
        cnt += 1;
        break;

    case NLPID_SNAP:    /* SNAP encapsulation */
        if (memcmp(&skb->data[cnt + 1], wanrouter_oui_ether,
               sizeof(wanrouter_oui_ether))){
            printk(KERN_INFO
                "%s: unsupported SNAP OUI %02X-%02X-%02X "
                "on interface %s!\n", wanrouter_modname,
                skb->data[cnt+1], skb->data[cnt+2],
                skb->data[cnt+3], dev->name);
            return 0;
        }
        ethertype = *((__be16*)&skb->data[cnt+4]);
        cnt += 6;
        break;

    /* add other protocols, e.g. CLNP, ESIS, ISIS, if needed */

    default:
        printk(KERN_INFO
            "%s: unsupported NLPID 0x%02X on interface %s!\n",
            wanrouter_modname, skb->data[cnt], dev->name);
        return 0;
    }
    skb->protocol = ethertype;
    skb->pkt_type = PACKET_HOST;    /*  Physically point to point */
    skb_pull(skb, cnt);
    skb_reset_mac_header(skb);
    return ethertype;
}

#endif  /*  0  */

/*
 *  WAN device IOCTL.
 *  o find WAN device associated with this node
 *  o execute requested action or pass command to the device driver
 */

long wanrouter_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
    struct inode *inode = file->f_path.dentry->d_inode;
    int err = 0;
    struct proc_dir_entry *dent;
    struct wan_device *wandev;
    void __user *data = (void __user *)arg;

    if (!capable(CAP_NET_ADMIN))
        return -EPERM;

    if ((cmd >> 8) != ROUTER_IOCTL)
        return -EINVAL;

    dent = PDE(inode);
    if ((dent == NULL) || (dent->data == NULL))
        return -EINVAL;

    wandev = dent->data;
    if (wandev->magic != ROUTER_MAGIC)
        return -EINVAL;

    mutex_lock(&wanrouter_mutex);
    switch (cmd) {
    case ROUTER_SETUP:
        err = wanrouter_device_setup(wandev, data);
        break;

    case ROUTER_DOWN:
        err = wanrouter_device_shutdown(wandev);
        break;

    case ROUTER_STAT:
        err = wanrouter_device_stat(wandev, data);
        break;

    case ROUTER_IFNEW:
        err = wanrouter_device_new_if(wandev, data);
        break;

    case ROUTER_IFDEL:
        err = wanrouter_device_del_if(wandev, data);
        break;

    case ROUTER_IFSTAT:
        break;

    default:
        if ((cmd >= ROUTER_USER) &&
            (cmd <= ROUTER_USER_MAX) &&
            wandev->ioctl)
            err = wandev->ioctl(wandev, cmd, arg);
        else err = -EINVAL;
    }
    mutex_unlock(&wanrouter_mutex);
    return err;
}

/*
 *  WAN Driver IOCTL Handlers
 */

/*
 *  Setup WAN link device.
 *  o verify user address space
 *  o allocate kernel memory and copy configuration data to kernel space
 *  o if configuration data includes extension, copy it to kernel space too
 *  o call driver's setup() entry point
 */

static int wanrouter_device_setup(struct wan_device *wandev,
                  wandev_conf_t __user *u_conf)
{
    void *data = NULL;
    wandev_conf_t *conf;
    int err = -EINVAL;

    if (wandev->setup == NULL) {    /* Nothing to do ? */
        printk(KERN_INFO "%s: ERROR, No setup script: wandev->setup()\n",
                wandev->name);
        return 0;
    }

    conf = kmalloc(sizeof(wandev_conf_t), GFP_KERNEL);
    if (conf == NULL){
        printk(KERN_INFO "%s: ERROR, Failed to allocate kernel memory !\n",
                wandev->name);
        return -ENOBUFS;
    }

    if (copy_from_user(conf, u_conf, sizeof(wandev_conf_t))) {
        printk(KERN_INFO "%s: Failed to copy user config data to kernel space!\n",
                wandev->name);
        kfree(conf);
        return -EFAULT;
    }

    if (conf->magic != ROUTER_MAGIC) {
        kfree(conf);
        printk(KERN_INFO "%s: ERROR, Invalid MAGIC Number\n",
                wandev->name);
        return -EINVAL;
    }

