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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg...
[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 252static int unit_get(struct idr *p, void *ptr);
85997576 253static int unit_set(struct idr *p, void *ptr, int n);
7a95d267
CG		 254static void unit_put(struct idr *p, int n);
255static void *unit_find(struct idr *p, int n);
1da177e4 256
56b22935 257static struct class *ppp_class;
1da177e4
LT		 258
259/* Translates a PPP protocol number to a NP index (NP == network protocol) */
260static inline int proto_to_npindex(int proto)
261{
262 switch (proto) {
263 case PPP_IP:
264 return NP_IP;
265 case PPP_IPV6:
266 return NP_IPV6;
267 case PPP_IPX:
268 return NP_IPX;
269 case PPP_AT:
270 return NP_AT;
271 case PPP_MPLS_UC:
272 return NP_MPLS_UC;
273 case PPP_MPLS_MC:
274 return NP_MPLS_MC;
275 }
276 return -EINVAL;
277}
278
279/* Translates an NP index into a PPP protocol number */
280static const int npindex_to_proto[NUM_NP] = {
281 PPP_IP,
282 PPP_IPV6,
283 PPP_IPX,
284 PPP_AT,
285 PPP_MPLS_UC,
286 PPP_MPLS_MC,
287};
6aa20a22 288
1da177e4
LT		 289/* Translates an ethertype into an NP index */
290static inline int ethertype_to_npindex(int ethertype)
291{
292 switch (ethertype) {
293 case ETH_P_IP:
294 return NP_IP;
295 case ETH_P_IPV6:
296 return NP_IPV6;
297 case ETH_P_IPX:
298 return NP_IPX;
299 case ETH_P_PPPTALK:
300 case ETH_P_ATALK:
301 return NP_AT;
302 case ETH_P_MPLS_UC:
303 return NP_MPLS_UC;
304 case ETH_P_MPLS_MC:
305 return NP_MPLS_MC;
306 }
307 return -1;
308}
309
310/* Translates an NP index into an ethertype */
311static const int npindex_to_ethertype[NUM_NP] = {
312 ETH_P_IP,
313 ETH_P_IPV6,
314 ETH_P_IPX,
315 ETH_P_PPPTALK,
316 ETH_P_MPLS_UC,
317 ETH_P_MPLS_MC,
318};
319
320/*
321 * Locking shorthand.
322 */
323#define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
324#define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
325#define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
326#define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
327#define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
328 ppp_recv_lock(ppp); } while (0)
329#define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
330 ppp_xmit_unlock(ppp); } while (0)
331
332/*
333 * /dev/ppp device routines.
334 * The /dev/ppp device is used by pppd to control the ppp unit.
335 * It supports the read, write, ioctl and poll functions.
336 * Open instances of /dev/ppp can be in one of three states:
337 * unattached, attached to a ppp unit, or attached to a ppp channel.
338 */
339static int ppp_open(struct inode *inode, struct file *file)
340{
f2b9857e 341 cycle_kernel_lock();
1da177e4
LT		 342 /*
343 * This could (should?) be enforced by the permissions on /dev/ppp.
344 */
345 if (!capable(CAP_NET_ADMIN))
346 return -EPERM;
347 return 0;
348}
349
f3ff8a4d 350static int ppp_release(struct inode *unused, struct file *file)
1da177e4
LT		 351{
352 struct ppp_file *pf = file->private_data;
353 struct ppp *ppp;
354
cd228d54 355 if (pf) {
1da177e4
LT		 356 file->private_data = NULL;
357 if (pf->kind == INTERFACE) {
358 ppp = PF_TO_PPP(pf);
359 if (file == ppp->owner)
360 ppp_shutdown_interface(ppp);
361 }
362 if (atomic_dec_and_test(&pf->refcnt)) {
363 switch (pf->kind) {
364 case INTERFACE:
365 ppp_destroy_interface(PF_TO_PPP(pf));
366 break;
367 case CHANNEL:
368 ppp_destroy_channel(PF_TO_CHANNEL(pf));
369 break;
370 }
371 }
372 }
373 return 0;
374}
375
376static ssize_t ppp_read(struct file *file, char __user *buf,
377 size_t count, loff_t *ppos)
378{
379 struct ppp_file *pf = file->private_data;
380 DECLARE_WAITQUEUE(wait, current);
381 ssize_t ret;
382 struct sk_buff *skb = NULL;
383
384 ret = count;
385
cd228d54 386 if (!pf)
1da177e4
LT		 387 return -ENXIO;
388 add_wait_queue(&pf->rwait, &wait);
389 for (;;) {
390 set_current_state(TASK_INTERRUPTIBLE);
391 skb = skb_dequeue(&pf->rq);
392 if (skb)
393 break;
394 ret = 0;
395 if (pf->dead)
396 break;
397 if (pf->kind == INTERFACE) {
398 /*
399 * Return 0 (EOF) on an interface that has no
400 * channels connected, unless it is looping
401 * network traffic (demand mode).
402 */
403 struct ppp *ppp = PF_TO_PPP(pf);
404 if (ppp->n_channels == 0
405 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
406 break;
407 }
408 ret = -EAGAIN;
409 if (file->f_flags & O_NONBLOCK)
410 break;
411 ret = -ERESTARTSYS;
412 if (signal_pending(current))
413 break;
414 schedule();
415 }
416 set_current_state(TASK_RUNNING);
417 remove_wait_queue(&pf->rwait, &wait);
418
cd228d54 419 if (!skb)
1da177e4
LT		 420 goto out;
421
422 ret = -EOVERFLOW;
423 if (skb->len > count)
424 goto outf;
425 ret = -EFAULT;
426 if (copy_to_user(buf, skb->data, skb->len))
427 goto outf;
428 ret = skb->len;
429
430 outf:
431 kfree_skb(skb);
432 out:
433 return ret;
434}
435
436static ssize_t ppp_write(struct file *file, const char __user *buf,
437 size_t count, loff_t *ppos)
438{
439 struct ppp_file *pf = file->private_data;
440 struct sk_buff *skb;
441 ssize_t ret;
442
cd228d54 443 if (!pf)
1da177e4
LT		 444 return -ENXIO;
445 ret = -ENOMEM;
446 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
cd228d54 447 if (!skb)
1da177e4
LT		 448 goto out;
449 skb_reserve(skb, pf->hdrlen);
450 ret = -EFAULT;
451 if (copy_from_user(skb_put(skb, count), buf, count)) {
452 kfree_skb(skb);
453 goto out;
454 }
455
456 skb_queue_tail(&pf->xq, skb);
457
458 switch (pf->kind) {
459 case INTERFACE:
460 ppp_xmit_process(PF_TO_PPP(pf));
461 break;
462 case CHANNEL:
463 ppp_channel_push(PF_TO_CHANNEL(pf));
464 break;
465 }
466
467 ret = count;
468
469 out:
470 return ret;
471}
472
473/* No kernel lock - fine */
474static unsigned int ppp_poll(struct file *file, poll_table *wait)
475{
476 struct ppp_file *pf = file->private_data;
477 unsigned int mask;
478
cd228d54 479 if (!pf)
1da177e4
LT		 480 return 0;
481 poll_wait(file, &pf->rwait, wait);
482 mask = POLLOUT | POLLWRNORM;
cd228d54 483 if (skb_peek(&pf->rq))
1da177e4
LT		 484 mask |= POLLIN | POLLRDNORM;
485 if (pf->dead)
486 mask |= POLLHUP;
487 else if (pf->kind == INTERFACE) {
488 /* see comment in ppp_read */
489 struct ppp *ppp = PF_TO_PPP(pf);
490 if (ppp->n_channels == 0
491 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
492 mask |= POLLIN | POLLRDNORM;
493 }
494
495 return mask;
496}
497
498#ifdef CONFIG_PPP_FILTER
499static int get_filter(void __user *arg, struct sock_filter **p)
500{
501 struct sock_fprog uprog;
502 struct sock_filter *code = NULL;
503 int len, err;
504
505 if (copy_from_user(&uprog, arg, sizeof(uprog)))
506 return -EFAULT;
507
1da177e4
LT		 508 if (!uprog.len) {
509 *p = NULL;
510 return 0;
511 }
512
513 len = uprog.len * sizeof(struct sock_filter);
514 code = kmalloc(len, GFP_KERNEL);
515 if (code == NULL)
516 return -ENOMEM;
517
518 if (copy_from_user(code, uprog.filter, len)) {
519 kfree(code);
520 return -EFAULT;
521 }
522
523 err = sk_chk_filter(code, uprog.len);
524 if (err) {
525 kfree(code);
526 return err;
527 }
528
529 *p = code;
530 return uprog.len;
531}
532#endif /* CONFIG_PPP_FILTER */
533
f3ff8a4d 534static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1da177e4
LT		 535{
536 struct ppp_file *pf = file->private_data;
537 struct ppp *ppp;
538 int err = -EFAULT, val, val2, i;
539 struct ppp_idle idle;
540 struct npioctl npi;
541 int unit, cflags;
542 struct slcompress *vj;
543 void __user *argp = (void __user *)arg;
544 int __user *p = argp;
545
cd228d54 546 if (!pf)
1da177e4
LT		 547 return ppp_unattached_ioctl(pf, file, cmd, arg);
548
549 if (cmd == PPPIOCDETACH) {
550 /*
551 * We have to be careful here... if the file descriptor
552 * has been dup'd, we could have another process in the
553 * middle of a poll using the same file *, so we had
554 * better not free the interface data structures -
555 * instead we fail the ioctl. Even in this case, we
556 * shut down the interface if we are the owner of it.
557 * Actually, we should get rid of PPPIOCDETACH, userland
558 * (i.e. pppd) could achieve the same effect by closing
559 * this fd and reopening /dev/ppp.
560 */
561 err = -EINVAL;
f3ff8a4d 562 lock_kernel();
1da177e4
LT		 563 if (pf->kind == INTERFACE) {
564 ppp = PF_TO_PPP(pf);
565 if (file == ppp->owner)
566 ppp_shutdown_interface(ppp);
567 }
516e0cc5 568 if (atomic_long_read(&file->f_count) <= 2) {
f3ff8a4d 569 ppp_release(NULL, file);
1da177e4
LT		 570 err = 0;
571 } else
516e0cc5
AV		 572 printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%ld\n",
573 atomic_long_read(&file->f_count));
f3ff8a4d 574 unlock_kernel();
1da177e4
LT		 575 return err;
576 }
577
578 if (pf->kind == CHANNEL) {
f3ff8a4d 579 struct channel *pch;
1da177e4
LT		 580 struct ppp_channel *chan;
581
f3ff8a4d
AC		 582 lock_kernel();
583 pch = PF_TO_CHANNEL(pf);
584
1da177e4
LT		 585 switch (cmd) {
586 case PPPIOCCONNECT:
587 if (get_user(unit, p))
588 break;
589 err = ppp_connect_channel(pch, unit);
590 break;
591
592 case PPPIOCDISCONN:
593 err = ppp_disconnect_channel(pch);
594 break;
595
596 default:
597 down_read(&pch->chan_sem);
598 chan = pch->chan;
599 err = -ENOTTY;
600 if (chan && chan->ops->ioctl)
601 err = chan->ops->ioctl(chan, cmd, arg);
602 up_read(&pch->chan_sem);
603 }
f3ff8a4d 604 unlock_kernel();
1da177e4
LT		 605 return err;
606 }
607
608 if (pf->kind != INTERFACE) {
609 /* can't happen */
610 printk(KERN_ERR "PPP: not interface or channel??\n");
611 return -EINVAL;
612 }
613
f3ff8a4d 614 lock_kernel();
1da177e4
LT		 615 ppp = PF_TO_PPP(pf);
616 switch (cmd) {
617 case PPPIOCSMRU:
618 if (get_user(val, p))
619 break;
620 ppp->mru = val;
621 err = 0;
622 break;
623
624 case PPPIOCSFLAGS:
625 if (get_user(val, p))
626 break;
627 ppp_lock(ppp);
628 cflags = ppp->flags & ~val;
629 ppp->flags = val & SC_FLAG_BITS;
630 ppp_unlock(ppp);
631 if (cflags & SC_CCP_OPEN)
632 ppp_ccp_closed(ppp);
633 err = 0;
634 break;
635
636 case PPPIOCGFLAGS:
637 val = ppp->flags | ppp->xstate | ppp->rstate;
638 if (put_user(val, p))
639 break;
640 err = 0;
641 break;
642
643 case PPPIOCSCOMPRESS:
644 err = ppp_set_compress(ppp, arg);
645 break;
646
647 case PPPIOCGUNIT:
648 if (put_user(ppp->file.index, p))
649 break;
650 err = 0;
651 break;
652
653 case PPPIOCSDEBUG:
654 if (get_user(val, p))
655 break;
656 ppp->debug = val;
657 err = 0;
658 break;
659
660 case PPPIOCGDEBUG:
661 if (put_user(ppp->debug, p))
662 break;
663 err = 0;
664 break;
665
666 case PPPIOCGIDLE:
667 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
668 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
669 if (copy_to_user(argp, &idle, sizeof(idle)))
670 break;
671 err = 0;
672 break;
673
674 case PPPIOCSMAXCID:
675 if (get_user(val, p))
676 break;
677 val2 = 15;
678 if ((val >> 16) != 0) {
679 val2 = val >> 16;
680 val &= 0xffff;
681 }
682 vj = slhc_init(val2+1, val+1);
cd228d54 683 if (!vj) {
1da177e4
LT		 684 printk(KERN_ERR "PPP: no memory (VJ compressor)\n");
685 err = -ENOMEM;
686 break;
687 }
688 ppp_lock(ppp);
cd228d54 689 if (ppp->vj)
1da177e4
LT		 690 slhc_free(ppp->vj);
691 ppp->vj = vj;
692 ppp_unlock(ppp);
693 err = 0;
694 break;
695
696 case PPPIOCGNPMODE:
697 case PPPIOCSNPMODE:
698 if (copy_from_user(&npi, argp, sizeof(npi)))
699 break;
700 err = proto_to_npindex(npi.protocol);
701 if (err < 0)
702 break;
703 i = err;
704 if (cmd == PPPIOCGNPMODE) {
705 err = -EFAULT;
706 npi.mode = ppp->npmode[i];
707 if (copy_to_user(argp, &npi, sizeof(npi)))
708 break;
709 } else {
710 ppp->npmode[i] = npi.mode;
711 /* we may be able to transmit more packets now (??) */
712 netif_wake_queue(ppp->dev);
713 }
714 err = 0;
715 break;
716
717#ifdef CONFIG_PPP_FILTER
718 case PPPIOCSPASS:
719 {
720 struct sock_filter *code;
721 err = get_filter(argp, &code);
722 if (err >= 0) {
723 ppp_lock(ppp);
724 kfree(ppp->pass_filter);
725 ppp->pass_filter = code;
726 ppp->pass_len = err;
727 ppp_unlock(ppp);
728 err = 0;
729 }
730 break;
731 }
732 case PPPIOCSACTIVE:
733 {
734 struct sock_filter *code;
735 err = get_filter(argp, &code);
736 if (err >= 0) {
737 ppp_lock(ppp);
738 kfree(ppp->active_filter);
739 ppp->active_filter = code;
740 ppp->active_len = err;
741 ppp_unlock(ppp);
742 err = 0;
743 }
744 break;
745 }
746#endif /* CONFIG_PPP_FILTER */
747
748#ifdef CONFIG_PPP_MULTILINK
749 case PPPIOCSMRRU:
750 if (get_user(val, p))
751 break;
752 ppp_recv_lock(ppp);
753 ppp->mrru = val;
754 ppp_recv_unlock(ppp);
755 err = 0;
756 break;
757#endif /* CONFIG_PPP_MULTILINK */
758
759 default:
760 err = -ENOTTY;
761 }
f3ff8a4d 762 unlock_kernel();
1da177e4
LT		 763 return err;
764}
765
766static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file,
767 unsigned int cmd, unsigned long arg)
768{
769 int unit, err = -EFAULT;
770 struct ppp *ppp;
771 struct channel *chan;
772 int __user *p = (int __user *)arg;
773
f3ff8a4d 774 lock_kernel();
1da177e4
LT		 775 switch (cmd) {
776 case PPPIOCNEWUNIT:
777 /* Create a new ppp unit */
778 if (get_user(unit, p))
779 break;
780 ppp = ppp_create_interface(unit, &err);
cd228d54 781 if (!ppp)
1da177e4
LT		 782 break;
783 file->private_data = &ppp->file;
784 ppp->owner = file;
785 err = -EFAULT;
786 if (put_user(ppp->file.index, p))
787 break;
788 err = 0;
789 break;
790
791 case PPPIOCATTACH:
792 /* Attach to an existing ppp unit */
793 if (get_user(unit, p))
794 break;
8ed965d6 795 mutex_lock(&all_ppp_mutex);
1da177e4
LT		 796 err = -ENXIO;
797 ppp = ppp_find_unit(unit);
cd228d54 798 if (ppp) {
1da177e4
LT		 799 atomic_inc(&ppp->file.refcnt);
800 file->private_data = &ppp->file;
801 err = 0;
802 }
8ed965d6 803 mutex_unlock(&all_ppp_mutex);
1da177e4
LT		 804 break;
805
806 case PPPIOCATTCHAN:
807 if (get_user(unit, p))
808 break;
809 spin_lock_bh(&all_channels_lock);
810 err = -ENXIO;
811 chan = ppp_find_channel(unit);
cd228d54 812 if (chan) {
1da177e4
LT		 813 atomic_inc(&chan->file.refcnt);
814 file->private_data = &chan->file;
815 err = 0;
816 }
817 spin_unlock_bh(&all_channels_lock);
818 break;
819
820 default:
821 err = -ENOTTY;
822 }
f3ff8a4d 823 unlock_kernel();
1da177e4
LT		 824 return err;
825}
826
d54b1fdb 827static const struct file_operations ppp_device_fops = {
1da177e4
LT		 828 .owner = THIS_MODULE,
829 .read = ppp_read,
830 .write = ppp_write,
831 .poll = ppp_poll,
f3ff8a4d 832 .unlocked_ioctl = ppp_ioctl,
1da177e4
LT		 833 .open = ppp_open,
834 .release = ppp_release
835};
836
837#define PPP_MAJOR 108
838
839/* Called at boot time if ppp is compiled into the kernel,
840 or at module load time (from init_module) if compiled as a module. */
841static int __init ppp_init(void)
842{
843 int err;
844
845 printk(KERN_INFO "PPP generic driver version " PPP_VERSION "\n");
846 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
847 if (!err) {
56b22935 848 ppp_class = class_create(THIS_MODULE, "ppp");
1da177e4
LT		 849 if (IS_ERR(ppp_class)) {
850 err = PTR_ERR(ppp_class);
851 goto out_chrdev;
852 }
6e05d6c4
GKH		 853 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL,
854 "ppp");
1da177e4
LT		 855 }
856
857out:
858 if (err)
859 printk(KERN_ERR "failed to register PPP device (%d)\n", err);
860 return err;
861
1da177e4
LT		 862out_chrdev:
863 unregister_chrdev(PPP_MAJOR, "ppp");
864 goto out;
865}
866
867/*
868 * Network interface unit routines.
869 */
870static int
871ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
872{
c8019bf3 873 struct ppp *ppp = netdev_priv(dev);
1da177e4
LT		 874 int npi, proto;
875 unsigned char *pp;
876
877 npi = ethertype_to_npindex(ntohs(skb->protocol));
878 if (npi < 0)
879 goto outf;
880
881 /* Drop, accept or reject the packet */
882 switch (ppp->npmode[npi]) {
883 case NPMODE_PASS:
884 break;
885 case NPMODE_QUEUE:
886 /* it would be nice to have a way to tell the network
887 system to queue this one up for later. */
888 goto outf;
889 case NPMODE_DROP:
890 case NPMODE_ERROR:
891 goto outf;
892 }
893
894 /* Put the 2-byte PPP protocol number on the front,
895 making sure there is room for the address and control fields. */
7b797d5b
HX		 896 if (skb_cow_head(skb, PPP_HDRLEN))
897 goto outf;
898
1da177e4
LT		 899 pp = skb_push(skb, 2);
900 proto = npindex_to_proto[npi];
901 pp[0] = proto >> 8;
902 pp[1] = proto;
903
904 netif_stop_queue(dev);
905 skb_queue_tail(&ppp->file.xq, skb);
906 ppp_xmit_process(ppp);
907 return 0;
908
909 outf:
910 kfree_skb(skb);
8c0469cd 911 ++ppp->dev->stats.tx_dropped;
1da177e4
LT		 912 return 0;
913}
914
1da177e4
LT		 915static int
916ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
917{
c8019bf3 918 struct ppp *ppp = netdev_priv(dev);
1da177e4
LT		 919 int err = -EFAULT;
920 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
921 struct ppp_stats stats;
922 struct ppp_comp_stats cstats;
923 char *vers;
924
925 switch (cmd) {
926 case SIOCGPPPSTATS:
927 ppp_get_stats(ppp, &stats);
928 if (copy_to_user(addr, &stats, sizeof(stats)))
929 break;
930 err = 0;
931 break;
932
933 case SIOCGPPPCSTATS:
934 memset(&cstats, 0, sizeof(cstats));
cd228d54 935 if (ppp->xc_state)
1da177e4 936 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
cd228d54 937 if (ppp->rc_state)
1da177e4
LT		 938 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
939 if (copy_to_user(addr, &cstats, sizeof(cstats)))
940 break;
941 err = 0;
942 break;
943
944 case SIOCGPPPVER:
945 vers = PPP_VERSION;
946 if (copy_to_user(addr, vers, strlen(vers) + 1))
947 break;
948 err = 0;
949 break;
950
951 default:
952 err = -EINVAL;
953 }
954
955 return err;
956}
957
52256cfc 958static const struct net_device_ops ppp_netdev_ops = {
00829823
SH		 959 .ndo_start_xmit = ppp_start_xmit,
960 .ndo_do_ioctl = ppp_net_ioctl,
52256cfc
SH		 961};
962
1da177e4
LT		 963static void ppp_setup(struct net_device *dev)
964{
52256cfc 965 dev->netdev_ops = &ppp_netdev_ops;
1da177e4
LT		 966 dev->hard_header_len = PPP_HDRLEN;
967 dev->mtu = PPP_MTU;
968 dev->addr_len = 0;
969 dev->tx_queue_len = 3;
970 dev->type = ARPHRD_PPP;
971 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
972}
973
974/*
975 * Transmit-side routines.
976 */
977
978/*
979 * Called to do any work queued up on the transmit side
980 * that can now be done.
981 */
982static void
983ppp_xmit_process(struct ppp *ppp)
984{
985 struct sk_buff *skb;
986
987 ppp_xmit_lock(ppp);
739840d5 988 if (!ppp->closing) {
1da177e4 989 ppp_push(ppp);
cd228d54
JP		 990 while (!ppp->xmit_pending
991 && (skb = skb_dequeue(&ppp->file.xq)))
1da177e4
LT		 992 ppp_send_frame(ppp, skb);
993 /* If there's no work left to do, tell the core net
994 code that we can accept some more. */
cd228d54 995 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1da177e4
LT		 996 netif_wake_queue(ppp->dev);
997 }
998 ppp_xmit_unlock(ppp);
999}
1000
b3f9b92a
MD		 1001static inline struct sk_buff *
1002pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1003{
1004 struct sk_buff *new_skb;
1005 int len;
1006 int new_skb_size = ppp->dev->mtu +
1007 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1008 int compressor_skb_size = ppp->dev->mtu +
1009 ppp->xcomp->comp_extra + PPP_HDRLEN;
1010 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1011 if (!new_skb) {
1012 if (net_ratelimit())
1013 printk(KERN_ERR "PPP: no memory (comp pkt)\n");
1014 return NULL;
1015 }
1016 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1017 skb_reserve(new_skb,
1018 ppp->dev->hard_header_len - PPP_HDRLEN);
1019
1020 /* compressor still expects A/C bytes in hdr */
1021 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1022 new_skb->data, skb->len + 2,
1023 compressor_skb_size);
1024 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1025 kfree_skb(skb);
1026 skb = new_skb;
1027 skb_put(skb, len);
1028 skb_pull(skb, 2); /* pull off A/C bytes */
1029 } else if (len == 0) {
1030 /* didn't compress, or CCP not up yet */
1031 kfree_skb(new_skb);
1032 new_skb = skb;
1033 } else {
1034 /*
1035 * (len < 0)
1036 * MPPE requires that we do not send unencrypted
1037 * frames. The compressor will return -1 if we
1038 * should drop the frame. We cannot simply test
1039 * the compress_proto because MPPE and MPPC share
1040 * the same number.
1041 */
1042 if (net_ratelimit())
1043 printk(KERN_ERR "ppp: compressor dropped pkt\n");
1044 kfree_skb(skb);
1045 kfree_skb(new_skb);
1046 new_skb = NULL;
1047 }
1048 return new_skb;
1049}
1050
1da177e4
LT		 1051/*
1052 * Compress and send a frame.
1053 * The caller should have locked the xmit path,
1054 * and xmit_pending should be 0.
1055 */
1056static void
1057ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1058{
1059 int proto = PPP_PROTO(skb);
1060 struct sk_buff *new_skb;
1061 int len;
1062 unsigned char *cp;
1063
1064 if (proto < 0x8000) {
1065#ifdef CONFIG_PPP_FILTER
1066 /* check if we should pass this packet */
1067 /* the filter instructions are constructed assuming
1068 a four-byte PPP header on each packet */
1069 *skb_push(skb, 2) = 1;
1070 if (ppp->pass_filter
1071 && sk_run_filter(skb, ppp->pass_filter,
1072 ppp->pass_len) == 0) {
1073 if (ppp->debug & 1)
1074 printk(KERN_DEBUG "PPP: outbound frame not passed\n");
1075 kfree_skb(skb);
1076 return;
1077 }
1078 /* if this packet passes the active filter, record the time */
1079 if (!(ppp->active_filter
1080 && sk_run_filter(skb, ppp->active_filter,
1081 ppp->active_len) == 0))
1082 ppp->last_xmit = jiffies;
1083 skb_pull(skb, 2);
1084#else
1085 /* for data packets, record the time */
1086 ppp->last_xmit = jiffies;
1087#endif /* CONFIG_PPP_FILTER */
1088 }
1089
8c0469cd
PZ		 1090 ++ppp->dev->stats.tx_packets;
1091 ppp->dev->stats.tx_bytes += skb->len - 2;
1da177e4
LT		 1092
1093 switch (proto) {
1094 case PPP_IP:
cd228d54 1095 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1da177e4
LT		 1096 break;
1097 /* try to do VJ TCP header compression */
1098 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1099 GFP_ATOMIC);
cd228d54 1100 if (!new_skb) {
1da177e4
LT		 1101 printk(KERN_ERR "PPP: no memory (VJ comp pkt)\n");
1102 goto drop;
1103 }
1104 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1105 cp = skb->data + 2;
1106 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1107 new_skb->data + 2, &cp,
1108 !(ppp->flags & SC_NO_TCP_CCID));
1109 if (cp == skb->data + 2) {
1110 /* didn't compress */
1111 kfree_skb(new_skb);
1112 } else {
1113 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1114 proto = PPP_VJC_COMP;
1115 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1116 } else {
1117 proto = PPP_VJC_UNCOMP;
1118 cp[0] = skb->data[2];
1119 }
1120 kfree_skb(skb);
1121 skb = new_skb;
1122 cp = skb_put(skb, len + 2);
1123 cp[0] = 0;
1124 cp[1] = proto;
1125 }
1126 break;
1127
1128 case PPP_CCP:
1129 /* peek at outbound CCP frames */
1130 ppp_ccp_peek(ppp, skb, 0);
1131 break;
1132 }
1133
1134 /* try to do packet compression */
cd228d54 1135 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state
1da177e4 1136 && proto != PPP_LCP && proto != PPP_CCP) {
b3f9b92a
MD		 1137 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1138 if (net_ratelimit())
1139 printk(KERN_ERR "ppp: compression required but down - pkt dropped.\n");
1da177e4
LT		 1140 goto drop;
1141 }
b3f9b92a
MD		 1142 skb = pad_compress_skb(ppp, skb);
1143 if (!skb)
1144 goto drop;
1da177e4
LT		 1145 }
1146
1147 /*
1148 * If we are waiting for traffic (demand dialling),
1149 * queue it up for pppd to receive.
1150 */
1151 if (ppp->flags & SC_LOOP_TRAFFIC) {
1152 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1153 goto drop;
1154 skb_queue_tail(&ppp->file.rq, skb);
1155 wake_up_interruptible(&ppp->file.rwait);
1156 return;
1157 }
1158
1159 ppp->xmit_pending = skb;
1160 ppp_push(ppp);
1161 return;
1162
1163 drop:
b3f9b92a
MD		 1164 if (skb)
1165 kfree_skb(skb);
8c0469cd 1166 ++ppp->dev->stats.tx_errors;
1da177e4
LT		 1167}
1168
1169/*
1170 * Try to send the frame in xmit_pending.
1171 * The caller should have the xmit path locked.
1172 */
1173static void
1174ppp_push(struct ppp *ppp)
1175{
1176 struct list_head *list;
1177 struct channel *pch;
1178 struct sk_buff *skb = ppp->xmit_pending;
1179
cd228d54 1180 if (!skb)
1da177e4
LT		 1181 return;
1182
1183 list = &ppp->channels;
1184 if (list_empty(list)) {
1185 /* nowhere to send the packet, just drop it */
1186 ppp->xmit_pending = NULL;
1187 kfree_skb(skb);
1188 return;
1189 }
1190
1191 if ((ppp->flags & SC_MULTILINK) == 0) {
1192 /* not doing multilink: send it down the first channel */
1193 list = list->next;
1194 pch = list_entry(list, struct channel, clist);
1195
1196 spin_lock_bh(&pch->downl);
1197 if (pch->chan) {
1198 if (pch->chan->ops->start_xmit(pch->chan, skb))
1199 ppp->xmit_pending = NULL;
1200 } else {
1201 /* channel got unregistered */
1202 kfree_skb(skb);
1203 ppp->xmit_pending = NULL;
1204 }
1205 spin_unlock_bh(&pch->downl);
1206 return;
1207 }
1208
1209#ifdef CONFIG_PPP_MULTILINK
1210 /* Multilink: fragment the packet over as many links
1211 as can take the packet at the moment. */
1212 if (!ppp_mp_explode(ppp, skb))
1213 return;
1214#endif /* CONFIG_PPP_MULTILINK */
1215
1216 ppp->xmit_pending = NULL;
1217 kfree_skb(skb);
1218}
1219
1220#ifdef CONFIG_PPP_MULTILINK
1221/*
1222 * Divide a packet to be transmitted into fragments and
1223 * send them out the individual links.
1224 */
1225static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1226{
516cd15f 1227 int len, fragsize;
1da177e4 1228 int i, bits, hdrlen, mtu;
516cd15f
PM		 1229 int flen;
1230 int navail, nfree;
1231 int nbigger;
1da177e4
LT		 1232 unsigned char *p, *q;
1233 struct list_head *list;
1234 struct channel *pch;
1235 struct sk_buff *frag;
1236 struct ppp_channel *chan;
1237
516cd15f
PM		 1238 nfree = 0; /* # channels which have no packet already queued */
1239 navail = 0; /* total # of usable channels (not deregistered) */
1da177e4 1240 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
516cd15f 1241 i = 0;
81616c5a 1242 list_for_each_entry(pch, &ppp->channels, clist) {
516cd15f
PM		 1243 navail += pch->avail = (pch->chan != NULL);
1244 if (pch->avail) {
b03efcfb
DM		 1245 if (skb_queue_empty(&pch->file.xq) ||
1246 !pch->had_frag) {
516cd15f
PM		 1247 pch->avail = 2;
1248 ++nfree;
1da177e4 1249 }
516cd15f
PM		 1250 if (!pch->had_frag && i < ppp->nxchan)
1251 ppp->nxchan = i;
1da177e4 1252 }
516cd15f 1253 ++i;
1da177e4 1254 }
516cd15f
PM		 1255
1256 /*
1257 * Don't start sending this packet unless at least half of
1258 * the channels are free. This gives much better TCP
1259 * performance if we have a lot of channels.
1260 */
1261 if (nfree == 0 || nfree < navail / 2)
1da177e4
LT		 1262 return 0; /* can't take now, leave it in xmit_pending */
1263
1264 /* Do protocol field compression (XXX this should be optional) */
1265 p = skb->data;
1266 len = skb->len;
1267 if (*p == 0) {
1268 ++p;
1269 --len;
1270 }
1271
516cd15f
PM		 1272 /*
1273 * Decide on fragment size.
1274 * We create a fragment for each free channel regardless of
1275 * how small they are (i.e. even 0 length) in order to minimize
1276 * the time that it will take to detect when a channel drops
1277 * a fragment.
1278 */
1da177e4 1279 fragsize = len;
516cd15f 1280 if (nfree > 1)
57cd5f75 1281 fragsize = DIV_ROUND_UP(fragsize, nfree);
516cd15f
PM		 1282 /* nbigger channels get fragsize bytes, the rest get fragsize-1,
1283 except if nbigger==0, then they all get fragsize. */
1284 nbigger = len % nfree;
1da177e4
LT		 1285
1286 /* skip to the channel after the one we last used
1287 and start at that one */
81616c5a 1288 list = &ppp->channels;
1da177e4
LT		 1289 for (i = 0; i < ppp->nxchan; ++i) {
1290 list = list->next;
1291 if (list == &ppp->channels) {
1292 i = 0;
1293 break;
1294 }
1295 }
1296
1297 /* create a fragment for each channel */
1298 bits = B;
516cd15f 1299 while (nfree > 0 || len > 0) {
1da177e4
LT		 1300 list = list->next;
1301 if (list == &ppp->channels) {
1302 i = 0;
1303 continue;
1304 }
1305 pch = list_entry(list, struct channel, clist);
1306 ++i;
1307 if (!pch->avail)
1308 continue;
1309
516cd15f
PM		 1310 /*
1311 * Skip this channel if it has a fragment pending already and
1312 * we haven't given a fragment to all of the free channels.
1313 */
1314 if (pch->avail == 1) {
1315 if (nfree > 0)
1316 continue;
1317 } else {
1318 --nfree;
1319 pch->avail = 1;
1320 }
1321
1da177e4
LT		 1322 /* check the channel's mtu and whether it is still attached. */
1323 spin_lock_bh(&pch->downl);
516cd15f
PM		 1324 if (pch->chan == NULL) {
1325 /* can't use this channel, it's being deregistered */
1da177e4
LT		 1326 spin_unlock_bh(&pch->downl);
1327 pch->avail = 0;
516cd15f 1328 if (--navail == 0)
1da177e4
LT		 1329 break;
1330 continue;
1331 }
1332
1333 /*
516cd15f
PM		 1334 * Create a fragment for this channel of
1335 * min(max(mtu+2-hdrlen, 4), fragsize, len) bytes.
1336 * If mtu+2-hdrlen < 4, that is a ridiculously small
1337 * MTU, so we use mtu = 2 + hdrlen.
1da177e4
LT		 1338 */
1339 if (fragsize > len)
1340 fragsize = len;
516cd15f
PM		 1341 flen = fragsize;
1342 mtu = pch->chan->mtu + 2 - hdrlen;
1343 if (mtu < 4)
1344 mtu = 4;
1345 if (flen > mtu)
1346 flen = mtu;
1347 if (flen == len && nfree == 0)
1348 bits |= E;
1349 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
cd228d54 1350 if (!frag)
516cd15f
PM		 1351 goto noskb;
1352 q = skb_put(frag, flen + hdrlen);
1353
1354 /* make the MP header */
1355 q[0] = PPP_MP >> 8;
1356 q[1] = PPP_MP;
1357 if (ppp->flags & SC_MP_XSHORTSEQ) {
1358 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1359 q[3] = ppp->nxseq;
1360 } else {
1361 q[2] = bits;
1362 q[3] = ppp->nxseq >> 16;
1363 q[4] = ppp->nxseq >> 8;
1364 q[5] = ppp->nxseq;
1da177e4 1365 }
516cd15f
PM		 1366
1367 /*
1368 * Copy the data in.
1369 * Unfortunately there is a bug in older versions of
1370 * the Linux PPP multilink reconstruction code where it
1371 * drops 0-length fragments. Therefore we make sure the
1372 * fragment has at least one byte of data. Any bytes
1373 * we add in this situation will end up as padding on the
1374 * end of the reconstructed packet.
1375 */
1376 if (flen == 0)
1377 *skb_put(frag, 1) = 0;
1378 else
1379 memcpy(q + hdrlen, p, flen);
1380
1381 /* try to send it down the channel */
1382 chan = pch->chan;
b03efcfb
DM		 1383 if (!skb_queue_empty(&pch->file.xq) ||
1384 !chan->ops->start_xmit(chan, frag))
516cd15f
PM		 1385 skb_queue_tail(&pch->file.xq, frag);
1386 pch->had_frag = 1;
1387 p += flen;
1388 len -= flen;
1389 ++ppp->nxseq;
1390 bits = 0;
1da177e4 1391 spin_unlock_bh(&pch->downl);
516cd15f
PM		 1392
1393 if (--nbigger == 0 && fragsize > 0)
1394 --fragsize;
1395 }
1da177e4
LT		 1396 ppp->nxchan = i;
1397
1398 return 1;
1399
1400 noskb:
1401 spin_unlock_bh(&pch->downl);
1402 if (ppp->debug & 1)
1403 printk(KERN_ERR "PPP: no memory (fragment)\n");
8c0469cd 1404 ++ppp->dev->stats.tx_errors;
1da177e4
LT		 1405 ++ppp->nxseq;
1406 return 1; /* abandon the frame */
1407}
1408#endif /* CONFIG_PPP_MULTILINK */
1409
1410/*
1411 * Try to send data out on a channel.
1412 */
1413static void
1414ppp_channel_push(struct channel *pch)
1415{
1416 struct sk_buff *skb;
1417 struct ppp *ppp;
1418
1419 spin_lock_bh(&pch->downl);
cd228d54 1420 if (pch->chan) {
b03efcfb 1421 while (!skb_queue_empty(&pch->file.xq)) {
1da177e4
LT		 1422 skb = skb_dequeue(&pch->file.xq);
1423 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1424 /* put the packet back and try again later */
1425 skb_queue_head(&pch->file.xq, skb);
1426 break;
1427 }
1428 }
1429 } else {
1430 /* channel got deregistered */
1431 skb_queue_purge(&pch->file.xq);
1432 }
1433 spin_unlock_bh(&pch->downl);
1434 /* see if there is anything from the attached unit to be sent */
b03efcfb 1435 if (skb_queue_empty(&pch->file.xq)) {
1da177e4
LT		 1436 read_lock_bh(&pch->upl);
1437 ppp = pch->ppp;
cd228d54 1438 if (ppp)
1da177e4
LT		 1439 ppp_xmit_process(ppp);
1440 read_unlock_bh(&pch->upl);
1441 }
1442}
1443
1444/*
1445 * Receive-side routines.
1446 */
1447
1448/* misuse a few fields of the skb for MP reconstruction */
1449#define sequence priority
1450#define BEbits cb[0]
1451
1452static inline void
1453ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1454{
1455 ppp_recv_lock(ppp);
739840d5 1456 if (!ppp->closing)
1da177e4
LT		 1457 ppp_receive_frame(ppp, skb, pch);
1458 else
1459 kfree_skb(skb);
1460 ppp_recv_unlock(ppp);
1461}
1462
1463void
1464ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1465{
1466 struct channel *pch = chan->ppp;
1467 int proto;
1468
cd228d54 1469 if (!pch || skb->len == 0) {
1da177e4
LT		 1470 kfree_skb(skb);
1471 return;
1472 }
516cd15f 1473
1da177e4
LT		 1474 proto = PPP_PROTO(skb);
1475 read_lock_bh(&pch->upl);
cd228d54 1476 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1da177e4
LT		 1477 /* put it on the channel queue */
1478 skb_queue_tail(&pch->file.rq, skb);
1479 /* drop old frames if queue too long */
1480 while (pch->file.rq.qlen > PPP_MAX_RQLEN
cd228d54 1481 && (skb = skb_dequeue(&pch->file.rq)))
1da177e4
LT		 1482 kfree_skb(skb);
1483 wake_up_interruptible(&pch->file.rwait);
1484 } else {
1485 ppp_do_recv(pch->ppp, skb, pch);
1486 }
1487 read_unlock_bh(&pch->upl);
1488}
1489
1490/* Put a 0-length skb in the receive queue as an error indication */
1491void
1492ppp_input_error(struct ppp_channel *chan, int code)
1493{
1494 struct channel *pch = chan->ppp;
1495 struct sk_buff *skb;
1496
cd228d54 1497 if (!pch)
1da177e4
LT		 1498 return;
1499
1500 read_lock_bh(&pch->upl);
cd228d54 1501 if (pch->ppp) {
1da177e4 1502 skb = alloc_skb(0, GFP_ATOMIC);
cd228d54 1503 if (skb) {
1da177e4
LT		 1504 skb->len = 0; /* probably unnecessary */
1505 skb->cb[0] = code;
1506 ppp_do_recv(pch->ppp, skb, pch);
1507 }
1508 }
1509 read_unlock_bh(&pch->upl);
1510}
1511
1512/*
1513 * We come in here to process a received frame.
1514 * The receive side of the ppp unit is locked.
1515 */
1516static void
1517ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1518{
2a38b775 1519 if (pskb_may_pull(skb, 2)) {
1da177e4
LT		 1520#ifdef CONFIG_PPP_MULTILINK
1521 /* XXX do channel-level decompression here */
1522 if (PPP_PROTO(skb) == PPP_MP)
1523 ppp_receive_mp_frame(ppp, skb, pch);
1524 else
1525#endif /* CONFIG_PPP_MULTILINK */
1526 ppp_receive_nonmp_frame(ppp, skb);
1527 return;
1528 }
1529
1530 if (skb->len > 0)
1531 /* note: a 0-length skb is used as an error indication */
8c0469cd 1532 ++ppp->dev->stats.rx_length_errors;
1da177e4
LT		 1533
1534 kfree_skb(skb);
1535 ppp_receive_error(ppp);
1536}
1537
1538static void
1539ppp_receive_error(struct ppp *ppp)
1540{
8c0469cd 1541 ++ppp->dev->stats.rx_errors;
cd228d54 1542 if (ppp->vj)
1da177e4
LT		 1543 slhc_toss(ppp->vj);
1544}
1545
1546static void
1547ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1548{
1549 struct sk_buff *ns;
1550 int proto, len, npi;
1551
1552 /*
1553 * Decompress the frame, if compressed.
1554 * Note that some decompressors need to see uncompressed frames
1555 * that come in as well as compressed frames.
1556 */
cd228d54 1557 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)
1da177e4
LT		 1558 && (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1559 skb = ppp_decompress_frame(ppp, skb);
1560
b3f9b92a
MD		 1561 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1562 goto err;
1563
1da177e4
LT		 1564 proto = PPP_PROTO(skb);
1565 switch (proto) {
1566 case PPP_VJC_COMP:
1567 /* decompress VJ compressed packets */
cd228d54 1568 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1da177e4
LT		 1569 goto err;
1570
2a38b775 1571 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1da177e4
LT		 1572 /* copy to a new sk_buff with more tailroom */
1573 ns = dev_alloc_skb(skb->len + 128);
cd228d54 1574 if (!ns) {
1da177e4
LT		 1575 printk(KERN_ERR"PPP: no memory (VJ decomp)\n");
1576 goto err;
1577 }
1578 skb_reserve(ns, 2);
1579 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1580 kfree_skb(skb);
1581 skb = ns;
1582 }
e3f749c4
HX		 1583 else
1584 skb->ip_summed = CHECKSUM_NONE;
1da177e4
LT		 1585
1586 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1587 if (len <= 0) {
1588 printk(KERN_DEBUG "PPP: VJ decompression error\n");
1589 goto err;
1590 }
1591 len += 2;
1592 if (len > skb->len)
1593 skb_put(skb, len - skb->len);
1594 else if (len < skb->len)
1595 skb_trim(skb, len);
1596 proto = PPP_IP;
1597 break;
1598
1599 case PPP_VJC_UNCOMP:
cd228d54 1600 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1da177e4 1601 goto err;
6aa20a22 1602
1da177e4
LT		 1603 /* Until we fix the decompressor need to make sure
1604 * data portion is linear.
1605 */
6aa20a22 1606 if (!pskb_may_pull(skb, skb->len))
1da177e4
LT		 1607 goto err;
1608
1609 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1610 printk(KERN_ERR "PPP: VJ uncompressed error\n");
1611 goto err;
1612 }
1613 proto = PPP_IP;
1614 break;
1615
1616 case PPP_CCP:
1617 ppp_ccp_peek(ppp, skb, 1);
1618 break;
1619 }
1620
8c0469cd
PZ		 1621 ++ppp->dev->stats.rx_packets;
1622 ppp->dev->stats.rx_bytes += skb->len - 2;
1da177e4
LT		 1623
1624 npi = proto_to_npindex(proto);
1625 if (npi < 0) {
1626 /* control or unknown frame - pass it to pppd */
1627 skb_queue_tail(&ppp->file.rq, skb);
1628 /* limit queue length by dropping old frames */
1629 while (ppp->file.rq.qlen > PPP_MAX_RQLEN
cd228d54 1630 && (skb = skb_dequeue(&ppp->file.rq)))
1da177e4
LT		 1631 kfree_skb(skb);
1632 /* wake up any process polling or blocking on read */
1633 wake_up_interruptible(&ppp->file.rwait);
1634
1635 } else {
1636 /* network protocol frame - give it to the kernel */
1637
1638#ifdef CONFIG_PPP_FILTER
1639 /* check if the packet passes the pass and active filters */
1640 /* the filter instructions are constructed assuming
1641 a four-byte PPP header on each packet */
2a38b775
HX		 1642 if (ppp->pass_filter || ppp->active_filter) {
1643 if (skb_cloned(skb) &&
1644 pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
1645 goto err;
1646
1647 *skb_push(skb, 2) = 0;
1648 if (ppp->pass_filter
1649 && sk_run_filter(skb, ppp->pass_filter,
1650 ppp->pass_len) == 0) {
1651 if (ppp->debug & 1)
1652 printk(KERN_DEBUG "PPP: inbound frame "
1653 "not passed\n");
1654 kfree_skb(skb);
1655 return;
1656 }
1657 if (!(ppp->active_filter
1658 && sk_run_filter(skb, ppp->active_filter,
1659 ppp->active_len) == 0))
1660 ppp->last_recv = jiffies;
1661 __skb_pull(skb, 2);
1662 } else
1da177e4 1663#endif /* CONFIG_PPP_FILTER */
2a38b775 1664 ppp->last_recv = jiffies;
1da177e4
LT		 1665
1666 if ((ppp->dev->flags & IFF_UP) == 0
1667 || ppp->npmode[npi] != NPMODE_PASS) {
1668 kfree_skb(skb);
1669 } else {
cbb042f9
HX		 1670 /* chop off protocol */
1671 skb_pull_rcsum(skb, 2);
1da177e4
LT		 1672 skb->dev = ppp->dev;
1673 skb->protocol = htons(npindex_to_ethertype[npi]);
459a98ed 1674 skb_reset_mac_header(skb);
1da177e4 1675 netif_rx(skb);
1da177e4
LT		 1676 }
1677 }
1678 return;
1679
1680 err:
1681 kfree_skb(skb);
1682 ppp_receive_error(ppp);
1683}
1684
1685static struct sk_buff *
1686ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1687{
1688 int proto = PPP_PROTO(skb);
1689 struct sk_buff *ns;
1690 int len;
1691
1692 /* Until we fix all the decompressor's need to make sure
1693 * data portion is linear.
1694 */
1695 if (!pskb_may_pull(skb, skb->len))
1696 goto err;
1697
1698 if (proto == PPP_COMP) {
4b2a8fb3
KS		 1699 int obuff_size;
1700
1701 switch(ppp->rcomp->compress_proto) {
1702 case CI_MPPE:
1703 obuff_size = ppp->mru + PPP_HDRLEN + 1;
1704 break;
1705 default:
1706 obuff_size = ppp->mru + PPP_HDRLEN;
1707 break;
1708 }
1709
1710 ns = dev_alloc_skb(obuff_size);
cd228d54 1711 if (!ns) {
1da177e4
LT		 1712 printk(KERN_ERR "ppp_decompress_frame: no memory\n");
1713 goto err;
1714 }
1715 /* the decompressor still expects the A/C bytes in the hdr */
1716 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
06c7af56 1717 skb->len + 2, ns->data, obuff_size);
1da177e4
LT		 1718 if (len < 0) {
1719 /* Pass the compressed frame to pppd as an
1720 error indication. */
1721 if (len == DECOMP_FATALERROR)
1722 ppp->rstate |= SC_DC_FERROR;
1723 kfree_skb(ns);
1724 goto err;
1725 }
1726
1727 kfree_skb(skb);
1728 skb = ns;
1729 skb_put(skb, len);
1730 skb_pull(skb, 2); /* pull off the A/C bytes */
1731
1732 } else {
1733 /* Uncompressed frame - pass to decompressor so it
1734 can update its dictionary if necessary. */
1735 if (ppp->rcomp->incomp)
1736 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1737 skb->len + 2);
1738 }
1739
1740 return skb;
1741
1742 err:
1743 ppp->rstate |= SC_DC_ERROR;
1744 ppp_receive_error(ppp);
1745 return skb;
1746}
1747
1748#ifdef CONFIG_PPP_MULTILINK
1749/*
1750 * Receive a multilink frame.
1751 * We put it on the reconstruction queue and then pull off
1752 * as many completed frames as we can.
1753 */
1754static void
1755ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1756{
1757 u32 mask, seq;
81616c5a 1758 struct channel *ch;
1da177e4
LT		 1759 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1760
2a38b775 1761 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
1da177e4
LT		 1762 goto err; /* no good, throw it away */
1763
1764 /* Decode sequence number and begin/end bits */
1765 if (ppp->flags & SC_MP_SHORTSEQ) {
1766 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1767 mask = 0xfff;
1768 } else {
1769 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1770 mask = 0xffffff;
1771 }
1772 skb->BEbits = skb->data[2];
1773 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
1774
1775 /*
1776 * Do protocol ID decompression on the first fragment of each packet.
1777 */
1778 if ((skb->BEbits & B) && (skb->data[0] & 1))
1779 *skb_push(skb, 1) = 0;
1780
1781 /*
1782 * Expand sequence number to 32 bits, making it as close
1783 * as possible to ppp->minseq.
1784 */
1785 seq |= ppp->minseq & ~mask;
1786 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
1787 seq += mask + 1;
1788 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
1789 seq -= mask + 1; /* should never happen */
1790 skb->sequence = seq;
1791 pch->lastseq = seq;
1792
1793 /*
1794 * If this packet comes before the next one we were expecting,
1795 * drop it.
1796 */
1797 if (seq_before(seq, ppp->nextseq)) {
1798 kfree_skb(skb);
8c0469cd 1799 ++ppp->dev->stats.rx_dropped;
1da177e4
LT		 1800 ppp_receive_error(ppp);
1801 return;
1802 }
1803
1804 /*
1805 * Reevaluate minseq, the minimum over all channels of the
1806 * last sequence number received on each channel. Because of
1807 * the increasing sequence number rule, we know that any fragment
1808 * before `minseq' which hasn't arrived is never going to arrive.
1809 * The list of channels can't change because we have the receive
1810 * side of the ppp unit locked.
1811 */
81616c5a 1812 list_for_each_entry(ch, &ppp->channels, clist) {
1da177e4
LT		 1813 if (seq_before(ch->lastseq, seq))
1814 seq = ch->lastseq;
1815 }
1816 if (seq_before(ppp->minseq, seq))
1817 ppp->minseq = seq;
1818
1819 /* Put the fragment on the reconstruction queue */
1820 ppp_mp_insert(ppp, skb);
1821
1822 /* If the queue is getting long, don't wait any longer for packets
1823 before the start of the queue. */
38ce7c73
DM		 1824 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
1825 struct sk_buff *skb = skb_peek(&ppp->mrq);
1826 if (seq_before(ppp->minseq, skb->sequence))
1827 ppp->minseq = skb->sequence;
1828 }
1da177e4
LT		 1829
1830 /* Pull completed packets off the queue and receive them. */
cd228d54 1831 while ((skb = ppp_mp_reconstruct(ppp)))
1da177e4
LT		 1832 ppp_receive_nonmp_frame(ppp, skb);
1833
1834 return;
1835
1836 err:
1837 kfree_skb(skb);
1838 ppp_receive_error(ppp);
1839}
1840
1841/*
1842 * Insert a fragment on the MP reconstruction queue.
1843 * The queue is ordered by increasing sequence number.
1844 */
1845static void
1846ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
1847{
1848 struct sk_buff *p;
1849 struct sk_buff_head *list = &ppp->mrq;
1850 u32 seq = skb->sequence;
1851
1852 /* N.B. we don't need to lock the list lock because we have the
1853 ppp unit receive-side lock. */
13c9821e 1854 skb_queue_walk(list, p) {
1da177e4
LT		 1855 if (seq_before(seq, p->sequence))
1856 break;
13c9821e 1857 }
43f59c89 1858 __skb_queue_before(list, p, skb);
1da177e4
LT		 1859}
1860
1861/*
1862 * Reconstruct a packet from the MP fragment queue.
1863 * We go through increasing sequence numbers until we find a
1864 * complete packet, or we get to the sequence number for a fragment
1865 * which hasn't arrived but might still do so.
1866 */
3c582b30 1867static struct sk_buff *
1da177e4
LT		 1868ppp_mp_reconstruct(struct ppp *ppp)
1869{
1870 u32 seq = ppp->nextseq;
1871 u32 minseq = ppp->minseq;
1872 struct sk_buff_head *list = &ppp->mrq;
1873 struct sk_buff *p, *next;
1874 struct sk_buff *head, *tail;
1875 struct sk_buff *skb = NULL;
1876 int lost = 0, len = 0;
1877
1878 if (ppp->mrru == 0) /* do nothing until mrru is set */
1879 return NULL;
1880 head = list->next;
1881 tail = NULL;
1882 for (p = head; p != (struct sk_buff *) list; p = next) {
1883 next = p->next;
1884 if (seq_before(p->sequence, seq)) {
1885 /* this can't happen, anyway ignore the skb */
1886 printk(KERN_ERR "ppp_mp_reconstruct bad seq %u < %u\n",
1887 p->sequence, seq);
1888 head = next;
1889 continue;
1890 }
1891 if (p->sequence != seq) {
1892 /* Fragment `seq' is missing. If it is after
1893 minseq, it might arrive later, so stop here. */
1894 if (seq_after(seq, minseq))
1895 break;
1896 /* Fragment `seq' is lost, keep going. */
1897 lost = 1;
1898 seq = seq_before(minseq, p->sequence)?
1899 minseq + 1: p->sequence;
1900 next = p;
1901 continue;
1902 }
1903
1904 /*
1905 * At this point we know that all the fragments from
1906 * ppp->nextseq to seq are either present or lost.
1907 * Also, there are no complete packets in the queue
1908 * that have no missing fragments and end before this
1909 * fragment.
1910 */
1911
1912 /* B bit set indicates this fragment starts a packet */
1913 if (p->BEbits & B) {
1914 head = p;
1915 lost = 0;
1916 len = 0;
1917 }
1918
1919 len += p->len;
1920
1921 /* Got a complete packet yet? */
1922 if (lost == 0 && (p->BEbits & E) && (head->BEbits & B)) {
1923 if (len > ppp->mrru + 2) {
8c0469cd 1924 ++ppp->dev->stats.rx_length_errors;
1da177e4
LT		 1925 printk(KERN_DEBUG "PPP: reconstructed packet"
1926 " is too long (%d)\n", len);
1927 } else if (p == head) {
1928 /* fragment is complete packet - reuse skb */
1929 tail = p;
1930 skb = skb_get(p);
1931 break;
1932 } else if ((skb = dev_alloc_skb(len)) == NULL) {
8c0469cd 1933 ++ppp->dev->stats.rx_missed_errors;
1da177e4
LT		 1934 printk(KERN_DEBUG "PPP: no memory for "
1935 "reconstructed packet");
1936 } else {
1937 tail = p;
1938 break;
1939 }
1940 ppp->nextseq = seq + 1;
1941 }
1942
1943 /*
1944 * If this is the ending fragment of a packet,
1945 * and we haven't found a complete valid packet yet,
1946 * we can discard up to and including this fragment.
1947 */
1948 if (p->BEbits & E)
1949 head = next;
1950
1951 ++seq;
1952 }
1953
1954 /* If we have a complete packet, copy it all into one skb. */
1955 if (tail != NULL) {
1956 /* If we have discarded any fragments,
1957 signal a receive error. */
1958 if (head->sequence != ppp->nextseq) {
1959 if (ppp->debug & 1)
1960 printk(KERN_DEBUG " missed pkts %u..%u\n",
1961 ppp->nextseq, head->sequence-1);
8c0469cd 1962 ++ppp->dev->stats.rx_dropped;
1da177e4
LT		 1963 ppp_receive_error(ppp);
1964 }
1965
1966 if (head != tail)
1967 /* copy to a single skb */
1968 for (p = head; p != tail->next; p = p->next)
1969 skb_copy_bits(p, 0, skb_put(skb, p->len), p->len);
1970 ppp->nextseq = tail->sequence + 1;
1971 head = tail->next;
1972 }
1973
1974 /* Discard all the skbuffs that we have copied the data out of
1975 or that we can't use. */
1976 while ((p = list->next) != head) {
1977 __skb_unlink(p, list);
1978 kfree_skb(p);
1979 }
1980
1981 return skb;
1982}
1983#endif /* CONFIG_PPP_MULTILINK */
1984
1985/*
1986 * Channel interface.
1987 */
1988
1989/*
1990 * Create a new, unattached ppp channel.
1991 */
1992int
1993ppp_register_channel(struct ppp_channel *chan)
1994{
1995 struct channel *pch;
1996
d4274b51 1997 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
cd228d54 1998 if (!pch)
1da177e4 1999 return -ENOMEM;
1da177e4
LT		 2000 pch->ppp = NULL;
2001 pch->chan = chan;
2002 chan->ppp = pch;
2003 init_ppp_file(&pch->file, CHANNEL);
2004 pch->file.hdrlen = chan->hdrlen;
2005#ifdef CONFIG_PPP_MULTILINK
2006 pch->lastseq = -1;
2007#endif /* CONFIG_PPP_MULTILINK */
2008 init_rwsem(&pch->chan_sem);
2009 spin_lock_init(&pch->downl);
2010 rwlock_init(&pch->upl);
2011 spin_lock_bh(&all_channels_lock);
2012 pch->file.index = ++last_channel_index;
2013 list_add(&pch->list, &new_channels);
2014 atomic_inc(&channel_count);
2015 spin_unlock_bh(&all_channels_lock);
2016 return 0;
2017}
2018
2019/*
2020 * Return the index of a channel.
2021 */
2022int ppp_channel_index(struct ppp_channel *chan)
2023{
2024 struct channel *pch = chan->ppp;
2025
cd228d54 2026 if (pch)
1da177e4
LT		 2027 return pch->file.index;
2028 return -1;
2029}
2030
2031/*
2032 * Return the PPP unit number to which a channel is connected.
2033 */
2034int ppp_unit_number(struct ppp_channel *chan)
2035{
2036 struct channel *pch = chan->ppp;
2037 int unit = -1;
2038
cd228d54 2039 if (pch) {
1da177e4 2040 read_lock_bh(&pch->upl);
cd228d54 2041 if (pch->ppp)
1da177e4
LT		 2042 unit = pch->ppp->file.index;
2043 read_unlock_bh(&pch->upl);
2044 }
2045 return unit;
2046}
2047
2048/*
2049 * Disconnect a channel from the generic layer.
2050 * This must be called in process context.
2051 */
2052void
2053ppp_unregister_channel(struct ppp_channel *chan)
2054{
2055 struct channel *pch = chan->ppp;
2056
cd228d54 2057 if (!pch)
1da177e4
LT		 2058 return; /* should never happen */
2059 chan->ppp = NULL;
2060
2061 /*
2062 * This ensures that we have returned from any calls into the
2063 * the channel's start_xmit or ioctl routine before we proceed.
2064 */
2065 down_write(&pch->chan_sem);
2066 spin_lock_bh(&pch->downl);
2067 pch->chan = NULL;
2068 spin_unlock_bh(&pch->downl);
2069 up_write(&pch->chan_sem);
2070 ppp_disconnect_channel(pch);
2071 spin_lock_bh(&all_channels_lock);
2072 list_del(&pch->list);
2073 spin_unlock_bh(&all_channels_lock);
2074 pch->file.dead = 1;
2075 wake_up_interruptible(&pch->file.rwait);
2076 if (atomic_dec_and_test(&pch->file.refcnt))
2077 ppp_destroy_channel(pch);
2078}
2079
2080/*
2081 * Callback from a channel when it can accept more to transmit.
2082 * This should be called at BH/softirq level, not interrupt level.
2083 */
2084void
2085ppp_output_wakeup(struct ppp_channel *chan)
2086{
2087 struct channel *pch = chan->ppp;
2088
cd228d54 2089 if (!pch)
1da177e4
LT		 2090 return;
2091 ppp_channel_push(pch);
2092}
2093
2094/*
2095 * Compression control.
2096 */
2097
2098/* Process the PPPIOCSCOMPRESS ioctl. */
2099static int
2100ppp_set_compress(struct ppp *ppp, unsigned long arg)
2101{
2102 int err;
2103 struct compressor *cp, *ocomp;
2104 struct ppp_option_data data;
2105 void *state, *ostate;
2106 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2107
2108 err = -EFAULT;
2109 if (copy_from_user(&data, (void __user *) arg, sizeof(data))
2110 || (data.length <= CCP_MAX_OPTION_LENGTH
2111 && copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2112 goto out;
2113 err = -EINVAL;
2114 if (data.length > CCP_MAX_OPTION_LENGTH
2115 || ccp_option[1] < 2 || ccp_option[1] > data.length)
2116 goto out;
2117
a65e5d78
JB		 2118 cp = try_then_request_module(
2119 find_compressor(ccp_option[0]),
2120 "ppp-compress-%d", ccp_option[0]);
cd228d54 2121 if (!cp)
1da177e4
LT		 2122 goto out;
2123
2124 err = -ENOBUFS;
2125 if (data.transmit) {
2126 state = cp->comp_alloc(ccp_option, data.length);
cd228d54 2127 if (state) {
1da177e4
LT		 2128 ppp_xmit_lock(ppp);
2129 ppp->xstate &= ~SC_COMP_RUN;
2130 ocomp = ppp->xcomp;
2131 ostate = ppp->xc_state;
2132 ppp->xcomp = cp;
2133 ppp->xc_state = state;
2134 ppp_xmit_unlock(ppp);
cd228d54 2135 if (ostate) {
1da177e4
LT		 2136 ocomp->comp_free(ostate);
2137 module_put(ocomp->owner);
2138 }
2139 err = 0;
2140 } else
2141 module_put(cp->owner);
2142
2143 } else {
2144 state = cp->decomp_alloc(ccp_option, data.length);
cd228d54 2145 if (state) {
1da177e4
LT		 2146 ppp_recv_lock(ppp);
2147 ppp->rstate &= ~SC_DECOMP_RUN;
2148 ocomp = ppp->rcomp;
2149 ostate = ppp->rc_state;
2150 ppp->rcomp = cp;
2151 ppp->rc_state = state;
2152 ppp_recv_unlock(ppp);
cd228d54 2153 if (ostate) {
1da177e4
LT		 2154 ocomp->decomp_free(ostate);
2155 module_put(ocomp->owner);
2156 }
2157 err = 0;
2158 } else
2159 module_put(cp->owner);
2160 }
2161
2162 out:
2163 return err;
2164}
2165
2166/*
2167 * Look at a CCP packet and update our state accordingly.
2168 * We assume the caller has the xmit or recv path locked.
2169 */
2170static void
2171ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2172{
2173 unsigned char *dp;
2174 int len;
2175
2176 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2177 return; /* no header */
2178 dp = skb->data + 2;
2179
2180 switch (CCP_CODE(dp)) {
2181 case CCP_CONFREQ:
2182
6aa20a22 2183 /* A ConfReq starts negotiation of compression
1da177e4
LT		 2184 * in one direction of transmission,
2185 * and hence brings it down...but which way?
2186 *
2187 * Remember:
2188 * A ConfReq indicates what the sender would like to receive
2189 */
2190 if(inbound)
2191 /* He is proposing what I should send */
2192 ppp->xstate &= ~SC_COMP_RUN;
6aa20a22 2193 else
1da177e4
LT		 2194 /* I am proposing to what he should send */
2195 ppp->rstate &= ~SC_DECOMP_RUN;
6aa20a22 2196
1da177e4 2197 break;
6aa20a22 2198
1da177e4
LT		 2199 case CCP_TERMREQ:
2200 case CCP_TERMACK:
2201 /*
6aa20a22 2202 * CCP is going down, both directions of transmission
1da177e4
LT		 2203 */
2204 ppp->rstate &= ~SC_DECOMP_RUN;
2205 ppp->xstate &= ~SC_COMP_RUN;
2206 break;
2207
2208 case CCP_CONFACK:
2209 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2210 break;
2211 len = CCP_LENGTH(dp);
2212 if (!pskb_may_pull(skb, len + 2))
2213 return; /* too short */
2214 dp += CCP_HDRLEN;
2215 len -= CCP_HDRLEN;
2216 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2217 break;
2218 if (inbound) {
2219 /* we will start receiving compressed packets */
cd228d54 2220 if (!ppp->rc_state)
1da177e4
LT		 2221 break;
2222 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2223 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2224 ppp->rstate |= SC_DECOMP_RUN;
2225 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2226 }
2227 } else {
2228 /* we will soon start sending compressed packets */
cd228d54 2229 if (!ppp->xc_state)
1da177e4
LT		 2230 break;
2231 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2232 ppp->file.index, 0, ppp->debug))
2233 ppp->xstate |= SC_COMP_RUN;
2234 }
2235 break;
2236
2237 case CCP_RESETACK:
2238 /* reset the [de]compressor */
2239 if ((ppp->flags & SC_CCP_UP) == 0)
2240 break;
2241 if (inbound) {
2242 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2243 ppp->rcomp->decomp_reset(ppp->rc_state);
2244 ppp->rstate &= ~SC_DC_ERROR;
2245 }
2246 } else {
2247 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2248 ppp->xcomp->comp_reset(ppp->xc_state);
2249 }
2250 break;
2251 }
2252}
2253
2254/* Free up compression resources. */
2255static void
2256ppp_ccp_closed(struct ppp *ppp)
2257{
2258 void *xstate, *rstate;
2259 struct compressor *xcomp, *rcomp;
2260
2261 ppp_lock(ppp);
2262 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2263 ppp->xstate = 0;
2264 xcomp = ppp->xcomp;
2265 xstate = ppp->xc_state;
2266 ppp->xc_state = NULL;
2267 ppp->rstate = 0;
2268 rcomp = ppp->rcomp;
2269 rstate = ppp->rc_state;
2270 ppp->rc_state = NULL;
2271 ppp_unlock(ppp);
2272
2273 if (xstate) {
2274 xcomp->comp_free(xstate);
2275 module_put(xcomp->owner);
2276 }
2277 if (rstate) {
2278 rcomp->decomp_free(rstate);
2279 module_put(rcomp->owner);
2280 }
2281}
2282
2283/* List of compressors. */
2284static LIST_HEAD(compressor_list);
2285static DEFINE_SPINLOCK(compressor_list_lock);
2286
2287struct compressor_entry {
2288 struct list_head list;
2289 struct compressor *comp;
2290};
2291
2292static struct compressor_entry *
2293find_comp_entry(int proto)
2294{
2295 struct compressor_entry *ce;
1da177e4 2296
81616c5a 2297 list_for_each_entry(ce, &compressor_list, list) {
1da177e4
LT		 2298 if (ce->comp->compress_proto == proto)
2299 return ce;
2300 }
2301 return NULL;
2302}
2303
2304/* Register a compressor */
2305int
2306ppp_register_compressor(struct compressor *cp)
2307{
2308 struct compressor_entry *ce;
2309 int ret;
2310 spin_lock(&compressor_list_lock);
2311 ret = -EEXIST;
cd228d54 2312 if (find_comp_entry(cp->compress_proto))
1da177e4
LT		 2313 goto out;
2314 ret = -ENOMEM;
2315 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
cd228d54 2316 if (!ce)
1da177e4
LT		 2317 goto out;
2318 ret = 0;
2319 ce->comp = cp;
2320 list_add(&ce->list, &compressor_list);
2321 out:
2322 spin_unlock(&compressor_list_lock);
2323 return ret;
2324}
2325
2326/* Unregister a compressor */
2327void
2328ppp_unregister_compressor(struct compressor *cp)
2329{
2330 struct compressor_entry *ce;
2331
2332 spin_lock(&compressor_list_lock);
2333 ce = find_comp_entry(cp->compress_proto);
cd228d54 2334 if (ce && ce->comp == cp) {
1da177e4
LT		 2335 list_del(&ce->list);
2336 kfree(ce);
2337 }
2338 spin_unlock(&compressor_list_lock);
2339}
2340
2341/* Find a compressor. */
2342static struct compressor *
2343find_compressor(int type)
2344{
2345 struct compressor_entry *ce;
2346 struct compressor *cp = NULL;
2347
2348 spin_lock(&compressor_list_lock);
2349 ce = find_comp_entry(type);
cd228d54 2350 if (ce) {
1da177e4
LT		 2351 cp = ce->comp;
2352 if (!try_module_get(cp->owner))
2353 cp = NULL;
2354 }
2355 spin_unlock(&compressor_list_lock);
2356 return cp;
2357}
2358
2359/*
2360 * Miscelleneous stuff.
2361 */
2362
2363static void
2364ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2365{
2366 struct slcompress *vj = ppp->vj;
2367
2368 memset(st, 0, sizeof(*st));
8c0469cd
PZ		 2369 st->p.ppp_ipackets = ppp->dev->stats.rx_packets;
2370 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2371 st->p.ppp_ibytes = ppp->dev->stats.rx_bytes;
2372 st->p.ppp_opackets = ppp->dev->stats.tx_packets;
2373 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2374 st->p.ppp_obytes = ppp->dev->stats.tx_bytes;
cd228d54 2375 if (!vj)
1da177e4
LT		 2376 return;
2377 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2378 st->vj.vjs_compressed = vj->sls_o_compressed;
2379 st->vj.vjs_searches = vj->sls_o_searches;
2380 st->vj.vjs_misses = vj->sls_o_misses;
2381 st->vj.vjs_errorin = vj->sls_i_error;
2382 st->vj.vjs_tossed = vj->sls_i_tossed;
2383 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2384 st->vj.vjs_compressedin = vj->sls_i_compressed;
2385}
2386
2387/*
2388 * Stuff for handling the lists of ppp units and channels
2389 * and for initialization.
2390 */
2391
2392/*
2393 * Create a new ppp interface unit. Fails if it can't allocate memory
2394 * or if there is already a unit with the requested number.
2395 * unit == -1 means allocate a new number.
2396 */
2397static struct ppp *
2398ppp_create_interface(int unit, int *retp)
2399{
2400 struct ppp *ppp;
2401 struct net_device *dev = NULL;
2402 int ret = -ENOMEM;
2403 int i;
2404
c8019bf3 2405 dev = alloc_netdev(sizeof(struct ppp), "", ppp_setup);
1da177e4
LT		 2406 if (!dev)
2407 goto out1;
1da177e4 2408
c8019bf3
WC		 2409 ppp = netdev_priv(dev);
2410 ppp->dev = dev;
1da177e4
LT		 2411 ppp->mru = PPP_MRU;
2412 init_ppp_file(&ppp->file, INTERFACE);
2413 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2414 for (i = 0; i < NUM_NP; ++i)
2415 ppp->npmode[i] = NPMODE_PASS;
2416 INIT_LIST_HEAD(&ppp->channels);
2417 spin_lock_init(&ppp->rlock);
2418 spin_lock_init(&ppp->wlock);
2419#ifdef CONFIG_PPP_MULTILINK
2420 ppp->minseq = -1;
2421 skb_queue_head_init(&ppp->mrq);
2422#endif /* CONFIG_PPP_MULTILINK */
1da177e4 2423
1da177e4 2424 ret = -EEXIST;
8ed965d6 2425 mutex_lock(&all_ppp_mutex);
7a95d267
CG		 2426
2427 if (unit < 0) {
2428 unit = unit_get(&ppp_units_idr, ppp);
2429 if (unit < 0) {
2430 *retp = unit;
2431 goto out2;
2432 }
2433 } else {
2434 if (unit_find(&ppp_units_idr, unit))
2435 goto out2; /* unit already exists */
85997576
CG		 2436 /*
2437 * if caller need a specified unit number
2438 * lets try to satisfy him, otherwise --
2439 * he should better ask us for new unit number
2440 *
2441 * NOTE: yes I know that returning EEXIST it's not
2442 * fair but at least pppd will ask us to allocate
2443 * new unit in this case so user is happy :)
2444 */
2445 unit = unit_set(&ppp_units_idr, ppp, unit);
2446 if (unit < 0)
7a95d267 2447 goto out2;
7a95d267 2448 }
1da177e4
LT		 2449
2450 /* Initialize the new ppp unit */
2451 ppp->file.index = unit;
2452 sprintf(dev->name, "ppp%d", unit);
2453
2454 ret = register_netdev(dev);
2455 if (ret != 0) {
7a95d267 2456 unit_put(&ppp_units_idr, unit);
1da177e4
LT		 2457 printk(KERN_ERR "PPP: couldn't register device %s (%d)\n",
2458 dev->name, ret);
2459 goto out2;
2460 }
2461
2462 atomic_inc(&ppp_unit_count);
8ed965d6 2463 mutex_unlock(&all_ppp_mutex);
7a95d267 2464
1da177e4
LT		 2465 *retp = 0;
2466 return ppp;
2467
2468out2:
8ed965d6 2469 mutex_unlock(&all_ppp_mutex);
1da177e4
LT		 2470 free_netdev(dev);
2471out1:
1da177e4
LT		 2472 *retp = ret;
2473 return NULL;
2474}
2475
2476/*
2477 * Initialize a ppp_file structure.
2478 */
2479static void
2480init_ppp_file(struct ppp_file *pf, int kind)
2481{
2482 pf->kind = kind;
2483 skb_queue_head_init(&pf->xq);
2484 skb_queue_head_init(&pf->rq);
2485 atomic_set(&pf->refcnt, 1);
2486 init_waitqueue_head(&pf->rwait);
2487}
2488
2489/*
2490 * Take down a ppp interface unit - called when the owning file
2491 * (the one that created the unit) is closed or detached.
2492 */
2493static void ppp_shutdown_interface(struct ppp *ppp)
2494{
8ed965d6 2495 mutex_lock(&all_ppp_mutex);
1da177e4 2496 /* This will call dev_close() for us. */
739840d5
JC		 2497 ppp_lock(ppp);
2498 if (!ppp->closing) {
2499 ppp->closing = 1;
2500 ppp_unlock(ppp);
2501 unregister_netdev(ppp->dev);
2502 } else
2503 ppp_unlock(ppp);
2504
7a95d267 2505 unit_put(&ppp_units_idr, ppp->file.index);
1da177e4
LT		 2506 ppp->file.dead = 1;
2507 ppp->owner = NULL;
2508 wake_up_interruptible(&ppp->file.rwait);
8ed965d6 2509 mutex_unlock(&all_ppp_mutex);
1da177e4
LT		 2510}
2511
2512/*
2513 * Free the memory used by a ppp unit. This is only called once
2514 * there are no channels connected to the unit and no file structs
2515 * that reference the unit.
2516 */
2517static void ppp_destroy_interface(struct ppp *ppp)
2518{
2519 atomic_dec(&ppp_unit_count);
2520
2521 if (!ppp->file.dead || ppp->n_channels) {
2522 /* "can't happen" */
2523 printk(KERN_ERR "ppp: destroying ppp struct %p but dead=%d "
2524 "n_channels=%d !\n", ppp, ppp->file.dead,
2525 ppp->n_channels);
2526 return;
2527 }
2528
2529 ppp_ccp_closed(ppp);
2530 if (ppp->vj) {
2531 slhc_free(ppp->vj);
2532 ppp->vj = NULL;
2533 }
2534 skb_queue_purge(&ppp->file.xq);
2535 skb_queue_purge(&ppp->file.rq);
2536#ifdef CONFIG_PPP_MULTILINK
2537 skb_queue_purge(&ppp->mrq);
2538#endif /* CONFIG_PPP_MULTILINK */
2539#ifdef CONFIG_PPP_FILTER
96edf83c
JJ		 2540 kfree(ppp->pass_filter);
2541 ppp->pass_filter = NULL;
2542 kfree(ppp->active_filter);
2543 ppp->active_filter = NULL;
1da177e4
LT		 2544#endif /* CONFIG_PPP_FILTER */
2545
165de5b7
L		 2546 if (ppp->xmit_pending)
2547 kfree_skb(ppp->xmit_pending);
2548
739840d5 2549 free_netdev(ppp->dev);
1da177e4
LT		 2550}
2551
2552/*
2553 * Locate an existing ppp unit.
8ed965d6 2554 * The caller should have locked the all_ppp_mutex.
1da177e4
LT		 2555 */
2556static struct ppp *
2557ppp_find_unit(int unit)
2558{
7a95d267 2559 return unit_find(&ppp_units_idr, unit);
1da177e4
LT		 2560}
2561
2562/*
2563 * Locate an existing ppp channel.
2564 * The caller should have locked the all_channels_lock.
2565 * First we look in the new_channels list, then in the
2566 * all_channels list. If found in the new_channels list,
2567 * we move it to the all_channels list. This is for speed
2568 * when we have a lot of channels in use.
2569 */
2570static struct channel *
2571ppp_find_channel(int unit)
2572{
2573 struct channel *pch;
1da177e4 2574
81616c5a 2575 list_for_each_entry(pch, &new_channels, list) {
1da177e4 2576 if (pch->file.index == unit) {
179e0917 2577 list_move(&pch->list, &all_channels);
1da177e4
LT		 2578 return pch;
2579 }
2580 }
81616c5a 2581 list_for_each_entry(pch, &all_channels, list) {
1da177e4
LT		 2582 if (pch->file.index == unit)
2583 return pch;
2584 }
2585 return NULL;
2586}
2587
2588/*
2589 * Connect a PPP channel to a PPP interface unit.
2590 */
2591static int
2592ppp_connect_channel(struct channel *pch, int unit)
2593{
2594 struct ppp *ppp;
2595 int ret = -ENXIO;
2596 int hdrlen;
2597
8ed965d6 2598 mutex_lock(&all_ppp_mutex);
1da177e4 2599 ppp = ppp_find_unit(unit);
cd228d54 2600 if (!ppp)
1da177e4
LT		 2601 goto out;
2602 write_lock_bh(&pch->upl);
2603 ret = -EINVAL;
cd228d54 2604 if (pch->ppp)
1da177e4
LT		 2605 goto outl;
2606
2607 ppp_lock(ppp);
2608 if (pch->file.hdrlen > ppp->file.hdrlen)
2609 ppp->file.hdrlen = pch->file.hdrlen;
2610 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
739840d5 2611 if (hdrlen > ppp->dev->hard_header_len)
1da177e4
LT		 2612 ppp->dev->hard_header_len = hdrlen;
2613 list_add_tail(&pch->clist, &ppp->channels);
2614 ++ppp->n_channels;
2615 pch->ppp = ppp;
2616 atomic_inc(&ppp->file.refcnt);
2617 ppp_unlock(ppp);
2618 ret = 0;
2619
2620 outl:
2621 write_unlock_bh(&pch->upl);
2622 out:
8ed965d6 2623 mutex_unlock(&all_ppp_mutex);
1da177e4
LT		 2624 return ret;
2625}
2626
2627/*
2628 * Disconnect a channel from its ppp unit.
2629 */
2630static int
2631ppp_disconnect_channel(struct channel *pch)
2632{
2633 struct ppp *ppp;
2634 int err = -EINVAL;
2635
2636 write_lock_bh(&pch->upl);
2637 ppp = pch->ppp;
2638 pch->ppp = NULL;
2639 write_unlock_bh(&pch->upl);
cd228d54 2640 if (ppp) {
1da177e4
LT		 2641 /* remove it from the ppp unit's list */
2642 ppp_lock(ppp);
2643 list_del(&pch->clist);
2644 if (--ppp->n_channels == 0)
2645 wake_up_interruptible(&ppp->file.rwait);
2646 ppp_unlock(ppp);
2647 if (atomic_dec_and_test(&ppp->file.refcnt))
2648 ppp_destroy_interface(ppp);
2649 err = 0;
2650 }
2651 return err;
2652}
2653
2654/*
2655 * Free up the resources used by a ppp channel.
2656 */
2657static void ppp_destroy_channel(struct channel *pch)
2658{
2659 atomic_dec(&channel_count);
2660
2661 if (!pch->file.dead) {
2662 /* "can't happen" */
2663 printk(KERN_ERR "ppp: destroying undead channel %p !\n",
2664 pch);
2665 return;
2666 }
2667 skb_queue_purge(&pch->file.xq);
2668 skb_queue_purge(&pch->file.rq);
2669 kfree(pch);
2670}
2671
2672static void __exit ppp_cleanup(void)
2673{
2674 /* should never happen */
2675 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2676 printk(KERN_ERR "PPP: removing module but units remain!\n");
68fc4fab 2677 unregister_chrdev(PPP_MAJOR, "ppp");
9a6a2a5e 2678 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
56b22935 2679 class_destroy(ppp_class);
7a95d267 2680 idr_destroy(&ppp_units_idr);
1da177e4
LT		 2681}
2682
2683/*
7a95d267
CG		 2684 * Units handling. Caller must protect concurrent access
2685 * by holding all_ppp_mutex
1da177e4 2686 */
7a95d267 2687
85997576
CG		 2688/* associate pointer with specified number */
2689static int unit_set(struct idr *p, void *ptr, int n)
2690{
2691 int unit, err;
2692
2693again:
2694 if (!idr_pre_get(p, GFP_KERNEL)) {
2695 printk(KERN_ERR "PPP: No free memory for idr\n");
2696 return -ENOMEM;
2697 }
2698
2699 err = idr_get_new_above(p, ptr, n, &unit);
2700 if (err == -EAGAIN)
2701 goto again;
2702
2703 if (unit != n) {
2704 idr_remove(p, unit);
2705 return -EINVAL;
2706 }
2707
2708 return unit;
2709}
2710
7a95d267
CG		 2711/* get new free unit number and associate pointer with it */
2712static int unit_get(struct idr *p, void *ptr)
1da177e4 2713{
7a95d267 2714 int unit, err;
1da177e4 2715
7a95d267 2716again:
85997576
CG		 2717 if (!idr_pre_get(p, GFP_KERNEL)) {
2718 printk(KERN_ERR "PPP: No free memory for idr\n");
7a95d267 2719 return -ENOMEM;
1da177e4 2720 }
1da177e4 2721
7a95d267
CG		 2722 err = idr_get_new_above(p, ptr, 0, &unit);
2723 if (err == -EAGAIN)
2724 goto again;
1da177e4 2725
7a95d267 2726 return unit;
1da177e4
LT		 2727}
2728
7a95d267
CG		 2729/* put unit number back to a pool */
2730static void unit_put(struct idr *p, int n)
1da177e4 2731{
7a95d267 2732 idr_remove(p, n);
1da177e4
LT		 2733}
2734
7a95d267
CG		 2735/* get pointer associated with the number */
2736static void *unit_find(struct idr *p, int n)
1da177e4 2737{
7a95d267 2738 return idr_find(p, n);
1da177e4
LT		 2739}
2740
2741/* Module/initialization stuff */
2742
2743module_init(ppp_init);
2744module_exit(ppp_cleanup);
2745
2746EXPORT_SYMBOL(ppp_register_channel);
2747EXPORT_SYMBOL(ppp_unregister_channel);
2748EXPORT_SYMBOL(ppp_channel_index);
2749EXPORT_SYMBOL(ppp_unit_number);
2750EXPORT_SYMBOL(ppp_input);
2751EXPORT_SYMBOL(ppp_input_error);
2752EXPORT_SYMBOL(ppp_output_wakeup);
2753EXPORT_SYMBOL(ppp_register_compressor);
2754EXPORT_SYMBOL(ppp_unregister_compressor);
2755MODULE_LICENSE("GPL");
2756MODULE_ALIAS_CHARDEV_MAJOR(PPP_MAJOR);
2757MODULE_ALIAS("/dev/ppp");
Clone of davem's net-next-2.6 tree