ppp: Move the PPP drivers

Move the PPP drivers into drivers/net/ppp/ and make the
necessary Kconfig and Makefile changes.

CC: Paul Mackerras <paulus@samba.org>
CC: Frank Cusack <fcusack@fcusack.com>
CC: Michal Ostrowski <mostrows@speakeasy.net>
CC: Michal Ostrowski <mostrows@earthlink.net>
CC: Dmitry Kozlov <xeb@mail.ru>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 0 insertions, 790 deletions

diff --git a/drivers/net/ppp_synctty.c b/drivers/net/ppp_synctty.c
deleted file mode 100644
index 736a39ee05bb..000000000000
--- a/drivers/net/ppp_synctty.c
+++ /dev/null
@@ -1,790 +0,0 @@
-/*
- * PPP synchronous tty channel driver for Linux.
- *
- * This is a ppp channel driver that can be used with tty device drivers
- * that are frame oriented, such as synchronous HDLC devices.
- *
- * Complete PPP frames without encoding/decoding are exchanged between
- * the channel driver and the device driver.
- *
- * The async map IOCTL codes are implemented to keep the user mode
- * applications happy if they call them. Synchronous PPP does not use
- * the async maps.
- *
- * Copyright 1999 Paul Mackerras.
- *
- * Also touched by the grubby hands of Paul Fulghum paulkf@microgate.com
- *
- *  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.
- *
- * This driver provides the encapsulation and framing for sending
- * and receiving PPP frames over sync serial lines.  It relies on
- * the generic PPP layer to give it frames to send and to process
- * received frames.  It implements the PPP line discipline.
- *
- * Part of the code in this driver was inspired by the old async-only
- * PPP driver, written by Michael Callahan and Al Longyear, and
- * subsequently hacked by Paul Mackerras.
- *
- * ==FILEVERSION 20040616==
- */
-
-#include <linux/module.h>
-#include <linux/kernel.h>
-#include <linux/skbuff.h>
-#include <linux/tty.h>
-#include <linux/netdevice.h>
-#include <linux/poll.h>
-#include <linux/ppp_defs.h>
-#include <linux/if_ppp.h>
-#include <linux/ppp_channel.h>
-#include <linux/spinlock.h>
-#include <linux/completion.h>
-#include <linux/init.h>
-#include <linux/interrupt.h>
-#include <linux/slab.h>
-#include <asm/unaligned.h>
-#include <asm/uaccess.h>
-
-#define PPP_VERSION	"2.4.2"
-
-/* Structure for storing local state. */
-struct syncppp {
-	struct tty_struct *tty;
-	unsigned int	flags;
-	unsigned int	rbits;
-	int		mru;
-	spinlock_t	xmit_lock;
-	spinlock_t	recv_lock;
-	unsigned long	xmit_flags;
-	u32		xaccm[8];
-	u32		raccm;
-	unsigned int	bytes_sent;
-	unsigned int	bytes_rcvd;
-
-	struct sk_buff	*tpkt;
-	unsigned long	last_xmit;
-
-	struct sk_buff_head rqueue;
-
-	struct tasklet_struct tsk;
-
-	atomic_t	refcnt;
-	struct completion dead_cmp;
-	struct ppp_channel chan;	/* interface to generic ppp layer */
-};
-
-/* Bit numbers in xmit_flags */
-#define XMIT_WAKEUP	0
-#define XMIT_FULL	1
-
-/* Bits in rbits */
-#define SC_RCV_BITS	(SC_RCV_B7_1|SC_RCV_B7_0|SC_RCV_ODDP|SC_RCV_EVNP)
-
-#define PPPSYNC_MAX_RQLEN	32	/* arbitrary */
-
-/*
- * Prototypes.
