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befs: Validate length of long symbolic links.
[linux-2.6/kvm.git] / drivers / net / ppp_generic.c
blob10e5d985afa3f584cee497c91d5ceea3b81a014d
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 mtu = pch->chan->mtu - hdrlen;
1469 if (mtu < 4)
1470 mtu = 4;
1471 if (flen > mtu)
1472 flen = mtu;
1473 if (flen == len)
1474 bits |= E;
1475 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1476 if (!frag)
1477 goto noskb;
1478 q = skb_put(frag, flen + hdrlen);
1479
1480 /* make the MP header */
1481 put_unaligned_be16(PPP_MP, q);
1482 if (ppp->flags & SC_MP_XSHORTSEQ) {
1483 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1484 q[3] = ppp->nxseq;
1485 } else {
1486 q[2] = bits;
1487 q[3] = ppp->nxseq >> 16;
1488 q[4] = ppp->nxseq >> 8;
1489 q[5] = ppp->nxseq;
1490 }
1491
1492 memcpy(q + hdrlen, p, flen);
1493
1494 /* try to send it down the channel */
1495 chan = pch->chan;
1496 if (!skb_queue_empty(&pch->file.xq) ||
1497 !chan->ops->start_xmit(chan, frag))
1498 skb_queue_tail(&pch->file.xq, frag);
1499 pch->had_frag = 1;
1500 p += flen;
1501 len -= flen;
1502 ++ppp->nxseq;
1503 bits = 0;
1504 spin_unlock_bh(&pch->downl);
1505 }
1506 ppp->nxchan = i;
1507
1508 return 1;
1509
1510 noskb:
1511 spin_unlock_bh(&pch->downl);
1512 if (ppp->debug & 1)
1513 netdev_err(ppp->dev, "PPP: no memory (fragment)\n");
1514 ++ppp->dev->stats.tx_errors;
1515 ++ppp->nxseq;
1516 return 1; /* abandon the frame */
1517 }
1518 #endif /* CONFIG_PPP_MULTILINK */
1519
1520 /*
1521 * Try to send data out on a channel.
1522 */
1523 static void
1524 ppp_channel_push(struct channel *pch)
1525 {
1526 struct sk_buff *skb;
1527 struct ppp *ppp;
1528
1529 spin_lock_bh(&pch->downl);
1530 if (pch->chan) {
1531 while (!skb_queue_empty(&pch->file.xq)) {
1532 skb = skb_dequeue(&pch->file.xq);
1533 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1534 /* put the packet back and try again later */
1535 skb_queue_head(&pch->file.xq, skb);
1536 break;
1537 }
1538 }
1539 } else {
1540 /* channel got deregistered */
1541 skb_queue_purge(&pch->file.xq);
1542 }
1543 spin_unlock_bh(&pch->downl);
1544 /* see if there is anything from the attached unit to be sent */
1545 if (skb_queue_empty(&pch->file.xq)) {
1546 read_lock_bh(&pch->upl);
1547 ppp = pch->ppp;
1548 if (ppp)
1549 ppp_xmit_process(ppp);
1550 read_unlock_bh(&pch->upl);
1551 }
1552 }
1553
1554 /*
1555 * Receive-side routines.
1556 */
1557
1558 struct ppp_mp_skb_parm {
1559 u32 sequence;
1560 u8 BEbits;
1561 };
1562 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb))
1563
1564 static inline void
1565 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1566 {
1567 ppp_recv_lock(ppp);
1568 if (!ppp->closing)
1569 ppp_receive_frame(ppp, skb, pch);
1570 else
1571 kfree_skb(skb);
1572 ppp_recv_unlock(ppp);
1573 }
1574
1575 void
1576 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1577 {
1578 struct channel *pch = chan->ppp;
1579 int proto;
1580
1581 if (!pch) {
1582 kfree_skb(skb);
1583 return;
1584 }
1585
1586 read_lock_bh(&pch->upl);
1587 if (!pskb_may_pull(skb, 2)) {
1588 kfree_skb(skb);
1589 if (pch->ppp) {
1590 ++pch->ppp->dev->stats.rx_length_errors;
1591 ppp_receive_error(pch->ppp);
1592 }
1593 goto done;
1594 }
1595
1596 proto = PPP_PROTO(skb);
1597 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1598 /* put it on the channel queue */
1599 skb_queue_tail(&pch->file.rq, skb);
1600 /* drop old frames if queue too long */
1601 while (pch->file.rq.qlen > PPP_MAX_RQLEN &&
1602 (skb = skb_dequeue(&pch->file.rq)))
1603 kfree_skb(skb);
1604 wake_up_interruptible(&pch->file.rwait);
1605 } else {
1606 ppp_do_recv(pch->ppp, skb, pch);
1607 }
1608
1609 done:
1610 read_unlock_bh(&pch->upl);
1611 }
1612
1613 /* Put a 0-length skb in the receive queue as an error indication */
1614 void
1615 ppp_input_error(struct ppp_channel *chan, int code)
1616 {
1617 struct channel *pch = chan->ppp;
1618 struct sk_buff *skb;
1619
1620 if (!pch)
1621 return;
1622
1623 read_lock_bh(&pch->upl);
1624 if (pch->ppp) {
1625 skb = alloc_skb(0, GFP_ATOMIC);
1626 if (skb) {
1627 skb->len = 0; /* probably unnecessary */
1628 skb->cb[0] = code;
1629 ppp_do_recv(pch->ppp, skb, pch);
1630 }
1631 }
1632 read_unlock_bh(&pch->upl);
1633 }
1634
1635 /*
1636 * We come in here to process a received frame.
1637 * The receive side of the ppp unit is locked.
