/*
* DLCI Implementation of Frame Relay protocol for Linux, according to
* RFC 1490. This generic device provides en/decapsulation for an
* underlying hardware driver. Routes & IPs are assigned to these
* interfaces. Requires 'dlcicfg' program to create usable
* interfaces, the initial one, 'dlci' is for IOCTL use only.
*
* Version: @(#)dlci.c 0.35 4 Jan 1997
*
* Author: Mike McLagan <mike.mclagan@linux.org>
*
* Changes:
*
* 0.15 Mike Mclagan Packet freeing, bug in kmalloc call
* DLCI_RET handling
* 0.20 Mike McLagan More conservative on which packets
* are returned for retry and which are
* are dropped. If DLCI_RET_DROP is
* returned from the FRAD, the packet is
* sent back to Linux for re-transmission
* 0.25 Mike McLagan Converted to use SIOC IOCTL calls
* 0.30 Jim Freeman Fixed to allow IPX traffic
* 0.35 Michael Elizabeth Fixed incorrect memcpy_fromfs
*
* 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/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/interrupt.h>
#include <linux/ptrace.h>
#include <linux/ioport.h>
#include <linux/in.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/if_arp.h>
#include <linux/if_frad.h>
#include <linux/bitops.h>
#include <net/sock.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/dma.h>
#include <asm/uaccess.h>
static const char version[] = "DLCI driver v0.35, 4 Jan 1997, mike.mclagan@linux.org";
static LIST_HEAD(dlci_devs);
static void dlci_setup(struct net_device *);
/*
* these encapsulate the RFC 1490 requirements as well as
* deal with packet transmission and reception, working with
* the upper network layers
*/
static int dlci_header(struct sk_buff *skb, struct net_device *dev,
unsigned short type, void *daddr, void *saddr,
unsigned len)
{
struct frhdr hdr;
struct dlci_local *dlp;
unsigned int hlen;
char *dest;
dlp = dev->priv;
hdr.control = FRAD_I_UI;
switch(type)
{
case ETH_P_IP:
hdr.IP_NLPID = FRAD_P_IP;
hlen = sizeof(hdr.control) + sizeof(hdr.IP_NLPID);
break;
/* feel free to add other types, if necessary */
default:
hdr.pad = FRAD_P_PADDING;
hdr.NLPID = FRAD_P_SNAP;
memset(hdr.OUI, 0, sizeof(hdr.OUI));
hdr.PID = htons(type);
hlen = sizeof(hdr);
break;
}
dest = skb_push(skb, hlen);
if (!dest)
return(0);
memcpy(dest, &hdr, hlen);
return(hlen);
}
static void dlci_receive(struct sk_buff *skb, struct net_device *dev)
{
struct dlci_local *dlp;
struct frhdr *hdr;
int process, header;
dlp = dev->priv;
if (!pskb_may_pull(skb, sizeof(*hdr))) {
printk(KERN_NOTICE "%s: invalid data no header\n",
dev->name);
dlp->stats.rx_errors++;
kfree_skb(skb);
return;
}
hdr = (struct frhdr *) skb->data;
process = 0;
header = 0;
skb->dev = dev;
if (hdr->control != FRAD_I_UI)
{
printk(KERN_NOTICE "%s: Invalid header flag 0x%02X.\n", dev->name, hdr->control);
dlp->stats.rx_errors++;
}
else
switch(hdr->IP_NLPID)
{
case FRAD_P_PADDING:
if (hdr->NLPID != FRAD_P_SNAP)
{
printk(KERN_NOTICE "%s: Unsupported NLPID 0x%02X.\n", dev->name, hdr->NLPID);
dlp->stats.rx_errors++;
break;
}
if (hdr->OUI[0] + hdr->OUI[1] + hdr->OUI[2] != 0)
{
printk(KERN_NOTICE "%s: Unsupported organizationally unique identifier 0x%02X-%02X-%02X.\n", dev->name, hdr->OUI[0], hdr->OUI[1], hdr->OUI[2]);
dlp->stats.rx_errors++;
break;
}
/* at this point, it's an EtherType frame */
header = sizeof(struct frhdr);
/* Already in network order ! */
skb->protocol = hdr->PID;
process = 1;
break;
case FRAD_P_IP:
header = sizeof(hdr->control) + sizeof(hdr->IP_NLPID);
skb->protocol = htons(ETH_P_IP);
process = 1;
break;
case FRAD_P_SNAP:
case FRAD_P_Q933:
case FRAD_P_CLNP:
printk(KERN_NOTICE "%s: Unsupported NLPID 0x%02X.\n", dev->name, hdr->pad);
dlp->stats.rx_errors++;
break;
default:
printk(KERN_NOTICE "%s: Invalid pad byte 0x%02X.\n", dev->name, hdr->pad);
dlp->stats.rx_errors++;
break;
}
if (process)
{
/* we've set up the protocol, so discard the header */
skb_reset_mac_header(skb);
skb_pull(skb, header);
dlp->stats.rx_bytes += skb->len;
netif_rx(skb);
dlp->stats.rx_packets++;
dev->last_rx = jiffies;
}
else
dev_kfree_skb(skb);
}
static int dlci_transmit(struct sk_buff *skb, struct net_device *dev)
{
struct dlci_local *dlp;
int ret;
ret = 0;
if (!skb || !dev)
return(0);
dlp = dev->priv;
netif_stop_queue(dev);
ret = dlp->slave->hard_start_xmit(skb, dlp->slave);
switch (ret)
{
case DLCI_RET_OK:
dlp->stats.tx_packets++;
ret = 0;
break;
case DLCI_RET_ERR:
dlp->stats.tx_errors++;
ret = 0;
break;
case DLCI_RET_DROP:
dlp->stats.tx_dropped++;
ret = 1;
break;
}
/* Alan Cox recommends always returning 0, and always freeing the packet */
/* experience suggest a slightly more conservative approach */
if (!ret)
{
dev_kfree_skb(skb);
netif_wake_queue(dev);
}
return(ret);
}
static int dlci_config(struct net_device *dev, struct dlci_conf __user *conf, int get)
{
struct dlci_conf config;
struct dlci_local *dlp;
struct frad_local *flp;
int err;
dlp = dev->priv;
flp = dlp->slave->priv;
if (!get)
{
if(copy_from_user(&config, conf, sizeof(struct dlci_conf)))
return -EFAULT;
if (config.flags & ~DLCI_VALID_FLAGS)
return(-EINVAL);
memcpy(&dlp->config, &config, sizeof(struct dlci_conf));
dlp->configured = 1;
}
err = (*flp->dlci_conf)(dlp->slave, dev, get);
if (err)
return(err);
if (get)
{
if(copy_to_user(conf, &dlp->config, sizeof(struct dlci_conf)))
return -EFAULT;
}
return(0);
}
static int dlci_dev_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
struct dlci_local *dlp;
if (!capable(CAP_NET_ADMIN))
return(-EPERM);
dlp = dev->priv;
switch(cmd)
{
case DLCI_GET_SLAVE:
if (!*(short *)(dev->dev_addr))
return(-EINVAL);
strncpy(ifr->ifr_slave, dlp->slave->name, sizeof(ifr->ifr_slave));
break;
case DLCI_GET_CONF:
case DLCI_SET_CONF:
if (!*(short *)(dev->dev_addr))
return(-EINVAL);
return(dlci_config(dev, ifr->ifr_data, cmd == DLCI_GET_CONF));
break;
default:
return(-EOPNOTSUPP);
}
return(0);
}
static int dlci_change_mtu(struct net_device *dev, int new_mtu)
{
struct dlci_local *dlp;
dlp = dev->priv;
return((*dlp->slave->change_mtu)(dlp->slave, new_mtu));
}
static int dlci_open(struct net_device *dev)
{
struct dlci_local *dlp;
struct frad_local *flp;
int err;
dlp = dev->priv;
if (!*(short *)(dev->dev_addr))
return(-EINVAL);
if (!netif_running(dlp->slave))
return(-ENOTCONN);
flp = dlp->slave->priv;
err = (*flp->activate)(dlp->slave, dev);
if (err)
return(err);
netif_start_queue(dev);
return 0;
}
static int dlci_close(struct net_device *dev)
{
struct dlci_local *dlp;
struct frad_local *flp;
int err;
netif_stop_queue(dev);
dlp = dev->priv;
flp = dlp->slave->priv;
err = (*flp->deactivate)(dlp->slave, dev);
return 0;
}
static struct net_device_stats *dlci_get_stats(struct net_device *dev)
{
struct dlci_local *dlp;
dlp = dev->priv;
return(&dlp->stats);
}
static int dlci_add(struct dlci_add *dlci)
{
struct net_device *master, *slave;
struct dlci_local *dlp;
struct frad_local *flp;
int err = -EINVAL;
/* validate slave device */
slave = dev_get_by_name(dlci->devname);
if (!slave)
return -ENODEV;
if (slave->type != ARPHRD_FRAD || slave->priv == NULL)
goto err1;
/* create device name */
master = alloc_netdev( sizeof(struct dlci_local), "dlci%d",
dlci_setup);
if (!master) {
err = -ENOMEM;
goto err1;
}
/* make sure same slave not already registered */
rtnl_lock();
list_for_each_entry(dlp, &dlci_devs, list) {
if (dlp->slave == slave) {
err = -EBUSY;
goto err2;
}
}
err = dev_alloc_name(master, master->name);
if (err < 0)
goto err2;
*(short *)(master->dev_addr) = dlci->dlci;
dlp = (struct dlci_local *) master->priv;
dlp->slave = slave;
dlp->master = master;
flp = slave->priv;
err = (*flp->assoc)(slave, master);
if (err < 0)
goto err2;
err = register_netdevice(master);
if (err < 0)
goto err2;
strcpy(dlci->devname, master->name);
list_add(&dlp->list, &dlci_devs);
rtnl_unlock();
return(0);
err2:
rtnl_unlock();
free_netdev(master);
err1:
dev_put(slave);
return(err);
}
static int dlci_del(struct dlci_add *dlci)
{
struct dlci_local *dlp;
struct frad_local *flp;
struct net_device *master, *slave;
int err;
/* validate slave device */
master = __dev_get_by_name(dlci->devname);
if (!master)
return(-ENODEV);
if (netif_running(master)) {
return(-EBUSY);
}
dlp = master->priv;
slave = dlp->slave;
flp = slave->priv;
rtnl_lock();
err = (*flp->deassoc)(slave, master);
if (!err) {
list_del(&dlp->list);
unregister_netdevice(master);
dev_put(slave);
}
rtnl_unlock();
return(err);
}
static int dlci_ioctl(unsigned int cmd, void __user *arg)
{
struct dlci_add add;
int err;
if (!capable(CAP_NET_ADMIN))
return(-EPERM);
if(copy_from_user(&add, arg, sizeof(struct dlci_add)))
return -EFAULT;
switch (cmd)
{
case SIOCADDDLCI:
err = dlci_add(&add);
if (!err)
if(copy_to_user(arg, &add, sizeof(struct dlci_add)))
return -EFAULT;
break;
case SIOCDELDLCI:
err = dlci_del(&add);
break;
default:
err = -EINVAL;
}
return(err);
}
static void dlci_setup(struct net_device *dev)
{
struct dlci_local *dlp = dev->priv;
dev->flags = 0;
dev->open = dlci_open;
dev->stop = dlci_close;
dev->do_ioctl = dlci_dev_ioctl;
dev->hard_start_xmit = dlci_transmit;
dev->hard_header = dlci_header;
dev->get_stats = dlci_get_stats;
dev->change_mtu = dlci_change_mtu;
dev->destructor = free_netdev;
dlp->receive = dlci_receive;
dev->type = ARPHRD_DLCI;
dev->hard_header_len = sizeof(struct frhdr);
dev->addr_len = sizeof(short);
}
/* if slave is unregistering, then cleanup master */
static int dlci_dev_event(struct notifier_block *unused,
unsigned long event, void *ptr)
{
struct net_device *dev = (struct net_device *) ptr;
if (event == NETDEV_UNREGISTER) {
struct dlci_local *dlp;
list_for_each_entry(dlp, &dlci_devs, list) {
if (dlp->slave == dev) {
list_del(&dlp->list);
unregister_netdevice(dlp->master);
dev_put(dlp->slave);
break;
}
}
}
return NOTIFY_DONE;
}
static struct notifier_block dlci_notifier = {
.notifier_call = dlci_dev_event,
};
static int __init init_dlci(void)
{
dlci_ioctl_set(dlci_ioctl);
register_netdevice_notifier(&dlci_notifier);
printk("%s.\n", version);
return 0;
}
static void __exit dlci_exit(void)
{
struct dlci_local *dlp, *nxt;
dlci_ioctl_set(NULL);
unregister_netdevice_notifier(&dlci_notifier);
rtnl_lock();
list_for_each_entry_safe(dlp, nxt, &dlci_devs, list) {
unregister_netdevice(dlp->master);
dev_put(dlp->slave);
}
rtnl_unlock();
}
module_init(init_dlci);
module_exit(dlci_exit);
MODULE_AUTHOR("Mike McLagan");
MODULE_DESCRIPTION("Frame Relay DLCI layer");
MODULE_LICENSE("GPL");