- */
-static struct sk_buff* ppp_sync_txmunge(struct syncppp *ap, struct sk_buff *);
-static int ppp_sync_send(struct ppp_channel *chan, struct sk_buff *skb);
-static int ppp_sync_ioctl(struct ppp_channel *chan, unsigned int cmd,
-			  unsigned long arg);
-static void ppp_sync_process(unsigned long arg);
-static int ppp_sync_push(struct syncppp *ap);
-static void ppp_sync_flush_output(struct syncppp *ap);
-static void ppp_sync_input(struct syncppp *ap, const unsigned char *buf,
-			   char *flags, int count);
-
-static const struct ppp_channel_ops sync_ops = {
-	.start_xmit = ppp_sync_send,
-	.ioctl      = ppp_sync_ioctl,
-};
-
-/*
- * Utility procedures to print a buffer in hex/ascii
- */
-static void
-ppp_print_hex (register __u8 * out, const __u8 * in, int count)
-{
-	register __u8 next_ch;
-	static const char hex[] = "0123456789ABCDEF";
-
-	while (count-- > 0) {
-		next_ch = *in++;
-		*out++ = hex[(next_ch >> 4) & 0x0F];
-		*out++ = hex[next_ch & 0x0F];
-		++out;
-	}
-}
-
-static void
-ppp_print_char (register __u8 * out, const __u8 * in, int count)
-{
-	register __u8 next_ch;
-
-	while (count-- > 0) {
-		next_ch = *in++;
-
-		if (next_ch < 0x20 || next_ch > 0x7e)
-			*out++ = '.';
-		else {
-			*out++ = next_ch;
-			if (next_ch == '%')   /* printk/syslogd has a bug !! */
-				*out++ = '%';
-		}
-	}
-	*out = '\0';
-}
-
-static void
-ppp_print_buffer (const char *name, const __u8 *buf, int count)
-{
-	__u8 line[44];
-
-	if (name != NULL)
-		printk(KERN_DEBUG "ppp_synctty: %s, count = %d\n", name, count);
-
-	while (count > 8) {
-		memset (line, 32, 44);
-		ppp_print_hex (line, buf, 8);
-		ppp_print_char (&line[8 * 3], buf, 8);
-		printk(KERN_DEBUG "%s\n", line);
-		count -= 8;
-		buf += 8;
-	}
-
-	if (count > 0) {
-		memset (line, 32, 44);
-		ppp_print_hex (line, buf, count);
-		ppp_print_char (&line[8 * 3], buf, count);
-		printk(KERN_DEBUG "%s\n", line);
-	}
-}
-
-
-/*
- * Routines implementing the synchronous PPP line discipline.
- */
-
-/*
- * We have a potential race on dereferencing tty->disc_data,
- * because the tty layer provides no locking at all - thus one
- * cpu could be running ppp_synctty_receive while another
- * calls ppp_synctty_close, which zeroes tty->disc_data and
- * frees the memory that ppp_synctty_receive is using.  The best
- * way to fix this is to use a rwlock in the tty struct, but for now
- * we use a single global rwlock for all ttys in ppp line discipline.
- *
- * FIXME: Fixed in tty_io nowadays.
- */
-static DEFINE_RWLOCK(disc_data_lock);
-
-static struct syncppp *sp_get(struct tty_struct *tty)
-{
-	struct syncppp *ap;
-
-	read_lock(&disc_data_lock);
-	ap = tty->disc_data;
-	if (ap != NULL)
-		atomic_inc(&ap->refcnt);
-	read_unlock(&disc_data_lock);
-	return ap;
-}
-
-static void sp_put(struct syncppp *ap)
-{
-	if (atomic_dec_and_test(&ap->refcnt))
-		complete(&ap->dead_cmp);
-}
-
-/*
- * Called when a tty is put into sync-PPP line discipline.
- */
-static int
-ppp_sync_open(struct tty_struct *tty)
-{
-	struct syncppp *ap;
-	int err;
-	int speed;
-
-	if (tty->ops->write == NULL)
-		return -EOPNOTSUPP;
-
-	ap = kzalloc(sizeof(*ap), GFP_KERNEL);
-	err = -ENOMEM;
-	if (!ap)
-		goto out;
-
-	/* initialize the syncppp structure */
-	ap->tty = tty;
-	ap->mru = PPP_MRU;
-	spin_lock_init(&ap->xmit_lock);
-	spin_lock_init(&ap->recv_lock);
-	ap->xaccm[0] = ~0U;
-	ap->xaccm[3] = 0x60000000U;
-	ap->raccm = ~0U;
-
-	skb_queue_head_init(&ap->rqueue);
-	tasklet_init(&ap->tsk, ppp_sync_process, (unsigned long) ap);
-
-	atomic_set(&ap->refcnt, 1);
-	init_completion(&ap->dead_cmp);
-
-	ap->chan.private = ap;
-	ap->chan.ops = &sync_ops;
-	ap->chan.mtu = PPP_MRU;
-	ap->chan.hdrlen = 2;	/* for A/C bytes */
-	speed = tty_get_baud_rate(tty);
-	ap->chan.speed = speed;
-	err = ppp_register_channel(&ap->chan);
-	if (err)
-		goto out_free;
-
-	tty->disc_data = ap;
-	tty->receive_room = 65536;
-	return 0;
-
- out_free:
-	kfree(ap);
- out:
-	return err;
-}
-
-/*
- * Called when the tty is put into another line discipline
- * or it hangs up.  We have to wait for any cpu currently
- * executing in any of the other ppp_synctty_* routines to
- * finish before we can call ppp_unregister_channel and free
- * the syncppp struct.  This routine must be called from
- * process context, not interrupt or softirq context.
