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[net-next-2.6.git] / drivers / net / ppp_generic.c
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1da177e4
LT		 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/config.h>
26#include <linux/module.h>
27#include <linux/kernel.h>
28#include <linux/kmod.h>
29#include <linux/init.h>
30#include <linux/list.h>
31#include <linux/devfs_fs_kernel.h>
32#include <linux/netdevice.h>
33#include <linux/poll.h>
34#include <linux/ppp_defs.h>
35#include <linux/filter.h>
36#include <linux/if_ppp.h>
37#include <linux/ppp_channel.h>
38#include <linux/ppp-comp.h>
39#include <linux/skbuff.h>
40#include <linux/rtnetlink.h>
41#include <linux/if_arp.h>
42#include <linux/ip.h>
43#include <linux/tcp.h>
44#include <linux/spinlock.h>
45#include <linux/smp_lock.h>
46#include <linux/rwsem.h>
47#include <linux/stddef.h>
48#include <linux/device.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 */
74struct 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) ((X *)((char *)(pf) - offsetof(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#define ROUNDUP(n, x) (((n) + (x) - 1) / (x))
93
94/*
95 * Data structure describing one ppp unit.
96 * A ppp unit corresponds to a ppp network interface device
97 * and represents a multilink bundle.
98 * It can have 0 or more ppp channels connected to it.
99 */
100struct ppp {
101 struct ppp_file file; /* stuff for read/write/poll 0 */
102 struct file *owner; /* file that owns this unit 48 */
103 struct list_head channels; /* list of attached channels 4c */
104 int n_channels; /* how many channels are attached 54 */
105 spinlock_t rlock; /* lock for receive side 58 */
106 spinlock_t wlock; /* lock for transmit side 5c */
107 int mru; /* max receive unit 60 */
108 unsigned int flags; /* control bits 64 */
109 unsigned int xstate; /* transmit state bits 68 */
110 unsigned int rstate; /* receive state bits 6c */
111 int debug; /* debug flags 70 */
112 struct slcompress *vj; /* state for VJ header compression */
113 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
114 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
115 struct compressor *xcomp; /* transmit packet compressor 8c */
116 void *xc_state; /* its internal state 90 */
117 struct compressor *rcomp; /* receive decompressor 94 */
118 void *rc_state; /* its internal state 98 */
119 unsigned long last_xmit; /* jiffies when last pkt sent 9c */
120 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
121 struct net_device *dev; /* network interface device a4 */
122#ifdef CONFIG_PPP_MULTILINK
123 int nxchan; /* next channel to send something on */
124 u32 nxseq; /* next sequence number to send */
125 int mrru; /* MP: max reconst. receive unit */
126 u32 nextseq; /* MP: seq no of next packet */
127 u32 minseq; /* MP: min of most recent seqnos */
128 struct sk_buff_head mrq; /* MP: receive reconstruction queue */
129#endif /* CONFIG_PPP_MULTILINK */
130 struct net_device_stats stats; /* statistics */
131#ifdef CONFIG_PPP_FILTER
132 struct sock_filter *pass_filter; /* filter for packets to pass */
133 struct sock_filter *active_filter;/* filter for pkts to reset idle */
134 unsigned pass_len, active_len;
135#endif /* CONFIG_PPP_FILTER */
136};
137
138/*
139 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
140 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP.
141 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
142 * Bits in xstate: SC_COMP_RUN
143 */
144#define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
145 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
146 |SC_COMP_TCP|SC_REJ_COMP_TCP)
147
148/*
149 * Private data structure for each channel.
150 * This includes the data structure used for multilink.
151 */
152struct channel {
153 struct ppp_file file; /* stuff for read/write/poll */
154 struct list_head list; /* link in all/new_channels list */
155 struct ppp_channel *chan; /* public channel data structure */
156 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
157 spinlock_t downl; /* protects `chan', file.xq dequeue */
158 struct ppp *ppp; /* ppp unit we're connected to */
159 struct list_head clist; /* link in list of channels per unit */
160 rwlock_t upl; /* protects `ppp' */
161#ifdef CONFIG_PPP_MULTILINK
162 u8 avail; /* flag used in multilink stuff */
163 u8 had_frag; /* >= 1 fragments have been sent */
164 u32 lastseq; /* MP: last sequence # received */
165#endif /* CONFIG_PPP_MULTILINK */
166};
167
168/*
169 * SMP locking issues:
170 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
171 * list and the ppp.n_channels field, you need to take both locks
172 * before you modify them.
173 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
174 * channel.downl.
175 */
176
177/*
178 * A cardmap represents a mapping from unsigned integers to pointers,
179 * and provides a fast "find lowest unused number" operation.
180 * It uses a broad (32-way) tree with a bitmap at each level.
181 * It is designed to be space-efficient for small numbers of entries
182 * and time-efficient for large numbers of entries.
183 */
184#define CARDMAP_ORDER 5
185#define CARDMAP_WIDTH (1U << CARDMAP_ORDER)
186#define CARDMAP_MASK (CARDMAP_WIDTH - 1)
187
188struct cardmap {
189 int shift;
190 unsigned long inuse;
191 struct cardmap *parent;
192 void *ptr[CARDMAP_WIDTH];
193};
194static void *cardmap_get(struct cardmap *map, unsigned int nr);
195static void cardmap_set(struct cardmap **map, unsigned int nr, void *ptr);
196static unsigned int cardmap_find_first_free(struct cardmap *map);
197static void cardmap_destroy(struct cardmap **map);
198
199/*
200 * all_ppp_sem protects the all_ppp_units mapping.
201 * It also ensures that finding a ppp unit in the all_ppp_units map
202 * and updating its file.refcnt field is atomic.
203 */
204static DECLARE_MUTEX(all_ppp_sem);
205static struct cardmap *all_ppp_units;
206static atomic_t ppp_unit_count = ATOMIC_INIT(0);
207
208/*
209 * all_channels_lock protects all_channels and last_channel_index,
210 * and the atomicity of find a channel and updating its file.refcnt
211 * field.
212 */
213static DEFINE_SPINLOCK(all_channels_lock);
214static LIST_HEAD(all_channels);
215static LIST_HEAD(new_channels);
216static int last_channel_index;
217static atomic_t channel_count = ATOMIC_INIT(0);
218
219/* Get the PPP protocol number from a skb */
220#define PPP_PROTO(skb) (((skb)->data[0] << 8) + (skb)->data[1])
221
222/* We limit the length of ppp->file.rq to this (arbitrary) value */
223#define PPP_MAX_RQLEN 32
224
225/*
226 * Maximum number of multilink fragments queued up.
227 * This has to be large enough to cope with the maximum latency of
228 * the slowest channel relative to the others. Strictly it should
229 * depend on the number of channels and their characteristics.
230 */
231#define PPP_MP_MAX_QLEN 128
232
233/* Multilink header bits. */
234#define B 0x80 /* this fragment begins a packet */
235#define E 0x40 /* this fragment ends a packet */
236
237/* Compare multilink sequence numbers (assumed to be 32 bits wide) */
238#define seq_before(a, b) ((s32)((a) - (b)) < 0)
239#define seq_after(a, b) ((s32)((a) - (b)) > 0)
240
241/* Prototypes. */
242static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file,
243 unsigned int cmd, unsigned long arg);
244static void ppp_xmit_process(struct ppp *ppp);
245static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
246static void ppp_push(struct ppp *ppp);
247static void ppp_channel_push(struct channel *pch);
248static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
249 struct channel *pch);
250static void ppp_receive_error(struct ppp *ppp);
251static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
252static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
253 struct sk_buff *skb);
254#ifdef CONFIG_PPP_MULTILINK
255static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
256 struct channel *pch);
257static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
258static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
259static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
260#endif /* CONFIG_PPP_MULTILINK */
261static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
262static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
263static void ppp_ccp_closed(struct ppp *ppp);
264static struct compressor *find_compressor(int type);
265static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
266static struct ppp *ppp_create_interface(int unit, int *retp);
267static void init_ppp_file(struct ppp_file *pf, int kind);
268static void ppp_shutdown_interface(struct ppp *ppp);
269static void ppp_destroy_interface(struct ppp *ppp);
270static struct ppp *ppp_find_unit(int unit);
271static struct channel *ppp_find_channel(int unit);
272static int ppp_connect_channel(struct channel *pch, int unit);
273static int ppp_disconnect_channel(struct channel *pch);
274static void ppp_destroy_channel(struct channel *pch);
275
276static struct class_simple *ppp_class;
277
278/* Translates a PPP protocol number to a NP index (NP == network protocol) */
279static inline int proto_to_npindex(int proto)
280{
281 switch (proto) {
282 case PPP_IP:
283 return NP_IP;
284 case PPP_IPV6:
285 return NP_IPV6;
286 case PPP_IPX:
287 return NP_IPX;
288 case PPP_AT:
289 return NP_AT;
290 case PPP_MPLS_UC:
291 return NP_MPLS_UC;
292 case PPP_MPLS_MC:
293 return NP_MPLS_MC;
294 }
295 return -EINVAL;
296}
297
298/* Translates an NP index into a PPP protocol number */
299static const int npindex_to_proto[NUM_NP] = {
300 PPP_IP,
301 PPP_IPV6,
302 PPP_IPX,
303 PPP_AT,
304 PPP_MPLS_UC,
305 PPP_MPLS_MC,
306};
307
308/* Translates an ethertype into an NP index */
309static inline int ethertype_to_npindex(int ethertype)
310{
311 switch (ethertype) {
312 case ETH_P_IP:
313 return NP_IP;
314 case ETH_P_IPV6:
315 return NP_IPV6;
316 case ETH_P_IPX:
317 return NP_IPX;
318 case ETH_P_PPPTALK:
319 case ETH_P_ATALK:
320 return NP_AT;
321 case ETH_P_MPLS_UC:
322 return NP_MPLS_UC;
323 case ETH_P_MPLS_MC:
324 return NP_MPLS_MC;
325 }
326 return -1;
327}
328
329/* Translates an NP index into an ethertype */
330static const int npindex_to_ethertype[NUM_NP] = {
331 ETH_P_IP,
332 ETH_P_IPV6,
333 ETH_P_IPX,
334 ETH_P_PPPTALK,
335 ETH_P_MPLS_UC,
336 ETH_P_MPLS_MC,
337};
338
339/*
340 * Locking shorthand.
341 */
342#define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
343#define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
344#define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
345#define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
346#define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
347 ppp_recv_lock(ppp); } while (0)
348#define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
349 ppp_xmit_unlock(ppp); } while (0)
350
351/*
352 * /dev/ppp device routines.
353 * The /dev/ppp device is used by pppd to control the ppp unit.
354 * It supports the read, write, ioctl and poll functions.
355 * Open instances of /dev/ppp can be in one of three states:
356 * unattached, attached to a ppp unit, or attached to a ppp channel.
357 */
358static int ppp_open(struct inode *inode, struct file *file)
359{
360 /*
361 * This could (should?) be enforced by the permissions on /dev/ppp.
