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gianfar: Fix soft lockup with multi-interrupt TSECs
[net-next-2.6.git] / drivers / net / ppp_generic.c
CommitLineData
1da177e4
LT		 1/*
2 * Generic PPP layer for Linux.
3 *
4 * Copyright 1999-2002 Paul Mackerras.
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 *
11 * The generic PPP layer handles the PPP network interfaces, the
12 * /dev/ppp device, packet and VJ compression, and multilink.
13 * It talks to PPP `channels' via the interface defined in
14 * include/linux/ppp_channel.h. Channels provide the basic means for
15 * sending and receiving PPP frames on some kind of communications
16 * channel.
17 *
18 * Part of the code in this driver was inspired by the old async-only
19 * PPP driver, written by Michael Callahan and Al Longyear, and
20 * subsequently hacked by Paul Mackerras.
21 *
22 * ==FILEVERSION 20041108==
23 */
24
1da177e4
LT		 25#include <linux/module.h>
26#include <linux/kernel.h>
27#include <linux/kmod.h>
28#include <linux/init.h>
29#include <linux/list.h>
7a95d267 30#include <linux/idr.h>
1da177e4
LT		 31#include <linux/netdevice.h>
32#include <linux/poll.h>
33#include <linux/ppp_defs.h>
34#include <linux/filter.h>
35#include <linux/if_ppp.h>
36#include <linux/ppp_channel.h>
37#include <linux/ppp-comp.h>
38#include <linux/skbuff.h>
39#include <linux/rtnetlink.h>
40#include <linux/if_arp.h>
41#include <linux/ip.h>
42#include <linux/tcp.h>
f2b9857e 43#include <linux/smp_lock.h>
1da177e4 44#include <linux/spinlock.h>
1da177e4
LT		 45#include <linux/rwsem.h>
46#include <linux/stddef.h>
47#include <linux/device.h>
8ed965d6 48#include <linux/mutex.h>
1da177e4
LT		 49#include <net/slhc_vj.h>
50#include <asm/atomic.h>
51
52#define PPP_VERSION "2.4.2"
53
54/*
55 * Network protocols we support.
56 */
57#define NP_IP 0 /* Internet Protocol V4 */
58#define NP_IPV6 1 /* Internet Protocol V6 */
59#define NP_IPX 2 /* IPX protocol */
60#define NP_AT 3 /* Appletalk protocol */
61#define NP_MPLS_UC 4 /* MPLS unicast */
62#define NP_MPLS_MC 5 /* MPLS multicast */
63#define NUM_NP 6 /* Number of NPs. */
64
65#define MPHDRLEN 6 /* multilink protocol header length */
66#define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */
67#define MIN_FRAG_SIZE 64
68
69/*
70 * An instance of /dev/ppp can be associated with either a ppp
71 * interface unit or a ppp channel. In both cases, file->private_data
72 * points to one of these.
73 */
74struct ppp_file {
75 enum {
76 INTERFACE=1, CHANNEL
77 } kind;
78 struct sk_buff_head xq; /* pppd transmit queue */
79 struct sk_buff_head rq; /* receive queue for pppd */
80 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */
81 atomic_t refcnt; /* # refs (incl /dev/ppp attached) */
82 int hdrlen; /* space to leave for headers */
83 int index; /* interface unit / channel number */
84 int dead; /* unit/channel has been shut down */
85};
86
b385a144 87#define PF_TO_X(pf, X) container_of(pf, X, file)
1da177e4
LT		 88
89#define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
90#define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
91
1da177e4
LT		 92/*
93 * Data structure describing one ppp unit.
94 * A ppp unit corresponds to a ppp network interface device
95 * and represents a multilink bundle.
96 * It can have 0 or more ppp channels connected to it.
97 */
98struct ppp {
99 struct ppp_file file; /* stuff for read/write/poll 0 */
100 struct file *owner; /* file that owns this unit 48 */
101 struct list_head channels; /* list of attached channels 4c */
102 int n_channels; /* how many channels are attached 54 */
103 spinlock_t rlock; /* lock for receive side 58 */
104 spinlock_t wlock; /* lock for transmit side 5c */
105 int mru; /* max receive unit 60 */
106 unsigned int flags; /* control bits 64 */
107 unsigned int xstate; /* transmit state bits 68 */
108 unsigned int rstate; /* receive state bits 6c */
109 int debug; /* debug flags 70 */
110 struct slcompress *vj; /* state for VJ header compression */
111 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
112 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
113 struct compressor *xcomp; /* transmit packet compressor 8c */
114 void *xc_state; /* its internal state 90 */
115 struct compressor *rcomp; /* receive decompressor 94 */
116 void *rc_state; /* its internal state 98 */
117 unsigned long last_xmit; /* jiffies when last pkt sent 9c */
118 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
119 struct net_device *dev; /* network interface device a4 */
739840d5 120 int closing; /* is device closing down? a8 */
1da177e4
LT		 121#ifdef CONFIG_PPP_MULTILINK
122 int nxchan; /* next channel to send something on */
123 u32 nxseq; /* next sequence number to send */
124 int mrru; /* MP: max reconst. receive unit */
125 u32 nextseq; /* MP: seq no of next packet */
126 u32 minseq; /* MP: min of most recent seqnos */
127 struct sk_buff_head mrq; /* MP: receive reconstruction queue */
128#endif /* CONFIG_PPP_MULTILINK */
1da177e4
LT		 129#ifdef CONFIG_PPP_FILTER
130 struct sock_filter *pass_filter; /* filter for packets to pass */
131 struct sock_filter *active_filter;/* filter for pkts to reset idle */
132 unsigned pass_len, active_len;
133#endif /* CONFIG_PPP_FILTER */
134};
135
136/*
137 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
b3f9b92a
MD		 138 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
139 * SC_MUST_COMP
1da177e4
LT		 140 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
141 * Bits in xstate: SC_COMP_RUN
142 */
143#define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
144 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
b3f9b92a 145 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
1da177e4
LT		 146
147/*
148 * Private data structure for each channel.
149 * This includes the data structure used for multilink.
150 */
151struct channel {
152 struct ppp_file file; /* stuff for read/write/poll */
153 struct list_head list; /* link in all/new_channels list */
154 struct ppp_channel *chan; /* public channel data structure */
155 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
156 spinlock_t downl; /* protects `chan', file.xq dequeue */
157 struct ppp *ppp; /* ppp unit we're connected to */
158 struct list_head clist; /* link in list of channels per unit */
159 rwlock_t upl; /* protects `ppp' */
160#ifdef CONFIG_PPP_MULTILINK
161 u8 avail; /* flag used in multilink stuff */
162 u8 had_frag; /* >= 1 fragments have been sent */
163 u32 lastseq; /* MP: last sequence # received */
164#endif /* CONFIG_PPP_MULTILINK */
165};
166
167/*
168 * SMP locking issues:
169 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
170 * list and the ppp.n_channels field, you need to take both locks
171 * before you modify them.
172 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
173 * channel.downl.
174 */
175
1da177e4 176/*
8ed965d6 177 * all_ppp_mutex protects the all_ppp_units mapping.
1da177e4
LT		 178 * It also ensures that finding a ppp unit in the all_ppp_units map
179 * and updating its file.refcnt field is atomic.
180 */
8ed965d6 181static DEFINE_MUTEX(all_ppp_mutex);
1da177e4 182static atomic_t ppp_unit_count = ATOMIC_INIT(0);
ab5024ab 183static DEFINE_IDR(ppp_units_idr);
1da177e4
LT		 184
185/*
186 * all_channels_lock protects all_channels and last_channel_index,
187 * and the atomicity of find a channel and updating its file.refcnt
188 * field.
189 */
190static DEFINE_SPINLOCK(all_channels_lock);
191static LIST_HEAD(all_channels);
192static LIST_HEAD(new_channels);
193static int last_channel_index;
194static atomic_t channel_count = ATOMIC_INIT(0);
195
196/* Get the PPP protocol number from a skb */
197#define PPP_PROTO(skb) (((skb)->data[0] << 8) + (skb)->data[1])
198
199/* We limit the length of ppp->file.rq to this (arbitrary) value */
200#define PPP_MAX_RQLEN 32
201
202/*
203 * Maximum number of multilink fragments queued up.
204 * This has to be large enough to cope with the maximum latency of
205 * the slowest channel relative to the others. Strictly it should
206 * depend on the number of channels and their characteristics.
207 */
208#define PPP_MP_MAX_QLEN 128
209
210/* Multilink header bits. */
211#define B 0x80 /* this fragment begins a packet */
212#define E 0x40 /* this fragment ends a packet */
213
214/* Compare multilink sequence numbers (assumed to be 32 bits wide) */
215#define seq_before(a, b) ((s32)((a) - (b)) < 0)
216#define seq_after(a, b) ((s32)((a) - (b)) > 0)
217
218/* Prototypes. */
219static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file,
220 unsigned int cmd, unsigned long arg);
221static void ppp_xmit_process(struct ppp *ppp);
222static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
223static void ppp_push(struct ppp *ppp);
224static void ppp_channel_push(struct channel *pch);
225static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
226 struct channel *pch);
227static void ppp_receive_error(struct ppp *ppp);
228static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
229static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
230 struct sk_buff *skb);
231#ifdef CONFIG_PPP_MULTILINK
232static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
233 struct channel *pch);
234static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
235static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
236static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
237#endif /* CONFIG_PPP_MULTILINK */
238static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
239static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
240static void ppp_ccp_closed(struct ppp *ppp);
241static struct compressor *find_compressor(int type);
242static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
243static struct ppp *ppp_create_interface(int unit, int *retp);
244static void init_ppp_file(struct ppp_file *pf, int kind);
245static void ppp_shutdown_interface(struct ppp *ppp);
246static void ppp_destroy_interface(struct ppp *ppp);
247static struct ppp *ppp_find_unit(int unit);
248static struct channel *ppp_find_channel(int unit);
249static int ppp_connect_channel(struct channel *pch, int unit);
250static int ppp_disconnect_channel(struct channel *pch);
251static void ppp_destroy_channel(struct channel *pch);
7a95d267
CG		 252static int unit_get(struct idr *p, void *ptr);
253static void unit_put(struct idr *p, int n);
254static void *unit_find(struct idr *p, int n);
1da177e4 255
56b22935 256static struct class *ppp_class;
1da177e4
LT		 257
258/* Translates a PPP protocol number to a NP index (NP == network protocol) */
259static inline int proto_to_npindex(int proto)
260{
261 switch (proto) {
262 case PPP_IP:
263 return NP_IP;
264 case PPP_IPV6:
265 return NP_IPV6;
266 case PPP_IPX:
267 return NP_IPX;
268 case PPP_AT:
269 return NP_AT;
270 case PPP_MPLS_UC:
271 return NP_MPLS_UC;
272 case PPP_MPLS_MC:
273 return NP_MPLS_MC;
274 }
275 return -EINVAL;
276}
277
278/* Translates an NP index into a PPP protocol number */
279static const int npindex_to_proto[NUM_NP] = {
280 PPP_IP,
281 PPP_IPV6,
282 PPP_IPX,
283 PPP_AT,
284 PPP_MPLS_UC,
285 PPP_MPLS_MC,
286};
6aa20a22 287
1da177e4
LT		 288/* Translates an ethertype into an NP index */
289static inline int ethertype_to_npindex(int ethertype)
290{
291 switch (ethertype) {
292 case ETH_P_IP:
293 return NP_IP;
294 case ETH_P_IPV6:
295 return NP_IPV6;
296 case ETH_P_IPX:
297 return NP_IPX;
298 case ETH_P_PPPTALK:
299 case ETH_P_ATALK:
300 return NP_AT;
301 case ETH_P_MPLS_UC:
302 return NP_MPLS_UC;
303 case ETH_P_MPLS_MC:
304 return NP_MPLS_MC;
305 }
306 return -1;
307}
308
309/* Translates an NP index into an ethertype */
310static const int npindex_to_ethertype[NUM_NP] = {
311 ETH_P_IP,
312 ETH_P_IPV6,
313 ETH_P_IPX,
314 ETH_P_PPPTALK,
315 ETH_P_MPLS_UC,
316 ETH_P_MPLS_MC,
317};
318
319/*
320 * Locking shorthand.