- */
-static void
-ppp_sync_close(struct tty_struct *tty)
-{
-	struct syncppp *ap;
-
-	write_lock_irq(&disc_data_lock);
-	ap = tty->disc_data;
-	tty->disc_data = NULL;
-	write_unlock_irq(&disc_data_lock);
-	if (!ap)
-		return;
-
-	/*
-	 * We have now ensured that nobody can start using ap from now
-	 * on, but we have to wait for all existing users to finish.
-	 * Note that ppp_unregister_channel ensures that no calls to
-	 * our channel ops (i.e. ppp_sync_send/ioctl) are in progress
-	 * by the time it returns.
-	 */
-	if (!atomic_dec_and_test(&ap->refcnt))
-		wait_for_completion(&ap->dead_cmp);
-	tasklet_kill(&ap->tsk);
-
-	ppp_unregister_channel(&ap->chan);
-	skb_queue_purge(&ap->rqueue);
-	kfree_skb(ap->tpkt);
-	kfree(ap);
-}
-
-/*
- * Called on tty hangup in process context.
- *
- * Wait for I/O to driver to complete and unregister PPP channel.
- * This is already done by the close routine, so just call that.
- */
-static int ppp_sync_hangup(struct tty_struct *tty)
-{
-	ppp_sync_close(tty);
-	return 0;
-}
-
-/*
- * Read does nothing - no data is ever available this way.
- * Pppd reads and writes packets via /dev/ppp instead.
- */
-static ssize_t
-ppp_sync_read(struct tty_struct *tty, struct file *file,
-	       unsigned char __user *buf, size_t count)
-{
-	return -EAGAIN;
-}
-
-/*
- * Write on the tty does nothing, the packets all come in
- * from the ppp generic stuff.
- */
-static ssize_t
-ppp_sync_write(struct tty_struct *tty, struct file *file,
-		const unsigned char *buf, size_t count)
-{
-	return -EAGAIN;
-}
-
-static int
-ppp_synctty_ioctl(struct tty_struct *tty, struct file *file,
-		  unsigned int cmd, unsigned long arg)
-{
-	struct syncppp *ap = sp_get(tty);
-	int __user *p = (int __user *)arg;
-	int err, val;
-
-	if (!ap)
-		return -ENXIO;
-	err = -EFAULT;
-	switch (cmd) {
-	case PPPIOCGCHAN:
-		err = -EFAULT;
-		if (put_user(ppp_channel_index(&ap->chan), p))
-			break;
-		err = 0;
-		break;
-
-	case PPPIOCGUNIT:
-		err = -EFAULT;
-		if (put_user(ppp_unit_number(&ap->chan), p))
-			break;
-		err = 0;
-		break;
-
-	case TCFLSH:
-		/* flush our buffers and the serial port's buffer */
-		if (arg == TCIOFLUSH || arg == TCOFLUSH)
-			ppp_sync_flush_output(ap);
-		err = tty_perform_flush(tty, arg);
-		break;
-
-	case FIONREAD:
-		val = 0;
-		if (put_user(val, p))
-			break;
-		err = 0;
-		break;
-
-	default:
-		err = tty_mode_ioctl(tty, file, cmd, arg);
-		break;
-	}
-
-	sp_put(ap);
-	return err;
-}
-
-/* No kernel lock - fine */
-static unsigned int
-ppp_sync_poll(struct tty_struct *tty, struct file *file, poll_table *wait)
-{
-	return 0;
-}
-
-/* May sleep, don't call from interrupt level or with interrupts disabled */
-static void
-ppp_sync_receive(struct tty_struct *tty, const unsigned char *buf,
-		  char *cflags, int count)
-{
-	struct syncppp *ap = sp_get(tty);
-	unsigned long flags;
-
-	if (!ap)
-		return;
-	spin_lock_irqsave(&ap->recv_lock, flags);
-	ppp_sync_input(ap, buf, cflags, count);
