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nfsd: make V4ROOT exports read-only
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / net / ppp_generic.c
blob965adb6174c33a4b65223fabd7372f3da4781b35
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 <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 #define MIN_FRAG_SIZE 64
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;
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
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 if (copy_to_user(buf, skb->data, skb->len))
451 goto outf;
452 ret = skb->len;
453
454 outf:
455 kfree_skb(skb);
456 out:
457 return ret;
458 }
459
460 static ssize_t ppp_write(struct file *file, const char __user *buf,
461 size_t count, loff_t *ppos)
462 {
463 struct ppp_file *pf = file->private_data;
464 struct sk_buff *skb;
465 ssize_t ret;
466
467 if (!pf)
468 return -ENXIO;
469 ret = -ENOMEM;
470 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
471 if (!skb)
472 goto out;
473 skb_reserve(skb, pf->hdrlen);
474 ret = -EFAULT;
475 if (copy_from_user(skb_put(skb, count), buf, count)) {
476 kfree_skb(skb);
477 goto out;
478 }
479
480 skb_queue_tail(&pf->xq, skb);
481
482 switch (pf->kind) {
483 case INTERFACE:
484 ppp_xmit_process(PF_TO_PPP(pf));
485 break;
486 case CHANNEL:
487 ppp_channel_push(PF_TO_CHANNEL(pf));
488 break;
489 }
490
491 ret = count;
492
493 out:
494 return ret;
495 }
496
497 /* No kernel lock - fine */
498 static unsigned int ppp_poll(struct file *file, poll_table *wait)
499 {
500 struct ppp_file *pf = file->private_data;
501 unsigned int mask;
502
503 if (!pf)
504 return 0;
505 poll_wait(file, &pf->rwait, wait);
506 mask = POLLOUT | POLLWRNORM;
507 if (skb_peek(&pf->rq))
508 mask |= POLLIN | POLLRDNORM;
509 if (pf->dead)
510 mask |= POLLHUP;
511 else if (pf->kind == INTERFACE) {
512 /* see comment in ppp_read */
513 struct ppp *ppp = PF_TO_PPP(pf);
514 if (ppp->n_channels == 0
515 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
516 mask |= POLLIN | POLLRDNORM;
517 }
518
519 return mask;
520 }
521
522 #ifdef CONFIG_PPP_FILTER
523 static int get_filter(void __user *arg, struct sock_filter **p)
524 {
525 struct sock_fprog uprog;
526 struct sock_filter *code = NULL;
527 int len, err;
528
529 if (copy_from_user(&uprog, arg, sizeof(uprog)))
530 return -EFAULT;
531
532 if (!uprog.len) {
533 *p = NULL;
534 return 0;
535 }
536
537 len = uprog.len * sizeof(struct sock_filter);
538 code = kmalloc(len, GFP_KERNEL);
539 if (code == NULL)
540 return -ENOMEM;
541
542 if (copy_from_user(code, uprog.filter, len)) {
543 kfree(code);
544 return -EFAULT;
545 }
546
547 err = sk_chk_filter(code, uprog.len);
548 if (err) {
549 kfree(code);
550 return err;
551 }
552
553 *p = code;
554 return uprog.len;
555 }
556 #endif /* CONFIG_PPP_FILTER */
557
558 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
559 {
560 struct ppp_file *pf = file->private_data;
561 struct ppp *ppp;
562 int err = -EFAULT, val, val2, i;
563 struct ppp_idle idle;
564 struct npioctl npi;
565 int unit, cflags;
566 struct slcompress *vj;
567 void __user *argp = (void __user *)arg;
568 int __user *p = argp;
569
570 if (!pf)
571 return ppp_unattached_ioctl(current->nsproxy->net_ns,
572 pf, file, cmd, arg);
573
574 if (cmd == PPPIOCDETACH) {
575 /*
576 * We have to be careful here... if the file descriptor
577 * has been dup'd, we could have another process in the
578 * middle of a poll using the same file *, so we had
579 * better not free the interface data structures -
580 * instead we fail the ioctl. Even in this case, we
581 * shut down the interface if we are the owner of it.
582 * Actually, we should get rid of PPPIOCDETACH, userland
583 * (i.e. pppd) could achieve the same effect by closing
584 * this fd and reopening /dev/ppp.
585 */
586 err = -EINVAL;
587 lock_kernel();
588 if (pf->kind == INTERFACE) {
589 ppp = PF_TO_PPP(pf);
590 if (file == ppp->owner)
591 ppp_shutdown_interface(ppp);
592 }
593 if (atomic_long_read(&file->f_count) <= 2) {
594 ppp_release(NULL, file);
595 err = 0;
596 } else
597 printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%ld\n",
598 atomic_long_read(&file->f_count));
599 unlock_kernel();
600 return err;
601 }
602
603 if (pf->kind == CHANNEL) {
604 struct channel *pch;
605 struct ppp_channel *chan;
606
607 lock_kernel();
608 pch = PF_TO_CHANNEL(pf);
609
610 switch (cmd) {
611 case PPPIOCCONNECT:
612 if (get_user(unit, p))
613 break;
614 err = ppp_connect_channel(pch, unit);
615 break;
616
617 case PPPIOCDISCONN:
618 err = ppp_disconnect_channel(pch);
619 break;
620
621 default:
622 down_read(&pch->chan_sem);
623 chan = pch->chan;
624 err = -ENOTTY;
625 if (chan && chan->ops->ioctl)
626 err = chan->ops->ioctl(chan, cmd, arg);
627 up_read(&pch->chan_sem);
628 }
629 unlock_kernel();
630 return err;
631 }
632
633 if (pf->kind != INTERFACE) {
634 /* can't happen */
635 printk(KERN_ERR "PPP: not interface or channel??\n");
636 return -EINVAL;
637 }
638
639 lock_kernel();
640 ppp = PF_TO_PPP(pf);
641 switch (cmd) {
642 case PPPIOCSMRU:
643 if (get_user(val, p))
644 break;
645 ppp->mru = val;
646 err = 0;
647 break;
648
649 case PPPIOCSFLAGS:
650 if (get_user(val, p))
651 break;
652 ppp_lock(ppp);
653 cflags = ppp->flags & ~val;
654 ppp->flags = val & SC_FLAG_BITS;
655 ppp_unlock(ppp);
656 if (cflags & SC_CCP_OPEN)
657 ppp_ccp_closed(ppp);
658 err = 0;
659 break;
660
661 case PPPIOCGFLAGS:
662 val = ppp->flags | ppp->xstate | ppp->rstate;
663 if (put_user(val, p))
664 break;
665 err = 0;
666 break;
667
668 case PPPIOCSCOMPRESS:
669 err = ppp_set_compress(ppp, arg);
670 break;
671
672 case PPPIOCGUNIT:
673 if (put_user(ppp->file.index, p))
674 break;
675 err = 0;
676 break;
677
678 case PPPIOCSDEBUG:
679 if (get_user(val, p))
680 break;
681 ppp->debug = val;
682 err = 0;
683 break;
684
685 case PPPIOCGDEBUG:
686 if (put_user(ppp->debug, p))
687 break;
688 err = 0;
689 break;
690
691 case PPPIOCGIDLE:
692 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
693 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
694 if (copy_to_user(argp, &idle, sizeof(idle)))
695 break;
696 err = 0;
697 break;
698
699 case PPPIOCSMAXCID:
700 if (get_user(val, p))
701 break;
702 val2 = 15;
703 if ((val >> 16) != 0) {
704 val2 = val >> 16;
705 val &= 0xffff;
706 }
707 vj = slhc_init(val2+1, val+1);
708 if (!vj) {
709 printk(KERN_ERR "PPP: no memory (VJ compressor)\n");
710 err = -ENOMEM;
711 break;
712 }
713 ppp_lock(ppp);
714 if (ppp->vj)
715 slhc_free(ppp->vj);
716 ppp->vj = vj;
717 ppp_unlock(ppp);
718 err = 0;
719 break;
720
721 case PPPIOCGNPMODE:
722 case PPPIOCSNPMODE:
723 if (copy_from_user(&npi, argp, sizeof(npi)))
724 break;
725 err = proto_to_npindex(npi.protocol);
726 if (err < 0)
727 break;
728 i = err;
729 if (cmd == PPPIOCGNPMODE) {
730 err = -EFAULT;
731 npi.mode = ppp->npmode[i];
732 if (copy_to_user(argp, &npi, sizeof(npi)))
733 break;
734 } else {
735 ppp->npmode[i] = npi.mode;
736 /* we may be able to transmit more packets now (??) */
737 netif_wake_queue(ppp->dev);
738 }
739 err = 0;
740 break;
741
742 #ifdef CONFIG_PPP_FILTER
743 case PPPIOCSPASS:
744 {
745 struct sock_filter *code;
746 err = get_filter(argp, &code);
747 if (err >= 0) {
748 ppp_lock(ppp);
749 kfree(ppp->pass_filter);
750 ppp->pass_filter = code;
751 ppp->pass_len = err;
752 ppp_unlock(ppp);
753 err = 0;
754 }
755 break;
756 }
757 case PPPIOCSACTIVE:
758 {
759 struct sock_filter *code;
760 err = get_filter(argp, &code);
761 if (err >= 0) {
762 ppp_lock(ppp);
763 kfree(ppp->active_filter);
764 ppp->active_filter = code;
765 ppp->active_len = err;
766 ppp_unlock(ppp);
767 err = 0;
768 }
769 break;
770 }
771 #endif /* CONFIG_PPP_FILTER */
772
773 #ifdef CONFIG_PPP_MULTILINK
774 case PPPIOCSMRRU:
775 if (get_user(val, p))
776 break;
777 ppp_recv_lock(ppp);
778 ppp->mrru = val;
779 ppp_recv_unlock(ppp);
780 err = 0;
781 break;
782 #endif /* CONFIG_PPP_MULTILINK */
783
784 default:
785 err = -ENOTTY;
786 }
787 unlock_kernel();
788 return err;
789 }
790
791 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
792 struct file *file, unsigned int cmd, unsigned long arg)
793 {
794 int unit, err = -EFAULT;
795 struct ppp *ppp;
796 struct channel *chan;
797 struct ppp_net *pn;
798 int __user *p = (int __user *)arg;
799
