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kmemtrace: SLOB hooks.
[linux-2.6/kmemtrace.git] / drivers / net / ppp_generic.c
blob1f4ca2b54a73370213d1ce162c5c048e00bfc732
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
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>
30 #include <linux/netdevice.h>
31 #include <linux/poll.h>
32 #include <linux/ppp_defs.h>
33 #include <linux/filter.h>
34 #include <linux/if_ppp.h>
35 #include <linux/ppp_channel.h>
36 #include <linux/ppp-comp.h>
37 #include <linux/skbuff.h>
38 #include <linux/rtnetlink.h>
39 #include <linux/if_arp.h>
40 #include <linux/ip.h>
41 #include <linux/tcp.h>
42 #include <linux/spinlock.h>
43 #include <linux/rwsem.h>
44 #include <linux/stddef.h>
45 #include <linux/device.h>
46 #include <linux/mutex.h>
47 #include <net/slhc_vj.h>
48 #include <asm/atomic.h>
49
50 #define PPP_VERSION "2.4.2"
51
52 /*
53 * Network protocols we support.
54 */
55 #define NP_IP 0 /* Internet Protocol V4 */
56 #define NP_IPV6 1 /* Internet Protocol V6 */
57 #define NP_IPX 2 /* IPX protocol */
58 #define NP_AT 3 /* Appletalk protocol */
59 #define NP_MPLS_UC 4 /* MPLS unicast */
60 #define NP_MPLS_MC 5 /* MPLS multicast */
61 #define NUM_NP 6 /* Number of NPs. */
62
63 #define MPHDRLEN 6 /* multilink protocol header length */
64 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */
65 #define MIN_FRAG_SIZE 64
66
67 /*
68 * An instance of /dev/ppp can be associated with either a ppp
69 * interface unit or a ppp channel. In both cases, file->private_data
70 * points to one of these.
71 */
72 struct ppp_file {
73 enum {
74 INTERFACE=1, CHANNEL
75 } kind;
76 struct sk_buff_head xq; /* pppd transmit queue */
77 struct sk_buff_head rq; /* receive queue for pppd */
78 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */
79 atomic_t refcnt; /* # refs (incl /dev/ppp attached) */
80 int hdrlen; /* space to leave for headers */
81 int index; /* interface unit / channel number */
82 int dead; /* unit/channel has been shut down */
83 };
84
85 #define PF_TO_X(pf, X) container_of(pf, X, file)
86
87 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
88 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
89
90 /*
91 * Data structure describing one ppp unit.
92 * A ppp unit corresponds to a ppp network interface device
93 * and represents a multilink bundle.
94 * It can have 0 or more ppp channels connected to it.
95 */
96 struct ppp {
97 struct ppp_file file; /* stuff for read/write/poll 0 */
98 struct file *owner; /* file that owns this unit 48 */
99 struct list_head channels; /* list of attached channels 4c */
100 int n_channels; /* how many channels are attached 54 */
101 spinlock_t rlock; /* lock for receive side 58 */
102 spinlock_t wlock; /* lock for transmit side 5c */
103 int mru; /* max receive unit 60 */
104 unsigned int flags; /* control bits 64 */
105 unsigned int xstate; /* transmit state bits 68 */
106 unsigned int rstate; /* receive state bits 6c */
107 int debug; /* debug flags 70 */
108 struct slcompress *vj; /* state for VJ header compression */
109 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
110 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
111 struct compressor *xcomp; /* transmit packet compressor 8c */
112 void *xc_state; /* its internal state 90 */
113 struct compressor *rcomp; /* receive decompressor 94 */
114 void *rc_state; /* its internal state 98 */
115 unsigned long last_xmit; /* jiffies when last pkt sent 9c */
116 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
117 struct net_device *dev; /* network interface device a4 */
118 #ifdef CONFIG_PPP_MULTILINK
119 int nxchan; /* next channel to send something on */
120 u32 nxseq; /* next sequence number to send */
121 int mrru; /* MP: max reconst. receive unit */
122 u32 nextseq; /* MP: seq no of next packet */
123 u32 minseq; /* MP: min of most recent seqnos */
124 struct sk_buff_head mrq; /* MP: receive reconstruction queue */
125 #endif /* CONFIG_PPP_MULTILINK */
126 #ifdef CONFIG_PPP_FILTER
127 struct sock_filter *pass_filter; /* filter for packets to pass */
128 struct sock_filter *active_filter;/* filter for pkts to reset idle */
129 unsigned pass_len, active_len;
130 #endif /* CONFIG_PPP_FILTER */
131 };
132
133 /*
134 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
135 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
136 * SC_MUST_COMP
137 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
138 * Bits in xstate: SC_COMP_RUN
139 */
140 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
141 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
142 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
143
144 /*
145 * Private data structure for each channel.
146 * This includes the data structure used for multilink.
147 */
148 struct channel {
149 struct ppp_file file; /* stuff for read/write/poll */
150 struct list_head list; /* link in all/new_channels list */
151 struct ppp_channel *chan; /* public channel data structure */
152 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
153 spinlock_t downl; /* protects `chan', file.xq dequeue */
154 struct ppp *ppp; /* ppp unit we're connected to */
155 struct list_head clist; /* link in list of channels per unit */
156 rwlock_t upl; /* protects `ppp' */
157 #ifdef CONFIG_PPP_MULTILINK
158 u8 avail; /* flag used in multilink stuff */
159 u8 had_frag; /* >= 1 fragments have been sent */
160 u32 lastseq; /* MP: last sequence # received */
161 #endif /* CONFIG_PPP_MULTILINK */
162 };
163
164 /*
165 * SMP locking issues:
166 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
167 * list and the ppp.n_channels field, you need to take both locks
168 * before you modify them.
169 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
170 * channel.downl.
171 */
172
173 /*
174 * A cardmap represents a mapping from unsigned integers to pointers,
175 * and provides a fast "find lowest unused number" operation.
176 * It uses a broad (32-way) tree with a bitmap at each level.
177 * It is designed to be space-efficient for small numbers of entries
178 * and time-efficient for large numbers of entries.
179 */
180 #define CARDMAP_ORDER 5
181 #define CARDMAP_WIDTH (1U << CARDMAP_ORDER)
182 #define CARDMAP_MASK (CARDMAP_WIDTH - 1)
183
184 struct cardmap {
185 int shift;
186 unsigned long inuse;
187 struct cardmap *parent;
188 void *ptr[CARDMAP_WIDTH];
189 };
190 static void *cardmap_get(struct cardmap *map, unsigned int nr);
191 static int cardmap_set(struct cardmap **map, unsigned int nr, void *ptr);
192 static unsigned int cardmap_find_first_free(struct cardmap *map);
193 static void cardmap_destroy(struct cardmap **map);
194
195 /*
196 * all_ppp_mutex protects the all_ppp_units mapping.
197 * It also ensures that finding a ppp unit in the all_ppp_units map
198 * and updating its file.refcnt field is atomic.
199 */
200 static DEFINE_MUTEX(all_ppp_mutex);
201 static struct cardmap *all_ppp_units;
202 static atomic_t ppp_unit_count = ATOMIC_INIT(0);
203
204 /*
205 * all_channels_lock protects all_channels and last_channel_index,
206 * and the atomicity of find a channel and updating its file.refcnt
207 * field.
208 */
209 static DEFINE_SPINLOCK(all_channels_lock);
210 static LIST_HEAD(all_channels);
211 static LIST_HEAD(new_channels);
212 static int last_channel_index;
213 static atomic_t channel_count = ATOMIC_INIT(0);
214
215 /* Get the PPP protocol number from a skb */
216 #define PPP_PROTO(skb) (((skb)->data[0] << 8) + (skb)->data[1])
217
218 /* We limit the length of ppp->file.rq to this (arbitrary) value */
219 #define PPP_MAX_RQLEN 32
220
221 /*
222 * Maximum number of multilink fragments queued up.
223 * This has to be large enough to cope with the maximum latency of
224 * the slowest channel relative to the others. Strictly it should
225 * depend on the number of channels and their characteristics.
226 */
227 #define PPP_MP_MAX_QLEN 128
228
229 /* Multilink header bits. */
230 #define B 0x80 /* this fragment begins a packet */
231 #define E 0x40 /* this fragment ends a packet */
232
233 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */
234 #define seq_before(a, b) ((s32)((a) - (b)) < 0)
235 #define seq_after(a, b) ((s32)((a) - (b)) > 0)
236
237 /* Prototypes. */
238 static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file,
239 unsigned int cmd, unsigned long arg);
240 static void ppp_xmit_process(struct ppp *ppp);
241 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
242 static void ppp_push(struct ppp *ppp);
243 static void ppp_channel_push(struct channel *pch);
244 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
245 struct channel *pch);
246 static void ppp_receive_error(struct ppp *ppp);
247 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
248 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
249 struct sk_buff *skb);
250 #ifdef CONFIG_PPP_MULTILINK
251 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
252 struct channel *pch);
253 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
254 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
255 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
256 #endif /* CONFIG_PPP_MULTILINK */
257 static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
258 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
259 static void ppp_ccp_closed(struct ppp *ppp);
260 static struct compressor *find_compressor(int type);
261 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
262 static struct ppp *ppp_create_interface(int unit, int *retp);
263 static void init_ppp_file(struct ppp_file *pf, int kind);
264 static void ppp_shutdown_interface(struct ppp *ppp);
265 static void ppp_destroy_interface(struct ppp *ppp);
266 static struct ppp *ppp_find_unit(int unit);
267 static struct channel *ppp_find_channel(int unit);
268 static int ppp_connect_channel(struct channel *pch, int unit);
269 static int ppp_disconnect_channel(struct channel *pch);
270 static void ppp_destroy_channel(struct channel *pch);
271
272 static struct class *ppp_class;
273
274 /* Translates a PPP protocol number to a NP index (NP == network protocol) */
275 static inline int proto_to_npindex(int proto)
276 {
277 switch (proto) {
278 case PPP_IP:
279 return NP_IP;
280 case PPP_IPV6:
281 return NP_IPV6;
282 case PPP_IPX:
283 return NP_IPX;
284 case PPP_AT:
285 return NP_AT;
286 case PPP_MPLS_UC:
287 return NP_MPLS_UC;
288 case PPP_MPLS_MC:
289 return NP_MPLS_MC;
290 }
291 return -EINVAL;
292 }
293
294 /* Translates an NP index into a PPP protocol number */
295 static const int npindex_to_proto[NUM_NP] = {
296 PPP_IP,
297 PPP_IPV6,
298 PPP_IPX,
299 PPP_AT,
300 PPP_MPLS_UC,
301 PPP_MPLS_MC,
302 };
303
304 /* Translates an ethertype into an NP index */
305 static inline int ethertype_to_npindex(int ethertype)
306 {
307 switch (ethertype) {
308 case ETH_P_IP:
309 return NP_IP;
310 case ETH_P_IPV6:
311 return NP_IPV6;
312 case ETH_P_IPX:
313 return NP_IPX;
314 case ETH_P_PPPTALK:
315 case ETH_P_ATALK:
316 return NP_AT;
317 case ETH_P_MPLS_UC:
318 return NP_MPLS_UC;
319 case ETH_P_MPLS_MC:
320 return NP_MPLS_MC;
321 }
322 return -1;
323 }
324
325 /* Translates an NP index into an ethertype */
326 static const int npindex_to_ethertype[NUM_NP] = {
327 ETH_P_IP,
328 ETH_P_IPV6,
329 ETH_P_IPX,
330 ETH_P_PPPTALK,
331 ETH_P_MPLS_UC,
332 ETH_P_MPLS_MC,
333 };
334
335 /*
336 * Locking shorthand.
337 */
338 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
339 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
340 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
341 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
342 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
343 ppp_recv_lock(ppp); } while (0)
344 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
345 ppp_xmit_unlock(ppp); } while (0)
346
347 /*
348 * /dev/ppp device routines.
349 * The /dev/ppp device is used by pppd to control the ppp unit.
350 * It supports the read, write, ioctl and poll functions.
351 * Open instances of /dev/ppp can be in one of three states:
352 * unattached, attached to a ppp unit, or attached to a ppp channel.
353 */
354 static int ppp_open(struct inode *inode, struct file *file)
355 {
356 /*
357 * This could (should?) be enforced by the permissions on /dev/ppp.
358 */
359 if (!capable(CAP_NET_ADMIN))
360 return -EPERM;
361 return 0;
362 }
363
364 static int ppp_release(struct inode *inode, struct file *file)
365 {
366 struct ppp_file *pf = file->private_data;
367 struct ppp *ppp;
368
369 if (pf) {
370 file->private_data = NULL;
371 if (pf->kind == INTERFACE) {
372 ppp = PF_TO_PPP(pf);
373 if (file == ppp->owner)
374 ppp_shutdown_interface(ppp);
375 }
376 if (atomic_dec_and_test(&pf->refcnt)) {
377 switch (pf->kind) {
378 case INTERFACE:
379 ppp_destroy_interface(PF_TO_PPP(pf));
380 break;
381 case CHANNEL:
382 ppp_destroy_channel(PF_TO_CHANNEL(pf));
383 break;
384 }
385 }
386 }
387 return 0;
388 }
389
390 static ssize_t ppp_read(struct file *file, char __user *buf,
391 size_t count, loff_t *ppos)
392 {
393 struct ppp_file *pf = file->private_data;
394 DECLARE_WAITQUEUE(wait, current);
395 ssize_t ret;
396 struct sk_buff *skb = NULL;
397
398 ret = count;
399
400 if (!pf)
401 return -ENXIO;
402 add_wait_queue(&pf->rwait, &wait);
403 for (;;) {
404 set_current_state(TASK_INTERRUPTIBLE);
405 skb = skb_dequeue(&pf->rq);
406 if (skb)
407 break;
408 ret = 0;
409 if (pf->dead)
410 break;
411 if (pf->kind == INTERFACE) {
412 /*
413 * Return 0 (EOF) on an interface that has no
414 * channels connected, unless it is looping
415 * network traffic (demand mode).
416 */
417 struct ppp *ppp = PF_TO_PPP(pf);
418 if (ppp->n_channels == 0
419 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
420 break;
421 }
422 ret = -EAGAIN;
423 if (file->f_flags & O_NONBLOCK)
424 break;
425 ret = -ERESTARTSYS;
426 if (signal_pending(current))
427 break;
428 schedule();
429 }
430 set_current_state(TASK_RUNNING);
431 remove_wait_queue(&pf->rwait, &wait);
432
433 if (!skb)
434 goto out;
435
436 ret = -EOVERFLOW;
437 if (skb->len > count)
438 goto outf;
439 ret = -EFAULT;
440 if (copy_to_user(buf, skb->data, skb->len))
441 goto outf;
442 ret = skb->len;
443
444 outf:
445 kfree_skb(skb);
446 out:
447 return ret;
448 }
449
450 static ssize_t ppp_write(struct file *file, const char __user *buf,
451 size_t count, loff_t *ppos)
452 {
453 struct ppp_file *pf = file->private_data;
454 struct sk_buff *skb;
455 ssize_t ret;
456
457 if (!pf)
458 return -ENXIO;
459 ret = -ENOMEM;
460 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
461 if (!skb)
462 goto out;
463 skb_reserve(skb, pf->hdrlen);
464 ret = -EFAULT;
465 if (copy_from_user(skb_put(skb, count), buf, count)) {
466 kfree_skb(skb);
467 goto out;
468 }
469
470 skb_queue_tail(&pf->xq, skb);
471
472 switch (pf->kind) {
473 case INTERFACE:
474 ppp_xmit_process(PF_TO_PPP(pf));
475 break;
476 case CHANNEL:
477 ppp_channel_push(PF_TO_CHANNEL(pf));
478 break;
479 }
480
481 ret = count;
482
483 out:
484 return ret;
485 }
486
487 /* No kernel lock - fine */
488 static unsigned int ppp_poll(struct file *file, poll_table *wait)
489 {
490 struct ppp_file *pf = file->private_data;
491 unsigned int mask;
492
493 if (!pf)
494 return 0;
495 poll_wait(file, &pf->rwait, wait);
496 mask = POLLOUT | POLLWRNORM;
497 if (skb_peek(&pf->rq))
498 mask |= POLLIN | POLLRDNORM;
499 if (pf->dead)
500 mask |= POLLHUP;
501 else if (pf->kind == INTERFACE) {
502 /* see comment in ppp_read */
503 struct ppp *ppp = PF_TO_PPP(pf);
504 if (ppp->n_channels == 0
505 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
506 mask |= POLLIN | POLLRDNORM;
507 }
508
509 return mask;
510 }
511
512 #ifdef CONFIG_PPP_FILTER
513 static int get_filter(void __user *arg, struct sock_filter **p)
514 {
515 struct sock_fprog uprog;
516 struct sock_filter *code = NULL;
517 int len, err;
518
519 if (copy_from_user(&uprog, arg, sizeof(uprog)))
520 return -EFAULT;
521
522 if (!uprog.len) {
523 *p = NULL;
524 return 0;
525 }
526
527 len = uprog.len * sizeof(struct sock_filter);
528 code = kmalloc(len, GFP_KERNEL);
529 if (code == NULL)
530 return -ENOMEM;
531
532 if (copy_from_user(code, uprog.filter, len)) {
533 kfree(code);
534 return -EFAULT;
535 }
536
537 err = sk_chk_filter(code, uprog.len);
538 if (err) {
539 kfree(code);
540 return err;
541 }
542
543 *p = code;
544 return uprog.len;
545 }
546 #endif /* CONFIG_PPP_FILTER */
547
548 static int ppp_ioctl(struct inode *inode, struct file *file,
549 unsigned int cmd, unsigned long arg)
550 {
551 struct ppp_file *pf = file->private_data;
552 struct ppp *ppp;
553 int err = -EFAULT, val, val2, i;
554 struct ppp_idle idle;
555 struct npioctl npi;
556 int unit, cflags;
557 struct slcompress *vj;
558 void __user *argp = (void __user *)arg;
559 int __user *p = argp;
560
561 if (!pf)
562 return ppp_unattached_ioctl(pf, file, cmd, arg);
563
564 if (cmd == PPPIOCDETACH) {
565 /*
566 * We have to be careful here... if the file descriptor
567 * has been dup'd, we could have another process in the
568 * middle of a poll using the same file *, so we had
569 * better not free the interface data structures -
570 * instead we fail the ioctl. Even in this case, we
571 * shut down the interface if we are the owner of it.
