?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
dm raid1: fix do_failures
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / net / ppp_generic.c
blob7e857e938adb582ae432b26d35114e8099d51eb2
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 void ppp_setup(struct net_device *dev)
975 {
976 dev->hard_header_len = PPP_HDRLEN;
977 dev->mtu = PPP_MTU;
978 dev->addr_len = 0;
979 dev->tx_queue_len = 3;
980 dev->type = ARPHRD_PPP;
981 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
982 }
983
984 /*
985 * Transmit-side routines.
986 */
987
988 /*
989 * Called to do any work queued up on the transmit side
990 * that can now be done.
991 */
992 static void
993 ppp_xmit_process(struct ppp *ppp)
994 {
995 struct sk_buff *skb;
996
997 ppp_xmit_lock(ppp);
998 if (ppp->dev) {
999 ppp_push(ppp);
1000 while (!ppp->xmit_pending
1001 && (skb = skb_dequeue(&ppp->file.xq)))
1002 ppp_send_frame(ppp, skb);
1003 /* If there's no work left to do, tell the core net
1004 code that we can accept some more. */
1005 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1006 netif_wake_queue(ppp->dev);
1007 }
1008 ppp_xmit_unlock(ppp);
1009 }
1010
1011 static inline struct sk_buff *
1012 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1013 {
1014 struct sk_buff *new_skb;
1015 int len;
1016 int new_skb_size = ppp->dev->mtu +
1017 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1018 int compressor_skb_size = ppp->dev->mtu +
1019 ppp->xcomp->comp_extra + PPP_HDRLEN;
1020 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1021 if (!new_skb) {
1022 if (net_ratelimit())
1023 printk(KERN_ERR "PPP: no memory (comp pkt)\n");
1024 return NULL;
1025 }
1026 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1027 skb_reserve(new_skb,
1028 ppp->dev->hard_header_len - PPP_HDRLEN);
1029
1030 /* compressor still expects A/C bytes in hdr */
1031 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1032 new_skb->data, skb->len + 2,
1033 compressor_skb_size);
1034 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1035 kfree_skb(skb);
1036 skb = new_skb;
1037 skb_put(skb, len);
1038 skb_pull(skb, 2); /* pull off A/C bytes */
1039 } else if (len == 0) {
1040 /* didn't compress, or CCP not up yet */
1041 kfree_skb(new_skb);
1042 new_skb = skb;
1043 } else {
1044 /*
1045 * (len < 0)
1046 * MPPE requires that we do not send unencrypted
1047 * frames. The compressor will return -1 if we
1048 * should drop the frame. We cannot simply test
1049 * the compress_proto because MPPE and MPPC share
1050 * the same number.
1051 */
1052 if (net_ratelimit())
1053 printk(KERN_ERR "ppp: compressor dropped pkt\n");
1054 kfree_skb(skb);
1055 kfree_skb(new_skb);
1056 new_skb = NULL;
1057 }
1058 return new_skb;
1059 }
1060
1061 /*
1062 * Compress and send a frame.
1063 * The caller should have locked the xmit path,
1064 * and xmit_pending should be 0.