1638 */
1639 static void
1640 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1641 {
1642 /* note: a 0-length skb is used as an error indication */
1643 if (skb->len > 0) {
1644 #ifdef CONFIG_PPP_MULTILINK
1645 /* XXX do channel-level decompression here */
1646 if (PPP_PROTO(skb) == PPP_MP)
1647 ppp_receive_mp_frame(ppp, skb, pch);
1648 else
1649 #endif /* CONFIG_PPP_MULTILINK */
1650 ppp_receive_nonmp_frame(ppp, skb);
1651 } else {
1652 kfree_skb(skb);
1653 ppp_receive_error(ppp);
1654 }
1655 }
1656
1657 static void
1658 ppp_receive_error(struct ppp *ppp)
1659 {
1660 ++ppp->dev->stats.rx_errors;
1661 if (ppp->vj)
1662 slhc_toss(ppp->vj);
1663 }
1664
1665 static void
1666 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1667 {
1668 struct sk_buff *ns;
1669 int proto, len, npi;
1670
1671 /*
1672 * Decompress the frame, if compressed.
1673 * Note that some decompressors need to see uncompressed frames
1674 * that come in as well as compressed frames.
1675 */
1676 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) &&
1677 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1678 skb = ppp_decompress_frame(ppp, skb);
1679
1680 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1681 goto err;
1682
1683 proto = PPP_PROTO(skb);
1684 switch (proto) {
1685 case PPP_VJC_COMP:
1686 /* decompress VJ compressed packets */
1687 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1688 goto err;
1689
1690 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1691 /* copy to a new sk_buff with more tailroom */
1692 ns = dev_alloc_skb(skb->len + 128);
1693 if (!ns) {
1694 netdev_err(ppp->dev, "PPP: no memory "
1695 "(VJ decomp)\n");
1696 goto err;
1697 }
1698 skb_reserve(ns, 2);
1699 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1700 kfree_skb(skb);
1701 skb = ns;
1702 }
1703 else
1704 skb->ip_summed = CHECKSUM_NONE;
1705
1706 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1707 if (len <= 0) {
1708 netdev_printk(KERN_DEBUG, ppp->dev,
1709 "PPP: VJ decompression error\n");
1710 goto err;
1711 }
1712 len += 2;
1713 if (len > skb->len)
1714 skb_put(skb, len - skb->len);
1715 else if (len < skb->len)
1716 skb_trim(skb, len);
1717 proto = PPP_IP;
1718 break;
1719
1720 case PPP_VJC_UNCOMP:
1721 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1722 goto err;
1723
1724 /* Until we fix the decompressor need to make sure
1725 * data portion is linear.
1726 */
1727 if (!pskb_may_pull(skb, skb->len))
1728 goto err;
1729
1730 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1731 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n");
1732 goto err;
1733 }
1734 proto = PPP_IP;
1735 break;
1736
1737 case PPP_CCP:
1738 ppp_ccp_peek(ppp, skb, 1);
1739 break;
1740 }
1741
1742 ++ppp->dev->stats.rx_packets;
1743 ppp->dev->stats.rx_bytes += skb->len - 2;
1744
1745 npi = proto_to_npindex(proto);
1746 if (npi < 0) {
1747 /* control or unknown frame - pass it to pppd */
1748 skb_queue_tail(&ppp->file.rq, skb);
1749 /* limit queue length by dropping old frames */
1750 while (ppp->file.rq.qlen > PPP_MAX_RQLEN &&
1751 (skb = skb_dequeue(&ppp->file.rq)))
1752 kfree_skb(skb);
1753 /* wake up any process polling or blocking on read */
1754 wake_up_interruptible(&ppp->file.rwait);
1755
1756 } else {
1757 /* network protocol frame - give it to the kernel */
1758
1759 #ifdef CONFIG_PPP_FILTER
1760 /* check if the packet passes the pass and active filters */
1761 /* the filter instructions are constructed assuming
1762 a four-byte PPP header on each packet */
1763 if (ppp->pass_filter || ppp->active_filter) {
1764 if (skb_cloned(skb) &&
1765 pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
1766 goto err;
1767
1768 *skb_push(skb, 2) = 0;
1769 if (ppp->pass_filter &&
1770 sk_run_filter(skb, ppp->pass_filter) == 0) {
1771 if (ppp->debug & 1)
1772 netdev_printk(KERN_DEBUG, ppp->dev,
1773 "PPP: inbound frame "
1774 "not passed\n");
1775 kfree_skb(skb);
1776 return;
1777 }
1778 if (!(ppp->active_filter &&
1779 sk_run_filter(skb, ppp->active_filter) == 0))
1780 ppp->last_recv = jiffies;
1781 __skb_pull(skb, 2);
1782 } else
1783 #endif /* CONFIG_PPP_FILTER */
1784 ppp->last_recv = jiffies;
1785
1786 if ((ppp->dev->flags & IFF_UP) == 0 ||
1787 ppp->npmode[npi] != NPMODE_PASS) {
1788 kfree_skb(skb);
1789 } else {
1790 /* chop off protocol */
1791 skb_pull_rcsum(skb, 2);
1792 skb->dev = ppp->dev;
1793 skb->protocol = htons(npindex_to_ethertype[npi]);
1794 skb_reset_mac_header(skb);
1795 netif_rx(skb);
1796 }
1797 }
1798 return;
1799
1800 err:
1801 kfree_skb(skb);
1802 ppp_receive_error(ppp);
1803 }
1804
1805 static struct sk_buff *
1806 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1807 {
1808 int proto = PPP_PROTO(skb);
1809 struct sk_buff *ns;
1810 int len;
1811
1812 /* Until we fix all the decompressor's need to make sure
1813 * data portion is linear.
