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pcmcia: CompactFlash driver for PA Semi Electra boards
[pv_ops_mirror.git] / drivers / net / ppp_generic.c
blob4b49d0e8c7ebcf911a7ebe55fb53529e32692782
1 /*
2 * Generic PPP layer for Linux.
3 *
4 * Copyright 1999-2002 Paul Mackerras.
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 *
11 * The generic PPP layer handles the PPP network interfaces, the
12 * /dev/ppp device, packet and VJ compression, and multilink.
13 * It talks to PPP `channels' via the interface defined in
14 * include/linux/ppp_channel.h. Channels provide the basic means for
15 * sending and receiving PPP frames on some kind of communications
16 * channel.
17 *
18 * Part of the code in this driver was inspired by the old async-only
19 * PPP driver, written by Michael Callahan and Al Longyear, and
20 * subsequently hacked by Paul Mackerras.
21 *
22 * ==FILEVERSION 20041108==
23 */
24
25 #include <linux/module.h>
26 #include <linux/kernel.h>
27 #include <linux/kmod.h>
28 #include <linux/init.h>
29 #include <linux/list.h>
30 #include <linux/netdevice.h>
31 #include <linux/poll.h>
32 #include <linux/ppp_defs.h>
33 #include <linux/filter.h>
34 #include <linux/if_ppp.h>
35 #include <linux/ppp_channel.h>
36 #include <linux/ppp-comp.h>
37 #include <linux/skbuff.h>
38 #include <linux/rtnetlink.h>
39 #include <linux/if_arp.h>
40 #include <linux/ip.h>
41 #include <linux/tcp.h>
42 #include <linux/spinlock.h>
43 #include <linux/rwsem.h>
44 #include <linux/stddef.h>
45 #include <linux/device.h>
46 #include <linux/mutex.h>
47 #include <net/slhc_vj.h>
48 #include <asm/atomic.h>
49
50 #define PPP_VERSION "2.4.2"
51
52 /*
53 * Network protocols we support.
54 */
55 #define NP_IP 0 /* Internet Protocol V4 */
56 #define NP_IPV6 1 /* Internet Protocol V6 */
57 #define NP_IPX 2 /* IPX protocol */
58 #define NP_AT 3 /* Appletalk protocol */
59 #define NP_MPLS_UC 4 /* MPLS unicast */
60 #define NP_MPLS_MC 5 /* MPLS multicast */
61 #define NUM_NP 6 /* Number of NPs. */
62
63 #define MPHDRLEN 6 /* multilink protocol header length */
64 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */
65 #define MIN_FRAG_SIZE 64
66
67 /*
68 * An instance of /dev/ppp can be associated with either a ppp
69 * interface unit or a ppp channel. In both cases, file->private_data
70 * points to one of these.
71 */
72 struct ppp_file {
73 enum {
74 INTERFACE=1, CHANNEL
75 } kind;
76 struct sk_buff_head xq; /* pppd transmit queue */
77 struct sk_buff_head rq; /* receive queue for pppd */
78 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */
79 atomic_t refcnt; /* # refs (incl /dev/ppp attached) */
80 int hdrlen; /* space to leave for headers */
81 int index; /* interface unit / channel number */
82 int dead; /* unit/channel has been shut down */
83 };
84
85 #define PF_TO_X(pf, X) container_of(pf, X, file)
86
87 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
88 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
89
90 /*
91 * Data structure describing one ppp unit.
92 * A ppp unit corresponds to a ppp network interface device
93 * and represents a multilink bundle.
94 * It can have 0 or more ppp channels connected to it.
95 */
96 struct ppp {
97 struct ppp_file file; /* stuff for read/write/poll 0 */
98 struct file *owner; /* file that owns this unit 48 */
99 struct list_head channels; /* list of attached channels 4c */
100 int n_channels; /* how many channels are attached 54 */
101 spinlock_t rlock; /* lock for receive side 58 */
102 spinlock_t wlock; /* lock for transmit side 5c */
103 int mru; /* max receive unit 60 */
104 unsigned int flags; /* control bits 64 */
105 unsigned int xstate; /* transmit state bits 68 */
106 unsigned int rstate; /* receive state bits 6c */
107 int debug; /* debug flags 70 */
108 struct slcompress *vj; /* state for VJ header compression */
109 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
110 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
111 struct compressor *xcomp; /* transmit packet compressor 8c */
112 void *xc_state; /* its internal state 90 */
113 struct compressor *rcomp; /* receive decompressor 94 */
114 void *rc_state; /* its internal state 98 */
115 unsigned long last_xmit; /* jiffies when last pkt sent 9c */
116 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
117 struct net_device *dev; /* network interface device a4 */
118 #ifdef CONFIG_PPP_MULTILINK
119 int nxchan; /* next channel to send something on */
120 u32 nxseq; /* next sequence number to send */
121 int mrru; /* MP: max reconst. receive unit */
122 u32 nextseq; /* MP: seq no of next packet */
123 u32 minseq; /* MP: min of most recent seqnos */
124 struct sk_buff_head mrq; /* MP: receive reconstruction queue */
125 #endif /* CONFIG_PPP_MULTILINK */
126 struct net_device_stats stats; /* statistics */
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 /*
358 * This could (should?) be enforced by the permissions on /dev/ppp.
359 */
360 if (!capable(CAP_NET_ADMIN))
361 return -EPERM;
362 return 0;
363 }
364
365 static int ppp_release(struct inode *inode, struct file *file)
366 {
367 struct ppp_file *pf = file->private_data;
368 struct ppp *ppp;
369
370 if (pf != 0) {
371 file->private_data = NULL;
372 if (pf->kind == INTERFACE) {
373 ppp = PF_TO_PPP(pf);
374 if (file == ppp->owner)
375 ppp_shutdown_interface(ppp);
376 }
377 if (atomic_dec_and_test(&pf->refcnt)) {
378 switch (pf->kind) {
379 case INTERFACE:
380 ppp_destroy_interface(PF_TO_PPP(pf));
381 break;
382 case CHANNEL:
383 ppp_destroy_channel(PF_TO_CHANNEL(pf));
384 break;
385 }
386 }
387 }
388 return 0;
389 }
390
391 static ssize_t ppp_read(struct file *file, char __user *buf,
392 size_t count, loff_t *ppos)
393 {
394 struct ppp_file *pf = file->private_data;
395 DECLARE_WAITQUEUE(wait, current);
396 ssize_t ret;
397 struct sk_buff *skb = NULL;
398
399 ret = count;
400
401 if (pf == 0)
402 return -ENXIO;
403 add_wait_queue(&pf->rwait, &wait);
404 for (;;) {
405 set_current_state(TASK_INTERRUPTIBLE);
406 skb = skb_dequeue(&pf->rq);
407 if (skb)
408 break;
409 ret = 0;
410 if (pf->dead)
411 break;
412 if (pf->kind == INTERFACE) {
413 /*
414 * Return 0 (EOF) on an interface that has no
415 * channels connected, unless it is looping
416 * network traffic (demand mode).
417 */
418 struct ppp *ppp = PF_TO_PPP(pf);
419 if (ppp->n_channels == 0
420 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
421 break;
422 }
423 ret = -EAGAIN;
424 if (file->f_flags & O_NONBLOCK)
425 break;
426 ret = -ERESTARTSYS;
427 if (signal_pending(current))
428 break;
429 schedule();
430 }
431 set_current_state(TASK_RUNNING);
432 remove_wait_queue(&pf->rwait, &wait);
433
434 if (skb == 0)
435 goto out;
436
437 ret = -EOVERFLOW;
438 if (skb->len > count)
439 goto outf;
440 ret = -EFAULT;
441 if (copy_to_user(buf, skb->data, skb->len))
442 goto outf;
443 ret = skb->len;
444
445 outf:
446 kfree_skb(skb);
447 out:
448 return ret;
449 }
450
451 static ssize_t ppp_write(struct file *file, const char __user *buf,
452 size_t count, loff_t *ppos)
453 {
454 struct ppp_file *pf = file->private_data;
455 struct sk_buff *skb;
456 ssize_t ret;
457
458 if (pf == 0)
459 return -ENXIO;
460 ret = -ENOMEM;
461 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
462 if (skb == 0)
463 goto out;
464 skb_reserve(skb, pf->hdrlen);
465 ret = -EFAULT;
466 if (copy_from_user(skb_put(skb, count), buf, count)) {
467 kfree_skb(skb);
468 goto out;
469 }
470
471 skb_queue_tail(&pf->xq, skb);
472
473 switch (pf->kind) {
474 case INTERFACE:
475 ppp_xmit_process(PF_TO_PPP(pf));
476 break;
477 case CHANNEL:
478 ppp_channel_push(PF_TO_CHANNEL(pf));
479 break;
480 }
481
482 ret = count;
483
484 out:
485 return ret;
486 }
487
488 /* No kernel lock - fine */
489 static unsigned int ppp_poll(struct file *file, poll_table *wait)
490 {
491 struct ppp_file *pf = file->private_data;
492 unsigned int mask;
493
494 if (pf == 0)
495 return 0;
496 poll_wait(file, &pf->rwait, wait);
497 mask = POLLOUT | POLLWRNORM;
498 if (skb_peek(&pf->rq) != 0)
499 mask |= POLLIN | POLLRDNORM;
500 if (pf->dead)
501 mask |= POLLHUP;
502 else if (pf->kind == INTERFACE) {
503 /* see comment in ppp_read */
504 struct ppp *ppp = PF_TO_PPP(pf);
505 if (ppp->n_channels == 0
506 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
507 mask |= POLLIN | POLLRDNORM;
508 }
509
510 return mask;
511 }
512
513 #ifdef CONFIG_PPP_FILTER
514 static int get_filter(void __user *arg, struct sock_filter **p)
515 {
516 struct sock_fprog uprog;
517 struct sock_filter *code = NULL;
518 int len, err;
519
520 if (copy_from_user(&uprog, arg, sizeof(uprog)))
521 return -EFAULT;
522
523 if (!uprog.len) {
524 *p = NULL;
525 return 0;
526 }
527
528 len = uprog.len * sizeof(struct sock_filter);
529 code = kmalloc(len, GFP_KERNEL);
530 if (code == NULL)
531 return -ENOMEM;
532
533 if (copy_from_user(code, uprog.filter, len)) {
534 kfree(code);
535 return -EFAULT;
536 }
537
538 err = sk_chk_filter(code, uprog.len);
539 if (err) {
540 kfree(code);
541 return err;
542 }
543
544 *p = code;
545 return uprog.len;
546 }
547 #endif /* CONFIG_PPP_FILTER */
548
549 static int ppp_ioctl(struct inode *inode, struct file *file,
550 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 == 0)
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 if (pf->kind == INTERFACE) {
579 ppp = PF_TO_PPP(pf);
580 if (file == ppp->owner)
581 ppp_shutdown_interface(ppp);
582 }
583 if (atomic_read(&file->f_count) <= 2) {
584 ppp_release(inode, file);
585 err = 0;
586 } else
587 printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%d\n",
588 atomic_read(&file->f_count));
589 return err;
590 }
591
592 if (pf->kind == CHANNEL) {
593 struct channel *pch = PF_TO_CHANNEL(pf);
594 struct ppp_channel *chan;
595
596 switch (cmd) {
597 case PPPIOCCONNECT:
598 if (get_user(unit, p))
599 break;
600 err = ppp_connect_channel(pch, unit);
601 break;
602
603 case PPPIOCDISCONN:
604 err = ppp_disconnect_channel(pch);
605 break;
606
607 default:
608 down_read(&pch->chan_sem);
609 chan = pch->chan;
610 err = -ENOTTY;
611 if (chan && chan->ops->ioctl)
612 err = chan->ops->ioctl(chan, cmd, arg);
613 up_read(&pch->chan_sem);
614 }
615 return err;
616 }
617
618 if (pf->kind != INTERFACE) {
619 /* can't happen */
620 printk(KERN_ERR "PPP: not interface or channel??\n");
621 return -EINVAL;
622 }
623
624 ppp = PF_TO_PPP(pf);
625 switch (cmd) {
626 case PPPIOCSMRU:
627 if (get_user(val, p))
628 break;
629 ppp->mru = val;
630 err = 0;
631 break;
632
633 case PPPIOCSFLAGS:
634 if (get_user(val, p))
635 break;
636 ppp_lock(ppp);
637 cflags = ppp->flags & ~val;
638 ppp->flags = val & SC_FLAG_BITS;
639 ppp_unlock(ppp);
640 if (cflags & SC_CCP_OPEN)
641 ppp_ccp_closed(ppp);
642 err = 0;
643 break;
644
645 case PPPIOCGFLAGS:
646 val = ppp->flags | ppp->xstate | ppp->rstate;
647 if (put_user(val, p))
648 break;
649 err = 0;
650 break;
651
652 case PPPIOCSCOMPRESS:
653 err = ppp_set_compress(ppp, arg);
654 break;
655
656 case PPPIOCGUNIT:
657 if (put_user(ppp->file.index, p))
658 break;
659 err = 0;
660 break;
661
662 case PPPIOCSDEBUG:
663 if (get_user(val, p))
664 break;
665 ppp->debug = val;
666 err = 0;
667 break;
668
669 case PPPIOCGDEBUG:
670 if (put_user(ppp->debug, p))
671 break;
672 err = 0;
673 break;
674
675 case PPPIOCGIDLE:
676 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
677 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
678 if (copy_to_user(argp, &idle, sizeof(idle)))
679 break;
680 err = 0;
681 break;
682
683 case PPPIOCSMAXCID:
684 if (get_user(val, p))
685 break;
686 val2 = 15;
687 if ((val >> 16) != 0) {
688 val2 = val >> 16;
689 val &= 0xffff;
690 }
691 vj = slhc_init(val2+1, val+1);
692 if (vj == 0) {
693 printk(KERN_ERR "PPP: no memory (VJ compressor)\n");
694 err = -ENOMEM;
695 break;
696 }
697 ppp_lock(ppp);
698 if (ppp->vj != 0)
699 slhc_free(ppp->vj);
700 ppp->vj = vj;
701 ppp_unlock(ppp);
702 err = 0;
703 break;
704
705 case PPPIOCGNPMODE:
706 case PPPIOCSNPMODE:
707 if (copy_from_user(&npi, argp, sizeof(npi)))
708 break;
709 err = proto_to_npindex(npi.protocol);
710 if (err < 0)
711 break;
712 i = err;
713 if (cmd == PPPIOCGNPMODE) {
714 err = -EFAULT;
715 npi.mode = ppp->npmode[i];
716 if (copy_to_user(argp, &npi, sizeof(npi)))
717 break;
718 } else {
719 ppp->npmode[i] = npi.mode;
720 /* we may be able to transmit more packets now (??) */
721 netif_wake_queue(ppp->dev);
722 }
723 err = 0;
724 break;
725
726 #ifdef CONFIG_PPP_FILTER
727 case PPPIOCSPASS:
728 {
729 struct sock_filter *code;
730 err = get_filter(argp, &code);
731 if (err >= 0) {
732 ppp_lock(ppp);
733 kfree(ppp->pass_filter);
734 ppp->pass_filter = code;
735 ppp->pass_len = err;
736 ppp_unlock(ppp);
737 err = 0;
738 }
739 break;
740 }
741 case PPPIOCSACTIVE:
742 {
743 struct sock_filter *code;
744 err = get_filter(argp, &code);
745 if (err >= 0) {
746 ppp_lock(ppp);
747 kfree(ppp->active_filter);
748 ppp->active_filter = code;
749 ppp->active_len = err;
750 ppp_unlock(ppp);
751 err = 0;
752 }
753 break;
754 }
755 #endif /* CONFIG_PPP_FILTER */
756
757 #ifdef CONFIG_PPP_MULTILINK
758 case PPPIOCSMRRU:
759 if (get_user(val, p))
760 break;
761 ppp_recv_lock(ppp);
762 ppp->mrru = val;
763 ppp_recv_unlock(ppp);
764 err = 0;
765 break;
766 #endif /* CONFIG_PPP_MULTILINK */
767
768 default:
769 err = -ENOTTY;
770 }
771
772 return err;
773 }
774
775 static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file,
776 unsigned int cmd, unsigned long arg)
777 {
778 int unit, err = -EFAULT;
779 struct ppp *ppp;
780 struct channel *chan;
781 int __user *p = (int __user *)arg;
782
783 switch (cmd) {
784 case PPPIOCNEWUNIT:
785 /* Create a new ppp unit */
786 if (get_user(unit, p))
787 break;
788 ppp = ppp_create_interface(unit, &err);
789 if (ppp == 0)
790 break;
791 file->private_data = &ppp->file;
792 ppp->owner = file;
793 err = -EFAULT;
794 if (put_user(ppp->file.index, p))
795 break;
796 err = 0;
797 break;
798
799 case PPPIOCATTACH:
800 /* Attach to an existing ppp unit */
801 if (get_user(unit, p))
802 break;
803 mutex_lock(&all_ppp_mutex);
804 err = -ENXIO;
805 ppp = ppp_find_unit(unit);
806 if (ppp != 0) {
807 atomic_inc(&ppp->file.refcnt);
808 file->private_data = &ppp->file;
809 err = 0;
810 }
811 mutex_unlock(&all_ppp_mutex);
812 break;
813
814 case PPPIOCATTCHAN:
815 if (get_user(unit, p))
816 break;
817 spin_lock_bh(&all_channels_lock);
818 err = -ENXIO;
819 chan = ppp_find_channel(unit);
820 if (chan != 0) {
821 atomic_inc(&chan->file.refcnt);
822 file->private_data = &chan->file;
823 err = 0;
824 }
825 spin_unlock_bh(&all_channels_lock);
826 break;
827
828 default:
829 err = -ENOTTY;
830 }
831 return err;
832 }
833
834 static const struct file_operations ppp_device_fops = {
835 .owner = THIS_MODULE,
836 .read = ppp_read,
837 .write = ppp_write,
838 .poll = ppp_poll,
839 .ioctl = ppp_ioctl,
840 .open = ppp_open,
841 .release = ppp_release
842 };
843
844 #define PPP_MAJOR 108
845
846 /* Called at boot time if ppp is compiled into the kernel,
847 or at module load time (from init_module) if compiled as a module. */
848 static int __init ppp_init(void)
849 {
850 int err;
851
852 printk(KERN_INFO "PPP generic driver version " PPP_VERSION "\n");
853 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
854 if (!err) {
855 ppp_class = class_create(THIS_MODULE, "ppp");
856 if (IS_ERR(ppp_class)) {
857 err = PTR_ERR(ppp_class);
858 goto out_chrdev;
859 }
860 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), "ppp");
861 }
862
863 out:
864 if (err)
865 printk(KERN_ERR "failed to register PPP device (%d)\n", err);
866 return err;
867
868 out_chrdev:
869 unregister_chrdev(PPP_MAJOR, "ppp");
870 goto out;
871 }
872
873 /*
874 * Network interface unit routines.
