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ip: fix truesize mismatch in ip fragmentation
[linux/fpc-iii.git] / drivers / net / ppp_generic.c
blob1b2c29150202080e75c2e9732b0150c204ed9161
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 <linux/slab.h>
50 #include <net/slhc_vj.h>
51 #include <asm/atomic.h>
52
53 #include <linux/nsproxy.h>
54 #include <net/net_namespace.h>
55 #include <net/netns/generic.h>
56
57 #define PPP_VERSION "2.4.2"
58
59 /*
60 * Network protocols we support.
61 */
62 #define NP_IP 0 /* Internet Protocol V4 */
63 #define NP_IPV6 1 /* Internet Protocol V6 */
64 #define NP_IPX 2 /* IPX protocol */
65 #define NP_AT 3 /* Appletalk protocol */
66 #define NP_MPLS_UC 4 /* MPLS unicast */
67 #define NP_MPLS_MC 5 /* MPLS multicast */
68 #define NUM_NP 6 /* Number of NPs. */
69
70 #define MPHDRLEN 6 /* multilink protocol header length */
71 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */
72 #define MIN_FRAG_SIZE 64
73
74 /*
75 * An instance of /dev/ppp can be associated with either a ppp
76 * interface unit or a ppp channel. In both cases, file->private_data
77 * points to one of these.
78 */
79 struct ppp_file {
80 enum {
81 INTERFACE=1, CHANNEL
82 } kind;
83 struct sk_buff_head xq; /* pppd transmit queue */
84 struct sk_buff_head rq; /* receive queue for pppd */
85 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */
86 atomic_t refcnt; /* # refs (incl /dev/ppp attached) */
87 int hdrlen; /* space to leave for headers */
88 int index; /* interface unit / channel number */
89 int dead; /* unit/channel has been shut down */
90 };
91
92 #define PF_TO_X(pf, X) container_of(pf, X, file)
93
94 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
95 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
96
97 /*
98 * Data structure describing one ppp unit.
99 * A ppp unit corresponds to a ppp network interface device
100 * and represents a multilink bundle.
101 * It can have 0 or more ppp channels connected to it.
102 */
103 struct ppp {
104 struct ppp_file file; /* stuff for read/write/poll 0 */
105 struct file *owner; /* file that owns this unit 48 */
106 struct list_head channels; /* list of attached channels 4c */
107 int n_channels; /* how many channels are attached 54 */
108 spinlock_t rlock; /* lock for receive side 58 */
109 spinlock_t wlock; /* lock for transmit side 5c */
110 int mru; /* max receive unit 60 */
111 unsigned int flags; /* control bits 64 */
112 unsigned int xstate; /* transmit state bits 68 */
113 unsigned int rstate; /* receive state bits 6c */
114 int debug; /* debug flags 70 */
115 struct slcompress *vj; /* state for VJ header compression */
116 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
117 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
118 struct compressor *xcomp; /* transmit packet compressor 8c */
119 void *xc_state; /* its internal state 90 */
120 struct compressor *rcomp; /* receive decompressor 94 */
121 void *rc_state; /* its internal state 98 */
122 unsigned long last_xmit; /* jiffies when last pkt sent 9c */
123 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
124 struct net_device *dev; /* network interface device a4 */
125 int closing; /* is device closing down? a8 */
126 #ifdef CONFIG_PPP_MULTILINK
127 int nxchan; /* next channel to send something on */
128 u32 nxseq; /* next sequence number to send */
129 int mrru; /* MP: max reconst. receive unit */
130 u32 nextseq; /* MP: seq no of next packet */
131 u32 minseq; /* MP: min of most recent seqnos */
132 struct sk_buff_head mrq; /* MP: receive reconstruction queue */
133 #endif /* CONFIG_PPP_MULTILINK */
134 #ifdef CONFIG_PPP_FILTER
135 struct sock_filter *pass_filter; /* filter for packets to pass */
136 struct sock_filter *active_filter;/* filter for pkts to reset idle */
137 unsigned pass_len, active_len;
138 #endif /* CONFIG_PPP_FILTER */
139 struct net *ppp_net; /* the net we belong to */
140 };
141
142 /*
143 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
144 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
145 * SC_MUST_COMP
146 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
147 * Bits in xstate: SC_COMP_RUN
148 */
149 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
150 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
151 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
152
153 /*
154 * Private data structure for each channel.
155 * This includes the data structure used for multilink.
156 */
157 struct channel {
158 struct ppp_file file; /* stuff for read/write/poll */
159 struct list_head list; /* link in all/new_channels list */
160 struct ppp_channel *chan; /* public channel data structure */
161 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
162 spinlock_t downl; /* protects `chan', file.xq dequeue */
163 struct ppp *ppp; /* ppp unit we're connected to */
164 struct net *chan_net; /* the net channel belongs to */
165 struct list_head clist; /* link in list of channels per unit */
166 rwlock_t upl; /* protects `ppp' */
167 #ifdef CONFIG_PPP_MULTILINK
168 u8 avail; /* flag used in multilink stuff */
169 u8 had_frag; /* >= 1 fragments have been sent */
170 u32 lastseq; /* MP: last sequence # received */
171 int speed; /* speed of the corresponding ppp channel*/
172 #endif /* CONFIG_PPP_MULTILINK */
173 };
174
175 /*
176 * SMP locking issues:
177 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
178 * list and the ppp.n_channels field, you need to take both locks
179 * before you modify them.
180 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
181 * channel.downl.
182 */
183
184 static atomic_t ppp_unit_count = ATOMIC_INIT(0);
185 static atomic_t channel_count = ATOMIC_INIT(0);
186
187 /* per-net private data for this module */
188 static int ppp_net_id __read_mostly;
189 struct ppp_net {
190 /* units to ppp mapping */
191 struct idr units_idr;
192
193 /*
194 * all_ppp_mutex protects the units_idr mapping.
195 * It also ensures that finding a ppp unit in the units_idr
196 * map and updating its file.refcnt field is atomic.
197 */
198 struct mutex all_ppp_mutex;
199
200 /* channels */
201 struct list_head all_channels;
202 struct list_head new_channels;
203 int last_channel_index;
204
205 /*
206 * all_channels_lock protects all_channels and
207 * last_channel_index, and the atomicity of find
208 * a channel and updating its file.refcnt field.
209 */
210 spinlock_t all_channels_lock;
211 };
212
213 /* Get the PPP protocol number from a skb */
214 #define PPP_PROTO(skb) (((skb)->data[0] << 8) + (skb)->data[1])
215
216 /* We limit the length of ppp->file.rq to this (arbitrary) value */
217 #define PPP_MAX_RQLEN 32
218
219 /*
220 * Maximum number of multilink fragments queued up.
221 * This has to be large enough to cope with the maximum latency of
222 * the slowest channel relative to the others. Strictly it should
223 * depend on the number of channels and their characteristics.
224 */
225 #define PPP_MP_MAX_QLEN 128
226
227 /* Multilink header bits. */
228 #define B 0x80 /* this fragment begins a packet */
229 #define E 0x40 /* this fragment ends a packet */
230
231 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */
232 #define seq_before(a, b) ((s32)((a) - (b)) < 0)
233 #define seq_after(a, b) ((s32)((a) - (b)) > 0)
234
235 /* Prototypes. */
236 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
237 struct file *file, unsigned int cmd, unsigned long arg);
238 static void ppp_xmit_process(struct ppp *ppp);
239 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
240 static void ppp_push(struct ppp *ppp);
241 static void ppp_channel_push(struct channel *pch);
242 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
243 struct channel *pch);
244 static void ppp_receive_error(struct ppp *ppp);
245 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
246 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
247 struct sk_buff *skb);
248 #ifdef CONFIG_PPP_MULTILINK
249 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
250 struct channel *pch);
251 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
252 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
253 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
254 #endif /* CONFIG_PPP_MULTILINK */
255 static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
256 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
257 static void ppp_ccp_closed(struct ppp *ppp);
258 static struct compressor *find_compressor(int type);
259 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
260 static struct ppp *ppp_create_interface(struct net *net, int unit, int *retp);
261 static void init_ppp_file(struct ppp_file *pf, int kind);
262 static void ppp_shutdown_interface(struct ppp *ppp);
263 static void ppp_destroy_interface(struct ppp *ppp);
264 static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit);
265 static struct channel *ppp_find_channel(struct ppp_net *pn, int unit);
266 static int ppp_connect_channel(struct channel *pch, int unit);
267 static int ppp_disconnect_channel(struct channel *pch);
268 static void ppp_destroy_channel(struct channel *pch);
269 static int unit_get(struct idr *p, void *ptr);
270 static int unit_set(struct idr *p, void *ptr, int n);
271 static void unit_put(struct idr *p, int n);
272 static void *unit_find(struct idr *p, int n);
273
274 static struct class *ppp_class;
275
276 /* per net-namespace data */
277 static inline struct ppp_net *ppp_pernet(struct net *net)
278 {
279 BUG_ON(!net);
280
281 return net_generic(net, ppp_net_id);
282 }
283
284 /* Translates a PPP protocol number to a NP index (NP == network protocol) */
285 static inline int proto_to_npindex(int proto)
286 {
287 switch (proto) {
288 case PPP_IP:
289 return NP_IP;
290 case PPP_IPV6:
291 return NP_IPV6;
292 case PPP_IPX:
293 return NP_IPX;
294 case PPP_AT:
295 return NP_AT;
296 case PPP_MPLS_UC:
297 return NP_MPLS_UC;
298 case PPP_MPLS_MC:
299 return NP_MPLS_MC;
300 }
301 return -EINVAL;
302 }
303
304 /* Translates an NP index into a PPP protocol number */
305 static const int npindex_to_proto[NUM_NP] = {
306 PPP_IP,
307 PPP_IPV6,
308 PPP_IPX,
309 PPP_AT,
310 PPP_MPLS_UC,
311 PPP_MPLS_MC,
312 };
313
314 /* Translates an ethertype into an NP index */
315 static inline int ethertype_to_npindex(int ethertype)
316 {
317 switch (ethertype) {
318 case ETH_P_IP:
319 return NP_IP;
320 case ETH_P_IPV6:
321 return NP_IPV6;
322 case ETH_P_IPX:
323 return NP_IPX;
324 case ETH_P_PPPTALK:
325 case ETH_P_ATALK:
326 return NP_AT;
327 case ETH_P_MPLS_UC:
328 return NP_MPLS_UC;
329 case ETH_P_MPLS_MC:
330 return NP_MPLS_MC;
331 }
332 return -1;
333 }
334
335 /* Translates an NP index into an ethertype */
336 static const int npindex_to_ethertype[NUM_NP] = {
337 ETH_P_IP,
338 ETH_P_IPV6,
339 ETH_P_IPX,
340 ETH_P_PPPTALK,
341 ETH_P_MPLS_UC,
342 ETH_P_MPLS_MC,
343 };
344
345 /*
346 * Locking shorthand.
347 */
348 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
349 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
350 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
351 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
352 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
353 ppp_recv_lock(ppp); } while (0)
354 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
355 ppp_xmit_unlock(ppp); } while (0)
356
357 /*
358 * /dev/ppp device routines.
359 * The /dev/ppp device is used by pppd to control the ppp unit.
360 * It supports the read, write, ioctl and poll functions.
361 * Open instances of /dev/ppp can be in one of three states:
362 * unattached, attached to a ppp unit, or attached to a ppp channel.
