?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
[PATCH] sem2mutex: drivers: raw, connector, dcdbas, ppp_generic
[usb.git] / drivers / net / ppp_generic.c
blobb2073fce82169fa41f97a4e21bf2dde453f3ccd4
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/config.h>
26 #include <linux/module.h>
27 #include <linux/kernel.h>
28 #include <linux/kmod.h>
29 #include <linux/init.h>
30 #include <linux/list.h>
31 #include <linux/devfs_fs_kernel.h>
32 #include <linux/netdevice.h>
33 #include <linux/poll.h>
34 #include <linux/ppp_defs.h>
35 #include <linux/filter.h>
36 #include <linux/if_ppp.h>
37 #include <linux/ppp_channel.h>
38 #include <linux/ppp-comp.h>
39 #include <linux/skbuff.h>
40 #include <linux/rtnetlink.h>
41 #include <linux/if_arp.h>
42 #include <linux/ip.h>
43 #include <linux/tcp.h>
44 #include <linux/spinlock.h>
45 #include <linux/smp_lock.h>
46 #include <linux/rwsem.h>
47 #include <linux/stddef.h>
48 #include <linux/device.h>
49 #include <linux/mutex.h>
50 #include <net/slhc_vj.h>
51 #include <asm/atomic.h>
52
53 #define PPP_VERSION "2.4.2"
54
55 /*
56 * Network protocols we support.
57 */
58 #define NP_IP 0 /* Internet Protocol V4 */
59 #define NP_IPV6 1 /* Internet Protocol V6 */
60 #define NP_IPX 2 /* IPX protocol */
61 #define NP_AT 3 /* Appletalk protocol */
62 #define NP_MPLS_UC 4 /* MPLS unicast */
63 #define NP_MPLS_MC 5 /* MPLS multicast */
64 #define NUM_NP 6 /* Number of NPs. */
65
66 #define MPHDRLEN 6 /* multilink protocol header length */
67 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */
68 #define MIN_FRAG_SIZE 64
69
70 /*
71 * An instance of /dev/ppp can be associated with either a ppp
72 * interface unit or a ppp channel. In both cases, file->private_data
73 * points to one of these.
74 */
75 struct ppp_file {
76 enum {
77 INTERFACE=1, CHANNEL
78 } kind;
79 struct sk_buff_head xq; /* pppd transmit queue */
80 struct sk_buff_head rq; /* receive queue for pppd */
81 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */
82 atomic_t refcnt; /* # refs (incl /dev/ppp attached) */
83 int hdrlen; /* space to leave for headers */
84 int index; /* interface unit / channel number */
85 int dead; /* unit/channel has been shut down */
86 };
87
88 #define PF_TO_X(pf, X) ((X *)((char *)(pf) - offsetof(X, file)))
89
90 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
91 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
92
93 #define ROUNDUP(n, x) (((n) + (x) - 1) / (x))
94
95 /*
96 * Data structure describing one ppp unit.
97 * A ppp unit corresponds to a ppp network interface device
98 * and represents a multilink bundle.
99 * It can have 0 or more ppp channels connected to it.
100 */
101 struct ppp {
102 struct ppp_file file; /* stuff for read/write/poll 0 */
103 struct file *owner; /* file that owns this unit 48 */
104 struct list_head channels; /* list of attached channels 4c */
105 int n_channels; /* how many channels are attached 54 */
106 spinlock_t rlock; /* lock for receive side 58 */
107 spinlock_t wlock; /* lock for transmit side 5c */
108 int mru; /* max receive unit 60 */
109 unsigned int flags; /* control bits 64 */
110 unsigned int xstate; /* transmit state bits 68 */
111 unsigned int rstate; /* receive state bits 6c */
112 int debug; /* debug flags 70 */
113 struct slcompress *vj; /* state for VJ header compression */
114 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
115 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
116 struct compressor *xcomp; /* transmit packet compressor 8c */
117 void *xc_state; /* its internal state 90 */
118 struct compressor *rcomp; /* receive decompressor 94 */
119 void *rc_state; /* its internal state 98 */
120 unsigned long last_xmit; /* jiffies when last pkt sent 9c */
121 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
122 struct net_device *dev; /* network interface device a4 */
123 #ifdef CONFIG_PPP_MULTILINK
124 int nxchan; /* next channel to send something on */
125 u32 nxseq; /* next sequence number to send */
126 int mrru; /* MP: max reconst. receive unit */
127 u32 nextseq; /* MP: seq no of next packet */
128 u32 minseq; /* MP: min of most recent seqnos */
129 struct sk_buff_head mrq; /* MP: receive reconstruction queue */
130 #endif /* CONFIG_PPP_MULTILINK */
131 struct net_device_stats stats; /* statistics */
132 #ifdef CONFIG_PPP_FILTER
133 struct sock_filter *pass_filter; /* filter for packets to pass */
134 struct sock_filter *active_filter;/* filter for pkts to reset idle */
135 unsigned pass_len, active_len;
136 #endif /* CONFIG_PPP_FILTER */
137 };
138
139 /*
140 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
141 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
142 * SC_MUST_COMP
143 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
144 * Bits in xstate: SC_COMP_RUN
145 */
146 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
147 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
148 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
149
150 /*
151 * Private data structure for each channel.
152 * This includes the data structure used for multilink.
153 */
154 struct channel {
155 struct ppp_file file; /* stuff for read/write/poll */
156 struct list_head list; /* link in all/new_channels list */
157 struct ppp_channel *chan; /* public channel data structure */
158 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
159 spinlock_t downl; /* protects `chan', file.xq dequeue */
160 struct ppp *ppp; /* ppp unit we're connected to */
161 struct list_head clist; /* link in list of channels per unit */
162 rwlock_t upl; /* protects `ppp' */
163 #ifdef CONFIG_PPP_MULTILINK
164 u8 avail; /* flag used in multilink stuff */
165 u8 had_frag; /* >= 1 fragments have been sent */
166 u32 lastseq; /* MP: last sequence # received */
167 #endif /* CONFIG_PPP_MULTILINK */
168 };
169
170 /*
171 * SMP locking issues:
172 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
173 * list and the ppp.n_channels field, you need to take both locks
174 * before you modify them.
175 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
176 * channel.downl.
177 */
178
179 /*
180 * A cardmap represents a mapping from unsigned integers to pointers,
181 * and provides a fast "find lowest unused number" operation.
182 * It uses a broad (32-way) tree with a bitmap at each level.
183 * It is designed to be space-efficient for small numbers of entries
184 * and time-efficient for large numbers of entries.
185 */
186 #define CARDMAP_ORDER 5
187 #define CARDMAP_WIDTH (1U << CARDMAP_ORDER)
188 #define CARDMAP_MASK (CARDMAP_WIDTH - 1)
189
190 struct cardmap {
191 int shift;
192 unsigned long inuse;
193 struct cardmap *parent;
194 void *ptr[CARDMAP_WIDTH];
195 };
196 static void *cardmap_get(struct cardmap *map, unsigned int nr);
197 static void cardmap_set(struct cardmap **map, unsigned int nr, void *ptr);
198 static unsigned int cardmap_find_first_free(struct cardmap *map);
199 static void cardmap_destroy(struct cardmap **map);
200
201 /*
202 * all_ppp_mutex protects the all_ppp_units mapping.
203 * It also ensures that finding a ppp unit in the all_ppp_units map
204 * and updating its file.refcnt field is atomic.
205 */
206 static DEFINE_MUTEX(all_ppp_mutex);
207 static struct cardmap *all_ppp_units;
208 static atomic_t ppp_unit_count = ATOMIC_INIT(0);
209
210 /*
211 * all_channels_lock protects all_channels and last_channel_index,
212 * and the atomicity of find a channel and updating its file.refcnt
213 * field.
214 */
215 static DEFINE_SPINLOCK(all_channels_lock);
216 static LIST_HEAD(all_channels);
217 static LIST_HEAD(new_channels);
218 static int last_channel_index;
219 static atomic_t channel_count = ATOMIC_INIT(0);
220
221 /* Get the PPP protocol number from a skb */
222 #define PPP_PROTO(skb) (((skb)->data[0] << 8) + (skb)->data[1])
223
224 /* We limit the length of ppp->file.rq to this (arbitrary) value */
225 #define PPP_MAX_RQLEN 32
226
227 /*
228 * Maximum number of multilink fragments queued up.
229 * This has to be large enough to cope with the maximum latency of
230 * the slowest channel relative to the others. Strictly it should
231 * depend on the number of channels and their characteristics.
232 */
233 #define PPP_MP_MAX_QLEN 128
234
235 /* Multilink header bits. */
236 #define B 0x80 /* this fragment begins a packet */
237 #define E 0x40 /* this fragment ends a packet */
238
239 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */
240 #define seq_before(a, b) ((s32)((a) - (b)) < 0)
241 #define seq_after(a, b) ((s32)((a) - (b)) > 0)
242
243 /* Prototypes. */
244 static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file,
245 unsigned int cmd, unsigned long arg);
246 static void ppp_xmit_process(struct ppp *ppp);
247 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
248 static void ppp_push(struct ppp *ppp);
249 static void ppp_channel_push(struct channel *pch);
250 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
251 struct channel *pch);
252 static void ppp_receive_error(struct ppp *ppp);
253 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
254 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
255 struct sk_buff *skb);
256 #ifdef CONFIG_PPP_MULTILINK
257 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
258 struct channel *pch);
259 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
260 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
261 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
262 #endif /* CONFIG_PPP_MULTILINK */
263 static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
264 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
265 static void ppp_ccp_closed(struct ppp *ppp);
266 static struct compressor *find_compressor(int type);
267 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
268 static struct ppp *ppp_create_interface(int unit, int *retp);
269 static void init_ppp_file(struct ppp_file *pf, int kind);
270 static void ppp_shutdown_interface(struct ppp *ppp);
271 static void ppp_destroy_interface(struct ppp *ppp);
272 static struct ppp *ppp_find_unit(int unit);
273 static struct channel *ppp_find_channel(int unit);
274 static int ppp_connect_channel(struct channel *pch, int unit);
275 static int ppp_disconnect_channel(struct channel *pch);
276 static void ppp_destroy_channel(struct channel *pch);
277
278 static struct class *ppp_class;
279
280 /* Translates a PPP protocol number to a NP index (NP == network protocol) */
281 static inline int proto_to_npindex(int proto)
282 {
283 switch (proto) {
284 case PPP_IP:
285 return NP_IP;
286 case PPP_IPV6:
287 return NP_IPV6;
288 case PPP_IPX:
289 return NP_IPX;
290 case PPP_AT:
291 return NP_AT;
292 case PPP_MPLS_UC:
293 return NP_MPLS_UC;
294 case PPP_MPLS_MC:
295 return NP_MPLS_MC;
296 }
297 return -EINVAL;
298 }
299
300 /* Translates an NP index into a PPP protocol number */
301 static const int npindex_to_proto[NUM_NP] = {
302 PPP_IP,
303 PPP_IPV6,
304 PPP_IPX,
305 PPP_AT,
306 PPP_MPLS_UC,
307 PPP_MPLS_MC,
308 };
309
310 /* Translates an ethertype into an NP index */
311 static inline int ethertype_to_npindex(int ethertype)
312 {
313 switch (ethertype) {
314 case ETH_P_IP:
315 return NP_IP;
316 case ETH_P_IPV6:
317 return NP_IPV6;
318 case ETH_P_IPX:
319 return NP_IPX;
320 case ETH_P_PPPTALK:
321 case ETH_P_ATALK:
322 return NP_AT;
323 case ETH_P_MPLS_UC:
324 return NP_MPLS_UC;
325 case ETH_P_MPLS_MC:
326 return NP_MPLS_MC;
327 }
328 return -1;
329 }
330
331 /* Translates an NP index into an ethertype */
332 static const int npindex_to_ethertype[NUM_NP] = {
333 ETH_P_IP,
334 ETH_P_IPV6,
335 ETH_P_IPX,
336 ETH_P_PPPTALK,
337 ETH_P_MPLS_UC,
338 ETH_P_MPLS_MC,
339 };
340
341 /*
342 * Locking shorthand.
