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net: ppp_generic - use DEFINE_IDR for static initialization
[linux-2.6/mini2440.git] / drivers / net / ppp_generic.c
blobc832d600d1e8829b72faddd095dfa513e03d03e0
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 #define PPP_VERSION "2.4.2"
53
54 /*
55 * Network protocols we support.
56 */
57 #define NP_IP 0 /* Internet Protocol V4 */
58 #define NP_IPV6 1 /* Internet Protocol V6 */
59 #define NP_IPX 2 /* IPX protocol */
60 #define NP_AT 3 /* Appletalk protocol */
61 #define NP_MPLS_UC 4 /* MPLS unicast */
62 #define NP_MPLS_MC 5 /* MPLS multicast */
63 #define NUM_NP 6 /* Number of NPs. */
64
65 #define MPHDRLEN 6 /* multilink protocol header length */
66 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */
67 #define MIN_FRAG_SIZE 64
68
69 /*
70 * An instance of /dev/ppp can be associated with either a ppp
71 * interface unit or a ppp channel. In both cases, file->private_data
72 * points to one of these.
73 */
74 struct ppp_file {
75 enum {
76 INTERFACE=1, CHANNEL
77 } kind;
78 struct sk_buff_head xq; /* pppd transmit queue */
79 struct sk_buff_head rq; /* receive queue for pppd */
80 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */
81 atomic_t refcnt; /* # refs (incl /dev/ppp attached) */
82 int hdrlen; /* space to leave for headers */
83 int index; /* interface unit / channel number */
84 int dead; /* unit/channel has been shut down */
85 };
86
87 #define PF_TO_X(pf, X) container_of(pf, X, file)
88
89 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
90 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
91
92 /*
93 * Data structure describing one ppp unit.
94 * A ppp unit corresponds to a ppp network interface device
95 * and represents a multilink bundle.
96 * It can have 0 or more ppp channels connected to it.
97 */
98 struct ppp {
99 struct ppp_file file; /* stuff for read/write/poll 0 */
100 struct file *owner; /* file that owns this unit 48 */
101 struct list_head channels; /* list of attached channels 4c */
102 int n_channels; /* how many channels are attached 54 */
103 spinlock_t rlock; /* lock for receive side 58 */
104 spinlock_t wlock; /* lock for transmit side 5c */
105 int mru; /* max receive unit 60 */
106 unsigned int flags; /* control bits 64 */
107 unsigned int xstate; /* transmit state bits 68 */
108 unsigned int rstate; /* receive state bits 6c */
109 int debug; /* debug flags 70 */
110 struct slcompress *vj; /* state for VJ header compression */
111 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
112 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
113 struct compressor *xcomp; /* transmit packet compressor 8c */
114 void *xc_state; /* its internal state 90 */
115 struct compressor *rcomp; /* receive decompressor 94 */
116 void *rc_state; /* its internal state 98 */
117 unsigned long last_xmit; /* jiffies when last pkt sent 9c */
118 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
119 struct net_device *dev; /* network interface device a4 */
120 #ifdef CONFIG_PPP_MULTILINK
121 int nxchan; /* next channel to send something on */
122 u32 nxseq; /* next sequence number to send */
123 int mrru; /* MP: max reconst. receive unit */
124 u32 nextseq; /* MP: seq no of next packet */
125 u32 minseq; /* MP: min of most recent seqnos */
126 struct sk_buff_head mrq; /* MP: receive reconstruction queue */
127 #endif /* CONFIG_PPP_MULTILINK */
128 #ifdef CONFIG_PPP_FILTER
129 struct sock_filter *pass_filter; /* filter for packets to pass */
130 struct sock_filter *active_filter;/* filter for pkts to reset idle */
131 unsigned pass_len, active_len;
132 #endif /* CONFIG_PPP_FILTER */
133 };
134
135 /*
136 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
137 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
138 * SC_MUST_COMP
139 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
140 * Bits in xstate: SC_COMP_RUN
141 */
142 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
143 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
144 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
145
146 /*
147 * Private data structure for each channel.
148 * This includes the data structure used for multilink.
149 */
150 struct channel {
151 struct ppp_file file; /* stuff for read/write/poll */
152 struct list_head list; /* link in all/new_channels list */
153 struct ppp_channel *chan; /* public channel data structure */
154 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
155 spinlock_t downl; /* protects `chan', file.xq dequeue */
156 struct ppp *ppp; /* ppp unit we're connected to */
157 struct list_head clist; /* link in list of channels per unit */
158 rwlock_t upl; /* protects `ppp' */
159 #ifdef CONFIG_PPP_MULTILINK
160 u8 avail; /* flag used in multilink stuff */
161 u8 had_frag; /* >= 1 fragments have been sent */
162 u32 lastseq; /* MP: last sequence # received */
163 #endif /* CONFIG_PPP_MULTILINK */
164 };
165
166 /*
167 * SMP locking issues:
168 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
169 * list and the ppp.n_channels field, you need to take both locks
170 * before you modify them.
171 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
172 * channel.downl.
173 */
174
175 /*
176 * all_ppp_mutex protects the all_ppp_units mapping.
177 * It also ensures that finding a ppp unit in the all_ppp_units map
178 * and updating its file.refcnt field is atomic.
179 */
180 static DEFINE_MUTEX(all_ppp_mutex);
181 static atomic_t ppp_unit_count = ATOMIC_INIT(0);
182 static DEFINE_IDR(ppp_units_idr);
183
184 /*
185 * all_channels_lock protects all_channels and last_channel_index,
186 * and the atomicity of find a channel and updating its file.refcnt
187 * field.
188 */
189 static DEFINE_SPINLOCK(all_channels_lock);
190 static LIST_HEAD(all_channels);
191 static LIST_HEAD(new_channels);
192 static int last_channel_index;
193 static atomic_t channel_count = ATOMIC_INIT(0);
194
195 /* Get the PPP protocol number from a skb */
196 #define PPP_PROTO(skb) (((skb)->data[0] << 8) + (skb)->data[1])
197
198 /* We limit the length of ppp->file.rq to this (arbitrary) value */
199 #define PPP_MAX_RQLEN 32
200
201 /*
202 * Maximum number of multilink fragments queued up.
203 * This has to be large enough to cope with the maximum latency of
204 * the slowest channel relative to the others. Strictly it should
205 * depend on the number of channels and their characteristics.
206 */
207 #define PPP_MP_MAX_QLEN 128
208
209 /* Multilink header bits. */
210 #define B 0x80 /* this fragment begins a packet */
211 #define E 0x40 /* this fragment ends a packet */
212
213 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */
214 #define seq_before(a, b) ((s32)((a) - (b)) < 0)
215 #define seq_after(a, b) ((s32)((a) - (b)) > 0)
216
217 /* Prototypes. */
218 static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file,
219 unsigned int cmd, unsigned long arg);
220 static void ppp_xmit_process(struct ppp *ppp);
221 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
222 static void ppp_push(struct ppp *ppp);
223 static void ppp_channel_push(struct channel *pch);
224 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
225 struct channel *pch);
226 static void ppp_receive_error(struct ppp *ppp);
227 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
228 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
229 struct sk_buff *skb);
230 #ifdef CONFIG_PPP_MULTILINK
231 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
232 struct channel *pch);
233 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
234 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
235 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
236 #endif /* CONFIG_PPP_MULTILINK */
237 static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
238 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
239 static void ppp_ccp_closed(struct ppp *ppp);
240 static struct compressor *find_compressor(int type);
241 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
242 static struct ppp *ppp_create_interface(int unit, int *retp);
243 static void init_ppp_file(struct ppp_file *pf, int kind);
244 static void ppp_shutdown_interface(struct ppp *ppp);
245 static void ppp_destroy_interface(struct ppp *ppp);
246 static struct ppp *ppp_find_unit(int unit);
247 static struct channel *ppp_find_channel(int unit);
248 static int ppp_connect_channel(struct channel *pch, int unit);
249 static int ppp_disconnect_channel(struct channel *pch);
250 static void ppp_destroy_channel(struct channel *pch);
251 static int unit_get(struct idr *p, void *ptr);
252 static void unit_put(struct idr *p, int n);
253 static void *unit_find(struct idr *p, int n);
254
255 static struct class *ppp_class;
256
257 /* Translates a PPP protocol number to a NP index (NP == network protocol) */
258 static inline int proto_to_npindex(int proto)
259 {
260 switch (proto) {
261 case PPP_IP:
262 return NP_IP;
263 case PPP_IPV6:
264 return NP_IPV6;
265 case PPP_IPX:
266 return NP_IPX;
267 case PPP_AT:
268 return NP_AT;
269 case PPP_MPLS_UC:
270 return NP_MPLS_UC;
271 case PPP_MPLS_MC:
272 return NP_MPLS_MC;
273 }
274 return -EINVAL;
275 }
276
277 /* Translates an NP index into a PPP protocol number */
278 static const int npindex_to_proto[NUM_NP] = {
279 PPP_IP,
280 PPP_IPV6,
281 PPP_IPX,
282 PPP_AT,
283 PPP_MPLS_UC,
284 PPP_MPLS_MC,
285 };
286
287 /* Translates an ethertype into an NP index */
288 static inline int ethertype_to_npindex(int ethertype)
289 {
290 switch (ethertype) {
291 case ETH_P_IP:
292 return NP_IP;
293 case ETH_P_IPV6:
294 return NP_IPV6;
295 case ETH_P_IPX:
296 return NP_IPX;
297 case ETH_P_PPPTALK:
298 case ETH_P_ATALK:
299 return NP_AT;
300 case ETH_P_MPLS_UC:
301 return NP_MPLS_UC;
302 case ETH_P_MPLS_MC:
303 return NP_MPLS_MC;
304 }
305 return -1;
306 }
307
308 /* Translates an NP index into an ethertype */
309 static const int npindex_to_ethertype[NUM_NP] = {
310 ETH_P_IP,
311 ETH_P_IPV6,
312 ETH_P_IPX,
313 ETH_P_PPPTALK,
314 ETH_P_MPLS_UC,
315 ETH_P_MPLS_MC,
316 };
317
318 /*
319 * Locking shorthand.
320 */
321 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
322 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
323 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
324 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
325 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
326 ppp_recv_lock(ppp); } while (0)
327 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
328 ppp_xmit_unlock(ppp); } while (0)
329
330 /*
331 * /dev/ppp device routines.
332 * The /dev/ppp device is used by pppd to control the ppp unit.
333 * It supports the read, write, ioctl and poll functions.
334 * Open instances of /dev/ppp can be in one of three states:
335 * unattached, attached to a ppp unit, or attached to a ppp channel.
336 */
337 static int ppp_open(struct inode *inode, struct file *file)
338 {
339 cycle_kernel_lock();
340 /*
341 * This could (should?) be enforced by the permissions on /dev/ppp.
