?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
[PATCH] UFS: inode->i_sem is not released in error path
[linux-2.6/verdex.git] / drivers / net / ppp_generic.c
blob1c6d328165bb066bd132b44c1fe4d4cbbbc0a096
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) {
528 *p = NULL;
529 return 0;
530 }
531
532 len = uprog.len * sizeof(struct sock_filter);
533 code = kmalloc(len, GFP_KERNEL);
534 if (code == NULL)
535 return -ENOMEM;
536
537 if (copy_from_user(code, uprog.filter, len)) {
538 kfree(code);
539 return -EFAULT;
540 }
541
542 err = sk_chk_filter(code, uprog.len);
543 if (err) {
544 kfree(code);
545 return err;
546 }
547
548 *p = code;
549 return uprog.len;
550 }
551 #endif /* CONFIG_PPP_FILTER */
552
553 static int ppp_ioctl(struct inode *inode, struct file *file,
554 unsigned int cmd, unsigned long arg)
555 {
556 struct ppp_file *pf = file->private_data;
557 struct ppp *ppp;
558 int err = -EFAULT, val, val2, i;
559 struct ppp_idle idle;
560 struct npioctl npi;
561 int unit, cflags;
562 struct slcompress *vj;
563 void __user *argp = (void __user *)arg;
564 int __user *p = argp;
565
566 if (pf == 0)
567 return ppp_unattached_ioctl(pf, file, cmd, arg);
568
569 if (cmd == PPPIOCDETACH) {
570 /*
571 * We have to be careful here... if the file descriptor
572 * has been dup'd, we could have another process in the
573 * middle of a poll using the same file *, so we had
574 * better not free the interface data structures -
575 * instead we fail the ioctl. Even in this case, we
576 * shut down the interface if we are the owner of it.
577 * Actually, we should get rid of PPPIOCDETACH, userland
578 * (i.e. pppd) could achieve the same effect by closing
579 * this fd and reopening /dev/ppp.
580 */
581 err = -EINVAL;
582 if (pf->kind == INTERFACE) {
583 ppp = PF_TO_PPP(pf);
584 if (file == ppp->owner)
585 ppp_shutdown_interface(ppp);
586 }
587 if (atomic_read(&file->f_count) <= 2) {
588 ppp_release(inode, file);
589 err = 0;
590 } else
591 printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%d\n",
592 atomic_read(&file->f_count));
593 return err;
594 }
595
596 if (pf->kind == CHANNEL) {
597 struct channel *pch = PF_TO_CHANNEL(pf);
598 struct ppp_channel *chan;
599
600 switch (cmd) {
601 case PPPIOCCONNECT:
602 if (get_user(unit, p))
603 break;
604 err = ppp_connect_channel(pch, unit);
605 break;
606
607 case PPPIOCDISCONN:
608 err = ppp_disconnect_channel(pch);
609 break;
610
611 default:
612 down_read(&pch->chan_sem);
613 chan = pch->chan;
614 err = -ENOTTY;
615 if (chan && chan->ops->ioctl)
616 err = chan->ops->ioctl(chan, cmd, arg);
617 up_read(&pch->chan_sem);
618 }
619 return err;
620 }
621
622 if (pf->kind != INTERFACE) {
623 /* can't happen */
624 printk(KERN_ERR "PPP: not interface or channel??\n");
625 return -EINVAL;
626 }
627
628 ppp = PF_TO_PPP(pf);
629 switch (cmd) {
630 case PPPIOCSMRU:
631 if (get_user(val, p))
632 break;
633 ppp->mru = val;
634 err = 0;
635 break;
636
637 case PPPIOCSFLAGS:
638 if (get_user(val, p))
639 break;
640 ppp_lock(ppp);
641 cflags = ppp->flags & ~val;
642 ppp->flags = val & SC_FLAG_BITS;
643 ppp_unlock(ppp);
644 if (cflags & SC_CCP_OPEN)
645 ppp_ccp_closed(ppp);
646 err = 0;
647 break;
648
649 case PPPIOCGFLAGS:
650 val = ppp->flags | ppp->xstate | ppp->rstate;
651 if (put_user(val, p))
652 break;
653 err = 0;
654 break;
655
656 case PPPIOCSCOMPRESS:
657 err = ppp_set_compress(ppp, arg);
658 break;
659
660 case PPPIOCGUNIT:
661 if (put_user(ppp->file.index, p))
662 break;
663 err = 0;
664 break;
665
666 case PPPIOCSDEBUG:
667 if (get_user(val, p))
668 break;
669 ppp->debug = val;
670 err = 0;
671 break;
672
673 case PPPIOCGDEBUG:
674 if (put_user(ppp->debug, p))
675 break;
676 err = 0;
677 break;
678
679 case PPPIOCGIDLE:
680 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
681 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
682 if (copy_to_user(argp, &idle, sizeof(idle)))
683 break;
684 err = 0;
685 break;
686
687 case PPPIOCSMAXCID:
688 if (get_user(val, p))
689 break;
690 val2 = 15;
691 if ((val >> 16) != 0) {
692 val2 = val >> 16;
693 val &= 0xffff;
694 }
695 vj = slhc_init(val2+1, val+1);
696 if (vj == 0) {
697 printk(KERN_ERR "PPP: no memory (VJ compressor)\n");
698 err = -ENOMEM;
699 break;
700 }
701 ppp_lock(ppp);
702 if (ppp->vj != 0)
703 slhc_free(ppp->vj);
704 ppp->vj = vj;
705 ppp_unlock(ppp);
706 err = 0;
707 break;
708
709 case PPPIOCGNPMODE:
710 case PPPIOCSNPMODE:
711 if (copy_from_user(&npi, argp, sizeof(npi)))
712 break;
713 err = proto_to_npindex(npi.protocol);
714 if (err < 0)
715 break;
716 i = err;
717 if (cmd == PPPIOCGNPMODE) {
718 err = -EFAULT;
719 npi.mode = ppp->npmode[i];
720 if (copy_to_user(argp, &npi, sizeof(npi)))
721 break;
722 } else {
723 ppp->npmode[i] = npi.mode;
724 /* we may be able to transmit more packets now (??) */
725 netif_wake_queue(ppp->dev);
726 }
727 err = 0;
728 break;
729
730 #ifdef CONFIG_PPP_FILTER
731 case PPPIOCSPASS:
732 {
733 struct sock_filter *code;
734 err = get_filter(argp, &code);
735 if (err >= 0) {
736 ppp_lock(ppp);
737 kfree(ppp->pass_filter);
738 ppp->pass_filter = code;
739 ppp->pass_len = err;
740 ppp_unlock(ppp);
741 err = 0;
742 }
743 break;
744 }
745 case PPPIOCSACTIVE:
746 {
747 struct sock_filter *code;
748 err = get_filter(argp, &code);
749 if (err >= 0) {
750 ppp_lock(ppp);
751 kfree(ppp->active_filter);
752 ppp->active_filter = code;
753 ppp->active_len = err;
754 ppp_unlock(ppp);
755 err = 0;
756 }
757 break;
758 }
759 #endif /* CONFIG_PPP_FILTER */
760
761 #ifdef CONFIG_PPP_MULTILINK
762 case PPPIOCSMRRU:
763 if (get_user(val, p))
764 break;
765 ppp_recv_lock(ppp);
766 ppp->mrru = val;
767 ppp_recv_unlock(ppp);
768 err = 0;
769 break;
770 #endif /* CONFIG_PPP_MULTILINK */
771
772 default:
773 err = -ENOTTY;
774 }
775
776 return err;
777 }
778
779 static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file,
780 unsigned int cmd, unsigned long arg)
781 {
782 int unit, err = -EFAULT;
783 struct ppp *ppp;
784 struct channel *chan;
785 int __user *p = (int __user *)arg;
786
787 switch (cmd) {
788 case PPPIOCNEWUNIT:
789 /* Create a new ppp unit */
790 if (get_user(unit, p))
791 break;
792 ppp = ppp_create_interface(unit, &err);
793 if (ppp == 0)
794 break;
795 file->private_data = &ppp->file;
796 ppp->owner = file;
797 err = -EFAULT;
798 if (put_user(ppp->file.index, p))
799 break;
800 err = 0;
801 break;
802
803 case PPPIOCATTACH:
804 /* Attach to an existing ppp unit */
805 if (get_user(unit, p))
806 break;
807 down(&all_ppp_sem);
808 err = -ENXIO;
809 ppp = ppp_find_unit(unit);
810 if (ppp != 0) {
811 atomic_inc(&ppp->file.refcnt);
812 file->private_data = &ppp->file;
813 err = 0;
814 }
815 up(&all_ppp_sem);
816 break;
817
818 case PPPIOCATTCHAN:
819 if (get_user(unit, p))
820 break;
821 spin_lock_bh(&all_channels_lock);
822 err = -ENXIO;
823 chan = ppp_find_channel(unit);
824 if (chan != 0) {
825 atomic_inc(&chan->file.refcnt);
826 file->private_data = &chan->file;
827 err = 0;
828 }
829 spin_unlock_bh(&all_channels_lock);
830 break;
831
832 default:
833 err = -ENOTTY;
834 }
835 return err;
836 }
837
838 static struct file_operations ppp_device_fops = {
839 .owner = THIS_MODULE,
840 .read = ppp_read,
841 .write = ppp_write,
842 .poll = ppp_poll,
843 .ioctl = ppp_ioctl,
844 .open = ppp_open,
845 .release = ppp_release
846 };
847
848 #define PPP_MAJOR 108
849
850 /* Called at boot time if ppp is compiled into the kernel,
851 or at module load time (from init_module) if compiled as a module. */
852 static int __init ppp_init(void)
853 {
854 int err;
855
856 printk(KERN_INFO "PPP generic driver version " PPP_VERSION "\n");
857 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
858 if (!err) {
859 ppp_class = class_create(THIS_MODULE, "ppp");
860 if (IS_ERR(ppp_class)) {
861 err = PTR_ERR(ppp_class);
862 goto out_chrdev;
863 }
864 class_device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
865 err = devfs_mk_cdev(MKDEV(PPP_MAJOR, 0),
866 S_IFCHR|S_IRUSR|S_IWUSR, "ppp");
867 if (err)
868 goto out_class;
869 }
870
871 out:
872 if (err)
873 printk(KERN_ERR "failed to register PPP device (%d)\n", err);
874 return err;
875
876 out_class:
877 class_device_destroy(ppp_class, MKDEV(PPP_MAJOR,0));
878 class_destroy(ppp_class);
879 out_chrdev:
880 unregister_chrdev(PPP_MAJOR, "ppp");
881 goto out;
882 }
883
884 /*
885 * Network interface unit routines.
886 */
887 static int
888 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
889 {
890 struct ppp *ppp = (struct ppp *) dev->priv;
891 int npi, proto;
892 unsigned char *pp;
893
894 npi = ethertype_to_npindex(ntohs(skb->protocol));
895 if (npi < 0)
896 goto outf;
897
898 /* Drop, accept or reject the packet */
899 switch (ppp->npmode[npi]) {
900 case NPMODE_PASS:
901 break;
902 case NPMODE_QUEUE:
903 /* it would be nice to have a way to tell the network
904 system to queue this one up for later. */
905 goto outf;
906 case NPMODE_DROP:
907 case NPMODE_ERROR:
908 goto outf;
909 }
910
911 /* Put the 2-byte PPP protocol number on the front,
912 making sure there is room for the address and control fields. */
913 if (skb_headroom(skb) < PPP_HDRLEN) {
914 struct sk_buff *ns;
915
916 ns = alloc_skb(skb->len + dev->hard_header_len, GFP_ATOMIC);
917 if (ns == 0)
918 goto outf;
919 skb_reserve(ns, dev->hard_header_len);
920 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
921 kfree_skb(skb);
922 skb = ns;
923 }
924 pp = skb_push(skb, 2);
925 proto = npindex_to_proto[npi];
926 pp[0] = proto >> 8;
927 pp[1] = proto;
928
929 netif_stop_queue(dev);
930 skb_queue_tail(&ppp->file.xq, skb);
931 ppp_xmit_process(ppp);
932 return 0;
933
934 outf:
935 kfree_skb(skb);
936 ++ppp->stats.tx_dropped;
937 return 0;
938 }
939
940 static struct net_device_stats *
941 ppp_net_stats(struct net_device *dev)
942 {
943 struct ppp *ppp = (struct ppp *) dev->priv;
944
945 return &ppp->stats;
946 }
947
948 static int
949 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
950 {
951 struct ppp *ppp = dev->priv;
952 int err = -EFAULT;
953 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
954 struct ppp_stats stats;
955 struct ppp_comp_stats cstats;
956 char *vers;
957
958 switch (cmd) {
959 case SIOCGPPPSTATS:
960 ppp_get_stats(ppp, &stats);
961 if (copy_to_user(addr, &stats, sizeof(stats)))
962 break;
963 err = 0;
964 break;
965
966 case SIOCGPPPCSTATS:
967 memset(&cstats, 0, sizeof(cstats));
968 if (ppp->xc_state != 0)
969 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
970 if (ppp->rc_state != 0)
971 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
972 if (copy_to_user(addr, &cstats, sizeof(cstats)))
973 break;
974 err = 0;
975 break;
976
977 case SIOCGPPPVER:
978 vers = PPP_VERSION;
979 if (copy_to_user(addr, vers, strlen(vers) + 1))
980 break;
981 err = 0;
982 break;
983
984 default:
985 err = -EINVAL;
986 }
987
988 return err;
989 }
990
991 static void ppp_setup(struct net_device *dev)
992 {
993 dev->hard_header_len = PPP_HDRLEN;
994 dev->mtu = PPP_MTU;
995 dev->addr_len = 0;
996 dev->tx_queue_len = 3;
997 dev->type = ARPHRD_PPP;
998 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
999 }
1000
1001 /*
1002 * Transmit-side routines.
1003 */
1004
1005 /*
1006 * Called to do any work queued up on the transmit side
1007 * that can now be done.
1008 */
1009 static void
1010 ppp_xmit_process(struct ppp *ppp)
1011 {
1012 struct sk_buff *skb;
1013
1014 ppp_xmit_lock(ppp);
1015 if (ppp->dev != 0) {
1016 ppp_push(ppp);
1017 while (ppp->xmit_pending == 0
1018 && (skb = skb_dequeue(&ppp->file.xq)) != 0)
1019 ppp_send_frame(ppp, skb);
1020 /* If there's no work left to do, tell the core net
1021 code that we can accept some more. */
1022 if (ppp->xmit_pending == 0 && skb_peek(&ppp->file.xq) == 0)
1023 netif_wake_queue(ppp->dev);
1024 }
1025 ppp_xmit_unlock(ppp);
1026 }
1027
1028 static inline struct sk_buff *
1029 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1030 {
1031 struct sk_buff *new_skb;
1032 int len;
1033 int new_skb_size = ppp->dev->mtu +
1034 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1035 int compressor_skb_size = ppp->dev->mtu +
1036 ppp->xcomp->comp_extra + PPP_HDRLEN;
1037 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1038 if (!new_skb) {
1039 if (net_ratelimit())
1040 printk(KERN_ERR "PPP: no memory (comp pkt)\n");
1041 return NULL;
1042 }
1043 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1044 skb_reserve(new_skb,
1045 ppp->dev->hard_header_len - PPP_HDRLEN);
1046
1047 /* compressor still expects A/C bytes in hdr */
1048 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1049 new_skb->data, skb->len + 2,
1050 compressor_skb_size);
1051 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1052 kfree_skb(skb);
1053 skb = new_skb;
1054 skb_put(skb, len);
1055 skb_pull(skb, 2); /* pull off A/C bytes */
1056 } else if (len == 0) {
1057 /* didn't compress, or CCP not up yet */
1058 kfree_skb(new_skb);
1059 new_skb = skb;
1060 } else {
1061 /*
1062 * (len < 0)
1063 * MPPE requires that we do not send unencrypted
1064 * frames. The compressor will return -1 if we
1065 * should drop the frame. We cannot simply test
1066 * the compress_proto because MPPE and MPPC share
1067 * the same number.
1068 */
1069 if (net_ratelimit())
1070 printk(KERN_ERR "ppp: compressor dropped pkt\n");
1071 kfree_skb(skb);
1072 kfree_skb(new_skb);
1073 new_skb = NULL;
1074 }
1075 return new_skb;
1076 }
1077
1078 /*
1079 * Compress and send a frame.
1080 * The caller should have locked the xmit path,
1081 * and xmit_pending should be 0.
1082 */
1083 static void
1084 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1085 {
1086 int proto = PPP_PROTO(skb);
1087 struct sk_buff *new_skb;
1088 int len;
1089 unsigned char *cp;
1090
1091 if (proto < 0x8000) {
1092 #ifdef CONFIG_PPP_FILTER
1093 /* check if we should pass this packet */
1094 /* the filter instructions are constructed assuming
1095 a four-byte PPP header on each packet */
1096 *skb_push(skb, 2) = 1;
1097 if (ppp->pass_filter
1098 && sk_run_filter(skb, ppp->pass_filter,
1099 ppp->pass_len) == 0) {
1100 if (ppp->debug & 1)
1101 printk(KERN_DEBUG "PPP: outbound frame not passed\n");
1102 kfree_skb(skb);
1103 return;
1104 }
1105 /* if this packet passes the active filter, record the time */
1106 if (!(ppp->active_filter
1107 && sk_run_filter(skb, ppp->active_filter,
1108 ppp->active_len) == 0))
1109 ppp->last_xmit = jiffies;
1110 skb_pull(skb, 2);
1111 #else
1112 /* for data packets, record the time */
1113 ppp->last_xmit = jiffies;
1114 #endif /* CONFIG_PPP_FILTER */
1115 }
1116
1117 ++ppp->stats.tx_packets;
1118 ppp->stats.tx_bytes += skb->len - 2;
1119
1120 switch (proto) {
1121 case PPP_IP:
1122 if (ppp->vj == 0 || (ppp->flags & SC_COMP_TCP) == 0)
1123 break;
1124 /* try to do VJ TCP header compression */
1125 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1126 GFP_ATOMIC);
1127 if (new_skb == 0) {
1128 printk(KERN_ERR "PPP: no memory (VJ comp pkt)\n");
1129 goto drop;
1130 }
1131 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1132 cp = skb->data + 2;
1133 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1134 new_skb->data + 2, &cp,
1135 !(ppp->flags & SC_NO_TCP_CCID));
1136 if (cp == skb->data + 2) {
1137 /* didn't compress */
1138 kfree_skb(new_skb);
1139 } else {
1140 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1141 proto = PPP_VJC_COMP;
1142 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1143 } else {
1144 proto = PPP_VJC_UNCOMP;
1145 cp[0] = skb->data[2];
1146 }
1147 kfree_skb(skb);
1148 skb = new_skb;
1149 cp = skb_put(skb, len + 2);
1150 cp[0] = 0;
1151 cp[1] = proto;
1152 }
1153 break;
1154
1155 case PPP_CCP:
1156 /* peek at outbound CCP frames */
1157 ppp_ccp_peek(ppp, skb, 0);
1158 break;
1159 }
1160
1161 /* try to do packet compression */
1162 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state != 0
1163 && proto != PPP_LCP && proto != PPP_CCP) {
1164 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1165 if (net_ratelimit())
1166 printk(KERN_ERR "ppp: compression required but down - pkt dropped.\n");
1167 goto drop;
1168 }
1169 skb = pad_compress_skb(ppp, skb);
1170 if (!skb)
1171 goto drop;
1172 }
1173
1174 /*
1175 * If we are waiting for traffic (demand dialling),
1176 * queue it up for pppd to receive.
1177 */
1178 if (ppp->flags & SC_LOOP_TRAFFIC) {
1179 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1180 goto drop;
1181 skb_queue_tail(&ppp->file.rq, skb);
1182 wake_up_interruptible(&ppp->file.rwait);
1183 return;
1184 }
1185
1186 ppp->xmit_pending = skb;
1187 ppp_push(ppp);
1188 return;
1189
1190 drop:
1191 if (skb)
1192 kfree_skb(skb);
1193 ++ppp->stats.tx_errors;
1194 }
1195
1196 /*
1197 * Try to send the frame in xmit_pending.
1198 * The caller should have the xmit path locked.
1199 */
1200 static void
1201 ppp_push(struct ppp *ppp)
1202 {
1203 struct list_head *list;
1204 struct channel *pch;
1205 struct sk_buff *skb = ppp->xmit_pending;
1206
1207 if (skb == 0)
1208 return;
1209
1210 list = &ppp->channels;
1211 if (list_empty(list)) {
1212 /* nowhere to send the packet, just drop it */
1213 ppp->xmit_pending = NULL;
1214 kfree_skb(skb);
1215 return;
1216 }
1217
1218 if ((ppp->flags & SC_MULTILINK) == 0) {
1219 /* not doing multilink: send it down the first channel */
1220 list = list->next;
1221 pch = list_entry(list, struct channel, clist);
1222
1223 spin_lock_bh(&pch->downl);
1224 if (pch->chan) {
1225 if (pch->chan->ops->start_xmit(pch->chan, skb))
1226 ppp->xmit_pending = NULL;
1227 } else {
1228 /* channel got unregistered */
1229 kfree_skb(skb);
1230 ppp->xmit_pending = NULL;
1231 }
1232 spin_unlock_bh(&pch->downl);
1233 return;
1234 }
1235
1236 #ifdef CONFIG_PPP_MULTILINK
1237 /* Multilink: fragment the packet over as many links
1238 as can take the packet at the moment. */
1239 if (!ppp_mp_explode(ppp, skb))
1240 return;
1241 #endif /* CONFIG_PPP_MULTILINK */
1242
1243 ppp->xmit_pending = NULL;
1244 kfree_skb(skb);
1245 }
1246
1247 #ifdef CONFIG_PPP_MULTILINK
1248 /*
1249 * Divide a packet to be transmitted into fragments and
1250 * send them out the individual links.
1251 */
1252 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1253 {
1254 int len, fragsize;
1255 int i, bits, hdrlen, mtu;
1256 int flen;
1257 int navail, nfree;
1258 int nbigger;
1259 unsigned char *p, *q;
1260 struct list_head *list;
1261 struct channel *pch;
1262 struct sk_buff *frag;
1263 struct ppp_channel *chan;
1264
1265 nfree = 0; /* # channels which have no packet already queued */
1266 navail = 0; /* total # of usable channels (not deregistered) */
1267 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1268 i = 0;
1269 list_for_each_entry(pch, &ppp->channels, clist) {
1270 navail += pch->avail = (pch->chan != NULL);
1271 if (pch->avail) {
1272 if (skb_queue_empty(&pch->file.xq) ||
1273 !pch->had_frag) {
1274 pch->avail = 2;
1275 ++nfree;
1276 }
1277 if (!pch->had_frag && i < ppp->nxchan)
1278 ppp->nxchan = i;
1279 }
1280 ++i;
1281 }
1282
1283 /*
1284 * Don't start sending this packet unless at least half of
1285 * the channels are free. This gives much better TCP
1286 * performance if we have a lot of channels.
1287 */
1288 if (nfree == 0 || nfree < navail / 2)
1289 return 0; /* can't take now, leave it in xmit_pending */
1290
1291 /* Do protocol field compression (XXX this should be optional) */
1292 p = skb->data;
1293 len = skb->len;
1294 if (*p == 0) {
1295 ++p;
1296 --len;
1297 }
1298
1299 /*
1300 * Decide on fragment size.
1301 * We create a fragment for each free channel regardless of
1302 * how small they are (i.e. even 0 length) in order to minimize
1303 * the time that it will take to detect when a channel drops
1304 * a fragment.
1305 */
1306 fragsize = len;
1307 if (nfree > 1)
1308 fragsize = ROUNDUP(fragsize, nfree);
1309 /* nbigger channels get fragsize bytes, the rest get fragsize-1,
1310 except if nbigger==0, then they all get fragsize. */
1311 nbigger = len % nfree;
1312
1313 /* skip to the channel after the one we last used
1314 and start at that one */
1315 list = &ppp->channels;
1316 for (i = 0; i < ppp->nxchan; ++i) {
1317 list = list->next;
1318 if (list == &ppp->channels) {
1319 i = 0;
1320 break;
1321 }
1322 }
1323
1324 /* create a fragment for each channel */
1325 bits = B;
1326 while (nfree > 0 || len > 0) {
1327 list = list->next;
1328 if (list == &ppp->channels) {
1329 i = 0;
1330 continue;
1331 }
1332 pch = list_entry(list, struct channel, clist);
1333 ++i;
1334 if (!pch->avail)
1335 continue;
1336
1337 /*
1338 * Skip this channel if it has a fragment pending already and
1339 * we haven't given a fragment to all of the free channels.
1340 */
1341 if (pch->avail == 1) {
1342 if (nfree > 0)
1343 continue;
1344 } else {
1345 --nfree;
1346 pch->avail = 1;
1347 }
1348
1349 /* check the channel's mtu and whether it is still attached. */
1350 spin_lock_bh(&pch->downl);
1351 if (pch->chan == NULL) {
1352 /* can't use this channel, it's being deregistered */
1353 spin_unlock_bh(&pch->downl);
1354 pch->avail = 0;
1355 if (--navail == 0)
1356 break;
1357 continue;
1358 }
1359
1360 /*
1361 * Create a fragment for this channel of
1362 * min(max(mtu+2-hdrlen, 4), fragsize, len) bytes.
1363 * If mtu+2-hdrlen < 4, that is a ridiculously small
1364 * MTU, so we use mtu = 2 + hdrlen.
1365 */
1366 if (fragsize > len)
1367 fragsize = len;
1368 flen = fragsize;
1369 mtu = pch->chan->mtu + 2 - hdrlen;
1370 if (mtu < 4)
1371 mtu = 4;
1372 if (flen > mtu)
1373 flen = mtu;
1374 if (flen == len && nfree == 0)
1375 bits |= E;
1376 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1377 if (frag == 0)
1378 goto noskb;
1379 q = skb_put(frag, flen + hdrlen);
1380
1381 /* make the MP header */
1382 q[0] = PPP_MP >> 8;
1383 q[1] = PPP_MP;
1384 if (ppp->flags & SC_MP_XSHORTSEQ) {
1385 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1386 q[3] = ppp->nxseq;
1387 } else {
1388 q[2] = bits;
1389 q[3] = ppp->nxseq >> 16;
1390 q[4] = ppp->nxseq >> 8;
1391 q[5] = ppp->nxseq;
1392 }
1393
1394 /*
1395 * Copy the data in.
1396 * Unfortunately there is a bug in older versions of
1397 * the Linux PPP multilink reconstruction code where it
1398 * drops 0-length fragments. Therefore we make sure the
1399 * fragment has at least one byte of data. Any bytes
1400 * we add in this situation will end up as padding on the
1401 * end of the reconstructed packet.
1402 */
1403 if (flen == 0)
1404 *skb_put(frag, 1) = 0;
1405 else
1406 memcpy(q + hdrlen, p, flen);
1407
1408 /* try to send it down the channel */
1409 chan = pch->chan;
1410 if (!skb_queue_empty(&pch->file.xq) ||
1411 !chan->ops->start_xmit(chan, frag))
1412 skb_queue_tail(&pch->file.xq, frag);
1413 pch->had_frag = 1;
1414 p += flen;
1415 len -= flen;
1416 ++ppp->nxseq;
1417 bits = 0;
1418 spin_unlock_bh(&pch->downl);
1419
1420 if (--nbigger == 0 && fragsize > 0)
1421 --fragsize;
1422 }
1423 ppp->nxchan = i;
1424
1425 return 1;
1426
1427 noskb:
1428 spin_unlock_bh(&pch->downl);
1429 if (ppp->debug & 1)
1430 printk(KERN_ERR "PPP: no memory (fragment)\n");
1431 ++ppp->stats.tx_errors;
1432 ++ppp->nxseq;
1433 return 1; /* abandon the frame */
1434 }
1435 #endif /* CONFIG_PPP_MULTILINK */
1436
1437 /*
1438 * Try to send data out on a channel.
1439 */
1440 static void
1441 ppp_channel_push(struct channel *pch)
1442 {
1443 struct sk_buff *skb;
1444 struct ppp *ppp;
1445
1446 spin_lock_bh(&pch->downl);
1447 if (pch->chan != 0) {
1448 while (!skb_queue_empty(&pch->file.xq)) {
1449 skb = skb_dequeue(&pch->file.xq);
1450 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1451 /* put the packet back and try again later */
1452 skb_queue_head(&pch->file.xq, skb);
1453 break;
1454 }
1455 }
1456 } else {
1457 /* channel got deregistered */
1458 skb_queue_purge(&pch->file.xq);
1459 }
1460 spin_unlock_bh(&pch->downl);
1461 /* see if there is anything from the attached unit to be sent */
1462 if (skb_queue_empty(&pch->file.xq)) {
1463 read_lock_bh(&pch->upl);
1464 ppp = pch->ppp;
1465 if (ppp != 0)
1466 ppp_xmit_process(ppp);
1467 read_unlock_bh(&pch->upl);
1468 }
1469 }
1470
1471 /*
1472 * Receive-side routines.
1473 */
1474
1475 /* misuse a few fields of the skb for MP reconstruction */
1476 #define sequence priority
1477 #define BEbits cb[0]
1478
1479 static inline void
1480 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1481 {
1482 ppp_recv_lock(ppp);
1483 /* ppp->dev == 0 means interface is closing down */
1484 if (ppp->dev != 0)
1485 ppp_receive_frame(ppp, skb, pch);
1486 else
1487 kfree_skb(skb);
1488 ppp_recv_unlock(ppp);
1489 }
1490
1491 void
1492 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1493 {
1494 struct channel *pch = chan->ppp;
1495 int proto;
1496
1497 if (pch == 0 || skb->len == 0) {
1498 kfree_skb(skb);
1499 return;
1500 }
1501
1502 proto = PPP_PROTO(skb);
1503 read_lock_bh(&pch->upl);
1504 if (pch->ppp == 0 || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1505 /* put it on the channel queue */
1506 skb_queue_tail(&pch->file.rq, skb);
1507 /* drop old frames if queue too long */
1508 while (pch->file.rq.qlen > PPP_MAX_RQLEN
1509 && (skb = skb_dequeue(&pch->file.rq)) != 0)
1510 kfree_skb(skb);
1511 wake_up_interruptible(&pch->file.rwait);
1512 } else {
1513 ppp_do_recv(pch->ppp, skb, pch);
1514 }
1515 read_unlock_bh(&pch->upl);
1516 }
1517
1518 /* Put a 0-length skb in the receive queue as an error indication */
1519 void
1520 ppp_input_error(struct ppp_channel *chan, int code)
1521 {
1522 struct channel *pch = chan->ppp;
1523 struct sk_buff *skb;
1524
1525 if (pch == 0)
1526 return;
1527
1528 read_lock_bh(&pch->upl);
1529 if (pch->ppp != 0) {
1530 skb = alloc_skb(0, GFP_ATOMIC);
1531 if (skb != 0) {
1532 skb->len = 0; /* probably unnecessary */
1533 skb->cb[0] = code;
1534 ppp_do_recv(pch->ppp, skb, pch);
1535 }
1536 }
1537 read_unlock_bh(&pch->upl);
1538 }
1539
1540 /*
1541 * We come in here to process a received frame.
1542 * The receive side of the ppp unit is locked.
1543 */
1544 static void
1545 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1546 {
1547 if (skb->len >= 2) {
1548 #ifdef CONFIG_PPP_MULTILINK
1549 /* XXX do channel-level decompression here */
1550 if (PPP_PROTO(skb) == PPP_MP)
1551 ppp_receive_mp_frame(ppp, skb, pch);
1552 else
1553 #endif /* CONFIG_PPP_MULTILINK */
1554 ppp_receive_nonmp_frame(ppp, skb);
1555 return;
1556 }
1557
1558 if (skb->len > 0)
1559 /* note: a 0-length skb is used as an error indication */
1560 ++ppp->stats.rx_length_errors;
1561
1562 kfree_skb(skb);
1563 ppp_receive_error(ppp);
1564 }
1565
1566 static void
1567 ppp_receive_error(struct ppp *ppp)
1568 {
1569 ++ppp->stats.rx_errors;
1570 if (ppp->vj != 0)
1571 slhc_toss(ppp->vj);
1572 }
1573
1574 static void
1575 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1576 {
1577 struct sk_buff *ns;
1578 int proto, len, npi;
1579
1580 /*
1581 * Decompress the frame, if compressed.
1582 * Note that some decompressors need to see uncompressed frames
1583 * that come in as well as compressed frames.
1584 */
1585 if (ppp->rc_state != 0 && (ppp->rstate & SC_DECOMP_RUN)
1586 && (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1587 skb = ppp_decompress_frame(ppp, skb);
1588
1589 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1590 goto err;
1591
1592 proto = PPP_PROTO(skb);
1593 switch (proto) {
1594 case PPP_VJC_COMP:
1595 /* decompress VJ compressed packets */
1596 if (ppp->vj == 0 || (ppp->flags & SC_REJ_COMP_TCP))
1597 goto err;
1598
1599 if (skb_tailroom(skb) < 124) {
1600 /* copy to a new sk_buff with more tailroom */
1601 ns = dev_alloc_skb(skb->len + 128);
1602 if (ns == 0) {
1603 printk(KERN_ERR"PPP: no memory (VJ decomp)\n");
1604 goto err;
1605 }
1606 skb_reserve(ns, 2);
1607 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1608 kfree_skb(skb);
1609 skb = ns;
1610 }
1611 else if (!pskb_may_pull(skb, skb->len))
1612 goto err;
1613
1614 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1615 if (len <= 0) {
1616 printk(KERN_DEBUG "PPP: VJ decompression error\n");
1617 goto err;
1618 }
1619 len += 2;
1620 if (len > skb->len)
1621 skb_put(skb, len - skb->len);
1622 else if (len < skb->len)
1623 skb_trim(skb, len);
1624 proto = PPP_IP;
1625 break;
1626
1627 case PPP_VJC_UNCOMP:
1628 if (ppp->vj == 0 || (ppp->flags & SC_REJ_COMP_TCP))
1629 goto err;
1630
1631 /* Until we fix the decompressor need to make sure
1632 * data portion is linear.
1633 */
1634 if (!pskb_may_pull(skb, skb->len))
1635 goto err;
1636
1637 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1638 printk(KERN_ERR "PPP: VJ uncompressed error\n");
1639 goto err;
1640 }
1641 proto = PPP_IP;
1642 break;
1643
1644 case PPP_CCP:
1645 ppp_ccp_peek(ppp, skb, 1);
1646 break;
1647 }
1648
1649 ++ppp->stats.rx_packets;
1650 ppp->stats.rx_bytes += skb->len - 2;
1651
1652 npi = proto_to_npindex(proto);
1653 if (npi < 0) {
1654 /* control or unknown frame - pass it to pppd */
1655 skb_queue_tail(&ppp->file.rq, skb);
1656 /* limit queue length by dropping old frames */
1657 while (ppp->file.rq.qlen > PPP_MAX_RQLEN
1658 && (skb = skb_dequeue(&ppp->file.rq)) != 0)
1659 kfree_skb(skb);
1660 /* wake up any process polling or blocking on read */
1661 wake_up_interruptible(&ppp->file.rwait);
1662
1663 } else {
1664 /* network protocol frame - give it to the kernel */
1665
1666 #ifdef CONFIG_PPP_FILTER
1667 /* check if the packet passes the pass and active filters */
1668 /* the filter instructions are constructed assuming
1669 a four-byte PPP header on each packet */
1670 *skb_push(skb, 2) = 0;
1671 if (ppp->pass_filter
1672 && sk_run_filter(skb, ppp->pass_filter,
1673 ppp->pass_len) == 0) {
1674 if (ppp->debug & 1)
1675 printk(KERN_DEBUG "PPP: inbound frame not passed\n");
1676 kfree_skb(skb);
1677 return;
1678 }
1679 if (!(ppp->active_filter
1680 && sk_run_filter(skb, ppp->active_filter,
1681 ppp->active_len) == 0))
1682 ppp->last_recv = jiffies;
1683 skb_pull(skb, 2);
1684 #else
1685 ppp->last_recv = jiffies;
1686 #endif /* CONFIG_PPP_FILTER */
1687
1688 if ((ppp->dev->flags & IFF_UP) == 0
1689 || ppp->npmode[npi] != NPMODE_PASS) {
1690 kfree_skb(skb);
1691 } else {
1692 skb_pull(skb, 2); /* chop off protocol */
1693 skb->dev = ppp->dev;
1694 skb->protocol = htons(npindex_to_ethertype[npi]);
1695 skb->mac.raw = skb->data;
1696 netif_rx(skb);
1697 ppp->dev->last_rx = jiffies;
1698 }
1699 }
1700 return;
1701
1702 err:
1703 kfree_skb(skb);
1704 ppp_receive_error(ppp);
1705 }
1706
1707 static struct sk_buff *
1708 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1709 {
1710 int proto = PPP_PROTO(skb);
1711 struct sk_buff *ns;
1712 int len;
1713
1714 /* Until we fix all the decompressor's need to make sure
1715 * data portion is linear.
1716 */
1717 if (!pskb_may_pull(skb, skb->len))
1718 goto err;
1719
1720 if (proto == PPP_COMP) {
1721 ns = dev_alloc_skb(ppp->mru + PPP_HDRLEN);
1722 if (ns == 0) {
1723 printk(KERN_ERR "ppp_decompress_frame: no memory\n");
1724 goto err;
1725 }
1726 /* the decompressor still expects the A/C bytes in the hdr */
1727 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1728 skb->len + 2, ns->data, ppp->mru + PPP_HDRLEN);
1729 if (len < 0) {
1730 /* Pass the compressed frame to pppd as an
1731 error indication. */
1732 if (len == DECOMP_FATALERROR)
1733 ppp->rstate |= SC_DC_FERROR;
1734 kfree_skb(ns);
1735 goto err;
1736 }
1737
1738 kfree_skb(skb);
1739 skb = ns;
1740 skb_put(skb, len);
1741 skb_pull(skb, 2); /* pull off the A/C bytes */
1742
1743 } else {
1744 /* Uncompressed frame - pass to decompressor so it
1745 can update its dictionary if necessary. */
1746 if (ppp->rcomp->incomp)
1747 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1748 skb->len + 2);
1749 }
1750
1751 return skb;
1752
1753 err:
1754 ppp->rstate |= SC_DC_ERROR;
1755 ppp_receive_error(ppp);
1756 return skb;
1757 }
1758
1759 #ifdef CONFIG_PPP_MULTILINK
1760 /*
1761 * Receive a multilink frame.
1762 * We put it on the reconstruction queue and then pull off
1763 * as many completed frames as we can.
1764 */
1765 static void
1766 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1767 {
1768 u32 mask, seq;
1769 struct channel *ch;
1770 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1771
1772 if (!pskb_may_pull(skb, mphdrlen) || ppp->mrru == 0)
1773 goto err; /* no good, throw it away */
1774
1775 /* Decode sequence number and begin/end bits */
1776 if (ppp->flags & SC_MP_SHORTSEQ) {
1777 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1778 mask = 0xfff;
1779 } else {
1780 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1781 mask = 0xffffff;
1782 }
1783 skb->BEbits = skb->data[2];
1784 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
1785
1786 /*
1787 * Do protocol ID decompression on the first fragment of each packet.
1788 */
1789 if ((skb->BEbits & B) && (skb->data[0] & 1))
1790 *skb_push(skb, 1) = 0;
1791
1792 /*
1793 * Expand sequence number to 32 bits, making it as close
1794 * as possible to ppp->minseq.
1795 */
1796 seq |= ppp->minseq & ~mask;
1797 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
1798 seq += mask + 1;
1799 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
1800 seq -= mask + 1; /* should never happen */
1801 skb->sequence = seq;
1802 pch->lastseq = seq;
1803
1804 /*
1805 * If this packet comes before the next one we were expecting,
1806 * drop it.
1807 */
1808 if (seq_before(seq, ppp->nextseq)) {
1809 kfree_skb(skb);
1810 ++ppp->stats.rx_dropped;
1811 ppp_receive_error(ppp);
1812 return;
1813 }
1814
1815 /*
1816 * Reevaluate minseq, the minimum over all channels of the
1817 * last sequence number received on each channel. Because of
1818 * the increasing sequence number rule, we know that any fragment
1819 * before `minseq' which hasn't arrived is never going to arrive.
1820 * The list of channels can't change because we have the receive
1821 * side of the ppp unit locked.
1822 */
1823 list_for_each_entry(ch, &ppp->channels, clist) {
1824 if (seq_before(ch->lastseq, seq))
1825 seq = ch->lastseq;
1826 }
1827 if (seq_before(ppp->minseq, seq))
1828 ppp->minseq = seq;
1829
1830 /* Put the fragment on the reconstruction queue */
1831 ppp_mp_insert(ppp, skb);
1832
1833 /* If the queue is getting long, don't wait any longer for packets
1834 before the start of the queue. */
1835 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN
1836 && seq_before(ppp->minseq, ppp->mrq.next->sequence))
1837 ppp->minseq = ppp->mrq.next->sequence;
1838
1839 /* Pull completed packets off the queue and receive them. */
1840 while ((skb = ppp_mp_reconstruct(ppp)) != 0)
1841 ppp_receive_nonmp_frame(ppp, skb);
1842
1843 return;
1844
1845 err:
1846 kfree_skb(skb);
1847 ppp_receive_error(ppp);
1848 }
1849
1850 /*
1851 * Insert a fragment on the MP reconstruction queue.
1852 * The queue is ordered by increasing sequence number.
1853 */
1854 static void
1855 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
1856 {
1857 struct sk_buff *p;
1858 struct sk_buff_head *list = &ppp->mrq;
1859 u32 seq = skb->sequence;
1860
1861 /* N.B. we don't need to lock the list lock because we have the
1862 ppp unit receive-side lock. */
1863 for (p = list->next; p != (struct sk_buff *)list; p = p->next)
1864 if (seq_before(seq, p->sequence))
1865 break;
1866 __skb_insert(skb, p->prev, p, list);
1867 }
1868
1869 /*
1870 * Reconstruct a packet from the MP fragment queue.
1871 * We go through increasing sequence numbers until we find a
1872 * complete packet, or we get to the sequence number for a fragment
1873 * which hasn't arrived but might still do so.
1874 */
1875 struct sk_buff *
1876 ppp_mp_reconstruct(struct ppp *ppp)
1877 {
1878 u32 seq = ppp->nextseq;
1879 u32 minseq = ppp->minseq;
1880 struct sk_buff_head *list = &ppp->mrq;
1881 struct sk_buff *p, *next;
1882 struct sk_buff *head, *tail;
1883 struct sk_buff *skb = NULL;
1884 int lost = 0, len = 0;
1885
1886 if (ppp->mrru == 0) /* do nothing until mrru is set */
1887 return NULL;
1888 head = list->next;
1889 tail = NULL;
1890 for (p = head; p != (struct sk_buff *) list; p = next) {
1891 next = p->next;
1892 if (seq_before(p->sequence, seq)) {
1893 /* this can't happen, anyway ignore the skb */
1894 printk(KERN_ERR "ppp_mp_reconstruct bad seq %u < %u\n",
1895 p->sequence, seq);
1896 head = next;
1897 continue;
1898 }
1899 if (p->sequence != seq) {
1900 /* Fragment `seq' is missing. If it is after
1901 minseq, it might arrive later, so stop here. */
1902 if (seq_after(seq, minseq))
1903 break;
1904 /* Fragment `seq' is lost, keep going. */
1905 lost = 1;
1906 seq = seq_before(minseq, p->sequence)?
1907 minseq + 1: p->sequence;
1908 next = p;
1909 continue;
1910 }
1911
1912 /*
1913 * At this point we know that all the fragments from
1914 * ppp->nextseq to seq are either present or lost.
1915 * Also, there are no complete packets in the queue
1916 * that have no missing fragments and end before this
1917 * fragment.
1918 */
1919
1920 /* B bit set indicates this fragment starts a packet */
1921 if (p->BEbits & B) {
1922 head = p;
1923 lost = 0;
1924 len = 0;
1925 }
1926
1927 len += p->len;
1928
1929 /* Got a complete packet yet? */
1930 if (lost == 0 && (p->BEbits & E) && (head->BEbits & B)) {
1931 if (len > ppp->mrru + 2) {
1932 ++ppp->stats.rx_length_errors;
1933 printk(KERN_DEBUG "PPP: reconstructed packet"
1934 " is too long (%d)\n", len);
1935 } else if (p == head) {
1936 /* fragment is complete packet - reuse skb */
1937 tail = p;
1938 skb = skb_get(p);
1939 break;
1940 } else if ((skb = dev_alloc_skb(len)) == NULL) {
1941 ++ppp->stats.rx_missed_errors;
1942 printk(KERN_DEBUG "PPP: no memory for "
1943 "reconstructed packet");
1944 } else {
1945 tail = p;
1946 break;
1947 }
1948 ppp->nextseq = seq + 1;
1949 }
1950
1951 /*
1952 * If this is the ending fragment of a packet,
1953 * and we haven't found a complete valid packet yet,
1954 * we can discard up to and including this fragment.
1955 */
1956 if (p->BEbits & E)
1957 head = next;
1958
1959 ++seq;
1960 }
1961
1962 /* If we have a complete packet, copy it all into one skb. */
1963 if (tail != NULL) {
1964 /* If we have discarded any fragments,
1965 signal a receive error. */
1966 if (head->sequence != ppp->nextseq) {
1967 if (ppp->debug & 1)
1968 printk(KERN_DEBUG " missed pkts %u..%u\n",
1969 ppp->nextseq, head->sequence-1);
1970 ++ppp->stats.rx_dropped;
1971 ppp_receive_error(ppp);
1972 }
1973
1974 if (head != tail)
1975 /* copy to a single skb */
1976 for (p = head; p != tail->next; p = p->next)
1977 skb_copy_bits(p, 0, skb_put(skb, p->len), p->len);
1978 ppp->nextseq = tail->sequence + 1;
1979 head = tail->next;
1980 }
1981
1982 /* Discard all the skbuffs that we have copied the data out of
1983 or that we can't use. */
1984 while ((p = list->next) != head) {
1985 __skb_unlink(p, list);
1986 kfree_skb(p);
1987 }
1988
1989 return skb;
1990 }
1991 #endif /* CONFIG_PPP_MULTILINK */
1992
1993 /*
1994 * Channel interface.
1995 */
1996
1997 /*
1998 * Create a new, unattached ppp channel.
1999 */
2000 int
2001 ppp_register_channel(struct ppp_channel *chan)
2002 {
2003 struct channel *pch;
2004
2005 pch = kmalloc(sizeof(struct channel), GFP_KERNEL);
2006 if (pch == 0)
2007 return -ENOMEM;
2008 memset(pch, 0, sizeof(struct channel));
2009 pch->ppp = NULL;
2010 pch->chan = chan;
2011 chan->ppp = pch;
2012 init_ppp_file(&pch->file, CHANNEL);
2013 pch->file.hdrlen = chan->hdrlen;
2014 #ifdef CONFIG_PPP_MULTILINK
2015 pch->lastseq = -1;
2016 #endif /* CONFIG_PPP_MULTILINK */
2017 init_rwsem(&pch->chan_sem);
2018 spin_lock_init(&pch->downl);
2019 rwlock_init(&pch->upl);
2020 spin_lock_bh(&all_channels_lock);
2021 pch->file.index = ++last_channel_index;
2022 list_add(&pch->list, &new_channels);
2023 atomic_inc(&channel_count);
2024 spin_unlock_bh(&all_channels_lock);
2025 return 0;
2026 }
2027
2028 /*
2029 * Return the index of a channel.
2030 */
2031 int ppp_channel_index(struct ppp_channel *chan)
2032 {
2033 struct channel *pch = chan->ppp;
2034
2035 if (pch != 0)
2036 return pch->file.index;
2037 return -1;
2038 }
2039
2040 /*
2041 * Return the PPP unit number to which a channel is connected.
2042 */
2043 int ppp_unit_number(struct ppp_channel *chan)
2044 {
2045 struct channel *pch = chan->ppp;
2046 int unit = -1;
2047
2048 if (pch != 0) {
2049 read_lock_bh(&pch->upl);
2050 if (pch->ppp != 0)
2051 unit = pch->ppp->file.index;
2052 read_unlock_bh(&pch->upl);
2053 }
2054 return unit;
2055 }
2056
2057 /*
2058 * Disconnect a channel from the generic layer.
2059 * This must be called in process context.
2060 */
2061 void
2062 ppp_unregister_channel(struct ppp_channel *chan)
2063 {
2064 struct channel *pch = chan->ppp;
2065
2066 if (pch == 0)
2067 return; /* should never happen */
2068 chan->ppp = NULL;
2069
2070 /*
2071 * This ensures that we have returned from any calls into the
2072 * the channel's start_xmit or ioctl routine before we proceed.
2073 */
2074 down_write(&pch->chan_sem);
2075 spin_lock_bh(&pch->downl);
2076 pch->chan = NULL;
2077 spin_unlock_bh(&pch->downl);
2078 up_write(&pch->chan_sem);
2079 ppp_disconnect_channel(pch);
2080 spin_lock_bh(&all_channels_lock);
2081 list_del(&pch->list);
2082 spin_unlock_bh(&all_channels_lock);
2083 pch->file.dead = 1;
2084 wake_up_interruptible(&pch->file.rwait);
2085 if (atomic_dec_and_test(&pch->file.refcnt))
2086 ppp_destroy_channel(pch);
2087 }
2088
2089 /*
2090 * Callback from a channel when it can accept more to transmit.
2091 * This should be called at BH/softirq level, not interrupt level.
2092 */
2093 void
2094 ppp_output_wakeup(struct ppp_channel *chan)
2095 {
2096 struct channel *pch = chan->ppp;
2097
2098 if (pch == 0)
2099 return;
2100 ppp_channel_push(pch);
2101 }
2102
2103 /*
2104 * Compression control.
2105 */
2106
2107 /* Process the PPPIOCSCOMPRESS ioctl. */
2108 static int
2109 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2110 {
2111 int err;
2112 struct compressor *cp, *ocomp;
2113 struct ppp_option_data data;
2114 void *state, *ostate;
2115 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2116
2117 err = -EFAULT;
2118 if (copy_from_user(&data, (void __user *) arg, sizeof(data))
2119 || (data.length <= CCP_MAX_OPTION_LENGTH
2120 && copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2121 goto out;
2122 err = -EINVAL;
2123 if (data.length > CCP_MAX_OPTION_LENGTH
2124 || ccp_option[1] < 2 || ccp_option[1] > data.length)
2125 goto out;
2126
2127 cp = find_compressor(ccp_option[0]);
2128 #ifdef CONFIG_KMOD
2129 if (cp == 0) {
2130 request_module("ppp-compress-%d", ccp_option[0]);
2131 cp = find_compressor(ccp_option[0]);
2132 }
2133 #endif /* CONFIG_KMOD */
2134 if (cp == 0)
2135 goto out;
2136
2137 err = -ENOBUFS;
2138 if (data.transmit) {
2139 state = cp->comp_alloc(ccp_option, data.length);
2140 if (state != 0) {
2141 ppp_xmit_lock(ppp);
2142 ppp->xstate &= ~SC_COMP_RUN;
2143 ocomp = ppp->xcomp;
2144 ostate = ppp->xc_state;
2145 ppp->xcomp = cp;
2146 ppp->xc_state = state;
2147 ppp_xmit_unlock(ppp);
2148 if (ostate != 0) {
2149 ocomp->comp_free(ostate);
2150 module_put(ocomp->owner);
2151 }
2152 err = 0;
2153 } else
2154 module_put(cp->owner);
2155
2156 } else {
2157 state = cp->decomp_alloc(ccp_option, data.length);
2158 if (state != 0) {
2159 ppp_recv_lock(ppp);
2160 ppp->rstate &= ~SC_DECOMP_RUN;
2161 ocomp = ppp->rcomp;
2162 ostate = ppp->rc_state;
2163 ppp->rcomp = cp;
2164 ppp->rc_state = state;
2165 ppp_recv_unlock(ppp);
2166 if (ostate != 0) {
2167 ocomp->decomp_free(ostate);
2168 module_put(ocomp->owner);
2169 }
2170 err = 0;
2171 } else
2172 module_put(cp->owner);
2173 }
2174
2175 out:
2176 return err;
2177 }
2178
2179 /*
2180 * Look at a CCP packet and update our state accordingly.
2181 * We assume the caller has the xmit or recv path locked.
2182 */
2183 static void
2184 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2185 {
2186 unsigned char *dp;
2187 int len;
2188
2189 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2190 return; /* no header */
2191 dp = skb->data + 2;
2192
2193 switch (CCP_CODE(dp)) {
2194 case CCP_CONFREQ:
2195
2196 /* A ConfReq starts negotiation of compression
2197 * in one direction of transmission,
2198 * and hence brings it down...but which way?
2199 *
2200 * Remember:
2201 * A ConfReq indicates what the sender would like to receive
2202 */
2203 if(inbound)
2204 /* He is proposing what I should send */
2205 ppp->xstate &= ~SC_COMP_RUN;
2206 else
2207 /* I am proposing to what he should send */
2208 ppp->rstate &= ~SC_DECOMP_RUN;
2209
2210 break;
2211
2212 case CCP_TERMREQ:
2213 case CCP_TERMACK:
2214 /*
2215 * CCP is going down, both directions of transmission
2216 */
2217 ppp->rstate &= ~SC_DECOMP_RUN;
2218 ppp->xstate &= ~SC_COMP_RUN;
2219 break;
2220
2221 case CCP_CONFACK:
2222 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2223 break;
2224 len = CCP_LENGTH(dp);
2225 if (!pskb_may_pull(skb, len + 2))
2226 return; /* too short */
2227 dp += CCP_HDRLEN;
2228 len -= CCP_HDRLEN;
2229 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2230 break;
2231 if (inbound) {
2232 /* we will start receiving compressed packets */
2233 if (ppp->rc_state == 0)
2234 break;
2235 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2236 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2237 ppp->rstate |= SC_DECOMP_RUN;
2238 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2239 }
2240 } else {
2241 /* we will soon start sending compressed packets */
2242 if (ppp->xc_state == 0)
2243 break;
2244 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2245 ppp->file.index, 0, ppp->debug))
2246 ppp->xstate |= SC_COMP_RUN;
2247 }
2248 break;
2249
2250 case CCP_RESETACK:
2251 /* reset the [de]compressor */
2252 if ((ppp->flags & SC_CCP_UP) == 0)
2253 break;
2254 if (inbound) {
2255 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2256 ppp->rcomp->decomp_reset(ppp->rc_state);
2257 ppp->rstate &= ~SC_DC_ERROR;
2258 }
2259 } else {
2260 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2261 ppp->xcomp->comp_reset(ppp->xc_state);
2262 }
2263 break;
2264 }
2265 }
2266
2267 /* Free up compression resources. */
2268 static void
2269 ppp_ccp_closed(struct ppp *ppp)
2270 {
2271 void *xstate, *rstate;
2272 struct compressor *xcomp, *rcomp;
2273
2274 ppp_lock(ppp);
2275 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2276 ppp->xstate = 0;
2277 xcomp = ppp->xcomp;
2278 xstate = ppp->xc_state;
2279 ppp->xc_state = NULL;
2280 ppp->rstate = 0;
2281 rcomp = ppp->rcomp;
2282 rstate = ppp->rc_state;
2283 ppp->rc_state = NULL;
2284 ppp_unlock(ppp);
2285
2286 if (xstate) {
2287 xcomp->comp_free(xstate);
2288 module_put(xcomp->owner);
2289 }
2290 if (rstate) {
2291 rcomp->decomp_free(rstate);
2292 module_put(rcomp->owner);
2293 }
2294 }
2295
2296 /* List of compressors. */
2297 static LIST_HEAD(compressor_list);
2298 static DEFINE_SPINLOCK(compressor_list_lock);
2299
2300 struct compressor_entry {
2301 struct list_head list;
2302 struct compressor *comp;
2303 };
2304
2305 static struct compressor_entry *
2306 find_comp_entry(int proto)
2307 {
2308 struct compressor_entry *ce;
2309
2310 list_for_each_entry(ce, &compressor_list, list) {
2311 if (ce->comp->compress_proto == proto)
2312 return ce;
2313 }
2314 return NULL;
2315 }
2316
2317 /* Register a compressor */
2318 int
2319 ppp_register_compressor(struct compressor *cp)
2320 {
2321 struct compressor_entry *ce;
2322 int ret;
2323 spin_lock(&compressor_list_lock);
2324 ret = -EEXIST;
2325 if (find_comp_entry(cp->compress_proto) != 0)
2326 goto out;
2327 ret = -ENOMEM;
2328 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2329 if (ce == 0)
2330 goto out;
2331 ret = 0;
2332 ce->comp = cp;
2333 list_add(&ce->list, &compressor_list);
2334 out:
2335 spin_unlock(&compressor_list_lock);
2336 return ret;
2337 }
2338
2339 /* Unregister a compressor */
2340 void
2341 ppp_unregister_compressor(struct compressor *cp)
2342 {
2343 struct compressor_entry *ce;
2344
2345 spin_lock(&compressor_list_lock);
2346 ce = find_comp_entry(cp->compress_proto);
2347 if (ce != 0 && ce->comp == cp) {
2348 list_del(&ce->list);
2349 kfree(ce);
2350 }
2351 spin_unlock(&compressor_list_lock);
2352 }
2353
2354 /* Find a compressor. */
2355 static struct compressor *
2356 find_compressor(int type)
2357 {
2358 struct compressor_entry *ce;
2359 struct compressor *cp = NULL;
2360
2361 spin_lock(&compressor_list_lock);
2362 ce = find_comp_entry(type);
2363 if (ce != 0) {
2364 cp = ce->comp;
2365 if (!try_module_get(cp->owner))
2366 cp = NULL;
2367 }
2368 spin_unlock(&compressor_list_lock);
2369 return cp;
2370 }
2371
2372 /*
2373 * Miscelleneous stuff.
2374 */
2375
2376 static void
2377 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2378 {
2379 struct slcompress *vj = ppp->vj;
2380
2381 memset(st, 0, sizeof(*st));
2382 st->p.ppp_ipackets = ppp->stats.rx_packets;
2383 st->p.ppp_ierrors = ppp->stats.rx_errors;
2384 st->p.ppp_ibytes = ppp->stats.rx_bytes;
2385 st->p.ppp_opackets = ppp->stats.tx_packets;
2386 st->p.ppp_oerrors = ppp->stats.tx_errors;
2387 st->p.ppp_obytes = ppp->stats.tx_bytes;
2388 if (vj == 0)
2389 return;
2390 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2391 st->vj.vjs_compressed = vj->sls_o_compressed;
2392 st->vj.vjs_searches = vj->sls_o_searches;
2393 st->vj.vjs_misses = vj->sls_o_misses;
2394 st->vj.vjs_errorin = vj->sls_i_error;
2395 st->vj.vjs_tossed = vj->sls_i_tossed;
2396 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2397 st->vj.vjs_compressedin = vj->sls_i_compressed;
2398 }
2399
2400 /*
2401 * Stuff for handling the lists of ppp units and channels
2402 * and for initialization.
2403 */
2404
2405 /*
2406 * Create a new ppp interface unit. Fails if it can't allocate memory
2407 * or if there is already a unit with the requested number.
2408 * unit == -1 means allocate a new number.
2409 */
2410 static struct ppp *
2411 ppp_create_interface(int unit, int *retp)
2412 {
2413 struct ppp *ppp;
2414 struct net_device *dev = NULL;
2415 int ret = -ENOMEM;
2416 int i;
2417
2418 ppp = kmalloc(sizeof(struct ppp), GFP_KERNEL);
2419 if (!ppp)
2420 goto out;
2421 dev = alloc_netdev(0, "", ppp_setup);
2422 if (!dev)
2423 goto out1;
2424 memset(ppp, 0, sizeof(struct ppp));
2425
2426 ppp->mru = PPP_MRU;
2427 init_ppp_file(&ppp->file, INTERFACE);
2428 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2429 for (i = 0; i < NUM_NP; ++i)
2430 ppp->npmode[i] = NPMODE_PASS;
2431 INIT_LIST_HEAD(&ppp->channels);
2432 spin_lock_init(&ppp->rlock);
2433 spin_lock_init(&ppp->wlock);
2434 #ifdef CONFIG_PPP_MULTILINK
2435 ppp->minseq = -1;
2436 skb_queue_head_init(&ppp->mrq);
2437 #endif /* CONFIG_PPP_MULTILINK */
2438 ppp->dev = dev;
2439 dev->priv = ppp;
2440
2441 dev->hard_start_xmit = ppp_start_xmit;
2442 dev->get_stats = ppp_net_stats;
2443 dev->do_ioctl = ppp_net_ioctl;
2444
2445 ret = -EEXIST;
2446 down(&all_ppp_sem);
2447 if (unit < 0)
2448 unit = cardmap_find_first_free(all_ppp_units);
2449 else if (cardmap_get(all_ppp_units, unit) != NULL)
2450 goto out2; /* unit already exists */
2451
2452 /* Initialize the new ppp unit */
2453 ppp->file.index = unit;
2454 sprintf(dev->name, "ppp%d", unit);
2455
2456 ret = register_netdev(dev);
2457 if (ret != 0) {
2458 printk(KERN_ERR "PPP: couldn't register device %s (%d)\n",
2459 dev->name, ret);
2460 goto out2;
2461 }
2462
2463 atomic_inc(&ppp_unit_count);
2464 cardmap_set(&all_ppp_units, unit, ppp);
2465 up(&all_ppp_sem);
2466 *retp = 0;
2467 return ppp;
2468
2469 out2:
2470 up(&all_ppp_sem);
2471 free_netdev(dev);
2472 out1:
2473 kfree(ppp);
2474 out:
2475 *retp = ret;
2476 return NULL;
2477 }
2478
2479 /*
2480 * Initialize a ppp_file structure.
2481 */
2482 static void
2483 init_ppp_file(struct ppp_file *pf, int kind)
2484 {
2485 pf->kind = kind;
2486 skb_queue_head_init(&pf->xq);
2487 skb_queue_head_init(&pf->rq);
2488 atomic_set(&pf->refcnt, 1);
2489 init_waitqueue_head(&pf->rwait);
2490 }
2491
2492 /*
2493 * Take down a ppp interface unit - called when the owning file
2494 * (the one that created the unit) is closed or detached.
2495 */
2496 static void ppp_shutdown_interface(struct ppp *ppp)
2497 {
2498 struct net_device *dev;
2499
2500 down(&all_ppp_sem);
2501 ppp_lock(ppp);
2502 dev = ppp->dev;
2503 ppp->dev = NULL;
2504 ppp_unlock(ppp);
2505 /* This will call dev_close() for us. */
2506 if (dev) {
2507 unregister_netdev(dev);
2508 free_netdev(dev);
2509 }
2510 cardmap_set(&all_ppp_units, ppp->file.index, NULL);
2511 ppp->file.dead = 1;
2512 ppp->owner = NULL;
2513 wake_up_interruptible(&ppp->file.rwait);
2514 up(&all_ppp_sem);
2515 }
2516
2517 /*
2518 * Free the memory used by a ppp unit. This is only called once
2519 * there are no channels connected to the unit and no file structs
2520 * that reference the unit.
2521 */
2522 static void ppp_destroy_interface(struct ppp *ppp)
2523 {
2524 atomic_dec(&ppp_unit_count);
2525
2526 if (!ppp->file.dead || ppp->n_channels) {
2527 /* "can't happen" */
2528 printk(KERN_ERR "ppp: destroying ppp struct %p but dead=%d "
2529 "n_channels=%d !\n", ppp, ppp->file.dead,
2530 ppp->n_channels);
2531 return;
2532 }
2533
2534 ppp_ccp_closed(ppp);
2535 if (ppp->vj) {
2536 slhc_free(ppp->vj);
2537 ppp->vj = NULL;
2538 }
2539 skb_queue_purge(&ppp->file.xq);
2540 skb_queue_purge(&ppp->file.rq);
2541 #ifdef CONFIG_PPP_MULTILINK
2542 skb_queue_purge(&ppp->mrq);
2543 #endif /* CONFIG_PPP_MULTILINK */
2544 #ifdef CONFIG_PPP_FILTER
2545 kfree(ppp->pass_filter);
2546 ppp->pass_filter = NULL;
2547 kfree(ppp->active_filter);
2548 ppp->active_filter = NULL;
2549 #endif /* CONFIG_PPP_FILTER */
2550
2551 kfree(ppp);
2552 }
2553
2554 /*
2555 * Locate an existing ppp unit.
2556 * The caller should have locked the all_ppp_sem.
2557 */
2558 static struct ppp *
2559 ppp_find_unit(int unit)
2560 {
2561 return cardmap_get(all_ppp_units, unit);
2562 }
2563
2564 /*
2565 * Locate an existing ppp channel.
2566 * The caller should have locked the all_channels_lock.
2567 * First we look in the new_channels list, then in the
2568 * all_channels list. If found in the new_channels list,
2569 * we move it to the all_channels list. This is for speed
2570 * when we have a lot of channels in use.
2571 */
2572 static struct channel *
2573 ppp_find_channel(int unit)
2574 {
2575 struct channel *pch;
2576
2577 list_for_each_entry(pch, &new_channels, list) {
2578 if (pch->file.index == unit) {
2579 list_del(&pch->list);
2580 list_add(&pch->list, &all_channels);
2581 return pch;
2582 }
2583 }
2584 list_for_each_entry(pch, &all_channels, list) {
2585 if (pch->file.index == unit)
2586 return pch;
2587 }
2588 return NULL;
2589 }
2590
2591 /*
2592 * Connect a PPP channel to a PPP interface unit.
2593 */
2594 static int
2595 ppp_connect_channel(struct channel *pch, int unit)
2596 {
2597 struct ppp *ppp;
2598 int ret = -ENXIO;
2599 int hdrlen;
2600
2601 down(&all_ppp_sem);
2602 ppp = ppp_find_unit(unit);
2603 if (ppp == 0)
2604 goto out;
2605 write_lock_bh(&pch->upl);
2606 ret = -EINVAL;
2607 if (pch->ppp != 0)
2608 goto outl;
2609
2610 ppp_lock(ppp);
2611 if (pch->file.hdrlen > ppp->file.hdrlen)
2612 ppp->file.hdrlen = pch->file.hdrlen;
2613 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2614 if (ppp->dev && hdrlen > ppp->dev->hard_header_len)
2615 ppp->dev->hard_header_len = hdrlen;
2616 list_add_tail(&pch->clist, &ppp->channels);
2617 ++ppp->n_channels;
2618 pch->ppp = ppp;
2619 atomic_inc(&ppp->file.refcnt);
2620 ppp_unlock(ppp);
2621 ret = 0;
2622
2623 outl:
2624 write_unlock_bh(&pch->upl);
2625 out:
2626 up(&all_ppp_sem);
2627 return ret;
2628 }
2629
2630 /*
2631 * Disconnect a channel from its ppp unit.
2632 */
2633 static int
2634 ppp_disconnect_channel(struct channel *pch)
2635 {
2636 struct ppp *ppp;
2637 int err = -EINVAL;
2638
2639 write_lock_bh(&pch->upl);
2640 ppp = pch->ppp;
2641 pch->ppp = NULL;
2642 write_unlock_bh(&pch->upl);
2643 if (ppp != 0) {
2644 /* remove it from the ppp unit's list */
2645 ppp_lock(ppp);
2646 list_del(&pch->clist);
2647 if (--ppp->n_channels == 0)
2648 wake_up_interruptible(&ppp->file.rwait);
2649 ppp_unlock(ppp);
2650 if (atomic_dec_and_test(&ppp->file.refcnt))
2651 ppp_destroy_interface(ppp);
2652 err = 0;
2653 }
2654 return err;
2655 }
2656
2657 /*
2658 * Free up the resources used by a ppp channel.
2659 */
2660 static void ppp_destroy_channel(struct channel *pch)
2661 {
2662 atomic_dec(&channel_count);
2663
2664 if (!pch->file.dead) {
2665 /* "can't happen" */
2666 printk(KERN_ERR "ppp: destroying undead channel %p !\n",
2667 pch);
2668 return;
2669 }
2670 skb_queue_purge(&pch->file.xq);
2671 skb_queue_purge(&pch->file.rq);
2672 kfree(pch);
2673 }
2674
2675 static void __exit ppp_cleanup(void)
2676 {
2677 /* should never happen */
2678 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2679 printk(KERN_ERR "PPP: removing module but units remain!\n");
2680 cardmap_destroy(&all_ppp_units);
2681 if (unregister_chrdev(PPP_MAJOR, "ppp") != 0)
2682 printk(KERN_ERR "PPP: failed to unregister PPP device\n");
2683 devfs_remove("ppp");
2684 class_device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
2685 class_destroy(ppp_class);
2686 }
2687
2688 /*
2689 * Cardmap implementation.
2690 */
2691 static void *cardmap_get(struct cardmap *map, unsigned int nr)
2692 {
2693 struct cardmap *p;
2694 int i;
2695
2696 for (p = map; p != NULL; ) {
2697 if ((i = nr >> p->shift) >= CARDMAP_WIDTH)
2698 return NULL;
2699 if (p->shift == 0)
2700 return p->ptr[i];
2701 nr &= ~(CARDMAP_MASK << p->shift);
2702 p = p->ptr[i];
2703 }
2704 return NULL;
2705 }
2706
2707 static void cardmap_set(struct cardmap **pmap, unsigned int nr, void *ptr)
2708 {
2709 struct cardmap *p;
2710 int i;
2711
2712 p = *pmap;
2713 if (p == NULL || (nr >> p->shift) >= CARDMAP_WIDTH) {
2714 do {
2715 /* need a new top level */
2716 struct cardmap *np = kmalloc(sizeof(*np), GFP_KERNEL);
2717 memset(np, 0, sizeof(*np));
2718 np->ptr[0] = p;
2719 if (p != NULL) {
2720 np->shift = p->shift + CARDMAP_ORDER;
2721 p->parent = np;
2722 } else
2723 np->shift = 0;
2724 p = np;
2725 } while ((nr >> p->shift) >= CARDMAP_WIDTH);
2726 *pmap = p;
2727 }
2728 while (p->shift > 0) {
2729 i = (nr >> p->shift) & CARDMAP_MASK;
2730 if (p->ptr[i] == NULL) {
2731 struct cardmap *np = kmalloc(sizeof(*np), GFP_KERNEL);
2732 memset(np, 0, sizeof(*np));
2733 np->shift = p->shift - CARDMAP_ORDER;
2734 np->parent = p;
2735 p->ptr[i] = np;
2736 }
2737 if (ptr == NULL)
2738 clear_bit(i, &p->inuse);
2739 p = p->ptr[i];
2740 }
2741 i = nr & CARDMAP_MASK;
2742 p->ptr[i] = ptr;
2743 if (ptr != NULL)
2744 set_bit(i, &p->inuse);
2745 else
2746 clear_bit(i, &p->inuse);
2747 }
2748
2749 static unsigned int cardmap_find_first_free(struct cardmap *map)
2750 {
2751 struct cardmap *p;
2752 unsigned int nr = 0;
2753 int i;
2754
2755 if ((p = map) == NULL)
2756 return 0;
2757 for (;;) {
2758 i = find_first_zero_bit(&p->inuse, CARDMAP_WIDTH);
2759 if (i >= CARDMAP_WIDTH) {
2760 if (p->parent == NULL)
2761 return CARDMAP_WIDTH << p->shift;
2762 p = p->parent;
2763 i = (nr >> p->shift) & CARDMAP_MASK;
2764 set_bit(i, &p->inuse);
2765 continue;
2766 }
2767 nr = (nr & (~CARDMAP_MASK << p->shift)) | (i << p->shift);
2768 if (p->shift == 0 || p->ptr[i] == NULL)
2769 return nr;
2770 p = p->ptr[i];
2771 }
2772 }
2773
2774 static void cardmap_destroy(struct cardmap **pmap)
2775 {
2776 struct cardmap *p, *np;
2777 int i;
2778
2779 for (p = *pmap; p != NULL; p = np) {
2780 if (p->shift != 0) {
2781 for (i = 0; i < CARDMAP_WIDTH; ++i)
2782 if (p->ptr[i] != NULL)
2783 break;
2784 if (i < CARDMAP_WIDTH) {
2785 np = p->ptr[i];
2786 p->ptr[i] = NULL;
2787 continue;
2788 }
2789 }
2790 np = p->parent;
2791 kfree(p);
2792 }
2793 *pmap = NULL;
2794 }
2795
2796 /* Module/initialization stuff */
2797
2798 module_init(ppp_init);
2799 module_exit(ppp_cleanup);
2800
2801 EXPORT_SYMBOL(ppp_register_channel);
2802 EXPORT_SYMBOL(ppp_unregister_channel);
2803 EXPORT_SYMBOL(ppp_channel_index);
2804 EXPORT_SYMBOL(ppp_unit_number);
2805 EXPORT_SYMBOL(ppp_input);
2806 EXPORT_SYMBOL(ppp_input_error);
2807 EXPORT_SYMBOL(ppp_output_wakeup);
2808 EXPORT_SYMBOL(ppp_register_compressor);
2809 EXPORT_SYMBOL(ppp_unregister_compressor);
2810 MODULE_LICENSE("GPL");
2811 MODULE_ALIAS_CHARDEV_MAJOR(PPP_MAJOR);
2812 MODULE_ALIAS("/dev/ppp");
Verdex Pro support