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ppp: unset IFF_XMIT_DST_RELEASE in ppp_setup()
[linux-2.6/mini2440.git] / drivers / net / ppp_generic.c
blob639d11bc444e8a07a88c50beaddf9f867f126aee
1 /*
2 * Generic PPP layer for Linux.
3 *
4 * Copyright 1999-2002 Paul Mackerras.
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 *
11 * The generic PPP layer handles the PPP network interfaces, the
12 * /dev/ppp device, packet and VJ compression, and multilink.
13 * It talks to PPP `channels' via the interface defined in
14 * include/linux/ppp_channel.h. Channels provide the basic means for
15 * sending and receiving PPP frames on some kind of communications
16 * channel.
17 *
18 * Part of the code in this driver was inspired by the old async-only
19 * PPP driver, written by Michael Callahan and Al Longyear, and
20 * subsequently hacked by Paul Mackerras.
21 *
22 * ==FILEVERSION 20041108==
23 */
24
25 #include <linux/module.h>
26 #include <linux/kernel.h>
27 #include <linux/kmod.h>
28 #include <linux/init.h>
29 #include <linux/list.h>
30 #include <linux/idr.h>
31 #include <linux/netdevice.h>
32 #include <linux/poll.h>
33 #include <linux/ppp_defs.h>
34 #include <linux/filter.h>
35 #include <linux/if_ppp.h>
36 #include <linux/ppp_channel.h>
37 #include <linux/ppp-comp.h>
38 #include <linux/skbuff.h>
39 #include <linux/rtnetlink.h>
40 #include <linux/if_arp.h>
41 #include <linux/ip.h>
42 #include <linux/tcp.h>
43 #include <linux/smp_lock.h>
44 #include <linux/spinlock.h>
45 #include <linux/rwsem.h>
46 #include <linux/stddef.h>
47 #include <linux/device.h>
48 #include <linux/mutex.h>
49 #include <net/slhc_vj.h>
50 #include <asm/atomic.h>
51
52 #include <linux/nsproxy.h>
53 #include <net/net_namespace.h>
54 #include <net/netns/generic.h>
55
56 #define PPP_VERSION "2.4.2"
57
58 /*
59 * Network protocols we support.
60 */
61 #define NP_IP 0 /* Internet Protocol V4 */
62 #define NP_IPV6 1 /* Internet Protocol V6 */
63 #define NP_IPX 2 /* IPX protocol */
64 #define NP_AT 3 /* Appletalk protocol */
65 #define NP_MPLS_UC 4 /* MPLS unicast */
66 #define NP_MPLS_MC 5 /* MPLS multicast */
67 #define NUM_NP 6 /* Number of NPs. */
68
69 #define MPHDRLEN 6 /* multilink protocol header length */
70 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */
71 #define MIN_FRAG_SIZE 64
72
73 /*
74 * An instance of /dev/ppp can be associated with either a ppp
75 * interface unit or a ppp channel. In both cases, file->private_data
76 * points to one of these.
77 */
78 struct ppp_file {
79 enum {
80 INTERFACE=1, CHANNEL
81 } kind;
82 struct sk_buff_head xq; /* pppd transmit queue */
83 struct sk_buff_head rq; /* receive queue for pppd */
84 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */
85 atomic_t refcnt; /* # refs (incl /dev/ppp attached) */
86 int hdrlen; /* space to leave for headers */
87 int index; /* interface unit / channel number */
88 int dead; /* unit/channel has been shut down */
89 };
90
91 #define PF_TO_X(pf, X) container_of(pf, X, file)
92
93 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
94 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
95
96 /*
97 * Data structure describing one ppp unit.
98 * A ppp unit corresponds to a ppp network interface device
99 * and represents a multilink bundle.
100 * It can have 0 or more ppp channels connected to it.
101 */
102 struct ppp {
103 struct ppp_file file; /* stuff for read/write/poll 0 */
104 struct file *owner; /* file that owns this unit 48 */
105 struct list_head channels; /* list of attached channels 4c */
106 int n_channels; /* how many channels are attached 54 */
107 spinlock_t rlock; /* lock for receive side 58 */
108 spinlock_t wlock; /* lock for transmit side 5c */
109 int mru; /* max receive unit 60 */
110 unsigned int flags; /* control bits 64 */
111 unsigned int xstate; /* transmit state bits 68 */
112 unsigned int rstate; /* receive state bits 6c */
113 int debug; /* debug flags 70 */
114 struct slcompress *vj; /* state for VJ header compression */
115 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
116 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
117 struct compressor *xcomp; /* transmit packet compressor 8c */
118 void *xc_state; /* its internal state 90 */
119 struct compressor *rcomp; /* receive decompressor 94 */
120 void *rc_state; /* its internal state 98 */
121 unsigned long last_xmit; /* jiffies when last pkt sent 9c */
122 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
123 struct net_device *dev; /* network interface device a4 */
124 int closing; /* is device closing down? a8 */
125 #ifdef CONFIG_PPP_MULTILINK
126 int nxchan; /* next channel to send something on */
127 u32 nxseq; /* next sequence number to send */
128 int mrru; /* MP: max reconst. receive unit */
129 u32 nextseq; /* MP: seq no of next packet */
130 u32 minseq; /* MP: min of most recent seqnos */
131 struct sk_buff_head mrq; /* MP: receive reconstruction queue */
132 #endif /* CONFIG_PPP_MULTILINK */
133 #ifdef CONFIG_PPP_FILTER
134 struct sock_filter *pass_filter; /* filter for packets to pass */
135 struct sock_filter *active_filter;/* filter for pkts to reset idle */
136 unsigned pass_len, active_len;
137 #endif /* CONFIG_PPP_FILTER */
138 struct net *ppp_net; /* the net we belong to */
139 };
140
141 /*
142 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
143 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
144 * SC_MUST_COMP
145 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
146 * Bits in xstate: SC_COMP_RUN
147 */
148 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
149 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
150 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
151
152 /*
153 * Private data structure for each channel.
154 * This includes the data structure used for multilink.
155 */
156 struct channel {
157 struct ppp_file file; /* stuff for read/write/poll */
158 struct list_head list; /* link in all/new_channels list */
159 struct ppp_channel *chan; /* public channel data structure */
160 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
161 spinlock_t downl; /* protects `chan', file.xq dequeue */
162 struct ppp *ppp; /* ppp unit we're connected to */
163 struct net *chan_net; /* the net channel belongs to */
164 struct list_head clist; /* link in list of channels per unit */
165 rwlock_t upl; /* protects `ppp' */
166 #ifdef CONFIG_PPP_MULTILINK
167 u8 avail; /* flag used in multilink stuff */
168 u8 had_frag; /* >= 1 fragments have been sent */
169 u32 lastseq; /* MP: last sequence # received */
170 int speed; /* speed of the corresponding ppp channel*/
171 #endif /* CONFIG_PPP_MULTILINK */
172 };
173
174 /*
175 * SMP locking issues:
176 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
177 * list and the ppp.n_channels field, you need to take both locks
178 * before you modify them.
179 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
180 * channel.downl.
181 */
182
183 static atomic_t ppp_unit_count = ATOMIC_INIT(0);
184 static atomic_t channel_count = ATOMIC_INIT(0);
185
186 /* per-net private data for this module */
187 static int ppp_net_id;
188 struct ppp_net {
189 /* units to ppp mapping */
190 struct idr units_idr;
191
192 /*
193 * all_ppp_mutex protects the units_idr mapping.
194 * It also ensures that finding a ppp unit in the units_idr
195 * map and updating its file.refcnt field is atomic.
196 */
197 struct mutex all_ppp_mutex;
198
199 /* channels */
200 struct list_head all_channels;
201 struct list_head new_channels;
202 int last_channel_index;
203
204 /*
205 * all_channels_lock protects all_channels and
206 * last_channel_index, and the atomicity of find
207 * a channel and updating its file.refcnt field.
208 */
209 spinlock_t all_channels_lock;
210 };
211
212 /* Get the PPP protocol number from a skb */
213 #define PPP_PROTO(skb) (((skb)->data[0] << 8) + (skb)->data[1])
214
215 /* We limit the length of ppp->file.rq to this (arbitrary) value */
216 #define PPP_MAX_RQLEN 32
217
218 /*
219 * Maximum number of multilink fragments queued up.
220 * This has to be large enough to cope with the maximum latency of
221 * the slowest channel relative to the others. Strictly it should
222 * depend on the number of channels and their characteristics.
223 */
224 #define PPP_MP_MAX_QLEN 128
225
226 /* Multilink header bits. */
227 #define B 0x80 /* this fragment begins a packet */
228 #define E 0x40 /* this fragment ends a packet */
229
230 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */
231 #define seq_before(a, b) ((s32)((a) - (b)) < 0)
232 #define seq_after(a, b) ((s32)((a) - (b)) > 0)
233
234 /* Prototypes. */
235 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
236 struct file *file, unsigned int cmd, unsigned long arg);
237 static void ppp_xmit_process(struct ppp *ppp);
238 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
239 static void ppp_push(struct ppp *ppp);
240 static void ppp_channel_push(struct channel *pch);
241 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
242 struct channel *pch);
243 static void ppp_receive_error(struct ppp *ppp);
244 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
245 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
246 struct sk_buff *skb);
247 #ifdef CONFIG_PPP_MULTILINK
248 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
249 struct channel *pch);
250 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
251 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
252 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
253 #endif /* CONFIG_PPP_MULTILINK */
254 static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
255 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
256 static void ppp_ccp_closed(struct ppp *ppp);
257 static struct compressor *find_compressor(int type);
258 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
259 static struct ppp *ppp_create_interface(struct net *net, int unit, int *retp);
260 static void init_ppp_file(struct ppp_file *pf, int kind);
261 static void ppp_shutdown_interface(struct ppp *ppp);
262 static void ppp_destroy_interface(struct ppp *ppp);
263 static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit);
264 static struct channel *ppp_find_channel(struct ppp_net *pn, int unit);
265 static int ppp_connect_channel(struct channel *pch, int unit);
266 static int ppp_disconnect_channel(struct channel *pch);
267 static void ppp_destroy_channel(struct channel *pch);
268 static int unit_get(struct idr *p, void *ptr);
269 static int unit_set(struct idr *p, void *ptr, int n);
270 static void unit_put(struct idr *p, int n);
271 static void *unit_find(struct idr *p, int n);
272
273 static struct class *ppp_class;
274
275 /* per net-namespace data */
276 static inline struct ppp_net *ppp_pernet(struct net *net)
277 {
278 BUG_ON(!net);
279
280 return net_generic(net, ppp_net_id);
281 }
282
283 /* Translates a PPP protocol number to a NP index (NP == network protocol) */
284 static inline int proto_to_npindex(int proto)
285 {
286 switch (proto) {
287 case PPP_IP:
288 return NP_IP;
289 case PPP_IPV6:
290 return NP_IPV6;
291 case PPP_IPX:
292 return NP_IPX;
293 case PPP_AT:
294 return NP_AT;
295 case PPP_MPLS_UC:
296 return NP_MPLS_UC;
297 case PPP_MPLS_MC:
298 return NP_MPLS_MC;
299 }
300 return -EINVAL;
301 }
302
303 /* Translates an NP index into a PPP protocol number */
304 static const int npindex_to_proto[NUM_NP] = {
305 PPP_IP,
306 PPP_IPV6,
307 PPP_IPX,
308 PPP_AT,
309 PPP_MPLS_UC,
310 PPP_MPLS_MC,
311 };
312
313 /* Translates an ethertype into an NP index */
314 static inline int ethertype_to_npindex(int ethertype)
315 {
316 switch (ethertype) {
317 case ETH_P_IP:
318 return NP_IP;
319 case ETH_P_IPV6:
320 return NP_IPV6;
321 case ETH_P_IPX:
322 return NP_IPX;
323 case ETH_P_PPPTALK:
324 case ETH_P_ATALK:
325 return NP_AT;
326 case ETH_P_MPLS_UC:
327 return NP_MPLS_UC;
328 case ETH_P_MPLS_MC:
329 return NP_MPLS_MC;
330 }
331 return -1;
332 }
333
334 /* Translates an NP index into an ethertype */
335 static const int npindex_to_ethertype[NUM_NP] = {
336 ETH_P_IP,
337 ETH_P_IPV6,
338 ETH_P_IPX,
339 ETH_P_PPPTALK,
340 ETH_P_MPLS_UC,
341 ETH_P_MPLS_MC,
342 };
343
344 /*
345 * Locking shorthand.