    if (conf->data_size && conf->data) {
        if (conf->data_size > 128000) {
            printk(KERN_INFO
                "%s: ERROR, Invalid firmware data size %i !\n",
                    wandev->name, conf->data_size);
            kfree(conf);
            return -EINVAL;
        }

        data = vmalloc(conf->data_size);
        if (!data) {
            printk(KERN_INFO
                "%s: ERROR, Failed allocate kernel memory !\n",
                wandev->name);
            kfree(conf);
            return -ENOBUFS;
        }
        if (!copy_from_user(data, conf->data, conf->data_size)) {
            conf->data = data;
            err = wandev->setup(wandev, conf);
        } else {
            printk(KERN_INFO
                 "%s: ERROR, Failed to copy from user data !\n",
                   wandev->name);
            err = -EFAULT;
        }
        vfree(data);
    } else {
        printk(KERN_INFO
            "%s: ERROR, No firmware found ! Firmware size = %i !\n",
                wandev->name, conf->data_size);
    }

    kfree(conf);
    return err;
}

/*
 *  Shutdown WAN device.
 *  o delete all not opened logical channels for this device
 *  o call driver's shutdown() entry point
 */

static int wanrouter_device_shutdown(struct wan_device *wandev)
{
    struct net_device *dev;
    int err=0;

    if (wandev->state == WAN_UNCONFIGURED)
        return 0;

    printk(KERN_INFO "\n%s: Shutting Down!\n",wandev->name);

    for (dev = wandev->dev; dev;) {
        err = wanrouter_delete_interface(wandev, dev->name);
        if (err)
            return err;
        /* The above function deallocates the current dev
         * structure. Therefore, we cannot use netdev_priv(dev)
         * as the next element: wandev->dev points to the
         * next element */
        dev = wandev->dev;
    }

    if (wandev->ndev)
        return -EBUSY;  /* there are opened interfaces  */

    if (wandev->shutdown)
        err=wandev->shutdown(wandev);

    return err;
}

/*
 *  Get WAN device status & statistics.
 */

static int wanrouter_device_stat(struct wan_device *wandev,
                 wandev_stat_t __user *u_stat)
{
    wandev_stat_t stat;

    memset(&stat, 0, sizeof(stat));

    /* Ask device driver to update device statistics */
    if ((wandev->state != WAN_UNCONFIGURED) && wandev->update)
        wandev->update(wandev);

    /* Fill out structure */
    stat.ndev  = wandev->ndev;
    stat.state = wandev->state;

    if (copy_to_user(u_stat, &stat, sizeof(stat)))
        return -EFAULT;

    return 0;
}

/*
 *  Create new WAN interface.
 *  o verify user address space
 *  o copy configuration data to kernel address space
 *  o allocate network interface data space
 *  o call driver's new_if() entry point
 *  o make sure there is no interface name conflict
 *  o register network interface
 */

static int wanrouter_device_new_if(struct wan_device *wandev,
                   wanif_conf_t __user *u_conf)
{
    wanif_conf_t *cnf;
    struct net_device *dev = NULL;
    int err;

    if ((wandev->state == WAN_UNCONFIGURED) || (wandev->new_if == NULL))
        return -ENODEV;

    cnf = kmalloc(sizeof(wanif_conf_t), GFP_KERNEL);
    if (!cnf)
        return -ENOBUFS;

    err = -EFAULT;
    if (copy_from_user(cnf, u_conf, sizeof(wanif_conf_t)))
        goto out;

    err = -EINVAL;
    if (cnf->magic != ROUTER_MAGIC)
        goto out;

    if (cnf->config_id == WANCONFIG_MPPP) {
        printk(KERN_INFO "%s: Wanpipe Mulit-Port PPP support has not been compiled in!\n",
                wandev->name);
        err = -EPROTONOSUPPORT;
        goto out;
    } else {
        err = wandev->new_if(wandev, dev, cnf);
    }

    if (!err) {
        /* Register network interface. This will invoke init()
         * function supplied by the driver.  If device registered
         * successfully, add it to the interface list.
         */

