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ext3: Add journal error check into ext3_delete_entry()
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / net / ppp_generic.c
blob89294b43c4a901f8ce927e1981ad317b95538f44
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 <net/slhc_vj.h>
50 #include <asm/atomic.h>
51
52 #include <linux/nsproxy.h>
53 #include <net/net_namespace.h>
54 #include <net/netns/generic.h>
55
56 #define PPP_VERSION "2.4.2"
57
58 /*
59 * Network protocols we support.
60 */
61 #define NP_IP 0 /* Internet Protocol V4 */
62 #define NP_IPV6 1 /* Internet Protocol V6 */
63 #define NP_IPX 2 /* IPX protocol */
64 #define NP_AT 3 /* Appletalk protocol */
65 #define NP_MPLS_UC 4 /* MPLS unicast */
66 #define NP_MPLS_MC 5 /* MPLS multicast */
67 #define NUM_NP 6 /* Number of NPs. */
68
69 #define MPHDRLEN 6 /* multilink protocol header length */
70 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */
71
72 /*
73 * An instance of /dev/ppp can be associated with either a ppp
74 * interface unit or a ppp channel. In both cases, file->private_data
75 * points to one of these.
76 */
77 struct ppp_file {
78 enum {
79 INTERFACE=1, CHANNEL
80 } kind;
81 struct sk_buff_head xq; /* pppd transmit queue */
82 struct sk_buff_head rq; /* receive queue for pppd */
83 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */
84 atomic_t refcnt; /* # refs (incl /dev/ppp attached) */
85 int hdrlen; /* space to leave for headers */
86 int index; /* interface unit / channel number */
87 int dead; /* unit/channel has been shut down */
88 };
89
90 #define PF_TO_X(pf, X) container_of(pf, X, file)
91
92 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
93 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
94
95 /*
96 * Data structure describing one ppp unit.
97 * A ppp unit corresponds to a ppp network interface device
98 * and represents a multilink bundle.
99 * It can have 0 or more ppp channels connected to it.
100 */
101 struct ppp {
102 struct ppp_file file; /* stuff for read/write/poll 0 */
103 struct file *owner; /* file that owns this unit 48 */
104 struct list_head channels; /* list of attached channels 4c */
105 int n_channels; /* how many channels are attached 54 */
106 spinlock_t rlock; /* lock for receive side 58 */
107 spinlock_t wlock; /* lock for transmit side 5c */
108 int mru; /* max receive unit 60 */
109 unsigned int flags; /* control bits 64 */
110 unsigned int xstate; /* transmit state bits 68 */
111 unsigned int rstate; /* receive state bits 6c */
112 int debug; /* debug flags 70 */
113 struct slcompress *vj; /* state for VJ header compression */
114 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
115 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
116 struct compressor *xcomp; /* transmit packet compressor 8c */
117 void *xc_state; /* its internal state 90 */
118 struct compressor *rcomp; /* receive decompressor 94 */
119 void *rc_state; /* its internal state 98 */
120 unsigned long last_xmit; /* jiffies when last pkt sent 9c */
121 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
122 struct net_device *dev; /* network interface device a4 */
123 int closing; /* is device closing down? a8 */
124 #ifdef CONFIG_PPP_MULTILINK
125 int nxchan; /* next channel to send something on */
126 u32 nxseq; /* next sequence number to send */
127 int mrru; /* MP: max reconst. receive unit */
128 u32 nextseq; /* MP: seq no of next packet */
129 u32 minseq; /* MP: min of most recent seqnos */
130 struct sk_buff_head mrq; /* MP: receive reconstruction queue */
131 #endif /* CONFIG_PPP_MULTILINK */
132 #ifdef CONFIG_PPP_FILTER
133 struct sock_filter *pass_filter; /* filter for packets to pass */
134 struct sock_filter *active_filter;/* filter for pkts to reset idle */
135 unsigned pass_len, active_len;
136 #endif /* CONFIG_PPP_FILTER */
137 struct net *ppp_net; /* the net we belong to */
138 };
139
140 /*
141 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
142 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
143 * SC_MUST_COMP
144 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
145 * Bits in xstate: SC_COMP_RUN
146 */
147 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
148 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
149 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
150
151 /*
152 * Private data structure for each channel.
153 * This includes the data structure used for multilink.
154 */
155 struct channel {
156 struct ppp_file file; /* stuff for read/write/poll */
157 struct list_head list; /* link in all/new_channels list */
158 struct ppp_channel *chan; /* public channel data structure */
159 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
160 spinlock_t downl; /* protects `chan', file.xq dequeue */
161 struct ppp *ppp; /* ppp unit we're connected to */
162 struct net *chan_net; /* the net channel belongs to */
163 struct list_head clist; /* link in list of channels per unit */
164 rwlock_t upl; /* protects `ppp' */
165 #ifdef CONFIG_PPP_MULTILINK
166 u8 avail; /* flag used in multilink stuff */
167 u8 had_frag; /* >= 1 fragments have been sent */
168 u32 lastseq; /* MP: last sequence # received */
169 int speed; /* speed of the corresponding ppp channel*/
170 #endif /* CONFIG_PPP_MULTILINK */
171 };
172
173 /*
174 * SMP locking issues:
175 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
176 * list and the ppp.n_channels field, you need to take both locks
177 * before you modify them.
178 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
179 * channel.downl.
180 */
181
182 static DEFINE_MUTEX(ppp_mutex);
183 static atomic_t ppp_unit_count = ATOMIC_INIT(0);
184 static atomic_t channel_count = ATOMIC_INIT(0);
185
186 /* per-net private data for this module */
187 static int ppp_net_id __read_mostly;
188 struct ppp_net {
189 /* units to ppp mapping */
190 struct idr units_idr;
191
192 /*
193 * all_ppp_mutex protects the units_idr mapping.
194 * It also ensures that finding a ppp unit in the units_idr
195 * map and updating its file.refcnt field is atomic.
196 */
197 struct mutex all_ppp_mutex;
198
199 /* channels */
200 struct list_head all_channels;
201 struct list_head new_channels;
202 int last_channel_index;
203
204 /*
205 * all_channels_lock protects all_channels and
206 * last_channel_index, and the atomicity of find
207 * a channel and updating its file.refcnt field.
208 */
209 spinlock_t all_channels_lock;
210 };
211
212 /* Get the PPP protocol number from a skb */
213 #define PPP_PROTO(skb) (((skb)->data[0] << 8) + (skb)->data[1])
214
215 /* We limit the length of ppp->file.rq to this (arbitrary) value */
216 #define PPP_MAX_RQLEN 32
217
218 /*
219 * Maximum number of multilink fragments queued up.
220 * This has to be large enough to cope with the maximum latency of
221 * the slowest channel relative to the others. Strictly it should
222 * depend on the number of channels and their characteristics.
223 */
224 #define PPP_MP_MAX_QLEN 128
225
226 /* Multilink header bits. */
227 #define B 0x80 /* this fragment begins a packet */
228 #define E 0x40 /* this fragment ends a packet */
229
230 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */
231 #define seq_before(a, b) ((s32)((a) - (b)) < 0)
232 #define seq_after(a, b) ((s32)((a) - (b)) > 0)
233
234 /* Prototypes. */
235 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
236 struct file *file, unsigned int cmd, unsigned long arg);
237 static void ppp_xmit_process(struct ppp *ppp);
238 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
239 static void ppp_push(struct ppp *ppp);
240 static void ppp_channel_push(struct channel *pch);
241 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
242 struct channel *pch);
243 static void ppp_receive_error(struct ppp *ppp);
244 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
245 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
246 struct sk_buff *skb);
247 #ifdef CONFIG_PPP_MULTILINK
248 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
249 struct channel *pch);
250 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
251 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
252 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
253 #endif /* CONFIG_PPP_MULTILINK */
254 static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
255 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
256 static void ppp_ccp_closed(struct ppp *ppp);
257 static struct compressor *find_compressor(int type);
258 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
259 static struct ppp *ppp_create_interface(struct net *net, int unit, int *retp);
260 static void init_ppp_file(struct ppp_file *pf, int kind);
261 static void ppp_shutdown_interface(struct ppp *ppp);
262 static void ppp_destroy_interface(struct ppp *ppp);
263 static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit);
264 static struct channel *ppp_find_channel(struct ppp_net *pn, int unit);
265 static int ppp_connect_channel(struct channel *pch, int unit);
266 static int ppp_disconnect_channel(struct channel *pch);
267 static void ppp_destroy_channel(struct channel *pch);
268 static int unit_get(struct idr *p, void *ptr);
269 static int unit_set(struct idr *p, void *ptr, int n);
270 static void unit_put(struct idr *p, int n);
271 static void *unit_find(struct idr *p, int n);
272
273 static struct class *ppp_class;
274
275 /* per net-namespace data */
276 static inline struct ppp_net *ppp_pernet(struct net *net)
277 {
278 BUG_ON(!net);
279
280 return net_generic(net, ppp_net_id);
281 }
282
283 /* Translates a PPP protocol number to a NP index (NP == network protocol) */
284 static inline int proto_to_npindex(int proto)
285 {
286 switch (proto) {
287 case PPP_IP:
288 return NP_IP;
289 case PPP_IPV6:
290 return NP_IPV6;
291 case PPP_IPX:
292 return NP_IPX;
293 case PPP_AT:
294 return NP_AT;
295 case PPP_MPLS_UC:
296 return NP_MPLS_UC;
297 case PPP_MPLS_MC:
298 return NP_MPLS_MC;
299 }
300 return -EINVAL;
301 }
302
303 /* Translates an NP index into a PPP protocol number */
304 static const int npindex_to_proto[NUM_NP] = {
305 PPP_IP,
306 PPP_IPV6,
307 PPP_IPX,
308 PPP_AT,
309 PPP_MPLS_UC,
310 PPP_MPLS_MC,
311 };
312
313 /* Translates an ethertype into an NP index */
314 static inline int ethertype_to_npindex(int ethertype)
315 {
316 switch (ethertype) {
317 case ETH_P_IP:
318 return NP_IP;
319 case ETH_P_IPV6:
320 return NP_IPV6;
321 case ETH_P_IPX:
322 return NP_IPX;
323 case ETH_P_PPPTALK:
324 case ETH_P_ATALK:
325 return NP_AT;
326 case ETH_P_MPLS_UC:
327 return NP_MPLS_UC;
328 case ETH_P_MPLS_MC:
329 return NP_MPLS_MC;
330 }
331 return -1;
332 }
333
334 /* Translates an NP index into an ethertype */
335 static const int npindex_to_ethertype[NUM_NP] = {
336 ETH_P_IP,
337 ETH_P_IPV6,
338 ETH_P_IPX,
339 ETH_P_PPPTALK,
340 ETH_P_MPLS_UC,
341 ETH_P_MPLS_MC,
342 };
343
344 /*
345 * Locking shorthand.
346 */
347 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
348 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
349 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
350 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
351 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
352 ppp_recv_lock(ppp); } while (0)
353 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
354 ppp_xmit_unlock(ppp); } while (0)
355
356 /*
357 * /dev/ppp device routines.
358 * The /dev/ppp device is used by pppd to control the ppp unit.
359 * It supports the read, write, ioctl and poll functions.
360 * Open instances of /dev/ppp can be in one of three states:
361 * unattached, attached to a ppp unit, or attached to a ppp channel.
362 */
363 static int ppp_open(struct inode *inode, struct file *file)
364 {
365 /*
366 * This could (should?) be enforced by the permissions on /dev/ppp.