346 */
347 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
348 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
349 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
350 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
351 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
352 ppp_recv_lock(ppp); } while (0)
353 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
354 ppp_xmit_unlock(ppp); } while (0)
355
356 /*
357 * /dev/ppp device routines.
358 * The /dev/ppp device is used by pppd to control the ppp unit.
359 * It supports the read, write, ioctl and poll functions.
360 * Open instances of /dev/ppp can be in one of three states:
361 * unattached, attached to a ppp unit, or attached to a ppp channel.
362 */
363 static int ppp_open(struct inode *inode, struct file *file)
364 {
365 cycle_kernel_lock();
366 /*
367 * This could (should?) be enforced by the permissions on /dev/ppp.
368 */
369 if (!capable(CAP_NET_ADMIN))
370 return -EPERM;
371 return 0;
372 }
373
374 static int ppp_release(struct inode *unused, struct file *file)
375 {
376 struct ppp_file *pf = file->private_data;
377 struct ppp *ppp;
378
379 if (pf) {
380 file->private_data = NULL;
381 if (pf->kind == INTERFACE) {
382 ppp = PF_TO_PPP(pf);
383 if (file == ppp->owner)
384 ppp_shutdown_interface(ppp);
385 }
386 if (atomic_dec_and_test(&pf->refcnt)) {
387 switch (pf->kind) {
388 case INTERFACE:
389 ppp_destroy_interface(PF_TO_PPP(pf));
390 break;
391 case CHANNEL:
392 ppp_destroy_channel(PF_TO_CHANNEL(pf));
393 break;
394 }
395 }
396 }
397 return 0;
398 }
399
400 static ssize_t ppp_read(struct file *file, char __user *buf,
401 size_t count, loff_t *ppos)
402 {
403 struct ppp_file *pf = file->private_data;
404 DECLARE_WAITQUEUE(wait, current);
405 ssize_t ret;
406 struct sk_buff *skb = NULL;
407
408 ret = count;
409
410 if (!pf)
411 return -ENXIO;
412 add_wait_queue(&pf->rwait, &wait);
413 for (;;) {
414 set_current_state(TASK_INTERRUPTIBLE);
415 skb = skb_dequeue(&pf->rq);
416 if (skb)
417 break;
418 ret = 0;
419 if (pf->dead)
420 break;
421 if (pf->kind == INTERFACE) {
422 /*
423 * Return 0 (EOF) on an interface that has no
424 * channels connected, unless it is looping
425 * network traffic (demand mode).
426 */
427 struct ppp *ppp = PF_TO_PPP(pf);
428 if (ppp->n_channels == 0
429 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
430 break;
431 }
432 ret = -EAGAIN;
433 if (file->f_flags & O_NONBLOCK)
434 break;
435 ret = -ERESTARTSYS;
436 if (signal_pending(current))
437 break;
438 schedule();
439 }
440 set_current_state(TASK_RUNNING);
441 remove_wait_queue(&pf->rwait, &wait);
442
443 if (!skb)
444 goto out;
445
446 ret = -EOVERFLOW;
447 if (skb->len > count)
448 goto outf;
449 ret = -EFAULT;
450 if (copy_to_user(buf, skb->data, skb->len))
451 goto outf;
452 ret = skb->len;
453
454 outf:
455 kfree_skb(skb);
456 out:
457 return ret;
458 }
459
460 static ssize_t ppp_write(struct file *file, const char __user *buf,
461 size_t count, loff_t *ppos)
462 {
463 struct ppp_file *pf = file->private_data;
464 struct sk_buff *skb;
465 ssize_t ret;
466
467 if (!pf)
468 return -ENXIO;
469 ret = -ENOMEM;
470 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
471 if (!skb)
472 goto out;
473 skb_reserve(skb, pf->hdrlen);
474 ret = -EFAULT;
475 if (copy_from_user(skb_put(skb, count), buf, count)) {
476 kfree_skb(skb);
477 goto out;
478 }
479
480 skb_queue_tail(&pf->xq, skb);
481
482 switch (pf->kind) {
483 case INTERFACE:
484 ppp_xmit_process(PF_TO_PPP(pf));
485 break;
486 case CHANNEL:
487 ppp_channel_push(PF_TO_CHANNEL(pf));
488 break;
489 }
490
491 ret = count;
492
493 out:
494 return ret;
495 }
496
497 /* No kernel lock - fine */
498 static unsigned int ppp_poll(struct file *file, poll_table *wait)
499 {
500 struct ppp_file *pf = file->private_data;
501 unsigned int mask;
502
503 if (!pf)
504 return 0;
505 poll_wait(file, &pf->rwait, wait);
506 mask = POLLOUT | POLLWRNORM;
507 if (skb_peek(&pf->rq))
508 mask |= POLLIN | POLLRDNORM;
509 if (pf->dead)
510 mask |= POLLHUP;
511 else if (pf->kind == INTERFACE) {
512 /* see comment in ppp_read */
513 struct ppp *ppp = PF_TO_PPP(pf);
514 if (ppp->n_channels == 0
515 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
516 mask |= POLLIN | POLLRDNORM;
517 }
518
519 return mask;
520 }
521
522 #ifdef CONFIG_PPP_FILTER
523 static int get_filter(void __user *arg, struct sock_filter **p)
524 {
525 struct sock_fprog uprog;
526 struct sock_filter *code = NULL;
527 int len, err;
528
529 if (copy_from_user(&uprog, arg, sizeof(uprog)))
530 return -EFAULT;
531
532 if (!uprog.len) {
533 *p = NULL;
534 return 0;
535 }
536
537 len = uprog.len * sizeof(struct sock_filter);
538 code = kmalloc(len, GFP_KERNEL);
539 if (code == NULL)
540 return -ENOMEM;
541
542 if (copy_from_user(code, uprog.filter, len)) {
543 kfree(code);
544 return -EFAULT;
545 }
546
547 err = sk_chk_filter(code, uprog.len);
548 if (err) {
549 kfree(code);
550 return err;
551 }
552
553 *p = code;
554 return uprog.len;
555 }
556 #endif /* CONFIG_PPP_FILTER */
557
558 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
559 {
560 struct ppp_file *pf = file->private_data;
561 struct ppp *ppp;
562 int err = -EFAULT, val, val2, i;
563 struct ppp_idle idle;
564 struct npioctl npi;
565 int unit, cflags;
566 struct slcompress *vj;
567 void __user *argp = (void __user *)arg;
568 int __user *p = argp;
569
570 if (!pf)
571 return ppp_unattached_ioctl(current->nsproxy->net_ns,
572 pf, file, cmd, arg);
573
574 if (cmd == PPPIOCDETACH) {
575 /*
576 * We have to be careful here... if the file descriptor
577 * has been dup'd, we could have another process in the
578 * middle of a poll using the same file *, so we had
579 * better not free the interface data structures -
580 * instead we fail the ioctl. Even in this case, we
581 * shut down the interface if we are the owner of it.
582 * Actually, we should get rid of PPPIOCDETACH, userland
583 * (i.e. pppd) could achieve the same effect by closing
584 * this fd and reopening /dev/ppp.
585 */
586 err = -EINVAL;
587 lock_kernel();
588 if (pf->kind == INTERFACE) {
589 ppp = PF_TO_PPP(pf);
590 if (file == ppp->owner)
591 ppp_shutdown_interface(ppp);
592 }
593 if (atomic_long_read(&file->f_count) <= 2) {
594 ppp_release(NULL, file);
595 err = 0;
596 } else
597 printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%ld\n",
598 atomic_long_read(&file->f_count));
599 unlock_kernel();
600 return err;
601 }
602
603 if (pf->kind == CHANNEL) {
604 struct channel *pch;
605 struct ppp_channel *chan;
606
607 lock_kernel();
608 pch = PF_TO_CHANNEL(pf);
609
610 switch (cmd) {
611 case PPPIOCCONNECT:
612 if (get_user(unit, p))
613 break;
614 err = ppp_connect_channel(pch, unit);
615 break;
616
617 case PPPIOCDISCONN:
618 err = ppp_disconnect_channel(pch);
619 break;
620
621 default:
622 down_read(&pch->chan_sem);
623 chan = pch->chan;
624 err = -ENOTTY;
625 if (chan && chan->ops->ioctl)
626 err = chan->ops->ioctl(chan, cmd, arg);
627 up_read(&pch->chan_sem);
628 }
629 unlock_kernel();
630 return err;
631 }
632
633 if (pf->kind != INTERFACE) {
634 /* can't happen */
635 printk(KERN_ERR "PPP: not interface or channel??\n");
636 return -EINVAL;
637 }
638
639 lock_kernel();
640 ppp = PF_TO_PPP(pf);
641 switch (cmd) {
642 case PPPIOCSMRU:
643 if (get_user(val, p))
644 break;
645 ppp->mru = val;
646 err = 0;
647 break;
648
649 case PPPIOCSFLAGS:
650 if (get_user(val, p))
651 break;
652 ppp_lock(ppp);
653 cflags = ppp->flags & ~val;
654 ppp->flags = val & SC_FLAG_BITS;
655 ppp_unlock(ppp);
656 if (cflags & SC_CCP_OPEN)
657 ppp_ccp_closed(ppp);
658 err = 0;
659 break;
660
661 case PPPIOCGFLAGS:
662 val = ppp->flags | ppp->xstate | ppp->rstate;
663 if (put_user(val, p))
664 break;
665 err = 0;
666 break;
667
668 case PPPIOCSCOMPRESS:
669 err = ppp_set_compress(ppp, arg);
670 break;
671
672 case PPPIOCGUNIT:
673 if (put_user(ppp->file.index, p))
674 break;
675 err = 0;
676 break;
677
678 case PPPIOCSDEBUG:
679 if (get_user(val, p))
680 break;
681 ppp->debug = val;
682 err = 0;
683 break;
684
685 case PPPIOCGDEBUG:
686 if (put_user(ppp->debug, p))
687 break;
688 err = 0;
689 break;
690
691 case PPPIOCGIDLE:
692 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
693 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
694 if (copy_to_user(argp, &idle, sizeof(idle)))
695 break;
696 err = 0;
697 break;
698
699 case PPPIOCSMAXCID:
700 if (get_user(val, p))
701 break;
702 val2 = 15;
703 if ((val >> 16) != 0) {
704 val2 = val >> 16;
705 val &= 0xffff;
706 }
707 vj = slhc_init(val2+1, val+1);
708 if (!vj) {
709 printk(KERN_ERR "PPP: no memory (VJ compressor)\n");
710 err = -ENOMEM;
711 break;
712 }
713 ppp_lock(ppp);
714 if (ppp->vj)
715 slhc_free(ppp->vj);
716 ppp->vj = vj;
717 ppp_unlock(ppp);
718 err = 0;
719 break;
720
721 case PPPIOCGNPMODE:
722 case PPPIOCSNPMODE:
723 if (copy_from_user(&npi, argp, sizeof(npi)))
724 break;
725 err = proto_to_npindex(npi.protocol);
726 if (err < 0)
727 break;
728 i = err;
729 if (cmd == PPPIOCGNPMODE) {
730 err = -EFAULT;
731 npi.mode = ppp->npmode[i];
732 if (copy_to_user(argp, &npi, sizeof(npi)))
733 break;
734 } else {
735 ppp->npmode[i] = npi.mode;
736 /* we may be able to transmit more packets now (??) */
737 netif_wake_queue(ppp->dev);
738 }
739 err = 0;
740 break;
741
742 #ifdef CONFIG_PPP_FILTER
743 case PPPIOCSPASS:
744 {
745 struct sock_filter *code;
746 err = get_filter(argp, &code);
747 if (err >= 0) {
748 ppp_lock(ppp);
749 kfree(ppp->pass_filter);
750 ppp->pass_filter = code;
751 ppp->pass_len = err;
752 ppp_unlock(ppp);
753 err = 0;
754 }
755 break;
756 }
757 case PPPIOCSACTIVE:
758 {
759 struct sock_filter *code;
760 err = get_filter(argp, &code);
761 if (err >= 0) {
762 ppp_lock(ppp);
763 kfree(ppp->active_filter);
764 ppp->active_filter = code;
765 ppp->active_len = err;
766 ppp_unlock(ppp);
767 err = 0;
768 }
769 break;
770 }
771 #endif /* CONFIG_PPP_FILTER */
772
773 #ifdef CONFIG_PPP_MULTILINK
774 case PPPIOCSMRRU:
775 if (get_user(val, p))
776 break;
777 ppp_recv_lock(ppp);
778 ppp->mrru = val;
779 ppp_recv_unlock(ppp);
780 err = 0;
781 break;
782 #endif /* CONFIG_PPP_MULTILINK */
783
784 default:
785 err = -ENOTTY;
786 }
787 unlock_kernel();
788 return err;
789 }
790
791 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
792 struct file *file, unsigned int cmd, unsigned long arg)
793 {
794 int unit, err = -EFAULT;
795 struct ppp *ppp;
796 struct channel *chan;
797 struct ppp_net *pn;
798 int __user *p = (int __user *)arg;
799
800 lock_kernel();
801 switch (cmd) {
802 case PPPIOCNEWUNIT:
803 /* Create a new ppp unit */
804 if (get_user(unit, p))
805 break;
806 ppp = ppp_create_interface(net, unit, &err);
807 if (!ppp)
808 break;
809 file->private_data = &ppp->file;
810 ppp->owner = file;
811 err = -EFAULT;
812 if (put_user(ppp->file.index, p))
813 break;
814 err = 0;
815 break;
816
817 case PPPIOCATTACH:
818 /* Attach to an existing ppp unit */
819 if (get_user(unit, p))
820 break;
821 err = -ENXIO;
822 pn = ppp_pernet(net);
823 mutex_lock(&pn->all_ppp_mutex);
824 ppp = ppp_find_unit(pn, unit);
825 if (ppp) {
826 atomic_inc(&ppp->file.refcnt);
827 file->private_data = &ppp->file;
828 err = 0;
829 }
830 mutex_unlock(&pn->all_ppp_mutex);
831 break;
832
833 case PPPIOCATTCHAN:
834 if (get_user(unit, p))
835 break;
836 err = -ENXIO;
837 pn = ppp_pernet(net);
838 spin_lock_bh(&pn->all_channels_lock);
839 chan = ppp_find_channel(pn, unit);
840 if (chan) {
841 atomic_inc(&chan->file.refcnt);
842 file->private_data = &chan->file;
843 err = 0;
844 }
845 spin_unlock_bh(&pn->all_channels_lock);
846 break;
847
848 default:
849 err = -ENOTTY;
850 }
851 unlock_kernel();
852 return err;
853 }
854
855 static const struct file_operations ppp_device_fops = {
856 .owner = THIS_MODULE,
857 .read = ppp_read,
858 .write = ppp_write,
859 .poll = ppp_poll,
860 .unlocked_ioctl = ppp_ioctl,
861 .open = ppp_open,
862 .release = ppp_release
863 };
864
865 static __net_init int ppp_init_net(struct net *net)
866 {
867 struct ppp_net *pn;
868 int err;
869
870 pn = kzalloc(sizeof(*pn), GFP_KERNEL);
871 if (!pn)
872 return -ENOMEM;
873
874 idr_init(&pn->units_idr);
875 mutex_init(&pn->all_ppp_mutex);
876
877 INIT_LIST_HEAD(&pn->all_channels);
878 INIT_LIST_HEAD(&pn->new_channels);
879
880 spin_lock_init(&pn->all_channels_lock);
881
882 err = net_assign_generic(net, ppp_net_id, pn);
883 if (err) {
884 kfree(pn);
885 return err;
886 }
887
888 return 0;
889 }
890
891 static __net_exit void ppp_exit_net(struct net *net)
892 {
893 struct ppp_net *pn;
894
895 pn = net_generic(net, ppp_net_id);
896 idr_destroy(&pn->units_idr);
897 /*
898 * if someone has cached our net then
899 * further net_generic call will return NULL
900 */
901 net_assign_generic(net, ppp_net_id, NULL);
902 kfree(pn);
903 }
904
905 static struct pernet_operations ppp_net_ops = {
906 .init = ppp_init_net,
907 .exit = ppp_exit_net,
908 };
909
910 #define PPP_MAJOR 108
911
912 /* Called at boot time if ppp is compiled into the kernel,
913 or at module load time (from init_module) if compiled as a module. */
914 static int __init ppp_init(void)
915 {
916 int err;
917
918 printk(KERN_INFO "PPP generic driver version " PPP_VERSION "\n");
919
920 err = register_pernet_gen_device(&ppp_net_id, &ppp_net_ops);
921 if (err) {
922 printk(KERN_ERR "failed to register PPP pernet device (%d)\n", err);
923 goto out;
924 }
925
926 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
927 if (err) {
928 printk(KERN_ERR "failed to register PPP device (%d)\n", err);
929 goto out_net;
930 }
931
932 ppp_class = class_create(THIS_MODULE, "ppp");
933 if (IS_ERR(ppp_class)) {
934 err = PTR_ERR(ppp_class);
935 goto out_chrdev;
936 }
937
938 /* not a big deal if we fail here :-) */
939 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
940
941 return 0;
942
943 out_chrdev:
944 unregister_chrdev(PPP_MAJOR, "ppp");
945 out_net:
946 unregister_pernet_gen_device(ppp_net_id, &ppp_net_ops);
947 out:
948 return err;
949 }
950
951 /*
952 * Network interface unit routines.
953 */
954 static int
955 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
956 {
957 struct ppp *ppp = netdev_priv(dev);
958 int npi, proto;
959 unsigned char *pp;
960
961 npi = ethertype_to_npindex(ntohs(skb->protocol));
962 if (npi < 0)
963 goto outf;
964
965 /* Drop, accept or reject the packet */
966 switch (ppp->npmode[npi]) {
967 case NPMODE_PASS:
968 break;
969 case NPMODE_QUEUE:
970 /* it would be nice to have a way to tell the network
971 system to queue this one up for later. */
972 goto outf;
973 case NPMODE_DROP:
974 case NPMODE_ERROR:
975 goto outf;
976 }
977
978 /* Put the 2-byte PPP protocol number on the front,
979 making sure there is room for the address and control fields. */
980 if (skb_cow_head(skb, PPP_HDRLEN))
981 goto outf;
982
983 pp = skb_push(skb, 2);
984 proto = npindex_to_proto[npi];
985 pp[0] = proto >> 8;
986 pp[1] = proto;
987
988 netif_stop_queue(dev);
989 skb_queue_tail(&ppp->file.xq, skb);
990 ppp_xmit_process(ppp);
991 return 0;
992
993 outf:
994 kfree_skb(skb);
995 ++dev->stats.tx_dropped;
996 return 0;
997 }
998
999 static int
1000 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1001 {
1002 struct ppp *ppp = netdev_priv(dev);
1003 int err = -EFAULT;
1004 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
1005 struct ppp_stats stats;
1006 struct ppp_comp_stats cstats;
1007 char *vers;
1008
1009 switch (cmd) {
1010 case SIOCGPPPSTATS:
1011 ppp_get_stats(ppp, &stats);
1012 if (copy_to_user(addr, &stats, sizeof(stats)))
1013 break;
1014 err = 0;
1015 break;
1016
1017 case SIOCGPPPCSTATS:
1018 memset(&cstats, 0, sizeof(cstats));
1019 if (ppp->xc_state)
1020 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
1021 if (ppp->rc_state)
1022 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
1023 if (copy_to_user(addr, &cstats, sizeof(cstats)))
1024 break;
1025 err = 0;
1026 break;
1027
1028 case SIOCGPPPVER:
1029 vers = PPP_VERSION;
1030 if (copy_to_user(addr, vers, strlen(vers) + 1))
1031 break;
1032 err = 0;
1033 break;
1034
1035 default:
1036 err = -EINVAL;
1037 }
1038
1039 return err;
1040 }
1041
1042 static const struct net_device_ops ppp_netdev_ops = {
1043 .ndo_start_xmit = ppp_start_xmit,
1044 .ndo_do_ioctl = ppp_net_ioctl,
1045 };
1046
1047 static void ppp_setup(struct net_device *dev)
1048 {
1049 dev->netdev_ops = &ppp_netdev_ops;
1050 dev->hard_header_len = PPP_HDRLEN;
1051 dev->mtu = PPP_MTU;
1052 dev->addr_len = 0;
1053 dev->tx_queue_len = 3;
1054 dev->type = ARPHRD_PPP;
1055 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1056 dev->features |= NETIF_F_NETNS_LOCAL;
1057 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1058 }
1059
1060 /*
1061 * Transmit-side routines.
1062 */
1063
1064 /*
1065 * Called to do any work queued up on the transmit side
1066 * that can now be done.
1067 */
1068 static void
1069 ppp_xmit_process(struct ppp *ppp)
1070 {
1071 struct sk_buff *skb;
1072
1073 ppp_xmit_lock(ppp);
1074 if (!ppp->closing) {
1075 ppp_push(ppp);
1076 while (!ppp->xmit_pending
1077 && (skb = skb_dequeue(&ppp->file.xq)))
1078 ppp_send_frame(ppp, skb);
1079 /* If there's no work left to do, tell the core net
1080 code that we can accept some more. */
1081 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1082 netif_wake_queue(ppp->dev);
1083 }
1084 ppp_xmit_unlock(ppp);
1085 }
1086
1087 static inline struct sk_buff *
1088 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1089 {
1090 struct sk_buff *new_skb;
1091 int len;
1092 int new_skb_size = ppp->dev->mtu +
1093 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1094 int compressor_skb_size = ppp->dev->mtu +
1095 ppp->xcomp->comp_extra + PPP_HDRLEN;
1096 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1097 if (!new_skb) {
1098 if (net_ratelimit())
1099 printk(KERN_ERR "PPP: no memory (comp pkt)\n");
1100 return NULL;
1101 }
1102 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1103 skb_reserve(new_skb,
1104 ppp->dev->hard_header_len - PPP_HDRLEN);
1105
1106 /* compressor still expects A/C bytes in hdr */
1107 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1108 new_skb->data, skb->len + 2,
1109 compressor_skb_size);
1110 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1111 kfree_skb(skb);
1112 skb = new_skb;
1113 skb_put(skb, len);
1114 skb_pull(skb, 2); /* pull off A/C bytes */
1115 } else if (len == 0) {
1116 /* didn't compress, or CCP not up yet */
1117 kfree_skb(new_skb);
1118 new_skb = skb;
1119 } else {
1120 /*
1121 * (len < 0)
1122 * MPPE requires that we do not send unencrypted
1123 * frames. The compressor will return -1 if we
1124 * should drop the frame. We cannot simply test
1125 * the compress_proto because MPPE and MPPC share
1126 * the same number.
