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Merge tag 'v3.3.7' into 3.3/master
[zen-stable.git] / drivers / net / ppp / ppp_generic.c
blob3ed983ce71af850860a291e98681745ade1bdfac
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 skb_queue_tail(&ppp->file.xq, skb);
972 ppp_xmit_process(ppp);
973 return NETDEV_TX_OK;
974
975 outf:
976 kfree_skb(skb);
977 ++dev->stats.tx_dropped;
978 return NETDEV_TX_OK;
979 }
980
981 static int
982 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
983 {
984 struct ppp *ppp = netdev_priv(dev);
985 int err = -EFAULT;
986 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
987 struct ppp_stats stats;
988 struct ppp_comp_stats cstats;
989 char *vers;
990
991 switch (cmd) {
992 case SIOCGPPPSTATS:
993 ppp_get_stats(ppp, &stats);
994 if (copy_to_user(addr, &stats, sizeof(stats)))
995 break;
996 err = 0;
997 break;
998
999 case SIOCGPPPCSTATS:
1000 memset(&cstats, 0, sizeof(cstats));
1001 if (ppp->xc_state)
1002 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
1003 if (ppp->rc_state)
1004 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
1005 if (copy_to_user(addr, &cstats, sizeof(cstats)))
1006 break;
1007 err = 0;
1008 break;
1009
1010 case SIOCGPPPVER:
1011 vers = PPP_VERSION;
1012 if (copy_to_user(addr, vers, strlen(vers) + 1))
1013 break;
1014 err = 0;
1015 break;
1016
1017 default:
1018 err = -EINVAL;
1019 }
1020
1021 return err;
1022 }
1023
1024 static const struct net_device_ops ppp_netdev_ops = {
1025 .ndo_start_xmit = ppp_start_xmit,
1026 .ndo_do_ioctl = ppp_net_ioctl,
1027 };
1028
1029 static void ppp_setup(struct net_device *dev)
1030 {
1031 dev->netdev_ops = &ppp_netdev_ops;
1032 dev->hard_header_len = PPP_HDRLEN;
1033 dev->mtu = PPP_MTU;
1034 dev->addr_len = 0;
1035 dev->tx_queue_len = 3;
1036 dev->type = ARPHRD_PPP;
1037 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1038 dev->features |= NETIF_F_NETNS_LOCAL;
1039 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1040 }
1041
1042 /*
1043 * Transmit-side routines.
1044 */
1045
1046 /*
1047 * Called to do any work queued up on the transmit side
1048 * that can now be done.
1049 */
1050 static void
1051 ppp_xmit_process(struct ppp *ppp)
1052 {
1053 struct sk_buff *skb;
1054
1055 ppp_xmit_lock(ppp);
1056 if (!ppp->closing) {
1057 ppp_push(ppp);
1058 while (!ppp->xmit_pending &&
1059 (skb = skb_dequeue(&ppp->file.xq)))
1060 ppp_send_frame(ppp, skb);
1061 /* If there's no work left to do, tell the core net
1062 code that we can accept some more. */
1063 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1064 netif_wake_queue(ppp->dev);
1065 else
1066 netif_stop_queue(ppp->dev);
1067 }
1068 ppp_xmit_unlock(ppp);
1069 }
1070
1071 static inline struct sk_buff *
1072 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1073 {
1074 struct sk_buff *new_skb;
1075 int len;
1076 int new_skb_size = ppp->dev->mtu +
1077 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1078 int compressor_skb_size = ppp->dev->mtu +
1079 ppp->xcomp->comp_extra + PPP_HDRLEN;
1080 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1081 if (!new_skb) {
1082 if (net_ratelimit())
1083 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n");
1084 return NULL;
1085 }
1086 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1087 skb_reserve(new_skb,
1088 ppp->dev->hard_header_len - PPP_HDRLEN);
1089
1090 /* compressor still expects A/C bytes in hdr */
1091 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1092 new_skb->data, skb->len + 2,
1093 compressor_skb_size);
1094 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1095 kfree_skb(skb);
1096 skb = new_skb;
1097 skb_put(skb, len);
1098 skb_pull(skb, 2); /* pull off A/C bytes */
1099 } else if (len == 0) {
1100 /* didn't compress, or CCP not up yet */
1101 kfree_skb(new_skb);
1102 new_skb = skb;
1103 } else {
1104 /*
1105 * (len < 0)
1106 * MPPE requires that we do not send unencrypted
1107 * frames. The compressor will return -1 if we
1108 * should drop the frame. We cannot simply test
1109 * the compress_proto because MPPE and MPPC share
1110 * the same number.
1111 */
1112 if (net_ratelimit())
1113 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n");
1114 kfree_skb(skb);
1115 kfree_skb(new_skb);
1116 new_skb = NULL;
1117 }
1118 return new_skb;
1119 }
1120
1121 /*
1122 * Compress and send a frame.
1123 * The caller should have locked the xmit path,
1124 * and xmit_pending should be 0.
1125 */
1126 static void
1127 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1128 {
1129 int proto = PPP_PROTO(skb);
1130 struct sk_buff *new_skb;
1131 int len;
1132 unsigned char *cp;
1133
1134 if (proto < 0x8000) {
1135 #ifdef CONFIG_PPP_FILTER
1136 /* check if we should pass this packet */
1137 /* the filter instructions are constructed assuming
1138 a four-byte PPP header on each packet */
1139 *skb_push(skb, 2) = 1;
1140 if (ppp->pass_filter &&
1141 sk_run_filter(skb, ppp->pass_filter) == 0) {
1142 if (ppp->debug & 1)
1143 netdev_printk(KERN_DEBUG, ppp->dev,
1144 "PPP: outbound frame "
1145 "not passed\n");
1146 kfree_skb(skb);
1147 return;
1148 }
1149 /* if this packet passes the active filter, record the time */
1150 if (!(ppp->active_filter &&
1151 sk_run_filter(skb, ppp->active_filter) == 0))
1152 ppp->last_xmit = jiffies;
1153 skb_pull(skb, 2);
1154 #else
1155 /* for data packets, record the time */
1156 ppp->last_xmit = jiffies;
1157 #endif /* CONFIG_PPP_FILTER */
1158 }
1159
1160 ++ppp->dev->stats.tx_packets;
1161 ppp->dev->stats.tx_bytes += skb->len - 2;
1162
1163 switch (proto) {
1164 case PPP_IP:
1165 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1166 break;
1167 /* try to do VJ TCP header compression */
1168 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1169 GFP_ATOMIC);
1170 if (!new_skb) {
1171 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n");
1172 goto drop;
1173 }
1174 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1175 cp = skb->data + 2;
1176 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1177 new_skb->data + 2, &cp,
1178 !(ppp->flags & SC_NO_TCP_CCID));
1179 if (cp == skb->data + 2) {
1180 /* didn't compress */
1181 kfree_skb(new_skb);
1182 } else {
1183 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1184 proto = PPP_VJC_COMP;
1185 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1186 } else {
1187 proto = PPP_VJC_UNCOMP;
1188 cp[0] = skb->data[2];
1189 }
1190 kfree_skb(skb);
1191 skb = new_skb;
1192 cp = skb_put(skb, len + 2);
1193 cp[0] = 0;
1194 cp[1] = proto;
1195 }
1196 break;
1197
1198 case PPP_CCP:
1199 /* peek at outbound CCP frames */
1200 ppp_ccp_peek(ppp, skb, 0);
1201 break;
1202 }
1203
1204 /* try to do packet compression */
1205 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state &&
1206 proto != PPP_LCP && proto != PPP_CCP) {
1207 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1208 if (net_ratelimit())
1209 netdev_err(ppp->dev,
1210 "ppp: compression required but "
1211 "down - pkt dropped.\n");
1212 goto drop;
1213 }
1214 skb = pad_compress_skb(ppp, skb);
1215 if (!skb)
1216 goto drop;
1217 }
1218
1219 /*
1220 * If we are waiting for traffic (demand dialling),
1221 * queue it up for pppd to receive.
