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allow coexistance of N build and AC build.
[tomato.git] / release / src-rt-6.x / linux / linux-2.6 / drivers / net / ppp_generic.c
blob07745c8ccffc6a03a5b53727b919cb705fe3d9d6
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 20050110==
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/netdevice.h>
31 #include <linux/poll.h>
32 #include <linux/ppp_defs.h>
33 #include <linux/filter.h>
34 #include <linux/if_ppp.h>
35 #include <linux/ppp_channel.h>
36 #include <linux/ppp-comp.h>
37 #include <linux/skbuff.h>
38 #include <linux/rtnetlink.h>
39 #include <linux/if_arp.h>
40 #include <linux/ip.h>
41 #include <linux/tcp.h>
42 #include <linux/spinlock.h>
43 #include <linux/smp_lock.h>
44 #include <linux/rwsem.h>
45 #include <linux/stddef.h>
46 #include <linux/device.h>
47 #include <linux/mutex.h>
48 #include <net/slhc_vj.h>
49 #include <asm/atomic.h>
50
51 #define PPP_VERSION "2.4.2"
52
53 /*
54 * Network protocols we support.
55 */
56 #define NP_IP 0 /* Internet Protocol V4 */
57 #define NP_IPV6 1 /* Internet Protocol V6 */
58 #define NP_IPX 2 /* IPX protocol */
59 #define NP_AT 3 /* Appletalk protocol */
60 #define NP_MPLS_UC 4 /* MPLS unicast */
61 #define NP_MPLS_MC 5 /* MPLS multicast */
62 #define NUM_NP 6 /* Number of NPs. */
63
64 #define MPHDRLEN 6 /* multilink protocol header length */
65 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */
66 #define MIN_FRAG_SIZE 64
67
68 /*
69 * An instance of /dev/ppp can be associated with either a ppp
70 * interface unit or a ppp channel. In both cases, file->private_data
71 * points to one of these.
72 */
73 struct ppp_file {
74 enum {
75 INTERFACE=1, CHANNEL
76 } kind;
77 struct sk_buff_head xq; /* pppd transmit queue */
78 struct sk_buff_head rq; /* receive queue for pppd */
79 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */
80 atomic_t refcnt; /* # refs (incl /dev/ppp attached) */
81 int hdrlen; /* space to leave for headers */
82 int index; /* interface unit / channel number */
83 int dead; /* unit/channel has been shut down */
84 };
85
86 #define PF_TO_X(pf, X) ((X *)((char *)(pf) - offsetof(X, file)))
87
88 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
89 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
90
91 #define ROUNDUP(n, x) (((n) + (x) - 1) / (x))
92
93 /*
94 * Data structure describing one ppp unit.
95 * A ppp unit corresponds to a ppp network interface device
96 * and represents a multilink bundle.
97 * It can have 0 or more ppp channels connected to it.
98 */
99 struct ppp {
100 struct ppp_file file; /* stuff for read/write/poll 0 */
101 struct file *owner; /* file that owns this unit 48 */
102 struct list_head channels; /* list of attached channels 4c */
103 int n_channels; /* how many channels are attached 54 */
104 spinlock_t rlock; /* lock for receive side 58 */
105 spinlock_t wlock; /* lock for transmit side 5c */
106 int mru; /* max receive unit 60 */
107 int mru_alloc; /* MAX(1500,MRU) for dev_alloc_skb() */
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 */
152 struct 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
188 struct cardmap {
189 int shift;
190 unsigned long inuse;
191 struct cardmap *parent;
192 void *ptr[CARDMAP_WIDTH];
193 };
194 static void *cardmap_get(struct cardmap *map, unsigned int nr);
195 static int cardmap_set(struct cardmap **map, unsigned int nr, void *ptr);
196 static unsigned int cardmap_find_first_free(struct cardmap *map);
197 static void cardmap_destroy(struct cardmap **map);
198
199 /*
200 * all_ppp_mutex 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 */
204 static DEFINE_MUTEX(all_ppp_mutex);
205 static struct cardmap *all_ppp_units;
206 static 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 */
213 static DEFINE_SPINLOCK(all_channels_lock);
214 static LIST_HEAD(all_channels);
215 static LIST_HEAD(new_channels);
216 static int last_channel_index;
217 static 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 // zzz
223 #define IP_PROTO(skb) (skb)->data[11]
224 #define SRC_PORT(skb) (((skb)->data[22] << 8) + (skb)->data[23])
225 #define DST_PORT(skb) (((skb)->data[24] << 8) + (skb)->data[25])
226
227 /* We limit the length of ppp->file.rq to this (arbitrary) value */
228 #define PPP_MAX_RQLEN 32
229
230 /*
231 * Maximum number of multilink fragments queued up.
232 * This has to be large enough to cope with the maximum latency of
233 * the slowest channel relative to the others. Strictly it should
234 * depend on the number of channels and their characteristics.
235 */
236 #define PPP_MP_MAX_QLEN 128
237
238 /* Multilink header bits. */
239 #define B 0x80 /* this fragment begins a packet */
240 #define E 0x40 /* this fragment ends a packet */
241
242 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */
243 #define seq_before(a, b) ((s32)((a) - (b)) < 0)
244 #define seq_after(a, b) ((s32)((a) - (b)) > 0)
245
246 /* Prototypes. */
247 static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file,
248 unsigned int cmd, unsigned long arg);
249 static void ppp_xmit_process(struct ppp *ppp);
250 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
251 static void ppp_push(struct ppp *ppp);
252 static void ppp_channel_push(struct channel *pch);
253 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
254 struct channel *pch);
255 static void ppp_receive_error(struct ppp *ppp);
256 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
257 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
258 struct sk_buff *skb);
259 #ifdef CONFIG_PPP_MULTILINK
260 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
261 struct channel *pch);
262 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
263 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
264 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
265 #endif /* CONFIG_PPP_MULTILINK */
266 static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
267 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
268 static void ppp_ccp_closed(struct ppp *ppp);
269 static struct compressor *find_compressor(int type);
270 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
271 static struct ppp *ppp_create_interface(int unit, int *retp);
272 static void init_ppp_file(struct ppp_file *pf, int kind);
273 static void ppp_shutdown_interface(struct ppp *ppp);
274 static void ppp_destroy_interface(struct ppp *ppp);
275 static struct ppp *ppp_find_unit(int unit);
276 static struct channel *ppp_find_channel(int unit);
277 static int ppp_connect_channel(struct channel *pch, int unit);
278 static int ppp_disconnect_channel(struct channel *pch);
279 static void ppp_destroy_channel(struct channel *pch);
280
281 static struct class *ppp_class;
282
283 /* Translates a PPP protocol number to a NP index (NP == network protocol) */
284 static inline int proto_to_npindex(int proto)
285 {
286 switch (proto) {
287 case PPP_IP:
288 return NP_IP;
289 case PPP_IPV6:
290 return NP_IPV6;
291 case PPP_IPX:
292 return NP_IPX;
293 case PPP_AT:
294 return NP_AT;
295 case PPP_MPLS_UC:
296 return NP_MPLS_UC;
297 case PPP_MPLS_MC:
298 return NP_MPLS_MC;
299 }
300 return -EINVAL;
301 }
302
303 /* Translates an NP index into a PPP protocol number */
304 static const int npindex_to_proto[NUM_NP] = {
305 PPP_IP,
306 PPP_IPV6,
307 PPP_IPX,
308 PPP_AT,
309 PPP_MPLS_UC,
310 PPP_MPLS_MC,
311 };
312
313 /* Translates an ethertype into an NP index */
314 static inline int ethertype_to_npindex(int ethertype)
315 {
316 switch (ethertype) {
317 case ETH_P_IP:
318 return NP_IP;
319 case ETH_P_IPV6:
320 return NP_IPV6;
321 case ETH_P_IPX:
322 return NP_IPX;
323 case ETH_P_PPPTALK:
324 case ETH_P_ATALK:
325 return NP_AT;
326 case ETH_P_MPLS_UC:
327 return NP_MPLS_UC;
328 case ETH_P_MPLS_MC:
329 return NP_MPLS_MC;
330 }
331 return -1;
332 }
333
334 /* Translates an NP index into an ethertype */
335 static const int npindex_to_ethertype[NUM_NP] = {
336 ETH_P_IP,
337 ETH_P_IPV6,
338 ETH_P_IPX,
339 ETH_P_PPPTALK,
340 ETH_P_MPLS_UC,
341 ETH_P_MPLS_MC,
342 };
343
344 /*
345 * Locking shorthand.
346 */
347 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
348 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
349 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
350 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
351 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
352 ppp_recv_lock(ppp); } while (0)
353 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
354 ppp_xmit_unlock(ppp); } while (0)
355
356 /*
357 * /dev/ppp device routines.
358 * The /dev/ppp device is used by pppd to control the ppp unit.
359 * It supports the read, write, ioctl and poll functions.
360 * Open instances of /dev/ppp can be in one of three states:
361 * unattached, attached to a ppp unit, or attached to a ppp channel.
362 */
363 static int ppp_open(struct inode *inode, struct file *file)
364 {
365 /*
366 * This could (should?) be enforced by the permissions on /dev/ppp.
367 */
368 if (!capable(CAP_NET_ADMIN))
369 return -EPERM;
370 return 0;
371 }
372
373 static int ppp_release(struct inode *inode, struct file *file)
374 {
375 struct ppp_file *pf = file->private_data;
376 struct ppp *ppp;
377
378 if (pf != 0) {
379 file->private_data = NULL;
380 if (pf->kind == INTERFACE) {
381 ppp = PF_TO_PPP(pf);
382 if (file == ppp->owner)
383 ppp_shutdown_interface(ppp);
384 }
385 if (atomic_dec_and_test(&pf->refcnt)) {
386 switch (pf->kind) {
387 case INTERFACE:
388 ppp_destroy_interface(PF_TO_PPP(pf));
389 break;
390 case CHANNEL:
391 ppp_destroy_channel(PF_TO_CHANNEL(pf));
392 break;
393 }
394 }
395 }
396 return 0;
397 }
398
399 static ssize_t ppp_read(struct file *file, char __user *buf,
400 size_t count, loff_t *ppos)
401 {
402 struct ppp_file *pf = file->private_data;
403 DECLARE_WAITQUEUE(wait, current);
404 ssize_t ret;
405 struct sk_buff *skb = NULL;
406 struct iovec iov;
407
408 ret = count;
409
410 if (pf == 0)
411 return -ENXIO;
412 add_wait_queue(&pf->rwait, &wait);
413 for (;;) {
414 set_current_state(TASK_INTERRUPTIBLE);
415 skb = skb_dequeue(&pf->rq);
416 if (skb)
417 break;
418 ret = 0;
419 if (pf->dead)
420 break;
421 if (pf->kind == INTERFACE) {
422 /*
423 * Return 0 (EOF) on an interface that has no
424 * channels connected, unless it is looping
425 * network traffic (demand mode).