800 lock_kernel();
801 switch (cmd) {
802 case PPPIOCNEWUNIT:
803 /* Create a new ppp unit */
804 if (get_user(unit, p))
805 break;
806 ppp = ppp_create_interface(net, unit, &err);
807 if (!ppp)
808 break;
809 file->private_data = &ppp->file;
810 ppp->owner = file;
811 err = -EFAULT;
812 if (put_user(ppp->file.index, p))
813 break;
814 err = 0;
815 break;
816
817 case PPPIOCATTACH:
818 /* Attach to an existing ppp unit */
819 if (get_user(unit, p))
820 break;
821 err = -ENXIO;
822 pn = ppp_pernet(net);
823 mutex_lock(&pn->all_ppp_mutex);
824 ppp = ppp_find_unit(pn, unit);
825 if (ppp) {
826 atomic_inc(&ppp->file.refcnt);
827 file->private_data = &ppp->file;
828 err = 0;
829 }
830 mutex_unlock(&pn->all_ppp_mutex);
831 break;
832
833 case PPPIOCATTCHAN:
834 if (get_user(unit, p))
835 break;
836 err = -ENXIO;
837 pn = ppp_pernet(net);
838 spin_lock_bh(&pn->all_channels_lock);
839 chan = ppp_find_channel(pn, unit);
840 if (chan) {
841 atomic_inc(&chan->file.refcnt);
842 file->private_data = &chan->file;
843 err = 0;
844 }
845 spin_unlock_bh(&pn->all_channels_lock);
846 break;
847
848 default:
849 err = -ENOTTY;
850 }
851 unlock_kernel();
852 return err;
853 }
854
855 static const struct file_operations ppp_device_fops = {
856 .owner = THIS_MODULE,
857 .read = ppp_read,
858 .write = ppp_write,
859 .poll = ppp_poll,
860 .unlocked_ioctl = ppp_ioctl,
861 .open = ppp_open,
862 .release = ppp_release
863 };
864
865 static __net_init int ppp_init_net(struct net *net)
866 {
867 struct ppp_net *pn;
868 int err;
869
870 pn = kzalloc(sizeof(*pn), GFP_KERNEL);
871 if (!pn)
872 return -ENOMEM;
873
874 idr_init(&pn->units_idr);
875 mutex_init(&pn->all_ppp_mutex);
876
877 INIT_LIST_HEAD(&pn->all_channels);
878 INIT_LIST_HEAD(&pn->new_channels);
879
880 spin_lock_init(&pn->all_channels_lock);
881
882 err = net_assign_generic(net, ppp_net_id, pn);
883 if (err) {
884 kfree(pn);
885 return err;
886 }
887
888 return 0;
889 }
890
891 static __net_exit void ppp_exit_net(struct net *net)
892 {
893 struct ppp_net *pn;
894
895 pn = net_generic(net, ppp_net_id);
896 idr_destroy(&pn->units_idr);
897 /*
898 * if someone has cached our net then
899 * further net_generic call will return NULL
900 */
901 net_assign_generic(net, ppp_net_id, NULL);
902 kfree(pn);
903 }
904
905 static struct pernet_operations ppp_net_ops = {
906 .init = ppp_init_net,
907 .exit = ppp_exit_net,
908 };
909
910 #define PPP_MAJOR 108
911
912 /* Called at boot time if ppp is compiled into the kernel,
913 or at module load time (from init_module) if compiled as a module. */
914 static int __init ppp_init(void)
915 {
916 int err;
917
918 printk(KERN_INFO "PPP generic driver version " PPP_VERSION "\n");
919
920 err = register_pernet_gen_device(&ppp_net_id, &ppp_net_ops);
921 if (err) {
922 printk(KERN_ERR "failed to register PPP pernet device (%d)\n", err);
923 goto out;
924 }
925
926 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
927 if (err) {
928 printk(KERN_ERR "failed to register PPP device (%d)\n", err);
929 goto out_net;
930 }
931
932 ppp_class = class_create(THIS_MODULE, "ppp");
933 if (IS_ERR(ppp_class)) {
934 err = PTR_ERR(ppp_class);
935 goto out_chrdev;
936 }
937
938 /* not a big deal if we fail here :-) */
939 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
940
941 return 0;
942
943 out_chrdev:
944 unregister_chrdev(PPP_MAJOR, "ppp");
945 out_net:
946 unregister_pernet_gen_device(ppp_net_id, &ppp_net_ops);
947 out:
948 return err;
949 }
950
951 /*
952 * Network interface unit routines.
953 */
954 static netdev_tx_t
955 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
956 {
957 struct ppp *ppp = netdev_priv(dev);
958 int npi, proto;
959 unsigned char *pp;
960
961 npi = ethertype_to_npindex(ntohs(skb->protocol));
962 if (npi < 0)
963 goto outf;
964
965 /* Drop, accept or reject the packet */
966 switch (ppp->npmode[npi]) {
967 case NPMODE_PASS:
968 break;
969 case NPMODE_QUEUE:
970 /* it would be nice to have a way to tell the network
971 system to queue this one up for later. */
972 goto outf;
973 case NPMODE_DROP:
974 case NPMODE_ERROR:
975 goto outf;
976 }
977
978 /* Put the 2-byte PPP protocol number on the front,
979 making sure there is room for the address and control fields. */
980 if (skb_cow_head(skb, PPP_HDRLEN))
981 goto outf;
982
983 pp = skb_push(skb, 2);
984 proto = npindex_to_proto[npi];
985 pp[0] = proto >> 8;
986 pp[1] = proto;
987
988 netif_stop_queue(dev);
989 skb_queue_tail(&ppp->file.xq, skb);
990 ppp_xmit_process(ppp);
991 return NETDEV_TX_OK;
992
993 outf:
994 kfree_skb(skb);
995 ++dev->stats.tx_dropped;
996 return NETDEV_TX_OK;
997 }
998
999 static int
1000 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1001 {
1002 struct ppp *ppp = netdev_priv(dev);
1003 int err = -EFAULT;
1004 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
1005 struct ppp_stats stats;
1006 struct ppp_comp_stats cstats;
1007 char *vers;
1008
1009 switch (cmd) {
1010 case SIOCGPPPSTATS:
1011 ppp_get_stats(ppp, &stats);
1012 if (copy_to_user(addr, &stats, sizeof(stats)))
1013 break;
1014 err = 0;
1015 break;
1016
1017 case SIOCGPPPCSTATS:
1018 memset(&cstats, 0, sizeof(cstats));
1019 if (ppp->xc_state)
1020 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
1021 if (ppp->rc_state)
1022 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
1023 if (copy_to_user(addr, &cstats, sizeof(cstats)))
1024 break;
1025 err = 0;
1026 break;
1027
1028 case SIOCGPPPVER:
1029 vers = PPP_VERSION;
1030 if (copy_to_user(addr, vers, strlen(vers) + 1))
1031 break;
1032 err = 0;
1033 break;
1034
1035 default:
1036 err = -EINVAL;
1037 }
1038
1039 return err;
1040 }
1041
1042 static const struct net_device_ops ppp_netdev_ops = {
1043 .ndo_start_xmit = ppp_start_xmit,
1044 .ndo_do_ioctl = ppp_net_ioctl,
1045 };
1046
1047 static void ppp_setup(struct net_device *dev)
1048 {
1049 dev->netdev_ops = &ppp_netdev_ops;
1050 dev->hard_header_len = PPP_HDRLEN;
1051 dev->mtu = PPP_MTU;
1052 dev->addr_len = 0;
1053 dev->tx_queue_len = 3;
1054 dev->type = ARPHRD_PPP;
1055 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1056 dev->features |= NETIF_F_NETNS_LOCAL;
1057 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1058 }
1059
1060 /*
1061 * Transmit-side routines.
1062 */
1063
1064 /*
1065 * Called to do any work queued up on the transmit side
1066 * that can now be done.
1067 */
1068 static void
1069 ppp_xmit_process(struct ppp *ppp)
1070 {
1071 struct sk_buff *skb;
1072
1073 ppp_xmit_lock(ppp);
1074 if (!ppp->closing) {
1075 ppp_push(ppp);
1076 while (!ppp->xmit_pending
1077 && (skb = skb_dequeue(&ppp->file.xq)))
1078 ppp_send_frame(ppp, skb);
1079 /* If there's no work left to do, tell the core net
1080 code that we can accept some more. */
1081 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1082 netif_wake_queue(ppp->dev);
1083 }
1084 ppp_xmit_unlock(ppp);
1085 }
1086
1087 static inline struct sk_buff *
1088 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1089 {
1090 struct sk_buff *new_skb;
1091 int len;
1092 int new_skb_size = ppp->dev->mtu +
1093 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1094 int compressor_skb_size = ppp->dev->mtu +
1095 ppp->xcomp->comp_extra + PPP_HDRLEN;
1096 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1097 if (!new_skb) {
1098 if (net_ratelimit())
1099 printk(KERN_ERR "PPP: no memory (comp pkt)\n");
1100 return NULL;
1101 }
1102 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1103 skb_reserve(new_skb,
1104 ppp->dev->hard_header_len - PPP_HDRLEN);
1105
1106 /* compressor still expects A/C bytes in hdr */
1107 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1108 new_skb->data, skb->len + 2,
1109 compressor_skb_size);
1110 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1111 kfree_skb(skb);
1112 skb = new_skb;
1113 skb_put(skb, len);
1114 skb_pull(skb, 2); /* pull off A/C bytes */
1115 } else if (len == 0) {
1116 /* didn't compress, or CCP not up yet */
1117 kfree_skb(new_skb);
1118 new_skb = skb;
1119 } else {
1120 /*
1121 * (len < 0)
1122 * MPPE requires that we do not send unencrypted
1123 * frames. The compressor will return -1 if we
1124 * should drop the frame. We cannot simply test
1125 * the compress_proto because MPPE and MPPC share
1126 * the same number.
