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dmaengine: imx-sdma: Let the core do the device node validation
[linux/fpc-iii.git] / drivers / net / ppp / ppp_generic.c
blobc708400fff4ad71911eeba31b8cbbd4a723ba991
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/sched/signal.h>
28 #include <linux/kmod.h>
29 #include <linux/init.h>
30 #include <linux/list.h>
31 #include <linux/idr.h>
32 #include <linux/netdevice.h>
33 #include <linux/poll.h>
34 #include <linux/ppp_defs.h>
35 #include <linux/filter.h>
36 #include <linux/ppp-ioctl.h>
37 #include <linux/ppp_channel.h>
38 #include <linux/ppp-comp.h>
39 #include <linux/skbuff.h>
40 #include <linux/rtnetlink.h>
41 #include <linux/if_arp.h>
42 #include <linux/ip.h>
43 #include <linux/tcp.h>
44 #include <linux/spinlock.h>
45 #include <linux/rwsem.h>
46 #include <linux/stddef.h>
47 #include <linux/device.h>
48 #include <linux/mutex.h>
49 #include <linux/slab.h>
50 #include <linux/file.h>
51 #include <asm/unaligned.h>
52 #include <net/slhc_vj.h>
53 #include <linux/atomic.h>
54 #include <linux/refcount.h>
55
56 #include <linux/nsproxy.h>
57 #include <net/net_namespace.h>
58 #include <net/netns/generic.h>
59
60 #define PPP_VERSION "2.4.2"
61
62 /*
63 * Network protocols we support.
64 */
65 #define NP_IP 0 /* Internet Protocol V4 */
66 #define NP_IPV6 1 /* Internet Protocol V6 */
67 #define NP_IPX 2 /* IPX protocol */
68 #define NP_AT 3 /* Appletalk protocol */
69 #define NP_MPLS_UC 4 /* MPLS unicast */
70 #define NP_MPLS_MC 5 /* MPLS multicast */
71 #define NUM_NP 6 /* Number of NPs. */
72
73 #define MPHDRLEN 6 /* multilink protocol header length */
74 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */
75
76 /*
77 * An instance of /dev/ppp can be associated with either a ppp
78 * interface unit or a ppp channel. In both cases, file->private_data
79 * points to one of these.
80 */
81 struct ppp_file {
82 enum {
83 INTERFACE=1, CHANNEL
84 } kind;
85 struct sk_buff_head xq; /* pppd transmit queue */
86 struct sk_buff_head rq; /* receive queue for pppd */
87 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */
88 refcount_t refcnt; /* # refs (incl /dev/ppp attached) */
89 int hdrlen; /* space to leave for headers */
90 int index; /* interface unit / channel number */
91 int dead; /* unit/channel has been shut down */
92 };
93
94 #define PF_TO_X(pf, X) container_of(pf, X, file)
95
96 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
97 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
98
99 /*
100 * Data structure to hold primary network stats for which
101 * we want to use 64 bit storage. Other network stats
102 * are stored in dev->stats of the ppp strucute.
103 */
104 struct ppp_link_stats {
105 u64 rx_packets;
106 u64 tx_packets;
107 u64 rx_bytes;
108 u64 tx_bytes;
109 };
110
111 /*
112 * Data structure describing one ppp unit.
113 * A ppp unit corresponds to a ppp network interface device
114 * and represents a multilink bundle.
115 * It can have 0 or more ppp channels connected to it.
116 */
117 struct ppp {
118 struct ppp_file file; /* stuff for read/write/poll 0 */
119 struct file *owner; /* file that owns this unit 48 */
120 struct list_head channels; /* list of attached channels 4c */
121 int n_channels; /* how many channels are attached 54 */
122 spinlock_t rlock; /* lock for receive side 58 */
123 spinlock_t wlock; /* lock for transmit side 5c */
124 int __percpu *xmit_recursion; /* xmit recursion detect */
125 int mru; /* max receive unit 60 */
126 unsigned int flags; /* control bits 64 */
127 unsigned int xstate; /* transmit state bits 68 */
128 unsigned int rstate; /* receive state bits 6c */
129 int debug; /* debug flags 70 */
130 struct slcompress *vj; /* state for VJ header compression */
131 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
132 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
133 struct compressor *xcomp; /* transmit packet compressor 8c */
134 void *xc_state; /* its internal state 90 */
135 struct compressor *rcomp; /* receive decompressor 94 */
136 void *rc_state; /* its internal state 98 */
137 unsigned long last_xmit; /* jiffies when last pkt sent 9c */
138 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
139 struct net_device *dev; /* network interface device a4 */
140 int closing; /* is device closing down? a8 */
141 #ifdef CONFIG_PPP_MULTILINK
142 int nxchan; /* next channel to send something on */
143 u32 nxseq; /* next sequence number to send */
144 int mrru; /* MP: max reconst. receive unit */
145 u32 nextseq; /* MP: seq no of next packet */
146 u32 minseq; /* MP: min of most recent seqnos */
147 struct sk_buff_head mrq; /* MP: receive reconstruction queue */
148 #endif /* CONFIG_PPP_MULTILINK */
149 #ifdef CONFIG_PPP_FILTER
150 struct bpf_prog *pass_filter; /* filter for packets to pass */
151 struct bpf_prog *active_filter; /* filter for pkts to reset idle */
152 #endif /* CONFIG_PPP_FILTER */
153 struct net *ppp_net; /* the net we belong to */
154 struct ppp_link_stats stats64; /* 64 bit network stats */
155 };
156
157 /*
158 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
159 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
160 * SC_MUST_COMP
161 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
162 * Bits in xstate: SC_COMP_RUN
163 */
164 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
165 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
166 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
167
168 /*
169 * Private data structure for each channel.
170 * This includes the data structure used for multilink.
171 */
172 struct channel {
173 struct ppp_file file; /* stuff for read/write/poll */
174 struct list_head list; /* link in all/new_channels list */
175 struct ppp_channel *chan; /* public channel data structure */
176 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
177 spinlock_t downl; /* protects `chan', file.xq dequeue */
178 struct ppp *ppp; /* ppp unit we're connected to */
179 struct net *chan_net; /* the net channel belongs to */
180 struct list_head clist; /* link in list of channels per unit */
181 rwlock_t upl; /* protects `ppp' */
182 #ifdef CONFIG_PPP_MULTILINK
183 u8 avail; /* flag used in multilink stuff */
184 u8 had_frag; /* >= 1 fragments have been sent */
185 u32 lastseq; /* MP: last sequence # received */
186 int speed; /* speed of the corresponding ppp channel*/
187 #endif /* CONFIG_PPP_MULTILINK */
188 };
189
190 struct ppp_config {
191 struct file *file;
192 s32 unit;
193 bool ifname_is_set;
194 };
195
196 /*
197 * SMP locking issues:
198 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
199 * list and the ppp.n_channels field, you need to take both locks
200 * before you modify them.
201 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
202 * channel.downl.
203 */
204
205 static DEFINE_MUTEX(ppp_mutex);
206 static atomic_t ppp_unit_count = ATOMIC_INIT(0);
207 static atomic_t channel_count = ATOMIC_INIT(0);
208
209 /* per-net private data for this module */
210 static unsigned int ppp_net_id __read_mostly;
211 struct ppp_net {
212 /* units to ppp mapping */
213 struct idr units_idr;
214
215 /*
216 * all_ppp_mutex protects the units_idr mapping.
217 * It also ensures that finding a ppp unit in the units_idr
218 * map and updating its file.refcnt field is atomic.
219 */
220 struct mutex all_ppp_mutex;
221
222 /* channels */
223 struct list_head all_channels;
224 struct list_head new_channels;
225 int last_channel_index;
226
227 /*
228 * all_channels_lock protects all_channels and
229 * last_channel_index, and the atomicity of find
230 * a channel and updating its file.refcnt field.
231 */
232 spinlock_t all_channels_lock;
233 };
234
235 /* Get the PPP protocol number from a skb */
236 #define PPP_PROTO(skb) get_unaligned_be16((skb)->data)
237
238 /* We limit the length of ppp->file.rq to this (arbitrary) value */
239 #define PPP_MAX_RQLEN 32
240
241 /*
242 * Maximum number of multilink fragments queued up.
243 * This has to be large enough to cope with the maximum latency of
244 * the slowest channel relative to the others. Strictly it should
245 * depend on the number of channels and their characteristics.
246 */
247 #define PPP_MP_MAX_QLEN 128
248
249 /* Multilink header bits. */
250 #define B 0x80 /* this fragment begins a packet */
251 #define E 0x40 /* this fragment ends a packet */
252
253 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */
254 #define seq_before(a, b) ((s32)((a) - (b)) < 0)
255 #define seq_after(a, b) ((s32)((a) - (b)) > 0)
256
257 /* Prototypes. */
258 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
259 struct file *file, unsigned int cmd, unsigned long arg);
260 static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb);
261 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
262 static void ppp_push(struct ppp *ppp);
263 static void ppp_channel_push(struct channel *pch);
264 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
265 struct channel *pch);
266 static void ppp_receive_error(struct ppp *ppp);
267 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
268 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
269 struct sk_buff *skb);
270 #ifdef CONFIG_PPP_MULTILINK
271 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
272 struct channel *pch);
273 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
274 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
275 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
276 #endif /* CONFIG_PPP_MULTILINK */
277 static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
278 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
279 static void ppp_ccp_closed(struct ppp *ppp);
280 static struct compressor *find_compressor(int type);
281 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
282 static int ppp_create_interface(struct net *net, struct file *file, int *unit);
283 static void init_ppp_file(struct ppp_file *pf, int kind);
284 static void ppp_destroy_interface(struct ppp *ppp);
285 static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit);
286 static struct channel *ppp_find_channel(struct ppp_net *pn, int unit);
287 static int ppp_connect_channel(struct channel *pch, int unit);
288 static int ppp_disconnect_channel(struct channel *pch);
289 static void ppp_destroy_channel(struct channel *pch);
290 static int unit_get(struct idr *p, void *ptr);
291 static int unit_set(struct idr *p, void *ptr, int n);
292 static void unit_put(struct idr *p, int n);
293 static void *unit_find(struct idr *p, int n);
294 static void ppp_setup(struct net_device *dev);
295
296 static const struct net_device_ops ppp_netdev_ops;
297
298 static struct class *ppp_class;
299
300 /* per net-namespace data */
301 static inline struct ppp_net *ppp_pernet(struct net *net)
302 {
303 BUG_ON(!net);
304
305 return net_generic(net, ppp_net_id);
306 }
307
308 /* Translates a PPP protocol number to a NP index (NP == network protocol) */
309 static inline int proto_to_npindex(int proto)
310 {
311 switch (proto) {
312 case PPP_IP:
313 return NP_IP;
314 case PPP_IPV6:
315 return NP_IPV6;
316 case PPP_IPX:
317 return NP_IPX;
318 case PPP_AT:
319 return NP_AT;
320 case PPP_MPLS_UC:
321 return NP_MPLS_UC;
322 case PPP_MPLS_MC:
323 return NP_MPLS_MC;
324 }
325 return -EINVAL;
326 }
327
328 /* Translates an NP index into a PPP protocol number */
329 static const int npindex_to_proto[NUM_NP] = {
330 PPP_IP,
331 PPP_IPV6,
332 PPP_IPX,
333 PPP_AT,
334 PPP_MPLS_UC,
335 PPP_MPLS_MC,
336 };
337
338 /* Translates an ethertype into an NP index */
339 static inline int ethertype_to_npindex(int ethertype)
340 {
341 switch (ethertype) {
342 case ETH_P_IP:
343 return NP_IP;
344 case ETH_P_IPV6:
345 return NP_IPV6;
346 case ETH_P_IPX:
347 return NP_IPX;
348 case ETH_P_PPPTALK:
349 case ETH_P_ATALK:
350 return NP_AT;
351 case ETH_P_MPLS_UC:
352 return NP_MPLS_UC;
353 case ETH_P_MPLS_MC:
354 return NP_MPLS_MC;
355 }
356 return -1;
357 }
358
359 /* Translates an NP index into an ethertype */
360 static const int npindex_to_ethertype[NUM_NP] = {
361 ETH_P_IP,
362 ETH_P_IPV6,
363 ETH_P_IPX,
364 ETH_P_PPPTALK,
365 ETH_P_MPLS_UC,
366 ETH_P_MPLS_MC,
367 };
368
369 /*
370 * Locking shorthand.
371 */
372 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
373 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
374 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
375 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
376 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
377 ppp_recv_lock(ppp); } while (0)
378 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
379 ppp_xmit_unlock(ppp); } while (0)
380
381 /*
382 * /dev/ppp device routines.
383 * The /dev/ppp device is used by pppd to control the ppp unit.
384 * It supports the read, write, ioctl and poll functions.
385 * Open instances of /dev/ppp can be in one of three states:
386 * unattached, attached to a ppp unit, or attached to a ppp channel.
387 */
388 static int ppp_open(struct inode *inode, struct file *file)
389 {
390 /*
391 * This could (should?) be enforced by the permissions on /dev/ppp.
