/*
|
* slip.c This module implements the SLIP protocol for kernel-based
|
* devices like TTY. It interfaces between a raw TTY, and the
|
* kernel's INET protocol layers.
|
*
|
* Version: @(#)slip.c 0.8.3 12/24/94
|
*
|
* Authors: Laurence Culhane, <loz@holmes.demon.co.uk>
|
* Fred N. van Kempen, <waltje@uwalt.nl.mugnet.org>
|
*
|
* Fixes:
|
* Alan Cox : Sanity checks and avoid tx overruns.
|
* Has a new sl->mtu field.
|
* Alan Cox : Found cause of overrun. ifconfig sl0
|
* mtu upwards. Driver now spots this
|
* and grows/shrinks its buffers(hack!).
|
* Memory leak if you run out of memory
|
* setting up a slip driver fixed.
|
* Matt Dillon : Printable slip (borrowed from NET2E)
|
* Pauline Middelink : Slip driver fixes.
|
* Alan Cox : Honours the old SL_COMPRESSED flag
|
* Alan Cox : KISS AX.25 and AXUI IP support
|
* Michael Riepe : Automatic CSLIP recognition added
|
* Charles Hedrick : CSLIP header length problem fix.
|
* Alan Cox : Corrected non-IP cases of the above.
|
* Alan Cox : Now uses hardware type as per FvK.
|
* Alan Cox : Default to 192.168.0.0 (RFC 1597)
|
* A.N.Kuznetsov : dev_tint() recursion fix.
|
* Dmitry Gorodchanin : SLIP memory leaks
|
* Dmitry Gorodchanin : Code cleanup. Reduce tty driver
|
* buffering from 4096 to 256 bytes.
|
* Improving SLIP response time.
|
* CONFIG_SLIP_MODE_SLIP6.
|
* ifconfig sl? up & down now works
|
* correctly.
|
* Modularization.
|
* Alan Cox : Oops - fix AX.25 buffer lengths
|
* Dmitry Gorodchanin : Even more cleanups. Preserve CSLIP
|
* statistics. Include CSLIP code only
|
* if it really needed.
|
* Alan Cox : Free slhc buffers in the right place.
|
* Alan Cox : Allow for digipeated IP over AX.25
|
* Matti Aarnio : Dynamic SLIP devices, with ideas taken
|
* from Jim Freeman's <jfree@caldera.com>
|
* dynamic PPP devices. We do NOT kfree()
|
* device entries, just reg./unreg. them
|
* as they are needed. We kfree() them
|
* at module cleanup.
|
* With MODULE-loading ``insmod'', user
|
* can issue parameter: slip_maxdev=1024
|
* (Or how much he/she wants.. Default
|
* is 256)
|
* Stanislav Voronyi : Slip line checking, with ideas taken
|
* from multislip BSDI driver which was
|
* written by Igor Chechik, RELCOM Corp.
|
* Only algorithms have been ported to
|
* Linux SLIP driver.
|
* Vitaly E. Lavrov : Sane behaviour on tty hangup.
|
* Alexey Kuznetsov : Cleanup interfaces to tty & netdevice
|
* modules.
|
*/
|
|
#define SL_CHECK_TRANSMIT
|
#include <linux/module.h>
|
#include <linux/moduleparam.h>
|
|
#include <linux/uaccess.h>
|
#include <linux/bitops.h>
|
#include <linux/sched/signal.h>
|
#include <linux/string.h>
|
#include <linux/mm.h>
|
#include <linux/interrupt.h>
|
#include <linux/in.h>
|
#include <linux/tty.h>
|
#include <linux/errno.h>
|
#include <linux/netdevice.h>
|
#include <linux/etherdevice.h>
|
#include <linux/skbuff.h>
|
#include <linux/rtnetlink.h>
|
#include <linux/if_arp.h>
|
#include <linux/if_slip.h>
|
#include <linux/compat.h>
|
#include <linux/delay.h>
|
#include <linux/init.h>
|
#include <linux/slab.h>
|
#include <linux/workqueue.h>
|
#include "slip.h"
|
#ifdef CONFIG_INET
|
#include <linux/ip.h>
|
#include <linux/tcp.h>
|
#include <net/slhc_vj.h>
|
#endif
|
|
#define SLIP_VERSION "0.8.4-NET3.019-NEWTTY"
|
|
static struct net_device **slip_devs;
|
|
static int slip_maxdev = SL_NRUNIT;
|
module_param(slip_maxdev, int, 0);
|
MODULE_PARM_DESC(slip_maxdev, "Maximum number of slip devices");
|
|
static int slip_esc(unsigned char *p, unsigned char *d, int len);
|
static void slip_unesc(struct slip *sl, unsigned char c);
|
#ifdef CONFIG_SLIP_MODE_SLIP6
|
static int slip_esc6(unsigned char *p, unsigned char *d, int len);
|
static void slip_unesc6(struct slip *sl, unsigned char c);
|
#endif
|
#ifdef CONFIG_SLIP_SMART
|
static void sl_keepalive(struct timer_list *t);
|
static void sl_outfill(struct timer_list *t);
|
static int sl_ioctl(struct net_device *dev, struct ifreq *rq, int cmd);
|
#endif
|
|
/********************************
|
* Buffer administration routines:
|
* sl_alloc_bufs()
|
* sl_free_bufs()
|
* sl_realloc_bufs()
|
*
|
* NOTE: sl_realloc_bufs != sl_free_bufs + sl_alloc_bufs, because
|
* sl_realloc_bufs provides strong atomicity and reallocation
|
* on actively running device.
|
*********************************/
|
|
/*
|
Allocate channel buffers.
|
*/
|
|
static int sl_alloc_bufs(struct slip *sl, int mtu)
|
{
|
int err = -ENOBUFS;
|
unsigned long len;
|
char *rbuff = NULL;
|
char *xbuff = NULL;
|
#ifdef SL_INCLUDE_CSLIP
|
char *cbuff = NULL;
|
struct slcompress *slcomp = NULL;
|
#endif
|
|
/*
|
* Allocate the SLIP frame buffers:
|
*
|
* rbuff Receive buffer.
|
* xbuff Transmit buffer.
|
* cbuff Temporary compression buffer.