1127 */
1128 if (net_ratelimit())
1129 printk(KERN_ERR "ppp: compressor dropped pkt\n");
1130 kfree_skb(skb);
1131 kfree_skb(new_skb);
1132 new_skb = NULL;
1133 }
1134 return new_skb;
1135 }
1136
1137 /*
1138 * Compress and send a frame.
1139 * The caller should have locked the xmit path,
1140 * and xmit_pending should be 0.
1141 */
1142 static void
1143 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1144 {
1145 int proto = PPP_PROTO(skb);
1146 struct sk_buff *new_skb;
1147 int len;
1148 unsigned char *cp;
1149
1150 if (proto < 0x8000) {
1151 #ifdef CONFIG_PPP_FILTER
1152 /* check if we should pass this packet */
1153 /* the filter instructions are constructed assuming
1154 a four-byte PPP header on each packet */
1155 *skb_push(skb, 2) = 1;
1156 if (ppp->pass_filter
1157 && sk_run_filter(skb, ppp->pass_filter,
1158 ppp->pass_len) == 0) {
1159 if (ppp->debug & 1)
1160 printk(KERN_DEBUG "PPP: outbound frame not passed\n");
1161 kfree_skb(skb);
1162 return;
1163 }
1164 /* if this packet passes the active filter, record the time */
1165 if (!(ppp->active_filter
1166 && sk_run_filter(skb, ppp->active_filter,
1167 ppp->active_len) == 0))
1168 ppp->last_xmit = jiffies;
1169 skb_pull(skb, 2);
1170 #else
1171 /* for data packets, record the time */
1172 ppp->last_xmit = jiffies;
1173 #endif /* CONFIG_PPP_FILTER */
1174 }
1175
1176 ++ppp->dev->stats.tx_packets;
1177 ppp->dev->stats.tx_bytes += skb->len - 2;
1178
1179 switch (proto) {
1180 case PPP_IP:
1181 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1182 break;
1183 /* try to do VJ TCP header compression */
1184 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1185 GFP_ATOMIC);
1186 if (!new_skb) {
1187 printk(KERN_ERR "PPP: no memory (VJ comp pkt)\n");
1188 goto drop;
1189 }
1190 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1191 cp = skb->data + 2;
1192 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1193 new_skb->data + 2, &cp,
1194 !(ppp->flags & SC_NO_TCP_CCID));
1195 if (cp == skb->data + 2) {
1196 /* didn't compress */
1197 kfree_skb(new_skb);
1198 } else {
1199 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1200 proto = PPP_VJC_COMP;
1201 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1202 } else {
1203 proto = PPP_VJC_UNCOMP;
1204 cp[0] = skb->data[2];
1205 }
1206 kfree_skb(skb);
1207 skb = new_skb;
1208 cp = skb_put(skb, len + 2);
1209 cp[0] = 0;
1210 cp[1] = proto;
1211 }
1212 break;
1213
1214 case PPP_CCP:
1215 /* peek at outbound CCP frames */
1216 ppp_ccp_peek(ppp, skb, 0);
1217 break;
1218 }
1219
1220 /* try to do packet compression */
1221 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state
1222 && proto != PPP_LCP && proto != PPP_CCP) {
1223 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1224 if (net_ratelimit())
1225 printk(KERN_ERR "ppp: compression required but down - pkt dropped.\n");
1226 goto drop;
1227 }
1228 skb = pad_compress_skb(ppp, skb);
1229 if (!skb)
1230 goto drop;
1231 }
1232
1233 /*
1234 * If we are waiting for traffic (demand dialling),
1235 * queue it up for pppd to receive.
1236 */
1237 if (ppp->flags & SC_LOOP_TRAFFIC) {
1238 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1239 goto drop;
1240 skb_queue_tail(&ppp->file.rq, skb);
1241 wake_up_interruptible(&ppp->file.rwait);
1242 return;
1243 }
1244
1245 ppp->xmit_pending = skb;
1246 ppp_push(ppp);
1247 return;
1248
1249 drop:
1250 kfree_skb(skb);
1251 ++ppp->dev->stats.tx_errors;
1252 }
1253
1254 /*
1255 * Try to send the frame in xmit_pending.
1256 * The caller should have the xmit path locked.
1257 */
1258 static void
1259 ppp_push(struct ppp *ppp)
1260 {
1261 struct list_head *list;
1262 struct channel *pch;
1263 struct sk_buff *skb = ppp->xmit_pending;
1264
1265 if (!skb)
1266 return;
1267
1268 list = &ppp->channels;
1269 if (list_empty(list)) {
1270 /* nowhere to send the packet, just drop it */
1271 ppp->xmit_pending = NULL;
1272 kfree_skb(skb);
1273 return;
1274 }
1275
1276 if ((ppp->flags & SC_MULTILINK) == 0) {
1277 /* not doing multilink: send it down the first channel */
1278 list = list->next;
1279 pch = list_entry(list, struct channel, clist);
1280
1281 spin_lock_bh(&pch->downl);
1282 if (pch->chan) {
1283 if (pch->chan->ops->start_xmit(pch->chan, skb))
1284 ppp->xmit_pending = NULL;
1285 } else {
1286 /* channel got unregistered */
1287 kfree_skb(skb);
1288 ppp->xmit_pending = NULL;
1289 }
1290 spin_unlock_bh(&pch->downl);
1291 return;
1292 }
1293
1294 #ifdef CONFIG_PPP_MULTILINK
1295 /* Multilink: fragment the packet over as many links
1296 as can take the packet at the moment. */
1297 if (!ppp_mp_explode(ppp, skb))
1298 return;
1299 #endif /* CONFIG_PPP_MULTILINK */
1300
1301 ppp->xmit_pending = NULL;
1302 kfree_skb(skb);
1303 }
1304
1305 #ifdef CONFIG_PPP_MULTILINK
1306 /*
1307 * Divide a packet to be transmitted into fragments and
1308 * send them out the individual links.
1309 */
1310 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1311 {
1312 int len, totlen;
1313 int i, bits, hdrlen, mtu;
1314 int flen;
1315 int navail, nfree, nzero;
1316 int nbigger;
1317 int totspeed;
1318 int totfree;
1319 unsigned char *p, *q;
1320 struct list_head *list;
1321 struct channel *pch;
1322 struct sk_buff *frag;
1323 struct ppp_channel *chan;
1324
1325 totspeed = 0; /*total bitrate of the bundle*/
1326 nfree = 0; /* # channels which have no packet already queued */
1327 navail = 0; /* total # of usable channels (not deregistered) */
1328 nzero = 0; /* number of channels with zero speed associated*/
1329 totfree = 0; /*total # of channels available and
1330 *having no queued packets before
1331 *starting the fragmentation*/
1332
1333 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1334 i = 0;
1335 list_for_each_entry(pch, &ppp->channels, clist) {
1336 navail += pch->avail = (pch->chan != NULL);
1337 pch->speed = pch->chan->speed;
1338 if (pch->avail) {
1339 if (skb_queue_empty(&pch->file.xq) ||
1340 !pch->had_frag) {
1341 if (pch->speed == 0)
1342 nzero++;
1343 else
1344 totspeed += pch->speed;
1345
1346 pch->avail = 2;
1347 ++nfree;
1348 ++totfree;
1349 }
1350 if (!pch->had_frag && i < ppp->nxchan)
1351 ppp->nxchan = i;
1352 }
1353 ++i;
1354 }
1355 /*
1356 * Don't start sending this packet unless at least half of
1357 * the channels are free. This gives much better TCP
1358 * performance if we have a lot of channels.
1359 */
1360 if (nfree == 0 || nfree < navail / 2)
1361 return 0; /* can't take now, leave it in xmit_pending */
1362
1363 /* Do protocol field compression (XXX this should be optional) */
1364 p = skb->data;
1365 len = skb->len;
1366 if (*p == 0) {
1367 ++p;
1368 --len;
1369 }
1370
1371 totlen = len;
1372 nbigger = len % nfree;
1373
1374 /* skip to the channel after the one we last used
1375 and start at that one */
1376 list = &ppp->channels;
1377 for (i = 0; i < ppp->nxchan; ++i) {
1378 list = list->next;
1379 if (list == &ppp->channels) {
1380 i = 0;
1381 break;
1382 }
1383 }
1384
1385 /* create a fragment for each channel */
1386 bits = B;
1387 while (len > 0) {
1388 list = list->next;
1389 if (list == &ppp->channels) {
1390 i = 0;
1391 continue;
1392 }
1393 pch = list_entry(list, struct channel, clist);
1394 ++i;
1395 if (!pch->avail)
1396 continue;
1397
1398 /*
1399 * Skip this channel if it has a fragment pending already and
1400 * we haven't given a fragment to all of the free channels.