392 */
393 if (!ns_capable(file->f_cred->user_ns, CAP_NET_ADMIN))
394 return -EPERM;
395 return 0;
396 }
397
398 static int ppp_release(struct inode *unused, struct file *file)
399 {
400 struct ppp_file *pf = file->private_data;
401 struct ppp *ppp;
402
403 if (pf) {
404 file->private_data = NULL;
405 if (pf->kind == INTERFACE) {
406 ppp = PF_TO_PPP(pf);
407 rtnl_lock();
408 if (file == ppp->owner)
409 unregister_netdevice(ppp->dev);
410 rtnl_unlock();
411 }
412 if (refcount_dec_and_test(&pf->refcnt)) {
413 switch (pf->kind) {
414 case INTERFACE:
415 ppp_destroy_interface(PF_TO_PPP(pf));
416 break;
417 case CHANNEL:
418 ppp_destroy_channel(PF_TO_CHANNEL(pf));
419 break;
420 }
421 }
422 }
423 return 0;
424 }
425
426 static ssize_t ppp_read(struct file *file, char __user *buf,
427 size_t count, loff_t *ppos)
428 {
429 struct ppp_file *pf = file->private_data;
430 DECLARE_WAITQUEUE(wait, current);
431 ssize_t ret;
432 struct sk_buff *skb = NULL;
433 struct iovec iov;
434 struct iov_iter to;
435
436 ret = count;
437
438 if (!pf)
439 return -ENXIO;
440 add_wait_queue(&pf->rwait, &wait);
441 for (;;) {
442 set_current_state(TASK_INTERRUPTIBLE);
443 skb = skb_dequeue(&pf->rq);
444 if (skb)
445 break;
446 ret = 0;
447 if (pf->dead)
448 break;
449 if (pf->kind == INTERFACE) {
450 /*
451 * Return 0 (EOF) on an interface that has no
452 * channels connected, unless it is looping
453 * network traffic (demand mode).
454 */
455 struct ppp *ppp = PF_TO_PPP(pf);
456
457 ppp_recv_lock(ppp);
458 if (ppp->n_channels == 0 &&
459 (ppp->flags & SC_LOOP_TRAFFIC) == 0) {
460 ppp_recv_unlock(ppp);
461 break;
462 }
463 ppp_recv_unlock(ppp);
464 }
465 ret = -EAGAIN;
466 if (file->f_flags & O_NONBLOCK)
467 break;
468 ret = -ERESTARTSYS;
469 if (signal_pending(current))
470 break;
471 schedule();
472 }
473 set_current_state(TASK_RUNNING);
474 remove_wait_queue(&pf->rwait, &wait);
475
476 if (!skb)
477 goto out;
478
479 ret = -EOVERFLOW;
480 if (skb->len > count)
481 goto outf;
482 ret = -EFAULT;
483 iov.iov_base = buf;
484 iov.iov_len = count;
485 iov_iter_init(&to, READ, &iov, 1, count);
486 if (skb_copy_datagram_iter(skb, 0, &to, skb->len))
487 goto outf;
488 ret = skb->len;
489
490 outf:
491 kfree_skb(skb);
492 out:
493 return ret;
494 }
495
496 static ssize_t ppp_write(struct file *file, const char __user *buf,
497 size_t count, loff_t *ppos)
498 {
499 struct ppp_file *pf = file->private_data;
500 struct sk_buff *skb;
501 ssize_t ret;
502
503 if (!pf)
504 return -ENXIO;
505 ret = -ENOMEM;
506 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
507 if (!skb)
508 goto out;
509 skb_reserve(skb, pf->hdrlen);
510 ret = -EFAULT;
511 if (copy_from_user(skb_put(skb, count), buf, count)) {
512 kfree_skb(skb);
513 goto out;
514 }
515
516 switch (pf->kind) {
517 case INTERFACE:
518 ppp_xmit_process(PF_TO_PPP(pf), skb);
519 break;
520 case CHANNEL:
521 skb_queue_tail(&pf->xq, skb);
522 ppp_channel_push(PF_TO_CHANNEL(pf));
523 break;
524 }
525
526 ret = count;
527
528 out:
529 return ret;
530 }
531
532 /* No kernel lock - fine */
533 static __poll_t ppp_poll(struct file *file, poll_table *wait)
534 {
535 struct ppp_file *pf = file->private_data;
536 __poll_t mask;
537
538 if (!pf)
539 return 0;
540 poll_wait(file, &pf->rwait, wait);
541 mask = EPOLLOUT | EPOLLWRNORM;
542 if (skb_peek(&pf->rq))
543 mask |= EPOLLIN | EPOLLRDNORM;
544 if (pf->dead)
545 mask |= EPOLLHUP;
546 else if (pf->kind == INTERFACE) {
547 /* see comment in ppp_read */
548 struct ppp *ppp = PF_TO_PPP(pf);
549
550 ppp_recv_lock(ppp);
551 if (ppp->n_channels == 0 &&
552 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
553 mask |= EPOLLIN | EPOLLRDNORM;
554 ppp_recv_unlock(ppp);
555 }
556
557 return mask;
558 }
559
560 #ifdef CONFIG_PPP_FILTER
561 static int get_filter(void __user *arg, struct sock_filter **p)
562 {
563 struct sock_fprog uprog;
564 struct sock_filter *code = NULL;
565 int len;
566
567 if (copy_from_user(&uprog, arg, sizeof(uprog)))
568 return -EFAULT;
569
570 if (!uprog.len) {
571 *p = NULL;
572 return 0;
573 }
574
575 len = uprog.len * sizeof(struct sock_filter);
576 code = memdup_user(uprog.filter, len);
577 if (IS_ERR(code))
578 return PTR_ERR(code);
579
580 *p = code;
581 return uprog.len;
582 }
583 #endif /* CONFIG_PPP_FILTER */
584
585 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
586 {
587 struct ppp_file *pf;
588 struct ppp *ppp;
589 int err = -EFAULT, val, val2, i;
590 struct ppp_idle idle;
591 struct npioctl npi;
592 int unit, cflags;
593 struct slcompress *vj;
594 void __user *argp = (void __user *)arg;
595 int __user *p = argp;
596
597 mutex_lock(&ppp_mutex);
598
599 pf = file->private_data;
600 if (!pf) {
601 err = ppp_unattached_ioctl(current->nsproxy->net_ns,
602 pf, file, cmd, arg);
603 goto out;
604 }
605
606 if (cmd == PPPIOCDETACH) {
607 /*
608 * PPPIOCDETACH is no longer supported as it was heavily broken,
609 * and is only known to have been used by pppd older than
610 * ppp-2.4.2 (released November 2003).
611 */
612 pr_warn_once("%s (%d) used obsolete PPPIOCDETACH ioctl\n",
613 current->comm, current->pid);
614 err = -EINVAL;
615 goto out;
616 }
617
618 if (pf->kind == CHANNEL) {
619 struct channel *pch;
620 struct ppp_channel *chan;
621
622 pch = PF_TO_CHANNEL(pf);
623
624 switch (cmd) {
625 case PPPIOCCONNECT:
626 if (get_user(unit, p))
627 break;
628 err = ppp_connect_channel(pch, unit);
629 break;
630
631 case PPPIOCDISCONN:
632 err = ppp_disconnect_channel(pch);
633 break;
634
635 default:
636 down_read(&pch->chan_sem);
637 chan = pch->chan;
638 err = -ENOTTY;
639 if (chan && chan->ops->ioctl)
640 err = chan->ops->ioctl(chan, cmd, arg);
641 up_read(&pch->chan_sem);
642 }
643 goto out;
644 }
645
646 if (pf->kind != INTERFACE) {
647 /* can't happen */
648 pr_err("PPP: not interface or channel??\n");
649 err = -EINVAL;
650 goto out;
651 }
652
653 ppp = PF_TO_PPP(pf);
654 switch (cmd) {
655 case PPPIOCSMRU:
656 if (get_user(val, p))
657 break;
658 ppp->mru = val;
659 err = 0;
660 break;
661
662 case PPPIOCSFLAGS:
663 if (get_user(val, p))
664 break;
665 ppp_lock(ppp);
666 cflags = ppp->flags & ~val;
667 #ifdef CONFIG_PPP_MULTILINK
668 if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK))
669 ppp->nextseq = 0;
670 #endif
671 ppp->flags = val & SC_FLAG_BITS;
672 ppp_unlock(ppp);
673 if (cflags & SC_CCP_OPEN)
674 ppp_ccp_closed(ppp);
675 err = 0;
676 break;
677
678 case PPPIOCGFLAGS:
679 val = ppp->flags | ppp->xstate | ppp->rstate;
680 if (put_user(val, p))
681 break;
682 err = 0;
683 break;
684
685 case PPPIOCSCOMPRESS:
686 err = ppp_set_compress(ppp, arg);
687 break;
688
689 case PPPIOCGUNIT:
690 if (put_user(ppp->file.index, p))
691 break;
692 err = 0;
693 break;
694
695 case PPPIOCSDEBUG:
696 if (get_user(val, p))
697 break;
698 ppp->debug = val;
699 err = 0;
700 break;
701
702 case PPPIOCGDEBUG:
703 if (put_user(ppp->debug, p))
704 break;
705 err = 0;
706 break;
707
708 case PPPIOCGIDLE:
709 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
710 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
711 if (copy_to_user(argp, &idle, sizeof(idle)))
712 break;
713 err = 0;
714 break;
715
716 case PPPIOCSMAXCID:
717 if (get_user(val, p))
718 break;
719 val2 = 15;
720 if ((val >> 16) != 0) {
721 val2 = val >> 16;
722 val &= 0xffff;
723 }
724 vj = slhc_init(val2+1, val+1);
725 if (IS_ERR(vj)) {
726 err = PTR_ERR(vj);
727 break;
728 }
729 ppp_lock(ppp);
730 if (ppp->vj)
731 slhc_free(ppp->vj);
732 ppp->vj = vj;
733 ppp_unlock(ppp);
734 err = 0;
735 break;
736
737 case PPPIOCGNPMODE:
738 case PPPIOCSNPMODE:
739 if (copy_from_user(&npi, argp, sizeof(npi)))
740 break;
741 err = proto_to_npindex(npi.protocol);
742 if (err < 0)
743 break;
744 i = err;
745 if (cmd == PPPIOCGNPMODE) {
746 err = -EFAULT;
747 npi.mode = ppp->npmode[i];
748 if (copy_to_user(argp, &npi, sizeof(npi)))
749 break;
750 } else {
751 ppp->npmode[i] = npi.mode;
752 /* we may be able to transmit more packets now (??) */
753 netif_wake_queue(ppp->dev);
754 }
755 err = 0;
756 break;
757
758 #ifdef CONFIG_PPP_FILTER
759 case PPPIOCSPASS:
760 {
761 struct sock_filter *code;
762
763 err = get_filter(argp, &code);
764 if (err >= 0) {
765 struct bpf_prog *pass_filter = NULL;
766 struct sock_fprog_kern fprog = {
767 .len = err,
768 .filter = code,
769 };
770
771 err = 0;
772 if (fprog.filter)
773 err = bpf_prog_create(&pass_filter, &fprog);
774 if (!err) {
775 ppp_lock(ppp);
776 if (ppp->pass_filter)
777 bpf_prog_destroy(ppp->pass_filter);
778 ppp->pass_filter = pass_filter;
779 ppp_unlock(ppp);
780 }
781 kfree(code);
782 }
783 break;
784 }
785 case PPPIOCSACTIVE:
786 {
787 struct sock_filter *code;
788
789 err = get_filter(argp, &code);
790 if (err >= 0) {
791 struct bpf_prog *active_filter = NULL;
792 struct sock_fprog_kern fprog = {
793 .len = err,
794 .filter = code,
795 };
796
797 err = 0;
798 if (fprog.filter)
799 err = bpf_prog_create(&active_filter, &fprog);
800 if (!err) {
801 ppp_lock(ppp);
802 if (ppp->active_filter)
803 bpf_prog_destroy(ppp->active_filter);
804 ppp->active_filter = active_filter;
805 ppp_unlock(ppp);
806 }
807 kfree(code);
808 }
809 break;
810 }
811 #endif /* CONFIG_PPP_FILTER */
812
813 #ifdef CONFIG_PPP_MULTILINK
814 case PPPIOCSMRRU:
815 if (get_user(val, p))
816 break;
817 ppp_recv_lock(ppp);
818 ppp->mrru = val;
819 ppp_recv_unlock(ppp);
820 err = 0;
821 break;
822 #endif /* CONFIG_PPP_MULTILINK */
823
824 default:
825 err = -ENOTTY;
826 }
827
828 out:
829 mutex_unlock(&ppp_mutex);
830
831 return err;
832 }
833
834 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
835 struct file *file, unsigned int cmd, unsigned long arg)
836 {
837 int unit, err = -EFAULT;
838 struct ppp *ppp;
839 struct channel *chan;
840 struct ppp_net *pn;
841 int __user *p = (int __user *)arg;
842
843 switch (cmd) {
844 case PPPIOCNEWUNIT:
845 /* Create a new ppp unit */
846 if (get_user(unit, p))
847 break;
848 err = ppp_create_interface(net, file, &unit);
849 if (err < 0)
850 break;
851
852 err = -EFAULT;
853 if (put_user(unit, p))
854 break;
855 err = 0;
856 break;
857
858 case PPPIOCATTACH:
859 /* Attach to an existing ppp unit */
860 if (get_user(unit, p))
861 break;
862 err = -ENXIO;
863 pn = ppp_pernet(net);
864 mutex_lock(&pn->all_ppp_mutex);
865 ppp = ppp_find_unit(pn, unit);
866 if (ppp) {
867 refcount_inc(&ppp->file.refcnt);
868 file->private_data = &ppp->file;
869 err = 0;
870 }
871 mutex_unlock(&pn->all_ppp_mutex);
872 break;
873
874 case PPPIOCATTCHAN:
875 if (get_user(unit, p))
876 break;
877 err = -ENXIO;
878 pn = ppp_pernet(net);
879 spin_lock_bh(&pn->all_channels_lock);
880 chan = ppp_find_channel(pn, unit);
881 if (chan) {
882 refcount_inc(&chan->file.refcnt);
883 file->private_data = &chan->file;
884 err = 0;
885 }
886 spin_unlock_bh(&pn->all_channels_lock);
887 break;
888
889 default:
890 err = -ENOTTY;
891 }
892
893 return err;
894 }
895
896 static const struct file_operations ppp_device_fops = {
897 .owner = THIS_MODULE,
898 .read = ppp_read,
899 .write = ppp_write,
900 .poll = ppp_poll,
901 .unlocked_ioctl = ppp_ioctl,
902 .open = ppp_open,
903 .release = ppp_release,
904 .llseek = noop_llseek,
905 };
906
907 static __net_init int ppp_init_net(struct net *net)
908 {
909 struct ppp_net *pn = net_generic(net, ppp_net_id);
910
911 idr_init(&pn->units_idr);
912 mutex_init(&pn->all_ppp_mutex);
913
914 INIT_LIST_HEAD(&pn->all_channels);
915 INIT_LIST_HEAD(&pn->new_channels);
916
917 spin_lock_init(&pn->all_channels_lock);
918
919 return 0;
920 }
921
922 static __net_exit void ppp_exit_net(struct net *net)
923 {
924 struct ppp_net *pn = net_generic(net, ppp_net_id);
925 struct net_device *dev;
926 struct net_device *aux;
927 struct ppp *ppp;
928 LIST_HEAD(list);
929 int id;
930
931 rtnl_lock();
932 for_each_netdev_safe(net, dev, aux) {
933 if (dev->netdev_ops == &ppp_netdev_ops)
934 unregister_netdevice_queue(dev, &list);
935 }
936
937 idr_for_each_entry(&pn->units_idr, ppp, id)
938 /* Skip devices already unregistered by previous loop */
939 if (!net_eq(dev_net(ppp->dev), net))
940 unregister_netdevice_queue(ppp->dev, &list);
941
942 unregister_netdevice_many(&list);
943 rtnl_unlock();
944
945 mutex_destroy(&pn->all_ppp_mutex);
946 idr_destroy(&pn->units_idr);
947 WARN_ON_ONCE(!list_empty(&pn->all_channels));
948 WARN_ON_ONCE(!list_empty(&pn->new_channels));
949 }
950
951 static struct pernet_operations ppp_net_ops = {
952 .init = ppp_init_net,
953 .exit = ppp_exit_net,
954 .id = &ppp_net_id,
955 .size = sizeof(struct ppp_net),
956 };
957
958 static int ppp_unit_register(struct ppp *ppp, int unit, bool ifname_is_set)
959 {
960 struct ppp_net *pn = ppp_pernet(ppp->ppp_net);
961 int ret;
962
963 mutex_lock(&pn->all_ppp_mutex);
964
965 if (unit < 0) {
966 ret = unit_get(&pn->units_idr, ppp);
967 if (ret < 0)
968 goto err;
969 } else {
970 /* Caller asked for a specific unit number. Fail with -EEXIST
971 * if unavailable. For backward compatibility, return -EEXIST
972 * too if idr allocation fails; this makes pppd retry without
973 * requesting a specific unit number.