342 */
343 if (!capable(CAP_NET_ADMIN))
344 return -EPERM;
345 return 0;
346 }
347
348 static int ppp_release(struct inode *unused, struct file *file)
349 {
350 struct ppp_file *pf = file->private_data;
351 struct ppp *ppp;
352
353 if (pf) {
354 file->private_data = NULL;
355 if (pf->kind == INTERFACE) {
356 ppp = PF_TO_PPP(pf);
357 if (file == ppp->owner)
358 ppp_shutdown_interface(ppp);
359 }
360 if (atomic_dec_and_test(&pf->refcnt)) {
361 switch (pf->kind) {
362 case INTERFACE:
363 ppp_destroy_interface(PF_TO_PPP(pf));
364 break;
365 case CHANNEL:
366 ppp_destroy_channel(PF_TO_CHANNEL(pf));
367 break;
368 }
369 }
370 }
371 return 0;
372 }
373
374 static ssize_t ppp_read(struct file *file, char __user *buf,
375 size_t count, loff_t *ppos)
376 {
377 struct ppp_file *pf = file->private_data;
378 DECLARE_WAITQUEUE(wait, current);
379 ssize_t ret;
380 struct sk_buff *skb = NULL;
381
382 ret = count;
383
384 if (!pf)
385 return -ENXIO;
386 add_wait_queue(&pf->rwait, &wait);
387 for (;;) {
388 set_current_state(TASK_INTERRUPTIBLE);
389 skb = skb_dequeue(&pf->rq);
390 if (skb)
391 break;
392 ret = 0;
393 if (pf->dead)
394 break;
395 if (pf->kind == INTERFACE) {
396 /*
397 * Return 0 (EOF) on an interface that has no
398 * channels connected, unless it is looping
399 * network traffic (demand mode).
400 */
401 struct ppp *ppp = PF_TO_PPP(pf);
402 if (ppp->n_channels == 0
403 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
404 break;
405 }
406 ret = -EAGAIN;
407 if (file->f_flags & O_NONBLOCK)
408 break;
409 ret = -ERESTARTSYS;
410 if (signal_pending(current))
411 break;
412 schedule();
413 }
414 set_current_state(TASK_RUNNING);
415 remove_wait_queue(&pf->rwait, &wait);
416
417 if (!skb)
418 goto out;
419
420 ret = -EOVERFLOW;
421 if (skb->len > count)
422 goto outf;
423 ret = -EFAULT;
424 if (copy_to_user(buf, skb->data, skb->len))
425 goto outf;
426 ret = skb->len;
427
428 outf:
429 kfree_skb(skb);
430 out:
431 return ret;
432 }
433
434 static ssize_t ppp_write(struct file *file, const char __user *buf,
435 size_t count, loff_t *ppos)
436 {
437 struct ppp_file *pf = file->private_data;
438 struct sk_buff *skb;
439 ssize_t ret;
440
441 if (!pf)
442 return -ENXIO;
443 ret = -ENOMEM;
444 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
445 if (!skb)
446 goto out;
447 skb_reserve(skb, pf->hdrlen);
448 ret = -EFAULT;
449 if (copy_from_user(skb_put(skb, count), buf, count)) {
450 kfree_skb(skb);
451 goto out;
452 }
453
454 skb_queue_tail(&pf->xq, skb);
455
456 switch (pf->kind) {
457 case INTERFACE:
458 ppp_xmit_process(PF_TO_PPP(pf));
459 break;
460 case CHANNEL:
461 ppp_channel_push(PF_TO_CHANNEL(pf));
462 break;
463 }
464
465 ret = count;
466
467 out:
468 return ret;
469 }
470
471 /* No kernel lock - fine */
472 static unsigned int ppp_poll(struct file *file, poll_table *wait)
473 {
474 struct ppp_file *pf = file->private_data;
475 unsigned int mask;
476
477 if (!pf)
478 return 0;
479 poll_wait(file, &pf->rwait, wait);
480 mask = POLLOUT | POLLWRNORM;
481 if (skb_peek(&pf->rq))
482 mask |= POLLIN | POLLRDNORM;
483 if (pf->dead)
484 mask |= POLLHUP;
485 else if (pf->kind == INTERFACE) {
486 /* see comment in ppp_read */
487 struct ppp *ppp = PF_TO_PPP(pf);
488 if (ppp->n_channels == 0
489 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
490 mask |= POLLIN | POLLRDNORM;
491 }
492
493 return mask;
494 }
495
496 #ifdef CONFIG_PPP_FILTER
497 static int get_filter(void __user *arg, struct sock_filter **p)
498 {
499 struct sock_fprog uprog;
500 struct sock_filter *code = NULL;
501 int len, err;
502
503 if (copy_from_user(&uprog, arg, sizeof(uprog)))
504 return -EFAULT;
505
506 if (!uprog.len) {
507 *p = NULL;
508 return 0;
509 }
510
511 len = uprog.len * sizeof(struct sock_filter);
512 code = kmalloc(len, GFP_KERNEL);
513 if (code == NULL)
514 return -ENOMEM;
515
516 if (copy_from_user(code, uprog.filter, len)) {
517 kfree(code);
518 return -EFAULT;
519 }
520
521 err = sk_chk_filter(code, uprog.len);
522 if (err) {
523 kfree(code);
524 return err;
525 }
526
527 *p = code;
528 return uprog.len;
529 }
530 #endif /* CONFIG_PPP_FILTER */
531
532 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
533 {
534 struct ppp_file *pf = file->private_data;
535 struct ppp *ppp;
536 int err = -EFAULT, val, val2, i;
537 struct ppp_idle idle;
538 struct npioctl npi;
539 int unit, cflags;
540 struct slcompress *vj;
541 void __user *argp = (void __user *)arg;
542 int __user *p = argp;
543
544 if (!pf)
545 return ppp_unattached_ioctl(pf, file, cmd, arg);
546
547 if (cmd == PPPIOCDETACH) {
548 /*
549 * We have to be careful here... if the file descriptor
550 * has been dup'd, we could have another process in the
551 * middle of a poll using the same file *, so we had
552 * better not free the interface data structures -
553 * instead we fail the ioctl. Even in this case, we
554 * shut down the interface if we are the owner of it.
555 * Actually, we should get rid of PPPIOCDETACH, userland
556 * (i.e. pppd) could achieve the same effect by closing
557 * this fd and reopening /dev/ppp.
558 */
559 err = -EINVAL;
560 lock_kernel();
561 if (pf->kind == INTERFACE) {
562 ppp = PF_TO_PPP(pf);
563 if (file == ppp->owner)
564 ppp_shutdown_interface(ppp);
565 }
566 if (atomic_long_read(&file->f_count) <= 2) {
567 ppp_release(NULL, file);
568 err = 0;
569 } else
570 printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%ld\n",
571 atomic_long_read(&file->f_count));
572 unlock_kernel();
573 return err;
574 }
575
576 if (pf->kind == CHANNEL) {
577 struct channel *pch;
578 struct ppp_channel *chan;
579
580 lock_kernel();
581 pch = PF_TO_CHANNEL(pf);
582
583 switch (cmd) {
584 case PPPIOCCONNECT:
585 if (get_user(unit, p))
586 break;
587 err = ppp_connect_channel(pch, unit);
588 break;
589
590 case PPPIOCDISCONN:
591 err = ppp_disconnect_channel(pch);
592 break;
593
594 default:
595 down_read(&pch->chan_sem);
596 chan = pch->chan;
597 err = -ENOTTY;
598 if (chan && chan->ops->ioctl)
599 err = chan->ops->ioctl(chan, cmd, arg);
600 up_read(&pch->chan_sem);
601 }
602 unlock_kernel();
603 return err;
604 }
605
606 if (pf->kind != INTERFACE) {
607 /* can't happen */
608 printk(KERN_ERR "PPP: not interface or channel??\n");
609 return -EINVAL;
610 }
611
612 lock_kernel();
613 ppp = PF_TO_PPP(pf);
614 switch (cmd) {
615 case PPPIOCSMRU:
616 if (get_user(val, p))
617 break;
618 ppp->mru = val;
619 err = 0;
620 break;
621
622 case PPPIOCSFLAGS:
623 if (get_user(val, p))
624 break;
625 ppp_lock(ppp);
626 cflags = ppp->flags & ~val;
627 ppp->flags = val & SC_FLAG_BITS;
628 ppp_unlock(ppp);
629 if (cflags & SC_CCP_OPEN)
630 ppp_ccp_closed(ppp);
631 err = 0;
632 break;
633
634 case PPPIOCGFLAGS:
635 val = ppp->flags | ppp->xstate | ppp->rstate;
636 if (put_user(val, p))
637 break;
638 err = 0;
639 break;
640
641 case PPPIOCSCOMPRESS:
642 err = ppp_set_compress(ppp, arg);
643 break;
644
645 case PPPIOCGUNIT:
646 if (put_user(ppp->file.index, p))
647 break;
648 err = 0;
649 break;
650
651 case PPPIOCSDEBUG:
652 if (get_user(val, p))
653 break;
654 ppp->debug = val;
655 err = 0;
656 break;
657
658 case PPPIOCGDEBUG:
659 if (put_user(ppp->debug, p))
660 break;
661 err = 0;
662 break;
663
664 case PPPIOCGIDLE:
665 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
666 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
667 if (copy_to_user(argp, &idle, sizeof(idle)))
668 break;
669 err = 0;
670 break;
671
672 case PPPIOCSMAXCID:
673 if (get_user(val, p))
674 break;
675 val2 = 15;
676 if ((val >> 16) != 0) {
677 val2 = val >> 16;
678 val &= 0xffff;
679 }
680 vj = slhc_init(val2+1, val+1);
681 if (!vj) {
682 printk(KERN_ERR "PPP: no memory (VJ compressor)\n");
683 err = -ENOMEM;
684 break;
685 }
686 ppp_lock(ppp);
687 if (ppp->vj)
688 slhc_free(ppp->vj);
689 ppp->vj = vj;
690 ppp_unlock(ppp);
691 err = 0;
692 break;
693
694 case PPPIOCGNPMODE:
695 case PPPIOCSNPMODE:
696 if (copy_from_user(&npi, argp, sizeof(npi)))
697 break;
698 err = proto_to_npindex(npi.protocol);
699 if (err < 0)
700 break;
701 i = err;
702 if (cmd == PPPIOCGNPMODE) {
703 err = -EFAULT;
704 npi.mode = ppp->npmode[i];
705 if (copy_to_user(argp, &npi, sizeof(npi)))
706 break;
707 } else {
708 ppp->npmode[i] = npi.mode;
709 /* we may be able to transmit more packets now (??) */
710 netif_wake_queue(ppp->dev);
711 }
712 err = 0;
713 break;
714
715 #ifdef CONFIG_PPP_FILTER
716 case PPPIOCSPASS:
717 {
718 struct sock_filter *code;
719 err = get_filter(argp, &code);
720 if (err >= 0) {
721 ppp_lock(ppp);
722 kfree(ppp->pass_filter);
723 ppp->pass_filter = code;
724 ppp->pass_len = err;
725 ppp_unlock(ppp);
726 err = 0;
727 }
728 break;
729 }
730 case PPPIOCSACTIVE:
731 {
732 struct sock_filter *code;
733 err = get_filter(argp, &code);
734 if (err >= 0) {
735 ppp_lock(ppp);
736 kfree(ppp->active_filter);
737 ppp->active_filter = code;
738 ppp->active_len = err;
739 ppp_unlock(ppp);
740 err = 0;
741 }
742 break;
743 }
744 #endif /* CONFIG_PPP_FILTER */
745
746 #ifdef CONFIG_PPP_MULTILINK
747 case PPPIOCSMRRU:
748 if (get_user(val, p))
749 break;
750 ppp_recv_lock(ppp);
751 ppp->mrru = val;
752 ppp_recv_unlock(ppp);
753 err = 0;
754 break;
755 #endif /* CONFIG_PPP_MULTILINK */
756
757 default:
758 err = -ENOTTY;
759 }
760 unlock_kernel();
761 return err;
762 }
763
764 static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file,
765 unsigned int cmd, unsigned long arg)
766 {
767 int unit, err = -EFAULT;
768 struct ppp *ppp;
769 struct channel *chan;
770 int __user *p = (int __user *)arg;
771
772 lock_kernel();
773 switch (cmd) {
774 case PPPIOCNEWUNIT:
775 /* Create a new ppp unit */
776 if (get_user(unit, p))
777 break;
778 ppp = ppp_create_interface(unit, &err);
779 if (!ppp)
780 break;
781 file->private_data = &ppp->file;
782 ppp->owner = file;
783 err = -EFAULT;
784 if (put_user(ppp->file.index, p))
785 break;
786 err = 0;
787 break;
788
789 case PPPIOCATTACH:
790 /* Attach to an existing ppp unit */
791 if (get_user(unit, p))
792 break;
793 mutex_lock(&all_ppp_mutex);
794 err = -ENXIO;
795 ppp = ppp_find_unit(unit);
796 if (ppp) {
797 atomic_inc(&ppp->file.refcnt);
798 file->private_data = &ppp->file;
799 err = 0;
800 }
801 mutex_unlock(&all_ppp_mutex);
802 break;
803
804 case PPPIOCATTCHAN:
805 if (get_user(unit, p))
806 break;
807 spin_lock_bh(&all_channels_lock);
808 err = -ENXIO;
809 chan = ppp_find_channel(unit);
810 if (chan) {
811 atomic_inc(&chan->file.refcnt);
812 file->private_data = &chan->file;
813 err = 0;
814 }
815 spin_unlock_bh(&all_channels_lock);
816 break;
817
818 default:
819 err = -ENOTTY;
820 }
821 unlock_kernel();
822 return err;
823 }
824
825 static const struct file_operations ppp_device_fops = {
826 .owner = THIS_MODULE,
827 .read = ppp_read,
828 .write = ppp_write,
829 .poll = ppp_poll,
830 .unlocked_ioctl = ppp_ioctl,
831 .open = ppp_open,
832 .release = ppp_release
833 };
834
835 #define PPP_MAJOR 108
836
837 /* Called at boot time if ppp is compiled into the kernel,
838 or at module load time (from init_module) if compiled as a module. */
839 static int __init ppp_init(void)
840 {
841 int err;
842
843 printk(KERN_INFO "PPP generic driver version " PPP_VERSION "\n");
844 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
845 if (!err) {
846 ppp_class = class_create(THIS_MODULE, "ppp");
847 if (IS_ERR(ppp_class)) {
848 err = PTR_ERR(ppp_class);
849 goto out_chrdev;
850 }
851 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL,
852 "ppp");
853 }
854
855 out:
856 if (err)
857 printk(KERN_ERR "failed to register PPP device (%d)\n", err);
858 return err;
859
860 out_chrdev:
861 unregister_chrdev(PPP_MAJOR, "ppp");
862 goto out;
863 }
864
865 /*
866 * Network interface unit routines.
867 */
868 static int
869 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
870 {
871 struct ppp *ppp = netdev_priv(dev);
872 int npi, proto;
873 unsigned char *pp;
874
875 npi = ethertype_to_npindex(ntohs(skb->protocol));
876 if (npi < 0)
877 goto outf;
878
879 /* Drop, accept or reject the packet */
880 switch (ppp->npmode[npi]) {
881 case NPMODE_PASS:
882 break;
883 case NPMODE_QUEUE:
884 /* it would be nice to have a way to tell the network
885 system to queue this one up for later. */
886 goto outf;
887 case NPMODE_DROP:
888 case NPMODE_ERROR:
889 goto outf;
890 }
891
892 /* Put the 2-byte PPP protocol number on the front,
893 making sure there is room for the address and control fields. */
894 if (skb_cow_head(skb, PPP_HDRLEN))
895 goto outf;
896
897 pp = skb_push(skb, 2);
898 proto = npindex_to_proto[npi];
899 pp[0] = proto >> 8;
900 pp[1] = proto;
901
902 netif_stop_queue(dev);
903 skb_queue_tail(&ppp->file.xq, skb);
904 ppp_xmit_process(ppp);
905 return 0;
906
907 outf:
908 kfree_skb(skb);
909 ++ppp->dev->stats.tx_dropped;
910 return 0;
911 }
912
913 static int
914 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
915 {
916 struct ppp *ppp = netdev_priv(dev);
917 int err = -EFAULT;
918 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
919 struct ppp_stats stats;
920 struct ppp_comp_stats cstats;
921 char *vers;
922
923 switch (cmd) {
924 case SIOCGPPPSTATS:
925 ppp_get_stats(ppp, &stats);
926 if (copy_to_user(addr, &stats, sizeof(stats)))
927 break;
928 err = 0;
929 break;
930
931 case SIOCGPPPCSTATS:
932 memset(&cstats, 0, sizeof(cstats));
933 if (ppp->xc_state)
934 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
935 if (ppp->rc_state)
936 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
937 if (copy_to_user(addr, &cstats, sizeof(cstats)))
938 break;
939 err = 0;
940 break;
941
942 case SIOCGPPPVER:
943 vers = PPP_VERSION;
944 if (copy_to_user(addr, vers, strlen(vers) + 1))
945 break;
946 err = 0;
947 break;
948
949 default:
950 err = -EINVAL;
951 }
952
953 return err;
954 }
955
956 static const struct net_device_ops ppp_netdev_ops = {
957 .ndo_start_xmit = ppp_start_xmit,
958 .ndo_do_ioctl = ppp_net_ioctl,
959 };
960
961 static void ppp_setup(struct net_device *dev)
962 {
963 dev->netdev_ops = &ppp_netdev_ops;
964 dev->hard_header_len = PPP_HDRLEN;
965 dev->mtu = PPP_MTU;
966 dev->addr_len = 0;
967 dev->tx_queue_len = 3;
968 dev->type = ARPHRD_PPP;
969 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
970 }
971
972 /*
973 * Transmit-side routines.
974 */
975
976 /*
977 * Called to do any work queued up on the transmit side
978 * that can now be done.
979 */
980 static void
981 ppp_xmit_process(struct ppp *ppp)
982 {
983 struct sk_buff *skb;
984
985 ppp_xmit_lock(ppp);
986 if (ppp->dev) {
987 ppp_push(ppp);
988 while (!ppp->xmit_pending
989 && (skb = skb_dequeue(&ppp->file.xq)))
990 ppp_send_frame(ppp, skb);
991 /* If there's no work left to do, tell the core net
992 code that we can accept some more. */
993 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
994 netif_wake_queue(ppp->dev);
995 }
996 ppp_xmit_unlock(ppp);
997 }
998
999 static inline struct sk_buff *
1000 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1001 {
1002 struct sk_buff *new_skb;
1003 int len;
1004 int new_skb_size = ppp->dev->mtu +
1005 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1006 int compressor_skb_size = ppp->dev->mtu +
1007 ppp->xcomp->comp_extra + PPP_HDRLEN;
1008 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1009 if (!new_skb) {
1010 if (net_ratelimit())
1011 printk(KERN_ERR "PPP: no memory (comp pkt)\n");
1012 return NULL;
1013 }
1014 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1015 skb_reserve(new_skb,
1016 ppp->dev->hard_header_len - PPP_HDRLEN);
1017
1018 /* compressor still expects A/C bytes in hdr */
1019 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1020 new_skb->data, skb->len + 2,
1021 compressor_skb_size);
1022 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1023 kfree_skb(skb);
1024 skb = new_skb;
1025 skb_put(skb, len);
1026 skb_pull(skb, 2); /* pull off A/C bytes */
1027 } else if (len == 0) {
1028 /* didn't compress, or CCP not up yet */
1029 kfree_skb(new_skb);
1030 new_skb = skb;
1031 } else {
1032 /*
1033 * (len < 0)
1034 * MPPE requires that we do not send unencrypted
1035 * frames. The compressor will return -1 if we
1036 * should drop the frame. We cannot simply test
1037 * the compress_proto because MPPE and MPPC share
1038 * the same number.
1039 */
1040 if (net_ratelimit())
1041 printk(KERN_ERR "ppp: compressor dropped pkt\n");
1042 kfree_skb(skb);
1043 kfree_skb(new_skb);
1044 new_skb = NULL;
1045 }
1046 return new_skb;
1047 }
1048
1049 /*
1050 * Compress and send a frame.
1051 * The caller should have locked the xmit path,
1052 * and xmit_pending should be 0.
1053 */
1054 static void
1055 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1056 {
1057 int proto = PPP_PROTO(skb);
1058 struct sk_buff *new_skb;
1059 int len;
1060 unsigned char *cp;
1061
1062 if (proto < 0x8000) {
1063 #ifdef CONFIG_PPP_FILTER
1064 /* check if we should pass this packet */
1065 /* the filter instructions are constructed assuming
1066 a four-byte PPP header on each packet */
1067 *skb_push(skb, 2) = 1;
1068 if (ppp->pass_filter
1069 && sk_run_filter(skb, ppp->pass_filter,
1070 ppp->pass_len) == 0) {
1071 if (ppp->debug & 1)
1072 printk(KERN_DEBUG "PPP: outbound frame not passed\n");
1073 kfree_skb(skb);
1074 return;
1075 }
1076 /* if this packet passes the active filter, record the time */
1077 if (!(ppp->active_filter
1078 && sk_run_filter(skb, ppp->active_filter,
1079 ppp->active_len) == 0))
1080 ppp->last_xmit = jiffies;
1081 skb_pull(skb, 2);
1082 #else
1083 /* for data packets, record the time */
1084 ppp->last_xmit = jiffies;
1085 #endif /* CONFIG_PPP_FILTER */
1086 }
1087
1088 ++ppp->dev->stats.tx_packets;
1089 ppp->dev->stats.tx_bytes += skb->len - 2;
1090
1091 switch (proto) {
1092 case PPP_IP:
1093 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1094 break;
1095 /* try to do VJ TCP header compression */
1096 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1097 GFP_ATOMIC);
1098 if (!new_skb) {
1099 printk(KERN_ERR "PPP: no memory (VJ comp pkt)\n");
1100 goto drop;
1101 }
1102 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1103 cp = skb->data + 2;
1104 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1105 new_skb->data + 2, &cp,
1106 !(ppp->flags & SC_NO_TCP_CCID));
1107 if (cp == skb->data + 2) {
1108 /* didn't compress */
1109 kfree_skb(new_skb);
1110 } else {
1111 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1112 proto = PPP_VJC_COMP;
1113 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1114 } else {
1115 proto = PPP_VJC_UNCOMP;
1116 cp[0] = skb->data[2];
1117 }
1118 kfree_skb(skb);
1119 skb = new_skb;
1120 cp = skb_put(skb, len + 2);
1121 cp[0] = 0;
1122 cp[1] = proto;
1123 }
1124 break;
1125
1126 case PPP_CCP:
1127 /* peek at outbound CCP frames */
1128 ppp_ccp_peek(ppp, skb, 0);
1129 break;
1130 }
1131
1132 /* try to do packet compression */
1133 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state
1134 && proto != PPP_LCP && proto != PPP_CCP) {
1135 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1136 if (net_ratelimit())
1137 printk(KERN_ERR "ppp: compression required but down - pkt dropped.\n");
1138 goto drop;
1139 }
1140 skb = pad_compress_skb(ppp, skb);
1141 if (!skb)
1142 goto drop;
1143 }
1144
1145 /*
1146 * If we are waiting for traffic (demand dialling),
1147 * queue it up for pppd to receive.
1148 */
1149 if (ppp->flags & SC_LOOP_TRAFFIC) {
1150 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1151 goto drop;
1152 skb_queue_tail(&ppp->file.rq, skb);
1153 wake_up_interruptible(&ppp->file.rwait);
1154 return;
1155 }
1156
1157 ppp->xmit_pending = skb;
1158 ppp_push(ppp);
1159 return;
1160
1161 drop:
1162 if (skb)
1163 kfree_skb(skb);
1164 ++ppp->dev->stats.tx_errors;
1165 }
1166
1167 /*
1168 * Try to send the frame in xmit_pending.
1169 * The caller should have the xmit path locked.
1170 */
1171 static void
1172 ppp_push(struct ppp *ppp)
1173 {
1174 struct list_head *list;
1175 struct channel *pch;
1176 struct sk_buff *skb = ppp->xmit_pending;
1177
1178 if (!skb)
1179 return;
1180
1181 list = &ppp->channels;
1182 if (list_empty(list)) {
1183 /* nowhere to send the packet, just drop it */
1184 ppp->xmit_pending = NULL;
1185 kfree_skb(skb);
1186 return;
1187 }
1188
1189 if ((ppp->flags & SC_MULTILINK) == 0) {
1190 /* not doing multilink: send it down the first channel */
1191 list = list->next;
1192 pch = list_entry(list, struct channel, clist);
1193
1194 spin_lock_bh(&pch->downl);
1195 if (pch->chan) {
1196 if (pch->chan->ops->start_xmit(pch->chan, skb))
1197 ppp->xmit_pending = NULL;
1198 } else {
1199 /* channel got unregistered */
1200 kfree_skb(skb);
1201 ppp->xmit_pending = NULL;
1202 }
1203 spin_unlock_bh(&pch->downl);
1204 return;
1205 }
1206
1207 #ifdef CONFIG_PPP_MULTILINK
1208 /* Multilink: fragment the packet over as many links
1209 as can take the packet at the moment. */
1210 if (!ppp_mp_explode(ppp, skb))
1211 return;
1212 #endif /* CONFIG_PPP_MULTILINK */
1213
1214 ppp->xmit_pending = NULL;
1215 kfree_skb(skb);
1216 }
1217
1218 #ifdef CONFIG_PPP_MULTILINK
1219 /*
1220 * Divide a packet to be transmitted into fragments and
1221 * send them out the individual links.
1222 */
1223 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1224 {
1225 int len, fragsize;
1226 int i, bits, hdrlen, mtu;
1227 int flen;
1228 int navail, nfree;
1229 int nbigger;
1230 unsigned char *p, *q;
1231 struct list_head *list;
1232 struct channel *pch;
1233 struct sk_buff *frag;
1234 struct ppp_channel *chan;
1235
1236 nfree = 0; /* # channels which have no packet already queued */
1237 navail = 0; /* total # of usable channels (not deregistered) */
1238 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1239 i = 0;
1240 list_for_each_entry(pch, &ppp->channels, clist) {
1241 navail += pch->avail = (pch->chan != NULL);
1242 if (pch->avail) {
1243 if (skb_queue_empty(&pch->file.xq) ||
1244 !pch->had_frag) {
1245 pch->avail = 2;
1246 ++nfree;
1247 }
1248 if (!pch->had_frag && i < ppp->nxchan)
1249 ppp->nxchan = i;
1250 }
1251 ++i;
1252 }
1253
1254 /*
1255 * Don't start sending this packet unless at least half of
1256 * the channels are free. This gives much better TCP
1257 * performance if we have a lot of channels.
1258 */
1259 if (nfree == 0 || nfree < navail / 2)
1260 return 0; /* can't take now, leave it in xmit_pending */
1261
1262 /* Do protocol field compression (XXX this should be optional) */
1263 p = skb->data;
1264 len = skb->len;
1265 if (*p == 0) {
1266 ++p;
1267 --len;
1268 }
1269
1270 /*
1271 * Decide on fragment size.
1272 * We create a fragment for each free channel regardless of
1273 * how small they are (i.e. even 0 length) in order to minimize
1274 * the time that it will take to detect when a channel drops
1275 * a fragment.
1276 */
1277 fragsize = len;
1278 if (nfree > 1)
1279 fragsize = DIV_ROUND_UP(fragsize, nfree);
1280 /* nbigger channels get fragsize bytes, the rest get fragsize-1,
1281 except if nbigger==0, then they all get fragsize. */
1282 nbigger = len % nfree;
1283
1284 /* skip to the channel after the one we last used
1285 and start at that one */
1286 list = &ppp->channels;
1287 for (i = 0; i < ppp->nxchan; ++i) {
1288 list = list->next;
1289 if (list == &ppp->channels) {
1290 i = 0;
1291 break;
1292 }
1293 }
1294
1295 /* create a fragment for each channel */
1296 bits = B;
1297 while (nfree > 0 || len > 0) {
1298 list = list->next;
1299 if (list == &ppp->channels) {
1300 i = 0;
1301 continue;
1302 }
1303 pch = list_entry(list, struct channel, clist);
1304 ++i;
1305 if (!pch->avail)
1306 continue;
1307
1308 /*
1309 * Skip this channel if it has a fragment pending already and
1310 * we haven't given a fragment to all of the free channels.
1311 */
1312 if (pch->avail == 1) {
1313 if (nfree > 0)
1314 continue;
1315 } else {
1316 --nfree;
1317 pch->avail = 1;
1318 }
1319
1320 /* check the channel's mtu and whether it is still attached. */
1321 spin_lock_bh(&pch->downl);
1322 if (pch->chan == NULL) {
1323 /* can't use this channel, it's being deregistered */
1324 spin_unlock_bh(&pch->downl);
1325 pch->avail = 0;
1326 if (--navail == 0)
1327 break;
1328 continue;
1329 }
1330
1331 /*
1332 * Create a fragment for this channel of
1333 * min(max(mtu+2-hdrlen, 4), fragsize, len) bytes.
1334 * If mtu+2-hdrlen < 4, that is a ridiculously small
1335 * MTU, so we use mtu = 2 + hdrlen.
1336 */
1337 if (fragsize > len)
1338 fragsize = len;
1339 flen = fragsize;
1340 mtu = pch->chan->mtu + 2 - hdrlen;
1341 if (mtu < 4)
1342 mtu = 4;
1343 if (flen > mtu)
1344 flen = mtu;
1345 if (flen == len && nfree == 0)
1346 bits |= E;
1347 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1348 if (!frag)
1349 goto noskb;
1350 q = skb_put(frag, flen + hdrlen);
1351
1352 /* make the MP header */
1353 q[0] = PPP_MP >> 8;
1354 q[1] = PPP_MP;
1355 if (ppp->flags & SC_MP_XSHORTSEQ) {
1356 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1357 q[3] = ppp->nxseq;
1358 } else {
1359 q[2] = bits;
1360 q[3] = ppp->nxseq >> 16;
1361 q[4] = ppp->nxseq >> 8;
1362 q[5] = ppp->nxseq;
1363 }
1364
1365 /*
1366 * Copy the data in.
1367 * Unfortunately there is a bug in older versions of
1368 * the Linux PPP multilink reconstruction code where it
1369 * drops 0-length fragments. Therefore we make sure the
1370 * fragment has at least one byte of data. Any bytes
1371 * we add in this situation will end up as padding on the
1372 * end of the reconstructed packet.
1373 */
1374 if (flen == 0)
1375 *skb_put(frag, 1) = 0;
1376 else
1377 memcpy(q + hdrlen, p, flen);
1378
1379 /* try to send it down the channel */
1380 chan = pch->chan;
1381 if (!skb_queue_empty(&pch->file.xq) ||
1382 !chan->ops->start_xmit(chan, frag))
1383 skb_queue_tail(&pch->file.xq, frag);
1384 pch->had_frag = 1;
1385 p += flen;
1386 len -= flen;
1387 ++ppp->nxseq;
1388 bits = 0;
1389 spin_unlock_bh(&pch->downl);
1390
1391 if (--nbigger == 0 && fragsize > 0)
1392 --fragsize;
1393 }
1394 ppp->nxchan = i;
1395
1396 return 1;
1397
1398 noskb:
1399 spin_unlock_bh(&pch->downl);
1400 if (ppp->debug & 1)
1401 printk(KERN_ERR "PPP: no memory (fragment)\n");
1402 ++ppp->dev->stats.tx_errors;
1403 ++ppp->nxseq;
1404 return 1; /* abandon the frame */
1405 }
1406 #endif /* CONFIG_PPP_MULTILINK */
1407
1408 /*
1409 * Try to send data out on a channel.
1410 */
1411 static void
1412 ppp_channel_push(struct channel *pch)
1413 {
1414 struct sk_buff *skb;
1415 struct ppp *ppp;
1416
1417 spin_lock_bh(&pch->downl);
1418 if (pch->chan) {
1419 while (!skb_queue_empty(&pch->file.xq)) {
1420 skb = skb_dequeue(&pch->file.xq);
1421 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1422 /* put the packet back and try again later */
1423 skb_queue_head(&pch->file.xq, skb);
1424 break;
1425 }
1426 }
1427 } else {
1428 /* channel got deregistered */
1429 skb_queue_purge(&pch->file.xq);
1430 }
1431 spin_unlock_bh(&pch->downl);
1432 /* see if there is anything from the attached unit to be sent */
1433 if (skb_queue_empty(&pch->file.xq)) {
1434 read_lock_bh(&pch->upl);
1435 ppp = pch->ppp;
1436 if (ppp)
1437 ppp_xmit_process(ppp);
1438 read_unlock_bh(&pch->upl);
1439 }
1440 }
1441
1442 /*
1443 * Receive-side routines.
1444 */
1445
1446 /* misuse a few fields of the skb for MP reconstruction */
1447 #define sequence priority
1448 #define BEbits cb[0]
1449
1450 static inline void
1451 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1452 {
1453 ppp_recv_lock(ppp);
1454 /* ppp->dev == 0 means interface is closing down */
1455 if (ppp->dev)
1456 ppp_receive_frame(ppp, skb, pch);
1457 else
1458 kfree_skb(skb);
1459 ppp_recv_unlock(ppp);
1460 }
1461
1462 void
1463 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1464 {
1465 struct channel *pch = chan->ppp;
1466 int proto;
1467
1468 if (!pch || skb->len == 0) {
1469 kfree_skb(skb);
1470 return;
1471 }
1472
1473 proto = PPP_PROTO(skb);
1474 read_lock_bh(&pch->upl);
1475 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1476 /* put it on the channel queue */
1477 skb_queue_tail(&pch->file.rq, skb);
1478 /* drop old frames if queue too long */
1479 while (pch->file.rq.qlen > PPP_MAX_RQLEN
1480 && (skb = skb_dequeue(&pch->file.rq)))
1481 kfree_skb(skb);
1482 wake_up_interruptible(&pch->file.rwait);
1483 } else {
1484 ppp_do_recv(pch->ppp, skb, pch);
1485 }
1486 read_unlock_bh(&pch->upl);
1487 }
1488
1489 /* Put a 0-length skb in the receive queue as an error indication */
1490 void
1491 ppp_input_error(struct ppp_channel *chan, int code)
1492 {
1493 struct channel *pch = chan->ppp;
1494 struct sk_buff *skb;
1495
1496 if (!pch)
1497 return;
1498
1499 read_lock_bh(&pch->upl);
1500 if (pch->ppp) {
1501 skb = alloc_skb(0, GFP_ATOMIC);
1502 if (skb) {
1503 skb->len = 0; /* probably unnecessary */
1504 skb->cb[0] = code;
1505 ppp_do_recv(pch->ppp, skb, pch);
1506 }
1507 }
1508 read_unlock_bh(&pch->upl);
1509 }
1510
1511 /*
1512 * We come in here to process a received frame.
1513 * The receive side of the ppp unit is locked.
1514 */
1515 static void
1516 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1517 {
1518 if (pskb_may_pull(skb, 2)) {
1519 #ifdef CONFIG_PPP_MULTILINK
1520 /* XXX do channel-level decompression here */
1521 if (PPP_PROTO(skb) == PPP_MP)
1522 ppp_receive_mp_frame(ppp, skb, pch);
1523 else
1524 #endif /* CONFIG_PPP_MULTILINK */
1525 ppp_receive_nonmp_frame(ppp, skb);
1526 return;
1527 }
1528
1529 if (skb->len > 0)
1530 /* note: a 0-length skb is used as an error indication */
1531 ++ppp->dev->stats.rx_length_errors;
1532
1533 kfree_skb(skb);
1534 ppp_receive_error(ppp);
1535 }
1536
1537 static void
1538 ppp_receive_error(struct ppp *ppp)
1539 {
1540 ++ppp->dev->stats.rx_errors;
1541 if (ppp->vj)
1542 slhc_toss(ppp->vj);
1543 }
1544
1545 static void
1546 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1547 {
1548 struct sk_buff *ns;
1549 int proto, len, npi;
1550
1551 /*
1552 * Decompress the frame, if compressed.
1553 * Note that some decompressors need to see uncompressed frames
1554 * that come in as well as compressed frames.
1555 */
1556 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)
1557 && (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1558 skb = ppp_decompress_frame(ppp, skb);
1559
1560 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1561 goto err;
1562
1563 proto = PPP_PROTO(skb);
1564 switch (proto) {
1565 case PPP_VJC_COMP:
1566 /* decompress VJ compressed packets */
1567 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1568 goto err;
1569
1570 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1571 /* copy to a new sk_buff with more tailroom */
1572 ns = dev_alloc_skb(skb->len + 128);
1573 if (!ns) {
1574 printk(KERN_ERR"PPP: no memory (VJ decomp)\n");
1575 goto err;
1576 }
1577 skb_reserve(ns, 2);
1578 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1579 kfree_skb(skb);
1580 skb = ns;
1581 }
1582 else
1583 skb->ip_summed = CHECKSUM_NONE;
1584
1585 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1586 if (len <= 0) {
1587 printk(KERN_DEBUG "PPP: VJ decompression error\n");
1588 goto err;
1589 }
1590 len += 2;
1591 if (len > skb->len)
1592 skb_put(skb, len - skb->len);
1593 else if (len < skb->len)
1594 skb_trim(skb, len);
1595 proto = PPP_IP;
1596 break;
1597
1598 case PPP_VJC_UNCOMP:
1599 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1600 goto err;
1601
1602 /* Until we fix the decompressor need to make sure
1603 * data portion is linear.
1604 */
1605 if (!pskb_may_pull(skb, skb->len))
1606 goto err;
1607
1608 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1609 printk(KERN_ERR "PPP: VJ uncompressed error\n");
1610 goto err;
1611 }
1612 proto = PPP_IP;
1613 break;
1614
1615 case PPP_CCP:
1616 ppp_ccp_peek(ppp, skb, 1);
1617 break;
1618 }
1619
1620 ++ppp->dev->stats.rx_packets;
1621 ppp->dev->stats.rx_bytes += skb->len - 2;
1622
1623 npi = proto_to_npindex(proto);
1624 if (npi < 0) {
1625 /* control or unknown frame - pass it to pppd */
1626 skb_queue_tail(&ppp->file.rq, skb);
1627 /* limit queue length by dropping old frames */
1628 while (ppp->file.rq.qlen > PPP_MAX_RQLEN
1629 && (skb = skb_dequeue(&ppp->file.rq)))
1630 kfree_skb(skb);
1631 /* wake up any process polling or blocking on read */
1632 wake_up_interruptible(&ppp->file.rwait);
1633
1634 } else {
1635 /* network protocol frame - give it to the kernel */
1636
1637 #ifdef CONFIG_PPP_FILTER
1638 /* check if the packet passes the pass and active filters */
1639 /* the filter instructions are constructed assuming
1640 a four-byte PPP header on each packet */
1641 if (ppp->pass_filter || ppp->active_filter) {
1642 if (skb_cloned(skb) &&
1643 pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
1644 goto err;
1645
1646 *skb_push(skb, 2) = 0;
1647 if (ppp->pass_filter
1648 && sk_run_filter(skb, ppp->pass_filter,
1649 ppp->pass_len) == 0) {
1650 if (ppp->debug & 1)
1651 printk(KERN_DEBUG "PPP: inbound frame "
1652 "not passed\n");
1653 kfree_skb(skb);
1654 return;
1655 }
1656 if (!(ppp->active_filter
1657 && sk_run_filter(skb, ppp->active_filter,
1658 ppp->active_len) == 0))
1659 ppp->last_recv = jiffies;
1660 __skb_pull(skb, 2);
1661 } else
1662 #endif /* CONFIG_PPP_FILTER */
1663 ppp->last_recv = jiffies;
1664
1665 if ((ppp->dev->flags & IFF_UP) == 0
1666 || ppp->npmode[npi] != NPMODE_PASS) {
1667 kfree_skb(skb);
1668 } else {
1669 /* chop off protocol */
1670 skb_pull_rcsum(skb, 2);
1671 skb->dev = ppp->dev;
1672 skb->protocol = htons(npindex_to_ethertype[npi]);
1673 skb_reset_mac_header(skb);
1674 netif_rx(skb);
1675 }
1676 }
1677 return;
1678
1679 err:
1680 kfree_skb(skb);
1681 ppp_receive_error(ppp);
1682 }
1683
1684 static struct sk_buff *
1685 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1686 {
1687 int proto = PPP_PROTO(skb);
1688 struct sk_buff *ns;
1689 int len;
1690
1691 /* Until we fix all the decompressor's need to make sure
1692 * data portion is linear.
1693 */
1694 if (!pskb_may_pull(skb, skb->len))
1695 goto err;
1696
1697 if (proto == PPP_COMP) {
1698 int obuff_size;
1699
1700 switch(ppp->rcomp->compress_proto) {
1701 case CI_MPPE:
1702 obuff_size = ppp->mru + PPP_HDRLEN + 1;
1703 break;
1704 default:
1705 obuff_size = ppp->mru + PPP_HDRLEN;
1706 break;
1707 }
1708
1709 ns = dev_alloc_skb(obuff_size);
1710 if (!ns) {
1711 printk(KERN_ERR "ppp_decompress_frame: no memory\n");
1712 goto err;
1713 }
1714 /* the decompressor still expects the A/C bytes in the hdr */
1715 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1716 skb->len + 2, ns->data, obuff_size);
1717 if (len < 0) {
1718 /* Pass the compressed frame to pppd as an
1719 error indication. */
1720 if (len == DECOMP_FATALERROR)
1721 ppp->rstate |= SC_DC_FERROR;
1722 kfree_skb(ns);
1723 goto err;
1724 }
1725
1726 kfree_skb(skb);
1727 skb = ns;
1728 skb_put(skb, len);
1729 skb_pull(skb, 2); /* pull off the A/C bytes */
1730
1731 } else {
1732 /* Uncompressed frame - pass to decompressor so it
1733 can update its dictionary if necessary. */
1734 if (ppp->rcomp->incomp)
1735 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1736 skb->len + 2);
1737 }
1738
1739 return skb;
1740
1741 err:
1742 ppp->rstate |= SC_DC_ERROR;
1743 ppp_receive_error(ppp);
1744 return skb;
1745 }
1746
1747 #ifdef CONFIG_PPP_MULTILINK
1748 /*
1749 * Receive a multilink frame.
1750 * We put it on the reconstruction queue and then pull off
1751 * as many completed frames as we can.
1752 */
1753 static void
1754 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1755 {
1756 u32 mask, seq;
1757 struct channel *ch;
1758 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1759
1760 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
1761 goto err; /* no good, throw it away */
1762
1763 /* Decode sequence number and begin/end bits */
1764 if (ppp->flags & SC_MP_SHORTSEQ) {
1765 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1766 mask = 0xfff;
1767 } else {
1768 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1769 mask = 0xffffff;
1770 }
1771 skb->BEbits = skb->data[2];
1772 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
1773
1774 /*
1775 * Do protocol ID decompression on the first fragment of each packet.
1776 */
1777 if ((skb->BEbits & B) && (skb->data[0] & 1))
1778 *skb_push(skb, 1) = 0;
1779
1780 /*
1781 * Expand sequence number to 32 bits, making it as close
1782 * as possible to ppp->minseq.
1783 */
1784 seq |= ppp->minseq & ~mask;
1785 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
1786 seq += mask + 1;
1787 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
1788 seq -= mask + 1; /* should never happen */
1789 skb->sequence = seq;
1790 pch->lastseq = seq;
1791
1792 /*
1793 * If this packet comes before the next one we were expecting,
1794 * drop it.
1795 */
1796 if (seq_before(seq, ppp->nextseq)) {
1797 kfree_skb(skb);
1798 ++ppp->dev->stats.rx_dropped;
1799 ppp_receive_error(ppp);
1800 return;
1801 }
1802
1803 /*
1804 * Reevaluate minseq, the minimum over all channels of the
1805 * last sequence number received on each channel. Because of
1806 * the increasing sequence number rule, we know that any fragment
1807 * before `minseq' which hasn't arrived is never going to arrive.
1808 * The list of channels can't change because we have the receive
1809 * side of the ppp unit locked.
1810 */
1811 list_for_each_entry(ch, &ppp->channels, clist) {
1812 if (seq_before(ch->lastseq, seq))
1813 seq = ch->lastseq;
1814 }
1815 if (seq_before(ppp->minseq, seq))
1816 ppp->minseq = seq;
1817
1818 /* Put the fragment on the reconstruction queue */
1819 ppp_mp_insert(ppp, skb);
1820
1821 /* If the queue is getting long, don't wait any longer for packets
1822 before the start of the queue. */
1823 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
1824 struct sk_buff *skb = skb_peek(&ppp->mrq);
1825 if (seq_before(ppp->minseq, skb->sequence))
1826 ppp->minseq = skb->sequence;
1827 }
1828
1829 /* Pull completed packets off the queue and receive them. */
1830 while ((skb = ppp_mp_reconstruct(ppp)))
1831 ppp_receive_nonmp_frame(ppp, skb);
1832
1833 return;
1834
1835 err:
1836 kfree_skb(skb);
1837 ppp_receive_error(ppp);
1838 }
1839
1840 /*
1841 * Insert a fragment on the MP reconstruction queue.
1842 * The queue is ordered by increasing sequence number.
1843 */
1844 static void
1845 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
1846 {
1847 struct sk_buff *p;
1848 struct sk_buff_head *list = &ppp->mrq;
1849 u32 seq = skb->sequence;
1850
1851 /* N.B. we don't need to lock the list lock because we have the
1852 ppp unit receive-side lock. */
1853 skb_queue_walk(list, p) {
1854 if (seq_before(seq, p->sequence))
1855 break;
1856 }
1857 __skb_queue_before(list, p, skb);
1858 }
1859
1860 /*
1861 * Reconstruct a packet from the MP fragment queue.
1862 * We go through increasing sequence numbers until we find a
1863 * complete packet, or we get to the sequence number for a fragment
1864 * which hasn't arrived but might still do so.
1865 */
1866 static struct sk_buff *
1867 ppp_mp_reconstruct(struct ppp *ppp)
1868 {
1869 u32 seq = ppp->nextseq;
1870 u32 minseq = ppp->minseq;
1871 struct sk_buff_head *list = &ppp->mrq;
1872 struct sk_buff *p, *next;
1873 struct sk_buff *head, *tail;
1874 struct sk_buff *skb = NULL;
1875 int lost = 0, len = 0;
1876
1877 if (ppp->mrru == 0) /* do nothing until mrru is set */
1878 return NULL;
1879 head = list->next;
1880 tail = NULL;
1881 for (p = head; p != (struct sk_buff *) list; p = next) {
1882 next = p->next;
1883 if (seq_before(p->sequence, seq)) {
1884 /* this can't happen, anyway ignore the skb */
1885 printk(KERN_ERR "ppp_mp_reconstruct bad seq %u < %u\n",
1886 p->sequence, seq);
1887 head = next;
1888 continue;
1889 }
1890 if (p->sequence != seq) {
1891 /* Fragment `seq' is missing. If it is after
1892 minseq, it might arrive later, so stop here. */
1893 if (seq_after(seq, minseq))
1894 break;
1895 /* Fragment `seq' is lost, keep going. */
1896 lost = 1;
1897 seq = seq_before(minseq, p->sequence)?
1898 minseq + 1: p->sequence;
1899 next = p;
1900 continue;
1901 }
1902
1903 /*
1904 * At this point we know that all the fragments from
1905 * ppp->nextseq to seq are either present or lost.
1906 * Also, there are no complete packets in the queue
1907 * that have no missing fragments and end before this
1908 * fragment.
1909 */
1910
1911 /* B bit set indicates this fragment starts a packet */
1912 if (p->BEbits & B) {
1913 head = p;
1914 lost = 0;
1915 len = 0;
1916 }
1917
1918 len += p->len;
1919
1920 /* Got a complete packet yet? */
1921 if (lost == 0 && (p->BEbits & E) && (head->BEbits & B)) {
1922 if (len > ppp->mrru + 2) {
1923 ++ppp->dev->stats.rx_length_errors;
1924 printk(KERN_DEBUG "PPP: reconstructed packet"
1925 " is too long (%d)\n", len);
1926 } else if (p == head) {
1927 /* fragment is complete packet - reuse skb */
1928 tail = p;
1929 skb = skb_get(p);
1930 break;
1931 } else if ((skb = dev_alloc_skb(len)) == NULL) {
1932 ++ppp->dev->stats.rx_missed_errors;
1933 printk(KERN_DEBUG "PPP: no memory for "
1934 "reconstructed packet");
1935 } else {
1936 tail = p;
1937 break;
1938 }
1939 ppp->nextseq = seq + 1;
1940 }
1941
1942 /*
1943 * If this is the ending fragment of a packet,
1944 * and we haven't found a complete valid packet yet,
1945 * we can discard up to and including this fragment.
1946 */
1947 if (p->BEbits & E)
1948 head = next;
1949
1950 ++seq;
1951 }
1952
1953 /* If we have a complete packet, copy it all into one skb. */
1954 if (tail != NULL) {
1955 /* If we have discarded any fragments,
1956 signal a receive error. */
1957 if (head->sequence != ppp->nextseq) {
1958 if (ppp->debug & 1)
1959 printk(KERN_DEBUG " missed pkts %u..%u\n",
1960 ppp->nextseq, head->sequence-1);
1961 ++ppp->dev->stats.rx_dropped;
1962 ppp_receive_error(ppp);
1963 }
1964
1965 if (head != tail)
1966 /* copy to a single skb */
1967 for (p = head; p != tail->next; p = p->next)
1968 skb_copy_bits(p, 0, skb_put(skb, p->len), p->len);
1969 ppp->nextseq = tail->sequence + 1;
1970 head = tail->next;
1971 }
1972
1973 /* Discard all the skbuffs that we have copied the data out of
1974 or that we can't use. */
1975 while ((p = list->next) != head) {
1976 __skb_unlink(p, list);
1977 kfree_skb(p);
1978 }
1979
1980 return skb;
1981 }
1982 #endif /* CONFIG_PPP_MULTILINK */
1983
1984 /*
1985 * Channel interface.
1986 */
1987
1988 /*
1989 * Create a new, unattached ppp channel.
1990 */
1991 int
1992 ppp_register_channel(struct ppp_channel *chan)
1993 {
1994 struct channel *pch;
1995
1996 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
1997 if (!pch)
1998 return -ENOMEM;
1999 pch->ppp = NULL;
2000 pch->chan = chan;
2001 chan->ppp = pch;
2002 init_ppp_file(&pch->file, CHANNEL);
2003 pch->file.hdrlen = chan->hdrlen;
2004 #ifdef CONFIG_PPP_MULTILINK
2005 pch->lastseq = -1;
2006 #endif /* CONFIG_PPP_MULTILINK */
2007 init_rwsem(&pch->chan_sem);
2008 spin_lock_init(&pch->downl);
2009 rwlock_init(&pch->upl);
2010 spin_lock_bh(&all_channels_lock);
2011 pch->file.index = ++last_channel_index;
2012 list_add(&pch->list, &new_channels);
2013 atomic_inc(&channel_count);
2014 spin_unlock_bh(&all_channels_lock);
2015 return 0;
2016 }
2017
2018 /*
2019 * Return the index of a channel.
2020 */
2021 int ppp_channel_index(struct ppp_channel *chan)
2022 {
2023 struct channel *pch = chan->ppp;
2024
2025 if (pch)
2026 return pch->file.index;
2027 return -1;
2028 }
2029
2030 /*
2031 * Return the PPP unit number to which a channel is connected.
2032 */
2033 int ppp_unit_number(struct ppp_channel *chan)
2034 {
2035 struct channel *pch = chan->ppp;
2036 int unit = -1;
2037
2038 if (pch) {
2039 read_lock_bh(&pch->upl);
2040 if (pch->ppp)
2041 unit = pch->ppp->file.index;
2042 read_unlock_bh(&pch->upl);
2043 }
2044 return unit;
2045 }
2046
2047 /*
2048 * Disconnect a channel from the generic layer.
2049 * This must be called in process context.
2050 */
2051 void
2052 ppp_unregister_channel(struct ppp_channel *chan)
2053 {
2054 struct channel *pch = chan->ppp;
2055
2056 if (!pch)
2057 return; /* should never happen */
2058 chan->ppp = NULL;
2059
2060 /*
2061 * This ensures that we have returned from any calls into the
2062 * the channel's start_xmit or ioctl routine before we proceed.
2063 */
2064 down_write(&pch->chan_sem);
2065 spin_lock_bh(&pch->downl);
2066 pch->chan = NULL;
2067 spin_unlock_bh(&pch->downl);
2068 up_write(&pch->chan_sem);
2069 ppp_disconnect_channel(pch);
2070 spin_lock_bh(&all_channels_lock);
2071 list_del(&pch->list);
2072 spin_unlock_bh(&all_channels_lock);
2073 pch->file.dead = 1;
2074 wake_up_interruptible(&pch->file.rwait);
2075 if (atomic_dec_and_test(&pch->file.refcnt))
2076 ppp_destroy_channel(pch);
2077 }
2078
2079 /*
2080 * Callback from a channel when it can accept more to transmit.
2081 * This should be called at BH/softirq level, not interrupt level.
2082 */
2083 void
2084 ppp_output_wakeup(struct ppp_channel *chan)
2085 {
2086 struct channel *pch = chan->ppp;
2087
2088 if (!pch)
2089 return;
2090 ppp_channel_push(pch);
2091 }
2092
2093 /*
2094 * Compression control.
2095 */
2096
2097 /* Process the PPPIOCSCOMPRESS ioctl. */
2098 static int
2099 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2100 {
2101 int err;
2102 struct compressor *cp, *ocomp;
2103 struct ppp_option_data data;
2104 void *state, *ostate;
2105 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2106
2107 err = -EFAULT;
2108 if (copy_from_user(&data, (void __user *) arg, sizeof(data))
2109 || (data.length <= CCP_MAX_OPTION_LENGTH
2110 && copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2111 goto out;
2112 err = -EINVAL;
2113 if (data.length > CCP_MAX_OPTION_LENGTH
2114 || ccp_option[1] < 2 || ccp_option[1] > data.length)
2115 goto out;
2116
2117 cp = try_then_request_module(
2118 find_compressor(ccp_option[0]),
2119 "ppp-compress-%d", ccp_option[0]);
2120 if (!cp)
2121 goto out;
2122
2123 err = -ENOBUFS;
2124 if (data.transmit) {
2125 state = cp->comp_alloc(ccp_option, data.length);
2126 if (state) {
2127 ppp_xmit_lock(ppp);
2128 ppp->xstate &= ~SC_COMP_RUN;
2129 ocomp = ppp->xcomp;
2130 ostate = ppp->xc_state;
2131 ppp->xcomp = cp;
2132 ppp->xc_state = state;
2133 ppp_xmit_unlock(ppp);
2134 if (ostate) {
2135 ocomp->comp_free(ostate);
2136 module_put(ocomp->owner);
2137 }
2138 err = 0;
2139 } else
2140 module_put(cp->owner);
2141
2142 } else {
2143 state = cp->decomp_alloc(ccp_option, data.length);
2144 if (state) {
2145 ppp_recv_lock(ppp);
2146 ppp->rstate &= ~SC_DECOMP_RUN;
2147 ocomp = ppp->rcomp;
2148 ostate = ppp->rc_state;
2149 ppp->rcomp = cp;
2150 ppp->rc_state = state;
2151 ppp_recv_unlock(ppp);
2152 if (ostate) {
2153 ocomp->decomp_free(ostate);
2154 module_put(ocomp->owner);
2155 }
2156 err = 0;
2157 } else
2158 module_put(cp->owner);
2159 }
2160
2161 out:
2162 return err;
2163 }
2164
2165 /*
2166 * Look at a CCP packet and update our state accordingly.
2167 * We assume the caller has the xmit or recv path locked.
2168 */
2169 static void
2170 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2171 {
2172 unsigned char *dp;
2173 int len;
2174
2175 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2176 return; /* no header */
2177 dp = skb->data + 2;
2178
2179 switch (CCP_CODE(dp)) {
2180 case CCP_CONFREQ:
2181
2182 /* A ConfReq starts negotiation of compression
2183 * in one direction of transmission,
2184 * and hence brings it down...but which way?
2185 *
2186 * Remember:
2187 * A ConfReq indicates what the sender would like to receive
2188 */
2189 if(inbound)
2190 /* He is proposing what I should send */
2191 ppp->xstate &= ~SC_COMP_RUN;
2192 else
2193 /* I am proposing to what he should send */
2194 ppp->rstate &= ~SC_DECOMP_RUN;
2195
2196 break;
2197
2198 case CCP_TERMREQ:
2199 case CCP_TERMACK:
2200 /*
2201 * CCP is going down, both directions of transmission
2202 */
2203 ppp->rstate &= ~SC_DECOMP_RUN;
2204 ppp->xstate &= ~SC_COMP_RUN;
2205 break;
2206
2207 case CCP_CONFACK:
2208 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2209 break;
2210 len = CCP_LENGTH(dp);
2211 if (!pskb_may_pull(skb, len + 2))
2212 return; /* too short */
2213 dp += CCP_HDRLEN;
2214 len -= CCP_HDRLEN;
2215 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2216 break;
2217 if (inbound) {
2218 /* we will start receiving compressed packets */
2219 if (!ppp->rc_state)
2220 break;
2221 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2222 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2223 ppp->rstate |= SC_DECOMP_RUN;
2224 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2225 }
2226 } else {
2227 /* we will soon start sending compressed packets */
2228 if (!ppp->xc_state)
2229 break;
2230 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2231 ppp->file.index, 0, ppp->debug))
2232 ppp->xstate |= SC_COMP_RUN;
2233 }
2234 break;
2235
2236 case CCP_RESETACK:
2237 /* reset the [de]compressor */
2238 if ((ppp->flags & SC_CCP_UP) == 0)
2239 break;
2240 if (inbound) {
2241 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2242 ppp->rcomp->decomp_reset(ppp->rc_state);
2243 ppp->rstate &= ~SC_DC_ERROR;
2244 }
2245 } else {
2246 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2247 ppp->xcomp->comp_reset(ppp->xc_state);
2248 }
2249 break;
2250 }
2251 }
2252
2253 /* Free up compression resources. */
2254 static void
2255 ppp_ccp_closed(struct ppp *ppp)
2256 {
2257 void *xstate, *rstate;
2258 struct compressor *xcomp, *rcomp;
2259
2260 ppp_lock(ppp);
2261 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2262 ppp->xstate = 0;
2263 xcomp = ppp->xcomp;
2264 xstate = ppp->xc_state;
2265 ppp->xc_state = NULL;
2266 ppp->rstate = 0;
2267 rcomp = ppp->rcomp;
2268 rstate = ppp->rc_state;
2269 ppp->rc_state = NULL;
2270 ppp_unlock(ppp);
2271
2272 if (xstate) {
2273 xcomp->comp_free(xstate);
2274 module_put(xcomp->owner);
2275 }
2276 if (rstate) {
2277 rcomp->decomp_free(rstate);
2278 module_put(rcomp->owner);
2279 }
2280 }
2281
2282 /* List of compressors. */
2283 static LIST_HEAD(compressor_list);
2284 static DEFINE_SPINLOCK(compressor_list_lock);
2285
2286 struct compressor_entry {
2287 struct list_head list;
2288 struct compressor *comp;
2289 };
2290
2291 static struct compressor_entry *
2292 find_comp_entry(int proto)
2293 {
2294 struct compressor_entry *ce;
2295
2296 list_for_each_entry(ce, &compressor_list, list) {
2297 if (ce->comp->compress_proto == proto)
2298 return ce;
2299 }
2300 return NULL;
2301 }
2302
2303 /* Register a compressor */
2304 int
2305 ppp_register_compressor(struct compressor *cp)
2306 {
2307 struct compressor_entry *ce;
2308 int ret;
2309 spin_lock(&compressor_list_lock);
2310 ret = -EEXIST;
2311 if (find_comp_entry(cp->compress_proto))
2312 goto out;
2313 ret = -ENOMEM;
2314 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2315 if (!ce)
2316 goto out;
2317 ret = 0;
2318 ce->comp = cp;
2319 list_add(&ce->list, &compressor_list);
2320 out:
2321 spin_unlock(&compressor_list_lock);
2322 return ret;
2323 }
2324
2325 /* Unregister a compressor */
2326 void
2327 ppp_unregister_compressor(struct compressor *cp)
2328 {
2329 struct compressor_entry *ce;
2330
2331 spin_lock(&compressor_list_lock);
2332 ce = find_comp_entry(cp->compress_proto);
2333 if (ce && ce->comp == cp) {
2334 list_del(&ce->list);
2335 kfree(ce);
2336 }
2337 spin_unlock(&compressor_list_lock);
2338 }
2339
2340 /* Find a compressor. */
2341 static struct compressor *
2342 find_compressor(int type)
2343 {
2344 struct compressor_entry *ce;
2345 struct compressor *cp = NULL;
2346
2347 spin_lock(&compressor_list_lock);
2348 ce = find_comp_entry(type);
2349 if (ce) {
2350 cp = ce->comp;
2351 if (!try_module_get(cp->owner))
2352 cp = NULL;
2353 }
2354 spin_unlock(&compressor_list_lock);
2355 return cp;
2356 }
2357
2358 /*
2359 * Miscelleneous stuff.
2360 */
2361
2362 static void
2363 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2364 {
2365 struct slcompress *vj = ppp->vj;
2366
2367 memset(st, 0, sizeof(*st));
2368 st->p.ppp_ipackets = ppp->dev->stats.rx_packets;
2369 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2370 st->p.ppp_ibytes = ppp->dev->stats.rx_bytes;
2371 st->p.ppp_opackets = ppp->dev->stats.tx_packets;
2372 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2373 st->p.ppp_obytes = ppp->dev->stats.tx_bytes;
2374 if (!vj)
2375 return;
2376 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2377 st->vj.vjs_compressed = vj->sls_o_compressed;
2378 st->vj.vjs_searches = vj->sls_o_searches;
2379 st->vj.vjs_misses = vj->sls_o_misses;
2380 st->vj.vjs_errorin = vj->sls_i_error;
2381 st->vj.vjs_tossed = vj->sls_i_tossed;
2382 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2383 st->vj.vjs_compressedin = vj->sls_i_compressed;
2384 }
2385
2386 /*
2387 * Stuff for handling the lists of ppp units and channels
2388 * and for initialization.
2389 */
2390
2391 /*
2392 * Create a new ppp interface unit. Fails if it can't allocate memory
2393 * or if there is already a unit with the requested number.
2394 * unit == -1 means allocate a new number.