1222 */
1223 if (ppp->flags & SC_LOOP_TRAFFIC) {
1224 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1225 goto drop;
1226 skb_queue_tail(&ppp->file.rq, skb);
1227 wake_up_interruptible(&ppp->file.rwait);
1228 return;
1229 }
1230
1231 ppp->xmit_pending = skb;
1232 ppp_push(ppp);
1233 return;
1234
1235 drop:
1236 kfree_skb(skb);
1237 ++ppp->dev->stats.tx_errors;
1238 }
1239
1240 /*
1241 * Try to send the frame in xmit_pending.
1242 * The caller should have the xmit path locked.
1243 */
1244 static void
1245 ppp_push(struct ppp *ppp)
1246 {
1247 struct list_head *list;
1248 struct channel *pch;
1249 struct sk_buff *skb = ppp->xmit_pending;
1250
1251 if (!skb)
1252 return;
1253
1254 list = &ppp->channels;
1255 if (list_empty(list)) {
1256 /* nowhere to send the packet, just drop it */
1257 ppp->xmit_pending = NULL;
1258 kfree_skb(skb);
1259 return;
1260 }
1261
1262 if ((ppp->flags & SC_MULTILINK) == 0) {
1263 /* not doing multilink: send it down the first channel */
1264 list = list->next;
1265 pch = list_entry(list, struct channel, clist);
1266
1267 spin_lock_bh(&pch->downl);
1268 if (pch->chan) {
1269 if (pch->chan->ops->start_xmit(pch->chan, skb))
1270 ppp->xmit_pending = NULL;
1271 } else {
1272 /* channel got unregistered */
1273 kfree_skb(skb);
1274 ppp->xmit_pending = NULL;
1275 }
1276 spin_unlock_bh(&pch->downl);
1277 return;
1278 }
1279
1280 #ifdef CONFIG_PPP_MULTILINK
1281 /* Multilink: fragment the packet over as many links
1282 as can take the packet at the moment. */
1283 if (!ppp_mp_explode(ppp, skb))
1284 return;
1285 #endif /* CONFIG_PPP_MULTILINK */
1286
1287 ppp->xmit_pending = NULL;
1288 kfree_skb(skb);
1289 }
1290
1291 #ifdef CONFIG_PPP_MULTILINK
1292 static bool mp_protocol_compress __read_mostly = true;
1293 module_param(mp_protocol_compress, bool, S_IRUGO | S_IWUSR);
1294 MODULE_PARM_DESC(mp_protocol_compress,
1295 "compress protocol id in multilink fragments");
1296
1297 /*
1298 * Divide a packet to be transmitted into fragments and
1299 * send them out the individual links.
1300 */
1301 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1302 {
1303 int len, totlen;
1304 int i, bits, hdrlen, mtu;
1305 int flen;
1306 int navail, nfree, nzero;
1307 int nbigger;
1308 int totspeed;
1309 int totfree;
1310 unsigned char *p, *q;
1311 struct list_head *list;
1312 struct channel *pch;
1313 struct sk_buff *frag;
1314 struct ppp_channel *chan;
1315
1316 totspeed = 0; /*total bitrate of the bundle*/
1317 nfree = 0; /* # channels which have no packet already queued */
1318 navail = 0; /* total # of usable channels (not deregistered) */
1319 nzero = 0; /* number of channels with zero speed associated*/
1320 totfree = 0; /*total # of channels available and
1321 *having no queued packets before
1322 *starting the fragmentation*/
1323
1324 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1325 i = 0;
1326 list_for_each_entry(pch, &ppp->channels, clist) {
1327 if (pch->chan) {
1328 pch->avail = 1;
1329 navail++;
1330 pch->speed = pch->chan->speed;
1331 } else {
1332 pch->avail = 0;
1333 }
1334 if (pch->avail) {
1335 if (skb_queue_empty(&pch->file.xq) ||
1336 !pch->had_frag) {
1337 if (pch->speed == 0)
1338 nzero++;
1339 else
1340 totspeed += pch->speed;
1341
1342 pch->avail = 2;
1343 ++nfree;
1344 ++totfree;
1345 }
1346 if (!pch->had_frag && i < ppp->nxchan)
1347 ppp->nxchan = i;
1348 }
1349 ++i;
1350 }
1351 /*
1352 * Don't start sending this packet unless at least half of
1353 * the channels are free. This gives much better TCP
1354 * performance if we have a lot of channels.
1355 */
1356 if (nfree == 0 || nfree < navail / 2)
1357 return 0; /* can't take now, leave it in xmit_pending */
1358
1359 /* Do protocol field compression */
1360 p = skb->data;
1361 len = skb->len;
1362 if (*p == 0 && mp_protocol_compress) {
1363 ++p;
1364 --len;
1365 }
1366
1367 totlen = len;
1368 nbigger = len % nfree;
1369
1370 /* skip to the channel after the one we last used
1371 and start at that one */
1372 list = &ppp->channels;
1373 for (i = 0; i < ppp->nxchan; ++i) {
1374 list = list->next;
1375 if (list == &ppp->channels) {
1376 i = 0;
1377 break;
1378 }
1379 }
1380
1381 /* create a fragment for each channel */
1382 bits = B;
1383 while (len > 0) {
1384 list = list->next;
1385 if (list == &ppp->channels) {
1386 i = 0;
1387 continue;
1388 }
1389 pch = list_entry(list, struct channel, clist);
1390 ++i;
1391 if (!pch->avail)
1392 continue;
1393
1394 /*
1395 * Skip this channel if it has a fragment pending already and
1396 * we haven't given a fragment to all of the free channels.
1397 */
1398 if (pch->avail == 1) {
1399 if (nfree > 0)
1400 continue;
1401 } else {
1402 pch->avail = 1;
1403 }
1404
1405 /* check the channel's mtu and whether it is still attached. */
1406 spin_lock_bh(&pch->downl);
1407 if (pch->chan == NULL) {
1408 /* can't use this channel, it's being deregistered */
1409 if (pch->speed == 0)
1410 nzero--;
1411 else
1412 totspeed -= pch->speed;
1413
1414 spin_unlock_bh(&pch->downl);
1415 pch->avail = 0;
1416 totlen = len;
1417 totfree--;
1418 nfree--;
1419 if (--navail == 0)
1420 break;
1421 continue;
1422 }
1423
1424 /*
1425 *if the channel speed is not set divide
1426 *the packet evenly among the free channels;
1427 *otherwise divide it according to the speed
1428 *of the channel we are going to transmit on
1429 */
1430 flen = len;
1431 if (nfree > 0) {
1432 if (pch->speed == 0) {
1433 flen = len/nfree;
1434 if (nbigger > 0) {
1435 flen++;
1436 nbigger--;
1437 }
1438 } else {
1439 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
1440 ((totspeed*totfree)/pch->speed)) - hdrlen;
1441 if (nbigger > 0) {
1442 flen += ((totfree - nzero)*pch->speed)/totspeed;
1443 nbigger -= ((totfree - nzero)*pch->speed)/
1444 totspeed;
1445 }
1446 }
1447 nfree--;
1448 }
1449
1450 /*
1451 *check if we are on the last channel or
1452 *we exceded the length of the data to
1453 *fragment
1454 */
1455 if ((nfree <= 0) || (flen > len))
1456 flen = len;
1457 /*
1458 *it is not worth to tx on slow channels:
1459 *in that case from the resulting flen according to the
1460 *above formula will be equal or less than zero.
1461 *Skip the channel in this case
1462 */
1463 if (flen <= 0) {
1464 pch->avail = 2;
1465 spin_unlock_bh(&pch->downl);
1466 continue;
1467 }
1468
1469 /*
1470 * hdrlen includes the 2-byte PPP protocol field, but the
1471 * MTU counts only the payload excluding the protocol field.
1472 * (RFC1661 Section 2)
1473 */
1474 mtu = pch->chan->mtu - (hdrlen - 2);
1475 if (mtu < 4)
1476 mtu = 4;
1477 if (flen > mtu)
1478 flen = mtu;
1479 if (flen == len)
1480 bits |= E;
1481 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1482 if (!frag)
1483 goto noskb;
1484 q = skb_put(frag, flen + hdrlen);
1485
1486 /* make the MP header */
1487 put_unaligned_be16(PPP_MP, q);
1488 if (ppp->flags & SC_MP_XSHORTSEQ) {
1489 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1490 q[3] = ppp->nxseq;
1491 } else {
1492 q[2] = bits;
1493 q[3] = ppp->nxseq >> 16;
1494 q[4] = ppp->nxseq >> 8;
1495 q[5] = ppp->nxseq;
1496 }
1497
1498 memcpy(q + hdrlen, p, flen);
1499
1500 /* try to send it down the channel */
1501 chan = pch->chan;
1502 if (!skb_queue_empty(&pch->file.xq) ||
1503 !chan->ops->start_xmit(chan, frag))
1504 skb_queue_tail(&pch->file.xq, frag);
1505 pch->had_frag = 1;
1506 p += flen;
1507 len -= flen;
1508 ++ppp->nxseq;
1509 bits = 0;
1510 spin_unlock_bh(&pch->downl);
1511 }
1512 ppp->nxchan = i;
1513
1514 return 1;
1515
1516 noskb:
1517 spin_unlock_bh(&pch->downl);
1518 if (ppp->debug & 1)
1519 netdev_err(ppp->dev, "PPP: no memory (fragment)\n");
1520 ++ppp->dev->stats.tx_errors;
1521 ++ppp->nxseq;
1522 return 1; /* abandon the frame */
1523 }
1524 #endif /* CONFIG_PPP_MULTILINK */
1525
1526 /*
1527 * Try to send data out on a channel.
1528 */
1529 static void
1530 ppp_channel_push(struct channel *pch)
1531 {
1532 struct sk_buff *skb;
1533 struct ppp *ppp;
1534
1535 spin_lock_bh(&pch->downl);
1536 if (pch->chan) {
1537 while (!skb_queue_empty(&pch->file.xq)) {
1538 skb = skb_dequeue(&pch->file.xq);
1539 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1540 /* put the packet back and try again later */
1541 skb_queue_head(&pch->file.xq, skb);
1542 break;
1543 }
1544 }
1545 } else {
1546 /* channel got deregistered */
1547 skb_queue_purge(&pch->file.xq);
1548 }
1549 spin_unlock_bh(&pch->downl);
1550 /* see if there is anything from the attached unit to be sent */
1551 if (skb_queue_empty(&pch->file.xq)) {
1552 read_lock_bh(&pch->upl);
1553 ppp = pch->ppp;
1554 if (ppp)
1555 ppp_xmit_process(ppp);
1556 read_unlock_bh(&pch->upl);
1557 }
1558 }
1559
1560 /*
1561 * Receive-side routines.
1562 */
1563
1564 struct ppp_mp_skb_parm {
1565 u32 sequence;
1566 u8 BEbits;
1567 };
1568 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb))
1569
1570 static inline void
1571 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1572 {
1573 ppp_recv_lock(ppp);
1574 if (!ppp->closing)
1575 ppp_receive_frame(ppp, skb, pch);
1576 else
1577 kfree_skb(skb);
1578 ppp_recv_unlock(ppp);
1579 }
1580
1581 void
1582 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1583 {
1584 struct channel *pch = chan->ppp;
1585 int proto;
1586
1587 if (!pch) {
1588 kfree_skb(skb);
1589 return;
1590 }
1591
1592 read_lock_bh(&pch->upl);
1593 if (!pskb_may_pull(skb, 2)) {
1594 kfree_skb(skb);
1595 if (pch->ppp) {
1596 ++pch->ppp->dev->stats.rx_length_errors;
1597 ppp_receive_error(pch->ppp);
1598 }
1599 goto done;
1600 }
1601
1602 proto = PPP_PROTO(skb);
1603 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1604 /* put it on the channel queue */
1605 skb_queue_tail(&pch->file.rq, skb);
1606 /* drop old frames if queue too long */
1607 while (pch->file.rq.qlen > PPP_MAX_RQLEN &&
1608 (skb = skb_dequeue(&pch->file.rq)))
1609 kfree_skb(skb);
1610 wake_up_interruptible(&pch->file.rwait);
1611 } else {
1612 ppp_do_recv(pch->ppp, skb, pch);
1613 }
1614
1615 done:
1616 read_unlock_bh(&pch->upl);
1617 }
1618
1619 /* Put a 0-length skb in the receive queue as an error indication */
1620 void
1621 ppp_input_error(struct ppp_channel *chan, int code)
1622 {
1623 struct channel *pch = chan->ppp;
1624 struct sk_buff *skb;
1625
1626 if (!pch)
1627 return;
1628
1629 read_lock_bh(&pch->upl);
1630 if (pch->ppp) {
1631 skb = alloc_skb(0, GFP_ATOMIC);
1632 if (skb) {
1633 skb->len = 0; /* probably unnecessary */
1634 skb->cb[0] = code;
1635 ppp_do_recv(pch->ppp, skb, pch);
1636 }
1637 }
1638 read_unlock_bh(&pch->upl);
1639 }
1640
1641 /*
1642 * We come in here to process a received frame.
1643 * The receive side of the ppp unit is locked.
1644 */
1645 static void
1646 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1647 {
1648 /* note: a 0-length skb is used as an error indication */
1649 if (skb->len > 0) {
1650 #ifdef CONFIG_PPP_MULTILINK
1651 /* XXX do channel-level decompression here */
1652 if (PPP_PROTO(skb) == PPP_MP)
1653 ppp_receive_mp_frame(ppp, skb, pch);
1654 else
1655 #endif /* CONFIG_PPP_MULTILINK */
1656 ppp_receive_nonmp_frame(ppp, skb);
1657 } else {
1658 kfree_skb(skb);
1659 ppp_receive_error(ppp);
1660 }
1661 }
1662
1663 static void
1664 ppp_receive_error(struct ppp *ppp)
1665 {
1666 ++ppp->dev->stats.rx_errors;
1667 if (ppp->vj)
1668 slhc_toss(ppp->vj);
1669 }
1670
1671 static void
1672 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1673 {
1674 struct sk_buff *ns;
1675 int proto, len, npi;
1676
1677 /*
1678 * Decompress the frame, if compressed.
1679 * Note that some decompressors need to see uncompressed frames
1680 * that come in as well as compressed frames.
1681 */
1682 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) &&
1683 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1684 skb = ppp_decompress_frame(ppp, skb);
1685
1686 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1687 goto err;
1688
1689 proto = PPP_PROTO(skb);
1690 switch (proto) {
1691 case PPP_VJC_COMP:
1692 /* decompress VJ compressed packets */
1693 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1694 goto err;
1695
1696 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1697 /* copy to a new sk_buff with more tailroom */
1698 ns = dev_alloc_skb(skb->len + 128);
1699 if (!ns) {
1700 netdev_err(ppp->dev, "PPP: no memory "
1701 "(VJ decomp)\n");
1702 goto err;
1703 }
1704 skb_reserve(ns, 2);
1705 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1706 kfree_skb(skb);
1707 skb = ns;
1708 }
1709 else
1710 skb->ip_summed = CHECKSUM_NONE;
1711
1712 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1713 if (len <= 0) {
1714 netdev_printk(KERN_DEBUG, ppp->dev,
1715 "PPP: VJ decompression error\n");
1716 goto err;
1717 }
1718 len += 2;
1719 if (len > skb->len)
1720 skb_put(skb, len - skb->len);
1721 else if (len < skb->len)
1722 skb_trim(skb, len);
1723 proto = PPP_IP;
1724 break;
1725
1726 case PPP_VJC_UNCOMP:
1727 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1728 goto err;
1729
1730 /* Until we fix the decompressor need to make sure
1731 * data portion is linear.
1732 */
1733 if (!pskb_may_pull(skb, skb->len))
1734 goto err;
1735
1736 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1737 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n");
1738 goto err;
1739 }
1740 proto = PPP_IP;
1741 break;
1742
1743 case PPP_CCP:
1744 ppp_ccp_peek(ppp, skb, 1);
1745 break;
1746 }
1747
1748 ++ppp->dev->stats.rx_packets;
1749 ppp->dev->stats.rx_bytes += skb->len - 2;
1750
1751 npi = proto_to_npindex(proto);
1752 if (npi < 0) {
1753 /* control or unknown frame - pass it to pppd */
1754 skb_queue_tail(&ppp->file.rq, skb);
1755 /* limit queue length by dropping old frames */
1756 while (ppp->file.rq.qlen > PPP_MAX_RQLEN &&
1757 (skb = skb_dequeue(&ppp->file.rq)))
1758 kfree_skb(skb);
1759 /* wake up any process polling or blocking on read */
1760 wake_up_interruptible(&ppp->file.rwait);
1761
1762 } else {
1763 /* network protocol frame - give it to the kernel */
1764
1765 #ifdef CONFIG_PPP_FILTER
1766 /* check if the packet passes the pass and active filters */
1767 /* the filter instructions are constructed assuming
1768 a four-byte PPP header on each packet */
1769 if (ppp->pass_filter || ppp->active_filter) {
1770 if (skb_cloned(skb) &&
1771 pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
1772 goto err;
1773
1774 *skb_push(skb, 2) = 0;
1775 if (ppp->pass_filter &&
1776 sk_run_filter(skb, ppp->pass_filter) == 0) {
1777 if (ppp->debug & 1)
1778 netdev_printk(KERN_DEBUG, ppp->dev,
1779 "PPP: inbound frame "
1780 "not passed\n");
1781 kfree_skb(skb);
1782 return;
1783 }
1784 if (!(ppp->active_filter &&
1785 sk_run_filter(skb, ppp->active_filter) == 0))
1786 ppp->last_recv = jiffies;
1787 __skb_pull(skb, 2);
1788 } else
1789 #endif /* CONFIG_PPP_FILTER */
1790 ppp->last_recv = jiffies;
1791
1792 if ((ppp->dev->flags & IFF_UP) == 0 ||
1793 ppp->npmode[npi] != NPMODE_PASS) {
1794 kfree_skb(skb);
1795 } else {
1796 /* chop off protocol */
1797 skb_pull_rcsum(skb, 2);
1798 skb->dev = ppp->dev;
1799 skb->protocol = htons(npindex_to_ethertype[npi]);
1800 skb_reset_mac_header(skb);
1801 netif_rx(skb);
1802 }
1803 }
1804 return;
1805
1806 err:
1807 kfree_skb(skb);
1808 ppp_receive_error(ppp);
1809 }
1810
1811 static struct sk_buff *
1812 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1813 {
1814 int proto = PPP_PROTO(skb);
1815 struct sk_buff *ns;
1816 int len;
1817
1818 /* Until we fix all the decompressor's need to make sure
1819 * data portion is linear.
1820 */
1821 if (!pskb_may_pull(skb, skb->len))
1822 goto err;
1823
1824 if (proto == PPP_COMP) {
1825 int obuff_size;
1826
1827 switch(ppp->rcomp->compress_proto) {
1828 case CI_MPPE:
1829 obuff_size = ppp->mru + PPP_HDRLEN + 1;
1830 break;
1831 default:
1832 obuff_size = ppp->mru + PPP_HDRLEN;
1833 break;
1834 }
1835
1836 ns = dev_alloc_skb(obuff_size);
1837 if (!ns) {
1838 netdev_err(ppp->dev, "ppp_decompress_frame: "
1839 "no memory\n");
1840 goto err;
1841 }
1842 /* the decompressor still expects the A/C bytes in the hdr */
1843 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1844 skb->len + 2, ns->data, obuff_size);
1845 if (len < 0) {
1846 /* Pass the compressed frame to pppd as an
1847 error indication. */
1848 if (len == DECOMP_FATALERROR)
1849 ppp->rstate |= SC_DC_FERROR;
1850 kfree_skb(ns);
1851 goto err;
1852 }
1853
1854 kfree_skb(skb);
1855 skb = ns;
1856 skb_put(skb, len);
1857 skb_pull(skb, 2); /* pull off the A/C bytes */
1858
1859 } else {
1860 /* Uncompressed frame - pass to decompressor so it
1861 can update its dictionary if necessary. */
1862 if (ppp->rcomp->incomp)
1863 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1864 skb->len + 2);
1865 }
1866
1867 return skb;
1868
1869 err:
1870 ppp->rstate |= SC_DC_ERROR;
1871 ppp_receive_error(ppp);
1872 return skb;
1873 }
1874
1875 #ifdef CONFIG_PPP_MULTILINK
1876 /*
1877 * Receive a multilink frame.
1878 * We put it on the reconstruction queue and then pull off
1879 * as many completed frames as we can.
1880 */
1881 static void
1882 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1883 {
1884 u32 mask, seq;
1885 struct channel *ch;
1886 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1887
1888 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
1889 goto err; /* no good, throw it away */
1890
1891 /* Decode sequence number and begin/end bits */
1892 if (ppp->flags & SC_MP_SHORTSEQ) {
1893 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1894 mask = 0xfff;
1895 } else {
1896 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1897 mask = 0xffffff;
1898 }
1899 PPP_MP_CB(skb)->BEbits = skb->data[2];
1900 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
1901
1902 /*
1903 * Do protocol ID decompression on the first fragment of each packet.
1904 */
1905 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1))
1906 *skb_push(skb, 1) = 0;
1907
1908 /*
1909 * Expand sequence number to 32 bits, making it as close
1910 * as possible to ppp->minseq.
1911 */
1912 seq |= ppp->minseq & ~mask;
1913 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
1914 seq += mask + 1;
1915 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
1916 seq -= mask + 1; /* should never happen */
1917 PPP_MP_CB(skb)->sequence = seq;
1918 pch->lastseq = seq;
1919
1920 /*
1921 * If this packet comes before the next one we were expecting,
1922 * drop it.
1923 */
1924 if (seq_before(seq, ppp->nextseq)) {
1925 kfree_skb(skb);
1926 ++ppp->dev->stats.rx_dropped;
1927 ppp_receive_error(ppp);
1928 return;
1929 }
1930
1931 /*
1932 * Reevaluate minseq, the minimum over all channels of the
1933 * last sequence number received on each channel. Because of
1934 * the increasing sequence number rule, we know that any fragment
1935 * before `minseq' which hasn't arrived is never going to arrive.
1936 * The list of channels can't change because we have the receive
1937 * side of the ppp unit locked.
1938 */
1939 list_for_each_entry(ch, &ppp->channels, clist) {
1940 if (seq_before(ch->lastseq, seq))
1941 seq = ch->lastseq;
1942 }
1943 if (seq_before(ppp->minseq, seq))
1944 ppp->minseq = seq;
1945
1946 /* Put the fragment on the reconstruction queue */
1947 ppp_mp_insert(ppp, skb);
1948
1949 /* If the queue is getting long, don't wait any longer for packets
1950 before the start of the queue. */
1951 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
1952 struct sk_buff *mskb = skb_peek(&ppp->mrq);
1953 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence))
1954 ppp->minseq = PPP_MP_CB(mskb)->sequence;
1955 }
1956
1957 /* Pull completed packets off the queue and receive them. */
1958 while ((skb = ppp_mp_reconstruct(ppp))) {
1959 if (pskb_may_pull(skb, 2))
1960 ppp_receive_nonmp_frame(ppp, skb);
1961 else {
1962 ++ppp->dev->stats.rx_length_errors;
1963 kfree_skb(skb);
1964 ppp_receive_error(ppp);
1965 }
1966 }
1967
1968 return;
1969
1970 err:
1971 kfree_skb(skb);
1972 ppp_receive_error(ppp);
1973 }
1974
1975 /*
1976 * Insert a fragment on the MP reconstruction queue.
1977 * The queue is ordered by increasing sequence number.
1978 */
1979 static void
1980 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
1981 {
1982 struct sk_buff *p;
1983 struct sk_buff_head *list = &ppp->mrq;
1984 u32 seq = PPP_MP_CB(skb)->sequence;
1985
1986 /* N.B. we don't need to lock the list lock because we have the
1987 ppp unit receive-side lock. */
1988 skb_queue_walk(list, p) {
1989 if (seq_before(seq, PPP_MP_CB(p)->sequence))
1990 break;
1991 }
1992 __skb_queue_before(list, p, skb);
1993 }
1994
1995 /*
1996 * Reconstruct a packet from the MP fragment queue.