367 */
368 if (!capable(CAP_NET_ADMIN))
369 return -EPERM;
370 return 0;
371 }
372
373 static int ppp_release(struct inode *unused, struct file *file)
374 {
375 struct ppp_file *pf = file->private_data;
376 struct ppp *ppp;
377
378 if (pf) {
379 file->private_data = NULL;
380 if (pf->kind == INTERFACE) {
381 ppp = PF_TO_PPP(pf);
382 if (file == ppp->owner)
383 ppp_shutdown_interface(ppp);
384 }
385 if (atomic_dec_and_test(&pf->refcnt)) {
386 switch (pf->kind) {
387 case INTERFACE:
388 ppp_destroy_interface(PF_TO_PPP(pf));
389 break;
390 case CHANNEL:
391 ppp_destroy_channel(PF_TO_CHANNEL(pf));
392 break;
393 }
394 }
395 }
396 return 0;
397 }
398
399 static ssize_t ppp_read(struct file *file, char __user *buf,
400 size_t count, loff_t *ppos)
401 {
402 struct ppp_file *pf = file->private_data;
403 DECLARE_WAITQUEUE(wait, current);
404 ssize_t ret;
405 struct sk_buff *skb = NULL;
406 struct iovec iov;
407
408 ret = count;
409
410 if (!pf)
411 return -ENXIO;
412 add_wait_queue(&pf->rwait, &wait);
413 for (;;) {
414 set_current_state(TASK_INTERRUPTIBLE);
415 skb = skb_dequeue(&pf->rq);
416 if (skb)
417 break;
418 ret = 0;
419 if (pf->dead)
420 break;
421 if (pf->kind == INTERFACE) {
422 /*
423 * Return 0 (EOF) on an interface that has no
424 * channels connected, unless it is looping
425 * network traffic (demand mode).
426 */
427 struct ppp *ppp = PF_TO_PPP(pf);
428 if (ppp->n_channels == 0 &&
429 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
430 break;
431 }
432 ret = -EAGAIN;
433 if (file->f_flags & O_NONBLOCK)
434 break;
435 ret = -ERESTARTSYS;
436 if (signal_pending(current))
437 break;
438 schedule();
439 }
440 set_current_state(TASK_RUNNING);
441 remove_wait_queue(&pf->rwait, &wait);
442
443 if (!skb)
444 goto out;
445
446 ret = -EOVERFLOW;
447 if (skb->len > count)
448 goto outf;
449 ret = -EFAULT;
450 iov.iov_base = buf;
451 iov.iov_len = count;
452 if (skb_copy_datagram_iovec(skb, 0, &iov, skb->len))
453 goto outf;
454 ret = skb->len;
455
456 outf:
457 kfree_skb(skb);
458 out:
459 return ret;
460 }
461
462 static ssize_t ppp_write(struct file *file, const char __user *buf,
463 size_t count, loff_t *ppos)
464 {
465 struct ppp_file *pf = file->private_data;
466 struct sk_buff *skb;
467 ssize_t ret;
468
469 if (!pf)
470 return -ENXIO;
471 ret = -ENOMEM;
472 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
473 if (!skb)
474 goto out;
475 skb_reserve(skb, pf->hdrlen);
476 ret = -EFAULT;
477 if (copy_from_user(skb_put(skb, count), buf, count)) {
478 kfree_skb(skb);
479 goto out;
480 }
481
482 skb_queue_tail(&pf->xq, skb);
483
484 switch (pf->kind) {
485 case INTERFACE:
486 ppp_xmit_process(PF_TO_PPP(pf));
487 break;
488 case CHANNEL:
489 ppp_channel_push(PF_TO_CHANNEL(pf));
490 break;
491 }
492
493 ret = count;
494
495 out:
496 return ret;
497 }
498
499 /* No kernel lock - fine */
500 static unsigned int ppp_poll(struct file *file, poll_table *wait)
501 {
502 struct ppp_file *pf = file->private_data;
503 unsigned int mask;
504
505 if (!pf)
506 return 0;
507 poll_wait(file, &pf->rwait, wait);
508 mask = POLLOUT | POLLWRNORM;
509 if (skb_peek(&pf->rq))
510 mask |= POLLIN | POLLRDNORM;
511 if (pf->dead)
512 mask |= POLLHUP;
513 else if (pf->kind == INTERFACE) {
514 /* see comment in ppp_read */
515 struct ppp *ppp = PF_TO_PPP(pf);
516 if (ppp->n_channels == 0 &&
517 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
518 mask |= POLLIN | POLLRDNORM;
519 }
520
521 return mask;
522 }
523
524 #ifdef CONFIG_PPP_FILTER
525 static int get_filter(void __user *arg, struct sock_filter **p)
526 {
527 struct sock_fprog uprog;
528 struct sock_filter *code = NULL;
529 int len, err;
530
531 if (copy_from_user(&uprog, arg, sizeof(uprog)))
532 return -EFAULT;
533
534 if (!uprog.len) {
535 *p = NULL;
536 return 0;
537 }
538
539 len = uprog.len * sizeof(struct sock_filter);
540 code = memdup_user(uprog.filter, len);
541 if (IS_ERR(code))
542 return PTR_ERR(code);
543
544 err = sk_chk_filter(code, uprog.len);
545 if (err) {
546 kfree(code);
547 return err;
548 }
549
550 *p = code;
551 return uprog.len;
552 }
553 #endif /* CONFIG_PPP_FILTER */
554
555 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
556 {
557 struct ppp_file *pf = file->private_data;
558 struct ppp *ppp;
559 int err = -EFAULT, val, val2, i;
560 struct ppp_idle idle;
561 struct npioctl npi;
562 int unit, cflags;
563 struct slcompress *vj;
564 void __user *argp = (void __user *)arg;
565 int __user *p = argp;
566
567 if (!pf)
568 return ppp_unattached_ioctl(current->nsproxy->net_ns,
569 pf, file, cmd, arg);
570
571 if (cmd == PPPIOCDETACH) {
572 /*
573 * We have to be careful here... if the file descriptor
574 * has been dup'd, we could have another process in the
575 * middle of a poll using the same file *, so we had
576 * better not free the interface data structures -
577 * instead we fail the ioctl. Even in this case, we
578 * shut down the interface if we are the owner of it.
579 * Actually, we should get rid of PPPIOCDETACH, userland
580 * (i.e. pppd) could achieve the same effect by closing
581 * this fd and reopening /dev/ppp.
582 */
583 err = -EINVAL;
584 mutex_lock(&ppp_mutex);
585 if (pf->kind == INTERFACE) {
586 ppp = PF_TO_PPP(pf);
587 if (file == ppp->owner)
588 ppp_shutdown_interface(ppp);
589 }
590 if (atomic_long_read(&file->f_count) <= 2) {
591 ppp_release(NULL, file);
592 err = 0;
593 } else
594 printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%ld\n",
595 atomic_long_read(&file->f_count));
596 mutex_unlock(&ppp_mutex);
597 return err;
598 }
599
600 if (pf->kind == CHANNEL) {
601 struct channel *pch;
602 struct ppp_channel *chan;
603
604 mutex_lock(&ppp_mutex);
605 pch = PF_TO_CHANNEL(pf);
606
607 switch (cmd) {
608 case PPPIOCCONNECT:
609 if (get_user(unit, p))
610 break;
611 err = ppp_connect_channel(pch, unit);
612 break;
613
614 case PPPIOCDISCONN:
615 err = ppp_disconnect_channel(pch);
616 break;
617
618 default:
619 down_read(&pch->chan_sem);
620 chan = pch->chan;
621 err = -ENOTTY;
622 if (chan && chan->ops->ioctl)
623 err = chan->ops->ioctl(chan, cmd, arg);
624 up_read(&pch->chan_sem);
625 }
626 mutex_unlock(&ppp_mutex);
627 return err;
628 }
629
630 if (pf->kind != INTERFACE) {
631 /* can't happen */
632 printk(KERN_ERR "PPP: not interface or channel??\n");
633 return -EINVAL;
634 }
635
636 mutex_lock(&ppp_mutex);
637 ppp = PF_TO_PPP(pf);
638 switch (cmd) {
639 case PPPIOCSMRU:
640 if (get_user(val, p))
641 break;
642 ppp->mru = val;
643 err = 0;
644 break;
645
646 case PPPIOCSFLAGS:
647 if (get_user(val, p))
648 break;
649 ppp_lock(ppp);
650 cflags = ppp->flags & ~val;
651 ppp->flags = val & SC_FLAG_BITS;
652 ppp_unlock(ppp);
653 if (cflags & SC_CCP_OPEN)
654 ppp_ccp_closed(ppp);
655 err = 0;
656 break;
657
658 case PPPIOCGFLAGS:
659 val = ppp->flags | ppp->xstate | ppp->rstate;
660 if (put_user(val, p))
661 break;
662 err = 0;
663 break;
664
665 case PPPIOCSCOMPRESS:
666 err = ppp_set_compress(ppp, arg);
667 break;
668
669 case PPPIOCGUNIT:
670 if (put_user(ppp->file.index, p))
671 break;
672 err = 0;
673 break;
674
675 case PPPIOCSDEBUG:
676 if (get_user(val, p))
677 break;
678 ppp->debug = val;
679 err = 0;
680 break;
681
682 case PPPIOCGDEBUG:
683 if (put_user(ppp->debug, p))
684 break;
685 err = 0;
686 break;
687
688 case PPPIOCGIDLE:
689 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
690 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
691 if (copy_to_user(argp, &idle, sizeof(idle)))
692 break;
693 err = 0;
694 break;
695
696 case PPPIOCSMAXCID:
697 if (get_user(val, p))
698 break;
699 val2 = 15;
700 if ((val >> 16) != 0) {
701 val2 = val >> 16;
702 val &= 0xffff;
703 }
704 vj = slhc_init(val2+1, val+1);
705 if (!vj) {
706 printk(KERN_ERR "PPP: no memory (VJ compressor)\n");
707 err = -ENOMEM;
708 break;
709 }
710 ppp_lock(ppp);
711 if (ppp->vj)
712 slhc_free(ppp->vj);
713 ppp->vj = vj;
714 ppp_unlock(ppp);
715 err = 0;
716 break;
717
718 case PPPIOCGNPMODE:
719 case PPPIOCSNPMODE:
720 if (copy_from_user(&npi, argp, sizeof(npi)))
721 break;
722 err = proto_to_npindex(npi.protocol);
723 if (err < 0)
724 break;
725 i = err;
726 if (cmd == PPPIOCGNPMODE) {
727 err = -EFAULT;
728 npi.mode = ppp->npmode[i];
729 if (copy_to_user(argp, &npi, sizeof(npi)))
730 break;
731 } else {
732 ppp->npmode[i] = npi.mode;
733 /* we may be able to transmit more packets now (??) */
734 netif_wake_queue(ppp->dev);
735 }
736 err = 0;
737 break;
738
739 #ifdef CONFIG_PPP_FILTER
740 case PPPIOCSPASS:
741 {
742 struct sock_filter *code;
743 err = get_filter(argp, &code);
744 if (err >= 0) {
745 ppp_lock(ppp);
746 kfree(ppp->pass_filter);
747 ppp->pass_filter = code;
748 ppp->pass_len = err;
749 ppp_unlock(ppp);
750 err = 0;
751 }
752 break;
753 }
754 case PPPIOCSACTIVE:
755 {
756 struct sock_filter *code;
757 err = get_filter(argp, &code);
758 if (err >= 0) {
759 ppp_lock(ppp);
760 kfree(ppp->active_filter);
761 ppp->active_filter = code;
762 ppp->active_len = err;
763 ppp_unlock(ppp);
