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Fix dnotify/close race
[linux-2.6.22.y-op.git] / drivers / net / ppp_generic.c
blob9a81fed5aa6e4e10f2aeb2c39d366b9302f8a749
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_headroom(skb) < PPP_HDRLEN) {
903 struct sk_buff *ns;
904
905 ns = alloc_skb(skb->len + dev->hard_header_len, GFP_ATOMIC);
906 if (ns == 0)
907 goto outf;
908 skb_reserve(ns, dev->hard_header_len);
909 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
910 kfree_skb(skb);
911 skb = ns;
912 }
913 pp = skb_push(skb, 2);
914 proto = npindex_to_proto[npi];
915 pp[0] = proto >> 8;
916 pp[1] = proto;
917
918 netif_stop_queue(dev);
919 skb_queue_tail(&ppp->file.xq, skb);
920 ppp_xmit_process(ppp);
921 return 0;
922
923 outf:
924 kfree_skb(skb);
925 ++ppp->stats.tx_dropped;
926 return 0;
927 }
928
929 static struct net_device_stats *
930 ppp_net_stats(struct net_device *dev)
931 {
932 struct ppp *ppp = (struct ppp *) dev->priv;
933
934 return &ppp->stats;
935 }
936
937 static int
938 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
939 {
940 struct ppp *ppp = dev->priv;
941 int err = -EFAULT;
942 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
943 struct ppp_stats stats;
944 struct ppp_comp_stats cstats;
945 char *vers;
946
947 switch (cmd) {
948 case SIOCGPPPSTATS:
949 ppp_get_stats(ppp, &stats);
950 if (copy_to_user(addr, &stats, sizeof(stats)))
951 break;
952 err = 0;
953 break;
954
955 case SIOCGPPPCSTATS:
956 memset(&cstats, 0, sizeof(cstats));
957 if (ppp->xc_state != 0)
958 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
959 if (ppp->rc_state != 0)
960 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
961 if (copy_to_user(addr, &cstats, sizeof(cstats)))
962 break;
963 err = 0;
964 break;
965
966 case SIOCGPPPVER:
967 vers = PPP_VERSION;
968 if (copy_to_user(addr, vers, strlen(vers) + 1))
969 break;
970 err = 0;
971 break;
972
973 default:
974 err = -EINVAL;
975 }
976
977 return err;
978 }
979
980 static void ppp_setup(struct net_device *dev)
981 {
982 dev->hard_header_len = PPP_HDRLEN;
983 dev->mtu = PPP_MTU;
984 dev->addr_len = 0;
985 dev->tx_queue_len = 3;
986 dev->type = ARPHRD_PPP;
987 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
988 }
989
990 /*
991 * Transmit-side routines.
992 */
993
994 /*
995 * Called to do any work queued up on the transmit side
996 * that can now be done.
997 */
998 static void
999 ppp_xmit_process(struct ppp *ppp)
1000 {
1001 struct sk_buff *skb;
1002
1003 ppp_xmit_lock(ppp);
1004 if (ppp->dev != 0) {
1005 ppp_push(ppp);
1006 while (ppp->xmit_pending == 0
1007 && (skb = skb_dequeue(&ppp->file.xq)) != 0)
1008 ppp_send_frame(ppp, skb);
1009 /* If there's no work left to do, tell the core net
1010 code that we can accept some more. */
1011 if (ppp->xmit_pending == 0 && skb_peek(&ppp->file.xq) == 0)
1012 netif_wake_queue(ppp->dev);
1013 }
1014 ppp_xmit_unlock(ppp);
1015 }
1016
1017 static inline struct sk_buff *
1018 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1019 {
1020 struct sk_buff *new_skb;
1021 int len;
1022 int new_skb_size = ppp->dev->mtu +
1023 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1024 int compressor_skb_size = ppp->dev->mtu +
1025 ppp->xcomp->comp_extra + PPP_HDRLEN;
1026 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1027 if (!new_skb) {
1028 if (net_ratelimit())
1029 printk(KERN_ERR "PPP: no memory (comp pkt)\n");
1030 return NULL;
1031 }
1032 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1033 skb_reserve(new_skb,
1034 ppp->dev->hard_header_len - PPP_HDRLEN);
1035
1036 /* compressor still expects A/C bytes in hdr */
1037 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1038 new_skb->data, skb->len + 2,
1039 compressor_skb_size);
1040 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1041 kfree_skb(skb);
1042 skb = new_skb;
1043 skb_put(skb, len);
1044 skb_pull(skb, 2); /* pull off A/C bytes */
1045 } else if (len == 0) {
1046 /* didn't compress, or CCP not up yet */
1047 kfree_skb(new_skb);
1048 new_skb = skb;
1049 } else {
1050 /*
1051 * (len < 0)
1052 * MPPE requires that we do not send unencrypted
1053 * frames. The compressor will return -1 if we
1054 * should drop the frame. We cannot simply test
1055 * the compress_proto because MPPE and MPPC share
1056 * the same number.
1057 */
1058 if (net_ratelimit())
1059 printk(KERN_ERR "ppp: compressor dropped pkt\n");
1060 kfree_skb(skb);
1061 kfree_skb(new_skb);
1062 new_skb = NULL;
1063 }
1064 return new_skb;
1065 }
1066
1067 /*
1068 * Compress and send a frame.
1069 * The caller should have locked the xmit path,
1070 * and xmit_pending should be 0.
1071 */
1072 static void
1073 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1074 {
1075 int proto = PPP_PROTO(skb);
1076 struct sk_buff *new_skb;
1077 int len;
1078 unsigned char *cp;
1079
1080 if (proto < 0x8000) {
1081 #ifdef CONFIG_PPP_FILTER
1082 /* check if we should pass this packet */
1083 /* the filter instructions are constructed assuming
1084 a four-byte PPP header on each packet */
1085 *skb_push(skb, 2) = 1;
1086 if (ppp->pass_filter
1087 && sk_run_filter(skb, ppp->pass_filter,
1088 ppp->pass_len) == 0) {
1089 if (ppp->debug & 1)
1090 printk(KERN_DEBUG "PPP: outbound frame not passed\n");
1091 kfree_skb(skb);
1092 return;
1093 }
1094 /* if this packet passes the active filter, record the time */
1095 if (!(ppp->active_filter
1096 && sk_run_filter(skb, ppp->active_filter,
1097 ppp->active_len) == 0))
1098 ppp->last_xmit = jiffies;
1099 skb_pull(skb, 2);
1100 #else
1101 /* for data packets, record the time */
1102 ppp->last_xmit = jiffies;
1103 #endif /* CONFIG_PPP_FILTER */
1104 }
1105
1106 ++ppp->stats.tx_packets;
1107 ppp->stats.tx_bytes += skb->len - 2;
1108
1109 switch (proto) {
1110 case PPP_IP:
1111 if (ppp->vj == 0 || (ppp->flags & SC_COMP_TCP) == 0)
1112 break;
1113 /* try to do VJ TCP header compression */
1114 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1115 GFP_ATOMIC);
1116 if (new_skb == 0) {
1117 printk(KERN_ERR "PPP: no memory (VJ comp pkt)\n");
1118 goto drop;
1119 }
1120 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1121 cp = skb->data + 2;
1122 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1123 new_skb->data + 2, &cp,
1124 !(ppp->flags & SC_NO_TCP_CCID));
1125 if (cp == skb->data + 2) {
1126 /* didn't compress */
1127 kfree_skb(new_skb);
1128 } else {
1129 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1130 proto = PPP_VJC_COMP;
1131 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1132 } else {
1133 proto = PPP_VJC_UNCOMP;
1134 cp[0] = skb->data[2];
1135 }
1136 kfree_skb(skb);
1137 skb = new_skb;
1138 cp = skb_put(skb, len + 2);
1139 cp[0] = 0;
1140 cp[1] = proto;
1141 }
1142 break;
1143
1144 case PPP_CCP:
1145 /* peek at outbound CCP frames */
1146 ppp_ccp_peek(ppp, skb, 0);
1147 break;
1148 }
1149
1150 /* try to do packet compression */
1151 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state != 0
1152 && proto != PPP_LCP && proto != PPP_CCP) {
1153 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1154 if (net_ratelimit())
1155 printk(KERN_ERR "ppp: compression required but down - pkt dropped.\n");
1156 goto drop;
1157 }
1158 skb = pad_compress_skb(ppp, skb);
1159 if (!skb)
1160 goto drop;
1161 }
1162
1163 /*
1164 * If we are waiting for traffic (demand dialling),
1165 * queue it up for pppd to receive.
1166 */
1167 if (ppp->flags & SC_LOOP_TRAFFIC) {
1168 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1169 goto drop;
1170 skb_queue_tail(&ppp->file.rq, skb);
1171 wake_up_interruptible(&ppp->file.rwait);
1172 return;
1173 }
1174
1175 ppp->xmit_pending = skb;
1176 ppp_push(ppp);
1177 return;
1178
1179 drop:
1180 if (skb)
1181 kfree_skb(skb);
1182 ++ppp->stats.tx_errors;
1183 }
1184
1185 /*
1186 * Try to send the frame in xmit_pending.
1187 * The caller should have the xmit path locked.
1188 */
1189 static void
1190 ppp_push(struct ppp *ppp)
1191 {
1192 struct list_head *list;
1193 struct channel *pch;
1194 struct sk_buff *skb = ppp->xmit_pending;
1195
1196 if (skb == 0)
1197 return;
1198
1199 list = &ppp->channels;
1200 if (list_empty(list)) {
1201 /* nowhere to send the packet, just drop it */
1202 ppp->xmit_pending = NULL;
1203 kfree_skb(skb);
1204 return;
1205 }
1206
1207 if ((ppp->flags & SC_MULTILINK) == 0) {
1208 /* not doing multilink: send it down the first channel */
1209 list = list->next;
1210 pch = list_entry(list, struct channel, clist);
1211
1212 spin_lock_bh(&pch->downl);
1213 if (pch->chan) {
1214 if (pch->chan->ops->start_xmit(pch->chan, skb))
1215 ppp->xmit_pending = NULL;
1216 } else {
1217 /* channel got unregistered */
1218 kfree_skb(skb);
1219 ppp->xmit_pending = NULL;
1220 }
1221 spin_unlock_bh(&pch->downl);
1222 return;
1223 }
1224
1225 #ifdef CONFIG_PPP_MULTILINK
1226 /* Multilink: fragment the packet over as many links
1227 as can take the packet at the moment. */
1228 if (!ppp_mp_explode(ppp, skb))
1229 return;
1230 #endif /* CONFIG_PPP_MULTILINK */
1231
1232 ppp->xmit_pending = NULL;
1233 kfree_skb(skb);
1234 }
1235
1236 #ifdef CONFIG_PPP_MULTILINK
1237 /*
1238 * Divide a packet to be transmitted into fragments and
1239 * send them out the individual links.
1240 */
1241 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1242 {
1243 int len, fragsize;
1244 int i, bits, hdrlen, mtu;
1245 int flen;
1246 int navail, nfree;
1247 int nbigger;
1248 unsigned char *p, *q;
1249 struct list_head *list;
1250 struct channel *pch;
1251 struct sk_buff *frag;
1252 struct ppp_channel *chan;
1253
1254 nfree = 0; /* # channels which have no packet already queued */
1255 navail = 0; /* total # of usable channels (not deregistered) */
1256 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1257 i = 0;
1258 list_for_each_entry(pch, &ppp->channels, clist) {
1259 navail += pch->avail = (pch->chan != NULL);
1260 if (pch->avail) {
1261 if (skb_queue_empty(&pch->file.xq) ||
1262 !pch->had_frag) {
1263 pch->avail = 2;
1264 ++nfree;
1265 }
1266 if (!pch->had_frag && i < ppp->nxchan)
1267 ppp->nxchan = i;
1268 }
1269 ++i;
1270 }
1271
1272 /*
1273 * Don't start sending this packet unless at least half of
1274 * the channels are free. This gives much better TCP
1275 * performance if we have a lot of channels.
1276 */
1277 if (nfree == 0 || nfree < navail / 2)
1278 return 0; /* can't take now, leave it in xmit_pending */
1279
1280 /* Do protocol field compression (XXX this should be optional) */
1281 p = skb->data;
1282 len = skb->len;
1283 if (*p == 0) {
1284 ++p;
1285 --len;
1286 }
1287
1288 /*
1289 * Decide on fragment size.
1290 * We create a fragment for each free channel regardless of
1291 * how small they are (i.e. even 0 length) in order to minimize
1292 * the time that it will take to detect when a channel drops
1293 * a fragment.
1294 */
1295 fragsize = len;
1296 if (nfree > 1)
1297 fragsize = DIV_ROUND_UP(fragsize, nfree);
1298 /* nbigger channels get fragsize bytes, the rest get fragsize-1,
1299 except if nbigger==0, then they all get fragsize. */
1300 nbigger = len % nfree;
1301
1302 /* skip to the channel after the one we last used
1303 and start at that one */
1304 list = &ppp->channels;
1305 for (i = 0; i < ppp->nxchan; ++i) {
1306 list = list->next;
1307 if (list == &ppp->channels) {
1308 i = 0;
1309 break;
1310 }
1311 }
1312
1313 /* create a fragment for each channel */
1314 bits = B;
1315 while (nfree > 0 || len > 0) {
1316 list = list->next;
1317 if (list == &ppp->channels) {
1318 i = 0;
1319 continue;
1320 }
1321 pch = list_entry(list, struct channel, clist);
1322 ++i;
1323 if (!pch->avail)
1324 continue;
1325
1326 /*
1327 * Skip this channel if it has a fragment pending already and
1328 * we haven't given a fragment to all of the free channels.
1329 */
1330 if (pch->avail == 1) {
1331 if (nfree > 0)
1332 continue;
1333 } else {
1334 --nfree;
1335 pch->avail = 1;
1336 }
1337
1338 /* check the channel's mtu and whether it is still attached. */
1339 spin_lock_bh(&pch->downl);
1340 if (pch->chan == NULL) {
1341 /* can't use this channel, it's being deregistered */
1342 spin_unlock_bh(&pch->downl);
1343 pch->avail = 0;
1344 if (--navail == 0)
1345 break;
1346 continue;
1347 }
1348
1349 /*
1350 * Create a fragment for this channel of
1351 * min(max(mtu+2-hdrlen, 4), fragsize, len) bytes.
1352 * If mtu+2-hdrlen < 4, that is a ridiculously small
1353 * MTU, so we use mtu = 2 + hdrlen.
1354 */
1355 if (fragsize > len)
1356 fragsize = len;
1357 flen = fragsize;
1358 mtu = pch->chan->mtu + 2 - hdrlen;
1359 if (mtu < 4)
1360 mtu = 4;
1361 if (flen > mtu)
1362 flen = mtu;
1363 if (flen == len && nfree == 0)
1364 bits |= E;
1365 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1366 if (frag == 0)
1367 goto noskb;
1368 q = skb_put(frag, flen + hdrlen);
1369
1370 /* make the MP header */
1371 q[0] = PPP_MP >> 8;
1372 q[1] = PPP_MP;
1373 if (ppp->flags & SC_MP_XSHORTSEQ) {
1374 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1375 q[3] = ppp->nxseq;
1376 } else {
1377 q[2] = bits;
1378 q[3] = ppp->nxseq >> 16;
1379 q[4] = ppp->nxseq >> 8;
1380 q[5] = ppp->nxseq;
1381 }
1382
1383 /*
1384 * Copy the data in.
1385 * Unfortunately there is a bug in older versions of
1386 * the Linux PPP multilink reconstruction code where it
1387 * drops 0-length fragments. Therefore we make sure the
1388 * fragment has at least one byte of data. Any bytes
1389 * we add in this situation will end up as padding on the
1390 * end of the reconstructed packet.
1391 */
1392 if (flen == 0)
1393 *skb_put(frag, 1) = 0;
1394 else
1395 memcpy(q + hdrlen, p, flen);
1396
1397 /* try to send it down the channel */
1398 chan = pch->chan;
1399 if (!skb_queue_empty(&pch->file.xq) ||
1400 !chan->ops->start_xmit(chan, frag))
1401 skb_queue_tail(&pch->file.xq, frag);
1402 pch->had_frag = 1;
1403 p += flen;
1404 len -= flen;
1405 ++ppp->nxseq;
1406 bits = 0;
1407 spin_unlock_bh(&pch->downl);
1408
1409 if (--nbigger == 0 && fragsize > 0)
1410 --fragsize;
1411 }
1412 ppp->nxchan = i;
1413
1414 return 1;
1415
1416 noskb:
1417 spin_unlock_bh(&pch->downl);
1418 if (ppp->debug & 1)
1419 printk(KERN_ERR "PPP: no memory (fragment)\n");
1420 ++ppp->stats.tx_errors;
1421 ++ppp->nxseq;
1422 return 1; /* abandon the frame */
1423 }
1424 #endif /* CONFIG_PPP_MULTILINK */
1425
1426 /*
1427 * Try to send data out on a channel.
1428 */
1429 static void
1430 ppp_channel_push(struct channel *pch)
1431 {
1432 struct sk_buff *skb;
1433 struct ppp *ppp;
1434
1435 spin_lock_bh(&pch->downl);
1436 if (pch->chan != 0) {
1437 while (!skb_queue_empty(&pch->file.xq)) {
1438 skb = skb_dequeue(&pch->file.xq);
1439 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1440 /* put the packet back and try again later */
1441 skb_queue_head(&pch->file.xq, skb);
1442 break;
1443 }
1444 }
1445 } else {
1446 /* channel got deregistered */
1447 skb_queue_purge(&pch->file.xq);
1448 }
1449 spin_unlock_bh(&pch->downl);
1450 /* see if there is anything from the attached unit to be sent */
1451 if (skb_queue_empty(&pch->file.xq)) {
1452 read_lock_bh(&pch->upl);
1453 ppp = pch->ppp;
1454 if (ppp != 0)
1455 ppp_xmit_process(ppp);
1456 read_unlock_bh(&pch->upl);
1457 }
1458 }
1459
1460 /*
1461 * Receive-side routines.
1462 */
1463
1464 /* misuse a few fields of the skb for MP reconstruction */
1465 #define sequence priority
1466 #define BEbits cb[0]
1467
1468 static inline void
1469 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1470 {
1471 ppp_recv_lock(ppp);
1472 /* ppp->dev == 0 means interface is closing down */
1473 if (ppp->dev != 0)
1474 ppp_receive_frame(ppp, skb, pch);
1475 else
1476 kfree_skb(skb);
1477 ppp_recv_unlock(ppp);
1478 }
1479
1480 void
1481 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1482 {
1483 struct channel *pch = chan->ppp;
1484 int proto;
1485
1486 if (pch == 0 || skb->len == 0) {
1487 kfree_skb(skb);
1488 return;
1489 }
1490
1491 proto = PPP_PROTO(skb);
1492 read_lock_bh(&pch->upl);
1493 if (pch->ppp == 0 || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1494 /* put it on the channel queue */
1495 skb_queue_tail(&pch->file.rq, skb);
1496 /* drop old frames if queue too long */
1497 while (pch->file.rq.qlen > PPP_MAX_RQLEN
1498 && (skb = skb_dequeue(&pch->file.rq)) != 0)
1499 kfree_skb(skb);
1500 wake_up_interruptible(&pch->file.rwait);
1501 } else {
1502 ppp_do_recv(pch->ppp, skb, pch);
1503 }
1504 read_unlock_bh(&pch->upl);
1505 }
1506
1507 /* Put a 0-length skb in the receive queue as an error indication */
1508 void
1509 ppp_input_error(struct ppp_channel *chan, int code)
1510 {
1511 struct channel *pch = chan->ppp;
1512 struct sk_buff *skb;
1513
1514 if (pch == 0)
1515 return;
1516
1517 read_lock_bh(&pch->upl);
1518 if (pch->ppp != 0) {
1519 skb = alloc_skb(0, GFP_ATOMIC);
1520 if (skb != 0) {
1521 skb->len = 0; /* probably unnecessary */
1522 skb->cb[0] = code;
1523 ppp_do_recv(pch->ppp, skb, pch);
1524 }
1525 }
1526 read_unlock_bh(&pch->upl);
1527 }
1528
1529 /*
1530 * We come in here to process a received frame.
1531 * The receive side of the ppp unit is locked.
1532 */
1533 static void
1534 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1535 {
1536 if (skb->len >= 2) {
1537 #ifdef CONFIG_PPP_MULTILINK
1538 /* XXX do channel-level decompression here */
1539 if (PPP_PROTO(skb) == PPP_MP)
1540 ppp_receive_mp_frame(ppp, skb, pch);
1541 else
1542 #endif /* CONFIG_PPP_MULTILINK */
1543 ppp_receive_nonmp_frame(ppp, skb);
1544 return;
1545 }
1546
1547 if (skb->len > 0)
1548 /* note: a 0-length skb is used as an error indication */
1549 ++ppp->stats.rx_length_errors;
1550
1551 kfree_skb(skb);
1552 ppp_receive_error(ppp);
1553 }
1554
1555 static void
1556 ppp_receive_error(struct ppp *ppp)
1557 {
1558 ++ppp->stats.rx_errors;
1559 if (ppp->vj != 0)
1560 slhc_toss(ppp->vj);
1561 }
1562
1563 static void
1564 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1565 {
1566 struct sk_buff *ns;
1567 int proto, len, npi;
1568
1569 /*
1570 * Decompress the frame, if compressed.
1571 * Note that some decompressors need to see uncompressed frames
1572 * that come in as well as compressed frames.
1573 */
1574 if (ppp->rc_state != 0 && (ppp->rstate & SC_DECOMP_RUN)
1575 && (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1576 skb = ppp_decompress_frame(ppp, skb);
1577
1578 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1579 goto err;
1580
1581 proto = PPP_PROTO(skb);
1582 switch (proto) {
1583 case PPP_VJC_COMP:
1584 /* decompress VJ compressed packets */
1585 if (ppp->vj == 0 || (ppp->flags & SC_REJ_COMP_TCP))
1586 goto err;
1587
1588 if (skb_tailroom(skb) < 124) {
1589 /* copy to a new sk_buff with more tailroom */
1590 ns = dev_alloc_skb(skb->len + 128);
1591 if (ns == 0) {
1592 printk(KERN_ERR"PPP: no memory (VJ decomp)\n");
1593 goto err;
1594 }
1595 skb_reserve(ns, 2);
1596 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1597 kfree_skb(skb);
1598 skb = ns;
1599 }
1600 else
1601 skb->ip_summed = CHECKSUM_NONE;
1602
1603 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1604 if (len <= 0) {
1605 printk(KERN_DEBUG "PPP: VJ decompression error\n");
1606 goto err;
1607 }
1608 len += 2;
1609 if (len > skb->len)
1610 skb_put(skb, len - skb->len);
1611 else if (len < skb->len)
1612 skb_trim(skb, len);
1613 proto = PPP_IP;
1614 break;
1615
1616 case PPP_VJC_UNCOMP:
1617 if (ppp->vj == 0 || (ppp->flags & SC_REJ_COMP_TCP))
1618 goto err;
1619
1620 /* Until we fix the decompressor need to make sure
1621 * data portion is linear.
1622 */
1623 if (!pskb_may_pull(skb, skb->len))
1624 goto err;
1625
1626 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1627 printk(KERN_ERR "PPP: VJ uncompressed error\n");
1628 goto err;
1629 }
1630 proto = PPP_IP;
1631 break;
1632
1633 case PPP_CCP:
1634 ppp_ccp_peek(ppp, skb, 1);
1635 break;
1636 }
1637
1638 ++ppp->stats.rx_packets;
1639 ppp->stats.rx_bytes += skb->len - 2;
1640
1641 npi = proto_to_npindex(proto);
1642 if (npi < 0) {
1643 /* control or unknown frame - pass it to pppd */
1644 skb_queue_tail(&ppp->file.rq, skb);
1645 /* limit queue length by dropping old frames */
1646 while (ppp->file.rq.qlen > PPP_MAX_RQLEN
1647 && (skb = skb_dequeue(&ppp->file.rq)) != 0)
1648 kfree_skb(skb);
1649 /* wake up any process polling or blocking on read */
1650 wake_up_interruptible(&ppp->file.rwait);
1651
1652 } else {
1653 /* network protocol frame - give it to the kernel */
1654
1655 #ifdef CONFIG_PPP_FILTER
1656 /* check if the packet passes the pass and active filters */
1657 /* the filter instructions are constructed assuming
1658 a four-byte PPP header on each packet */
1659 *skb_push(skb, 2) = 0;
1660 if (ppp->pass_filter
1661 && sk_run_filter(skb, ppp->pass_filter,
1662 ppp->pass_len) == 0) {
1663 if (ppp->debug & 1)
1664 printk(KERN_DEBUG "PPP: inbound frame 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 ppp->last_recv = jiffies;
1675 #endif /* CONFIG_PPP_FILTER */
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 == 0) {
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) || 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->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 && seq_before(ppp->minseq, ppp->mrq.next->sequence))
1838 ppp->minseq = ppp->mrq.next->sequence;
1839
1840 /* Pull completed packets off the queue and receive them. */
1841 while ((skb = ppp_mp_reconstruct(ppp)) != 0)
1842 ppp_receive_nonmp_frame(ppp, skb);
1843
1844 return;
1845
1846 err:
1847 kfree_skb(skb);
1848 ppp_receive_error(ppp);
1849 }
1850
1851 /*
1852 * Insert a fragment on the MP reconstruction queue.
1853 * The queue is ordered by increasing sequence number.
1854 */
1855 static void
1856 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
1857 {
1858 struct sk_buff *p;
1859 struct sk_buff_head *list = &ppp->mrq;
1860 u32 seq = skb->sequence;
1861
1862 /* N.B. we don't need to lock the list lock because we have the
1863 ppp unit receive-side lock. */
1864 for (p = list->next; p != (struct sk_buff *)list; p = p->next)
1865 if (seq_before(seq, p->sequence))
1866 break;
1867 __skb_insert(skb, p->prev, p, list);
1868 }
1869
1870 /*
1871 * Reconstruct a packet from the MP fragment queue.
1872 * We go through increasing sequence numbers until we find a
1873 * complete packet, or we get to the sequence number for a fragment
1874 * which hasn't arrived but might still do so.
1875 */
1876 struct sk_buff *
1877 ppp_mp_reconstruct(struct ppp *ppp)
1878 {
1879 u32 seq = ppp->nextseq;
1880 u32 minseq = ppp->minseq;
1881 struct sk_buff_head *list = &ppp->mrq;
1882 struct sk_buff *p, *next;
1883 struct sk_buff *head, *tail;
1884 struct sk_buff *skb = NULL;
1885 int lost = 0, len = 0;
1886
1887 if (ppp->mrru == 0) /* do nothing until mrru is set */
1888 return NULL;
1889 head = list->next;
1890 tail = NULL;
1891 for (p = head; p != (struct sk_buff *) list; p = next) {
1892 next = p->next;
1893 if (seq_before(p->sequence, seq)) {
1894 /* this can't happen, anyway ignore the skb */
1895 printk(KERN_ERR "ppp_mp_reconstruct bad seq %u < %u\n",
1896 p->sequence, seq);
1897 head = next;
1898 continue;
1899 }
1900 if (p->sequence != seq) {
1901 /* Fragment `seq' is missing. If it is after
1902 minseq, it might arrive later, so stop here. */
1903 if (seq_after(seq, minseq))
1904 break;
1905 /* Fragment `seq' is lost, keep going. */
1906 lost = 1;
1907 seq = seq_before(minseq, p->sequence)?
1908 minseq + 1: p->sequence;
1909 next = p;
1910 continue;
1911 }
1912
1913 /*
1914 * At this point we know that all the fragments from
1915 * ppp->nextseq to seq are either present or lost.
1916 * Also, there are no complete packets in the queue
1917 * that have no missing fragments and end before this
1918 * fragment.
1919 */
1920
1921 /* B bit set indicates this fragment starts a packet */
1922 if (p->BEbits & B) {
1923 head = p;
1924 lost = 0;
1925 len = 0;
1926 }
1927
1928 len += p->len;
1929
1930 /* Got a complete packet yet? */
1931 if (lost == 0 && (p->BEbits & E) && (head->BEbits & B)) {
1932 if (len > ppp->mrru + 2) {
1933 ++ppp->stats.rx_length_errors;
1934 printk(KERN_DEBUG "PPP: reconstructed packet"
1935 " is too long (%d)\n", len);
1936 } else if (p == head) {
1937 /* fragment is complete packet - reuse skb */
1938 tail = p;
1939 skb = skb_get(p);
1940 break;
1941 } else if ((skb = dev_alloc_skb(len)) == NULL) {
1942 ++ppp->stats.rx_missed_errors;
1943 printk(KERN_DEBUG "PPP: no memory for "
1944 "reconstructed packet");
1945 } else {
1946 tail = p;
1947 break;
1948 }
1949 ppp->nextseq = seq + 1;
1950 }
1951
1952 /*
1953 * If this is the ending fragment of a packet,
1954 * and we haven't found a complete valid packet yet,
1955 * we can discard up to and including this fragment.
1956 */
1957 if (p->BEbits & E)
1958 head = next;
1959
1960 ++seq;
1961 }
1962
1963 /* If we have a complete packet, copy it all into one skb. */
1964 if (tail != NULL) {
1965 /* If we have discarded any fragments,
1966 signal a receive error. */
1967 if (head->sequence != ppp->nextseq) {
1968 if (ppp->debug & 1)
1969 printk(KERN_DEBUG " missed pkts %u..%u\n",
1970 ppp->nextseq, head->sequence-1);
1971 ++ppp->stats.rx_dropped;
1972 ppp_receive_error(ppp);
1973 }
1974
1975 if (head != tail)
1976 /* copy to a single skb */
1977 for (p = head; p != tail->next; p = p->next)
1978 skb_copy_bits(p, 0, skb_put(skb, p->len), p->len);
1979 ppp->nextseq = tail->sequence + 1;
1980 head = tail->next;
1981 }
1982
1983 /* Discard all the skbuffs that we have copied the data out of
1984 or that we can't use. */
1985 while ((p = list->next) != head) {
1986 __skb_unlink(p, list);
1987 kfree_skb(p);
1988 }
1989
1990 return skb;
1991 }
1992 #endif /* CONFIG_PPP_MULTILINK */
1993
1994 /*
1995 * Channel interface.
1996 */
1997
1998 /*
1999 * Create a new, unattached ppp channel.
2000 */
2001 int
2002 ppp_register_channel(struct ppp_channel *chan)
2003 {
2004 struct channel *pch;
2005
2006 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2007 if (pch == 0)
2008 return -ENOMEM;
2009 pch->ppp = NULL;
2010 pch->chan = chan;
2011 chan->ppp = pch;
2012 init_ppp_file(&pch->file, CHANNEL);
2013 pch->file.hdrlen = chan->hdrlen;
2014 #ifdef CONFIG_PPP_MULTILINK
2015 pch->lastseq = -1;
2016 #endif /* CONFIG_PPP_MULTILINK */
2017 init_rwsem(&pch->chan_sem);
2018 spin_lock_init(&pch->downl);
2019 rwlock_init(&pch->upl);
2020 spin_lock_bh(&all_channels_lock);
2021 pch->file.index = ++last_channel_index;
2022 list_add(&pch->list, &new_channels);
2023 atomic_inc(&channel_count);
2024 spin_unlock_bh(&all_channels_lock);
2025 return 0;
2026 }
2027
2028 /*
2029 * Return the index of a channel.
2030 */
2031 int ppp_channel_index(struct ppp_channel *chan)
2032 {
2033 struct channel *pch = chan->ppp;
2034
2035 if (pch != 0)
2036 return pch->file.index;
2037 return -1;
2038 }
2039
2040 /*
2041 * Return the PPP unit number to which a channel is connected.
2042 */
2043 int ppp_unit_number(struct ppp_channel *chan)
2044 {
2045 struct channel *pch = chan->ppp;
2046 int unit = -1;
2047
2048 if (pch != 0) {
2049 read_lock_bh(&pch->upl);
2050 if (pch->ppp != 0)
2051 unit = pch->ppp->file.index;
2052 read_unlock_bh(&pch->upl);
2053 }
2054 return unit;
2055 }
2056
2057 /*
2058 * Disconnect a channel from the generic layer.
2059 * This must be called in process context.
2060 */
2061 void
2062 ppp_unregister_channel(struct ppp_channel *chan)
2063 {
2064 struct channel *pch = chan->ppp;
2065
2066 if (pch == 0)
2067 return; /* should never happen */
2068 chan->ppp = NULL;
2069
2070 /*
2071 * This ensures that we have returned from any calls into the
2072 * the channel's start_xmit or ioctl routine before we proceed.
2073 */
2074 down_write(&pch->chan_sem);
2075 spin_lock_bh(&pch->downl);
2076 pch->chan = NULL;
2077 spin_unlock_bh(&pch->downl);
2078 up_write(&pch->chan_sem);
2079 ppp_disconnect_channel(pch);
2080 spin_lock_bh(&all_channels_lock);
2081 list_del(&pch->list);
2082 spin_unlock_bh(&all_channels_lock);
2083 pch->file.dead = 1;
2084 wake_up_interruptible(&pch->file.rwait);
2085 if (atomic_dec_and_test(&pch->file.refcnt))
2086 ppp_destroy_channel(pch);
2087 }
2088
2089 /*
2090 * Callback from a channel when it can accept more to transmit.
2091 * This should be called at BH/softirq level, not interrupt level.
2092 */
2093 void
2094 ppp_output_wakeup(struct ppp_channel *chan)
2095 {
2096 struct channel *pch = chan->ppp;
2097
2098 if (pch == 0)
2099 return;
2100 ppp_channel_push(pch);
2101 }
2102
2103 /*
2104 * Compression control.
2105 */
2106
2107 /* Process the PPPIOCSCOMPRESS ioctl. */
2108 static int
2109 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2110 {
2111 int err;
2112 struct compressor *cp, *ocomp;
2113 struct ppp_option_data data;
2114 void *state, *ostate;
2115 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2116
2117 err = -EFAULT;
2118 if (copy_from_user(&data, (void __user *) arg, sizeof(data))
2119 || (data.length <= CCP_MAX_OPTION_LENGTH
2120 && copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2121 goto out;
2122 err = -EINVAL;
2123 if (data.length > CCP_MAX_OPTION_LENGTH
2124 || ccp_option[1] < 2 || ccp_option[1] > data.length)
2125 goto out;
2126
2127 cp = find_compressor(ccp_option[0]);
2128 #ifdef CONFIG_KMOD
2129 if (cp == 0) {
2130 request_module("ppp-compress-%d", ccp_option[0]);
2131 cp = find_compressor(ccp_option[0]);
2132 }
2133 #endif /* CONFIG_KMOD */
2134 if (cp == 0)
2135 goto out;
2136
2137 err = -ENOBUFS;
2138 if (data.transmit) {
2139 state = cp->comp_alloc(ccp_option, data.length);
2140 if (state != 0) {
2141 ppp_xmit_lock(ppp);
2142 ppp->xstate &= ~SC_COMP_RUN;
2143 ocomp = ppp->xcomp;
2144 ostate = ppp->xc_state;
2145 ppp->xcomp = cp;
2146 ppp->xc_state = state;
2147 ppp_xmit_unlock(ppp);
2148 if (ostate != 0) {
2149 ocomp->comp_free(ostate);
2150 module_put(ocomp->owner);
2151 }
2152 err = 0;
2153 } else
2154 module_put(cp->owner);
2155
2156 } else {
2157 state = cp->decomp_alloc(ccp_option, data.length);
2158 if (state != 0) {
2159 ppp_recv_lock(ppp);
2160 ppp->rstate &= ~SC_DECOMP_RUN;
2161 ocomp = ppp->rcomp;
2162 ostate = ppp->rc_state;
2163 ppp->rcomp = cp;
2164 ppp->rc_state = state;
2165 ppp_recv_unlock(ppp);
2166 if (ostate != 0) {
2167 ocomp->decomp_free(ostate);
2168 module_put(ocomp->owner);
2169 }
2170 err = 0;
2171 } else
2172 module_put(cp->owner);
2173 }
2174
2175 out:
2176 return err;
2177 }
2178
2179 /*
2180 * Look at a CCP packet and update our state accordingly.
2181 * We assume the caller has the xmit or recv path locked.
2182 */
2183 static void
2184 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2185 {
2186 unsigned char *dp;
2187 int len;
2188
2189 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2190 return; /* no header */
2191 dp = skb->data + 2;
2192
2193 switch (CCP_CODE(dp)) {
2194 case CCP_CONFREQ:
2195
2196 /* A ConfReq starts negotiation of compression
2197 * in one direction of transmission,
2198 * and hence brings it down...but which way?
2199 *
2200 * Remember:
2201 * A ConfReq indicates what the sender would like to receive
2202 */
2203 if(inbound)
2204 /* He is proposing what I should send */
2205 ppp->xstate &= ~SC_COMP_RUN;
2206 else
2207 /* I am proposing to what he should send */
2208 ppp->rstate &= ~SC_DECOMP_RUN;
2209
2210 break;
2211
2212 case CCP_TERMREQ:
2213 case CCP_TERMACK:
2214 /*
2215 * CCP is going down, both directions of transmission
2216 */
2217 ppp->rstate &= ~SC_DECOMP_RUN;
2218 ppp->xstate &= ~SC_COMP_RUN;
2219 break;
2220
2221 case CCP_CONFACK:
2222 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2223 break;
2224 len = CCP_LENGTH(dp);
2225 if (!pskb_may_pull(skb, len + 2))
2226 return; /* too short */
2227 dp += CCP_HDRLEN;
2228 len -= CCP_HDRLEN;
2229 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2230 break;
2231 if (inbound) {
2232 /* we will start receiving compressed packets */
2233 if (ppp->rc_state == 0)
2234 break;
2235 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2236 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2237 ppp->rstate |= SC_DECOMP_RUN;
2238 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2239 }
2240 } else {
2241 /* we will soon start sending compressed packets */
2242 if (ppp->xc_state == 0)
2243 break;
2244 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2245 ppp->file.index, 0, ppp->debug))
2246 ppp->xstate |= SC_COMP_RUN;
2247 }
2248 break;
2249
2250 case CCP_RESETACK:
2251 /* reset the [de]compressor */
2252 if ((ppp->flags & SC_CCP_UP) == 0)
2253 break;
2254 if (inbound) {
2255 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2256 ppp->rcomp->decomp_reset(ppp->rc_state);
2257 ppp->rstate &= ~SC_DC_ERROR;
2258 }
2259 } else {
2260 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2261 ppp->xcomp->comp_reset(ppp->xc_state);
2262 }
2263 break;
2264 }
2265 }
2266
2267 /* Free up compression resources. */
2268 static void
2269 ppp_ccp_closed(struct ppp *ppp)
2270 {
2271 void *xstate, *rstate;
2272 struct compressor *xcomp, *rcomp;
2273
2274 ppp_lock(ppp);
2275 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2276 ppp->xstate = 0;
2277 xcomp = ppp->xcomp;
2278 xstate = ppp->xc_state;
2279 ppp->xc_state = NULL;
2280 ppp->rstate = 0;
2281 rcomp = ppp->rcomp;
2282 rstate = ppp->rc_state;
2283 ppp->rc_state = NULL;
2284 ppp_unlock(ppp);
2285
2286 if (xstate) {
2287 xcomp->comp_free(xstate);
2288 module_put(xcomp->owner);
2289 }
2290 if (rstate) {
2291 rcomp->decomp_free(rstate);
2292 module_put(rcomp->owner);
2293 }
2294 }
2295
2296 /* List of compressors. */
2297 static LIST_HEAD(compressor_list);
2298 static DEFINE_SPINLOCK(compressor_list_lock);
2299
2300 struct compressor_entry {
2301 struct list_head list;
2302 struct compressor *comp;
2303 };
2304
2305 static struct compressor_entry *
2306 find_comp_entry(int proto)
2307 {
2308 struct compressor_entry *ce;
2309
2310 list_for_each_entry(ce, &compressor_list, list) {
2311 if (ce->comp->compress_proto == proto)
2312 return ce;
2313 }
2314 return NULL;
2315 }
2316
2317 /* Register a compressor */
2318 int
2319 ppp_register_compressor(struct compressor *cp)
2320 {
2321 struct compressor_entry *ce;
2322 int ret;
2323 spin_lock(&compressor_list_lock);
2324 ret = -EEXIST;
2325 if (find_comp_entry(cp->compress_proto) != 0)
2326 goto out;
2327 ret = -ENOMEM;
2328 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2329 if (ce == 0)
2330 goto out;
2331 ret = 0;
2332 ce->comp = cp;
2333 list_add(&ce->list, &compressor_list);
2334 out:
2335 spin_unlock(&compressor_list_lock);
2336 return ret;
2337 }
2338
2339 /* Unregister a compressor */
2340 void
2341 ppp_unregister_compressor(struct compressor *cp)
2342 {
2343 struct compressor_entry *ce;
2344
2345 spin_lock(&compressor_list_lock);
2346 ce = find_comp_entry(cp->compress_proto);
2347 if (ce != 0 && ce->comp == cp) {
2348 list_del(&ce->list);
2349 kfree(ce);
2350 }
2351 spin_unlock(&compressor_list_lock);
2352 }
2353
2354 /* Find a compressor. */
2355 static struct compressor *
2356 find_compressor(int type)
2357 {
2358 struct compressor_entry *ce;
2359 struct compressor *cp = NULL;
2360
2361 spin_lock(&compressor_list_lock);
2362 ce = find_comp_entry(type);
2363 if (ce != 0) {
2364 cp = ce->comp;
2365 if (!try_module_get(cp->owner))
2366 cp = NULL;
2367 }
2368 spin_unlock(&compressor_list_lock);
2369 return cp;
2370 }
2371
2372 /*
2373 * Miscelleneous stuff.
2374 */
2375
2376 static void
2377 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2378 {
2379 struct slcompress *vj = ppp->vj;
2380
2381 memset(st, 0, sizeof(*st));
2382 st->p.ppp_ipackets = ppp->stats.rx_packets;
2383 st->p.ppp_ierrors = ppp->stats.rx_errors;
2384 st->p.ppp_ibytes = ppp->stats.rx_bytes;
2385 st->p.ppp_opackets = ppp->stats.tx_packets;
2386 st->p.ppp_oerrors = ppp->stats.tx_errors;
2387 st->p.ppp_obytes = ppp->stats.tx_bytes;
2388 if (vj == 0)
2389 return;
2390 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2391 st->vj.vjs_compressed = vj->sls_o_compressed;
2392 st->vj.vjs_searches = vj->sls_o_searches;
2393 st->vj.vjs_misses = vj->sls_o_misses;
2394 st->vj.vjs_errorin = vj->sls_i_error;
2395 st->vj.vjs_tossed = vj->sls_i_tossed;
2396 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2397 st->vj.vjs_compressedin = vj->sls_i_compressed;
2398 }
2399
2400 /*
2401 * Stuff for handling the lists of ppp units and channels
2402 * and for initialization.
2403 */
2404
2405 /*
2406 * Create a new ppp interface unit. Fails if it can't allocate memory
2407 * or if there is already a unit with the requested number.
2408 * unit == -1 means allocate a new number.
2409 */
2410 static struct ppp *
2411 ppp_create_interface(int unit, int *retp)
2412 {
2413 struct ppp *ppp;
2414 struct net_device *dev = NULL;
2415 int ret = -ENOMEM;
2416 int i;
2417
2418 ppp = kzalloc(sizeof(struct ppp), GFP_KERNEL);
2419 if (!ppp)
2420 goto out;
2421 dev = alloc_netdev(0, "", ppp_setup);
2422 if (!dev)
2423 goto out1;
2424
2425 ppp->mru = PPP_MRU;
2426 init_ppp_file(&ppp->file, INTERFACE);
2427 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2428 for (i = 0; i < NUM_NP; ++i)
2429 ppp->npmode[i] = NPMODE_PASS;
2430 INIT_LIST_HEAD(&ppp->channels);
2431 spin_lock_init(&ppp->rlock);
2432 spin_lock_init(&ppp->wlock);
2433 #ifdef CONFIG_PPP_MULTILINK
2434 ppp->minseq = -1;
2435 skb_queue_head_init(&ppp->mrq);
2436 #endif /* CONFIG_PPP_MULTILINK */
2437 ppp->dev = dev;
2438 dev->priv = ppp;
2439
2440 dev->hard_start_xmit = ppp_start_xmit;
2441 dev->get_stats = ppp_net_stats;
2442 dev->do_ioctl = ppp_net_ioctl;
2443
2444 ret = -EEXIST;
2445 mutex_lock(&all_ppp_mutex);
2446 if (unit < 0)
2447 unit = cardmap_find_first_free(all_ppp_units);
2448 else if (cardmap_get(all_ppp_units, unit) != NULL)
2449 goto out2; /* unit already exists */
2450
2451 /* Initialize the new ppp unit */
2452 ppp->file.index = unit;
2453 sprintf(dev->name, "ppp%d", unit);
2454
2455 ret = register_netdev(dev);
2456 if (ret != 0) {
2457 printk(KERN_ERR "PPP: couldn't register device %s (%d)\n",
2458 dev->name, ret);
2459 goto out2;
2460 }
2461
2462 atomic_inc(&ppp_unit_count);
2463 ret = cardmap_set(&all_ppp_units, unit, ppp);
2464 if (ret != 0)
2465 goto out3;
2466
2467 mutex_unlock(&all_ppp_mutex);
2468 *retp = 0;
2469 return ppp;
2470
2471 out3:
2472 atomic_dec(&ppp_unit_count);
2473 out2:
2474 mutex_unlock(&all_ppp_mutex);
2475 free_netdev(dev);
2476 out1:
2477 kfree(ppp);
2478 out:
2479 *retp = ret;
2480 return NULL;
2481 }
2482
2483 /*
2484 * Initialize a ppp_file structure.
2485 */
2486 static void
2487 init_ppp_file(struct ppp_file *pf, int kind)
2488 {
2489 pf->kind = kind;
2490 skb_queue_head_init(&pf->xq);
2491 skb_queue_head_init(&pf->rq);
2492 atomic_set(&pf->refcnt, 1);
2493 init_waitqueue_head(&pf->rwait);
2494 }
2495
2496 /*
2497 * Take down a ppp interface unit - called when the owning file
2498 * (the one that created the unit) is closed or detached.
2499 */
2500 static void ppp_shutdown_interface(struct ppp *ppp)
2501 {
2502 struct net_device *dev;
2503
2504 mutex_lock(&all_ppp_mutex);
2505 ppp_lock(ppp);
2506 dev = ppp->dev;
2507 ppp->dev = NULL;
2508 ppp_unlock(ppp);
2509 /* This will call dev_close() for us. */
2510 if (dev) {
2511 unregister_netdev(dev);
2512 free_netdev(dev);
2513 }
2514 cardmap_set(&all_ppp_units, ppp->file.index, NULL);
2515 ppp->file.dead = 1;
2516 ppp->owner = NULL;
2517 wake_up_interruptible(&ppp->file.rwait);
2518 mutex_unlock(&all_ppp_mutex);
2519 }
2520
2521 /*
2522 * Free the memory used by a ppp unit. This is only called once
2523 * there are no channels connected to the unit and no file structs
2524 * that reference the unit.
2525 */
2526 static void ppp_destroy_interface(struct ppp *ppp)
2527 {
2528 atomic_dec(&ppp_unit_count);
2529
2530 if (!ppp->file.dead || ppp->n_channels) {
2531 /* "can't happen" */
2532 printk(KERN_ERR "ppp: destroying ppp struct %p but dead=%d "
2533 "n_channels=%d !\n", ppp, ppp->file.dead,
2534 ppp->n_channels);
2535 return;
2536 }
2537
2538 ppp_ccp_closed(ppp);
2539 if (ppp->vj) {
2540 slhc_free(ppp->vj);
2541 ppp->vj = NULL;
2542 }
2543 skb_queue_purge(&ppp->file.xq);
2544 skb_queue_purge(&ppp->file.rq);
2545 #ifdef CONFIG_PPP_MULTILINK
2546 skb_queue_purge(&ppp->mrq);
2547 #endif /* CONFIG_PPP_MULTILINK */
2548 #ifdef CONFIG_PPP_FILTER
2549 kfree(ppp->pass_filter);
2550 ppp->pass_filter = NULL;
2551 kfree(ppp->active_filter);
2552 ppp->active_filter = NULL;
2553 #endif /* CONFIG_PPP_FILTER */
2554
2555 if (ppp->xmit_pending)
2556 kfree_skb(ppp->xmit_pending);
2557
2558 kfree(ppp);
2559 }
2560
2561 /*
2562 * Locate an existing ppp unit.
2563 * The caller should have locked the all_ppp_mutex.
2564 */
2565 static struct ppp *
2566 ppp_find_unit(int unit)
2567 {
2568 return cardmap_get(all_ppp_units, unit);
2569 }
2570
2571 /*
2572 * Locate an existing ppp channel.
2573 * The caller should have locked the all_channels_lock.
2574 * First we look in the new_channels list, then in the
2575 * all_channels list. If found in the new_channels list,
2576 * we move it to the all_channels list. This is for speed
2577 * when we have a lot of channels in use.
2578 */
2579 static struct channel *
2580 ppp_find_channel(int unit)
2581 {
2582 struct channel *pch;
2583
2584 list_for_each_entry(pch, &new_channels, list) {
2585 if (pch->file.index == unit) {
2586 list_move(&pch->list, &all_channels);
2587 return pch;
2588 }
2589 }
2590 list_for_each_entry(pch, &all_channels, list) {
2591 if (pch->file.index == unit)
2592 return pch;
2593 }
2594 return NULL;
2595 }
2596
2597 /*
2598 * Connect a PPP channel to a PPP interface unit.
2599 */
2600 static int
2601 ppp_connect_channel(struct channel *pch, int unit)
2602 {
2603 struct ppp *ppp;
2604 int ret = -ENXIO;
2605 int hdrlen;
2606
2607 mutex_lock(&all_ppp_mutex);
2608 ppp = ppp_find_unit(unit);
2609 if (ppp == 0)
2610 goto out;
2611 write_lock_bh(&pch->upl);
2612 ret = -EINVAL;
2613 if (pch->ppp != 0)
2614 goto outl;
2615
2616 ppp_lock(ppp);
2617 if (pch->file.hdrlen > ppp->file.hdrlen)
2618 ppp->file.hdrlen = pch->file.hdrlen;
2619 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2620 if (ppp->dev && hdrlen > ppp->dev->hard_header_len)
2621 ppp->dev->hard_header_len = hdrlen;
2622 list_add_tail(&pch->clist, &ppp->channels);
2623 ++ppp->n_channels;
2624 pch->ppp = ppp;
2625 atomic_inc(&ppp->file.refcnt);
2626 ppp_unlock(ppp);
2627 ret = 0;
2628
2629 outl:
2630 write_unlock_bh(&pch->upl);
2631 out:
2632 mutex_unlock(&all_ppp_mutex);
2633 return ret;
2634 }
2635
2636 /*
2637 * Disconnect a channel from its ppp unit.
2638 */
2639 static int
2640 ppp_disconnect_channel(struct channel *pch)
2641 {
2642 struct ppp *ppp;
2643 int err = -EINVAL;
2644
2645 write_lock_bh(&pch->upl);
2646 ppp = pch->ppp;
2647 pch->ppp = NULL;
2648 write_unlock_bh(&pch->upl);
2649 if (ppp != 0) {
2650 /* remove it from the ppp unit's list */
2651 ppp_lock(ppp);
2652 list_del(&pch->clist);
2653 if (--ppp->n_channels == 0)
2654 wake_up_interruptible(&ppp->file.rwait);
2655 ppp_unlock(ppp);
2656 if (atomic_dec_and_test(&ppp->file.refcnt))
2657 ppp_destroy_interface(ppp);
2658 err = 0;
2659 }
2660 return err;
2661 }
2662
2663 /*
2664 * Free up the resources used by a ppp channel.
2665 */
2666 static void ppp_destroy_channel(struct channel *pch)
2667 {
2668 atomic_dec(&channel_count);
2669
2670 if (!pch->file.dead) {
2671 /* "can't happen" */
2672 printk(KERN_ERR "ppp: destroying undead channel %p !\n",
2673 pch);
2674 return;
2675 }
2676 skb_queue_purge(&pch->file.xq);
2677 skb_queue_purge(&pch->file.rq);
2678 kfree(pch);
2679 }
2680
2681 static void __exit ppp_cleanup(void)
2682 {
2683 /* should never happen */
2684 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2685 printk(KERN_ERR "PPP: removing module but units remain!\n");
2686 cardmap_destroy(&all_ppp_units);
2687 if (unregister_chrdev(PPP_MAJOR, "ppp") != 0)
2688 printk(KERN_ERR "PPP: failed to unregister PPP device\n");
2689 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
2690 class_destroy(ppp_class);
2691 }
2692
2693 /*
2694 * Cardmap implementation.
2695 */
2696 static void *cardmap_get(struct cardmap *map, unsigned int nr)
2697 {
2698 struct cardmap *p;
2699 int i;
2700
2701 for (p = map; p != NULL; ) {
2702 if ((i = nr >> p->shift) >= CARDMAP_WIDTH)
2703 return NULL;
2704 if (p->shift == 0)
2705 return p->ptr[i];
2706 nr &= ~(CARDMAP_MASK << p->shift);
2707 p = p->ptr[i];
2708 }
2709 return NULL;
2710 }
2711
2712 static int cardmap_set(struct cardmap **pmap, unsigned int nr, void *ptr)
2713 {
2714 struct cardmap *p;
2715 int i;
2716
2717 p = *pmap;
2718 if (p == NULL || (nr >> p->shift) >= CARDMAP_WIDTH) {
2719 do {
2720 /* need a new top level */
2721 struct cardmap *np = kzalloc(sizeof(*np), GFP_KERNEL);
2722 if (!np)
2723 goto enomem;
2724 np->ptr[0] = p;
2725 if (p != NULL) {
2726 np->shift = p->shift + CARDMAP_ORDER;
2727 p->parent = np;
2728 } else
2729 np->shift = 0;
2730 p = np;
2731 } while ((nr >> p->shift) >= CARDMAP_WIDTH);
2732 *pmap = p;
2733 }
2734 while (p->shift > 0) {
2735 i = (nr >> p->shift) & CARDMAP_MASK;
2736 if (p->ptr[i] == NULL) {
2737 struct cardmap *np = kzalloc(sizeof(*np), GFP_KERNEL);
2738 if (!np)
2739 goto enomem;
2740 np->shift = p->shift - CARDMAP_ORDER;
2741 np->parent = p;
2742 p->ptr[i] = np;
2743 }
2744 if (ptr == NULL)
2745 clear_bit(i, &p->inuse);
2746 p = p->ptr[i];
2747 }
2748 i = nr & CARDMAP_MASK;
2749 p->ptr[i] = ptr;
2750 if (ptr != NULL)
2751 set_bit(i, &p->inuse);
2752 else
2753 clear_bit(i, &p->inuse);
2754 return 0;
2755 enomem:
2756 return -ENOMEM;
2757 }
2758
2759 static unsigned int cardmap_find_first_free(struct cardmap *map)
2760 {
2761 struct cardmap *p;
2762 unsigned int nr = 0;
2763 int i;
2764
2765 if ((p = map) == NULL)
2766 return 0;
2767 for (;;) {
2768 i = find_first_zero_bit(&p->inuse, CARDMAP_WIDTH);
2769 if (i >= CARDMAP_WIDTH) {
2770 if (p->parent == NULL)
2771 return CARDMAP_WIDTH << p->shift;
2772 p = p->parent;
2773 i = (nr >> p->shift) & CARDMAP_MASK;
2774 set_bit(i, &p->inuse);
2775 continue;
2776 }
2777 nr = (nr & (~CARDMAP_MASK << p->shift)) | (i << p->shift);
2778 if (p->shift == 0 || p->ptr[i] == NULL)
2779 return nr;
2780 p = p->ptr[i];
2781 }
2782 }
2783
2784 static void cardmap_destroy(struct cardmap **pmap)
2785 {
2786 struct cardmap *p, *np;
2787 int i;
2788
2789 for (p = *pmap; p != NULL; p = np) {
2790 if (p->shift != 0) {
2791 for (i = 0; i < CARDMAP_WIDTH; ++i)
2792 if (p->ptr[i] != NULL)
2793 break;
2794 if (i < CARDMAP_WIDTH) {
2795 np = p->ptr[i];
2796 p->ptr[i] = NULL;
2797 continue;
2798 }
2799 }
2800 np = p->parent;
2801 kfree(p);
2802 }
2803 *pmap = NULL;
2804 }
2805
2806 /* Module/initialization stuff */
2807
2808 module_init(ppp_init);
2809 module_exit(ppp_cleanup);
2810
2811 EXPORT_SYMBOL(ppp_register_channel);
2812 EXPORT_SYMBOL(ppp_unregister_channel);
2813 EXPORT_SYMBOL(ppp_channel_index);
2814 EXPORT_SYMBOL(ppp_unit_number);
2815 EXPORT_SYMBOL(ppp_input);
2816 EXPORT_SYMBOL(ppp_input_error);
2817 EXPORT_SYMBOL(ppp_output_wakeup);
2818 EXPORT_SYMBOL(ppp_register_compressor);
2819 EXPORT_SYMBOL(ppp_unregister_compressor);
2820 MODULE_LICENSE("GPL");
2821 MODULE_ALIAS_CHARDEV_MAJOR(PPP_MAJOR);
2822 MODULE_ALIAS("/dev/ppp");
linux v2.6.22.y-op