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Merge remote-tracking branch 'omap_dss2/for-next'
[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 <linux/file.h>
50 #include <asm/unaligned.h>
51 #include <net/slhc_vj.h>
52 #include <linux/atomic.h>
53
54 #include <linux/nsproxy.h>
55 #include <net/net_namespace.h>
56 #include <net/netns/generic.h>
57
58 #define PPP_VERSION "2.4.2"
59
60 /*
61 * Network protocols we support.
62 */
63 #define NP_IP 0 /* Internet Protocol V4 */
64 #define NP_IPV6 1 /* Internet Protocol V6 */
65 #define NP_IPX 2 /* IPX protocol */
66 #define NP_AT 3 /* Appletalk protocol */
67 #define NP_MPLS_UC 4 /* MPLS unicast */
68 #define NP_MPLS_MC 5 /* MPLS multicast */
69 #define NUM_NP 6 /* Number of NPs. */
70
71 #define MPHDRLEN 6 /* multilink protocol header length */
72 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */
73
74 /*
75 * An instance of /dev/ppp can be associated with either a ppp
76 * interface unit or a ppp channel. In both cases, file->private_data
77 * points to one of these.
78 */
79 struct ppp_file {
80 enum {
81 INTERFACE=1, CHANNEL
82 } kind;
83 struct sk_buff_head xq; /* pppd transmit queue */
84 struct sk_buff_head rq; /* receive queue for pppd */
85 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */
86 atomic_t refcnt; /* # refs (incl /dev/ppp attached) */
87 int hdrlen; /* space to leave for headers */
88 int index; /* interface unit / channel number */
89 int dead; /* unit/channel has been shut down */
90 };
91
92 #define PF_TO_X(pf, X) container_of(pf, X, file)
93
94 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
95 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
96
97 /*
98 * Data structure to hold primary network stats for which
99 * we want to use 64 bit storage. Other network stats
100 * are stored in dev->stats of the ppp strucute.
101 */
102 struct ppp_link_stats {
103 u64 rx_packets;
104 u64 tx_packets;
105 u64 rx_bytes;
106 u64 tx_bytes;
107 };
108
109 /*
110 * Data structure describing one ppp unit.
111 * A ppp unit corresponds to a ppp network interface device
112 * and represents a multilink bundle.
113 * It can have 0 or more ppp channels connected to it.
114 */
115 struct ppp {
116 struct ppp_file file; /* stuff for read/write/poll 0 */
117 struct file *owner; /* file that owns this unit 48 */
118 struct list_head channels; /* list of attached channels 4c */
119 int n_channels; /* how many channels are attached 54 */
120 spinlock_t rlock; /* lock for receive side 58 */
121 spinlock_t wlock; /* lock for transmit side 5c */
122 int mru; /* max receive unit 60 */
123 unsigned int flags; /* control bits 64 */
124 unsigned int xstate; /* transmit state bits 68 */
125 unsigned int rstate; /* receive state bits 6c */
126 int debug; /* debug flags 70 */
127 struct slcompress *vj; /* state for VJ header compression */
128 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
129 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
130 struct compressor *xcomp; /* transmit packet compressor 8c */
131 void *xc_state; /* its internal state 90 */
132 struct compressor *rcomp; /* receive decompressor 94 */
133 void *rc_state; /* its internal state 98 */
134 unsigned long last_xmit; /* jiffies when last pkt sent 9c */
135 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
136 struct net_device *dev; /* network interface device a4 */
137 int closing; /* is device closing down? a8 */
138 #ifdef CONFIG_PPP_MULTILINK
139 int nxchan; /* next channel to send something on */
140 u32 nxseq; /* next sequence number to send */
141 int mrru; /* MP: max reconst. receive unit */
142 u32 nextseq; /* MP: seq no of next packet */
143 u32 minseq; /* MP: min of most recent seqnos */
144 struct sk_buff_head mrq; /* MP: receive reconstruction queue */
145 #endif /* CONFIG_PPP_MULTILINK */
146 #ifdef CONFIG_PPP_FILTER
147 struct bpf_prog *pass_filter; /* filter for packets to pass */
148 struct bpf_prog *active_filter; /* filter for pkts to reset idle */
149 #endif /* CONFIG_PPP_FILTER */
150 struct net *ppp_net; /* the net we belong to */
151 struct ppp_link_stats stats64; /* 64 bit network stats */
152 };
153
154 /*
155 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
156 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
157 * SC_MUST_COMP
158 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
159 * Bits in xstate: SC_COMP_RUN
160 */
161 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
162 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
163 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
164
165 /*
166 * Private data structure for each channel.
167 * This includes the data structure used for multilink.
168 */
169 struct channel {
170 struct ppp_file file; /* stuff for read/write/poll */
171 struct list_head list; /* link in all/new_channels list */
172 struct ppp_channel *chan; /* public channel data structure */
173 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
174 spinlock_t downl; /* protects `chan', file.xq dequeue */
175 struct ppp *ppp; /* ppp unit we're connected to */
176 struct net *chan_net; /* the net channel belongs to */
177 struct list_head clist; /* link in list of channels per unit */
178 rwlock_t upl; /* protects `ppp' */
179 #ifdef CONFIG_PPP_MULTILINK
180 u8 avail; /* flag used in multilink stuff */
181 u8 had_frag; /* >= 1 fragments have been sent */
182 u32 lastseq; /* MP: last sequence # received */
183 int speed; /* speed of the corresponding ppp channel*/
184 #endif /* CONFIG_PPP_MULTILINK */
185 };
186
187 struct ppp_config {
188 struct file *file;
189 s32 unit;
190 bool ifname_is_set;
191 };
192
193 /*
194 * SMP locking issues:
195 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
196 * list and the ppp.n_channels field, you need to take both locks
197 * before you modify them.
198 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
199 * channel.downl.
200 */
201
202 static DEFINE_MUTEX(ppp_mutex);
203 static atomic_t ppp_unit_count = ATOMIC_INIT(0);
204 static atomic_t channel_count = ATOMIC_INIT(0);
205
206 /* per-net private data for this module */
207 static int ppp_net_id __read_mostly;
208 struct ppp_net {
209 /* units to ppp mapping */
210 struct idr units_idr;
211
212 /*
213 * all_ppp_mutex protects the units_idr mapping.
214 * It also ensures that finding a ppp unit in the units_idr
215 * map and updating its file.refcnt field is atomic.
216 */
217 struct mutex all_ppp_mutex;
218
219 /* channels */
220 struct list_head all_channels;
221 struct list_head new_channels;
222 int last_channel_index;
223
224 /*
225 * all_channels_lock protects all_channels and
226 * last_channel_index, and the atomicity of find
227 * a channel and updating its file.refcnt field.
228 */
229 spinlock_t all_channels_lock;
230 };
231
232 /* Get the PPP protocol number from a skb */
233 #define PPP_PROTO(skb) get_unaligned_be16((skb)->data)
234
235 /* We limit the length of ppp->file.rq to this (arbitrary) value */
236 #define PPP_MAX_RQLEN 32
237
238 /*
239 * Maximum number of multilink fragments queued up.
240 * This has to be large enough to cope with the maximum latency of
241 * the slowest channel relative to the others. Strictly it should
242 * depend on the number of channels and their characteristics.
243 */
244 #define PPP_MP_MAX_QLEN 128
245
246 /* Multilink header bits. */
247 #define B 0x80 /* this fragment begins a packet */
248 #define E 0x40 /* this fragment ends a packet */
249
250 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */
251 #define seq_before(a, b) ((s32)((a) - (b)) < 0)
252 #define seq_after(a, b) ((s32)((a) - (b)) > 0)
253
254 /* Prototypes. */
255 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
256 struct file *file, unsigned int cmd, unsigned long arg);
257 static void ppp_xmit_process(struct ppp *ppp);
258 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
259 static void ppp_push(struct ppp *ppp);
260 static void ppp_channel_push(struct channel *pch);
261 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
262 struct channel *pch);
263 static void ppp_receive_error(struct ppp *ppp);
264 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
265 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
266 struct sk_buff *skb);
267 #ifdef CONFIG_PPP_MULTILINK
268 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
269 struct channel *pch);
270 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
271 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
272 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
273 #endif /* CONFIG_PPP_MULTILINK */
274 static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
275 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
276 static void ppp_ccp_closed(struct ppp *ppp);
277 static struct compressor *find_compressor(int type);
278 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
279 static int ppp_create_interface(struct net *net, struct file *file, int *unit);
280 static void init_ppp_file(struct ppp_file *pf, int kind);
281 static void ppp_destroy_interface(struct ppp *ppp);
282 static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit);
283 static struct channel *ppp_find_channel(struct ppp_net *pn, int unit);
284 static int ppp_connect_channel(struct channel *pch, int unit);
285 static int ppp_disconnect_channel(struct channel *pch);
286 static void ppp_destroy_channel(struct channel *pch);
287 static int unit_get(struct idr *p, void *ptr);
288 static int unit_set(struct idr *p, void *ptr, int n);
289 static void unit_put(struct idr *p, int n);
290 static void *unit_find(struct idr *p, int n);
291 static void ppp_setup(struct net_device *dev);
292
293 static const struct net_device_ops ppp_netdev_ops;
294
295 static struct class *ppp_class;
296
297 /* per net-namespace data */
298 static inline struct ppp_net *ppp_pernet(struct net *net)
299 {
300 BUG_ON(!net);
301
302 return net_generic(net, ppp_net_id);
303 }
304
305 /* Translates a PPP protocol number to a NP index (NP == network protocol) */
306 static inline int proto_to_npindex(int proto)
307 {
308 switch (proto) {
309 case PPP_IP:
310 return NP_IP;
311 case PPP_IPV6:
312 return NP_IPV6;
313 case PPP_IPX:
314 return NP_IPX;
315 case PPP_AT:
316 return NP_AT;
317 case PPP_MPLS_UC:
318 return NP_MPLS_UC;
319 case PPP_MPLS_MC:
320 return NP_MPLS_MC;
321 }
322 return -EINVAL;
323 }
324
325 /* Translates an NP index into a PPP protocol number */
326 static const int npindex_to_proto[NUM_NP] = {
327 PPP_IP,
328 PPP_IPV6,
329 PPP_IPX,
330 PPP_AT,
331 PPP_MPLS_UC,
332 PPP_MPLS_MC,
333 };
334
335 /* Translates an ethertype into an NP index */
336 static inline int ethertype_to_npindex(int ethertype)
337 {
338 switch (ethertype) {
339 case ETH_P_IP:
340 return NP_IP;
341 case ETH_P_IPV6:
342 return NP_IPV6;
343 case ETH_P_IPX:
344 return NP_IPX;
345 case ETH_P_PPPTALK:
346 case ETH_P_ATALK:
347 return NP_AT;
348 case ETH_P_MPLS_UC:
349 return NP_MPLS_UC;
350 case ETH_P_MPLS_MC:
351 return NP_MPLS_MC;
352 }
353 return -1;
354 }
355
356 /* Translates an NP index into an ethertype */
357 static const int npindex_to_ethertype[NUM_NP] = {
358 ETH_P_IP,
359 ETH_P_IPV6,
360 ETH_P_IPX,
361 ETH_P_PPPTALK,
362 ETH_P_MPLS_UC,
363 ETH_P_MPLS_MC,
364 };
365
366 /*
367 * Locking shorthand.
368 */
369 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
370 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
371 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
372 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
373 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
374 ppp_recv_lock(ppp); } while (0)
375 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
376 ppp_xmit_unlock(ppp); } while (0)
377
378 /*
379 * /dev/ppp device routines.
380 * The /dev/ppp device is used by pppd to control the ppp unit.
381 * It supports the read, write, ioctl and poll functions.
382 * Open instances of /dev/ppp can be in one of three states:
383 * unattached, attached to a ppp unit, or attached to a ppp channel.
384 */
385 static int ppp_open(struct inode *inode, struct file *file)
386 {
387 /*
388 * This could (should?) be enforced by the permissions on /dev/ppp.
