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