text: /* Modified by Broadcom Corp. Portions Copyright (c) Broadcom Corp, 2012. */
  /*
   * Generic PPP layer for Linux.
   *
   * Copyright 1999-2002 Paul Mackerras.
   *
   *  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.
   *
   * The generic PPP layer handles the PPP network interfaces, the
   * /dev/ppp device, packet and VJ compression, and multilink.
   * It talks to PPP `channels' via the interface defined in
   * include/linux/ppp_channel.h.  Channels provide the basic means for
   * sending and receiving PPP frames on some kind of communications
   * channel.
   *
   * 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 20041108==
   */
  
  #include <linux/module.h>
  #include <linux/kernel.h>
  #include <linux/kmod.h>
  #include <linux/init.h>
  #include <linux/list.h>
  #include <linux/idr.h>
  #include <linux/netdevice.h>
  #include <linux/poll.h>
  #include <linux/ppp_defs.h>
  #include <linux/filter.h>
  #include <linux/if_ppp.h>
  #include <linux/ppp_channel.h>
  #include <linux/ppp-comp.h>
  #include <linux/skbuff.h>
  #include <linux/rtnetlink.h>
  #include <linux/if_arp.h>
  #include <linux/ip.h>
  #include <linux/tcp.h>
  #include <linux/spinlock.h>
  #include <linux/rwsem.h>
  #include <linux/stddef.h>
  #include <linux/device.h>
  #include <linux/mutex.h>
  #include <linux/slab.h>
  #include <net/slhc_vj.h>
  #include <asm/atomic.h>
  
  #include <linux/nsproxy.h>
  #include <net/net_namespace.h>
  #include <net/netns/generic.h>
  
  #ifdef HNDCTF
  #define TYPEDEF_INT32
  #include <ctf/hndctf.h>
  #include <linux/if_pppox.h>
  #endif
  
  #define PPP_VERSION	"2.4.2"
  
  /*
   * Network protocols we support.
   */
  #define NP_IP	0		/* Internet Protocol V4 */
  #define NP_IPV6	1		/* Internet Protocol V6 */
  #define NP_IPX	2		/* IPX protocol */
  #define NP_AT	3		/* Appletalk protocol */
  #define NP_MPLS_UC 4		/* MPLS unicast */
  #define NP_MPLS_MC 5		/* MPLS multicast */
  #define NUM_NP	6		/* Number of NPs. */
  
  #define MPHDRLEN	6	/* multilink protocol header length */
  #define MPHDRLEN_SSN	4	/* ditto with short sequence numbers */
  
  /*
   * An instance of /dev/ppp can be associated with either a ppp
   * interface unit or a ppp channel.  In both cases, file->private_data
   * points to one of these.
   */
  struct ppp_file {
  	enum {
  		INTERFACE=1, CHANNEL
  	}		kind;
  	struct sk_buff_head xq;		/* pppd transmit queue */
  	struct sk_buff_head rq;		/* receive queue for pppd */
  	wait_queue_head_t rwait;	/* for poll on reading /dev/ppp */
  	atomic_t	refcnt;		/* # refs (incl /dev/ppp attached) */
  	int		hdrlen;		/* space to leave for headers */
  	int		index;		/* interface unit / channel number */
  	int		dead;		/* unit/channel has been shut down */
  };
  
  #define PF_TO_X(pf, X)		container_of(pf, X, file)
  
  #define PF_TO_PPP(pf)		PF_TO_X(pf, struct ppp)
  #define PF_TO_CHANNEL(pf)	PF_TO_X(pf, struct channel)
  
  #ifdef HNDCTF 
  typedef struct channel channel_t;
  #endif
  
  /*
   * Data structure describing one ppp unit.
   * A ppp unit corresponds to a ppp network interface device
   * and represents a multilink bundle.
   * It can have 0 or more ppp channels connected to it.
   */
  struct ppp {
  	struct ppp_file	file;		/* stuff for read/write/poll 0 */
  	struct file	*owner;		/* file that owns this unit 48 */
  	struct list_head channels;	/* list of attached channels 4c */
  	int		n_channels;	/* how many channels are attached 54 */
  	spinlock_t	rlock;		/* lock for receive side 58 */
  	spinlock_t	wlock;		/* lock for transmit side 5c */
  	int		mru;		/* max receive unit 60 */
  	unsigned int	flags;		/* control bits 64 */
  	unsigned int	xstate;		/* transmit state bits 68 */
  	unsigned int	rstate;		/* receive state bits 6c */
  	int		debug;		/* debug flags 70 */
  	struct slcompress *vj;		/* state for VJ header compression */
  	enum NPmode	npmode[NUM_NP];	/* what to do with each net proto 78 */
  	struct sk_buff	*xmit_pending;	/* a packet ready to go out 88 */
  	struct compressor *xcomp;	/* transmit packet compressor 8c */
  	void		*xc_state;	/* its internal state 90 */
  	struct compressor *rcomp;	/* receive decompressor 94 */
  	void		*rc_state;	/* its internal state 98 */
  	unsigned long	last_xmit;	/* jiffies when last pkt sent 9c */
  	unsigned long	last_recv;	/* jiffies when last pkt rcvd a0 */
  	struct net_device *dev;		/* network interface device a4 */
  	int		closing;	/* is device closing down? a8 */
  #ifdef CONFIG_PPP_MULTILINK
  	int		nxchan;		/* next channel to send something on */
  	u32		nxseq;		/* next sequence number to send */
  	int		mrru;		/* MP: max reconst. receive unit */
  	u32		nextseq;	/* MP: seq no of next packet */
  	u32		minseq;		/* MP: min of most recent seqnos */
  	struct sk_buff_head mrq;	/* MP: receive reconstruction queue */
  #endif /* CONFIG_PPP_MULTILINK */
  #ifdef CONFIG_PPP_FILTER
  	struct sock_filter *pass_filter;	/* filter for packets to pass */
  	struct sock_filter *active_filter;/* filter for pkts to reset idle */
  	unsigned pass_len, active_len;
  #endif /* CONFIG_PPP_FILTER */
  	struct net	*ppp_net;	/* the net we belong to */
  #ifdef HNDCTF
          channel_t               *ctfpch;
  #endif
  };
  
  /*
   * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
   * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
   * SC_MUST_COMP
   * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
   * Bits in xstate: SC_COMP_RUN
   */
  #define SC_FLAG_BITS	(SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
  			 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
  			 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
  
  /*
   * Private data structure for each channel.
   * This includes the data structure used for multilink.
   */
  struct channel {
  	struct ppp_file	file;		/* stuff for read/write/poll */
  	struct list_head list;		/* link in all/new_channels list */
  	struct ppp_channel *chan;	/* public channel data structure */
  	struct rw_semaphore chan_sem;	/* protects `chan' during chan ioctl */
  	spinlock_t	downl;		/* protects `chan', file.xq dequeue */
  	struct ppp	*ppp;		/* ppp unit we're connected to */
  	struct net	*chan_net;	/* the net channel belongs to */
  	struct list_head clist;		/* link in list of channels per unit */
  	rwlock_t	upl;		/* protects `ppp' */
  #ifdef CONFIG_PPP_MULTILINK
  	u8		avail;		/* flag used in multilink stuff */
  	u8		had_frag;	/* >= 1 fragments have been sent */
  	u32		lastseq;	/* MP: last sequence # received */
  	int		speed;		/* speed of the corresponding ppp channel*/
  #endif /* CONFIG_PPP_MULTILINK */
  };
  
  /*
   * SMP locking issues:
   * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
   * list and the ppp.n_channels field, you need to take both locks
   * before you modify them.
   * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
   * channel.downl.
   */
  
  static DEFINE_MUTEX(ppp_mutex);
  static atomic_t ppp_unit_count = ATOMIC_INIT(0);
  static atomic_t channel_count = ATOMIC_INIT(0);
  
  /* per-net private data for this module */
  static int ppp_net_id __read_mostly;
  struct ppp_net {
  	/* units to ppp mapping */
  	struct idr units_idr;
  
  	/*
  	 * all_ppp_mutex protects the units_idr mapping.
  	 * It also ensures that finding a ppp unit in the units_idr
  	 * map and updating its file.refcnt field is atomic.
  	 */
  	struct mutex all_ppp_mutex;
  
  	/* channels */
  	struct list_head all_channels;
  	struct list_head new_channels;
  	int last_channel_index;
  
  	/*
  	 * all_channels_lock protects all_channels and
  	 * last_channel_index, and the atomicity of find
  	 * a channel and updating its file.refcnt field.
  	 */
  	spinlock_t all_channels_lock;
  };
  
  /* Get the PPP protocol number from a skb */
  #define PPP_PROTO(skb)	(((skb)->data[0] << 8) + (skb)->data[1])
  
  /* We limit the length of ppp->file.rq to this (arbitrary) value */
  #define PPP_MAX_RQLEN	32
  
  /*
   * Maximum number of multilink fragments queued up.
   * This has to be large enough to cope with the maximum latency of
   * the slowest channel relative to the others.  Strictly it should
   * depend on the number of channels and their characteristics.
   */
  #define PPP_MP_MAX_QLEN	128
  
  /* Multilink header bits. */
  #define B	0x80		/* this fragment begins a packet */
  #define E	0x40		/* this fragment ends a packet */
  
  /* Compare multilink sequence numbers (assumed to be 32 bits wide) */
  #define seq_before(a, b)	((s32)((a) - (b)) < 0)
  #define seq_after(a, b)		((s32)((a) - (b)) > 0)
  
  /* Prototypes. */
  static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
  			struct file *file, unsigned int cmd, unsigned long arg);
  static void ppp_xmit_process(struct ppp *ppp);
  static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
  static void ppp_push(struct ppp *ppp);
  static void ppp_channel_push(struct channel *pch);
  static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
  			      struct channel *pch);
  static void ppp_receive_error(struct ppp *ppp);
  static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
  static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
  					    struct sk_buff *skb);
  #ifdef CONFIG_PPP_MULTILINK
  static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
  				struct channel *pch);
  static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
  static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
  static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
  #endif /* CONFIG_PPP_MULTILINK */
  static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
  static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
  static void ppp_ccp_closed(struct ppp *ppp);
  static struct compressor *find_compressor(int type);
  static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
  static struct ppp *ppp_create_interface(struct net *net, int unit, int *retp);
  static void init_ppp_file(struct ppp_file *pf, int kind);
  static void ppp_shutdown_interface(struct ppp *ppp);
  static void ppp_destroy_interface(struct ppp *ppp);
  static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit);
  static struct channel *ppp_find_channel(struct ppp_net *pn, int unit);
  static int ppp_connect_channel(struct channel *pch, int unit);
  static int ppp_disconnect_channel(struct channel *pch);
  static void ppp_destroy_channel(struct channel *pch);
  static int unit_get(struct idr *p, void *ptr);
  static int unit_set(struct idr *p, void *ptr, int n);
  static void unit_put(struct idr *p, int n);
  static void *unit_find(struct idr *p, int n);
  
  static struct class *ppp_class;
  
  /* per net-namespace data */
  static inline struct ppp_net *ppp_pernet(struct net *net)
  {
  	BUG_ON(!net);
  
  	return net_generic(net, ppp_net_id);
  }
  
  /* Translates a PPP protocol number to a NP index (NP == network protocol) */
  static inline int proto_to_npindex(int proto)
  {
  	switch (proto) {
  	case PPP_IP:
  		return NP_IP;
  	case PPP_IPV6:
  		return NP_IPV6;
  	case PPP_IPX:
  		return NP_IPX;
  	case PPP_AT:
  		return NP_AT;
  	case PPP_MPLS_UC:
  		return NP_MPLS_UC;
  	case PPP_MPLS_MC:
  		return NP_MPLS_MC;
  	}
  	return -EINVAL;
  }
  
  /* Translates an NP index into a PPP protocol number */
  static const int npindex_to_proto[NUM_NP] = {
  	PPP_IP,
  	PPP_IPV6,
  	PPP_IPX,
  	PPP_AT,
  	PPP_MPLS_UC,
  	PPP_MPLS_MC,
  };
  