1997 * We go through increasing sequence numbers until we find a
1998 * complete packet, or we get to the sequence number for a fragment
1999 * which hasn't arrived but might still do so.
2000 */
2001 static struct sk_buff *
2002 ppp_mp_reconstruct(struct ppp *ppp)
2003 {
2004 u32 seq = ppp->nextseq;
2005 u32 minseq = ppp->minseq;
2006 struct sk_buff_head *list = &ppp->mrq;
2007 struct sk_buff *p, *tmp;
2008 struct sk_buff *head, *tail;
2009 struct sk_buff *skb = NULL;
2010 int lost = 0, len = 0;
2011
2012 if (ppp->mrru == 0) /* do nothing until mrru is set */
2013 return NULL;
2014 head = list->next;
2015 tail = NULL;
2016 skb_queue_walk_safe(list, p, tmp) {
2017 again:
2018 if (seq_before(PPP_MP_CB(p)->sequence, seq)) {
2019 /* this can't happen, anyway ignore the skb */
2020 netdev_err(ppp->dev, "ppp_mp_reconstruct bad "
2021 "seq %u < %u\n",
2022 PPP_MP_CB(p)->sequence, seq);
2023 __skb_unlink(p, list);
2024 kfree_skb(p);
2025 continue;
2026 }
2027 if (PPP_MP_CB(p)->sequence != seq) {
2028 u32 oldseq;
2029 /* Fragment `seq' is missing. If it is after
2030 minseq, it might arrive later, so stop here. */
2031 if (seq_after(seq, minseq))
2032 break;
2033 /* Fragment `seq' is lost, keep going. */
2034 lost = 1;
2035 oldseq = seq;
2036 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)?
2037 minseq + 1: PPP_MP_CB(p)->sequence;
2038
2039 if (ppp->debug & 1)
2040 netdev_printk(KERN_DEBUG, ppp->dev,
2041 "lost frag %u..%u\n",
2042 oldseq, seq-1);
2043
2044 goto again;
2045 }
2046
2047 /*
2048 * At this point we know that all the fragments from
2049 * ppp->nextseq to seq are either present or lost.
2050 * Also, there are no complete packets in the queue
2051 * that have no missing fragments and end before this
2052 * fragment.
2053 */
2054
2055 /* B bit set indicates this fragment starts a packet */
2056 if (PPP_MP_CB(p)->BEbits & B) {
2057 head = p;
2058 lost = 0;
2059 len = 0;
2060 }
2061
2062 len += p->len;
2063
2064 /* Got a complete packet yet? */
2065 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) &&
2066 (PPP_MP_CB(head)->BEbits & B)) {
2067 if (len > ppp->mrru + 2) {
2068 ++ppp->dev->stats.rx_length_errors;
2069 netdev_printk(KERN_DEBUG, ppp->dev,
2070 "PPP: reconstructed packet"
2071 " is too long (%d)\n", len);
2072 } else {
2073 tail = p;
2074 break;
2075 }
2076 ppp->nextseq = seq + 1;
2077 }
2078
2079 /*
2080 * If this is the ending fragment of a packet,
2081 * and we haven't found a complete valid packet yet,
2082 * we can discard up to and including this fragment.
2083 */
2084 if (PPP_MP_CB(p)->BEbits & E) {
2085 struct sk_buff *tmp2;
2086
2087 skb_queue_reverse_walk_from_safe(list, p, tmp2) {
2088 if (ppp->debug & 1)
2089 netdev_printk(KERN_DEBUG, ppp->dev,
2090 "discarding frag %u\n",
2091 PPP_MP_CB(p)->sequence);
2092 __skb_unlink(p, list);
2093 kfree_skb(p);
2094 }
2095 head = skb_peek(list);
2096 if (!head)
2097 break;
2098 }
2099 ++seq;
2100 }
2101
2102 /* If we have a complete packet, copy it all into one skb. */
2103 if (tail != NULL) {
2104 /* If we have discarded any fragments,
2105 signal a receive error. */
2106 if (PPP_MP_CB(head)->sequence != ppp->nextseq) {
2107 skb_queue_walk_safe(list, p, tmp) {
2108 if (p == head)
2109 break;
2110 if (ppp->debug & 1)
2111 netdev_printk(KERN_DEBUG, ppp->dev,
2112 "discarding frag %u\n",
2113 PPP_MP_CB(p)->sequence);
2114 __skb_unlink(p, list);
2115 kfree_skb(p);
2116 }
2117
2118 if (ppp->debug & 1)
2119 netdev_printk(KERN_DEBUG, ppp->dev,
2120 " missed pkts %u..%u\n",
2121 ppp->nextseq,
2122 PPP_MP_CB(head)->sequence-1);
2123 ++ppp->dev->stats.rx_dropped;
2124 ppp_receive_error(ppp);
2125 }
2126
2127 skb = head;
2128 if (head != tail) {
2129 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list;
2130 p = skb_queue_next(list, head);
2131 __skb_unlink(skb, list);
2132 skb_queue_walk_from_safe(list, p, tmp) {
2133 __skb_unlink(p, list);
2134 *fragpp = p;
2135 p->next = NULL;
2136 fragpp = &p->next;
2137
2138 skb->len += p->len;
2139 skb->data_len += p->len;
2140 skb->truesize += p->len;
2141
2142 if (p == tail)
2143 break;
2144 }
2145 } else {
2146 __skb_unlink(skb, list);
2147 }
2148
2149 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1;
2150 }
2151
2152 return skb;
2153 }
2154 #endif /* CONFIG_PPP_MULTILINK */
2155
2156 /*
2157 * Channel interface.
2158 */
2159
2160 /* Create a new, unattached ppp channel. */
2161 int ppp_register_channel(struct ppp_channel *chan)
2162 {
2163 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2164 }
2165
2166 /* Create a new, unattached ppp channel for specified net. */
2167 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
2168 {
2169 struct channel *pch;
2170 struct ppp_net *pn;
2171
2172 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2173 if (!pch)
2174 return -ENOMEM;
2175
2176 pn = ppp_pernet(net);
2177
2178 pch->ppp = NULL;
2179 pch->chan = chan;
2180 pch->chan_net = net;
2181 chan->ppp = pch;
2182 init_ppp_file(&pch->file, CHANNEL);
2183 pch->file.hdrlen = chan->hdrlen;
2184 #ifdef CONFIG_PPP_MULTILINK
2185 pch->lastseq = -1;
2186 #endif /* CONFIG_PPP_MULTILINK */
2187 init_rwsem(&pch->chan_sem);
2188 spin_lock_init(&pch->downl);
2189 rwlock_init(&pch->upl);
2190
2191 spin_lock_bh(&pn->all_channels_lock);
2192 pch->file.index = ++pn->last_channel_index;
2193 list_add(&pch->list, &pn->new_channels);
2194 atomic_inc(&channel_count);
2195 spin_unlock_bh(&pn->all_channels_lock);
2196
2197 return 0;
2198 }
2199
2200 /*
2201 * Return the index of a channel.
2202 */
2203 int ppp_channel_index(struct ppp_channel *chan)
2204 {
2205 struct channel *pch = chan->ppp;
2206
2207 if (pch)
2208 return pch->file.index;
2209 return -1;
2210 }
2211
2212 /*
2213 * Return the PPP unit number to which a channel is connected.
2214 */
2215 int ppp_unit_number(struct ppp_channel *chan)
2216 {
2217 struct channel *pch = chan->ppp;
2218 int unit = -1;
2219
2220 if (pch) {
2221 read_lock_bh(&pch->upl);
2222 if (pch->ppp)
2223 unit = pch->ppp->file.index;
2224 read_unlock_bh(&pch->upl);
2225 }
2226 return unit;
2227 }
2228
2229 /*
2230 * Return the PPP device interface name of a channel.
2231 */
2232 char *ppp_dev_name(struct ppp_channel *chan)
2233 {
2234 struct channel *pch = chan->ppp;
2235 char *name = NULL;
2236
2237 if (pch) {
2238 read_lock_bh(&pch->upl);
2239 if (pch->ppp && pch->ppp->dev)
2240 name = pch->ppp->dev->name;
2241 read_unlock_bh(&pch->upl);
2242 }
2243 return name;
2244 }
2245
2246
2247 /*
2248 * Disconnect a channel from the generic layer.
2249 * This must be called in process context.
2250 */
2251 void
2252 ppp_unregister_channel(struct ppp_channel *chan)
2253 {
2254 struct channel *pch = chan->ppp;
2255 struct ppp_net *pn;
2256
2257 if (!pch)
2258 return; /* should never happen */
2259
2260 chan->ppp = NULL;
2261
2262 /*
2263 * This ensures that we have returned from any calls into the
2264 * the channel's start_xmit or ioctl routine before we proceed.
2265 */
2266 down_write(&pch->chan_sem);
2267 spin_lock_bh(&pch->downl);
2268 pch->chan = NULL;
2269 spin_unlock_bh(&pch->downl);
2270 up_write(&pch->chan_sem);
2271 ppp_disconnect_channel(pch);
2272
2273 pn = ppp_pernet(pch->chan_net);
2274 spin_lock_bh(&pn->all_channels_lock);
2275 list_del(&pch->list);
2276 spin_unlock_bh(&pn->all_channels_lock);
2277
2278 pch->file.dead = 1;
2279 wake_up_interruptible(&pch->file.rwait);
2280 if (atomic_dec_and_test(&pch->file.refcnt))
2281 ppp_destroy_channel(pch);
2282 }
2283
2284 /*
2285 * Callback from a channel when it can accept more to transmit.
2286 * This should be called at BH/softirq level, not interrupt level.
2287 */
2288 void
2289 ppp_output_wakeup(struct ppp_channel *chan)
2290 {
2291 struct channel *pch = chan->ppp;
2292
2293 if (!pch)
2294 return;
2295 ppp_channel_push(pch);
2296 }
2297
2298 /*
2299 * Compression control.
2300 */
2301
2302 /* Process the PPPIOCSCOMPRESS ioctl. */
2303 static int
2304 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2305 {
2306 int err;
2307 struct compressor *cp, *ocomp;
2308 struct ppp_option_data data;
2309 void *state, *ostate;
2310 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2311
2312 err = -EFAULT;
2313 if (copy_from_user(&data, (void __user *) arg, sizeof(data)) ||
2314 (data.length <= CCP_MAX_OPTION_LENGTH &&
2315 copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2316 goto out;
2317 err = -EINVAL;
2318 if (data.length > CCP_MAX_OPTION_LENGTH ||
2319 ccp_option[1] < 2 || ccp_option[1] > data.length)
2320 goto out;
2321
2322 cp = try_then_request_module(
2323 find_compressor(ccp_option[0]),
2324 "ppp-compress-%d", ccp_option[0]);
2325 if (!cp)
2326 goto out;
2327
2328 err = -ENOBUFS;
2329 if (data.transmit) {
2330 state = cp->comp_alloc(ccp_option, data.length);
2331 if (state) {
2332 ppp_xmit_lock(ppp);
2333 ppp->xstate &= ~SC_COMP_RUN;
2334 ocomp = ppp->xcomp;
2335 ostate = ppp->xc_state;
2336 ppp->xcomp = cp;
2337 ppp->xc_state = state;
2338 ppp_xmit_unlock(ppp);
2339 if (ostate) {
2340 ocomp->comp_free(ostate);
2341 module_put(ocomp->owner);
2342 }
2343 err = 0;
2344 } else
2345 module_put(cp->owner);
2346
2347 } else {
2348 state = cp->decomp_alloc(ccp_option, data.length);
2349 if (state) {
2350 ppp_recv_lock(ppp);
2351 ppp->rstate &= ~SC_DECOMP_RUN;
2352 ocomp = ppp->rcomp;
2353 ostate = ppp->rc_state;
2354 ppp->rcomp = cp;
2355 ppp->rc_state = state;
2356 ppp_recv_unlock(ppp);
2357 if (ostate) {
2358 ocomp->decomp_free(ostate);
2359 module_put(ocomp->owner);
2360 }
2361 err = 0;
2362 } else
2363 module_put(cp->owner);
2364 }
2365
2366 out:
2367 return err;
2368 }
2369
2370 /*
2371 * Look at a CCP packet and update our state accordingly.
2372 * We assume the caller has the xmit or recv path locked.
2373 */
2374 static void
2375 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2376 {
2377 unsigned char *dp;
2378 int len;
2379
2380 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2381 return; /* no header */
2382 dp = skb->data + 2;
2383
2384 switch (CCP_CODE(dp)) {
2385 case CCP_CONFREQ:
2386
2387 /* A ConfReq starts negotiation of compression
2388 * in one direction of transmission,
2389 * and hence brings it down...but which way?
2390 *
2391 * Remember:
2392 * A ConfReq indicates what the sender would like to receive
2393 */
2394 if(inbound)
2395 /* He is proposing what I should send */
2396 ppp->xstate &= ~SC_COMP_RUN;
2397 else
2398 /* I am proposing to what he should send */
2399 ppp->rstate &= ~SC_DECOMP_RUN;
2400
2401 break;
2402
2403 case CCP_TERMREQ:
2404 case CCP_TERMACK:
2405 /*
2406 * CCP is going down, both directions of transmission
2407 */
2408 ppp->rstate &= ~SC_DECOMP_RUN;
2409 ppp->xstate &= ~SC_COMP_RUN;
2410 break;
2411
2412 case CCP_CONFACK:
2413 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2414 break;
2415 len = CCP_LENGTH(dp);
2416 if (!pskb_may_pull(skb, len + 2))
2417 return; /* too short */
2418 dp += CCP_HDRLEN;
2419 len -= CCP_HDRLEN;
2420 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2421 break;
2422 if (inbound) {
2423 /* we will start receiving compressed packets */
2424 if (!ppp->rc_state)
2425 break;
2426 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2427 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2428 ppp->rstate |= SC_DECOMP_RUN;
2429 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2430 }
2431 } else {
2432 /* we will soon start sending compressed packets */
2433 if (!ppp->xc_state)
2434 break;
2435 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2436 ppp->file.index, 0, ppp->debug))
2437 ppp->xstate |= SC_COMP_RUN;
2438 }
2439 break;
2440
2441 case CCP_RESETACK:
2442 /* reset the [de]compressor */
2443 if ((ppp->flags & SC_CCP_UP) == 0)
2444 break;
2445 if (inbound) {
2446 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2447 ppp->rcomp->decomp_reset(ppp->rc_state);
2448 ppp->rstate &= ~SC_DC_ERROR;
2449 }
2450 } else {
2451 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2452 ppp->xcomp->comp_reset(ppp->xc_state);
2453 }
2454 break;
2455 }
2456 }
2457
2458 /* Free up compression resources. */
2459 static void
2460 ppp_ccp_closed(struct ppp *ppp)
2461 {
2462 void *xstate, *rstate;
2463 struct compressor *xcomp, *rcomp;
2464
2465 ppp_lock(ppp);
2466 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2467 ppp->xstate = 0;
2468 xcomp = ppp->xcomp;
2469 xstate = ppp->xc_state;
2470 ppp->xc_state = NULL;
2471 ppp->rstate = 0;
2472 rcomp = ppp->rcomp;
2473 rstate = ppp->rc_state;
2474 ppp->rc_state = NULL;
2475 ppp_unlock(ppp);
2476
2477 if (xstate) {
2478 xcomp->comp_free(xstate);
2479 module_put(xcomp->owner);
2480 }
2481 if (rstate) {
2482 rcomp->decomp_free(rstate);
2483 module_put(rcomp->owner);
2484 }
2485 }
2486
2487 /* List of compressors. */
2488 static LIST_HEAD(compressor_list);
2489 static DEFINE_SPINLOCK(compressor_list_lock);
2490
2491 struct compressor_entry {
2492 struct list_head list;
2493 struct compressor *comp;
2494 };
2495
2496 static struct compressor_entry *
2497 find_comp_entry(int proto)
2498 {
2499 struct compressor_entry *ce;
2500
2501 list_for_each_entry(ce, &compressor_list, list) {
2502 if (ce->comp->compress_proto == proto)
2503 return ce;
2504 }
2505 return NULL;
2506 }
2507
2508 /* Register a compressor */
2509 int
2510 ppp_register_compressor(struct compressor *cp)
2511 {
2512 struct compressor_entry *ce;
2513 int ret;
2514 spin_lock(&compressor_list_lock);
2515 ret = -EEXIST;
2516 if (find_comp_entry(cp->compress_proto))
2517 goto out;
2518 ret = -ENOMEM;
2519 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2520 if (!ce)
2521 goto out;
2522 ret = 0;
2523 ce->comp = cp;
2524 list_add(&ce->list, &compressor_list);
2525 out:
2526 spin_unlock(&compressor_list_lock);
2527 return ret;
2528 }
2529
2530 /* Unregister a compressor */
2531 void
2532 ppp_unregister_compressor(struct compressor *cp)
2533 {
2534 struct compressor_entry *ce;
2535
2536 spin_lock(&compressor_list_lock);
2537 ce = find_comp_entry(cp->compress_proto);
2538 if (ce && ce->comp == cp) {
2539 list_del(&ce->list);
2540 kfree(ce);
2541 }
2542 spin_unlock(&compressor_list_lock);
2543 }
2544
2545 /* Find a compressor. */
2546 static struct compressor *
2547 find_compressor(int type)
2548 {
2549 struct compressor_entry *ce;
2550 struct compressor *cp = NULL;
2551
2552 spin_lock(&compressor_list_lock);
2553 ce = find_comp_entry(type);
2554 if (ce) {
2555 cp = ce->comp;
2556 if (!try_module_get(cp->owner))
2557 cp = NULL;
2558 }
2559 spin_unlock(&compressor_list_lock);
2560 return cp;
2561 }
2562
2563 /*
2564 * Miscelleneous stuff.
2565 */
2566
2567 static void
2568 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2569 {
2570 struct slcompress *vj = ppp->vj;
2571
2572 memset(st, 0, sizeof(*st));
2573 st->p.ppp_ipackets = ppp->dev->stats.rx_packets;
2574 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2575 st->p.ppp_ibytes = ppp->dev->stats.rx_bytes;
2576 st->p.ppp_opackets = ppp->dev->stats.tx_packets;
2577 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2578 st->p.ppp_obytes = ppp->dev->stats.tx_bytes;
2579 if (!vj)
2580 return;
2581 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2582 st->vj.vjs_compressed = vj->sls_o_compressed;
2583 st->vj.vjs_searches = vj->sls_o_searches;
2584 st->vj.vjs_misses = vj->sls_o_misses;
2585 st->vj.vjs_errorin = vj->sls_i_error;
2586 st->vj.vjs_tossed = vj->sls_i_tossed;
2587 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2588 st->vj.vjs_compressedin = vj->sls_i_compressed;
2589 }
2590
2591 /*
2592 * Stuff for handling the lists of ppp units and channels
2593 * and for initialization.
2594 */
2595
2596 /*
2597 * Create a new ppp interface unit. Fails if it can't allocate memory
2598 * or if there is already a unit with the requested number.
2599 * unit == -1 means allocate a new number.
2600 */
2601 static struct ppp *
2602 ppp_create_interface(struct net *net, int unit, int *retp)
2603 {
2604 struct ppp *ppp;
2605 struct ppp_net *pn;
2606 struct net_device *dev = NULL;
2607 int ret = -ENOMEM;
2608 int i;
2609
2610 dev = alloc_netdev(sizeof(struct ppp), "", ppp_setup);
2611 if (!dev)
2612 goto out1;
2613
2614 pn = ppp_pernet(net);
2615
2616 ppp = netdev_priv(dev);
2617 ppp->dev = dev;
2618 ppp->mru = PPP_MRU;
2619 init_ppp_file(&ppp->file, INTERFACE);
2620 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2621 for (i = 0; i < NUM_NP; ++i)
2622 ppp->npmode[i] = NPMODE_PASS;
2623 INIT_LIST_HEAD(&ppp->channels);
2624 spin_lock_init(&ppp->rlock);
2625 spin_lock_init(&ppp->wlock);
2626 #ifdef CONFIG_PPP_MULTILINK
2627 ppp->minseq = -1;
2628 skb_queue_head_init(&ppp->mrq);
2629 #endif /* CONFIG_PPP_MULTILINK */
2630
2631 /*
2632 * drum roll: don't forget to set
2633 * the net device is belong to
2634 */
2635 dev_net_set(dev, net);
2636
2637 mutex_lock(&pn->all_ppp_mutex);
2638
2639 if (unit < 0) {
2640 unit = unit_get(&pn->units_idr, ppp);
2641 if (unit < 0) {
2642 ret = unit;
2643 goto out2;
2644 }
2645 } else {
2646 ret = -EEXIST;
2647 if (unit_find(&pn->units_idr, unit))
2648 goto out2; /* unit already exists */
2649 /*
2650 * if caller need a specified unit number
2651 * lets try to satisfy him, otherwise --
2652 * he should better ask us for new unit number
2653 *
2654 * NOTE: yes I know that returning EEXIST it's not
2655 * fair but at least pppd will ask us to allocate
2656 * new unit in this case so user is happy :)
2657 */
2658 unit = unit_set(&pn->units_idr, ppp, unit);
2659 if (unit < 0)
2660 goto out2;
2661 }
2662
2663 /* Initialize the new ppp unit */
2664 ppp->file.index = unit;
2665 sprintf(dev->name, "ppp%d", unit);
2666
2667 ret = register_netdev(dev);
2668 if (ret != 0) {
2669 unit_put(&pn->units_idr, unit);
2670 netdev_err(ppp->dev, "PPP: couldn't register device %s (%d)\n",
2671 dev->name, ret);
2672 goto out2;
2673 }
2674
2675 ppp->ppp_net = net;
2676
2677 atomic_inc(&ppp_unit_count);
2678 mutex_unlock(&pn->all_ppp_mutex);
2679
2680 *retp = 0;
2681 return ppp;
2682
2683 out2:
2684 mutex_unlock(&pn->all_ppp_mutex);
2685 free_netdev(dev);
2686 out1:
2687 *retp = ret;
2688 return NULL;
2689 }
2690
2691 /*
2692 * Initialize a ppp_file structure.
2693 */
2694 static void
2695 init_ppp_file(struct ppp_file *pf, int kind)
2696 {
2697 pf->kind = kind;
2698 skb_queue_head_init(&pf->xq);
2699 skb_queue_head_init(&pf->rq);
2700 atomic_set(&pf->refcnt, 1);
2701 init_waitqueue_head(&pf->rwait);
2702 }
2703
2704 /*
2705 * Take down a ppp interface unit - called when the owning file
2706 * (the one that created the unit) is closed or detached.
2707 */
2708 static void ppp_shutdown_interface(struct ppp *ppp)
2709 {
2710 struct ppp_net *pn;
2711
2712 pn = ppp_pernet(ppp->ppp_net);
2713 mutex_lock(&pn->all_ppp_mutex);
2714
2715 /* This will call dev_close() for us. */
2716 ppp_lock(ppp);
2717 if (!ppp->closing) {
2718 ppp->closing = 1;
2719 ppp_unlock(ppp);
2720 unregister_netdev(ppp->dev);
2721 unit_put(&pn->units_idr, ppp->file.index);
2722 } else
2723 ppp_unlock(ppp);
2724
2725 ppp->file.dead = 1;
2726 ppp->owner = NULL;
2727 wake_up_interruptible(&ppp->file.rwait);
2728
2729 mutex_unlock(&pn->all_ppp_mutex);
2730 }
2731
2732 /*
2733 * Free the memory used by a ppp unit. This is only called once
2734 * there are no channels connected to the unit and no file structs
2735 * that reference the unit.
2736 */
2737 static void ppp_destroy_interface(struct ppp *ppp)
2738 {
2739 atomic_dec(&ppp_unit_count);
2740
2741 if (!ppp->file.dead || ppp->n_channels) {
2742 /* "can't happen" */
2743 netdev_err(ppp->dev, "ppp: destroying ppp struct %p "
2744 "but dead=%d n_channels=%d !\n",
2745 ppp, ppp->file.dead, ppp->n_channels);
2746 return;
2747 }
2748
2749 ppp_ccp_closed(ppp);
2750 if (ppp->vj) {
2751 slhc_free(ppp->vj);
2752 ppp->vj = NULL;
2753 }
2754 skb_queue_purge(&ppp->file.xq);
2755 skb_queue_purge(&ppp->file.rq);
2756 #ifdef CONFIG_PPP_MULTILINK
2757 skb_queue_purge(&ppp->mrq);
2758 #endif /* CONFIG_PPP_MULTILINK */
2759 #ifdef CONFIG_PPP_FILTER
2760 kfree(ppp->pass_filter);
2761 ppp->pass_filter = NULL;
2762 kfree(ppp->active_filter);
2763 ppp->active_filter = NULL;
2764 #endif /* CONFIG_PPP_FILTER */
2765
2766 kfree_skb(ppp->xmit_pending);
2767
2768 free_netdev(ppp->dev);
2769 }
2770
2771 /*
2772 * Locate an existing ppp unit.
2773 * The caller should have locked the all_ppp_mutex.
2774 */
2775 static struct ppp *
2776 ppp_find_unit(struct ppp_net *pn, int unit)
2777 {
2778 return unit_find(&pn->units_idr, unit);
2779 }
2780
2781 /*
2782 * Locate an existing ppp channel.
2783 * The caller should have locked the all_channels_lock.
2784 * First we look in the new_channels list, then in the
2785 * all_channels list. If found in the new_channels list,
2786 * we move it to the all_channels list. This is for speed
2787 * when we have a lot of channels in use.
2788 */
2789 static struct channel *
2790 ppp_find_channel(struct ppp_net *pn, int unit)
2791 {
2792 struct channel *pch;
2793
2794 list_for_each_entry(pch, &pn->new_channels, list) {
2795 if (pch->file.index == unit) {
2796 list_move(&pch->list, &pn->all_channels);
2797 return pch;
2798 }
2799 }
2800
2801 list_for_each_entry(pch, &pn->all_channels, list) {
2802 if (pch->file.index == unit)
2803 return pch;
2804 }
2805
2806 return NULL;
2807 }
2808
2809 /*
2810 * Connect a PPP channel to a PPP interface unit.
2811 */
2812 static int
2813 ppp_connect_channel(struct channel *pch, int unit)
2814 {
2815 struct ppp *ppp;
2816 struct ppp_net *pn;
2817 int ret = -ENXIO;
2818 int hdrlen;
2819
2820 pn = ppp_pernet(pch->chan_net);
2821
2822 mutex_lock(&pn->all_ppp_mutex);
2823 ppp = ppp_find_unit(pn, unit);
2824 if (!ppp)
2825 goto out;
2826 write_lock_bh(&pch->upl);
2827 ret = -EINVAL;
2828 if (pch->ppp)
2829 goto outl;
2830
2831 ppp_lock(ppp);
2832 if (pch->file.hdrlen > ppp->file.hdrlen)
2833 ppp->file.hdrlen = pch->file.hdrlen;
2834 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2835 if (hdrlen > ppp->dev->hard_header_len)
2836 ppp->dev->hard_header_len = hdrlen;
2837 list_add_tail(&pch->clist, &ppp->channels);
2838 ++ppp->n_channels;
2839 pch->ppp = ppp;
2840 atomic_inc(&ppp->file.refcnt);
2841 ppp_unlock(ppp);
2842 ret = 0;
2843
2844 outl:
2845 write_unlock_bh(&pch->upl);
2846 out:
2847 mutex_unlock(&pn->all_ppp_mutex);
2848 return ret;
2849 }
2850
2851 /*
2852 * Disconnect a channel from its ppp unit.
2853 */
2854 static int
2855 ppp_disconnect_channel(struct channel *pch)
2856 {
2857 struct ppp *ppp;
2858 int err = -EINVAL;
2859
2860 write_lock_bh(&pch->upl);
2861 ppp = pch->ppp;
2862 pch->ppp = NULL;
2863 write_unlock_bh(&pch->upl);
2864 if (ppp) {
2865 /* remove it from the ppp unit's list */
2866 ppp_lock(ppp);
2867 list_del(&pch->clist);
2868 if (--ppp->n_channels == 0)
2869 wake_up_interruptible(&ppp->file.rwait);
2870 ppp_unlock(ppp);
2871 if (atomic_dec_and_test(&ppp->file.refcnt))
2872 ppp_destroy_interface(ppp);
2873 err = 0;
2874 }
2875 return err;
2876 }
2877
2878 /*
2879 * Free up the resources used by a ppp channel.
2880 */
2881 static void ppp_destroy_channel(struct channel *pch)
2882 {
2883 atomic_dec(&channel_count);
2884
2885 if (!pch->file.dead) {
2886 /* "can't happen" */
2887 pr_err("ppp: destroying undead channel %p !\n", pch);
2888 return;
2889 }
2890 skb_queue_purge(&pch->file.xq);
2891 skb_queue_purge(&pch->file.rq);
2892 kfree(pch);
2893 }
2894
2895 static void __exit ppp_cleanup(void)
2896 {
2897 /* should never happen */
2898 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2899 pr_err("PPP: removing module but units remain!\n");
2900 unregister_chrdev(PPP_MAJOR, "ppp");
2901 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
2902 class_destroy(ppp_class);
2903 unregister_pernet_device(&ppp_net_ops);
2904 }
2905
2906 /*
2907 * Units handling. Caller must protect concurrent access
2908 * by holding all_ppp_mutex
2909 */
2910
2911 static int __unit_alloc(struct idr *p, void *ptr, int n)
2912 {
2913 int unit, err;
2914
2915 again:
2916 if (!idr_pre_get(p, GFP_KERNEL)) {
2917 pr_err("PPP: No free memory for idr\n");
2918 return -ENOMEM;
2919 }
2920
2921 err = idr_get_new_above(p, ptr, n, &unit);
2922 if (err < 0) {
2923 if (err == -EAGAIN)
2924 goto again;
2925 return err;
2926 }
2927
2928 return unit;
2929 }
2930
2931 /* associate pointer with specified number */
2932 static int unit_set(struct idr *p, void *ptr, int n)
2933 {
2934 int unit;
2935
2936 unit = __unit_alloc(p, ptr, n);
2937 if (unit < 0)
2938 return unit;
2939 else if (unit != n) {
2940 idr_remove(p, unit);
2941 return -EINVAL;
2942 }
2943
2944 return unit;
2945 }
2946
2947 /* get new free unit number and associate pointer with it */
2948 static int unit_get(struct idr *p, void *ptr)
2949 {
2950 return __unit_alloc(p, ptr, 0);
2951 }
2952
2953 /* put unit number back to a pool */
2954 static void unit_put(struct idr *p, int n)
2955 {
2956 idr_remove(p, n);
2957 }
2958
2959 /* get pointer associated with the number */
2960 static void *unit_find(struct idr *p, int n)
2961 {
2962 return idr_find(p, n);
2963 }
2964
2965 /* Module/initialization stuff */
2966
2967 module_init(ppp_init);
2968 module_exit(ppp_cleanup);
2969
2970 EXPORT_SYMBOL(ppp_register_net_channel);
2971 EXPORT_SYMBOL(ppp_register_channel);
2972 EXPORT_SYMBOL(ppp_unregister_channel);
2973 EXPORT_SYMBOL(ppp_channel_index);
2974 EXPORT_SYMBOL(ppp_unit_number);
2975 EXPORT_SYMBOL(ppp_dev_name);
2976 EXPORT_SYMBOL(ppp_input);
2977 EXPORT_SYMBOL(ppp_input_error);
2978 EXPORT_SYMBOL(ppp_output_wakeup);
2979 EXPORT_SYMBOL(ppp_register_compressor);
2980 EXPORT_SYMBOL(ppp_unregister_compressor);
2981 MODULE_LICENSE("GPL");
2982 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
2983 MODULE_ALIAS("devname:ppp");