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Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
[linux-2.6/mini2440.git] / drivers / net / ppp_generic.c
blob8ee91421db12133634a922d2d8d70c933e22c248
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 }
1058
1059 /*
1060 * Transmit-side routines.
1061 */
1062
1063 /*
1064 * Called to do any work queued up on the transmit side
1065 * that can now be done.
1066 */
1067 static void
1068 ppp_xmit_process(struct ppp *ppp)
1069 {
1070 struct sk_buff *skb;
1071
1072 ppp_xmit_lock(ppp);
1073 if (!ppp->closing) {
1074 ppp_push(ppp);
1075 while (!ppp->xmit_pending
1076 && (skb = skb_dequeue(&ppp->file.xq)))
1077 ppp_send_frame(ppp, skb);
1078 /* If there's no work left to do, tell the core net
1079 code that we can accept some more. */
1080 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1081 netif_wake_queue(ppp->dev);
1082 }
1083 ppp_xmit_unlock(ppp);
1084 }
1085
1086 static inline struct sk_buff *
1087 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1088 {
1089 struct sk_buff *new_skb;
1090 int len;
1091 int new_skb_size = ppp->dev->mtu +
1092 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1093 int compressor_skb_size = ppp->dev->mtu +
1094 ppp->xcomp->comp_extra + PPP_HDRLEN;
1095 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1096 if (!new_skb) {
1097 if (net_ratelimit())
1098 printk(KERN_ERR "PPP: no memory (comp pkt)\n");
1099 return NULL;
1100 }
1101 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1102 skb_reserve(new_skb,
1103 ppp->dev->hard_header_len - PPP_HDRLEN);
1104
1105 /* compressor still expects A/C bytes in hdr */
1106 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1107 new_skb->data, skb->len + 2,
1108 compressor_skb_size);
1109 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1110 kfree_skb(skb);
1111 skb = new_skb;
1112 skb_put(skb, len);
1113 skb_pull(skb, 2); /* pull off A/C bytes */
1114 } else if (len == 0) {
1115 /* didn't compress, or CCP not up yet */
1116 kfree_skb(new_skb);
1117 new_skb = skb;
1118 } else {
1119 /*
1120 * (len < 0)
1121 * MPPE requires that we do not send unencrypted
1122 * frames. The compressor will return -1 if we
1123 * should drop the frame. We cannot simply test
1124 * the compress_proto because MPPE and MPPC share
1125 * the same number.
1126 */
1127 if (net_ratelimit())
1128 printk(KERN_ERR "ppp: compressor dropped pkt\n");
1129 kfree_skb(skb);
1130 kfree_skb(new_skb);
1131 new_skb = NULL;
1132 }
1133 return new_skb;
1134 }
1135
1136 /*
1137 * Compress and send a frame.
1138 * The caller should have locked the xmit path,
1139 * and xmit_pending should be 0.
1140 */
1141 static void
1142 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1143 {
1144 int proto = PPP_PROTO(skb);
1145 struct sk_buff *new_skb;
1146 int len;
1147 unsigned char *cp;
1148
1149 if (proto < 0x8000) {
1150 #ifdef CONFIG_PPP_FILTER
1151 /* check if we should pass this packet */
1152 /* the filter instructions are constructed assuming
1153 a four-byte PPP header on each packet */
1154 *skb_push(skb, 2) = 1;
1155 if (ppp->pass_filter
1156 && sk_run_filter(skb, ppp->pass_filter,
1157 ppp->pass_len) == 0) {
1158 if (ppp->debug & 1)
1159 printk(KERN_DEBUG "PPP: outbound frame not passed\n");
1160 kfree_skb(skb);
1161 return;
1162 }
1163 /* if this packet passes the active filter, record the time */
1164 if (!(ppp->active_filter
1165 && sk_run_filter(skb, ppp->active_filter,
1166 ppp->active_len) == 0))
1167 ppp->last_xmit = jiffies;
1168 skb_pull(skb, 2);
1169 #else
1170 /* for data packets, record the time */
1171 ppp->last_xmit = jiffies;
1172 #endif /* CONFIG_PPP_FILTER */
1173 }
1174
1175 ++ppp->dev->stats.tx_packets;
1176 ppp->dev->stats.tx_bytes += skb->len - 2;
1177
1178 switch (proto) {
1179 case PPP_IP:
1180 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1181 break;
1182 /* try to do VJ TCP header compression */
1183 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1184 GFP_ATOMIC);
1185 if (!new_skb) {
1186 printk(KERN_ERR "PPP: no memory (VJ comp pkt)\n");
1187 goto drop;
1188 }
1189 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1190 cp = skb->data + 2;
1191 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1192 new_skb->data + 2, &cp,
1193 !(ppp->flags & SC_NO_TCP_CCID));
1194 if (cp == skb->data + 2) {
1195 /* didn't compress */
1196 kfree_skb(new_skb);
1197 } else {
1198 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1199 proto = PPP_VJC_COMP;
1200 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1201 } else {
1202 proto = PPP_VJC_UNCOMP;
1203 cp[0] = skb->data[2];
1204 }
1205 kfree_skb(skb);
1206 skb = new_skb;
1207 cp = skb_put(skb, len + 2);
1208 cp[0] = 0;
1209 cp[1] = proto;
1210 }
1211 break;
1212
1213 case PPP_CCP:
1214 /* peek at outbound CCP frames */
1215 ppp_ccp_peek(ppp, skb, 0);
1216 break;
1217 }
1218
1219 /* try to do packet compression */
1220 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state
1221 && proto != PPP_LCP && proto != PPP_CCP) {
1222 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1223 if (net_ratelimit())
1224 printk(KERN_ERR "ppp: compression required but down - pkt dropped.\n");
1225 goto drop;
1226 }
1227 skb = pad_compress_skb(ppp, skb);
1228 if (!skb)
1229 goto drop;
1230 }
1231
1232 /*
1233 * If we are waiting for traffic (demand dialling),
1234 * queue it up for pppd to receive.
1235 */
1236 if (ppp->flags & SC_LOOP_TRAFFIC) {
1237 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1238 goto drop;
1239 skb_queue_tail(&ppp->file.rq, skb);
1240 wake_up_interruptible(&ppp->file.rwait);
1241 return;
1242 }
1243
1244 ppp->xmit_pending = skb;
1245 ppp_push(ppp);
1246 return;
1247
1248 drop:
1249 kfree_skb(skb);
1250 ++ppp->dev->stats.tx_errors;
1251 }
1252
1253 /*
1254 * Try to send the frame in xmit_pending.
1255 * The caller should have the xmit path locked.
1256 */
1257 static void
1258 ppp_push(struct ppp *ppp)
1259 {
1260 struct list_head *list;
1261 struct channel *pch;
1262 struct sk_buff *skb = ppp->xmit_pending;
1263
1264 if (!skb)
1265 return;
1266
1267 list = &ppp->channels;
1268 if (list_empty(list)) {
1269 /* nowhere to send the packet, just drop it */
1270 ppp->xmit_pending = NULL;
1271 kfree_skb(skb);
1272 return;
1273 }
1274
1275 if ((ppp->flags & SC_MULTILINK) == 0) {
1276 /* not doing multilink: send it down the first channel */
1277 list = list->next;
1278 pch = list_entry(list, struct channel, clist);
1279
1280 spin_lock_bh(&pch->downl);
1281 if (pch->chan) {
1282 if (pch->chan->ops->start_xmit(pch->chan, skb))
1283 ppp->xmit_pending = NULL;
1284 } else {
1285 /* channel got unregistered */
1286 kfree_skb(skb);
1287 ppp->xmit_pending = NULL;
1288 }
1289 spin_unlock_bh(&pch->downl);
1290 return;
1291 }
1292
1293 #ifdef CONFIG_PPP_MULTILINK
1294 /* Multilink: fragment the packet over as many links
1295 as can take the packet at the moment. */
1296 if (!ppp_mp_explode(ppp, skb))
1297 return;
1298 #endif /* CONFIG_PPP_MULTILINK */
1299
1300 ppp->xmit_pending = NULL;
1301 kfree_skb(skb);
1302 }
1303
1304 #ifdef CONFIG_PPP_MULTILINK
1305 /*
1306 * Divide a packet to be transmitted into fragments and
1307 * send them out the individual links.
1308 */
1309 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1310 {
1311 int len, totlen;
1312 int i, bits, hdrlen, mtu;
1313 int flen;
1314 int navail, nfree, nzero;
1315 int nbigger;
1316 int totspeed;
1317 int totfree;
1318 unsigned char *p, *q;
1319 struct list_head *list;
1320 struct channel *pch;
1321 struct sk_buff *frag;
1322 struct ppp_channel *chan;
1323
1324 totspeed = 0; /*total bitrate of the bundle*/
1325 nfree = 0; /* # channels which have no packet already queued */
1326 navail = 0; /* total # of usable channels (not deregistered) */
1327 nzero = 0; /* number of channels with zero speed associated*/
1328 totfree = 0; /*total # of channels available and
1329 *having no queued packets before
1330 *starting the fragmentation*/
1331
1332 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1333 i = 0;
1334 list_for_each_entry(pch, &ppp->channels, clist) {
1335 navail += pch->avail = (pch->chan != NULL);
1336 pch->speed = pch->chan->speed;
1337 if (pch->avail) {
1338 if (skb_queue_empty(&pch->file.xq) ||
1339 !pch->had_frag) {
1340 if (pch->speed == 0)
1341 nzero++;
1342 else
1343 totspeed += pch->speed;
1344
1345 pch->avail = 2;
1346 ++nfree;
1347 ++totfree;
1348 }
1349 if (!pch->had_frag && i < ppp->nxchan)
1350 ppp->nxchan = i;
1351 }
1352 ++i;
1353 }
1354 /*
1355 * Don't start sending this packet unless at least half of
1356 * the channels are free. This gives much better TCP
1357 * performance if we have a lot of channels.
1358 */
1359 if (nfree == 0 || nfree < navail / 2)
1360 return 0; /* can't take now, leave it in xmit_pending */
1361
1362 /* Do protocol field compression (XXX this should be optional) */
1363 p = skb->data;
1364 len = skb->len;
1365 if (*p == 0) {
1366 ++p;
1367 --len;
1368 }
1369
1370 totlen = len;
1371 nbigger = len % nfree;
1372
1373 /* skip to the channel after the one we last used
1374 and start at that one */
1375 list = &ppp->channels;
1376 for (i = 0; i < ppp->nxchan; ++i) {
1377 list = list->next;
1378 if (list == &ppp->channels) {
1379 i = 0;
1380 break;
1381 }
1382 }
1383
1384 /* create a fragment for each channel */
1385 bits = B;
1386 while (nfree > 0 && len > 0) {
1387 list = list->next;
1388 if (list == &ppp->channels) {
1389 i = 0;
1390 continue;
1391 }
1392 pch = list_entry(list, struct channel, clist);
1393 ++i;
1394 if (!pch->avail)
1395 continue;
1396
1397 /*
1398 * Skip this channel if it has a fragment pending already and
1399 * we haven't given a fragment to all of the free channels.
1400 */
1401 if (pch->avail == 1) {
1402 if (nfree > 0)
1403 continue;
1404 } else {
1405 pch->avail = 1;
1406 }
1407
1408 /* check the channel's mtu and whether it is still attached. */
1409 spin_lock_bh(&pch->downl);
1410 if (pch->chan == NULL) {
1411 /* can't use this channel, it's being deregistered */
1412 if (pch->speed == 0)
1413 nzero--;
1414 else
1415 totspeed -= pch->speed;
1416
1417 spin_unlock_bh(&pch->downl);
1418 pch->avail = 0;
1419 totlen = len;
1420 totfree--;
1421 nfree--;
1422 if (--navail == 0)
1423 break;
1424 continue;
1425 }
1426
1427 /*
1428 *if the channel speed is not set divide
1429 *the packet evenly among the free channels;
1430 *otherwise divide it according to the speed
1431 *of the channel we are going to transmit on
1432 */
1433 if (pch->speed == 0) {
1434 flen = totlen/nfree ;
1435 if (nbigger > 0) {
1436 flen++;
1437 nbigger--;
1438 }
1439 } else {
1440 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
1441 ((totspeed*totfree)/pch->speed)) - hdrlen;
1442 if (nbigger > 0) {
1443 flen += ((totfree - nzero)*pch->speed)/totspeed;
1444 nbigger -= ((totfree - nzero)*pch->speed)/
1445 totspeed;
1446 }
1447 }
1448 nfree--;
1449
1450 /*
1451 *check if we are on the last channel or
1452 *we exceded the lenght of the data to
1453 *fragment
1454 */
1455 if ((nfree == 0) || (flen > len))
1456 flen = len;
1457 /*
1458 *it is not worth to tx on slow channels:
1459 *in that case from the resulting flen according to the
1460 *above formula will be equal or less than zero.
1461 *Skip the channel in this case
1462 */
1463 if (flen <= 0) {
1464 pch->avail = 2;
1465 spin_unlock_bh(&pch->downl);
1466 continue;
1467 }
1468
1469 mtu = pch->chan->mtu + 2 - hdrlen;
1470 if (mtu < 4)
1471 mtu = 4;
1472 if (flen > mtu)
1473 flen = mtu;
1474 if (flen == len)
1475 bits |= E;
1476 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1477 if (!frag)
1478 goto noskb;
1479 q = skb_put(frag, flen + hdrlen);
1480
1481 /* make the MP header */
1482 q[0] = PPP_MP >> 8;
1483 q[1] = PPP_MP;
1484 if (ppp->flags & SC_MP_XSHORTSEQ) {
1485 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1486 q[3] = ppp->nxseq;
1487 } else {
1488 q[2] = bits;
1489 q[3] = ppp->nxseq >> 16;
1490 q[4] = ppp->nxseq >> 8;
1491 q[5] = ppp->nxseq;
1492 }
1493
1494 memcpy(q + hdrlen, p, flen);
1495
1496 /* try to send it down the channel */
1497 chan = pch->chan;
1498 if (!skb_queue_empty(&pch->file.xq) ||
1499 !chan->ops->start_xmit(chan, frag))
1500 skb_queue_tail(&pch->file.xq, frag);
1501 pch->had_frag = 1;
1502 p += flen;
1503 len -= flen;
1504 ++ppp->nxseq;
1505 bits = 0;
1506 spin_unlock_bh(&pch->downl);
1507 }
1508 ppp->nxchan = i;
1509
1510 return 1;
1511
1512 noskb:
1513 spin_unlock_bh(&pch->downl);
1514 if (ppp->debug & 1)
1515 printk(KERN_ERR "PPP: no memory (fragment)\n");
1516 ++ppp->dev->stats.tx_errors;
1517 ++ppp->nxseq;
1518 return 1; /* abandon the frame */
1519 }
1520 #endif /* CONFIG_PPP_MULTILINK */
1521
1522 /*
1523 * Try to send data out on a channel.
1524 */
1525 static void
1526 ppp_channel_push(struct channel *pch)
1527 {
1528 struct sk_buff *skb;
1529 struct ppp *ppp;
1530
1531 spin_lock_bh(&pch->downl);
1532 if (pch->chan) {
1533 while (!skb_queue_empty(&pch->file.xq)) {
1534 skb = skb_dequeue(&pch->file.xq);
1535 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1536 /* put the packet back and try again later */
1537 skb_queue_head(&pch->file.xq, skb);
1538 break;
1539 }
1540 }
1541 } else {
1542 /* channel got deregistered */
1543 skb_queue_purge(&pch->file.xq);
1544 }
1545 spin_unlock_bh(&pch->downl);
1546 /* see if there is anything from the attached unit to be sent */
1547 if (skb_queue_empty(&pch->file.xq)) {
1548 read_lock_bh(&pch->upl);
1549 ppp = pch->ppp;
1550 if (ppp)
1551 ppp_xmit_process(ppp);
1552 read_unlock_bh(&pch->upl);
1553 }
1554 }
1555
1556 /*
1557 * Receive-side routines.
1558 */
1559
1560 /* misuse a few fields of the skb for MP reconstruction */
1561 #define sequence priority
1562 #define BEbits cb[0]
1563
1564 static inline void
1565 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1566 {
1567 ppp_recv_lock(ppp);
1568 if (!ppp->closing)
1569 ppp_receive_frame(ppp, skb, pch);
1570 else
1571 kfree_skb(skb);
1572 ppp_recv_unlock(ppp);
1573 }
1574
1575 void
1576 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1577 {
1578 struct channel *pch = chan->ppp;
1579 int proto;
1580
1581 if (!pch || skb->len == 0) {
1582 kfree_skb(skb);
1583 return;
1584 }
1585
1586 proto = PPP_PROTO(skb);
1587 read_lock_bh(&pch->upl);
1588 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1589 /* put it on the channel queue */
1590 skb_queue_tail(&pch->file.rq, skb);
1591 /* drop old frames if queue too long */
1592 while (pch->file.rq.qlen > PPP_MAX_RQLEN
1593 && (skb = skb_dequeue(&pch->file.rq)))
1594 kfree_skb(skb);
1595 wake_up_interruptible(&pch->file.rwait);
1596 } else {
1597 ppp_do_recv(pch->ppp, skb, pch);
1598 }
1599 read_unlock_bh(&pch->upl);
1600 }
1601
1602 /* Put a 0-length skb in the receive queue as an error indication */
1603 void
1604 ppp_input_error(struct ppp_channel *chan, int code)
1605 {
1606 struct channel *pch = chan->ppp;
1607 struct sk_buff *skb;
1608
1609 if (!pch)
1610 return;
1611
1612 read_lock_bh(&pch->upl);
1613 if (pch->ppp) {
1614 skb = alloc_skb(0, GFP_ATOMIC);
1615 if (skb) {
1616 skb->len = 0; /* probably unnecessary */
1617 skb->cb[0] = code;
1618 ppp_do_recv(pch->ppp, skb, pch);
1619 }
1620 }
1621 read_unlock_bh(&pch->upl);
1622 }
1623
1624 /*
1625 * We come in here to process a received frame.
1626 * The receive side of the ppp unit is locked.
1627 */
1628 static void
1629 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1630 {
1631 if (pskb_may_pull(skb, 2)) {
1632 #ifdef CONFIG_PPP_MULTILINK
1633 /* XXX do channel-level decompression here */
1634 if (PPP_PROTO(skb) == PPP_MP)
1635 ppp_receive_mp_frame(ppp, skb, pch);
1636 else
1637 #endif /* CONFIG_PPP_MULTILINK */
1638 ppp_receive_nonmp_frame(ppp, skb);
1639 return;
1640 }
1641
1642 if (skb->len > 0)
1643 /* note: a 0-length skb is used as an error indication */
1644 ++ppp->dev->stats.rx_length_errors;
1645
1646 kfree_skb(skb);
1647 ppp_receive_error(ppp);
1648 }
1649
1650 static void
1651 ppp_receive_error(struct ppp *ppp)
1652 {
1653 ++ppp->dev->stats.rx_errors;
1654 if (ppp->vj)
1655 slhc_toss(ppp->vj);
1656 }
1657
1658 static void
1659 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1660 {
1661 struct sk_buff *ns;
1662 int proto, len, npi;
1663
1664 /*
1665 * Decompress the frame, if compressed.
1666 * Note that some decompressors need to see uncompressed frames
1667 * that come in as well as compressed frames.
1668 */
1669 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)
1670 && (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1671 skb = ppp_decompress_frame(ppp, skb);
1672
1673 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1674 goto err;
1675
1676 proto = PPP_PROTO(skb);
1677 switch (proto) {
1678 case PPP_VJC_COMP:
1679 /* decompress VJ compressed packets */
1680 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1681 goto err;
1682
1683 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1684 /* copy to a new sk_buff with more tailroom */
1685 ns = dev_alloc_skb(skb->len + 128);
1686 if (!ns) {
1687 printk(KERN_ERR"PPP: no memory (VJ decomp)\n");
1688 goto err;
1689 }
1690 skb_reserve(ns, 2);
1691 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1692 kfree_skb(skb);
1693 skb = ns;
1694 }
1695 else
1696 skb->ip_summed = CHECKSUM_NONE;
1697
1698 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1699 if (len <= 0) {
1700 printk(KERN_DEBUG "PPP: VJ decompression error\n");
1701 goto err;
1702 }
1703 len += 2;
1704 if (len > skb->len)
1705 skb_put(skb, len - skb->len);
1706 else if (len < skb->len)
1707 skb_trim(skb, len);
1708 proto = PPP_IP;
1709 break;
1710
1711 case PPP_VJC_UNCOMP:
1712 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1713 goto err;
1714
1715 /* Until we fix the decompressor need to make sure
1716 * data portion is linear.
1717 */
1718 if (!pskb_may_pull(skb, skb->len))
1719 goto err;
1720
1721 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1722 printk(KERN_ERR "PPP: VJ uncompressed error\n");
1723 goto err;
1724 }
1725 proto = PPP_IP;
1726 break;
1727
1728 case PPP_CCP:
1729 ppp_ccp_peek(ppp, skb, 1);
1730 break;
1731 }
1732
1733 ++ppp->dev->stats.rx_packets;
1734 ppp->dev->stats.rx_bytes += skb->len - 2;
1735
1736 npi = proto_to_npindex(proto);
1737 if (npi < 0) {
1738 /* control or unknown frame - pass it to pppd */
1739 skb_queue_tail(&ppp->file.rq, skb);
1740 /* limit queue length by dropping old frames */
1741 while (ppp->file.rq.qlen > PPP_MAX_RQLEN
1742 && (skb = skb_dequeue(&ppp->file.rq)))
1743 kfree_skb(skb);
1744 /* wake up any process polling or blocking on read */
1745 wake_up_interruptible(&ppp->file.rwait);
1746
1747 } else {
1748 /* network protocol frame - give it to the kernel */
1749
1750 #ifdef CONFIG_PPP_FILTER
1751 /* check if the packet passes the pass and active filters */
1752 /* the filter instructions are constructed assuming
1753 a four-byte PPP header on each packet */
1754 if (ppp->pass_filter || ppp->active_filter) {
1755 if (skb_cloned(skb) &&
1756 pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
1757 goto err;
1758
1759 *skb_push(skb, 2) = 0;
1760 if (ppp->pass_filter
1761 && sk_run_filter(skb, ppp->pass_filter,
1762 ppp->pass_len) == 0) {
1763 if (ppp->debug & 1)
1764 printk(KERN_DEBUG "PPP: inbound frame "
1765 "not passed\n");
1766 kfree_skb(skb);
1767 return;
1768 }
1769 if (!(ppp->active_filter
1770 && sk_run_filter(skb, ppp->active_filter,
1771 ppp->active_len) == 0))
1772 ppp->last_recv = jiffies;
1773 __skb_pull(skb, 2);
1774 } else
1775 #endif /* CONFIG_PPP_FILTER */
1776 ppp->last_recv = jiffies;
1777
1778 if ((ppp->dev->flags & IFF_UP) == 0
1779 || ppp->npmode[npi] != NPMODE_PASS) {
1780 kfree_skb(skb);
1781 } else {
1782 /* chop off protocol */
1783 skb_pull_rcsum(skb, 2);
1784 skb->dev = ppp->dev;
1785 skb->protocol = htons(npindex_to_ethertype[npi]);
1786 skb_reset_mac_header(skb);
1787 netif_rx(skb);
1788 }
1789 }
1790 return;
1791
1792 err:
1793 kfree_skb(skb);
1794 ppp_receive_error(ppp);
1795 }
1796
1797 static struct sk_buff *
1798 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1799 {
1800 int proto = PPP_PROTO(skb);
1801 struct sk_buff *ns;
1802 int len;
1803
1804 /* Until we fix all the decompressor's need to make sure
1805 * data portion is linear.
1806 */
1807 if (!pskb_may_pull(skb, skb->len))
1808 goto err;
1809
1810 if (proto == PPP_COMP) {
1811 int obuff_size;
1812
1813 switch(ppp->rcomp->compress_proto) {
1814 case CI_MPPE:
1815 obuff_size = ppp->mru + PPP_HDRLEN + 1;
1816 break;
1817 default:
1818 obuff_size = ppp->mru + PPP_HDRLEN;
1819 break;
1820 }
1821
1822 ns = dev_alloc_skb(obuff_size);
1823 if (!ns) {
1824 printk(KERN_ERR "ppp_decompress_frame: no memory\n");
1825 goto err;
1826 }
1827 /* the decompressor still expects the A/C bytes in the hdr */
1828 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1829 skb->len + 2, ns->data, obuff_size);
1830 if (len < 0) {
1831 /* Pass the compressed frame to pppd as an
1832 error indication. */
1833 if (len == DECOMP_FATALERROR)
1834 ppp->rstate |= SC_DC_FERROR;
1835 kfree_skb(ns);
1836 goto err;
1837 }
1838
1839 kfree_skb(skb);
1840 skb = ns;
1841 skb_put(skb, len);
1842 skb_pull(skb, 2); /* pull off the A/C bytes */
1843
1844 } else {
1845 /* Uncompressed frame - pass to decompressor so it
1846 can update its dictionary if necessary. */
1847 if (ppp->rcomp->incomp)
1848 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1849 skb->len + 2);
1850 }
1851
1852 return skb;
1853
1854 err:
1855 ppp->rstate |= SC_DC_ERROR;
1856 ppp_receive_error(ppp);
1857 return skb;
1858 }
1859
1860 #ifdef CONFIG_PPP_MULTILINK
1861 /*
1862 * Receive a multilink frame.
1863 * We put it on the reconstruction queue and then pull off
1864 * as many completed frames as we can.
1865 */
1866 static void
1867 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1868 {
1869 u32 mask, seq;
1870 struct channel *ch;
1871 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1872
1873 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
1874 goto err; /* no good, throw it away */
1875
1876 /* Decode sequence number and begin/end bits */
1877 if (ppp->flags & SC_MP_SHORTSEQ) {
1878 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1879 mask = 0xfff;
1880 } else {
1881 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1882 mask = 0xffffff;
1883 }
1884 skb->BEbits = skb->data[2];
1885 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
1886
1887 /*
1888 * Do protocol ID decompression on the first fragment of each packet.
1889 */
1890 if ((skb->BEbits & B) && (skb->data[0] & 1))
1891 *skb_push(skb, 1) = 0;
1892
1893 /*
1894 * Expand sequence number to 32 bits, making it as close
1895 * as possible to ppp->minseq.
1896 */
1897 seq |= ppp->minseq & ~mask;
1898 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
1899 seq += mask + 1;
1900 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
1901 seq -= mask + 1; /* should never happen */
1902 skb->sequence = seq;
1903 pch->lastseq = seq;
1904
1905 /*
1906 * If this packet comes before the next one we were expecting,
1907 * drop it.
1908 */
1909 if (seq_before(seq, ppp->nextseq)) {
1910 kfree_skb(skb);
1911 ++ppp->dev->stats.rx_dropped;
1912 ppp_receive_error(ppp);
1913 return;
1914 }
1915
1916 /*
1917 * Reevaluate minseq, the minimum over all channels of the
1918 * last sequence number received on each channel. Because of
1919 * the increasing sequence number rule, we know that any fragment
1920 * before `minseq' which hasn't arrived is never going to arrive.
1921 * The list of channels can't change because we have the receive
1922 * side of the ppp unit locked.
1923 */
1924 list_for_each_entry(ch, &ppp->channels, clist) {
1925 if (seq_before(ch->lastseq, seq))
1926 seq = ch->lastseq;
1927 }
1928 if (seq_before(ppp->minseq, seq))
1929 ppp->minseq = seq;
1930
1931 /* Put the fragment on the reconstruction queue */
1932 ppp_mp_insert(ppp, skb);
1933
1934 /* If the queue is getting long, don't wait any longer for packets
1935 before the start of the queue. */
1936 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
1937 struct sk_buff *skb = skb_peek(&ppp->mrq);
1938 if (seq_before(ppp->minseq, skb->sequence))
1939 ppp->minseq = skb->sequence;
1940 }
1941
1942 /* Pull completed packets off the queue and receive them. */
1943 while ((skb = ppp_mp_reconstruct(ppp)))
1944 ppp_receive_nonmp_frame(ppp, skb);
1945
1946 return;
1947
1948 err:
1949 kfree_skb(skb);
1950 ppp_receive_error(ppp);
1951 }
1952
1953 /*
1954 * Insert a fragment on the MP reconstruction queue.
1955 * The queue is ordered by increasing sequence number.
1956 */
1957 static void
1958 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
1959 {
1960 struct sk_buff *p;
1961 struct sk_buff_head *list = &ppp->mrq;
1962 u32 seq = skb->sequence;
1963
1964 /* N.B. we don't need to lock the list lock because we have the
1965 ppp unit receive-side lock. */
1966 skb_queue_walk(list, p) {
1967 if (seq_before(seq, p->sequence))
1968 break;
1969 }
1970 __skb_queue_before(list, p, skb);
1971 }
1972
1973 /*
1974 * Reconstruct a packet from the MP fragment queue.
1975 * We go through increasing sequence numbers until we find a
1976 * complete packet, or we get to the sequence number for a fragment
1977 * which hasn't arrived but might still do so.
1978 */
1979 static struct sk_buff *
1980 ppp_mp_reconstruct(struct ppp *ppp)
1981 {
1982 u32 seq = ppp->nextseq;
1983 u32 minseq = ppp->minseq;
1984 struct sk_buff_head *list = &ppp->mrq;
1985 struct sk_buff *p, *next;
1986 struct sk_buff *head, *tail;
1987 struct sk_buff *skb = NULL;
1988 int lost = 0, len = 0;
1989
1990 if (ppp->mrru == 0) /* do nothing until mrru is set */
1991 return NULL;
1992 head = list->next;
1993 tail = NULL;
1994 for (p = head; p != (struct sk_buff *) list; p = next) {
1995 next = p->next;
1996 if (seq_before(p->sequence, seq)) {
1997 /* this can't happen, anyway ignore the skb */
1998 printk(KERN_ERR "ppp_mp_reconstruct bad seq %u < %u\n",
1999 p->sequence, seq);
2000 head = next;
2001 continue;
2002 }
2003 if (p->sequence != seq) {
2004 /* Fragment `seq' is missing. If it is after
2005 minseq, it might arrive later, so stop here. */
2006 if (seq_after(seq, minseq))
2007 break;
2008 /* Fragment `seq' is lost, keep going. */
2009 lost = 1;
2010 seq = seq_before(minseq, p->sequence)?
2011 minseq + 1: p->sequence;
2012 next = p;
2013 continue;
2014 }
2015
2016 /*
2017 * At this point we know that all the fragments from
2018 * ppp->nextseq to seq are either present or lost.
2019 * Also, there are no complete packets in the queue
2020 * that have no missing fragments and end before this
2021 * fragment.
2022 */
2023
2024 /* B bit set indicates this fragment starts a packet */
2025 if (p->BEbits & B) {
2026 head = p;
2027 lost = 0;
2028 len = 0;
2029 }
2030
2031 len += p->len;
2032
2033 /* Got a complete packet yet? */
2034 if (lost == 0 && (p->BEbits & E) && (head->BEbits & B)) {
2035 if (len > ppp->mrru + 2) {
2036 ++ppp->dev->stats.rx_length_errors;
2037 printk(KERN_DEBUG "PPP: reconstructed packet"
2038 " is too long (%d)\n", len);
2039 } else if (p == head) {
2040 /* fragment is complete packet - reuse skb */
2041 tail = p;
2042 skb = skb_get(p);
2043 break;
2044 } else if ((skb = dev_alloc_skb(len)) == NULL) {
2045 ++ppp->dev->stats.rx_missed_errors;
2046 printk(KERN_DEBUG "PPP: no memory for "
2047 "reconstructed packet");
2048 } else {
2049 tail = p;
2050 break;
2051 }
2052 ppp->nextseq = seq + 1;
2053 }
2054
2055 /*
2056 * If this is the ending fragment of a packet,
2057 * and we haven't found a complete valid packet yet,
2058 * we can discard up to and including this fragment.
2059 */
2060 if (p->BEbits & E)
2061 head = next;
2062
2063 ++seq;
2064 }
2065
2066 /* If we have a complete packet, copy it all into one skb. */
2067 if (tail != NULL) {
2068 /* If we have discarded any fragments,
2069 signal a receive error. */
2070 if (head->sequence != ppp->nextseq) {
2071 if (ppp->debug & 1)
2072 printk(KERN_DEBUG " missed pkts %u..%u\n",
2073 ppp->nextseq, head->sequence-1);
2074 ++ppp->dev->stats.rx_dropped;
2075 ppp_receive_error(ppp);
2076 }
2077
2078 if (head != tail)
2079 /* copy to a single skb */
2080 for (p = head; p != tail->next; p = p->next)
2081 skb_copy_bits(p, 0, skb_put(skb, p->len), p->len);
2082 ppp->nextseq = tail->sequence + 1;
2083 head = tail->next;
2084 }
2085
2086 /* Discard all the skbuffs that we have copied the data out of
2087 or that we can't use. */
2088 while ((p = list->next) != head) {
2089 __skb_unlink(p, list);
2090 kfree_skb(p);
2091 }
2092
2093 return skb;
2094 }
2095 #endif /* CONFIG_PPP_MULTILINK */
2096
2097 /*
2098 * Channel interface.
2099 */
2100
2101 /* Create a new, unattached ppp channel. */
2102 int ppp_register_channel(struct ppp_channel *chan)
2103 {
2104 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2105 }
2106
2107 /* Create a new, unattached ppp channel for specified net. */
2108 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
2109 {
2110 struct channel *pch;
2111 struct ppp_net *pn;
2112
2113 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2114 if (!pch)
2115 return -ENOMEM;
2116
2117 pn = ppp_pernet(net);
2118
2119 pch->ppp = NULL;
2120 pch->chan = chan;
2121 pch->chan_net = net;
2122 chan->ppp = pch;
2123 init_ppp_file(&pch->file, CHANNEL);
2124 pch->file.hdrlen = chan->hdrlen;
2125 #ifdef CONFIG_PPP_MULTILINK
2126 pch->lastseq = -1;
2127 #endif /* CONFIG_PPP_MULTILINK */
2128 init_rwsem(&pch->chan_sem);
2129 spin_lock_init(&pch->downl);
2130 rwlock_init(&pch->upl);
2131
2132 spin_lock_bh(&pn->all_channels_lock);
2133 pch->file.index = ++pn->last_channel_index;
2134 list_add(&pch->list, &pn->new_channels);
2135 atomic_inc(&channel_count);
2136 spin_unlock_bh(&pn->all_channels_lock);
2137
2138 return 0;
2139 }
2140
2141 /*
2142 * Return the index of a channel.
2143 */
2144 int ppp_channel_index(struct ppp_channel *chan)
2145 {
2146 struct channel *pch = chan->ppp;
2147
2148 if (pch)
2149 return pch->file.index;
2150 return -1;
2151 }
2152
2153 /*
2154 * Return the PPP unit number to which a channel is connected.
2155 */
2156 int ppp_unit_number(struct ppp_channel *chan)
2157 {
2158 struct channel *pch = chan->ppp;
2159 int unit = -1;
2160
2161 if (pch) {
2162 read_lock_bh(&pch->upl);
2163 if (pch->ppp)
2164 unit = pch->ppp->file.index;
2165 read_unlock_bh(&pch->upl);
2166 }
2167 return unit;
2168 }
2169
2170 /*
2171 * Disconnect a channel from the generic layer.
2172 * This must be called in process context.
2173 */
2174 void
2175 ppp_unregister_channel(struct ppp_channel *chan)
2176 {
2177 struct channel *pch = chan->ppp;
2178 struct ppp_net *pn;
2179
2180 if (!pch)
2181 return; /* should never happen */
2182
2183 chan->ppp = NULL;
2184
2185 /*
2186 * This ensures that we have returned from any calls into the
2187 * the channel's start_xmit or ioctl routine before we proceed.
2188 */
2189 down_write(&pch->chan_sem);
2190 spin_lock_bh(&pch->downl);
2191 pch->chan = NULL;
2192 spin_unlock_bh(&pch->downl);
2193 up_write(&pch->chan_sem);
2194 ppp_disconnect_channel(pch);
2195
2196 pn = ppp_pernet(pch->chan_net);
2197 spin_lock_bh(&pn->all_channels_lock);
2198 list_del(&pch->list);
2199 spin_unlock_bh(&pn->all_channels_lock);
2200
2201 pch->file.dead = 1;
2202 wake_up_interruptible(&pch->file.rwait);
2203 if (atomic_dec_and_test(&pch->file.refcnt))
2204 ppp_destroy_channel(pch);
2205 }
2206
2207 /*
2208 * Callback from a channel when it can accept more to transmit.
2209 * This should be called at BH/softirq level, not interrupt level.
2210 */
2211 void
2212 ppp_output_wakeup(struct ppp_channel *chan)
2213 {
2214 struct channel *pch = chan->ppp;
2215
2216 if (!pch)
2217 return;
2218 ppp_channel_push(pch);
2219 }
2220
2221 /*
2222 * Compression control.
2223 */
2224
2225 /* Process the PPPIOCSCOMPRESS ioctl. */
2226 static int
2227 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2228 {
2229 int err;
2230 struct compressor *cp, *ocomp;
2231 struct ppp_option_data data;
2232 void *state, *ostate;
2233 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2234
2235 err = -EFAULT;
2236 if (copy_from_user(&data, (void __user *) arg, sizeof(data))
2237 || (data.length <= CCP_MAX_OPTION_LENGTH
2238 && copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2239 goto out;
2240 err = -EINVAL;
2241 if (data.length > CCP_MAX_OPTION_LENGTH
2242 || ccp_option[1] < 2 || ccp_option[1] > data.length)
2243 goto out;
2244
2245 cp = try_then_request_module(
2246 find_compressor(ccp_option[0]),
2247 "ppp-compress-%d", ccp_option[0]);
2248 if (!cp)
2249 goto out;
2250
2251 err = -ENOBUFS;
2252 if (data.transmit) {
2253 state = cp->comp_alloc(ccp_option, data.length);
2254 if (state) {
2255 ppp_xmit_lock(ppp);
2256 ppp->xstate &= ~SC_COMP_RUN;
2257 ocomp = ppp->xcomp;
2258 ostate = ppp->xc_state;
2259 ppp->xcomp = cp;
2260 ppp->xc_state = state;
2261 ppp_xmit_unlock(ppp);
2262 if (ostate) {
2263 ocomp->comp_free(ostate);
2264 module_put(ocomp->owner);
2265 }
2266 err = 0;
2267 } else
2268 module_put(cp->owner);
2269
2270 } else {
2271 state = cp->decomp_alloc(ccp_option, data.length);
2272 if (state) {
2273 ppp_recv_lock(ppp);
2274 ppp->rstate &= ~SC_DECOMP_RUN;
2275 ocomp = ppp->rcomp;
2276 ostate = ppp->rc_state;
2277 ppp->rcomp = cp;
2278 ppp->rc_state = state;
2279 ppp_recv_unlock(ppp);
2280 if (ostate) {
2281 ocomp->decomp_free(ostate);
2282 module_put(ocomp->owner);
2283 }
2284 err = 0;
2285 } else
2286 module_put(cp->owner);
2287 }
2288
2289 out:
2290 return err;
2291 }
2292
2293 /*
2294 * Look at a CCP packet and update our state accordingly.
2295 * We assume the caller has the xmit or recv path locked.
2296 */
2297 static void
2298 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2299 {
2300 unsigned char *dp;
2301 int len;
2302
2303 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2304 return; /* no header */
2305 dp = skb->data + 2;
2306
2307 switch (CCP_CODE(dp)) {
2308 case CCP_CONFREQ:
2309
2310 /* A ConfReq starts negotiation of compression
2311 * in one direction of transmission,
2312 * and hence brings it down...but which way?
2313 *
2314 * Remember:
2315 * A ConfReq indicates what the sender would like to receive
2316 */
2317 if(inbound)
2318 /* He is proposing what I should send */
2319 ppp->xstate &= ~SC_COMP_RUN;
2320 else
2321 /* I am proposing to what he should send */
2322 ppp->rstate &= ~SC_DECOMP_RUN;
2323
2324 break;
2325
2326 case CCP_TERMREQ:
2327 case CCP_TERMACK:
2328 /*
2329 * CCP is going down, both directions of transmission
2330 */
2331 ppp->rstate &= ~SC_DECOMP_RUN;
2332 ppp->xstate &= ~SC_COMP_RUN;
2333 break;
2334
2335 case CCP_CONFACK:
2336 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2337 break;
2338 len = CCP_LENGTH(dp);
2339 if (!pskb_may_pull(skb, len + 2))
2340 return; /* too short */
2341 dp += CCP_HDRLEN;
2342 len -= CCP_HDRLEN;
2343 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2344 break;
2345 if (inbound) {
2346 /* we will start receiving compressed packets */
2347 if (!ppp->rc_state)
2348 break;
2349 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2350 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2351 ppp->rstate |= SC_DECOMP_RUN;
2352 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2353 }
2354 } else {
2355 /* we will soon start sending compressed packets */
2356 if (!ppp->xc_state)
2357 break;
2358 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2359 ppp->file.index, 0, ppp->debug))
2360 ppp->xstate |= SC_COMP_RUN;
2361 }
2362 break;
2363
2364 case CCP_RESETACK:
2365 /* reset the [de]compressor */
2366 if ((ppp->flags & SC_CCP_UP) == 0)
2367 break;
2368 if (inbound) {
2369 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2370 ppp->rcomp->decomp_reset(ppp->rc_state);
2371 ppp->rstate &= ~SC_DC_ERROR;
2372 }
2373 } else {
2374 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2375 ppp->xcomp->comp_reset(ppp->xc_state);
2376 }
2377 break;
2378 }
2379 }
2380
2381 /* Free up compression resources. */
2382 static void
2383 ppp_ccp_closed(struct ppp *ppp)
2384 {
2385 void *xstate, *rstate;
2386 struct compressor *xcomp, *rcomp;
2387
2388 ppp_lock(ppp);
2389 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2390 ppp->xstate = 0;
2391 xcomp = ppp->xcomp;
2392 xstate = ppp->xc_state;
2393 ppp->xc_state = NULL;
2394 ppp->rstate = 0;
2395 rcomp = ppp->rcomp;
2396 rstate = ppp->rc_state;
2397 ppp->rc_state = NULL;
2398 ppp_unlock(ppp);
2399
2400 if (xstate) {
2401 xcomp->comp_free(xstate);
2402 module_put(xcomp->owner);
2403 }
2404 if (rstate) {
2405 rcomp->decomp_free(rstate);
2406 module_put(rcomp->owner);
2407 }
2408 }
2409
2410 /* List of compressors. */
2411 static LIST_HEAD(compressor_list);
2412 static DEFINE_SPINLOCK(compressor_list_lock);
2413
2414 struct compressor_entry {
2415 struct list_head list;
2416 struct compressor *comp;
2417 };
2418
2419 static struct compressor_entry *
2420 find_comp_entry(int proto)
2421 {
2422 struct compressor_entry *ce;
2423
2424 list_for_each_entry(ce, &compressor_list, list) {
2425 if (ce->comp->compress_proto == proto)
2426 return ce;
2427 }
2428 return NULL;
2429 }
2430
2431 /* Register a compressor */
2432 int
2433 ppp_register_compressor(struct compressor *cp)
2434 {
2435 struct compressor_entry *ce;
2436 int ret;
2437 spin_lock(&compressor_list_lock);
2438 ret = -EEXIST;
2439 if (find_comp_entry(cp->compress_proto))
2440 goto out;
2441 ret = -ENOMEM;
2442 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2443 if (!ce)
2444 goto out;
2445 ret = 0;
2446 ce->comp = cp;
2447 list_add(&ce->list, &compressor_list);
2448 out:
2449 spin_unlock(&compressor_list_lock);
2450 return ret;
2451 }
2452
2453 /* Unregister a compressor */
2454 void
2455 ppp_unregister_compressor(struct compressor *cp)
2456 {
2457 struct compressor_entry *ce;
2458
2459 spin_lock(&compressor_list_lock);
2460 ce = find_comp_entry(cp->compress_proto);
2461 if (ce && ce->comp == cp) {
2462 list_del(&ce->list);
2463 kfree(ce);
2464 }
2465 spin_unlock(&compressor_list_lock);
2466 }
2467
2468 /* Find a compressor. */
2469 static struct compressor *
2470 find_compressor(int type)
2471 {
2472 struct compressor_entry *ce;
2473 struct compressor *cp = NULL;
2474
2475 spin_lock(&compressor_list_lock);
2476 ce = find_comp_entry(type);
2477 if (ce) {
2478 cp = ce->comp;
2479 if (!try_module_get(cp->owner))
2480 cp = NULL;
2481 }
2482 spin_unlock(&compressor_list_lock);
2483 return cp;
2484 }
2485
2486 /*
2487 * Miscelleneous stuff.
2488 */
2489
2490 static void
2491 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2492 {
2493 struct slcompress *vj = ppp->vj;
2494
2495 memset(st, 0, sizeof(*st));
2496 st->p.ppp_ipackets = ppp->dev->stats.rx_packets;
2497 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2498 st->p.ppp_ibytes = ppp->dev->stats.rx_bytes;
2499 st->p.ppp_opackets = ppp->dev->stats.tx_packets;
2500 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2501 st->p.ppp_obytes = ppp->dev->stats.tx_bytes;
2502 if (!vj)
2503 return;
2504 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2505 st->vj.vjs_compressed = vj->sls_o_compressed;
2506 st->vj.vjs_searches = vj->sls_o_searches;
2507 st->vj.vjs_misses = vj->sls_o_misses;
2508 st->vj.vjs_errorin = vj->sls_i_error;
2509 st->vj.vjs_tossed = vj->sls_i_tossed;
2510 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2511 st->vj.vjs_compressedin = vj->sls_i_compressed;
2512 }
2513
2514 /*
2515 * Stuff for handling the lists of ppp units and channels
2516 * and for initialization.
2517 */
2518
2519 /*
2520 * Create a new ppp interface unit. Fails if it can't allocate memory
2521 * or if there is already a unit with the requested number.
2522 * unit == -1 means allocate a new number.
2523 */
2524 static struct ppp *
2525 ppp_create_interface(struct net *net, int unit, int *retp)
2526 {
2527 struct ppp *ppp;
2528 struct ppp_net *pn;
2529 struct net_device *dev = NULL;
2530 int ret = -ENOMEM;
2531 int i;
2532
2533 dev = alloc_netdev(sizeof(struct ppp), "", ppp_setup);
2534 if (!dev)
2535 goto out1;
2536
2537 pn = ppp_pernet(net);
2538
2539 ppp = netdev_priv(dev);
2540 ppp->dev = dev;
2541 ppp->mru = PPP_MRU;
2542 init_ppp_file(&ppp->file, INTERFACE);
2543 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2544 for (i = 0; i < NUM_NP; ++i)
2545 ppp->npmode[i] = NPMODE_PASS;
2546 INIT_LIST_HEAD(&ppp->channels);
2547 spin_lock_init(&ppp->rlock);
2548 spin_lock_init(&ppp->wlock);
2549 #ifdef CONFIG_PPP_MULTILINK
2550 ppp->minseq = -1;
2551 skb_queue_head_init(&ppp->mrq);
2552 #endif /* CONFIG_PPP_MULTILINK */
2553
2554 /*
2555 * drum roll: don't forget to set
2556 * the net device is belong to
2557 */
2558 dev_net_set(dev, net);
2559
2560 ret = -EEXIST;
2561 mutex_lock(&pn->all_ppp_mutex);
2562
2563 if (unit < 0) {
2564 unit = unit_get(&pn->units_idr, ppp);
2565 if (unit < 0) {
2566 *retp = unit;
2567 goto out2;
2568 }
2569 } else {
2570 if (unit_find(&pn->units_idr, unit))
2571 goto out2; /* unit already exists */
2572 /*
2573 * if caller need a specified unit number
2574 * lets try to satisfy him, otherwise --
2575 * he should better ask us for new unit number
2576 *
2577 * NOTE: yes I know that returning EEXIST it's not
2578 * fair but at least pppd will ask us to allocate
2579 * new unit in this case so user is happy :)
2580 */
2581 unit = unit_set(&pn->units_idr, ppp, unit);
2582 if (unit < 0)
2583 goto out2;
2584 }
2585
2586 /* Initialize the new ppp unit */
2587 ppp->file.index = unit;
2588 sprintf(dev->name, "ppp%d", unit);
2589
2590 ret = register_netdev(dev);
2591 if (ret != 0) {
2592 unit_put(&pn->units_idr, unit);
2593 printk(KERN_ERR "PPP: couldn't register device %s (%d)\n",
2594 dev->name, ret);
2595 goto out2;
2596 }
2597
2598 ppp->ppp_net = net;
2599
2600 atomic_inc(&ppp_unit_count);
2601 mutex_unlock(&pn->all_ppp_mutex);
2602
2603 *retp = 0;
2604 return ppp;
2605
2606 out2:
2607 mutex_unlock(&pn->all_ppp_mutex);
2608 free_netdev(dev);
2609 out1:
2610 *retp = ret;
2611 return NULL;
2612 }
2613
2614 /*
2615 * Initialize a ppp_file structure.
2616 */
2617 static void
2618 init_ppp_file(struct ppp_file *pf, int kind)
2619 {
2620 pf->kind = kind;
2621 skb_queue_head_init(&pf->xq);
2622 skb_queue_head_init(&pf->rq);
2623 atomic_set(&pf->refcnt, 1);
2624 init_waitqueue_head(&pf->rwait);
2625 }
2626
2627 /*
2628 * Take down a ppp interface unit - called when the owning file
2629 * (the one that created the unit) is closed or detached.
2630 */
2631 static void ppp_shutdown_interface(struct ppp *ppp)
2632 {
2633 struct ppp_net *pn;
2634
2635 pn = ppp_pernet(ppp->ppp_net);
2636 mutex_lock(&pn->all_ppp_mutex);
2637
2638 /* This will call dev_close() for us. */
2639 ppp_lock(ppp);
2640 if (!ppp->closing) {
2641 ppp->closing = 1;
2642 ppp_unlock(ppp);
2643 unregister_netdev(ppp->dev);
2644 } else
2645 ppp_unlock(ppp);
2646
2647 unit_put(&pn->units_idr, ppp->file.index);
2648 ppp->file.dead = 1;
2649 ppp->owner = NULL;
2650 wake_up_interruptible(&ppp->file.rwait);
2651
2652 mutex_unlock(&pn->all_ppp_mutex);
2653 }
2654
2655 /*
2656 * Free the memory used by a ppp unit. This is only called once
2657 * there are no channels connected to the unit and no file structs
2658 * that reference the unit.
2659 */
2660 static void ppp_destroy_interface(struct ppp *ppp)
2661 {
2662 atomic_dec(&ppp_unit_count);
2663
2664 if (!ppp->file.dead || ppp->n_channels) {
2665 /* "can't happen" */
2666 printk(KERN_ERR "ppp: destroying ppp struct %p but dead=%d "
2667 "n_channels=%d !\n", ppp, ppp->file.dead,
2668 ppp->n_channels);
2669 return;
2670 }
2671
2672 ppp_ccp_closed(ppp);
2673 if (ppp->vj) {
2674 slhc_free(ppp->vj);
2675 ppp->vj = NULL;
2676 }
2677 skb_queue_purge(&ppp->file.xq);
2678 skb_queue_purge(&ppp->file.rq);
2679 #ifdef CONFIG_PPP_MULTILINK
2680 skb_queue_purge(&ppp->mrq);
2681 #endif /* CONFIG_PPP_MULTILINK */
2682 #ifdef CONFIG_PPP_FILTER
2683 kfree(ppp->pass_filter);
2684 ppp->pass_filter = NULL;
2685 kfree(ppp->active_filter);
2686 ppp->active_filter = NULL;
2687 #endif /* CONFIG_PPP_FILTER */
2688
2689 kfree_skb(ppp->xmit_pending);
2690
2691 free_netdev(ppp->dev);
2692 }
2693
2694 /*
2695 * Locate an existing ppp unit.
2696 * The caller should have locked the all_ppp_mutex.
2697 */
2698 static struct ppp *
2699 ppp_find_unit(struct ppp_net *pn, int unit)
2700 {
2701 return unit_find(&pn->units_idr, unit);
2702 }
2703
2704 /*
2705 * Locate an existing ppp channel.
2706 * The caller should have locked the all_channels_lock.
2707 * First we look in the new_channels list, then in the
2708 * all_channels list. If found in the new_channels list,
2709 * we move it to the all_channels list. This is for speed
2710 * when we have a lot of channels in use.
2711 */
2712 static struct channel *
2713 ppp_find_channel(struct ppp_net *pn, int unit)
2714 {
2715 struct channel *pch;
2716
2717 list_for_each_entry(pch, &pn->new_channels, list) {
2718 if (pch->file.index == unit) {
2719 list_move(&pch->list, &pn->all_channels);
2720 return pch;
2721 }
2722 }
2723
2724 list_for_each_entry(pch, &pn->all_channels, list) {
2725 if (pch->file.index == unit)
2726 return pch;
2727 }
2728
2729 return NULL;
2730 }
2731
2732 /*
2733 * Connect a PPP channel to a PPP interface unit.
2734 */
2735 static int
2736 ppp_connect_channel(struct channel *pch, int unit)
2737 {
2738 struct ppp *ppp;
2739 struct ppp_net *pn;
2740 int ret = -ENXIO;
2741 int hdrlen;
2742
2743 pn = ppp_pernet(pch->chan_net);
2744
2745 mutex_lock(&pn->all_ppp_mutex);
2746 ppp = ppp_find_unit(pn, unit);
2747 if (!ppp)
2748 goto out;
2749 write_lock_bh(&pch->upl);
2750 ret = -EINVAL;
2751 if (pch->ppp)
2752 goto outl;
2753
2754 ppp_lock(ppp);
2755 if (pch->file.hdrlen > ppp->file.hdrlen)
2756 ppp->file.hdrlen = pch->file.hdrlen;
2757 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2758 if (hdrlen > ppp->dev->hard_header_len)
2759 ppp->dev->hard_header_len = hdrlen;
2760 list_add_tail(&pch->clist, &ppp->channels);
2761 ++ppp->n_channels;
2762 pch->ppp = ppp;
2763 atomic_inc(&ppp->file.refcnt);
2764 ppp_unlock(ppp);
2765 ret = 0;
2766
2767 outl:
2768 write_unlock_bh(&pch->upl);
2769 out:
2770 mutex_unlock(&pn->all_ppp_mutex);
2771 return ret;
2772 }
2773
2774 /*
2775 * Disconnect a channel from its ppp unit.
2776 */
2777 static int
2778 ppp_disconnect_channel(struct channel *pch)
2779 {
2780 struct ppp *ppp;
2781 int err = -EINVAL;
2782
2783 write_lock_bh(&pch->upl);
2784 ppp = pch->ppp;
2785 pch->ppp = NULL;
2786 write_unlock_bh(&pch->upl);
2787 if (ppp) {
2788 /* remove it from the ppp unit's list */
2789 ppp_lock(ppp);
2790 list_del(&pch->clist);
2791 if (--ppp->n_channels == 0)
2792 wake_up_interruptible(&ppp->file.rwait);
2793 ppp_unlock(ppp);
2794 if (atomic_dec_and_test(&ppp->file.refcnt))
2795 ppp_destroy_interface(ppp);
2796 err = 0;
2797 }
2798 return err;
2799 }
2800
2801 /*
2802 * Free up the resources used by a ppp channel.
2803 */
2804 static void ppp_destroy_channel(struct channel *pch)
2805 {
2806 atomic_dec(&channel_count);
2807
2808 if (!pch->file.dead) {
2809 /* "can't happen" */
2810 printk(KERN_ERR "ppp: destroying undead channel %p !\n",
2811 pch);
2812 return;
2813 }
2814 skb_queue_purge(&pch->file.xq);
2815 skb_queue_purge(&pch->file.rq);
2816 kfree(pch);
2817 }
2818
2819 static void __exit ppp_cleanup(void)
2820 {
2821 /* should never happen */
2822 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2823 printk(KERN_ERR "PPP: removing module but units remain!\n");
2824 unregister_chrdev(PPP_MAJOR, "ppp");
2825 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
2826 class_destroy(ppp_class);
2827 unregister_pernet_gen_device(ppp_net_id, &ppp_net_ops);
2828 }
2829
2830 /*
2831 * Units handling. Caller must protect concurrent access
2832 * by holding all_ppp_mutex
2833 */
2834
2835 /* associate pointer with specified number */
2836 static int unit_set(struct idr *p, void *ptr, int n)
2837 {
2838 int unit, err;
2839
2840 again:
2841 if (!idr_pre_get(p, GFP_KERNEL)) {
2842 printk(KERN_ERR "PPP: No free memory for idr\n");
2843 return -ENOMEM;
2844 }
2845
2846 err = idr_get_new_above(p, ptr, n, &unit);
2847 if (err == -EAGAIN)
2848 goto again;
2849
2850 if (unit != n) {
2851 idr_remove(p, unit);
2852 return -EINVAL;
2853 }
2854
2855 return unit;
2856 }
2857
2858 /* get new free unit number and associate pointer with it */
2859 static int unit_get(struct idr *p, void *ptr)
2860 {
2861 int unit, err;
2862
2863 again:
2864 if (!idr_pre_get(p, GFP_KERNEL)) {
2865 printk(KERN_ERR "PPP: No free memory for idr\n");
2866 return -ENOMEM;
2867 }
2868
2869 err = idr_get_new_above(p, ptr, 0, &unit);
2870 if (err == -EAGAIN)
2871 goto again;
2872
2873 return unit;
2874 }
2875
2876 /* put unit number back to a pool */
2877 static void unit_put(struct idr *p, int n)
2878 {
2879 idr_remove(p, n);
2880 }
2881
2882 /* get pointer associated with the number */
2883 static void *unit_find(struct idr *p, int n)
2884 {
2885 return idr_find(p, n);
2886 }
2887
2888 /* Module/initialization stuff */
2889
2890 module_init(ppp_init);
2891 module_exit(ppp_cleanup);
2892
2893 EXPORT_SYMBOL(ppp_register_net_channel);
2894 EXPORT_SYMBOL(ppp_register_channel);
2895 EXPORT_SYMBOL(ppp_unregister_channel);
2896 EXPORT_SYMBOL(ppp_channel_index);
2897 EXPORT_SYMBOL(ppp_unit_number);
2898 EXPORT_SYMBOL(ppp_input);
2899 EXPORT_SYMBOL(ppp_input_error);
2900 EXPORT_SYMBOL(ppp_output_wakeup);
2901 EXPORT_SYMBOL(ppp_register_compressor);
2902 EXPORT_SYMBOL(ppp_unregister_compressor);
2903 MODULE_LICENSE("GPL");
2904 MODULE_ALIAS_CHARDEV_MAJOR(PPP_MAJOR);
2905 MODULE_ALIAS("/dev/ppp");
Support for the Chinese Samsung S3C2440 based development boards