362 */
363 if (!capable(CAP_NET_ADMIN))
364 return -EPERM;
365 return 0;
366}
367
368static int ppp_release(struct inode *inode, struct file *file)
369{
370 struct ppp_file *pf = file->private_data;
371 struct ppp *ppp;
372
373 if (pf != 0) {
374 file->private_data = NULL;
375 if (pf->kind == INTERFACE) {
376 ppp = PF_TO_PPP(pf);
377 if (file == ppp->owner)
378 ppp_shutdown_interface(ppp);
379 }
380 if (atomic_dec_and_test(&pf->refcnt)) {
381 switch (pf->kind) {
382 case INTERFACE:
383 ppp_destroy_interface(PF_TO_PPP(pf));
384 break;
385 case CHANNEL:
386 ppp_destroy_channel(PF_TO_CHANNEL(pf));
387 break;
388 }
389 }
390 }
391 return 0;
392}
393
394static ssize_t ppp_read(struct file *file, char __user *buf,
395 size_t count, loff_t *ppos)
396{
397 struct ppp_file *pf = file->private_data;
398 DECLARE_WAITQUEUE(wait, current);
399 ssize_t ret;
400 struct sk_buff *skb = NULL;
401
402 ret = count;
403
404 if (pf == 0)
405 return -ENXIO;
406 add_wait_queue(&pf->rwait, &wait);
407 for (;;) {
408 set_current_state(TASK_INTERRUPTIBLE);
409 skb = skb_dequeue(&pf->rq);
410 if (skb)
411 break;
412 ret = 0;
413 if (pf->dead)
414 break;
415 if (pf->kind == INTERFACE) {
416 /*
417 * Return 0 (EOF) on an interface that has no
418 * channels connected, unless it is looping
419 * network traffic (demand mode).
420 */
421 struct ppp *ppp = PF_TO_PPP(pf);
422 if (ppp->n_channels == 0
423 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
424 break;
425 }
426 ret = -EAGAIN;
427 if (file->f_flags & O_NONBLOCK)
428 break;
429 ret = -ERESTARTSYS;
430 if (signal_pending(current))
431 break;
432 schedule();
433 }
434 set_current_state(TASK_RUNNING);
435 remove_wait_queue(&pf->rwait, &wait);
436
437 if (skb == 0)
438 goto out;
439
440 ret = -EOVERFLOW;
441 if (skb->len > count)
442 goto outf;
443 ret = -EFAULT;
444 if (copy_to_user(buf, skb->data, skb->len))
445 goto outf;
446 ret = skb->len;
447
448 outf:
449 kfree_skb(skb);
450 out:
451 return ret;
452}
453
454static ssize_t ppp_write(struct file *file, const char __user *buf,
455 size_t count, loff_t *ppos)
456{
457 struct ppp_file *pf = file->private_data;
458 struct sk_buff *skb;
459 ssize_t ret;
460
461 if (pf == 0)
462 return -ENXIO;
463 ret = -ENOMEM;
464 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
465 if (skb == 0)
466 goto out;
467 skb_reserve(skb, pf->hdrlen);
468 ret = -EFAULT;
469 if (copy_from_user(skb_put(skb, count), buf, count)) {
470 kfree_skb(skb);
471 goto out;
472 }
473
474 skb_queue_tail(&pf->xq, skb);
475
476 switch (pf->kind) {
477 case INTERFACE:
478 ppp_xmit_process(PF_TO_PPP(pf));
479 break;
480 case CHANNEL:
481 ppp_channel_push(PF_TO_CHANNEL(pf));
482 break;
483 }
484
485 ret = count;
486
487 out:
488 return ret;
489}
490
491/* No kernel lock - fine */
492static unsigned int ppp_poll(struct file *file, poll_table *wait)
493{
494 struct ppp_file *pf = file->private_data;
495 unsigned int mask;
496
497 if (pf == 0)
498 return 0;
499 poll_wait(file, &pf->rwait, wait);
500 mask = POLLOUT | POLLWRNORM;
501 if (skb_peek(&pf->rq) != 0)
502 mask |= POLLIN | POLLRDNORM;
503 if (pf->dead)
504 mask |= POLLHUP;
505 else if (pf->kind == INTERFACE) {
506 /* see comment in ppp_read */
507 struct ppp *ppp = PF_TO_PPP(pf);
508 if (ppp->n_channels == 0
509 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
510 mask |= POLLIN | POLLRDNORM;
511 }
512
513 return mask;
514}
515
516#ifdef CONFIG_PPP_FILTER
517static int get_filter(void __user *arg, struct sock_filter **p)
518{
519 struct sock_fprog uprog;
520 struct sock_filter *code = NULL;
521 int len, err;
522
523 if (copy_from_user(&uprog, arg, sizeof(uprog)))
524 return -EFAULT;
525
526 if (uprog.len > BPF_MAXINSNS)
527 return -EINVAL;
528
529 if (!uprog.len) {
530 *p = NULL;
531 return 0;
532 }
533
534 len = uprog.len * sizeof(struct sock_filter);
535 code = kmalloc(len, GFP_KERNEL);
536 if (code == NULL)
537 return -ENOMEM;
538
539 if (copy_from_user(code, uprog.filter, len)) {
540 kfree(code);
541 return -EFAULT;
542 }
543
544 err = sk_chk_filter(code, uprog.len);
545 if (err) {
546 kfree(code);
547 return err;
548 }
549
550 *p = code;
551 return uprog.len;
552}
553#endif /* CONFIG_PPP_FILTER */
554
555static int ppp_ioctl(struct inode *inode, struct file *file,
556 unsigned int cmd, unsigned long arg)
557{
558 struct ppp_file *pf = file->private_data;
559 struct ppp *ppp;
560 int err = -EFAULT, val, val2, i;
561 struct ppp_idle idle;
562 struct npioctl npi;
563 int unit, cflags;
564 struct slcompress *vj;
565 void __user *argp = (void __user *)arg;
566 int __user *p = argp;
567
568 if (pf == 0)
569 return ppp_unattached_ioctl(pf, file, cmd, arg);
570
571 if (cmd == PPPIOCDETACH) {
572 /*
573 * We have to be careful here... if the file descriptor
574 * has been dup'd, we could have another process in the
575 * middle of a poll using the same file *, so we had
576 * better not free the interface data structures -
577 * instead we fail the ioctl. Even in this case, we
578 * shut down the interface if we are the owner of it.
579 * Actually, we should get rid of PPPIOCDETACH, userland
580 * (i.e. pppd) could achieve the same effect by closing
581 * this fd and reopening /dev/ppp.
582 */
583 err = -EINVAL;
584 if (pf->kind == INTERFACE) {
585 ppp = PF_TO_PPP(pf);
586 if (file == ppp->owner)
587 ppp_shutdown_interface(ppp);
588 }
589 if (atomic_read(&file->f_count) <= 2) {
590 ppp_release(inode, file);
591 err = 0;
592 } else
593 printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%d\n",
594 atomic_read(&file->f_count));
595 return err;
596 }
597
598 if (pf->kind == CHANNEL) {
599 struct channel *pch = PF_TO_CHANNEL(pf);
600 struct ppp_channel *chan;
601
602 switch (cmd) {
603 case PPPIOCCONNECT:
604 if (get_user(unit, p))
605 break;
606 err = ppp_connect_channel(pch, unit);
607 break;
608
609 case PPPIOCDISCONN:
610 err = ppp_disconnect_channel(pch);
611 break;
612
613 default:
614 down_read(&pch->chan_sem);
615 chan = pch->chan;
616 err = -ENOTTY;
617 if (chan && chan->ops->ioctl)
618 err = chan->ops->ioctl(chan, cmd, arg);
619 up_read(&pch->chan_sem);
620 }
621 return err;
622 }
623
624 if (pf->kind != INTERFACE) {
625 /* can't happen */
626 printk(KERN_ERR "PPP: not interface or channel??\n");
627 return -EINVAL;
628 }
629
630 ppp = PF_TO_PPP(pf);
631 switch (cmd) {
632 case PPPIOCSMRU:
633 if (get_user(val, p))
634 break;
635 ppp->mru = val;
636 err = 0;
637 break;
638
639 case PPPIOCSFLAGS:
640 if (get_user(val, p))
641 break;
642 ppp_lock(ppp);
643 cflags = ppp->flags & ~val;
644 ppp->flags = val & SC_FLAG_BITS;
645 ppp_unlock(ppp);
646 if (cflags & SC_CCP_OPEN)
647 ppp_ccp_closed(ppp);
648 err = 0;
649 break;
650
651 case PPPIOCGFLAGS:
652 val = ppp->flags | ppp->xstate | ppp->rstate;
653 if (put_user(val, p))
654 break;
655 err = 0;
656 break;
657
658 case PPPIOCSCOMPRESS:
659 err = ppp_set_compress(ppp, arg);
660 break;
661
662 case PPPIOCGUNIT:
663 if (put_user(ppp->file.index, p))
664 break;
665 err = 0;
666 break;
667
668 case PPPIOCSDEBUG:
669 if (get_user(val, p))
670 break;
671 ppp->debug = val;
672 err = 0;
673 break;
674
675 case PPPIOCGDEBUG:
676 if (put_user(ppp->debug, p))
677 break;
678 err = 0;
679 break;
680
681 case PPPIOCGIDLE:
682 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
683 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
684 if (copy_to_user(argp, &idle, sizeof(idle)))
685 break;
686 err = 0;
687 break;
688
689 case PPPIOCSMAXCID:
690 if (get_user(val, p))
691 break;
692 val2 = 15;
693 if ((val >> 16) != 0) {
694 val2 = val >> 16;
695 val &= 0xffff;
696 }
697 vj = slhc_init(val2+1, val+1);
698 if (vj == 0) {
699 printk(KERN_ERR "PPP: no memory (VJ compressor)\n");
700 err = -ENOMEM;
701 break;
702 }
703 ppp_lock(ppp);
704 if (ppp->vj != 0)
705 slhc_free(ppp->vj);
706 ppp->vj = vj;
707 ppp_unlock(ppp);
708 err = 0;
709 break;
710
711 case PPPIOCGNPMODE:
712 case PPPIOCSNPMODE:
713 if (copy_from_user(&npi, argp, sizeof(npi)))
714 break;
715 err = proto_to_npindex(npi.protocol);
716 if (err < 0)
717 break;
718 i = err;
719 if (cmd == PPPIOCGNPMODE) {
720 err = -EFAULT;
721 npi.mode = ppp->npmode[i];
722 if (copy_to_user(argp, &npi, sizeof(npi)))
723 break;
724 } else {
725 ppp->npmode[i] = npi.mode;
726 /* we may be able to transmit more packets now (??) */
727 netif_wake_queue(ppp->dev);
728 }
729 err = 0;
730 break;
731
732#ifdef CONFIG_PPP_FILTER
733 case PPPIOCSPASS:
734 {
735 struct sock_filter *code;
736 err = get_filter(argp, &code);
737 if (err >= 0) {
738 ppp_lock(ppp);
739 kfree(ppp->pass_filter);
740 ppp->pass_filter = code;
741 ppp->pass_len = err;
742 ppp_unlock(ppp);
743 err = 0;
744 }
745 break;
746 }
747 case PPPIOCSACTIVE:
748 {
749 struct sock_filter *code;
750 err = get_filter(argp, &code);
751 if (err >= 0) {
752 ppp_lock(ppp);
753 kfree(ppp->active_filter);
754 ppp->active_filter = code;
755 ppp->active_len = err;
756 ppp_unlock(ppp);
757 err = 0;
758 }
759 break;
760 }
761#endif /* CONFIG_PPP_FILTER */
762
763#ifdef CONFIG_PPP_MULTILINK
764 case PPPIOCSMRRU:
765 if (get_user(val, p))
766 break;
767 ppp_recv_lock(ppp);
768 ppp->mrru = val;
769 ppp_recv_unlock(ppp);
770 err = 0;
771 break;
772#endif /* CONFIG_PPP_MULTILINK */
773
774 default:
775 err = -ENOTTY;
776 }
777
778 return err;
779}
780
781static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file,
782 unsigned int cmd, unsigned long arg)
783{
784 int unit, err = -EFAULT;
785 struct ppp *ppp;
786 struct channel *chan;
787 int __user *p = (int __user *)arg;
788
789 switch (cmd) {
790 case PPPIOCNEWUNIT:
791 /* Create a new ppp unit */
792 if (get_user(unit, p))
793 break;
794 ppp = ppp_create_interface(unit, &err);
795 if (ppp == 0)
796 break;
797 file->private_data = &ppp->file;
798 ppp->owner = file;
799 err = -EFAULT;
800 if (put_user(ppp->file.index, p))
801 break;
802 err = 0;
803 break;
804
805 case PPPIOCATTACH:
806 /* Attach to an existing ppp unit */
807 if (get_user(unit, p))
808 break;
809 down(&all_ppp_sem);
810 err = -ENXIO;
811 ppp = ppp_find_unit(unit);
812 if (ppp != 0) {
813 atomic_inc(&ppp->file.refcnt);
814 file->private_data = &ppp->file;
815 err = 0;
816 }
817 up(&all_ppp_sem);
818 break;
819
820 case PPPIOCATTCHAN:
821 if (get_user(unit, p))
822 break;
823 spin_lock_bh(&all_channels_lock);
824 err = -ENXIO;
825 chan = ppp_find_channel(unit);
826 if (chan != 0) {
827 atomic_inc(&chan->file.refcnt);
828 file->private_data = &chan->file;
829 err = 0;
830 }
831 spin_unlock_bh(&all_channels_lock);
832 break;
833
834 default:
835 err = -ENOTTY;
836 }
837 return err;
838}
839
840static struct file_operations ppp_device_fops = {
841 .owner = THIS_MODULE,
842 .read = ppp_read,
843 .write = ppp_write,
844 .poll = ppp_poll,
845 .ioctl = ppp_ioctl,
846 .open = ppp_open,
847 .release = ppp_release
848};
849
850#define PPP_MAJOR 108
851
852/* Called at boot time if ppp is compiled into the kernel,
853 or at module load time (from init_module) if compiled as a module. */
854static int __init ppp_init(void)
855{
856 int err;
857
858 printk(KERN_INFO "PPP generic driver version " PPP_VERSION "\n");
859 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
860 if (!err) {
861 ppp_class = class_simple_create(THIS_MODULE, "ppp");
862 if (IS_ERR(ppp_class)) {
863 err = PTR_ERR(ppp_class);
864 goto out_chrdev;
865 }
866 class_simple_device_add(ppp_class, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
867 err = devfs_mk_cdev(MKDEV(PPP_MAJOR, 0),
868 S_IFCHR|S_IRUSR|S_IWUSR, "ppp");
869 if (err)
870 goto out_class;
871 }
872
873out:
874 if (err)
875 printk(KERN_ERR "failed to register PPP device (%d)\n", err);
876 return err;
877
878out_class:
879 class_simple_device_remove(MKDEV(PPP_MAJOR,0));
880 class_simple_destroy(ppp_class);
881out_chrdev:
882 unregister_chrdev(PPP_MAJOR, "ppp");
883 goto out;
884}
885
886/*
887 * Network interface unit routines.
888 */
889static int
890ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
891{
892 struct ppp *ppp = (struct ppp *) dev->priv;
893 int npi, proto;
894 unsigned char *pp;
895
896 npi = ethertype_to_npindex(ntohs(skb->protocol));
897 if (npi < 0)
898 goto outf;
899
900 /* Drop, accept or reject the packet */
901 switch (ppp->npmode[npi]) {
902 case NPMODE_PASS:
903 break;
904 case NPMODE_QUEUE:
905 /* it would be nice to have a way to tell the network
906 system to queue this one up for later. */
907 goto outf;
908 case NPMODE_DROP:
909 case NPMODE_ERROR:
910 goto outf;
911 }
912
913 /* Put the 2-byte PPP protocol number on the front,
914 making sure there is room for the address and control fields. */
915 if (skb_headroom(skb) < PPP_HDRLEN) {
916 struct sk_buff *ns;
917
918 ns = alloc_skb(skb->len + dev->hard_header_len, GFP_ATOMIC);
919 if (ns == 0)
920 goto outf;
921 skb_reserve(ns, dev->hard_header_len);
922 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
923 kfree_skb(skb);
924 skb = ns;
925 }
926 pp = skb_push(skb, 2);
927 proto = npindex_to_proto[npi];
928 pp[0] = proto >> 8;
929 pp[1] = proto;
930
931 netif_stop_queue(dev);
932 skb_queue_tail(&ppp->file.xq, skb);
933 ppp_xmit_process(ppp);
934 return 0;
935
936 outf:
937 kfree_skb(skb);
938 ++ppp->stats.tx_dropped;
939 return 0;
940}
941
942static struct net_device_stats *
943ppp_net_stats(struct net_device *dev)
944{
945 struct ppp *ppp = (struct ppp *) dev->priv;
946
947 return &ppp->stats;
948}
949
950static int
951ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
952{
953 struct ppp *ppp = dev->priv;
954 int err = -EFAULT;
955 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
956 struct ppp_stats stats;
957 struct ppp_comp_stats cstats;
958 char *vers;
959
960 switch (cmd) {
961 case SIOCGPPPSTATS:
962 ppp_get_stats(ppp, &stats);
963 if (copy_to_user(addr, &stats, sizeof(stats)))
964 break;
965 err = 0;
966 break;
967
968 case SIOCGPPPCSTATS:
969 memset(&cstats, 0, sizeof(cstats));
970 if (ppp->xc_state != 0)
971 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
972 if (ppp->rc_state != 0)
973 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
974 if (copy_to_user(addr, &cstats, sizeof(cstats)))
975 break;
976 err = 0;
977 break;
978
979 case SIOCGPPPVER:
980 vers = PPP_VERSION;
981 if (copy_to_user(addr, vers, strlen(vers) + 1))
982 break;
983 err = 0;
984 break;
985
986 default:
987 err = -EINVAL;
988 }
989
990 return err;
991}
992
993static void ppp_setup(struct net_device *dev)
994{
995 dev->hard_header_len = PPP_HDRLEN;
996 dev->mtu = PPP_MTU;
997 dev->addr_len = 0;
998 dev->tx_queue_len = 3;
999 dev->type = ARPHRD_PPP;
1000 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1001}
1002
1003/*
1004 * Transmit-side routines.
1005 */
1006
1007/*
1008 * Called to do any work queued up on the transmit side
1009 * that can now be done.
1010 */
1011static void
1012ppp_xmit_process(struct ppp *ppp)
1013{
1014 struct sk_buff *skb;
1015
1016 ppp_xmit_lock(ppp);
1017 if (ppp->dev != 0) {
1018 ppp_push(ppp);
1019 while (ppp->xmit_pending == 0
1020 && (skb = skb_dequeue(&ppp->file.xq)) != 0)
1021 ppp_send_frame(ppp, skb);
1022 /* If there's no work left to do, tell the core net
1023 code that we can accept some more. */
1024 if (ppp->xmit_pending == 0 && skb_peek(&ppp->file.xq) == 0)
1025 netif_wake_queue(ppp->dev);
1026 }
1027 ppp_xmit_unlock(ppp);
1028}
1029
1030/*
1031 * Compress and send a frame.
1032 * The caller should have locked the xmit path,
1033 * and xmit_pending should be 0.
1034 */
1035static void
1036ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1037{
1038 int proto = PPP_PROTO(skb);
1039 struct sk_buff *new_skb;
1040 int len;
1041 unsigned char *cp;
1042
1043 if (proto < 0x8000) {
1044#ifdef CONFIG_PPP_FILTER
1045 /* check if we should pass this packet */
1046 /* the filter instructions are constructed assuming
1047 a four-byte PPP header on each packet */
1048 *skb_push(skb, 2) = 1;
1049 if (ppp->pass_filter
1050 && sk_run_filter(skb, ppp->pass_filter,
1051 ppp->pass_len) == 0) {
1052 if (ppp->debug & 1)
1053 printk(KERN_DEBUG "PPP: outbound frame not passed\n");
1054 kfree_skb(skb);
1055 return;
1056 }
1057 /* if this packet passes the active filter, record the time */
1058 if (!(ppp->active_filter
1059 && sk_run_filter(skb, ppp->active_filter,
1060 ppp->active_len) == 0))
1061 ppp->last_xmit = jiffies;
1062 skb_pull(skb, 2);
1063#else
1064 /* for data packets, record the time */
1065 ppp->last_xmit = jiffies;
1066#endif /* CONFIG_PPP_FILTER */
1067 }
1068
1069 ++ppp->stats.tx_packets;
1070 ppp->stats.tx_bytes += skb->len - 2;
1071
1072 switch (proto) {
1073 case PPP_IP:
1074 if (ppp->vj == 0 || (ppp->flags & SC_COMP_TCP) == 0)
1075 break;
1076 /* try to do VJ TCP header compression */
1077 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1078 GFP_ATOMIC);
1079 if (new_skb == 0) {
1080 printk(KERN_ERR "PPP: no memory (VJ comp pkt)\n");
1081 goto drop;
1082 }
1083 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1084 cp = skb->data + 2;
1085 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1086 new_skb->data + 2, &cp,
1087 !(ppp->flags & SC_NO_TCP_CCID));
1088 if (cp == skb->data + 2) {
1089 /* didn't compress */
1090 kfree_skb(new_skb);
1091 } else {
1092 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1093 proto = PPP_VJC_COMP;
1094 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1095 } else {
1096 proto = PPP_VJC_UNCOMP;
1097 cp[0] = skb->data[2];
1098 }
1099 kfree_skb(skb);
1100 skb = new_skb;
1101 cp = skb_put(skb, len + 2);
1102 cp[0] = 0;
1103 cp[1] = proto;
1104 }
1105 break;
1106
1107 case PPP_CCP:
1108 /* peek at outbound CCP frames */
1109 ppp_ccp_peek(ppp, skb, 0);
1110 break;
1111 }
1112
1113 /* try to do packet compression */
1114 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state != 0
1115 && proto != PPP_LCP && proto != PPP_CCP) {
1116 new_skb = alloc_skb(ppp->dev->mtu + ppp->dev->hard_header_len,
1117 GFP_ATOMIC);
1118 if (new_skb == 0) {
1119 printk(KERN_ERR "PPP: no memory (comp pkt)\n");
1120 goto drop;
1121 }
1122 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1123 skb_reserve(new_skb,
1124 ppp->dev->hard_header_len - PPP_HDRLEN);
1125
1126 /* compressor still expects A/C bytes in hdr */
1127 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1128 new_skb->data, skb->len + 2,
1129 ppp->dev->mtu + PPP_HDRLEN);
1130 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1131 kfree_skb(skb);
1132 skb = new_skb;
1133 skb_put(skb, len);
1134 skb_pull(skb, 2); /* pull off A/C bytes */
1135 } else {
1136 /* didn't compress, or CCP not up yet */
1137 kfree_skb(new_skb);
1138 }
1139 }
1140
1141 /*
1142 * If we are waiting for traffic (demand dialling),
1143 * queue it up for pppd to receive.
1144 */
1145 if (ppp->flags & SC_LOOP_TRAFFIC) {
1146 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1147 goto drop;
1148 skb_queue_tail(&ppp->file.rq, skb);
1149 wake_up_interruptible(&ppp->file.rwait);
1150 return;
1151 }
1152
1153 ppp->xmit_pending = skb;
1154 ppp_push(ppp);
1155 return;
1156
1157 drop:
1158 kfree_skb(skb);
1159 ++ppp->stats.tx_errors;
1160}
1161
1162/*
1163 * Try to send the frame in xmit_pending.
1164 * The caller should have the xmit path locked.
1165 */
1166static void
1167ppp_push(struct ppp *ppp)
1168{
1169 struct list_head *list;
1170 struct channel *pch;
1171 struct sk_buff *skb = ppp->xmit_pending;
1172
1173 if (skb == 0)
1174 return;
1175
1176 list = &ppp->channels;
1177 if (list_empty(list)) {
1178 /* nowhere to send the packet, just drop it */
1179 ppp->xmit_pending = NULL;
1180 kfree_skb(skb);
1181 return;
1182 }
1183
1184 if ((ppp->flags & SC_MULTILINK) == 0) {
1185 /* not doing multilink: send it down the first channel */
1186 list = list->next;
1187 pch = list_entry(list, struct channel, clist);
1188
1189 spin_lock_bh(&pch->downl);
1190 if (pch->chan) {
1191 if (pch->chan->ops->start_xmit(pch->chan, skb))
1192 ppp->xmit_pending = NULL;
1193 } else {
1194 /* channel got unregistered */
1195 kfree_skb(skb);
1196 ppp->xmit_pending = NULL;
1197 }
1198 spin_unlock_bh(&pch->downl);
1199 return;
1200 }
1201
1202#ifdef CONFIG_PPP_MULTILINK
1203 /* Multilink: fragment the packet over as many links
1204 as can take the packet at the moment. */
1205 if (!ppp_mp_explode(ppp, skb))
1206 return;
1207#endif /* CONFIG_PPP_MULTILINK */
1208
1209 ppp->xmit_pending = NULL;
1210 kfree_skb(skb);
1211}
1212
1213#ifdef CONFIG_PPP_MULTILINK
1214/*
1215 * Divide a packet to be transmitted into fragments and
1216 * send them out the individual links.
1217 */
1218static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1219{
1220 int nch, len, fragsize;
1221 int i, bits, hdrlen, mtu;
1222 int flen, fnb;
1223 unsigned char *p, *q;
1224 struct list_head *list;
1225 struct channel *pch;
1226 struct sk_buff *frag;
1227 struct ppp_channel *chan;
1228
1229 nch = 0;
1230 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1231 list = &ppp->channels;
1232 while ((list = list->next) != &ppp->channels) {
1233 pch = list_entry(list, struct channel, clist);
1234 nch += pch->avail = (skb_queue_len(&pch->file.xq) == 0);
1235 /*
1236 * If a channel hasn't had a fragment yet, it has to get
1237 * one before we send any fragments on later channels.
1238 * If it can't take a fragment now, don't give any
1239 * to subsequent channels.
1240 */
1241 if (!pch->had_frag && !pch->avail) {
1242 while ((list = list->next) != &ppp->channels) {
1243 pch = list_entry(list, struct channel, clist);
1244 pch->avail = 0;
1245 }
1246 break;
1247 }
1248 }
1249 if (nch == 0)
1250 return 0; /* can't take now, leave it in xmit_pending */
1251
1252 /* Do protocol field compression (XXX this should be optional) */
1253 p = skb->data;
1254 len = skb->len;
1255 if (*p == 0) {
1256 ++p;
1257 --len;
1258 }
1259
1260 /* decide on fragment size */
1261 fragsize = len;
1262 if (nch > 1) {
1263 int maxch = ROUNDUP(len, MIN_FRAG_SIZE);
1264 if (nch > maxch)
1265 nch = maxch;
1266 fragsize = ROUNDUP(fragsize, nch);
1267 }
1268
1269 /* skip to the channel after the one we last used
1270 and start at that one */
1271 for (i = 0; i < ppp->nxchan; ++i) {
1272 list = list->next;
1273 if (list == &ppp->channels) {
1274 i = 0;
1275 break;
1276 }
1277 }
1278
1279 /* create a fragment for each channel */
1280 bits = B;
1281 do {
1282 list = list->next;
1283 if (list == &ppp->channels) {
1284 i = 0;
1285 continue;
1286 }
1287 pch = list_entry(list, struct channel, clist);
1288 ++i;
1289 if (!pch->avail)
1290 continue;
1291
1292 /* check the channel's mtu and whether it is still attached. */
1293 spin_lock_bh(&pch->downl);
1294 if (pch->chan == 0 || (mtu = pch->chan->mtu) < hdrlen) {
1295 /* can't use this channel */
1296 spin_unlock_bh(&pch->downl);
1297 pch->avail = 0;
1298 if (--nch == 0)
1299 break;
1300 continue;
1301 }
1302
1303 /*
1304 * We have to create multiple fragments for this channel
1305 * if fragsize is greater than the channel's mtu.
1306 */
1307 if (fragsize > len)
1308 fragsize = len;
1309 for (flen = fragsize; flen > 0; flen -= fnb) {
1310 fnb = flen;
1311 if (fnb > mtu + 2 - hdrlen)
1312 fnb = mtu + 2 - hdrlen;
1313 if (fnb >= len)
1314 bits |= E;
1315 frag = alloc_skb(fnb + hdrlen, GFP_ATOMIC);
1316 if (frag == 0)
1317 goto noskb;
1318 q = skb_put(frag, fnb + hdrlen);
1319 /* make the MP header */
1320 q[0] = PPP_MP >> 8;
1321 q[1] = PPP_MP;
1322 if (ppp->flags & SC_MP_XSHORTSEQ) {
1323 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1324 q[3] = ppp->nxseq;
1325 } else {
1326 q[2] = bits;
1327 q[3] = ppp->nxseq >> 16;
1328 q[4] = ppp->nxseq >> 8;
1329 q[5] = ppp->nxseq;
1330 }
1331
1332 /* copy the data in */
1333 memcpy(q + hdrlen, p, fnb);
1334
1335 /* try to send it down the channel */
1336 chan = pch->chan;
1337 if (!chan->ops->start_xmit(chan, frag))
1338 skb_queue_tail(&pch->file.xq, frag);
1339 pch->had_frag = 1;
1340 p += fnb;
1341 len -= fnb;
1342 ++ppp->nxseq;
1343 bits = 0;
1344 }
1345 spin_unlock_bh(&pch->downl);
1346 } while (len > 0);
1347 ppp->nxchan = i;
1348
1349 return 1;
1350
1351 noskb:
1352 spin_unlock_bh(&pch->downl);
1353 if (ppp->debug & 1)
1354 printk(KERN_ERR "PPP: no memory (fragment)\n");
1355 ++ppp->stats.tx_errors;
1356 ++ppp->nxseq;
1357 return 1; /* abandon the frame */
1358}
1359#endif /* CONFIG_PPP_MULTILINK */
1360
1361/*
1362 * Try to send data out on a channel.
1363 */
1364static void
1365ppp_channel_push(struct channel *pch)
1366{
1367 struct sk_buff *skb;
1368 struct ppp *ppp;
1369
1370 spin_lock_bh(&pch->downl);
1371 if (pch->chan != 0) {
1372 while (skb_queue_len(&pch->file.xq) > 0) {
1373 skb = skb_dequeue(&pch->file.xq);
1374 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1375 /* put the packet back and try again later */
1376 skb_queue_head(&pch->file.xq, skb);
1377 break;
1378 }
1379 }
1380 } else {
1381 /* channel got deregistered */
1382 skb_queue_purge(&pch->file.xq);
1383 }
1384 spin_unlock_bh(&pch->downl);
1385 /* see if there is anything from the attached unit to be sent */
1386 if (skb_queue_len(&pch->file.xq) == 0) {
1387 read_lock_bh(&pch->upl);
1388 ppp = pch->ppp;
1389 if (ppp != 0)
1390 ppp_xmit_process(ppp);
1391 read_unlock_bh(&pch->upl);
1392 }
1393}
1394
1395/*
1396 * Receive-side routines.
1397 */
1398
1399/* misuse a few fields of the skb for MP reconstruction */
1400#define sequence priority
1401#define BEbits cb[0]
1402
1403static inline void
1404ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1405{
1406 ppp_recv_lock(ppp);
1407 /* ppp->dev == 0 means interface is closing down */
1408 if (ppp->dev != 0)
1409 ppp_receive_frame(ppp, skb, pch);
1410 else
1411 kfree_skb(skb);
1412 ppp_recv_unlock(ppp);
1413}
1414
1415void
1416ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1417{
1418 struct channel *pch = chan->ppp;
1419 int proto;
1420
1421 if (pch == 0 || skb->len == 0) {
1422 kfree_skb(skb);
1423 return;
1424 }
1425
1426 proto = PPP_PROTO(skb);
1427 read_lock_bh(&pch->upl);
1428 if (pch->ppp == 0 || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1429 /* put it on the channel queue */
1430 skb_queue_tail(&pch->file.rq, skb);
1431 /* drop old frames if queue too long */
1432 while (pch->file.rq.qlen > PPP_MAX_RQLEN
1433 && (skb = skb_dequeue(&pch->file.rq)) != 0)
1434 kfree_skb(skb);
1435 wake_up_interruptible(&pch->file.rwait);
1436 } else {
1437 ppp_do_recv(pch->ppp, skb, pch);
1438 }
1439 read_unlock_bh(&pch->upl);
1440}
1441
1442/* Put a 0-length skb in the receive queue as an error indication */
1443void
1444ppp_input_error(struct ppp_channel *chan, int code)
1445{
1446 struct channel *pch = chan->ppp;
1447 struct sk_buff *skb;
1448
1449 if (pch == 0)
1450 return;
1451
1452 read_lock_bh(&pch->upl);
1453 if (pch->ppp != 0) {
1454 skb = alloc_skb(0, GFP_ATOMIC);
1455 if (skb != 0) {
1456 skb->len = 0; /* probably unnecessary */
1457 skb->cb[0] = code;
1458 ppp_do_recv(pch->ppp, skb, pch);
1459 }
1460 }
1461 read_unlock_bh(&pch->upl);
1462}
1463
1464/*
1465 * We come in here to process a received frame.
1466 * The receive side of the ppp unit is locked.
1467 */
1468static void
1469ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1470{
1471 if (skb->len >= 2) {
1472#ifdef CONFIG_PPP_MULTILINK
1473 /* XXX do channel-level decompression here */
1474 if (PPP_PROTO(skb) == PPP_MP)
1475 ppp_receive_mp_frame(ppp, skb, pch);
1476 else
1477#endif /* CONFIG_PPP_MULTILINK */
1478 ppp_receive_nonmp_frame(ppp, skb);
1479 return;
1480 }
1481
1482 if (skb->len > 0)
1483 /* note: a 0-length skb is used as an error indication */
1484 ++ppp->stats.rx_length_errors;
1485
1486 kfree_skb(skb);
1487 ppp_receive_error(ppp);
1488}
1489
1490static void
1491ppp_receive_error(struct ppp *ppp)
1492{
1493 ++ppp->stats.rx_errors;
1494 if (ppp->vj != 0)
1495 slhc_toss(ppp->vj);
1496}
1497
1498static void
1499ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1500{
1501 struct sk_buff *ns;
1502 int proto, len, npi;
1503
1504 /*
1505 * Decompress the frame, if compressed.
1506 * Note that some decompressors need to see uncompressed frames
1507 * that come in as well as compressed frames.
1508 */
1509 if (ppp->rc_state != 0 && (ppp->rstate & SC_DECOMP_RUN)
1510 && (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1511 skb = ppp_decompress_frame(ppp, skb);
1512
1513 proto = PPP_PROTO(skb);
1514 switch (proto) {
1515 case PPP_VJC_COMP:
1516 /* decompress VJ compressed packets */
1517 if (ppp->vj == 0 || (ppp->flags & SC_REJ_COMP_TCP))
1518 goto err;
1519
1520 if (skb_tailroom(skb) < 124) {
1521 /* copy to a new sk_buff with more tailroom */
1522 ns = dev_alloc_skb(skb->len + 128);
1523 if (ns == 0) {
1524 printk(KERN_ERR"PPP: no memory (VJ decomp)\n");
1525 goto err;
1526 }
1527 skb_reserve(ns, 2);
1528 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1529 kfree_skb(skb);
1530 skb = ns;
1531 }
1532 else if (!pskb_may_pull(skb, skb->len))
1533 goto err;
1534
1535 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1536 if (len <= 0) {
1537 printk(KERN_DEBUG "PPP: VJ decompression error\n");
1538 goto err;
1539 }
1540 len += 2;
1541 if (len > skb->len)
1542 skb_put(skb, len - skb->len);
1543 else if (len < skb->len)
1544 skb_trim(skb, len);
1545 proto = PPP_IP;
1546 break;
1547
1548 case PPP_VJC_UNCOMP:
1549 if (ppp->vj == 0 || (ppp->flags & SC_REJ_COMP_TCP))
1550 goto err;
1551
1552 /* Until we fix the decompressor need to make sure
1553 * data portion is linear.
1554 */
1555 if (!pskb_may_pull(skb, skb->len))
1556 goto err;
1557
1558 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1559 printk(KERN_ERR "PPP: VJ uncompressed error\n");
1560 goto err;
1561 }
1562 proto = PPP_IP;
1563 break;
1564
1565 case PPP_CCP:
1566 ppp_ccp_peek(ppp, skb, 1);
1567 break;
1568 }
1569
1570 ++ppp->stats.rx_packets;
1571 ppp->stats.rx_bytes += skb->len - 2;
1572
1573 npi = proto_to_npindex(proto);
1574 if (npi < 0) {
1575 /* control or unknown frame - pass it to pppd */
1576 skb_queue_tail(&ppp->file.rq, skb);
1577 /* limit queue length by dropping old frames */
1578 while (ppp->file.rq.qlen > PPP_MAX_RQLEN
1579 && (skb = skb_dequeue(&ppp->file.rq)) != 0)
1580 kfree_skb(skb);
1581 /* wake up any process polling or blocking on read */
1582 wake_up_interruptible(&ppp->file.rwait);
1583
1584 } else {
1585 /* network protocol frame - give it to the kernel */
1586
1587#ifdef CONFIG_PPP_FILTER
1588 /* check if the packet passes the pass and active filters */
1589 /* the filter instructions are constructed assuming
1590 a four-byte PPP header on each packet */
1591 *skb_push(skb, 2) = 0;
1592 if (ppp->pass_filter
1593 && sk_run_filter(skb, ppp->pass_filter,
1594 ppp->pass_len) == 0) {
1595 if (ppp->debug & 1)
1596 printk(KERN_DEBUG "PPP: inbound frame not passed\n");
1597 kfree_skb(skb);
1598 return;
1599 }
1600 if (!(ppp->active_filter
1601 && sk_run_filter(skb, ppp->active_filter,
1602 ppp->active_len) == 0))
1603 ppp->last_recv = jiffies;
1604 skb_pull(skb, 2);
1605#else
1606 ppp->last_recv = jiffies;
1607#endif /* CONFIG_PPP_FILTER */
1608
1609 if ((ppp->dev->flags & IFF_UP) == 0
1610 || ppp->npmode[npi] != NPMODE_PASS) {
1611 kfree_skb(skb);
1612 } else {
1613 skb_pull(skb, 2); /* chop off protocol */
1614 skb->dev = ppp->dev;
1615 skb->protocol = htons(npindex_to_ethertype[npi]);
1616 skb->mac.raw = skb->data;
1617 skb->input_dev = ppp->dev;
1618 netif_rx(skb);
1619 ppp->dev->last_rx = jiffies;
1620 }
1621 }
1622 return;
1623
1624 err:
1625 kfree_skb(skb);
1626 ppp_receive_error(ppp);
1627}
1628
1629static struct sk_buff *
1630ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1631{
1632 int proto = PPP_PROTO(skb);
1633 struct sk_buff *ns;
1634 int len;
1635
1636 /* Until we fix all the decompressor's need to make sure
1637 * data portion is linear.
1638 */
1639 if (!pskb_may_pull(skb, skb->len))
1640 goto err;
1641
1642 if (proto == PPP_COMP) {
1643 ns = dev_alloc_skb(ppp->mru + PPP_HDRLEN);
1644 if (ns == 0) {
1645 printk(KERN_ERR "ppp_decompress_frame: no memory\n");
1646 goto err;
1647 }
1648 /* the decompressor still expects the A/C bytes in the hdr */
1649 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1650 skb->len + 2, ns->data, ppp->mru + PPP_HDRLEN);
1651 if (len < 0) {
1652 /* Pass the compressed frame to pppd as an
1653 error indication. */
1654 if (len == DECOMP_FATALERROR)
1655 ppp->rstate |= SC_DC_FERROR;
1656 kfree_skb(ns);
1657 goto err;
1658 }
1659
1660 kfree_skb(skb);
1661 skb = ns;
1662 skb_put(skb, len);
1663 skb_pull(skb, 2); /* pull off the A/C bytes */
1664
1665 } else {
1666 /* Uncompressed frame - pass to decompressor so it
1667 can update its dictionary if necessary. */
1668 if (ppp->rcomp->incomp)
1669 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1670 skb->len + 2);
1671 }
1672
1673 return skb;
1674
1675 err:
1676 ppp->rstate |= SC_DC_ERROR;
1677 ppp_receive_error(ppp);
1678 return skb;
1679}
1680
1681#ifdef CONFIG_PPP_MULTILINK
1682/*
1683 * Receive a multilink frame.
1684 * We put it on the reconstruction queue and then pull off
1685 * as many completed frames as we can.
1686 */
1687static void
1688ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1689{
1690 u32 mask, seq;
1691 struct list_head *l;
1692 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1693
1694 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
1695 goto err; /* no good, throw it away */
1696
1697 /* Decode sequence number and begin/end bits */
1698 if (ppp->flags & SC_MP_SHORTSEQ) {
1699 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1700 mask = 0xfff;
1701 } else {
1702 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1703 mask = 0xffffff;
1704 }
1705 skb->BEbits = skb->data[2];
1706 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
1707
1708 /*
1709 * Do protocol ID decompression on the first fragment of each packet.
1710 */
1711 if ((skb->BEbits & B) && (skb->data[0] & 1))
1712 *skb_push(skb, 1) = 0;
1713
1714 /*
1715 * Expand sequence number to 32 bits, making it as close
1716 * as possible to ppp->minseq.
1717 */
1718 seq |= ppp->minseq & ~mask;
1719 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
1720 seq += mask + 1;
1721 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
1722 seq -= mask + 1; /* should never happen */
1723 skb->sequence = seq;
1724 pch->lastseq = seq;
1725
1726 /*
1727 * If this packet comes before the next one we were expecting,
1728 * drop it.
1729 */
1730 if (seq_before(seq, ppp->nextseq)) {
1731 kfree_skb(skb);
1732 ++ppp->stats.rx_dropped;
1733 ppp_receive_error(ppp);
1734 return;
1735 }
1736
1737 /*
1738 * Reevaluate minseq, the minimum over all channels of the
1739 * last sequence number received on each channel. Because of
1740 * the increasing sequence number rule, we know that any fragment
1741 * before `minseq' which hasn't arrived is never going to arrive.
1742 * The list of channels can't change because we have the receive
1743 * side of the ppp unit locked.
1744 */
1745 for (l = ppp->channels.next; l != &ppp->channels; l = l->next) {
1746 struct channel *ch = list_entry(l, struct channel, clist);
1747 if (seq_before(ch->lastseq, seq))
1748 seq = ch->lastseq;
1749 }
1750 if (seq_before(ppp->minseq, seq))
1751 ppp->minseq = seq;
1752
1753 /* Put the fragment on the reconstruction queue */
1754 ppp_mp_insert(ppp, skb);
1755
1756 /* If the queue is getting long, don't wait any longer for packets
1757 before the start of the queue. */
1758 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN
1759 && seq_before(ppp->minseq, ppp->mrq.next->sequence))
1760 ppp->minseq = ppp->mrq.next->sequence;
1761
1762 /* Pull completed packets off the queue and receive them. */
1763 while ((skb = ppp_mp_reconstruct(ppp)) != 0)
1764 ppp_receive_nonmp_frame(ppp, skb);
1765
1766 return;
1767
1768 err:
1769 kfree_skb(skb);
1770 ppp_receive_error(ppp);
1771}
1772
1773/*
1774 * Insert a fragment on the MP reconstruction queue.
1775 * The queue is ordered by increasing sequence number.
1776 */
1777static void
1778ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
1779{
1780 struct sk_buff *p;
1781 struct sk_buff_head *list = &ppp->mrq;
1782 u32 seq = skb->sequence;
1783
1784 /* N.B. we don't need to lock the list lock because we have the
1785 ppp unit receive-side lock. */
1786 for (p = list->next; p != (struct sk_buff *)list; p = p->next)
1787 if (seq_before(seq, p->sequence))
1788 break;
1789 __skb_insert(skb, p->prev, p, list);
1790}
1791
1792/*
1793 * Reconstruct a packet from the MP fragment queue.
1794 * We go through increasing sequence numbers until we find a
1795 * complete packet, or we get to the sequence number for a fragment
1796 * which hasn't arrived but might still do so.
1797 */
1798struct sk_buff *
1799ppp_mp_reconstruct(struct ppp *ppp)
1800{
1801 u32 seq = ppp->nextseq;
1802 u32 minseq = ppp->minseq;
1803 struct sk_buff_head *list = &ppp->mrq;
1804 struct sk_buff *p, *next;
1805 struct sk_buff *head, *tail;
1806 struct sk_buff *skb = NULL;
1807 int lost = 0, len = 0;
1808
1809 if (ppp->mrru == 0) /* do nothing until mrru is set */
1810 return NULL;
1811 head = list->next;
1812 tail = NULL;
1813 for (p = head; p != (struct sk_buff *) list; p = next) {
1814 next = p->next;
1815 if (seq_before(p->sequence, seq)) {
1816 /* this can't happen, anyway ignore the skb */
1817 printk(KERN_ERR "ppp_mp_reconstruct bad seq %u < %u\n",
1818 p->sequence, seq);
1819 head = next;
1820 continue;
1821 }
1822 if (p->sequence != seq) {
1823 /* Fragment `seq' is missing. If it is after
1824 minseq, it might arrive later, so stop here. */
1825 if (seq_after(seq, minseq))
1826 break;
1827 /* Fragment `seq' is lost, keep going. */
1828 lost = 1;
1829 seq = seq_before(minseq, p->sequence)?
1830 minseq + 1: p->sequence;
1831 next = p;
1832 continue;
1833 }
1834
1835 /*
1836 * At this point we know that all the fragments from
1837 * ppp->nextseq to seq are either present or lost.
1838 * Also, there are no complete packets in the queue
1839 * that have no missing fragments and end before this
1840 * fragment.
1841 */
1842
1843 /* B bit set indicates this fragment starts a packet */
1844 if (p->BEbits & B) {
1845 head = p;
1846 lost = 0;
1847 len = 0;
1848 }
1849
1850 len += p->len;
1851
1852 /* Got a complete packet yet? */
1853 if (lost == 0 && (p->BEbits & E) && (head->BEbits & B)) {
1854 if (len > ppp->mrru + 2) {
1855 ++ppp->stats.rx_length_errors;
1856 printk(KERN_DEBUG "PPP: reconstructed packet"
1857 " is too long (%d)\n", len);
1858 } else if (p == head) {
1859 /* fragment is complete packet - reuse skb */
1860 tail = p;
1861 skb = skb_get(p);
1862 break;
1863 } else if ((skb = dev_alloc_skb(len)) == NULL) {
1864 ++ppp->stats.rx_missed_errors;
1865 printk(KERN_DEBUG "PPP: no memory for "
1866 "reconstructed packet");
1867 } else {
1868 tail = p;
1869 break;
1870 }
1871 ppp->nextseq = seq + 1;
1872 }
1873
1874 /*
1875 * If this is the ending fragment of a packet,
1876 * and we haven't found a complete valid packet yet,
1877 * we can discard up to and including this fragment.
1878 */
1879 if (p->BEbits & E)
1880 head = next;
1881
1882 ++seq;
1883 }
1884
1885 /* If we have a complete packet, copy it all into one skb. */
1886 if (tail != NULL) {
1887 /* If we have discarded any fragments,
1888 signal a receive error. */
1889 if (head->sequence != ppp->nextseq) {
1890 if (ppp->debug & 1)
1891 printk(KERN_DEBUG " missed pkts %u..%u\n",
1892 ppp->nextseq, head->sequence-1);
1893 ++ppp->stats.rx_dropped;
1894 ppp_receive_error(ppp);
1895 }
1896
1897 if (head != tail)
1898 /* copy to a single skb */
1899 for (p = head; p != tail->next; p = p->next)
1900 skb_copy_bits(p, 0, skb_put(skb, p->len), p->len);
1901 ppp->nextseq = tail->sequence + 1;
1902 head = tail->next;
1903 }
1904
1905 /* Discard all the skbuffs that we have copied the data out of
1906 or that we can't use. */
1907 while ((p = list->next) != head) {
1908 __skb_unlink(p, list);
1909 kfree_skb(p);
1910 }
1911
1912 return skb;
1913}
1914#endif /* CONFIG_PPP_MULTILINK */
1915
1916/*
1917 * Channel interface.
1918 */
1919
1920/*
1921 * Create a new, unattached ppp channel.
1922 */
1923int
1924ppp_register_channel(struct ppp_channel *chan)
1925{
1926 struct channel *pch;
1927
1928 pch = kmalloc(sizeof(struct channel), GFP_KERNEL);
1929 if (pch == 0)
1930 return -ENOMEM;
1931 memset(pch, 0, sizeof(struct channel));
1932 pch->ppp = NULL;
1933 pch->chan = chan;
1934 chan->ppp = pch;
1935 init_ppp_file(&pch->file, CHANNEL);
1936 pch->file.hdrlen = chan->hdrlen;
1937#ifdef CONFIG_PPP_MULTILINK
1938 pch->lastseq = -1;
1939#endif /* CONFIG_PPP_MULTILINK */
1940 init_rwsem(&pch->chan_sem);
1941 spin_lock_init(&pch->downl);
1942 rwlock_init(&pch->upl);
1943 spin_lock_bh(&all_channels_lock);
1944 pch->file.index = ++last_channel_index;
1945 list_add(&pch->list, &new_channels);
1946 atomic_inc(&channel_count);
1947 spin_unlock_bh(&all_channels_lock);
1948 return 0;
1949}
1950
1951/*
1952 * Return the index of a channel.
1953 */
1954int ppp_channel_index(struct ppp_channel *chan)
1955{
1956 struct channel *pch = chan->ppp;
1957
1958 if (pch != 0)
1959 return pch->file.index;
1960 return -1;
1961}
1962
1963/*
1964 * Return the PPP unit number to which a channel is connected.
1965 */
1966int ppp_unit_number(struct ppp_channel *chan)
1967{
1968 struct channel *pch = chan->ppp;
1969 int unit = -1;
1970
1971 if (pch != 0) {
1972 read_lock_bh(&pch->upl);
1973 if (pch->ppp != 0)
1974 unit = pch->ppp->file.index;
1975 read_unlock_bh(&pch->upl);
1976 }
1977 return unit;
1978}
1979
1980/*
1981 * Disconnect a channel from the generic layer.
1982 * This must be called in process context.
1983 */
1984void
1985ppp_unregister_channel(struct ppp_channel *chan)
1986{
1987 struct channel *pch = chan->ppp;
1988
1989 if (pch == 0)
1990 return; /* should never happen */
1991 chan->ppp = NULL;
1992
1993 /*
1994 * This ensures that we have returned from any calls into the
1995 * the channel's start_xmit or ioctl routine before we proceed.
1996 */
1997 down_write(&pch->chan_sem);
1998 spin_lock_bh(&pch->downl);
1999 pch->chan = NULL;
2000 spin_unlock_bh(&pch->downl);
2001 up_write(&pch->chan_sem);
2002 ppp_disconnect_channel(pch);
2003 spin_lock_bh(&all_channels_lock);
2004 list_del(&pch->list);
2005 spin_unlock_bh(&all_channels_lock);
2006 pch->file.dead = 1;
2007 wake_up_interruptible(&pch->file.rwait);
2008 if (atomic_dec_and_test(&pch->file.refcnt))
2009 ppp_destroy_channel(pch);
2010}
2011
2012/*
2013 * Callback from a channel when it can accept more to transmit.
2014 * This should be called at BH/softirq level, not interrupt level.
2015 */
2016void
2017ppp_output_wakeup(struct ppp_channel *chan)
2018{
2019 struct channel *pch = chan->ppp;
2020
2021 if (pch == 0)
2022 return;
2023 ppp_channel_push(pch);
2024}
2025
2026/*
2027 * Compression control.
2028 */
2029
2030/* Process the PPPIOCSCOMPRESS ioctl. */
2031static int
2032ppp_set_compress(struct ppp *ppp, unsigned long arg)
2033{
2034 int err;
2035 struct compressor *cp, *ocomp;
2036 struct ppp_option_data data;
2037 void *state, *ostate;
2038 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2039
2040 err = -EFAULT;
2041 if (copy_from_user(&data, (void __user *) arg, sizeof(data))
2042 || (data.length <= CCP_MAX_OPTION_LENGTH
2043 && copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2044 goto out;
2045 err = -EINVAL;
2046 if (data.length > CCP_MAX_OPTION_LENGTH
2047 || ccp_option[1] < 2 || ccp_option[1] > data.length)
2048 goto out;
2049
2050 cp = find_compressor(ccp_option[0]);
2051#ifdef CONFIG_KMOD
2052 if (cp == 0) {
2053 request_module("ppp-compress-%d", ccp_option[0]);
2054 cp = find_compressor(ccp_option[0]);
2055 }
2056#endif /* CONFIG_KMOD */
2057 if (cp == 0)
2058 goto out;
2059
2060 err = -ENOBUFS;
2061 if (data.transmit) {
2062 state = cp->comp_alloc(ccp_option, data.length);
2063 if (state != 0) {
2064 ppp_xmit_lock(ppp);
2065 ppp->xstate &= ~SC_COMP_RUN;
2066 ocomp = ppp->xcomp;
2067 ostate = ppp->xc_state;
2068 ppp->xcomp = cp;
2069 ppp->xc_state = state;
2070 ppp_xmit_unlock(ppp);
2071 if (ostate != 0) {
2072 ocomp->comp_free(ostate);
2073 module_put(ocomp->owner);
2074 }
2075 err = 0;
2076 } else
2077 module_put(cp->owner);
2078
2079 } else {
2080 state = cp->decomp_alloc(ccp_option, data.length);
2081 if (state != 0) {
2082 ppp_recv_lock(ppp);
2083 ppp->rstate &= ~SC_DECOMP_RUN;
2084 ocomp = ppp->rcomp;
2085 ostate = ppp->rc_state;
2086 ppp->rcomp = cp;
2087 ppp->rc_state = state;
2088 ppp_recv_unlock(ppp);
2089 if (ostate != 0) {
2090 ocomp->decomp_free(ostate);
2091 module_put(ocomp->owner);
2092 }
2093 err = 0;
2094 } else
2095 module_put(cp->owner);
2096 }
2097
2098 out:
2099 return err;
2100}
2101
2102/*
2103 * Look at a CCP packet and update our state accordingly.
2104 * We assume the caller has the xmit or recv path locked.
2105 */
2106static void
2107ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2108{
2109 unsigned char *dp;
2110 int len;
2111
2112 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2113 return; /* no header */
2114 dp = skb->data + 2;
2115
2116 switch (CCP_CODE(dp)) {
2117 case CCP_CONFREQ:
2118
2119 /* A ConfReq starts negotiation of compression
2120 * in one direction of transmission,
2121 * and hence brings it down...but which way?
2122 *
2123 * Remember:
2124 * A ConfReq indicates what the sender would like to receive
2125 */
2126 if(inbound)
2127 /* He is proposing what I should send */
2128 ppp->xstate &= ~SC_COMP_RUN;
2129 else
2130 /* I am proposing to what he should send */
2131 ppp->rstate &= ~SC_DECOMP_RUN;
2132
2133 break;
2134
2135 case CCP_TERMREQ:
2136 case CCP_TERMACK:
2137 /*
2138 * CCP is going down, both directions of transmission
2139 */
2140 ppp->rstate &= ~SC_DECOMP_RUN;
2141 ppp->xstate &= ~SC_COMP_RUN;
2142 break;
2143
2144 case CCP_CONFACK:
2145 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2146 break;
2147 len = CCP_LENGTH(dp);
2148 if (!pskb_may_pull(skb, len + 2))
2149 return; /* too short */
2150 dp += CCP_HDRLEN;
2151 len -= CCP_HDRLEN;
2152 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2153 break;
2154 if (inbound) {
2155 /* we will start receiving compressed packets */
2156 if (ppp->rc_state == 0)
2157 break;
2158 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2159 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2160 ppp->rstate |= SC_DECOMP_RUN;
2161 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2162 }
2163 } else {
2164 /* we will soon start sending compressed packets */
2165 if (ppp->xc_state == 0)
2166 break;
2167 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2168 ppp->file.index, 0, ppp->debug))
2169 ppp->xstate |= SC_COMP_RUN;
2170 }
2171 break;
2172
2173 case CCP_RESETACK:
2174 /* reset the [de]compressor */
2175 if ((ppp->flags & SC_CCP_UP) == 0)
2176 break;
2177 if (inbound) {
2178 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2179 ppp->rcomp->decomp_reset(ppp->rc_state);
2180 ppp->rstate &= ~SC_DC_ERROR;
2181 }
2182 } else {
2183 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2184 ppp->xcomp->comp_reset(ppp->xc_state);
2185 }
2186 break;
2187 }
2188}
2189
2190/* Free up compression resources. */
2191static void
2192ppp_ccp_closed(struct ppp *ppp)
2193{
2194 void *xstate, *rstate;
2195 struct compressor *xcomp, *rcomp;
2196
2197 ppp_lock(ppp);
2198 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2199 ppp->xstate = 0;
2200 xcomp = ppp->xcomp;
2201 xstate = ppp->xc_state;
2202 ppp->xc_state = NULL;
2203 ppp->rstate = 0;
2204 rcomp = ppp->rcomp;
2205 rstate = ppp->rc_state;
2206 ppp->rc_state = NULL;
2207 ppp_unlock(ppp);
2208
2209 if (xstate) {
2210 xcomp->comp_free(xstate);
2211 module_put(xcomp->owner);
2212 }
2213 if (rstate) {
2214 rcomp->decomp_free(rstate);
2215 module_put(rcomp->owner);
2216 }
2217}
2218
2219/* List of compressors. */
2220static LIST_HEAD(compressor_list);
2221static DEFINE_SPINLOCK(compressor_list_lock);
2222
2223struct compressor_entry {
2224 struct list_head list;
2225 struct compressor *comp;
2226};
2227
2228static struct compressor_entry *
2229find_comp_entry(int proto)
2230{
2231 struct compressor_entry *ce;
2232 struct list_head *list = &compressor_list;
2233
2234 while ((list = list->next) != &compressor_list) {
2235 ce = list_entry(list, struct compressor_entry, list);
2236 if (ce->comp->compress_proto == proto)
2237 return ce;
2238 }
2239 return NULL;
2240}
2241
2242/* Register a compressor */
2243int
2244ppp_register_compressor(struct compressor *cp)
2245{
2246 struct compressor_entry *ce;
2247 int ret;
2248 spin_lock(&compressor_list_lock);
2249 ret = -EEXIST;
2250 if (find_comp_entry(cp->compress_proto) != 0)
2251 goto out;
2252 ret = -ENOMEM;
2253 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2254 if (ce == 0)
2255 goto out;
2256 ret = 0;
2257 ce->comp = cp;
2258 list_add(&ce->list, &compressor_list);
2259 out:
2260 spin_unlock(&compressor_list_lock);
2261 return ret;
2262}
2263
2264/* Unregister a compressor */
2265void
2266ppp_unregister_compressor(struct compressor *cp)
2267{
2268 struct compressor_entry *ce;
2269
2270 spin_lock(&compressor_list_lock);
2271 ce = find_comp_entry(cp->compress_proto);
2272 if (ce != 0 && ce->comp == cp) {
2273 list_del(&ce->list);
2274 kfree(ce);
2275 }
2276 spin_unlock(&compressor_list_lock);
2277}
2278
2279/* Find a compressor. */
2280static struct compressor *
2281find_compressor(int type)
2282{
2283 struct compressor_entry *ce;
2284 struct compressor *cp = NULL;
2285
2286 spin_lock(&compressor_list_lock);
2287 ce = find_comp_entry(type);
2288 if (ce != 0) {
2289 cp = ce->comp;
2290 if (!try_module_get(cp->owner))
2291 cp = NULL;
2292 }
2293 spin_unlock(&compressor_list_lock);
2294 return cp;
2295}
2296
2297/*
2298 * Miscelleneous stuff.
2299 */
2300
2301static void
2302ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2303{
2304 struct slcompress *vj = ppp->vj;
2305
2306 memset(st, 0, sizeof(*st));
2307 st->p.ppp_ipackets = ppp->stats.rx_packets;
2308 st->p.ppp_ierrors = ppp->stats.rx_errors;
2309 st->p.ppp_ibytes = ppp->stats.rx_bytes;
2310 st->p.ppp_opackets = ppp->stats.tx_packets;
2311 st->p.ppp_oerrors = ppp->stats.tx_errors;
2312 st->p.ppp_obytes = ppp->stats.tx_bytes;
2313 if (vj == 0)
2314 return;
2315 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2316 st->vj.vjs_compressed = vj->sls_o_compressed;
2317 st->vj.vjs_searches = vj->sls_o_searches;
2318 st->vj.vjs_misses = vj->sls_o_misses;
2319 st->vj.vjs_errorin = vj->sls_i_error;
2320 st->vj.vjs_tossed = vj->sls_i_tossed;
2321 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2322 st->vj.vjs_compressedin = vj->sls_i_compressed;
2323}
2324
2325/*
2326 * Stuff for handling the lists of ppp units and channels
2327 * and for initialization.
2328 */
2329
2330/*
2331 * Create a new ppp interface unit. Fails if it can't allocate memory
2332 * or if there is already a unit with the requested number.
2333 * unit == -1 means allocate a new number.
2334 */
2335static struct ppp *
2336ppp_create_interface(int unit, int *retp)
2337{
2338 struct ppp *ppp;
2339 struct net_device *dev = NULL;
2340 int ret = -ENOMEM;
2341 int i;
2342
2343 ppp = kmalloc(sizeof(struct ppp), GFP_KERNEL);
2344 if (!ppp)
2345 goto out;
2346 dev = alloc_netdev(0, "", ppp_setup);
2347 if (!dev)
2348 goto out1;
2349 memset(ppp, 0, sizeof(struct ppp));
2350
2351 ppp->mru = PPP_MRU;
2352 init_ppp_file(&ppp->file, INTERFACE);
2353 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2354 for (i = 0; i < NUM_NP; ++i)
2355 ppp->npmode[i] = NPMODE_PASS;
2356 INIT_LIST_HEAD(&ppp->channels);
2357 spin_lock_init(&ppp->rlock);
2358 spin_lock_init(&ppp->wlock);
2359#ifdef CONFIG_PPP_MULTILINK
2360 ppp->minseq = -1;
2361 skb_queue_head_init(&ppp->mrq);
2362#endif /* CONFIG_PPP_MULTILINK */
2363 ppp->dev = dev;
2364 dev->priv = ppp;
2365
2366 dev->hard_start_xmit = ppp_start_xmit;
2367 dev->get_stats = ppp_net_stats;
2368 dev->do_ioctl = ppp_net_ioctl;
2369
2370 ret = -EEXIST;
2371 down(&all_ppp_sem);
2372 if (unit < 0)
2373 unit = cardmap_find_first_free(all_ppp_units);
2374 else if (cardmap_get(all_ppp_units, unit) != NULL)
2375 goto out2; /* unit already exists */
2376
2377 /* Initialize the new ppp unit */
2378 ppp->file.index = unit;
2379 sprintf(dev->name, "ppp%d", unit);
2380
2381 ret = register_netdev(dev);
2382 if (ret != 0) {
2383 printk(KERN_ERR "PPP: couldn't register device %s (%d)\n",
2384 dev->name, ret);
2385 goto out2;
2386 }
2387
2388 atomic_inc(&ppp_unit_count);
2389 cardmap_set(&all_ppp_units, unit, ppp);
2390 up(&all_ppp_sem);
2391 *retp = 0;
2392 return ppp;
2393
2394out2:
2395 up(&all_ppp_sem);
2396 free_netdev(dev);
2397out1:
2398 kfree(ppp);
2399out:
2400 *retp = ret;
2401 return NULL;
2402}
2403
2404/*
2405 * Initialize a ppp_file structure.
2406 */
2407static void
2408init_ppp_file(struct ppp_file *pf, int kind)
2409{
2410 pf->kind = kind;
2411 skb_queue_head_init(&pf->xq);
2412 skb_queue_head_init(&pf->rq);
2413 atomic_set(&pf->refcnt, 1);
2414 init_waitqueue_head(&pf->rwait);
2415}
2416
2417/*
2418 * Take down a ppp interface unit - called when the owning file
2419 * (the one that created the unit) is closed or detached.
2420 */
2421static void ppp_shutdown_interface(struct ppp *ppp)
2422{
2423 struct net_device *dev;
2424
2425 down(&all_ppp_sem);
2426 ppp_lock(ppp);
2427 dev = ppp->dev;
2428 ppp->dev = NULL;
2429 ppp_unlock(ppp);
2430 /* This will call dev_close() for us. */
2431 if (dev) {
2432 unregister_netdev(dev);
2433 free_netdev(dev);
2434 }
2435 cardmap_set(&all_ppp_units, ppp->file.index, NULL);
2436 ppp->file.dead = 1;
2437 ppp->owner = NULL;
2438 wake_up_interruptible(&ppp->file.rwait);
2439 up(&all_ppp_sem);
2440}
2441
2442/*
2443 * Free the memory used by a ppp unit. This is only called once
2444 * there are no channels connected to the unit and no file structs
2445 * that reference the unit.
2446 */
2447static void ppp_destroy_interface(struct ppp *ppp)
2448{
2449 atomic_dec(&ppp_unit_count);
2450
2451 if (!ppp->file.dead || ppp->n_channels) {
2452 /* "can't happen" */
2453 printk(KERN_ERR "ppp: destroying ppp struct %p but dead=%d "
2454 "n_channels=%d !\n", ppp, ppp->file.dead,
2455 ppp->n_channels);
2456 return;
2457 }
2458
2459 ppp_ccp_closed(ppp);
2460 if (ppp->vj) {
2461 slhc_free(ppp->vj);
2462 ppp->vj = NULL;
2463 }
2464 skb_queue_purge(&ppp->file.xq);
2465 skb_queue_purge(&ppp->file.rq);
2466#ifdef CONFIG_PPP_MULTILINK
2467 skb_queue_purge(&ppp->mrq);
2468#endif /* CONFIG_PPP_MULTILINK */
2469#ifdef CONFIG_PPP_FILTER
2470 if (ppp->pass_filter) {
2471 kfree(ppp->pass_filter);
2472 ppp->pass_filter = NULL;
2473 }
2474 if (ppp->active_filter) {
2475 kfree(ppp->active_filter);
2476 ppp->active_filter = NULL;
2477 }
2478#endif /* CONFIG_PPP_FILTER */
2479
2480 kfree(ppp);
2481}
2482
2483/*
2484 * Locate an existing ppp unit.
2485 * The caller should have locked the all_ppp_sem.
2486 */
2487static struct ppp *
2488ppp_find_unit(int unit)
2489{
2490 return cardmap_get(all_ppp_units, unit);
2491}
2492
2493/*
2494 * Locate an existing ppp channel.
2495 * The caller should have locked the all_channels_lock.
2496 * First we look in the new_channels list, then in the
2497 * all_channels list. If found in the new_channels list,
2498 * we move it to the all_channels list. This is for speed
2499 * when we have a lot of channels in use.
2500 */
2501static struct channel *
2502ppp_find_channel(int unit)
2503{
2504 struct channel *pch;
2505 struct list_head *list;
2506
2507 list = &new_channels;
2508 while ((list = list->next) != &new_channels) {
2509 pch = list_entry(list, struct channel, list);
2510 if (pch->file.index == unit) {
2511 list_del(&pch->list);
2512 list_add(&pch->list, &all_channels);
2513 return pch;
2514 }
2515 }
2516 list = &all_channels;
2517 while ((list = list->next) != &all_channels) {
2518 pch = list_entry(list, struct channel, list);
2519 if (pch->file.index == unit)
2520 return pch;
2521 }
2522 return NULL;
2523}
2524
2525/*
2526 * Connect a PPP channel to a PPP interface unit.
2527 */
2528static int
2529ppp_connect_channel(struct channel *pch, int unit)
2530{
2531 struct ppp *ppp;
2532 int ret = -ENXIO;
2533 int hdrlen;
2534
2535 down(&all_ppp_sem);
2536 ppp = ppp_find_unit(unit);
2537 if (ppp == 0)
2538 goto out;
2539 write_lock_bh(&pch->upl);
2540 ret = -EINVAL;
2541 if (pch->ppp != 0)
2542 goto outl;
2543
2544 ppp_lock(ppp);
2545 if (pch->file.hdrlen > ppp->file.hdrlen)
2546 ppp->file.hdrlen = pch->file.hdrlen;
2547 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2548 if (ppp->dev && hdrlen > ppp->dev->hard_header_len)
2549 ppp->dev->hard_header_len = hdrlen;
2550 list_add_tail(&pch->clist, &ppp->channels);
2551 ++ppp->n_channels;
2552 pch->ppp = ppp;
2553 atomic_inc(&ppp->file.refcnt);
2554 ppp_unlock(ppp);
2555 ret = 0;
2556
2557 outl:
2558 write_unlock_bh(&pch->upl);
2559 out:
2560 up(&all_ppp_sem);
2561 return ret;
2562}
2563
2564/*
2565 * Disconnect a channel from its ppp unit.
2566 */
2567static int
2568ppp_disconnect_channel(struct channel *pch)
2569{
2570 struct ppp *ppp;
2571 int err = -EINVAL;
2572
2573 write_lock_bh(&pch->upl);
2574 ppp = pch->ppp;
2575 pch->ppp = NULL;
2576 write_unlock_bh(&pch->upl);
2577 if (ppp != 0) {
2578 /* remove it from the ppp unit's list */
2579 ppp_lock(ppp);
2580 list_del(&pch->clist);
2581 if (--ppp->n_channels == 0)
2582 wake_up_interruptible(&ppp->file.rwait);
2583 ppp_unlock(ppp);
2584 if (atomic_dec_and_test(&ppp->file.refcnt))
2585 ppp_destroy_interface(ppp);
2586 err = 0;
2587 }
2588 return err;
2589}
2590
2591/*
2592 * Free up the resources used by a ppp channel.
2593 */
2594static void ppp_destroy_channel(struct channel *pch)
2595{
2596 atomic_dec(&channel_count);
2597
2598 if (!pch->file.dead) {
2599 /* "can't happen" */
2600 printk(KERN_ERR "ppp: destroying undead channel %p !\n",
2601 pch);
2602 return;
2603 }
2604 skb_queue_purge(&pch->file.xq);
2605 skb_queue_purge(&pch->file.rq);
2606 kfree(pch);
2607}
2608
2609static void __exit ppp_cleanup(void)
2610{
2611 /* should never happen */
2612 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2613 printk(KERN_ERR "PPP: removing module but units remain!\n");
2614 cardmap_destroy(&all_ppp_units);
2615 if (unregister_chrdev(PPP_MAJOR, "ppp") != 0)
2616 printk(KERN_ERR "PPP: failed to unregister PPP device\n");
2617 devfs_remove("ppp");
2618 class_simple_device_remove(MKDEV(PPP_MAJOR, 0));
2619 class_simple_destroy(ppp_class);
2620}
2621
2622/*
2623 * Cardmap implementation.
2624 */
2625static void *cardmap_get(struct cardmap *map, unsigned int nr)
2626{
2627 struct cardmap *p;
2628 int i;
2629
2630 for (p = map; p != NULL; ) {
2631 if ((i = nr >> p->shift) >= CARDMAP_WIDTH)
2632 return NULL;
2633 if (p->shift == 0)
2634 return p->ptr[i];
2635 nr &= ~(CARDMAP_MASK << p->shift);
2636 p = p->ptr[i];
2637 }
2638 return NULL;
2639}
2640
2641static void cardmap_set(struct cardmap **pmap, unsigned int nr, void *ptr)
2642{
2643 struct cardmap *p;
2644 int i;
2645
2646 p = *pmap;
2647 if (p == NULL || (nr >> p->shift) >= CARDMAP_WIDTH) {
2648 do {
2649 /* need a new top level */
2650 struct cardmap *np = kmalloc(sizeof(*np), GFP_KERNEL);
2651 memset(np, 0, sizeof(*np));
2652 np->ptr[0] = p;
2653 if (p != NULL) {
2654 np->shift = p->shift + CARDMAP_ORDER;
2655 p->parent = np;
2656 } else
2657 np->shift = 0;
2658 p = np;
2659 } while ((nr >> p->shift) >= CARDMAP_WIDTH);
2660 *pmap = p;
2661 }
2662 while (p->shift > 0) {
2663 i = (nr >> p->shift) & CARDMAP_MASK;
2664 if (p->ptr[i] == NULL) {
2665 struct cardmap *np = kmalloc(sizeof(*np), GFP_KERNEL);
2666 memset(np, 0, sizeof(*np));
2667 np->shift = p->shift - CARDMAP_ORDER;
2668 np->parent = p;
2669 p->ptr[i] = np;
2670 }
2671 if (ptr == NULL)
2672 clear_bit(i, &p->inuse);
2673 p = p->ptr[i];
2674 }
2675 i = nr & CARDMAP_MASK;
2676 p->ptr[i] = ptr;
2677 if (ptr != NULL)
2678 set_bit(i, &p->inuse);
2679 else
2680 clear_bit(i, &p->inuse);
2681}
2682
2683static unsigned int cardmap_find_first_free(struct cardmap *map)
2684{
2685 struct cardmap *p;
2686 unsigned int nr = 0;
2687 int i;
2688
2689 if ((p = map) == NULL)
2690 return 0;
2691 for (;;) {
2692 i = find_first_zero_bit(&p->inuse, CARDMAP_WIDTH);
2693 if (i >= CARDMAP_WIDTH) {
2694 if (p->parent == NULL)
2695 return CARDMAP_WIDTH << p->shift;
2696 p = p->parent;
2697 i = (nr >> p->shift) & CARDMAP_MASK;
2698 set_bit(i, &p->inuse);
2699 continue;
2700 }
2701 nr = (nr & (~CARDMAP_MASK << p->shift)) | (i << p->shift);
2702 if (p->shift == 0 || p->ptr[i] == NULL)
2703 return nr;
2704 p = p->ptr[i];
2705 }
2706}
2707
2708static void cardmap_destroy(struct cardmap **pmap)
2709{
2710 struct cardmap *p, *np;
2711 int i;
2712
2713 for (p = *pmap; p != NULL; p = np) {
2714 if (p->shift != 0) {
2715 for (i = 0; i < CARDMAP_WIDTH; ++i)
2716 if (p->ptr[i] != NULL)
2717 break;
2718 if (i < CARDMAP_WIDTH) {
2719 np = p->ptr[i];
2720 p->ptr[i] = NULL;
2721 continue;
2722 }
2723 }
2724 np = p->parent;
2725 kfree(p);
2726 }
2727 *pmap = NULL;
2728}
2729
2730/* Module/initialization stuff */
2731
2732module_init(ppp_init);
2733module_exit(ppp_cleanup);
2734
2735EXPORT_SYMBOL(ppp_register_channel);
2736EXPORT_SYMBOL(ppp_unregister_channel);
2737EXPORT_SYMBOL(ppp_channel_index);
2738EXPORT_SYMBOL(ppp_unit_number);
2739EXPORT_SYMBOL(ppp_input);
2740EXPORT_SYMBOL(ppp_input_error);
2741EXPORT_SYMBOL(ppp_output_wakeup);
2742EXPORT_SYMBOL(ppp_register_compressor);
2743EXPORT_SYMBOL(ppp_unregister_compressor);
2744MODULE_LICENSE("GPL");
2745MODULE_ALIAS_CHARDEV_MAJOR(PPP_MAJOR);
2746MODULE_ALIAS("/dev/ppp");
Clone of davem's net-next-2.6 tree