|
*/
|
len = mtu * 2;
|
|
/*
|
* allow for arrival of larger UDP packets, even if we say not to
|
* also fixes a bug in which SunOS sends 512-byte packets even with
|
* an MSS of 128
|
*/
|
if (len < 576 * 2)
|
len = 576 * 2;
|
rbuff = kmalloc(len + 4, GFP_KERNEL);
|
if (rbuff == NULL)
|
goto err_exit;
|
xbuff = kmalloc(len + 4, GFP_KERNEL);
|
if (xbuff == NULL)
|
goto err_exit;
|
#ifdef SL_INCLUDE_CSLIP
|
cbuff = kmalloc(len + 4, GFP_KERNEL);
|
if (cbuff == NULL)
|
goto err_exit;
|
slcomp = slhc_init(16, 16);
|
if (IS_ERR(slcomp))
|
goto err_exit;
|
#endif
|
spin_lock_bh(&sl->lock);
|
if (sl->tty == NULL) {
|
spin_unlock_bh(&sl->lock);
|
err = -ENODEV;
|
goto err_exit;
|
}
|
sl->mtu = mtu;
|
sl->buffsize = len;
|
sl->rcount = 0;
|
sl->xleft = 0;
|
rbuff = xchg(&sl->rbuff, rbuff);
|
xbuff = xchg(&sl->xbuff, xbuff);
|
#ifdef SL_INCLUDE_CSLIP
|
cbuff = xchg(&sl->cbuff, cbuff);
|
slcomp = xchg(&sl->slcomp, slcomp);
|
#endif
|
#ifdef CONFIG_SLIP_MODE_SLIP6
|
sl->xdata = 0;
|
sl->xbits = 0;
|
#endif
|
spin_unlock_bh(&sl->lock);
|
err = 0;
|
|
/* Cleanup */
|
err_exit:
|
#ifdef SL_INCLUDE_CSLIP
|
kfree(cbuff);
|
slhc_free(slcomp);
|
#endif
|
kfree(xbuff);
|
kfree(rbuff);
|
return err;
|
}
|
|
/* Free a SLIP channel buffers. */
|
static void sl_free_bufs(struct slip *sl)
|
{
|
/* Free all SLIP frame buffers. */
|
kfree(xchg(&sl->rbuff, NULL));
|
kfree(xchg(&sl->xbuff, NULL));
|
#ifdef SL_INCLUDE_CSLIP
|
kfree(xchg(&sl->cbuff, NULL));
|
slhc_free(xchg(&sl->slcomp, NULL));
|
#endif
|
}
|
|
/*
|
Reallocate slip channel buffers.
|
*/
|
|
static int sl_realloc_bufs(struct slip *sl, int mtu)
|
{
|
int err = 0;
|
struct net_device *dev = sl->dev;
|
unsigned char *xbuff, *rbuff;
|
#ifdef SL_INCLUDE_CSLIP
|
unsigned char *cbuff;
|
#endif
|
int len = mtu * 2;
|
|
/*
|
* allow for arrival of larger UDP packets, even if we say not to
|
* also fixes a bug in which SunOS sends 512-byte packets even with
|
* an MSS of 128
|
*/
|
if (len < 576 * 2)
|
len = 576 * 2;
|
|
xbuff = kmalloc(len + 4, GFP_ATOMIC);
|
rbuff = kmalloc(len + 4, GFP_ATOMIC);
|
#ifdef SL_INCLUDE_CSLIP
|
cbuff = kmalloc(len + 4, GFP_ATOMIC);
|
#endif
|
|
|
#ifdef SL_INCLUDE_CSLIP
|
if (xbuff == NULL || rbuff == NULL || cbuff == NULL) {
|
#else
|
if (xbuff == NULL || rbuff == NULL) {
|
#endif
|
if (mtu > sl->mtu) {
|
printk(KERN_WARNING "%s: unable to grow slip buffers, MTU change cancelled.\n",
|
dev->name);
|
err = -ENOBUFS;
|
}
|
goto done;
|
}
|
spin_lock_bh(&sl->lock);
|
|
err = -ENODEV;
|
if (sl->tty == NULL)
|
goto done_on_bh;
|
|
xbuff = xchg(&sl->xbuff, xbuff);
|
rbuff = xchg(&sl->rbuff, rbuff);
|
#ifdef SL_INCLUDE_CSLIP
|
cbuff = xchg(&sl->cbuff, cbuff);
|
#endif
|
if (sl->xleft) {
|
if (sl->xleft <= len) {
|
memcpy(sl->xbuff, sl->xhead, sl->xleft);
|
} else {
|
sl->xleft = 0;
|
dev->stats.tx_dropped++;
|
}
|
}
|
sl->xhead = sl->xbuff;
|
|
if (sl->rcount) {
|
if (sl->rcount <= len) {
|
memcpy(sl->rbuff, rbuff, sl->rcount);
|
} else {
|
sl->rcount = 0;
|
dev->stats.rx_over_errors++;
|
set_bit(SLF_ERROR, &sl->flags);
|
}
|
}
|
sl->mtu = mtu;
|
dev->mtu = mtu;
|
sl->buffsize = len;
|
err = 0;
|
|
done_on_bh:
|
spin_unlock_bh(&sl->lock);
|
|
done:
|
kfree(xbuff);
|
kfree(rbuff);
|
#ifdef SL_INCLUDE_CSLIP
|
kfree(cbuff);
|
#endif
|
return err;
|
}
|
|
|
/* Set the "sending" flag. This must be atomic hence the set_bit. */
|
static inline void sl_lock(struct slip *sl)
|
{
|
netif_stop_queue(sl->dev);
|
}
|
|
|
/* Clear the "sending" flag. This must be atomic, hence the ASM. */
|
static inline void sl_unlock(struct slip *sl)
|
{
|
netif_wake_queue(sl->dev);
|
}
|
|
/* Send one completely decapsulated IP datagram to the IP layer. */
|
static void sl_bump(struct slip *sl)
|
{
|
struct net_device *dev = sl->dev;
|
struct sk_buff *skb;
|
int count;
|
|
count = sl->rcount;
|
#ifdef SL_INCLUDE_CSLIP
|
if (sl->mode & (SL_MODE_ADAPTIVE | SL_MODE_CSLIP)) {
|
unsigned char c = sl->rbuff[0];
|
if (c & SL_TYPE_COMPRESSED_TCP) {
|
/* ignore compressed packets when CSLIP is off */
|
if (!(sl->mode & SL_MODE_CSLIP)) {
|
printk(KERN_WARNING "%s: compressed packet ignored\n", dev->name);
|
return;
