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