?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
ipv6 addrconf: Introduce addrconf_is_prefix_route() helper.
[linux-2.6/cjktty.git] / drivers / net / ppp_generic.c
blobc926bf0b190efd6d9abe3cba36a477102731f4f8
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 #ifdef CONFIG_PPP_FILTER
127 struct sock_filter *pass_filter; /* filter for packets to pass */
128 struct sock_filter *active_filter;/* filter for pkts to reset idle */
129 unsigned pass_len, active_len;
130 #endif /* CONFIG_PPP_FILTER */
131 };
132
133 /*
134 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
135 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
136 * SC_MUST_COMP
137 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
138 * Bits in xstate: SC_COMP_RUN
139 */
140 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
141 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
142 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
143
144 /*
145 * Private data structure for each channel.
146 * This includes the data structure used for multilink.
147 */
148 struct channel {
149 struct ppp_file file; /* stuff for read/write/poll */
150 struct list_head list; /* link in all/new_channels list */
151 struct ppp_channel *chan; /* public channel data structure */
152 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
153 spinlock_t downl; /* protects `chan', file.xq dequeue */
154 struct ppp *ppp; /* ppp unit we're connected to */
155 struct list_head clist; /* link in list of channels per unit */
156 rwlock_t upl; /* protects `ppp' */
157 #ifdef CONFIG_PPP_MULTILINK
158 u8 avail; /* flag used in multilink stuff */
159 u8 had_frag; /* >= 1 fragments have been sent */
160 u32 lastseq; /* MP: last sequence # received */
161 #endif /* CONFIG_PPP_MULTILINK */
162 };
163
164 /*
165 * SMP locking issues:
166 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
167 * list and the ppp.n_channels field, you need to take both locks
168 * before you modify them.
169 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
170 * channel.downl.
171 */
172
173 /*
174 * A cardmap represents a mapping from unsigned integers to pointers,
175 * and provides a fast "find lowest unused number" operation.
176 * It uses a broad (32-way) tree with a bitmap at each level.
177 * It is designed to be space-efficient for small numbers of entries
178 * and time-efficient for large numbers of entries.
179 */
180 #define CARDMAP_ORDER 5
181 #define CARDMAP_WIDTH (1U << CARDMAP_ORDER)
182 #define CARDMAP_MASK (CARDMAP_WIDTH - 1)
183
184 struct cardmap {
185 int shift;
186 unsigned long inuse;
187 struct cardmap *parent;
188 void *ptr[CARDMAP_WIDTH];
189 };
190 static void *cardmap_get(struct cardmap *map, unsigned int nr);
191 static int cardmap_set(struct cardmap **map, unsigned int nr, void *ptr);
192 static unsigned int cardmap_find_first_free(struct cardmap *map);
193 static void cardmap_destroy(struct cardmap **map);
194
195 /*
196 * all_ppp_mutex protects the all_ppp_units mapping.
197 * It also ensures that finding a ppp unit in the all_ppp_units map
198 * and updating its file.refcnt field is atomic.
199 */
200 static DEFINE_MUTEX(all_ppp_mutex);
201 static struct cardmap *all_ppp_units;
202 static atomic_t ppp_unit_count = ATOMIC_INIT(0);
203
204 /*
205 * all_channels_lock protects all_channels and last_channel_index,
206 * and the atomicity of find a channel and updating its file.refcnt
207 * field.
208 */
209 static DEFINE_SPINLOCK(all_channels_lock);
210 static LIST_HEAD(all_channels);
211 static LIST_HEAD(new_channels);
212 static int last_channel_index;
213 static atomic_t channel_count = ATOMIC_INIT(0);
214
215 /* Get the PPP protocol number from a skb */
216 #define PPP_PROTO(skb) (((skb)->data[0] << 8) + (skb)->data[1])
217
218 /* We limit the length of ppp->file.rq to this (arbitrary) value */
219 #define PPP_MAX_RQLEN 32
220
221 /*
222 * Maximum number of multilink fragments queued up.
223 * This has to be large enough to cope with the maximum latency of
224 * the slowest channel relative to the others. Strictly it should
225 * depend on the number of channels and their characteristics.
226 */
227 #define PPP_MP_MAX_QLEN 128
228
229 /* Multilink header bits. */
230 #define B 0x80 /* this fragment begins a packet */
231 #define E 0x40 /* this fragment ends a packet */
232
233 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */
234 #define seq_before(a, b) ((s32)((a) - (b)) < 0)
235 #define seq_after(a, b) ((s32)((a) - (b)) > 0)
236
237 /* Prototypes. */
238 static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file,
239 unsigned int cmd, unsigned long arg);
240 static void ppp_xmit_process(struct ppp *ppp);
241 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
242 static void ppp_push(struct ppp *ppp);
243 static void ppp_channel_push(struct channel *pch);
244 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
245 struct channel *pch);
246 static void ppp_receive_error(struct ppp *ppp);
247 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
248 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
249 struct sk_buff *skb);
250 #ifdef CONFIG_PPP_MULTILINK
251 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
252 struct channel *pch);
253 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
254 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
255 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
256 #endif /* CONFIG_PPP_MULTILINK */
257 static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
258 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
259 static void ppp_ccp_closed(struct ppp *ppp);
260 static struct compressor *find_compressor(int type);
261 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
262 static struct ppp *ppp_create_interface(int unit, int *retp);
263 static void init_ppp_file(struct ppp_file *pf, int kind);
264 static void ppp_shutdown_interface(struct ppp *ppp);
265 static void ppp_destroy_interface(struct ppp *ppp);
266 static struct ppp *ppp_find_unit(int unit);
267 static struct channel *ppp_find_channel(int unit);
268 static int ppp_connect_channel(struct channel *pch, int unit);
269 static int ppp_disconnect_channel(struct channel *pch);
270 static void ppp_destroy_channel(struct channel *pch);
271
272 static struct class *ppp_class;
273
274 /* Translates a PPP protocol number to a NP index (NP == network protocol) */
275 static inline int proto_to_npindex(int proto)
276 {
277 switch (proto) {
278 case PPP_IP:
279 return NP_IP;
280 case PPP_IPV6:
281 return NP_IPV6;
282 case PPP_IPX:
283 return NP_IPX;
284 case PPP_AT:
285 return NP_AT;
286 case PPP_MPLS_UC:
287 return NP_MPLS_UC;
288 case PPP_MPLS_MC:
289 return NP_MPLS_MC;
290 }
291 return -EINVAL;
292 }
293
294 /* Translates an NP index into a PPP protocol number */
295 static const int npindex_to_proto[NUM_NP] = {
296 PPP_IP,
297 PPP_IPV6,
298 PPP_IPX,
299 PPP_AT,
300 PPP_MPLS_UC,
301 PPP_MPLS_MC,
302 };
303
304 /* Translates an ethertype into an NP index */
305 static inline int ethertype_to_npindex(int ethertype)
306 {
307 switch (ethertype) {
308 case ETH_P_IP:
309 return NP_IP;
310 case ETH_P_IPV6:
311 return NP_IPV6;
312 case ETH_P_IPX:
313 return NP_IPX;
314 case ETH_P_PPPTALK:
315 case ETH_P_ATALK:
316 return NP_AT;
317 case ETH_P_MPLS_UC:
318 return NP_MPLS_UC;
319 case ETH_P_MPLS_MC:
320 return NP_MPLS_MC;
321 }
322 return -1;
323 }
324
325 /* Translates an NP index into an ethertype */
326 static const int npindex_to_ethertype[NUM_NP] = {
327 ETH_P_IP,
328 ETH_P_IPV6,
329 ETH_P_IPX,
330 ETH_P_PPPTALK,
331 ETH_P_MPLS_UC,
332 ETH_P_MPLS_MC,
333 };
334
335 /*
336 * Locking shorthand.
337 */
338 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
339 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
340 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
341 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
342 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
343 ppp_recv_lock(ppp); } while (0)
344 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
345 ppp_xmit_unlock(ppp); } while (0)
346
347 /*
348 * /dev/ppp device routines.
349 * The /dev/ppp device is used by pppd to control the ppp unit.
350 * It supports the read, write, ioctl and poll functions.
351 * Open instances of /dev/ppp can be in one of three states:
352 * unattached, attached to a ppp unit, or attached to a ppp channel.
353 */
354 static int ppp_open(struct inode *inode, struct file *file)
355 {
356 /*
357 * This could (should?) be enforced by the permissions on /dev/ppp.
358 */
359 if (!capable(CAP_NET_ADMIN))
360 return -EPERM;
361 return 0;
362 }
363
364 static int ppp_release(struct inode *unused, struct file *file)
365 {
366 struct ppp_file *pf = file->private_data;
367 struct ppp *ppp;
368
369 if (pf) {
370 file->private_data = NULL;
371 if (pf->kind == INTERFACE) {
372 ppp = PF_TO_PPP(pf);
373 if (file == ppp->owner)
374 ppp_shutdown_interface(ppp);
375 }
376 if (atomic_dec_and_test(&pf->refcnt)) {
377 switch (pf->kind) {
378 case INTERFACE:
379 ppp_destroy_interface(PF_TO_PPP(pf));
380 break;
381 case CHANNEL:
382 ppp_destroy_channel(PF_TO_CHANNEL(pf));
383 break;
384 }
385 }
386 }
387 return 0;
388 }
389
390 static ssize_t ppp_read(struct file *file, char __user *buf,
391 size_t count, loff_t *ppos)
392 {
393 struct ppp_file *pf = file->private_data;
394 DECLARE_WAITQUEUE(wait, current);
395 ssize_t ret;
396 struct sk_buff *skb = NULL;
397
398 ret = count;
399
400 if (!pf)
401 return -ENXIO;
402 add_wait_queue(&pf->rwait, &wait);
403 for (;;) {
404 set_current_state(TASK_INTERRUPTIBLE);
405 skb = skb_dequeue(&pf->rq);
406 if (skb)
407 break;
408 ret = 0;
409 if (pf->dead)
410 break;
411 if (pf->kind == INTERFACE) {
412 /*
413 * Return 0 (EOF) on an interface that has no
414 * channels connected, unless it is looping
415 * network traffic (demand mode).
416 */
417 struct ppp *ppp = PF_TO_PPP(pf);
418 if (ppp->n_channels == 0
419 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
420 break;
421 }
422 ret = -EAGAIN;
423 if (file->f_flags & O_NONBLOCK)
424 break;
425 ret = -ERESTARTSYS;
426 if (signal_pending(current))
427 break;
428 schedule();
429 }
430 set_current_state(TASK_RUNNING);
431 remove_wait_queue(&pf->rwait, &wait);
432
433 if (!skb)
434 goto out;
435
436 ret = -EOVERFLOW;
437 if (skb->len > count)
438 goto outf;
439 ret = -EFAULT;
440 if (copy_to_user(buf, skb->data, skb->len))
441 goto outf;
442 ret = skb->len;
443
444 outf:
445 kfree_skb(skb);
446 out:
447 return ret;
448 }
449
450 static ssize_t ppp_write(struct file *file, const char __user *buf,
451 size_t count, loff_t *ppos)
452 {
453 struct ppp_file *pf = file->private_data;
454 struct sk_buff *skb;
455 ssize_t ret;
456
457 if (!pf)
458 return -ENXIO;
459 ret = -ENOMEM;
460 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
461 if (!skb)
462 goto out;
463 skb_reserve(skb, pf->hdrlen);
464 ret = -EFAULT;
465 if (copy_from_user(skb_put(skb, count), buf, count)) {
466 kfree_skb(skb);
467 goto out;
468 }
469
470 skb_queue_tail(&pf->xq, skb);
471
472 switch (pf->kind) {
473 case INTERFACE:
474 ppp_xmit_process(PF_TO_PPP(pf));
475 break;
476 case CHANNEL:
477 ppp_channel_push(PF_TO_CHANNEL(pf));
478 break;
479 }
480
481 ret = count;
482
483 out:
484 return ret;
485 }
486
487 /* No kernel lock - fine */
488 static unsigned int ppp_poll(struct file *file, poll_table *wait)
489 {
490 struct ppp_file *pf = file->private_data;
491 unsigned int mask;
492
493 if (!pf)
494 return 0;
495 poll_wait(file, &pf->rwait, wait);
496 mask = POLLOUT | POLLWRNORM;
497 if (skb_peek(&pf->rq))
498 mask |= POLLIN | POLLRDNORM;
499 if (pf->dead)
500 mask |= POLLHUP;
501 else if (pf->kind == INTERFACE) {
502 /* see comment in ppp_read */
503 struct ppp *ppp = PF_TO_PPP(pf);
504 if (ppp->n_channels == 0
505 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
506 mask |= POLLIN | POLLRDNORM;
507 }
508
509 return mask;
510 }
511
512 #ifdef CONFIG_PPP_FILTER
513 static int get_filter(void __user *arg, struct sock_filter **p)
514 {
515 struct sock_fprog uprog;
516 struct sock_filter *code = NULL;
517 int len, err;
518
519 if (copy_from_user(&uprog, arg, sizeof(uprog)))
520 return -EFAULT;
521
522 if (!uprog.len) {
523 *p = NULL;
524 return 0;
525 }
526
527 len = uprog.len * sizeof(struct sock_filter);
528 code = kmalloc(len, GFP_KERNEL);
529 if (code == NULL)
530 return -ENOMEM;
531
532 if (copy_from_user(code, uprog.filter, len)) {
533 kfree(code);
534 return -EFAULT;
535 }
536
537 err = sk_chk_filter(code, uprog.len);
538 if (err) {
539 kfree(code);
540 return err;
541 }
542
543 *p = code;
544 return uprog.len;
545 }
546 #endif /* CONFIG_PPP_FILTER */
547
548 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
549 {
550 struct ppp_file *pf = file->private_data;
551 struct ppp *ppp;
552 int err = -EFAULT, val, val2, i;
553 struct ppp_idle idle;
554 struct npioctl npi;
555 int unit, cflags;
556 struct slcompress *vj;
557 void __user *argp = (void __user *)arg;
558 int __user *p = argp;
559
560 if (!pf)
561 return ppp_unattached_ioctl(pf, file, cmd, arg);
562
563 if (cmd == PPPIOCDETACH) {
564 /*
565 * We have to be careful here... if the file descriptor
566 * has been dup'd, we could have another process in the
567 * middle of a poll using the same file *, so we had
568 * better not free the interface data structures -
569 * instead we fail the ioctl. Even in this case, we
570 * shut down the interface if we are the owner of it.
571 * Actually, we should get rid of PPPIOCDETACH, userland
572 * (i.e. pppd) could achieve the same effect by closing
573 * this fd and reopening /dev/ppp.
574 */
575 err = -EINVAL;
576 lock_kernel();
577 if (pf->kind == INTERFACE) {
578 ppp = PF_TO_PPP(pf);
579 if (file == ppp->owner)
580 ppp_shutdown_interface(ppp);
581 }
582 if (atomic_read(&file->f_count) <= 2) {
583 ppp_release(NULL, file);
584 err = 0;
585 } else
586 printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%d\n",
587 atomic_read(&file->f_count));
588 unlock_kernel();
589 return err;
590 }
591
592 if (pf->kind == CHANNEL) {
593 struct channel *pch;
594 struct ppp_channel *chan;
595
596 lock_kernel();
597 pch = PF_TO_CHANNEL(pf);
598
599 switch (cmd) {
600 case PPPIOCCONNECT:
601 if (get_user(unit, p))
602 break;
603 err = ppp_connect_channel(pch, unit);
604 break;
605
606 case PPPIOCDISCONN:
607 err = ppp_disconnect_channel(pch);
608 break;
609
610 default:
611 down_read(&pch->chan_sem);
612 chan = pch->chan;
613 err = -ENOTTY;
614 if (chan && chan->ops->ioctl)
615 err = chan->ops->ioctl(chan, cmd, arg);
616 up_read(&pch->chan_sem);
617 }
618 unlock_kernel();
619 return err;
620 }
621
622 if (pf->kind != INTERFACE) {
623 /* can't happen */
624 printk(KERN_ERR "PPP: not interface or channel??\n");
625 return -EINVAL;
626 }
627
628 lock_kernel();
629 ppp = PF_TO_PPP(pf);
630 switch (cmd) {
631 case PPPIOCSMRU:
632 if (get_user(val, p))
633 break;
634 ppp->mru = val;
635 err = 0;
636 break;
637
638 case PPPIOCSFLAGS:
639 if (get_user(val, p))
640 break;
641 ppp_lock(ppp);
642 cflags = ppp->flags & ~val;
643 ppp->flags = val & SC_FLAG_BITS;
644 ppp_unlock(ppp);
645 if (cflags & SC_CCP_OPEN)
646 ppp_ccp_closed(ppp);
647 err = 0;
648 break;
649
650 case PPPIOCGFLAGS:
651 val = ppp->flags | ppp->xstate | ppp->rstate;
652 if (put_user(val, p))
653 break;
654 err = 0;
655 break;
656
657 case PPPIOCSCOMPRESS:
658 err = ppp_set_compress(ppp, arg);
659 break;
660
661 case PPPIOCGUNIT:
662 if (put_user(ppp->file.index, p))
663 break;
664 err = 0;
665 break;
666
667 case PPPIOCSDEBUG:
668 if (get_user(val, p))
669 break;
670 ppp->debug = val;
671 err = 0;
672 break;
673
674 case PPPIOCGDEBUG:
675 if (put_user(ppp->debug, p))
676 break;
677 err = 0;
678 break;
679
680 case PPPIOCGIDLE:
681 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
682 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
683 if (copy_to_user(argp, &idle, sizeof(idle)))
684 break;
685 err = 0;
686 break;
687
688 case PPPIOCSMAXCID:
689 if (get_user(val, p))
690 break;
691 val2 = 15;
692 if ((val >> 16) != 0) {
693 val2 = val >> 16;
694 val &= 0xffff;
695 }
696 vj = slhc_init(val2+1, val+1);
697 if (!vj) {
698 printk(KERN_ERR "PPP: no memory (VJ compressor)\n");
699 err = -ENOMEM;
700 break;
701 }
702 ppp_lock(ppp);
703 if (ppp->vj)
704 slhc_free(ppp->vj);
705 ppp->vj = vj;
706 ppp_unlock(ppp);
707 err = 0;
708 break;
709
710 case PPPIOCGNPMODE:
711 case PPPIOCSNPMODE:
712 if (copy_from_user(&npi, argp, sizeof(npi)))
713 break;
714 err = proto_to_npindex(npi.protocol);
715 if (err < 0)
716 break;
717 i = err;
718 if (cmd == PPPIOCGNPMODE) {
719 err = -EFAULT;
720 npi.mode = ppp->npmode[i];
721 if (copy_to_user(argp, &npi, sizeof(npi)))
722 break;
723 } else {
724 ppp->npmode[i] = npi.mode;
725 /* we may be able to transmit more packets now (??) */
726 netif_wake_queue(ppp->dev);
727 }
728 err = 0;
729 break;
730
731 #ifdef CONFIG_PPP_FILTER
732 case PPPIOCSPASS:
733 {
734 struct sock_filter *code;
735 err = get_filter(argp, &code);
736 if (err >= 0) {
737 ppp_lock(ppp);
738 kfree(ppp->pass_filter);
739 ppp->pass_filter = code;
740 ppp->pass_len = err;
741 ppp_unlock(ppp);
742 err = 0;
743 }
744 break;
745 }
746 case PPPIOCSACTIVE:
747 {
748 struct sock_filter *code;
749 err = get_filter(argp, &code);
750 if (err >= 0) {
751 ppp_lock(ppp);
752 kfree(ppp->active_filter);
753 ppp->active_filter = code;
754 ppp->active_len = err;
755 ppp_unlock(ppp);
756 err = 0;
757 }
758 break;
759 }
760 #endif /* CONFIG_PPP_FILTER */
761
762 #ifdef CONFIG_PPP_MULTILINK
763 case PPPIOCSMRRU:
764 if (get_user(val, p))
765 break;
766 ppp_recv_lock(ppp);
767 ppp->mrru = val;
768 ppp_recv_unlock(ppp);
769 err = 0;
770 break;
771 #endif /* CONFIG_PPP_MULTILINK */
772
773 default:
774 err = -ENOTTY;
775 }
776 unlock_kernel();
777 return err;
778 }
779
780 static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file,
781 unsigned int cmd, unsigned long arg)
782 {
783 int unit, err = -EFAULT;
784 struct ppp *ppp;
785 struct channel *chan;
786 int __user *p = (int __user *)arg;
787
788 lock_kernel();
789 switch (cmd) {
790 case PPPIOCNEWUNIT:
791 /* Create a new ppp unit */
792 if (get_user(unit, p))
793 break;
794 ppp = ppp_create_interface(unit, &err);
795 if (!ppp)
796 break;
797 file->private_data = &ppp->file;
798 ppp->owner = file;
799 err = -EFAULT;
800 if (put_user(ppp->file.index, p))
801 break;
802 err = 0;
803 break;
804
805 case PPPIOCATTACH:
806 /* Attach to an existing ppp unit */
807 if (get_user(unit, p))
808 break;
809 mutex_lock(&all_ppp_mutex);
810 err = -ENXIO;
811 ppp = ppp_find_unit(unit);
812 if (ppp) {
813 atomic_inc(&ppp->file.refcnt);
814 file->private_data = &ppp->file;
815 err = 0;
816 }
817 mutex_unlock(&all_ppp_mutex);
818 break;
819
820 case PPPIOCATTCHAN:
821 if (get_user(unit, p))
822 break;
823 spin_lock_bh(&all_channels_lock);
824 err = -ENXIO;
825 chan = ppp_find_channel(unit);
826 if (chan) {
827 atomic_inc(&chan->file.refcnt);
828 file->private_data = &chan->file;
829 err = 0;
830 }
831 spin_unlock_bh(&all_channels_lock);
832 break;
833
834 default:
835 err = -ENOTTY;
836 }
837 unlock_kernel();
838 return err;
839 }
840
841 static const struct file_operations ppp_device_fops = {
842 .owner = THIS_MODULE,
843 .read = ppp_read,
844 .write = ppp_write,
845 .poll = ppp_poll,
846 .unlocked_ioctl = ppp_ioctl,
847 .open = ppp_open,
848 .release = ppp_release
849 };
850
851 #define PPP_MAJOR 108
852
853 /* Called at boot time if ppp is compiled into the kernel,
854 or at module load time (from init_module) if compiled as a module. */
855 static int __init ppp_init(void)
856 {
857 int err;
858
859 printk(KERN_INFO "PPP generic driver version " PPP_VERSION "\n");
860 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
861 if (!err) {
862 ppp_class = class_create(THIS_MODULE, "ppp");
863 if (IS_ERR(ppp_class)) {
864 err = PTR_ERR(ppp_class);
865 goto out_chrdev;
866 }
867 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), "ppp");
868 }
869
870 out:
871 if (err)
872 printk(KERN_ERR "failed to register PPP device (%d)\n", err);
873 return err;
874
875 out_chrdev:
876 unregister_chrdev(PPP_MAJOR, "ppp");
877 goto out;
878 }
879
880 /*
881 * Network interface unit routines.
882 */
883 static int
884 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
885 {
886 struct ppp *ppp = (struct ppp *) dev->priv;
887 int npi, proto;
888 unsigned char *pp;
889
890 npi = ethertype_to_npindex(ntohs(skb->protocol));
891 if (npi < 0)
892 goto outf;
893
894 /* Drop, accept or reject the packet */
895 switch (ppp->npmode[npi]) {
896 case NPMODE_PASS:
897 break;
898 case NPMODE_QUEUE:
899 /* it would be nice to have a way to tell the network
900 system to queue this one up for later. */
901 goto outf;
902 case NPMODE_DROP:
903 case NPMODE_ERROR:
904 goto outf;
905 }
906
907 /* Put the 2-byte PPP protocol number on the front,
908 making sure there is room for the address and control fields. */
909 if (skb_cow_head(skb, PPP_HDRLEN))
910 goto outf;
911
912 pp = skb_push(skb, 2);
913 proto = npindex_to_proto[npi];
914 pp[0] = proto >> 8;
915 pp[1] = proto;
916
917 netif_stop_queue(dev);
918 skb_queue_tail(&ppp->file.xq, skb);
919 ppp_xmit_process(ppp);
920 return 0;
921
922 outf:
923 kfree_skb(skb);
924 ++ppp->dev->stats.tx_dropped;
925 return 0;
926 }
927
928 static int
929 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
930 {
931 struct ppp *ppp = dev->priv;
932 int err = -EFAULT;
933 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
934 struct ppp_stats stats;
935 struct ppp_comp_stats cstats;
936 char *vers;
937
938 switch (cmd) {
939 case SIOCGPPPSTATS:
940 ppp_get_stats(ppp, &stats);
941 if (copy_to_user(addr, &stats, sizeof(stats)))
942 break;
943 err = 0;
944 break;
945
946 case SIOCGPPPCSTATS:
947 memset(&cstats, 0, sizeof(cstats));
948 if (ppp->xc_state)
949 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
950 if (ppp->rc_state)
951 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
952 if (copy_to_user(addr, &cstats, sizeof(cstats)))
953 break;
954 err = 0;
955 break;
956
957 case SIOCGPPPVER:
958 vers = PPP_VERSION;
959 if (copy_to_user(addr, vers, strlen(vers) + 1))
960 break;
961 err = 0;
962 break;
963
964 default:
965 err = -EINVAL;
966 }
967
968 return err;
969 }
970
971 static void ppp_setup(struct net_device *dev)
972 {
973 dev->hard_header_len = PPP_HDRLEN;
974 dev->mtu = PPP_MTU;
975 dev->addr_len = 0;
976 dev->tx_queue_len = 3;
977 dev->type = ARPHRD_PPP;
978 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
979 }
980
981 /*
982 * Transmit-side routines.
983 */
984
985 /*
986 * Called to do any work queued up on the transmit side
987 * that can now be done.
988 */
989 static void
990 ppp_xmit_process(struct ppp *ppp)
991 {
992 struct sk_buff *skb;
993
994 ppp_xmit_lock(ppp);
995 if (ppp->dev) {
996 ppp_push(ppp);
997 while (!ppp->xmit_pending
998 && (skb = skb_dequeue(&ppp->file.xq)))
999 ppp_send_frame(ppp, skb);
1000 /* If there's no work left to do, tell the core net
1001 code that we can accept some more. */
1002 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1003 netif_wake_queue(ppp->dev);
1004 }
1005 ppp_xmit_unlock(ppp);
1006 }
1007
1008 static inline struct sk_buff *
1009 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1010 {
1011 struct sk_buff *new_skb;
1012 int len;
1013 int new_skb_size = ppp->dev->mtu +
1014 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1015 int compressor_skb_size = ppp->dev->mtu +
1016 ppp->xcomp->comp_extra + PPP_HDRLEN;
1017 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1018 if (!new_skb) {
1019 if (net_ratelimit())
1020 printk(KERN_ERR "PPP: no memory (comp pkt)\n");
1021 return NULL;
1022 }
1023 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1024 skb_reserve(new_skb,
1025 ppp->dev->hard_header_len - PPP_HDRLEN);
1026
1027 /* compressor still expects A/C bytes in hdr */
1028 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1029 new_skb->data, skb->len + 2,
1030 compressor_skb_size);
1031 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1032 kfree_skb(skb);
1033 skb = new_skb;
1034 skb_put(skb, len);
1035 skb_pull(skb, 2); /* pull off A/C bytes */
1036 } else if (len == 0) {
1037 /* didn't compress, or CCP not up yet */
1038 kfree_skb(new_skb);
1039 new_skb = skb;
1040 } else {
1041 /*
1042 * (len < 0)
1043 * MPPE requires that we do not send unencrypted
1044 * frames. The compressor will return -1 if we
1045 * should drop the frame. We cannot simply test
1046 * the compress_proto because MPPE and MPPC share
1047 * the same number.
1048 */
1049 if (net_ratelimit())
1050 printk(KERN_ERR "ppp: compressor dropped pkt\n");
1051 kfree_skb(skb);
1052 kfree_skb(new_skb);
1053 new_skb = NULL;
1054 }
1055 return new_skb;
1056 }
1057
1058 /*
1059 * Compress and send a frame.
1060 * The caller should have locked the xmit path,
1061 * and xmit_pending should be 0.
1062 */
1063 static void
1064 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1065 {
1066 int proto = PPP_PROTO(skb);
1067 struct sk_buff *new_skb;
1068 int len;
1069 unsigned char *cp;
1070
1071 if (proto < 0x8000) {
1072 #ifdef CONFIG_PPP_FILTER
1073 /* check if we should pass this packet */
1074 /* the filter instructions are constructed assuming
1075 a four-byte PPP header on each packet */
1076 *skb_push(skb, 2) = 1;
1077 if (ppp->pass_filter
1078 && sk_run_filter(skb, ppp->pass_filter,
1079 ppp->pass_len) == 0) {
1080 if (ppp->debug & 1)
1081 printk(KERN_DEBUG "PPP: outbound frame not passed\n");
1082 kfree_skb(skb);
1083 return;
1084 }
1085 /* if this packet passes the active filter, record the time */
1086 if (!(ppp->active_filter
1087 && sk_run_filter(skb, ppp->active_filter,
1088 ppp->active_len) == 0))
1089 ppp->last_xmit = jiffies;
1090 skb_pull(skb, 2);
1091 #else
1092 /* for data packets, record the time */
1093 ppp->last_xmit = jiffies;
1094 #endif /* CONFIG_PPP_FILTER */
1095 }
1096
1097 ++ppp->dev->stats.tx_packets;
1098 ppp->dev->stats.tx_bytes += skb->len - 2;
1099
1100 switch (proto) {
1101 case PPP_IP:
1102 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1103 break;
1104 /* try to do VJ TCP header compression */
1105 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1106 GFP_ATOMIC);
1107 if (!new_skb) {
1108 printk(KERN_ERR "PPP: no memory (VJ comp pkt)\n");
1109 goto drop;
1110 }
1111 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1112 cp = skb->data + 2;
1113 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1114 new_skb->data + 2, &cp,
1115 !(ppp->flags & SC_NO_TCP_CCID));
1116 if (cp == skb->data + 2) {
1117 /* didn't compress */
1118 kfree_skb(new_skb);
1119 } else {
1120 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1121 proto = PPP_VJC_COMP;
1122 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1123 } else {
1124 proto = PPP_VJC_UNCOMP;
1125 cp[0] = skb->data[2];
1126 }
1127 kfree_skb(skb);
1128 skb = new_skb;
1129 cp = skb_put(skb, len + 2);
1130 cp[0] = 0;
1131 cp[1] = proto;
1132 }
1133 break;
1134
1135 case PPP_CCP:
1136 /* peek at outbound CCP frames */
1137 ppp_ccp_peek(ppp, skb, 0);
1138 break;
1139 }
1140
1141 /* try to do packet compression */
1142 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state
1143 && proto != PPP_LCP && proto != PPP_CCP) {
1144 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1145 if (net_ratelimit())
1146 printk(KERN_ERR "ppp: compression required but down - pkt dropped.\n");
1147 goto drop;
1148 }
1149 skb = pad_compress_skb(ppp, skb);
1150 if (!skb)
1151 goto drop;
1152 }
1153
1154 /*
1155 * If we are waiting for traffic (demand dialling),
1156 * queue it up for pppd to receive.
1157 */
1158 if (ppp->flags & SC_LOOP_TRAFFIC) {
1159 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1160 goto drop;
1161 skb_queue_tail(&ppp->file.rq, skb);
1162 wake_up_interruptible(&ppp->file.rwait);
1163 return;
1164 }
1165
1166 ppp->xmit_pending = skb;
1167 ppp_push(ppp);
1168 return;
1169
1170 drop:
1171 if (skb)
1172 kfree_skb(skb);
1173 ++ppp->dev->stats.tx_errors;
1174 }
1175
1176 /*
1177 * Try to send the frame in xmit_pending.
1178 * The caller should have the xmit path locked.
1179 */
1180 static void
1181 ppp_push(struct ppp *ppp)
1182 {
1183 struct list_head *list;
1184 struct channel *pch;
1185 struct sk_buff *skb = ppp->xmit_pending;
1186
1187 if (!skb)
1188 return;
1189
1190 list = &ppp->channels;
1191 if (list_empty(list)) {
1192 /* nowhere to send the packet, just drop it */
1193 ppp->xmit_pending = NULL;
1194 kfree_skb(skb);
1195 return;
1196 }
1197
1198 if ((ppp->flags & SC_MULTILINK) == 0) {
1199 /* not doing multilink: send it down the first channel */
1200 list = list->next;
1201 pch = list_entry(list, struct channel, clist);
1202
1203 spin_lock_bh(&pch->downl);
1204 if (pch->chan) {
1205 if (pch->chan->ops->start_xmit(pch->chan, skb))
1206 ppp->xmit_pending = NULL;
1207 } else {
1208 /* channel got unregistered */
1209 kfree_skb(skb);
1210 ppp->xmit_pending = NULL;
1211 }
1212 spin_unlock_bh(&pch->downl);
1213 return;
1214 }
1215
1216 #ifdef CONFIG_PPP_MULTILINK
1217 /* Multilink: fragment the packet over as many links
1218 as can take the packet at the moment. */
1219 if (!ppp_mp_explode(ppp, skb))
1220 return;
1221 #endif /* CONFIG_PPP_MULTILINK */
1222
1223 ppp->xmit_pending = NULL;
1224 kfree_skb(skb);
1225 }
1226
1227 #ifdef CONFIG_PPP_MULTILINK
1228 /*
1229 * Divide a packet to be transmitted into fragments and
1230 * send them out the individual links.
1231 */
1232 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1233 {
1234 int len, fragsize;
1235 int i, bits, hdrlen, mtu;
1236 int flen;
1237 int navail, nfree;
1238 int nbigger;
1239 unsigned char *p, *q;
1240 struct list_head *list;
1241 struct channel *pch;
1242 struct sk_buff *frag;
1243 struct ppp_channel *chan;
1244
1245 nfree = 0; /* # channels which have no packet already queued */
1246 navail = 0; /* total # of usable channels (not deregistered) */
1247 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1248 i = 0;
1249 list_for_each_entry(pch, &ppp->channels, clist) {
1250 navail += pch->avail = (pch->chan != NULL);
1251 if (pch->avail) {
1252 if (skb_queue_empty(&pch->file.xq) ||
1253 !pch->had_frag) {
1254 pch->avail = 2;
1255 ++nfree;
1256 }
1257 if (!pch->had_frag && i < ppp->nxchan)
1258 ppp->nxchan = i;
1259 }
1260 ++i;
1261 }
1262
1263 /*
1264 * Don't start sending this packet unless at least half of
1265 * the channels are free. This gives much better TCP
1266 * performance if we have a lot of channels.
1267 */
1268 if (nfree == 0 || nfree < navail / 2)
1269 return 0; /* can't take now, leave it in xmit_pending */
1270
1271 /* Do protocol field compression (XXX this should be optional) */
1272 p = skb->data;
1273 len = skb->len;
1274 if (*p == 0) {
1275 ++p;
1276 --len;
1277 }
1278
1279 /*
1280 * Decide on fragment size.
1281 * We create a fragment for each free channel regardless of
1282 * how small they are (i.e. even 0 length) in order to minimize
1283 * the time that it will take to detect when a channel drops
1284 * a fragment.
1285 */
1286 fragsize = len;
1287 if (nfree > 1)
1288 fragsize = DIV_ROUND_UP(fragsize, nfree);
1289 /* nbigger channels get fragsize bytes, the rest get fragsize-1,
1290 except if nbigger==0, then they all get fragsize. */
1291 nbigger = len % nfree;
1292
1293 /* skip to the channel after the one we last used
1294 and start at that one */
1295 list = &ppp->channels;
1296 for (i = 0; i < ppp->nxchan; ++i) {
1297 list = list->next;
1298 if (list == &ppp->channels) {
1299 i = 0;
1300 break;
1301 }
1302 }
1303
1304 /* create a fragment for each channel */
1305 bits = B;
1306 while (nfree > 0 || len > 0) {
1307 list = list->next;
1308 if (list == &ppp->channels) {
1309 i = 0;
1310 continue;
1311 }
1312 pch = list_entry(list, struct channel, clist);
1313 ++i;
1314 if (!pch->avail)
1315 continue;
1316
1317 /*
1318 * Skip this channel if it has a fragment pending already and
1319 * we haven't given a fragment to all of the free channels.
1320 */
1321 if (pch->avail == 1) {
1322 if (nfree > 0)
1323 continue;
1324 } else {
1325 --nfree;
1326 pch->avail = 1;
1327 }
1328
1329 /* check the channel's mtu and whether it is still attached. */
1330 spin_lock_bh(&pch->downl);
1331 if (pch->chan == NULL) {
1332 /* can't use this channel, it's being deregistered */
1333 spin_unlock_bh(&pch->downl);
1334 pch->avail = 0;
1335 if (--navail == 0)
1336 break;
1337 continue;
1338 }
1339
1340 /*
1341 * Create a fragment for this channel of
1342 * min(max(mtu+2-hdrlen, 4), fragsize, len) bytes.
1343 * If mtu+2-hdrlen < 4, that is a ridiculously small
1344 * MTU, so we use mtu = 2 + hdrlen.
1345 */
1346 if (fragsize > len)
1347 fragsize = len;
1348 flen = fragsize;
1349 mtu = pch->chan->mtu + 2 - hdrlen;
1350 if (mtu < 4)
1351 mtu = 4;
1352 if (flen > mtu)
1353 flen = mtu;
1354 if (flen == len && nfree == 0)
1355 bits |= E;
1356 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1357 if (!frag)
1358 goto noskb;
1359 q = skb_put(frag, flen + hdrlen);
1360
1361 /* make the MP header */
1362 q[0] = PPP_MP >> 8;
1363 q[1] = PPP_MP;
1364 if (ppp->flags & SC_MP_XSHORTSEQ) {
1365 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1366 q[3] = ppp->nxseq;
1367 } else {
1368 q[2] = bits;
1369 q[3] = ppp->nxseq >> 16;
1370 q[4] = ppp->nxseq >> 8;
1371 q[5] = ppp->nxseq;
1372 }
1373
1374 /*
1375 * Copy the data in.
1376 * Unfortunately there is a bug in older versions of
1377 * the Linux PPP multilink reconstruction code where it
1378 * drops 0-length fragments. Therefore we make sure the
1379 * fragment has at least one byte of data. Any bytes
1380 * we add in this situation will end up as padding on the
1381 * end of the reconstructed packet.
1382 */
1383 if (flen == 0)
1384 *skb_put(frag, 1) = 0;
1385 else
1386 memcpy(q + hdrlen, p, flen);
1387
1388 /* try to send it down the channel */
1389 chan = pch->chan;
1390 if (!skb_queue_empty(&pch->file.xq) ||
1391 !chan->ops->start_xmit(chan, frag))
1392 skb_queue_tail(&pch->file.xq, frag);
1393 pch->had_frag = 1;
1394 p += flen;
1395 len -= flen;
1396 ++ppp->nxseq;
1397 bits = 0;
1398 spin_unlock_bh(&pch->downl);
1399
1400 if (--nbigger == 0 && fragsize > 0)
1401 --fragsize;
1402 }
1403 ppp->nxchan = i;
1404
1405 return 1;
1406
1407 noskb:
1408 spin_unlock_bh(&pch->downl);
1409 if (ppp->debug & 1)
1410 printk(KERN_ERR "PPP: no memory (fragment)\n");
1411 ++ppp->dev->stats.tx_errors;
1412 ++ppp->nxseq;
1413 return 1; /* abandon the frame */
1414 }
1415 #endif /* CONFIG_PPP_MULTILINK */
1416
1417 /*
1418 * Try to send data out on a channel.
1419 */
1420 static void
1421 ppp_channel_push(struct channel *pch)
1422 {
1423 struct sk_buff *skb;
1424 struct ppp *ppp;
1425
1426 spin_lock_bh(&pch->downl);
1427 if (pch->chan) {
1428 while (!skb_queue_empty(&pch->file.xq)) {
1429 skb = skb_dequeue(&pch->file.xq);
1430 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1431 /* put the packet back and try again later */
1432 skb_queue_head(&pch->file.xq, skb);
1433 break;
1434 }
1435 }
1436 } else {
1437 /* channel got deregistered */
1438 skb_queue_purge(&pch->file.xq);
1439 }
1440 spin_unlock_bh(&pch->downl);
1441 /* see if there is anything from the attached unit to be sent */
1442 if (skb_queue_empty(&pch->file.xq)) {
1443 read_lock_bh(&pch->upl);
1444 ppp = pch->ppp;
1445 if (ppp)
1446 ppp_xmit_process(ppp);
1447 read_unlock_bh(&pch->upl);
1448 }
1449 }
1450
1451 /*
1452 * Receive-side routines.
1453 */
1454
1455 /* misuse a few fields of the skb for MP reconstruction */
1456 #define sequence priority
1457 #define BEbits cb[0]
1458
1459 static inline void
1460 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1461 {
1462 ppp_recv_lock(ppp);
1463 /* ppp->dev == 0 means interface is closing down */
1464 if (ppp->dev)
1465 ppp_receive_frame(ppp, skb, pch);
1466 else
1467 kfree_skb(skb);
1468 ppp_recv_unlock(ppp);
1469 }
1470
1471 void
1472 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1473 {
1474 struct channel *pch = chan->ppp;
1475 int proto;
1476
1477 if (!pch || skb->len == 0) {
1478 kfree_skb(skb);
1479 return;
1480 }
1481
1482 proto = PPP_PROTO(skb);
1483 read_lock_bh(&pch->upl);
1484 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1485 /* put it on the channel queue */
1486 skb_queue_tail(&pch->file.rq, skb);
1487 /* drop old frames if queue too long */
1488 while (pch->file.rq.qlen > PPP_MAX_RQLEN
1489 && (skb = skb_dequeue(&pch->file.rq)))
1490 kfree_skb(skb);
1491 wake_up_interruptible(&pch->file.rwait);
1492 } else {
1493 ppp_do_recv(pch->ppp, skb, pch);
1494 }
1495 read_unlock_bh(&pch->upl);
1496 }
1497
1498 /* Put a 0-length skb in the receive queue as an error indication */
1499 void
1500 ppp_input_error(struct ppp_channel *chan, int code)
1501 {
1502 struct channel *pch = chan->ppp;
1503 struct sk_buff *skb;
1504
1505 if (!pch)
1506 return;
1507
1508 read_lock_bh(&pch->upl);
1509 if (pch->ppp) {
1510 skb = alloc_skb(0, GFP_ATOMIC);
1511 if (skb) {
1512 skb->len = 0; /* probably unnecessary */
1513 skb->cb[0] = code;
1514 ppp_do_recv(pch->ppp, skb, pch);
1515 }
1516 }
1517 read_unlock_bh(&pch->upl);
1518 }
1519
1520 /*
1521 * We come in here to process a received frame.
1522 * The receive side of the ppp unit is locked.
1523 */
1524 static void
1525 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1526 {
1527 if (pskb_may_pull(skb, 2)) {
1528 #ifdef CONFIG_PPP_MULTILINK
1529 /* XXX do channel-level decompression here */
1530 if (PPP_PROTO(skb) == PPP_MP)
1531 ppp_receive_mp_frame(ppp, skb, pch);
1532 else
1533 #endif /* CONFIG_PPP_MULTILINK */
1534 ppp_receive_nonmp_frame(ppp, skb);
1535 return;
1536 }
1537
1538 if (skb->len > 0)
1539 /* note: a 0-length skb is used as an error indication */
1540 ++ppp->dev->stats.rx_length_errors;
1541
1542 kfree_skb(skb);
1543 ppp_receive_error(ppp);
1544 }
1545
1546 static void
1547 ppp_receive_error(struct ppp *ppp)
1548 {
1549 ++ppp->dev->stats.rx_errors;
1550 if (ppp->vj)
1551 slhc_toss(ppp->vj);
1552 }
1553
1554 static void
1555 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1556 {
1557 struct sk_buff *ns;
1558 int proto, len, npi;
1559
1560 /*
1561 * Decompress the frame, if compressed.
1562 * Note that some decompressors need to see uncompressed frames
1563 * that come in as well as compressed frames.
1564 */
1565 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)
1566 && (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1567 skb = ppp_decompress_frame(ppp, skb);
1568
1569 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1570 goto err;
1571
1572 proto = PPP_PROTO(skb);
1573 switch (proto) {
1574 case PPP_VJC_COMP:
1575 /* decompress VJ compressed packets */
1576 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1577 goto err;
1578
1579 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1580 /* copy to a new sk_buff with more tailroom */
1581 ns = dev_alloc_skb(skb->len + 128);
1582 if (!ns) {
1583 printk(KERN_ERR"PPP: no memory (VJ decomp)\n");
1584 goto err;
1585 }
1586 skb_reserve(ns, 2);
1587 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1588 kfree_skb(skb);
1589 skb = ns;
1590 }
1591 else
1592 skb->ip_summed = CHECKSUM_NONE;
1593
1594 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1595 if (len <= 0) {
1596 printk(KERN_DEBUG "PPP: VJ decompression error\n");
1597 goto err;
1598 }
1599 len += 2;
1600 if (len > skb->len)
1601 skb_put(skb, len - skb->len);
1602 else if (len < skb->len)
1603 skb_trim(skb, len);
1604 proto = PPP_IP;
1605 break;
1606
1607 case PPP_VJC_UNCOMP:
1608 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1609 goto err;
1610
1611 /* Until we fix the decompressor need to make sure
1612 * data portion is linear.
1613 */
1614 if (!pskb_may_pull(skb, skb->len))
1615 goto err;
1616
1617 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1618 printk(KERN_ERR "PPP: VJ uncompressed error\n");
1619 goto err;
1620 }
1621 proto = PPP_IP;
1622 break;
1623
1624 case PPP_CCP:
1625 ppp_ccp_peek(ppp, skb, 1);
1626 break;
1627 }
1628
1629 ++ppp->dev->stats.rx_packets;
1630 ppp->dev->stats.rx_bytes += skb->len - 2;
1631
1632 npi = proto_to_npindex(proto);
1633 if (npi < 0) {
1634 /* control or unknown frame - pass it to pppd */
1635 skb_queue_tail(&ppp->file.rq, skb);
1636 /* limit queue length by dropping old frames */
1637 while (ppp->file.rq.qlen > PPP_MAX_RQLEN
1638 && (skb = skb_dequeue(&ppp->file.rq)))
1639 kfree_skb(skb);
1640 /* wake up any process polling or blocking on read */
1641 wake_up_interruptible(&ppp->file.rwait);
1642
1643 } else {
1644 /* network protocol frame - give it to the kernel */
1645
1646 #ifdef CONFIG_PPP_FILTER
1647 /* check if the packet passes the pass and active filters */
1648 /* the filter instructions are constructed assuming
1649 a four-byte PPP header on each packet */
1650 if (ppp->pass_filter || ppp->active_filter) {
1651 if (skb_cloned(skb) &&
1652 pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
1653 goto err;
1654
1655 *skb_push(skb, 2) = 0;
1656 if (ppp->pass_filter
1657 && sk_run_filter(skb, ppp->pass_filter,
1658 ppp->pass_len) == 0) {
1659 if (ppp->debug & 1)
1660 printk(KERN_DEBUG "PPP: inbound frame "
1661 "not passed\n");
1662 kfree_skb(skb);
1663 return;
1664 }
1665 if (!(ppp->active_filter
1666 && sk_run_filter(skb, ppp->active_filter,
1667 ppp->active_len) == 0))
1668 ppp->last_recv = jiffies;
1669 __skb_pull(skb, 2);
1670 } else
1671 #endif /* CONFIG_PPP_FILTER */
1672 ppp->last_recv = jiffies;
1673
1674 if ((ppp->dev->flags & IFF_UP) == 0
1675 || ppp->npmode[npi] != NPMODE_PASS) {
1676 kfree_skb(skb);
1677 } else {
1678 /* chop off protocol */
1679 skb_pull_rcsum(skb, 2);
1680 skb->dev = ppp->dev;
1681 skb->protocol = htons(npindex_to_ethertype[npi]);
1682 skb_reset_mac_header(skb);
1683 netif_rx(skb);
1684 ppp->dev->last_rx = jiffies;
1685 }
1686 }
1687 return;
1688
1689 err:
1690 kfree_skb(skb);
1691 ppp_receive_error(ppp);
1692 }
1693
1694 static struct sk_buff *
1695 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1696 {
1697 int proto = PPP_PROTO(skb);
1698 struct sk_buff *ns;
1699 int len;
1700
1701 /* Until we fix all the decompressor's need to make sure
1702 * data portion is linear.
1703 */
1704 if (!pskb_may_pull(skb, skb->len))
1705 goto err;
1706
1707 if (proto == PPP_COMP) {
1708 int obuff_size;
1709
1710 switch(ppp->rcomp->compress_proto) {
1711 case CI_MPPE:
1712 obuff_size = ppp->mru + PPP_HDRLEN + 1;
1713 break;
1714 default:
1715 obuff_size = ppp->mru + PPP_HDRLEN;
1716 break;
1717 }
1718
1719 ns = dev_alloc_skb(obuff_size);
1720 if (!ns) {
1721 printk(KERN_ERR "ppp_decompress_frame: no memory\n");
1722 goto err;
1723 }
1724 /* the decompressor still expects the A/C bytes in the hdr */
1725 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1726 skb->len + 2, ns->data, obuff_size);
1727 if (len < 0) {
1728 /* Pass the compressed frame to pppd as an
1729 error indication. */
1730 if (len == DECOMP_FATALERROR)
1731 ppp->rstate |= SC_DC_FERROR;
1732 kfree_skb(ns);
1733 goto err;
1734 }
1735
1736 kfree_skb(skb);
1737 skb = ns;
1738 skb_put(skb, len);
1739 skb_pull(skb, 2); /* pull off the A/C bytes */
1740
1741 } else {
1742 /* Uncompressed frame - pass to decompressor so it
1743 can update its dictionary if necessary. */
1744 if (ppp->rcomp->incomp)
1745 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1746 skb->len + 2);
1747 }
1748
1749 return skb;
1750
1751 err:
1752 ppp->rstate |= SC_DC_ERROR;
1753 ppp_receive_error(ppp);
1754 return skb;
1755 }
1756
1757 #ifdef CONFIG_PPP_MULTILINK
1758 /*
1759 * Receive a multilink frame.
1760 * We put it on the reconstruction queue and then pull off
1761 * as many completed frames as we can.
1762 */
1763 static void
1764 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1765 {
1766 u32 mask, seq;
1767 struct channel *ch;
1768 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1769
1770 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
1771 goto err; /* no good, throw it away */
1772
1773 /* Decode sequence number and begin/end bits */
1774 if (ppp->flags & SC_MP_SHORTSEQ) {
1775 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1776 mask = 0xfff;
1777 } else {
1778 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1779 mask = 0xffffff;
1780 }
1781 skb->BEbits = skb->data[2];
1782 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
1783
1784 /*
1785 * Do protocol ID decompression on the first fragment of each packet.
1786 */
1787 if ((skb->BEbits & B) && (skb->data[0] & 1))
1788 *skb_push(skb, 1) = 0;
1789
1790 /*
1791 * Expand sequence number to 32 bits, making it as close
1792 * as possible to ppp->minseq.
1793 */
1794 seq |= ppp->minseq & ~mask;
1795 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
1796 seq += mask + 1;
1797 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
1798 seq -= mask + 1; /* should never happen */
1799 skb->sequence = seq;
1800 pch->lastseq = seq;
1801
1802 /*
1803 * If this packet comes before the next one we were expecting,
1804 * drop it.
1805 */
1806 if (seq_before(seq, ppp->nextseq)) {
1807 kfree_skb(skb);
1808 ++ppp->dev->stats.rx_dropped;
1809 ppp_receive_error(ppp);
1810 return;
1811 }
1812
1813 /*
1814 * Reevaluate minseq, the minimum over all channels of the
1815 * last sequence number received on each channel. Because of
1816 * the increasing sequence number rule, we know that any fragment
1817 * before `minseq' which hasn't arrived is never going to arrive.
1818 * The list of channels can't change because we have the receive
1819 * side of the ppp unit locked.
1820 */
1821 list_for_each_entry(ch, &ppp->channels, clist) {
1822 if (seq_before(ch->lastseq, seq))
1823 seq = ch->lastseq;
1824 }
1825 if (seq_before(ppp->minseq, seq))
1826 ppp->minseq = seq;
1827
1828 /* Put the fragment on the reconstruction queue */
1829 ppp_mp_insert(ppp, skb);
1830
1831 /* If the queue is getting long, don't wait any longer for packets
1832 before the start of the queue. */
1833 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN
1834 && seq_before(ppp->minseq, ppp->mrq.next->sequence))
1835 ppp->minseq = ppp->mrq.next->sequence;
1836
1837 /* Pull completed packets off the queue and receive them. */
1838 while ((skb = ppp_mp_reconstruct(ppp)))
1839 ppp_receive_nonmp_frame(ppp, skb);
1840
1841 return;
1842
1843 err:
1844 kfree_skb(skb);
1845 ppp_receive_error(ppp);
1846 }
1847
1848 /*
1849 * Insert a fragment on the MP reconstruction queue.
1850 * The queue is ordered by increasing sequence number.
1851 */
1852 static void
1853 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
1854 {
1855 struct sk_buff *p;
1856 struct sk_buff_head *list = &ppp->mrq;
1857 u32 seq = skb->sequence;
1858
1859 /* N.B. we don't need to lock the list lock because we have the
1860 ppp unit receive-side lock. */
1861 for (p = list->next; p != (struct sk_buff *)list; p = p->next)
1862 if (seq_before(seq, p->sequence))
1863 break;
1864 __skb_insert(skb, p->prev, p, list);
1865 }
1866
1867 /*
1868 * Reconstruct a packet from the MP fragment queue.
1869 * We go through increasing sequence numbers until we find a
1870 * complete packet, or we get to the sequence number for a fragment
1871 * which hasn't arrived but might still do so.
1872 */
1873 static struct sk_buff *
1874 ppp_mp_reconstruct(struct ppp *ppp)
1875 {
1876 u32 seq = ppp->nextseq;
1877 u32 minseq = ppp->minseq;
1878 struct sk_buff_head *list = &ppp->mrq;
1879 struct sk_buff *p, *next;
1880 struct sk_buff *head, *tail;
1881 struct sk_buff *skb = NULL;
1882 int lost = 0, len = 0;
1883
1884 if (ppp->mrru == 0) /* do nothing until mrru is set */
1885 return NULL;
1886 head = list->next;
1887 tail = NULL;
1888 for (p = head; p != (struct sk_buff *) list; p = next) {
1889 next = p->next;
1890 if (seq_before(p->sequence, seq)) {
1891 /* this can't happen, anyway ignore the skb */
1892 printk(KERN_ERR "ppp_mp_reconstruct bad seq %u < %u\n",
1893 p->sequence, seq);
1894 head = next;
1895 continue;
1896 }
1897 if (p->sequence != seq) {
1898 /* Fragment `seq' is missing. If it is after
1899 minseq, it might arrive later, so stop here. */
1900 if (seq_after(seq, minseq))
1901 break;
1902 /* Fragment `seq' is lost, keep going. */
1903 lost = 1;
1904 seq = seq_before(minseq, p->sequence)?
1905 minseq + 1: p->sequence;
1906 next = p;
1907 continue;
1908 }
1909
1910 /*
1911 * At this point we know that all the fragments from
1912 * ppp->nextseq to seq are either present or lost.
1913 * Also, there are no complete packets in the queue
1914 * that have no missing fragments and end before this
1915 * fragment.
1916 */
1917
1918 /* B bit set indicates this fragment starts a packet */
1919 if (p->BEbits & B) {
1920 head = p;
1921 lost = 0;
1922 len = 0;
1923 }
1924
1925 len += p->len;
1926
1927 /* Got a complete packet yet? */
1928 if (lost == 0 && (p->BEbits & E) && (head->BEbits & B)) {
1929 if (len > ppp->mrru + 2) {
1930 ++ppp->dev->stats.rx_length_errors;
1931 printk(KERN_DEBUG "PPP: reconstructed packet"
1932 " is too long (%d)\n", len);
1933 } else if (p == head) {
1934 /* fragment is complete packet - reuse skb */
1935 tail = p;
1936 skb = skb_get(p);
1937 break;
1938 } else if ((skb = dev_alloc_skb(len)) == NULL) {
1939 ++ppp->dev->stats.rx_missed_errors;
1940 printk(KERN_DEBUG "PPP: no memory for "
1941 "reconstructed packet");
1942 } else {
1943 tail = p;
1944 break;
1945 }
1946 ppp->nextseq = seq + 1;
1947 }
1948
1949 /*
1950 * If this is the ending fragment of a packet,
1951 * and we haven't found a complete valid packet yet,
1952 * we can discard up to and including this fragment.
1953 */
1954 if (p->BEbits & E)
1955 head = next;
1956
1957 ++seq;
1958 }
1959
1960 /* If we have a complete packet, copy it all into one skb. */
1961 if (tail != NULL) {
1962 /* If we have discarded any fragments,
1963 signal a receive error. */
1964 if (head->sequence != ppp->nextseq) {
1965 if (ppp->debug & 1)
1966 printk(KERN_DEBUG " missed pkts %u..%u\n",
1967 ppp->nextseq, head->sequence-1);
1968 ++ppp->dev->stats.rx_dropped;
1969 ppp_receive_error(ppp);
1970 }
1971
1972 if (head != tail)
1973 /* copy to a single skb */
1974 for (p = head; p != tail->next; p = p->next)
1975 skb_copy_bits(p, 0, skb_put(skb, p->len), p->len);
1976 ppp->nextseq = tail->sequence + 1;
1977 head = tail->next;
1978 }
1979
1980 /* Discard all the skbuffs that we have copied the data out of
1981 or that we can't use. */
1982 while ((p = list->next) != head) {
1983 __skb_unlink(p, list);
1984 kfree_skb(p);
1985 }
1986
1987 return skb;
1988 }
1989 #endif /* CONFIG_PPP_MULTILINK */
1990
1991 /*
1992 * Channel interface.
1993 */
1994
1995 /*
1996 * Create a new, unattached ppp channel.
1997 */
1998 int
1999 ppp_register_channel(struct ppp_channel *chan)
2000 {
2001 struct channel *pch;
2002
2003 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2004 if (!pch)
2005 return -ENOMEM;
2006 pch->ppp = NULL;
2007 pch->chan = chan;
2008 chan->ppp = pch;
2009 init_ppp_file(&pch->file, CHANNEL);
2010 pch->file.hdrlen = chan->hdrlen;
2011 #ifdef CONFIG_PPP_MULTILINK
2012 pch->lastseq = -1;
2013 #endif /* CONFIG_PPP_MULTILINK */
2014 init_rwsem(&pch->chan_sem);
2015 spin_lock_init(&pch->downl);
2016 rwlock_init(&pch->upl);
2017 spin_lock_bh(&all_channels_lock);
2018 pch->file.index = ++last_channel_index;
2019 list_add(&pch->list, &new_channels);
2020 atomic_inc(&channel_count);
2021 spin_unlock_bh(&all_channels_lock);
2022 return 0;
2023 }
2024
2025 /*
2026 * Return the index of a channel.
2027 */
2028 int ppp_channel_index(struct ppp_channel *chan)
2029 {
2030 struct channel *pch = chan->ppp;
2031
2032 if (pch)
2033 return pch->file.index;
2034 return -1;
2035 }
2036
2037 /*
2038 * Return the PPP unit number to which a channel is connected.
2039 */
2040 int ppp_unit_number(struct ppp_channel *chan)
2041 {
2042 struct channel *pch = chan->ppp;
2043 int unit = -1;
2044
2045 if (pch) {
2046 read_lock_bh(&pch->upl);
2047 if (pch->ppp)
2048 unit = pch->ppp->file.index;
2049 read_unlock_bh(&pch->upl);
2050 }
2051 return unit;
2052 }
2053
2054 /*
2055 * Disconnect a channel from the generic layer.
2056 * This must be called in process context.
2057 */
2058 void
2059 ppp_unregister_channel(struct ppp_channel *chan)
2060 {
2061 struct channel *pch = chan->ppp;
2062
2063 if (!pch)
2064 return; /* should never happen */
2065 chan->ppp = NULL;
2066
2067 /*
2068 * This ensures that we have returned from any calls into the
2069 * the channel's start_xmit or ioctl routine before we proceed.
2070 */
2071 down_write(&pch->chan_sem);
2072 spin_lock_bh(&pch->downl);
2073 pch->chan = NULL;
2074 spin_unlock_bh(&pch->downl);
2075 up_write(&pch->chan_sem);
2076 ppp_disconnect_channel(pch);
2077 spin_lock_bh(&all_channels_lock);
2078 list_del(&pch->list);
2079 spin_unlock_bh(&all_channels_lock);
2080 pch->file.dead = 1;
2081 wake_up_interruptible(&pch->file.rwait);
2082 if (atomic_dec_and_test(&pch->file.refcnt))
2083 ppp_destroy_channel(pch);
2084 }
2085
2086 /*
2087 * Callback from a channel when it can accept more to transmit.
2088 * This should be called at BH/softirq level, not interrupt level.
2089 */
2090 void
2091 ppp_output_wakeup(struct ppp_channel *chan)
2092 {
2093 struct channel *pch = chan->ppp;
2094
2095 if (!pch)
2096 return;
2097 ppp_channel_push(pch);
2098 }
2099
2100 /*
2101 * Compression control.
2102 */
2103
2104 /* Process the PPPIOCSCOMPRESS ioctl. */
2105 static int
2106 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2107 {
2108 int err;
2109 struct compressor *cp, *ocomp;
2110 struct ppp_option_data data;
2111 void *state, *ostate;
2112 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2113
2114 err = -EFAULT;
2115 if (copy_from_user(&data, (void __user *) arg, sizeof(data))
2116 || (data.length <= CCP_MAX_OPTION_LENGTH
2117 && copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2118 goto out;
2119 err = -EINVAL;
2120 if (data.length > CCP_MAX_OPTION_LENGTH
2121 || ccp_option[1] < 2 || ccp_option[1] > data.length)
2122 goto out;
2123
2124 cp = find_compressor(ccp_option[0]);
2125 #ifdef CONFIG_KMOD
2126 if (!cp) {
2127 request_module("ppp-compress-%d", ccp_option[0]);
2128 cp = find_compressor(ccp_option[0]);
2129 }
2130 #endif /* CONFIG_KMOD */
2131 if (!cp)
2132 goto out;
2133
2134 err = -ENOBUFS;
2135 if (data.transmit) {
2136 state = cp->comp_alloc(ccp_option, data.length);
2137 if (state) {
2138 ppp_xmit_lock(ppp);
2139 ppp->xstate &= ~SC_COMP_RUN;
2140 ocomp = ppp->xcomp;
2141 ostate = ppp->xc_state;
2142 ppp->xcomp = cp;
2143 ppp->xc_state = state;
2144 ppp_xmit_unlock(ppp);
2145 if (ostate) {
2146 ocomp->comp_free(ostate);
2147 module_put(ocomp->owner);
2148 }
2149 err = 0;
2150 } else
2151 module_put(cp->owner);
2152
2153 } else {
2154 state = cp->decomp_alloc(ccp_option, data.length);
2155 if (state) {
2156 ppp_recv_lock(ppp);
2157 ppp->rstate &= ~SC_DECOMP_RUN;
2158 ocomp = ppp->rcomp;
2159 ostate = ppp->rc_state;
2160 ppp->rcomp = cp;
2161 ppp->rc_state = state;
2162 ppp_recv_unlock(ppp);
2163 if (ostate) {
2164 ocomp->decomp_free(ostate);
2165 module_put(ocomp->owner);
2166 }
2167 err = 0;
2168 } else
2169 module_put(cp->owner);
2170 }
2171
2172 out:
2173 return err;
2174 }
2175
2176 /*
2177 * Look at a CCP packet and update our state accordingly.
2178 * We assume the caller has the xmit or recv path locked.
2179 */
2180 static void
2181 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2182 {
2183 unsigned char *dp;
2184 int len;
2185
2186 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2187 return; /* no header */
2188 dp = skb->data + 2;
2189
2190 switch (CCP_CODE(dp)) {
2191 case CCP_CONFREQ:
2192
2193 /* A ConfReq starts negotiation of compression
2194 * in one direction of transmission,
2195 * and hence brings it down...but which way?
2196 *
2197 * Remember:
2198 * A ConfReq indicates what the sender would like to receive
2199 */
2200 if(inbound)
2201 /* He is proposing what I should send */
2202 ppp->xstate &= ~SC_COMP_RUN;
2203 else
2204 /* I am proposing to what he should send */
2205 ppp->rstate &= ~SC_DECOMP_RUN;
2206
2207 break;
2208
2209 case CCP_TERMREQ:
2210 case CCP_TERMACK:
2211 /*
2212 * CCP is going down, both directions of transmission
2213 */
2214 ppp->rstate &= ~SC_DECOMP_RUN;
2215 ppp->xstate &= ~SC_COMP_RUN;
2216 break;
2217
2218 case CCP_CONFACK:
2219 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2220 break;
2221 len = CCP_LENGTH(dp);
2222 if (!pskb_may_pull(skb, len + 2))
2223 return; /* too short */
2224 dp += CCP_HDRLEN;
2225 len -= CCP_HDRLEN;
2226 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2227 break;
2228 if (inbound) {
2229 /* we will start receiving compressed packets */
2230 if (!ppp->rc_state)
2231 break;
2232 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2233 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2234 ppp->rstate |= SC_DECOMP_RUN;
2235 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2236 }
2237 } else {
2238 /* we will soon start sending compressed packets */
2239 if (!ppp->xc_state)
2240 break;
2241 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2242 ppp->file.index, 0, ppp->debug))
2243 ppp->xstate |= SC_COMP_RUN;
2244 }
2245 break;
2246
2247 case CCP_RESETACK:
2248 /* reset the [de]compressor */
2249 if ((ppp->flags & SC_CCP_UP) == 0)
2250 break;
2251 if (inbound) {
2252 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2253 ppp->rcomp->decomp_reset(ppp->rc_state);
2254 ppp->rstate &= ~SC_DC_ERROR;
2255 }
2256 } else {
2257 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2258 ppp->xcomp->comp_reset(ppp->xc_state);
2259 }
2260 break;
2261 }
2262 }
2263
2264 /* Free up compression resources. */
2265 static void
2266 ppp_ccp_closed(struct ppp *ppp)
2267 {
2268 void *xstate, *rstate;
2269 struct compressor *xcomp, *rcomp;
2270
2271 ppp_lock(ppp);
2272 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2273 ppp->xstate = 0;
2274 xcomp = ppp->xcomp;
2275 xstate = ppp->xc_state;
2276 ppp->xc_state = NULL;
2277 ppp->rstate = 0;
2278 rcomp = ppp->rcomp;
2279 rstate = ppp->rc_state;
2280 ppp->rc_state = NULL;
2281 ppp_unlock(ppp);
2282
2283 if (xstate) {
2284 xcomp->comp_free(xstate);
2285 module_put(xcomp->owner);
2286 }
2287 if (rstate) {
2288 rcomp->decomp_free(rstate);
2289 module_put(rcomp->owner);
2290 }
2291 }
2292
2293 /* List of compressors. */
2294 static LIST_HEAD(compressor_list);
2295 static DEFINE_SPINLOCK(compressor_list_lock);
2296
2297 struct compressor_entry {
2298 struct list_head list;
2299 struct compressor *comp;
2300 };
2301
2302 static struct compressor_entry *
2303 find_comp_entry(int proto)
2304 {
2305 struct compressor_entry *ce;
2306
2307 list_for_each_entry(ce, &compressor_list, list) {
2308 if (ce->comp->compress_proto == proto)
2309 return ce;
2310 }
2311 return NULL;
2312 }
2313
2314 /* Register a compressor */
2315 int
2316 ppp_register_compressor(struct compressor *cp)
2317 {
2318 struct compressor_entry *ce;
2319 int ret;
2320 spin_lock(&compressor_list_lock);
2321 ret = -EEXIST;
2322 if (find_comp_entry(cp->compress_proto))
2323 goto out;
2324 ret = -ENOMEM;
2325 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2326 if (!ce)
2327 goto out;
2328 ret = 0;
2329 ce->comp = cp;
2330 list_add(&ce->list, &compressor_list);
2331 out:
2332 spin_unlock(&compressor_list_lock);
2333 return ret;
2334 }
2335
2336 /* Unregister a compressor */
2337 void
2338 ppp_unregister_compressor(struct compressor *cp)
2339 {
2340 struct compressor_entry *ce;
2341
2342 spin_lock(&compressor_list_lock);
2343 ce = find_comp_entry(cp->compress_proto);
2344 if (ce && ce->comp == cp) {
2345 list_del(&ce->list);
2346 kfree(ce);
2347 }
2348 spin_unlock(&compressor_list_lock);
2349 }
2350
2351 /* Find a compressor. */
2352 static struct compressor *
2353 find_compressor(int type)
2354 {
2355 struct compressor_entry *ce;
2356 struct compressor *cp = NULL;
2357
2358 spin_lock(&compressor_list_lock);
2359 ce = find_comp_entry(type);
2360 if (ce) {
2361 cp = ce->comp;
2362 if (!try_module_get(cp->owner))
2363 cp = NULL;
2364 }
2365 spin_unlock(&compressor_list_lock);
2366 return cp;
2367 }
2368
2369 /*
2370 * Miscelleneous stuff.
2371 */
2372
2373 static void
2374 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2375 {
2376 struct slcompress *vj = ppp->vj;
2377
2378 memset(st, 0, sizeof(*st));
2379 st->p.ppp_ipackets = ppp->dev->stats.rx_packets;
2380 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2381 st->p.ppp_ibytes = ppp->dev->stats.rx_bytes;
2382 st->p.ppp_opackets = ppp->dev->stats.tx_packets;
2383 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2384 st->p.ppp_obytes = ppp->dev->stats.tx_bytes;
2385 if (!vj)
2386 return;
2387 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2388 st->vj.vjs_compressed = vj->sls_o_compressed;
2389 st->vj.vjs_searches = vj->sls_o_searches;
2390 st->vj.vjs_misses = vj->sls_o_misses;
2391 st->vj.vjs_errorin = vj->sls_i_error;
2392 st->vj.vjs_tossed = vj->sls_i_tossed;
2393 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2394 st->vj.vjs_compressedin = vj->sls_i_compressed;
2395 }
2396
2397 /*
2398 * Stuff for handling the lists of ppp units and channels
2399 * and for initialization.
2400 */
2401
2402 /*
2403 * Create a new ppp interface unit. Fails if it can't allocate memory
2404 * or if there is already a unit with the requested number.
2405 * unit == -1 means allocate a new number.
2406 */
2407 static struct ppp *
2408 ppp_create_interface(int unit, int *retp)
2409 {
2410 struct ppp *ppp;
2411 struct net_device *dev = NULL;
2412 int ret = -ENOMEM;
2413 int i;
2414
2415 ppp = kzalloc(sizeof(struct ppp), GFP_KERNEL);
2416 if (!ppp)
2417 goto out;
2418 dev = alloc_netdev(0, "", ppp_setup);
2419 if (!dev)
2420 goto out1;
2421
2422 ppp->mru = PPP_MRU;
2423 init_ppp_file(&ppp->file, INTERFACE);
2424 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2425 for (i = 0; i < NUM_NP; ++i)
2426 ppp->npmode[i] = NPMODE_PASS;
2427 INIT_LIST_HEAD(&ppp->channels);
2428 spin_lock_init(&ppp->rlock);
2429 spin_lock_init(&ppp->wlock);
2430 #ifdef CONFIG_PPP_MULTILINK
2431 ppp->minseq = -1;
2432 skb_queue_head_init(&ppp->mrq);
2433 #endif /* CONFIG_PPP_MULTILINK */
2434 ppp->dev = dev;
2435 dev->priv = ppp;
2436
2437 dev->hard_start_xmit = ppp_start_xmit;
2438 dev->do_ioctl = ppp_net_ioctl;
2439
2440 ret = -EEXIST;
2441 mutex_lock(&all_ppp_mutex);
2442 if (unit < 0)
2443 unit = cardmap_find_first_free(all_ppp_units);
2444 else if (cardmap_get(all_ppp_units, unit) != NULL)
2445 goto out2; /* unit already exists */
2446
2447 /* Initialize the new ppp unit */
2448 ppp->file.index = unit;
2449 sprintf(dev->name, "ppp%d", unit);
2450
2451 ret = register_netdev(dev);
2452 if (ret != 0) {
2453 printk(KERN_ERR "PPP: couldn't register device %s (%d)\n",
2454 dev->name, ret);
2455 goto out2;
2456 }
2457
2458 atomic_inc(&ppp_unit_count);
2459 ret = cardmap_set(&all_ppp_units, unit, ppp);
2460 if (ret != 0)
2461 goto out3;
2462
2463 mutex_unlock(&all_ppp_mutex);
2464 *retp = 0;
2465 return ppp;
2466
2467 out3:
2468 atomic_dec(&ppp_unit_count);
2469 unregister_netdev(dev);
2470 out2:
2471 mutex_unlock(&all_ppp_mutex);
2472 free_netdev(dev);
2473 out1:
2474 kfree(ppp);
2475 out:
2476 *retp = ret;
2477 return NULL;
2478 }
2479
2480 /*
2481 * Initialize a ppp_file structure.
2482 */
2483 static void
2484 init_ppp_file(struct ppp_file *pf, int kind)
2485 {
2486 pf->kind = kind;
2487 skb_queue_head_init(&pf->xq);
2488 skb_queue_head_init(&pf->rq);
2489 atomic_set(&pf->refcnt, 1);
2490 init_waitqueue_head(&pf->rwait);
2491 }
2492
2493 /*
2494 * Take down a ppp interface unit - called when the owning file
2495 * (the one that created the unit) is closed or detached.
2496 */
2497 static void ppp_shutdown_interface(struct ppp *ppp)
2498 {
2499 struct net_device *dev;
2500
2501 mutex_lock(&all_ppp_mutex);
2502 ppp_lock(ppp);
2503 dev = ppp->dev;
2504 ppp->dev = NULL;
2505 ppp_unlock(ppp);
2506 /* This will call dev_close() for us. */
2507 if (dev) {
2508 unregister_netdev(dev);
2509 free_netdev(dev);
2510 }
2511 cardmap_set(&all_ppp_units, ppp->file.index, NULL);
2512 ppp->file.dead = 1;
2513 ppp->owner = NULL;
2514 wake_up_interruptible(&ppp->file.rwait);
2515 mutex_unlock(&all_ppp_mutex);
2516 }
2517
2518 /*
2519 * Free the memory used by a ppp unit. This is only called once
2520 * there are no channels connected to the unit and no file structs
2521 * that reference the unit.
2522 */
2523 static void ppp_destroy_interface(struct ppp *ppp)
2524 {
2525 atomic_dec(&ppp_unit_count);
2526
2527 if (!ppp->file.dead || ppp->n_channels) {
2528 /* "can't happen" */
2529 printk(KERN_ERR "ppp: destroying ppp struct %p but dead=%d "
2530 "n_channels=%d !\n", ppp, ppp->file.dead,
2531 ppp->n_channels);
2532 return;
2533 }
2534
2535 ppp_ccp_closed(ppp);
2536 if (ppp->vj) {
2537 slhc_free(ppp->vj);
2538 ppp->vj = NULL;
2539 }
2540 skb_queue_purge(&ppp->file.xq);
2541 skb_queue_purge(&ppp->file.rq);
2542 #ifdef CONFIG_PPP_MULTILINK
2543 skb_queue_purge(&ppp->mrq);
2544 #endif /* CONFIG_PPP_MULTILINK */
2545 #ifdef CONFIG_PPP_FILTER
2546 kfree(ppp->pass_filter);
2547 ppp->pass_filter = NULL;
2548 kfree(ppp->active_filter);
2549 ppp->active_filter = NULL;
2550 #endif /* CONFIG_PPP_FILTER */
2551
2552 if (ppp->xmit_pending)
2553 kfree_skb(ppp->xmit_pending);
2554
2555 kfree(ppp);
2556 }
2557
2558 /*
2559 * Locate an existing ppp unit.
2560 * The caller should have locked the all_ppp_mutex.
2561 */
2562 static struct ppp *
2563 ppp_find_unit(int unit)
2564 {
2565 return cardmap_get(all_ppp_units, unit);
2566 }
2567
2568 /*
2569 * Locate an existing ppp channel.
2570 * The caller should have locked the all_channels_lock.
2571 * First we look in the new_channels list, then in the
2572 * all_channels list. If found in the new_channels list,
2573 * we move it to the all_channels list. This is for speed
2574 * when we have a lot of channels in use.
2575 */
2576 static struct channel *
2577 ppp_find_channel(int unit)
2578 {
2579 struct channel *pch;
2580
2581 list_for_each_entry(pch, &new_channels, list) {
2582 if (pch->file.index == unit) {
2583 list_move(&pch->list, &all_channels);
2584 return pch;
2585 }
2586 }
2587 list_for_each_entry(pch, &all_channels, list) {
2588 if (pch->file.index == unit)
2589 return pch;
2590 }
2591 return NULL;
2592 }
2593
2594 /*
2595 * Connect a PPP channel to a PPP interface unit.
2596 */
2597 static int
2598 ppp_connect_channel(struct channel *pch, int unit)
2599 {
2600 struct ppp *ppp;
2601 int ret = -ENXIO;
2602 int hdrlen;
2603
2604 mutex_lock(&all_ppp_mutex);
2605 ppp = ppp_find_unit(unit);
2606 if (!ppp)
2607 goto out;
2608 write_lock_bh(&pch->upl);
2609 ret = -EINVAL;
2610 if (pch->ppp)
2611 goto outl;
2612
2613 ppp_lock(ppp);
2614 if (pch->file.hdrlen > ppp->file.hdrlen)
2615 ppp->file.hdrlen = pch->file.hdrlen;
2616 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2617 if (ppp->dev && hdrlen > ppp->dev->hard_header_len)
2618 ppp->dev->hard_header_len = hdrlen;
2619 list_add_tail(&pch->clist, &ppp->channels);
2620 ++ppp->n_channels;
2621 pch->ppp = ppp;
2622 atomic_inc(&ppp->file.refcnt);
2623 ppp_unlock(ppp);
2624 ret = 0;
2625
2626 outl:
2627 write_unlock_bh(&pch->upl);
2628 out:
2629 mutex_unlock(&all_ppp_mutex);
2630 return ret;
2631 }
2632
2633 /*
2634 * Disconnect a channel from its ppp unit.
2635 */
2636 static int
2637 ppp_disconnect_channel(struct channel *pch)
2638 {
2639 struct ppp *ppp;
2640 int err = -EINVAL;
2641
2642 write_lock_bh(&pch->upl);
2643 ppp = pch->ppp;
2644 pch->ppp = NULL;
2645 write_unlock_bh(&pch->upl);
2646 if (ppp) {
2647 /* remove it from the ppp unit's list */
2648 ppp_lock(ppp);
2649 list_del(&pch->clist);
2650 if (--ppp->n_channels == 0)
2651 wake_up_interruptible(&ppp->file.rwait);
2652 ppp_unlock(ppp);
2653 if (atomic_dec_and_test(&ppp->file.refcnt))
2654 ppp_destroy_interface(ppp);
2655 err = 0;
2656 }
2657 return err;
2658 }
2659
2660 /*
2661 * Free up the resources used by a ppp channel.
2662 */
2663 static void ppp_destroy_channel(struct channel *pch)
2664 {
2665 atomic_dec(&channel_count);
2666
2667 if (!pch->file.dead) {
2668 /* "can't happen" */
2669 printk(KERN_ERR "ppp: destroying undead channel %p !\n",
2670 pch);
2671 return;
2672 }
2673 skb_queue_purge(&pch->file.xq);
2674 skb_queue_purge(&pch->file.rq);
2675 kfree(pch);
2676 }
2677
2678 static void __exit ppp_cleanup(void)
2679 {
2680 /* should never happen */
2681 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2682 printk(KERN_ERR "PPP: removing module but units remain!\n");
2683 cardmap_destroy(&all_ppp_units);
2684 unregister_chrdev(PPP_MAJOR, "ppp");
2685 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
2686 class_destroy(ppp_class);
2687 }
2688
2689 /*
2690 * Cardmap implementation.
2691 */
2692 static void *cardmap_get(struct cardmap *map, unsigned int nr)
2693 {
2694 struct cardmap *p;
2695 int i;
2696
2697 for (p = map; p != NULL; ) {
2698 if ((i = nr >> p->shift) >= CARDMAP_WIDTH)
2699 return NULL;
2700 if (p->shift == 0)
2701 return p->ptr[i];
2702 nr &= ~(CARDMAP_MASK << p->shift);
2703 p = p->ptr[i];
2704 }
2705 return NULL;
2706 }
2707
2708 static int cardmap_set(struct cardmap **pmap, unsigned int nr, void *ptr)
2709 {
2710 struct cardmap *p;
2711 int i;
2712
2713 p = *pmap;
2714 if (p == NULL || (nr >> p->shift) >= CARDMAP_WIDTH) {
2715 do {
2716 /* need a new top level */
2717 struct cardmap *np = kzalloc(sizeof(*np), GFP_KERNEL);
2718 if (!np)
2719 goto enomem;
2720 np->ptr[0] = p;
2721 if (p != NULL) {
2722 np->shift = p->shift + CARDMAP_ORDER;
2723 p->parent = np;
2724 } else
2725 np->shift = 0;
2726 p = np;
2727 } while ((nr >> p->shift) >= CARDMAP_WIDTH);
2728 *pmap = p;
2729 }
2730 while (p->shift > 0) {
2731 i = (nr >> p->shift) & CARDMAP_MASK;
2732 if (p->ptr[i] == NULL) {
2733 struct cardmap *np = kzalloc(sizeof(*np), GFP_KERNEL);
2734 if (!np)
2735 goto enomem;
2736 np->shift = p->shift - CARDMAP_ORDER;
2737 np->parent = p;
2738 p->ptr[i] = np;
2739 }
2740 if (ptr == NULL)
2741 clear_bit(i, &p->inuse);
2742 p = p->ptr[i];
2743 }
2744 i = nr & CARDMAP_MASK;
2745 p->ptr[i] = ptr;
2746 if (ptr != NULL)
2747 set_bit(i, &p->inuse);
2748 else
2749 clear_bit(i, &p->inuse);
2750 return 0;
2751 enomem:
2752 return -ENOMEM;
2753 }
2754
2755 static unsigned int cardmap_find_first_free(struct cardmap *map)
2756 {
2757 struct cardmap *p;
2758 unsigned int nr = 0;
2759 int i;
2760
2761 if ((p = map) == NULL)
2762 return 0;
2763 for (;;) {
2764 i = find_first_zero_bit(&p->inuse, CARDMAP_WIDTH);
2765 if (i >= CARDMAP_WIDTH) {
2766 if (p->parent == NULL)
2767 return CARDMAP_WIDTH << p->shift;
2768 p = p->parent;
2769 i = (nr >> p->shift) & CARDMAP_MASK;
2770 set_bit(i, &p->inuse);
2771 continue;
2772 }
2773 nr = (nr & (~CARDMAP_MASK << p->shift)) | (i << p->shift);
2774 if (p->shift == 0 || p->ptr[i] == NULL)
2775 return nr;
2776 p = p->ptr[i];
2777 }
2778 }
2779
2780 static void cardmap_destroy(struct cardmap **pmap)
2781 {
2782 struct cardmap *p, *np;
2783 int i;
2784
2785 for (p = *pmap; p != NULL; p = np) {
2786 if (p->shift != 0) {
2787 for (i = 0; i < CARDMAP_WIDTH; ++i)
2788 if (p->ptr[i] != NULL)
2789 break;
2790 if (i < CARDMAP_WIDTH) {
2791 np = p->ptr[i];
2792 p->ptr[i] = NULL;
2793 continue;
2794 }
2795 }
2796 np = p->parent;
2797 kfree(p);
2798 }
2799 *pmap = NULL;
2800 }
2801
2802 /* Module/initialization stuff */
2803
2804 module_init(ppp_init);
2805 module_exit(ppp_cleanup);
2806
2807 EXPORT_SYMBOL(ppp_register_channel);
2808 EXPORT_SYMBOL(ppp_unregister_channel);
2809 EXPORT_SYMBOL(ppp_channel_index);
2810 EXPORT_SYMBOL(ppp_unit_number);
2811 EXPORT_SYMBOL(ppp_input);
2812 EXPORT_SYMBOL(ppp_input_error);
2813 EXPORT_SYMBOL(ppp_output_wakeup);
2814 EXPORT_SYMBOL(ppp_register_compressor);
2815 EXPORT_SYMBOL(ppp_unregister_compressor);
2816 MODULE_LICENSE("GPL");
2817 MODULE_ALIAS_CHARDEV_MAJOR(PPP_MAJOR);
2818 MODULE_ALIAS("/dev/ppp");
CJK support for tty framebuffer vt