1814 */
1815 if (!pskb_may_pull(skb, skb->len))
1816 goto err;
1817
1818 if (proto == PPP_COMP) {
1819 int obuff_size;
1820
1821 switch(ppp->rcomp->compress_proto) {
1822 case CI_MPPE:
1823 obuff_size = ppp->mru + PPP_HDRLEN + 1;
1824 break;
1825 default:
1826 obuff_size = ppp->mru + PPP_HDRLEN;
1827 break;
1828 }
1829
1830 ns = dev_alloc_skb(obuff_size);
1831 if (!ns) {
1832 netdev_err(ppp->dev, "ppp_decompress_frame: "
1833 "no memory\n");
1834 goto err;
1835 }
1836 /* the decompressor still expects the A/C bytes in the hdr */
1837 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1838 skb->len + 2, ns->data, obuff_size);
1839 if (len < 0) {
1840 /* Pass the compressed frame to pppd as an
1841 error indication. */
1842 if (len == DECOMP_FATALERROR)
1843 ppp->rstate |= SC_DC_FERROR;
1844 kfree_skb(ns);
1845 goto err;
1846 }
1847
1848 kfree_skb(skb);
1849 skb = ns;
1850 skb_put(skb, len);
1851 skb_pull(skb, 2); /* pull off the A/C bytes */
1852
1853 } else {
1854 /* Uncompressed frame - pass to decompressor so it
1855 can update its dictionary if necessary. */
1856 if (ppp->rcomp->incomp)
1857 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1858 skb->len + 2);
1859 }
1860
1861 return skb;
1862
1863 err:
1864 ppp->rstate |= SC_DC_ERROR;
1865 ppp_receive_error(ppp);
1866 return skb;
1867 }
1868
1869 #ifdef CONFIG_PPP_MULTILINK
1870 /*
1871 * Receive a multilink frame.
1872 * We put it on the reconstruction queue and then pull off
1873 * as many completed frames as we can.
1874 */
1875 static void
1876 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1877 {
1878 u32 mask, seq;
1879 struct channel *ch;
1880 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1881
1882 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
1883 goto err; /* no good, throw it away */
1884
1885 /* Decode sequence number and begin/end bits */
1886 if (ppp->flags & SC_MP_SHORTSEQ) {
1887 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1888 mask = 0xfff;
1889 } else {
1890 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1891 mask = 0xffffff;
1892 }
1893 PPP_MP_CB(skb)->BEbits = skb->data[2];
1894 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
1895
1896 /*
1897 * Do protocol ID decompression on the first fragment of each packet.
1898 */
1899 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1))
1900 *skb_push(skb, 1) = 0;
1901
1902 /*
1903 * Expand sequence number to 32 bits, making it as close
1904 * as possible to ppp->minseq.
1905 */
1906 seq |= ppp->minseq & ~mask;
1907 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
1908 seq += mask + 1;
1909 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
1910 seq -= mask + 1; /* should never happen */
1911 PPP_MP_CB(skb)->sequence = seq;
1912 pch->lastseq = seq;
1913
1914 /*
1915 * If this packet comes before the next one we were expecting,
1916 * drop it.
1917 */
1918 if (seq_before(seq, ppp->nextseq)) {
1919 kfree_skb(skb);
1920 ++ppp->dev->stats.rx_dropped;
1921 ppp_receive_error(ppp);
1922 return;
1923 }
1924
1925 /*
1926 * Reevaluate minseq, the minimum over all channels of the
1927 * last sequence number received on each channel. Because of
1928 * the increasing sequence number rule, we know that any fragment
1929 * before `minseq' which hasn't arrived is never going to arrive.
1930 * The list of channels can't change because we have the receive
1931 * side of the ppp unit locked.
1932 */
1933 list_for_each_entry(ch, &ppp->channels, clist) {
1934 if (seq_before(ch->lastseq, seq))
1935 seq = ch->lastseq;
1936 }
1937 if (seq_before(ppp->minseq, seq))
1938 ppp->minseq = seq;
1939
1940 /* Put the fragment on the reconstruction queue */
1941 ppp_mp_insert(ppp, skb);
1942
1943 /* If the queue is getting long, don't wait any longer for packets
1944 before the start of the queue. */
1945 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
1946 struct sk_buff *mskb = skb_peek(&ppp->mrq);
1947 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence))
1948 ppp->minseq = PPP_MP_CB(mskb)->sequence;
1949 }
1950
1951 /* Pull completed packets off the queue and receive them. */
1952 while ((skb = ppp_mp_reconstruct(ppp))) {
1953 if (pskb_may_pull(skb, 2))
1954 ppp_receive_nonmp_frame(ppp, skb);
1955 else {
1956 ++ppp->dev->stats.rx_length_errors;
1957 kfree_skb(skb);
1958 ppp_receive_error(ppp);
1959 }
1960 }
1961
1962 return;
1963
1964 err:
1965 kfree_skb(skb);
1966 ppp_receive_error(ppp);
1967 }
1968
1969 /*
1970 * Insert a fragment on the MP reconstruction queue.
1971 * The queue is ordered by increasing sequence number.
1972 */
1973 static void
1974 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
1975 {
1976 struct sk_buff *p;
1977 struct sk_buff_head *list = &ppp->mrq;
1978 u32 seq = PPP_MP_CB(skb)->sequence;
1979
1980 /* N.B. we don't need to lock the list lock because we have the
1981 ppp unit receive-side lock. */
1982 skb_queue_walk(list, p) {
1983 if (seq_before(seq, PPP_MP_CB(p)->sequence))
1984 break;
1985 }
1986 __skb_queue_before(list, p, skb);
1987 }
1988
1989 /*
1990 * Reconstruct a packet from the MP fragment queue.
1991 * We go through increasing sequence numbers until we find a
1992 * complete packet, or we get to the sequence number for a fragment
1993 * which hasn't arrived but might still do so.
1994 */
1995 static struct sk_buff *
1996 ppp_mp_reconstruct(struct ppp *ppp)
1997 {
1998 u32 seq = ppp->nextseq;
1999 u32 minseq = ppp->minseq;
2000 struct sk_buff_head *list = &ppp->mrq;
2001 struct sk_buff *p, *tmp;
2002 struct sk_buff *head, *tail;
2003 struct sk_buff *skb = NULL;
2004 int lost = 0, len = 0;
2005
2006 if (ppp->mrru == 0) /* do nothing until mrru is set */
2007 return NULL;
2008 head = list->next;
2009 tail = NULL;
2010 skb_queue_walk_safe(list, p, tmp) {
2011 again:
2012 if (seq_before(PPP_MP_CB(p)->sequence, seq)) {
2013 /* this can't happen, anyway ignore the skb */
2014 netdev_err(ppp->dev, "ppp_mp_reconstruct bad "
2015 "seq %u < %u\n",
2016 PPP_MP_CB(p)->sequence, seq);
2017 __skb_unlink(p, list);
2018 kfree_skb(p);
2019 continue;
2020 }
2021 if (PPP_MP_CB(p)->sequence != seq) {
2022 /* Fragment `seq' is missing. If it is after
2023 minseq, it might arrive later, so stop here. */
2024 if (seq_after(seq, minseq))
2025 break;
2026 /* Fragment `seq' is lost, keep going. */
2027 lost = 1;
2028 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)?