321 */
322#define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
323#define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
324#define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
325#define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
326#define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
327 ppp_recv_lock(ppp); } while (0)
328#define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
329 ppp_xmit_unlock(ppp); } while (0)
330
331/*
332 * /dev/ppp device routines.
333 * The /dev/ppp device is used by pppd to control the ppp unit.
334 * It supports the read, write, ioctl and poll functions.
335 * Open instances of /dev/ppp can be in one of three states:
336 * unattached, attached to a ppp unit, or attached to a ppp channel.
337 */
338static int ppp_open(struct inode *inode, struct file *file)
339{
f2b9857e 340 cycle_kernel_lock();
1da177e4
LT		 341 /*
342 * This could (should?) be enforced by the permissions on /dev/ppp.
343 */
344 if (!capable(CAP_NET_ADMIN))
345 return -EPERM;
346 return 0;
347}
348
f3ff8a4d 349static int ppp_release(struct inode *unused, struct file *file)
1da177e4
LT		 350{
351 struct ppp_file *pf = file->private_data;
352 struct ppp *ppp;
353
cd228d54 354 if (pf) {
1da177e4
LT		 355 file->private_data = NULL;
356 if (pf->kind == INTERFACE) {
357 ppp = PF_TO_PPP(pf);
358 if (file == ppp->owner)
359 ppp_shutdown_interface(ppp);
360 }
361 if (atomic_dec_and_test(&pf->refcnt)) {
362 switch (pf->kind) {
363 case INTERFACE:
364 ppp_destroy_interface(PF_TO_PPP(pf));
365 break;
366 case CHANNEL:
367 ppp_destroy_channel(PF_TO_CHANNEL(pf));
368 break;
369 }
370 }
371 }
372 return 0;
373}
374
375static ssize_t ppp_read(struct file *file, char __user *buf,
376 size_t count, loff_t *ppos)
377{
378 struct ppp_file *pf = file->private_data;
379 DECLARE_WAITQUEUE(wait, current);
380 ssize_t ret;
381 struct sk_buff *skb = NULL;
382
383 ret = count;
384
cd228d54 385 if (!pf)
1da177e4
LT		 386 return -ENXIO;
387 add_wait_queue(&pf->rwait, &wait);
388 for (;;) {
389 set_current_state(TASK_INTERRUPTIBLE);
390 skb = skb_dequeue(&pf->rq);
391 if (skb)
392 break;
393 ret = 0;
394 if (pf->dead)
395 break;
396 if (pf->kind == INTERFACE) {
397 /*
398 * Return 0 (EOF) on an interface that has no
399 * channels connected, unless it is looping
400 * network traffic (demand mode).
401 */
402 struct ppp *ppp = PF_TO_PPP(pf);
403 if (ppp->n_channels == 0
404 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
405 break;
406 }
407 ret = -EAGAIN;
408 if (file->f_flags & O_NONBLOCK)
409 break;
410 ret = -ERESTARTSYS;
411 if (signal_pending(current))
412 break;
413 schedule();
414 }
415 set_current_state(TASK_RUNNING);
416 remove_wait_queue(&pf->rwait, &wait);
417
cd228d54 418 if (!skb)
1da177e4
LT		 419 goto out;
420
421 ret = -EOVERFLOW;
422 if (skb->len > count)
423 goto outf;
424 ret = -EFAULT;
425 if (copy_to_user(buf, skb->data, skb->len))
426 goto outf;
427 ret = skb->len;
428
429 outf:
430 kfree_skb(skb);
431 out:
432 return ret;
433}
434
435static ssize_t ppp_write(struct file *file, const char __user *buf,
436 size_t count, loff_t *ppos)
437{
438 struct ppp_file *pf = file->private_data;
439 struct sk_buff *skb;
440 ssize_t ret;
441
cd228d54 442 if (!pf)
1da177e4
LT		 443 return -ENXIO;
444 ret = -ENOMEM;
445 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
cd228d54 446 if (!skb)
1da177e4
LT		 447 goto out;
448 skb_reserve(skb, pf->hdrlen);
449 ret = -EFAULT;
450 if (copy_from_user(skb_put(skb, count), buf, count)) {
451 kfree_skb(skb);
452 goto out;
453 }
454
455 skb_queue_tail(&pf->xq, skb);
456
457 switch (pf->kind) {
458 case INTERFACE:
459 ppp_xmit_process(PF_TO_PPP(pf));
460 break;
461 case CHANNEL:
462 ppp_channel_push(PF_TO_CHANNEL(pf));
463 break;
464 }
465
466 ret = count;
467
468 out:
469 return ret;
470}
471
472/* No kernel lock - fine */
473static unsigned int ppp_poll(struct file *file, poll_table *wait)
474{
475 struct ppp_file *pf = file->private_data;
476 unsigned int mask;
477
cd228d54 478 if (!pf)
1da177e4
LT		 479 return 0;
480 poll_wait(file, &pf->rwait, wait);
481 mask = POLLOUT | POLLWRNORM;
cd228d54 482 if (skb_peek(&pf->rq))
1da177e4
LT		 483 mask |= POLLIN | POLLRDNORM;
484 if (pf->dead)
485 mask |= POLLHUP;
486 else if (pf->kind == INTERFACE) {
487 /* see comment in ppp_read */
488 struct ppp *ppp = PF_TO_PPP(pf);
489 if (ppp->n_channels == 0
490 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
491 mask |= POLLIN | POLLRDNORM;
492 }
493
494 return mask;
495}
496
497#ifdef CONFIG_PPP_FILTER
498static int get_filter(void __user *arg, struct sock_filter **p)
499{
500 struct sock_fprog uprog;
501 struct sock_filter *code = NULL;
502 int len, err;
503
504 if (copy_from_user(&uprog, arg, sizeof(uprog)))
505 return -EFAULT;
506
1da177e4
LT		 507 if (!uprog.len) {
508 *p = NULL;
509 return 0;
510 }
511
512 len = uprog.len * sizeof(struct sock_filter);
513 code = kmalloc(len, GFP_KERNEL);
514 if (code == NULL)
515 return -ENOMEM;
516
517 if (copy_from_user(code, uprog.filter, len)) {
518 kfree(code);
519 return -EFAULT;
520 }
521
522 err = sk_chk_filter(code, uprog.len);
523 if (err) {
524 kfree(code);
525 return err;
526 }
527
528 *p = code;
529 return uprog.len;
530}
531#endif /* CONFIG_PPP_FILTER */
532
f3ff8a4d 533static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1da177e4
LT		 534{
535 struct ppp_file *pf = file->private_data;
536 struct ppp *ppp;
537 int err = -EFAULT, val, val2, i;
538 struct ppp_idle idle;
539 struct npioctl npi;
540 int unit, cflags;
541 struct slcompress *vj;
542 void __user *argp = (void __user *)arg;
543 int __user *p = argp;
544
cd228d54 545 if (!pf)
1da177e4
LT		 546 return ppp_unattached_ioctl(pf, file, cmd, arg);
547
548 if (cmd == PPPIOCDETACH) {
549 /*
550 * We have to be careful here... if the file descriptor
551 * has been dup'd, we could have another process in the
552 * middle of a poll using the same file *, so we had
553 * better not free the interface data structures -
554 * instead we fail the ioctl. Even in this case, we
555 * shut down the interface if we are the owner of it.
556 * Actually, we should get rid of PPPIOCDETACH, userland
557 * (i.e. pppd) could achieve the same effect by closing
558 * this fd and reopening /dev/ppp.
559 */
560 err = -EINVAL;
f3ff8a4d 561 lock_kernel();
1da177e4
LT		 562 if (pf->kind == INTERFACE) {
563 ppp = PF_TO_PPP(pf);
564 if (file == ppp->owner)
565 ppp_shutdown_interface(ppp);
566 }
516e0cc5 567 if (atomic_long_read(&file->f_count) <= 2) {
f3ff8a4d 568 ppp_release(NULL, file);
1da177e4
LT		 569 err = 0;
570 } else
516e0cc5
AV		 571 printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%ld\n",
572 atomic_long_read(&file->f_count));
f3ff8a4d 573 unlock_kernel();
1da177e4
LT		 574 return err;
575 }
576
577 if (pf->kind == CHANNEL) {
f3ff8a4d 578 struct channel *pch;
1da177e4
LT		 579 struct ppp_channel *chan;
580
f3ff8a4d
AC		 581 lock_kernel();
582 pch = PF_TO_CHANNEL(pf);
583
1da177e4
LT		 584 switch (cmd) {
585 case PPPIOCCONNECT:
586 if (get_user(unit, p))
587 break;
588 err = ppp_connect_channel(pch, unit);
589 break;
590
591 case PPPIOCDISCONN:
592 err = ppp_disconnect_channel(pch);
593 break;
594
595 default:
596 down_read(&pch->chan_sem);
597 chan = pch->chan;
598 err = -ENOTTY;
599 if (chan && chan->ops->ioctl)
600 err = chan->ops->ioctl(chan, cmd, arg);
601 up_read(&pch->chan_sem);
602 }
f3ff8a4d 603 unlock_kernel();
1da177e4
LT		 604 return err;
605 }
606
607 if (pf->kind != INTERFACE) {
608 /* can't happen */
609 printk(KERN_ERR "PPP: not interface or channel??\n");
610 return -EINVAL;
611 }
612
f3ff8a4d 613 lock_kernel();
1da177e4
LT		 614 ppp = PF_TO_PPP(pf);
615 switch (cmd) {
616 case PPPIOCSMRU:
617 if (get_user(val, p))
618 break;
619 ppp->mru = val;
620 err = 0;
621 break;
622
623 case PPPIOCSFLAGS:
624 if (get_user(val, p))
625 break;
626 ppp_lock(ppp);
627 cflags = ppp->flags & ~val;
628 ppp->flags = val & SC_FLAG_BITS;
629 ppp_unlock(ppp);
630 if (cflags & SC_CCP_OPEN)
631 ppp_ccp_closed(ppp);
632 err = 0;
633 break;
634
635 case PPPIOCGFLAGS:
636 val = ppp->flags | ppp->xstate | ppp->rstate;
637 if (put_user(val, p))
638 break;
639 err = 0;
640 break;
641
642 case PPPIOCSCOMPRESS:
643 err = ppp_set_compress(ppp, arg);
644 break;
645
646 case PPPIOCGUNIT:
647 if (put_user(ppp->file.index, p))
648 break;
649 err = 0;
650 break;
651
652 case PPPIOCSDEBUG:
653 if (get_user(val, p))
654 break;
655 ppp->debug = val;
656 err = 0;
657 break;
658
659 case PPPIOCGDEBUG:
660 if (put_user(ppp->debug, p))
661 break;
662 err = 0;
663 break;
664
665 case PPPIOCGIDLE:
666 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
667 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
668 if (copy_to_user(argp, &idle, sizeof(idle)))
669 break;
670 err = 0;
671 break;
672
673 case PPPIOCSMAXCID:
674 if (get_user(val, p))
675 break;
676 val2 = 15;
677 if ((val >> 16) != 0) {
678 val2 = val >> 16;
679 val &= 0xffff;
680 }
681 vj = slhc_init(val2+1, val+1);
cd228d54 682 if (!vj) {
1da177e4
LT		 683 printk(KERN_ERR "PPP: no memory (VJ compressor)\n");
684 err = -ENOMEM;
685 break;
686 }
687 ppp_lock(ppp);
cd228d54 688 if (ppp->vj)
1da177e4
LT		 689 slhc_free(ppp->vj);
690 ppp->vj = vj;
691 ppp_unlock(ppp);
692 err = 0;
693 break;
694