343 */
344 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
345 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
346 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
347 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
348 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
349 ppp_recv_lock(ppp); } while (0)
350 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
351 ppp_xmit_unlock(ppp); } while (0)
352
353 /*
354 * /dev/ppp device routines.
355 * The /dev/ppp device is used by pppd to control the ppp unit.
356 * It supports the read, write, ioctl and poll functions.
357 * Open instances of /dev/ppp can be in one of three states:
358 * unattached, attached to a ppp unit, or attached to a ppp channel.
359 */
360 static int ppp_open(struct inode *inode, struct file *file)
361 {
362 /*
363 * This could (should?) be enforced by the permissions on /dev/ppp.
364 */
365 if (!capable(CAP_NET_ADMIN))
366 return -EPERM;
367 return 0;
368 }
369
370 static int ppp_release(struct inode *inode, struct file *file)
371 {
372 struct ppp_file *pf = file->private_data;
373 struct ppp *ppp;
374
375 if (pf != 0) {
376 file->private_data = NULL;
377 if (pf->kind == INTERFACE) {
378 ppp = PF_TO_PPP(pf);
379 if (file == ppp->owner)
380 ppp_shutdown_interface(ppp);
381 }
382 if (atomic_dec_and_test(&pf->refcnt)) {
383 switch (pf->kind) {
384 case INTERFACE:
385 ppp_destroy_interface(PF_TO_PPP(pf));
386 break;
387 case CHANNEL:
388 ppp_destroy_channel(PF_TO_CHANNEL(pf));
389 break;
390 }
391 }
392 }
393 return 0;
394 }
395
396 static ssize_t ppp_read(struct file *file, char __user *buf,
397 size_t count, loff_t *ppos)
398 {
399 struct ppp_file *pf = file->private_data;
400 DECLARE_WAITQUEUE(wait, current);
401 ssize_t ret;
402 struct sk_buff *skb = NULL;
403
404 ret = count;
405
406 if (pf == 0)
407 return -ENXIO;
408 add_wait_queue(&pf->rwait, &wait);
409 for (;;) {
410 set_current_state(TASK_INTERRUPTIBLE);
411 skb = skb_dequeue(&pf->rq);
412 if (skb)
413 break;
414 ret = 0;
415 if (pf->dead)
416 break;
417 if (pf->kind == INTERFACE) {
418 /*
419 * Return 0 (EOF) on an interface that has no
420 * channels connected, unless it is looping
421 * network traffic (demand mode).
422 */
423 struct ppp *ppp = PF_TO_PPP(pf);
424 if (ppp->n_channels == 0
425 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
426 break;
427 }
428 ret = -EAGAIN;
429 if (file->f_flags & O_NONBLOCK)
430 break;
431 ret = -ERESTARTSYS;
432 if (signal_pending(current))
433 break;
434 schedule();
435 }
436 set_current_state(TASK_RUNNING);
437 remove_wait_queue(&pf->rwait, &wait);
438
439 if (skb == 0)
440 goto out;
441
442 ret = -EOVERFLOW;
443 if (skb->len > count)
444 goto outf;
445 ret = -EFAULT;
446 if (copy_to_user(buf, skb->data, skb->len))
447 goto outf;
448 ret = skb->len;
449
450 outf:
451 kfree_skb(skb);
452 out:
453 return ret;
454 }
455
456 static ssize_t ppp_write(struct file *file, const char __user *buf,
457 size_t count, loff_t *ppos)
458 {
459 struct ppp_file *pf = file->private_data;
460 struct sk_buff *skb;
461 ssize_t ret;
462
463 if (pf == 0)
464 return -ENXIO;
465 ret = -ENOMEM;
466 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
467 if (skb == 0)
468 goto out;
469 skb_reserve(skb, pf->hdrlen);
470 ret = -EFAULT;
471 if (copy_from_user(skb_put(skb, count), buf, count)) {
472 kfree_skb(skb);
473 goto out;
474 }
475
476 skb_queue_tail(&pf->xq, skb);
477
478 switch (pf->kind) {
479 case INTERFACE:
480 ppp_xmit_process(PF_TO_PPP(pf));
481 break;
482 case CHANNEL:
483 ppp_channel_push(PF_TO_CHANNEL(pf));
484 break;
485 }
486
487 ret = count;
488
489 out:
490 return ret;
491 }
492
493 /* No kernel lock - fine */
494 static unsigned int ppp_poll(struct file *file, poll_table *wait)
495 {
496 struct ppp_file *pf = file->private_data;
497 unsigned int mask;
498
499 if (pf == 0)
500 return 0;
501 poll_wait(file, &pf->rwait, wait);
502 mask = POLLOUT | POLLWRNORM;
503 if (skb_peek(&pf->rq) != 0)
504 mask |= POLLIN | POLLRDNORM;
505 if (pf->dead)
506 mask |= POLLHUP;
507 else if (pf->kind == INTERFACE) {
508 /* see comment in ppp_read */
509 struct ppp *ppp = PF_TO_PPP(pf);
510 if (ppp->n_channels == 0
511 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
512 mask |= POLLIN | POLLRDNORM;
513 }
514
515 return mask;
516 }
517
518 #ifdef CONFIG_PPP_FILTER
519 static int get_filter(void __user *arg, struct sock_filter **p)
520 {
521 struct sock_fprog uprog;
522 struct sock_filter *code = NULL;
523 int len, err;
524
525 if (copy_from_user(&uprog, arg, sizeof(uprog)))
526 return -EFAULT;
527
528 if (!uprog.len) {
529 *p = NULL;
530 return 0;
531 }
532
533 len = uprog.len * sizeof(struct sock_filter);
534 code = kmalloc(len, GFP_KERNEL);
535 if (code == NULL)
536 return -ENOMEM;
537
538 if (copy_from_user(code, uprog.filter, len)) {
539 kfree(code);
540 return -EFAULT;
541 }
542
543 err = sk_chk_filter(code, uprog.len);
544 if (err) {
545 kfree(code);
546 return err;
547 }
548
549 *p = code;
550 return uprog.len;
551 }
552 #endif /* CONFIG_PPP_FILTER */
553
554 static int ppp_ioctl(struct inode *inode, struct file *file,
555 unsigned int cmd, unsigned long arg)
556 {
557 struct ppp_file *pf = file->private_data;
558 struct ppp *ppp;
559 int err = -EFAULT, val, val2, i;
560 struct ppp_idle idle;
561 struct npioctl npi;
562 int unit, cflags;
563 struct slcompress *vj;
564 void __user *argp = (void __user *)arg;
565 int __user *p = argp;
566
567 if (pf == 0)
568 return ppp_unattached_ioctl(pf, file, cmd, arg);
569
570 if (cmd == PPPIOCDETACH) {
571 /*
572 * We have to be careful here... if the file descriptor
573 * has been dup'd, we could have another process in the
574 * middle of a poll using the same file *, so we had
575 * better not free the interface data structures -
576 * instead we fail the ioctl. Even in this case, we
577 * shut down the interface if we are the owner of it.
578 * Actually, we should get rid of PPPIOCDETACH, userland
579 * (i.e. pppd) could achieve the same effect by closing
580 * this fd and reopening /dev/ppp.
581 */
582 err = -EINVAL;
583 if (pf->kind == INTERFACE) {
584 ppp = PF_TO_PPP(pf);
585 if (file == ppp->owner)
586 ppp_shutdown_interface(ppp);
587 }
588 if (atomic_read(&file->f_count) <= 2) {
589 ppp_release(inode, file);
590 err = 0;
591 } else
592 printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%d\n",
593 atomic_read(&file->f_count));
594 return err;
595 }
596
597 if (pf->kind == CHANNEL) {
598 struct channel *pch = PF_TO_CHANNEL(pf);
599 struct ppp_channel *chan;
600
601 switch (cmd) {
602 case PPPIOCCONNECT:
603 if (get_user(unit, p))
604 break;
605 err = ppp_connect_channel(pch, unit);
606 break;
607
608 case PPPIOCDISCONN:
609 err = ppp_disconnect_channel(pch);
610 break;
611
612 default:
613 down_read(&pch->chan_sem);
614 chan = pch->chan;
615 err = -ENOTTY;
616 if (chan && chan->ops->ioctl)
617 err = chan->ops->ioctl(chan, cmd, arg);
618 up_read(&pch->chan_sem);
619 }
620 return err;
621 }
622
623 if (pf->kind != INTERFACE) {
624 /* can't happen */
625 printk(KERN_ERR "PPP: not interface or channel??\n");
626 return -EINVAL;
627 }
628
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 == 0) {
698 printk(KERN_ERR "PPP: no memory (VJ compressor)\n");
699 err = -ENOMEM;
700 break;
701 }
702 ppp_lock(ppp);
703 if (ppp->vj != 0)
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
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 switch (cmd) {
789 case PPPIOCNEWUNIT:
790 /* Create a new ppp unit */
791 if (get_user(unit, p))
792 break;
793 ppp = ppp_create_interface(unit, &err);
794 if (ppp == 0)
795 break;
796 file->private_data = &ppp->file;
797 ppp->owner = file;
798 err = -EFAULT;
799 if (put_user(ppp->file.index, p))
800 break;
801 err = 0;
802 break;
803
804 case PPPIOCATTACH:
805 /* Attach to an existing ppp unit */
806 if (get_user(unit, p))
807 break;
808 mutex_lock(&all_ppp_mutex);
809 err = -ENXIO;
810 ppp = ppp_find_unit(unit);
811 if (ppp != 0) {
812 atomic_inc(&ppp->file.refcnt);
813 file->private_data = &ppp->file;
814 err = 0;
815 }
816 mutex_unlock(&all_ppp_mutex);
817 break;
818
819 case PPPIOCATTCHAN:
820 if (get_user(unit, p))
821 break;
822 spin_lock_bh(&all_channels_lock);
823 err = -ENXIO;
824 chan = ppp_find_channel(unit);
825 if (chan != 0) {
826 atomic_inc(&chan->file.refcnt);
827 file->private_data = &chan->file;
828 err = 0;
829 }
830 spin_unlock_bh(&all_channels_lock);
831 break;
832
833 default:
834 err = -ENOTTY;
835 }
836 return err;
837 }
838
839 static struct file_operations ppp_device_fops = {
840 .owner = THIS_MODULE,
841 .read = ppp_read,
842 .write = ppp_write,
843 .poll = ppp_poll,
844 .ioctl = ppp_ioctl,
845 .open = ppp_open,
846 .release = ppp_release
847 };
848
849 #define PPP_MAJOR 108
850
851 /* Called at boot time if ppp is compiled into the kernel,
852 or at module load time (from init_module) if compiled as a module. */
853 static int __init ppp_init(void)
854 {
855 int err;
856
857 printk(KERN_INFO "PPP generic driver version " PPP_VERSION "\n");
858 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
859 if (!err) {
860 ppp_class = class_create(THIS_MODULE, "ppp");
861 if (IS_ERR(ppp_class)) {
862 err = PTR_ERR(ppp_class);
863 goto out_chrdev;
864 }
865 class_device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
866 err = devfs_mk_cdev(MKDEV(PPP_MAJOR, 0),
867 S_IFCHR|S_IRUSR|S_IWUSR, "ppp");
868 if (err)
869 goto out_class;
870 }
871
872 out:
873 if (err)
874 printk(KERN_ERR "failed to register PPP device (%d)\n", err);
875 return err;
876
877 out_class:
878 class_device_destroy(ppp_class, MKDEV(PPP_MAJOR,0));
879 class_destroy(ppp_class);
880 out_chrdev:
881 unregister_chrdev(PPP_MAJOR, "ppp");
882 goto out;
883 }
884
885 /*
886 * Network interface unit routines.
887 */
888 static int
889 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
890 {
891 struct ppp *ppp = (struct ppp *) dev->priv;
892 int npi, proto;
893 unsigned char *pp;
894
895 npi = ethertype_to_npindex(ntohs(skb->protocol));
896 if (npi < 0)
897 goto outf;
898
899 /* Drop, accept or reject the packet */
900 switch (ppp->npmode[npi]) {
901 case NPMODE_PASS:
902 break;
903 case NPMODE_QUEUE:
904 /* it would be nice to have a way to tell the network
905 system to queue this one up for later. */
906 goto outf;
907 case NPMODE_DROP:
908 case NPMODE_ERROR:
909 goto outf;
910 }
911
912 /* Put the 2-byte PPP protocol number on the front,
913 making sure there is room for the address and control fields. */
914 if (skb_headroom(skb) < PPP_HDRLEN) {
915 struct sk_buff *ns;
916
917 ns = alloc_skb(skb->len + dev->hard_header_len, GFP_ATOMIC);
918 if (ns == 0)
919 goto outf;
920 skb_reserve(ns, dev->hard_header_len);
921 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
922 kfree_skb(skb);
923 skb = ns;
924 }
925 pp = skb_push(skb, 2);
926 proto = npindex_to_proto[npi];
927 pp[0] = proto >> 8;
928 pp[1] = proto;
929
930 netif_stop_queue(dev);
931 skb_queue_tail(&ppp->file.xq, skb);
932 ppp_xmit_process(ppp);
933 return 0;
934
935 outf:
936 kfree_skb(skb);
937 ++ppp->stats.tx_dropped;
938 return 0;
939 }
940
941 static struct net_device_stats *
942 ppp_net_stats(struct net_device *dev)
943 {
944 struct ppp *ppp = (struct ppp *) dev->priv;
945
946 return &ppp->stats;
947 }
948
949 static int
950 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
951 {
952 struct ppp *ppp = dev->priv;
953 int err = -EFAULT;
954 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
955 struct ppp_stats stats;
956 struct ppp_comp_stats cstats;
957 char *vers;
958
959 switch (cmd) {
960 case SIOCGPPPSTATS:
961 ppp_get_stats(ppp, &stats);
962 if (copy_to_user(addr, &stats, sizeof(stats)))
963 break;
964 err = 0;
965 break;
966
967 case SIOCGPPPCSTATS:
968 memset(&cstats, 0, sizeof(cstats));
969 if (ppp->xc_state != 0)
970 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
971 if (ppp->rc_state != 0)
972 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
973 if (copy_to_user(addr, &cstats, sizeof(cstats)))
974 break;
975 err = 0;
976 break;
977
978 case SIOCGPPPVER:
979 vers = PPP_VERSION;
980 if (copy_to_user(addr, vers, strlen(vers) + 1))
981 break;
982 err = 0;
983 break;
984
985 default:
986 err = -EINVAL;
987 }
988
989 return err;
990 }
991
992 static void ppp_setup(struct net_device *dev)
993 {
994 dev->hard_header_len = PPP_HDRLEN;
995 dev->mtu = PPP_MTU;
996 dev->addr_len = 0;
997 dev->tx_queue_len = 3;
998 dev->type = ARPHRD_PPP;
999 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1000 }
1001
1002 /*
1003 * Transmit-side routines.
1004 */
1005
1006 /*
1007 * Called to do any work queued up on the transmit side
1008 * that can now be done.
1009 */
1010 static void
1011 ppp_xmit_process(struct ppp *ppp)
1012 {
1013 struct sk_buff *skb;
1014
1015 ppp_xmit_lock(ppp);
1016 if (ppp->dev != 0) {
1017 ppp_push(ppp);
1018 while (ppp->xmit_pending == 0
1019 && (skb = skb_dequeue(&ppp->file.xq)) != 0)
1020 ppp_send_frame(ppp, skb);
1021 /* If there's no work left to do, tell the core net
1022 code that we can accept some more. */
1023 if (ppp->xmit_pending == 0 && skb_peek(&ppp->file.xq) == 0)
1024 netif_wake_queue(ppp->dev);
1025 }
1026 ppp_xmit_unlock(ppp);
1027 }
1028
1029 static inline struct sk_buff *
1030 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1031 {
1032 struct sk_buff *new_skb;
1033 int len;
1034 int new_skb_size = ppp->dev->mtu +
1035 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1036 int compressor_skb_size = ppp->dev->mtu +
1037 ppp->xcomp->comp_extra + PPP_HDRLEN;
1038 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1039 if (!new_skb) {
1040 if (net_ratelimit())
1041 printk(KERN_ERR "PPP: no memory (comp pkt)\n");
1042 return NULL;
1043 }
1044 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1045 skb_reserve(new_skb,
1046 ppp->dev->hard_header_len - PPP_HDRLEN);
1047
1048 /* compressor still expects A/C bytes in hdr */
1049 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1050 new_skb->data, skb->len + 2,
1051 compressor_skb_size);
1052 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1053 kfree_skb(skb);
1054 skb = new_skb;
1055 skb_put(skb, len);
1056 skb_pull(skb, 2); /* pull off A/C bytes */
1057 } else if (len == 0) {
1058 /* didn't compress, or CCP not up yet */
1059 kfree_skb(new_skb);
1060 new_skb = skb;
1061 } else {
1062 /*
1063 * (len < 0)
1064 * MPPE requires that we do not send unencrypted
1065 * frames. The compressor will return -1 if we
1066 * should drop the frame. We cannot simply test
1067 * the compress_proto because MPPE and MPPC share
1068 * the same number.
1069 */
1070 if (net_ratelimit())
1071 printk(KERN_ERR "ppp: compressor dropped pkt\n");
1072 kfree_skb(skb);
1073 kfree_skb(new_skb);
1074 new_skb = NULL;
1075 }
1076 return new_skb;
1077 }
1078
1079 /*
1080 * Compress and send a frame.
1081 * The caller should have locked the xmit path,
1082 * and xmit_pending should be 0.
1083 */
1084 static void
1085 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1086 {
1087 int proto = PPP_PROTO(skb);
1088 struct sk_buff *new_skb;
1089 int len;
1090 unsigned char *cp;
1091
1092 if (proto < 0x8000) {
1093 #ifdef CONFIG_PPP_FILTER
1094 /* check if we should pass this packet */
1095 /* the filter instructions are constructed assuming
1096 a four-byte PPP header on each packet */
1097 *skb_push(skb, 2) = 1;
1098 if (ppp->pass_filter
1099 && sk_run_filter(skb, ppp->pass_filter,
1100 ppp->pass_len) == 0) {
1101 if (ppp->debug & 1)
1102 printk(KERN_DEBUG "PPP: outbound frame not passed\n");
1103 kfree_skb(skb);
1104 return;
1105 }
1106 /* if this packet passes the active filter, record the time */
1107 if (!(ppp->active_filter
1108 && sk_run_filter(skb, ppp->active_filter,
1109 ppp->active_len) == 0))
1110 ppp->last_xmit = jiffies;
1111 skb_pull(skb, 2);
1112 #else
1113 /* for data packets, record the time */
1114 ppp->last_xmit = jiffies;
1115 #endif /* CONFIG_PPP_FILTER */
1116 }
1117
1118 ++ppp->stats.tx_packets;
1119 ppp->stats.tx_bytes += skb->len - 2;
1120
1121 switch (proto) {
1122 case PPP_IP:
1123 if (ppp->vj == 0 || (ppp->flags & SC_COMP_TCP) == 0)
1124 break;
1125 /* try to do VJ TCP header compression */
1126 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1127 GFP_ATOMIC);
1128 if (new_skb == 0) {
1129 printk(KERN_ERR "PPP: no memory (VJ comp pkt)\n");
1130 goto drop;
1131 }
1132 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1133 cp = skb->data + 2;
1134 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1135 new_skb->data + 2, &cp,
1136 !(ppp->flags & SC_NO_TCP_CCID));
1137 if (cp == skb->data + 2) {
1138 /* didn't compress */
1139 kfree_skb(new_skb);
1140 } else {
1141 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1142 proto = PPP_VJC_COMP;
1143 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1144 } else {
1145 proto = PPP_VJC_UNCOMP;
1146 cp[0] = skb->data[2];
1147 }
1148 kfree_skb(skb);
1149 skb = new_skb;
1150 cp = skb_put(skb, len + 2);
1151 cp[0] = 0;
1152 cp[1] = proto;
1153 }
1154 break;
1155
1156 case PPP_CCP:
1157 /* peek at outbound CCP frames */
1158 ppp_ccp_peek(ppp, skb, 0);
1159 break;
1160 }
1161
1162 /* try to do packet compression */
1163 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state != 0
1164 && proto != PPP_LCP && proto != PPP_CCP) {
1165 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1166 if (net_ratelimit())
1167 printk(KERN_ERR "ppp: compression required but down - pkt dropped.\n");
1168 goto drop;
1169 }
1170 skb = pad_compress_skb(ppp, skb);
1171 if (!skb)
1172 goto drop;
1173 }
1174
1175 /*
1176 * If we are waiting for traffic (demand dialling),
1177 * queue it up for pppd to receive.
1178 */
1179 if (ppp->flags & SC_LOOP_TRAFFIC) {
1180 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1181 goto drop;
1182 skb_queue_tail(&ppp->file.rq, skb);
1183 wake_up_interruptible(&ppp->file.rwait);
1184 return;
1185 }
1186
1187 ppp->xmit_pending = skb;
1188 ppp_push(ppp);
1189 return;
1190
1191 drop:
1192 if (skb)
1193 kfree_skb(skb);
1194 ++ppp->stats.tx_errors;
1195 }
1196
1197 /*
1198 * Try to send the frame in xmit_pending.
1199 * The caller should have the xmit path locked.
1200 */
1201 static void
1202 ppp_push(struct ppp *ppp)
1203 {
1204 struct list_head *list;
1205 struct channel *pch;
1206 struct sk_buff *skb = ppp->xmit_pending;
1207
1208 if (skb == 0)
1209 return;
1210
1211 list = &ppp->channels;
1212 if (list_empty(list)) {
1213 /* nowhere to send the packet, just drop it */
1214 ppp->xmit_pending = NULL;
1215 kfree_skb(skb);
1216 return;
1217 }
1218
1219 if ((ppp->flags & SC_MULTILINK) == 0) {
1220 /* not doing multilink: send it down the first channel */
1221 list = list->next;
1222 pch = list_entry(list, struct channel, clist);
1223
1224 spin_lock_bh(&pch->downl);
1225 if (pch->chan) {
1226 if (pch->chan->ops->start_xmit(pch->chan, skb))
1227 ppp->xmit_pending = NULL;
1228 } else {
1229 /* channel got unregistered */
1230 kfree_skb(skb);
1231 ppp->xmit_pending = NULL;
1232 }
1233 spin_unlock_bh(&pch->downl);
1234 return;
1235 }
1236
1237 #ifdef CONFIG_PPP_MULTILINK
1238 /* Multilink: fragment the packet over as many links
1239 as can take the packet at the moment. */
1240 if (!ppp_mp_explode(ppp, skb))
1241 return;
1242 #endif /* CONFIG_PPP_MULTILINK */
1243
1244 ppp->xmit_pending = NULL;
1245 kfree_skb(skb);
1246 }
1247
1248 #ifdef CONFIG_PPP_MULTILINK
1249 /*
1250 * Divide a packet to be transmitted into fragments and
1251 * send them out the individual links.
1252 */
1253 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1254 {
1255 int len, fragsize;
1256 int i, bits, hdrlen, mtu;
1257 int flen;
1258 int navail, nfree;
1259 int nbigger;
1260 unsigned char *p, *q;
1261 struct list_head *list;
1262 struct channel *pch;
1263 struct sk_buff *frag;
1264 struct ppp_channel *chan;
1265
1266 nfree = 0; /* # channels which have no packet already queued */
1267 navail = 0; /* total # of usable channels (not deregistered) */
1268 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1269 i = 0;
1270 list_for_each_entry(pch, &ppp->channels, clist) {
1271 navail += pch->avail = (pch->chan != NULL);
1272 if (pch->avail) {
1273 if (skb_queue_empty(&pch->file.xq) ||
1274 !pch->had_frag) {
1275 pch->avail = 2;
1276 ++nfree;
1277 }
1278 if (!pch->had_frag && i < ppp->nxchan)
1279 ppp->nxchan = i;
1280 }
1281 ++i;
1282 }
1283
1284 /*
1285 * Don't start sending this packet unless at least half of
1286 * the channels are free. This gives much better TCP
1287 * performance if we have a lot of channels.
1288 */
1289 if (nfree == 0 || nfree < navail / 2)
1290 return 0; /* can't take now, leave it in xmit_pending */
1291
1292 /* Do protocol field compression (XXX this should be optional) */
1293 p = skb->data;
1294 len = skb->len;
1295 if (*p == 0) {
1296 ++p;
1297 --len;
1298 }
1299
1300 /*
1301 * Decide on fragment size.
1302 * We create a fragment for each free channel regardless of
1303 * how small they are (i.e. even 0 length) in order to minimize
1304 * the time that it will take to detect when a channel drops
1305 * a fragment.
1306 */
1307 fragsize = len;
1308 if (nfree > 1)
1309 fragsize = ROUNDUP(fragsize, nfree);
1310 /* nbigger channels get fragsize bytes, the rest get fragsize-1,
1311 except if nbigger==0, then they all get fragsize. */
1312 nbigger = len % nfree;
1313
1314 /* skip to the channel after the one we last used
1315 and start at that one */
1316 list = &ppp->channels;
1317 for (i = 0; i < ppp->nxchan; ++i) {
1318 list = list->next;
1319 if (list == &ppp->channels) {
1320 i = 0;
1321 break;
1322 }
1323 }
1324
1325 /* create a fragment for each channel */
1326 bits = B;
1327 while (nfree > 0 || len > 0) {
1328 list = list->next;
1329 if (list == &ppp->channels) {
1330 i = 0;
1331 continue;
1332 }
1333 pch = list_entry(list, struct channel, clist);
1334 ++i;
1335 if (!pch->avail)
1336 continue;
1337
1338 /*
1339 * Skip this channel if it has a fragment pending already and
1340 * we haven't given a fragment to all of the free channels.
1341 */
1342 if (pch->avail == 1) {
1343 if (nfree > 0)
1344 continue;
1345 } else {
1346 --nfree;
1347 pch->avail = 1;
1348 }
1349
1350 /* check the channel's mtu and whether it is still attached. */
1351 spin_lock_bh(&pch->downl);
1352 if (pch->chan == NULL) {
1353 /* can't use this channel, it's being deregistered */
1354 spin_unlock_bh(&pch->downl);
1355 pch->avail = 0;
1356 if (--navail == 0)
1357 break;
1358 continue;
1359 }
1360
1361 /*
1362 * Create a fragment for this channel of
1363 * min(max(mtu+2-hdrlen, 4), fragsize, len) bytes.
1364 * If mtu+2-hdrlen < 4, that is a ridiculously small
1365 * MTU, so we use mtu = 2 + hdrlen.
1366 */
1367 if (fragsize > len)
1368 fragsize = len;
1369 flen = fragsize;
1370 mtu = pch->chan->mtu + 2 - hdrlen;
1371 if (mtu < 4)
1372 mtu = 4;
1373 if (flen > mtu)
1374 flen = mtu;
1375 if (flen == len && nfree == 0)
1376 bits |= E;
1377 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1378 if (frag == 0)
1379 goto noskb;
1380 q = skb_put(frag, flen + hdrlen);
1381
1382 /* make the MP header */
1383 q[0] = PPP_MP >> 8;
1384 q[1] = PPP_MP;
1385 if (ppp->flags & SC_MP_XSHORTSEQ) {
1386 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1387 q[3] = ppp->nxseq;
1388 } else {
1389 q[2] = bits;
1390 q[3] = ppp->nxseq >> 16;
1391 q[4] = ppp->nxseq >> 8;
1392 q[5] = ppp->nxseq;
1393 }
1394
1395 /*
1396 * Copy the data in.
1397 * Unfortunately there is a bug in older versions of
1398 * the Linux PPP multilink reconstruction code where it
1399 * drops 0-length fragments. Therefore we make sure the
1400 * fragment has at least one byte of data. Any bytes
1401 * we add in this situation will end up as padding on the
1402 * end of the reconstructed packet.
1403 */
1404 if (flen == 0)
1405 *skb_put(frag, 1) = 0;
1406 else
1407 memcpy(q + hdrlen, p, flen);
1408
1409 /* try to send it down the channel */
1410 chan = pch->chan;
1411 if (!skb_queue_empty(&pch->file.xq) ||
1412 !chan->ops->start_xmit(chan, frag))
1413 skb_queue_tail(&pch->file.xq, frag);
1414 pch->had_frag = 1;
1415 p += flen;
1416 len -= flen;
1417 ++ppp->nxseq;
1418 bits = 0;
1419 spin_unlock_bh(&pch->downl);
1420
1421 if (--nbigger == 0 && fragsize > 0)
1422 --fragsize;
1423 }
1424 ppp->nxchan = i;
1425
1426 return 1;
1427
1428 noskb:
1429 spin_unlock_bh(&pch->downl);
1430 if (ppp->debug & 1)
1431 printk(KERN_ERR "PPP: no memory (fragment)\n");
1432 ++ppp->stats.tx_errors;
1433 ++ppp->nxseq;
1434 return 1; /* abandon the frame */
1435 }
1436 #endif /* CONFIG_PPP_MULTILINK */
1437
1438 /*
1439 * Try to send data out on a channel.
1440 */
1441 static void
1442 ppp_channel_push(struct channel *pch)
1443 {
1444 struct sk_buff *skb;
1445 struct ppp *ppp;
1446
1447 spin_lock_bh(&pch->downl);
1448 if (pch->chan != 0) {
1449 while (!skb_queue_empty(&pch->file.xq)) {
1450 skb = skb_dequeue(&pch->file.xq);
1451 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1452 /* put the packet back and try again later */
1453 skb_queue_head(&pch->file.xq, skb);
1454 break;
1455 }
1456 }
1457 } else {
1458 /* channel got deregistered */
1459 skb_queue_purge(&pch->file.xq);
1460 }
1461 spin_unlock_bh(&pch->downl);
1462 /* see if there is anything from the attached unit to be sent */
1463 if (skb_queue_empty(&pch->file.xq)) {
1464 read_lock_bh(&pch->upl);
1465 ppp = pch->ppp;
1466 if (ppp != 0)
1467 ppp_xmit_process(ppp);
1468 read_unlock_bh(&pch->upl);
1469 }
1470 }
1471
1472 /*
1473 * Receive-side routines.
1474 */
1475
1476 /* misuse a few fields of the skb for MP reconstruction */
1477 #define sequence priority
1478 #define BEbits cb[0]
1479
1480 static inline void
1481 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1482 {
1483 ppp_recv_lock(ppp);
1484 /* ppp->dev == 0 means interface is closing down */
1485 if (ppp->dev != 0)
1486 ppp_receive_frame(ppp, skb, pch);
1487 else
1488 kfree_skb(skb);
1489 ppp_recv_unlock(ppp);
1490 }
1491
1492 void
1493 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1494 {
1495 struct channel *pch = chan->ppp;
1496 int proto;
1497
1498 if (pch == 0 || skb->len == 0) {
1499 kfree_skb(skb);
1500 return;
1501 }
1502
1503 proto = PPP_PROTO(skb);
1504 read_lock_bh(&pch->upl);
1505 if (pch->ppp == 0 || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1506 /* put it on the channel queue */
1507 skb_queue_tail(&pch->file.rq, skb);
1508 /* drop old frames if queue too long */
1509 while (pch->file.rq.qlen > PPP_MAX_RQLEN
1510 && (skb = skb_dequeue(&pch->file.rq)) != 0)
1511 kfree_skb(skb);
1512 wake_up_interruptible(&pch->file.rwait);
1513 } else {
1514 ppp_do_recv(pch->ppp, skb, pch);
1515 }
1516 read_unlock_bh(&pch->upl);
1517 }
1518
1519 /* Put a 0-length skb in the receive queue as an error indication */
1520 void
1521 ppp_input_error(struct ppp_channel *chan, int code)
1522 {
1523 struct channel *pch = chan->ppp;
1524 struct sk_buff *skb;
1525
1526 if (pch == 0)
1527 return;
1528
1529 read_lock_bh(&pch->upl);
1530 if (pch->ppp != 0) {
1531 skb = alloc_skb(0, GFP_ATOMIC);
1532 if (skb != 0) {
1533 skb->len = 0; /* probably unnecessary */
1534 skb->cb[0] = code;
1535 ppp_do_recv(pch->ppp, skb, pch);
1536 }
1537 }
1538 read_unlock_bh(&pch->upl);
1539 }
1540
1541 /*
1542 * We come in here to process a received frame.
1543 * The receive side of the ppp unit is locked.
1544 */
1545 static void
1546 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1547 {
1548 if (skb->len >= 2) {
1549 #ifdef CONFIG_PPP_MULTILINK
1550 /* XXX do channel-level decompression here */
1551 if (PPP_PROTO(skb) == PPP_MP)
1552 ppp_receive_mp_frame(ppp, skb, pch);
1553 else
1554 #endif /* CONFIG_PPP_MULTILINK */
1555 ppp_receive_nonmp_frame(ppp, skb);
1556 return;
1557 }
1558
1559 if (skb->len > 0)
1560 /* note: a 0-length skb is used as an error indication */
1561 ++ppp->stats.rx_length_errors;
1562
1563 kfree_skb(skb);
1564 ppp_receive_error(ppp);
1565 }
1566
1567 static void
1568 ppp_receive_error(struct ppp *ppp)
1569 {
1570 ++ppp->stats.rx_errors;
1571 if (ppp->vj != 0)
1572 slhc_toss(ppp->vj);
1573 }
1574
1575 static void
1576 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1577 {
1578 struct sk_buff *ns;
1579 int proto, len, npi;
1580
1581 /*
1582 * Decompress the frame, if compressed.
1583 * Note that some decompressors need to see uncompressed frames
1584 * that come in as well as compressed frames.
1585 */
1586 if (ppp->rc_state != 0 && (ppp->rstate & SC_DECOMP_RUN)
1587 && (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1588 skb = ppp_decompress_frame(ppp, skb);
1589
1590 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1591 goto err;
1592
1593 proto = PPP_PROTO(skb);
1594 switch (proto) {
1595 case PPP_VJC_COMP:
1596 /* decompress VJ compressed packets */
1597 if (ppp->vj == 0 || (ppp->flags & SC_REJ_COMP_TCP))
1598 goto err;
1599
1600 if (skb_tailroom(skb) < 124) {
1601 /* copy to a new sk_buff with more tailroom */
1602 ns = dev_alloc_skb(skb->len + 128);
1603 if (ns == 0) {
1604 printk(KERN_ERR"PPP: no memory (VJ decomp)\n");
1605 goto err;
1606 }
1607 skb_reserve(ns, 2);
1608 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1609 kfree_skb(skb);
1610 skb = ns;
1611 }
1612 else if (!pskb_may_pull(skb, skb->len))
1613 goto err;
1614 else
1615 skb->ip_summed = CHECKSUM_NONE;
1616
1617 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1618 if (len <= 0) {
1619 printk(KERN_DEBUG "PPP: VJ decompression error\n");
1620 goto err;
1621 }
1622 len += 2;
1623 if (len > skb->len)
1624 skb_put(skb, len - skb->len);
1625 else if (len < skb->len)
1626 skb_trim(skb, len);
1627 proto = PPP_IP;
1628 break;
1629
1630 case PPP_VJC_UNCOMP:
1631 if (ppp->vj == 0 || (ppp->flags & SC_REJ_COMP_TCP))
1632 goto err;
1633
1634 /* Until we fix the decompressor need to make sure
1635 * data portion is linear.
1636 */
1637 if (!pskb_may_pull(skb, skb->len))
1638 goto err;
1639
1640 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1641 printk(KERN_ERR "PPP: VJ uncompressed error\n");
1642 goto err;
1643 }
1644 proto = PPP_IP;
1645 break;
1646
1647 case PPP_CCP:
1648 ppp_ccp_peek(ppp, skb, 1);
1649 break;
1650 }
1651
1652 ++ppp->stats.rx_packets;
1653 ppp->stats.rx_bytes += skb->len - 2;
1654
1655 npi = proto_to_npindex(proto);
1656 if (npi < 0) {
1657 /* control or unknown frame - pass it to pppd */
1658 skb_queue_tail(&ppp->file.rq, skb);
1659 /* limit queue length by dropping old frames */
1660 while (ppp->file.rq.qlen > PPP_MAX_RQLEN
1661 && (skb = skb_dequeue(&ppp->file.rq)) != 0)
1662 kfree_skb(skb);
1663 /* wake up any process polling or blocking on read */
1664 wake_up_interruptible(&ppp->file.rwait);
1665
1666 } else {
1667 /* network protocol frame - give it to the kernel */
1668
1669 #ifdef CONFIG_PPP_FILTER
1670 /* check if the packet passes the pass and active filters */
1671 /* the filter instructions are constructed assuming
1672 a four-byte PPP header on each packet */
1673 *skb_push(skb, 2) = 0;
1674 if (ppp->pass_filter
1675 && sk_run_filter(skb, ppp->pass_filter,
1676 ppp->pass_len) == 0) {
1677 if (ppp->debug & 1)
1678 printk(KERN_DEBUG "PPP: inbound frame not passed\n");
1679 kfree_skb(skb);
1680 return;
1681 }
1682 if (!(ppp->active_filter
1683 && sk_run_filter(skb, ppp->active_filter,
1684 ppp->active_len) == 0))
1685 ppp->last_recv = jiffies;
1686 skb_pull(skb, 2);
1687 #else
1688 ppp->last_recv = jiffies;
1689 #endif /* CONFIG_PPP_FILTER */
1690
1691 if ((ppp->dev->flags & IFF_UP) == 0
1692 || ppp->npmode[npi] != NPMODE_PASS) {
1693 kfree_skb(skb);
1694 } else {
1695 /* chop off protocol */
1696 skb_pull_rcsum(skb, 2);
1697 skb->dev = ppp->dev;
1698 skb->protocol = htons(npindex_to_ethertype[npi]);
1699 skb->mac.raw = skb->data;
1700 netif_rx(skb);
1701 ppp->dev->last_rx = jiffies;
1702 }
1703 }
1704 return;
1705
1706 err:
1707 kfree_skb(skb);
1708 ppp_receive_error(ppp);
1709 }
1710
1711 static struct sk_buff *
1712 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1713 {
1714 int proto = PPP_PROTO(skb);
1715 struct sk_buff *ns;
1716 int len;
1717
1718 /* Until we fix all the decompressor's need to make sure
1719 * data portion is linear.
1720 */
1721 if (!pskb_may_pull(skb, skb->len))
1722 goto err;
1723
1724 if (proto == PPP_COMP) {
1725 ns = dev_alloc_skb(ppp->mru + PPP_HDRLEN);
1726 if (ns == 0) {
1727 printk(KERN_ERR "ppp_decompress_frame: no memory\n");
1728 goto err;
1729 }
1730 /* the decompressor still expects the A/C bytes in the hdr */
1731 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1732 skb->len + 2, ns->data, ppp->mru + PPP_HDRLEN);
1733 if (len < 0) {
1734 /* Pass the compressed frame to pppd as an
1735 error indication. */
1736 if (len == DECOMP_FATALERROR)
1737 ppp->rstate |= SC_DC_FERROR;
1738 kfree_skb(ns);
1739 goto err;
1740 }
1741
1742 kfree_skb(skb);
1743 skb = ns;
1744 skb_put(skb, len);
1745 skb_pull(skb, 2); /* pull off the A/C bytes */
1746
1747 } else {
1748 /* Uncompressed frame - pass to decompressor so it
1749 can update its dictionary if necessary. */
1750 if (ppp->rcomp->incomp)
1751 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1752 skb->len + 2);
1753 }
1754
1755 return skb;
1756
1757 err:
1758 ppp->rstate |= SC_DC_ERROR;
1759 ppp_receive_error(ppp);
1760 return skb;
1761 }
1762
1763 #ifdef CONFIG_PPP_MULTILINK
1764 /*
1765 * Receive a multilink frame.
1766 * We put it on the reconstruction queue and then pull off
1767 * as many completed frames as we can.
1768 */
1769 static void
1770 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1771 {
1772 u32 mask, seq;
1773 struct channel *ch;
1774 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1775
1776 if (!pskb_may_pull(skb, mphdrlen) || ppp->mrru == 0)
1777 goto err; /* no good, throw it away */
1778
1779 /* Decode sequence number and begin/end bits */
1780 if (ppp->flags & SC_MP_SHORTSEQ) {
1781 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1782 mask = 0xfff;
1783 } else {
1784 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1785 mask = 0xffffff;
1786 }
1787 skb->BEbits = skb->data[2];
1788 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
1789
1790 /*
1791 * Do protocol ID decompression on the first fragment of each packet.
1792 */
1793 if ((skb->BEbits & B) && (skb->data[0] & 1))
1794 *skb_push(skb, 1) = 0;
1795
1796 /*
1797 * Expand sequence number to 32 bits, making it as close
1798 * as possible to ppp->minseq.
1799 */
1800 seq |= ppp->minseq & ~mask;
1801 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
1802 seq += mask + 1;
1803 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
1804 seq -= mask + 1; /* should never happen */
1805 skb->sequence = seq;
1806 pch->lastseq = seq;
1807
1808 /*
1809 * If this packet comes before the next one we were expecting,
1810 * drop it.
1811 */
1812 if (seq_before(seq, ppp->nextseq)) {
1813 kfree_skb(skb);
1814 ++ppp->stats.rx_dropped;
1815 ppp_receive_error(ppp);
1816 return;
1817 }
1818
1819 /*
1820 * Reevaluate minseq, the minimum over all channels of the
1821 * last sequence number received on each channel. Because of
1822 * the increasing sequence number rule, we know that any fragment
1823 * before `minseq' which hasn't arrived is never going to arrive.
1824 * The list of channels can't change because we have the receive
1825 * side of the ppp unit locked.
1826 */
1827 list_for_each_entry(ch, &ppp->channels, clist) {
1828 if (seq_before(ch->lastseq, seq))
1829 seq = ch->lastseq;
1830 }
1831 if (seq_before(ppp->minseq, seq))
1832 ppp->minseq = seq;
1833
1834 /* Put the fragment on the reconstruction queue */
1835 ppp_mp_insert(ppp, skb);
1836
1837 /* If the queue is getting long, don't wait any longer for packets
1838 before the start of the queue. */
1839 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN
1840 && seq_before(ppp->minseq, ppp->mrq.next->sequence))
1841 ppp->minseq = ppp->mrq.next->sequence;
1842
1843 /* Pull completed packets off the queue and receive them. */
1844 while ((skb = ppp_mp_reconstruct(ppp)) != 0)
1845 ppp_receive_nonmp_frame(ppp, skb);
1846
1847 return;
1848
1849 err:
1850 kfree_skb(skb);
1851 ppp_receive_error(ppp);
1852 }
1853
1854 /*
1855 * Insert a fragment on the MP reconstruction queue.
1856 * The queue is ordered by increasing sequence number.
1857 */
1858 static void
1859 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
1860 {
1861 struct sk_buff *p;
1862 struct sk_buff_head *list = &ppp->mrq;
1863 u32 seq = skb->sequence;
1864
1865 /* N.B. we don't need to lock the list lock because we have the
1866 ppp unit receive-side lock. */
1867 for (p = list->next; p != (struct sk_buff *)list; p = p->next)
1868 if (seq_before(seq, p->sequence))
1869 break;
1870 __skb_insert(skb, p->prev, p, list);
1871 }
1872
1873 /*
1874 * Reconstruct a packet from the MP fragment queue.
1875 * We go through increasing sequence numbers until we find a
1876 * complete packet, or we get to the sequence number for a fragment
1877 * which hasn't arrived but might still do so.
1878 */
1879 struct sk_buff *
1880 ppp_mp_reconstruct(struct ppp *ppp)
1881 {
1882 u32 seq = ppp->nextseq;
1883 u32 minseq = ppp->minseq;
1884 struct sk_buff_head *list = &ppp->mrq;
1885 struct sk_buff *p, *next;
1886 struct sk_buff *head, *tail;
1887 struct sk_buff *skb = NULL;
1888 int lost = 0, len = 0;
1889
1890 if (ppp->mrru == 0) /* do nothing until mrru is set */
1891 return NULL;
1892 head = list->next;
1893 tail = NULL;
1894 for (p = head; p != (struct sk_buff *) list; p = next) {
1895 next = p->next;
1896 if (seq_before(p->sequence, seq)) {
1897 /* this can't happen, anyway ignore the skb */
1898 printk(KERN_ERR "ppp_mp_reconstruct bad seq %u < %u\n",
1899 p->sequence, seq);
1900 head = next;
1901 continue;
1902 }
1903 if (p->sequence != seq) {
1904 /* Fragment `seq' is missing. If it is after
1905 minseq, it might arrive later, so stop here. */
1906 if (seq_after(seq, minseq))
1907 break;
1908 /* Fragment `seq' is lost, keep going. */
1909 lost = 1;
1910 seq = seq_before(minseq, p->sequence)?
1911 minseq + 1: p->sequence;
1912 next = p;
1913 continue;
1914 }
1915
1916 /*
1917 * At this point we know that all the fragments from
1918 * ppp->nextseq to seq are either present or lost.
1919 * Also, there are no complete packets in the queue
1920 * that have no missing fragments and end before this
1921 * fragment.
1922 */
1923
1924 /* B bit set indicates this fragment starts a packet */
1925 if (p->BEbits & B) {
1926 head = p;
1927 lost = 0;
1928 len = 0;
1929 }
1930
1931 len += p->len;
1932
1933 /* Got a complete packet yet? */
1934 if (lost == 0 && (p->BEbits & E) && (head->BEbits & B)) {
1935 if (len > ppp->mrru + 2) {
1936 ++ppp->stats.rx_length_errors;
1937 printk(KERN_DEBUG "PPP: reconstructed packet"
1938 " is too long (%d)\n", len);
1939 } else if (p == head) {
1940 /* fragment is complete packet - reuse skb */
1941 tail = p;
1942 skb = skb_get(p);
1943 break;
1944 } else if ((skb = dev_alloc_skb(len)) == NULL) {
1945 ++ppp->stats.rx_missed_errors;
1946 printk(KERN_DEBUG "PPP: no memory for "
1947 "reconstructed packet");
1948 } else {
1949 tail = p;
1950 break;
1951 }
1952 ppp->nextseq = seq + 1;
1953 }
1954
1955 /*
1956 * If this is the ending fragment of a packet,
1957 * and we haven't found a complete valid packet yet,
1958 * we can discard up to and including this fragment.
1959 */
1960 if (p->BEbits & E)
1961 head = next;
1962
1963 ++seq;
1964 }
1965
1966 /* If we have a complete packet, copy it all into one skb. */
1967 if (tail != NULL) {
1968 /* If we have discarded any fragments,
1969 signal a receive error. */
1970 if (head->sequence != ppp->nextseq) {
1971 if (ppp->debug & 1)
1972 printk(KERN_DEBUG " missed pkts %u..%u\n",
1973 ppp->nextseq, head->sequence-1);
1974 ++ppp->stats.rx_dropped;
1975 ppp_receive_error(ppp);
1976 }
1977
1978 if (head != tail)
1979 /* copy to a single skb */
1980 for (p = head; p != tail->next; p = p->next)
1981 skb_copy_bits(p, 0, skb_put(skb, p->len), p->len);
1982 ppp->nextseq = tail->sequence + 1;
1983 head = tail->next;
1984 }
1985
1986 /* Discard all the skbuffs that we have copied the data out of
1987 or that we can't use. */
1988 while ((p = list->next) != head) {
1989 __skb_unlink(p, list);
1990 kfree_skb(p);
1991 }
1992
1993 return skb;
1994 }
1995 #endif /* CONFIG_PPP_MULTILINK */
1996
1997 /*
1998 * Channel interface.
1999 */
2000
2001 /*
2002 * Create a new, unattached ppp channel.
2003 */
2004 int
2005 ppp_register_channel(struct ppp_channel *chan)
2006 {
2007 struct channel *pch;
2008
2009 pch = kmalloc(sizeof(struct channel), GFP_KERNEL);
2010 if (pch == 0)
2011 return -ENOMEM;
2012 memset(pch, 0, sizeof(struct channel));
2013 pch->ppp = NULL;
2014 pch->chan = chan;
2015 chan->ppp = pch;
2016 init_ppp_file(&pch->file, CHANNEL);
2017 pch->file.hdrlen = chan->hdrlen;
2018 #ifdef CONFIG_PPP_MULTILINK
2019 pch->lastseq = -1;
2020 #endif /* CONFIG_PPP_MULTILINK */
2021 init_rwsem(&pch->chan_sem);
2022 spin_lock_init(&pch->downl);
2023 rwlock_init(&pch->upl);
2024 spin_lock_bh(&all_channels_lock);
2025 pch->file.index = ++last_channel_index;
2026 list_add(&pch->list, &new_channels);
2027 atomic_inc(&channel_count);
2028 spin_unlock_bh(&all_channels_lock);
2029 return 0;
2030 }
2031
2032 /*
2033 * Return the index of a channel.
2034 */
2035 int ppp_channel_index(struct ppp_channel *chan)
2036 {
2037 struct channel *pch = chan->ppp;
2038
2039 if (pch != 0)
2040 return pch->file.index;
2041 return -1;
2042 }
2043
2044 /*
2045 * Return the PPP unit number to which a channel is connected.
2046 */
2047 int ppp_unit_number(struct ppp_channel *chan)
2048 {
2049 struct channel *pch = chan->ppp;
2050 int unit = -1;
2051
2052 if (pch != 0) {
2053 read_lock_bh(&pch->upl);
2054 if (pch->ppp != 0)
2055 unit = pch->ppp->file.index;
2056 read_unlock_bh(&pch->upl);
2057 }
2058 return unit;
2059 }
2060
2061 /*
2062 * Disconnect a channel from the generic layer.
2063 * This must be called in process context.
2064 */
2065 void
2066 ppp_unregister_channel(struct ppp_channel *chan)
2067 {
2068 struct channel *pch = chan->ppp;
2069
2070 if (pch == 0)
2071 return; /* should never happen */
2072 chan->ppp = NULL;
2073
2074 /*
2075 * This ensures that we have returned from any calls into the
2076 * the channel's start_xmit or ioctl routine before we proceed.
2077 */
2078 down_write(&pch->chan_sem);
2079 spin_lock_bh(&pch->downl);
2080 pch->chan = NULL;
2081 spin_unlock_bh(&pch->downl);
2082 up_write(&pch->chan_sem);
2083 ppp_disconnect_channel(pch);
2084 spin_lock_bh(&all_channels_lock);
2085 list_del(&pch->list);
2086 spin_unlock_bh(&all_channels_lock);
2087 pch->file.dead = 1;
2088 wake_up_interruptible(&pch->file.rwait);
2089 if (atomic_dec_and_test(&pch->file.refcnt))
2090 ppp_destroy_channel(pch);
2091 }
2092
2093 /*
2094 * Callback from a channel when it can accept more to transmit.
2095 * This should be called at BH/softirq level, not interrupt level.
2096 */
2097 void
2098 ppp_output_wakeup(struct ppp_channel *chan)
2099 {
2100 struct channel *pch = chan->ppp;
2101
2102 if (pch == 0)
2103 return;
2104 ppp_channel_push(pch);
2105 }
2106
2107 /*
2108 * Compression control.
2109 */
2110
2111 /* Process the PPPIOCSCOMPRESS ioctl. */
2112 static int
2113 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2114 {
2115 int err;
2116 struct compressor *cp, *ocomp;
2117 struct ppp_option_data data;
2118 void *state, *ostate;
2119 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2120
2121 err = -EFAULT;
2122 if (copy_from_user(&data, (void __user *) arg, sizeof(data))
2123 || (data.length <= CCP_MAX_OPTION_LENGTH
2124 && copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2125 goto out;
2126 err = -EINVAL;
2127 if (data.length > CCP_MAX_OPTION_LENGTH
2128 || ccp_option[1] < 2 || ccp_option[1] > data.length)
2129 goto out;
2130
2131 cp = find_compressor(ccp_option[0]);
2132 #ifdef CONFIG_KMOD
2133 if (cp == 0) {
2134 request_module("ppp-compress-%d", ccp_option[0]);
2135 cp = find_compressor(ccp_option[0]);
2136 }
2137 #endif /* CONFIG_KMOD */
2138 if (cp == 0)
2139 goto out;
2140
2141 err = -ENOBUFS;
2142 if (data.transmit) {
2143 state = cp->comp_alloc(ccp_option, data.length);
2144 if (state != 0) {
2145 ppp_xmit_lock(ppp);
2146 ppp->xstate &= ~SC_COMP_RUN;
2147 ocomp = ppp->xcomp;
2148 ostate = ppp->xc_state;
2149 ppp->xcomp = cp;
2150 ppp->xc_state = state;
2151 ppp_xmit_unlock(ppp);
2152 if (ostate != 0) {
2153 ocomp->comp_free(ostate);
2154 module_put(ocomp->owner);
2155 }
2156 err = 0;
2157 } else
2158 module_put(cp->owner);
2159
2160 } else {
2161 state = cp->decomp_alloc(ccp_option, data.length);
2162 if (state != 0) {
2163 ppp_recv_lock(ppp);
2164 ppp->rstate &= ~SC_DECOMP_RUN;
2165 ocomp = ppp->rcomp;
2166 ostate = ppp->rc_state;
2167 ppp->rcomp = cp;
2168 ppp->rc_state = state;
2169 ppp_recv_unlock(ppp);
2170 if (ostate != 0) {
2171 ocomp->decomp_free(ostate);
2172 module_put(ocomp->owner);
2173 }
2174 err = 0;
2175 } else
2176 module_put(cp->owner);
2177 }
2178
2179 out:
2180 return err;
2181 }
2182
2183 /*
2184 * Look at a CCP packet and update our state accordingly.
2185 * We assume the caller has the xmit or recv path locked.
2186 */
2187 static void
2188 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2189 {
2190 unsigned char *dp;
2191 int len;
2192
2193 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2194 return; /* no header */
2195 dp = skb->data + 2;
2196
2197 switch (CCP_CODE(dp)) {
2198 case CCP_CONFREQ:
2199
2200 /* A ConfReq starts negotiation of compression
2201 * in one direction of transmission,
2202 * and hence brings it down...but which way?
2203 *
2204 * Remember:
2205 * A ConfReq indicates what the sender would like to receive
2206 */
2207 if(inbound)
2208 /* He is proposing what I should send */
2209 ppp->xstate &= ~SC_COMP_RUN;
2210 else
2211 /* I am proposing to what he should send */
2212 ppp->rstate &= ~SC_DECOMP_RUN;
2213
2214 break;
2215
2216 case CCP_TERMREQ:
2217 case CCP_TERMACK:
2218 /*
2219 * CCP is going down, both directions of transmission
2220 */
2221 ppp->rstate &= ~SC_DECOMP_RUN;
2222 ppp->xstate &= ~SC_COMP_RUN;
2223 break;
2224
2225 case CCP_CONFACK:
2226 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2227 break;
2228 len = CCP_LENGTH(dp);
2229 if (!pskb_may_pull(skb, len + 2))
2230 return; /* too short */
2231 dp += CCP_HDRLEN;
2232 len -= CCP_HDRLEN;
2233 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2234 break;
2235 if (inbound) {
2236 /* we will start receiving compressed packets */
2237 if (ppp->rc_state == 0)
2238 break;
2239 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2240 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2241 ppp->rstate |= SC_DECOMP_RUN;
2242 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2243 }
2244 } else {
2245 /* we will soon start sending compressed packets */
2246 if (ppp->xc_state == 0)
2247 break;
2248 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2249 ppp->file.index, 0, ppp->debug))
2250 ppp->xstate |= SC_COMP_RUN;
2251 }
2252 break;
2253
2254 case CCP_RESETACK:
2255 /* reset the [de]compressor */
2256 if ((ppp->flags & SC_CCP_UP) == 0)
2257 break;
2258 if (inbound) {
2259 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2260 ppp->rcomp->decomp_reset(ppp->rc_state);
2261 ppp->rstate &= ~SC_DC_ERROR;
2262 }
2263 } else {
2264 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2265 ppp->xcomp->comp_reset(ppp->xc_state);
2266 }
2267 break;
2268 }
2269 }
2270
2271 /* Free up compression resources. */
2272 static void
2273 ppp_ccp_closed(struct ppp *ppp)
2274 {
2275 void *xstate, *rstate;
2276 struct compressor *xcomp, *rcomp;
2277
2278 ppp_lock(ppp);
2279 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2280 ppp->xstate = 0;
2281 xcomp = ppp->xcomp;
2282 xstate = ppp->xc_state;
2283 ppp->xc_state = NULL;
2284 ppp->rstate = 0;
2285 rcomp = ppp->rcomp;
2286 rstate = ppp->rc_state;
2287 ppp->rc_state = NULL;
2288 ppp_unlock(ppp);
2289
2290 if (xstate) {
2291 xcomp->comp_free(xstate);
2292 module_put(xcomp->owner);
2293 }
2294 if (rstate) {
2295 rcomp->decomp_free(rstate);
2296 module_put(rcomp->owner);
2297 }
2298 }
2299
2300 /* List of compressors. */
2301 static LIST_HEAD(compressor_list);
2302 static DEFINE_SPINLOCK(compressor_list_lock);
2303
2304 struct compressor_entry {
2305 struct list_head list;
2306 struct compressor *comp;
2307 };
2308
2309 static struct compressor_entry *
2310 find_comp_entry(int proto)
2311 {
2312 struct compressor_entry *ce;
2313
2314 list_for_each_entry(ce, &compressor_list, list) {
2315 if (ce->comp->compress_proto == proto)
2316 return ce;
2317 }
2318 return NULL;
2319 }
2320
2321 /* Register a compressor */
2322 int
2323 ppp_register_compressor(struct compressor *cp)
2324 {
2325 struct compressor_entry *ce;
2326 int ret;
2327 spin_lock(&compressor_list_lock);
2328 ret = -EEXIST;
2329 if (find_comp_entry(cp->compress_proto) != 0)
2330 goto out;
2331 ret = -ENOMEM;
2332 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2333 if (ce == 0)
2334 goto out;
2335 ret = 0;
2336 ce->comp = cp;
2337 list_add(&ce->list, &compressor_list);
2338 out:
2339 spin_unlock(&compressor_list_lock);
2340 return ret;
2341 }
2342
2343 /* Unregister a compressor */
2344 void
2345 ppp_unregister_compressor(struct compressor *cp)
2346 {
2347 struct compressor_entry *ce;
2348
2349 spin_lock(&compressor_list_lock);
2350 ce = find_comp_entry(cp->compress_proto);
2351 if (ce != 0 && ce->comp == cp) {
2352 list_del(&ce->list);
2353 kfree(ce);
2354 }
2355 spin_unlock(&compressor_list_lock);
2356 }
2357
2358 /* Find a compressor. */
2359 static struct compressor *
2360 find_compressor(int type)
2361 {
2362 struct compressor_entry *ce;
2363 struct compressor *cp = NULL;
2364
2365 spin_lock(&compressor_list_lock);
2366 ce = find_comp_entry(type);
2367 if (ce != 0) {
2368 cp = ce->comp;
2369 if (!try_module_get(cp->owner))
2370 cp = NULL;
2371 }
2372 spin_unlock(&compressor_list_lock);
2373 return cp;
2374 }
2375
2376 /*
2377 * Miscelleneous stuff.
2378 */
2379
2380 static void
2381 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2382 {
2383 struct slcompress *vj = ppp->vj;
2384
2385 memset(st, 0, sizeof(*st));
2386 st->p.ppp_ipackets = ppp->stats.rx_packets;
2387 st->p.ppp_ierrors = ppp->stats.rx_errors;
2388 st->p.ppp_ibytes = ppp->stats.rx_bytes;
2389 st->p.ppp_opackets = ppp->stats.tx_packets;
2390 st->p.ppp_oerrors = ppp->stats.tx_errors;
2391 st->p.ppp_obytes = ppp->stats.tx_bytes;
2392 if (vj == 0)
2393 return;
2394 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2395 st->vj.vjs_compressed = vj->sls_o_compressed;
2396 st->vj.vjs_searches = vj->sls_o_searches;
2397 st->vj.vjs_misses = vj->sls_o_misses;
2398 st->vj.vjs_errorin = vj->sls_i_error;
2399 st->vj.vjs_tossed = vj->sls_i_tossed;
2400 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2401 st->vj.vjs_compressedin = vj->sls_i_compressed;
2402 }
2403
2404 /*
2405 * Stuff for handling the lists of ppp units and channels
2406 * and for initialization.
2407 */
2408
2409 /*
2410 * Create a new ppp interface unit. Fails if it can't allocate memory
2411 * or if there is already a unit with the requested number.
2412 * unit == -1 means allocate a new number.
2413 */
2414 static struct ppp *
2415 ppp_create_interface(int unit, int *retp)
2416 {
2417 struct ppp *ppp;
2418 struct net_device *dev = NULL;
2419 int ret = -ENOMEM;
2420 int i;
2421
2422 ppp = kmalloc(sizeof(struct ppp), GFP_KERNEL);
2423 if (!ppp)
2424 goto out;
2425 dev = alloc_netdev(0, "", ppp_setup);
2426 if (!dev)
2427 goto out1;
2428 memset(ppp, 0, sizeof(struct ppp));
2429
2430 ppp->mru = PPP_MRU;
2431 init_ppp_file(&ppp->file, INTERFACE);
2432 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2433 for (i = 0; i < NUM_NP; ++i)
2434 ppp->npmode[i] = NPMODE_PASS;
2435 INIT_LIST_HEAD(&ppp->channels);
2436 spin_lock_init(&ppp->rlock);
2437 spin_lock_init(&ppp->wlock);
2438 #ifdef CONFIG_PPP_MULTILINK
2439 ppp->minseq = -1;
2440 skb_queue_head_init(&ppp->mrq);
2441 #endif /* CONFIG_PPP_MULTILINK */
2442 ppp->dev = dev;
2443 dev->priv = ppp;
2444
2445 dev->hard_start_xmit = ppp_start_xmit;
2446 dev->get_stats = ppp_net_stats;
2447 dev->do_ioctl = ppp_net_ioctl;
2448
2449 ret = -EEXIST;
2450 mutex_lock(&all_ppp_mutex);
2451 if (unit < 0)
2452 unit = cardmap_find_first_free(all_ppp_units);
2453 else if (cardmap_get(all_ppp_units, unit) != NULL)
2454 goto out2; /* unit already exists */
2455
2456 /* Initialize the new ppp unit */
2457 ppp->file.index = unit;
2458 sprintf(dev->name, "ppp%d", unit);
2459
2460 ret = register_netdev(dev);
2461 if (ret != 0) {
2462 printk(KERN_ERR "PPP: couldn't register device %s (%d)\n",
2463 dev->name, ret);
2464 goto out2;
2465 }
2466
2467 atomic_inc(&ppp_unit_count);
2468 cardmap_set(&all_ppp_units, unit, ppp);
2469 mutex_unlock(&all_ppp_mutex);
2470 *retp = 0;
2471 return ppp;
2472
2473 out2:
2474 mutex_unlock(&all_ppp_mutex);
2475 free_netdev(dev);
2476 out1:
2477 kfree(ppp);
2478 out:
2479 *retp = ret;
2480 return NULL;
2481 }
2482
2483 /*
2484 * Initialize a ppp_file structure.
2485 */
2486 static void
2487 init_ppp_file(struct ppp_file *pf, int kind)
2488 {
2489 pf->kind = kind;
2490 skb_queue_head_init(&pf->xq);
2491 skb_queue_head_init(&pf->rq);
2492 atomic_set(&pf->refcnt, 1);
2493 init_waitqueue_head(&pf->rwait);
2494 }
2495
2496 /*
2497 * Take down a ppp interface unit - called when the owning file
2498 * (the one that created the unit) is closed or detached.
2499 */
2500 static void ppp_shutdown_interface(struct ppp *ppp)
2501 {
2502 struct net_device *dev;
2503
2504 mutex_lock(&all_ppp_mutex);
2505 ppp_lock(ppp);
2506 dev = ppp->dev;
2507 ppp->dev = NULL;
2508 ppp_unlock(ppp);
2509 /* This will call dev_close() for us. */
2510 if (dev) {
2511 unregister_netdev(dev);
2512 free_netdev(dev);
2513 }
2514 cardmap_set(&all_ppp_units, ppp->file.index, NULL);
2515 ppp->file.dead = 1;
2516 ppp->owner = NULL;
2517 wake_up_interruptible(&ppp->file.rwait);
2518 mutex_unlock(&all_ppp_mutex);
2519 }
2520
2521 /*
2522 * Free the memory used by a ppp unit. This is only called once
2523 * there are no channels connected to the unit and no file structs
2524 * that reference the unit.
2525 */
2526 static void ppp_destroy_interface(struct ppp *ppp)
2527 {
2528 atomic_dec(&ppp_unit_count);
2529
2530 if (!ppp->file.dead || ppp->n_channels) {
2531 /* "can't happen" */
2532 printk(KERN_ERR "ppp: destroying ppp struct %p but dead=%d "
2533 "n_channels=%d !\n", ppp, ppp->file.dead,
2534 ppp->n_channels);
2535 return;
2536 }
2537
2538 ppp_ccp_closed(ppp);
2539 if (ppp->vj) {
2540 slhc_free(ppp->vj);
2541 ppp->vj = NULL;
2542 }
2543 skb_queue_purge(&ppp->file.xq);
2544 skb_queue_purge(&ppp->file.rq);
2545 #ifdef CONFIG_PPP_MULTILINK
2546 skb_queue_purge(&ppp->mrq);
2547 #endif /* CONFIG_PPP_MULTILINK */
2548 #ifdef CONFIG_PPP_FILTER
2549 kfree(ppp->pass_filter);
2550 ppp->pass_filter = NULL;
2551 kfree(ppp->active_filter);
2552 ppp->active_filter = NULL;
2553 #endif /* CONFIG_PPP_FILTER */
2554
2555 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_del(&pch->list);
2584 list_add(&pch->list, &all_channels);
2585 return pch;
2586 }
2587 }
2588 list_for_each_entry(pch, &all_channels, list) {
2589 if (pch->file.index == unit)
2590 return pch;
2591 }
2592 return NULL;
2593 }
2594
2595 /*
2596 * Connect a PPP channel to a PPP interface unit.
2597 */
2598 static int
2599 ppp_connect_channel(struct channel *pch, int unit)
2600 {
2601 struct ppp *ppp;
2602 int ret = -ENXIO;
2603 int hdrlen;
2604
2605 mutex_lock(&all_ppp_mutex);
2606 ppp = ppp_find_unit(unit);
2607 if (ppp == 0)
2608 goto out;
2609 write_lock_bh(&pch->upl);
2610 ret = -EINVAL;
2611 if (pch->ppp != 0)
2612 goto outl;
2613
2614 ppp_lock(ppp);
2615 if (pch->file.hdrlen > ppp->file.hdrlen)
2616 ppp->file.hdrlen = pch->file.hdrlen;
2617 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2618 if (ppp->dev && hdrlen > ppp->dev->hard_header_len)
2619 ppp->dev->hard_header_len = hdrlen;
2620 list_add_tail(&pch->clist, &ppp->channels);
2621 ++ppp->n_channels;
2622 pch->ppp = ppp;
2623 atomic_inc(&ppp->file.refcnt);
2624 ppp_unlock(ppp);
2625 ret = 0;
2626
2627 outl:
2628 write_unlock_bh(&pch->upl);
2629 out:
2630 mutex_unlock(&all_ppp_mutex);
2631 return ret;
2632 }
2633
2634 /*
2635 * Disconnect a channel from its ppp unit.
2636 */
2637 static int
2638 ppp_disconnect_channel(struct channel *pch)
2639 {
2640 struct ppp *ppp;
2641 int err = -EINVAL;
2642
2643 write_lock_bh(&pch->upl);
2644 ppp = pch->ppp;
2645 pch->ppp = NULL;
2646 write_unlock_bh(&pch->upl);
2647 if (ppp != 0) {
2648 /* remove it from the ppp unit's list */
2649 ppp_lock(ppp);
2650 list_del(&pch->clist);
2651 if (--ppp->n_channels == 0)
2652 wake_up_interruptible(&ppp->file.rwait);
2653 ppp_unlock(ppp);
2654 if (atomic_dec_and_test(&ppp->file.refcnt))
2655 ppp_destroy_interface(ppp);
2656 err = 0;
2657 }
2658 return err;
2659 }
2660
2661 /*
2662 * Free up the resources used by a ppp channel.
2663 */
2664 static void ppp_destroy_channel(struct channel *pch)
2665 {
2666 atomic_dec(&channel_count);
2667
2668 if (!pch->file.dead) {
2669 /* "can't happen" */
2670 printk(KERN_ERR "ppp: destroying undead channel %p !\n",
2671 pch);
2672 return;
2673 }
2674 skb_queue_purge(&pch->file.xq);
2675 skb_queue_purge(&pch->file.rq);
2676 kfree(pch);
2677 }
2678
2679 static void __exit ppp_cleanup(void)
2680 {
2681 /* should never happen */
2682 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2683 printk(KERN_ERR "PPP: removing module but units remain!\n");
2684 cardmap_destroy(&all_ppp_units);
2685 if (unregister_chrdev(PPP_MAJOR, "ppp") != 0)
2686 printk(KERN_ERR "PPP: failed to unregister PPP device\n");
2687 devfs_remove("ppp");
2688 class_device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
2689 class_destroy(ppp_class);
2690 }
2691
2692 /*
2693 * Cardmap implementation.
2694 */
2695 static void *cardmap_get(struct cardmap *map, unsigned int nr)
2696 {
2697 struct cardmap *p;
2698 int i;
2699
2700 for (p = map; p != NULL; ) {
2701 if ((i = nr >> p->shift) >= CARDMAP_WIDTH)
2702 return NULL;
2703 if (p->shift == 0)
2704 return p->ptr[i];
2705 nr &= ~(CARDMAP_MASK << p->shift);
2706 p = p->ptr[i];
2707 }
2708 return NULL;
2709 }
2710
2711 static void cardmap_set(struct cardmap **pmap, unsigned int nr, void *ptr)
2712 {
2713 struct cardmap *p;
2714 int i;
2715
2716 p = *pmap;
2717 if (p == NULL || (nr >> p->shift) >= CARDMAP_WIDTH) {
2718 do {
2719 /* need a new top level */
2720 struct cardmap *np = kmalloc(sizeof(*np), GFP_KERNEL);
2721 memset(np, 0, sizeof(*np));
2722 np->ptr[0] = p;
2723 if (p != NULL) {
2724 np->shift = p->shift + CARDMAP_ORDER;
2725 p->parent = np;
2726 } else
2727 np->shift = 0;
2728 p = np;
2729 } while ((nr >> p->shift) >= CARDMAP_WIDTH);
2730 *pmap = p;
2731 }
2732 while (p->shift > 0) {
2733 i = (nr >> p->shift) & CARDMAP_MASK;
2734 if (p->ptr[i] == NULL) {
2735 struct cardmap *np = kmalloc(sizeof(*np), GFP_KERNEL);
2736 memset(np, 0, sizeof(*np));
2737 np->shift = p->shift - CARDMAP_ORDER;
2738 np->parent = p;
2739 p->ptr[i] = np;
2740 }
2741 if (ptr == NULL)
2742 clear_bit(i, &p->inuse);
2743 p = p->ptr[i];
2744 }
2745 i = nr & CARDMAP_MASK;
2746 p->ptr[i] = ptr;
2747 if (ptr != NULL)
2748 set_bit(i, &p->inuse);
2749 else
2750 clear_bit(i, &p->inuse);
2751 }
2752
2753 static unsigned int cardmap_find_first_free(struct cardmap *map)
2754 {
2755 struct cardmap *p;
2756 unsigned int nr = 0;
2757 int i;
2758
2759 if ((p = map) == NULL)
2760 return 0;
2761 for (;;) {
2762 i = find_first_zero_bit(&p->inuse, CARDMAP_WIDTH);
2763 if (i >= CARDMAP_WIDTH) {
2764 if (p->parent == NULL)
2765 return CARDMAP_WIDTH << p->shift;
2766 p = p->parent;
2767 i = (nr >> p->shift) & CARDMAP_MASK;
2768 set_bit(i, &p->inuse);
2769 continue;
2770 }
2771 nr = (nr & (~CARDMAP_MASK << p->shift)) | (i << p->shift);
2772 if (p->shift == 0 || p->ptr[i] == NULL)
2773 return nr;
2774 p = p->ptr[i];
2775 }
2776 }
2777
2778 static void cardmap_destroy(struct cardmap **pmap)
2779 {
2780 struct cardmap *p, *np;
2781 int i;
2782
2783 for (p = *pmap; p != NULL; p = np) {
2784 if (p->shift != 0) {
2785 for (i = 0; i < CARDMAP_WIDTH; ++i)
2786 if (p->ptr[i] != NULL)
2787 break;
2788 if (i < CARDMAP_WIDTH) {
2789 np = p->ptr[i];
2790 p->ptr[i] = NULL;
2791 continue;
2792 }
2793 }
2794 np = p->parent;
2795 kfree(p);
2796 }
2797 *pmap = NULL;
2798 }
2799
2800 /* Module/initialization stuff */
2801
2802 module_init(ppp_init);
2803 module_exit(ppp_cleanup);
2804
2805 EXPORT_SYMBOL(ppp_register_channel);
2806 EXPORT_SYMBOL(ppp_unregister_channel);
2807 EXPORT_SYMBOL(ppp_channel_index);
2808 EXPORT_SYMBOL(ppp_unit_number);
2809 EXPORT_SYMBOL(ppp_input);
2810 EXPORT_SYMBOL(ppp_input_error);
2811 EXPORT_SYMBOL(ppp_output_wakeup);
2812 EXPORT_SYMBOL(ppp_register_compressor);
2813 EXPORT_SYMBOL(ppp_unregister_compressor);
2814 MODULE_LICENSE("GPL");
2815 MODULE_ALIAS_CHARDEV_MAJOR(PPP_MAJOR);
2816 MODULE_ALIAS("/dev/ppp");
USB Experimental Work