426 */
427 struct ppp *ppp = PF_TO_PPP(pf);
428 if (ppp->n_channels == 0
429 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
430 break;
431 }
432 ret = -EAGAIN;
433 if (file->f_flags & O_NONBLOCK)
434 break;
435 ret = -ERESTARTSYS;
436 if (signal_pending(current))
437 break;
438 schedule();
439 }
440 set_current_state(TASK_RUNNING);
441 remove_wait_queue(&pf->rwait, &wait);
442
443 if (skb == 0)
444 goto out;
445
446 ret = -EOVERFLOW;
447 if (skb->len > count)
448 goto outf;
449 ret = -EFAULT;
450 iov.iov_base = buf;
451 iov.iov_len = count;
452 if (skb_copy_datagram_iovec(skb, 0, &iov, skb->len))
453 goto outf;
454 ret = skb->len;
455
456 outf:
457 kfree_skb(skb);
458 out:
459 return ret;
460 }
461
462 static ssize_t ppp_write(struct file *file, const char __user *buf,
463 size_t count, loff_t *ppos)
464 {
465 struct ppp_file *pf = file->private_data;
466 struct sk_buff *skb;
467 ssize_t ret;
468
469 if (pf == 0)
470 return -ENXIO;
471 ret = -ENOMEM;
472 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
473 if (skb == 0)
474 goto out;
475 skb_reserve(skb, pf->hdrlen);
476 ret = -EFAULT;
477 if (copy_from_user(skb_put(skb, count), buf, count)) {
478 kfree_skb(skb);
479 goto out;
480 }
481
482 skb_queue_tail(&pf->xq, skb);
483
484 switch (pf->kind) {
485 case INTERFACE:
486 ppp_xmit_process(PF_TO_PPP(pf));
487 break;
488 case CHANNEL:
489 ppp_channel_push(PF_TO_CHANNEL(pf));
490 break;
491 }
492
493 ret = count;
494
495 out:
496 return ret;
497 }
498
499 /* No kernel lock - fine */
500 static unsigned int ppp_poll(struct file *file, poll_table *wait)
501 {
502 struct ppp_file *pf = file->private_data;
503 unsigned int mask;
504
505 if (pf == 0)
506 return 0;
507 poll_wait(file, &pf->rwait, wait);
508 mask = POLLOUT | POLLWRNORM;
509 if (skb_peek(&pf->rq) != 0)
510 mask |= POLLIN | POLLRDNORM;
511 if (pf->dead)
512 mask |= POLLHUP;
513 else if (pf->kind == INTERFACE) {
514 /* see comment in ppp_read */
515 struct ppp *ppp = PF_TO_PPP(pf);
516 if (ppp->n_channels == 0
517 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
518 mask |= POLLIN | POLLRDNORM;
519 }
520
521 return mask;
522 }
523
524 #ifdef CONFIG_PPP_FILTER
525 static int get_filter(void __user *arg, struct sock_filter **p)
526 {
527 struct sock_fprog uprog;
528 struct sock_filter *code = NULL;
529 int len, err;
530
531 if (copy_from_user(&uprog, arg, sizeof(uprog)))
532 return -EFAULT;
533
534 if (!uprog.len) {
535 *p = NULL;
536 return 0;
537 }
538
539 len = uprog.len * sizeof(struct sock_filter);
540 code = kmalloc(len, GFP_KERNEL);
541 if (code == NULL)
542 return -ENOMEM;
543
544 if (copy_from_user(code, uprog.filter, len)) {
545 kfree(code);
546 return -EFAULT;
547 }
548
549 err = sk_chk_filter(code, uprog.len);
550 if (err) {
551 kfree(code);
552 return err;
553 }
554
555 *p = code;
556 return uprog.len;
557 }
558 #endif /* CONFIG_PPP_FILTER */
559
560 static int ppp_ioctl(struct inode *inode, struct file *file,
561 unsigned int cmd, unsigned long arg)
562 {
563 struct ppp_file *pf = file->private_data;
564 struct ppp *ppp;
565 int err = -EFAULT, val, val2, i;
566 struct ppp_idle idle;
567 struct npioctl npi;
568 int unit, cflags;
569 struct slcompress *vj;
570 void __user *argp = (void __user *)arg;
571 int __user *p = argp;
572
573 if (pf == 0)
574 return ppp_unattached_ioctl(pf, file, cmd, arg);
575
576 if (cmd == PPPIOCDETACH) {
577 /*
578 * We have to be careful here... if the file descriptor
579 * has been dup'd, we could have another process in the
580 * middle of a poll using the same file *, so we had
581 * better not free the interface data structures -
582 * instead we fail the ioctl. Even in this case, we
583 * shut down the interface if we are the owner of it.
584 * Actually, we should get rid of PPPIOCDETACH, userland
585 * (i.e. pppd) could achieve the same effect by closing
586 * this fd and reopening /dev/ppp.
587 */
588 err = -EINVAL;
589 if (pf->kind == INTERFACE) {
590 ppp = PF_TO_PPP(pf);
591 if (file == ppp->owner)
592 ppp_shutdown_interface(ppp);
593 }
594 if (atomic_read(&file->f_count) <= 2) {
595 ppp_release(inode, file);
596 err = 0;
597 } else
598 printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%d\n",
599 atomic_read(&file->f_count));
600 return err;
601 }
602
603 if (pf->kind == CHANNEL) {
604 struct channel *pch = PF_TO_CHANNEL(pf);
605 struct ppp_channel *chan;
606
607 switch (cmd) {
608 case PPPIOCCONNECT:
609 if (get_user(unit, p))
610 break;
611 err = ppp_connect_channel(pch, unit);
612 break;
613
614 case PPPIOCDISCONN:
615 err = ppp_disconnect_channel(pch);
616 break;
617
618 default:
619 down_read(&pch->chan_sem);
620 chan = pch->chan;
621 err = -ENOTTY;
622 if (chan && chan->ops->ioctl)
623 err = chan->ops->ioctl(chan, cmd, arg);
624 up_read(&pch->chan_sem);
625 }
626 return err;
627 }
628
629 if (pf->kind != INTERFACE) {
630 /* can't happen */
631 printk(KERN_ERR "PPP: not interface or channel??\n");
632 return -EINVAL;
633 }
634
635 ppp = PF_TO_PPP(pf);
636 switch (cmd) {
637 case PPPIOCSMRU:
638 if (get_user(val, p))
639 break;
640 ppp->mru_alloc = ppp->mru = val;
641 if (ppp->mru_alloc < PPP_MRU)
642 ppp->mru_alloc = PPP_MRU; /* increase for broken peers */
643 err = 0;
644 break;
645
646 case PPPIOCSFLAGS:
647 if (get_user(val, p))
648 break;
649 ppp_lock(ppp);
650 cflags = ppp->flags & ~val;
651 ppp->flags = val & SC_FLAG_BITS;
652 ppp_unlock(ppp);
653 if (cflags & SC_CCP_OPEN)
654 ppp_ccp_closed(ppp);
655 err = 0;
656 break;
657
658 case PPPIOCGFLAGS:
659 val = ppp->flags | ppp->xstate | ppp->rstate;
660 if (put_user(val, p))
661 break;
662 err = 0;
663 break;
664
665 case PPPIOCSCOMPRESS:
666 err = ppp_set_compress(ppp, arg);
667 break;
668
669 case PPPIOCGUNIT:
670 if (put_user(ppp->file.index, p))
671 break;
672 err = 0;
673 break;
674
675 case PPPIOCSDEBUG:
676 if (get_user(val, p))
677 break;
678 ppp->debug = val;
679 err = 0;
680 break;
681
682 case PPPIOCGDEBUG:
683 if (put_user(ppp->debug, p))
684 break;
685 err = 0;
686 break;
687
688 case PPPIOCGIDLE:
689 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
690 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
691 if (copy_to_user(argp, &idle, sizeof(idle)))
692 break;
693 err = 0;
694 break;
695
696 case PPPIOCSMAXCID:
697 if (get_user(val, p))
698 break;
699 val2 = 15;
700 if ((val >> 16) != 0) {
701 val2 = val >> 16;
702 val &= 0xffff;
703 }
704 vj = slhc_init(val2+1, val+1);
705 if (vj == 0) {
706 printk(KERN_ERR "PPP: no memory (VJ compressor)\n");
707 err = -ENOMEM;
708 break;
709 }
710 ppp_lock(ppp);
711 if (ppp->vj != 0)
712 slhc_free(ppp->vj);
713 ppp->vj = vj;
714 ppp_unlock(ppp);
715 err = 0;
716 break;
717
718 case PPPIOCGNPMODE:
719 case PPPIOCSNPMODE:
720 if (copy_from_user(&npi, argp, sizeof(npi)))
721 break;
722 err = proto_to_npindex(npi.protocol);
723 if (err < 0)
724 break;
725 i = err;
726 if (cmd == PPPIOCGNPMODE) {
727 err = -EFAULT;
728 npi.mode = ppp->npmode[i];
729 if (copy_to_user(argp, &npi, sizeof(npi)))
730 break;
731 } else {
732 ppp->npmode[i] = npi.mode;
733 /* we may be able to transmit more packets now (??) */
734 netif_wake_queue(ppp->dev);
735 }
736 err = 0;
737 break;
738
739 #ifdef CONFIG_PPP_FILTER
740 case PPPIOCSPASS:
741 {
742 struct sock_filter *code;
743 err = get_filter(argp, &code);
744 if (err >= 0) {
745 ppp_lock(ppp);
746 kfree(ppp->pass_filter);
747 ppp->pass_filter = code;
748 ppp->pass_len = err;
749 ppp_unlock(ppp);
750 err = 0;
751 }
752 break;
753 }
754 case PPPIOCSACTIVE:
755 {
756 struct sock_filter *code;
757 err = get_filter(argp, &code);
758 if (err >= 0) {
759 ppp_lock(ppp);
760 kfree(ppp->active_filter);
761 ppp->active_filter = code;
762 ppp->active_len = err;
763 ppp_unlock(ppp);
764 err = 0;
765 }
766 break;
767 }
768 #endif /* CONFIG_PPP_FILTER */
769
770 #ifdef CONFIG_PPP_MULTILINK
771 case PPPIOCSMRRU:
772 if (get_user(val, p))
773 break;
774 ppp_recv_lock(ppp);
775 ppp->mrru = val;
776 ppp_recv_unlock(ppp);
777 err = 0;
778 break;
779 #endif /* CONFIG_PPP_MULTILINK */
780
781 default:
782 err = -ENOTTY;
783 }
784
785 return err;
786 }
787
788 static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file,
789 unsigned int cmd, unsigned long arg)
790 {
791 int unit, err = -EFAULT;
792 struct ppp *ppp;
793 struct channel *chan;
794 int __user *p = (int __user *)arg;
795
796 switch (cmd) {
797 case PPPIOCNEWUNIT:
798 /* Create a new ppp unit */
799 if (get_user(unit, p))
800 break;
801 ppp = ppp_create_interface(unit, &err);
802 if (ppp == 0)
803 break;
804 file->private_data = &ppp->file;
805 ppp->owner = file;
806 err = -EFAULT;
807 if (put_user(ppp->file.index, p))
808 break;
809 err = 0;
810 break;
811
812 case PPPIOCATTACH:
813 /* Attach to an existing ppp unit */
814 if (get_user(unit, p))
815 break;
816 mutex_lock(&all_ppp_mutex);
817 err = -ENXIO;
818 ppp = ppp_find_unit(unit);
819 if (ppp != 0) {
820 atomic_inc(&ppp->file.refcnt);
821 file->private_data = &ppp->file;
822 err = 0;
823 }
824 mutex_unlock(&all_ppp_mutex);
825 break;
826
827 case PPPIOCATTCHAN:
828 if (get_user(unit, p))
829 break;
830 spin_lock_bh(&all_channels_lock);
831 err = -ENXIO;
832 chan = ppp_find_channel(unit);
833 if (chan != 0) {
834 atomic_inc(&chan->file.refcnt);
835 file->private_data = &chan->file;
836 err = 0;
837 }
838 spin_unlock_bh(&all_channels_lock);
839 break;
840
841 default:
842 err = -ENOTTY;
843 }
844 return err;
845 }
846
847 static const struct file_operations ppp_device_fops = {
848 .owner = THIS_MODULE,
849 .read = ppp_read,
850 .write = ppp_write,
851 .poll = ppp_poll,
852 .ioctl = ppp_ioctl,
853 .open = ppp_open,
854 .release = ppp_release
855 };
856
857 #define PPP_MAJOR 108
858
859 /* Called at boot time if ppp is compiled into the kernel,
860 or at module load time (from init_module) if compiled as a module. */
861 static int __init ppp_init(void)
862 {
863 int err;
864
865 printk(KERN_INFO "PPP generic driver version " PPP_VERSION "\n");
866 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
867 if (!err) {
868 ppp_class = class_create(THIS_MODULE, "ppp");
869 if (IS_ERR(ppp_class)) {
870 err = PTR_ERR(ppp_class);
871 goto out_chrdev;
872 }
873 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), "ppp");
874 }
875
876 out:
877 if (err)
878 printk(KERN_ERR "failed to register PPP device (%d)\n", err);
879 return err;
880
881 out_chrdev:
882 unregister_chrdev(PPP_MAJOR, "ppp");
883 goto out;
884 }
885
886 /*
887 * Network interface unit routines.
888 */
889 static int
890 ppp_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_cow_head(skb, PPP_HDRLEN))
916 goto outf;
917
918 pp = skb_push(skb, 2);
919 proto = npindex_to_proto[npi];
920 pp[0] = proto >> 8;
921 pp[1] = proto;
922
923 netif_stop_queue(dev);
924 skb_queue_tail(&ppp->file.xq, skb);
925 ppp_xmit_process(ppp);
926 return 0;
927
928 outf:
929 kfree_skb(skb);
930 ++ppp->stats.tx_dropped;
931 return 0;
932 }
933
934 static struct net_device_stats *
935 ppp_net_stats(struct net_device *dev)
936 {
937 struct ppp *ppp = (struct ppp *) dev->priv;
938
939 return &ppp->stats;
940 }
941
942 static int
943 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
944 {
945 struct ppp *ppp = dev->priv;
946 int err = -EFAULT;
947 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
948 struct ppp_stats stats;
949 struct ppp_comp_stats cstats;
950 char *vers;
951
952 switch (cmd) {
953 case SIOCGPPPSTATS:
954 ppp_get_stats(ppp, &stats);
955 if (copy_to_user(addr, &stats, sizeof(stats)))
956 break;
957 err = 0;
958 break;
959
960 case SIOCGPPPCSTATS:
961 memset(&cstats, 0, sizeof(cstats));
962 if (ppp->xc_state != 0)
963 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
964 if (ppp->rc_state != 0)
965 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
966 if (copy_to_user(addr, &cstats, sizeof(cstats)))
967 break;
968 err = 0;
969 break;
970
971 case SIOCGPPPVER:
972 vers = PPP_VERSION;
973 if (copy_to_user(addr, vers, strlen(vers) + 1))
974 break;
975 err = 0;
976 break;
977
978 default:
979 err = -EINVAL;
980 }
981
982 return err;
983 }
984
985 static void ppp_setup(struct net_device *dev)
986 {
987 dev->hard_header_len = PPP_HDRLEN;
988 dev->mtu = PPP_MTU;
989 dev->addr_len = 0;
990 dev->tx_queue_len = 3;
991 dev->type = ARPHRD_PPP;
992 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
993 }
994
995 /*
996 * Transmit-side routines.
997 */
998
999 /*
1000 * Called to do any work queued up on the transmit side
1001 * that can now be done.
1002 */
1003 static void
1004 ppp_xmit_process(struct ppp *ppp)
1005 {
1006 struct sk_buff *skb;
1007
1008 ppp_xmit_lock(ppp);
1009 if (ppp->dev != 0) {
1010 ppp_push(ppp);
1011 while (ppp->xmit_pending == 0
1012 && (skb = skb_dequeue(&ppp->file.xq)) != 0)
1013 ppp_send_frame(ppp, skb);
1014 /* If there's no work left to do, tell the core net
1015 code that we can accept some more. */
1016 if (ppp->xmit_pending == 0 && skb_peek(&ppp->file.xq) == 0)
1017 netif_wake_queue(ppp->dev);
1018 }
1019 ppp_xmit_unlock(ppp);
1020 }
1021
1022 /*
1023 * Compress and send a frame.
1024 * The caller should have locked the xmit path,
1025 * and xmit_pending should be 0.
1026 */
1027 static void
1028 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1029 {
1030 int proto = PPP_PROTO(skb);
1031 struct sk_buff *new_skb;
1032 int len;
1033 unsigned char *cp;
1034
1035 if (proto < 0x8000) {
1036 #ifdef CONFIG_PPP_FILTER
1037 /* check if we should pass this packet */
1038 /* the filter instructions are constructed assuming
1039 a four-byte PPP header on each packet */
1040 *skb_push(skb, 2) = 1;
1041 if (ppp->pass_filter
1042 && sk_run_filter(skb, ppp->pass_filter,
1043 ppp->pass_len) == 0) {
1044 if (ppp->debug & 1)
1045 printk(KERN_DEBUG "PPP: outbound frame not passed\n");
1046 kfree_skb(skb);
1047 return;
1048 }
1049 /* if this packet passes the active filter, record the time */
1050 if (!(ppp->active_filter
1051 && sk_run_filter(skb, ppp->active_filter,
1052 ppp->active_len) == 0))
1053 ppp->last_xmit = jiffies;
1054 skb_pull(skb, 2);
1055 #else
1056
1057 #if 1 // zzz
1058 switch (IP_PROTO(skb)) {
1059 case 6: // TCP
1060 switch (DST_PORT(skb)) {
1061 case 139: // netbios-ssn
1062 case 445: // microsoft-ds
1063 break;
1064 default:
1065 ppp->last_xmit = jiffies;
1066 break;
1067 }
1068 break;
1069 case 17: // UDP
1070 switch (DST_PORT(skb)) {
1071 case 137: // netbios-ns
1072 case 138: // netbios-dgm
1073 break;
1074 default:
1075 ppp->last_xmit = jiffies;
1076 break;
1077 }
1078 break;
1079 default:
1080 ppp->last_xmit = jiffies;
1081 break;
1082 }
1083 #else
1084 /* for data packets, record the time */
1085 ppp->last_xmit = jiffies;
1086 #endif
1087 #endif /* CONFIG_PPP_FILTER */
1088 }
1089
1090 ++ppp->stats.tx_packets;
1091 ppp->stats.tx_bytes += skb->len - 2;
1092
1093 switch (proto) {
1094 case PPP_IP:
1095 if (ppp->vj == 0 || (ppp->flags & SC_COMP_TCP) == 0)
1096 break;
1097 /* try to do VJ TCP header compression */
1098 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1099 GFP_ATOMIC);
1100 if (new_skb == 0) {
1101 printk(KERN_ERR "PPP: no memory (VJ comp pkt)\n");
1102 goto drop;
1103 }
1104 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1105 cp = skb->data + 2;
1106 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1107 new_skb->data + 2, &cp,
1108 !(ppp->flags & SC_NO_TCP_CCID));
1109 if (cp == skb->data + 2) {
1110 /* didn't compress */
1111 kfree_skb(new_skb);
1112 } else {
1113 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1114 proto = PPP_VJC_COMP;
1115 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1116 } else {
1117 proto = PPP_VJC_UNCOMP;
1118 cp[0] = skb->data[2];
1119 }
1120 kfree_skb(skb);
1121 skb = new_skb;
1122 cp = skb_put(skb, len + 2);
1123 cp[0] = 0;
1124 cp[1] = proto;
1125 }
1126 break;
1127
1128 case PPP_CCP:
1129 /* peek at outbound CCP frames */
1130 ppp_ccp_peek(ppp, skb, 0);
1131 /*
1132 * When LZS or MPPE/MPPC has been negotiated we don't send
1133 * CCP_RESETACK after receiving CCP_RESETREQ; in fact pppd
1134 * sends such a packet but we silently discard it here
1135 */
1136 if (CCP_CODE(skb->data+2) == CCP_RESETACK
1137 && (ppp->xcomp->compress_proto == CI_MPPE
1138 || ppp->xcomp->compress_proto == CI_LZS)) {
1139 --ppp->stats.tx_packets;
1140 ppp->stats.tx_bytes -= skb->len - 2;
1141 kfree_skb(skb);
1142 return;
1143 }
1144 break;
1145 }
1146
1147 /* try to do packet compression */
1148 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state != 0
1149 && proto != PPP_LCP && proto != PPP_CCP) {
1150 int comp_ovhd = 0;
1151 /*
1152 * because of possible data expansion when MPPC or LZS
1153 * is used, allocate compressor's buffer 12.5% bigger
1154 * than MTU
1155 */
1156 if (ppp->xcomp->compress_proto == CI_MPPE)
1157 comp_ovhd = ((ppp->dev->mtu * 9) / 8) + 1 + MPPE_OVHD;
1158 else if (ppp->xcomp->compress_proto == CI_LZS)
1159 comp_ovhd = ((ppp->dev->mtu * 9) / 8) + 1 + LZS_OVHD;
1160 new_skb = alloc_skb(ppp->dev->mtu + ppp->dev->hard_header_len
1161 + comp_ovhd, GFP_ATOMIC);
1162 if (new_skb == 0) {
1163 printk(KERN_ERR "PPP: no memory (comp pkt)\n");
1164 goto drop;
1165 }
1166 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1167 skb_reserve(new_skb,
1168 ppp->dev->hard_header_len - PPP_HDRLEN);
1169
1170 /* compressor still expects A/C bytes in hdr */
1171 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1172 new_skb->data, skb->len + 2,
1173 ppp->dev->mtu + PPP_HDRLEN);
1174 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1175 kfree_skb(skb);
1176 skb = new_skb;
1177 skb_put(skb, len);
1178 skb_pull(skb, 2); /* pull off A/C bytes */
1179 } else if (len == 0) {
1180 /* didn't compress, or CCP not up yet */
1181 kfree_skb(new_skb);
1182 } else {
1183 /*
1184 * (len < 0)
1185 * MPPE requires that we do not send unencrypted
1186 * frames. The compressor will return -1 if we
1187 * should drop the frame. We cannot simply test
1188 * the compress_proto because MPPE and MPPC share
1189 * the same number.
1190 */
1191 printk(KERN_ERR "ppp: compressor dropped pkt\n");
1192 kfree_skb(new_skb);
1193 goto drop;
1194 }
1195 }
1196
1197 /*
1198 * If we are waiting for traffic (demand dialling),
1199 * queue it up for pppd to receive.
1200 */
1201 if (ppp->flags & SC_LOOP_TRAFFIC) {
1202 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1203 goto drop;
1204 skb_queue_tail(&ppp->file.rq, skb);
1205 wake_up_interruptible(&ppp->file.rwait);
1206 return;
1207 }
1208
1209 ppp->xmit_pending = skb;
1210 ppp_push(ppp);
1211 return;
1212
1213 drop:
1214 kfree_skb(skb);
1215 ++ppp->stats.tx_errors;
1216 }
1217
1218 /*
1219 * Try to send the frame in xmit_pending.
1220 * The caller should have the xmit path locked.
1221 */
1222 static void
1223 ppp_push(struct ppp *ppp)
1224 {
1225 struct list_head *list;
1226 struct channel *pch;
1227 struct sk_buff *skb = ppp->xmit_pending;
1228
1229 if (skb == 0)
1230 return;
1231
1232 list = &ppp->channels;
1233 if (list_empty(list)) {
1234 /* nowhere to send the packet, just drop it */
1235 ppp->xmit_pending = NULL;
1236 kfree_skb(skb);
1237 return;
1238 }
1239
1240 if ((ppp->flags & SC_MULTILINK) == 0) {
1241 /* not doing multilink: send it down the first channel */
1242 list = list->next;
1243 pch = list_entry(list, struct channel, clist);
1244
1245 spin_lock_bh(&pch->downl);
1246 if (pch->chan) {
1247 if (pch->chan->ops->start_xmit(pch->chan, skb))
1248 ppp->xmit_pending = NULL;
1249 } else {
1250 /* channel got unregistered */
1251 kfree_skb(skb);
1252 ppp->xmit_pending = NULL;
1253 }
1254 spin_unlock_bh(&pch->downl);
1255 return;
1256 }
1257
1258 #ifdef CONFIG_PPP_MULTILINK
1259 /* Multilink: fragment the packet over as many links
1260 as can take the packet at the moment. */
1261 if (!ppp_mp_explode(ppp, skb))
1262 return;
1263 #endif /* CONFIG_PPP_MULTILINK */
1264
1265 ppp->xmit_pending = NULL;
1266 kfree_skb(skb);
1267 }
1268
1269 #ifdef CONFIG_PPP_MULTILINK
1270 /*
1271 * Divide a packet to be transmitted into fragments and
1272 * send them out the individual links.
1273 */
1274 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1275 {
1276 int len, fragsize;
1277 int i, bits, hdrlen, mtu;
1278 int flen;
1279 int navail, nfree;
1280 int nbigger;
1281 unsigned char *p, *q;
1282 struct list_head *list;
1283 struct channel *pch;
1284 struct sk_buff *frag;
1285 struct ppp_channel *chan;
1286
1287 nfree = 0; /* # channels which have no packet already queued */
1288 navail = 0; /* total # of usable channels (not deregistered) */
1289 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1290 i = 0;
1291 list_for_each_entry(pch, &ppp->channels, clist) {
1292 navail += pch->avail = (pch->chan != NULL);
1293 if (pch->avail) {
1294 if (skb_queue_empty(&pch->file.xq) ||
1295 !pch->had_frag) {
1296 pch->avail = 2;
1297 ++nfree;
1298 }
1299 if (!pch->had_frag && i < ppp->nxchan)
1300 ppp->nxchan = i;
1301 }
1302 ++i;
1303 }
1304
1305 /*
1306 * Don't start sending this packet unless at least half of
1307 * the channels are free. This gives much better TCP
1308 * performance if we have a lot of channels.
1309 */
1310 if (nfree == 0 || nfree < navail / 2)
1311 return 0; /* can't take now, leave it in xmit_pending */
1312
1313 /* Do protocol field compression (XXX this should be optional) */
1314 p = skb->data;
1315 len = skb->len;
1316 if (*p == 0) {
1317 ++p;
1318 --len;
1319 }
1320
1321 /*
1322 * Decide on fragment size.
1323 * We create a fragment for each free channel regardless of
1324 * how small they are (i.e. even 0 length) in order to minimize
1325 * the time that it will take to detect when a channel drops
1326 * a fragment.
1327 */
1328 fragsize = len;
1329 if (nfree > 1)
1330 fragsize = DIV_ROUND_UP(fragsize, nfree);
1331 /* nbigger channels get fragsize bytes, the rest get fragsize-1,
1332 except if nbigger==0, then they all get fragsize. */
1333 nbigger = len % nfree;
1334
1335 /* skip to the channel after the one we last used
1336 and start at that one */
1337 list = &ppp->channels;
1338 for (i = 0; i < ppp->nxchan; ++i) {
1339 list = list->next;
1340 if (list == &ppp->channels) {
1341 i = 0;
1342 break;
1343 }
1344 }
1345
1346 /* create a fragment for each channel */
1347 bits = B;
1348 while (nfree > 0 || len > 0) {
1349 list = list->next;
1350 if (list == &ppp->channels) {
1351 i = 0;
1352 continue;
1353 }
1354 pch = list_entry(list, struct channel, clist);
1355 ++i;
1356 if (!pch->avail)
1357 continue;
1358
1359 /*
1360 * Skip this channel if it has a fragment pending already and
1361 * we haven't given a fragment to all of the free channels.
1362 */
1363 if (pch->avail == 1) {
1364 if (nfree > 0)
1365 continue;
1366 } else {
1367 --nfree;
1368 pch->avail = 1;
1369 }
1370
1371 /* check the channel's mtu and whether it is still attached. */
1372 spin_lock_bh(&pch->downl);
1373 if (pch->chan == NULL) {
1374 /* can't use this channel, it's being deregistered */
1375 spin_unlock_bh(&pch->downl);
1376 pch->avail = 0;
1377 if (--navail == 0)
1378 break;
1379 continue;
1380 }
1381
1382 /*
1383 * Create a fragment for this channel of
1384 * min(max(mtu+2-hdrlen, 4), fragsize, len) bytes.
1385 * If mtu+2-hdrlen < 4, that is a ridiculously small
1386 * MTU, so we use mtu = 2 + hdrlen.
1387 */
1388 if (fragsize > len)
1389 fragsize = len;
1390 flen = fragsize;
1391 mtu = pch->chan->mtu + 2 - hdrlen;
1392 if (mtu < 4)
1393 mtu = 4;
1394 if (flen > mtu)
1395 flen = mtu;
1396 if (flen == len && nfree == 0)
1397 bits |= E;
1398 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1399 if (frag == 0)
1400 goto noskb;
1401 q = skb_put(frag, flen + hdrlen);
1402
1403 /* make the MP header */
1404 q[0] = PPP_MP >> 8;
1405 q[1] = PPP_MP;
1406 if (ppp->flags & SC_MP_XSHORTSEQ) {
1407 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1408 q[3] = ppp->nxseq;
1409 } else {
1410 q[2] = bits;
1411 q[3] = ppp->nxseq >> 16;
1412 q[4] = ppp->nxseq >> 8;
1413 q[5] = ppp->nxseq;
1414 }
1415
1416 /*
1417 * Copy the data in.
1418 * Unfortunately there is a bug in older versions of
1419 * the Linux PPP multilink reconstruction code where it
1420 * drops 0-length fragments. Therefore we make sure the
1421 * fragment has at least one byte of data. Any bytes
1422 * we add in this situation will end up as padding on the
1423 * end of the reconstructed packet.
1424 */
1425 if (flen == 0)
1426 *skb_put(frag, 1) = 0;
1427 else
1428 memcpy(q + hdrlen, p, flen);
1429
1430 /* try to send it down the channel */
1431 chan = pch->chan;
1432 if (!skb_queue_empty(&pch->file.xq) ||
1433 !chan->ops->start_xmit(chan, frag))
1434 skb_queue_tail(&pch->file.xq, frag);
1435 pch->had_frag = 1;
1436 p += flen;
1437 len -= flen;
1438 ++ppp->nxseq;
1439 bits = 0;
1440 spin_unlock_bh(&pch->downl);
1441
1442 if (--nbigger == 0 && fragsize > 0)
1443 --fragsize;
1444 }
1445 ppp->nxchan = i;
1446
1447 return 1;
1448
1449 noskb:
1450 spin_unlock_bh(&pch->downl);
1451 if (ppp->debug & 1)
1452 printk(KERN_ERR "PPP: no memory (fragment)\n");
1453 ++ppp->stats.tx_errors;
1454 ++ppp->nxseq;
1455 return 1; /* abandon the frame */
1456 }
1457 #endif /* CONFIG_PPP_MULTILINK */
1458
1459 /*
1460 * Try to send data out on a channel.
1461 */
1462 static void
1463 ppp_channel_push(struct channel *pch)
1464 {
1465 struct sk_buff *skb;
1466 struct ppp *ppp;
1467
1468 spin_lock_bh(&pch->downl);
1469 if (pch->chan != 0) {
1470 while (!skb_queue_empty(&pch->file.xq)) {
1471 skb = skb_dequeue(&pch->file.xq);
1472 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1473 /* put the packet back and try again later */
1474 skb_queue_head(&pch->file.xq, skb);
1475 break;
1476 }
1477 }
1478 } else {
1479 /* channel got deregistered */
1480 skb_queue_purge(&pch->file.xq);
1481 }
1482 spin_unlock_bh(&pch->downl);
1483 /* see if there is anything from the attached unit to be sent */
1484 if (skb_queue_empty(&pch->file.xq)) {
1485 read_lock_bh(&pch->upl);
1486 ppp = pch->ppp;
1487 if (ppp != 0)
1488 ppp_xmit_process(ppp);
1489 read_unlock_bh(&pch->upl);
1490 }
1491 }
1492
1493 /*
1494 * Receive-side routines.
1495 */
1496
1497 /* misuse a few fields of the skb for MP reconstruction */
1498 #define sequence priority
1499 #define BEbits cb[0]
1500
1501 static inline void
1502 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1503 {
1504 ppp_recv_lock(ppp);
1505 /* ppp->dev == 0 means interface is closing down */
1506 if (ppp->dev != 0)
1507 ppp_receive_frame(ppp, skb, pch);
1508 else
1509 kfree_skb(skb);
1510 ppp_recv_unlock(ppp);
1511 }
1512
1513 void
1514 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1515 {
1516 struct channel *pch = chan->ppp;
1517 int proto;
1518
1519 if (!pch) {
1520 kfree_skb(skb);
1521 return;
1522 }
1523
1524 read_lock_bh(&pch->upl);
1525 if (!pskb_may_pull(skb, 2)) {
1526 kfree_skb(skb);
1527 if (pch->ppp) {
1528 ++pch->ppp->stats.rx_length_errors;
1529 ppp_receive_error(pch->ppp);
1530 }
1531 goto done;
1532 }
1533
1534 proto = PPP_PROTO(skb);
1535 if (pch->ppp == 0 || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1536 /* put it on the channel queue */
1537 skb_queue_tail(&pch->file.rq, skb);
1538 /* drop old frames if queue too long */
1539 while (pch->file.rq.qlen > PPP_MAX_RQLEN
1540 && (skb = skb_dequeue(&pch->file.rq)) != 0)
1541 kfree_skb(skb);
1542 wake_up_interruptible(&pch->file.rwait);
1543 } else {
1544 ppp_do_recv(pch->ppp, skb, pch);
1545 }
1546
1547 done:
1548 read_unlock_bh(&pch->upl);
1549 }
1550
1551 /* Put a 0-length skb in the receive queue as an error indication */
1552 void
1553 ppp_input_error(struct ppp_channel *chan, int code)
1554 {
1555 struct channel *pch = chan->ppp;
1556 struct sk_buff *skb;
1557
1558 if (pch == 0)
1559 return;
1560
1561 read_lock_bh(&pch->upl);
1562 if (pch->ppp != 0) {
1563 skb = alloc_skb(0, GFP_ATOMIC);
1564 if (skb != 0) {
1565 skb->len = 0; /* probably unnecessary */
1566 skb->cb[0] = code;
1567 ppp_do_recv(pch->ppp, skb, pch);
1568 }
1569 }
1570 read_unlock_bh(&pch->upl);
1571 }
1572
1573 /*
1574 * We come in here to process a received frame.
1575 * The receive side of the ppp unit is locked.
1576 */
1577 static void
1578 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1579 {
1580 /* note: a 0-length skb is used as an error indication */
1581 if (skb->len > 0) {
1582 #ifdef CONFIG_PPP_MULTILINK
1583 /* XXX do channel-level decompression here */
1584 if (PPP_PROTO(skb) == PPP_MP)
1585 ppp_receive_mp_frame(ppp, skb, pch);
1586 else
1587 #endif /* CONFIG_PPP_MULTILINK */
1588 ppp_receive_nonmp_frame(ppp, skb);
1589 } else {
1590 kfree_skb(skb);
1591 ppp_receive_error(ppp);
1592 }
1593 }
1594
1595 static void
1596 ppp_receive_error(struct ppp *ppp)
1597 {
1598 ++ppp->stats.rx_errors;
1599 if (ppp->vj != 0)
1600 slhc_toss(ppp->vj);
1601 }
1602
1603 static void
1604 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1605 {
1606 struct sk_buff *ns;
1607 int proto, len, npi;
1608
1609 /*
1610 * Decompress the frame, if compressed.
1611 * Note that some decompressors need to see uncompressed frames
1612 * that come in as well as compressed frames.
1613 */
1614 if (ppp->rc_state != 0 && (ppp->rstate & SC_DECOMP_RUN)
1615 && (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1616 skb = ppp_decompress_frame(ppp, skb);
1617
1618 proto = PPP_PROTO(skb);
1619 switch (proto) {
1620 case PPP_VJC_COMP:
1621 /* decompress VJ compressed packets */
1622 if (ppp->vj == 0 || (ppp->flags & SC_REJ_COMP_TCP))
1623 goto err;
1624
1625 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1626 /* copy to a new sk_buff with more tailroom */
1627 ns = dev_alloc_skb(skb->len + 128);
1628 if (ns == 0) {
1629 printk(KERN_ERR"PPP: no memory (VJ decomp)\n");
1630 goto err;
1631 }
1632 skb_reserve(ns, 2);
1633 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1634 kfree_skb(skb);
1635 skb = ns;
1636 }
1637 else
1638 skb->ip_summed = CHECKSUM_NONE;
1639
1640 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1641 if (len <= 0) {
1642 printk(KERN_DEBUG "PPP: VJ decompression error\n");
1643 goto err;
1644 }
1645 len += 2;
1646 if (len > skb->len)
1647 skb_put(skb, len - skb->len);
1648 else if (len < skb->len)
1649 skb_trim(skb, len);
1650 proto = PPP_IP;
1651 break;
1652
1653 case PPP_VJC_UNCOMP:
1654 if (ppp->vj == 0 || (ppp->flags & SC_REJ_COMP_TCP))
1655 goto err;
1656
1657 /* Until we fix the decompressor need to make sure
1658 * data portion is linear.
1659 */
1660 if (!pskb_may_pull(skb, skb->len))
1661 goto err;
1662
1663 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1664 printk(KERN_ERR "PPP: VJ uncompressed error\n");
1665 goto err;
1666 }
1667 proto = PPP_IP;
1668 break;
1669
1670 case PPP_CCP:
1671 ppp_ccp_peek(ppp, skb, 1);
1672 break;
1673 }
1674
1675 ++ppp->stats.rx_packets;
1676 ppp->stats.rx_bytes += skb->len - 2;
1677
1678 npi = proto_to_npindex(proto);
1679 if (npi < 0) {
1680 /* control or unknown frame - pass it to pppd */
1681 skb_queue_tail(&ppp->file.rq, skb);
1682 /* limit queue length by dropping old frames */
1683 while (ppp->file.rq.qlen > PPP_MAX_RQLEN
1684 && (skb = skb_dequeue(&ppp->file.rq)) != 0)
1685 kfree_skb(skb);
1686 /* wake up any process polling or blocking on read */
1687 wake_up_interruptible(&ppp->file.rwait);
1688
1689 } else {
1690 /* network protocol frame - give it to the kernel */
1691
1692 #ifdef CONFIG_PPP_FILTER
1693 /* check if the packet passes the pass and active filters */
1694 /* the filter instructions are constructed assuming
1695 a four-byte PPP header on each packet */
1696 if (ppp->pass_filter || ppp->active_filter) {
1697 if (skb_cloned(skb) &&
1698 pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
1699 goto err;
1700
1701 *skb_push(skb, 2) = 0;
1702 if (ppp->pass_filter
1703 && sk_run_filter(skb, ppp->pass_filter,
1704 ppp->pass_len) == 0) {
1705 if (ppp->debug & 1)
1706 printk(KERN_DEBUG "PPP: inbound frame "
1707 "not passed\n");
1708 kfree_skb(skb);
1709 return;
1710 }
1711 if (!(ppp->active_filter
1712 && sk_run_filter(skb, ppp->active_filter,
1713 ppp->active_len) == 0))
1714 ppp->last_recv = jiffies;
1715 __skb_pull(skb, 2);
1716 } else
1717 #endif /* CONFIG_PPP_FILTER */
1718 ppp->last_recv = jiffies;
1719
1720 if ((ppp->dev->flags & IFF_UP) == 0
1721 || ppp->npmode[npi] != NPMODE_PASS) {
1722 kfree_skb(skb);
1723 } else {
1724 /* chop off protocol */
1725 skb_pull_rcsum(skb, 2);
1726 skb->dev = ppp->dev;
1727 skb->protocol = htons(npindex_to_ethertype[npi]);
1728 skb_reset_mac_header(skb);
1729 netif_rx(skb);
1730 ppp->dev->last_rx = jiffies;
1731 }
1732 }
1733 return;
1734
1735 err:
1736 kfree_skb(skb);
1737 ppp_receive_error(ppp);
1738 }
1739
1740 static struct sk_buff *
1741 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1742 {
1743 int proto = PPP_PROTO(skb);
1744 struct sk_buff *ns;
1745 int len;
1746
1747 /* Until we fix all the decompressor's need to make sure
1748 * data portion is linear.
1749 */
1750 if (!pskb_may_pull(skb, skb->len))
1751 goto err;
1752
1753 if (proto == PPP_COMP) {
1754 int obuff_size;
1755
1756 switch(ppp->rcomp->compress_proto) {
1757 case CI_MPPE:
1758 obuff_size = ppp->mru_alloc + PPP_HDRLEN + 1;
1759 break;
1760 default:
1761 obuff_size = ppp->mru_alloc + PPP_HDRLEN;
1762 break;
1763 }
1764
1765 ns = dev_alloc_skb(obuff_size);
1766 if (ns == 0) {
1767 printk(KERN_ERR "ppp_decompress_frame: no memory\n");
1768 goto err;
1769 }
1770 /* the decompressor still expects the A/C bytes in the hdr */
1771 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1772 skb->len + 2, ns->data, obuff_size);
1773 if (len < 0) {
1774 /* Pass the compressed frame to pppd as an
1775 error indication. */
1776 if (len == DECOMP_FATALERROR)
1777 ppp->rstate |= SC_DC_FERROR;
1778 kfree_skb(ns);
1779 goto err;
1780 }
1781
1782 kfree_skb(skb);
1783 skb = ns;
1784 skb_put(skb, len);
1785 skb_pull(skb, 2); /* pull off the A/C bytes */
1786
1787 } else {
1788 /* Uncompressed frame - pass to decompressor so it
1789 can update its dictionary if necessary. */
1790 if (ppp->rcomp->incomp)
1791 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1792 skb->len + 2);
1793 }
1794
1795 return skb;
1796
1797 err:
1798 if (ppp->rcomp->compress_proto != CI_MPPE
1799 && ppp->rcomp->compress_proto != CI_LZS) {
1800 /*
1801 * If decompression protocol isn't MPPE/MPPC or LZS, we set
1802 * SC_DC_ERROR flag and wait for CCP_RESETACK
1803 */
1804 ppp->rstate |= SC_DC_ERROR;
1805 }
1806 ppp_receive_error(ppp);
1807 return skb;
1808 }
1809
1810 #ifdef CONFIG_PPP_MULTILINK
1811 /*
1812 * Receive a multilink frame.
1813 * We put it on the reconstruction queue and then pull off
1814 * as many completed frames as we can.
1815 */
1816 static void
1817 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1818 {
1819 u32 mask, seq;
1820 struct channel *ch;
1821 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1822
1823 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
1824 goto err; /* no good, throw it away */
1825
1826 /* Decode sequence number and begin/end bits */
1827 if (ppp->flags & SC_MP_SHORTSEQ) {
1828 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1829 mask = 0xfff;
1830 } else {
1831 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1832 mask = 0xffffff;
1833 }
1834 skb->BEbits = skb->data[2];
1835 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
1836
1837 /*
1838 * Do protocol ID decompression on the first fragment of each packet.
1839 */
1840 if ((skb->BEbits & B) && (skb->data[0] & 1))
1841 *skb_push(skb, 1) = 0;
1842
1843 /*
1844 * Expand sequence number to 32 bits, making it as close
1845 * as possible to ppp->minseq.
1846 */
1847 seq |= ppp->minseq & ~mask;
1848 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
1849 seq += mask + 1;
1850 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
1851 seq -= mask + 1; /* should never happen */
1852 skb->sequence = seq;
1853 pch->lastseq = seq;
1854
1855 /*
1856 * If this packet comes before the next one we were expecting,
1857 * drop it.
1858 */
1859 if (seq_before(seq, ppp->nextseq)) {
1860 kfree_skb(skb);
1861 ++ppp->stats.rx_dropped;
1862 ppp_receive_error(ppp);
1863 return;
1864 }
1865
1866 /*
1867 * Reevaluate minseq, the minimum over all channels of the
1868 * last sequence number received on each channel. Because of
1869 * the increasing sequence number rule, we know that any fragment
1870 * before `minseq' which hasn't arrived is never going to arrive.
1871 * The list of channels can't change because we have the receive
1872 * side of the ppp unit locked.
1873 */
1874 list_for_each_entry(ch, &ppp->channels, clist) {
1875 if (seq_before(ch->lastseq, seq))
1876 seq = ch->lastseq;
1877 }
1878 if (seq_before(ppp->minseq, seq))
1879 ppp->minseq = seq;
1880
1881 /* Put the fragment on the reconstruction queue */
1882 ppp_mp_insert(ppp, skb);
1883
1884 /* If the queue is getting long, don't wait any longer for packets
1885 before the start of the queue. */
1886 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN
1887 && seq_before(ppp->minseq, ppp->mrq.next->sequence))
1888 ppp->minseq = ppp->mrq.next->sequence;
1889
1890 /* Pull completed packets off the queue and receive them. */
1891 while ((skb = ppp_mp_reconstruct(ppp)) != 0) {
1892 if (pskb_may_pull(skb, 2))
1893 ppp_receive_nonmp_frame(ppp, skb);
1894 else {
1895 ++ppp->dev->stats.rx_length_errors;
1896 kfree_skb(skb);
1897 ppp_receive_error(ppp);
1898 }
1899 }
1900
1901 return;
1902
1903 err:
1904 kfree_skb(skb);
1905 ppp_receive_error(ppp);
1906 }
1907
1908 /*
1909 * Insert a fragment on the MP reconstruction queue.
1910 * The queue is ordered by increasing sequence number.
1911 */
1912 static void
1913 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
1914 {
1915 struct sk_buff *p;
1916 struct sk_buff_head *list = &ppp->mrq;
1917 u32 seq = skb->sequence;
1918
1919 /* N.B. we don't need to lock the list lock because we have the
1920 ppp unit receive-side lock. */
1921 for (p = list->next; p != (struct sk_buff *)list; p = p->next)
1922 if (seq_before(seq, p->sequence))
1923 break;
1924 __skb_insert(skb, p->prev, p, list);
1925 }
1926
1927 /*
1928 * Reconstruct a packet from the MP fragment queue.
1929 * We go through increasing sequence numbers until we find a
1930 * complete packet, or we get to the sequence number for a fragment
1931 * which hasn't arrived but might still do so.
1932 */
1933 struct sk_buff *
1934 ppp_mp_reconstruct(struct ppp *ppp)
1935 {
1936 u32 seq = ppp->nextseq;
1937 u32 minseq = ppp->minseq;
1938 struct sk_buff_head *list = &ppp->mrq;
1939 struct sk_buff *p, *next;
1940 struct sk_buff *head, *tail;
1941 struct sk_buff *skb = NULL;
1942 int lost = 0, len = 0;
1943
1944 if (ppp->mrru == 0) /* do nothing until mrru is set */
1945 return NULL;
1946 head = list->next;
1947 tail = NULL;
1948 for (p = head; p != (struct sk_buff *) list; p = next) {
1949 next = p->next;
1950 if (seq_before(p->sequence, seq)) {
1951 /* this can't happen, anyway ignore the skb */
1952 printk(KERN_ERR "ppp_mp_reconstruct bad seq %u < %u\n",
1953 p->sequence, seq);
1954 head = next;
1955 continue;
1956 }
1957 if (p->sequence != seq) {
1958 /* Fragment `seq' is missing. If it is after
1959 minseq, it might arrive later, so stop here. */
1960 if (seq_after(seq, minseq))
1961 break;
1962 /* Fragment `seq' is lost, keep going. */
1963 lost = 1;
1964 seq = seq_before(minseq, p->sequence)?
1965 minseq + 1: p->sequence;
1966 next = p;
1967 continue;
1968 }
1969
1970 /*
1971 * At this point we know that all the fragments from
1972 * ppp->nextseq to seq are either present or lost.
1973 * Also, there are no complete packets in the queue
1974 * that have no missing fragments and end before this
1975 * fragment.
1976 */
1977
1978 /* B bit set indicates this fragment starts a packet */
1979 if (p->BEbits & B) {
1980 head = p;
1981 lost = 0;
1982 len = 0;
1983 }
1984
1985 len += p->len;
1986
1987 /* Got a complete packet yet? */
1988 if (lost == 0 && (p->BEbits & E) && (head->BEbits & B)) {
1989 if (len > ppp->mrru + 2) {
1990 ++ppp->stats.rx_length_errors;
1991 printk(KERN_DEBUG "PPP: reconstructed packet"
1992 " is too long (%d)\n", len);
1993 } else if (p == head) {
1994 /* fragment is complete packet - reuse skb */
1995 tail = p;
1996 skb = skb_get(p);
1997 break;
1998 } else if ((skb = dev_alloc_skb(len)) == NULL) {
1999 ++ppp->stats.rx_missed_errors;
2000 printk(KERN_DEBUG "PPP: no memory for "
2001 "reconstructed packet");
2002 } else {
2003 tail = p;
2004 break;
2005 }
2006 ppp->nextseq = seq + 1;
2007 }
2008
2009 /*
2010 * If this is the ending fragment of a packet,
2011 * and we haven't found a complete valid packet yet,
2012 * we can discard up to and including this fragment.
2013 */
2014 if (p->BEbits & E)
2015 head = next;
2016
2017 ++seq;
2018 }
2019
2020 /* If we have a complete packet, copy it all into one skb. */
2021 if (tail != NULL) {
2022 /* If we have discarded any fragments,
2023 signal a receive error. */
2024 if (head->sequence != ppp->nextseq) {
2025 if (ppp->debug & 1)
2026 printk(KERN_DEBUG " missed pkts %u..%u\n",
2027 ppp->nextseq, head->sequence-1);
2028 ++ppp->stats.rx_dropped;
2029 ppp_receive_error(ppp);
2030 }
2031
2032 if (head != tail)
2033 /* copy to a single skb */
2034 for (p = head; p != tail->next; p = p->next)
2035 skb_copy_bits(p, 0, skb_put(skb, p->len), p->len);
2036 ppp->nextseq = tail->sequence + 1;
2037 head = tail->next;
2038 }
2039
2040 /* Discard all the skbuffs that we have copied the data out of
2041 or that we can't use. */
2042 while ((p = list->next) != head) {
2043 __skb_unlink(p, list);
2044 kfree_skb(p);
2045 }
2046
2047 return skb;
2048 }
2049 #endif /* CONFIG_PPP_MULTILINK */
2050
2051 /*
2052 * Channel interface.
2053 */
2054
2055 /*
2056 * Create a new, unattached ppp channel.
2057 */
2058 int
2059 ppp_register_channel(struct ppp_channel *chan)
2060 {
2061 struct channel *pch;
2062
2063 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2064 if (pch == 0)
2065 return -ENOMEM;
2066 pch->ppp = NULL;
2067 pch->chan = chan;
2068 chan->ppp = pch;
2069 init_ppp_file(&pch->file, CHANNEL);
2070 pch->file.hdrlen = chan->hdrlen;
2071 #ifdef CONFIG_PPP_MULTILINK
2072 pch->lastseq = -1;
2073 #endif /* CONFIG_PPP_MULTILINK */
2074 init_rwsem(&pch->chan_sem);
2075 spin_lock_init(&pch->downl);
2076 rwlock_init(&pch->upl);
2077 spin_lock_bh(&all_channels_lock);
2078 pch->file.index = ++last_channel_index;
2079 list_add(&pch->list, &new_channels);
2080 atomic_inc(&channel_count);
2081 spin_unlock_bh(&all_channels_lock);
2082 return 0;
2083 }
2084
2085 /*
2086 * Return the index of a channel.
2087 */
2088 int ppp_channel_index(struct ppp_channel *chan)
2089 {
2090 struct channel *pch = chan->ppp;
2091
2092 if (pch != 0)
2093 return pch->file.index;
2094 return -1;
2095 }
2096
2097 /*
2098 * Return the PPP unit number to which a channel is connected.
2099 */
2100 int ppp_unit_number(struct ppp_channel *chan)
2101 {
2102 struct channel *pch = chan->ppp;
2103 int unit = -1;
2104
2105 if (pch != 0) {
2106 read_lock_bh(&pch->upl);
2107 if (pch->ppp != 0)
2108 unit = pch->ppp->file.index;
2109 read_unlock_bh(&pch->upl);
2110 }
2111 return unit;
2112 }
2113
2114 /*
2115 * Disconnect a channel from the generic layer.
2116 * This must be called in process context.
2117 */
2118 void
2119 ppp_unregister_channel(struct ppp_channel *chan)
2120 {
2121 struct channel *pch = chan->ppp;
2122
2123 if (pch == 0)
2124 return; /* should never happen */
2125 chan->ppp = NULL;
2126
2127 /*
2128 * This ensures that we have returned from any calls into the
2129 * the channel's start_xmit or ioctl routine before we proceed.
2130 */
2131 down_write(&pch->chan_sem);
2132 spin_lock_bh(&pch->downl);
2133 pch->chan = NULL;
2134 spin_unlock_bh(&pch->downl);
2135 up_write(&pch->chan_sem);
2136 ppp_disconnect_channel(pch);
2137 spin_lock_bh(&all_channels_lock);
2138 list_del(&pch->list);
2139 spin_unlock_bh(&all_channels_lock);
2140 pch->file.dead = 1;
2141 wake_up_interruptible(&pch->file.rwait);
2142 if (atomic_dec_and_test(&pch->file.refcnt))
2143 ppp_destroy_channel(pch);
2144 }
2145
2146 /*
2147 * Callback from a channel when it can accept more to transmit.
2148 * This should be called at BH/softirq level, not interrupt level.
2149 */
2150 void
2151 ppp_output_wakeup(struct ppp_channel *chan)
2152 {
2153 struct channel *pch = chan->ppp;
2154
2155 if (pch == 0)
2156 return;
2157 ppp_channel_push(pch);
2158 }
2159
2160 /*
2161 * Compression control.
2162 */
2163
2164 /* Process the PPPIOCSCOMPRESS ioctl. */
2165 static int
2166 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2167 {
2168 int err;
2169 struct compressor *cp, *ocomp;
2170 struct ppp_option_data data;
2171 void *state, *ostate;
2172 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2173
2174 err = -EFAULT;
2175 if (copy_from_user(&data, (void __user *) arg, sizeof(data))
2176 || (data.length <= CCP_MAX_OPTION_LENGTH
2177 && copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2178 goto out;
2179 err = -EINVAL;
2180 if (data.length > CCP_MAX_OPTION_LENGTH
2181 || ccp_option[1] < 2 || ccp_option[1] > data.length)
2182 goto out;
2183
2184 cp = find_compressor(ccp_option[0]);
2185 #ifdef CONFIG_KMOD
2186 if (cp == 0) {
2187 request_module("ppp-compress-%d", ccp_option[0]);
2188 cp = find_compressor(ccp_option[0]);
2189 }
2190 #endif /* CONFIG_KMOD */
2191 if (cp == 0)
2192 goto out;
2193
2194 err = -ENOBUFS;
2195 if (data.transmit) {
2196 state = cp->comp_alloc(ccp_option, data.length);
2197 if (state != 0) {
2198 ppp_xmit_lock(ppp);
2199 ppp->xstate &= ~SC_COMP_RUN;
2200 ocomp = ppp->xcomp;
2201 ostate = ppp->xc_state;
2202 ppp->xcomp = cp;
2203 ppp->xc_state = state;
2204 ppp_xmit_unlock(ppp);
2205 if (ostate != 0) {
2206 ocomp->comp_free(ostate);
2207 module_put(ocomp->owner);
2208 }
2209 err = 0;
2210 } else
2211 module_put(cp->owner);
2212
2213 } else {
2214 state = cp->decomp_alloc(ccp_option, data.length);
2215 if (state != 0) {
2216 ppp_recv_lock(ppp);
2217 ppp->rstate &= ~SC_DECOMP_RUN;
2218 ocomp = ppp->rcomp;
2219 ostate = ppp->rc_state;
2220 ppp->rcomp = cp;
2221 ppp->rc_state = state;
2222 ppp_recv_unlock(ppp);
2223 if (ostate != 0) {
2224 ocomp->decomp_free(ostate);
2225 module_put(ocomp->owner);
2226 }
2227 err = 0;
2228 } else
2229 module_put(cp->owner);
2230 }
2231
2232 out:
2233 return err;
2234 }
2235
2236 /*
2237 * Look at a CCP packet and update our state accordingly.
2238 * We assume the caller has the xmit or recv path locked.
2239 */
2240 static void
2241 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2242 {
2243 unsigned char *dp;
2244 int len;
2245
2246 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2247 return; /* no header */
2248 dp = skb->data + 2;
2249
2250 switch (CCP_CODE(dp)) {
2251 case CCP_CONFREQ:
2252
2253 /* A ConfReq starts negotiation of compression
2254 * in one direction of transmission,
2255 * and hence brings it down...but which way?
2256 *
2257 * Remember:
2258 * A ConfReq indicates what the sender would like to receive
2259 */
2260 if(inbound)
2261 /* He is proposing what I should send */
2262 ppp->xstate &= ~SC_COMP_RUN;
2263 else
2264 /* I am proposing to what he should send */
2265 ppp->rstate &= ~SC_DECOMP_RUN;
2266
2267 break;
2268
2269 case CCP_TERMREQ:
2270 case CCP_TERMACK:
2271 /*
2272 * CCP is going down, both directions of transmission
2273 */
2274 ppp->rstate &= ~SC_DECOMP_RUN;
2275 ppp->xstate &= ~SC_COMP_RUN;
2276 break;
2277
2278 case CCP_CONFACK:
2279 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2280 break;
2281 len = CCP_LENGTH(dp);
2282 if (!pskb_may_pull(skb, len + 2))
2283 return; /* too short */
2284 dp += CCP_HDRLEN;
2285 len -= CCP_HDRLEN;
2286 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2287 break;
2288 if (inbound) {
2289 /* we will start receiving compressed packets */
2290 if (ppp->rc_state == 0)
2291 break;
2292 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2293 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2294 ppp->rstate |= SC_DECOMP_RUN;
2295 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2296 }
2297 } else {
2298 /* we will soon start sending compressed packets */
2299 if (ppp->xc_state == 0)
2300 break;
2301 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2302 ppp->file.index, 0, ppp->debug))
2303 ppp->xstate |= SC_COMP_RUN;
2304 }
2305 break;
2306
2307 case CCP_RESETACK:
2308 /* reset the [de]compressor */
2309 if ((ppp->flags & SC_CCP_UP) == 0)
2310 break;
2311 if (inbound) {
2312 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2313 ppp->rcomp->decomp_reset(ppp->rc_state);
2314 ppp->rstate &= ~SC_DC_ERROR;
2315 }
2316 } else {
2317 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2318 ppp->xcomp->comp_reset(ppp->xc_state);
2319 }
2320 break;
2321 }
2322 }
2323
2324 /* Free up compression resources. */
2325 static void
2326 ppp_ccp_closed(struct ppp *ppp)
2327 {
2328 void *xstate, *rstate;
2329 struct compressor *xcomp, *rcomp;
2330
2331 ppp_lock(ppp);
2332 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2333 ppp->xstate = 0;
2334 xcomp = ppp->xcomp;
2335 xstate = ppp->xc_state;
2336 ppp->xc_state = NULL;
2337 ppp->rstate = 0;
2338 rcomp = ppp->rcomp;
2339 rstate = ppp->rc_state;
2340 ppp->rc_state = NULL;
2341 ppp_unlock(ppp);
2342
2343 if (xstate) {
2344 xcomp->comp_free(xstate);
2345 module_put(xcomp->owner);
2346 }
2347 if (rstate) {
2348 rcomp->decomp_free(rstate);
2349 module_put(rcomp->owner);
2350 }
2351 }
2352
2353 /* List of compressors. */
2354 static LIST_HEAD(compressor_list);
2355 static DEFINE_SPINLOCK(compressor_list_lock);
2356
2357 struct compressor_entry {
2358 struct list_head list;
2359 struct compressor *comp;
2360 };
2361
2362 static struct compressor_entry *
2363 find_comp_entry(int proto)
2364 {
2365 struct compressor_entry *ce;
2366
2367 list_for_each_entry(ce, &compressor_list, list) {
2368 if (ce->comp->compress_proto == proto)
2369 return ce;
2370 }
2371 return NULL;
2372 }
2373
2374 /* Register a compressor */
2375 int
2376 ppp_register_compressor(struct compressor *cp)
2377 {
2378 struct compressor_entry *ce;
2379 int ret;
2380 spin_lock(&compressor_list_lock);
2381 ret = -EEXIST;
2382 if (find_comp_entry(cp->compress_proto) != 0)
2383 goto out;
2384 ret = -ENOMEM;
2385 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2386 if (ce == 0)
2387 goto out;
2388 ret = 0;
2389 ce->comp = cp;
2390 list_add(&ce->list, &compressor_list);
2391 out:
2392 spin_unlock(&compressor_list_lock);
2393 return ret;
2394 }
2395
2396 /* Unregister a compressor */
2397 void
2398 ppp_unregister_compressor(struct compressor *cp)
2399 {
2400 struct compressor_entry *ce;
2401
2402 spin_lock(&compressor_list_lock);
2403 ce = find_comp_entry(cp->compress_proto);
2404 if (ce != 0 && ce->comp == cp) {
2405 list_del(&ce->list);
2406 kfree(ce);
2407 }
2408 spin_unlock(&compressor_list_lock);
2409 }
2410
2411 /* Find a compressor. */
2412 static struct compressor *
2413 find_compressor(int type)
2414 {
2415 struct compressor_entry *ce;
2416 struct compressor *cp = NULL;
2417
2418 spin_lock(&compressor_list_lock);
2419 ce = find_comp_entry(type);
2420 if (ce != 0) {
2421 cp = ce->comp;
2422 if (!try_module_get(cp->owner))
2423 cp = NULL;
2424 }
2425 spin_unlock(&compressor_list_lock);
2426 return cp;
2427 }
2428
2429 /*
2430 * Miscelleneous stuff.
2431 */
2432
2433 static void
2434 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2435 {
2436 struct slcompress *vj = ppp->vj;
2437
2438 memset(st, 0, sizeof(*st));
2439 st->p.ppp_ipackets = ppp->stats.rx_packets;
2440 st->p.ppp_ierrors = ppp->stats.rx_errors;
2441 st->p.ppp_ibytes = ppp->stats.rx_bytes;
2442 st->p.ppp_opackets = ppp->stats.tx_packets;
2443 st->p.ppp_oerrors = ppp->stats.tx_errors;
2444 st->p.ppp_obytes = ppp->stats.tx_bytes;
2445 if (vj == 0)
2446 return;
2447 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2448 st->vj.vjs_compressed = vj->sls_o_compressed;
2449 st->vj.vjs_searches = vj->sls_o_searches;
2450 st->vj.vjs_misses = vj->sls_o_misses;
2451 st->vj.vjs_errorin = vj->sls_i_error;
2452 st->vj.vjs_tossed = vj->sls_i_tossed;
2453 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2454 st->vj.vjs_compressedin = vj->sls_i_compressed;
2455 }
2456
2457 /*
2458 * Stuff for handling the lists of ppp units and channels
2459 * and for initialization.
2460 */
2461
2462 /*
2463 * Create a new ppp interface unit. Fails if it can't allocate memory
2464 * or if there is already a unit with the requested number.
2465 * unit == -1 means allocate a new number.
2466 */
2467 static struct ppp *
2468 ppp_create_interface(int unit, int *retp)
2469 {
2470 struct ppp *ppp;
2471 struct net_device *dev = NULL;
2472 int ret = -ENOMEM;
2473 int i;
2474
2475 ppp = kzalloc(sizeof(struct ppp), GFP_KERNEL);
2476 if (!ppp)
2477 goto out;
2478 dev = alloc_netdev(0, "", ppp_setup);
2479 if (!dev)
2480 goto out1;
2481
2482 ppp->mru = PPP_MRU;
2483 ppp->mru_alloc = PPP_MRU;
2484 init_ppp_file(&ppp->file, INTERFACE);
2485 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2486 for (i = 0; i < NUM_NP; ++i)
2487 ppp->npmode[i] = NPMODE_PASS;
2488 INIT_LIST_HEAD(&ppp->channels);
2489 spin_lock_init(&ppp->rlock);
2490 spin_lock_init(&ppp->wlock);
2491 #ifdef CONFIG_PPP_MULTILINK
2492 ppp->minseq = -1;
2493 skb_queue_head_init(&ppp->mrq);
2494 #endif /* CONFIG_PPP_MULTILINK */
2495 ppp->dev = dev;
2496 dev->priv = ppp;
2497
2498 dev->hard_start_xmit = ppp_start_xmit;
2499 dev->get_stats = ppp_net_stats;
2500 dev->do_ioctl = ppp_net_ioctl;
2501
2502 ret = -EEXIST;
2503 mutex_lock(&all_ppp_mutex);
2504 if (unit < 0)
2505 unit = cardmap_find_first_free(all_ppp_units);
2506 else if (cardmap_get(all_ppp_units, unit) != NULL)
2507 goto out2; /* unit already exists */
2508
2509 /* Initialize the new ppp unit */
2510 ppp->file.index = unit;
2511 sprintf(dev->name, "ppp%d", unit);
2512
2513 ret = register_netdev(dev);
2514 if (ret != 0) {
2515 printk(KERN_ERR "PPP: couldn't register device %s (%d)\n",
2516 dev->name, ret);
2517 goto out2;
2518 }
2519
2520 atomic_inc(&ppp_unit_count);
2521 ret = cardmap_set(&all_ppp_units, unit, ppp);
2522 if (ret != 0)
2523 goto out3;
2524
2525 mutex_unlock(&all_ppp_mutex);
2526 *retp = 0;
2527 return ppp;
2528
2529 out3:
2530 atomic_dec(&ppp_unit_count);
2531 out2:
2532 mutex_unlock(&all_ppp_mutex);
2533 free_netdev(dev);
2534 out1:
2535 kfree(ppp);
2536 out:
2537 *retp = ret;
2538 return NULL;
2539 }
2540
2541 /*
2542 * Initialize a ppp_file structure.
2543 */
2544 static void
2545 init_ppp_file(struct ppp_file *pf, int kind)
2546 {
2547 pf->kind = kind;
2548 skb_queue_head_init(&pf->xq);
2549 skb_queue_head_init(&pf->rq);
2550 atomic_set(&pf->refcnt, 1);
2551 init_waitqueue_head(&pf->rwait);
2552 }
2553
2554 /*
2555 * Take down a ppp interface unit - called when the owning file
2556 * (the one that created the unit) is closed or detached.
2557 */
2558 static void ppp_shutdown_interface(struct ppp *ppp)
2559 {
2560 struct net_device *dev;
2561
2562 mutex_lock(&all_ppp_mutex);
2563 ppp_lock(ppp);
2564 dev = ppp->dev;
2565 ppp->dev = NULL;
2566 ppp_unlock(ppp);
2567 /* This will call dev_close() for us. */
2568 if (dev) {
2569 unregister_netdev(dev);
2570 free_netdev(dev);
2571 }
2572 cardmap_set(&all_ppp_units, ppp->file.index, NULL);
2573 ppp->file.dead = 1;
2574 ppp->owner = NULL;
2575 wake_up_interruptible(&ppp->file.rwait);
2576 mutex_unlock(&all_ppp_mutex);
2577 }
2578
2579 /*
2580 * Free the memory used by a ppp unit. This is only called once
2581 * there are no channels connected to the unit and no file structs
2582 * that reference the unit.
2583 */
2584 static void ppp_destroy_interface(struct ppp *ppp)
2585 {
2586 atomic_dec(&ppp_unit_count);
2587
2588 if (!ppp->file.dead || ppp->n_channels) {
2589 /* "can't happen" */
2590 printk(KERN_ERR "ppp: destroying ppp struct %p but dead=%d "
2591 "n_channels=%d !\n", ppp, ppp->file.dead,
2592 ppp->n_channels);
2593 return;
2594 }
2595
2596 ppp_ccp_closed(ppp);
2597 if (ppp->vj) {
2598 slhc_free(ppp->vj);
2599 ppp->vj = NULL;
2600 }
2601 skb_queue_purge(&ppp->file.xq);
2602 skb_queue_purge(&ppp->file.rq);
2603 #ifdef CONFIG_PPP_MULTILINK
2604 skb_queue_purge(&ppp->mrq);
2605 #endif /* CONFIG_PPP_MULTILINK */
2606 #ifdef CONFIG_PPP_FILTER
2607 kfree(ppp->pass_filter);
2608 ppp->pass_filter = NULL;
2609 kfree(ppp->active_filter);
2610 ppp->active_filter = NULL;
2611 #endif /* CONFIG_PPP_FILTER */
2612
2613 if (ppp->xmit_pending)
2614 kfree_skb(ppp->xmit_pending);
2615
2616 kfree(ppp);
2617 }
2618
2619 /*
2620 * Locate an existing ppp unit.
2621 * The caller should have locked the all_ppp_mutex.
2622 */
2623 static struct ppp *
2624 ppp_find_unit(int unit)
2625 {
2626 return cardmap_get(all_ppp_units, unit);
2627 }
2628
2629 /*
2630 * Locate an existing ppp channel.
2631 * The caller should have locked the all_channels_lock.
2632 * First we look in the new_channels list, then in the
2633 * all_channels list. If found in the new_channels list,
2634 * we move it to the all_channels list. This is for speed
2635 * when we have a lot of channels in use.
2636 */
2637 static struct channel *
2638 ppp_find_channel(int unit)
2639 {
2640 struct channel *pch;
2641
2642 list_for_each_entry(pch, &new_channels, list) {
2643 if (pch->file.index == unit) {
2644 list_move(&pch->list, &all_channels);
2645 return pch;
2646 }
2647 }
2648 list_for_each_entry(pch, &all_channels, list) {
2649 if (pch->file.index == unit)
2650 return pch;
2651 }
2652 return NULL;
2653 }
2654
2655 /*
2656 * Connect a PPP channel to a PPP interface unit.
2657 */
2658 static int
2659 ppp_connect_channel(struct channel *pch, int unit)
2660 {
2661 struct ppp *ppp;
2662 int ret = -ENXIO;
2663 int hdrlen;
2664
2665 mutex_lock(&all_ppp_mutex);
2666 ppp = ppp_find_unit(unit);
2667 if (ppp == 0)
2668 goto out;
2669 write_lock_bh(&pch->upl);
2670 ret = -EINVAL;
2671 if (pch->ppp != 0)
2672 goto outl;
2673
2674 ppp_lock(ppp);
2675 if (pch->file.hdrlen > ppp->file.hdrlen)
2676 ppp->file.hdrlen = pch->file.hdrlen;
2677 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2678 if (ppp->dev && hdrlen > ppp->dev->hard_header_len)
2679 ppp->dev->hard_header_len = hdrlen;
2680 list_add_tail(&pch->clist, &ppp->channels);
2681 ++ppp->n_channels;
2682 pch->ppp = ppp;
2683 atomic_inc(&ppp->file.refcnt);
2684 ppp_unlock(ppp);
2685 ret = 0;
2686
2687 outl:
2688 write_unlock_bh(&pch->upl);
2689 out:
2690 mutex_unlock(&all_ppp_mutex);
2691 return ret;
2692 }
2693
2694 /*
2695 * Disconnect a channel from its ppp unit.
2696 */
2697 static int
2698 ppp_disconnect_channel(struct channel *pch)
2699 {
2700 struct ppp *ppp;
2701 int err = -EINVAL;
2702
2703 write_lock_bh(&pch->upl);
2704 ppp = pch->ppp;
2705 pch->ppp = NULL;
2706 write_unlock_bh(&pch->upl);
2707 if (ppp != 0) {
2708 /* remove it from the ppp unit's list */
2709 ppp_lock(ppp);
2710 list_del(&pch->clist);
2711 if (--ppp->n_channels == 0)
2712 wake_up_interruptible(&ppp->file.rwait);
2713 ppp_unlock(ppp);
2714 if (atomic_dec_and_test(&ppp->file.refcnt))
2715 ppp_destroy_interface(ppp);
2716 err = 0;
2717 }
2718 return err;
2719 }
2720
2721 /*
2722 * Free up the resources used by a ppp channel.
2723 */
2724 static void ppp_destroy_channel(struct channel *pch)
2725 {
2726 atomic_dec(&channel_count);
2727
2728 if (!pch->file.dead) {
2729 /* "can't happen" */
2730 printk(KERN_ERR "ppp: destroying undead channel %p !\n",
2731 pch);
2732 return;
2733 }
2734 skb_queue_purge(&pch->file.xq);
2735 skb_queue_purge(&pch->file.rq);
2736 kfree(pch);
2737 }
2738
2739 static void __exit ppp_cleanup(void)
2740 {
2741 /* should never happen */
2742 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2743 printk(KERN_ERR "PPP: removing module but units remain!\n");
2744 cardmap_destroy(&all_ppp_units);
2745 if (unregister_chrdev(PPP_MAJOR, "ppp") != 0)
2746 printk(KERN_ERR "PPP: failed to unregister PPP device\n");
2747 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
2748 class_destroy(ppp_class);
2749 }
2750
2751 /*
2752 * Cardmap implementation.
2753 */
2754 static void *cardmap_get(struct cardmap *map, unsigned int nr)
2755 {
2756 struct cardmap *p;
2757 int i;
2758
2759 for (p = map; p != NULL; ) {
2760 if ((i = nr >> p->shift) >= CARDMAP_WIDTH)
2761 return NULL;
2762 if (p->shift == 0)
2763 return p->ptr[i];
2764 nr &= ~(CARDMAP_MASK << p->shift);
2765 p = p->ptr[i];
2766 }
2767 return NULL;
2768 }
2769
2770 static int cardmap_set(struct cardmap **pmap, unsigned int nr, void *ptr)
2771 {
2772 struct cardmap *p;
2773 int i;
2774
2775 p = *pmap;
2776 if (p == NULL || (nr >> p->shift) >= CARDMAP_WIDTH) {
2777 do {
2778 /* need a new top level */
2779 struct cardmap *np = kzalloc(sizeof(*np), GFP_KERNEL);
2780 if (!np)
2781 goto enomem;
2782 np->ptr[0] = p;
2783 if (p != NULL) {
2784 np->shift = p->shift + CARDMAP_ORDER;
2785 p->parent = np;
2786 } else
2787 np->shift = 0;
2788 p = np;
2789 } while ((nr >> p->shift) >= CARDMAP_WIDTH);
2790 *pmap = p;
2791 }
2792 while (p->shift > 0) {
2793 i = (nr >> p->shift) & CARDMAP_MASK;
2794 if (p->ptr[i] == NULL) {
2795 struct cardmap *np = kzalloc(sizeof(*np), GFP_KERNEL);
2796 if (!np)
2797 goto enomem;
2798 np->shift = p->shift - CARDMAP_ORDER;
2799 np->parent = p;
2800 p->ptr[i] = np;
2801 }
2802 if (ptr == NULL)
2803 clear_bit(i, &p->inuse);
2804 p = p->ptr[i];
2805 }
2806 i = nr & CARDMAP_MASK;
2807 p->ptr[i] = ptr;
2808 if (ptr != NULL)
2809 set_bit(i, &p->inuse);
2810 else
2811 clear_bit(i, &p->inuse);
2812 return 0;
2813 enomem:
2814 return -ENOMEM;
2815 }
2816
2817 static unsigned int cardmap_find_first_free(struct cardmap *map)
2818 {
2819 struct cardmap *p;
2820 unsigned int nr = 0;
2821 int i;
2822
2823 if ((p = map) == NULL)
2824 return 0;
2825 for (;;) {
2826 i = find_first_zero_bit(&p->inuse, CARDMAP_WIDTH);
2827 if (i >= CARDMAP_WIDTH) {
2828 if (p->parent == NULL)
2829 return CARDMAP_WIDTH << p->shift;
2830 p = p->parent;
2831 i = (nr >> p->shift) & CARDMAP_MASK;
2832 set_bit(i, &p->inuse);
2833 continue;
2834 }
2835 nr = (nr & (~CARDMAP_MASK << p->shift)) | (i << p->shift);
2836 if (p->shift == 0 || p->ptr[i] == NULL)
2837 return nr;
2838 p = p->ptr[i];
2839 }
2840 }
2841
2842 static void cardmap_destroy(struct cardmap **pmap)
2843 {
2844 struct cardmap *p, *np;
2845 int i;
2846
2847 for (p = *pmap; p != NULL; p = np) {
2848 if (p->shift != 0) {
2849 for (i = 0; i < CARDMAP_WIDTH; ++i)
2850 if (p->ptr[i] != NULL)
2851 break;
2852 if (i < CARDMAP_WIDTH) {
2853 np = p->ptr[i];
2854 p->ptr[i] = NULL;
2855 continue;
2856 }
2857 }
2858 np = p->parent;
2859 kfree(p);
2860 }
2861 *pmap = NULL;
2862 }
2863
2864 /* Module/initialization stuff */
2865
2866 module_init(ppp_init);
2867 module_exit(ppp_cleanup);
2868
2869 EXPORT_SYMBOL(ppp_register_channel);
2870 EXPORT_SYMBOL(ppp_unregister_channel);
2871 EXPORT_SYMBOL(ppp_channel_index);
2872 EXPORT_SYMBOL(ppp_unit_number);
2873 EXPORT_SYMBOL(ppp_input);
2874 EXPORT_SYMBOL(ppp_input_error);
2875 EXPORT_SYMBOL(ppp_output_wakeup);
2876 EXPORT_SYMBOL(ppp_register_compressor);
2877 EXPORT_SYMBOL(ppp_unregister_compressor);
2878 MODULE_LICENSE("GPL");
2879 MODULE_ALIAS_CHARDEV_MAJOR(PPP_MAJOR);
2880 MODULE_ALIAS("/dev/ppp");
Tomato firmware and modifications.