2395 */
2396 static struct ppp *
2397 ppp_create_interface(int unit, int *retp)
2398 {
2399 struct ppp *ppp;
2400 struct net_device *dev = NULL;
2401 int ret = -ENOMEM;
2402 int i;
2403
2404 dev = alloc_netdev(sizeof(struct ppp), "", ppp_setup);
2405 if (!dev)
2406 goto out1;
2407
2408 ppp = netdev_priv(dev);
2409 ppp->dev = dev;
2410 ppp->mru = PPP_MRU;
2411 init_ppp_file(&ppp->file, INTERFACE);
2412 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2413 for (i = 0; i < NUM_NP; ++i)
2414 ppp->npmode[i] = NPMODE_PASS;
2415 INIT_LIST_HEAD(&ppp->channels);
2416 spin_lock_init(&ppp->rlock);
2417 spin_lock_init(&ppp->wlock);
2418 #ifdef CONFIG_PPP_MULTILINK
2419 ppp->minseq = -1;
2420 skb_queue_head_init(&ppp->mrq);
2421 #endif /* CONFIG_PPP_MULTILINK */
2422
2423 ret = -EEXIST;
2424 mutex_lock(&all_ppp_mutex);
2425
2426 if (unit < 0) {
2427 unit = unit_get(&ppp_units_idr, ppp);
2428 if (unit < 0) {
2429 *retp = unit;
2430 goto out2;
2431 }
2432 } else {
2433 if (unit_find(&ppp_units_idr, unit))
2434 goto out2; /* unit already exists */
2435 else {
2436 /* darn, someone is cheating us? */
2437 *retp = -EINVAL;
2438 goto out2;
2439 }
2440 }
2441
2442 /* Initialize the new ppp unit */
2443 ppp->file.index = unit;
2444 sprintf(dev->name, "ppp%d", unit);
2445
2446 ret = register_netdev(dev);
2447 if (ret != 0) {
2448 unit_put(&ppp_units_idr, unit);
2449 printk(KERN_ERR "PPP: couldn't register device %s (%d)\n",
2450 dev->name, ret);
2451 goto out2;
2452 }
2453
2454 atomic_inc(&ppp_unit_count);
2455 mutex_unlock(&all_ppp_mutex);
2456
2457 *retp = 0;
2458 return ppp;
2459
2460 out2:
2461 mutex_unlock(&all_ppp_mutex);
2462 free_netdev(dev);
2463 out1:
2464 *retp = ret;
2465 return NULL;
2466 }
2467
2468 /*
2469 * Initialize a ppp_file structure.
2470 */
2471 static void
2472 init_ppp_file(struct ppp_file *pf, int kind)
2473 {
2474 pf->kind = kind;
2475 skb_queue_head_init(&pf->xq);
2476 skb_queue_head_init(&pf->rq);
2477 atomic_set(&pf->refcnt, 1);
2478 init_waitqueue_head(&pf->rwait);
2479 }
2480
2481 /*
2482 * Take down a ppp interface unit - called when the owning file
2483 * (the one that created the unit) is closed or detached.
2484 */
2485 static void ppp_shutdown_interface(struct ppp *ppp)
2486 {
2487 struct net_device *dev;
2488
2489 mutex_lock(&all_ppp_mutex);
2490 ppp_lock(ppp);
2491 dev = ppp->dev;
2492 ppp->dev = NULL;
2493 ppp_unlock(ppp);
2494 /* This will call dev_close() for us. */
2495 if (dev) {
2496 unregister_netdev(dev);
2497 free_netdev(dev);
2498 }
2499 unit_put(&ppp_units_idr, ppp->file.index);
2500 ppp->file.dead = 1;
2501 ppp->owner = NULL;
2502 wake_up_interruptible(&ppp->file.rwait);
2503 mutex_unlock(&all_ppp_mutex);
2504 }
2505
2506 /*
2507 * Free the memory used by a ppp unit. This is only called once
2508 * there are no channels connected to the unit and no file structs
2509 * that reference the unit.
2510 */
2511 static void ppp_destroy_interface(struct ppp *ppp)
2512 {
2513 atomic_dec(&ppp_unit_count);
2514
2515 if (!ppp->file.dead || ppp->n_channels) {
2516 /* "can't happen" */
2517 printk(KERN_ERR "ppp: destroying ppp struct %p but dead=%d "
2518 "n_channels=%d !\n", ppp, ppp->file.dead,
2519 ppp->n_channels);
2520 return;
2521 }
2522
2523 ppp_ccp_closed(ppp);
2524 if (ppp->vj) {
2525 slhc_free(ppp->vj);
2526 ppp->vj = NULL;
2527 }
2528 skb_queue_purge(&ppp->file.xq);
2529 skb_queue_purge(&ppp->file.rq);
2530 #ifdef CONFIG_PPP_MULTILINK
2531 skb_queue_purge(&ppp->mrq);
2532 #endif /* CONFIG_PPP_MULTILINK */
2533 #ifdef CONFIG_PPP_FILTER
2534 kfree(ppp->pass_filter);
2535 ppp->pass_filter = NULL;
2536 kfree(ppp->active_filter);
2537 ppp->active_filter = NULL;
2538 #endif /* CONFIG_PPP_FILTER */
2539
2540 if (ppp->xmit_pending)
2541 kfree_skb(ppp->xmit_pending);
2542
2543 kfree(ppp);
2544 }
2545
2546 /*
2547 * Locate an existing ppp unit.
2548 * The caller should have locked the all_ppp_mutex.
2549 */
2550 static struct ppp *
2551 ppp_find_unit(int unit)
2552 {
2553 return unit_find(&ppp_units_idr, unit);
2554 }
2555
2556 /*
2557 * Locate an existing ppp channel.
2558 * The caller should have locked the all_channels_lock.
2559 * First we look in the new_channels list, then in the
2560 * all_channels list. If found in the new_channels list,
2561 * we move it to the all_channels list. This is for speed
2562 * when we have a lot of channels in use.
2563 */
2564 static struct channel *
2565 ppp_find_channel(int unit)
2566 {
2567 struct channel *pch;
2568
2569 list_for_each_entry(pch, &new_channels, list) {
2570 if (pch->file.index == unit) {
2571 list_move(&pch->list, &all_channels);
2572 return pch;
2573 }
2574 }
2575 list_for_each_entry(pch, &all_channels, list) {
2576 if (pch->file.index == unit)
2577 return pch;
2578 }
2579 return NULL;
2580 }
2581
2582 /*
2583 * Connect a PPP channel to a PPP interface unit.
2584 */
2585 static int
2586 ppp_connect_channel(struct channel *pch, int unit)
2587 {
2588 struct ppp *ppp;
2589 int ret = -ENXIO;
2590 int hdrlen;
2591
2592 mutex_lock(&all_ppp_mutex);
2593 ppp = ppp_find_unit(unit);
2594 if (!ppp)
2595 goto out;
2596 write_lock_bh(&pch->upl);
2597 ret = -EINVAL;
2598 if (pch->ppp)
2599 goto outl;
2600
2601 ppp_lock(ppp);
2602 if (pch->file.hdrlen > ppp->file.hdrlen)
2603 ppp->file.hdrlen = pch->file.hdrlen;
2604 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2605 if (ppp->dev && hdrlen > ppp->dev->hard_header_len)
2606 ppp->dev->hard_header_len = hdrlen;
2607 list_add_tail(&pch->clist, &ppp->channels);
2608 ++ppp->n_channels;
2609 pch->ppp = ppp;
2610 atomic_inc(&ppp->file.refcnt);
2611 ppp_unlock(ppp);
2612 ret = 0;
2613
2614 outl:
2615 write_unlock_bh(&pch->upl);
2616 out:
2617 mutex_unlock(&all_ppp_mutex);
2618 return ret;
2619 }
2620
2621 /*
2622 * Disconnect a channel from its ppp unit.
2623 */
2624 static int
2625 ppp_disconnect_channel(struct channel *pch)
2626 {
2627 struct ppp *ppp;
2628 int err = -EINVAL;
2629
2630 write_lock_bh(&pch->upl);
2631 ppp = pch->ppp;
2632 pch->ppp = NULL;
2633 write_unlock_bh(&pch->upl);
2634 if (ppp) {
2635 /* remove it from the ppp unit's list */
2636 ppp_lock(ppp);
2637 list_del(&pch->clist);
2638 if (--ppp->n_channels == 0)
2639 wake_up_interruptible(&ppp->file.rwait);
2640 ppp_unlock(ppp);
2641 if (atomic_dec_and_test(&ppp->file.refcnt))
2642 ppp_destroy_interface(ppp);
2643 err = 0;
2644 }
2645 return err;
2646 }
2647
2648 /*
2649 * Free up the resources used by a ppp channel.
2650 */
2651 static void ppp_destroy_channel(struct channel *pch)
2652 {
2653 atomic_dec(&channel_count);
2654
2655 if (!pch->file.dead) {
2656 /* "can't happen" */
2657 printk(KERN_ERR "ppp: destroying undead channel %p !\n",
2658 pch);
2659 return;
2660 }
2661 skb_queue_purge(&pch->file.xq);
2662 skb_queue_purge(&pch->file.rq);
2663 kfree(pch);
2664 }
2665
2666 static void __exit ppp_cleanup(void)
2667 {
2668 /* should never happen */
2669 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2670 printk(KERN_ERR "PPP: removing module but units remain!\n");
2671 unregister_chrdev(PPP_MAJOR, "ppp");
2672 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
2673 class_destroy(ppp_class);
2674 idr_destroy(&ppp_units_idr);
2675 }
2676
2677 /*
2678 * Units handling. Caller must protect concurrent access
2679 * by holding all_ppp_mutex
2680 */
2681
2682 /* get new free unit number and associate pointer with it */
2683 static int unit_get(struct idr *p, void *ptr)
2684 {
2685 int unit, err;
2686
2687 again:
2688 if (idr_pre_get(p, GFP_KERNEL) == 0) {
2689 printk(KERN_ERR "Out of memory expanding drawable idr\n");
2690 return -ENOMEM;
2691 }
2692
2693 err = idr_get_new_above(p, ptr, 0, &unit);
2694 if (err == -EAGAIN)
2695 goto again;
2696
2697 return unit;
2698 }
2699
2700 /* put unit number back to a pool */
2701 static void unit_put(struct idr *p, int n)
2702 {
2703 idr_remove(p, n);
2704 }
2705
2706 /* get pointer associated with the number */
2707 static void *unit_find(struct idr *p, int n)
2708 {
2709 return idr_find(p, n);
2710 }
2711
2712 /* Module/initialization stuff */
2713
2714 module_init(ppp_init);
2715 module_exit(ppp_cleanup);
2716
2717 EXPORT_SYMBOL(ppp_register_channel);
2718 EXPORT_SYMBOL(ppp_unregister_channel);
2719 EXPORT_SYMBOL(ppp_channel_index);
2720 EXPORT_SYMBOL(ppp_unit_number);
2721 EXPORT_SYMBOL(ppp_input);
2722 EXPORT_SYMBOL(ppp_input_error);
2723 EXPORT_SYMBOL(ppp_output_wakeup);
2724 EXPORT_SYMBOL(ppp_register_compressor);
2725 EXPORT_SYMBOL(ppp_unregister_compressor);
2726 MODULE_LICENSE("GPL");
2727 MODULE_ALIAS_CHARDEV_MAJOR(PPP_MAJOR);
2728 MODULE_ALIAS("/dev/ppp");
Support for the Chinese Samsung S3C2440 based development boards