764 err = 0;
765 }
766 break;
767 }
768 #endif /* CONFIG_PPP_FILTER */
769
770 #ifdef CONFIG_PPP_MULTILINK
771 case PPPIOCSMRRU:
772 if (get_user(val, p))
773 break;
774 ppp_recv_lock(ppp);
775 ppp->mrru = val;
776 ppp_recv_unlock(ppp);
777 err = 0;
778 break;
779 #endif /* CONFIG_PPP_MULTILINK */
780
781 default:
782 err = -ENOTTY;
783 }
784 mutex_unlock(&ppp_mutex);
785 return err;
786 }
787
788 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
789 struct file *file, unsigned int cmd, unsigned long arg)
790 {
791 int unit, err = -EFAULT;
792 struct ppp *ppp;
793 struct channel *chan;
794 struct ppp_net *pn;
795 int __user *p = (int __user *)arg;
796
797 mutex_lock(&ppp_mutex);
798 switch (cmd) {
799 case PPPIOCNEWUNIT:
800 /* Create a new ppp unit */
801 if (get_user(unit, p))
802 break;
803 ppp = ppp_create_interface(net, unit, &err);
804 if (!ppp)
805 break;
806 file->private_data = &ppp->file;
807 ppp->owner = file;
808 err = -EFAULT;
809 if (put_user(ppp->file.index, p))
810 break;
811 err = 0;
812 break;
813
814 case PPPIOCATTACH:
815 /* Attach to an existing ppp unit */
816 if (get_user(unit, p))
817 break;
818 err = -ENXIO;
819 pn = ppp_pernet(net);
820 mutex_lock(&pn->all_ppp_mutex);
821 ppp = ppp_find_unit(pn, unit);
822 if (ppp) {
823 atomic_inc(&ppp->file.refcnt);
824 file->private_data = &ppp->file;
825 err = 0;
826 }
827 mutex_unlock(&pn->all_ppp_mutex);
828 break;
829
830 case PPPIOCATTCHAN:
831 if (get_user(unit, p))
832 break;
833 err = -ENXIO;
834 pn = ppp_pernet(net);
835 spin_lock_bh(&pn->all_channels_lock);
836 chan = ppp_find_channel(pn, unit);
837 if (chan) {
838 atomic_inc(&chan->file.refcnt);
839 file->private_data = &chan->file;
840 err = 0;
841 }
842 spin_unlock_bh(&pn->all_channels_lock);
843 break;
844
845 default:
846 err = -ENOTTY;
847 }
848 mutex_unlock(&ppp_mutex);
849 return err;
850 }
851
852 static const struct file_operations ppp_device_fops = {
853 .owner = THIS_MODULE,
854 .read = ppp_read,
855 .write = ppp_write,
856 .poll = ppp_poll,
857 .unlocked_ioctl = ppp_ioctl,
858 .open = ppp_open,
859 .release = ppp_release,
860 .llseek = noop_llseek,
861 };
862
863 static __net_init int ppp_init_net(struct net *net)
864 {
865 struct ppp_net *pn = net_generic(net, ppp_net_id);
866
867 idr_init(&pn->units_idr);
868 mutex_init(&pn->all_ppp_mutex);
869
870 INIT_LIST_HEAD(&pn->all_channels);
871 INIT_LIST_HEAD(&pn->new_channels);
872
873 spin_lock_init(&pn->all_channels_lock);
874
875 return 0;
876 }
877
878 static __net_exit void ppp_exit_net(struct net *net)
879 {
880 struct ppp_net *pn = net_generic(net, ppp_net_id);
881
882 idr_destroy(&pn->units_idr);
883 }
884
885 static struct pernet_operations ppp_net_ops = {
886 .init = ppp_init_net,
887 .exit = ppp_exit_net,
888 .id = &ppp_net_id,
889 .size = sizeof(struct ppp_net),
890 };
891
892 #define PPP_MAJOR 108
893
894 /* Called at boot time if ppp is compiled into the kernel,
895 or at module load time (from init_module) if compiled as a module. */
896 static int __init ppp_init(void)
897 {
898 int err;
899
900 printk(KERN_INFO "PPP generic driver version " PPP_VERSION "\n");
901
902 err = register_pernet_device(&ppp_net_ops);
903 if (err) {
904 printk(KERN_ERR "failed to register PPP pernet device (%d)\n", err);
905 goto out;
906 }
907
908 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
909 if (err) {
910 printk(KERN_ERR "failed to register PPP device (%d)\n", err);
911 goto out_net;
912 }
913
914 ppp_class = class_create(THIS_MODULE, "ppp");
915 if (IS_ERR(ppp_class)) {
916 err = PTR_ERR(ppp_class);
917 goto out_chrdev;
918 }
919
920 /* not a big deal if we fail here :-) */
921 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
922
923 return 0;
924
925 out_chrdev:
926 unregister_chrdev(PPP_MAJOR, "ppp");
927 out_net:
928 unregister_pernet_device(&ppp_net_ops);
929 out:
930 return err;
931 }
932
933 /*
934 * Network interface unit routines.
935 */
936 static netdev_tx_t
937 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
938 {
939 struct ppp *ppp = netdev_priv(dev);
940 int npi, proto;
941 unsigned char *pp;
942
943 npi = ethertype_to_npindex(ntohs(skb->protocol));
944 if (npi < 0)
945 goto outf;
946
947 /* Drop, accept or reject the packet */
948 switch (ppp->npmode[npi]) {
949 case NPMODE_PASS:
950 break;
951 case NPMODE_QUEUE:
952 /* it would be nice to have a way to tell the network
953 system to queue this one up for later. */
954 goto outf;
955 case NPMODE_DROP:
956 case NPMODE_ERROR:
957 goto outf;
958 }
959
960 /* Put the 2-byte PPP protocol number on the front,
961 making sure there is room for the address and control fields. */
962 if (skb_cow_head(skb, PPP_HDRLEN))
963 goto outf;
964
965 pp = skb_push(skb, 2);
966 proto = npindex_to_proto[npi];
967 pp[0] = proto >> 8;
968 pp[1] = proto;
969
970 netif_stop_queue(dev);
971 skb_queue_tail(&ppp->file.xq, skb);
972 ppp_xmit_process(ppp);
973 return NETDEV_TX_OK;
974
975 outf:
976 kfree_skb(skb);
977 ++dev->stats.tx_dropped;
978 return NETDEV_TX_OK;
979 }
980
981 static int
982 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
983 {
984 struct ppp *ppp = netdev_priv(dev);
985 int err = -EFAULT;
986 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
987 struct ppp_stats stats;
988 struct ppp_comp_stats cstats;
989 char *vers;
990
991 switch (cmd) {
992 case SIOCGPPPSTATS:
993 ppp_get_stats(ppp, &stats);
994 if (copy_to_user(addr, &stats, sizeof(stats)))
995 break;
996 err = 0;
997 break;
998
999 case SIOCGPPPCSTATS:
1000 memset(&cstats, 0, sizeof(cstats));
1001 if (ppp->xc_state)
1002 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
1003 if (ppp->rc_state)
1004 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
1005 if (copy_to_user(addr, &cstats, sizeof(cstats)))
1006 break;
1007 err = 0;
1008 break;
1009
1010 case SIOCGPPPVER:
1011 vers = PPP_VERSION;
1012 if (copy_to_user(addr, vers, strlen(vers) + 1))
1013 break;
1014 err = 0;
1015 break;
1016
1017 default:
1018 err = -EINVAL;
1019 }
1020
1021 return err;
1022 }
1023
1024 static const struct net_device_ops ppp_netdev_ops = {
1025 .ndo_start_xmit = ppp_start_xmit,
1026 .ndo_do_ioctl = ppp_net_ioctl,
1027 };
1028
1029 static void ppp_setup(struct net_device *dev)
1030 {
1031 dev->netdev_ops = &ppp_netdev_ops;
1032 dev->hard_header_len = PPP_HDRLEN;
1033 dev->mtu = PPP_MTU;
1034 dev->addr_len = 0;
1035 dev->tx_queue_len = 3;
1036 dev->type = ARPHRD_PPP;
1037 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1038 dev->features |= NETIF_F_NETNS_LOCAL;
1039 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1040 }
1041
1042 /*
1043 * Transmit-side routines.
1044 */
1045
1046 /*
1047 * Called to do any work queued up on the transmit side
1048 * that can now be done.
1049 */
1050 static void
1051 ppp_xmit_process(struct ppp *ppp)
1052 {
1053 struct sk_buff *skb;
1054
1055 ppp_xmit_lock(ppp);
1056 if (!ppp->closing) {
1057 ppp_push(ppp);
1058 while (!ppp->xmit_pending &&
1059 (skb = skb_dequeue(&ppp->file.xq)))
1060 ppp_send_frame(ppp, skb);
1061 /* If there's no work left to do, tell the core net
1062 code that we can accept some more. */
1063 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1064 netif_wake_queue(ppp->dev);
1065 }
1066 ppp_xmit_unlock(ppp);
1067 }
1068
1069 static inline struct sk_buff *
1070 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1071 {
1072 struct sk_buff *new_skb;
1073 int len;
1074 int new_skb_size = ppp->dev->mtu +
1075 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1076 int compressor_skb_size = ppp->dev->mtu +
1077 ppp->xcomp->comp_extra + PPP_HDRLEN;
1078 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1079 if (!new_skb) {
1080 if (net_ratelimit())
1081 printk(KERN_ERR "PPP: no memory (comp pkt)\n");
1082 return NULL;
1083 }
1084 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1085 skb_reserve(new_skb,
1086 ppp->dev->hard_header_len - PPP_HDRLEN);
1087
1088 /* compressor still expects A/C bytes in hdr */
1089 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1090 new_skb->data, skb->len + 2,
1091 compressor_skb_size);
1092 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1093 kfree_skb(skb);
1094 skb = new_skb;
1095 skb_put(skb, len);
1096 skb_pull(skb, 2); /* pull off A/C bytes */
1097 } else if (len == 0) {
1098 /* didn't compress, or CCP not up yet */
1099 kfree_skb(new_skb);
1100 new_skb = skb;
1101 } else {
1102 /*
1103 * (len < 0)
1104 * MPPE requires that we do not send unencrypted
1105 * frames. The compressor will return -1 if we
1106 * should drop the frame. We cannot simply test
1107 * the compress_proto because MPPE and MPPC share
1108 * the same number.
1109 */
1110 if (net_ratelimit())
1111 printk(KERN_ERR "ppp: compressor dropped pkt\n");
1112 kfree_skb(skb);
1113 kfree_skb(new_skb);
1114 new_skb = NULL;
1115 }
1116 return new_skb;
1117 }
1118
1119 /*
1120 * Compress and send a frame.
1121 * The caller should have locked the xmit path,
1122 * and xmit_pending should be 0.
