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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
[linux-btrfs-devel.git] / drivers / net / ppp / ppp_generic.c
blobedfa15d2e79501deabe2e3c3481378d1a8ac7bb7
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 <linux/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 pr_warn("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 pr_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 netdev_err(ppp->dev,
708 "PPP: no memory (VJ compressor)\n");
709 err = -ENOMEM;
710 break;
711 }
712 ppp_lock(ppp);
713 if (ppp->vj)
714 slhc_free(ppp->vj);
715 ppp->vj = vj;
716 ppp_unlock(ppp);
717 err = 0;
718 break;
719
720 case PPPIOCGNPMODE:
721 case PPPIOCSNPMODE:
722 if (copy_from_user(&npi, argp, sizeof(npi)))
723 break;
724 err = proto_to_npindex(npi.protocol);
725 if (err < 0)
726 break;
727 i = err;
728 if (cmd == PPPIOCGNPMODE) {
729 err = -EFAULT;
730 npi.mode = ppp->npmode[i];
731 if (copy_to_user(argp, &npi, sizeof(npi)))
732 break;
733 } else {
734 ppp->npmode[i] = npi.mode;
735 /* we may be able to transmit more packets now (??) */
736 netif_wake_queue(ppp->dev);
737 }
738 err = 0;
739 break;
740
741 #ifdef CONFIG_PPP_FILTER
742 case PPPIOCSPASS:
743 {
744 struct sock_filter *code;
745 err = get_filter(argp, &code);
746 if (err >= 0) {
747 ppp_lock(ppp);
748 kfree(ppp->pass_filter);
749 ppp->pass_filter = code;
750 ppp->pass_len = err;
751 ppp_unlock(ppp);
752 err = 0;
753 }
754 break;
755 }
756 case PPPIOCSACTIVE:
757 {
758 struct sock_filter *code;
759 err = get_filter(argp, &code);
760 if (err >= 0) {
761 ppp_lock(ppp);
762 kfree(ppp->active_filter);
763 ppp->active_filter = code;
764 ppp->active_len = err;
765 ppp_unlock(ppp);
766 err = 0;
767 }
768 break;
769 }
770 #endif /* CONFIG_PPP_FILTER */
771
772 #ifdef CONFIG_PPP_MULTILINK
773 case PPPIOCSMRRU:
774 if (get_user(val, p))
775 break;
776 ppp_recv_lock(ppp);
777 ppp->mrru = val;
778 ppp_recv_unlock(ppp);
779 err = 0;
780 break;
781 #endif /* CONFIG_PPP_MULTILINK */
782
783 default:
784 err = -ENOTTY;
785 }
786 mutex_unlock(&ppp_mutex);
787 return err;
788 }
789
790 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
791 struct file *file, unsigned int cmd, unsigned long arg)
792 {
793 int unit, err = -EFAULT;
794 struct ppp *ppp;
795 struct channel *chan;
796 struct ppp_net *pn;
797 int __user *p = (int __user *)arg;
798
799 mutex_lock(&ppp_mutex);
800 switch (cmd) {
801 case PPPIOCNEWUNIT:
802 /* Create a new ppp unit */
803 if (get_user(unit, p))
804 break;
805 ppp = ppp_create_interface(net, unit, &err);
806 if (!ppp)
807 break;
808 file->private_data = &ppp->file;
809 ppp->owner = file;
810 err = -EFAULT;
811 if (put_user(ppp->file.index, p))
812 break;
813 err = 0;
814 break;
815
816 case PPPIOCATTACH:
817 /* Attach to an existing ppp unit */
818 if (get_user(unit, p))
819 break;
820 err = -ENXIO;
821 pn = ppp_pernet(net);
822 mutex_lock(&pn->all_ppp_mutex);
823 ppp = ppp_find_unit(pn, unit);
824 if (ppp) {
825 atomic_inc(&ppp->file.refcnt);
826 file->private_data = &ppp->file;
827 err = 0;
828 }
829 mutex_unlock(&pn->all_ppp_mutex);
830 break;
831
832 case PPPIOCATTCHAN:
833 if (get_user(unit, p))
834 break;
835 err = -ENXIO;
836 pn = ppp_pernet(net);
837 spin_lock_bh(&pn->all_channels_lock);
838 chan = ppp_find_channel(pn, unit);
839 if (chan) {
840 atomic_inc(&chan->file.refcnt);
841 file->private_data = &chan->file;
842 err = 0;
843 }
844 spin_unlock_bh(&pn->all_channels_lock);
845 break;
846
847 default:
848 err = -ENOTTY;
849 }
850 mutex_unlock(&ppp_mutex);
851 return err;
852 }
853
854 static const struct file_operations ppp_device_fops = {
855 .owner = THIS_MODULE,
856 .read = ppp_read,
857 .write = ppp_write,
858 .poll = ppp_poll,
859 .unlocked_ioctl = ppp_ioctl,
860 .open = ppp_open,
861 .release = ppp_release,
862 .llseek = noop_llseek,
863 };
864
865 static __net_init int ppp_init_net(struct net *net)
866 {
867 struct ppp_net *pn = net_generic(net, ppp_net_id);
868
869 idr_init(&pn->units_idr);
870 mutex_init(&pn->all_ppp_mutex);
871
872 INIT_LIST_HEAD(&pn->all_channels);
873 INIT_LIST_HEAD(&pn->new_channels);
874
875 spin_lock_init(&pn->all_channels_lock);
876
877 return 0;
878 }
879
880 static __net_exit void ppp_exit_net(struct net *net)
881 {
882 struct ppp_net *pn = net_generic(net, ppp_net_id);
883
884 idr_destroy(&pn->units_idr);
885 }
886
887 static struct pernet_operations ppp_net_ops = {
888 .init = ppp_init_net,
889 .exit = ppp_exit_net,
890 .id = &ppp_net_id,
891 .size = sizeof(struct ppp_net),
892 };
893
894 #define PPP_MAJOR 108
895
896 /* Called at boot time if ppp is compiled into the kernel,
897 or at module load time (from init_module) if compiled as a module. */
898 static int __init ppp_init(void)
899 {
900 int err;
901
902 pr_info("PPP generic driver version " PPP_VERSION "\n");
903
904 err = register_pernet_device(&ppp_net_ops);
905 if (err) {
906 pr_err("failed to register PPP pernet device (%d)\n", err);
907 goto out;
908 }
909
910 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
911 if (err) {
912 pr_err("failed to register PPP device (%d)\n", err);
913 goto out_net;
914 }
915
916 ppp_class = class_create(THIS_MODULE, "ppp");
917 if (IS_ERR(ppp_class)) {
918 err = PTR_ERR(ppp_class);
919 goto out_chrdev;
920 }
921
922 /* not a big deal if we fail here :-) */
923 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
924
925 return 0;
926
927 out_chrdev:
928 unregister_chrdev(PPP_MAJOR, "ppp");
929 out_net:
930 unregister_pernet_device(&ppp_net_ops);
931 out:
932 return err;
933 }
934
935 /*
936 * Network interface unit routines.
937 */
938 static netdev_tx_t
939 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
940 {
941 struct ppp *ppp = netdev_priv(dev);
942 int npi, proto;
943 unsigned char *pp;
944
945 npi = ethertype_to_npindex(ntohs(skb->protocol));
946 if (npi < 0)
947 goto outf;
948
949 /* Drop, accept or reject the packet */
950 switch (ppp->npmode[npi]) {
951 case NPMODE_PASS:
952 break;
953 case NPMODE_QUEUE:
954 /* it would be nice to have a way to tell the network
955 system to queue this one up for later. */
956 goto outf;
957 case NPMODE_DROP:
958 case NPMODE_ERROR:
959 goto outf;
960 }
961
962 /* Put the 2-byte PPP protocol number on the front,
963 making sure there is room for the address and control fields. */
964 if (skb_cow_head(skb, PPP_HDRLEN))
965 goto outf;
966
967 pp = skb_push(skb, 2);
968 proto = npindex_to_proto[npi];
969 put_unaligned_be16(proto, pp);
970
971 netif_stop_queue(dev);
972 skb_queue_tail(&ppp->file.xq, skb);
973 ppp_xmit_process(ppp);
974 return NETDEV_TX_OK;
975
976 outf:
977 kfree_skb(skb);
978 ++dev->stats.tx_dropped;
979 return NETDEV_TX_OK;
980 }
981
982 static int
983 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
984 {
985 struct ppp *ppp = netdev_priv(dev);
986 int err = -EFAULT;
987 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
988 struct ppp_stats stats;
989 struct ppp_comp_stats cstats;
990 char *vers;
991
992 switch (cmd) {
993 case SIOCGPPPSTATS:
994 ppp_get_stats(ppp, &stats);
995 if (copy_to_user(addr, &stats, sizeof(stats)))
996 break;
997 err = 0;
998 break;
999
1000 case SIOCGPPPCSTATS:
1001 memset(&cstats, 0, sizeof(cstats));
1002 if (ppp->xc_state)
1003 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
1004 if (ppp->rc_state)
1005 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
1006 if (copy_to_user(addr, &cstats, sizeof(cstats)))
1007 break;
1008 err = 0;
1009 break;
1010
1011 case SIOCGPPPVER:
1012 vers = PPP_VERSION;
1013 if (copy_to_user(addr, vers, strlen(vers) + 1))
1014 break;
1015 err = 0;
1016 break;
1017
1018 default:
1019 err = -EINVAL;
1020 }
1021
1022 return err;
1023 }
1024
1025 static const struct net_device_ops ppp_netdev_ops = {
1026 .ndo_start_xmit = ppp_start_xmit,
1027 .ndo_do_ioctl = ppp_net_ioctl,
1028 };
1029
1030 static void ppp_setup(struct net_device *dev)
1031 {
1032 dev->netdev_ops = &ppp_netdev_ops;
1033 dev->hard_header_len = PPP_HDRLEN;
1034 dev->mtu = PPP_MTU;
1035 dev->addr_len = 0;
1036 dev->tx_queue_len = 3;
1037 dev->type = ARPHRD_PPP;
1038 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1039 dev->features |= NETIF_F_NETNS_LOCAL;
1040 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1041 }
1042
1043 /*
1044 * Transmit-side routines.
