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Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux...
[linux/fpc-iii.git] / drivers / net / ppp / ppp_generic.c
blobf572b31a2b20cef55e560b8db932c419f14bd8b3
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/ppp-ioctl.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/spinlock.h>
44 #include <linux/rwsem.h>
45 #include <linux/stddef.h>
46 #include <linux/device.h>
47 #include <linux/mutex.h>
48 #include <linux/slab.h>
49 #include <asm/unaligned.h>
50 #include <net/slhc_vj.h>
51 #include <linux/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
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 to hold primary network stats for which
98 * we want to use 64 bit storage. Other network stats
99 * are stored in dev->stats of the ppp strucute.
100 */
101 struct ppp_link_stats {
102 u64 rx_packets;
103 u64 tx_packets;
104 u64 rx_bytes;
105 u64 tx_bytes;
106 };
107
108 /*
109 * Data structure describing one ppp unit.
110 * A ppp unit corresponds to a ppp network interface device
111 * and represents a multilink bundle.
112 * It can have 0 or more ppp channels connected to it.
113 */
114 struct ppp {
115 struct ppp_file file; /* stuff for read/write/poll 0 */
116 struct file *owner; /* file that owns this unit 48 */
117 struct list_head channels; /* list of attached channels 4c */
118 int n_channels; /* how many channels are attached 54 */
119 spinlock_t rlock; /* lock for receive side 58 */
120 spinlock_t wlock; /* lock for transmit side 5c */
121 int mru; /* max receive unit 60 */
122 unsigned int flags; /* control bits 64 */
123 unsigned int xstate; /* transmit state bits 68 */
124 unsigned int rstate; /* receive state bits 6c */
125 int debug; /* debug flags 70 */
126 struct slcompress *vj; /* state for VJ header compression */
127 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
128 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
129 struct compressor *xcomp; /* transmit packet compressor 8c */
130 void *xc_state; /* its internal state 90 */
131 struct compressor *rcomp; /* receive decompressor 94 */
132 void *rc_state; /* its internal state 98 */
133 unsigned long last_xmit; /* jiffies when last pkt sent 9c */
134 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
135 struct net_device *dev; /* network interface device a4 */
136 int closing; /* is device closing down? a8 */
137 #ifdef CONFIG_PPP_MULTILINK
138 int nxchan; /* next channel to send something on */
139 u32 nxseq; /* next sequence number to send */
140 int mrru; /* MP: max reconst. receive unit */
141 u32 nextseq; /* MP: seq no of next packet */
142 u32 minseq; /* MP: min of most recent seqnos */
143 struct sk_buff_head mrq; /* MP: receive reconstruction queue */
144 #endif /* CONFIG_PPP_MULTILINK */
145 #ifdef CONFIG_PPP_FILTER
146 struct bpf_prog *pass_filter; /* filter for packets to pass */
147 struct bpf_prog *active_filter; /* filter for pkts to reset idle */
148 #endif /* CONFIG_PPP_FILTER */
149 struct net *ppp_net; /* the net we belong to */
150 struct ppp_link_stats stats64; /* 64 bit network stats */
151 };
152
153 /*
154 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
155 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
156 * SC_MUST_COMP
157 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
158 * Bits in xstate: SC_COMP_RUN
159 */
160 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
161 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
162 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
163
164 /*
165 * Private data structure for each channel.
166 * This includes the data structure used for multilink.
167 */
168 struct channel {
169 struct ppp_file file; /* stuff for read/write/poll */
170 struct list_head list; /* link in all/new_channels list */
171 struct ppp_channel *chan; /* public channel data structure */
172 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
173 spinlock_t downl; /* protects `chan', file.xq dequeue */
174 struct ppp *ppp; /* ppp unit we're connected to */
175 struct net *chan_net; /* the net channel belongs to */
176 struct list_head clist; /* link in list of channels per unit */
177 rwlock_t upl; /* protects `ppp' */
178 #ifdef CONFIG_PPP_MULTILINK
179 u8 avail; /* flag used in multilink stuff */
180 u8 had_frag; /* >= 1 fragments have been sent */
181 u32 lastseq; /* MP: last sequence # received */
182 int speed; /* speed of the corresponding ppp channel*/
183 #endif /* CONFIG_PPP_MULTILINK */
184 };
185
186 /*
187 * SMP locking issues:
188 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
189 * list and the ppp.n_channels field, you need to take both locks
190 * before you modify them.
191 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
192 * channel.downl.
193 */
194
195 static DEFINE_MUTEX(ppp_mutex);
196 static atomic_t ppp_unit_count = ATOMIC_INIT(0);
197 static atomic_t channel_count = ATOMIC_INIT(0);
198
199 /* per-net private data for this module */
200 static int ppp_net_id __read_mostly;
201 struct ppp_net {
202 /* units to ppp mapping */
203 struct idr units_idr;
204
205 /*
206 * all_ppp_mutex protects the units_idr mapping.
207 * It also ensures that finding a ppp unit in the units_idr
208 * map and updating its file.refcnt field is atomic.
209 */
210 struct mutex all_ppp_mutex;
211
212 /* channels */
213 struct list_head all_channels;
214 struct list_head new_channels;
215 int last_channel_index;
216
217 /*
218 * all_channels_lock protects all_channels and
219 * last_channel_index, and the atomicity of find
220 * a channel and updating its file.refcnt field.
221 */
222 spinlock_t all_channels_lock;
223 };
224
225 /* Get the PPP protocol number from a skb */
226 #define PPP_PROTO(skb) get_unaligned_be16((skb)->data)
227
228 /* We limit the length of ppp->file.rq to this (arbitrary) value */
229 #define PPP_MAX_RQLEN 32
230
231 /*
232 * Maximum number of multilink fragments queued up.
233 * This has to be large enough to cope with the maximum latency of
234 * the slowest channel relative to the others. Strictly it should
235 * depend on the number of channels and their characteristics.
236 */
237 #define PPP_MP_MAX_QLEN 128
238
239 /* Multilink header bits. */
240 #define B 0x80 /* this fragment begins a packet */
241 #define E 0x40 /* this fragment ends a packet */
242
243 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */
244 #define seq_before(a, b) ((s32)((a) - (b)) < 0)
245 #define seq_after(a, b) ((s32)((a) - (b)) > 0)
246
247 /* Prototypes. */
248 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
249 struct file *file, unsigned int cmd, unsigned long arg);
250 static void ppp_xmit_process(struct ppp *ppp);
251 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
252 static void ppp_push(struct ppp *ppp);
253 static void ppp_channel_push(struct channel *pch);
254 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
255 struct channel *pch);
256 static void ppp_receive_error(struct ppp *ppp);
257 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
258 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
259 struct sk_buff *skb);
260 #ifdef CONFIG_PPP_MULTILINK
261 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
262 struct channel *pch);
263 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
264 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
265 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
266 #endif /* CONFIG_PPP_MULTILINK */
267 static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
268 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
269 static void ppp_ccp_closed(struct ppp *ppp);
270 static struct compressor *find_compressor(int type);
271 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
272 static struct ppp *ppp_create_interface(struct net *net, int unit,
273 struct file *file, int *retp);
274 static void init_ppp_file(struct ppp_file *pf, int kind);
275 static void ppp_destroy_interface(struct ppp *ppp);
276 static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit);
277 static struct channel *ppp_find_channel(struct ppp_net *pn, int unit);
278 static int ppp_connect_channel(struct channel *pch, int unit);
279 static int ppp_disconnect_channel(struct channel *pch);
280 static void ppp_destroy_channel(struct channel *pch);
281 static int unit_get(struct idr *p, void *ptr);
282 static int unit_set(struct idr *p, void *ptr, int n);
283 static void unit_put(struct idr *p, int n);
284 static void *unit_find(struct idr *p, int n);
285
286 static const struct net_device_ops ppp_netdev_ops;
287
288 static struct class *ppp_class;
289
290 /* per net-namespace data */
291 static inline struct ppp_net *ppp_pernet(struct net *net)
292 {
293 BUG_ON(!net);
294
295 return net_generic(net, ppp_net_id);
296 }
297
298 /* Translates a PPP protocol number to a NP index (NP == network protocol) */
299 static inline int proto_to_npindex(int proto)
300 {
301 switch (proto) {
302 case PPP_IP:
303 return NP_IP;
304 case PPP_IPV6:
305 return NP_IPV6;
306 case PPP_IPX:
307 return NP_IPX;
308 case PPP_AT:
309 return NP_AT;
310 case PPP_MPLS_UC:
311 return NP_MPLS_UC;
312 case PPP_MPLS_MC:
313 return NP_MPLS_MC;
314 }
315 return -EINVAL;
316 }
317
318 /* Translates an NP index into a PPP protocol number */
319 static const int npindex_to_proto[NUM_NP] = {
320 PPP_IP,
321 PPP_IPV6,
322 PPP_IPX,
323 PPP_AT,
324 PPP_MPLS_UC,
325 PPP_MPLS_MC,
326 };
327
328 /* Translates an ethertype into an NP index */
329 static inline int ethertype_to_npindex(int ethertype)
330 {
331 switch (ethertype) {
332 case ETH_P_IP:
333 return NP_IP;
334 case ETH_P_IPV6:
335 return NP_IPV6;
336 case ETH_P_IPX:
337 return NP_IPX;
338 case ETH_P_PPPTALK:
339 case ETH_P_ATALK:
340 return NP_AT;
341 case ETH_P_MPLS_UC:
342 return NP_MPLS_UC;
343 case ETH_P_MPLS_MC:
344 return NP_MPLS_MC;
345 }
346 return -1;
347 }
348
349 /* Translates an NP index into an ethertype */
350 static const int npindex_to_ethertype[NUM_NP] = {
351 ETH_P_IP,
352 ETH_P_IPV6,
353 ETH_P_IPX,
354 ETH_P_PPPTALK,
355 ETH_P_MPLS_UC,
356 ETH_P_MPLS_MC,
357 };
358
359 /*
360 * Locking shorthand.
361 */
362 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
363 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
364 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
365 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
366 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
367 ppp_recv_lock(ppp); } while (0)
368 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
369 ppp_xmit_unlock(ppp); } while (0)
370
371 /*
372 * /dev/ppp device routines.
373 * The /dev/ppp device is used by pppd to control the ppp unit.
374 * It supports the read, write, ioctl and poll functions.
375 * Open instances of /dev/ppp can be in one of three states:
376 * unattached, attached to a ppp unit, or attached to a ppp channel.
377 */
378 static int ppp_open(struct inode *inode, struct file *file)
379 {
380 /*
381 * This could (should?) be enforced by the permissions on /dev/ppp.
382 */
383 if (!capable(CAP_NET_ADMIN))
384 return -EPERM;
385 return 0;
386 }
387
388 static int ppp_release(struct inode *unused, struct file *file)
389 {
390 struct ppp_file *pf = file->private_data;
391 struct ppp *ppp;
392
393 if (pf) {
394 file->private_data = NULL;
395 if (pf->kind == INTERFACE) {
396 ppp = PF_TO_PPP(pf);
397 rtnl_lock();
398 if (file == ppp->owner)
399 unregister_netdevice(ppp->dev);
400 rtnl_unlock();
401 }
402 if (atomic_dec_and_test(&pf->refcnt)) {
403 switch (pf->kind) {
404 case INTERFACE:
405 ppp_destroy_interface(PF_TO_PPP(pf));
406 break;
407 case CHANNEL:
408 ppp_destroy_channel(PF_TO_CHANNEL(pf));
409 break;
410 }
411 }
412 }
413 return 0;
414 }
415
416 static ssize_t ppp_read(struct file *file, char __user *buf,
417 size_t count, loff_t *ppos)
418 {
419 struct ppp_file *pf = file->private_data;
420 DECLARE_WAITQUEUE(wait, current);
421 ssize_t ret;
422 struct sk_buff *skb = NULL;
423 struct iovec iov;
424 struct iov_iter to;
425
426 ret = count;
427
428 if (!pf)
429 return -ENXIO;
430 add_wait_queue(&pf->rwait, &wait);
431 for (;;) {
432 set_current_state(TASK_INTERRUPTIBLE);
433 skb = skb_dequeue(&pf->rq);
434 if (skb)
435 break;
436 ret = 0;
437 if (pf->dead)
438 break;
439 if (pf->kind == INTERFACE) {
440 /*
441 * Return 0 (EOF) on an interface that has no
442 * channels connected, unless it is looping
443 * network traffic (demand mode).