1123 */
1124 static void
1125 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1126 {
1127 int proto = PPP_PROTO(skb);
1128 struct sk_buff *new_skb;
1129 int len;
1130 unsigned char *cp;
1131
1132 if (proto < 0x8000) {
1133 #ifdef CONFIG_PPP_FILTER
1134 /* check if we should pass this packet */
1135 /* the filter instructions are constructed assuming
1136 a four-byte PPP header on each packet */
1137 *skb_push(skb, 2) = 1;
1138 if (ppp->pass_filter &&
1139 sk_run_filter(skb, ppp->pass_filter,
1140 ppp->pass_len) == 0) {
1141 if (ppp->debug & 1)
1142 printk(KERN_DEBUG "PPP: outbound frame not passed\n");
1143 kfree_skb(skb);
1144 return;
1145 }
1146 /* if this packet passes the active filter, record the time */
1147 if (!(ppp->active_filter &&
1148 sk_run_filter(skb, ppp->active_filter,
1149 ppp->active_len) == 0))
1150 ppp->last_xmit = jiffies;
1151 skb_pull(skb, 2);
1152 #else
1153 /* for data packets, record the time */
1154 ppp->last_xmit = jiffies;
1155 #endif /* CONFIG_PPP_FILTER */
1156 }
1157
1158 ++ppp->dev->stats.tx_packets;
1159 ppp->dev->stats.tx_bytes += skb->len - 2;
1160
1161 switch (proto) {
1162 case PPP_IP:
1163 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1164 break;
1165 /* try to do VJ TCP header compression */
1166 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1167 GFP_ATOMIC);
1168 if (!new_skb) {
1169 printk(KERN_ERR "PPP: no memory (VJ comp pkt)\n");
1170 goto drop;
1171 }
1172 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1173 cp = skb->data + 2;
1174 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1175 new_skb->data + 2, &cp,
1176 !(ppp->flags & SC_NO_TCP_CCID));
1177 if (cp == skb->data + 2) {
1178 /* didn't compress */
1179 kfree_skb(new_skb);
1180 } else {
1181 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1182 proto = PPP_VJC_COMP;
1183 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1184 } else {
1185 proto = PPP_VJC_UNCOMP;
1186 cp[0] = skb->data[2];
1187 }
1188 kfree_skb(skb);
1189 skb = new_skb;
1190 cp = skb_put(skb, len + 2);
1191 cp[0] = 0;
1192 cp[1] = proto;
1193 }
1194 break;
1195
1196 case PPP_CCP:
1197 /* peek at outbound CCP frames */
1198 ppp_ccp_peek(ppp, skb, 0);
1199 break;
1200 }
1201
1202 /* try to do packet compression */
1203 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state &&
1204 proto != PPP_LCP && proto != PPP_CCP) {
1205 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1206 if (net_ratelimit())
1207 printk(KERN_ERR "ppp: compression required but down - pkt dropped.\n");
1208 goto drop;
1209 }
1210 skb = pad_compress_skb(ppp, skb);
1211 if (!skb)
1212 goto drop;
1213 }
1214
1215 /*
1216 * If we are waiting for traffic (demand dialling),
1217 * queue it up for pppd to receive.
1218 */
1219 if (ppp->flags & SC_LOOP_TRAFFIC) {
1220 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1221 goto drop;
1222 skb_queue_tail(&ppp->file.rq, skb);
1223 wake_up_interruptible(&ppp->file.rwait);
1224 return;
1225 }
1226
1227 ppp->xmit_pending = skb;
1228 ppp_push(ppp);
1229 return;
1230
1231 drop:
1232 kfree_skb(skb);
1233 ++ppp->dev->stats.tx_errors;
1234 }
1235
1236 /*
1237 * Try to send the frame in xmit_pending.
1238 * The caller should have the xmit path locked.
1239 */
1240 static void
1241 ppp_push(struct ppp *ppp)
1242 {
1243 struct list_head *list;
1244 struct channel *pch;
1245 struct sk_buff *skb = ppp->xmit_pending;
1246
1247 if (!skb)
1248 return;
1249
1250 list = &ppp->channels;
1251 if (list_empty(list)) {
1252 /* nowhere to send the packet, just drop it */
1253 ppp->xmit_pending = NULL;
1254 kfree_skb(skb);
1255 return;
1256 }
1257
1258 if ((ppp->flags & SC_MULTILINK) == 0) {
1259 /* not doing multilink: send it down the first channel */
1260 list = list->next;
1261 pch = list_entry(list, struct channel, clist);
1262
1263 spin_lock_bh(&pch->downl);
1264 if (pch->chan) {
1265 if (pch->chan->ops->start_xmit(pch->chan, skb))
1266 ppp->xmit_pending = NULL;
1267 } else {
1268 /* channel got unregistered */
1269 kfree_skb(skb);
1270 ppp->xmit_pending = NULL;
1271 }
1272 spin_unlock_bh(&pch->downl);
1273 return;
1274 }
1275
1276 #ifdef CONFIG_PPP_MULTILINK
1277 /* Multilink: fragment the packet over as many links
1278 as can take the packet at the moment. */
1279 if (!ppp_mp_explode(ppp, skb))
1280 return;
1281 #endif /* CONFIG_PPP_MULTILINK */
1282
1283 ppp->xmit_pending = NULL;
1284 kfree_skb(skb);
1285 }
1286
1287 #ifdef CONFIG_PPP_MULTILINK
1288 static bool mp_protocol_compress __read_mostly = true;
1289 module_param(mp_protocol_compress, bool, S_IRUGO | S_IWUSR);
1290 MODULE_PARM_DESC(mp_protocol_compress,
1291 "compress protocol id in multilink fragments");
1292
1293 /*
1294 * Divide a packet to be transmitted into fragments and
1295 * send them out the individual links.
1296 */
1297 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1298 {
1299 int len, totlen;
1300 int i, bits, hdrlen, mtu;
1301 int flen;
1302 int navail, nfree, nzero;
1303 int nbigger;
1304 int totspeed;
1305 int totfree;
1306 unsigned char *p, *q;
1307 struct list_head *list;
1308 struct channel *pch;
1309 struct sk_buff *frag;
1310 struct ppp_channel *chan;
1311
1312 totspeed = 0; /*total bitrate of the bundle*/
1313 nfree = 0; /* # channels which have no packet already queued */
1314 navail = 0; /* total # of usable channels (not deregistered) */
1315 nzero = 0; /* number of channels with zero speed associated*/
1316 totfree = 0; /*total # of channels available and
1317 *having no queued packets before
1318 *starting the fragmentation*/
1319
1320 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1321 i = 0;
1322 list_for_each_entry(pch, &ppp->channels, clist) {
1323 if (pch->chan) {
1324 pch->avail = 1;
1325 navail++;
1326 pch->speed = pch->chan->speed;
1327 } else {
1328 pch->avail = 0;
1329 }
1330 if (pch->avail) {
1331 if (skb_queue_empty(&pch->file.xq) ||
1332 !pch->had_frag) {
1333 if (pch->speed == 0)
1334 nzero++;
1335 else
1336 totspeed += pch->speed;
1337
1338 pch->avail = 2;
1339 ++nfree;
1340 ++totfree;
1341 }
1342 if (!pch->had_frag && i < ppp->nxchan)
1343 ppp->nxchan = i;
1344 }
1345 ++i;
1346 }
1347 /*
1348 * Don't start sending this packet unless at least half of
1349 * the channels are free. This gives much better TCP
1350 * performance if we have a lot of channels.
1351 */
1352 if (nfree == 0 || nfree < navail / 2)
1353 return 0; /* can't take now, leave it in xmit_pending */
1354
1355 /* Do protocol field compression */
1356 p = skb->data;
1357 len = skb->len;
1358 if (*p == 0 && mp_protocol_compress) {
1359 ++p;
1360 --len;
1361 }
1362
1363 totlen = len;
1364 nbigger = len % nfree;
1365
1366 /* skip to the channel after the one we last used
1367 and start at that one */
1368 list = &ppp->channels;
1369 for (i = 0; i < ppp->nxchan; ++i) {
1370 list = list->next;
1371 if (list == &ppp->channels) {
1372 i = 0;
1373 break;
1374 }
1375 }
1376
1377 /* create a fragment for each channel */
1378 bits = B;
1379 while (len > 0) {
1380 list = list->next;
1381 if (list == &ppp->channels) {
1382 i = 0;
1383 continue;
1384 }
1385 pch = list_entry(list, struct channel, clist);
1386 ++i;
1387 if (!pch->avail)
1388 continue;
1389
1390 /*
1391 * Skip this channel if it has a fragment pending already and
1392 * we haven't given a fragment to all of the free channels.
1393 */
1394 if (pch->avail == 1) {
1395 if (nfree > 0)
1396 continue;
1397 } else {
1398 pch->avail = 1;
1399 }
1400
1401 /* check the channel's mtu and whether it is still attached. */
1402 spin_lock_bh(&pch->downl);
1403 if (pch->chan == NULL) {
1404 /* can't use this channel, it's being deregistered */
1405 if (pch->speed == 0)
1406 nzero--;
1407 else
1408 totspeed -= pch->speed;
1409
1410 spin_unlock_bh(&pch->downl);
1411 pch->avail = 0;
1412 totlen = len;
1413 totfree--;
1414 nfree--;
1415 if (--navail == 0)
1416 break;
1417 continue;
1418 }
1419
1420 /*
1421 *if the channel speed is not set divide
1422 *the packet evenly among the free channels;
1423 *otherwise divide it according to the speed
1424 *of the channel we are going to transmit on
1425 */
1426 flen = len;
1427 if (nfree > 0) {
1428 if (pch->speed == 0) {
1429 flen = len/nfree;
1430 if (nbigger > 0) {
1431 flen++;
1432 nbigger--;
1433 }
1434 } else {
1435 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
1436 ((totspeed*totfree)/pch->speed)) - hdrlen;
1437 if (nbigger > 0) {
1438 flen += ((totfree - nzero)*pch->speed)/totspeed;
1439 nbigger -= ((totfree - nzero)*pch->speed)/
1440 totspeed;
1441 }
1442 }
1443 nfree--;
1444 }
1445
1446 /*
1447 *check if we are on the last channel or
1448 *we exceded the lenght of the data to
1449 *fragment
1450 */
1451 if ((nfree <= 0) || (flen > len))
1452 flen = len;
1453 /*
1454 *it is not worth to tx on slow channels:
1455 *in that case from the resulting flen according to the
1456 *above formula will be equal or less than zero.
1457 *Skip the channel in this case
1458 */
1459 if (flen <= 0) {
1460 pch->avail = 2;
1461 spin_unlock_bh(&pch->downl);
1462 continue;
1463 }
1464
1465 mtu = pch->chan->mtu - hdrlen;
1466 if (mtu < 4)
1467 mtu = 4;
1468 if (flen > mtu)
1469 flen = mtu;
1470 if (flen == len)
1471 bits |= E;
1472 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1473 if (!frag)
1474 goto noskb;
1475 q = skb_put(frag, flen + hdrlen);
1476
1477 /* make the MP header */
1478 q[0] = PPP_MP >> 8;
1479 q[1] = PPP_MP;
1480 if (ppp->flags & SC_MP_XSHORTSEQ) {
1481 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1482 q[3] = ppp->nxseq;
1483 } else {
1484 q[2] = bits;
1485 q[3] = ppp->nxseq >> 16;
1486 q[4] = ppp->nxseq >> 8;
1487 q[5] = ppp->nxseq;
1488 }
1489
1490 memcpy(q + hdrlen, p, flen);
1491
1492 /* try to send it down the channel */
1493 chan = pch->chan;
1494 if (!skb_queue_empty(&pch->file.xq) ||
1495 !chan->ops->start_xmit(chan, frag))
1496 skb_queue_tail(&pch->file.xq, frag);
1497 pch->had_frag = 1;
1498 p += flen;
1499 len -= flen;
1500 ++ppp->nxseq;
1501 bits = 0;
1502 spin_unlock_bh(&pch->downl);
1503 }
1504 ppp->nxchan = i;
1505
1506 return 1;
1507
1508 noskb:
1509 spin_unlock_bh(&pch->downl);
1510 if (ppp->debug & 1)
1511 printk(KERN_ERR "PPP: no memory (fragment)\n");
1512 ++ppp->dev->stats.tx_errors;
1513 ++ppp->nxseq;
1514 return 1; /* abandon the frame */
1515 }
1516 #endif /* CONFIG_PPP_MULTILINK */
1517
1518 /*
1519 * Try to send data out on a channel.
