patch-2.3.19 linux/drivers/net/ppp.c

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diff -u --recursive --new-file v2.3.18/linux/drivers/net/ppp.c linux/drivers/net/ppp.c
@@ -1,3153 +0,0 @@
-/*  PPP for Linux
- *
- *  Michael Callahan <callahan@maths.ox.ac.uk>
- *  Al Longyear <longyear@netcom.com>
- *  Extensively rewritten by Paul Mackerras <paulus@cs.anu.edu.au>
- *
- *  ==FILEVERSION 990510==
- *
- *  NOTE TO MAINTAINERS:
- *     If you modify this file at all, please set the number above to the
- *     date of the modification as YYMMDD (year month day).
- *     ppp.c is shipped with a PPP distribution as well as with the kernel;
- *     if everyone increases the FILEVERSION number above, then scripts
- *     can do the right thing when deciding whether to install a new ppp.c
- *     file.  Don't change the format of that line otherwise, so the
- *     installation script can recognize it.
- */
-
-/*
-   Sources:
-
-   slip.c
-
-   RFC1331: The Point-to-Point Protocol (PPP) for the Transmission of
-   Multi-protocol Datagrams over Point-to-Point Links
-
-   RFC1332: IPCP
-
-   ppp-2.0
-
-   Flags for this module (any combination is acceptable for testing.):
-
-   OPTIMIZE_FLAG_TIME - Number of jiffies to force sending of leading flag
-			character. This is normally set to ((HZ * 3) / 2).
-			This is 1.5 seconds. If zero then the leading
-			flag is always sent.
-
-   CHECK_CHARACTERS   - Enable the checking on all received characters for
-			8 data bits, no parity. This adds a small amount of
-			processing for each received character.
-*/
-
-#define OPTIMIZE_FLAG_TIME	((HZ * 3)/2)
-#define CHECK_CHARACTERS	1
-
-#define PPP_MAX_RCV_QLEN	32	/* max # frames we queue up for pppd */
-
-/* $Id: ppp.c,v 1.24 1999/03/31 06:07:57 paulus Exp $ */
-
-#include <linux/config.h>
-#include <linux/module.h>
-#include <linux/kernel.h>
-#include <linux/sched.h>
-#include <linux/types.h>
-#include <linux/fcntl.h>
-#include <linux/interrupt.h>
-#include <linux/ptrace.h>
-#include <linux/poll.h>
-#include <linux/in.h>
-#include <linux/malloc.h>
-#include <linux/tty.h>
-#include <linux/errno.h>
-#include <linux/string.h>	/* used in new tty drivers */
-#include <linux/signal.h>	/* used in new tty drivers */
-#include <asm/system.h>
-#include <asm/bitops.h>
-#include <asm/uaccess.h>
-
-#include <linux/if.h>
-#include <linux/if_ether.h>
-#include <linux/netdevice.h>
-#include <linux/skbuff.h>
-#include <linux/inet.h>
-#include <linux/ioctl.h>
-#include <linux/ip.h>
-#include <linux/tcp.h>
-#include <linux/if_arp.h>
-#include <net/slhc_vj.h>
-
-#define fcstab	ppp_crc16_table		/* Name of the table in the kernel */
-#include <linux/ppp_defs.h>
-
-#include <linux/socket.h>
-#include <linux/if_ppp.h>
-#include <linux/if_pppvar.h>
-#include <linux/ppp-comp.h>
-
-#ifdef CONFIG_KMOD
-#include <linux/kmod.h>
-#endif
-
-/*
- * Local functions
- */
-
-#ifdef CONFIG_MODULES
-static int ppp_register_compressor (struct compressor *cp);
-static void ppp_unregister_compressor (struct compressor *cp);
-#endif
-
-static void ppp_async_init(struct ppp *ppp);
-static void ppp_async_release(struct ppp *ppp);
-static int ppp_tty_sync_push(struct ppp *ppp);
-static int ppp_tty_push(struct ppp *ppp);
-static int ppp_async_encode(struct ppp *ppp);
-static int ppp_async_send(struct ppp *, struct sk_buff *);
-static int ppp_sync_send(struct ppp *, struct sk_buff *);
-static void ppp_tty_flush_output(struct ppp *);
-
-static int ppp_ioctl(struct ppp *, unsigned int, unsigned long);
-static int ppp_set_compression (struct ppp *ppp, struct ppp_option_data *odp);
-static void ppp_proto_ccp(struct ppp *ppp, __u8 *dp, int len, int rcvd);
-static void ppp_ccp_closed(struct ppp *ppp);
-static int ppp_receive_frame(struct ppp *, struct sk_buff *);
-static void ppp_receive_error(struct ppp *ppp);
-static void ppp_output_wakeup(struct ppp *ppp);
-static void ppp_send_ctrl(struct ppp *ppp, struct sk_buff *skb);
-static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
-static void ppp_send_frames(struct ppp *ppp);
-static struct sk_buff *ppp_vj_compress(struct ppp *ppp, struct sk_buff *skb);
-
-static struct ppp *ppp_find (int pid_value);
-static struct ppp *ppp_alloc (void);
-static void ppp_generic_init(struct ppp *ppp);
-static void ppp_release(struct ppp *ppp);
-static void ppp_print_buffer (const char *, const __u8 *, int);
-static struct compressor *find_compressor (int type);
-
-#ifndef OPTIMIZE_FLAG_TIME
-#define OPTIMIZE_FLAG_TIME	0
-#endif
-
-/*
- * Parameters which may be changed via insmod.
- */
-
-static int  flag_time = OPTIMIZE_FLAG_TIME;
-MODULE_PARM(flag_time, "i");
-
-#define CHECK_PPP_MAGIC(ppp)	do { \
-	if (ppp->magic != PPP_MAGIC) { \
-		printk(ppp_magic_warn, ppp, __FILE__, __LINE__); \
-	} \
-} while (0)
-#define CHECK_PPP(a)	do { \
-	CHECK_PPP_MAGIC(ppp); \
-	if (!ppp->inuse) { \
-		printk(ppp_warning, __LINE__); \
-		return a; \
-	} \
-} while (0)
-#define CHECK_PPP_VOID() do { \
-	CHECK_PPP_MAGIC(ppp); \
-	if (!ppp->inuse) { \
-		printk(ppp_warning, __LINE__); \
-		return; \
-	} \
-} while (0)
-
-#define tty2ppp(tty)	((struct ppp *) ((tty)->disc_data))
-#define dev2ppp(dev)	((struct ppp *) ((dev)->priv))
-#define ppp2tty(ppp)	((ppp)->tty)
-#define ppp2dev(ppp)	(&(ppp)->dev)
-
-static struct ppp *ppp_list = NULL;
-static struct ppp *ppp_last = NULL;
-
-/* Define these strings only once for all macro invocations */
-static char ppp_warning[] = KERN_WARNING "PPP: ALERT! not INUSE! %d\n";
-static char ppp_magic_warn[] = KERN_WARNING "bad magic for ppp %p at %s:%d\n";
-
-static char szVersion[]		= PPP_VERSION;
-
-EXPORT_SYMBOL(ppp_register_compressor);
-EXPORT_SYMBOL(ppp_unregister_compressor);
-
-/*************************************************************
- * LINE DISCIPLINE SUPPORT
- *    The following code implements the PPP line discipline
- *    and supports using PPP on an async serial line.
- *************************************************************/
-
-#define in_xmap(ppp,c)	(ppp->xmit_async_map[(c) >> 5] & (1 << ((c) & 0x1f)))
-#define in_rmap(ppp,c)	((((unsigned int) (__u8) (c)) < 0x20) && \
-			ppp->recv_async_map & (1 << (c)))
-
-/*
- * TTY callbacks
- */
-
-static ssize_t ppp_tty_read(struct tty_struct *, struct file *, __u8 *,
-			    size_t);
-static ssize_t ppp_tty_write(struct tty_struct *, struct file *, const __u8 *,
-			     size_t);
-static int ppp_tty_ioctl(struct tty_struct *, struct file *, unsigned int,
-			 unsigned long);
-static unsigned int ppp_tty_poll(struct tty_struct *tty, struct file *filp,
-				 poll_table * wait);
-static int ppp_tty_open (struct tty_struct *);
-static void ppp_tty_close (struct tty_struct *);
-static int ppp_tty_room (struct tty_struct *tty);
-static void ppp_tty_receive (struct tty_struct *tty, const __u8 * cp,
-			     char *fp, int count);
-static void ppp_tty_wakeup (struct tty_struct *tty);
-
-__u16 ppp_crc16_table[256] =
-{
-	0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
-	0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
-	0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
-	0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
-	0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
-	0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
-	0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
-	0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
-	0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
-	0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
-	0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
-	0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
-	0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
-	0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
-	0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
-	0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
-	0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
-	0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
-	0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
-	0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
-	0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
-	0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
-	0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
-	0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
-	0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
-	0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
-	0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
-	0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
-	0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
-	0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
-	0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
-	0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
-};
-EXPORT_SYMBOL(ppp_crc16_table);
-
-#ifdef CHECK_CHARACTERS
-static __u32 paritytab[8] =
-{
-	0x96696996, 0x69969669, 0x69969669, 0x96696996,
-	0x69969669, 0x96696996, 0x96696996, 0x69969669
-};
-#endif
-
-/*
- * This procedure is called at initialization time to register
- * the PPP line discipline.
- */
-static int
-ppp_first_time(void)
-{
-	static struct tty_ldisc	ppp_ldisc;
-	int    status;
-
-	printk(KERN_INFO
-	       "PPP: version %s (demand dialling)"
-	       "\n", szVersion);
-
-#ifndef MODULE /* slhc module logic has its own copyright announcement */
-	printk(KERN_INFO
-	       "TCP compression code copyright 1989 Regents of the "
-	       "University of California\n");
-#endif
-
-	/*
-	 * Register the tty discipline
-	 */
-	(void) memset (&ppp_ldisc, 0, sizeof (ppp_ldisc));
-	ppp_ldisc.magic		= TTY_LDISC_MAGIC;
-	ppp_ldisc.name          = "ppp";
-	ppp_ldisc.open		= ppp_tty_open;
-	ppp_ldisc.close		= ppp_tty_close;
-	ppp_ldisc.read		= ppp_tty_read;
-	ppp_ldisc.write		= ppp_tty_write;
-	ppp_ldisc.ioctl		= ppp_tty_ioctl;
-	ppp_ldisc.poll		= ppp_tty_poll;
-	ppp_ldisc.receive_room	= ppp_tty_room;
-	ppp_ldisc.receive_buf	= ppp_tty_receive;
-	ppp_ldisc.write_wakeup	= ppp_tty_wakeup;
-
-	status = tty_register_ldisc (N_PPP, &ppp_ldisc);
-	if (status == 0)
-		printk(KERN_INFO "PPP line discipline registered.\n");
-	else
-		printk(KERN_ERR "error registering line discipline: %d\n",
-		       status);
-	return status;
-}
-
-
-#ifndef MODULE
-/*
- * Called at boot time if the PPP driver is compiled into the kernel.
- */
-int
-ppp_init(struct net_device *dev)
-{
-	static int first_time = 1;
-	int    answer = 0;
-
-	if (first_time) {
-		first_time = 0;
-		answer	   = ppp_first_time();
-	}
-	if (answer == 0)
-		answer = -ENODEV;
-	return answer;
-}
-#endif
-
-/*
- * Initialize the async-specific parts of the ppp structure.
- */
-static void
-ppp_async_init(struct ppp *ppp)
-{
-	ppp->escape = 0;
-	ppp->toss   = 0xE0;
-	ppp->tty_pushing = 0;
-
-	memset (ppp->xmit_async_map, 0, sizeof (ppp->xmit_async_map));
-	ppp->xmit_async_map[0] = 0xffffffff;
-	ppp->xmit_async_map[3] = 0x60000000;
-	ppp->recv_async_map    = 0xffffffff;
-
-	ppp->tpkt = NULL;
-	ppp->tfcs = PPP_INITFCS;
-	ppp->optr = ppp->obuf;
-	ppp->olim = ppp->obuf;
-
-	ppp->rpkt = NULL;
-	ppp->rfcs = PPP_INITFCS;
-
-	ppp->tty  = NULL;
-	ppp->backup_tty = NULL;
-
-	ppp->bytes_sent = 0;
-	ppp->bytes_rcvd = 0;
-}
-
-/*
- * Clean up the async-specific parts of the ppp structure.