|
}
|
/* make sure we've reserved enough space for uncompress
|
to use */
|
if (count + 80 > sl->buffsize) {
|
dev->stats.rx_over_errors++;
|
return;
|
}
|
count = slhc_uncompress(sl->slcomp, sl->rbuff, count);
|
if (count <= 0)
|
return;
|
} else if (c >= SL_TYPE_UNCOMPRESSED_TCP) {
|
if (!(sl->mode & SL_MODE_CSLIP)) {
|
/* turn on header compression */
|
sl->mode |= SL_MODE_CSLIP;
|
sl->mode &= ~SL_MODE_ADAPTIVE;
|
printk(KERN_INFO "%s: header compression turned on\n", dev->name);
|
}
|
sl->rbuff[0] &= 0x4f;
|
if (slhc_remember(sl->slcomp, sl->rbuff, count) <= 0)
|
return;
|
}
|
}
|
#endif /* SL_INCLUDE_CSLIP */
|
|
dev->stats.rx_bytes += count;
|
|
skb = dev_alloc_skb(count);
|
if (skb == NULL) {
|
printk(KERN_WARNING "%s: memory squeeze, dropping packet.\n", dev->name);
|
dev->stats.rx_dropped++;
|
return;
|
}
|
skb->dev = dev;
|
skb_put_data(skb, sl->rbuff, count);
|
skb_reset_mac_header(skb);
|
skb->protocol = htons(ETH_P_IP);
|
netif_rx_ni(skb);
|
dev->stats.rx_packets++;
|
}
|
|
/* Encapsulate one IP datagram and stuff into a TTY queue. */
|
static void sl_encaps(struct slip *sl, unsigned char *icp, int len)
|
{
|
unsigned char *p;
|
int actual, count;
|
|
if (len > sl->mtu) { /* Sigh, shouldn't occur BUT ... */
|
printk(KERN_WARNING "%s: truncating oversized transmit packet!\n", sl->dev->name);
|
sl->dev->stats.tx_dropped++;
|
sl_unlock(sl);
|
return;
|
}
|
|
p = icp;
|
#ifdef SL_INCLUDE_CSLIP
|
if (sl->mode & SL_MODE_CSLIP)
|
len = slhc_compress(sl->slcomp, p, len, sl->cbuff, &p, 1);
|
#endif
|
#ifdef CONFIG_SLIP_MODE_SLIP6
|
if (sl->mode & SL_MODE_SLIP6)
|
count = slip_esc6(p, sl->xbuff, len);
|
else
|
#endif
|
count = slip_esc(p, sl->xbuff, len);
|
|
/* Order of next two lines is *very* important.
|
* When we are sending a little amount of data,
|
* the transfer may be completed inside the ops->write()
|
* routine, because it's running with interrupts enabled.
|
* In this case we *never* got WRITE_WAKEUP event,
|
* if we did not request it before write operation.
|
* 14 Oct 1994 Dmitry Gorodchanin.
|
*/
|
set_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
|
actual = sl->tty->ops->write(sl->tty, sl->xbuff, count);
|
#ifdef SL_CHECK_TRANSMIT
|
netif_trans_update(sl->dev);
|
#endif
|
sl->xleft = count - actual;
|
sl->xhead = sl->xbuff + actual;
|
#ifdef CONFIG_SLIP_SMART
|
/* VSV */
|
clear_bit(SLF_OUTWAIT, &sl->flags); /* reset outfill flag */
|
#endif
|
}
|
|
/* Write out any remaining transmit buffer. Scheduled when tty is writable */
|
static void slip_transmit(struct work_struct *work)
|
{
|
struct slip *sl = container_of(work, struct slip, tx_work);
|
int actual;
|
|
spin_lock_bh(&sl->lock);
|
/* First make sure we're connected. */
|
if (!sl->tty || sl->magic != SLIP_MAGIC || !netif_running(sl->dev)) {
|
spin_unlock_bh(&sl->lock);
|
return;
|
}
|
|
if (sl->xleft <= 0) {
|
/* Now serial buffer is almost free & we can start
|
* transmission of another packet */
|
sl->dev->stats.tx_packets++;
|
clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
|
spin_unlock_bh(&sl->lock);
|
sl_unlock(sl);
|
return;
|
}
|
|
actual = sl->tty->ops->write(sl->tty, sl->xhead, sl->xleft);
|
sl->xleft -= actual;
|
sl->xhead += actual;
|
spin_unlock_bh(&sl->lock);
|
}
|
|
/*
|
* Called by the driver when there's room for more data.
|
* Schedule the transmit.
|
*/
|
static void slip_write_wakeup(struct tty_struct *tty)
|
{
|
struct slip *sl;
|
|
rcu_read_lock();
|
sl = rcu_dereference(tty->disc_data);
|
if (!sl)
|
goto out;
|
|
schedule_work(&sl->tx_work);
|
out:
|
rcu_read_unlock();
|
}
|
|
static void sl_tx_timeout(struct net_device *dev)
|
{
|
struct slip *sl = netdev_priv(dev);
|
|
spin_lock(&sl->lock);
|
|
if (netif_queue_stopped(dev)) {
|
if (!netif_running(dev))
|
goto out;
|
|
/* May be we must check transmitter timeout here ?
|
* 14 Oct 1994 Dmitry Gorodchanin.
|
*/
|
#ifdef SL_CHECK_TRANSMIT
|
if (time_before(jiffies, dev_trans_start(dev) + 20 * HZ)) {
|
/* 20 sec timeout not reached */
|
goto out;
|
}
|
printk(KERN_WARNING "%s: transmit timed out, %s?\n",
|
dev->name,
|
(tty_chars_in_buffer(sl->tty) || sl->xleft) ?
|
"bad line quality" : "driver error");
|
sl->xleft = 0;
|
clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
|
sl_unlock(sl);
|
#endif
|
}
|
out:
|
spin_unlock(&sl->lock);
|
}
|
|
|
/* Encapsulate an IP datagram and kick it into a TTY queue. */
|
static netdev_tx_t
|
sl_xmit(struct sk_buff *skb, struct net_device *dev)
|
{
|
struct slip *sl = netdev_priv(dev);
|
|
spin_lock(&sl->lock);
|
if (!netif_running(dev)) {
|
spin_unlock(&sl->lock);
|
printk(KERN_WARNING "%s: xmit call when iface is down\n", dev->name);
|
dev_kfree_skb(skb);
|
return NETDEV_TX_OK;
|
}
|
if (sl->tty == NULL) {
|
spin_unlock(&sl->lock);
|
dev_kfree_skb(skb);
|
return NETDEV_TX_OK;
|
}
|
|
sl_lock(sl);
|
dev->stats.tx_bytes += skb->len;
|
sl_encaps(sl, skb->data, skb->len);
|
spin_unlock(&sl->lock);
|
|
dev_kfree_skb(skb);
|
return NETDEV_TX_OK;
|
}
|
|
|
/******************************************
|
* Routines looking at netdevice side.
|
******************************************/
|
|
/* Netdevice UP -> DOWN routine */
|
|
static int
|
sl_close(struct net_device *dev)
|
{
|
struct slip *sl = netdev_priv(dev);
|
|
spin_lock_bh(&sl->lock);
|
if (sl->tty)
|
/* TTY discipline is running. */
|
clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
|
netif_stop_queue(dev);
|
sl->rcount = 0;
|
sl->xleft = 0;
|
spin_unlock_bh(&sl->lock);
|
|
return 0;
|
}
|
|
/* Netdevice DOWN -> UP routine */
|
|
static int sl_open(struct net_device *dev)
|
{
|
struct slip *sl = netdev_priv(dev);
|
|
if (sl->tty == NULL)
|
return -ENODEV;
|
|
sl->flags &= (1 << SLF_INUSE);
|
netif_start_queue(dev);
|
return 0;
|
}
|
|
/* Netdevice change MTU request */
|
|
static int sl_change_mtu(struct net_device *dev, int new_mtu)
|
{
|
struct slip *sl = netdev_priv(dev);
|
|
return sl_realloc_bufs(sl, new_mtu);
|
}
|
|
/* Netdevice get statistics request */
|
|
static void
|
sl_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
|
{
|
struct net_device_stats *devstats = &dev->stats;
|
#ifdef SL_INCLUDE_CSLIP
|
struct slip *sl = netdev_priv(dev);
|
struct slcompress *comp = sl->slcomp;
|
#endif
|
stats->rx_packets = devstats->rx_packets;
|
stats->tx_packets = devstats->tx_packets;
|
stats->rx_bytes = devstats->rx_bytes;
|
stats->tx_bytes = devstats->tx_bytes;
|
stats->rx_dropped = devstats->rx_dropped;
|
stats->tx_dropped = devstats->tx_dropped;
|
stats->tx_errors = devstats->tx_errors;
|
stats->rx_errors = devstats->rx_errors;
|
stats->rx_over_errors = devstats->rx_over_errors;
|
|
#ifdef SL_INCLUDE_CSLIP
|
if (comp) {
|
/* Generic compressed statistics */
|
stats->rx_compressed = comp->sls_i_compressed;
|
stats->tx_compressed = comp->sls_o_compressed;
|
|
/* Are we really still needs this? */
|
stats->rx_fifo_errors += comp->sls_i_compressed;
|
stats->rx_dropped += comp->sls_i_tossed;
|
stats->tx_fifo_errors += comp->sls_o_compressed;
|
stats->collisions += comp->sls_o_misses;
|
}
|
#endif
|
}
|
|
/* Netdevice register callback */
|
|
static int sl_init(struct net_device *dev)
|
{
|
struct slip *sl = netdev_priv(dev);
|
|
/*
|
* Finish setting up the DEVICE info.
|
*/
|
|
dev->mtu = sl->mtu;
|
dev->type = ARPHRD_SLIP + sl->mode;
|
#ifdef SL_CHECK_TRANSMIT
|
dev->watchdog_timeo = 20*HZ;
|
#endif
|
return 0;
|
}
|
|
|
static void sl_uninit(struct net_device *dev)
|
{
|
struct slip *sl = netdev_priv(dev);
|
|
sl_free_bufs(sl);
|
}
|
|
/* Hook the destructor so we can free slip devices at the right point in time */
|
static void sl_free_netdev(struct net_device *dev)
|
{
|
int i = dev->base_addr;
|
|
slip_devs[i] = NULL;
|
}
|
|
static const struct net_device_ops sl_netdev_ops = {
|
.ndo_init = sl_init,
|
.ndo_uninit = sl_uninit,
|
.ndo_open = sl_open,
|
.ndo_stop = sl_close,
|
.ndo_start_xmit = sl_xmit,
|
.ndo_get_stats64 = sl_get_stats64,
|
.ndo_change_mtu = sl_change_mtu,
|
.ndo_tx_timeout = sl_tx_timeout,
|
#ifdef CONFIG_SLIP_SMART
|
.ndo_do_ioctl = sl_ioctl,
|
#endif
|
};
|
|
|
static void sl_setup(struct net_device *dev)
|
{
|
dev->netdev_ops = &sl_netdev_ops;
|
dev->needs_free_netdev = true;
|
dev->priv_destructor = sl_free_netdev;
|
|
dev->hard_header_len = 0;
|
dev->addr_len = 0;
|
dev->tx_queue_len = 10;
|
|
/* MTU range: 68 - 65534 */
|
dev->min_mtu = 68;
|
dev->max_mtu = 65534;
|
|
/* New-style flags. */
|
dev->flags = IFF_NOARP|IFF_POINTOPOINT|IFF_MULTICAST;
|
}
|
|
/******************************************
|
Routines looking at TTY side.
|
******************************************/
|
|
|
/*
|
* Handle the 'receiver data ready' interrupt.
|
* This function is called by the 'tty_io' module in the kernel when
|
* a block of SLIP data has been received, which can now be decapsulated
|
* and sent on to some IP layer for further processing. This will not
|
* be re-entered while running but other ldisc functions may be called
|
* in parallel
|
*/
|
|
static void slip_receive_buf(struct tty_struct *tty, const unsigned char *cp,
|
char *fp, int count)
|
{
|
struct slip *sl = tty->disc_data;
|
|
if (!sl || sl->magic != SLIP_MAGIC || !netif_running(sl->dev))
|
return;
|
|
/* Read the characters out of the buffer */
|
while (count--) {
|
if (fp && *fp++) {
|
if (!test_and_set_bit(SLF_ERROR, &sl->flags))
|
sl->dev->stats.rx_errors++;
|
cp++;
|
continue;
|
}
|
#ifdef CONFIG_SLIP_MODE_SLIP6
|
if (sl->mode & SL_MODE_SLIP6)
|
slip_unesc6(sl, *cp++);
|
else
|
#endif
|
slip_unesc(sl, *cp++);
|
}
|
}
|
|
/************************************
|
* slip_open helper routines.
|
************************************/
|
|
/* Collect hanged up channels */
|
static void sl_sync(void)
|
{
|
int i;
|
struct net_device *dev;
|
struct slip *sl;
|
|
for (i = 0; i < slip_maxdev; i++) {
|
dev = slip_devs[i];
|
if (dev == NULL)
|
break;
|
|
sl = netdev_priv(dev);
|
if (sl->tty || sl->leased)
|
continue;
|
if (dev->flags & IFF_UP)
|
dev_close(dev);
|
}
|
}
|
|
|
/* Find a free SLIP channel, and link in this `tty' line. */
|
static struct slip *sl_alloc(void)
|
{
|
int i;
|
char name[IFNAMSIZ];
|
struct net_device *dev = NULL;
|
struct slip *sl;
|
|
for (i = 0; i < slip_maxdev; i++) {
|
dev = slip_devs[i];
|
if (dev == NULL)
|
break;
|
}
|
/* Sorry, too many, all slots in use */
|
if (i >= slip_maxdev)
|
return NULL;
|
|
sprintf(name, "sl%d", i);
|
dev = alloc_netdev(sizeof(*sl), name, NET_NAME_UNKNOWN, sl_setup);
|
if (!dev)
|
return NULL;
|
|
dev->base_addr = i;
|
sl = netdev_priv(dev);
|
|
/* Initialize channel control data */
|
sl->magic = SLIP_MAGIC;
|
sl->dev = dev;
|
spin_lock_init(&sl->lock);
|
INIT_WORK(&sl->tx_work, slip_transmit);
|
sl->mode = SL_MODE_DEFAULT;
|
#ifdef CONFIG_SLIP_SMART
|
/* initialize timer_list struct */
|
timer_setup(&sl->keepalive_timer, sl_keepalive, 0);
|
timer_setup(&sl->outfill_timer, sl_outfill, 0);
|
#endif
|
slip_devs[i] = dev;
|
return sl;
|
}
|
|
/*
|
* Open the high-level part of the SLIP channel.
|
* This function is called by the TTY module when the
|
* SLIP line discipline is called for. Because we are
|
* sure the tty line exists, we only have to link it to
|
* a free SLIP channel...
|
*
|
* Called in process context serialized from other ldisc calls.
|
*/
|
|
static int slip_open(struct tty_struct *tty)
|
{
|
struct slip *sl;
|
int err;
|
|
if (!capable(CAP_NET_ADMIN))
|
return -EPERM;
|
|
if (tty->ops->write == NULL)
|
return -EOPNOTSUPP;
|
|
/* RTnetlink lock is misused here to serialize concurrent
|
opens of slip channels. There are better ways, but it is
|
the simplest one.
|
*/
|
rtnl_lock();
|
|
/* Collect hanged up channels. */
|
sl_sync();
|
|
sl = tty->disc_data;
|
|
err = -EEXIST;
|
/* First make sure we're not already connected. */
|
if (sl && sl->magic == SLIP_MAGIC)
|
goto err_exit;
|
|
/* OK. Find a free SLIP channel to use. */
|
err = -ENFILE;
|
sl = sl_alloc();
|
if (sl == NULL)
|
goto err_exit;
|
|
sl->tty = tty;
|
tty->disc_data = sl;
|
sl->pid = current->pid;
|
|
if (!test_bit(SLF_INUSE, &sl->flags)) {
|
/* Perform the low-level SLIP initialization. */
|
err = sl_alloc_bufs(sl, SL_MTU);
|
if (err)
|
goto err_free_chan;
|
|
set_bit(SLF_INUSE, &sl->flags);
|
|
err = register_netdevice(sl->dev);
|
if (err)
|
goto err_free_bufs;
|
}
|
|
#ifdef CONFIG_SLIP_SMART
|
if (sl->keepalive) {
|
sl->keepalive_timer.expires = jiffies + sl->keepalive * HZ;
|
add_timer(&sl->keepalive_timer);
|
}
|
if (sl->outfill) {
|
sl->outfill_timer.expires = jiffies + sl->outfill * HZ;
|
add_timer(&sl->outfill_timer);
|
}
|
#endif
|
|
/* Done. We have linked the TTY line to a channel. */
|
rtnl_unlock();
|
tty->receive_room = 65536; /* We don't flow control */
|
|
/* TTY layer expects 0 on success */
|
return 0;
|
|
err_free_bufs:
|
sl_free_bufs(sl);
|
|
err_free_chan:
|
sl->tty = NULL;
|
tty->disc_data = NULL;
|
clear_bit(SLF_INUSE, &sl->flags);
|
sl_free_netdev(sl->dev);
|
/* do not call free_netdev before rtnl_unlock */
|
rtnl_unlock();
|
free_netdev(sl->dev);
|
return err;
|
|
err_exit:
|
rtnl_unlock();
|
|
/* Count references from TTY module */
|
return err;
|
}
|
|
/*
|
* Close down a SLIP channel.
|
* This means flushing out any pending queues, and then returning. This
|
* call is serialized against other ldisc functions.
|
*
|
* We also use this method fo a hangup event
|
*/
|
|
static void slip_close(struct tty_struct *tty)
|
{
|
struct slip *sl = tty->disc_data;
|
|
/* First make sure we're connected. */
|
if (!sl || sl->magic != SLIP_MAGIC || sl->tty != tty)
|
return;
|
|
spin_lock_bh(&sl->lock);
|
rcu_assign_pointer(tty->disc_data, NULL);
|
sl->tty = NULL;
|
spin_unlock_bh(&sl->lock);
|
|
synchronize_rcu();
|
flush_work(&sl->tx_work);
|
|
/* VSV = very important to remove timers */
|
#ifdef CONFIG_SLIP_SMART
|
del_timer_sync(&sl->keepalive_timer);
|
del_timer_sync(&sl->outfill_timer);
|
#endif
|
/* Flush network side */
|
unregister_netdev(sl->dev);
|
/* This will complete via sl_free_netdev */
|
}
|
|
static int slip_hangup(struct tty_struct *tty)
|
{
|
slip_close(tty);
|
return 0;
|
}
|
/************************************************************************
|
* STANDARD SLIP ENCAPSULATION *
|
************************************************************************/
|
|
static int slip_esc(unsigned char *s, unsigned char *d, int len)
|
{
|
unsigned char *ptr = d;
|
unsigned char c;
|
|
/*
|
* Send an initial END character to flush out any
|
* data that may have accumulated in the receiver
|
* due to line noise.
|
*/
|
|
*ptr++ = END;
|
|
/*
|
* For each byte in the packet, send the appropriate
|
* character sequence, according to the SLIP protocol.
|
*/
|
|
while (len-- > 0) {
|
switch (c = *s++) {
|
case END:
|
*ptr++ = ESC;
|
*ptr++ = ESC_END;
|
break;
|
case ESC:
|
*ptr++ = ESC;
|
*ptr++ = ESC_ESC;
|
break;
|
default:
|
*ptr++ = c;
|
break;
|
}
|
}
|
*ptr++ = END;
|
return ptr - d;
|
}
|
|
static void slip_unesc(struct slip *sl, unsigned char s)
|
{
|
|
switch (s) {
|
case END:
|
#ifdef CONFIG_SLIP_SMART
|
/* drop keeptest bit = VSV */
|
if (test_bit(SLF_KEEPTEST, &sl->flags))
|
clear_bit(SLF_KEEPTEST, &sl->flags);
|
#endif
|
|
if (!test_and_clear_bit(SLF_ERROR, &sl->flags) &&
|
(sl->rcount > 2))
|
sl_bump(sl);
|
clear_bit(SLF_ESCAPE, &sl->flags);
|
sl->rcount = 0;
|
return;
|
|
case ESC:
|
set_bit(SLF_ESCAPE, &sl->flags);
|
return;
|
case ESC_ESC:
|
if (test_and_clear_bit(SLF_ESCAPE, &sl->flags))
|
s = ESC;
|
break;
|
case ESC_END:
|
if (test_and_clear_bit(SLF_ESCAPE, &sl->flags))
|
s = END;
|
break;
|
}
|
if (!test_bit(SLF_ERROR, &sl->flags)) {
|
if (sl->rcount < sl->buffsize) {
|
sl->rbuff[sl->rcount++] = s;
|
return;
|
}
|
sl->dev->stats.rx_over_errors++;
|
set_bit(SLF_ERROR, &sl->flags);
|
}
|
}
|
|
|
#ifdef CONFIG_SLIP_MODE_SLIP6
|
/************************************************************************
|
* 6 BIT SLIP ENCAPSULATION *
|
************************************************************************/
|
|
static int slip_esc6(unsigned char *s, unsigned char *d, int len)
|
{
|
unsigned char *ptr = d;
|
unsigned char c;
|
int i;
|
unsigned short v = 0;
|
short bits = 0;
|
|
/*
|
* Send an initial END character to flush out any
|
* data that may have accumulated in the receiver
|
* due to line noise.
|
*/
|
|
*ptr++ = 0x70;
|
|
/*
|
* Encode the packet into printable ascii characters
|
*/
|
|
for (i = 0; i < len; ++i) {
|
v = (v << 8) | s[i];
|
bits += 8;
|
while (bits >= 6) {
|
bits -= 6;
|
c = 0x30 + ((v >> bits) & 0x3F);
|
*ptr++ = c;
|
}
|
}
|
if (bits) {
|
c = 0x30 + ((v << (6 - bits)) & 0x3F);
|
*ptr++ = c;
|
}
|
*ptr++ = 0x70;
|
return ptr - d;
|
}
|
|
static void slip_unesc6(struct slip *sl, unsigned char s)
|
{
|
unsigned char c;
|
|
if (s == 0x70) {
|
#ifdef CONFIG_SLIP_SMART
|
/* drop keeptest bit = VSV */
|
if (test_bit(SLF_KEEPTEST, &sl->flags))
|
clear_bit(SLF_KEEPTEST, &sl->flags);
|
#endif
|
|
if (!test_and_clear_bit(SLF_ERROR, &sl->flags) &&
|
(sl->rcount > 2))
|
sl_bump(sl);
|
sl->rcount = 0;
|
sl->xbits = 0;
|
sl->xdata = 0;
|
} else if (s >= 0x30 && s < 0x70) {
|
sl->xdata = (sl->xdata << 6) | ((s - 0x30) & 0x3F);
|
sl->xbits += 6;
|
if (sl->xbits >= 8) {
|
sl->xbits -= 8;
|
c = (unsigned char)(sl->xdata >> sl->xbits);
|
if (!test_bit(SLF_ERROR, &sl->flags)) {
|
if (sl->rcount < sl->buffsize) {
|
sl->rbuff[sl->rcount++] = c;
|
return;
|
}
|
sl->dev->stats.rx_over_errors++;
|
set_bit(SLF_ERROR, &sl->flags);
|
}
|
}
|
}
|
}
|
#endif /* CONFIG_SLIP_MODE_SLIP6 */
|
|
/* Perform I/O control on an active SLIP channel. */
|
static int slip_ioctl(struct tty_struct *tty, struct file *file,
|
unsigned int cmd, unsigned long arg)
|
{
|
struct slip *sl = tty->disc_data;
|
unsigned int tmp;
|
int __user *p = (int __user *)arg;
|
|
/* First make sure we're connected. */
|
if (!sl || sl->magic != SLIP_MAGIC)
|
return -EINVAL;
|
|
switch (cmd) {
|
case SIOCGIFNAME:
|
tmp = strlen(sl->dev->name) + 1;
|
if (copy_to_user((void __user *)arg, sl->dev->name, tmp))
|
return -EFAULT;
|
return 0;
|
|
case SIOCGIFENCAP:
|
if (put_user(sl->mode, p))
|
return -EFAULT;
|
return 0;
|
|
case SIOCSIFENCAP:
|
if (get_user(tmp, p))
|
return -EFAULT;
|
#ifndef SL_INCLUDE_CSLIP
|
if (tmp & (SL_MODE_CSLIP|SL_MODE_ADAPTIVE))
|
return -EINVAL;
|
#else
|
if ((tmp & (SL_MODE_ADAPTIVE | SL_MODE_CSLIP)) ==
|
(SL_MODE_ADAPTIVE | SL_MODE_CSLIP))
|
/* return -EINVAL; */
|
tmp &= ~SL_MODE_ADAPTIVE;
|
#endif
|
#ifndef CONFIG_SLIP_MODE_SLIP6
|
if (tmp & SL_MODE_SLIP6)
|
return -EINVAL;
|
#endif
|
sl->mode = tmp;
|
sl->dev->type = ARPHRD_SLIP + sl->mode;
|
return 0;
|
|
case SIOCSIFHWADDR:
|
return -EINVAL;
|
|
#ifdef CONFIG_SLIP_SMART
|
/* VSV changes start here */
|
case SIOCSKEEPALIVE:
|
if (get_user(tmp, p))
|
return -EFAULT;
|
if (tmp > 255) /* max for unchar */
|
return -EINVAL;
|
|
spin_lock_bh(&sl->lock);
|
if (!sl->tty) {
|
spin_unlock_bh(&sl->lock);
|
return -ENODEV;
|
}
|
sl->keepalive = (u8)tmp;
|
if (sl->keepalive != 0) {
|
mod_timer(&sl->keepalive_timer,
|
jiffies + sl->keepalive * HZ);
|
set_bit(SLF_KEEPTEST, &sl->flags);
|
} else
|
del_timer(&sl->keepalive_timer);
|
spin_unlock_bh(&sl->lock);
|
return 0;
|
|
case SIOCGKEEPALIVE:
|
if (put_user(sl->keepalive, p))
|
return -EFAULT;
|
return 0;
|
|
case SIOCSOUTFILL:
|
if (get_user(tmp, p))
|
return -EFAULT;
|
if (tmp > 255) /* max for unchar */
|
return -EINVAL;
|
spin_lock_bh(&sl->lock);
|
if (!sl->tty) {
|
spin_unlock_bh(&sl->lock);
|
return -ENODEV;
|
}
|
sl->outfill = (u8)tmp;
|
if (sl->outfill != 0) {
|
mod_timer(&sl->outfill_timer,
|
jiffies + sl->outfill * HZ);
|
set_bit(SLF_OUTWAIT, &sl->flags);
|
} else
|
del_timer(&sl->outfill_timer);
|
spin_unlock_bh(&sl->lock);
|
return 0;
|
|
case SIOCGOUTFILL:
|
if (put_user(sl->outfill, p))
|
return -EFAULT;
|
return 0;
|
/* VSV changes end */
|
#endif
|
default:
|
return tty_mode_ioctl(tty, file, cmd, arg);
|
}
|
}
|
|
#ifdef CONFIG_COMPAT
|
static long slip_compat_ioctl(struct tty_struct *tty, struct file *file,
|
unsigned int cmd, unsigned long arg)
|
{
|
switch (cmd) {
|
case SIOCGIFNAME:
|
case SIOCGIFENCAP:
|
case SIOCSIFENCAP:
|
case SIOCSIFHWADDR:
|
case SIOCSKEEPALIVE:
|
case SIOCGKEEPALIVE:
|
case SIOCSOUTFILL:
|
case SIOCGOUTFILL:
|
return slip_ioctl(tty, file, cmd,
|
(unsigned long)compat_ptr(arg));
|
}
|
|
return -ENOIOCTLCMD;
|
}
|
#endif
|
|
/* VSV changes start here */
|
#ifdef CONFIG_SLIP_SMART
|
/* function do_ioctl called from net/core/dev.c
|
to allow get/set outfill/keepalive parameter
|
by ifconfig */
|
|
static int sl_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
|
{
|
struct slip *sl = netdev_priv(dev);
|
unsigned long *p = (unsigned long *)&rq->ifr_ifru;
|
|
if (sl == NULL) /* Allocation failed ?? */
|
return -ENODEV;
|
|
spin_lock_bh(&sl->lock);
|
|
if (!sl->tty) {
|
spin_unlock_bh(&sl->lock);
|
return -ENODEV;
|
}
|
|
switch (cmd) {
|
case SIOCSKEEPALIVE:
|
/* max for unchar */
|
if ((unsigned)*p > 255) {
|
spin_unlock_bh(&sl->lock);
|
return -EINVAL;
|
}
|
sl->keepalive = (u8)*p;
|
if (sl->keepalive != 0) {
|
sl->keepalive_timer.expires =
|
jiffies + sl->keepalive * HZ;
|
mod_timer(&sl->keepalive_timer,
|
jiffies + sl->keepalive * HZ);
|
set_bit(SLF_KEEPTEST, &sl->flags);
|
} else
|
del_timer(&sl->keepalive_timer);
|
break;
|
|
case SIOCGKEEPALIVE:
|
*p = sl->keepalive;
|
break;
|
|
case SIOCSOUTFILL:
|
if ((unsigned)*p > 255) { /* max for unchar */
|
spin_unlock_bh(&sl->lock);
|
return -EINVAL;
|
}
|
sl->outfill = (u8)*p;
|
if (sl->outfill != 0) {
|
mod_timer(&sl->outfill_timer,
|
jiffies + sl->outfill * HZ);
|
set_bit(SLF_OUTWAIT, &sl->flags);
|
} else
|
del_timer(&sl->outfill_timer);
|
break;
|
|
case SIOCGOUTFILL:
|
*p = sl->outfill;
|
break;
|
|
case SIOCSLEASE:
|
/* Resolve race condition, when ioctl'ing hanged up
|
and opened by another process device.
