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Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / net / ppp_generic.c
blobe7b4187da057d3bf32e48077b70080d7af9286e4
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/smp_lock.h>
44 #include <linux/spinlock.h>
45 #include <linux/rwsem.h>
46 #include <linux/stddef.h>
47 #include <linux/device.h>
48 #include <linux/mutex.h>
49 #include <linux/slab.h>
50 #include <net/slhc_vj.h>
51 #include <asm/atomic.h>
52
53 #include <linux/nsproxy.h>
54 #include <net/net_namespace.h>
55 #include <net/netns/generic.h>
56
57 #define PPP_VERSION "2.4.2"
58
59 /*
60 * Network protocols we support.
61 */
62 #define NP_IP 0 /* Internet Protocol V4 */
63 #define NP_IPV6 1 /* Internet Protocol V6 */
64 #define NP_IPX 2 /* IPX protocol */
65 #define NP_AT 3 /* Appletalk protocol */
66 #define NP_MPLS_UC 4 /* MPLS unicast */
67 #define NP_MPLS_MC 5 /* MPLS multicast */
68 #define NUM_NP 6 /* Number of NPs. */
69
70 #define MPHDRLEN 6 /* multilink protocol header length */
71 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */
72
73 /*
74 * An instance of /dev/ppp can be associated with either a ppp
75 * interface unit or a ppp channel. In both cases, file->private_data
76 * points to one of these.
77 */
78 struct ppp_file {
79 enum {
80 INTERFACE=1, CHANNEL
81 } kind;
82 struct sk_buff_head xq; /* pppd transmit queue */
83 struct sk_buff_head rq; /* receive queue for pppd */
84 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */
85 atomic_t refcnt; /* # refs (incl /dev/ppp attached) */
86 int hdrlen; /* space to leave for headers */
87 int index; /* interface unit / channel number */
88 int dead; /* unit/channel has been shut down */
89 };
90
91 #define PF_TO_X(pf, X) container_of(pf, X, file)
92
93 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
94 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
95
96 /*
97 * Data structure describing one ppp unit.
98 * A ppp unit corresponds to a ppp network interface device
99 * and represents a multilink bundle.
100 * It can have 0 or more ppp channels connected to it.
101 */
102 struct ppp {
103 struct ppp_file file; /* stuff for read/write/poll 0 */
104 struct file *owner; /* file that owns this unit 48 */
105 struct list_head channels; /* list of attached channels 4c */
106 int n_channels; /* how many channels are attached 54 */
107 spinlock_t rlock; /* lock for receive side 58 */
108 spinlock_t wlock; /* lock for transmit side 5c */
109 int mru; /* max receive unit 60 */
110 unsigned int flags; /* control bits 64 */
111 unsigned int xstate; /* transmit state bits 68 */
112 unsigned int rstate; /* receive state bits 6c */
113 int debug; /* debug flags 70 */
114 struct slcompress *vj; /* state for VJ header compression */
115 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
116 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
117 struct compressor *xcomp; /* transmit packet compressor 8c */
118 void *xc_state; /* its internal state 90 */
119 struct compressor *rcomp; /* receive decompressor 94 */
120 void *rc_state; /* its internal state 98 */
121 unsigned long last_xmit; /* jiffies when last pkt sent 9c */
122 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
123 struct net_device *dev; /* network interface device a4 */
124 int closing; /* is device closing down? a8 */
125 #ifdef CONFIG_PPP_MULTILINK
126 int nxchan; /* next channel to send something on */
127 u32 nxseq; /* next sequence number to send */
128 int mrru; /* MP: max reconst. receive unit */
129 u32 nextseq; /* MP: seq no of next packet */
130 u32 minseq; /* MP: min of most recent seqnos */
131 struct sk_buff_head mrq; /* MP: receive reconstruction queue */
132 #endif /* CONFIG_PPP_MULTILINK */
133 #ifdef CONFIG_PPP_FILTER
134 struct sock_filter *pass_filter; /* filter for packets to pass */
135 struct sock_filter *active_filter;/* filter for pkts to reset idle */
136 unsigned pass_len, active_len;
137 #endif /* CONFIG_PPP_FILTER */
138 struct net *ppp_net; /* the net we belong to */
139 };
140
141 /*
142 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
143 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
144 * SC_MUST_COMP
145 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
146 * Bits in xstate: SC_COMP_RUN
147 */
148 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
149 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
150 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
151
152 /*
153 * Private data structure for each channel.
154 * This includes the data structure used for multilink.
155 */
156 struct channel {
157 struct ppp_file file; /* stuff for read/write/poll */
158 struct list_head list; /* link in all/new_channels list */
159 struct ppp_channel *chan; /* public channel data structure */
160 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
161 spinlock_t downl; /* protects `chan', file.xq dequeue */
162 struct ppp *ppp; /* ppp unit we're connected to */
163 struct net *chan_net; /* the net channel belongs to */
164 struct list_head clist; /* link in list of channels per unit */
165 rwlock_t upl; /* protects `ppp' */
166 #ifdef CONFIG_PPP_MULTILINK
167 u8 avail; /* flag used in multilink stuff */
168 u8 had_frag; /* >= 1 fragments have been sent */
169 u32 lastseq; /* MP: last sequence # received */
170 int speed; /* speed of the corresponding ppp channel*/
171 #endif /* CONFIG_PPP_MULTILINK */
172 };
173
174 /*
175 * SMP locking issues:
176 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
177 * list and the ppp.n_channels field, you need to take both locks
178 * before you modify them.
179 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
180 * channel.downl.
181 */
182
183 static 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 cycle_kernel_lock();
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 lock_kernel();
586 if (pf->kind == INTERFACE) {
587 ppp = PF_TO_PPP(pf);
588 if (file == ppp->owner)
589 ppp_shutdown_interface(ppp);
590 }
591 if (atomic_long_read(&file->f_count) <= 2) {
592 ppp_release(NULL, file);
593 err = 0;
594 } else
595 printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%ld\n",
596 atomic_long_read(&file->f_count));
597 unlock_kernel();
598 return err;
599 }
600
601 if (pf->kind == CHANNEL) {
602 struct channel *pch;
603 struct ppp_channel *chan;
604
605 lock_kernel();
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 unlock_kernel();
628 return err;
629 }
630
631 if (pf->kind != INTERFACE) {
632 /* can't happen */
633 printk(KERN_ERR "PPP: not interface or channel??\n");
634 return -EINVAL;
635 }
636
637 lock_kernel();
638 ppp = PF_TO_PPP(pf);
639 switch (cmd) {
640 case PPPIOCSMRU:
641 if (get_user(val, p))
642 break;
643 ppp->mru = val;
644 err = 0;
645 break;
646
647 case PPPIOCSFLAGS:
648 if (get_user(val, p))
649 break;
650 ppp_lock(ppp);
651 cflags = ppp->flags & ~val;
652 ppp->flags = val & SC_FLAG_BITS;
653 ppp_unlock(ppp);
654 if (cflags & SC_CCP_OPEN)
655 ppp_ccp_closed(ppp);