- */
-static void
-ppp_async_release(struct ppp *ppp)
-{
-	struct sk_buff *skb;
-
-	if ((skb = ppp->rpkt) != NULL)
-		kfree_skb(skb);
-	ppp->rpkt = NULL;
-	if ((skb = ppp->tpkt) != NULL)
-		kfree_skb(skb);
-	ppp->tpkt = NULL;
-}
-
-/*
- * TTY callback.
- *
- * Called when the tty discipline is switched to PPP.
- */
-
-static int
-ppp_tty_open (struct tty_struct *tty)
-{
-	struct ppp *ppp;
-
-	/*
-	 * Allocate a ppp structure to use.
-	 */
-	tty->disc_data = NULL;
-	ppp = ppp_find(current->pid);
-	if (ppp != NULL) {
-		/*
-		 * If we are taking over a ppp unit which is currently
-		 * connected to a loopback pty, there's not much to do.
-		 */
-		CHECK_PPP(-EINVAL);
-
-	} else {
-		ppp = ppp_alloc();
-		if (ppp == NULL) {
-			printk(KERN_ERR "ppp_alloc failed\n");
-			return -ENFILE;
-		}
-
-		/*
-		 * Initialize the control block
-		 */
-		ppp_generic_init(ppp);
-		ppp_async_init(ppp);
-
-		MOD_INC_USE_COUNT;
-	}
-
-	tty->disc_data = ppp;
-	ppp->tty       = tty;
-
-	/*
-	 * Flush any pending characters in the driver
-	 */
-	if (tty->driver.flush_buffer)
-		tty->driver.flush_buffer (tty);
-
-	return ppp->line;
-}
-
-/*
- * TTY callback.
- *
- * Called when the line discipline is changed to something
- * else, the tty is closed, or the tty detects a hangup.
- */
-
-static void
-ppp_tty_close (struct tty_struct *tty)
-{
-	struct ppp *ppp = tty2ppp(tty);
-
-	if (ppp == NULL)
-		return;
-	tty->disc_data = NULL;
-	if (ppp->magic != PPP_MAGIC) {
-		printk(KERN_WARNING "ppp_tty_close: bogus\n");
-		return;
-	}
-	if (!ppp->inuse) {
-		printk(KERN_WARNING "ppp_tty_close: not inuse\n");
-		ppp->tty = ppp->backup_tty = 0;
-		return;
-	}
-	if (tty == ppp->backup_tty)
-		ppp->backup_tty = 0;
-	if (tty != ppp->tty)
-		return;
-	if (ppp->backup_tty) {
-		ppp->tty = ppp->backup_tty;
-		if (ppp_tty_push(ppp))
-			ppp_output_wakeup(ppp);
-		wake_up_interruptible(&ppp->read_wait);
-	} else {
-		ppp->tty = 0;
-		ppp->sc_xfer = 0;
-		if (ppp->flags & SC_DEBUG)
-			printk(KERN_INFO "ppp: channel %s closing.\n",
-			       ppp2dev(ppp)->name);
-
-		ppp_async_release(ppp);
-		ppp_release(ppp);
-		MOD_DEC_USE_COUNT;
-	}
-}
-
-/*
- * Read a PPP frame from the rcv_q list,
- * waiting if necessary
- */
-static ssize_t
-ppp_tty_read(struct tty_struct *tty, struct file *file, __u8 * buf,
-	     size_t nr)
-{
-	struct ppp *ppp = tty2ppp (tty);
-	struct sk_buff *skb;
-	ssize_t len, err;
-
-	/*
-	 * Validate the pointers
-	 */
-	if (!ppp)
-		return -EIO;
-	CHECK_PPP(-ENXIO);
-
-	/*
-	 * Before we attempt to write the frame to the user, ensure that the
-	 * user has access to the pages for the total buffer length.
-	 */
-	err = verify_area(VERIFY_WRITE, buf, nr);
-	if (err != 0)
-		return (err);
-
-	/*
-	 * Wait for a frame to arrive if necessary.
-	 * We increment the module use count so that the module
-	 * can't go away while we're sleeping.
-	 */
-	MOD_INC_USE_COUNT;
-	skb = NULL;
-	for (;;) {
-		ppp = tty2ppp(tty);
-		err = 0;
-		if (!ppp || ppp->magic != PPP_MAGIC || !ppp->inuse
-		    || tty != ppp->tty)
-			break;
-
-		skb = skb_dequeue(&ppp->rcv_q);
-		if (skb != 0)
-			break;
-
-		/*
-		 * If no frame is available, return -EAGAIN or wait.
-		 */
-		err = -EAGAIN;
-		if (file->f_flags & O_NONBLOCK)
-			break;
-
-		interruptible_sleep_on(&ppp->read_wait);
-		err = -EINTR;
-		if (signal_pending(current))
-			break;
-	}
-	MOD_DEC_USE_COUNT;
-	if (skb == 0)
-		return err;
-
-	/*
-	 * Ensure that the frame will fit within the caller's buffer.
-	 * If not, just discard the frame.
-	 */
-	len = skb->len;
-	if (len > nr) {
-		if (ppp->flags & SC_DEBUG)
-			printk(KERN_DEBUG
-			       "ppp: read of %lu bytes too small for %ld "
-			       "frame\n", (unsigned long) nr, (long) len);
-		ppp->stats.ppp_ierrors++;
-		err = -EOVERFLOW;
-		goto out;
-	}
-
-	/*
-	 * Copy the received data from the buffer to the caller's area.
-	 */
-	err = len;
-	if (copy_to_user(buf, skb->data, len))
-		err = -EFAULT;
-
-out:
-	kfree_skb(skb);
-	return err;
-}
-
-/*
- * Writing to a tty in ppp line discipline sends a PPP frame.
- * Used by pppd to send control packets (LCP, etc.).
- */
-static ssize_t
-ppp_tty_write(struct tty_struct *tty, struct file *file, const __u8 * data,
-	      size_t count)
-{
-	struct ppp *ppp = tty2ppp (tty);
-	__u8 *new_data;
-	struct sk_buff *skb;
-
-	/*
-	 * Verify the pointers.
-	 */
-	if (!ppp)
-		return -EIO;
-
-	if (ppp->magic != PPP_MAGIC)
-		return -EIO;
-
-	CHECK_PPP(-ENXIO);
-
-	/*
-	 * Ensure that the caller does not wish to send too much.
-	 */
-	if (count > PPP_MTU + PPP_HDRLEN) {
-		if (ppp->flags & SC_DEBUG)
-			printk(KERN_WARNING
-			       "ppp_tty_write: truncating user packet "
-			       "from %lu to mtu %d\n", (unsigned long) count,
-			       PPP_MTU + PPP_HDRLEN);
-		count = PPP_MTU + PPP_HDRLEN;
-	}
-
-	/*
-	 * Allocate a buffer for the data and fetch it from the user space.
-	 */
-	skb = alloc_skb(count, GFP_KERNEL);
-	if (skb == NULL) {
-		printk(KERN_ERR "ppp_tty_write: no memory\n");
-		return 0;
-	}
-	new_data = skb_put(skb, count);
-
-	/*
-	 * Retrieve the user's buffer
-	 */
-	if (copy_from_user(new_data, data, count)) {
-		kfree_skb(skb);
-		return -EFAULT;
-	}
-
-	/*
-	 * Send the frame
-	 */
-	ppp_send_ctrl(ppp, skb);
-
-	return (ssize_t) count;
-}
-
-/*
- * Process the IOCTL call for the tty device.
- * Only the ioctls that relate to using ppp on async serial lines
- * are processed here; the rest are handled by ppp_ioctl.
- */
-static int
-ppp_tty_ioctl (struct tty_struct *tty, struct file * file,
-               unsigned int param2, unsigned long param3)
-{
-	struct ppp *ppp = tty2ppp (tty);
-	register int temp_i = 0;
-	int error = -EFAULT;
-
-	/*
-	 * Verify the status of the PPP device.
-	 */
-	if (!ppp || ppp->magic != PPP_MAGIC || !ppp->inuse)
-		return -ENXIO;
-
-	/*
-	 * The user must have an euid of root to do these requests.
-	 */
-	if (!capable(CAP_NET_ADMIN))
-		return -EPERM;
-
-	switch (param2) {
-	case PPPIOCGASYNCMAP:
-		/*
-		 * Retrieve the transmit async map
-		 */
-		if (put_user(ppp->xmit_async_map[0], (int *) param3))
-			break;
-		error = 0;
-		break;
-
-	case PPPIOCSASYNCMAP:
-		/*
-		 * Set the transmit async map
-		 */
-		if (get_user(temp_i, (int *) param3))
-			break;
-		ppp->xmit_async_map[0] = temp_i;
-		if (ppp->flags & SC_DEBUG)
-			printk(KERN_INFO
-			       "ppp_tty_ioctl: set xmit asyncmap %x\n",
-			       ppp->xmit_async_map[0]);
-		error = 0;
-		break;
-
-	case PPPIOCSRASYNCMAP:
-		/*
-		 * Set the receive async map
-		 */
-		if (get_user(temp_i, (int *) param3))
-			break;
-		ppp->recv_async_map = temp_i;
-		if (ppp->flags & SC_DEBUG)
-			printk(KERN_INFO
-			       "ppp_tty_ioctl: set rcv asyncmap %x\n",
-			       ppp->recv_async_map);
-		error = 0;
-		break;
-
-	case PPPIOCGXASYNCMAP:
-		/*
-		 * Get the map of characters to be escaped on transmission.
-		 */
-		if (copy_to_user((void *) param3, ppp->xmit_async_map,
-				 sizeof (ppp->xmit_async_map)))
-			break;
-		error = 0;
-		break;
-
-	case PPPIOCSXASYNCMAP:
-		/*
-		 * Set the map of characters to be escaped on transmission.
-		 */
-		{
-			__u32 temp_tbl[8];
-
-			if (copy_from_user(temp_tbl, (void *) param3,
-					   sizeof (temp_tbl)))
-				break;
-
-			temp_tbl[1]  =	0x00000000;
-			temp_tbl[2] &= ~0x40000000;
-			temp_tbl[3] |=	0x60000000;
-
-			memcpy(ppp->xmit_async_map, temp_tbl,
-			       sizeof (ppp->xmit_async_map));
-
-			if (ppp->flags & SC_DEBUG)
-				printk(KERN_INFO
-				       "ppp_tty_ioctl: set xasyncmap\n");
-			error = 0;
-		}
-		break;
-
-	case PPPIOCXFERUNIT:
-		/*
-		 * Set up this PPP unit to be used next time this
-		 * process sets a tty to PPP line discipline.
-		 */
-		ppp->backup_tty = tty;
-		ppp->sc_xfer = current->pid;
-		error = 0;
-		break;
-
-	case TCGETS:
-	case TCGETA:
-		/*
-		 * Allow users to read, but not set, the serial port parameters
-		 */
-		error = n_tty_ioctl (tty, file, param2, param3);
-		break;
-
-	case TCFLSH:
-		/*
-		 * Flush our buffers, then call the generic code to
-		 * flush the serial port's buffer.
-		 */
-		if (param3 == TCIFLUSH || param3 == TCIOFLUSH) {
-			struct sk_buff *skb;
-			while ((skb = skb_dequeue(&ppp->rcv_q)) != NULL)
-				kfree_skb(skb);
-		}
-		if (param3 == TCIOFLUSH || param3 == TCOFLUSH)
-			ppp_tty_flush_output(ppp);
-		error = n_tty_ioctl (tty, file, param2, param3);
-		break;
-
-	case FIONREAD:
-		/*
-		 * Returns how many bytes are available for a read().
-		 */
-		{
-			unsigned long flags;
-			struct sk_buff *skb;
-			int count = 0;
-
-			save_flags(flags);
-			cli();
-			skb = skb_peek(&ppp->rcv_q);
-			if (skb != 0)
-				count = skb->len;
-			restore_flags(flags);
-			if (put_user(count, (int *) param3))
-				break;
-			error = 0;
-		}
-		break;
-
-	default:
-		/*
-		 *  All other ioctl() events will come here.
-		 */
-		error = ppp_ioctl(ppp, param2, param3);
-		break;
-	}
-	return error;
-}
-
-/*
- * TTY callback.
- *
- * Process the poll() statement for the PPP device.
- */
-
-static unsigned int
-ppp_tty_poll(struct tty_struct *tty, struct file *filp, poll_table * wait)
-{
-	struct ppp *ppp = tty2ppp(tty);
-	unsigned int mask = 0;
-
-	if (ppp && ppp->magic == PPP_MAGIC && tty == ppp->tty) {
-		CHECK_PPP(0);
-
-		poll_wait(filp, &ppp->read_wait, wait);
-
-		if (skb_peek(&ppp->rcv_q) != NULL)
-			mask |= POLLIN | POLLRDNORM;
-		if (tty->flags & (1 << TTY_OTHER_CLOSED)
-		    || tty_hung_up_p(filp))
-			mask |= POLLHUP;
-		mask |= POLLOUT | POLLWRNORM;
-	}
-	return mask;
-}
-
-/*
- * This function is called by the tty driver when the transmit buffer has
- * additional space. It is used by the ppp code to continue to transmit
- * the current buffer should the buffer have been partially sent.
- */
-static void
-ppp_tty_wakeup (struct tty_struct *tty)
-{
-	struct ppp *ppp = tty2ppp (tty);
-
-	tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP);
-	if (!ppp)
-		return;
-	CHECK_PPP_VOID();
-	if (tty != ppp->tty)
-		return;
-
-	if (ppp_tty_push(ppp))
-		ppp_output_wakeup(ppp);
-}
-
-/*
- * Send a packet to the peer over a synchronous tty line.
- * All encoding and FCS are handled by hardware.
- * Addr/Ctrl and Protocol field compression implemented.
- * Returns -1 iff the packet could not be accepted at present,
- * 0 if the packet was accepted but we can't accept another yet, or
- * 1 if we can accept another packet immediately.
- * If this procedure returns 0, ppp_output_wakeup will be called
- * exactly once.
- */
-static int
-ppp_sync_send(struct ppp *ppp, struct sk_buff *skb)
-{
-	unsigned char *data;
-	int islcp;
-	
-	CHECK_PPP(0);
-
-	if (ppp->tpkt != NULL)
-		return -1;
-	ppp->tpkt = skb;
-
-	data = ppp->tpkt->data;
-	
-	/*
-	 * LCP packets with code values between 1 (configure-reqest)
-	 * and 7 (code-reject) must be sent as though no options
-	 * had been negotiated.
-	 */
-	islcp = PPP_PROTOCOL(data) == PPP_LCP
-		&& 1 <= data[PPP_HDRLEN] && data[PPP_HDRLEN] <= 7;
-
-	/* only reset idle time for data packets */
-	if (PPP_PROTOCOL(data) < 0x8000)
-		ppp->last_xmit = jiffies;
-	++ppp->stats.ppp_opackets;
-	ppp->stats.ppp_ooctects += ppp->tpkt->len;
-
-	if ( !(data[2]) && (ppp->flags & SC_COMP_PROT) ) {
-		/* compress protocol field */
-		data[2] = data[1];
-		data[1] = data[0];
-		skb_pull(ppp->tpkt,1);
-		data = ppp->tpkt->data;
-	}
-	
-	/*
-	 * Do address/control compression
-	 */
-	if ((ppp->flags & SC_COMP_AC) && !islcp
-	    && PPP_ADDRESS(data) == PPP_ALLSTATIONS
-	    && PPP_CONTROL(data) == PPP_UI) {
-		/* strip addr and control field */
-		skb_pull(ppp->tpkt,2);
-	}
-
-	return ppp_tty_sync_push(ppp);
-}
-
-/*
- * Push a synchronous frame out to the tty.
- * Returns 1 if frame accepted (or discarded), 0 otherwise.
- */
-static int
-ppp_tty_sync_push(struct ppp *ppp)
-{
-	int sent;
-	struct tty_struct *tty = ppp2tty(ppp);
-	unsigned long flags;
-		
-	CHECK_PPP(0);
-
-	if (ppp->tpkt == NULL)
-		return 0;
-		
-	/* prevent reentrancy with tty_pushing flag */		
-	save_flags(flags);
-	cli();
-	if (ppp->tty_pushing) {
-		/* record wakeup attempt so we don't lose */
-		/* a wakeup call while doing push processing */
-		ppp->woke_up=1;
-		restore_flags(flags);
-		return 0;
-	}
-	ppp->tty_pushing = 1;
-	restore_flags(flags);
-	
-	if (tty == NULL || tty->disc_data != (void *) ppp)
-		goto flush;
-		
-	for(;;){
-		ppp->woke_up=0;
-		
-		/* Note: Sync driver accepts complete frame or nothing */
-		tty->flags |= (1 << TTY_DO_WRITE_WAKEUP);
-		sent = tty->driver.write(tty, 0, ppp->tpkt->data, ppp->tpkt->len);
-		if (sent < 0) {
-			/* write error (possible loss of CD) */
-			/* record error and discard current packet */
-			ppp->stats.ppp_oerrors++;
-			break;
-		}
-		ppp->stats.ppp_obytes += sent;
-		if (sent < ppp->tpkt->len) {
-			/* driver unable to accept frame just yet */
-			save_flags(flags);
-			cli();
-			if (ppp->woke_up) {
-				/* wake up called while processing */
-				/* try to send the frame again */
-				restore_flags(flags);
-				continue;
-			}
-			/* wait for wakeup callback to try send again */
-			ppp->tty_pushing = 0;
-			restore_flags(flags);
-			return 0;
-		}
-		break;
-	}
-flush:	
-	/* done with current packet (sent or discarded) */
-	kfree_skb(ppp->tpkt);
-	ppp->tpkt = 0;
-	ppp->tty_pushing = 0;
-	return 1;
-}
-
-/*
- * Send a packet to the peer over an async tty line.
- * Returns -1 iff the packet could not be accepted at present,
- * 0 if the packet was accepted but we can't accept another yet, or
- * 1 if we can accept another packet immediately.
- * If this procedure returns 0, ppp_output_wakeup will be called
- * exactly once.
- */
-static int
-ppp_async_send(struct ppp *ppp, struct sk_buff *skb)
-{
-	CHECK_PPP(0);
-
-	ppp_tty_push(ppp);
-
-	if (ppp->tpkt != NULL)
-		return -1;
-	ppp->tpkt = skb;
-	ppp->tpkt_pos = 0;
-
-	return ppp_tty_push(ppp);
-}
-
-/*
- * Push as much data as possible out to the tty.
- * Returns 1 if we finished encoding the current frame, 0 otherwise.
- */
-static int
-ppp_tty_push(struct ppp *ppp)
-{
-	int avail, sent, done = 0;
-	struct tty_struct *tty = ppp2tty(ppp);
-	
-	if (ppp->flags & SC_SYNC) 
-		return ppp_tty_sync_push(ppp);
-
-	CHECK_PPP(0);
-	if (ppp->tty_pushing) {
-		ppp->woke_up = 1;
-		return 0;
-	}
-	if (tty == NULL || tty->disc_data != (void *) ppp)
-		goto flush;
-	while (ppp->optr < ppp->olim || ppp->tpkt != 0) {
-		ppp->tty_pushing = 1;
-		mb();
-		ppp->woke_up = 0;
-		avail = ppp->olim - ppp->optr;
-		if (avail > 0) {
-			tty->flags |= (1 << TTY_DO_WRITE_WAKEUP);
-			sent = tty->driver.write(tty, 0, ppp->optr, avail);
-			if (sent < 0)
-				goto flush;	/* error, e.g. loss of CD */
-			ppp->stats.ppp_obytes += sent;
-			ppp->optr += sent;
-			if (sent < avail) {
-				wmb();
-				ppp->tty_pushing = 0;
-				mb();
-				if (ppp->woke_up)
-					continue;
-				return done;
-			}
-		}
-		if (ppp->tpkt != 0)
-			done = ppp_async_encode(ppp);
-		wmb();
-		ppp->tty_pushing = 0;
-	}
-	return done;
-
-flush:
-	ppp->tty_pushing = 1;
-	mb();
-	ppp->stats.ppp_oerrors++;
-	if (ppp->tpkt != 0) {
-		kfree_skb(ppp->tpkt);
-		ppp->tpkt = 0;
-		done = 1;
-	}
-	ppp->optr = ppp->olim;
-	wmb();
-	ppp->tty_pushing = 0;
-	return done;
-}
-
-/*
- * Procedure to encode the data for async serial transmission.
- * Does octet stuffing (escaping) and address/control
- * and protocol compression.
- * Assumes ppp->opkt != 0 on entry.
- * Returns 1 if we finished the current frame, 0 otherwise.
- */
-static int
-ppp_async_encode(struct ppp *ppp)
-{
-	int fcs, i, count, c;
-	unsigned char *buf, *buflim;
-	unsigned char *data;
-	int islcp;
-
-	CHECK_PPP(0);
-
-	buf = ppp->obuf;
-	ppp->olim = buf;
-	ppp->optr = buf;
-	i = ppp->tpkt_pos;
-	data = ppp->tpkt->data;
-	count = ppp->tpkt->len;
-	fcs = ppp->tfcs;
-
-	/*
-	 * LCP packets with code values between 1 (configure-reqest)
-	 * and 7 (code-reject) must be sent as though no options
-	 * had been negotiated.
-	 */
-	islcp = PPP_PROTOCOL(data) == PPP_LCP
-		&& 1 <= data[PPP_HDRLEN] && data[PPP_HDRLEN] <= 7;
-
-	if (i == 0) {
-		/*
-		 * Start of a new packet - insert the leading FLAG
-		 * character if necessary.
-		 */
-		if (islcp || flag_time == 0
-		    || jiffies - ppp->last_xmit >= flag_time)
-			*buf++ = PPP_FLAG;
-		/* only reset idle time for data packets */
-		if (PPP_PROTOCOL(data) < 0x8000)
-			ppp->last_xmit = jiffies;
-		fcs = PPP_INITFCS;
-		++ppp->stats.ppp_opackets;
-		ppp->stats.ppp_ooctects += count;
-
-		/*
-		 * Do address/control compression
-		 */
-		if ((ppp->flags & SC_COMP_AC) != 0 && !islcp
-		    && PPP_ADDRESS(data) == PPP_ALLSTATIONS
-		    && PPP_CONTROL(data) == PPP_UI)
-			i += 2;
-	}
-
-	/*
-	 * Once we put in the last byte, we need to put in the FCS
-	 * and closing flag, so make sure there is at least 7 bytes
-	 * of free space in the output buffer.
-	 */
-	buflim = buf + OBUFSIZE - 6;
-	while (i < count && buf < buflim) {
-		c = data[i++];
-		if (i == 3 && c == 0 && (ppp->flags & SC_COMP_PROT))
-			continue;	/* compress protocol field */
-		fcs = PPP_FCS(fcs, c);
-		if (in_xmap(ppp, c) || (islcp && c < 0x20)) {
-			*buf++ = PPP_ESCAPE;
-			c ^= 0x20;
-		}
-		*buf++ = c;
-	}
-
-	if (i == count) {
-		/*
-		 * We have finished the packet.  Add the FCS and flag.
-		 */
-		fcs = ~fcs;
-		c = fcs & 0xff;
-		if (in_xmap(ppp, c) || (islcp && c < 0x20)) {
-			*buf++ = PPP_ESCAPE;
-			c ^= 0x20;
-		}
-		*buf++ = c;
-		c = (fcs >> 8) & 0xff;
-		if (in_xmap(ppp, c) || (islcp && c < 0x20)) {
-			*buf++ = PPP_ESCAPE;
-			c ^= 0x20;
-		}
-		*buf++ = c;
-		*buf++ = PPP_FLAG;
-		ppp->olim = buf;
-
-		kfree_skb(ppp->tpkt);
-		ppp->tpkt = 0;
-		return 1;
-	}
-
-	/*
-	 * Remember where we are up to in this packet.
-	 */
-	ppp->olim = buf;
-	ppp->tpkt_pos = i;
-	ppp->tfcs = fcs;
-	return 0;
-}
-
-/*
- * Flush output from our internal buffers.
- * Called for the TCFLSH ioctl.
- */
-static void
-ppp_tty_flush_output(struct ppp *ppp)
-{
-	struct sk_buff *skb;
-	int done = 0;
-
-	while ((skb = skb_dequeue(&ppp->xmt_q)) != NULL)
-		kfree_skb(skb);
-	ppp->tty_pushing = 1;
-	mb();
-	ppp->optr = ppp->olim;
-	if (ppp->tpkt != NULL) {
-		kfree_skb(ppp->tpkt);
-		ppp->tpkt = 0;
-		done = 1;
-	}
-	wmb();
-	ppp->tty_pushing = 0;
-	if (done)
-		ppp_output_wakeup(ppp);
-}
-
-/*
- * Callback function from tty driver. Return the amount of space left
- * in the receiver's buffer to decide if remote transmitter is to be
- * throttled.
- */
-static int
-ppp_tty_room (struct tty_struct *tty)
-{
-	return 65536;	    /* We can handle an infinite amount of data. :-) */
-}
-
-/*
- * Callback function when data is available at the tty driver.
- */
-static void
-ppp_tty_receive (struct tty_struct *tty, const __u8 * data,
-		 char *flags, int count)
-{
-	register struct ppp *ppp = tty2ppp (tty);
-	struct sk_buff *skb;
-	int chr, flg;
-	unsigned char *p;
-
-	if (ppp != 0)
-		CHECK_PPP_VOID();
-	/*
-	 * This can happen if stuff comes in on the backup tty.
-	 */
-	if (ppp == 0 || tty != ppp->tty)
-		return;
-	/*
-	 * Verify the table pointer and ensure that the line is
-	 * still in PPP discipline.
-	 */
-	if (ppp->magic != PPP_MAGIC) {
-		if (ppp->flags & SC_DEBUG)
-			printk(KERN_DEBUG
-			       "PPP: tty_receive called but couldn't find "
-			       "PPP struct.\n");
-		return;
-	}
-	/*
-	 * Print the buffer if desired
-	 */
-	if (ppp->flags & SC_LOG_RAWIN)
-		ppp_print_buffer ("receive buffer", data, count);
-
-	ppp->stats.ppp_ibytes += count;
-	skb = ppp->rpkt;
-	
-	if ( ppp->flags & SC_SYNC ) {
-		/* synchronous mode */
-		
-		if (ppp->toss==0xE0) {
-			/* this is the 1st frame, reset vj comp */
-			ppp_receive_error(ppp);
-			ppp->toss = 0;
-		}
-		
-		/*
-		 * Allocate an skbuff for frame.
-		 * The 128 is room for VJ header expansion.
-		 */
-		
-		if (skb == NULL)
-			skb = dev_alloc_skb(ppp->mru + 128 + PPP_HDRLEN);
-			
-		if (skb == NULL) {
-			if (ppp->flags & SC_DEBUG)
-				printk(KERN_DEBUG "couldn't "
-				       "alloc skb for recv\n");
-		} else {
-			/*
-			 * Decompress A/C and protocol compression here.
-			 */
-			p = skb_put(skb, 2);
-			p[0] = PPP_ALLSTATIONS;
-			p[1] = PPP_UI;
-			if (*data == PPP_ALLSTATIONS) {
-				data += 2;
-				count -= 2;
-			}
-			if ((*data & 1) != 0) {
-				p = skb_put(skb, 1);
-				p[0] = 0;
-			}
-
-			/* copy frame to socket buffer */
-			p = skb_put(skb, count);
-			memcpy(p,data,count);
-			
-			/*
-			 * Check if we've overflowed the MRU
-			 */
-			if (skb->len >= ppp->mru + PPP_HDRLEN + 2
-			    || skb_tailroom(skb) <= 0) {
-				++ppp->estats.rx_length_errors;
-				if (ppp->flags & SC_DEBUG)
-					printk(KERN_DEBUG "rcv frame too long: "
-					       "len=%d mru=%d hroom=%d troom=%d\n",
-					       skb->len, ppp->mru, skb_headroom(skb),
-					       skb_tailroom(skb));
-			} else {
-				if (!ppp_receive_frame(ppp, skb)) {
-					kfree_skb(skb);
-					ppp_receive_error(ppp);
-				}
-			}
-		
-			/* Reset for the next frame */
-			skb = NULL;
-		}
-		ppp->rpkt = skb;
-		return;
-	}
-	
-	while (count-- > 0) {
-		/*
-		 * Collect the character and error condition for the character.
-		 * Set the toss flag for the first character error.
-		 */
-		chr = *data++;
-		if (flags) {
-			flg = *flags++;
-			if (flg) {
-				if (ppp->toss == 0)
-					ppp->toss = flg;
-				switch (flg) {
-				case TTY_OVERRUN:
-					++ppp->estats.rx_fifo_errors;
-					break;
-				case TTY_FRAME:
-				case TTY_BREAK:
-					++ppp->estats.rx_frame_errors;
-					break;
-				}
-				continue;
-			}
-		}
-
-		/*
-		 * Set the flags for d7 being 0/1 and parity being
-		 * even/odd so that the normal processing would have
-		 * all flags set at the end of the session.  A
-		 * missing flag bit indicates an error condition.
-		 */
-
-#ifdef CHECK_CHARACTERS
-		if (chr & 0x80)
-			ppp->flags |= SC_RCV_B7_1;
-		else
-			ppp->flags |= SC_RCV_B7_0;
-
-		if (paritytab[chr >> 5] & (1 << (chr & 0x1F)))
-			ppp->flags |= SC_RCV_ODDP;
-		else
-			ppp->flags |= SC_RCV_EVNP;
-#endif
-
-		if (chr == PPP_FLAG) {
-			/*
-			 * FLAG. This is the end of the block. If the block
-			 * ends with ESC FLAG, then the block is to be ignored.
-			 */
-			if (ppp->escape)
-				ppp->toss |= 0x80;
-			/*
-			 * Process the frame if it was received correctly.
-			 * If there was an error, let the VJ decompressor know.
-			 * There are 4 cases here:
-			 * skb != NULL, toss != 0: error in frame
-			 * skb != NULL, toss == 0: frame ok
-			 * skb == NULL, toss != 0: very first frame,
-			 *	error on 1st char, or alloc_skb failed
-			 * skb == NULL, toss == 0: empty frame (~~)
-			 */
-			if (ppp->toss || !ppp_receive_frame(ppp, skb)) {
-				if (ppp->toss && (ppp->flags & SC_DEBUG))
-					printk(KERN_DEBUG
-					       "ppp: tossing frame (%x)\n",
-					       ppp->toss);
-				if (skb != NULL)
-					kfree_skb(skb);
-				if (!(ppp->toss == 0xE0 || ppp->toss == 0x80))
-					++ppp->stats.ppp_ierrors;
-				ppp_receive_error(ppp);
-			}
-			/*
-			 * Reset for the next frame.
-			 */
-			skb = NULL;
-			ppp->rfcs = PPP_INITFCS;
-			ppp->escape = 0;
-			ppp->toss = 0;
-			continue;
-		}
-
-		/* If we're tossing, look no further. */
-		if (ppp->toss != 0)
-			continue;
-
-		/* If this is a control char to be ignored, do so */
-		if (in_rmap(ppp, chr))
-			continue;
-
-		/*
-		 * Modify the next character if preceded by escape.
-		 * The escape character (0x7d) could be an escaped
-		 * 0x5d, if it follows an escape :-)
-		 */
-		if (ppp->escape) {
-			chr ^= PPP_TRANS;
-			ppp->escape = 0;
-		} else if (chr == PPP_ESCAPE) {
-			ppp->escape = PPP_TRANS;
-			continue;
-		}
-
-		/*
-		 * Allocate an skbuff on the first character received.
-		 * The 128 is room for VJ header expansion and FCS.
-		 */
-		if (skb == NULL) {
-			skb = dev_alloc_skb(ppp->mru + 128 + PPP_HDRLEN);
-			if (skb == NULL) {
-				if (ppp->flags & SC_DEBUG)
-					printk(KERN_DEBUG "couldn't "
-					       "alloc skb for recv\n");
-				ppp->toss = 1;
-				continue;
-			}
-		}
-
-		/*
-		 * Decompress A/C and protocol compression here.
-		 */
-		if (skb->len == 0 && chr != PPP_ALLSTATIONS) {
-			p = skb_put(skb, 2);
-			p[0] = PPP_ALLSTATIONS;
-			p[1] = PPP_UI;
-		}
-		if (skb->len == 2 && (chr & 1) != 0) {
-			p = skb_put(skb, 1);
-			p[0] = 0;
-		}
-
-		/*
-		 * Check if we've overflowed the MRU
-		 */
-		if (skb->len >= ppp->mru + PPP_HDRLEN + 2
-		    || skb_tailroom(skb) <= 0) {
-			++ppp->estats.rx_length_errors;
-			ppp->toss = 0xC0;
-			if (ppp->flags & SC_DEBUG)
-				printk(KERN_DEBUG "rcv frame too long: "
-				       "len=%d mru=%d hroom=%d troom=%d\n",
-				       skb->len, ppp->mru, skb_headroom(skb),
-				       skb_tailroom(skb));
-			continue;
-		}
-
-		/*
-		 * Store the character and update the FCS.
-		 */
-		p = skb_put(skb, 1);
-		*p = chr;
-		ppp->rfcs = PPP_FCS(ppp->rfcs, chr);
-	}
-	ppp->rpkt = skb;
-}
-
-/*************************************************************
- * PPP NETWORK INTERFACE SUPPORT
- *	The following code implements the PPP network
- *	interface device and handles those parts of
- *	the PPP processing which are independent of the
- *	type of hardware link being used, including
- *	VJ and packet compression.
- *************************************************************/
-
-/*
- * Network device driver callback routines
- */
-
-static int ppp_init_dev(struct net_device *dev);
-static int ppp_dev_open(struct net_device *);
-static int ppp_dev_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd);
-static int ppp_dev_close(struct net_device *);
-static int ppp_dev_xmit(struct sk_buff *, struct net_device *);
-static struct net_device_stats *ppp_dev_stats (struct net_device *);
-
-/*
- * Information for the protocol decoder
- */
-
-typedef int (*pfn_proto)  (struct ppp *, struct sk_buff *);
-
-typedef struct ppp_proto_struct {
-	int		proto;
-	pfn_proto	func;
-} ppp_proto_type;
-
-static int rcv_proto_ip		(struct ppp *, struct sk_buff *);
-static int rcv_proto_ipv6	(struct ppp *, struct sk_buff *);
-static int rcv_proto_ipx	(struct ppp *, struct sk_buff *);
-static int rcv_proto_at		(struct ppp *, struct sk_buff *);
-static int rcv_proto_vjc_comp	(struct ppp *, struct sk_buff *);
-static int rcv_proto_vjc_uncomp (struct ppp *, struct sk_buff *);
-static int rcv_proto_ccp	(struct ppp *, struct sk_buff *);
-static int rcv_proto_unknown	(struct ppp *, struct sk_buff *);
-
-static
-ppp_proto_type proto_list[] = {
-	{ PPP_IP,	  rcv_proto_ip	       },
-	{ PPP_IPV6,	  rcv_proto_ipv6       },
-	{ PPP_IPX,	  rcv_proto_ipx	       },
-	{ PPP_AT,	  rcv_proto_at	       },
-	{ PPP_VJC_COMP,	  rcv_proto_vjc_comp   },
-	{ PPP_VJC_UNCOMP, rcv_proto_vjc_uncomp },
-	{ PPP_CCP,	  rcv_proto_ccp	       },
-	{ 0,		  rcv_proto_unknown    }  /* !!! MUST BE LAST !!! */
-};
-
-/*
- * Called when the PPP network interface device is actually created.
- */
-static int
-ppp_init_dev (struct net_device *dev)
-{
-	dev->hard_header_len  = PPP_HDRLEN;
-
-	/* device INFO */
-	dev->mtu	      = PPP_MTU;
-	dev->hard_start_xmit  = ppp_dev_xmit;
-	dev->open	      = ppp_dev_open;
-	dev->stop	      = ppp_dev_close;
-	dev->get_stats	      = ppp_dev_stats;
-	dev->do_ioctl	      = ppp_dev_ioctl;
-	dev->addr_len	      = 0;
-	dev->tx_queue_len     = 10;
-	dev->type	      = ARPHRD_PPP;
-
-	dev_init_buffers(dev);
-
-	dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
-
-	return 0;
-}
-
-/*
- * Callback from the network layer when the device goes up.
- */
-
-static int
-ppp_dev_open (struct net_device *dev)
-{
-	struct ppp *ppp = dev2ppp(dev);
-
-	if (!ppp->inuse || ppp2tty(ppp) == NULL) {
-		printk(KERN_ERR "ppp: %s not active\n", dev->name);
-		return -ENXIO;
-	}
-
-	MOD_INC_USE_COUNT;
-
-	return 0;
-}
-
-/*
- * Callback from the network layer when the ppp device goes down.
- */
-
-static int
-ppp_dev_close (struct net_device *dev)
-{
-	struct ppp *ppp = dev2ppp (dev);
-
-	CHECK_PPP_MAGIC(ppp);
-
-	MOD_DEC_USE_COUNT;
-
-	return 0;
-}
-
-static inline void
-get_vj_stats(struct vjstat *vj, struct slcompress *slc)
-{
-	vj->vjs_packets    = slc->sls_o_compressed + slc->sls_o_uncompressed;
-	vj->vjs_compressed = slc->sls_o_compressed;
-	vj->vjs_searches   = slc->sls_o_searches;
-	vj->vjs_misses     = slc->sls_o_misses;
-	vj->vjs_errorin    = slc->sls_i_error;
-	vj->vjs_tossed     = slc->sls_i_tossed;
-	vj->vjs_uncompressedin = slc->sls_i_uncompressed;
-	vj->vjs_compressedin   = slc->sls_i_compressed;
-}
-
-/*
- * Callback from the network layer to process the sockioctl functions.
- */
-static int
-ppp_dev_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
-{
-	struct ppp *ppp = dev2ppp(dev);
-	int nb;
-	union {
-		struct ppp_stats stats;
-		struct ppp_comp_stats cstats;
-		char vers[32];
-	} u;
-
-	CHECK_PPP_MAGIC(ppp);
-
-	memset(&u, 0, sizeof(u));
-	switch (cmd) {
-	case SIOCGPPPSTATS:
-		u.stats.p = ppp->stats;
-		if (ppp->slcomp != NULL)
-			get_vj_stats(&u.stats.vj, ppp->slcomp);
-		nb = sizeof(u.stats);
-		break;
-
-	case SIOCGPPPCSTATS:
-		if (ppp->sc_xc_state != NULL)
-			(*ppp->sc_xcomp->comp_stat)
-				(ppp->sc_xc_state, &u.cstats.c);
-		if (ppp->sc_rc_state != NULL)
-			(*ppp->sc_rcomp->decomp_stat)
-				(ppp->sc_rc_state, &u.cstats.d);
-		nb = sizeof(u.cstats);
-		break;
-
-	case SIOCGPPPVER:
-		strcpy(u.vers, szVersion);
-		nb = strlen(u.vers) + 1;
-		break;
-
-	default:
-		return -EINVAL;
-	}
-
-	if (copy_to_user((void *) ifr->ifr_ifru.ifru_data, &u, nb))
-		return -EFAULT;
-	return 0;
-}
-
-/*
- * Process the generic PPP ioctls, i.e. those which are not specific
- * to any particular type of hardware link.
- */
-static int
-ppp_ioctl(struct ppp *ppp, unsigned int param2, unsigned long param3)
-{
-	register int temp_i = 0, oldflags;
-	int error = -EFAULT;
-	unsigned long flags;
-	struct ppp_idle cur_ddinfo;
-	struct npioctl npi;
-
-	CHECK_PPP(-ENXIO);
-
-	/*
-	 * The user must have an euid of root to do these requests.
-	 */
-	if (!capable(CAP_NET_ADMIN))
-		return -EPERM;
-
-	switch (param2) {
-	case PPPIOCSMRU:
-		/*
-		 * Set the MRU value
-		 */
-		if (get_user(temp_i, (int *) param3))
-			break;
-		if (temp_i < PPP_MRU)
-			temp_i = PPP_MRU;
-		ppp->mru = temp_i;
-		if (ppp->flags & SC_DEBUG)
-			printk(KERN_INFO
-			       "ppp_ioctl: set mru to %x\n", temp_i);
-		error = 0;
-		break;
-
-	case PPPIOCGFLAGS:
-		/*
-		 * Fetch the current flags
-		 */
-		temp_i = ppp->flags & SC_MASK;
-#ifndef CHECK_CHARACTERS /* Don't generate errors if we don't check chars. */
-		temp_i |= SC_RCV_B7_1 | SC_RCV_B7_0 |
-			  SC_RCV_ODDP | SC_RCV_EVNP;
-#endif
-		if (put_user(temp_i, (int *) param3))
-			break;
-		error = 0;
-		break;
-
-	case PPPIOCSFLAGS:
-		/*
-		 * Set the flags for the various options
-		 */
-		if (get_user(temp_i, (int *) param3))
-			break;
-
-		if (ppp->flags & ~temp_i & SC_CCP_OPEN)
-			ppp_ccp_closed(ppp);
-
-		save_flags(flags);
-		cli();
-		oldflags = ppp->flags;
-		temp_i = (temp_i & SC_MASK) | (oldflags & ~SC_MASK);
-		ppp->flags = temp_i;
-		restore_flags(flags);
-
-		if ((oldflags | temp_i) & SC_DEBUG)
-			printk(KERN_INFO
-			       "ppp_ioctl: set flags to %x\n", temp_i);
-		error = 0;
-		break;
-
-	case PPPIOCSCOMPRESS:
-		/*
-		 * Set the compression mode
-		 */
-		error = ppp_set_compression
-			(ppp, (struct ppp_option_data *) param3);
-		break;
-
-	case PPPIOCGUNIT:
-		/*
-		 * Obtain the unit number for this device.
-		 */
-		if (put_user(ppp->line, (int *) param3))
-			break;
-		if (ppp->flags & SC_DEBUG)
-			printk(KERN_INFO
-			       "ppp_ioctl: get unit: %d\n", ppp->line);
-		error = 0;
-		break;
-
-	case PPPIOCSDEBUG:
-		/*
-		 * Set the debug level
-		 */
-		if (get_user(temp_i, (int *) param3))
-			break;
-		temp_i = (temp_i & 0x1F) << 16;
-
-		if ((ppp->flags | temp_i) & SC_DEBUG)
-			printk(KERN_INFO
-			       "ppp_ioctl: set dbg flags to %x\n", temp_i);
-
-		save_flags(flags);
-		cli();
-		ppp->flags = (ppp->flags & ~0x1F0000) | temp_i;
-		restore_flags(flags);
-		error = 0;
-		break;
-
-	case PPPIOCGDEBUG:
-		/*
-		 * Get the debug level
-		 */
-		temp_i = (ppp->flags >> 16) & 0x1F;
-		if (put_user(temp_i, (int *) param3))
-			break;
-		error = 0;
-		break;
-
-	case PPPIOCGIDLE:
-		/*
-		 * Get the times since the last send/receive frame operation
-		 */
-		/* change absolute times to relative times. */
-		cur_ddinfo.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
-		cur_ddinfo.recv_idle = (jiffies - ppp->last_recv) / HZ;
-		if (copy_to_user((void *) param3, &cur_ddinfo,
-				 sizeof (cur_ddinfo)))
-			break;
-		error = 0;
-		break;
-
-	case PPPIOCSMAXCID:
-		/*
-		 * Set the maximum VJ header compression slot number.
-		 */
-		if (get_user(temp_i, (int *) param3))
-			break;
-		error = -EINVAL;
-		if (temp_i < 2 || temp_i > 255)
-			break;
-		++temp_i;
-		if (ppp->flags & SC_DEBUG)
-			printk(KERN_INFO "ppp_ioctl: set maxcid to %d\n",
-			       temp_i);
-		if (ppp->slcomp != NULL)
-			slhc_free(ppp->slcomp);
-		ppp->slcomp = slhc_init(16, temp_i);
-
-		error = -ENOMEM;
-		if (ppp->slcomp == NULL) {
-			printk(KERN_ERR "ppp: no memory for VJ compression\n");
-			break;
-		}
-		error = 0;
-		break;
-
-	case PPPIOCGNPMODE:
-	case PPPIOCSNPMODE:
-		if (copy_from_user(&npi, (void *) param3, sizeof(npi)))
-			break;
-
-		switch (npi.protocol) {
-		case PPP_IP:
-			npi.protocol = NP_IP;
-			break;
-		case PPP_IPX:
-			npi.protocol = NP_IPX;
-			break;
-		case PPP_AT:
-			npi.protocol = NP_AT;
-			break;
-		default:
-			if (ppp->flags & SC_DEBUG)
-				printk(KERN_DEBUG "pppioc[gs]npmode: "
-				       "invalid proto %d\n", npi.protocol);
-			error = -EINVAL;
-			goto out;
-		}
-
-		if (param2 == PPPIOCGNPMODE) {
-			npi.mode = ppp->sc_npmode[npi.protocol];
-			if (copy_to_user((void *) param3, &npi, sizeof(npi)))
-				break;
-		} else {
-			ppp->sc_npmode[npi.protocol] = npi.mode;
-			if (ppp->flags & SC_DEBUG)
-				printk(KERN_DEBUG "ppp: set np %d to %d\n",
-				       npi.protocol, npi.mode);
-			mark_bh(NET_BH);
-		}
-		error = 0;
-		break;
-
-	default:
-		/*
-		 *  All other ioctl() events will come here.
-		 */
-		if (ppp->flags & SC_DEBUG)
-			printk(KERN_ERR
-			       "ppp_ioctl: invalid ioctl: %x, addr %lx\n",
-			       param2, param3);
-
-		error = -ENOIOCTLCMD;
-		break;
-	}
-out:
-	return error;
-}
-
-/*
- * Process the set-compression ioctl.
- */
-static int
-ppp_set_compression (struct ppp *ppp, struct ppp_option_data *odp)
-{
-	struct compressor *cp;
-	int error, nb;
-	unsigned long flags;
-	__u8 *ptr;
-	__u8 ccp_option[CCP_MAX_OPTION_LENGTH];
-	struct ppp_option_data data;
-
-	/*
-	 * Fetch the compression parameters
-	 */
-	error = -EFAULT;
-	if (copy_from_user(&data, odp, sizeof (data)))
-		goto out;
-
-	nb  = data.length;
-	ptr = data.ptr;
-	if ((unsigned) nb >= CCP_MAX_OPTION_LENGTH)
-		nb = CCP_MAX_OPTION_LENGTH;
-
-	if (copy_from_user(ccp_option, ptr, nb))
-		goto out;
-
-	error = -EINVAL;
-	if (ccp_option[1] < 2)	/* preliminary check on the length byte */
-		goto out;
-
-	save_flags(flags);
-	cli();
-	ppp->flags &= ~(data.transmit? SC_COMP_RUN: SC_DECOMP_RUN);
-	restore_flags(flags);
-
-	cp = find_compressor (ccp_option[0]);
-#ifdef CONFIG_KMOD
-	if (cp == NULL) {
-		char modname[32];
-		sprintf(modname, "ppp-compress-%d", ccp_option[0]);
-		request_module(modname);
-		cp = find_compressor(ccp_option[0]);
-	}
-#endif /* CONFIG_KMOD */
-
-	if (cp == NULL) {
-		if (ppp->flags & SC_DEBUG)
-			printk(KERN_DEBUG
-			       "%s: no compressor for [%x %x %x], %x\n",
-			       ppp->name, ccp_option[0], ccp_option[1],
-			       ccp_option[2], nb);
-		goto out;		/* compressor not loaded */
-	}
-
-	/*
-	 * Found a handler for the protocol - try to allocate
-	 * a compressor or decompressor.
-	 */
-	error = 0;
-	if (data.transmit) {
-		if (ppp->sc_xc_state != NULL)
-			(*ppp->sc_xcomp->comp_free)(ppp->sc_xc_state);
-		ppp->sc_xc_state = NULL;
-
-		ppp->sc_xcomp	 = cp;
-		ppp->sc_xc_state = cp->comp_alloc(ccp_option, nb);
-		if (ppp->sc_xc_state == NULL) {
-			if (ppp->flags & SC_DEBUG)
-				printk(KERN_DEBUG "%s: comp_alloc failed\n",
-				       ppp->name);
-			error = -ENOBUFS;
-		}
-	} else {
-		if (ppp->sc_rc_state != NULL)
-			(*ppp->sc_rcomp->decomp_free)(ppp->sc_rc_state);
-		ppp->sc_rc_state = NULL;
-
-		ppp->sc_rcomp	 = cp;
-		ppp->sc_rc_state = cp->decomp_alloc(ccp_option, nb);
-		if (ppp->sc_rc_state == NULL) {
-			if (ppp->flags & SC_DEBUG)
-				printk(KERN_DEBUG "%s: decomp_alloc failed\n",
-				       ppp->name);
-			error = -ENOBUFS;
-		}
-	}
-out:
-	return error;
-}
-
-/*
- * Handle a CCP packet.
- *
- * The CCP packet is passed along to the pppd process just like any
- * other PPP frame. The difference is that some processing needs to be
- * immediate or the compressors will become confused on the peer.
- */
-
-static void ppp_proto_ccp(struct ppp *ppp, __u8 *dp, int len, int rcvd)
-{
-	int slen    = CCP_LENGTH(dp);
-	__u8 *opt = dp	 + CCP_HDRLEN;
-	int opt_len = slen - CCP_HDRLEN;
-	unsigned long flags;
-
-	if (slen > len)
-		return;
-
-	if (ppp->flags & SC_DEBUG)
-		printk(KERN_DEBUG "ppp_proto_ccp rcvd=%d code=%x flags=%x\n",
-		       rcvd, CCP_CODE(dp), ppp->flags);
-	save_flags(flags);
-	switch (CCP_CODE(dp)) {
-	case CCP_CONFREQ:
-	case CCP_TERMREQ:
-	case CCP_TERMACK:
-		/*
-		 * CCP must be going down - disable compression
-		 */
-		if (ppp->flags & SC_CCP_UP) {
-			cli();
-			ppp->flags &= ~(SC_CCP_UP   |
-					SC_COMP_RUN |
-					SC_DECOMP_RUN);
-		}
-		break;
-
-	case CCP_CONFACK:
-		if ((ppp->flags & SC_CCP_OPEN) == 0)
-			break;
-		if (ppp->flags & SC_CCP_UP)
-			break;
-		if (slen < (CCP_HDRLEN + CCP_OPT_MINLEN))
-			break;
-		if (slen < (CCP_OPT_LENGTH (opt) + CCP_HDRLEN))
-			break;
-		if (!rcvd) {
-			/*
-			 * we're agreeing to send compressed packets.
-			 */
-			if (ppp->sc_xc_state == NULL)
-				break;
-
-			if ((*ppp->sc_xcomp->comp_init)
-			    (ppp->sc_xc_state,
-			     opt, opt_len,
-			     ppp->line, 0, ppp->flags & SC_DEBUG)) {
-				if (ppp->flags & SC_DEBUG)
-					printk(KERN_DEBUG "%s: comp running\n",
-					       ppp->name);
-				cli();
-				ppp->flags |= SC_COMP_RUN;
-			}
-			break;
-		}
-
-		/*
-		 * peer is agreeing to send compressed packets.
-		 */
-		if (ppp->sc_rc_state == NULL)
-			break;
-
-		if ((*ppp->sc_rcomp->decomp_init)
-		    (ppp->sc_rc_state,
-		     opt, opt_len,
-		     ppp->line, 0, ppp->mru, ppp->flags & SC_DEBUG)) {
-			if (ppp->flags & SC_DEBUG)
-				printk(KERN_DEBUG "%s: decomp running\n",
-				       ppp->name);
-			cli();
-			ppp->flags |= SC_DECOMP_RUN;
-			ppp->flags &= ~(SC_DC_ERROR | SC_DC_FERROR);
-		}
-		break;
-
-	case CCP_RESETACK:
-		/*
-		 * CCP Reset-ack resets compressors and decompressors
-		 * as it passes through.
-		 */
-		if ((ppp->flags & SC_CCP_UP) == 0)
-			break;
-
-		if (!rcvd) {
-			if (ppp->sc_xc_state && (ppp->flags & SC_COMP_RUN)) {
-				(*ppp->sc_xcomp->comp_reset)(ppp->sc_xc_state);
-				if (ppp->flags & SC_DEBUG)
-					printk(KERN_DEBUG "%s: comp reset\n",
-					       ppp->name);
-			}
-		} else {
-			if (ppp->sc_rc_state && (ppp->flags & SC_DECOMP_RUN)) {
-			      (*ppp->sc_rcomp->decomp_reset)(ppp->sc_rc_state);
-			      if (ppp->flags & SC_DEBUG)
-					printk(KERN_DEBUG "%s: decomp reset\n",
-					       ppp->name);
-			      cli();
-			      ppp->flags &= ~SC_DC_ERROR;
-			}
-		}
-		break;
-	}
-	restore_flags(flags);
-}
-
-/*
- * CCP is down; free (de)compressor state if necessary.
- */
-
-static void
-ppp_ccp_closed(struct ppp *ppp)
-{
-	unsigned long flags;
-
-	save_flags(flags);
-	cli();
-	ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP | SC_COMP_RUN | SC_DECOMP_RUN);
-	restore_flags(flags);
-	if (ppp->flags & SC_DEBUG)
-		printk(KERN_DEBUG "%s: ccp closed\n", ppp->name);
-	if (ppp->sc_xc_state) {
-		(*ppp->sc_xcomp->comp_free) (ppp->sc_xc_state);
-		ppp->sc_xc_state = NULL;
-	}
-
-	if (ppp->sc_rc_state) {
-		(*ppp->sc_rcomp->decomp_free) (ppp->sc_rc_state);
-		ppp->sc_rc_state = NULL;
-	}
-}
-
-/*************************************************************
- * RECEIVE-SIDE ROUTINES
- *************************************************************/
-
-/*
- * On entry, a received frame is in skb.
- * Check it and dispose as appropriate.
- */
-static int
-ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb)
-{
-	__u8	*data;
-	int	count;
-	int	proto;
-	int	new_count;
-	struct sk_buff *new_skb;
-	ppp_proto_type	*proto_ptr;
-
-	/*
-	 * An empty frame is ignored. This occurs if the FLAG sequence
-	 * precedes and follows each frame.
-	 */
-	if (skb == NULL)
-		return 1;
-	if (skb->len == 0) {
-		kfree_skb(skb);
-		return 1;
-	}
-	data = skb->data;
-	count = skb->len;
-
-	/*
-	 * Generate an error if the frame is too small.
-	 */
-	if (count < PPP_HDRLEN + 2) {
-		if (ppp->flags & SC_DEBUG)
-			printk(KERN_DEBUG
-			       "ppp: got runt ppp frame, %d chars\n", count);
-		++ppp->estats.rx_length_errors;
-		return 0;
-	}
-
-	if ( !(ppp->flags & SC_SYNC) ) { 
-		/*
-		 * Verify the FCS of the frame and discard the FCS characters
-		 * from the end of the buffer.
-		 */
-		if (ppp->rfcs != PPP_GOODFCS) {
-			if (ppp->flags & SC_DEBUG) {
-				printk(KERN_DEBUG
-				       "ppp: frame with bad fcs, length = %d\n",
-				       count);
-				ppp_print_buffer("bad frame", data, count);
-			}
-			++ppp->estats.rx_crc_errors;
-			return 0;
-		}
-		count -= 2;		/* ignore the fcs characters */
-		skb_trim(skb, count);
-	}
-	
-	/*
-	 * Process the active decompressor.
-	 */
-	if (ppp->sc_rc_state != NULL &&
-	    (ppp->flags & SC_DECOMP_RUN) &&
-	    ((ppp->flags & (SC_DC_FERROR | SC_DC_ERROR)) == 0)) {
-		if (PPP_PROTOCOL(data) == PPP_COMP) {
-			/*
-			 * If the frame is compressed then decompress it.
-			 */
-			new_skb = dev_alloc_skb(ppp->mru + 128 + PPP_HDRLEN);
-			if (new_skb == NULL) {
-				printk(KERN_ERR "ppp_recv_frame: no memory\n");
-				new_count = DECOMP_ERROR;
-			} else {
-				new_count = (*ppp->sc_rcomp->decompress)
-					(ppp->sc_rc_state, data, count,
-					 new_skb->data, ppp->mru + PPP_HDRLEN);
-			}
-			if (new_count > 0) {
-				/* Frame was decompressed OK */
-				kfree_skb(skb);
-				skb = new_skb;
-				count = new_count;
-				data = skb_put(skb, count);
-
-			} else {
-				/*
-				 * On a decompression error, we pass the
-				 * compressed frame up to pppd as an
-				 * error indication.
-				 */
-				if (ppp->flags & SC_DEBUG)
-					printk(KERN_INFO "%s: decomp err %d\n",
-					       ppp->name, new_count);
-				if (new_skb != 0)
-					kfree_skb(new_skb);
-				if (ppp->slcomp != 0)
-					slhc_toss(ppp->slcomp);
-				++ppp->stats.ppp_ierrors;
-				if (new_count == DECOMP_FATALERROR) {
-					ppp->flags |= SC_DC_FERROR;
-				} else {
-					ppp->flags |= SC_DC_ERROR;
-				}
-			}
-
-
-		} else {
-			/*
-			 * The frame is not compressed. Pass it to the
-			 * decompression code so it can update its
-			 * dictionary if necessary.
-			 */
-			(*ppp->sc_rcomp->incomp)(ppp->sc_rc_state,
-						 data, count);
-		}
-	}
-	else if (PPP_PROTOCOL(data) == PPP_COMP && (ppp->flags & SC_DEBUG))
-		printk(KERN_INFO "%s: not decomp, rc_state=%p flags=%x\n",
-		       ppp->name, ppp->sc_rc_state, ppp->flags);
-
-	/*
-	 * Count the frame and print it
-	 */
-	++ppp->stats.ppp_ipackets;
-	ppp->stats.ppp_ioctects += count;
-	if (ppp->flags & SC_LOG_INPKT)
-		ppp_print_buffer ("receive frame", data, count);
-
-	/*
-	 * Find the procedure to handle this protocol.
-	 * The last one is marked as protocol 0 which is the 'catch-all'
-	 * to feed it to the pppd daemon.
-	 */
-	proto = PPP_PROTOCOL(data);
-	proto_ptr = proto_list;
-	while (proto_ptr->proto != 0 && proto_ptr->proto != proto)
-		++proto_ptr;
-
-	/*
-	 * Update the appropriate statistic counter.
-	 */
-	if (!(*proto_ptr->func)(ppp, skb)) {
-		kfree_skb(skb);
-		++ppp->stats.ppp_discards;
-	}
-
-	return 1;
-}
-
-/*
- * An input error has been detected, so we need to inform
- * the VJ decompressor.
- */
-static void
-ppp_receive_error(struct ppp *ppp)
-{
-	CHECK_PPP_VOID();
-
-	if (ppp->slcomp != 0)
-		slhc_toss(ppp->slcomp);
-}
-
-/*
- * Put the input frame into the networking system for the indicated protocol
- */
-static int
-ppp_rcv_rx(struct ppp *ppp, __u16 proto, struct sk_buff *skb)
-{
-
-	/*
-	 * Fill in a few fields of the skb and give it to netif_rx().
-	 */
-	skb->dev      = ppp2dev(ppp);	/* We are the device */
-	skb->protocol = htons(proto);
-	skb_pull(skb, PPP_HDRLEN);	/* pull off ppp header */
-	skb->mac.raw   = skb->data;
-	ppp->last_recv = jiffies;
-	netif_rx (skb);
-	return 1;
-}
-
-/*
- * Process the receipt of an IP frame
- */
-static int
-rcv_proto_ip(struct ppp *ppp, struct sk_buff *skb)
-{
-	CHECK_PPP(0);
-	if ((ppp2dev(ppp)->flags & IFF_UP) && (skb->len > 0)
-	    && ppp->sc_npmode[NP_IP] == NPMODE_PASS)
-		return ppp_rcv_rx(ppp, ETH_P_IP, skb);
-	return 0;
-}
-
-/*
- * Process the receipt of an IPv6 frame
- */
-static int
-rcv_proto_ipv6(struct ppp *ppp, struct sk_buff *skb)
-{
-	CHECK_PPP(0);
-	if ((ppp2dev(ppp)->flags & IFF_UP) && (skb->len > 0)
-	    && ppp->sc_npmode[NP_IPV6] == NPMODE_PASS)
-		return ppp_rcv_rx(ppp, ETH_P_IPV6, skb);
-	return 0;
-}
-
-/*
- * Process the receipt of an IPX frame
- */
-static int
-rcv_proto_ipx(struct ppp *ppp, struct sk_buff *skb)
-{
-	CHECK_PPP(0);
-	if (((ppp2dev(ppp)->flags & IFF_UP) != 0) && (skb->len > 0)
-	    && ppp->sc_npmode[NP_IPX] == NPMODE_PASS)
-		return ppp_rcv_rx(ppp, ETH_P_IPX, skb);
-	return 0;
-}
-
-/*
- * Process the receipt of an Appletalk frame
- */
-static int
-rcv_proto_at(struct ppp *ppp, struct sk_buff *skb)
-{
-	CHECK_PPP(0);
-	if ((ppp2dev(ppp)->flags & IFF_UP) && (skb->len > 0)
-	    && ppp->sc_npmode[NP_AT] == NPMODE_PASS)
-		return ppp_rcv_rx(ppp, ETH_P_PPPTALK, skb);
-	return 0;
-}
-
-/*
- * Process the receipt of an VJ Compressed frame
- */
-static int
-rcv_proto_vjc_comp(struct ppp *ppp, struct sk_buff *skb)
-{
-	int new_count;
-
-	CHECK_PPP(0);
-	if ((ppp->flags & SC_REJ_COMP_TCP) || ppp->slcomp == NULL)
-		return 0;
-	new_count = slhc_uncompress(ppp->slcomp, skb->data + PPP_HDRLEN,
-				    skb->len - PPP_HDRLEN);
-	if (new_count <= 0) {
-		if (ppp->flags & SC_DEBUG)
-			printk(KERN_NOTICE
-			       "ppp: error in VJ decompression\n");
-		return 0;
-	}
-	new_count += PPP_HDRLEN;
-	if (new_count > skb->len)
-		skb_put(skb, new_count - skb->len);
-	else
-		skb_trim(skb, new_count);
-	return rcv_proto_ip(ppp, skb);
-}
-
-/*
- * Process the receipt of an VJ Un-compressed frame
- */
-static int
-rcv_proto_vjc_uncomp(struct ppp *ppp, struct sk_buff *skb)
-{
-	CHECK_PPP(0);
-	if ((ppp->flags & SC_REJ_COMP_TCP) || ppp->slcomp == NULL)
-		return 0;
-	if (slhc_remember(ppp->slcomp, skb->data + PPP_HDRLEN,
-			  skb->len - PPP_HDRLEN) <= 0) {
-		if (ppp->flags & SC_DEBUG)
-			printk(KERN_NOTICE "ppp: error in VJ memorizing\n");
-		return 0;
-	}
-	return rcv_proto_ip(ppp, skb);
-}
-
-static int
-rcv_proto_ccp(struct ppp *ppp, struct sk_buff *skb)
-{
-	CHECK_PPP(0);
-	ppp_proto_ccp (ppp, skb->data + PPP_HDRLEN, skb->len - PPP_HDRLEN, 1);
-	return rcv_proto_unknown(ppp, skb);
-}
-
-/*
- * Receive all unclassified protocols.
- */
-static int
-rcv_proto_unknown(struct ppp *ppp, struct sk_buff *skb)
-{
-	CHECK_PPP(0);
-
-	/*
-	 * Limit queue length by dropping old frames.
-	 */
-	skb_queue_tail(&ppp->rcv_q, skb);
-	while (ppp->rcv_q.qlen > PPP_MAX_RCV_QLEN) {
-		struct sk_buff *skb = skb_dequeue(&ppp->rcv_q);
-		if (skb)
-			kfree_skb(skb);
-	}
-
-	wake_up_interruptible (&ppp->read_wait);
-	if (ppp->tty->fasync != NULL)
-		kill_fasync (ppp->tty->fasync, SIGIO);
-
-	return 1;
-}
-
-/*************************************************************
- * TRANSMIT-SIDE ROUTINES
- *************************************************************/
-
-/* local function to store a value into the LQR frame */
-extern inline __u8 * store_long (register __u8 *p, register int value) {
-	*p++ = (__u8) (value >> 24);
-	*p++ = (__u8) (value >> 16);
-	*p++ = (__u8) (value >>	 8);
-	*p++ = (__u8) value;
-	return p;
-}
-
-/*
- * Compress and send an frame to the peer.
- * Should be called with xmit_busy == 1, having been set by the caller.
- * That is, we use xmit_busy as a lock to prevent reentry of this
- * procedure.
- */
-static void
-ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
-{
-	int	proto;
-	__u8	*data;
-	int	count;
-	__u8	*p;
-	int	ret;
-
-	CHECK_PPP_VOID();
-	data = skb->data;
-	count = skb->len;
-
-	/* dump the buffer */
-	if (ppp->flags & SC_LOG_OUTPKT)
-		ppp_print_buffer ("write frame", data, count);
-
-	/*
-	 * Handle various types of protocol-specific compression
-	 * and other processing, including:
-	 * - VJ TCP header compression
-	 * - updating LQR packets
-	 * - updating CCP state on CCP packets
-	 */
-	proto = PPP_PROTOCOL(data);
-	switch (proto) {
-	case PPP_IP:
-		if ((ppp->flags & SC_COMP_TCP) && ppp->slcomp != NULL)
-			skb = ppp_vj_compress(ppp, skb);
-		break;
-
-	case PPP_LQR:
-		/*
-		 * Update the LQR frame with the current MIB information.
-		 * This way the information is accurate and up-to-date.
-		 */
-		if (count < 48)
-			break;
-		p = data + 40;	/* Point to last two items. */
-		p = store_long(p, ppp->stats.ppp_opackets + 1);
-		p = store_long(p, ppp->stats.ppp_ooctects + count);
-		++ppp->stats.ppp_olqrs;
-		break;
-
-	case PPP_CCP:
-		/*
-		 * Outbound compression control frames
-		 */
-		ppp_proto_ccp(ppp, data + PPP_HDRLEN, count - PPP_HDRLEN, 0);
-		break;
-	}
-	data = skb->data;
-	count = skb->len;
-
-	/*
-	 * Compress the whole frame if possible.
-	 */
-	if (((ppp->flags & SC_COMP_RUN) != 0)	&&
-	    (ppp->sc_xc_state != (void *) 0)	&&
-	    (proto != PPP_LCP)			&&
-	    (proto != PPP_CCP)) {
-		struct sk_buff *new_skb;
-		int new_count;
-
-		/* Allocate an skb for the compressed frame. */
-		new_skb = alloc_skb(ppp->mtu + PPP_HDRLEN, GFP_ATOMIC);
-		if (new_skb == NULL) {
-			printk(KERN_ERR "ppp_send_frame: no memory\n");
-			kfree_skb(skb);
-			ppp->xmit_busy = 0;
-			return;
-		}
-
-		/* Compress the frame. */
-		new_count = (*ppp->sc_xcomp->compress)
-			(ppp->sc_xc_state, data, new_skb->data,
-			 count, ppp->mtu + PPP_HDRLEN);
-
-		/* Did it compress? */
-		if (new_count > 0 && (ppp->flags & SC_CCP_UP)) {
-			skb_put(new_skb, new_count);
-			kfree_skb(skb);
-			skb = new_skb;
-		} else {
-			/*
-			 * The frame could not be compressed, or it could not
-			 * be sent in compressed form because CCP is down.
-			 */
-			kfree_skb(new_skb);
-		}
-	}
-
-	/*
-	 * Send the frame
-	 */
-	if ( ppp->flags & SC_SYNC ) 
-		ret = ppp_sync_send(ppp, skb);
-	else
-		ret = ppp_async_send(ppp, skb);
-	if (ret > 0) {
-		/* we can release the lock */
-		ppp->xmit_busy = 0;
-	} else if (ret < 0) {
-		/* can't happen, since the caller got the xmit_busy lock */
-		printk(KERN_ERR "ppp: ppp_async_send didn't accept pkt\n");
-	}
-}
-
-/*
- * Apply VJ TCP header compression to a packet.
- */
-static struct sk_buff *
-ppp_vj_compress(struct ppp *ppp, struct sk_buff *skb)
-{
-	__u8 *orig_data, *data;
-	struct sk_buff *new_skb;
-	int len, proto;
-
-	new_skb = alloc_skb(skb->len, GFP_ATOMIC);
-	if (new_skb == NULL) {
-		printk(KERN_ERR "ppp: no memory for vj compression\n");
-		return skb;
-	}
-
-	orig_data = data = skb->data + PPP_HDRLEN;
-	len = slhc_compress(ppp->slcomp, data, skb->len - PPP_HDRLEN,
-			    new_skb->data + PPP_HDRLEN, &data,
-			    (ppp->flags & SC_NO_TCP_CCID) == 0);
-
-	if (data == orig_data) {
-		/* Couldn't compress the data */
-		kfree_skb(new_skb);
-		return skb;
-	}
-
-	/* The data has been changed */
-	if (data[0] & SL_TYPE_COMPRESSED_TCP) {
-		proto = PPP_VJC_COMP;
-		data[0] ^= SL_TYPE_COMPRESSED_TCP;
-	} else {
-		if (data[0] >= SL_TYPE_UNCOMPRESSED_TCP)
-			proto = PPP_VJC_UNCOMP;
-		else
-			proto = PPP_IP;
-		data[0] = orig_data[0];
-	}
-
-	data = skb_put(new_skb, len + PPP_HDRLEN);
-	data[0] = PPP_ALLSTATIONS;
-	data[1] = PPP_UI;
-	data[2] = 0;
-	data[3] = proto;
-
-	kfree_skb(skb);
-	return new_skb;
-}
-
-static inline void
-ppp_send_frames(struct ppp *ppp)
-{
-	struct sk_buff *skb;
-
-	while (!test_and_set_bit(0, &ppp->xmit_busy)) {
-		skb = skb_dequeue(&ppp->xmt_q);
-		if (skb == NULL) {
-			ppp->xmit_busy = 0;
-			break;
-		}
-		ppp_send_frame(ppp, skb);
-	}
-	if (!ppp->xmit_busy && ppp->dev.tbusy) {
-		ppp->dev.tbusy = 0;
-		mark_bh(NET_BH);
-	}
-}
-
-/*
- * Called from the hardware (tty) layer when it can accept
- * another packet.
- */
-static void
-ppp_output_wakeup(struct ppp *ppp)
-{
-	CHECK_PPP_VOID();
-
-	if (!ppp->xmit_busy) {
-		printk(KERN_ERR "ppp_output_wakeup called but xmit_busy==0\n");
-		return;
-	}
-	ppp->xmit_busy = 0;
-	ppp_send_frames(ppp);
-}
-
-/*
- * Send a control frame (from pppd).
- */
-static void
-ppp_send_ctrl(struct ppp *ppp, struct sk_buff *skb)
-{
-	CHECK_PPP_VOID();
-
-	/*
-	 * Put the packet on the queue, then send as many as we can.
-	 */
-	skb_queue_tail(&ppp->xmt_q, skb);
-	ppp_send_frames(ppp);
-}
-
-
-/*************************************************************
- * NETWORK OUTPUT
- *    This routine accepts requests from the network layer
- *    and attempts to deliver the packets.
- *************************************************************/
-/*
- * Send a frame to the peer.
- * Returns 1 iff the frame was not accepted.
- */
-static int
-ppp_dev_xmit(struct sk_buff *skb, struct net_device *dev)
-{
-	struct ppp *ppp = dev2ppp(dev);
-	struct tty_struct *tty = ppp2tty(ppp);
-	enum NPmode npmode;
-	int proto;
-	unsigned char *hdr;
-
-	/* just a little sanity check. */
-	if (skb == NULL)
-		return 0;
-	if (skb->data == NULL) {
-		kfree_skb(skb);
-		return 0;
-	}
-
-	/*
-	 * Avoid timing problem should tty hangup while data is
-	 * queued to be sent.
-	 */
-	if (!ppp->inuse) {
-		dev_kfree_skb(skb);
-		return 0;
-	}
-
-	/*
-	 * Validate the tty interface
-	 */
-	if (tty == NULL) {
-		if (ppp->flags & SC_DEBUG)
-			printk(KERN_ERR
-			       "ppp_dev_xmit: %s not connected to a TTY!\n",
-			       dev->name);
-		dev_kfree_skb(skb);
-		return 0;
-	}
-
-	/*
-	 * Work out the appropriate network-protocol mode for this packet.
-	 */
-	npmode = NPMODE_PASS;	/* default */
-	switch (ntohs(skb->protocol)) {
-	case ETH_P_IP:
-		proto = PPP_IP;
-		npmode = ppp->sc_npmode[NP_IP];
-		break;
-	case ETH_P_IPV6:
-		proto = PPP_IPV6;
-		npmode = ppp->sc_npmode[NP_IPV6];
-		break;
-	case ETH_P_IPX:
-		proto = PPP_IPX;
-		npmode = ppp->sc_npmode[NP_IPX];
-		break;
-	case ETH_P_PPPTALK:
-	case ETH_P_ATALK:
-		proto = PPP_AT;
-		npmode = ppp->sc_npmode[NP_AT];
-		break;
-	default:
-		if (ppp->flags & SC_DEBUG)
-			printk(KERN_INFO "%s: packet for unknown proto %x\n",
-			       ppp->name, ntohs(skb->protocol));
-		dev_kfree_skb(skb);
-		return 0;
-	}
-
-	/*
-	 * Drop, accept or reject the packet depending on the mode.
-	 */
-	switch (npmode) {
-	case NPMODE_PASS:
-		break;
-
-	case NPMODE_QUEUE:
-		/*
-		 * We may not send the packet now, so drop it.
-		 * XXX It would be nice to be able to return it to the
-		 * network system to be queued and retransmitted later.
-		 */
-		if (ppp->flags & SC_DEBUG)
-			printk(KERN_DEBUG "%s: returning frame\n", ppp->name);
-		dev_kfree_skb(skb);
-		return 0;
-
-	case NPMODE_ERROR:
-	case NPMODE_DROP:
-		if (ppp->flags & SC_DEBUG)
-			printk(KERN_DEBUG
-			       "ppp_dev_xmit: dropping (npmode = %d) on %s\n",
-			       npmode, ppp->name);
-		dev_kfree_skb(skb);
-		return 0;
-	}
-
-	/*
-	 * The dev->tbusy field acts as a lock to allow only
-	 * one packet to be processed at a time.  If we can't
-	 * get the lock, try again later.
-	 * We deliberately queue as little as possible inside
-	 * the ppp driver in order to minimize the latency
-	 * for high-priority packets.
-	 */
-	if (test_and_set_bit(0, &ppp->xmit_busy)) {
-		dev->tbusy = 1;	/* can't take it now */
-		return 1;
-	}
-	dev->tbusy = 0;
-
-	/*
-	 * Put the 4-byte PPP header on the packet.
-	 * If there isn't room for it, we have to copy the packet.
-	 */
-	if (skb_headroom(skb) < PPP_HDRLEN) {
-		struct sk_buff *new_skb;
-
-		new_skb = alloc_skb(skb->len + PPP_HDRLEN, GFP_ATOMIC);
-		if (new_skb == NULL) {
-			printk(KERN_ERR "%s: skb hdr alloc failed\n",
-			       ppp->name);
-			dev_kfree_skb(skb);
-			ppp->xmit_busy = 0;
-			ppp_send_frames(ppp);
-			return 0;
-		}
-		skb_reserve(new_skb, PPP_HDRLEN);
-		memcpy(skb_put(new_skb, skb->len), skb->data, skb->len);
-		dev_kfree_skb(skb);
-		skb = new_skb;
-	}
-
-	hdr = skb_push(skb, PPP_HDRLEN);
-	hdr[0] = PPP_ALLSTATIONS;
-	hdr[1] = PPP_UI;
-	hdr[2] = proto >> 8;
-	hdr[3] = proto;
-
-	ppp_send_frame(ppp, skb);
-	if (!ppp->xmit_busy)
-		ppp_send_frames(ppp);
-	return 0;
-}
-
-/*
- * Generate the statistic information for the /proc/net/dev listing.
- */
-static struct net_device_stats *
-ppp_dev_stats (struct net_device *dev)
-{
-	struct ppp *ppp = dev2ppp (dev);
-
-	ppp->estats.rx_packets = ppp->stats.ppp_ipackets;
-	ppp->estats.rx_errors  = ppp->stats.ppp_ierrors;
-	ppp->estats.tx_packets = ppp->stats.ppp_opackets;
-	ppp->estats.tx_errors  = ppp->stats.ppp_oerrors;
-	ppp->estats.rx_bytes   = ppp->stats.ppp_ibytes;
-	ppp->estats.tx_bytes   = ppp->stats.ppp_obytes;
-
-	return &ppp->estats;
-}
-
-/*************************************************************
- * UTILITIES
- *    Miscellany called by various functions above.
- *************************************************************/
-
-/* Locate the previous instance of the PPP channel */
-static struct ppp *
-ppp_find(int pid_value)
-{
-	struct ppp	*ppp;
-
-	/* try to find the device which this pid is already using */
-	for (ppp = ppp_list; ppp != 0; ppp = ppp->next) {
-		if (ppp->inuse && ppp->sc_xfer == pid_value) {
-			ppp->sc_xfer = 0;
-			break;
-		}
-	}
-	return ppp;
-}
-
-/* allocate or create a PPP channel */
-static struct ppp *
-ppp_alloc(void)
-{
-	int		if_num;
-	int		status;
-	struct net_device	*dev;
-	struct ppp	*ppp;
-
-	/* try to find an free device */
-	for (ppp = ppp_list; ppp != 0; ppp = ppp->next) {
-		if (!test_and_set_bit(0, &ppp->inuse)) {
-			dev = ppp2dev(ppp);
-			if (dev->flags & IFF_UP) {
-				clear_bit(0, &ppp->inuse);
-				continue;
-			}
-			/* Reregister device */
-			unregister_netdev(dev);
-			if (register_netdev(dev) == 0)
-				return ppp;
-			printk(KERN_DEBUG "could not reregister ppp device\n");
-			/* leave inuse set in this case */
-		}
-	}
-
-	/*
-	 * There are no available units, so make a new one.
-	 */
-	ppp = (struct ppp *) kmalloc(sizeof(struct ppp), GFP_KERNEL);
-	if (ppp == 0) {
-		printk(KERN_ERR "ppp: struct ppp allocation failed\n");
-		return 0;
-	}
-	memset(ppp, 0, sizeof(*ppp));
-
-	/* initialize channel control data */
-	ppp->magic = PPP_MAGIC;
-	ppp->next = NULL;
-	ppp->inuse = 1;
-	init_waitqueue_head(&ppp->read_wait);
-
-	/*
-	 * Make up a suitable name for this device
-	 */
-	dev = ppp2dev(ppp);
-	dev->name = ppp->name;
-	if_num = dev_alloc_name(dev, "ppp%d");
-	if (if_num < 0) {
-		printk(KERN_ERR "ppp: dev_alloc_name failed (%d)\n", if_num);
-		kfree(ppp);
-		return 0;
-	}
-	ppp->line = if_num;
-	ppp->slcomp = NULL;
-
-	dev->next = NULL;
-	dev->init = ppp_init_dev;
-	dev->name = ppp->name;
-	dev->priv = (void *) ppp;
-
-	/* register device so that we can be ifconfig'd */
-	/* ppp_init_dev() will be called as a side-effect */
-	status = register_netdev (dev);
-	if (status == 0) {
-		printk(KERN_INFO "registered device %s\n", dev->name);
-	} else {
-		printk(KERN_ERR
-		       "ppp_alloc - register_netdev(%s) = %d failure.\n",
-		       dev->name, status);
-		kfree(ppp);
-		ppp = NULL;
-	}
-
-	/* link this unit into our list */
-	if (ppp_list == 0)
-		ppp_list = ppp;
-	else
-		ppp_last->next = ppp;
-	ppp_last = ppp;
-
-	return ppp;
-}
-
-/*
- * Initialize the generic parts of the ppp structure.
- */
-static void
-ppp_generic_init(struct ppp *ppp)
-{
-	int indx;
-
-	ppp->flags  = 0;
-	ppp->mtu    = PPP_MTU;
-	ppp->mru    = PPP_MRU;
-
-	skb_queue_head_init(&ppp->xmt_q);
-	skb_queue_head_init(&ppp->rcv_q);
-
-	ppp->last_xmit	= jiffies;
-	ppp->last_recv  = jiffies;
-	ppp->xmit_busy  = 0;
-
-	/* clear statistics */
-	memset(&ppp->stats, 0, sizeof (struct pppstat));
-	memset(&ppp->estats, 0, sizeof(struct net_device_stats));
-
-	/* PPP compression data */
-	ppp->sc_xc_state = NULL;
-	ppp->sc_rc_state = NULL;
-
-	for (indx = 0; indx < NUM_NP; ++indx)
-		ppp->sc_npmode[indx] = NPMODE_PASS;
-}
-
-/*
- * Called to clean up the generic parts of the ppp structure.
- */
-static void
-ppp_release(struct ppp *ppp)
-{
-	struct sk_buff *skb;
-
-	CHECK_PPP_MAGIC(ppp);
-
-	if (ppp->flags & SC_DEBUG)
-		printk(KERN_DEBUG "%s released\n", ppp->name);
-
-	ppp_ccp_closed(ppp);
-
-        /* Ensure that the pppd process is not hanging on select()/poll() */
-        wake_up_interruptible(&ppp->read_wait);
-
-	if (ppp->slcomp) {
-		slhc_free(ppp->slcomp);
-		ppp->slcomp = NULL;
-	}
-
-	while ((skb = skb_dequeue(&ppp->rcv_q)) != NULL)
-		kfree_skb(skb);
-	while ((skb = skb_dequeue(&ppp->xmt_q)) != NULL)
-		kfree_skb(skb);
-
-	ppp->inuse = 0;
-	if (ppp->dev.tbusy) {
-		ppp->dev.tbusy = 0;
-		mark_bh(NET_BH);
-	}
-}
-
-/*
- * 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 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: %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);
-	}
-}
-
-/*************************************************************
- * Compressor module interface
- *************************************************************/
-
-struct compressor_link {
-	struct compressor_link	*next;
-	struct compressor	*comp;
-};
-
-static struct compressor_link *ppp_compressors = (struct compressor_link *) 0;
-
-static struct compressor *find_compressor (int type)
-{
-	struct compressor_link *lnk;
-	unsigned long flags;
-
-	save_flags(flags);
-	cli();
-
-	lnk = ppp_compressors;
-	while (lnk != (struct compressor_link *) 0) {
-		if ((int) (__u8) lnk->comp->compress_proto == type) {
-			restore_flags(flags);
-			return lnk->comp;
-		}
-		lnk = lnk->next;
-	}
-
-	restore_flags(flags);
-	return (struct compressor *) 0;
-}
-
-#ifdef CONFIG_MODULES
-static int ppp_register_compressor (struct compressor *cp)
-{
-	struct compressor_link *new;
-	unsigned long flags;
-
-	new = (struct compressor_link *)
-		kmalloc (sizeof (struct compressor_link), GFP_KERNEL);
-
-	if (new == (struct compressor_link *) 0)
-		return 1;
-
-	save_flags(flags);
-	cli();
-
-	if (find_compressor (cp->compress_proto)) {
-		restore_flags(flags);
-		kfree (new);
-		return 0;
-	}
-
-	new->next	= ppp_compressors;
-	new->comp	= cp;
-	ppp_compressors = new;
-
-	restore_flags(flags);
-	return 0;
-}
-
-static void ppp_unregister_compressor (struct compressor *cp)
-{
-	struct compressor_link *prev = (struct compressor_link *) 0;
-	struct compressor_link *lnk;
-	unsigned long flags;
-
-	save_flags(flags);
-	cli();
-
-	lnk  = ppp_compressors;
-	while (lnk != (struct compressor_link *) 0) {
-		if (lnk->comp == cp) {
-			if (prev)
-				prev->next = lnk->next;
-			else
-				ppp_compressors = lnk->next;
-			kfree (lnk);
-			break;
-		}
-		prev = lnk;
-		lnk  = lnk->next;
-	}
-	restore_flags(flags);
-}
-#endif
-
-/*************************************************************
- * Module support routines
- *************************************************************/
-
-#ifdef MODULE
-int
-init_module(void)
-{
-	int status;
-
-	/* register our line disciplines */
-	status = ppp_first_time();
-	if (status != 0)
-		printk(KERN_INFO "PPP: ppp_init() failure %d\n", status);
-
-	return status;
-}
-
-void
-cleanup_module(void)
-{
-	int status;
-	struct ppp *ppp, *next_ppp;
-	int busy = 0;
-
-	/*
-	 * Ensure that the devices are not in operation.
-	 */
-	for (ppp = ppp_list; ppp != 0; ppp = ppp->next) {
-		CHECK_PPP_MAGIC(ppp);
-		if (ppp->inuse || (ppp->dev.flags & IFF_UP))
-			++busy;
-	}
-	if (busy)
-		printk(KERN_CRIT "PPP: removing despite %d units in use!\n",
-		       busy);
-
-	/*
-	 * Release the tty registration of the line discipline so that
-	 * ttys can no longer be put into PPP line discipline.
-	 */
-	status = tty_register_ldisc (N_PPP, NULL);
-	if (status != 0)
-		printk(KERN_ERR
-		       "PPP: Unable to unregister ppp line discipline "
-		       "(err = %d)\n", status);
-	else
-		printk(KERN_INFO
-		       "PPP: ppp line discipline successfully unregistered\n");
-
-	/*
-	 * De-register the devices so that there is no problem with them
-	 */
-	for (ppp = ppp_list; ppp != 0; ppp = next_ppp) {
-		next_ppp = ppp->next;
-		unregister_netdev(&ppp->dev);
-		kfree (ppp);
-	}
-}
-#endif

FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)