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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris...
[linux-2.6/mini2440.git] / drivers / net / ppp_generic.c
blobcd37d739ac74b08a833907874cbeef4922c73080
1 /*
2 * Generic PPP layer for Linux.
3 *
4 * Copyright 1999-2002 Paul Mackerras.
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 *
11 * The generic PPP layer handles the PPP network interfaces, the
12 * /dev/ppp device, packet and VJ compression, and multilink.
13 * It talks to PPP `channels' via the interface defined in
14 * include/linux/ppp_channel.h. Channels provide the basic means for
15 * sending and receiving PPP frames on some kind of communications
16 * channel.
17 *
18 * Part of the code in this driver was inspired by the old async-only
19 * PPP driver, written by Michael Callahan and Al Longyear, and
20 * subsequently hacked by Paul Mackerras.
21 *
22 * ==FILEVERSION 20041108==
23 */
24
25 #include <linux/module.h>
26 #include <linux/kernel.h>
27 #include <linux/kmod.h>
28 #include <linux/init.h>
29 #include <linux/list.h>
30 #include <linux/idr.h>
31 #include <linux/netdevice.h>
32 #include <linux/poll.h>
33 #include <linux/ppp_defs.h>
34 #include <linux/filter.h>
35 #include <linux/if_ppp.h>
36 #include <linux/ppp_channel.h>
37 #include <linux/ppp-comp.h>
38 #include <linux/skbuff.h>
39 #include <linux/rtnetlink.h>
40 #include <linux/if_arp.h>
41 #include <linux/ip.h>
42 #include <linux/tcp.h>
43 #include <linux/smp_lock.h>
44 #include <linux/spinlock.h>
45 #include <linux/rwsem.h>
46 #include <linux/stddef.h>
47 #include <linux/device.h>
48 #include <linux/mutex.h>
49 #include <net/slhc_vj.h>
50 #include <asm/atomic.h>
51
52 #include <linux/nsproxy.h>
53 #include <net/net_namespace.h>
54 #include <net/netns/generic.h>
55
56 #define PPP_VERSION "2.4.2"
57
58 /*
59 * Network protocols we support.
60 */
61 #define NP_IP 0 /* Internet Protocol V4 */
62 #define NP_IPV6 1 /* Internet Protocol V6 */
63 #define NP_IPX 2 /* IPX protocol */
64 #define NP_AT 3 /* Appletalk protocol */
65 #define NP_MPLS_UC 4 /* MPLS unicast */
66 #define NP_MPLS_MC 5 /* MPLS multicast */
67 #define NUM_NP 6 /* Number of NPs. */
68
69 #define MPHDRLEN 6 /* multilink protocol header length */
70 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */
71 #define MIN_FRAG_SIZE 64
72
73 /*
74 * An instance of /dev/ppp can be associated with either a ppp
75 * interface unit or a ppp channel. In both cases, file->private_data
76 * points to one of these.
77 */
78 struct ppp_file {
79 enum {
80 INTERFACE=1, CHANNEL
81 } kind;
82 struct sk_buff_head xq; /* pppd transmit queue */
83 struct sk_buff_head rq; /* receive queue for pppd */
84 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */
85 atomic_t refcnt; /* # refs (incl /dev/ppp attached) */
86 int hdrlen; /* space to leave for headers */
87 int index; /* interface unit / channel number */
88 int dead; /* unit/channel has been shut down */
89 };
90
91 #define PF_TO_X(pf, X) container_of(pf, X, file)
92
93 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
94 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
95
96 /*
97 * Data structure describing one ppp unit.
98 * A ppp unit corresponds to a ppp network interface device
99 * and represents a multilink bundle.
100 * It can have 0 or more ppp channels connected to it.
101 */
102 struct ppp {
103 struct ppp_file file; /* stuff for read/write/poll 0 */
104 struct file *owner; /* file that owns this unit 48 */
105 struct list_head channels; /* list of attached channels 4c */
106 int n_channels; /* how many channels are attached 54 */
107 spinlock_t rlock; /* lock for receive side 58 */
108 spinlock_t wlock; /* lock for transmit side 5c */
109 int mru; /* max receive unit 60 */
110 unsigned int flags; /* control bits 64 */
111 unsigned int xstate; /* transmit state bits 68 */
112 unsigned int rstate; /* receive state bits 6c */
113 int debug; /* debug flags 70 */
114 struct slcompress *vj; /* state for VJ header compression */
115 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
116 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
117 struct compressor *xcomp; /* transmit packet compressor 8c */
118 void *xc_state; /* its internal state 90 */
119 struct compressor *rcomp; /* receive decompressor 94 */
120 void *rc_state; /* its internal state 98 */
121 unsigned long last_xmit; /* jiffies when last pkt sent 9c */
122 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
123 struct net_device *dev; /* network interface device a4 */
124 int closing; /* is device closing down? a8 */
125 #ifdef CONFIG_PPP_MULTILINK
126 int nxchan; /* next channel to send something on */
127 u32 nxseq; /* next sequence number to send */
128 int mrru; /* MP: max reconst. receive unit */
129 u32 nextseq; /* MP: seq no of next packet */
130 u32 minseq; /* MP: min of most recent seqnos */
131 struct sk_buff_head mrq; /* MP: receive reconstruction queue */
132 #endif /* CONFIG_PPP_MULTILINK */
133 #ifdef CONFIG_PPP_FILTER
134 struct sock_filter *pass_filter; /* filter for packets to pass */
135 struct sock_filter *active_filter;/* filter for pkts to reset idle */
136 unsigned pass_len, active_len;
137 #endif /* CONFIG_PPP_FILTER */
138 struct net *ppp_net; /* the net we belong to */
139 };
140
141 /*
142 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
143 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
144 * SC_MUST_COMP
145 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
146 * Bits in xstate: SC_COMP_RUN
147 */
148 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
149 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
150 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
151
152 /*
153 * Private data structure for each channel.
154 * This includes the data structure used for multilink.
155 */
156 struct channel {
157 struct ppp_file file; /* stuff for read/write/poll */
158 struct list_head list; /* link in all/new_channels list */
159 struct ppp_channel *chan; /* public channel data structure */
160 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
161 spinlock_t downl; /* protects `chan', file.xq dequeue */
162 struct ppp *ppp; /* ppp unit we're connected to */
163 struct net *chan_net; /* the net channel belongs to */
164 struct list_head clist; /* link in list of channels per unit */
165 rwlock_t upl; /* protects `ppp' */
166 #ifdef CONFIG_PPP_MULTILINK
167 u8 avail; /* flag used in multilink stuff */
168 u8 had_frag; /* >= 1 fragments have been sent */
169 u32 lastseq; /* MP: last sequence # received */
170 int speed; /* speed of the corresponding ppp channel*/
171 #endif /* CONFIG_PPP_MULTILINK */
172 };
173
174 /*
175 * SMP locking issues:
176 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
177 * list and the ppp.n_channels field, you need to take both locks
178 * before you modify them.
179 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
180 * channel.downl.
181 */
182
183 static atomic_t ppp_unit_count = ATOMIC_INIT(0);
184 static atomic_t channel_count = ATOMIC_INIT(0);
185
186 /* per-net private data for this module */
187 static int ppp_net_id;
188 struct ppp_net {
189 /* units to ppp mapping */
190 struct idr units_idr;
191
192 /*
193 * all_ppp_mutex protects the units_idr mapping.
194 * It also ensures that finding a ppp unit in the units_idr
195 * map and updating its file.refcnt field is atomic.
196 */
197 struct mutex all_ppp_mutex;
198
199 /* channels */
200 struct list_head all_channels;
201 struct list_head new_channels;
202 int last_channel_index;
203
204 /*
205 * all_channels_lock protects all_channels and
206 * last_channel_index, and the atomicity of find
207 * a channel and updating its file.refcnt field.
208 */
209 spinlock_t all_channels_lock;
210 };
211
212 /* Get the PPP protocol number from a skb */
213 #define PPP_PROTO(skb) (((skb)->data[0] << 8) + (skb)->data[1])
214
215 /* We limit the length of ppp->file.rq to this (arbitrary) value */
216 #define PPP_MAX_RQLEN 32
217
218 /*
219 * Maximum number of multilink fragments queued up.
220 * This has to be large enough to cope with the maximum latency of
221 * the slowest channel relative to the others. Strictly it should
222 * depend on the number of channels and their characteristics.
223 */
224 #define PPP_MP_MAX_QLEN 128
225
226 /* Multilink header bits. */
227 #define B 0x80 /* this fragment begins a packet */
228 #define E 0x40 /* this fragment ends a packet */
229
230 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */
231 #define seq_before(a, b) ((s32)((a) - (b)) < 0)
232 #define seq_after(a, b) ((s32)((a) - (b)) > 0)
233
234 /* Prototypes. */
235 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
236 struct file *file, unsigned int cmd, unsigned long arg);
237 static void ppp_xmit_process(struct ppp *ppp);
238 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
239 static void ppp_push(struct ppp *ppp);
240 static void ppp_channel_push(struct channel *pch);
241 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
242 struct channel *pch);
243 static void ppp_receive_error(struct ppp *ppp);
244 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
245 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
246 struct sk_buff *skb);
247 #ifdef CONFIG_PPP_MULTILINK
248 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
249 struct channel *pch);
250 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
251 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
252 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
253 #endif /* CONFIG_PPP_MULTILINK */
254 static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
255 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
256 static void ppp_ccp_closed(struct ppp *ppp);
257 static struct compressor *find_compressor(int type);
258 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
259 static struct ppp *ppp_create_interface(struct net *net, int unit, int *retp);
260 static void init_ppp_file(struct ppp_file *pf, int kind);
261 static void ppp_shutdown_interface(struct ppp *ppp);
262 static void ppp_destroy_interface(struct ppp *ppp);
263 static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit);
264 static struct channel *ppp_find_channel(struct ppp_net *pn, int unit);
265 static int ppp_connect_channel(struct channel *pch, int unit);
266 static int ppp_disconnect_channel(struct channel *pch);
267 static void ppp_destroy_channel(struct channel *pch);
268 static int unit_get(struct idr *p, void *ptr);
269 static int unit_set(struct idr *p, void *ptr, int n);
270 static void unit_put(struct idr *p, int n);
271 static void *unit_find(struct idr *p, int n);
272
273 static struct class *ppp_class;
274
275 /* per net-namespace data */
276 static inline struct ppp_net *ppp_pernet(struct net *net)
277 {
278 BUG_ON(!net);
279
280 return net_generic(net, ppp_net_id);
281 }
282
283 /* Translates a PPP protocol number to a NP index (NP == network protocol) */
284 static inline int proto_to_npindex(int proto)
285 {
286 switch (proto) {
287 case PPP_IP:
288 return NP_IP;
289 case PPP_IPV6:
290 return NP_IPV6;
291 case PPP_IPX:
292 return NP_IPX;
293 case PPP_AT:
294 return NP_AT;
295 case PPP_MPLS_UC:
296 return NP_MPLS_UC;
297 case PPP_MPLS_MC:
298 return NP_MPLS_MC;
299 }
300 return -EINVAL;
301 }
302
303 /* Translates an NP index into a PPP protocol number */
304 static const int npindex_to_proto[NUM_NP] = {
305 PPP_IP,
306 PPP_IPV6,
307 PPP_IPX,
308 PPP_AT,
309 PPP_MPLS_UC,
310 PPP_MPLS_MC,
311 };
312
313 /* Translates an ethertype into an NP index */
314 static inline int ethertype_to_npindex(int ethertype)
315 {
316 switch (ethertype) {
317 case ETH_P_IP:
318 return NP_IP;
319 case ETH_P_IPV6:
320 return NP_IPV6;
321 case ETH_P_IPX:
322 return NP_IPX;
323 case ETH_P_PPPTALK:
324 case ETH_P_ATALK:
325 return NP_AT;
326 case ETH_P_MPLS_UC:
327 return NP_MPLS_UC;
328 case ETH_P_MPLS_MC:
329 return NP_MPLS_MC;
330 }
331 return -1;
332 }
333
334 /* Translates an NP index into an ethertype */
335 static const int npindex_to_ethertype[NUM_NP] = {
336 ETH_P_IP,
337 ETH_P_IPV6,
338 ETH_P_IPX,
339 ETH_P_PPPTALK,
340 ETH_P_MPLS_UC,
341 ETH_P_MPLS_MC,
342 };
343
344 /*
345 * Locking shorthand.
346 */
347 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
348 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
349 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
350 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
351 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
352 ppp_recv_lock(ppp); } while (0)
353 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
354 ppp_xmit_unlock(ppp); } while (0)
355
356 /*
357 * /dev/ppp device routines.
358 * The /dev/ppp device is used by pppd to control the ppp unit.
359 * It supports the read, write, ioctl and poll functions.
360 * Open instances of /dev/ppp can be in one of three states:
361 * unattached, attached to a ppp unit, or attached to a ppp channel.
362 */
363 static int ppp_open(struct inode *inode, struct file *file)
364 {
365 cycle_kernel_lock();
366 /*
367 * This could (should?) be enforced by the permissions on /dev/ppp.
368 */
369 if (!capable(CAP_NET_ADMIN))
370 return -EPERM;
371 return 0;
372 }
373
374 static int ppp_release(struct inode *unused, struct file *file)
375 {
376 struct ppp_file *pf = file->private_data;
377 struct ppp *ppp;
378
379 if (pf) {
380 file->private_data = NULL;
381 if (pf->kind == INTERFACE) {
382 ppp = PF_TO_PPP(pf);
383 if (file == ppp->owner)
384 ppp_shutdown_interface(ppp);
385 }
386 if (atomic_dec_and_test(&pf->refcnt)) {
387 switch (pf->kind) {
388 case INTERFACE:
389 ppp_destroy_interface(PF_TO_PPP(pf));
390 break;
391 case CHANNEL:
392 ppp_destroy_channel(PF_TO_CHANNEL(pf));
393 break;
394 }
395 }
396 }
397 return 0;
398 }
399
400 static ssize_t ppp_read(struct file *file, char __user *buf,
401 size_t count, loff_t *ppos)
402 {
403 struct ppp_file *pf = file->private_data;
404 DECLARE_WAITQUEUE(wait, current);
405 ssize_t ret;
406 struct sk_buff *skb = NULL;
407
408 ret = count;
409
410 if (!pf)
411 return -ENXIO;
412 add_wait_queue(&pf->rwait, &wait);
413 for (;;) {
414 set_current_state(TASK_INTERRUPTIBLE);
415 skb = skb_dequeue(&pf->rq);
416 if (skb)
417 break;
418 ret = 0;
419 if (pf->dead)
420 break;
421 if (pf->kind == INTERFACE) {
422 /*
423 * Return 0 (EOF) on an interface that has no
424 * channels connected, unless it is looping
425 * network traffic (demand mode).
426 */
427 struct ppp *ppp = PF_TO_PPP(pf);
428 if (ppp->n_channels == 0
429 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
430 break;
431 }
432 ret = -EAGAIN;
433 if (file->f_flags & O_NONBLOCK)
434 break;
435 ret = -ERESTARTSYS;
436 if (signal_pending(current))
437 break;
438 schedule();
439 }
440 set_current_state(TASK_RUNNING);
441 remove_wait_queue(&pf->rwait, &wait);
442
443 if (!skb)
444 goto out;
445
446 ret = -EOVERFLOW;
447 if (skb->len > count)
448 goto outf;
449 ret = -EFAULT;
450 if (copy_to_user(buf, skb->data, skb->len))
451 goto outf;
452 ret = skb->len;
453
454 outf:
455 kfree_skb(skb);
456 out:
457 return ret;
458 }
459
460 static ssize_t ppp_write(struct file *file, const char __user *buf,
461 size_t count, loff_t *ppos)
462 {
463 struct ppp_file *pf = file->private_data;
464 struct sk_buff *skb;
465 ssize_t ret;
466
467 if (!pf)
468 return -ENXIO;
469 ret = -ENOMEM;
470 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
471 if (!skb)
472 goto out;
473 skb_reserve(skb, pf->hdrlen);
474 ret = -EFAULT;
475 if (copy_from_user(skb_put(skb, count), buf, count)) {
476 kfree_skb(skb);
477 goto out;
478 }
479
480 skb_queue_tail(&pf->xq, skb);
481
482 switch (pf->kind) {
483 case INTERFACE:
484 ppp_xmit_process(PF_TO_PPP(pf));
485 break;
486 case CHANNEL:
487 ppp_channel_push(PF_TO_CHANNEL(pf));
488 break;
489 }
490
491 ret = count;
492
493 out:
494 return ret;
495 }
496
497 /* No kernel lock - fine */
498 static unsigned int ppp_poll(struct file *file, poll_table *wait)
499 {
500 struct ppp_file *pf = file->private_data;
501 unsigned int mask;
502
503 if (!pf)
504 return 0;
505 poll_wait(file, &pf->rwait, wait);
506 mask = POLLOUT | POLLWRNORM;
507 if (skb_peek(&pf->rq))
508 mask |= POLLIN | POLLRDNORM;
509 if (pf->dead)
510 mask |= POLLHUP;
511 else if (pf->kind == INTERFACE) {
512 /* see comment in ppp_read */
513 struct ppp *ppp = PF_TO_PPP(pf);
514 if (ppp->n_channels == 0
515 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
516 mask |= POLLIN | POLLRDNORM;
517 }
518
519 return mask;
520 }
521
522 #ifdef CONFIG_PPP_FILTER
523 static int get_filter(void __user *arg, struct sock_filter **p)
524 {
525 struct sock_fprog uprog;
526 struct sock_filter *code = NULL;
527 int len, err;
528
529 if (copy_from_user(&uprog, arg, sizeof(uprog)))
530 return -EFAULT;
531
532 if (!uprog.len) {
533 *p = NULL;
534 return 0;
535 }
536
537 len = uprog.len * sizeof(struct sock_filter);
538 code = kmalloc(len, GFP_KERNEL);
539 if (code == NULL)
540 return -ENOMEM;
541
542 if (copy_from_user(code, uprog.filter, len)) {
543 kfree(code);
544 return -EFAULT;
545 }
546
547 err = sk_chk_filter(code, uprog.len);
548 if (err) {
549 kfree(code);
550 return err;
551 }
552
553 *p = code;
554 return uprog.len;
555 }
556 #endif /* CONFIG_PPP_FILTER */
557
558 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
559 {
560 struct ppp_file *pf = file->private_data;
561 struct ppp *ppp;
562 int err = -EFAULT, val, val2, i;
563 struct ppp_idle idle;
564 struct npioctl npi;
565 int unit, cflags;
566 struct slcompress *vj;
567 void __user *argp = (void __user *)arg;
568 int __user *p = argp;
569
570 if (!pf)
571 return ppp_unattached_ioctl(current->nsproxy->net_ns,
572 pf, file, cmd, arg);
573
574 if (cmd == PPPIOCDETACH) {
575 /*
576 * We have to be careful here... if the file descriptor
577 * has been dup'd, we could have another process in the
578 * middle of a poll using the same file *, so we had
579 * better not free the interface data structures -
580 * instead we fail the ioctl. Even in this case, we
581 * shut down the interface if we are the owner of it.
582 * Actually, we should get rid of PPPIOCDETACH, userland
583 * (i.e. pppd) could achieve the same effect by closing
584 * this fd and reopening /dev/ppp.
585 */
586 err = -EINVAL;
587 lock_kernel();
588 if (pf->kind == INTERFACE) {
589 ppp = PF_TO_PPP(pf);
590 if (file == ppp->owner)
591 ppp_shutdown_interface(ppp);
592 }
593 if (atomic_long_read(&file->f_count) <= 2) {
594 ppp_release(NULL, file);
595 err = 0;
596 } else
597 printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%ld\n",
598 atomic_long_read(&file->f_count));
599 unlock_kernel();
600 return err;
601 }
602
603 if (pf->kind == CHANNEL) {
604 struct channel *pch;
605 struct ppp_channel *chan;
606
607 lock_kernel();
608 pch = PF_TO_CHANNEL(pf);
609
610 switch (cmd) {
611 case PPPIOCCONNECT:
612 if (get_user(unit, p))
613 break;
614 err = ppp_connect_channel(pch, unit);
615 break;
616
617 case PPPIOCDISCONN:
618 err = ppp_disconnect_channel(pch);
619 break;
620
621 default:
622 down_read(&pch->chan_sem);
623 chan = pch->chan;
624 err = -ENOTTY;
625 if (chan && chan->ops->ioctl)
626 err = chan->ops->ioctl(chan, cmd, arg);
627 up_read(&pch->chan_sem);
628 }
629 unlock_kernel();
630 return err;
631 }
632
633 if (pf->kind != INTERFACE) {
634 /* can't happen */
635 printk(KERN_ERR "PPP: not interface or channel??\n");
636 return -EINVAL;
637 }
638
639 lock_kernel();
640 ppp = PF_TO_PPP(pf);
641 switch (cmd) {
642 case PPPIOCSMRU:
643 if (get_user(val, p))
644 break;
645 ppp->mru = val;
646 err = 0;
647 break;
648
649 case PPPIOCSFLAGS:
650 if (get_user(val, p))
651 break;
652 ppp_lock(ppp);
653 cflags = ppp->flags & ~val;
654 ppp->flags = val & SC_FLAG_BITS;
655 ppp_unlock(ppp);
656 if (cflags & SC_CCP_OPEN)
657 ppp_ccp_closed(ppp);
658 err = 0;
659 break;
660
661 case PPPIOCGFLAGS:
662 val = ppp->flags | ppp->xstate | ppp->rstate;
663 if (put_user(val, p))
664 break;
665 err = 0;
666 break;
667
668 case PPPIOCSCOMPRESS:
669 err = ppp_set_compress(ppp, arg);
670 break;
671
672 case PPPIOCGUNIT:
673 if (put_user(ppp->file.index, p))
674 break;
675 err = 0;
676 break;
677
678 case PPPIOCSDEBUG:
679 if (get_user(val, p))
680 break;
681 ppp->debug = val;
682 err = 0;
683 break;
684
685 case PPPIOCGDEBUG:
686 if (put_user(ppp->debug, p))
687 break;
688 err = 0;
689 break;
690
691 case PPPIOCGIDLE:
692 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
693 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
694 if (copy_to_user(argp, &idle, sizeof(idle)))
695 break;
696 err = 0;
697 break;
698
699 case PPPIOCSMAXCID:
700 if (get_user(val, p))
701 break;
702 val2 = 15;
703 if ((val >> 16) != 0) {
704 val2 = val >> 16;
705 val &= 0xffff;
706 }
707 vj = slhc_init(val2+1, val+1);
708 if (!vj) {
709 printk(KERN_ERR "PPP: no memory (VJ compressor)\n");
710 err = -ENOMEM;
711 break;
712 }
713 ppp_lock(ppp);
714 if (ppp->vj)
715 slhc_free(ppp->vj);
716 ppp->vj = vj;
717 ppp_unlock(ppp);
718 err = 0;
719 break;
720
721 case PPPIOCGNPMODE:
722 case PPPIOCSNPMODE:
723 if (copy_from_user(&npi, argp, sizeof(npi)))
724 break;
725 err = proto_to_npindex(npi.protocol);
726 if (err < 0)
727 break;
728 i = err;
729 if (cmd == PPPIOCGNPMODE) {
730 err = -EFAULT;
731 npi.mode = ppp->npmode[i];
732 if (copy_to_user(argp, &npi, sizeof(npi)))
733 break;
734 } else {
735 ppp->npmode[i] = npi.mode;
736 /* we may be able to transmit more packets now (??) */
737 netif_wake_queue(ppp->dev);
738 }
739 err = 0;
740 break;
741
742 #ifdef CONFIG_PPP_FILTER
743 case PPPIOCSPASS:
744 {
745 struct sock_filter *code;
746 err = get_filter(argp, &code);
747 if (err >= 0) {
748 ppp_lock(ppp);
749 kfree(ppp->pass_filter);
750 ppp->pass_filter = code;
751 ppp->pass_len = err;
752 ppp_unlock(ppp);
753 err = 0;
754 }
755 break;
756 }
757 case PPPIOCSACTIVE:
758 {
759 struct sock_filter *code;
760 err = get_filter(argp, &code);
761 if (err >= 0) {
762 ppp_lock(ppp);
763 kfree(ppp->active_filter);
764 ppp->active_filter = code;
765 ppp->active_len = err;
766 ppp_unlock(ppp);
767 err = 0;
768 }
769 break;
770 }
771 #endif /* CONFIG_PPP_FILTER */
772
773 #ifdef CONFIG_PPP_MULTILINK
774 case PPPIOCSMRRU:
775 if (get_user(val, p))
776 break;
777 ppp_recv_lock(ppp);
778 ppp->mrru = val;
779 ppp_recv_unlock(ppp);
780 err = 0;
781 break;
782 #endif /* CONFIG_PPP_MULTILINK */
783
784 default:
785 err = -ENOTTY;
786 }
787 unlock_kernel();
788 return err;
789 }
790
791 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
792 struct file *file, unsigned int cmd, unsigned long arg)
793 {
794 int unit, err = -EFAULT;
795 struct ppp *ppp;
796 struct channel *chan;
797 struct ppp_net *pn;
798 int __user *p = (int __user *)arg;
799
800 lock_kernel();
801 switch (cmd) {
802 case PPPIOCNEWUNIT:
803 /* Create a new ppp unit */
804 if (get_user(unit, p))
805 break;
806 ppp = ppp_create_interface(net, unit, &err);
807 if (!ppp)
808 break;
809 file->private_data = &ppp->file;
810 ppp->owner = file;
811 err = -EFAULT;
812 if (put_user(ppp->file.index, p))
813 break;
814 err = 0;
815 break;
816
817 case PPPIOCATTACH:
818 /* Attach to an existing ppp unit */
819 if (get_user(unit, p))
820 break;
821 err = -ENXIO;
822 pn = ppp_pernet(net);
823 mutex_lock(&pn->all_ppp_mutex);
824 ppp = ppp_find_unit(pn, unit);
825 if (ppp) {
826 atomic_inc(&ppp->file.refcnt);
827 file->private_data = &ppp->file;
828 err = 0;
829 }
830 mutex_unlock(&pn->all_ppp_mutex);
831 break;
832
833 case PPPIOCATTCHAN:
834 if (get_user(unit, p))
835 break;
836 err = -ENXIO;
837 pn = ppp_pernet(net);
838 spin_lock_bh(&pn->all_channels_lock);
839 chan = ppp_find_channel(pn, unit);
840 if (chan) {
841 atomic_inc(&chan->file.refcnt);
842 file->private_data = &chan->file;
843 err = 0;
844 }
845 spin_unlock_bh(&pn->all_channels_lock);
846 break;
847
848 default:
849 err = -ENOTTY;
850 }
851 unlock_kernel();
852 return err;
853 }
854
855 static const struct file_operations ppp_device_fops = {
856 .owner = THIS_MODULE,
857 .read = ppp_read,
858 .write = ppp_write,
859 .poll = ppp_poll,
860 .unlocked_ioctl = ppp_ioctl,
861 .open = ppp_open,
862 .release = ppp_release
863 };
864
865 static __net_init int ppp_init_net(struct net *net)
866 {
867 struct ppp_net *pn;
868 int err;
869
870 pn = kzalloc(sizeof(*pn), GFP_KERNEL);
871 if (!pn)
872 return -ENOMEM;
873
874 idr_init(&pn->units_idr);
875 mutex_init(&pn->all_ppp_mutex);
876
877 INIT_LIST_HEAD(&pn->all_channels);
878 INIT_LIST_HEAD(&pn->new_channels);
879
880 spin_lock_init(&pn->all_channels_lock);
881
882 err = net_assign_generic(net, ppp_net_id, pn);
883 if (err) {
884 kfree(pn);
885 return err;
886 }
887
888 return 0;
889 }
890
891 static __net_exit void ppp_exit_net(struct net *net)
892 {
893 struct ppp_net *pn;
894
895 pn = net_generic(net, ppp_net_id);
896 idr_destroy(&pn->units_idr);
897 /*
898 * if someone has cached our net then
899 * further net_generic call will return NULL
900 */
901 net_assign_generic(net, ppp_net_id, NULL);
902 kfree(pn);
903 }
904
905 static struct pernet_operations ppp_net_ops = {
906 .init = ppp_init_net,
907 .exit = ppp_exit_net,
908 };
909
910 #define PPP_MAJOR 108
911
912 /* Called at boot time if ppp is compiled into the kernel,
913 or at module load time (from init_module) if compiled as a module. */
914 static int __init ppp_init(void)
915 {
916 int err;
917
918 printk(KERN_INFO "PPP generic driver version " PPP_VERSION "\n");
919
920 err = register_pernet_gen_device(&ppp_net_id, &ppp_net_ops);
921 if (err) {
922 printk(KERN_ERR "failed to register PPP pernet device (%d)\n", err);
923 goto out;
924 }
925
926 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
927 if (err) {
928 printk(KERN_ERR "failed to register PPP device (%d)\n", err);
929 goto out_net;
930 }
931
932 ppp_class = class_create(THIS_MODULE, "ppp");
933 if (IS_ERR(ppp_class)) {
934 err = PTR_ERR(ppp_class);
935 goto out_chrdev;
936 }
937
938 /* not a big deal if we fail here :-) */
939 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
940
941 return 0;
942
943 out_chrdev:
944 unregister_chrdev(PPP_MAJOR, "ppp");
945 out_net:
946 unregister_pernet_gen_device(ppp_net_id, &ppp_net_ops);
947 out:
948 return err;
949 }
950
951 /*
952 * Network interface unit routines.
953 */
954 static int
955 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
956 {
957 struct ppp *ppp = netdev_priv(dev);
958 int npi, proto;
959 unsigned char *pp;
960
961 npi = ethertype_to_npindex(ntohs(skb->protocol));
962 if (npi < 0)
963 goto outf;
964
965 /* Drop, accept or reject the packet */
966 switch (ppp->npmode[npi]) {
967 case NPMODE_PASS:
968 break;
969 case NPMODE_QUEUE:
970 /* it would be nice to have a way to tell the network
971 system to queue this one up for later. */
972 goto outf;
973 case NPMODE_DROP:
974 case NPMODE_ERROR:
975 goto outf;
976 }
977
978 /* Put the 2-byte PPP protocol number on the front,
979 making sure there is room for the address and control fields. */
980 if (skb_cow_head(skb, PPP_HDRLEN))
981 goto outf;
982
983 pp = skb_push(skb, 2);
984 proto = npindex_to_proto[npi];
985 pp[0] = proto >> 8;
986 pp[1] = proto;
987
988 netif_stop_queue(dev);
989 skb_queue_tail(&ppp->file.xq, skb);
990 ppp_xmit_process(ppp);
991 return 0;
992
993 outf:
994 kfree_skb(skb);
995 ++dev->stats.tx_dropped;
996 return 0;
997 }
998
999 static int
1000 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1001 {
1002 struct ppp *ppp = netdev_priv(dev);
1003 int err = -EFAULT;
1004 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
1005 struct ppp_stats stats;
1006 struct ppp_comp_stats cstats;
1007 char *vers;
1008
1009 switch (cmd) {
1010 case SIOCGPPPSTATS:
1011 ppp_get_stats(ppp, &stats);
1012 if (copy_to_user(addr, &stats, sizeof(stats)))
1013 break;
1014 err = 0;
1015 break;
1016
1017 case SIOCGPPPCSTATS:
1018 memset(&cstats, 0, sizeof(cstats));
1019 if (ppp->xc_state)
1020 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
1021 if (ppp->rc_state)
1022 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
1023 if (copy_to_user(addr, &cstats, sizeof(cstats)))
1024 break;
1025 err = 0;
1026 break;
1027
1028 case SIOCGPPPVER:
1029 vers = PPP_VERSION;
1030 if (copy_to_user(addr, vers, strlen(vers) + 1))
1031 break;
1032 err = 0;
1033 break;
1034
1035 default:
1036 err = -EINVAL;
1037 }
1038
1039 return err;
1040 }
1041
1042 static const struct net_device_ops ppp_netdev_ops = {
1043 .ndo_start_xmit = ppp_start_xmit,
1044 .ndo_do_ioctl = ppp_net_ioctl,
1045 };
1046
1047 static void ppp_setup(struct net_device *dev)
1048 {
1049 dev->netdev_ops = &ppp_netdev_ops;
1050 dev->hard_header_len = PPP_HDRLEN;
1051 dev->mtu = PPP_MTU;
1052 dev->addr_len = 0;
1053 dev->tx_queue_len = 3;
1054 dev->type = ARPHRD_PPP;
1055 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1056 dev->features |= NETIF_F_NETNS_LOCAL;
1057 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1058 }
1059
1060 /*
1061 * Transmit-side routines.
1062 */
1063
1064 /*
1065 * Called to do any work queued up on the transmit side
1066 * that can now be done.
1067 */
1068 static void
1069 ppp_xmit_process(struct ppp *ppp)
1070 {
1071 struct sk_buff *skb;
1072
1073 ppp_xmit_lock(ppp);
1074 if (!ppp->closing) {
1075 ppp_push(ppp);
1076 while (!ppp->xmit_pending
1077 && (skb = skb_dequeue(&ppp->file.xq)))
1078 ppp_send_frame(ppp, skb);
1079 /* If there's no work left to do, tell the core net
1080 code that we can accept some more. */
1081 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1082 netif_wake_queue(ppp->dev);
1083 }
1084 ppp_xmit_unlock(ppp);
1085 }
1086
1087 static inline struct sk_buff *
1088 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1089 {
1090 struct sk_buff *new_skb;
1091 int len;
1092 int new_skb_size = ppp->dev->mtu +
1093 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1094 int compressor_skb_size = ppp->dev->mtu +
1095 ppp->xcomp->comp_extra + PPP_HDRLEN;
1096 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1097 if (!new_skb) {
1098 if (net_ratelimit())
1099 printk(KERN_ERR "PPP: no memory (comp pkt)\n");
1100 return NULL;
1101 }
1102 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1103 skb_reserve(new_skb,
1104 ppp->dev->hard_header_len - PPP_HDRLEN);
1105
1106 /* compressor still expects A/C bytes in hdr */
1107 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1108 new_skb->data, skb->len + 2,
1109 compressor_skb_size);
1110 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1111 kfree_skb(skb);
1112 skb = new_skb;
1113 skb_put(skb, len);
1114 skb_pull(skb, 2); /* pull off A/C bytes */
1115 } else if (len == 0) {
1116 /* didn't compress, or CCP not up yet */
1117 kfree_skb(new_skb);
1118 new_skb = skb;
1119 } else {
1120 /*
1121 * (len < 0)
1122 * MPPE requires that we do not send unencrypted
1123 * frames. The compressor will return -1 if we
1124 * should drop the frame. We cannot simply test
1125 * the compress_proto because MPPE and MPPC share
1126 * the same number.
1127 */
1128 if (net_ratelimit())
1129 printk(KERN_ERR "ppp: compressor dropped pkt\n");
1130 kfree_skb(skb);
1131 kfree_skb(new_skb);
1132 new_skb = NULL;
1133 }
1134 return new_skb;
1135 }
1136
1137 /*
1138 * Compress and send a frame.
1139 * The caller should have locked the xmit path,
1140 * and xmit_pending should be 0.
1141 */
1142 static void
1143 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1144 {
1145 int proto = PPP_PROTO(skb);
1146 struct sk_buff *new_skb;
1147 int len;
1148 unsigned char *cp;
1149
1150 if (proto < 0x8000) {
1151 #ifdef CONFIG_PPP_FILTER
1152 /* check if we should pass this packet */
1153 /* the filter instructions are constructed assuming
1154 a four-byte PPP header on each packet */
1155 *skb_push(skb, 2) = 1;
1156 if (ppp->pass_filter
1157 && sk_run_filter(skb, ppp->pass_filter,
1158 ppp->pass_len) == 0) {
1159 if (ppp->debug & 1)
1160 printk(KERN_DEBUG "PPP: outbound frame not passed\n");
1161 kfree_skb(skb);
1162 return;
1163 }
1164 /* if this packet passes the active filter, record the time */
1165 if (!(ppp->active_filter
1166 && sk_run_filter(skb, ppp->active_filter,
1167 ppp->active_len) == 0))
1168 ppp->last_xmit = jiffies;
1169 skb_pull(skb, 2);
1170 #else
1171 /* for data packets, record the time */
1172 ppp->last_xmit = jiffies;
1173 #endif /* CONFIG_PPP_FILTER */
1174 }
1175
1176 ++ppp->dev->stats.tx_packets;
1177 ppp->dev->stats.tx_bytes += skb->len - 2;
1178
1179 switch (proto) {
1180 case PPP_IP:
1181 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1182 break;
1183 /* try to do VJ TCP header compression */
1184 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1185 GFP_ATOMIC);
1186 if (!new_skb) {
1187 printk(KERN_ERR "PPP: no memory (VJ comp pkt)\n");
1188 goto drop;
1189 }
1190 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1191 cp = skb->data + 2;
1192 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1193 new_skb->data + 2, &cp,
1194 !(ppp->flags & SC_NO_TCP_CCID));
1195 if (cp == skb->data + 2) {
1196 /* didn't compress */
1197 kfree_skb(new_skb);
1198 } else {
1199 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1200 proto = PPP_VJC_COMP;
1201 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1202 } else {
1203 proto = PPP_VJC_UNCOMP;
1204 cp[0] = skb->data[2];
1205 }
1206 kfree_skb(skb);
1207 skb = new_skb;
1208 cp = skb_put(skb, len + 2);
1209 cp[0] = 0;
1210 cp[1] = proto;
1211 }
1212 break;
1213
1214 case PPP_CCP:
1215 /* peek at outbound CCP frames */
1216 ppp_ccp_peek(ppp, skb, 0);
1217 break;
1218 }
1219
1220 /* try to do packet compression */
1221 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state
1222 && proto != PPP_LCP && proto != PPP_CCP) {
1223 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1224 if (net_ratelimit())
1225 printk(KERN_ERR "ppp: compression required but down - pkt dropped.\n");
1226 goto drop;
1227 }
1228 skb = pad_compress_skb(ppp, skb);
1229 if (!skb)
1230 goto drop;
1231 }
1232
1233 /*
1234 * If we are waiting for traffic (demand dialling),
1235 * queue it up for pppd to receive.
1236 */
1237 if (ppp->flags & SC_LOOP_TRAFFIC) {
1238 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1239 goto drop;
1240 skb_queue_tail(&ppp->file.rq, skb);
1241 wake_up_interruptible(&ppp->file.rwait);
1242 return;
1243 }
1244
1245 ppp->xmit_pending = skb;
1246 ppp_push(ppp);
1247 return;
1248
1249 drop:
1250 kfree_skb(skb);
1251 ++ppp->dev->stats.tx_errors;
1252 }
1253
1254 /*
1255 * Try to send the frame in xmit_pending.
1256 * The caller should have the xmit path locked.
1257 */
1258 static void
1259 ppp_push(struct ppp *ppp)
1260 {
1261 struct list_head *list;
1262 struct channel *pch;
1263 struct sk_buff *skb = ppp->xmit_pending;
1264
1265 if (!skb)
1266 return;
1267
1268 list = &ppp->channels;
1269 if (list_empty(list)) {
1270 /* nowhere to send the packet, just drop it */
1271 ppp->xmit_pending = NULL;
1272 kfree_skb(skb);
1273 return;
1274 }
1275
1276 if ((ppp->flags & SC_MULTILINK) == 0) {
1277 /* not doing multilink: send it down the first channel */
1278 list = list->next;
1279 pch = list_entry(list, struct channel, clist);
1280
1281 spin_lock_bh(&pch->downl);
1282 if (pch->chan) {
1283 if (pch->chan->ops->start_xmit(pch->chan, skb))
1284 ppp->xmit_pending = NULL;
1285 } else {
1286 /* channel got unregistered */
1287 kfree_skb(skb);
1288 ppp->xmit_pending = NULL;
1289 }
1290 spin_unlock_bh(&pch->downl);
1291 return;
1292 }
1293
1294 #ifdef CONFIG_PPP_MULTILINK
1295 /* Multilink: fragment the packet over as many links
1296 as can take the packet at the moment. */
1297 if (!ppp_mp_explode(ppp, skb))
1298 return;
1299 #endif /* CONFIG_PPP_MULTILINK */
1300
1301 ppp->xmit_pending = NULL;
1302 kfree_skb(skb);
1303 }
1304
1305 #ifdef CONFIG_PPP_MULTILINK
1306 /*
1307 * Divide a packet to be transmitted into fragments and
1308 * send them out the individual links.
1309 */
1310 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1311 {
1312 int len, totlen;
1313 int i, bits, hdrlen, mtu;
1314 int flen;
1315 int navail, nfree, nzero;
1316 int nbigger;
1317 int totspeed;
1318 int totfree;
1319 unsigned char *p, *q;
1320 struct list_head *list;
1321 struct channel *pch;
1322 struct sk_buff *frag;
1323 struct ppp_channel *chan;
1324
1325 totspeed = 0; /*total bitrate of the bundle*/
1326 nfree = 0; /* # channels which have no packet already queued */
1327 navail = 0; /* total # of usable channels (not deregistered) */
1328 nzero = 0; /* number of channels with zero speed associated*/
1329 totfree = 0; /*total # of channels available and
1330 *having no queued packets before
1331 *starting the fragmentation*/
1332
1333 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1334 i = 0;
1335 list_for_each_entry(pch, &ppp->channels, clist) {
1336 navail += pch->avail = (pch->chan != NULL);
1337 pch->speed = pch->chan->speed;
1338 if (pch->avail) {
1339 if (skb_queue_empty(&pch->file.xq) ||
1340 !pch->had_frag) {
1341 if (pch->speed == 0)
1342 nzero++;
1343 else
1344 totspeed += pch->speed;
1345
1346 pch->avail = 2;
1347 ++nfree;
1348 ++totfree;
1349 }
1350 if (!pch->had_frag && i < ppp->nxchan)
1351 ppp->nxchan = i;
1352 }
1353 ++i;
1354 }
1355 /*
1356 * Don't start sending this packet unless at least half of
1357 * the channels are free. This gives much better TCP
1358 * performance if we have a lot of channels.
1359 */
1360 if (nfree == 0 || nfree < navail / 2)
1361 return 0; /* can't take now, leave it in xmit_pending */
1362
1363 /* Do protocol field compression (XXX this should be optional) */
1364 p = skb->data;
1365 len = skb->len;
1366 if (*p == 0) {
1367 ++p;
1368 --len;
1369 }
1370
1371 totlen = len;
1372 nbigger = len % nfree;
1373
1374 /* skip to the channel after the one we last used
1375 and start at that one */
1376 list = &ppp->channels;
1377 for (i = 0; i < ppp->nxchan; ++i) {
1378 list = list->next;
1379 if (list == &ppp->channels) {
1380 i = 0;
1381 break;
1382 }
1383 }
1384
1385 /* create a fragment for each channel */
1386 bits = B;
1387 while (len > 0) {
1388 list = list->next;
1389 if (list == &ppp->channels) {
1390 i = 0;
1391 continue;
1392 }
1393 pch = list_entry(list, struct channel, clist);
1394 ++i;
1395 if (!pch->avail)
1396 continue;
1397
1398 /*
1399 * Skip this channel if it has a fragment pending already and
1400 * we haven't given a fragment to all of the free channels.
1401 */
1402 if (pch->avail == 1) {
1403 if (nfree > 0)
1404 continue;
1405 } else {
1406 pch->avail = 1;
1407 }
1408
1409 /* check the channel's mtu and whether it is still attached. */
1410 spin_lock_bh(&pch->downl);
1411 if (pch->chan == NULL) {
1412 /* can't use this channel, it's being deregistered */
1413 if (pch->speed == 0)
1414 nzero--;
1415 else
1416 totspeed -= pch->speed;
1417
1418 spin_unlock_bh(&pch->downl);
1419 pch->avail = 0;
1420 totlen = len;
1421 totfree--;
1422 nfree--;
1423 if (--navail == 0)
1424 break;
1425 continue;
1426 }
1427
1428 /*
1429 *if the channel speed is not set divide
1430 *the packet evenly among the free channels;
1431 *otherwise divide it according to the speed
1432 *of the channel we are going to transmit on
1433 */
1434 if (nfree > 0) {
1435 if (pch->speed == 0) {
1436 flen = totlen/nfree ;
1437 if (nbigger > 0) {
1438 flen++;
1439 nbigger--;
1440 }
1441 } else {
1442 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
1443 ((totspeed*totfree)/pch->speed)) - hdrlen;
1444 if (nbigger > 0) {
1445 flen += ((totfree - nzero)*pch->speed)/totspeed;
1446 nbigger -= ((totfree - nzero)*pch->speed)/
1447 totspeed;
1448 }
1449 }
1450 nfree--;
1451 }
1452
1453 /*
1454 *check if we are on the last channel or
1455 *we exceded the lenght of the data to
1456 *fragment
1457 */
1458 if ((nfree <= 0) || (flen > len))
1459 flen = len;
1460 /*
1461 *it is not worth to tx on slow channels:
1462 *in that case from the resulting flen according to the
1463 *above formula will be equal or less than zero.
1464 *Skip the channel in this case
1465 */
1466 if (flen <= 0) {
1467 pch->avail = 2;
1468 spin_unlock_bh(&pch->downl);
1469 continue;
1470 }
1471
1472 mtu = pch->chan->mtu - hdrlen;
1473 if (mtu < 4)
1474 mtu = 4;
1475 if (flen > mtu)
1476 flen = mtu;
1477 if (flen == len)
1478 bits |= E;
1479 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1480 if (!frag)
1481 goto noskb;
1482 q = skb_put(frag, flen + hdrlen);
1483
1484 /* make the MP header */
1485 q[0] = PPP_MP >> 8;
1486 q[1] = PPP_MP;
1487 if (ppp->flags & SC_MP_XSHORTSEQ) {
1488 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1489 q[3] = ppp->nxseq;
1490 } else {
1491 q[2] = bits;
1492 q[3] = ppp->nxseq >> 16;
1493 q[4] = ppp->nxseq >> 8;
1494 q[5] = ppp->nxseq;
1495 }
1496
1497 memcpy(q + hdrlen, p, flen);
1498
1499 /* try to send it down the channel */
1500 chan = pch->chan;
1501 if (!skb_queue_empty(&pch->file.xq) ||
1502 !chan->ops->start_xmit(chan, frag))
1503 skb_queue_tail(&pch->file.xq, frag);
1504 pch->had_frag = 1;
1505 p += flen;
1506 len -= flen;
1507 ++ppp->nxseq;
1508 bits = 0;
1509 spin_unlock_bh(&pch->downl);
1510 }
1511 ppp->nxchan = i;
1512
1513 return 1;
1514
1515 noskb:
1516 spin_unlock_bh(&pch->downl);
1517 if (ppp->debug & 1)
1518 printk(KERN_ERR "PPP: no memory (fragment)\n");
1519 ++ppp->dev->stats.tx_errors;
1520 ++ppp->nxseq;
1521 return 1; /* abandon the frame */
1522 }
1523 #endif /* CONFIG_PPP_MULTILINK */
1524
1525 /*
1526 * Try to send data out on a channel.
1527 */
1528 static void
1529 ppp_channel_push(struct channel *pch)
1530 {
1531 struct sk_buff *skb;
1532 struct ppp *ppp;
1533
1534 spin_lock_bh(&pch->downl);
1535 if (pch->chan) {
1536 while (!skb_queue_empty(&pch->file.xq)) {
1537 skb = skb_dequeue(&pch->file.xq);
1538 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1539 /* put the packet back and try again later */
1540 skb_queue_head(&pch->file.xq, skb);
1541 break;
1542 }
1543 }
1544 } else {
1545 /* channel got deregistered */
1546 skb_queue_purge(&pch->file.xq);
1547 }
1548 spin_unlock_bh(&pch->downl);
1549 /* see if there is anything from the attached unit to be sent */
1550 if (skb_queue_empty(&pch->file.xq)) {
1551 read_lock_bh(&pch->upl);
1552 ppp = pch->ppp;
1553 if (ppp)
1554 ppp_xmit_process(ppp);
1555 read_unlock_bh(&pch->upl);
1556 }
1557 }
1558
1559 /*
1560 * Receive-side routines.
1561 */
1562
1563 /* misuse a few fields of the skb for MP reconstruction */
1564 #define sequence priority
1565 #define BEbits cb[0]
1566
1567 static inline void
1568 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1569 {
1570 ppp_recv_lock(ppp);
1571 if (!ppp->closing)
1572 ppp_receive_frame(ppp, skb, pch);
1573 else
1574 kfree_skb(skb);
1575 ppp_recv_unlock(ppp);
1576 }
1577
1578 void
1579 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1580 {
1581 struct channel *pch = chan->ppp;
1582 int proto;
1583
1584 if (!pch || skb->len == 0) {
1585 kfree_skb(skb);
1586 return;
1587 }
1588
1589 proto = PPP_PROTO(skb);
1590 read_lock_bh(&pch->upl);
1591 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1592 /* put it on the channel queue */
1593 skb_queue_tail(&pch->file.rq, skb);
1594 /* drop old frames if queue too long */
1595 while (pch->file.rq.qlen > PPP_MAX_RQLEN
1596 && (skb = skb_dequeue(&pch->file.rq)))
1597 kfree_skb(skb);
1598 wake_up_interruptible(&pch->file.rwait);
1599 } else {
1600 ppp_do_recv(pch->ppp, skb, pch);
1601 }
1602 read_unlock_bh(&pch->upl);
1603 }
1604
1605 /* Put a 0-length skb in the receive queue as an error indication */
1606 void
1607 ppp_input_error(struct ppp_channel *chan, int code)
1608 {
1609 struct channel *pch = chan->ppp;
1610 struct sk_buff *skb;
1611
1612 if (!pch)
1613 return;
1614
1615 read_lock_bh(&pch->upl);
1616 if (pch->ppp) {
1617 skb = alloc_skb(0, GFP_ATOMIC);
1618 if (skb) {
1619 skb->len = 0; /* probably unnecessary */
1620 skb->cb[0] = code;
1621 ppp_do_recv(pch->ppp, skb, pch);
1622 }
1623 }
1624 read_unlock_bh(&pch->upl);
1625 }
1626
1627 /*
1628 * We come in here to process a received frame.
1629 * The receive side of the ppp unit is locked.
1630 */
1631 static void
1632 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1633 {
1634 if (pskb_may_pull(skb, 2)) {
1635 #ifdef CONFIG_PPP_MULTILINK
1636 /* XXX do channel-level decompression here */
1637 if (PPP_PROTO(skb) == PPP_MP)
1638 ppp_receive_mp_frame(ppp, skb, pch);
1639 else
1640 #endif /* CONFIG_PPP_MULTILINK */
1641 ppp_receive_nonmp_frame(ppp, skb);
1642 return;
1643 }
1644
1645 if (skb->len > 0)
1646 /* note: a 0-length skb is used as an error indication */
1647 ++ppp->dev->stats.rx_length_errors;
1648
1649 kfree_skb(skb);
1650 ppp_receive_error(ppp);
1651 }
1652
1653 static void
1654 ppp_receive_error(struct ppp *ppp)
1655 {
1656 ++ppp->dev->stats.rx_errors;
1657 if (ppp->vj)
1658 slhc_toss(ppp->vj);
1659 }
1660
1661 static void
1662 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1663 {
1664 struct sk_buff *ns;
1665 int proto, len, npi;
1666
1667 /*
1668 * Decompress the frame, if compressed.
1669 * Note that some decompressors need to see uncompressed frames
1670 * that come in as well as compressed frames.
1671 */
1672 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)
1673 && (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1674 skb = ppp_decompress_frame(ppp, skb);
1675
1676 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1677 goto err;
1678
1679 proto = PPP_PROTO(skb);
1680 switch (proto) {
1681 case PPP_VJC_COMP:
1682 /* decompress VJ compressed packets */
1683 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1684 goto err;
1685
1686 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1687 /* copy to a new sk_buff with more tailroom */
1688 ns = dev_alloc_skb(skb->len + 128);
1689 if (!ns) {
1690 printk(KERN_ERR"PPP: no memory (VJ decomp)\n");
1691 goto err;
1692 }
1693 skb_reserve(ns, 2);
1694 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1695 kfree_skb(skb);
1696 skb = ns;
1697 }
1698 else
1699 skb->ip_summed = CHECKSUM_NONE;
1700
1701 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1702 if (len <= 0) {
1703 printk(KERN_DEBUG "PPP: VJ decompression error\n");
1704 goto err;
1705 }
1706 len += 2;
1707 if (len > skb->len)
1708 skb_put(skb, len - skb->len);
1709 else if (len < skb->len)
1710 skb_trim(skb, len);
1711 proto = PPP_IP;
1712 break;
1713
1714 case PPP_VJC_UNCOMP:
1715 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1716 goto err;
1717
1718 /* Until we fix the decompressor need to make sure
1719 * data portion is linear.
1720 */
1721 if (!pskb_may_pull(skb, skb->len))
1722 goto err;
1723
1724 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1725 printk(KERN_ERR "PPP: VJ uncompressed error\n");
1726 goto err;
1727 }
1728 proto = PPP_IP;
1729 break;
1730
1731 case PPP_CCP:
1732 ppp_ccp_peek(ppp, skb, 1);
1733 break;
1734 }
1735
1736 ++ppp->dev->stats.rx_packets;
1737 ppp->dev->stats.rx_bytes += skb->len - 2;
1738
1739 npi = proto_to_npindex(proto);
1740 if (npi < 0) {
1741 /* control or unknown frame - pass it to pppd */
1742 skb_queue_tail(&ppp->file.rq, skb);
1743 /* limit queue length by dropping old frames */
1744 while (ppp->file.rq.qlen > PPP_MAX_RQLEN
1745 && (skb = skb_dequeue(&ppp->file.rq)))
1746 kfree_skb(skb);
1747 /* wake up any process polling or blocking on read */
1748 wake_up_interruptible(&ppp->file.rwait);
1749
1750 } else {
1751 /* network protocol frame - give it to the kernel */
1752
1753 #ifdef CONFIG_PPP_FILTER
1754 /* check if the packet passes the pass and active filters */
1755 /* the filter instructions are constructed assuming
1756 a four-byte PPP header on each packet */
1757 if (ppp->pass_filter || ppp->active_filter) {
1758 if (skb_cloned(skb) &&
1759 pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
1760 goto err;
1761
1762 *skb_push(skb, 2) = 0;
1763 if (ppp->pass_filter
1764 && sk_run_filter(skb, ppp->pass_filter,
1765 ppp->pass_len) == 0) {
1766 if (ppp->debug & 1)
1767 printk(KERN_DEBUG "PPP: inbound frame "
1768 "not passed\n");
1769 kfree_skb(skb);
1770 return;
1771 }
1772 if (!(ppp->active_filter
1773 && sk_run_filter(skb, ppp->active_filter,
1774 ppp->active_len) == 0))
1775 ppp->last_recv = jiffies;
1776 __skb_pull(skb, 2);
1777 } else
1778 #endif /* CONFIG_PPP_FILTER */
1779 ppp->last_recv = jiffies;
1780
1781 if ((ppp->dev->flags & IFF_UP) == 0
1782 || ppp->npmode[npi] != NPMODE_PASS) {
1783 kfree_skb(skb);
1784 } else {
1785 /* chop off protocol */
1786 skb_pull_rcsum(skb, 2);
1787 skb->dev = ppp->dev;
1788 skb->protocol = htons(npindex_to_ethertype[npi]);
1789 skb_reset_mac_header(skb);
1790 netif_rx(skb);
1791 }
1792 }
1793 return;
1794
1795 err:
1796 kfree_skb(skb);
1797 ppp_receive_error(ppp);
1798 }
1799
1800 static struct sk_buff *
1801 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1802 {
1803 int proto = PPP_PROTO(skb);
1804 struct sk_buff *ns;
1805 int len;
1806
1807 /* Until we fix all the decompressor's need to make sure
1808 * data portion is linear.
1809 */
1810 if (!pskb_may_pull(skb, skb->len))
1811 goto err;
1812
1813 if (proto == PPP_COMP) {
1814 int obuff_size;
1815
1816 switch(ppp->rcomp->compress_proto) {
1817 case CI_MPPE:
1818 obuff_size = ppp->mru + PPP_HDRLEN + 1;
1819 break;
1820 default:
1821 obuff_size = ppp->mru + PPP_HDRLEN;
1822 break;
1823 }
1824
1825 ns = dev_alloc_skb(obuff_size);
1826 if (!ns) {
1827 printk(KERN_ERR "ppp_decompress_frame: no memory\n");
1828 goto err;
1829 }
1830 /* the decompressor still expects the A/C bytes in the hdr */
1831 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1832 skb->len + 2, ns->data, obuff_size);
1833 if (len < 0) {
1834 /* Pass the compressed frame to pppd as an
1835 error indication. */
1836 if (len == DECOMP_FATALERROR)
1837 ppp->rstate |= SC_DC_FERROR;
1838 kfree_skb(ns);
1839 goto err;
1840 }
1841
1842 kfree_skb(skb);
1843 skb = ns;
1844 skb_put(skb, len);
1845 skb_pull(skb, 2); /* pull off the A/C bytes */
1846
1847 } else {
1848 /* Uncompressed frame - pass to decompressor so it
1849 can update its dictionary if necessary. */
1850 if (ppp->rcomp->incomp)
1851 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1852 skb->len + 2);
1853 }
1854
1855 return skb;
1856
1857 err:
1858 ppp->rstate |= SC_DC_ERROR;
1859 ppp_receive_error(ppp);
1860 return skb;
1861 }
1862
1863 #ifdef CONFIG_PPP_MULTILINK
1864 /*
1865 * Receive a multilink frame.
1866 * We put it on the reconstruction queue and then pull off
1867 * as many completed frames as we can.
1868 */
1869 static void
1870 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1871 {
1872 u32 mask, seq;
1873 struct channel *ch;
1874 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1875
1876 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
1877 goto err; /* no good, throw it away */
1878
1879 /* Decode sequence number and begin/end bits */
1880 if (ppp->flags & SC_MP_SHORTSEQ) {
1881 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1882 mask = 0xfff;
1883 } else {
1884 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1885 mask = 0xffffff;
1886 }
1887 skb->BEbits = skb->data[2];
1888 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
1889
1890 /*
1891 * Do protocol ID decompression on the first fragment of each packet.
1892 */
1893 if ((skb->BEbits & B) && (skb->data[0] & 1))
1894 *skb_push(skb, 1) = 0;
1895
1896 /*
1897 * Expand sequence number to 32 bits, making it as close
1898 * as possible to ppp->minseq.
1899 */
1900 seq |= ppp->minseq & ~mask;
1901 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
1902 seq += mask + 1;
1903 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
1904 seq -= mask + 1; /* should never happen */
1905 skb->sequence = seq;
1906 pch->lastseq = seq;
1907
1908 /*
1909 * If this packet comes before the next one we were expecting,
1910 * drop it.
1911 */
1912 if (seq_before(seq, ppp->nextseq)) {
1913 kfree_skb(skb);
1914 ++ppp->dev->stats.rx_dropped;
1915 ppp_receive_error(ppp);
1916 return;
1917 }
1918
1919 /*
1920 * Reevaluate minseq, the minimum over all channels of the
1921 * last sequence number received on each channel. Because of
1922 * the increasing sequence number rule, we know that any fragment
1923 * before `minseq' which hasn't arrived is never going to arrive.
1924 * The list of channels can't change because we have the receive
1925 * side of the ppp unit locked.
1926 */
1927 list_for_each_entry(ch, &ppp->channels, clist) {
1928 if (seq_before(ch->lastseq, seq))
1929 seq = ch->lastseq;
1930 }
1931 if (seq_before(ppp->minseq, seq))
1932 ppp->minseq = seq;
1933
1934 /* Put the fragment on the reconstruction queue */
1935 ppp_mp_insert(ppp, skb);
1936
1937 /* If the queue is getting long, don't wait any longer for packets
1938 before the start of the queue. */
1939 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
1940 struct sk_buff *skb = skb_peek(&ppp->mrq);
1941 if (seq_before(ppp->minseq, skb->sequence))
1942 ppp->minseq = skb->sequence;
1943 }
1944
1945 /* Pull completed packets off the queue and receive them. */
1946 while ((skb = ppp_mp_reconstruct(ppp)))
1947 ppp_receive_nonmp_frame(ppp, skb);
1948
1949 return;
1950
1951 err:
1952 kfree_skb(skb);
1953 ppp_receive_error(ppp);
1954 }
1955
1956 /*
1957 * Insert a fragment on the MP reconstruction queue.
1958 * The queue is ordered by increasing sequence number.
1959 */
1960 static void
1961 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
1962 {
1963 struct sk_buff *p;
1964 struct sk_buff_head *list = &ppp->mrq;
1965 u32 seq = skb->sequence;
1966
1967 /* N.B. we don't need to lock the list lock because we have the
1968 ppp unit receive-side lock. */
1969 skb_queue_walk(list, p) {
1970 if (seq_before(seq, p->sequence))
1971 break;
1972 }
1973 __skb_queue_before(list, p, skb);
1974 }
1975
1976 /*
1977 * Reconstruct a packet from the MP fragment queue.
1978 * We go through increasing sequence numbers until we find a
1979 * complete packet, or we get to the sequence number for a fragment
1980 * which hasn't arrived but might still do so.
1981 */
1982 static struct sk_buff *
1983 ppp_mp_reconstruct(struct ppp *ppp)
1984 {
1985 u32 seq = ppp->nextseq;
1986 u32 minseq = ppp->minseq;
1987 struct sk_buff_head *list = &ppp->mrq;
1988 struct sk_buff *p, *next;
1989 struct sk_buff *head, *tail;
1990 struct sk_buff *skb = NULL;
1991 int lost = 0, len = 0;
1992
1993 if (ppp->mrru == 0) /* do nothing until mrru is set */
1994 return NULL;
1995 head = list->next;
1996 tail = NULL;
1997 for (p = head; p != (struct sk_buff *) list; p = next) {
1998 next = p->next;
1999 if (seq_before(p->sequence, seq)) {
2000 /* this can't happen, anyway ignore the skb */
2001 printk(KERN_ERR "ppp_mp_reconstruct bad seq %u < %u\n",
2002 p->sequence, seq);
2003 head = next;
2004 continue;
2005 }
2006 if (p->sequence != seq) {
2007 /* Fragment `seq' is missing. If it is after
2008 minseq, it might arrive later, so stop here. */
2009 if (seq_after(seq, minseq))
2010 break;
2011 /* Fragment `seq' is lost, keep going. */
2012 lost = 1;
2013 seq = seq_before(minseq, p->sequence)?
2014 minseq + 1: p->sequence;
2015 next = p;
2016 continue;
2017 }
2018
2019 /*
2020 * At this point we know that all the fragments from
2021 * ppp->nextseq to seq are either present or lost.
2022 * Also, there are no complete packets in the queue
2023 * that have no missing fragments and end before this
2024 * fragment.
2025 */
2026
2027 /* B bit set indicates this fragment starts a packet */
2028 if (p->BEbits & B) {
2029 head = p;
2030 lost = 0;
2031 len = 0;
2032 }
2033
2034 len += p->len;
2035
2036 /* Got a complete packet yet? */
2037 if (lost == 0 && (p->BEbits & E) && (head->BEbits & B)) {
2038 if (len > ppp->mrru + 2) {
2039 ++ppp->dev->stats.rx_length_errors;
2040 printk(KERN_DEBUG "PPP: reconstructed packet"
2041 " is too long (%d)\n", len);
2042 } else if (p == head) {
2043 /* fragment is complete packet - reuse skb */
2044 tail = p;
2045 skb = skb_get(p);
2046 break;
2047 } else if ((skb = dev_alloc_skb(len)) == NULL) {
2048 ++ppp->dev->stats.rx_missed_errors;
2049 printk(KERN_DEBUG "PPP: no memory for "
2050 "reconstructed packet");
2051 } else {
2052 tail = p;
2053 break;
2054 }
2055 ppp->nextseq = seq + 1;
2056 }
2057
2058 /*
2059 * If this is the ending fragment of a packet,
2060 * and we haven't found a complete valid packet yet,
2061 * we can discard up to and including this fragment.
2062 */
2063 if (p->BEbits & E)
2064 head = next;
2065
2066 ++seq;
2067 }
2068
2069 /* If we have a complete packet, copy it all into one skb. */
2070 if (tail != NULL) {
2071 /* If we have discarded any fragments,
2072 signal a receive error. */
2073 if (head->sequence != ppp->nextseq) {
2074 if (ppp->debug & 1)
2075 printk(KERN_DEBUG " missed pkts %u..%u\n",
2076 ppp->nextseq, head->sequence-1);
2077 ++ppp->dev->stats.rx_dropped;
2078 ppp_receive_error(ppp);
2079 }
2080
2081 if (head != tail)
2082 /* copy to a single skb */
2083 for (p = head; p != tail->next; p = p->next)
2084 skb_copy_bits(p, 0, skb_put(skb, p->len), p->len);
2085 ppp->nextseq = tail->sequence + 1;
2086 head = tail->next;
2087 }
2088
2089 /* Discard all the skbuffs that we have copied the data out of
2090 or that we can't use. */
2091 while ((p = list->next) != head) {
2092 __skb_unlink(p, list);
2093 kfree_skb(p);
2094 }
2095
2096 return skb;
2097 }
2098 #endif /* CONFIG_PPP_MULTILINK */
2099
2100 /*
2101 * Channel interface.
2102 */
2103
2104 /* Create a new, unattached ppp channel. */
2105 int ppp_register_channel(struct ppp_channel *chan)
2106 {
2107 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2108 }
2109
2110 /* Create a new, unattached ppp channel for specified net. */
2111 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
2112 {
2113 struct channel *pch;
2114 struct ppp_net *pn;
2115
2116 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2117 if (!pch)
2118 return -ENOMEM;
2119
2120 pn = ppp_pernet(net);
2121
2122 pch->ppp = NULL;
2123 pch->chan = chan;
2124 pch->chan_net = net;
2125 chan->ppp = pch;
2126 init_ppp_file(&pch->file, CHANNEL);
2127 pch->file.hdrlen = chan->hdrlen;
2128 #ifdef CONFIG_PPP_MULTILINK
2129 pch->lastseq = -1;
2130 #endif /* CONFIG_PPP_MULTILINK */
2131 init_rwsem(&pch->chan_sem);
2132 spin_lock_init(&pch->downl);
2133 rwlock_init(&pch->upl);
2134
2135 spin_lock_bh(&pn->all_channels_lock);
2136 pch->file.index = ++pn->last_channel_index;
2137 list_add(&pch->list, &pn->new_channels);
2138 atomic_inc(&channel_count);
2139 spin_unlock_bh(&pn->all_channels_lock);
2140
2141 return 0;
2142 }
2143
2144 /*
2145 * Return the index of a channel.
2146 */
2147 int ppp_channel_index(struct ppp_channel *chan)
2148 {
2149 struct channel *pch = chan->ppp;
2150
2151 if (pch)
2152 return pch->file.index;
2153 return -1;
2154 }
2155
2156 /*
2157 * Return the PPP unit number to which a channel is connected.
2158 */
2159 int ppp_unit_number(struct ppp_channel *chan)
2160 {
2161 struct channel *pch = chan->ppp;
2162 int unit = -1;
2163
2164 if (pch) {
2165 read_lock_bh(&pch->upl);
2166 if (pch->ppp)
2167 unit = pch->ppp->file.index;
2168 read_unlock_bh(&pch->upl);
2169 }
2170 return unit;
2171 }
2172
2173 /*
2174 * Disconnect a channel from the generic layer.
2175 * This must be called in process context.
2176 */
2177 void
2178 ppp_unregister_channel(struct ppp_channel *chan)
2179 {
2180 struct channel *pch = chan->ppp;
2181 struct ppp_net *pn;
2182
2183 if (!pch)
2184 return; /* should never happen */
2185
2186 chan->ppp = NULL;
2187
2188 /*
2189 * This ensures that we have returned from any calls into the
2190 * the channel's start_xmit or ioctl routine before we proceed.
2191 */
2192 down_write(&pch->chan_sem);
2193 spin_lock_bh(&pch->downl);
2194 pch->chan = NULL;
2195 spin_unlock_bh(&pch->downl);
2196 up_write(&pch->chan_sem);
2197 ppp_disconnect_channel(pch);
2198
2199 pn = ppp_pernet(pch->chan_net);
2200 spin_lock_bh(&pn->all_channels_lock);
2201 list_del(&pch->list);
2202 spin_unlock_bh(&pn->all_channels_lock);
2203
2204 pch->file.dead = 1;
2205 wake_up_interruptible(&pch->file.rwait);
2206 if (atomic_dec_and_test(&pch->file.refcnt))
2207 ppp_destroy_channel(pch);
2208 }
2209
2210 /*
2211 * Callback from a channel when it can accept more to transmit.
2212 * This should be called at BH/softirq level, not interrupt level.
2213 */
2214 void
2215 ppp_output_wakeup(struct ppp_channel *chan)
2216 {
2217 struct channel *pch = chan->ppp;
2218
2219 if (!pch)
2220 return;
2221 ppp_channel_push(pch);
2222 }
2223
2224 /*
2225 * Compression control.
2226 */
2227
2228 /* Process the PPPIOCSCOMPRESS ioctl. */
2229 static int
2230 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2231 {
2232 int err;
2233 struct compressor *cp, *ocomp;
2234 struct ppp_option_data data;
2235 void *state, *ostate;
2236 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2237
2238 err = -EFAULT;
2239 if (copy_from_user(&data, (void __user *) arg, sizeof(data))
2240 || (data.length <= CCP_MAX_OPTION_LENGTH
2241 && copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2242 goto out;
2243 err = -EINVAL;
2244 if (data.length > CCP_MAX_OPTION_LENGTH
2245 || ccp_option[1] < 2 || ccp_option[1] > data.length)
2246 goto out;
2247
2248 cp = try_then_request_module(
2249 find_compressor(ccp_option[0]),
2250 "ppp-compress-%d", ccp_option[0]);
2251 if (!cp)
2252 goto out;
2253
2254 err = -ENOBUFS;
2255 if (data.transmit) {
2256 state = cp->comp_alloc(ccp_option, data.length);
2257 if (state) {
2258 ppp_xmit_lock(ppp);
2259 ppp->xstate &= ~SC_COMP_RUN;
2260 ocomp = ppp->xcomp;
2261 ostate = ppp->xc_state;
2262 ppp->xcomp = cp;
2263 ppp->xc_state = state;
2264 ppp_xmit_unlock(ppp);
2265 if (ostate) {
2266 ocomp->comp_free(ostate);
2267 module_put(ocomp->owner);
2268 }
2269 err = 0;
2270 } else
2271 module_put(cp->owner);
2272
2273 } else {
2274 state = cp->decomp_alloc(ccp_option, data.length);
2275 if (state) {
2276 ppp_recv_lock(ppp);
2277 ppp->rstate &= ~SC_DECOMP_RUN;
2278 ocomp = ppp->rcomp;
2279 ostate = ppp->rc_state;
2280 ppp->rcomp = cp;
2281 ppp->rc_state = state;
2282 ppp_recv_unlock(ppp);
2283 if (ostate) {
2284 ocomp->decomp_free(ostate);
2285 module_put(ocomp->owner);
2286 }
2287 err = 0;
2288 } else
2289 module_put(cp->owner);
2290 }
2291
2292 out:
2293 return err;
2294 }
2295
2296 /*
2297 * Look at a CCP packet and update our state accordingly.
2298 * We assume the caller has the xmit or recv path locked.
2299 */
2300 static void
2301 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2302 {
2303 unsigned char *dp;
2304 int len;
2305
2306 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2307 return; /* no header */
2308 dp = skb->data + 2;
2309
2310 switch (CCP_CODE(dp)) {
2311 case CCP_CONFREQ:
2312
2313 /* A ConfReq starts negotiation of compression
2314 * in one direction of transmission,
2315 * and hence brings it down...but which way?
2316 *
2317 * Remember:
2318 * A ConfReq indicates what the sender would like to receive
2319 */
2320 if(inbound)
2321 /* He is proposing what I should send */
2322 ppp->xstate &= ~SC_COMP_RUN;
2323 else
2324 /* I am proposing to what he should send */
2325 ppp->rstate &= ~SC_DECOMP_RUN;
2326
2327 break;
2328
2329 case CCP_TERMREQ:
2330 case CCP_TERMACK:
2331 /*
2332 * CCP is going down, both directions of transmission
2333 */
2334 ppp->rstate &= ~SC_DECOMP_RUN;
2335 ppp->xstate &= ~SC_COMP_RUN;
2336 break;
2337
2338 case CCP_CONFACK:
2339 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2340 break;
2341 len = CCP_LENGTH(dp);
2342 if (!pskb_may_pull(skb, len + 2))
2343 return; /* too short */
2344 dp += CCP_HDRLEN;
2345 len -= CCP_HDRLEN;
2346 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2347 break;
2348 if (inbound) {
2349 /* we will start receiving compressed packets */
2350 if (!ppp->rc_state)
2351 break;
2352 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2353 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2354 ppp->rstate |= SC_DECOMP_RUN;
2355 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2356 }
2357 } else {
2358 /* we will soon start sending compressed packets */
2359 if (!ppp->xc_state)
2360 break;
2361 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2362 ppp->file.index, 0, ppp->debug))
2363 ppp->xstate |= SC_COMP_RUN;
2364 }
2365 break;
2366
2367 case CCP_RESETACK:
2368 /* reset the [de]compressor */
2369 if ((ppp->flags & SC_CCP_UP) == 0)
2370 break;
2371 if (inbound) {
2372 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2373 ppp->rcomp->decomp_reset(ppp->rc_state);
2374 ppp->rstate &= ~SC_DC_ERROR;
2375 }
2376 } else {
2377 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2378 ppp->xcomp->comp_reset(ppp->xc_state);
2379 }
2380 break;
2381 }
2382 }
2383
2384 /* Free up compression resources. */
2385 static void
2386 ppp_ccp_closed(struct ppp *ppp)
2387 {
2388 void *xstate, *rstate;
2389 struct compressor *xcomp, *rcomp;
2390
2391 ppp_lock(ppp);
2392 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2393 ppp->xstate = 0;
2394 xcomp = ppp->xcomp;
2395 xstate = ppp->xc_state;
2396 ppp->xc_state = NULL;
2397 ppp->rstate = 0;
2398 rcomp = ppp->rcomp;
2399 rstate = ppp->rc_state;
2400 ppp->rc_state = NULL;
2401 ppp_unlock(ppp);
2402
2403 if (xstate) {
2404 xcomp->comp_free(xstate);
2405 module_put(xcomp->owner);
2406 }
2407 if (rstate) {
2408 rcomp->decomp_free(rstate);
2409 module_put(rcomp->owner);
2410 }
2411 }
2412
2413 /* List of compressors. */
2414 static LIST_HEAD(compressor_list);
2415 static DEFINE_SPINLOCK(compressor_list_lock);
2416
2417 struct compressor_entry {
2418 struct list_head list;
2419 struct compressor *comp;
2420 };
2421
2422 static struct compressor_entry *
2423 find_comp_entry(int proto)
2424 {
2425 struct compressor_entry *ce;
2426
2427 list_for_each_entry(ce, &compressor_list, list) {
2428 if (ce->comp->compress_proto == proto)
2429 return ce;
2430 }
2431 return NULL;
2432 }
2433
2434 /* Register a compressor */
2435 int
2436 ppp_register_compressor(struct compressor *cp)
2437 {
2438 struct compressor_entry *ce;
2439 int ret;
2440 spin_lock(&compressor_list_lock);
2441 ret = -EEXIST;
2442 if (find_comp_entry(cp->compress_proto))
2443 goto out;
2444 ret = -ENOMEM;
2445 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2446 if (!ce)
2447 goto out;
2448 ret = 0;
2449 ce->comp = cp;
2450 list_add(&ce->list, &compressor_list);
2451 out:
2452 spin_unlock(&compressor_list_lock);
2453 return ret;
2454 }
2455
2456 /* Unregister a compressor */
2457 void
2458 ppp_unregister_compressor(struct compressor *cp)
2459 {
2460 struct compressor_entry *ce;
2461
2462 spin_lock(&compressor_list_lock);
2463 ce = find_comp_entry(cp->compress_proto);
2464 if (ce && ce->comp == cp) {
2465 list_del(&ce->list);
2466 kfree(ce);
2467 }
2468 spin_unlock(&compressor_list_lock);
2469 }
2470
2471 /* Find a compressor. */
2472 static struct compressor *
2473 find_compressor(int type)
2474 {
2475 struct compressor_entry *ce;
2476 struct compressor *cp = NULL;
2477
2478 spin_lock(&compressor_list_lock);
2479 ce = find_comp_entry(type);
2480 if (ce) {
2481 cp = ce->comp;
2482 if (!try_module_get(cp->owner))
2483 cp = NULL;
2484 }
2485 spin_unlock(&compressor_list_lock);
2486 return cp;
2487 }
2488
2489 /*
2490 * Miscelleneous stuff.
2491 */
2492
2493 static void
2494 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2495 {
2496 struct slcompress *vj = ppp->vj;
2497
2498 memset(st, 0, sizeof(*st));
2499 st->p.ppp_ipackets = ppp->dev->stats.rx_packets;
2500 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2501 st->p.ppp_ibytes = ppp->dev->stats.rx_bytes;
2502 st->p.ppp_opackets = ppp->dev->stats.tx_packets;
2503 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2504 st->p.ppp_obytes = ppp->dev->stats.tx_bytes;
2505 if (!vj)
2506 return;
2507 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2508 st->vj.vjs_compressed = vj->sls_o_compressed;
2509 st->vj.vjs_searches = vj->sls_o_searches;
2510 st->vj.vjs_misses = vj->sls_o_misses;
2511 st->vj.vjs_errorin = vj->sls_i_error;
2512 st->vj.vjs_tossed = vj->sls_i_tossed;
2513 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2514 st->vj.vjs_compressedin = vj->sls_i_compressed;
2515 }
2516
2517 /*
2518 * Stuff for handling the lists of ppp units and channels
2519 * and for initialization.
2520 */
2521
2522 /*
2523 * Create a new ppp interface unit. Fails if it can't allocate memory
2524 * or if there is already a unit with the requested number.
2525 * unit == -1 means allocate a new number.
2526 */
2527 static struct ppp *
2528 ppp_create_interface(struct net *net, int unit, int *retp)
2529 {
2530 struct ppp *ppp;
2531 struct ppp_net *pn;
2532 struct net_device *dev = NULL;
2533 int ret = -ENOMEM;
2534 int i;
2535
2536 dev = alloc_netdev(sizeof(struct ppp), "", ppp_setup);
2537 if (!dev)
2538 goto out1;
2539
2540 pn = ppp_pernet(net);
2541
2542 ppp = netdev_priv(dev);
2543 ppp->dev = dev;
2544 ppp->mru = PPP_MRU;
2545 init_ppp_file(&ppp->file, INTERFACE);
2546 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2547 for (i = 0; i < NUM_NP; ++i)
2548 ppp->npmode[i] = NPMODE_PASS;
2549 INIT_LIST_HEAD(&ppp->channels);
2550 spin_lock_init(&ppp->rlock);
2551 spin_lock_init(&ppp->wlock);
2552 #ifdef CONFIG_PPP_MULTILINK
2553 ppp->minseq = -1;
2554 skb_queue_head_init(&ppp->mrq);
2555 #endif /* CONFIG_PPP_MULTILINK */
2556
2557 /*
2558 * drum roll: don't forget to set
2559 * the net device is belong to
2560 */
2561 dev_net_set(dev, net);
2562
2563 ret = -EEXIST;
2564 mutex_lock(&pn->all_ppp_mutex);
2565
2566 if (unit < 0) {
2567 unit = unit_get(&pn->units_idr, ppp);
2568 if (unit < 0) {
2569 *retp = unit;
2570 goto out2;
2571 }
2572 } else {
2573 if (unit_find(&pn->units_idr, unit))
2574 goto out2; /* unit already exists */
2575 /*
2576 * if caller need a specified unit number
2577 * lets try to satisfy him, otherwise --
2578 * he should better ask us for new unit number
2579 *
2580 * NOTE: yes I know that returning EEXIST it's not
2581 * fair but at least pppd will ask us to allocate
2582 * new unit in this case so user is happy :)
2583 */
2584 unit = unit_set(&pn->units_idr, ppp, unit);
2585 if (unit < 0)
2586 goto out2;
2587 }
2588
2589 /* Initialize the new ppp unit */
2590 ppp->file.index = unit;
2591 sprintf(dev->name, "ppp%d", unit);
2592
2593 ret = register_netdev(dev);
2594 if (ret != 0) {
2595 unit_put(&pn->units_idr, unit);
2596 printk(KERN_ERR "PPP: couldn't register device %s (%d)\n",
2597 dev->name, ret);
2598 goto out2;
2599 }
2600
2601 ppp->ppp_net = net;
2602
2603 atomic_inc(&ppp_unit_count);
2604 mutex_unlock(&pn->all_ppp_mutex);
2605
2606 *retp = 0;
2607 return ppp;
2608
2609 out2:
2610 mutex_unlock(&pn->all_ppp_mutex);
2611 free_netdev(dev);
2612 out1:
2613 *retp = ret;
2614 return NULL;
2615 }
2616
2617 /*
2618 * Initialize a ppp_file structure.
2619 */
2620 static void
2621 init_ppp_file(struct ppp_file *pf, int kind)
2622 {
2623 pf->kind = kind;
2624 skb_queue_head_init(&pf->xq);
2625 skb_queue_head_init(&pf->rq);
2626 atomic_set(&pf->refcnt, 1);
2627 init_waitqueue_head(&pf->rwait);
2628 }
2629
2630 /*
2631 * Take down a ppp interface unit - called when the owning file
2632 * (the one that created the unit) is closed or detached.
2633 */
2634 static void ppp_shutdown_interface(struct ppp *ppp)
2635 {
2636 struct ppp_net *pn;
2637
2638 pn = ppp_pernet(ppp->ppp_net);
2639 mutex_lock(&pn->all_ppp_mutex);
2640
2641 /* This will call dev_close() for us. */
2642 ppp_lock(ppp);
2643 if (!ppp->closing) {
2644 ppp->closing = 1;
2645 ppp_unlock(ppp);
2646 unregister_netdev(ppp->dev);
2647 } else
2648 ppp_unlock(ppp);
2649
2650 unit_put(&pn->units_idr, ppp->file.index);
2651 ppp->file.dead = 1;
2652 ppp->owner = NULL;
2653 wake_up_interruptible(&ppp->file.rwait);
2654
2655 mutex_unlock(&pn->all_ppp_mutex);
2656 }
2657
2658 /*
2659 * Free the memory used by a ppp unit. This is only called once
2660 * there are no channels connected to the unit and no file structs
2661 * that reference the unit.
2662 */
2663 static void ppp_destroy_interface(struct ppp *ppp)
2664 {
2665 atomic_dec(&ppp_unit_count);
2666
2667 if (!ppp->file.dead || ppp->n_channels) {
2668 /* "can't happen" */
2669 printk(KERN_ERR "ppp: destroying ppp struct %p but dead=%d "
2670 "n_channels=%d !\n", ppp, ppp->file.dead,
2671 ppp->n_channels);
2672 return;
2673 }
2674
2675 ppp_ccp_closed(ppp);
2676 if (ppp->vj) {
2677 slhc_free(ppp->vj);
2678 ppp->vj = NULL;
2679 }
2680 skb_queue_purge(&ppp->file.xq);
2681 skb_queue_purge(&ppp->file.rq);
2682 #ifdef CONFIG_PPP_MULTILINK
2683 skb_queue_purge(&ppp->mrq);
2684 #endif /* CONFIG_PPP_MULTILINK */
2685 #ifdef CONFIG_PPP_FILTER
2686 kfree(ppp->pass_filter);
2687 ppp->pass_filter = NULL;
2688 kfree(ppp->active_filter);
2689 ppp->active_filter = NULL;
2690 #endif /* CONFIG_PPP_FILTER */
2691
2692 kfree_skb(ppp->xmit_pending);
2693
2694 free_netdev(ppp->dev);
2695 }
2696
2697 /*
2698 * Locate an existing ppp unit.
2699 * The caller should have locked the all_ppp_mutex.
2700 */
2701 static struct ppp *
2702 ppp_find_unit(struct ppp_net *pn, int unit)
2703 {
2704 return unit_find(&pn->units_idr, unit);
2705 }
2706
2707 /*
2708 * Locate an existing ppp channel.
2709 * The caller should have locked the all_channels_lock.
2710 * First we look in the new_channels list, then in the
2711 * all_channels list. If found in the new_channels list,
2712 * we move it to the all_channels list. This is for speed
2713 * when we have a lot of channels in use.
2714 */
2715 static struct channel *
2716 ppp_find_channel(struct ppp_net *pn, int unit)
2717 {
2718 struct channel *pch;
2719
2720 list_for_each_entry(pch, &pn->new_channels, list) {
2721 if (pch->file.index == unit) {
2722 list_move(&pch->list, &pn->all_channels);
2723 return pch;
2724 }
2725 }
2726
2727 list_for_each_entry(pch, &pn->all_channels, list) {
2728 if (pch->file.index == unit)
2729 return pch;
2730 }
2731
2732 return NULL;
2733 }
2734
2735 /*
2736 * Connect a PPP channel to a PPP interface unit.
2737 */
2738 static int
2739 ppp_connect_channel(struct channel *pch, int unit)
2740 {
2741 struct ppp *ppp;
2742 struct ppp_net *pn;
2743 int ret = -ENXIO;
2744 int hdrlen;
2745
2746 pn = ppp_pernet(pch->chan_net);
2747
2748 mutex_lock(&pn->all_ppp_mutex);
2749 ppp = ppp_find_unit(pn, unit);
2750 if (!ppp)
2751 goto out;
2752 write_lock_bh(&pch->upl);
2753 ret = -EINVAL;
2754 if (pch->ppp)
2755 goto outl;
2756
2757 ppp_lock(ppp);
2758 if (pch->file.hdrlen > ppp->file.hdrlen)
2759 ppp->file.hdrlen = pch->file.hdrlen;
2760 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2761 if (hdrlen > ppp->dev->hard_header_len)
2762 ppp->dev->hard_header_len = hdrlen;
2763 list_add_tail(&pch->clist, &ppp->channels);
2764 ++ppp->n_channels;
2765 pch->ppp = ppp;
2766 atomic_inc(&ppp->file.refcnt);
2767 ppp_unlock(ppp);
2768 ret = 0;
2769
2770 outl:
2771 write_unlock_bh(&pch->upl);
2772 out:
2773 mutex_unlock(&pn->all_ppp_mutex);
2774 return ret;
2775 }
2776
2777 /*
2778 * Disconnect a channel from its ppp unit.
2779 */
2780 static int
2781 ppp_disconnect_channel(struct channel *pch)
2782 {
2783 struct ppp *ppp;
2784 int err = -EINVAL;
2785
2786 write_lock_bh(&pch->upl);
2787 ppp = pch->ppp;
2788 pch->ppp = NULL;
2789 write_unlock_bh(&pch->upl);
2790 if (ppp) {
2791 /* remove it from the ppp unit's list */
2792 ppp_lock(ppp);
2793 list_del(&pch->clist);
2794 if (--ppp->n_channels == 0)
2795 wake_up_interruptible(&ppp->file.rwait);
2796 ppp_unlock(ppp);
2797 if (atomic_dec_and_test(&ppp->file.refcnt))
2798 ppp_destroy_interface(ppp);
2799 err = 0;
2800 }
2801 return err;
2802 }
2803
2804 /*
2805 * Free up the resources used by a ppp channel.
2806 */
2807 static void ppp_destroy_channel(struct channel *pch)
2808 {
2809 atomic_dec(&channel_count);
2810
2811 if (!pch->file.dead) {
2812 /* "can't happen" */
2813 printk(KERN_ERR "ppp: destroying undead channel %p !\n",
2814 pch);
2815 return;
2816 }
2817 skb_queue_purge(&pch->file.xq);
2818 skb_queue_purge(&pch->file.rq);
2819 kfree(pch);
2820 }
2821
2822 static void __exit ppp_cleanup(void)
2823 {
2824 /* should never happen */
2825 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2826 printk(KERN_ERR "PPP: removing module but units remain!\n");
2827 unregister_chrdev(PPP_MAJOR, "ppp");
2828 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
2829 class_destroy(ppp_class);
2830 unregister_pernet_gen_device(ppp_net_id, &ppp_net_ops);
2831 }
2832
2833 /*
2834 * Units handling. Caller must protect concurrent access
2835 * by holding all_ppp_mutex
2836 */
2837
2838 /* associate pointer with specified number */
2839 static int unit_set(struct idr *p, void *ptr, int n)
2840 {
2841 int unit, err;
2842
2843 again:
2844 if (!idr_pre_get(p, GFP_KERNEL)) {
2845 printk(KERN_ERR "PPP: No free memory for idr\n");
2846 return -ENOMEM;
2847 }
2848
2849 err = idr_get_new_above(p, ptr, n, &unit);
2850 if (err == -EAGAIN)
2851 goto again;
2852
2853 if (unit != n) {
2854 idr_remove(p, unit);
2855 return -EINVAL;
2856 }
2857
2858 return unit;
2859 }
2860
2861 /* get new free unit number and associate pointer with it */
2862 static int unit_get(struct idr *p, void *ptr)
2863 {
2864 int unit, err;
2865
2866 again:
2867 if (!idr_pre_get(p, GFP_KERNEL)) {
2868 printk(KERN_ERR "PPP: No free memory for idr\n");
2869 return -ENOMEM;
2870 }
2871
2872 err = idr_get_new_above(p, ptr, 0, &unit);
2873 if (err == -EAGAIN)
2874 goto again;
2875
2876 return unit;
2877 }
2878
2879 /* put unit number back to a pool */
2880 static void unit_put(struct idr *p, int n)
2881 {
2882 idr_remove(p, n);
2883 }
2884
2885 /* get pointer associated with the number */
2886 static void *unit_find(struct idr *p, int n)
2887 {
2888 return idr_find(p, n);
2889 }
2890
2891 /* Module/initialization stuff */
2892
2893 module_init(ppp_init);
2894 module_exit(ppp_cleanup);
2895
2896 EXPORT_SYMBOL(ppp_register_net_channel);
2897 EXPORT_SYMBOL(ppp_register_channel);
2898 EXPORT_SYMBOL(ppp_unregister_channel);
2899 EXPORT_SYMBOL(ppp_channel_index);
2900 EXPORT_SYMBOL(ppp_unit_number);
2901 EXPORT_SYMBOL(ppp_input);
2902 EXPORT_SYMBOL(ppp_input_error);
2903 EXPORT_SYMBOL(ppp_output_wakeup);
2904 EXPORT_SYMBOL(ppp_register_compressor);
2905 EXPORT_SYMBOL(ppp_unregister_compressor);
2906 MODULE_LICENSE("GPL");
2907 MODULE_ALIAS_CHARDEV_MAJOR(PPP_MAJOR);
2908 MODULE_ALIAS("/dev/ppp");
Support for the Chinese Samsung S3C2440 based development boards