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proc: use seq_puts()/seq_putc() where possible
[linux-2.6/next.git] / drivers / net / ppp_generic.c
blobc7a6c4466978d620353b4db6fa8058f377d228a4
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/spinlock.h>
44 #include <linux/rwsem.h>
45 #include <linux/stddef.h>
46 #include <linux/device.h>
47 #include <linux/mutex.h>
48 #include <linux/slab.h>
49 #include <asm/unaligned.h>
50 #include <net/slhc_vj.h>
51 #include <asm/atomic.h>
52
53 #include <linux/nsproxy.h>
54 #include <net/net_namespace.h>
55 #include <net/netns/generic.h>
56
57 #define PPP_VERSION "2.4.2"
58
59 /*
60 * Network protocols we support.
61 */
62 #define NP_IP 0 /* Internet Protocol V4 */
63 #define NP_IPV6 1 /* Internet Protocol V6 */
64 #define NP_IPX 2 /* IPX protocol */
65 #define NP_AT 3 /* Appletalk protocol */
66 #define NP_MPLS_UC 4 /* MPLS unicast */
67 #define NP_MPLS_MC 5 /* MPLS multicast */
68 #define NUM_NP 6 /* Number of NPs. */
69
70 #define MPHDRLEN 6 /* multilink protocol header length */
71 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */
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 DEFINE_MUTEX(ppp_mutex);
184 static atomic_t ppp_unit_count = ATOMIC_INIT(0);
185 static atomic_t channel_count = ATOMIC_INIT(0);
186
187 /* per-net private data for this module */
188 static int ppp_net_id __read_mostly;
189 struct ppp_net {
190 /* units to ppp mapping */
191 struct idr units_idr;
192
193 /*
194 * all_ppp_mutex protects the units_idr mapping.
195 * It also ensures that finding a ppp unit in the units_idr
196 * map and updating its file.refcnt field is atomic.
197 */
198 struct mutex all_ppp_mutex;
199
200 /* channels */
201 struct list_head all_channels;
202 struct list_head new_channels;
203 int last_channel_index;
204
205 /*
206 * all_channels_lock protects all_channels and
207 * last_channel_index, and the atomicity of find
208 * a channel and updating its file.refcnt field.
209 */
210 spinlock_t all_channels_lock;
211 };
212
213 /* Get the PPP protocol number from a skb */
214 #define PPP_PROTO(skb) get_unaligned_be16((skb)->data)
215
216 /* We limit the length of ppp->file.rq to this (arbitrary) value */
217 #define PPP_MAX_RQLEN 32
218
219 /*
220 * Maximum number of multilink fragments queued up.
221 * This has to be large enough to cope with the maximum latency of
222 * the slowest channel relative to the others. Strictly it should
223 * depend on the number of channels and their characteristics.
224 */
225 #define PPP_MP_MAX_QLEN 128
226
227 /* Multilink header bits. */
228 #define B 0x80 /* this fragment begins a packet */
229 #define E 0x40 /* this fragment ends a packet */
230
231 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */
232 #define seq_before(a, b) ((s32)((a) - (b)) < 0)
233 #define seq_after(a, b) ((s32)((a) - (b)) > 0)
234
235 /* Prototypes. */
236 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
237 struct file *file, unsigned int cmd, unsigned long arg);
238 static void ppp_xmit_process(struct ppp *ppp);
239 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
240 static void ppp_push(struct ppp *ppp);
241 static void ppp_channel_push(struct channel *pch);
242 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
243 struct channel *pch);
244 static void ppp_receive_error(struct ppp *ppp);
245 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
246 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
247 struct sk_buff *skb);
248 #ifdef CONFIG_PPP_MULTILINK
249 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
250 struct channel *pch);
251 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
252 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
253 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
254 #endif /* CONFIG_PPP_MULTILINK */
255 static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
256 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
257 static void ppp_ccp_closed(struct ppp *ppp);
258 static struct compressor *find_compressor(int type);
259 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
260 static struct ppp *ppp_create_interface(struct net *net, int unit, int *retp);
261 static void init_ppp_file(struct ppp_file *pf, int kind);
262 static void ppp_shutdown_interface(struct ppp *ppp);
263 static void ppp_destroy_interface(struct ppp *ppp);
264 static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit);
265 static struct channel *ppp_find_channel(struct ppp_net *pn, int unit);
266 static int ppp_connect_channel(struct channel *pch, int unit);
267 static int ppp_disconnect_channel(struct channel *pch);
268 static void ppp_destroy_channel(struct channel *pch);
269 static int unit_get(struct idr *p, void *ptr);
270 static int unit_set(struct idr *p, void *ptr, int n);
271 static void unit_put(struct idr *p, int n);
272 static void *unit_find(struct idr *p, int n);
273
274 static struct class *ppp_class;
275
276 /* per net-namespace data */
277 static inline struct ppp_net *ppp_pernet(struct net *net)
278 {
279 BUG_ON(!net);
280
281 return net_generic(net, ppp_net_id);
282 }
283
284 /* Translates a PPP protocol number to a NP index (NP == network protocol) */
285 static inline int proto_to_npindex(int proto)
286 {
287 switch (proto) {
288 case PPP_IP:
289 return NP_IP;
290 case PPP_IPV6:
291 return NP_IPV6;
292 case PPP_IPX:
293 return NP_IPX;
294 case PPP_AT:
295 return NP_AT;
296 case PPP_MPLS_UC:
297 return NP_MPLS_UC;
298 case PPP_MPLS_MC:
299 return NP_MPLS_MC;
300 }
301 return -EINVAL;
302 }
303
304 /* Translates an NP index into a PPP protocol number */
305 static const int npindex_to_proto[NUM_NP] = {
306 PPP_IP,
307 PPP_IPV6,
308 PPP_IPX,
309 PPP_AT,
310 PPP_MPLS_UC,
311 PPP_MPLS_MC,
312 };
313
314 /* Translates an ethertype into an NP index */
315 static inline int ethertype_to_npindex(int ethertype)
316 {
317 switch (ethertype) {
318 case ETH_P_IP:
319 return NP_IP;
320 case ETH_P_IPV6:
321 return NP_IPV6;
322 case ETH_P_IPX:
323 return NP_IPX;
324 case ETH_P_PPPTALK:
325 case ETH_P_ATALK:
326 return NP_AT;
327 case ETH_P_MPLS_UC:
328 return NP_MPLS_UC;
329 case ETH_P_MPLS_MC:
330 return NP_MPLS_MC;
331 }
332 return -1;
333 }
334
335 /* Translates an NP index into an ethertype */
336 static const int npindex_to_ethertype[NUM_NP] = {
337 ETH_P_IP,
338 ETH_P_IPV6,
339 ETH_P_IPX,
340 ETH_P_PPPTALK,
341 ETH_P_MPLS_UC,
342 ETH_P_MPLS_MC,
343 };
344
345 /*
346 * Locking shorthand.
347 */
348 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
349 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
350 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
351 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
352 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
353 ppp_recv_lock(ppp); } while (0)
354 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
355 ppp_xmit_unlock(ppp); } while (0)
356
357 /*
358 * /dev/ppp device routines.
359 * The /dev/ppp device is used by pppd to control the ppp unit.
360 * It supports the read, write, ioctl and poll functions.
361 * Open instances of /dev/ppp can be in one of three states:
362 * unattached, attached to a ppp unit, or attached to a ppp channel.
363 */
364 static int ppp_open(struct inode *inode, struct file *file)
365 {
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 struct iovec iov;
408
409 ret = count;
410
411 if (!pf)
412 return -ENXIO;
413 add_wait_queue(&pf->rwait, &wait);
414 for (;;) {
415 set_current_state(TASK_INTERRUPTIBLE);
416 skb = skb_dequeue(&pf->rq);
417 if (skb)
418 break;
419 ret = 0;
420 if (pf->dead)
421 break;
422 if (pf->kind == INTERFACE) {
423 /*
424 * Return 0 (EOF) on an interface that has no
425 * channels connected, unless it is looping
426 * network traffic (demand mode).
427 */
428 struct ppp *ppp = PF_TO_PPP(pf);
429 if (ppp->n_channels == 0 &&
430 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
431 break;
432 }
433 ret = -EAGAIN;
434 if (file->f_flags & O_NONBLOCK)
435 break;
436 ret = -ERESTARTSYS;
437 if (signal_pending(current))
438 break;
439 schedule();
440 }
441 set_current_state(TASK_RUNNING);
442 remove_wait_queue(&pf->rwait, &wait);
443
444 if (!skb)
445 goto out;
446
447 ret = -EOVERFLOW;
448 if (skb->len > count)
449 goto outf;
450 ret = -EFAULT;
451 iov.iov_base = buf;
452 iov.iov_len = count;
453 if (skb_copy_datagram_iovec(skb, 0, &iov, skb->len))
454 goto outf;
455 ret = skb->len;
456
457 outf:
458 kfree_skb(skb);
459 out:
460 return ret;
461 }
462
463 static ssize_t ppp_write(struct file *file, const char __user *buf,
464 size_t count, loff_t *ppos)
465 {
466 struct ppp_file *pf = file->private_data;
467 struct sk_buff *skb;
468 ssize_t ret;
469
470 if (!pf)
471 return -ENXIO;
472 ret = -ENOMEM;
473 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
474 if (!skb)
475 goto out;
476 skb_reserve(skb, pf->hdrlen);
477 ret = -EFAULT;
478 if (copy_from_user(skb_put(skb, count), buf, count)) {
479 kfree_skb(skb);
480 goto out;
481 }
482
483 skb_queue_tail(&pf->xq, skb);
484
485 switch (pf->kind) {
486 case INTERFACE:
487 ppp_xmit_process(PF_TO_PPP(pf));
488 break;
489 case CHANNEL:
490 ppp_channel_push(PF_TO_CHANNEL(pf));
491 break;
492 }
493
494 ret = count;
495
496 out:
497 return ret;
498 }
499
500 /* No kernel lock - fine */
501 static unsigned int ppp_poll(struct file *file, poll_table *wait)
502 {
503 struct ppp_file *pf = file->private_data;
504 unsigned int mask;
505
506 if (!pf)
507 return 0;
508 poll_wait(file, &pf->rwait, wait);
509 mask = POLLOUT | POLLWRNORM;
510 if (skb_peek(&pf->rq))
511 mask |= POLLIN | POLLRDNORM;
512 if (pf->dead)
513 mask |= POLLHUP;
514 else if (pf->kind == INTERFACE) {
515 /* see comment in ppp_read */
516 struct ppp *ppp = PF_TO_PPP(pf);
517 if (ppp->n_channels == 0 &&
518 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
519 mask |= POLLIN | POLLRDNORM;
520 }
521
522 return mask;
523 }
524
525 #ifdef CONFIG_PPP_FILTER
526 static int get_filter(void __user *arg, struct sock_filter **p)
527 {
528 struct sock_fprog uprog;
529 struct sock_filter *code = NULL;
530 int len, err;
531
532 if (copy_from_user(&uprog, arg, sizeof(uprog)))
533 return -EFAULT;
534
535 if (!uprog.len) {
536 *p = NULL;
537 return 0;
538 }
539
540 len = uprog.len * sizeof(struct sock_filter);
541 code = memdup_user(uprog.filter, len);
542 if (IS_ERR(code))
543 return PTR_ERR(code);
544
545 err = sk_chk_filter(code, uprog.len);
546 if (err) {
547 kfree(code);
548 return err;
549 }
550
551 *p = code;
552 return uprog.len;
553 }
554 #endif /* CONFIG_PPP_FILTER */
555
556 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
557 {
558 struct ppp_file *pf = file->private_data;
559 struct ppp *ppp;
560 int err = -EFAULT, val, val2, i;
561 struct ppp_idle idle;
562 struct npioctl npi;
563 int unit, cflags;
564 struct slcompress *vj;
565 void __user *argp = (void __user *)arg;
566 int __user *p = argp;
567
568 if (!pf)
569 return ppp_unattached_ioctl(current->nsproxy->net_ns,
570 pf, file, cmd, arg);
571
572 if (cmd == PPPIOCDETACH) {
573 /*
574 * We have to be careful here... if the file descriptor
575 * has been dup'd, we could have another process in the
576 * middle of a poll using the same file *, so we had
577 * better not free the interface data structures -
578 * instead we fail the ioctl. Even in this case, we
579 * shut down the interface if we are the owner of it.