656 err = 0;
657 break;
658
659 case PPPIOCGFLAGS:
660 val = ppp->flags | ppp->xstate | ppp->rstate;
661 if (put_user(val, p))
662 break;
663 err = 0;
664 break;
665
666 case PPPIOCSCOMPRESS:
667 err = ppp_set_compress(ppp, arg);
668 break;
669
670 case PPPIOCGUNIT:
671 if (put_user(ppp->file.index, p))
672 break;
673 err = 0;
674 break;
675
676 case PPPIOCSDEBUG:
677 if (get_user(val, p))
678 break;
679 ppp->debug = val;
680 err = 0;
681 break;
682
683 case PPPIOCGDEBUG:
684 if (put_user(ppp->debug, p))
685 break;
686 err = 0;
687 break;
688
689 case PPPIOCGIDLE:
690 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
691 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
692 if (copy_to_user(argp, &idle, sizeof(idle)))
693 break;
694 err = 0;
695 break;
696
697 case PPPIOCSMAXCID:
698 if (get_user(val, p))
699 break;
700 val2 = 15;
701 if ((val >> 16) != 0) {
702 val2 = val >> 16;
703 val &= 0xffff;
704 }
705 vj = slhc_init(val2+1, val+1);
706 if (!vj) {
707 printk(KERN_ERR "PPP: no memory (VJ compressor)\n");
708 err = -ENOMEM;
709 break;
710 }
711 ppp_lock(ppp);
712 if (ppp->vj)
713 slhc_free(ppp->vj);
714 ppp->vj = vj;
715 ppp_unlock(ppp);
716 err = 0;
717 break;
718
719 case PPPIOCGNPMODE:
720 case PPPIOCSNPMODE:
721 if (copy_from_user(&npi, argp, sizeof(npi)))
722 break;
723 err = proto_to_npindex(npi.protocol);
724 if (err < 0)
725 break;
726 i = err;
727 if (cmd == PPPIOCGNPMODE) {
728 err = -EFAULT;
729 npi.mode = ppp->npmode[i];
730 if (copy_to_user(argp, &npi, sizeof(npi)))
731 break;
732 } else {
733 ppp->npmode[i] = npi.mode;
734 /* we may be able to transmit more packets now (??) */
735 netif_wake_queue(ppp->dev);
736 }
737 err = 0;
738 break;
739
740 #ifdef CONFIG_PPP_FILTER
741 case PPPIOCSPASS:
742 {
743 struct sock_filter *code;
744 err = get_filter(argp, &code);
745 if (err >= 0) {
746 ppp_lock(ppp);
747 kfree(ppp->pass_filter);
748 ppp->pass_filter = code;
749 ppp->pass_len = err;
750 ppp_unlock(ppp);
751 err = 0;
752 }
753 break;
754 }
755 case PPPIOCSACTIVE:
756 {
757 struct sock_filter *code;
758 err = get_filter(argp, &code);
759 if (err >= 0) {
760 ppp_lock(ppp);
761 kfree(ppp->active_filter);
762 ppp->active_filter = code;
763 ppp->active_len = err;
764 ppp_unlock(ppp);
765 err = 0;
766 }
767 break;
768 }
769 #endif /* CONFIG_PPP_FILTER */
770
771 #ifdef CONFIG_PPP_MULTILINK
772 case PPPIOCSMRRU:
773 if (get_user(val, p))
774 break;
775 ppp_recv_lock(ppp);
776 ppp->mrru = val;
777 ppp_recv_unlock(ppp);
778 err = 0;
779 break;
780 #endif /* CONFIG_PPP_MULTILINK */
781
782 default:
783 err = -ENOTTY;
784 }
785 unlock_kernel();
786 return err;
787 }
788
789 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
790 struct file *file, unsigned int cmd, unsigned long arg)
791 {
792 int unit, err = -EFAULT;
793 struct ppp *ppp;
794 struct channel *chan;
795 struct ppp_net *pn;
796 int __user *p = (int __user *)arg;
797
798 lock_kernel();
799 switch (cmd) {
800 case PPPIOCNEWUNIT:
801 /* Create a new ppp unit */
802 if (get_user(unit, p))
803 break;
804 ppp = ppp_create_interface(net, unit, &err);
805 if (!ppp)
806 break;
807 file->private_data = &ppp->file;
808 ppp->owner = file;
809 err = -EFAULT;
810 if (put_user(ppp->file.index, p))
811 break;
812 err = 0;
813 break;
814
815 case PPPIOCATTACH:
816 /* Attach to an existing ppp unit */
817 if (get_user(unit, p))
818 break;
819 err = -ENXIO;
820 pn = ppp_pernet(net);
821 mutex_lock(&pn->all_ppp_mutex);
822 ppp = ppp_find_unit(pn, unit);
823 if (ppp) {
824 atomic_inc(&ppp->file.refcnt);
825 file->private_data = &ppp->file;
826 err = 0;
827 }
828 mutex_unlock(&pn->all_ppp_mutex);
829 break;
830
831 case PPPIOCATTCHAN:
832 if (get_user(unit, p))
833 break;
834 err = -ENXIO;
835 pn = ppp_pernet(net);
836 spin_lock_bh(&pn->all_channels_lock);
837 chan = ppp_find_channel(pn, unit);
838 if (chan) {
839 atomic_inc(&chan->file.refcnt);
840 file->private_data = &chan->file;
841 err = 0;
842 }
843 spin_unlock_bh(&pn->all_channels_lock);
844 break;
845
846 default:
847 err = -ENOTTY;
848 }
849 unlock_kernel();
850 return err;
851 }
852
853 static const struct file_operations ppp_device_fops = {
854 .owner = THIS_MODULE,
855 .read = ppp_read,
856 .write = ppp_write,
857 .poll = ppp_poll,
858 .unlocked_ioctl = ppp_ioctl,
859 .open = ppp_open,
860 .release = ppp_release
861 };
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 /*
1289 * Divide a packet to be transmitted into fragments and
1290 * send them out the individual links.
1291 */
1292 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1293 {
1294 int len, totlen;
1295 int i, bits, hdrlen, mtu;
1296 int flen;
1297 int navail, nfree, nzero;
1298 int nbigger;
1299 int totspeed;
1300 int totfree;
1301 unsigned char *p, *q;
1302 struct list_head *list;
1303 struct channel *pch;
1304 struct sk_buff *frag;
1305 struct ppp_channel *chan;
1306
1307 totspeed = 0; /*total bitrate of the bundle*/
1308 nfree = 0; /* # channels which have no packet already queued */
1309 navail = 0; /* total # of usable channels (not deregistered) */
1310 nzero = 0; /* number of channels with zero speed associated*/
1311 totfree = 0; /*total # of channels available and
1312 *having no queued packets before
1313 *starting the fragmentation*/
1314
1315 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1316 i = 0;
1317 list_for_each_entry(pch, &ppp->channels, clist) {
1318 navail += pch->avail = (pch->chan != NULL);
1319 pch->speed = pch->chan->speed;
1320 if (pch->avail) {
1321 if (skb_queue_empty(&pch->file.xq) ||
1322 !pch->had_frag) {
1323 if (pch->speed == 0)
1324 nzero++;
1325 else
1326 totspeed += pch->speed;
1327
1328 pch->avail = 2;
1329 ++nfree;
1330 ++totfree;
1331 }
1332 if (!pch->had_frag && i < ppp->nxchan)
1333 ppp->nxchan = i;
1334 }
1335 ++i;
1336 }
1337 /*
1338 * Don't start sending this packet unless at least half of
1339 * the channels are free. This gives much better TCP
1340 * performance if we have a lot of channels.
1341 */
1342 if (nfree == 0 || nfree < navail / 2)
1343 return 0; /* can't take now, leave it in xmit_pending */
1344
1345 /* Do protocol field compression (XXX this should be optional) */
1346 p = skb->data;
1347 len = skb->len;
1348 if (*p == 0) {
1349 ++p;
1350 --len;
1351 }
1352
1353 totlen = len;
1354 nbigger = len % nfree;
1355
1356 /* skip to the channel after the one we last used
1357 and start at that one */
1358 list = &ppp->channels;
1359 for (i = 0; i < ppp->nxchan; ++i) {
1360 list = list->next;
1361 if (list == &ppp->channels) {
1362 i = 0;
1363 break;
1364 }
1365 }
1366
1367 /* create a fragment for each channel */
1368 bits = B;
1369 while (len > 0) {
1370 list = list->next;
1371 if (list == &ppp->channels) {
1372 i = 0;
1373 continue;
1374 }
1375 pch = list_entry(list, struct channel, clist);
1376 ++i;
1377 if (!pch->avail)
1378 continue;
1379
1380 /*
1381 * Skip this channel if it has a fragment pending already and
1382 * we haven't given a fragment to all of the free channels.