1065 */
1066 static void
1067 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1068 {
1069 int proto = PPP_PROTO(skb);
1070 struct sk_buff *new_skb;
1071 int len;
1072 unsigned char *cp;
1073
1074 if (proto < 0x8000) {
1075 #ifdef CONFIG_PPP_FILTER
1076 /* check if we should pass this packet */
1077 /* the filter instructions are constructed assuming
1078 a four-byte PPP header on each packet */
1079 *skb_push(skb, 2) = 1;
1080 if (ppp->pass_filter
1081 && sk_run_filter(skb, ppp->pass_filter,
1082 ppp->pass_len) == 0) {
1083 if (ppp->debug & 1)
1084 printk(KERN_DEBUG "PPP: outbound frame not passed\n");
1085 kfree_skb(skb);
1086 return;
1087 }
1088 /* if this packet passes the active filter, record the time */
1089 if (!(ppp->active_filter
1090 && sk_run_filter(skb, ppp->active_filter,
1091 ppp->active_len) == 0))
1092 ppp->last_xmit = jiffies;
1093 skb_pull(skb, 2);
1094 #else
1095 /* for data packets, record the time */
1096 ppp->last_xmit = jiffies;
1097 #endif /* CONFIG_PPP_FILTER */
1098 }
1099
1100 ++ppp->dev->stats.tx_packets;
1101 ppp->dev->stats.tx_bytes += skb->len - 2;
1102
1103 switch (proto) {
1104 case PPP_IP:
1105 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1106 break;
1107 /* try to do VJ TCP header compression */
1108 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1109 GFP_ATOMIC);
1110 if (!new_skb) {
1111 printk(KERN_ERR "PPP: no memory (VJ comp pkt)\n");
1112 goto drop;
1113 }
1114 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1115 cp = skb->data + 2;
1116 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1117 new_skb->data + 2, &cp,
1118 !(ppp->flags & SC_NO_TCP_CCID));
1119 if (cp == skb->data + 2) {
1120 /* didn't compress */
1121 kfree_skb(new_skb);
1122 } else {
1123 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1124 proto = PPP_VJC_COMP;
1125 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1126 } else {
1127 proto = PPP_VJC_UNCOMP;
1128 cp[0] = skb->data[2];
1129 }
1130 kfree_skb(skb);
1131 skb = new_skb;
1132 cp = skb_put(skb, len + 2);
1133 cp[0] = 0;
1134 cp[1] = proto;
1135 }
1136 break;
1137
1138 case PPP_CCP:
1139 /* peek at outbound CCP frames */
1140 ppp_ccp_peek(ppp, skb, 0);
1141 break;
1142 }
1143
1144 /* try to do packet compression */
1145 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state
1146 && proto != PPP_LCP && proto != PPP_CCP) {
1147 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1148 if (net_ratelimit())
1149 printk(KERN_ERR "ppp: compression required but down - pkt dropped.\n");
1150 goto drop;
1151 }
1152 skb = pad_compress_skb(ppp, skb);
1153 if (!skb)
1154 goto drop;
1155 }
1156
1157 /*
1158 * If we are waiting for traffic (demand dialling),
1159 * queue it up for pppd to receive.
1160 */
1161 if (ppp->flags & SC_LOOP_TRAFFIC) {
1162 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1163 goto drop;
1164 skb_queue_tail(&ppp->file.rq, skb);
1165 wake_up_interruptible(&ppp->file.rwait);
1166 return;
1167 }
1168
1169 ppp->xmit_pending = skb;
1170 ppp_push(ppp);
1171 return;
1172
1173 drop:
1174 if (skb)
1175 kfree_skb(skb);
1176 ++ppp->dev->stats.tx_errors;
1177 }
1178
1179 /*
1180 * Try to send the frame in xmit_pending.
1181 * The caller should have the xmit path locked.
1182 */
1183 static void
1184 ppp_push(struct ppp *ppp)
1185 {
1186 struct list_head *list;
1187 struct channel *pch;
1188 struct sk_buff *skb = ppp->xmit_pending;
1189
1190 if (!skb)
1191 return;
1192
1193 list = &ppp->channels;
1194 if (list_empty(list)) {
1195 /* nowhere to send the packet, just drop it */
1196 ppp->xmit_pending = NULL;
1197 kfree_skb(skb);
1198 return;
1199 }
1200
1201 if ((ppp->flags & SC_MULTILINK) == 0) {
1202 /* not doing multilink: send it down the first channel */
1203 list = list->next;
1204 pch = list_entry(list, struct channel, clist);
1205
1206 spin_lock_bh(&pch->downl);
1207 if (pch->chan) {
1208 if (pch->chan->ops->start_xmit(pch->chan, skb))
1209 ppp->xmit_pending = NULL;
1210 } else {
1211 /* channel got unregistered */
1212 kfree_skb(skb);
1213 ppp->xmit_pending = NULL;
1214 }
1215 spin_unlock_bh(&pch->downl);
1216 return;
1217 }
1218
1219 #ifdef CONFIG_PPP_MULTILINK
1220 /* Multilink: fragment the packet over as many links
1221 as can take the packet at the moment. */
1222 if (!ppp_mp_explode(ppp, skb))
1223 return;
1224 #endif /* CONFIG_PPP_MULTILINK */
1225
1226 ppp->xmit_pending = NULL;
1227 kfree_skb(skb);
1228 }
1229
1230 #ifdef CONFIG_PPP_MULTILINK
1231 /*
1232 * Divide a packet to be transmitted into fragments and
1233 * send them out the individual links.