580 * Actually, we should get rid of PPPIOCDETACH, userland
581 * (i.e. pppd) could achieve the same effect by closing
582 * this fd and reopening /dev/ppp.
583 */
584 err = -EINVAL;
585 mutex_lock(&ppp_mutex);
586 if (pf->kind == INTERFACE) {
587 ppp = PF_TO_PPP(pf);
588 if (file == ppp->owner)
589 ppp_shutdown_interface(ppp);
590 }
591 if (atomic_long_read(&file->f_count) <= 2) {
592 ppp_release(NULL, file);
593 err = 0;
594 } else
595 printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%ld\n",
596 atomic_long_read(&file->f_count));
597 mutex_unlock(&ppp_mutex);
598 return err;
599 }
600
601 if (pf->kind == CHANNEL) {
602 struct channel *pch;
603 struct ppp_channel *chan;
604
605 mutex_lock(&ppp_mutex);
606 pch = PF_TO_CHANNEL(pf);
607
608 switch (cmd) {
609 case PPPIOCCONNECT:
610 if (get_user(unit, p))
611 break;
612 err = ppp_connect_channel(pch, unit);
613 break;
614
615 case PPPIOCDISCONN:
616 err = ppp_disconnect_channel(pch);
617 break;
618
619 default:
620 down_read(&pch->chan_sem);
621 chan = pch->chan;
622 err = -ENOTTY;
623 if (chan && chan->ops->ioctl)
624 err = chan->ops->ioctl(chan, cmd, arg);
625 up_read(&pch->chan_sem);
626 }
627 mutex_unlock(&ppp_mutex);
628 return err;
629 }
630
631 if (pf->kind != INTERFACE) {
632 /* can't happen */
633 printk(KERN_ERR "PPP: not interface or channel??\n");
634 return -EINVAL;
635 }
636
637 mutex_lock(&ppp_mutex);
638 ppp = PF_TO_PPP(pf);
639 switch (cmd) {
640 case PPPIOCSMRU:
641 if (get_user(val, p))
642 break;
643 ppp->mru = val;
644 err = 0;
645 break;
646
647 case PPPIOCSFLAGS:
648 if (get_user(val, p))
649 break;
650 ppp_lock(ppp);
651 cflags = ppp->flags & ~val;
652 ppp->flags = val & SC_FLAG_BITS;
653 ppp_unlock(ppp);
654 if (cflags & SC_CCP_OPEN)
655 ppp_ccp_closed(ppp);
656 err = 0;
657 break;
658
659 case PPPIOCGFLAGS:
660 val = ppp->flags | ppp->xstate | ppp->rstate;
661 if (put_user(val, p))
662 break;
663 err = 0;
664 break;
665
666 case PPPIOCSCOMPRESS:
667 err = ppp_set_compress(ppp, arg);
668 break;
669
670 case PPPIOCGUNIT:
671 if (put_user(ppp->file.index, p))
672 break;
673 err = 0;
674 break;
675
676 case PPPIOCSDEBUG:
677 if (get_user(val, p))
678 break;
679 ppp->debug = val;
680 err = 0;
681 break;
682
683 case PPPIOCGDEBUG:
684 if (put_user(ppp->debug, p))
685 break;
686 err = 0;
687 break;
688
689 case PPPIOCGIDLE:
690 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
691 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
692 if (copy_to_user(argp, &idle, sizeof(idle)))
693 break;
694 err = 0;
695 break;
696
697 case PPPIOCSMAXCID:
698 if (get_user(val, p))
699 break;
700 val2 = 15;
701 if ((val >> 16) != 0) {
702 val2 = val >> 16;
703 val &= 0xffff;
704 }
705 vj = slhc_init(val2+1, val+1);
706 if (!vj) {
707 printk(KERN_ERR "PPP: no memory (VJ compressor)\n");
708 err = -ENOMEM;
709 break;
710 }
711 ppp_lock(ppp);
712 if (ppp->vj)
713 slhc_free(ppp->vj);
714 ppp->vj = vj;
715 ppp_unlock(ppp);
716 err = 0;
717 break;
718
719 case PPPIOCGNPMODE:
720 case PPPIOCSNPMODE:
721 if (copy_from_user(&npi, argp, sizeof(npi)))
722 break;
723 err = proto_to_npindex(npi.protocol);
724 if (err < 0)
725 break;
726 i = err;
727 if (cmd == PPPIOCGNPMODE) {
728 err = -EFAULT;
729 npi.mode = ppp->npmode[i];
730 if (copy_to_user(argp, &npi, sizeof(npi)))
731 break;
732 } else {
733 ppp->npmode[i] = npi.mode;
734 /* we may be able to transmit more packets now (??) */
735 netif_wake_queue(ppp->dev);
736 }
737 err = 0;
738 break;
739
740 #ifdef CONFIG_PPP_FILTER
741 case PPPIOCSPASS:
742 {
743 struct sock_filter *code;
744 err = get_filter(argp, &code);
745 if (err >= 0) {
746 ppp_lock(ppp);
747 kfree(ppp->pass_filter);
748 ppp->pass_filter = code;
749 ppp->pass_len = err;
750 ppp_unlock(ppp);
751 err = 0;
752 }
753 break;
754 }
755 case PPPIOCSACTIVE:
756 {
757 struct sock_filter *code;
758 err = get_filter(argp, &code);
759 if (err >= 0) {
760 ppp_lock(ppp);
761 kfree(ppp->active_filter);
762 ppp->active_filter = code;
763 ppp->active_len = err;
764 ppp_unlock(ppp);
765 err = 0;
766 }
767 break;
768 }
769 #endif /* CONFIG_PPP_FILTER */
770
771 #ifdef CONFIG_PPP_MULTILINK
772 case PPPIOCSMRRU:
773 if (get_user(val, p))
774 break;
775 ppp_recv_lock(ppp);
776 ppp->mrru = val;
777 ppp_recv_unlock(ppp);
778 err = 0;
779 break;
780 #endif /* CONFIG_PPP_MULTILINK */
781
782 default:
783 err = -ENOTTY;
784 }
785 mutex_unlock(&ppp_mutex);
786 return err;
787 }
788
789 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
790 struct file *file, unsigned int cmd, unsigned long arg)
791 {
792 int unit, err = -EFAULT;
793 struct ppp *ppp;
794 struct channel *chan;
795 struct ppp_net *pn;
796 int __user *p = (int __user *)arg;
797
798 mutex_lock(&ppp_mutex);
799 switch (cmd) {
800 case PPPIOCNEWUNIT:
801 /* Create a new ppp unit */
802 if (get_user(unit, p))
803 break;
804 ppp = ppp_create_interface(net, unit, &err);
805 if (!ppp)
806 break;
807 file->private_data = &ppp->file;
808 ppp->owner = file;
809 err = -EFAULT;
810 if (put_user(ppp->file.index, p))
811 break;
812 err = 0;
813 break;
814
815 case PPPIOCATTACH:
816 /* Attach to an existing ppp unit */
817 if (get_user(unit, p))
818 break;
819 err = -ENXIO;
820 pn = ppp_pernet(net);
821 mutex_lock(&pn->all_ppp_mutex);
822 ppp = ppp_find_unit(pn, unit);
823 if (ppp) {
824 atomic_inc(&ppp->file.refcnt);
825 file->private_data = &ppp->file;
826 err = 0;
827 }
828 mutex_unlock(&pn->all_ppp_mutex);
829 break;
830
831 case PPPIOCATTCHAN:
832 if (get_user(unit, p))
833 break;
834 err = -ENXIO;
835 pn = ppp_pernet(net);
836 spin_lock_bh(&pn->all_channels_lock);
837 chan = ppp_find_channel(pn, unit);
838 if (chan) {
839 atomic_inc(&chan->file.refcnt);
840 file->private_data = &chan->file;
841 err = 0;
842 }
843 spin_unlock_bh(&pn->all_channels_lock);
844 break;
845
846 default:
847 err = -ENOTTY;
848 }
849 mutex_unlock(&ppp_mutex);
850 return err;
851 }
852
853 static const struct file_operations ppp_device_fops = {
854 .owner = THIS_MODULE,
855 .read = ppp_read,
856 .write = ppp_write,
857 .poll = ppp_poll,
858 .unlocked_ioctl = ppp_ioctl,
859 .open = ppp_open,
860 .release = ppp_release,
861 .llseek = noop_llseek,
862 };
863
864 static __net_init int ppp_init_net(struct net *net)
865 {
866 struct ppp_net *pn = net_generic(net, ppp_net_id);
867
868 idr_init(&pn->units_idr);
869 mutex_init(&pn->all_ppp_mutex);
870
871 INIT_LIST_HEAD(&pn->all_channels);
872 INIT_LIST_HEAD(&pn->new_channels);
873
874 spin_lock_init(&pn->all_channels_lock);
875
876 return 0;
877 }
878
879 static __net_exit void ppp_exit_net(struct net *net)
880 {
881 struct ppp_net *pn = net_generic(net, ppp_net_id);
882
883 idr_destroy(&pn->units_idr);
884 }
885
886 static struct pernet_operations ppp_net_ops = {
887 .init = ppp_init_net,
888 .exit = ppp_exit_net,
889 .id = &ppp_net_id,
890 .size = sizeof(struct ppp_net),
891 };
892
893 #define PPP_MAJOR 108
894
895 /* Called at boot time if ppp is compiled into the kernel,
896 or at module load time (from init_module) if compiled as a module. */
897 static int __init ppp_init(void)
898 {
899 int err;
900
901 printk(KERN_INFO "PPP generic driver version " PPP_VERSION "\n");
902
903 err = register_pernet_device(&ppp_net_ops);
904 if (err) {
905 printk(KERN_ERR "failed to register PPP pernet device (%d)\n", err);
906 goto out;
907 }
908
909 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
910 if (err) {
911 printk(KERN_ERR "failed to register PPP device (%d)\n", err);
912 goto out_net;
913 }
914
915 ppp_class = class_create(THIS_MODULE, "ppp");
916 if (IS_ERR(ppp_class)) {
917 err = PTR_ERR(ppp_class);
918 goto out_chrdev;
919 }
920
921 /* not a big deal if we fail here :-) */
922 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
923
924 return 0;
925
926 out_chrdev:
927 unregister_chrdev(PPP_MAJOR, "ppp");
928 out_net:
929 unregister_pernet_device(&ppp_net_ops);
930 out:
931 return err;
932 }
933
934 /*
935 * Network interface unit routines.
936 */
937 static netdev_tx_t
938 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
939 {
940 struct ppp *ppp = netdev_priv(dev);
941 int npi, proto;
942 unsigned char *pp;
943
944 npi = ethertype_to_npindex(ntohs(skb->protocol));
945 if (npi < 0)
946 goto outf;
947
948 /* Drop, accept or reject the packet */
949 switch (ppp->npmode[npi]) {
950 case NPMODE_PASS:
951 break;
952 case NPMODE_QUEUE:
953 /* it would be nice to have a way to tell the network
954 system to queue this one up for later. */
955 goto outf;
956 case NPMODE_DROP:
957 case NPMODE_ERROR:
958 goto outf;
959 }
960
961 /* Put the 2-byte PPP protocol number on the front,
962 making sure there is room for the address and control fields. */
963 if (skb_cow_head(skb, PPP_HDRLEN))
964 goto outf;
965
966 pp = skb_push(skb, 2);
967 proto = npindex_to_proto[npi];
968 put_unaligned_be16(proto, pp);
969
970 netif_stop_queue(dev);
971 skb_queue_tail(&ppp->file.xq, skb);
972 ppp_xmit_process(ppp);
973 return NETDEV_TX_OK;
974
975 outf:
976 kfree_skb(skb);
977 ++dev->stats.tx_dropped;
978 return NETDEV_TX_OK;
979 }
980
981 static int
982 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
983 {
984 struct ppp *ppp = netdev_priv(dev);
985 int err = -EFAULT;
986 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
987 struct ppp_stats stats;
988 struct ppp_comp_stats cstats;
989 char *vers;
990
991 switch (cmd) {
992 case SIOCGPPPSTATS:
993 ppp_get_stats(ppp, &stats);
994 if (copy_to_user(addr, &stats, sizeof(stats)))
995 break;
996 err = 0;
997 break;
998
999 case SIOCGPPPCSTATS:
1000 memset(&cstats, 0, sizeof(cstats));
1001 if (ppp->xc_state)
1002 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
1003 if (ppp->rc_state)
1004 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
1005 if (copy_to_user(addr, &cstats, sizeof(cstats)))
1006 break;
1007 err = 0;
1008 break;
1009
1010 case SIOCGPPPVER:
1011 vers = PPP_VERSION;
1012 if (copy_to_user(addr, vers, strlen(vers) + 1))
1013 break;
1014 err = 0;
1015 break;
1016
1017 default:
1018 err = -EINVAL;
1019 }
1020
1021 return err;
1022 }
1023
1024 static const struct net_device_ops ppp_netdev_ops = {
1025 .ndo_start_xmit = ppp_start_xmit,
1026 .ndo_do_ioctl = ppp_net_ioctl,
1027 };
1028
1029 static void ppp_setup(struct net_device *dev)
1030 {
1031 dev->netdev_ops = &ppp_netdev_ops;
1032 dev->hard_header_len = PPP_HDRLEN;
1033 dev->mtu = PPP_MTU;
1034 dev->addr_len = 0;
1035 dev->tx_queue_len = 3;
1036 dev->type = ARPHRD_PPP;
1037 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1038 dev->features |= NETIF_F_NETNS_LOCAL;
1039 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1040 }
1041
1042 /*
1043 * Transmit-side routines.
1044 */
1045
1046 /*
1047 * Called to do any work queued up on the transmit side
1048 * that can now be done.
1049 */
1050 static void
1051 ppp_xmit_process(struct ppp *ppp)
1052 {
1053 struct sk_buff *skb;
1054
1055 ppp_xmit_lock(ppp);
1056 if (!ppp->closing) {
1057 ppp_push(ppp);
1058 while (!ppp->xmit_pending &&
1059 (skb = skb_dequeue(&ppp->file.xq)))
1060 ppp_send_frame(ppp, skb);
1061 /* If there's no work left to do, tell the core net
1062 code that we can accept some more. */
1063 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1064 netif_wake_queue(ppp->dev);
1065 }
1066 ppp_xmit_unlock(ppp);
1067 }
1068
1069 static inline struct sk_buff *
1070 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1071 {
1072 struct sk_buff *new_skb;
1073 int len;
1074 int new_skb_size = ppp->dev->mtu +
1075 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1076 int compressor_skb_size = ppp->dev->mtu +
1077 ppp->xcomp->comp_extra + PPP_HDRLEN;
1078 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1079 if (!new_skb) {
1080 if (net_ratelimit())
1081 printk(KERN_ERR "PPP: no memory (comp pkt)\n");
1082 return NULL;
1083 }
1084 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1085 skb_reserve(new_skb,
1086 ppp->dev->hard_header_len - PPP_HDRLEN);
1087
1088 /* compressor still expects A/C bytes in hdr */
1089 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1090 new_skb->data, skb->len + 2,
1091 compressor_skb_size);
1092 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1093 kfree_skb(skb);
1094 skb = new_skb;
1095 skb_put(skb, len);
1096 skb_pull(skb, 2); /* pull off A/C bytes */
1097 } else if (len == 0) {
1098 /* didn't compress, or CCP not up yet */
1099 kfree_skb(new_skb);
1100 new_skb = skb;
1101 } else {
1102 /*
1103 * (len < 0)
1104 * MPPE requires that we do not send unencrypted
1105 * frames. The compressor will return -1 if we
1106 * should drop the frame. We cannot simply test
1107 * the compress_proto because MPPE and MPPC share
1108 * the same number.
1109 */
1110 if (net_ratelimit())
1111 printk(KERN_ERR "ppp: compressor dropped pkt\n");
1112 kfree_skb(skb);
1113 kfree_skb(new_skb);
1114 new_skb = NULL;
1115 }
1116 return new_skb;
1117 }
1118
1119 /*
1120 * Compress and send a frame.
1121 * The caller should have locked the xmit path,
1122 * and xmit_pending should be 0.
1123 */
1124 static void
1125 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1126 {
1127 int proto = PPP_PROTO(skb);
1128 struct sk_buff *new_skb;
1129 int len;
1130 unsigned char *cp;
1131
1132 if (proto < 0x8000) {
1133 #ifdef CONFIG_PPP_FILTER
1134 /* check if we should pass this packet */
1135 /* the filter instructions are constructed assuming
1136 a four-byte PPP header on each packet */
1137 *skb_push(skb, 2) = 1;
1138 if (ppp->pass_filter &&
1139 sk_run_filter(skb, ppp->pass_filter) == 0) {
1140 if (ppp->debug & 1)
1141 printk(KERN_DEBUG "PPP: outbound frame not passed\n");
1142 kfree_skb(skb);
1143 return;
1144 }
1145 /* if this packet passes the active filter, record the time */
1146 if (!(ppp->active_filter &&
1147 sk_run_filter(skb, ppp->active_filter) == 0))
1148 ppp->last_xmit = jiffies;
1149 skb_pull(skb, 2);
1150 #else
1151 /* for data packets, record the time */
1152 ppp->last_xmit = jiffies;
1153 #endif /* CONFIG_PPP_FILTER */
1154 }
1155
1156 ++ppp->dev->stats.tx_packets;
1157 ppp->dev->stats.tx_bytes += skb->len - 2;
1158
1159 switch (proto) {
1160 case PPP_IP:
1161 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1162 break;
1163 /* try to do VJ TCP header compression */
1164 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1165 GFP_ATOMIC);
1166 if (!new_skb) {
1167 printk(KERN_ERR "PPP: no memory (VJ comp pkt)\n");
1168 goto drop;
1169 }
1170 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1171 cp = skb->data + 2;
1172 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1173 new_skb->data + 2, &cp,
1174 !(ppp->flags & SC_NO_TCP_CCID));
1175 if (cp == skb->data + 2) {
1176 /* didn't compress */
1177 kfree_skb(new_skb);
1178 } else {
1179 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1180 proto = PPP_VJC_COMP;
1181 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1182 } else {
1183 proto = PPP_VJC_UNCOMP;
1184 cp[0] = skb->data[2];
1185 }
1186 kfree_skb(skb);
1187 skb = new_skb;
1188 cp = skb_put(skb, len + 2);
1189 cp[0] = 0;
1190 cp[1] = proto;
1191 }
1192 break;
1193
1194 case PPP_CCP:
1195 /* peek at outbound CCP frames */
1196 ppp_ccp_peek(ppp, skb, 0);
1197 break;
1198 }
1199
1200 /* try to do packet compression */
1201 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state &&
1202 proto != PPP_LCP && proto != PPP_CCP) {
1203 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1204 if (net_ratelimit())
1205 printk(KERN_ERR "ppp: compression required but down - pkt dropped.\n");
1206 goto drop;
1207 }
1208 skb = pad_compress_skb(ppp, skb);
1209 if (!skb)
1210 goto drop;
1211 }
1212
1213 /*
1214 * If we are waiting for traffic (demand dialling),
1215 * queue it up for pppd to receive.
