ppp: Move the PPP drivers

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

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

1 files changed, 0 insertions, 2954 deletions

diff --git a/drivers/net/ppp_generic.c b/drivers/net/ppp_generic.c
deleted file mode 100644
index 10e5d985afa3..000000000000
--- a/drivers/net/ppp_generic.c
+++ /dev/null
@@ -1,2954 +0,0 @@
-/*
- * 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 <asm/unaligned.h>
-#include <net/slhc_vj.h>
-#include <linux/atomic.h>
-
-#include <linux/nsproxy.h>
-#include <net/net_namespace.h>
-#include <net/netns/generic.h>
-
-#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)
-
-/*
- * 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 */
-};
-
-/*
- * 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)	get_unaligned_be16((skb)->data)
-
-/* 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
-			pr_warn("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 */
-		pr_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) {
-			netdev_err(ppp->dev,
-				   "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,
-	.llseek		= noop_llseek,
-};
-
-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;
-
-	pr_info("PPP generic driver version " PPP_VERSION "\n");
-
-	err = register_pernet_device(&ppp_net_ops);
-	if (err) {
-		pr_err("failed to register PPP pernet device (%d)\n", err);
-		goto out;
-	}
-
-	err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
-	if (err) {
-		pr_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];
-	put_unaligned_be16(proto, pp);
-
-	netif_stop_queue(dev);
-	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);
-	}
-	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())
-			netdev_err(ppp->dev, "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())
-			netdev_err(ppp->dev, "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) == 0) {
-			if (ppp->debug & 1)
-				netdev_printk(KERN_DEBUG, ppp->dev,
-					      "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) == 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) {
-			netdev_err(ppp->dev, "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())
-				netdev_err(ppp->dev,
-					   "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
-static bool mp_protocol_compress __read_mostly = true;
-module_param(mp_protocol_compress, bool, S_IRUGO | S_IWUSR);
-MODULE_PARM_DESC(mp_protocol_compress,
-		 "compress protocol id in multilink fragments");
-
-/*
- * 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 */
-
-	/* Do protocol field compression */
-	p = skb->data;
-	len = skb->len;
-	if (*p == 0 && mp_protocol_compress) {
-		++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 length 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 */
-		put_unaligned_be16(PPP_MP, q);
-		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)
-		netdev_err(ppp->dev, "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.
- */
-
-struct ppp_mp_skb_parm {
-	u32		sequence;
-	u8		BEbits;
-};
-#define PPP_MP_CB(skb)	((struct ppp_mp_skb_parm *)((skb)->cb))
-
-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
-		/* XXX do channel-level decompression here */
-		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) {
-				netdev_err(ppp->dev, "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) {
-			netdev_printk(KERN_DEBUG, ppp->dev,
-				      "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) {
-			netdev_err(ppp->dev, "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) == 0) {
-				if (ppp->debug & 1)
-					netdev_printk(KERN_DEBUG, ppp->dev,
-						      "PPP: inbound frame "
-						      "not passed\n");
-				kfree_skb(skb);
-				return;
-			}
-			if (!(ppp->active_filter &&
-			      sk_run_filter(skb, ppp->active_filter) == 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) {
-			netdev_err(ppp->dev, "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;
-	}
-	PPP_MP_CB(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 ((PPP_MP_CB(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 */
-	PPP_MP_CB(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, PPP_MP_CB(mskb)->sequence))
-			ppp->minseq = PPP_MP_CB(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 = PPP_MP_CB(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, PPP_MP_CB(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, *tmp;
-	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;
-	skb_queue_walk_safe(list, p, tmp) {
-	again:
-		if (seq_before(PPP_MP_CB(p)->sequence, seq)) {
-			/* this can't happen, anyway ignore the skb */
-			netdev_err(ppp->dev, "ppp_mp_reconstruct bad "
-				   "seq %u < %u\n",
-				   PPP_MP_CB(p)->sequence, seq);
-			__skb_unlink(p, list);
-			kfree_skb(p);
-			continue;
-		}
-		if (PPP_MP_CB(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, PPP_MP_CB(p)->sequence)?
-				minseq + 1: PPP_MP_CB(p)->sequence;
-			goto again;
-		}
-
-		/*
-		 * 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 (PPP_MP_CB(p)->BEbits & B) {
-			head = p;
-			lost = 0;
-			len = 0;
-		}
-
-		len += p->len;
-
-		/* Got a complete packet yet? */
-		if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) &&
-		    (PPP_MP_CB(head)->BEbits & B)) {
-			if (len > ppp->mrru + 2) {
-				++ppp->dev->stats.rx_length_errors;
-				netdev_printk(KERN_DEBUG, ppp->dev,
-					      "PPP: reconstructed packet"
-					      " is too long (%d)\n", len);
-			} 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 (PPP_MP_CB(p)->BEbits & E) {
-			struct sk_buff *tmp2;
-
-			skb_queue_reverse_walk_from_safe(list, p, tmp2) {
-				__skb_unlink(p, list);
-				kfree_skb(p);
-			}
-			head = skb_peek(list);
-			if (!head)
-				break;
-		}
-		++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 (PPP_MP_CB(head)->sequence != ppp->nextseq) {
-			if (ppp->debug & 1)
-				netdev_printk(KERN_DEBUG, ppp->dev,
-					      "  missed pkts %u..%u\n",
-					      ppp->nextseq,
-					      PPP_MP_CB(head)->sequence-1);
-			++ppp->dev->stats.rx_dropped;
-			ppp_receive_error(ppp);
-		}
-
-		skb = head;
-		if (head != tail) {
-			struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list;
-			p = skb_queue_next(list, head);
-			__skb_unlink(skb, list);
-			skb_queue_walk_from_safe(list, p, tmp) {
-				__skb_unlink(p, list);
-				*fragpp = p;
-				p->next = NULL;
-				fragpp = &p->next;
-
-				skb->len += p->len;
-				skb->data_len += p->len;
-				skb->truesize += p->len;
-
-				if (p == tail)
-					break;
-			}
-		} else {
-			__skb_unlink(skb, list);
-		}
-
-		ppp->nextseq = PPP_MP_CB(tail)->sequence + 1;
-	}
-
-	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);
-
-	mutex_lock(&pn->all_ppp_mutex);
-
-	if (unit < 0) {
-		unit = unit_get(&pn->units_idr, ppp);
-		if (unit < 0) {
-			ret = unit;
-			goto out2;
-		}
-	} else {
-		ret = -EEXIST;
-		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);
-		netdev_err(ppp->dev, "PPP: couldn't register device %s (%d)\n",
-			   dev->name, ret);
-		goto out2;
-	}
-
-	ppp->ppp_net = net;
-
-	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);
-		unregister_netdev(ppp->dev);
-		unit_put(&pn->units_idr, ppp->file.index);
-	} else
-		ppp_unlock(ppp);
-
-	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" */
-		netdev_err(ppp->dev, "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;
-	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);
-		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" */
-		pr_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))
-		pr_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
- */
-
-static int __unit_alloc(struct idr *p, void *ptr, int n)
-{
-	int unit, err;
-
-again:
-	if (!idr_pre_get(p, GFP_KERNEL)) {
-		pr_err("PPP: No free memory for idr\n");
-		return -ENOMEM;
-	}
-
-	err = idr_get_new_above(p, ptr, n, &unit);
-	if (err < 0) {
-		if (err == -EAGAIN)
-			goto again;
-		return err;
-	}
-
-	return unit;
-}
-
-/* associate pointer with specified number */
-static int unit_set(struct idr *p, void *ptr, int n)
-{
-	int unit;
-
-	unit = __unit_alloc(p, ptr, n);
-	if (unit < 0)
-		return unit;
-	else 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)
-{
-	return __unit_alloc(p, ptr, 0);
-}
-
-/* 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);
-}
-
-/* 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");