875 */
876 static int
877 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
878 {
879 struct ppp *ppp = (struct ppp *) dev->priv;
880 int npi, proto;
881 unsigned char *pp;
882
883 npi = ethertype_to_npindex(ntohs(skb->protocol));
884 if (npi < 0)
885 goto outf;
886
887 /* Drop, accept or reject the packet */
888 switch (ppp->npmode[npi]) {
889 case NPMODE_PASS:
890 break;
891 case NPMODE_QUEUE:
892 /* it would be nice to have a way to tell the network
893 system to queue this one up for later. */
894 goto outf;
895 case NPMODE_DROP:
896 case NPMODE_ERROR:
897 goto outf;
898 }
899
900 /* Put the 2-byte PPP protocol number on the front,
901 making sure there is room for the address and control fields. */
902 if (skb_cow_head(skb, PPP_HDRLEN))
903 goto outf;
904
905 pp = skb_push(skb, 2);
906 proto = npindex_to_proto[npi];
907 pp[0] = proto >> 8;
908 pp[1] = proto;
909
910 netif_stop_queue(dev);
911 skb_queue_tail(&ppp->file.xq, skb);
912 ppp_xmit_process(ppp);
913 return 0;
914
915 outf:
916 kfree_skb(skb);
917 ++ppp->stats.tx_dropped;
918 return 0;
919 }
920
921 static struct net_device_stats *
922 ppp_net_stats(struct net_device *dev)
923 {
924 struct ppp *ppp = (struct ppp *) dev->priv;
925
926 return &ppp->stats;
927 }
928
929 static int
930 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
931 {
932 struct ppp *ppp = dev->priv;
933 int err = -EFAULT;
934 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
935 struct ppp_stats stats;
936 struct ppp_comp_stats cstats;
937 char *vers;
938
939 switch (cmd) {
940 case SIOCGPPPSTATS:
941 ppp_get_stats(ppp, &stats);
942 if (copy_to_user(addr, &stats, sizeof(stats)))
943 break;
944 err = 0;
945 break;
946
947 case SIOCGPPPCSTATS:
948 memset(&cstats, 0, sizeof(cstats));
949 if (ppp->xc_state != 0)
950 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
951 if (ppp->rc_state != 0)
952 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
953 if (copy_to_user(addr, &cstats, sizeof(cstats)))
954 break;
955 err = 0;
956 break;
957
958 case SIOCGPPPVER:
959 vers = PPP_VERSION;
960 if (copy_to_user(addr, vers, strlen(vers) + 1))
961 break;
962 err = 0;
963 break;
964
965 default:
966 err = -EINVAL;
967 }
968
969 return err;
970 }
971
972 static void ppp_setup(struct net_device *dev)
973 {
974 dev->hard_header_len = PPP_HDRLEN;
975 dev->mtu = PPP_MTU;
976 dev->addr_len = 0;
977 dev->tx_queue_len = 3;
978 dev->type = ARPHRD_PPP;
979 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
980 }
981
982 /*
983 * Transmit-side routines.
984 */
985
986 /*
987 * Called to do any work queued up on the transmit side
988 * that can now be done.
989 */
990 static void
991 ppp_xmit_process(struct ppp *ppp)
992 {
993 struct sk_buff *skb;
994
995 ppp_xmit_lock(ppp);
996 if (ppp->dev != 0) {
997 ppp_push(ppp);
998 while (ppp->xmit_pending == 0
999 && (skb = skb_dequeue(&ppp->file.xq)) != 0)
1000 ppp_send_frame(ppp, skb);
1001 /* If there's no work left to do, tell the core net
1002 code that we can accept some more. */
1003 if (ppp->xmit_pending == 0 && skb_peek(&ppp->file.xq) == 0)
1004 netif_wake_queue(ppp->dev);
1005 }
1006 ppp_xmit_unlock(ppp);
1007 }
1008
1009 static inline struct sk_buff *
1010 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1011 {
1012 struct sk_buff *new_skb;
1013 int len;
1014 int new_skb_size = ppp->dev->mtu +
1015 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1016 int compressor_skb_size = ppp->dev->mtu +
1017 ppp->xcomp->comp_extra + PPP_HDRLEN;
1018 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1019 if (!new_skb) {
1020 if (net_ratelimit())
1021 printk(KERN_ERR "PPP: no memory (comp pkt)\n");
1022 return NULL;
1023 }
1024 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1025 skb_reserve(new_skb,
1026 ppp->dev->hard_header_len - PPP_HDRLEN);
1027
1028 /* compressor still expects A/C bytes in hdr */
1029 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1030 new_skb->data, skb->len + 2,
1031 compressor_skb_size);
1032 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1033 kfree_skb(skb);
1034 skb = new_skb;
1035 skb_put(skb, len);
1036 skb_pull(skb, 2); /* pull off A/C bytes */
1037 } else if (len == 0) {
1038 /* didn't compress, or CCP not up yet */
1039 kfree_skb(new_skb);
1040 new_skb = skb;
1041 } else {
1042 /*
1043 * (len < 0)
1044 * MPPE requires that we do not send unencrypted
1045 * frames. The compressor will return -1 if we
1046 * should drop the frame. We cannot simply test
1047 * the compress_proto because MPPE and MPPC share
1048 * the same number.
1049 */
1050 if (net_ratelimit())
1051 printk(KERN_ERR "ppp: compressor dropped pkt\n");
1052 kfree_skb(skb);
1053 kfree_skb(new_skb);
1054 new_skb = NULL;
1055 }
1056 return new_skb;
1057 }
1058
1059 /*
1060 * Compress and send a frame.
1061 * The caller should have locked the xmit path,
1062 * and xmit_pending should be 0.
1063 */
1064 static void
1065 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1066 {
1067 int proto = PPP_PROTO(skb);
1068 struct sk_buff *new_skb;
1069 int len;
1070 unsigned char *cp;
1071
1072 if (proto < 0x8000) {
1073 #ifdef CONFIG_PPP_FILTER
1074 /* check if we should pass this packet */
1075 /* the filter instructions are constructed assuming
1076 a four-byte PPP header on each packet */
1077 *skb_push(skb, 2) = 1;
1078 if (ppp->pass_filter
1079 && sk_run_filter(skb, ppp->pass_filter,
1080 ppp->pass_len) == 0) {
1081 if (ppp->debug & 1)
1082 printk(KERN_DEBUG "PPP: outbound frame not passed\n");
1083 kfree_skb(skb);
1084 return;
1085 }
1086 /* if this packet passes the active filter, record the time */
1087 if (!(ppp->active_filter
1088 && sk_run_filter(skb, ppp->active_filter,
1089 ppp->active_len) == 0))
1090 ppp->last_xmit = jiffies;
1091 skb_pull(skb, 2);
1092 #else
1093 /* for data packets, record the time */
1094 ppp->last_xmit = jiffies;
1095 #endif /* CONFIG_PPP_FILTER */
1096 }
1097
1098 ++ppp->stats.tx_packets;
1099 ppp->stats.tx_bytes += skb->len - 2;
1100
1101 switch (proto) {
1102 case PPP_IP:
1103 if (ppp->vj == 0 || (ppp->flags & SC_COMP_TCP) == 0)
1104 break;
1105 /* try to do VJ TCP header compression */
1106 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1107 GFP_ATOMIC);
1108 if (new_skb == 0) {
1109 printk(KERN_ERR "PPP: no memory (VJ comp pkt)\n");
1110 goto drop;
1111 }
1112 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1113 cp = skb->data + 2;
1114 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1115 new_skb->data + 2, &cp,
1116 !(ppp->flags & SC_NO_TCP_CCID));
1117 if (cp == skb->data + 2) {
1118 /* didn't compress */
1119 kfree_skb(new_skb);
1120 } else {
1121 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1122 proto = PPP_VJC_COMP;
1123 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1124 } else {
1125 proto = PPP_VJC_UNCOMP;
1126 cp[0] = skb->data[2];
1127 }
1128 kfree_skb(skb);
1129 skb = new_skb;
1130 cp = skb_put(skb, len + 2);
1131 cp[0] = 0;
1132 cp[1] = proto;
1133 }
1134 break;
1135
1136 case PPP_CCP:
1137 /* peek at outbound CCP frames */
1138 ppp_ccp_peek(ppp, skb, 0);
1139 break;
1140 }
1141
1142 /* try to do packet compression */
1143 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state != 0
1144 && proto != PPP_LCP && proto != PPP_CCP) {
1145 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1146 if (net_ratelimit())
1147 printk(KERN_ERR "ppp: compression required but down - pkt dropped.\n");
1148 goto drop;
1149 }
1150 skb = pad_compress_skb(ppp, skb);
1151 if (!skb)
1152 goto drop;
1153 }
1154
1155 /*
1156 * If we are waiting for traffic (demand dialling),
1157 * queue it up for pppd to receive.
1158 */
1159 if (ppp->flags & SC_LOOP_TRAFFIC) {
1160 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1161 goto drop;
1162 skb_queue_tail(&ppp->file.rq, skb);
1163 wake_up_interruptible(&ppp->file.rwait);
1164 return;
1165 }
1166
1167 ppp->xmit_pending = skb;
1168 ppp_push(ppp);
1169 return;
1170
1171 drop:
1172 if (skb)
1173 kfree_skb(skb);
1174 ++ppp->stats.tx_errors;
1175 }
1176
1177 /*
1178 * Try to send the frame in xmit_pending.
1179 * The caller should have the xmit path locked.
1180 */
1181 static void
1182 ppp_push(struct ppp *ppp)
1183 {
1184 struct list_head *list;
1185 struct channel *pch;
1186 struct sk_buff *skb = ppp->xmit_pending;
1187
1188 if (skb == 0)
1189 return;
1190
1191 list = &ppp->channels;
1192 if (list_empty(list)) {
1193 /* nowhere to send the packet, just drop it */
1194 ppp->xmit_pending = NULL;
1195 kfree_skb(skb);
1196 return;
1197 }
1198
1199 if ((ppp->flags & SC_MULTILINK) == 0) {
1200 /* not doing multilink: send it down the first channel */
1201 list = list->next;
1202 pch = list_entry(list, struct channel, clist);
1203
1204 spin_lock_bh(&pch->downl);
1205 if (pch->chan) {
1206 if (pch->chan->ops->start_xmit(pch->chan, skb))
1207 ppp->xmit_pending = NULL;
1208 } else {
1209 /* channel got unregistered */
1210 kfree_skb(skb);
1211 ppp->xmit_pending = NULL;
1212 }
1213 spin_unlock_bh(&pch->downl);
1214 return;
1215 }
1216
1217 #ifdef CONFIG_PPP_MULTILINK
1218 /* Multilink: fragment the packet over as many links
1219 as can take the packet at the moment. */
1220 if (!ppp_mp_explode(ppp, skb))
1221 return;
1222 #endif /* CONFIG_PPP_MULTILINK */
1223
1224 ppp->xmit_pending = NULL;
1225 kfree_skb(skb);
1226 }
1227
1228 #ifdef CONFIG_PPP_MULTILINK
1229 /*
1230 * Divide a packet to be transmitted into fragments and
1231 * send them out the individual links.
1232 */
1233 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1234 {
1235 int len, fragsize;
1236 int i, bits, hdrlen, mtu;
1237 int flen;
1238 int navail, nfree;
1239 int nbigger;
1240 unsigned char *p, *q;
1241 struct list_head *list;
1242 struct channel *pch;
1243 struct sk_buff *frag;
1244 struct ppp_channel *chan;
1245
1246 nfree = 0; /* # channels which have no packet already queued */
1247 navail = 0; /* total # of usable channels (not deregistered) */
1248 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1249 i = 0;
1250 list_for_each_entry(pch, &ppp->channels, clist) {
1251 navail += pch->avail = (pch->chan != NULL);
1252 if (pch->avail) {
1253 if (skb_queue_empty(&pch->file.xq) ||
1254 !pch->had_frag) {
1255 pch->avail = 2;
1256 ++nfree;
1257 }
1258 if (!pch->had_frag && i < ppp->nxchan)
1259 ppp->nxchan = i;
1260 }
1261 ++i;
1262 }
1263
1264 /*
1265 * Don't start sending this packet unless at least half of
1266 * the channels are free. This gives much better TCP
1267 * performance if we have a lot of channels.
1268 */
1269 if (nfree == 0 || nfree < navail / 2)
1270 return 0; /* can't take now, leave it in xmit_pending */
1271
1272 /* Do protocol field compression (XXX this should be optional) */
1273 p = skb->data;
1274 len = skb->len;
1275 if (*p == 0) {
1276 ++p;
1277 --len;
1278 }
1279
1280 /*
1281 * Decide on fragment size.
1282 * We create a fragment for each free channel regardless of
1283 * how small they are (i.e. even 0 length) in order to minimize
1284 * the time that it will take to detect when a channel drops
1285 * a fragment.
1286 */
1287 fragsize = len;
1288 if (nfree > 1)
1289 fragsize = DIV_ROUND_UP(fragsize, nfree);
1290 /* nbigger channels get fragsize bytes, the rest get fragsize-1,
1291 except if nbigger==0, then they all get fragsize. */
1292 nbigger = len % nfree;
1293
1294 /* skip to the channel after the one we last used
1295 and start at that one */
1296 list = &ppp->channels;
1297 for (i = 0; i < ppp->nxchan; ++i) {
1298 list = list->next;
1299 if (list == &ppp->channels) {
1300 i = 0;
1301 break;
1302 }
1303 }
1304
1305 /* create a fragment for each channel */
1306 bits = B;
1307 while (nfree > 0 || len > 0) {
1308 list = list->next;
1309 if (list == &ppp->channels) {
1310 i = 0;
1311 continue;
1312 }
1313 pch = list_entry(list, struct channel, clist);
1314 ++i;
1315 if (!pch->avail)
1316 continue;
1317
1318 /*
1319 * Skip this channel if it has a fragment pending already and
1320 * we haven't given a fragment to all of the free channels.
1321 */
1322 if (pch->avail == 1) {
1323 if (nfree > 0)
1324 continue;
1325 } else {
1326 --nfree;
1327 pch->avail = 1;
1328 }
1329
1330 /* check the channel's mtu and whether it is still attached. */
1331 spin_lock_bh(&pch->downl);
1332 if (pch->chan == NULL) {
1333 /* can't use this channel, it's being deregistered */
1334 spin_unlock_bh(&pch->downl);
1335 pch->avail = 0;
1336 if (--navail == 0)
1337 break;
1338 continue;
1339 }
1340
1341 /*
1342 * Create a fragment for this channel of
1343 * min(max(mtu+2-hdrlen, 4), fragsize, len) bytes.
1344 * If mtu+2-hdrlen < 4, that is a ridiculously small
1345 * MTU, so we use mtu = 2 + hdrlen.
1346 */
1347 if (fragsize > len)
1348 fragsize = len;
1349 flen = fragsize;
1350 mtu = pch->chan->mtu + 2 - hdrlen;
1351 if (mtu < 4)
1352 mtu = 4;
1353 if (flen > mtu)
1354 flen = mtu;
1355 if (flen == len && nfree == 0)
1356 bits |= E;
1357 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1358 if (frag == 0)
1359 goto noskb;
1360 q = skb_put(frag, flen + hdrlen);
1361
1362 /* make the MP header */
1363 q[0] = PPP_MP >> 8;
1364 q[1] = PPP_MP;
1365 if (ppp->flags & SC_MP_XSHORTSEQ) {
1366 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1367 q[3] = ppp->nxseq;
1368 } else {
1369 q[2] = bits;
1370 q[3] = ppp->nxseq >> 16;
1371 q[4] = ppp->nxseq >> 8;
1372 q[5] = ppp->nxseq;
1373 }
1374
1375 /*
1376 * Copy the data in.
1377 * Unfortunately there is a bug in older versions of
1378 * the Linux PPP multilink reconstruction code where it
1379 * drops 0-length fragments. Therefore we make sure the
1380 * fragment has at least one byte of data. Any bytes
1381 * we add in this situation will end up as padding on the
1382 * end of the reconstructed packet.
1383 */
1384 if (flen == 0)
1385 *skb_put(frag, 1) = 0;
1386 else
1387 memcpy(q + hdrlen, p, flen);
1388
1389 /* try to send it down the channel */
1390 chan = pch->chan;
1391 if (!skb_queue_empty(&pch->file.xq) ||
1392 !chan->ops->start_xmit(chan, frag))
1393 skb_queue_tail(&pch->file.xq, frag);
1394 pch->had_frag = 1;
1395 p += flen;
1396 len -= flen;
1397 ++ppp->nxseq;
1398 bits = 0;
1399 spin_unlock_bh(&pch->downl);
1400
1401 if (--nbigger == 0 && fragsize > 0)
1402 --fragsize;
1403 }
1404 ppp->nxchan = i;
1405
1406 return 1;
1407
1408 noskb:
1409 spin_unlock_bh(&pch->downl);
1410 if (ppp->debug & 1)
1411 printk(KERN_ERR "PPP: no memory (fragment)\n");
1412 ++ppp->stats.tx_errors;
1413 ++ppp->nxseq;
1414 return 1; /* abandon the frame */
1415 }
1416 #endif /* CONFIG_PPP_MULTILINK */
1417
1418 /*
1419 * Try to send data out on a channel.
1420 */
1421 static void
1422 ppp_channel_push(struct channel *pch)
1423 {
1424 struct sk_buff *skb;
1425 struct ppp *ppp;
1426
1427 spin_lock_bh(&pch->downl);
1428 if (pch->chan != 0) {
1429 while (!skb_queue_empty(&pch->file.xq)) {
1430 skb = skb_dequeue(&pch->file.xq);
1431 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1432 /* put the packet back and try again later */
1433 skb_queue_head(&pch->file.xq, skb);
1434 break;
1435 }
1436 }
1437 } else {
1438 /* channel got deregistered */
1439 skb_queue_purge(&pch->file.xq);
1440 }
1441 spin_unlock_bh(&pch->downl);
1442 /* see if there is anything from the attached unit to be sent */
1443 if (skb_queue_empty(&pch->file.xq)) {
1444 read_lock_bh(&pch->upl);
1445 ppp = pch->ppp;
1446 if (ppp != 0)
1447 ppp_xmit_process(ppp);
1448 read_unlock_bh(&pch->upl);
1449 }
1450 }
1451
1452 /*
1453 * Receive-side routines.
1454 */
1455
1456 /* misuse a few fields of the skb for MP reconstruction */
1457 #define sequence priority
1458 #define BEbits cb[0]
1459
1460 static inline void
1461 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1462 {
1463 ppp_recv_lock(ppp);
1464 /* ppp->dev == 0 means interface is closing down */
1465 if (ppp->dev != 0)
1466 ppp_receive_frame(ppp, skb, pch);
1467 else
1468 kfree_skb(skb);
1469 ppp_recv_unlock(ppp);
1470 }
1471
1472 void
1473 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1474 {
1475 struct channel *pch = chan->ppp;
1476 int proto;
1477
1478 if (pch == 0 || skb->len == 0) {
1479 kfree_skb(skb);
1480 return;
1481 }
1482
1483 proto = PPP_PROTO(skb);
1484 read_lock_bh(&pch->upl);
1485 if (pch->ppp == 0 || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1486 /* put it on the channel queue */
1487 skb_queue_tail(&pch->file.rq, skb);
1488 /* drop old frames if queue too long */
1489 while (pch->file.rq.qlen > PPP_MAX_RQLEN
1490 && (skb = skb_dequeue(&pch->file.rq)) != 0)
1491 kfree_skb(skb);
1492 wake_up_interruptible(&pch->file.rwait);
1493 } else {
1494 ppp_do_recv(pch->ppp, skb, pch);
1495 }
1496 read_unlock_bh(&pch->upl);
1497 }
1498
1499 /* Put a 0-length skb in the receive queue as an error indication */
1500 void
1501 ppp_input_error(struct ppp_channel *chan, int code)
1502 {
1503 struct channel *pch = chan->ppp;
1504 struct sk_buff *skb;
1505
1506 if (pch == 0)
1507 return;
1508
1509 read_lock_bh(&pch->upl);
1510 if (pch->ppp != 0) {
1511 skb = alloc_skb(0, GFP_ATOMIC);
1512 if (skb != 0) {
1513 skb->len = 0; /* probably unnecessary */
1514 skb->cb[0] = code;
1515 ppp_do_recv(pch->ppp, skb, pch);
1516 }
1517 }
1518 read_unlock_bh(&pch->upl);
1519 }
1520
1521 /*
1522 * We come in here to process a received frame.
1523 * The receive side of the ppp unit is locked.
1524 */
1525 static void
1526 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1527 {
1528 if (pskb_may_pull(skb, 2)) {
1529 #ifdef CONFIG_PPP_MULTILINK
1530 /* XXX do channel-level decompression here */
1531 if (PPP_PROTO(skb) == PPP_MP)
1532 ppp_receive_mp_frame(ppp, skb, pch);
1533 else
1534 #endif /* CONFIG_PPP_MULTILINK */
1535 ppp_receive_nonmp_frame(ppp, skb);
1536 return;
1537 }
1538
1539 if (skb->len > 0)
1540 /* note: a 0-length skb is used as an error indication */
1541 ++ppp->stats.rx_length_errors;
1542
1543 kfree_skb(skb);
1544 ppp_receive_error(ppp);
1545 }
1546
1547 static void
1548 ppp_receive_error(struct ppp *ppp)
1549 {
1550 ++ppp->stats.rx_errors;
1551 if (ppp->vj != 0)
1552 slhc_toss(ppp->vj);
1553 }
1554
1555 static void
1556 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1557 {
1558 struct sk_buff *ns;
1559 int proto, len, npi;
1560
1561 /*
1562 * Decompress the frame, if compressed.
1563 * Note that some decompressors need to see uncompressed frames
1564 * that come in as well as compressed frames.
1565 */
1566 if (ppp->rc_state != 0 && (ppp->rstate & SC_DECOMP_RUN)
1567 && (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1568 skb = ppp_decompress_frame(ppp, skb);
1569
1570 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1571 goto err;
1572
1573 proto = PPP_PROTO(skb);
1574 switch (proto) {
1575 case PPP_VJC_COMP:
1576 /* decompress VJ compressed packets */
1577 if (ppp->vj == 0 || (ppp->flags & SC_REJ_COMP_TCP))
1578 goto err;
1579
1580 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1581 /* copy to a new sk_buff with more tailroom */
1582 ns = dev_alloc_skb(skb->len + 128);
1583 if (ns == 0) {
1584 printk(KERN_ERR"PPP: no memory (VJ decomp)\n");
1585 goto err;
1586 }
1587 skb_reserve(ns, 2);
1588 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1589 kfree_skb(skb);
1590 skb = ns;
1591 }
1592 else
1593 skb->ip_summed = CHECKSUM_NONE;
1594
1595 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1596 if (len <= 0) {
1597 printk(KERN_DEBUG "PPP: VJ decompression error\n");
1598 goto err;
1599 }
1600 len += 2;
1601 if (len > skb->len)
1602 skb_put(skb, len - skb->len);
1603 else if (len < skb->len)
1604 skb_trim(skb, len);
1605 proto = PPP_IP;
1606 break;
1607
1608 case PPP_VJC_UNCOMP:
1609 if (ppp->vj == 0 || (ppp->flags & SC_REJ_COMP_TCP))
1610 goto err;
1611
1612 /* Until we fix the decompressor need to make sure
1613 * data portion is linear.
1614 */
1615 if (!pskb_may_pull(skb, skb->len))
1616 goto err;
1617
1618 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1619 printk(KERN_ERR "PPP: VJ uncompressed error\n");
1620 goto err;
1621 }
1622 proto = PPP_IP;
1623 break;
1624
1625 case PPP_CCP:
1626 ppp_ccp_peek(ppp, skb, 1);
1627 break;
1628 }
1629
1630 ++ppp->stats.rx_packets;
1631 ppp->stats.rx_bytes += skb->len - 2;
1632
1633 npi = proto_to_npindex(proto);
1634 if (npi < 0) {
1635 /* control or unknown frame - pass it to pppd */
1636 skb_queue_tail(&ppp->file.rq, skb);
1637 /* limit queue length by dropping old frames */
1638 while (ppp->file.rq.qlen > PPP_MAX_RQLEN
1639 && (skb = skb_dequeue(&ppp->file.rq)) != 0)
1640 kfree_skb(skb);
1641 /* wake up any process polling or blocking on read */
1642 wake_up_interruptible(&ppp->file.rwait);
1643
1644 } else {
1645 /* network protocol frame - give it to the kernel */
1646
1647 #ifdef CONFIG_PPP_FILTER
1648 /* check if the packet passes the pass and active filters */
1649 /* the filter instructions are constructed assuming
1650 a four-byte PPP header on each packet */
1651 if (ppp->pass_filter || ppp->active_filter) {
1652 if (skb_cloned(skb) &&
1653 pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
1654 goto err;
1655
1656 *skb_push(skb, 2) = 0;
1657 if (ppp->pass_filter
1658 && sk_run_filter(skb, ppp->pass_filter,
1659 ppp->pass_len) == 0) {
1660 if (ppp->debug & 1)
1661 printk(KERN_DEBUG "PPP: inbound frame "
1662 "not passed\n");
1663 kfree_skb(skb);
1664 return;
1665 }
1666 if (!(ppp->active_filter
1667 && sk_run_filter(skb, ppp->active_filter,
1668 ppp->active_len) == 0))
1669 ppp->last_recv = jiffies;
1670 __skb_pull(skb, 2);
1671 } else
1672 #endif /* CONFIG_PPP_FILTER */
1673 ppp->last_recv = jiffies;
1674
1675 if ((ppp->dev->flags & IFF_UP) == 0
1676 || ppp->npmode[npi] != NPMODE_PASS) {
1677 kfree_skb(skb);
1678 } else {
1679 /* chop off protocol */
1680 skb_pull_rcsum(skb, 2);
1681 skb->dev = ppp->dev;
1682 skb->protocol = htons(npindex_to_ethertype[npi]);
1683 skb_reset_mac_header(skb);
1684 netif_rx(skb);
1685 ppp->dev->last_rx = jiffies;
1686 }
1687 }
1688 return;
1689
1690 err:
1691 kfree_skb(skb);
1692 ppp_receive_error(ppp);
1693 }
1694
1695 static struct sk_buff *
1696 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1697 {
1698 int proto = PPP_PROTO(skb);
1699 struct sk_buff *ns;
1700 int len;
1701
1702 /* Until we fix all the decompressor's need to make sure
1703 * data portion is linear.
1704 */
1705 if (!pskb_may_pull(skb, skb->len))
1706 goto err;
1707
1708 if (proto == PPP_COMP) {
1709 int obuff_size;
1710
1711 switch(ppp->rcomp->compress_proto) {
1712 case CI_MPPE:
1713 obuff_size = ppp->mru + PPP_HDRLEN + 1;
1714 break;
1715 default:
1716 obuff_size = ppp->mru + PPP_HDRLEN;
1717 break;
1718 }
1719
1720 ns = dev_alloc_skb(obuff_size);
1721 if (ns == 0) {
1722 printk(KERN_ERR "ppp_decompress_frame: no memory\n");
1723 goto err;
1724 }
1725 /* the decompressor still expects the A/C bytes in the hdr */
1726 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1727 skb->len + 2, ns->data, obuff_size);
1728 if (len < 0) {
1729 /* Pass the compressed frame to pppd as an
1730 error indication. */
1731 if (len == DECOMP_FATALERROR)
1732 ppp->rstate |= SC_DC_FERROR;
1733 kfree_skb(ns);
1734 goto err;
1735 }
1736
1737 kfree_skb(skb);
1738 skb = ns;
1739 skb_put(skb, len);
1740 skb_pull(skb, 2); /* pull off the A/C bytes */
1741
1742 } else {
1743 /* Uncompressed frame - pass to decompressor so it
1744 can update its dictionary if necessary. */
1745 if (ppp->rcomp->incomp)
1746 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1747 skb->len + 2);
1748 }
1749
1750 return skb;
1751
1752 err:
1753 ppp->rstate |= SC_DC_ERROR;
1754 ppp_receive_error(ppp);
1755 return skb;
1756 }
1757
1758 #ifdef CONFIG_PPP_MULTILINK
1759 /*
1760 * Receive a multilink frame.
1761 * We put it on the reconstruction queue and then pull off
1762 * as many completed frames as we can.
1763 */
1764 static void
1765 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1766 {
1767 u32 mask, seq;
1768 struct channel *ch;
1769 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1770
1771 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
1772 goto err; /* no good, throw it away */
1773
1774 /* Decode sequence number and begin/end bits */
1775 if (ppp->flags & SC_MP_SHORTSEQ) {
1776 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1777 mask = 0xfff;
1778 } else {
1779 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1780 mask = 0xffffff;
1781 }
1782 skb->BEbits = skb->data[2];
1783 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
1784
1785 /*
1786 * Do protocol ID decompression on the first fragment of each packet.
1787 */
1788 if ((skb->BEbits & B) && (skb->data[0] & 1))
1789 *skb_push(skb, 1) = 0;
1790
1791 /*
1792 * Expand sequence number to 32 bits, making it as close
1793 * as possible to ppp->minseq.
1794 */
1795 seq |= ppp->minseq & ~mask;
1796 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
1797 seq += mask + 1;
1798 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
1799 seq -= mask + 1; /* should never happen */
1800 skb->sequence = seq;
1801 pch->lastseq = seq;
1802
1803 /*
1804 * If this packet comes before the next one we were expecting,
1805 * drop it.
1806 */
1807 if (seq_before(seq, ppp->nextseq)) {
1808 kfree_skb(skb);
1809 ++ppp->stats.rx_dropped;
1810 ppp_receive_error(ppp);
1811 return;
1812 }
1813
1814 /*
1815 * Reevaluate minseq, the minimum over all channels of the
1816 * last sequence number received on each channel. Because of
1817 * the increasing sequence number rule, we know that any fragment
1818 * before `minseq' which hasn't arrived is never going to arrive.
1819 * The list of channels can't change because we have the receive
1820 * side of the ppp unit locked.
1821 */
1822 list_for_each_entry(ch, &ppp->channels, clist) {
1823 if (seq_before(ch->lastseq, seq))
1824 seq = ch->lastseq;
1825 }
1826 if (seq_before(ppp->minseq, seq))
1827 ppp->minseq = seq;
1828
1829 /* Put the fragment on the reconstruction queue */
1830 ppp_mp_insert(ppp, skb);
1831
1832 /* If the queue is getting long, don't wait any longer for packets
1833 before the start of the queue. */
1834 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN
1835 && seq_before(ppp->minseq, ppp->mrq.next->sequence))
1836 ppp->minseq = ppp->mrq.next->sequence;
1837
1838 /* Pull completed packets off the queue and receive them. */
1839 while ((skb = ppp_mp_reconstruct(ppp)) != 0)
1840 ppp_receive_nonmp_frame(ppp, skb);
1841
1842 return;
1843
1844 err:
1845 kfree_skb(skb);
1846 ppp_receive_error(ppp);
1847 }
1848
1849 /*
1850 * Insert a fragment on the MP reconstruction queue.
1851 * The queue is ordered by increasing sequence number.
1852 */
1853 static void
1854 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
1855 {
1856 struct sk_buff *p;
1857 struct sk_buff_head *list = &ppp->mrq;
1858 u32 seq = skb->sequence;
1859
1860 /* N.B. we don't need to lock the list lock because we have the
1861 ppp unit receive-side lock. */
1862 for (p = list->next; p != (struct sk_buff *)list; p = p->next)
1863 if (seq_before(seq, p->sequence))
1864 break;
1865 __skb_insert(skb, p->prev, p, list);
1866 }
1867
1868 /*
1869 * Reconstruct a packet from the MP fragment queue.
1870 * We go through increasing sequence numbers until we find a
1871 * complete packet, or we get to the sequence number for a fragment
1872 * which hasn't arrived but might still do so.
1873 */
1874 struct sk_buff *
1875 ppp_mp_reconstruct(struct ppp *ppp)
1876 {
1877 u32 seq = ppp->nextseq;
1878 u32 minseq = ppp->minseq;
1879 struct sk_buff_head *list = &ppp->mrq;
1880 struct sk_buff *p, *next;
1881 struct sk_buff *head, *tail;
1882 struct sk_buff *skb = NULL;
1883 int lost = 0, len = 0;
1884
1885 if (ppp->mrru == 0) /* do nothing until mrru is set */
1886 return NULL;
1887 head = list->next;
1888 tail = NULL;
1889 for (p = head; p != (struct sk_buff *) list; p = next) {
1890 next = p->next;
1891 if (seq_before(p->sequence, seq)) {
1892 /* this can't happen, anyway ignore the skb */
1893 printk(KERN_ERR "ppp_mp_reconstruct bad seq %u < %u\n",
1894 p->sequence, seq);
1895 head = next;
1896 continue;
1897 }
1898 if (p->sequence != seq) {
1899 /* Fragment `seq' is missing. If it is after
1900 minseq, it might arrive later, so stop here. */
1901 if (seq_after(seq, minseq))
1902 break;
1903 /* Fragment `seq' is lost, keep going. */
1904 lost = 1;
1905 seq = seq_before(minseq, p->sequence)?
1906 minseq + 1: p->sequence;
1907 next = p;
1908 continue;
1909 }
1910
1911 /*
1912 * At this point we know that all the fragments from
1913 * ppp->nextseq to seq are either present or lost.
1914 * Also, there are no complete packets in the queue
1915 * that have no missing fragments and end before this
1916 * fragment.
1917 */
1918
1919 /* B bit set indicates this fragment starts a packet */
1920 if (p->BEbits & B) {
1921 head = p;
1922 lost = 0;
1923 len = 0;
1924 }
1925
1926 len += p->len;
1927
1928 /* Got a complete packet yet? */
1929 if (lost == 0 && (p->BEbits & E) && (head->BEbits & B)) {
1930 if (len > ppp->mrru + 2) {
1931 ++ppp->stats.rx_length_errors;
1932 printk(KERN_DEBUG "PPP: reconstructed packet"
1933 " is too long (%d)\n", len);
1934 } else if (p == head) {
1935 /* fragment is complete packet - reuse skb */
1936 tail = p;
1937 skb = skb_get(p);
1938 break;
1939 } else if ((skb = dev_alloc_skb(len)) == NULL) {
1940 ++ppp->stats.rx_missed_errors;
1941 printk(KERN_DEBUG "PPP: no memory for "
1942 "reconstructed packet");
1943 } else {
1944 tail = p;
1945 break;
1946 }
1947 ppp->nextseq = seq + 1;
1948 }
1949
1950 /*
1951 * If this is the ending fragment of a packet,
1952 * and we haven't found a complete valid packet yet,
1953 * we can discard up to and including this fragment.
1954 */
1955 if (p->BEbits & E)
1956 head = next;
1957
1958 ++seq;
1959 }
1960
1961 /* If we have a complete packet, copy it all into one skb. */
1962 if (tail != NULL) {
1963 /* If we have discarded any fragments,
1964 signal a receive error. */
1965 if (head->sequence != ppp->nextseq) {
1966 if (ppp->debug & 1)
1967 printk(KERN_DEBUG " missed pkts %u..%u\n",
1968 ppp->nextseq, head->sequence-1);
1969 ++ppp->stats.rx_dropped;
1970 ppp_receive_error(ppp);
1971 }
1972
1973 if (head != tail)
1974 /* copy to a single skb */
1975 for (p = head; p != tail->next; p = p->next)
1976 skb_copy_bits(p, 0, skb_put(skb, p->len), p->len);
1977 ppp->nextseq = tail->sequence + 1;
1978 head = tail->next;
1979 }
1980
1981 /* Discard all the skbuffs that we have copied the data out of
1982 or that we can't use. */
1983 while ((p = list->next) != head) {
1984 __skb_unlink(p, list);
1985 kfree_skb(p);
1986 }
1987
1988 return skb;
1989 }
1990 #endif /* CONFIG_PPP_MULTILINK */
1991
1992 /*
1993 * Channel interface.
1994 */
1995
1996 /*
1997 * Create a new, unattached ppp channel.
1998 */
1999 int
2000 ppp_register_channel(struct ppp_channel *chan)
2001 {
2002 struct channel *pch;
2003
2004 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2005 if (pch == 0)
2006 return -ENOMEM;
2007 pch->ppp = NULL;
2008 pch->chan = chan;
2009 chan->ppp = pch;
2010 init_ppp_file(&pch->file, CHANNEL);
2011 pch->file.hdrlen = chan->hdrlen;
2012 #ifdef CONFIG_PPP_MULTILINK
2013 pch->lastseq = -1;
2014 #endif /* CONFIG_PPP_MULTILINK */
2015 init_rwsem(&pch->chan_sem);
2016 spin_lock_init(&pch->downl);
2017 rwlock_init(&pch->upl);
2018 spin_lock_bh(&all_channels_lock);
2019 pch->file.index = ++last_channel_index;
2020 list_add(&pch->list, &new_channels);
2021 atomic_inc(&channel_count);
2022 spin_unlock_bh(&all_channels_lock);
2023 return 0;
2024 }
2025
2026 /*
2027 * Return the index of a channel.
2028 */
2029 int ppp_channel_index(struct ppp_channel *chan)
2030 {
2031 struct channel *pch = chan->ppp;
2032
2033 if (pch != 0)
2034 return pch->file.index;
2035 return -1;
2036 }
2037
2038 /*
2039 * Return the PPP unit number to which a channel is connected.
2040 */
2041 int ppp_unit_number(struct ppp_channel *chan)
2042 {
2043 struct channel *pch = chan->ppp;
2044 int unit = -1;
2045
2046 if (pch != 0) {
2047 read_lock_bh(&pch->upl);
2048 if (pch->ppp != 0)
2049 unit = pch->ppp->file.index;
2050 read_unlock_bh(&pch->upl);
2051 }
2052 return unit;
2053 }
2054
2055 /*
2056 * Disconnect a channel from the generic layer.
2057 * This must be called in process context.
2058 */
2059 void
2060 ppp_unregister_channel(struct ppp_channel *chan)
2061 {
2062 struct channel *pch = chan->ppp;
2063
2064 if (pch == 0)
2065 return; /* should never happen */
2066 chan->ppp = NULL;
2067
2068 /*
2069 * This ensures that we have returned from any calls into the
2070 * the channel's start_xmit or ioctl routine before we proceed.
2071 */
2072 down_write(&pch->chan_sem);
2073 spin_lock_bh(&pch->downl);
2074 pch->chan = NULL;
2075 spin_unlock_bh(&pch->downl);
2076 up_write(&pch->chan_sem);
2077 ppp_disconnect_channel(pch);
2078 spin_lock_bh(&all_channels_lock);
2079 list_del(&pch->list);
2080 spin_unlock_bh(&all_channels_lock);
2081 pch->file.dead = 1;
2082 wake_up_interruptible(&pch->file.rwait);
2083 if (atomic_dec_and_test(&pch->file.refcnt))
2084 ppp_destroy_channel(pch);
2085 }
2086
2087 /*
2088 * Callback from a channel when it can accept more to transmit.
2089 * This should be called at BH/softirq level, not interrupt level.
2090 */
2091 void
2092 ppp_output_wakeup(struct ppp_channel *chan)
2093 {
2094 struct channel *pch = chan->ppp;
2095
2096 if (pch == 0)
2097 return;
2098 ppp_channel_push(pch);
2099 }
2100
2101 /*
2102 * Compression control.
2103 */
2104
2105 /* Process the PPPIOCSCOMPRESS ioctl. */
2106 static int
2107 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2108 {
2109 int err;
2110 struct compressor *cp, *ocomp;
2111 struct ppp_option_data data;
2112 void *state, *ostate;
2113 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2114
2115 err = -EFAULT;
2116 if (copy_from_user(&data, (void __user *) arg, sizeof(data))
2117 || (data.length <= CCP_MAX_OPTION_LENGTH
2118 && copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2119 goto out;
2120 err = -EINVAL;
2121 if (data.length > CCP_MAX_OPTION_LENGTH
2122 || ccp_option[1] < 2 || ccp_option[1] > data.length)
2123 goto out;
2124
2125 cp = find_compressor(ccp_option[0]);
2126 #ifdef CONFIG_KMOD
2127 if (cp == 0) {
2128 request_module("ppp-compress-%d", ccp_option[0]);
2129 cp = find_compressor(ccp_option[0]);
2130 }
2131 #endif /* CONFIG_KMOD */
2132 if (cp == 0)
2133 goto out;
2134
2135 err = -ENOBUFS;
2136 if (data.transmit) {
2137 state = cp->comp_alloc(ccp_option, data.length);
2138 if (state != 0) {
2139 ppp_xmit_lock(ppp);
2140 ppp->xstate &= ~SC_COMP_RUN;
2141 ocomp = ppp->xcomp;
2142 ostate = ppp->xc_state;
2143 ppp->xcomp = cp;
2144 ppp->xc_state = state;
2145 ppp_xmit_unlock(ppp);
2146 if (ostate != 0) {
2147 ocomp->comp_free(ostate);
2148 module_put(ocomp->owner);
2149 }
2150 err = 0;
2151 } else
2152 module_put(cp->owner);
2153
2154 } else {
2155 state = cp->decomp_alloc(ccp_option, data.length);
2156 if (state != 0) {
2157 ppp_recv_lock(ppp);
2158 ppp->rstate &= ~SC_DECOMP_RUN;
2159 ocomp = ppp->rcomp;
2160 ostate = ppp->rc_state;
2161 ppp->rcomp = cp;
2162 ppp->rc_state = state;
2163 ppp_recv_unlock(ppp);
2164 if (ostate != 0) {
2165 ocomp->decomp_free(ostate);
2166 module_put(ocomp->owner);
2167 }
2168 err = 0;
2169 } else
2170 module_put(cp->owner);
2171 }
2172
2173 out:
2174 return err;
2175 }
2176
2177 /*
2178 * Look at a CCP packet and update our state accordingly.
2179 * We assume the caller has the xmit or recv path locked.
2180 */
2181 static void
2182 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2183 {
2184 unsigned char *dp;
2185 int len;
2186
2187 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2188 return; /* no header */
2189 dp = skb->data + 2;
2190
2191 switch (CCP_CODE(dp)) {
2192 case CCP_CONFREQ:
2193
2194 /* A ConfReq starts negotiation of compression
2195 * in one direction of transmission,
2196 * and hence brings it down...but which way?
2197 *
2198 * Remember:
2199 * A ConfReq indicates what the sender would like to receive
2200 */
2201 if(inbound)
2202 /* He is proposing what I should send */
2203 ppp->xstate &= ~SC_COMP_RUN;
2204 else
2205 /* I am proposing to what he should send */
2206 ppp->rstate &= ~SC_DECOMP_RUN;
2207
2208 break;
2209
2210 case CCP_TERMREQ:
2211 case CCP_TERMACK:
2212 /*
2213 * CCP is going down, both directions of transmission
2214 */
2215 ppp->rstate &= ~SC_DECOMP_RUN;
2216 ppp->xstate &= ~SC_COMP_RUN;
2217 break;
2218
2219 case CCP_CONFACK:
2220 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2221 break;
2222 len = CCP_LENGTH(dp);
2223 if (!pskb_may_pull(skb, len + 2))
2224 return; /* too short */
2225 dp += CCP_HDRLEN;
2226 len -= CCP_HDRLEN;
2227 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2228 break;
2229 if (inbound) {
2230 /* we will start receiving compressed packets */
2231 if (ppp->rc_state == 0)
2232 break;
2233 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2234 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2235 ppp->rstate |= SC_DECOMP_RUN;
2236 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2237 }
2238 } else {
2239 /* we will soon start sending compressed packets */
2240 if (ppp->xc_state == 0)
2241 break;
2242 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2243 ppp->file.index, 0, ppp->debug))
2244 ppp->xstate |= SC_COMP_RUN;
2245 }
2246 break;
2247
2248 case CCP_RESETACK:
2249 /* reset the [de]compressor */
2250 if ((ppp->flags & SC_CCP_UP) == 0)
2251 break;
2252 if (inbound) {
2253 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2254 ppp->rcomp->decomp_reset(ppp->rc_state);
2255 ppp->rstate &= ~SC_DC_ERROR;
2256 }
2257 } else {
2258 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2259 ppp->xcomp->comp_reset(ppp->xc_state);
2260 }
2261 break;
2262 }
2263 }
2264
2265 /* Free up compression resources. */
2266 static void
2267 ppp_ccp_closed(struct ppp *ppp)
2268 {
2269 void *xstate, *rstate;
2270 struct compressor *xcomp, *rcomp;
2271
2272 ppp_lock(ppp);
2273 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2274 ppp->xstate = 0;
2275 xcomp = ppp->xcomp;
2276 xstate = ppp->xc_state;
2277 ppp->xc_state = NULL;
2278 ppp->rstate = 0;
2279 rcomp = ppp->rcomp;
2280 rstate = ppp->rc_state;
2281 ppp->rc_state = NULL;
2282 ppp_unlock(ppp);
2283
2284 if (xstate) {
2285 xcomp->comp_free(xstate);
2286 module_put(xcomp->owner);
2287 }
2288 if (rstate) {
2289 rcomp->decomp_free(rstate);
2290 module_put(rcomp->owner);
2291 }
2292 }
2293
2294 /* List of compressors. */
2295 static LIST_HEAD(compressor_list);
2296 static DEFINE_SPINLOCK(compressor_list_lock);
2297
2298 struct compressor_entry {
2299 struct list_head list;
2300 struct compressor *comp;
2301 };
2302
2303 static struct compressor_entry *
2304 find_comp_entry(int proto)
2305 {
2306 struct compressor_entry *ce;
2307
2308 list_for_each_entry(ce, &compressor_list, list) {
2309 if (ce->comp->compress_proto == proto)
2310 return ce;
2311 }
2312 return NULL;
2313 }
2314
2315 /* Register a compressor */
2316 int
2317 ppp_register_compressor(struct compressor *cp)
2318 {
2319 struct compressor_entry *ce;
2320 int ret;
2321 spin_lock(&compressor_list_lock);
2322 ret = -EEXIST;
2323 if (find_comp_entry(cp->compress_proto) != 0)
2324 goto out;
2325 ret = -ENOMEM;
2326 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2327 if (ce == 0)
2328 goto out;
2329 ret = 0;
2330 ce->comp = cp;
2331 list_add(&ce->list, &compressor_list);
2332 out:
2333 spin_unlock(&compressor_list_lock);
2334 return ret;
2335 }
2336
2337 /* Unregister a compressor */
2338 void
2339 ppp_unregister_compressor(struct compressor *cp)
2340 {
2341 struct compressor_entry *ce;
2342
2343 spin_lock(&compressor_list_lock);
2344 ce = find_comp_entry(cp->compress_proto);
2345 if (ce != 0 && ce->comp == cp) {
2346 list_del(&ce->list);
2347 kfree(ce);
2348 }
2349 spin_unlock(&compressor_list_lock);
2350 }
2351
2352 /* Find a compressor. */
2353 static struct compressor *
2354 find_compressor(int type)
2355 {
2356 struct compressor_entry *ce;
2357 struct compressor *cp = NULL;
2358
2359 spin_lock(&compressor_list_lock);
2360 ce = find_comp_entry(type);
2361 if (ce != 0) {
2362 cp = ce->comp;
2363 if (!try_module_get(cp->owner))
2364 cp = NULL;
2365 }
2366 spin_unlock(&compressor_list_lock);
2367 return cp;
2368 }
2369
2370 /*
2371 * Miscelleneous stuff.
2372 */
2373
2374 static void
2375 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2376 {
2377 struct slcompress *vj = ppp->vj;
2378
2379 memset(st, 0, sizeof(*st));
2380 st->p.ppp_ipackets = ppp->stats.rx_packets;
2381 st->p.ppp_ierrors = ppp->stats.rx_errors;
2382 st->p.ppp_ibytes = ppp->stats.rx_bytes;
2383 st->p.ppp_opackets = ppp->stats.tx_packets;
2384 st->p.ppp_oerrors = ppp->stats.tx_errors;
2385 st->p.ppp_obytes = ppp->stats.tx_bytes;
2386 if (vj == 0)
2387 return;
2388 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2389 st->vj.vjs_compressed = vj->sls_o_compressed;
2390 st->vj.vjs_searches = vj->sls_o_searches;
2391 st->vj.vjs_misses = vj->sls_o_misses;
2392 st->vj.vjs_errorin = vj->sls_i_error;
2393 st->vj.vjs_tossed = vj->sls_i_tossed;
2394 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2395 st->vj.vjs_compressedin = vj->sls_i_compressed;
2396 }
2397
2398 /*
2399 * Stuff for handling the lists of ppp units and channels
2400 * and for initialization.
2401 */
2402
2403 /*
2404 * Create a new ppp interface unit. Fails if it can't allocate memory
2405 * or if there is already a unit with the requested number.
2406 * unit == -1 means allocate a new number.
2407 */
2408 static struct ppp *
2409 ppp_create_interface(int unit, int *retp)
2410 {
2411 struct ppp *ppp;
2412 struct net_device *dev = NULL;
2413 int ret = -ENOMEM;
2414 int i;
2415
2416 ppp = kzalloc(sizeof(struct ppp), GFP_KERNEL);
2417 if (!ppp)
2418 goto out;
2419 dev = alloc_netdev(0, "", ppp_setup);
2420 if (!dev)
2421 goto out1;
2422
2423 ppp->mru = PPP_MRU;
2424 init_ppp_file(&ppp->file, INTERFACE);
2425 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2426 for (i = 0; i < NUM_NP; ++i)
2427 ppp->npmode[i] = NPMODE_PASS;
2428 INIT_LIST_HEAD(&ppp->channels);
2429 spin_lock_init(&ppp->rlock);
2430 spin_lock_init(&ppp->wlock);
2431 #ifdef CONFIG_PPP_MULTILINK
2432 ppp->minseq = -1;
2433 skb_queue_head_init(&ppp->mrq);
2434 #endif /* CONFIG_PPP_MULTILINK */
2435 ppp->dev = dev;
2436 dev->priv = ppp;
2437
2438 dev->hard_start_xmit = ppp_start_xmit;
2439 dev->get_stats = ppp_net_stats;
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 out2:
2472 mutex_unlock(&all_ppp_mutex);
2473 free_netdev(dev);
2474 out1:
2475 kfree(ppp);
2476 out:
2477 *retp = ret;
2478 return NULL;
2479 }
2480
2481 /*
2482 * Initialize a ppp_file structure.
2483 */
2484 static void
2485 init_ppp_file(struct ppp_file *pf, int kind)
2486 {
2487 pf->kind = kind;
2488 skb_queue_head_init(&pf->xq);
2489 skb_queue_head_init(&pf->rq);
2490 atomic_set(&pf->refcnt, 1);
2491 init_waitqueue_head(&pf->rwait);
2492 }
2493
2494 /*
2495 * Take down a ppp interface unit - called when the owning file
2496 * (the one that created the unit) is closed or detached.
2497 */
2498 static void ppp_shutdown_interface(struct ppp *ppp)
2499 {
2500 struct net_device *dev;
2501
2502 mutex_lock(&all_ppp_mutex);
2503 ppp_lock(ppp);
2504 dev = ppp->dev;
2505 ppp->dev = NULL;
2506 ppp_unlock(ppp);
2507 /* This will call dev_close() for us. */
2508 if (dev) {
2509 unregister_netdev(dev);
2510 free_netdev(dev);
2511 }
2512 cardmap_set(&all_ppp_units, ppp->file.index, NULL);
2513 ppp->file.dead = 1;
2514 ppp->owner = NULL;
2515 wake_up_interruptible(&ppp->file.rwait);
2516 mutex_unlock(&all_ppp_mutex);
2517 }
2518
2519 /*
2520 * Free the memory used by a ppp unit. This is only called once
2521 * there are no channels connected to the unit and no file structs
2522 * that reference the unit.
2523 */
2524 static void ppp_destroy_interface(struct ppp *ppp)
2525 {
2526 atomic_dec(&ppp_unit_count);
2527
2528 if (!ppp->file.dead || ppp->n_channels) {
2529 /* "can't happen" */
2530 printk(KERN_ERR "ppp: destroying ppp struct %p but dead=%d "
2531 "n_channels=%d !\n", ppp, ppp->file.dead,
2532 ppp->n_channels);
2533 return;
2534 }
2535
2536 ppp_ccp_closed(ppp);
2537 if (ppp->vj) {
2538 slhc_free(ppp->vj);
2539 ppp->vj = NULL;
2540 }
2541 skb_queue_purge(&ppp->file.xq);
2542 skb_queue_purge(&ppp->file.rq);
2543 #ifdef CONFIG_PPP_MULTILINK
2544 skb_queue_purge(&ppp->mrq);
2545 #endif /* CONFIG_PPP_MULTILINK */
2546 #ifdef CONFIG_PPP_FILTER
2547 kfree(ppp->pass_filter);
2548 ppp->pass_filter = NULL;
2549 kfree(ppp->active_filter);
2550 ppp->active_filter = NULL;
2551 #endif /* CONFIG_PPP_FILTER */
2552
2553 if (ppp->xmit_pending)
2554 kfree_skb(ppp->xmit_pending);
2555
2556 kfree(ppp);
2557 }
2558
2559 /*
2560 * Locate an existing ppp unit.
2561 * The caller should have locked the all_ppp_mutex.
2562 */
2563 static struct ppp *
2564 ppp_find_unit(int unit)
2565 {
2566 return cardmap_get(all_ppp_units, unit);
2567 }
2568
2569 /*
2570 * Locate an existing ppp channel.
2571 * The caller should have locked the all_channels_lock.
2572 * First we look in the new_channels list, then in the
2573 * all_channels list. If found in the new_channels list,
2574 * we move it to the all_channels list. This is for speed
2575 * when we have a lot of channels in use.
2576 */
2577 static struct channel *
2578 ppp_find_channel(int unit)
2579 {
2580 struct channel *pch;
2581
2582 list_for_each_entry(pch, &new_channels, list) {
2583 if (pch->file.index == unit) {
2584 list_move(&pch->list, &all_channels);
2585 return pch;
2586 }
2587 }
2588 list_for_each_entry(pch, &all_channels, list) {
2589 if (pch->file.index == unit)
2590 return pch;
2591 }
2592 return NULL;
2593 }
2594
2595 /*
2596 * Connect a PPP channel to a PPP interface unit.
2597 */
2598 static int
2599 ppp_connect_channel(struct channel *pch, int unit)
2600 {
2601 struct ppp *ppp;
2602 int ret = -ENXIO;
2603 int hdrlen;
2604
2605 mutex_lock(&all_ppp_mutex);
2606 ppp = ppp_find_unit(unit);
2607 if (ppp == 0)
2608 goto out;
2609 write_lock_bh(&pch->upl);
2610 ret = -EINVAL;
2611 if (pch->ppp != 0)
2612 goto outl;
2613
2614 ppp_lock(ppp);
2615 if (pch->file.hdrlen > ppp->file.hdrlen)
2616 ppp->file.hdrlen = pch->file.hdrlen;
2617 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2618 if (ppp->dev && hdrlen > ppp->dev->hard_header_len)
2619 ppp->dev->hard_header_len = hdrlen;
2620 list_add_tail(&pch->clist, &ppp->channels);
2621 ++ppp->n_channels;
2622 pch->ppp = ppp;
2623 atomic_inc(&ppp->file.refcnt);
2624 ppp_unlock(ppp);
2625 ret = 0;
2626
2627 outl:
2628 write_unlock_bh(&pch->upl);
2629 out:
2630 mutex_unlock(&all_ppp_mutex);
2631 return ret;
2632 }
2633
2634 /*
2635 * Disconnect a channel from its ppp unit.
2636 */
2637 static int
2638 ppp_disconnect_channel(struct channel *pch)
2639 {
2640 struct ppp *ppp;
2641 int err = -EINVAL;
2642
2643 write_lock_bh(&pch->upl);
2644 ppp = pch->ppp;
2645 pch->ppp = NULL;
2646 write_unlock_bh(&pch->upl);
2647 if (ppp != 0) {
2648 /* remove it from the ppp unit's list */
2649 ppp_lock(ppp);
2650 list_del(&pch->clist);
2651 if (--ppp->n_channels == 0)
2652 wake_up_interruptible(&ppp->file.rwait);
2653 ppp_unlock(ppp);
2654 if (atomic_dec_and_test(&ppp->file.refcnt))
2655 ppp_destroy_interface(ppp);
2656 err = 0;
2657 }
2658 return err;
2659 }
2660
2661 /*
2662 * Free up the resources used by a ppp channel.
2663 */
2664 static void ppp_destroy_channel(struct channel *pch)
2665 {
2666 atomic_dec(&channel_count);
2667
2668 if (!pch->file.dead) {
2669 /* "can't happen" */
2670 printk(KERN_ERR "ppp: destroying undead channel %p !\n",
2671 pch);
2672 return;
2673 }
2674 skb_queue_purge(&pch->file.xq);
2675 skb_queue_purge(&pch->file.rq);
2676 kfree(pch);
2677 }
2678
2679 static void __exit ppp_cleanup(void)
2680 {
2681 /* should never happen */
2682 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2683 printk(KERN_ERR "PPP: removing module but units remain!\n");
2684 cardmap_destroy(&all_ppp_units);
2685 unregister_chrdev(PPP_MAJOR, "ppp");
2686 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
2687 class_destroy(ppp_class);
2688 }
2689
2690 /*
2691 * Cardmap implementation.
2692 */
2693 static void *cardmap_get(struct cardmap *map, unsigned int nr)
2694 {
2695 struct cardmap *p;
2696 int i;
2697
2698 for (p = map; p != NULL; ) {
2699 if ((i = nr >> p->shift) >= CARDMAP_WIDTH)
2700 return NULL;
2701 if (p->shift == 0)
2702 return p->ptr[i];
2703 nr &= ~(CARDMAP_MASK << p->shift);
2704 p = p->ptr[i];
2705 }
2706 return NULL;
2707 }
2708
2709 static int cardmap_set(struct cardmap **pmap, unsigned int nr, void *ptr)
2710 {
2711 struct cardmap *p;
2712 int i;
2713
2714 p = *pmap;
2715 if (p == NULL || (nr >> p->shift) >= CARDMAP_WIDTH) {
2716 do {
2717 /* need a new top level */
2718 struct cardmap *np = kzalloc(sizeof(*np), GFP_KERNEL);
2719 if (!np)
2720 goto enomem;
2721 np->ptr[0] = p;
2722 if (p != NULL) {
2723 np->shift = p->shift + CARDMAP_ORDER;
2724 p->parent = np;
2725 } else
2726 np->shift = 0;
2727 p = np;
2728 } while ((nr >> p->shift) >= CARDMAP_WIDTH);
2729 *pmap = p;
2730 }
2731 while (p->shift > 0) {
2732 i = (nr >> p->shift) & CARDMAP_MASK;
2733 if (p->ptr[i] == NULL) {
2734 struct cardmap *np = kzalloc(sizeof(*np), GFP_KERNEL);
2735 if (!np)
2736 goto enomem;
2737 np->shift = p->shift - CARDMAP_ORDER;
2738 np->parent = p;
2739 p->ptr[i] = np;
2740 }
2741 if (ptr == NULL)
2742 clear_bit(i, &p->inuse);
2743 p = p->ptr[i];
2744 }
2745 i = nr & CARDMAP_MASK;
2746 p->ptr[i] = ptr;
2747 if (ptr != NULL)
2748 set_bit(i, &p->inuse);
2749 else
2750 clear_bit(i, &p->inuse);
2751 return 0;
2752 enomem:
2753 return -ENOMEM;
2754 }
2755
2756 static unsigned int cardmap_find_first_free(struct cardmap *map)
2757 {
2758 struct cardmap *p;
2759 unsigned int nr = 0;
2760 int i;
2761
2762 if ((p = map) == NULL)
2763 return 0;
2764 for (;;) {
2765 i = find_first_zero_bit(&p->inuse, CARDMAP_WIDTH);
2766 if (i >= CARDMAP_WIDTH) {
2767 if (p->parent == NULL)
2768 return CARDMAP_WIDTH << p->shift;
2769 p = p->parent;
2770 i = (nr >> p->shift) & CARDMAP_MASK;
2771 set_bit(i, &p->inuse);
2772 continue;
2773 }
2774 nr = (nr & (~CARDMAP_MASK << p->shift)) | (i << p->shift);
2775 if (p->shift == 0 || p->ptr[i] == NULL)
2776 return nr;
2777 p = p->ptr[i];
2778 }
2779 }
2780
2781 static void cardmap_destroy(struct cardmap **pmap)
2782 {
2783 struct cardmap *p, *np;
2784 int i;
2785
2786 for (p = *pmap; p != NULL; p = np) {
2787 if (p->shift != 0) {
2788 for (i = 0; i < CARDMAP_WIDTH; ++i)
2789 if (p->ptr[i] != NULL)
2790 break;
2791 if (i < CARDMAP_WIDTH) {
2792 np = p->ptr[i];
2793 p->ptr[i] = NULL;
2794 continue;
2795 }
2796 }
2797 np = p->parent;
2798 kfree(p);
2799 }
2800 *pmap = NULL;
2801 }
2802
2803 /* Module/initialization stuff */
2804
2805 module_init(ppp_init);
2806 module_exit(ppp_cleanup);
2807
2808 EXPORT_SYMBOL(ppp_register_channel);
2809 EXPORT_SYMBOL(ppp_unregister_channel);
2810 EXPORT_SYMBOL(ppp_channel_index);
2811 EXPORT_SYMBOL(ppp_unit_number);
2812 EXPORT_SYMBOL(ppp_input);
2813 EXPORT_SYMBOL(ppp_input_error);
2814 EXPORT_SYMBOL(ppp_output_wakeup);
2815 EXPORT_SYMBOL(ppp_register_compressor);
2816 EXPORT_SYMBOL(ppp_unregister_compressor);
2817 MODULE_LICENSE("GPL");
2818 MODULE_ALIAS_CHARDEV_MAJOR(PPP_MAJOR);
2819 MODULE_ALIAS("/dev/ppp");
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