974 */
975 if (unit_find(&pn->units_idr, unit)) {
976 ret = -EEXIST;
977 goto err;
978 }
979 ret = unit_set(&pn->units_idr, ppp, unit);
980 if (ret < 0) {
981 /* Rewrite error for backward compatibility */
982 ret = -EEXIST;
983 goto err;
984 }
985 }
986 ppp->file.index = ret;
987
988 if (!ifname_is_set)
989 snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ppp->file.index);
990
991 mutex_unlock(&pn->all_ppp_mutex);
992
993 ret = register_netdevice(ppp->dev);
994 if (ret < 0)
995 goto err_unit;
996
997 atomic_inc(&ppp_unit_count);
998
999 return 0;
1000
1001 err_unit:
1002 mutex_lock(&pn->all_ppp_mutex);
1003 unit_put(&pn->units_idr, ppp->file.index);
1004 err:
1005 mutex_unlock(&pn->all_ppp_mutex);
1006
1007 return ret;
1008 }
1009
1010 static int ppp_dev_configure(struct net *src_net, struct net_device *dev,
1011 const struct ppp_config *conf)
1012 {
1013 struct ppp *ppp = netdev_priv(dev);
1014 int indx;
1015 int err;
1016 int cpu;
1017
1018 ppp->dev = dev;
1019 ppp->ppp_net = src_net;
1020 ppp->mru = PPP_MRU;
1021 ppp->owner = conf->file;
1022
1023 init_ppp_file(&ppp->file, INTERFACE);
1024 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
1025
1026 for (indx = 0; indx < NUM_NP; ++indx)
1027 ppp->npmode[indx] = NPMODE_PASS;
1028 INIT_LIST_HEAD(&ppp->channels);
1029 spin_lock_init(&ppp->rlock);
1030 spin_lock_init(&ppp->wlock);
1031
1032 ppp->xmit_recursion = alloc_percpu(int);
1033 if (!ppp->xmit_recursion) {
1034 err = -ENOMEM;
1035 goto err1;
1036 }
1037 for_each_possible_cpu(cpu)
1038 (*per_cpu_ptr(ppp->xmit_recursion, cpu)) = 0;
1039
1040 #ifdef CONFIG_PPP_MULTILINK
1041 ppp->minseq = -1;
1042 skb_queue_head_init(&ppp->mrq);
1043 #endif /* CONFIG_PPP_MULTILINK */
1044 #ifdef CONFIG_PPP_FILTER
1045 ppp->pass_filter = NULL;
1046 ppp->active_filter = NULL;
1047 #endif /* CONFIG_PPP_FILTER */
1048
1049 err = ppp_unit_register(ppp, conf->unit, conf->ifname_is_set);
1050 if (err < 0)
1051 goto err2;
1052
1053 conf->file->private_data = &ppp->file;
1054
1055 return 0;
1056 err2:
1057 free_percpu(ppp->xmit_recursion);
1058 err1:
1059 return err;
1060 }
1061
1062 static const struct nla_policy ppp_nl_policy[IFLA_PPP_MAX + 1] = {
1063 [IFLA_PPP_DEV_FD] = { .type = NLA_S32 },
1064 };
1065
1066 static int ppp_nl_validate(struct nlattr *tb[], struct nlattr *data[],
1067 struct netlink_ext_ack *extack)
1068 {
1069 if (!data)
1070 return -EINVAL;
1071
1072 if (!data[IFLA_PPP_DEV_FD])
1073 return -EINVAL;
1074 if (nla_get_s32(data[IFLA_PPP_DEV_FD]) < 0)
1075 return -EBADF;
1076
1077 return 0;
1078 }
1079
1080 static int ppp_nl_newlink(struct net *src_net, struct net_device *dev,
1081 struct nlattr *tb[], struct nlattr *data[],
1082 struct netlink_ext_ack *extack)
1083 {
1084 struct ppp_config conf = {
1085 .unit = -1,
1086 .ifname_is_set = true,
1087 };
1088 struct file *file;
1089 int err;
1090
1091 file = fget(nla_get_s32(data[IFLA_PPP_DEV_FD]));
1092 if (!file)
1093 return -EBADF;
1094
1095 /* rtnl_lock is already held here, but ppp_create_interface() locks
1096 * ppp_mutex before holding rtnl_lock. Using mutex_trylock() avoids
1097 * possible deadlock due to lock order inversion, at the cost of
1098 * pushing the problem back to userspace.
1099 */
1100 if (!mutex_trylock(&ppp_mutex)) {
1101 err = -EBUSY;
1102 goto out;
1103 }
1104
1105 if (file->f_op != &ppp_device_fops || file->private_data) {
1106 err = -EBADF;
1107 goto out_unlock;
1108 }
1109
1110 conf.file = file;
1111
1112 /* Don't use device name generated by the rtnetlink layer when ifname
1113 * isn't specified. Let ppp_dev_configure() set the device name using
1114 * the PPP unit identifer as suffix (i.e. ppp<unit_id>). This allows
1115 * userspace to infer the device name using to the PPPIOCGUNIT ioctl.
1116 */
1117 if (!tb[IFLA_IFNAME])
1118 conf.ifname_is_set = false;
1119
1120 err = ppp_dev_configure(src_net, dev, &conf);
1121
1122 out_unlock:
1123 mutex_unlock(&ppp_mutex);
1124 out:
1125 fput(file);
1126
1127 return err;
1128 }
1129
1130 static void ppp_nl_dellink(struct net_device *dev, struct list_head *head)
1131 {
1132 unregister_netdevice_queue(dev, head);
1133 }
1134
1135 static size_t ppp_nl_get_size(const struct net_device *dev)
1136 {
1137 return 0;
1138 }
1139
1140 static int ppp_nl_fill_info(struct sk_buff *skb, const struct net_device *dev)
1141 {
1142 return 0;
1143 }
1144
1145 static struct net *ppp_nl_get_link_net(const struct net_device *dev)
1146 {
1147 struct ppp *ppp = netdev_priv(dev);
1148
1149 return ppp->ppp_net;
1150 }
1151
1152 static struct rtnl_link_ops ppp_link_ops __read_mostly = {
1153 .kind = "ppp",
1154 .maxtype = IFLA_PPP_MAX,
1155 .policy = ppp_nl_policy,
1156 .priv_size = sizeof(struct ppp),
1157 .setup = ppp_setup,
1158 .validate = ppp_nl_validate,
1159 .newlink = ppp_nl_newlink,
1160 .dellink = ppp_nl_dellink,
1161 .get_size = ppp_nl_get_size,
1162 .fill_info = ppp_nl_fill_info,
1163 .get_link_net = ppp_nl_get_link_net,
1164 };
1165
1166 #define PPP_MAJOR 108
1167
1168 /* Called at boot time if ppp is compiled into the kernel,
1169 or at module load time (from init_module) if compiled as a module. */
1170 static int __init ppp_init(void)
1171 {
1172 int err;
1173
1174 pr_info("PPP generic driver version " PPP_VERSION "\n");
1175
1176 err = register_pernet_device(&ppp_net_ops);
1177 if (err) {
1178 pr_err("failed to register PPP pernet device (%d)\n", err);
1179 goto out;
1180 }
1181
1182 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
1183 if (err) {
1184 pr_err("failed to register PPP device (%d)\n", err);
1185 goto out_net;
1186 }
1187
1188 ppp_class = class_create(THIS_MODULE, "ppp");
1189 if (IS_ERR(ppp_class)) {
1190 err = PTR_ERR(ppp_class);
1191 goto out_chrdev;
1192 }
1193
1194 err = rtnl_link_register(&ppp_link_ops);
1195 if (err) {
1196 pr_err("failed to register rtnetlink PPP handler\n");
1197 goto out_class;
1198 }
1199
1200 /* not a big deal if we fail here :-) */
1201 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
1202
1203 return 0;
1204
1205 out_class:
1206 class_destroy(ppp_class);
1207 out_chrdev:
1208 unregister_chrdev(PPP_MAJOR, "ppp");
1209 out_net:
1210 unregister_pernet_device(&ppp_net_ops);
1211 out:
1212 return err;
1213 }
1214
1215 /*
1216 * Network interface unit routines.
1217 */
1218 static netdev_tx_t
1219 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
1220 {
1221 struct ppp *ppp = netdev_priv(dev);
1222 int npi, proto;
1223 unsigned char *pp;
1224
1225 npi = ethertype_to_npindex(ntohs(skb->protocol));
1226 if (npi < 0)
1227 goto outf;
1228
1229 /* Drop, accept or reject the packet */
1230 switch (ppp->npmode[npi]) {
1231 case NPMODE_PASS:
1232 break;
1233 case NPMODE_QUEUE:
1234 /* it would be nice to have a way to tell the network
1235 system to queue this one up for later. */
1236 goto outf;
1237 case NPMODE_DROP:
1238 case NPMODE_ERROR:
1239 goto outf;
1240 }
1241
1242 /* Put the 2-byte PPP protocol number on the front,
1243 making sure there is room for the address and control fields. */
1244 if (skb_cow_head(skb, PPP_HDRLEN))
1245 goto outf;
1246
1247 pp = skb_push(skb, 2);
1248 proto = npindex_to_proto[npi];
1249 put_unaligned_be16(proto, pp);
1250
1251 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, dev_net(dev)));
1252 ppp_xmit_process(ppp, skb);
1253
1254 return NETDEV_TX_OK;
1255
1256 outf:
1257 kfree_skb(skb);
1258 ++dev->stats.tx_dropped;
1259 return NETDEV_TX_OK;
1260 }
1261
1262 static int
1263 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1264 {
1265 struct ppp *ppp = netdev_priv(dev);
1266 int err = -EFAULT;
1267 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
1268 struct ppp_stats stats;
1269 struct ppp_comp_stats cstats;
1270 char *vers;
1271
1272 switch (cmd) {
1273 case SIOCGPPPSTATS:
1274 ppp_get_stats(ppp, &stats);
1275 if (copy_to_user(addr, &stats, sizeof(stats)))
1276 break;
1277 err = 0;
1278 break;
1279
1280 case SIOCGPPPCSTATS:
1281 memset(&cstats, 0, sizeof(cstats));
1282 if (ppp->xc_state)
1283 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
1284 if (ppp->rc_state)
1285 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
1286 if (copy_to_user(addr, &cstats, sizeof(cstats)))
1287 break;
1288 err = 0;
1289 break;
1290
1291 case SIOCGPPPVER:
1292 vers = PPP_VERSION;
1293 if (copy_to_user(addr, vers, strlen(vers) + 1))
1294 break;
1295 err = 0;
1296 break;
1297
1298 default:
1299 err = -EINVAL;
1300 }
1301
1302 return err;
1303 }
1304
1305 static void
1306 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64)
1307 {
1308 struct ppp *ppp = netdev_priv(dev);
1309
1310 ppp_recv_lock(ppp);
1311 stats64->rx_packets = ppp->stats64.rx_packets;
1312 stats64->rx_bytes = ppp->stats64.rx_bytes;
1313 ppp_recv_unlock(ppp);
1314
1315 ppp_xmit_lock(ppp);
1316 stats64->tx_packets = ppp->stats64.tx_packets;
1317 stats64->tx_bytes = ppp->stats64.tx_bytes;
1318 ppp_xmit_unlock(ppp);
1319
1320 stats64->rx_errors = dev->stats.rx_errors;
1321 stats64->tx_errors = dev->stats.tx_errors;
1322 stats64->rx_dropped = dev->stats.rx_dropped;
1323 stats64->tx_dropped = dev->stats.tx_dropped;
1324 stats64->rx_length_errors = dev->stats.rx_length_errors;
1325 }
1326
1327 static int ppp_dev_init(struct net_device *dev)
1328 {
1329 struct ppp *ppp;
1330
1331 netdev_lockdep_set_classes(dev);
1332
1333 ppp = netdev_priv(dev);
1334 /* Let the netdevice take a reference on the ppp file. This ensures
1335 * that ppp_destroy_interface() won't run before the device gets
1336 * unregistered.
1337 */
1338 refcount_inc(&ppp->file.refcnt);
1339
1340 return 0;
1341 }
1342
1343 static void ppp_dev_uninit(struct net_device *dev)
1344 {
1345 struct ppp *ppp = netdev_priv(dev);
1346 struct ppp_net *pn = ppp_pernet(ppp->ppp_net);
1347
1348 ppp_lock(ppp);
1349 ppp->closing = 1;
1350 ppp_unlock(ppp);
1351
1352 mutex_lock(&pn->all_ppp_mutex);
1353 unit_put(&pn->units_idr, ppp->file.index);
1354 mutex_unlock(&pn->all_ppp_mutex);
1355
1356 ppp->owner = NULL;
1357
1358 ppp->file.dead = 1;
1359 wake_up_interruptible(&ppp->file.rwait);
1360 }
1361
1362 static void ppp_dev_priv_destructor(struct net_device *dev)
1363 {
1364 struct ppp *ppp;
1365
1366 ppp = netdev_priv(dev);
1367 if (refcount_dec_and_test(&ppp->file.refcnt))
1368 ppp_destroy_interface(ppp);
1369 }
1370
1371 static const struct net_device_ops ppp_netdev_ops = {
1372 .ndo_init = ppp_dev_init,
1373 .ndo_uninit = ppp_dev_uninit,
1374 .ndo_start_xmit = ppp_start_xmit,
1375 .ndo_do_ioctl = ppp_net_ioctl,
1376 .ndo_get_stats64 = ppp_get_stats64,
1377 };
1378
1379 static struct device_type ppp_type = {
1380 .name = "ppp",
1381 };
1382
1383 static void ppp_setup(struct net_device *dev)
1384 {
1385 dev->netdev_ops = &ppp_netdev_ops;
1386 SET_NETDEV_DEVTYPE(dev, &ppp_type);
1387
1388 dev->features |= NETIF_F_LLTX;
1389
1390 dev->hard_header_len = PPP_HDRLEN;
1391 dev->mtu = PPP_MRU;
1392 dev->addr_len = 0;
1393 dev->tx_queue_len = 3;
1394 dev->type = ARPHRD_PPP;
1395 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1396 dev->priv_destructor = ppp_dev_priv_destructor;
1397 netif_keep_dst(dev);
1398 }
1399
1400 /*
1401 * Transmit-side routines.
1402 */
1403
1404 /* Called to do any work queued up on the transmit side that can now be done */
1405 static void __ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb)
1406 {
1407 ppp_xmit_lock(ppp);
1408 if (!ppp->closing) {
1409 ppp_push(ppp);
1410
1411 if (skb)
1412 skb_queue_tail(&ppp->file.xq, skb);
1413 while (!ppp->xmit_pending &&
1414 (skb = skb_dequeue(&ppp->file.xq)))
1415 ppp_send_frame(ppp, skb);
1416 /* If there's no work left to do, tell the core net
1417 code that we can accept some more. */
1418 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1419 netif_wake_queue(ppp->dev);
1420 else
1421 netif_stop_queue(ppp->dev);
1422 }
1423 ppp_xmit_unlock(ppp);
1424 }
1425
1426 static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb)
1427 {
1428 local_bh_disable();
1429
1430 if (unlikely(*this_cpu_ptr(ppp->xmit_recursion)))
1431 goto err;
1432
1433 (*this_cpu_ptr(ppp->xmit_recursion))++;
1434 __ppp_xmit_process(ppp, skb);
1435 (*this_cpu_ptr(ppp->xmit_recursion))--;
1436
1437 local_bh_enable();
1438
1439 return;
1440
1441 err:
1442 local_bh_enable();
1443
1444 kfree_skb(skb);
1445
1446 if (net_ratelimit())
1447 netdev_err(ppp->dev, "recursion detected\n");
1448 }
1449
1450 static inline struct sk_buff *
1451 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1452 {
1453 struct sk_buff *new_skb;
1454 int len;
1455 int new_skb_size = ppp->dev->mtu +
1456 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1457 int compressor_skb_size = ppp->dev->mtu +
1458 ppp->xcomp->comp_extra + PPP_HDRLEN;
1459 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1460 if (!new_skb) {
1461 if (net_ratelimit())
1462 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n");
1463 return NULL;
1464 }
1465 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1466 skb_reserve(new_skb,
1467 ppp->dev->hard_header_len - PPP_HDRLEN);
1468
1469 /* compressor still expects A/C bytes in hdr */
1470 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1471 new_skb->data, skb->len + 2,
1472 compressor_skb_size);
1473 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1474 consume_skb(skb);
1475 skb = new_skb;
1476 skb_put(skb, len);
1477 skb_pull(skb, 2); /* pull off A/C bytes */
1478 } else if (len == 0) {
1479 /* didn't compress, or CCP not up yet */
1480 consume_skb(new_skb);
1481 new_skb = skb;
1482 } else {
1483 /*
1484 * (len < 0)
1485 * MPPE requires that we do not send unencrypted
1486 * frames. The compressor will return -1 if we
1487 * should drop the frame. We cannot simply test
1488 * the compress_proto because MPPE and MPPC share
1489 * the same number.
1490 */
1491 if (net_ratelimit())
1492 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n");
1493 kfree_skb(skb);
1494 consume_skb(new_skb);
1495 new_skb = NULL;
1496 }
1497 return new_skb;
1498 }
1499
1500 /*
1501 * Compress and send a frame.
1502 * The caller should have locked the xmit path,
1503 * and xmit_pending should be 0.
1504 */
1505 static void
1506 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1507 {
1508 int proto = PPP_PROTO(skb);
1509 struct sk_buff *new_skb;
1510 int len;
1511 unsigned char *cp;
1512
1513 if (proto < 0x8000) {
1514 #ifdef CONFIG_PPP_FILTER
1515 /* check if we should pass this packet */
1516 /* the filter instructions are constructed assuming
1517 a four-byte PPP header on each packet */
1518 *(u8 *)skb_push(skb, 2) = 1;
1519 if (ppp->pass_filter &&
1520 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
1521 if (ppp->debug & 1)
1522 netdev_printk(KERN_DEBUG, ppp->dev,
1523 "PPP: outbound frame "
1524 "not passed\n");
1525 kfree_skb(skb);
1526 return;
1527 }
1528 /* if this packet passes the active filter, record the time */
1529 if (!(ppp->active_filter &&
1530 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
1531 ppp->last_xmit = jiffies;
1532 skb_pull(skb, 2);
1533 #else
1534 /* for data packets, record the time */
1535 ppp->last_xmit = jiffies;
1536 #endif /* CONFIG_PPP_FILTER */
1537 }
1538
1539 ++ppp->stats64.tx_packets;
1540 ppp->stats64.tx_bytes += skb->len - 2;
1541
1542 switch (proto) {
1543 case PPP_IP:
1544 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1545 break;
1546 /* try to do VJ TCP header compression */
1547 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1548 GFP_ATOMIC);
1549 if (!new_skb) {
1550 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n");
1551 goto drop;
1552 }
1553 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1554 cp = skb->data + 2;
1555 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1556 new_skb->data + 2, &cp,
1557 !(ppp->flags & SC_NO_TCP_CCID));
1558 if (cp == skb->data + 2) {
1559 /* didn't compress */
1560 consume_skb(new_skb);
1561 } else {
1562 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1563 proto = PPP_VJC_COMP;
1564 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1565 } else {
1566 proto = PPP_VJC_UNCOMP;
1567 cp[0] = skb->data[2];
1568 }
1569 consume_skb(skb);
1570 skb = new_skb;
1571 cp = skb_put(skb, len + 2);
1572 cp[0] = 0;
1573 cp[1] = proto;
1574 }
1575 break;
1576
1577 case PPP_CCP:
1578 /* peek at outbound CCP frames */
1579 ppp_ccp_peek(ppp, skb, 0);
1580 break;
1581 }
1582
1583 /* try to do packet compression */
1584 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state &&
1585 proto != PPP_LCP && proto != PPP_CCP) {
1586 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1587 if (net_ratelimit())
1588 netdev_err(ppp->dev,
1589 "ppp: compression required but "
1590 "down - pkt dropped.\n");
1591 goto drop;
1592 }
1593 skb = pad_compress_skb(ppp, skb);
1594 if (!skb)
1595 goto drop;
1596 }
1597
1598 /*
1599 * If we are waiting for traffic (demand dialling),
1600 * queue it up for pppd to receive.
1601 */
1602 if (ppp->flags & SC_LOOP_TRAFFIC) {
1603 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1604 goto drop;
1605 skb_queue_tail(&ppp->file.rq, skb);
1606 wake_up_interruptible(&ppp->file.rwait);
1607 return;
1608 }
1609
1610 ppp->xmit_pending = skb;
1611 ppp_push(ppp);
1612 return;
1613
1614 drop:
1615 kfree_skb(skb);
1616 ++ppp->dev->stats.tx_errors;
1617 }
1618
1619 /*
1620 * Try to send the frame in xmit_pending.
1621 * The caller should have the xmit path locked.
1622 */
1623 static void
1624 ppp_push(struct ppp *ppp)
1625 {
1626 struct list_head *list;
1627 struct channel *pch;
1628 struct sk_buff *skb = ppp->xmit_pending;
1629
1630 if (!skb)
1631 return;
1632
1633 list = &ppp->channels;
1634 if (list_empty(list)) {
1635 /* nowhere to send the packet, just drop it */
1636 ppp->xmit_pending = NULL;
1637 kfree_skb(skb);
1638 return;
1639 }
1640
1641 if ((ppp->flags & SC_MULTILINK) == 0) {
1642 /* not doing multilink: send it down the first channel */
1643 list = list->next;
1644 pch = list_entry(list, struct channel, clist);
1645
1646 spin_lock(&pch->downl);
1647 if (pch->chan) {
1648 if (pch->chan->ops->start_xmit(pch->chan, skb))
1649 ppp->xmit_pending = NULL;
1650 } else {
1651 /* channel got unregistered */
1652 kfree_skb(skb);
1653 ppp->xmit_pending = NULL;
1654 }
1655 spin_unlock(&pch->downl);
1656 return;
1657 }
1658
1659 #ifdef CONFIG_PPP_MULTILINK
1660 /* Multilink: fragment the packet over as many links
1661 as can take the packet at the moment. */
1662 if (!ppp_mp_explode(ppp, skb))
1663 return;
1664 #endif /* CONFIG_PPP_MULTILINK */
1665
1666 ppp->xmit_pending = NULL;
1667 kfree_skb(skb);
1668 }
1669
1670 #ifdef CONFIG_PPP_MULTILINK
1671 static bool mp_protocol_compress __read_mostly = true;
1672 module_param(mp_protocol_compress, bool, 0644);
1673 MODULE_PARM_DESC(mp_protocol_compress,
1674 "compress protocol id in multilink fragments");
1675
1676 /*
1677 * Divide a packet to be transmitted into fragments and
1678 * send them out the individual links.
1679 */
1680 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1681 {
1682 int len, totlen;
1683 int i, bits, hdrlen, mtu;
1684 int flen;
1685 int navail, nfree, nzero;
1686 int nbigger;
1687 int totspeed;
1688 int totfree;
1689 unsigned char *p, *q;
1690 struct list_head *list;
1691 struct channel *pch;
1692 struct sk_buff *frag;
1693 struct ppp_channel *chan;
1694
1695 totspeed = 0; /*total bitrate of the bundle*/
1696 nfree = 0; /* # channels which have no packet already queued */
1697 navail = 0; /* total # of usable channels (not deregistered) */
1698 nzero = 0; /* number of channels with zero speed associated*/
1699 totfree = 0; /*total # of channels available and
1700 *having no queued packets before
1701 *starting the fragmentation*/
1702
1703 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1704 i = 0;
1705 list_for_each_entry(pch, &ppp->channels, clist) {
1706 if (pch->chan) {
1707 pch->avail = 1;
1708 navail++;
1709 pch->speed = pch->chan->speed;
1710 } else {
1711 pch->avail = 0;
1712 }
1713 if (pch->avail) {
1714 if (skb_queue_empty(&pch->file.xq) ||
1715 !pch->had_frag) {
1716 if (pch->speed == 0)
1717 nzero++;
1718 else
1719 totspeed += pch->speed;
1720
1721 pch->avail = 2;
1722 ++nfree;
1723 ++totfree;
1724 }
1725 if (!pch->had_frag && i < ppp->nxchan)
1726 ppp->nxchan = i;
1727 }
1728 ++i;
1729 }
1730 /*
1731 * Don't start sending this packet unless at least half of
1732 * the channels are free. This gives much better TCP
1733 * performance if we have a lot of channels.
1734 */
1735 if (nfree == 0 || nfree < navail / 2)
1736 return 0; /* can't take now, leave it in xmit_pending */
1737
1738 /* Do protocol field compression */
1739 p = skb->data;
1740 len = skb->len;
1741 if (*p == 0 && mp_protocol_compress) {
1742 ++p;
1743 --len;
1744 }
1745
1746 totlen = len;
1747 nbigger = len % nfree;
1748
1749 /* skip to the channel after the one we last used
1750 and start at that one */
1751 list = &ppp->channels;
1752 for (i = 0; i < ppp->nxchan; ++i) {
1753 list = list->next;
1754 if (list == &ppp->channels) {
1755 i = 0;
1756 break;
1757 }
1758 }
1759
1760 /* create a fragment for each channel */
1761 bits = B;
1762 while (len > 0) {
1763 list = list->next;
1764 if (list == &ppp->channels) {
1765 i = 0;
1766 continue;
1767 }
1768 pch = list_entry(list, struct channel, clist);
1769 ++i;
1770 if (!pch->avail)
1771 continue;
1772
1773 /*
1774 * Skip this channel if it has a fragment pending already and
1775 * we haven't given a fragment to all of the free channels.
1776 */
1777 if (pch->avail == 1) {
1778 if (nfree > 0)
1779 continue;
1780 } else {
1781 pch->avail = 1;
1782 }
1783
1784 /* check the channel's mtu and whether it is still attached. */
1785 spin_lock(&pch->downl);
1786 if (pch->chan == NULL) {
1787 /* can't use this channel, it's being deregistered */
1788 if (pch->speed == 0)
1789 nzero--;
1790 else
1791 totspeed -= pch->speed;
1792
1793 spin_unlock(&pch->downl);
1794 pch->avail = 0;
1795 totlen = len;
1796 totfree--;
1797 nfree--;
1798 if (--navail == 0)
1799 break;
1800 continue;
1801 }
1802
1803 /*
1804 *if the channel speed is not set divide
1805 *the packet evenly among the free channels;
1806 *otherwise divide it according to the speed
1807 *of the channel we are going to transmit on
1808 */
1809 flen = len;
1810 if (nfree > 0) {
1811 if (pch->speed == 0) {
1812 flen = len/nfree;
1813 if (nbigger > 0) {
1814 flen++;
1815 nbigger--;
1816 }
1817 } else {
1818 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
1819 ((totspeed*totfree)/pch->speed)) - hdrlen;
1820 if (nbigger > 0) {
1821 flen += ((totfree - nzero)*pch->speed)/totspeed;
1822 nbigger -= ((totfree - nzero)*pch->speed)/
1823 totspeed;
1824 }
1825 }
1826 nfree--;
1827 }
1828
1829 /*
1830 *check if we are on the last channel or
1831 *we exceded the length of the data to
1832 *fragment
1833 */
1834 if ((nfree <= 0) || (flen > len))
1835 flen = len;
1836 /*
1837 *it is not worth to tx on slow channels:
1838 *in that case from the resulting flen according to the
1839 *above formula will be equal or less than zero.
1840 *Skip the channel in this case
1841 */
1842 if (flen <= 0) {
1843 pch->avail = 2;
1844 spin_unlock(&pch->downl);
1845 continue;
1846 }
1847
1848 /*
1849 * hdrlen includes the 2-byte PPP protocol field, but the
1850 * MTU counts only the payload excluding the protocol field.
1851 * (RFC1661 Section 2)
1852 */
1853 mtu = pch->chan->mtu - (hdrlen - 2);
1854 if (mtu < 4)
1855 mtu = 4;
1856 if (flen > mtu)
1857 flen = mtu;
1858 if (flen == len)
1859 bits |= E;
1860 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1861 if (!frag)
1862 goto noskb;
1863 q = skb_put(frag, flen + hdrlen);
1864
1865 /* make the MP header */
1866 put_unaligned_be16(PPP_MP, q);
1867 if (ppp->flags & SC_MP_XSHORTSEQ) {
1868 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1869 q[3] = ppp->nxseq;
1870 } else {
1871 q[2] = bits;
1872 q[3] = ppp->nxseq >> 16;
1873 q[4] = ppp->nxseq >> 8;
1874 q[5] = ppp->nxseq;
1875 }
1876
1877 memcpy(q + hdrlen, p, flen);
1878
1879 /* try to send it down the channel */
1880 chan = pch->chan;
1881 if (!skb_queue_empty(&pch->file.xq) ||
1882 !chan->ops->start_xmit(chan, frag))
1883 skb_queue_tail(&pch->file.xq, frag);
1884 pch->had_frag = 1;
1885 p += flen;
1886 len -= flen;
1887 ++ppp->nxseq;
1888 bits = 0;
1889 spin_unlock(&pch->downl);
1890 }
1891 ppp->nxchan = i;
1892
1893 return 1;
1894
1895 noskb:
1896 spin_unlock(&pch->downl);
1897 if (ppp->debug & 1)
1898 netdev_err(ppp->dev, "PPP: no memory (fragment)\n");
1899 ++ppp->dev->stats.tx_errors;
1900 ++ppp->nxseq;
1901 return 1; /* abandon the frame */
1902 }
1903 #endif /* CONFIG_PPP_MULTILINK */
1904
1905 /* Try to send data out on a channel */
1906 static void __ppp_channel_push(struct channel *pch)
1907 {
1908 struct sk_buff *skb;
1909 struct ppp *ppp;
1910
1911 spin_lock(&pch->downl);
1912 if (pch->chan) {
1913 while (!skb_queue_empty(&pch->file.xq)) {
1914 skb = skb_dequeue(&pch->file.xq);
1915 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1916 /* put the packet back and try again later */
1917 skb_queue_head(&pch->file.xq, skb);
1918 break;
1919 }
1920 }
1921 } else {
1922 /* channel got deregistered */
1923 skb_queue_purge(&pch->file.xq);
1924 }
1925 spin_unlock(&pch->downl);
1926 /* see if there is anything from the attached unit to be sent */
1927 if (skb_queue_empty(&pch->file.xq)) {
1928 ppp = pch->ppp;
1929 if (ppp)
1930 __ppp_xmit_process(ppp, NULL);
1931 }
1932 }
1933
1934 static void ppp_channel_push(struct channel *pch)
1935 {
1936 read_lock_bh(&pch->upl);
1937 if (pch->ppp) {
1938 (*this_cpu_ptr(pch->ppp->xmit_recursion))++;
1939 __ppp_channel_push(pch);
1940 (*this_cpu_ptr(pch->ppp->xmit_recursion))--;
1941 } else {
1942 __ppp_channel_push(pch);
1943 }
1944 read_unlock_bh(&pch->upl);
1945 }
1946
1947 /*
1948 * Receive-side routines.
1949 */
1950
1951 struct ppp_mp_skb_parm {
1952 u32 sequence;
1953 u8 BEbits;
1954 };
1955 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb))
1956
1957 static inline void
1958 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1959 {
1960 ppp_recv_lock(ppp);
1961 if (!ppp->closing)
1962 ppp_receive_frame(ppp, skb, pch);
1963 else
1964 kfree_skb(skb);
1965 ppp_recv_unlock(ppp);
1966 }
1967
1968 /**
1969 * __ppp_decompress_proto - Decompress protocol field, slim version.
1970 * @skb: Socket buffer where protocol field should be decompressed. It must have
1971 * at least 1 byte of head room and 1 byte of linear data. First byte of
1972 * data must be a protocol field byte.
1973 *
1974 * Decompress protocol field in PPP header if it's compressed, e.g. when
1975 * Protocol-Field-Compression (PFC) was negotiated. No checks w.r.t. skb data
1976 * length are done in this function.
1977 */
1978 static void __ppp_decompress_proto(struct sk_buff *skb)
1979 {
1980 if (skb->data[0] & 0x01)
1981 *(u8 *)skb_push(skb, 1) = 0x00;
1982 }
1983
1984 /**
1985 * ppp_decompress_proto - Check skb data room and decompress protocol field.
1986 * @skb: Socket buffer where protocol field should be decompressed. First byte
1987 * of data must be a protocol field byte.
1988 *
1989 * Decompress protocol field in PPP header if it's compressed, e.g. when
1990 * Protocol-Field-Compression (PFC) was negotiated. This function also makes
1991 * sure that skb data room is sufficient for Protocol field, before and after
1992 * decompression.
1993 *
1994 * Return: true - decompressed successfully, false - not enough room in skb.
1995 */
1996 static bool ppp_decompress_proto(struct sk_buff *skb)
1997 {
1998 /* At least one byte should be present (if protocol is compressed) */
1999 if (!pskb_may_pull(skb, 1))
2000 return false;
2001
2002 __ppp_decompress_proto(skb);
2003
2004 /* Protocol field should occupy 2 bytes when not compressed */
2005 return pskb_may_pull(skb, 2);
2006 }
2007
2008 void
2009 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
2010 {
2011 struct channel *pch = chan->ppp;
2012 int proto;
2013
2014 if (!pch) {
2015 kfree_skb(skb);
2016 return;
2017 }
2018
2019 read_lock_bh(&pch->upl);
2020 if (!ppp_decompress_proto(skb)) {
2021 kfree_skb(skb);
2022 if (pch->ppp) {
2023 ++pch->ppp->dev->stats.rx_length_errors;
2024 ppp_receive_error(pch->ppp);
2025 }
2026 goto done;
2027 }
2028
2029 proto = PPP_PROTO(skb);
2030 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
2031 /* put it on the channel queue */
2032 skb_queue_tail(&pch->file.rq, skb);
2033 /* drop old frames if queue too long */
2034 while (pch->file.rq.qlen > PPP_MAX_RQLEN &&
2035 (skb = skb_dequeue(&pch->file.rq)))
2036 kfree_skb(skb);
2037 wake_up_interruptible(&pch->file.rwait);
2038 } else {
2039 ppp_do_recv(pch->ppp, skb, pch);
2040 }
2041
2042 done:
2043 read_unlock_bh(&pch->upl);
2044 }
2045
2046 /* Put a 0-length skb in the receive queue as an error indication */
2047 void
2048 ppp_input_error(struct ppp_channel *chan, int code)
2049 {
2050 struct channel *pch = chan->ppp;
2051 struct sk_buff *skb;
2052
2053 if (!pch)
2054 return;
2055
2056 read_lock_bh(&pch->upl);
2057 if (pch->ppp) {
2058 skb = alloc_skb(0, GFP_ATOMIC);
2059 if (skb) {
2060 skb->len = 0; /* probably unnecessary */
2061 skb->cb[0] = code;
2062 ppp_do_recv(pch->ppp, skb, pch);
2063 }
2064 }
2065 read_unlock_bh(&pch->upl);
2066 }
2067
2068 /*
2069 * We come in here to process a received frame.
2070 * The receive side of the ppp unit is locked.
2071 */
2072 static void
2073 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
2074 {
2075 /* note: a 0-length skb is used as an error indication */
2076 if (skb->len > 0) {
2077 skb_checksum_complete_unset(skb);
2078 #ifdef CONFIG_PPP_MULTILINK
2079 /* XXX do channel-level decompression here */
2080 if (PPP_PROTO(skb) == PPP_MP)
2081 ppp_receive_mp_frame(ppp, skb, pch);
2082 else
2083 #endif /* CONFIG_PPP_MULTILINK */
2084 ppp_receive_nonmp_frame(ppp, skb);
2085 } else {
2086 kfree_skb(skb);
2087 ppp_receive_error(ppp);
2088 }
2089 }
2090
2091 static void
2092 ppp_receive_error(struct ppp *ppp)
2093 {
2094 ++ppp->dev->stats.rx_errors;
2095 if (ppp->vj)
2096 slhc_toss(ppp->vj);
2097 }
2098
2099 static void
2100 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
2101 {
2102 struct sk_buff *ns;
2103 int proto, len, npi;
2104
2105 /*
2106 * Decompress the frame, if compressed.