363 */
364 static int ppp_open(struct inode *inode, struct file *file)
365 {
366 cycle_kernel_lock();
367 /*
368 * This could (should?) be enforced by the permissions on /dev/ppp.
369 */
370 if (!capable(CAP_NET_ADMIN))
371 return -EPERM;
372 return 0;
373 }
374
375 static int ppp_release(struct inode *unused, struct file *file)
376 {
377 struct ppp_file *pf = file->private_data;
378 struct ppp *ppp;
379
380 if (pf) {
381 file->private_data = NULL;
382 if (pf->kind == INTERFACE) {
383 ppp = PF_TO_PPP(pf);
384 if (file == ppp->owner)
385 ppp_shutdown_interface(ppp);
386 }
387 if (atomic_dec_and_test(&pf->refcnt)) {
388 switch (pf->kind) {
389 case INTERFACE:
390 ppp_destroy_interface(PF_TO_PPP(pf));
391 break;
392 case CHANNEL:
393 ppp_destroy_channel(PF_TO_CHANNEL(pf));
394 break;
395 }
396 }
397 }
398 return 0;
399 }
400
401 static ssize_t ppp_read(struct file *file, char __user *buf,
402 size_t count, loff_t *ppos)
403 {
404 struct ppp_file *pf = file->private_data;
405 DECLARE_WAITQUEUE(wait, current);
406 ssize_t ret;
407 struct sk_buff *skb = NULL;
408 struct iovec iov;
409
410 ret = count;
411
412 if (!pf)
413 return -ENXIO;
414 add_wait_queue(&pf->rwait, &wait);
415 for (;;) {
416 set_current_state(TASK_INTERRUPTIBLE);
417 skb = skb_dequeue(&pf->rq);
418 if (skb)
419 break;
420 ret = 0;
421 if (pf->dead)
422 break;
423 if (pf->kind == INTERFACE) {
424 /*
425 * Return 0 (EOF) on an interface that has no
426 * channels connected, unless it is looping
427 * network traffic (demand mode).
428 */
429 struct ppp *ppp = PF_TO_PPP(pf);
430 if (ppp->n_channels == 0 &&
431 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
432 break;
433 }
434 ret = -EAGAIN;
435 if (file->f_flags & O_NONBLOCK)
436 break;
437 ret = -ERESTARTSYS;
438 if (signal_pending(current))
439 break;
440 schedule();
441 }
442 set_current_state(TASK_RUNNING);
443 remove_wait_queue(&pf->rwait, &wait);
444
445 if (!skb)
446 goto out;
447
448 ret = -EOVERFLOW;
449 if (skb->len > count)
450 goto outf;
451 ret = -EFAULT;
452 iov.iov_base = buf;
453 iov.iov_len = count;
454 if (skb_copy_datagram_iovec(skb, 0, &iov, skb->len))
455 goto outf;
456 ret = skb->len;
457
458 outf:
459 kfree_skb(skb);
460 out:
461 return ret;
462 }
463
464 static ssize_t ppp_write(struct file *file, const char __user *buf,
465 size_t count, loff_t *ppos)
466 {
467 struct ppp_file *pf = file->private_data;
468 struct sk_buff *skb;
469 ssize_t ret;
470
471 if (!pf)
472 return -ENXIO;
473 ret = -ENOMEM;
474 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
475 if (!skb)
476 goto out;
477 skb_reserve(skb, pf->hdrlen);
478 ret = -EFAULT;
479 if (copy_from_user(skb_put(skb, count), buf, count)) {
480 kfree_skb(skb);
481 goto out;
482 }
483
484 skb_queue_tail(&pf->xq, skb);
485
486 switch (pf->kind) {
487 case INTERFACE:
488 ppp_xmit_process(PF_TO_PPP(pf));
489 break;
490 case CHANNEL:
491 ppp_channel_push(PF_TO_CHANNEL(pf));
492 break;
493 }
494
495 ret = count;
496
497 out:
498 return ret;
499 }
500
501 /* No kernel lock - fine */
502 static unsigned int ppp_poll(struct file *file, poll_table *wait)
503 {
504 struct ppp_file *pf = file->private_data;
505 unsigned int mask;
506
507 if (!pf)
508 return 0;
509 poll_wait(file, &pf->rwait, wait);
510 mask = POLLOUT | POLLWRNORM;
511 if (skb_peek(&pf->rq))
512 mask |= POLLIN | POLLRDNORM;
513 if (pf->dead)
514 mask |= POLLHUP;
515 else if (pf->kind == INTERFACE) {
516 /* see comment in ppp_read */
517 struct ppp *ppp = PF_TO_PPP(pf);
518 if (ppp->n_channels == 0 &&
519 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
520 mask |= POLLIN | POLLRDNORM;
521 }
522
523 return mask;
524 }
525
526 #ifdef CONFIG_PPP_FILTER
527 static int get_filter(void __user *arg, struct sock_filter **p)
528 {
529 struct sock_fprog uprog;
530 struct sock_filter *code = NULL;
531 int len, err;
532
533 if (copy_from_user(&uprog, arg, sizeof(uprog)))
534 return -EFAULT;
535
536 if (!uprog.len) {
537 *p = NULL;
538 return 0;
539 }
540
541 len = uprog.len * sizeof(struct sock_filter);
542 code = kmalloc(len, GFP_KERNEL);
543 if (code == NULL)
544 return -ENOMEM;
545
546 if (copy_from_user(code, uprog.filter, len)) {
547 kfree(code);
548 return -EFAULT;
549 }
550
551 err = sk_chk_filter(code, uprog.len);
552 if (err) {
553 kfree(code);
554 return err;
555 }
556
557 *p = code;
558 return uprog.len;
559 }
560 #endif /* CONFIG_PPP_FILTER */
561
562 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
563 {
564 struct ppp_file *pf = file->private_data;
565 struct ppp *ppp;
566 int err = -EFAULT, val, val2, i;
567 struct ppp_idle idle;
568 struct npioctl npi;
569 int unit, cflags;
570 struct slcompress *vj;
571 void __user *argp = (void __user *)arg;
572 int __user *p = argp;
573
574 if (!pf)
575 return ppp_unattached_ioctl(current->nsproxy->net_ns,
576 pf, file, cmd, arg);
577
578 if (cmd == PPPIOCDETACH) {
579 /*
580 * We have to be careful here... if the file descriptor
581 * has been dup'd, we could have another process in the
582 * middle of a poll using the same file *, so we had
583 * better not free the interface data structures -
584 * instead we fail the ioctl. Even in this case, we
585 * shut down the interface if we are the owner of it.
586 * Actually, we should get rid of PPPIOCDETACH, userland
587 * (i.e. pppd) could achieve the same effect by closing
588 * this fd and reopening /dev/ppp.
589 */
590 err = -EINVAL;
591 lock_kernel();
592 if (pf->kind == INTERFACE) {
593 ppp = PF_TO_PPP(pf);
594 if (file == ppp->owner)
595 ppp_shutdown_interface(ppp);
596 }
597 if (atomic_long_read(&file->f_count) <= 2) {
598 ppp_release(NULL, file);
599 err = 0;
600 } else
601 printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%ld\n",
602 atomic_long_read(&file->f_count));
603 unlock_kernel();
604 return err;
605 }
606
607 if (pf->kind == CHANNEL) {
608 struct channel *pch;
609 struct ppp_channel *chan;
610
611 lock_kernel();
612 pch = PF_TO_CHANNEL(pf);
613
614 switch (cmd) {
615 case PPPIOCCONNECT:
616 if (get_user(unit, p))
617 break;
618 err = ppp_connect_channel(pch, unit);
619 break;
620
621 case PPPIOCDISCONN:
622 err = ppp_disconnect_channel(pch);
623 break;
624
625 default:
626 down_read(&pch->chan_sem);
627 chan = pch->chan;
628 err = -ENOTTY;
629 if (chan && chan->ops->ioctl)
630 err = chan->ops->ioctl(chan, cmd, arg);
631 up_read(&pch->chan_sem);
632 }
633 unlock_kernel();
634 return err;
635 }
636
637 if (pf->kind != INTERFACE) {
638 /* can't happen */
639 printk(KERN_ERR "PPP: not interface or channel??\n");
640 return -EINVAL;
641 }
642
643 lock_kernel();
644 ppp = PF_TO_PPP(pf);
645 switch (cmd) {
646 case PPPIOCSMRU:
647 if (get_user(val, p))
648 break;
649 ppp->mru = val;
650 err = 0;
651 break;
652
653 case PPPIOCSFLAGS:
654 if (get_user(val, p))
655 break;
656 ppp_lock(ppp);
657 cflags = ppp->flags & ~val;
658 ppp->flags = val & SC_FLAG_BITS;
659 ppp_unlock(ppp);
660 if (cflags & SC_CCP_OPEN)
661 ppp_ccp_closed(ppp);
662 err = 0;
663 break;
664
665 case PPPIOCGFLAGS:
666 val = ppp->flags | ppp->xstate | ppp->rstate;
667 if (put_user(val, p))
668 break;
669 err = 0;
670 break;
671
672 case PPPIOCSCOMPRESS:
673 err = ppp_set_compress(ppp, arg);
674 break;
675
676 case PPPIOCGUNIT:
677 if (put_user(ppp->file.index, p))
678 break;
679 err = 0;
680 break;
681
682 case PPPIOCSDEBUG:
683 if (get_user(val, p))
684 break;
685 ppp->debug = val;
686 err = 0;
687 break;
688
689 case PPPIOCGDEBUG:
690 if (put_user(ppp->debug, p))
691 break;
692 err = 0;
693 break;
694
695 case PPPIOCGIDLE:
696 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
697 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
698 if (copy_to_user(argp, &idle, sizeof(idle)))
699 break;
700 err = 0;
701 break;
702
703 case PPPIOCSMAXCID:
704 if (get_user(val, p))
705 break;
706 val2 = 15;
707 if ((val >> 16) != 0) {
708 val2 = val >> 16;
709 val &= 0xffff;
710 }
711 vj = slhc_init(val2+1, val+1);
712 if (!vj) {
713 printk(KERN_ERR "PPP: no memory (VJ compressor)\n");
714 err = -ENOMEM;
715 break;
716 }
717 ppp_lock(ppp);
718 if (ppp->vj)
719 slhc_free(ppp->vj);
720 ppp->vj = vj;
721 ppp_unlock(ppp);
722 err = 0;
723 break;
724
725 case PPPIOCGNPMODE:
726 case PPPIOCSNPMODE:
727 if (copy_from_user(&npi, argp, sizeof(npi)))
728 break;
729 err = proto_to_npindex(npi.protocol);
730 if (err < 0)
731 break;
732 i = err;
733 if (cmd == PPPIOCGNPMODE) {
734 err = -EFAULT;
735 npi.mode = ppp->npmode[i];
736 if (copy_to_user(argp, &npi, sizeof(npi)))
737 break;
738 } else {
739 ppp->npmode[i] = npi.mode;
740 /* we may be able to transmit more packets now (??) */
741 netif_wake_queue(ppp->dev);
742 }
743 err = 0;
744 break;
745
746 #ifdef CONFIG_PPP_FILTER
747 case PPPIOCSPASS:
748 {
749 struct sock_filter *code;
750 err = get_filter(argp, &code);
751 if (err >= 0) {
752 ppp_lock(ppp);
753 kfree(ppp->pass_filter);
754 ppp->pass_filter = code;
755 ppp->pass_len = err;
756 ppp_unlock(ppp);
757 err = 0;
758 }
759 break;
760 }
761 case PPPIOCSACTIVE:
762 {
763 struct sock_filter *code;
764 err = get_filter(argp, &code);
765 if (err >= 0) {
766 ppp_lock(ppp);
767 kfree(ppp->active_filter);
768 ppp->active_filter = code;
769 ppp->active_len = err;
770 ppp_unlock(ppp);
771 err = 0;
772 }
773 break;
774 }
775 #endif /* CONFIG_PPP_FILTER */
776
777 #ifdef CONFIG_PPP_MULTILINK
778 case PPPIOCSMRRU:
779 if (get_user(val, p))
780 break;
781 ppp_recv_lock(ppp);
782 ppp->mrru = val;
783 ppp_recv_unlock(ppp);
784 err = 0;
785 break;
786 #endif /* CONFIG_PPP_MULTILINK */
787
788 default:
789 err = -ENOTTY;
790 }
791 unlock_kernel();
792 return err;
793 }
794
795 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
796 struct file *file, unsigned int cmd, unsigned long arg)
797 {
798 int unit, err = -EFAULT;
799 struct ppp *ppp;
800 struct channel *chan;
801 struct ppp_net *pn;
802 int __user *p = (int __user *)arg;
803
804 lock_kernel();
805 switch (cmd) {
806 case PPPIOCNEWUNIT:
807 /* Create a new ppp unit */
808 if (get_user(unit, p))
809 break;
810 ppp = ppp_create_interface(net, unit, &err);
811 if (!ppp)
812 break;
813 file->private_data = &ppp->file;
814 ppp->owner = file;
815 err = -EFAULT;
816 if (put_user(ppp->file.index, p))
817 break;
818 err = 0;
819 break;
820
821 case PPPIOCATTACH:
822 /* Attach to an existing ppp unit */
823 if (get_user(unit, p))
824 break;
825 err = -ENXIO;
826 pn = ppp_pernet(net);
827 mutex_lock(&pn->all_ppp_mutex);
828 ppp = ppp_find_unit(pn, unit);
829 if (ppp) {
830 atomic_inc(&ppp->file.refcnt);
831 file->private_data = &ppp->file;
832 err = 0;
833 }
834 mutex_unlock(&pn->all_ppp_mutex);
835 break;
836
837 case PPPIOCATTCHAN:
838 if (get_user(unit, p))
839 break;
840 err = -ENXIO;
841 pn = ppp_pernet(net);
842 spin_lock_bh(&pn->all_channels_lock);
843 chan = ppp_find_channel(pn, unit);
844 if (chan) {
845 atomic_inc(&chan->file.refcnt);
846 file->private_data = &chan->file;
847 err = 0;
848 }
849 spin_unlock_bh(&pn->all_channels_lock);
850 break;
851
852 default:
853 err = -ENOTTY;
854 }
855 unlock_kernel();
856 return err;
857 }
858
859 static const struct file_operations ppp_device_fops = {
860 .owner = THIS_MODULE,
861 .read = ppp_read,
862 .write = ppp_write,
863 .poll = ppp_poll,
864 .unlocked_ioctl = ppp_ioctl,
865 .open = ppp_open,
866 .release = ppp_release
867 };
868
869 static __net_init int ppp_init_net(struct net *net)
870 {
871 struct ppp_net *pn = net_generic(net, ppp_net_id);
872
873 idr_init(&pn->units_idr);
874 mutex_init(&pn->all_ppp_mutex);
875
876 INIT_LIST_HEAD(&pn->all_channels);
877 INIT_LIST_HEAD(&pn->new_channels);
878
879 spin_lock_init(&pn->all_channels_lock);
880
881 return 0;
882 }
883
884 static __net_exit void ppp_exit_net(struct net *net)
885 {
886 struct ppp_net *pn = net_generic(net, ppp_net_id);
887
888 idr_destroy(&pn->units_idr);
889 }
890
891 static struct pernet_operations ppp_net_ops = {
892 .init = ppp_init_net,
893 .exit = ppp_exit_net,
894 .id = &ppp_net_id,
895 .size = sizeof(struct ppp_net),
896 };
897
898 #define PPP_MAJOR 108
899
900 /* Called at boot time if ppp is compiled into the kernel,
901 or at module load time (from init_module) if compiled as a module. */
902 static int __init ppp_init(void)
903 {
904 int err;
905
906 printk(KERN_INFO "PPP generic driver version " PPP_VERSION "\n");
907
908 err = register_pernet_device(&ppp_net_ops);
909 if (err) {
910 printk(KERN_ERR "failed to register PPP pernet device (%d)\n", err);
911 goto out;
912 }
913
914 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
915 if (err) {
916 printk(KERN_ERR "failed to register PPP device (%d)\n", err);
917 goto out_net;
918 }
919
920 ppp_class = class_create(THIS_MODULE, "ppp");
921 if (IS_ERR(ppp_class)) {
922 err = PTR_ERR(ppp_class);
923 goto out_chrdev;
924 }
925
926 /* not a big deal if we fail here :-) */
927 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
928
929 return 0;
930
931 out_chrdev:
932 unregister_chrdev(PPP_MAJOR, "ppp");
933 out_net:
934 unregister_pernet_device(&ppp_net_ops);
935 out:
936 return err;
937 }
938
939 /*
940 * Network interface unit routines.
941 */
942 static netdev_tx_t
943 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
944 {
945 struct ppp *ppp = netdev_priv(dev);
946 int npi, proto;
947 unsigned char *pp;
948
949 npi = ethertype_to_npindex(ntohs(skb->protocol));
950 if (npi < 0)
951 goto outf;
952
953 /* Drop, accept or reject the packet */
954 switch (ppp->npmode[npi]) {
955 case NPMODE_PASS:
956 break;
957 case NPMODE_QUEUE:
958 /* it would be nice to have a way to tell the network
959 system to queue this one up for later. */
960 goto outf;
961 case NPMODE_DROP:
962 case NPMODE_ERROR:
963 goto outf;
964 }
965
966 /* Put the 2-byte PPP protocol number on the front,
967 making sure there is room for the address and control fields. */
968 if (skb_cow_head(skb, PPP_HDRLEN))
969 goto outf;
970
971 pp = skb_push(skb, 2);
972 proto = npindex_to_proto[npi];
973 pp[0] = proto >> 8;
974 pp[1] = proto;
975
976 netif_stop_queue(dev);
977 skb_queue_tail(&ppp->file.xq, skb);
978 ppp_xmit_process(ppp);
979 return NETDEV_TX_OK;
980
981 outf:
982 kfree_skb(skb);
983 ++dev->stats.tx_dropped;
984 return NETDEV_TX_OK;
985 }
986
987 static int
988 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
989 {
990 struct ppp *ppp = netdev_priv(dev);
991 int err = -EFAULT;
992 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
993 struct ppp_stats stats;
994 struct ppp_comp_stats cstats;
995 char *vers;
996
997 switch (cmd) {
998 case SIOCGPPPSTATS:
999 ppp_get_stats(ppp, &stats);
1000 if (copy_to_user(addr, &stats, sizeof(stats)))
1001 break;
1002 err = 0;
1003 break;
1004
1005 case SIOCGPPPCSTATS:
1006 memset(&cstats, 0, sizeof(cstats));
1007 if (ppp->xc_state)
1008 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
1009 if (ppp->rc_state)
1010 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
1011 if (copy_to_user(addr, &cstats, sizeof(cstats)))
1012 break;
1013 err = 0;
1014 break;
1015
1016 case SIOCGPPPVER:
1017 vers = PPP_VERSION;
1018 if (copy_to_user(addr, vers, strlen(vers) + 1))
1019 break;
1020 err = 0;
1021 break;
1022
1023 default:
1024 err = -EINVAL;
1025 }
1026
1027 return err;
1028 }
1029
1030 static const struct net_device_ops ppp_netdev_ops = {
1031 .ndo_start_xmit = ppp_start_xmit,
1032 .ndo_do_ioctl = ppp_net_ioctl,
1033 };
1034
1035 static void ppp_setup(struct net_device *dev)
1036 {
1037 dev->netdev_ops = &ppp_netdev_ops;
1038 dev->hard_header_len = PPP_HDRLEN;
1039 dev->mtu = PPP_MTU;
1040 dev->addr_len = 0;
1041 dev->tx_queue_len = 3;
1042 dev->type = ARPHRD_PPP;
1043 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1044 dev->features |= NETIF_F_NETNS_LOCAL;
1045 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1046 }
1047
1048 /*
1049 * Transmit-side routines.
1050 */
1051
1052 /*
1053 * Called to do any work queued up on the transmit side
1054 * that can now be done.
1055 */
1056 static void
1057 ppp_xmit_process(struct ppp *ppp)
1058 {
1059 struct sk_buff *skb;
1060
1061 ppp_xmit_lock(ppp);
1062 if (!ppp->closing) {
1063 ppp_push(ppp);
1064 while (!ppp->xmit_pending &&
1065 (skb = skb_dequeue(&ppp->file.xq)))
1066 ppp_send_frame(ppp, skb);
1067 /* If there's no work left to do, tell the core net
1068 code that we can accept some more. */
1069 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1070 netif_wake_queue(ppp->dev);
1071 }
1072 ppp_xmit_unlock(ppp);
1073 }
1074
1075 static inline struct sk_buff *
1076 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1077 {
1078 struct sk_buff *new_skb;
1079 int len;
1080 int new_skb_size = ppp->dev->mtu +
1081 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1082 int compressor_skb_size = ppp->dev->mtu +
1083 ppp->xcomp->comp_extra + PPP_HDRLEN;
1084 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1085 if (!new_skb) {
1086 if (net_ratelimit())
1087 printk(KERN_ERR "PPP: no memory (comp pkt)\n");
1088 return NULL;
1089 }
1090 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1091 skb_reserve(new_skb,
1092 ppp->dev->hard_header_len - PPP_HDRLEN);
1093
1094 /* compressor still expects A/C bytes in hdr */
1095 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1096 new_skb->data, skb->len + 2,
1097 compressor_skb_size);
1098 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1099 kfree_skb(skb);
1100 skb = new_skb;
1101 skb_put(skb, len);
1102 skb_pull(skb, 2); /* pull off A/C bytes */
1103 } else if (len == 0) {
1104 /* didn't compress, or CCP not up yet */
1105 kfree_skb(new_skb);
1106 new_skb = skb;
1107 } else {
1108 /*
1109 * (len < 0)
1110 * MPPE requires that we do not send unencrypted
1111 * frames. The compressor will return -1 if we
1112 * should drop the frame. We cannot simply test
1113 * the compress_proto because MPPE and MPPC share
1114 * the same number.
1115 */
1116 if (net_ratelimit())
1117 printk(KERN_ERR "ppp: compressor dropped pkt\n");
1118 kfree_skb(skb);
1119 kfree_skb(new_skb);
1120 new_skb = NULL;
1121 }
1122 return new_skb;
1123 }
1124
1125 /*
1126 * Compress and send a frame.
1127 * The caller should have locked the xmit path,
1128 * and xmit_pending should be 0.
1129 */
1130 static void
1131 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1132 {
1133 int proto = PPP_PROTO(skb);
1134 struct sk_buff *new_skb;
1135 int len;
1136 unsigned char *cp;
1137
1138 if (proto < 0x8000) {
1139 #ifdef CONFIG_PPP_FILTER
1140 /* check if we should pass this packet */
1141 /* the filter instructions are constructed assuming
1142 a four-byte PPP header on each packet */
1143 *skb_push(skb, 2) = 1;
1144 if (ppp->pass_filter &&
1145 sk_run_filter(skb, ppp->pass_filter,
1146 ppp->pass_len) == 0) {
1147 if (ppp->debug & 1)
1148 printk(KERN_DEBUG "PPP: outbound frame not passed\n");
1149 kfree_skb(skb);
1150 return;
1151 }
1152 /* if this packet passes the active filter, record the time */
1153 if (!(ppp->active_filter &&
1154 sk_run_filter(skb, ppp->active_filter,
1155 ppp->active_len) == 0))
1156 ppp->last_xmit = jiffies;
1157 skb_pull(skb, 2);
1158 #else
1159 /* for data packets, record the time */
1160 ppp->last_xmit = jiffies;
1161 #endif /* CONFIG_PPP_FILTER */
1162 }
1163
1164 ++ppp->dev->stats.tx_packets;
1165 ppp->dev->stats.tx_bytes += skb->len - 2;
1166
1167 switch (proto) {
1168 case PPP_IP:
1169 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1170 break;
1171 /* try to do VJ TCP header compression */
1172 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1173 GFP_ATOMIC);
1174 if (!new_skb) {
1175 printk(KERN_ERR "PPP: no memory (VJ comp pkt)\n");
1176 goto drop;
1177 }
1178 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1179 cp = skb->data + 2;
1180 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1181 new_skb->data + 2, &cp,
1182 !(ppp->flags & SC_NO_TCP_CCID));
1183 if (cp == skb->data + 2) {
1184 /* didn't compress */
1185 kfree_skb(new_skb);
1186 } else {
1187 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1188 proto = PPP_VJC_COMP;
1189 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1190 } else {
1191 proto = PPP_VJC_UNCOMP;
1192 cp[0] = skb->data[2];
1193 }
1194 kfree_skb(skb);
1195 skb = new_skb;
1196 cp = skb_put(skb, len + 2);
1197 cp[0] = 0;
1198 cp[1] = proto;
1199 }
1200 break;
1201
1202 case PPP_CCP:
1203 /* peek at outbound CCP frames */
1204 ppp_ccp_peek(ppp, skb, 0);
1205 break;
1206 }
1207
1208 /* try to do packet compression */
1209 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state &&
1210 proto != PPP_LCP && proto != PPP_CCP) {
1211 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1212 if (net_ratelimit())
1213 printk(KERN_ERR "ppp: compression required but down - pkt dropped.\n");
1214 goto drop;
1215 }
1216 skb = pad_compress_skb(ppp, skb);
1217 if (!skb)
1218 goto drop;
1219 }
1220
1221 /*
1222 * If we are waiting for traffic (demand dialling),
1223 * queue it up for pppd to receive.
1224 */
1225 if (ppp->flags & SC_LOOP_TRAFFIC) {
1226 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1227 goto drop;
1228 skb_queue_tail(&ppp->file.rq, skb);
1229 wake_up_interruptible(&ppp->file.rwait);
1230 return;
1231 }
1232
1233 ppp->xmit_pending = skb;
1234 ppp_push(ppp);
1235 return;
1236
1237 drop:
1238 kfree_skb(skb);
1239 ++ppp->dev->stats.tx_errors;
1240 }
1241
1242 /*
1243 * Try to send the frame in xmit_pending.
1244 * The caller should have the xmit path locked.
1245 */
1246 static void
1247 ppp_push(struct ppp *ppp)
1248 {
1249 struct list_head *list;
1250 struct channel *pch;
1251 struct sk_buff *skb = ppp->xmit_pending;
1252
1253 if (!skb)
1254 return;
1255
1256 list = &ppp->channels;
1257 if (list_empty(list)) {
1258 /* nowhere to send the packet, just drop it */
1259 ppp->xmit_pending = NULL;
1260 kfree_skb(skb);
1261 return;
1262 }
1263
1264 if ((ppp->flags & SC_MULTILINK) == 0) {
1265 /* not doing multilink: send it down the first channel */
1266 list = list->next;
1267 pch = list_entry(list, struct channel, clist);
1268
1269 spin_lock_bh(&pch->downl);
1270 if (pch->chan) {
1271 if (pch->chan->ops->start_xmit(pch->chan, skb))
1272 ppp->xmit_pending = NULL;
1273 } else {
1274 /* channel got unregistered */
1275 kfree_skb(skb);
1276 ppp->xmit_pending = NULL;
1277 }
1278 spin_unlock_bh(&pch->downl);
1279 return;
1280 }
1281
1282 #ifdef CONFIG_PPP_MULTILINK
1283 /* Multilink: fragment the packet over as many links
1284 as can take the packet at the moment. */
1285 if (!ppp_mp_explode(ppp, skb))
1286 return;
1287 #endif /* CONFIG_PPP_MULTILINK */
1288
1289 ppp->xmit_pending = NULL;
1290 kfree_skb(skb);
1291 }
1292
1293 #ifdef CONFIG_PPP_MULTILINK
1294 /*
1295 * Divide a packet to be transmitted into fragments and
1296 * send them out the individual links.
1297 */
1298 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1299 {
1300 int len, totlen;
1301 int i, bits, hdrlen, mtu;
1302 int flen;
1303 int navail, nfree, nzero;
1304 int nbigger;
1305 int totspeed;
1306 int totfree;
1307 unsigned char *p, *q;
1308 struct list_head *list;
1309 struct channel *pch;
1310 struct sk_buff *frag;
1311 struct ppp_channel *chan;
1312
1313 totspeed = 0; /*total bitrate of the bundle*/
1314 nfree = 0; /* # channels which have no packet already queued */
1315 navail = 0; /* total # of usable channels (not deregistered) */
1316 nzero = 0; /* number of channels with zero speed associated*/
1317 totfree = 0; /*total # of channels available and
1318 *having no queued packets before
1319 *starting the fragmentation*/
1320
1321 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1322 i = 0;
1323 list_for_each_entry(pch, &ppp->channels, clist) {
1324 navail += pch->avail = (pch->chan != NULL);
1325 pch->speed = pch->chan->speed;
1326 if (pch->avail) {
1327 if (skb_queue_empty(&pch->file.xq) ||
1328 !pch->had_frag) {
1329 if (pch->speed == 0)
1330 nzero++;
1331 else
1332 totspeed += pch->speed;
1333
1334 pch->avail = 2;
1335 ++nfree;
1336 ++totfree;
1337 }
1338 if (!pch->had_frag && i < ppp->nxchan)
1339 ppp->nxchan = i;
1340 }
1341 ++i;
1342 }
1343 /*
1344 * Don't start sending this packet unless at least half of
1345 * the channels are free. This gives much better TCP
1346 * performance if we have a lot of channels.
1347 */
1348 if (nfree == 0 || nfree < navail / 2)
1349 return 0; /* can't take now, leave it in xmit_pending */
1350
1351 /* Do protocol field compression (XXX this should be optional) */
1352 p = skb->data;
1353 len = skb->len;
1354 if (*p == 0) {
1355 ++p;
1356 --len;
1357 }
1358
1359 totlen = len;
1360 nbigger = len % nfree;
1361
1362 /* skip to the channel after the one we last used
1363 and start at that one */
1364 list = &ppp->channels;
1365 for (i = 0; i < ppp->nxchan; ++i) {
1366 list = list->next;
1367 if (list == &ppp->channels) {
1368 i = 0;
1369 break;
1370 }
1371 }
1372
1373 /* create a fragment for each channel */
1374 bits = B;
1375 while (len > 0) {
1376 list = list->next;
1377 if (list == &ppp->channels) {
1378 i = 0;
1379 continue;
1380 }
1381 pch = list_entry(list, struct channel, clist);
1382 ++i;
1383 if (!pch->avail)
1384 continue;
1385
1386 /*
1387 * Skip this channel if it has a fragment pending already and
1388 * we haven't given a fragment to all of the free channels.
1389 */
1390 if (pch->avail == 1) {
1391 if (nfree > 0)
1392 continue;
1393 } else {
1394 pch->avail = 1;
1395 }
1396
1397 /* check the channel's mtu and whether it is still attached. */
1398 spin_lock_bh(&pch->downl);
1399 if (pch->chan == NULL) {
1400 /* can't use this channel, it's being deregistered */
1401 if (pch->speed == 0)
1402 nzero--;
1403 else
1404 totspeed -= pch->speed;
1405
1406 spin_unlock_bh(&pch->downl);
1407 pch->avail = 0;
1408 totlen = len;
1409 totfree--;
1410 nfree--;
1411 if (--navail == 0)
1412 break;
1413 continue;
1414 }
1415
1416 /*
1417 *if the channel speed is not set divide
1418 *the packet evenly among the free channels;
1419 *otherwise divide it according to the speed
1420 *of the channel we are going to transmit on
1421 */
1422 flen = len;
1423 if (nfree > 0) {
1424 if (pch->speed == 0) {
1425 flen = len/nfree;
1426 if (nbigger > 0) {
1427 flen++;
1428 nbigger--;
1429 }
1430 } else {
1431 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
1432 ((totspeed*totfree)/pch->speed)) - hdrlen;
1433 if (nbigger > 0) {
1434 flen += ((totfree - nzero)*pch->speed)/totspeed;
1435 nbigger -= ((totfree - nzero)*pch->speed)/
1436 totspeed;
1437 }
1438 }
1439 nfree--;
1440 }
1441
1442 /*
1443 *check if we are on the last channel or
1444 *we exceded the lenght of the data to
1445 *fragment
1446 */
1447 if ((nfree <= 0) || (flen > len))
1448 flen = len;
1449 /*
1450 *it is not worth to tx on slow channels:
1451 *in that case from the resulting flen according to the
1452 *above formula will be equal or less than zero.
1453 *Skip the channel in this case
1454 */
1455 if (flen <= 0) {
1456 pch->avail = 2;
1457 spin_unlock_bh(&pch->downl);
1458 continue;
1459 }
1460
1461 mtu = pch->chan->mtu - hdrlen;
1462 if (mtu < 4)
1463 mtu = 4;
1464 if (flen > mtu)
1465 flen = mtu;
1466 if (flen == len)
1467 bits |= E;
1468 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1469 if (!frag)
1470 goto noskb;
1471 q = skb_put(frag, flen + hdrlen);
1472
1473 /* make the MP header */
1474 q[0] = PPP_MP >> 8;
1475 q[1] = PPP_MP;
1476 if (ppp->flags & SC_MP_XSHORTSEQ) {
1477 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1478 q[3] = ppp->nxseq;
1479 } else {
1480 q[2] = bits;
1481 q[3] = ppp->nxseq >> 16;
1482 q[4] = ppp->nxseq >> 8;
1483 q[5] = ppp->nxseq;
1484 }
1485
1486 memcpy(q + hdrlen, p, flen);
1487
1488 /* try to send it down the channel */
1489 chan = pch->chan;
1490 if (!skb_queue_empty(&pch->file.xq) ||
1491 !chan->ops->start_xmit(chan, frag))
1492 skb_queue_tail(&pch->file.xq, frag);
1493 pch->had_frag = 1;
1494 p += flen;
1495 len -= flen;
1496 ++ppp->nxseq;
1497 bits = 0;
1498 spin_unlock_bh(&pch->downl);
1499 }
1500 ppp->nxchan = i;
1501
1502 return 1;
1503
1504 noskb:
1505 spin_unlock_bh(&pch->downl);
1506 if (ppp->debug & 1)
1507 printk(KERN_ERR "PPP: no memory (fragment)\n");
1508 ++ppp->dev->stats.tx_errors;
1509 ++ppp->nxseq;
1510 return 1; /* abandon the frame */
1511 }
1512 #endif /* CONFIG_PPP_MULTILINK */
1513
1514 /*
1515 * Try to send data out on a channel.