|
*/
|
if (sl->tty != current->signal->tty &&
|
sl->pid != current->pid) {
|
spin_unlock_bh(&sl->lock);
|
return -EPERM;
|
}
|
sl->leased = 0;
|
if (*p)
|
sl->leased = 1;
|
break;
|
|
case SIOCGLEASE:
|
*p = sl->leased;
|
}
|
spin_unlock_bh(&sl->lock);
|
return 0;
|
}
|
#endif
|
/* VSV changes end */
|
|
static struct tty_ldisc_ops sl_ldisc = {
|
.owner = THIS_MODULE,
|
.magic = TTY_LDISC_MAGIC,
|
.name = "slip",
|
.open = slip_open,
|
.close = slip_close,
|
.hangup = slip_hangup,
|
.ioctl = slip_ioctl,
|
#ifdef CONFIG_COMPAT
|
.compat_ioctl = slip_compat_ioctl,
|
#endif
|
.receive_buf = slip_receive_buf,
|
.write_wakeup = slip_write_wakeup,
|
};
|
|
static int __init slip_init(void)
|
{
|
int status;
|
|
if (slip_maxdev < 4)
|
slip_maxdev = 4; /* Sanity */
|
|
printk(KERN_INFO "SLIP: version %s (dynamic channels, max=%d)"
|
#ifdef CONFIG_SLIP_MODE_SLIP6
|
" (6 bit encapsulation enabled)"
|
#endif
|
".\n",
|
SLIP_VERSION, slip_maxdev);
|
#if defined(SL_INCLUDE_CSLIP)
|
printk(KERN_INFO "CSLIP: code copyright 1989 Regents of the University of California.\n");
|
#endif
|
#ifdef CONFIG_SLIP_SMART
|
printk(KERN_INFO "SLIP linefill/keepalive option.\n");
|
#endif
|
|
slip_devs = kcalloc(slip_maxdev, sizeof(struct net_device *),
|
GFP_KERNEL);
|
if (!slip_devs)
|
return -ENOMEM;
|
|
/* Fill in our line protocol discipline, and register it */
|
status = tty_register_ldisc(N_SLIP, &sl_ldisc);
|
if (status != 0) {
|
printk(KERN_ERR "SLIP: can't register line discipline (err = %d)\n", status);
|
kfree(slip_devs);
|
}
|
return status;
|
}
|
|
static void __exit slip_exit(void)
|
{
|
int i;
|
struct net_device *dev;
|
struct slip *sl;
|
unsigned long timeout = jiffies + HZ;
|
int busy = 0;
|
|
if (slip_devs == NULL)
|
return;
|
|
/* First of all: check for active disciplines and hangup them.
|
*/
|
do {
|
if (busy)
|
msleep_interruptible(100);
|
|
busy = 0;
|
for (i = 0; i < slip_maxdev; i++) {
|
dev = slip_devs[i];
|
if (!dev)
|
continue;
|
sl = netdev_priv(dev);
|
spin_lock_bh(&sl->lock);
|
if (sl->tty) {
|
busy++;
|
tty_hangup(sl->tty);
|
}
|
spin_unlock_bh(&sl->lock);
|
}
|
} while (busy && time_before(jiffies, timeout));
|
|
/* FIXME: hangup is async so we should wait when doing this second
|
phase */
|
|
for (i = 0; i < slip_maxdev; i++) {
|
dev = slip_devs[i];
|
if (!dev)
|
continue;
|
slip_devs[i] = NULL;
|
|
sl = netdev_priv(dev);
|
if (sl->tty) {
|
printk(KERN_ERR "%s: tty discipline still running\n",
|
dev->name);
|
}
|
|
unregister_netdev(dev);
|
}
|
|
kfree(slip_devs);
|
slip_devs = NULL;
|
|
i = tty_unregister_ldisc(N_SLIP);
|
if (i != 0)
|
printk(KERN_ERR "SLIP: can't unregister line discipline (err = %d)\n", i);
|
}
|
|
module_init(slip_init);
|
module_exit(slip_exit);
|
|
#ifdef CONFIG_SLIP_SMART
|
/*
|
* This is start of the code for multislip style line checking
|
* added by Stanislav Voronyi. All changes before marked VSV
|
*/
|
|
static void sl_outfill(struct timer_list *t)
|
{
|
struct slip *sl = from_timer(sl, t, outfill_timer);
|
|
spin_lock(&sl->lock);
|
|
if (sl->tty == NULL)
|
goto out;
|
|
if (sl->outfill) {
|
if (test_bit(SLF_OUTWAIT, &sl->flags)) {
|
/* no packets were transmitted, do outfill */
|
#ifdef CONFIG_SLIP_MODE_SLIP6
|
unsigned char s = (sl->mode & SL_MODE_SLIP6)?0x70:END;
|
#else
|
unsigned char s = END;
|
#endif
|
/* put END into tty queue. Is it right ??? */
|
if (!netif_queue_stopped(sl->dev)) {
|
/* if device busy no outfill */
|
sl->tty->ops->write(sl->tty, &s, 1);
|
}
|
} else
|
set_bit(SLF_OUTWAIT, &sl->flags);
|
|
mod_timer(&sl->outfill_timer, jiffies+sl->outfill*HZ);
|
}
|
out:
|
spin_unlock(&sl->lock);
|
}
|
|
static void sl_keepalive(struct timer_list *t)
|
{
|
struct slip *sl = from_timer(sl, t, keepalive_timer);
|
|
spin_lock(&sl->lock);
|
|
if (sl->tty == NULL)
|
goto out;
|
|
if (sl->keepalive) {
|
if (test_bit(SLF_KEEPTEST, &sl->flags)) {
|
/* keepalive still high :(, we must hangup */
|
if (sl->outfill)
|
/* outfill timer must be deleted too */
|
(void)del_timer(&sl->outfill_timer);
|
printk(KERN_DEBUG "%s: no packets received during keepalive timeout, hangup.\n", sl->dev->name);
|
/* this must hangup tty & close slip */
|
tty_hangup(sl->tty);
|
/* I think we need not something else */
|
goto out;
|
} else
|
set_bit(SLF_KEEPTEST, &sl->flags);
|
|
mod_timer(&sl->keepalive_timer, jiffies+sl->keepalive*HZ);
|
}
|
out:
|
spin_unlock(&sl->lock);
|
}
|
|
#endif
|
MODULE_LICENSE("GPL");
|
MODULE_ALIAS_LDISC(N_SLIP);
|