1520 */
1521 static void
1522 ppp_channel_push(struct channel *pch)
1523 {
1524 struct sk_buff *skb;
1525 struct ppp *ppp;
1526
1527 spin_lock_bh(&pch->downl);
1528 if (pch->chan) {
1529 while (!skb_queue_empty(&pch->file.xq)) {
1530 skb = skb_dequeue(&pch->file.xq);
1531 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1532 /* put the packet back and try again later */
1533 skb_queue_head(&pch->file.xq, skb);
1534 break;
1535 }
1536 }
1537 } else {
1538 /* channel got deregistered */
1539 skb_queue_purge(&pch->file.xq);
1540 }
1541 spin_unlock_bh(&pch->downl);
1542 /* see if there is anything from the attached unit to be sent */
1543 if (skb_queue_empty(&pch->file.xq)) {
1544 read_lock_bh(&pch->upl);
1545 ppp = pch->ppp;
1546 if (ppp)
1547 ppp_xmit_process(ppp);
1548 read_unlock_bh(&pch->upl);
1549 }
1550 }
1551
1552 /*
1553 * Receive-side routines.
1554 */
1555
1556 struct ppp_mp_skb_parm {
1557 u32 sequence;
1558 u8 BEbits;
1559 };
1560 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb))
1561
1562 static inline void
1563 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1564 {
1565 ppp_recv_lock(ppp);
1566 if (!ppp->closing)
1567 ppp_receive_frame(ppp, skb, pch);
1568 else
1569 kfree_skb(skb);
1570 ppp_recv_unlock(ppp);
1571 }
1572
1573 void
1574 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1575 {
1576 struct channel *pch = chan->ppp;
1577 int proto;
1578
1579 if (!pch) {
1580 kfree_skb(skb);
1581 return;
1582 }
1583
1584 read_lock_bh(&pch->upl);
1585 if (!pskb_may_pull(skb, 2)) {
1586 kfree_skb(skb);
1587 if (pch->ppp) {
1588 ++pch->ppp->dev->stats.rx_length_errors;
1589 ppp_receive_error(pch->ppp);
1590 }
1591 goto done;
1592 }
1593
1594 proto = PPP_PROTO(skb);
1595 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1596 /* put it on the channel queue */
1597 skb_queue_tail(&pch->file.rq, skb);
1598 /* drop old frames if queue too long */
1599 while (pch->file.rq.qlen > PPP_MAX_RQLEN &&
1600 (skb = skb_dequeue(&pch->file.rq)))
1601 kfree_skb(skb);
1602 wake_up_interruptible(&pch->file.rwait);
1603 } else {
1604 ppp_do_recv(pch->ppp, skb, pch);
1605 }
1606
1607 done:
1608 read_unlock_bh(&pch->upl);
1609 }
1610
1611 /* Put a 0-length skb in the receive queue as an error indication */
1612 void
1613 ppp_input_error(struct ppp_channel *chan, int code)
1614 {
1615 struct channel *pch = chan->ppp;
1616 struct sk_buff *skb;
1617
1618 if (!pch)
1619 return;
1620
1621 read_lock_bh(&pch->upl);
1622 if (pch->ppp) {
1623 skb = alloc_skb(0, GFP_ATOMIC);
1624 if (skb) {
1625 skb->len = 0; /* probably unnecessary */
1626 skb->cb[0] = code;
1627 ppp_do_recv(pch->ppp, skb, pch);
1628 }
1629 }
1630 read_unlock_bh(&pch->upl);
1631 }
1632
1633 /*
1634 * We come in here to process a received frame.
1635 * The receive side of the ppp unit is locked.
1636 */
1637 static void
1638 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1639 {
1640 /* note: a 0-length skb is used as an error indication */
1641 if (skb->len > 0) {
1642 #ifdef CONFIG_PPP_MULTILINK
1643 /* XXX do channel-level decompression here */
1644 if (PPP_PROTO(skb) == PPP_MP)
1645 ppp_receive_mp_frame(ppp, skb, pch);
1646 else
1647 #endif /* CONFIG_PPP_MULTILINK */
1648 ppp_receive_nonmp_frame(ppp, skb);
1649 } else {
1650 kfree_skb(skb);
1651 ppp_receive_error(ppp);
1652 }
1653 }
1654
1655 static void
1656 ppp_receive_error(struct ppp *ppp)
1657 {
1658 ++ppp->dev->stats.rx_errors;
1659 if (ppp->vj)
1660 slhc_toss(ppp->vj);
1661 }
1662
1663 static void
1664 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1665 {
1666 struct sk_buff *ns;
1667 int proto, len, npi;
1668
1669 /*
1670 * Decompress the frame, if compressed.
1671 * Note that some decompressors need to see uncompressed frames
1672 * that come in as well as compressed frames.
1673 */
1674 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) &&
1675 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1676 skb = ppp_decompress_frame(ppp, skb);
1677
1678 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1679 goto err;
1680
1681 proto = PPP_PROTO(skb);
1682 switch (proto) {
1683 case PPP_VJC_COMP:
1684 /* decompress VJ compressed packets */
1685 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1686 goto err;
1687
1688 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1689 /* copy to a new sk_buff with more tailroom */
1690 ns = dev_alloc_skb(skb->len + 128);
1691 if (!ns) {
1692 printk(KERN_ERR"PPP: no memory (VJ decomp)\n");
1693 goto err;
1694 }
1695 skb_reserve(ns, 2);
1696 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1697 kfree_skb(skb);
1698 skb = ns;
1699 }
1700 else
1701 skb->ip_summed = CHECKSUM_NONE;
1702
1703 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1704 if (len <= 0) {
1705 printk(KERN_DEBUG "PPP: VJ decompression error\n");
1706 goto err;
1707 }
1708 len += 2;
1709 if (len > skb->len)
1710 skb_put(skb, len - skb->len);
1711 else if (len < skb->len)
1712 skb_trim(skb, len);
1713 proto = PPP_IP;
1714 break;
1715
1716 case PPP_VJC_UNCOMP:
1717 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1718 goto err;
1719
1720 /* Until we fix the decompressor need to make sure
1721 * data portion is linear.
1722 */
1723 if (!pskb_may_pull(skb, skb->len))
1724 goto err;
1725
1726 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1727 printk(KERN_ERR "PPP: VJ uncompressed error\n");
1728 goto err;
1729 }
1730 proto = PPP_IP;
1731 break;
1732
1733 case PPP_CCP:
1734 ppp_ccp_peek(ppp, skb, 1);
1735 break;
1736 }
1737
1738 ++ppp->dev->stats.rx_packets;
1739 ppp->dev->stats.rx_bytes += skb->len - 2;
1740
1741 npi = proto_to_npindex(proto);
1742 if (npi < 0) {
1743 /* control or unknown frame - pass it to pppd */
1744 skb_queue_tail(&ppp->file.rq, skb);
1745 /* limit queue length by dropping old frames */
1746 while (ppp->file.rq.qlen > PPP_MAX_RQLEN &&
1747 (skb = skb_dequeue(&ppp->file.rq)))
1748 kfree_skb(skb);
1749 /* wake up any process polling or blocking on read */
1750 wake_up_interruptible(&ppp->file.rwait);
1751
1752 } else {
1753 /* network protocol frame - give it to the kernel */
1754
1755 #ifdef CONFIG_PPP_FILTER
1756 /* check if the packet passes the pass and active filters */
1757 /* the filter instructions are constructed assuming
1758 a four-byte PPP header on each packet */
1759 if (ppp->pass_filter || ppp->active_filter) {
1760 if (skb_cloned(skb) &&
1761 pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
1762 goto err;
1763
1764 *skb_push(skb, 2) = 0;
1765 if (ppp->pass_filter &&
1766 sk_run_filter(skb, ppp->pass_filter,
1767 ppp->pass_len) == 0) {
1768 if (ppp->debug & 1)
1769 printk(KERN_DEBUG "PPP: inbound frame "
1770 "not passed\n");
1771 kfree_skb(skb);
1772 return;
1773 }
1774 if (!(ppp->active_filter &&
1775 sk_run_filter(skb, ppp->active_filter,
1776 ppp->active_len) == 0))
1777 ppp->last_recv = jiffies;
1778 __skb_pull(skb, 2);
1779 } else
1780 #endif /* CONFIG_PPP_FILTER */
1781 ppp->last_recv = jiffies;
1782
1783 if ((ppp->dev->flags & IFF_UP) == 0 ||
1784 ppp->npmode[npi] != NPMODE_PASS) {
1785 kfree_skb(skb);
1786 } else {
1787 /* chop off protocol */
1788 skb_pull_rcsum(skb, 2);
1789 skb->dev = ppp->dev;
1790 skb->protocol = htons(npindex_to_ethertype[npi]);
1791 skb_reset_mac_header(skb);
1792 netif_rx(skb);
1793 }
1794 }
1795 return;
1796
1797 err:
1798 kfree_skb(skb);
1799 ppp_receive_error(ppp);
1800 }
1801
1802 static struct sk_buff *
1803 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1804 {
1805 int proto = PPP_PROTO(skb);
1806 struct sk_buff *ns;
1807 int len;
1808
1809 /* Until we fix all the decompressor's need to make sure
1810 * data portion is linear.
1811 */
1812 if (!pskb_may_pull(skb, skb->len))
1813 goto err;
1814
1815 if (proto == PPP_COMP) {
1816 int obuff_size;
1817
1818 switch(ppp->rcomp->compress_proto) {
1819 case CI_MPPE:
1820 obuff_size = ppp->mru + PPP_HDRLEN + 1;
1821 break;
1822 default:
1823 obuff_size = ppp->mru + PPP_HDRLEN;
1824 break;
1825 }
1826
1827 ns = dev_alloc_skb(obuff_size);
1828 if (!ns) {
1829 printk(KERN_ERR "ppp_decompress_frame: no memory\n");
1830 goto err;
1831 }
1832 /* the decompressor still expects the A/C bytes in the hdr */
1833 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1834 skb->len + 2, ns->data, obuff_size);
1835 if (len < 0) {
1836 /* Pass the compressed frame to pppd as an
1837 error indication. */
1838 if (len == DECOMP_FATALERROR)
1839 ppp->rstate |= SC_DC_FERROR;
1840 kfree_skb(ns);
1841 goto err;
1842 }
1843
1844 kfree_skb(skb);
1845 skb = ns;
1846 skb_put(skb, len);
1847 skb_pull(skb, 2); /* pull off the A/C bytes */
1848
1849 } else {
1850 /* Uncompressed frame - pass to decompressor so it
1851 can update its dictionary if necessary. */
1852 if (ppp->rcomp->incomp)
1853 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1854 skb->len + 2);
1855 }
1856
1857 return skb;
1858
1859 err:
1860 ppp->rstate |= SC_DC_ERROR;
1861 ppp_receive_error(ppp);
1862 return skb;
1863 }
1864
1865 #ifdef CONFIG_PPP_MULTILINK
1866 /*
1867 * Receive a multilink frame.
1868 * We put it on the reconstruction queue and then pull off
1869 * as many completed frames as we can.
1870 */
1871 static void
1872 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1873 {
1874 u32 mask, seq;
1875 struct channel *ch;
1876 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1877
1878 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
1879 goto err; /* no good, throw it away */
1880
1881 /* Decode sequence number and begin/end bits */
1882 if (ppp->flags & SC_MP_SHORTSEQ) {
1883 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1884 mask = 0xfff;
1885 } else {
1886 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1887 mask = 0xffffff;
1888 }
1889 PPP_MP_CB(skb)->BEbits = skb->data[2];
1890 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
1891
1892 /*
1893 * Do protocol ID decompression on the first fragment of each packet.
1894 */
1895 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1))
1896 *skb_push(skb, 1) = 0;
1897
1898 /*
1899 * Expand sequence number to 32 bits, making it as close
1900 * as possible to ppp->minseq.
1901 */
1902 seq |= ppp->minseq & ~mask;
1903 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
1904 seq += mask + 1;
1905 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
1906 seq -= mask + 1; /* should never happen */
1907 PPP_MP_CB(skb)->sequence = seq;
1908 pch->lastseq = seq;
1909
1910 /*
1911 * If this packet comes before the next one we were expecting,
1912 * drop it.
1913 */
1914 if (seq_before(seq, ppp->nextseq)) {
1915 kfree_skb(skb);
1916 ++ppp->dev->stats.rx_dropped;
1917 ppp_receive_error(ppp);
1918 return;
1919 }
1920
1921 /*
1922 * Reevaluate minseq, the minimum over all channels of the
1923 * last sequence number received on each channel. Because of
1924 * the increasing sequence number rule, we know that any fragment
1925 * before `minseq' which hasn't arrived is never going to arrive.
1926 * The list of channels can't change because we have the receive
1927 * side of the ppp unit locked.
1928 */
1929 list_for_each_entry(ch, &ppp->channels, clist) {
1930 if (seq_before(ch->lastseq, seq))
1931 seq = ch->lastseq;
1932 }
1933 if (seq_before(ppp->minseq, seq))
1934 ppp->minseq = seq;
1935
1936 /* Put the fragment on the reconstruction queue */
1937 ppp_mp_insert(ppp, skb);
1938
1939 /* If the queue is getting long, don't wait any longer for packets
1940 before the start of the queue. */
1941 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
1942 struct sk_buff *mskb = skb_peek(&ppp->mrq);
1943 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence))
1944 ppp->minseq = PPP_MP_CB(mskb)->sequence;
1945 }
1946
1947 /* Pull completed packets off the queue and receive them. */
1948 while ((skb = ppp_mp_reconstruct(ppp))) {
1949 if (pskb_may_pull(skb, 2))
1950 ppp_receive_nonmp_frame(ppp, skb);
1951 else {
1952 ++ppp->dev->stats.rx_length_errors;
1953 kfree_skb(skb);
1954 ppp_receive_error(ppp);
1955 }
1956 }
1957
1958 return;
1959
1960 err:
1961 kfree_skb(skb);
1962 ppp_receive_error(ppp);
1963 }
1964
1965 /*
1966 * Insert a fragment on the MP reconstruction queue.
1967 * The queue is ordered by increasing sequence number.
1968 */
1969 static void
1970 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
1971 {
1972 struct sk_buff *p;
1973 struct sk_buff_head *list = &ppp->mrq;
1974 u32 seq = PPP_MP_CB(skb)->sequence;
1975
1976 /* N.B. we don't need to lock the list lock because we have the
1977 ppp unit receive-side lock. */
1978 skb_queue_walk(list, p) {
1979 if (seq_before(seq, PPP_MP_CB(p)->sequence))
1980 break;
1981 }
1982 __skb_queue_before(list, p, skb);
1983 }
1984
1985 /*
1986 * Reconstruct a packet from the MP fragment queue.
1987 * We go through increasing sequence numbers until we find a
1988 * complete packet, or we get to the sequence number for a fragment
1989 * which hasn't arrived but might still do so.
1990 */
1991 static struct sk_buff *
1992 ppp_mp_reconstruct(struct ppp *ppp)
1993 {
1994 u32 seq = ppp->nextseq;
1995 u32 minseq = ppp->minseq;
1996 struct sk_buff_head *list = &ppp->mrq;
1997 struct sk_buff *p, *next;
1998 struct sk_buff *head, *tail;
1999 struct sk_buff *skb = NULL;
2000 int lost = 0, len = 0;
2001
2002 if (ppp->mrru == 0) /* do nothing until mrru is set */
2003 return NULL;
2004 head = list->next;
2005 tail = NULL;
2006 for (p = head; p != (struct sk_buff *) list; p = next) {
2007 next = p->next;
2008 if (seq_before(PPP_MP_CB(p)->sequence, seq)) {
2009 /* this can't happen, anyway ignore the skb */
2010 printk(KERN_ERR "ppp_mp_reconstruct bad seq %u < %u\n",
2011 PPP_MP_CB(p)->sequence, seq);
2012 head = next;
2013 continue;
2014 }
2015 if (PPP_MP_CB(p)->sequence != seq) {
2016 /* Fragment `seq' is missing. If it is after
2017 minseq, it might arrive later, so stop here. */
2018 if (seq_after(seq, minseq))
2019 break;
2020 /* Fragment `seq' is lost, keep going. */
2021 lost = 1;
2022 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)?
2023 minseq + 1: PPP_MP_CB(p)->sequence;
2024 next = p;
2025 continue;
2026 }
2027
2028 /*
2029 * At this point we know that all the fragments from
2030 * ppp->nextseq to seq are either present or lost.
2031 * Also, there are no complete packets in the queue
2032 * that have no missing fragments and end before this
2033 * fragment.
2034 */
2035
2036 /* B bit set indicates this fragment starts a packet */
2037 if (PPP_MP_CB(p)->BEbits & B) {
2038 head = p;
2039 lost = 0;
2040 len = 0;
2041 }
2042
2043 len += p->len;
2044
2045 /* Got a complete packet yet? */
2046 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) &&
2047 (PPP_MP_CB(head)->BEbits & B)) {
2048 if (len > ppp->mrru + 2) {
2049 ++ppp->dev->stats.rx_length_errors;
2050 printk(KERN_DEBUG "PPP: reconstructed packet"
2051 " is too long (%d)\n", len);
2052 } else if (p == head) {
2053 /* fragment is complete packet - reuse skb */
2054 tail = p;
2055 skb = skb_get(p);
2056 break;
2057 } else if ((skb = dev_alloc_skb(len)) == NULL) {
2058 ++ppp->dev->stats.rx_missed_errors;
2059 printk(KERN_DEBUG "PPP: no memory for "
2060 "reconstructed packet");
2061 } else {
2062 tail = p;
2063 break;
2064 }
2065 ppp->nextseq = seq + 1;
2066 }
2067
2068 /*
2069 * If this is the ending fragment of a packet,
2070 * and we haven't found a complete valid packet yet,
2071 * we can discard up to and including this fragment.
2072 */
2073 if (PPP_MP_CB(p)->BEbits & E)
2074 head = next;
2075
2076 ++seq;
2077 }
2078
2079 /* If we have a complete packet, copy it all into one skb. */
2080 if (tail != NULL) {
2081 /* If we have discarded any fragments,
2082 signal a receive error. */
2083 if (PPP_MP_CB(head)->sequence != ppp->nextseq) {
2084 if (ppp->debug & 1)
2085 printk(KERN_DEBUG " missed pkts %u..%u\n",
2086 ppp->nextseq,
2087 PPP_MP_CB(head)->sequence-1);
2088 ++ppp->dev->stats.rx_dropped;
2089 ppp_receive_error(ppp);
2090 }
2091
2092 if (head != tail)
2093 /* copy to a single skb */
2094 for (p = head; p != tail->next; p = p->next)
2095 skb_copy_bits(p, 0, skb_put(skb, p->len), p->len);
2096 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1;
2097 head = tail->next;
2098 }
2099
2100 /* Discard all the skbuffs that we have copied the data out of
2101 or that we can't use. */
2102 while ((p = list->next) != head) {
2103 __skb_unlink(p, list);
2104 kfree_skb(p);
2105 }
2106
2107 return skb;
2108 }
2109 #endif /* CONFIG_PPP_MULTILINK */
2110
2111 /*
2112 * Channel interface.
2113 */
2114
2115 /* Create a new, unattached ppp channel. */
2116 int ppp_register_channel(struct ppp_channel *chan)
2117 {
2118 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2119 }
2120
2121 /* Create a new, unattached ppp channel for specified net. */
2122 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
2123 {
2124 struct channel *pch;
2125 struct ppp_net *pn;
2126
2127 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2128 if (!pch)
2129 return -ENOMEM;
2130
2131 pn = ppp_pernet(net);
2132
2133 pch->ppp = NULL;
2134 pch->chan = chan;
2135 pch->chan_net = net;
2136 chan->ppp = pch;
2137 init_ppp_file(&pch->file, CHANNEL);
2138 pch->file.hdrlen = chan->hdrlen;
2139 #ifdef CONFIG_PPP_MULTILINK
2140 pch->lastseq = -1;
2141 #endif /* CONFIG_PPP_MULTILINK */
2142 init_rwsem(&pch->chan_sem);
2143 spin_lock_init(&pch->downl);
2144 rwlock_init(&pch->upl);
2145
2146 spin_lock_bh(&pn->all_channels_lock);
2147 pch->file.index = ++pn->last_channel_index;
2148 list_add(&pch->list, &pn->new_channels);
2149 atomic_inc(&channel_count);
2150 spin_unlock_bh(&pn->all_channels_lock);
2151
2152 return 0;
2153 }
2154
2155 /*
2156 * Return the index of a channel.
2157 */
2158 int ppp_channel_index(struct ppp_channel *chan)
2159 {
2160 struct channel *pch = chan->ppp;
2161
2162 if (pch)
2163 return pch->file.index;
2164 return -1;
2165 }
2166
2167 /*
2168 * Return the PPP unit number to which a channel is connected.
2169 */
2170 int ppp_unit_number(struct ppp_channel *chan)
2171 {
2172 struct channel *pch = chan->ppp;
2173 int unit = -1;
2174
2175 if (pch) {
2176 read_lock_bh(&pch->upl);
2177 if (pch->ppp)
2178 unit = pch->ppp->file.index;
2179 read_unlock_bh(&pch->upl);
2180 }
2181 return unit;
2182 }
2183
2184 /*
2185 * Return the PPP device interface name of a channel.
2186 */
2187 char *ppp_dev_name(struct ppp_channel *chan)
2188 {
2189 struct channel *pch = chan->ppp;
2190 char *name = NULL;
2191
2192 if (pch) {
2193 read_lock_bh(&pch->upl);
2194 if (pch->ppp && pch->ppp->dev)
2195 name = pch->ppp->dev->name;
2196 read_unlock_bh(&pch->upl);
2197 }
2198 return name;
2199 }
2200
2201
2202 /*
2203 * Disconnect a channel from the generic layer.
2204 * This must be called in process context.
2205 */
2206 void
2207 ppp_unregister_channel(struct ppp_channel *chan)
2208 {
2209 struct channel *pch = chan->ppp;
2210 struct ppp_net *pn;
2211
2212 if (!pch)
2213 return; /* should never happen */
2214
2215 chan->ppp = NULL;
2216
2217 /*
2218 * This ensures that we have returned from any calls into the
2219 * the channel's start_xmit or ioctl routine before we proceed.