1516 */
1517 static void
1518 ppp_channel_push(struct channel *pch)
1519 {
1520 struct sk_buff *skb;
1521 struct ppp *ppp;
1522
1523 spin_lock_bh(&pch->downl);
1524 if (pch->chan) {
1525 while (!skb_queue_empty(&pch->file.xq)) {
1526 skb = skb_dequeue(&pch->file.xq);
1527 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1528 /* put the packet back and try again later */
1529 skb_queue_head(&pch->file.xq, skb);
1530 break;
1531 }
1532 }
1533 } else {
1534 /* channel got deregistered */
1535 skb_queue_purge(&pch->file.xq);
1536 }
1537 spin_unlock_bh(&pch->downl);
1538 /* see if there is anything from the attached unit to be sent */
1539 if (skb_queue_empty(&pch->file.xq)) {
1540 read_lock_bh(&pch->upl);
1541 ppp = pch->ppp;
1542 if (ppp)
1543 ppp_xmit_process(ppp);
1544 read_unlock_bh(&pch->upl);
1545 }
1546 }
1547
1548 /*
1549 * Receive-side routines.
1550 */
1551
1552 /* misuse a few fields of the skb for MP reconstruction */
1553 #define sequence priority
1554 #define BEbits cb[0]
1555
1556 static inline void
1557 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1558 {
1559 ppp_recv_lock(ppp);
1560 if (!ppp->closing)
1561 ppp_receive_frame(ppp, skb, pch);
1562 else
1563 kfree_skb(skb);
1564 ppp_recv_unlock(ppp);
1565 }
1566
1567 void
1568 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1569 {
1570 struct channel *pch = chan->ppp;
1571 int proto;
1572
1573 if (!pch) {
1574 kfree_skb(skb);
1575 return;
1576 }
1577
1578 read_lock_bh(&pch->upl);
1579 if (!pskb_may_pull(skb, 2)) {
1580 kfree_skb(skb);
1581 if (pch->ppp) {
1582 ++pch->ppp->dev->stats.rx_length_errors;
1583 ppp_receive_error(pch->ppp);
1584 }
1585 goto done;
1586 }
1587
1588 proto = PPP_PROTO(skb);
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
1601 done:
1602 read_unlock_bh(&pch->upl);
1603 }
1604
1605 /* Put a 0-length skb in the receive queue as an error indication */
1606 void
1607 ppp_input_error(struct ppp_channel *chan, int code)
1608 {
1609 struct channel *pch = chan->ppp;
1610 struct sk_buff *skb;
1611
1612 if (!pch)
1613 return;
1614
1615 read_lock_bh(&pch->upl);
1616 if (pch->ppp) {
1617 skb = alloc_skb(0, GFP_ATOMIC);
1618 if (skb) {
1619 skb->len = 0; /* probably unnecessary */
1620 skb->cb[0] = code;
1621 ppp_do_recv(pch->ppp, skb, pch);
1622 }
1623 }
1624 read_unlock_bh(&pch->upl);
1625 }
1626
1627 /*
1628 * We come in here to process a received frame.
1629 * The receive side of the ppp unit is locked.
1630 */
1631 static void
1632 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1633 {
1634 /* note: a 0-length skb is used as an error indication */
1635 if (skb->len > 0) {
1636 #ifdef CONFIG_PPP_MULTILINK
1637 /* XXX do channel-level decompression here */
1638 if (PPP_PROTO(skb) == PPP_MP)
1639 ppp_receive_mp_frame(ppp, skb, pch);
1640 else
1641 #endif /* CONFIG_PPP_MULTILINK */
1642 ppp_receive_nonmp_frame(ppp, skb);
1643 } else {
1644 kfree_skb(skb);
1645 ppp_receive_error(ppp);
1646 }
1647 }
1648
1649 static void
1650 ppp_receive_error(struct ppp *ppp)
1651 {
1652 ++ppp->dev->stats.rx_errors;
1653 if (ppp->vj)
1654 slhc_toss(ppp->vj);
1655 }
1656
1657 static void
1658 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1659 {
1660 struct sk_buff *ns;
1661 int proto, len, npi;
1662
1663 /*
1664 * Decompress the frame, if compressed.
1665 * Note that some decompressors need to see uncompressed frames
1666 * that come in as well as compressed frames.
1667 */
1668 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) &&
1669 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1670 skb = ppp_decompress_frame(ppp, skb);
1671
1672 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1673 goto err;
1674
1675 proto = PPP_PROTO(skb);
1676 switch (proto) {
1677 case PPP_VJC_COMP:
1678 /* decompress VJ compressed packets */
1679 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1680 goto err;
1681
1682 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1683 /* copy to a new sk_buff with more tailroom */
1684 ns = dev_alloc_skb(skb->len + 128);
1685 if (!ns) {
1686 printk(KERN_ERR"PPP: no memory (VJ decomp)\n");
1687 goto err;
1688 }
1689 skb_reserve(ns, 2);
1690 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1691 kfree_skb(skb);
1692 skb = ns;
1693 }
1694 else
1695 skb->ip_summed = CHECKSUM_NONE;
1696
1697 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1698 if (len <= 0) {
1699 printk(KERN_DEBUG "PPP: VJ decompression error\n");
1700 goto err;
1701 }
1702 len += 2;
1703 if (len > skb->len)
1704 skb_put(skb, len - skb->len);
1705 else if (len < skb->len)
1706 skb_trim(skb, len);
1707 proto = PPP_IP;
1708 break;
1709
1710 case PPP_VJC_UNCOMP:
1711 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1712 goto err;
1713
1714 /* Until we fix the decompressor need to make sure
1715 * data portion is linear.
1716 */
1717 if (!pskb_may_pull(skb, skb->len))
1718 goto err;
1719
1720 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1721 printk(KERN_ERR "PPP: VJ uncompressed error\n");
1722 goto err;
1723 }
1724 proto = PPP_IP;
1725 break;
1726
1727 case PPP_CCP:
1728 ppp_ccp_peek(ppp, skb, 1);
1729 break;
1730 }
1731
1732 ++ppp->dev->stats.rx_packets;
1733 ppp->dev->stats.rx_bytes += skb->len - 2;
1734
1735 npi = proto_to_npindex(proto);
1736 if (npi < 0) {
1737 /* control or unknown frame - pass it to pppd */
1738 skb_queue_tail(&ppp->file.rq, skb);
1739 /* limit queue length by dropping old frames */
1740 while (ppp->file.rq.qlen > PPP_MAX_RQLEN &&
1741 (skb = skb_dequeue(&ppp->file.rq)))
1742 kfree_skb(skb);
1743 /* wake up any process polling or blocking on read */
1744 wake_up_interruptible(&ppp->file.rwait);
1745
1746 } else {
1747 /* network protocol frame - give it to the kernel */
1748
1749 #ifdef CONFIG_PPP_FILTER
1750 /* check if the packet passes the pass and active filters */
1751 /* the filter instructions are constructed assuming
1752 a four-byte PPP header on each packet */
1753 if (ppp->pass_filter || ppp->active_filter) {
1754 if (skb_cloned(skb) &&
1755 pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
1756 goto err;
1757
1758 *skb_push(skb, 2) = 0;
1759 if (ppp->pass_filter &&
1760 sk_run_filter(skb, ppp->pass_filter,
1761 ppp->pass_len) == 0) {
1762 if (ppp->debug & 1)
1763 printk(KERN_DEBUG "PPP: inbound frame "
1764 "not passed\n");
1765 kfree_skb(skb);
1766 return;
1767 }
1768 if (!(ppp->active_filter &&
1769 sk_run_filter(skb, ppp->active_filter,
1770 ppp->active_len) == 0))
1771 ppp->last_recv = jiffies;
1772 __skb_pull(skb, 2);
1773 } else
1774 #endif /* CONFIG_PPP_FILTER */
1775 ppp->last_recv = jiffies;
1776
1777 if ((ppp->dev->flags & IFF_UP) == 0 ||
1778 ppp->npmode[npi] != NPMODE_PASS) {
1779 kfree_skb(skb);
1780 } else {
1781 /* chop off protocol */
1782 skb_pull_rcsum(skb, 2);
1783 skb->dev = ppp->dev;
1784 skb->protocol = htons(npindex_to_ethertype[npi]);
1785 skb_reset_mac_header(skb);
1786 netif_rx(skb);
1787 }
1788 }
1789 return;
1790
1791 err:
1792 kfree_skb(skb);
1793 ppp_receive_error(ppp);
1794 }
1795
1796 static struct sk_buff *
1797 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1798 {
1799 int proto = PPP_PROTO(skb);
1800 struct sk_buff *ns;
1801 int len;
1802
1803 /* Until we fix all the decompressor's need to make sure
1804 * data portion is linear.
1805 */
1806 if (!pskb_may_pull(skb, skb->len))
1807 goto err;
1808
1809 if (proto == PPP_COMP) {
1810 int obuff_size;
1811
1812 switch(ppp->rcomp->compress_proto) {
1813 case CI_MPPE:
1814 obuff_size = ppp->mru + PPP_HDRLEN + 1;
1815 break;
1816 default:
1817 obuff_size = ppp->mru + PPP_HDRLEN;
1818 break;
1819 }
1820
1821 ns = dev_alloc_skb(obuff_size);
1822 if (!ns) {
1823 printk(KERN_ERR "ppp_decompress_frame: no memory\n");
1824 goto err;
1825 }
1826 /* the decompressor still expects the A/C bytes in the hdr */
1827 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1828 skb->len + 2, ns->data, obuff_size);
1829 if (len < 0) {
1830 /* Pass the compressed frame to pppd as an
1831 error indication. */
1832 if (len == DECOMP_FATALERROR)
1833 ppp->rstate |= SC_DC_FERROR;
1834 kfree_skb(ns);
1835 goto err;
1836 }
1837
1838 kfree_skb(skb);
1839 skb = ns;
1840 skb_put(skb, len);
1841 skb_pull(skb, 2); /* pull off the A/C bytes */
1842
1843 } else {
1844 /* Uncompressed frame - pass to decompressor so it
1845 can update its dictionary if necessary. */
1846 if (ppp->rcomp->incomp)
1847 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1848 skb->len + 2);
1849 }
1850
1851 return skb;
1852
1853 err:
1854 ppp->rstate |= SC_DC_ERROR;
1855 ppp_receive_error(ppp);
1856 return skb;
1857 }
1858
1859 #ifdef CONFIG_PPP_MULTILINK
1860 /*
1861 * Receive a multilink frame.
1862 * We put it on the reconstruction queue and then pull off
1863 * as many completed frames as we can.
1864 */
1865 static void
1866 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1867 {
1868 u32 mask, seq;
1869 struct channel *ch;
1870 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1871
1872 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
1873 goto err; /* no good, throw it away */
1874
1875 /* Decode sequence number and begin/end bits */
1876 if (ppp->flags & SC_MP_SHORTSEQ) {
1877 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1878 mask = 0xfff;
1879 } else {
1880 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1881 mask = 0xffffff;
1882 }
1883 skb->BEbits = skb->data[2];
1884 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
1885
1886 /*
1887 * Do protocol ID decompression on the first fragment of each packet.
1888 */
1889 if ((skb->BEbits & B) && (skb->data[0] & 1))
1890 *skb_push(skb, 1) = 0;
1891
1892 /*
1893 * Expand sequence number to 32 bits, making it as close
1894 * as possible to ppp->minseq.
1895 */
1896 seq |= ppp->minseq & ~mask;
1897 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
1898 seq += mask + 1;
1899 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
1900 seq -= mask + 1; /* should never happen */
1901 skb->sequence = seq;
1902 pch->lastseq = seq;
1903
1904 /*
1905 * If this packet comes before the next one we were expecting,
1906 * drop it.
1907 */
1908 if (seq_before(seq, ppp->nextseq)) {
1909 kfree_skb(skb);
1910 ++ppp->dev->stats.rx_dropped;
1911 ppp_receive_error(ppp);
1912 return;
1913 }
1914
1915 /*
1916 * Reevaluate minseq, the minimum over all channels of the
1917 * last sequence number received on each channel. Because of
1918 * the increasing sequence number rule, we know that any fragment
1919 * before `minseq' which hasn't arrived is never going to arrive.
1920 * The list of channels can't change because we have the receive
1921 * side of the ppp unit locked.
1922 */
1923 list_for_each_entry(ch, &ppp->channels, clist) {
1924 if (seq_before(ch->lastseq, seq))
1925 seq = ch->lastseq;
1926 }
1927 if (seq_before(ppp->minseq, seq))
1928 ppp->minseq = seq;
1929
1930 /* Put the fragment on the reconstruction queue */
1931 ppp_mp_insert(ppp, skb);
1932
1933 /* If the queue is getting long, don't wait any longer for packets
1934 before the start of the queue. */
1935 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
1936 struct sk_buff *skb = skb_peek(&ppp->mrq);
1937 if (seq_before(ppp->minseq, skb->sequence))
1938 ppp->minseq = skb->sequence;
1939 }
1940
1941 /* Pull completed packets off the queue and receive them. */
1942 while ((skb = ppp_mp_reconstruct(ppp))) {
1943 if (pskb_may_pull(skb, 2))
1944 ppp_receive_nonmp_frame(ppp, skb);
1945 else {
1946 ++ppp->dev->stats.rx_length_errors;
1947 kfree_skb(skb);
1948 ppp_receive_error(ppp);
1949 }
1950 }
1951
1952 return;
1953
1954 err:
1955 kfree_skb(skb);
1956 ppp_receive_error(ppp);
1957 }
1958
1959 /*
1960 * Insert a fragment on the MP reconstruction queue.
1961 * The queue is ordered by increasing sequence number.
1962 */
1963 static void
1964 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
1965 {
1966 struct sk_buff *p;
1967 struct sk_buff_head *list = &ppp->mrq;
1968 u32 seq = skb->sequence;
1969
1970 /* N.B. we don't need to lock the list lock because we have the
1971 ppp unit receive-side lock. */
1972 skb_queue_walk(list, p) {
1973 if (seq_before(seq, p->sequence))
1974 break;
1975 }
1976 __skb_queue_before(list, p, skb);
1977 }
1978
1979 /*
1980 * Reconstruct a packet from the MP fragment queue.
1981 * We go through increasing sequence numbers until we find a
1982 * complete packet, or we get to the sequence number for a fragment
1983 * which hasn't arrived but might still do so.
1984 */
1985 static struct sk_buff *
1986 ppp_mp_reconstruct(struct ppp *ppp)
1987 {
1988 u32 seq = ppp->nextseq;
1989 u32 minseq = ppp->minseq;
1990 struct sk_buff_head *list = &ppp->mrq;
1991 struct sk_buff *p, *next;
1992 struct sk_buff *head, *tail;
1993 struct sk_buff *skb = NULL;
1994 int lost = 0, len = 0;
1995
1996 if (ppp->mrru == 0) /* do nothing until mrru is set */
1997 return NULL;
1998 head = list->next;
1999 tail = NULL;
2000 for (p = head; p != (struct sk_buff *) list; p = next) {
2001 next = p->next;
2002 if (seq_before(p->sequence, seq)) {
2003 /* this can't happen, anyway ignore the skb */
2004 printk(KERN_ERR "ppp_mp_reconstruct bad seq %u < %u\n",
2005 p->sequence, seq);
2006 head = next;
2007 continue;
2008 }
2009 if (p->sequence != seq) {
2010 /* Fragment `seq' is missing. If it is after
2011 minseq, it might arrive later, so stop here. */
2012 if (seq_after(seq, minseq))
2013 break;
2014 /* Fragment `seq' is lost, keep going. */
2015 lost = 1;
2016 seq = seq_before(minseq, p->sequence)?
2017 minseq + 1: p->sequence;
2018 next = p;
2019 continue;
2020 }
2021
2022 /*
2023 * At this point we know that all the fragments from
2024 * ppp->nextseq to seq are either present or lost.
2025 * Also, there are no complete packets in the queue
2026 * that have no missing fragments and end before this
2027 * fragment.
2028 */
2029
2030 /* B bit set indicates this fragment starts a packet */
2031 if (p->BEbits & B) {
2032 head = p;
2033 lost = 0;
2034 len = 0;
2035 }
2036
2037 len += p->len;
2038
2039 /* Got a complete packet yet? */
2040 if (lost == 0 && (p->BEbits & E) && (head->BEbits & B)) {
2041 if (len > ppp->mrru + 2) {
2042 ++ppp->dev->stats.rx_length_errors;
2043 printk(KERN_DEBUG "PPP: reconstructed packet"
2044 " is too long (%d)\n", len);
2045 } else if (p == head) {
2046 /* fragment is complete packet - reuse skb */
2047 tail = p;
2048 skb = skb_get(p);
2049 break;
2050 } else if ((skb = dev_alloc_skb(len)) == NULL) {
2051 ++ppp->dev->stats.rx_missed_errors;
2052 printk(KERN_DEBUG "PPP: no memory for "
2053 "reconstructed packet");
2054 } else {
2055 tail = p;
2056 break;
2057 }
2058 ppp->nextseq = seq + 1;
2059 }
2060
2061 /*
2062 * If this is the ending fragment of a packet,
2063 * and we haven't found a complete valid packet yet,
2064 * we can discard up to and including this fragment.
2065 */
2066 if (p->BEbits & E)
2067 head = next;
2068
2069 ++seq;
2070 }
2071
2072 /* If we have a complete packet, copy it all into one skb. */
2073 if (tail != NULL) {
2074 /* If we have discarded any fragments,
2075 signal a receive error. */
2076 if (head->sequence != ppp->nextseq) {
2077 if (ppp->debug & 1)
2078 printk(KERN_DEBUG " missed pkts %u..%u\n",
2079 ppp->nextseq, head->sequence-1);
2080 ++ppp->dev->stats.rx_dropped;
2081 ppp_receive_error(ppp);
2082 }
2083
2084 if (head != tail)
2085 /* copy to a single skb */
2086 for (p = head; p != tail->next; p = p->next)
2087 skb_copy_bits(p, 0, skb_put(skb, p->len), p->len);
2088 ppp->nextseq = tail->sequence + 1;
2089 head = tail->next;
2090 }
2091
2092 /* Discard all the skbuffs that we have copied the data out of
2093 or that we can't use. */
2094 while ((p = list->next) != head) {
2095 __skb_unlink(p, list);
2096 kfree_skb(p);
2097 }
2098
2099 return skb;
2100 }
2101 #endif /* CONFIG_PPP_MULTILINK */
2102
2103 /*
2104 * Channel interface.
2105 */
2106
2107 /* Create a new, unattached ppp channel. */
2108 int ppp_register_channel(struct ppp_channel *chan)
2109 {
2110 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2111 }
2112
2113 /* Create a new, unattached ppp channel for specified net. */
2114 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
2115 {
2116 struct channel *pch;
2117 struct ppp_net *pn;
2118
2119 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2120 if (!pch)
2121 return -ENOMEM;
2122
2123 pn = ppp_pernet(net);
2124
2125 pch->ppp = NULL;
2126 pch->chan = chan;
2127 pch->chan_net = net;
2128 chan->ppp = pch;
2129 init_ppp_file(&pch->file, CHANNEL);
2130 pch->file.hdrlen = chan->hdrlen;
2131 #ifdef CONFIG_PPP_MULTILINK
2132 pch->lastseq = -1;
2133 #endif /* CONFIG_PPP_MULTILINK */
2134 init_rwsem(&pch->chan_sem);
2135 spin_lock_init(&pch->downl);
2136 rwlock_init(&pch->upl);
2137
2138 spin_lock_bh(&pn->all_channels_lock);
2139 pch->file.index = ++pn->last_channel_index;
2140 list_add(&pch->list, &pn->new_channels);
2141 atomic_inc(&channel_count);
2142 spin_unlock_bh(&pn->all_channels_lock);
2143
2144 return 0;
2145 }
2146
2147 /*
2148 * Return the index of a channel.
2149 */
2150 int ppp_channel_index(struct ppp_channel *chan)
2151 {
2152 struct channel *pch = chan->ppp;
2153
2154 if (pch)
2155 return pch->file.index;
2156 return -1;
2157 }
2158
2159 /*
2160 * Return the PPP unit number to which a channel is connected.
2161 */
2162 int ppp_unit_number(struct ppp_channel *chan)
2163 {
2164 struct channel *pch = chan->ppp;
2165 int unit = -1;
2166
2167 if (pch) {
2168 read_lock_bh(&pch->upl);
2169 if (pch->ppp)
2170 unit = pch->ppp->file.index;
2171 read_unlock_bh(&pch->upl);
2172 }
2173 return unit;
2174 }
2175
2176 /*
2177 * Return the PPP device interface name of a channel.
2178 */
2179 char *ppp_dev_name(struct ppp_channel *chan)
2180 {
2181 struct channel *pch = chan->ppp;
2182 char *name = NULL;
2183
2184 if (pch) {
2185 read_lock_bh(&pch->upl);
2186 if (pch->ppp && pch->ppp->dev)
2187 name = pch->ppp->dev->name;
2188 read_unlock_bh(&pch->upl);
2189 }
2190 return name;
2191 }
2192
2193
2194 /*
2195 * Disconnect a channel from the generic layer.
2196 * This must be called in process context.
2197 */
2198 void
2199 ppp_unregister_channel(struct ppp_channel *chan)
2200 {
2201 struct channel *pch = chan->ppp;
2202 struct ppp_net *pn;
2203
2204 if (!pch)
2205 return; /* should never happen */
2206
2207 chan->ppp = NULL;
2208
2209 /*
2210 * This ensures that we have returned from any calls into the
2211 * the channel's start_xmit or ioctl routine before we proceed.
2212 */
2213 down_write(&pch->chan_sem);
2214 spin_lock_bh(&pch->downl);
2215 pch->chan = NULL;
2216 spin_unlock_bh(&pch->downl);
2217 up_write(&pch->chan_sem);
2218 ppp_disconnect_channel(pch);
2219
2220 pn = ppp_pernet(pch->chan_net);
2221 spin_lock_bh(&pn->all_channels_lock);
2222 list_del(&pch->list);
2223 spin_unlock_bh(&pn->all_channels_lock);
2224
2225 pch->file.dead = 1;
2226 wake_up_interruptible(&pch->file.rwait);
2227 if (atomic_dec_and_test(&pch->file.refcnt))
2228 ppp_destroy_channel(pch);
2229 }
2230
2231 /*
2232 * Callback from a channel when it can accept more to transmit.
2233 * This should be called at BH/softirq level, not interrupt level.
2234 */
2235 void
2236 ppp_output_wakeup(struct ppp_channel *chan)
2237 {
2238 struct channel *pch = chan->ppp;
2239
2240 if (!pch)
2241 return;
2242 ppp_channel_push(pch);
2243 }
2244
2245 /*
2246 * Compression control.
2247 */
2248
2249 /* Process the PPPIOCSCOMPRESS ioctl. */
2250 static int
2251 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2252 {
2253 int err;
2254 struct compressor *cp, *ocomp;
2255 struct ppp_option_data data;
2256 void *state, *ostate;
2257 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2258
2259 err = -EFAULT;
2260 if (copy_from_user(&data, (void __user *) arg, sizeof(data)) ||
2261 (data.length <= CCP_MAX_OPTION_LENGTH &&
2262 copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2263 goto out;
2264 err = -EINVAL;
2265 if (data.length > CCP_MAX_OPTION_LENGTH ||
2266 ccp_option[1] < 2 || ccp_option[1] > data.length)
2267 goto out;
2268
2269 cp = try_then_request_module(
2270 find_compressor(ccp_option[0]),
2271 "ppp-compress-%d", ccp_option[0]);
2272 if (!cp)
2273 goto out;
2274
2275 err = -ENOBUFS;
2276 if (data.transmit) {
2277 state = cp->comp_alloc(ccp_option, data.length);
2278 if (state) {
2279 ppp_xmit_lock(ppp);
2280 ppp->xstate &= ~SC_COMP_RUN;
2281 ocomp = ppp->xcomp;
2282 ostate = ppp->xc_state;
2283 ppp->xcomp = cp;
2284 ppp->xc_state = state;
2285 ppp_xmit_unlock(ppp);
2286 if (ostate) {
2287 ocomp->comp_free(ostate);
2288 module_put(ocomp->owner);
2289 }
2290 err = 0;
2291 } else
2292 module_put(cp->owner);
2293
2294 } else {
2295 state = cp->decomp_alloc(ccp_option, data.length);
2296 if (state) {
2297 ppp_recv_lock(ppp);
2298 ppp->rstate &= ~SC_DECOMP_RUN;
2299 ocomp = ppp->rcomp;
2300 ostate = ppp->rc_state;
2301 ppp->rcomp = cp;
2302 ppp->rc_state = state;
2303 ppp_recv_unlock(ppp);
2304 if (ostate) {
2305 ocomp->decomp_free(ostate);
2306 module_put(ocomp->owner);
2307 }
2308 err = 0;
2309 } else
2310 module_put(cp->owner);
2311 }
2312
2313 out:
2314 return err;
2315 }
2316
2317 /*
2318 * Look at a CCP packet and update our state accordingly.
2319 * We assume the caller has the xmit or recv path locked.
2320 */
2321 static void
2322 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2323 {
2324 unsigned char *dp;
2325 int len;
2326
2327 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2328 return; /* no header */
2329 dp = skb->data + 2;
2330
2331 switch (CCP_CODE(dp)) {
2332 case CCP_CONFREQ:
2333
2334 /* A ConfReq starts negotiation of compression
2335 * in one direction of transmission,
2336 * and hence brings it down...but which way?
2337 *
2338 * Remember:
2339 * A ConfReq indicates what the sender would like to receive
2340 */
2341 if(inbound)
2342 /* He is proposing what I should send */
2343 ppp->xstate &= ~SC_COMP_RUN;
2344 else
2345 /* I am proposing to what he should send */
2346 ppp->rstate &= ~SC_DECOMP_RUN;
2347
2348 break;
2349
2350 case CCP_TERMREQ:
2351 case CCP_TERMACK:
2352 /*
2353 * CCP is going down, both directions of transmission
2354 */
2355 ppp->rstate &= ~SC_DECOMP_RUN;
2356 ppp->xstate &= ~SC_COMP_RUN;
2357 break;
2358
2359 case CCP_CONFACK:
2360 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2361 break;
2362 len = CCP_LENGTH(dp);
2363 if (!pskb_may_pull(skb, len + 2))
2364 return; /* too short */
2365 dp += CCP_HDRLEN;
2366 len -= CCP_HDRLEN;
2367 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2368 break;
2369 if (inbound) {
2370 /* we will start receiving compressed packets */
2371 if (!ppp->rc_state)
2372 break;
2373 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2374 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2375 ppp->rstate |= SC_DECOMP_RUN;
2376 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2377 }
2378 } else {
2379 /* we will soon start sending compressed packets */
2380 if (!ppp->xc_state)
2381 break;
2382 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2383 ppp->file.index, 0, ppp->debug))
2384 ppp->xstate |= SC_COMP_RUN;
2385 }
2386 break;
2387
2388 case CCP_RESETACK:
2389 /* reset the [de]compressor */
2390 if ((ppp->flags & SC_CCP_UP) == 0)
2391 break;
2392 if (inbound) {
2393 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2394 ppp->rcomp->decomp_reset(ppp->rc_state);
2395 ppp->rstate &= ~SC_DC_ERROR;
2396 }
2397 } else {
2398 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2399 ppp->xcomp->comp_reset(ppp->xc_state);
2400 }
2401 break;
2402 }
2403 }
2404
2405 /* Free up compression resources. */
2406 static void
2407 ppp_ccp_closed(struct ppp *ppp)
2408 {
2409 void *xstate, *rstate;
2410 struct compressor *xcomp, *rcomp;
2411
2412 ppp_lock(ppp);
2413 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2414 ppp->xstate = 0;
2415 xcomp = ppp->xcomp;
2416 xstate = ppp->xc_state;
2417 ppp->xc_state = NULL;
2418 ppp->rstate = 0;
2419 rcomp = ppp->rcomp;
2420 rstate = ppp->rc_state;
2421 ppp->rc_state = NULL;
2422 ppp_unlock(ppp);
2423
2424 if (xstate) {
2425 xcomp->comp_free(xstate);
2426 module_put(xcomp->owner);
2427 }
2428 if (rstate) {
2429 rcomp->decomp_free(rstate);
2430 module_put(rcomp->owner);
2431 }
2432 }
2433
2434 /* List of compressors. */
2435 static LIST_HEAD(compressor_list);
2436 static DEFINE_SPINLOCK(compressor_list_lock);
2437
2438 struct compressor_entry {
2439 struct list_head list;
2440 struct compressor *comp;
2441 };
2442
2443 static struct compressor_entry *
2444 find_comp_entry(int proto)
2445 {
2446 struct compressor_entry *ce;
2447
2448 list_for_each_entry(ce, &compressor_list, list) {
2449 if (ce->comp->compress_proto == proto)
2450 return ce;
2451 }
2452 return NULL;
2453 }
2454
2455 /* Register a compressor */
2456 int
2457 ppp_register_compressor(struct compressor *cp)
2458 {
2459 struct compressor_entry *ce;
2460 int ret;
2461 spin_lock(&compressor_list_lock);
2462 ret = -EEXIST;
2463 if (find_comp_entry(cp->compress_proto))
2464 goto out;
2465 ret = -ENOMEM;
2466 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2467 if (!ce)
2468 goto out;
2469 ret = 0;
2470 ce->comp = cp;
2471 list_add(&ce->list, &compressor_list);
2472 out:
2473 spin_unlock(&compressor_list_lock);
2474 return ret;
2475 }
2476
2477 /* Unregister a compressor */
2478 void
2479 ppp_unregister_compressor(struct compressor *cp)
2480 {
2481 struct compressor_entry *ce;
2482
2483 spin_lock(&compressor_list_lock);
2484 ce = find_comp_entry(cp->compress_proto);
2485 if (ce && ce->comp == cp) {
2486 list_del(&ce->list);
2487 kfree(ce);
2488 }
2489 spin_unlock(&compressor_list_lock);
2490 }
2491
2492 /* Find a compressor. */
2493 static struct compressor *
2494 find_compressor(int type)
2495 {
2496 struct compressor_entry *ce;
2497 struct compressor *cp = NULL;
2498
2499 spin_lock(&compressor_list_lock);
2500 ce = find_comp_entry(type);
2501 if (ce) {
2502 cp = ce->comp;
2503 if (!try_module_get(cp->owner))
2504 cp = NULL;
2505 }
2506 spin_unlock(&compressor_list_lock);
2507 return cp;
2508 }
2509
2510 /*
2511 * Miscelleneous stuff.
2512 */
2513
2514 static void
2515 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2516 {
2517 struct slcompress *vj = ppp->vj;
2518
2519 memset(st, 0, sizeof(*st));
2520 st->p.ppp_ipackets = ppp->dev->stats.rx_packets;
2521 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2522 st->p.ppp_ibytes = ppp->dev->stats.rx_bytes;
2523 st->p.ppp_opackets = ppp->dev->stats.tx_packets;
2524 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2525 st->p.ppp_obytes = ppp->dev->stats.tx_bytes;
2526 if (!vj)
2527 return;
2528 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2529 st->vj.vjs_compressed = vj->sls_o_compressed;
2530 st->vj.vjs_searches = vj->sls_o_searches;
2531 st->vj.vjs_misses = vj->sls_o_misses;
2532 st->vj.vjs_errorin = vj->sls_i_error;
2533 st->vj.vjs_tossed = vj->sls_i_tossed;
2534 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2535 st->vj.vjs_compressedin = vj->sls_i_compressed;
2536 }
2537
2538 /*
2539 * Stuff for handling the lists of ppp units and channels
2540 * and for initialization.
2541 */
2542
2543 /*
2544 * Create a new ppp interface unit. Fails if it can't allocate memory
2545 * or if there is already a unit with the requested number.
2546 * unit == -1 means allocate a new number.
2547 */
2548 static struct ppp *
2549 ppp_create_interface(struct net *net, int unit, int *retp)
2550 {
2551 struct ppp *ppp;
2552 struct ppp_net *pn;
2553 struct net_device *dev = NULL;
2554 int ret = -ENOMEM;
2555 int i;
2556
2557 dev = alloc_netdev(sizeof(struct ppp), "", ppp_setup);
2558 if (!dev)
2559 goto out1;
2560
2561 pn = ppp_pernet(net);
2562
2563 ppp = netdev_priv(dev);
2564 ppp->dev = dev;
2565 ppp->mru = PPP_MRU;
2566 init_ppp_file(&ppp->file, INTERFACE);
2567 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2568 for (i = 0; i < NUM_NP; ++i)
2569 ppp->npmode[i] = NPMODE_PASS;
2570 INIT_LIST_HEAD(&ppp->channels);
2571 spin_lock_init(&ppp->rlock);
2572 spin_lock_init(&ppp->wlock);
2573 #ifdef CONFIG_PPP_MULTILINK
2574 ppp->minseq = -1;
2575 skb_queue_head_init(&ppp->mrq);
2576 #endif /* CONFIG_PPP_MULTILINK */
2577
2578 /*
2579 * drum roll: don't forget to set
2580 * the net device is belong to
2581 */
2582 dev_net_set(dev, net);
2583
2584 ret = -EEXIST;
2585 mutex_lock(&pn->all_ppp_mutex);
2586
2587 if (unit < 0) {
2588 unit = unit_get(&pn->units_idr, ppp);
2589 if (unit < 0) {
2590 *retp = unit;
2591 goto out2;
2592 }
2593 } else {
2594 if (unit_find(&pn->units_idr, unit))
2595 goto out2; /* unit already exists */
2596 /*
2597 * if caller need a specified unit number
2598 * lets try to satisfy him, otherwise --
2599 * he should better ask us for new unit number
2600 *
2601 * NOTE: yes I know that returning EEXIST it's not
2602 * fair but at least pppd will ask us to allocate
2603 * new unit in this case so user is happy :)
2604 */
2605 unit = unit_set(&pn->units_idr, ppp, unit);
2606 if (unit < 0)
2607 goto out2;
2608 }
2609
2610 /* Initialize the new ppp unit */
2611 ppp->file.index = unit;
2612 sprintf(dev->name, "ppp%d", unit);
2613
2614 ret = register_netdev(dev);
2615 if (ret != 0) {
2616 unit_put(&pn->units_idr, unit);
2617 printk(KERN_ERR "PPP: couldn't register device %s (%d)\n",
2618 dev->name, ret);
2619 goto out2;
2620 }
2621
2622 ppp->ppp_net = net;
2623
2624 atomic_inc(&ppp_unit_count);
2625 mutex_unlock(&pn->all_ppp_mutex);
2626
2627 *retp = 0;
2628 return ppp;
2629
2630 out2:
2631 mutex_unlock(&pn->all_ppp_mutex);
2632 free_netdev(dev);
2633 out1:
2634 *retp = ret;
2635 return NULL;
2636 }
2637
2638 /*
2639 * Initialize a ppp_file structure.
2640 */
2641 static void
2642 init_ppp_file(struct ppp_file *pf, int kind)
2643 {
2644 pf->kind = kind;
2645 skb_queue_head_init(&pf->xq);
2646 skb_queue_head_init(&pf->rq);
2647 atomic_set(&pf->refcnt, 1);
2648 init_waitqueue_head(&pf->rwait);
2649 }
2650
2651 /*
2652 * Take down a ppp interface unit - called when the owning file
2653 * (the one that created the unit) is closed or detached.
2654 */
2655 static void ppp_shutdown_interface(struct ppp *ppp)
2656 {
2657 struct ppp_net *pn;
2658
2659 pn = ppp_pernet(ppp->ppp_net);
2660 mutex_lock(&pn->all_ppp_mutex);
2661
2662 /* This will call dev_close() for us. */
2663 ppp_lock(ppp);
2664 if (!ppp->closing) {
2665 ppp->closing = 1;
2666 ppp_unlock(ppp);
2667 unregister_netdev(ppp->dev);
2668 } else
2669 ppp_unlock(ppp);
2670
2671 unit_put(&pn->units_idr, ppp->file.index);
2672 ppp->file.dead = 1;
2673 ppp->owner = NULL;
2674 wake_up_interruptible(&ppp->file.rwait);
2675
2676 mutex_unlock(&pn->all_ppp_mutex);
2677 }
2678
2679 /*
2680 * Free the memory used by a ppp unit. This is only called once
2681 * there are no channels connected to the unit and no file structs
2682 * that reference the unit.
2683 */
2684 static void ppp_destroy_interface(struct ppp *ppp)
2685 {
2686 atomic_dec(&ppp_unit_count);
2687
2688 if (!ppp->file.dead || ppp->n_channels) {
2689 /* "can't happen" */
2690 printk(KERN_ERR "ppp: destroying ppp struct %p but dead=%d "
2691 "n_channels=%d !\n", ppp, ppp->file.dead,
2692 ppp->n_channels);
2693 return;
2694 }
2695
2696 ppp_ccp_closed(ppp);
2697 if (ppp->vj) {
2698 slhc_free(ppp->vj);
2699 ppp->vj = NULL;
2700 }
2701 skb_queue_purge(&ppp->file.xq);
2702 skb_queue_purge(&ppp->file.rq);
2703 #ifdef CONFIG_PPP_MULTILINK
2704 skb_queue_purge(&ppp->mrq);
2705 #endif /* CONFIG_PPP_MULTILINK */
2706 #ifdef CONFIG_PPP_FILTER
2707 kfree(ppp->pass_filter);
2708 ppp->pass_filter = NULL;
2709 kfree(ppp->active_filter);
2710 ppp->active_filter = NULL;
2711 #endif /* CONFIG_PPP_FILTER */
2712
2713 kfree_skb(ppp->xmit_pending);
2714
2715 free_netdev(ppp->dev);
2716 }
2717
2718 /*
2719 * Locate an existing ppp unit.
2720 * The caller should have locked the all_ppp_mutex.
2721 */
2722 static struct ppp *
2723 ppp_find_unit(struct ppp_net *pn, int unit)
2724 {
2725 return unit_find(&pn->units_idr, unit);
2726 }
2727
2728 /*
2729 * Locate an existing ppp channel.
2730 * The caller should have locked the all_channels_lock.
2731 * First we look in the new_channels list, then in the
2732 * all_channels list. If found in the new_channels list,
2733 * we move it to the all_channels list. This is for speed
2734 * when we have a lot of channels in use.
2735 */
2736 static struct channel *
2737 ppp_find_channel(struct ppp_net *pn, int unit)
2738 {
2739 struct channel *pch;
2740
2741 list_for_each_entry(pch, &pn->new_channels, list) {
2742 if (pch->file.index == unit) {
2743 list_move(&pch->list, &pn->all_channels);
2744 return pch;
2745 }
2746 }
2747
2748 list_for_each_entry(pch, &pn->all_channels, list) {
2749 if (pch->file.index == unit)
2750 return pch;
2751 }
2752
2753 return NULL;
2754 }
2755
2756 /*
2757 * Connect a PPP channel to a PPP interface unit.
2758 */
2759 static int
2760 ppp_connect_channel(struct channel *pch, int unit)
2761 {
2762 struct ppp *ppp;
2763 struct ppp_net *pn;
2764 int ret = -ENXIO;
2765 int hdrlen;
2766
2767 pn = ppp_pernet(pch->chan_net);
2768
2769 mutex_lock(&pn->all_ppp_mutex);
2770 ppp = ppp_find_unit(pn, unit);
2771 if (!ppp)
2772 goto out;
2773 write_lock_bh(&pch->upl);
2774 ret = -EINVAL;
2775 if (pch->ppp)
2776 goto outl;
2777
2778 ppp_lock(ppp);
2779 if (pch->file.hdrlen > ppp->file.hdrlen)
2780 ppp->file.hdrlen = pch->file.hdrlen;
2781 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2782 if (hdrlen > ppp->dev->hard_header_len)
2783 ppp->dev->hard_header_len = hdrlen;
2784 list_add_tail(&pch->clist, &ppp->channels);
2785 ++ppp->n_channels;
2786 pch->ppp = ppp;
2787 atomic_inc(&ppp->file.refcnt);
2788 ppp_unlock(ppp);
2789 ret = 0;
2790
2791 outl:
2792 write_unlock_bh(&pch->upl);
2793 out:
2794 mutex_unlock(&pn->all_ppp_mutex);
2795 return ret;
2796 }
2797
2798 /*
2799 * Disconnect a channel from its ppp unit.
2800 */
2801 static int
2802 ppp_disconnect_channel(struct channel *pch)
2803 {
2804 struct ppp *ppp;
2805 int err = -EINVAL;
2806
2807 write_lock_bh(&pch->upl);
2808 ppp = pch->ppp;
2809 pch->ppp = NULL;
2810 write_unlock_bh(&pch->upl);
2811 if (ppp) {
2812 /* remove it from the ppp unit's list */
2813 ppp_lock(ppp);
2814 list_del(&pch->clist);
2815 if (--ppp->n_channels == 0)
2816 wake_up_interruptible(&ppp->file.rwait);
2817 ppp_unlock(ppp);
2818 if (atomic_dec_and_test(&ppp->file.refcnt))
2819 ppp_destroy_interface(ppp);
2820 err = 0;
2821 }
2822 return err;
2823 }
2824
2825 /*
2826 * Free up the resources used by a ppp channel.
2827 */
2828 static void ppp_destroy_channel(struct channel *pch)
2829 {
2830 atomic_dec(&channel_count);
2831
2832 if (!pch->file.dead) {
2833 /* "can't happen" */
2834 printk(KERN_ERR "ppp: destroying undead channel %p !\n",
2835 pch);
2836 return;
2837 }
2838 skb_queue_purge(&pch->file.xq);
2839 skb_queue_purge(&pch->file.rq);
2840 kfree(pch);
2841 }
2842
2843 static void __exit ppp_cleanup(void)
2844 {
2845 /* should never happen */
2846 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2847 printk(KERN_ERR "PPP: removing module but units remain!\n");
2848 unregister_chrdev(PPP_MAJOR, "ppp");
2849 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
2850 class_destroy(ppp_class);
2851 unregister_pernet_device(&ppp_net_ops);
2852 }
2853
2854 /*
2855 * Units handling. Caller must protect concurrent access
2856 * by holding all_ppp_mutex
2857 */
2858
2859 /* associate pointer with specified number */
2860 static int unit_set(struct idr *p, void *ptr, int n)
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, n, &unit);
2871 if (err == -EAGAIN)
2872 goto again;
2873
2874 if (unit != n) {
2875 idr_remove(p, unit);
2876 return -EINVAL;
2877 }
2878
2879 return unit;
2880 }
2881
2882 /* get new free unit number and associate pointer with it */
2883 static int unit_get(struct idr *p, void *ptr)
2884 {
2885 int unit, err;
2886
2887 again:
2888 if (!idr_pre_get(p, GFP_KERNEL)) {
2889 printk(KERN_ERR "PPP: No free memory for idr\n");
2890 return -ENOMEM;
2891 }
2892
2893 err = idr_get_new_above(p, ptr, 0, &unit);
2894 if (err == -EAGAIN)
2895 goto again;
2896
2897 return unit;
2898 }
2899
2900 /* put unit number back to a pool */
2901 static void unit_put(struct idr *p, int n)
2902 {
2903 idr_remove(p, n);
2904 }
2905
2906 /* get pointer associated with the number */
2907 static void *unit_find(struct idr *p, int n)
2908 {
2909 return idr_find(p, n);
2910 }
2911
2912 /* Module/initialization stuff */
2913
2914 module_init(ppp_init);
2915 module_exit(ppp_cleanup);
2916
2917 EXPORT_SYMBOL(ppp_register_net_channel);
2918 EXPORT_SYMBOL(ppp_register_channel);
2919 EXPORT_SYMBOL(ppp_unregister_channel);
2920 EXPORT_SYMBOL(ppp_channel_index);
2921 EXPORT_SYMBOL(ppp_unit_number);
2922 EXPORT_SYMBOL(ppp_dev_name);
2923 EXPORT_SYMBOL(ppp_input);
2924 EXPORT_SYMBOL(ppp_input_error);
2925 EXPORT_SYMBOL(ppp_output_wakeup);
2926 EXPORT_SYMBOL(ppp_register_compressor);
2927 EXPORT_SYMBOL(ppp_unregister_compressor);
2928 MODULE_LICENSE("GPL");
2929 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
2930 MODULE_ALIAS("devname:ppp");
Linux with added FPC-III support