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ppp: convert to net_device_ops
[linux-2.6/mini2440.git] / drivers / net / ppp_generic.c
blobc1e57c093e086e160a9782653c312dba23e2fa4c
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 #ifdef CONFIG_PPP_MULTILINK
120 int nxchan; /* next channel to send something on */
121 u32 nxseq; /* next sequence number to send */
122 int mrru; /* MP: max reconst. receive unit */
123 u32 nextseq; /* MP: seq no of next packet */
124 u32 minseq; /* MP: min of most recent seqnos */
125 struct sk_buff_head mrq; /* MP: receive reconstruction queue */
126 #endif /* CONFIG_PPP_MULTILINK */
127 #ifdef CONFIG_PPP_FILTER
128 struct sock_filter *pass_filter; /* filter for packets to pass */
129 struct sock_filter *active_filter;/* filter for pkts to reset idle */
130 unsigned pass_len, active_len;
131 #endif /* CONFIG_PPP_FILTER */
132 };
133
134 /*
135 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
136 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
137 * SC_MUST_COMP
138 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
139 * Bits in xstate: SC_COMP_RUN
140 */
141 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
142 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
143 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
144
145 /*
146 * Private data structure for each channel.
147 * This includes the data structure used for multilink.
148 */
149 struct channel {
150 struct ppp_file file; /* stuff for read/write/poll */
151 struct list_head list; /* link in all/new_channels list */
152 struct ppp_channel *chan; /* public channel data structure */
153 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
154 spinlock_t downl; /* protects `chan', file.xq dequeue */
155 struct ppp *ppp; /* ppp unit we're connected to */
156 struct list_head clist; /* link in list of channels per unit */
157 rwlock_t upl; /* protects `ppp' */
158 #ifdef CONFIG_PPP_MULTILINK
159 u8 avail; /* flag used in multilink stuff */
160 u8 had_frag; /* >= 1 fragments have been sent */
161 u32 lastseq; /* MP: last sequence # received */
162 #endif /* CONFIG_PPP_MULTILINK */
163 };
164
165 /*
166 * SMP locking issues:
167 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
168 * list and the ppp.n_channels field, you need to take both locks
169 * before you modify them.
170 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
171 * channel.downl.
172 */
173
174 /*
175 * A cardmap represents a mapping from unsigned integers to pointers,
176 * and provides a fast "find lowest unused number" operation.
177 * It uses a broad (32-way) tree with a bitmap at each level.
178 * It is designed to be space-efficient for small numbers of entries
179 * and time-efficient for large numbers of entries.
180 */
181 #define CARDMAP_ORDER 5
182 #define CARDMAP_WIDTH (1U << CARDMAP_ORDER)
183 #define CARDMAP_MASK (CARDMAP_WIDTH - 1)
184
185 struct cardmap {
186 int shift;
187 unsigned long inuse;
188 struct cardmap *parent;
189 void *ptr[CARDMAP_WIDTH];
190 };
191 static void *cardmap_get(struct cardmap *map, unsigned int nr);
192 static int cardmap_set(struct cardmap **map, unsigned int nr, void *ptr);
193 static unsigned int cardmap_find_first_free(struct cardmap *map);
194 static void cardmap_destroy(struct cardmap **map);
195
196 /*
197 * all_ppp_mutex protects the all_ppp_units mapping.
198 * It also ensures that finding a ppp unit in the all_ppp_units map
199 * and updating its file.refcnt field is atomic.
200 */
201 static DEFINE_MUTEX(all_ppp_mutex);
202 static struct cardmap *all_ppp_units;
203 static atomic_t ppp_unit_count = ATOMIC_INIT(0);
204
205 /*
206 * all_channels_lock protects all_channels and last_channel_index,
207 * and the atomicity of find a channel and updating its file.refcnt
208 * field.
209 */
210 static DEFINE_SPINLOCK(all_channels_lock);
211 static LIST_HEAD(all_channels);
212 static LIST_HEAD(new_channels);
213 static int last_channel_index;
214 static atomic_t channel_count = ATOMIC_INIT(0);
215
216 /* Get the PPP protocol number from a skb */
217 #define PPP_PROTO(skb) (((skb)->data[0] << 8) + (skb)->data[1])
218
219 /* We limit the length of ppp->file.rq to this (arbitrary) value */
220 #define PPP_MAX_RQLEN 32
221
222 /*
223 * Maximum number of multilink fragments queued up.
224 * This has to be large enough to cope with the maximum latency of
225 * the slowest channel relative to the others. Strictly it should
226 * depend on the number of channels and their characteristics.
227 */
228 #define PPP_MP_MAX_QLEN 128
229
230 /* Multilink header bits. */
231 #define B 0x80 /* this fragment begins a packet */
232 #define E 0x40 /* this fragment ends a packet */
233
234 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */
235 #define seq_before(a, b) ((s32)((a) - (b)) < 0)
236 #define seq_after(a, b) ((s32)((a) - (b)) > 0)
237
238 /* Prototypes. */
239 static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file,
240 unsigned int cmd, unsigned long arg);
241 static void ppp_xmit_process(struct ppp *ppp);
242 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
243 static void ppp_push(struct ppp *ppp);
244 static void ppp_channel_push(struct channel *pch);
245 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
246 struct channel *pch);
247 static void ppp_receive_error(struct ppp *ppp);
248 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
249 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
250 struct sk_buff *skb);
251 #ifdef CONFIG_PPP_MULTILINK
252 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
253 struct channel *pch);
254 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
255 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
256 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
257 #endif /* CONFIG_PPP_MULTILINK */
258 static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
259 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
260 static void ppp_ccp_closed(struct ppp *ppp);
261 static struct compressor *find_compressor(int type);
262 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
263 static struct ppp *ppp_create_interface(int unit, int *retp);
264 static void init_ppp_file(struct ppp_file *pf, int kind);
265 static void ppp_shutdown_interface(struct ppp *ppp);
266 static void ppp_destroy_interface(struct ppp *ppp);
267 static struct ppp *ppp_find_unit(int unit);
268 static struct channel *ppp_find_channel(int unit);
269 static int ppp_connect_channel(struct channel *pch, int unit);
270 static int ppp_disconnect_channel(struct channel *pch);
271 static void ppp_destroy_channel(struct channel *pch);
272
273 static struct class *ppp_class;
274
275 /* Translates a PPP protocol number to a NP index (NP == network protocol) */
276 static inline int proto_to_npindex(int proto)
277 {
278 switch (proto) {
279 case PPP_IP:
280 return NP_IP;
281 case PPP_IPV6:
282 return NP_IPV6;
283 case PPP_IPX:
284 return NP_IPX;
285 case PPP_AT:
286 return NP_AT;
287 case PPP_MPLS_UC:
288 return NP_MPLS_UC;
289 case PPP_MPLS_MC:
290 return NP_MPLS_MC;
291 }
292 return -EINVAL;
293 }
294
295 /* Translates an NP index into a PPP protocol number */
296 static const int npindex_to_proto[NUM_NP] = {
297 PPP_IP,
298 PPP_IPV6,
299 PPP_IPX,
300 PPP_AT,
301 PPP_MPLS_UC,
302 PPP_MPLS_MC,
303 };
304
305 /* Translates an ethertype into an NP index */
306 static inline int ethertype_to_npindex(int ethertype)
307 {
308 switch (ethertype) {
309 case ETH_P_IP:
310 return NP_IP;
311 case ETH_P_IPV6:
312 return NP_IPV6;
313 case ETH_P_IPX:
314 return NP_IPX;
315 case ETH_P_PPPTALK:
316 case ETH_P_ATALK:
317 return NP_AT;
318 case ETH_P_MPLS_UC:
319 return NP_MPLS_UC;
320 case ETH_P_MPLS_MC:
321 return NP_MPLS_MC;
322 }
323 return -1;
324 }
325
326 /* Translates an NP index into an ethertype */
327 static const int npindex_to_ethertype[NUM_NP] = {
328 ETH_P_IP,
329 ETH_P_IPV6,
330 ETH_P_IPX,
331 ETH_P_PPPTALK,
332 ETH_P_MPLS_UC,
333 ETH_P_MPLS_MC,
334 };
335
336 /*
337 * Locking shorthand.
338 */
339 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
340 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
341 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
342 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
343 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
344 ppp_recv_lock(ppp); } while (0)
345 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
346 ppp_xmit_unlock(ppp); } while (0)
347
348 /*
349 * /dev/ppp device routines.
350 * The /dev/ppp device is used by pppd to control the ppp unit.
351 * It supports the read, write, ioctl and poll functions.
352 * Open instances of /dev/ppp can be in one of three states:
353 * unattached, attached to a ppp unit, or attached to a ppp channel.
354 */
355 static int ppp_open(struct inode *inode, struct file *file)
356 {
357 cycle_kernel_lock();
358 /*
359 * This could (should?) be enforced by the permissions on /dev/ppp.
360 */
361 if (!capable(CAP_NET_ADMIN))
362 return -EPERM;
363 return 0;
364 }
365
366 static int ppp_release(struct inode *unused, struct file *file)
367 {
368 struct ppp_file *pf = file->private_data;
369 struct ppp *ppp;
370
371 if (pf) {
372 file->private_data = NULL;
373 if (pf->kind == INTERFACE) {
374 ppp = PF_TO_PPP(pf);
375 if (file == ppp->owner)
376 ppp_shutdown_interface(ppp);
377 }
378 if (atomic_dec_and_test(&pf->refcnt)) {
379 switch (pf->kind) {
380 case INTERFACE:
381 ppp_destroy_interface(PF_TO_PPP(pf));
382 break;
383 case CHANNEL:
384 ppp_destroy_channel(PF_TO_CHANNEL(pf));
385 break;
386 }
387 }
388 }
389 return 0;
390 }
391
392 static ssize_t ppp_read(struct file *file, char __user *buf,
393 size_t count, loff_t *ppos)
394 {
395 struct ppp_file *pf = file->private_data;
396 DECLARE_WAITQUEUE(wait, current);
397 ssize_t ret;
398 struct sk_buff *skb = NULL;
399
400 ret = count;
401
402 if (!pf)
403 return -ENXIO;
404 add_wait_queue(&pf->rwait, &wait);
405 for (;;) {
406 set_current_state(TASK_INTERRUPTIBLE);
407 skb = skb_dequeue(&pf->rq);
408 if (skb)
409 break;
410 ret = 0;
411 if (pf->dead)
412 break;
413 if (pf->kind == INTERFACE) {
414 /*
415 * Return 0 (EOF) on an interface that has no
416 * channels connected, unless it is looping
417 * network traffic (demand mode).
418 */
419 struct ppp *ppp = PF_TO_PPP(pf);
420 if (ppp->n_channels == 0
421 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
422 break;
423 }
424 ret = -EAGAIN;
425 if (file->f_flags & O_NONBLOCK)
426 break;
427 ret = -ERESTARTSYS;
428 if (signal_pending(current))
429 break;
430 schedule();
431 }
432 set_current_state(TASK_RUNNING);
433 remove_wait_queue(&pf->rwait, &wait);
434
435 if (!skb)
436 goto out;
437
438 ret = -EOVERFLOW;
439 if (skb->len > count)
440 goto outf;
441 ret = -EFAULT;
442 if (copy_to_user(buf, skb->data, skb->len))
443 goto outf;
444 ret = skb->len;
445
446 outf:
447 kfree_skb(skb);
448 out:
449 return ret;
450 }
451
452 static ssize_t ppp_write(struct file *file, const char __user *buf,
453 size_t count, loff_t *ppos)
454 {
455 struct ppp_file *pf = file->private_data;
456 struct sk_buff *skb;
457 ssize_t ret;
458
459 if (!pf)
460 return -ENXIO;
461 ret = -ENOMEM;
462 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
463 if (!skb)
464 goto out;
465 skb_reserve(skb, pf->hdrlen);
466 ret = -EFAULT;
467 if (copy_from_user(skb_put(skb, count), buf, count)) {
468 kfree_skb(skb);
469 goto out;
470 }
471
472 skb_queue_tail(&pf->xq, skb);
473
474 switch (pf->kind) {
475 case INTERFACE:
476 ppp_xmit_process(PF_TO_PPP(pf));
477 break;
478 case CHANNEL:
479 ppp_channel_push(PF_TO_CHANNEL(pf));
480 break;
481 }
482
483 ret = count;
484
485 out:
486 return ret;
487 }
488
489 /* No kernel lock - fine */
490 static unsigned int ppp_poll(struct file *file, poll_table *wait)
491 {
492 struct ppp_file *pf = file->private_data;
493 unsigned int mask;
494
495 if (!pf)
496 return 0;
497 poll_wait(file, &pf->rwait, wait);
498 mask = POLLOUT | POLLWRNORM;
499 if (skb_peek(&pf->rq))
500 mask |= POLLIN | POLLRDNORM;
501 if (pf->dead)
502 mask |= POLLHUP;
503 else if (pf->kind == INTERFACE) {
504 /* see comment in ppp_read */
505 struct ppp *ppp = PF_TO_PPP(pf);
506 if (ppp->n_channels == 0
507 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
508 mask |= POLLIN | POLLRDNORM;
509 }
510
511 return mask;
512 }
513
514 #ifdef CONFIG_PPP_FILTER
515 static int get_filter(void __user *arg, struct sock_filter **p)
516 {
517 struct sock_fprog uprog;
518 struct sock_filter *code = NULL;
519 int len, err;
520
521 if (copy_from_user(&uprog, arg, sizeof(uprog)))
522 return -EFAULT;
523
524 if (!uprog.len) {
525 *p = NULL;
526 return 0;
527 }
528
529 len = uprog.len * sizeof(struct sock_filter);
530 code = kmalloc(len, GFP_KERNEL);
531 if (code == NULL)
532 return -ENOMEM;
533
534 if (copy_from_user(code, uprog.filter, len)) {
535 kfree(code);
536 return -EFAULT;
537 }
538
539 err = sk_chk_filter(code, uprog.len);
540 if (err) {
541 kfree(code);
542 return err;
543 }
544
545 *p = code;
546 return uprog.len;
547 }
548 #endif /* CONFIG_PPP_FILTER */
549
550 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
551 {
552 struct ppp_file *pf = file->private_data;
553 struct ppp *ppp;
554 int err = -EFAULT, val, val2, i;
555 struct ppp_idle idle;
556 struct npioctl npi;
557 int unit, cflags;
558 struct slcompress *vj;
559 void __user *argp = (void __user *)arg;
560 int __user *p = argp;
561
562 if (!pf)
563 return ppp_unattached_ioctl(pf, file, cmd, arg);
564
565 if (cmd == PPPIOCDETACH) {
566 /*
567 * We have to be careful here... if the file descriptor
568 * has been dup'd, we could have another process in the
569 * middle of a poll using the same file *, so we had
570 * better not free the interface data structures -
571 * instead we fail the ioctl. Even in this case, we
572 * shut down the interface if we are the owner of it.
573 * Actually, we should get rid of PPPIOCDETACH, userland
574 * (i.e. pppd) could achieve the same effect by closing
575 * this fd and reopening /dev/ppp.
576 */
577 err = -EINVAL;
578 lock_kernel();
579 if (pf->kind == INTERFACE) {
580 ppp = PF_TO_PPP(pf);
581 if (file == ppp->owner)
582 ppp_shutdown_interface(ppp);
583 }
584 if (atomic_long_read(&file->f_count) <= 2) {
585 ppp_release(NULL, file);
586 err = 0;
587 } else
588 printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%ld\n",
589 atomic_long_read(&file->f_count));
590 unlock_kernel();
591 return err;
592 }
593
594 if (pf->kind == CHANNEL) {
595 struct channel *pch;
596 struct ppp_channel *chan;
597
598 lock_kernel();
599 pch = PF_TO_CHANNEL(pf);
600
601 switch (cmd) {
602 case PPPIOCCONNECT:
603 if (get_user(unit, p))
604 break;
605 err = ppp_connect_channel(pch, unit);
606 break;
607
608 case PPPIOCDISCONN:
609 err = ppp_disconnect_channel(pch);
610 break;
611
612 default:
613 down_read(&pch->chan_sem);
614 chan = pch->chan;
615 err = -ENOTTY;
616 if (chan && chan->ops->ioctl)
617 err = chan->ops->ioctl(chan, cmd, arg);
618 up_read(&pch->chan_sem);
619 }
620 unlock_kernel();
621 return err;
622 }
623
624 if (pf->kind != INTERFACE) {
625 /* can't happen */
626 printk(KERN_ERR "PPP: not interface or channel??\n");
627 return -EINVAL;
628 }
629
630 lock_kernel();
631 ppp = PF_TO_PPP(pf);
632 switch (cmd) {
633 case PPPIOCSMRU:
634 if (get_user(val, p))
635 break;
636 ppp->mru = val;
637 err = 0;
638 break;
639
640 case PPPIOCSFLAGS:
641 if (get_user(val, p))
642 break;
643 ppp_lock(ppp);
644 cflags = ppp->flags & ~val;
645 ppp->flags = val & SC_FLAG_BITS;
646 ppp_unlock(ppp);
647 if (cflags & SC_CCP_OPEN)
648 ppp_ccp_closed(ppp);
649 err = 0;
650 break;
651
652 case PPPIOCGFLAGS:
653 val = ppp->flags | ppp->xstate | ppp->rstate;
654 if (put_user(val, p))
655 break;
656 err = 0;
657 break;
658
659 case PPPIOCSCOMPRESS:
660 err = ppp_set_compress(ppp, arg);
661 break;
662
663 case PPPIOCGUNIT:
664 if (put_user(ppp->file.index, p))
665 break;
666 err = 0;
667 break;
668
669 case PPPIOCSDEBUG:
670 if (get_user(val, p))
671 break;
672 ppp->debug = val;
673 err = 0;
674 break;
675
676 case PPPIOCGDEBUG:
677 if (put_user(ppp->debug, p))
678 break;
679 err = 0;
680 break;
681
682 case PPPIOCGIDLE:
683 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
684 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
685 if (copy_to_user(argp, &idle, sizeof(idle)))
686 break;
687 err = 0;
688 break;
689
690 case PPPIOCSMAXCID:
691 if (get_user(val, p))
692 break;
693 val2 = 15;
694 if ((val >> 16) != 0) {
695 val2 = val >> 16;
696 val &= 0xffff;
697 }
698 vj = slhc_init(val2+1, val+1);
699 if (!vj) {
700 printk(KERN_ERR "PPP: no memory (VJ compressor)\n");
701 err = -ENOMEM;
702 break;
703 }
704 ppp_lock(ppp);
705 if (ppp->vj)
706 slhc_free(ppp->vj);
707 ppp->vj = vj;
708 ppp_unlock(ppp);
709 err = 0;
710 break;
711
712 case PPPIOCGNPMODE:
713 case PPPIOCSNPMODE:
714 if (copy_from_user(&npi, argp, sizeof(npi)))
715 break;
716 err = proto_to_npindex(npi.protocol);
717 if (err < 0)
718 break;
719 i = err;
720 if (cmd == PPPIOCGNPMODE) {
721 err = -EFAULT;
722 npi.mode = ppp->npmode[i];
723 if (copy_to_user(argp, &npi, sizeof(npi)))
724 break;
725 } else {
726 ppp->npmode[i] = npi.mode;
727 /* we may be able to transmit more packets now (??) */
728 netif_wake_queue(ppp->dev);
729 }
730 err = 0;
731 break;
732
733 #ifdef CONFIG_PPP_FILTER
734 case PPPIOCSPASS:
735 {
736 struct sock_filter *code;
737 err = get_filter(argp, &code);
738 if (err >= 0) {
739 ppp_lock(ppp);
740 kfree(ppp->pass_filter);
741 ppp->pass_filter = code;
742 ppp->pass_len = err;
743 ppp_unlock(ppp);
744 err = 0;
745 }
746 break;
747 }
748 case PPPIOCSACTIVE:
749 {
750 struct sock_filter *code;
751 err = get_filter(argp, &code);
752 if (err >= 0) {
753 ppp_lock(ppp);
754 kfree(ppp->active_filter);
755 ppp->active_filter = code;
756 ppp->active_len = err;
757 ppp_unlock(ppp);
758 err = 0;
759 }
760 break;
761 }
762 #endif /* CONFIG_PPP_FILTER */
763
764 #ifdef CONFIG_PPP_MULTILINK
765 case PPPIOCSMRRU:
766 if (get_user(val, p))
767 break;
768 ppp_recv_lock(ppp);
769 ppp->mrru = val;
770 ppp_recv_unlock(ppp);
771 err = 0;
772 break;
773 #endif /* CONFIG_PPP_MULTILINK */
774
775 default:
776 err = -ENOTTY;
777 }
778 unlock_kernel();
779 return err;
780 }
781
782 static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file,
783 unsigned int cmd, unsigned long arg)
784 {
785 int unit, err = -EFAULT;
786 struct ppp *ppp;
787 struct channel *chan;
788 int __user *p = (int __user *)arg;
789
790 lock_kernel();
791 switch (cmd) {
792 case PPPIOCNEWUNIT:
793 /* Create a new ppp unit */
794 if (get_user(unit, p))
795 break;
796 ppp = ppp_create_interface(unit, &err);
797 if (!ppp)
798 break;
799 file->private_data = &ppp->file;
800 ppp->owner = file;
801 err = -EFAULT;
802 if (put_user(ppp->file.index, p))
803 break;
804 err = 0;
805 break;
806
807 case PPPIOCATTACH:
808 /* Attach to an existing ppp unit */
809 if (get_user(unit, p))
810 break;
811 mutex_lock(&all_ppp_mutex);
812 err = -ENXIO;
813 ppp = ppp_find_unit(unit);
814 if (ppp) {
815 atomic_inc(&ppp->file.refcnt);
816 file->private_data = &ppp->file;
817 err = 0;
818 }
819 mutex_unlock(&all_ppp_mutex);
820 break;
821
822 case PPPIOCATTCHAN:
823 if (get_user(unit, p))
824 break;
825 spin_lock_bh(&all_channels_lock);
826 err = -ENXIO;
827 chan = ppp_find_channel(unit);
828 if (chan) {
829 atomic_inc(&chan->file.refcnt);
830 file->private_data = &chan->file;
831 err = 0;
832 }
833 spin_unlock_bh(&all_channels_lock);
834 break;
835
836 default:
837 err = -ENOTTY;
838 }
839 unlock_kernel();
840 return err;
841 }
842
843 static const struct file_operations ppp_device_fops = {
844 .owner = THIS_MODULE,
845 .read = ppp_read,
846 .write = ppp_write,
847 .poll = ppp_poll,
848 .unlocked_ioctl = ppp_ioctl,
849 .open = ppp_open,
850 .release = ppp_release
851 };
852
853 #define PPP_MAJOR 108
854
855 /* Called at boot time if ppp is compiled into the kernel,
856 or at module load time (from init_module) if compiled as a module. */
857 static int __init ppp_init(void)
858 {
859 int err;
860
861 printk(KERN_INFO "PPP generic driver version " PPP_VERSION "\n");
862 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
863 if (!err) {
864 ppp_class = class_create(THIS_MODULE, "ppp");
865 if (IS_ERR(ppp_class)) {
866 err = PTR_ERR(ppp_class);
867 goto out_chrdev;
868 }
869 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL,
870 "ppp");
871 }
872
873 out:
874 if (err)
875 printk(KERN_ERR "failed to register PPP device (%d)\n", err);
876 return err;
877
878 out_chrdev:
879 unregister_chrdev(PPP_MAJOR, "ppp");
880 goto out;
881 }
882
883 /*
884 * Network interface unit routines.
885 */
886 static int
887 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
888 {
889 struct ppp *ppp = (struct ppp *) dev->priv;
890 int npi, proto;
891 unsigned char *pp;
892
893 npi = ethertype_to_npindex(ntohs(skb->protocol));
894 if (npi < 0)
895 goto outf;
896
897 /* Drop, accept or reject the packet */
898 switch (ppp->npmode[npi]) {
899 case NPMODE_PASS:
900 break;
901 case NPMODE_QUEUE:
902 /* it would be nice to have a way to tell the network
903 system to queue this one up for later. */
904 goto outf;
905 case NPMODE_DROP:
906 case NPMODE_ERROR:
907 goto outf;
908 }
909
910 /* Put the 2-byte PPP protocol number on the front,
911 making sure there is room for the address and control fields. */
912 if (skb_cow_head(skb, PPP_HDRLEN))
913 goto outf;
914
915 pp = skb_push(skb, 2);
916 proto = npindex_to_proto[npi];
917 pp[0] = proto >> 8;
918 pp[1] = proto;
919
920 netif_stop_queue(dev);
921 skb_queue_tail(&ppp->file.xq, skb);
922 ppp_xmit_process(ppp);
923 return 0;
924
925 outf:
926 kfree_skb(skb);
927 ++ppp->dev->stats.tx_dropped;
928 return 0;
929 }
930
931 static int
932 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
933 {
934 struct ppp *ppp = dev->priv;
935 int err = -EFAULT;
936 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
937 struct ppp_stats stats;
938 struct ppp_comp_stats cstats;
939 char *vers;
940
941 switch (cmd) {
942 case SIOCGPPPSTATS:
943 ppp_get_stats(ppp, &stats);
944 if (copy_to_user(addr, &stats, sizeof(stats)))
945 break;
946 err = 0;
947 break;
948
949 case SIOCGPPPCSTATS:
950 memset(&cstats, 0, sizeof(cstats));
951 if (ppp->xc_state)
952 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
953 if (ppp->rc_state)
954 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
955 if (copy_to_user(addr, &cstats, sizeof(cstats)))
956 break;
957 err = 0;
958 break;
959
960 case SIOCGPPPVER:
961 vers = PPP_VERSION;
962 if (copy_to_user(addr, vers, strlen(vers) + 1))
963 break;
964 err = 0;
965 break;
966
967 default:
968 err = -EINVAL;
969 }
970
971 return err;
972 }
973
974 static const struct net_device_ops ppp_netdev_ops = {
975 .ndo_do_ioctl = ppp_net_ioctl,
976 };
977
978 static void ppp_setup(struct net_device *dev)
979 {
980 dev->netdev_ops = &ppp_netdev_ops;
981 dev->hard_header_len = PPP_HDRLEN;
982 dev->mtu = PPP_MTU;
983 dev->addr_len = 0;
984 dev->tx_queue_len = 3;
985 dev->type = ARPHRD_PPP;
986 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
987 }
988
989 /*
990 * Transmit-side routines.
991 */
992
993 /*
994 * Called to do any work queued up on the transmit side
995 * that can now be done.
996 */
997 static void
998 ppp_xmit_process(struct ppp *ppp)
999 {
1000 struct sk_buff *skb;
1001
1002 ppp_xmit_lock(ppp);
1003 if (ppp->dev) {
1004 ppp_push(ppp);
1005 while (!ppp->xmit_pending
1006 && (skb = skb_dequeue(&ppp->file.xq)))
1007 ppp_send_frame(ppp, skb);
1008 /* If there's no work left to do, tell the core net
1009 code that we can accept some more. */
1010 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1011 netif_wake_queue(ppp->dev);
1012 }
1013 ppp_xmit_unlock(ppp);
1014 }
1015
1016 static inline struct sk_buff *
1017 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1018 {
1019 struct sk_buff *new_skb;
1020 int len;
1021 int new_skb_size = ppp->dev->mtu +
1022 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1023 int compressor_skb_size = ppp->dev->mtu +
1024 ppp->xcomp->comp_extra + PPP_HDRLEN;
1025 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1026 if (!new_skb) {
1027 if (net_ratelimit())
1028 printk(KERN_ERR "PPP: no memory (comp pkt)\n");
1029 return NULL;
1030 }
1031 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1032 skb_reserve(new_skb,
1033 ppp->dev->hard_header_len - PPP_HDRLEN);
1034
1035 /* compressor still expects A/C bytes in hdr */
1036 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1037 new_skb->data, skb->len + 2,
1038 compressor_skb_size);
1039 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1040 kfree_skb(skb);
1041 skb = new_skb;
1042 skb_put(skb, len);
1043 skb_pull(skb, 2); /* pull off A/C bytes */
1044 } else if (len == 0) {
1045 /* didn't compress, or CCP not up yet */
1046 kfree_skb(new_skb);
1047 new_skb = skb;
1048 } else {
1049 /*
1050 * (len < 0)
1051 * MPPE requires that we do not send unencrypted
1052 * frames. The compressor will return -1 if we
1053 * should drop the frame. We cannot simply test
1054 * the compress_proto because MPPE and MPPC share
1055 * the same number.
1056 */
1057 if (net_ratelimit())
1058 printk(KERN_ERR "ppp: compressor dropped pkt\n");
1059 kfree_skb(skb);
1060 kfree_skb(new_skb);
1061 new_skb = NULL;
1062 }
1063 return new_skb;
1064 }
1065
1066 /*
1067 * Compress and send a frame.
1068 * The caller should have locked the xmit path,
1069 * and xmit_pending should be 0.
1070 */
1071 static void
1072 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1073 {
1074 int proto = PPP_PROTO(skb);
1075 struct sk_buff *new_skb;
1076 int len;
1077 unsigned char *cp;
1078
1079 if (proto < 0x8000) {
1080 #ifdef CONFIG_PPP_FILTER
1081 /* check if we should pass this packet */
1082 /* the filter instructions are constructed assuming
1083 a four-byte PPP header on each packet */
1084 *skb_push(skb, 2) = 1;
1085 if (ppp->pass_filter
1086 && sk_run_filter(skb, ppp->pass_filter,
1087 ppp->pass_len) == 0) {
1088 if (ppp->debug & 1)
1089 printk(KERN_DEBUG "PPP: outbound frame not passed\n");
1090 kfree_skb(skb);
1091 return;
1092 }
1093 /* if this packet passes the active filter, record the time */
1094 if (!(ppp->active_filter
1095 && sk_run_filter(skb, ppp->active_filter,
1096 ppp->active_len) == 0))
1097 ppp->last_xmit = jiffies;
1098 skb_pull(skb, 2);
1099 #else
1100 /* for data packets, record the time */
1101 ppp->last_xmit = jiffies;
1102 #endif /* CONFIG_PPP_FILTER */
1103 }
1104
1105 ++ppp->dev->stats.tx_packets;
1106 ppp->dev->stats.tx_bytes += skb->len - 2;
1107
1108 switch (proto) {
1109 case PPP_IP:
1110 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1111 break;
1112 /* try to do VJ TCP header compression */
1113 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1114 GFP_ATOMIC);
1115 if (!new_skb) {
1116 printk(KERN_ERR "PPP: no memory (VJ comp pkt)\n");
1117 goto drop;
1118 }
1119 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1120 cp = skb->data + 2;
1121 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1122 new_skb->data + 2, &cp,
1123 !(ppp->flags & SC_NO_TCP_CCID));
1124 if (cp == skb->data + 2) {
1125 /* didn't compress */
1126 kfree_skb(new_skb);
1127 } else {
1128 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1129 proto = PPP_VJC_COMP;
1130 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1131 } else {
1132 proto = PPP_VJC_UNCOMP;
1133 cp[0] = skb->data[2];
1134 }
1135 kfree_skb(skb);
1136 skb = new_skb;
1137 cp = skb_put(skb, len + 2);
1138 cp[0] = 0;
1139 cp[1] = proto;
1140 }
1141 break;
1142
1143 case PPP_CCP:
1144 /* peek at outbound CCP frames */
1145 ppp_ccp_peek(ppp, skb, 0);
1146 break;
1147 }
1148
1149 /* try to do packet compression */
1150 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state
1151 && proto != PPP_LCP && proto != PPP_CCP) {
1152 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1153 if (net_ratelimit())
1154 printk(KERN_ERR "ppp: compression required but down - pkt dropped.\n");
1155 goto drop;
1156 }
1157 skb = pad_compress_skb(ppp, skb);
1158 if (!skb)
1159 goto drop;
1160 }
1161
1162 /*
1163 * If we are waiting for traffic (demand dialling),
1164 * queue it up for pppd to receive.
1165 */
1166 if (ppp->flags & SC_LOOP_TRAFFIC) {
1167 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1168 goto drop;
1169 skb_queue_tail(&ppp->file.rq, skb);
1170 wake_up_interruptible(&ppp->file.rwait);
1171 return;
1172 }
1173
1174 ppp->xmit_pending = skb;
1175 ppp_push(ppp);
1176 return;
1177
1178 drop:
1179 if (skb)
1180 kfree_skb(skb);
1181 ++ppp->dev->stats.tx_errors;
1182 }
1183
1184 /*
1185 * Try to send the frame in xmit_pending.
1186 * The caller should have the xmit path locked.
1187 */
1188 static void
1189 ppp_push(struct ppp *ppp)
1190 {
1191 struct list_head *list;
1192 struct channel *pch;
1193 struct sk_buff *skb = ppp->xmit_pending;
1194
1195 if (!skb)
1196 return;
1197
1198 list = &ppp->channels;
1199 if (list_empty(list)) {
1200 /* nowhere to send the packet, just drop it */
1201 ppp->xmit_pending = NULL;
1202 kfree_skb(skb);
1203 return;
1204 }
1205
1206 if ((ppp->flags & SC_MULTILINK) == 0) {
1207 /* not doing multilink: send it down the first channel */
1208 list = list->next;
1209 pch = list_entry(list, struct channel, clist);
1210
1211 spin_lock_bh(&pch->downl);
1212 if (pch->chan) {
1213 if (pch->chan->ops->start_xmit(pch->chan, skb))
1214 ppp->xmit_pending = NULL;
1215 } else {
1216 /* channel got unregistered */
1217 kfree_skb(skb);
1218 ppp->xmit_pending = NULL;
1219 }
1220 spin_unlock_bh(&pch->downl);
1221 return;
1222 }
1223
1224 #ifdef CONFIG_PPP_MULTILINK
1225 /* Multilink: fragment the packet over as many links
1226 as can take the packet at the moment. */
1227 if (!ppp_mp_explode(ppp, skb))
1228 return;
1229 #endif /* CONFIG_PPP_MULTILINK */
1230
1231 ppp->xmit_pending = NULL;
1232 kfree_skb(skb);
1233 }
1234
1235 #ifdef CONFIG_PPP_MULTILINK
1236 /*
1237 * Divide a packet to be transmitted into fragments and
1238 * send them out the individual links.
1239 */
1240 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1241 {
1242 int len, fragsize;
1243 int i, bits, hdrlen, mtu;
1244 int flen;
1245 int navail, nfree;
1246 int nbigger;
1247 unsigned char *p, *q;
1248 struct list_head *list;
1249 struct channel *pch;
1250 struct sk_buff *frag;
1251 struct ppp_channel *chan;
1252
1253 nfree = 0; /* # channels which have no packet already queued */
1254 navail = 0; /* total # of usable channels (not deregistered) */
1255 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1256 i = 0;
1257 list_for_each_entry(pch, &ppp->channels, clist) {
1258 navail += pch->avail = (pch->chan != NULL);
1259 if (pch->avail) {
1260 if (skb_queue_empty(&pch->file.xq) ||
1261 !pch->had_frag) {
1262 pch->avail = 2;
1263 ++nfree;
1264 }
1265 if (!pch->had_frag && i < ppp->nxchan)
1266 ppp->nxchan = i;
1267 }
1268 ++i;
1269 }
1270
1271 /*
1272 * Don't start sending this packet unless at least half of
1273 * the channels are free. This gives much better TCP
1274 * performance if we have a lot of channels.
1275 */
1276 if (nfree == 0 || nfree < navail / 2)
1277 return 0; /* can't take now, leave it in xmit_pending */
1278
1279 /* Do protocol field compression (XXX this should be optional) */
1280 p = skb->data;
1281 len = skb->len;
1282 if (*p == 0) {
1283 ++p;
1284 --len;
1285 }
1286
1287 /*
1288 * Decide on fragment size.
1289 * We create a fragment for each free channel regardless of
1290 * how small they are (i.e. even 0 length) in order to minimize
1291 * the time that it will take to detect when a channel drops
1292 * a fragment.
1293 */
1294 fragsize = len;
1295 if (nfree > 1)
1296 fragsize = DIV_ROUND_UP(fragsize, nfree);
1297 /* nbigger channels get fragsize bytes, the rest get fragsize-1,
1298 except if nbigger==0, then they all get fragsize. */
1299 nbigger = len % nfree;
1300
1301 /* skip to the channel after the one we last used
1302 and start at that one */
1303 list = &ppp->channels;
1304 for (i = 0; i < ppp->nxchan; ++i) {
1305 list = list->next;
1306 if (list == &ppp->channels) {
1307 i = 0;
1308 break;
1309 }
1310 }
1311
1312 /* create a fragment for each channel */
1313 bits = B;
1314 while (nfree > 0 || len > 0) {
1315 list = list->next;
1316 if (list == &ppp->channels) {
1317 i = 0;
1318 continue;
1319 }
1320 pch = list_entry(list, struct channel, clist);
1321 ++i;
1322 if (!pch->avail)
1323 continue;
1324
1325 /*
1326 * Skip this channel if it has a fragment pending already and
1327 * we haven't given a fragment to all of the free channels.
1328 */
1329 if (pch->avail == 1) {
1330 if (nfree > 0)
1331 continue;
1332 } else {
1333 --nfree;
1334 pch->avail = 1;
1335 }
1336
1337 /* check the channel's mtu and whether it is still attached. */
1338 spin_lock_bh(&pch->downl);
1339 if (pch->chan == NULL) {
1340 /* can't use this channel, it's being deregistered */
1341 spin_unlock_bh(&pch->downl);
1342 pch->avail = 0;
1343 if (--navail == 0)
1344 break;
1345 continue;
1346 }
1347
1348 /*
1349 * Create a fragment for this channel of
1350 * min(max(mtu+2-hdrlen, 4), fragsize, len) bytes.
1351 * If mtu+2-hdrlen < 4, that is a ridiculously small
1352 * MTU, so we use mtu = 2 + hdrlen.
1353 */
1354 if (fragsize > len)
1355 fragsize = len;
1356 flen = fragsize;
1357 mtu = pch->chan->mtu + 2 - hdrlen;
1358 if (mtu < 4)
1359 mtu = 4;
1360 if (flen > mtu)
1361 flen = mtu;
1362 if (flen == len && nfree == 0)
1363 bits |= E;
1364 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1365 if (!frag)
1366 goto noskb;
1367 q = skb_put(frag, flen + hdrlen);
1368
1369 /* make the MP header */
1370 q[0] = PPP_MP >> 8;
1371 q[1] = PPP_MP;
1372 if (ppp->flags & SC_MP_XSHORTSEQ) {
1373 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1374 q[3] = ppp->nxseq;
1375 } else {
1376 q[2] = bits;
1377 q[3] = ppp->nxseq >> 16;
1378 q[4] = ppp->nxseq >> 8;
1379 q[5] = ppp->nxseq;
1380 }
1381
1382 /*
1383 * Copy the data in.
1384 * Unfortunately there is a bug in older versions of
1385 * the Linux PPP multilink reconstruction code where it
1386 * drops 0-length fragments. Therefore we make sure the
1387 * fragment has at least one byte of data. Any bytes
1388 * we add in this situation will end up as padding on the
1389 * end of the reconstructed packet.
1390 */
1391 if (flen == 0)
1392 *skb_put(frag, 1) = 0;
1393 else
1394 memcpy(q + hdrlen, p, flen);
1395
1396 /* try to send it down the channel */
1397 chan = pch->chan;
1398 if (!skb_queue_empty(&pch->file.xq) ||
1399 !chan->ops->start_xmit(chan, frag))
1400 skb_queue_tail(&pch->file.xq, frag);
1401 pch->had_frag = 1;
1402 p += flen;
1403 len -= flen;
1404 ++ppp->nxseq;
1405 bits = 0;
1406 spin_unlock_bh(&pch->downl);
1407
1408 if (--nbigger == 0 && fragsize > 0)
1409 --fragsize;
1410 }
1411 ppp->nxchan = i;
1412
1413 return 1;
1414
1415 noskb:
1416 spin_unlock_bh(&pch->downl);
1417 if (ppp->debug & 1)
1418 printk(KERN_ERR "PPP: no memory (fragment)\n");
1419 ++ppp->dev->stats.tx_errors;
1420 ++ppp->nxseq;
1421 return 1; /* abandon the frame */
1422 }
1423 #endif /* CONFIG_PPP_MULTILINK */
1424
1425 /*
1426 * Try to send data out on a channel.
1427 */
1428 static void
1429 ppp_channel_push(struct channel *pch)
1430 {
1431 struct sk_buff *skb;
1432 struct ppp *ppp;
1433
1434 spin_lock_bh(&pch->downl);
1435 if (pch->chan) {
1436 while (!skb_queue_empty(&pch->file.xq)) {
1437 skb = skb_dequeue(&pch->file.xq);
1438 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1439 /* put the packet back and try again later */
1440 skb_queue_head(&pch->file.xq, skb);
1441 break;
1442 }
1443 }
1444 } else {
1445 /* channel got deregistered */
1446 skb_queue_purge(&pch->file.xq);
1447 }
1448 spin_unlock_bh(&pch->downl);
1449 /* see if there is anything from the attached unit to be sent */
1450 if (skb_queue_empty(&pch->file.xq)) {
1451 read_lock_bh(&pch->upl);
1452 ppp = pch->ppp;
1453 if (ppp)
1454 ppp_xmit_process(ppp);
1455 read_unlock_bh(&pch->upl);
1456 }
1457 }
1458
1459 /*
1460 * Receive-side routines.
1461 */
1462
1463 /* misuse a few fields of the skb for MP reconstruction */
1464 #define sequence priority
1465 #define BEbits cb[0]
1466
1467 static inline void
1468 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1469 {
1470 ppp_recv_lock(ppp);
1471 /* ppp->dev == 0 means interface is closing down */
1472 if (ppp->dev)
1473 ppp_receive_frame(ppp, skb, pch);
1474 else
1475 kfree_skb(skb);
1476 ppp_recv_unlock(ppp);
1477 }
1478
1479 void
1480 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1481 {
1482 struct channel *pch = chan->ppp;
1483 int proto;
1484
1485 if (!pch || skb->len == 0) {
1486 kfree_skb(skb);
1487 return;
1488 }
1489
1490 proto = PPP_PROTO(skb);
1491 read_lock_bh(&pch->upl);
1492 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1493 /* put it on the channel queue */
1494 skb_queue_tail(&pch->file.rq, skb);
1495 /* drop old frames if queue too long */
1496 while (pch->file.rq.qlen > PPP_MAX_RQLEN
1497 && (skb = skb_dequeue(&pch->file.rq)))
1498 kfree_skb(skb);
1499 wake_up_interruptible(&pch->file.rwait);
1500 } else {
1501 ppp_do_recv(pch->ppp, skb, pch);
1502 }
1503 read_unlock_bh(&pch->upl);
1504 }
1505
1506 /* Put a 0-length skb in the receive queue as an error indication */
1507 void
1508 ppp_input_error(struct ppp_channel *chan, int code)
1509 {
1510 struct channel *pch = chan->ppp;
1511 struct sk_buff *skb;
1512
1513 if (!pch)
1514 return;
1515
1516 read_lock_bh(&pch->upl);
1517 if (pch->ppp) {
1518 skb = alloc_skb(0, GFP_ATOMIC);
1519 if (skb) {
1520 skb->len = 0; /* probably unnecessary */
1521 skb->cb[0] = code;
1522 ppp_do_recv(pch->ppp, skb, pch);
1523 }
1524 }
1525 read_unlock_bh(&pch->upl);
1526 }
1527
1528 /*
1529 * We come in here to process a received frame.
1530 * The receive side of the ppp unit is locked.
1531 */
1532 static void
1533 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1534 {
1535 if (pskb_may_pull(skb, 2)) {
1536 #ifdef CONFIG_PPP_MULTILINK
1537 /* XXX do channel-level decompression here */
1538 if (PPP_PROTO(skb) == PPP_MP)
1539 ppp_receive_mp_frame(ppp, skb, pch);
1540 else
1541 #endif /* CONFIG_PPP_MULTILINK */
1542 ppp_receive_nonmp_frame(ppp, skb);
1543 return;
1544 }
1545
1546 if (skb->len > 0)
1547 /* note: a 0-length skb is used as an error indication */
1548 ++ppp->dev->stats.rx_length_errors;
1549
1550 kfree_skb(skb);
1551 ppp_receive_error(ppp);
1552 }
1553
1554 static void
1555 ppp_receive_error(struct ppp *ppp)
1556 {
1557 ++ppp->dev->stats.rx_errors;
1558 if (ppp->vj)
1559 slhc_toss(ppp->vj);
1560 }
1561
1562 static void
1563 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1564 {
1565 struct sk_buff *ns;
1566 int proto, len, npi;
1567
1568 /*
1569 * Decompress the frame, if compressed.
1570 * Note that some decompressors need to see uncompressed frames
1571 * that come in as well as compressed frames.
1572 */
1573 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)
1574 && (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1575 skb = ppp_decompress_frame(ppp, skb);
1576
1577 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1578 goto err;
1579
1580 proto = PPP_PROTO(skb);
1581 switch (proto) {
1582 case PPP_VJC_COMP:
1583 /* decompress VJ compressed packets */
1584 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1585 goto err;
1586
1587 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1588 /* copy to a new sk_buff with more tailroom */
1589 ns = dev_alloc_skb(skb->len + 128);
1590 if (!ns) {
1591 printk(KERN_ERR"PPP: no memory (VJ decomp)\n");
1592 goto err;
1593 }
1594 skb_reserve(ns, 2);
1595 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1596 kfree_skb(skb);
1597 skb = ns;
1598 }
1599 else
1600 skb->ip_summed = CHECKSUM_NONE;
1601
1602 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1603 if (len <= 0) {
1604 printk(KERN_DEBUG "PPP: VJ decompression error\n");
1605 goto err;
1606 }
1607 len += 2;
1608 if (len > skb->len)
1609 skb_put(skb, len - skb->len);
1610 else if (len < skb->len)
1611 skb_trim(skb, len);
1612 proto = PPP_IP;
1613 break;
1614
1615 case PPP_VJC_UNCOMP:
1616 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1617 goto err;
1618
1619 /* Until we fix the decompressor need to make sure
1620 * data portion is linear.
1621 */
1622 if (!pskb_may_pull(skb, skb->len))
1623 goto err;
1624
1625 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1626 printk(KERN_ERR "PPP: VJ uncompressed error\n");
1627 goto err;
1628 }
1629 proto = PPP_IP;
1630 break;
1631
1632 case PPP_CCP:
1633 ppp_ccp_peek(ppp, skb, 1);
1634 break;
1635 }
1636
1637 ++ppp->dev->stats.rx_packets;
1638 ppp->dev->stats.rx_bytes += skb->len - 2;
1639
1640 npi = proto_to_npindex(proto);
1641 if (npi < 0) {
1642 /* control or unknown frame - pass it to pppd */
1643 skb_queue_tail(&ppp->file.rq, skb);
1644 /* limit queue length by dropping old frames */
1645 while (ppp->file.rq.qlen > PPP_MAX_RQLEN
1646 && (skb = skb_dequeue(&ppp->file.rq)))
1647 kfree_skb(skb);
1648 /* wake up any process polling or blocking on read */
1649 wake_up_interruptible(&ppp->file.rwait);
1650
1651 } else {
1652 /* network protocol frame - give it to the kernel */
1653
1654 #ifdef CONFIG_PPP_FILTER
1655 /* check if the packet passes the pass and active filters */
1656 /* the filter instructions are constructed assuming
1657 a four-byte PPP header on each packet */
1658 if (ppp->pass_filter || ppp->active_filter) {
1659 if (skb_cloned(skb) &&
1660 pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
1661 goto err;
1662
1663 *skb_push(skb, 2) = 0;
1664 if (ppp->pass_filter
1665 && sk_run_filter(skb, ppp->pass_filter,
1666 ppp->pass_len) == 0) {
1667 if (ppp->debug & 1)
1668 printk(KERN_DEBUG "PPP: inbound frame "
1669 "not passed\n");
1670 kfree_skb(skb);
1671 return;
1672 }
1673 if (!(ppp->active_filter
1674 && sk_run_filter(skb, ppp->active_filter,
1675 ppp->active_len) == 0))
1676 ppp->last_recv = jiffies;
1677 __skb_pull(skb, 2);
1678 } else
1679 #endif /* CONFIG_PPP_FILTER */
1680 ppp->last_recv = jiffies;
1681
1682 if ((ppp->dev->flags & IFF_UP) == 0
1683 || ppp->npmode[npi] != NPMODE_PASS) {
1684 kfree_skb(skb);
1685 } else {
1686 /* chop off protocol */
1687 skb_pull_rcsum(skb, 2);
1688 skb->dev = ppp->dev;
1689 skb->protocol = htons(npindex_to_ethertype[npi]);
1690 skb_reset_mac_header(skb);
1691 netif_rx(skb);
1692 }
1693 }
1694 return;
1695
1696 err:
1697 kfree_skb(skb);
1698 ppp_receive_error(ppp);
1699 }
1700
1701 static struct sk_buff *
1702 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1703 {
1704 int proto = PPP_PROTO(skb);
1705 struct sk_buff *ns;
1706 int len;
1707
1708 /* Until we fix all the decompressor's need to make sure
1709 * data portion is linear.
1710 */
1711 if (!pskb_may_pull(skb, skb->len))
1712 goto err;
1713
1714 if (proto == PPP_COMP) {
1715 int obuff_size;
1716
1717 switch(ppp->rcomp->compress_proto) {
1718 case CI_MPPE:
1719 obuff_size = ppp->mru + PPP_HDRLEN + 1;
1720 break;
1721 default:
1722 obuff_size = ppp->mru + PPP_HDRLEN;
1723 break;
1724 }
1725
1726 ns = dev_alloc_skb(obuff_size);
1727 if (!ns) {
1728 printk(KERN_ERR "ppp_decompress_frame: no memory\n");
1729 goto err;
1730 }
1731 /* the decompressor still expects the A/C bytes in the hdr */
1732 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1733 skb->len + 2, ns->data, obuff_size);
1734 if (len < 0) {
1735 /* Pass the compressed frame to pppd as an
1736 error indication. */
1737 if (len == DECOMP_FATALERROR)
1738 ppp->rstate |= SC_DC_FERROR;
1739 kfree_skb(ns);
1740 goto err;
1741 }
1742
1743 kfree_skb(skb);
1744 skb = ns;
1745 skb_put(skb, len);
1746 skb_pull(skb, 2); /* pull off the A/C bytes */
1747
1748 } else {
1749 /* Uncompressed frame - pass to decompressor so it
1750 can update its dictionary if necessary. */
1751 if (ppp->rcomp->incomp)
1752 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1753 skb->len + 2);
1754 }
1755
1756 return skb;
1757
1758 err:
1759 ppp->rstate |= SC_DC_ERROR;
1760 ppp_receive_error(ppp);
1761 return skb;
1762 }
1763
1764 #ifdef CONFIG_PPP_MULTILINK
1765 /*
1766 * Receive a multilink frame.
1767 * We put it on the reconstruction queue and then pull off
1768 * as many completed frames as we can.
1769 */
1770 static void
1771 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1772 {
1773 u32 mask, seq;
1774 struct channel *ch;
1775 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1776
1777 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
1778 goto err; /* no good, throw it away */
1779
1780 /* Decode sequence number and begin/end bits */
1781 if (ppp->flags & SC_MP_SHORTSEQ) {
1782 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1783 mask = 0xfff;
1784 } else {
1785 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1786 mask = 0xffffff;
1787 }
1788 skb->BEbits = skb->data[2];
1789 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
1790
1791 /*
1792 * Do protocol ID decompression on the first fragment of each packet.
1793 */
1794 if ((skb->BEbits & B) && (skb->data[0] & 1))
1795 *skb_push(skb, 1) = 0;
1796
1797 /*
1798 * Expand sequence number to 32 bits, making it as close
1799 * as possible to ppp->minseq.
1800 */
1801 seq |= ppp->minseq & ~mask;
1802 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
1803 seq += mask + 1;
1804 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
1805 seq -= mask + 1; /* should never happen */
1806 skb->sequence = seq;
1807 pch->lastseq = seq;
1808
1809 /*
1810 * If this packet comes before the next one we were expecting,
1811 * drop it.
1812 */
1813 if (seq_before(seq, ppp->nextseq)) {
1814 kfree_skb(skb);
1815 ++ppp->dev->stats.rx_dropped;
1816 ppp_receive_error(ppp);
1817 return;
1818 }
1819
1820 /*
1821 * Reevaluate minseq, the minimum over all channels of the
1822 * last sequence number received on each channel. Because of
1823 * the increasing sequence number rule, we know that any fragment
1824 * before `minseq' which hasn't arrived is never going to arrive.
1825 * The list of channels can't change because we have the receive
1826 * side of the ppp unit locked.
1827 */
1828 list_for_each_entry(ch, &ppp->channels, clist) {
1829 if (seq_before(ch->lastseq, seq))
1830 seq = ch->lastseq;
1831 }
1832 if (seq_before(ppp->minseq, seq))
1833 ppp->minseq = seq;
1834
1835 /* Put the fragment on the reconstruction queue */
1836 ppp_mp_insert(ppp, skb);
1837
1838 /* If the queue is getting long, don't wait any longer for packets
1839 before the start of the queue. */
1840 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
1841 struct sk_buff *skb = skb_peek(&ppp->mrq);
1842 if (seq_before(ppp->minseq, skb->sequence))
1843 ppp->minseq = skb->sequence;
1844 }
1845
1846 /* Pull completed packets off the queue and receive them. */
1847 while ((skb = ppp_mp_reconstruct(ppp)))
1848 ppp_receive_nonmp_frame(ppp, skb);
1849
1850 return;
1851
1852 err:
1853 kfree_skb(skb);
1854 ppp_receive_error(ppp);
1855 }
1856
1857 /*
1858 * Insert a fragment on the MP reconstruction queue.
1859 * The queue is ordered by increasing sequence number.
1860 */
1861 static void
1862 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
1863 {
1864 struct sk_buff *p;
1865 struct sk_buff_head *list = &ppp->mrq;
1866 u32 seq = skb->sequence;
1867
1868 /* N.B. we don't need to lock the list lock because we have the
1869 ppp unit receive-side lock. */
1870 skb_queue_walk(list, p) {
1871 if (seq_before(seq, p->sequence))
1872 break;
1873 }
1874 __skb_queue_before(list, p, skb);
1875 }
1876
1877 /*
1878 * Reconstruct a packet from the MP fragment queue.
1879 * We go through increasing sequence numbers until we find a
1880 * complete packet, or we get to the sequence number for a fragment
1881 * which hasn't arrived but might still do so.
1882 */
1883 static struct sk_buff *
1884 ppp_mp_reconstruct(struct ppp *ppp)
1885 {
1886 u32 seq = ppp->nextseq;
1887 u32 minseq = ppp->minseq;
1888 struct sk_buff_head *list = &ppp->mrq;
1889 struct sk_buff *p, *next;
1890 struct sk_buff *head, *tail;
1891 struct sk_buff *skb = NULL;
1892 int lost = 0, len = 0;
1893
1894 if (ppp->mrru == 0) /* do nothing until mrru is set */
1895 return NULL;
1896 head = list->next;
1897 tail = NULL;
1898 for (p = head; p != (struct sk_buff *) list; p = next) {
1899 next = p->next;
1900 if (seq_before(p->sequence, seq)) {
1901 /* this can't happen, anyway ignore the skb */
1902 printk(KERN_ERR "ppp_mp_reconstruct bad seq %u < %u\n",
1903 p->sequence, seq);
1904 head = next;
1905 continue;
1906 }
1907 if (p->sequence != seq) {
1908 /* Fragment `seq' is missing. If it is after
1909 minseq, it might arrive later, so stop here. */
1910 if (seq_after(seq, minseq))
1911 break;
1912 /* Fragment `seq' is lost, keep going. */
1913 lost = 1;
1914 seq = seq_before(minseq, p->sequence)?
1915 minseq + 1: p->sequence;
1916 next = p;
1917 continue;
1918 }
1919
1920 /*
1921 * At this point we know that all the fragments from
1922 * ppp->nextseq to seq are either present or lost.
1923 * Also, there are no complete packets in the queue
1924 * that have no missing fragments and end before this
1925 * fragment.
1926 */
1927
1928 /* B bit set indicates this fragment starts a packet */
1929 if (p->BEbits & B) {
1930 head = p;
1931 lost = 0;
1932 len = 0;
1933 }
1934
1935 len += p->len;
1936
1937 /* Got a complete packet yet? */
1938 if (lost == 0 && (p->BEbits & E) && (head->BEbits & B)) {
1939 if (len > ppp->mrru + 2) {
1940 ++ppp->dev->stats.rx_length_errors;
1941 printk(KERN_DEBUG "PPP: reconstructed packet"
1942 " is too long (%d)\n", len);
1943 } else if (p == head) {
1944 /* fragment is complete packet - reuse skb */
1945 tail = p;
1946 skb = skb_get(p);
1947 break;
1948 } else if ((skb = dev_alloc_skb(len)) == NULL) {
1949 ++ppp->dev->stats.rx_missed_errors;
1950 printk(KERN_DEBUG "PPP: no memory for "
1951 "reconstructed packet");
1952 } else {
1953 tail = p;
1954 break;
1955 }
1956 ppp->nextseq = seq + 1;
1957 }
1958
1959 /*
1960 * If this is the ending fragment of a packet,
1961 * and we haven't found a complete valid packet yet,
1962 * we can discard up to and including this fragment.
1963 */
1964 if (p->BEbits & E)
1965 head = next;
1966
1967 ++seq;
1968 }
1969
1970 /* If we have a complete packet, copy it all into one skb. */
1971 if (tail != NULL) {
1972 /* If we have discarded any fragments,
1973 signal a receive error. */
1974 if (head->sequence != ppp->nextseq) {
1975 if (ppp->debug & 1)
1976 printk(KERN_DEBUG " missed pkts %u..%u\n",
1977 ppp->nextseq, head->sequence-1);
1978 ++ppp->dev->stats.rx_dropped;
1979 ppp_receive_error(ppp);
1980 }
1981
1982 if (head != tail)
1983 /* copy to a single skb */
1984 for (p = head; p != tail->next; p = p->next)
1985 skb_copy_bits(p, 0, skb_put(skb, p->len), p->len);
1986 ppp->nextseq = tail->sequence + 1;
1987 head = tail->next;
1988 }
1989
1990 /* Discard all the skbuffs that we have copied the data out of
1991 or that we can't use. */
1992 while ((p = list->next) != head) {
1993 __skb_unlink(p, list);
1994 kfree_skb(p);
1995 }
1996
1997 return skb;
1998 }
1999 #endif /* CONFIG_PPP_MULTILINK */
2000
2001 /*
2002 * Channel interface.
2003 */
2004
2005 /*
2006 * Create a new, unattached ppp channel.
2007 */
2008 int
2009 ppp_register_channel(struct ppp_channel *chan)
2010 {
2011 struct channel *pch;
2012
2013 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2014 if (!pch)
2015 return -ENOMEM;
2016 pch->ppp = NULL;
2017 pch->chan = chan;
2018 chan->ppp = pch;
2019 init_ppp_file(&pch->file, CHANNEL);
2020 pch->file.hdrlen = chan->hdrlen;
2021 #ifdef CONFIG_PPP_MULTILINK
2022 pch->lastseq = -1;
2023 #endif /* CONFIG_PPP_MULTILINK */
2024 init_rwsem(&pch->chan_sem);
2025 spin_lock_init(&pch->downl);
2026 rwlock_init(&pch->upl);
2027 spin_lock_bh(&all_channels_lock);
2028 pch->file.index = ++last_channel_index;
2029 list_add(&pch->list, &new_channels);
2030 atomic_inc(&channel_count);
2031 spin_unlock_bh(&all_channels_lock);
2032 return 0;
2033 }
2034
2035 /*
2036 * Return the index of a channel.
2037 */
2038 int ppp_channel_index(struct ppp_channel *chan)
2039 {
2040 struct channel *pch = chan->ppp;
2041
2042 if (pch)
2043 return pch->file.index;
2044 return -1;
2045 }
2046
2047 /*
2048 * Return the PPP unit number to which a channel is connected.
2049 */
2050 int ppp_unit_number(struct ppp_channel *chan)
2051 {
2052 struct channel *pch = chan->ppp;
2053 int unit = -1;
2054
2055 if (pch) {
2056 read_lock_bh(&pch->upl);
2057 if (pch->ppp)
2058 unit = pch->ppp->file.index;
2059 read_unlock_bh(&pch->upl);
2060 }
2061 return unit;
2062 }
2063
2064 /*
2065 * Disconnect a channel from the generic layer.
2066 * This must be called in process context.
2067 */
2068 void
2069 ppp_unregister_channel(struct ppp_channel *chan)
2070 {
2071 struct channel *pch = chan->ppp;
2072
2073 if (!pch)
2074 return; /* should never happen */
2075 chan->ppp = NULL;
2076
2077 /*
2078 * This ensures that we have returned from any calls into the
2079 * the channel's start_xmit or ioctl routine before we proceed.
2080 */
2081 down_write(&pch->chan_sem);
2082 spin_lock_bh(&pch->downl);
2083 pch->chan = NULL;
2084 spin_unlock_bh(&pch->downl);
2085 up_write(&pch->chan_sem);
2086 ppp_disconnect_channel(pch);
2087 spin_lock_bh(&all_channels_lock);
2088 list_del(&pch->list);
2089 spin_unlock_bh(&all_channels_lock);
2090 pch->file.dead = 1;
2091 wake_up_interruptible(&pch->file.rwait);
2092 if (atomic_dec_and_test(&pch->file.refcnt))
2093 ppp_destroy_channel(pch);
2094 }
2095
2096 /*
2097 * Callback from a channel when it can accept more to transmit.
2098 * This should be called at BH/softirq level, not interrupt level.
2099 */
2100 void
2101 ppp_output_wakeup(struct ppp_channel *chan)
2102 {
2103 struct channel *pch = chan->ppp;
2104
2105 if (!pch)
2106 return;
2107 ppp_channel_push(pch);
2108 }
2109
2110 /*
2111 * Compression control.
2112 */
2113
2114 /* Process the PPPIOCSCOMPRESS ioctl. */
2115 static int
2116 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2117 {
2118 int err;
2119 struct compressor *cp, *ocomp;
2120 struct ppp_option_data data;
2121 void *state, *ostate;
2122 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2123
2124 err = -EFAULT;
2125 if (copy_from_user(&data, (void __user *) arg, sizeof(data))
2126 || (data.length <= CCP_MAX_OPTION_LENGTH
2127 && copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2128 goto out;
2129 err = -EINVAL;
2130 if (data.length > CCP_MAX_OPTION_LENGTH
2131 || ccp_option[1] < 2 || ccp_option[1] > data.length)
2132 goto out;
2133
2134 cp = try_then_request_module(
2135 find_compressor(ccp_option[0]),
2136 "ppp-compress-%d", ccp_option[0]);
2137 if (!cp)
2138 goto out;
2139
2140 err = -ENOBUFS;
2141 if (data.transmit) {
2142 state = cp->comp_alloc(ccp_option, data.length);
2143 if (state) {
2144 ppp_xmit_lock(ppp);
2145 ppp->xstate &= ~SC_COMP_RUN;
2146 ocomp = ppp->xcomp;
2147 ostate = ppp->xc_state;
2148 ppp->xcomp = cp;
2149 ppp->xc_state = state;
2150 ppp_xmit_unlock(ppp);
2151 if (ostate) {
2152 ocomp->comp_free(ostate);
2153 module_put(ocomp->owner);
2154 }
2155 err = 0;
2156 } else
2157 module_put(cp->owner);
2158
2159 } else {
2160 state = cp->decomp_alloc(ccp_option, data.length);
2161 if (state) {
2162 ppp_recv_lock(ppp);
2163 ppp->rstate &= ~SC_DECOMP_RUN;
2164 ocomp = ppp->rcomp;
2165 ostate = ppp->rc_state;
2166 ppp->rcomp = cp;
2167 ppp->rc_state = state;
2168 ppp_recv_unlock(ppp);
2169 if (ostate) {
2170 ocomp->decomp_free(ostate);
2171 module_put(ocomp->owner);
2172 }
2173 err = 0;
2174 } else
2175 module_put(cp->owner);
2176 }
2177
2178 out:
2179 return err;
2180 }
2181
2182 /*
2183 * Look at a CCP packet and update our state accordingly.
2184 * We assume the caller has the xmit or recv path locked.
2185 */
2186 static void
2187 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2188 {
2189 unsigned char *dp;
2190 int len;
2191
2192 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2193 return; /* no header */
2194 dp = skb->data + 2;
2195
2196 switch (CCP_CODE(dp)) {
2197 case CCP_CONFREQ:
2198
2199 /* A ConfReq starts negotiation of compression
2200 * in one direction of transmission,
2201 * and hence brings it down...but which way?
2202 *
2203 * Remember:
2204 * A ConfReq indicates what the sender would like to receive
2205 */
2206 if(inbound)
2207 /* He is proposing what I should send */
2208 ppp->xstate &= ~SC_COMP_RUN;
2209 else
2210 /* I am proposing to what he should send */
2211 ppp->rstate &= ~SC_DECOMP_RUN;
2212
2213 break;
2214
2215 case CCP_TERMREQ:
2216 case CCP_TERMACK:
2217 /*
2218 * CCP is going down, both directions of transmission
2219 */
2220 ppp->rstate &= ~SC_DECOMP_RUN;
2221 ppp->xstate &= ~SC_COMP_RUN;
2222 break;
2223
2224 case CCP_CONFACK:
2225 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2226 break;
2227 len = CCP_LENGTH(dp);
2228 if (!pskb_may_pull(skb, len + 2))
2229 return; /* too short */
2230 dp += CCP_HDRLEN;
2231 len -= CCP_HDRLEN;
2232 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2233 break;
2234 if (inbound) {
2235 /* we will start receiving compressed packets */
2236 if (!ppp->rc_state)
2237 break;
2238 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2239 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2240 ppp->rstate |= SC_DECOMP_RUN;
2241 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2242 }
2243 } else {
2244 /* we will soon start sending compressed packets */
2245 if (!ppp->xc_state)
2246 break;
2247 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2248 ppp->file.index, 0, ppp->debug))
2249 ppp->xstate |= SC_COMP_RUN;
2250 }
2251 break;
2252
2253 case CCP_RESETACK:
2254 /* reset the [de]compressor */
2255 if ((ppp->flags & SC_CCP_UP) == 0)
2256 break;
2257 if (inbound) {
2258 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2259 ppp->rcomp->decomp_reset(ppp->rc_state);
2260 ppp->rstate &= ~SC_DC_ERROR;
2261 }
2262 } else {
2263 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2264 ppp->xcomp->comp_reset(ppp->xc_state);
2265 }
2266 break;
2267 }
2268 }
2269
2270 /* Free up compression resources. */
2271 static void
2272 ppp_ccp_closed(struct ppp *ppp)
2273 {
2274 void *xstate, *rstate;
2275 struct compressor *xcomp, *rcomp;
2276
2277 ppp_lock(ppp);
2278 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2279 ppp->xstate = 0;
2280 xcomp = ppp->xcomp;
2281 xstate = ppp->xc_state;
2282 ppp->xc_state = NULL;
2283 ppp->rstate = 0;
2284 rcomp = ppp->rcomp;
2285 rstate = ppp->rc_state;
2286 ppp->rc_state = NULL;
2287 ppp_unlock(ppp);
2288
2289 if (xstate) {
2290 xcomp->comp_free(xstate);
2291 module_put(xcomp->owner);
2292 }
2293 if (rstate) {
2294 rcomp->decomp_free(rstate);
2295 module_put(rcomp->owner);
2296 }
2297 }
2298
2299 /* List of compressors. */
2300 static LIST_HEAD(compressor_list);
2301 static DEFINE_SPINLOCK(compressor_list_lock);
2302
2303 struct compressor_entry {
2304 struct list_head list;
2305 struct compressor *comp;
2306 };
2307
2308 static struct compressor_entry *
2309 find_comp_entry(int proto)
2310 {
2311 struct compressor_entry *ce;
2312
2313 list_for_each_entry(ce, &compressor_list, list) {
2314 if (ce->comp->compress_proto == proto)
2315 return ce;
2316 }
2317 return NULL;
2318 }
2319
2320 /* Register a compressor */
2321 int
2322 ppp_register_compressor(struct compressor *cp)
2323 {
2324 struct compressor_entry *ce;
2325 int ret;
2326 spin_lock(&compressor_list_lock);
2327 ret = -EEXIST;
2328 if (find_comp_entry(cp->compress_proto))
2329 goto out;
2330 ret = -ENOMEM;
2331 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2332 if (!ce)
2333 goto out;
2334 ret = 0;
2335 ce->comp = cp;
2336 list_add(&ce->list, &compressor_list);
2337 out:
2338 spin_unlock(&compressor_list_lock);
2339 return ret;
2340 }
2341
2342 /* Unregister a compressor */
2343 void
2344 ppp_unregister_compressor(struct compressor *cp)
2345 {
2346 struct compressor_entry *ce;
2347
2348 spin_lock(&compressor_list_lock);
2349 ce = find_comp_entry(cp->compress_proto);
2350 if (ce && ce->comp == cp) {
2351 list_del(&ce->list);
2352 kfree(ce);
2353 }
2354 spin_unlock(&compressor_list_lock);
2355 }
2356
2357 /* Find a compressor. */
2358 static struct compressor *
2359 find_compressor(int type)
2360 {
2361 struct compressor_entry *ce;
2362 struct compressor *cp = NULL;
2363
2364 spin_lock(&compressor_list_lock);
2365 ce = find_comp_entry(type);
2366 if (ce) {
2367 cp = ce->comp;
2368 if (!try_module_get(cp->owner))
2369 cp = NULL;
2370 }
2371 spin_unlock(&compressor_list_lock);
2372 return cp;
2373 }
2374
2375 /*
2376 * Miscelleneous stuff.
2377 */
2378
2379 static void
2380 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2381 {
2382 struct slcompress *vj = ppp->vj;
2383
2384 memset(st, 0, sizeof(*st));
2385 st->p.ppp_ipackets = ppp->dev->stats.rx_packets;
2386 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2387 st->p.ppp_ibytes = ppp->dev->stats.rx_bytes;
2388 st->p.ppp_opackets = ppp->dev->stats.tx_packets;
2389 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2390 st->p.ppp_obytes = ppp->dev->stats.tx_bytes;
2391 if (!vj)
2392 return;
2393 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2394 st->vj.vjs_compressed = vj->sls_o_compressed;
2395 st->vj.vjs_searches = vj->sls_o_searches;
2396 st->vj.vjs_misses = vj->sls_o_misses;
2397 st->vj.vjs_errorin = vj->sls_i_error;
2398 st->vj.vjs_tossed = vj->sls_i_tossed;
2399 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2400 st->vj.vjs_compressedin = vj->sls_i_compressed;
2401 }
2402
2403 /*
2404 * Stuff for handling the lists of ppp units and channels
2405 * and for initialization.
2406 */
2407
2408 /*
2409 * Create a new ppp interface unit. Fails if it can't allocate memory
2410 * or if there is already a unit with the requested number.
2411 * unit == -1 means allocate a new number.
2412 */
2413 static struct ppp *
2414 ppp_create_interface(int unit, int *retp)
2415 {
2416 struct ppp *ppp;
2417 struct net_device *dev = NULL;
2418 int ret = -ENOMEM;
2419 int i;
2420
2421 ppp = kzalloc(sizeof(struct ppp), GFP_KERNEL);
2422 if (!ppp)
2423 goto out;
2424 dev = alloc_netdev(0, "", ppp_setup);
2425 if (!dev)
2426 goto out1;
2427
2428 ppp->mru = PPP_MRU;
2429 init_ppp_file(&ppp->file, INTERFACE);
2430 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2431 for (i = 0; i < NUM_NP; ++i)
2432 ppp->npmode[i] = NPMODE_PASS;
2433 INIT_LIST_HEAD(&ppp->channels);
2434 spin_lock_init(&ppp->rlock);
2435 spin_lock_init(&ppp->wlock);
2436 #ifdef CONFIG_PPP_MULTILINK
2437 ppp->minseq = -1;
2438 skb_queue_head_init(&ppp->mrq);
2439 #endif /* CONFIG_PPP_MULTILINK */
2440 ppp->dev = dev;
2441 dev->priv = ppp;
2442
2443 dev->hard_start_xmit = ppp_start_xmit;
2444
2445 ret = -EEXIST;
2446 mutex_lock(&all_ppp_mutex);
2447 if (unit < 0)
2448 unit = cardmap_find_first_free(all_ppp_units);
2449 else if (cardmap_get(all_ppp_units, unit) != NULL)
2450 goto out2; /* unit already exists */
2451
2452 /* Initialize the new ppp unit */
2453 ppp->file.index = unit;
2454 sprintf(dev->name, "ppp%d", unit);
2455
2456 ret = register_netdev(dev);
2457 if (ret != 0) {
2458 printk(KERN_ERR "PPP: couldn't register device %s (%d)\n",
2459 dev->name, ret);
2460 goto out2;
2461 }
2462
2463 atomic_inc(&ppp_unit_count);
2464 ret = cardmap_set(&all_ppp_units, unit, ppp);
2465 if (ret != 0)
2466 goto out3;
2467
2468 mutex_unlock(&all_ppp_mutex);
2469 *retp = 0;
2470 return ppp;
2471
2472 out3:
2473 atomic_dec(&ppp_unit_count);
2474 unregister_netdev(dev);
2475 out2:
2476 mutex_unlock(&all_ppp_mutex);
2477 free_netdev(dev);
2478 out1:
2479 kfree(ppp);
2480 out:
2481 *retp = ret;
2482 return NULL;
2483 }
2484
2485 /*
2486 * Initialize a ppp_file structure.
2487 */
2488 static void
2489 init_ppp_file(struct ppp_file *pf, int kind)
2490 {
2491 pf->kind = kind;
2492 skb_queue_head_init(&pf->xq);
2493 skb_queue_head_init(&pf->rq);
2494 atomic_set(&pf->refcnt, 1);
2495 init_waitqueue_head(&pf->rwait);
2496 }
2497
2498 /*
2499 * Take down a ppp interface unit - called when the owning file
2500 * (the one that created the unit) is closed or detached.
2501 */
2502 static void ppp_shutdown_interface(struct ppp *ppp)
2503 {
2504 struct net_device *dev;
2505
2506 mutex_lock(&all_ppp_mutex);
2507 ppp_lock(ppp);
2508 dev = ppp->dev;
2509 ppp->dev = NULL;
2510 ppp_unlock(ppp);
2511 /* This will call dev_close() for us. */
2512 if (dev) {
2513 unregister_netdev(dev);
2514 free_netdev(dev);
2515 }
2516 cardmap_set(&all_ppp_units, ppp->file.index, NULL);
2517 ppp->file.dead = 1;
2518 ppp->owner = NULL;
2519 wake_up_interruptible(&ppp->file.rwait);
2520 mutex_unlock(&all_ppp_mutex);
2521 }
2522
2523 /*
2524 * Free the memory used by a ppp unit. This is only called once
2525 * there are no channels connected to the unit and no file structs
2526 * that reference the unit.
2527 */
2528 static void ppp_destroy_interface(struct ppp *ppp)
2529 {
2530 atomic_dec(&ppp_unit_count);
2531
2532 if (!ppp->file.dead || ppp->n_channels) {
2533 /* "can't happen" */
2534 printk(KERN_ERR "ppp: destroying ppp struct %p but dead=%d "
2535 "n_channels=%d !\n", ppp, ppp->file.dead,
2536 ppp->n_channels);
2537 return;
2538 }
2539
2540 ppp_ccp_closed(ppp);
2541 if (ppp->vj) {
2542 slhc_free(ppp->vj);
2543 ppp->vj = NULL;
2544 }
2545 skb_queue_purge(&ppp->file.xq);
2546 skb_queue_purge(&ppp->file.rq);
2547 #ifdef CONFIG_PPP_MULTILINK
2548 skb_queue_purge(&ppp->mrq);
2549 #endif /* CONFIG_PPP_MULTILINK */
2550 #ifdef CONFIG_PPP_FILTER
2551 kfree(ppp->pass_filter);
2552 ppp->pass_filter = NULL;
2553 kfree(ppp->active_filter);
2554 ppp->active_filter = NULL;
2555 #endif /* CONFIG_PPP_FILTER */
2556
2557 if (ppp->xmit_pending)
2558 kfree_skb(ppp->xmit_pending);
2559
2560 kfree(ppp);
2561 }
2562
2563 /*
2564 * Locate an existing ppp unit.
2565 * The caller should have locked the all_ppp_mutex.
2566 */
2567 static struct ppp *
2568 ppp_find_unit(int unit)
2569 {
2570 return cardmap_get(all_ppp_units, unit);
2571 }
2572
2573 /*
2574 * Locate an existing ppp channel.
2575 * The caller should have locked the all_channels_lock.
2576 * First we look in the new_channels list, then in the
2577 * all_channels list. If found in the new_channels list,
2578 * we move it to the all_channels list. This is for speed
2579 * when we have a lot of channels in use.
2580 */
2581 static struct channel *
2582 ppp_find_channel(int unit)
2583 {
2584 struct channel *pch;
2585
2586 list_for_each_entry(pch, &new_channels, list) {
2587 if (pch->file.index == unit) {
2588 list_move(&pch->list, &all_channels);
2589 return pch;
2590 }
2591 }
2592 list_for_each_entry(pch, &all_channels, list) {
2593 if (pch->file.index == unit)
2594 return pch;
2595 }
2596 return NULL;
2597 }
2598
2599 /*
2600 * Connect a PPP channel to a PPP interface unit.
2601 */
2602 static int
2603 ppp_connect_channel(struct channel *pch, int unit)
2604 {
2605 struct ppp *ppp;
2606 int ret = -ENXIO;
2607 int hdrlen;
2608
2609 mutex_lock(&all_ppp_mutex);
2610 ppp = ppp_find_unit(unit);
2611 if (!ppp)
2612 goto out;
2613 write_lock_bh(&pch->upl);
2614 ret = -EINVAL;
2615 if (pch->ppp)
2616 goto outl;
2617
2618 ppp_lock(ppp);
2619 if (pch->file.hdrlen > ppp->file.hdrlen)
2620 ppp->file.hdrlen = pch->file.hdrlen;
2621 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2622 if (ppp->dev && hdrlen > ppp->dev->hard_header_len)
2623 ppp->dev->hard_header_len = hdrlen;
2624 list_add_tail(&pch->clist, &ppp->channels);
2625 ++ppp->n_channels;
2626 pch->ppp = ppp;
2627 atomic_inc(&ppp->file.refcnt);
2628 ppp_unlock(ppp);
2629 ret = 0;
2630
2631 outl:
2632 write_unlock_bh(&pch->upl);
2633 out:
2634 mutex_unlock(&all_ppp_mutex);
2635 return ret;
2636 }
2637
2638 /*
2639 * Disconnect a channel from its ppp unit.
2640 */
2641 static int
2642 ppp_disconnect_channel(struct channel *pch)
2643 {
2644 struct ppp *ppp;
2645 int err = -EINVAL;
2646
2647 write_lock_bh(&pch->upl);
2648 ppp = pch->ppp;
2649 pch->ppp = NULL;
2650 write_unlock_bh(&pch->upl);
2651 if (ppp) {
2652 /* remove it from the ppp unit's list */
2653 ppp_lock(ppp);
2654 list_del(&pch->clist);
2655 if (--ppp->n_channels == 0)
2656 wake_up_interruptible(&ppp->file.rwait);
2657 ppp_unlock(ppp);
2658 if (atomic_dec_and_test(&ppp->file.refcnt))
2659 ppp_destroy_interface(ppp);
2660 err = 0;
2661 }
2662 return err;
2663 }
2664
2665 /*
2666 * Free up the resources used by a ppp channel.
2667 */
2668 static void ppp_destroy_channel(struct channel *pch)
2669 {
2670 atomic_dec(&channel_count);
2671
2672 if (!pch->file.dead) {
2673 /* "can't happen" */
2674 printk(KERN_ERR "ppp: destroying undead channel %p !\n",
2675 pch);
2676 return;
2677 }
2678 skb_queue_purge(&pch->file.xq);
2679 skb_queue_purge(&pch->file.rq);
2680 kfree(pch);
2681 }
2682
2683 static void __exit ppp_cleanup(void)
2684 {
2685 /* should never happen */
2686 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2687 printk(KERN_ERR "PPP: removing module but units remain!\n");
2688 cardmap_destroy(&all_ppp_units);
2689 unregister_chrdev(PPP_MAJOR, "ppp");
2690 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
2691 class_destroy(ppp_class);
2692 }
2693
2694 /*
2695 * Cardmap implementation.
2696 */
2697 static void *cardmap_get(struct cardmap *map, unsigned int nr)
2698 {
2699 struct cardmap *p;
2700 int i;
2701
2702 for (p = map; p != NULL; ) {
2703 if ((i = nr >> p->shift) >= CARDMAP_WIDTH)
2704 return NULL;
2705 if (p->shift == 0)
2706 return p->ptr[i];
2707 nr &= ~(CARDMAP_MASK << p->shift);
2708 p = p->ptr[i];
2709 }
2710 return NULL;
2711 }
2712
2713 static int cardmap_set(struct cardmap **pmap, unsigned int nr, void *ptr)
2714 {
2715 struct cardmap *p;
2716 int i;
2717
2718 p = *pmap;
2719 if (p == NULL || (nr >> p->shift) >= CARDMAP_WIDTH) {
2720 do {
2721 /* need a new top level */
2722 struct cardmap *np = kzalloc(sizeof(*np), GFP_KERNEL);
2723 if (!np)
2724 goto enomem;
2725 np->ptr[0] = p;
2726 if (p != NULL) {
2727 np->shift = p->shift + CARDMAP_ORDER;
2728 p->parent = np;
2729 } else
2730 np->shift = 0;
2731 p = np;
2732 } while ((nr >> p->shift) >= CARDMAP_WIDTH);
2733 *pmap = p;
2734 }
2735 while (p->shift > 0) {
2736 i = (nr >> p->shift) & CARDMAP_MASK;
2737 if (p->ptr[i] == NULL) {
2738 struct cardmap *np = kzalloc(sizeof(*np), GFP_KERNEL);
2739 if (!np)
2740 goto enomem;
2741 np->shift = p->shift - CARDMAP_ORDER;
2742 np->parent = p;
2743 p->ptr[i] = np;
2744 }
2745 if (ptr == NULL)
2746 clear_bit(i, &p->inuse);
2747 p = p->ptr[i];
2748 }
2749 i = nr & CARDMAP_MASK;
2750 p->ptr[i] = ptr;
2751 if (ptr != NULL)
2752 set_bit(i, &p->inuse);
2753 else
2754 clear_bit(i, &p->inuse);
2755 return 0;
2756 enomem:
2757 return -ENOMEM;
2758 }
2759
2760 static unsigned int cardmap_find_first_free(struct cardmap *map)
2761 {
2762 struct cardmap *p;
2763 unsigned int nr = 0;
2764 int i;
2765
2766 if ((p = map) == NULL)
2767 return 0;
2768 for (;;) {
2769 i = find_first_zero_bit(&p->inuse, CARDMAP_WIDTH);
2770 if (i >= CARDMAP_WIDTH) {
2771 if (p->parent == NULL)
2772 return CARDMAP_WIDTH << p->shift;
2773 p = p->parent;
2774 i = (nr >> p->shift) & CARDMAP_MASK;
2775 set_bit(i, &p->inuse);
2776 continue;
2777 }
2778 nr = (nr & (~CARDMAP_MASK << p->shift)) | (i << p->shift);
2779 if (p->shift == 0 || p->ptr[i] == NULL)
2780 return nr;
2781 p = p->ptr[i];
2782 }
2783 }
2784
2785 static void cardmap_destroy(struct cardmap **pmap)
2786 {
2787 struct cardmap *p, *np;
2788 int i;
2789
2790 for (p = *pmap; p != NULL; p = np) {
2791 if (p->shift != 0) {
2792 for (i = 0; i < CARDMAP_WIDTH; ++i)
2793 if (p->ptr[i] != NULL)
2794 break;
2795 if (i < CARDMAP_WIDTH) {
2796 np = p->ptr[i];
2797 p->ptr[i] = NULL;
2798 continue;
2799 }
2800 }
2801 np = p->parent;
2802 kfree(p);
2803 }
2804 *pmap = NULL;
2805 }
2806
2807 /* Module/initialization stuff */
2808
2809 module_init(ppp_init);
2810 module_exit(ppp_cleanup);
2811
2812 EXPORT_SYMBOL(ppp_register_channel);
2813 EXPORT_SYMBOL(ppp_unregister_channel);
2814 EXPORT_SYMBOL(ppp_channel_index);
2815 EXPORT_SYMBOL(ppp_unit_number);
2816 EXPORT_SYMBOL(ppp_input);
2817 EXPORT_SYMBOL(ppp_input_error);
2818 EXPORT_SYMBOL(ppp_output_wakeup);
2819 EXPORT_SYMBOL(ppp_register_compressor);
2820 EXPORT_SYMBOL(ppp_unregister_compressor);
2821 MODULE_LICENSE("GPL");
2822 MODULE_ALIAS_CHARDEV_MAJOR(PPP_MAJOR);
2823 MODULE_ALIAS("/dev/ppp");
Support for the Chinese Samsung S3C2440 based development boards