1383 */
1384 if (pch->avail == 1) {
1385 if (nfree > 0)
1386 continue;
1387 } else {
1388 pch->avail = 1;
1389 }
1390
1391 /* check the channel's mtu and whether it is still attached. */
1392 spin_lock_bh(&pch->downl);
1393 if (pch->chan == NULL) {
1394 /* can't use this channel, it's being deregistered */
1395 if (pch->speed == 0)
1396 nzero--;
1397 else
1398 totspeed -= pch->speed;
1399
1400 spin_unlock_bh(&pch->downl);
1401 pch->avail = 0;
1402 totlen = len;
1403 totfree--;
1404 nfree--;
1405 if (--navail == 0)
1406 break;
1407 continue;
1408 }
1409
1410 /*
1411 *if the channel speed is not set divide
1412 *the packet evenly among the free channels;
1413 *otherwise divide it according to the speed
1414 *of the channel we are going to transmit on
1415 */
1416 flen = len;
1417 if (nfree > 0) {
1418 if (pch->speed == 0) {
1419 flen = len/nfree;
1420 if (nbigger > 0) {
1421 flen++;
1422 nbigger--;
1423 }
1424 } else {
1425 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
1426 ((totspeed*totfree)/pch->speed)) - hdrlen;
1427 if (nbigger > 0) {
1428 flen += ((totfree - nzero)*pch->speed)/totspeed;
1429 nbigger -= ((totfree - nzero)*pch->speed)/
1430 totspeed;
1431 }
1432 }
1433 nfree--;
1434 }
1435
1436 /*
1437 *check if we are on the last channel or
1438 *we exceded the lenght of the data to
1439 *fragment
1440 */
1441 if ((nfree <= 0) || (flen > len))
1442 flen = len;
1443 /*
1444 *it is not worth to tx on slow channels:
1445 *in that case from the resulting flen according to the
1446 *above formula will be equal or less than zero.
1447 *Skip the channel in this case
1448 */
1449 if (flen <= 0) {
1450 pch->avail = 2;
1451 spin_unlock_bh(&pch->downl);
1452 continue;
1453 }
1454
1455 mtu = pch->chan->mtu - hdrlen;
1456 if (mtu < 4)
1457 mtu = 4;
1458 if (flen > mtu)
1459 flen = mtu;
1460 if (flen == len)
1461 bits |= E;
1462 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1463 if (!frag)
1464 goto noskb;
1465 q = skb_put(frag, flen + hdrlen);
1466
1467 /* make the MP header */
1468 q[0] = PPP_MP >> 8;
1469 q[1] = PPP_MP;
1470 if (ppp->flags & SC_MP_XSHORTSEQ) {
1471 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1472 q[3] = ppp->nxseq;
1473 } else {
1474 q[2] = bits;
1475 q[3] = ppp->nxseq >> 16;
1476 q[4] = ppp->nxseq >> 8;
1477 q[5] = ppp->nxseq;
1478 }
1479
1480 memcpy(q + hdrlen, p, flen);
1481
1482 /* try to send it down the channel */
1483 chan = pch->chan;
1484 if (!skb_queue_empty(&pch->file.xq) ||
1485 !chan->ops->start_xmit(chan, frag))
1486 skb_queue_tail(&pch->file.xq, frag);
1487 pch->had_frag = 1;
1488 p += flen;
1489 len -= flen;
1490 ++ppp->nxseq;
1491 bits = 0;
1492 spin_unlock_bh(&pch->downl);
1493 }
1494 ppp->nxchan = i;
1495
1496 return 1;
1497
1498 noskb:
1499 spin_unlock_bh(&pch->downl);
1500 if (ppp->debug & 1)
1501 printk(KERN_ERR "PPP: no memory (fragment)\n");
1502 ++ppp->dev->stats.tx_errors;
1503 ++ppp->nxseq;
1504 return 1; /* abandon the frame */
1505 }
1506 #endif /* CONFIG_PPP_MULTILINK */
1507
1508 /*
1509 * Try to send data out on a channel.
1510 */
1511 static void
1512 ppp_channel_push(struct channel *pch)
1513 {
1514 struct sk_buff *skb;
1515 struct ppp *ppp;
1516
1517 spin_lock_bh(&pch->downl);
1518 if (pch->chan) {
1519 while (!skb_queue_empty(&pch->file.xq)) {
1520 skb = skb_dequeue(&pch->file.xq);
1521 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1522 /* put the packet back and try again later */
1523 skb_queue_head(&pch->file.xq, skb);
1524 break;
1525 }
1526 }
1527 } else {
1528 /* channel got deregistered */
1529 skb_queue_purge(&pch->file.xq);
1530 }
1531 spin_unlock_bh(&pch->downl);
1532 /* see if there is anything from the attached unit to be sent */
1533 if (skb_queue_empty(&pch->file.xq)) {
1534 read_lock_bh(&pch->upl);
1535 ppp = pch->ppp;
1536 if (ppp)
1537 ppp_xmit_process(ppp);
1538 read_unlock_bh(&pch->upl);
1539 }
1540 }
1541
1542 /*
1543 * Receive-side routines.
1544 */
1545
1546 /* misuse a few fields of the skb for MP reconstruction */
1547 #define sequence priority
1548 #define BEbits cb[0]
1549
1550 static inline void
1551 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1552 {
1553 ppp_recv_lock(ppp);
1554 if (!ppp->closing)
1555 ppp_receive_frame(ppp, skb, pch);
1556 else
1557 kfree_skb(skb);
1558 ppp_recv_unlock(ppp);
1559 }
1560
1561 void
1562 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1563 {
1564 struct channel *pch = chan->ppp;
1565 int proto;
1566
1567 if (!pch) {
1568 kfree_skb(skb);
1569 return;
1570 }
1571
1572 read_lock_bh(&pch->upl);
1573 if (!pskb_may_pull(skb, 2)) {
1574 kfree_skb(skb);
1575 if (pch->ppp) {
1576 ++pch->ppp->dev->stats.rx_length_errors;
1577 ppp_receive_error(pch->ppp);
1578 }
1579 goto done;
1580 }
1581
1582 proto = PPP_PROTO(skb);
1583 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1584 /* put it on the channel queue */
1585 skb_queue_tail(&pch->file.rq, skb);
1586 /* drop old frames if queue too long */
1587 while (pch->file.rq.qlen > PPP_MAX_RQLEN &&
1588 (skb = skb_dequeue(&pch->file.rq)))
1589 kfree_skb(skb);
1590 wake_up_interruptible(&pch->file.rwait);
1591 } else {
1592 ppp_do_recv(pch->ppp, skb, pch);
1593 }
1594
1595 done:
1596 read_unlock_bh(&pch->upl);
1597 }
1598
1599 /* Put a 0-length skb in the receive queue as an error indication */
1600 void
1601 ppp_input_error(struct ppp_channel *chan, int code)
1602 {
1603 struct channel *pch = chan->ppp;
1604 struct sk_buff *skb;
1605
1606 if (!pch)
1607 return;
1608
1609 read_lock_bh(&pch->upl);
1610 if (pch->ppp) {
1611 skb = alloc_skb(0, GFP_ATOMIC);
1612 if (skb) {
1613 skb->len = 0; /* probably unnecessary */
1614 skb->cb[0] = code;
1615 ppp_do_recv(pch->ppp, skb, pch);
1616 }
1617 }
1618 read_unlock_bh(&pch->upl);
1619 }
1620
1621 /*
1622 * We come in here to process a received frame.
1623 * The receive side of the ppp unit is locked.
1624 */
1625 static void
1626 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1627 {
1628 /* note: a 0-length skb is used as an error indication */
1629 if (skb->len > 0) {
1630 #ifdef CONFIG_PPP_MULTILINK
1631 /* XXX do channel-level decompression here */
1632 if (PPP_PROTO(skb) == PPP_MP)
1633 ppp_receive_mp_frame(ppp, skb, pch);
1634 else
1635 #endif /* CONFIG_PPP_MULTILINK */
1636 ppp_receive_nonmp_frame(ppp, skb);
1637 } else {
1638 kfree_skb(skb);
1639 ppp_receive_error(ppp);
1640 }
1641 }
1642
1643 static void
1644 ppp_receive_error(struct ppp *ppp)
1645 {
1646 ++ppp->dev->stats.rx_errors;
1647 if (ppp->vj)
1648 slhc_toss(ppp->vj);
1649 }
1650
1651 static void
1652 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1653 {
1654 struct sk_buff *ns;
1655 int proto, len, npi;
1656
1657 /*
1658 * Decompress the frame, if compressed.
1659 * Note that some decompressors need to see uncompressed frames
1660 * that come in as well as compressed frames.
1661 */
1662 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) &&
1663 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1664 skb = ppp_decompress_frame(ppp, skb);
1665
1666 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1667 goto err;
1668
1669 proto = PPP_PROTO(skb);
1670 switch (proto) {
1671 case PPP_VJC_COMP:
1672 /* decompress VJ compressed packets */
1673 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1674 goto err;
1675
1676 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1677 /* copy to a new sk_buff with more tailroom */
1678 ns = dev_alloc_skb(skb->len + 128);
1679 if (!ns) {
1680 printk(KERN_ERR"PPP: no memory (VJ decomp)\n");
1681 goto err;
1682 }
1683 skb_reserve(ns, 2);
1684 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1685 kfree_skb(skb);
1686 skb = ns;
1687 }
1688 else
1689 skb->ip_summed = CHECKSUM_NONE;
1690
1691 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1692 if (len <= 0) {
1693 printk(KERN_DEBUG "PPP: VJ decompression error\n");
1694 goto err;
1695 }
1696 len += 2;
1697 if (len > skb->len)
1698 skb_put(skb, len - skb->len);
1699 else if (len < skb->len)
1700 skb_trim(skb, len);
1701 proto = PPP_IP;
1702 break;
1703
1704 case PPP_VJC_UNCOMP:
1705 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1706 goto err;
1707
1708 /* Until we fix the decompressor need to make sure
1709 * data portion is linear.
1710 */
1711 if (!pskb_may_pull(skb, skb->len))
1712 goto err;
1713
1714 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1715 printk(KERN_ERR "PPP: VJ uncompressed error\n");
1716 goto err;
1717 }
1718 proto = PPP_IP;
1719 break;
1720
1721 case PPP_CCP:
1722 ppp_ccp_peek(ppp, skb, 1);
1723 break;
1724 }
1725
1726 ++ppp->dev->stats.rx_packets;
1727 ppp->dev->stats.rx_bytes += skb->len - 2;
1728
1729 npi = proto_to_npindex(proto);
1730 if (npi < 0) {
1731 /* control or unknown frame - pass it to pppd */
1732 skb_queue_tail(&ppp->file.rq, skb);
1733 /* limit queue length by dropping old frames */
1734 while (ppp->file.rq.qlen > PPP_MAX_RQLEN &&
1735 (skb = skb_dequeue(&ppp->file.rq)))
1736 kfree_skb(skb);
1737 /* wake up any process polling or blocking on read */
1738 wake_up_interruptible(&ppp->file.rwait);
1739
1740 } else {
1741 /* network protocol frame - give it to the kernel */
1742
1743 #ifdef CONFIG_PPP_FILTER
1744 /* check if the packet passes the pass and active filters */
1745 /* the filter instructions are constructed assuming
1746 a four-byte PPP header on each packet */
1747 if (ppp->pass_filter || ppp->active_filter) {
1748 if (skb_cloned(skb) &&
1749 pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
1750 goto err;
1751
1752 *skb_push(skb, 2) = 0;
1753 if (ppp->pass_filter &&
1754 sk_run_filter(skb, ppp->pass_filter,
1755 ppp->pass_len) == 0) {
1756 if (ppp->debug & 1)
1757 printk(KERN_DEBUG "PPP: inbound frame "
1758 "not passed\n");
1759 kfree_skb(skb);
1760 return;
1761 }
1762 if (!(ppp->active_filter &&
1763 sk_run_filter(skb, ppp->active_filter,
1764 ppp->active_len) == 0))
1765 ppp->last_recv = jiffies;
1766 __skb_pull(skb, 2);
1767 } else
1768 #endif /* CONFIG_PPP_FILTER */
1769 ppp->last_recv = jiffies;
1770
1771 if ((ppp->dev->flags & IFF_UP) == 0 ||
1772 ppp->npmode[npi] != NPMODE_PASS) {
1773 kfree_skb(skb);
1774 } else {
1775 /* chop off protocol */
1776 skb_pull_rcsum(skb, 2);
1777 skb->dev = ppp->dev;
1778 skb->protocol = htons(npindex_to_ethertype[npi]);
1779 skb_reset_mac_header(skb);
1780 netif_rx(skb);
1781 }
1782 }
1783 return;
1784
1785 err:
1786 kfree_skb(skb);
1787 ppp_receive_error(ppp);
1788 }
1789
1790 static struct sk_buff *
1791 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1792 {
1793 int proto = PPP_PROTO(skb);
1794 struct sk_buff *ns;
1795 int len;
1796
1797 /* Until we fix all the decompressor's need to make sure
1798 * data portion is linear.
1799 */
1800 if (!pskb_may_pull(skb, skb->len))
1801 goto err;
1802
1803 if (proto == PPP_COMP) {
1804 int obuff_size;
1805
1806 switch(ppp->rcomp->compress_proto) {
1807 case CI_MPPE:
1808 obuff_size = ppp->mru + PPP_HDRLEN + 1;
1809 break;
1810 default:
1811 obuff_size = ppp->mru + PPP_HDRLEN;
1812 break;
1813 }
1814
1815 ns = dev_alloc_skb(obuff_size);
1816 if (!ns) {
1817 printk(KERN_ERR "ppp_decompress_frame: no memory\n");
1818 goto err;
1819 }
1820 /* the decompressor still expects the A/C bytes in the hdr */
1821 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1822 skb->len + 2, ns->data, obuff_size);
1823 if (len < 0) {
1824 /* Pass the compressed frame to pppd as an
1825 error indication. */
1826 if (len == DECOMP_FATALERROR)
1827 ppp->rstate |= SC_DC_FERROR;
1828 kfree_skb(ns);
1829 goto err;
1830 }
1831
1832 kfree_skb(skb);
1833 skb = ns;
1834 skb_put(skb, len);
1835 skb_pull(skb, 2); /* pull off the A/C bytes */
1836
1837 } else {
1838 /* Uncompressed frame - pass to decompressor so it
1839 can update its dictionary if necessary. */
1840 if (ppp->rcomp->incomp)
1841 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1842 skb->len + 2);
1843 }
1844
1845 return skb;
1846
1847 err:
1848 ppp->rstate |= SC_DC_ERROR;
1849 ppp_receive_error(ppp);
1850 return skb;
1851 }
1852
1853 #ifdef CONFIG_PPP_MULTILINK
1854 /*
1855 * Receive a multilink frame.
1856 * We put it on the reconstruction queue and then pull off
1857 * as many completed frames as we can.
1858 */
1859 static void
1860 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1861 {
1862 u32 mask, seq;
1863 struct channel *ch;
1864 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1865
1866 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
1867 goto err; /* no good, throw it away */
1868
1869 /* Decode sequence number and begin/end bits */
1870 if (ppp->flags & SC_MP_SHORTSEQ) {
1871 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1872 mask = 0xfff;
1873 } else {
1874 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1875 mask = 0xffffff;
1876 }
1877 skb->BEbits = skb->data[2];
1878 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
1879
1880 /*
1881 * Do protocol ID decompression on the first fragment of each packet.
1882 */
1883 if ((skb->BEbits & B) && (skb->data[0] & 1))
1884 *skb_push(skb, 1) = 0;
1885
1886 /*
1887 * Expand sequence number to 32 bits, making it as close
1888 * as possible to ppp->minseq.
1889 */
1890 seq |= ppp->minseq & ~mask;
1891 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
1892 seq += mask + 1;
1893 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
1894 seq -= mask + 1; /* should never happen */
1895 skb->sequence = seq;
1896 pch->lastseq = seq;
1897
1898 /*
1899 * If this packet comes before the next one we were expecting,
1900 * drop it.
1901 */
1902 if (seq_before(seq, ppp->nextseq)) {
1903 kfree_skb(skb);
1904 ++ppp->dev->stats.rx_dropped;
1905 ppp_receive_error(ppp);
1906 return;
1907 }
1908
1909 /*
1910 * Reevaluate minseq, the minimum over all channels of the
1911 * last sequence number received on each channel. Because of
1912 * the increasing sequence number rule, we know that any fragment
1913 * before `minseq' which hasn't arrived is never going to arrive.
1914 * The list of channels can't change because we have the receive
1915 * side of the ppp unit locked.
