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ACPICA: Add support to externally execute _OSI method
[linux-2.6/mini2440.git] / drivers / net / ppp_generic.c
blob714a23035de1980a968c19a835712d587c007c17
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/smp_lock.h>
43 #include <linux/spinlock.h>
44 #include <linux/rwsem.h>
45 #include <linux/stddef.h>
46 #include <linux/device.h>
47 #include <linux/mutex.h>
48 #include <net/slhc_vj.h>
49 #include <asm/atomic.h>
50
51 #define PPP_VERSION "2.4.2"
52
53 /*
54 * Network protocols we support.
55 */
56 #define NP_IP 0 /* Internet Protocol V4 */
57 #define NP_IPV6 1 /* Internet Protocol V6 */
58 #define NP_IPX 2 /* IPX protocol */
59 #define NP_AT 3 /* Appletalk protocol */
60 #define NP_MPLS_UC 4 /* MPLS unicast */
61 #define NP_MPLS_MC 5 /* MPLS multicast */
62 #define NUM_NP 6 /* Number of NPs. */
63
64 #define MPHDRLEN 6 /* multilink protocol header length */
65 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */
66 #define MIN_FRAG_SIZE 64
67
68 /*
69 * An instance of /dev/ppp can be associated with either a ppp
70 * interface unit or a ppp channel. In both cases, file->private_data
71 * points to one of these.
72 */
73 struct ppp_file {
74 enum {
75 INTERFACE=1, CHANNEL
76 } kind;
77 struct sk_buff_head xq; /* pppd transmit queue */
78 struct sk_buff_head rq; /* receive queue for pppd */
79 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */
80 atomic_t refcnt; /* # refs (incl /dev/ppp attached) */
81 int hdrlen; /* space to leave for headers */
82 int index; /* interface unit / channel number */
83 int dead; /* unit/channel has been shut down */
84 };
85
86 #define PF_TO_X(pf, X) container_of(pf, X, file)
87
88 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
89 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
90
91 /*
92 * Data structure describing one ppp unit.
93 * A ppp unit corresponds to a ppp network interface device
94 * and represents a multilink bundle.
95 * It can have 0 or more ppp channels connected to it.
96 */
97 struct ppp {
98 struct ppp_file file; /* stuff for read/write/poll 0 */
99 struct file *owner; /* file that owns this unit 48 */
100 struct list_head channels; /* list of attached channels 4c */
101 int n_channels; /* how many channels are attached 54 */
102 spinlock_t rlock; /* lock for receive side 58 */
103 spinlock_t wlock; /* lock for transmit side 5c */
104 int mru; /* max receive unit 60 */
105 unsigned int flags; /* control bits 64 */
106 unsigned int xstate; /* transmit state bits 68 */
107 unsigned int rstate; /* receive state bits 6c */
108 int debug; /* debug flags 70 */
109 struct slcompress *vj; /* state for VJ header compression */
110 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
111 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
112 struct compressor *xcomp; /* transmit packet compressor 8c */
113 void *xc_state; /* its internal state 90 */
114 struct compressor *rcomp; /* receive decompressor 94 */
115 void *rc_state; /* its internal state 98 */
116 unsigned long last_xmit; /* jiffies when last pkt sent 9c */
117 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
118 struct net_device *dev; /* network interface device a4 */
119 int closing; /* is device closing down? a8 */
120 #ifdef CONFIG_PPP_MULTILINK
121 int nxchan; /* next channel to send something on */
122 u32 nxseq; /* next sequence number to send */
123 int mrru; /* MP: max reconst. receive unit */
124 u32 nextseq; /* MP: seq no of next packet */
125 u32 minseq; /* MP: min of most recent seqnos */
126 struct sk_buff_head mrq; /* MP: receive reconstruction queue */
127 #endif /* CONFIG_PPP_MULTILINK */
128 #ifdef CONFIG_PPP_FILTER
129 struct sock_filter *pass_filter; /* filter for packets to pass */
130 struct sock_filter *active_filter;/* filter for pkts to reset idle */
131 unsigned pass_len, active_len;
132 #endif /* CONFIG_PPP_FILTER */
133 };
134
135 /*
136 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
137 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
138 * SC_MUST_COMP
139 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
140 * Bits in xstate: SC_COMP_RUN
141 */
142 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
143 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
144 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
145
146 /*
147 * Private data structure for each channel.
148 * This includes the data structure used for multilink.
149 */
150 struct channel {
151 struct ppp_file file; /* stuff for read/write/poll */
152 struct list_head list; /* link in all/new_channels list */
153 struct ppp_channel *chan; /* public channel data structure */
154 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
155 spinlock_t downl; /* protects `chan', file.xq dequeue */
156 struct ppp *ppp; /* ppp unit we're connected to */
157 struct list_head clist; /* link in list of channels per unit */
158 rwlock_t upl; /* protects `ppp' */
159 #ifdef CONFIG_PPP_MULTILINK
160 u8 avail; /* flag used in multilink stuff */
161 u8 had_frag; /* >= 1 fragments have been sent */
162 u32 lastseq; /* MP: last sequence # received */
163 #endif /* CONFIG_PPP_MULTILINK */
164 };
165
166 /*
167 * SMP locking issues:
168 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
169 * list and the ppp.n_channels field, you need to take both locks
170 * before you modify them.
171 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
172 * channel.downl.
173 */
174
175 /*
176 * A cardmap represents a mapping from unsigned integers to pointers,
177 * and provides a fast "find lowest unused number" operation.
178 * It uses a broad (32-way) tree with a bitmap at each level.
179 * It is designed to be space-efficient for small numbers of entries
180 * and time-efficient for large numbers of entries.
181 */
182 #define CARDMAP_ORDER 5
183 #define CARDMAP_WIDTH (1U << CARDMAP_ORDER)
184 #define CARDMAP_MASK (CARDMAP_WIDTH - 1)
185
186 struct cardmap {
187 int shift;
188 unsigned long inuse;
189 struct cardmap *parent;
190 void *ptr[CARDMAP_WIDTH];
191 };
192 static void *cardmap_get(struct cardmap *map, unsigned int nr);
193 static int cardmap_set(struct cardmap **map, unsigned int nr, void *ptr);
194 static unsigned int cardmap_find_first_free(struct cardmap *map);
195 static void cardmap_destroy(struct cardmap **map);
196
197 /*
198 * all_ppp_mutex protects the all_ppp_units mapping.
199 * It also ensures that finding a ppp unit in the all_ppp_units map
200 * and updating its file.refcnt field is atomic.
201 */
202 static DEFINE_MUTEX(all_ppp_mutex);
203 static struct cardmap *all_ppp_units;
204 static atomic_t ppp_unit_count = ATOMIC_INIT(0);
205
206 /*
207 * all_channels_lock protects all_channels and last_channel_index,
208 * and the atomicity of find a channel and updating its file.refcnt
209 * field.
210 */
211 static DEFINE_SPINLOCK(all_channels_lock);
212 static LIST_HEAD(all_channels);
213 static LIST_HEAD(new_channels);
214 static int last_channel_index;
215 static atomic_t channel_count = ATOMIC_INIT(0);
216
217 /* Get the PPP protocol number from a skb */
218 #define PPP_PROTO(skb) (((skb)->data[0] << 8) + (skb)->data[1])
219
220 /* We limit the length of ppp->file.rq to this (arbitrary) value */
221 #define PPP_MAX_RQLEN 32
222
223 /*
224 * Maximum number of multilink fragments queued up.
225 * This has to be large enough to cope with the maximum latency of
226 * the slowest channel relative to the others. Strictly it should
227 * depend on the number of channels and their characteristics.
228 */
229 #define PPP_MP_MAX_QLEN 128
230
231 /* Multilink header bits. */
232 #define B 0x80 /* this fragment begins a packet */
233 #define E 0x40 /* this fragment ends a packet */
234
235 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */
236 #define seq_before(a, b) ((s32)((a) - (b)) < 0)
237 #define seq_after(a, b) ((s32)((a) - (b)) > 0)
238
239 /* Prototypes. */
240 static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file,
241 unsigned int cmd, unsigned long arg);
242 static void ppp_xmit_process(struct ppp *ppp);
243 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
244 static void ppp_push(struct ppp *ppp);
245 static void ppp_channel_push(struct channel *pch);
246 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
247 struct channel *pch);
248 static void ppp_receive_error(struct ppp *ppp);
249 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
250 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
251 struct sk_buff *skb);
252 #ifdef CONFIG_PPP_MULTILINK
253 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
254 struct channel *pch);
255 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
256 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
257 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
258 #endif /* CONFIG_PPP_MULTILINK */
259 static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
260 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
261 static void ppp_ccp_closed(struct ppp *ppp);
262 static struct compressor *find_compressor(int type);
263 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
264 static struct ppp *ppp_create_interface(int unit, int *retp);
265 static void init_ppp_file(struct ppp_file *pf, int kind);
266 static void ppp_shutdown_interface(struct ppp *ppp);
267 static void ppp_destroy_interface(struct ppp *ppp);
268 static struct ppp *ppp_find_unit(int unit);
269 static struct channel *ppp_find_channel(int unit);
270 static int ppp_connect_channel(struct channel *pch, int unit);
271 static int ppp_disconnect_channel(struct channel *pch);
272 static void ppp_destroy_channel(struct channel *pch);
273
274 static struct class *ppp_class;
275
276 /* Translates a PPP protocol number to a NP index (NP == network protocol) */
277 static inline int proto_to_npindex(int proto)
278 {
279 switch (proto) {
280 case PPP_IP:
281 return NP_IP;
282 case PPP_IPV6:
283 return NP_IPV6;
284 case PPP_IPX:
285 return NP_IPX;
286 case PPP_AT:
287 return NP_AT;
288 case PPP_MPLS_UC:
289 return NP_MPLS_UC;
290 case PPP_MPLS_MC:
291 return NP_MPLS_MC;
292 }
293 return -EINVAL;
294 }
295
296 /* Translates an NP index into a PPP protocol number */
297 static const int npindex_to_proto[NUM_NP] = {
298 PPP_IP,
299 PPP_IPV6,
300 PPP_IPX,
301 PPP_AT,
302 PPP_MPLS_UC,
303 PPP_MPLS_MC,
304 };
305
306 /* Translates an ethertype into an NP index */
307 static inline int ethertype_to_npindex(int ethertype)
308 {
309 switch (ethertype) {
310 case ETH_P_IP:
311 return NP_IP;
312 case ETH_P_IPV6:
313 return NP_IPV6;
314 case ETH_P_IPX:
315 return NP_IPX;
316 case ETH_P_PPPTALK:
317 case ETH_P_ATALK:
318 return NP_AT;
319 case ETH_P_MPLS_UC:
320 return NP_MPLS_UC;
321 case ETH_P_MPLS_MC:
322 return NP_MPLS_MC;
323 }
324 return -1;
325 }
326
327 /* Translates an NP index into an ethertype */
328 static const int npindex_to_ethertype[NUM_NP] = {
329 ETH_P_IP,
330 ETH_P_IPV6,
331 ETH_P_IPX,
332 ETH_P_PPPTALK,
333 ETH_P_MPLS_UC,
334 ETH_P_MPLS_MC,
335 };
336
337 /*
338 * Locking shorthand.
339 */
340 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
341 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
342 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
343 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
344 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
345 ppp_recv_lock(ppp); } while (0)
346 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
347 ppp_xmit_unlock(ppp); } while (0)
348
349 /*
350 * /dev/ppp device routines.
351 * The /dev/ppp device is used by pppd to control the ppp unit.
352 * It supports the read, write, ioctl and poll functions.
353 * Open instances of /dev/ppp can be in one of three states:
354 * unattached, attached to a ppp unit, or attached to a ppp channel.
355 */
356 static int ppp_open(struct inode *inode, struct file *file)
357 {
358 cycle_kernel_lock();
359 /*
360 * This could (should?) be enforced by the permissions on /dev/ppp.
361 */
362 if (!capable(CAP_NET_ADMIN))
363 return -EPERM;
364 return 0;
365 }
366
367 static int ppp_release(struct inode *unused, struct file *file)
368 {
369 struct ppp_file *pf = file->private_data;
370 struct ppp *ppp;
371
372 if (pf) {
373 file->private_data = NULL;
374 if (pf->kind == INTERFACE) {
375 ppp = PF_TO_PPP(pf);
376 if (file == ppp->owner)
377 ppp_shutdown_interface(ppp);
378 }
379 if (atomic_dec_and_test(&pf->refcnt)) {
380 switch (pf->kind) {
381 case INTERFACE:
382 ppp_destroy_interface(PF_TO_PPP(pf));
383 break;
384 case CHANNEL:
385 ppp_destroy_channel(PF_TO_CHANNEL(pf));
386 break;
387 }
388 }
389 }
390 return 0;
391 }
392
393 static ssize_t ppp_read(struct file *file, char __user *buf,
394 size_t count, loff_t *ppos)
395 {
396 struct ppp_file *pf = file->private_data;
397 DECLARE_WAITQUEUE(wait, current);
398 ssize_t ret;
399 struct sk_buff *skb = NULL;
400
401 ret = count;
402
403 if (!pf)
404 return -ENXIO;
405 add_wait_queue(&pf->rwait, &wait);
406 for (;;) {
407 set_current_state(TASK_INTERRUPTIBLE);
408 skb = skb_dequeue(&pf->rq);
409 if (skb)
410 break;
411 ret = 0;
412 if (pf->dead)
413 break;
414 if (pf->kind == INTERFACE) {
415 /*
416 * Return 0 (EOF) on an interface that has no
417 * channels connected, unless it is looping
418 * network traffic (demand mode).
419 */
420 struct ppp *ppp = PF_TO_PPP(pf);
421 if (ppp->n_channels == 0
422 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
423 break;
424 }
425 ret = -EAGAIN;
426 if (file->f_flags & O_NONBLOCK)
427 break;
428 ret = -ERESTARTSYS;
429 if (signal_pending(current))
430 break;
431 schedule();
432 }
433 set_current_state(TASK_RUNNING);
434 remove_wait_queue(&pf->rwait, &wait);
435
436 if (!skb)
437 goto out;
438
439 ret = -EOVERFLOW;
440 if (skb->len > count)
441 goto outf;
442 ret = -EFAULT;
443 if (copy_to_user(buf, skb->data, skb->len))
444 goto outf;
445 ret = skb->len;
446
447 outf:
448 kfree_skb(skb);
449 out:
450 return ret;
451 }
452
453 static ssize_t ppp_write(struct file *file, const char __user *buf,
454 size_t count, loff_t *ppos)
455 {
456 struct ppp_file *pf = file->private_data;
457 struct sk_buff *skb;
458 ssize_t ret;
459
460 if (!pf)
461 return -ENXIO;
462 ret = -ENOMEM;
463 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
464 if (!skb)
465 goto out;
466 skb_reserve(skb, pf->hdrlen);
467 ret = -EFAULT;
468 if (copy_from_user(skb_put(skb, count), buf, count)) {
469 kfree_skb(skb);
470 goto out;
471 }
472
473 skb_queue_tail(&pf->xq, skb);
474
475 switch (pf->kind) {
476 case INTERFACE:
477 ppp_xmit_process(PF_TO_PPP(pf));
478 break;
479 case CHANNEL:
480 ppp_channel_push(PF_TO_CHANNEL(pf));
481 break;
482 }
483
484 ret = count;
485
486 out:
487 return ret;
488 }
489
490 /* No kernel lock - fine */
491 static unsigned int ppp_poll(struct file *file, poll_table *wait)
492 {
493 struct ppp_file *pf = file->private_data;
494 unsigned int mask;
495
496 if (!pf)
497 return 0;
498 poll_wait(file, &pf->rwait, wait);
499 mask = POLLOUT | POLLWRNORM;
500 if (skb_peek(&pf->rq))
501 mask |= POLLIN | POLLRDNORM;
502 if (pf->dead)
503 mask |= POLLHUP;
504 else if (pf->kind == INTERFACE) {
505 /* see comment in ppp_read */
506 struct ppp *ppp = PF_TO_PPP(pf);
507 if (ppp->n_channels == 0
508 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
509 mask |= POLLIN | POLLRDNORM;
510 }
511
512 return mask;
513 }
514
515 #ifdef CONFIG_PPP_FILTER
516 static int get_filter(void __user *arg, struct sock_filter **p)
517 {
518 struct sock_fprog uprog;
519 struct sock_filter *code = NULL;
520 int len, err;
521
522 if (copy_from_user(&uprog, arg, sizeof(uprog)))
523 return -EFAULT;
524
525 if (!uprog.len) {
526 *p = NULL;
527 return 0;
528 }
529
530 len = uprog.len * sizeof(struct sock_filter);
531 code = kmalloc(len, GFP_KERNEL);
532 if (code == NULL)
533 return -ENOMEM;
534
535 if (copy_from_user(code, uprog.filter, len)) {
536 kfree(code);
537 return -EFAULT;
538 }
539
540 err = sk_chk_filter(code, uprog.len);
541 if (err) {
542 kfree(code);
543 return err;
544 }
545
546 *p = code;
547 return uprog.len;
548 }
549 #endif /* CONFIG_PPP_FILTER */
550
551 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
552 {
553 struct ppp_file *pf = file->private_data;
554 struct ppp *ppp;
555 int err = -EFAULT, val, val2, i;
556 struct ppp_idle idle;
557 struct npioctl npi;
558 int unit, cflags;
559 struct slcompress *vj;
560 void __user *argp = (void __user *)arg;
561 int __user *p = argp;
562
563 if (!pf)
564 return ppp_unattached_ioctl(pf, file, cmd, arg);
565
566 if (cmd == PPPIOCDETACH) {
567 /*
568 * We have to be careful here... if the file descriptor
569 * has been dup'd, we could have another process in the
570 * middle of a poll using the same file *, so we had
571 * better not free the interface data structures -
572 * instead we fail the ioctl. Even in this case, we
573 * shut down the interface if we are the owner of it.
574 * Actually, we should get rid of PPPIOCDETACH, userland
575 * (i.e. pppd) could achieve the same effect by closing
576 * this fd and reopening /dev/ppp.
577 */
578 err = -EINVAL;
579 lock_kernel();
580 if (pf->kind == INTERFACE) {
581 ppp = PF_TO_PPP(pf);
582 if (file == ppp->owner)
583 ppp_shutdown_interface(ppp);
584 }
585 if (atomic_long_read(&file->f_count) <= 2) {
586 ppp_release(NULL, file);
587 err = 0;
588 } else
589 printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%ld\n",
590 atomic_long_read(&file->f_count));
591 unlock_kernel();
592 return err;
593 }
594
595 if (pf->kind == CHANNEL) {
596 struct channel *pch;
597 struct ppp_channel *chan;
598
599 lock_kernel();
600 pch = PF_TO_CHANNEL(pf);
601
602 switch (cmd) {
603 case PPPIOCCONNECT:
604 if (get_user(unit, p))
605 break;
606 err = ppp_connect_channel(pch, unit);
607 break;
608
609 case PPPIOCDISCONN:
610 err = ppp_disconnect_channel(pch);
611 break;
612
613 default:
614 down_read(&pch->chan_sem);
615 chan = pch->chan;
616 err = -ENOTTY;
617 if (chan && chan->ops->ioctl)
618 err = chan->ops->ioctl(chan, cmd, arg);
619 up_read(&pch->chan_sem);
620 }
621 unlock_kernel();
622 return err;
623 }
624
625 if (pf->kind != INTERFACE) {
626 /* can't happen */
627 printk(KERN_ERR "PPP: not interface or channel??\n");
628 return -EINVAL;
629 }
630
631 lock_kernel();
632 ppp = PF_TO_PPP(pf);
633 switch (cmd) {
634 case PPPIOCSMRU:
635 if (get_user(val, p))
636 break;
637 ppp->mru = val;
638 err = 0;
639 break;
640
641 case PPPIOCSFLAGS:
642 if (get_user(val, p))
643 break;
644 ppp_lock(ppp);
645 cflags = ppp->flags & ~val;
646 ppp->flags = val & SC_FLAG_BITS;
647 ppp_unlock(ppp);
648 if (cflags & SC_CCP_OPEN)
649 ppp_ccp_closed(ppp);
650 err = 0;
651 break;
652
653 case PPPIOCGFLAGS:
654 val = ppp->flags | ppp->xstate | ppp->rstate;
655 if (put_user(val, p))
656 break;
657 err = 0;
658 break;
659
660 case PPPIOCSCOMPRESS:
661 err = ppp_set_compress(ppp, arg);
662 break;
663
664 case PPPIOCGUNIT:
665 if (put_user(ppp->file.index, p))
666 break;
667 err = 0;
668 break;
669
670 case PPPIOCSDEBUG:
671 if (get_user(val, p))
672 break;
673 ppp->debug = val;
674 err = 0;
675 break;
676
677 case PPPIOCGDEBUG:
678 if (put_user(ppp->debug, p))
679 break;
680 err = 0;
681 break;
682
683 case PPPIOCGIDLE:
684 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
685 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
686 if (copy_to_user(argp, &idle, sizeof(idle)))
687 break;
688 err = 0;
689 break;
690
691 case PPPIOCSMAXCID:
692 if (get_user(val, p))
693 break;
694 val2 = 15;
695 if ((val >> 16) != 0) {
696 val2 = val >> 16;
697 val &= 0xffff;
698 }
699 vj = slhc_init(val2+1, val+1);
700 if (!vj) {
701 printk(KERN_ERR "PPP: no memory (VJ compressor)\n");
702 err = -ENOMEM;
703 break;
704 }
705 ppp_lock(ppp);
706 if (ppp->vj)
707 slhc_free(ppp->vj);
708 ppp->vj = vj;
709 ppp_unlock(ppp);
710 err = 0;
711 break;
712
713 case PPPIOCGNPMODE:
714 case PPPIOCSNPMODE:
715 if (copy_from_user(&npi, argp, sizeof(npi)))
716 break;
717 err = proto_to_npindex(npi.protocol);
718 if (err < 0)
719 break;
720 i = err;
721 if (cmd == PPPIOCGNPMODE) {
722 err = -EFAULT;
723 npi.mode = ppp->npmode[i];
724 if (copy_to_user(argp, &npi, sizeof(npi)))
725 break;
726 } else {
727 ppp->npmode[i] = npi.mode;
728 /* we may be able to transmit more packets now (??) */
729 netif_wake_queue(ppp->dev);
730 }
731 err = 0;
732 break;
733
734 #ifdef CONFIG_PPP_FILTER
735 case PPPIOCSPASS:
736 {
737 struct sock_filter *code;
738 err = get_filter(argp, &code);
739 if (err >= 0) {
740 ppp_lock(ppp);
741 kfree(ppp->pass_filter);
742 ppp->pass_filter = code;
743 ppp->pass_len = err;
744 ppp_unlock(ppp);
745 err = 0;
746 }
747 break;
748 }
749 case PPPIOCSACTIVE:
750 {
751 struct sock_filter *code;
752 err = get_filter(argp, &code);
753 if (err >= 0) {
754 ppp_lock(ppp);
755 kfree(ppp->active_filter);
756 ppp->active_filter = code;
757 ppp->active_len = err;
758 ppp_unlock(ppp);
759 err = 0;
760 }
761 break;
762 }
763 #endif /* CONFIG_PPP_FILTER */
764
765 #ifdef CONFIG_PPP_MULTILINK
766 case PPPIOCSMRRU:
767 if (get_user(val, p))
768 break;
769 ppp_recv_lock(ppp);
770 ppp->mrru = val;
771 ppp_recv_unlock(ppp);
772 err = 0;
773 break;
774 #endif /* CONFIG_PPP_MULTILINK */
775
776 default:
777 err = -ENOTTY;
778 }
779 unlock_kernel();
780 return err;
781 }
782
783 static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file,
784 unsigned int cmd, unsigned long arg)
785 {
786 int unit, err = -EFAULT;
787 struct ppp *ppp;
788 struct channel *chan;
789 int __user *p = (int __user *)arg;
790
791 lock_kernel();
792 switch (cmd) {
793 case PPPIOCNEWUNIT:
794 /* Create a new ppp unit */
795 if (get_user(unit, p))
796 break;
797 ppp = ppp_create_interface(unit, &err);
798 if (!ppp)
799 break;
800 file->private_data = &ppp->file;
801 ppp->owner = file;
802 err = -EFAULT;
803 if (put_user(ppp->file.index, p))
804 break;
805 err = 0;
806 break;
807
808 case PPPIOCATTACH:
809 /* Attach to an existing ppp unit */
810 if (get_user(unit, p))
811 break;
812 mutex_lock(&all_ppp_mutex);
813 err = -ENXIO;
814 ppp = ppp_find_unit(unit);
815 if (ppp) {
816 atomic_inc(&ppp->file.refcnt);
817 file->private_data = &ppp->file;
818 err = 0;
819 }
820 mutex_unlock(&all_ppp_mutex);
821 break;
822
823 case PPPIOCATTCHAN:
824 if (get_user(unit, p))
825 break;
826 spin_lock_bh(&all_channels_lock);
827 err = -ENXIO;
828 chan = ppp_find_channel(unit);
829 if (chan) {
830 atomic_inc(&chan->file.refcnt);
831 file->private_data = &chan->file;
832 err = 0;
833 }
834 spin_unlock_bh(&all_channels_lock);
835 break;
836
837 default:
838 err = -ENOTTY;
839 }
840 unlock_kernel();
841 return err;
842 }
843
844 static const struct file_operations ppp_device_fops = {
845 .owner = THIS_MODULE,
846 .read = ppp_read,
847 .write = ppp_write,
848 .poll = ppp_poll,
849 .unlocked_ioctl = ppp_ioctl,
850 .open = ppp_open,
851 .release = ppp_release
852 };
853
854 #define PPP_MAJOR 108
855
856 /* Called at boot time if ppp is compiled into the kernel,
857 or at module load time (from init_module) if compiled as a module. */
858 static int __init ppp_init(void)
859 {
860 int err;
861
862 printk(KERN_INFO "PPP generic driver version " PPP_VERSION "\n");
863 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
864 if (!err) {
865 ppp_class = class_create(THIS_MODULE, "ppp");
866 if (IS_ERR(ppp_class)) {
867 err = PTR_ERR(ppp_class);
868 goto out_chrdev;
869 }
870 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL,
871 "ppp");
872 }
873
874 out:
875 if (err)
876 printk(KERN_ERR "failed to register PPP device (%d)\n", err);
877 return err;
878
879 out_chrdev:
880 unregister_chrdev(PPP_MAJOR, "ppp");
881 goto out;
882 }
883
884 /*
885 * Network interface unit routines.
886 */
887 static int
888 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
889 {
890 struct ppp *ppp = (struct ppp *) dev->priv;
891 int npi, proto;
892 unsigned char *pp;
893
894 npi = ethertype_to_npindex(ntohs(skb->protocol));
895 if (npi < 0)
896 goto outf;
897
898 /* Drop, accept or reject the packet */
899 switch (ppp->npmode[npi]) {
900 case NPMODE_PASS:
901 break;
902 case NPMODE_QUEUE:
903 /* it would be nice to have a way to tell the network
904 system to queue this one up for later. */
905 goto outf;
906 case NPMODE_DROP:
907 case NPMODE_ERROR:
908 goto outf;
909 }
910
911 /* Put the 2-byte PPP protocol number on the front,
912 making sure there is room for the address and control fields. */
913 if (skb_cow_head(skb, PPP_HDRLEN))
914 goto outf;
915
916 pp = skb_push(skb, 2);
917 proto = npindex_to_proto[npi];
918 pp[0] = proto >> 8;
919 pp[1] = proto;
920
921 netif_stop_queue(dev);
922 skb_queue_tail(&ppp->file.xq, skb);
923 ppp_xmit_process(ppp);
924 return 0;
925
926 outf:
927 kfree_skb(skb);
928 ++ppp->dev->stats.tx_dropped;
929 return 0;
930 }
931
932 static int
933 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
934 {
935 struct ppp *ppp = dev->priv;
936 int err = -EFAULT;
937 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
938 struct ppp_stats stats;
939 struct ppp_comp_stats cstats;
940 char *vers;
941
942 switch (cmd) {
943 case SIOCGPPPSTATS:
944 ppp_get_stats(ppp, &stats);
945 if (copy_to_user(addr, &stats, sizeof(stats)))
946 break;
947 err = 0;
948 break;
949
950 case SIOCGPPPCSTATS:
951 memset(&cstats, 0, sizeof(cstats));
952 if (ppp->xc_state)
953 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
954 if (ppp->rc_state)
955 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
956 if (copy_to_user(addr, &cstats, sizeof(cstats)))
957 break;
958 err = 0;
959 break;
960
961 case SIOCGPPPVER:
962 vers = PPP_VERSION;
963 if (copy_to_user(addr, vers, strlen(vers) + 1))
964 break;
965 err = 0;
966 break;
967
968 default:
969 err = -EINVAL;
970 }
971
972 return err;
973 }
974
975 static void ppp_setup(struct net_device *dev)
976 {
977 dev->hard_header_len = PPP_HDRLEN;
978 dev->mtu = PPP_MTU;
979 dev->addr_len = 0;
980 dev->tx_queue_len = 3;
981 dev->type = ARPHRD_PPP;
982 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
983 }
984
985 /*
986 * Transmit-side routines.
987 */
988
989 /*
990 * Called to do any work queued up on the transmit side
991 * that can now be done.
992 */
993 static void
994 ppp_xmit_process(struct ppp *ppp)
995 {
996 struct sk_buff *skb;
997
998 ppp_xmit_lock(ppp);
999 if (!ppp->closing) {
1000 ppp_push(ppp);
1001 while (!ppp->xmit_pending
1002 && (skb = skb_dequeue(&ppp->file.xq)))
1003 ppp_send_frame(ppp, skb);
1004 /* If there's no work left to do, tell the core net
1005 code that we can accept some more. */
1006 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1007 netif_wake_queue(ppp->dev);
1008 }
1009 ppp_xmit_unlock(ppp);
1010 }
1011
1012 static inline struct sk_buff *
1013 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1014 {
1015 struct sk_buff *new_skb;
1016 int len;
1017 int new_skb_size = ppp->dev->mtu +
1018 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1019 int compressor_skb_size = ppp->dev->mtu +
1020 ppp->xcomp->comp_extra + PPP_HDRLEN;
1021 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1022 if (!new_skb) {
1023 if (net_ratelimit())
1024 printk(KERN_ERR "PPP: no memory (comp pkt)\n");
1025 return NULL;
1026 }
1027 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1028 skb_reserve(new_skb,
1029 ppp->dev->hard_header_len - PPP_HDRLEN);
1030
1031 /* compressor still expects A/C bytes in hdr */
1032 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1033 new_skb->data, skb->len + 2,
1034 compressor_skb_size);
1035 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1036 kfree_skb(skb);
1037 skb = new_skb;
1038 skb_put(skb, len);
1039 skb_pull(skb, 2); /* pull off A/C bytes */
1040 } else if (len == 0) {
1041 /* didn't compress, or CCP not up yet */
1042 kfree_skb(new_skb);
1043 new_skb = skb;
1044 } else {
1045 /*
1046 * (len < 0)
1047 * MPPE requires that we do not send unencrypted
1048 * frames. The compressor will return -1 if we
1049 * should drop the frame. We cannot simply test
1050 * the compress_proto because MPPE and MPPC share
1051 * the same number.
1052 */
1053 if (net_ratelimit())
1054 printk(KERN_ERR "ppp: compressor dropped pkt\n");
1055 kfree_skb(skb);
1056 kfree_skb(new_skb);
1057 new_skb = NULL;
1058 }
1059 return new_skb;
1060 }
1061
1062 /*
1063 * Compress and send a frame.
1064 * The caller should have locked the xmit path,
1065 * and xmit_pending should be 0.
1066 */
1067 static void
1068 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1069 {
1070 int proto = PPP_PROTO(skb);
1071 struct sk_buff *new_skb;
1072 int len;
1073 unsigned char *cp;
1074
1075 if (proto < 0x8000) {
1076 #ifdef CONFIG_PPP_FILTER
1077 /* check if we should pass this packet */
1078 /* the filter instructions are constructed assuming
1079 a four-byte PPP header on each packet */
1080 *skb_push(skb, 2) = 1;
1081 if (ppp->pass_filter
1082 && sk_run_filter(skb, ppp->pass_filter,
1083 ppp->pass_len) == 0) {
1084 if (ppp->debug & 1)
1085 printk(KERN_DEBUG "PPP: outbound frame not passed\n");
1086 kfree_skb(skb);
1087 return;
1088 }
1089 /* if this packet passes the active filter, record the time */
1090 if (!(ppp->active_filter
1091 && sk_run_filter(skb, ppp->active_filter,
1092 ppp->active_len) == 0))
1093 ppp->last_xmit = jiffies;
1094 skb_pull(skb, 2);
1095 #else
1096 /* for data packets, record the time */
1097 ppp->last_xmit = jiffies;
1098 #endif /* CONFIG_PPP_FILTER */
1099 }
1100
1101 ++ppp->dev->stats.tx_packets;
1102 ppp->dev->stats.tx_bytes += skb->len - 2;
1103
1104 switch (proto) {
1105 case PPP_IP:
1106 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1107 break;
1108 /* try to do VJ TCP header compression */
1109 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1110 GFP_ATOMIC);
1111 if (!new_skb) {
1112 printk(KERN_ERR "PPP: no memory (VJ comp pkt)\n");
1113 goto drop;
1114 }
1115 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1116 cp = skb->data + 2;
1117 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1118 new_skb->data + 2, &cp,
1119 !(ppp->flags & SC_NO_TCP_CCID));
1120 if (cp == skb->data + 2) {
1121 /* didn't compress */
1122 kfree_skb(new_skb);
1123 } else {
1124 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1125 proto = PPP_VJC_COMP;
1126 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1127 } else {
1128 proto = PPP_VJC_UNCOMP;
1129 cp[0] = skb->data[2];
1130 }
1131 kfree_skb(skb);
1132 skb = new_skb;
1133 cp = skb_put(skb, len + 2);
1134 cp[0] = 0;
1135 cp[1] = proto;
1136 }
1137 break;
1138
1139 case PPP_CCP:
1140 /* peek at outbound CCP frames */
1141 ppp_ccp_peek(ppp, skb, 0);
1142 break;
1143 }
1144
1145 /* try to do packet compression */
1146 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state
1147 && proto != PPP_LCP && proto != PPP_CCP) {
1148 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1149 if (net_ratelimit())
1150 printk(KERN_ERR "ppp: compression required but down - pkt dropped.\n");
1151 goto drop;
1152 }
1153 skb = pad_compress_skb(ppp, skb);
1154 if (!skb)
1155 goto drop;
1156 }
1157
1158 /*
1159 * If we are waiting for traffic (demand dialling),
1160 * queue it up for pppd to receive.
1161 */
1162 if (ppp->flags & SC_LOOP_TRAFFIC) {
1163 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1164 goto drop;
1165 skb_queue_tail(&ppp->file.rq, skb);
1166 wake_up_interruptible(&ppp->file.rwait);
1167 return;
1168 }
1169
1170 ppp->xmit_pending = skb;
1171 ppp_push(ppp);
1172 return;
1173
1174 drop:
1175 if (skb)
1176 kfree_skb(skb);
1177 ++ppp->dev->stats.tx_errors;
1178 }
1179
1180 /*
1181 * Try to send the frame in xmit_pending.
1182 * The caller should have the xmit path locked.
1183 */
1184 static void
1185 ppp_push(struct ppp *ppp)
1186 {
1187 struct list_head *list;
1188 struct channel *pch;
1189 struct sk_buff *skb = ppp->xmit_pending;
1190
1191 if (!skb)
1192 return;
1193
1194 list = &ppp->channels;
1195 if (list_empty(list)) {
1196 /* nowhere to send the packet, just drop it */
1197 ppp->xmit_pending = NULL;
1198 kfree_skb(skb);
1199 return;
1200 }
1201
1202 if ((ppp->flags & SC_MULTILINK) == 0) {
1203 /* not doing multilink: send it down the first channel */
1204 list = list->next;
1205 pch = list_entry(list, struct channel, clist);
1206
1207 spin_lock_bh(&pch->downl);
1208 if (pch->chan) {
1209 if (pch->chan->ops->start_xmit(pch->chan, skb))
1210 ppp->xmit_pending = NULL;
1211 } else {
1212 /* channel got unregistered */
1213 kfree_skb(skb);
1214 ppp->xmit_pending = NULL;
1215 }
1216 spin_unlock_bh(&pch->downl);
1217 return;
1218 }
1219
1220 #ifdef CONFIG_PPP_MULTILINK
1221 /* Multilink: fragment the packet over as many links
1222 as can take the packet at the moment. */
1223 if (!ppp_mp_explode(ppp, skb))
1224 return;
1225 #endif /* CONFIG_PPP_MULTILINK */
1226
1227 ppp->xmit_pending = NULL;
1228 kfree_skb(skb);
1229 }
1230
1231 #ifdef CONFIG_PPP_MULTILINK
1232 /*
1233 * Divide a packet to be transmitted into fragments and
1234 * send them out the individual links.
1235 */
1236 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1237 {
1238 int len, fragsize;
1239 int i, bits, hdrlen, mtu;
1240 int flen;
1241 int navail, nfree;
1242 int nbigger;
1243 unsigned char *p, *q;
1244 struct list_head *list;
1245 struct channel *pch;
1246 struct sk_buff *frag;
1247 struct ppp_channel *chan;
1248
1249 nfree = 0; /* # channels which have no packet already queued */
1250 navail = 0; /* total # of usable channels (not deregistered) */
1251 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1252 i = 0;
1253 list_for_each_entry(pch, &ppp->channels, clist) {
1254 navail += pch->avail = (pch->chan != NULL);
1255 if (pch->avail) {
1256 if (skb_queue_empty(&pch->file.xq) ||
1257 !pch->had_frag) {
1258 pch->avail = 2;
1259 ++nfree;
1260 }
1261 if (!pch->had_frag && i < ppp->nxchan)
1262 ppp->nxchan = i;
1263 }
1264 ++i;
1265 }
1266
1267 /*
1268 * Don't start sending this packet unless at least half of
1269 * the channels are free. This gives much better TCP
1270 * performance if we have a lot of channels.
1271 */
1272 if (nfree == 0 || nfree < navail / 2)
1273 return 0; /* can't take now, leave it in xmit_pending */
1274
1275 /* Do protocol field compression (XXX this should be optional) */
1276 p = skb->data;
1277 len = skb->len;
1278 if (*p == 0) {
1279 ++p;
1280 --len;
1281 }
1282
1283 /*
1284 * Decide on fragment size.
1285 * We create a fragment for each free channel regardless of
1286 * how small they are (i.e. even 0 length) in order to minimize
1287 * the time that it will take to detect when a channel drops
1288 * a fragment.
1289 */
1290 fragsize = len;
1291 if (nfree > 1)
1292 fragsize = DIV_ROUND_UP(fragsize, nfree);
1293 /* nbigger channels get fragsize bytes, the rest get fragsize-1,
1294 except if nbigger==0, then they all get fragsize. */
1295 nbigger = len % nfree;
1296
1297 /* skip to the channel after the one we last used
1298 and start at that one */
1299 list = &ppp->channels;
1300 for (i = 0; i < ppp->nxchan; ++i) {
1301 list = list->next;
1302 if (list == &ppp->channels) {
1303 i = 0;
1304 break;
1305 }
1306 }
1307
1308 /* create a fragment for each channel */
1309 bits = B;
1310 while (nfree > 0 || len > 0) {
1311 list = list->next;
1312 if (list == &ppp->channels) {
1313 i = 0;
1314 continue;
1315 }
1316 pch = list_entry(list, struct channel, clist);
1317 ++i;
1318 if (!pch->avail)
1319 continue;
1320
1321 /*
1322 * Skip this channel if it has a fragment pending already and
1323 * we haven't given a fragment to all of the free channels.
1324 */
1325 if (pch->avail == 1) {
1326 if (nfree > 0)
1327 continue;
1328 } else {
1329 --nfree;
1330 pch->avail = 1;
1331 }
1332
1333 /* check the channel's mtu and whether it is still attached. */
1334 spin_lock_bh(&pch->downl);
1335 if (pch->chan == NULL) {
1336 /* can't use this channel, it's being deregistered */
1337 spin_unlock_bh(&pch->downl);
1338 pch->avail = 0;
1339 if (--navail == 0)
1340 break;
1341 continue;
1342 }
1343
1344 /*
1345 * Create a fragment for this channel of
1346 * min(max(mtu+2-hdrlen, 4), fragsize, len) bytes.
1347 * If mtu+2-hdrlen < 4, that is a ridiculously small
1348 * MTU, so we use mtu = 2 + hdrlen.
1349 */
1350 if (fragsize > len)
1351 fragsize = len;
1352 flen = fragsize;
1353 mtu = pch->chan->mtu + 2 - hdrlen;
1354 if (mtu < 4)
1355 mtu = 4;
1356 if (flen > mtu)
1357 flen = mtu;
1358 if (flen == len && nfree == 0)
1359 bits |= E;
1360 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1361 if (!frag)
1362 goto noskb;
1363 q = skb_put(frag, flen + hdrlen);
1364
1365 /* make the MP header */
1366 q[0] = PPP_MP >> 8;
1367 q[1] = PPP_MP;
1368 if (ppp->flags & SC_MP_XSHORTSEQ) {
1369 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1370 q[3] = ppp->nxseq;
1371 } else {
1372 q[2] = bits;
1373 q[3] = ppp->nxseq >> 16;
1374 q[4] = ppp->nxseq >> 8;
1375 q[5] = ppp->nxseq;
1376 }
1377
1378 /*
1379 * Copy the data in.
1380 * Unfortunately there is a bug in older versions of
1381 * the Linux PPP multilink reconstruction code where it
1382 * drops 0-length fragments. Therefore we make sure the
1383 * fragment has at least one byte of data. Any bytes
1384 * we add in this situation will end up as padding on the
1385 * end of the reconstructed packet.
1386 */
1387 if (flen == 0)
1388 *skb_put(frag, 1) = 0;
1389 else
1390 memcpy(q + hdrlen, p, flen);
1391
1392 /* try to send it down the channel */
1393 chan = pch->chan;
1394 if (!skb_queue_empty(&pch->file.xq) ||
1395 !chan->ops->start_xmit(chan, frag))
1396 skb_queue_tail(&pch->file.xq, frag);
1397 pch->had_frag = 1;
1398 p += flen;
1399 len -= flen;
1400 ++ppp->nxseq;
1401 bits = 0;
1402 spin_unlock_bh(&pch->downl);
1403
1404 if (--nbigger == 0 && fragsize > 0)
1405 --fragsize;
1406 }
1407 ppp->nxchan = i;
1408
1409 return 1;
1410
1411 noskb:
1412 spin_unlock_bh(&pch->downl);
1413 if (ppp->debug & 1)
1414 printk(KERN_ERR "PPP: no memory (fragment)\n");
1415 ++ppp->dev->stats.tx_errors;
1416 ++ppp->nxseq;
1417 return 1; /* abandon the frame */
1418 }
1419 #endif /* CONFIG_PPP_MULTILINK */
1420
1421 /*
1422 * Try to send data out on a channel.
1423 */
1424 static void
1425 ppp_channel_push(struct channel *pch)
1426 {
1427 struct sk_buff *skb;
1428 struct ppp *ppp;
1429
1430 spin_lock_bh(&pch->downl);
1431 if (pch->chan) {
1432 while (!skb_queue_empty(&pch->file.xq)) {
1433 skb = skb_dequeue(&pch->file.xq);
1434 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1435 /* put the packet back and try again later */
1436 skb_queue_head(&pch->file.xq, skb);
1437 break;
1438 }
1439 }
1440 } else {
1441 /* channel got deregistered */
1442 skb_queue_purge(&pch->file.xq);
1443 }
1444 spin_unlock_bh(&pch->downl);
1445 /* see if there is anything from the attached unit to be sent */
1446 if (skb_queue_empty(&pch->file.xq)) {
1447 read_lock_bh(&pch->upl);
1448 ppp = pch->ppp;
1449 if (ppp)
1450 ppp_xmit_process(ppp);
1451 read_unlock_bh(&pch->upl);
1452 }
1453 }
1454
1455 /*
1456 * Receive-side routines.
1457 */
1458
1459 /* misuse a few fields of the skb for MP reconstruction */
1460 #define sequence priority
1461 #define BEbits cb[0]
1462
1463 static inline void
1464 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1465 {
1466 ppp_recv_lock(ppp);
1467 if (!ppp->closing)
1468 ppp_receive_frame(ppp, skb, pch);
1469 else
1470 kfree_skb(skb);
1471 ppp_recv_unlock(ppp);
1472 }
1473
1474 void
1475 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1476 {
1477 struct channel *pch = chan->ppp;
1478 int proto;
1479
1480 if (!pch || skb->len == 0) {
1481 kfree_skb(skb);
1482 return;
1483 }
1484
1485 proto = PPP_PROTO(skb);
1486 read_lock_bh(&pch->upl);
1487 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1488 /* put it on the channel queue */
1489 skb_queue_tail(&pch->file.rq, skb);
1490 /* drop old frames if queue too long */
1491 while (pch->file.rq.qlen > PPP_MAX_RQLEN
1492 && (skb = skb_dequeue(&pch->file.rq)))
1493 kfree_skb(skb);
1494 wake_up_interruptible(&pch->file.rwait);
1495 } else {
1496 ppp_do_recv(pch->ppp, skb, pch);
1497 }
1498 read_unlock_bh(&pch->upl);
1499 }
1500
1501 /* Put a 0-length skb in the receive queue as an error indication */
1502 void
1503 ppp_input_error(struct ppp_channel *chan, int code)
1504 {
1505 struct channel *pch = chan->ppp;
1506 struct sk_buff *skb;
1507
1508 if (!pch)
1509 return;
1510
1511 read_lock_bh(&pch->upl);
1512 if (pch->ppp) {
1513 skb = alloc_skb(0, GFP_ATOMIC);
1514 if (skb) {
1515 skb->len = 0; /* probably unnecessary */
1516 skb->cb[0] = code;
1517 ppp_do_recv(pch->ppp, skb, pch);
1518 }
1519 }
1520 read_unlock_bh(&pch->upl);
1521 }
1522
1523 /*
1524 * We come in here to process a received frame.
1525 * The receive side of the ppp unit is locked.
1526 */
1527 static void
1528 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1529 {
1530 if (pskb_may_pull(skb, 2)) {
1531 #ifdef CONFIG_PPP_MULTILINK
1532 /* XXX do channel-level decompression here */
1533 if (PPP_PROTO(skb) == PPP_MP)
1534 ppp_receive_mp_frame(ppp, skb, pch);
1535 else
1536 #endif /* CONFIG_PPP_MULTILINK */
1537 ppp_receive_nonmp_frame(ppp, skb);
1538 return;
1539 }
1540
1541 if (skb->len > 0)
1542 /* note: a 0-length skb is used as an error indication */
1543 ++ppp->dev->stats.rx_length_errors;
1544
1545 kfree_skb(skb);
1546 ppp_receive_error(ppp);
1547 }
1548
1549 static void
1550 ppp_receive_error(struct ppp *ppp)
1551 {
1552 ++ppp->dev->stats.rx_errors;
1553 if (ppp->vj)
1554 slhc_toss(ppp->vj);
1555 }
1556
1557 static void
1558 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1559 {
1560 struct sk_buff *ns;
1561 int proto, len, npi;
1562
1563 /*
1564 * Decompress the frame, if compressed.
1565 * Note that some decompressors need to see uncompressed frames
1566 * that come in as well as compressed frames.
1567 */
1568 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)
1569 && (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1570 skb = ppp_decompress_frame(ppp, skb);
1571
1572 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1573 goto err;
1574
1575 proto = PPP_PROTO(skb);
1576 switch (proto) {
1577 case PPP_VJC_COMP:
1578 /* decompress VJ compressed packets */
1579 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1580 goto err;
1581
1582 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1583 /* copy to a new sk_buff with more tailroom */
1584 ns = dev_alloc_skb(skb->len + 128);
1585 if (!ns) {
1586 printk(KERN_ERR"PPP: no memory (VJ decomp)\n");
1587 goto err;
1588 }
1589 skb_reserve(ns, 2);
1590 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1591 kfree_skb(skb);
1592 skb = ns;
1593 }
1594 else
1595 skb->ip_summed = CHECKSUM_NONE;
1596
1597 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1598 if (len <= 0) {
1599 printk(KERN_DEBUG "PPP: VJ decompression error\n");
1600 goto err;
1601 }
1602 len += 2;
1603 if (len > skb->len)
1604 skb_put(skb, len - skb->len);
1605 else if (len < skb->len)
1606 skb_trim(skb, len);
1607 proto = PPP_IP;
1608 break;
1609
1610 case PPP_VJC_UNCOMP:
1611 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1612 goto err;
1613
1614 /* Until we fix the decompressor need to make sure
1615 * data portion is linear.
1616 */
1617 if (!pskb_may_pull(skb, skb->len))
1618 goto err;
1619
1620 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1621 printk(KERN_ERR "PPP: VJ uncompressed error\n");
1622 goto err;
1623 }
1624 proto = PPP_IP;
1625 break;
1626
1627 case PPP_CCP:
1628 ppp_ccp_peek(ppp, skb, 1);
1629 break;
1630 }
1631
1632 ++ppp->dev->stats.rx_packets;
1633 ppp->dev->stats.rx_bytes += skb->len - 2;
1634
1635 npi = proto_to_npindex(proto);
1636 if (npi < 0) {
1637 /* control or unknown frame - pass it to pppd */
1638 skb_queue_tail(&ppp->file.rq, skb);
1639 /* limit queue length by dropping old frames */
1640 while (ppp->file.rq.qlen > PPP_MAX_RQLEN
1641 && (skb = skb_dequeue(&ppp->file.rq)))
1642 kfree_skb(skb);
1643 /* wake up any process polling or blocking on read */
1644 wake_up_interruptible(&ppp->file.rwait);
1645
1646 } else {
1647 /* network protocol frame - give it to the kernel */
1648
1649 #ifdef CONFIG_PPP_FILTER
1650 /* check if the packet passes the pass and active filters */
1651 /* the filter instructions are constructed assuming
1652 a four-byte PPP header on each packet */
1653 if (ppp->pass_filter || ppp->active_filter) {
1654 if (skb_cloned(skb) &&
1655 pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
1656 goto err;
1657
1658 *skb_push(skb, 2) = 0;
1659 if (ppp->pass_filter
1660 && sk_run_filter(skb, ppp->pass_filter,
1661 ppp->pass_len) == 0) {
1662 if (ppp->debug & 1)
1663 printk(KERN_DEBUG "PPP: inbound frame "
1664 "not passed\n");
1665 kfree_skb(skb);
1666 return;
1667 }
1668 if (!(ppp->active_filter
1669 && sk_run_filter(skb, ppp->active_filter,
1670 ppp->active_len) == 0))
1671 ppp->last_recv = jiffies;
1672 __skb_pull(skb, 2);
1673 } else
1674 #endif /* CONFIG_PPP_FILTER */
1675 ppp->last_recv = jiffies;
1676
1677 if ((ppp->dev->flags & IFF_UP) == 0
1678 || ppp->npmode[npi] != NPMODE_PASS) {
1679 kfree_skb(skb);
1680 } else {
1681 /* chop off protocol */
1682 skb_pull_rcsum(skb, 2);
1683 skb->dev = ppp->dev;
1684 skb->protocol = htons(npindex_to_ethertype[npi]);
1685 skb_reset_mac_header(skb);
1686 netif_rx(skb);
1687 ppp->dev->last_rx = jiffies;
1688 }
1689 }
1690 return;
1691
1692 err:
1693 kfree_skb(skb);
1694 ppp_receive_error(ppp);
1695 }
1696
1697 static struct sk_buff *
1698 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1699 {
1700 int proto = PPP_PROTO(skb);
1701 struct sk_buff *ns;
1702 int len;
1703
1704 /* Until we fix all the decompressor's need to make sure
1705 * data portion is linear.
1706 */
1707 if (!pskb_may_pull(skb, skb->len))
1708 goto err;
1709
1710 if (proto == PPP_COMP) {
1711 int obuff_size;
1712
1713 switch(ppp->rcomp->compress_proto) {
1714 case CI_MPPE:
1715 obuff_size = ppp->mru + PPP_HDRLEN + 1;
1716 break;
1717 default:
1718 obuff_size = ppp->mru + PPP_HDRLEN;
1719 break;
1720 }
1721
1722 ns = dev_alloc_skb(obuff_size);
1723 if (!ns) {
1724 printk(KERN_ERR "ppp_decompress_frame: no memory\n");
1725 goto err;
1726 }
1727 /* the decompressor still expects the A/C bytes in the hdr */
1728 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1729 skb->len + 2, ns->data, obuff_size);
1730 if (len < 0) {
1731 /* Pass the compressed frame to pppd as an
1732 error indication. */
1733 if (len == DECOMP_FATALERROR)
1734 ppp->rstate |= SC_DC_FERROR;
1735 kfree_skb(ns);
1736 goto err;
1737 }
1738
1739 kfree_skb(skb);
1740 skb = ns;
1741 skb_put(skb, len);
1742 skb_pull(skb, 2); /* pull off the A/C bytes */
1743
1744 } else {
1745 /* Uncompressed frame - pass to decompressor so it
1746 can update its dictionary if necessary. */
1747 if (ppp->rcomp->incomp)
1748 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1749 skb->len + 2);
1750 }
1751
1752 return skb;
1753
1754 err:
1755 ppp->rstate |= SC_DC_ERROR;
1756 ppp_receive_error(ppp);
1757 return skb;
1758 }
1759
1760 #ifdef CONFIG_PPP_MULTILINK
1761 /*
1762 * Receive a multilink frame.
1763 * We put it on the reconstruction queue and then pull off
1764 * as many completed frames as we can.
1765 */
1766 static void
1767 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1768 {
1769 u32 mask, seq;
1770 struct channel *ch;
1771 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1772
1773 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
1774 goto err; /* no good, throw it away */
1775
1776 /* Decode sequence number and begin/end bits */
1777 if (ppp->flags & SC_MP_SHORTSEQ) {
1778 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1779 mask = 0xfff;
1780 } else {
1781 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1782 mask = 0xffffff;
1783 }
1784 skb->BEbits = skb->data[2];
1785 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
1786
1787 /*
1788 * Do protocol ID decompression on the first fragment of each packet.
1789 */
1790 if ((skb->BEbits & B) && (skb->data[0] & 1))
1791 *skb_push(skb, 1) = 0;
1792
1793 /*
1794 * Expand sequence number to 32 bits, making it as close
1795 * as possible to ppp->minseq.
1796 */
1797 seq |= ppp->minseq & ~mask;
1798 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
1799 seq += mask + 1;
1800 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
1801 seq -= mask + 1; /* should never happen */
1802 skb->sequence = seq;
1803 pch->lastseq = seq;
1804
1805 /*
1806 * If this packet comes before the next one we were expecting,
1807 * drop it.
1808 */
1809 if (seq_before(seq, ppp->nextseq)) {
1810 kfree_skb(skb);
1811 ++ppp->dev->stats.rx_dropped;
1812 ppp_receive_error(ppp);
1813 return;
1814 }
1815
1816 /*
1817 * Reevaluate minseq, the minimum over all channels of the
1818 * last sequence number received on each channel. Because of
1819 * the increasing sequence number rule, we know that any fragment
1820 * before `minseq' which hasn't arrived is never going to arrive.
1821 * The list of channels can't change because we have the receive
1822 * side of the ppp unit locked.
1823 */
1824 list_for_each_entry(ch, &ppp->channels, clist) {
1825 if (seq_before(ch->lastseq, seq))
1826 seq = ch->lastseq;
1827 }
1828 if (seq_before(ppp->minseq, seq))
1829 ppp->minseq = seq;
1830
1831 /* Put the fragment on the reconstruction queue */
1832 ppp_mp_insert(ppp, skb);
1833
1834 /* If the queue is getting long, don't wait any longer for packets
1835 before the start of the queue. */
1836 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
1837 struct sk_buff *skb = skb_peek(&ppp->mrq);
1838 if (seq_before(ppp->minseq, skb->sequence))
1839 ppp->minseq = skb->sequence;
1840 }
1841
1842 /* Pull completed packets off the queue and receive them. */
1843 while ((skb = ppp_mp_reconstruct(ppp)))
1844 ppp_receive_nonmp_frame(ppp, skb);
1845
1846 return;
1847
1848 err:
1849 kfree_skb(skb);
1850 ppp_receive_error(ppp);
1851 }
1852
1853 /*
1854 * Insert a fragment on the MP reconstruction queue.
1855 * The queue is ordered by increasing sequence number.
1856 */
1857 static void
1858 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
1859 {
1860 struct sk_buff *p;
1861 struct sk_buff_head *list = &ppp->mrq;
1862 u32 seq = skb->sequence;
1863
1864 /* N.B. we don't need to lock the list lock because we have the
1865 ppp unit receive-side lock. */
1866 skb_queue_walk(list, p) {
1867 if (seq_before(seq, p->sequence))
1868 break;
1869 }
1870 __skb_queue_before(list, p, skb);
1871 }
1872
1873 /*
1874 * Reconstruct a packet from the MP fragment queue.
1875 * We go through increasing sequence numbers until we find a
1876 * complete packet, or we get to the sequence number for a fragment
1877 * which hasn't arrived but might still do so.
1878 */
1879 static struct sk_buff *
1880 ppp_mp_reconstruct(struct ppp *ppp)
1881 {
1882 u32 seq = ppp->nextseq;
1883 u32 minseq = ppp->minseq;
1884 struct sk_buff_head *list = &ppp->mrq;
1885 struct sk_buff *p, *next;
1886 struct sk_buff *head, *tail;
1887 struct sk_buff *skb = NULL;
1888 int lost = 0, len = 0;
1889
1890 if (ppp->mrru == 0) /* do nothing until mrru is set */
1891 return NULL;
1892 head = list->next;
1893 tail = NULL;
1894 for (p = head; p != (struct sk_buff *) list; p = next) {
1895 next = p->next;
1896 if (seq_before(p->sequence, seq)) {
1897 /* this can't happen, anyway ignore the skb */
1898 printk(KERN_ERR "ppp_mp_reconstruct bad seq %u < %u\n",
1899 p->sequence, seq);
1900 head = next;
1901 continue;
1902 }
1903 if (p->sequence != seq) {
1904 /* Fragment `seq' is missing. If it is after
1905 minseq, it might arrive later, so stop here. */
1906 if (seq_after(seq, minseq))
1907 break;
1908 /* Fragment `seq' is lost, keep going. */
1909 lost = 1;
1910 seq = seq_before(minseq, p->sequence)?
1911 minseq + 1: p->sequence;
1912 next = p;
1913 continue;
1914 }
1915
1916 /*
1917 * At this point we know that all the fragments from
1918 * ppp->nextseq to seq are either present or lost.
1919 * Also, there are no complete packets in the queue
1920 * that have no missing fragments and end before this
1921 * fragment.
1922 */
1923
1924 /* B bit set indicates this fragment starts a packet */
1925 if (p->BEbits & B) {
1926 head = p;
1927 lost = 0;
1928 len = 0;
1929 }
1930
1931 len += p->len;
1932
1933 /* Got a complete packet yet? */
1934 if (lost == 0 && (p->BEbits & E) && (head->BEbits & B)) {
1935 if (len > ppp->mrru + 2) {
1936 ++ppp->dev->stats.rx_length_errors;
1937 printk(KERN_DEBUG "PPP: reconstructed packet"
1938 " is too long (%d)\n", len);
1939 } else if (p == head) {
1940 /* fragment is complete packet - reuse skb */
1941 tail = p;
1942 skb = skb_get(p);
1943 break;
1944 } else if ((skb = dev_alloc_skb(len)) == NULL) {
1945 ++ppp->dev->stats.rx_missed_errors;
1946 printk(KERN_DEBUG "PPP: no memory for "
1947 "reconstructed packet");
1948 } else {
1949 tail = p;
1950 break;
1951 }
1952 ppp->nextseq = seq + 1;
1953 }
1954
1955 /*
1956 * If this is the ending fragment of a packet,
1957 * and we haven't found a complete valid packet yet,
1958 * we can discard up to and including this fragment.
1959 */
1960 if (p->BEbits & E)
1961 head = next;
1962
1963 ++seq;
1964 }
1965
1966 /* If we have a complete packet, copy it all into one skb. */
1967 if (tail != NULL) {
1968 /* If we have discarded any fragments,
1969 signal a receive error. */
1970 if (head->sequence != ppp->nextseq) {
1971 if (ppp->debug & 1)
1972 printk(KERN_DEBUG " missed pkts %u..%u\n",
1973 ppp->nextseq, head->sequence-1);
1974 ++ppp->dev->stats.rx_dropped;
1975 ppp_receive_error(ppp);
1976 }
1977
1978 if (head != tail)
1979 /* copy to a single skb */
1980 for (p = head; p != tail->next; p = p->next)
1981 skb_copy_bits(p, 0, skb_put(skb, p->len), p->len);
1982 ppp->nextseq = tail->sequence + 1;
1983 head = tail->next;
1984 }
1985
1986 /* Discard all the skbuffs that we have copied the data out of
1987 or that we can't use. */
1988 while ((p = list->next) != head) {
1989 __skb_unlink(p, list);
1990 kfree_skb(p);
1991 }
1992
1993 return skb;
1994 }
1995 #endif /* CONFIG_PPP_MULTILINK */
1996
1997 /*
1998 * Channel interface.
1999 */
2000
2001 /*
2002 * Create a new, unattached ppp channel.
2003 */
2004 int
2005 ppp_register_channel(struct ppp_channel *chan)
2006 {
2007 struct channel *pch;
2008
2009 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2010 if (!pch)
2011 return -ENOMEM;
2012 pch->ppp = NULL;
2013 pch->chan = chan;
2014 chan->ppp = pch;
2015 init_ppp_file(&pch->file, CHANNEL);
2016 pch->file.hdrlen = chan->hdrlen;
2017 #ifdef CONFIG_PPP_MULTILINK
2018 pch->lastseq = -1;
2019 #endif /* CONFIG_PPP_MULTILINK */
2020 init_rwsem(&pch->chan_sem);
2021 spin_lock_init(&pch->downl);
2022 rwlock_init(&pch->upl);
2023 spin_lock_bh(&all_channels_lock);
2024 pch->file.index = ++last_channel_index;
2025 list_add(&pch->list, &new_channels);
2026 atomic_inc(&channel_count);
2027 spin_unlock_bh(&all_channels_lock);
2028 return 0;
2029 }
2030
2031 /*
2032 * Return the index of a channel.
2033 */
2034 int ppp_channel_index(struct ppp_channel *chan)
2035 {
2036 struct channel *pch = chan->ppp;
2037
2038 if (pch)
2039 return pch->file.index;
2040 return -1;
2041 }
2042
2043 /*
2044 * Return the PPP unit number to which a channel is connected.
2045 */
2046 int ppp_unit_number(struct ppp_channel *chan)
2047 {
2048 struct channel *pch = chan->ppp;
2049 int unit = -1;
2050
2051 if (pch) {
2052 read_lock_bh(&pch->upl);
2053 if (pch->ppp)
2054 unit = pch->ppp->file.index;
2055 read_unlock_bh(&pch->upl);
2056 }
2057 return unit;
2058 }
2059
2060 /*
2061 * Disconnect a channel from the generic layer.
2062 * This must be called in process context.
2063 */
2064 void
2065 ppp_unregister_channel(struct ppp_channel *chan)
2066 {
2067 struct channel *pch = chan->ppp;
2068
2069 if (!pch)
2070 return; /* should never happen */
2071 chan->ppp = NULL;
2072
2073 /*
2074 * This ensures that we have returned from any calls into the
2075 * the channel's start_xmit or ioctl routine before we proceed.
2076 */
2077 down_write(&pch->chan_sem);
2078 spin_lock_bh(&pch->downl);
2079 pch->chan = NULL;
2080 spin_unlock_bh(&pch->downl);
2081 up_write(&pch->chan_sem);
2082 ppp_disconnect_channel(pch);
2083 spin_lock_bh(&all_channels_lock);
2084 list_del(&pch->list);
2085 spin_unlock_bh(&all_channels_lock);
2086 pch->file.dead = 1;
2087 wake_up_interruptible(&pch->file.rwait);
2088 if (atomic_dec_and_test(&pch->file.refcnt))
2089 ppp_destroy_channel(pch);
2090 }
2091
2092 /*
2093 * Callback from a channel when it can accept more to transmit.
2094 * This should be called at BH/softirq level, not interrupt level.
2095 */
2096 void
2097 ppp_output_wakeup(struct ppp_channel *chan)
2098 {
2099 struct channel *pch = chan->ppp;
2100
2101 if (!pch)
2102 return;
2103 ppp_channel_push(pch);
2104 }
2105
2106 /*
2107 * Compression control.
2108 */
2109
2110 /* Process the PPPIOCSCOMPRESS ioctl. */
2111 static int
2112 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2113 {
2114 int err;
2115 struct compressor *cp, *ocomp;
2116 struct ppp_option_data data;
2117 void *state, *ostate;
2118 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2119
2120 err = -EFAULT;
2121 if (copy_from_user(&data, (void __user *) arg, sizeof(data))
2122 || (data.length <= CCP_MAX_OPTION_LENGTH
2123 && copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2124 goto out;
2125 err = -EINVAL;
2126 if (data.length > CCP_MAX_OPTION_LENGTH
2127 || ccp_option[1] < 2 || ccp_option[1] > data.length)
2128 goto out;
2129
2130 cp = try_then_request_module(
2131 find_compressor(ccp_option[0]),
2132 "ppp-compress-%d", ccp_option[0]);
2133 if (!cp)
2134 goto out;
2135
2136 err = -ENOBUFS;
2137 if (data.transmit) {
2138 state = cp->comp_alloc(ccp_option, data.length);
2139 if (state) {
2140 ppp_xmit_lock(ppp);
2141 ppp->xstate &= ~SC_COMP_RUN;
2142 ocomp = ppp->xcomp;
2143 ostate = ppp->xc_state;
2144 ppp->xcomp = cp;
2145 ppp->xc_state = state;
2146 ppp_xmit_unlock(ppp);
2147 if (ostate) {
2148 ocomp->comp_free(ostate);
2149 module_put(ocomp->owner);
2150 }
2151 err = 0;
2152 } else
2153 module_put(cp->owner);
2154
2155 } else {
2156 state = cp->decomp_alloc(ccp_option, data.length);
2157 if (state) {
2158 ppp_recv_lock(ppp);
2159 ppp->rstate &= ~SC_DECOMP_RUN;
2160 ocomp = ppp->rcomp;
2161 ostate = ppp->rc_state;
2162 ppp->rcomp = cp;
2163 ppp->rc_state = state;
2164 ppp_recv_unlock(ppp);
2165 if (ostate) {
2166 ocomp->decomp_free(ostate);
2167 module_put(ocomp->owner);
2168 }
2169 err = 0;
2170 } else
2171 module_put(cp->owner);
2172 }
2173
2174 out:
2175 return err;
2176 }
2177
2178 /*
2179 * Look at a CCP packet and update our state accordingly.
2180 * We assume the caller has the xmit or recv path locked.
2181 */
2182 static void
2183 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2184 {
2185 unsigned char *dp;
2186 int len;
2187
2188 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2189 return; /* no header */
2190 dp = skb->data + 2;
2191
2192 switch (CCP_CODE(dp)) {
2193 case CCP_CONFREQ:
2194
2195 /* A ConfReq starts negotiation of compression
2196 * in one direction of transmission,
2197 * and hence brings it down...but which way?
2198 *
2199 * Remember:
2200 * A ConfReq indicates what the sender would like to receive
2201 */
2202 if(inbound)
2203 /* He is proposing what I should send */
2204 ppp->xstate &= ~SC_COMP_RUN;
2205 else
2206 /* I am proposing to what he should send */
2207 ppp->rstate &= ~SC_DECOMP_RUN;
2208
2209 break;
2210
2211 case CCP_TERMREQ:
2212 case CCP_TERMACK:
2213 /*
2214 * CCP is going down, both directions of transmission
2215 */
2216 ppp->rstate &= ~SC_DECOMP_RUN;
2217 ppp->xstate &= ~SC_COMP_RUN;
2218 break;
2219
2220 case CCP_CONFACK:
2221 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2222 break;
2223 len = CCP_LENGTH(dp);
2224 if (!pskb_may_pull(skb, len + 2))
2225 return; /* too short */
2226 dp += CCP_HDRLEN;
2227 len -= CCP_HDRLEN;
2228 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2229 break;
2230 if (inbound) {
2231 /* we will start receiving compressed packets */
2232 if (!ppp->rc_state)
2233 break;
2234 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2235 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2236 ppp->rstate |= SC_DECOMP_RUN;
2237 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2238 }
2239 } else {
2240 /* we will soon start sending compressed packets */
2241 if (!ppp->xc_state)
2242 break;
2243 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2244 ppp->file.index, 0, ppp->debug))
2245 ppp->xstate |= SC_COMP_RUN;
2246 }
2247 break;
2248
2249 case CCP_RESETACK:
2250 /* reset the [de]compressor */
2251 if ((ppp->flags & SC_CCP_UP) == 0)
2252 break;
2253 if (inbound) {
2254 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2255 ppp->rcomp->decomp_reset(ppp->rc_state);
2256 ppp->rstate &= ~SC_DC_ERROR;
2257 }
2258 } else {
2259 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2260 ppp->xcomp->comp_reset(ppp->xc_state);
2261 }
2262 break;
2263 }
2264 }
2265
2266 /* Free up compression resources. */
2267 static void
2268 ppp_ccp_closed(struct ppp *ppp)
2269 {
2270 void *xstate, *rstate;
2271 struct compressor *xcomp, *rcomp;
2272
2273 ppp_lock(ppp);
2274 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2275 ppp->xstate = 0;
2276 xcomp = ppp->xcomp;
2277 xstate = ppp->xc_state;
2278 ppp->xc_state = NULL;
2279 ppp->rstate = 0;
2280 rcomp = ppp->rcomp;
2281 rstate = ppp->rc_state;
2282 ppp->rc_state = NULL;
2283 ppp_unlock(ppp);
2284
2285 if (xstate) {
2286 xcomp->comp_free(xstate);
2287 module_put(xcomp->owner);
2288 }
2289 if (rstate) {
2290 rcomp->decomp_free(rstate);
2291 module_put(rcomp->owner);
2292 }
2293 }
2294
2295 /* List of compressors. */
2296 static LIST_HEAD(compressor_list);
2297 static DEFINE_SPINLOCK(compressor_list_lock);
2298
2299 struct compressor_entry {
2300 struct list_head list;
2301 struct compressor *comp;
2302 };
2303
2304 static struct compressor_entry *
2305 find_comp_entry(int proto)
2306 {
2307 struct compressor_entry *ce;
2308
2309 list_for_each_entry(ce, &compressor_list, list) {
2310 if (ce->comp->compress_proto == proto)
2311 return ce;
2312 }
2313 return NULL;
2314 }
2315
2316 /* Register a compressor */
2317 int
2318 ppp_register_compressor(struct compressor *cp)
2319 {
2320 struct compressor_entry *ce;
2321 int ret;
2322 spin_lock(&compressor_list_lock);
2323 ret = -EEXIST;
2324 if (find_comp_entry(cp->compress_proto))
2325 goto out;
2326 ret = -ENOMEM;
2327 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2328 if (!ce)
2329 goto out;
2330 ret = 0;
2331 ce->comp = cp;
2332 list_add(&ce->list, &compressor_list);
2333 out:
2334 spin_unlock(&compressor_list_lock);
2335 return ret;
2336 }
2337
2338 /* Unregister a compressor */
2339 void
2340 ppp_unregister_compressor(struct compressor *cp)
2341 {
2342 struct compressor_entry *ce;
2343
2344 spin_lock(&compressor_list_lock);
2345 ce = find_comp_entry(cp->compress_proto);
2346 if (ce && ce->comp == cp) {
2347 list_del(&ce->list);
2348 kfree(ce);
2349 }
2350 spin_unlock(&compressor_list_lock);
2351 }
2352
2353 /* Find a compressor. */
2354 static struct compressor *
2355 find_compressor(int type)
2356 {
2357 struct compressor_entry *ce;
2358 struct compressor *cp = NULL;
2359
2360 spin_lock(&compressor_list_lock);
2361 ce = find_comp_entry(type);
2362 if (ce) {
2363 cp = ce->comp;
2364 if (!try_module_get(cp->owner))
2365 cp = NULL;
2366 }
2367 spin_unlock(&compressor_list_lock);
2368 return cp;
2369 }
2370
2371 /*
2372 * Miscelleneous stuff.
2373 */
2374
2375 static void
2376 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2377 {
2378 struct slcompress *vj = ppp->vj;
2379
2380 memset(st, 0, sizeof(*st));
2381 st->p.ppp_ipackets = ppp->dev->stats.rx_packets;
2382 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2383 st->p.ppp_ibytes = ppp->dev->stats.rx_bytes;
2384 st->p.ppp_opackets = ppp->dev->stats.tx_packets;
2385 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2386 st->p.ppp_obytes = ppp->dev->stats.tx_bytes;
2387 if (!vj)
2388 return;
2389 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2390 st->vj.vjs_compressed = vj->sls_o_compressed;
2391 st->vj.vjs_searches = vj->sls_o_searches;
2392 st->vj.vjs_misses = vj->sls_o_misses;
2393 st->vj.vjs_errorin = vj->sls_i_error;
2394 st->vj.vjs_tossed = vj->sls_i_tossed;
2395 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2396 st->vj.vjs_compressedin = vj->sls_i_compressed;
2397 }
2398
2399 /*
2400 * Stuff for handling the lists of ppp units and channels
2401 * and for initialization.
2402 */
2403
2404 /*
2405 * Create a new ppp interface unit. Fails if it can't allocate memory
2406 * or if there is already a unit with the requested number.
2407 * unit == -1 means allocate a new number.
2408 */
2409 static struct ppp *
2410 ppp_create_interface(int unit, int *retp)
2411 {
2412 struct ppp *ppp;
2413 struct net_device *dev = NULL;
2414 int ret = -ENOMEM;
2415 int i;
2416
2417 ppp = kzalloc(sizeof(struct ppp), GFP_KERNEL);
2418 if (!ppp)
2419 goto out;
2420 dev = alloc_netdev(0, "", ppp_setup);
2421 if (!dev)
2422 goto out1;
2423
2424 ppp->mru = PPP_MRU;
2425 init_ppp_file(&ppp->file, INTERFACE);
2426 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2427 for (i = 0; i < NUM_NP; ++i)
2428 ppp->npmode[i] = NPMODE_PASS;
2429 INIT_LIST_HEAD(&ppp->channels);
2430 spin_lock_init(&ppp->rlock);
2431 spin_lock_init(&ppp->wlock);
2432 #ifdef CONFIG_PPP_MULTILINK
2433 ppp->minseq = -1;
2434 skb_queue_head_init(&ppp->mrq);
2435 #endif /* CONFIG_PPP_MULTILINK */
2436 ppp->dev = dev;
2437 dev->priv = ppp;
2438
2439 dev->hard_start_xmit = ppp_start_xmit;
2440 dev->do_ioctl = ppp_net_ioctl;
2441
2442 ret = -EEXIST;
2443 mutex_lock(&all_ppp_mutex);
2444 if (unit < 0)
2445 unit = cardmap_find_first_free(all_ppp_units);
2446 else if (cardmap_get(all_ppp_units, unit) != NULL)
2447 goto out2; /* unit already exists */
2448
2449 /* Initialize the new ppp unit */
2450 ppp->file.index = unit;
2451 sprintf(dev->name, "ppp%d", unit);
2452
2453 ret = register_netdev(dev);
2454 if (ret != 0) {
2455 printk(KERN_ERR "PPP: couldn't register device %s (%d)\n",
2456 dev->name, ret);
2457 goto out2;
2458 }
2459
2460 atomic_inc(&ppp_unit_count);
2461 ret = cardmap_set(&all_ppp_units, unit, ppp);
2462 if (ret != 0)
2463 goto out3;
2464
2465 mutex_unlock(&all_ppp_mutex);
2466 *retp = 0;
2467 return ppp;
2468
2469 out3:
2470 atomic_dec(&ppp_unit_count);
2471 unregister_netdev(dev);
2472 out2:
2473 mutex_unlock(&all_ppp_mutex);
2474 free_netdev(dev);
2475 out1:
2476 kfree(ppp);
2477 out:
2478 *retp = ret;
2479 return NULL;
2480 }
2481
2482 /*
2483 * Initialize a ppp_file structure.
2484 */
2485 static void
2486 init_ppp_file(struct ppp_file *pf, int kind)
2487 {
2488 pf->kind = kind;
2489 skb_queue_head_init(&pf->xq);
2490 skb_queue_head_init(&pf->rq);
2491 atomic_set(&pf->refcnt, 1);
2492 init_waitqueue_head(&pf->rwait);
2493 }
2494
2495 /*
2496 * Take down a ppp interface unit - called when the owning file
2497 * (the one that created the unit) is closed or detached.
2498 */
2499 static void ppp_shutdown_interface(struct ppp *ppp)
2500 {
2501 mutex_lock(&all_ppp_mutex);
2502 /* This will call dev_close() for us. */
2503 ppp_lock(ppp);
2504 if (!ppp->closing) {
2505 ppp->closing = 1;
2506 ppp_unlock(ppp);
2507 unregister_netdev(ppp->dev);
2508 } else
2509 ppp_unlock(ppp);
2510
2511 cardmap_set(&all_ppp_units, ppp->file.index, NULL);
2512 ppp->file.dead = 1;
2513 ppp->owner = NULL;
2514 wake_up_interruptible(&ppp->file.rwait);
2515 mutex_unlock(&all_ppp_mutex);
2516 }
2517
2518 /*
2519 * Free the memory used by a ppp unit. This is only called once
2520 * there are no channels connected to the unit and no file structs
2521 * that reference the unit.
2522 */
2523 static void ppp_destroy_interface(struct ppp *ppp)
2524 {
2525 atomic_dec(&ppp_unit_count);
2526
2527 if (!ppp->file.dead || ppp->n_channels) {
2528 /* "can't happen" */
2529 printk(KERN_ERR "ppp: destroying ppp struct %p but dead=%d "
2530 "n_channels=%d !\n", ppp, ppp->file.dead,
2531 ppp->n_channels);
2532 return;
2533 }
2534
2535 ppp_ccp_closed(ppp);
2536 if (ppp->vj) {
2537 slhc_free(ppp->vj);
2538 ppp->vj = NULL;
2539 }
2540 skb_queue_purge(&ppp->file.xq);
2541 skb_queue_purge(&ppp->file.rq);
2542 #ifdef CONFIG_PPP_MULTILINK
2543 skb_queue_purge(&ppp->mrq);
2544 #endif /* CONFIG_PPP_MULTILINK */
2545 #ifdef CONFIG_PPP_FILTER
2546 kfree(ppp->pass_filter);
2547 ppp->pass_filter = NULL;
2548 kfree(ppp->active_filter);
2549 ppp->active_filter = NULL;
2550 #endif /* CONFIG_PPP_FILTER */
2551
2552 if (ppp->xmit_pending)
2553 kfree_skb(ppp->xmit_pending);
2554
2555 free_netdev(ppp->dev);
2556 }
2557
2558 /*
2559 * Locate an existing ppp unit.
2560 * The caller should have locked the all_ppp_mutex.
2561 */
2562 static struct ppp *
2563 ppp_find_unit(int unit)
2564 {
2565 return cardmap_get(all_ppp_units, unit);
2566 }
2567
2568 /*
2569 * Locate an existing ppp channel.
2570 * The caller should have locked the all_channels_lock.
2571 * First we look in the new_channels list, then in the
2572 * all_channels list. If found in the new_channels list,
2573 * we move it to the all_channels list. This is for speed
2574 * when we have a lot of channels in use.
2575 */
2576 static struct channel *
2577 ppp_find_channel(int unit)
2578 {
2579 struct channel *pch;
2580
2581 list_for_each_entry(pch, &new_channels, list) {
2582 if (pch->file.index == unit) {
2583 list_move(&pch->list, &all_channels);
2584 return pch;
2585 }
2586 }
2587 list_for_each_entry(pch, &all_channels, list) {
2588 if (pch->file.index == unit)
2589 return pch;
2590 }
2591 return NULL;
2592 }
2593
2594 /*
2595 * Connect a PPP channel to a PPP interface unit.
2596 */
2597 static int
2598 ppp_connect_channel(struct channel *pch, int unit)
2599 {
2600 struct ppp *ppp;
2601 int ret = -ENXIO;
2602 int hdrlen;
2603
2604 mutex_lock(&all_ppp_mutex);
2605 ppp = ppp_find_unit(unit);
2606 if (!ppp)
2607 goto out;
2608 write_lock_bh(&pch->upl);
2609 ret = -EINVAL;
2610 if (pch->ppp)
2611 goto outl;
2612
2613 ppp_lock(ppp);
2614 if (pch->file.hdrlen > ppp->file.hdrlen)
2615 ppp->file.hdrlen = pch->file.hdrlen;
2616 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2617 if (hdrlen > ppp->dev->hard_header_len)
2618 ppp->dev->hard_header_len = hdrlen;
2619 list_add_tail(&pch->clist, &ppp->channels);
2620 ++ppp->n_channels;
2621 pch->ppp = ppp;
2622 atomic_inc(&ppp->file.refcnt);
2623 ppp_unlock(ppp);
2624 ret = 0;
2625
2626 outl:
2627 write_unlock_bh(&pch->upl);
2628 out:
2629 mutex_unlock(&all_ppp_mutex);
2630 return ret;
2631 }
2632
2633 /*
2634 * Disconnect a channel from its ppp unit.
2635 */
2636 static int
2637 ppp_disconnect_channel(struct channel *pch)
2638 {
2639 struct ppp *ppp;
2640 int err = -EINVAL;
2641
2642 write_lock_bh(&pch->upl);
2643 ppp = pch->ppp;
2644 pch->ppp = NULL;
2645 write_unlock_bh(&pch->upl);
2646 if (ppp) {
2647 /* remove it from the ppp unit's list */
2648 ppp_lock(ppp);
2649 list_del(&pch->clist);
2650 if (--ppp->n_channels == 0)
2651 wake_up_interruptible(&ppp->file.rwait);
2652 ppp_unlock(ppp);
2653 if (atomic_dec_and_test(&ppp->file.refcnt))
2654 ppp_destroy_interface(ppp);
2655 err = 0;
2656 }
2657 return err;
2658 }
2659
2660 /*
2661 * Free up the resources used by a ppp channel.
2662 */
2663 static void ppp_destroy_channel(struct channel *pch)
2664 {
2665 atomic_dec(&channel_count);
2666
2667 if (!pch->file.dead) {
2668 /* "can't happen" */
2669 printk(KERN_ERR "ppp: destroying undead channel %p !\n",
2670 pch);
2671 return;
2672 }
2673 skb_queue_purge(&pch->file.xq);
2674 skb_queue_purge(&pch->file.rq);
2675 kfree(pch);
2676 }
2677
2678 static void __exit ppp_cleanup(void)
2679 {
2680 /* should never happen */
2681 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2682 printk(KERN_ERR "PPP: removing module but units remain!\n");
2683 cardmap_destroy(&all_ppp_units);
2684 unregister_chrdev(PPP_MAJOR, "ppp");
2685 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
2686 class_destroy(ppp_class);
2687 }
2688
2689 /*
2690 * Cardmap implementation.
2691 */
2692 static void *cardmap_get(struct cardmap *map, unsigned int nr)
2693 {
2694 struct cardmap *p;
2695 int i;
2696
2697 for (p = map; p != NULL; ) {
2698 if ((i = nr >> p->shift) >= CARDMAP_WIDTH)
2699 return NULL;
2700 if (p->shift == 0)
2701 return p->ptr[i];
2702 nr &= ~(CARDMAP_MASK << p->shift);
2703 p = p->ptr[i];
2704 }
2705 return NULL;
2706 }
2707
2708 static int cardmap_set(struct cardmap **pmap, unsigned int nr, void *ptr)
2709 {
2710 struct cardmap *p;
2711 int i;
2712
2713 p = *pmap;
2714 if (p == NULL || (nr >> p->shift) >= CARDMAP_WIDTH) {
2715 do {
2716 /* need a new top level */
2717 struct cardmap *np = kzalloc(sizeof(*np), GFP_KERNEL);
2718 if (!np)
2719 goto enomem;
2720 np->ptr[0] = p;
2721 if (p != NULL) {
2722 np->shift = p->shift + CARDMAP_ORDER;
2723 p->parent = np;
2724 } else
2725 np->shift = 0;
2726 p = np;
2727 } while ((nr >> p->shift) >= CARDMAP_WIDTH);
2728 *pmap = p;
2729 }
2730 while (p->shift > 0) {
2731 i = (nr >> p->shift) & CARDMAP_MASK;
2732 if (p->ptr[i] == NULL) {
2733 struct cardmap *np = kzalloc(sizeof(*np), GFP_KERNEL);
2734 if (!np)
2735 goto enomem;
2736 np->shift = p->shift - CARDMAP_ORDER;
2737 np->parent = p;
2738 p->ptr[i] = np;
2739 }
2740 if (ptr == NULL)
2741 clear_bit(i, &p->inuse);
2742 p = p->ptr[i];
2743 }
2744 i = nr & CARDMAP_MASK;
2745 p->ptr[i] = ptr;
2746 if (ptr != NULL)
2747 set_bit(i, &p->inuse);
2748 else
2749 clear_bit(i, &p->inuse);
2750 return 0;
2751 enomem:
2752 return -ENOMEM;
2753 }
2754
2755 static unsigned int cardmap_find_first_free(struct cardmap *map)
2756 {
2757 struct cardmap *p;
2758 unsigned int nr = 0;
2759 int i;
2760
2761 if ((p = map) == NULL)
2762 return 0;
2763 for (;;) {
2764 i = find_first_zero_bit(&p->inuse, CARDMAP_WIDTH);
2765 if (i >= CARDMAP_WIDTH) {
2766 if (p->parent == NULL)
2767 return CARDMAP_WIDTH << p->shift;
2768 p = p->parent;
2769 i = (nr >> p->shift) & CARDMAP_MASK;
2770 set_bit(i, &p->inuse);
2771 continue;
2772 }
2773 nr = (nr & (~CARDMAP_MASK << p->shift)) | (i << p->shift);
2774 if (p->shift == 0 || p->ptr[i] == NULL)
2775 return nr;
2776 p = p->ptr[i];
2777 }
2778 }
2779
2780 static void cardmap_destroy(struct cardmap **pmap)
2781 {
2782 struct cardmap *p, *np;
2783 int i;
2784
2785 for (p = *pmap; p != NULL; p = np) {
2786 if (p->shift != 0) {
2787 for (i = 0; i < CARDMAP_WIDTH; ++i)
2788 if (p->ptr[i] != NULL)
2789 break;
2790 if (i < CARDMAP_WIDTH) {
2791 np = p->ptr[i];
2792 p->ptr[i] = NULL;
2793 continue;
2794 }
2795 }
2796 np = p->parent;
2797 kfree(p);
2798 }
2799 *pmap = NULL;
2800 }
2801
2802 /* Module/initialization stuff */
2803
2804 module_init(ppp_init);
2805 module_exit(ppp_cleanup);
2806
2807 EXPORT_SYMBOL(ppp_register_channel);
2808 EXPORT_SYMBOL(ppp_unregister_channel);
2809 EXPORT_SYMBOL(ppp_channel_index);
2810 EXPORT_SYMBOL(ppp_unit_number);
2811 EXPORT_SYMBOL(ppp_input);
2812 EXPORT_SYMBOL(ppp_input_error);
2813 EXPORT_SYMBOL(ppp_output_wakeup);
2814 EXPORT_SYMBOL(ppp_register_compressor);
2815 EXPORT_SYMBOL(ppp_unregister_compressor);
2816 MODULE_LICENSE("GPL");
2817 MODULE_ALIAS_CHARDEV_MAJOR(PPP_MAJOR);
2818 MODULE_ALIAS("/dev/ppp");
Support for the Chinese Samsung S3C2440 based development boards