2029 minseq + 1: PPP_MP_CB(p)->sequence;
2030 goto again;
2031 }
2032
2033 /*
2034 * At this point we know that all the fragments from
2035 * ppp->nextseq to seq are either present or lost.
2036 * Also, there are no complete packets in the queue
2037 * that have no missing fragments and end before this
2038 * fragment.
2039 */
2040
2041 /* B bit set indicates this fragment starts a packet */
2042 if (PPP_MP_CB(p)->BEbits & B) {
2043 head = p;
2044 lost = 0;
2045 len = 0;
2046 }
2047
2048 len += p->len;
2049
2050 /* Got a complete packet yet? */
2051 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) &&
2052 (PPP_MP_CB(head)->BEbits & B)) {
2053 if (len > ppp->mrru + 2) {
2054 ++ppp->dev->stats.rx_length_errors;
2055 netdev_printk(KERN_DEBUG, ppp->dev,
2056 "PPP: reconstructed packet"
2057 " is too long (%d)\n", len);
2058 } else {
2059 tail = p;
2060 break;
2061 }
2062 ppp->nextseq = seq + 1;
2063 }
2064
2065 /*
2066 * If this is the ending fragment of a packet,
2067 * and we haven't found a complete valid packet yet,
2068 * we can discard up to and including this fragment.
2069 */
2070 if (PPP_MP_CB(p)->BEbits & E) {
2071 struct sk_buff *tmp2;
2072
2073 skb_queue_reverse_walk_from_safe(list, p, tmp2) {
2074 __skb_unlink(p, list);
2075 kfree_skb(p);
2076 }
2077 head = skb_peek(list);
2078 if (!head)
2079 break;
2080 }
2081 ++seq;
2082 }
2083
2084 /* If we have a complete packet, copy it all into one skb. */
2085 if (tail != NULL) {
2086 /* If we have discarded any fragments,
2087 signal a receive error. */
2088 if (PPP_MP_CB(head)->sequence != ppp->nextseq) {
2089 if (ppp->debug & 1)
2090 netdev_printk(KERN_DEBUG, ppp->dev,
2091 " missed pkts %u..%u\n",
2092 ppp->nextseq,
2093 PPP_MP_CB(head)->sequence-1);
2094 ++ppp->dev->stats.rx_dropped;
2095 ppp_receive_error(ppp);
2096 }
2097
2098 skb = head;
2099 if (head != tail) {
2100 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list;
2101 p = skb_queue_next(list, head);
2102 __skb_unlink(skb, list);
2103 skb_queue_walk_from_safe(list, p, tmp) {
2104 __skb_unlink(p, list);
2105 *fragpp = p;
2106 p->next = NULL;
2107 fragpp = &p->next;
2108
2109 skb->len += p->len;
2110 skb->data_len += p->len;
2111 skb->truesize += p->len;
2112
2113 if (p == tail)
2114 break;
2115 }
2116 } else {
2117 __skb_unlink(skb, list);
2118 }
2119
2120 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1;
2121 }
2122
2123 return skb;
2124 }
2125 #endif /* CONFIG_PPP_MULTILINK */
2126
2127 /*
2128 * Channel interface.
2129 */
2130
2131 /* Create a new, unattached ppp channel. */
2132 int ppp_register_channel(struct ppp_channel *chan)
2133 {
2134 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2135 }
2136
2137 /* Create a new, unattached ppp channel for specified net. */
2138 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
2139 {
2140 struct channel *pch;
2141 struct ppp_net *pn;
2142
2143 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2144 if (!pch)
2145 return -ENOMEM;
2146
2147 pn = ppp_pernet(net);
2148
2149 pch->ppp = NULL;
2150 pch->chan = chan;
2151 pch->chan_net = net;
2152 chan->ppp = pch;
2153 init_ppp_file(&pch->file, CHANNEL);
2154 pch->file.hdrlen = chan->hdrlen;
2155 #ifdef CONFIG_PPP_MULTILINK
2156 pch->lastseq = -1;
2157 #endif /* CONFIG_PPP_MULTILINK */
2158 init_rwsem(&pch->chan_sem);
2159 spin_lock_init(&pch->downl);
2160 rwlock_init(&pch->upl);
2161
2162 spin_lock_bh(&pn->all_channels_lock);
2163 pch->file.index = ++pn->last_channel_index;
2164 list_add(&pch->list, &pn->new_channels);
2165 atomic_inc(&channel_count);
2166 spin_unlock_bh(&pn->all_channels_lock);
2167
2168 return 0;
2169 }
2170
2171 /*
2172 * Return the index of a channel.
2173 */
2174 int ppp_channel_index(struct ppp_channel *chan)
2175 {
2176 struct channel *pch = chan->ppp;
2177
2178 if (pch)
2179 return pch->file.index;
2180 return -1;
2181 }
2182
2183 /*
2184 * Return the PPP unit number to which a channel is connected.
2185 */
2186 int ppp_unit_number(struct ppp_channel *chan)
2187 {
2188 struct channel *pch = chan->ppp;
2189 int unit = -1;
2190
2191 if (pch) {
2192 read_lock_bh(&pch->upl);
2193 if (pch->ppp)
2194 unit = pch->ppp->file.index;
2195 read_unlock_bh(&pch->upl);
2196 }
2197 return unit;
2198 }
2199
2200 /*
2201 * Return the PPP device interface name of a channel.
2202 */
2203 char *ppp_dev_name(struct ppp_channel *chan)
2204 {
2205 struct channel *pch = chan->ppp;
2206 char *name = NULL;
2207
2208 if (pch) {
2209 read_lock_bh(&pch->upl);
2210 if (pch->ppp && pch->ppp->dev)
2211 name = pch->ppp->dev->name;
2212 read_unlock_bh(&pch->upl);
2213 }
2214 return name;
2215 }
2216
2217
2218 /*
2219 * Disconnect a channel from the generic layer.
2220 * This must be called in process context.
2221 */
2222 void
2223 ppp_unregister_channel(struct ppp_channel *chan)
2224 {
2225 struct channel *pch = chan->ppp;
2226 struct ppp_net *pn;
2227
2228 if (!pch)
2229 return; /* should never happen */
2230
2231 chan->ppp = NULL;
2232
2233 /*
2234 * This ensures that we have returned from any calls into the
2235 * the channel's start_xmit or ioctl routine before we proceed.
2236 */
2237 down_write(&pch->chan_sem);
2238 spin_lock_bh(&pch->downl);
2239 pch->chan = NULL;
2240 spin_unlock_bh(&pch->downl);
2241 up_write(&pch->chan_sem);
2242 ppp_disconnect_channel(pch);
2243
2244 pn = ppp_pernet(pch->chan_net);
2245 spin_lock_bh(&pn->all_channels_lock);
2246 list_del(&pch->list);
2247 spin_unlock_bh(&pn->all_channels_lock);
2248
2249 pch->file.dead = 1;
2250 wake_up_interruptible(&pch->file.rwait);
2251 if (atomic_dec_and_test(&pch->file.refcnt))
2252 ppp_destroy_channel(pch);
2253 }
2254
2255 /*
2256 * Callback from a channel when it can accept more to transmit.
2257 * This should be called at BH/softirq level, not interrupt level.
2258 */
2259 void
2260 ppp_output_wakeup(struct ppp_channel *chan)
2261 {
2262 struct channel *pch = chan->ppp;
2263
2264 if (!pch)
2265 return;
2266 ppp_channel_push(pch);
2267 }
2268
2269 /*
2270 * Compression control.
2271 */
2272
2273 /* Process the PPPIOCSCOMPRESS ioctl. */
2274 static int
2275 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2276 {
2277 int err;
2278 struct compressor *cp, *ocomp;
2279 struct ppp_option_data data;
2280 void *state, *ostate;
2281 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2282
2283 err = -EFAULT;
2284 if (copy_from_user(&data, (void __user *) arg, sizeof(data)) ||
2285 (data.length <= CCP_MAX_OPTION_LENGTH &&
2286 copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2287 goto out;
2288 err = -EINVAL;
2289 if (data.length > CCP_MAX_OPTION_LENGTH ||
2290 ccp_option[1] < 2 || ccp_option[1] > data.length)
2291 goto out;
2292
2293 cp = try_then_request_module(
2294 find_compressor(ccp_option[0]),
2295 "ppp-compress-%d", ccp_option[0]);
2296 if (!cp)
2297 goto out;
2298
2299 err = -ENOBUFS;
2300 if (data.transmit) {
2301 state = cp->comp_alloc(ccp_option, data.length);
2302 if (state) {
2303 ppp_xmit_lock(ppp);
2304 ppp->xstate &= ~SC_COMP_RUN;
2305 ocomp = ppp->xcomp;
2306 ostate = ppp->xc_state;
2307 ppp->xcomp = cp;
2308 ppp->xc_state = state;
2309 ppp_xmit_unlock(ppp);
2310 if (ostate) {
2311 ocomp->comp_free(ostate);
2312 module_put(ocomp->owner);
2313 }
2314 err = 0;
2315 } else
2316 module_put(cp->owner);
2317
2318 } else {
2319 state = cp->decomp_alloc(ccp_option, data.length);
2320 if (state) {
2321 ppp_recv_lock(ppp);
2322 ppp->rstate &= ~SC_DECOMP_RUN;
2323 ocomp = ppp->rcomp;
2324 ostate = ppp->rc_state;
2325 ppp->rcomp = cp;
2326 ppp->rc_state = state;
2327 ppp_recv_unlock(ppp);
2328 if (ostate) {
2329 ocomp->decomp_free(ostate);
2330 module_put(ocomp->owner);
2331 }
2332 err = 0;
2333 } else
2334 module_put(cp->owner);
2335 }
2336
2337 out:
2338 return err;
2339 }
2340
2341 /*
2342 * Look at a CCP packet and update our state accordingly.
2343 * We assume the caller has the xmit or recv path locked.
2344 */
2345 static void
2346 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2347 {
2348 unsigned char *dp;
2349 int len;
2350
2351 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2352 return; /* no header */
2353 dp = skb->data + 2;
2354
2355 switch (CCP_CODE(dp)) {
2356 case CCP_CONFREQ:
2357
2358 /* A ConfReq starts negotiation of compression
2359 * in one direction of transmission,
2360 * and hence brings it down...but which way?
2361 *
2362 * Remember:
2363 * A ConfReq indicates what the sender would like to receive
2364 */
2365 if(inbound)
2366 /* He is proposing what I should send */
2367 ppp->xstate &= ~SC_COMP_RUN;
2368 else
2369 /* I am proposing to what he should send */
2370 ppp->rstate &= ~SC_DECOMP_RUN;
2371
2372 break;
2373
2374 case CCP_TERMREQ:
2375 case CCP_TERMACK:
2376 /*
2377 * CCP is going down, both directions of transmission
2378 */
2379 ppp->rstate &= ~SC_DECOMP_RUN;
2380 ppp->xstate &= ~SC_COMP_RUN;
2381 break;
2382
2383 case CCP_CONFACK:
2384 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2385 break;
2386 len = CCP_LENGTH(dp);
2387 if (!pskb_may_pull(skb, len + 2))
2388 return; /* too short */
2389 dp += CCP_HDRLEN;
2390 len -= CCP_HDRLEN;
2391 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2392 break;
2393 if (inbound) {
2394 /* we will start receiving compressed packets */
2395 if (!ppp->rc_state)
2396 break;
2397 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2398 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2399 ppp->rstate |= SC_DECOMP_RUN;
2400 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2401 }
2402 } else {
2403 /* we will soon start sending compressed packets */
2404 if (!ppp->xc_state)
2405 break;
2406 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2407 ppp->file.index, 0, ppp->debug))
2408 ppp->xstate |= SC_COMP_RUN;
2409 }
2410 break;
2411
2412 case CCP_RESETACK:
2413 /* reset the [de]compressor */
2414 if ((ppp->flags & SC_CCP_UP) == 0)
2415 break;
2416 if (inbound) {
2417 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2418 ppp->rcomp->decomp_reset(ppp->rc_state);
2419 ppp->rstate &= ~SC_DC_ERROR;
2420 }
2421 } else {
2422 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2423 ppp->xcomp->comp_reset(ppp->xc_state);
2424 }
2425 break;
2426 }
2427 }
2428
2429 /* Free up compression resources. */
2430 static void
2431 ppp_ccp_closed(struct ppp *ppp)
2432 {
2433 void *xstate, *rstate;
2434 struct compressor *xcomp, *rcomp;
2435
2436 ppp_lock(ppp);
2437 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2438 ppp->xstate = 0;
2439 xcomp = ppp->xcomp;
2440 xstate = ppp->xc_state;
2441 ppp->xc_state = NULL;
2442 ppp->rstate = 0;
2443 rcomp = ppp->rcomp;
2444 rstate = ppp->rc_state;
2445 ppp->rc_state = NULL;
2446 ppp_unlock(ppp);
2447
2448 if (xstate) {
2449 xcomp->comp_free(xstate);
2450 module_put(xcomp->owner);
2451 }
2452 if (rstate) {
2453 rcomp->decomp_free(rstate);
2454 module_put(rcomp->owner);
2455 }
2456 }
2457
2458 /* List of compressors. */
2459 static LIST_HEAD(compressor_list);
2460 static DEFINE_SPINLOCK(compressor_list_lock);
2461
2462 struct compressor_entry {
2463 struct list_head list;
2464 struct compressor *comp;
2465 };
2466
2467 static struct compressor_entry *
2468 find_comp_entry(int proto)
2469 {
2470 struct compressor_entry *ce;
2471
2472 list_for_each_entry(ce, &compressor_list, list) {
2473 if (ce->comp->compress_proto == proto)
2474 return ce;
2475 }
2476 return NULL;
2477 }
2478
2479 /* Register a compressor */
2480 int
2481 ppp_register_compressor(struct compressor *cp)
2482 {
2483 struct compressor_entry *ce;
2484 int ret;
2485 spin_lock(&compressor_list_lock);
2486 ret = -EEXIST;
2487 if (find_comp_entry(cp->compress_proto))
2488 goto out;
2489 ret = -ENOMEM;
2490 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2491 if (!ce)
2492 goto out;
2493 ret = 0;
2494 ce->comp = cp;
2495 list_add(&ce->list, &compressor_list);
2496 out:
2497 spin_unlock(&compressor_list_lock);
2498 return ret;
2499 }
2500
2501 /* Unregister a compressor */
2502 void
2503 ppp_unregister_compressor(struct compressor *cp)
2504 {
2505 struct compressor_entry *ce;
2506
2507 spin_lock(&compressor_list_lock);
2508 ce = find_comp_entry(cp->compress_proto);
2509 if (ce && ce->comp == cp) {
2510 list_del(&ce->list);
2511 kfree(ce);
2512 }
2513 spin_unlock(&compressor_list_lock);
2514 }
2515
2516 /* Find a compressor. */
2517 static struct compressor *
2518 find_compressor(int type)
2519 {
2520 struct compressor_entry *ce;
2521 struct compressor *cp = NULL;
2522
2523 spin_lock(&compressor_list_lock);
2524 ce = find_comp_entry(type);
2525 if (ce) {
2526 cp = ce->comp;
2527 if (!try_module_get(cp->owner))
2528 cp = NULL;
2529 }
2530 spin_unlock(&compressor_list_lock);
2531 return cp;
2532 }
2533
2534 /*
2535 * Miscelleneous stuff.
2536 */
2537
2538 static void
2539 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2540 {
2541 struct slcompress *vj = ppp->vj;
2542
2543 memset(st, 0, sizeof(*st));
2544 st->p.ppp_ipackets = ppp->dev->stats.rx_packets;
2545 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2546 st->p.ppp_ibytes = ppp->dev->stats.rx_bytes;
2547 st->p.ppp_opackets = ppp->dev->stats.tx_packets;
2548 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2549 st->p.ppp_obytes = ppp->dev->stats.tx_bytes;
2550 if (!vj)
2551 return;
2552 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2553 st->vj.vjs_compressed = vj->sls_o_compressed;
2554 st->vj.vjs_searches = vj->sls_o_searches;
2555 st->vj.vjs_misses = vj->sls_o_misses;
2556 st->vj.vjs_errorin = vj->sls_i_error;
2557 st->vj.vjs_tossed = vj->sls_i_tossed;
2558 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2559 st->vj.vjs_compressedin = vj->sls_i_compressed;
2560 }
2561
2562 /*
2563 * Stuff for handling the lists of ppp units and channels
2564 * and for initialization.
2565 */
2566
2567 /*
2568 * Create a new ppp interface unit. Fails if it can't allocate memory
2569 * or if there is already a unit with the requested number.
2570 * unit == -1 means allocate a new number.
2571 */
2572 static struct ppp *
2573 ppp_create_interface(struct net *net, int unit, int *retp)
2574 {
2575 struct ppp *ppp;
2576 struct ppp_net *pn;
2577 struct net_device *dev = NULL;
2578 int ret = -ENOMEM;
2579 int i;
2580
2581 dev = alloc_netdev(sizeof(struct ppp), "", ppp_setup);
2582 if (!dev)
2583 goto out1;
2584
2585 pn = ppp_pernet(net);
2586
2587 ppp = netdev_priv(dev);
2588 ppp->dev = dev;
2589 ppp->mru = PPP_MRU;
2590 init_ppp_file(&ppp->file, INTERFACE);
2591 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2592 for (i = 0; i < NUM_NP; ++i)
2593 ppp->npmode[i] = NPMODE_PASS;
2594 INIT_LIST_HEAD(&ppp->channels);
2595 spin_lock_init(&ppp->rlock);
2596 spin_lock_init(&ppp->wlock);
2597 #ifdef CONFIG_PPP_MULTILINK
2598 ppp->minseq = -1;
2599 skb_queue_head_init(&ppp->mrq);
2600 #endif /* CONFIG_PPP_MULTILINK */
2601
2602 /*
2603 * drum roll: don't forget to set
2604 * the net device is belong to
2605 */
2606 dev_net_set(dev, net);
2607
2608 mutex_lock(&pn->all_ppp_mutex);
2609
2610 if (unit < 0) {
2611 unit = unit_get(&pn->units_idr, ppp);
2612 if (unit < 0) {
2613 ret = unit;
2614 goto out2;
2615 }
2616 } else {
2617 ret = -EEXIST;
2618 if (unit_find(&pn->units_idr, unit))
2619 goto out2; /* unit already exists */
2620 /*
2621 * if caller need a specified unit number
2622 * lets try to satisfy him, otherwise --
2623 * he should better ask us for new unit number
2624 *
2625 * NOTE: yes I know that returning EEXIST it's not
2626 * fair but at least pppd will ask us to allocate
2627 * new unit in this case so user is happy :)
2628 */
2629 unit = unit_set(&pn->units_idr, ppp, unit);
2630 if (unit < 0)
2631 goto out2;
2632 }
2633
2634 /* Initialize the new ppp unit */
2635 ppp->file.index = unit;
2636 sprintf(dev->name, "ppp%d", unit);
2637
2638 ret = register_netdev(dev);
2639 if (ret != 0) {
2640 unit_put(&pn->units_idr, unit);
2641 netdev_err(ppp->dev, "PPP: couldn't register device %s (%d)\n",
2642 dev->name, ret);
2643 goto out2;
2644 }
2645
2646 ppp->ppp_net = net;
2647
2648 atomic_inc(&ppp_unit_count);
2649 mutex_unlock(&pn->all_ppp_mutex);
2650
2651 *retp = 0;
2652 return ppp;
2653
2654 out2:
2655 mutex_unlock(&pn->all_ppp_mutex);
2656 free_netdev(dev);
2657 out1:
2658 *retp = ret;
2659 return NULL;
2660 }
2661
2662 /*
2663 * Initialize a ppp_file structure.
2664 */
2665 static void
2666 init_ppp_file(struct ppp_file *pf, int kind)
2667 {
2668 pf->kind = kind;
2669 skb_queue_head_init(&pf->xq);
2670 skb_queue_head_init(&pf->rq);
2671 atomic_set(&pf->refcnt, 1);
2672 init_waitqueue_head(&pf->rwait);
2673 }
2674
2675 /*
2676 * Take down a ppp interface unit - called when the owning file
2677 * (the one that created the unit) is closed or detached.
2678 */
2679 static void ppp_shutdown_interface(struct ppp *ppp)
2680 {
2681 struct ppp_net *pn;
2682
2683 pn = ppp_pernet(ppp->ppp_net);
2684 mutex_lock(&pn->all_ppp_mutex);
2685
2686 /* This will call dev_close() for us. */
2687 ppp_lock(ppp);
2688 if (!ppp->closing) {
2689 ppp->closing = 1;
2690 ppp_unlock(ppp);
2691 unregister_netdev(ppp->dev);
2692 unit_put(&pn->units_idr, ppp->file.index);
2693 } else
2694 ppp_unlock(ppp);
2695
2696 ppp->file.dead = 1;
2697 ppp->owner = NULL;
2698 wake_up_interruptible(&ppp->file.rwait);
2699
2700 mutex_unlock(&pn->all_ppp_mutex);
2701 }
2702
2703 /*
2704 * Free the memory used by a ppp unit. This is only called once
2705 * there are no channels connected to the unit and no file structs
2706 * that reference the unit.
2707 */
2708 static void ppp_destroy_interface(struct ppp *ppp)
2709 {
2710 atomic_dec(&ppp_unit_count);
2711
2712 if (!ppp->file.dead || ppp->n_channels) {
2713 /* "can't happen" */
2714 netdev_err(ppp->dev, "ppp: destroying ppp struct %p "
2715 "but dead=%d n_channels=%d !\n",
2716 ppp, ppp->file.dead, ppp->n_channels);
2717 return;
2718 }
2719
2720 ppp_ccp_closed(ppp);
2721 if (ppp->vj) {
2722 slhc_free(ppp->vj);
2723 ppp->vj = NULL;
2724 }
2725 skb_queue_purge(&ppp->file.xq);
2726 skb_queue_purge(&ppp->file.rq);
2727 #ifdef CONFIG_PPP_MULTILINK
2728 skb_queue_purge(&ppp->mrq);
2729 #endif /* CONFIG_PPP_MULTILINK */
2730 #ifdef CONFIG_PPP_FILTER
2731 kfree(ppp->pass_filter);
2732 ppp->pass_filter = NULL;
2733 kfree(ppp->active_filter);
2734 ppp->active_filter = NULL;
2735 #endif /* CONFIG_PPP_FILTER */
2736
2737 kfree_skb(ppp->xmit_pending);
2738
2739 free_netdev(ppp->dev);
2740 }
2741
2742 /*
2743 * Locate an existing ppp unit.
2744 * The caller should have locked the all_ppp_mutex.
2745 */
2746 static struct ppp *
2747 ppp_find_unit(struct ppp_net *pn, int unit)
2748 {
2749 return unit_find(&pn->units_idr, unit);
2750 }
2751
2752 /*
2753 * Locate an existing ppp channel.
2754 * The caller should have locked the all_channels_lock.
2755 * First we look in the new_channels list, then in the
2756 * all_channels list. If found in the new_channels list,
2757 * we move it to the all_channels list. This is for speed
2758 * when we have a lot of channels in use.
2759 */
2760 static struct channel *
2761 ppp_find_channel(struct ppp_net *pn, int unit)
2762 {
2763 struct channel *pch;
2764
2765 list_for_each_entry(pch, &pn->new_channels, list) {
2766 if (pch->file.index == unit) {
2767 list_move(&pch->list, &pn->all_channels);
2768 return pch;
2769 }
2770 }
2771
2772 list_for_each_entry(pch, &pn->all_channels, list) {
2773 if (pch->file.index == unit)
2774 return pch;
2775 }
2776
2777 return NULL;
2778 }
2779
2780 /*
2781 * Connect a PPP channel to a PPP interface unit.
2782 */
2783 static int
2784 ppp_connect_channel(struct channel *pch, int unit)
2785 {
2786 struct ppp *ppp;
2787 struct ppp_net *pn;
2788 int ret = -ENXIO;
2789 int hdrlen;
2790
2791 pn = ppp_pernet(pch->chan_net);
2792
2793 mutex_lock(&pn->all_ppp_mutex);
2794 ppp = ppp_find_unit(pn, unit);
2795 if (!ppp)
2796 goto out;
2797 write_lock_bh(&pch->upl);
2798 ret = -EINVAL;
2799 if (pch->ppp)
2800 goto outl;
2801
2802 ppp_lock(ppp);
2803 if (pch->file.hdrlen > ppp->file.hdrlen)
2804 ppp->file.hdrlen = pch->file.hdrlen;
2805 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2806 if (hdrlen > ppp->dev->hard_header_len)
2807 ppp->dev->hard_header_len = hdrlen;
2808 list_add_tail(&pch->clist, &ppp->channels);
2809 ++ppp->n_channels;
2810 pch->ppp = ppp;
2811 atomic_inc(&ppp->file.refcnt);
2812 ppp_unlock(ppp);
2813 ret = 0;
2814
2815 outl:
2816 write_unlock_bh(&pch->upl);
2817 out:
2818 mutex_unlock(&pn->all_ppp_mutex);
2819 return ret;
2820 }
2821
2822 /*
2823 * Disconnect a channel from its ppp unit.
2824 */
2825 static int
2826 ppp_disconnect_channel(struct channel *pch)
2827 {
2828 struct ppp *ppp;
2829 int err = -EINVAL;
2830
2831 write_lock_bh(&pch->upl);
2832 ppp = pch->ppp;
2833 pch->ppp = NULL;
2834 write_unlock_bh(&pch->upl);
2835 if (ppp) {
2836 /* remove it from the ppp unit's list */
2837 ppp_lock(ppp);
2838 list_del(&pch->clist);
2839 if (--ppp->n_channels == 0)
2840 wake_up_interruptible(&ppp->file.rwait);
2841 ppp_unlock(ppp);
2842 if (atomic_dec_and_test(&ppp->file.refcnt))
2843 ppp_destroy_interface(ppp);
2844 err = 0;
2845 }
2846 return err;
2847 }
2848
2849 /*
2850 * Free up the resources used by a ppp channel.
2851 */
2852 static void ppp_destroy_channel(struct channel *pch)
2853 {
2854 atomic_dec(&channel_count);
2855
2856 if (!pch->file.dead) {
2857 /* "can't happen" */
2858 pr_err("ppp: destroying undead channel %p !\n", pch);
2859 return;
2860 }
2861 skb_queue_purge(&pch->file.xq);
2862 skb_queue_purge(&pch->file.rq);
2863 kfree(pch);
2864 }
2865
2866 static void __exit ppp_cleanup(void)
2867 {
2868 /* should never happen */
2869 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2870 pr_err("PPP: removing module but units remain!\n");
2871 unregister_chrdev(PPP_MAJOR, "ppp");
2872 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
2873 class_destroy(ppp_class);
2874 unregister_pernet_device(&ppp_net_ops);
2875 }
2876
2877 /*
2878 * Units handling. Caller must protect concurrent access
2879 * by holding all_ppp_mutex
2880 */
2881
2882 static int __unit_alloc(struct idr *p, void *ptr, int n)
2883 {
2884 int unit, err;
2885
2886 again:
2887 if (!idr_pre_get(p, GFP_KERNEL)) {
2888 pr_err("PPP: No free memory for idr\n");
2889 return -ENOMEM;
2890 }
2891
2892 err = idr_get_new_above(p, ptr, n, &unit);
2893 if (err < 0) {
2894 if (err == -EAGAIN)
2895 goto again;
2896 return err;
2897 }
2898
2899 return unit;
2900 }
2901
2902 /* associate pointer with specified number */
2903 static int unit_set(struct idr *p, void *ptr, int n)
2904 {
2905 int unit;
2906
2907 unit = __unit_alloc(p, ptr, n);
2908 if (unit < 0)
2909 return unit;
2910 else if (unit != n) {
2911 idr_remove(p, unit);
2912 return -EINVAL;
2913 }
2914
2915 return unit;
2916 }
2917
2918 /* get new free unit number and associate pointer with it */
2919 static int unit_get(struct idr *p, void *ptr)
2920 {
2921 return __unit_alloc(p, ptr, 0);
2922 }
2923
2924 /* put unit number back to a pool */
2925 static void unit_put(struct idr *p, int n)
2926 {
2927 idr_remove(p, n);
2928 }
2929
2930 /* get pointer associated with the number */
2931 static void *unit_find(struct idr *p, int n)
2932 {
2933 return idr_find(p, n);
2934 }
2935
2936 /* Module/initialization stuff */
2937
2938 module_init(ppp_init);
2939 module_exit(ppp_cleanup);
2940
2941 EXPORT_SYMBOL(ppp_register_net_channel);
2942 EXPORT_SYMBOL(ppp_register_channel);
2943 EXPORT_SYMBOL(ppp_unregister_channel);
2944 EXPORT_SYMBOL(ppp_channel_index);
2945 EXPORT_SYMBOL(ppp_unit_number);
2946 EXPORT_SYMBOL(ppp_dev_name);
2947 EXPORT_SYMBOL(ppp_input);
2948 EXPORT_SYMBOL(ppp_input_error);
2949 EXPORT_SYMBOL(ppp_output_wakeup);
2950 EXPORT_SYMBOL(ppp_register_compressor);
2951 EXPORT_SYMBOL(ppp_unregister_compressor);
2952 MODULE_LICENSE("GPL");
2953 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
2954 MODULE_ALIAS("devname:ppp");
kernel-based virtual machine