1916 */
1917 list_for_each_entry(ch, &ppp->channels, clist) {
1918 if (seq_before(ch->lastseq, seq))
1919 seq = ch->lastseq;
1920 }
1921 if (seq_before(ppp->minseq, seq))
1922 ppp->minseq = seq;
1923
1924 /* Put the fragment on the reconstruction queue */
1925 ppp_mp_insert(ppp, skb);
1926
1927 /* If the queue is getting long, don't wait any longer for packets
1928 before the start of the queue. */
1929 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
1930 struct sk_buff *mskb = skb_peek(&ppp->mrq);
1931 if (seq_before(ppp->minseq, mskb->sequence))
1932 ppp->minseq = mskb->sequence;
1933 }
1934
1935 /* Pull completed packets off the queue and receive them. */
1936 while ((skb = ppp_mp_reconstruct(ppp))) {
1937 if (pskb_may_pull(skb, 2))
1938 ppp_receive_nonmp_frame(ppp, skb);
1939 else {
1940 ++ppp->dev->stats.rx_length_errors;
1941 kfree_skb(skb);
1942 ppp_receive_error(ppp);
1943 }
1944 }
1945
1946 return;
1947
1948 err:
1949 kfree_skb(skb);
1950 ppp_receive_error(ppp);
1951 }
1952
1953 /*
1954 * Insert a fragment on the MP reconstruction queue.
1955 * The queue is ordered by increasing sequence number.
1956 */
1957 static void
1958 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
1959 {
1960 struct sk_buff *p;
1961 struct sk_buff_head *list = &ppp->mrq;
1962 u32 seq = skb->sequence;
1963
1964 /* N.B. we don't need to lock the list lock because we have the
1965 ppp unit receive-side lock. */
1966 skb_queue_walk(list, p) {
1967 if (seq_before(seq, p->sequence))
1968 break;
1969 }
1970 __skb_queue_before(list, p, skb);
1971 }
1972
1973 /*
1974 * Reconstruct a packet from the MP fragment queue.
1975 * We go through increasing sequence numbers until we find a
1976 * complete packet, or we get to the sequence number for a fragment
1977 * which hasn't arrived but might still do so.
1978 */
1979 static struct sk_buff *
1980 ppp_mp_reconstruct(struct ppp *ppp)
1981 {
1982 u32 seq = ppp->nextseq;
1983 u32 minseq = ppp->minseq;
1984 struct sk_buff_head *list = &ppp->mrq;
1985 struct sk_buff *p, *next;
1986 struct sk_buff *head, *tail;
1987 struct sk_buff *skb = NULL;
1988 int lost = 0, len = 0;
1989
1990 if (ppp->mrru == 0) /* do nothing until mrru is set */
1991 return NULL;
1992 head = list->next;
1993 tail = NULL;
1994 for (p = head; p != (struct sk_buff *) list; p = next) {
1995 next = p->next;
1996 if (seq_before(p->sequence, seq)) {
1997 /* this can't happen, anyway ignore the skb */
1998 printk(KERN_ERR "ppp_mp_reconstruct bad seq %u < %u\n",
1999 p->sequence, seq);
2000 head = next;
2001 continue;
2002 }
2003 if (p->sequence != seq) {
2004 /* Fragment `seq' is missing. If it is after
2005 minseq, it might arrive later, so stop here. */
2006 if (seq_after(seq, minseq))
2007 break;
2008 /* Fragment `seq' is lost, keep going. */
2009 lost = 1;
2010 seq = seq_before(minseq, p->sequence)?
2011 minseq + 1: p->sequence;
2012 next = p;
2013 continue;
2014 }
2015
2016 /*
2017 * At this point we know that all the fragments from
2018 * ppp->nextseq to seq are either present or lost.
2019 * Also, there are no complete packets in the queue
2020 * that have no missing fragments and end before this
2021 * fragment.
2022 */
2023
2024 /* B bit set indicates this fragment starts a packet */
2025 if (p->BEbits & B) {
2026 head = p;
2027 lost = 0;
2028 len = 0;
2029 }
2030
2031 len += p->len;
2032
2033 /* Got a complete packet yet? */
2034 if (lost == 0 && (p->BEbits & E) && (head->BEbits & B)) {
2035 if (len > ppp->mrru + 2) {
2036 ++ppp->dev->stats.rx_length_errors;
2037 printk(KERN_DEBUG "PPP: reconstructed packet"
2038 " is too long (%d)\n", len);
2039 } else if (p == head) {
2040 /* fragment is complete packet - reuse skb */
2041 tail = p;
2042 skb = skb_get(p);
2043 break;
2044 } else if ((skb = dev_alloc_skb(len)) == NULL) {
2045 ++ppp->dev->stats.rx_missed_errors;
2046 printk(KERN_DEBUG "PPP: no memory for "
2047 "reconstructed packet");
2048 } else {
2049 tail = p;
2050 break;
2051 }
2052 ppp->nextseq = seq + 1;
2053 }
2054
2055 /*
2056 * If this is the ending fragment of a packet,
2057 * and we haven't found a complete valid packet yet,
2058 * we can discard up to and including this fragment.
2059 */
2060 if (p->BEbits & E)
2061 head = next;
2062
2063 ++seq;
2064 }
2065
2066 /* If we have a complete packet, copy it all into one skb. */
2067 if (tail != NULL) {
2068 /* If we have discarded any fragments,
2069 signal a receive error. */
2070 if (head->sequence != ppp->nextseq) {
2071 if (ppp->debug & 1)
2072 printk(KERN_DEBUG " missed pkts %u..%u\n",
2073 ppp->nextseq, head->sequence-1);
2074 ++ppp->dev->stats.rx_dropped;
2075 ppp_receive_error(ppp);
2076 }
2077
2078 if (head != tail)
2079 /* copy to a single skb */
2080 for (p = head; p != tail->next; p = p->next)
2081 skb_copy_bits(p, 0, skb_put(skb, p->len), p->len);
2082 ppp->nextseq = tail->sequence + 1;
2083 head = tail->next;
2084 }
2085
2086 /* Discard all the skbuffs that we have copied the data out of
2087 or that we can't use. */
2088 while ((p = list->next) != head) {
2089 __skb_unlink(p, list);
2090 kfree_skb(p);
2091 }
2092
2093 return skb;
2094 }
2095 #endif /* CONFIG_PPP_MULTILINK */
2096
2097 /*
2098 * Channel interface.
2099 */
2100
2101 /* Create a new, unattached ppp channel. */
2102 int ppp_register_channel(struct ppp_channel *chan)
2103 {
2104 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2105 }
2106
2107 /* Create a new, unattached ppp channel for specified net. */
2108 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
2109 {
2110 struct channel *pch;
2111 struct ppp_net *pn;
2112
2113 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2114 if (!pch)
2115 return -ENOMEM;
2116
2117 pn = ppp_pernet(net);
2118
2119 pch->ppp = NULL;
2120 pch->chan = chan;
2121 pch->chan_net = net;
2122 chan->ppp = pch;
2123 init_ppp_file(&pch->file, CHANNEL);
2124 pch->file.hdrlen = chan->hdrlen;
2125 #ifdef CONFIG_PPP_MULTILINK
2126 pch->lastseq = -1;
2127 #endif /* CONFIG_PPP_MULTILINK */
2128 init_rwsem(&pch->chan_sem);
2129 spin_lock_init(&pch->downl);
2130 rwlock_init(&pch->upl);
2131
2132 spin_lock_bh(&pn->all_channels_lock);
2133 pch->file.index = ++pn->last_channel_index;
2134 list_add(&pch->list, &pn->new_channels);
2135 atomic_inc(&channel_count);
2136 spin_unlock_bh(&pn->all_channels_lock);
2137
2138 return 0;
2139 }
2140
2141 /*
2142 * Return the index of a channel.
2143 */
2144 int ppp_channel_index(struct ppp_channel *chan)
2145 {
2146 struct channel *pch = chan->ppp;
2147
2148 if (pch)
2149 return pch->file.index;
2150 return -1;
2151 }
2152
2153 /*
2154 * Return the PPP unit number to which a channel is connected.
2155 */
2156 int ppp_unit_number(struct ppp_channel *chan)
2157 {
2158 struct channel *pch = chan->ppp;
2159 int unit = -1;
2160
2161 if (pch) {
2162 read_lock_bh(&pch->upl);
2163 if (pch->ppp)
2164 unit = pch->ppp->file.index;
2165 read_unlock_bh(&pch->upl);
2166 }
2167 return unit;
2168 }
2169
2170 /*
2171 * Return the PPP device interface name of a channel.
2172 */
2173 char *ppp_dev_name(struct ppp_channel *chan)
2174 {
2175 struct channel *pch = chan->ppp;
2176 char *name = NULL;
2177
2178 if (pch) {
2179 read_lock_bh(&pch->upl);
2180 if (pch->ppp && pch->ppp->dev)
2181 name = pch->ppp->dev->name;
2182 read_unlock_bh(&pch->upl);
2183 }
2184 return name;
2185 }
2186
2187
2188 /*
2189 * Disconnect a channel from the generic layer.
2190 * This must be called in process context.
2191 */
2192 void
2193 ppp_unregister_channel(struct ppp_channel *chan)
2194 {
2195 struct channel *pch = chan->ppp;
2196 struct ppp_net *pn;
2197
2198 if (!pch)
2199 return; /* should never happen */
2200
2201 chan->ppp = NULL;
2202
2203 /*
2204 * This ensures that we have returned from any calls into the
2205 * the channel's start_xmit or ioctl routine before we proceed.
2206 */
2207 down_write(&pch->chan_sem);
2208 spin_lock_bh(&pch->downl);
2209 pch->chan = NULL;
2210 spin_unlock_bh(&pch->downl);
2211 up_write(&pch->chan_sem);
2212 ppp_disconnect_channel(pch);
2213
2214 pn = ppp_pernet(pch->chan_net);
2215 spin_lock_bh(&pn->all_channels_lock);
2216 list_del(&pch->list);
2217 spin_unlock_bh(&pn->all_channels_lock);
2218
2219 pch->file.dead = 1;
2220 wake_up_interruptible(&pch->file.rwait);
2221 if (atomic_dec_and_test(&pch->file.refcnt))
2222 ppp_destroy_channel(pch);
2223 }
2224
2225 /*
2226 * Callback from a channel when it can accept more to transmit.
2227 * This should be called at BH/softirq level, not interrupt level.
2228 */
2229 void
2230 ppp_output_wakeup(struct ppp_channel *chan)
2231 {
2232 struct channel *pch = chan->ppp;
2233
2234 if (!pch)
2235 return;
2236 ppp_channel_push(pch);
2237 }
2238
2239 /*
2240 * Compression control.
2241 */
2242
2243 /* Process the PPPIOCSCOMPRESS ioctl. */
2244 static int
2245 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2246 {
2247 int err;
2248 struct compressor *cp, *ocomp;
2249 struct ppp_option_data data;
2250 void *state, *ostate;
2251 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2252
2253 err = -EFAULT;
2254 if (copy_from_user(&data, (void __user *) arg, sizeof(data)) ||
2255 (data.length <= CCP_MAX_OPTION_LENGTH &&
2256 copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2257 goto out;
2258 err = -EINVAL;
2259 if (data.length > CCP_MAX_OPTION_LENGTH ||
2260 ccp_option[1] < 2 || ccp_option[1] > data.length)
2261 goto out;
2262
2263 cp = try_then_request_module(
2264 find_compressor(ccp_option[0]),
2265 "ppp-compress-%d", ccp_option[0]);
2266 if (!cp)
2267 goto out;
2268
2269 err = -ENOBUFS;
2270 if (data.transmit) {
2271 state = cp->comp_alloc(ccp_option, data.length);
2272 if (state) {
2273 ppp_xmit_lock(ppp);
2274 ppp->xstate &= ~SC_COMP_RUN;
2275 ocomp = ppp->xcomp;
2276 ostate = ppp->xc_state;
2277 ppp->xcomp = cp;
2278 ppp->xc_state = state;
2279 ppp_xmit_unlock(ppp);
2280 if (ostate) {
2281 ocomp->comp_free(ostate);
2282 module_put(ocomp->owner);
2283 }
2284 err = 0;
2285 } else
2286 module_put(cp->owner);
2287
2288 } else {
2289 state = cp->decomp_alloc(ccp_option, data.length);
2290 if (state) {
2291 ppp_recv_lock(ppp);
2292 ppp->rstate &= ~SC_DECOMP_RUN;
2293 ocomp = ppp->rcomp;
2294 ostate = ppp->rc_state;
2295 ppp->rcomp = cp;
2296 ppp->rc_state = state;
2297 ppp_recv_unlock(ppp);
2298 if (ostate) {
2299 ocomp->decomp_free(ostate);
2300 module_put(ocomp->owner);
2301 }
2302 err = 0;
2303 } else
2304 module_put(cp->owner);
2305 }
2306
2307 out:
2308 return err;
2309 }
2310
2311 /*
2312 * Look at a CCP packet and update our state accordingly.
2313 * We assume the caller has the xmit or recv path locked.
2314 */
2315 static void
2316 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2317 {
2318 unsigned char *dp;
2319 int len;
2320
2321 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2322 return; /* no header */
2323 dp = skb->data + 2;
2324
2325 switch (CCP_CODE(dp)) {
2326 case CCP_CONFREQ:
2327
2328 /* A ConfReq starts negotiation of compression
2329 * in one direction of transmission,
2330 * and hence brings it down...but which way?
2331 *
2332 * Remember:
2333 * A ConfReq indicates what the sender would like to receive
2334 */
2335 if(inbound)
2336 /* He is proposing what I should send */
2337 ppp->xstate &= ~SC_COMP_RUN;
2338 else
2339 /* I am proposing to what he should send */
2340 ppp->rstate &= ~SC_DECOMP_RUN;
2341
2342 break;
2343
2344 case CCP_TERMREQ:
2345 case CCP_TERMACK:
2346 /*
2347 * CCP is going down, both directions of transmission
2348 */
2349 ppp->rstate &= ~SC_DECOMP_RUN;
2350 ppp->xstate &= ~SC_COMP_RUN;
2351 break;
2352
2353 case CCP_CONFACK:
2354 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2355 break;
2356 len = CCP_LENGTH(dp);
2357 if (!pskb_may_pull(skb, len + 2))
2358 return; /* too short */
2359 dp += CCP_HDRLEN;
2360 len -= CCP_HDRLEN;
2361 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2362 break;
2363 if (inbound) {
2364 /* we will start receiving compressed packets */
2365 if (!ppp->rc_state)
2366 break;
2367 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2368 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2369 ppp->rstate |= SC_DECOMP_RUN;
2370 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2371 }
2372 } else {
2373 /* we will soon start sending compressed packets */
2374 if (!ppp->xc_state)
2375 break;
2376 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2377 ppp->file.index, 0, ppp->debug))
2378 ppp->xstate |= SC_COMP_RUN;
2379 }
2380 break;
2381
2382 case CCP_RESETACK:
2383 /* reset the [de]compressor */
2384 if ((ppp->flags & SC_CCP_UP) == 0)
2385 break;
2386 if (inbound) {
2387 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2388 ppp->rcomp->decomp_reset(ppp->rc_state);
2389 ppp->rstate &= ~SC_DC_ERROR;
2390 }
2391 } else {
2392 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2393 ppp->xcomp->comp_reset(ppp->xc_state);
2394 }
2395 break;
2396 }
2397 }
2398
2399 /* Free up compression resources. */
2400 static void
2401 ppp_ccp_closed(struct ppp *ppp)
2402 {
2403 void *xstate, *rstate;
2404 struct compressor *xcomp, *rcomp;
2405
2406 ppp_lock(ppp);
2407 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2408 ppp->xstate = 0;
2409 xcomp = ppp->xcomp;
2410 xstate = ppp->xc_state;
2411 ppp->xc_state = NULL;
2412 ppp->rstate = 0;
2413 rcomp = ppp->rcomp;
2414 rstate = ppp->rc_state;
2415 ppp->rc_state = NULL;
2416 ppp_unlock(ppp);
2417
2418 if (xstate) {
2419 xcomp->comp_free(xstate);
2420 module_put(xcomp->owner);
2421 }
2422 if (rstate) {
2423 rcomp->decomp_free(rstate);
2424 module_put(rcomp->owner);
2425 }
2426 }
2427
2428 /* List of compressors. */
2429 static LIST_HEAD(compressor_list);
2430 static DEFINE_SPINLOCK(compressor_list_lock);
2431
2432 struct compressor_entry {
2433 struct list_head list;
2434 struct compressor *comp;
2435 };
2436
2437 static struct compressor_entry *
2438 find_comp_entry(int proto)
2439 {
2440 struct compressor_entry *ce;
2441
2442 list_for_each_entry(ce, &compressor_list, list) {
2443 if (ce->comp->compress_proto == proto)
2444 return ce;
2445 }
2446 return NULL;
2447 }
2448
2449 /* Register a compressor */
2450 int
2451 ppp_register_compressor(struct compressor *cp)
2452 {
2453 struct compressor_entry *ce;
2454 int ret;
2455 spin_lock(&compressor_list_lock);
2456 ret = -EEXIST;
2457 if (find_comp_entry(cp->compress_proto))
2458 goto out;
2459 ret = -ENOMEM;
2460 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2461 if (!ce)
2462 goto out;
2463 ret = 0;
2464 ce->comp = cp;
2465 list_add(&ce->list, &compressor_list);
2466 out:
2467 spin_unlock(&compressor_list_lock);
2468 return ret;
2469 }
2470
2471 /* Unregister a compressor */
2472 void
2473 ppp_unregister_compressor(struct compressor *cp)
2474 {
2475 struct compressor_entry *ce;
2476
2477 spin_lock(&compressor_list_lock);
2478 ce = find_comp_entry(cp->compress_proto);
2479 if (ce && ce->comp == cp) {
2480 list_del(&ce->list);
2481 kfree(ce);
2482 }
2483 spin_unlock(&compressor_list_lock);
2484 }
2485
2486 /* Find a compressor. */
2487 static struct compressor *
2488 find_compressor(int type)
2489 {
2490 struct compressor_entry *ce;
2491 struct compressor *cp = NULL;
2492
2493 spin_lock(&compressor_list_lock);
2494 ce = find_comp_entry(type);
2495 if (ce) {
2496 cp = ce->comp;
2497 if (!try_module_get(cp->owner))
2498 cp = NULL;
2499 }
2500 spin_unlock(&compressor_list_lock);
2501 return cp;
2502 }
2503
2504 /*
2505 * Miscelleneous stuff.
2506 */
2507
2508 static void
2509 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2510 {
2511 struct slcompress *vj = ppp->vj;
2512
2513 memset(st, 0, sizeof(*st));
2514 st->p.ppp_ipackets = ppp->dev->stats.rx_packets;
2515 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2516 st->p.ppp_ibytes = ppp->dev->stats.rx_bytes;
2517 st->p.ppp_opackets = ppp->dev->stats.tx_packets;
2518 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2519 st->p.ppp_obytes = ppp->dev->stats.tx_bytes;
2520 if (!vj)
2521 return;
2522 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2523 st->vj.vjs_compressed = vj->sls_o_compressed;
2524 st->vj.vjs_searches = vj->sls_o_searches;
2525 st->vj.vjs_misses = vj->sls_o_misses;
2526 st->vj.vjs_errorin = vj->sls_i_error;
2527 st->vj.vjs_tossed = vj->sls_i_tossed;
2528 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2529 st->vj.vjs_compressedin = vj->sls_i_compressed;
2530 }
2531
2532 /*
2533 * Stuff for handling the lists of ppp units and channels
2534 * and for initialization.
2535 */
2536
2537 /*
2538 * Create a new ppp interface unit. Fails if it can't allocate memory
2539 * or if there is already a unit with the requested number.
2540 * unit == -1 means allocate a new number.
2541 */
2542 static struct ppp *
2543 ppp_create_interface(struct net *net, int unit, int *retp)
2544 {
2545 struct ppp *ppp;
2546 struct ppp_net *pn;
2547 struct net_device *dev = NULL;
2548 int ret = -ENOMEM;
2549 int i;
2550
2551 dev = alloc_netdev(sizeof(struct ppp), "", ppp_setup);
2552 if (!dev)
2553 goto out1;
2554
2555 pn = ppp_pernet(net);
2556
2557 ppp = netdev_priv(dev);
2558 ppp->dev = dev;
2559 ppp->mru = PPP_MRU;
2560 init_ppp_file(&ppp->file, INTERFACE);
2561 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2562 for (i = 0; i < NUM_NP; ++i)
2563 ppp->npmode[i] = NPMODE_PASS;
2564 INIT_LIST_HEAD(&ppp->channels);
2565 spin_lock_init(&ppp->rlock);
2566 spin_lock_init(&ppp->wlock);
2567 #ifdef CONFIG_PPP_MULTILINK
2568 ppp->minseq = -1;
2569 skb_queue_head_init(&ppp->mrq);
2570 #endif /* CONFIG_PPP_MULTILINK */
2571
2572 /*
2573 * drum roll: don't forget to set
2574 * the net device is belong to
2575 */
2576 dev_net_set(dev, net);
2577
2578 ret = -EEXIST;
2579 mutex_lock(&pn->all_ppp_mutex);
2580
2581 if (unit < 0) {
2582 unit = unit_get(&pn->units_idr, ppp);
2583 if (unit < 0) {
2584 *retp = unit;
2585 goto out2;
2586 }
2587 } else {
2588 if (unit_find(&pn->units_idr, unit))
2589 goto out2; /* unit already exists */
2590 /*
2591 * if caller need a specified unit number
2592 * lets try to satisfy him, otherwise --
2593 * he should better ask us for new unit number
2594 *
2595 * NOTE: yes I know that returning EEXIST it's not
2596 * fair but at least pppd will ask us to allocate
2597 * new unit in this case so user is happy :)
2598 */
2599 unit = unit_set(&pn->units_idr, ppp, unit);
2600 if (unit < 0)
2601 goto out2;
2602 }
2603
2604 /* Initialize the new ppp unit */
2605 ppp->file.index = unit;
2606 sprintf(dev->name, "ppp%d", unit);
2607
2608 ret = register_netdev(dev);
2609 if (ret != 0) {
2610 unit_put(&pn->units_idr, unit);
2611 printk(KERN_ERR "PPP: couldn't register device %s (%d)\n",
2612 dev->name, ret);
2613 goto out2;
2614 }
2615
2616 ppp->ppp_net = net;
2617
2618 atomic_inc(&ppp_unit_count);
2619 mutex_unlock(&pn->all_ppp_mutex);
2620
2621 *retp = 0;
2622 return ppp;
2623
2624 out2:
2625 mutex_unlock(&pn->all_ppp_mutex);
2626 free_netdev(dev);
2627 out1:
2628 *retp = ret;
2629 return NULL;
2630 }
2631
2632 /*
2633 * Initialize a ppp_file structure.
2634 */
2635 static void
2636 init_ppp_file(struct ppp_file *pf, int kind)
2637 {
2638 pf->kind = kind;
2639 skb_queue_head_init(&pf->xq);
2640 skb_queue_head_init(&pf->rq);
2641 atomic_set(&pf->refcnt, 1);
2642 init_waitqueue_head(&pf->rwait);
2643 }
2644
2645 /*
2646 * Take down a ppp interface unit - called when the owning file
2647 * (the one that created the unit) is closed or detached.
2648 */
2649 static void ppp_shutdown_interface(struct ppp *ppp)
2650 {
2651 struct ppp_net *pn;
2652
2653 pn = ppp_pernet(ppp->ppp_net);
2654 mutex_lock(&pn->all_ppp_mutex);
2655
2656 /* This will call dev_close() for us. */
2657 ppp_lock(ppp);
2658 if (!ppp->closing) {
2659 ppp->closing = 1;
2660 ppp_unlock(ppp);
2661 unregister_netdev(ppp->dev);
2662 } else
2663 ppp_unlock(ppp);
2664
2665 unit_put(&pn->units_idr, ppp->file.index);
2666 ppp->file.dead = 1;
2667 ppp->owner = NULL;
2668 wake_up_interruptible(&ppp->file.rwait);
2669
2670 mutex_unlock(&pn->all_ppp_mutex);
2671 }
2672
2673 /*
2674 * Free the memory used by a ppp unit. This is only called once
2675 * there are no channels connected to the unit and no file structs
2676 * that reference the unit.
2677 */
2678 static void ppp_destroy_interface(struct ppp *ppp)
2679 {
2680 atomic_dec(&ppp_unit_count);
2681
2682 if (!ppp->file.dead || ppp->n_channels) {
2683 /* "can't happen" */
2684 printk(KERN_ERR "ppp: destroying ppp struct %p but dead=%d "
2685 "n_channels=%d !\n", ppp, ppp->file.dead,
2686 ppp->n_channels);
2687 return;
2688 }
2689
2690 ppp_ccp_closed(ppp);
2691 if (ppp->vj) {
2692 slhc_free(ppp->vj);
2693 ppp->vj = NULL;
2694 }
2695 skb_queue_purge(&ppp->file.xq);
2696 skb_queue_purge(&ppp->file.rq);
2697 #ifdef CONFIG_PPP_MULTILINK
2698 skb_queue_purge(&ppp->mrq);
2699 #endif /* CONFIG_PPP_MULTILINK */
2700 #ifdef CONFIG_PPP_FILTER
2701 kfree(ppp->pass_filter);
2702 ppp->pass_filter = NULL;
2703 kfree(ppp->active_filter);
2704 ppp->active_filter = NULL;
2705 #endif /* CONFIG_PPP_FILTER */
2706
2707 kfree_skb(ppp->xmit_pending);
2708
2709 free_netdev(ppp->dev);
2710 }
2711
2712 /*
2713 * Locate an existing ppp unit.
2714 * The caller should have locked the all_ppp_mutex.
2715 */
2716 static struct ppp *
2717 ppp_find_unit(struct ppp_net *pn, int unit)
2718 {
2719 return unit_find(&pn->units_idr, unit);
2720 }
2721
2722 /*
2723 * Locate an existing ppp channel.
2724 * The caller should have locked the all_channels_lock.
2725 * First we look in the new_channels list, then in the
2726 * all_channels list. If found in the new_channels list,
2727 * we move it to the all_channels list. This is for speed
2728 * when we have a lot of channels in use.
2729 */
2730 static struct channel *
2731 ppp_find_channel(struct ppp_net *pn, int unit)
2732 {
2733 struct channel *pch;
2734
2735 list_for_each_entry(pch, &pn->new_channels, list) {
2736 if (pch->file.index == unit) {
2737 list_move(&pch->list, &pn->all_channels);
2738 return pch;
2739 }
2740 }
2741
2742 list_for_each_entry(pch, &pn->all_channels, list) {
2743 if (pch->file.index == unit)
2744 return pch;
2745 }
2746
2747 return NULL;
2748 }
2749
2750 /*
2751 * Connect a PPP channel to a PPP interface unit.
2752 */
2753 static int
2754 ppp_connect_channel(struct channel *pch, int unit)
2755 {
2756 struct ppp *ppp;
2757 struct ppp_net *pn;
2758 int ret = -ENXIO;
2759 int hdrlen;
2760
2761 pn = ppp_pernet(pch->chan_net);
2762
2763 mutex_lock(&pn->all_ppp_mutex);
2764 ppp = ppp_find_unit(pn, unit);
2765 if (!ppp)
2766 goto out;
2767 write_lock_bh(&pch->upl);
2768 ret = -EINVAL;
2769 if (pch->ppp)
2770 goto outl;
2771
2772 ppp_lock(ppp);
2773 if (pch->file.hdrlen > ppp->file.hdrlen)
2774 ppp->file.hdrlen = pch->file.hdrlen;
2775 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2776 if (hdrlen > ppp->dev->hard_header_len)
2777 ppp->dev->hard_header_len = hdrlen;
2778 list_add_tail(&pch->clist, &ppp->channels);
2779 ++ppp->n_channels;
2780 pch->ppp = ppp;
2781 atomic_inc(&ppp->file.refcnt);
2782 ppp_unlock(ppp);
2783 ret = 0;
2784
2785 outl:
2786 write_unlock_bh(&pch->upl);
2787 out:
2788 mutex_unlock(&pn->all_ppp_mutex);
2789 return ret;
2790 }
2791
2792 /*
2793 * Disconnect a channel from its ppp unit.
2794 */
2795 static int
2796 ppp_disconnect_channel(struct channel *pch)
2797 {
2798 struct ppp *ppp;
2799 int err = -EINVAL;
2800
2801 write_lock_bh(&pch->upl);
2802 ppp = pch->ppp;
2803 pch->ppp = NULL;
2804 write_unlock_bh(&pch->upl);
2805 if (ppp) {
2806 /* remove it from the ppp unit's list */
2807 ppp_lock(ppp);
2808 list_del(&pch->clist);
2809 if (--ppp->n_channels == 0)
2810 wake_up_interruptible(&ppp->file.rwait);
2811 ppp_unlock(ppp);
2812 if (atomic_dec_and_test(&ppp->file.refcnt))
2813 ppp_destroy_interface(ppp);
2814 err = 0;
2815 }
2816 return err;
2817 }
2818
2819 /*
2820 * Free up the resources used by a ppp channel.
2821 */
2822 static void ppp_destroy_channel(struct channel *pch)
2823 {
2824 atomic_dec(&channel_count);
2825
2826 if (!pch->file.dead) {
2827 /* "can't happen" */
2828 printk(KERN_ERR "ppp: destroying undead channel %p !\n",
2829 pch);
2830 return;
2831 }
2832 skb_queue_purge(&pch->file.xq);
2833 skb_queue_purge(&pch->file.rq);
2834 kfree(pch);
2835 }
2836
2837 static void __exit ppp_cleanup(void)
2838 {
2839 /* should never happen */
2840 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2841 printk(KERN_ERR "PPP: removing module but units remain!\n");
2842 unregister_chrdev(PPP_MAJOR, "ppp");
2843 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
2844 class_destroy(ppp_class);
2845 unregister_pernet_device(&ppp_net_ops);
2846 }
2847
2848 /*
2849 * Units handling. Caller must protect concurrent access
2850 * by holding all_ppp_mutex
2851 */
2852
2853 /* associate pointer with specified number */
2854 static int unit_set(struct idr *p, void *ptr, int n)
2855 {
2856 int unit, err;
2857
2858 again:
2859 if (!idr_pre_get(p, GFP_KERNEL)) {
2860 printk(KERN_ERR "PPP: No free memory for idr\n");
2861 return -ENOMEM;
2862 }
2863
2864 err = idr_get_new_above(p, ptr, n, &unit);
2865 if (err == -EAGAIN)
2866 goto again;
2867
2868 if (unit != n) {
2869 idr_remove(p, unit);
2870 return -EINVAL;
2871 }
2872
2873 return unit;
2874 }
2875
2876 /* get new free unit number and associate pointer with it */
2877 static int unit_get(struct idr *p, void *ptr)
2878 {
2879 int unit, err;
2880
2881 again:
2882 if (!idr_pre_get(p, GFP_KERNEL)) {
2883 printk(KERN_ERR "PPP: No free memory for idr\n");
2884 return -ENOMEM;
2885 }
2886
2887 err = idr_get_new_above(p, ptr, 0, &unit);
2888 if (err == -EAGAIN)
2889 goto again;
2890
2891 return unit;
2892 }
2893
2894 /* put unit number back to a pool */
2895 static void unit_put(struct idr *p, int n)
2896 {
2897 idr_remove(p, n);
2898 }
2899
2900 /* get pointer associated with the number */
2901 static void *unit_find(struct idr *p, int n)
2902 {
2903 return idr_find(p, n);
2904 }
2905
2906 /* Module/initialization stuff */
2907
2908 module_init(ppp_init);
2909 module_exit(ppp_cleanup);
2910
2911 EXPORT_SYMBOL(ppp_register_net_channel);
2912 EXPORT_SYMBOL(ppp_register_channel);
2913 EXPORT_SYMBOL(ppp_unregister_channel);
2914 EXPORT_SYMBOL(ppp_channel_index);
2915 EXPORT_SYMBOL(ppp_unit_number);
2916 EXPORT_SYMBOL(ppp_dev_name);
2917 EXPORT_SYMBOL(ppp_input);
2918 EXPORT_SYMBOL(ppp_input_error);
2919 EXPORT_SYMBOL(ppp_output_wakeup);
2920 EXPORT_SYMBOL(ppp_register_compressor);
2921 EXPORT_SYMBOL(ppp_unregister_compressor);
2922 MODULE_LICENSE("GPL");
2923 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
2924 MODULE_ALIAS("devname:ppp");
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree