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