1401 */
1402 if (pch->avail == 1) {
1403 if (nfree > 0)
1404 continue;
1405 } else {
1406 pch->avail = 1;
1407 }
1408
1409 /* check the channel's mtu and whether it is still attached. */
1410 spin_lock_bh(&pch->downl);
1411 if (pch->chan == NULL) {
1412 /* can't use this channel, it's being deregistered */
1413 if (pch->speed == 0)
1414 nzero--;
1415 else
1416 totspeed -= pch->speed;
1417
1418 spin_unlock_bh(&pch->downl);
1419 pch->avail = 0;
1420 totlen = len;
1421 totfree--;
1422 nfree--;
1423 if (--navail == 0)
1424 break;
1425 continue;
1426 }
1427
1428 /*
1429 *if the channel speed is not set divide
1430 *the packet evenly among the free channels;
1431 *otherwise divide it according to the speed
1432 *of the channel we are going to transmit on
1433 */
1434 flen = len;
1435 if (nfree > 0) {
1436 if (pch->speed == 0) {
1437 flen = totlen/nfree ;
1438 if (nbigger > 0) {
1439 flen++;
1440 nbigger--;
1441 }
1442 } else {
1443 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
1444 ((totspeed*totfree)/pch->speed)) - hdrlen;
1445 if (nbigger > 0) {
1446 flen += ((totfree - nzero)*pch->speed)/totspeed;
1447 nbigger -= ((totfree - nzero)*pch->speed)/
1448 totspeed;
1449 }
1450 }
1451 nfree--;
1452 }
1453
1454 /*
1455 *check if we are on the last channel or
1456 *we exceded the lenght of the data to
1457 *fragment
1458 */
1459 if ((nfree <= 0) || (flen > len))
1460 flen = len;
1461 /*
1462 *it is not worth to tx on slow channels:
1463 *in that case from the resulting flen according to the
1464 *above formula will be equal or less than zero.
1465 *Skip the channel in this case
1466 */
1467 if (flen <= 0) {
1468 pch->avail = 2;
1469 spin_unlock_bh(&pch->downl);
1470 continue;
1471 }
1472
1473 mtu = pch->chan->mtu - hdrlen;
1474 if (mtu < 4)
1475 mtu = 4;
1476 if (flen > mtu)
1477 flen = mtu;
1478 if (flen == len)
1479 bits |= E;
1480 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1481 if (!frag)
1482 goto noskb;
1483 q = skb_put(frag, flen + hdrlen);
1484
1485 /* make the MP header */
1486 q[0] = PPP_MP >> 8;
1487 q[1] = PPP_MP;
1488 if (ppp->flags & SC_MP_XSHORTSEQ) {
1489 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1490 q[3] = ppp->nxseq;
1491 } else {
1492 q[2] = bits;
1493 q[3] = ppp->nxseq >> 16;
1494 q[4] = ppp->nxseq >> 8;
1495 q[5] = ppp->nxseq;
1496 }
1497
1498 memcpy(q + hdrlen, p, flen);
1499
1500 /* try to send it down the channel */
1501 chan = pch->chan;
1502 if (!skb_queue_empty(&pch->file.xq) ||
1503 !chan->ops->start_xmit(chan, frag))
1504 skb_queue_tail(&pch->file.xq, frag);
1505 pch->had_frag = 1;
1506 p += flen;
1507 len -= flen;
1508 ++ppp->nxseq;
1509 bits = 0;
1510 spin_unlock_bh(&pch->downl);
1511 }
1512 ppp->nxchan = i;
1513
1514 return 1;
1515
1516 noskb:
1517 spin_unlock_bh(&pch->downl);
1518 if (ppp->debug & 1)
1519 printk(KERN_ERR "PPP: no memory (fragment)\n");
1520 ++ppp->dev->stats.tx_errors;
1521 ++ppp->nxseq;
1522 return 1; /* abandon the frame */
1523 }
1524 #endif /* CONFIG_PPP_MULTILINK */
1525
1526 /*
1527 * Try to send data out on a channel.
1528 */
1529 static void
1530 ppp_channel_push(struct channel *pch)
1531 {
1532 struct sk_buff *skb;
1533 struct ppp *ppp;
1534
1535 spin_lock_bh(&pch->downl);
1536 if (pch->chan) {
1537 while (!skb_queue_empty(&pch->file.xq)) {
1538 skb = skb_dequeue(&pch->file.xq);
1539 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1540 /* put the packet back and try again later */
1541 skb_queue_head(&pch->file.xq, skb);
1542 break;
1543 }
1544 }
1545 } else {
1546 /* channel got deregistered */
1547 skb_queue_purge(&pch->file.xq);
1548 }
1549 spin_unlock_bh(&pch->downl);
1550 /* see if there is anything from the attached unit to be sent */
1551 if (skb_queue_empty(&pch->file.xq)) {
1552 read_lock_bh(&pch->upl);
1553 ppp = pch->ppp;
1554 if (ppp)
1555 ppp_xmit_process(ppp);
1556 read_unlock_bh(&pch->upl);
1557 }
1558 }
1559
1560 /*
1561 * Receive-side routines.
1562 */
1563
1564 /* misuse a few fields of the skb for MP reconstruction */
1565 #define sequence priority
1566 #define BEbits cb[0]
1567
1568 static inline void
1569 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1570 {
1571 ppp_recv_lock(ppp);
1572 if (!ppp->closing)
1573 ppp_receive_frame(ppp, skb, pch);
1574 else
1575 kfree_skb(skb);
1576 ppp_recv_unlock(ppp);
1577 }
1578
1579 void
1580 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1581 {
1582 struct channel *pch = chan->ppp;
1583 int proto;
1584
1585 if (!pch || skb->len == 0) {
1586 kfree_skb(skb);
1587 return;
1588 }
1589
1590 proto = PPP_PROTO(skb);
1591 read_lock_bh(&pch->upl);
1592 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1593 /* put it on the channel queue */
1594 skb_queue_tail(&pch->file.rq, skb);
1595 /* drop old frames if queue too long */
1596 while (pch->file.rq.qlen > PPP_MAX_RQLEN
1597 && (skb = skb_dequeue(&pch->file.rq)))
1598 kfree_skb(skb);
1599 wake_up_interruptible(&pch->file.rwait);
1600 } else {
1601 ppp_do_recv(pch->ppp, skb, pch);
1602 }
1603 read_unlock_bh(&pch->upl);
1604 }
1605
1606 /* Put a 0-length skb in the receive queue as an error indication */
1607 void
1608 ppp_input_error(struct ppp_channel *chan, int code)
1609 {
1610 struct channel *pch = chan->ppp;
1611 struct sk_buff *skb;
1612
1613 if (!pch)
1614 return;
1615
1616 read_lock_bh(&pch->upl);
1617 if (pch->ppp) {
1618 skb = alloc_skb(0, GFP_ATOMIC);
1619 if (skb) {
1620 skb->len = 0; /* probably unnecessary */
1621 skb->cb[0] = code;
1622 ppp_do_recv(pch->ppp, skb, pch);
1623 }
1624 }
1625 read_unlock_bh(&pch->upl);
1626 }
1627
1628 /*
1629 * We come in here to process a received frame.
1630 * The receive side of the ppp unit is locked.
1631 */
1632 static void
1633 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1634 {
1635 if (pskb_may_pull(skb, 2)) {
1636 #ifdef CONFIG_PPP_MULTILINK
1637 /* XXX do channel-level decompression here */
1638 if (PPP_PROTO(skb) == PPP_MP)
1639 ppp_receive_mp_frame(ppp, skb, pch);
1640 else
1641 #endif /* CONFIG_PPP_MULTILINK */
1642 ppp_receive_nonmp_frame(ppp, skb);
1643 return;
1644 }
1645
1646 if (skb->len > 0)
1647 /* note: a 0-length skb is used as an error indication */
1648 ++ppp->dev->stats.rx_length_errors;
1649
1650 kfree_skb(skb);
1651 ppp_receive_error(ppp);
1652 }
1653
1654 static void
1655 ppp_receive_error(struct ppp *ppp)
1656 {
1657 ++ppp->dev->stats.rx_errors;
1658 if (ppp->vj)
1659 slhc_toss(ppp->vj);
1660 }
1661
1662 static void
1663 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1664 {
1665 struct sk_buff *ns;
1666 int proto, len, npi;
1667
1668 /*
1669 * Decompress the frame, if compressed.
1670 * Note that some decompressors need to see uncompressed frames
1671 * that come in as well as compressed frames.
1672 */
1673 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)
1674 && (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1675 skb = ppp_decompress_frame(ppp, skb);
1676
1677 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1678 goto err;
1679
1680 proto = PPP_PROTO(skb);
1681 switch (proto) {
1682 case PPP_VJC_COMP:
1683 /* decompress VJ compressed packets */
1684 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1685 goto err;
1686
1687 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1688 /* copy to a new sk_buff with more tailroom */
1689 ns = dev_alloc_skb(skb->len + 128);
1690 if (!ns) {
1691 printk(KERN_ERR"PPP: no memory (VJ decomp)\n");
1692 goto err;
1693 }
1694 skb_reserve(ns, 2);
1695 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1696 kfree_skb(skb);
1697 skb = ns;
1698 }
1699 else
1700 skb->ip_summed = CHECKSUM_NONE;
1701
1702 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1703 if (len <= 0) {
1704 printk(KERN_DEBUG "PPP: VJ decompression error\n");
1705 goto err;
1706 }
1707 len += 2;
1708 if (len > skb->len)
1709 skb_put(skb, len - skb->len);
1710 else if (len < skb->len)
1711 skb_trim(skb, len);
1712 proto = PPP_IP;
1713 break;
1714
1715 case PPP_VJC_UNCOMP:
1716 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1717 goto err;
1718
1719 /* Until we fix the decompressor need to make sure
1720 * data portion is linear.