572 * Actually, we should get rid of PPPIOCDETACH, userland
573 * (i.e. pppd) could achieve the same effect by closing
574 * this fd and reopening /dev/ppp.
575 */
576 err = -EINVAL;
577 if (pf->kind == INTERFACE) {
578 ppp = PF_TO_PPP(pf);
579 if (file == ppp->owner)
580 ppp_shutdown_interface(ppp);
581 }
582 if (atomic_read(&file->f_count) <= 2) {
583 ppp_release(inode, file);
584 err = 0;
585 } else
586 printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%d\n",
587 atomic_read(&file->f_count));
588 return err;
589 }
590
591 if (pf->kind == CHANNEL) {
592 struct channel *pch = PF_TO_CHANNEL(pf);
593 struct ppp_channel *chan;
594
595 switch (cmd) {
596 case PPPIOCCONNECT:
597 if (get_user(unit, p))
598 break;
599 err = ppp_connect_channel(pch, unit);
600 break;
601
602 case PPPIOCDISCONN:
603 err = ppp_disconnect_channel(pch);
604 break;
605
606 default:
607 down_read(&pch->chan_sem);
608 chan = pch->chan;
609 err = -ENOTTY;
610 if (chan && chan->ops->ioctl)
611 err = chan->ops->ioctl(chan, cmd, arg);
612 up_read(&pch->chan_sem);
613 }
614 return err;
615 }
616
617 if (pf->kind != INTERFACE) {
618 /* can't happen */
619 printk(KERN_ERR "PPP: not interface or channel??\n");
620 return -EINVAL;
621 }
622
623 ppp = PF_TO_PPP(pf);
624 switch (cmd) {
625 case PPPIOCSMRU:
626 if (get_user(val, p))
627 break;
628 ppp->mru = val;
629 err = 0;
630 break;
631
632 case PPPIOCSFLAGS:
633 if (get_user(val, p))
634 break;
635 ppp_lock(ppp);
636 cflags = ppp->flags & ~val;
637 ppp->flags = val & SC_FLAG_BITS;
638 ppp_unlock(ppp);
639 if (cflags & SC_CCP_OPEN)
640 ppp_ccp_closed(ppp);
641 err = 0;
642 break;
643
644 case PPPIOCGFLAGS:
645 val = ppp->flags | ppp->xstate | ppp->rstate;
646 if (put_user(val, p))
647 break;
648 err = 0;
649 break;
650
651 case PPPIOCSCOMPRESS:
652 err = ppp_set_compress(ppp, arg);
653 break;
654
655 case PPPIOCGUNIT:
656 if (put_user(ppp->file.index, p))
657 break;
658 err = 0;
659 break;
660
661 case PPPIOCSDEBUG:
662 if (get_user(val, p))
663 break;
664 ppp->debug = val;
665 err = 0;
666 break;
667
668 case PPPIOCGDEBUG:
669 if (put_user(ppp->debug, p))
670 break;
671 err = 0;
672 break;
673
674 case PPPIOCGIDLE:
675 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
676 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
677 if (copy_to_user(argp, &idle, sizeof(idle)))
678 break;
679 err = 0;
680 break;
681
682 case PPPIOCSMAXCID:
683 if (get_user(val, p))
684 break;
685 val2 = 15;
686 if ((val >> 16) != 0) {
687 val2 = val >> 16;
688 val &= 0xffff;
689 }
690 vj = slhc_init(val2+1, val+1);
691 if (!vj) {
692 printk(KERN_ERR "PPP: no memory (VJ compressor)\n");
693 err = -ENOMEM;
694 break;
695 }
696 ppp_lock(ppp);
697 if (ppp->vj)
698 slhc_free(ppp->vj);
699 ppp->vj = vj;
700 ppp_unlock(ppp);
701 err = 0;
702 break;
703
704 case PPPIOCGNPMODE:
705 case PPPIOCSNPMODE:
706 if (copy_from_user(&npi, argp, sizeof(npi)))
707 break;
708 err = proto_to_npindex(npi.protocol);
709 if (err < 0)
710 break;
711 i = err;
712 if (cmd == PPPIOCGNPMODE) {
713 err = -EFAULT;
714 npi.mode = ppp->npmode[i];
715 if (copy_to_user(argp, &npi, sizeof(npi)))
716 break;
717 } else {
718 ppp->npmode[i] = npi.mode;
719 /* we may be able to transmit more packets now (??) */
720 netif_wake_queue(ppp->dev);
721 }
722 err = 0;
723 break;
724
725 #ifdef CONFIG_PPP_FILTER
726 case PPPIOCSPASS:
727 {
728 struct sock_filter *code;
729 err = get_filter(argp, &code);
730 if (err >= 0) {
731 ppp_lock(ppp);
732 kfree(ppp->pass_filter);
733 ppp->pass_filter = code;
734 ppp->pass_len = err;
735 ppp_unlock(ppp);
736 err = 0;
737 }
738 break;
739 }
740 case PPPIOCSACTIVE:
741 {
742 struct sock_filter *code;
743 err = get_filter(argp, &code);
744 if (err >= 0) {
745 ppp_lock(ppp);
746 kfree(ppp->active_filter);
747 ppp->active_filter = code;
748 ppp->active_len = err;
749 ppp_unlock(ppp);
750 err = 0;
751 }
752 break;
753 }
754 #endif /* CONFIG_PPP_FILTER */
755
756 #ifdef CONFIG_PPP_MULTILINK
757 case PPPIOCSMRRU:
758 if (get_user(val, p))
759 break;
760 ppp_recv_lock(ppp);
761 ppp->mrru = val;
762 ppp_recv_unlock(ppp);
763 err = 0;
764 break;
765 #endif /* CONFIG_PPP_MULTILINK */
766
767 default:
768 err = -ENOTTY;
769 }
770
771 return err;
772 }
773
774 static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file,
775 unsigned int cmd, unsigned long arg)
776 {
777 int unit, err = -EFAULT;
778 struct ppp *ppp;
779 struct channel *chan;
780 int __user *p = (int __user *)arg;
781
782 switch (cmd) {
783 case PPPIOCNEWUNIT:
784 /* Create a new ppp unit */
785 if (get_user(unit, p))
786 break;
787 ppp = ppp_create_interface(unit, &err);
788 if (!ppp)
789 break;
790 file->private_data = &ppp->file;
791 ppp->owner = file;
792 err = -EFAULT;
793 if (put_user(ppp->file.index, p))
794 break;
795 err = 0;
796 break;
797
798 case PPPIOCATTACH:
799 /* Attach to an existing ppp unit */
800 if (get_user(unit, p))
801 break;
802 mutex_lock(&all_ppp_mutex);
803 err = -ENXIO;
804 ppp = ppp_find_unit(unit);
805 if (ppp) {
806 atomic_inc(&ppp->file.refcnt);
807 file->private_data = &ppp->file;
808 err = 0;
809 }
810 mutex_unlock(&all_ppp_mutex);
811 break;
812
813 case PPPIOCATTCHAN:
814 if (get_user(unit, p))
815 break;
816 spin_lock_bh(&all_channels_lock);
817 err = -ENXIO;
818 chan = ppp_find_channel(unit);
819 if (chan) {
820 atomic_inc(&chan->file.refcnt);
821 file->private_data = &chan->file;
822 err = 0;
823 }
824 spin_unlock_bh(&all_channels_lock);
825 break;
826
827 default:
828 err = -ENOTTY;
829 }
830 return err;
831 }
832
833 static const struct file_operations ppp_device_fops = {
834 .owner = THIS_MODULE,
835 .read = ppp_read,
836 .write = ppp_write,
837 .poll = ppp_poll,
838 .ioctl = ppp_ioctl,
839 .open = ppp_open,
840 .release = ppp_release
841 };
842
843 #define PPP_MAJOR 108
844
845 /* Called at boot time if ppp is compiled into the kernel,
846 or at module load time (from init_module) if compiled as a module. */
847 static int __init ppp_init(void)
848 {
849 int err;
850
851 printk(KERN_INFO "PPP generic driver version " PPP_VERSION "\n");
852 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
853 if (!err) {
854 ppp_class = class_create(THIS_MODULE, "ppp");
855 if (IS_ERR(ppp_class)) {
856 err = PTR_ERR(ppp_class);
857 goto out_chrdev;
858 }
859 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), "ppp");
860 }
861
862 out:
863 if (err)
864 printk(KERN_ERR "failed to register PPP device (%d)\n", err);
865 return err;
866
867 out_chrdev:
868 unregister_chrdev(PPP_MAJOR, "ppp");
869 goto out;
870 }
871
872 /*
873 * Network interface unit routines.
874 */
875 static int
876 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
877 {
878 struct ppp *ppp = (struct ppp *) dev->priv;
879 int npi, proto;
880 unsigned char *pp;
881
882 npi = ethertype_to_npindex(ntohs(skb->protocol));
883 if (npi < 0)
884 goto outf;
885
886 /* Drop, accept or reject the packet */
887 switch (ppp->npmode[npi]) {
888 case NPMODE_PASS:
889 break;
890 case NPMODE_QUEUE:
891 /* it would be nice to have a way to tell the network
892 system to queue this one up for later. */
893 goto outf;
894 case NPMODE_DROP:
895 case NPMODE_ERROR:
896 goto outf;
897 }
898
899 /* Put the 2-byte PPP protocol number on the front,
900 making sure there is room for the address and control fields. */
901 if (skb_cow_head(skb, PPP_HDRLEN))
902 goto outf;
903
904 pp = skb_push(skb, 2);
905 proto = npindex_to_proto[npi];
906 pp[0] = proto >> 8;
907 pp[1] = proto;
908
909 netif_stop_queue(dev);
910 skb_queue_tail(&ppp->file.xq, skb);
911 ppp_xmit_process(ppp);
912 return 0;
913
914 outf:
915 kfree_skb(skb);
916 ++ppp->dev->stats.tx_dropped;
917 return 0;
918 }
919
920 static int
921 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
922 {
923 struct ppp *ppp = dev->priv;
924 int err = -EFAULT;
925 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
926 struct ppp_stats stats;
927 struct ppp_comp_stats cstats;
928 char *vers;
929
930 switch (cmd) {
931 case SIOCGPPPSTATS:
932 ppp_get_stats(ppp, &stats);
933 if (copy_to_user(addr, &stats, sizeof(stats)))
934 break;
935 err = 0;
936 break;
937
938 case SIOCGPPPCSTATS:
939 memset(&cstats, 0, sizeof(cstats));
940 if (ppp->xc_state)
941 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
942 if (ppp->rc_state)
943 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
944 if (copy_to_user(addr, &cstats, sizeof(cstats)))
945 break;
946 err = 0;
947 break;
948
949 case SIOCGPPPVER:
950 vers = PPP_VERSION;
951 if (copy_to_user(addr, vers, strlen(vers) + 1))
952 break;
953 err = 0;
954 break;
955
956 default:
957 err = -EINVAL;
958 }
959
960 return err;
961 }
962
963 static void ppp_setup(struct net_device *dev)
964 {
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 */
981 static void
982 ppp_xmit_process(struct ppp *ppp)
983 {
984 struct sk_buff *skb;
985
986 ppp_xmit_lock(ppp);
987 if (ppp->dev) {
988 ppp_push(ppp);
989 while (!ppp->xmit_pending
990 && (skb = skb_dequeue(&ppp->file.xq)))
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. */
994 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
995 netif_wake_queue(ppp->dev);
996 }
997 ppp_xmit_unlock(ppp);
998 }
999
1000 static inline struct sk_buff *
1001 pad_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
1050 /*
1051 * Compress and send a frame.
1052 * The caller should have locked the xmit path,
1053 * and xmit_pending should be 0.
1054 */
1055 static void
1056 ppp_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
1089 ++ppp->dev->stats.tx_packets;
1090 ppp->dev->stats.tx_bytes += skb->len - 2;
1091
1092 switch (proto) {
1093 case PPP_IP:
1094 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
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);
1099 if (!new_skb) {
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 */
1134 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state
1135 && proto != PPP_LCP && proto != PPP_CCP) {
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");
1139 goto drop;
1140 }
1141 skb = pad_compress_skb(ppp, skb);
1142 if (!skb)
1143 goto drop;
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:
1163 if (skb)
1164 kfree_skb(skb);
1165 ++ppp->dev->stats.tx_errors;
1166 }
1167
1168 /*
1169 * Try to send the frame in xmit_pending.
1170 * The caller should have the xmit path locked.
1171 */
1172 static void
1173 ppp_push(struct ppp *ppp)
1174 {
1175 struct list_head *list;
1176 struct channel *pch;
1177 struct sk_buff *skb = ppp->xmit_pending;
1178
1179 if (!skb)
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 */
1224 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1225 {
1226 int len, fragsize;
1227 int i, bits, hdrlen, mtu;
1228 int flen;
1229 int navail, nfree;
1230 int nbigger;
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
1237 nfree = 0; /* # channels which have no packet already queued */
1238 navail = 0; /* total # of usable channels (not deregistered) */
1239 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1240 i = 0;
1241 list_for_each_entry(pch, &ppp->channels, clist) {
1242 navail += pch->avail = (pch->chan != NULL);
1243 if (pch->avail) {
1244 if (skb_queue_empty(&pch->file.xq) ||
1245 !pch->had_frag) {
1246 pch->avail = 2;
1247 ++nfree;
1248 }
1249 if (!pch->had_frag && i < ppp->nxchan)
1250 ppp->nxchan = i;
1251 }
1252 ++i;
1253 }
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)
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
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 */
1278 fragsize = len;
1279 if (nfree > 1)
1280 fragsize = DIV_ROUND_UP(fragsize, nfree);
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;
1284
1285 /* skip to the channel after the one we last used
1286 and start at that one */
1287 list = &ppp->channels;
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;
1298 while (nfree > 0 || len > 0) {
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
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
1321 /* check the channel's mtu and whether it is still attached. */
1322 spin_lock_bh(&pch->downl);
1323 if (pch->chan == NULL) {
1324 /* can't use this channel, it's being deregistered */
1325 spin_unlock_bh(&pch->downl);
1326 pch->avail = 0;
1327 if (--navail == 0)
1328 break;
1329 continue;
1330 }
1331
1332 /*
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.
1337 */
1338 if (fragsize > len)
1339 fragsize = len;
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);
1349 if (!frag)
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;
1364 }
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;
1382 if (!skb_queue_empty(&pch->file.xq) ||
1383 !chan->ops->start_xmit(chan, frag))
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;
1390 spin_unlock_bh(&pch->downl);
1391
1392 if (--nbigger == 0 && fragsize > 0)
1393 --fragsize;
1394 }
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");
1403 ++ppp->dev->stats.tx_errors;
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 */
1412 static void
1413 ppp_channel_push(struct channel *pch)
1414 {
1415 struct sk_buff *skb;
1416 struct ppp *ppp;
1417
1418 spin_lock_bh(&pch->downl);
1419 if (pch->chan) {
1420 while (!skb_queue_empty(&pch->file.xq)) {
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 */
1434 if (skb_queue_empty(&pch->file.xq)) {
1435 read_lock_bh(&pch->upl);
1436 ppp = pch->ppp;
1437 if (ppp)
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
1451 static inline void
1452 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1453 {
1454 ppp_recv_lock(ppp);
1455 /* ppp->dev == 0 means interface is closing down */
1456 if (ppp->dev)
1457 ppp_receive_frame(ppp, skb, pch);
1458 else
1459 kfree_skb(skb);
1460 ppp_recv_unlock(ppp);
1461 }
1462
1463 void
1464 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1465 {
1466 struct channel *pch = chan->ppp;
1467 int proto;
1468
1469 if (!pch || skb->len == 0) {
1470 kfree_skb(skb);
1471 return;
1472 }
1473
1474 proto = PPP_PROTO(skb);
1475 read_lock_bh(&pch->upl);
1476 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
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
1481 && (skb = skb_dequeue(&pch->file.rq)))
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 */
1491 void
1492 ppp_input_error(struct ppp_channel *chan, int code)
1493 {
1494 struct channel *pch = chan->ppp;
1495 struct sk_buff *skb;
1496
1497 if (!pch)
1498 return;
1499
1500 read_lock_bh(&pch->upl);
1501 if (pch->ppp) {
1502 skb = alloc_skb(0, GFP_ATOMIC);
1503 if (skb) {
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 */
1516 static void
1517 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1518 {
1519 if (pskb_may_pull(skb, 2)) {
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 */
1532 ++ppp->dev->stats.rx_length_errors;
1533
1534 kfree_skb(skb);
1535 ppp_receive_error(ppp);
1536 }
1537
1538 static void
1539 ppp_receive_error(struct ppp *ppp)
1540 {
1541 ++ppp->dev->stats.rx_errors;
1542 if (ppp->vj)
1543 slhc_toss(ppp->vj);
1544 }
1545
1546 static void
1547 ppp_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 */
1557 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)
1558 && (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1559 skb = ppp_decompress_frame(ppp, skb);
1560
1561 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1562 goto err;
1563
1564 proto = PPP_PROTO(skb);
1565 switch (proto) {
1566 case PPP_VJC_COMP:
1567 /* decompress VJ compressed packets */
1568 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1569 goto err;
1570
1571 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1572 /* copy to a new sk_buff with more tailroom */
1573 ns = dev_alloc_skb(skb->len + 128);
1574 if (!ns) {
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 }
1583 else
1584 skb->ip_summed = CHECKSUM_NONE;
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:
1600 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1601 goto err;
1602
1603 /* Until we fix the decompressor need to make sure
1604 * data portion is linear.
1605 */
1606 if (!pskb_may_pull(skb, skb->len))
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
1621 ++ppp->dev->stats.rx_packets;
1622 ppp->dev->stats.rx_bytes += skb->len - 2;
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
1630 && (skb = skb_dequeue(&ppp->file.rq)))
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 */
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
1663 #endif /* CONFIG_PPP_FILTER */
1664 ppp->last_recv = jiffies;
1665
1666 if ((ppp->dev->flags & IFF_UP) == 0
1667 || ppp->npmode[npi] != NPMODE_PASS) {
1668 kfree_skb(skb);
1669 } else {
1670 /* chop off protocol */
1671 skb_pull_rcsum(skb, 2);
1672 skb->dev = ppp->dev;
1673 skb->protocol = htons(npindex_to_ethertype[npi]);
1674 skb_reset_mac_header(skb);
1675 netif_rx(skb);
1676 ppp->dev->last_rx = jiffies;
1677 }
1678 }
1679 return;
1680
1681 err:
1682 kfree_skb(skb);
1683 ppp_receive_error(ppp);
1684 }
1685
1686 static struct sk_buff *
1687 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1688 {
1689 int proto = PPP_PROTO(skb);
1690 struct sk_buff *ns;
1691 int len;
1692
1693 /* Until we fix all the decompressor's need to make sure
1694 * data portion is linear.
1695 */
1696 if (!pskb_may_pull(skb, skb->len))
1697 goto err;
1698
1699 if (proto == PPP_COMP) {
1700 int obuff_size;
1701
1702 switch(ppp->rcomp->compress_proto) {
1703 case CI_MPPE:
1704 obuff_size = ppp->mru + PPP_HDRLEN + 1;
1705 break;
1706 default:
1707 obuff_size = ppp->mru + PPP_HDRLEN;
1708 break;
1709 }
1710
1711 ns = dev_alloc_skb(obuff_size);
1712 if (!ns) {
1713 printk(KERN_ERR "ppp_decompress_frame: no memory\n");
1714 goto err;
1715 }
1716 /* the decompressor still expects the A/C bytes in the hdr */
1717 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1718 skb->len + 2, ns->data, obuff_size);
1719 if (len < 0) {
1720 /* Pass the compressed frame to pppd as an
1721 error indication. */
1722 if (len == DECOMP_FATALERROR)
1723 ppp->rstate |= SC_DC_FERROR;
1724 kfree_skb(ns);
1725 goto err;
1726 }
1727
1728 kfree_skb(skb);
1729 skb = ns;
1730 skb_put(skb, len);
1731 skb_pull(skb, 2); /* pull off the A/C bytes */
1732
1733 } else {
1734 /* Uncompressed frame - pass to decompressor so it
1735 can update its dictionary if necessary. */
1736 if (ppp->rcomp->incomp)
1737 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1738 skb->len + 2);
1739 }
1740
1741 return skb;
1742
1743 err:
1744 ppp->rstate |= SC_DC_ERROR;
1745 ppp_receive_error(ppp);
1746 return skb;
1747 }
1748
1749 #ifdef CONFIG_PPP_MULTILINK
1750 /*
1751 * Receive a multilink frame.
1752 * We put it on the reconstruction queue and then pull off
1753 * as many completed frames as we can.
1754 */
1755 static void
1756 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1757 {
1758 u32 mask, seq;
1759 struct channel *ch;
1760 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1761
1762 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
1763 goto err; /* no good, throw it away */
1764
1765 /* Decode sequence number and begin/end bits */
1766 if (ppp->flags & SC_MP_SHORTSEQ) {
1767 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1768 mask = 0xfff;
1769 } else {
1770 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1771 mask = 0xffffff;
1772 }
1773 skb->BEbits = skb->data[2];
1774 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
1775
1776 /*
1777 * Do protocol ID decompression on the first fragment of each packet.
1778 */
1779 if ((skb->BEbits & B) && (skb->data[0] & 1))
1780 *skb_push(skb, 1) = 0;
1781
1782 /*
1783 * Expand sequence number to 32 bits, making it as close
1784 * as possible to ppp->minseq.
1785 */
1786 seq |= ppp->minseq & ~mask;
1787 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
1788 seq += mask + 1;
1789 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
1790 seq -= mask + 1; /* should never happen */
1791 skb->sequence = seq;
1792 pch->lastseq = seq;
1793
1794 /*
1795 * If this packet comes before the next one we were expecting,
1796 * drop it.
1797 */
1798 if (seq_before(seq, ppp->nextseq)) {
1799 kfree_skb(skb);
1800 ++ppp->dev->stats.rx_dropped;
1801 ppp_receive_error(ppp);
1802 return;
1803 }
1804
1805 /*
1806 * Reevaluate minseq, the minimum over all channels of the
1807 * last sequence number received on each channel. Because of
1808 * the increasing sequence number rule, we know that any fragment
1809 * before `minseq' which hasn't arrived is never going to arrive.
1810 * The list of channels can't change because we have the receive
1811 * side of the ppp unit locked.
1812 */
1813 list_for_each_entry(ch, &ppp->channels, clist) {
1814 if (seq_before(ch->lastseq, seq))
1815 seq = ch->lastseq;
1816 }
1817 if (seq_before(ppp->minseq, seq))
1818 ppp->minseq = seq;
1819
1820 /* Put the fragment on the reconstruction queue */
1821 ppp_mp_insert(ppp, skb);
1822
1823 /* If the queue is getting long, don't wait any longer for packets
1824 before the start of the queue. */
1825 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN
1826 && seq_before(ppp->minseq, ppp->mrq.next->sequence))
1827 ppp->minseq = ppp->mrq.next->sequence;
1828
1829 /* Pull completed packets off the queue and receive them. */
1830 while ((skb = ppp_mp_reconstruct(ppp)))
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 */
1844 static void
1845 ppp_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. */
1853 for (p = list->next; p != (struct sk_buff *)list; p = p->next)
1854 if (seq_before(seq, p->sequence))
1855 break;
1856 __skb_insert(skb, p->prev, p, list);
1857 }
1858
1859 /*
1860 * Reconstruct a packet from the MP fragment queue.
1861 * We go through increasing sequence numbers until we find a
1862 * complete packet, or we get to the sequence number for a fragment
1863 * which hasn't arrived but might still do so.
1864 */
1865 static struct sk_buff *
1866 ppp_mp_reconstruct(struct ppp *ppp)
1867 {
1868 u32 seq = ppp->nextseq;
1869 u32 minseq = ppp->minseq;
1870 struct sk_buff_head *list = &ppp->mrq;
1871 struct sk_buff *p, *next;
1872 struct sk_buff *head, *tail;
1873 struct sk_buff *skb = NULL;
1874 int lost = 0, len = 0;
1875
1876 if (ppp->mrru == 0) /* do nothing until mrru is set */
1877 return NULL;
1878 head = list->next;
1879 tail = NULL;
1880 for (p = head; p != (struct sk_buff *) list; p = next) {
1881 next = p->next;
1882 if (seq_before(p->sequence, seq)) {
1883 /* this can't happen, anyway ignore the skb */
1884 printk(KERN_ERR "ppp_mp_reconstruct bad seq %u < %u\n",
1885 p->sequence, seq);
1886 head = next;
1887 continue;
1888 }
1889 if (p->sequence != seq) {
1890 /* Fragment `seq' is missing. If it is after
1891 minseq, it might arrive later, so stop here. */
1892 if (seq_after(seq, minseq))
1893 break;
1894 /* Fragment `seq' is lost, keep going. */
1895 lost = 1;
1896 seq = seq_before(minseq, p->sequence)?
1897 minseq + 1: p->sequence;
1898 next = p;
1899 continue;
1900 }
1901
1902 /*
1903 * At this point we know that all the fragments from
1904 * ppp->nextseq to seq are either present or lost.
1905 * Also, there are no complete packets in the queue
1906 * that have no missing fragments and end before this
1907 * fragment.
1908 */
1909
1910 /* B bit set indicates this fragment starts a packet */
1911 if (p->BEbits & B) {
1912 head = p;
1913 lost = 0;
1914 len = 0;
1915 }
1916
1917 len += p->len;
1918
1919 /* Got a complete packet yet? */
1920 if (lost == 0 && (p->BEbits & E) && (head->BEbits & B)) {
1921 if (len > ppp->mrru + 2) {
1922 ++ppp->dev->stats.rx_length_errors;
1923 printk(KERN_DEBUG "PPP: reconstructed packet"
1924 " is too long (%d)\n", len);
1925 } else if (p == head) {
1926 /* fragment is complete packet - reuse skb */
1927 tail = p;
1928 skb = skb_get(p);
1929 break;
1930 } else if ((skb = dev_alloc_skb(len)) == NULL) {
1931 ++ppp->dev->stats.rx_missed_errors;
1932 printk(KERN_DEBUG "PPP: no memory for "
1933 "reconstructed packet");
1934 } else {
1935 tail = p;
1936 break;
1937 }
1938 ppp->nextseq = seq + 1;
1939 }
1940
1941 /*
1942 * If this is the ending fragment of a packet,
1943 * and we haven't found a complete valid packet yet,
1944 * we can discard up to and including this fragment.
1945 */
1946 if (p->BEbits & E)
1947 head = next;
1948
1949 ++seq;
1950 }
1951
1952 /* If we have a complete packet, copy it all into one skb. */
1953 if (tail != NULL) {
1954 /* If we have discarded any fragments,
1955 signal a receive error. */
1956 if (head->sequence != ppp->nextseq) {
1957 if (ppp->debug & 1)
1958 printk(KERN_DEBUG " missed pkts %u..%u\n",
1959 ppp->nextseq, head->sequence-1);
1960 ++ppp->dev->stats.rx_dropped;
1961 ppp_receive_error(ppp);
1962 }
1963
1964 if (head != tail)
1965 /* copy to a single skb */
1966 for (p = head; p != tail->next; p = p->next)
1967 skb_copy_bits(p, 0, skb_put(skb, p->len), p->len);
1968 ppp->nextseq = tail->sequence + 1;
1969 head = tail->next;
1970 }
1971
1972 /* Discard all the skbuffs that we have copied the data out of
1973 or that we can't use. */
1974 while ((p = list->next) != head) {
1975 __skb_unlink(p, list);
1976 kfree_skb(p);
1977 }
1978
1979 return skb;
1980 }
1981 #endif /* CONFIG_PPP_MULTILINK */
1982
1983 /*
1984 * Channel interface.
1985 */
1986
1987 /*
1988 * Create a new, unattached ppp channel.
1989 */
1990 int
1991 ppp_register_channel(struct ppp_channel *chan)
1992 {
1993 struct channel *pch;
1994
1995 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
1996 if (!pch)
1997 return -ENOMEM;
1998 pch->ppp = NULL;
1999 pch->chan = chan;
2000 chan->ppp = pch;
2001 init_ppp_file(&pch->file, CHANNEL);
2002 pch->file.hdrlen = chan->hdrlen;
2003 #ifdef CONFIG_PPP_MULTILINK
2004 pch->lastseq = -1;
2005 #endif /* CONFIG_PPP_MULTILINK */
2006 init_rwsem(&pch->chan_sem);
2007 spin_lock_init(&pch->downl);
2008 rwlock_init(&pch->upl);
2009 spin_lock_bh(&all_channels_lock);
2010 pch->file.index = ++last_channel_index;
2011 list_add(&pch->list, &new_channels);
2012 atomic_inc(&channel_count);
2013 spin_unlock_bh(&all_channels_lock);
2014 return 0;
2015 }
2016
2017 /*
2018 * Return the index of a channel.
2019 */
2020 int ppp_channel_index(struct ppp_channel *chan)
2021 {
2022 struct channel *pch = chan->ppp;
2023
2024 if (pch)
2025 return pch->file.index;
2026 return -1;
2027 }
2028
2029 /*
2030 * Return the PPP unit number to which a channel is connected.
2031 */
2032 int ppp_unit_number(struct ppp_channel *chan)
2033 {
2034 struct channel *pch = chan->ppp;
2035 int unit = -1;
2036
2037 if (pch) {
2038 read_lock_bh(&pch->upl);
2039 if (pch->ppp)
2040 unit = pch->ppp->file.index;
2041 read_unlock_bh(&pch->upl);
2042 }
2043 return unit;
2044 }
2045
2046 /*
2047 * Disconnect a channel from the generic layer.
2048 * This must be called in process context.
2049 */
2050 void
2051 ppp_unregister_channel(struct ppp_channel *chan)
2052 {
2053 struct channel *pch = chan->ppp;
2054
2055 if (!pch)
2056 return; /* should never happen */
2057 chan->ppp = NULL;
2058
2059 /*
2060 * This ensures that we have returned from any calls into the
2061 * the channel's start_xmit or ioctl routine before we proceed.
2062 */
2063 down_write(&pch->chan_sem);
2064 spin_lock_bh(&pch->downl);
2065 pch->chan = NULL;
2066 spin_unlock_bh(&pch->downl);
2067 up_write(&pch->chan_sem);
2068 ppp_disconnect_channel(pch);
2069 spin_lock_bh(&all_channels_lock);
2070 list_del(&pch->list);
2071 spin_unlock_bh(&all_channels_lock);
2072 pch->file.dead = 1;
2073 wake_up_interruptible(&pch->file.rwait);
2074 if (atomic_dec_and_test(&pch->file.refcnt))
2075 ppp_destroy_channel(pch);
2076 }
2077
2078 /*
2079 * Callback from a channel when it can accept more to transmit.
2080 * This should be called at BH/softirq level, not interrupt level.
2081 */
2082 void
2083 ppp_output_wakeup(struct ppp_channel *chan)
2084 {
2085 struct channel *pch = chan->ppp;
2086
2087 if (!pch)
2088 return;
2089 ppp_channel_push(pch);
2090 }
2091
2092 /*
2093 * Compression control.
2094 */
2095
2096 /* Process the PPPIOCSCOMPRESS ioctl. */
2097 static int
2098 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2099 {
2100 int err;
2101 struct compressor *cp, *ocomp;
2102 struct ppp_option_data data;
2103 void *state, *ostate;
2104 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2105
2106 err = -EFAULT;
2107 if (copy_from_user(&data, (void __user *) arg, sizeof(data))
2108 || (data.length <= CCP_MAX_OPTION_LENGTH
2109 && copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2110 goto out;
2111 err = -EINVAL;
2112 if (data.length > CCP_MAX_OPTION_LENGTH
2113 || ccp_option[1] < 2 || ccp_option[1] > data.length)
2114 goto out;
2115
2116 cp = find_compressor(ccp_option[0]);
2117 #ifdef CONFIG_KMOD
2118 if (!cp) {
2119 request_module("ppp-compress-%d", ccp_option[0]);
2120 cp = find_compressor(ccp_option[0]);
2121 }
2122 #endif /* CONFIG_KMOD */
2123 if (!cp)
2124 goto out;
2125
2126 err = -ENOBUFS;
2127 if (data.transmit) {
2128 state = cp->comp_alloc(ccp_option, data.length);
2129 if (state) {
2130 ppp_xmit_lock(ppp);
2131 ppp->xstate &= ~SC_COMP_RUN;
2132 ocomp = ppp->xcomp;
2133 ostate = ppp->xc_state;
2134 ppp->xcomp = cp;
2135 ppp->xc_state = state;
2136 ppp_xmit_unlock(ppp);
2137 if (ostate) {
2138 ocomp->comp_free(ostate);
2139 module_put(ocomp->owner);
2140 }
2141 err = 0;
2142 } else
2143 module_put(cp->owner);
2144
2145 } else {
2146 state = cp->decomp_alloc(ccp_option, data.length);
2147 if (state) {
2148 ppp_recv_lock(ppp);
2149 ppp->rstate &= ~SC_DECOMP_RUN;
2150 ocomp = ppp->rcomp;
2151 ostate = ppp->rc_state;
2152 ppp->rcomp = cp;
2153 ppp->rc_state = state;
2154 ppp_recv_unlock(ppp);
2155 if (ostate) {
2156 ocomp->decomp_free(ostate);
2157 module_put(ocomp->owner);
2158 }
2159 err = 0;
2160 } else
2161 module_put(cp->owner);
2162 }
2163
2164 out:
2165 return err;
2166 }
2167
2168 /*
2169 * Look at a CCP packet and update our state accordingly.
2170 * We assume the caller has the xmit or recv path locked.
2171 */
2172 static void
2173 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2174 {
2175 unsigned char *dp;
2176 int len;
2177
2178 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2179 return; /* no header */
2180 dp = skb->data + 2;
2181
2182 switch (CCP_CODE(dp)) {
2183 case CCP_CONFREQ:
2184
2185 /* A ConfReq starts negotiation of compression
2186 * in one direction of transmission,
2187 * and hence brings it down...but which way?
2188 *
2189 * Remember:
2190 * A ConfReq indicates what the sender would like to receive
2191 */
2192 if(inbound)
2193 /* He is proposing what I should send */
2194 ppp->xstate &= ~SC_COMP_RUN;
2195 else
2196 /* I am proposing to what he should send */
2197 ppp->rstate &= ~SC_DECOMP_RUN;
2198
2199 break;
2200
2201 case CCP_TERMREQ:
2202 case CCP_TERMACK:
2203 /*
2204 * CCP is going down, both directions of transmission
2205 */
2206 ppp->rstate &= ~SC_DECOMP_RUN;
2207 ppp->xstate &= ~SC_COMP_RUN;
2208 break;
2209
2210 case CCP_CONFACK:
2211 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2212 break;
2213 len = CCP_LENGTH(dp);
2214 if (!pskb_may_pull(skb, len + 2))
2215 return; /* too short */
2216 dp += CCP_HDRLEN;
2217 len -= CCP_HDRLEN;
2218 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2219 break;
2220 if (inbound) {
2221 /* we will start receiving compressed packets */
2222 if (!ppp->rc_state)
2223 break;
2224 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2225 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2226 ppp->rstate |= SC_DECOMP_RUN;
2227 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2228 }
2229 } else {
2230 /* we will soon start sending compressed packets */
2231 if (!ppp->xc_state)
2232 break;
2233 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2234 ppp->file.index, 0, ppp->debug))
2235 ppp->xstate |= SC_COMP_RUN;
2236 }
2237 break;
2238
2239 case CCP_RESETACK:
2240 /* reset the [de]compressor */
2241 if ((ppp->flags & SC_CCP_UP) == 0)
2242 break;
2243 if (inbound) {
2244 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2245 ppp->rcomp->decomp_reset(ppp->rc_state);
2246 ppp->rstate &= ~SC_DC_ERROR;
2247 }
2248 } else {
2249 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2250 ppp->xcomp->comp_reset(ppp->xc_state);
2251 }
2252 break;
2253 }
2254 }
2255
2256 /* Free up compression resources. */
2257 static void
2258 ppp_ccp_closed(struct ppp *ppp)
2259 {
2260 void *xstate, *rstate;
2261 struct compressor *xcomp, *rcomp;
2262
2263 ppp_lock(ppp);
2264 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2265 ppp->xstate = 0;
2266 xcomp = ppp->xcomp;
2267 xstate = ppp->xc_state;
2268 ppp->xc_state = NULL;
2269 ppp->rstate = 0;
2270 rcomp = ppp->rcomp;
2271 rstate = ppp->rc_state;
2272 ppp->rc_state = NULL;
2273 ppp_unlock(ppp);
2274
2275 if (xstate) {
2276 xcomp->comp_free(xstate);
2277 module_put(xcomp->owner);
2278 }
2279 if (rstate) {
2280 rcomp->decomp_free(rstate);
2281 module_put(rcomp->owner);
2282 }
2283 }
2284
2285 /* List of compressors. */
2286 static LIST_HEAD(compressor_list);
2287 static DEFINE_SPINLOCK(compressor_list_lock);
2288
2289 struct compressor_entry {
2290 struct list_head list;
2291 struct compressor *comp;
2292 };
2293
2294 static struct compressor_entry *
2295 find_comp_entry(int proto)
2296 {
2297 struct compressor_entry *ce;
2298
2299 list_for_each_entry(ce, &compressor_list, list) {
2300 if (ce->comp->compress_proto == proto)
2301 return ce;
2302 }
2303 return NULL;
2304 }
2305
2306 /* Register a compressor */
2307 int
2308 ppp_register_compressor(struct compressor *cp)
2309 {
2310 struct compressor_entry *ce;
2311 int ret;
2312 spin_lock(&compressor_list_lock);
2313 ret = -EEXIST;
2314 if (find_comp_entry(cp->compress_proto))
2315 goto out;
2316 ret = -ENOMEM;
2317 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2318 if (!ce)
2319 goto out;
2320 ret = 0;
2321 ce->comp = cp;
2322 list_add(&ce->list, &compressor_list);
2323 out:
2324 spin_unlock(&compressor_list_lock);
2325 return ret;
2326 }
2327
2328 /* Unregister a compressor */
2329 void
2330 ppp_unregister_compressor(struct compressor *cp)
2331 {
2332 struct compressor_entry *ce;
2333
2334 spin_lock(&compressor_list_lock);
2335 ce = find_comp_entry(cp->compress_proto);
2336 if (ce && ce->comp == cp) {
2337 list_del(&ce->list);
2338 kfree(ce);
2339 }
2340 spin_unlock(&compressor_list_lock);
2341 }
2342
2343 /* Find a compressor. */
2344 static struct compressor *
2345 find_compressor(int type)
2346 {
2347 struct compressor_entry *ce;
2348 struct compressor *cp = NULL;
2349
2350 spin_lock(&compressor_list_lock);
2351 ce = find_comp_entry(type);
2352 if (ce) {
2353 cp = ce->comp;
2354 if (!try_module_get(cp->owner))
2355 cp = NULL;
2356 }
2357 spin_unlock(&compressor_list_lock);
2358 return cp;
2359 }
2360
2361 /*
2362 * Miscelleneous stuff.
2363 */
2364
2365 static void
2366 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2367 {
2368 struct slcompress *vj = ppp->vj;
2369
2370 memset(st, 0, sizeof(*st));
2371 st->p.ppp_ipackets = ppp->dev->stats.rx_packets;
2372 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2373 st->p.ppp_ibytes = ppp->dev->stats.rx_bytes;
2374 st->p.ppp_opackets = ppp->dev->stats.tx_packets;
2375 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2376 st->p.ppp_obytes = ppp->dev->stats.tx_bytes;
2377 if (!vj)
2378 return;
2379 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2380 st->vj.vjs_compressed = vj->sls_o_compressed;
2381 st->vj.vjs_searches = vj->sls_o_searches;
2382 st->vj.vjs_misses = vj->sls_o_misses;
2383 st->vj.vjs_errorin = vj->sls_i_error;
2384 st->vj.vjs_tossed = vj->sls_i_tossed;
2385 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2386 st->vj.vjs_compressedin = vj->sls_i_compressed;
2387 }
2388
2389 /*
2390 * Stuff for handling the lists of ppp units and channels
2391 * and for initialization.
2392 */
2393
2394 /*
2395 * Create a new ppp interface unit. Fails if it can't allocate memory
2396 * or if there is already a unit with the requested number.
2397 * unit == -1 means allocate a new number.
2398 */
2399 static struct ppp *
2400 ppp_create_interface(int unit, int *retp)
2401 {
2402 struct ppp *ppp;
2403 struct net_device *dev = NULL;
2404 int ret = -ENOMEM;
2405 int i;
2406
2407 ppp = kzalloc(sizeof(struct ppp), GFP_KERNEL);
2408 if (!ppp)
2409 goto out;
2410 dev = alloc_netdev(0, "", ppp_setup);
2411 if (!dev)
2412 goto out1;
2413
2414 ppp->mru = PPP_MRU;
2415 init_ppp_file(&ppp->file, INTERFACE);
2416 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2417 for (i = 0; i < NUM_NP; ++i)
2418 ppp->npmode[i] = NPMODE_PASS;
2419 INIT_LIST_HEAD(&ppp->channels);
2420 spin_lock_init(&ppp->rlock);
2421 spin_lock_init(&ppp->wlock);
2422 #ifdef CONFIG_PPP_MULTILINK
2423 ppp->minseq = -1;
2424 skb_queue_head_init(&ppp->mrq);
2425 #endif /* CONFIG_PPP_MULTILINK */
2426 ppp->dev = dev;
2427 dev->priv = ppp;
2428
2429 dev->hard_start_xmit = ppp_start_xmit;
2430 dev->do_ioctl = ppp_net_ioctl;
2431
2432 ret = -EEXIST;
2433 mutex_lock(&all_ppp_mutex);
2434 if (unit < 0)
2435 unit = cardmap_find_first_free(all_ppp_units);
2436 else if (cardmap_get(all_ppp_units, unit) != NULL)
2437 goto out2; /* unit already exists */
2438
2439 /* Initialize the new ppp unit */
2440 ppp->file.index = unit;
2441 sprintf(dev->name, "ppp%d", unit);
2442
2443 ret = register_netdev(dev);
2444 if (ret != 0) {
2445 printk(KERN_ERR "PPP: couldn't register device %s (%d)\n",
2446 dev->name, ret);
2447 goto out2;
2448 }
2449
2450 atomic_inc(&ppp_unit_count);
2451 ret = cardmap_set(&all_ppp_units, unit, ppp);
2452 if (ret != 0)
2453 goto out3;
2454
2455 mutex_unlock(&all_ppp_mutex);
2456 *retp = 0;
2457 return ppp;
2458
2459 out3:
2460 atomic_dec(&ppp_unit_count);
2461 unregister_netdev(dev);
2462 out2:
2463 mutex_unlock(&all_ppp_mutex);
2464 free_netdev(dev);
2465 out1:
2466 kfree(ppp);
2467 out:
2468 *retp = ret;
2469 return NULL;
2470 }
2471
2472 /*
2473 * Initialize a ppp_file structure.
2474 */
2475 static void
2476 init_ppp_file(struct ppp_file *pf, int kind)
2477 {
2478 pf->kind = kind;
2479 skb_queue_head_init(&pf->xq);
2480 skb_queue_head_init(&pf->rq);
2481 atomic_set(&pf->refcnt, 1);
2482 init_waitqueue_head(&pf->rwait);
2483 }
2484
2485 /*
2486 * Take down a ppp interface unit - called when the owning file
2487 * (the one that created the unit) is closed or detached.
2488 */
2489 static void ppp_shutdown_interface(struct ppp *ppp)
2490 {
2491 struct net_device *dev;
2492
2493 mutex_lock(&all_ppp_mutex);
2494 ppp_lock(ppp);
2495 dev = ppp->dev;
2496 ppp->dev = NULL;
2497 ppp_unlock(ppp);
2498 /* This will call dev_close() for us. */
2499 if (dev) {
2500 unregister_netdev(dev);
2501 free_netdev(dev);
2502 }
2503 cardmap_set(&all_ppp_units, ppp->file.index, NULL);
2504 ppp->file.dead = 1;
2505 ppp->owner = NULL;
2506 wake_up_interruptible(&ppp->file.rwait);
2507 mutex_unlock(&all_ppp_mutex);
2508 }
2509
2510 /*
2511 * Free the memory used by a ppp unit. This is only called once
2512 * there are no channels connected to the unit and no file structs
2513 * that reference the unit.
2514 */
2515 static void ppp_destroy_interface(struct ppp *ppp)
2516 {
2517 atomic_dec(&ppp_unit_count);
2518
2519 if (!ppp->file.dead || ppp->n_channels) {
2520 /* "can't happen" */
2521 printk(KERN_ERR "ppp: destroying ppp struct %p but dead=%d "
2522 "n_channels=%d !\n", ppp, ppp->file.dead,
2523 ppp->n_channels);
2524 return;
2525 }
2526
2527 ppp_ccp_closed(ppp);
2528 if (ppp->vj) {
2529 slhc_free(ppp->vj);
2530 ppp->vj = NULL;
2531 }
2532 skb_queue_purge(&ppp->file.xq);
2533 skb_queue_purge(&ppp->file.rq);
2534 #ifdef CONFIG_PPP_MULTILINK
2535 skb_queue_purge(&ppp->mrq);
2536 #endif /* CONFIG_PPP_MULTILINK */
2537 #ifdef CONFIG_PPP_FILTER
2538 kfree(ppp->pass_filter);
2539 ppp->pass_filter = NULL;
2540 kfree(ppp->active_filter);
2541 ppp->active_filter = NULL;
2542 #endif /* CONFIG_PPP_FILTER */
2543
2544 if (ppp->xmit_pending)
2545 kfree_skb(ppp->xmit_pending);
2546
2547 kfree(ppp);
2548 }
2549
2550 /*
2551 * Locate an existing ppp unit.
2552 * The caller should have locked the all_ppp_mutex.
2553 */
2554 static struct ppp *
2555 ppp_find_unit(int unit)
2556 {
2557 return cardmap_get(all_ppp_units, unit);
2558 }
2559
2560 /*
2561 * Locate an existing ppp channel.
2562 * The caller should have locked the all_channels_lock.
2563 * First we look in the new_channels list, then in the
2564 * all_channels list. If found in the new_channels list,
2565 * we move it to the all_channels list. This is for speed
2566 * when we have a lot of channels in use.
2567 */
2568 static struct channel *
2569 ppp_find_channel(int unit)
2570 {
2571 struct channel *pch;
2572
2573 list_for_each_entry(pch, &new_channels, list) {
2574 if (pch->file.index == unit) {
2575 list_move(&pch->list, &all_channels);
2576 return pch;
2577 }
2578 }
2579 list_for_each_entry(pch, &all_channels, list) {
2580 if (pch->file.index == unit)
2581 return pch;
2582 }
2583 return NULL;
2584 }
2585
2586 /*
2587 * Connect a PPP channel to a PPP interface unit.
2588 */
2589 static int
2590 ppp_connect_channel(struct channel *pch, int unit)
2591 {
2592 struct ppp *ppp;
2593 int ret = -ENXIO;
2594 int hdrlen;
2595
2596 mutex_lock(&all_ppp_mutex);
2597 ppp = ppp_find_unit(unit);
2598 if (!ppp)
2599 goto out;
2600 write_lock_bh(&pch->upl);
2601 ret = -EINVAL;
2602 if (pch->ppp)
2603 goto outl;
2604
2605 ppp_lock(ppp);
2606 if (pch->file.hdrlen > ppp->file.hdrlen)
2607 ppp->file.hdrlen = pch->file.hdrlen;
2608 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2609 if (ppp->dev && hdrlen > ppp->dev->hard_header_len)
2610 ppp->dev->hard_header_len = hdrlen;
2611 list_add_tail(&pch->clist, &ppp->channels);
2612 ++ppp->n_channels;
2613 pch->ppp = ppp;
2614 atomic_inc(&ppp->file.refcnt);
2615 ppp_unlock(ppp);
2616 ret = 0;
2617
2618 outl:
2619 write_unlock_bh(&pch->upl);
2620 out:
2621 mutex_unlock(&all_ppp_mutex);
2622 return ret;
2623 }
2624
2625 /*
2626 * Disconnect a channel from its ppp unit.
2627 */
2628 static int
2629 ppp_disconnect_channel(struct channel *pch)
2630 {
2631 struct ppp *ppp;
2632 int err = -EINVAL;
2633
2634 write_lock_bh(&pch->upl);
2635 ppp = pch->ppp;
2636 pch->ppp = NULL;
2637 write_unlock_bh(&pch->upl);
2638 if (ppp) {
2639 /* remove it from the ppp unit's list */
2640 ppp_lock(ppp);
2641 list_del(&pch->clist);
2642 if (--ppp->n_channels == 0)
2643 wake_up_interruptible(&ppp->file.rwait);
2644 ppp_unlock(ppp);
2645 if (atomic_dec_and_test(&ppp->file.refcnt))
2646 ppp_destroy_interface(ppp);
2647 err = 0;
2648 }
2649 return err;
2650 }
2651
2652 /*
2653 * Free up the resources used by a ppp channel.
2654 */
2655 static void ppp_destroy_channel(struct channel *pch)
2656 {
2657 atomic_dec(&channel_count);
2658
2659 if (!pch->file.dead) {
2660 /* "can't happen" */
2661 printk(KERN_ERR "ppp: destroying undead channel %p !\n",
2662 pch);
2663 return;
2664 }
2665 skb_queue_purge(&pch->file.xq);
2666 skb_queue_purge(&pch->file.rq);
2667 kfree(pch);
2668 }
2669
2670 static void __exit ppp_cleanup(void)
2671 {
2672 /* should never happen */
2673 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2674 printk(KERN_ERR "PPP: removing module but units remain!\n");
2675 cardmap_destroy(&all_ppp_units);
2676 unregister_chrdev(PPP_MAJOR, "ppp");
2677 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
2678 class_destroy(ppp_class);
2679 }
2680
2681 /*
2682 * Cardmap implementation.
2683 */
2684 static void *cardmap_get(struct cardmap *map, unsigned int nr)
2685 {
2686 struct cardmap *p;
2687 int i;
2688
2689 for (p = map; p != NULL; ) {
2690 if ((i = nr >> p->shift) >= CARDMAP_WIDTH)
2691 return NULL;
2692 if (p->shift == 0)
2693 return p->ptr[i];
2694 nr &= ~(CARDMAP_MASK << p->shift);
2695 p = p->ptr[i];
2696 }
2697 return NULL;
2698 }
2699
2700 static int cardmap_set(struct cardmap **pmap, unsigned int nr, void *ptr)
2701 {
2702 struct cardmap *p;
2703 int i;
2704
2705 p = *pmap;
2706 if (p == NULL || (nr >> p->shift) >= CARDMAP_WIDTH) {
2707 do {
2708 /* need a new top level */
2709 struct cardmap *np = kzalloc(sizeof(*np), GFP_KERNEL);
2710 if (!np)
2711 goto enomem;
2712 np->ptr[0] = p;
2713 if (p != NULL) {
2714 np->shift = p->shift + CARDMAP_ORDER;
2715 p->parent = np;
2716 } else
2717 np->shift = 0;
2718 p = np;
2719 } while ((nr >> p->shift) >= CARDMAP_WIDTH);
2720 *pmap = p;
2721 }
2722 while (p->shift > 0) {
2723 i = (nr >> p->shift) & CARDMAP_MASK;
2724 if (p->ptr[i] == NULL) {
2725 struct cardmap *np = kzalloc(sizeof(*np), GFP_KERNEL);
2726 if (!np)
2727 goto enomem;
2728 np->shift = p->shift - CARDMAP_ORDER;
2729 np->parent = p;
2730 p->ptr[i] = np;
2731 }
2732 if (ptr == NULL)
2733 clear_bit(i, &p->inuse);
2734 p = p->ptr[i];
2735 }
2736 i = nr & CARDMAP_MASK;
2737 p->ptr[i] = ptr;
2738 if (ptr != NULL)
2739 set_bit(i, &p->inuse);
2740 else
2741 clear_bit(i, &p->inuse);
2742 return 0;
2743 enomem:
2744 return -ENOMEM;
2745 }
2746
2747 static unsigned int cardmap_find_first_free(struct cardmap *map)
2748 {
2749 struct cardmap *p;
2750 unsigned int nr = 0;
2751 int i;
2752
2753 if ((p = map) == NULL)
2754 return 0;
2755 for (;;) {
2756 i = find_first_zero_bit(&p->inuse, CARDMAP_WIDTH);
2757 if (i >= CARDMAP_WIDTH) {
2758 if (p->parent == NULL)
2759 return CARDMAP_WIDTH << p->shift;
2760 p = p->parent;
2761 i = (nr >> p->shift) & CARDMAP_MASK;
2762 set_bit(i, &p->inuse);
2763 continue;
2764 }
2765 nr = (nr & (~CARDMAP_MASK << p->shift)) | (i << p->shift);
2766 if (p->shift == 0 || p->ptr[i] == NULL)
2767 return nr;
2768 p = p->ptr[i];
2769 }
2770 }
2771
2772 static void cardmap_destroy(struct cardmap **pmap)
2773 {
2774 struct cardmap *p, *np;
2775 int i;
2776
2777 for (p = *pmap; p != NULL; p = np) {
2778 if (p->shift != 0) {
2779 for (i = 0; i < CARDMAP_WIDTH; ++i)
2780 if (p->ptr[i] != NULL)
2781 break;
2782 if (i < CARDMAP_WIDTH) {
2783 np = p->ptr[i];
2784 p->ptr[i] = NULL;
2785 continue;
2786 }
2787 }
2788 np = p->parent;
2789 kfree(p);
2790 }
2791 *pmap = NULL;
2792 }
2793
2794 /* Module/initialization stuff */
2795
2796 module_init(ppp_init);
2797 module_exit(ppp_cleanup);
2798
2799 EXPORT_SYMBOL(ppp_register_channel);
2800 EXPORT_SYMBOL(ppp_unregister_channel);
2801 EXPORT_SYMBOL(ppp_channel_index);
2802 EXPORT_SYMBOL(ppp_unit_number);
2803 EXPORT_SYMBOL(ppp_input);
2804 EXPORT_SYMBOL(ppp_input_error);
2805 EXPORT_SYMBOL(ppp_output_wakeup);
2806 EXPORT_SYMBOL(ppp_register_compressor);
2807 EXPORT_SYMBOL(ppp_unregister_compressor);
2808 MODULE_LICENSE("GPL");
2809 MODULE_ALIAS_CHARDEV_MAJOR(PPP_MAJOR);
2810 MODULE_ALIAS("/dev/ppp");
kmemtrace - Kernel memory tracer