-	spin_unlock_irqrestore(&ap->recv_lock, flags);
-	if (!skb_queue_empty(&ap->rqueue))
-		tasklet_schedule(&ap->tsk);
-	sp_put(ap);
-	tty_unthrottle(tty);
-}
-
-static void
-ppp_sync_wakeup(struct tty_struct *tty)
-{
-	struct syncppp *ap = sp_get(tty);
-
-	clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
-	if (!ap)
-		return;
-	set_bit(XMIT_WAKEUP, &ap->xmit_flags);
-	tasklet_schedule(&ap->tsk);
-	sp_put(ap);
-}
-
-
-static struct tty_ldisc_ops ppp_sync_ldisc = {
-	.owner	= THIS_MODULE,
-	.magic	= TTY_LDISC_MAGIC,
-	.name	= "pppsync",
-	.open	= ppp_sync_open,
-	.close	= ppp_sync_close,
-	.hangup	= ppp_sync_hangup,
-	.read	= ppp_sync_read,
-	.write	= ppp_sync_write,
-	.ioctl	= ppp_synctty_ioctl,
-	.poll	= ppp_sync_poll,
-	.receive_buf = ppp_sync_receive,
-	.write_wakeup = ppp_sync_wakeup,
-};
-
-static int __init
-ppp_sync_init(void)
-{
-	int err;
-
-	err = tty_register_ldisc(N_SYNC_PPP, &ppp_sync_ldisc);
-	if (err != 0)
-		printk(KERN_ERR "PPP_sync: error %d registering line disc.\n",
-		       err);
-	return err;
-}
-
-/*
- * The following routines provide the PPP channel interface.
- */
-static int
-ppp_sync_ioctl(struct ppp_channel *chan, unsigned int cmd, unsigned long arg)
-{
-	struct syncppp *ap = chan->private;
-	int err, val;
-	u32 accm[8];
-	void __user *argp = (void __user *)arg;
-	u32 __user *p = argp;
-
-	err = -EFAULT;
-	switch (cmd) {
-	case PPPIOCGFLAGS:
-		val = ap->flags | ap->rbits;
-		if (put_user(val, (int __user *) argp))
-			break;
-		err = 0;
-		break;
-	case PPPIOCSFLAGS:
-		if (get_user(val, (int __user *) argp))
-			break;
-		ap->flags = val & ~SC_RCV_BITS;
-		spin_lock_irq(&ap->recv_lock);
-		ap->rbits = val & SC_RCV_BITS;
-		spin_unlock_irq(&ap->recv_lock);
-		err = 0;
-		break;
-
-	case PPPIOCGASYNCMAP:
-		if (put_user(ap->xaccm[0], p))
-			break;
-		err = 0;
-		break;
-	case PPPIOCSASYNCMAP:
-		if (get_user(ap->xaccm[0], p))
-			break;
-		err = 0;
-		break;
-
-	case PPPIOCGRASYNCMAP:
-		if (put_user(ap->raccm, p))
-			break;
-		err = 0;
-		break;
-	case PPPIOCSRASYNCMAP:
-		if (get_user(ap->raccm, p))
-			break;
-		err = 0;
-		break;
-
-	case PPPIOCGXASYNCMAP:
-		if (copy_to_user(argp, ap->xaccm, sizeof(ap->xaccm)))
-			break;
-		err = 0;
-		break;
-	case PPPIOCSXASYNCMAP:
-		if (copy_from_user(accm, argp, sizeof(accm)))
-			break;
-		accm[2] &= ~0x40000000U;	/* can't escape 0x5e */
-		accm[3] |= 0x60000000U;		/* must escape 0x7d, 0x7e */
-		memcpy(ap->xaccm, accm, sizeof(ap->xaccm));
-		err = 0;
-		break;
-
-	case PPPIOCGMRU:
-		if (put_user(ap->mru, (int __user *) argp))
-			break;
-		err = 0;
-		break;
-	case PPPIOCSMRU:
-		if (get_user(val, (int __user *) argp))
-			break;
-		if (val < PPP_MRU)
-			val = PPP_MRU;
-		ap->mru = val;
-		err = 0;
-		break;
-
-	default:
-		err = -ENOTTY;
-	}
-	return err;
-}
-
-/*
- * This is called at softirq level to deliver received packets
- * to the ppp_generic code, and to tell the ppp_generic code
- * if we can accept more output now.
