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5a0e3ad6af
linux-next/drivers/net/slip.c
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00

1462 lines
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/*
* 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 <asm/system.h>
#include <asm/uaccess.h>
#include <linux/bitops.h>
#include <linux/sched.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 "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(unsigned long sls);
static void sl_outfill(unsigned long sls);
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 (slcomp == NULL)
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);
#ifdef CONFIG_SLIP_MODE_SLIP6
sl->xdata = 0;
sl->xbits = 0;
#endif
#endif
spin_unlock_bh(&sl->lock);
err = 0;
/* Cleanup */
err_exit:
#ifdef SL_INCLUDE_CSLIP
kfree(cbuff);
if (slcomp)
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;
sl->tx_dropped++;
}
}
sl->xhead = sl->xbuff;
if (sl->rcount) {
if (sl->rcount <= len) {
memcpy(sl->rbuff, rbuff, sl->rcount);
} else {
sl->rcount = 0;
sl->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 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", sl->dev->name);
return;
}
/* make sure we've reserved enough space for uncompress
to use */
if (count + 80 > sl->buffsize) {
sl->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", sl->dev->name);
}
sl->rbuff[0] &= 0x4f;
if (slhc_remember(sl->slcomp, sl->rbuff, count) <= 0)
return;
}
}
#endif /* SL_INCLUDE_CSLIP */
sl->rx_bytes += count;
skb = dev_alloc_skb(count);
if (skb == NULL) {
printk(KERN_WARNING "%s: memory squeeze, dropping packet.\n", sl->dev->name);
sl->rx_dropped++;
return;
}
skb->dev = sl->dev;
memcpy(skb_put(skb, count), sl->rbuff, count);
skb_reset_mac_header(skb);
skb->protocol = htons(ETH_P_IP);
netif_rx(skb);
sl->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->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, (unsigned char *) sl->xbuff, len);
else
#endif
count = slip_esc(p, (unsigned char *) 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
sl->dev->trans_start = jiffies;
#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
}
/*
* Called by the driver when there's room for more data. If we have
* more packets to send, we send them here.
*/
static void slip_write_wakeup(struct tty_struct *tty)
{
int actual;
struct slip *sl = tty->disc_data;
/* First make sure we're connected. */
if (!sl || sl->magic != SLIP_MAGIC || !netif_running(sl->dev))
return;
if (sl->xleft <= 0) {
/* Now serial buffer is almost free & we can start
* transmission of another packet */
sl->tx_packets++;
clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
sl_unlock(sl);
return;
}
actual = tty->ops->write(tty, sl->xhead, sl->xleft);
sl->xleft -= actual;
sl->xhead += actual;
}
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 + 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);
sl->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);
if (new_mtu < 68 || new_mtu > 65534)
return -EINVAL;
if (new_mtu != dev->mtu)
return sl_realloc_bufs(sl, new_mtu);
return 0;
}
/* Netdevice get statistics request */
static struct net_device_stats *
sl_get_stats(struct net_device *dev)
{
static struct net_device_stats stats;
struct slip *sl = netdev_priv(dev);
#ifdef SL_INCLUDE_CSLIP
struct slcompress *comp;
#endif
memset(&stats, 0, sizeof(struct net_device_stats));
stats.rx_packets = sl->rx_packets;
stats.tx_packets = sl->tx_packets;
stats.rx_bytes = sl->rx_bytes;
stats.tx_bytes = sl->tx_bytes;
stats.rx_dropped = sl->rx_dropped;
stats.tx_dropped = sl->tx_dropped;
stats.tx_errors = sl->tx_errors;
stats.rx_errors = sl->rx_errors;
stats.rx_over_errors = sl->rx_over_errors;
#ifdef SL_INCLUDE_CSLIP
stats.rx_fifo_errors = sl->rx_compressed;
stats.tx_fifo_errors = sl->tx_compressed;
stats.collisions = sl->tx_misses;
comp = sl->slcomp;
if (comp) {
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 /* CONFIG_INET */
return (&stats);
}
/* 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;
free_netdev(dev);
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_stats = sl_get_stats,
.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->destructor = sl_free_netdev;
dev->hard_header_len = 0;
dev->addr_len = 0;
dev->tx_queue_len = 10;
/* 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->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(dev_t line)
{
int i;
struct net_device *dev = NULL;
struct slip *sl;
if (slip_devs == NULL)
return NULL; /* Master array missing ! */
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;
if (dev) {
sl = netdev_priv(dev);
if (test_bit(SLF_INUSE, &sl->flags)) {
unregister_netdevice(dev);
dev = NULL;
slip_devs[i] = NULL;
}
}
if (!dev) {
char name[IFNAMSIZ];
sprintf(name, "sl%d", i);
dev = alloc_netdev(sizeof(*sl), name, 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);
sl->mode = SL_MODE_DEFAULT;
#ifdef CONFIG_SLIP_SMART
/* initialize timer_list struct */
init_timer(&sl->keepalive_timer);
sl->keepalive_timer.data = (unsigned long)sl;
sl->keepalive_timer.function = sl_keepalive;
init_timer(&sl->outfill_timer);
sl->outfill_timer.data = (unsigned long)sl;
sl->outfill_timer.function = sl_outfill;
#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(tty_devnum(tty));
if (sl == NULL)
goto err_exit;
sl->tty = tty;
tty->disc_data = sl;
sl->line = tty_devnum(tty);
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 */
return sl->dev->base_addr;
err_free_bufs:
sl_free_bufs(sl);
err_free_chan:
sl->tty = NULL;
tty->disc_data = NULL;
clear_bit(SLF_INUSE, &sl->flags);
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;
tty->disc_data = NULL;
sl->tty = NULL;
if (!sl->leased)
sl->line = 0;
/* 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->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->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 = kzalloc(sizeof(struct net_device *)*slip_maxdev,
GFP_KERNEL);
if (!slip_devs) {
printk(KERN_ERR "SLIP: Can't allocate slip devices array.\n");
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);
/* Intentionally leak the control block. */
dev->destructor = NULL;
}
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(unsigned long sls)
{
struct slip *sl = (struct slip *)sls;
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(unsigned long sls)
{
struct slip *sl = (struct slip *)sls;
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);
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