389 */
390 if (!capable(CAP_NET_ADMIN))
391 return -EPERM;
392 return 0;
393 }
394
395 static int ppp_release(struct inode *unused, struct file *file)
396 {
397 struct ppp_file *pf = file->private_data;
398 struct ppp *ppp;
399
400 if (pf) {
401 file->private_data = NULL;
402 if (pf->kind == INTERFACE) {
403 ppp = PF_TO_PPP(pf);
404 rtnl_lock();
405 if (file == ppp->owner)
406 unregister_netdevice(ppp->dev);
407 rtnl_unlock();
408 }
409 if (atomic_dec_and_test(&pf->refcnt)) {
410 switch (pf->kind) {
411 case INTERFACE:
412 ppp_destroy_interface(PF_TO_PPP(pf));
413 break;
414 case CHANNEL:
415 ppp_destroy_channel(PF_TO_CHANNEL(pf));
416 break;
417 }
418 }
419 }
420 return 0;
421 }
422
423 static ssize_t ppp_read(struct file *file, char __user *buf,
424 size_t count, loff_t *ppos)
425 {
426 struct ppp_file *pf = file->private_data;
427 DECLARE_WAITQUEUE(wait, current);
428 ssize_t ret;
429 struct sk_buff *skb = NULL;
430 struct iovec iov;
431 struct iov_iter to;
432
433 ret = count;
434
435 if (!pf)
436 return -ENXIO;
437 add_wait_queue(&pf->rwait, &wait);
438 for (;;) {
439 set_current_state(TASK_INTERRUPTIBLE);
440 skb = skb_dequeue(&pf->rq);
441 if (skb)
442 break;
443 ret = 0;
444 if (pf->dead)
445 break;
446 if (pf->kind == INTERFACE) {
447 /*
448 * Return 0 (EOF) on an interface that has no
449 * channels connected, unless it is looping
450 * network traffic (demand mode).
451 */
452 struct ppp *ppp = PF_TO_PPP(pf);
453
454 ppp_recv_lock(ppp);
455 if (ppp->n_channels == 0 &&
456 (ppp->flags & SC_LOOP_TRAFFIC) == 0) {
457 ppp_recv_unlock(ppp);
458 break;
459 }
460 ppp_recv_unlock(ppp);
461 }
462 ret = -EAGAIN;
463 if (file->f_flags & O_NONBLOCK)
464 break;
465 ret = -ERESTARTSYS;
466 if (signal_pending(current))
467 break;
468 schedule();
469 }
470 set_current_state(TASK_RUNNING);
471 remove_wait_queue(&pf->rwait, &wait);
472
473 if (!skb)
474 goto out;
475
476 ret = -EOVERFLOW;
477 if (skb->len > count)
478 goto outf;
479 ret = -EFAULT;
480 iov.iov_base = buf;
481 iov.iov_len = count;
482 iov_iter_init(&to, READ, &iov, 1, count);
483 if (skb_copy_datagram_iter(skb, 0, &to, skb->len))
484 goto outf;
485 ret = skb->len;
486
487 outf:
488 kfree_skb(skb);
489 out:
490 return ret;
491 }
492
493 static ssize_t ppp_write(struct file *file, const char __user *buf,
494 size_t count, loff_t *ppos)
495 {
496 struct ppp_file *pf = file->private_data;
497 struct sk_buff *skb;
498 ssize_t ret;
499
500 if (!pf)
501 return -ENXIO;
502 ret = -ENOMEM;
503 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
504 if (!skb)
505 goto out;
506 skb_reserve(skb, pf->hdrlen);
507 ret = -EFAULT;
508 if (copy_from_user(skb_put(skb, count), buf, count)) {
509 kfree_skb(skb);
510 goto out;
511 }
512
513 skb_queue_tail(&pf->xq, skb);
514
515 switch (pf->kind) {
516 case INTERFACE:
517 ppp_xmit_process(PF_TO_PPP(pf));
518 break;
519 case CHANNEL:
520 ppp_channel_push(PF_TO_CHANNEL(pf));
521 break;
522 }
523
524 ret = count;
525
526 out:
527 return ret;
528 }
529
530 /* No kernel lock - fine */
531 static unsigned int ppp_poll(struct file *file, poll_table *wait)
532 {
533 struct ppp_file *pf = file->private_data;
534 unsigned int mask;
535
536 if (!pf)
537 return 0;
538 poll_wait(file, &pf->rwait, wait);
539 mask = POLLOUT | POLLWRNORM;
540 if (skb_peek(&pf->rq))
541 mask |= POLLIN | POLLRDNORM;
542 if (pf->dead)
543 mask |= POLLHUP;
544 else if (pf->kind == INTERFACE) {
545 /* see comment in ppp_read */
546 struct ppp *ppp = PF_TO_PPP(pf);
547
548 ppp_recv_lock(ppp);
549 if (ppp->n_channels == 0 &&
550 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
551 mask |= POLLIN | POLLRDNORM;
552 ppp_recv_unlock(ppp);
553 }
554
555 return mask;
556 }
557
558 #ifdef CONFIG_PPP_FILTER
559 static int get_filter(void __user *arg, struct sock_filter **p)
560 {
561 struct sock_fprog uprog;
562 struct sock_filter *code = NULL;
563 int len;
564
565 if (copy_from_user(&uprog, arg, sizeof(uprog)))
566 return -EFAULT;
567
568 if (!uprog.len) {
569 *p = NULL;
570 return 0;
571 }
572
573 len = uprog.len * sizeof(struct sock_filter);
574 code = memdup_user(uprog.filter, len);
575 if (IS_ERR(code))
576 return PTR_ERR(code);
577
578 *p = code;
579 return uprog.len;
580 }
581 #endif /* CONFIG_PPP_FILTER */
582
583 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
584 {
585 struct ppp_file *pf;
586 struct ppp *ppp;
587 int err = -EFAULT, val, val2, i;
588 struct ppp_idle idle;
589 struct npioctl npi;
590 int unit, cflags;
591 struct slcompress *vj;
592 void __user *argp = (void __user *)arg;
593 int __user *p = argp;
594
595 mutex_lock(&ppp_mutex);
596
597 pf = file->private_data;
598 if (!pf) {
599 err = ppp_unattached_ioctl(current->nsproxy->net_ns,
600 pf, file, cmd, arg);
601 goto out;
602 }
603
604 if (cmd == PPPIOCDETACH) {
605 /*
606 * We have to be careful here... if the file descriptor
607 * has been dup'd, we could have another process in the
608 * middle of a poll using the same file *, so we had
609 * better not free the interface data structures -
610 * instead we fail the ioctl. Even in this case, we
611 * shut down the interface if we are the owner of it.
612 * Actually, we should get rid of PPPIOCDETACH, userland
613 * (i.e. pppd) could achieve the same effect by closing
614 * this fd and reopening /dev/ppp.
615 */
616 err = -EINVAL;
617 if (pf->kind == INTERFACE) {
618 ppp = PF_TO_PPP(pf);
619 rtnl_lock();
620 if (file == ppp->owner)
621 unregister_netdevice(ppp->dev);
622 rtnl_unlock();
623 }
624 if (atomic_long_read(&file->f_count) < 2) {
625 ppp_release(NULL, file);
626 err = 0;
627 } else
628 pr_warn("PPPIOCDETACH file->f_count=%ld\n",
629 atomic_long_read(&file->f_count));
630 goto out;
631 }
632
633 if (pf->kind == CHANNEL) {
634 struct channel *pch;
635 struct ppp_channel *chan;
636
637 pch = PF_TO_CHANNEL(pf);
638
639 switch (cmd) {
640 case PPPIOCCONNECT:
641 if (get_user(unit, p))
642 break;
643 err = ppp_connect_channel(pch, unit);
644 break;
645
646 case PPPIOCDISCONN:
647 err = ppp_disconnect_channel(pch);
648 break;
649
650 default:
651 down_read(&pch->chan_sem);
652 chan = pch->chan;
653 err = -ENOTTY;
654 if (chan && chan->ops->ioctl)
655 err = chan->ops->ioctl(chan, cmd, arg);
656 up_read(&pch->chan_sem);
657 }
658 goto out;
659 }
660
661 if (pf->kind != INTERFACE) {
662 /* can't happen */
663 pr_err("PPP: not interface or channel??\n");
664 err = -EINVAL;
665 goto out;
666 }
667
668 ppp = PF_TO_PPP(pf);
669 switch (cmd) {
670 case PPPIOCSMRU:
671 if (get_user(val, p))
672 break;
673 ppp->mru = val;
674 err = 0;
675 break;
676
677 case PPPIOCSFLAGS:
678 if (get_user(val, p))
679 break;
680 ppp_lock(ppp);
681 cflags = ppp->flags & ~val;
682 #ifdef CONFIG_PPP_MULTILINK
683 if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK))
684 ppp->nextseq = 0;
685 #endif
686 ppp->flags = val & SC_FLAG_BITS;
687 ppp_unlock(ppp);
688 if (cflags & SC_CCP_OPEN)
689 ppp_ccp_closed(ppp);
690 err = 0;
691 break;
692
693 case PPPIOCGFLAGS:
694 val = ppp->flags | ppp->xstate | ppp->rstate;
695 if (put_user(val, p))
696 break;
697 err = 0;
698 break;
699
700 case PPPIOCSCOMPRESS:
701 err = ppp_set_compress(ppp, arg);
702 break;
703
704 case PPPIOCGUNIT:
705 if (put_user(ppp->file.index, p))
706 break;
707 err = 0;
708 break;
709
710 case PPPIOCSDEBUG:
711 if (get_user(val, p))
712 break;
713 ppp->debug = val;
714 err = 0;
715 break;
716
717 case PPPIOCGDEBUG:
718 if (put_user(ppp->debug, p))
719 break;
720 err = 0;
721 break;
722
723 case PPPIOCGIDLE:
724 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
725 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
726 if (copy_to_user(argp, &idle, sizeof(idle)))
727 break;
728 err = 0;
729 break;
730
731 case PPPIOCSMAXCID:
732 if (get_user(val, p))
733 break;
734 val2 = 15;
735 if ((val >> 16) != 0) {
736 val2 = val >> 16;
737 val &= 0xffff;
738 }
739 vj = slhc_init(val2+1, val+1);
740 if (IS_ERR(vj)) {
741 err = PTR_ERR(vj);
742 break;
743 }
744 ppp_lock(ppp);
745 if (ppp->vj)
746 slhc_free(ppp->vj);
747 ppp->vj = vj;
748 ppp_unlock(ppp);
749 err = 0;
750 break;
751
752 case PPPIOCGNPMODE:
753 case PPPIOCSNPMODE:
754 if (copy_from_user(&npi, argp, sizeof(npi)))
755 break;
756 err = proto_to_npindex(npi.protocol);
757 if (err < 0)
758 break;
759 i = err;
760 if (cmd == PPPIOCGNPMODE) {
761 err = -EFAULT;
762 npi.mode = ppp->npmode[i];
763 if (copy_to_user(argp, &npi, sizeof(npi)))
764 break;
765 } else {
766 ppp->npmode[i] = npi.mode;
767 /* we may be able to transmit more packets now (??) */
768 netif_wake_queue(ppp->dev);
769 }
770 err = 0;
771 break;
772
773 #ifdef CONFIG_PPP_FILTER
774 case PPPIOCSPASS:
775 {
776 struct sock_filter *code;
777
778 err = get_filter(argp, &code);
779 if (err >= 0) {
780 struct bpf_prog *pass_filter = NULL;
781 struct sock_fprog_kern fprog = {
782 .len = err,
783 .filter = code,
784 };
785
786 err = 0;
787 if (fprog.filter)
788 err = bpf_prog_create(&pass_filter, &fprog);
789 if (!err) {
790 ppp_lock(ppp);
791 if (ppp->pass_filter)
792 bpf_prog_destroy(ppp->pass_filter);
793 ppp->pass_filter = pass_filter;
794 ppp_unlock(ppp);
795 }
796 kfree(code);
797 }
798 break;
799 }
800 case PPPIOCSACTIVE:
801 {
802 struct sock_filter *code;
803
804 err = get_filter(argp, &code);
805 if (err >= 0) {
806 struct bpf_prog *active_filter = NULL;
807 struct sock_fprog_kern fprog = {
808 .len = err,
809 .filter = code,
810 };
811
812 err = 0;
813 if (fprog.filter)
814 err = bpf_prog_create(&active_filter, &fprog);
815 if (!err) {
816 ppp_lock(ppp);
817 if (ppp->active_filter)
818 bpf_prog_destroy(ppp->active_filter);
819 ppp->active_filter = active_filter;
820 ppp_unlock(ppp);
821 }
822 kfree(code);
823 }
824 break;
825 }
826 #endif /* CONFIG_PPP_FILTER */
827
828 #ifdef CONFIG_PPP_MULTILINK
829 case PPPIOCSMRRU:
830 if (get_user(val, p))
831 break;
832 ppp_recv_lock(ppp);
833 ppp->mrru = val;
834 ppp_recv_unlock(ppp);
835 err = 0;
836 break;
837 #endif /* CONFIG_PPP_MULTILINK */
838
839 default:
840 err = -ENOTTY;
841 }
842
843 out:
844 mutex_unlock(&ppp_mutex);
845
846 return err;
847 }
848
849 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
850 struct file *file, unsigned int cmd, unsigned long arg)
851 {
852 int unit, err = -EFAULT;
853 struct ppp *ppp;
854 struct channel *chan;
855 struct ppp_net *pn;
856 int __user *p = (int __user *)arg;
857
858 switch (cmd) {
859 case PPPIOCNEWUNIT:
860 /* Create a new ppp unit */
861 if (get_user(unit, p))
862 break;
863 err = ppp_create_interface(net, file, &unit);
864 if (err < 0)
865 break;
866
867 err = -EFAULT;
868 if (put_user(unit, p))
869 break;
870 err = 0;
871 break;
872
873 case PPPIOCATTACH:
874 /* Attach to an existing ppp unit */
875 if (get_user(unit, p))
876 break;
877 err = -ENXIO;
878 pn = ppp_pernet(net);
879 mutex_lock(&pn->all_ppp_mutex);
880 ppp = ppp_find_unit(pn, unit);
881 if (ppp) {
882 atomic_inc(&ppp->file.refcnt);
883 file->private_data = &ppp->file;
884 err = 0;
885 }
886 mutex_unlock(&pn->all_ppp_mutex);
887 break;
888
889 case PPPIOCATTCHAN:
890 if (get_user(unit, p))
891 break;
892 err = -ENXIO;
893 pn = ppp_pernet(net);
894 spin_lock_bh(&pn->all_channels_lock);
895 chan = ppp_find_channel(pn, unit);
896 if (chan) {
897 atomic_inc(&chan->file.refcnt);
898 file->private_data = &chan->file;
899 err = 0;
900 }
901 spin_unlock_bh(&pn->all_channels_lock);
902 break;
903
904 default:
905 err = -ENOTTY;
906 }
907
908 return err;
909 }
910
911 static const struct file_operations ppp_device_fops = {
912 .owner = THIS_MODULE,
913 .read = ppp_read,
914 .write = ppp_write,
915 .poll = ppp_poll,
916 .unlocked_ioctl = ppp_ioctl,
917 .open = ppp_open,
918 .release = ppp_release,
919 .llseek = noop_llseek,
920 };
921
922 static __net_init int ppp_init_net(struct net *net)
923 {
924 struct ppp_net *pn = net_generic(net, ppp_net_id);
925
926 idr_init(&pn->units_idr);
927 mutex_init(&pn->all_ppp_mutex);
928
929 INIT_LIST_HEAD(&pn->all_channels);
930 INIT_LIST_HEAD(&pn->new_channels);
931
932 spin_lock_init(&pn->all_channels_lock);
933
934 return 0;
935 }
936
937 static __net_exit void ppp_exit_net(struct net *net)
938 {
939 struct ppp_net *pn = net_generic(net, ppp_net_id);
940 struct net_device *dev;
941 struct net_device *aux;
942 struct ppp *ppp;
943 LIST_HEAD(list);
944 int id;
945
946 rtnl_lock();
947 for_each_netdev_safe(net, dev, aux) {
948 if (dev->netdev_ops == &ppp_netdev_ops)
949 unregister_netdevice_queue(dev, &list);
950 }
951
952 idr_for_each_entry(&pn->units_idr, ppp, id)
953 /* Skip devices already unregistered by previous loop */
954 if (!net_eq(dev_net(ppp->dev), net))
955 unregister_netdevice_queue(ppp->dev, &list);
956
957 unregister_netdevice_many(&list);
958 rtnl_unlock();
959
960 idr_destroy(&pn->units_idr);
961 }
962
963 static struct pernet_operations ppp_net_ops = {
964 .init = ppp_init_net,
965 .exit = ppp_exit_net,
966 .id = &ppp_net_id,
967 .size = sizeof(struct ppp_net),
968 };
969
970 static int ppp_unit_register(struct ppp *ppp, int unit, bool ifname_is_set)
971 {
972 struct ppp_net *pn = ppp_pernet(ppp->ppp_net);
973 int ret;
974
975 mutex_lock(&pn->all_ppp_mutex);
976
977 if (unit < 0) {
978 ret = unit_get(&pn->units_idr, ppp);
979 if (ret < 0)
980 goto err;
981 } else {
982 /* Caller asked for a specific unit number. Fail with -EEXIST
983 * if unavailable. For backward compatibility, return -EEXIST
984 * too if idr allocation fails; this makes pppd retry without
985 * requesting a specific unit number.
986 */
987 if (unit_find(&pn->units_idr, unit)) {
988 ret = -EEXIST;
989 goto err;
990 }
991 ret = unit_set(&pn->units_idr, ppp, unit);
992 if (ret < 0) {
993 /* Rewrite error for backward compatibility */
994 ret = -EEXIST;
995 goto err;
996 }
997 }
998 ppp->file.index = ret;
999
1000 if (!ifname_is_set)
1001 snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ppp->file.index);
1002
1003 ret = register_netdevice(ppp->dev);
1004 if (ret < 0)
1005 goto err_unit;
1006
1007 atomic_inc(&ppp_unit_count);
1008
1009 mutex_unlock(&pn->all_ppp_mutex);
1010
1011 return 0;
1012
1013 err_unit:
1014 unit_put(&pn->units_idr, ppp->file.index);
1015 err:
1016 mutex_unlock(&pn->all_ppp_mutex);
1017
1018 return ret;
1019 }
1020
1021 static int ppp_dev_configure(struct net *src_net, struct net_device *dev,
1022 const struct ppp_config *conf)
1023 {
1024 struct ppp *ppp = netdev_priv(dev);
1025 int indx;
1026 int err;
1027
1028 ppp->dev = dev;
1029 ppp->ppp_net = src_net;
1030 ppp->mru = PPP_MRU;
1031 ppp->owner = conf->file;
1032
1033 init_ppp_file(&ppp->file, INTERFACE);
1034 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
1035
1036 for (indx = 0; indx < NUM_NP; ++indx)
1037 ppp->npmode[indx] = NPMODE_PASS;
1038 INIT_LIST_HEAD(&ppp->channels);
1039 spin_lock_init(&ppp->rlock);
1040 spin_lock_init(&ppp->wlock);
1041 #ifdef CONFIG_PPP_MULTILINK
1042 ppp->minseq = -1;
1043 skb_queue_head_init(&ppp->mrq);
1044 #endif /* CONFIG_PPP_MULTILINK */
1045 #ifdef CONFIG_PPP_FILTER
1046 ppp->pass_filter = NULL;
1047 ppp->active_filter = NULL;
1048 #endif /* CONFIG_PPP_FILTER */
1049
1050 err = ppp_unit_register(ppp, conf->unit, conf->ifname_is_set);
1051 if (err < 0)
1052 return err;
1053
1054 conf->file->private_data = &ppp->file;
1055
1056 return 0;
1057 }
1058
1059 static const struct nla_policy ppp_nl_policy[IFLA_PPP_MAX + 1] = {
1060 [IFLA_PPP_DEV_FD] = { .type = NLA_S32 },
1061 };
1062
1063 static int ppp_nl_validate(struct nlattr *tb[], struct nlattr *data[])
1064 {
1065 if (!data)
1066 return -EINVAL;
1067
1068 if (!data[IFLA_PPP_DEV_FD])
1069 return -EINVAL;
1070 if (nla_get_s32(data[IFLA_PPP_DEV_FD]) < 0)
1071 return -EBADF;
1072
1073 return 0;
1074 }
1075
1076 static int ppp_nl_newlink(struct net *src_net, struct net_device *dev,
1077 struct nlattr *tb[], struct nlattr *data[])
1078 {
1079 struct ppp_config conf = {
1080 .unit = -1,
1081 .ifname_is_set = true,
1082 };
1083 struct file *file;
1084 int err;
1085
1086 file = fget(nla_get_s32(data[IFLA_PPP_DEV_FD]));
1087 if (!file)
1088 return -EBADF;
1089
1090 /* rtnl_lock is already held here, but ppp_create_interface() locks
1091 * ppp_mutex before holding rtnl_lock. Using mutex_trylock() avoids
1092 * possible deadlock due to lock order inversion, at the cost of
1093 * pushing the problem back to userspace.
1094 */
1095 if (!mutex_trylock(&ppp_mutex)) {
1096 err = -EBUSY;
1097 goto out;
1098 }
1099
1100 if (file->f_op != &ppp_device_fops || file->private_data) {
1101 err = -EBADF;
1102 goto out_unlock;
1103 }
1104
1105 conf.file = file;
1106
1107 /* Don't use device name generated by the rtnetlink layer when ifname
1108 * isn't specified. Let ppp_dev_configure() set the device name using
1109 * the PPP unit identifer as suffix (i.e. ppp<unit_id>). This allows
1110 * userspace to infer the device name using to the PPPIOCGUNIT ioctl.
1111 */
1112 if (!tb[IFLA_IFNAME])
1113 conf.ifname_is_set = false;
1114
1115 err = ppp_dev_configure(src_net, dev, &conf);
1116
1117 out_unlock:
1118 mutex_unlock(&ppp_mutex);
1119 out:
1120 fput(file);
1121
1122 return err;
1123 }
1124
1125 static void ppp_nl_dellink(struct net_device *dev, struct list_head *head)
1126 {
1127 unregister_netdevice_queue(dev, head);
1128 }
1129
1130 static size_t ppp_nl_get_size(const struct net_device *dev)
1131 {
1132 return 0;
1133 }
1134
1135 static int ppp_nl_fill_info(struct sk_buff *skb, const struct net_device *dev)
1136 {
1137 return 0;
1138 }
1139
1140 static struct net *ppp_nl_get_link_net(const struct net_device *dev)
1141 {
1142 struct ppp *ppp = netdev_priv(dev);
1143
1144 return ppp->ppp_net;
1145 }
1146
1147 static struct rtnl_link_ops ppp_link_ops __read_mostly = {
1148 .kind = "ppp",
1149 .maxtype = IFLA_PPP_MAX,
1150 .policy = ppp_nl_policy,
1151 .priv_size = sizeof(struct ppp),
1152 .setup = ppp_setup,
1153 .validate = ppp_nl_validate,
1154 .newlink = ppp_nl_newlink,
1155 .dellink = ppp_nl_dellink,
1156 .get_size = ppp_nl_get_size,
1157 .fill_info = ppp_nl_fill_info,
1158 .get_link_net = ppp_nl_get_link_net,
1159 };
1160
1161 #define PPP_MAJOR 108
1162
1163 /* Called at boot time if ppp is compiled into the kernel,
1164 or at module load time (from init_module) if compiled as a module. */
1165 static int __init ppp_init(void)
1166 {
1167 int err;
1168
1169 pr_info("PPP generic driver version " PPP_VERSION "\n");
1170
1171 err = register_pernet_device(&ppp_net_ops);
1172 if (err) {
1173 pr_err("failed to register PPP pernet device (%d)\n", err);
1174 goto out;
1175 }
1176
1177 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
1178 if (err) {
1179 pr_err("failed to register PPP device (%d)\n", err);
1180 goto out_net;
1181 }
1182
1183 ppp_class = class_create(THIS_MODULE, "ppp");
1184 if (IS_ERR(ppp_class)) {
1185 err = PTR_ERR(ppp_class);
1186 goto out_chrdev;
1187 }
1188
1189 err = rtnl_link_register(&ppp_link_ops);
1190 if (err) {
1191 pr_err("failed to register rtnetlink PPP handler\n");
1192 goto out_class;
1193 }
1194
1195 /* not a big deal if we fail here :-) */
1196 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
1197
1198 return 0;
1199
1200 out_class:
1201 class_destroy(ppp_class);
1202 out_chrdev:
1203 unregister_chrdev(PPP_MAJOR, "ppp");
1204 out_net:
1205 unregister_pernet_device(&ppp_net_ops);
1206 out:
1207 return err;
1208 }
1209
1210 /*
1211 * Network interface unit routines.
1212 */
1213 static netdev_tx_t
1214 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
1215 {
1216 struct ppp *ppp = netdev_priv(dev);
1217 int npi, proto;
1218 unsigned char *pp;
1219
1220 npi = ethertype_to_npindex(ntohs(skb->protocol));
1221 if (npi < 0)
1222 goto outf;
1223
1224 /* Drop, accept or reject the packet */
1225 switch (ppp->npmode[npi]) {
1226 case NPMODE_PASS:
1227 break;
1228 case NPMODE_QUEUE:
1229 /* it would be nice to have a way to tell the network
1230 system to queue this one up for later. */
1231 goto outf;
1232 case NPMODE_DROP:
1233 case NPMODE_ERROR:
1234 goto outf;
1235 }
1236
1237 /* Put the 2-byte PPP protocol number on the front,
1238 making sure there is room for the address and control fields. */
1239 if (skb_cow_head(skb, PPP_HDRLEN))
1240 goto outf;
1241
1242 pp = skb_push(skb, 2);
1243 proto = npindex_to_proto[npi];
1244 put_unaligned_be16(proto, pp);
1245
1246 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, dev_net(dev)));
1247 skb_queue_tail(&ppp->file.xq, skb);
1248 ppp_xmit_process(ppp);
1249 return NETDEV_TX_OK;
1250
1251 outf:
1252 kfree_skb(skb);
1253 ++dev->stats.tx_dropped;
1254 return NETDEV_TX_OK;
1255 }
1256
1257 static int
1258 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1259 {
1260 struct ppp *ppp = netdev_priv(dev);
1261 int err = -EFAULT;
1262 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
1263 struct ppp_stats stats;
1264 struct ppp_comp_stats cstats;
1265 char *vers;
1266
1267 switch (cmd) {
1268 case SIOCGPPPSTATS:
1269 ppp_get_stats(ppp, &stats);
1270 if (copy_to_user(addr, &stats, sizeof(stats)))
1271 break;
1272 err = 0;
1273 break;
1274
1275 case SIOCGPPPCSTATS:
1276 memset(&cstats, 0, sizeof(cstats));
1277 if (ppp->xc_state)
1278 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
1279 if (ppp->rc_state)
1280 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
1281 if (copy_to_user(addr, &cstats, sizeof(cstats)))
1282 break;
1283 err = 0;
1284 break;
1285
1286 case SIOCGPPPVER:
1287 vers = PPP_VERSION;
1288 if (copy_to_user(addr, vers, strlen(vers) + 1))
1289 break;
1290 err = 0;
1291 break;
1292
1293 default:
1294 err = -EINVAL;
1295 }
1296
1297 return err;
1298 }
1299
1300 static struct rtnl_link_stats64*
1301 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64)
1302 {
1303 struct ppp *ppp = netdev_priv(dev);
1304
1305 ppp_recv_lock(ppp);
1306 stats64->rx_packets = ppp->stats64.rx_packets;
1307 stats64->rx_bytes = ppp->stats64.rx_bytes;
1308 ppp_recv_unlock(ppp);
1309
1310 ppp_xmit_lock(ppp);
1311 stats64->tx_packets = ppp->stats64.tx_packets;
1312 stats64->tx_bytes = ppp->stats64.tx_bytes;
1313 ppp_xmit_unlock(ppp);
1314
1315 stats64->rx_errors = dev->stats.rx_errors;
1316 stats64->tx_errors = dev->stats.tx_errors;
1317 stats64->rx_dropped = dev->stats.rx_dropped;
1318 stats64->tx_dropped = dev->stats.tx_dropped;
1319 stats64->rx_length_errors = dev->stats.rx_length_errors;
1320
1321 return stats64;
1322 }
1323
1324 static int ppp_dev_init(struct net_device *dev)
1325 {
1326 netdev_lockdep_set_classes(dev);
1327 return 0;
1328 }
1329
1330 static void ppp_dev_uninit(struct net_device *dev)
1331 {
1332 struct ppp *ppp = netdev_priv(dev);
1333 struct ppp_net *pn = ppp_pernet(ppp->ppp_net);
1334
1335 ppp_lock(ppp);
1336 ppp->closing = 1;
1337 ppp_unlock(ppp);
1338
1339 mutex_lock(&pn->all_ppp_mutex);
1340 unit_put(&pn->units_idr, ppp->file.index);
1341 mutex_unlock(&pn->all_ppp_mutex);
1342
1343 ppp->owner = NULL;
1344
1345 ppp->file.dead = 1;
1346 wake_up_interruptible(&ppp->file.rwait);
1347 }
1348
1349 static const struct net_device_ops ppp_netdev_ops = {
1350 .ndo_init = ppp_dev_init,
1351 .ndo_uninit = ppp_dev_uninit,
1352 .ndo_start_xmit = ppp_start_xmit,
1353 .ndo_do_ioctl = ppp_net_ioctl,
1354 .ndo_get_stats64 = ppp_get_stats64,
1355 };
1356
1357 static struct device_type ppp_type = {
1358 .name = "ppp",
1359 };
1360
1361 static void ppp_setup(struct net_device *dev)
1362 {
1363 dev->netdev_ops = &ppp_netdev_ops;
1364 SET_NETDEV_DEVTYPE(dev, &ppp_type);
1365
1366 dev->features |= NETIF_F_LLTX;
1367
1368 dev->hard_header_len = PPP_HDRLEN;
1369 dev->mtu = PPP_MRU;
1370 dev->addr_len = 0;
1371 dev->tx_queue_len = 3;
1372 dev->type = ARPHRD_PPP;
1373 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1374 netif_keep_dst(dev);
1375 }
1376
1377 /*
1378 * Transmit-side routines.
1379 */
1380
1381 /* Called to do any work queued up on the transmit side that can now be done */
1382 static void __ppp_xmit_process(struct ppp *ppp)
1383 {
1384 struct sk_buff *skb;
1385
1386 ppp_xmit_lock(ppp);
1387 if (!ppp->closing) {
1388 ppp_push(ppp);
1389 while (!ppp->xmit_pending &&
1390 (skb = skb_dequeue(&ppp->file.xq)))
1391 ppp_send_frame(ppp, skb);
1392 /* If there's no work left to do, tell the core net
1393 code that we can accept some more. */
1394 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1395 netif_wake_queue(ppp->dev);
1396 else
1397 netif_stop_queue(ppp->dev);
1398 }
1399 ppp_xmit_unlock(ppp);
1400 }
1401
1402 static DEFINE_PER_CPU(int, ppp_xmit_recursion);
1403
1404 static void ppp_xmit_process(struct ppp *ppp)
1405 {
1406 local_bh_disable();
1407
1408 if (unlikely(__this_cpu_read(ppp_xmit_recursion)))
1409 goto err;
1410
1411 __this_cpu_inc(ppp_xmit_recursion);
1412 __ppp_xmit_process(ppp);
1413 __this_cpu_dec(ppp_xmit_recursion);
1414
1415 local_bh_enable();
1416
1417 return;
1418
1419 err:
1420 local_bh_enable();
1421
1422 if (net_ratelimit())
1423 netdev_err(ppp->dev, "recursion detected\n");
1424 }
1425
1426 static inline struct sk_buff *
1427 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1428 {
1429 struct sk_buff *new_skb;
1430 int len;
1431 int new_skb_size = ppp->dev->mtu +
1432 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1433 int compressor_skb_size = ppp->dev->mtu +
1434 ppp->xcomp->comp_extra + PPP_HDRLEN;
1435 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1436 if (!new_skb) {
1437 if (net_ratelimit())
1438 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n");
1439 return NULL;
1440 }
1441 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1442 skb_reserve(new_skb,
1443 ppp->dev->hard_header_len - PPP_HDRLEN);
1444
1445 /* compressor still expects A/C bytes in hdr */
1446 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1447 new_skb->data, skb->len + 2,
1448 compressor_skb_size);
1449 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1450 consume_skb(skb);
1451 skb = new_skb;
1452 skb_put(skb, len);
1453 skb_pull(skb, 2); /* pull off A/C bytes */
1454 } else if (len == 0) {
1455 /* didn't compress, or CCP not up yet */
1456 consume_skb(new_skb);
1457 new_skb = skb;
1458 } else {
1459 /*
1460 * (len < 0)
1461 * MPPE requires that we do not send unencrypted
1462 * frames. The compressor will return -1 if we
1463 * should drop the frame. We cannot simply test
1464 * the compress_proto because MPPE and MPPC share
1465 * the same number.
1466 */
1467 if (net_ratelimit())
1468 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n");
1469 kfree_skb(skb);
1470 consume_skb(new_skb);
1471 new_skb = NULL;
1472 }
1473 return new_skb;
1474 }
1475
1476 /*
1477 * Compress and send a frame.
1478 * The caller should have locked the xmit path,
1479 * and xmit_pending should be 0.
1480 */
1481 static void
1482 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1483 {
1484 int proto = PPP_PROTO(skb);
1485 struct sk_buff *new_skb;
1486 int len;
1487 unsigned char *cp;
1488
1489 if (proto < 0x8000) {
1490 #ifdef CONFIG_PPP_FILTER
1491 /* check if we should pass this packet */
1492 /* the filter instructions are constructed assuming
1493 a four-byte PPP header on each packet */
1494 *skb_push(skb, 2) = 1;
1495 if (ppp->pass_filter &&
1496 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
1497 if (ppp->debug & 1)
1498 netdev_printk(KERN_DEBUG, ppp->dev,
1499 "PPP: outbound frame "
1500 "not passed\n");
1501 kfree_skb(skb);
1502 return;
1503 }
1504 /* if this packet passes the active filter, record the time */
1505 if (!(ppp->active_filter &&
1506 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
1507 ppp->last_xmit = jiffies;
1508 skb_pull(skb, 2);
1509 #else
1510 /* for data packets, record the time */
1511 ppp->last_xmit = jiffies;
1512 #endif /* CONFIG_PPP_FILTER */
1513 }
1514
1515 ++ppp->stats64.tx_packets;
1516 ppp->stats64.tx_bytes += skb->len - 2;
1517
1518 switch (proto) {
1519 case PPP_IP:
1520 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1521 break;
1522 /* try to do VJ TCP header compression */
1523 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1524 GFP_ATOMIC);
1525 if (!new_skb) {
1526 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n");
1527 goto drop;
1528 }
1529 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1530 cp = skb->data + 2;
1531 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1532 new_skb->data + 2, &cp,
1533 !(ppp->flags & SC_NO_TCP_CCID));
1534 if (cp == skb->data + 2) {
1535 /* didn't compress */
1536 consume_skb(new_skb);
1537 } else {
1538 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1539 proto = PPP_VJC_COMP;
1540 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1541 } else {
1542 proto = PPP_VJC_UNCOMP;
1543 cp[0] = skb->data[2];
1544 }
1545 consume_skb(skb);
1546 skb = new_skb;
1547 cp = skb_put(skb, len + 2);
1548 cp[0] = 0;
1549 cp[1] = proto;
1550 }
1551 break;
1552
1553 case PPP_CCP:
1554 /* peek at outbound CCP frames */
1555 ppp_ccp_peek(ppp, skb, 0);
1556 break;
1557 }
1558
1559 /* try to do packet compression */
1560 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state &&
1561 proto != PPP_LCP && proto != PPP_CCP) {
1562 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1563 if (net_ratelimit())
1564 netdev_err(ppp->dev,
1565 "ppp: compression required but "
1566 "down - pkt dropped.\n");
1567 goto drop;
1568 }
1569 skb = pad_compress_skb(ppp, skb);
1570 if (!skb)
1571 goto drop;
1572 }
1573
1574 /*
1575 * If we are waiting for traffic (demand dialling),
1576 * queue it up for pppd to receive.
1577 */
1578 if (ppp->flags & SC_LOOP_TRAFFIC) {
1579 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1580 goto drop;
1581 skb_queue_tail(&ppp->file.rq, skb);
1582 wake_up_interruptible(&ppp->file.rwait);
1583 return;
1584 }
1585
1586 ppp->xmit_pending = skb;
1587 ppp_push(ppp);
1588 return;
1589
1590 drop:
1591 kfree_skb(skb);
1592 ++ppp->dev->stats.tx_errors;
1593 }
1594
1595 /*
1596 * Try to send the frame in xmit_pending.
1597 * The caller should have the xmit path locked.
1598 */
1599 static void
1600 ppp_push(struct ppp *ppp)
1601 {
1602 struct list_head *list;
1603 struct channel *pch;
1604 struct sk_buff *skb = ppp->xmit_pending;
1605
1606 if (!skb)
1607 return;
1608
1609 list = &ppp->channels;
1610 if (list_empty(list)) {
1611 /* nowhere to send the packet, just drop it */
1612 ppp->xmit_pending = NULL;
1613 kfree_skb(skb);
1614 return;
1615 }
1616
1617 if ((ppp->flags & SC_MULTILINK) == 0) {
1618 /* not doing multilink: send it down the first channel */
1619 list = list->next;
1620 pch = list_entry(list, struct channel, clist);
1621
1622 spin_lock_bh(&pch->downl);
1623 if (pch->chan) {
1624 if (pch->chan->ops->start_xmit(pch->chan, skb))
1625 ppp->xmit_pending = NULL;
1626 } else {
1627 /* channel got unregistered */
1628 kfree_skb(skb);
1629 ppp->xmit_pending = NULL;
1630 }
1631 spin_unlock_bh(&pch->downl);
1632 return;
1633 }
1634
1635 #ifdef CONFIG_PPP_MULTILINK
1636 /* Multilink: fragment the packet over as many links
1637 as can take the packet at the moment. */
1638 if (!ppp_mp_explode(ppp, skb))
1639 return;
1640 #endif /* CONFIG_PPP_MULTILINK */
1641
1642 ppp->xmit_pending = NULL;
1643 kfree_skb(skb);
1644 }
1645
1646 #ifdef CONFIG_PPP_MULTILINK
1647 static bool mp_protocol_compress __read_mostly = true;
1648 module_param(mp_protocol_compress, bool, S_IRUGO | S_IWUSR);
1649 MODULE_PARM_DESC(mp_protocol_compress,
1650 "compress protocol id in multilink fragments");
1651
1652 /*
1653 * Divide a packet to be transmitted into fragments and
1654 * send them out the individual links.
1655 */
1656 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1657 {
1658 int len, totlen;
1659 int i, bits, hdrlen, mtu;
1660 int flen;
1661 int navail, nfree, nzero;
1662 int nbigger;
1663 int totspeed;
1664 int totfree;
1665 unsigned char *p, *q;
1666 struct list_head *list;
1667 struct channel *pch;
1668 struct sk_buff *frag;
1669 struct ppp_channel *chan;
1670
1671 totspeed = 0; /*total bitrate of the bundle*/
1672 nfree = 0; /* # channels which have no packet already queued */
1673 navail = 0; /* total # of usable channels (not deregistered) */
1674 nzero = 0; /* number of channels with zero speed associated*/
1675 totfree = 0; /*total # of channels available and
1676 *having no queued packets before
1677 *starting the fragmentation*/
1678
1679 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1680 i = 0;
1681 list_for_each_entry(pch, &ppp->channels, clist) {
1682 if (pch->chan) {
1683 pch->avail = 1;
1684 navail++;
1685 pch->speed = pch->chan->speed;
1686 } else {
1687 pch->avail = 0;
1688 }
1689 if (pch->avail) {
1690 if (skb_queue_empty(&pch->file.xq) ||
1691 !pch->had_frag) {
1692 if (pch->speed == 0)
1693 nzero++;
1694 else
1695 totspeed += pch->speed;
1696
1697 pch->avail = 2;
1698 ++nfree;
1699 ++totfree;
1700 }
1701 if (!pch->had_frag && i < ppp->nxchan)
1702 ppp->nxchan = i;
1703 }
1704 ++i;
1705 }
1706 /*
1707 * Don't start sending this packet unless at least half of
1708 * the channels are free. This gives much better TCP
1709 * performance if we have a lot of channels.
1710 */
1711 if (nfree == 0 || nfree < navail / 2)
1712 return 0; /* can't take now, leave it in xmit_pending */
1713
1714 /* Do protocol field compression */
1715 p = skb->data;
1716 len = skb->len;
1717 if (*p == 0 && mp_protocol_compress) {
1718 ++p;
1719 --len;
1720 }
1721
1722 totlen = len;
1723 nbigger = len % nfree;
1724
1725 /* skip to the channel after the one we last used
1726 and start at that one */
1727 list = &ppp->channels;
1728 for (i = 0; i < ppp->nxchan; ++i) {
1729 list = list->next;
1730 if (list == &ppp->channels) {
1731 i = 0;
1732 break;
1733 }
1734 }
1735
1736 /* create a fragment for each channel */
1737 bits = B;
1738 while (len > 0) {
1739 list = list->next;
1740 if (list == &ppp->channels) {
1741 i = 0;
1742 continue;
1743 }
1744 pch = list_entry(list, struct channel, clist);
1745 ++i;
1746 if (!pch->avail)
1747 continue;
1748
1749 /*
1750 * Skip this channel if it has a fragment pending already and
1751 * we haven't given a fragment to all of the free channels.
1752 */
1753 if (pch->avail == 1) {
1754 if (nfree > 0)
1755 continue;
1756 } else {
1757 pch->avail = 1;
1758 }
1759
1760 /* check the channel's mtu and whether it is still attached. */
1761 spin_lock_bh(&pch->downl);
1762 if (pch->chan == NULL) {
1763 /* can't use this channel, it's being deregistered */
1764 if (pch->speed == 0)
1765 nzero--;
1766 else
1767 totspeed -= pch->speed;
1768
1769 spin_unlock_bh(&pch->downl);
1770 pch->avail = 0;
1771 totlen = len;
1772 totfree--;
1773 nfree--;
1774 if (--navail == 0)
1775 break;
1776 continue;
1777 }
1778
1779 /*
1780 *if the channel speed is not set divide
1781 *the packet evenly among the free channels;
1782 *otherwise divide it according to the speed
1783 *of the channel we are going to transmit on
1784 */
1785 flen = len;
1786 if (nfree > 0) {
1787 if (pch->speed == 0) {
1788 flen = len/nfree;
1789 if (nbigger > 0) {
1790 flen++;
1791 nbigger--;
1792 }
1793 } else {
1794 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
1795 ((totspeed*totfree)/pch->speed)) - hdrlen;
1796 if (nbigger > 0) {
1797 flen += ((totfree - nzero)*pch->speed)/totspeed;
1798 nbigger -= ((totfree - nzero)*pch->speed)/
1799 totspeed;
1800 }
1801 }
1802 nfree--;
1803 }
1804
1805 /*
1806 *check if we are on the last channel or
1807 *we exceded the length of the data to
1808 *fragment
1809 */
1810 if ((nfree <= 0) || (flen > len))
1811 flen = len;
1812 /*
1813 *it is not worth to tx on slow channels:
1814 *in that case from the resulting flen according to the
1815 *above formula will be equal or less than zero.
1816 *Skip the channel in this case
1817 */
1818 if (flen <= 0) {
1819 pch->avail = 2;
1820 spin_unlock_bh(&pch->downl);
1821 continue;
1822 }
1823
1824 /*
1825 * hdrlen includes the 2-byte PPP protocol field, but the
1826 * MTU counts only the payload excluding the protocol field.
1827 * (RFC1661 Section 2)
1828 */
1829 mtu = pch->chan->mtu - (hdrlen - 2);
1830 if (mtu < 4)
1831 mtu = 4;
1832 if (flen > mtu)
1833 flen = mtu;
1834 if (flen == len)
1835 bits |= E;
1836 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1837 if (!frag)
1838 goto noskb;
1839 q = skb_put(frag, flen + hdrlen);
1840
1841 /* make the MP header */
1842 put_unaligned_be16(PPP_MP, q);
1843 if (ppp->flags & SC_MP_XSHORTSEQ) {
1844 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1845 q[3] = ppp->nxseq;
1846 } else {
1847 q[2] = bits;
1848 q[3] = ppp->nxseq >> 16;
1849 q[4] = ppp->nxseq >> 8;
1850 q[5] = ppp->nxseq;
1851 }
1852
1853 memcpy(q + hdrlen, p, flen);
1854
1855 /* try to send it down the channel */
1856 chan = pch->chan;
1857 if (!skb_queue_empty(&pch->file.xq) ||
1858 !chan->ops->start_xmit(chan, frag))
1859 skb_queue_tail(&pch->file.xq, frag);
1860 pch->had_frag = 1;
1861 p += flen;
1862 len -= flen;
1863 ++ppp->nxseq;
1864 bits = 0;
1865 spin_unlock_bh(&pch->downl);
1866 }
1867 ppp->nxchan = i;
1868
1869 return 1;
1870
1871 noskb:
1872 spin_unlock_bh(&pch->downl);
1873 if (ppp->debug & 1)
1874 netdev_err(ppp->dev, "PPP: no memory (fragment)\n");
1875 ++ppp->dev->stats.tx_errors;
1876 ++ppp->nxseq;
1877 return 1; /* abandon the frame */
1878 }
1879 #endif /* CONFIG_PPP_MULTILINK */
1880
1881 /* Try to send data out on a channel */
1882 static void __ppp_channel_push(struct channel *pch)
1883 {
1884 struct sk_buff *skb;
1885 struct ppp *ppp;
1886
1887 spin_lock_bh(&pch->downl);
1888 if (pch->chan) {
1889 while (!skb_queue_empty(&pch->file.xq)) {
1890 skb = skb_dequeue(&pch->file.xq);
1891 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1892 /* put the packet back and try again later */
1893 skb_queue_head(&pch->file.xq, skb);
1894 break;
1895 }
1896 }
1897 } else {
1898 /* channel got deregistered */
1899 skb_queue_purge(&pch->file.xq);
1900 }
1901 spin_unlock_bh(&pch->downl);
1902 /* see if there is anything from the attached unit to be sent */
1903 if (skb_queue_empty(&pch->file.xq)) {
1904 read_lock_bh(&pch->upl);
1905 ppp = pch->ppp;
1906 if (ppp)
1907 __ppp_xmit_process(ppp);
1908 read_unlock_bh(&pch->upl);
1909 }
1910 }
1911
1912 static void ppp_channel_push(struct channel *pch)
1913 {
1914 local_bh_disable();
1915
1916 __this_cpu_inc(ppp_xmit_recursion);
1917 __ppp_channel_push(pch);
1918 __this_cpu_dec(ppp_xmit_recursion);
1919
1920 local_bh_enable();
1921 }
1922
1923 /*
1924 * Receive-side routines.
1925 */
1926
1927 struct ppp_mp_skb_parm {
1928 u32 sequence;
1929 u8 BEbits;
1930 };
1931 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb))
1932
1933 static inline void
1934 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1935 {
1936 ppp_recv_lock(ppp);
1937 if (!ppp->closing)
1938 ppp_receive_frame(ppp, skb, pch);
1939 else
1940 kfree_skb(skb);
1941 ppp_recv_unlock(ppp);
1942 }
1943
1944 void
1945 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1946 {
1947 struct channel *pch = chan->ppp;
1948 int proto;
1949
1950 if (!pch) {
1951 kfree_skb(skb);
1952 return;
1953 }
1954
1955 read_lock_bh(&pch->upl);
1956 if (!pskb_may_pull(skb, 2)) {
1957 kfree_skb(skb);
1958 if (pch->ppp) {
1959 ++pch->ppp->dev->stats.rx_length_errors;
1960 ppp_receive_error(pch->ppp);
1961 }
1962 goto done;
1963 }
1964
1965 proto = PPP_PROTO(skb);
1966 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1967 /* put it on the channel queue */
1968 skb_queue_tail(&pch->file.rq, skb);
1969 /* drop old frames if queue too long */
1970 while (pch->file.rq.qlen > PPP_MAX_RQLEN &&
1971 (skb = skb_dequeue(&pch->file.rq)))
1972 kfree_skb(skb);
1973 wake_up_interruptible(&pch->file.rwait);
1974 } else {
1975 ppp_do_recv(pch->ppp, skb, pch);
1976 }
1977
1978 done:
1979 read_unlock_bh(&pch->upl);
1980 }
1981
1982 /* Put a 0-length skb in the receive queue as an error indication */
1983 void
1984 ppp_input_error(struct ppp_channel *chan, int code)
1985 {
1986 struct channel *pch = chan->ppp;
1987 struct sk_buff *skb;
1988
1989 if (!pch)
1990 return;
1991
1992 read_lock_bh(&pch->upl);
1993 if (pch->ppp) {
1994 skb = alloc_skb(0, GFP_ATOMIC);
1995 if (skb) {
1996 skb->len = 0; /* probably unnecessary */
1997 skb->cb[0] = code;
1998 ppp_do_recv(pch->ppp, skb, pch);
1999 }
2000 }
2001 read_unlock_bh(&pch->upl);
2002 }
2003
2004 /*
2005 * We come in here to process a received frame.
2006 * The receive side of the ppp unit is locked.
2007 */
2008 static void
2009 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
2010 {
2011 /* note: a 0-length skb is used as an error indication */
2012 if (skb->len > 0) {
2013 skb_checksum_complete_unset(skb);
2014 #ifdef CONFIG_PPP_MULTILINK
2015 /* XXX do channel-level decompression here */
2016 if (PPP_PROTO(skb) == PPP_MP)
2017 ppp_receive_mp_frame(ppp, skb, pch);
2018 else
2019 #endif /* CONFIG_PPP_MULTILINK */
2020 ppp_receive_nonmp_frame(ppp, skb);
2021 } else {
2022 kfree_skb(skb);
2023 ppp_receive_error(ppp);
2024 }
2025 }
2026
2027 static void
2028 ppp_receive_error(struct ppp *ppp)
2029 {
2030 ++ppp->dev->stats.rx_errors;
2031 if (ppp->vj)
2032 slhc_toss(ppp->vj);
2033 }
2034
2035 static void
2036 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
2037 {
2038 struct sk_buff *ns;
2039 int proto, len, npi;
2040
2041 /*
2042 * Decompress the frame, if compressed.
2043 * Note that some decompressors need to see uncompressed frames
2044 * that come in as well as compressed frames.
2045 */
2046 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) &&
2047 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
2048 skb = ppp_decompress_frame(ppp, skb);
2049
2050 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
2051 goto err;
2052
2053 proto = PPP_PROTO(skb);
2054 switch (proto) {
2055 case PPP_VJC_COMP:
2056 /* decompress VJ compressed packets */
2057 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
2058 goto err;
2059
2060 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
2061 /* copy to a new sk_buff with more tailroom */
2062 ns = dev_alloc_skb(skb->len + 128);
2063 if (!ns) {
2064 netdev_err(ppp->dev, "PPP: no memory "
2065 "(VJ decomp)\n");
2066 goto err;
2067 }
2068 skb_reserve(ns, 2);
2069 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
2070 consume_skb(skb);
2071 skb = ns;
2072 }
2073 else
2074 skb->ip_summed = CHECKSUM_NONE;
2075
2076 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
2077 if (len <= 0) {
2078 netdev_printk(KERN_DEBUG, ppp->dev,
2079 "PPP: VJ decompression error\n");
2080 goto err;
2081 }
2082 len += 2;
2083 if (len > skb->len)
2084 skb_put(skb, len - skb->len);
2085 else if (len < skb->len)
2086 skb_trim(skb, len);
2087 proto = PPP_IP;
2088 break;
2089
2090 case PPP_VJC_UNCOMP:
2091 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
2092 goto err;
2093
2094 /* Until we fix the decompressor need to make sure
2095 * data portion is linear.
2096 */
2097 if (!pskb_may_pull(skb, skb->len))
2098 goto err;
2099
2100 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
2101 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n");
2102 goto err;
2103 }
2104 proto = PPP_IP;
2105 break;
2106
2107 case PPP_CCP:
2108 ppp_ccp_peek(ppp, skb, 1);
2109 break;
2110 }
2111
2112 ++ppp->stats64.rx_packets;
2113 ppp->stats64.rx_bytes += skb->len - 2;
2114
2115 npi = proto_to_npindex(proto);
2116 if (npi < 0) {
2117 /* control or unknown frame - pass it to pppd */
2118 skb_queue_tail(&ppp->file.rq, skb);
2119 /* limit queue length by dropping old frames */
2120 while (ppp->file.rq.qlen > PPP_MAX_RQLEN &&
2121 (skb = skb_dequeue(&ppp->file.rq)))
2122 kfree_skb(skb);
2123 /* wake up any process polling or blocking on read */
2124 wake_up_interruptible(&ppp->file.rwait);
2125
2126 } else {
2127 /* network protocol frame - give it to the kernel */
2128
2129 #ifdef CONFIG_PPP_FILTER
2130 /* check if the packet passes the pass and active filters */
2131 /* the filter instructions are constructed assuming
2132 a four-byte PPP header on each packet */
2133 if (ppp->pass_filter || ppp->active_filter) {
2134 if (skb_unclone(skb, GFP_ATOMIC))
2135 goto err;
2136
2137 *skb_push(skb, 2) = 0;
2138 if (ppp->pass_filter &&
2139 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
2140 if (ppp->debug & 1)
2141 netdev_printk(KERN_DEBUG, ppp->dev,
2142 "PPP: inbound frame "
2143 "not passed\n");
2144 kfree_skb(skb);
2145 return;
2146 }
2147 if (!(ppp->active_filter &&
2148 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
2149 ppp->last_recv = jiffies;
2150 __skb_pull(skb, 2);
2151 } else
2152 #endif /* CONFIG_PPP_FILTER */
2153 ppp->last_recv = jiffies;
2154
2155 if ((ppp->dev->flags & IFF_UP) == 0 ||
2156 ppp->npmode[npi] != NPMODE_PASS) {
2157 kfree_skb(skb);
2158 } else {
2159 /* chop off protocol */
2160 skb_pull_rcsum(skb, 2);
2161 skb->dev = ppp->dev;
2162 skb->protocol = htons(npindex_to_ethertype[npi]);
2163 skb_reset_mac_header(skb);
2164 skb_scrub_packet(skb, !net_eq(ppp->ppp_net,
2165 dev_net(ppp->dev)));
2166 netif_rx(skb);
2167 }
2168 }
2169 return;
2170
2171 err:
2172 kfree_skb(skb);
2173 ppp_receive_error(ppp);
2174 }
2175
2176 static struct sk_buff *
2177 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
2178 {
2179 int proto = PPP_PROTO(skb);
2180 struct sk_buff *ns;
2181 int len;
2182
2183 /* Until we fix all the decompressor's need to make sure
2184 * data portion is linear.
2185 */
2186 if (!pskb_may_pull(skb, skb->len))
2187 goto err;
2188
2189 if (proto == PPP_COMP) {
2190 int obuff_size;
2191
2192 switch(ppp->rcomp->compress_proto) {
2193 case CI_MPPE:
2194 obuff_size = ppp->mru + PPP_HDRLEN + 1;
2195 break;
2196 default:
2197 obuff_size = ppp->mru + PPP_HDRLEN;
2198 break;
2199 }
2200
2201 ns = dev_alloc_skb(obuff_size);
2202 if (!ns) {
2203 netdev_err(ppp->dev, "ppp_decompress_frame: "
2204 "no memory\n");
2205 goto err;
2206 }
2207 /* the decompressor still expects the A/C bytes in the hdr */
2208 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
2209 skb->len + 2, ns->data, obuff_size);
2210 if (len < 0) {
2211 /* Pass the compressed frame to pppd as an
2212 error indication. */
2213 if (len == DECOMP_FATALERROR)
2214 ppp->rstate |= SC_DC_FERROR;
2215 kfree_skb(ns);
2216 goto err;
2217 }
2218
2219 consume_skb(skb);
2220 skb = ns;
2221 skb_put(skb, len);
2222 skb_pull(skb, 2); /* pull off the A/C bytes */
2223
2224 } else {
2225 /* Uncompressed frame - pass to decompressor so it
2226 can update its dictionary if necessary. */
2227 if (ppp->rcomp->incomp)
2228 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
2229 skb->len + 2);
2230 }
2231
2232 return skb;
2233
2234 err:
2235 ppp->rstate |= SC_DC_ERROR;
2236 ppp_receive_error(ppp);
2237 return skb;
2238 }
2239
2240 #ifdef CONFIG_PPP_MULTILINK
2241 /*
2242 * Receive a multilink frame.
2243 * We put it on the reconstruction queue and then pull off
2244 * as many completed frames as we can.
2245 */
2246 static void
2247 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
2248 {
2249 u32 mask, seq;
2250 struct channel *ch;
2251 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
2252
2253 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
2254 goto err; /* no good, throw it away */
2255
2256 /* Decode sequence number and begin/end bits */
2257 if (ppp->flags & SC_MP_SHORTSEQ) {
2258 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
2259 mask = 0xfff;
2260 } else {
2261 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
2262 mask = 0xffffff;
2263 }
2264 PPP_MP_CB(skb)->BEbits = skb->data[2];
2265 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
2266
2267 /*
2268 * Do protocol ID decompression on the first fragment of each packet.
2269 */
2270 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1))
2271 *skb_push(skb, 1) = 0;
2272
2273 /*
2274 * Expand sequence number to 32 bits, making it as close
2275 * as possible to ppp->minseq.
2276 */
2277 seq |= ppp->minseq & ~mask;
2278 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
2279 seq += mask + 1;
2280 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
2281 seq -= mask + 1; /* should never happen */
2282 PPP_MP_CB(skb)->sequence = seq;
2283 pch->lastseq = seq;
2284
2285 /*
2286 * If this packet comes before the next one we were expecting,
2287 * drop it.
2288 */
2289 if (seq_before(seq, ppp->nextseq)) {
2290 kfree_skb(skb);
2291 ++ppp->dev->stats.rx_dropped;
2292 ppp_receive_error(ppp);
2293 return;
2294 }
2295
2296 /*
2297 * Reevaluate minseq, the minimum over all channels of the
2298 * last sequence number received on each channel. Because of
2299 * the increasing sequence number rule, we know that any fragment
2300 * before `minseq' which hasn't arrived is never going to arrive.
2301 * The list of channels can't change because we have the receive
2302 * side of the ppp unit locked.
2303 */
2304 list_for_each_entry(ch, &ppp->channels, clist) {
2305 if (seq_before(ch->lastseq, seq))
2306 seq = ch->lastseq;
2307 }
2308 if (seq_before(ppp->minseq, seq))
2309 ppp->minseq = seq;
2310
2311 /* Put the fragment on the reconstruction queue */
2312 ppp_mp_insert(ppp, skb);
2313
2314 /* If the queue is getting long, don't wait any longer for packets
2315 before the start of the queue. */
2316 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
2317 struct sk_buff *mskb = skb_peek(&ppp->mrq);
2318 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence))
2319 ppp->minseq = PPP_MP_CB(mskb)->sequence;
2320 }
2321
2322 /* Pull completed packets off the queue and receive them. */
2323 while ((skb = ppp_mp_reconstruct(ppp))) {
2324 if (pskb_may_pull(skb, 2))
2325 ppp_receive_nonmp_frame(ppp, skb);
2326 else {
2327 ++ppp->dev->stats.rx_length_errors;
2328 kfree_skb(skb);
2329 ppp_receive_error(ppp);
2330 }
2331 }
2332
2333 return;
2334
2335 err:
2336 kfree_skb(skb);
2337 ppp_receive_error(ppp);
2338 }
2339
2340 /*
2341 * Insert a fragment on the MP reconstruction queue.
2342 * The queue is ordered by increasing sequence number.
2343 */
2344 static void
2345 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
2346 {
2347 struct sk_buff *p;
2348 struct sk_buff_head *list = &ppp->mrq;
2349 u32 seq = PPP_MP_CB(skb)->sequence;
2350
2351 /* N.B. we don't need to lock the list lock because we have the
2352 ppp unit receive-side lock. */
2353 skb_queue_walk(list, p) {
2354 if (seq_before(seq, PPP_MP_CB(p)->sequence))
2355 break;
2356 }
2357 __skb_queue_before(list, p, skb);
2358 }
2359
2360 /*
2361 * Reconstruct a packet from the MP fragment queue.
2362 * We go through increasing sequence numbers until we find a
2363 * complete packet, or we get to the sequence number for a fragment
2364 * which hasn't arrived but might still do so.
2365 */
2366 static struct sk_buff *
2367 ppp_mp_reconstruct(struct ppp *ppp)
2368 {
2369 u32 seq = ppp->nextseq;
2370 u32 minseq = ppp->minseq;
2371 struct sk_buff_head *list = &ppp->mrq;
2372 struct sk_buff *p, *tmp;
2373 struct sk_buff *head, *tail;
2374 struct sk_buff *skb = NULL;
2375 int lost = 0, len = 0;
2376
2377 if (ppp->mrru == 0) /* do nothing until mrru is set */
2378 return NULL;
2379 head = list->next;
2380 tail = NULL;
2381 skb_queue_walk_safe(list, p, tmp) {
2382 again:
2383 if (seq_before(PPP_MP_CB(p)->sequence, seq)) {
2384 /* this can't happen, anyway ignore the skb */
2385 netdev_err(ppp->dev, "ppp_mp_reconstruct bad "
2386 "seq %u < %u\n",
2387 PPP_MP_CB(p)->sequence, seq);
2388 __skb_unlink(p, list);
2389 kfree_skb(p);
2390 continue;
2391 }
2392 if (PPP_MP_CB(p)->sequence != seq) {
2393 u32 oldseq;
2394 /* Fragment `seq' is missing. If it is after
2395 minseq, it might arrive later, so stop here. */
2396 if (seq_after(seq, minseq))
2397 break;
2398 /* Fragment `seq' is lost, keep going. */
2399 lost = 1;
2400 oldseq = seq;
2401 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)?
2402 minseq + 1: PPP_MP_CB(p)->sequence;
2403
2404 if (ppp->debug & 1)
2405 netdev_printk(KERN_DEBUG, ppp->dev,
2406 "lost frag %u..%u\n",
2407 oldseq, seq-1);
2408
2409 goto again;
2410 }
2411
2412 /*
2413 * At this point we know that all the fragments from
2414 * ppp->nextseq to seq are either present or lost.
2415 * Also, there are no complete packets in the queue
2416 * that have no missing fragments and end before this
2417 * fragment.
2418 */
2419
2420 /* B bit set indicates this fragment starts a packet */
2421 if (PPP_MP_CB(p)->BEbits & B) {
2422 head = p;
2423 lost = 0;
2424 len = 0;
2425 }
2426
2427 len += p->len;
2428
2429 /* Got a complete packet yet? */
2430 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) &&
2431 (PPP_MP_CB(head)->BEbits & B)) {
2432 if (len > ppp->mrru + 2) {
2433 ++ppp->dev->stats.rx_length_errors;
2434 netdev_printk(KERN_DEBUG, ppp->dev,
2435 "PPP: reconstructed packet"
2436 " is too long (%d)\n", len);
2437 } else {
2438 tail = p;
2439 break;
2440 }
2441 ppp->nextseq = seq + 1;
2442 }
2443
2444 /*
2445 * If this is the ending fragment of a packet,
2446 * and we haven't found a complete valid packet yet,
2447 * we can discard up to and including this fragment.
2448 */
2449 if (PPP_MP_CB(p)->BEbits & E) {
2450 struct sk_buff *tmp2;
2451
2452 skb_queue_reverse_walk_from_safe(list, p, tmp2) {
2453 if (ppp->debug & 1)
2454 netdev_printk(KERN_DEBUG, ppp->dev,
2455 "discarding frag %u\n",
2456 PPP_MP_CB(p)->sequence);
2457 __skb_unlink(p, list);
2458 kfree_skb(p);
2459 }
2460 head = skb_peek(list);
2461 if (!head)
2462 break;
2463 }
2464 ++seq;
2465 }
2466
2467 /* If we have a complete packet, copy it all into one skb. */
2468 if (tail != NULL) {
2469 /* If we have discarded any fragments,
2470 signal a receive error. */
2471 if (PPP_MP_CB(head)->sequence != ppp->nextseq) {
2472 skb_queue_walk_safe(list, p, tmp) {
2473 if (p == head)
2474 break;
2475 if (ppp->debug & 1)
2476 netdev_printk(KERN_DEBUG, ppp->dev,
2477 "discarding frag %u\n",
2478 PPP_MP_CB(p)->sequence);
2479 __skb_unlink(p, list);
2480 kfree_skb(p);
2481 }
2482
2483 if (ppp->debug & 1)
2484 netdev_printk(KERN_DEBUG, ppp->dev,
2485 " missed pkts %u..%u\n",
2486 ppp->nextseq,
2487 PPP_MP_CB(head)->sequence-1);
2488 ++ppp->dev->stats.rx_dropped;
2489 ppp_receive_error(ppp);
2490 }
2491
2492 skb = head;
2493 if (head != tail) {
2494 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list;
2495 p = skb_queue_next(list, head);
2496 __skb_unlink(skb, list);
2497 skb_queue_walk_from_safe(list, p, tmp) {
2498 __skb_unlink(p, list);
2499 *fragpp = p;
2500 p->next = NULL;
2501 fragpp = &p->next;
2502
2503 skb->len += p->len;
2504 skb->data_len += p->len;
2505 skb->truesize += p->truesize;
2506
2507 if (p == tail)
2508 break;
2509 }
2510 } else {
2511 __skb_unlink(skb, list);
2512 }
2513
2514 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1;
2515 }
2516
2517 return skb;
2518 }
2519 #endif /* CONFIG_PPP_MULTILINK */
2520
2521 /*
2522 * Channel interface.
2523 */
2524
2525 /* Create a new, unattached ppp channel. */
2526 int ppp_register_channel(struct ppp_channel *chan)
2527 {
2528 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2529 }
2530
2531 /* Create a new, unattached ppp channel for specified net. */
2532 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
2533 {
2534 struct channel *pch;
2535 struct ppp_net *pn;
2536
2537 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2538 if (!pch)
2539 return -ENOMEM;
2540
2541 pn = ppp_pernet(net);
2542
2543 pch->ppp = NULL;
2544 pch->chan = chan;
2545 pch->chan_net = get_net(net);
2546 chan->ppp = pch;
2547 init_ppp_file(&pch->file, CHANNEL);
2548 pch->file.hdrlen = chan->hdrlen;
2549 #ifdef CONFIG_PPP_MULTILINK
2550 pch->lastseq = -1;
2551 #endif /* CONFIG_PPP_MULTILINK */
2552 init_rwsem(&pch->chan_sem);
2553 spin_lock_init(&pch->downl);
2554 rwlock_init(&pch->upl);
2555
2556 spin_lock_bh(&pn->all_channels_lock);
2557 pch->file.index = ++pn->last_channel_index;
2558 list_add(&pch->list, &pn->new_channels);
2559 atomic_inc(&channel_count);
2560 spin_unlock_bh(&pn->all_channels_lock);
2561
2562 return 0;
2563 }
2564
2565 /*
2566 * Return the index of a channel.
2567 */
2568 int ppp_channel_index(struct ppp_channel *chan)
2569 {
2570 struct channel *pch = chan->ppp;
2571
2572 if (pch)
2573 return pch->file.index;
2574 return -1;
2575 }
2576
2577 /*
2578 * Return the PPP unit number to which a channel is connected.
2579 */
2580 int ppp_unit_number(struct ppp_channel *chan)
2581 {
2582 struct channel *pch = chan->ppp;
2583 int unit = -1;
2584
2585 if (pch) {
2586 read_lock_bh(&pch->upl);
2587 if (pch->ppp)
2588 unit = pch->ppp->file.index;
2589 read_unlock_bh(&pch->upl);
2590 }
2591 return unit;
2592 }
2593
2594 /*
2595 * Return the PPP device interface name of a channel.
2596 */
2597 char *ppp_dev_name(struct ppp_channel *chan)
2598 {
2599 struct channel *pch = chan->ppp;
2600 char *name = NULL;
2601
2602 if (pch) {
2603 read_lock_bh(&pch->upl);
2604 if (pch->ppp && pch->ppp->dev)
2605 name = pch->ppp->dev->name;
2606 read_unlock_bh(&pch->upl);
2607 }
2608 return name;
2609 }
2610
2611
2612 /*
2613 * Disconnect a channel from the generic layer.
2614 * This must be called in process context.
2615 */
2616 void
2617 ppp_unregister_channel(struct ppp_channel *chan)
2618 {
2619 struct channel *pch = chan->ppp;
2620 struct ppp_net *pn;
2621
2622 if (!pch)
2623 return; /* should never happen */
2624
2625 chan->ppp = NULL;
2626
2627 /*
2628 * This ensures that we have returned from any calls into the
2629 * the channel's start_xmit or ioctl routine before we proceed.
2630 */
2631 down_write(&pch->chan_sem);
2632 spin_lock_bh(&pch->downl);
2633 pch->chan = NULL;
2634 spin_unlock_bh(&pch->downl);
2635 up_write(&pch->chan_sem);
2636 ppp_disconnect_channel(pch);
2637
2638 pn = ppp_pernet(pch->chan_net);
2639 spin_lock_bh(&pn->all_channels_lock);
2640 list_del(&pch->list);
2641 spin_unlock_bh(&pn->all_channels_lock);
2642
2643 pch->file.dead = 1;
2644 wake_up_interruptible(&pch->file.rwait);
2645 if (atomic_dec_and_test(&pch->file.refcnt))
2646 ppp_destroy_channel(pch);
2647 }
2648
2649 /*
2650 * Callback from a channel when it can accept more to transmit.
2651 * This should be called at BH/softirq level, not interrupt level.
2652 */
2653 void
2654 ppp_output_wakeup(struct ppp_channel *chan)
2655 {
2656 struct channel *pch = chan->ppp;
2657
2658 if (!pch)
2659 return;
2660 ppp_channel_push(pch);
2661 }
2662
2663 /*
2664 * Compression control.
2665 */
2666
2667 /* Process the PPPIOCSCOMPRESS ioctl. */
2668 static int
2669 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2670 {
2671 int err;
2672 struct compressor *cp, *ocomp;
2673 struct ppp_option_data data;
2674 void *state, *ostate;
2675 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2676
2677 err = -EFAULT;
2678 if (copy_from_user(&data, (void __user *) arg, sizeof(data)))
2679 goto out;
2680 if (data.length > CCP_MAX_OPTION_LENGTH)
2681 goto out;
2682 if (copy_from_user(ccp_option, (void __user *) data.ptr, data.length))
2683 goto out;
2684
2685 err = -EINVAL;
2686 if (data.length < 2 || ccp_option[1] < 2 || ccp_option[1] > data.length)
2687 goto out;
2688
2689 cp = try_then_request_module(
2690 find_compressor(ccp_option[0]),
2691 "ppp-compress-%d", ccp_option[0]);
2692 if (!cp)
2693 goto out;
2694
2695 err = -ENOBUFS;
2696 if (data.transmit) {
2697 state = cp->comp_alloc(ccp_option, data.length);
2698 if (state) {
2699 ppp_xmit_lock(ppp);
2700 ppp->xstate &= ~SC_COMP_RUN;
2701 ocomp = ppp->xcomp;
2702 ostate = ppp->xc_state;
2703 ppp->xcomp = cp;
2704 ppp->xc_state = state;
2705 ppp_xmit_unlock(ppp);
2706 if (ostate) {
2707 ocomp->comp_free(ostate);
2708 module_put(ocomp->owner);
2709 }
2710 err = 0;
2711 } else
2712 module_put(cp->owner);
2713
2714 } else {
2715 state = cp->decomp_alloc(ccp_option, data.length);
2716 if (state) {
2717 ppp_recv_lock(ppp);
2718 ppp->rstate &= ~SC_DECOMP_RUN;
2719 ocomp = ppp->rcomp;
2720 ostate = ppp->rc_state;
2721 ppp->rcomp = cp;
2722 ppp->rc_state = state;
2723 ppp_recv_unlock(ppp);
2724 if (ostate) {
2725 ocomp->decomp_free(ostate);
2726 module_put(ocomp->owner);
2727 }
2728 err = 0;
2729 } else
2730 module_put(cp->owner);
2731 }
2732
2733 out:
2734 return err;
2735 }
2736
2737 /*
2738 * Look at a CCP packet and update our state accordingly.
2739 * We assume the caller has the xmit or recv path locked.
2740 */
2741 static void
2742 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2743 {
2744 unsigned char *dp;
2745 int len;
2746
2747 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2748 return; /* no header */
2749 dp = skb->data + 2;
2750
2751 switch (CCP_CODE(dp)) {
2752 case CCP_CONFREQ:
2753
2754 /* A ConfReq starts negotiation of compression
2755 * in one direction of transmission,
2756 * and hence brings it down...but which way?
2757 *
2758 * Remember:
2759 * A ConfReq indicates what the sender would like to receive
2760 */
2761 if(inbound)
2762 /* He is proposing what I should send */
2763 ppp->xstate &= ~SC_COMP_RUN;
2764 else
2765 /* I am proposing to what he should send */
2766 ppp->rstate &= ~SC_DECOMP_RUN;
2767
2768 break;
2769
2770 case CCP_TERMREQ:
2771 case CCP_TERMACK:
2772 /*
2773 * CCP is going down, both directions of transmission
2774 */
2775 ppp->rstate &= ~SC_DECOMP_RUN;
2776 ppp->xstate &= ~SC_COMP_RUN;
2777 break;
2778
2779 case CCP_CONFACK:
2780 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2781 break;
2782 len = CCP_LENGTH(dp);
2783 if (!pskb_may_pull(skb, len + 2))
2784 return; /* too short */
2785 dp += CCP_HDRLEN;
2786 len -= CCP_HDRLEN;
2787 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2788 break;
2789 if (inbound) {
2790 /* we will start receiving compressed packets */
2791 if (!ppp->rc_state)
2792 break;
2793 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2794 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2795 ppp->rstate |= SC_DECOMP_RUN;
2796 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2797 }
2798 } else {
2799 /* we will soon start sending compressed packets */
2800 if (!ppp->xc_state)
2801 break;
2802 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2803 ppp->file.index, 0, ppp->debug))
2804 ppp->xstate |= SC_COMP_RUN;
2805 }
2806 break;
2807
2808 case CCP_RESETACK:
2809 /* reset the [de]compressor */
2810 if ((ppp->flags & SC_CCP_UP) == 0)
2811 break;
2812 if (inbound) {
2813 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2814 ppp->rcomp->decomp_reset(ppp->rc_state);
2815 ppp->rstate &= ~SC_DC_ERROR;
2816 }
2817 } else {
2818 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2819 ppp->xcomp->comp_reset(ppp->xc_state);
2820 }
2821 break;
2822 }
2823 }
2824
2825 /* Free up compression resources. */
2826 static void
2827 ppp_ccp_closed(struct ppp *ppp)
2828 {
2829 void *xstate, *rstate;
2830 struct compressor *xcomp, *rcomp;
2831
2832 ppp_lock(ppp);
2833 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2834 ppp->xstate = 0;
2835 xcomp = ppp->xcomp;
2836 xstate = ppp->xc_state;
2837 ppp->xc_state = NULL;
2838 ppp->rstate = 0;
2839 rcomp = ppp->rcomp;
2840 rstate = ppp->rc_state;
2841 ppp->rc_state = NULL;
2842 ppp_unlock(ppp);
2843
2844 if (xstate) {
2845 xcomp->comp_free(xstate);
2846 module_put(xcomp->owner);
2847 }
2848 if (rstate) {
2849 rcomp->decomp_free(rstate);
2850 module_put(rcomp->owner);
2851 }
2852 }
2853
2854 /* List of compressors. */
2855 static LIST_HEAD(compressor_list);
2856 static DEFINE_SPINLOCK(compressor_list_lock);
2857
2858 struct compressor_entry {
2859 struct list_head list;
2860 struct compressor *comp;
2861 };
2862
2863 static struct compressor_entry *
2864 find_comp_entry(int proto)
2865 {
2866 struct compressor_entry *ce;
2867
2868 list_for_each_entry(ce, &compressor_list, list) {
2869 if (ce->comp->compress_proto == proto)
2870 return ce;
2871 }
2872 return NULL;
2873 }
2874
2875 /* Register a compressor */
2876 int
2877 ppp_register_compressor(struct compressor *cp)
2878 {
2879 struct compressor_entry *ce;
2880 int ret;
2881 spin_lock(&compressor_list_lock);
2882 ret = -EEXIST;
2883 if (find_comp_entry(cp->compress_proto))
2884 goto out;
2885 ret = -ENOMEM;
2886 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2887 if (!ce)
2888 goto out;
2889 ret = 0;
2890 ce->comp = cp;
2891 list_add(&ce->list, &compressor_list);
2892 out:
2893 spin_unlock(&compressor_list_lock);
2894 return ret;
2895 }
2896
2897 /* Unregister a compressor */
2898 void
2899 ppp_unregister_compressor(struct compressor *cp)
2900 {
2901 struct compressor_entry *ce;
2902
2903 spin_lock(&compressor_list_lock);
2904 ce = find_comp_entry(cp->compress_proto);
2905 if (ce && ce->comp == cp) {
2906 list_del(&ce->list);
2907 kfree(ce);
2908 }
2909 spin_unlock(&compressor_list_lock);
2910 }
2911
2912 /* Find a compressor. */
2913 static struct compressor *
2914 find_compressor(int type)
2915 {
2916 struct compressor_entry *ce;
2917 struct compressor *cp = NULL;
2918
2919 spin_lock(&compressor_list_lock);
2920 ce = find_comp_entry(type);
2921 if (ce) {
2922 cp = ce->comp;
2923 if (!try_module_get(cp->owner))
2924 cp = NULL;
2925 }
2926 spin_unlock(&compressor_list_lock);
2927 return cp;
2928 }
2929
2930 /*
2931 * Miscelleneous stuff.
2932 */
2933
2934 static void
2935 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2936 {
2937 struct slcompress *vj = ppp->vj;
2938
2939 memset(st, 0, sizeof(*st));
2940 st->p.ppp_ipackets = ppp->stats64.rx_packets;
2941 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2942 st->p.ppp_ibytes = ppp->stats64.rx_bytes;
2943 st->p.ppp_opackets = ppp->stats64.tx_packets;
2944 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2945 st->p.ppp_obytes = ppp->stats64.tx_bytes;
2946 if (!vj)
2947 return;
2948 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2949 st->vj.vjs_compressed = vj->sls_o_compressed;
2950 st->vj.vjs_searches = vj->sls_o_searches;
2951 st->vj.vjs_misses = vj->sls_o_misses;
2952 st->vj.vjs_errorin = vj->sls_i_error;
2953 st->vj.vjs_tossed = vj->sls_i_tossed;
2954 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2955 st->vj.vjs_compressedin = vj->sls_i_compressed;
2956 }
2957
2958 /*
2959 * Stuff for handling the lists of ppp units and channels
2960 * and for initialization.
2961 */
2962
2963 /*
2964 * Create a new ppp interface unit. Fails if it can't allocate memory
2965 * or if there is already a unit with the requested number.
2966 * unit == -1 means allocate a new number.
2967 */
2968 static int ppp_create_interface(struct net *net, struct file *file, int *unit)
2969 {
2970 struct ppp_config conf = {
2971 .file = file,
2972 .unit = *unit,
2973 .ifname_is_set = false,
2974 };
2975 struct net_device *dev;
2976 struct ppp *ppp;
2977 int err;
2978
2979 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_ENUM, ppp_setup);
2980 if (!dev) {
2981 err = -ENOMEM;
2982 goto err;
2983 }
2984 dev_net_set(dev, net);
2985 dev->rtnl_link_ops = &ppp_link_ops;
2986
2987 rtnl_lock();
2988
2989 err = ppp_dev_configure(net, dev, &conf);
2990 if (err < 0)
2991 goto err_dev;
2992 ppp = netdev_priv(dev);
2993 *unit = ppp->file.index;
2994
2995 rtnl_unlock();
2996
2997 return 0;
2998
2999 err_dev:
3000 rtnl_unlock();
3001 free_netdev(dev);
3002 err:
3003 return err;
3004 }
3005
3006 /*
3007 * Initialize a ppp_file structure.
3008 */
3009 static void
3010 init_ppp_file(struct ppp_file *pf, int kind)
3011 {
3012 pf->kind = kind;
3013 skb_queue_head_init(&pf->xq);
3014 skb_queue_head_init(&pf->rq);
3015 atomic_set(&pf->refcnt, 1);
3016 init_waitqueue_head(&pf->rwait);
3017 }
3018
3019 /*
3020 * Free the memory used by a ppp unit. This is only called once
3021 * there are no channels connected to the unit and no file structs
3022 * that reference the unit.
3023 */
3024 static void ppp_destroy_interface(struct ppp *ppp)
3025 {
3026 atomic_dec(&ppp_unit_count);
3027
3028 if (!ppp->file.dead || ppp->n_channels) {
3029 /* "can't happen" */
3030 netdev_err(ppp->dev, "ppp: destroying ppp struct %p "
3031 "but dead=%d n_channels=%d !\n",
3032 ppp, ppp->file.dead, ppp->n_channels);
3033 return;
3034 }
3035
3036 ppp_ccp_closed(ppp);
3037 if (ppp->vj) {
3038 slhc_free(ppp->vj);
3039 ppp->vj = NULL;
3040 }
3041 skb_queue_purge(&ppp->file.xq);
3042 skb_queue_purge(&ppp->file.rq);
3043 #ifdef CONFIG_PPP_MULTILINK
3044 skb_queue_purge(&ppp->mrq);
3045 #endif /* CONFIG_PPP_MULTILINK */
3046 #ifdef CONFIG_PPP_FILTER
3047 if (ppp->pass_filter) {
3048 bpf_prog_destroy(ppp->pass_filter);
3049 ppp->pass_filter = NULL;
3050 }
3051
3052 if (ppp->active_filter) {
3053 bpf_prog_destroy(ppp->active_filter);
3054 ppp->active_filter = NULL;
3055 }
3056 #endif /* CONFIG_PPP_FILTER */
3057
3058 kfree_skb(ppp->xmit_pending);
3059
3060 free_netdev(ppp->dev);
3061 }
3062
3063 /*
3064 * Locate an existing ppp unit.
3065 * The caller should have locked the all_ppp_mutex.
3066 */
3067 static struct ppp *
3068 ppp_find_unit(struct ppp_net *pn, int unit)
3069 {
3070 return unit_find(&pn->units_idr, unit);
3071 }
3072
3073 /*
3074 * Locate an existing ppp channel.
3075 * The caller should have locked the all_channels_lock.
3076 * First we look in the new_channels list, then in the
3077 * all_channels list. If found in the new_channels list,
3078 * we move it to the all_channels list. This is for speed
3079 * when we have a lot of channels in use.
3080 */
3081 static struct channel *
3082 ppp_find_channel(struct ppp_net *pn, int unit)
3083 {
3084 struct channel *pch;
3085
3086 list_for_each_entry(pch, &pn->new_channels, list) {
3087 if (pch->file.index == unit) {
3088 list_move(&pch->list, &pn->all_channels);
3089 return pch;
3090 }
3091 }
3092
3093 list_for_each_entry(pch, &pn->all_channels, list) {
3094 if (pch->file.index == unit)
3095 return pch;
3096 }
3097
3098 return NULL;
3099 }
3100
3101 /*
3102 * Connect a PPP channel to a PPP interface unit.
3103 */
3104 static int
3105 ppp_connect_channel(struct channel *pch, int unit)
3106 {
3107 struct ppp *ppp;
3108 struct ppp_net *pn;
3109 int ret = -ENXIO;
3110 int hdrlen;
3111
3112 pn = ppp_pernet(pch->chan_net);
3113
3114 mutex_lock(&pn->all_ppp_mutex);
3115 ppp = ppp_find_unit(pn, unit);
3116 if (!ppp)
3117 goto out;
3118 write_lock_bh(&pch->upl);
3119 ret = -EINVAL;
3120 if (pch->ppp)
3121 goto outl;
3122
3123 ppp_lock(ppp);
3124 if (pch->file.hdrlen > ppp->file.hdrlen)
3125 ppp->file.hdrlen = pch->file.hdrlen;
3126 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
3127 if (hdrlen > ppp->dev->hard_header_len)
3128 ppp->dev->hard_header_len = hdrlen;
3129 list_add_tail(&pch->clist, &ppp->channels);
3130 ++ppp->n_channels;
3131 pch->ppp = ppp;
3132 atomic_inc(&ppp->file.refcnt);
3133 ppp_unlock(ppp);
3134 ret = 0;
3135
3136 outl:
3137 write_unlock_bh(&pch->upl);
3138 out:
3139 mutex_unlock(&pn->all_ppp_mutex);
3140 return ret;
3141 }
3142
3143 /*
3144 * Disconnect a channel from its ppp unit.
3145 */
3146 static int
3147 ppp_disconnect_channel(struct channel *pch)
3148 {
3149 struct ppp *ppp;
3150 int err = -EINVAL;
3151
3152 write_lock_bh(&pch->upl);
3153 ppp = pch->ppp;
3154 pch->ppp = NULL;
3155 write_unlock_bh(&pch->upl);
3156 if (ppp) {
3157 /* remove it from the ppp unit's list */
3158 ppp_lock(ppp);
3159 list_del(&pch->clist);
3160 if (--ppp->n_channels == 0)
3161 wake_up_interruptible(&ppp->file.rwait);
3162 ppp_unlock(ppp);
3163 if (atomic_dec_and_test(&ppp->file.refcnt))
3164 ppp_destroy_interface(ppp);
3165 err = 0;
3166 }
3167 return err;
3168 }
3169
3170 /*
3171 * Free up the resources used by a ppp channel.
3172 */
3173 static void ppp_destroy_channel(struct channel *pch)
3174 {
3175 put_net(pch->chan_net);
3176 pch->chan_net = NULL;
3177
3178 atomic_dec(&channel_count);
3179
3180 if (!pch->file.dead) {
3181 /* "can't happen" */
3182 pr_err("ppp: destroying undead channel %p !\n", pch);
3183 return;
3184 }
3185 skb_queue_purge(&pch->file.xq);
3186 skb_queue_purge(&pch->file.rq);
3187 kfree(pch);
3188 }
3189
3190 static void __exit ppp_cleanup(void)
3191 {
3192 /* should never happen */
3193 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
3194 pr_err("PPP: removing module but units remain!\n");
3195 rtnl_link_unregister(&ppp_link_ops);
3196 unregister_chrdev(PPP_MAJOR, "ppp");
3197 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
3198 class_destroy(ppp_class);
3199 unregister_pernet_device(&ppp_net_ops);
3200 }
3201
3202 /*
3203 * Units handling. Caller must protect concurrent access
3204 * by holding all_ppp_mutex
3205 */
3206
3207 /* associate pointer with specified number */
3208 static int unit_set(struct idr *p, void *ptr, int n)
3209 {
3210 int unit;
3211
3212 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL);
3213 if (unit == -ENOSPC)
3214 unit = -EINVAL;
3215 return unit;
3216 }
3217
3218 /* get new free unit number and associate pointer with it */
3219 static int unit_get(struct idr *p, void *ptr)
3220 {
3221 return idr_alloc(p, ptr, 0, 0, GFP_KERNEL);
3222 }
3223
3224 /* put unit number back to a pool */
3225 static void unit_put(struct idr *p, int n)
3226 {
3227 idr_remove(p, n);
3228 }
3229
3230 /* get pointer associated with the number */
3231 static void *unit_find(struct idr *p, int n)
3232 {
3233 return idr_find(p, n);
3234 }
3235
3236 /* Module/initialization stuff */
3237
3238 module_init(ppp_init);
3239 module_exit(ppp_cleanup);
3240
3241 EXPORT_SYMBOL(ppp_register_net_channel);
3242 EXPORT_SYMBOL(ppp_register_channel);
3243 EXPORT_SYMBOL(ppp_unregister_channel);
3244 EXPORT_SYMBOL(ppp_channel_index);
3245 EXPORT_SYMBOL(ppp_unit_number);
3246 EXPORT_SYMBOL(ppp_dev_name);
3247 EXPORT_SYMBOL(ppp_input);
3248 EXPORT_SYMBOL(ppp_input_error);
3249 EXPORT_SYMBOL(ppp_output_wakeup);
3250 EXPORT_SYMBOL(ppp_register_compressor);
3251 EXPORT_SYMBOL(ppp_unregister_compressor);
3252 MODULE_LICENSE("GPL");
3253 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
3254 MODULE_ALIAS_RTNL_LINK("ppp");
3255 MODULE_ALIAS("devname:ppp");
Linux kernel - Deliverables
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