2220 */
2221 down_write(&pch->chan_sem);
2222 spin_lock_bh(&pch->downl);
2223 pch->chan = NULL;
2224 spin_unlock_bh(&pch->downl);
2225 up_write(&pch->chan_sem);
2226 ppp_disconnect_channel(pch);
2227
2228 pn = ppp_pernet(pch->chan_net);
2229 spin_lock_bh(&pn->all_channels_lock);
2230 list_del(&pch->list);
2231 spin_unlock_bh(&pn->all_channels_lock);
2232
2233 pch->file.dead = 1;
2234 wake_up_interruptible(&pch->file.rwait);
2235 if (atomic_dec_and_test(&pch->file.refcnt))
2236 ppp_destroy_channel(pch);
2237 }
2238
2239 /*
2240 * Callback from a channel when it can accept more to transmit.
2241 * This should be called at BH/softirq level, not interrupt level.
2242 */
2243 void
2244 ppp_output_wakeup(struct ppp_channel *chan)
2245 {
2246 struct channel *pch = chan->ppp;
2247
2248 if (!pch)
2249 return;
2250 ppp_channel_push(pch);
2251 }
2252
2253 /*
2254 * Compression control.
2255 */
2256
2257 /* Process the PPPIOCSCOMPRESS ioctl. */
2258 static int
2259 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2260 {
2261 int err;
2262 struct compressor *cp, *ocomp;
2263 struct ppp_option_data data;
2264 void *state, *ostate;
2265 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2266
2267 err = -EFAULT;
2268 if (copy_from_user(&data, (void __user *) arg, sizeof(data)) ||
2269 (data.length <= CCP_MAX_OPTION_LENGTH &&
2270 copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2271 goto out;
2272 err = -EINVAL;
2273 if (data.length > CCP_MAX_OPTION_LENGTH ||
2274 ccp_option[1] < 2 || ccp_option[1] > data.length)
2275 goto out;
2276
2277 cp = try_then_request_module(
2278 find_compressor(ccp_option[0]),
2279 "ppp-compress-%d", ccp_option[0]);
2280 if (!cp)
2281 goto out;
2282
2283 err = -ENOBUFS;
2284 if (data.transmit) {
2285 state = cp->comp_alloc(ccp_option, data.length);
2286 if (state) {
2287 ppp_xmit_lock(ppp);
2288 ppp->xstate &= ~SC_COMP_RUN;
2289 ocomp = ppp->xcomp;
2290 ostate = ppp->xc_state;
2291 ppp->xcomp = cp;
2292 ppp->xc_state = state;
2293 ppp_xmit_unlock(ppp);
2294 if (ostate) {
2295 ocomp->comp_free(ostate);
2296 module_put(ocomp->owner);
2297 }
2298 err = 0;
2299 } else
2300 module_put(cp->owner);
2301
2302 } else {
2303 state = cp->decomp_alloc(ccp_option, data.length);
2304 if (state) {
2305 ppp_recv_lock(ppp);
2306 ppp->rstate &= ~SC_DECOMP_RUN;
2307 ocomp = ppp->rcomp;
2308 ostate = ppp->rc_state;
2309 ppp->rcomp = cp;
2310 ppp->rc_state = state;
2311 ppp_recv_unlock(ppp);
2312 if (ostate) {
2313 ocomp->decomp_free(ostate);
2314 module_put(ocomp->owner);
2315 }
2316 err = 0;
2317 } else
2318 module_put(cp->owner);
2319 }
2320
2321 out:
2322 return err;
2323 }
2324
2325 /*
2326 * Look at a CCP packet and update our state accordingly.
2327 * We assume the caller has the xmit or recv path locked.
2328 */
2329 static void
2330 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2331 {
2332 unsigned char *dp;
2333 int len;
2334
2335 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2336 return; /* no header */
2337 dp = skb->data + 2;
2338
2339 switch (CCP_CODE(dp)) {
2340 case CCP_CONFREQ:
2341
2342 /* A ConfReq starts negotiation of compression
2343 * in one direction of transmission,
2344 * and hence brings it down...but which way?
2345 *
2346 * Remember:
2347 * A ConfReq indicates what the sender would like to receive
2348 */
2349 if(inbound)
2350 /* He is proposing what I should send */
2351 ppp->xstate &= ~SC_COMP_RUN;
2352 else
2353 /* I am proposing to what he should send */
2354 ppp->rstate &= ~SC_DECOMP_RUN;
2355
2356 break;
2357
2358 case CCP_TERMREQ:
2359 case CCP_TERMACK:
2360 /*
2361 * CCP is going down, both directions of transmission
2362 */
2363 ppp->rstate &= ~SC_DECOMP_RUN;
2364 ppp->xstate &= ~SC_COMP_RUN;
2365 break;
2366
2367 case CCP_CONFACK:
2368 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2369 break;
2370 len = CCP_LENGTH(dp);
2371 if (!pskb_may_pull(skb, len + 2))
2372 return; /* too short */
2373 dp += CCP_HDRLEN;
2374 len -= CCP_HDRLEN;
2375 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2376 break;
2377 if (inbound) {
2378 /* we will start receiving compressed packets */
2379 if (!ppp->rc_state)
2380 break;
2381 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2382 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2383 ppp->rstate |= SC_DECOMP_RUN;
2384 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2385 }
2386 } else {
2387 /* we will soon start sending compressed packets */
2388 if (!ppp->xc_state)
2389 break;
2390 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2391 ppp->file.index, 0, ppp->debug))
2392 ppp->xstate |= SC_COMP_RUN;
2393 }
2394 break;
2395
2396 case CCP_RESETACK:
2397 /* reset the [de]compressor */
2398 if ((ppp->flags & SC_CCP_UP) == 0)
2399 break;
2400 if (inbound) {
2401 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2402 ppp->rcomp->decomp_reset(ppp->rc_state);
2403 ppp->rstate &= ~SC_DC_ERROR;
2404 }
2405 } else {
2406 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2407 ppp->xcomp->comp_reset(ppp->xc_state);
2408 }
2409 break;
2410 }
2411 }
2412
2413 /* Free up compression resources. */
2414 static void
2415 ppp_ccp_closed(struct ppp *ppp)
2416 {
2417 void *xstate, *rstate;
2418 struct compressor *xcomp, *rcomp;
2419
2420 ppp_lock(ppp);
2421 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2422 ppp->xstate = 0;
2423 xcomp = ppp->xcomp;
2424 xstate = ppp->xc_state;
2425 ppp->xc_state = NULL;
2426 ppp->rstate = 0;
2427 rcomp = ppp->rcomp;
2428 rstate = ppp->rc_state;
2429 ppp->rc_state = NULL;
2430 ppp_unlock(ppp);
2431
2432 if (xstate) {
2433 xcomp->comp_free(xstate);
2434 module_put(xcomp->owner);
2435 }
2436 if (rstate) {
2437 rcomp->decomp_free(rstate);
2438 module_put(rcomp->owner);
2439 }
2440 }
2441
2442 /* List of compressors. */
2443 static LIST_HEAD(compressor_list);
2444 static DEFINE_SPINLOCK(compressor_list_lock);
2445
2446 struct compressor_entry {
2447 struct list_head list;
2448 struct compressor *comp;
2449 };
2450
2451 static struct compressor_entry *
2452 find_comp_entry(int proto)
2453 {
2454 struct compressor_entry *ce;
2455
2456 list_for_each_entry(ce, &compressor_list, list) {
2457 if (ce->comp->compress_proto == proto)
2458 return ce;
2459 }
2460 return NULL;
2461 }
2462
2463 /* Register a compressor */
2464 int
2465 ppp_register_compressor(struct compressor *cp)
2466 {
2467 struct compressor_entry *ce;
2468 int ret;
2469 spin_lock(&compressor_list_lock);
2470 ret = -EEXIST;
2471 if (find_comp_entry(cp->compress_proto))
2472 goto out;
2473 ret = -ENOMEM;
2474 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2475 if (!ce)
2476 goto out;
2477 ret = 0;
2478 ce->comp = cp;
2479 list_add(&ce->list, &compressor_list);
2480 out:
2481 spin_unlock(&compressor_list_lock);
2482 return ret;
2483 }
2484
2485 /* Unregister a compressor */
2486 void
2487 ppp_unregister_compressor(struct compressor *cp)
2488 {
2489 struct compressor_entry *ce;
2490
2491 spin_lock(&compressor_list_lock);
2492 ce = find_comp_entry(cp->compress_proto);
2493 if (ce && ce->comp == cp) {
2494 list_del(&ce->list);
2495 kfree(ce);
2496 }
2497 spin_unlock(&compressor_list_lock);
2498 }
2499
2500 /* Find a compressor. */
2501 static struct compressor *
2502 find_compressor(int type)
2503 {
2504 struct compressor_entry *ce;
2505 struct compressor *cp = NULL;
2506
2507 spin_lock(&compressor_list_lock);
2508 ce = find_comp_entry(type);
2509 if (ce) {
2510 cp = ce->comp;
2511 if (!try_module_get(cp->owner))
2512 cp = NULL;
2513 }
2514 spin_unlock(&compressor_list_lock);
2515 return cp;
2516 }
2517
2518 /*
2519 * Miscelleneous stuff.
2520 */
2521
2522 static void
2523 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2524 {
2525 struct slcompress *vj = ppp->vj;
2526
2527 memset(st, 0, sizeof(*st));
2528 st->p.ppp_ipackets = ppp->dev->stats.rx_packets;
2529 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2530 st->p.ppp_ibytes = ppp->dev->stats.rx_bytes;
2531 st->p.ppp_opackets = ppp->dev->stats.tx_packets;
2532 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2533 st->p.ppp_obytes = ppp->dev->stats.tx_bytes;
2534 if (!vj)
2535 return;
2536 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2537 st->vj.vjs_compressed = vj->sls_o_compressed;
2538 st->vj.vjs_searches = vj->sls_o_searches;
2539 st->vj.vjs_misses = vj->sls_o_misses;
2540 st->vj.vjs_errorin = vj->sls_i_error;
2541 st->vj.vjs_tossed = vj->sls_i_tossed;
2542 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2543 st->vj.vjs_compressedin = vj->sls_i_compressed;
2544 }
2545
2546 /*
2547 * Stuff for handling the lists of ppp units and channels
2548 * and for initialization.
2549 */
2550
2551 /*
2552 * Create a new ppp interface unit. Fails if it can't allocate memory
2553 * or if there is already a unit with the requested number.
2554 * unit == -1 means allocate a new number.