1721 */
1722 if (!pskb_may_pull(skb, skb->len))
1723 goto err;
1724
1725 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1726 printk(KERN_ERR "PPP: VJ uncompressed error\n");
1727 goto err;
1728 }
1729 proto = PPP_IP;
1730 break;
1731
1732 case PPP_CCP:
1733 ppp_ccp_peek(ppp, skb, 1);
1734 break;
1735 }
1736
1737 ++ppp->dev->stats.rx_packets;
1738 ppp->dev->stats.rx_bytes += skb->len - 2;
1739
1740 npi = proto_to_npindex(proto);
1741 if (npi < 0) {
1742 /* control or unknown frame - pass it to pppd */
1743 skb_queue_tail(&ppp->file.rq, skb);
1744 /* limit queue length by dropping old frames */
1745 while (ppp->file.rq.qlen > PPP_MAX_RQLEN
1746 && (skb = skb_dequeue(&ppp->file.rq)))
1747 kfree_skb(skb);
1748 /* wake up any process polling or blocking on read */
1749 wake_up_interruptible(&ppp->file.rwait);
1750
1751 } else {
1752 /* network protocol frame - give it to the kernel */
1753
1754 #ifdef CONFIG_PPP_FILTER
1755 /* check if the packet passes the pass and active filters */
1756 /* the filter instructions are constructed assuming
1757 a four-byte PPP header on each packet */
1758 if (ppp->pass_filter || ppp->active_filter) {
1759 if (skb_cloned(skb) &&
1760 pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
1761 goto err;
1762
1763 *skb_push(skb, 2) = 0;
1764 if (ppp->pass_filter
1765 && sk_run_filter(skb, ppp->pass_filter,
1766 ppp->pass_len) == 0) {
1767 if (ppp->debug & 1)
1768 printk(KERN_DEBUG "PPP: inbound frame "
1769 "not passed\n");
1770 kfree_skb(skb);
1771 return;
1772 }
1773 if (!(ppp->active_filter
1774 && sk_run_filter(skb, ppp->active_filter,
1775 ppp->active_len) == 0))
1776 ppp->last_recv = jiffies;
1777 __skb_pull(skb, 2);
1778 } else
1779 #endif /* CONFIG_PPP_FILTER */
1780 ppp->last_recv = jiffies;
1781
1782 if ((ppp->dev->flags & IFF_UP) == 0
1783 || ppp->npmode[npi] != NPMODE_PASS) {
1784 kfree_skb(skb);
1785 } else {
1786 /* chop off protocol */
1787 skb_pull_rcsum(skb, 2);
1788 skb->dev = ppp->dev;
1789 skb->protocol = htons(npindex_to_ethertype[npi]);
1790 skb_reset_mac_header(skb);
1791 netif_rx(skb);
1792 }
1793 }
1794 return;
1795
1796 err:
1797 kfree_skb(skb);
1798 ppp_receive_error(ppp);
1799 }
1800
1801 static struct sk_buff *
1802 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1803 {
1804 int proto = PPP_PROTO(skb);
1805 struct sk_buff *ns;
1806 int len;
1807
1808 /* Until we fix all the decompressor's need to make sure
1809 * data portion is linear.
1810 */
1811 if (!pskb_may_pull(skb, skb->len))
1812 goto err;
1813
1814 if (proto == PPP_COMP) {
1815 int obuff_size;
1816
1817 switch(ppp->rcomp->compress_proto) {
1818 case CI_MPPE:
1819 obuff_size = ppp->mru + PPP_HDRLEN + 1;
1820 break;
1821 default:
1822 obuff_size = ppp->mru + PPP_HDRLEN;
1823 break;
1824 }
1825
1826 ns = dev_alloc_skb(obuff_size);
1827 if (!ns) {
1828 printk(KERN_ERR "ppp_decompress_frame: no memory\n");
1829 goto err;
1830 }
1831 /* the decompressor still expects the A/C bytes in the hdr */
1832 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1833 skb->len + 2, ns->data, obuff_size);
1834 if (len < 0) {
1835 /* Pass the compressed frame to pppd as an
1836 error indication. */
1837 if (len == DECOMP_FATALERROR)
1838 ppp->rstate |= SC_DC_FERROR;
1839 kfree_skb(ns);
1840 goto err;
1841 }
1842
1843 kfree_skb(skb);
1844 skb = ns;
1845 skb_put(skb, len);
1846 skb_pull(skb, 2); /* pull off the A/C bytes */
1847
1848 } else {
1849 /* Uncompressed frame - pass to decompressor so it
1850 can update its dictionary if necessary. */
1851 if (ppp->rcomp->incomp)
1852 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1853 skb->len + 2);
1854 }
1855
1856 return skb;
1857
1858 err:
1859 ppp->rstate |= SC_DC_ERROR;
1860 ppp_receive_error(ppp);
1861 return skb;
1862 }
1863
1864 #ifdef CONFIG_PPP_MULTILINK
1865 /*
1866 * Receive a multilink frame.
1867 * We put it on the reconstruction queue and then pull off
1868 * as many completed frames as we can.
1869 */
1870 static void
1871 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1872 {
1873 u32 mask, seq;
1874 struct channel *ch;
1875 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1876
1877 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
1878 goto err; /* no good, throw it away */
1879
1880 /* Decode sequence number and begin/end bits */
1881 if (ppp->flags & SC_MP_SHORTSEQ) {
1882 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1883 mask = 0xfff;
1884 } else {
1885 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1886 mask = 0xffffff;
1887 }
1888 skb->BEbits = skb->data[2];
1889 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
1890
1891 /*
1892 * Do protocol ID decompression on the first fragment of each packet.
1893 */
1894 if ((skb->BEbits & B) && (skb->data[0] & 1))
1895 *skb_push(skb, 1) = 0;
1896
1897 /*
1898 * Expand sequence number to 32 bits, making it as close
1899 * as possible to ppp->minseq.
1900 */
1901 seq |= ppp->minseq & ~mask;
1902 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
1903 seq += mask + 1;
1904 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
1905 seq -= mask + 1; /* should never happen */
1906 skb->sequence = seq;
1907 pch->lastseq = seq;
1908
1909 /*
1910 * If this packet comes before the next one we were expecting,
1911 * drop it.
1912 */
1913 if (seq_before(seq, ppp->nextseq)) {
1914 kfree_skb(skb);
1915 ++ppp->dev->stats.rx_dropped;
1916 ppp_receive_error(ppp);
1917 return;
1918 }
1919
1920 /*
1921 * Reevaluate minseq, the minimum over all channels of the
1922 * last sequence number received on each channel. Because of
1923 * the increasing sequence number rule, we know that any fragment
1924 * before `minseq' which hasn't arrived is never going to arrive.
1925 * The list of channels can't change because we have the receive
1926 * side of the ppp unit locked.
1927 */
1928 list_for_each_entry(ch, &ppp->channels, clist) {
1929 if (seq_before(ch->lastseq, seq))
1930 seq = ch->lastseq;
1931 }
1932 if (seq_before(ppp->minseq, seq))
1933 ppp->minseq = seq;
1934
1935 /* Put the fragment on the reconstruction queue */
1936 ppp_mp_insert(ppp, skb);
1937
1938 /* If the queue is getting long, don't wait any longer for packets
1939 before the start of the queue. */
1940 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
1941 struct sk_buff *skb = skb_peek(&ppp->mrq);
1942 if (seq_before(ppp->minseq, skb->sequence))
1943 ppp->minseq = skb->sequence;
1944 }
1945
1946 /* Pull completed packets off the queue and receive them. */
1947 while ((skb = ppp_mp_reconstruct(ppp))) {
1948 if (pskb_may_pull(skb, 2))
1949 ppp_receive_nonmp_frame(ppp, skb);
1950 else {
1951 ++ppp->dev->stats.rx_length_errors;
1952 kfree_skb(skb);
1953 ppp_receive_error(ppp);
1954 }
1955 }
1956
1957 return;
1958
1959 err:
1960 kfree_skb(skb);
1961 ppp_receive_error(ppp);
1962 }
1963
1964 /*
1965 * Insert a fragment on the MP reconstruction queue.
1966 * The queue is ordered by increasing sequence number.
1967 */
1968 static void
1969 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
1970 {
1971 struct sk_buff *p;
1972 struct sk_buff_head *list = &ppp->mrq;
1973 u32 seq = skb->sequence;
1974
1975 /* N.B. we don't need to lock the list lock because we have the
1976 ppp unit receive-side lock. */
1977 skb_queue_walk(list, p) {
1978 if (seq_before(seq, p->sequence))
1979 break;
1980 }
1981 __skb_queue_before(list, p, skb);
1982 }
1983
1984 /*
1985 * Reconstruct a packet from the MP fragment queue.
1986 * We go through increasing sequence numbers until we find a
1987 * complete packet, or we get to the sequence number for a fragment
1988 * which hasn't arrived but might still do so.
1989 */
1990 static struct sk_buff *
1991 ppp_mp_reconstruct(struct ppp *ppp)
1992 {
1993 u32 seq = ppp->nextseq;
1994 u32 minseq = ppp->minseq;
1995 struct sk_buff_head *list = &ppp->mrq;
1996 struct sk_buff *p, *next;
1997 struct sk_buff *head, *tail;
1998 struct sk_buff *skb = NULL;
1999 int lost = 0, len = 0;
2000
2001 if (ppp->mrru == 0) /* do nothing until mrru is set */
2002 return NULL;
2003 head = list->next;
2004 tail = NULL;
2005 for (p = head; p != (struct sk_buff *) list; p = next) {
2006 next = p->next;
2007 if (seq_before(p->sequence, seq)) {
2008 /* this can't happen, anyway ignore the skb */
2009 printk(KERN_ERR "ppp_mp_reconstruct bad seq %u < %u\n",
2010 p->sequence, seq);
2011 head = next;
2012 continue;
2013 }
2014 if (p->sequence != seq) {
2015 /* Fragment `seq' is missing. If it is after
2016 minseq, it might arrive later, so stop here. */
2017 if (seq_after(seq, minseq))
2018 break;
2019 /* Fragment `seq' is lost, keep going. */
2020 lost = 1;
2021 seq = seq_before(minseq, p->sequence)?
2022 minseq + 1: p->sequence;
2023 next = p;
2024 continue;
2025 }
2026
2027 /*
2028 * At this point we know that all the fragments from
2029 * ppp->nextseq to seq are either present or lost.
2030 * Also, there are no complete packets in the queue
2031 * that have no missing fragments and end before this
2032 * fragment.
2033 */
2034
2035 /* B bit set indicates this fragment starts a packet */
2036 if (p->BEbits & B) {
2037 head = p;
2038 lost = 0;
2039 len = 0;
2040 }
2041
2042 len += p->len;
2043
2044 /* Got a complete packet yet? */
2045 if (lost == 0 && (p->BEbits & E) && (head->BEbits & B)) {
2046 if (len > ppp->mrru + 2) {
2047 ++ppp->dev->stats.rx_length_errors;
2048 printk(KERN_DEBUG "PPP: reconstructed packet"
2049 " is too long (%d)\n", len);
2050 } else if (p == head) {
2051 /* fragment is complete packet - reuse skb */
2052 tail = p;
2053 skb = skb_get(p);
2054 break;
2055 } else if ((skb = dev_alloc_skb(len)) == NULL) {
2056 ++ppp->dev->stats.rx_missed_errors;
2057 printk(KERN_DEBUG "PPP: no memory for "
2058 "reconstructed packet");
2059 } else {
2060 tail = p;
2061 break;
2062 }
2063 ppp->nextseq = seq + 1;
2064 }
2065
2066 /*
2067 * If this is the ending fragment of a packet,
2068 * and we haven't found a complete valid packet yet,
2069 * we can discard up to and including this fragment.
2070 */
2071 if (p->BEbits & E)
2072 head = next;
2073
2074 ++seq;
2075 }
2076
2077 /* If we have a complete packet, copy it all into one skb. */
2078 if (tail != NULL) {
2079 /* If we have discarded any fragments,
2080 signal a receive error. */
2081 if (head->sequence != ppp->nextseq) {
2082 if (ppp->debug & 1)
2083 printk(KERN_DEBUG " missed pkts %u..%u\n",
2084 ppp->nextseq, head->sequence-1);
2085 ++ppp->dev->stats.rx_dropped;
2086 ppp_receive_error(ppp);
2087 }
2088
2089 if (head != tail)
2090 /* copy to a single skb */
2091 for (p = head; p != tail->next; p = p->next)
2092 skb_copy_bits(p, 0, skb_put(skb, p->len), p->len);
2093 ppp->nextseq = tail->sequence + 1;
2094 head = tail->next;
2095 }
2096
2097 /* Discard all the skbuffs that we have copied the data out of
2098 or that we can't use. */
2099 while ((p = list->next) != head) {
2100 __skb_unlink(p, list);
2101 kfree_skb(p);
2102 }
2103
2104 return skb;
2105 }
2106 #endif /* CONFIG_PPP_MULTILINK */
2107
2108 /*
2109 * Channel interface.
2110 */
2111
2112 /* Create a new, unattached ppp channel. */
2113 int ppp_register_channel(struct ppp_channel *chan)
2114 {
2115 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2116 }
2117
2118 /* Create a new, unattached ppp channel for specified net. */
2119 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
2120 {
2121 struct channel *pch;
2122 struct ppp_net *pn;
2123
2124 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2125 if (!pch)
2126 return -ENOMEM;
2127
2128 pn = ppp_pernet(net);
2129
2130 pch->ppp = NULL;
2131 pch->chan = chan;
2132 pch->chan_net = net;
2133 chan->ppp = pch;
2134 init_ppp_file(&pch->file, CHANNEL);
2135 pch->file.hdrlen = chan->hdrlen;
2136 #ifdef CONFIG_PPP_MULTILINK
2137 pch->lastseq = -1;
2138 #endif /* CONFIG_PPP_MULTILINK */
2139 init_rwsem(&pch->chan_sem);
2140 spin_lock_init(&pch->downl);
2141 rwlock_init(&pch->upl);
2142
2143 spin_lock_bh(&pn->all_channels_lock);
2144 pch->file.index = ++pn->last_channel_index;
2145 list_add(&pch->list, &pn->new_channels);
2146 atomic_inc(&channel_count);
2147 spin_unlock_bh(&pn->all_channels_lock);
2148
2149 return 0;
2150 }
2151
2152 /*
2153 * Return the index of a channel.
2154 */
2155 int ppp_channel_index(struct ppp_channel *chan)
2156 {
2157 struct channel *pch = chan->ppp;
2158
2159 if (pch)
2160 return pch->file.index;
2161 return -1;
2162 }
2163
2164 /*
2165 * Return the PPP unit number to which a channel is connected.
2166 */
2167 int ppp_unit_number(struct ppp_channel *chan)
2168 {
2169 struct channel *pch = chan->ppp;
2170 int unit = -1;
2171
2172 if (pch) {
2173 read_lock_bh(&pch->upl);
2174 if (pch->ppp)
2175 unit = pch->ppp->file.index;
2176 read_unlock_bh(&pch->upl);
2177 }
2178 return unit;
2179 }
2180
2181 /*
2182 * Disconnect a channel from the generic layer.
2183 * This must be called in process context.
2184 */
2185 void
2186 ppp_unregister_channel(struct ppp_channel *chan)
2187 {
2188 struct channel *pch = chan->ppp;
2189 struct ppp_net *pn;
2190
2191 if (!pch)
2192 return; /* should never happen */
2193
2194 chan->ppp = NULL;
2195
2196 /*
2197 * This ensures that we have returned from any calls into the
2198 * the channel's start_xmit or ioctl routine before we proceed.
2199 */
2200 down_write(&pch->chan_sem);
2201 spin_lock_bh(&pch->downl);
2202 pch->chan = NULL;
2203 spin_unlock_bh(&pch->downl);
2204 up_write(&pch->chan_sem);
2205 ppp_disconnect_channel(pch);
2206
2207 pn = ppp_pernet(pch->chan_net);
2208 spin_lock_bh(&pn->all_channels_lock);
2209 list_del(&pch->list);
2210 spin_unlock_bh(&pn->all_channels_lock);
2211
2212 pch->file.dead = 1;
2213 wake_up_interruptible(&pch->file.rwait);
2214 if (atomic_dec_and_test(&pch->file.refcnt))
2215 ppp_destroy_channel(pch);
2216 }
2217
2218 /*
2219 * Callback from a channel when it can accept more to transmit.
2220 * This should be called at BH/softirq level, not interrupt level.
2221 */
2222 void
2223 ppp_output_wakeup(struct ppp_channel *chan)
2224 {
2225 struct channel *pch = chan->ppp;
2226
2227 if (!pch)
2228 return;
2229 ppp_channel_push(pch);
2230 }
2231
2232 /*
2233 * Compression control.
2234 */
2235
2236 /* Process the PPPIOCSCOMPRESS ioctl. */
2237 static int
2238 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2239 {
2240 int err;
2241 struct compressor *cp, *ocomp;
2242 struct ppp_option_data data;
2243 void *state, *ostate;
2244 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2245
2246 err = -EFAULT;
2247 if (copy_from_user(&data, (void __user *) arg, sizeof(data))
2248 || (data.length <= CCP_MAX_OPTION_LENGTH
2249 && copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2250 goto out;
2251 err = -EINVAL;
2252 if (data.length > CCP_MAX_OPTION_LENGTH
2253 || ccp_option[1] < 2 || ccp_option[1] > data.length)
2254 goto out;
2255
2256 cp = try_then_request_module(
2257 find_compressor(ccp_option[0]),
2258 "ppp-compress-%d", ccp_option[0]);
2259 if (!cp)
2260 goto out;
2261
2262 err = -ENOBUFS;
2263 if (data.transmit) {
2264 state = cp->comp_alloc(ccp_option, data.length);
2265 if (state) {
2266 ppp_xmit_lock(ppp);
2267 ppp->xstate &= ~SC_COMP_RUN;
2268 ocomp = ppp->xcomp;
2269 ostate = ppp->xc_state;
2270 ppp->xcomp = cp;
2271 ppp->xc_state = state;
2272 ppp_xmit_unlock(ppp);
2273 if (ostate) {
2274 ocomp->comp_free(ostate);
2275 module_put(ocomp->owner);
2276 }
2277 err = 0;
2278 } else
2279 module_put(cp->owner);
2280
2281 } else {
2282 state = cp->decomp_alloc(ccp_option, data.length);
2283 if (state) {
2284 ppp_recv_lock(ppp);
2285 ppp->rstate &= ~SC_DECOMP_RUN;
2286 ocomp = ppp->rcomp;
2287 ostate = ppp->rc_state;
2288 ppp->rcomp = cp;
2289 ppp->rc_state = state;
2290 ppp_recv_unlock(ppp);
2291 if (ostate) {
2292 ocomp->decomp_free(ostate);
2293 module_put(ocomp->owner);
2294 }
2295 err = 0;
2296 } else
2297 module_put(cp->owner);
2298 }
2299
2300 out:
2301 return err;
2302 }
2303
2304 /*
2305 * Look at a CCP packet and update our state accordingly.
2306 * We assume the caller has the xmit or recv path locked.
2307 */
2308 static void
2309 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2310 {
2311 unsigned char *dp;
2312 int len;
2313
2314 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2315 return; /* no header */
2316 dp = skb->data + 2;
2317
2318 switch (CCP_CODE(dp)) {
2319 case CCP_CONFREQ:
2320
2321 /* A ConfReq starts negotiation of compression
2322 * in one direction of transmission,
2323 * and hence brings it down...but which way?
2324 *
2325 * Remember:
2326 * A ConfReq indicates what the sender would like to receive
2327 */
2328 if(inbound)
2329 /* He is proposing what I should send */
2330 ppp->xstate &= ~SC_COMP_RUN;
2331 else
2332 /* I am proposing to what he should send */
2333 ppp->rstate &= ~SC_DECOMP_RUN;
2334
2335 break;
2336
2337 case CCP_TERMREQ:
2338 case CCP_TERMACK:
2339 /*
2340 * CCP is going down, both directions of transmission
2341 */
2342 ppp->rstate &= ~SC_DECOMP_RUN;
2343 ppp->xstate &= ~SC_COMP_RUN;
2344 break;
2345
2346 case CCP_CONFACK:
2347 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2348 break;
2349 len = CCP_LENGTH(dp);
2350 if (!pskb_may_pull(skb, len + 2))
2351 return; /* too short */
2352 dp += CCP_HDRLEN;
2353 len -= CCP_HDRLEN;
2354 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2355 break;
2356 if (inbound) {
2357 /* we will start receiving compressed packets */
2358 if (!ppp->rc_state)
2359 break;
2360 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2361 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2362 ppp->rstate |= SC_DECOMP_RUN;
2363 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2364 }
2365 } else {
2366 /* we will soon start sending compressed packets */
2367 if (!ppp->xc_state)
2368 break;
2369 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2370 ppp->file.index, 0, ppp->debug))
2371 ppp->xstate |= SC_COMP_RUN;
2372 }
2373 break;
2374
2375 case CCP_RESETACK:
2376 /* reset the [de]compressor */
2377 if ((ppp->flags & SC_CCP_UP) == 0)
2378 break;
2379 if (inbound) {
2380 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2381 ppp->rcomp->decomp_reset(ppp->rc_state);
2382 ppp->rstate &= ~SC_DC_ERROR;
2383 }
2384 } else {
2385 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2386 ppp->xcomp->comp_reset(ppp->xc_state);
2387 }
2388 break;
2389 }
2390 }
2391
2392 /* Free up compression resources. */
2393 static void
2394 ppp_ccp_closed(struct ppp *ppp)
2395 {
2396 void *xstate, *rstate;
2397 struct compressor *xcomp, *rcomp;
2398
2399 ppp_lock(ppp);
2400 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2401 ppp->xstate = 0;
2402 xcomp = ppp->xcomp;
2403 xstate = ppp->xc_state;
2404 ppp->xc_state = NULL;
2405 ppp->rstate = 0;
2406 rcomp = ppp->rcomp;
2407 rstate = ppp->rc_state;
2408 ppp->rc_state = NULL;
2409 ppp_unlock(ppp);
2410
2411 if (xstate) {
2412 xcomp->comp_free(xstate);
2413 module_put(xcomp->owner);
2414 }
2415 if (rstate) {
2416 rcomp->decomp_free(rstate);
2417 module_put(rcomp->owner);
2418 }
2419 }
2420
2421 /* List of compressors. */
2422 static LIST_HEAD(compressor_list);
2423 static DEFINE_SPINLOCK(compressor_list_lock);
2424
2425 struct compressor_entry {
2426 struct list_head list;
2427 struct compressor *comp;
2428 };
2429
2430 static struct compressor_entry *
2431 find_comp_entry(int proto)
2432 {
2433 struct compressor_entry *ce;
2434
2435 list_for_each_entry(ce, &compressor_list, list) {
2436 if (ce->comp->compress_proto == proto)
2437 return ce;
2438 }
2439 return NULL;
2440 }
2441
2442 /* Register a compressor */
2443 int
2444 ppp_register_compressor(struct compressor *cp)
2445 {
2446 struct compressor_entry *ce;
2447 int ret;
2448 spin_lock(&compressor_list_lock);
2449 ret = -EEXIST;
2450 if (find_comp_entry(cp->compress_proto))
2451 goto out;
2452 ret = -ENOMEM;
2453 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2454 if (!ce)
2455 goto out;
2456 ret = 0;
2457 ce->comp = cp;
2458 list_add(&ce->list, &compressor_list);
2459 out:
2460 spin_unlock(&compressor_list_lock);
2461 return ret;
2462 }
2463
2464 /* Unregister a compressor */
2465 void
2466 ppp_unregister_compressor(struct compressor *cp)
2467 {
2468 struct compressor_entry *ce;
2469
2470 spin_lock(&compressor_list_lock);
2471 ce = find_comp_entry(cp->compress_proto);
2472 if (ce && ce->comp == cp) {
2473 list_del(&ce->list);
2474 kfree(ce);
2475 }
2476 spin_unlock(&compressor_list_lock);
2477 }
2478
2479 /* Find a compressor. */
2480 static struct compressor *
2481 find_compressor(int type)
2482 {
2483 struct compressor_entry *ce;
2484 struct compressor *cp = NULL;
2485
2486 spin_lock(&compressor_list_lock);
2487 ce = find_comp_entry(type);
2488 if (ce) {
2489 cp = ce->comp;
2490 if (!try_module_get(cp->owner))
2491 cp = NULL;
2492 }
2493 spin_unlock(&compressor_list_lock);
2494 return cp;
2495 }
2496
2497 /*
2498 * Miscelleneous stuff.
2499 */
2500
2501 static void
2502 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2503 {
2504 struct slcompress *vj = ppp->vj;
2505
2506 memset(st, 0, sizeof(*st));
2507 st->p.ppp_ipackets = ppp->dev->stats.rx_packets;
2508 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2509 st->p.ppp_ibytes = ppp->dev->stats.rx_bytes;
2510 st->p.ppp_opackets = ppp->dev->stats.tx_packets;
2511 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2512 st->p.ppp_obytes = ppp->dev->stats.tx_bytes;
2513 if (!vj)
2514 return;
2515 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2516 st->vj.vjs_compressed = vj->sls_o_compressed;
2517 st->vj.vjs_searches = vj->sls_o_searches;
2518 st->vj.vjs_misses = vj->sls_o_misses;
2519 st->vj.vjs_errorin = vj->sls_i_error;
2520 st->vj.vjs_tossed = vj->sls_i_tossed;
2521 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2522 st->vj.vjs_compressedin = vj->sls_i_compressed;
2523 }
2524
2525 /*
2526 * Stuff for handling the lists of ppp units and channels
2527 * and for initialization.
2528 */
2529
2530 /*
2531 * Create a new ppp interface unit. Fails if it can't allocate memory
2532 * or if there is already a unit with the requested number.
2533 * unit == -1 means allocate a new number.
2534 */
2535 static struct ppp *
2536 ppp_create_interface(struct net *net, int unit, int *retp)
2537 {
2538 struct ppp *ppp;
2539 struct ppp_net *pn;
2540 struct net_device *dev = NULL;
2541 int ret = -ENOMEM;
2542 int i;
2543
2544 dev = alloc_netdev(sizeof(struct ppp), "", ppp_setup);
2545 if (!dev)
2546 goto out1;
2547
2548 pn = ppp_pernet(net);
2549
2550 ppp = netdev_priv(dev);
2551 ppp->dev = dev;
2552 ppp->mru = PPP_MRU;
2553 init_ppp_file(&ppp->file, INTERFACE);
2554 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2555 for (i = 0; i < NUM_NP; ++i)
2556 ppp->npmode[i] = NPMODE_PASS;
2557 INIT_LIST_HEAD(&ppp->channels);
2558 spin_lock_init(&ppp->rlock);
2559 spin_lock_init(&ppp->wlock);
2560 #ifdef CONFIG_PPP_MULTILINK
2561 ppp->minseq = -1;
2562 skb_queue_head_init(&ppp->mrq);
2563 #endif /* CONFIG_PPP_MULTILINK */
2564
2565 /*
2566 * drum roll: don't forget to set
2567 * the net device is belong to
2568 */
2569 dev_net_set(dev, net);
2570
2571 ret = -EEXIST;
2572 mutex_lock(&pn->all_ppp_mutex);
2573
2574 if (unit < 0) {
2575 unit = unit_get(&pn->units_idr, ppp);
2576 if (unit < 0) {
2577 *retp = unit;
2578 goto out2;
2579 }
2580 } else {
2581 if (unit_find(&pn->units_idr, unit))
2582 goto out2; /* unit already exists */
2583 /*
2584 * if caller need a specified unit number
2585 * lets try to satisfy him, otherwise --
2586 * he should better ask us for new unit number
2587 *
2588 * NOTE: yes I know that returning EEXIST it's not
2589 * fair but at least pppd will ask us to allocate
2590 * new unit in this case so user is happy :)
2591 */
2592 unit = unit_set(&pn->units_idr, ppp, unit);
2593 if (unit < 0)
2594 goto out2;
2595 }
2596
2597 /* Initialize the new ppp unit */
2598 ppp->file.index = unit;
2599 sprintf(dev->name, "ppp%d", unit);
2600
2601 ret = register_netdev(dev);
2602 if (ret != 0) {
2603 unit_put(&pn->units_idr, unit);
2604 printk(KERN_ERR "PPP: couldn't register device %s (%d)\n",
2605 dev->name, ret);
2606 goto out2;
2607 }
2608
2609 ppp->ppp_net = net;
2610
2611 atomic_inc(&ppp_unit_count);
2612 mutex_unlock(&pn->all_ppp_mutex);
2613
2614 *retp = 0;
2615 return ppp;
2616
2617 out2:
2618 mutex_unlock(&pn->all_ppp_mutex);
2619 free_netdev(dev);
2620 out1:
2621 *retp = ret;
2622 return NULL;
2623 }
2624
2625 /*
2626 * Initialize a ppp_file structure.
2627 */
2628 static void
2629 init_ppp_file(struct ppp_file *pf, int kind)
2630 {
2631 pf->kind = kind;
2632 skb_queue_head_init(&pf->xq);
2633 skb_queue_head_init(&pf->rq);
2634 atomic_set(&pf->refcnt, 1);
2635 init_waitqueue_head(&pf->rwait);
2636 }
2637
2638 /*
2639 * Take down a ppp interface unit - called when the owning file
2640 * (the one that created the unit) is closed or detached.
2641 */
2642 static void ppp_shutdown_interface(struct ppp *ppp)
2643 {
2644 struct ppp_net *pn;
2645
2646 pn = ppp_pernet(ppp->ppp_net);
2647 mutex_lock(&pn->all_ppp_mutex);
2648
2649 /* This will call dev_close() for us. */
2650 ppp_lock(ppp);
2651 if (!ppp->closing) {
2652 ppp->closing = 1;
2653 ppp_unlock(ppp);
2654 unregister_netdev(ppp->dev);
2655 } else
2656 ppp_unlock(ppp);
2657
2658 unit_put(&pn->units_idr, ppp->file.index);
2659 ppp->file.dead = 1;
2660 ppp->owner = NULL;
2661 wake_up_interruptible(&ppp->file.rwait);
2662
2663 mutex_unlock(&pn->all_ppp_mutex);
2664 }
2665
2666 /*
2667 * Free the memory used by a ppp unit. This is only called once
2668 * there are no channels connected to the unit and no file structs
2669 * that reference the unit.
2670 */
2671 static void ppp_destroy_interface(struct ppp *ppp)
2672 {
2673 atomic_dec(&ppp_unit_count);
2674
2675 if (!ppp->file.dead || ppp->n_channels) {
2676 /* "can't happen" */
2677 printk(KERN_ERR "ppp: destroying ppp struct %p but dead=%d "
2678 "n_channels=%d !\n", ppp, ppp->file.dead,
2679 ppp->n_channels);
2680 return;
2681 }
2682
2683 ppp_ccp_closed(ppp);
2684 if (ppp->vj) {
2685 slhc_free(ppp->vj);
2686 ppp->vj = NULL;
2687 }
2688 skb_queue_purge(&ppp->file.xq);
2689 skb_queue_purge(&ppp->file.rq);
2690 #ifdef CONFIG_PPP_MULTILINK
2691 skb_queue_purge(&ppp->mrq);
2692 #endif /* CONFIG_PPP_MULTILINK */
2693 #ifdef CONFIG_PPP_FILTER
2694 kfree(ppp->pass_filter);
2695 ppp->pass_filter = NULL;
2696 kfree(ppp->active_filter);
2697 ppp->active_filter = NULL;
2698 #endif /* CONFIG_PPP_FILTER */
2699
2700 kfree_skb(ppp->xmit_pending);
2701
2702 free_netdev(ppp->dev);
2703 }
2704
2705 /*
2706 * Locate an existing ppp unit.
2707 * The caller should have locked the all_ppp_mutex.
2708 */
2709 static struct ppp *
2710 ppp_find_unit(struct ppp_net *pn, int unit)
2711 {
2712 return unit_find(&pn->units_idr, unit);
2713 }
2714
2715 /*
2716 * Locate an existing ppp channel.
2717 * The caller should have locked the all_channels_lock.
2718 * First we look in the new_channels list, then in the
2719 * all_channels list. If found in the new_channels list,
2720 * we move it to the all_channels list. This is for speed
2721 * when we have a lot of channels in use.
2722 */
2723 static struct channel *
2724 ppp_find_channel(struct ppp_net *pn, int unit)
2725 {
2726 struct channel *pch;
2727
2728 list_for_each_entry(pch, &pn->new_channels, list) {
2729 if (pch->file.index == unit) {
2730 list_move(&pch->list, &pn->all_channels);
2731 return pch;
2732 }
2733 }
2734
2735 list_for_each_entry(pch, &pn->all_channels, list) {
2736 if (pch->file.index == unit)
2737 return pch;
2738 }
2739
2740 return NULL;
2741 }
2742
2743 /*
2744 * Connect a PPP channel to a PPP interface unit.
2745 */
2746 static int
2747 ppp_connect_channel(struct channel *pch, int unit)
2748 {
2749 struct ppp *ppp;
2750 struct ppp_net *pn;
2751 int ret = -ENXIO;
2752 int hdrlen;
2753
2754 pn = ppp_pernet(pch->chan_net);
2755
2756 mutex_lock(&pn->all_ppp_mutex);
2757 ppp = ppp_find_unit(pn, unit);
2758 if (!ppp)
2759 goto out;
2760 write_lock_bh(&pch->upl);
2761 ret = -EINVAL;
2762 if (pch->ppp)
2763 goto outl;
2764
2765 ppp_lock(ppp);
2766 if (pch->file.hdrlen > ppp->file.hdrlen)
2767 ppp->file.hdrlen = pch->file.hdrlen;
2768 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2769 if (hdrlen > ppp->dev->hard_header_len)
2770 ppp->dev->hard_header_len = hdrlen;
2771 list_add_tail(&pch->clist, &ppp->channels);
2772 ++ppp->n_channels;
2773 pch->ppp = ppp;
2774 atomic_inc(&ppp->file.refcnt);
2775 ppp_unlock(ppp);
2776 ret = 0;
2777
2778 outl:
2779 write_unlock_bh(&pch->upl);
2780 out:
2781 mutex_unlock(&pn->all_ppp_mutex);
2782 return ret;
2783 }
2784
2785 /*
2786 * Disconnect a channel from its ppp unit.
2787 */
2788 static int
2789 ppp_disconnect_channel(struct channel *pch)
2790 {
2791 struct ppp *ppp;
2792 int err = -EINVAL;
2793
2794 write_lock_bh(&pch->upl);
2795 ppp = pch->ppp;
2796 pch->ppp = NULL;
2797 write_unlock_bh(&pch->upl);
2798 if (ppp) {
2799 /* remove it from the ppp unit's list */
2800 ppp_lock(ppp);
2801 list_del(&pch->clist);
2802 if (--ppp->n_channels == 0)
2803 wake_up_interruptible(&ppp->file.rwait);
2804 ppp_unlock(ppp);
2805 if (atomic_dec_and_test(&ppp->file.refcnt))
2806 ppp_destroy_interface(ppp);
2807 err = 0;
2808 }
2809 return err;
2810 }
2811
2812 /*
2813 * Free up the resources used by a ppp channel.
2814 */
2815 static void ppp_destroy_channel(struct channel *pch)
2816 {
2817 atomic_dec(&channel_count);
2818
2819 if (!pch->file.dead) {
2820 /* "can't happen" */
2821 printk(KERN_ERR "ppp: destroying undead channel %p !\n",
2822 pch);
2823 return;
2824 }
2825 skb_queue_purge(&pch->file.xq);
2826 skb_queue_purge(&pch->file.rq);
2827 kfree(pch);
2828 }
2829
2830 static void __exit ppp_cleanup(void)
2831 {
2832 /* should never happen */
2833 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2834 printk(KERN_ERR "PPP: removing module but units remain!\n");
2835 unregister_chrdev(PPP_MAJOR, "ppp");
2836 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
2837 class_destroy(ppp_class);
2838 unregister_pernet_gen_device(ppp_net_id, &ppp_net_ops);
2839 }
2840
2841 /*
2842 * Units handling. Caller must protect concurrent access
2843 * by holding all_ppp_mutex
2844 */
2845
2846 /* associate pointer with specified number */
2847 static int unit_set(struct idr *p, void *ptr, int n)
2848 {
2849 int unit, err;
2850
2851 again:
2852 if (!idr_pre_get(p, GFP_KERNEL)) {
2853 printk(KERN_ERR "PPP: No free memory for idr\n");
2854 return -ENOMEM;
2855 }
2856
2857 err = idr_get_new_above(p, ptr, n, &unit);
2858 if (err == -EAGAIN)
2859 goto again;
2860
2861 if (unit != n) {
2862 idr_remove(p, unit);
2863 return -EINVAL;
2864 }
2865
2866 return unit;
2867 }
2868
2869 /* get new free unit number and associate pointer with it */
2870 static int unit_get(struct idr *p, void *ptr)
2871 {
2872 int unit, err;
2873
2874 again:
2875 if (!idr_pre_get(p, GFP_KERNEL)) {
2876 printk(KERN_ERR "PPP: No free memory for idr\n");
2877 return -ENOMEM;
2878 }
2879
2880 err = idr_get_new_above(p, ptr, 0, &unit);
2881 if (err == -EAGAIN)
2882 goto again;
2883
2884 return unit;
2885 }
2886
2887 /* put unit number back to a pool */
2888 static void unit_put(struct idr *p, int n)
2889 {
2890 idr_remove(p, n);
2891 }
2892
2893 /* get pointer associated with the number */
2894 static void *unit_find(struct idr *p, int n)
2895 {
2896 return idr_find(p, n);
2897 }
2898
2899 /* Module/initialization stuff */
2900
2901 module_init(ppp_init);
2902 module_exit(ppp_cleanup);
2903
2904 EXPORT_SYMBOL(ppp_register_net_channel);
2905 EXPORT_SYMBOL(ppp_register_channel);
2906 EXPORT_SYMBOL(ppp_unregister_channel);
2907 EXPORT_SYMBOL(ppp_channel_index);
2908 EXPORT_SYMBOL(ppp_unit_number);
2909 EXPORT_SYMBOL(ppp_input);
2910 EXPORT_SYMBOL(ppp_input_error);
2911 EXPORT_SYMBOL(ppp_output_wakeup);
2912 EXPORT_SYMBOL(ppp_register_compressor);
2913 EXPORT_SYMBOL(ppp_unregister_compressor);
2914 MODULE_LICENSE("GPL");
2915 MODULE_ALIAS_CHARDEV_MAJOR(PPP_MAJOR);
2916 MODULE_ALIAS("/dev/ppp");
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree