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[deliverable/linux.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/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 <net/slhc_vj.h>
50 #include <asm/atomic.h>
51
52 #define PPP_VERSION "2.4.2"
53
54 /*
55 * Network protocols we support.
56 */
57 #define NP_IP 0 /* Internet Protocol V4 */
58 #define NP_IPV6 1 /* Internet Protocol V6 */
59 #define NP_IPX 2 /* IPX protocol */
60 #define NP_AT 3 /* Appletalk protocol */
61 #define NP_MPLS_UC 4 /* MPLS unicast */
62 #define NP_MPLS_MC 5 /* MPLS multicast */
63 #define NUM_NP 6 /* Number of NPs. */
64
65 #define MPHDRLEN 6 /* multilink protocol header length */
66 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */
67 #define MIN_FRAG_SIZE 64
68
69 /*
70 * An instance of /dev/ppp can be associated with either a ppp
71 * interface unit or a ppp channel. In both cases, file->private_data
72 * points to one of these.
73 */
74 struct ppp_file {
75 enum {
76 INTERFACE=1, CHANNEL
77 } kind;
78 struct sk_buff_head xq; /* pppd transmit queue */
79 struct sk_buff_head rq; /* receive queue for pppd */
80 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */
81 atomic_t refcnt; /* # refs (incl /dev/ppp attached) */
82 int hdrlen; /* space to leave for headers */
83 int index; /* interface unit / channel number */
84 int dead; /* unit/channel has been shut down */
85 };
86
87 #define PF_TO_X(pf, X) ((X *)((char *)(pf) - offsetof(X, file)))
88
89 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
90 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
91
92 #define ROUNDUP(n, x) (((n) + (x) - 1) / (x))
93
94 /*
95 * Data structure describing one ppp unit.
96 * A ppp unit corresponds to a ppp network interface device
97 * and represents a multilink bundle.
98 * It can have 0 or more ppp channels connected to it.
99 */
100 struct ppp {
101 struct ppp_file file; /* stuff for read/write/poll 0 */
102 struct file *owner; /* file that owns this unit 48 */
103 struct list_head channels; /* list of attached channels 4c */
104 int n_channels; /* how many channels are attached 54 */
105 spinlock_t rlock; /* lock for receive side 58 */
106 spinlock_t wlock; /* lock for transmit side 5c */
107 int mru; /* max receive unit 60 */
108 unsigned int flags; /* control bits 64 */
109 unsigned int xstate; /* transmit state bits 68 */
110 unsigned int rstate; /* receive state bits 6c */
111 int debug; /* debug flags 70 */
112 struct slcompress *vj; /* state for VJ header compression */
113 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
114 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
115 struct compressor *xcomp; /* transmit packet compressor 8c */
116 void *xc_state; /* its internal state 90 */
117 struct compressor *rcomp; /* receive decompressor 94 */
118 void *rc_state; /* its internal state 98 */
119 unsigned long last_xmit; /* jiffies when last pkt sent 9c */
120 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
121 struct net_device *dev; /* network interface device a4 */
122 #ifdef CONFIG_PPP_MULTILINK
123 int nxchan; /* next channel to send something on */
124 u32 nxseq; /* next sequence number to send */
125 int mrru; /* MP: max reconst. receive unit */
126 u32 nextseq; /* MP: seq no of next packet */
127 u32 minseq; /* MP: min of most recent seqnos */
128 struct sk_buff_head mrq; /* MP: receive reconstruction queue */
129 #endif /* CONFIG_PPP_MULTILINK */
130 struct net_device_stats stats; /* statistics */
131 #ifdef CONFIG_PPP_FILTER
132 struct sock_filter *pass_filter; /* filter for packets to pass */
133 struct sock_filter *active_filter;/* filter for pkts to reset idle */
134 unsigned pass_len, active_len;
135 #endif /* CONFIG_PPP_FILTER */
136 };
137
138 /*
139 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
140 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
141 * SC_MUST_COMP
142 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
143 * Bits in xstate: SC_COMP_RUN
144 */
145 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
146 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
147 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
148
149 /*
150 * Private data structure for each channel.
151 * This includes the data structure used for multilink.
152 */
153 struct channel {
154 struct ppp_file file; /* stuff for read/write/poll */
155 struct list_head list; /* link in all/new_channels list */
156 struct ppp_channel *chan; /* public channel data structure */
157 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
158 spinlock_t downl; /* protects `chan', file.xq dequeue */
159 struct ppp *ppp; /* ppp unit we're connected to */
160 struct list_head clist; /* link in list of channels per unit */
161 rwlock_t upl; /* protects `ppp' */
162 #ifdef CONFIG_PPP_MULTILINK
163 u8 avail; /* flag used in multilink stuff */
164 u8 had_frag; /* >= 1 fragments have been sent */
165 u32 lastseq; /* MP: last sequence # received */
166 #endif /* CONFIG_PPP_MULTILINK */
167 };
168
169 /*
170 * SMP locking issues:
171 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
172 * list and the ppp.n_channels field, you need to take both locks
173 * before you modify them.
174 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
175 * channel.downl.
176 */
177
178 /*
179 * A cardmap represents a mapping from unsigned integers to pointers,
180 * and provides a fast "find lowest unused number" operation.
181 * It uses a broad (32-way) tree with a bitmap at each level.
182 * It is designed to be space-efficient for small numbers of entries
183 * and time-efficient for large numbers of entries.
184 */
185 #define CARDMAP_ORDER 5
186 #define CARDMAP_WIDTH (1U << CARDMAP_ORDER)
187 #define CARDMAP_MASK (CARDMAP_WIDTH - 1)
188
189 struct cardmap {
190 int shift;
191 unsigned long inuse;
192 struct cardmap *parent;
193 void *ptr[CARDMAP_WIDTH];
194 };
195 static void *cardmap_get(struct cardmap *map, unsigned int nr);
196 static void cardmap_set(struct cardmap **map, unsigned int nr, void *ptr);
197 static unsigned int cardmap_find_first_free(struct cardmap *map);
198 static void cardmap_destroy(struct cardmap **map);
199
200 /*
201 * all_ppp_sem protects the all_ppp_units mapping.
202 * It also ensures that finding a ppp unit in the all_ppp_units map
203 * and updating its file.refcnt field is atomic.
204 */
205 static DECLARE_MUTEX(all_ppp_sem);
206 static struct cardmap *all_ppp_units;
207 static atomic_t ppp_unit_count = ATOMIC_INIT(0);
208
209 /*
210 * all_channels_lock protects all_channels and last_channel_index,
211 * and the atomicity of find a channel and updating its file.refcnt
212 * field.
213 */
214 static DEFINE_SPINLOCK(all_channels_lock);
215 static LIST_HEAD(all_channels);
216 static LIST_HEAD(new_channels);
217 static int last_channel_index;
218 static atomic_t channel_count = ATOMIC_INIT(0);
219
220 /* Get the PPP protocol number from a skb */
221 #define PPP_PROTO(skb) (((skb)->data[0] << 8) + (skb)->data[1])
222
223 /* We limit the length of ppp->file.rq to this (arbitrary) value */
224 #define PPP_MAX_RQLEN 32
225
226 /*
227 * Maximum number of multilink fragments queued up.
228 * This has to be large enough to cope with the maximum latency of
229 * the slowest channel relative to the others. Strictly it should
230 * depend on the number of channels and their characteristics.
231 */
232 #define PPP_MP_MAX_QLEN 128
233
234 /* Multilink header bits. */
235 #define B 0x80 /* this fragment begins a packet */
236 #define E 0x40 /* this fragment ends a packet */
237
238 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */
239 #define seq_before(a, b) ((s32)((a) - (b)) < 0)
240 #define seq_after(a, b) ((s32)((a) - (b)) > 0)
241
242 /* Prototypes. */
243 static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file,
244 unsigned int cmd, unsigned long arg);
245 static void ppp_xmit_process(struct ppp *ppp);
246 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
247 static void ppp_push(struct ppp *ppp);
248 static void ppp_channel_push(struct channel *pch);
249 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
250 struct channel *pch);
251 static void ppp_receive_error(struct ppp *ppp);
252 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
253 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
254 struct sk_buff *skb);
255 #ifdef CONFIG_PPP_MULTILINK
256 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
257 struct channel *pch);
258 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
259 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
260 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
261 #endif /* CONFIG_PPP_MULTILINK */
262 static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
263 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
264 static void ppp_ccp_closed(struct ppp *ppp);
265 static struct compressor *find_compressor(int type);
266 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
267 static struct ppp *ppp_create_interface(int unit, int *retp);
268 static void init_ppp_file(struct ppp_file *pf, int kind);
269 static void ppp_shutdown_interface(struct ppp *ppp);
270 static void ppp_destroy_interface(struct ppp *ppp);
271 static struct ppp *ppp_find_unit(int unit);
272 static struct channel *ppp_find_channel(int unit);
273 static int ppp_connect_channel(struct channel *pch, int unit);
274 static int ppp_disconnect_channel(struct channel *pch);
275 static void ppp_destroy_channel(struct channel *pch);
276
277 static struct class *ppp_class;
278
279 /* Translates a PPP protocol number to a NP index (NP == network protocol) */
280 static inline int proto_to_npindex(int proto)
281 {
282 switch (proto) {
283 case PPP_IP:
284 return NP_IP;
285 case PPP_IPV6:
286 return NP_IPV6;
287 case PPP_IPX:
288 return NP_IPX;
289 case PPP_AT:
290 return NP_AT;
291 case PPP_MPLS_UC:
292 return NP_MPLS_UC;
293 case PPP_MPLS_MC:
294 return NP_MPLS_MC;
295 }
296 return -EINVAL;
297 }
298
299 /* Translates an NP index into a PPP protocol number */
300 static const int npindex_to_proto[NUM_NP] = {
301 PPP_IP,
302 PPP_IPV6,
303 PPP_IPX,
304 PPP_AT,
305 PPP_MPLS_UC,
306 PPP_MPLS_MC,
307 };
308
309 /* Translates an ethertype into an NP index */
310 static inline int ethertype_to_npindex(int ethertype)
311 {
312 switch (ethertype) {
313 case ETH_P_IP:
314 return NP_IP;
315 case ETH_P_IPV6:
316 return NP_IPV6;
317 case ETH_P_IPX:
318 return NP_IPX;
319 case ETH_P_PPPTALK:
320 case ETH_P_ATALK:
321 return NP_AT;
322 case ETH_P_MPLS_UC:
323 return NP_MPLS_UC;
324 case ETH_P_MPLS_MC:
325 return NP_MPLS_MC;
326 }
327 return -1;
328 }
329
330 /* Translates an NP index into an ethertype */
331 static const int npindex_to_ethertype[NUM_NP] = {
332 ETH_P_IP,
333 ETH_P_IPV6,
334 ETH_P_IPX,
335 ETH_P_PPPTALK,
336 ETH_P_MPLS_UC,
337 ETH_P_MPLS_MC,
338 };
339
340 /*
341 * Locking shorthand.
342 */
343 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
344 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
345 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
346 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
347 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
348 ppp_recv_lock(ppp); } while (0)
349 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
350 ppp_xmit_unlock(ppp); } while (0)
351
352 /*
353 * /dev/ppp device routines.
354 * The /dev/ppp device is used by pppd to control the ppp unit.
355 * It supports the read, write, ioctl and poll functions.
356 * Open instances of /dev/ppp can be in one of three states:
357 * unattached, attached to a ppp unit, or attached to a ppp channel.
358 */
359 static int ppp_open(struct inode *inode, struct file *file)
360 {
361 /*
362 * This could (should?) be enforced by the permissions on /dev/ppp.
363 */
364 if (!capable(CAP_NET_ADMIN))
365 return -EPERM;
366 return 0;
367 }
368
369 static int ppp_release(struct inode *inode, struct file *file)
370 {
371 struct ppp_file *pf = file->private_data;
372 struct ppp *ppp;
373
374 if (pf != 0) {
375 file->private_data = NULL;
376 if (pf->kind == INTERFACE) {
377 ppp = PF_TO_PPP(pf);
378 if (file == ppp->owner)
379 ppp_shutdown_interface(ppp);
380 }
381 if (atomic_dec_and_test(&pf->refcnt)) {
382 switch (pf->kind) {
383 case INTERFACE:
384 ppp_destroy_interface(PF_TO_PPP(pf));
385 break;
386 case CHANNEL:
387 ppp_destroy_channel(PF_TO_CHANNEL(pf));
388 break;
389 }
390 }
391 }
392 return 0;
393 }
394
395 static ssize_t ppp_read(struct file *file, char __user *buf,
396 size_t count, loff_t *ppos)
397 {
398 struct ppp_file *pf = file->private_data;
399 DECLARE_WAITQUEUE(wait, current);
400 ssize_t ret;
401 struct sk_buff *skb = NULL;
402
403 ret = count;
404
405 if (pf == 0)
406 return -ENXIO;
407 add_wait_queue(&pf->rwait, &wait);
408 for (;;) {
409 set_current_state(TASK_INTERRUPTIBLE);
410 skb = skb_dequeue(&pf->rq);
411 if (skb)
412 break;
413 ret = 0;
414 if (pf->dead)
415 break;
416 if (pf->kind == INTERFACE) {
417 /*
418 * Return 0 (EOF) on an interface that has no
419 * channels connected, unless it is looping
420 * network traffic (demand mode).
421 */
422 struct ppp *ppp = PF_TO_PPP(pf);
423 if (ppp->n_channels == 0
424 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
425 break;
426 }
427 ret = -EAGAIN;
428 if (file->f_flags & O_NONBLOCK)
429 break;
430 ret = -ERESTARTSYS;
431 if (signal_pending(current))
432 break;
433 schedule();
434 }
435 set_current_state(TASK_RUNNING);
436 remove_wait_queue(&pf->rwait, &wait);
437
438 if (skb == 0)
439 goto out;
440
441 ret = -EOVERFLOW;
442 if (skb->len > count)
443 goto outf;
444 ret = -EFAULT;
445 if (copy_to_user(buf, skb->data, skb->len))
446 goto outf;
447 ret = skb->len;
448
449 outf:
450 kfree_skb(skb);
451 out:
452 return ret;
453 }
454
455 static ssize_t ppp_write(struct file *file, const char __user *buf,
456 size_t count, loff_t *ppos)
457 {
458 struct ppp_file *pf = file->private_data;
459 struct sk_buff *skb;
460 ssize_t ret;
461
462 if (pf == 0)
463 return -ENXIO;
464 ret = -ENOMEM;
465 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
466 if (skb == 0)
467 goto out;
468 skb_reserve(skb, pf->hdrlen);
469 ret = -EFAULT;
470 if (copy_from_user(skb_put(skb, count), buf, count)) {
471 kfree_skb(skb);
472 goto out;
473 }
474
475 skb_queue_tail(&pf->xq, skb);
476
477 switch (pf->kind) {
478 case INTERFACE:
479 ppp_xmit_process(PF_TO_PPP(pf));
480 break;
481 case CHANNEL:
482 ppp_channel_push(PF_TO_CHANNEL(pf));
483 break;
484 }
485
486 ret = count;
487
488 out:
489 return ret;
490 }
491
492 /* No kernel lock - fine */
493 static unsigned int ppp_poll(struct file *file, poll_table *wait)
494 {
495 struct ppp_file *pf = file->private_data;
496 unsigned int mask;
497
498 if (pf == 0)
499 return 0;
500 poll_wait(file, &pf->rwait, wait);
501 mask = POLLOUT | POLLWRNORM;
502 if (skb_peek(&pf->rq) != 0)
503 mask |= POLLIN | POLLRDNORM;
504 if (pf->dead)
505 mask |= POLLHUP;
506 else if (pf->kind == INTERFACE) {
507 /* see comment in ppp_read */
508 struct ppp *ppp = PF_TO_PPP(pf);
509 if (ppp->n_channels == 0
510 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
511 mask |= POLLIN | POLLRDNORM;
512 }
513
514 return mask;
515 }
516
517 #ifdef CONFIG_PPP_FILTER
518 static int get_filter(void __user *arg, struct sock_filter **p)
519 {
520 struct sock_fprog uprog;
521 struct sock_filter *code = NULL;
522 int len, err;
523
524 if (copy_from_user(&uprog, arg, sizeof(uprog)))
525 return -EFAULT;
526
527 if (uprog.len > BPF_MAXINSNS)
528 return -EINVAL;
529
530 if (!uprog.len) {
531 *p = NULL;
532 return 0;
533 }
534
535 len = uprog.len * sizeof(struct sock_filter);
536 code = kmalloc(len, GFP_KERNEL);
537 if (code == NULL)
538 return -ENOMEM;
539
540 if (copy_from_user(code, uprog.filter, len)) {
541 kfree(code);
542 return -EFAULT;
543 }
544
545 err = sk_chk_filter(code, uprog.len);
546 if (err) {
547 kfree(code);
548 return err;
549 }
550
551 *p = code;
552 return uprog.len;
553 }
554 #endif /* CONFIG_PPP_FILTER */
555
556 static int ppp_ioctl(struct inode *inode, struct file *file,
557 unsigned int cmd, unsigned long arg)
558 {
559 struct ppp_file *pf = file->private_data;
560 struct ppp *ppp;
561 int err = -EFAULT, val, val2, i;
562 struct ppp_idle idle;
563 struct npioctl npi;
564 int unit, cflags;
565 struct slcompress *vj;
566 void __user *argp = (void __user *)arg;
567 int __user *p = argp;
568
569 if (pf == 0)
570 return ppp_unattached_ioctl(pf, file, cmd, arg);
571
572 if (cmd == PPPIOCDETACH) {
573 /*
574 * We have to be careful here... if the file descriptor
575 * has been dup'd, we could have another process in the
576 * middle of a poll using the same file *, so we had
577 * better not free the interface data structures -
578 * instead we fail the ioctl. Even in this case, we
579 * shut down the interface if we are the owner of it.
580 * Actually, we should get rid of PPPIOCDETACH, userland
581 * (i.e. pppd) could achieve the same effect by closing
582 * this fd and reopening /dev/ppp.
583 */
584 err = -EINVAL;
585 if (pf->kind == INTERFACE) {
586 ppp = PF_TO_PPP(pf);
587 if (file == ppp->owner)
588 ppp_shutdown_interface(ppp);
589 }
590 if (atomic_read(&file->f_count) <= 2) {
591 ppp_release(inode, file);
592 err = 0;
593 } else
594 printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%d\n",
595 atomic_read(&file->f_count));
596 return err;
597 }
598
599 if (pf->kind == CHANNEL) {
600 struct channel *pch = PF_TO_CHANNEL(pf);
601 struct ppp_channel *chan;
602
603 switch (cmd) {
604 case PPPIOCCONNECT:
605 if (get_user(unit, p))
606 break;
607 err = ppp_connect_channel(pch, unit);
608 break;
609
610 case PPPIOCDISCONN:
611 err = ppp_disconnect_channel(pch);
612 break;
613
614 default:
615 down_read(&pch->chan_sem);
616 chan = pch->chan;
617 err = -ENOTTY;
618 if (chan && chan->ops->ioctl)
619 err = chan->ops->ioctl(chan, cmd, arg);
620 up_read(&pch->chan_sem);
621 }
622 return err;
623 }
624
625 if (pf->kind != INTERFACE) {
626 /* can't happen */
627 printk(KERN_ERR "PPP: not interface or channel??\n");
628 return -EINVAL;
629 }
630
631 ppp = PF_TO_PPP(pf);
632 switch (cmd) {
633 case PPPIOCSMRU:
634 if (get_user(val, p))
635 break;
636 ppp->mru = val;
637 err = 0;
638 break;
639
640 case PPPIOCSFLAGS:
641 if (get_user(val, p))
642 break;
643 ppp_lock(ppp);
644 cflags = ppp->flags & ~val;
645 ppp->flags = val & SC_FLAG_BITS;
646 ppp_unlock(ppp);
647 if (cflags & SC_CCP_OPEN)
648 ppp_ccp_closed(ppp);
649 err = 0;
650 break;
651
652 case PPPIOCGFLAGS:
653 val = ppp->flags | ppp->xstate | ppp->rstate;
654 if (put_user(val, p))
655 break;
656 err = 0;
657 break;
658
659 case PPPIOCSCOMPRESS:
660 err = ppp_set_compress(ppp, arg);
661 break;
662
663 case PPPIOCGUNIT:
664 if (put_user(ppp->file.index, p))
665 break;
666 err = 0;
667 break;
668
669 case PPPIOCSDEBUG:
670 if (get_user(val, p))
671 break;
672 ppp->debug = val;
673 err = 0;
674 break;
675
676 case PPPIOCGDEBUG:
677 if (put_user(ppp->debug, p))
678 break;
679 err = 0;
680 break;
681
682 case PPPIOCGIDLE:
683 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
684 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
685 if (copy_to_user(argp, &idle, sizeof(idle)))
686 break;
687 err = 0;
688 break;
689
690 case PPPIOCSMAXCID:
691 if (get_user(val, p))
692 break;
693 val2 = 15;
694 if ((val >> 16) != 0) {
695 val2 = val >> 16;
696 val &= 0xffff;
697 }
698 vj = slhc_init(val2+1, val+1);
699 if (vj == 0) {
700 printk(KERN_ERR "PPP: no memory (VJ compressor)\n");
701 err = -ENOMEM;
702 break;
703 }
704 ppp_lock(ppp);
705 if (ppp->vj != 0)
706 slhc_free(ppp->vj);
707 ppp->vj = vj;
708 ppp_unlock(ppp);
709 err = 0;
710 break;
711
712 case PPPIOCGNPMODE:
713 case PPPIOCSNPMODE:
714 if (copy_from_user(&npi, argp, sizeof(npi)))
715 break;
716 err = proto_to_npindex(npi.protocol);
717 if (err < 0)
718 break;
719 i = err;
720 if (cmd == PPPIOCGNPMODE) {
721 err = -EFAULT;
722 npi.mode = ppp->npmode[i];
723 if (copy_to_user(argp, &npi, sizeof(npi)))
724 break;
725 } else {
726 ppp->npmode[i] = npi.mode;
727 /* we may be able to transmit more packets now (??) */
728 netif_wake_queue(ppp->dev);
729 }
730 err = 0;
731 break;
732
733 #ifdef CONFIG_PPP_FILTER
734 case PPPIOCSPASS:
735 {
736 struct sock_filter *code;
737 err = get_filter(argp, &code);
738 if (err >= 0) {
739 ppp_lock(ppp);
740 kfree(ppp->pass_filter);
741 ppp->pass_filter = code;
742 ppp->pass_len = err;
743 ppp_unlock(ppp);
744 err = 0;
745 }
746 break;
747 }
748 case PPPIOCSACTIVE:
749 {
750 struct sock_filter *code;
751 err = get_filter(argp, &code);
752 if (err >= 0) {
753 ppp_lock(ppp);
754 kfree(ppp->active_filter);
755 ppp->active_filter = code;
756 ppp->active_len = err;
757 ppp_unlock(ppp);
758 err = 0;
759 }
760 break;
761 }
762 #endif /* CONFIG_PPP_FILTER */
763
764 #ifdef CONFIG_PPP_MULTILINK
765 case PPPIOCSMRRU:
766 if (get_user(val, p))
767 break;
768 ppp_recv_lock(ppp);
769 ppp->mrru = val;
770 ppp_recv_unlock(ppp);
771 err = 0;
772 break;
773 #endif /* CONFIG_PPP_MULTILINK */
774
775 default:
776 err = -ENOTTY;
777 }
778
779 return err;
780 }
781
782 static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file,
783 unsigned int cmd, unsigned long arg)
784 {
785 int unit, err = -EFAULT;
786 struct ppp *ppp;
787 struct channel *chan;
788 int __user *p = (int __user *)arg;
789
790 switch (cmd) {
791 case PPPIOCNEWUNIT:
792 /* Create a new ppp unit */
793 if (get_user(unit, p))
794 break;
795 ppp = ppp_create_interface(unit, &err);
796 if (ppp == 0)
797 break;
798 file->private_data = &ppp->file;
799 ppp->owner = file;
800 err = -EFAULT;
801 if (put_user(ppp->file.index, p))
802 break;
803 err = 0;
804 break;
805
806 case PPPIOCATTACH:
807 /* Attach to an existing ppp unit */
808 if (get_user(unit, p))
809 break;
810 down(&all_ppp_sem);
811 err = -ENXIO;
812 ppp = ppp_find_unit(unit);
813 if (ppp != 0) {
814 atomic_inc(&ppp->file.refcnt);
815 file->private_data = &ppp->file;
816 err = 0;
817 }
818 up(&all_ppp_sem);
819 break;
820
821 case PPPIOCATTCHAN:
822 if (get_user(unit, p))
823 break;
824 spin_lock_bh(&all_channels_lock);
825 err = -ENXIO;
826 chan = ppp_find_channel(unit);
827 if (chan != 0) {
828 atomic_inc(&chan->file.refcnt);
829 file->private_data = &chan->file;
830 err = 0;
831 }
832 spin_unlock_bh(&all_channels_lock);
833 break;
834
835 default:
836 err = -ENOTTY;
837 }
838 return err;
839 }
840
841 static struct file_operations ppp_device_fops = {
842 .owner = THIS_MODULE,
843 .read = ppp_read,
844 .write = ppp_write,
845 .poll = ppp_poll,
846 .ioctl = ppp_ioctl,
847 .open = ppp_open,
848 .release = ppp_release
849 };
850
851 #define PPP_MAJOR 108
852
853 /* Called at boot time if ppp is compiled into the kernel,
854 or at module load time (from init_module) if compiled as a module. */
855 static int __init ppp_init(void)
856 {
857 int err;
858
859 printk(KERN_INFO "PPP generic driver version " PPP_VERSION "\n");
860 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
861 if (!err) {
862 ppp_class = class_create(THIS_MODULE, "ppp");
863 if (IS_ERR(ppp_class)) {
864 err = PTR_ERR(ppp_class);
865 goto out_chrdev;
866 }
867 class_device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
868 err = devfs_mk_cdev(MKDEV(PPP_MAJOR, 0),
869 S_IFCHR|S_IRUSR|S_IWUSR, "ppp");
870 if (err)
871 goto out_class;
872 }
873
874 out:
875 if (err)
876 printk(KERN_ERR "failed to register PPP device (%d)\n", err);
877 return err;
878
879 out_class:
880 class_device_destroy(ppp_class, MKDEV(PPP_MAJOR,0));
881 class_destroy(ppp_class);
882 out_chrdev:
883 unregister_chrdev(PPP_MAJOR, "ppp");
884 goto out;
885 }
886
887 /*
888 * Network interface unit routines.
889 */
890 static int
891 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
892 {
893 struct ppp *ppp = (struct ppp *) dev->priv;
894 int npi, proto;
895 unsigned char *pp;
896
897 npi = ethertype_to_npindex(ntohs(skb->protocol));
898 if (npi < 0)
899 goto outf;
900
901 /* Drop, accept or reject the packet */
902 switch (ppp->npmode[npi]) {
903 case NPMODE_PASS:
904 break;
905 case NPMODE_QUEUE:
906 /* it would be nice to have a way to tell the network
907 system to queue this one up for later. */
908 goto outf;
909 case NPMODE_DROP:
910 case NPMODE_ERROR:
911 goto outf;
912 }
913
914 /* Put the 2-byte PPP protocol number on the front,
915 making sure there is room for the address and control fields. */
916 if (skb_headroom(skb) < PPP_HDRLEN) {
917 struct sk_buff *ns;
918
919 ns = alloc_skb(skb->len + dev->hard_header_len, GFP_ATOMIC);
920 if (ns == 0)
921 goto outf;
922 skb_reserve(ns, dev->hard_header_len);
923 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
924 kfree_skb(skb);
925 skb = ns;
926 }
927 pp = skb_push(skb, 2);
928 proto = npindex_to_proto[npi];
929 pp[0] = proto >> 8;
930 pp[1] = proto;
931
932 netif_stop_queue(dev);
933 skb_queue_tail(&ppp->file.xq, skb);
934 ppp_xmit_process(ppp);
935 return 0;
936
937 outf:
938 kfree_skb(skb);
939 ++ppp->stats.tx_dropped;
940 return 0;
941 }
942
943 static struct net_device_stats *
944 ppp_net_stats(struct net_device *dev)
945 {
946 struct ppp *ppp = (struct ppp *) dev->priv;
947
948 return &ppp->stats;
949 }
950
951 static int
952 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
953 {
954 struct ppp *ppp = dev->priv;
955 int err = -EFAULT;
956 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
957 struct ppp_stats stats;
958 struct ppp_comp_stats cstats;
959 char *vers;
960
961 switch (cmd) {
962 case SIOCGPPPSTATS:
963 ppp_get_stats(ppp, &stats);
964 if (copy_to_user(addr, &stats, sizeof(stats)))
965 break;
966 err = 0;
967 break;
968
969 case SIOCGPPPCSTATS:
970 memset(&cstats, 0, sizeof(cstats));
971 if (ppp->xc_state != 0)
972 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
973 if (ppp->rc_state != 0)
974 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
975 if (copy_to_user(addr, &cstats, sizeof(cstats)))
976 break;
977 err = 0;
978 break;
979
980 case SIOCGPPPVER:
981 vers = PPP_VERSION;
982 if (copy_to_user(addr, vers, strlen(vers) + 1))
983 break;
984 err = 0;
985 break;
986
987 default:
988 err = -EINVAL;
989 }
990
991 return err;
992 }
993
994 static void ppp_setup(struct net_device *dev)
995 {
996 dev->hard_header_len = PPP_HDRLEN;
997 dev->mtu = PPP_MTU;
998 dev->addr_len = 0;
999 dev->tx_queue_len = 3;
1000 dev->type = ARPHRD_PPP;
1001 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1002 }
1003
1004 /*
1005 * Transmit-side routines.
1006 */
1007
1008 /*
1009 * Called to do any work queued up on the transmit side
1010 * that can now be done.
1011 */
1012 static void
1013 ppp_xmit_process(struct ppp *ppp)
1014 {
1015 struct sk_buff *skb;
1016
1017 ppp_xmit_lock(ppp);
1018 if (ppp->dev != 0) {
1019 ppp_push(ppp);
1020 while (ppp->xmit_pending == 0
1021 && (skb = skb_dequeue(&ppp->file.xq)) != 0)
1022 ppp_send_frame(ppp, skb);
1023 /* If there's no work left to do, tell the core net
1024 code that we can accept some more. */
1025 if (ppp->xmit_pending == 0 && skb_peek(&ppp->file.xq) == 0)
1026 netif_wake_queue(ppp->dev);
1027 }
1028 ppp_xmit_unlock(ppp);
1029 }
1030
1031 static inline struct sk_buff *
1032 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1033 {
1034 struct sk_buff *new_skb;
1035 int len;
1036 int new_skb_size = ppp->dev->mtu +
1037 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1038 int compressor_skb_size = ppp->dev->mtu +
1039 ppp->xcomp->comp_extra + PPP_HDRLEN;
1040 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1041 if (!new_skb) {
1042 if (net_ratelimit())
1043 printk(KERN_ERR "PPP: no memory (comp pkt)\n");
1044 return NULL;
1045 }
1046 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1047 skb_reserve(new_skb,
1048 ppp->dev->hard_header_len - PPP_HDRLEN);
1049
1050 /* compressor still expects A/C bytes in hdr */
1051 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1052 new_skb->data, skb->len + 2,
1053 compressor_skb_size);
1054 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1055 kfree_skb(skb);
1056 skb = new_skb;
1057 skb_put(skb, len);
1058 skb_pull(skb, 2); /* pull off A/C bytes */
1059 } else if (len == 0) {
1060 /* didn't compress, or CCP not up yet */
1061 kfree_skb(new_skb);
1062 new_skb = skb;
1063 } else {
1064 /*
1065 * (len < 0)
1066 * MPPE requires that we do not send unencrypted
1067 * frames. The compressor will return -1 if we
1068 * should drop the frame. We cannot simply test
1069 * the compress_proto because MPPE and MPPC share
1070 * the same number.
1071 */
1072 if (net_ratelimit())
1073 printk(KERN_ERR "ppp: compressor dropped pkt\n");
1074 kfree_skb(skb);
1075 kfree_skb(new_skb);
1076 new_skb = NULL;
1077 }
1078 return new_skb;
1079 }
1080
1081 /*
1082 * Compress and send a frame.
1083 * The caller should have locked the xmit path,
1084 * and xmit_pending should be 0.
1085 */
1086 static void
1087 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1088 {
1089 int proto = PPP_PROTO(skb);
1090 struct sk_buff *new_skb;
1091 int len;
1092 unsigned char *cp;
1093
1094 if (proto < 0x8000) {
1095 #ifdef CONFIG_PPP_FILTER
1096 /* check if we should pass this packet */
1097 /* the filter instructions are constructed assuming
1098 a four-byte PPP header on each packet */
1099 *skb_push(skb, 2) = 1;
1100 if (ppp->pass_filter
1101 && sk_run_filter(skb, ppp->pass_filter,
1102 ppp->pass_len) == 0) {
1103 if (ppp->debug & 1)
1104 printk(KERN_DEBUG "PPP: outbound frame not passed\n");
1105 kfree_skb(skb);
1106 return;
1107 }
1108 /* if this packet passes the active filter, record the time */
1109 if (!(ppp->active_filter
1110 && sk_run_filter(skb, ppp->active_filter,
1111 ppp->active_len) == 0))
1112 ppp->last_xmit = jiffies;
1113 skb_pull(skb, 2);
1114 #else
1115 /* for data packets, record the time */
1116 ppp->last_xmit = jiffies;
1117 #endif /* CONFIG_PPP_FILTER */
1118 }
1119
1120 ++ppp->stats.tx_packets;
1121 ppp->stats.tx_bytes += skb->len - 2;
1122
1123 switch (proto) {
1124 case PPP_IP:
1125 if (ppp->vj == 0 || (ppp->flags & SC_COMP_TCP) == 0)
1126 break;
1127 /* try to do VJ TCP header compression */
1128 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1129 GFP_ATOMIC);
1130 if (new_skb == 0) {
1131 printk(KERN_ERR "PPP: no memory (VJ comp pkt)\n");
1132 goto drop;
1133 }
1134 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1135 cp = skb->data + 2;
1136 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1137 new_skb->data + 2, &cp,
1138 !(ppp->flags & SC_NO_TCP_CCID));
1139 if (cp == skb->data + 2) {
1140 /* didn't compress */
1141 kfree_skb(new_skb);
1142 } else {
1143 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1144 proto = PPP_VJC_COMP;
1145 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1146 } else {
1147 proto = PPP_VJC_UNCOMP;
1148 cp[0] = skb->data[2];
1149 }
1150 kfree_skb(skb);
1151 skb = new_skb;
1152 cp = skb_put(skb, len + 2);
1153 cp[0] = 0;
1154 cp[1] = proto;
1155 }
1156 break;
1157
1158 case PPP_CCP:
1159 /* peek at outbound CCP frames */
1160 ppp_ccp_peek(ppp, skb, 0);
1161 break;
1162 }
1163
1164 /* try to do packet compression */
1165 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state != 0
1166 && proto != PPP_LCP && proto != PPP_CCP) {
1167 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1168 if (net_ratelimit())
1169 printk(KERN_ERR "ppp: compression required but down - pkt dropped.\n");
1170 goto drop;
1171 }
1172 skb = pad_compress_skb(ppp, skb);
1173 if (!skb)
1174 goto drop;
1175 }
1176
1177 /*
1178 * If we are waiting for traffic (demand dialling),
1179 * queue it up for pppd to receive.
1180 */
1181 if (ppp->flags & SC_LOOP_TRAFFIC) {
1182 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1183 goto drop;
1184 skb_queue_tail(&ppp->file.rq, skb);
1185 wake_up_interruptible(&ppp->file.rwait);
1186 return;
1187 }
1188
1189 ppp->xmit_pending = skb;
1190 ppp_push(ppp);
1191 return;
1192
1193 drop:
1194 if (skb)
1195 kfree_skb(skb);
1196 ++ppp->stats.tx_errors;
1197 }
1198
1199 /*
1200 * Try to send the frame in xmit_pending.
1201 * The caller should have the xmit path locked.
1202 */
1203 static void
1204 ppp_push(struct ppp *ppp)
1205 {
1206 struct list_head *list;
1207 struct channel *pch;
1208 struct sk_buff *skb = ppp->xmit_pending;
1209
1210 if (skb == 0)
1211 return;
1212
1213 list = &ppp->channels;
1214 if (list_empty(list)) {
1215 /* nowhere to send the packet, just drop it */
1216 ppp->xmit_pending = NULL;
1217 kfree_skb(skb);
1218 return;
1219 }
1220
1221 if ((ppp->flags & SC_MULTILINK) == 0) {
1222 /* not doing multilink: send it down the first channel */
1223 list = list->next;
1224 pch = list_entry(list, struct channel, clist);
1225
1226 spin_lock_bh(&pch->downl);
1227 if (pch->chan) {
1228 if (pch->chan->ops->start_xmit(pch->chan, skb))
1229 ppp->xmit_pending = NULL;
1230 } else {
1231 /* channel got unregistered */
1232 kfree_skb(skb);
1233 ppp->xmit_pending = NULL;
1234 }
1235 spin_unlock_bh(&pch->downl);
1236 return;
1237 }
1238
1239 #ifdef CONFIG_PPP_MULTILINK
1240 /* Multilink: fragment the packet over as many links
1241 as can take the packet at the moment. */
1242 if (!ppp_mp_explode(ppp, skb))
1243 return;
1244 #endif /* CONFIG_PPP_MULTILINK */
1245
1246 ppp->xmit_pending = NULL;
1247 kfree_skb(skb);
1248 }
1249
1250 #ifdef CONFIG_PPP_MULTILINK
1251 /*
1252 * Divide a packet to be transmitted into fragments and
1253 * send them out the individual links.
1254 */
1255 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1256 {
1257 int len, fragsize;
1258 int i, bits, hdrlen, mtu;
1259 int flen;
1260 int navail, nfree;
1261 int nbigger;
1262 unsigned char *p, *q;
1263 struct list_head *list;
1264 struct channel *pch;
1265 struct sk_buff *frag;
1266 struct ppp_channel *chan;
1267
1268 nfree = 0; /* # channels which have no packet already queued */
1269 navail = 0; /* total # of usable channels (not deregistered) */
1270 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1271 i = 0;
1272 list_for_each_entry(pch, &ppp->channels, clist) {
1273 navail += pch->avail = (pch->chan != NULL);
1274 if (pch->avail) {
1275 if (skb_queue_empty(&pch->file.xq) ||
1276 !pch->had_frag) {
1277 pch->avail = 2;
1278 ++nfree;
1279 }
1280 if (!pch->had_frag && i < ppp->nxchan)
1281 ppp->nxchan = i;
1282 }
1283 ++i;
1284 }
1285
1286 /*
1287 * Don't start sending this packet unless at least half of
1288 * the channels are free. This gives much better TCP
1289 * performance if we have a lot of channels.
1290 */
1291 if (nfree == 0 || nfree < navail / 2)
1292 return 0; /* can't take now, leave it in xmit_pending */
1293
1294 /* Do protocol field compression (XXX this should be optional) */
1295 p = skb->data;
1296 len = skb->len;
1297 if (*p == 0) {
1298 ++p;
1299 --len;
1300 }
1301
1302 /*
1303 * Decide on fragment size.
1304 * We create a fragment for each free channel regardless of
1305 * how small they are (i.e. even 0 length) in order to minimize
1306 * the time that it will take to detect when a channel drops
1307 * a fragment.
1308 */
1309 fragsize = len;
1310 if (nfree > 1)
1311 fragsize = ROUNDUP(fragsize, nfree);
1312 /* nbigger channels get fragsize bytes, the rest get fragsize-1,
1313 except if nbigger==0, then they all get fragsize. */
1314 nbigger = len % nfree;
1315
1316 /* skip to the channel after the one we last used
1317 and start at that one */
1318 list = &ppp->channels;
1319 for (i = 0; i < ppp->nxchan; ++i) {
1320 list = list->next;
1321 if (list == &ppp->channels) {
1322 i = 0;
1323 break;
1324 }
1325 }
1326
1327 /* create a fragment for each channel */
1328 bits = B;
1329 while (nfree > 0 || len > 0) {
1330 list = list->next;
1331 if (list == &ppp->channels) {
1332 i = 0;
1333 continue;
1334 }
1335 pch = list_entry(list, struct channel, clist);
1336 ++i;
1337 if (!pch->avail)
1338 continue;
1339
1340 /*
1341 * Skip this channel if it has a fragment pending already and
1342 * we haven't given a fragment to all of the free channels.
1343 */
1344 if (pch->avail == 1) {
1345 if (nfree > 0)
1346 continue;
1347 } else {
1348 --nfree;
1349 pch->avail = 1;
1350 }
1351
1352 /* check the channel's mtu and whether it is still attached. */
1353 spin_lock_bh(&pch->downl);
1354 if (pch->chan == NULL) {
1355 /* can't use this channel, it's being deregistered */
1356 spin_unlock_bh(&pch->downl);
1357 pch->avail = 0;
1358 if (--navail == 0)
1359 break;
1360 continue;
1361 }
1362
1363 /*
1364 * Create a fragment for this channel of
1365 * min(max(mtu+2-hdrlen, 4), fragsize, len) bytes.
1366 * If mtu+2-hdrlen < 4, that is a ridiculously small
1367 * MTU, so we use mtu = 2 + hdrlen.
1368 */
1369 if (fragsize > len)
1370 fragsize = len;
1371 flen = fragsize;
1372 mtu = pch->chan->mtu + 2 - hdrlen;
1373 if (mtu < 4)
1374 mtu = 4;
1375 if (flen > mtu)
1376 flen = mtu;
1377 if (flen == len && nfree == 0)
1378 bits |= E;
1379 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1380 if (frag == 0)
1381 goto noskb;
1382 q = skb_put(frag, flen + hdrlen);
1383
1384 /* make the MP header */
1385 q[0] = PPP_MP >> 8;
1386 q[1] = PPP_MP;
1387 if (ppp->flags & SC_MP_XSHORTSEQ) {
1388 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1389 q[3] = ppp->nxseq;
1390 } else {
1391 q[2] = bits;
1392 q[3] = ppp->nxseq >> 16;
1393 q[4] = ppp->nxseq >> 8;
1394 q[5] = ppp->nxseq;
1395 }
1396
1397 /*
1398 * Copy the data in.
1399 * Unfortunately there is a bug in older versions of
1400 * the Linux PPP multilink reconstruction code where it
1401 * drops 0-length fragments. Therefore we make sure the
1402 * fragment has at least one byte of data. Any bytes
1403 * we add in this situation will end up as padding on the
1404 * end of the reconstructed packet.
1405 */
1406 if (flen == 0)
1407 *skb_put(frag, 1) = 0;
1408 else
1409 memcpy(q + hdrlen, p, flen);
1410
1411 /* try to send it down the channel */
1412 chan = pch->chan;
1413 if (!skb_queue_empty(&pch->file.xq) ||
1414 !chan->ops->start_xmit(chan, frag))
1415 skb_queue_tail(&pch->file.xq, frag);
1416 pch->had_frag = 1;
1417 p += flen;
1418 len -= flen;
1419 ++ppp->nxseq;
1420 bits = 0;
1421 spin_unlock_bh(&pch->downl);
1422
1423 if (--nbigger == 0 && fragsize > 0)
1424 --fragsize;
1425 }
1426 ppp->nxchan = i;
1427
1428 return 1;
1429
1430 noskb:
1431 spin_unlock_bh(&pch->downl);
1432 if (ppp->debug & 1)
1433 printk(KERN_ERR "PPP: no memory (fragment)\n");
1434 ++ppp->stats.tx_errors;
1435 ++ppp->nxseq;
1436 return 1; /* abandon the frame */
1437 }
1438 #endif /* CONFIG_PPP_MULTILINK */
1439
1440 /*
1441 * Try to send data out on a channel.
1442 */
1443 static void
1444 ppp_channel_push(struct channel *pch)
1445 {
1446 struct sk_buff *skb;
1447 struct ppp *ppp;
1448
1449 spin_lock_bh(&pch->downl);
1450 if (pch->chan != 0) {
1451 while (!skb_queue_empty(&pch->file.xq)) {
1452 skb = skb_dequeue(&pch->file.xq);
1453 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1454 /* put the packet back and try again later */
1455 skb_queue_head(&pch->file.xq, skb);
1456 break;
1457 }
1458 }
1459 } else {
1460 /* channel got deregistered */
1461 skb_queue_purge(&pch->file.xq);
1462 }
1463 spin_unlock_bh(&pch->downl);
1464 /* see if there is anything from the attached unit to be sent */
1465 if (skb_queue_empty(&pch->file.xq)) {
1466 read_lock_bh(&pch->upl);
1467 ppp = pch->ppp;
1468 if (ppp != 0)
1469 ppp_xmit_process(ppp);
1470 read_unlock_bh(&pch->upl);
1471 }
1472 }
1473
1474 /*
1475 * Receive-side routines.
1476 */
1477
1478 /* misuse a few fields of the skb for MP reconstruction */
1479 #define sequence priority
1480 #define BEbits cb[0]
1481
1482 static inline void
1483 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1484 {
1485 ppp_recv_lock(ppp);
1486 /* ppp->dev == 0 means interface is closing down */
1487 if (ppp->dev != 0)
1488 ppp_receive_frame(ppp, skb, pch);
1489 else
1490 kfree_skb(skb);
1491 ppp_recv_unlock(ppp);
1492 }
1493
1494 void
1495 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1496 {
1497 struct channel *pch = chan->ppp;
1498 int proto;
1499
1500 if (pch == 0 || skb->len == 0) {
1501 kfree_skb(skb);
1502 return;
1503 }
1504
1505 proto = PPP_PROTO(skb);
1506 read_lock_bh(&pch->upl);
1507 if (pch->ppp == 0 || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1508 /* put it on the channel queue */
1509 skb_queue_tail(&pch->file.rq, skb);
1510 /* drop old frames if queue too long */
1511 while (pch->file.rq.qlen > PPP_MAX_RQLEN
1512 && (skb = skb_dequeue(&pch->file.rq)) != 0)
1513 kfree_skb(skb);
1514 wake_up_interruptible(&pch->file.rwait);
1515 } else {
1516 ppp_do_recv(pch->ppp, skb, pch);
1517 }
1518 read_unlock_bh(&pch->upl);
1519 }
1520
1521 /* Put a 0-length skb in the receive queue as an error indication */
1522 void
1523 ppp_input_error(struct ppp_channel *chan, int code)
1524 {
1525 struct channel *pch = chan->ppp;
1526 struct sk_buff *skb;
1527
1528 if (pch == 0)
1529 return;
1530
1531 read_lock_bh(&pch->upl);
1532 if (pch->ppp != 0) {
1533 skb = alloc_skb(0, GFP_ATOMIC);
1534 if (skb != 0) {
1535 skb->len = 0; /* probably unnecessary */
1536 skb->cb[0] = code;
1537 ppp_do_recv(pch->ppp, skb, pch);
1538 }
1539 }
1540 read_unlock_bh(&pch->upl);
1541 }
1542
1543 /*
1544 * We come in here to process a received frame.
1545 * The receive side of the ppp unit is locked.
1546 */
1547 static void
1548 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1549 {
1550 if (skb->len >= 2) {
1551 #ifdef CONFIG_PPP_MULTILINK
1552 /* XXX do channel-level decompression here */
1553 if (PPP_PROTO(skb) == PPP_MP)
1554 ppp_receive_mp_frame(ppp, skb, pch);
1555 else
1556 #endif /* CONFIG_PPP_MULTILINK */
1557 ppp_receive_nonmp_frame(ppp, skb);
1558 return;
1559 }
1560
1561 if (skb->len > 0)
1562 /* note: a 0-length skb is used as an error indication */
1563 ++ppp->stats.rx_length_errors;
1564
1565 kfree_skb(skb);
1566 ppp_receive_error(ppp);
1567 }
1568
1569 static void
1570 ppp_receive_error(struct ppp *ppp)
1571 {
1572 ++ppp->stats.rx_errors;
1573 if (ppp->vj != 0)
1574 slhc_toss(ppp->vj);
1575 }
1576
1577 static void
1578 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1579 {
1580 struct sk_buff *ns;
1581 int proto, len, npi;
1582
1583 /*
1584 * Decompress the frame, if compressed.
1585 * Note that some decompressors need to see uncompressed frames
1586 * that come in as well as compressed frames.
1587 */
1588 if (ppp->rc_state != 0 && (ppp->rstate & SC_DECOMP_RUN)
1589 && (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1590 skb = ppp_decompress_frame(ppp, skb);
1591
1592 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1593 goto err;
1594
1595 proto = PPP_PROTO(skb);
1596 switch (proto) {
1597 case PPP_VJC_COMP:
1598 /* decompress VJ compressed packets */
1599 if (ppp->vj == 0 || (ppp->flags & SC_REJ_COMP_TCP))
1600 goto err;
1601
1602 if (skb_tailroom(skb) < 124) {
1603 /* copy to a new sk_buff with more tailroom */
1604 ns = dev_alloc_skb(skb->len + 128);
1605 if (ns == 0) {
1606 printk(KERN_ERR"PPP: no memory (VJ decomp)\n");
1607 goto err;
1608 }
1609 skb_reserve(ns, 2);
1610 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1611 kfree_skb(skb);
1612 skb = ns;
1613 }
1614 else if (!pskb_may_pull(skb, skb->len))
1615 goto err;
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 skb_pull(skb, 2); /* chop off protocol */
1696 skb->dev = ppp->dev;
1697 skb->protocol = htons(npindex_to_ethertype[npi]);
1698 skb->mac.raw = skb->data;
1699 netif_rx(skb);
1700 ppp->dev->last_rx = jiffies;
1701 }
1702 }
1703 return;
1704
1705 err:
1706 kfree_skb(skb);
1707 ppp_receive_error(ppp);
1708 }
1709
1710 static struct sk_buff *
1711 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1712 {
1713 int proto = PPP_PROTO(skb);
1714 struct sk_buff *ns;
1715 int len;
1716
1717 /* Until we fix all the decompressor's need to make sure
1718 * data portion is linear.
1719 */
1720 if (!pskb_may_pull(skb, skb->len))
1721 goto err;
1722
1723 if (proto == PPP_COMP) {
1724 ns = dev_alloc_skb(ppp->mru + PPP_HDRLEN);
1725 if (ns == 0) {
1726 printk(KERN_ERR "ppp_decompress_frame: no memory\n");
1727 goto err;
1728 }
1729 /* the decompressor still expects the A/C bytes in the hdr */
1730 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1731 skb->len + 2, ns->data, ppp->mru + PPP_HDRLEN);
1732 if (len < 0) {
1733 /* Pass the compressed frame to pppd as an
1734 error indication. */
1735 if (len == DECOMP_FATALERROR)
1736 ppp->rstate |= SC_DC_FERROR;
1737 kfree_skb(ns);
1738 goto err;
1739 }
1740
1741 kfree_skb(skb);
1742 skb = ns;
1743 skb_put(skb, len);
1744 skb_pull(skb, 2); /* pull off the A/C bytes */
1745
1746 } else {
1747 /* Uncompressed frame - pass to decompressor so it
1748 can update its dictionary if necessary. */
1749 if (ppp->rcomp->incomp)
1750 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1751 skb->len + 2);
1752 }
1753
1754 return skb;
1755
1756 err:
1757 ppp->rstate |= SC_DC_ERROR;
1758 ppp_receive_error(ppp);
1759 return skb;
1760 }
1761
1762 #ifdef CONFIG_PPP_MULTILINK
1763 /*
1764 * Receive a multilink frame.
1765 * We put it on the reconstruction queue and then pull off
1766 * as many completed frames as we can.
1767 */
1768 static void
1769 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1770 {
1771 u32 mask, seq;
1772 struct channel *ch;
1773 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1774
1775 if (!pskb_may_pull(skb, mphdrlen) || ppp->mrru == 0)
1776 goto err; /* no good, throw it away */
1777
1778 /* Decode sequence number and begin/end bits */
1779 if (ppp->flags & SC_MP_SHORTSEQ) {
1780 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1781 mask = 0xfff;
1782 } else {
1783 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1784 mask = 0xffffff;
1785 }
1786 skb->BEbits = skb->data[2];
1787 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
1788
1789 /*
1790 * Do protocol ID decompression on the first fragment of each packet.
1791 */
1792 if ((skb->BEbits & B) && (skb->data[0] & 1))
1793 *skb_push(skb, 1) = 0;
1794
1795 /*
1796 * Expand sequence number to 32 bits, making it as close
1797 * as possible to ppp->minseq.
1798 */
1799 seq |= ppp->minseq & ~mask;
1800 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
1801 seq += mask + 1;
1802 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
1803 seq -= mask + 1; /* should never happen */
1804 skb->sequence = seq;
1805 pch->lastseq = seq;
1806
1807 /*
1808 * If this packet comes before the next one we were expecting,
1809 * drop it.
1810 */
1811 if (seq_before(seq, ppp->nextseq)) {
1812 kfree_skb(skb);
1813 ++ppp->stats.rx_dropped;
1814 ppp_receive_error(ppp);
1815 return;
1816 }
1817
1818 /*
1819 * Reevaluate minseq, the minimum over all channels of the
1820 * last sequence number received on each channel. Because of
1821 * the increasing sequence number rule, we know that any fragment
1822 * before `minseq' which hasn't arrived is never going to arrive.
1823 * The list of channels can't change because we have the receive
1824 * side of the ppp unit locked.
1825 */
1826 list_for_each_entry(ch, &ppp->channels, clist) {
1827 if (seq_before(ch->lastseq, seq))
1828 seq = ch->lastseq;
1829 }
1830 if (seq_before(ppp->minseq, seq))
1831 ppp->minseq = seq;
1832
1833 /* Put the fragment on the reconstruction queue */
1834 ppp_mp_insert(ppp, skb);
1835
1836 /* If the queue is getting long, don't wait any longer for packets
1837 before the start of the queue. */
1838 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN
1839 && seq_before(ppp->minseq, ppp->mrq.next->sequence))
1840 ppp->minseq = ppp->mrq.next->sequence;
1841
1842 /* Pull completed packets off the queue and receive them. */
1843 while ((skb = ppp_mp_reconstruct(ppp)) != 0)
1844 ppp_receive_nonmp_frame(ppp, skb);
1845
1846 return;
1847
1848 err:
1849 kfree_skb(skb);
1850 ppp_receive_error(ppp);
1851 }
1852
1853 /*
1854 * Insert a fragment on the MP reconstruction queue.
1855 * The queue is ordered by increasing sequence number.
1856 */
1857 static void
1858 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
1859 {
1860 struct sk_buff *p;
1861 struct sk_buff_head *list = &ppp->mrq;
1862 u32 seq = skb->sequence;
1863
1864 /* N.B. we don't need to lock the list lock because we have the
1865 ppp unit receive-side lock. */
1866 for (p = list->next; p != (struct sk_buff *)list; p = p->next)
1867 if (seq_before(seq, p->sequence))
1868 break;
1869 __skb_insert(skb, p->prev, p, list);
1870 }
1871
1872 /*
1873 * Reconstruct a packet from the MP fragment queue.
1874 * We go through increasing sequence numbers until we find a
1875 * complete packet, or we get to the sequence number for a fragment
1876 * which hasn't arrived but might still do so.
1877 */
1878 struct sk_buff *
1879 ppp_mp_reconstruct(struct ppp *ppp)
1880 {
1881 u32 seq = ppp->nextseq;
1882 u32 minseq = ppp->minseq;
1883 struct sk_buff_head *list = &ppp->mrq;
1884 struct sk_buff *p, *next;
1885 struct sk_buff *head, *tail;
1886 struct sk_buff *skb = NULL;
1887 int lost = 0, len = 0;
1888
1889 if (ppp->mrru == 0) /* do nothing until mrru is set */
1890 return NULL;
1891 head = list->next;
1892 tail = NULL;
1893 for (p = head; p != (struct sk_buff *) list; p = next) {
1894 next = p->next;
1895 if (seq_before(p->sequence, seq)) {
1896 /* this can't happen, anyway ignore the skb */
1897 printk(KERN_ERR "ppp_mp_reconstruct bad seq %u < %u\n",
1898 p->sequence, seq);
1899 head = next;
1900 continue;
1901 }
1902 if (p->sequence != seq) {
1903 /* Fragment `seq' is missing. If it is after
1904 minseq, it might arrive later, so stop here. */
1905 if (seq_after(seq, minseq))
1906 break;
1907 /* Fragment `seq' is lost, keep going. */
1908 lost = 1;
1909 seq = seq_before(minseq, p->sequence)?
1910 minseq + 1: p->sequence;
1911 next = p;
1912 continue;
1913 }
1914
1915 /*
1916 * At this point we know that all the fragments from
1917 * ppp->nextseq to seq are either present or lost.
1918 * Also, there are no complete packets in the queue
1919 * that have no missing fragments and end before this
1920 * fragment.
1921 */
1922
1923 /* B bit set indicates this fragment starts a packet */
1924 if (p->BEbits & B) {
1925 head = p;
1926 lost = 0;
1927 len = 0;
1928 }
1929
1930 len += p->len;
1931
1932 /* Got a complete packet yet? */
1933 if (lost == 0 && (p->BEbits & E) && (head->BEbits & B)) {
1934 if (len > ppp->mrru + 2) {
1935 ++ppp->stats.rx_length_errors;
1936 printk(KERN_DEBUG "PPP: reconstructed packet"
1937 " is too long (%d)\n", len);
1938 } else if (p == head) {
1939 /* fragment is complete packet - reuse skb */
1940 tail = p;
1941 skb = skb_get(p);
1942 break;
1943 } else if ((skb = dev_alloc_skb(len)) == NULL) {
1944 ++ppp->stats.rx_missed_errors;
1945 printk(KERN_DEBUG "PPP: no memory for "
1946 "reconstructed packet");
1947 } else {
1948 tail = p;
1949 break;
1950 }
1951 ppp->nextseq = seq + 1;
1952 }
1953
1954 /*
1955 * If this is the ending fragment of a packet,
1956 * and we haven't found a complete valid packet yet,
1957 * we can discard up to and including this fragment.
1958 */
1959 if (p->BEbits & E)
1960 head = next;
1961
1962 ++seq;
1963 }
1964
1965 /* If we have a complete packet, copy it all into one skb. */
1966 if (tail != NULL) {
1967 /* If we have discarded any fragments,
1968 signal a receive error. */
1969 if (head->sequence != ppp->nextseq) {
1970 if (ppp->debug & 1)
1971 printk(KERN_DEBUG " missed pkts %u..%u\n",
1972 ppp->nextseq, head->sequence-1);
1973 ++ppp->stats.rx_dropped;
1974 ppp_receive_error(ppp);
1975 }
1976
1977 if (head != tail)
1978 /* copy to a single skb */
1979 for (p = head; p != tail->next; p = p->next)
1980 skb_copy_bits(p, 0, skb_put(skb, p->len), p->len);
1981 ppp->nextseq = tail->sequence + 1;
1982 head = tail->next;
1983 }
1984
1985 /* Discard all the skbuffs that we have copied the data out of
1986 or that we can't use. */
1987 while ((p = list->next) != head) {
1988 __skb_unlink(p, list);
1989 kfree_skb(p);
1990 }
1991
1992 return skb;
1993 }
1994 #endif /* CONFIG_PPP_MULTILINK */
1995
1996 /*
1997 * Channel interface.
1998 */
1999
2000 /*
2001 * Create a new, unattached ppp channel.
2002 */
2003 int
2004 ppp_register_channel(struct ppp_channel *chan)
2005 {
2006 struct channel *pch;
2007
2008 pch = kmalloc(sizeof(struct channel), GFP_KERNEL);
2009 if (pch == 0)
2010 return -ENOMEM;
2011 memset(pch, 0, sizeof(struct channel));
2012 pch->ppp = NULL;
2013 pch->chan = chan;
2014 chan->ppp = pch;
2015 init_ppp_file(&pch->file, CHANNEL);
2016 pch->file.hdrlen = chan->hdrlen;
2017 #ifdef CONFIG_PPP_MULTILINK
2018 pch->lastseq = -1;
2019 #endif /* CONFIG_PPP_MULTILINK */
2020 init_rwsem(&pch->chan_sem);
2021 spin_lock_init(&pch->downl);
2022 rwlock_init(&pch->upl);
2023 spin_lock_bh(&all_channels_lock);
2024 pch->file.index = ++last_channel_index;
2025 list_add(&pch->list, &new_channels);
2026 atomic_inc(&channel_count);
2027 spin_unlock_bh(&all_channels_lock);
2028 return 0;
2029 }
2030
2031 /*
2032 * Return the index of a channel.
2033 */
2034 int ppp_channel_index(struct ppp_channel *chan)
2035 {
2036 struct channel *pch = chan->ppp;
2037
2038 if (pch != 0)
2039 return pch->file.index;
2040 return -1;
2041 }
2042
2043 /*
2044 * Return the PPP unit number to which a channel is connected.
2045 */
2046 int ppp_unit_number(struct ppp_channel *chan)
2047 {
2048 struct channel *pch = chan->ppp;
2049 int unit = -1;
2050
2051 if (pch != 0) {
2052 read_lock_bh(&pch->upl);
2053 if (pch->ppp != 0)
2054 unit = pch->ppp->file.index;
2055 read_unlock_bh(&pch->upl);
2056 }
2057 return unit;
2058 }
2059
2060 /*
2061 * Disconnect a channel from the generic layer.
2062 * This must be called in process context.
2063 */
2064 void
2065 ppp_unregister_channel(struct ppp_channel *chan)
2066 {
2067 struct channel *pch = chan->ppp;
2068
2069 if (pch == 0)
2070 return; /* should never happen */
2071 chan->ppp = NULL;
2072
2073 /*
2074 * This ensures that we have returned from any calls into the
2075 * the channel's start_xmit or ioctl routine before we proceed.
2076 */
2077 down_write(&pch->chan_sem);
2078 spin_lock_bh(&pch->downl);
2079 pch->chan = NULL;
2080 spin_unlock_bh(&pch->downl);
2081 up_write(&pch->chan_sem);
2082 ppp_disconnect_channel(pch);
2083 spin_lock_bh(&all_channels_lock);
2084 list_del(&pch->list);
2085 spin_unlock_bh(&all_channels_lock);
2086 pch->file.dead = 1;
2087 wake_up_interruptible(&pch->file.rwait);
2088 if (atomic_dec_and_test(&pch->file.refcnt))
2089 ppp_destroy_channel(pch);
2090 }
2091
2092 /*
2093 * Callback from a channel when it can accept more to transmit.
2094 * This should be called at BH/softirq level, not interrupt level.
2095 */
2096 void
2097 ppp_output_wakeup(struct ppp_channel *chan)
2098 {
2099 struct channel *pch = chan->ppp;
2100
2101 if (pch == 0)
2102 return;
2103 ppp_channel_push(pch);
2104 }
2105
2106 /*
2107 * Compression control.
2108 */
2109
2110 /* Process the PPPIOCSCOMPRESS ioctl. */
2111 static int
2112 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2113 {
2114 int err;
2115 struct compressor *cp, *ocomp;
2116 struct ppp_option_data data;
2117 void *state, *ostate;
2118 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2119
2120 err = -EFAULT;
2121 if (copy_from_user(&data, (void __user *) arg, sizeof(data))
2122 || (data.length <= CCP_MAX_OPTION_LENGTH
2123 && copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2124 goto out;
2125 err = -EINVAL;
2126 if (data.length > CCP_MAX_OPTION_LENGTH
2127 || ccp_option[1] < 2 || ccp_option[1] > data.length)
2128 goto out;
2129
2130 cp = find_compressor(ccp_option[0]);
2131 #ifdef CONFIG_KMOD
2132 if (cp == 0) {
2133 request_module("ppp-compress-%d", ccp_option[0]);
2134 cp = find_compressor(ccp_option[0]);
2135 }
2136 #endif /* CONFIG_KMOD */
2137 if (cp == 0)
2138 goto out;
2139
2140 err = -ENOBUFS;
2141 if (data.transmit) {
2142 state = cp->comp_alloc(ccp_option, data.length);
2143 if (state != 0) {
2144 ppp_xmit_lock(ppp);
2145 ppp->xstate &= ~SC_COMP_RUN;
2146 ocomp = ppp->xcomp;
2147 ostate = ppp->xc_state;
2148 ppp->xcomp = cp;
2149 ppp->xc_state = state;
2150 ppp_xmit_unlock(ppp);
2151 if (ostate != 0) {
2152 ocomp->comp_free(ostate);
2153 module_put(ocomp->owner);
2154 }
2155 err = 0;
2156 } else
2157 module_put(cp->owner);
2158
2159 } else {
2160 state = cp->decomp_alloc(ccp_option, data.length);
2161 if (state != 0) {
2162 ppp_recv_lock(ppp);
2163 ppp->rstate &= ~SC_DECOMP_RUN;
2164 ocomp = ppp->rcomp;
2165 ostate = ppp->rc_state;
2166 ppp->rcomp = cp;
2167 ppp->rc_state = state;
2168 ppp_recv_unlock(ppp);
2169 if (ostate != 0) {
2170 ocomp->decomp_free(ostate);
2171 module_put(ocomp->owner);
2172 }
2173 err = 0;
2174 } else
2175 module_put(cp->owner);
2176 }
2177
2178 out:
2179 return err;
2180 }
2181
2182 /*
2183 * Look at a CCP packet and update our state accordingly.
2184 * We assume the caller has the xmit or recv path locked.
2185 */
2186 static void
2187 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2188 {
2189 unsigned char *dp;
2190 int len;
2191
2192 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2193 return; /* no header */
2194 dp = skb->data + 2;
2195
2196 switch (CCP_CODE(dp)) {
2197 case CCP_CONFREQ:
2198
2199 /* A ConfReq starts negotiation of compression
2200 * in one direction of transmission,
2201 * and hence brings it down...but which way?
2202 *
2203 * Remember:
2204 * A ConfReq indicates what the sender would like to receive
2205 */
2206 if(inbound)
2207 /* He is proposing what I should send */
2208 ppp->xstate &= ~SC_COMP_RUN;
2209 else
2210 /* I am proposing to what he should send */
2211 ppp->rstate &= ~SC_DECOMP_RUN;
2212
2213 break;
2214
2215 case CCP_TERMREQ:
2216 case CCP_TERMACK:
2217 /*
2218 * CCP is going down, both directions of transmission
2219 */
2220 ppp->rstate &= ~SC_DECOMP_RUN;
2221 ppp->xstate &= ~SC_COMP_RUN;
2222 break;
2223
2224 case CCP_CONFACK:
2225 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2226 break;
2227 len = CCP_LENGTH(dp);
2228 if (!pskb_may_pull(skb, len + 2))
2229 return; /* too short */
2230 dp += CCP_HDRLEN;
2231 len -= CCP_HDRLEN;
2232 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2233 break;
2234 if (inbound) {
2235 /* we will start receiving compressed packets */
2236 if (ppp->rc_state == 0)
2237 break;
2238 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2239 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2240 ppp->rstate |= SC_DECOMP_RUN;
2241 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2242 }
2243 } else {
2244 /* we will soon start sending compressed packets */
2245 if (ppp->xc_state == 0)
2246 break;
2247 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2248 ppp->file.index, 0, ppp->debug))
2249 ppp->xstate |= SC_COMP_RUN;
2250 }
2251 break;
2252
2253 case CCP_RESETACK:
2254 /* reset the [de]compressor */
2255 if ((ppp->flags & SC_CCP_UP) == 0)
2256 break;
2257 if (inbound) {
2258 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2259 ppp->rcomp->decomp_reset(ppp->rc_state);
2260 ppp->rstate &= ~SC_DC_ERROR;
2261 }
2262 } else {
2263 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2264 ppp->xcomp->comp_reset(ppp->xc_state);
2265 }
2266 break;
2267 }
2268 }
2269
2270 /* Free up compression resources. */
2271 static void
2272 ppp_ccp_closed(struct ppp *ppp)
2273 {
2274 void *xstate, *rstate;
2275 struct compressor *xcomp, *rcomp;
2276
2277 ppp_lock(ppp);
2278 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2279 ppp->xstate = 0;
2280 xcomp = ppp->xcomp;
2281 xstate = ppp->xc_state;
2282 ppp->xc_state = NULL;
2283 ppp->rstate = 0;
2284 rcomp = ppp->rcomp;
2285 rstate = ppp->rc_state;
2286 ppp->rc_state = NULL;
2287 ppp_unlock(ppp);
2288
2289 if (xstate) {
2290 xcomp->comp_free(xstate);
2291 module_put(xcomp->owner);
2292 }
2293 if (rstate) {
2294 rcomp->decomp_free(rstate);
2295 module_put(rcomp->owner);
2296 }
2297 }
2298
2299 /* List of compressors. */
2300 static LIST_HEAD(compressor_list);
2301 static DEFINE_SPINLOCK(compressor_list_lock);
2302
2303 struct compressor_entry {
2304 struct list_head list;
2305 struct compressor *comp;
2306 };
2307
2308 static struct compressor_entry *
2309 find_comp_entry(int proto)
2310 {
2311 struct compressor_entry *ce;
2312
2313 list_for_each_entry(ce, &compressor_list, list) {
2314 if (ce->comp->compress_proto == proto)
2315 return ce;
2316 }
2317 return NULL;
2318 }
2319
2320 /* Register a compressor */
2321 int
2322 ppp_register_compressor(struct compressor *cp)
2323 {
2324 struct compressor_entry *ce;
2325 int ret;
2326 spin_lock(&compressor_list_lock);
2327 ret = -EEXIST;
2328 if (find_comp_entry(cp->compress_proto) != 0)
2329 goto out;
2330 ret = -ENOMEM;
2331 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2332 if (ce == 0)
2333 goto out;
2334 ret = 0;
2335 ce->comp = cp;
2336 list_add(&ce->list, &compressor_list);
2337 out:
2338 spin_unlock(&compressor_list_lock);
2339 return ret;
2340 }
2341
2342 /* Unregister a compressor */
2343 void
2344 ppp_unregister_compressor(struct compressor *cp)
2345 {
2346 struct compressor_entry *ce;
2347
2348 spin_lock(&compressor_list_lock);
2349 ce = find_comp_entry(cp->compress_proto);
2350 if (ce != 0 && ce->comp == cp) {
2351 list_del(&ce->list);
2352 kfree(ce);
2353 }
2354 spin_unlock(&compressor_list_lock);
2355 }
2356
2357 /* Find a compressor. */
2358 static struct compressor *
2359 find_compressor(int type)
2360 {
2361 struct compressor_entry *ce;
2362 struct compressor *cp = NULL;
2363
2364 spin_lock(&compressor_list_lock);
2365 ce = find_comp_entry(type);
2366 if (ce != 0) {
2367 cp = ce->comp;
2368 if (!try_module_get(cp->owner))
2369 cp = NULL;
2370 }
2371 spin_unlock(&compressor_list_lock);
2372 return cp;
2373 }
2374
2375 /*
2376 * Miscelleneous stuff.
2377 */
2378
2379 static void
2380 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2381 {
2382 struct slcompress *vj = ppp->vj;
2383
2384 memset(st, 0, sizeof(*st));
2385 st->p.ppp_ipackets = ppp->stats.rx_packets;
2386 st->p.ppp_ierrors = ppp->stats.rx_errors;
2387 st->p.ppp_ibytes = ppp->stats.rx_bytes;
2388 st->p.ppp_opackets = ppp->stats.tx_packets;
2389 st->p.ppp_oerrors = ppp->stats.tx_errors;
2390 st->p.ppp_obytes = ppp->stats.tx_bytes;
2391 if (vj == 0)
2392 return;
2393 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2394 st->vj.vjs_compressed = vj->sls_o_compressed;
2395 st->vj.vjs_searches = vj->sls_o_searches;
2396 st->vj.vjs_misses = vj->sls_o_misses;
2397 st->vj.vjs_errorin = vj->sls_i_error;
2398 st->vj.vjs_tossed = vj->sls_i_tossed;
2399 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2400 st->vj.vjs_compressedin = vj->sls_i_compressed;
2401 }
2402
2403 /*
2404 * Stuff for handling the lists of ppp units and channels
2405 * and for initialization.
2406 */
2407
2408 /*
2409 * Create a new ppp interface unit. Fails if it can't allocate memory
2410 * or if there is already a unit with the requested number.
2411 * unit == -1 means allocate a new number.
2412 */
2413 static struct ppp *
2414 ppp_create_interface(int unit, int *retp)
2415 {
2416 struct ppp *ppp;
2417 struct net_device *dev = NULL;
2418 int ret = -ENOMEM;
2419 int i;
2420
2421 ppp = kmalloc(sizeof(struct ppp), GFP_KERNEL);
2422 if (!ppp)
2423 goto out;
2424 dev = alloc_netdev(0, "", ppp_setup);
2425 if (!dev)
2426 goto out1;
2427 memset(ppp, 0, sizeof(struct ppp));
2428
2429 ppp->mru = PPP_MRU;
2430 init_ppp_file(&ppp->file, INTERFACE);
2431 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2432 for (i = 0; i < NUM_NP; ++i)
2433 ppp->npmode[i] = NPMODE_PASS;
2434 INIT_LIST_HEAD(&ppp->channels);
2435 spin_lock_init(&ppp->rlock);
2436 spin_lock_init(&ppp->wlock);
2437 #ifdef CONFIG_PPP_MULTILINK
2438 ppp->minseq = -1;
2439 skb_queue_head_init(&ppp->mrq);
2440 #endif /* CONFIG_PPP_MULTILINK */
2441 ppp->dev = dev;
2442 dev->priv = ppp;
2443
2444 dev->hard_start_xmit = ppp_start_xmit;
2445 dev->get_stats = ppp_net_stats;
2446 dev->do_ioctl = ppp_net_ioctl;
2447
2448 ret = -EEXIST;
2449 down(&all_ppp_sem);
2450 if (unit < 0)
2451 unit = cardmap_find_first_free(all_ppp_units);
2452 else if (cardmap_get(all_ppp_units, unit) != NULL)
2453 goto out2; /* unit already exists */
2454
2455 /* Initialize the new ppp unit */
2456 ppp->file.index = unit;
2457 sprintf(dev->name, "ppp%d", unit);
2458
2459 ret = register_netdev(dev);
2460 if (ret != 0) {
2461 printk(KERN_ERR "PPP: couldn't register device %s (%d)\n",
2462 dev->name, ret);
2463 goto out2;
2464 }
2465
2466 atomic_inc(&ppp_unit_count);
2467 cardmap_set(&all_ppp_units, unit, ppp);
2468 up(&all_ppp_sem);
2469 *retp = 0;
2470 return ppp;
2471
2472 out2:
2473 up(&all_ppp_sem);
2474 free_netdev(dev);
2475 out1:
2476 kfree(ppp);
2477 out:
2478 *retp = ret;
2479 return NULL;
2480 }
2481
2482 /*
2483 * Initialize a ppp_file structure.
2484 */
2485 static void
2486 init_ppp_file(struct ppp_file *pf, int kind)
2487 {
2488 pf->kind = kind;
2489 skb_queue_head_init(&pf->xq);
2490 skb_queue_head_init(&pf->rq);
2491 atomic_set(&pf->refcnt, 1);
2492 init_waitqueue_head(&pf->rwait);
2493 }
2494
2495 /*
2496 * Take down a ppp interface unit - called when the owning file
2497 * (the one that created the unit) is closed or detached.
2498 */
2499 static void ppp_shutdown_interface(struct ppp *ppp)
2500 {
2501 struct net_device *dev;
2502
2503 down(&all_ppp_sem);
2504 ppp_lock(ppp);
2505 dev = ppp->dev;
2506 ppp->dev = NULL;
2507 ppp_unlock(ppp);
2508 /* This will call dev_close() for us. */
2509 if (dev) {
2510 unregister_netdev(dev);
2511 free_netdev(dev);
2512 }
2513 cardmap_set(&all_ppp_units, ppp->file.index, NULL);
2514 ppp->file.dead = 1;
2515 ppp->owner = NULL;
2516 wake_up_interruptible(&ppp->file.rwait);
2517 up(&all_ppp_sem);
2518 }
2519
2520 /*
2521 * Free the memory used by a ppp unit. This is only called once
2522 * there are no channels connected to the unit and no file structs
2523 * that reference the unit.
2524 */
2525 static void ppp_destroy_interface(struct ppp *ppp)
2526 {
2527 atomic_dec(&ppp_unit_count);
2528
2529 if (!ppp->file.dead || ppp->n_channels) {
2530 /* "can't happen" */
2531 printk(KERN_ERR "ppp: destroying ppp struct %p but dead=%d "
2532 "n_channels=%d !\n", ppp, ppp->file.dead,
2533 ppp->n_channels);
2534 return;
2535 }
2536
2537 ppp_ccp_closed(ppp);
2538 if (ppp->vj) {
2539 slhc_free(ppp->vj);
2540 ppp->vj = NULL;
2541 }
2542 skb_queue_purge(&ppp->file.xq);
2543 skb_queue_purge(&ppp->file.rq);
2544 #ifdef CONFIG_PPP_MULTILINK
2545 skb_queue_purge(&ppp->mrq);
2546 #endif /* CONFIG_PPP_MULTILINK */
2547 #ifdef CONFIG_PPP_FILTER
2548 kfree(ppp->pass_filter);
2549 ppp->pass_filter = NULL;
2550 kfree(ppp->active_filter);
2551 ppp->active_filter = NULL;
2552 #endif /* CONFIG_PPP_FILTER */
2553
2554 kfree(ppp);
2555 }
2556
2557 /*
2558 * Locate an existing ppp unit.
2559 * The caller should have locked the all_ppp_sem.
2560 */
2561 static struct ppp *
2562 ppp_find_unit(int unit)
2563 {
2564 return cardmap_get(all_ppp_units, unit);
2565 }
2566
2567 /*
2568 * Locate an existing ppp channel.
2569 * The caller should have locked the all_channels_lock.
2570 * First we look in the new_channels list, then in the
2571 * all_channels list. If found in the new_channels list,
2572 * we move it to the all_channels list. This is for speed
2573 * when we have a lot of channels in use.
2574 */
2575 static struct channel *
2576 ppp_find_channel(int unit)
2577 {
2578 struct channel *pch;
2579
2580 list_for_each_entry(pch, &new_channels, list) {
2581 if (pch->file.index == unit) {
2582 list_del(&pch->list);
2583 list_add(&pch->list, &all_channels);
2584 return pch;
2585 }
2586 }
2587 list_for_each_entry(pch, &all_channels, list) {
2588 if (pch->file.index == unit)
2589 return pch;
2590 }
2591 return NULL;
2592 }
2593
2594 /*
2595 * Connect a PPP channel to a PPP interface unit.
2596 */
2597 static int
2598 ppp_connect_channel(struct channel *pch, int unit)
2599 {
2600 struct ppp *ppp;
2601 int ret = -ENXIO;
2602 int hdrlen;
2603
2604 down(&all_ppp_sem);
2605 ppp = ppp_find_unit(unit);
2606 if (ppp == 0)
2607 goto out;
2608 write_lock_bh(&pch->upl);
2609 ret = -EINVAL;
2610 if (pch->ppp != 0)
2611 goto outl;
2612
2613 ppp_lock(ppp);
2614 if (pch->file.hdrlen > ppp->file.hdrlen)
2615 ppp->file.hdrlen = pch->file.hdrlen;
2616 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2617 if (ppp->dev && hdrlen > ppp->dev->hard_header_len)
2618 ppp->dev->hard_header_len = hdrlen;
2619 list_add_tail(&pch->clist, &ppp->channels);
2620 ++ppp->n_channels;
2621 pch->ppp = ppp;
2622 atomic_inc(&ppp->file.refcnt);
2623 ppp_unlock(ppp);
2624 ret = 0;
2625
2626 outl:
2627 write_unlock_bh(&pch->upl);
2628 out:
2629 up(&all_ppp_sem);
2630 return ret;
2631 }
2632
2633 /*
2634 * Disconnect a channel from its ppp unit.
2635 */
2636 static int
2637 ppp_disconnect_channel(struct channel *pch)
2638 {
2639 struct ppp *ppp;
2640 int err = -EINVAL;
2641
2642 write_lock_bh(&pch->upl);
2643 ppp = pch->ppp;
2644 pch->ppp = NULL;
2645 write_unlock_bh(&pch->upl);
2646 if (ppp != 0) {
2647 /* remove it from the ppp unit's list */
2648 ppp_lock(ppp);
2649 list_del(&pch->clist);
2650 if (--ppp->n_channels == 0)
2651 wake_up_interruptible(&ppp->file.rwait);
2652 ppp_unlock(ppp);
2653 if (atomic_dec_and_test(&ppp->file.refcnt))
2654 ppp_destroy_interface(ppp);
2655 err = 0;
2656 }
2657 return err;
2658 }
2659
2660 /*
2661 * Free up the resources used by a ppp channel.
2662 */
2663 static void ppp_destroy_channel(struct channel *pch)
2664 {
2665 atomic_dec(&channel_count);
2666
2667 if (!pch->file.dead) {
2668 /* "can't happen" */
2669 printk(KERN_ERR "ppp: destroying undead channel %p !\n",
2670 pch);
2671 return;
2672 }
2673 skb_queue_purge(&pch->file.xq);
2674 skb_queue_purge(&pch->file.rq);
2675 kfree(pch);
2676 }
2677
2678 static void __exit ppp_cleanup(void)
2679 {
2680 /* should never happen */
2681 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2682 printk(KERN_ERR "PPP: removing module but units remain!\n");
2683 cardmap_destroy(&all_ppp_units);
2684 if (unregister_chrdev(PPP_MAJOR, "ppp") != 0)
2685 printk(KERN_ERR "PPP: failed to unregister PPP device\n");
2686 devfs_remove("ppp");
2687 class_device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
2688 class_destroy(ppp_class);
2689 }
2690
2691 /*
2692 * Cardmap implementation.
2693 */
2694 static void *cardmap_get(struct cardmap *map, unsigned int nr)
2695 {
2696 struct cardmap *p;
2697 int i;
2698
2699 for (p = map; p != NULL; ) {
2700 if ((i = nr >> p->shift) >= CARDMAP_WIDTH)
2701 return NULL;
2702 if (p->shift == 0)
2703 return p->ptr[i];
2704 nr &= ~(CARDMAP_MASK << p->shift);
2705 p = p->ptr[i];
2706 }
2707 return NULL;
2708 }
2709
2710 static void cardmap_set(struct cardmap **pmap, unsigned int nr, void *ptr)
2711 {
2712 struct cardmap *p;
2713 int i;
2714
2715 p = *pmap;
2716 if (p == NULL || (nr >> p->shift) >= CARDMAP_WIDTH) {
2717 do {
2718 /* need a new top level */
2719 struct cardmap *np = kmalloc(sizeof(*np), GFP_KERNEL);
2720 memset(np, 0, sizeof(*np));
2721 np->ptr[0] = p;
2722 if (p != NULL) {
2723 np->shift = p->shift + CARDMAP_ORDER;
2724 p->parent = np;
2725 } else
2726 np->shift = 0;
2727 p = np;
2728 } while ((nr >> p->shift) >= CARDMAP_WIDTH);
2729 *pmap = p;
2730 }
2731 while (p->shift > 0) {
2732 i = (nr >> p->shift) & CARDMAP_MASK;
2733 if (p->ptr[i] == NULL) {
2734 struct cardmap *np = kmalloc(sizeof(*np), GFP_KERNEL);
2735 memset(np, 0, sizeof(*np));
2736 np->shift = p->shift - CARDMAP_ORDER;
2737 np->parent = p;
2738 p->ptr[i] = np;
2739 }
2740 if (ptr == NULL)
2741 clear_bit(i, &p->inuse);
2742 p = p->ptr[i];
2743 }
2744 i = nr & CARDMAP_MASK;
2745 p->ptr[i] = ptr;
2746 if (ptr != NULL)
2747 set_bit(i, &p->inuse);
2748 else
2749 clear_bit(i, &p->inuse);
2750 }
2751
2752 static unsigned int cardmap_find_first_free(struct cardmap *map)
2753 {
2754 struct cardmap *p;
2755 unsigned int nr = 0;
2756 int i;
2757
2758 if ((p = map) == NULL)
2759 return 0;
2760 for (;;) {
2761 i = find_first_zero_bit(&p->inuse, CARDMAP_WIDTH);
2762 if (i >= CARDMAP_WIDTH) {
2763 if (p->parent == NULL)
2764 return CARDMAP_WIDTH << p->shift;
2765 p = p->parent;
2766 i = (nr >> p->shift) & CARDMAP_MASK;
2767 set_bit(i, &p->inuse);
2768 continue;
2769 }
2770 nr = (nr & (~CARDMAP_MASK << p->shift)) | (i << p->shift);
2771 if (p->shift == 0 || p->ptr[i] == NULL)
2772 return nr;
2773 p = p->ptr[i];
2774 }
2775 }
2776
2777 static void cardmap_destroy(struct cardmap **pmap)
2778 {
2779 struct cardmap *p, *np;
2780 int i;
2781
2782 for (p = *pmap; p != NULL; p = np) {
2783 if (p->shift != 0) {
2784 for (i = 0; i < CARDMAP_WIDTH; ++i)
2785 if (p->ptr[i] != NULL)
2786 break;
2787 if (i < CARDMAP_WIDTH) {
2788 np = p->ptr[i];
2789 p->ptr[i] = NULL;
2790 continue;
2791 }
2792 }
2793 np = p->parent;
2794 kfree(p);
2795 }
2796 *pmap = NULL;
2797 }
2798
2799 /* Module/initialization stuff */
2800
2801 module_init(ppp_init);
2802 module_exit(ppp_cleanup);
2803
2804 EXPORT_SYMBOL(ppp_register_channel);
2805 EXPORT_SYMBOL(ppp_unregister_channel);
2806 EXPORT_SYMBOL(ppp_channel_index);
2807 EXPORT_SYMBOL(ppp_unit_number);
2808 EXPORT_SYMBOL(ppp_input);
2809 EXPORT_SYMBOL(ppp_input_error);
2810 EXPORT_SYMBOL(ppp_output_wakeup);
2811 EXPORT_SYMBOL(ppp_register_compressor);
2812 EXPORT_SYMBOL(ppp_unregister_compressor);
2813 MODULE_LICENSE("GPL");
2814 MODULE_ALIAS_CHARDEV_MAJOR(PPP_MAJOR);
2815 MODULE_ALIAS("/dev/ppp");
Linux kernel - Deliverables
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