  /* Translates an ethertype into an NP index */
  static inline int ethertype_to_npindex(int ethertype)
  {
  	switch (ethertype) {
  	case ETH_P_IP:
  		return NP_IP;
  	case ETH_P_IPV6:
  		return NP_IPV6;
  	case ETH_P_IPX:
  		return NP_IPX;
  	case ETH_P_PPPTALK:
  	case ETH_P_ATALK:
  		return NP_AT;
  	case ETH_P_MPLS_UC:
  		return NP_MPLS_UC;
  	case ETH_P_MPLS_MC:
  		return NP_MPLS_MC;
  	}
  	return -1;
  }
  
  /* Translates an NP index into an ethertype */
  static const int npindex_to_ethertype[NUM_NP] = {
  	ETH_P_IP,
  	ETH_P_IPV6,
  	ETH_P_IPX,
  	ETH_P_PPPTALK,
  	ETH_P_MPLS_UC,
  	ETH_P_MPLS_MC,
  };
  
  /*
   * Locking shorthand.
   */
  #define ppp_xmit_lock(ppp)	spin_lock_bh(&(ppp)->wlock)
  #define ppp_xmit_unlock(ppp)	spin_unlock_bh(&(ppp)->wlock)
  #define ppp_recv_lock(ppp)	spin_lock_bh(&(ppp)->rlock)
  #define ppp_recv_unlock(ppp)	spin_unlock_bh(&(ppp)->rlock)
  #define ppp_lock(ppp)		do { ppp_xmit_lock(ppp); \
  				     ppp_recv_lock(ppp); } while (0)
  #define ppp_unlock(ppp)		do { ppp_recv_unlock(ppp); \
  				     ppp_xmit_unlock(ppp); } while (0)
  
  /*
   * /dev/ppp device routines.
   * The /dev/ppp device is used by pppd to control the ppp unit.
   * It supports the read, write, ioctl and poll functions.
   * Open instances of /dev/ppp can be in one of three states:
   * unattached, attached to a ppp unit, or attached to a ppp channel.
   */
  static int ppp_open(struct inode *inode, struct file *file)
  {
  	/*
  	 * This could (should?) be enforced by the permissions on /dev/ppp.
  	 */
  	if (!capable(CAP_NET_ADMIN))
  		return -EPERM;
  	return 0;
  }
  
  static int ppp_release(struct inode *unused, struct file *file)
  {
  	struct ppp_file *pf = file->private_data;
  	struct ppp *ppp;
  
  	if (pf) {
  		file->private_data = NULL;
  		if (pf->kind == INTERFACE) {
  			ppp = PF_TO_PPP(pf);
  			if (file == ppp->owner)
  				ppp_shutdown_interface(ppp);
  		}
  		if (atomic_dec_and_test(&pf->refcnt)) {
  			switch (pf->kind) {
  			case INTERFACE:
  				ppp_destroy_interface(PF_TO_PPP(pf));
  				break;
  			case CHANNEL:
  				ppp_destroy_channel(PF_TO_CHANNEL(pf));
  				break;
  			}
  		}
  	}
  	return 0;
  }
  
  static ssize_t ppp_read(struct file *file, char __user *buf,
  			size_t count, loff_t *ppos)
  {
  	struct ppp_file *pf = file->private_data;
  	DECLARE_WAITQUEUE(wait, current);
  	ssize_t ret;
  	struct sk_buff *skb = NULL;
  	struct iovec iov;
  
  	ret = count;
  
  	if (!pf)
  		return -ENXIO;
  	add_wait_queue(&pf->rwait, &wait);
  	for (;;) {
  		set_current_state(TASK_INTERRUPTIBLE);
  		skb = skb_dequeue(&pf->rq);
  		if (skb)
  			break;
  		ret = 0;
  		if (pf->dead)
  			break;
  		if (pf->kind == INTERFACE) {
  			/*
  			 * Return 0 (EOF) on an interface that has no
  			 * channels connected, unless it is looping
  			 * network traffic (demand mode).
  			 */
  			struct ppp *ppp = PF_TO_PPP(pf);
  			if (ppp->n_channels == 0 &&
  			    (ppp->flags & SC_LOOP_TRAFFIC) == 0)
  				break;
  		}
  		ret = -EAGAIN;
  		if (file->f_flags & O_NONBLOCK)
  			break;
  		ret = -ERESTARTSYS;
  		if (signal_pending(current))
  			break;
  		schedule();
  	}
  	set_current_state(TASK_RUNNING);
  	remove_wait_queue(&pf->rwait, &wait);
  
  	if (!skb)
  		goto out;
  
  	ret = -EOVERFLOW;
  	if (skb->len > count)
  		goto outf;
  	ret = -EFAULT;
  	iov.iov_base = buf;
  	iov.iov_len = count;
  	if (skb_copy_datagram_iovec(skb, 0, &iov, skb->len))
  		goto outf;
  	ret = skb->len;
  
   outf:
  	kfree_skb(skb);
   out:
  	return ret;
  }
  
  static ssize_t ppp_write(struct file *file, const char __user *buf,
  			 size_t count, loff_t *ppos)
  {
  	struct ppp_file *pf = file->private_data;
  	struct sk_buff *skb;
  	ssize_t ret;
  
  	if (!pf)
  		return -ENXIO;
  	ret = -ENOMEM;
  	skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
  	if (!skb)
  		goto out;
  	skb_reserve(skb, pf->hdrlen);
  	ret = -EFAULT;
  	if (copy_from_user(skb_put(skb, count), buf, count)) {
  		kfree_skb(skb);
  		goto out;
  	}
  
  	skb_queue_tail(&pf->xq, skb);
  
  	switch (pf->kind) {
  	case INTERFACE:
  		ppp_xmit_process(PF_TO_PPP(pf));
  		break;
  	case CHANNEL:
  		ppp_channel_push(PF_TO_CHANNEL(pf));
  		break;
  	}
  
  	ret = count;
  
   out:
  	return ret;
  }
  
  /* No kernel lock - fine */
  static unsigned int ppp_poll(struct file *file, poll_table *wait)
  {
  	struct ppp_file *pf = file->private_data;
  	unsigned int mask;
  
  	if (!pf)
  		return 0;
  	poll_wait(file, &pf->rwait, wait);
  	mask = POLLOUT | POLLWRNORM;
  	if (skb_peek(&pf->rq))
  		mask |= POLLIN | POLLRDNORM;
  	if (pf->dead)
  		mask |= POLLHUP;
  	else if (pf->kind == INTERFACE) {
  		/* see comment in ppp_read */
  		struct ppp *ppp = PF_TO_PPP(pf);
  		if (ppp->n_channels == 0 &&
  		    (ppp->flags & SC_LOOP_TRAFFIC) == 0)
  			mask |= POLLIN | POLLRDNORM;
  	}
  
  	return mask;
  }
  
  #ifdef CONFIG_PPP_FILTER
  static int get_filter(void __user *arg, struct sock_filter **p)
  {
  	struct sock_fprog uprog;
  	struct sock_filter *code = NULL;
  	int len, err;
  
  	if (copy_from_user(&uprog, arg, sizeof(uprog)))
  		return -EFAULT;
  
  	if (!uprog.len) {
  		*p = NULL;
  		return 0;
  	}
  
  	len = uprog.len * sizeof(struct sock_filter);
  	code = memdup_user(uprog.filter, len);
  	if (IS_ERR(code))
  		return PTR_ERR(code);
  
  	err = sk_chk_filter(code, uprog.len);
  	if (err) {
  		kfree(code);
  		return err;
  	}
  
  	*p = code;
  	return uprog.len;
  }
  #endif /* CONFIG_PPP_FILTER */
  
  static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
  {
  	struct ppp_file *pf = file->private_data;
  	struct ppp *ppp;
  	int err = -EFAULT, val, val2, i;
  	struct ppp_idle idle;
  	struct npioctl npi;
  	int unit, cflags;
  	struct slcompress *vj;
  	void __user *argp = (void __user *)arg;
  	int __user *p = argp;
  
  	if (!pf)
  		return ppp_unattached_ioctl(current->nsproxy->net_ns,
  					pf, file, cmd, arg);
  
  	if (cmd == PPPIOCDETACH) {
  		/*
  		 * We have to be careful here... if the file descriptor
  		 * has been dup'd, we could have another process in the
  		 * middle of a poll using the same file *, so we had
  		 * better not free the interface data structures -
  		 * instead we fail the ioctl.  Even in this case, we
  		 * shut down the interface if we are the owner of it.
  		 * Actually, we should get rid of PPPIOCDETACH, userland
  		 * (i.e. pppd) could achieve the same effect by closing
  		 * this fd and reopening /dev/ppp.
  		 */
  		err = -EINVAL;
  		mutex_lock(&ppp_mutex);
  		if (pf->kind == INTERFACE) {
  			ppp = PF_TO_PPP(pf);
  			if (file == ppp->owner)
  				ppp_shutdown_interface(ppp);
  		}
  		if (atomic_long_read(&file->f_count) <= 2) {
  			ppp_release(NULL, file);
  			err = 0;
  		} else
  			printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%ld\n",
  			       atomic_long_read(&file->f_count));
  		mutex_unlock(&ppp_mutex);
  		return err;
  	}
  
  	if (pf->kind == CHANNEL) {
  		struct channel *pch;
  		struct ppp_channel *chan;
  
  		mutex_lock(&ppp_mutex);
  		pch = PF_TO_CHANNEL(pf);
  
  		switch (cmd) {
  		case PPPIOCCONNECT:
  			if (get_user(unit, p))
  				break;
  			err = ppp_connect_channel(pch, unit);
  			break;
  
  		case PPPIOCDISCONN:
  			err = ppp_disconnect_channel(pch);
  			break;
  
  		default:
  			down_read(&pch->chan_sem);
  			chan = pch->chan;
  			err = -ENOTTY;
  			if (chan && chan->ops->ioctl)
  				err = chan->ops->ioctl(chan, cmd, arg);
  			up_read(&pch->chan_sem);
  		}
  		mutex_unlock(&ppp_mutex);
  		return err;
  	}
  
  	if (pf->kind != INTERFACE) {
  		/* can't happen */
  		printk(KERN_ERR "PPP: not interface or channel??\n");
  		return -EINVAL;
  	}
  
  	mutex_lock(&ppp_mutex);
  	ppp = PF_TO_PPP(pf);
  	switch (cmd) {
  	case PPPIOCSMRU:
  		if (get_user(val, p))
  			break;
  		ppp->mru = val;
  		err = 0;
  		break;
  
  	case PPPIOCSFLAGS:
  		if (get_user(val, p))
  			break;
  		ppp_lock(ppp);
  		cflags = ppp->flags & ~val;
  		ppp->flags = val & SC_FLAG_BITS;
  		ppp_unlock(ppp);
  		if (cflags & SC_CCP_OPEN)
  			ppp_ccp_closed(ppp);
  		err = 0;
  		break;
  
  	case PPPIOCGFLAGS:
  		val = ppp->flags | ppp->xstate | ppp->rstate;
  		if (put_user(val, p))
  			break;
  		err = 0;
  		break;
  
  	case PPPIOCSCOMPRESS:
  		err = ppp_set_compress(ppp, arg);
  		break;
  
  	case PPPIOCGUNIT:
  		if (put_user(ppp->file.index, p))
  			break;
  		err = 0;
  		break;
  
  	case PPPIOCSDEBUG:
  		if (get_user(val, p))
  			break;
  		ppp->debug = val;
  		err = 0;
  		break;
  
  	case PPPIOCGDEBUG:
  		if (put_user(ppp->debug, p))
  			break;
  		err = 0;
  		break;
  
  	case PPPIOCGIDLE:
  		idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
  		idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
  		if (copy_to_user(argp, &idle, sizeof(idle)))
  			break;
  		err = 0;
  		break;
  
  	case PPPIOCSMAXCID:
  		if (get_user(val, p))
  			break;
  		val2 = 15;
  		if ((val >> 16) != 0) {
  			val2 = val >> 16;
  			val &= 0xffff;
  		}
  		vj = slhc_init(val2+1, val+1);
  		if (!vj) {
  			printk(KERN_ERR "PPP: no memory (VJ compressor)\n");
  			err = -ENOMEM;
  			break;
  		}
  		ppp_lock(ppp);
  		if (ppp->vj)
  			slhc_free(ppp->vj);
  		ppp->vj = vj;
  		ppp_unlock(ppp);
  		err = 0;
  		break;
  
  	case PPPIOCGNPMODE:
  	case PPPIOCSNPMODE:
  		if (copy_from_user(&npi, argp, sizeof(npi)))
  			break;
  		err = proto_to_npindex(npi.protocol);
  		if (err < 0)
  			break;
  		i = err;
  		if (cmd == PPPIOCGNPMODE) {
  			err = -EFAULT;
  			npi.mode = ppp->npmode[i];
  			if (copy_to_user(argp, &npi, sizeof(npi)))
  				break;
  		} else {
  			ppp->npmode[i] = npi.mode;
  			/* we may be able to transmit more packets now (??) */
  			netif_wake_queue(ppp->dev);
  		}
  		err = 0;
  		break;
  
  #ifdef CONFIG_PPP_FILTER
  	case PPPIOCSPASS:
  	{
  		struct sock_filter *code;
  		err = get_filter(argp, &code);
  		if (err >= 0) {
  			ppp_lock(ppp);
  			kfree(ppp->pass_filter);
  			ppp->pass_filter = code;
  			ppp->pass_len = err;
  			ppp_unlock(ppp);
  			err = 0;
  		}
  		break;
  	}
  	case PPPIOCSACTIVE:
  	{
  		struct sock_filter *code;
  		err = get_filter(argp, &code);
  		if (err >= 0) {
  			ppp_lock(ppp);
  			kfree(ppp->active_filter);
  			ppp->active_filter = code;
  			ppp->active_len = err;
  			ppp_unlock(ppp);
  			err = 0;
  		}
  		break;
  	}
  #endif /* CONFIG_PPP_FILTER */
  
  #ifdef CONFIG_PPP_MULTILINK
  	case PPPIOCSMRRU:
  		if (get_user(val, p))
  			break;
  		ppp_recv_lock(ppp);
  		ppp->mrru = val;
  		ppp_recv_unlock(ppp);
  		err = 0;
  		break;
  #endif /* CONFIG_PPP_MULTILINK */
  
  	default:
  		err = -ENOTTY;
  	}
  	mutex_unlock(&ppp_mutex);
  	return err;
  }
  
  static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
  			struct file *file, unsigned int cmd, unsigned long arg)
  {
  	int unit, err = -EFAULT;
  	struct ppp *ppp;
  	struct channel *chan;
  	struct ppp_net *pn;
  	int __user *p = (int __user *)arg;
  
  	mutex_lock(&ppp_mutex);
  	switch (cmd) {
  	case PPPIOCNEWUNIT:
  		/* Create a new ppp unit */
  		if (get_user(unit, p))
  			break;
  		ppp = ppp_create_interface(net, unit, &err);
  		if (!ppp)
  			break;
  		file->private_data = &ppp->file;
  		ppp->owner = file;
  		err = -EFAULT;
  		if (put_user(ppp->file.index, p))
  			break;
  		err = 0;
  		break;
  
  	case PPPIOCATTACH:
  		/* Attach to an existing ppp unit */
  		if (get_user(unit, p))
  			break;
  		err = -ENXIO;
  		pn = ppp_pernet(net);
  		mutex_lock(&pn->all_ppp_mutex);
  		ppp = ppp_find_unit(pn, unit);
  		if (ppp) {
  			atomic_inc(&ppp->file.refcnt);
  			file->private_data = &ppp->file;
  			err = 0;
  		}
  		mutex_unlock(&pn->all_ppp_mutex);
  		break;
  
  	case PPPIOCATTCHAN:
  		if (get_user(unit, p))
  			break;
  		err = -ENXIO;
  		pn = ppp_pernet(net);
  		spin_lock_bh(&pn->all_channels_lock);
  		chan = ppp_find_channel(pn, unit);
  		if (chan) {
  			atomic_inc(&chan->file.refcnt);
  			file->private_data = &chan->file;
  			err = 0;
  		}
  		spin_unlock_bh(&pn->all_channels_lock);
  		break;
  
  	default:
  		err = -ENOTTY;
  	}
  	mutex_unlock(&ppp_mutex);
  	return err;
  }
  
  static const struct file_operations ppp_device_fops = {
  	.owner		= THIS_MODULE,
  	.read		= ppp_read,
  	.write		= ppp_write,
  	.poll		= ppp_poll,
  	.unlocked_ioctl	= ppp_ioctl,
  	.open		= ppp_open,
  	.release	= ppp_release
  };
  
  static __net_init int ppp_init_net(struct net *net)
  {
  	struct ppp_net *pn = net_generic(net, ppp_net_id);
  
  	idr_init(&pn->units_idr);
  	mutex_init(&pn->all_ppp_mutex);
  
  	INIT_LIST_HEAD(&pn->all_channels);
  	INIT_LIST_HEAD(&pn->new_channels);
  
  	spin_lock_init(&pn->all_channels_lock);
  
  	return 0;
  }
  
  static __net_exit void ppp_exit_net(struct net *net)
  {
  	struct ppp_net *pn = net_generic(net, ppp_net_id);
  
  	idr_destroy(&pn->units_idr);
  }
  
  static struct pernet_operations ppp_net_ops = {
  	.init = ppp_init_net,
  	.exit = ppp_exit_net,
  	.id   = &ppp_net_id,
  	.size = sizeof(struct ppp_net),
  };
  
  #define PPP_MAJOR	108
  
  /* Called at boot time if ppp is compiled into the kernel,
     or at module load time (from init_module) if compiled as a module. */
  static int __init ppp_init(void)
  {
  	int err;
  
  	printk(KERN_INFO "PPP generic driver version " PPP_VERSION "\n");
  
  	err = register_pernet_device(&ppp_net_ops);
  	if (err) {
  		printk(KERN_ERR "failed to register PPP pernet device (%d)\n", err);
  		goto out;
  	}
  
  	err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
  	if (err) {
  		printk(KERN_ERR "failed to register PPP device (%d)\n", err);
  		goto out_net;
  	}
  
  	ppp_class = class_create(THIS_MODULE, "ppp");
  	if (IS_ERR(ppp_class)) {
  		err = PTR_ERR(ppp_class);
  		goto out_chrdev;
  	}
  
  	/* not a big deal if we fail here :-) */
  	device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
  
  	return 0;
  
  out_chrdev:
  	unregister_chrdev(PPP_MAJOR, "ppp");
  out_net:
  	unregister_pernet_device(&ppp_net_ops);
  out:
  	return err;
  }
  
  /*
   * Network interface unit routines.
   */
  static netdev_tx_t
  ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
  {
  	struct ppp *ppp = netdev_priv(dev);
  	int npi, proto;
  	unsigned char *pp;
  
  	npi = ethertype_to_npindex(ntohs(skb->protocol));
  	if (npi < 0)
  		goto outf;
  
  	/* Drop, accept or reject the packet */
  	switch (ppp->npmode[npi]) {
  	case NPMODE_PASS:
  		break;
  	case NPMODE_QUEUE:
  		/* it would be nice to have a way to tell the network
  		   system to queue this one up for later. */
  		goto outf;
  	case NPMODE_DROP:
  	case NPMODE_ERROR:
  		goto outf;
  	}
  
  	/* Put the 2-byte PPP protocol number on the front,
  	   making sure there is room for the address and control fields. */
  	if (skb_cow_head(skb, PPP_HDRLEN)) {
  		goto outf;
  	}
  
  	pp = skb_push(skb, 2);
  	proto = npindex_to_proto[npi];
  	pp[0] = proto >> 8;
  	pp[1] = proto;
  
  	skb_queue_tail(&ppp->file.xq, skb);
  	ppp_xmit_process(ppp);
  	return NETDEV_TX_OK;
  
   outf:
  	kfree_skb(skb);
  	++dev->stats.tx_dropped;
  	return NETDEV_TX_OK;
  }
  
  static int
  ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
  {
  	struct ppp *ppp = netdev_priv(dev);
  	int err = -EFAULT;
  	void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
  	struct ppp_stats stats;
  	struct ppp_comp_stats cstats;
  	char *vers;
  
  	switch (cmd) {
  	case SIOCGPPPSTATS:
  		ppp_get_stats(ppp, &stats);
  		if (copy_to_user(addr, &stats, sizeof(stats)))
  			break;
  		err = 0;
  		break;
  
  	case SIOCGPPPCSTATS:
  		memset(&cstats, 0, sizeof(cstats));
  		if (ppp->xc_state)
  			ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
  		if (ppp->rc_state)
  			ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
  		if (copy_to_user(addr, &cstats, sizeof(cstats)))
  			break;
  		err = 0;
  		break;
  
  	case SIOCGPPPVER:
  		vers = PPP_VERSION;
  		if (copy_to_user(addr, vers, strlen(vers) + 1))
  			break;
  		err = 0;
  		break;
  
  	default:
  		err = -EINVAL;
  	}
  
  	return err;
  }
  
  static const struct net_device_ops ppp_netdev_ops = {
  	.ndo_start_xmit = ppp_start_xmit,
  	.ndo_do_ioctl   = ppp_net_ioctl,
  };
  
  static void ppp_setup(struct net_device *dev)
  {
  	dev->netdev_ops = &ppp_netdev_ops;
  	dev->hard_header_len = PPP_HDRLEN;
  	dev->mtu = PPP_MTU;
  	dev->addr_len = 0;
  	dev->tx_queue_len = 3;
  	dev->type = ARPHRD_PPP;
  	dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
  	dev->features |= NETIF_F_NETNS_LOCAL;
  	dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
  }
  
  /*
   * Transmit-side routines.
   */
  
  /*
   * Called to do any work queued up on the transmit side
   * that can now be done.
   */
  static void
  ppp_xmit_process(struct ppp *ppp)
  {
  	struct sk_buff *skb;
  
  	ppp_xmit_lock(ppp);
  	if (!ppp->closing) {
  		ppp_push(ppp);
  		while (!ppp->xmit_pending &&
  		       (skb = skb_dequeue(&ppp->file.xq)))
  			ppp_send_frame(ppp, skb);
  		/* If there's no work left to do, tell the core net
  		   code that we can accept some more. */
  		if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
  			netif_wake_queue(ppp->dev);
  		else
  			netif_stop_queue(ppp->dev);
  	}
  	ppp_xmit_unlock(ppp);
  }
  
  static inline struct sk_buff *
  pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
  {
  	struct sk_buff *new_skb;
  	int len;
  	int new_skb_size = ppp->dev->mtu +
  		ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
  	int compressor_skb_size = ppp->dev->mtu +
  		ppp->xcomp->comp_extra + PPP_HDRLEN;
  	new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
  	if (!new_skb) {
  		if (net_ratelimit())
  			printk(KERN_ERR "PPP: no memory (comp pkt)\n");
  		return NULL;
  	}
  	if (ppp->dev->hard_header_len > PPP_HDRLEN)
  		skb_reserve(new_skb,
  			    ppp->dev->hard_header_len - PPP_HDRLEN);
  
  	/* compressor still expects A/C bytes in hdr */
  	len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
  				   new_skb->data, skb->len + 2,
  				   compressor_skb_size);
  	if (len > 0 && (ppp->flags & SC_CCP_UP)) {
  		kfree_skb(skb);
  		skb = new_skb;
  		skb_put(skb, len);
  		skb_pull(skb, 2);	/* pull off A/C bytes */
  	} else if (len == 0) {
  		/* didn't compress, or CCP not up yet */
  		kfree_skb(new_skb);
  		new_skb = skb;
  	} else {
  		/*
  		 * (len < 0)
  		 * MPPE requires that we do not send unencrypted
  		 * frames.  The compressor will return -1 if we
  		 * should drop the frame.  We cannot simply test
  		 * the compress_proto because MPPE and MPPC share
  		 * the same number.
  		 */
  		if (net_ratelimit())
  			printk(KERN_ERR "ppp: compressor dropped pkt\n");
  		kfree_skb(skb);
  		kfree_skb(new_skb);
  		new_skb = NULL;
  	}
  	return new_skb;
  }
  
  /*
   * Compress and send a frame.
   * The caller should have locked the xmit path,
   * and xmit_pending should be 0.
   */
  static void
  ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
  {
  	int proto = PPP_PROTO(skb);
  	struct sk_buff *new_skb;
  	int len;
  	unsigned char *cp;
  
  	if (proto < 0x8000) {
  #ifdef CONFIG_PPP_FILTER
  		/* check if we should pass this packet */
  		/* the filter instructions are constructed assuming
  		   a four-byte PPP header on each packet */
  		*skb_push(skb, 2) = 1;
  		if (ppp->pass_filter &&
  		    sk_run_filter(skb, ppp->pass_filter,
  				  ppp->pass_len) == 0) {
  			if (ppp->debug & 1)
  				printk(KERN_DEBUG "PPP: outbound frame not passed\n");
  			kfree_skb(skb);
  			return;
  		}
  		/* if this packet passes the active filter, record the time */
  		if (!(ppp->active_filter &&
  		      sk_run_filter(skb, ppp->active_filter,
  				    ppp->active_len) == 0))
  			ppp->last_xmit = jiffies;
  		skb_pull(skb, 2);
  #else
  		/* for data packets, record the time */
  		ppp->last_xmit = jiffies;
  #endif /* CONFIG_PPP_FILTER */
  	}
  
  	++ppp->dev->stats.tx_packets;
  	ppp->dev->stats.tx_bytes += skb->len - 2;
  
  	switch (proto) {
  	case PPP_IP:
  		if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
  			break;
  		/* try to do VJ TCP header compression */
  		new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
  				    GFP_ATOMIC);
  		if (!new_skb) {
  			printk(KERN_ERR "PPP: no memory (VJ comp pkt)\n");
  			goto drop;
  		}
  		skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
  		cp = skb->data + 2;
  		len = slhc_compress(ppp->vj, cp, skb->len - 2,
  				    new_skb->data + 2, &cp,
  				    !(ppp->flags & SC_NO_TCP_CCID));
  		if (cp == skb->data + 2) {
  			/* didn't compress */
  			kfree_skb(new_skb);
  		} else {
  			if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
  				proto = PPP_VJC_COMP;
  				cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
  			} else {
  				proto = PPP_VJC_UNCOMP;
  				cp[0] = skb->data[2];
  			}
  			kfree_skb(skb);
  			skb = new_skb;
  			cp = skb_put(skb, len + 2);
  			cp[0] = 0;
  			cp[1] = proto;
  		}
  		break;
  
  	case PPP_CCP:
  		/* peek at outbound CCP frames */
  		ppp_ccp_peek(ppp, skb, 0);
  		break;
  	}
  
  	/* try to do packet compression */
  	if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state &&
  	    proto != PPP_LCP && proto != PPP_CCP) {
  		if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
  			if (net_ratelimit())
  				printk(KERN_ERR "ppp: compression required but down - pkt dropped.\n");
  			goto drop;
  		}
  		skb = pad_compress_skb(ppp, skb);
  		if (!skb)
  			goto drop;
  	}
  
  	/*
  	 * If we are waiting for traffic (demand dialling),
  	 * queue it up for pppd to receive.
  	 */
  	if (ppp->flags & SC_LOOP_TRAFFIC) {
  		if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
  			goto drop;
  		skb_queue_tail(&ppp->file.rq, skb);
  		wake_up_interruptible(&ppp->file.rwait);
  		return;
  	}
  
  	ppp->xmit_pending = skb;
  	ppp_push(ppp);
  	return;
  
   drop:
  	kfree_skb(skb);
  	++ppp->dev->stats.tx_errors;
  }
  
  /*
   * Try to send the frame in xmit_pending.
   * The caller should have the xmit path locked.
   */
  static void
  ppp_push(struct ppp *ppp)
  {
  	struct list_head *list;
  	struct channel *pch;
  	struct sk_buff *skb = ppp->xmit_pending;
  
  	if (!skb)
  		return;
  
  	list = &ppp->channels;
  	if (list_empty(list)) {
  		/* nowhere to send the packet, just drop it */
  		ppp->xmit_pending = NULL;
  		kfree_skb(skb);
  		return;
  	}
  
  	if ((ppp->flags & SC_MULTILINK) == 0) {
  		/* not doing multilink: send it down the first channel */
  		list = list->next;
  		pch = list_entry(list, struct channel, clist);
  
  		spin_lock_bh(&pch->downl);
  		if (pch->chan) {
  			if (pch->chan->ops->start_xmit(pch->chan, skb))
  				ppp->xmit_pending = NULL;
  		} else {
  			/* channel got unregistered */
  			kfree_skb(skb);
  			ppp->xmit_pending = NULL;
  		}
  		spin_unlock_bh(&pch->downl);
  		return;
  	}
  
  #ifdef CONFIG_PPP_MULTILINK
  	/* Multilink: fragment the packet over as many links
  	   as can take the packet at the moment. */
  	if (!ppp_mp_explode(ppp, skb))
  		return;
  #endif /* CONFIG_PPP_MULTILINK */
  
  	ppp->xmit_pending = NULL;
  	kfree_skb(skb);
  }
  
  #ifdef CONFIG_PPP_MULTILINK
  /*
   * Divide a packet to be transmitted into fragments and
   * send them out the individual links.
   */
  static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
  {
  	int len, totlen;
  	int i, bits, hdrlen, mtu;
  	int flen;
  	int navail, nfree, nzero;
  	int nbigger;
  	int totspeed;
  	int totfree;
  	unsigned char *p, *q;
  	struct list_head *list;
  	struct channel *pch;
  	struct sk_buff *frag;
  	struct ppp_channel *chan;
  
  	totspeed = 0; /*total bitrate of the bundle*/
  	nfree = 0; /* # channels which have no packet already queued */
  	navail = 0; /* total # of usable channels (not deregistered) */
  	nzero = 0; /* number of channels with zero speed associated*/
  	totfree = 0; /*total # of channels available and
  				  *having no queued packets before
  				  *starting the fragmentation*/
  
  	hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
  	i = 0;
  	list_for_each_entry(pch, &ppp->channels, clist) {
  		if (pch->chan) {
  			pch->avail = 1;
  			navail++;
  			pch->speed = pch->chan->speed;
  		} else {
  			pch->avail = 0;
  		}
  		if (pch->avail) {
  			if (skb_queue_empty(&pch->file.xq) ||
  				!pch->had_frag) {
  					if (pch->speed == 0)
  						nzero++;
  					else
  						totspeed += pch->speed;
  
  					pch->avail = 2;
  					++nfree;
  					++totfree;
  				}
  			if (!pch->had_frag && i < ppp->nxchan)
  				ppp->nxchan = i;
  		}
  		++i;
  	}
  	/*
  	 * Don't start sending this packet unless at least half of
  	 * the channels are free.  This gives much better TCP
  	 * performance if we have a lot of channels.
  	 */
  	if (nfree == 0 || nfree < navail / 2)
  		return 0; /* can't take now, leave it in xmit_pending */
  
  	p = skb->data;
  	len = skb->len;
  	if (*p == 0) {
  		++p;
  		--len;
  	}
  
  	totlen = len;
  	nbigger = len % nfree;
  
  	/* skip to the channel after the one we last used
  	   and start at that one */
  	list = &ppp->channels;
  	for (i = 0; i < ppp->nxchan; ++i) {
  		list = list->next;
  		if (list == &ppp->channels) {
  			i = 0;
  			break;
  		}
  	}
  
  	/* create a fragment for each channel */
  	bits = B;
  	while (len > 0) {
  		list = list->next;
  		if (list == &ppp->channels) {
  			i = 0;
  			continue;
  		}
  		pch = list_entry(list, struct channel, clist);
  		++i;
  		if (!pch->avail)
  			continue;
  
  		/*
  		 * Skip this channel if it has a fragment pending already and
  		 * we haven't given a fragment to all of the free channels.
  		 */
  		if (pch->avail == 1) {
  			if (nfree > 0)
  				continue;
  		} else {
  			pch->avail = 1;
  		}
  
  		/* check the channel's mtu and whether it is still attached. */
  		spin_lock_bh(&pch->downl);
  		if (pch->chan == NULL) {
  			/* can't use this channel, it's being deregistered */
  			if (pch->speed == 0)
  				nzero--;
  			else
  				totspeed -= pch->speed;
  
  			spin_unlock_bh(&pch->downl);
  			pch->avail = 0;
  			totlen = len;
  			totfree--;
  			nfree--;
  			if (--navail == 0)
  				break;
  			continue;
  		}
  
  		/*
  		*if the channel speed is not set divide
  		*the packet evenly among the free channels;
  		*otherwise divide it according to the speed
  		*of the channel we are going to transmit on
  		*/
  		flen = len;
  		if (nfree > 0) {
  			if (pch->speed == 0) {
  				flen = len/nfree;
  				if (nbigger > 0) {
  					flen++;
  					nbigger--;
  				}
  			} else {
  				flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
  					((totspeed*totfree)/pch->speed)) - hdrlen;
  				if (nbigger > 0) {
  					flen += ((totfree - nzero)*pch->speed)/totspeed;
  					nbigger -= ((totfree - nzero)*pch->speed)/
  							totspeed;
  				}
  			}
  			nfree--;
  		}
  
  		/*
  		 *check if we are on the last channel or
  		 *we exceded the lenght of the data to
  		 *fragment
  		 */
  		if ((nfree <= 0) || (flen > len))
  			flen = len;
  		/*
  		 *it is not worth to tx on slow channels:
  		 *in that case from the resulting flen according to the
  		 *above formula will be equal or less than zero.
  		 *Skip the channel in this case
  		 */
  		if (flen <= 0) {
  			pch->avail = 2;
  			spin_unlock_bh(&pch->downl);
  			continue;
  		}
  
  		mtu = pch->chan->mtu - hdrlen;
  		if (mtu < 4)
  			mtu = 4;
  		if (flen > mtu)
  			flen = mtu;
  		if (flen == len)
  			bits |= E;
  		frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
  		if (!frag)
  			goto noskb;
  		q = skb_put(frag, flen + hdrlen);
  
  		/* make the MP header */
  		q[0] = PPP_MP >> 8;
  		q[1] = PPP_MP;
  		if (ppp->flags & SC_MP_XSHORTSEQ) {
  			q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
  			q[3] = ppp->nxseq;
  		} else {
  			q[2] = bits;
  			q[3] = ppp->nxseq >> 16;
  			q[4] = ppp->nxseq >> 8;
  			q[5] = ppp->nxseq;
  		}
  
  		memcpy(q + hdrlen, p, flen);
  
  		/* try to send it down the channel */
  		chan = pch->chan;
  		if (!skb_queue_empty(&pch->file.xq) ||
  			!chan->ops->start_xmit(chan, frag))
  			skb_queue_tail(&pch->file.xq, frag);
  		pch->had_frag = 1;
  		p += flen;
  		len -= flen;
  		++ppp->nxseq;
  		bits = 0;
  		spin_unlock_bh(&pch->downl);
  	}
  	ppp->nxchan = i;
  
  	return 1;
  
   noskb:
  	spin_unlock_bh(&pch->downl);
  	if (ppp->debug & 1)
  		printk(KERN_ERR "PPP: no memory (fragment)\n");
  	++ppp->dev->stats.tx_errors;
  	++ppp->nxseq;
  	return 1;	/* abandon the frame */
  }
  #endif /* CONFIG_PPP_MULTILINK */
  
  /*
   * Try to send data out on a channel.
   */
  static void
  ppp_channel_push(struct channel *pch)
  {
  	struct sk_buff *skb;
  	struct ppp *ppp;
  
  	spin_lock_bh(&pch->downl);
  	if (pch->chan) {
  		while (!skb_queue_empty(&pch->file.xq)) {
  			skb = skb_dequeue(&pch->file.xq);
  			if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
  				/* put the packet back and try again later */
  				skb_queue_head(&pch->file.xq, skb);
  				break;
  			}
  		}
  	} else {
  		/* channel got deregistered */
  		skb_queue_purge(&pch->file.xq);
  	}
  	spin_unlock_bh(&pch->downl);
  	/* see if there is anything from the attached unit to be sent */
  	if (skb_queue_empty(&pch->file.xq)) {
  		read_lock_bh(&pch->upl);
  		ppp = pch->ppp;
  		if (ppp)
  			ppp_xmit_process(ppp);
  		read_unlock_bh(&pch->upl);
  	}
  }
  
  /*
   * Receive-side routines.
   */
  
  /* misuse a few fields of the skb for MP reconstruction */
  #define sequence	priority
  #define BEbits		cb[0]
  
  static inline void
  ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
  {
  	ppp_recv_lock(ppp);
  	if (!ppp->closing)
  		ppp_receive_frame(ppp, skb, pch);
  	else
  		kfree_skb(skb);
  	ppp_recv_unlock(ppp);
  }
  
  void
  ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
  {
  	struct channel *pch = chan->ppp;
  	int proto;
  
  	if (!pch) {
  		kfree_skb(skb);
  		return;
  	}
  
  	read_lock_bh(&pch->upl);
  	if (!pskb_may_pull(skb, 2)) {
  		kfree_skb(skb);
  		if (pch->ppp) {
  			++pch->ppp->dev->stats.rx_length_errors;
  			ppp_receive_error(pch->ppp);
  		}
  		goto done;
  	}
  
  	proto = PPP_PROTO(skb);
  	if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
  		/* put it on the channel queue */
  		skb_queue_tail(&pch->file.rq, skb);
  		/* drop old frames if queue too long */
  		while (pch->file.rq.qlen > PPP_MAX_RQLEN &&
  		       (skb = skb_dequeue(&pch->file.rq)))
  			kfree_skb(skb);
  		wake_up_interruptible(&pch->file.rwait);
  	} else {
  		ppp_do_recv(pch->ppp, skb, pch);
  	}
  
  done:
  	read_unlock_bh(&pch->upl);
  }
  
  /* Put a 0-length skb in the receive queue as an error indication */
  void
  ppp_input_error(struct ppp_channel *chan, int code)
  {
  	struct channel *pch = chan->ppp;
  	struct sk_buff *skb;
  
  	if (!pch)
  		return;
  
  	read_lock_bh(&pch->upl);
  	if (pch->ppp) {
  		skb = alloc_skb(0, GFP_ATOMIC);
  		if (skb) {
  			skb->len = 0;		/* probably unnecessary */
  			skb->cb[0] = code;
  			ppp_do_recv(pch->ppp, skb, pch);
  		}
  	}
  	read_unlock_bh(&pch->upl);
  }
  
  /*
   * We come in here to process a received frame.
   * The receive side of the ppp unit is locked.
   */
  static void
  ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
  {
  	/* note: a 0-length skb is used as an error indication */
  	if (skb->len > 0) {
  #ifdef CONFIG_PPP_MULTILINK
  		if (PPP_PROTO(skb) == PPP_MP)
  			ppp_receive_mp_frame(ppp, skb, pch);
  		else
  #endif /* CONFIG_PPP_MULTILINK */
  			ppp_receive_nonmp_frame(ppp, skb);
  	} else {
  		kfree_skb(skb);
  		ppp_receive_error(ppp);
  	}
  }
  
  static void
  ppp_receive_error(struct ppp *ppp)
  {
  	++ppp->dev->stats.rx_errors;
  	if (ppp->vj)
  		slhc_toss(ppp->vj);
  }
  
  static void
  ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
  {
  	struct sk_buff *ns;
  	int proto, len, npi;
  
  	/*
  	 * Decompress the frame, if compressed.
  	 * Note that some decompressors need to see uncompressed frames
  	 * that come in as well as compressed frames.
  	 */
  	if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) &&
  	    (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
  		skb = ppp_decompress_frame(ppp, skb);
  
  	if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
  		goto err;
  
  	proto = PPP_PROTO(skb);
  	switch (proto) {
  	case PPP_VJC_COMP:
  		/* decompress VJ compressed packets */
  		if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
  			goto err;
  
  		if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
  			/* copy to a new sk_buff with more tailroom */
  			ns = dev_alloc_skb(skb->len + 128);
  			if (!ns) {
  				printk(KERN_ERR"PPP: no memory (VJ decomp)\n");
  				goto err;
  			}
  			skb_reserve(ns, 2);
  			skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
  			kfree_skb(skb);
  			skb = ns;
  		}
  		else
  			skb->ip_summed = CHECKSUM_NONE;
  
  		len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
  		if (len <= 0) {
  			printk(KERN_DEBUG "PPP: VJ decompression error\n");
  			goto err;
  		}
  		len += 2;
  		if (len > skb->len)
  			skb_put(skb, len - skb->len);
  		else if (len < skb->len)
  			skb_trim(skb, len);
  		proto = PPP_IP;
  		break;
  
  	case PPP_VJC_UNCOMP:
  		if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
  			goto err;
  
  		/* Until we fix the decompressor need to make sure
  		 * data portion is linear.
  		 */
  		if (!pskb_may_pull(skb, skb->len))
  			goto err;
  
  		if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
  			printk(KERN_ERR "PPP: VJ uncompressed error\n");
  			goto err;
  		}
  		proto = PPP_IP;
  		break;
  
  	case PPP_CCP:
  		ppp_ccp_peek(ppp, skb, 1);
  		break;
  	}
  
  	++ppp->dev->stats.rx_packets;
  	ppp->dev->stats.rx_bytes += skb->len - 2;
  
  	npi = proto_to_npindex(proto);
  	if (npi < 0) {
  		/* control or unknown frame - pass it to pppd */
  		skb_queue_tail(&ppp->file.rq, skb);
  		/* limit queue length by dropping old frames */
  		while (ppp->file.rq.qlen > PPP_MAX_RQLEN &&
  		       (skb = skb_dequeue(&ppp->file.rq)))
  			kfree_skb(skb);
  		/* wake up any process polling or blocking on read */
  		wake_up_interruptible(&ppp->file.rwait);
  
  	} else {
  		/* network protocol frame - give it to the kernel */
  
  #ifdef CONFIG_PPP_FILTER
  		/* check if the packet passes the pass and active filters */
  		/* the filter instructions are constructed assuming
  		   a four-byte PPP header on each packet */
  		if (ppp->pass_filter || ppp->active_filter) {
  			if (skb_cloned(skb) &&
  			    pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
  				goto err;
  
  			*skb_push(skb, 2) = 0;
  			if (ppp->pass_filter &&
  			    sk_run_filter(skb, ppp->pass_filter,
  					  ppp->pass_len) == 0) {
  				if (ppp->debug & 1)
  					printk(KERN_DEBUG "PPP: inbound frame "
  					       "not passed\n");
  				kfree_skb(skb);
  				return;
  			}
  			if (!(ppp->active_filter &&
  			      sk_run_filter(skb, ppp->active_filter,
  					    ppp->active_len) == 0))
  				ppp->last_recv = jiffies;
  			__skb_pull(skb, 2);
  		} else
  #endif /* CONFIG_PPP_FILTER */
  			ppp->last_recv = jiffies;
  
  		if ((ppp->dev->flags & IFF_UP) == 0 ||
  		    ppp->npmode[npi] != NPMODE_PASS) {
  			kfree_skb(skb);
  		} else {
  			/* chop off protocol */
  			skb_pull_rcsum(skb, 2);
  			skb->dev = ppp->dev;
  			skb->protocol = htons(npindex_to_ethertype[npi]);
  			skb_reset_mac_header(skb);
  			netif_rx(skb);
  		}
  	}
  	return;
  
   err:
  	kfree_skb(skb);
  	ppp_receive_error(ppp);
  }
  
  static struct sk_buff *
  ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
  {
  	int proto = PPP_PROTO(skb);
  	struct sk_buff *ns;
  	int len;
  
  	/* Until we fix all the decompressor's need to make sure
  	 * data portion is linear.
  	 */
  	if (!pskb_may_pull(skb, skb->len))
  		goto err;
  
  	if (proto == PPP_COMP) {
  		int obuff_size;
  
  		switch(ppp->rcomp->compress_proto) {
  		case CI_MPPE:
  			obuff_size = ppp->mru + PPP_HDRLEN + 1;
  			break;
  		default:
  			obuff_size = ppp->mru + PPP_HDRLEN;
  			break;
  		}
  
  		ns = dev_alloc_skb(obuff_size);
  		if (!ns) {
  			printk(KERN_ERR "ppp_decompress_frame: no memory\n");
  			goto err;
  		}
  		/* the decompressor still expects the A/C bytes in the hdr */
  		len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
  				skb->len + 2, ns->data, obuff_size);
  		if (len < 0) {
  			/* Pass the compressed frame to pppd as an
  			   error indication. */
  			if (len == DECOMP_FATALERROR)
  				ppp->rstate |= SC_DC_FERROR;
  			kfree_skb(ns);
  			goto err;
  		}
  
  		kfree_skb(skb);
  		skb = ns;
  		skb_put(skb, len);
  		skb_pull(skb, 2);	/* pull off the A/C bytes */
  
  	} else {
  		/* Uncompressed frame - pass to decompressor so it
  		   can update its dictionary if necessary. */
  		if (ppp->rcomp->incomp)
  			ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
  					   skb->len + 2);
  	}
  
  	return skb;
  
   err:
  	ppp->rstate |= SC_DC_ERROR;
  	ppp_receive_error(ppp);
  	return skb;
  }
  
  #ifdef CONFIG_PPP_MULTILINK
  /*
   * Receive a multilink frame.
   * We put it on the reconstruction queue and then pull off
   * as many completed frames as we can.
   */
  static void
  ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
  {
  	u32 mask, seq;
  	struct channel *ch;
  	int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
  
  	if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
  		goto err;		/* no good, throw it away */
  
  	/* Decode sequence number and begin/end bits */
  	if (ppp->flags & SC_MP_SHORTSEQ) {
  		seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
  		mask = 0xfff;
  	} else {
  		seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
  		mask = 0xffffff;
  	}
  	skb->BEbits = skb->data[2];
  	skb_pull(skb, mphdrlen);	/* pull off PPP and MP headers */
  
  	/*
  	 * Do protocol ID decompression on the first fragment of each packet.
  	 */
  	if ((skb->BEbits & B) && (skb->data[0] & 1))
  		*skb_push(skb, 1) = 0;
  
  	/*
  	 * Expand sequence number to 32 bits, making it as close
  	 * as possible to ppp->minseq.
  	 */
  	seq |= ppp->minseq & ~mask;
  	if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
  		seq += mask + 1;
  	else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
  		seq -= mask + 1;	/* should never happen */
  	skb->sequence = seq;
  	pch->lastseq = seq;
  
  	/*
  	 * If this packet comes before the next one we were expecting,
  	 * drop it.
  	 */
  	if (seq_before(seq, ppp->nextseq)) {
  		kfree_skb(skb);
  		++ppp->dev->stats.rx_dropped;
  		ppp_receive_error(ppp);
  		return;
  	}
  
  	/*
  	 * Reevaluate minseq, the minimum over all channels of the
  	 * last sequence number received on each channel.  Because of
  	 * the increasing sequence number rule, we know that any fragment
  	 * before `minseq' which hasn't arrived is never going to arrive.
  	 * The list of channels can't change because we have the receive
  	 * side of the ppp unit locked.
  	 */
  	list_for_each_entry(ch, &ppp->channels, clist) {
  		if (seq_before(ch->lastseq, seq))
  			seq = ch->lastseq;
  	}
  	if (seq_before(ppp->minseq, seq))
  		ppp->minseq = seq;
  
  	/* Put the fragment on the reconstruction queue */
  	ppp_mp_insert(ppp, skb);
  
  	/* If the queue is getting long, don't wait any longer for packets
  	   before the start of the queue. */
  	if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
  		struct sk_buff *mskb = skb_peek(&ppp->mrq);
  		if (seq_before(ppp->minseq, mskb->sequence))
  			ppp->minseq = mskb->sequence;
  	}
  
  	/* Pull completed packets off the queue and receive them. */
  	while ((skb = ppp_mp_reconstruct(ppp))) {
  		if (pskb_may_pull(skb, 2))
  			ppp_receive_nonmp_frame(ppp, skb);
  		else {
  			++ppp->dev->stats.rx_length_errors;
  			kfree_skb(skb);
  			ppp_receive_error(ppp);
  		}
  	}
  
  	return;
  
   err:
  	kfree_skb(skb);
  	ppp_receive_error(ppp);
  }
  
  /*
   * Insert a fragment on the MP reconstruction queue.
   * The queue is ordered by increasing sequence number.
   */
  static void
  ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
  {
  	struct sk_buff *p;
  	struct sk_buff_head *list = &ppp->mrq;
  	u32 seq = skb->sequence;
  
  	/* N.B. we don't need to lock the list lock because we have the
  	   ppp unit receive-side lock. */
  	skb_queue_walk(list, p) {
  		if (seq_before(seq, p->sequence))
  			break;
  	}
  	__skb_queue_before(list, p, skb);
  }
  
  /*
   * Reconstruct a packet from the MP fragment queue.
   * We go through increasing sequence numbers until we find a
   * complete packet, or we get to the sequence number for a fragment
   * which hasn't arrived but might still do so.
   */
  static struct sk_buff *
  ppp_mp_reconstruct(struct ppp *ppp)
  {
  	u32 seq = ppp->nextseq;
  	u32 minseq = ppp->minseq;
  	struct sk_buff_head *list = &ppp->mrq;
  	struct sk_buff *p, *next;
  	struct sk_buff *head, *tail;
  	struct sk_buff *skb = NULL;
  	int lost = 0, len = 0;
  
  	if (ppp->mrru == 0)	/* do nothing until mrru is set */
  		return NULL;
  	head = list->next;
  	tail = NULL;
  	for (p = head; p != (struct sk_buff *) list; p = next) {
  		next = p->next;
  		if (seq_before(p->sequence, seq)) {
  			/* this can't happen, anyway ignore the skb */
  			printk(KERN_ERR "ppp_mp_reconstruct bad seq %u < %u\n",
  			       p->sequence, seq);
  			head = next;
  			continue;
  		}
  		if (p->sequence != seq) {
  			/* Fragment `seq' is missing.  If it is after
  			   minseq, it might arrive later, so stop here. */
  			if (seq_after(seq, minseq))
  				break;
  			/* Fragment `seq' is lost, keep going. */
  			lost = 1;
  			seq = seq_before(minseq, p->sequence)?
  				minseq + 1: p->sequence;
  			next = p;
  			continue;
  		}
  
  		/*
  		 * At this point we know that all the fragments from
  		 * ppp->nextseq to seq are either present or lost.
  		 * Also, there are no complete packets in the queue
  		 * that have no missing fragments and end before this
  		 * fragment.
  		 */
  
  		/* B bit set indicates this fragment starts a packet */
  		if (p->BEbits & B) {
  			head = p;
  			lost = 0;
  			len = 0;
  		}
  
  		len += p->len;
  
  		/* Got a complete packet yet? */
  		if (lost == 0 && (p->BEbits & E) && (head->BEbits & B)) {
  			if (len > ppp->mrru + 2) {
  				++ppp->dev->stats.rx_length_errors;
  				printk(KERN_DEBUG "PPP: reconstructed packet"
  				       " is too long (%d)\n", len);
  			} else if (p == head) {
  				/* fragment is complete packet - reuse skb */
  				tail = p;
  				skb = skb_get(p);
  				break;
  			} else if ((skb = dev_alloc_skb(len)) == NULL) {
  				++ppp->dev->stats.rx_missed_errors;
  				printk(KERN_DEBUG "PPP: no memory for "
  				       "reconstructed packet");
  			} else {
  				tail = p;
  				break;
  			}
  			ppp->nextseq = seq + 1;
  		}
  
  		/*
  		 * If this is the ending fragment of a packet,
  		 * and we haven't found a complete valid packet yet,
  		 * we can discard up to and including this fragment.
  		 */
  		if (p->BEbits & E)
  			head = next;
  
  		++seq;
  	}
  
  	/* If we have a complete packet, copy it all into one skb. */
  	if (tail != NULL) {
  		/* If we have discarded any fragments,
  		   signal a receive error. */
  		if (head->sequence != ppp->nextseq) {
  			if (ppp->debug & 1)
  				printk(KERN_DEBUG "  missed pkts %u..%u\n",
  				       ppp->nextseq, head->sequence-1);
  			++ppp->dev->stats.rx_dropped;
  			ppp_receive_error(ppp);
  		}
  
  		if (head != tail)
  			/* copy to a single skb */
  			for (p = head; p != tail->next; p = p->next)
  				skb_copy_bits(p, 0, skb_put(skb, p->len), p->len);
  		ppp->nextseq = tail->sequence + 1;
  		head = tail->next;
  	}
  
  	/* Discard all the skbuffs that we have copied the data out of
  	   or that we can't use. */
  	while ((p = list->next) != head) {
  		__skb_unlink(p, list);
  		kfree_skb(p);
  	}
  
  	return skb;
  }
  #endif /* CONFIG_PPP_MULTILINK */
  
  /*
   * Channel interface.
   */
  
  /* Create a new, unattached ppp channel. */
  int ppp_register_channel(struct ppp_channel *chan)
  {
  	return ppp_register_net_channel(current->nsproxy->net_ns, chan);
  }
  
  /* Create a new, unattached ppp channel for specified net. */
  int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
  {
  	struct channel *pch;
  	struct ppp_net *pn;
  
  	pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
  	if (!pch)
  		return -ENOMEM;
  
  	pn = ppp_pernet(net);
  
  	pch->ppp = NULL;
  	pch->chan = chan;
  	pch->chan_net = net;
  	chan->ppp = pch;
  	init_ppp_file(&pch->file, CHANNEL);
  	pch->file.hdrlen = chan->hdrlen;
  #ifdef CONFIG_PPP_MULTILINK
  	pch->lastseq = -1;
  #endif /* CONFIG_PPP_MULTILINK */
  	init_rwsem(&pch->chan_sem);
  	spin_lock_init(&pch->downl);
  	rwlock_init(&pch->upl);
  
  	spin_lock_bh(&pn->all_channels_lock);
  	pch->file.index = ++pn->last_channel_index;
  	list_add(&pch->list, &pn->new_channels);
  	atomic_inc(&channel_count);
  	spin_unlock_bh(&pn->all_channels_lock);
  
  	return 0;
  }
  
  /*
   * Return the index of a channel.
   */
  int ppp_channel_index(struct ppp_channel *chan)
  {
  	struct channel *pch = chan->ppp;
  
  	if (pch)
  		return pch->file.index;
  	return -1;
  }
  
  /*
   * Return the PPP unit number to which a channel is connected.
   */
  int ppp_unit_number(struct ppp_channel *chan)
  {
  	struct channel *pch = chan->ppp;
  	int unit = -1;
  
  	if (pch) {
  		read_lock_bh(&pch->upl);
  		if (pch->ppp)
  			unit = pch->ppp->file.index;
  		read_unlock_bh(&pch->upl);
  	}
  	return unit;
  }
  
  /*
   * Return the PPP device interface name of a channel.
   */
  char *ppp_dev_name(struct ppp_channel *chan)
  {
  	struct channel *pch = chan->ppp;
  	char *name = NULL;
  
  	if (pch) {
  		read_lock_bh(&pch->upl);
  		if (pch->ppp && pch->ppp->dev)
  			name = pch->ppp->dev->name;
  		read_unlock_bh(&pch->upl);
  	}
  	return name;
  }
  
  
  /*
   * Disconnect a channel from the generic layer.
   * This must be called in process context.
   */
  void
  ppp_unregister_channel(struct ppp_channel *chan)
  {
  	struct channel *pch = chan->ppp;
  	struct ppp_net *pn;
  
  	if (!pch)
  		return;		/* should never happen */
  
  	chan->ppp = NULL;
  
  	/*
  	 * This ensures that we have returned from any calls into the
  	 * the channel's start_xmit or ioctl routine before we proceed.
  	 */
  	down_write(&pch->chan_sem);
  	spin_lock_bh(&pch->downl);
  	pch->chan = NULL;
  	spin_unlock_bh(&pch->downl);
  	up_write(&pch->chan_sem);
  	ppp_disconnect_channel(pch);
  
  	pn = ppp_pernet(pch->chan_net);
  	spin_lock_bh(&pn->all_channels_lock);
  	list_del(&pch->list);
  	spin_unlock_bh(&pn->all_channels_lock);
  
  	pch->file.dead = 1;
  	wake_up_interruptible(&pch->file.rwait);
  	if (atomic_dec_and_test(&pch->file.refcnt))
  		ppp_destroy_channel(pch);
  }
  
  /*
   * Callback from a channel when it can accept more to transmit.
   * This should be called at BH/softirq level, not interrupt level.
   */
  void
  ppp_output_wakeup(struct ppp_channel *chan)
  {
  	struct channel *pch = chan->ppp;
  
  	if (!pch)
  		return;
  	ppp_channel_push(pch);
  }
  
  /*
   * Compression control.
   */
  
  /* Process the PPPIOCSCOMPRESS ioctl. */
  static int
  ppp_set_compress(struct ppp *ppp, unsigned long arg)
  {
  	int err;
  	struct compressor *cp, *ocomp;
  	struct ppp_option_data data;
  	void *state, *ostate;
  	unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
  
  	err = -EFAULT;
  	if (copy_from_user(&data, (void __user *) arg, sizeof(data)) ||
  	    (data.length <= CCP_MAX_OPTION_LENGTH &&
  	     copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
  		goto out;
  	err = -EINVAL;
  	if (data.length > CCP_MAX_OPTION_LENGTH ||
  	    ccp_option[1] < 2 || ccp_option[1] > data.length)
  		goto out;
  
  	cp = try_then_request_module(
  		find_compressor(ccp_option[0]),
  		"ppp-compress-%d", ccp_option[0]);
  	if (!cp)
  		goto out;
  
  	err = -ENOBUFS;
  	if (data.transmit) {
  		state = cp->comp_alloc(ccp_option, data.length);
  		if (state) {
  			ppp_xmit_lock(ppp);
  			ppp->xstate &= ~SC_COMP_RUN;
  			ocomp = ppp->xcomp;
  			ostate = ppp->xc_state;
  			ppp->xcomp = cp;
  			ppp->xc_state = state;
  			ppp_xmit_unlock(ppp);
  			if (ostate) {
  				ocomp->comp_free(ostate);
  				module_put(ocomp->owner);
  			}
  			err = 0;
  		} else
  			module_put(cp->owner);
  
  	} else {
  		state = cp->decomp_alloc(ccp_option, data.length);
  		if (state) {
  			ppp_recv_lock(ppp);
  			ppp->rstate &= ~SC_DECOMP_RUN;
  			ocomp = ppp->rcomp;
  			ostate = ppp->rc_state;
  			ppp->rcomp = cp;
  			ppp->rc_state = state;
  			ppp_recv_unlock(ppp);
  			if (ostate) {
  				ocomp->decomp_free(ostate);
  				module_put(ocomp->owner);
  			}
  			err = 0;
  		} else
  			module_put(cp->owner);
  	}
  
   out:
  	return err;
  }
  
  /*
   * Look at a CCP packet and update our state accordingly.
   * We assume the caller has the xmit or recv path locked.
   */
  static void
  ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
  {
  	unsigned char *dp;
  	int len;
  
  	if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
  		return;	/* no header */
  	dp = skb->data + 2;
  
  	switch (CCP_CODE(dp)) {
  	case CCP_CONFREQ:
  
  		/* A ConfReq starts negotiation of compression
  		 * in one direction of transmission,
  		 * and hence brings it down...but which way?
  		 *
  		 * Remember:
  		 * A ConfReq indicates what the sender would like to receive
  		 */
  		if(inbound)
  			/* He is proposing what I should send */
  			ppp->xstate &= ~SC_COMP_RUN;
  		else
  			/* I am proposing to what he should send */
  			ppp->rstate &= ~SC_DECOMP_RUN;
  
  		break;
  
  	case CCP_TERMREQ:
  	case CCP_TERMACK:
  		/*
  		 * CCP is going down, both directions of transmission
  		 */
  		ppp->rstate &= ~SC_DECOMP_RUN;
  		ppp->xstate &= ~SC_COMP_RUN;
  		break;
  
  	case CCP_CONFACK:
  		if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
  			break;
  		len = CCP_LENGTH(dp);
  		if (!pskb_may_pull(skb, len + 2))
  			return;		/* too short */
  		dp += CCP_HDRLEN;
  		len -= CCP_HDRLEN;
  		if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
  			break;
  		if (inbound) {
  			/* we will start receiving compressed packets */
  			if (!ppp->rc_state)
  				break;
  			if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
  					ppp->file.index, 0, ppp->mru, ppp->debug)) {
  				ppp->rstate |= SC_DECOMP_RUN;
  				ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
  			}
  		} else {
  			/* we will soon start sending compressed packets */
  			if (!ppp->xc_state)
  				break;
  			if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
  					ppp->file.index, 0, ppp->debug))
  				ppp->xstate |= SC_COMP_RUN;
  		}
  		break;
  
  	case CCP_RESETACK:
  		/* reset the [de]compressor */
  		if ((ppp->flags & SC_CCP_UP) == 0)
  			break;
  		if (inbound) {
  			if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
  				ppp->rcomp->decomp_reset(ppp->rc_state);
  				ppp->rstate &= ~SC_DC_ERROR;
  			}
  		} else {
  			if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
  				ppp->xcomp->comp_reset(ppp->xc_state);
  		}
  		break;
  	}
  }
  
  /* Free up compression resources. */
  static void
  ppp_ccp_closed(struct ppp *ppp)
  {
  	void *xstate, *rstate;
  	struct compressor *xcomp, *rcomp;
  
  	ppp_lock(ppp);
  	ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
  	ppp->xstate = 0;
  	xcomp = ppp->xcomp;
  	xstate = ppp->xc_state;
  	ppp->xc_state = NULL;
  	ppp->rstate = 0;
  	rcomp = ppp->rcomp;
  	rstate = ppp->rc_state;
  	ppp->rc_state = NULL;
  	ppp_unlock(ppp);
  
  	if (xstate) {
  		xcomp->comp_free(xstate);
  		module_put(xcomp->owner);
  	}
  	if (rstate) {
  		rcomp->decomp_free(rstate);
  		module_put(rcomp->owner);
  	}
  }
  
  /* List of compressors. */
  static LIST_HEAD(compressor_list);
  static DEFINE_SPINLOCK(compressor_list_lock);
  
  struct compressor_entry {
  	struct list_head list;
  	struct compressor *comp;
  };
  
  static struct compressor_entry *
  find_comp_entry(int proto)
  {
  	struct compressor_entry *ce;
  
  	list_for_each_entry(ce, &compressor_list, list) {
  		if (ce->comp->compress_proto == proto)
  			return ce;
  	}
  	return NULL;
  }
  
  /* Register a compressor */
  int
  ppp_register_compressor(struct compressor *cp)
  {
  	struct compressor_entry *ce;
  	int ret;
  	spin_lock(&compressor_list_lock);
  	ret = -EEXIST;
  	if (find_comp_entry(cp->compress_proto))
  		goto out;
  	ret = -ENOMEM;
  	ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
  	if (!ce)
  		goto out;
  	ret = 0;
  	ce->comp = cp;
  	list_add(&ce->list, &compressor_list);
   out:
  	spin_unlock(&compressor_list_lock);
  	return ret;
  }
  
  /* Unregister a compressor */
  void
  ppp_unregister_compressor(struct compressor *cp)
  {
  	struct compressor_entry *ce;
  
  	spin_lock(&compressor_list_lock);
  	ce = find_comp_entry(cp->compress_proto);
  	if (ce && ce->comp == cp) {
  		list_del(&ce->list);
  		kfree(ce);
  	}
  	spin_unlock(&compressor_list_lock);
  }
  
  /* Find a compressor. */
  static struct compressor *
  find_compressor(int type)
  {
  	struct compressor_entry *ce;
  	struct compressor *cp = NULL;
  
  	spin_lock(&compressor_list_lock);
  	ce = find_comp_entry(type);
  	if (ce) {
  		cp = ce->comp;
  		if (!try_module_get(cp->owner))
  			cp = NULL;
  	}
  	spin_unlock(&compressor_list_lock);
  	return cp;
  }
  
  /*
   * Miscelleneous stuff.
   */
  
  static void
  ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
  {
  	struct slcompress *vj = ppp->vj;
  
  	memset(st, 0, sizeof(*st));
  	st->p.ppp_ipackets = ppp->dev->stats.rx_packets;
  	st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
  	st->p.ppp_ibytes = ppp->dev->stats.rx_bytes;
  	st->p.ppp_opackets = ppp->dev->stats.tx_packets;
  	st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
  	st->p.ppp_obytes = ppp->dev->stats.tx_bytes;
  	if (!vj)
  		return;
  	st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
  	st->vj.vjs_compressed = vj->sls_o_compressed;
  	st->vj.vjs_searches = vj->sls_o_searches;
  	st->vj.vjs_misses = vj->sls_o_misses;
  	st->vj.vjs_errorin = vj->sls_i_error;
  	st->vj.vjs_tossed = vj->sls_i_tossed;
  	st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
  	st->vj.vjs_compressedin = vj->sls_i_compressed;
  }
  
  /*
   * Stuff for handling the lists of ppp units and channels
   * and for initialization.
   */
  
  /*
   * Create a new ppp interface unit.  Fails if it can't allocate memory
   * or if there is already a unit with the requested number.
   * unit == -1 means allocate a new number.
   */
  static struct ppp *
  ppp_create_interface(struct net *net, int unit, int *retp)
  {
  	struct ppp *ppp;
  	struct ppp_net *pn;
  	struct net_device *dev = NULL;
  	int ret = -ENOMEM;
  	int i;
  
  	dev = alloc_netdev(sizeof(struct ppp), "", ppp_setup);
  	if (!dev)
  		goto out1;
  
  	pn = ppp_pernet(net);
  
  	ppp = netdev_priv(dev);
  	ppp->dev = dev;
  	ppp->mru = PPP_MRU;
  	init_ppp_file(&ppp->file, INTERFACE);
  	ppp->file.hdrlen = PPP_HDRLEN - 2;	/* don't count proto bytes */
  	for (i = 0; i < NUM_NP; ++i)
  		ppp->npmode[i] = NPMODE_PASS;
  	INIT_LIST_HEAD(&ppp->channels);
  	spin_lock_init(&ppp->rlock);
  	spin_lock_init(&ppp->wlock);
  #ifdef CONFIG_PPP_MULTILINK
  	ppp->minseq = -1;
  	skb_queue_head_init(&ppp->mrq);
  #endif /* CONFIG_PPP_MULTILINK */
  
  	/*
  	 * drum roll: don't forget to set
  	 * the net device is belong to
  	 */
  	dev_net_set(dev, net);
  
  	ret = -EEXIST;
  	mutex_lock(&pn->all_ppp_mutex);
  
  	if (unit < 0) {
  		unit = unit_get(&pn->units_idr, ppp);
  		if (unit < 0) {
  			*retp = unit;
  			goto out2;
  		}
  	} else {
  		if (unit_find(&pn->units_idr, unit))
  			goto out2; /* unit already exists */
  		/*
  		 * if caller need a specified unit number
  		 * lets try to satisfy him, otherwise --
  		 * he should better ask us for new unit number
  		 *
  		 * NOTE: yes I know that returning EEXIST it's not
  		 * fair but at least pppd will ask us to allocate
  		 * new unit in this case so user is happy :)
  		 */
  		unit = unit_set(&pn->units_idr, ppp, unit);
  		if (unit < 0)
  			goto out2;
  	}
  
  	/* Initialize the new ppp unit */
  	ppp->file.index = unit;
  	sprintf(dev->name, "ppp%d", unit);
  
  	ret = register_netdev(dev);
  	if (ret != 0) {
  		unit_put(&pn->units_idr, unit);
  		printk(KERN_ERR "PPP: couldn't register device %s (%d)\n",
  		       dev->name, ret);
  		goto out2;
  	}
  
  	ppp->ppp_net = net;
  
  #ifdef HNDCTF
  	if ((ctf_dev_register(kcih, dev, FALSE) != BCME_OK) ||
  	    (ctf_enable(kcih, dev, TRUE, NULL) != BCME_OK))
  		ctf_dev_unregister(kcih, dev);
  #endif
  
  	atomic_inc(&ppp_unit_count);
  	mutex_unlock(&pn->all_ppp_mutex);
  
  	*retp = 0;
  	return ppp;
  
  out2:
  	mutex_unlock(&pn->all_ppp_mutex);
  	free_netdev(dev);
  out1:
  	*retp = ret;
  	return NULL;
  }
  
  /*
   * Initialize a ppp_file structure.
   */
  static void
  init_ppp_file(struct ppp_file *pf, int kind)
  {
  	pf->kind = kind;
  	skb_queue_head_init(&pf->xq);
  	skb_queue_head_init(&pf->rq);
  	atomic_set(&pf->refcnt, 1);
  	init_waitqueue_head(&pf->rwait);
  }
  
  /*
   * Take down a ppp interface unit - called when the owning file
   * (the one that created the unit) is closed or detached.
   */
  static void ppp_shutdown_interface(struct ppp *ppp)
  {
  	struct ppp_net *pn;
  
  	pn = ppp_pernet(ppp->ppp_net);
  	mutex_lock(&pn->all_ppp_mutex);
  
  	/* This will call dev_close() for us. */
  	ppp_lock(ppp);
  	if (!ppp->closing) {
  		ppp->closing = 1;
  		ppp_unlock(ppp);
  #ifdef HNDCTF
  		ctf_dev_unregister(kcih, ppp->dev);
  #endif
  		unregister_netdev(ppp->dev);
  	} else
  		ppp_unlock(ppp);
  
  	unit_put(&pn->units_idr, ppp->file.index);
  	ppp->file.dead = 1;
  	ppp->owner = NULL;
  	wake_up_interruptible(&ppp->file.rwait);
  
  	mutex_unlock(&pn->all_ppp_mutex);
  }
  
  /*
   * Free the memory used by a ppp unit.  This is only called once
   * there are no channels connected to the unit and no file structs
   * that reference the unit.
   */
  static void ppp_destroy_interface(struct ppp *ppp)
  {
  	atomic_dec(&ppp_unit_count);
  
  	if (!ppp->file.dead || ppp->n_channels) {
  		/* "can't happen" */
  		printk(KERN_ERR "ppp: destroying ppp struct %p but dead=%d "
  		       "n_channels=%d !\n", ppp, ppp->file.dead,
  		       ppp->n_channels);
  		return;
  	}
  
  	ppp_ccp_closed(ppp);
  	if (ppp->vj) {
  		slhc_free(ppp->vj);
  		ppp->vj = NULL;
  	}
  	skb_queue_purge(&ppp->file.xq);
  	skb_queue_purge(&ppp->file.rq);
  #ifdef CONFIG_PPP_MULTILINK
  	skb_queue_purge(&ppp->mrq);
  #endif /* CONFIG_PPP_MULTILINK */
  #ifdef CONFIG_PPP_FILTER
  	kfree(ppp->pass_filter);
  	ppp->pass_filter = NULL;
  	kfree(ppp->active_filter);
  	ppp->active_filter = NULL;
  #endif /* CONFIG_PPP_FILTER */
  
  	kfree_skb(ppp->xmit_pending);
  
  	free_netdev(ppp->dev);
  }
  
  /*
   * Locate an existing ppp unit.
   * The caller should have locked the all_ppp_mutex.
   */
  static struct ppp *
  ppp_find_unit(struct ppp_net *pn, int unit)
  {
  	return unit_find(&pn->units_idr, unit);
  }
  
  /*
   * Locate an existing ppp channel.
   * The caller should have locked the all_channels_lock.
   * First we look in the new_channels list, then in the
   * all_channels list.  If found in the new_channels list,
   * we move it to the all_channels list.  This is for speed
   * when we have a lot of channels in use.
   */
  static struct channel *
  ppp_find_channel(struct ppp_net *pn, int unit)
  {
  	struct channel *pch;
  
  	list_for_each_entry(pch, &pn->new_channels, list) {
  		if (pch->file.index == unit) {
  			list_move(&pch->list, &pn->all_channels);
  			return pch;
  		}
  	}
  
  	list_for_each_entry(pch, &pn->all_channels, list) {
  		if (pch->file.index == unit)
  			return pch;
  	}
  
  	return NULL;
  }
  
  /*
   * Connect a PPP channel to a PPP interface unit.
   */
  static int
  ppp_connect_channel(struct channel *pch, int unit)
  {
  	struct ppp *ppp;
  	struct ppp_net *pn;
  	int ret = -ENXIO;
  	int hdrlen;
  
  	pn = ppp_pernet(pch->chan_net);
  
  	mutex_lock(&pn->all_ppp_mutex);
  	ppp = ppp_find_unit(pn, unit);
  	if (!ppp)
  		goto out;
  	write_lock_bh(&pch->upl);
  	ret = -EINVAL;
  	if (pch->ppp)
  		goto outl;
  
  	ppp_lock(ppp);
  	if (pch->file.hdrlen > ppp->file.hdrlen)
  		ppp->file.hdrlen = pch->file.hdrlen;
  	hdrlen = pch->file.hdrlen + 2;	/* for protocol bytes */
  	if (hdrlen > ppp->dev->hard_header_len)
  		ppp->dev->hard_header_len = hdrlen;
  	list_add_tail(&pch->clist, &ppp->channels);
  	++ppp->n_channels;
  	pch->ppp = ppp;
  #ifdef HNDCTF
          ppp->ctfpch = pch;
  #endif         
  	atomic_inc(&ppp->file.refcnt);
  	ppp_unlock(ppp);
  	ret = 0;
  
   outl:
  	write_unlock_bh(&pch->upl);
   out:
  	mutex_unlock(&pn->all_ppp_mutex);
  	return ret;
  }
  
  /*
   * Disconnect a channel from its ppp unit.
   */
  static int
  ppp_disconnect_channel(struct channel *pch)
  {
  	struct ppp *ppp;
  	int err = -EINVAL;
  
  	write_lock_bh(&pch->upl);
  	ppp = pch->ppp;
  	pch->ppp = NULL;
  	write_unlock_bh(&pch->upl);
  	if (ppp) {
  		/* remove it from the ppp unit's list */
  		ppp_lock(ppp);
  		list_del(&pch->clist);
  		if (--ppp->n_channels == 0)
  			wake_up_interruptible(&ppp->file.rwait);
  		ppp_unlock(ppp);
  #ifdef HNDCTF
  		ppp->ctfpch = NULL;
  #endif
  		if (atomic_dec_and_test(&ppp->file.refcnt))
  			ppp_destroy_interface(ppp);
  		err = 0;
  	}
  	return err;
  }
  
  /*
   * Free up the resources used by a ppp channel.
   */
  static void ppp_destroy_channel(struct channel *pch)
  {
  	atomic_dec(&channel_count);
  
  	if (!pch->file.dead) {
  		/* "can't happen" */
  		printk(KERN_ERR "ppp: destroying undead channel %p !\n",
  		       pch);
  		return;
  	}
  	skb_queue_purge(&pch->file.xq);
  	skb_queue_purge(&pch->file.rq);
  	kfree(pch);
  }
  
  static void __exit ppp_cleanup(void)
  {
  	/* should never happen */
  	if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
  		printk(KERN_ERR "PPP: removing module but units remain!\n");
  	unregister_chrdev(PPP_MAJOR, "ppp");
  	device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
  	class_destroy(ppp_class);
  	unregister_pernet_device(&ppp_net_ops);
  }
  
  /*
   * Units handling. Caller must protect concurrent access
   * by holding all_ppp_mutex
   */
  
  /* associate pointer with specified number */
  static int unit_set(struct idr *p, void *ptr, int n)
  {
  	int unit, err;
  
  again:
  	if (!idr_pre_get(p, GFP_KERNEL)) {
  		printk(KERN_ERR "PPP: No free memory for idr\n");
  		return -ENOMEM;
  	}
  
  	err = idr_get_new_above(p, ptr, n, &unit);
  	if (err == -EAGAIN)
  		goto again;
  
  	if (unit != n) {
  		idr_remove(p, unit);
  		return -EINVAL;
  	}
  
  	return unit;
  }
  
  /* get new free unit number and associate pointer with it */
  static int unit_get(struct idr *p, void *ptr)
  {
  	int unit, err;
  
  again:
  	if (!idr_pre_get(p, GFP_KERNEL)) {
  		printk(KERN_ERR "PPP: No free memory for idr\n");
  		return -ENOMEM;
  	}
  
  	err = idr_get_new_above(p, ptr, 0, &unit);
  	if (err == -EAGAIN)
  		goto again;
  
  	return unit;
  }
  
  /* put unit number back to a pool */
  static void unit_put(struct idr *p, int n)
  {
  	idr_remove(p, n);
  }
  
  /* get pointer associated with the number */
  static void *unit_find(struct idr *p, int n)
  {
  	return idr_find(p, n);
  }
  
  #if defined(CTF_PPPOE) || defined(CTF_PPTP) || defined(CTF_L2TP)
  void
  ppp_rxstats_upd(void *pppif, struct sk_buff *skb)
  {
  	if (pppif == NULL || skb == NULL) return;
  	struct ppp *ppp = netdev_priv((const struct net_device *)pppif);
  	if (ppp == NULL || ppp->dev == NULL) return;
  	++ppp->dev->stats.rx_packets;
  	ppp->dev->stats.rx_bytes += skb->len;
  	ppp->last_recv = jiffies;
  }
  
  void
  ppp_txstats_upd(void *pppif, struct sk_buff *skb)
  {
  	if (pppif == NULL || skb == NULL) return;
  	struct ppp *ppp = netdev_priv((const struct net_device *)pppif);
  	if (ppp == NULL || ppp->dev == NULL) return;
  	++ppp->dev->stats.tx_packets;
  	ppp->dev->stats.tx_bytes += skb->len;
  	ppp->last_xmit = jiffies;
  }
  
  #if defined(CTF_PPTP) || defined(CTF_L2TP)
  int
  ppp_get_conn_pkt_info(void *pppif, struct ctf_ppp *ctfppp)
  {
          struct pppox_sock *po = NULL;
          struct sock *sk = NULL;
          struct ppp *ppp = NULL;
          struct channel *pch = NULL;
          struct ppp_net *pn;
          const char *vars;
  
  
          ppp = (struct ppp *)netdev_priv((const struct net_device *)pppif);
          if(ppp) pch = ppp->ctfpch;
  
          if (pch == NULL){
                  return (BCME_ERROR);
          }
  
  
          po = pppox_sk((struct sock *)pch->chan->private);
  
          if (po == NULL){
                  return (BCME_ERROR);
          }
          ctfppp->psk.po = po;
  
  
          sk = po->chan.private;
  	if (sk && sk == &po->sk){
                  ctfppp->psk.pppox_protocol = sk->sk_protocol;
                  switch (sk->sk_protocol){
                  case PX_PROTO_OE:
                          ctfppp->pppox_id = po->pppoe_pa.sid;
                          memcpy(ctfppp->psk.dhost.octet , po->pppoe_pa.remote, ETH_ALEN);
  
  #ifdef DEBUG
                  printk("%s: Adding pppoe connection:  session ID =%04x, Address=%02x:%02x:%02x:%02x:%02x:%02x\n",
                          __FUNCTION__,ntohs(ctfppp->pppox_id),
                                  ctfppp->psk.dhost.octet[0], ctfppp->psk.dhost.octet[1],
                                  ctfppp->psk.dhost.octet[2], ctfppp->psk.dhost.octet[3],
                                  ctfppp->psk.dhost.octet[4], ctfppp->psk.dhost.octet[5]);
  #endif /*DEBUG*/
                          break;
  #ifdef CTF_PPTP                 
                  case PX_PROTO_PPTP:
                          ctfppp->pppox_id = 0xffff;
  #ifdef DEBUG
  
                  printk("%s: Adding pptp entry:  src call ID =%04x, src ip=%u.%u.%u.%u, dst call ID=%4x, dst ip=%u.%u.%u.%u\n ",
                          __FUNCTION__,po->proto.pptp.dst_addr.call_id,   NIPQUAD(po->proto.pptp.src_addr.sin_addr.s_addr),
                          po->proto.pptp.dst_addr.call_id,NIPQUAD(po->proto.pptp.dst_addr.sin_addr.s_addr));
  
  #endif
                          break;
  #endif /*CTF_PPTP*/
  #ifdef CTF_L2TP                 
                  case PX_PROTO_OL2TP:
                          ctfppp->pppox_id = 0xffff;
  #ifdef DEBUG
                  printk("%s: Adding l2tp entry:\n", __FUNCTION__);
                  printk("local tunnel ID =0x%04x,session ID =0x%04x, src ip=%u.%u.%u.%u\n",
                          po->proto.l2tp.ts.tunnel_id, po->proto.l2tp.ts.session_id,NIPQUAD(po->proto.l2tp.inet.saddr));
                  printk("peer  tunnel ID=0x%4x, session ID = 0x%04x, dst ip=%u.%u.%u.%u\n ",
                          po->proto.l2tp.ts.peer_tunnel_id, po->proto.l2tp.ts.peer_session_id,NIPQUAD(po->proto.l2tp.inet.daddr));
                  printk("header len =%d\n", po->proto.l2tp.ts.l2tph_len);
  
  #endif
                          break;
  #endif /* CTF_L2TP*/
  
                  default:
                          return (BCME_ERROR);
                  }
          }
          else{
                  return (BCME_ERROR);
          }
          return (BCME_OK);
  
  }
  EXPORT_SYMBOL(ppp_get_conn_pkt_info);
  #endif /** defined(CTF_PPTP) || defined(CTF_L2TP) **/
  
  EXPORT_SYMBOL(ppp_rxstats_upd);
  EXPORT_SYMBOL(ppp_txstats_upd);
  #endif /** defined(CTF_PPPOE) || defined(CTF_PPTP) || defined(CTF_L2TP) **/
  
  /* Module/initialization stuff */
  
  module_init(ppp_init);
  module_exit(ppp_cleanup);
  
  EXPORT_SYMBOL(ppp_register_net_channel);
  EXPORT_SYMBOL(ppp_register_channel);
  EXPORT_SYMBOL(ppp_unregister_channel);
  EXPORT_SYMBOL(ppp_channel_index);
  EXPORT_SYMBOL(ppp_unit_number);
  EXPORT_SYMBOL(ppp_dev_name);
  EXPORT_SYMBOL(ppp_input);
  EXPORT_SYMBOL(ppp_input_error);
  EXPORT_SYMBOL(ppp_output_wakeup);
  EXPORT_SYMBOL(ppp_register_compressor);
  EXPORT_SYMBOL(ppp_unregister_compressor);
  MODULE_LICENSE("GPL");
  MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
  MODULE_ALIAS("devname:ppp");
  