#ifdef WANDEBUG
        printk(KERN_INFO "%s: registering interface %s...\n",
               wanrouter_modname, dev->name);
#endif

        err = register_netdev(dev);
        if (!err) {
            struct net_device *slave = NULL;
            unsigned long smp_flags=0;

            lock_adapter_irq(&wandev->lock, &smp_flags);

            if (wandev->dev == NULL) {
                wandev->dev = dev;
            } else {
                for (slave=wandev->dev;
                     DEV_TO_SLAVE(slave);
                     slave = DEV_TO_SLAVE(slave))
                    DEV_TO_SLAVE(slave) = dev;
            }
            ++wandev->ndev;

            unlock_adapter_irq(&wandev->lock, &smp_flags);
            err = 0;    /* done !!! */
            goto out;
        }
        if (wandev->del_if)
            wandev->del_if(wandev, dev);
        free_netdev(dev);
    }

out:
    kfree(cnf);
    return err;
}


/*
 *  Delete WAN logical channel.
 *   o verify user address space
 *   o copy configuration data to kernel address space
 */

static int wanrouter_device_del_if(struct wan_device *wandev, char __user *u_name)
{
    char name[WAN_IFNAME_SZ + 1];
    int err = 0;

    if (wandev->state == WAN_UNCONFIGURED)
        return -ENODEV;

    memset(name, 0, sizeof(name));

    if (copy_from_user(name, u_name, WAN_IFNAME_SZ))
        return -EFAULT;

    err = wanrouter_delete_interface(wandev, name);
    if (err)
        return err;

    /* If last interface being deleted, shutdown card
     * This helps with administration at leaf nodes
     * (You can tell if the person at the other end of the phone
     * has an interface configured) and avoids DoS vulnerabilities
     * in binary driver files - this fixes a problem with the current
     * Sangoma driver going into strange states when all the network
     * interfaces are deleted and the link irrecoverably disconnected.
     */

    if (!wandev->ndev && wandev->shutdown)
        err = wandev->shutdown(wandev);

    return err;
}

/*
 *  Miscellaneous Functions
 */

/*
 *  Find WAN device by name.
 *  Return pointer to the WAN device data space or NULL if device not found.
 */

static struct wan_device *wanrouter_find_device(char *name)
{
    struct wan_device *wandev;

    for (wandev = wanrouter_router_devlist;
         wandev && strcmp(wandev->name, name);
        wandev = wandev->next);
    return wandev;
}

/*
 *  Delete WAN logical channel identified by its name.
 *  o find logical channel by its name
 *  o call driver's del_if() entry point
 *  o unregister network interface
 *  o unlink channel data space from linked list of channels
 *  o release channel data space
 *
 *  Return: 0       success
 *      -ENODEV     channel not found.
 *      -EBUSY      interface is open
 *
 *  Note: If (force != 0), then device will be destroyed even if interface
 *  associated with it is open. It's caller's responsibility to make
 *  sure that opened interfaces are not removed!
 */

static int wanrouter_delete_interface(struct wan_device *wandev, char *name)
{
    struct net_device *dev = NULL, *prev = NULL;
    unsigned long smp_flags=0;

    lock_adapter_irq(&wandev->lock, &smp_flags);
    dev = wandev->dev;
    prev = NULL;
    while (dev && strcmp(name, dev->name)) {
        struct net_device **slave = netdev_priv(dev);
        prev = dev;
        dev = *slave;
    }
    unlock_adapter_irq(&wandev->lock, &smp_flags);

    if (dev == NULL)
        return -ENODEV; /* interface not found */

    if (netif_running(dev))
        return -EBUSY;  /* interface in use */

    if (wandev->del_if)
        wandev->del_if(wandev, dev);

    lock_adapter_irq(&wandev->lock, &smp_flags);
    if (prev) {
        struct net_device **prev_slave = netdev_priv(prev);
        struct net_device **slave = netdev_priv(dev);

        *prev_slave = *slave;
    } else {
        struct net_device **slave = netdev_priv(dev);
        wandev->dev = *slave;
    }
    --wandev->ndev;
    unlock_adapter_irq(&wandev->lock, &smp_flags);

    printk(KERN_INFO "%s: unregistering '%s'\n", wandev->name, dev->name);

    unregister_netdev(dev);

    free_netdev(dev);

    return 0;
}

static void lock_adapter_irq(spinlock_t *lock, unsigned long *smp_flags)
    __acquires(lock)
{
    spin_lock_irqsave(lock, *smp_flags);
}


static void unlock_adapter_irq(spinlock_t *lock, unsigned long *smp_flags)
    __releases(lock)
{
    spin_unlock_irqrestore(lock, *smp_flags);
}

EXPORT_SYMBOL(register_wan_device);
EXPORT_SYMBOL(unregister_wan_device);

MODULE_LICENSE("GPL");

/*
 *  End
 */