- */
-static void ppp_sync_process(unsigned long arg)
-{
-	struct syncppp *ap = (struct syncppp *) arg;
-	struct sk_buff *skb;
-
-	/* process received packets */
-	while ((skb = skb_dequeue(&ap->rqueue)) != NULL) {
-		if (skb->len == 0) {
-			/* zero length buffers indicate error */
-			ppp_input_error(&ap->chan, 0);
-			kfree_skb(skb);
-		}
-		else
-			ppp_input(&ap->chan, skb);
-	}
-
-	/* try to push more stuff out */
-	if (test_bit(XMIT_WAKEUP, &ap->xmit_flags) && ppp_sync_push(ap))
-		ppp_output_wakeup(&ap->chan);
-}
-
-/*
- * Procedures for encapsulation and framing.
- */
-
-static struct sk_buff*
-ppp_sync_txmunge(struct syncppp *ap, struct sk_buff *skb)
-{
-	int proto;
-	unsigned char *data;
-	int islcp;
-
-	data  = skb->data;
-	proto = get_unaligned_be16(data);
-
-	/* LCP packets with codes between 1 (configure-request)
-	 * and 7 (code-reject) must be sent as though no options
-	 * have been negotiated.
-	 */
-	islcp = proto == PPP_LCP && 1 <= data[2] && data[2] <= 7;
-
-	/* compress protocol field if option enabled */
-	if (data[0] == 0 && (ap->flags & SC_COMP_PROT) && !islcp)
-		skb_pull(skb,1);
-
-	/* prepend address/control fields if necessary */
-	if ((ap->flags & SC_COMP_AC) == 0 || islcp) {
-		if (skb_headroom(skb) < 2) {
-			struct sk_buff *npkt = dev_alloc_skb(skb->len + 2);
-			if (npkt == NULL) {
-				kfree_skb(skb);
-				return NULL;
-			}
-			skb_reserve(npkt,2);
-			skb_copy_from_linear_data(skb,
-				      skb_put(npkt, skb->len), skb->len);
-			kfree_skb(skb);
-			skb = npkt;
-		}
-		skb_push(skb,2);
-		skb->data[0] = PPP_ALLSTATIONS;
-		skb->data[1] = PPP_UI;
-	}
-
-	ap->last_xmit = jiffies;
-
-	if (skb && ap->flags & SC_LOG_OUTPKT)
-		ppp_print_buffer ("send buffer", skb->data, skb->len);
-
-	return skb;
-}
-
-/*
- * Transmit-side routines.
- */
-
-/*
- * Send a packet to the peer over an sync tty line.
- * Returns 1 iff the packet was accepted.
- * If the packet was not accepted, we will call ppp_output_wakeup
- * at some later time.
- */
-static int
-ppp_sync_send(struct ppp_channel *chan, struct sk_buff *skb)
-{
-	struct syncppp *ap = chan->private;
-
-	ppp_sync_push(ap);
-
-	if (test_and_set_bit(XMIT_FULL, &ap->xmit_flags))
-		return 0;	/* already full */
-	skb = ppp_sync_txmunge(ap, skb);
-	if (skb != NULL)
-		ap->tpkt = skb;
-	else
-		clear_bit(XMIT_FULL, &ap->xmit_flags);
-
-	ppp_sync_push(ap);
-	return 1;
-}
-
-/*
- * Push as much data as possible out to the tty.
- */
-static int
-ppp_sync_push(struct syncppp *ap)
-{
-	int sent, done = 0;
-	struct tty_struct *tty = ap->tty;
-	int tty_stuffed = 0;
-
-	if (!spin_trylock_bh(&ap->xmit_lock))
-		return 0;
-	for (;;) {
-		if (test_and_clear_bit(XMIT_WAKEUP, &ap->xmit_flags))
-			tty_stuffed = 0;
-		if (!tty_stuffed && ap->tpkt) {
-			set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
-			sent = tty->ops->write(tty, ap->tpkt->data, ap->tpkt->len);
-			if (sent < 0)
-				goto flush;	/* error, e.g. loss of CD */
-			if (sent < ap->tpkt->len) {
-				tty_stuffed = 1;
-			} else {
-				kfree_skb(ap->tpkt);
-				ap->tpkt = NULL;
-				clear_bit(XMIT_FULL, &ap->xmit_flags);
-				done = 1;
-			}
-			continue;
-		}
-		/* haven't made any progress */
-		spin_unlock_bh(&ap->xmit_lock);
-		if (!(test_bit(XMIT_WAKEUP, &ap->xmit_flags) ||
-		      (!tty_stuffed && ap->tpkt)))
-			break;
-		if (!spin_trylock_bh(&ap->xmit_lock))
-			break;
-	}
-	return done;
-
-flush:
-	if (ap->tpkt) {
-		kfree_skb(ap->tpkt);
-		ap->tpkt = NULL;
-		clear_bit(XMIT_FULL, &ap->xmit_flags);
-		done = 1;
-	}
-	spin_unlock_bh(&ap->xmit_lock);
-	return done;
-}
-
-/*
- * Flush output from our internal buffers.
- * Called for the TCFLSH ioctl.
- */
-static void
-ppp_sync_flush_output(struct syncppp *ap)
-{
-	int done = 0;
-
-	spin_lock_bh(&ap->xmit_lock);
-	if (ap->tpkt != NULL) {
-		kfree_skb(ap->tpkt);
-		ap->tpkt = NULL;
-		clear_bit(XMIT_FULL, &ap->xmit_flags);
-		done = 1;
-	}
-	spin_unlock_bh(&ap->xmit_lock);
-	if (done)
-		ppp_output_wakeup(&ap->chan);
-}
-
-/*
- * Receive-side routines.
- */
-
-/* called when the tty driver has data for us.
- *
- * Data is frame oriented: each call to ppp_sync_input is considered
- * a whole frame. If the 1st flag byte is non-zero then the whole
- * frame is considered to be in error and is tossed.
- */
-static void
-ppp_sync_input(struct syncppp *ap, const unsigned char *buf,
-		char *flags, int count)
-{
-	struct sk_buff *skb;
-	unsigned char *p;
-
-	if (count == 0)
-		return;
-
-	if (ap->flags & SC_LOG_INPKT)
-		ppp_print_buffer ("receive buffer", buf, count);
-
-	/* stuff the chars in the skb */
-	skb = dev_alloc_skb(ap->mru + PPP_HDRLEN + 2);
-	if (!skb) {
-		printk(KERN_ERR "PPPsync: no memory (input pkt)\n");
-		goto err;
-	}
-	/* Try to get the payload 4-byte aligned */
-	if (buf[0] != PPP_ALLSTATIONS)
-		skb_reserve(skb, 2 + (buf[0] & 1));
-
-	if (flags && *flags) {
-		/* error flag set, ignore frame */
-		goto err;
-	} else if (count > skb_tailroom(skb)) {
-		/* packet overflowed MRU */
-		goto err;
-	}
-
-	p = skb_put(skb, count);
-	memcpy(p, buf, count);
-
-	/* strip address/control field if present */
-	p = skb->data;
-	if (p[0] == PPP_ALLSTATIONS && p[1] == PPP_UI) {
-		/* chop off address/control */
-		if (skb->len < 3)
-			goto err;
-		p = skb_pull(skb, 2);
-	}
-
-	/* decompress protocol field if compressed */
-	if (p[0] & 1) {
-		/* protocol is compressed */
-		skb_push(skb, 1)[0] = 0;
-	} else if (skb->len < 2)
-		goto err;
-
-	/* queue the frame to be processed */
-	skb_queue_tail(&ap->rqueue, skb);
-	return;
-
-err:
-	/* queue zero length packet as error indication */
-	if (skb || (skb = dev_alloc_skb(0))) {
-		skb_trim(skb, 0);
-		skb_queue_tail(&ap->rqueue, skb);
-	}
-}
-
-static void __exit
-ppp_sync_cleanup(void)
-{
-	if (tty_unregister_ldisc(N_SYNC_PPP) != 0)
-		printk(KERN_ERR "failed to unregister Sync PPP line discipline\n");
-}
-
-module_init(ppp_sync_init);
-module_exit(ppp_sync_cleanup);
-MODULE_LICENSE("GPL");
-MODULE_ALIAS_LDISC(N_SYNC_PPP);