2107 * Note that some decompressors need to see uncompressed frames
2108 * that come in as well as compressed frames.
2109 */
2110 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) &&
2111 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
2112 skb = ppp_decompress_frame(ppp, skb);
2113
2114 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
2115 goto err;
2116
2117 /* At this point the "Protocol" field MUST be decompressed, either in
2118 * ppp_input(), ppp_decompress_frame() or in ppp_receive_mp_frame().
2119 */
2120 proto = PPP_PROTO(skb);
2121 switch (proto) {
2122 case PPP_VJC_COMP:
2123 /* decompress VJ compressed packets */
2124 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
2125 goto err;
2126
2127 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
2128 /* copy to a new sk_buff with more tailroom */
2129 ns = dev_alloc_skb(skb->len + 128);
2130 if (!ns) {
2131 netdev_err(ppp->dev, "PPP: no memory "
2132 "(VJ decomp)\n");
2133 goto err;
2134 }
2135 skb_reserve(ns, 2);
2136 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
2137 consume_skb(skb);
2138 skb = ns;
2139 }
2140 else
2141 skb->ip_summed = CHECKSUM_NONE;
2142
2143 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
2144 if (len <= 0) {
2145 netdev_printk(KERN_DEBUG, ppp->dev,
2146 "PPP: VJ decompression error\n");
2147 goto err;
2148 }
2149 len += 2;
2150 if (len > skb->len)
2151 skb_put(skb, len - skb->len);
2152 else if (len < skb->len)
2153 skb_trim(skb, len);
2154 proto = PPP_IP;
2155 break;
2156
2157 case PPP_VJC_UNCOMP:
2158 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
2159 goto err;
2160
2161 /* Until we fix the decompressor need to make sure
2162 * data portion is linear.
2163 */
2164 if (!pskb_may_pull(skb, skb->len))
2165 goto err;
2166
2167 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
2168 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n");
2169 goto err;
2170 }
2171 proto = PPP_IP;
2172 break;
2173
2174 case PPP_CCP:
2175 ppp_ccp_peek(ppp, skb, 1);
2176 break;
2177 }
2178
2179 ++ppp->stats64.rx_packets;
2180 ppp->stats64.rx_bytes += skb->len - 2;
2181
2182 npi = proto_to_npindex(proto);
2183 if (npi < 0) {
2184 /* control or unknown frame - pass it to pppd */
2185 skb_queue_tail(&ppp->file.rq, skb);
2186 /* limit queue length by dropping old frames */
2187 while (ppp->file.rq.qlen > PPP_MAX_RQLEN &&
2188 (skb = skb_dequeue(&ppp->file.rq)))
2189 kfree_skb(skb);
2190 /* wake up any process polling or blocking on read */
2191 wake_up_interruptible(&ppp->file.rwait);
2192
2193 } else {
2194 /* network protocol frame - give it to the kernel */
2195
2196 #ifdef CONFIG_PPP_FILTER
2197 /* check if the packet passes the pass and active filters */
2198 /* the filter instructions are constructed assuming
2199 a four-byte PPP header on each packet */
2200 if (ppp->pass_filter || ppp->active_filter) {
2201 if (skb_unclone(skb, GFP_ATOMIC))
2202 goto err;
2203
2204 *(u8 *)skb_push(skb, 2) = 0;
2205 if (ppp->pass_filter &&
2206 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
2207 if (ppp->debug & 1)
2208 netdev_printk(KERN_DEBUG, ppp->dev,
2209 "PPP: inbound frame "
2210 "not passed\n");
2211 kfree_skb(skb);
2212 return;
2213 }
2214 if (!(ppp->active_filter &&
2215 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
2216 ppp->last_recv = jiffies;
2217 __skb_pull(skb, 2);
2218 } else
2219 #endif /* CONFIG_PPP_FILTER */
2220 ppp->last_recv = jiffies;
2221
2222 if ((ppp->dev->flags & IFF_UP) == 0 ||
2223 ppp->npmode[npi] != NPMODE_PASS) {
2224 kfree_skb(skb);
2225 } else {
2226 /* chop off protocol */
2227 skb_pull_rcsum(skb, 2);
2228 skb->dev = ppp->dev;
2229 skb->protocol = htons(npindex_to_ethertype[npi]);
2230 skb_reset_mac_header(skb);
2231 skb_scrub_packet(skb, !net_eq(ppp->ppp_net,
2232 dev_net(ppp->dev)));
2233 netif_rx(skb);
2234 }
2235 }
2236 return;
2237
2238 err:
2239 kfree_skb(skb);
2240 ppp_receive_error(ppp);
2241 }
2242
2243 static struct sk_buff *
2244 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
2245 {
2246 int proto = PPP_PROTO(skb);
2247 struct sk_buff *ns;
2248 int len;
2249
2250 /* Until we fix all the decompressor's need to make sure
2251 * data portion is linear.
2252 */
2253 if (!pskb_may_pull(skb, skb->len))
2254 goto err;
2255
2256 if (proto == PPP_COMP) {
2257 int obuff_size;
2258
2259 switch(ppp->rcomp->compress_proto) {
2260 case CI_MPPE:
2261 obuff_size = ppp->mru + PPP_HDRLEN + 1;
2262 break;
2263 default:
2264 obuff_size = ppp->mru + PPP_HDRLEN;
2265 break;
2266 }
2267
2268 ns = dev_alloc_skb(obuff_size);
2269 if (!ns) {
2270 netdev_err(ppp->dev, "ppp_decompress_frame: "
2271 "no memory\n");
2272 goto err;
2273 }
2274 /* the decompressor still expects the A/C bytes in the hdr */
2275 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
2276 skb->len + 2, ns->data, obuff_size);
2277 if (len < 0) {
2278 /* Pass the compressed frame to pppd as an
2279 error indication. */
2280 if (len == DECOMP_FATALERROR)
2281 ppp->rstate |= SC_DC_FERROR;
2282 kfree_skb(ns);
2283 goto err;
2284 }
2285
2286 consume_skb(skb);
2287 skb = ns;
2288 skb_put(skb, len);
2289 skb_pull(skb, 2); /* pull off the A/C bytes */
2290
2291 /* Don't call __ppp_decompress_proto() here, but instead rely on
2292 * corresponding algo (mppe/bsd/deflate) to decompress it.
2293 */
2294 } else {
2295 /* Uncompressed frame - pass to decompressor so it
2296 can update its dictionary if necessary. */
2297 if (ppp->rcomp->incomp)
2298 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
2299 skb->len + 2);
2300 }
2301
2302 return skb;
2303
2304 err:
2305 ppp->rstate |= SC_DC_ERROR;
2306 ppp_receive_error(ppp);
2307 return skb;
2308 }
2309
2310 #ifdef CONFIG_PPP_MULTILINK
2311 /*
2312 * Receive a multilink frame.
2313 * We put it on the reconstruction queue and then pull off
2314 * as many completed frames as we can.
2315 */
2316 static void
2317 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
2318 {
2319 u32 mask, seq;
2320 struct channel *ch;
2321 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
2322
2323 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
2324 goto err; /* no good, throw it away */
2325
2326 /* Decode sequence number and begin/end bits */
2327 if (ppp->flags & SC_MP_SHORTSEQ) {
2328 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
2329 mask = 0xfff;
2330 } else {
2331 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
2332 mask = 0xffffff;
2333 }
2334 PPP_MP_CB(skb)->BEbits = skb->data[2];
2335 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
2336
2337 /*
2338 * Do protocol ID decompression on the first fragment of each packet.
2339 * We have to do that here, because ppp_receive_nonmp_frame() expects
2340 * decompressed protocol field.
2341 */
2342 if (PPP_MP_CB(skb)->BEbits & B)
2343 __ppp_decompress_proto(skb);
2344
2345 /*
2346 * Expand sequence number to 32 bits, making it as close
2347 * as possible to ppp->minseq.
2348 */
2349 seq |= ppp->minseq & ~mask;
2350 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
2351 seq += mask + 1;
2352 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
2353 seq -= mask + 1; /* should never happen */
2354 PPP_MP_CB(skb)->sequence = seq;
2355 pch->lastseq = seq;
2356
2357 /*
2358 * If this packet comes before the next one we were expecting,
2359 * drop it.
2360 */
2361 if (seq_before(seq, ppp->nextseq)) {
2362 kfree_skb(skb);
2363 ++ppp->dev->stats.rx_dropped;
2364 ppp_receive_error(ppp);
2365 return;
2366 }
2367
2368 /*
2369 * Reevaluate minseq, the minimum over all channels of the
2370 * last sequence number received on each channel. Because of
2371 * the increasing sequence number rule, we know that any fragment
2372 * before `minseq' which hasn't arrived is never going to arrive.
2373 * The list of channels can't change because we have the receive
2374 * side of the ppp unit locked.
2375 */
2376 list_for_each_entry(ch, &ppp->channels, clist) {
2377 if (seq_before(ch->lastseq, seq))
2378 seq = ch->lastseq;
2379 }
2380 if (seq_before(ppp->minseq, seq))
2381 ppp->minseq = seq;
2382
2383 /* Put the fragment on the reconstruction queue */
2384 ppp_mp_insert(ppp, skb);
2385
2386 /* If the queue is getting long, don't wait any longer for packets
2387 before the start of the queue. */
2388 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
2389 struct sk_buff *mskb = skb_peek(&ppp->mrq);
2390 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence))
2391 ppp->minseq = PPP_MP_CB(mskb)->sequence;
2392 }
2393
2394 /* Pull completed packets off the queue and receive them. */
2395 while ((skb = ppp_mp_reconstruct(ppp))) {
2396 if (pskb_may_pull(skb, 2))
2397 ppp_receive_nonmp_frame(ppp, skb);
2398 else {
2399 ++ppp->dev->stats.rx_length_errors;
2400 kfree_skb(skb);
2401 ppp_receive_error(ppp);
2402 }
2403 }
2404
2405 return;
2406
2407 err:
2408 kfree_skb(skb);
2409 ppp_receive_error(ppp);
2410 }
2411
2412 /*
2413 * Insert a fragment on the MP reconstruction queue.
2414 * The queue is ordered by increasing sequence number.
2415 */
2416 static void
2417 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
2418 {
2419 struct sk_buff *p;
2420 struct sk_buff_head *list = &ppp->mrq;
2421 u32 seq = PPP_MP_CB(skb)->sequence;
2422
2423 /* N.B. we don't need to lock the list lock because we have the
2424 ppp unit receive-side lock. */
2425 skb_queue_walk(list, p) {
2426 if (seq_before(seq, PPP_MP_CB(p)->sequence))
2427 break;
2428 }
2429 __skb_queue_before(list, p, skb);
2430 }
2431
2432 /*
2433 * Reconstruct a packet from the MP fragment queue.
2434 * We go through increasing sequence numbers until we find a
2435 * complete packet, or we get to the sequence number for a fragment
2436 * which hasn't arrived but might still do so.
2437 */
2438 static struct sk_buff *
2439 ppp_mp_reconstruct(struct ppp *ppp)
2440 {
2441 u32 seq = ppp->nextseq;
2442 u32 minseq = ppp->minseq;
2443 struct sk_buff_head *list = &ppp->mrq;
2444 struct sk_buff *p, *tmp;
2445 struct sk_buff *head, *tail;
2446 struct sk_buff *skb = NULL;
2447 int lost = 0, len = 0;
2448
2449 if (ppp->mrru == 0) /* do nothing until mrru is set */
2450 return NULL;
2451 head = __skb_peek(list);
2452 tail = NULL;
2453 skb_queue_walk_safe(list, p, tmp) {
2454 again:
2455 if (seq_before(PPP_MP_CB(p)->sequence, seq)) {
2456 /* this can't happen, anyway ignore the skb */
2457 netdev_err(ppp->dev, "ppp_mp_reconstruct bad "
2458 "seq %u < %u\n",
2459 PPP_MP_CB(p)->sequence, seq);
2460 __skb_unlink(p, list);
2461 kfree_skb(p);
2462 continue;
2463 }
2464 if (PPP_MP_CB(p)->sequence != seq) {
2465 u32 oldseq;
2466 /* Fragment `seq' is missing. If it is after
2467 minseq, it might arrive later, so stop here. */
2468 if (seq_after(seq, minseq))
2469 break;
2470 /* Fragment `seq' is lost, keep going. */
2471 lost = 1;
2472 oldseq = seq;
2473 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)?
2474 minseq + 1: PPP_MP_CB(p)->sequence;
2475
2476 if (ppp->debug & 1)
2477 netdev_printk(KERN_DEBUG, ppp->dev,
2478 "lost frag %u..%u\n",
2479 oldseq, seq-1);
2480
2481 goto again;
2482 }
2483
2484 /*
2485 * At this point we know that all the fragments from
2486 * ppp->nextseq to seq are either present or lost.
2487 * Also, there are no complete packets in the queue
2488 * that have no missing fragments and end before this
2489 * fragment.
2490 */
2491
2492 /* B bit set indicates this fragment starts a packet */
2493 if (PPP_MP_CB(p)->BEbits & B) {
2494 head = p;
2495 lost = 0;
2496 len = 0;
2497 }
2498
2499 len += p->len;
2500
2501 /* Got a complete packet yet? */
2502 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) &&
2503 (PPP_MP_CB(head)->BEbits & B)) {
2504 if (len > ppp->mrru + 2) {
2505 ++ppp->dev->stats.rx_length_errors;
2506 netdev_printk(KERN_DEBUG, ppp->dev,
2507 "PPP: reconstructed packet"
2508 " is too long (%d)\n", len);
2509 } else {
2510 tail = p;
2511 break;
2512 }
2513 ppp->nextseq = seq + 1;
2514 }
2515
2516 /*
2517 * If this is the ending fragment of a packet,
2518 * and we haven't found a complete valid packet yet,
2519 * we can discard up to and including this fragment.
2520 */
2521 if (PPP_MP_CB(p)->BEbits & E) {
2522 struct sk_buff *tmp2;
2523
2524 skb_queue_reverse_walk_from_safe(list, p, tmp2) {
2525 if (ppp->debug & 1)
2526 netdev_printk(KERN_DEBUG, ppp->dev,
2527 "discarding frag %u\n",
2528 PPP_MP_CB(p)->sequence);
2529 __skb_unlink(p, list);
2530 kfree_skb(p);
2531 }
2532 head = skb_peek(list);
2533 if (!head)
2534 break;
2535 }
2536 ++seq;
2537 }
2538
2539 /* If we have a complete packet, copy it all into one skb. */
2540 if (tail != NULL) {
2541 /* If we have discarded any fragments,
2542 signal a receive error. */
2543 if (PPP_MP_CB(head)->sequence != ppp->nextseq) {
2544 skb_queue_walk_safe(list, p, tmp) {
2545 if (p == head)
2546 break;
2547 if (ppp->debug & 1)
2548 netdev_printk(KERN_DEBUG, ppp->dev,
2549 "discarding frag %u\n",
2550 PPP_MP_CB(p)->sequence);
2551 __skb_unlink(p, list);
2552 kfree_skb(p);
2553 }
2554
2555 if (ppp->debug & 1)
2556 netdev_printk(KERN_DEBUG, ppp->dev,
2557 " missed pkts %u..%u\n",
2558 ppp->nextseq,
2559 PPP_MP_CB(head)->sequence-1);
2560 ++ppp->dev->stats.rx_dropped;
2561 ppp_receive_error(ppp);
2562 }
2563
2564 skb = head;
2565 if (head != tail) {
2566 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list;
2567 p = skb_queue_next(list, head);
2568 __skb_unlink(skb, list);
2569 skb_queue_walk_from_safe(list, p, tmp) {
2570 __skb_unlink(p, list);
2571 *fragpp = p;
2572 p->next = NULL;
2573 fragpp = &p->next;
2574
2575 skb->len += p->len;
2576 skb->data_len += p->len;
2577 skb->truesize += p->truesize;
2578
2579 if (p == tail)
2580 break;
2581 }
2582 } else {
2583 __skb_unlink(skb, list);
2584 }
2585
2586 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1;
2587 }
2588
2589 return skb;
2590 }
2591 #endif /* CONFIG_PPP_MULTILINK */
2592
2593 /*
2594 * Channel interface.
2595 */
2596
2597 /* Create a new, unattached ppp channel. */
2598 int ppp_register_channel(struct ppp_channel *chan)
2599 {
2600 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2601 }
2602
2603 /* Create a new, unattached ppp channel for specified net. */
2604 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
2605 {
2606 struct channel *pch;
2607 struct ppp_net *pn;
2608
2609 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2610 if (!pch)
2611 return -ENOMEM;
2612
2613 pn = ppp_pernet(net);
2614
2615 pch->ppp = NULL;
2616 pch->chan = chan;
2617 pch->chan_net = get_net(net);
2618 chan->ppp = pch;
2619 init_ppp_file(&pch->file, CHANNEL);
2620 pch->file.hdrlen = chan->hdrlen;
2621 #ifdef CONFIG_PPP_MULTILINK
2622 pch->lastseq = -1;
2623 #endif /* CONFIG_PPP_MULTILINK */
2624 init_rwsem(&pch->chan_sem);
2625 spin_lock_init(&pch->downl);
2626 rwlock_init(&pch->upl);
2627
2628 spin_lock_bh(&pn->all_channels_lock);
2629 pch->file.index = ++pn->last_channel_index;
2630 list_add(&pch->list, &pn->new_channels);
2631 atomic_inc(&channel_count);
2632 spin_unlock_bh(&pn->all_channels_lock);
2633
2634 return 0;
2635 }
2636
2637 /*
2638 * Return the index of a channel.
2639 */
2640 int ppp_channel_index(struct ppp_channel *chan)
2641 {
2642 struct channel *pch = chan->ppp;
2643
2644 if (pch)
2645 return pch->file.index;
2646 return -1;
2647 }
2648
2649 /*
2650 * Return the PPP unit number to which a channel is connected.
2651 */
2652 int ppp_unit_number(struct ppp_channel *chan)
2653 {
2654 struct channel *pch = chan->ppp;
2655 int unit = -1;
2656
2657 if (pch) {
2658 read_lock_bh(&pch->upl);
2659 if (pch->ppp)
2660 unit = pch->ppp->file.index;
2661 read_unlock_bh(&pch->upl);
2662 }
2663 return unit;
2664 }
2665
2666 /*
2667 * Return the PPP device interface name of a channel.
2668 */
2669 char *ppp_dev_name(struct ppp_channel *chan)
2670 {
2671 struct channel *pch = chan->ppp;
2672 char *name = NULL;
2673
2674 if (pch) {
2675 read_lock_bh(&pch->upl);
2676 if (pch->ppp && pch->ppp->dev)
2677 name = pch->ppp->dev->name;
2678 read_unlock_bh(&pch->upl);
2679 }
2680 return name;
2681 }
2682
2683
2684 /*
2685 * Disconnect a channel from the generic layer.
2686 * This must be called in process context.
2687 */
2688 void
2689 ppp_unregister_channel(struct ppp_channel *chan)
2690 {
2691 struct channel *pch = chan->ppp;
2692 struct ppp_net *pn;
2693
2694 if (!pch)
2695 return; /* should never happen */
2696
2697 chan->ppp = NULL;
2698
2699 /*
2700 * This ensures that we have returned from any calls into the
2701 * the channel's start_xmit or ioctl routine before we proceed.
2702 */
2703 down_write(&pch->chan_sem);
2704 spin_lock_bh(&pch->downl);
2705 pch->chan = NULL;
2706 spin_unlock_bh(&pch->downl);
2707 up_write(&pch->chan_sem);
2708 ppp_disconnect_channel(pch);
2709
2710 pn = ppp_pernet(pch->chan_net);
2711 spin_lock_bh(&pn->all_channels_lock);
2712 list_del(&pch->list);
2713 spin_unlock_bh(&pn->all_channels_lock);
2714
2715 pch->file.dead = 1;
2716 wake_up_interruptible(&pch->file.rwait);
2717 if (refcount_dec_and_test(&pch->file.refcnt))
2718 ppp_destroy_channel(pch);
2719 }
2720
2721 /*
2722 * Callback from a channel when it can accept more to transmit.
2723 * This should be called at BH/softirq level, not interrupt level.
2724 */
2725 void
2726 ppp_output_wakeup(struct ppp_channel *chan)
2727 {
2728 struct channel *pch = chan->ppp;
2729
2730 if (!pch)
2731 return;
2732 ppp_channel_push(pch);
2733 }
2734
2735 /*
2736 * Compression control.
2737 */
2738
2739 /* Process the PPPIOCSCOMPRESS ioctl. */
2740 static int
2741 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2742 {
2743 int err;
2744 struct compressor *cp, *ocomp;
2745 struct ppp_option_data data;
2746 void *state, *ostate;
2747 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2748
2749 err = -EFAULT;
2750 if (copy_from_user(&data, (void __user *) arg, sizeof(data)))
2751 goto out;
2752 if (data.length > CCP_MAX_OPTION_LENGTH)
2753 goto out;
2754 if (copy_from_user(ccp_option, (void __user *) data.ptr, data.length))
2755 goto out;
2756
2757 err = -EINVAL;
2758 if (data.length < 2 || ccp_option[1] < 2 || ccp_option[1] > data.length)
2759 goto out;
2760
2761 cp = try_then_request_module(
2762 find_compressor(ccp_option[0]),
2763 "ppp-compress-%d", ccp_option[0]);
2764 if (!cp)
2765 goto out;
2766
2767 err = -ENOBUFS;
2768 if (data.transmit) {
2769 state = cp->comp_alloc(ccp_option, data.length);
2770 if (state) {
2771 ppp_xmit_lock(ppp);
2772 ppp->xstate &= ~SC_COMP_RUN;
2773 ocomp = ppp->xcomp;
2774 ostate = ppp->xc_state;
2775 ppp->xcomp = cp;
2776 ppp->xc_state = state;
2777 ppp_xmit_unlock(ppp);
2778 if (ostate) {
2779 ocomp->comp_free(ostate);
2780 module_put(ocomp->owner);
2781 }
2782 err = 0;
2783 } else
2784 module_put(cp->owner);
2785
2786 } else {
2787 state = cp->decomp_alloc(ccp_option, data.length);
2788 if (state) {
2789 ppp_recv_lock(ppp);
2790 ppp->rstate &= ~SC_DECOMP_RUN;
2791 ocomp = ppp->rcomp;
2792 ostate = ppp->rc_state;
2793 ppp->rcomp = cp;
2794 ppp->rc_state = state;
2795 ppp_recv_unlock(ppp);
2796 if (ostate) {
2797 ocomp->decomp_free(ostate);
2798 module_put(ocomp->owner);
2799 }
2800 err = 0;
2801 } else
2802 module_put(cp->owner);
2803 }
2804
2805 out:
2806 return err;
2807 }
2808
2809 /*
2810 * Look at a CCP packet and update our state accordingly.
2811 * We assume the caller has the xmit or recv path locked.
2812 */
2813 static void
2814 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2815 {
2816 unsigned char *dp;
2817 int len;
2818
2819 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2820 return; /* no header */
2821 dp = skb->data + 2;
2822
2823 switch (CCP_CODE(dp)) {
2824 case CCP_CONFREQ:
2825
2826 /* A ConfReq starts negotiation of compression
2827 * in one direction of transmission,
2828 * and hence brings it down...but which way?
2829 *
2830 * Remember:
2831 * A ConfReq indicates what the sender would like to receive
2832 */
2833 if(inbound)
2834 /* He is proposing what I should send */
2835 ppp->xstate &= ~SC_COMP_RUN;
2836 else
2837 /* I am proposing to what he should send */
2838 ppp->rstate &= ~SC_DECOMP_RUN;
2839
2840 break;
2841
2842 case CCP_TERMREQ:
2843 case CCP_TERMACK:
2844 /*
2845 * CCP is going down, both directions of transmission
2846 */
2847 ppp->rstate &= ~SC_DECOMP_RUN;
2848 ppp->xstate &= ~SC_COMP_RUN;
2849 break;
2850
2851 case CCP_CONFACK:
2852 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2853 break;
2854 len = CCP_LENGTH(dp);
2855 if (!pskb_may_pull(skb, len + 2))
2856 return; /* too short */
2857 dp += CCP_HDRLEN;
2858 len -= CCP_HDRLEN;
2859 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2860 break;
2861 if (inbound) {
2862 /* we will start receiving compressed packets */
2863 if (!ppp->rc_state)
2864 break;
2865 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2866 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2867 ppp->rstate |= SC_DECOMP_RUN;
2868 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2869 }
2870 } else {
2871 /* we will soon start sending compressed packets */
2872 if (!ppp->xc_state)
2873 break;
2874 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2875 ppp->file.index, 0, ppp->debug))
2876 ppp->xstate |= SC_COMP_RUN;
2877 }
2878 break;
2879
2880 case CCP_RESETACK:
2881 /* reset the [de]compressor */
2882 if ((ppp->flags & SC_CCP_UP) == 0)
2883 break;
2884 if (inbound) {
2885 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2886 ppp->rcomp->decomp_reset(ppp->rc_state);
2887 ppp->rstate &= ~SC_DC_ERROR;
2888 }
2889 } else {
2890 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2891 ppp->xcomp->comp_reset(ppp->xc_state);
2892 }
2893 break;
2894 }
2895 }
2896
2897 /* Free up compression resources. */
2898 static void
2899 ppp_ccp_closed(struct ppp *ppp)
2900 {
2901 void *xstate, *rstate;
2902 struct compressor *xcomp, *rcomp;
2903
2904 ppp_lock(ppp);
2905 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2906 ppp->xstate = 0;
2907 xcomp = ppp->xcomp;
2908 xstate = ppp->xc_state;
2909 ppp->xc_state = NULL;
2910 ppp->rstate = 0;
2911 rcomp = ppp->rcomp;
2912 rstate = ppp->rc_state;
2913 ppp->rc_state = NULL;
2914 ppp_unlock(ppp);
2915
2916 if (xstate) {
2917 xcomp->comp_free(xstate);
2918 module_put(xcomp->owner);
2919 }
2920 if (rstate) {
2921 rcomp->decomp_free(rstate);
2922 module_put(rcomp->owner);
2923 }
2924 }
2925
2926 /* List of compressors. */
2927 static LIST_HEAD(compressor_list);
2928 static DEFINE_SPINLOCK(compressor_list_lock);
2929
2930 struct compressor_entry {
2931 struct list_head list;
2932 struct compressor *comp;
2933 };
2934
2935 static struct compressor_entry *
2936 find_comp_entry(int proto)
2937 {
2938 struct compressor_entry *ce;
2939
2940 list_for_each_entry(ce, &compressor_list, list) {
2941 if (ce->comp->compress_proto == proto)
2942 return ce;
2943 }
2944 return NULL;
2945 }
2946
2947 /* Register a compressor */
2948 int
2949 ppp_register_compressor(struct compressor *cp)
2950 {
2951 struct compressor_entry *ce;
2952 int ret;
2953 spin_lock(&compressor_list_lock);
2954 ret = -EEXIST;
2955 if (find_comp_entry(cp->compress_proto))
2956 goto out;
2957 ret = -ENOMEM;
2958 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2959 if (!ce)
2960 goto out;
2961 ret = 0;
2962 ce->comp = cp;
2963 list_add(&ce->list, &compressor_list);
2964 out:
2965 spin_unlock(&compressor_list_lock);
2966 return ret;
2967 }
2968
2969 /* Unregister a compressor */
2970 void
2971 ppp_unregister_compressor(struct compressor *cp)
2972 {
2973 struct compressor_entry *ce;
2974
2975 spin_lock(&compressor_list_lock);
2976 ce = find_comp_entry(cp->compress_proto);
2977 if (ce && ce->comp == cp) {
2978 list_del(&ce->list);
2979 kfree(ce);
2980 }
2981 spin_unlock(&compressor_list_lock);
2982 }
2983
2984 /* Find a compressor. */
2985 static struct compressor *
2986 find_compressor(int type)
2987 {
2988 struct compressor_entry *ce;
2989 struct compressor *cp = NULL;
2990
2991 spin_lock(&compressor_list_lock);
2992 ce = find_comp_entry(type);
2993 if (ce) {
2994 cp = ce->comp;
2995 if (!try_module_get(cp->owner))
2996 cp = NULL;
2997 }
2998 spin_unlock(&compressor_list_lock);
2999 return cp;
3000 }
3001
3002 /*
3003 * Miscelleneous stuff.
3004 */
3005
3006 static void
3007 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
3008 {
3009 struct slcompress *vj = ppp->vj;
3010
3011 memset(st, 0, sizeof(*st));
3012 st->p.ppp_ipackets = ppp->stats64.rx_packets;
3013 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
3014 st->p.ppp_ibytes = ppp->stats64.rx_bytes;
3015 st->p.ppp_opackets = ppp->stats64.tx_packets;
3016 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
3017 st->p.ppp_obytes = ppp->stats64.tx_bytes;
3018 if (!vj)
3019 return;
3020 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
3021 st->vj.vjs_compressed = vj->sls_o_compressed;
3022 st->vj.vjs_searches = vj->sls_o_searches;
3023 st->vj.vjs_misses = vj->sls_o_misses;
3024 st->vj.vjs_errorin = vj->sls_i_error;
3025 st->vj.vjs_tossed = vj->sls_i_tossed;
3026 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
3027 st->vj.vjs_compressedin = vj->sls_i_compressed;
3028 }
3029
3030 /*
3031 * Stuff for handling the lists of ppp units and channels
3032 * and for initialization.
3033 */
3034
3035 /*
3036 * Create a new ppp interface unit. Fails if it can't allocate memory
3037 * or if there is already a unit with the requested number.
3038 * unit == -1 means allocate a new number.
3039 */
3040 static int ppp_create_interface(struct net *net, struct file *file, int *unit)
3041 {
3042 struct ppp_config conf = {
3043 .file = file,
3044 .unit = *unit,
3045 .ifname_is_set = false,
3046 };
3047 struct net_device *dev;
3048 struct ppp *ppp;
3049 int err;
3050
3051 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_ENUM, ppp_setup);
3052 if (!dev) {
3053 err = -ENOMEM;
3054 goto err;
3055 }
3056 dev_net_set(dev, net);
3057 dev->rtnl_link_ops = &ppp_link_ops;
3058
3059 rtnl_lock();
3060
3061 err = ppp_dev_configure(net, dev, &conf);
3062 if (err < 0)
3063 goto err_dev;
3064 ppp = netdev_priv(dev);
3065 *unit = ppp->file.index;
3066
3067 rtnl_unlock();
3068
3069 return 0;
3070
3071 err_dev:
3072 rtnl_unlock();
3073 free_netdev(dev);
3074 err:
3075 return err;
3076 }
3077
3078 /*
3079 * Initialize a ppp_file structure.
3080 */
3081 static void
3082 init_ppp_file(struct ppp_file *pf, int kind)
3083 {
3084 pf->kind = kind;
3085 skb_queue_head_init(&pf->xq);
3086 skb_queue_head_init(&pf->rq);
3087 refcount_set(&pf->refcnt, 1);
3088 init_waitqueue_head(&pf->rwait);
3089 }
3090
3091 /*
3092 * Free the memory used by a ppp unit. This is only called once
3093 * there are no channels connected to the unit and no file structs
3094 * that reference the unit.
3095 */
3096 static void ppp_destroy_interface(struct ppp *ppp)
3097 {
3098 atomic_dec(&ppp_unit_count);
3099
3100 if (!ppp->file.dead || ppp->n_channels) {
3101 /* "can't happen" */
3102 netdev_err(ppp->dev, "ppp: destroying ppp struct %p "
3103 "but dead=%d n_channels=%d !\n",
3104 ppp, ppp->file.dead, ppp->n_channels);
3105 return;
3106 }
3107
3108 ppp_ccp_closed(ppp);
3109 if (ppp->vj) {
3110 slhc_free(ppp->vj);
3111 ppp->vj = NULL;
3112 }
3113 skb_queue_purge(&ppp->file.xq);
3114 skb_queue_purge(&ppp->file.rq);
3115 #ifdef CONFIG_PPP_MULTILINK
3116 skb_queue_purge(&ppp->mrq);
3117 #endif /* CONFIG_PPP_MULTILINK */
3118 #ifdef CONFIG_PPP_FILTER
3119 if (ppp->pass_filter) {
3120 bpf_prog_destroy(ppp->pass_filter);
3121 ppp->pass_filter = NULL;
3122 }
3123
3124 if (ppp->active_filter) {
3125 bpf_prog_destroy(ppp->active_filter);
3126 ppp->active_filter = NULL;
3127 }
3128 #endif /* CONFIG_PPP_FILTER */
3129
3130 kfree_skb(ppp->xmit_pending);
3131 free_percpu(ppp->xmit_recursion);
3132
3133 free_netdev(ppp->dev);
3134 }
3135
3136 /*
3137 * Locate an existing ppp unit.
3138 * The caller should have locked the all_ppp_mutex.
3139 */
3140 static struct ppp *
3141 ppp_find_unit(struct ppp_net *pn, int unit)
3142 {
3143 return unit_find(&pn->units_idr, unit);
3144 }
3145
3146 /*
3147 * Locate an existing ppp channel.
3148 * The caller should have locked the all_channels_lock.
3149 * First we look in the new_channels list, then in the
3150 * all_channels list. If found in the new_channels list,
3151 * we move it to the all_channels list. This is for speed
3152 * when we have a lot of channels in use.
3153 */
3154 static struct channel *
3155 ppp_find_channel(struct ppp_net *pn, int unit)
3156 {
3157 struct channel *pch;
3158
3159 list_for_each_entry(pch, &pn->new_channels, list) {
3160 if (pch->file.index == unit) {
3161 list_move(&pch->list, &pn->all_channels);
3162 return pch;
3163 }
3164 }
3165
3166 list_for_each_entry(pch, &pn->all_channels, list) {
3167 if (pch->file.index == unit)
3168 return pch;
3169 }
3170
3171 return NULL;
3172 }
3173
3174 /*
3175 * Connect a PPP channel to a PPP interface unit.
3176 */
3177 static int
3178 ppp_connect_channel(struct channel *pch, int unit)
3179 {
3180 struct ppp *ppp;
3181 struct ppp_net *pn;
3182 int ret = -ENXIO;
3183 int hdrlen;
3184
3185 pn = ppp_pernet(pch->chan_net);
3186
3187 mutex_lock(&pn->all_ppp_mutex);
3188 ppp = ppp_find_unit(pn, unit);
3189 if (!ppp)
3190 goto out;
3191 write_lock_bh(&pch->upl);
3192 ret = -EINVAL;
3193 if (pch->ppp)
3194 goto outl;
3195
3196 ppp_lock(ppp);
3197 spin_lock_bh(&pch->downl);
3198 if (!pch->chan) {
3199 /* Don't connect unregistered channels */
3200 spin_unlock_bh(&pch->downl);
3201 ppp_unlock(ppp);
3202 ret = -ENOTCONN;
3203 goto outl;
3204 }
3205 spin_unlock_bh(&pch->downl);
3206 if (pch->file.hdrlen > ppp->file.hdrlen)
3207 ppp->file.hdrlen = pch->file.hdrlen;
3208 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
3209 if (hdrlen > ppp->dev->hard_header_len)
3210 ppp->dev->hard_header_len = hdrlen;
3211 list_add_tail(&pch->clist, &ppp->channels);
3212 ++ppp->n_channels;
3213 pch->ppp = ppp;
3214 refcount_inc(&ppp->file.refcnt);
3215 ppp_unlock(ppp);
3216 ret = 0;
3217
3218 outl:
3219 write_unlock_bh(&pch->upl);
3220 out:
3221 mutex_unlock(&pn->all_ppp_mutex);
3222 return ret;
3223 }
3224
3225 /*
3226 * Disconnect a channel from its ppp unit.
3227 */
3228 static int
3229 ppp_disconnect_channel(struct channel *pch)
3230 {
3231 struct ppp *ppp;
3232 int err = -EINVAL;
3233
3234 write_lock_bh(&pch->upl);
3235 ppp = pch->ppp;
3236 pch->ppp = NULL;
3237 write_unlock_bh(&pch->upl);
3238 if (ppp) {
3239 /* remove it from the ppp unit's list */
3240 ppp_lock(ppp);
3241 list_del(&pch->clist);
3242 if (--ppp->n_channels == 0)
3243 wake_up_interruptible(&ppp->file.rwait);
3244 ppp_unlock(ppp);
3245 if (refcount_dec_and_test(&ppp->file.refcnt))
3246 ppp_destroy_interface(ppp);
3247 err = 0;
3248 }
3249 return err;
3250 }
3251
3252 /*
3253 * Free up the resources used by a ppp channel.
3254 */
3255 static void ppp_destroy_channel(struct channel *pch)
3256 {
3257 put_net(pch->chan_net);
3258 pch->chan_net = NULL;
3259
3260 atomic_dec(&channel_count);
3261
3262 if (!pch->file.dead) {
3263 /* "can't happen" */
3264 pr_err("ppp: destroying undead channel %p !\n", pch);
3265 return;
3266 }
3267 skb_queue_purge(&pch->file.xq);
3268 skb_queue_purge(&pch->file.rq);
3269 kfree(pch);
3270 }
3271
3272 static void __exit ppp_cleanup(void)
3273 {
3274 /* should never happen */
3275 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
3276 pr_err("PPP: removing module but units remain!\n");
3277 rtnl_link_unregister(&ppp_link_ops);
3278 unregister_chrdev(PPP_MAJOR, "ppp");
3279 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
3280 class_destroy(ppp_class);
3281 unregister_pernet_device(&ppp_net_ops);
3282 }
3283
3284 /*
3285 * Units handling. Caller must protect concurrent access
3286 * by holding all_ppp_mutex
3287 */
3288
3289 /* associate pointer with specified number */
3290 static int unit_set(struct idr *p, void *ptr, int n)
3291 {
3292 int unit;
3293
3294 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL);
3295 if (unit == -ENOSPC)
3296 unit = -EINVAL;
3297 return unit;
3298 }
3299
3300 /* get new free unit number and associate pointer with it */
3301 static int unit_get(struct idr *p, void *ptr)
3302 {
3303 return idr_alloc(p, ptr, 0, 0, GFP_KERNEL);
3304 }
3305
3306 /* put unit number back to a pool */
3307 static void unit_put(struct idr *p, int n)
3308 {
3309 idr_remove(p, n);
3310 }
3311
3312 /* get pointer associated with the number */
3313 static void *unit_find(struct idr *p, int n)
3314 {
3315 return idr_find(p, n);
3316 }
3317
3318 /* Module/initialization stuff */
3319
3320 module_init(ppp_init);
3321 module_exit(ppp_cleanup);
3322
3323 EXPORT_SYMBOL(ppp_register_net_channel);
3324 EXPORT_SYMBOL(ppp_register_channel);
3325 EXPORT_SYMBOL(ppp_unregister_channel);
3326 EXPORT_SYMBOL(ppp_channel_index);
3327 EXPORT_SYMBOL(ppp_unit_number);
3328 EXPORT_SYMBOL(ppp_dev_name);
3329 EXPORT_SYMBOL(ppp_input);
3330 EXPORT_SYMBOL(ppp_input_error);
3331 EXPORT_SYMBOL(ppp_output_wakeup);
3332 EXPORT_SYMBOL(ppp_register_compressor);
3333 EXPORT_SYMBOL(ppp_unregister_compressor);
3334 MODULE_LICENSE("GPL");
3335 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
3336 MODULE_ALIAS_RTNL_LINK("ppp");
3337 MODULE_ALIAS("devname:ppp");
Linux with added FPC-III support