1216 */
1217 if (ppp->flags & SC_LOOP_TRAFFIC) {
1218 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1219 goto drop;
1220 skb_queue_tail(&ppp->file.rq, skb);
1221 wake_up_interruptible(&ppp->file.rwait);
1222 return;
1223 }
1224
1225 ppp->xmit_pending = skb;
1226 ppp_push(ppp);
1227 return;
1228
1229 drop:
1230 kfree_skb(skb);
1231 ++ppp->dev->stats.tx_errors;
1232 }
1233
1234 /*
1235 * Try to send the frame in xmit_pending.
1236 * The caller should have the xmit path locked.
1237 */
1238 static void
1239 ppp_push(struct ppp *ppp)
1240 {
1241 struct list_head *list;
1242 struct channel *pch;
1243 struct sk_buff *skb = ppp->xmit_pending;
1244
1245 if (!skb)
1246 return;
1247
1248 list = &ppp->channels;
1249 if (list_empty(list)) {
1250 /* nowhere to send the packet, just drop it */
1251 ppp->xmit_pending = NULL;
1252 kfree_skb(skb);
1253 return;
1254 }
1255
1256 if ((ppp->flags & SC_MULTILINK) == 0) {
1257 /* not doing multilink: send it down the first channel */
1258 list = list->next;
1259 pch = list_entry(list, struct channel, clist);
1260
1261 spin_lock_bh(&pch->downl);
1262 if (pch->chan) {
1263 if (pch->chan->ops->start_xmit(pch->chan, skb))
1264 ppp->xmit_pending = NULL;
1265 } else {
1266 /* channel got unregistered */
1267 kfree_skb(skb);
1268 ppp->xmit_pending = NULL;
1269 }
1270 spin_unlock_bh(&pch->downl);
1271 return;
1272 }
1273
1274 #ifdef CONFIG_PPP_MULTILINK
1275 /* Multilink: fragment the packet over as many links
1276 as can take the packet at the moment. */
1277 if (!ppp_mp_explode(ppp, skb))
1278 return;
1279 #endif /* CONFIG_PPP_MULTILINK */
1280
1281 ppp->xmit_pending = NULL;
1282 kfree_skb(skb);
1283 }
1284
1285 #ifdef CONFIG_PPP_MULTILINK
1286 static bool mp_protocol_compress __read_mostly = true;
1287 module_param(mp_protocol_compress, bool, S_IRUGO | S_IWUSR);
1288 MODULE_PARM_DESC(mp_protocol_compress,
1289 "compress protocol id in multilink fragments");
1290
1291 /*
1292 * Divide a packet to be transmitted into fragments and
1293 * send them out the individual links.
1294 */
1295 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1296 {
1297 int len, totlen;
1298 int i, bits, hdrlen, mtu;
1299 int flen;
1300 int navail, nfree, nzero;
1301 int nbigger;
1302 int totspeed;
1303 int totfree;
1304 unsigned char *p, *q;
1305 struct list_head *list;
1306 struct channel *pch;
1307 struct sk_buff *frag;
1308 struct ppp_channel *chan;
1309
1310 totspeed = 0; /*total bitrate of the bundle*/
1311 nfree = 0; /* # channels which have no packet already queued */
1312 navail = 0; /* total # of usable channels (not deregistered) */
1313 nzero = 0; /* number of channels with zero speed associated*/
1314 totfree = 0; /*total # of channels available and
1315 *having no queued packets before
1316 *starting the fragmentation*/
1317
1318 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1319 i = 0;
1320 list_for_each_entry(pch, &ppp->channels, clist) {
1321 if (pch->chan) {
1322 pch->avail = 1;
1323 navail++;
1324 pch->speed = pch->chan->speed;
1325 } else {
1326 pch->avail = 0;
1327 }
1328 if (pch->avail) {
1329 if (skb_queue_empty(&pch->file.xq) ||
1330 !pch->had_frag) {
1331 if (pch->speed == 0)
1332 nzero++;
1333 else
1334 totspeed += pch->speed;
1335
1336 pch->avail = 2;
1337 ++nfree;
1338 ++totfree;
1339 }
1340 if (!pch->had_frag && i < ppp->nxchan)
1341 ppp->nxchan = i;
1342 }
1343 ++i;
1344 }
1345 /*
1346 * Don't start sending this packet unless at least half of
1347 * the channels are free. This gives much better TCP
1348 * performance if we have a lot of channels.
1349 */
1350 if (nfree == 0 || nfree < navail / 2)
1351 return 0; /* can't take now, leave it in xmit_pending */
1352
1353 /* Do protocol field compression */
1354 p = skb->data;
1355 len = skb->len;
1356 if (*p == 0 && mp_protocol_compress) {
1357 ++p;
1358 --len;
1359 }
1360
1361 totlen = len;
1362 nbigger = len % nfree;
1363
1364 /* skip to the channel after the one we last used
1365 and start at that one */
1366 list = &ppp->channels;
1367 for (i = 0; i < ppp->nxchan; ++i) {
1368 list = list->next;
1369 if (list == &ppp->channels) {
1370 i = 0;
1371 break;
1372 }
1373 }
1374
1375 /* create a fragment for each channel */
1376 bits = B;
1377 while (len > 0) {
1378 list = list->next;
1379 if (list == &ppp->channels) {
1380 i = 0;
1381 continue;
1382 }
1383 pch = list_entry(list, struct channel, clist);
1384 ++i;
1385 if (!pch->avail)
1386 continue;
1387
1388 /*
1389 * Skip this channel if it has a fragment pending already and
1390 * we haven't given a fragment to all of the free channels.
1391 */
1392 if (pch->avail == 1) {
1393 if (nfree > 0)
1394 continue;
1395 } else {
1396 pch->avail = 1;
1397 }
1398
1399 /* check the channel's mtu and whether it is still attached. */
1400 spin_lock_bh(&pch->downl);
1401 if (pch->chan == NULL) {
1402 /* can't use this channel, it's being deregistered */
1403 if (pch->speed == 0)
1404 nzero--;
1405 else
1406 totspeed -= pch->speed;
1407
1408 spin_unlock_bh(&pch->downl);
1409 pch->avail = 0;
1410 totlen = len;
1411 totfree--;
1412 nfree--;
1413 if (--navail == 0)
1414 break;
1415 continue;
1416 }
1417
1418 /*
1419 *if the channel speed is not set divide
1420 *the packet evenly among the free channels;
1421 *otherwise divide it according to the speed
1422 *of the channel we are going to transmit on
1423 */
1424 flen = len;
1425 if (nfree > 0) {
1426 if (pch->speed == 0) {
1427 flen = len/nfree;
1428 if (nbigger > 0) {
1429 flen++;
1430 nbigger--;
1431 }
1432 } else {
1433 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
1434 ((totspeed*totfree)/pch->speed)) - hdrlen;
1435 if (nbigger > 0) {
1436 flen += ((totfree - nzero)*pch->speed)/totspeed;
1437 nbigger -= ((totfree - nzero)*pch->speed)/
1438 totspeed;
1439 }
1440 }
1441 nfree--;
1442 }
1443
1444 /*
1445 *check if we are on the last channel or
1446 *we exceded the lenght of the data to
1447 *fragment
1448 */
1449 if ((nfree <= 0) || (flen > len))
1450 flen = len;
1451 /*
1452 *it is not worth to tx on slow channels:
1453 *in that case from the resulting flen according to the
1454 *above formula will be equal or less than zero.
1455 *Skip the channel in this case
1456 */
1457 if (flen <= 0) {
1458 pch->avail = 2;
1459 spin_unlock_bh(&pch->downl);
1460 continue;
1461 }
1462
1463 mtu = pch->chan->mtu - hdrlen;
1464 if (mtu < 4)
1465 mtu = 4;
1466 if (flen > mtu)
1467 flen = mtu;
1468 if (flen == len)
1469 bits |= E;
1470 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1471 if (!frag)
1472 goto noskb;
1473 q = skb_put(frag, flen + hdrlen);
1474
1475 /* make the MP header */
1476 put_unaligned_be16(PPP_MP, q);
1477 if (ppp->flags & SC_MP_XSHORTSEQ) {
1478 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1479 q[3] = ppp->nxseq;
1480 } else {
1481 q[2] = bits;
1482 q[3] = ppp->nxseq >> 16;
1483 q[4] = ppp->nxseq >> 8;
1484 q[5] = ppp->nxseq;
1485 }
1486
1487 memcpy(q + hdrlen, p, flen);
1488
1489 /* try to send it down the channel */
1490 chan = pch->chan;
1491 if (!skb_queue_empty(&pch->file.xq) ||
1492 !chan->ops->start_xmit(chan, frag))
1493 skb_queue_tail(&pch->file.xq, frag);
1494 pch->had_frag = 1;
1495 p += flen;
1496 len -= flen;
1497 ++ppp->nxseq;
1498 bits = 0;
1499 spin_unlock_bh(&pch->downl);
1500 }
1501 ppp->nxchan = i;
1502
1503 return 1;
1504
1505 noskb:
1506 spin_unlock_bh(&pch->downl);
1507 if (ppp->debug & 1)
1508 printk(KERN_ERR "PPP: no memory (fragment)\n");
1509 ++ppp->dev->stats.tx_errors;
1510 ++ppp->nxseq;
1511 return 1; /* abandon the frame */
1512 }
1513 #endif /* CONFIG_PPP_MULTILINK */
1514
1515 /*
1516 * Try to send data out on a channel.
1517 */
1518 static void
1519 ppp_channel_push(struct channel *pch)
1520 {
1521 struct sk_buff *skb;
1522 struct ppp *ppp;
1523
1524 spin_lock_bh(&pch->downl);
1525 if (pch->chan) {
1526 while (!skb_queue_empty(&pch->file.xq)) {
1527 skb = skb_dequeue(&pch->file.xq);
1528 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1529 /* put the packet back and try again later */
1530 skb_queue_head(&pch->file.xq, skb);
1531 break;
1532 }
1533 }
1534 } else {
1535 /* channel got deregistered */
1536 skb_queue_purge(&pch->file.xq);
1537 }
1538 spin_unlock_bh(&pch->downl);
1539 /* see if there is anything from the attached unit to be sent */
1540 if (skb_queue_empty(&pch->file.xq)) {
1541 read_lock_bh(&pch->upl);
1542 ppp = pch->ppp;
1543 if (ppp)
1544 ppp_xmit_process(ppp);
1545 read_unlock_bh(&pch->upl);
1546 }
1547 }
1548
1549 /*
1550 * Receive-side routines.
1551 */
1552
1553 struct ppp_mp_skb_parm {
1554 u32 sequence;
1555 u8 BEbits;
1556 };
1557 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb))
1558
1559 static inline void
1560 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1561 {
1562 ppp_recv_lock(ppp);
1563 if (!ppp->closing)
1564 ppp_receive_frame(ppp, skb, pch);
1565 else
1566 kfree_skb(skb);
1567 ppp_recv_unlock(ppp);
1568 }
1569
1570 void
1571 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1572 {
1573 struct channel *pch = chan->ppp;
1574 int proto;
1575
1576 if (!pch) {
1577 kfree_skb(skb);
1578 return;
1579 }
1580
1581 read_lock_bh(&pch->upl);
1582 if (!pskb_may_pull(skb, 2)) {
1583 kfree_skb(skb);
1584 if (pch->ppp) {
1585 ++pch->ppp->dev->stats.rx_length_errors;
1586 ppp_receive_error(pch->ppp);
1587 }
1588 goto done;
1589 }
1590
1591 proto = PPP_PROTO(skb);
1592 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1593 /* put it on the channel queue */
1594 skb_queue_tail(&pch->file.rq, skb);
1595 /* drop old frames if queue too long */
1596 while (pch->file.rq.qlen > PPP_MAX_RQLEN &&
1597 (skb = skb_dequeue(&pch->file.rq)))
1598 kfree_skb(skb);
1599 wake_up_interruptible(&pch->file.rwait);
1600 } else {
1601 ppp_do_recv(pch->ppp, skb, pch);
1602 }
1603
1604 done:
1605 read_unlock_bh(&pch->upl);
1606 }
1607
1608 /* Put a 0-length skb in the receive queue as an error indication */
1609 void
1610 ppp_input_error(struct ppp_channel *chan, int code)
1611 {
1612 struct channel *pch = chan->ppp;
1613 struct sk_buff *skb;
1614
1615 if (!pch)
1616 return;
1617
1618 read_lock_bh(&pch->upl);
1619 if (pch->ppp) {
1620 skb = alloc_skb(0, GFP_ATOMIC);
1621 if (skb) {
1622 skb->len = 0; /* probably unnecessary */
1623 skb->cb[0] = code;
1624 ppp_do_recv(pch->ppp, skb, pch);
1625 }
1626 }
1627 read_unlock_bh(&pch->upl);
1628 }
1629
1630 /*
1631 * We come in here to process a received frame.
1632 * The receive side of the ppp unit is locked.
1633 */
1634 static void
1635 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1636 {
1637 /* note: a 0-length skb is used as an error indication */
1638 if (skb->len > 0) {
1639 #ifdef CONFIG_PPP_MULTILINK
1640 /* XXX do channel-level decompression here */
1641 if (PPP_PROTO(skb) == PPP_MP)
1642 ppp_receive_mp_frame(ppp, skb, pch);
1643 else
1644 #endif /* CONFIG_PPP_MULTILINK */
1645 ppp_receive_nonmp_frame(ppp, skb);
1646 } else {
1647 kfree_skb(skb);
1648 ppp_receive_error(ppp);
1649 }
1650 }
1651
1652 static void
1653 ppp_receive_error(struct ppp *ppp)
1654 {
1655 ++ppp->dev->stats.rx_errors;
1656 if (ppp->vj)
1657 slhc_toss(ppp->vj);
1658 }
1659
1660 static void
1661 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1662 {
1663 struct sk_buff *ns;
1664 int proto, len, npi;
1665
1666 /*
1667 * Decompress the frame, if compressed.
1668 * Note that some decompressors need to see uncompressed frames
1669 * that come in as well as compressed frames.
1670 */
1671 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) &&
1672 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1673 skb = ppp_decompress_frame(ppp, skb);
1674
1675 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1676 goto err;
1677
1678 proto = PPP_PROTO(skb);
1679 switch (proto) {
1680 case PPP_VJC_COMP:
1681 /* decompress VJ compressed packets */
1682 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1683 goto err;
1684
1685 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1686 /* copy to a new sk_buff with more tailroom */
1687 ns = dev_alloc_skb(skb->len + 128);
1688 if (!ns) {
1689 printk(KERN_ERR"PPP: no memory (VJ decomp)\n");
1690 goto err;
1691 }
1692 skb_reserve(ns, 2);
1693 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1694 kfree_skb(skb);
1695 skb = ns;
1696 }
1697 else
1698 skb->ip_summed = CHECKSUM_NONE;
1699
1700 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1701 if (len <= 0) {
1702 printk(KERN_DEBUG "PPP: VJ decompression error\n");
1703 goto err;
1704 }
1705 len += 2;
1706 if (len > skb->len)
1707 skb_put(skb, len - skb->len);
1708 else if (len < skb->len)
1709 skb_trim(skb, len);
1710 proto = PPP_IP;
1711 break;
1712
1713 case PPP_VJC_UNCOMP:
1714 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1715 goto err;
1716
1717 /* Until we fix the decompressor need to make sure
1718 * data portion is linear.
1719 */
1720 if (!pskb_may_pull(skb, skb->len))
1721 goto err;
1722
1723 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1724 printk(KERN_ERR "PPP: VJ uncompressed error\n");
1725 goto err;
1726 }
1727 proto = PPP_IP;
1728 break;
1729
1730 case PPP_CCP:
1731 ppp_ccp_peek(ppp, skb, 1);
1732 break;
1733 }
1734
1735 ++ppp->dev->stats.rx_packets;
1736 ppp->dev->stats.rx_bytes += skb->len - 2;
1737
1738 npi = proto_to_npindex(proto);
1739 if (npi < 0) {
1740 /* control or unknown frame - pass it to pppd */
1741 skb_queue_tail(&ppp->file.rq, skb);
1742 /* limit queue length by dropping old frames */
1743 while (ppp->file.rq.qlen > PPP_MAX_RQLEN &&
1744 (skb = skb_dequeue(&ppp->file.rq)))
1745 kfree_skb(skb);
1746 /* wake up any process polling or blocking on read */
1747 wake_up_interruptible(&ppp->file.rwait);
1748
1749 } else {
1750 /* network protocol frame - give it to the kernel */
1751
1752 #ifdef CONFIG_PPP_FILTER
1753 /* check if the packet passes the pass and active filters */
1754 /* the filter instructions are constructed assuming
1755 a four-byte PPP header on each packet */
1756 if (ppp->pass_filter || ppp->active_filter) {
1757 if (skb_cloned(skb) &&
1758 pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
1759 goto err;
1760
1761 *skb_push(skb, 2) = 0;
1762 if (ppp->pass_filter &&
1763 sk_run_filter(skb, ppp->pass_filter) == 0) {
1764 if (ppp->debug & 1)
1765 printk(KERN_DEBUG "PPP: inbound frame "
1766 "not passed\n");
1767 kfree_skb(skb);
1768 return;
1769 }
1770 if (!(ppp->active_filter &&
1771 sk_run_filter(skb, ppp->active_filter) == 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 PPP_MP_CB(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 ((PPP_MP_CB(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 PPP_MP_CB(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 *mskb = skb_peek(&ppp->mrq);
1938 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence))
1939 ppp->minseq = PPP_MP_CB(mskb)->sequence;
1940 }
1941
1942 /* Pull completed packets off the queue and receive them. */
1943 while ((skb = ppp_mp_reconstruct(ppp))) {
1944 if (pskb_may_pull(skb, 2))
1945 ppp_receive_nonmp_frame(ppp, skb);
1946 else {
1947 ++ppp->dev->stats.rx_length_errors;
1948 kfree_skb(skb);
1949 ppp_receive_error(ppp);
1950 }
1951 }
1952
1953 return;
1954
1955 err:
1956 kfree_skb(skb);
1957 ppp_receive_error(ppp);
1958 }
1959
1960 /*
1961 * Insert a fragment on the MP reconstruction queue.
1962 * The queue is ordered by increasing sequence number.
1963 */
1964 static void
1965 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
1966 {
1967 struct sk_buff *p;
1968 struct sk_buff_head *list = &ppp->mrq;
1969 u32 seq = PPP_MP_CB(skb)->sequence;
1970
1971 /* N.B. we don't need to lock the list lock because we have the
1972 ppp unit receive-side lock. */
1973 skb_queue_walk(list, p) {
1974 if (seq_before(seq, PPP_MP_CB(p)->sequence))
1975 break;
1976 }
1977 __skb_queue_before(list, p, skb);
1978 }
1979
1980 /*
1981 * Reconstruct a packet from the MP fragment queue.
1982 * We go through increasing sequence numbers until we find a
1983 * complete packet, or we get to the sequence number for a fragment
1984 * which hasn't arrived but might still do so.
1985 */
1986 static struct sk_buff *
1987 ppp_mp_reconstruct(struct ppp *ppp)
1988 {
1989 u32 seq = ppp->nextseq;
1990 u32 minseq = ppp->minseq;
1991 struct sk_buff_head *list = &ppp->mrq;
1992 struct sk_buff *p, *next;
1993 struct sk_buff *head, *tail;
1994 struct sk_buff *skb = NULL;
1995 int lost = 0, len = 0;
1996
1997 if (ppp->mrru == 0) /* do nothing until mrru is set */
1998 return NULL;
1999 head = list->next;
2000 tail = NULL;
2001 for (p = head; p != (struct sk_buff *) list; p = next) {
2002 next = p->next;
2003 if (seq_before(PPP_MP_CB(p)->sequence, seq)) {
2004 /* this can't happen, anyway ignore the skb */
2005 printk(KERN_ERR "ppp_mp_reconstruct bad seq %u < %u\n",
2006 PPP_MP_CB(p)->sequence, seq);
2007 head = next;
2008 continue;
2009 }
2010 if (PPP_MP_CB(p)->sequence != seq) {
2011 /* Fragment `seq' is missing. If it is after
2012 minseq, it might arrive later, so stop here. */
2013 if (seq_after(seq, minseq))
2014 break;
2015 /* Fragment `seq' is lost, keep going. */
2016 lost = 1;
2017 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)?
2018 minseq + 1: PPP_MP_CB(p)->sequence;
2019 next = p;
2020 continue;
2021 }
2022
2023 /*
2024 * At this point we know that all the fragments from
2025 * ppp->nextseq to seq are either present or lost.
2026 * Also, there are no complete packets in the queue
2027 * that have no missing fragments and end before this
2028 * fragment.
2029 */
2030
2031 /* B bit set indicates this fragment starts a packet */
2032 if (PPP_MP_CB(p)->BEbits & B) {
2033 head = p;
2034 lost = 0;
2035 len = 0;
2036 }
2037
2038 len += p->len;
2039
2040 /* Got a complete packet yet? */
2041 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) &&
2042 (PPP_MP_CB(head)->BEbits & B)) {
2043 if (len > ppp->mrru + 2) {
2044 ++ppp->dev->stats.rx_length_errors;
2045 printk(KERN_DEBUG "PPP: reconstructed packet"
2046 " is too long (%d)\n", len);
2047 } else if (p == head) {
2048 /* fragment is complete packet - reuse skb */
2049 tail = p;
2050 skb = skb_get(p);
2051 break;
2052 } else if ((skb = dev_alloc_skb(len)) == NULL) {
2053 ++ppp->dev->stats.rx_missed_errors;
2054 printk(KERN_DEBUG "PPP: no memory for "
2055 "reconstructed packet");
2056 } else {
2057 tail = p;
2058 break;
2059 }
2060 ppp->nextseq = seq + 1;
2061 }
2062
2063 /*
2064 * If this is the ending fragment of a packet,
2065 * and we haven't found a complete valid packet yet,
2066 * we can discard up to and including this fragment.
2067 */
2068 if (PPP_MP_CB(p)->BEbits & E)
2069 head = next;
2070
2071 ++seq;
2072 }
2073
2074 /* If we have a complete packet, copy it all into one skb. */
2075 if (tail != NULL) {
2076 /* If we have discarded any fragments,
2077 signal a receive error. */
2078 if (PPP_MP_CB(head)->sequence != ppp->nextseq) {
2079 if (ppp->debug & 1)
2080 printk(KERN_DEBUG " missed pkts %u..%u\n",
2081 ppp->nextseq,
2082 PPP_MP_CB(head)->sequence-1);
2083 ++ppp->dev->stats.rx_dropped;
2084 ppp_receive_error(ppp);
2085 }
2086
2087 if (head != tail)
2088 /* copy to a single skb */
2089 for (p = head; p != tail->next; p = p->next)
2090 skb_copy_bits(p, 0, skb_put(skb, p->len), p->len);
2091 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1;
2092 head = tail->next;
2093 }
2094
2095 /* Discard all the skbuffs that we have copied the data out of
2096 or that we can't use. */
2097 while ((p = list->next) != head) {
2098 __skb_unlink(p, list);
2099 kfree_skb(p);
2100 }
2101
2102 return skb;
2103 }
2104 #endif /* CONFIG_PPP_MULTILINK */
2105
2106 /*
2107 * Channel interface.
2108 */
2109
2110 /* Create a new, unattached ppp channel. */
2111 int ppp_register_channel(struct ppp_channel *chan)
2112 {
2113 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2114 }
2115
2116 /* Create a new, unattached ppp channel for specified net. */
2117 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
2118 {
2119 struct channel *pch;
2120 struct ppp_net *pn;
2121
2122 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2123 if (!pch)
2124 return -ENOMEM;
2125
2126 pn = ppp_pernet(net);
2127
2128 pch->ppp = NULL;
2129 pch->chan = chan;
2130 pch->chan_net = net;
2131 chan->ppp = pch;
2132 init_ppp_file(&pch->file, CHANNEL);
2133 pch->file.hdrlen = chan->hdrlen;
2134 #ifdef CONFIG_PPP_MULTILINK
2135 pch->lastseq = -1;
2136 #endif /* CONFIG_PPP_MULTILINK */
2137 init_rwsem(&pch->chan_sem);
2138 spin_lock_init(&pch->downl);
2139 rwlock_init(&pch->upl);
2140
2141 spin_lock_bh(&pn->all_channels_lock);
2142 pch->file.index = ++pn->last_channel_index;
2143 list_add(&pch->list, &pn->new_channels);
2144 atomic_inc(&channel_count);
2145 spin_unlock_bh(&pn->all_channels_lock);
2146
2147 return 0;
2148 }
2149
2150 /*
2151 * Return the index of a channel.
2152 */
2153 int ppp_channel_index(struct ppp_channel *chan)
2154 {
2155 struct channel *pch = chan->ppp;
2156
2157 if (pch)
2158 return pch->file.index;
2159 return -1;
2160 }
2161
2162 /*
2163 * Return the PPP unit number to which a channel is connected.
2164 */
2165 int ppp_unit_number(struct ppp_channel *chan)
2166 {
2167 struct channel *pch = chan->ppp;
2168 int unit = -1;
2169
2170 if (pch) {
2171 read_lock_bh(&pch->upl);
2172 if (pch->ppp)
2173 unit = pch->ppp->file.index;
2174 read_unlock_bh(&pch->upl);
2175 }
2176 return unit;
2177 }
2178
2179 /*
2180 * Return the PPP device interface name of a channel.
2181 */
2182 char *ppp_dev_name(struct ppp_channel *chan)
2183 {
2184 struct channel *pch = chan->ppp;
2185 char *name = NULL;
2186
2187 if (pch) {
2188 read_lock_bh(&pch->upl);
2189 if (pch->ppp && pch->ppp->dev)
2190 name = pch->ppp->dev->name;
2191 read_unlock_bh(&pch->upl);
2192 }
2193 return name;
2194 }
2195
2196
2197 /*
2198 * Disconnect a channel from the generic layer.
2199 * This must be called in process context.
2200 */
2201 void
2202 ppp_unregister_channel(struct ppp_channel *chan)
2203 {
2204 struct channel *pch = chan->ppp;
2205 struct ppp_net *pn;
2206
2207 if (!pch)
2208 return; /* should never happen */
2209
2210 chan->ppp = NULL;
2211
2212 /*
2213 * This ensures that we have returned from any calls into the
2214 * the channel's start_xmit or ioctl routine before we proceed.
2215 */
2216 down_write(&pch->chan_sem);
2217 spin_lock_bh(&pch->downl);
2218 pch->chan = NULL;
2219 spin_unlock_bh(&pch->downl);
2220 up_write(&pch->chan_sem);
2221 ppp_disconnect_channel(pch);
2222
2223 pn = ppp_pernet(pch->chan_net);
2224 spin_lock_bh(&pn->all_channels_lock);
2225 list_del(&pch->list);
2226 spin_unlock_bh(&pn->all_channels_lock);
2227
2228 pch->file.dead = 1;
2229 wake_up_interruptible(&pch->file.rwait);
2230 if (atomic_dec_and_test(&pch->file.refcnt))
2231 ppp_destroy_channel(pch);
2232 }
2233
2234 /*
2235 * Callback from a channel when it can accept more to transmit.
2236 * This should be called at BH/softirq level, not interrupt level.
2237 */
2238 void
2239 ppp_output_wakeup(struct ppp_channel *chan)
2240 {
2241 struct channel *pch = chan->ppp;
2242
2243 if (!pch)
2244 return;
2245 ppp_channel_push(pch);
2246 }
2247
2248 /*
2249 * Compression control.
2250 */
2251
2252 /* Process the PPPIOCSCOMPRESS ioctl. */
2253 static int
2254 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2255 {
2256 int err;
2257 struct compressor *cp, *ocomp;
2258 struct ppp_option_data data;
2259 void *state, *ostate;
2260 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2261
2262 err = -EFAULT;
2263 if (copy_from_user(&data, (void __user *) arg, sizeof(data)) ||
2264 (data.length <= CCP_MAX_OPTION_LENGTH &&
2265 copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2266 goto out;
2267 err = -EINVAL;
2268 if (data.length > CCP_MAX_OPTION_LENGTH ||
2269 ccp_option[1] < 2 || ccp_option[1] > data.length)
2270 goto out;
2271
2272 cp = try_then_request_module(
2273 find_compressor(ccp_option[0]),
2274 "ppp-compress-%d", ccp_option[0]);
2275 if (!cp)
2276 goto out;
2277
2278 err = -ENOBUFS;
2279 if (data.transmit) {
2280 state = cp->comp_alloc(ccp_option, data.length);
2281 if (state) {
2282 ppp_xmit_lock(ppp);
2283 ppp->xstate &= ~SC_COMP_RUN;
2284 ocomp = ppp->xcomp;
2285 ostate = ppp->xc_state;
2286 ppp->xcomp = cp;
2287 ppp->xc_state = state;
2288 ppp_xmit_unlock(ppp);
2289 if (ostate) {
2290 ocomp->comp_free(ostate);
2291 module_put(ocomp->owner);
2292 }
2293 err = 0;
2294 } else
2295 module_put(cp->owner);
2296
2297 } else {
2298 state = cp->decomp_alloc(ccp_option, data.length);
2299 if (state) {
2300 ppp_recv_lock(ppp);
2301 ppp->rstate &= ~SC_DECOMP_RUN;
2302 ocomp = ppp->rcomp;
2303 ostate = ppp->rc_state;
2304 ppp->rcomp = cp;
2305 ppp->rc_state = state;
2306 ppp_recv_unlock(ppp);
2307 if (ostate) {
2308 ocomp->decomp_free(ostate);
2309 module_put(ocomp->owner);
2310 }
2311 err = 0;
2312 } else
2313 module_put(cp->owner);
2314 }
2315
2316 out:
2317 return err;
2318 }
2319
2320 /*
2321 * Look at a CCP packet and update our state accordingly.
2322 * We assume the caller has the xmit or recv path locked.
2323 */
2324 static void
2325 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2326 {
2327 unsigned char *dp;
2328 int len;
2329
2330 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2331 return; /* no header */
2332 dp = skb->data + 2;
2333
2334 switch (CCP_CODE(dp)) {
2335 case CCP_CONFREQ:
2336
2337 /* A ConfReq starts negotiation of compression
2338 * in one direction of transmission,
2339 * and hence brings it down...but which way?
2340 *
2341 * Remember:
2342 * A ConfReq indicates what the sender would like to receive
2343 */
2344 if(inbound)
2345 /* He is proposing what I should send */
2346 ppp->xstate &= ~SC_COMP_RUN;
2347 else
2348 /* I am proposing to what he should send */
2349 ppp->rstate &= ~SC_DECOMP_RUN;
2350
2351 break;
2352
2353 case CCP_TERMREQ:
2354 case CCP_TERMACK:
2355 /*
2356 * CCP is going down, both directions of transmission
2357 */
2358 ppp->rstate &= ~SC_DECOMP_RUN;
2359 ppp->xstate &= ~SC_COMP_RUN;
2360 break;
2361
2362 case CCP_CONFACK:
2363 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2364 break;
2365 len = CCP_LENGTH(dp);
2366 if (!pskb_may_pull(skb, len + 2))
2367 return; /* too short */
2368 dp += CCP_HDRLEN;
2369 len -= CCP_HDRLEN;
2370 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2371 break;
2372 if (inbound) {
2373 /* we will start receiving compressed packets */
2374 if (!ppp->rc_state)
2375 break;
2376 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2377 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2378 ppp->rstate |= SC_DECOMP_RUN;
2379 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2380 }
2381 } else {
2382 /* we will soon start sending compressed packets */
2383 if (!ppp->xc_state)
2384 break;
2385 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2386 ppp->file.index, 0, ppp->debug))
2387 ppp->xstate |= SC_COMP_RUN;
2388 }
2389 break;
2390
2391 case CCP_RESETACK:
2392 /* reset the [de]compressor */
2393 if ((ppp->flags & SC_CCP_UP) == 0)
2394 break;
2395 if (inbound) {
2396 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2397 ppp->rcomp->decomp_reset(ppp->rc_state);
2398 ppp->rstate &= ~SC_DC_ERROR;
2399 }
2400 } else {
2401 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2402 ppp->xcomp->comp_reset(ppp->xc_state);
2403 }
2404 break;
2405 }
2406 }
2407
2408 /* Free up compression resources. */
2409 static void
2410 ppp_ccp_closed(struct ppp *ppp)
2411 {
2412 void *xstate, *rstate;
2413 struct compressor *xcomp, *rcomp;
2414
2415 ppp_lock(ppp);
2416 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2417 ppp->xstate = 0;
2418 xcomp = ppp->xcomp;
2419 xstate = ppp->xc_state;
2420 ppp->xc_state = NULL;
2421 ppp->rstate = 0;
2422 rcomp = ppp->rcomp;
2423 rstate = ppp->rc_state;
2424 ppp->rc_state = NULL;
2425 ppp_unlock(ppp);
2426
2427 if (xstate) {
2428 xcomp->comp_free(xstate);
2429 module_put(xcomp->owner);
2430 }
2431 if (rstate) {
2432 rcomp->decomp_free(rstate);
2433 module_put(rcomp->owner);
2434 }
2435 }
2436
2437 /* List of compressors. */
2438 static LIST_HEAD(compressor_list);
2439 static DEFINE_SPINLOCK(compressor_list_lock);
2440
2441 struct compressor_entry {
2442 struct list_head list;
2443 struct compressor *comp;
2444 };
2445
2446 static struct compressor_entry *
2447 find_comp_entry(int proto)
2448 {
2449 struct compressor_entry *ce;
2450
2451 list_for_each_entry(ce, &compressor_list, list) {
2452 if (ce->comp->compress_proto == proto)
2453 return ce;
2454 }
2455 return NULL;
2456 }
2457
2458 /* Register a compressor */
2459 int
2460 ppp_register_compressor(struct compressor *cp)
2461 {
2462 struct compressor_entry *ce;
2463 int ret;
2464 spin_lock(&compressor_list_lock);
2465 ret = -EEXIST;
2466 if (find_comp_entry(cp->compress_proto))
2467 goto out;
2468 ret = -ENOMEM;
2469 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2470 if (!ce)
2471 goto out;
2472 ret = 0;
2473 ce->comp = cp;
2474 list_add(&ce->list, &compressor_list);
2475 out:
2476 spin_unlock(&compressor_list_lock);
2477 return ret;
2478 }
2479
2480 /* Unregister a compressor */
2481 void
2482 ppp_unregister_compressor(struct compressor *cp)
2483 {
2484 struct compressor_entry *ce;
2485
2486 spin_lock(&compressor_list_lock);
2487 ce = find_comp_entry(cp->compress_proto);
2488 if (ce && ce->comp == cp) {
2489 list_del(&ce->list);
2490 kfree(ce);
2491 }
2492 spin_unlock(&compressor_list_lock);
2493 }
2494
2495 /* Find a compressor. */
2496 static struct compressor *
2497 find_compressor(int type)
2498 {
2499 struct compressor_entry *ce;
2500 struct compressor *cp = NULL;
2501
2502 spin_lock(&compressor_list_lock);
2503 ce = find_comp_entry(type);
2504 if (ce) {
2505 cp = ce->comp;
2506 if (!try_module_get(cp->owner))
2507 cp = NULL;
2508 }
2509 spin_unlock(&compressor_list_lock);
2510 return cp;
2511 }
2512
2513 /*
2514 * Miscelleneous stuff.
2515 */
2516
2517 static void
2518 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2519 {
2520 struct slcompress *vj = ppp->vj;
2521
2522 memset(st, 0, sizeof(*st));
2523 st->p.ppp_ipackets = ppp->dev->stats.rx_packets;
2524 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2525 st->p.ppp_ibytes = ppp->dev->stats.rx_bytes;
2526 st->p.ppp_opackets = ppp->dev->stats.tx_packets;
2527 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2528 st->p.ppp_obytes = ppp->dev->stats.tx_bytes;
2529 if (!vj)
2530 return;
2531 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2532 st->vj.vjs_compressed = vj->sls_o_compressed;
2533 st->vj.vjs_searches = vj->sls_o_searches;
2534 st->vj.vjs_misses = vj->sls_o_misses;
2535 st->vj.vjs_errorin = vj->sls_i_error;
2536 st->vj.vjs_tossed = vj->sls_i_tossed;
2537 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2538 st->vj.vjs_compressedin = vj->sls_i_compressed;
2539 }
2540
2541 /*
2542 * Stuff for handling the lists of ppp units and channels
2543 * and for initialization.
2544 */
2545
2546 /*
2547 * Create a new ppp interface unit. Fails if it can't allocate memory
2548 * or if there is already a unit with the requested number.
2549 * unit == -1 means allocate a new number.
2550 */
2551 static struct ppp *
2552 ppp_create_interface(struct net *net, int unit, int *retp)
2553 {
2554 struct ppp *ppp;
2555 struct ppp_net *pn;
2556 struct net_device *dev = NULL;
2557 int ret = -ENOMEM;
2558 int i;
2559
2560 dev = alloc_netdev(sizeof(struct ppp), "", ppp_setup);
2561 if (!dev)
2562 goto out1;
2563
2564 pn = ppp_pernet(net);
2565
2566 ppp = netdev_priv(dev);
2567 ppp->dev = dev;
2568 ppp->mru = PPP_MRU;
2569 init_ppp_file(&ppp->file, INTERFACE);
2570 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2571 for (i = 0; i < NUM_NP; ++i)
2572 ppp->npmode[i] = NPMODE_PASS;
2573 INIT_LIST_HEAD(&ppp->channels);
2574 spin_lock_init(&ppp->rlock);
2575 spin_lock_init(&ppp->wlock);
2576 #ifdef CONFIG_PPP_MULTILINK
2577 ppp->minseq = -1;
2578 skb_queue_head_init(&ppp->mrq);
2579 #endif /* CONFIG_PPP_MULTILINK */
2580
2581 /*
2582 * drum roll: don't forget to set
2583 * the net device is belong to
2584 */
2585 dev_net_set(dev, net);
2586
2587 mutex_lock(&pn->all_ppp_mutex);
2588
2589 if (unit < 0) {
2590 unit = unit_get(&pn->units_idr, ppp);
2591 if (unit < 0) {
2592 ret = unit;
2593 goto out2;
2594 }
2595 } else {
2596 ret = -EEXIST;
2597 if (unit_find(&pn->units_idr, unit))
2598 goto out2; /* unit already exists */
2599 /*
2600 * if caller need a specified unit number
2601 * lets try to satisfy him, otherwise --
2602 * he should better ask us for new unit number
2603 *
2604 * NOTE: yes I know that returning EEXIST it's not
2605 * fair but at least pppd will ask us to allocate
2606 * new unit in this case so user is happy :)
2607 */
2608 unit = unit_set(&pn->units_idr, ppp, unit);
2609 if (unit < 0)
2610 goto out2;
2611 }
2612
2613 /* Initialize the new ppp unit */
2614 ppp->file.index = unit;
2615 sprintf(dev->name, "ppp%d", unit);
2616
2617 ret = register_netdev(dev);
2618 if (ret != 0) {
2619 unit_put(&pn->units_idr, unit);
2620 printk(KERN_ERR "PPP: couldn't register device %s (%d)\n",
2621 dev->name, ret);
2622 goto out2;
2623 }
2624
2625 ppp->ppp_net = net;
2626
2627 atomic_inc(&ppp_unit_count);
2628 mutex_unlock(&pn->all_ppp_mutex);
2629
2630 *retp = 0;
2631 return ppp;
2632
2633 out2:
2634 mutex_unlock(&pn->all_ppp_mutex);
2635 free_netdev(dev);
2636 out1:
2637 *retp = ret;
2638 return NULL;
2639 }
2640
2641 /*
2642 * Initialize a ppp_file structure.
2643 */
2644 static void
2645 init_ppp_file(struct ppp_file *pf, int kind)
2646 {
2647 pf->kind = kind;
2648 skb_queue_head_init(&pf->xq);
2649 skb_queue_head_init(&pf->rq);
2650 atomic_set(&pf->refcnt, 1);
2651 init_waitqueue_head(&pf->rwait);
2652 }
2653
2654 /*
2655 * Take down a ppp interface unit - called when the owning file
2656 * (the one that created the unit) is closed or detached.
2657 */
2658 static void ppp_shutdown_interface(struct ppp *ppp)
2659 {
2660 struct ppp_net *pn;
2661
2662 pn = ppp_pernet(ppp->ppp_net);
2663 mutex_lock(&pn->all_ppp_mutex);
2664
2665 /* This will call dev_close() for us. */
2666 ppp_lock(ppp);
2667 if (!ppp->closing) {
2668 ppp->closing = 1;
2669 ppp_unlock(ppp);
2670 unregister_netdev(ppp->dev);
2671 unit_put(&pn->units_idr, ppp->file.index);
2672 } else
2673 ppp_unlock(ppp);
2674
2675 ppp->file.dead = 1;
2676 ppp->owner = NULL;
2677 wake_up_interruptible(&ppp->file.rwait);
2678
2679 mutex_unlock(&pn->all_ppp_mutex);
2680 }
2681
2682 /*
2683 * Free the memory used by a ppp unit. This is only called once
2684 * there are no channels connected to the unit and no file structs
2685 * that reference the unit.
2686 */
2687 static void ppp_destroy_interface(struct ppp *ppp)
2688 {
2689 atomic_dec(&ppp_unit_count);
2690
2691 if (!ppp->file.dead || ppp->n_channels) {
2692 /* "can't happen" */
2693 printk(KERN_ERR "ppp: destroying ppp struct %p but dead=%d "
2694 "n_channels=%d !\n", ppp, ppp->file.dead,
2695 ppp->n_channels);
2696 return;
2697 }
2698
2699 ppp_ccp_closed(ppp);
2700 if (ppp->vj) {
2701 slhc_free(ppp->vj);
2702 ppp->vj = NULL;
2703 }
2704 skb_queue_purge(&ppp->file.xq);
2705 skb_queue_purge(&ppp->file.rq);
2706 #ifdef CONFIG_PPP_MULTILINK
2707 skb_queue_purge(&ppp->mrq);
2708 #endif /* CONFIG_PPP_MULTILINK */
2709 #ifdef CONFIG_PPP_FILTER
2710 kfree(ppp->pass_filter);
2711 ppp->pass_filter = NULL;
2712 kfree(ppp->active_filter);
2713 ppp->active_filter = NULL;
2714 #endif /* CONFIG_PPP_FILTER */
2715
2716 kfree_skb(ppp->xmit_pending);
2717
2718 free_netdev(ppp->dev);
2719 }
2720
2721 /*
2722 * Locate an existing ppp unit.
2723 * The caller should have locked the all_ppp_mutex.
2724 */
2725 static struct ppp *
2726 ppp_find_unit(struct ppp_net *pn, int unit)
2727 {
2728 return unit_find(&pn->units_idr, unit);
2729 }
2730
2731 /*
2732 * Locate an existing ppp channel.
2733 * The caller should have locked the all_channels_lock.
2734 * First we look in the new_channels list, then in the
2735 * all_channels list. If found in the new_channels list,
2736 * we move it to the all_channels list. This is for speed
2737 * when we have a lot of channels in use.
2738 */
2739 static struct channel *
2740 ppp_find_channel(struct ppp_net *pn, int unit)
2741 {
2742 struct channel *pch;
2743
2744 list_for_each_entry(pch, &pn->new_channels, list) {
2745 if (pch->file.index == unit) {
2746 list_move(&pch->list, &pn->all_channels);
2747 return pch;
2748 }
2749 }
2750
2751 list_for_each_entry(pch, &pn->all_channels, list) {
2752 if (pch->file.index == unit)
2753 return pch;
2754 }
2755
2756 return NULL;
2757 }
2758
2759 /*
2760 * Connect a PPP channel to a PPP interface unit.
2761 */
2762 static int
2763 ppp_connect_channel(struct channel *pch, int unit)
2764 {
2765 struct ppp *ppp;
2766 struct ppp_net *pn;
2767 int ret = -ENXIO;
2768 int hdrlen;
2769
2770 pn = ppp_pernet(pch->chan_net);
2771
2772 mutex_lock(&pn->all_ppp_mutex);
2773 ppp = ppp_find_unit(pn, unit);
2774 if (!ppp)
2775 goto out;
2776 write_lock_bh(&pch->upl);
2777 ret = -EINVAL;
2778 if (pch->ppp)
2779 goto outl;
2780
2781 ppp_lock(ppp);
2782 if (pch->file.hdrlen > ppp->file.hdrlen)
2783 ppp->file.hdrlen = pch->file.hdrlen;
2784 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2785 if (hdrlen > ppp->dev->hard_header_len)
2786 ppp->dev->hard_header_len = hdrlen;
2787 list_add_tail(&pch->clist, &ppp->channels);
2788 ++ppp->n_channels;
2789 pch->ppp = ppp;
2790 atomic_inc(&ppp->file.refcnt);
2791 ppp_unlock(ppp);
2792 ret = 0;
2793
2794 outl:
2795 write_unlock_bh(&pch->upl);
2796 out:
2797 mutex_unlock(&pn->all_ppp_mutex);
2798 return ret;
2799 }
2800
2801 /*
2802 * Disconnect a channel from its ppp unit.
2803 */
2804 static int
2805 ppp_disconnect_channel(struct channel *pch)
2806 {
2807 struct ppp *ppp;
2808 int err = -EINVAL;
2809
2810 write_lock_bh(&pch->upl);
2811 ppp = pch->ppp;
2812 pch->ppp = NULL;
2813 write_unlock_bh(&pch->upl);
2814 if (ppp) {
2815 /* remove it from the ppp unit's list */
2816 ppp_lock(ppp);
2817 list_del(&pch->clist);
2818 if (--ppp->n_channels == 0)
2819 wake_up_interruptible(&ppp->file.rwait);
2820 ppp_unlock(ppp);
2821 if (atomic_dec_and_test(&ppp->file.refcnt))
2822 ppp_destroy_interface(ppp);
2823 err = 0;
2824 }
2825 return err;
2826 }
2827
2828 /*
2829 * Free up the resources used by a ppp channel.
2830 */
2831 static void ppp_destroy_channel(struct channel *pch)
2832 {
2833 atomic_dec(&channel_count);
2834
2835 if (!pch->file.dead) {
2836 /* "can't happen" */
2837 printk(KERN_ERR "ppp: destroying undead channel %p !\n",
2838 pch);
2839 return;
2840 }
2841 skb_queue_purge(&pch->file.xq);
2842 skb_queue_purge(&pch->file.rq);
2843 kfree(pch);
2844 }
2845
2846 static void __exit ppp_cleanup(void)
2847 {
2848 /* should never happen */
2849 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2850 printk(KERN_ERR "PPP: removing module but units remain!\n");
2851 unregister_chrdev(PPP_MAJOR, "ppp");
2852 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
2853 class_destroy(ppp_class);
2854 unregister_pernet_device(&ppp_net_ops);
2855 }
2856
2857 /*
2858 * Units handling. Caller must protect concurrent access
2859 * by holding all_ppp_mutex
2860 */
2861
2862 static int __unit_alloc(struct idr *p, void *ptr, int n)
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, n, &unit);
2873 if (err < 0) {
2874 if (err == -EAGAIN)
2875 goto again;
2876 return err;
2877 }
2878
2879 return unit;
2880 }
2881
2882 /* associate pointer with specified number */
2883 static int unit_set(struct idr *p, void *ptr, int n)
2884 {
2885 int unit;
2886
2887 unit = __unit_alloc(p, ptr, n);
2888 if (unit < 0)
2889 return unit;
2890 else if (unit != n) {
2891 idr_remove(p, unit);
2892 return -EINVAL;
2893 }
2894
2895 return unit;
2896 }
2897
2898 /* get new free unit number and associate pointer with it */
2899 static int unit_get(struct idr *p, void *ptr)
2900 {
2901 return __unit_alloc(p, ptr, 0);
2902 }
2903
2904 /* put unit number back to a pool */
2905 static void unit_put(struct idr *p, int n)
2906 {
2907 idr_remove(p, n);
2908 }
2909
2910 /* get pointer associated with the number */
2911 static void *unit_find(struct idr *p, int n)
2912 {
2913 return idr_find(p, n);
2914 }
2915
2916 /* Module/initialization stuff */
2917
2918 module_init(ppp_init);
2919 module_exit(ppp_cleanup);
2920
2921 EXPORT_SYMBOL(ppp_register_net_channel);
2922 EXPORT_SYMBOL(ppp_register_channel);
2923 EXPORT_SYMBOL(ppp_unregister_channel);
2924 EXPORT_SYMBOL(ppp_channel_index);
2925 EXPORT_SYMBOL(ppp_unit_number);
2926 EXPORT_SYMBOL(ppp_dev_name);
2927 EXPORT_SYMBOL(ppp_input);
2928 EXPORT_SYMBOL(ppp_input_error);
2929 EXPORT_SYMBOL(ppp_output_wakeup);
2930 EXPORT_SYMBOL(ppp_register_compressor);
2931 EXPORT_SYMBOL(ppp_unregister_compressor);
2932 MODULE_LICENSE("GPL");
2933 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
2934 MODULE_ALIAS("devname:ppp");
linux-next