444 */
445 struct ppp *ppp = PF_TO_PPP(pf);
446
447 ppp_recv_lock(ppp);
448 if (ppp->n_channels == 0 &&
449 (ppp->flags & SC_LOOP_TRAFFIC) == 0) {
450 ppp_recv_unlock(ppp);
451 break;
452 }
453 ppp_recv_unlock(ppp);
454 }
455 ret = -EAGAIN;
456 if (file->f_flags & O_NONBLOCK)
457 break;
458 ret = -ERESTARTSYS;
459 if (signal_pending(current))
460 break;
461 schedule();
462 }
463 set_current_state(TASK_RUNNING);
464 remove_wait_queue(&pf->rwait, &wait);
465
466 if (!skb)
467 goto out;
468
469 ret = -EOVERFLOW;
470 if (skb->len > count)
471 goto outf;
472 ret = -EFAULT;
473 iov.iov_base = buf;
474 iov.iov_len = count;
475 iov_iter_init(&to, READ, &iov, 1, count);
476 if (skb_copy_datagram_iter(skb, 0, &to, skb->len))
477 goto outf;
478 ret = skb->len;
479
480 outf:
481 kfree_skb(skb);
482 out:
483 return ret;
484 }
485
486 static ssize_t ppp_write(struct file *file, const char __user *buf,
487 size_t count, loff_t *ppos)
488 {
489 struct ppp_file *pf = file->private_data;
490 struct sk_buff *skb;
491 ssize_t ret;
492
493 if (!pf)
494 return -ENXIO;
495 ret = -ENOMEM;
496 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
497 if (!skb)
498 goto out;
499 skb_reserve(skb, pf->hdrlen);
500 ret = -EFAULT;
501 if (copy_from_user(skb_put(skb, count), buf, count)) {
502 kfree_skb(skb);
503 goto out;
504 }
505
506 skb_queue_tail(&pf->xq, skb);
507
508 switch (pf->kind) {
509 case INTERFACE:
510 ppp_xmit_process(PF_TO_PPP(pf));
511 break;
512 case CHANNEL:
513 ppp_channel_push(PF_TO_CHANNEL(pf));
514 break;
515 }
516
517 ret = count;
518
519 out:
520 return ret;
521 }
522
523 /* No kernel lock - fine */
524 static unsigned int ppp_poll(struct file *file, poll_table *wait)
525 {
526 struct ppp_file *pf = file->private_data;
527 unsigned int mask;
528
529 if (!pf)
530 return 0;
531 poll_wait(file, &pf->rwait, wait);
532 mask = POLLOUT | POLLWRNORM;
533 if (skb_peek(&pf->rq))
534 mask |= POLLIN | POLLRDNORM;
535 if (pf->dead)
536 mask |= POLLHUP;
537 else if (pf->kind == INTERFACE) {
538 /* see comment in ppp_read */
539 struct ppp *ppp = PF_TO_PPP(pf);
540
541 ppp_recv_lock(ppp);
542 if (ppp->n_channels == 0 &&
543 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
544 mask |= POLLIN | POLLRDNORM;
545 ppp_recv_unlock(ppp);
546 }
547
548 return mask;
549 }
550
551 #ifdef CONFIG_PPP_FILTER
552 static int get_filter(void __user *arg, struct sock_filter **p)
553 {
554 struct sock_fprog uprog;
555 struct sock_filter *code = NULL;
556 int len;
557
558 if (copy_from_user(&uprog, arg, sizeof(uprog)))
559 return -EFAULT;
560
561 if (!uprog.len) {
562 *p = NULL;
563 return 0;
564 }
565
566 len = uprog.len * sizeof(struct sock_filter);
567 code = memdup_user(uprog.filter, len);
568 if (IS_ERR(code))
569 return PTR_ERR(code);
570
571 *p = code;
572 return uprog.len;
573 }
574 #endif /* CONFIG_PPP_FILTER */
575
576 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
577 {
578 struct ppp_file *pf;
579 struct ppp *ppp;
580 int err = -EFAULT, val, val2, i;
581 struct ppp_idle idle;
582 struct npioctl npi;
583 int unit, cflags;
584 struct slcompress *vj;
585 void __user *argp = (void __user *)arg;
586 int __user *p = argp;
587
588 mutex_lock(&ppp_mutex);
589
590 pf = file->private_data;
591 if (!pf) {
592 err = ppp_unattached_ioctl(current->nsproxy->net_ns,
593 pf, file, cmd, arg);
594 goto out;
595 }
596
597 if (cmd == PPPIOCDETACH) {
598 /*
599 * We have to be careful here... if the file descriptor
600 * has been dup'd, we could have another process in the
601 * middle of a poll using the same file *, so we had
602 * better not free the interface data structures -
603 * instead we fail the ioctl. Even in this case, we
604 * shut down the interface if we are the owner of it.
605 * Actually, we should get rid of PPPIOCDETACH, userland
606 * (i.e. pppd) could achieve the same effect by closing
607 * this fd and reopening /dev/ppp.
608 */
609 err = -EINVAL;
610 if (pf->kind == INTERFACE) {
611 ppp = PF_TO_PPP(pf);
612 rtnl_lock();
613 if (file == ppp->owner)
614 unregister_netdevice(ppp->dev);
615 rtnl_unlock();
616 }
617 if (atomic_long_read(&file->f_count) < 2) {
618 ppp_release(NULL, file);
619 err = 0;
620 } else
621 pr_warn("PPPIOCDETACH file->f_count=%ld\n",
622 atomic_long_read(&file->f_count));
623 goto out;
624 }
625
626 if (pf->kind == CHANNEL) {
627 struct channel *pch;
628 struct ppp_channel *chan;
629
630 pch = PF_TO_CHANNEL(pf);
631
632 switch (cmd) {
633 case PPPIOCCONNECT:
634 if (get_user(unit, p))
635 break;
636 err = ppp_connect_channel(pch, unit);
637 break;
638
639 case PPPIOCDISCONN:
640 err = ppp_disconnect_channel(pch);
641 break;
642
643 default:
644 down_read(&pch->chan_sem);
645 chan = pch->chan;
646 err = -ENOTTY;
647 if (chan && chan->ops->ioctl)
648 err = chan->ops->ioctl(chan, cmd, arg);
649 up_read(&pch->chan_sem);
650 }
651 goto out;
652 }
653
654 if (pf->kind != INTERFACE) {
655 /* can't happen */
656 pr_err("PPP: not interface or channel??\n");
657 err = -EINVAL;
658 goto out;
659 }
660
661 ppp = PF_TO_PPP(pf);
662 switch (cmd) {
663 case PPPIOCSMRU:
664 if (get_user(val, p))
665 break;
666 ppp->mru = val;
667 err = 0;
668 break;
669
670 case PPPIOCSFLAGS:
671 if (get_user(val, p))
672 break;
673 ppp_lock(ppp);
674 cflags = ppp->flags & ~val;
675 #ifdef CONFIG_PPP_MULTILINK
676 if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK))
677 ppp->nextseq = 0;
678 #endif
679 ppp->flags = val & SC_FLAG_BITS;
680 ppp_unlock(ppp);
681 if (cflags & SC_CCP_OPEN)
682 ppp_ccp_closed(ppp);
683 err = 0;
684 break;
685
686 case PPPIOCGFLAGS:
687 val = ppp->flags | ppp->xstate | ppp->rstate;
688 if (put_user(val, p))
689 break;
690 err = 0;
691 break;
692
693 case PPPIOCSCOMPRESS:
694 err = ppp_set_compress(ppp, arg);
695 break;
696
697 case PPPIOCGUNIT:
698 if (put_user(ppp->file.index, p))
699 break;
700 err = 0;
701 break;
702
703 case PPPIOCSDEBUG:
704 if (get_user(val, p))
705 break;
706 ppp->debug = val;
707 err = 0;
708 break;
709
710 case PPPIOCGDEBUG:
711 if (put_user(ppp->debug, p))
712 break;
713 err = 0;
714 break;
715
716 case PPPIOCGIDLE:
717 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
718 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
719 if (copy_to_user(argp, &idle, sizeof(idle)))
720 break;
721 err = 0;
722 break;
723
724 case PPPIOCSMAXCID:
725 if (get_user(val, p))
726 break;
727 val2 = 15;
728 if ((val >> 16) != 0) {
729 val2 = val >> 16;
730 val &= 0xffff;
731 }
732 vj = slhc_init(val2+1, val+1);
733 if (IS_ERR(vj)) {
734 err = PTR_ERR(vj);
735 break;
736 }
737 ppp_lock(ppp);
738 if (ppp->vj)
739 slhc_free(ppp->vj);
740 ppp->vj = vj;
741 ppp_unlock(ppp);
742 err = 0;
743 break;
744
745 case PPPIOCGNPMODE:
746 case PPPIOCSNPMODE:
747 if (copy_from_user(&npi, argp, sizeof(npi)))
748 break;
749 err = proto_to_npindex(npi.protocol);
750 if (err < 0)
751 break;
752 i = err;
753 if (cmd == PPPIOCGNPMODE) {
754 err = -EFAULT;
755 npi.mode = ppp->npmode[i];
756 if (copy_to_user(argp, &npi, sizeof(npi)))
757 break;
758 } else {
759 ppp->npmode[i] = npi.mode;
760 /* we may be able to transmit more packets now (??) */
761 netif_wake_queue(ppp->dev);
762 }
763 err = 0;
764 break;
765
766 #ifdef CONFIG_PPP_FILTER
767 case PPPIOCSPASS:
768 {
769 struct sock_filter *code;
770
771 err = get_filter(argp, &code);
772 if (err >= 0) {
773 struct bpf_prog *pass_filter = NULL;
774 struct sock_fprog_kern fprog = {
775 .len = err,
776 .filter = code,
777 };
778
779 err = 0;
780 if (fprog.filter)
781 err = bpf_prog_create(&pass_filter, &fprog);
782 if (!err) {
783 ppp_lock(ppp);
784 if (ppp->pass_filter)
785 bpf_prog_destroy(ppp->pass_filter);
786 ppp->pass_filter = pass_filter;
787 ppp_unlock(ppp);
788 }
789 kfree(code);
790 }
791 break;
792 }
793 case PPPIOCSACTIVE:
794 {
795 struct sock_filter *code;
796
797 err = get_filter(argp, &code);
798 if (err >= 0) {
799 struct bpf_prog *active_filter = NULL;
800 struct sock_fprog_kern fprog = {
801 .len = err,
802 .filter = code,
803 };
804
805 err = 0;
806 if (fprog.filter)
807 err = bpf_prog_create(&active_filter, &fprog);
808 if (!err) {
809 ppp_lock(ppp);
810 if (ppp->active_filter)
811 bpf_prog_destroy(ppp->active_filter);
812 ppp->active_filter = active_filter;
813 ppp_unlock(ppp);
814 }
815 kfree(code);
816 }
817 break;
818 }
819 #endif /* CONFIG_PPP_FILTER */
820
821 #ifdef CONFIG_PPP_MULTILINK
822 case PPPIOCSMRRU:
823 if (get_user(val, p))
824 break;
825 ppp_recv_lock(ppp);
826 ppp->mrru = val;
827 ppp_recv_unlock(ppp);
828 err = 0;
829 break;
830 #endif /* CONFIG_PPP_MULTILINK */
831
832 default:
833 err = -ENOTTY;
834 }
835
836 out:
837 mutex_unlock(&ppp_mutex);
838
839 return err;
840 }
841
842 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
843 struct file *file, unsigned int cmd, unsigned long arg)
844 {
845 int unit, err = -EFAULT;
846 struct ppp *ppp;
847 struct channel *chan;
848 struct ppp_net *pn;
849 int __user *p = (int __user *)arg;
850
851 switch (cmd) {
852 case PPPIOCNEWUNIT:
853 /* Create a new ppp unit */
854 if (get_user(unit, p))
855 break;
856 ppp = ppp_create_interface(net, unit, file, &err);
857 if (!ppp)
858 break;
859 file->private_data = &ppp->file;
860 err = -EFAULT;
861 if (put_user(ppp->file.index, p))
862 break;
863 err = 0;
864 break;
865
866 case PPPIOCATTACH:
867 /* Attach to an existing ppp unit */
868 if (get_user(unit, p))
869 break;
870 err = -ENXIO;
871 pn = ppp_pernet(net);
872 mutex_lock(&pn->all_ppp_mutex);
873 ppp = ppp_find_unit(pn, unit);
874 if (ppp) {
875 atomic_inc(&ppp->file.refcnt);
876 file->private_data = &ppp->file;
877 err = 0;
878 }
879 mutex_unlock(&pn->all_ppp_mutex);
880 break;
881
882 case PPPIOCATTCHAN:
883 if (get_user(unit, p))
884 break;
885 err = -ENXIO;
886 pn = ppp_pernet(net);
887 spin_lock_bh(&pn->all_channels_lock);
888 chan = ppp_find_channel(pn, unit);
889 if (chan) {
890 atomic_inc(&chan->file.refcnt);
891 file->private_data = &chan->file;
892 err = 0;
893 }
894 spin_unlock_bh(&pn->all_channels_lock);
895 break;
896
897 default:
898 err = -ENOTTY;
899 }
900
901 return err;
902 }
903
904 static const struct file_operations ppp_device_fops = {
905 .owner = THIS_MODULE,
906 .read = ppp_read,
907 .write = ppp_write,
908 .poll = ppp_poll,
909 .unlocked_ioctl = ppp_ioctl,
910 .open = ppp_open,
911 .release = ppp_release,
912 .llseek = noop_llseek,
913 };
914
915 static __net_init int ppp_init_net(struct net *net)
916 {
917 struct ppp_net *pn = net_generic(net, ppp_net_id);
918
919 idr_init(&pn->units_idr);
920 mutex_init(&pn->all_ppp_mutex);
921
922 INIT_LIST_HEAD(&pn->all_channels);
923 INIT_LIST_HEAD(&pn->new_channels);
924
925 spin_lock_init(&pn->all_channels_lock);
926
927 return 0;
928 }
929
930 static __net_exit void ppp_exit_net(struct net *net)
931 {
932 struct ppp_net *pn = net_generic(net, ppp_net_id);
933 struct net_device *dev;
934 struct net_device *aux;
935 struct ppp *ppp;
936 LIST_HEAD(list);
937 int id;
938
939 rtnl_lock();
940 for_each_netdev_safe(net, dev, aux) {
941 if (dev->netdev_ops == &ppp_netdev_ops)
942 unregister_netdevice_queue(dev, &list);
943 }
944
945 idr_for_each_entry(&pn->units_idr, ppp, id)
946 /* Skip devices already unregistered by previous loop */
947 if (!net_eq(dev_net(ppp->dev), net))
948 unregister_netdevice_queue(ppp->dev, &list);
949
950 unregister_netdevice_many(&list);
951 rtnl_unlock();
952
953 idr_destroy(&pn->units_idr);
954 }
955
956 static struct pernet_operations ppp_net_ops = {
957 .init = ppp_init_net,
958 .exit = ppp_exit_net,
959 .id = &ppp_net_id,
960 .size = sizeof(struct ppp_net),
961 };
962
963 #define PPP_MAJOR 108
964
965 /* Called at boot time if ppp is compiled into the kernel,
966 or at module load time (from init_module) if compiled as a module. */
967 static int __init ppp_init(void)
968 {
969 int err;
970
971 pr_info("PPP generic driver version " PPP_VERSION "\n");
972
973 err = register_pernet_device(&ppp_net_ops);
974 if (err) {
975 pr_err("failed to register PPP pernet device (%d)\n", err);
976 goto out;
977 }
978
979 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
980 if (err) {
981 pr_err("failed to register PPP device (%d)\n", err);
982 goto out_net;
983 }
984
985 ppp_class = class_create(THIS_MODULE, "ppp");
986 if (IS_ERR(ppp_class)) {
987 err = PTR_ERR(ppp_class);
988 goto out_chrdev;
989 }
990
991 /* not a big deal if we fail here :-) */
992 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
993
994 return 0;
995
996 out_chrdev:
997 unregister_chrdev(PPP_MAJOR, "ppp");
998 out_net:
999 unregister_pernet_device(&ppp_net_ops);
1000 out:
1001 return err;
1002 }
1003
1004 /*
1005 * Network interface unit routines.
1006 */
1007 static netdev_tx_t
1008 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
1009 {
1010 struct ppp *ppp = netdev_priv(dev);
1011 int npi, proto;
1012 unsigned char *pp;
1013
1014 npi = ethertype_to_npindex(ntohs(skb->protocol));
1015 if (npi < 0)
1016 goto outf;
1017
1018 /* Drop, accept or reject the packet */
1019 switch (ppp->npmode[npi]) {
1020 case NPMODE_PASS:
1021 break;
1022 case NPMODE_QUEUE:
1023 /* it would be nice to have a way to tell the network
1024 system to queue this one up for later. */
1025 goto outf;
1026 case NPMODE_DROP:
1027 case NPMODE_ERROR:
1028 goto outf;
1029 }
1030
1031 /* Put the 2-byte PPP protocol number on the front,
1032 making sure there is room for the address and control fields. */
1033 if (skb_cow_head(skb, PPP_HDRLEN))
1034 goto outf;
1035
1036 pp = skb_push(skb, 2);
1037 proto = npindex_to_proto[npi];
1038 put_unaligned_be16(proto, pp);
1039
1040 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, dev_net(dev)));
1041 skb_queue_tail(&ppp->file.xq, skb);
1042 ppp_xmit_process(ppp);
1043 return NETDEV_TX_OK;
1044
1045 outf:
1046 kfree_skb(skb);
1047 ++dev->stats.tx_dropped;
1048 return NETDEV_TX_OK;
1049 }
1050
1051 static int
1052 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1053 {
1054 struct ppp *ppp = netdev_priv(dev);
1055 int err = -EFAULT;
1056 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
1057 struct ppp_stats stats;
1058 struct ppp_comp_stats cstats;
1059 char *vers;
1060
1061 switch (cmd) {
1062 case SIOCGPPPSTATS:
1063 ppp_get_stats(ppp, &stats);
1064 if (copy_to_user(addr, &stats, sizeof(stats)))
1065 break;
1066 err = 0;
1067 break;
1068
1069 case SIOCGPPPCSTATS:
1070 memset(&cstats, 0, sizeof(cstats));
1071 if (ppp->xc_state)
1072 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
1073 if (ppp->rc_state)
1074 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
1075 if (copy_to_user(addr, &cstats, sizeof(cstats)))
1076 break;
1077 err = 0;
1078 break;
1079
1080 case SIOCGPPPVER:
1081 vers = PPP_VERSION;
1082 if (copy_to_user(addr, vers, strlen(vers) + 1))
1083 break;
1084 err = 0;
1085 break;
1086
1087 default:
1088 err = -EINVAL;
1089 }
1090
1091 return err;
1092 }
1093
1094 static struct rtnl_link_stats64*
1095 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64)
1096 {
1097 struct ppp *ppp = netdev_priv(dev);
1098
1099 ppp_recv_lock(ppp);
1100 stats64->rx_packets = ppp->stats64.rx_packets;
1101 stats64->rx_bytes = ppp->stats64.rx_bytes;
1102 ppp_recv_unlock(ppp);
1103
1104 ppp_xmit_lock(ppp);
1105 stats64->tx_packets = ppp->stats64.tx_packets;
1106 stats64->tx_bytes = ppp->stats64.tx_bytes;
1107 ppp_xmit_unlock(ppp);
1108
1109 stats64->rx_errors = dev->stats.rx_errors;
1110 stats64->tx_errors = dev->stats.tx_errors;
1111 stats64->rx_dropped = dev->stats.rx_dropped;
1112 stats64->tx_dropped = dev->stats.tx_dropped;
1113 stats64->rx_length_errors = dev->stats.rx_length_errors;
1114
1115 return stats64;
1116 }
1117
1118 static struct lock_class_key ppp_tx_busylock;
1119 static int ppp_dev_init(struct net_device *dev)
1120 {
1121 dev->qdisc_tx_busylock = &ppp_tx_busylock;
1122 return 0;
1123 }
1124
1125 static void ppp_dev_uninit(struct net_device *dev)
1126 {
1127 struct ppp *ppp = netdev_priv(dev);
1128 struct ppp_net *pn = ppp_pernet(ppp->ppp_net);
1129
1130 ppp_lock(ppp);
1131 ppp->closing = 1;
1132 ppp_unlock(ppp);
1133
1134 mutex_lock(&pn->all_ppp_mutex);
1135 unit_put(&pn->units_idr, ppp->file.index);
1136 mutex_unlock(&pn->all_ppp_mutex);
1137
1138 ppp->owner = NULL;
1139
1140 ppp->file.dead = 1;
1141 wake_up_interruptible(&ppp->file.rwait);
1142 }
1143
1144 static const struct net_device_ops ppp_netdev_ops = {
1145 .ndo_init = ppp_dev_init,
1146 .ndo_uninit = ppp_dev_uninit,
1147 .ndo_start_xmit = ppp_start_xmit,
1148 .ndo_do_ioctl = ppp_net_ioctl,
1149 .ndo_get_stats64 = ppp_get_stats64,
1150 };
1151
1152 static struct device_type ppp_type = {
1153 .name = "ppp",
1154 };
1155
1156 static void ppp_setup(struct net_device *dev)
1157 {
1158 dev->netdev_ops = &ppp_netdev_ops;
1159 SET_NETDEV_DEVTYPE(dev, &ppp_type);
1160
1161 dev->hard_header_len = PPP_HDRLEN;
1162 dev->mtu = PPP_MRU;
1163 dev->addr_len = 0;
1164 dev->tx_queue_len = 3;
1165 dev->type = ARPHRD_PPP;
1166 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1167 netif_keep_dst(dev);
1168 }
1169
1170 /*
1171 * Transmit-side routines.
1172 */
1173
1174 /*
1175 * Called to do any work queued up on the transmit side
1176 * that can now be done.
1177 */
1178 static void
1179 ppp_xmit_process(struct ppp *ppp)
1180 {
1181 struct sk_buff *skb;
1182
1183 ppp_xmit_lock(ppp);
1184 if (!ppp->closing) {
1185 ppp_push(ppp);
1186 while (!ppp->xmit_pending &&
1187 (skb = skb_dequeue(&ppp->file.xq)))
1188 ppp_send_frame(ppp, skb);
1189 /* If there's no work left to do, tell the core net
1190 code that we can accept some more. */
1191 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1192 netif_wake_queue(ppp->dev);
1193 else
1194 netif_stop_queue(ppp->dev);
1195 }
1196 ppp_xmit_unlock(ppp);
1197 }
1198
1199 static inline struct sk_buff *
1200 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1201 {
1202 struct sk_buff *new_skb;
1203 int len;
1204 int new_skb_size = ppp->dev->mtu +
1205 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1206 int compressor_skb_size = ppp->dev->mtu +
1207 ppp->xcomp->comp_extra + PPP_HDRLEN;
1208 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1209 if (!new_skb) {
1210 if (net_ratelimit())
1211 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n");
1212 return NULL;
1213 }
1214 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1215 skb_reserve(new_skb,
1216 ppp->dev->hard_header_len - PPP_HDRLEN);
1217
1218 /* compressor still expects A/C bytes in hdr */
1219 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1220 new_skb->data, skb->len + 2,
1221 compressor_skb_size);
1222 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1223 consume_skb(skb);
1224 skb = new_skb;
1225 skb_put(skb, len);
1226 skb_pull(skb, 2); /* pull off A/C bytes */
1227 } else if (len == 0) {
1228 /* didn't compress, or CCP not up yet */
1229 consume_skb(new_skb);
1230 new_skb = skb;
1231 } else {
1232 /*
1233 * (len < 0)
1234 * MPPE requires that we do not send unencrypted
1235 * frames. The compressor will return -1 if we
1236 * should drop the frame. We cannot simply test
1237 * the compress_proto because MPPE and MPPC share
1238 * the same number.
1239 */
1240 if (net_ratelimit())
1241 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n");
1242 kfree_skb(skb);
1243 consume_skb(new_skb);
1244 new_skb = NULL;
1245 }
1246 return new_skb;
1247 }
1248
1249 /*
1250 * Compress and send a frame.
1251 * The caller should have locked the xmit path,
1252 * and xmit_pending should be 0.
1253 */
1254 static void
1255 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1256 {
1257 int proto = PPP_PROTO(skb);
1258 struct sk_buff *new_skb;
1259 int len;
1260 unsigned char *cp;
1261
1262 if (proto < 0x8000) {
1263 #ifdef CONFIG_PPP_FILTER
1264 /* check if we should pass this packet */
1265 /* the filter instructions are constructed assuming
1266 a four-byte PPP header on each packet */
1267 *skb_push(skb, 2) = 1;
1268 if (ppp->pass_filter &&
1269 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
1270 if (ppp->debug & 1)
1271 netdev_printk(KERN_DEBUG, ppp->dev,
1272 "PPP: outbound frame "
1273 "not passed\n");
1274 kfree_skb(skb);
1275 return;
1276 }
1277 /* if this packet passes the active filter, record the time */
1278 if (!(ppp->active_filter &&
1279 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
1280 ppp->last_xmit = jiffies;
1281 skb_pull(skb, 2);
1282 #else
1283 /* for data packets, record the time */
1284 ppp->last_xmit = jiffies;
1285 #endif /* CONFIG_PPP_FILTER */
1286 }
1287
1288 ++ppp->stats64.tx_packets;
1289 ppp->stats64.tx_bytes += skb->len - 2;
1290
1291 switch (proto) {
1292 case PPP_IP:
1293 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1294 break;
1295 /* try to do VJ TCP header compression */
1296 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1297 GFP_ATOMIC);
1298 if (!new_skb) {
1299 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n");
1300 goto drop;
1301 }
1302 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1303 cp = skb->data + 2;
1304 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1305 new_skb->data + 2, &cp,
1306 !(ppp->flags & SC_NO_TCP_CCID));
1307 if (cp == skb->data + 2) {
1308 /* didn't compress */
1309 consume_skb(new_skb);
1310 } else {
1311 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1312 proto = PPP_VJC_COMP;
1313 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1314 } else {
1315 proto = PPP_VJC_UNCOMP;
1316 cp[0] = skb->data[2];
1317 }
1318 consume_skb(skb);
1319 skb = new_skb;
1320 cp = skb_put(skb, len + 2);
1321 cp[0] = 0;
1322 cp[1] = proto;
1323 }
1324 break;
1325
1326 case PPP_CCP:
1327 /* peek at outbound CCP frames */
1328 ppp_ccp_peek(ppp, skb, 0);
1329 break;
1330 }
1331
1332 /* try to do packet compression */
1333 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state &&
1334 proto != PPP_LCP && proto != PPP_CCP) {
1335 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1336 if (net_ratelimit())
1337 netdev_err(ppp->dev,
1338 "ppp: compression required but "
1339 "down - pkt dropped.\n");
1340 goto drop;
1341 }
1342 skb = pad_compress_skb(ppp, skb);
1343 if (!skb)
1344 goto drop;
1345 }
1346
1347 /*
1348 * If we are waiting for traffic (demand dialling),
1349 * queue it up for pppd to receive.
1350 */
1351 if (ppp->flags & SC_LOOP_TRAFFIC) {
1352 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1353 goto drop;
1354 skb_queue_tail(&ppp->file.rq, skb);
1355 wake_up_interruptible(&ppp->file.rwait);
1356 return;
1357 }
1358
1359 ppp->xmit_pending = skb;
1360 ppp_push(ppp);
1361 return;
1362
1363 drop:
1364 kfree_skb(skb);
1365 ++ppp->dev->stats.tx_errors;
1366 }
1367
1368 /*
1369 * Try to send the frame in xmit_pending.
1370 * The caller should have the xmit path locked.
1371 */
1372 static void
1373 ppp_push(struct ppp *ppp)
1374 {
1375 struct list_head *list;
1376 struct channel *pch;
1377 struct sk_buff *skb = ppp->xmit_pending;
1378
1379 if (!skb)
1380 return;
1381
1382 list = &ppp->channels;
1383 if (list_empty(list)) {
1384 /* nowhere to send the packet, just drop it */
1385 ppp->xmit_pending = NULL;
1386 kfree_skb(skb);
1387 return;
1388 }
1389
1390 if ((ppp->flags & SC_MULTILINK) == 0) {
1391 /* not doing multilink: send it down the first channel */
1392 list = list->next;
1393 pch = list_entry(list, struct channel, clist);
1394
1395 spin_lock_bh(&pch->downl);
1396 if (pch->chan) {
1397 if (pch->chan->ops->start_xmit(pch->chan, skb))
1398 ppp->xmit_pending = NULL;
1399 } else {
1400 /* channel got unregistered */
1401 kfree_skb(skb);
1402 ppp->xmit_pending = NULL;
1403 }
1404 spin_unlock_bh(&pch->downl);
1405 return;
1406 }
1407
1408 #ifdef CONFIG_PPP_MULTILINK
1409 /* Multilink: fragment the packet over as many links
1410 as can take the packet at the moment. */
1411 if (!ppp_mp_explode(ppp, skb))
1412 return;
1413 #endif /* CONFIG_PPP_MULTILINK */
1414
1415 ppp->xmit_pending = NULL;
1416 kfree_skb(skb);
1417 }
1418
1419 #ifdef CONFIG_PPP_MULTILINK
1420 static bool mp_protocol_compress __read_mostly = true;
1421 module_param(mp_protocol_compress, bool, S_IRUGO | S_IWUSR);
1422 MODULE_PARM_DESC(mp_protocol_compress,
1423 "compress protocol id in multilink fragments");
1424
1425 /*
1426 * Divide a packet to be transmitted into fragments and
1427 * send them out the individual links.
1428 */
1429 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1430 {
1431 int len, totlen;
1432 int i, bits, hdrlen, mtu;
1433 int flen;
1434 int navail, nfree, nzero;
1435 int nbigger;
1436 int totspeed;
1437 int totfree;
1438 unsigned char *p, *q;
1439 struct list_head *list;
1440 struct channel *pch;
1441 struct sk_buff *frag;
1442 struct ppp_channel *chan;
1443
1444 totspeed = 0; /*total bitrate of the bundle*/
1445 nfree = 0; /* # channels which have no packet already queued */
1446 navail = 0; /* total # of usable channels (not deregistered) */
1447 nzero = 0; /* number of channels with zero speed associated*/
1448 totfree = 0; /*total # of channels available and
1449 *having no queued packets before
1450 *starting the fragmentation*/
1451
1452 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1453 i = 0;
1454 list_for_each_entry(pch, &ppp->channels, clist) {
1455 if (pch->chan) {
1456 pch->avail = 1;
1457 navail++;
1458 pch->speed = pch->chan->speed;
1459 } else {
1460 pch->avail = 0;
1461 }
1462 if (pch->avail) {
1463 if (skb_queue_empty(&pch->file.xq) ||
1464 !pch->had_frag) {
1465 if (pch->speed == 0)
1466 nzero++;
1467 else
1468 totspeed += pch->speed;
1469
1470 pch->avail = 2;
1471 ++nfree;
1472 ++totfree;
1473 }
1474 if (!pch->had_frag && i < ppp->nxchan)
1475 ppp->nxchan = i;
1476 }
1477 ++i;
1478 }
1479 /*
1480 * Don't start sending this packet unless at least half of
1481 * the channels are free. This gives much better TCP
1482 * performance if we have a lot of channels.
1483 */
1484 if (nfree == 0 || nfree < navail / 2)
1485 return 0; /* can't take now, leave it in xmit_pending */
1486
1487 /* Do protocol field compression */
1488 p = skb->data;
1489 len = skb->len;
1490 if (*p == 0 && mp_protocol_compress) {
1491 ++p;
1492 --len;
1493 }
1494
1495 totlen = len;
1496 nbigger = len % nfree;
1497
1498 /* skip to the channel after the one we last used
1499 and start at that one */
1500 list = &ppp->channels;
1501 for (i = 0; i < ppp->nxchan; ++i) {
1502 list = list->next;
1503 if (list == &ppp->channels) {
1504 i = 0;
1505 break;
1506 }
1507 }
1508
1509 /* create a fragment for each channel */
1510 bits = B;
1511 while (len > 0) {
1512 list = list->next;
1513 if (list == &ppp->channels) {
1514 i = 0;
1515 continue;
1516 }
1517 pch = list_entry(list, struct channel, clist);
1518 ++i;
1519 if (!pch->avail)
1520 continue;
1521
1522 /*
1523 * Skip this channel if it has a fragment pending already and
1524 * we haven't given a fragment to all of the free channels.
1525 */
1526 if (pch->avail == 1) {
1527 if (nfree > 0)
1528 continue;
1529 } else {
1530 pch->avail = 1;
1531 }
1532
1533 /* check the channel's mtu and whether it is still attached. */
1534 spin_lock_bh(&pch->downl);
1535 if (pch->chan == NULL) {
1536 /* can't use this channel, it's being deregistered */
1537 if (pch->speed == 0)
1538 nzero--;
1539 else
1540 totspeed -= pch->speed;
1541
1542 spin_unlock_bh(&pch->downl);
1543 pch->avail = 0;
1544 totlen = len;
1545 totfree--;
1546 nfree--;
1547 if (--navail == 0)
1548 break;
1549 continue;
1550 }
1551
1552 /*
1553 *if the channel speed is not set divide
1554 *the packet evenly among the free channels;
1555 *otherwise divide it according to the speed
1556 *of the channel we are going to transmit on
1557 */
1558 flen = len;
1559 if (nfree > 0) {
1560 if (pch->speed == 0) {
1561 flen = len/nfree;
1562 if (nbigger > 0) {
1563 flen++;
1564 nbigger--;
1565 }
1566 } else {
1567 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
1568 ((totspeed*totfree)/pch->speed)) - hdrlen;
1569 if (nbigger > 0) {
1570 flen += ((totfree - nzero)*pch->speed)/totspeed;
1571 nbigger -= ((totfree - nzero)*pch->speed)/
1572 totspeed;
1573 }
1574 }
1575 nfree--;
1576 }
1577
1578 /*
1579 *check if we are on the last channel or
1580 *we exceded the length of the data to
1581 *fragment
1582 */
1583 if ((nfree <= 0) || (flen > len))
1584 flen = len;
1585 /*
1586 *it is not worth to tx on slow channels:
1587 *in that case from the resulting flen according to the
1588 *above formula will be equal or less than zero.
1589 *Skip the channel in this case
1590 */
1591 if (flen <= 0) {
1592 pch->avail = 2;
1593 spin_unlock_bh(&pch->downl);
1594 continue;
1595 }
1596
1597 /*
1598 * hdrlen includes the 2-byte PPP protocol field, but the
1599 * MTU counts only the payload excluding the protocol field.
1600 * (RFC1661 Section 2)
1601 */
1602 mtu = pch->chan->mtu - (hdrlen - 2);
1603 if (mtu < 4)
1604 mtu = 4;
1605 if (flen > mtu)
1606 flen = mtu;
1607 if (flen == len)
1608 bits |= E;
1609 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1610 if (!frag)
1611 goto noskb;
1612 q = skb_put(frag, flen + hdrlen);
1613
1614 /* make the MP header */
1615 put_unaligned_be16(PPP_MP, q);
1616 if (ppp->flags & SC_MP_XSHORTSEQ) {
1617 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1618 q[3] = ppp->nxseq;
1619 } else {
1620 q[2] = bits;
1621 q[3] = ppp->nxseq >> 16;
1622 q[4] = ppp->nxseq >> 8;
1623 q[5] = ppp->nxseq;
1624 }
1625
1626 memcpy(q + hdrlen, p, flen);
1627
1628 /* try to send it down the channel */
1629 chan = pch->chan;
1630 if (!skb_queue_empty(&pch->file.xq) ||
1631 !chan->ops->start_xmit(chan, frag))
1632 skb_queue_tail(&pch->file.xq, frag);
1633 pch->had_frag = 1;
1634 p += flen;
1635 len -= flen;
1636 ++ppp->nxseq;
1637 bits = 0;
1638 spin_unlock_bh(&pch->downl);
1639 }
1640 ppp->nxchan = i;
1641
1642 return 1;
1643
1644 noskb:
1645 spin_unlock_bh(&pch->downl);
1646 if (ppp->debug & 1)
1647 netdev_err(ppp->dev, "PPP: no memory (fragment)\n");
1648 ++ppp->dev->stats.tx_errors;
1649 ++ppp->nxseq;
1650 return 1; /* abandon the frame */
1651 }
1652 #endif /* CONFIG_PPP_MULTILINK */
1653
1654 /*
1655 * Try to send data out on a channel.
1656 */
1657 static void
1658 ppp_channel_push(struct channel *pch)
1659 {
1660 struct sk_buff *skb;
1661 struct ppp *ppp;
1662
1663 spin_lock_bh(&pch->downl);
1664 if (pch->chan) {
1665 while (!skb_queue_empty(&pch->file.xq)) {
1666 skb = skb_dequeue(&pch->file.xq);
1667 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1668 /* put the packet back and try again later */
1669 skb_queue_head(&pch->file.xq, skb);
1670 break;
1671 }
1672 }
1673 } else {
1674 /* channel got deregistered */
1675 skb_queue_purge(&pch->file.xq);
1676 }
1677 spin_unlock_bh(&pch->downl);
1678 /* see if there is anything from the attached unit to be sent */
1679 if (skb_queue_empty(&pch->file.xq)) {
1680 read_lock_bh(&pch->upl);
1681 ppp = pch->ppp;
1682 if (ppp)
1683 ppp_xmit_process(ppp);
1684 read_unlock_bh(&pch->upl);
1685 }
1686 }
1687
1688 /*
1689 * Receive-side routines.
1690 */
1691
1692 struct ppp_mp_skb_parm {
1693 u32 sequence;
1694 u8 BEbits;
1695 };
1696 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb))
1697
1698 static inline void
1699 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1700 {
1701 ppp_recv_lock(ppp);
1702 if (!ppp->closing)
1703 ppp_receive_frame(ppp, skb, pch);
1704 else
1705 kfree_skb(skb);
1706 ppp_recv_unlock(ppp);
1707 }
1708
1709 void
1710 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1711 {
1712 struct channel *pch = chan->ppp;
1713 int proto;
1714
1715 if (!pch) {
1716 kfree_skb(skb);
1717 return;
1718 }
1719
1720 read_lock_bh(&pch->upl);
1721 if (!pskb_may_pull(skb, 2)) {
1722 kfree_skb(skb);
1723 if (pch->ppp) {
1724 ++pch->ppp->dev->stats.rx_length_errors;
1725 ppp_receive_error(pch->ppp);
1726 }
1727 goto done;
1728 }
1729
1730 proto = PPP_PROTO(skb);
1731 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1732 /* put it on the channel queue */
1733 skb_queue_tail(&pch->file.rq, skb);
1734 /* drop old frames if queue too long */
1735 while (pch->file.rq.qlen > PPP_MAX_RQLEN &&
1736 (skb = skb_dequeue(&pch->file.rq)))
1737 kfree_skb(skb);
1738 wake_up_interruptible(&pch->file.rwait);
1739 } else {
1740 ppp_do_recv(pch->ppp, skb, pch);
1741 }
1742
1743 done:
1744 read_unlock_bh(&pch->upl);
1745 }
1746
1747 /* Put a 0-length skb in the receive queue as an error indication */
1748 void
1749 ppp_input_error(struct ppp_channel *chan, int code)
1750 {
1751 struct channel *pch = chan->ppp;
1752 struct sk_buff *skb;
1753
1754 if (!pch)
1755 return;
1756
1757 read_lock_bh(&pch->upl);
1758 if (pch->ppp) {
1759 skb = alloc_skb(0, GFP_ATOMIC);
1760 if (skb) {
1761 skb->len = 0; /* probably unnecessary */
1762 skb->cb[0] = code;
1763 ppp_do_recv(pch->ppp, skb, pch);
1764 }
1765 }
1766 read_unlock_bh(&pch->upl);
1767 }
1768
1769 /*
1770 * We come in here to process a received frame.
1771 * The receive side of the ppp unit is locked.
1772 */
1773 static void
1774 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1775 {
1776 /* note: a 0-length skb is used as an error indication */
1777 if (skb->len > 0) {
1778 skb_checksum_complete_unset(skb);
1779 #ifdef CONFIG_PPP_MULTILINK
1780 /* XXX do channel-level decompression here */
1781 if (PPP_PROTO(skb) == PPP_MP)
1782 ppp_receive_mp_frame(ppp, skb, pch);
1783 else
1784 #endif /* CONFIG_PPP_MULTILINK */
1785 ppp_receive_nonmp_frame(ppp, skb);
1786 } else {
1787 kfree_skb(skb);
1788 ppp_receive_error(ppp);
1789 }
1790 }
1791
1792 static void
1793 ppp_receive_error(struct ppp *ppp)
1794 {
1795 ++ppp->dev->stats.rx_errors;
1796 if (ppp->vj)
1797 slhc_toss(ppp->vj);
1798 }
1799
1800 static void
1801 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1802 {
1803 struct sk_buff *ns;
1804 int proto, len, npi;
1805
1806 /*
1807 * Decompress the frame, if compressed.
1808 * Note that some decompressors need to see uncompressed frames
1809 * that come in as well as compressed frames.
1810 */
1811 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) &&
1812 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1813 skb = ppp_decompress_frame(ppp, skb);
1814
1815 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1816 goto err;
1817
1818 proto = PPP_PROTO(skb);
1819 switch (proto) {
1820 case PPP_VJC_COMP:
1821 /* decompress VJ compressed packets */
1822 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1823 goto err;
1824
1825 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1826 /* copy to a new sk_buff with more tailroom */
1827 ns = dev_alloc_skb(skb->len + 128);
1828 if (!ns) {
1829 netdev_err(ppp->dev, "PPP: no memory "
1830 "(VJ decomp)\n");
1831 goto err;
1832 }
1833 skb_reserve(ns, 2);
1834 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1835 consume_skb(skb);
1836 skb = ns;
1837 }
1838 else
1839 skb->ip_summed = CHECKSUM_NONE;
1840
1841 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1842 if (len <= 0) {
1843 netdev_printk(KERN_DEBUG, ppp->dev,
1844 "PPP: VJ decompression error\n");
1845 goto err;
1846 }
1847 len += 2;
1848 if (len > skb->len)
1849 skb_put(skb, len - skb->len);
1850 else if (len < skb->len)
1851 skb_trim(skb, len);
1852 proto = PPP_IP;
1853 break;
1854
1855 case PPP_VJC_UNCOMP:
1856 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1857 goto err;
1858
1859 /* Until we fix the decompressor need to make sure
1860 * data portion is linear.
1861 */
1862 if (!pskb_may_pull(skb, skb->len))
1863 goto err;
1864
1865 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1866 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n");
1867 goto err;
1868 }
1869 proto = PPP_IP;
1870 break;
1871
1872 case PPP_CCP:
1873 ppp_ccp_peek(ppp, skb, 1);
1874 break;
1875 }
1876
1877 ++ppp->stats64.rx_packets;
1878 ppp->stats64.rx_bytes += skb->len - 2;
1879
1880 npi = proto_to_npindex(proto);
1881 if (npi < 0) {
1882 /* control or unknown frame - pass it to pppd */
1883 skb_queue_tail(&ppp->file.rq, skb);
1884 /* limit queue length by dropping old frames */
1885 while (ppp->file.rq.qlen > PPP_MAX_RQLEN &&
1886 (skb = skb_dequeue(&ppp->file.rq)))
1887 kfree_skb(skb);
1888 /* wake up any process polling or blocking on read */
1889 wake_up_interruptible(&ppp->file.rwait);
1890
1891 } else {
1892 /* network protocol frame - give it to the kernel */
1893
1894 #ifdef CONFIG_PPP_FILTER
1895 /* check if the packet passes the pass and active filters */
1896 /* the filter instructions are constructed assuming
1897 a four-byte PPP header on each packet */
1898 if (ppp->pass_filter || ppp->active_filter) {
1899 if (skb_unclone(skb, GFP_ATOMIC))
1900 goto err;
1901
1902 *skb_push(skb, 2) = 0;
1903 if (ppp->pass_filter &&
1904 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
1905 if (ppp->debug & 1)
1906 netdev_printk(KERN_DEBUG, ppp->dev,
1907 "PPP: inbound frame "
1908 "not passed\n");
1909 kfree_skb(skb);
1910 return;
1911 }
1912 if (!(ppp->active_filter &&
1913 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
1914 ppp->last_recv = jiffies;
1915 __skb_pull(skb, 2);
1916 } else
1917 #endif /* CONFIG_PPP_FILTER */
1918 ppp->last_recv = jiffies;
1919
1920 if ((ppp->dev->flags & IFF_UP) == 0 ||
1921 ppp->npmode[npi] != NPMODE_PASS) {
1922 kfree_skb(skb);
1923 } else {
1924 /* chop off protocol */
1925 skb_pull_rcsum(skb, 2);
1926 skb->dev = ppp->dev;
1927 skb->protocol = htons(npindex_to_ethertype[npi]);
1928 skb_reset_mac_header(skb);
1929 skb_scrub_packet(skb, !net_eq(ppp->ppp_net,
1930 dev_net(ppp->dev)));
1931 netif_rx(skb);
1932 }
1933 }
1934 return;
1935
1936 err:
1937 kfree_skb(skb);
1938 ppp_receive_error(ppp);
1939 }
1940
1941 static struct sk_buff *
1942 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1943 {
1944 int proto = PPP_PROTO(skb);
1945 struct sk_buff *ns;
1946 int len;
1947
1948 /* Until we fix all the decompressor's need to make sure
1949 * data portion is linear.
1950 */
1951 if (!pskb_may_pull(skb, skb->len))
1952 goto err;
1953
1954 if (proto == PPP_COMP) {
1955 int obuff_size;
1956
1957 switch(ppp->rcomp->compress_proto) {
1958 case CI_MPPE:
1959 obuff_size = ppp->mru + PPP_HDRLEN + 1;
1960 break;
1961 default:
1962 obuff_size = ppp->mru + PPP_HDRLEN;
1963 break;
1964 }
1965
1966 ns = dev_alloc_skb(obuff_size);
1967 if (!ns) {
1968 netdev_err(ppp->dev, "ppp_decompress_frame: "
1969 "no memory\n");
1970 goto err;
1971 }
1972 /* the decompressor still expects the A/C bytes in the hdr */
1973 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1974 skb->len + 2, ns->data, obuff_size);
1975 if (len < 0) {
1976 /* Pass the compressed frame to pppd as an
1977 error indication. */
1978 if (len == DECOMP_FATALERROR)
1979 ppp->rstate |= SC_DC_FERROR;
1980 kfree_skb(ns);
1981 goto err;
1982 }
1983
1984 consume_skb(skb);
1985 skb = ns;
1986 skb_put(skb, len);
1987 skb_pull(skb, 2); /* pull off the A/C bytes */
1988
1989 } else {
1990 /* Uncompressed frame - pass to decompressor so it
1991 can update its dictionary if necessary. */
1992 if (ppp->rcomp->incomp)
1993 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1994 skb->len + 2);
1995 }
1996
1997 return skb;
1998
1999 err:
2000 ppp->rstate |= SC_DC_ERROR;
2001 ppp_receive_error(ppp);
2002 return skb;
2003 }
2004
2005 #ifdef CONFIG_PPP_MULTILINK
2006 /*
2007 * Receive a multilink frame.
2008 * We put it on the reconstruction queue and then pull off
2009 * as many completed frames as we can.
2010 */
2011 static void
2012 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
2013 {
2014 u32 mask, seq;
2015 struct channel *ch;
2016 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
2017
2018 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
2019 goto err; /* no good, throw it away */
2020
2021 /* Decode sequence number and begin/end bits */
2022 if (ppp->flags & SC_MP_SHORTSEQ) {
2023 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
2024 mask = 0xfff;
2025 } else {
2026 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
2027 mask = 0xffffff;
2028 }
2029 PPP_MP_CB(skb)->BEbits = skb->data[2];
2030 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
2031
2032 /*
2033 * Do protocol ID decompression on the first fragment of each packet.
2034 */
2035 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1))
2036 *skb_push(skb, 1) = 0;
2037
2038 /*
2039 * Expand sequence number to 32 bits, making it as close
2040 * as possible to ppp->minseq.
2041 */
2042 seq |= ppp->minseq & ~mask;
2043 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
2044 seq += mask + 1;
2045 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
2046 seq -= mask + 1; /* should never happen */
2047 PPP_MP_CB(skb)->sequence = seq;
2048 pch->lastseq = seq;
2049
2050 /*
2051 * If this packet comes before the next one we were expecting,
2052 * drop it.
2053 */
2054 if (seq_before(seq, ppp->nextseq)) {
2055 kfree_skb(skb);
2056 ++ppp->dev->stats.rx_dropped;
2057 ppp_receive_error(ppp);
2058 return;
2059 }
2060
2061 /*
2062 * Reevaluate minseq, the minimum over all channels of the
2063 * last sequence number received on each channel. Because of
2064 * the increasing sequence number rule, we know that any fragment
2065 * before `minseq' which hasn't arrived is never going to arrive.
2066 * The list of channels can't change because we have the receive
2067 * side of the ppp unit locked.
2068 */
2069 list_for_each_entry(ch, &ppp->channels, clist) {
2070 if (seq_before(ch->lastseq, seq))
2071 seq = ch->lastseq;
2072 }
2073 if (seq_before(ppp->minseq, seq))
2074 ppp->minseq = seq;
2075
2076 /* Put the fragment on the reconstruction queue */
2077 ppp_mp_insert(ppp, skb);
2078
2079 /* If the queue is getting long, don't wait any longer for packets
2080 before the start of the queue. */
2081 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
2082 struct sk_buff *mskb = skb_peek(&ppp->mrq);
2083 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence))
2084 ppp->minseq = PPP_MP_CB(mskb)->sequence;
2085 }
2086
2087 /* Pull completed packets off the queue and receive them. */
2088 while ((skb = ppp_mp_reconstruct(ppp))) {
2089 if (pskb_may_pull(skb, 2))
2090 ppp_receive_nonmp_frame(ppp, skb);
2091 else {
2092 ++ppp->dev->stats.rx_length_errors;
2093 kfree_skb(skb);
2094 ppp_receive_error(ppp);
2095 }
2096 }
2097
2098 return;
2099
2100 err:
2101 kfree_skb(skb);
2102 ppp_receive_error(ppp);
2103 }
2104
2105 /*
2106 * Insert a fragment on the MP reconstruction queue.
2107 * The queue is ordered by increasing sequence number.
2108 */
2109 static void
2110 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
2111 {
2112 struct sk_buff *p;
2113 struct sk_buff_head *list = &ppp->mrq;
2114 u32 seq = PPP_MP_CB(skb)->sequence;
2115
2116 /* N.B. we don't need to lock the list lock because we have the
2117 ppp unit receive-side lock. */
2118 skb_queue_walk(list, p) {
2119 if (seq_before(seq, PPP_MP_CB(p)->sequence))
2120 break;
2121 }
2122 __skb_queue_before(list, p, skb);
2123 }
2124
2125 /*
2126 * Reconstruct a packet from the MP fragment queue.
2127 * We go through increasing sequence numbers until we find a
2128 * complete packet, or we get to the sequence number for a fragment
2129 * which hasn't arrived but might still do so.
2130 */
2131 static struct sk_buff *
2132 ppp_mp_reconstruct(struct ppp *ppp)
2133 {
2134 u32 seq = ppp->nextseq;
2135 u32 minseq = ppp->minseq;
2136 struct sk_buff_head *list = &ppp->mrq;
2137 struct sk_buff *p, *tmp;
2138 struct sk_buff *head, *tail;
2139 struct sk_buff *skb = NULL;
2140 int lost = 0, len = 0;
2141
2142 if (ppp->mrru == 0) /* do nothing until mrru is set */
2143 return NULL;
2144 head = list->next;
2145 tail = NULL;
2146 skb_queue_walk_safe(list, p, tmp) {
2147 again:
2148 if (seq_before(PPP_MP_CB(p)->sequence, seq)) {
2149 /* this can't happen, anyway ignore the skb */
2150 netdev_err(ppp->dev, "ppp_mp_reconstruct bad "
2151 "seq %u < %u\n",
2152 PPP_MP_CB(p)->sequence, seq);
2153 __skb_unlink(p, list);
2154 kfree_skb(p);
2155 continue;
2156 }
2157 if (PPP_MP_CB(p)->sequence != seq) {
2158 u32 oldseq;
2159 /* Fragment `seq' is missing. If it is after
2160 minseq, it might arrive later, so stop here. */
2161 if (seq_after(seq, minseq))
2162 break;
2163 /* Fragment `seq' is lost, keep going. */
2164 lost = 1;
2165 oldseq = seq;
2166 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)?
2167 minseq + 1: PPP_MP_CB(p)->sequence;
2168
2169 if (ppp->debug & 1)
2170 netdev_printk(KERN_DEBUG, ppp->dev,
2171 "lost frag %u..%u\n",
2172 oldseq, seq-1);
2173
2174 goto again;
2175 }
2176
2177 /*
2178 * At this point we know that all the fragments from
2179 * ppp->nextseq to seq are either present or lost.
2180 * Also, there are no complete packets in the queue
2181 * that have no missing fragments and end before this
2182 * fragment.
2183 */
2184
2185 /* B bit set indicates this fragment starts a packet */
2186 if (PPP_MP_CB(p)->BEbits & B) {
2187 head = p;
2188 lost = 0;
2189 len = 0;
2190 }
2191
2192 len += p->len;
2193
2194 /* Got a complete packet yet? */
2195 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) &&
2196 (PPP_MP_CB(head)->BEbits & B)) {
2197 if (len > ppp->mrru + 2) {
2198 ++ppp->dev->stats.rx_length_errors;
2199 netdev_printk(KERN_DEBUG, ppp->dev,
2200 "PPP: reconstructed packet"
2201 " is too long (%d)\n", len);
2202 } else {
2203 tail = p;
2204 break;
2205 }
2206 ppp->nextseq = seq + 1;
2207 }
2208
2209 /*
2210 * If this is the ending fragment of a packet,
2211 * and we haven't found a complete valid packet yet,
2212 * we can discard up to and including this fragment.
2213 */
2214 if (PPP_MP_CB(p)->BEbits & E) {
2215 struct sk_buff *tmp2;
2216
2217 skb_queue_reverse_walk_from_safe(list, p, tmp2) {
2218 if (ppp->debug & 1)
2219 netdev_printk(KERN_DEBUG, ppp->dev,
2220 "discarding frag %u\n",
2221 PPP_MP_CB(p)->sequence);
2222 __skb_unlink(p, list);
2223 kfree_skb(p);
2224 }
2225 head = skb_peek(list);
2226 if (!head)
2227 break;
2228 }
2229 ++seq;
2230 }
2231
2232 /* If we have a complete packet, copy it all into one skb. */
2233 if (tail != NULL) {
2234 /* If we have discarded any fragments,
2235 signal a receive error. */
2236 if (PPP_MP_CB(head)->sequence != ppp->nextseq) {
2237 skb_queue_walk_safe(list, p, tmp) {
2238 if (p == head)
2239 break;
2240 if (ppp->debug & 1)
2241 netdev_printk(KERN_DEBUG, ppp->dev,
2242 "discarding frag %u\n",
2243 PPP_MP_CB(p)->sequence);
2244 __skb_unlink(p, list);
2245 kfree_skb(p);
2246 }
2247
2248 if (ppp->debug & 1)
2249 netdev_printk(KERN_DEBUG, ppp->dev,
2250 " missed pkts %u..%u\n",
2251 ppp->nextseq,
2252 PPP_MP_CB(head)->sequence-1);
2253 ++ppp->dev->stats.rx_dropped;
2254 ppp_receive_error(ppp);
2255 }
2256
2257 skb = head;
2258 if (head != tail) {
2259 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list;
2260 p = skb_queue_next(list, head);
2261 __skb_unlink(skb, list);
2262 skb_queue_walk_from_safe(list, p, tmp) {
2263 __skb_unlink(p, list);
2264 *fragpp = p;
2265 p->next = NULL;
2266 fragpp = &p->next;
2267
2268 skb->len += p->len;
2269 skb->data_len += p->len;
2270 skb->truesize += p->truesize;
2271
2272 if (p == tail)
2273 break;
2274 }
2275 } else {
2276 __skb_unlink(skb, list);
2277 }
2278
2279 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1;
2280 }
2281
2282 return skb;
2283 }
2284 #endif /* CONFIG_PPP_MULTILINK */
2285
2286 /*
2287 * Channel interface.
2288 */
2289
2290 /* Create a new, unattached ppp channel. */
2291 int ppp_register_channel(struct ppp_channel *chan)
2292 {
2293 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2294 }
2295
2296 /* Create a new, unattached ppp channel for specified net. */
2297 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
2298 {
2299 struct channel *pch;
2300 struct ppp_net *pn;
2301
2302 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2303 if (!pch)
2304 return -ENOMEM;
2305
2306 pn = ppp_pernet(net);
2307
2308 pch->ppp = NULL;
2309 pch->chan = chan;
2310 pch->chan_net = get_net(net);
2311 chan->ppp = pch;
2312 init_ppp_file(&pch->file, CHANNEL);
2313 pch->file.hdrlen = chan->hdrlen;
2314 #ifdef CONFIG_PPP_MULTILINK
2315 pch->lastseq = -1;
2316 #endif /* CONFIG_PPP_MULTILINK */
2317 init_rwsem(&pch->chan_sem);
2318 spin_lock_init(&pch->downl);
2319 rwlock_init(&pch->upl);
2320
2321 spin_lock_bh(&pn->all_channels_lock);
2322 pch->file.index = ++pn->last_channel_index;
2323 list_add(&pch->list, &pn->new_channels);
2324 atomic_inc(&channel_count);
2325 spin_unlock_bh(&pn->all_channels_lock);
2326
2327 return 0;
2328 }
2329
2330 /*
2331 * Return the index of a channel.
2332 */
2333 int ppp_channel_index(struct ppp_channel *chan)
2334 {
2335 struct channel *pch = chan->ppp;
2336
2337 if (pch)
2338 return pch->file.index;
2339 return -1;
2340 }
2341
2342 /*
2343 * Return the PPP unit number to which a channel is connected.
2344 */
2345 int ppp_unit_number(struct ppp_channel *chan)
2346 {
2347 struct channel *pch = chan->ppp;
2348 int unit = -1;
2349
2350 if (pch) {
2351 read_lock_bh(&pch->upl);
2352 if (pch->ppp)
2353 unit = pch->ppp->file.index;
2354 read_unlock_bh(&pch->upl);
2355 }
2356 return unit;
2357 }
2358
2359 /*
2360 * Return the PPP device interface name of a channel.
2361 */
2362 char *ppp_dev_name(struct ppp_channel *chan)
2363 {
2364 struct channel *pch = chan->ppp;
2365 char *name = NULL;
2366
2367 if (pch) {
2368 read_lock_bh(&pch->upl);
2369 if (pch->ppp && pch->ppp->dev)
2370 name = pch->ppp->dev->name;
2371 read_unlock_bh(&pch->upl);
2372 }
2373 return name;
2374 }
2375
2376
2377 /*
2378 * Disconnect a channel from the generic layer.
2379 * This must be called in process context.
2380 */
2381 void
2382 ppp_unregister_channel(struct ppp_channel *chan)
2383 {
2384 struct channel *pch = chan->ppp;
2385 struct ppp_net *pn;
2386
2387 if (!pch)
2388 return; /* should never happen */
2389
2390 chan->ppp = NULL;
2391
2392 /*
2393 * This ensures that we have returned from any calls into the
2394 * the channel's start_xmit or ioctl routine before we proceed.
2395 */
2396 down_write(&pch->chan_sem);
2397 spin_lock_bh(&pch->downl);
2398 pch->chan = NULL;
2399 spin_unlock_bh(&pch->downl);
2400 up_write(&pch->chan_sem);
2401 ppp_disconnect_channel(pch);
2402
2403 pn = ppp_pernet(pch->chan_net);
2404 spin_lock_bh(&pn->all_channels_lock);
2405 list_del(&pch->list);
2406 spin_unlock_bh(&pn->all_channels_lock);
2407 put_net(pch->chan_net);
2408 pch->chan_net = NULL;
2409
2410 pch->file.dead = 1;
2411 wake_up_interruptible(&pch->file.rwait);
2412 if (atomic_dec_and_test(&pch->file.refcnt))
2413 ppp_destroy_channel(pch);
2414 }
2415
2416 /*
2417 * Callback from a channel when it can accept more to transmit.
2418 * This should be called at BH/softirq level, not interrupt level.
2419 */
2420 void
2421 ppp_output_wakeup(struct ppp_channel *chan)
2422 {
2423 struct channel *pch = chan->ppp;
2424
2425 if (!pch)
2426 return;
2427 ppp_channel_push(pch);
2428 }
2429
2430 /*
2431 * Compression control.
2432 */
2433
2434 /* Process the PPPIOCSCOMPRESS ioctl. */
2435 static int
2436 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2437 {
2438 int err;
2439 struct compressor *cp, *ocomp;
2440 struct ppp_option_data data;
2441 void *state, *ostate;
2442 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2443
2444 err = -EFAULT;
2445 if (copy_from_user(&data, (void __user *) arg, sizeof(data)))
2446 goto out;
2447 if (data.length > CCP_MAX_OPTION_LENGTH)
2448 goto out;
2449 if (copy_from_user(ccp_option, (void __user *) data.ptr, data.length))
2450 goto out;
2451
2452 err = -EINVAL;
2453 if (data.length < 2 || ccp_option[1] < 2 || ccp_option[1] > data.length)
2454 goto out;
2455
2456 cp = try_then_request_module(
2457 find_compressor(ccp_option[0]),
2458 "ppp-compress-%d", ccp_option[0]);
2459 if (!cp)
2460 goto out;
2461
2462 err = -ENOBUFS;
2463 if (data.transmit) {
2464 state = cp->comp_alloc(ccp_option, data.length);
2465 if (state) {
2466 ppp_xmit_lock(ppp);
2467 ppp->xstate &= ~SC_COMP_RUN;
2468 ocomp = ppp->xcomp;
2469 ostate = ppp->xc_state;
2470 ppp->xcomp = cp;
2471 ppp->xc_state = state;
2472 ppp_xmit_unlock(ppp);
2473 if (ostate) {
2474 ocomp->comp_free(ostate);
2475 module_put(ocomp->owner);
2476 }
2477 err = 0;
2478 } else
2479 module_put(cp->owner);
2480
2481 } else {
2482 state = cp->decomp_alloc(ccp_option, data.length);
2483 if (state) {
2484 ppp_recv_lock(ppp);
2485 ppp->rstate &= ~SC_DECOMP_RUN;
2486 ocomp = ppp->rcomp;
2487 ostate = ppp->rc_state;
2488 ppp->rcomp = cp;
2489 ppp->rc_state = state;
2490 ppp_recv_unlock(ppp);
2491 if (ostate) {
2492 ocomp->decomp_free(ostate);
2493 module_put(ocomp->owner);
2494 }
2495 err = 0;
2496 } else
2497 module_put(cp->owner);
2498 }
2499
2500 out:
2501 return err;
2502 }
2503
2504 /*
2505 * Look at a CCP packet and update our state accordingly.
2506 * We assume the caller has the xmit or recv path locked.
2507 */
2508 static void
2509 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2510 {
2511 unsigned char *dp;
2512 int len;
2513
2514 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2515 return; /* no header */
2516 dp = skb->data + 2;
2517
2518 switch (CCP_CODE(dp)) {
2519 case CCP_CONFREQ:
2520
2521 /* A ConfReq starts negotiation of compression
2522 * in one direction of transmission,
2523 * and hence brings it down...but which way?
2524 *
2525 * Remember:
2526 * A ConfReq indicates what the sender would like to receive
2527 */
2528 if(inbound)
2529 /* He is proposing what I should send */
2530 ppp->xstate &= ~SC_COMP_RUN;
2531 else
2532 /* I am proposing to what he should send */
2533 ppp->rstate &= ~SC_DECOMP_RUN;
2534
2535 break;
2536
2537 case CCP_TERMREQ:
2538 case CCP_TERMACK:
2539 /*
2540 * CCP is going down, both directions of transmission
2541 */
2542 ppp->rstate &= ~SC_DECOMP_RUN;
2543 ppp->xstate &= ~SC_COMP_RUN;
2544 break;
2545
2546 case CCP_CONFACK:
2547 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2548 break;
2549 len = CCP_LENGTH(dp);
2550 if (!pskb_may_pull(skb, len + 2))
2551 return; /* too short */
2552 dp += CCP_HDRLEN;
2553 len -= CCP_HDRLEN;
2554 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2555 break;
2556 if (inbound) {
2557 /* we will start receiving compressed packets */
2558 if (!ppp->rc_state)
2559 break;
2560 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2561 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2562 ppp->rstate |= SC_DECOMP_RUN;
2563 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2564 }
2565 } else {
2566 /* we will soon start sending compressed packets */
2567 if (!ppp->xc_state)
2568 break;
2569 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2570 ppp->file.index, 0, ppp->debug))
2571 ppp->xstate |= SC_COMP_RUN;
2572 }
2573 break;
2574
2575 case CCP_RESETACK:
2576 /* reset the [de]compressor */
2577 if ((ppp->flags & SC_CCP_UP) == 0)
2578 break;
2579 if (inbound) {
2580 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2581 ppp->rcomp->decomp_reset(ppp->rc_state);
2582 ppp->rstate &= ~SC_DC_ERROR;
2583 }
2584 } else {
2585 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2586 ppp->xcomp->comp_reset(ppp->xc_state);
2587 }
2588 break;
2589 }
2590 }
2591
2592 /* Free up compression resources. */
2593 static void
2594 ppp_ccp_closed(struct ppp *ppp)
2595 {
2596 void *xstate, *rstate;
2597 struct compressor *xcomp, *rcomp;
2598
2599 ppp_lock(ppp);
2600 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2601 ppp->xstate = 0;
2602 xcomp = ppp->xcomp;
2603 xstate = ppp->xc_state;
2604 ppp->xc_state = NULL;
2605 ppp->rstate = 0;
2606 rcomp = ppp->rcomp;
2607 rstate = ppp->rc_state;
2608 ppp->rc_state = NULL;
2609 ppp_unlock(ppp);
2610
2611 if (xstate) {
2612 xcomp->comp_free(xstate);
2613 module_put(xcomp->owner);
2614 }
2615 if (rstate) {
2616 rcomp->decomp_free(rstate);
2617 module_put(rcomp->owner);
2618 }
2619 }
2620
2621 /* List of compressors. */
2622 static LIST_HEAD(compressor_list);
2623 static DEFINE_SPINLOCK(compressor_list_lock);
2624
2625 struct compressor_entry {
2626 struct list_head list;
2627 struct compressor *comp;
2628 };
2629
2630 static struct compressor_entry *
2631 find_comp_entry(int proto)
2632 {
2633 struct compressor_entry *ce;
2634
2635 list_for_each_entry(ce, &compressor_list, list) {
2636 if (ce->comp->compress_proto == proto)
2637 return ce;
2638 }
2639 return NULL;
2640 }
2641
2642 /* Register a compressor */
2643 int
2644 ppp_register_compressor(struct compressor *cp)
2645 {
2646 struct compressor_entry *ce;
2647 int ret;
2648 spin_lock(&compressor_list_lock);
2649 ret = -EEXIST;
2650 if (find_comp_entry(cp->compress_proto))
2651 goto out;
2652 ret = -ENOMEM;
2653 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2654 if (!ce)
2655 goto out;
2656 ret = 0;
2657 ce->comp = cp;
2658 list_add(&ce->list, &compressor_list);
2659 out:
2660 spin_unlock(&compressor_list_lock);
2661 return ret;
2662 }
2663
2664 /* Unregister a compressor */
2665 void
2666 ppp_unregister_compressor(struct compressor *cp)
2667 {
2668 struct compressor_entry *ce;
2669
2670 spin_lock(&compressor_list_lock);
2671 ce = find_comp_entry(cp->compress_proto);
2672 if (ce && ce->comp == cp) {
2673 list_del(&ce->list);
2674 kfree(ce);
2675 }
2676 spin_unlock(&compressor_list_lock);
2677 }
2678
2679 /* Find a compressor. */
2680 static struct compressor *
2681 find_compressor(int type)
2682 {
2683 struct compressor_entry *ce;
2684 struct compressor *cp = NULL;
2685
2686 spin_lock(&compressor_list_lock);
2687 ce = find_comp_entry(type);
2688 if (ce) {
2689 cp = ce->comp;
2690 if (!try_module_get(cp->owner))
2691 cp = NULL;
2692 }
2693 spin_unlock(&compressor_list_lock);
2694 return cp;
2695 }
2696
2697 /*
2698 * Miscelleneous stuff.
2699 */
2700
2701 static void
2702 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2703 {
2704 struct slcompress *vj = ppp->vj;
2705
2706 memset(st, 0, sizeof(*st));
2707 st->p.ppp_ipackets = ppp->stats64.rx_packets;
2708 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2709 st->p.ppp_ibytes = ppp->stats64.rx_bytes;
2710 st->p.ppp_opackets = ppp->stats64.tx_packets;
2711 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2712 st->p.ppp_obytes = ppp->stats64.tx_bytes;
2713 if (!vj)
2714 return;
2715 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2716 st->vj.vjs_compressed = vj->sls_o_compressed;
2717 st->vj.vjs_searches = vj->sls_o_searches;
2718 st->vj.vjs_misses = vj->sls_o_misses;
2719 st->vj.vjs_errorin = vj->sls_i_error;
2720 st->vj.vjs_tossed = vj->sls_i_tossed;
2721 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2722 st->vj.vjs_compressedin = vj->sls_i_compressed;
2723 }
2724
2725 /*
2726 * Stuff for handling the lists of ppp units and channels
2727 * and for initialization.
2728 */
2729
2730 /*
2731 * Create a new ppp interface unit. Fails if it can't allocate memory
2732 * or if there is already a unit with the requested number.
2733 * unit == -1 means allocate a new number.
2734 */
2735 static struct ppp *ppp_create_interface(struct net *net, int unit,
2736 struct file *file, int *retp)
2737 {
2738 struct ppp *ppp;
2739 struct ppp_net *pn;
2740 struct net_device *dev = NULL;
2741 int ret = -ENOMEM;
2742 int i;
2743
2744 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_ENUM, ppp_setup);
2745 if (!dev)
2746 goto out1;
2747
2748 pn = ppp_pernet(net);
2749
2750 ppp = netdev_priv(dev);
2751 ppp->dev = dev;
2752 ppp->mru = PPP_MRU;
2753 init_ppp_file(&ppp->file, INTERFACE);
2754 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2755 ppp->owner = file;
2756 for (i = 0; i < NUM_NP; ++i)
2757 ppp->npmode[i] = NPMODE_PASS;
2758 INIT_LIST_HEAD(&ppp->channels);
2759 spin_lock_init(&ppp->rlock);
2760 spin_lock_init(&ppp->wlock);
2761 #ifdef CONFIG_PPP_MULTILINK
2762 ppp->minseq = -1;
2763 skb_queue_head_init(&ppp->mrq);
2764 #endif /* CONFIG_PPP_MULTILINK */
2765 #ifdef CONFIG_PPP_FILTER
2766 ppp->pass_filter = NULL;
2767 ppp->active_filter = NULL;
2768 #endif /* CONFIG_PPP_FILTER */
2769
2770 /*
2771 * drum roll: don't forget to set
2772 * the net device is belong to
2773 */
2774 dev_net_set(dev, net);
2775
2776 rtnl_lock();
2777 mutex_lock(&pn->all_ppp_mutex);
2778
2779 if (unit < 0) {
2780 unit = unit_get(&pn->units_idr, ppp);
2781 if (unit < 0) {
2782 ret = unit;
2783 goto out2;
2784 }
2785 } else {
2786 ret = -EEXIST;
2787 if (unit_find(&pn->units_idr, unit))
2788 goto out2; /* unit already exists */
2789 /*
2790 * if caller need a specified unit number
2791 * lets try to satisfy him, otherwise --
2792 * he should better ask us for new unit number
2793 *
2794 * NOTE: yes I know that returning EEXIST it's not
2795 * fair but at least pppd will ask us to allocate
2796 * new unit in this case so user is happy :)
2797 */
2798 unit = unit_set(&pn->units_idr, ppp, unit);
2799 if (unit < 0)
2800 goto out2;
2801 }
2802
2803 /* Initialize the new ppp unit */
2804 ppp->file.index = unit;
2805 sprintf(dev->name, "ppp%d", unit);
2806
2807 ret = register_netdevice(dev);
2808 if (ret != 0) {
2809 unit_put(&pn->units_idr, unit);
2810 netdev_err(ppp->dev, "PPP: couldn't register device %s (%d)\n",
2811 dev->name, ret);
2812 goto out2;
2813 }
2814
2815 ppp->ppp_net = net;
2816
2817 atomic_inc(&ppp_unit_count);
2818 mutex_unlock(&pn->all_ppp_mutex);
2819 rtnl_unlock();
2820
2821 *retp = 0;
2822 return ppp;
2823
2824 out2:
2825 mutex_unlock(&pn->all_ppp_mutex);
2826 rtnl_unlock();
2827 free_netdev(dev);
2828 out1:
2829 *retp = ret;
2830 return NULL;
2831 }
2832
2833 /*
2834 * Initialize a ppp_file structure.
2835 */
2836 static void
2837 init_ppp_file(struct ppp_file *pf, int kind)
2838 {
2839 pf->kind = kind;
2840 skb_queue_head_init(&pf->xq);
2841 skb_queue_head_init(&pf->rq);
2842 atomic_set(&pf->refcnt, 1);
2843 init_waitqueue_head(&pf->rwait);
2844 }
2845
2846 /*
2847 * Free the memory used by a ppp unit. This is only called once
2848 * there are no channels connected to the unit and no file structs
2849 * that reference the unit.
2850 */
2851 static void ppp_destroy_interface(struct ppp *ppp)
2852 {
2853 atomic_dec(&ppp_unit_count);
2854
2855 if (!ppp->file.dead || ppp->n_channels) {
2856 /* "can't happen" */
2857 netdev_err(ppp->dev, "ppp: destroying ppp struct %p "
2858 "but dead=%d n_channels=%d !\n",
2859 ppp, ppp->file.dead, ppp->n_channels);
2860 return;
2861 }
2862
2863 ppp_ccp_closed(ppp);
2864 if (ppp->vj) {
2865 slhc_free(ppp->vj);
2866 ppp->vj = NULL;
2867 }
2868 skb_queue_purge(&ppp->file.xq);
2869 skb_queue_purge(&ppp->file.rq);
2870 #ifdef CONFIG_PPP_MULTILINK
2871 skb_queue_purge(&ppp->mrq);
2872 #endif /* CONFIG_PPP_MULTILINK */
2873 #ifdef CONFIG_PPP_FILTER
2874 if (ppp->pass_filter) {
2875 bpf_prog_destroy(ppp->pass_filter);
2876 ppp->pass_filter = NULL;
2877 }
2878
2879 if (ppp->active_filter) {
2880 bpf_prog_destroy(ppp->active_filter);
2881 ppp->active_filter = NULL;
2882 }
2883 #endif /* CONFIG_PPP_FILTER */
2884
2885 kfree_skb(ppp->xmit_pending);
2886
2887 free_netdev(ppp->dev);
2888 }
2889
2890 /*
2891 * Locate an existing ppp unit.
2892 * The caller should have locked the all_ppp_mutex.
2893 */
2894 static struct ppp *
2895 ppp_find_unit(struct ppp_net *pn, int unit)
2896 {
2897 return unit_find(&pn->units_idr, unit);
2898 }
2899
2900 /*
2901 * Locate an existing ppp channel.
2902 * The caller should have locked the all_channels_lock.
2903 * First we look in the new_channels list, then in the
2904 * all_channels list. If found in the new_channels list,
2905 * we move it to the all_channels list. This is for speed
2906 * when we have a lot of channels in use.
2907 */
2908 static struct channel *
2909 ppp_find_channel(struct ppp_net *pn, int unit)
2910 {
2911 struct channel *pch;
2912
2913 list_for_each_entry(pch, &pn->new_channels, list) {
2914 if (pch->file.index == unit) {
2915 list_move(&pch->list, &pn->all_channels);
2916 return pch;
2917 }
2918 }
2919
2920 list_for_each_entry(pch, &pn->all_channels, list) {
2921 if (pch->file.index == unit)
2922 return pch;
2923 }
2924
2925 return NULL;
2926 }
2927
2928 /*
2929 * Connect a PPP channel to a PPP interface unit.
2930 */
2931 static int
2932 ppp_connect_channel(struct channel *pch, int unit)
2933 {
2934 struct ppp *ppp;
2935 struct ppp_net *pn;
2936 int ret = -ENXIO;
2937 int hdrlen;
2938
2939 pn = ppp_pernet(pch->chan_net);
2940
2941 mutex_lock(&pn->all_ppp_mutex);
2942 ppp = ppp_find_unit(pn, unit);
2943 if (!ppp)
2944 goto out;
2945 write_lock_bh(&pch->upl);
2946 ret = -EINVAL;
2947 if (pch->ppp)
2948 goto outl;
2949
2950 ppp_lock(ppp);
2951 if (pch->file.hdrlen > ppp->file.hdrlen)
2952 ppp->file.hdrlen = pch->file.hdrlen;
2953 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2954 if (hdrlen > ppp->dev->hard_header_len)
2955 ppp->dev->hard_header_len = hdrlen;
2956 list_add_tail(&pch->clist, &ppp->channels);
2957 ++ppp->n_channels;
2958 pch->ppp = ppp;
2959 atomic_inc(&ppp->file.refcnt);
2960 ppp_unlock(ppp);
2961 ret = 0;
2962
2963 outl:
2964 write_unlock_bh(&pch->upl);
2965 out:
2966 mutex_unlock(&pn->all_ppp_mutex);
2967 return ret;
2968 }
2969
2970 /*
2971 * Disconnect a channel from its ppp unit.
2972 */
2973 static int
2974 ppp_disconnect_channel(struct channel *pch)
2975 {
2976 struct ppp *ppp;
2977 int err = -EINVAL;
2978
2979 write_lock_bh(&pch->upl);
2980 ppp = pch->ppp;
2981 pch->ppp = NULL;
2982 write_unlock_bh(&pch->upl);
2983 if (ppp) {
2984 /* remove it from the ppp unit's list */
2985 ppp_lock(ppp);
2986 list_del(&pch->clist);
2987 if (--ppp->n_channels == 0)
2988 wake_up_interruptible(&ppp->file.rwait);
2989 ppp_unlock(ppp);
2990 if (atomic_dec_and_test(&ppp->file.refcnt))
2991 ppp_destroy_interface(ppp);
2992 err = 0;
2993 }
2994 return err;
2995 }
2996
2997 /*
2998 * Free up the resources used by a ppp channel.
2999 */
3000 static void ppp_destroy_channel(struct channel *pch)
3001 {
3002 atomic_dec(&channel_count);
3003
3004 if (!pch->file.dead) {
3005 /* "can't happen" */
3006 pr_err("ppp: destroying undead channel %p !\n", pch);
3007 return;
3008 }
3009 skb_queue_purge(&pch->file.xq);
3010 skb_queue_purge(&pch->file.rq);
3011 kfree(pch);
3012 }
3013
3014 static void __exit ppp_cleanup(void)
3015 {
3016 /* should never happen */
3017 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
3018 pr_err("PPP: removing module but units remain!\n");
3019 unregister_chrdev(PPP_MAJOR, "ppp");
3020 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
3021 class_destroy(ppp_class);
3022 unregister_pernet_device(&ppp_net_ops);
3023 }
3024
3025 /*
3026 * Units handling. Caller must protect concurrent access
3027 * by holding all_ppp_mutex
3028 */
3029
3030 /* associate pointer with specified number */
3031 static int unit_set(struct idr *p, void *ptr, int n)
3032 {
3033 int unit;
3034
3035 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL);
3036 if (unit == -ENOSPC)
3037 unit = -EINVAL;
3038 return unit;
3039 }
3040
3041 /* get new free unit number and associate pointer with it */
3042 static int unit_get(struct idr *p, void *ptr)
3043 {
3044 return idr_alloc(p, ptr, 0, 0, GFP_KERNEL);
3045 }
3046
3047 /* put unit number back to a pool */
3048 static void unit_put(struct idr *p, int n)
3049 {
3050 idr_remove(p, n);
3051 }
3052
3053 /* get pointer associated with the number */
3054 static void *unit_find(struct idr *p, int n)
3055 {
3056 return idr_find(p, n);
3057 }
3058
3059 /* Module/initialization stuff */
3060
3061 module_init(ppp_init);
3062 module_exit(ppp_cleanup);
3063
3064 EXPORT_SYMBOL(ppp_register_net_channel);
3065 EXPORT_SYMBOL(ppp_register_channel);
3066 EXPORT_SYMBOL(ppp_unregister_channel);
3067 EXPORT_SYMBOL(ppp_channel_index);
3068 EXPORT_SYMBOL(ppp_unit_number);
3069 EXPORT_SYMBOL(ppp_dev_name);
3070 EXPORT_SYMBOL(ppp_input);
3071 EXPORT_SYMBOL(ppp_input_error);
3072 EXPORT_SYMBOL(ppp_output_wakeup);
3073 EXPORT_SYMBOL(ppp_register_compressor);
3074 EXPORT_SYMBOL(ppp_unregister_compressor);
3075 MODULE_LICENSE("GPL");
3076 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
3077 MODULE_ALIAS("devname:ppp");
Linux with added FPC-III support