695 case PPPIOCGNPMODE:
696 case PPPIOCSNPMODE:
697 if (copy_from_user(&npi, argp, sizeof(npi)))
698 break;
699 err = proto_to_npindex(npi.protocol);
700 if (err < 0)
701 break;
702 i = err;
703 if (cmd == PPPIOCGNPMODE) {
704 err = -EFAULT;
705 npi.mode = ppp->npmode[i];
706 if (copy_to_user(argp, &npi, sizeof(npi)))
707 break;
708 } else {
709 ppp->npmode[i] = npi.mode;
710 /* we may be able to transmit more packets now (??) */
711 netif_wake_queue(ppp->dev);
712 }
713 err = 0;
714 break;
715
716#ifdef CONFIG_PPP_FILTER
717 case PPPIOCSPASS:
718 {
719 struct sock_filter *code;
720 err = get_filter(argp, &code);
721 if (err >= 0) {
722 ppp_lock(ppp);
723 kfree(ppp->pass_filter);
724 ppp->pass_filter = code;
725 ppp->pass_len = err;
726 ppp_unlock(ppp);
727 err = 0;
728 }
729 break;
730 }
731 case PPPIOCSACTIVE:
732 {
733 struct sock_filter *code;
734 err = get_filter(argp, &code);
735 if (err >= 0) {
736 ppp_lock(ppp);
737 kfree(ppp->active_filter);
738 ppp->active_filter = code;
739 ppp->active_len = err;
740 ppp_unlock(ppp);
741 err = 0;
742 }
743 break;
744 }
745#endif /* CONFIG_PPP_FILTER */
746
747#ifdef CONFIG_PPP_MULTILINK
748 case PPPIOCSMRRU:
749 if (get_user(val, p))
750 break;
751 ppp_recv_lock(ppp);
752 ppp->mrru = val;
753 ppp_recv_unlock(ppp);
754 err = 0;
755 break;
756#endif /* CONFIG_PPP_MULTILINK */
757
758 default:
759 err = -ENOTTY;
760 }
f3ff8a4d 761 unlock_kernel();
1da177e4
LT		 762 return err;
763}
764
765static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file,
766 unsigned int cmd, unsigned long arg)
767{
768 int unit, err = -EFAULT;
769 struct ppp *ppp;
770 struct channel *chan;
771 int __user *p = (int __user *)arg;
772
f3ff8a4d 773 lock_kernel();
1da177e4
LT		 774 switch (cmd) {
775 case PPPIOCNEWUNIT:
776 /* Create a new ppp unit */
777 if (get_user(unit, p))
778 break;
779 ppp = ppp_create_interface(unit, &err);
cd228d54 780 if (!ppp)
1da177e4
LT		 781 break;
782 file->private_data = &ppp->file;
783 ppp->owner = file;
784 err = -EFAULT;
785 if (put_user(ppp->file.index, p))
786 break;
787 err = 0;
788 break;
789
790 case PPPIOCATTACH:
791 /* Attach to an existing ppp unit */
792 if (get_user(unit, p))
793 break;
8ed965d6 794 mutex_lock(&all_ppp_mutex);
1da177e4
LT		 795 err = -ENXIO;
796 ppp = ppp_find_unit(unit);
cd228d54 797 if (ppp) {
1da177e4
LT		 798 atomic_inc(&ppp->file.refcnt);
799 file->private_data = &ppp->file;
800 err = 0;
801 }
8ed965d6 802 mutex_unlock(&all_ppp_mutex);
1da177e4
LT		 803 break;
804
805 case PPPIOCATTCHAN:
806 if (get_user(unit, p))
807 break;
808 spin_lock_bh(&all_channels_lock);
809 err = -ENXIO;
810 chan = ppp_find_channel(unit);
cd228d54 811 if (chan) {
1da177e4
LT		 812 atomic_inc(&chan->file.refcnt);
813 file->private_data = &chan->file;
814 err = 0;
815 }
816 spin_unlock_bh(&all_channels_lock);
817 break;
818
819 default:
820 err = -ENOTTY;
821 }
f3ff8a4d 822 unlock_kernel();
1da177e4
LT		 823 return err;
824}
825
d54b1fdb 826static const struct file_operations ppp_device_fops = {
1da177e4
LT		 827 .owner = THIS_MODULE,
828 .read = ppp_read,
829 .write = ppp_write,
830 .poll = ppp_poll,
f3ff8a4d 831 .unlocked_ioctl = ppp_ioctl,
1da177e4
LT		 832 .open = ppp_open,
833 .release = ppp_release
834};
835
836#define PPP_MAJOR 108
837
838/* Called at boot time if ppp is compiled into the kernel,
839 or at module load time (from init_module) if compiled as a module. */
840static int __init ppp_init(void)
841{
842 int err;
843
844 printk(KERN_INFO "PPP generic driver version " PPP_VERSION "\n");
845 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
846 if (!err) {
56b22935 847 ppp_class = class_create(THIS_MODULE, "ppp");
1da177e4
LT		 848 if (IS_ERR(ppp_class)) {
849 err = PTR_ERR(ppp_class);
850 goto out_chrdev;
851 }
6e05d6c4
GKH		 852 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL,
853 "ppp");
1da177e4
LT		 854 }
855
856out:
857 if (err)
858 printk(KERN_ERR "failed to register PPP device (%d)\n", err);
859 return err;
860
1da177e4
LT		 861out_chrdev:
862 unregister_chrdev(PPP_MAJOR, "ppp");
863 goto out;
864}
865
866/*
867 * Network interface unit routines.
868 */
869static int
870ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
871{
c8019bf3 872 struct ppp *ppp = netdev_priv(dev);
1da177e4
LT		 873 int npi, proto;
874 unsigned char *pp;
875
876 npi = ethertype_to_npindex(ntohs(skb->protocol));
877 if (npi < 0)
878 goto outf;
879
880 /* Drop, accept or reject the packet */
881 switch (ppp->npmode[npi]) {
882 case NPMODE_PASS:
883 break;
884 case NPMODE_QUEUE:
885 /* it would be nice to have a way to tell the network
886 system to queue this one up for later. */
887 goto outf;
888 case NPMODE_DROP:
889 case NPMODE_ERROR:
890 goto outf;
891 }
892
893 /* Put the 2-byte PPP protocol number on the front,
894 making sure there is room for the address and control fields. */
7b797d5b
HX		 895 if (skb_cow_head(skb, PPP_HDRLEN))
896 goto outf;
897
1da177e4
LT		 898 pp = skb_push(skb, 2);
899 proto = npindex_to_proto[npi];
900 pp[0] = proto >> 8;
901 pp[1] = proto;
902
903 netif_stop_queue(dev);
904 skb_queue_tail(&ppp->file.xq, skb);
905 ppp_xmit_process(ppp);
906 return 0;
907
908 outf:
909 kfree_skb(skb);
8c0469cd 910 ++ppp->dev->stats.tx_dropped;
1da177e4
LT		 911 return 0;
912}
913
1da177e4
LT		 914static int
915ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
916{
c8019bf3 917 struct ppp *ppp = netdev_priv(dev);
1da177e4
LT		 918 int err = -EFAULT;
919 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
920 struct ppp_stats stats;
921 struct ppp_comp_stats cstats;
922 char *vers;
923
924 switch (cmd) {
925 case SIOCGPPPSTATS:
926 ppp_get_stats(ppp, &stats);
927 if (copy_to_user(addr, &stats, sizeof(stats)))
928 break;
929 err = 0;
930 break;
931
932 case SIOCGPPPCSTATS:
933 memset(&cstats, 0, sizeof(cstats));
cd228d54 934 if (ppp->xc_state)
1da177e4 935 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
cd228d54 936 if (ppp->rc_state)
1da177e4
LT		 937 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
938 if (copy_to_user(addr, &cstats, sizeof(cstats)))
939 break;
940 err = 0;
941 break;
942
943 case SIOCGPPPVER:
944 vers = PPP_VERSION;
945 if (copy_to_user(addr, vers, strlen(vers) + 1))
946 break;
947 err = 0;
948 break;
949
950 default:
951 err = -EINVAL;
952 }
953
954 return err;
955}
956
52256cfc 957static const struct net_device_ops ppp_netdev_ops = {
00829823
SH		 958 .ndo_start_xmit = ppp_start_xmit,
959 .ndo_do_ioctl = ppp_net_ioctl,
52256cfc
SH		 960};
961
1da177e4
LT		 962static void ppp_setup(struct net_device *dev)
963{
52256cfc 964 dev->netdev_ops = &ppp_netdev_ops;
1da177e4
LT		 965 dev->hard_header_len = PPP_HDRLEN;
966 dev->mtu = PPP_MTU;
967 dev->addr_len = 0;
968 dev->tx_queue_len = 3;
969 dev->type = ARPHRD_PPP;
970 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
971}
972
973/*
974 * Transmit-side routines.
975 */
976
977/*
978 * Called to do any work queued up on the transmit side
979 * that can now be done.
980 */
981static void
982ppp_xmit_process(struct ppp *ppp)
983{
984 struct sk_buff *skb;
985
986 ppp_xmit_lock(ppp);
739840d5 987 if (!ppp->closing) {
1da177e4 988 ppp_push(ppp);
cd228d54
JP		 989 while (!ppp->xmit_pending
990 && (skb = skb_dequeue(&ppp->file.xq)))
1da177e4
LT		 991 ppp_send_frame(ppp, skb);
992 /* If there's no work left to do, tell the core net
993 code that we can accept some more. */
cd228d54 994 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1da177e4
LT		 995 netif_wake_queue(ppp->dev);
996 }
997 ppp_xmit_unlock(ppp);
998}
999
b3f9b92a
MD		 1000static inline struct sk_buff *
1001pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1002{
1003 struct sk_buff *new_skb;
1004 int len;
1005 int new_skb_size = ppp->dev->mtu +
1006 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1007 int compressor_skb_size = ppp->dev->mtu +
1008 ppp->xcomp->comp_extra + PPP_HDRLEN;
1009 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1010 if (!new_skb) {
1011 if (net_ratelimit())
1012 printk(KERN_ERR "PPP: no memory (comp pkt)\n");
1013 return NULL;
1014 }
1015 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1016 skb_reserve(new_skb,
1017 ppp->dev->hard_header_len - PPP_HDRLEN);
1018
1019 /* compressor still expects A/C bytes in hdr */
1020 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1021 new_skb->data, skb->len + 2,
1022 compressor_skb_size);
1023 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1024 kfree_skb(skb);
1025 skb = new_skb;
1026 skb_put(skb, len);
1027 skb_pull(skb, 2); /* pull off A/C bytes */
1028 } else if (len == 0) {
1029 /* didn't compress, or CCP not up yet */
1030 kfree_skb(new_skb);
1031 new_skb = skb;
1032 } else {
1033 /*
1034 * (len < 0)
1035 * MPPE requires that we do not send unencrypted
1036 * frames. The compressor will return -1 if we
1037 * should drop the frame. We cannot simply test
1038 * the compress_proto because MPPE and MPPC share
1039 * the same number.
1040 */
1041 if (net_ratelimit())
1042 printk(KERN_ERR "ppp: compressor dropped pkt\n");
1043 kfree_skb(skb);
1044 kfree_skb(new_skb);
1045 new_skb = NULL;
1046 }
1047 return new_skb;
1048}
1049
1da177e4
LT		 1050/*
1051 * Compress and send a frame.
1052 * The caller should have locked the xmit path,
1053 * and xmit_pending should be 0.
1054 */
1055static void
1056ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1057{
1058 int proto = PPP_PROTO(skb);
1059 struct sk_buff *new_skb;
1060 int len;
1061 unsigned char *cp;
1062
1063 if (proto < 0x8000) {
1064#ifdef CONFIG_PPP_FILTER
1065 /* check if we should pass this packet */
1066 /* the filter instructions are constructed assuming
1067 a four-byte PPP header on each packet */
1068 *skb_push(skb, 2) = 1;
1069 if (ppp->pass_filter
1070 && sk_run_filter(skb, ppp->pass_filter,
1071 ppp->pass_len) == 0) {
1072 if (ppp->debug & 1)
1073 printk(KERN_DEBUG "PPP: outbound frame not passed\n");
1074 kfree_skb(skb);
1075 return;
1076 }
1077 /* if this packet passes the active filter, record the time */
1078 if (!(ppp->active_filter
1079 && sk_run_filter(skb, ppp->active_filter,
1080 ppp->active_len) == 0))
1081 ppp->last_xmit = jiffies;
1082 skb_pull(skb, 2);
1083#else
1084 /* for data packets, record the time */
1085 ppp->last_xmit = jiffies;
1086#endif /* CONFIG_PPP_FILTER */
1087 }
1088
8c0469cd
PZ		 1089 ++ppp->dev->stats.tx_packets;
1090 ppp->dev->stats.tx_bytes += skb->len - 2;
1da177e4
LT		 1091
1092 switch (proto) {
1093 case PPP_IP:
cd228d54 1094 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1da177e4
LT		 1095 break;
1096 /* try to do VJ TCP header compression */
1097 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1098 GFP_ATOMIC);
cd228d54 1099 if (!new_skb) {
1da177e4
LT		 1100 printk(KERN_ERR "PPP: no memory (VJ comp pkt)\n");
1101 goto drop;
1102 }
1103 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1104 cp = skb->data + 2;
1105 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1106 new_skb->data + 2, &cp,
1107 !(ppp->flags & SC_NO_TCP_CCID));
1108 if (cp == skb->data + 2) {
1109 /* didn't compress */
1110 kfree_skb(new_skb);
1111 } else {
1112 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1113 proto = PPP_VJC_COMP;
1114 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1115 } else {
1116 proto = PPP_VJC_UNCOMP;
1117 cp[0] = skb->data[2];
1118 }
1119 kfree_skb(skb);
1120 skb = new_skb;
1121 cp = skb_put(skb, len + 2);
1122 cp[0] = 0;
1123 cp[1] = proto;
1124 }
1125 break;
1126
1127 case PPP_CCP:
1128 /* peek at outbound CCP frames */
1129 ppp_ccp_peek(ppp, skb, 0);
1130 break;
1131 }
1132
1133 /* try to do packet compression */
cd228d54 1134 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state
1da177e4 1135 && proto != PPP_LCP && proto != PPP_CCP) {
b3f9b92a
MD		 1136 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1137 if (net_ratelimit())
1138 printk(KERN_ERR "ppp: compression required but down - pkt dropped.\n");
1da177e4
LT		 1139 goto drop;
1140 }
b3f9b92a
MD		 1141 skb = pad_compress_skb(ppp, skb);
1142 if (!skb)
1143 goto drop;
1da177e4
LT		 1144 }
1145
1146 /*
1147 * If we are waiting for traffic (demand dialling),
1148 * queue it up for pppd to receive.
1149 */
1150 if (ppp->flags & SC_LOOP_TRAFFIC) {
1151 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1152 goto drop;
1153 skb_queue_tail(&ppp->file.rq, skb);
1154 wake_up_interruptible(&ppp->file.rwait);
1155 return;
1156 }
1157
1158 ppp->xmit_pending = skb;
1159 ppp_push(ppp);
1160 return;
1161
1162 drop:
b3f9b92a
MD		 1163 if (skb)
1164 kfree_skb(skb);
8c0469cd 1165 ++ppp->dev->stats.tx_errors;
1da177e4
LT		 1166}
1167
1168/*
1169 * Try to send the frame in xmit_pending.
1170 * The caller should have the xmit path locked.
1171 */
1172static void
1173ppp_push(struct ppp *ppp)
1174{
1175 struct list_head *list;
1176 struct channel *pch;
1177 struct sk_buff *skb = ppp->xmit_pending;
1178
cd228d54 1179 if (!skb)
1da177e4
LT		 1180 return;
1181
1182 list = &ppp->channels;
1183 if (list_empty(list)) {
1184 /* nowhere to send the packet, just drop it */
1185 ppp->xmit_pending = NULL;
1186 kfree_skb(skb);
1187 return;
1188 }
1189
1190 if ((ppp->flags & SC_MULTILINK) == 0) {
1191 /* not doing multilink: send it down the first channel */
1192 list = list->next;
1193 pch = list_entry(list, struct channel, clist);
1194
1195 spin_lock_bh(&pch->downl);
1196 if (pch->chan) {
1197 if (pch->chan->ops->start_xmit(pch->chan, skb))
1198 ppp->xmit_pending = NULL;
1199 } else {
1200 /* channel got unregistered */
1201 kfree_skb(skb);
1202 ppp->xmit_pending = NULL;
1203 }
1204 spin_unlock_bh(&pch->downl);
1205 return;
1206 }
1207
1208#ifdef CONFIG_PPP_MULTILINK
1209 /* Multilink: fragment the packet over as many links
1210 as can take the packet at the moment. */
1211 if (!ppp_mp_explode(ppp, skb))
1212 return;
1213#endif /* CONFIG_PPP_MULTILINK */
1214
1215 ppp->xmit_pending = NULL;
1216 kfree_skb(skb);
1217}
1218
1219#ifdef CONFIG_PPP_MULTILINK
1220/*
1221 * Divide a packet to be transmitted into fragments and
1222 * send them out the individual links.
1223 */
1224static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1225{
516cd15f 1226 int len, fragsize;
1da177e4 1227 int i, bits, hdrlen, mtu;
516cd15f
PM		 1228 int flen;
1229 int navail, nfree;
1230 int nbigger;
1da177e4
LT		 1231 unsigned char *p, *q;
1232 struct list_head *list;
1233 struct channel *pch;
1234 struct sk_buff *frag;
1235 struct ppp_channel *chan;
1236
516cd15f
PM		 1237 nfree = 0; /* # channels which have no packet already queued */
1238 navail = 0; /* total # of usable channels (not deregistered) */
1da177e4 1239 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
516cd15f 1240 i = 0;
81616c5a 1241 list_for_each_entry(pch, &ppp->channels, clist) {
516cd15f
PM		 1242 navail += pch->avail = (pch->chan != NULL);
1243 if (pch->avail) {
b03efcfb
DM		 1244 if (skb_queue_empty(&pch->file.xq) ||
1245 !pch->had_frag) {
516cd15f
PM		 1246 pch->avail = 2;
1247 ++nfree;
1da177e4 1248 }
516cd15f
PM		 1249 if (!pch->had_frag && i < ppp->nxchan)
1250 ppp->nxchan = i;
1da177e4 1251 }
516cd15f 1252 ++i;
1da177e4 1253 }
516cd15f
PM		 1254
1255 /*
1256 * Don't start sending this packet unless at least half of
1257 * the channels are free. This gives much better TCP
1258 * performance if we have a lot of channels.
1259 */
1260 if (nfree == 0 || nfree < navail / 2)
1da177e4
LT		 1261 return 0; /* can't take now, leave it in xmit_pending */
1262
1263 /* Do protocol field compression (XXX this should be optional) */
1264 p = skb->data;
1265 len = skb->len;
1266 if (*p == 0) {
1267 ++p;
1268 --len;
1269 }
1270
516cd15f
PM		 1271 /*
1272 * Decide on fragment size.
1273 * We create a fragment for each free channel regardless of
1274 * how small they are (i.e. even 0 length) in order to minimize
1275 * the time that it will take to detect when a channel drops
1276 * a fragment.
1277 */
1da177e4 1278 fragsize = len;
516cd15f 1279 if (nfree > 1)
57cd5f75 1280 fragsize = DIV_ROUND_UP(fragsize, nfree);
516cd15f
PM		 1281 /* nbigger channels get fragsize bytes, the rest get fragsize-1,
1282 except if nbigger==0, then they all get fragsize. */
1283 nbigger = len % nfree;
1da177e4
LT		 1284
1285 /* skip to the channel after the one we last used
1286 and start at that one */
81616c5a 1287 list = &ppp->channels;
1da177e4
LT		 1288 for (i = 0; i < ppp->nxchan; ++i) {
1289 list = list->next;
1290 if (list == &ppp->channels) {
1291 i = 0;
1292 break;
1293 }
1294 }
1295
1296 /* create a fragment for each channel */
1297 bits = B;
516cd15f 1298 while (nfree > 0 || len > 0) {
1da177e4
LT		 1299 list = list->next;
1300 if (list == &ppp->channels) {
1301 i = 0;
1302 continue;
1303 }
1304 pch = list_entry(list, struct channel, clist);
1305 ++i;
1306 if (!pch->avail)
1307 continue;
1308
516cd15f
PM		 1309 /*
1310 * Skip this channel if it has a fragment pending already and
1311 * we haven't given a fragment to all of the free channels.
1312 */
1313 if (pch->avail == 1) {
1314 if (nfree > 0)
1315 continue;
1316 } else {
1317 --nfree;
1318 pch->avail = 1;
1319 }
1320
1da177e4
LT		 1321 /* check the channel's mtu and whether it is still attached. */
1322 spin_lock_bh(&pch->downl);
516cd15f
PM		 1323 if (pch->chan == NULL) {
1324 /* can't use this channel, it's being deregistered */
1da177e4
LT		 1325 spin_unlock_bh(&pch->downl);
1326 pch->avail = 0;
516cd15f 1327 if (--navail == 0)
1da177e4
LT		 1328 break;
1329 continue;
1330 }
1331
1332 /*
516cd15f
PM		 1333 * Create a fragment for this channel of
1334 * min(max(mtu+2-hdrlen, 4), fragsize, len) bytes.
1335 * If mtu+2-hdrlen < 4, that is a ridiculously small
1336 * MTU, so we use mtu = 2 + hdrlen.
1da177e4
LT		 1337 */
1338 if (fragsize > len)
1339 fragsize = len;
516cd15f
PM		 1340 flen = fragsize;
1341 mtu = pch->chan->mtu + 2 - hdrlen;
1342 if (mtu < 4)
1343 mtu = 4;
1344 if (flen > mtu)
1345 flen = mtu;
1346 if (flen == len && nfree == 0)
1347 bits |= E;
1348 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
cd228d54 1349 if (!frag)
516cd15f
PM		 1350 goto noskb;
1351 q = skb_put(frag, flen + hdrlen);
1352
1353 /* make the MP header */
1354 q[0] = PPP_MP >> 8;
1355 q[1] = PPP_MP;
1356 if (ppp->flags & SC_MP_XSHORTSEQ) {
1357 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1358 q[3] = ppp->nxseq;
1359 } else {
1360 q[2] = bits;
1361 q[3] = ppp->nxseq >> 16;
1362 q[4] = ppp->nxseq >> 8;
1363 q[5] = ppp->nxseq;
1da177e4 1364 }
516cd15f
PM		 1365
1366 /*
1367 * Copy the data in.
1368 * Unfortunately there is a bug in older versions of
1369 * the Linux PPP multilink reconstruction code where it
1370 * drops 0-length fragments. Therefore we make sure the
1371 * fragment has at least one byte of data. Any bytes
1372 * we add in this situation will end up as padding on the
1373 * end of the reconstructed packet.
1374 */
1375 if (flen == 0)
1376 *skb_put(frag, 1) = 0;
1377 else
1378 memcpy(q + hdrlen, p, flen);
1379
1380 /* try to send it down the channel */
1381 chan = pch->chan;
b03efcfb
DM		 1382 if (!skb_queue_empty(&pch->file.xq) ||
1383 !chan->ops->start_xmit(chan, frag))
516cd15f
PM		 1384 skb_queue_tail(&pch->file.xq, frag);
1385 pch->had_frag = 1;
1386 p += flen;
1387 len -= flen;
1388 ++ppp->nxseq;
1389 bits = 0;
1da177e4 1390 spin_unlock_bh(&pch->downl);
516cd15f
PM		 1391
1392 if (--nbigger == 0 && fragsize > 0)
1393 --fragsize;
1394 }
1da177e4
LT		 1395 ppp->nxchan = i;
1396
1397 return 1;
1398
1399 noskb:
1400 spin_unlock_bh(&pch->downl);
1401 if (ppp->debug & 1)
1402 printk(KERN_ERR "PPP: no memory (fragment)\n");
8c0469cd 1403 ++ppp->dev->stats.tx_errors;
1da177e4
LT		 1404 ++ppp->nxseq;
1405 return 1; /* abandon the frame */
1406}
1407#endif /* CONFIG_PPP_MULTILINK */
1408
1409/*
1410 * Try to send data out on a channel.
1411 */
1412static void
1413ppp_channel_push(struct channel *pch)
1414{
1415 struct sk_buff *skb;
1416 struct ppp *ppp;
1417
1418 spin_lock_bh(&pch->downl);
cd228d54 1419 if (pch->chan) {
b03efcfb 1420 while (!skb_queue_empty(&pch->file.xq)) {
1da177e4
LT		 1421 skb = skb_dequeue(&pch->file.xq);
1422 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1423 /* put the packet back and try again later */
1424 skb_queue_head(&pch->file.xq, skb);
1425 break;
1426 }
1427 }
1428 } else {
1429 /* channel got deregistered */
1430 skb_queue_purge(&pch->file.xq);
1431 }
1432 spin_unlock_bh(&pch->downl);
1433 /* see if there is anything from the attached unit to be sent */
b03efcfb 1434 if (skb_queue_empty(&pch->file.xq)) {
1da177e4
LT		 1435 read_lock_bh(&pch->upl);
1436 ppp = pch->ppp;
cd228d54 1437 if (ppp)
1da177e4
LT		 1438 ppp_xmit_process(ppp);
1439 read_unlock_bh(&pch->upl);
1440 }
1441}
1442
1443/*
1444 * Receive-side routines.
1445 */
1446
1447/* misuse a few fields of the skb for MP reconstruction */
1448#define sequence priority
1449#define BEbits cb[0]
1450
1451static inline void
1452ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1453{
1454 ppp_recv_lock(ppp);
739840d5 1455 if (!ppp->closing)
1da177e4
LT		 1456 ppp_receive_frame(ppp, skb, pch);
1457 else
1458 kfree_skb(skb);
1459 ppp_recv_unlock(ppp);
1460}
1461
1462void
1463ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1464{
1465 struct channel *pch = chan->ppp;
1466 int proto;
1467
cd228d54 1468 if (!pch || skb->len == 0) {
1da177e4
LT		 1469 kfree_skb(skb);
1470 return;
1471 }
516cd15f 1472
1da177e4
LT		 1473 proto = PPP_PROTO(skb);
1474 read_lock_bh(&pch->upl);
cd228d54 1475 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1da177e4
LT		 1476 /* put it on the channel queue */
1477 skb_queue_tail(&pch->file.rq, skb);
1478 /* drop old frames if queue too long */
1479 while (pch->file.rq.qlen > PPP_MAX_RQLEN
cd228d54 1480 && (skb = skb_dequeue(&pch->file.rq)))
1da177e4
LT		 1481 kfree_skb(skb);
1482 wake_up_interruptible(&pch->file.rwait);
1483 } else {
1484 ppp_do_recv(pch->ppp, skb, pch);
1485 }
1486 read_unlock_bh(&pch->upl);
1487}
1488
1489/* Put a 0-length skb in the receive queue as an error indication */
1490void
1491ppp_input_error(struct ppp_channel *chan, int code)
1492{
1493 struct channel *pch = chan->ppp;
1494 struct sk_buff *skb;
1495
cd228d54 1496 if (!pch)
1da177e4
LT		 1497 return;
1498
1499 read_lock_bh(&pch->upl);
cd228d54 1500 if (pch->ppp) {
1da177e4 1501 skb = alloc_skb(0, GFP_ATOMIC);
cd228d54 1502 if (skb) {
1da177e4
LT		 1503 skb->len = 0; /* probably unnecessary */
1504 skb->cb[0] = code;
1505 ppp_do_recv(pch->ppp, skb, pch);
1506 }
1507 }
1508 read_unlock_bh(&pch->upl);
1509}
1510
1511/*
1512 * We come in here to process a received frame.
1513 * The receive side of the ppp unit is locked.
1514 */
1515static void
1516ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1517{
2a38b775 1518 if (pskb_may_pull(skb, 2)) {
1da177e4
LT		 1519#ifdef CONFIG_PPP_MULTILINK
1520 /* XXX do channel-level decompression here */
1521 if (PPP_PROTO(skb) == PPP_MP)
1522 ppp_receive_mp_frame(ppp, skb, pch);
1523 else
1524#endif /* CONFIG_PPP_MULTILINK */
1525 ppp_receive_nonmp_frame(ppp, skb);
1526 return;
1527 }
1528
1529 if (skb->len > 0)
1530 /* note: a 0-length skb is used as an error indication */
8c0469cd 1531 ++ppp->dev->stats.rx_length_errors;
1da177e4
LT		 1532
1533 kfree_skb(skb);
1534 ppp_receive_error(ppp);
1535}
1536
1537static void
1538ppp_receive_error(struct ppp *ppp)
1539{
8c0469cd 1540 ++ppp->dev->stats.rx_errors;
cd228d54 1541 if (ppp->vj)
1da177e4
LT		 1542 slhc_toss(ppp->vj);
1543}
1544
1545static void
1546ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1547{
1548 struct sk_buff *ns;
1549 int proto, len, npi;
1550
1551 /*
1552 * Decompress the frame, if compressed.
1553 * Note that some decompressors need to see uncompressed frames
1554 * that come in as well as compressed frames.
1555 */
cd228d54 1556 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)
1da177e4
LT		 1557 && (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1558 skb = ppp_decompress_frame(ppp, skb);
1559
b3f9b92a
MD		 1560 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1561 goto err;
1562
1da177e4
LT		 1563 proto = PPP_PROTO(skb);
1564 switch (proto) {
1565 case PPP_VJC_COMP:
1566 /* decompress VJ compressed packets */
cd228d54 1567 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1da177e4
LT		 1568 goto err;
1569
2a38b775 1570 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1da177e4
LT		 1571 /* copy to a new sk_buff with more tailroom */
1572 ns = dev_alloc_skb(skb->len + 128);
cd228d54 1573 if (!ns) {
1da177e4
LT		 1574 printk(KERN_ERR"PPP: no memory (VJ decomp)\n");
1575 goto err;
1576 }
1577 skb_reserve(ns, 2);
1578 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1579 kfree_skb(skb);
1580 skb = ns;
1581 }
e3f749c4
HX		 1582 else
1583 skb->ip_summed = CHECKSUM_NONE;
1da177e4
LT		 1584
1585 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1586 if (len <= 0) {
1587 printk(KERN_DEBUG "PPP: VJ decompression error\n");
1588 goto err;
1589 }
1590 len += 2;
1591 if (len > skb->len)
1592 skb_put(skb, len - skb->len);
1593 else if (len < skb->len)
1594 skb_trim(skb, len);
1595 proto = PPP_IP;
1596 break;
1597
1598 case PPP_VJC_UNCOMP:
cd228d54 1599 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1da177e4 1600 goto err;
6aa20a22 1601
1da177e4
LT		 1602 /* Until we fix the decompressor need to make sure
1603 * data portion is linear.
1604 */
6aa20a22 1605 if (!pskb_may_pull(skb, skb->len))
1da177e4
LT		 1606 goto err;
1607
1608 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1609 printk(KERN_ERR "PPP: VJ uncompressed error\n");
1610 goto err;
1611 }
1612 proto = PPP_IP;
1613 break;
1614
1615 case PPP_CCP:
1616 ppp_ccp_peek(ppp, skb, 1);
1617 break;
1618 }
1619
8c0469cd
PZ		 1620 ++ppp->dev->stats.rx_packets;
1621 ppp->dev->stats.rx_bytes += skb->len - 2;
1da177e4
LT		 1622
1623 npi = proto_to_npindex(proto);
1624 if (npi < 0) {
1625 /* control or unknown frame - pass it to pppd */
1626 skb_queue_tail(&ppp->file.rq, skb);
1627 /* limit queue length by dropping old frames */
1628 while (ppp->file.rq.qlen > PPP_MAX_RQLEN
cd228d54 1629 && (skb = skb_dequeue(&ppp->file.rq)))
1da177e4
LT		 1630 kfree_skb(skb);
1631 /* wake up any process polling or blocking on read */
1632 wake_up_interruptible(&ppp->file.rwait);
1633
1634 } else {
1635 /* network protocol frame - give it to the kernel */
1636
1637#ifdef CONFIG_PPP_FILTER
1638 /* check if the packet passes the pass and active filters */
1639 /* the filter instructions are constructed assuming
1640 a four-byte PPP header on each packet */
2a38b775
HX		 1641 if (ppp->pass_filter || ppp->active_filter) {
1642 if (skb_cloned(skb) &&
1643 pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
1644 goto err;
1645
1646 *skb_push(skb, 2) = 0;
1647 if (ppp->pass_filter
1648 && sk_run_filter(skb, ppp->pass_filter,
1649 ppp->pass_len) == 0) {
1650 if (ppp->debug & 1)
1651 printk(KERN_DEBUG "PPP: inbound frame "
1652 "not passed\n");
1653 kfree_skb(skb);
1654 return;
1655 }
1656 if (!(ppp->active_filter
1657 && sk_run_filter(skb, ppp->active_filter,
1658 ppp->active_len) == 0))
1659 ppp->last_recv = jiffies;
1660 __skb_pull(skb, 2);
1661 } else
1da177e4 1662#endif /* CONFIG_PPP_FILTER */
2a38b775 1663 ppp->last_recv = jiffies;
1da177e4
LT		 1664
1665 if ((ppp->dev->flags & IFF_UP) == 0
1666 || ppp->npmode[npi] != NPMODE_PASS) {
1667 kfree_skb(skb);
1668 } else {
cbb042f9
HX		 1669 /* chop off protocol */
1670 skb_pull_rcsum(skb, 2);
1da177e4
LT		 1671 skb->dev = ppp->dev;
1672 skb->protocol = htons(npindex_to_ethertype[npi]);
459a98ed 1673 skb_reset_mac_header(skb);
1da177e4 1674 netif_rx(skb);
1da177e4
LT		 1675 }
1676 }
1677 return;
1678
1679 err:
1680 kfree_skb(skb);
1681 ppp_receive_error(ppp);
1682}
1683
1684static struct sk_buff *
1685ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1686{
1687 int proto = PPP_PROTO(skb);
1688 struct sk_buff *ns;
1689 int len;
1690
1691 /* Until we fix all the decompressor's need to make sure
1692 * data portion is linear.
1693 */
1694 if (!pskb_may_pull(skb, skb->len))
1695 goto err;
1696
1697 if (proto == PPP_COMP) {
4b2a8fb3
KS		 1698 int obuff_size;
1699
1700 switch(ppp->rcomp->compress_proto) {
1701 case CI_MPPE:
1702 obuff_size = ppp->mru + PPP_HDRLEN + 1;
1703 break;
1704 default:
1705 obuff_size = ppp->mru + PPP_HDRLEN;
1706 break;
1707 }
1708
1709 ns = dev_alloc_skb(obuff_size);
cd228d54 1710 if (!ns) {
1da177e4
LT		 1711 printk(KERN_ERR "ppp_decompress_frame: no memory\n");
1712 goto err;
1713 }
1714 /* the decompressor still expects the A/C bytes in the hdr */
1715 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
06c7af56 1716 skb->len + 2, ns->data, obuff_size);
1da177e4
LT		 1717 if (len < 0) {
1718 /* Pass the compressed frame to pppd as an
1719 error indication. */
1720 if (len == DECOMP_FATALERROR)
1721 ppp->rstate |= SC_DC_FERROR;
1722 kfree_skb(ns);
1723 goto err;
1724 }
1725
1726 kfree_skb(skb);
1727 skb = ns;
1728 skb_put(skb, len);
1729 skb_pull(skb, 2); /* pull off the A/C bytes */
1730
1731 } else {
1732 /* Uncompressed frame - pass to decompressor so it
1733 can update its dictionary if necessary. */
1734 if (ppp->rcomp->incomp)
1735 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1736 skb->len + 2);
1737 }
1738
1739 return skb;
1740
1741 err:
1742 ppp->rstate |= SC_DC_ERROR;
1743 ppp_receive_error(ppp);
1744 return skb;
1745}
1746
1747#ifdef CONFIG_PPP_MULTILINK
1748/*
1749 * Receive a multilink frame.
1750 * We put it on the reconstruction queue and then pull off
1751 * as many completed frames as we can.
1752 */
1753static void
1754ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1755{
1756 u32 mask, seq;
81616c5a 1757 struct channel *ch;
1da177e4
LT		 1758 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1759
2a38b775 1760 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
1da177e4
LT		 1761 goto err; /* no good, throw it away */
1762
1763 /* Decode sequence number and begin/end bits */
1764 if (ppp->flags & SC_MP_SHORTSEQ) {
1765 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1766 mask = 0xfff;
1767 } else {
1768 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1769 mask = 0xffffff;
1770 }
1771 skb->BEbits = skb->data[2];
1772 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
1773
1774 /*
1775 * Do protocol ID decompression on the first fragment of each packet.
1776 */
1777 if ((skb->BEbits & B) && (skb->data[0] & 1))
1778 *skb_push(skb, 1) = 0;
1779
1780 /*
1781 * Expand sequence number to 32 bits, making it as close
1782 * as possible to ppp->minseq.
1783 */
1784 seq |= ppp->minseq & ~mask;
1785 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
1786 seq += mask + 1;
1787 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
1788 seq -= mask + 1; /* should never happen */
1789 skb->sequence = seq;
1790 pch->lastseq = seq;
1791
1792 /*
1793 * If this packet comes before the next one we were expecting,
1794 * drop it.
1795 */
1796 if (seq_before(seq, ppp->nextseq)) {
1797 kfree_skb(skb);
8c0469cd 1798 ++ppp->dev->stats.rx_dropped;
1da177e4
LT		 1799 ppp_receive_error(ppp);
1800 return;
1801 }
1802
1803 /*
1804 * Reevaluate minseq, the minimum over all channels of the
1805 * last sequence number received on each channel. Because of
1806 * the increasing sequence number rule, we know that any fragment
1807 * before `minseq' which hasn't arrived is never going to arrive.
1808 * The list of channels can't change because we have the receive
1809 * side of the ppp unit locked.
1810 */
81616c5a 1811 list_for_each_entry(ch, &ppp->channels, clist) {
1da177e4
LT		 1812 if (seq_before(ch->lastseq, seq))
1813 seq = ch->lastseq;
1814 }
1815 if (seq_before(ppp->minseq, seq))
1816 ppp->minseq = seq;
1817
1818 /* Put the fragment on the reconstruction queue */
1819 ppp_mp_insert(ppp, skb);
1820
1821 /* If the queue is getting long, don't wait any longer for packets
1822 before the start of the queue. */
38ce7c73
DM		 1823 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
1824 struct sk_buff *skb = skb_peek(&ppp->mrq);
1825 if (seq_before(ppp->minseq, skb->sequence))
1826 ppp->minseq = skb->sequence;
1827 }
1da177e4
LT		 1828
1829 /* Pull completed packets off the queue and receive them. */
cd228d54 1830 while ((skb = ppp_mp_reconstruct(ppp)))
1da177e4
LT		 1831 ppp_receive_nonmp_frame(ppp, skb);
1832
1833 return;
1834
1835 err:
1836 kfree_skb(skb);
1837 ppp_receive_error(ppp);
1838}
1839
1840/*
1841 * Insert a fragment on the MP reconstruction queue.
1842 * The queue is ordered by increasing sequence number.
1843 */
1844static void
1845ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
1846{
1847 struct sk_buff *p;
1848 struct sk_buff_head *list = &ppp->mrq;
1849 u32 seq = skb->sequence;
1850
1851 /* N.B. we don't need to lock the list lock because we have the
1852 ppp unit receive-side lock. */
13c9821e 1853 skb_queue_walk(list, p) {
1da177e4
LT		 1854 if (seq_before(seq, p->sequence))
1855 break;
13c9821e 1856 }
43f59c89 1857 __skb_queue_before(list, p, skb);
1da177e4
LT		 1858}
1859
1860/*
1861 * Reconstruct a packet from the MP fragment queue.
1862 * We go through increasing sequence numbers until we find a
1863 * complete packet, or we get to the sequence number for a fragment
1864 * which hasn't arrived but might still do so.
1865 */
3c582b30 1866static struct sk_buff *
1da177e4
LT		 1867ppp_mp_reconstruct(struct ppp *ppp)
1868{
1869 u32 seq = ppp->nextseq;
1870 u32 minseq = ppp->minseq;
1871 struct sk_buff_head *list = &ppp->mrq;
1872 struct sk_buff *p, *next;
1873 struct sk_buff *head, *tail;
1874 struct sk_buff *skb = NULL;
1875 int lost = 0, len = 0;
1876
1877 if (ppp->mrru == 0) /* do nothing until mrru is set */
1878 return NULL;
1879 head = list->next;
1880 tail = NULL;
1881 for (p = head; p != (struct sk_buff *) list; p = next) {
1882 next = p->next;
1883 if (seq_before(p->sequence, seq)) {
1884 /* this can't happen, anyway ignore the skb */
1885 printk(KERN_ERR "ppp_mp_reconstruct bad seq %u < %u\n",
1886 p->sequence, seq);
1887 head = next;
1888 continue;
1889 }
1890 if (p->sequence != seq) {
1891 /* Fragment `seq' is missing. If it is after
1892 minseq, it might arrive later, so stop here. */
1893 if (seq_after(seq, minseq))
1894 break;
1895 /* Fragment `seq' is lost, keep going. */
1896 lost = 1;
1897 seq = seq_before(minseq, p->sequence)?
1898 minseq + 1: p->sequence;
1899 next = p;
1900 continue;
1901 }
1902
1903 /*
1904 * At this point we know that all the fragments from
1905 * ppp->nextseq to seq are either present or lost.
1906 * Also, there are no complete packets in the queue
1907 * that have no missing fragments and end before this
1908 * fragment.
1909 */
1910
1911 /* B bit set indicates this fragment starts a packet */
1912 if (p->BEbits & B) {
1913 head = p;
1914 lost = 0;
1915 len = 0;
1916 }
1917
1918 len += p->len;
1919
1920 /* Got a complete packet yet? */
1921 if (lost == 0 && (p->BEbits & E) && (head->BEbits & B)) {
1922 if (len > ppp->mrru + 2) {
8c0469cd 1923 ++ppp->dev->stats.rx_length_errors;
1da177e4
LT		 1924 printk(KERN_DEBUG "PPP: reconstructed packet"
1925 " is too long (%d)\n", len);
1926 } else if (p == head) {
1927 /* fragment is complete packet - reuse skb */
1928 tail = p;
1929 skb = skb_get(p);
1930 break;
1931 } else if ((skb = dev_alloc_skb(len)) == NULL) {
8c0469cd 1932 ++ppp->dev->stats.rx_missed_errors;
1da177e4
LT		 1933 printk(KERN_DEBUG "PPP: no memory for "
1934 "reconstructed packet");
1935 } else {
1936 tail = p;
1937 break;
1938 }
1939 ppp->nextseq = seq + 1;
1940 }
1941
1942 /*
1943 * If this is the ending fragment of a packet,
1944 * and we haven't found a complete valid packet yet,
1945 * we can discard up to and including this fragment.
1946 */
1947 if (p->BEbits & E)
1948 head = next;
1949
1950 ++seq;
1951 }
1952
1953 /* If we have a complete packet, copy it all into one skb. */
1954 if (tail != NULL) {
1955 /* If we have discarded any fragments,
1956 signal a receive error. */
1957 if (head->sequence != ppp->nextseq) {
1958 if (ppp->debug & 1)
1959 printk(KERN_DEBUG " missed pkts %u..%u\n",
1960 ppp->nextseq, head->sequence-1);
8c0469cd 1961 ++ppp->dev->stats.rx_dropped;
1da177e4
LT		 1962 ppp_receive_error(ppp);
1963 }
1964
1965 if (head != tail)
1966 /* copy to a single skb */
1967 for (p = head; p != tail->next; p = p->next)
1968 skb_copy_bits(p, 0, skb_put(skb, p->len), p->len);
1969 ppp->nextseq = tail->sequence + 1;
1970 head = tail->next;
1971 }
1972
1973 /* Discard all the skbuffs that we have copied the data out of
1974 or that we can't use. */
1975 while ((p = list->next) != head) {
1976 __skb_unlink(p, list);
1977 kfree_skb(p);
1978 }
1979
1980 return skb;
1981}
1982#endif /* CONFIG_PPP_MULTILINK */
1983
1984/*
1985 * Channel interface.
1986 */
1987
1988/*
1989 * Create a new, unattached ppp channel.
1990 */
1991int
1992ppp_register_channel(struct ppp_channel *chan)
1993{
1994 struct channel *pch;
1995
d4274b51 1996 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
cd228d54 1997 if (!pch)
1da177e4 1998 return -ENOMEM;
1da177e4
LT		 1999 pch->ppp = NULL;
2000 pch->chan = chan;
2001 chan->ppp = pch;
2002 init_ppp_file(&pch->file, CHANNEL);
2003 pch->file.hdrlen = chan->hdrlen;
2004#ifdef CONFIG_PPP_MULTILINK
2005 pch->lastseq = -1;
2006#endif /* CONFIG_PPP_MULTILINK */
2007 init_rwsem(&pch->chan_sem);
2008 spin_lock_init(&pch->downl);
2009 rwlock_init(&pch->upl);
2010 spin_lock_bh(&all_channels_lock);
2011 pch->file.index = ++last_channel_index;
2012 list_add(&pch->list, &new_channels);
2013 atomic_inc(&channel_count);
2014 spin_unlock_bh(&all_channels_lock);
2015 return 0;
2016}
2017
2018/*
2019 * Return the index of a channel.
2020 */
2021int ppp_channel_index(struct ppp_channel *chan)
2022{
2023 struct channel *pch = chan->ppp;
2024
cd228d54 2025 if (pch)
1da177e4
LT		 2026 return pch->file.index;
2027 return -1;
2028}
2029
2030/*
2031 * Return the PPP unit number to which a channel is connected.
2032 */
2033int ppp_unit_number(struct ppp_channel *chan)
2034{
2035 struct channel *pch = chan->ppp;
2036 int unit = -1;
2037
cd228d54 2038 if (pch) {
1da177e4 2039 read_lock_bh(&pch->upl);
cd228d54 2040 if (pch->ppp)
1da177e4
LT		 2041 unit = pch->ppp->file.index;
2042 read_unlock_bh(&pch->upl);
2043 }
2044 return unit;
2045}
2046
2047/*
2048 * Disconnect a channel from the generic layer.
2049 * This must be called in process context.
2050 */
2051void
2052ppp_unregister_channel(struct ppp_channel *chan)
2053{
2054 struct channel *pch = chan->ppp;
2055
cd228d54 2056 if (!pch)
1da177e4
LT		 2057 return; /* should never happen */
2058 chan->ppp = NULL;
2059
2060 /*
2061 * This ensures that we have returned from any calls into the
2062 * the channel's start_xmit or ioctl routine before we proceed.
2063 */
2064 down_write(&pch->chan_sem);
2065 spin_lock_bh(&pch->downl);
2066 pch->chan = NULL;
2067 spin_unlock_bh(&pch->downl);
2068 up_write(&pch->chan_sem);
2069 ppp_disconnect_channel(pch);
2070 spin_lock_bh(&all_channels_lock);
2071 list_del(&pch->list);
2072 spin_unlock_bh(&all_channels_lock);
2073 pch->file.dead = 1;
2074 wake_up_interruptible(&pch->file.rwait);
2075 if (atomic_dec_and_test(&pch->file.refcnt))
2076 ppp_destroy_channel(pch);
2077}
2078
2079/*
2080 * Callback from a channel when it can accept more to transmit.
2081 * This should be called at BH/softirq level, not interrupt level.
2082 */
2083void
2084ppp_output_wakeup(struct ppp_channel *chan)
2085{
2086 struct channel *pch = chan->ppp;
2087
cd228d54 2088 if (!pch)
1da177e4
LT		 2089 return;
2090 ppp_channel_push(pch);
2091}
2092
2093/*
2094 * Compression control.
2095 */
2096
2097/* Process the PPPIOCSCOMPRESS ioctl. */
2098static int
2099ppp_set_compress(struct ppp *ppp, unsigned long arg)
2100{
2101 int err;
2102 struct compressor *cp, *ocomp;
2103 struct ppp_option_data data;
2104 void *state, *ostate;
2105 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2106
2107 err = -EFAULT;
2108 if (copy_from_user(&data, (void __user *) arg, sizeof(data))
2109 || (data.length <= CCP_MAX_OPTION_LENGTH
2110 && copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2111 goto out;
2112 err = -EINVAL;
2113 if (data.length > CCP_MAX_OPTION_LENGTH
2114 || ccp_option[1] < 2 || ccp_option[1] > data.length)
2115 goto out;
2116
a65e5d78
JB		 2117 cp = try_then_request_module(
2118 find_compressor(ccp_option[0]),
2119 "ppp-compress-%d", ccp_option[0]);
cd228d54 2120 if (!cp)
1da177e4
LT		 2121 goto out;
2122
2123 err = -ENOBUFS;
2124 if (data.transmit) {
2125 state = cp->comp_alloc(ccp_option, data.length);
cd228d54 2126 if (state) {
1da177e4
LT		 2127 ppp_xmit_lock(ppp);
2128 ppp->xstate &= ~SC_COMP_RUN;
2129 ocomp = ppp->xcomp;
2130 ostate = ppp->xc_state;
2131 ppp->xcomp = cp;
2132 ppp->xc_state = state;
2133 ppp_xmit_unlock(ppp);
cd228d54 2134 if (ostate) {
1da177e4
LT		 2135 ocomp->comp_free(ostate);
2136 module_put(ocomp->owner);
2137 }
2138 err = 0;
2139 } else
2140 module_put(cp->owner);
2141
2142 } else {
2143 state = cp->decomp_alloc(ccp_option, data.length);
cd228d54 2144 if (state) {
1da177e4
LT		 2145 ppp_recv_lock(ppp);
2146 ppp->rstate &= ~SC_DECOMP_RUN;
2147 ocomp = ppp->rcomp;
2148 ostate = ppp->rc_state;
2149 ppp->rcomp = cp;
2150 ppp->rc_state = state;
2151 ppp_recv_unlock(ppp);
cd228d54 2152 if (ostate) {
1da177e4
LT		 2153 ocomp->decomp_free(ostate);
2154 module_put(ocomp->owner);
2155 }
2156 err = 0;
2157 } else
2158 module_put(cp->owner);
2159 }
2160
2161 out:
2162 return err;
2163}
2164
2165/*
2166 * Look at a CCP packet and update our state accordingly.
2167 * We assume the caller has the xmit or recv path locked.
2168 */
2169static void
2170ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2171{
2172 unsigned char *dp;
2173 int len;
2174
2175 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2176 return; /* no header */
2177 dp = skb->data + 2;
2178
2179 switch (CCP_CODE(dp)) {
2180 case CCP_CONFREQ:
2181
6aa20a22 2182 /* A ConfReq starts negotiation of compression
1da177e4
LT		 2183 * in one direction of transmission,
2184 * and hence brings it down...but which way?
2185 *
2186 * Remember:
2187 * A ConfReq indicates what the sender would like to receive
2188 */
2189 if(inbound)
2190 /* He is proposing what I should send */
2191 ppp->xstate &= ~SC_COMP_RUN;
6aa20a22 2192 else
1da177e4
LT		 2193 /* I am proposing to what he should send */
2194 ppp->rstate &= ~SC_DECOMP_RUN;
6aa20a22 2195
1da177e4 2196 break;
6aa20a22 2197
1da177e4
LT		 2198 case CCP_TERMREQ:
2199 case CCP_TERMACK:
2200 /*
6aa20a22 2201 * CCP is going down, both directions of transmission
1da177e4
LT		 2202 */
2203 ppp->rstate &= ~SC_DECOMP_RUN;
2204 ppp->xstate &= ~SC_COMP_RUN;
2205 break;
2206
2207 case CCP_CONFACK:
2208 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2209 break;
2210 len = CCP_LENGTH(dp);
2211 if (!pskb_may_pull(skb, len + 2))
2212 return; /* too short */
2213 dp += CCP_HDRLEN;
2214 len -= CCP_HDRLEN;
2215 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2216 break;
2217 if (inbound) {
2218 /* we will start receiving compressed packets */
cd228d54 2219 if (!ppp->rc_state)
1da177e4
LT		 2220 break;
2221 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2222 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2223 ppp->rstate |= SC_DECOMP_RUN;
2224 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2225 }
2226 } else {
2227 /* we will soon start sending compressed packets */
cd228d54 2228 if (!ppp->xc_state)
1da177e4
LT		 2229 break;
2230 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2231 ppp->file.index, 0, ppp->debug))
2232 ppp->xstate |= SC_COMP_RUN;
2233 }
2234 break;
2235
2236 case CCP_RESETACK:
2237 /* reset the [de]compressor */
2238 if ((ppp->flags & SC_CCP_UP) == 0)
2239 break;
2240 if (inbound) {
2241 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2242 ppp->rcomp->decomp_reset(ppp->rc_state);
2243 ppp->rstate &= ~SC_DC_ERROR;
2244 }
2245 } else {
2246 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2247 ppp->xcomp->comp_reset(ppp->xc_state);
2248 }
2249 break;
2250 }
2251}
2252
2253/* Free up compression resources. */
2254static void
2255ppp_ccp_closed(struct ppp *ppp)
2256{
2257 void *xstate, *rstate;
2258 struct compressor *xcomp, *rcomp;
2259
2260 ppp_lock(ppp);
2261 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2262 ppp->xstate = 0;
2263 xcomp = ppp->xcomp;
2264 xstate = ppp->xc_state;
2265 ppp->xc_state = NULL;
2266 ppp->rstate = 0;
2267 rcomp = ppp->rcomp;
2268 rstate = ppp->rc_state;
2269 ppp->rc_state = NULL;
2270 ppp_unlock(ppp);
2271
2272 if (xstate) {
2273 xcomp->comp_free(xstate);
2274 module_put(xcomp->owner);
2275 }
2276 if (rstate) {
2277 rcomp->decomp_free(rstate);
2278 module_put(rcomp->owner);
2279 }
2280}
2281
2282/* List of compressors. */
2283static LIST_HEAD(compressor_list);
2284static DEFINE_SPINLOCK(compressor_list_lock);
2285
2286struct compressor_entry {
2287 struct list_head list;
2288 struct compressor *comp;
2289};
2290
2291static struct compressor_entry *
2292find_comp_entry(int proto)
2293{
2294 struct compressor_entry *ce;
1da177e4 2295
81616c5a 2296 list_for_each_entry(ce, &compressor_list, list) {
1da177e4
LT		 2297 if (ce->comp->compress_proto == proto)
2298 return ce;
2299 }
2300 return NULL;
2301}
2302
2303/* Register a compressor */
2304int
2305ppp_register_compressor(struct compressor *cp)
2306{
2307 struct compressor_entry *ce;
2308 int ret;
2309 spin_lock(&compressor_list_lock);
2310 ret = -EEXIST;
cd228d54 2311 if (find_comp_entry(cp->compress_proto))
1da177e4
LT		 2312 goto out;
2313 ret = -ENOMEM;
2314 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
cd228d54 2315 if (!ce)
1da177e4
LT		 2316 goto out;
2317 ret = 0;
2318 ce->comp = cp;
2319 list_add(&ce->list, &compressor_list);
2320 out:
2321 spin_unlock(&compressor_list_lock);
2322 return ret;
2323}
2324
2325/* Unregister a compressor */
2326void
2327ppp_unregister_compressor(struct compressor *cp)
2328{
2329 struct compressor_entry *ce;
2330
2331 spin_lock(&compressor_list_lock);
2332 ce = find_comp_entry(cp->compress_proto);
cd228d54 2333 if (ce && ce->comp == cp) {
1da177e4
LT		 2334 list_del(&ce->list);
2335 kfree(ce);
2336 }
2337 spin_unlock(&compressor_list_lock);
2338}
2339
2340/* Find a compressor. */
2341static struct compressor *
2342find_compressor(int type)
2343{
2344 struct compressor_entry *ce;
2345 struct compressor *cp = NULL;
2346
2347 spin_lock(&compressor_list_lock);
2348 ce = find_comp_entry(type);
cd228d54 2349 if (ce) {
1da177e4
LT		 2350 cp = ce->comp;
2351 if (!try_module_get(cp->owner))
2352 cp = NULL;
2353 }
2354 spin_unlock(&compressor_list_lock);
2355 return cp;
2356}
2357
2358/*
2359 * Miscelleneous stuff.
2360 */
2361
2362static void
2363ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2364{
2365 struct slcompress *vj = ppp->vj;
2366
2367 memset(st, 0, sizeof(*st));
8c0469cd
PZ		 2368 st->p.ppp_ipackets = ppp->dev->stats.rx_packets;
2369 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2370 st->p.ppp_ibytes = ppp->dev->stats.rx_bytes;
2371 st->p.ppp_opackets = ppp->dev->stats.tx_packets;
2372 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2373 st->p.ppp_obytes = ppp->dev->stats.tx_bytes;
cd228d54 2374 if (!vj)
1da177e4
LT		 2375 return;
2376 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2377 st->vj.vjs_compressed = vj->sls_o_compressed;
2378 st->vj.vjs_searches = vj->sls_o_searches;
2379 st->vj.vjs_misses = vj->sls_o_misses;
2380 st->vj.vjs_errorin = vj->sls_i_error;
2381 st->vj.vjs_tossed = vj->sls_i_tossed;
2382 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2383 st->vj.vjs_compressedin = vj->sls_i_compressed;
2384}
2385
2386/*
2387 * Stuff for handling the lists of ppp units and channels
2388 * and for initialization.
2389 */
2390
2391/*
2392 * Create a new ppp interface unit. Fails if it can't allocate memory
2393 * or if there is already a unit with the requested number.
2394 * unit == -1 means allocate a new number.
2395 */
2396static struct ppp *
2397ppp_create_interface(int unit, int *retp)
2398{
2399 struct ppp *ppp;
2400 struct net_device *dev = NULL;
2401 int ret = -ENOMEM;
2402 int i;
2403
c8019bf3 2404 dev = alloc_netdev(sizeof(struct ppp), "", ppp_setup);
1da177e4
LT		 2405 if (!dev)
2406 goto out1;
1da177e4 2407
c8019bf3
WC		 2408 ppp = netdev_priv(dev);
2409 ppp->dev = dev;
1da177e4
LT		 2410 ppp->mru = PPP_MRU;
2411 init_ppp_file(&ppp->file, INTERFACE);
2412 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2413 for (i = 0; i < NUM_NP; ++i)
2414 ppp->npmode[i] = NPMODE_PASS;
2415 INIT_LIST_HEAD(&ppp->channels);
2416 spin_lock_init(&ppp->rlock);
2417 spin_lock_init(&ppp->wlock);
2418#ifdef CONFIG_PPP_MULTILINK
2419 ppp->minseq = -1;
2420 skb_queue_head_init(&ppp->mrq);
2421#endif /* CONFIG_PPP_MULTILINK */
1da177e4 2422
1da177e4 2423 ret = -EEXIST;
8ed965d6 2424 mutex_lock(&all_ppp_mutex);
7a95d267
CG		 2425
2426 if (unit < 0) {
2427 unit = unit_get(&ppp_units_idr, ppp);
2428 if (unit < 0) {
2429 *retp = unit;
2430 goto out2;
2431 }
2432 } else {
2433 if (unit_find(&ppp_units_idr, unit))
2434 goto out2; /* unit already exists */
2435 else {
ab5024ab 2436 /* darn, someone is cheating us? */
7a95d267
CG		 2437 *retp = -EINVAL;
2438 goto out2;
2439 }
2440 }
1da177e4
LT		 2441
2442 /* Initialize the new ppp unit */
2443 ppp->file.index = unit;
2444 sprintf(dev->name, "ppp%d", unit);
2445
2446 ret = register_netdev(dev);
2447 if (ret != 0) {
7a95d267 2448 unit_put(&ppp_units_idr, unit);
1da177e4
LT		 2449 printk(KERN_ERR "PPP: couldn't register device %s (%d)\n",
2450 dev->name, ret);
2451 goto out2;
2452 }
2453
2454 atomic_inc(&ppp_unit_count);
8ed965d6 2455 mutex_unlock(&all_ppp_mutex);
7a95d267 2456
1da177e4
LT		 2457 *retp = 0;
2458 return ppp;
2459
2460out2:
8ed965d6 2461 mutex_unlock(&all_ppp_mutex);
1da177e4
LT		 2462 free_netdev(dev);
2463out1:
1da177e4
LT		 2464 *retp = ret;
2465 return NULL;
2466}
2467
2468/*
2469 * Initialize a ppp_file structure.
2470 */
2471static void
2472init_ppp_file(struct ppp_file *pf, int kind)
2473{
2474 pf->kind = kind;
2475 skb_queue_head_init(&pf->xq);
2476 skb_queue_head_init(&pf->rq);
2477 atomic_set(&pf->refcnt, 1);
2478 init_waitqueue_head(&pf->rwait);
2479}
2480
2481/*
2482 * Take down a ppp interface unit - called when the owning file
2483 * (the one that created the unit) is closed or detached.
2484 */
2485static void ppp_shutdown_interface(struct ppp *ppp)
2486{
8ed965d6 2487 mutex_lock(&all_ppp_mutex);
1da177e4 2488 /* This will call dev_close() for us. */
739840d5
JC		 2489 ppp_lock(ppp);
2490 if (!ppp->closing) {
2491 ppp->closing = 1;
2492 ppp_unlock(ppp);
2493 unregister_netdev(ppp->dev);
2494 } else
2495 ppp_unlock(ppp);
2496
7a95d267 2497 unit_put(&ppp_units_idr, ppp->file.index);
1da177e4
LT		 2498 ppp->file.dead = 1;
2499 ppp->owner = NULL;
2500 wake_up_interruptible(&ppp->file.rwait);
8ed965d6 2501 mutex_unlock(&all_ppp_mutex);
1da177e4
LT		 2502}
2503
2504/*
2505 * Free the memory used by a ppp unit. This is only called once
2506 * there are no channels connected to the unit and no file structs
2507 * that reference the unit.
2508 */
2509static void ppp_destroy_interface(struct ppp *ppp)
2510{
2511 atomic_dec(&ppp_unit_count);
2512
2513 if (!ppp->file.dead || ppp->n_channels) {
2514 /* "can't happen" */
2515 printk(KERN_ERR "ppp: destroying ppp struct %p but dead=%d "
2516 "n_channels=%d !\n", ppp, ppp->file.dead,
2517 ppp->n_channels);
2518 return;
2519 }
2520
2521 ppp_ccp_closed(ppp);
2522 if (ppp->vj) {
2523 slhc_free(ppp->vj);
2524 ppp->vj = NULL;
2525 }
2526 skb_queue_purge(&ppp->file.xq);
2527 skb_queue_purge(&ppp->file.rq);
2528#ifdef CONFIG_PPP_MULTILINK
2529 skb_queue_purge(&ppp->mrq);
2530#endif /* CONFIG_PPP_MULTILINK */
2531#ifdef CONFIG_PPP_FILTER
96edf83c
JJ		 2532 kfree(ppp->pass_filter);
2533 ppp->pass_filter = NULL;
2534 kfree(ppp->active_filter);
2535 ppp->active_filter = NULL;
1da177e4
LT		 2536#endif /* CONFIG_PPP_FILTER */
2537
165de5b7
L		 2538 if (ppp->xmit_pending)
2539 kfree_skb(ppp->xmit_pending);
2540
739840d5 2541 free_netdev(ppp->dev);
1da177e4
LT		 2542}
2543
2544/*
2545 * Locate an existing ppp unit.
8ed965d6 2546 * The caller should have locked the all_ppp_mutex.
1da177e4
LT		 2547 */
2548static struct ppp *
2549ppp_find_unit(int unit)
2550{
7a95d267 2551 return unit_find(&ppp_units_idr, unit);
1da177e4
LT		 2552}
2553
2554/*
2555 * Locate an existing ppp channel.
2556 * The caller should have locked the all_channels_lock.
2557 * First we look in the new_channels list, then in the
2558 * all_channels list. If found in the new_channels list,
2559 * we move it to the all_channels list. This is for speed
2560 * when we have a lot of channels in use.
2561 */
2562static struct channel *
2563ppp_find_channel(int unit)
2564{
2565 struct channel *pch;
1da177e4 2566
81616c5a 2567 list_for_each_entry(pch, &new_channels, list) {
1da177e4 2568 if (pch->file.index == unit) {
179e0917 2569 list_move(&pch->list, &all_channels);
1da177e4
LT		 2570 return pch;
2571 }
2572 }
81616c5a 2573 list_for_each_entry(pch, &all_channels, list) {
1da177e4
LT		 2574 if (pch->file.index == unit)
2575 return pch;
2576 }
2577 return NULL;
2578}
2579
2580/*
2581 * Connect a PPP channel to a PPP interface unit.
2582 */
2583static int
2584ppp_connect_channel(struct channel *pch, int unit)
2585{
2586 struct ppp *ppp;
2587 int ret = -ENXIO;
2588 int hdrlen;
2589
8ed965d6 2590 mutex_lock(&all_ppp_mutex);
1da177e4 2591 ppp = ppp_find_unit(unit);
cd228d54 2592 if (!ppp)
1da177e4
LT		 2593 goto out;
2594 write_lock_bh(&pch->upl);
2595 ret = -EINVAL;
cd228d54 2596 if (pch->ppp)
1da177e4
LT		 2597 goto outl;
2598
2599 ppp_lock(ppp);
2600 if (pch->file.hdrlen > ppp->file.hdrlen)
2601 ppp->file.hdrlen = pch->file.hdrlen;
2602 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
739840d5 2603 if (hdrlen > ppp->dev->hard_header_len)
1da177e4
LT		 2604 ppp->dev->hard_header_len = hdrlen;
2605 list_add_tail(&pch->clist, &ppp->channels);
2606 ++ppp->n_channels;
2607 pch->ppp = ppp;
2608 atomic_inc(&ppp->file.refcnt);
2609 ppp_unlock(ppp);
2610 ret = 0;
2611
2612 outl:
2613 write_unlock_bh(&pch->upl);
2614 out:
8ed965d6 2615 mutex_unlock(&all_ppp_mutex);
1da177e4
LT		 2616 return ret;
2617}
2618
2619/*
2620 * Disconnect a channel from its ppp unit.
2621 */
2622static int
2623ppp_disconnect_channel(struct channel *pch)
2624{
2625 struct ppp *ppp;
2626 int err = -EINVAL;
2627
2628 write_lock_bh(&pch->upl);
2629 ppp = pch->ppp;
2630 pch->ppp = NULL;
2631 write_unlock_bh(&pch->upl);
cd228d54 2632 if (ppp) {
1da177e4
LT		 2633 /* remove it from the ppp unit's list */
2634 ppp_lock(ppp);
2635 list_del(&pch->clist);
2636 if (--ppp->n_channels == 0)
2637 wake_up_interruptible(&ppp->file.rwait);
2638 ppp_unlock(ppp);
2639 if (atomic_dec_and_test(&ppp->file.refcnt))
2640 ppp_destroy_interface(ppp);
2641 err = 0;
2642 }
2643 return err;
2644}
2645
2646/*
2647 * Free up the resources used by a ppp channel.
2648 */
2649static void ppp_destroy_channel(struct channel *pch)
2650{
2651 atomic_dec(&channel_count);
2652
2653 if (!pch->file.dead) {
2654 /* "can't happen" */
2655 printk(KERN_ERR "ppp: destroying undead channel %p !\n",
2656 pch);
2657 return;
2658 }
2659 skb_queue_purge(&pch->file.xq);
2660 skb_queue_purge(&pch->file.rq);
2661 kfree(pch);
2662}
2663
2664static void __exit ppp_cleanup(void)
2665{
2666 /* should never happen */
2667 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2668 printk(KERN_ERR "PPP: removing module but units remain!\n");
68fc4fab 2669 unregister_chrdev(PPP_MAJOR, "ppp");
9a6a2a5e 2670 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
56b22935 2671 class_destroy(ppp_class);
7a95d267 2672 idr_destroy(&ppp_units_idr);
1da177e4
LT		 2673}
2674
2675/*
7a95d267
CG		 2676 * Units handling. Caller must protect concurrent access
2677 * by holding all_ppp_mutex
1da177e4 2678 */
7a95d267
CG		 2679
2680/* get new free unit number and associate pointer with it */
2681static int unit_get(struct idr *p, void *ptr)
1da177e4 2682{
7a95d267 2683 int unit, err;
1da177e4 2684
7a95d267
CG		 2685again:
2686 if (idr_pre_get(p, GFP_KERNEL) == 0) {
2687 printk(KERN_ERR "Out of memory expanding drawable idr\n");
2688 return -ENOMEM;
1da177e4 2689 }
1da177e4 2690
7a95d267
CG		 2691 err = idr_get_new_above(p, ptr, 0, &unit);
2692 if (err == -EAGAIN)
2693 goto again;
1da177e4 2694
7a95d267 2695 return unit;
1da177e4
LT		 2696}
2697
7a95d267
CG		 2698/* put unit number back to a pool */
2699static void unit_put(struct idr *p, int n)
1da177e4 2700{
7a95d267 2701 idr_remove(p, n);
1da177e4
LT		 2702}
2703
7a95d267
CG		 2704/* get pointer associated with the number */
2705static void *unit_find(struct idr *p, int n)
1da177e4 2706{
7a95d267 2707 return idr_find(p, n);
1da177e4
LT		 2708}
2709
2710/* Module/initialization stuff */
2711
2712module_init(ppp_init);
2713module_exit(ppp_cleanup);
2714
2715EXPORT_SYMBOL(ppp_register_channel);
2716EXPORT_SYMBOL(ppp_unregister_channel);
2717EXPORT_SYMBOL(ppp_channel_index);
2718EXPORT_SYMBOL(ppp_unit_number);
2719EXPORT_SYMBOL(ppp_input);
2720EXPORT_SYMBOL(ppp_input_error);
2721EXPORT_SYMBOL(ppp_output_wakeup);
2722EXPORT_SYMBOL(ppp_register_compressor);
2723EXPORT_SYMBOL(ppp_unregister_compressor);
2724MODULE_LICENSE("GPL");
2725MODULE_ALIAS_CHARDEV_MAJOR(PPP_MAJOR);
2726MODULE_ALIAS("/dev/ppp");
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