1127 */
1128 if (net_ratelimit())
1129 printk(KERN_ERR "ppp: compressor dropped pkt\n");
1130 kfree_skb(skb);
1131 kfree_skb(new_skb);
1132 new_skb = NULL;
1133 }
1134 return new_skb;
1135 }
1136
1137 /*
1138 * Compress and send a frame.
1139 * The caller should have locked the xmit path,
1140 * and xmit_pending should be 0.
1141 */
1142 static void
1143 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1144 {
1145 int proto = PPP_PROTO(skb);
1146 struct sk_buff *new_skb;
1147 int len;
1148 unsigned char *cp;
1149
1150 if (proto < 0x8000) {
1151 #ifdef CONFIG_PPP_FILTER
1152 /* check if we should pass this packet */
1153 /* the filter instructions are constructed assuming
1154 a four-byte PPP header on each packet */
1155 *skb_push(skb, 2) = 1;
1156 if (ppp->pass_filter
1157 && sk_run_filter(skb, ppp->pass_filter,
1158 ppp->pass_len) == 0) {
1159 if (ppp->debug & 1)
1160 printk(KERN_DEBUG "PPP: outbound frame not passed\n");
1161 kfree_skb(skb);
1162 return;
1163 }
1164 /* if this packet passes the active filter, record the time */
1165 if (!(ppp->active_filter
1166 && sk_run_filter(skb, ppp->active_filter,
1167 ppp->active_len) == 0))
1168 ppp->last_xmit = jiffies;
1169 skb_pull(skb, 2);
1170 #else
1171 /* for data packets, record the time */
1172 ppp->last_xmit = jiffies;
1173 #endif /* CONFIG_PPP_FILTER */
1174 }
1175
1176 ++ppp->dev->stats.tx_packets;
1177 ppp->dev->stats.tx_bytes += skb->len - 2;
1178
1179 switch (proto) {
1180 case PPP_IP:
1181 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1182 break;
1183 /* try to do VJ TCP header compression */
1184 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1185 GFP_ATOMIC);
1186 if (!new_skb) {
1187 printk(KERN_ERR "PPP: no memory (VJ comp pkt)\n");
1188 goto drop;
1189 }
1190 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1191 cp = skb->data + 2;
1192 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1193 new_skb->data + 2, &cp,
1194 !(ppp->flags & SC_NO_TCP_CCID));
1195 if (cp == skb->data + 2) {
1196 /* didn't compress */
1197 kfree_skb(new_skb);
1198 } else {
1199 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1200 proto = PPP_VJC_COMP;
1201 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1202 } else {
1203 proto = PPP_VJC_UNCOMP;
1204 cp[0] = skb->data[2];
1205 }
1206 kfree_skb(skb);
1207 skb = new_skb;
1208 cp = skb_put(skb, len + 2);
1209 cp[0] = 0;
1210 cp[1] = proto;
1211 }
1212 break;
1213
1214 case PPP_CCP:
1215 /* peek at outbound CCP frames */
1216 ppp_ccp_peek(ppp, skb, 0);
1217 break;
1218 }
1219
1220 /* try to do packet compression */
1221 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state
1222 && proto != PPP_LCP && proto != PPP_CCP) {
1223 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1224 if (net_ratelimit())
1225 printk(KERN_ERR "ppp: compression required but down - pkt dropped.\n");
1226 goto drop;
1227 }
1228 skb = pad_compress_skb(ppp, skb);
1229 if (!skb)
1230 goto drop;
1231 }
1232
1233 /*
1234 * If we are waiting for traffic (demand dialling),
1235 * queue it up for pppd to receive.
1236 */
1237 if (ppp->flags & SC_LOOP_TRAFFIC) {
1238 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1239 goto drop;
1240 skb_queue_tail(&ppp->file.rq, skb);
1241 wake_up_interruptible(&ppp->file.rwait);
1242 return;
1243 }
1244
1245 ppp->xmit_pending = skb;
1246 ppp_push(ppp);
1247 return;
1248
1249 drop:
1250 kfree_skb(skb);
1251 ++ppp->dev->stats.tx_errors;
1252 }
1253
1254 /*
1255 * Try to send the frame in xmit_pending.
1256 * The caller should have the xmit path locked.
1257 */
1258 static void
1259 ppp_push(struct ppp *ppp)
1260 {
1261 struct list_head *list;
1262 struct channel *pch;
1263 struct sk_buff *skb = ppp->xmit_pending;
1264
1265 if (!skb)
1266 return;
1267
1268 list = &ppp->channels;
1269 if (list_empty(list)) {
1270 /* nowhere to send the packet, just drop it */
1271 ppp->xmit_pending = NULL;
1272 kfree_skb(skb);
1273 return;
1274 }
1275
1276 if ((ppp->flags & SC_MULTILINK) == 0) {
1277 /* not doing multilink: send it down the first channel */
1278 list = list->next;
1279 pch = list_entry(list, struct channel, clist);
1280
1281 spin_lock_bh(&pch->downl);
1282 if (pch->chan) {
1283 if (pch->chan->ops->start_xmit(pch->chan, skb))
1284 ppp->xmit_pending = NULL;
1285 } else {
1286 /* channel got unregistered */
1287 kfree_skb(skb);
1288 ppp->xmit_pending = NULL;
1289 }
1290 spin_unlock_bh(&pch->downl);
1291 return;
1292 }
1293
1294 #ifdef CONFIG_PPP_MULTILINK
1295 /* Multilink: fragment the packet over as many links
1296 as can take the packet at the moment. */
1297 if (!ppp_mp_explode(ppp, skb))
1298 return;
1299 #endif /* CONFIG_PPP_MULTILINK */
1300
1301 ppp->xmit_pending = NULL;
1302 kfree_skb(skb);
1303 }
1304
1305 #ifdef CONFIG_PPP_MULTILINK
1306 /*
1307 * Divide a packet to be transmitted into fragments and
1308 * send them out the individual links.
1309 */
1310 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1311 {
1312 int len, totlen;
1313 int i, bits, hdrlen, mtu;
1314 int flen;
1315 int navail, nfree, nzero;
1316 int nbigger;
1317 int totspeed;
1318 int totfree;
1319 unsigned char *p, *q;
1320 struct list_head *list;
1321 struct channel *pch;
1322 struct sk_buff *frag;
1323 struct ppp_channel *chan;
1324
1325 totspeed = 0; /*total bitrate of the bundle*/
1326 nfree = 0; /* # channels which have no packet already queued */
1327 navail = 0; /* total # of usable channels (not deregistered) */
1328 nzero = 0; /* number of channels with zero speed associated*/
1329 totfree = 0; /*total # of channels available and
1330 *having no queued packets before
1331 *starting the fragmentation*/
1332
1333 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1334 i = 0;
1335 list_for_each_entry(pch, &ppp->channels, clist) {
1336 navail += pch->avail = (pch->chan != NULL);
1337 pch->speed = pch->chan->speed;
1338 if (pch->avail) {
1339 if (skb_queue_empty(&pch->file.xq) ||
1340 !pch->had_frag) {
1341 if (pch->speed == 0)
1342 nzero++;
1343 else
1344 totspeed += pch->speed;
1345
1346 pch->avail = 2;
1347 ++nfree;
1348 ++totfree;
1349 }
1350 if (!pch->had_frag && i < ppp->nxchan)
1351 ppp->nxchan = i;
1352 }
1353 ++i;
1354 }
1355 /*
1356 * Don't start sending this packet unless at least half of
1357 * the channels are free. This gives much better TCP
1358 * performance if we have a lot of channels.
1359 */
1360 if (nfree == 0 || nfree < navail / 2)
1361 return 0; /* can't take now, leave it in xmit_pending */
1362
1363 /* Do protocol field compression (XXX this should be optional) */
1364 p = skb->data;
1365 len = skb->len;
1366 if (*p == 0) {
1367 ++p;
1368 --len;
1369 }
1370
1371 totlen = len;
1372 nbigger = len % nfree;
1373
1374 /* skip to the channel after the one we last used
1375 and start at that one */
1376 list = &ppp->channels;
1377 for (i = 0; i < ppp->nxchan; ++i) {
1378 list = list->next;
1379 if (list == &ppp->channels) {
1380 i = 0;
1381 break;
1382 }
1383 }
1384
1385 /* create a fragment for each channel */
1386 bits = B;
1387 while (nfree > 0 && len > 0) {
1388 list = list->next;
1389 if (list == &ppp->channels) {
1390 i = 0;
1391 continue;
1392 }
1393 pch = list_entry(list, struct channel, clist);
1394 ++i;
1395 if (!pch->avail)
1396 continue;
1397
1398 /*
1399 * Skip this channel if it has a fragment pending already and
1400 * we haven't given a fragment to all of the free channels.
1401 */
1402 if (pch->avail == 1) {
1403 if (nfree > 0)
1404 continue;
1405 } else {
1406 pch->avail = 1;
1407 }
1408
1409 /* check the channel's mtu and whether it is still attached. */
1410 spin_lock_bh(&pch->downl);
1411 if (pch->chan == NULL) {
1412 /* can't use this channel, it's being deregistered */
1413 if (pch->speed == 0)
1414 nzero--;
1415 else
1416 totspeed -= pch->speed;
1417
1418 spin_unlock_bh(&pch->downl);
1419 pch->avail = 0;
1420 totlen = len;
1421 totfree--;
1422 nfree--;
1423 if (--navail == 0)
1424 break;
1425 continue;
1426 }
1427
1428 /*
1429 *if the channel speed is not set divide
1430 *the packet evenly among the free channels;
1431 *otherwise divide it according to the speed
1432 *of the channel we are going to transmit on
1433 */
1434 if (pch->speed == 0) {
1435 flen = totlen/nfree ;
1436 if (nbigger > 0) {
1437 flen++;
1438 nbigger--;
1439 }
1440 } else {
1441 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
1442 ((totspeed*totfree)/pch->speed)) - hdrlen;
1443 if (nbigger > 0) {
1444 flen += ((totfree - nzero)*pch->speed)/totspeed;
1445 nbigger -= ((totfree - nzero)*pch->speed)/
1446 totspeed;
1447 }
1448 }
1449 nfree--;
1450
1451 /*
1452 *check if we are on the last channel or
1453 *we exceded the lenght of the data to
1454 *fragment
1455 */
1456 if ((nfree == 0) || (flen > len))
1457 flen = len;
1458 /*
1459 *it is not worth to tx on slow channels:
1460 *in that case from the resulting flen according to the
1461 *above formula will be equal or less than zero.
1462 *Skip the channel in this case
1463 */
1464 if (flen <= 0) {
1465 pch->avail = 2;
1466 spin_unlock_bh(&pch->downl);
1467 continue;
1468 }
1469
1470 mtu = pch->chan->mtu + 2 - hdrlen;
1471 if (mtu < 4)
1472 mtu = 4;
1473 if (flen > mtu)
1474 flen = mtu;
1475 if (flen == len)
1476 bits |= E;
1477 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1478 if (!frag)
1479 goto noskb;
1480 q = skb_put(frag, flen + hdrlen);
1481
1482 /* make the MP header */
1483 q[0] = PPP_MP >> 8;
1484 q[1] = PPP_MP;
1485 if (ppp->flags & SC_MP_XSHORTSEQ) {
1486 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1487 q[3] = ppp->nxseq;
1488 } else {
1489 q[2] = bits;
1490 q[3] = ppp->nxseq >> 16;
1491 q[4] = ppp->nxseq >> 8;
1492 q[5] = ppp->nxseq;
1493 }
1494
1495 memcpy(q + hdrlen, p, flen);
1496
1497 /* try to send it down the channel */
1498 chan = pch->chan;
1499 if (!skb_queue_empty(&pch->file.xq) ||
1500 !chan->ops->start_xmit(chan, frag))
1501 skb_queue_tail(&pch->file.xq, frag);
1502 pch->had_frag = 1;
1503 p += flen;
1504 len -= flen;
1505 ++ppp->nxseq;
1506 bits = 0;
1507 spin_unlock_bh(&pch->downl);
1508 }
1509 ppp->nxchan = i;
1510
1511 return 1;
1512
1513 noskb:
1514 spin_unlock_bh(&pch->downl);
1515 if (ppp->debug & 1)
1516 printk(KERN_ERR "PPP: no memory (fragment)\n");
1517 ++ppp->dev->stats.tx_errors;
1518 ++ppp->nxseq;
1519 return 1; /* abandon the frame */
1520 }
1521 #endif /* CONFIG_PPP_MULTILINK */
1522
1523 /*
1524 * Try to send data out on a channel.
1525 */
1526 static void
1527 ppp_channel_push(struct channel *pch)
1528 {
1529 struct sk_buff *skb;
1530 struct ppp *ppp;
1531
1532 spin_lock_bh(&pch->downl);
1533 if (pch->chan) {
1534 while (!skb_queue_empty(&pch->file.xq)) {
1535 skb = skb_dequeue(&pch->file.xq);
1536 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1537 /* put the packet back and try again later */
1538 skb_queue_head(&pch->file.xq, skb);
1539 break;
1540 }
1541 }
1542 } else {
1543 /* channel got deregistered */
1544 skb_queue_purge(&pch->file.xq);
1545 }
1546 spin_unlock_bh(&pch->downl);
1547 /* see if there is anything from the attached unit to be sent */
1548 if (skb_queue_empty(&pch->file.xq)) {
1549 read_lock_bh(&pch->upl);
1550 ppp = pch->ppp;
1551 if (ppp)
1552 ppp_xmit_process(ppp);
1553 read_unlock_bh(&pch->upl);
1554 }
1555 }
1556
1557 /*
1558 * Receive-side routines.
1559 */
1560
1561 /* misuse a few fields of the skb for MP reconstruction */
1562 #define sequence priority
1563 #define BEbits cb[0]
1564
1565 static inline void
1566 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1567 {
1568 ppp_recv_lock(ppp);
1569 if (!ppp->closing)
1570 ppp_receive_frame(ppp, skb, pch);
1571 else
1572 kfree_skb(skb);
1573 ppp_recv_unlock(ppp);
1574 }
1575
1576 void
1577 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1578 {
1579 struct channel *pch = chan->ppp;
1580 int proto;
1581
1582 if (!pch || skb->len == 0) {
1583 kfree_skb(skb);
1584 return;
1585 }
1586
1587 proto = PPP_PROTO(skb);
1588 read_lock_bh(&pch->upl);
1589 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1590 /* put it on the channel queue */
1591 skb_queue_tail(&pch->file.rq, skb);
1592 /* drop old frames if queue too long */
1593 while (pch->file.rq.qlen > PPP_MAX_RQLEN
1594 && (skb = skb_dequeue(&pch->file.rq)))
1595 kfree_skb(skb);
1596 wake_up_interruptible(&pch->file.rwait);
1597 } else {
1598 ppp_do_recv(pch->ppp, skb, pch);
1599 }
1600 read_unlock_bh(&pch->upl);
1601 }
1602
1603 /* Put a 0-length skb in the receive queue as an error indication */
1604 void
1605 ppp_input_error(struct ppp_channel *chan, int code)
1606 {
1607 struct channel *pch = chan->ppp;
1608 struct sk_buff *skb;
1609
1610 if (!pch)
1611 return;
1612
1613 read_lock_bh(&pch->upl);
1614 if (pch->ppp) {
1615 skb = alloc_skb(0, GFP_ATOMIC);
1616 if (skb) {
1617 skb->len = 0; /* probably unnecessary */
1618 skb->cb[0] = code;
1619 ppp_do_recv(pch->ppp, skb, pch);
1620 }
1621 }
1622 read_unlock_bh(&pch->upl);
1623 }
1624
1625 /*
1626 * We come in here to process a received frame.
1627 * The receive side of the ppp unit is locked.
1628 */
1629 static void
1630 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1631 {
1632 if (pskb_may_pull(skb, 2)) {
1633 #ifdef CONFIG_PPP_MULTILINK
1634 /* XXX do channel-level decompression here */
1635 if (PPP_PROTO(skb) == PPP_MP)
1636 ppp_receive_mp_frame(ppp, skb, pch);
1637 else
1638 #endif /* CONFIG_PPP_MULTILINK */
1639 ppp_receive_nonmp_frame(ppp, skb);
1640 return;
1641 }
1642
1643 if (skb->len > 0)
1644 /* note: a 0-length skb is used as an error indication */
1645 ++ppp->dev->stats.rx_length_errors;
1646
1647 kfree_skb(skb);
1648 ppp_receive_error(ppp);
1649 }
1650
1651 static void
1652 ppp_receive_error(struct ppp *ppp)
1653 {
1654 ++ppp->dev->stats.rx_errors;
1655 if (ppp->vj)
1656 slhc_toss(ppp->vj);
1657 }
1658
1659 static void
1660 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1661 {
1662 struct sk_buff *ns;
1663 int proto, len, npi;
1664
1665 /*
1666 * Decompress the frame, if compressed.
1667 * Note that some decompressors need to see uncompressed frames
1668 * that come in as well as compressed frames.
1669 */
1670 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)
1671 && (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1672 skb = ppp_decompress_frame(ppp, skb);
1673
1674 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1675 goto err;
1676
1677 proto = PPP_PROTO(skb);
1678 switch (proto) {
1679 case PPP_VJC_COMP:
1680 /* decompress VJ compressed packets */
1681 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1682 goto err;
1683
1684 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1685 /* copy to a new sk_buff with more tailroom */
1686 ns = dev_alloc_skb(skb->len + 128);
1687 if (!ns) {
1688 printk(KERN_ERR"PPP: no memory (VJ decomp)\n");
1689 goto err;
1690 }
1691 skb_reserve(ns, 2);
1692 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1693 kfree_skb(skb);
1694 skb = ns;
1695 }
1696 else
1697 skb->ip_summed = CHECKSUM_NONE;
1698
1699 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1700 if (len <= 0) {
1701 printk(KERN_DEBUG "PPP: VJ decompression error\n");
1702 goto err;
1703 }
1704 len += 2;
1705 if (len > skb->len)
1706 skb_put(skb, len - skb->len);
1707 else if (len < skb->len)
1708 skb_trim(skb, len);
1709 proto = PPP_IP;
1710 break;
1711
1712 case PPP_VJC_UNCOMP:
1713 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1714 goto err;
1715
1716 /* Until we fix the decompressor need to make sure
1717 * data portion is linear.
1718 */
1719 if (!pskb_may_pull(skb, skb->len))
1720 goto err;
1721
1722 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1723 printk(KERN_ERR "PPP: VJ uncompressed error\n");
1724 goto err;
1725 }
1726 proto = PPP_IP;
1727 break;
1728
1729 case PPP_CCP:
1730 ppp_ccp_peek(ppp, skb, 1);
1731 break;
1732 }
1733
1734 ++ppp->dev->stats.rx_packets;
1735 ppp->dev->stats.rx_bytes += skb->len - 2;
1736
1737 npi = proto_to_npindex(proto);
1738 if (npi < 0) {
1739 /* control or unknown frame - pass it to pppd */
1740 skb_queue_tail(&ppp->file.rq, skb);
1741 /* limit queue length by dropping old frames */
1742 while (ppp->file.rq.qlen > PPP_MAX_RQLEN
1743 && (skb = skb_dequeue(&ppp->file.rq)))
1744 kfree_skb(skb);
1745 /* wake up any process polling or blocking on read */
1746 wake_up_interruptible(&ppp->file.rwait);
1747
1748 } else {
1749 /* network protocol frame - give it to the kernel */
1750
1751 #ifdef CONFIG_PPP_FILTER
1752 /* check if the packet passes the pass and active filters */
1753 /* the filter instructions are constructed assuming
1754 a four-byte PPP header on each packet */
1755 if (ppp->pass_filter || ppp->active_filter) {
1756 if (skb_cloned(skb) &&
1757 pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
1758 goto err;
1759
1760 *skb_push(skb, 2) = 0;
1761 if (ppp->pass_filter
1762 && sk_run_filter(skb, ppp->pass_filter,
1763 ppp->pass_len) == 0) {
1764 if (ppp->debug & 1)
1765 printk(KERN_DEBUG "PPP: inbound frame "
1766 "not passed\n");
1767 kfree_skb(skb);
1768 return;
1769 }
1770 if (!(ppp->active_filter
1771 && sk_run_filter(skb, ppp->active_filter,
1772 ppp->active_len) == 0))
1773 ppp->last_recv = jiffies;
1774 __skb_pull(skb, 2);
1775 } else
1776 #endif /* CONFIG_PPP_FILTER */
1777 ppp->last_recv = jiffies;
1778
1779 if ((ppp->dev->flags & IFF_UP) == 0
1780 || ppp->npmode[npi] != NPMODE_PASS) {
1781 kfree_skb(skb);
1782 } else {
1783 /* chop off protocol */
1784 skb_pull_rcsum(skb, 2);
1785 skb->dev = ppp->dev;
1786 skb->protocol = htons(npindex_to_ethertype[npi]);
1787 skb_reset_mac_header(skb);
1788 netif_rx(skb);
1789 }
1790 }
1791 return;
1792
1793 err:
1794 kfree_skb(skb);
1795 ppp_receive_error(ppp);
1796 }
1797
1798 static struct sk_buff *
1799 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1800 {
1801 int proto = PPP_PROTO(skb);
1802 struct sk_buff *ns;
1803 int len;
1804
1805 /* Until we fix all the decompressor's need to make sure
1806 * data portion is linear.
1807 */
1808 if (!pskb_may_pull(skb, skb->len))
1809 goto err;
1810
1811 if (proto == PPP_COMP) {
1812 int obuff_size;
1813
1814 switch(ppp->rcomp->compress_proto) {
1815 case CI_MPPE:
1816 obuff_size = ppp->mru + PPP_HDRLEN + 1;
1817 break;
1818 default:
1819 obuff_size = ppp->mru + PPP_HDRLEN;
1820 break;
1821 }
1822
1823 ns = dev_alloc_skb(obuff_size);
1824 if (!ns) {
1825 printk(KERN_ERR "ppp_decompress_frame: no memory\n");
1826 goto err;
1827 }
1828 /* the decompressor still expects the A/C bytes in the hdr */
1829 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1830 skb->len + 2, ns->data, obuff_size);
1831 if (len < 0) {
1832 /* Pass the compressed frame to pppd as an
1833 error indication. */
1834 if (len == DECOMP_FATALERROR)
1835 ppp->rstate |= SC_DC_FERROR;
1836 kfree_skb(ns);
1837 goto err;
1838 }
1839
1840 kfree_skb(skb);
1841 skb = ns;
1842 skb_put(skb, len);
1843 skb_pull(skb, 2); /* pull off the A/C bytes */
1844
1845 } else {
1846 /* Uncompressed frame - pass to decompressor so it
1847 can update its dictionary if necessary. */
1848 if (ppp->rcomp->incomp)
1849 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1850 skb->len + 2);
1851 }
1852
1853 return skb;
1854
1855 err:
1856 ppp->rstate |= SC_DC_ERROR;
1857 ppp_receive_error(ppp);
1858 return skb;
1859 }
1860
1861 #ifdef CONFIG_PPP_MULTILINK
1862 /*
1863 * Receive a multilink frame.
1864 * We put it on the reconstruction queue and then pull off
1865 * as many completed frames as we can.
1866 */
1867 static void
1868 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1869 {
1870 u32 mask, seq;
1871 struct channel *ch;
1872 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1873
1874 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
1875 goto err; /* no good, throw it away */
1876
1877 /* Decode sequence number and begin/end bits */
1878 if (ppp->flags & SC_MP_SHORTSEQ) {
1879 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1880 mask = 0xfff;
1881 } else {
1882 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1883 mask = 0xffffff;
1884 }
1885 skb->BEbits = skb->data[2];
1886 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
1887
1888 /*
1889 * Do protocol ID decompression on the first fragment of each packet.
1890 */
1891 if ((skb->BEbits & B) && (skb->data[0] & 1))
1892 *skb_push(skb, 1) = 0;
1893
1894 /*
1895 * Expand sequence number to 32 bits, making it as close
1896 * as possible to ppp->minseq.
1897 */
1898 seq |= ppp->minseq & ~mask;
1899 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
1900 seq += mask + 1;
1901 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
1902 seq -= mask + 1; /* should never happen */
1903 skb->sequence = seq;
1904 pch->lastseq = seq;
1905
1906 /*
1907 * If this packet comes before the next one we were expecting,
1908 * drop it.
1909 */
1910 if (seq_before(seq, ppp->nextseq)) {
1911 kfree_skb(skb);
1912 ++ppp->dev->stats.rx_dropped;
1913 ppp_receive_error(ppp);
1914 return;
1915 }
1916
1917 /*
1918 * Reevaluate minseq, the minimum over all channels of the
1919 * last sequence number received on each channel. Because of
1920 * the increasing sequence number rule, we know that any fragment
1921 * before `minseq' which hasn't arrived is never going to arrive.
1922 * The list of channels can't change because we have the receive
1923 * side of the ppp unit locked.
1924 */
1925 list_for_each_entry(ch, &ppp->channels, clist) {
1926 if (seq_before(ch->lastseq, seq))
1927 seq = ch->lastseq;
1928 }
1929 if (seq_before(ppp->minseq, seq))
1930 ppp->minseq = seq;
1931
1932 /* Put the fragment on the reconstruction queue */
1933 ppp_mp_insert(ppp, skb);
1934
1935 /* If the queue is getting long, don't wait any longer for packets
1936 before the start of the queue. */
1937 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
1938 struct sk_buff *skb = skb_peek(&ppp->mrq);
1939 if (seq_before(ppp->minseq, skb->sequence))
1940 ppp->minseq = skb->sequence;
1941 }
1942
1943 /* Pull completed packets off the queue and receive them. */
1944 while ((skb = ppp_mp_reconstruct(ppp)))
1945 ppp_receive_nonmp_frame(ppp, skb);
1946
1947 return;
1948
1949 err:
1950 kfree_skb(skb);
1951 ppp_receive_error(ppp);
1952 }
1953
1954 /*
1955 * Insert a fragment on the MP reconstruction queue.
1956 * The queue is ordered by increasing sequence number.
1957 */
1958 static void
1959 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
1960 {
1961 struct sk_buff *p;
1962 struct sk_buff_head *list = &ppp->mrq;
1963 u32 seq = skb->sequence;
1964
1965 /* N.B. we don't need to lock the list lock because we have the
1966 ppp unit receive-side lock. */
1967 skb_queue_walk(list, p) {
1968 if (seq_before(seq, p->sequence))
1969 break;
1970 }
1971 __skb_queue_before(list, p, skb);
1972 }
1973
1974 /*
1975 * Reconstruct a packet from the MP fragment queue.
1976 * We go through increasing sequence numbers until we find a
1977 * complete packet, or we get to the sequence number for a fragment
1978 * which hasn't arrived but might still do so.
1979 */
1980 static struct sk_buff *
1981 ppp_mp_reconstruct(struct ppp *ppp)
1982 {
1983 u32 seq = ppp->nextseq;
1984 u32 minseq = ppp->minseq;
1985 struct sk_buff_head *list = &ppp->mrq;
1986 struct sk_buff *p, *next;
1987 struct sk_buff *head, *tail;
1988 struct sk_buff *skb = NULL;
1989 int lost = 0, len = 0;
1990
1991 if (ppp->mrru == 0) /* do nothing until mrru is set */
1992 return NULL;
1993 head = list->next;
1994 tail = NULL;
1995 for (p = head; p != (struct sk_buff *) list; p = next) {
1996 next = p->next;
1997 if (seq_before(p->sequence, seq)) {
1998 /* this can't happen, anyway ignore the skb */
1999 printk(KERN_ERR "ppp_mp_reconstruct bad seq %u < %u\n",
2000 p->sequence, seq);
2001 head = next;
2002 continue;
2003 }
2004 if (p->sequence != seq) {
2005 /* Fragment `seq' is missing. If it is after
2006 minseq, it might arrive later, so stop here. */
2007 if (seq_after(seq, minseq))
2008 break;
2009 /* Fragment `seq' is lost, keep going. */
2010 lost = 1;
2011 seq = seq_before(minseq, p->sequence)?
2012 minseq + 1: p->sequence;
2013 next = p;
2014 continue;
2015 }
2016
2017 /*
2018 * At this point we know that all the fragments from
2019 * ppp->nextseq to seq are either present or lost.
2020 * Also, there are no complete packets in the queue
2021 * that have no missing fragments and end before this
2022 * fragment.
2023 */
2024
2025 /* B bit set indicates this fragment starts a packet */
2026 if (p->BEbits & B) {
2027 head = p;
2028 lost = 0;
2029 len = 0;
2030 }
2031
2032 len += p->len;
2033
2034 /* Got a complete packet yet? */
2035 if (lost == 0 && (p->BEbits & E) && (head->BEbits & B)) {
2036 if (len > ppp->mrru + 2) {
2037 ++ppp->dev->stats.rx_length_errors;
2038 printk(KERN_DEBUG "PPP: reconstructed packet"
2039 " is too long (%d)\n", len);
2040 } else if (p == head) {
2041 /* fragment is complete packet - reuse skb */
2042 tail = p;
2043 skb = skb_get(p);
2044 break;
2045 } else if ((skb = dev_alloc_skb(len)) == NULL) {
2046 ++ppp->dev->stats.rx_missed_errors;
2047 printk(KERN_DEBUG "PPP: no memory for "
2048 "reconstructed packet");
2049 } else {
2050 tail = p;
2051 break;
2052 }
2053 ppp->nextseq = seq + 1;
2054 }
2055
2056 /*
2057 * If this is the ending fragment of a packet,
2058 * and we haven't found a complete valid packet yet,
2059 * we can discard up to and including this fragment.
2060 */
2061 if (p->BEbits & E)
2062 head = next;
2063
2064 ++seq;
2065 }
2066
2067 /* If we have a complete packet, copy it all into one skb. */
2068 if (tail != NULL) {
2069 /* If we have discarded any fragments,
2070 signal a receive error. */
2071 if (head->sequence != ppp->nextseq) {
2072 if (ppp->debug & 1)
2073 printk(KERN_DEBUG " missed pkts %u..%u\n",
2074 ppp->nextseq, head->sequence-1);
2075 ++ppp->dev->stats.rx_dropped;
2076 ppp_receive_error(ppp);
2077 }
2078
2079 if (head != tail)
2080 /* copy to a single skb */
2081 for (p = head; p != tail->next; p = p->next)
2082 skb_copy_bits(p, 0, skb_put(skb, p->len), p->len);
2083 ppp->nextseq = tail->sequence + 1;
2084 head = tail->next;
2085 }
2086
2087 /* Discard all the skbuffs that we have copied the data out of
2088 or that we can't use. */
2089 while ((p = list->next) != head) {
2090 __skb_unlink(p, list);
2091 kfree_skb(p);
2092 }
2093
2094 return skb;
2095 }
2096 #endif /* CONFIG_PPP_MULTILINK */
2097
2098 /*
2099 * Channel interface.
2100 */
2101
2102 /* Create a new, unattached ppp channel. */
2103 int ppp_register_channel(struct ppp_channel *chan)
2104 {
2105 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2106 }
2107
2108 /* Create a new, unattached ppp channel for specified net. */
2109 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
2110 {
2111 struct channel *pch;
2112 struct ppp_net *pn;
2113
2114 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2115 if (!pch)
2116 return -ENOMEM;
2117
2118 pn = ppp_pernet(net);
2119
2120 pch->ppp = NULL;
2121 pch->chan = chan;
2122 pch->chan_net = net;
2123 chan->ppp = pch;
2124 init_ppp_file(&pch->file, CHANNEL);
2125 pch->file.hdrlen = chan->hdrlen;
2126 #ifdef CONFIG_PPP_MULTILINK
2127 pch->lastseq = -1;
2128 #endif /* CONFIG_PPP_MULTILINK */
2129 init_rwsem(&pch->chan_sem);
2130 spin_lock_init(&pch->downl);
2131 rwlock_init(&pch->upl);
2132
2133 spin_lock_bh(&pn->all_channels_lock);
2134 pch->file.index = ++pn->last_channel_index;
2135 list_add(&pch->list, &pn->new_channels);
2136 atomic_inc(&channel_count);
2137 spin_unlock_bh(&pn->all_channels_lock);
2138
2139 return 0;
2140 }
2141
2142 /*
2143 * Return the index of a channel.
2144 */
2145 int ppp_channel_index(struct ppp_channel *chan)
2146 {
2147 struct channel *pch = chan->ppp;
2148
2149 if (pch)
2150 return pch->file.index;
2151 return -1;
2152 }
2153
2154 /*
2155 * Return the PPP unit number to which a channel is connected.
2156 */
2157 int ppp_unit_number(struct ppp_channel *chan)
2158 {
2159 struct channel *pch = chan->ppp;
2160 int unit = -1;
2161
2162 if (pch) {
2163 read_lock_bh(&pch->upl);
2164 if (pch->ppp)
2165 unit = pch->ppp->file.index;
2166 read_unlock_bh(&pch->upl);
2167 }
2168 return unit;
2169 }
2170
2171 /*
2172 * Disconnect a channel from the generic layer.
2173 * This must be called in process context.
2174 */
2175 void
2176 ppp_unregister_channel(struct ppp_channel *chan)
2177 {
2178 struct channel *pch = chan->ppp;
2179 struct ppp_net *pn;
2180
2181 if (!pch)
2182 return; /* should never happen */
2183
2184 chan->ppp = NULL;
2185
2186 /*
2187 * This ensures that we have returned from any calls into the
2188 * the channel's start_xmit or ioctl routine before we proceed.
2189 */
2190 down_write(&pch->chan_sem);
2191 spin_lock_bh(&pch->downl);
2192 pch->chan = NULL;
2193 spin_unlock_bh(&pch->downl);
2194 up_write(&pch->chan_sem);
2195 ppp_disconnect_channel(pch);
2196
2197 pn = ppp_pernet(pch->chan_net);
2198 spin_lock_bh(&pn->all_channels_lock);
2199 list_del(&pch->list);
2200 spin_unlock_bh(&pn->all_channels_lock);
2201
2202 pch->file.dead = 1;
2203 wake_up_interruptible(&pch->file.rwait);
2204 if (atomic_dec_and_test(&pch->file.refcnt))
2205 ppp_destroy_channel(pch);
2206 }
2207
2208 /*
2209 * Callback from a channel when it can accept more to transmit.
2210 * This should be called at BH/softirq level, not interrupt level.
2211 */
2212 void
2213 ppp_output_wakeup(struct ppp_channel *chan)
2214 {
2215 struct channel *pch = chan->ppp;
2216
2217 if (!pch)
2218 return;
2219 ppp_channel_push(pch);
2220 }
2221
2222 /*
2223 * Compression control.
2224 */
2225
2226 /* Process the PPPIOCSCOMPRESS ioctl. */
2227 static int
2228 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2229 {
2230 int err;
2231 struct compressor *cp, *ocomp;
2232 struct ppp_option_data data;
2233 void *state, *ostate;
2234 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2235
2236 err = -EFAULT;
2237 if (copy_from_user(&data, (void __user *) arg, sizeof(data))
2238 || (data.length <= CCP_MAX_OPTION_LENGTH
2239 && copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2240 goto out;
2241 err = -EINVAL;
2242 if (data.length > CCP_MAX_OPTION_LENGTH
2243 || ccp_option[1] < 2 || ccp_option[1] > data.length)
2244 goto out;
2245
2246 cp = try_then_request_module(
2247 find_compressor(ccp_option[0]),
2248 "ppp-compress-%d", ccp_option[0]);
2249 if (!cp)
2250 goto out;
2251
2252 err = -ENOBUFS;
2253 if (data.transmit) {
2254 state = cp->comp_alloc(ccp_option, data.length);
2255 if (state) {
2256 ppp_xmit_lock(ppp);
2257 ppp->xstate &= ~SC_COMP_RUN;
2258 ocomp = ppp->xcomp;
2259 ostate = ppp->xc_state;
2260 ppp->xcomp = cp;
2261 ppp->xc_state = state;
2262 ppp_xmit_unlock(ppp);
2263 if (ostate) {
2264 ocomp->comp_free(ostate);
2265 module_put(ocomp->owner);
2266 }
2267 err = 0;
2268 } else
2269 module_put(cp->owner);
2270
2271 } else {
2272 state = cp->decomp_alloc(ccp_option, data.length);
2273 if (state) {
2274 ppp_recv_lock(ppp);
2275 ppp->rstate &= ~SC_DECOMP_RUN;
2276 ocomp = ppp->rcomp;
2277 ostate = ppp->rc_state;
2278 ppp->rcomp = cp;
2279 ppp->rc_state = state;
2280 ppp_recv_unlock(ppp);
2281 if (ostate) {
2282 ocomp->decomp_free(ostate);
2283 module_put(ocomp->owner);
2284 }
2285 err = 0;
2286 } else
2287 module_put(cp->owner);
2288 }
2289
2290 out:
2291 return err;
2292 }
2293
2294 /*
2295 * Look at a CCP packet and update our state accordingly.
2296 * We assume the caller has the xmit or recv path locked.
2297 */
2298 static void
2299 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2300 {
2301 unsigned char *dp;
2302 int len;
2303
2304 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2305 return; /* no header */
2306 dp = skb->data + 2;
2307
2308 switch (CCP_CODE(dp)) {
2309 case CCP_CONFREQ:
2310
2311 /* A ConfReq starts negotiation of compression
2312 * in one direction of transmission,
2313 * and hence brings it down...but which way?
2314 *
2315 * Remember:
2316 * A ConfReq indicates what the sender would like to receive
2317 */
2318 if(inbound)
2319 /* He is proposing what I should send */
2320 ppp->xstate &= ~SC_COMP_RUN;
2321 else
2322 /* I am proposing to what he should send */
2323 ppp->rstate &= ~SC_DECOMP_RUN;
2324
2325 break;
2326
2327 case CCP_TERMREQ:
2328 case CCP_TERMACK:
2329 /*
2330 * CCP is going down, both directions of transmission
2331 */
2332 ppp->rstate &= ~SC_DECOMP_RUN;
2333 ppp->xstate &= ~SC_COMP_RUN;
2334 break;
2335
2336 case CCP_CONFACK:
2337 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2338 break;
2339 len = CCP_LENGTH(dp);
2340 if (!pskb_may_pull(skb, len + 2))
2341 return; /* too short */
2342 dp += CCP_HDRLEN;
2343 len -= CCP_HDRLEN;
2344 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2345 break;
2346 if (inbound) {
2347 /* we will start receiving compressed packets */
2348 if (!ppp->rc_state)
2349 break;
2350 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2351 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2352 ppp->rstate |= SC_DECOMP_RUN;
2353 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2354 }
2355 } else {
2356 /* we will soon start sending compressed packets */
2357 if (!ppp->xc_state)
2358 break;
2359 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2360 ppp->file.index, 0, ppp->debug))
2361 ppp->xstate |= SC_COMP_RUN;
2362 }
2363 break;
2364
2365 case CCP_RESETACK:
2366 /* reset the [de]compressor */
2367 if ((ppp->flags & SC_CCP_UP) == 0)
2368 break;
2369 if (inbound) {
2370 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2371 ppp->rcomp->decomp_reset(ppp->rc_state);
2372 ppp->rstate &= ~SC_DC_ERROR;
2373 }
2374 } else {
2375 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2376 ppp->xcomp->comp_reset(ppp->xc_state);
2377 }
2378 break;
2379 }
2380 }
2381
2382 /* Free up compression resources. */
2383 static void
2384 ppp_ccp_closed(struct ppp *ppp)
2385 {
2386 void *xstate, *rstate;
2387 struct compressor *xcomp, *rcomp;
2388
2389 ppp_lock(ppp);
2390 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2391 ppp->xstate = 0;
2392 xcomp = ppp->xcomp;
2393 xstate = ppp->xc_state;
2394 ppp->xc_state = NULL;
2395 ppp->rstate = 0;
2396 rcomp = ppp->rcomp;
2397 rstate = ppp->rc_state;
2398 ppp->rc_state = NULL;
2399 ppp_unlock(ppp);
2400
2401 if (xstate) {
2402 xcomp->comp_free(xstate);
2403 module_put(xcomp->owner);
2404 }
2405 if (rstate) {
2406 rcomp->decomp_free(rstate);
2407 module_put(rcomp->owner);
2408 }
2409 }
2410
2411 /* List of compressors. */
2412 static LIST_HEAD(compressor_list);
2413 static DEFINE_SPINLOCK(compressor_list_lock);
2414
2415 struct compressor_entry {
2416 struct list_head list;
2417 struct compressor *comp;
2418 };
2419
2420 static struct compressor_entry *
2421 find_comp_entry(int proto)
2422 {
2423 struct compressor_entry *ce;
2424
2425 list_for_each_entry(ce, &compressor_list, list) {
2426 if (ce->comp->compress_proto == proto)
2427 return ce;
2428 }
2429 return NULL;
2430 }
2431
2432 /* Register a compressor */
2433 int
2434 ppp_register_compressor(struct compressor *cp)
2435 {
2436 struct compressor_entry *ce;
2437 int ret;
2438 spin_lock(&compressor_list_lock);
2439 ret = -EEXIST;
2440 if (find_comp_entry(cp->compress_proto))
2441 goto out;
2442 ret = -ENOMEM;
2443 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2444 if (!ce)
2445 goto out;
2446 ret = 0;
2447 ce->comp = cp;
2448 list_add(&ce->list, &compressor_list);
2449 out:
2450 spin_unlock(&compressor_list_lock);
2451 return ret;
2452 }
2453
2454 /* Unregister a compressor */
2455 void
2456 ppp_unregister_compressor(struct compressor *cp)
2457 {
2458 struct compressor_entry *ce;
2459
2460 spin_lock(&compressor_list_lock);
2461 ce = find_comp_entry(cp->compress_proto);
2462 if (ce && ce->comp == cp) {
2463 list_del(&ce->list);
2464 kfree(ce);
2465 }
2466 spin_unlock(&compressor_list_lock);
2467 }
2468
2469 /* Find a compressor. */
2470 static struct compressor *
2471 find_compressor(int type)
2472 {
2473 struct compressor_entry *ce;
2474 struct compressor *cp = NULL;
2475
2476 spin_lock(&compressor_list_lock);
2477 ce = find_comp_entry(type);
2478 if (ce) {
2479 cp = ce->comp;
2480 if (!try_module_get(cp->owner))
2481 cp = NULL;
2482 }
2483 spin_unlock(&compressor_list_lock);
2484 return cp;
2485 }
2486
2487 /*
2488 * Miscelleneous stuff.
2489 */
2490
2491 static void
2492 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2493 {
2494 struct slcompress *vj = ppp->vj;
2495
2496 memset(st, 0, sizeof(*st));
2497 st->p.ppp_ipackets = ppp->dev->stats.rx_packets;
2498 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2499 st->p.ppp_ibytes = ppp->dev->stats.rx_bytes;
2500 st->p.ppp_opackets = ppp->dev->stats.tx_packets;
2501 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2502 st->p.ppp_obytes = ppp->dev->stats.tx_bytes;
2503 if (!vj)
2504 return;
2505 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2506 st->vj.vjs_compressed = vj->sls_o_compressed;
2507 st->vj.vjs_searches = vj->sls_o_searches;
2508 st->vj.vjs_misses = vj->sls_o_misses;
2509 st->vj.vjs_errorin = vj->sls_i_error;
2510 st->vj.vjs_tossed = vj->sls_i_tossed;
2511 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2512 st->vj.vjs_compressedin = vj->sls_i_compressed;
2513 }
2514
2515 /*
2516 * Stuff for handling the lists of ppp units and channels
2517 * and for initialization.
2518 */
2519
2520 /*
2521 * Create a new ppp interface unit. Fails if it can't allocate memory
2522 * or if there is already a unit with the requested number.
2523 * unit == -1 means allocate a new number.
2524 */
2525 static struct ppp *
2526 ppp_create_interface(struct net *net, int unit, int *retp)
2527 {
2528 struct ppp *ppp;
2529 struct ppp_net *pn;
2530 struct net_device *dev = NULL;
2531 int ret = -ENOMEM;
2532 int i;
2533
2534 dev = alloc_netdev(sizeof(struct ppp), "", ppp_setup);
2535 if (!dev)
2536 goto out1;
2537
2538 pn = ppp_pernet(net);
2539
2540 ppp = netdev_priv(dev);
2541 ppp->dev = dev;
2542 ppp->mru = PPP_MRU;
2543 init_ppp_file(&ppp->file, INTERFACE);
2544 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2545 for (i = 0; i < NUM_NP; ++i)
2546 ppp->npmode[i] = NPMODE_PASS;
2547 INIT_LIST_HEAD(&ppp->channels);
2548 spin_lock_init(&ppp->rlock);
2549 spin_lock_init(&ppp->wlock);
2550 #ifdef CONFIG_PPP_MULTILINK
2551 ppp->minseq = -1;
2552 skb_queue_head_init(&ppp->mrq);
2553 #endif /* CONFIG_PPP_MULTILINK */
2554
2555 /*
2556 * drum roll: don't forget to set
2557 * the net device is belong to
2558 */
2559 dev_net_set(dev, net);
2560
2561 ret = -EEXIST;
2562 mutex_lock(&pn->all_ppp_mutex);
2563
2564 if (unit < 0) {
2565 unit = unit_get(&pn->units_idr, ppp);
2566 if (unit < 0) {
2567 *retp = unit;
2568 goto out2;
2569 }
2570 } else {
2571 if (unit_find(&pn->units_idr, unit))
2572 goto out2; /* unit already exists */
2573 /*
2574 * if caller need a specified unit number
2575 * lets try to satisfy him, otherwise --
2576 * he should better ask us for new unit number
2577 *
2578 * NOTE: yes I know that returning EEXIST it's not
2579 * fair but at least pppd will ask us to allocate
2580 * new unit in this case so user is happy :)
2581 */
2582 unit = unit_set(&pn->units_idr, ppp, unit);
2583 if (unit < 0)
2584 goto out2;
2585 }
2586
2587 /* Initialize the new ppp unit */
2588 ppp->file.index = unit;
2589 sprintf(dev->name, "ppp%d", unit);
2590
2591 ret = register_netdev(dev);
2592 if (ret != 0) {
2593 unit_put(&pn->units_idr, unit);
2594 printk(KERN_ERR "PPP: couldn't register device %s (%d)\n",
2595 dev->name, ret);
2596 goto out2;
2597 }
2598
2599 ppp->ppp_net = net;
2600
2601 atomic_inc(&ppp_unit_count);
2602 mutex_unlock(&pn->all_ppp_mutex);
2603
2604 *retp = 0;
2605 return ppp;
2606
2607 out2:
2608 mutex_unlock(&pn->all_ppp_mutex);
2609 free_netdev(dev);
2610 out1:
2611 *retp = ret;
2612 return NULL;
2613 }
2614
2615 /*
2616 * Initialize a ppp_file structure.
2617 */
2618 static void
2619 init_ppp_file(struct ppp_file *pf, int kind)
2620 {
2621 pf->kind = kind;
2622 skb_queue_head_init(&pf->xq);
2623 skb_queue_head_init(&pf->rq);
2624 atomic_set(&pf->refcnt, 1);
2625 init_waitqueue_head(&pf->rwait);
2626 }
2627
2628 /*
2629 * Take down a ppp interface unit - called when the owning file
2630 * (the one that created the unit) is closed or detached.
2631 */
2632 static void ppp_shutdown_interface(struct ppp *ppp)
2633 {
2634 struct ppp_net *pn;
2635
2636 pn = ppp_pernet(ppp->ppp_net);
2637 mutex_lock(&pn->all_ppp_mutex);
2638
2639 /* This will call dev_close() for us. */
2640 ppp_lock(ppp);
2641 if (!ppp->closing) {
2642 ppp->closing = 1;
2643 ppp_unlock(ppp);
2644 unregister_netdev(ppp->dev);
2645 } else
2646 ppp_unlock(ppp);
2647
2648 unit_put(&pn->units_idr, ppp->file.index);
2649 ppp->file.dead = 1;
2650 ppp->owner = NULL;
2651 wake_up_interruptible(&ppp->file.rwait);
2652
2653 mutex_unlock(&pn->all_ppp_mutex);
2654 }
2655
2656 /*
2657 * Free the memory used by a ppp unit. This is only called once
2658 * there are no channels connected to the unit and no file structs
2659 * that reference the unit.
2660 */
2661 static void ppp_destroy_interface(struct ppp *ppp)
2662 {
2663 atomic_dec(&ppp_unit_count);
2664
2665 if (!ppp->file.dead || ppp->n_channels) {
2666 /* "can't happen" */
2667 printk(KERN_ERR "ppp: destroying ppp struct %p but dead=%d "
2668 "n_channels=%d !\n", ppp, ppp->file.dead,
2669 ppp->n_channels);
2670 return;
2671 }
2672
2673 ppp_ccp_closed(ppp);
2674 if (ppp->vj) {
2675 slhc_free(ppp->vj);
2676 ppp->vj = NULL;
2677 }
2678 skb_queue_purge(&ppp->file.xq);
2679 skb_queue_purge(&ppp->file.rq);
2680 #ifdef CONFIG_PPP_MULTILINK
2681 skb_queue_purge(&ppp->mrq);
2682 #endif /* CONFIG_PPP_MULTILINK */
2683 #ifdef CONFIG_PPP_FILTER
2684 kfree(ppp->pass_filter);
2685 ppp->pass_filter = NULL;
2686 kfree(ppp->active_filter);
2687 ppp->active_filter = NULL;
2688 #endif /* CONFIG_PPP_FILTER */
2689
2690 kfree_skb(ppp->xmit_pending);
2691
2692 free_netdev(ppp->dev);
2693 }
2694
2695 /*
2696 * Locate an existing ppp unit.
2697 * The caller should have locked the all_ppp_mutex.
2698 */
2699 static struct ppp *
2700 ppp_find_unit(struct ppp_net *pn, int unit)
2701 {
2702 return unit_find(&pn->units_idr, unit);
2703 }
2704
2705 /*
2706 * Locate an existing ppp channel.
2707 * The caller should have locked the all_channels_lock.
2708 * First we look in the new_channels list, then in the
2709 * all_channels list. If found in the new_channels list,
2710 * we move it to the all_channels list. This is for speed
2711 * when we have a lot of channels in use.
2712 */
2713 static struct channel *
2714 ppp_find_channel(struct ppp_net *pn, int unit)
2715 {
2716 struct channel *pch;
2717
2718 list_for_each_entry(pch, &pn->new_channels, list) {
2719 if (pch->file.index == unit) {
2720 list_move(&pch->list, &pn->all_channels);
2721 return pch;
2722 }
2723 }
2724
2725 list_for_each_entry(pch, &pn->all_channels, list) {
2726 if (pch->file.index == unit)
2727 return pch;
2728 }
2729
2730 return NULL;
2731 }
2732
2733 /*
2734 * Connect a PPP channel to a PPP interface unit.
2735 */
2736 static int
2737 ppp_connect_channel(struct channel *pch, int unit)
2738 {
2739 struct ppp *ppp;
2740 struct ppp_net *pn;
2741 int ret = -ENXIO;
2742 int hdrlen;
2743
2744 pn = ppp_pernet(pch->chan_net);
2745
2746 mutex_lock(&pn->all_ppp_mutex);
2747 ppp = ppp_find_unit(pn, unit);
2748 if (!ppp)
2749 goto out;
2750 write_lock_bh(&pch->upl);
2751 ret = -EINVAL;
2752 if (pch->ppp)
2753 goto outl;
2754
2755 ppp_lock(ppp);
2756 if (pch->file.hdrlen > ppp->file.hdrlen)
2757 ppp->file.hdrlen = pch->file.hdrlen;
2758 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2759 if (hdrlen > ppp->dev->hard_header_len)
2760 ppp->dev->hard_header_len = hdrlen;
2761 list_add_tail(&pch->clist, &ppp->channels);
2762 ++ppp->n_channels;
2763 pch->ppp = ppp;
2764 atomic_inc(&ppp->file.refcnt);
2765 ppp_unlock(ppp);
2766 ret = 0;
2767
2768 outl:
2769 write_unlock_bh(&pch->upl);
2770 out:
2771 mutex_unlock(&pn->all_ppp_mutex);
2772 return ret;
2773 }
2774
2775 /*
2776 * Disconnect a channel from its ppp unit.
2777 */
2778 static int
2779 ppp_disconnect_channel(struct channel *pch)
2780 {
2781 struct ppp *ppp;
2782 int err = -EINVAL;
2783
2784 write_lock_bh(&pch->upl);
2785 ppp = pch->ppp;
2786 pch->ppp = NULL;
2787 write_unlock_bh(&pch->upl);
2788 if (ppp) {
2789 /* remove it from the ppp unit's list */
2790 ppp_lock(ppp);
2791 list_del(&pch->clist);
2792 if (--ppp->n_channels == 0)
2793 wake_up_interruptible(&ppp->file.rwait);
2794 ppp_unlock(ppp);
2795 if (atomic_dec_and_test(&ppp->file.refcnt))
2796 ppp_destroy_interface(ppp);
2797 err = 0;
2798 }
2799 return err;
2800 }
2801
2802 /*
2803 * Free up the resources used by a ppp channel.
2804 */
2805 static void ppp_destroy_channel(struct channel *pch)
2806 {
2807 atomic_dec(&channel_count);
2808
2809 if (!pch->file.dead) {
2810 /* "can't happen" */
2811 printk(KERN_ERR "ppp: destroying undead channel %p !\n",
2812 pch);
2813 return;
2814 }
2815 skb_queue_purge(&pch->file.xq);
2816 skb_queue_purge(&pch->file.rq);
2817 kfree(pch);
2818 }
2819
2820 static void __exit ppp_cleanup(void)
2821 {
2822 /* should never happen */
2823 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2824 printk(KERN_ERR "PPP: removing module but units remain!\n");
2825 unregister_chrdev(PPP_MAJOR, "ppp");
2826 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
2827 class_destroy(ppp_class);
2828 unregister_pernet_gen_device(ppp_net_id, &ppp_net_ops);
2829 }
2830
2831 /*
2832 * Units handling. Caller must protect concurrent access
2833 * by holding all_ppp_mutex
2834 */
2835
2836 /* associate pointer with specified number */
2837 static int unit_set(struct idr *p, void *ptr, int n)
2838 {
2839 int unit, err;
2840
2841 again:
2842 if (!idr_pre_get(p, GFP_KERNEL)) {
2843 printk(KERN_ERR "PPP: No free memory for idr\n");
2844 return -ENOMEM;
2845 }
2846
2847 err = idr_get_new_above(p, ptr, n, &unit);
2848 if (err == -EAGAIN)
2849 goto again;
2850
2851 if (unit != n) {
2852 idr_remove(p, unit);
2853 return -EINVAL;
2854 }
2855
2856 return unit;
2857 }
2858
2859 /* get new free unit number and associate pointer with it */
2860 static int unit_get(struct idr *p, void *ptr)
2861 {
2862 int unit, err;
2863
2864 again:
2865 if (!idr_pre_get(p, GFP_KERNEL)) {
2866 printk(KERN_ERR "PPP: No free memory for idr\n");
2867 return -ENOMEM;
2868 }
2869
2870 err = idr_get_new_above(p, ptr, 0, &unit);
2871 if (err == -EAGAIN)
2872 goto again;
2873
2874 return unit;
2875 }
2876
2877 /* put unit number back to a pool */
2878 static void unit_put(struct idr *p, int n)
2879 {
2880 idr_remove(p, n);
2881 }
2882
2883 /* get pointer associated with the number */
2884 static void *unit_find(struct idr *p, int n)
2885 {
2886 return idr_find(p, n);
2887 }
2888
2889 /* Module/initialization stuff */
2890
2891 module_init(ppp_init);
2892 module_exit(ppp_cleanup);
2893
2894 EXPORT_SYMBOL(ppp_register_net_channel);
2895 EXPORT_SYMBOL(ppp_register_channel);
2896 EXPORT_SYMBOL(ppp_unregister_channel);
2897 EXPORT_SYMBOL(ppp_channel_index);
2898 EXPORT_SYMBOL(ppp_unit_number);
2899 EXPORT_SYMBOL(ppp_input);
2900 EXPORT_SYMBOL(ppp_input_error);
2901 EXPORT_SYMBOL(ppp_output_wakeup);
2902 EXPORT_SYMBOL(ppp_register_compressor);
2903 EXPORT_SYMBOL(ppp_unregister_compressor);
2904 MODULE_LICENSE("GPL");
2905 MODULE_ALIAS_CHARDEV_MAJOR(PPP_MAJOR);
2906 MODULE_ALIAS("/dev/ppp");
Support for the Chinese Samsung S3C2440 based development boards