1234 */
1235 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1236 {
1237 int len, fragsize;
1238 int i, bits, hdrlen, mtu;
1239 int flen;
1240 int navail, nfree;
1241 int nbigger;
1242 unsigned char *p, *q;
1243 struct list_head *list;
1244 struct channel *pch;
1245 struct sk_buff *frag;
1246 struct ppp_channel *chan;
1247
1248 nfree = 0; /* # channels which have no packet already queued */
1249 navail = 0; /* total # of usable channels (not deregistered) */
1250 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1251 i = 0;
1252 list_for_each_entry(pch, &ppp->channels, clist) {
1253 navail += pch->avail = (pch->chan != NULL);
1254 if (pch->avail) {
1255 if (skb_queue_empty(&pch->file.xq) ||
1256 !pch->had_frag) {
1257 pch->avail = 2;
1258 ++nfree;
1259 }
1260 if (!pch->had_frag && i < ppp->nxchan)
1261 ppp->nxchan = i;
1262 }
1263 ++i;
1264 }
1265
1266 /*
1267 * Don't start sending this packet unless at least half of
1268 * the channels are free. This gives much better TCP
1269 * performance if we have a lot of channels.
1270 */
1271 if (nfree == 0 || nfree < navail / 2)
1272 return 0; /* can't take now, leave it in xmit_pending */
1273
1274 /* Do protocol field compression (XXX this should be optional) */
1275 p = skb->data;
1276 len = skb->len;
1277 if (*p == 0) {
1278 ++p;
1279 --len;
1280 }
1281
1282 /*
1283 * Decide on fragment size.
1284 * We create a fragment for each free channel regardless of
1285 * how small they are (i.e. even 0 length) in order to minimize
1286 * the time that it will take to detect when a channel drops
1287 * a fragment.
1288 */
1289 fragsize = len;
1290 if (nfree > 1)
1291 fragsize = DIV_ROUND_UP(fragsize, nfree);
1292 /* nbigger channels get fragsize bytes, the rest get fragsize-1,
1293 except if nbigger==0, then they all get fragsize. */
1294 nbigger = len % nfree;
1295
1296 /* skip to the channel after the one we last used
1297 and start at that one */
1298 list = &ppp->channels;
1299 for (i = 0; i < ppp->nxchan; ++i) {
1300 list = list->next;
1301 if (list == &ppp->channels) {
1302 i = 0;
1303 break;
1304 }
1305 }
1306
1307 /* create a fragment for each channel */
1308 bits = B;
1309 while (nfree > 0 || len > 0) {
1310 list = list->next;
1311 if (list == &ppp->channels) {
1312 i = 0;
1313 continue;
1314 }
1315 pch = list_entry(list, struct channel, clist);
1316 ++i;
1317 if (!pch->avail)
1318 continue;
1319
1320 /*
1321 * Skip this channel if it has a fragment pending already and
1322 * we haven't given a fragment to all of the free channels.
1323 */
1324 if (pch->avail == 1) {
1325 if (nfree > 0)
1326 continue;
1327 } else {
1328 --nfree;
1329 pch->avail = 1;
1330 }
1331
1332 /* check the channel's mtu and whether it is still attached. */
1333 spin_lock_bh(&pch->downl);
1334 if (pch->chan == NULL) {
1335 /* can't use this channel, it's being deregistered */
1336 spin_unlock_bh(&pch->downl);
1337 pch->avail = 0;
1338 if (--navail == 0)
1339 break;
1340 continue;
1341 }
1342
1343 /*
1344 * Create a fragment for this channel of
1345 * min(max(mtu+2-hdrlen, 4), fragsize, len) bytes.
1346 * If mtu+2-hdrlen < 4, that is a ridiculously small
1347 * MTU, so we use mtu = 2 + hdrlen.
1348 */
1349 if (fragsize > len)
1350 fragsize = len;
1351 flen = fragsize;
1352 mtu = pch->chan->mtu + 2 - hdrlen;
1353 if (mtu < 4)
1354 mtu = 4;
1355 if (flen > mtu)
1356 flen = mtu;
1357 if (flen == len && nfree == 0)
1358 bits |= E;
1359 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1360 if (!frag)
1361 goto noskb;
1362 q = skb_put(frag, flen + hdrlen);
1363
1364 /* make the MP header */
1365 q[0] = PPP_MP >> 8;
1366 q[1] = PPP_MP;
1367 if (ppp->flags & SC_MP_XSHORTSEQ) {
1368 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1369 q[3] = ppp->nxseq;
1370 } else {
1371 q[2] = bits;
1372 q[3] = ppp->nxseq >> 16;
1373 q[4] = ppp->nxseq >> 8;
1374 q[5] = ppp->nxseq;
1375 }
1376
1377 /*
1378 * Copy the data in.
1379 * Unfortunately there is a bug in older versions of
1380 * the Linux PPP multilink reconstruction code where it
1381 * drops 0-length fragments. Therefore we make sure the
1382 * fragment has at least one byte of data. Any bytes
1383 * we add in this situation will end up as padding on the
1384 * end of the reconstructed packet.
1385 */
1386 if (flen == 0)
1387 *skb_put(frag, 1) = 0;
1388 else
1389 memcpy(q + hdrlen, p, flen);
1390
1391 /* try to send it down the channel */
1392 chan = pch->chan;
1393 if (!skb_queue_empty(&pch->file.xq) ||
1394 !chan->ops->start_xmit(chan, frag))
1395 skb_queue_tail(&pch->file.xq, frag);
1396 pch->had_frag = 1;
1397 p += flen;
1398 len -= flen;
1399 ++ppp->nxseq;
1400 bits = 0;
1401 spin_unlock_bh(&pch->downl);
1402
1403 if (--nbigger == 0 && fragsize > 0)
1404 --fragsize;
1405 }
1406 ppp->nxchan = i;
1407
1408 return 1;
1409
1410 noskb:
1411 spin_unlock_bh(&pch->downl);
1412 if (ppp->debug & 1)
1413 printk(KERN_ERR "PPP: no memory (fragment)\n");
1414 ++ppp->dev->stats.tx_errors;
1415 ++ppp->nxseq;
1416 return 1; /* abandon the frame */
1417 }
1418 #endif /* CONFIG_PPP_MULTILINK */
1419
1420 /*
1421 * Try to send data out on a channel.
1422 */
1423 static void
1424 ppp_channel_push(struct channel *pch)
1425 {
1426 struct sk_buff *skb;
1427 struct ppp *ppp;
1428
1429 spin_lock_bh(&pch->downl);
1430 if (pch->chan) {
1431 while (!skb_queue_empty(&pch->file.xq)) {
1432 skb = skb_dequeue(&pch->file.xq);
1433 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1434 /* put the packet back and try again later */
1435 skb_queue_head(&pch->file.xq, skb);
1436 break;
1437 }
1438 }
1439 } else {
1440 /* channel got deregistered */
1441 skb_queue_purge(&pch->file.xq);
1442 }
1443 spin_unlock_bh(&pch->downl);
1444 /* see if there is anything from the attached unit to be sent */
1445 if (skb_queue_empty(&pch->file.xq)) {
1446 read_lock_bh(&pch->upl);
1447 ppp = pch->ppp;
1448 if (ppp)
1449 ppp_xmit_process(ppp);
1450 read_unlock_bh(&pch->upl);
1451 }
1452 }
1453
1454 /*
1455 * Receive-side routines.
1456 */
1457
1458 /* misuse a few fields of the skb for MP reconstruction */
1459 #define sequence priority
1460 #define BEbits cb[0]
1461
1462 static inline void
1463 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1464 {
1465 ppp_recv_lock(ppp);
1466 /* ppp->dev == 0 means interface is closing down */
1467 if (ppp->dev)
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 struct net_device *dev;
2502
2503 mutex_lock(&all_ppp_mutex);
2504 ppp_lock(ppp);
2505 dev = ppp->dev;
2506 ppp->dev = NULL;
2507 ppp_unlock(ppp);
2508 /* This will call dev_close() for us. */
2509 if (dev) {
2510 unregister_netdev(dev);
2511 free_netdev(dev);
2512 }
2513 cardmap_set(&all_ppp_units, ppp->file.index, NULL);
2514 ppp->file.dead = 1;
2515 ppp->owner = NULL;
2516 wake_up_interruptible(&ppp->file.rwait);
2517 mutex_unlock(&all_ppp_mutex);
2518 }
2519
2520 /*
2521 * Free the memory used by a ppp unit. This is only called once
2522 * there are no channels connected to the unit and no file structs
2523 * that reference the unit.
2524 */
2525 static void ppp_destroy_interface(struct ppp *ppp)
2526 {
2527 atomic_dec(&ppp_unit_count);
2528
2529 if (!ppp->file.dead || ppp->n_channels) {
2530 /* "can't happen" */
2531 printk(KERN_ERR "ppp: destroying ppp struct %p but dead=%d "
2532 "n_channels=%d !\n", ppp, ppp->file.dead,
2533 ppp->n_channels);
2534 return;
2535 }
2536
2537 ppp_ccp_closed(ppp);
2538 if (ppp->vj) {
2539 slhc_free(ppp->vj);
2540 ppp->vj = NULL;
2541 }
2542 skb_queue_purge(&ppp->file.xq);
2543 skb_queue_purge(&ppp->file.rq);
2544 #ifdef CONFIG_PPP_MULTILINK
2545 skb_queue_purge(&ppp->mrq);
2546 #endif /* CONFIG_PPP_MULTILINK */
2547 #ifdef CONFIG_PPP_FILTER
2548 kfree(ppp->pass_filter);
2549 ppp->pass_filter = NULL;
2550 kfree(ppp->active_filter);
2551 ppp->active_filter = NULL;
2552 #endif /* CONFIG_PPP_FILTER */
2553
2554 if (ppp->xmit_pending)
2555 kfree_skb(ppp->xmit_pending);
2556
2557 kfree(ppp);
2558 }
2559
2560 /*
2561 * Locate an existing ppp unit.
2562 * The caller should have locked the all_ppp_mutex.
2563 */
2564 static struct ppp *
2565 ppp_find_unit(int unit)
2566 {
2567 return cardmap_get(all_ppp_units, unit);
2568 }
2569
2570 /*
2571 * Locate an existing ppp channel.
2572 * The caller should have locked the all_channels_lock.
2573 * First we look in the new_channels list, then in the
2574 * all_channels list. If found in the new_channels list,
2575 * we move it to the all_channels list. This is for speed
2576 * when we have a lot of channels in use.
2577 */
2578 static struct channel *
2579 ppp_find_channel(int unit)
2580 {
2581 struct channel *pch;
2582
2583 list_for_each_entry(pch, &new_channels, list) {
2584 if (pch->file.index == unit) {
2585 list_move(&pch->list, &all_channels);
2586 return pch;
2587 }
2588 }
2589 list_for_each_entry(pch, &all_channels, list) {
2590 if (pch->file.index == unit)
2591 return pch;
2592 }
2593 return NULL;
2594 }
2595
2596 /*
2597 * Connect a PPP channel to a PPP interface unit.
2598 */
2599 static int
2600 ppp_connect_channel(struct channel *pch, int unit)
2601 {
2602 struct ppp *ppp;
2603 int ret = -ENXIO;
2604 int hdrlen;
2605
2606 mutex_lock(&all_ppp_mutex);
2607 ppp = ppp_find_unit(unit);
2608 if (!ppp)
2609 goto out;
2610 write_lock_bh(&pch->upl);
2611 ret = -EINVAL;
2612 if (pch->ppp)
2613 goto outl;
2614
2615 ppp_lock(ppp);
2616 if (pch->file.hdrlen > ppp->file.hdrlen)
2617 ppp->file.hdrlen = pch->file.hdrlen;
2618 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2619 if (ppp->dev && hdrlen > ppp->dev->hard_header_len)
2620 ppp->dev->hard_header_len = hdrlen;
2621 list_add_tail(&pch->clist, &ppp->channels);
2622 ++ppp->n_channels;
2623 pch->ppp = ppp;
2624 atomic_inc(&ppp->file.refcnt);
2625 ppp_unlock(ppp);
2626 ret = 0;
2627
2628 outl:
2629 write_unlock_bh(&pch->upl);
2630 out:
2631 mutex_unlock(&all_ppp_mutex);
2632 return ret;
2633 }
2634
2635 /*
2636 * Disconnect a channel from its ppp unit.
2637 */
2638 static int
2639 ppp_disconnect_channel(struct channel *pch)
2640 {
2641 struct ppp *ppp;
2642 int err = -EINVAL;
2643
2644 write_lock_bh(&pch->upl);
2645 ppp = pch->ppp;
2646 pch->ppp = NULL;
2647 write_unlock_bh(&pch->upl);
2648 if (ppp) {
2649 /* remove it from the ppp unit's list */
2650 ppp_lock(ppp);
2651 list_del(&pch->clist);
2652 if (--ppp->n_channels == 0)
2653 wake_up_interruptible(&ppp->file.rwait);
2654 ppp_unlock(ppp);
2655 if (atomic_dec_and_test(&ppp->file.refcnt))
2656 ppp_destroy_interface(ppp);
2657 err = 0;
2658 }
2659 return err;
2660 }
2661
2662 /*
2663 * Free up the resources used by a ppp channel.
2664 */
2665 static void ppp_destroy_channel(struct channel *pch)
2666 {
2667 atomic_dec(&channel_count);
2668
2669 if (!pch->file.dead) {
2670 /* "can't happen" */
2671 printk(KERN_ERR "ppp: destroying undead channel %p !\n",
2672 pch);
2673 return;
2674 }
2675 skb_queue_purge(&pch->file.xq);
2676 skb_queue_purge(&pch->file.rq);
2677 kfree(pch);
2678 }
2679
2680 static void __exit ppp_cleanup(void)
2681 {
2682 /* should never happen */
2683 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2684 printk(KERN_ERR "PPP: removing module but units remain!\n");
2685 cardmap_destroy(&all_ppp_units);
2686 unregister_chrdev(PPP_MAJOR, "ppp");
2687 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
2688 class_destroy(ppp_class);
2689 }
2690
2691 /*
2692 * Cardmap implementation.
2693 */
2694 static void *cardmap_get(struct cardmap *map, unsigned int nr)
2695 {
2696 struct cardmap *p;
2697 int i;
2698
2699 for (p = map; p != NULL; ) {
2700 if ((i = nr >> p->shift) >= CARDMAP_WIDTH)
2701 return NULL;
2702 if (p->shift == 0)
2703 return p->ptr[i];
2704 nr &= ~(CARDMAP_MASK << p->shift);
2705 p = p->ptr[i];
2706 }
2707 return NULL;
2708 }
2709
2710 static int cardmap_set(struct cardmap **pmap, unsigned int nr, void *ptr)
2711 {
2712 struct cardmap *p;
2713 int i;
2714
2715 p = *pmap;
2716 if (p == NULL || (nr >> p->shift) >= CARDMAP_WIDTH) {
2717 do {
2718 /* need a new top level */
2719 struct cardmap *np = kzalloc(sizeof(*np), GFP_KERNEL);
2720 if (!np)
2721 goto enomem;
2722 np->ptr[0] = p;
2723 if (p != NULL) {
2724 np->shift = p->shift + CARDMAP_ORDER;
2725 p->parent = np;
2726 } else
2727 np->shift = 0;
2728 p = np;
2729 } while ((nr >> p->shift) >= CARDMAP_WIDTH);
2730 *pmap = p;
2731 }
2732 while (p->shift > 0) {
2733 i = (nr >> p->shift) & CARDMAP_MASK;
2734 if (p->ptr[i] == NULL) {
2735 struct cardmap *np = kzalloc(sizeof(*np), GFP_KERNEL);
2736 if (!np)
2737 goto enomem;
2738 np->shift = p->shift - CARDMAP_ORDER;
2739 np->parent = p;
2740 p->ptr[i] = np;
2741 }
2742 if (ptr == NULL)
2743 clear_bit(i, &p->inuse);
2744 p = p->ptr[i];
2745 }
2746 i = nr & CARDMAP_MASK;
2747 p->ptr[i] = ptr;
2748 if (ptr != NULL)
2749 set_bit(i, &p->inuse);
2750 else
2751 clear_bit(i, &p->inuse);
2752 return 0;
2753 enomem:
2754 return -ENOMEM;
2755 }
2756
2757 static unsigned int cardmap_find_first_free(struct cardmap *map)
2758 {
2759 struct cardmap *p;
2760 unsigned int nr = 0;
2761 int i;
2762
2763 if ((p = map) == NULL)
2764 return 0;
2765 for (;;) {
2766 i = find_first_zero_bit(&p->inuse, CARDMAP_WIDTH);
2767 if (i >= CARDMAP_WIDTH) {
2768 if (p->parent == NULL)
2769 return CARDMAP_WIDTH << p->shift;
2770 p = p->parent;
2771 i = (nr >> p->shift) & CARDMAP_MASK;
2772 set_bit(i, &p->inuse);
2773 continue;
2774 }
2775 nr = (nr & (~CARDMAP_MASK << p->shift)) | (i << p->shift);
2776 if (p->shift == 0 || p->ptr[i] == NULL)
2777 return nr;
2778 p = p->ptr[i];
2779 }
2780 }
2781
2782 static void cardmap_destroy(struct cardmap **pmap)
2783 {
2784 struct cardmap *p, *np;
2785 int i;
2786
2787 for (p = *pmap; p != NULL; p = np) {
2788 if (p->shift != 0) {
2789 for (i = 0; i < CARDMAP_WIDTH; ++i)
2790 if (p->ptr[i] != NULL)
2791 break;
2792 if (i < CARDMAP_WIDTH) {
2793 np = p->ptr[i];
2794 p->ptr[i] = NULL;
2795 continue;
2796 }
2797 }
2798 np = p->parent;
2799 kfree(p);
2800 }
2801 *pmap = NULL;
2802 }
2803
2804 /* Module/initialization stuff */
2805
2806 module_init(ppp_init);
2807 module_exit(ppp_cleanup);
2808
2809 EXPORT_SYMBOL(ppp_register_channel);
2810 EXPORT_SYMBOL(ppp_unregister_channel);
2811 EXPORT_SYMBOL(ppp_channel_index);
2812 EXPORT_SYMBOL(ppp_unit_number);
2813 EXPORT_SYMBOL(ppp_input);
2814 EXPORT_SYMBOL(ppp_input_error);
2815 EXPORT_SYMBOL(ppp_output_wakeup);
2816 EXPORT_SYMBOL(ppp_register_compressor);
2817 EXPORT_SYMBOL(ppp_unregister_compressor);
2818 MODULE_LICENSE("GPL");
2819 MODULE_ALIAS_CHARDEV_MAJOR(PPP_MAJOR);
2820 MODULE_ALIAS("/dev/ppp");
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree