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Merge branch 'drm-patches' of master.kernel.org:/pub/scm/linux/kernel/git/airlied...
[mirror_ubuntu-bionic-kernel.git] / drivers / net / ppp_generic.c
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/smp_lock.h>
44 #include <linux/rwsem.h>
45 #include <linux/stddef.h>
46 #include <linux/device.h>
47 #include <linux/mutex.h>
48 #include <net/slhc_vj.h>
49 #include <asm/atomic.h>
50
51 #define PPP_VERSION "2.4.2"
52
53 /*
54 * Network protocols we support.
55 */
56 #define NP_IP 0 /* Internet Protocol V4 */
57 #define NP_IPV6 1 /* Internet Protocol V6 */
58 #define NP_IPX 2 /* IPX protocol */
59 #define NP_AT 3 /* Appletalk protocol */
60 #define NP_MPLS_UC 4 /* MPLS unicast */
61 #define NP_MPLS_MC 5 /* MPLS multicast */
62 #define NUM_NP 6 /* Number of NPs. */
63
64 #define MPHDRLEN 6 /* multilink protocol header length */
65 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */
66 #define MIN_FRAG_SIZE 64
67
68 /*
69 * An instance of /dev/ppp can be associated with either a ppp
70 * interface unit or a ppp channel. In both cases, file->private_data
71 * points to one of these.
72 */
73 struct ppp_file {
74 enum {
75 INTERFACE=1, CHANNEL
76 } kind;
77 struct sk_buff_head xq; /* pppd transmit queue */
78 struct sk_buff_head rq; /* receive queue for pppd */
79 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */
80 atomic_t refcnt; /* # refs (incl /dev/ppp attached) */
81 int hdrlen; /* space to leave for headers */
82 int index; /* interface unit / channel number */
83 int dead; /* unit/channel has been shut down */
84 };
85
86 #define PF_TO_X(pf, X) container_of(pf, X, file)
87
88 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
89 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
90
91 /*
92 * Data structure describing one ppp unit.
93 * A ppp unit corresponds to a ppp network interface device
94 * and represents a multilink bundle.
95 * It can have 0 or more ppp channels connected to it.
96 */
97 struct ppp {
98 struct ppp_file file; /* stuff for read/write/poll 0 */
99 struct file *owner; /* file that owns this unit 48 */
100 struct list_head channels; /* list of attached channels 4c */
101 int n_channels; /* how many channels are attached 54 */
102 spinlock_t rlock; /* lock for receive side 58 */
103 spinlock_t wlock; /* lock for transmit side 5c */
104 int mru; /* max receive unit 60 */
105 unsigned int flags; /* control bits 64 */
106 unsigned int xstate; /* transmit state bits 68 */
107 unsigned int rstate; /* receive state bits 6c */
108 int debug; /* debug flags 70 */
109 struct slcompress *vj; /* state for VJ header compression */
110 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
111 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
112 struct compressor *xcomp; /* transmit packet compressor 8c */
113 void *xc_state; /* its internal state 90 */
114 struct compressor *rcomp; /* receive decompressor 94 */
115 void *rc_state; /* its internal state 98 */
116 unsigned long last_xmit; /* jiffies when last pkt sent 9c */
117 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
118 struct net_device *dev; /* network interface device a4 */
119 #ifdef CONFIG_PPP_MULTILINK
120 int nxchan; /* next channel to send something on */
121 u32 nxseq; /* next sequence number to send */
122 int mrru; /* MP: max reconst. receive unit */
123 u32 nextseq; /* MP: seq no of next packet */
124 u32 minseq; /* MP: min of most recent seqnos */
125 struct sk_buff_head mrq; /* MP: receive reconstruction queue */
126 #endif /* CONFIG_PPP_MULTILINK */
127 struct net_device_stats stats; /* statistics */
128 #ifdef CONFIG_PPP_FILTER
129 struct sock_filter *pass_filter; /* filter for packets to pass */
130 struct sock_filter *active_filter;/* filter for pkts to reset idle */
131 unsigned pass_len, active_len;
132 #endif /* CONFIG_PPP_FILTER */
133 };
134
135 /*
136 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
137 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
138 * SC_MUST_COMP
139 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
140 * Bits in xstate: SC_COMP_RUN
141 */
142 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
143 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
144 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
145
146 /*
147 * Private data structure for each channel.
148 * This includes the data structure used for multilink.
149 */
150 struct channel {
151 struct ppp_file file; /* stuff for read/write/poll */
152 struct list_head list; /* link in all/new_channels list */
153 struct ppp_channel *chan; /* public channel data structure */
154 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
155 spinlock_t downl; /* protects `chan', file.xq dequeue */
156 struct ppp *ppp; /* ppp unit we're connected to */
157 struct list_head clist; /* link in list of channels per unit */
158 rwlock_t upl; /* protects `ppp' */
159 #ifdef CONFIG_PPP_MULTILINK
160 u8 avail; /* flag used in multilink stuff */
161 u8 had_frag; /* >= 1 fragments have been sent */
162 u32 lastseq; /* MP: last sequence # received */
163 #endif /* CONFIG_PPP_MULTILINK */
164 };
165
166 /*
167 * SMP locking issues:
168 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
169 * list and the ppp.n_channels field, you need to take both locks
170 * before you modify them.
171 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
172 * channel.downl.
173 */
174
175 /*
176 * A cardmap represents a mapping from unsigned integers to pointers,
177 * and provides a fast "find lowest unused number" operation.
178 * It uses a broad (32-way) tree with a bitmap at each level.
179 * It is designed to be space-efficient for small numbers of entries
180 * and time-efficient for large numbers of entries.
181 */
182 #define CARDMAP_ORDER 5
183 #define CARDMAP_WIDTH (1U << CARDMAP_ORDER)
184 #define CARDMAP_MASK (CARDMAP_WIDTH - 1)
185
186 struct cardmap {
187 int shift;
188 unsigned long inuse;
189 struct cardmap *parent;
190 void *ptr[CARDMAP_WIDTH];
191 };
192 static void *cardmap_get(struct cardmap *map, unsigned int nr);
193 static int cardmap_set(struct cardmap **map, unsigned int nr, void *ptr);
194 static unsigned int cardmap_find_first_free(struct cardmap *map);
195 static void cardmap_destroy(struct cardmap **map);
196
197 /*
198 * all_ppp_mutex protects the all_ppp_units mapping.
199 * It also ensures that finding a ppp unit in the all_ppp_units map
200 * and updating its file.refcnt field is atomic.
201 */
202 static DEFINE_MUTEX(all_ppp_mutex);
203 static struct cardmap *all_ppp_units;
204 static atomic_t ppp_unit_count = ATOMIC_INIT(0);
205
206 /*
207 * all_channels_lock protects all_channels and last_channel_index,
208 * and the atomicity of find a channel and updating its file.refcnt
209 * field.
210 */
211 static DEFINE_SPINLOCK(all_channels_lock);
212 static LIST_HEAD(all_channels);
213 static LIST_HEAD(new_channels);
214 static int last_channel_index;
215 static atomic_t channel_count = ATOMIC_INIT(0);
216
217 /* Get the PPP protocol number from a skb */
218 #define PPP_PROTO(skb) (((skb)->data[0] << 8) + (skb)->data[1])
219
220 /* We limit the length of ppp->file.rq to this (arbitrary) value */
221 #define PPP_MAX_RQLEN 32
222
223 /*
224 * Maximum number of multilink fragments queued up.
225 * This has to be large enough to cope with the maximum latency of
226 * the slowest channel relative to the others. Strictly it should
227 * depend on the number of channels and their characteristics.
228 */
229 #define PPP_MP_MAX_QLEN 128
230
231 /* Multilink header bits. */
232 #define B 0x80 /* this fragment begins a packet */
233 #define E 0x40 /* this fragment ends a packet */
234
235 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */
236 #define seq_before(a, b) ((s32)((a) - (b)) < 0)
237 #define seq_after(a, b) ((s32)((a) - (b)) > 0)
238
239 /* Prototypes. */
240 static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file,
241 unsigned int cmd, unsigned long arg);
242 static void ppp_xmit_process(struct ppp *ppp);
243 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
244 static void ppp_push(struct ppp *ppp);
245 static void ppp_channel_push(struct channel *pch);
246 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
247 struct channel *pch);
248 static void ppp_receive_error(struct ppp *ppp);
249 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
250 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
251 struct sk_buff *skb);
252 #ifdef CONFIG_PPP_MULTILINK
253 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
254 struct channel *pch);
255 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
256 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
257 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
258 #endif /* CONFIG_PPP_MULTILINK */
259 static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
260 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
261 static void ppp_ccp_closed(struct ppp *ppp);
262 static struct compressor *find_compressor(int type);
263 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
264 static struct ppp *ppp_create_interface(int unit, int *retp);
265 static void init_ppp_file(struct ppp_file *pf, int kind);
266 static void ppp_shutdown_interface(struct ppp *ppp);
267 static void ppp_destroy_interface(struct ppp *ppp);
268 static struct ppp *ppp_find_unit(int unit);
269 static struct channel *ppp_find_channel(int unit);
270 static int ppp_connect_channel(struct channel *pch, int unit);
271 static int ppp_disconnect_channel(struct channel *pch);
272 static void ppp_destroy_channel(struct channel *pch);
273
274 static struct class *ppp_class;
275
276 /* Translates a PPP protocol number to a NP index (NP == network protocol) */
277 static inline int proto_to_npindex(int proto)
278 {
279 switch (proto) {
280 case PPP_IP:
281 return NP_IP;
282 case PPP_IPV6:
283 return NP_IPV6;
284 case PPP_IPX:
285 return NP_IPX;
286 case PPP_AT:
287 return NP_AT;
288 case PPP_MPLS_UC:
289 return NP_MPLS_UC;
290 case PPP_MPLS_MC:
291 return NP_MPLS_MC;
292 }
293 return -EINVAL;
294 }
295
296 /* Translates an NP index into a PPP protocol number */
297 static const int npindex_to_proto[NUM_NP] = {
298 PPP_IP,
299 PPP_IPV6,
300 PPP_IPX,
301 PPP_AT,
302 PPP_MPLS_UC,
303 PPP_MPLS_MC,
304 };
305
306 /* Translates an ethertype into an NP index */
307 static inline int ethertype_to_npindex(int ethertype)
308 {
309 switch (ethertype) {
310 case ETH_P_IP:
311 return NP_IP;
312 case ETH_P_IPV6:
313 return NP_IPV6;
314 case ETH_P_IPX:
315 return NP_IPX;
316 case ETH_P_PPPTALK:
317 case ETH_P_ATALK:
318 return NP_AT;
319 case ETH_P_MPLS_UC:
320 return NP_MPLS_UC;
321 case ETH_P_MPLS_MC:
322 return NP_MPLS_MC;
323 }
324 return -1;
325 }
326
327 /* Translates an NP index into an ethertype */
328 static const int npindex_to_ethertype[NUM_NP] = {
329 ETH_P_IP,
330 ETH_P_IPV6,
331 ETH_P_IPX,
332 ETH_P_PPPTALK,
333 ETH_P_MPLS_UC,
334 ETH_P_MPLS_MC,
335 };
336
337 /*
338 * Locking shorthand.
339 */
340 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
341 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
342 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
343 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
344 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
345 ppp_recv_lock(ppp); } while (0)
346 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
347 ppp_xmit_unlock(ppp); } while (0)
348
349 /*
350 * /dev/ppp device routines.
351 * The /dev/ppp device is used by pppd to control the ppp unit.
352 * It supports the read, write, ioctl and poll functions.
353 * Open instances of /dev/ppp can be in one of three states:
354 * unattached, attached to a ppp unit, or attached to a ppp channel.
355 */
356 static int ppp_open(struct inode *inode, struct file *file)
357 {
358 /*
359 * This could (should?) be enforced by the permissions on /dev/ppp.
360 */
361 if (!capable(CAP_NET_ADMIN))
362 return -EPERM;
363 return 0;
364 }
365
366 static int ppp_release(struct inode *inode, struct file *file)
367 {
368 struct ppp_file *pf = file->private_data;
369 struct ppp *ppp;
370
371 if (pf != 0) {
372 file->private_data = NULL;
373 if (pf->kind == INTERFACE) {
374 ppp = PF_TO_PPP(pf);
375 if (file == ppp->owner)
376 ppp_shutdown_interface(ppp);
377 }
378 if (atomic_dec_and_test(&pf->refcnt)) {
379 switch (pf->kind) {
380 case INTERFACE:
381 ppp_destroy_interface(PF_TO_PPP(pf));
382 break;
383 case CHANNEL:
384 ppp_destroy_channel(PF_TO_CHANNEL(pf));
385 break;
386 }
387 }
388 }
389 return 0;
390 }
391
392 static ssize_t ppp_read(struct file *file, char __user *buf,
393 size_t count, loff_t *ppos)
394 {
395 struct ppp_file *pf = file->private_data;
396 DECLARE_WAITQUEUE(wait, current);
397 ssize_t ret;
398 struct sk_buff *skb = NULL;
399
400 ret = count;
401
402 if (pf == 0)
403 return -ENXIO;
404 add_wait_queue(&pf->rwait, &wait);
405 for (;;) {
406 set_current_state(TASK_INTERRUPTIBLE);
407 skb = skb_dequeue(&pf->rq);
408 if (skb)
409 break;
410 ret = 0;
411 if (pf->dead)
412 break;
413 if (pf->kind == INTERFACE) {
414 /*
415 * Return 0 (EOF) on an interface that has no
416 * channels connected, unless it is looping
417 * network traffic (demand mode).
418 */
419 struct ppp *ppp = PF_TO_PPP(pf);
420 if (ppp->n_channels == 0
421 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
422 break;
423 }
424 ret = -EAGAIN;
425 if (file->f_flags & O_NONBLOCK)
426 break;
427 ret = -ERESTARTSYS;
428 if (signal_pending(current))
429 break;
430 schedule();
431 }
432 set_current_state(TASK_RUNNING);
433 remove_wait_queue(&pf->rwait, &wait);
434
435 if (skb == 0)
436 goto out;
437
438 ret = -EOVERFLOW;
439 if (skb->len > count)
440 goto outf;
441 ret = -EFAULT;
442 if (copy_to_user(buf, skb->data, skb->len))
443 goto outf;
444 ret = skb->len;
445
446 outf:
447 kfree_skb(skb);
448 out:
449 return ret;
450 }
451
452 static ssize_t ppp_write(struct file *file, const char __user *buf,
453 size_t count, loff_t *ppos)
454 {
455 struct ppp_file *pf = file->private_data;
456 struct sk_buff *skb;
457 ssize_t ret;
458
459 if (pf == 0)
460 return -ENXIO;
461 ret = -ENOMEM;
462 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
463 if (skb == 0)
464 goto out;
465 skb_reserve(skb, pf->hdrlen);
466 ret = -EFAULT;
467 if (copy_from_user(skb_put(skb, count), buf, count)) {
468 kfree_skb(skb);
469 goto out;
470 }
471
472 skb_queue_tail(&pf->xq, skb);
473
474 switch (pf->kind) {
475 case INTERFACE:
476 ppp_xmit_process(PF_TO_PPP(pf));
477 break;
478 case CHANNEL:
479 ppp_channel_push(PF_TO_CHANNEL(pf));
480 break;
481 }
482
483 ret = count;
484
485 out:
486 return ret;
487 }
488
489 /* No kernel lock - fine */
490 static unsigned int ppp_poll(struct file *file, poll_table *wait)
491 {
492 struct ppp_file *pf = file->private_data;
493 unsigned int mask;
494
495 if (pf == 0)
496 return 0;
497 poll_wait(file, &pf->rwait, wait);
498 mask = POLLOUT | POLLWRNORM;
499 if (skb_peek(&pf->rq) != 0)
500 mask |= POLLIN | POLLRDNORM;
501 if (pf->dead)
502 mask |= POLLHUP;
503 else if (pf->kind == INTERFACE) {
504 /* see comment in ppp_read */
505 struct ppp *ppp = PF_TO_PPP(pf);
506 if (ppp->n_channels == 0
507 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
508 mask |= POLLIN | POLLRDNORM;
509 }
510
511 return mask;
512 }
513
514 #ifdef CONFIG_PPP_FILTER
515 static int get_filter(void __user *arg, struct sock_filter **p)
516 {
517 struct sock_fprog uprog;
518 struct sock_filter *code = NULL;
519 int len, err;
520
521 if (copy_from_user(&uprog, arg, sizeof(uprog)))
522 return -EFAULT;
523
524 if (!uprog.len) {
525 *p = NULL;
526 return 0;
527 }
528
529 len = uprog.len * sizeof(struct sock_filter);
530 code = kmalloc(len, GFP_KERNEL);
531 if (code == NULL)
532 return -ENOMEM;
533
534 if (copy_from_user(code, uprog.filter, len)) {
535 kfree(code);
536 return -EFAULT;
537 }
538
539 err = sk_chk_filter(code, uprog.len);
540 if (err) {
541 kfree(code);
542 return err;
543 }
544
545 *p = code;
546 return uprog.len;
547 }
548 #endif /* CONFIG_PPP_FILTER */
549
550 static int ppp_ioctl(struct inode *inode, struct file *file,
551 unsigned int cmd, unsigned long arg)
552 {
553 struct ppp_file *pf = file->private_data;
554 struct ppp *ppp;
555 int err = -EFAULT, val, val2, i;
556 struct ppp_idle idle;
557 struct npioctl npi;
558 int unit, cflags;
559 struct slcompress *vj;
560 void __user *argp = (void __user *)arg;
561 int __user *p = argp;
562
563 if (pf == 0)
564 return ppp_unattached_ioctl(pf, file, cmd, arg);
565
566 if (cmd == PPPIOCDETACH) {
567 /*
568 * We have to be careful here... if the file descriptor
569 * has been dup'd, we could have another process in the
570 * middle of a poll using the same file *, so we had
571 * better not free the interface data structures -
572 * instead we fail the ioctl. Even in this case, we
573 * shut down the interface if we are the owner of it.
574 * Actually, we should get rid of PPPIOCDETACH, userland
575 * (i.e. pppd) could achieve the same effect by closing
576 * this fd and reopening /dev/ppp.
577 */
578 err = -EINVAL;
579 if (pf->kind == INTERFACE) {
580 ppp = PF_TO_PPP(pf);
581 if (file == ppp->owner)
582 ppp_shutdown_interface(ppp);
583 }
584 if (atomic_read(&file->f_count) <= 2) {
585 ppp_release(inode, file);
586 err = 0;
587 } else
588 printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%d\n",
589 atomic_read(&file->f_count));
590 return err;
591 }
592
593 if (pf->kind == CHANNEL) {
594 struct channel *pch = PF_TO_CHANNEL(pf);
595 struct ppp_channel *chan;
596
597 switch (cmd) {
598 case PPPIOCCONNECT:
599 if (get_user(unit, p))
600 break;
601 err = ppp_connect_channel(pch, unit);
602 break;
603
604 case PPPIOCDISCONN:
605 err = ppp_disconnect_channel(pch);
606 break;
607
608 default:
609 down_read(&pch->chan_sem);
610 chan = pch->chan;
611 err = -ENOTTY;
612 if (chan && chan->ops->ioctl)
613 err = chan->ops->ioctl(chan, cmd, arg);
614 up_read(&pch->chan_sem);
615 }
616 return err;
617 }
618
619 if (pf->kind != INTERFACE) {
620 /* can't happen */
621 printk(KERN_ERR "PPP: not interface or channel??\n");
622 return -EINVAL;
623 }
624
625 ppp = PF_TO_PPP(pf);
626 switch (cmd) {
627 case PPPIOCSMRU:
628 if (get_user(val, p))
629 break;
630 ppp->mru = val;
631 err = 0;
632 break;
633
634 case PPPIOCSFLAGS:
635 if (get_user(val, p))
636 break;
637 ppp_lock(ppp);
638 cflags = ppp->flags & ~val;
639 ppp->flags = val & SC_FLAG_BITS;
640 ppp_unlock(ppp);
641 if (cflags & SC_CCP_OPEN)
642 ppp_ccp_closed(ppp);
643 err = 0;
644 break;
645
646 case PPPIOCGFLAGS:
647 val = ppp->flags | ppp->xstate | ppp->rstate;
648 if (put_user(val, p))
649 break;
650 err = 0;
651 break;
652
653 case PPPIOCSCOMPRESS:
654 err = ppp_set_compress(ppp, arg);
655 break;
656
657 case PPPIOCGUNIT:
658 if (put_user(ppp->file.index, p))
659 break;
660 err = 0;
661 break;
662
663 case PPPIOCSDEBUG:
664 if (get_user(val, p))
665 break;
666 ppp->debug = val;
667 err = 0;
668 break;
669
670 case PPPIOCGDEBUG:
671 if (put_user(ppp->debug, p))
672 break;
673 err = 0;
674 break;
675
676 case PPPIOCGIDLE:
677 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
678 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
679 if (copy_to_user(argp, &idle, sizeof(idle)))
680 break;
681 err = 0;
682 break;
683
684 case PPPIOCSMAXCID:
685 if (get_user(val, p))
686 break;
687 val2 = 15;
688 if ((val >> 16) != 0) {
689 val2 = val >> 16;
690 val &= 0xffff;
691 }
692 vj = slhc_init(val2+1, val+1);
693 if (vj == 0) {
694 printk(KERN_ERR "PPP: no memory (VJ compressor)\n");
695 err = -ENOMEM;
696 break;
697 }
698 ppp_lock(ppp);
699 if (ppp->vj != 0)
700 slhc_free(ppp->vj);
701 ppp->vj = vj;
702 ppp_unlock(ppp);
703 err = 0;
704 break;
705
706 case PPPIOCGNPMODE:
707 case PPPIOCSNPMODE:
708 if (copy_from_user(&npi, argp, sizeof(npi)))
709 break;
710 err = proto_to_npindex(npi.protocol);
711 if (err < 0)
712 break;
713 i = err;
714 if (cmd == PPPIOCGNPMODE) {
715 err = -EFAULT;
716 npi.mode = ppp->npmode[i];
717 if (copy_to_user(argp, &npi, sizeof(npi)))
718 break;
719 } else {
720 ppp->npmode[i] = npi.mode;
721 /* we may be able to transmit more packets now (??) */
722 netif_wake_queue(ppp->dev);
723 }
724 err = 0;
725 break;
726
727 #ifdef CONFIG_PPP_FILTER
728 case PPPIOCSPASS:
729 {
730 struct sock_filter *code;
731 err = get_filter(argp, &code);
732 if (err >= 0) {
733 ppp_lock(ppp);
734 kfree(ppp->pass_filter);
735 ppp->pass_filter = code;
736 ppp->pass_len = err;
737 ppp_unlock(ppp);
738 err = 0;
739 }
740 break;
741 }
742 case PPPIOCSACTIVE:
743 {
744 struct sock_filter *code;
745 err = get_filter(argp, &code);
746 if (err >= 0) {
747 ppp_lock(ppp);
748 kfree(ppp->active_filter);
749 ppp->active_filter = code;
750 ppp->active_len = err;
751 ppp_unlock(ppp);
752 err = 0;
753 }
754 break;
755 }
756 #endif /* CONFIG_PPP_FILTER */
757
758 #ifdef CONFIG_PPP_MULTILINK
759 case PPPIOCSMRRU:
760 if (get_user(val, p))
761 break;
762 ppp_recv_lock(ppp);
763 ppp->mrru = val;
764 ppp_recv_unlock(ppp);
765 err = 0;
766 break;
767 #endif /* CONFIG_PPP_MULTILINK */
768
769 default:
770 err = -ENOTTY;
771 }
772
773 return err;
774 }
775
776 static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file,
777 unsigned int cmd, unsigned long arg)
778 {
779 int unit, err = -EFAULT;
780 struct ppp *ppp;
781 struct channel *chan;
782 int __user *p = (int __user *)arg;
783
784 switch (cmd) {
785 case PPPIOCNEWUNIT:
786 /* Create a new ppp unit */
787 if (get_user(unit, p))
788 break;
789 ppp = ppp_create_interface(unit, &err);
790 if (ppp == 0)
791 break;
792 file->private_data = &ppp->file;
793 ppp->owner = file;
794 err = -EFAULT;
795 if (put_user(ppp->file.index, p))
796 break;
797 err = 0;
798 break;
799
800 case PPPIOCATTACH:
801 /* Attach to an existing ppp unit */
802 if (get_user(unit, p))
803 break;
804 mutex_lock(&all_ppp_mutex);
805 err = -ENXIO;
806 ppp = ppp_find_unit(unit);
807 if (ppp != 0) {
808 atomic_inc(&ppp->file.refcnt);
809 file->private_data = &ppp->file;
810 err = 0;
811 }
812 mutex_unlock(&all_ppp_mutex);
813 break;
814
815 case PPPIOCATTCHAN:
816 if (get_user(unit, p))
817 break;
818 spin_lock_bh(&all_channels_lock);
819 err = -ENXIO;
820 chan = ppp_find_channel(unit);
821 if (chan != 0) {
822 atomic_inc(&chan->file.refcnt);
823 file->private_data = &chan->file;
824 err = 0;
825 }
826 spin_unlock_bh(&all_channels_lock);
827 break;
828
829 default:
830 err = -ENOTTY;
831 }
832 return err;
833 }
834
835 static const struct file_operations ppp_device_fops = {
836 .owner = THIS_MODULE,
837 .read = ppp_read,
838 .write = ppp_write,
839 .poll = ppp_poll,
840 .ioctl = ppp_ioctl,
841 .open = ppp_open,
842 .release = ppp_release
843 };
844
845 #define PPP_MAJOR 108
846
847 /* Called at boot time if ppp is compiled into the kernel,
848 or at module load time (from init_module) if compiled as a module. */
849 static int __init ppp_init(void)
850 {
851 int err;
852
853 printk(KERN_INFO "PPP generic driver version " PPP_VERSION "\n");
854 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
855 if (!err) {
856 ppp_class = class_create(THIS_MODULE, "ppp");
857 if (IS_ERR(ppp_class)) {
858 err = PTR_ERR(ppp_class);
859 goto out_chrdev;
860 }
861 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), "ppp");
862 }
863
864 out:
865 if (err)
866 printk(KERN_ERR "failed to register PPP device (%d)\n", err);
867 return err;
868
869 out_chrdev:
870 unregister_chrdev(PPP_MAJOR, "ppp");
871 goto out;
872 }
873
874 /*
875 * Network interface unit routines.
876 */
877 static int
878 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
879 {
880 struct ppp *ppp = (struct ppp *) dev->priv;
881 int npi, proto;
882 unsigned char *pp;
883
884 npi = ethertype_to_npindex(ntohs(skb->protocol));
885 if (npi < 0)
886 goto outf;
887
888 /* Drop, accept or reject the packet */
889 switch (ppp->npmode[npi]) {
890 case NPMODE_PASS:
891 break;
892 case NPMODE_QUEUE:
893 /* it would be nice to have a way to tell the network
894 system to queue this one up for later. */
895 goto outf;
896 case NPMODE_DROP:
897 case NPMODE_ERROR:
898 goto outf;
899 }
900
901 /* Put the 2-byte PPP protocol number on the front,
902 making sure there is room for the address and control fields. */
903 if (skb_headroom(skb) < PPP_HDRLEN) {
904 struct sk_buff *ns;
905
906 ns = alloc_skb(skb->len + dev->hard_header_len, GFP_ATOMIC);
907 if (ns == 0)
908 goto outf;
909 skb_reserve(ns, dev->hard_header_len);
910 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
911 kfree_skb(skb);
912 skb = ns;
913 }
914 pp = skb_push(skb, 2);
915 proto = npindex_to_proto[npi];
916 pp[0] = proto >> 8;
917 pp[1] = proto;
918
919 netif_stop_queue(dev);
920 skb_queue_tail(&ppp->file.xq, skb);
921 ppp_xmit_process(ppp);
922 return 0;
923
924 outf:
925 kfree_skb(skb);
926 ++ppp->stats.tx_dropped;
927 return 0;
928 }
929
930 static struct net_device_stats *
931 ppp_net_stats(struct net_device *dev)
932 {
933 struct ppp *ppp = (struct ppp *) dev->priv;
934
935 return &ppp->stats;
936 }
937
938 static int
939 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
940 {
941 struct ppp *ppp = dev->priv;
942 int err = -EFAULT;
943 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
944 struct ppp_stats stats;
945 struct ppp_comp_stats cstats;
946 char *vers;
947
948 switch (cmd) {
949 case SIOCGPPPSTATS:
950 ppp_get_stats(ppp, &stats);
951 if (copy_to_user(addr, &stats, sizeof(stats)))
952 break;
953 err = 0;
954 break;
955
956 case SIOCGPPPCSTATS:
957 memset(&cstats, 0, sizeof(cstats));
958 if (ppp->xc_state != 0)
959 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
960 if (ppp->rc_state != 0)
961 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
962 if (copy_to_user(addr, &cstats, sizeof(cstats)))
963 break;
964 err = 0;
965 break;
966
967 case SIOCGPPPVER:
968 vers = PPP_VERSION;
969 if (copy_to_user(addr, vers, strlen(vers) + 1))
970 break;
971 err = 0;
972 break;
973
974 default:
975 err = -EINVAL;
976 }
977
978 return err;
979 }
980
981 static void ppp_setup(struct net_device *dev)
982 {
983 dev->hard_header_len = PPP_HDRLEN;
984 dev->mtu = PPP_MTU;
985 dev->addr_len = 0;
986 dev->tx_queue_len = 3;
987 dev->type = ARPHRD_PPP;
988 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
989 }
990
991 /*
992 * Transmit-side routines.
993 */
994
995 /*
996 * Called to do any work queued up on the transmit side
997 * that can now be done.
998 */
999 static void
1000 ppp_xmit_process(struct ppp *ppp)
1001 {
1002 struct sk_buff *skb;
1003
1004 ppp_xmit_lock(ppp);
1005 if (ppp->dev != 0) {
1006 ppp_push(ppp);
1007 while (ppp->xmit_pending == 0
1008 && (skb = skb_dequeue(&ppp->file.xq)) != 0)
1009 ppp_send_frame(ppp, skb);
1010 /* If there's no work left to do, tell the core net
1011 code that we can accept some more. */
1012 if (ppp->xmit_pending == 0 && skb_peek(&ppp->file.xq) == 0)
1013 netif_wake_queue(ppp->dev);
1014 }
1015 ppp_xmit_unlock(ppp);
1016 }
1017
1018 static inline struct sk_buff *
1019 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1020 {
1021 struct sk_buff *new_skb;
1022 int len;
1023 int new_skb_size = ppp->dev->mtu +
1024 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1025 int compressor_skb_size = ppp->dev->mtu +
1026 ppp->xcomp->comp_extra + PPP_HDRLEN;
1027 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1028 if (!new_skb) {
1029 if (net_ratelimit())
1030 printk(KERN_ERR "PPP: no memory (comp pkt)\n");
1031 return NULL;
1032 }
1033 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1034 skb_reserve(new_skb,
1035 ppp->dev->hard_header_len - PPP_HDRLEN);
1036
1037 /* compressor still expects A/C bytes in hdr */
1038 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1039 new_skb->data, skb->len + 2,
1040 compressor_skb_size);
1041 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1042 kfree_skb(skb);
1043 skb = new_skb;
1044 skb_put(skb, len);
1045 skb_pull(skb, 2); /* pull off A/C bytes */
1046 } else if (len == 0) {
1047 /* didn't compress, or CCP not up yet */
1048 kfree_skb(new_skb);
1049 new_skb = skb;
1050 } else {
1051 /*
1052 * (len < 0)
1053 * MPPE requires that we do not send unencrypted
1054 * frames. The compressor will return -1 if we
1055 * should drop the frame. We cannot simply test
1056 * the compress_proto because MPPE and MPPC share
1057 * the same number.
1058 */
1059 if (net_ratelimit())
1060 printk(KERN_ERR "ppp: compressor dropped pkt\n");
1061 kfree_skb(skb);
1062 kfree_skb(new_skb);
1063 new_skb = NULL;
1064 }
1065 return new_skb;
1066 }
1067
1068 /*
1069 * Compress and send a frame.
1070 * The caller should have locked the xmit path,
1071 * and xmit_pending should be 0.
1072 */
1073 static void
1074 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1075 {
1076 int proto = PPP_PROTO(skb);
1077 struct sk_buff *new_skb;
1078 int len;
1079 unsigned char *cp;
1080
1081 if (proto < 0x8000) {
1082 #ifdef CONFIG_PPP_FILTER
1083 /* check if we should pass this packet */
1084 /* the filter instructions are constructed assuming
1085 a four-byte PPP header on each packet */
1086 *skb_push(skb, 2) = 1;
1087 if (ppp->pass_filter
1088 && sk_run_filter(skb, ppp->pass_filter,
1089 ppp->pass_len) == 0) {
1090 if (ppp->debug & 1)
1091 printk(KERN_DEBUG "PPP: outbound frame not passed\n");
1092 kfree_skb(skb);
1093 return;
1094 }
1095 /* if this packet passes the active filter, record the time */
1096 if (!(ppp->active_filter
1097 && sk_run_filter(skb, ppp->active_filter,
1098 ppp->active_len) == 0))
1099 ppp->last_xmit = jiffies;
1100 skb_pull(skb, 2);
1101 #else
1102 /* for data packets, record the time */
1103 ppp->last_xmit = jiffies;
1104 #endif /* CONFIG_PPP_FILTER */
1105 }
1106
1107 ++ppp->stats.tx_packets;
1108 ppp->stats.tx_bytes += skb->len - 2;
1109
1110 switch (proto) {
1111 case PPP_IP:
1112 if (ppp->vj == 0 || (ppp->flags & SC_COMP_TCP) == 0)
1113 break;
1114 /* try to do VJ TCP header compression */
1115 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1116 GFP_ATOMIC);
1117 if (new_skb == 0) {
1118 printk(KERN_ERR "PPP: no memory (VJ comp pkt)\n");
1119 goto drop;
1120 }
1121 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1122 cp = skb->data + 2;
1123 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1124 new_skb->data + 2, &cp,
1125 !(ppp->flags & SC_NO_TCP_CCID));
1126 if (cp == skb->data + 2) {
1127 /* didn't compress */
1128 kfree_skb(new_skb);
1129 } else {
1130 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1131 proto = PPP_VJC_COMP;
1132 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1133 } else {
1134 proto = PPP_VJC_UNCOMP;
1135 cp[0] = skb->data[2];
1136 }
1137 kfree_skb(skb);
1138 skb = new_skb;
1139 cp = skb_put(skb, len + 2);
1140 cp[0] = 0;
1141 cp[1] = proto;
1142 }
1143 break;
1144
1145 case PPP_CCP:
1146 /* peek at outbound CCP frames */
1147 ppp_ccp_peek(ppp, skb, 0);
1148 break;
1149 }
1150
1151 /* try to do packet compression */
1152 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state != 0
1153 && proto != PPP_LCP && proto != PPP_CCP) {
1154 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1155 if (net_ratelimit())
1156 printk(KERN_ERR "ppp: compression required but down - pkt dropped.\n");
1157 goto drop;
1158 }
1159 skb = pad_compress_skb(ppp, skb);
1160 if (!skb)
1161 goto drop;
1162 }
1163
1164 /*
1165 * If we are waiting for traffic (demand dialling),
1166 * queue it up for pppd to receive.
1167 */
1168 if (ppp->flags & SC_LOOP_TRAFFIC) {
1169 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1170 goto drop;
1171 skb_queue_tail(&ppp->file.rq, skb);
1172 wake_up_interruptible(&ppp->file.rwait);
1173 return;
1174 }
1175
1176 ppp->xmit_pending = skb;
1177 ppp_push(ppp);
1178 return;
1179
1180 drop:
1181 if (skb)
1182 kfree_skb(skb);
1183 ++ppp->stats.tx_errors;
1184 }
1185
1186 /*
1187 * Try to send the frame in xmit_pending.
1188 * The caller should have the xmit path locked.
1189 */
1190 static void
1191 ppp_push(struct ppp *ppp)
1192 {
1193 struct list_head *list;
1194 struct channel *pch;
1195 struct sk_buff *skb = ppp->xmit_pending;
1196
1197 if (skb == 0)
1198 return;
1199
1200 list = &ppp->channels;
1201 if (list_empty(list)) {
1202 /* nowhere to send the packet, just drop it */
1203 ppp->xmit_pending = NULL;
1204 kfree_skb(skb);
1205 return;
1206 }
1207
1208 if ((ppp->flags & SC_MULTILINK) == 0) {
1209 /* not doing multilink: send it down the first channel */
1210 list = list->next;
1211 pch = list_entry(list, struct channel, clist);
1212
1213 spin_lock_bh(&pch->downl);
1214 if (pch->chan) {
1215 if (pch->chan->ops->start_xmit(pch->chan, skb))
1216 ppp->xmit_pending = NULL;
1217 } else {
1218 /* channel got unregistered */
1219 kfree_skb(skb);
1220 ppp->xmit_pending = NULL;
1221 }
1222 spin_unlock_bh(&pch->downl);
1223 return;
1224 }
1225
1226 #ifdef CONFIG_PPP_MULTILINK
1227 /* Multilink: fragment the packet over as many links
1228 as can take the packet at the moment. */
1229 if (!ppp_mp_explode(ppp, skb))
1230 return;
1231 #endif /* CONFIG_PPP_MULTILINK */
1232
1233 ppp->xmit_pending = NULL;
1234 kfree_skb(skb);
1235 }
1236
1237 #ifdef CONFIG_PPP_MULTILINK
1238 /*
1239 * Divide a packet to be transmitted into fragments and
1240 * send them out the individual links.
1241 */
1242 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1243 {
1244 int len, fragsize;
1245 int i, bits, hdrlen, mtu;
1246 int flen;
1247 int navail, nfree;
1248 int nbigger;
1249 unsigned char *p, *q;
1250 struct list_head *list;
1251 struct channel *pch;
1252 struct sk_buff *frag;
1253 struct ppp_channel *chan;
1254
1255 nfree = 0; /* # channels which have no packet already queued */
1256 navail = 0; /* total # of usable channels (not deregistered) */
1257 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1258 i = 0;
1259 list_for_each_entry(pch, &ppp->channels, clist) {
1260 navail += pch->avail = (pch->chan != NULL);
1261 if (pch->avail) {
1262 if (skb_queue_empty(&pch->file.xq) ||
1263 !pch->had_frag) {
1264 pch->avail = 2;
1265 ++nfree;
1266 }
1267 if (!pch->had_frag && i < ppp->nxchan)
1268 ppp->nxchan = i;
1269 }
1270 ++i;
1271 }
1272
1273 /*
1274 * Don't start sending this packet unless at least half of
1275 * the channels are free. This gives much better TCP
1276 * performance if we have a lot of channels.
1277 */
1278 if (nfree == 0 || nfree < navail / 2)
1279 return 0; /* can't take now, leave it in xmit_pending */
1280
1281 /* Do protocol field compression (XXX this should be optional) */
1282 p = skb->data;
1283 len = skb->len;
1284 if (*p == 0) {
1285 ++p;
1286 --len;
1287 }
1288
1289 /*
1290 * Decide on fragment size.
1291 * We create a fragment for each free channel regardless of
1292 * how small they are (i.e. even 0 length) in order to minimize
1293 * the time that it will take to detect when a channel drops
1294 * a fragment.
1295 */
1296 fragsize = len;
1297 if (nfree > 1)
1298 fragsize = DIV_ROUND_UP(fragsize, nfree);
1299 /* nbigger channels get fragsize bytes, the rest get fragsize-1,
1300 except if nbigger==0, then they all get fragsize. */
1301 nbigger = len % nfree;
1302
1303 /* skip to the channel after the one we last used
1304 and start at that one */
1305 list = &ppp->channels;
1306 for (i = 0; i < ppp->nxchan; ++i) {
1307 list = list->next;
1308 if (list == &ppp->channels) {
1309 i = 0;
1310 break;
1311 }
1312 }
1313
1314 /* create a fragment for each channel */
1315 bits = B;
1316 while (nfree > 0 || len > 0) {
1317 list = list->next;
1318 if (list == &ppp->channels) {
1319 i = 0;
1320 continue;
1321 }
1322 pch = list_entry(list, struct channel, clist);
1323 ++i;
1324 if (!pch->avail)
1325 continue;
1326
1327 /*
1328 * Skip this channel if it has a fragment pending already and
1329 * we haven't given a fragment to all of the free channels.
1330 */
1331 if (pch->avail == 1) {
1332 if (nfree > 0)
1333 continue;
1334 } else {
1335 --nfree;
1336 pch->avail = 1;
1337 }
1338
1339 /* check the channel's mtu and whether it is still attached. */
1340 spin_lock_bh(&pch->downl);
1341 if (pch->chan == NULL) {
1342 /* can't use this channel, it's being deregistered */
1343 spin_unlock_bh(&pch->downl);
1344 pch->avail = 0;
1345 if (--navail == 0)
1346 break;
1347 continue;
1348 }
1349
1350 /*
1351 * Create a fragment for this channel of
1352 * min(max(mtu+2-hdrlen, 4), fragsize, len) bytes.
1353 * If mtu+2-hdrlen < 4, that is a ridiculously small
1354 * MTU, so we use mtu = 2 + hdrlen.
1355 */
1356 if (fragsize > len)
1357 fragsize = len;
1358 flen = fragsize;
1359 mtu = pch->chan->mtu + 2 - hdrlen;
1360 if (mtu < 4)
1361 mtu = 4;
1362 if (flen > mtu)
1363 flen = mtu;
1364 if (flen == len && nfree == 0)
1365 bits |= E;
1366 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1367 if (frag == 0)
1368 goto noskb;
1369 q = skb_put(frag, flen + hdrlen);
1370
1371 /* make the MP header */
1372 q[0] = PPP_MP >> 8;
1373 q[1] = PPP_MP;
1374 if (ppp->flags & SC_MP_XSHORTSEQ) {
1375 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1376 q[3] = ppp->nxseq;
1377 } else {
1378 q[2] = bits;
1379 q[3] = ppp->nxseq >> 16;
1380 q[4] = ppp->nxseq >> 8;
1381 q[5] = ppp->nxseq;
1382 }
1383
1384 /*
1385 * Copy the data in.
1386 * Unfortunately there is a bug in older versions of
1387 * the Linux PPP multilink reconstruction code where it
1388 * drops 0-length fragments. Therefore we make sure the
1389 * fragment has at least one byte of data. Any bytes
1390 * we add in this situation will end up as padding on the
1391 * end of the reconstructed packet.
1392 */
1393 if (flen == 0)
1394 *skb_put(frag, 1) = 0;
1395 else
1396 memcpy(q + hdrlen, p, flen);
1397
1398 /* try to send it down the channel */
1399 chan = pch->chan;
1400 if (!skb_queue_empty(&pch->file.xq) ||
1401 !chan->ops->start_xmit(chan, frag))
1402 skb_queue_tail(&pch->file.xq, frag);
1403 pch->had_frag = 1;
1404 p += flen;
1405 len -= flen;
1406 ++ppp->nxseq;
1407 bits = 0;
1408 spin_unlock_bh(&pch->downl);
1409
1410 if (--nbigger == 0 && fragsize > 0)
1411 --fragsize;
1412 }
1413 ppp->nxchan = i;
1414
1415 return 1;
1416
1417 noskb:
1418 spin_unlock_bh(&pch->downl);
1419 if (ppp->debug & 1)
1420 printk(KERN_ERR "PPP: no memory (fragment)\n");
1421 ++ppp->stats.tx_errors;
1422 ++ppp->nxseq;
1423 return 1; /* abandon the frame */
1424 }
1425 #endif /* CONFIG_PPP_MULTILINK */
1426
1427 /*
1428 * Try to send data out on a channel.
1429 */
1430 static void
1431 ppp_channel_push(struct channel *pch)
1432 {
1433 struct sk_buff *skb;
1434 struct ppp *ppp;
1435
1436 spin_lock_bh(&pch->downl);
1437 if (pch->chan != 0) {
1438 while (!skb_queue_empty(&pch->file.xq)) {
1439 skb = skb_dequeue(&pch->file.xq);
1440 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1441 /* put the packet back and try again later */
1442 skb_queue_head(&pch->file.xq, skb);
1443 break;
1444 }
1445 }
1446 } else {
1447 /* channel got deregistered */
1448 skb_queue_purge(&pch->file.xq);
1449 }
1450 spin_unlock_bh(&pch->downl);
1451 /* see if there is anything from the attached unit to be sent */
1452 if (skb_queue_empty(&pch->file.xq)) {
1453 read_lock_bh(&pch->upl);
1454 ppp = pch->ppp;
1455 if (ppp != 0)
1456 ppp_xmit_process(ppp);
1457 read_unlock_bh(&pch->upl);
1458 }
1459 }
1460
1461 /*
1462 * Receive-side routines.
1463 */
1464
1465 /* misuse a few fields of the skb for MP reconstruction */
1466 #define sequence priority
1467 #define BEbits cb[0]
1468
1469 static inline void
1470 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1471 {
1472 ppp_recv_lock(ppp);
1473 /* ppp->dev == 0 means interface is closing down */
1474 if (ppp->dev != 0)
1475 ppp_receive_frame(ppp, skb, pch);
1476 else
1477 kfree_skb(skb);
1478 ppp_recv_unlock(ppp);
1479 }
1480
1481 void
1482 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1483 {
1484 struct channel *pch = chan->ppp;
1485 int proto;
1486
1487 if (pch == 0 || skb->len == 0) {
1488 kfree_skb(skb);
1489 return;
1490 }
1491
1492 proto = PPP_PROTO(skb);
1493 read_lock_bh(&pch->upl);
1494 if (pch->ppp == 0 || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1495 /* put it on the channel queue */
1496 skb_queue_tail(&pch->file.rq, skb);
1497 /* drop old frames if queue too long */
1498 while (pch->file.rq.qlen > PPP_MAX_RQLEN
1499 && (skb = skb_dequeue(&pch->file.rq)) != 0)
1500 kfree_skb(skb);
1501 wake_up_interruptible(&pch->file.rwait);
1502 } else {
1503 ppp_do_recv(pch->ppp, skb, pch);
1504 }
1505 read_unlock_bh(&pch->upl);
1506 }
1507
1508 /* Put a 0-length skb in the receive queue as an error indication */
1509 void
1510 ppp_input_error(struct ppp_channel *chan, int code)
1511 {
1512 struct channel *pch = chan->ppp;
1513 struct sk_buff *skb;
1514
1515 if (pch == 0)
1516 return;
1517
1518 read_lock_bh(&pch->upl);
1519 if (pch->ppp != 0) {
1520 skb = alloc_skb(0, GFP_ATOMIC);
1521 if (skb != 0) {
1522 skb->len = 0; /* probably unnecessary */
1523 skb->cb[0] = code;
1524 ppp_do_recv(pch->ppp, skb, pch);
1525 }
1526 }
1527 read_unlock_bh(&pch->upl);
1528 }
1529
1530 /*
1531 * We come in here to process a received frame.
1532 * The receive side of the ppp unit is locked.
1533 */
1534 static void
1535 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1536 {
1537 if (skb->len >= 2) {
1538 #ifdef CONFIG_PPP_MULTILINK
1539 /* XXX do channel-level decompression here */
1540 if (PPP_PROTO(skb) == PPP_MP)
1541 ppp_receive_mp_frame(ppp, skb, pch);
1542 else
1543 #endif /* CONFIG_PPP_MULTILINK */
1544 ppp_receive_nonmp_frame(ppp, skb);
1545 return;
1546 }
1547
1548 if (skb->len > 0)
1549 /* note: a 0-length skb is used as an error indication */
1550 ++ppp->stats.rx_length_errors;
1551
1552 kfree_skb(skb);
1553 ppp_receive_error(ppp);
1554 }
1555
1556 static void
1557 ppp_receive_error(struct ppp *ppp)
1558 {
1559 ++ppp->stats.rx_errors;
1560 if (ppp->vj != 0)
1561 slhc_toss(ppp->vj);
1562 }
1563
1564 static void
1565 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1566 {
1567 struct sk_buff *ns;
1568 int proto, len, npi;
1569
1570 /*
1571 * Decompress the frame, if compressed.
1572 * Note that some decompressors need to see uncompressed frames
1573 * that come in as well as compressed frames.
1574 */
1575 if (ppp->rc_state != 0 && (ppp->rstate & SC_DECOMP_RUN)
1576 && (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1577 skb = ppp_decompress_frame(ppp, skb);
1578
1579 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1580 goto err;
1581
1582 proto = PPP_PROTO(skb);
1583 switch (proto) {
1584 case PPP_VJC_COMP:
1585 /* decompress VJ compressed packets */
1586 if (ppp->vj == 0 || (ppp->flags & SC_REJ_COMP_TCP))
1587 goto err;
1588
1589 if (skb_tailroom(skb) < 124) {
1590 /* copy to a new sk_buff with more tailroom */
1591 ns = dev_alloc_skb(skb->len + 128);
1592 if (ns == 0) {
1593 printk(KERN_ERR"PPP: no memory (VJ decomp)\n");
1594 goto err;
1595 }
1596 skb_reserve(ns, 2);
1597 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1598 kfree_skb(skb);
1599 skb = ns;
1600 }
1601 else
1602 skb->ip_summed = CHECKSUM_NONE;
1603
1604 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1605 if (len <= 0) {
1606 printk(KERN_DEBUG "PPP: VJ decompression error\n");
1607 goto err;
1608 }
1609 len += 2;
1610 if (len > skb->len)
1611 skb_put(skb, len - skb->len);
1612 else if (len < skb->len)
1613 skb_trim(skb, len);
1614 proto = PPP_IP;
1615 break;
1616
1617 case PPP_VJC_UNCOMP:
1618 if (ppp->vj == 0 || (ppp->flags & SC_REJ_COMP_TCP))
1619 goto err;
1620
1621 /* Until we fix the decompressor need to make sure
1622 * data portion is linear.
1623 */
1624 if (!pskb_may_pull(skb, skb->len))
1625 goto err;
1626
1627 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1628 printk(KERN_ERR "PPP: VJ uncompressed error\n");
1629 goto err;
1630 }
1631 proto = PPP_IP;
1632 break;
1633
1634 case PPP_CCP:
1635 ppp_ccp_peek(ppp, skb, 1);
1636 break;
1637 }
1638
1639 ++ppp->stats.rx_packets;
1640 ppp->stats.rx_bytes += skb->len - 2;
1641
1642 npi = proto_to_npindex(proto);
1643 if (npi < 0) {
1644 /* control or unknown frame - pass it to pppd */
1645 skb_queue_tail(&ppp->file.rq, skb);
1646 /* limit queue length by dropping old frames */
1647 while (ppp->file.rq.qlen > PPP_MAX_RQLEN
1648 && (skb = skb_dequeue(&ppp->file.rq)) != 0)
1649 kfree_skb(skb);
1650 /* wake up any process polling or blocking on read */
1651 wake_up_interruptible(&ppp->file.rwait);
1652
1653 } else {
1654 /* network protocol frame - give it to the kernel */
1655
1656 #ifdef CONFIG_PPP_FILTER
1657 /* check if the packet passes the pass and active filters */
1658 /* the filter instructions are constructed assuming
1659 a four-byte PPP header on each packet */
1660 *skb_push(skb, 2) = 0;
1661 if (ppp->pass_filter
1662 && sk_run_filter(skb, ppp->pass_filter,
1663 ppp->pass_len) == 0) {
1664 if (ppp->debug & 1)
1665 printk(KERN_DEBUG "PPP: inbound frame not passed\n");
1666 kfree_skb(skb);
1667 return;
1668 }
1669 if (!(ppp->active_filter
1670 && sk_run_filter(skb, ppp->active_filter,
1671 ppp->active_len) == 0))
1672 ppp->last_recv = jiffies;
1673 skb_pull(skb, 2);
1674 #else
1675 ppp->last_recv = jiffies;
1676 #endif /* CONFIG_PPP_FILTER */
1677
1678 if ((ppp->dev->flags & IFF_UP) == 0
1679 || ppp->npmode[npi] != NPMODE_PASS) {
1680 kfree_skb(skb);
1681 } else {
1682 /* chop off protocol */
1683 skb_pull_rcsum(skb, 2);
1684 skb->dev = ppp->dev;
1685 skb->protocol = htons(npindex_to_ethertype[npi]);
1686 skb_reset_mac_header(skb);
1687 netif_rx(skb);
1688 ppp->dev->last_rx = jiffies;
1689 }
1690 }
1691 return;
1692
1693 err:
1694 kfree_skb(skb);
1695 ppp_receive_error(ppp);
1696 }
1697
1698 static struct sk_buff *
1699 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1700 {
1701 int proto = PPP_PROTO(skb);
1702 struct sk_buff *ns;
1703 int len;
1704
1705 /* Until we fix all the decompressor's need to make sure
1706 * data portion is linear.
1707 */
1708 if (!pskb_may_pull(skb, skb->len))
1709 goto err;
1710
1711 if (proto == PPP_COMP) {
1712 ns = dev_alloc_skb(ppp->mru + PPP_HDRLEN);
1713 if (ns == 0) {
1714 printk(KERN_ERR "ppp_decompress_frame: no memory\n");
1715 goto err;
1716 }
1717 /* the decompressor still expects the A/C bytes in the hdr */
1718 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1719 skb->len + 2, ns->data, ppp->mru + PPP_HDRLEN);
1720 if (len < 0) {
1721 /* Pass the compressed frame to pppd as an
1722 error indication. */
1723 if (len == DECOMP_FATALERROR)
1724 ppp->rstate |= SC_DC_FERROR;
1725 kfree_skb(ns);
1726 goto err;
1727 }
1728
1729 kfree_skb(skb);
1730 skb = ns;
1731 skb_put(skb, len);
1732 skb_pull(skb, 2); /* pull off the A/C bytes */
1733
1734 } else {
1735 /* Uncompressed frame - pass to decompressor so it
1736 can update its dictionary if necessary. */
1737 if (ppp->rcomp->incomp)
1738 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1739 skb->len + 2);
1740 }
1741
1742 return skb;
1743
1744 err:
1745 ppp->rstate |= SC_DC_ERROR;
1746 ppp_receive_error(ppp);
1747 return skb;
1748 }
1749
1750 #ifdef CONFIG_PPP_MULTILINK
1751 /*
1752 * Receive a multilink frame.
1753 * We put it on the reconstruction queue and then pull off
1754 * as many completed frames as we can.
1755 */
1756 static void
1757 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1758 {
1759 u32 mask, seq;
1760 struct channel *ch;
1761 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1762
1763 if (!pskb_may_pull(skb, mphdrlen) || ppp->mrru == 0)
1764 goto err; /* no good, throw it away */
1765
1766 /* Decode sequence number and begin/end bits */
1767 if (ppp->flags & SC_MP_SHORTSEQ) {
1768 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1769 mask = 0xfff;
1770 } else {
1771 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1772 mask = 0xffffff;
1773 }
1774 skb->BEbits = skb->data[2];
1775 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
1776
1777 /*
1778 * Do protocol ID decompression on the first fragment of each packet.
1779 */
1780 if ((skb->BEbits & B) && (skb->data[0] & 1))
1781 *skb_push(skb, 1) = 0;
1782
1783 /*
1784 * Expand sequence number to 32 bits, making it as close
1785 * as possible to ppp->minseq.
1786 */
1787 seq |= ppp->minseq & ~mask;
1788 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
1789 seq += mask + 1;
1790 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
1791 seq -= mask + 1; /* should never happen */
1792 skb->sequence = seq;
1793 pch->lastseq = seq;
1794
1795 /*
1796 * If this packet comes before the next one we were expecting,
1797 * drop it.
1798 */
1799 if (seq_before(seq, ppp->nextseq)) {
1800 kfree_skb(skb);
1801 ++ppp->stats.rx_dropped;
1802 ppp_receive_error(ppp);
1803 return;
1804 }
1805
1806 /*
1807 * Reevaluate minseq, the minimum over all channels of the
1808 * last sequence number received on each channel. Because of
1809 * the increasing sequence number rule, we know that any fragment
1810 * before `minseq' which hasn't arrived is never going to arrive.
1811 * The list of channels can't change because we have the receive
1812 * side of the ppp unit locked.
1813 */
1814 list_for_each_entry(ch, &ppp->channels, clist) {
1815 if (seq_before(ch->lastseq, seq))
1816 seq = ch->lastseq;
1817 }
1818 if (seq_before(ppp->minseq, seq))
1819 ppp->minseq = seq;
1820
1821 /* Put the fragment on the reconstruction queue */
1822 ppp_mp_insert(ppp, skb);
1823
1824 /* If the queue is getting long, don't wait any longer for packets
1825 before the start of the queue. */
1826 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN
1827 && seq_before(ppp->minseq, ppp->mrq.next->sequence))
1828 ppp->minseq = ppp->mrq.next->sequence;
1829
1830 /* Pull completed packets off the queue and receive them. */
1831 while ((skb = ppp_mp_reconstruct(ppp)) != 0)
1832 ppp_receive_nonmp_frame(ppp, skb);
1833
1834 return;
1835
1836 err:
1837 kfree_skb(skb);
1838 ppp_receive_error(ppp);
1839 }
1840
1841 /*
1842 * Insert a fragment on the MP reconstruction queue.
1843 * The queue is ordered by increasing sequence number.
1844 */
1845 static void
1846 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
1847 {
1848 struct sk_buff *p;
1849 struct sk_buff_head *list = &ppp->mrq;
1850 u32 seq = skb->sequence;
1851
1852 /* N.B. we don't need to lock the list lock because we have the
1853 ppp unit receive-side lock. */
1854 for (p = list->next; p != (struct sk_buff *)list; p = p->next)
1855 if (seq_before(seq, p->sequence))
1856 break;
1857 __skb_insert(skb, p->prev, p, list);
1858 }
1859
1860 /*
1861 * Reconstruct a packet from the MP fragment queue.
1862 * We go through increasing sequence numbers until we find a
1863 * complete packet, or we get to the sequence number for a fragment
1864 * which hasn't arrived but might still do so.
1865 */
1866 struct sk_buff *
1867 ppp_mp_reconstruct(struct ppp *ppp)
1868 {
1869 u32 seq = ppp->nextseq;
1870 u32 minseq = ppp->minseq;
1871 struct sk_buff_head *list = &ppp->mrq;
1872 struct sk_buff *p, *next;
1873 struct sk_buff *head, *tail;
1874 struct sk_buff *skb = NULL;
1875 int lost = 0, len = 0;
1876
1877 if (ppp->mrru == 0) /* do nothing until mrru is set */
1878 return NULL;
1879 head = list->next;
1880 tail = NULL;
1881 for (p = head; p != (struct sk_buff *) list; p = next) {
1882 next = p->next;
1883 if (seq_before(p->sequence, seq)) {
1884 /* this can't happen, anyway ignore the skb */
1885 printk(KERN_ERR "ppp_mp_reconstruct bad seq %u < %u\n",
1886 p->sequence, seq);
1887 head = next;
1888 continue;
1889 }
1890 if (p->sequence != seq) {
1891 /* Fragment `seq' is missing. If it is after
1892 minseq, it might arrive later, so stop here. */
1893 if (seq_after(seq, minseq))
1894 break;
1895 /* Fragment `seq' is lost, keep going. */
1896 lost = 1;
1897 seq = seq_before(minseq, p->sequence)?
1898 minseq + 1: p->sequence;
1899 next = p;
1900 continue;
1901 }
1902
1903 /*
1904 * At this point we know that all the fragments from
1905 * ppp->nextseq to seq are either present or lost.
1906 * Also, there are no complete packets in the queue
1907 * that have no missing fragments and end before this
1908 * fragment.
1909 */
1910
1911 /* B bit set indicates this fragment starts a packet */
1912 if (p->BEbits & B) {
1913 head = p;
1914 lost = 0;
1915 len = 0;
1916 }
1917
1918 len += p->len;
1919
1920 /* Got a complete packet yet? */
1921 if (lost == 0 && (p->BEbits & E) && (head->BEbits & B)) {
1922 if (len > ppp->mrru + 2) {
1923 ++ppp->stats.rx_length_errors;
1924 printk(KERN_DEBUG "PPP: reconstructed packet"
1925 " is too long (%d)\n", len);
1926 } else if (p == head) {
1927 /* fragment is complete packet - reuse skb */
1928 tail = p;
1929 skb = skb_get(p);
1930 break;
1931 } else if ((skb = dev_alloc_skb(len)) == NULL) {
1932 ++ppp->stats.rx_missed_errors;
1933 printk(KERN_DEBUG "PPP: no memory for "
1934 "reconstructed packet");
1935 } else {
1936 tail = p;
1937 break;
1938 }
1939 ppp->nextseq = seq + 1;
1940 }
1941
1942 /*
1943 * If this is the ending fragment of a packet,
1944 * and we haven't found a complete valid packet yet,
1945 * we can discard up to and including this fragment.
1946 */
1947 if (p->BEbits & E)
1948 head = next;
1949
1950 ++seq;
1951 }
1952
1953 /* If we have a complete packet, copy it all into one skb. */
1954 if (tail != NULL) {
1955 /* If we have discarded any fragments,
1956 signal a receive error. */
1957 if (head->sequence != ppp->nextseq) {
1958 if (ppp->debug & 1)
1959 printk(KERN_DEBUG " missed pkts %u..%u\n",
1960 ppp->nextseq, head->sequence-1);
1961 ++ppp->stats.rx_dropped;
1962 ppp_receive_error(ppp);
1963 }
1964
1965 if (head != tail)
1966 /* copy to a single skb */
1967 for (p = head; p != tail->next; p = p->next)
1968 skb_copy_bits(p, 0, skb_put(skb, p->len), p->len);
1969 ppp->nextseq = tail->sequence + 1;
1970 head = tail->next;
1971 }
1972
1973 /* Discard all the skbuffs that we have copied the data out of
1974 or that we can't use. */
1975 while ((p = list->next) != head) {
1976 __skb_unlink(p, list);
1977 kfree_skb(p);
1978 }
1979
1980 return skb;
1981 }
1982 #endif /* CONFIG_PPP_MULTILINK */
1983
1984 /*
1985 * Channel interface.
1986 */
1987
1988 /*
1989 * Create a new, unattached ppp channel.
1990 */
1991 int
1992 ppp_register_channel(struct ppp_channel *chan)
1993 {
1994 struct channel *pch;
1995
1996 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
1997 if (pch == 0)
1998 return -ENOMEM;
1999 pch->ppp = NULL;
2000 pch->chan = chan;
2001 chan->ppp = pch;
2002 init_ppp_file(&pch->file, CHANNEL);
2003 pch->file.hdrlen = chan->hdrlen;
2004 #ifdef CONFIG_PPP_MULTILINK
2005 pch->lastseq = -1;
2006 #endif /* CONFIG_PPP_MULTILINK */
2007 init_rwsem(&pch->chan_sem);
2008 spin_lock_init(&pch->downl);
2009 rwlock_init(&pch->upl);
2010 spin_lock_bh(&all_channels_lock);
2011 pch->file.index = ++last_channel_index;
2012 list_add(&pch->list, &new_channels);
2013 atomic_inc(&channel_count);
2014 spin_unlock_bh(&all_channels_lock);
2015 return 0;
2016 }
2017
2018 /*
2019 * Return the index of a channel.
2020 */
2021 int ppp_channel_index(struct ppp_channel *chan)
2022 {
2023 struct channel *pch = chan->ppp;
2024
2025 if (pch != 0)
2026 return pch->file.index;
2027 return -1;
2028 }
2029
2030 /*
2031 * Return the PPP unit number to which a channel is connected.
2032 */
2033 int ppp_unit_number(struct ppp_channel *chan)
2034 {
2035 struct channel *pch = chan->ppp;
2036 int unit = -1;
2037
2038 if (pch != 0) {
2039 read_lock_bh(&pch->upl);
2040 if (pch->ppp != 0)
2041 unit = pch->ppp->file.index;
2042 read_unlock_bh(&pch->upl);
2043 }
2044 return unit;
2045 }
2046
2047 /*
2048 * Disconnect a channel from the generic layer.
2049 * This must be called in process context.
2050 */
2051 void
2052 ppp_unregister_channel(struct ppp_channel *chan)
2053 {
2054 struct channel *pch = chan->ppp;
2055
2056 if (pch == 0)
2057 return; /* should never happen */
2058 chan->ppp = NULL;
2059
2060 /*
2061 * This ensures that we have returned from any calls into the
2062 * the channel's start_xmit or ioctl routine before we proceed.
2063 */
2064 down_write(&pch->chan_sem);
2065 spin_lock_bh(&pch->downl);
2066 pch->chan = NULL;
2067 spin_unlock_bh(&pch->downl);
2068 up_write(&pch->chan_sem);
2069 ppp_disconnect_channel(pch);
2070 spin_lock_bh(&all_channels_lock);
2071 list_del(&pch->list);
2072 spin_unlock_bh(&all_channels_lock);
2073 pch->file.dead = 1;
2074 wake_up_interruptible(&pch->file.rwait);
2075 if (atomic_dec_and_test(&pch->file.refcnt))
2076 ppp_destroy_channel(pch);
2077 }
2078
2079 /*
2080 * Callback from a channel when it can accept more to transmit.
2081 * This should be called at BH/softirq level, not interrupt level.
2082 */
2083 void
2084 ppp_output_wakeup(struct ppp_channel *chan)
2085 {
2086 struct channel *pch = chan->ppp;
2087
2088 if (pch == 0)
2089 return;
2090 ppp_channel_push(pch);
2091 }
2092
2093 /*
2094 * Compression control.
2095 */
2096
2097 /* Process the PPPIOCSCOMPRESS ioctl. */
2098 static int
2099 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2100 {
2101 int err;
2102 struct compressor *cp, *ocomp;
2103 struct ppp_option_data data;
2104 void *state, *ostate;
2105 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2106
2107 err = -EFAULT;
2108 if (copy_from_user(&data, (void __user *) arg, sizeof(data))
2109 || (data.length <= CCP_MAX_OPTION_LENGTH
2110 && copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2111 goto out;
2112 err = -EINVAL;
2113 if (data.length > CCP_MAX_OPTION_LENGTH
2114 || ccp_option[1] < 2 || ccp_option[1] > data.length)
2115 goto out;
2116
2117 cp = find_compressor(ccp_option[0]);
2118 #ifdef CONFIG_KMOD
2119 if (cp == 0) {
2120 request_module("ppp-compress-%d", ccp_option[0]);
2121 cp = find_compressor(ccp_option[0]);
2122 }
2123 #endif /* CONFIG_KMOD */
2124 if (cp == 0)
2125 goto out;
2126
2127 err = -ENOBUFS;
2128 if (data.transmit) {
2129 state = cp->comp_alloc(ccp_option, data.length);
2130 if (state != 0) {
2131 ppp_xmit_lock(ppp);
2132 ppp->xstate &= ~SC_COMP_RUN;
2133 ocomp = ppp->xcomp;
2134 ostate = ppp->xc_state;
2135 ppp->xcomp = cp;
2136 ppp->xc_state = state;
2137 ppp_xmit_unlock(ppp);
2138 if (ostate != 0) {
2139 ocomp->comp_free(ostate);
2140 module_put(ocomp->owner);
2141 }
2142 err = 0;
2143 } else
2144 module_put(cp->owner);
2145
2146 } else {
2147 state = cp->decomp_alloc(ccp_option, data.length);
2148 if (state != 0) {
2149 ppp_recv_lock(ppp);
2150 ppp->rstate &= ~SC_DECOMP_RUN;
2151 ocomp = ppp->rcomp;
2152 ostate = ppp->rc_state;
2153 ppp->rcomp = cp;
2154 ppp->rc_state = state;
2155 ppp_recv_unlock(ppp);
2156 if (ostate != 0) {
2157 ocomp->decomp_free(ostate);
2158 module_put(ocomp->owner);
2159 }
2160 err = 0;
2161 } else
2162 module_put(cp->owner);
2163 }
2164
2165 out:
2166 return err;
2167 }
2168
2169 /*
2170 * Look at a CCP packet and update our state accordingly.
2171 * We assume the caller has the xmit or recv path locked.
2172 */
2173 static void
2174 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2175 {
2176 unsigned char *dp;
2177 int len;
2178
2179 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2180 return; /* no header */
2181 dp = skb->data + 2;
2182
2183 switch (CCP_CODE(dp)) {
2184 case CCP_CONFREQ:
2185
2186 /* A ConfReq starts negotiation of compression
2187 * in one direction of transmission,
2188 * and hence brings it down...but which way?
2189 *
2190 * Remember:
2191 * A ConfReq indicates what the sender would like to receive
2192 */
2193 if(inbound)
2194 /* He is proposing what I should send */
2195 ppp->xstate &= ~SC_COMP_RUN;
2196 else
2197 /* I am proposing to what he should send */
2198 ppp->rstate &= ~SC_DECOMP_RUN;
2199
2200 break;
2201
2202 case CCP_TERMREQ:
2203 case CCP_TERMACK:
2204 /*
2205 * CCP is going down, both directions of transmission
2206 */
2207 ppp->rstate &= ~SC_DECOMP_RUN;
2208 ppp->xstate &= ~SC_COMP_RUN;
2209 break;
2210
2211 case CCP_CONFACK:
2212 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2213 break;
2214 len = CCP_LENGTH(dp);
2215 if (!pskb_may_pull(skb, len + 2))
2216 return; /* too short */
2217 dp += CCP_HDRLEN;
2218 len -= CCP_HDRLEN;
2219 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2220 break;
2221 if (inbound) {
2222 /* we will start receiving compressed packets */
2223 if (ppp->rc_state == 0)
2224 break;
2225 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2226 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2227 ppp->rstate |= SC_DECOMP_RUN;
2228 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2229 }
2230 } else {
2231 /* we will soon start sending compressed packets */
2232 if (ppp->xc_state == 0)
2233 break;
2234 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2235 ppp->file.index, 0, ppp->debug))
2236 ppp->xstate |= SC_COMP_RUN;
2237 }
2238 break;
2239
2240 case CCP_RESETACK:
2241 /* reset the [de]compressor */
2242 if ((ppp->flags & SC_CCP_UP) == 0)
2243 break;
2244 if (inbound) {
2245 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2246 ppp->rcomp->decomp_reset(ppp->rc_state);
2247 ppp->rstate &= ~SC_DC_ERROR;
2248 }
2249 } else {
2250 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2251 ppp->xcomp->comp_reset(ppp->xc_state);
2252 }
2253 break;
2254 }
2255 }
2256
2257 /* Free up compression resources. */
2258 static void
2259 ppp_ccp_closed(struct ppp *ppp)
2260 {
2261 void *xstate, *rstate;
2262 struct compressor *xcomp, *rcomp;
2263
2264 ppp_lock(ppp);
2265 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2266 ppp->xstate = 0;
2267 xcomp = ppp->xcomp;
2268 xstate = ppp->xc_state;
2269 ppp->xc_state = NULL;
2270 ppp->rstate = 0;
2271 rcomp = ppp->rcomp;
2272 rstate = ppp->rc_state;
2273 ppp->rc_state = NULL;
2274 ppp_unlock(ppp);
2275
2276 if (xstate) {
2277 xcomp->comp_free(xstate);
2278 module_put(xcomp->owner);
2279 }
2280 if (rstate) {
2281 rcomp->decomp_free(rstate);
2282 module_put(rcomp->owner);
2283 }
2284 }
2285
2286 /* List of compressors. */
2287 static LIST_HEAD(compressor_list);
2288 static DEFINE_SPINLOCK(compressor_list_lock);
2289
2290 struct compressor_entry {
2291 struct list_head list;
2292 struct compressor *comp;
2293 };
2294
2295 static struct compressor_entry *
2296 find_comp_entry(int proto)
2297 {
2298 struct compressor_entry *ce;
2299
2300 list_for_each_entry(ce, &compressor_list, list) {
2301 if (ce->comp->compress_proto == proto)
2302 return ce;
2303 }
2304 return NULL;
2305 }
2306
2307 /* Register a compressor */
2308 int
2309 ppp_register_compressor(struct compressor *cp)
2310 {
2311 struct compressor_entry *ce;
2312 int ret;
2313 spin_lock(&compressor_list_lock);
2314 ret = -EEXIST;
2315 if (find_comp_entry(cp->compress_proto) != 0)
2316 goto out;
2317 ret = -ENOMEM;
2318 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2319 if (ce == 0)
2320 goto out;
2321 ret = 0;
2322 ce->comp = cp;
2323 list_add(&ce->list, &compressor_list);
2324 out:
2325 spin_unlock(&compressor_list_lock);
2326 return ret;
2327 }
2328
2329 /* Unregister a compressor */
2330 void
2331 ppp_unregister_compressor(struct compressor *cp)
2332 {
2333 struct compressor_entry *ce;
2334
2335 spin_lock(&compressor_list_lock);
2336 ce = find_comp_entry(cp->compress_proto);
2337 if (ce != 0 && ce->comp == cp) {
2338 list_del(&ce->list);
2339 kfree(ce);
2340 }
2341 spin_unlock(&compressor_list_lock);
2342 }
2343
2344 /* Find a compressor. */
2345 static struct compressor *
2346 find_compressor(int type)
2347 {
2348 struct compressor_entry *ce;
2349 struct compressor *cp = NULL;
2350
2351 spin_lock(&compressor_list_lock);
2352 ce = find_comp_entry(type);
2353 if (ce != 0) {
2354 cp = ce->comp;
2355 if (!try_module_get(cp->owner))
2356 cp = NULL;
2357 }
2358 spin_unlock(&compressor_list_lock);
2359 return cp;
2360 }
2361
2362 /*
2363 * Miscelleneous stuff.
2364 */
2365
2366 static void
2367 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2368 {
2369 struct slcompress *vj = ppp->vj;
2370
2371 memset(st, 0, sizeof(*st));
2372 st->p.ppp_ipackets = ppp->stats.rx_packets;
2373 st->p.ppp_ierrors = ppp->stats.rx_errors;
2374 st->p.ppp_ibytes = ppp->stats.rx_bytes;
2375 st->p.ppp_opackets = ppp->stats.tx_packets;
2376 st->p.ppp_oerrors = ppp->stats.tx_errors;
2377 st->p.ppp_obytes = ppp->stats.tx_bytes;
2378 if (vj == 0)
2379 return;
2380 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2381 st->vj.vjs_compressed = vj->sls_o_compressed;
2382 st->vj.vjs_searches = vj->sls_o_searches;
2383 st->vj.vjs_misses = vj->sls_o_misses;
2384 st->vj.vjs_errorin = vj->sls_i_error;
2385 st->vj.vjs_tossed = vj->sls_i_tossed;
2386 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2387 st->vj.vjs_compressedin = vj->sls_i_compressed;
2388 }
2389
2390 /*
2391 * Stuff for handling the lists of ppp units and channels
2392 * and for initialization.
2393 */
2394
2395 /*
2396 * Create a new ppp interface unit. Fails if it can't allocate memory
2397 * or if there is already a unit with the requested number.
2398 * unit == -1 means allocate a new number.
2399 */
2400 static struct ppp *
2401 ppp_create_interface(int unit, int *retp)
2402 {
2403 struct ppp *ppp;
2404 struct net_device *dev = NULL;
2405 int ret = -ENOMEM;
2406 int i;
2407
2408 ppp = kzalloc(sizeof(struct ppp), GFP_KERNEL);
2409 if (!ppp)
2410 goto out;
2411 dev = alloc_netdev(0, "", ppp_setup);
2412 if (!dev)
2413 goto out1;
2414
2415 ppp->mru = PPP_MRU;
2416 init_ppp_file(&ppp->file, INTERFACE);
2417 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2418 for (i = 0; i < NUM_NP; ++i)
2419 ppp->npmode[i] = NPMODE_PASS;
2420 INIT_LIST_HEAD(&ppp->channels);
2421 spin_lock_init(&ppp->rlock);
2422 spin_lock_init(&ppp->wlock);
2423 #ifdef CONFIG_PPP_MULTILINK
2424 ppp->minseq = -1;
2425 skb_queue_head_init(&ppp->mrq);
2426 #endif /* CONFIG_PPP_MULTILINK */
2427 ppp->dev = dev;
2428 dev->priv = ppp;
2429
2430 dev->hard_start_xmit = ppp_start_xmit;
2431 dev->get_stats = ppp_net_stats;
2432 dev->do_ioctl = ppp_net_ioctl;
2433
2434 ret = -EEXIST;
2435 mutex_lock(&all_ppp_mutex);
2436 if (unit < 0)
2437 unit = cardmap_find_first_free(all_ppp_units);
2438 else if (cardmap_get(all_ppp_units, unit) != NULL)
2439 goto out2; /* unit already exists */
2440
2441 /* Initialize the new ppp unit */
2442 ppp->file.index = unit;
2443 sprintf(dev->name, "ppp%d", unit);
2444
2445 ret = register_netdev(dev);
2446 if (ret != 0) {
2447 printk(KERN_ERR "PPP: couldn't register device %s (%d)\n",
2448 dev->name, ret);
2449 goto out2;
2450 }
2451
2452 atomic_inc(&ppp_unit_count);
2453 ret = cardmap_set(&all_ppp_units, unit, ppp);
2454 if (ret != 0)
2455 goto out3;
2456
2457 mutex_unlock(&all_ppp_mutex);
2458 *retp = 0;
2459 return ppp;
2460
2461 out3:
2462 atomic_dec(&ppp_unit_count);
2463 out2:
2464 mutex_unlock(&all_ppp_mutex);
2465 free_netdev(dev);
2466 out1:
2467 kfree(ppp);
2468 out:
2469 *retp = ret;
2470 return NULL;
2471 }
2472
2473 /*
2474 * Initialize a ppp_file structure.
2475 */
2476 static void
2477 init_ppp_file(struct ppp_file *pf, int kind)
2478 {
2479 pf->kind = kind;
2480 skb_queue_head_init(&pf->xq);
2481 skb_queue_head_init(&pf->rq);
2482 atomic_set(&pf->refcnt, 1);
2483 init_waitqueue_head(&pf->rwait);
2484 }
2485
2486 /*
2487 * Take down a ppp interface unit - called when the owning file
2488 * (the one that created the unit) is closed or detached.
2489 */
2490 static void ppp_shutdown_interface(struct ppp *ppp)
2491 {
2492 struct net_device *dev;
2493
2494 mutex_lock(&all_ppp_mutex);
2495 ppp_lock(ppp);
2496 dev = ppp->dev;
2497 ppp->dev = NULL;
2498 ppp_unlock(ppp);
2499 /* This will call dev_close() for us. */
2500 if (dev) {
2501 unregister_netdev(dev);
2502 free_netdev(dev);
2503 }
2504 cardmap_set(&all_ppp_units, ppp->file.index, NULL);
2505 ppp->file.dead = 1;
2506 ppp->owner = NULL;
2507 wake_up_interruptible(&ppp->file.rwait);
2508 mutex_unlock(&all_ppp_mutex);
2509 }
2510
2511 /*
2512 * Free the memory used by a ppp unit. This is only called once
2513 * there are no channels connected to the unit and no file structs
2514 * that reference the unit.
2515 */
2516 static void ppp_destroy_interface(struct ppp *ppp)
2517 {
2518 atomic_dec(&ppp_unit_count);
2519
2520 if (!ppp->file.dead || ppp->n_channels) {
2521 /* "can't happen" */
2522 printk(KERN_ERR "ppp: destroying ppp struct %p but dead=%d "
2523 "n_channels=%d !\n", ppp, ppp->file.dead,
2524 ppp->n_channels);
2525 return;
2526 }
2527
2528 ppp_ccp_closed(ppp);
2529 if (ppp->vj) {
2530 slhc_free(ppp->vj);
2531 ppp->vj = NULL;
2532 }
2533 skb_queue_purge(&ppp->file.xq);
2534 skb_queue_purge(&ppp->file.rq);
2535 #ifdef CONFIG_PPP_MULTILINK
2536 skb_queue_purge(&ppp->mrq);
2537 #endif /* CONFIG_PPP_MULTILINK */
2538 #ifdef CONFIG_PPP_FILTER
2539 kfree(ppp->pass_filter);
2540 ppp->pass_filter = NULL;
2541 kfree(ppp->active_filter);
2542 ppp->active_filter = NULL;
2543 #endif /* CONFIG_PPP_FILTER */
2544
2545 if (ppp->xmit_pending)
2546 kfree_skb(ppp->xmit_pending);
2547
2548 kfree(ppp);
2549 }
2550
2551 /*
2552 * Locate an existing ppp unit.
2553 * The caller should have locked the all_ppp_mutex.
2554 */
2555 static struct ppp *
2556 ppp_find_unit(int unit)
2557 {
2558 return cardmap_get(all_ppp_units, unit);
2559 }
2560
2561 /*
2562 * Locate an existing ppp channel.
2563 * The caller should have locked the all_channels_lock.
2564 * First we look in the new_channels list, then in the
2565 * all_channels list. If found in the new_channels list,
2566 * we move it to the all_channels list. This is for speed
2567 * when we have a lot of channels in use.
2568 */
2569 static struct channel *
2570 ppp_find_channel(int unit)
2571 {
2572 struct channel *pch;
2573
2574 list_for_each_entry(pch, &new_channels, list) {
2575 if (pch->file.index == unit) {
2576 list_move(&pch->list, &all_channels);
2577 return pch;
2578 }
2579 }
2580 list_for_each_entry(pch, &all_channels, list) {
2581 if (pch->file.index == unit)
2582 return pch;
2583 }
2584 return NULL;
2585 }
2586
2587 /*
2588 * Connect a PPP channel to a PPP interface unit.
2589 */
2590 static int
2591 ppp_connect_channel(struct channel *pch, int unit)
2592 {
2593 struct ppp *ppp;
2594 int ret = -ENXIO;
2595 int hdrlen;
2596
2597 mutex_lock(&all_ppp_mutex);
2598 ppp = ppp_find_unit(unit);
2599 if (ppp == 0)
2600 goto out;
2601 write_lock_bh(&pch->upl);
2602 ret = -EINVAL;
2603 if (pch->ppp != 0)
2604 goto outl;
2605
2606 ppp_lock(ppp);
2607 if (pch->file.hdrlen > ppp->file.hdrlen)
2608 ppp->file.hdrlen = pch->file.hdrlen;
2609 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2610 if (ppp->dev && hdrlen > ppp->dev->hard_header_len)
2611 ppp->dev->hard_header_len = hdrlen;
2612 list_add_tail(&pch->clist, &ppp->channels);
2613 ++ppp->n_channels;
2614 pch->ppp = ppp;
2615 atomic_inc(&ppp->file.refcnt);
2616 ppp_unlock(ppp);
2617 ret = 0;
2618
2619 outl:
2620 write_unlock_bh(&pch->upl);
2621 out:
2622 mutex_unlock(&all_ppp_mutex);
2623 return ret;
2624 }
2625
2626 /*
2627 * Disconnect a channel from its ppp unit.
2628 */
2629 static int
2630 ppp_disconnect_channel(struct channel *pch)
2631 {
2632 struct ppp *ppp;
2633 int err = -EINVAL;
2634
2635 write_lock_bh(&pch->upl);
2636 ppp = pch->ppp;
2637 pch->ppp = NULL;
2638 write_unlock_bh(&pch->upl);
2639 if (ppp != 0) {
2640 /* remove it from the ppp unit's list */
2641 ppp_lock(ppp);
2642 list_del(&pch->clist);
2643 if (--ppp->n_channels == 0)
2644 wake_up_interruptible(&ppp->file.rwait);
2645 ppp_unlock(ppp);
2646 if (atomic_dec_and_test(&ppp->file.refcnt))
2647 ppp_destroy_interface(ppp);
2648 err = 0;
2649 }
2650 return err;
2651 }
2652
2653 /*
2654 * Free up the resources used by a ppp channel.
2655 */
2656 static void ppp_destroy_channel(struct channel *pch)
2657 {
2658 atomic_dec(&channel_count);
2659
2660 if (!pch->file.dead) {
2661 /* "can't happen" */
2662 printk(KERN_ERR "ppp: destroying undead channel %p !\n",
2663 pch);
2664 return;
2665 }
2666 skb_queue_purge(&pch->file.xq);
2667 skb_queue_purge(&pch->file.rq);
2668 kfree(pch);
2669 }
2670
2671 static void __exit ppp_cleanup(void)
2672 {
2673 /* should never happen */
2674 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2675 printk(KERN_ERR "PPP: removing module but units remain!\n");
2676 cardmap_destroy(&all_ppp_units);
2677 if (unregister_chrdev(PPP_MAJOR, "ppp") != 0)
2678 printk(KERN_ERR "PPP: failed to unregister PPP device\n");
2679 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
2680 class_destroy(ppp_class);
2681 }
2682
2683 /*
2684 * Cardmap implementation.
2685 */
2686 static void *cardmap_get(struct cardmap *map, unsigned int nr)
2687 {
2688 struct cardmap *p;
2689 int i;
2690
2691 for (p = map; p != NULL; ) {
2692 if ((i = nr >> p->shift) >= CARDMAP_WIDTH)
2693 return NULL;
2694 if (p->shift == 0)
2695 return p->ptr[i];
2696 nr &= ~(CARDMAP_MASK << p->shift);
2697 p = p->ptr[i];
2698 }
2699 return NULL;
2700 }
2701
2702 static int cardmap_set(struct cardmap **pmap, unsigned int nr, void *ptr)
2703 {
2704 struct cardmap *p;
2705 int i;
2706
2707 p = *pmap;
2708 if (p == NULL || (nr >> p->shift) >= CARDMAP_WIDTH) {
2709 do {
2710 /* need a new top level */
2711 struct cardmap *np = kzalloc(sizeof(*np), GFP_KERNEL);
2712 if (!np)
2713 goto enomem;
2714 np->ptr[0] = p;
2715 if (p != NULL) {
2716 np->shift = p->shift + CARDMAP_ORDER;
2717 p->parent = np;
2718 } else
2719 np->shift = 0;
2720 p = np;
2721 } while ((nr >> p->shift) >= CARDMAP_WIDTH);
2722 *pmap = p;
2723 }
2724 while (p->shift > 0) {
2725 i = (nr >> p->shift) & CARDMAP_MASK;
2726 if (p->ptr[i] == NULL) {
2727 struct cardmap *np = kzalloc(sizeof(*np), GFP_KERNEL);
2728 if (!np)
2729 goto enomem;
2730 np->shift = p->shift - CARDMAP_ORDER;
2731 np->parent = p;
2732 p->ptr[i] = np;
2733 }
2734 if (ptr == NULL)
2735 clear_bit(i, &p->inuse);
2736 p = p->ptr[i];
2737 }
2738 i = nr & CARDMAP_MASK;
2739 p->ptr[i] = ptr;
2740 if (ptr != NULL)
2741 set_bit(i, &p->inuse);
2742 else
2743 clear_bit(i, &p->inuse);
2744 return 0;
2745 enomem:
2746 return -ENOMEM;
2747 }
2748
2749 static unsigned int cardmap_find_first_free(struct cardmap *map)
2750 {
2751 struct cardmap *p;
2752 unsigned int nr = 0;
2753 int i;
2754
2755 if ((p = map) == NULL)
2756 return 0;
2757 for (;;) {
2758 i = find_first_zero_bit(&p->inuse, CARDMAP_WIDTH);
2759 if (i >= CARDMAP_WIDTH) {
2760 if (p->parent == NULL)
2761 return CARDMAP_WIDTH << p->shift;
2762 p = p->parent;
2763 i = (nr >> p->shift) & CARDMAP_MASK;
2764 set_bit(i, &p->inuse);
2765 continue;
2766 }
2767 nr = (nr & (~CARDMAP_MASK << p->shift)) | (i << p->shift);
2768 if (p->shift == 0 || p->ptr[i] == NULL)
2769 return nr;
2770 p = p->ptr[i];
2771 }
2772 }
2773
2774 static void cardmap_destroy(struct cardmap **pmap)
2775 {
2776 struct cardmap *p, *np;
2777 int i;
2778
2779 for (p = *pmap; p != NULL; p = np) {
2780 if (p->shift != 0) {
2781 for (i = 0; i < CARDMAP_WIDTH; ++i)
2782 if (p->ptr[i] != NULL)
2783 break;
2784 if (i < CARDMAP_WIDTH) {
2785 np = p->ptr[i];
2786 p->ptr[i] = NULL;
2787 continue;
2788 }
2789 }
2790 np = p->parent;
2791 kfree(p);
2792 }
2793 *pmap = NULL;
2794 }
2795
2796 /* Module/initialization stuff */
2797
2798 module_init(ppp_init);
2799 module_exit(ppp_cleanup);
2800
2801 EXPORT_SYMBOL(ppp_register_channel);
2802 EXPORT_SYMBOL(ppp_unregister_channel);
2803 EXPORT_SYMBOL(ppp_channel_index);
2804 EXPORT_SYMBOL(ppp_unit_number);
2805 EXPORT_SYMBOL(ppp_input);
2806 EXPORT_SYMBOL(ppp_input_error);
2807 EXPORT_SYMBOL(ppp_output_wakeup);
2808 EXPORT_SYMBOL(ppp_register_compressor);
2809 EXPORT_SYMBOL(ppp_unregister_compressor);
2810 MODULE_LICENSE("GPL");
2811 MODULE_ALIAS_CHARDEV_MAJOR(PPP_MAJOR);
2812 MODULE_ALIAS("/dev/ppp");
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