2555 */
2556 static struct ppp *
2557 ppp_create_interface(struct net *net, int unit, int *retp)
2558 {
2559 struct ppp *ppp;
2560 struct ppp_net *pn;
2561 struct net_device *dev = NULL;
2562 int ret = -ENOMEM;
2563 int i;
2564
2565 dev = alloc_netdev(sizeof(struct ppp), "", ppp_setup);
2566 if (!dev)
2567 goto out1;
2568
2569 pn = ppp_pernet(net);
2570
2571 ppp = netdev_priv(dev);
2572 ppp->dev = dev;
2573 ppp->mru = PPP_MRU;
2574 init_ppp_file(&ppp->file, INTERFACE);
2575 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2576 for (i = 0; i < NUM_NP; ++i)
2577 ppp->npmode[i] = NPMODE_PASS;
2578 INIT_LIST_HEAD(&ppp->channels);
2579 spin_lock_init(&ppp->rlock);
2580 spin_lock_init(&ppp->wlock);
2581 #ifdef CONFIG_PPP_MULTILINK
2582 ppp->minseq = -1;
2583 skb_queue_head_init(&ppp->mrq);
2584 #endif /* CONFIG_PPP_MULTILINK */
2585
2586 /*
2587 * drum roll: don't forget to set
2588 * the net device is belong to
2589 */
2590 dev_net_set(dev, net);
2591
2592 mutex_lock(&pn->all_ppp_mutex);
2593
2594 if (unit < 0) {
2595 unit = unit_get(&pn->units_idr, ppp);
2596 if (unit < 0) {
2597 ret = unit;
2598 goto out2;
2599 }
2600 } else {
2601 ret = -EEXIST;
2602 if (unit_find(&pn->units_idr, unit))
2603 goto out2; /* unit already exists */
2604 /*
2605 * if caller need a specified unit number
2606 * lets try to satisfy him, otherwise --
2607 * he should better ask us for new unit number
2608 *
2609 * NOTE: yes I know that returning EEXIST it's not
2610 * fair but at least pppd will ask us to allocate
2611 * new unit in this case so user is happy :)
2612 */
2613 unit = unit_set(&pn->units_idr, ppp, unit);
2614 if (unit < 0)
2615 goto out2;
2616 }
2617
2618 /* Initialize the new ppp unit */
2619 ppp->file.index = unit;
2620 sprintf(dev->name, "ppp%d", unit);
2621
2622 ret = register_netdev(dev);
2623 if (ret != 0) {
2624 unit_put(&pn->units_idr, unit);
2625 printk(KERN_ERR "PPP: couldn't register device %s (%d)\n",
2626 dev->name, ret);
2627 goto out2;
2628 }
2629
2630 ppp->ppp_net = net;
2631
2632 atomic_inc(&ppp_unit_count);
2633 mutex_unlock(&pn->all_ppp_mutex);
2634
2635 *retp = 0;
2636 return ppp;
2637
2638 out2:
2639 mutex_unlock(&pn->all_ppp_mutex);
2640 free_netdev(dev);
2641 out1:
2642 *retp = ret;
2643 return NULL;
2644 }
2645
2646 /*
2647 * Initialize a ppp_file structure.
2648 */
2649 static void
2650 init_ppp_file(struct ppp_file *pf, int kind)
2651 {
2652 pf->kind = kind;
2653 skb_queue_head_init(&pf->xq);
2654 skb_queue_head_init(&pf->rq);
2655 atomic_set(&pf->refcnt, 1);
2656 init_waitqueue_head(&pf->rwait);
2657 }
2658
2659 /*
2660 * Take down a ppp interface unit - called when the owning file
2661 * (the one that created the unit) is closed or detached.
2662 */
2663 static void ppp_shutdown_interface(struct ppp *ppp)
2664 {
2665 struct ppp_net *pn;
2666
2667 pn = ppp_pernet(ppp->ppp_net);
2668 mutex_lock(&pn->all_ppp_mutex);
2669
2670 /* This will call dev_close() for us. */
2671 ppp_lock(ppp);
2672 if (!ppp->closing) {
2673 ppp->closing = 1;
2674 ppp_unlock(ppp);
2675 unregister_netdev(ppp->dev);
2676 unit_put(&pn->units_idr, ppp->file.index);
2677 } else
2678 ppp_unlock(ppp);
2679
2680 ppp->file.dead = 1;
2681 ppp->owner = NULL;
2682 wake_up_interruptible(&ppp->file.rwait);
2683
2684 mutex_unlock(&pn->all_ppp_mutex);
2685 }
2686
2687 /*
2688 * Free the memory used by a ppp unit. This is only called once
2689 * there are no channels connected to the unit and no file structs
2690 * that reference the unit.
2691 */
2692 static void ppp_destroy_interface(struct ppp *ppp)
2693 {
2694 atomic_dec(&ppp_unit_count);
2695
2696 if (!ppp->file.dead || ppp->n_channels) {
2697 /* "can't happen" */
2698 printk(KERN_ERR "ppp: destroying ppp struct %p but dead=%d "
2699 "n_channels=%d !\n", ppp, ppp->file.dead,
2700 ppp->n_channels);
2701 return;
2702 }
2703
2704 ppp_ccp_closed(ppp);
2705 if (ppp->vj) {
2706 slhc_free(ppp->vj);
2707 ppp->vj = NULL;
2708 }
2709 skb_queue_purge(&ppp->file.xq);
2710 skb_queue_purge(&ppp->file.rq);
2711 #ifdef CONFIG_PPP_MULTILINK
2712 skb_queue_purge(&ppp->mrq);
2713 #endif /* CONFIG_PPP_MULTILINK */
2714 #ifdef CONFIG_PPP_FILTER
2715 kfree(ppp->pass_filter);
2716 ppp->pass_filter = NULL;
2717 kfree(ppp->active_filter);
2718 ppp->active_filter = NULL;
2719 #endif /* CONFIG_PPP_FILTER */
2720
2721 kfree_skb(ppp->xmit_pending);
2722
2723 free_netdev(ppp->dev);
2724 }
2725
2726 /*
2727 * Locate an existing ppp unit.
2728 * The caller should have locked the all_ppp_mutex.
2729 */
2730 static struct ppp *
2731 ppp_find_unit(struct ppp_net *pn, int unit)
2732 {
2733 return unit_find(&pn->units_idr, unit);
2734 }
2735
2736 /*
2737 * Locate an existing ppp channel.
2738 * The caller should have locked the all_channels_lock.
2739 * First we look in the new_channels list, then in the
2740 * all_channels list. If found in the new_channels list,
2741 * we move it to the all_channels list. This is for speed
2742 * when we have a lot of channels in use.
2743 */
2744 static struct channel *
2745 ppp_find_channel(struct ppp_net *pn, int unit)
2746 {
2747 struct channel *pch;
2748
2749 list_for_each_entry(pch, &pn->new_channels, list) {
2750 if (pch->file.index == unit) {
2751 list_move(&pch->list, &pn->all_channels);
2752 return pch;
2753 }
2754 }
2755
2756 list_for_each_entry(pch, &pn->all_channels, list) {
2757 if (pch->file.index == unit)
2758 return pch;
2759 }
2760
2761 return NULL;
2762 }
2763
2764 /*
2765 * Connect a PPP channel to a PPP interface unit.
2766 */
2767 static int
2768 ppp_connect_channel(struct channel *pch, int unit)
2769 {
2770 struct ppp *ppp;
2771 struct ppp_net *pn;
2772 int ret = -ENXIO;
2773 int hdrlen;
2774
2775 pn = ppp_pernet(pch->chan_net);
2776
2777 mutex_lock(&pn->all_ppp_mutex);
2778 ppp = ppp_find_unit(pn, unit);
2779 if (!ppp)
2780 goto out;
2781 write_lock_bh(&pch->upl);
2782 ret = -EINVAL;
2783 if (pch->ppp)
2784 goto outl;
2785
2786 ppp_lock(ppp);
2787 if (pch->file.hdrlen > ppp->file.hdrlen)
2788 ppp->file.hdrlen = pch->file.hdrlen;
2789 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2790 if (hdrlen > ppp->dev->hard_header_len)
2791 ppp->dev->hard_header_len = hdrlen;
2792 list_add_tail(&pch->clist, &ppp->channels);
2793 ++ppp->n_channels;
2794 pch->ppp = ppp;
2795 atomic_inc(&ppp->file.refcnt);
2796 ppp_unlock(ppp);
2797 ret = 0;
2798
2799 outl:
2800 write_unlock_bh(&pch->upl);
2801 out:
2802 mutex_unlock(&pn->all_ppp_mutex);
2803 return ret;
2804 }
2805
2806 /*
2807 * Disconnect a channel from its ppp unit.
2808 */
2809 static int
2810 ppp_disconnect_channel(struct channel *pch)
2811 {
2812 struct ppp *ppp;
2813 int err = -EINVAL;
2814
2815 write_lock_bh(&pch->upl);
2816 ppp = pch->ppp;
2817 pch->ppp = NULL;
2818 write_unlock_bh(&pch->upl);
2819 if (ppp) {
2820 /* remove it from the ppp unit's list */
2821 ppp_lock(ppp);
2822 list_del(&pch->clist);
2823 if (--ppp->n_channels == 0)
2824 wake_up_interruptible(&ppp->file.rwait);
2825 ppp_unlock(ppp);
2826 if (atomic_dec_and_test(&ppp->file.refcnt))
2827 ppp_destroy_interface(ppp);
2828 err = 0;
2829 }
2830 return err;
2831 }
2832
2833 /*
2834 * Free up the resources used by a ppp channel.
2835 */
2836 static void ppp_destroy_channel(struct channel *pch)
2837 {
2838 atomic_dec(&channel_count);
2839
2840 if (!pch->file.dead) {
2841 /* "can't happen" */
2842 printk(KERN_ERR "ppp: destroying undead channel %p !\n",
2843 pch);
2844 return;
2845 }
2846 skb_queue_purge(&pch->file.xq);
2847 skb_queue_purge(&pch->file.rq);
2848 kfree(pch);
2849 }
2850
2851 static void __exit ppp_cleanup(void)
2852 {
2853 /* should never happen */
2854 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2855 printk(KERN_ERR "PPP: removing module but units remain!\n");
2856 unregister_chrdev(PPP_MAJOR, "ppp");
2857 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
2858 class_destroy(ppp_class);
2859 unregister_pernet_device(&ppp_net_ops);
2860 }
2861
2862 /*
2863 * Units handling. Caller must protect concurrent access
2864 * by holding all_ppp_mutex
2865 */
2866
2867 static int __unit_alloc(struct idr *p, void *ptr, int n)
2868 {
2869 int unit, err;
2870
2871 again:
2872 if (!idr_pre_get(p, GFP_KERNEL)) {
2873 printk(KERN_ERR "PPP: No free memory for idr\n");
2874 return -ENOMEM;
2875 }
2876
2877 err = idr_get_new_above(p, ptr, n, &unit);
2878 if (err < 0) {
2879 if (err == -EAGAIN)
2880 goto again;
2881 return err;
2882 }
2883
2884 return unit;
2885 }
2886
2887 /* associate pointer with specified number */
2888 static int unit_set(struct idr *p, void *ptr, int n)
2889 {
2890 int unit;
2891
2892 unit = __unit_alloc(p, ptr, n);
2893 if (unit < 0)
2894 return unit;
2895 else if (unit != n) {
2896 idr_remove(p, unit);
2897 return -EINVAL;
2898 }
2899
2900 return unit;
2901 }
2902
2903 /* get new free unit number and associate pointer with it */
2904 static int unit_get(struct idr *p, void *ptr)
2905 {
2906 return __unit_alloc(p, ptr, 0);
2907 }
2908
2909 /* put unit number back to a pool */
2910 static void unit_put(struct idr *p, int n)
2911 {
2912 idr_remove(p, n);
2913 }
2914
2915 /* get pointer associated with the number */
2916 static void *unit_find(struct idr *p, int n)
2917 {
2918 return idr_find(p, n);
2919 }
2920
2921 /* Module/initialization stuff */
2922
2923 module_init(ppp_init);
2924 module_exit(ppp_cleanup);
2925
2926 EXPORT_SYMBOL(ppp_register_net_channel);
2927 EXPORT_SYMBOL(ppp_register_channel);
2928 EXPORT_SYMBOL(ppp_unregister_channel);
2929 EXPORT_SYMBOL(ppp_channel_index);
2930 EXPORT_SYMBOL(ppp_unit_number);
2931 EXPORT_SYMBOL(ppp_dev_name);
2932 EXPORT_SYMBOL(ppp_input);
2933 EXPORT_SYMBOL(ppp_input_error);
2934 EXPORT_SYMBOL(ppp_output_wakeup);
2935 EXPORT_SYMBOL(ppp_register_compressor);
2936 EXPORT_SYMBOL(ppp_unregister_compressor);
2937 MODULE_LICENSE("GPL");
2938 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
2939 MODULE_ALIAS("devname:ppp");
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree