ppp_generic.c 68.5 KB
Newer Older
L
Linus Torvalds 已提交
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
/*
 * 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>
30
#include <linux/idr.h>
L
Linus Torvalds 已提交
31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46
#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>
47
#include <linux/mutex.h>
48
#include <linux/slab.h>
L
Linus Torvalds 已提交
49 50 51
#include <net/slhc_vj.h>
#include <asm/atomic.h>

52 53 54 55
#include <linux/nsproxy.h>
#include <net/net_namespace.h>
#include <net/netns/generic.h>

L
Linus Torvalds 已提交
56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89
#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 */
};

90
#define PF_TO_X(pf, X)		container_of(pf, X, file)
L
Linus Torvalds 已提交
91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122

#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 */
123
	int		closing;	/* is device closing down? a8 */
L
Linus Torvalds 已提交
124 125 126 127 128 129 130 131 132 133 134 135 136
#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 */
137
	struct net	*ppp_net;	/* the net we belong to */
L
Linus Torvalds 已提交
138 139 140 141
};

/*
 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
142 143
 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
 * SC_MUST_COMP
L
Linus Torvalds 已提交
144 145 146 147 148
 * 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 \
149
			 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
L
Linus Torvalds 已提交
150 151 152 153 154 155 156 157 158 159 160 161

/*
 * 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 */
162
	struct net	*chan_net;	/* the net channel belongs to */
L
Linus Torvalds 已提交
163 164 165 166 167 168
	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 */
169
	int		speed;		/* speed of the corresponding ppp channel*/
L
Linus Torvalds 已提交
170 171 172 173 174 175 176 177 178 179 180 181
#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.
 */

182
static DEFINE_MUTEX(ppp_mutex);
L
Linus Torvalds 已提交
183 184 185
static atomic_t ppp_unit_count = ATOMIC_INIT(0);
static atomic_t channel_count = ATOMIC_INIT(0);

186
/* per-net private data for this module */
187
static int ppp_net_id __read_mostly;
188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211
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;
};

L
Linus Torvalds 已提交
212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234
/* 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. */
235 236
static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
			struct file *file, unsigned int cmd, unsigned long arg);
L
Linus Torvalds 已提交
237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258
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);
259
static struct ppp *ppp_create_interface(struct net *net, int unit, int *retp);
L
Linus Torvalds 已提交
260 261 262
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);
263 264
static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit);
static struct channel *ppp_find_channel(struct ppp_net *pn, int unit);
L
Linus Torvalds 已提交
265 266 267
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);
268
static int unit_get(struct idr *p, void *ptr);
269
static int unit_set(struct idr *p, void *ptr, int n);
270 271
static void unit_put(struct idr *p, int n);
static void *unit_find(struct idr *p, int n);
L
Linus Torvalds 已提交
272

273
static struct class *ppp_class;
L
Linus Torvalds 已提交
274

275 276 277 278 279 280 281 282
/* per net-namespace data */
static inline struct ppp_net *ppp_pernet(struct net *net)
{
	BUG_ON(!net);

	return net_generic(net, ppp_net_id);
}

L
Linus Torvalds 已提交
283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311
/* 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,
};
312

L
Linus Torvalds 已提交
313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372
/* 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;
}

A
Alan Cox 已提交
373
static int ppp_release(struct inode *unused, struct file *file)
L
Linus Torvalds 已提交
374 375 376 377
{
	struct ppp_file *pf = file->private_data;
	struct ppp *ppp;

J
Joe Perches 已提交
378
	if (pf) {
L
Linus Torvalds 已提交
379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405
		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;
406
	struct iovec iov;
L
Linus Torvalds 已提交
407 408 409

	ret = count;

J
Joe Perches 已提交
410
	if (!pf)
L
Linus Torvalds 已提交
411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427
		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);
428 429
			if (ppp->n_channels == 0 &&
			    (ppp->flags & SC_LOOP_TRAFFIC) == 0)
L
Linus Torvalds 已提交
430 431 432 433 434 435 436 437 438 439 440 441 442
				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);

J
Joe Perches 已提交
443
	if (!skb)
L
Linus Torvalds 已提交
444 445 446 447 448 449
		goto out;

	ret = -EOVERFLOW;
	if (skb->len > count)
		goto outf;
	ret = -EFAULT;
450 451 452
	iov.iov_base = buf;
	iov.iov_len = count;
	if (skb_copy_datagram_iovec(skb, 0, &iov, skb->len))
L
Linus Torvalds 已提交
453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468
		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;

J
Joe Perches 已提交
469
	if (!pf)
L
Linus Torvalds 已提交
470 471 472
		return -ENXIO;
	ret = -ENOMEM;
	skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
J
Joe Perches 已提交
473
	if (!skb)
L
Linus Torvalds 已提交
474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504
		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;

J
Joe Perches 已提交
505
	if (!pf)
L
Linus Torvalds 已提交
506 507 508
		return 0;
	poll_wait(file, &pf->rwait, wait);
	mask = POLLOUT | POLLWRNORM;
J
Joe Perches 已提交
509
	if (skb_peek(&pf->rq))
L
Linus Torvalds 已提交
510 511 512 513 514 515
		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);
516 517
		if (ppp->n_channels == 0 &&
		    (ppp->flags & SC_LOOP_TRAFFIC) == 0)
L
Linus Torvalds 已提交
518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539
			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);
J
Julia Lawall 已提交
540 541 542
	code = memdup_user(uprog.filter, len);
	if (IS_ERR(code))
		return PTR_ERR(code);
L
Linus Torvalds 已提交
543 544 545 546 547 548 549 550 551 552 553 554

	err = sk_chk_filter(code, uprog.len);
	if (err) {
		kfree(code);
		return err;
	}

	*p = code;
	return uprog.len;
}
#endif /* CONFIG_PPP_FILTER */

A
Alan Cox 已提交
555
static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
L
Linus Torvalds 已提交
556 557 558 559 560 561 562 563 564 565 566
{
	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;

J
Joe Perches 已提交
567
	if (!pf)
568 569
		return ppp_unattached_ioctl(current->nsproxy->net_ns,
					pf, file, cmd, arg);
L
Linus Torvalds 已提交
570 571 572 573 574 575 576 577 578 579 580 581 582 583

	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;
584
		mutex_lock(&ppp_mutex);
L
Linus Torvalds 已提交
585 586 587 588 589
		if (pf->kind == INTERFACE) {
			ppp = PF_TO_PPP(pf);
			if (file == ppp->owner)
				ppp_shutdown_interface(ppp);
		}
A
Al Viro 已提交
590
		if (atomic_long_read(&file->f_count) <= 2) {
A
Alan Cox 已提交
591
			ppp_release(NULL, file);
L
Linus Torvalds 已提交
592 593
			err = 0;
		} else
A
Al Viro 已提交
594 595
			printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%ld\n",
			       atomic_long_read(&file->f_count));
596
		mutex_unlock(&ppp_mutex);
L
Linus Torvalds 已提交
597 598 599 600
		return err;
	}

	if (pf->kind == CHANNEL) {
A
Alan Cox 已提交
601
		struct channel *pch;
L
Linus Torvalds 已提交
602 603
		struct ppp_channel *chan;

604
		mutex_lock(&ppp_mutex);
A
Alan Cox 已提交
605 606
		pch = PF_TO_CHANNEL(pf);

L
Linus Torvalds 已提交
607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625
		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);
		}
626
		mutex_unlock(&ppp_mutex);
L
Linus Torvalds 已提交
627 628 629 630 631 632 633 634 635
		return err;
	}

	if (pf->kind != INTERFACE) {
		/* can't happen */
		printk(KERN_ERR "PPP: not interface or channel??\n");
		return -EINVAL;
	}

636
	mutex_lock(&ppp_mutex);
L
Linus Torvalds 已提交
637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704
	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);
J
Joe Perches 已提交
705
		if (!vj) {
L
Linus Torvalds 已提交
706 707 708 709 710
			printk(KERN_ERR "PPP: no memory (VJ compressor)\n");
			err = -ENOMEM;
			break;
		}
		ppp_lock(ppp);
J
Joe Perches 已提交
711
		if (ppp->vj)
L
Linus Torvalds 已提交
712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783
			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;
	}
784
	mutex_unlock(&ppp_mutex);
L
Linus Torvalds 已提交
785 786 787
	return err;
}

788 789
static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
			struct file *file, unsigned int cmd, unsigned long arg)
L
Linus Torvalds 已提交
790 791 792 793
{
	int unit, err = -EFAULT;
	struct ppp *ppp;
	struct channel *chan;
794
	struct ppp_net *pn;
L
Linus Torvalds 已提交
795 796
	int __user *p = (int __user *)arg;

797
	mutex_lock(&ppp_mutex);
L
Linus Torvalds 已提交
798 799 800 801 802
	switch (cmd) {
	case PPPIOCNEWUNIT:
		/* Create a new ppp unit */
		if (get_user(unit, p))
			break;
803
		ppp = ppp_create_interface(net, unit, &err);
J
Joe Perches 已提交
804
		if (!ppp)
L
Linus Torvalds 已提交
805 806 807 808 809 810 811 812 813 814 815 816 817 818
			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;
819 820 821
		pn = ppp_pernet(net);
		mutex_lock(&pn->all_ppp_mutex);
		ppp = ppp_find_unit(pn, unit);
J
Joe Perches 已提交
822
		if (ppp) {
L
Linus Torvalds 已提交
823 824 825 826
			atomic_inc(&ppp->file.refcnt);
			file->private_data = &ppp->file;
			err = 0;
		}
827
		mutex_unlock(&pn->all_ppp_mutex);
L
Linus Torvalds 已提交
828 829 830 831 832 833
		break;

	case PPPIOCATTCHAN:
		if (get_user(unit, p))
			break;
		err = -ENXIO;
834 835 836
		pn = ppp_pernet(net);
		spin_lock_bh(&pn->all_channels_lock);
		chan = ppp_find_channel(pn, unit);
J
Joe Perches 已提交
837
		if (chan) {
L
Linus Torvalds 已提交
838 839 840 841
			atomic_inc(&chan->file.refcnt);
			file->private_data = &chan->file;
			err = 0;
		}
842
		spin_unlock_bh(&pn->all_channels_lock);
L
Linus Torvalds 已提交
843 844 845 846 847
		break;

	default:
		err = -ENOTTY;
	}
848
	mutex_unlock(&ppp_mutex);
L
Linus Torvalds 已提交
849 850 851
	return err;
}

852
static const struct file_operations ppp_device_fops = {
L
Linus Torvalds 已提交
853 854 855 856
	.owner		= THIS_MODULE,
	.read		= ppp_read,
	.write		= ppp_write,
	.poll		= ppp_poll,
A
Alan Cox 已提交
857
	.unlocked_ioctl	= ppp_ioctl,
L
Linus Torvalds 已提交
858
	.open		= ppp_open,
859 860
	.release	= ppp_release,
	.llseek		= noop_llseek,
L
Linus Torvalds 已提交
861 862
};

863 864
static __net_init int ppp_init_net(struct net *net)
{
865
	struct ppp_net *pn = net_generic(net, ppp_net_id);
866 867 868 869 870 871 872 873 874 875 876 877 878 879

	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)
{
880
	struct ppp_net *pn = net_generic(net, ppp_net_id);
881 882 883 884

	idr_destroy(&pn->units_idr);
}

A
Alexey Dobriyan 已提交
885
static struct pernet_operations ppp_net_ops = {
886 887
	.init = ppp_init_net,
	.exit = ppp_exit_net,
888 889
	.id   = &ppp_net_id,
	.size = sizeof(struct ppp_net),
890 891
};

L
Linus Torvalds 已提交
892 893 894 895 896 897 898 899 900
#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");
901

902
	err = register_pernet_device(&ppp_net_ops);
903 904 905
	if (err) {
		printk(KERN_ERR "failed to register PPP pernet device (%d)\n", err);
		goto out;
L
Linus Torvalds 已提交
906 907
	}

908 909
	err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
	if (err) {
L
Linus Torvalds 已提交
910
		printk(KERN_ERR "failed to register PPP device (%d)\n", err);
911 912 913 914 915 916 917 918 919 920 921 922 923
		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;
L
Linus Torvalds 已提交
924 925 926

out_chrdev:
	unregister_chrdev(PPP_MAJOR, "ppp");
927
out_net:
928
	unregister_pernet_device(&ppp_net_ops);
929 930
out:
	return err;
L
Linus Torvalds 已提交
931 932 933 934 935
}

/*
 * Network interface unit routines.
 */
936
static netdev_tx_t
L
Linus Torvalds 已提交
937 938
ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
939
	struct ppp *ppp = netdev_priv(dev);
L
Linus Torvalds 已提交
940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961
	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. */
962 963 964
	if (skb_cow_head(skb, PPP_HDRLEN))
		goto outf;

L
Linus Torvalds 已提交
965 966 967 968 969 970 971 972
	pp = skb_push(skb, 2);
	proto = npindex_to_proto[npi];
	pp[0] = proto >> 8;
	pp[1] = proto;

	netif_stop_queue(dev);
	skb_queue_tail(&ppp->file.xq, skb);
	ppp_xmit_process(ppp);
973
	return NETDEV_TX_OK;
L
Linus Torvalds 已提交
974 975 976

 outf:
	kfree_skb(skb);
977
	++dev->stats.tx_dropped;
978
	return NETDEV_TX_OK;
L
Linus Torvalds 已提交
979 980 981 982 983
}

static int
ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
984
	struct ppp *ppp = netdev_priv(dev);
L
Linus Torvalds 已提交
985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000
	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));
J
Joe Perches 已提交
1001
		if (ppp->xc_state)
L
Linus Torvalds 已提交
1002
			ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
J
Joe Perches 已提交
1003
		if (ppp->rc_state)
L
Linus Torvalds 已提交
1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023
			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;
}

S
Stephen Hemminger 已提交
1024
static const struct net_device_ops ppp_netdev_ops = {
1025 1026
	.ndo_start_xmit = ppp_start_xmit,
	.ndo_do_ioctl   = ppp_net_ioctl,
S
Stephen Hemminger 已提交
1027 1028
};

L
Linus Torvalds 已提交
1029 1030
static void ppp_setup(struct net_device *dev)
{
S
Stephen Hemminger 已提交
1031
	dev->netdev_ops = &ppp_netdev_ops;
L
Linus Torvalds 已提交
1032 1033 1034 1035 1036 1037
	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;
1038
	dev->features |= NETIF_F_NETNS_LOCAL;
1039
	dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
L
Linus Torvalds 已提交
1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055
}

/*
 * 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);
1056
	if (!ppp->closing) {
L
Linus Torvalds 已提交
1057
		ppp_push(ppp);
1058 1059
		while (!ppp->xmit_pending &&
		       (skb = skb_dequeue(&ppp->file.xq)))
L
Linus Torvalds 已提交
1060 1061 1062
			ppp_send_frame(ppp, skb);
		/* If there's no work left to do, tell the core net
		   code that we can accept some more. */
J
Joe Perches 已提交
1063
		if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
L
Linus Torvalds 已提交
1064 1065 1066 1067 1068
			netif_wake_queue(ppp->dev);
	}
	ppp_xmit_unlock(ppp);
}

1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118
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;
}

L
Linus Torvalds 已提交
1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137
/*
 * 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;
1138 1139 1140
		if (ppp->pass_filter &&
		    sk_run_filter(skb, ppp->pass_filter,
				  ppp->pass_len) == 0) {
L
Linus Torvalds 已提交
1141 1142 1143 1144 1145 1146
			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 */
1147 1148 1149
		if (!(ppp->active_filter &&
		      sk_run_filter(skb, ppp->active_filter,
				    ppp->active_len) == 0))
L
Linus Torvalds 已提交
1150 1151 1152 1153 1154 1155 1156 1157
			ppp->last_xmit = jiffies;
		skb_pull(skb, 2);
#else
		/* for data packets, record the time */
		ppp->last_xmit = jiffies;
#endif /* CONFIG_PPP_FILTER */
	}

1158 1159
	++ppp->dev->stats.tx_packets;
	ppp->dev->stats.tx_bytes += skb->len - 2;
L
Linus Torvalds 已提交
1160 1161 1162

	switch (proto) {
	case PPP_IP:
J
Joe Perches 已提交
1163
		if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
L
Linus Torvalds 已提交
1164 1165 1166 1167
			break;
		/* try to do VJ TCP header compression */
		new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
				    GFP_ATOMIC);
J
Joe Perches 已提交
1168
		if (!new_skb) {
L
Linus Torvalds 已提交
1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202
			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 */
1203 1204
	if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state &&
	    proto != PPP_LCP && proto != PPP_CCP) {
1205 1206 1207
		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");
L
Linus Torvalds 已提交
1208 1209
			goto drop;
		}
1210 1211 1212
		skb = pad_compress_skb(ppp, skb);
		if (!skb)
			goto drop;
L
Linus Torvalds 已提交
1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231
	}

	/*
	 * 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:
1232
	kfree_skb(skb);
1233
	++ppp->dev->stats.tx_errors;
L
Linus Torvalds 已提交
1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246
}

/*
 * 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;

J
Joe Perches 已提交
1247
	if (!skb)
L
Linus Torvalds 已提交
1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293
		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)
{
1294 1295 1296 1297 1298 1299 1300
	int len, totlen;
	int i, bits, hdrlen, mtu;
	int flen;
	int navail, nfree, nzero;
	int nbigger;
	int totspeed;
	int totfree;
L
Linus Torvalds 已提交
1301 1302 1303 1304 1305 1306
	unsigned char *p, *q;
	struct list_head *list;
	struct channel *pch;
	struct sk_buff *frag;
	struct ppp_channel *chan;

1307
	totspeed = 0; /*total bitrate of the bundle*/
1308 1309 1310 1311
	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
1312 1313 1314
				  *having no queued packets before
				  *starting the fragmentation*/

L
Linus Torvalds 已提交
1315
	hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1316 1317
	i = 0;
	list_for_each_entry(pch, &ppp->channels, clist) {
1318 1319 1320 1321 1322 1323 1324
		if (pch->chan) {
			pch->avail = 1;
			navail++;
			pch->speed = pch->chan->speed;
		} else {
			pch->avail = 0;
		}
1325
		if (pch->avail) {
1326
			if (skb_queue_empty(&pch->file.xq) ||
1327
				!pch->had_frag) {
1328 1329 1330 1331 1332 1333 1334 1335 1336
					if (pch->speed == 0)
						nzero++;
					else
						totspeed += pch->speed;

					pch->avail = 2;
					++nfree;
					++totfree;
				}
1337 1338
			if (!pch->had_frag && i < ppp->nxchan)
				ppp->nxchan = i;
L
Linus Torvalds 已提交
1339
		}
1340
		++i;
L
Linus Torvalds 已提交
1341
	}
1342
	/*
1343 1344 1345
	 * 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.
1346
	 */
1347 1348
	if (nfree == 0 || nfree < navail / 2)
		return 0; /* can't take now, leave it in xmit_pending */
L
Linus Torvalds 已提交
1349 1350

	/* Do protocol field compression (XXX this should be optional) */
1351 1352
	p = skb->data;
	len = skb->len;
L
Linus Torvalds 已提交
1353 1354 1355 1356 1357
	if (*p == 0) {
		++p;
		--len;
	}

1358
	totlen = len;
1359
	nbigger = len % nfree;
1360

1361 1362
	/* skip to the channel after the one we last used
	   and start at that one */
1363
	list = &ppp->channels;
1364
	for (i = 0; i < ppp->nxchan; ++i) {
L
Linus Torvalds 已提交
1365
		list = list->next;
1366 1367
		if (list == &ppp->channels) {
			i = 0;
L
Linus Torvalds 已提交
1368 1369 1370 1371
			break;
		}
	}

1372
	/* create a fragment for each channel */
L
Linus Torvalds 已提交
1373
	bits = B;
1374
	while (len > 0) {
L
Linus Torvalds 已提交
1375
		list = list->next;
1376 1377
		if (list == &ppp->channels) {
			i = 0;
L
Linus Torvalds 已提交
1378 1379
			continue;
		}
1380
		pch = list_entry(list, struct channel, clist);
L
Linus Torvalds 已提交
1381 1382 1383 1384
		++i;
		if (!pch->avail)
			continue;

1385
		/*
1386 1387
		 * Skip this channel if it has a fragment pending already and
		 * we haven't given a fragment to all of the free channels.
1388 1389
		 */
		if (pch->avail == 1) {
1390
			if (nfree > 0)
1391 1392 1393 1394 1395
				continue;
		} else {
			pch->avail = 1;
		}

L
Linus Torvalds 已提交
1396 1397
		/* check the channel's mtu and whether it is still attached. */
		spin_lock_bh(&pch->downl);
1398
		if (pch->chan == NULL) {
1399
			/* can't use this channel, it's being deregistered */
1400 1401 1402
			if (pch->speed == 0)
				nzero--;
			else
1403
				totspeed -= pch->speed;
1404

L
Linus Torvalds 已提交
1405 1406
			spin_unlock_bh(&pch->downl);
			pch->avail = 0;
1407 1408 1409
			totlen = len;
			totfree--;
			nfree--;
1410
			if (--navail == 0)
L
Linus Torvalds 已提交
1411 1412 1413 1414 1415
				break;
			continue;
		}

		/*
1416
		*if the channel speed is not set divide
1417
		*the packet evenly among the free channels;
1418 1419 1420
		*otherwise divide it according to the speed
		*of the channel we are going to transmit on
		*/
1421
		flen = len;
1422 1423
		if (nfree > 0) {
			if (pch->speed == 0) {
1424
				flen = len/nfree;
1425 1426 1427 1428 1429 1430 1431 1432 1433 1434
				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)/
1435
							totspeed;
1436
				}
1437
			}
1438
			nfree--;
1439 1440 1441
		}

		/*
1442 1443
		 *check if we are on the last channel or
		 *we exceded the lenght of the data to
1444 1445
		 *fragment
		 */
1446
		if ((nfree <= 0) || (flen > len))
1447 1448 1449 1450 1451 1452
			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
L
Linus Torvalds 已提交
1453
		 */
1454
		if (flen <= 0) {
1455 1456 1457 1458 1459
			pch->avail = 2;
			spin_unlock_bh(&pch->downl);
			continue;
		}

1460 1461 1462
		mtu = pch->chan->mtu - hdrlen;
		if (mtu < 4)
			mtu = 4;
1463 1464
		if (flen > mtu)
			flen = mtu;
1465 1466 1467
		if (flen == len)
			bits |= E;
		frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
J
Joe Perches 已提交
1468
		if (!frag)
1469
			goto noskb;
1470
		q = skb_put(frag, flen + hdrlen);
1471

1472
		/* make the MP header */
1473 1474 1475
		q[0] = PPP_MP >> 8;
		q[1] = PPP_MP;
		if (ppp->flags & SC_MP_XSHORTSEQ) {
1476
			q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1477 1478 1479 1480 1481 1482
			q[3] = ppp->nxseq;
		} else {
			q[2] = bits;
			q[3] = ppp->nxseq >> 16;
			q[4] = ppp->nxseq >> 8;
			q[5] = ppp->nxseq;
L
Linus Torvalds 已提交
1483
		}
1484

1485
		memcpy(q + hdrlen, p, flen);
1486 1487 1488

		/* try to send it down the channel */
		chan = pch->chan;
1489
		if (!skb_queue_empty(&pch->file.xq) ||
1490
			!chan->ops->start_xmit(chan, frag))
1491
			skb_queue_tail(&pch->file.xq, frag);
1492
		pch->had_frag = 1;
1493
		p += flen;
1494
		len -= flen;
1495 1496
		++ppp->nxseq;
		bits = 0;
L
Linus Torvalds 已提交
1497
		spin_unlock_bh(&pch->downl);
1498
	}
1499
	ppp->nxchan = i;
L
Linus Torvalds 已提交
1500 1501 1502 1503 1504 1505

	return 1;

 noskb:
	spin_unlock_bh(&pch->downl);
	if (ppp->debug & 1)
1506
		printk(KERN_ERR "PPP: no memory (fragment)\n");
1507
	++ppp->dev->stats.tx_errors;
L
Linus Torvalds 已提交
1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522
	++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);
J
Joe Perches 已提交
1523
	if (pch->chan) {
1524
		while (!skb_queue_empty(&pch->file.xq)) {
L
Linus Torvalds 已提交
1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537
			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 */
1538
	if (skb_queue_empty(&pch->file.xq)) {
L
Linus Torvalds 已提交
1539 1540
		read_lock_bh(&pch->upl);
		ppp = pch->ppp;
J
Joe Perches 已提交
1541
		if (ppp)
L
Linus Torvalds 已提交
1542 1543 1544 1545 1546 1547 1548 1549 1550
			ppp_xmit_process(ppp);
		read_unlock_bh(&pch->upl);
	}
}

/*
 * Receive-side routines.
 */

1551 1552 1553 1554 1555
struct ppp_mp_skb_parm {
	u32		sequence;
	u8		BEbits;
};
#define PPP_MP_CB(skb)	((struct ppp_mp_skb_parm *)((skb)->cb))
L
Linus Torvalds 已提交
1556 1557 1558 1559 1560

static inline void
ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
{
	ppp_recv_lock(ppp);
1561
	if (!ppp->closing)
L
Linus Torvalds 已提交
1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573
		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;

1574
	if (!pch) {
L
Linus Torvalds 已提交
1575 1576 1577
		kfree_skb(skb);
		return;
	}
1578

L
Linus Torvalds 已提交
1579
	read_lock_bh(&pch->upl);
1580 1581 1582 1583 1584 1585 1586 1587 1588 1589
	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);
J
Joe Perches 已提交
1590
	if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
L
Linus Torvalds 已提交
1591 1592 1593
		/* put it on the channel queue */
		skb_queue_tail(&pch->file.rq, skb);
		/* drop old frames if queue too long */
1594 1595
		while (pch->file.rq.qlen > PPP_MAX_RQLEN &&
		       (skb = skb_dequeue(&pch->file.rq)))
L
Linus Torvalds 已提交
1596 1597 1598 1599 1600
			kfree_skb(skb);
		wake_up_interruptible(&pch->file.rwait);
	} else {
		ppp_do_recv(pch->ppp, skb, pch);
	}
1601 1602

done:
L
Linus Torvalds 已提交
1603 1604 1605 1606 1607 1608 1609 1610 1611 1612
	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;

J
Joe Perches 已提交
1613
	if (!pch)
L
Linus Torvalds 已提交
1614 1615 1616
		return;

	read_lock_bh(&pch->upl);
J
Joe Perches 已提交
1617
	if (pch->ppp) {
L
Linus Torvalds 已提交
1618
		skb = alloc_skb(0, GFP_ATOMIC);
J
Joe Perches 已提交
1619
		if (skb) {
L
Linus Torvalds 已提交
1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634
			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)
{
1635 1636
	/* note: a 0-length skb is used as an error indication */
	if (skb->len > 0) {
L
Linus Torvalds 已提交
1637 1638 1639 1640 1641 1642 1643
#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);
1644 1645 1646
	} else {
		kfree_skb(skb);
		ppp_receive_error(ppp);
L
Linus Torvalds 已提交
1647 1648 1649 1650 1651 1652
	}
}

static void
ppp_receive_error(struct ppp *ppp)
{
1653
	++ppp->dev->stats.rx_errors;
J
Joe Perches 已提交
1654
	if (ppp->vj)
L
Linus Torvalds 已提交
1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668
		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.
	 */
1669 1670
	if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) &&
	    (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
L
Linus Torvalds 已提交
1671 1672
		skb = ppp_decompress_frame(ppp, skb);

1673 1674 1675
	if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
		goto err;

L
Linus Torvalds 已提交
1676 1677 1678 1679
	proto = PPP_PROTO(skb);
	switch (proto) {
	case PPP_VJC_COMP:
		/* decompress VJ compressed packets */
J
Joe Perches 已提交
1680
		if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
L
Linus Torvalds 已提交
1681 1682
			goto err;

1683
		if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
L
Linus Torvalds 已提交
1684 1685
			/* copy to a new sk_buff with more tailroom */
			ns = dev_alloc_skb(skb->len + 128);
J
Joe Perches 已提交
1686
			if (!ns) {
L
Linus Torvalds 已提交
1687 1688 1689 1690 1691 1692 1693 1694
				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;
		}
1695 1696
		else
			skb->ip_summed = CHECKSUM_NONE;
L
Linus Torvalds 已提交
1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711

		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:
J
Joe Perches 已提交
1712
		if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
L
Linus Torvalds 已提交
1713
			goto err;
1714

L
Linus Torvalds 已提交
1715 1716 1717
		/* Until we fix the decompressor need to make sure
		 * data portion is linear.
		 */
1718
		if (!pskb_may_pull(skb, skb->len))
L
Linus Torvalds 已提交
1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732
			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;
	}

1733 1734
	++ppp->dev->stats.rx_packets;
	ppp->dev->stats.rx_bytes += skb->len - 2;
L
Linus Torvalds 已提交
1735 1736 1737 1738 1739 1740

	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 */
1741 1742
		while (ppp->file.rq.qlen > PPP_MAX_RQLEN &&
		       (skb = skb_dequeue(&ppp->file.rq)))
L
Linus Torvalds 已提交
1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753
			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 */
1754 1755 1756 1757 1758 1759
		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;
1760 1761 1762
			if (ppp->pass_filter &&
			    sk_run_filter(skb, ppp->pass_filter,
					  ppp->pass_len) == 0) {
1763 1764 1765 1766 1767 1768
				if (ppp->debug & 1)
					printk(KERN_DEBUG "PPP: inbound frame "
					       "not passed\n");
				kfree_skb(skb);
				return;
			}
1769 1770 1771
			if (!(ppp->active_filter &&
			      sk_run_filter(skb, ppp->active_filter,
					    ppp->active_len) == 0))
1772 1773 1774
				ppp->last_recv = jiffies;
			__skb_pull(skb, 2);
		} else
L
Linus Torvalds 已提交
1775
#endif /* CONFIG_PPP_FILTER */
1776
			ppp->last_recv = jiffies;
L
Linus Torvalds 已提交
1777

1778 1779
		if ((ppp->dev->flags & IFF_UP) == 0 ||
		    ppp->npmode[npi] != NPMODE_PASS) {
L
Linus Torvalds 已提交
1780 1781
			kfree_skb(skb);
		} else {
1782 1783
			/* chop off protocol */
			skb_pull_rcsum(skb, 2);
L
Linus Torvalds 已提交
1784 1785
			skb->dev = ppp->dev;
			skb->protocol = htons(npindex_to_ethertype[npi]);
1786
			skb_reset_mac_header(skb);
L
Linus Torvalds 已提交
1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810
			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) {
1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822
		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);
J
Joe Perches 已提交
1823
		if (!ns) {
L
Linus Torvalds 已提交
1824 1825 1826 1827 1828
			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,
1829
				skb->len + 2, ns->data, obuff_size);
L
Linus Torvalds 已提交
1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869
		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;
1870
	struct channel *ch;
L
Linus Torvalds 已提交
1871 1872
	int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;

1873
	if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
L
Linus Torvalds 已提交
1874 1875 1876 1877 1878 1879 1880 1881 1882 1883
		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;
	}
1884
	PPP_MP_CB(skb)->BEbits = skb->data[2];
L
Linus Torvalds 已提交
1885 1886 1887 1888 1889
	skb_pull(skb, mphdrlen);	/* pull off PPP and MP headers */

	/*
	 * Do protocol ID decompression on the first fragment of each packet.
	 */
1890
	if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1))
L
Linus Torvalds 已提交
1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901
		*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 */
1902
	PPP_MP_CB(skb)->sequence = seq;
L
Linus Torvalds 已提交
1903 1904 1905 1906 1907 1908 1909 1910
	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);
1911
		++ppp->dev->stats.rx_dropped;
L
Linus Torvalds 已提交
1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923
		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.
	 */
1924
	list_for_each_entry(ch, &ppp->channels, clist) {
L
Linus Torvalds 已提交
1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935
		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. */
1936
	if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
1937
		struct sk_buff *mskb = skb_peek(&ppp->mrq);
1938 1939
		if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence))
			ppp->minseq = PPP_MP_CB(mskb)->sequence;
1940
	}
L
Linus Torvalds 已提交
1941 1942

	/* Pull completed packets off the queue and receive them. */
1943 1944 1945 1946 1947 1948 1949 1950 1951
	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);
		}
	}
L
Linus Torvalds 已提交
1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968

	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;
1969
	u32 seq = PPP_MP_CB(skb)->sequence;
L
Linus Torvalds 已提交
1970 1971 1972

	/* N.B. we don't need to lock the list lock because we have the
	   ppp unit receive-side lock. */
1973
	skb_queue_walk(list, p) {
1974
		if (seq_before(seq, PPP_MP_CB(p)->sequence))
L
Linus Torvalds 已提交
1975
			break;
1976
	}
1977
	__skb_queue_before(list, p, skb);
L
Linus Torvalds 已提交
1978 1979 1980 1981 1982 1983 1984 1985
}

/*
 * 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.
 */
S
Stephen Hemminger 已提交
1986
static struct sk_buff *
L
Linus Torvalds 已提交
1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002
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;
2003
		if (seq_before(PPP_MP_CB(p)->sequence, seq)) {
L
Linus Torvalds 已提交
2004 2005
			/* this can't happen, anyway ignore the skb */
			printk(KERN_ERR "ppp_mp_reconstruct bad seq %u < %u\n",
2006
			       PPP_MP_CB(p)->sequence, seq);
L
Linus Torvalds 已提交
2007 2008 2009
			head = next;
			continue;
		}
2010
		if (PPP_MP_CB(p)->sequence != seq) {
L
Linus Torvalds 已提交
2011 2012 2013 2014 2015 2016
			/* 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;
2017 2018
			seq = seq_before(minseq, PPP_MP_CB(p)->sequence)?
				minseq + 1: PPP_MP_CB(p)->sequence;
L
Linus Torvalds 已提交
2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031
			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 */
2032
		if (PPP_MP_CB(p)->BEbits & B) {
L
Linus Torvalds 已提交
2033 2034 2035 2036 2037 2038 2039 2040
			head = p;
			lost = 0;
			len = 0;
		}

		len += p->len;

		/* Got a complete packet yet? */
2041 2042
		if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) &&
		    (PPP_MP_CB(head)->BEbits & B)) {
L
Linus Torvalds 已提交
2043
			if (len > ppp->mrru + 2) {
2044
				++ppp->dev->stats.rx_length_errors;
L
Linus Torvalds 已提交
2045 2046 2047 2048 2049 2050 2051 2052
				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) {
2053
				++ppp->dev->stats.rx_missed_errors;
L
Linus Torvalds 已提交
2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067
				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.
		 */
2068
		if (PPP_MP_CB(p)->BEbits & E)
L
Linus Torvalds 已提交
2069 2070 2071 2072 2073 2074 2075 2076 2077
			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. */
2078
		if (PPP_MP_CB(head)->sequence != ppp->nextseq) {
L
Linus Torvalds 已提交
2079 2080
			if (ppp->debug & 1)
				printk(KERN_DEBUG "  missed pkts %u..%u\n",
2081 2082
				       ppp->nextseq,
				       PPP_MP_CB(head)->sequence-1);
2083
			++ppp->dev->stats.rx_dropped;
L
Linus Torvalds 已提交
2084 2085 2086 2087 2088 2089 2090
			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);
2091
		ppp->nextseq = PPP_MP_CB(tail)->sequence + 1;
L
Linus Torvalds 已提交
2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109
		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.
 */

2110 2111 2112 2113 2114 2115 2116 2117
/* 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)
L
Linus Torvalds 已提交
2118 2119
{
	struct channel *pch;
2120
	struct ppp_net *pn;
L
Linus Torvalds 已提交
2121

2122
	pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
J
Joe Perches 已提交
2123
	if (!pch)
L
Linus Torvalds 已提交
2124
		return -ENOMEM;
2125 2126 2127

	pn = ppp_pernet(net);

L
Linus Torvalds 已提交
2128 2129
	pch->ppp = NULL;
	pch->chan = chan;
2130
	pch->chan_net = net;
L
Linus Torvalds 已提交
2131 2132 2133 2134 2135 2136 2137 2138 2139
	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);
2140 2141 2142 2143

	spin_lock_bh(&pn->all_channels_lock);
	pch->file.index = ++pn->last_channel_index;
	list_add(&pch->list, &pn->new_channels);
L
Linus Torvalds 已提交
2144
	atomic_inc(&channel_count);
2145 2146
	spin_unlock_bh(&pn->all_channels_lock);

L
Linus Torvalds 已提交
2147 2148 2149 2150 2151 2152 2153 2154 2155 2156
	return 0;
}

/*
 * Return the index of a channel.
 */
int ppp_channel_index(struct ppp_channel *chan)
{
	struct channel *pch = chan->ppp;

J
Joe Perches 已提交
2157
	if (pch)
L
Linus Torvalds 已提交
2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169
		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;

J
Joe Perches 已提交
2170
	if (pch) {
L
Linus Torvalds 已提交
2171
		read_lock_bh(&pch->upl);
J
Joe Perches 已提交
2172
		if (pch->ppp)
L
Linus Torvalds 已提交
2173 2174 2175 2176 2177 2178
			unit = pch->ppp->file.index;
		read_unlock_bh(&pch->upl);
	}
	return unit;
}

2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196
/*
 * 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;
}


L
Linus Torvalds 已提交
2197 2198 2199 2200 2201 2202 2203 2204
/*
 * 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;
2205
	struct ppp_net *pn;
L
Linus Torvalds 已提交
2206

J
Joe Perches 已提交
2207
	if (!pch)
L
Linus Torvalds 已提交
2208
		return;		/* should never happen */
2209

L
Linus Torvalds 已提交
2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221
	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);
2222 2223 2224

	pn = ppp_pernet(pch->chan_net);
	spin_lock_bh(&pn->all_channels_lock);
L
Linus Torvalds 已提交
2225
	list_del(&pch->list);
2226 2227
	spin_unlock_bh(&pn->all_channels_lock);

L
Linus Torvalds 已提交
2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242
	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;

J
Joe Perches 已提交
2243
	if (!pch)
L
Linus Torvalds 已提交
2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262
		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;
2263 2264 2265
	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)))
L
Linus Torvalds 已提交
2266 2267
		goto out;
	err = -EINVAL;
2268 2269
	if (data.length > CCP_MAX_OPTION_LENGTH ||
	    ccp_option[1] < 2 || ccp_option[1] > data.length)
L
Linus Torvalds 已提交
2270 2271
		goto out;

J
Johannes Berg 已提交
2272 2273 2274
	cp = try_then_request_module(
		find_compressor(ccp_option[0]),
		"ppp-compress-%d", ccp_option[0]);
J
Joe Perches 已提交
2275
	if (!cp)
L
Linus Torvalds 已提交
2276 2277 2278 2279 2280
		goto out;

	err = -ENOBUFS;
	if (data.transmit) {
		state = cp->comp_alloc(ccp_option, data.length);
J
Joe Perches 已提交
2281
		if (state) {
L
Linus Torvalds 已提交
2282 2283 2284 2285 2286 2287 2288
			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);
J
Joe Perches 已提交
2289
			if (ostate) {
L
Linus Torvalds 已提交
2290 2291 2292 2293 2294 2295 2296 2297 2298
				ocomp->comp_free(ostate);
				module_put(ocomp->owner);
			}
			err = 0;
		} else
			module_put(cp->owner);

	} else {
		state = cp->decomp_alloc(ccp_option, data.length);
J
Joe Perches 已提交
2299
		if (state) {
L
Linus Torvalds 已提交
2300 2301 2302 2303 2304 2305 2306
			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);
J
Joe Perches 已提交
2307
			if (ostate) {
L
Linus Torvalds 已提交
2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336
				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:

2337
		/* A ConfReq starts negotiation of compression
L
Linus Torvalds 已提交
2338 2339 2340 2341 2342 2343 2344 2345 2346
		 * 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;
2347
		else
L
Linus Torvalds 已提交
2348 2349
			/* I am proposing to what he should send */
			ppp->rstate &= ~SC_DECOMP_RUN;
2350

L
Linus Torvalds 已提交
2351
		break;
2352

L
Linus Torvalds 已提交
2353 2354 2355
	case CCP_TERMREQ:
	case CCP_TERMACK:
		/*
2356
		 * CCP is going down, both directions of transmission
L
Linus Torvalds 已提交
2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373
		 */
		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 */
J
Joe Perches 已提交
2374
			if (!ppp->rc_state)
L
Linus Torvalds 已提交
2375 2376 2377 2378 2379 2380 2381 2382
				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 */
J
Joe Perches 已提交
2383
			if (!ppp->xc_state)
L
Linus Torvalds 已提交
2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450
				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;

2451
	list_for_each_entry(ce, &compressor_list, list) {
L
Linus Torvalds 已提交
2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465
		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;
J
Joe Perches 已提交
2466
	if (find_comp_entry(cp->compress_proto))
L
Linus Torvalds 已提交
2467 2468 2469
		goto out;
	ret = -ENOMEM;
	ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
J
Joe Perches 已提交
2470
	if (!ce)
L
Linus Torvalds 已提交
2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487
		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);
J
Joe Perches 已提交
2488
	if (ce && ce->comp == cp) {
L
Linus Torvalds 已提交
2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503
		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);
J
Joe Perches 已提交
2504
	if (ce) {
L
Linus Torvalds 已提交
2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522
		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));
2523 2524 2525 2526 2527 2528
	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;
J
Joe Perches 已提交
2529
	if (!vj)
L
Linus Torvalds 已提交
2530 2531 2532 2533 2534 2535 2536 2537 2538 2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551
		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 *
2552
ppp_create_interface(struct net *net, int unit, int *retp)
L
Linus Torvalds 已提交
2553 2554
{
	struct ppp *ppp;
2555
	struct ppp_net *pn;
L
Linus Torvalds 已提交
2556 2557 2558 2559
	struct net_device *dev = NULL;
	int ret = -ENOMEM;
	int i;

2560
	dev = alloc_netdev(sizeof(struct ppp), "", ppp_setup);
L
Linus Torvalds 已提交
2561 2562 2563
	if (!dev)
		goto out1;

2564 2565
	pn = ppp_pernet(net);

2566 2567
	ppp = netdev_priv(dev);
	ppp->dev = dev;
L
Linus Torvalds 已提交
2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580
	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 */

2581 2582 2583 2584 2585 2586 2587
	/*
	 * drum roll: don't forget to set
	 * the net device is belong to
	 */
	dev_net_set(dev, net);

	mutex_lock(&pn->all_ppp_mutex);
2588 2589

	if (unit < 0) {
2590
		unit = unit_get(&pn->units_idr, ppp);
2591
		if (unit < 0) {
2592
			ret = unit;
2593 2594 2595
			goto out2;
		}
	} else {
2596
		ret = -EEXIST;
2597
		if (unit_find(&pn->units_idr, unit))
2598
			goto out2; /* unit already exists */
2599 2600 2601 2602 2603 2604 2605 2606 2607
		/*
		 * 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 :)
		 */
2608
		unit = unit_set(&pn->units_idr, ppp, unit);
2609
		if (unit < 0)
2610 2611
			goto out2;
	}
L
Linus Torvalds 已提交
2612 2613 2614 2615 2616 2617 2618

	/* Initialize the new ppp unit */
	ppp->file.index = unit;
	sprintf(dev->name, "ppp%d", unit);

	ret = register_netdev(dev);
	if (ret != 0) {
2619
		unit_put(&pn->units_idr, unit);
L
Linus Torvalds 已提交
2620 2621 2622 2623 2624
		printk(KERN_ERR "PPP: couldn't register device %s (%d)\n",
		       dev->name, ret);
		goto out2;
	}

2625 2626
	ppp->ppp_net = net;

L
Linus Torvalds 已提交
2627
	atomic_inc(&ppp_unit_count);
2628
	mutex_unlock(&pn->all_ppp_mutex);
2629

L
Linus Torvalds 已提交
2630 2631 2632 2633
	*retp = 0;
	return ppp;

out2:
2634
	mutex_unlock(&pn->all_ppp_mutex);
L
Linus Torvalds 已提交
2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659
	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)
{
2660 2661 2662 2663 2664
	struct ppp_net *pn;

	pn = ppp_pernet(ppp->ppp_net);
	mutex_lock(&pn->all_ppp_mutex);

L
Linus Torvalds 已提交
2665
	/* This will call dev_close() for us. */
2666 2667 2668 2669 2670
	ppp_lock(ppp);
	if (!ppp->closing) {
		ppp->closing = 1;
		ppp_unlock(ppp);
		unregister_netdev(ppp->dev);
2671
		unit_put(&pn->units_idr, ppp->file.index);
2672 2673 2674
	} else
		ppp_unlock(ppp);

L
Linus Torvalds 已提交
2675 2676 2677
	ppp->file.dead = 1;
	ppp->owner = NULL;
	wake_up_interruptible(&ppp->file.rwait);
2678 2679

	mutex_unlock(&pn->all_ppp_mutex);
L
Linus Torvalds 已提交
2680 2681 2682 2683 2684 2685 2686 2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 2698 2699 2700 2701 2702 2703 2704 2705 2706 2707 2708 2709
}

/*
 * 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
2710 2711 2712 2713
	kfree(ppp->pass_filter);
	ppp->pass_filter = NULL;
	kfree(ppp->active_filter);
	ppp->active_filter = NULL;
L
Linus Torvalds 已提交
2714 2715
#endif /* CONFIG_PPP_FILTER */

2716
	kfree_skb(ppp->xmit_pending);
2717

2718
	free_netdev(ppp->dev);
L
Linus Torvalds 已提交
2719 2720 2721 2722
}

/*
 * Locate an existing ppp unit.
2723
 * The caller should have locked the all_ppp_mutex.
L
Linus Torvalds 已提交
2724 2725
 */
static struct ppp *
2726
ppp_find_unit(struct ppp_net *pn, int unit)
L
Linus Torvalds 已提交
2727
{
2728
	return unit_find(&pn->units_idr, unit);
L
Linus Torvalds 已提交
2729 2730 2731 2732 2733 2734 2735 2736 2737 2738 2739
}

/*
 * 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 *
2740
ppp_find_channel(struct ppp_net *pn, int unit)
L
Linus Torvalds 已提交
2741 2742 2743
{
	struct channel *pch;

2744
	list_for_each_entry(pch, &pn->new_channels, list) {
L
Linus Torvalds 已提交
2745
		if (pch->file.index == unit) {
2746
			list_move(&pch->list, &pn->all_channels);
L
Linus Torvalds 已提交
2747 2748 2749
			return pch;
		}
	}
2750 2751

	list_for_each_entry(pch, &pn->all_channels, list) {
L
Linus Torvalds 已提交
2752 2753 2754
		if (pch->file.index == unit)
			return pch;
	}
2755

L
Linus Torvalds 已提交
2756 2757 2758 2759 2760 2761 2762 2763 2764 2765
	return NULL;
}

/*
 * Connect a PPP channel to a PPP interface unit.
 */
static int
ppp_connect_channel(struct channel *pch, int unit)
{
	struct ppp *ppp;
2766
	struct ppp_net *pn;
L
Linus Torvalds 已提交
2767 2768 2769
	int ret = -ENXIO;
	int hdrlen;

2770 2771 2772 2773
	pn = ppp_pernet(pch->chan_net);

	mutex_lock(&pn->all_ppp_mutex);
	ppp = ppp_find_unit(pn, unit);
J
Joe Perches 已提交
2774
	if (!ppp)
L
Linus Torvalds 已提交
2775 2776 2777
		goto out;
	write_lock_bh(&pch->upl);
	ret = -EINVAL;
J
Joe Perches 已提交
2778
	if (pch->ppp)
L
Linus Torvalds 已提交
2779 2780 2781 2782 2783 2784
		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 */
2785
	if (hdrlen > ppp->dev->hard_header_len)
L
Linus Torvalds 已提交
2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796
		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:
2797
	mutex_unlock(&pn->all_ppp_mutex);
L
Linus Torvalds 已提交
2798 2799 2800 2801 2802 2803 2804 2805 2806 2807 2808 2809 2810 2811 2812 2813
	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);
J
Joe Perches 已提交
2814
	if (ppp) {
L
Linus Torvalds 已提交
2815 2816 2817 2818 2819 2820 2821 2822 2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850
		/* 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" */
		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");
2851
	unregister_chrdev(PPP_MAJOR, "ppp");
2852
	device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
2853
	class_destroy(ppp_class);
2854
	unregister_pernet_device(&ppp_net_ops);
L
Linus Torvalds 已提交
2855 2856 2857
}

/*
2858 2859
 * Units handling. Caller must protect concurrent access
 * by holding all_ppp_mutex
L
Linus Torvalds 已提交
2860
 */
2861

2862
static int __unit_alloc(struct idr *p, void *ptr, int n)
2863 2864 2865 2866 2867 2868 2869 2870 2871 2872
{
	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);
2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885
	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;
2886

2887 2888 2889 2890
	unit = __unit_alloc(p, ptr, n);
	if (unit < 0)
		return unit;
	else if (unit != n) {
2891 2892 2893 2894 2895 2896 2897
		idr_remove(p, unit);
		return -EINVAL;
	}

	return unit;
}

2898 2899
/* get new free unit number and associate pointer with it */
static int unit_get(struct idr *p, void *ptr)
L
Linus Torvalds 已提交
2900
{
2901
	return __unit_alloc(p, ptr, 0);
L
Linus Torvalds 已提交
2902 2903
}

2904 2905
/* put unit number back to a pool */
static void unit_put(struct idr *p, int n)
L
Linus Torvalds 已提交
2906
{
2907
	idr_remove(p, n);
L
Linus Torvalds 已提交
2908 2909
}

2910 2911
/* get pointer associated with the number */
static void *unit_find(struct idr *p, int n)
L
Linus Torvalds 已提交
2912
{
2913
	return idr_find(p, n);
L
Linus Torvalds 已提交
2914 2915 2916 2917 2918 2919 2920
}

/* Module/initialization stuff */

module_init(ppp_init);
module_exit(ppp_cleanup);

2921
EXPORT_SYMBOL(ppp_register_net_channel);
L
Linus Torvalds 已提交
2922 2923 2924 2925
EXPORT_SYMBOL(ppp_register_channel);
EXPORT_SYMBOL(ppp_unregister_channel);
EXPORT_SYMBOL(ppp_channel_index);
EXPORT_SYMBOL(ppp_unit_number);
2926
EXPORT_SYMBOL(ppp_dev_name);
L
Linus Torvalds 已提交
2927 2928 2929 2930 2931 2932
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");
2933 2934
MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
MODULE_ALIAS("devname:ppp");