1045 */
1046
1047 /*
1048 * Called to do any work queued up on the transmit side
1049 * that can now be done.
1050 */
1051 static void
1052 ppp_xmit_process(struct ppp *ppp)
1053 {
1054 struct sk_buff *skb;
1055
1056 ppp_xmit_lock(ppp);
1057 if (!ppp->closing) {
1058 ppp_push(ppp);
1059 while (!ppp->xmit_pending &&
1060 (skb = skb_dequeue(&ppp->file.xq)))
1061 ppp_send_frame(ppp, skb);
1062 /* If there's no work left to do, tell the core net
1063 code that we can accept some more. */
1064 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1065 netif_wake_queue(ppp->dev);
1066 }
1067 ppp_xmit_unlock(ppp);
1068 }
1069
1070 static inline struct sk_buff *
1071 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1072 {
1073 struct sk_buff *new_skb;
1074 int len;
1075 int new_skb_size = ppp->dev->mtu +
1076 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1077 int compressor_skb_size = ppp->dev->mtu +
1078 ppp->xcomp->comp_extra + PPP_HDRLEN;
1079 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1080 if (!new_skb) {
1081 if (net_ratelimit())
1082 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n");
1083 return NULL;
1084 }
1085 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1086 skb_reserve(new_skb,
1087 ppp->dev->hard_header_len - PPP_HDRLEN);
1088
1089 /* compressor still expects A/C bytes in hdr */
1090 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1091 new_skb->data, skb->len + 2,
1092 compressor_skb_size);
1093 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1094 kfree_skb(skb);
1095 skb = new_skb;
1096 skb_put(skb, len);
1097 skb_pull(skb, 2); /* pull off A/C bytes */
1098 } else if (len == 0) {
1099 /* didn't compress, or CCP not up yet */
1100 kfree_skb(new_skb);
1101 new_skb = skb;
1102 } else {
1103 /*
1104 * (len < 0)
1105 * MPPE requires that we do not send unencrypted
1106 * frames. The compressor will return -1 if we
1107 * should drop the frame. We cannot simply test
1108 * the compress_proto because MPPE and MPPC share
1109 * the same number.
1110 */
1111 if (net_ratelimit())
1112 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n");
1113 kfree_skb(skb);
1114 kfree_skb(new_skb);
1115 new_skb = NULL;
1116 }
1117 return new_skb;
1118 }
1119
1120 /*
1121 * Compress and send a frame.
1122 * The caller should have locked the xmit path,
1123 * and xmit_pending should be 0.
1124 */
1125 static void
1126 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1127 {
1128 int proto = PPP_PROTO(skb);
1129 struct sk_buff *new_skb;
1130 int len;
1131 unsigned char *cp;
1132
1133 if (proto < 0x8000) {
1134 #ifdef CONFIG_PPP_FILTER
1135 /* check if we should pass this packet */
1136 /* the filter instructions are constructed assuming
1137 a four-byte PPP header on each packet */
1138 *skb_push(skb, 2) = 1;
1139 if (ppp->pass_filter &&
1140 sk_run_filter(skb, ppp->pass_filter) == 0) {
1141 if (ppp->debug & 1)
1142 netdev_printk(KERN_DEBUG, ppp->dev,
1143 "PPP: outbound frame "
1144 "not passed\n");
1145 kfree_skb(skb);
1146 return;
1147 }
1148 /* if this packet passes the active filter, record the time */
1149 if (!(ppp->active_filter &&
1150 sk_run_filter(skb, ppp->active_filter) == 0))
1151 ppp->last_xmit = jiffies;
1152 skb_pull(skb, 2);
1153 #else
1154 /* for data packets, record the time */
1155 ppp->last_xmit = jiffies;
1156 #endif /* CONFIG_PPP_FILTER */
1157 }
1158
1159 ++ppp->dev->stats.tx_packets;
1160 ppp->dev->stats.tx_bytes += skb->len - 2;
1161
1162 switch (proto) {
1163 case PPP_IP:
1164 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1165 break;
1166 /* try to do VJ TCP header compression */
1167 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1168 GFP_ATOMIC);
1169 if (!new_skb) {
1170 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n");
1171 goto drop;
1172 }
1173 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1174 cp = skb->data + 2;
1175 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1176 new_skb->data + 2, &cp,
1177 !(ppp->flags & SC_NO_TCP_CCID));
1178 if (cp == skb->data + 2) {
1179 /* didn't compress */
1180 kfree_skb(new_skb);
1181 } else {
1182 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1183 proto = PPP_VJC_COMP;
1184 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1185 } else {
1186 proto = PPP_VJC_UNCOMP;
1187 cp[0] = skb->data[2];
1188 }
1189 kfree_skb(skb);
1190 skb = new_skb;
1191 cp = skb_put(skb, len + 2);
1192 cp[0] = 0;
1193 cp[1] = proto;
1194 }
1195 break;
1196
1197 case PPP_CCP:
1198 /* peek at outbound CCP frames */
1199 ppp_ccp_peek(ppp, skb, 0);
1200 break;
1201 }
1202
1203 /* try to do packet compression */
1204 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state &&
1205 proto != PPP_LCP && proto != PPP_CCP) {
1206 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1207 if (net_ratelimit())
1208 netdev_err(ppp->dev,
1209 "ppp: compression required but "
1210 "down - pkt dropped.\n");
1211 goto drop;
1212 }
1213 skb = pad_compress_skb(ppp, skb);
1214 if (!skb)
1215 goto drop;
1216 }
1217
1218 /*
1219 * If we are waiting for traffic (demand dialling),
1220 * queue it up for pppd to receive.
1221 */
1222 if (ppp->flags & SC_LOOP_TRAFFIC) {
1223 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1224 goto drop;
1225 skb_queue_tail(&ppp->file.rq, skb);
1226 wake_up_interruptible(&ppp->file.rwait);
1227 return;
1228 }
1229
1230 ppp->xmit_pending = skb;
1231 ppp_push(ppp);
1232 return;
1233
1234 drop:
1235 kfree_skb(skb);
1236 ++ppp->dev->stats.tx_errors;
1237 }
1238
1239 /*
1240 * Try to send the frame in xmit_pending.
1241 * The caller should have the xmit path locked.
1242 */
1243 static void
1244 ppp_push(struct ppp *ppp)
1245 {
1246 struct list_head *list;
1247 struct channel *pch;
1248 struct sk_buff *skb = ppp->xmit_pending;
1249
1250 if (!skb)
1251 return;
1252
1253 list = &ppp->channels;
1254 if (list_empty(list)) {
1255 /* nowhere to send the packet, just drop it */
1256 ppp->xmit_pending = NULL;
1257 kfree_skb(skb);
1258 return;
1259 }
1260
1261 if ((ppp->flags & SC_MULTILINK) == 0) {
1262 /* not doing multilink: send it down the first channel */
1263 list = list->next;
1264 pch = list_entry(list, struct channel, clist);
1265
1266 spin_lock_bh(&pch->downl);
1267 if (pch->chan) {
1268 if (pch->chan->ops->start_xmit(pch->chan, skb))
1269 ppp->xmit_pending = NULL;
1270 } else {
1271 /* channel got unregistered */
1272 kfree_skb(skb);
1273 ppp->xmit_pending = NULL;
1274 }
1275 spin_unlock_bh(&pch->downl);
1276 return;
1277 }
1278
1279 #ifdef CONFIG_PPP_MULTILINK
1280 /* Multilink: fragment the packet over as many links
1281 as can take the packet at the moment. */
1282 if (!ppp_mp_explode(ppp, skb))
1283 return;
1284 #endif /* CONFIG_PPP_MULTILINK */
1285
1286 ppp->xmit_pending = NULL;
1287 kfree_skb(skb);
1288 }
1289
1290 #ifdef CONFIG_PPP_MULTILINK
1291 static bool mp_protocol_compress __read_mostly = true;
1292 module_param(mp_protocol_compress, bool, S_IRUGO | S_IWUSR);
1293 MODULE_PARM_DESC(mp_protocol_compress,
1294 "compress protocol id in multilink fragments");
1295
1296 /*
1297 * Divide a packet to be transmitted into fragments and
1298 * send them out the individual links.
1299 */
1300 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1301 {
1302 int len, totlen;
1303 int i, bits, hdrlen, mtu;
1304 int flen;
1305 int navail, nfree, nzero;
1306 int nbigger;
1307 int totspeed;
1308 int totfree;
1309 unsigned char *p, *q;
1310 struct list_head *list;
1311 struct channel *pch;
1312 struct sk_buff *frag;
1313 struct ppp_channel *chan;
1314
1315 totspeed = 0; /*total bitrate of the bundle*/
1316 nfree = 0; /* # channels which have no packet already queued */
1317 navail = 0; /* total # of usable channels (not deregistered) */
1318 nzero = 0; /* number of channels with zero speed associated*/
1319 totfree = 0; /*total # of channels available and
1320 *having no queued packets before
1321 *starting the fragmentation*/
1322
1323 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1324 i = 0;
1325 list_for_each_entry(pch, &ppp->channels, clist) {
1326 if (pch->chan) {
1327 pch->avail = 1;
1328 navail++;
1329 pch->speed = pch->chan->speed;
1330 } else {
1331 pch->avail = 0;
1332 }
1333 if (pch->avail) {
1334 if (skb_queue_empty(&pch->file.xq) ||
1335 !pch->had_frag) {
1336 if (pch->speed == 0)
1337 nzero++;
1338 else
1339 totspeed += pch->speed;
1340
1341 pch->avail = 2;
1342 ++nfree;
1343 ++totfree;
1344 }
1345 if (!pch->had_frag && i < ppp->nxchan)
1346 ppp->nxchan = i;
1347 }
1348 ++i;
1349 }
1350 /*
1351 * Don't start sending this packet unless at least half of
1352 * the channels are free. This gives much better TCP
1353 * performance if we have a lot of channels.
1354 */
1355 if (nfree == 0 || nfree < navail / 2)
1356 return 0; /* can't take now, leave it in xmit_pending */
1357
1358 /* Do protocol field compression */
1359 p = skb->data;
1360 len = skb->len;
1361 if (*p == 0 && mp_protocol_compress) {
1362 ++p;
1363 --len;
1364 }
1365
1366 totlen = len;
1367 nbigger = len % nfree;
1368
1369 /* skip to the channel after the one we last used
1370 and start at that one */
1371 list = &ppp->channels;
1372 for (i = 0; i < ppp->nxchan; ++i) {
1373 list = list->next;
1374 if (list == &ppp->channels) {
1375 i = 0;
1376 break;
1377 }
1378 }
1379
1380 /* create a fragment for each channel */
1381 bits = B;
1382 while (len > 0) {
1383 list = list->next;
1384 if (list == &ppp->channels) {
1385 i = 0;
1386 continue;
1387 }
1388 pch = list_entry(list, struct channel, clist);
1389 ++i;
1390 if (!pch->avail)
1391 continue;
1392
1393 /*
1394 * Skip this channel if it has a fragment pending already and
1395 * we haven't given a fragment to all of the free channels.
1396 */
1397 if (pch->avail == 1) {
1398 if (nfree > 0)
1399 continue;
1400 } else {
1401 pch->avail = 1;
1402 }
1403
1404 /* check the channel's mtu and whether it is still attached. */
1405 spin_lock_bh(&pch->downl);
1406 if (pch->chan == NULL) {
1407 /* can't use this channel, it's being deregistered */
1408 if (pch->speed == 0)
1409 nzero--;
1410 else
1411 totspeed -= pch->speed;
1412
1413 spin_unlock_bh(&pch->downl);
1414 pch->avail = 0;
1415 totlen = len;
1416 totfree--;
1417 nfree--;
1418 if (--navail == 0)
1419 break;
1420 continue;
1421 }
1422
1423 /*
1424 *if the channel speed is not set divide
1425 *the packet evenly among the free channels;
1426 *otherwise divide it according to the speed
1427 *of the channel we are going to transmit on
1428 */
1429 flen = len;
1430 if (nfree > 0) {
1431 if (pch->speed == 0) {
1432 flen = len/nfree;
1433 if (nbigger > 0) {
1434 flen++;
1435 nbigger--;
1436 }
1437 } else {
1438 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
1439 ((totspeed*totfree)/pch->speed)) - hdrlen;
1440 if (nbigger > 0) {
1441 flen += ((totfree - nzero)*pch->speed)/totspeed;
1442 nbigger -= ((totfree - nzero)*pch->speed)/
1443 totspeed;
1444 }
1445 }
1446 nfree--;
1447 }
1448
1449 /*
1450 *check if we are on the last channel or
1451 *we exceded the length of the data to
1452 *fragment
1453 */
1454 if ((nfree <= 0) || (flen > len))
1455 flen = len;
1456 /*
1457 *it is not worth to tx on slow channels:
1458 *in that case from the resulting flen according to the
1459 *above formula will be equal or less than zero.
1460 *Skip the channel in this case
1461 */
1462 if (flen <= 0) {
1463 pch->avail = 2;
1464 spin_unlock_bh(&pch->downl);
1465 continue;
1466 }
1467
1468 /*
1469 * hdrlen includes the 2-byte PPP protocol field, but the
1470 * MTU counts only the payload excluding the protocol field.
1471 * (RFC1661 Section 2)
1472 */
1473 mtu = pch->chan->mtu - (hdrlen - 2);
1474 if (mtu < 4)
1475 mtu = 4;
1476 if (flen > mtu)
1477 flen = mtu;
1478 if (flen == len)
1479 bits |= E;
1480 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1481 if (!frag)
1482 goto noskb;
1483 q = skb_put(frag, flen + hdrlen);
1484
1485 /* make the MP header */
1486 put_unaligned_be16(PPP_MP, q);
1487 if (ppp->flags & SC_MP_XSHORTSEQ) {
1488 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1489 q[3] = ppp->nxseq;
1490 } else {
1491 q[2] = bits;
1492 q[3] = ppp->nxseq >> 16;
1493 q[4] = ppp->nxseq >> 8;
1494 q[5] = ppp->nxseq;
1495 }
1496
1497 memcpy(q + hdrlen, p, flen);
1498
1499 /* try to send it down the channel */
1500 chan = pch->chan;
1501 if (!skb_queue_empty(&pch->file.xq) ||
1502 !chan->ops->start_xmit(chan, frag))
1503 skb_queue_tail(&pch->file.xq, frag);
1504 pch->had_frag = 1;
1505 p += flen;
1506 len -= flen;
1507 ++ppp->nxseq;
1508 bits = 0;
1509 spin_unlock_bh(&pch->downl);
1510 }
1511 ppp->nxchan = i;
1512
1513 return 1;
1514
1515 noskb:
1516 spin_unlock_bh(&pch->downl);
1517 if (ppp->debug & 1)
1518 netdev_err(ppp->dev, "PPP: no memory (fragment)\n");
1519 ++ppp->dev->stats.tx_errors;
1520 ++ppp->nxseq;
1521 return 1; /* abandon the frame */
1522 }
1523 #endif /* CONFIG_PPP_MULTILINK */
1524
1525 /*
1526 * Try to send data out on a channel.
1527 */
1528 static void
1529 ppp_channel_push(struct channel *pch)
1530 {
1531 struct sk_buff *skb;
1532 struct ppp *ppp;
1533
1534 spin_lock_bh(&pch->downl);
1535 if (pch->chan) {
1536 while (!skb_queue_empty(&pch->file.xq)) {
1537 skb = skb_dequeue(&pch->file.xq);
1538 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1539 /* put the packet back and try again later */
1540 skb_queue_head(&pch->file.xq, skb);
1541 break;
1542 }
1543 }
1544 } else {
1545 /* channel got deregistered */
1546 skb_queue_purge(&pch->file.xq);
1547 }
1548 spin_unlock_bh(&pch->downl);
1549 /* see if there is anything from the attached unit to be sent */
1550 if (skb_queue_empty(&pch->file.xq)) {
1551 read_lock_bh(&pch->upl);
1552 ppp = pch->ppp;
1553 if (ppp)
1554 ppp_xmit_process(ppp);
1555 read_unlock_bh(&pch->upl);
1556 }
1557 }
1558
1559 /*
1560 * Receive-side routines.
1561 */
1562
1563 struct ppp_mp_skb_parm {
1564 u32 sequence;
1565 u8 BEbits;
1566 };
1567 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb))
1568
1569 static inline void
1570 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1571 {
1572 ppp_recv_lock(ppp);
1573 if (!ppp->closing)
1574 ppp_receive_frame(ppp, skb, pch);
1575 else
1576 kfree_skb(skb);
1577 ppp_recv_unlock(ppp);
1578 }
1579
1580 void
1581 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1582 {
1583 struct channel *pch = chan->ppp;
1584 int proto;
1585
1586 if (!pch) {
1587 kfree_skb(skb);
1588 return;
1589 }
1590
1591 read_lock_bh(&pch->upl);
1592 if (!pskb_may_pull(skb, 2)) {
1593 kfree_skb(skb);
1594 if (pch->ppp) {
1595 ++pch->ppp->dev->stats.rx_length_errors;
1596 ppp_receive_error(pch->ppp);
1597 }
1598 goto done;
1599 }
1600
1601 proto = PPP_PROTO(skb);
1602 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1603 /* put it on the channel queue */
1604 skb_queue_tail(&pch->file.rq, skb);
1605 /* drop old frames if queue too long */
1606 while (pch->file.rq.qlen > PPP_MAX_RQLEN &&
1607 (skb = skb_dequeue(&pch->file.rq)))
1608 kfree_skb(skb);
1609 wake_up_interruptible(&pch->file.rwait);
1610 } else {
1611 ppp_do_recv(pch->ppp, skb, pch);
1612 }
1613
1614 done:
1615 read_unlock_bh(&pch->upl);
1616 }
1617
1618 /* Put a 0-length skb in the receive queue as an error indication */
1619 void
1620 ppp_input_error(struct ppp_channel *chan, int code)
1621 {
1622 struct channel *pch = chan->ppp;
1623 struct sk_buff *skb;
1624
1625 if (!pch)
1626 return;
1627
1628 read_lock_bh(&pch->upl);
1629 if (pch->ppp) {
1630 skb = alloc_skb(0, GFP_ATOMIC);
1631 if (skb) {
1632 skb->len = 0; /* probably unnecessary */
1633 skb->cb[0] = code;
1634 ppp_do_recv(pch->ppp, skb, pch);
1635 }
1636 }
1637 read_unlock_bh(&pch->upl);
1638 }
1639
1640 /*
1641 * We come in here to process a received frame.
1642 * The receive side of the ppp unit is locked.
1643 */
1644 static void
1645 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1646 {
1647 /* note: a 0-length skb is used as an error indication */
1648 if (skb->len > 0) {
1649 #ifdef CONFIG_PPP_MULTILINK
1650 /* XXX do channel-level decompression here */
1651 if (PPP_PROTO(skb) == PPP_MP)
1652 ppp_receive_mp_frame(ppp, skb, pch);
1653 else
1654 #endif /* CONFIG_PPP_MULTILINK */
1655 ppp_receive_nonmp_frame(ppp, skb);
1656 } else {
1657 kfree_skb(skb);
1658 ppp_receive_error(ppp);
1659 }
1660 }
1661
1662 static void
1663 ppp_receive_error(struct ppp *ppp)
1664 {
1665 ++ppp->dev->stats.rx_errors;
1666 if (ppp->vj)
1667 slhc_toss(ppp->vj);
1668 }
1669
1670 static void
1671 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1672 {
1673 struct sk_buff *ns;
1674 int proto, len, npi;
1675
1676 /*
1677 * Decompress the frame, if compressed.
1678 * Note that some decompressors need to see uncompressed frames
1679 * that come in as well as compressed frames.
1680 */
1681 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) &&
1682 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1683 skb = ppp_decompress_frame(ppp, skb);
1684
1685 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1686 goto err;
1687
1688 proto = PPP_PROTO(skb);
1689 switch (proto) {
1690 case PPP_VJC_COMP:
1691 /* decompress VJ compressed packets */
1692 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1693 goto err;
1694
1695 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1696 /* copy to a new sk_buff with more tailroom */
1697 ns = dev_alloc_skb(skb->len + 128);
1698 if (!ns) {
1699 netdev_err(ppp->dev, "PPP: no memory "
1700 "(VJ decomp)\n");
1701 goto err;
1702 }
1703 skb_reserve(ns, 2);
1704 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1705 kfree_skb(skb);
1706 skb = ns;
1707 }
1708 else
1709 skb->ip_summed = CHECKSUM_NONE;
1710
1711 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1712 if (len <= 0) {
1713 netdev_printk(KERN_DEBUG, ppp->dev,
1714 "PPP: VJ decompression error\n");
1715 goto err;
1716 }
1717 len += 2;
1718 if (len > skb->len)
1719 skb_put(skb, len - skb->len);
1720 else if (len < skb->len)
1721 skb_trim(skb, len);
1722 proto = PPP_IP;
1723 break;
1724
1725 case PPP_VJC_UNCOMP:
1726 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1727 goto err;
1728
1729 /* Until we fix the decompressor need to make sure
1730 * data portion is linear.
1731 */
1732 if (!pskb_may_pull(skb, skb->len))
1733 goto err;
1734
1735 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1736 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n");
1737 goto err;
1738 }
1739 proto = PPP_IP;
1740 break;
1741
1742 case PPP_CCP:
1743 ppp_ccp_peek(ppp, skb, 1);
1744 break;
1745 }
1746
1747 ++ppp->dev->stats.rx_packets;
1748 ppp->dev->stats.rx_bytes += skb->len - 2;
1749
1750 npi = proto_to_npindex(proto);
1751 if (npi < 0) {
1752 /* control or unknown frame - pass it to pppd */
1753 skb_queue_tail(&ppp->file.rq, skb);
1754 /* limit queue length by dropping old frames */
1755 while (ppp->file.rq.qlen > PPP_MAX_RQLEN &&
1756 (skb = skb_dequeue(&ppp->file.rq)))
1757 kfree_skb(skb);
1758 /* wake up any process polling or blocking on read */
1759 wake_up_interruptible(&ppp->file.rwait);
1760
1761 } else {
1762 /* network protocol frame - give it to the kernel */
1763
1764 #ifdef CONFIG_PPP_FILTER
1765 /* check if the packet passes the pass and active filters */
1766 /* the filter instructions are constructed assuming
1767 a four-byte PPP header on each packet */
1768 if (ppp->pass_filter || ppp->active_filter) {
1769 if (skb_cloned(skb) &&
1770 pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
1771 goto err;
1772
1773 *skb_push(skb, 2) = 0;
1774 if (ppp->pass_filter &&
1775 sk_run_filter(skb, ppp->pass_filter) == 0) {
1776 if (ppp->debug & 1)
1777 netdev_printk(KERN_DEBUG, ppp->dev,
1778 "PPP: inbound frame "
1779 "not passed\n");
1780 kfree_skb(skb);
1781 return;
1782 }
1783 if (!(ppp->active_filter &&
1784 sk_run_filter(skb, ppp->active_filter) == 0))
1785 ppp->last_recv = jiffies;
1786 __skb_pull(skb, 2);
1787 } else
1788 #endif /* CONFIG_PPP_FILTER */
1789 ppp->last_recv = jiffies;
1790
1791 if ((ppp->dev->flags & IFF_UP) == 0 ||
1792 ppp->npmode[npi] != NPMODE_PASS) {
1793 kfree_skb(skb);
1794 } else {
1795 /* chop off protocol */
1796 skb_pull_rcsum(skb, 2);
1797 skb->dev = ppp->dev;
1798 skb->protocol = htons(npindex_to_ethertype[npi]);
1799 skb_reset_mac_header(skb);
1800 netif_rx(skb);
1801 }
1802 }
1803 return;
1804
1805 err:
1806 kfree_skb(skb);
1807 ppp_receive_error(ppp);
1808 }
1809
1810 static struct sk_buff *
1811 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1812 {
1813 int proto = PPP_PROTO(skb);
1814 struct sk_buff *ns;
1815 int len;
1816
1817 /* Until we fix all the decompressor's need to make sure
1818 * data portion is linear.
1819 */
1820 if (!pskb_may_pull(skb, skb->len))
1821 goto err;
1822
1823 if (proto == PPP_COMP) {
1824 int obuff_size;
1825
1826 switch(ppp->rcomp->compress_proto) {
1827 case CI_MPPE:
1828 obuff_size = ppp->mru + PPP_HDRLEN + 1;
1829 break;
1830 default:
1831 obuff_size = ppp->mru + PPP_HDRLEN;
1832 break;
1833 }
1834
1835 ns = dev_alloc_skb(obuff_size);
1836 if (!ns) {
1837 netdev_err(ppp->dev, "ppp_decompress_frame: "
1838 "no memory\n");
1839 goto err;
1840 }
1841 /* the decompressor still expects the A/C bytes in the hdr */
1842 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1843 skb->len + 2, ns->data, obuff_size);
1844 if (len < 0) {
1845 /* Pass the compressed frame to pppd as an
1846 error indication. */
1847 if (len == DECOMP_FATALERROR)
1848 ppp->rstate |= SC_DC_FERROR;
1849 kfree_skb(ns);
1850 goto err;
1851 }
1852
1853 kfree_skb(skb);
1854 skb = ns;
1855 skb_put(skb, len);
1856 skb_pull(skb, 2); /* pull off the A/C bytes */
1857
1858 } else {
1859 /* Uncompressed frame - pass to decompressor so it
1860 can update its dictionary if necessary. */
1861 if (ppp->rcomp->incomp)
1862 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1863 skb->len + 2);
1864 }
1865
1866 return skb;
1867
1868 err:
1869 ppp->rstate |= SC_DC_ERROR;
1870 ppp_receive_error(ppp);
1871 return skb;
1872 }
1873
1874 #ifdef CONFIG_PPP_MULTILINK
1875 /*
1876 * Receive a multilink frame.
1877 * We put it on the reconstruction queue and then pull off
1878 * as many completed frames as we can.
1879 */
1880 static void
1881 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1882 {
1883 u32 mask, seq;
1884 struct channel *ch;
1885 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1886
1887 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
1888 goto err; /* no good, throw it away */
1889
1890 /* Decode sequence number and begin/end bits */
1891 if (ppp->flags & SC_MP_SHORTSEQ) {
1892 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1893 mask = 0xfff;
1894 } else {
1895 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1896 mask = 0xffffff;
1897 }
1898 PPP_MP_CB(skb)->BEbits = skb->data[2];
1899 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
1900
1901 /*
1902 * Do protocol ID decompression on the first fragment of each packet.
1903 */
1904 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1))
1905 *skb_push(skb, 1) = 0;
1906
1907 /*
1908 * Expand sequence number to 32 bits, making it as close
1909 * as possible to ppp->minseq.
1910 */
1911 seq |= ppp->minseq & ~mask;
1912 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
1913 seq += mask + 1;
1914 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
1915 seq -= mask + 1; /* should never happen */
1916 PPP_MP_CB(skb)->sequence = seq;
1917 pch->lastseq = seq;
1918
1919 /*
1920 * If this packet comes before the next one we were expecting,
1921 * drop it.
1922 */
1923 if (seq_before(seq, ppp->nextseq)) {
1924 kfree_skb(skb);
1925 ++ppp->dev->stats.rx_dropped;
1926 ppp_receive_error(ppp);
1927 return;
1928 }
1929
1930 /*
1931 * Reevaluate minseq, the minimum over all channels of the
1932 * last sequence number received on each channel. Because of
1933 * the increasing sequence number rule, we know that any fragment
1934 * before `minseq' which hasn't arrived is never going to arrive.
1935 * The list of channels can't change because we have the receive
1936 * side of the ppp unit locked.
1937 */
1938 list_for_each_entry(ch, &ppp->channels, clist) {
1939 if (seq_before(ch->lastseq, seq))
1940 seq = ch->lastseq;
1941 }
1942 if (seq_before(ppp->minseq, seq))
1943 ppp->minseq = seq;
1944
1945 /* Put the fragment on the reconstruction queue */
1946 ppp_mp_insert(ppp, skb);
1947
1948 /* If the queue is getting long, don't wait any longer for packets
1949 before the start of the queue. */
1950 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
1951 struct sk_buff *mskb = skb_peek(&ppp->mrq);
1952 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence))
1953 ppp->minseq = PPP_MP_CB(mskb)->sequence;
1954 }
1955
1956 /* Pull completed packets off the queue and receive them. */
1957 while ((skb = ppp_mp_reconstruct(ppp))) {
1958 if (pskb_may_pull(skb, 2))
1959 ppp_receive_nonmp_frame(ppp, skb);
1960 else {
1961 ++ppp->dev->stats.rx_length_errors;
1962 kfree_skb(skb);
1963 ppp_receive_error(ppp);
1964 }
1965 }
1966
1967 return;
1968
1969 err:
1970 kfree_skb(skb);
1971 ppp_receive_error(ppp);
1972 }
1973
1974 /*
1975 * Insert a fragment on the MP reconstruction queue.
1976 * The queue is ordered by increasing sequence number.
1977 */
1978 static void
1979 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
1980 {
1981 struct sk_buff *p;
1982 struct sk_buff_head *list = &ppp->mrq;
1983 u32 seq = PPP_MP_CB(skb)->sequence;
1984
1985 /* N.B. we don't need to lock the list lock because we have the
1986 ppp unit receive-side lock. */
1987 skb_queue_walk(list, p) {
1988 if (seq_before(seq, PPP_MP_CB(p)->sequence))
1989 break;
1990 }
1991 __skb_queue_before(list, p, skb);
1992 }
1993
1994 /*
1995 * Reconstruct a packet from the MP fragment queue.
1996 * We go through increasing sequence numbers until we find a
1997 * complete packet, or we get to the sequence number for a fragment
1998 * which hasn't arrived but might still do so.
1999 */
2000 static struct sk_buff *
2001 ppp_mp_reconstruct(struct ppp *ppp)
2002 {
2003 u32 seq = ppp->nextseq;
2004 u32 minseq = ppp->minseq;
2005 struct sk_buff_head *list = &ppp->mrq;
2006 struct sk_buff *p, *tmp;
2007 struct sk_buff *head, *tail;
2008 struct sk_buff *skb = NULL;
2009 int lost = 0, len = 0;
2010
2011 if (ppp->mrru == 0) /* do nothing until mrru is set */
2012 return NULL;
2013 head = list->next;
2014 tail = NULL;
2015 skb_queue_walk_safe(list, p, tmp) {
2016 again:
2017 if (seq_before(PPP_MP_CB(p)->sequence, seq)) {
2018 /* this can't happen, anyway ignore the skb */
2019 netdev_err(ppp->dev, "ppp_mp_reconstruct bad "
2020 "seq %u < %u\n",
2021 PPP_MP_CB(p)->sequence, seq);
2022 __skb_unlink(p, list);
2023 kfree_skb(p);
2024 continue;
2025 }
2026 if (PPP_MP_CB(p)->sequence != seq) {
2027 /* Fragment `seq' is missing. If it is after
2028 minseq, it might arrive later, so stop here. */
2029 if (seq_after(seq, minseq))
2030 break;
2031 /* Fragment `seq' is lost, keep going. */
2032 lost = 1;
2033 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)?
2034 minseq + 1: PPP_MP_CB(p)->sequence;
2035 goto again;
2036 }
2037
2038 /*
2039 * At this point we know that all the fragments from
2040 * ppp->nextseq to seq are either present or lost.
2041 * Also, there are no complete packets in the queue
2042 * that have no missing fragments and end before this
2043 * fragment.
2044 */
2045
2046 /* B bit set indicates this fragment starts a packet */
2047 if (PPP_MP_CB(p)->BEbits & B) {
2048 head = p;
2049 lost = 0;
2050 len = 0;
2051 }
2052
2053 len += p->len;
2054
2055 /* Got a complete packet yet? */
2056 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) &&
2057 (PPP_MP_CB(head)->BEbits & B)) {
2058 if (len > ppp->mrru + 2) {
2059 ++ppp->dev->stats.rx_length_errors;
2060 netdev_printk(KERN_DEBUG, ppp->dev,
2061 "PPP: reconstructed packet"
2062 " is too long (%d)\n", len);
2063 } else {
2064 tail = p;
2065 break;
2066 }
2067 ppp->nextseq = seq + 1;
2068 }
2069
2070 /*
2071 * If this is the ending fragment of a packet,
2072 * and we haven't found a complete valid packet yet,
2073 * we can discard up to and including this fragment.
2074 */
2075 if (PPP_MP_CB(p)->BEbits & E) {
2076 struct sk_buff *tmp2;
2077
2078 skb_queue_reverse_walk_from_safe(list, p, tmp2) {
2079 __skb_unlink(p, list);
2080 kfree_skb(p);
2081 }
2082 head = skb_peek(list);
2083 if (!head)
2084 break;
2085 }
2086 ++seq;
2087 }
2088
2089 /* If we have a complete packet, copy it all into one skb. */
2090 if (tail != NULL) {
2091 /* If we have discarded any fragments,
2092 signal a receive error. */
2093 if (PPP_MP_CB(head)->sequence != ppp->nextseq) {
2094 if (ppp->debug & 1)
2095 netdev_printk(KERN_DEBUG, ppp->dev,
2096 " missed pkts %u..%u\n",
2097 ppp->nextseq,
2098 PPP_MP_CB(head)->sequence-1);
2099 ++ppp->dev->stats.rx_dropped;
2100 ppp_receive_error(ppp);
2101 }
2102
2103 skb = head;
2104 if (head != tail) {
2105 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list;
2106 p = skb_queue_next(list, head);
2107 __skb_unlink(skb, list);
2108 skb_queue_walk_from_safe(list, p, tmp) {
2109 __skb_unlink(p, list);
2110 *fragpp = p;
2111 p->next = NULL;
2112 fragpp = &p->next;
2113
2114 skb->len += p->len;
2115 skb->data_len += p->len;
2116 skb->truesize += p->len;
2117
2118 if (p == tail)
2119 break;
2120 }
2121 } else {
2122 __skb_unlink(skb, list);
2123 }
2124
2125 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1;
2126 }
2127
2128 return skb;
2129 }
2130 #endif /* CONFIG_PPP_MULTILINK */
2131
2132 /*
2133 * Channel interface.
2134 */
2135
2136 /* Create a new, unattached ppp channel. */
2137 int ppp_register_channel(struct ppp_channel *chan)
2138 {
2139 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2140 }
2141
2142 /* Create a new, unattached ppp channel for specified net. */
2143 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
2144 {
2145 struct channel *pch;
2146 struct ppp_net *pn;
2147
2148 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2149 if (!pch)
2150 return -ENOMEM;
2151
2152 pn = ppp_pernet(net);
2153
2154 pch->ppp = NULL;
2155 pch->chan = chan;
2156 pch->chan_net = net;
2157 chan->ppp = pch;
2158 init_ppp_file(&pch->file, CHANNEL);
2159 pch->file.hdrlen = chan->hdrlen;
2160 #ifdef CONFIG_PPP_MULTILINK
2161 pch->lastseq = -1;
2162 #endif /* CONFIG_PPP_MULTILINK */
2163 init_rwsem(&pch->chan_sem);
2164 spin_lock_init(&pch->downl);
2165 rwlock_init(&pch->upl);
2166
2167 spin_lock_bh(&pn->all_channels_lock);
2168 pch->file.index = ++pn->last_channel_index;
2169 list_add(&pch->list, &pn->new_channels);
2170 atomic_inc(&channel_count);
2171 spin_unlock_bh(&pn->all_channels_lock);
2172
2173 return 0;
2174 }
2175
2176 /*
2177 * Return the index of a channel.
2178 */
2179 int ppp_channel_index(struct ppp_channel *chan)
2180 {
2181 struct channel *pch = chan->ppp;
2182
2183 if (pch)
2184 return pch->file.index;
2185 return -1;
2186 }
2187
2188 /*
2189 * Return the PPP unit number to which a channel is connected.
2190 */
2191 int ppp_unit_number(struct ppp_channel *chan)
2192 {
2193 struct channel *pch = chan->ppp;
2194 int unit = -1;
2195
2196 if (pch) {
2197 read_lock_bh(&pch->upl);
2198 if (pch->ppp)
2199 unit = pch->ppp->file.index;
2200 read_unlock_bh(&pch->upl);
2201 }
2202 return unit;
2203 }
2204
2205 /*
2206 * Return the PPP device interface name of a channel.
2207 */
2208 char *ppp_dev_name(struct ppp_channel *chan)
2209 {
2210 struct channel *pch = chan->ppp;
2211 char *name = NULL;
2212
2213 if (pch) {
2214 read_lock_bh(&pch->upl);
2215 if (pch->ppp && pch->ppp->dev)
2216 name = pch->ppp->dev->name;
2217 read_unlock_bh(&pch->upl);
2218 }
2219 return name;
2220 }
2221
2222
2223 /*
2224 * Disconnect a channel from the generic layer.
2225 * This must be called in process context.
2226 */
2227 void
2228 ppp_unregister_channel(struct ppp_channel *chan)
2229 {
2230 struct channel *pch = chan->ppp;
2231 struct ppp_net *pn;
2232
2233 if (!pch)
2234 return; /* should never happen */
2235
2236 chan->ppp = NULL;
2237
2238 /*
2239 * This ensures that we have returned from any calls into the
2240 * the channel's start_xmit or ioctl routine before we proceed.
2241 */
2242 down_write(&pch->chan_sem);
2243 spin_lock_bh(&pch->downl);
2244 pch->chan = NULL;
2245 spin_unlock_bh(&pch->downl);
2246 up_write(&pch->chan_sem);
2247 ppp_disconnect_channel(pch);
2248
2249 pn = ppp_pernet(pch->chan_net);
2250 spin_lock_bh(&pn->all_channels_lock);
2251 list_del(&pch->list);
2252 spin_unlock_bh(&pn->all_channels_lock);
2253
2254 pch->file.dead = 1;
2255 wake_up_interruptible(&pch->file.rwait);
2256 if (atomic_dec_and_test(&pch->file.refcnt))
2257 ppp_destroy_channel(pch);
2258 }
2259
2260 /*
2261 * Callback from a channel when it can accept more to transmit.
2262 * This should be called at BH/softirq level, not interrupt level.
2263 */
2264 void
2265 ppp_output_wakeup(struct ppp_channel *chan)
2266 {
2267 struct channel *pch = chan->ppp;
2268
2269 if (!pch)
2270 return;
2271 ppp_channel_push(pch);
2272 }
2273
2274 /*
2275 * Compression control.
2276 */
2277
2278 /* Process the PPPIOCSCOMPRESS ioctl. */
2279 static int
2280 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2281 {
2282 int err;
2283 struct compressor *cp, *ocomp;
2284 struct ppp_option_data data;
2285 void *state, *ostate;
2286 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2287
2288 err = -EFAULT;
2289 if (copy_from_user(&data, (void __user *) arg, sizeof(data)) ||
2290 (data.length <= CCP_MAX_OPTION_LENGTH &&
2291 copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2292 goto out;
2293 err = -EINVAL;
2294 if (data.length > CCP_MAX_OPTION_LENGTH ||
2295 ccp_option[1] < 2 || ccp_option[1] > data.length)
2296 goto out;
2297
2298 cp = try_then_request_module(
2299 find_compressor(ccp_option[0]),
2300 "ppp-compress-%d", ccp_option[0]);
2301 if (!cp)
2302 goto out;
2303
2304 err = -ENOBUFS;
2305 if (data.transmit) {
2306 state = cp->comp_alloc(ccp_option, data.length);
2307 if (state) {
2308 ppp_xmit_lock(ppp);
2309 ppp->xstate &= ~SC_COMP_RUN;
2310 ocomp = ppp->xcomp;
2311 ostate = ppp->xc_state;
2312 ppp->xcomp = cp;
2313 ppp->xc_state = state;
2314 ppp_xmit_unlock(ppp);
2315 if (ostate) {
2316 ocomp->comp_free(ostate);
2317 module_put(ocomp->owner);
2318 }
2319 err = 0;
2320 } else
2321 module_put(cp->owner);
2322
2323 } else {
2324 state = cp->decomp_alloc(ccp_option, data.length);
2325 if (state) {
2326 ppp_recv_lock(ppp);
2327 ppp->rstate &= ~SC_DECOMP_RUN;
2328 ocomp = ppp->rcomp;
2329 ostate = ppp->rc_state;
2330 ppp->rcomp = cp;
2331 ppp->rc_state = state;
2332 ppp_recv_unlock(ppp);
2333 if (ostate) {
2334 ocomp->decomp_free(ostate);
2335 module_put(ocomp->owner);
2336 }
2337 err = 0;
2338 } else
2339 module_put(cp->owner);
2340 }
2341
2342 out:
2343 return err;
2344 }
2345
2346 /*
2347 * Look at a CCP packet and update our state accordingly.
2348 * We assume the caller has the xmit or recv path locked.
2349 */
2350 static void
2351 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2352 {
2353 unsigned char *dp;
2354 int len;
2355
2356 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2357 return; /* no header */
2358 dp = skb->data + 2;
2359
2360 switch (CCP_CODE(dp)) {
2361 case CCP_CONFREQ:
2362
2363 /* A ConfReq starts negotiation of compression
2364 * in one direction of transmission,
2365 * and hence brings it down...but which way?
2366 *
2367 * Remember:
2368 * A ConfReq indicates what the sender would like to receive
2369 */
2370 if(inbound)
2371 /* He is proposing what I should send */
2372 ppp->xstate &= ~SC_COMP_RUN;
2373 else
2374 /* I am proposing to what he should send */
2375 ppp->rstate &= ~SC_DECOMP_RUN;
2376
2377 break;
2378
2379 case CCP_TERMREQ:
2380 case CCP_TERMACK:
2381 /*
2382 * CCP is going down, both directions of transmission
2383 */
2384 ppp->rstate &= ~SC_DECOMP_RUN;
2385 ppp->xstate &= ~SC_COMP_RUN;
2386 break;
2387
2388 case CCP_CONFACK:
2389 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2390 break;
2391 len = CCP_LENGTH(dp);
2392 if (!pskb_may_pull(skb, len + 2))
2393 return; /* too short */
2394 dp += CCP_HDRLEN;
2395 len -= CCP_HDRLEN;
2396 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2397 break;
2398 if (inbound) {
2399 /* we will start receiving compressed packets */
2400 if (!ppp->rc_state)
2401 break;
2402 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2403 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2404 ppp->rstate |= SC_DECOMP_RUN;
2405 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2406 }
2407 } else {
2408 /* we will soon start sending compressed packets */
2409 if (!ppp->xc_state)
2410 break;
2411 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2412 ppp->file.index, 0, ppp->debug))
2413 ppp->xstate |= SC_COMP_RUN;
2414 }
2415 break;
2416
2417 case CCP_RESETACK:
2418 /* reset the [de]compressor */
2419 if ((ppp->flags & SC_CCP_UP) == 0)
2420 break;
2421 if (inbound) {
2422 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2423 ppp->rcomp->decomp_reset(ppp->rc_state);
2424 ppp->rstate &= ~SC_DC_ERROR;
2425 }
2426 } else {
2427 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2428 ppp->xcomp->comp_reset(ppp->xc_state);
2429 }
2430 break;
2431 }
2432 }
2433
2434 /* Free up compression resources. */
2435 static void
2436 ppp_ccp_closed(struct ppp *ppp)
2437 {
2438 void *xstate, *rstate;
2439 struct compressor *xcomp, *rcomp;
2440
2441 ppp_lock(ppp);
2442 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2443 ppp->xstate = 0;
2444 xcomp = ppp->xcomp;
2445 xstate = ppp->xc_state;
2446 ppp->xc_state = NULL;
2447 ppp->rstate = 0;
2448 rcomp = ppp->rcomp;
2449 rstate = ppp->rc_state;
2450 ppp->rc_state = NULL;
2451 ppp_unlock(ppp);
2452
2453 if (xstate) {
2454 xcomp->comp_free(xstate);
2455 module_put(xcomp->owner);
2456 }
2457 if (rstate) {
2458 rcomp->decomp_free(rstate);
2459 module_put(rcomp->owner);
2460 }
2461 }
2462
2463 /* List of compressors. */
2464 static LIST_HEAD(compressor_list);
2465 static DEFINE_SPINLOCK(compressor_list_lock);
2466
2467 struct compressor_entry {
2468 struct list_head list;
2469 struct compressor *comp;
2470 };
2471
2472 static struct compressor_entry *
2473 find_comp_entry(int proto)
2474 {
2475 struct compressor_entry *ce;
2476
2477 list_for_each_entry(ce, &compressor_list, list) {
2478 if (ce->comp->compress_proto == proto)
2479 return ce;
2480 }
2481 return NULL;
2482 }
2483
2484 /* Register a compressor */
2485 int
2486 ppp_register_compressor(struct compressor *cp)
2487 {
2488 struct compressor_entry *ce;
2489 int ret;
2490 spin_lock(&compressor_list_lock);
2491 ret = -EEXIST;
2492 if (find_comp_entry(cp->compress_proto))
2493 goto out;
2494 ret = -ENOMEM;
2495 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2496 if (!ce)
2497 goto out;
2498 ret = 0;
2499 ce->comp = cp;
2500 list_add(&ce->list, &compressor_list);
2501 out:
2502 spin_unlock(&compressor_list_lock);
2503 return ret;
2504 }
2505
2506 /* Unregister a compressor */
2507 void
2508 ppp_unregister_compressor(struct compressor *cp)
2509 {
2510 struct compressor_entry *ce;
2511
2512 spin_lock(&compressor_list_lock);
2513 ce = find_comp_entry(cp->compress_proto);
2514 if (ce && ce->comp == cp) {
2515 list_del(&ce->list);
2516 kfree(ce);
2517 }
2518 spin_unlock(&compressor_list_lock);
2519 }
2520
2521 /* Find a compressor. */
2522 static struct compressor *
2523 find_compressor(int type)
2524 {
2525 struct compressor_entry *ce;
2526 struct compressor *cp = NULL;
2527
2528 spin_lock(&compressor_list_lock);
2529 ce = find_comp_entry(type);
2530 if (ce) {
2531 cp = ce->comp;
2532 if (!try_module_get(cp->owner))
2533 cp = NULL;
2534 }
2535 spin_unlock(&compressor_list_lock);
2536 return cp;
2537 }
2538
2539 /*
2540 * Miscelleneous stuff.
2541 */
2542
2543 static void
2544 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2545 {
2546 struct slcompress *vj = ppp->vj;
2547
2548 memset(st, 0, sizeof(*st));
2549 st->p.ppp_ipackets = ppp->dev->stats.rx_packets;
2550 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2551 st->p.ppp_ibytes = ppp->dev->stats.rx_bytes;
2552 st->p.ppp_opackets = ppp->dev->stats.tx_packets;
2553 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2554 st->p.ppp_obytes = ppp->dev->stats.tx_bytes;
2555 if (!vj)
2556 return;
2557 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2558 st->vj.vjs_compressed = vj->sls_o_compressed;
2559 st->vj.vjs_searches = vj->sls_o_searches;
2560 st->vj.vjs_misses = vj->sls_o_misses;
2561 st->vj.vjs_errorin = vj->sls_i_error;
2562 st->vj.vjs_tossed = vj->sls_i_tossed;
2563 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2564 st->vj.vjs_compressedin = vj->sls_i_compressed;
2565 }
2566
2567 /*
2568 * Stuff for handling the lists of ppp units and channels
2569 * and for initialization.
2570 */
2571
2572 /*
2573 * Create a new ppp interface unit. Fails if it can't allocate memory
2574 * or if there is already a unit with the requested number.
2575 * unit == -1 means allocate a new number.
2576 */
2577 static struct ppp *
2578 ppp_create_interface(struct net *net, int unit, int *retp)
2579 {
2580 struct ppp *ppp;
2581 struct ppp_net *pn;
2582 struct net_device *dev = NULL;
2583 int ret = -ENOMEM;
2584 int i;
2585
2586 dev = alloc_netdev(sizeof(struct ppp), "", ppp_setup);
2587 if (!dev)
2588 goto out1;
2589
2590 pn = ppp_pernet(net);
2591
2592 ppp = netdev_priv(dev);
2593 ppp->dev = dev;
2594 ppp->mru = PPP_MRU;
2595 init_ppp_file(&ppp->file, INTERFACE);
2596 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2597 for (i = 0; i < NUM_NP; ++i)
2598 ppp->npmode[i] = NPMODE_PASS;
2599 INIT_LIST_HEAD(&ppp->channels);
2600 spin_lock_init(&ppp->rlock);
2601 spin_lock_init(&ppp->wlock);
2602 #ifdef CONFIG_PPP_MULTILINK
2603 ppp->minseq = -1;
2604 skb_queue_head_init(&ppp->mrq);
2605 #endif /* CONFIG_PPP_MULTILINK */
2606
2607 /*
2608 * drum roll: don't forget to set
2609 * the net device is belong to
2610 */
2611 dev_net_set(dev, net);
2612
2613 mutex_lock(&pn->all_ppp_mutex);
2614
2615 if (unit < 0) {
2616 unit = unit_get(&pn->units_idr, ppp);
2617 if (unit < 0) {
2618 ret = unit;
2619 goto out2;
2620 }
2621 } else {
2622 ret = -EEXIST;
2623 if (unit_find(&pn->units_idr, unit))
2624 goto out2; /* unit already exists */
2625 /*
2626 * if caller need a specified unit number
2627 * lets try to satisfy him, otherwise --
2628 * he should better ask us for new unit number
2629 *
2630 * NOTE: yes I know that returning EEXIST it's not
2631 * fair but at least pppd will ask us to allocate
2632 * new unit in this case so user is happy :)
2633 */
2634 unit = unit_set(&pn->units_idr, ppp, unit);
2635 if (unit < 0)
2636 goto out2;
2637 }
2638
2639 /* Initialize the new ppp unit */
2640 ppp->file.index = unit;
2641 sprintf(dev->name, "ppp%d", unit);
2642
2643 ret = register_netdev(dev);
2644 if (ret != 0) {
2645 unit_put(&pn->units_idr, unit);
2646 netdev_err(ppp->dev, "PPP: couldn't register device %s (%d)\n",
2647 dev->name, ret);
2648 goto out2;
2649 }
2650
2651 ppp->ppp_net = net;
2652
2653 atomic_inc(&ppp_unit_count);
2654 mutex_unlock(&pn->all_ppp_mutex);
2655
2656 *retp = 0;
2657 return ppp;
2658
2659 out2:
2660 mutex_unlock(&pn->all_ppp_mutex);
2661 free_netdev(dev);
2662 out1:
2663 *retp = ret;
2664 return NULL;
2665 }
2666
2667 /*
2668 * Initialize a ppp_file structure.
2669 */
2670 static void
2671 init_ppp_file(struct ppp_file *pf, int kind)
2672 {
2673 pf->kind = kind;
2674 skb_queue_head_init(&pf->xq);
2675 skb_queue_head_init(&pf->rq);
2676 atomic_set(&pf->refcnt, 1);
2677 init_waitqueue_head(&pf->rwait);
2678 }
2679
2680 /*
2681 * Take down a ppp interface unit - called when the owning file
2682 * (the one that created the unit) is closed or detached.
2683 */
2684 static void ppp_shutdown_interface(struct ppp *ppp)
2685 {
2686 struct ppp_net *pn;
2687
2688 pn = ppp_pernet(ppp->ppp_net);
2689 mutex_lock(&pn->all_ppp_mutex);
2690
2691 /* This will call dev_close() for us. */
2692 ppp_lock(ppp);
2693 if (!ppp->closing) {
2694 ppp->closing = 1;
2695 ppp_unlock(ppp);
2696 unregister_netdev(ppp->dev);
2697 unit_put(&pn->units_idr, ppp->file.index);
2698 } else
2699 ppp_unlock(ppp);
2700
2701 ppp->file.dead = 1;
2702 ppp->owner = NULL;
2703 wake_up_interruptible(&ppp->file.rwait);
2704
2705 mutex_unlock(&pn->all_ppp_mutex);
2706 }
2707
2708 /*
2709 * Free the memory used by a ppp unit. This is only called once
2710 * there are no channels connected to the unit and no file structs
2711 * that reference the unit.
2712 */
2713 static void ppp_destroy_interface(struct ppp *ppp)
2714 {
2715 atomic_dec(&ppp_unit_count);
2716
2717 if (!ppp->file.dead || ppp->n_channels) {
2718 /* "can't happen" */
2719 netdev_err(ppp->dev, "ppp: destroying ppp struct %p "
2720 "but dead=%d n_channels=%d !\n",
2721 ppp, ppp->file.dead, ppp->n_channels);
2722 return;
2723 }
2724
2725 ppp_ccp_closed(ppp);
2726 if (ppp->vj) {
2727 slhc_free(ppp->vj);
2728 ppp->vj = NULL;
2729 }
2730 skb_queue_purge(&ppp->file.xq);
2731 skb_queue_purge(&ppp->file.rq);
2732 #ifdef CONFIG_PPP_MULTILINK
2733 skb_queue_purge(&ppp->mrq);
2734 #endif /* CONFIG_PPP_MULTILINK */
2735 #ifdef CONFIG_PPP_FILTER
2736 kfree(ppp->pass_filter);
2737 ppp->pass_filter = NULL;
2738 kfree(ppp->active_filter);
2739 ppp->active_filter = NULL;
2740 #endif /* CONFIG_PPP_FILTER */
2741
2742 kfree_skb(ppp->xmit_pending);
2743
2744 free_netdev(ppp->dev);
2745 }
2746
2747 /*
2748 * Locate an existing ppp unit.
2749 * The caller should have locked the all_ppp_mutex.
2750 */
2751 static struct ppp *
2752 ppp_find_unit(struct ppp_net *pn, int unit)
2753 {
2754 return unit_find(&pn->units_idr, unit);
2755 }
2756
2757 /*
2758 * Locate an existing ppp channel.
2759 * The caller should have locked the all_channels_lock.
2760 * First we look in the new_channels list, then in the
2761 * all_channels list. If found in the new_channels list,
2762 * we move it to the all_channels list. This is for speed
2763 * when we have a lot of channels in use.
2764 */
2765 static struct channel *
2766 ppp_find_channel(struct ppp_net *pn, int unit)
2767 {
2768 struct channel *pch;
2769
2770 list_for_each_entry(pch, &pn->new_channels, list) {
2771 if (pch->file.index == unit) {
2772 list_move(&pch->list, &pn->all_channels);
2773 return pch;
2774 }
2775 }
2776
2777 list_for_each_entry(pch, &pn->all_channels, list) {
2778 if (pch->file.index == unit)
2779 return pch;
2780 }
2781
2782 return NULL;
2783 }
2784
2785 /*
2786 * Connect a PPP channel to a PPP interface unit.
2787 */
2788 static int
2789 ppp_connect_channel(struct channel *pch, int unit)
2790 {
2791 struct ppp *ppp;
2792 struct ppp_net *pn;
2793 int ret = -ENXIO;
2794 int hdrlen;
2795
2796 pn = ppp_pernet(pch->chan_net);
2797
2798 mutex_lock(&pn->all_ppp_mutex);
2799 ppp = ppp_find_unit(pn, unit);
2800 if (!ppp)
2801 goto out;
2802 write_lock_bh(&pch->upl);
2803 ret = -EINVAL;
2804 if (pch->ppp)
2805 goto outl;
2806
2807 ppp_lock(ppp);
2808 if (pch->file.hdrlen > ppp->file.hdrlen)
2809 ppp->file.hdrlen = pch->file.hdrlen;
2810 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2811 if (hdrlen > ppp->dev->hard_header_len)
2812 ppp->dev->hard_header_len = hdrlen;
2813 list_add_tail(&pch->clist, &ppp->channels);
2814 ++ppp->n_channels;
2815 pch->ppp = ppp;
2816 atomic_inc(&ppp->file.refcnt);
2817 ppp_unlock(ppp);
2818 ret = 0;
2819
2820 outl:
2821 write_unlock_bh(&pch->upl);
2822 out:
2823 mutex_unlock(&pn->all_ppp_mutex);
2824 return ret;
2825 }
2826
2827 /*
2828 * Disconnect a channel from its ppp unit.
2829 */
2830 static int
2831 ppp_disconnect_channel(struct channel *pch)
2832 {
2833 struct ppp *ppp;
2834 int err = -EINVAL;
2835
2836 write_lock_bh(&pch->upl);
2837 ppp = pch->ppp;
2838 pch->ppp = NULL;
2839 write_unlock_bh(&pch->upl);
2840 if (ppp) {
2841 /* remove it from the ppp unit's list */
2842 ppp_lock(ppp);
2843 list_del(&pch->clist);
2844 if (--ppp->n_channels == 0)
2845 wake_up_interruptible(&ppp->file.rwait);
2846 ppp_unlock(ppp);
2847 if (atomic_dec_and_test(&ppp->file.refcnt))
2848 ppp_destroy_interface(ppp);
2849 err = 0;
2850 }
2851 return err;
2852 }
2853
2854 /*
2855 * Free up the resources used by a ppp channel.
2856 */
2857 static void ppp_destroy_channel(struct channel *pch)
2858 {
2859 atomic_dec(&channel_count);
2860
2861 if (!pch->file.dead) {
2862 /* "can't happen" */
2863 pr_err("ppp: destroying undead channel %p !\n", pch);
2864 return;
2865 }
2866 skb_queue_purge(&pch->file.xq);
2867 skb_queue_purge(&pch->file.rq);
2868 kfree(pch);
2869 }
2870
2871 static void __exit ppp_cleanup(void)
2872 {
2873 /* should never happen */
2874 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2875 pr_err("PPP: removing module but units remain!\n");
2876 unregister_chrdev(PPP_MAJOR, "ppp");
2877 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
2878 class_destroy(ppp_class);
2879 unregister_pernet_device(&ppp_net_ops);
2880 }
2881
2882 /*
2883 * Units handling. Caller must protect concurrent access
2884 * by holding all_ppp_mutex
2885 */
2886
2887 static int __unit_alloc(struct idr *p, void *ptr, int n)
2888 {
2889 int unit, err;
2890
2891 again:
2892 if (!idr_pre_get(p, GFP_KERNEL)) {
2893 pr_err("PPP: No free memory for idr\n");
2894 return -ENOMEM;
2895 }
2896
2897 err = idr_get_new_above(p, ptr, n, &unit);
2898 if (err < 0) {
2899 if (err == -EAGAIN)
2900 goto again;
2901 return err;
2902 }
2903
2904 return unit;
2905 }
2906
2907 /* associate pointer with specified number */
2908 static int unit_set(struct idr *p, void *ptr, int n)
2909 {
2910 int unit;
2911
2912 unit = __unit_alloc(p, ptr, n);
2913 if (unit < 0)
2914 return unit;
2915 else if (unit != n) {
2916 idr_remove(p, unit);
2917 return -EINVAL;
2918 }
2919
2920 return unit;
2921 }
2922
2923 /* get new free unit number and associate pointer with it */
2924 static int unit_get(struct idr *p, void *ptr)
2925 {
2926 return __unit_alloc(p, ptr, 0);
2927 }
2928
2929 /* put unit number back to a pool */
2930 static void unit_put(struct idr *p, int n)
2931 {
2932 idr_remove(p, n);
2933 }
2934
2935 /* get pointer associated with the number */
2936 static void *unit_find(struct idr *p, int n)
2937 {
2938 return idr_find(p, n);
2939 }
2940
2941 /* Module/initialization stuff */
2942
2943 module_init(ppp_init);
2944 module_exit(ppp_cleanup);
2945
2946 EXPORT_SYMBOL(ppp_register_net_channel);
2947 EXPORT_SYMBOL(ppp_register_channel);
2948 EXPORT_SYMBOL(ppp_unregister_channel);
2949 EXPORT_SYMBOL(ppp_channel_index);
2950 EXPORT_SYMBOL(ppp_unit_number);
2951 EXPORT_SYMBOL(ppp_dev_name);
2952 EXPORT_SYMBOL(ppp_input);
2953 EXPORT_SYMBOL(ppp_input_error);
2954 EXPORT_SYMBOL(ppp_output_wakeup);
2955 EXPORT_SYMBOL(ppp_register_compressor);
2956 EXPORT_SYMBOL(ppp_unregister_compressor);
2957 MODULE_LICENSE("GPL");
2958 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
2959 MODULE_ALIAS("devname:ppp");
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