]> git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - drivers/net/ppp/ppp_generic.c
projects / mirror_ubuntu-artful-kernel.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
selftests: timers: freq-step: fix compile error
[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 struct netlink_ext_ack *extack)
1066 {
1067 if (!data)
1068 return -EINVAL;
1069
1070 if (!data[IFLA_PPP_DEV_FD])
1071 return -EINVAL;
1072 if (nla_get_s32(data[IFLA_PPP_DEV_FD]) < 0)
1073 return -EBADF;
1074
1075 return 0;
1076 }
1077
1078 static int ppp_nl_newlink(struct net *src_net, struct net_device *dev,
1079 struct nlattr *tb[], struct nlattr *data[],
1080 struct netlink_ext_ack *extack)
1081 {
1082 struct ppp_config conf = {
1083 .unit = -1,
1084 .ifname_is_set = true,
1085 };
1086 struct file *file;
1087 int err;
1088
1089 file = fget(nla_get_s32(data[IFLA_PPP_DEV_FD]));
1090 if (!file)
1091 return -EBADF;
1092
1093 /* rtnl_lock is already held here, but ppp_create_interface() locks
1094 * ppp_mutex before holding rtnl_lock. Using mutex_trylock() avoids
1095 * possible deadlock due to lock order inversion, at the cost of
1096 * pushing the problem back to userspace.
1097 */
1098 if (!mutex_trylock(&ppp_mutex)) {
1099 err = -EBUSY;
1100 goto out;
1101 }
1102
1103 if (file->f_op != &ppp_device_fops || file->private_data) {
1104 err = -EBADF;
1105 goto out_unlock;
1106 }
1107
1108 conf.file = file;
1109
1110 /* Don't use device name generated by the rtnetlink layer when ifname
1111 * isn't specified. Let ppp_dev_configure() set the device name using
1112 * the PPP unit identifer as suffix (i.e. ppp<unit_id>). This allows
1113 * userspace to infer the device name using to the PPPIOCGUNIT ioctl.
1114 */
1115 if (!tb[IFLA_IFNAME])
1116 conf.ifname_is_set = false;
1117
1118 err = ppp_dev_configure(src_net, dev, &conf);
1119
1120 out_unlock:
1121 mutex_unlock(&ppp_mutex);
1122 out:
1123 fput(file);
1124
1125 return err;
1126 }
1127
1128 static void ppp_nl_dellink(struct net_device *dev, struct list_head *head)
1129 {
1130 unregister_netdevice_queue(dev, head);
1131 }
1132
1133 static size_t ppp_nl_get_size(const struct net_device *dev)
1134 {
1135 return 0;
1136 }
1137
1138 static int ppp_nl_fill_info(struct sk_buff *skb, const struct net_device *dev)
1139 {
1140 return 0;
1141 }
1142
1143 static struct net *ppp_nl_get_link_net(const struct net_device *dev)
1144 {
1145 struct ppp *ppp = netdev_priv(dev);
1146
1147 return ppp->ppp_net;
1148 }
1149
1150 static struct rtnl_link_ops ppp_link_ops __read_mostly = {
1151 .kind = "ppp",
1152 .maxtype = IFLA_PPP_MAX,
1153 .policy = ppp_nl_policy,
1154 .priv_size = sizeof(struct ppp),
1155 .setup = ppp_setup,
1156 .validate = ppp_nl_validate,
1157 .newlink = ppp_nl_newlink,
1158 .dellink = ppp_nl_dellink,
1159 .get_size = ppp_nl_get_size,
1160 .fill_info = ppp_nl_fill_info,
1161 .get_link_net = ppp_nl_get_link_net,
1162 };
1163
1164 #define PPP_MAJOR 108
1165
1166 /* Called at boot time if ppp is compiled into the kernel,
1167 or at module load time (from init_module) if compiled as a module. */
1168 static int __init ppp_init(void)
1169 {
1170 int err;
1171
1172 pr_info("PPP generic driver version " PPP_VERSION "\n");
1173
1174 err = register_pernet_device(&ppp_net_ops);
1175 if (err) {
1176 pr_err("failed to register PPP pernet device (%d)\n", err);
1177 goto out;
1178 }
1179
1180 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
1181 if (err) {
1182 pr_err("failed to register PPP device (%d)\n", err);
1183 goto out_net;
1184 }
1185
1186 ppp_class = class_create(THIS_MODULE, "ppp");
1187 if (IS_ERR(ppp_class)) {
1188 err = PTR_ERR(ppp_class);
1189 goto out_chrdev;
1190 }
1191
1192 err = rtnl_link_register(&ppp_link_ops);
1193 if (err) {
1194 pr_err("failed to register rtnetlink PPP handler\n");
1195 goto out_class;
1196 }
1197
1198 /* not a big deal if we fail here :-) */
1199 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
1200
1201 return 0;
1202
1203 out_class:
1204 class_destroy(ppp_class);
1205 out_chrdev:
1206 unregister_chrdev(PPP_MAJOR, "ppp");
1207 out_net:
1208 unregister_pernet_device(&ppp_net_ops);
1209 out:
1210 return err;
1211 }
1212
1213 /*
1214 * Network interface unit routines.
1215 */
1216 static netdev_tx_t
1217 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
1218 {
1219 struct ppp *ppp = netdev_priv(dev);
1220 int npi, proto;
1221 unsigned char *pp;
1222
1223 npi = ethertype_to_npindex(ntohs(skb->protocol));
1224 if (npi < 0)
1225 goto outf;
1226
1227 /* Drop, accept or reject the packet */
1228 switch (ppp->npmode[npi]) {
1229 case NPMODE_PASS:
1230 break;
1231 case NPMODE_QUEUE:
1232 /* it would be nice to have a way to tell the network
1233 system to queue this one up for later. */
1234 goto outf;
1235 case NPMODE_DROP:
1236 case NPMODE_ERROR:
1237 goto outf;
1238 }
1239
1240 /* Put the 2-byte PPP protocol number on the front,
1241 making sure there is room for the address and control fields. */
1242 if (skb_cow_head(skb, PPP_HDRLEN))
1243 goto outf;
1244
1245 pp = skb_push(skb, 2);
1246 proto = npindex_to_proto[npi];
1247 put_unaligned_be16(proto, pp);
1248
1249 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, dev_net(dev)));
1250 skb_queue_tail(&ppp->file.xq, skb);
1251 ppp_xmit_process(ppp);
1252 return NETDEV_TX_OK;
1253
1254 outf:
1255 kfree_skb(skb);
1256 ++dev->stats.tx_dropped;
1257 return NETDEV_TX_OK;
1258 }
1259
1260 static int
1261 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1262 {
1263 struct ppp *ppp = netdev_priv(dev);
1264 int err = -EFAULT;
1265 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
1266 struct ppp_stats stats;
1267 struct ppp_comp_stats cstats;
1268 char *vers;
1269
1270 switch (cmd) {
1271 case SIOCGPPPSTATS:
1272 ppp_get_stats(ppp, &stats);
1273 if (copy_to_user(addr, &stats, sizeof(stats)))
1274 break;
1275 err = 0;
1276 break;
1277
1278 case SIOCGPPPCSTATS:
1279 memset(&cstats, 0, sizeof(cstats));
1280 if (ppp->xc_state)
1281 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
1282 if (ppp->rc_state)
1283 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
1284 if (copy_to_user(addr, &cstats, sizeof(cstats)))
1285 break;
1286 err = 0;
1287 break;
1288
1289 case SIOCGPPPVER:
1290 vers = PPP_VERSION;
1291 if (copy_to_user(addr, vers, strlen(vers) + 1))
1292 break;
1293 err = 0;
1294 break;
1295
1296 default:
1297 err = -EINVAL;
1298 }
1299
1300 return err;
1301 }
1302
1303 static void
1304 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64)
1305 {
1306 struct ppp *ppp = netdev_priv(dev);
1307
1308 ppp_recv_lock(ppp);
1309 stats64->rx_packets = ppp->stats64.rx_packets;
1310 stats64->rx_bytes = ppp->stats64.rx_bytes;
1311 ppp_recv_unlock(ppp);
1312
1313 ppp_xmit_lock(ppp);
1314 stats64->tx_packets = ppp->stats64.tx_packets;
1315 stats64->tx_bytes = ppp->stats64.tx_bytes;
1316 ppp_xmit_unlock(ppp);
1317
1318 stats64->rx_errors = dev->stats.rx_errors;
1319 stats64->tx_errors = dev->stats.tx_errors;
1320 stats64->rx_dropped = dev->stats.rx_dropped;
1321 stats64->tx_dropped = dev->stats.tx_dropped;
1322 stats64->rx_length_errors = dev->stats.rx_length_errors;
1323 }
1324
1325 static int ppp_dev_init(struct net_device *dev)
1326 {
1327 netdev_lockdep_set_classes(dev);
1328 return 0;
1329 }
1330
1331 static void ppp_dev_uninit(struct net_device *dev)
1332 {
1333 struct ppp *ppp = netdev_priv(dev);
1334 struct ppp_net *pn = ppp_pernet(ppp->ppp_net);
1335
1336 ppp_lock(ppp);
1337 ppp->closing = 1;
1338 ppp_unlock(ppp);
1339
1340 mutex_lock(&pn->all_ppp_mutex);
1341 unit_put(&pn->units_idr, ppp->file.index);
1342 mutex_unlock(&pn->all_ppp_mutex);
1343
1344 ppp->owner = NULL;
1345
1346 ppp->file.dead = 1;
1347 wake_up_interruptible(&ppp->file.rwait);
1348 }
1349
1350 static const struct net_device_ops ppp_netdev_ops = {
1351 .ndo_init = ppp_dev_init,
1352 .ndo_uninit = ppp_dev_uninit,
1353 .ndo_start_xmit = ppp_start_xmit,
1354 .ndo_do_ioctl = ppp_net_ioctl,
1355 .ndo_get_stats64 = ppp_get_stats64,
1356 };
1357
1358 static struct device_type ppp_type = {
1359 .name = "ppp",
1360 };
1361
1362 static void ppp_setup(struct net_device *dev)
1363 {
1364 dev->netdev_ops = &ppp_netdev_ops;
1365 SET_NETDEV_DEVTYPE(dev, &ppp_type);
1366
1367 dev->features |= NETIF_F_LLTX;
1368
1369 dev->hard_header_len = PPP_HDRLEN;
1370 dev->mtu = PPP_MRU;
1371 dev->addr_len = 0;
1372 dev->tx_queue_len = 3;
1373 dev->type = ARPHRD_PPP;
1374 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1375 netif_keep_dst(dev);
1376 }
1377
1378 /*
1379 * Transmit-side routines.
1380 */
1381
1382 /* Called to do any work queued up on the transmit side that can now be done */
1383 static void __ppp_xmit_process(struct ppp *ppp)
1384 {
1385 struct sk_buff *skb;
1386
1387 ppp_xmit_lock(ppp);
1388 if (!ppp->closing) {
1389 ppp_push(ppp);
1390 while (!ppp->xmit_pending &&
1391 (skb = skb_dequeue(&ppp->file.xq)))
1392 ppp_send_frame(ppp, skb);
1393 /* If there's no work left to do, tell the core net
1394 code that we can accept some more. */
1395 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1396 netif_wake_queue(ppp->dev);
1397 else
1398 netif_stop_queue(ppp->dev);
1399 }
1400 ppp_xmit_unlock(ppp);
1401 }
1402
1403 static DEFINE_PER_CPU(int, ppp_xmit_recursion);
1404
1405 static void ppp_xmit_process(struct ppp *ppp)
1406 {
1407 local_bh_disable();
1408
1409 if (unlikely(__this_cpu_read(ppp_xmit_recursion)))
1410 goto err;
1411
1412 __this_cpu_inc(ppp_xmit_recursion);
1413 __ppp_xmit_process(ppp);
1414 __this_cpu_dec(ppp_xmit_recursion);
1415
1416 local_bh_enable();
1417
1418 return;
1419
1420 err:
1421 local_bh_enable();
1422
1423 if (net_ratelimit())
1424 netdev_err(ppp->dev, "recursion detected\n");
1425 }
1426
1427 static inline struct sk_buff *
1428 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1429 {
1430 struct sk_buff *new_skb;
1431 int len;
1432 int new_skb_size = ppp->dev->mtu +
1433 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1434 int compressor_skb_size = ppp->dev->mtu +
1435 ppp->xcomp->comp_extra + PPP_HDRLEN;
1436 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1437 if (!new_skb) {
1438 if (net_ratelimit())
1439 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n");
1440 return NULL;
1441 }
1442 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1443 skb_reserve(new_skb,
1444 ppp->dev->hard_header_len - PPP_HDRLEN);
1445
1446 /* compressor still expects A/C bytes in hdr */
1447 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1448 new_skb->data, skb->len + 2,
1449 compressor_skb_size);
1450 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1451 consume_skb(skb);
1452 skb = new_skb;
1453 skb_put(skb, len);
1454 skb_pull(skb, 2); /* pull off A/C bytes */
1455 } else if (len == 0) {
1456 /* didn't compress, or CCP not up yet */
1457 consume_skb(new_skb);
1458 new_skb = skb;
1459 } else {
1460 /*
1461 * (len < 0)
1462 * MPPE requires that we do not send unencrypted
1463 * frames. The compressor will return -1 if we
1464 * should drop the frame. We cannot simply test
1465 * the compress_proto because MPPE and MPPC share
1466 * the same number.
1467 */
1468 if (net_ratelimit())
1469 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n");
1470 kfree_skb(skb);
1471 consume_skb(new_skb);
1472 new_skb = NULL;
1473 }
1474 return new_skb;
1475 }
1476
1477 /*
1478 * Compress and send a frame.
1479 * The caller should have locked the xmit path,
1480 * and xmit_pending should be 0.
1481 */
1482 static void
1483 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1484 {
1485 int proto = PPP_PROTO(skb);
1486 struct sk_buff *new_skb;
1487 int len;
1488 unsigned char *cp;
1489
1490 if (proto < 0x8000) {
1491 #ifdef CONFIG_PPP_FILTER
1492 /* check if we should pass this packet */
1493 /* the filter instructions are constructed assuming
1494 a four-byte PPP header on each packet */
1495 *(u8 *)skb_push(skb, 2) = 1;
1496 if (ppp->pass_filter &&
1497 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
1498 if (ppp->debug & 1)
1499 netdev_printk(KERN_DEBUG, ppp->dev,
1500 "PPP: outbound frame "
1501 "not passed\n");
1502 kfree_skb(skb);
1503 return;
1504 }
1505 /* if this packet passes the active filter, record the time */
1506 if (!(ppp->active_filter &&
1507 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
1508 ppp->last_xmit = jiffies;
1509 skb_pull(skb, 2);
1510 #else
1511 /* for data packets, record the time */
1512 ppp->last_xmit = jiffies;
1513 #endif /* CONFIG_PPP_FILTER */
1514 }
1515
1516 ++ppp->stats64.tx_packets;
1517 ppp->stats64.tx_bytes += skb->len - 2;
1518
1519 switch (proto) {
1520 case PPP_IP:
1521 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1522 break;
1523 /* try to do VJ TCP header compression */
1524 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1525 GFP_ATOMIC);
1526 if (!new_skb) {
1527 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n");
1528 goto drop;
1529 }
1530 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1531 cp = skb->data + 2;
1532 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1533 new_skb->data + 2, &cp,
1534 !(ppp->flags & SC_NO_TCP_CCID));
1535 if (cp == skb->data + 2) {
1536 /* didn't compress */
1537 consume_skb(new_skb);
1538 } else {
1539 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1540 proto = PPP_VJC_COMP;
1541 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1542 } else {
1543 proto = PPP_VJC_UNCOMP;
1544 cp[0] = skb->data[2];
1545 }
1546 consume_skb(skb);
1547 skb = new_skb;
1548 cp = skb_put(skb, len + 2);
1549 cp[0] = 0;
1550 cp[1] = proto;
1551 }
1552 break;
1553
1554 case PPP_CCP:
1555 /* peek at outbound CCP frames */
1556 ppp_ccp_peek(ppp, skb, 0);
1557 break;
1558 }
1559
1560 /* try to do packet compression */
1561 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state &&
1562 proto != PPP_LCP && proto != PPP_CCP) {
1563 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1564 if (net_ratelimit())
1565 netdev_err(ppp->dev,
1566 "ppp: compression required but "
1567 "down - pkt dropped.\n");
1568 goto drop;
1569 }
1570 skb = pad_compress_skb(ppp, skb);
1571 if (!skb)
1572 goto drop;
1573 }
1574
1575 /*
1576 * If we are waiting for traffic (demand dialling),
1577 * queue it up for pppd to receive.
1578 */
1579 if (ppp->flags & SC_LOOP_TRAFFIC) {
1580 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1581 goto drop;
1582 skb_queue_tail(&ppp->file.rq, skb);
1583 wake_up_interruptible(&ppp->file.rwait);
1584 return;
1585 }
1586
1587 ppp->xmit_pending = skb;
1588 ppp_push(ppp);
1589 return;
1590
1591 drop:
1592 kfree_skb(skb);
1593 ++ppp->dev->stats.tx_errors;
1594 }
1595
1596 /*
1597 * Try to send the frame in xmit_pending.
1598 * The caller should have the xmit path locked.
1599 */
1600 static void
1601 ppp_push(struct ppp *ppp)
1602 {
1603 struct list_head *list;
1604 struct channel *pch;
1605 struct sk_buff *skb = ppp->xmit_pending;
1606
1607 if (!skb)
1608 return;
1609
1610 list = &ppp->channels;
1611 if (list_empty(list)) {
1612 /* nowhere to send the packet, just drop it */
1613 ppp->xmit_pending = NULL;
1614 kfree_skb(skb);
1615 return;
1616 }
1617
1618 if ((ppp->flags & SC_MULTILINK) == 0) {
1619 /* not doing multilink: send it down the first channel */
1620 list = list->next;
1621 pch = list_entry(list, struct channel, clist);
1622
1623 spin_lock(&pch->downl);
1624 if (pch->chan) {
1625 if (pch->chan->ops->start_xmit(pch->chan, skb))
1626 ppp->xmit_pending = NULL;
1627 } else {
1628 /* channel got unregistered */
1629 kfree_skb(skb);
1630 ppp->xmit_pending = NULL;
1631 }
1632 spin_unlock(&pch->downl);
1633 return;
1634 }
1635
1636 #ifdef CONFIG_PPP_MULTILINK
1637 /* Multilink: fragment the packet over as many links
1638 as can take the packet at the moment. */
1639 if (!ppp_mp_explode(ppp, skb))
1640 return;
1641 #endif /* CONFIG_PPP_MULTILINK */
1642
1643 ppp->xmit_pending = NULL;
1644 kfree_skb(skb);
1645 }
1646
1647 #ifdef CONFIG_PPP_MULTILINK
1648 static bool mp_protocol_compress __read_mostly = true;
1649 module_param(mp_protocol_compress, bool, S_IRUGO | S_IWUSR);
1650 MODULE_PARM_DESC(mp_protocol_compress,
1651 "compress protocol id in multilink fragments");
1652
1653 /*
1654 * Divide a packet to be transmitted into fragments and
1655 * send them out the individual links.
1656 */
1657 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1658 {
1659 int len, totlen;
1660 int i, bits, hdrlen, mtu;
1661 int flen;
1662 int navail, nfree, nzero;
1663 int nbigger;
1664 int totspeed;
1665 int totfree;
1666 unsigned char *p, *q;
1667 struct list_head *list;
1668 struct channel *pch;
1669 struct sk_buff *frag;
1670 struct ppp_channel *chan;
1671
1672 totspeed = 0; /*total bitrate of the bundle*/
1673 nfree = 0; /* # channels which have no packet already queued */
1674 navail = 0; /* total # of usable channels (not deregistered) */
1675 nzero = 0; /* number of channels with zero speed associated*/
1676 totfree = 0; /*total # of channels available and
1677 *having no queued packets before
1678 *starting the fragmentation*/
1679
1680 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1681 i = 0;
1682 list_for_each_entry(pch, &ppp->channels, clist) {
1683 if (pch->chan) {
1684 pch->avail = 1;
1685 navail++;
1686 pch->speed = pch->chan->speed;
1687 } else {
1688 pch->avail = 0;
1689 }
1690 if (pch->avail) {
1691 if (skb_queue_empty(&pch->file.xq) ||
1692 !pch->had_frag) {
1693 if (pch->speed == 0)
1694 nzero++;
1695 else
1696 totspeed += pch->speed;
1697
1698 pch->avail = 2;
1699 ++nfree;
1700 ++totfree;
1701 }
1702 if (!pch->had_frag && i < ppp->nxchan)
1703 ppp->nxchan = i;
1704 }
1705 ++i;
1706 }
1707 /*
1708 * Don't start sending this packet unless at least half of
1709 * the channels are free. This gives much better TCP
1710 * performance if we have a lot of channels.
1711 */
1712 if (nfree == 0 || nfree < navail / 2)
1713 return 0; /* can't take now, leave it in xmit_pending */
1714
1715 /* Do protocol field compression */
1716 p = skb->data;
1717 len = skb->len;
1718 if (*p == 0 && mp_protocol_compress) {
1719 ++p;
1720 --len;
1721 }
1722
1723 totlen = len;
1724 nbigger = len % nfree;
1725
1726 /* skip to the channel after the one we last used
1727 and start at that one */
1728 list = &ppp->channels;
1729 for (i = 0; i < ppp->nxchan; ++i) {
1730 list = list->next;
1731 if (list == &ppp->channels) {
1732 i = 0;
1733 break;
1734 }
1735 }
1736
1737 /* create a fragment for each channel */
1738 bits = B;
1739 while (len > 0) {
1740 list = list->next;
1741 if (list == &ppp->channels) {
1742 i = 0;
1743 continue;
1744 }
1745 pch = list_entry(list, struct channel, clist);
1746 ++i;
1747 if (!pch->avail)
1748 continue;
1749
1750 /*
1751 * Skip this channel if it has a fragment pending already and
1752 * we haven't given a fragment to all of the free channels.
1753 */
1754 if (pch->avail == 1) {
1755 if (nfree > 0)
1756 continue;
1757 } else {
1758 pch->avail = 1;
1759 }
1760
1761 /* check the channel's mtu and whether it is still attached. */
1762 spin_lock(&pch->downl);
1763 if (pch->chan == NULL) {
1764 /* can't use this channel, it's being deregistered */
1765 if (pch->speed == 0)
1766 nzero--;
1767 else
1768 totspeed -= pch->speed;
1769
1770 spin_unlock(&pch->downl);
1771 pch->avail = 0;
1772 totlen = len;
1773 totfree--;
1774 nfree--;
1775 if (--navail == 0)
1776 break;
1777 continue;
1778 }
1779
1780 /*
1781 *if the channel speed is not set divide
1782 *the packet evenly among the free channels;
1783 *otherwise divide it according to the speed
1784 *of the channel we are going to transmit on
1785 */
1786 flen = len;
1787 if (nfree > 0) {
1788 if (pch->speed == 0) {
1789 flen = len/nfree;
1790 if (nbigger > 0) {
1791 flen++;
1792 nbigger--;
1793 }
1794 } else {
1795 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
1796 ((totspeed*totfree)/pch->speed)) - hdrlen;
1797 if (nbigger > 0) {
1798 flen += ((totfree - nzero)*pch->speed)/totspeed;
1799 nbigger -= ((totfree - nzero)*pch->speed)/
1800 totspeed;
1801 }
1802 }
1803 nfree--;
1804 }
1805
1806 /*
1807 *check if we are on the last channel or
1808 *we exceded the length of the data to
1809 *fragment
1810 */
1811 if ((nfree <= 0) || (flen > len))
1812 flen = len;
1813 /*
1814 *it is not worth to tx on slow channels:
1815 *in that case from the resulting flen according to the
1816 *above formula will be equal or less than zero.
1817 *Skip the channel in this case
1818 */
1819 if (flen <= 0) {
1820 pch->avail = 2;
1821 spin_unlock(&pch->downl);
1822 continue;
1823 }
1824
1825 /*
1826 * hdrlen includes the 2-byte PPP protocol field, but the
1827 * MTU counts only the payload excluding the protocol field.
1828 * (RFC1661 Section 2)
1829 */
1830 mtu = pch->chan->mtu - (hdrlen - 2);
1831 if (mtu < 4)
1832 mtu = 4;
1833 if (flen > mtu)
1834 flen = mtu;
1835 if (flen == len)
1836 bits |= E;
1837 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1838 if (!frag)
1839 goto noskb;
1840 q = skb_put(frag, flen + hdrlen);
1841
1842 /* make the MP header */
1843 put_unaligned_be16(PPP_MP, q);
1844 if (ppp->flags & SC_MP_XSHORTSEQ) {
1845 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1846 q[3] = ppp->nxseq;
1847 } else {
1848 q[2] = bits;
1849 q[3] = ppp->nxseq >> 16;
1850 q[4] = ppp->nxseq >> 8;
1851 q[5] = ppp->nxseq;
1852 }
1853
1854 memcpy(q + hdrlen, p, flen);
1855
1856 /* try to send it down the channel */
1857 chan = pch->chan;
1858 if (!skb_queue_empty(&pch->file.xq) ||
1859 !chan->ops->start_xmit(chan, frag))
1860 skb_queue_tail(&pch->file.xq, frag);
1861 pch->had_frag = 1;
1862 p += flen;
1863 len -= flen;
1864 ++ppp->nxseq;
1865 bits = 0;
1866 spin_unlock(&pch->downl);
1867 }
1868 ppp->nxchan = i;
1869
1870 return 1;
1871
1872 noskb:
1873 spin_unlock(&pch->downl);
1874 if (ppp->debug & 1)
1875 netdev_err(ppp->dev, "PPP: no memory (fragment)\n");
1876 ++ppp->dev->stats.tx_errors;
1877 ++ppp->nxseq;
1878 return 1; /* abandon the frame */
1879 }
1880 #endif /* CONFIG_PPP_MULTILINK */
1881
1882 /* Try to send data out on a channel */
1883 static void __ppp_channel_push(struct channel *pch)
1884 {
1885 struct sk_buff *skb;
1886 struct ppp *ppp;
1887
1888 spin_lock(&pch->downl);
1889 if (pch->chan) {
1890 while (!skb_queue_empty(&pch->file.xq)) {
1891 skb = skb_dequeue(&pch->file.xq);
1892 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1893 /* put the packet back and try again later */
1894 skb_queue_head(&pch->file.xq, skb);
1895 break;
1896 }
1897 }
1898 } else {
1899 /* channel got deregistered */
1900 skb_queue_purge(&pch->file.xq);
1901 }
1902 spin_unlock(&pch->downl);
1903 /* see if there is anything from the attached unit to be sent */
1904 if (skb_queue_empty(&pch->file.xq)) {
1905 read_lock(&pch->upl);
1906 ppp = pch->ppp;
1907 if (ppp)
1908 __ppp_xmit_process(ppp);
1909 read_unlock(&pch->upl);
1910 }
1911 }
1912
1913 static void ppp_channel_push(struct channel *pch)
1914 {
1915 local_bh_disable();
1916
1917 __this_cpu_inc(ppp_xmit_recursion);
1918 __ppp_channel_push(pch);
1919 __this_cpu_dec(ppp_xmit_recursion);
1920
1921 local_bh_enable();
1922 }
1923
1924 /*
1925 * Receive-side routines.
1926 */
1927
1928 struct ppp_mp_skb_parm {
1929 u32 sequence;
1930 u8 BEbits;
1931 };
1932 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb))
1933
1934 static inline void
1935 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1936 {
1937 ppp_recv_lock(ppp);
1938 if (!ppp->closing)
1939 ppp_receive_frame(ppp, skb, pch);
1940 else
1941 kfree_skb(skb);
1942 ppp_recv_unlock(ppp);
1943 }
1944
1945 void
1946 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1947 {
1948 struct channel *pch = chan->ppp;
1949 int proto;
1950
1951 if (!pch) {
1952 kfree_skb(skb);
1953 return;
1954 }
1955
1956 read_lock_bh(&pch->upl);
1957 if (!pskb_may_pull(skb, 2)) {
1958 kfree_skb(skb);
1959 if (pch->ppp) {
1960 ++pch->ppp->dev->stats.rx_length_errors;
1961 ppp_receive_error(pch->ppp);
1962 }
1963 goto done;
1964 }
1965
1966 proto = PPP_PROTO(skb);
1967 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1968 /* put it on the channel queue */
1969 skb_queue_tail(&pch->file.rq, skb);
1970 /* drop old frames if queue too long */
1971 while (pch->file.rq.qlen > PPP_MAX_RQLEN &&
1972 (skb = skb_dequeue(&pch->file.rq)))
1973 kfree_skb(skb);
1974 wake_up_interruptible(&pch->file.rwait);
1975 } else {
1976 ppp_do_recv(pch->ppp, skb, pch);
1977 }
1978
1979 done:
1980 read_unlock_bh(&pch->upl);
1981 }
1982
1983 /* Put a 0-length skb in the receive queue as an error indication */
1984 void
1985 ppp_input_error(struct ppp_channel *chan, int code)
1986 {
1987 struct channel *pch = chan->ppp;
1988 struct sk_buff *skb;
1989
1990 if (!pch)
1991 return;
1992
1993 read_lock_bh(&pch->upl);
1994 if (pch->ppp) {
1995 skb = alloc_skb(0, GFP_ATOMIC);
1996 if (skb) {
1997 skb->len = 0; /* probably unnecessary */
1998 skb->cb[0] = code;
1999 ppp_do_recv(pch->ppp, skb, pch);
2000 }
2001 }
2002 read_unlock_bh(&pch->upl);
2003 }
2004
2005 /*
2006 * We come in here to process a received frame.
2007 * The receive side of the ppp unit is locked.
2008 */
2009 static void
2010 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
2011 {
2012 /* note: a 0-length skb is used as an error indication */
2013 if (skb->len > 0) {
2014 skb_checksum_complete_unset(skb);
2015 #ifdef CONFIG_PPP_MULTILINK
2016 /* XXX do channel-level decompression here */
2017 if (PPP_PROTO(skb) == PPP_MP)
2018 ppp_receive_mp_frame(ppp, skb, pch);
2019 else
2020 #endif /* CONFIG_PPP_MULTILINK */
2021 ppp_receive_nonmp_frame(ppp, skb);
2022 } else {
2023 kfree_skb(skb);
2024 ppp_receive_error(ppp);
2025 }
2026 }
2027
2028 static void
2029 ppp_receive_error(struct ppp *ppp)
2030 {
2031 ++ppp->dev->stats.rx_errors;
2032 if (ppp->vj)
2033 slhc_toss(ppp->vj);
2034 }
2035
2036 static void
2037 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
2038 {
2039 struct sk_buff *ns;
2040 int proto, len, npi;
2041
2042 /*
2043 * Decompress the frame, if compressed.
2044 * Note that some decompressors need to see uncompressed frames
2045 * that come in as well as compressed frames.
2046 */
2047 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) &&
2048 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
2049 skb = ppp_decompress_frame(ppp, skb);
2050
2051 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
2052 goto err;
2053
2054 proto = PPP_PROTO(skb);
2055 switch (proto) {
2056 case PPP_VJC_COMP:
2057 /* decompress VJ compressed packets */
2058 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
2059 goto err;
2060
2061 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
2062 /* copy to a new sk_buff with more tailroom */
2063 ns = dev_alloc_skb(skb->len + 128);
2064 if (!ns) {
2065 netdev_err(ppp->dev, "PPP: no memory "
2066 "(VJ decomp)\n");
2067 goto err;
2068 }
2069 skb_reserve(ns, 2);
2070 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
2071 consume_skb(skb);
2072 skb = ns;
2073 }
2074 else
2075 skb->ip_summed = CHECKSUM_NONE;
2076
2077 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
2078 if (len <= 0) {
2079 netdev_printk(KERN_DEBUG, ppp->dev,
2080 "PPP: VJ decompression error\n");
2081 goto err;
2082 }
2083 len += 2;
2084 if (len > skb->len)
2085 skb_put(skb, len - skb->len);
2086 else if (len < skb->len)
2087 skb_trim(skb, len);
2088 proto = PPP_IP;
2089 break;
2090
2091 case PPP_VJC_UNCOMP:
2092 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
2093 goto err;
2094
2095 /* Until we fix the decompressor need to make sure
2096 * data portion is linear.
2097 */
2098 if (!pskb_may_pull(skb, skb->len))
2099 goto err;
2100
2101 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
2102 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n");
2103 goto err;
2104 }
2105 proto = PPP_IP;
2106 break;
2107
2108 case PPP_CCP:
2109 ppp_ccp_peek(ppp, skb, 1);
2110 break;
2111 }
2112
2113 ++ppp->stats64.rx_packets;
2114 ppp->stats64.rx_bytes += skb->len - 2;
2115
2116 npi = proto_to_npindex(proto);
2117 if (npi < 0) {
2118 /* control or unknown frame - pass it to pppd */
2119 skb_queue_tail(&ppp->file.rq, skb);
2120 /* limit queue length by dropping old frames */
2121 while (ppp->file.rq.qlen > PPP_MAX_RQLEN &&
2122 (skb = skb_dequeue(&ppp->file.rq)))
2123 kfree_skb(skb);
2124 /* wake up any process polling or blocking on read */
2125 wake_up_interruptible(&ppp->file.rwait);
2126
2127 } else {
2128 /* network protocol frame - give it to the kernel */
2129
2130 #ifdef CONFIG_PPP_FILTER
2131 /* check if the packet passes the pass and active filters */
2132 /* the filter instructions are constructed assuming
2133 a four-byte PPP header on each packet */
2134 if (ppp->pass_filter || ppp->active_filter) {
2135 if (skb_unclone(skb, GFP_ATOMIC))
2136 goto err;
2137
2138 *(u8 *)skb_push(skb, 2) = 0;
2139 if (ppp->pass_filter &&
2140 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
2141 if (ppp->debug & 1)
2142 netdev_printk(KERN_DEBUG, ppp->dev,
2143 "PPP: inbound frame "
2144 "not passed\n");
2145 kfree_skb(skb);
2146 return;
2147 }
2148 if (!(ppp->active_filter &&
2149 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
2150 ppp->last_recv = jiffies;
2151 __skb_pull(skb, 2);
2152 } else
2153 #endif /* CONFIG_PPP_FILTER */
2154 ppp->last_recv = jiffies;
2155
2156 if ((ppp->dev->flags & IFF_UP) == 0 ||
2157 ppp->npmode[npi] != NPMODE_PASS) {
2158 kfree_skb(skb);
2159 } else {
2160 /* chop off protocol */
2161 skb_pull_rcsum(skb, 2);
2162 skb->dev = ppp->dev;
2163 skb->protocol = htons(npindex_to_ethertype[npi]);
2164 skb_reset_mac_header(skb);
2165 skb_scrub_packet(skb, !net_eq(ppp->ppp_net,
2166 dev_net(ppp->dev)));
2167 netif_rx(skb);
2168 }
2169 }
2170 return;
2171
2172 err:
2173 kfree_skb(skb);
2174 ppp_receive_error(ppp);
2175 }
2176
2177 static struct sk_buff *
2178 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
2179 {
2180 int proto = PPP_PROTO(skb);
2181 struct sk_buff *ns;
2182 int len;
2183
2184 /* Until we fix all the decompressor's need to make sure
2185 * data portion is linear.
2186 */
2187 if (!pskb_may_pull(skb, skb->len))
2188 goto err;
2189
2190 if (proto == PPP_COMP) {
2191 int obuff_size;
2192
2193 switch(ppp->rcomp->compress_proto) {
2194 case CI_MPPE:
2195 obuff_size = ppp->mru + PPP_HDRLEN + 1;
2196 break;
2197 default:
2198 obuff_size = ppp->mru + PPP_HDRLEN;
2199 break;
2200 }
2201
2202 ns = dev_alloc_skb(obuff_size);
2203 if (!ns) {
2204 netdev_err(ppp->dev, "ppp_decompress_frame: "
2205 "no memory\n");
2206 goto err;
2207 }
2208 /* the decompressor still expects the A/C bytes in the hdr */
2209 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
2210 skb->len + 2, ns->data, obuff_size);
2211 if (len < 0) {
2212 /* Pass the compressed frame to pppd as an
2213 error indication. */
2214 if (len == DECOMP_FATALERROR)
2215 ppp->rstate |= SC_DC_FERROR;
2216 kfree_skb(ns);
2217 goto err;
2218 }
2219
2220 consume_skb(skb);
2221 skb = ns;
2222 skb_put(skb, len);
2223 skb_pull(skb, 2); /* pull off the A/C bytes */
2224
2225 } else {
2226 /* Uncompressed frame - pass to decompressor so it
2227 can update its dictionary if necessary. */
2228 if (ppp->rcomp->incomp)
2229 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
2230 skb->len + 2);
2231 }
2232
2233 return skb;
2234
2235 err:
2236 ppp->rstate |= SC_DC_ERROR;
2237 ppp_receive_error(ppp);
2238 return skb;
2239 }
2240
2241 #ifdef CONFIG_PPP_MULTILINK
2242 /*
2243 * Receive a multilink frame.
2244 * We put it on the reconstruction queue and then pull off
2245 * as many completed frames as we can.
2246 */
2247 static void
2248 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
2249 {
2250 u32 mask, seq;
2251 struct channel *ch;
2252 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
2253
2254 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
2255 goto err; /* no good, throw it away */
2256
2257 /* Decode sequence number and begin/end bits */
2258 if (ppp->flags & SC_MP_SHORTSEQ) {
2259 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
2260 mask = 0xfff;
2261 } else {
2262 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
2263 mask = 0xffffff;
2264 }
2265 PPP_MP_CB(skb)->BEbits = skb->data[2];
2266 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
2267
2268 /*
2269 * Do protocol ID decompression on the first fragment of each packet.
2270 */
2271 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1))
2272 *(u8 *)skb_push(skb, 1) = 0;
2273
2274 /*
2275 * Expand sequence number to 32 bits, making it as close
2276 * as possible to ppp->minseq.
2277 */
2278 seq |= ppp->minseq & ~mask;
2279 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
2280 seq += mask + 1;
2281 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
2282 seq -= mask + 1; /* should never happen */
2283 PPP_MP_CB(skb)->sequence = seq;
2284 pch->lastseq = seq;
2285
2286 /*
2287 * If this packet comes before the next one we were expecting,
2288 * drop it.
2289 */
2290 if (seq_before(seq, ppp->nextseq)) {
2291 kfree_skb(skb);
2292 ++ppp->dev->stats.rx_dropped;
2293 ppp_receive_error(ppp);
2294 return;
2295 }
2296
2297 /*
2298 * Reevaluate minseq, the minimum over all channels of the
2299 * last sequence number received on each channel. Because of
2300 * the increasing sequence number rule, we know that any fragment
2301 * before `minseq' which hasn't arrived is never going to arrive.
2302 * The list of channels can't change because we have the receive
2303 * side of the ppp unit locked.
2304 */
2305 list_for_each_entry(ch, &ppp->channels, clist) {
2306 if (seq_before(ch->lastseq, seq))
2307 seq = ch->lastseq;
2308 }
2309 if (seq_before(ppp->minseq, seq))
2310 ppp->minseq = seq;
2311
2312 /* Put the fragment on the reconstruction queue */
2313 ppp_mp_insert(ppp, skb);
2314
2315 /* If the queue is getting long, don't wait any longer for packets
2316 before the start of the queue. */
2317 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
2318 struct sk_buff *mskb = skb_peek(&ppp->mrq);
2319 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence))
2320 ppp->minseq = PPP_MP_CB(mskb)->sequence;
2321 }
2322
2323 /* Pull completed packets off the queue and receive them. */
2324 while ((skb = ppp_mp_reconstruct(ppp))) {
2325 if (pskb_may_pull(skb, 2))
2326 ppp_receive_nonmp_frame(ppp, skb);
2327 else {
2328 ++ppp->dev->stats.rx_length_errors;
2329 kfree_skb(skb);
2330 ppp_receive_error(ppp);
2331 }
2332 }
2333
2334 return;
2335
2336 err:
2337 kfree_skb(skb);
2338 ppp_receive_error(ppp);
2339 }
2340
2341 /*
2342 * Insert a fragment on the MP reconstruction queue.
2343 * The queue is ordered by increasing sequence number.
2344 */
2345 static void
2346 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
2347 {
2348 struct sk_buff *p;
2349 struct sk_buff_head *list = &ppp->mrq;
2350 u32 seq = PPP_MP_CB(skb)->sequence;
2351
2352 /* N.B. we don't need to lock the list lock because we have the
2353 ppp unit receive-side lock. */
2354 skb_queue_walk(list, p) {
2355 if (seq_before(seq, PPP_MP_CB(p)->sequence))
2356 break;
2357 }
2358 __skb_queue_before(list, p, skb);
2359 }
2360
2361 /*
2362 * Reconstruct a packet from the MP fragment queue.
2363 * We go through increasing sequence numbers until we find a
2364 * complete packet, or we get to the sequence number for a fragment
2365 * which hasn't arrived but might still do so.
2366 */
2367 static struct sk_buff *
2368 ppp_mp_reconstruct(struct ppp *ppp)
2369 {
2370 u32 seq = ppp->nextseq;
2371 u32 minseq = ppp->minseq;
2372 struct sk_buff_head *list = &ppp->mrq;
2373 struct sk_buff *p, *tmp;
2374 struct sk_buff *head, *tail;
2375 struct sk_buff *skb = NULL;
2376 int lost = 0, len = 0;
2377
2378 if (ppp->mrru == 0) /* do nothing until mrru is set */
2379 return NULL;
2380 head = list->next;
2381 tail = NULL;
2382 skb_queue_walk_safe(list, p, tmp) {
2383 again:
2384 if (seq_before(PPP_MP_CB(p)->sequence, seq)) {
2385 /* this can't happen, anyway ignore the skb */
2386 netdev_err(ppp->dev, "ppp_mp_reconstruct bad "
2387 "seq %u < %u\n",
2388 PPP_MP_CB(p)->sequence, seq);
2389 __skb_unlink(p, list);
2390 kfree_skb(p);
2391 continue;
2392 }
2393 if (PPP_MP_CB(p)->sequence != seq) {
2394 u32 oldseq;
2395 /* Fragment `seq' is missing. If it is after
2396 minseq, it might arrive later, so stop here. */
2397 if (seq_after(seq, minseq))
2398 break;
2399 /* Fragment `seq' is lost, keep going. */
2400 lost = 1;
2401 oldseq = seq;
2402 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)?
2403 minseq + 1: PPP_MP_CB(p)->sequence;
2404
2405 if (ppp->debug & 1)
2406 netdev_printk(KERN_DEBUG, ppp->dev,
2407 "lost frag %u..%u\n",
2408 oldseq, seq-1);
2409
2410 goto again;
2411 }
2412
2413 /*
2414 * At this point we know that all the fragments from
2415 * ppp->nextseq to seq are either present or lost.
2416 * Also, there are no complete packets in the queue
2417 * that have no missing fragments and end before this
2418 * fragment.
2419 */
2420
2421 /* B bit set indicates this fragment starts a packet */
2422 if (PPP_MP_CB(p)->BEbits & B) {
2423 head = p;
2424 lost = 0;
2425 len = 0;
2426 }
2427
2428 len += p->len;
2429
2430 /* Got a complete packet yet? */
2431 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) &&
2432 (PPP_MP_CB(head)->BEbits & B)) {
2433 if (len > ppp->mrru + 2) {
2434 ++ppp->dev->stats.rx_length_errors;
2435 netdev_printk(KERN_DEBUG, ppp->dev,
2436 "PPP: reconstructed packet"
2437 " is too long (%d)\n", len);
2438 } else {
2439 tail = p;
2440 break;
2441 }
2442 ppp->nextseq = seq + 1;
2443 }
2444
2445 /*
2446 * If this is the ending fragment of a packet,
2447 * and we haven't found a complete valid packet yet,
2448 * we can discard up to and including this fragment.
2449 */
2450 if (PPP_MP_CB(p)->BEbits & E) {
2451 struct sk_buff *tmp2;
2452
2453 skb_queue_reverse_walk_from_safe(list, p, tmp2) {
2454 if (ppp->debug & 1)
2455 netdev_printk(KERN_DEBUG, ppp->dev,
2456 "discarding frag %u\n",
2457 PPP_MP_CB(p)->sequence);
2458 __skb_unlink(p, list);
2459 kfree_skb(p);
2460 }
2461 head = skb_peek(list);
2462 if (!head)
2463 break;
2464 }
2465 ++seq;
2466 }
2467
2468 /* If we have a complete packet, copy it all into one skb. */
2469 if (tail != NULL) {
2470 /* If we have discarded any fragments,
2471 signal a receive error. */
2472 if (PPP_MP_CB(head)->sequence != ppp->nextseq) {
2473 skb_queue_walk_safe(list, p, tmp) {
2474 if (p == head)
2475 break;
2476 if (ppp->debug & 1)
2477 netdev_printk(KERN_DEBUG, ppp->dev,
2478 "discarding frag %u\n",
2479 PPP_MP_CB(p)->sequence);
2480 __skb_unlink(p, list);
2481 kfree_skb(p);
2482 }
2483
2484 if (ppp->debug & 1)
2485 netdev_printk(KERN_DEBUG, ppp->dev,
2486 " missed pkts %u..%u\n",
2487 ppp->nextseq,
2488 PPP_MP_CB(head)->sequence-1);
2489 ++ppp->dev->stats.rx_dropped;
2490 ppp_receive_error(ppp);
2491 }
2492
2493 skb = head;
2494 if (head != tail) {
2495 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list;
2496 p = skb_queue_next(list, head);
2497 __skb_unlink(skb, list);
2498 skb_queue_walk_from_safe(list, p, tmp) {
2499 __skb_unlink(p, list);
2500 *fragpp = p;
2501 p->next = NULL;
2502 fragpp = &p->next;
2503
2504 skb->len += p->len;
2505 skb->data_len += p->len;
2506 skb->truesize += p->truesize;
2507
2508 if (p == tail)
2509 break;
2510 }
2511 } else {
2512 __skb_unlink(skb, list);
2513 }
2514
2515 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1;
2516 }
2517
2518 return skb;
2519 }
2520 #endif /* CONFIG_PPP_MULTILINK */
2521
2522 /*
2523 * Channel interface.
2524 */
2525
2526 /* Create a new, unattached ppp channel. */
2527 int ppp_register_channel(struct ppp_channel *chan)
2528 {
2529 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2530 }
2531
2532 /* Create a new, unattached ppp channel for specified net. */
2533 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
2534 {
2535 struct channel *pch;
2536 struct ppp_net *pn;
2537
2538 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2539 if (!pch)
2540 return -ENOMEM;
2541
2542 pn = ppp_pernet(net);
2543
2544 pch->ppp = NULL;
2545 pch->chan = chan;
2546 pch->chan_net = get_net(net);
2547 chan->ppp = pch;
2548 init_ppp_file(&pch->file, CHANNEL);
2549 pch->file.hdrlen = chan->hdrlen;
2550 #ifdef CONFIG_PPP_MULTILINK
2551 pch->lastseq = -1;
2552 #endif /* CONFIG_PPP_MULTILINK */
2553 init_rwsem(&pch->chan_sem);
2554 spin_lock_init(&pch->downl);
2555 rwlock_init(&pch->upl);
2556
2557 spin_lock_bh(&pn->all_channels_lock);
2558 pch->file.index = ++pn->last_channel_index;
2559 list_add(&pch->list, &pn->new_channels);
2560 atomic_inc(&channel_count);
2561 spin_unlock_bh(&pn->all_channels_lock);
2562
2563 return 0;
2564 }
2565
2566 /*
2567 * Return the index of a channel.
2568 */
2569 int ppp_channel_index(struct ppp_channel *chan)
2570 {
2571 struct channel *pch = chan->ppp;
2572
2573 if (pch)
2574 return pch->file.index;
2575 return -1;
2576 }
2577
2578 /*
2579 * Return the PPP unit number to which a channel is connected.
2580 */
2581 int ppp_unit_number(struct ppp_channel *chan)
2582 {
2583 struct channel *pch = chan->ppp;
2584 int unit = -1;
2585
2586 if (pch) {
2587 read_lock_bh(&pch->upl);
2588 if (pch->ppp)
2589 unit = pch->ppp->file.index;
2590 read_unlock_bh(&pch->upl);
2591 }
2592 return unit;
2593 }
2594
2595 /*
2596 * Return the PPP device interface name of a channel.
2597 */
2598 char *ppp_dev_name(struct ppp_channel *chan)
2599 {
2600 struct channel *pch = chan->ppp;
2601 char *name = NULL;
2602
2603 if (pch) {
2604 read_lock_bh(&pch->upl);
2605 if (pch->ppp && pch->ppp->dev)
2606 name = pch->ppp->dev->name;
2607 read_unlock_bh(&pch->upl);
2608 }
2609 return name;
2610 }
2611
2612
2613 /*
2614 * Disconnect a channel from the generic layer.
2615 * This must be called in process context.
2616 */
2617 void
2618 ppp_unregister_channel(struct ppp_channel *chan)
2619 {
2620 struct channel *pch = chan->ppp;
2621 struct ppp_net *pn;
2622
2623 if (!pch)
2624 return; /* should never happen */
2625
2626 chan->ppp = NULL;
2627
2628 /*
2629 * This ensures that we have returned from any calls into the
2630 * the channel's start_xmit or ioctl routine before we proceed.
2631 */
2632 down_write(&pch->chan_sem);
2633 spin_lock_bh(&pch->downl);
2634 pch->chan = NULL;
2635 spin_unlock_bh(&pch->downl);
2636 up_write(&pch->chan_sem);
2637 ppp_disconnect_channel(pch);
2638
2639 pn = ppp_pernet(pch->chan_net);
2640 spin_lock_bh(&pn->all_channels_lock);
2641 list_del(&pch->list);
2642 spin_unlock_bh(&pn->all_channels_lock);
2643
2644 pch->file.dead = 1;
2645 wake_up_interruptible(&pch->file.rwait);
2646 if (atomic_dec_and_test(&pch->file.refcnt))
2647 ppp_destroy_channel(pch);
2648 }
2649
2650 /*
2651 * Callback from a channel when it can accept more to transmit.
2652 * This should be called at BH/softirq level, not interrupt level.
2653 */
2654 void
2655 ppp_output_wakeup(struct ppp_channel *chan)
2656 {
2657 struct channel *pch = chan->ppp;
2658
2659 if (!pch)
2660 return;
2661 ppp_channel_push(pch);
2662 }
2663
2664 /*
2665 * Compression control.
2666 */
2667
2668 /* Process the PPPIOCSCOMPRESS ioctl. */
2669 static int
2670 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2671 {
2672 int err;
2673 struct compressor *cp, *ocomp;
2674 struct ppp_option_data data;
2675 void *state, *ostate;
2676 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2677
2678 err = -EFAULT;
2679 if (copy_from_user(&data, (void __user *) arg, sizeof(data)))
2680 goto out;
2681 if (data.length > CCP_MAX_OPTION_LENGTH)
2682 goto out;
2683 if (copy_from_user(ccp_option, (void __user *) data.ptr, data.length))
2684 goto out;
2685
2686 err = -EINVAL;
2687 if (data.length < 2 || ccp_option[1] < 2 || ccp_option[1] > data.length)
2688 goto out;
2689
2690 cp = try_then_request_module(
2691 find_compressor(ccp_option[0]),
2692 "ppp-compress-%d", ccp_option[0]);
2693 if (!cp)
2694 goto out;
2695
2696 err = -ENOBUFS;
2697 if (data.transmit) {
2698 state = cp->comp_alloc(ccp_option, data.length);
2699 if (state) {
2700 ppp_xmit_lock(ppp);
2701 ppp->xstate &= ~SC_COMP_RUN;
2702 ocomp = ppp->xcomp;
2703 ostate = ppp->xc_state;
2704 ppp->xcomp = cp;
2705 ppp->xc_state = state;
2706 ppp_xmit_unlock(ppp);
2707 if (ostate) {
2708 ocomp->comp_free(ostate);
2709 module_put(ocomp->owner);
2710 }
2711 err = 0;
2712 } else
2713 module_put(cp->owner);
2714
2715 } else {
2716 state = cp->decomp_alloc(ccp_option, data.length);
2717 if (state) {
2718 ppp_recv_lock(ppp);
2719 ppp->rstate &= ~SC_DECOMP_RUN;
2720 ocomp = ppp->rcomp;
2721 ostate = ppp->rc_state;
2722 ppp->rcomp = cp;
2723 ppp->rc_state = state;
2724 ppp_recv_unlock(ppp);
2725 if (ostate) {
2726 ocomp->decomp_free(ostate);
2727 module_put(ocomp->owner);
2728 }
2729 err = 0;
2730 } else
2731 module_put(cp->owner);
2732 }
2733
2734 out:
2735 return err;
2736 }
2737
2738 /*
2739 * Look at a CCP packet and update our state accordingly.
2740 * We assume the caller has the xmit or recv path locked.
2741 */
2742 static void
2743 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2744 {
2745 unsigned char *dp;
2746 int len;
2747
2748 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2749 return; /* no header */
2750 dp = skb->data + 2;
2751
2752 switch (CCP_CODE(dp)) {
2753 case CCP_CONFREQ:
2754
2755 /* A ConfReq starts negotiation of compression
2756 * in one direction of transmission,
2757 * and hence brings it down...but which way?
2758 *
2759 * Remember:
2760 * A ConfReq indicates what the sender would like to receive
2761 */
2762 if(inbound)
2763 /* He is proposing what I should send */
2764 ppp->xstate &= ~SC_COMP_RUN;
2765 else
2766 /* I am proposing to what he should send */
2767 ppp->rstate &= ~SC_DECOMP_RUN;
2768
2769 break;
2770
2771 case CCP_TERMREQ:
2772 case CCP_TERMACK:
2773 /*
2774 * CCP is going down, both directions of transmission
2775 */
2776 ppp->rstate &= ~SC_DECOMP_RUN;
2777 ppp->xstate &= ~SC_COMP_RUN;
2778 break;
2779
2780 case CCP_CONFACK:
2781 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2782 break;
2783 len = CCP_LENGTH(dp);
2784 if (!pskb_may_pull(skb, len + 2))
2785 return; /* too short */
2786 dp += CCP_HDRLEN;
2787 len -= CCP_HDRLEN;
2788 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2789 break;
2790 if (inbound) {
2791 /* we will start receiving compressed packets */
2792 if (!ppp->rc_state)
2793 break;
2794 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2795 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2796 ppp->rstate |= SC_DECOMP_RUN;
2797 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2798 }
2799 } else {
2800 /* we will soon start sending compressed packets */
2801 if (!ppp->xc_state)
2802 break;
2803 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2804 ppp->file.index, 0, ppp->debug))
2805 ppp->xstate |= SC_COMP_RUN;
2806 }
2807 break;
2808
2809 case CCP_RESETACK:
2810 /* reset the [de]compressor */
2811 if ((ppp->flags & SC_CCP_UP) == 0)
2812 break;
2813 if (inbound) {
2814 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2815 ppp->rcomp->decomp_reset(ppp->rc_state);
2816 ppp->rstate &= ~SC_DC_ERROR;
2817 }
2818 } else {
2819 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2820 ppp->xcomp->comp_reset(ppp->xc_state);
2821 }
2822 break;
2823 }
2824 }
2825
2826 /* Free up compression resources. */
2827 static void
2828 ppp_ccp_closed(struct ppp *ppp)
2829 {
2830 void *xstate, *rstate;
2831 struct compressor *xcomp, *rcomp;
2832
2833 ppp_lock(ppp);
2834 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2835 ppp->xstate = 0;
2836 xcomp = ppp->xcomp;
2837 xstate = ppp->xc_state;
2838 ppp->xc_state = NULL;
2839 ppp->rstate = 0;
2840 rcomp = ppp->rcomp;
2841 rstate = ppp->rc_state;
2842 ppp->rc_state = NULL;
2843 ppp_unlock(ppp);
2844
2845 if (xstate) {
2846 xcomp->comp_free(xstate);
2847 module_put(xcomp->owner);
2848 }
2849 if (rstate) {
2850 rcomp->decomp_free(rstate);
2851 module_put(rcomp->owner);
2852 }
2853 }
2854
2855 /* List of compressors. */
2856 static LIST_HEAD(compressor_list);
2857 static DEFINE_SPINLOCK(compressor_list_lock);
2858
2859 struct compressor_entry {
2860 struct list_head list;
2861 struct compressor *comp;
2862 };
2863
2864 static struct compressor_entry *
2865 find_comp_entry(int proto)
2866 {
2867 struct compressor_entry *ce;
2868
2869 list_for_each_entry(ce, &compressor_list, list) {
2870 if (ce->comp->compress_proto == proto)
2871 return ce;
2872 }
2873 return NULL;
2874 }
2875
2876 /* Register a compressor */
2877 int
2878 ppp_register_compressor(struct compressor *cp)
2879 {
2880 struct compressor_entry *ce;
2881 int ret;
2882 spin_lock(&compressor_list_lock);
2883 ret = -EEXIST;
2884 if (find_comp_entry(cp->compress_proto))
2885 goto out;
2886 ret = -ENOMEM;
2887 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2888 if (!ce)
2889 goto out;
2890 ret = 0;
2891 ce->comp = cp;
2892 list_add(&ce->list, &compressor_list);
2893 out:
2894 spin_unlock(&compressor_list_lock);
2895 return ret;
2896 }
2897
2898 /* Unregister a compressor */
2899 void
2900 ppp_unregister_compressor(struct compressor *cp)
2901 {
2902 struct compressor_entry *ce;
2903
2904 spin_lock(&compressor_list_lock);
2905 ce = find_comp_entry(cp->compress_proto);
2906 if (ce && ce->comp == cp) {
2907 list_del(&ce->list);
2908 kfree(ce);
2909 }
2910 spin_unlock(&compressor_list_lock);
2911 }
2912
2913 /* Find a compressor. */
2914 static struct compressor *
2915 find_compressor(int type)
2916 {
2917 struct compressor_entry *ce;
2918 struct compressor *cp = NULL;
2919
2920 spin_lock(&compressor_list_lock);
2921 ce = find_comp_entry(type);
2922 if (ce) {
2923 cp = ce->comp;
2924 if (!try_module_get(cp->owner))
2925 cp = NULL;
2926 }
2927 spin_unlock(&compressor_list_lock);
2928 return cp;
2929 }
2930
2931 /*
2932 * Miscelleneous stuff.
2933 */
2934
2935 static void
2936 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2937 {
2938 struct slcompress *vj = ppp->vj;
2939
2940 memset(st, 0, sizeof(*st));
2941 st->p.ppp_ipackets = ppp->stats64.rx_packets;
2942 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2943 st->p.ppp_ibytes = ppp->stats64.rx_bytes;
2944 st->p.ppp_opackets = ppp->stats64.tx_packets;
2945 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2946 st->p.ppp_obytes = ppp->stats64.tx_bytes;
2947 if (!vj)
2948 return;
2949 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2950 st->vj.vjs_compressed = vj->sls_o_compressed;
2951 st->vj.vjs_searches = vj->sls_o_searches;
2952 st->vj.vjs_misses = vj->sls_o_misses;
2953 st->vj.vjs_errorin = vj->sls_i_error;
2954 st->vj.vjs_tossed = vj->sls_i_tossed;
2955 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2956 st->vj.vjs_compressedin = vj->sls_i_compressed;
2957 }
2958
2959 /*
2960 * Stuff for handling the lists of ppp units and channels
2961 * and for initialization.
2962 */
2963
2964 /*
2965 * Create a new ppp interface unit. Fails if it can't allocate memory
2966 * or if there is already a unit with the requested number.
2967 * unit == -1 means allocate a new number.
2968 */
2969 static int ppp_create_interface(struct net *net, struct file *file, int *unit)
2970 {
2971 struct ppp_config conf = {
2972 .file = file,
2973 .unit = *unit,
2974 .ifname_is_set = false,
2975 };
2976 struct net_device *dev;
2977 struct ppp *ppp;
2978 int err;
2979
2980 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_ENUM, ppp_setup);
2981 if (!dev) {
2982 err = -ENOMEM;
2983 goto err;
2984 }
2985 dev_net_set(dev, net);
2986 dev->rtnl_link_ops = &ppp_link_ops;
2987
2988 rtnl_lock();
2989
2990 err = ppp_dev_configure(net, dev, &conf);
2991 if (err < 0)
2992 goto err_dev;
2993 ppp = netdev_priv(dev);
2994 *unit = ppp->file.index;
2995
2996 rtnl_unlock();
2997
2998 return 0;
2999
3000 err_dev:
3001 rtnl_unlock();
3002 free_netdev(dev);
3003 err:
3004 return err;
3005 }
3006
3007 /*
3008 * Initialize a ppp_file structure.
3009 */
3010 static void
3011 init_ppp_file(struct ppp_file *pf, int kind)
3012 {
3013 pf->kind = kind;
3014 skb_queue_head_init(&pf->xq);
3015 skb_queue_head_init(&pf->rq);
3016 atomic_set(&pf->refcnt, 1);
3017 init_waitqueue_head(&pf->rwait);
3018 }
3019
3020 /*
3021 * Free the memory used by a ppp unit. This is only called once
3022 * there are no channels connected to the unit and no file structs
3023 * that reference the unit.
3024 */
3025 static void ppp_destroy_interface(struct ppp *ppp)
3026 {
3027 atomic_dec(&ppp_unit_count);
3028
3029 if (!ppp->file.dead || ppp->n_channels) {
3030 /* "can't happen" */
3031 netdev_err(ppp->dev, "ppp: destroying ppp struct %p "
3032 "but dead=%d n_channels=%d !\n",
3033 ppp, ppp->file.dead, ppp->n_channels);
3034 return;
3035 }
3036
3037 ppp_ccp_closed(ppp);
3038 if (ppp->vj) {
3039 slhc_free(ppp->vj);
3040 ppp->vj = NULL;
3041 }
3042 skb_queue_purge(&ppp->file.xq);
3043 skb_queue_purge(&ppp->file.rq);
3044 #ifdef CONFIG_PPP_MULTILINK
3045 skb_queue_purge(&ppp->mrq);
3046 #endif /* CONFIG_PPP_MULTILINK */
3047 #ifdef CONFIG_PPP_FILTER
3048 if (ppp->pass_filter) {
3049 bpf_prog_destroy(ppp->pass_filter);
3050 ppp->pass_filter = NULL;
3051 }
3052
3053 if (ppp->active_filter) {
3054 bpf_prog_destroy(ppp->active_filter);
3055 ppp->active_filter = NULL;
3056 }
3057 #endif /* CONFIG_PPP_FILTER */
3058
3059 kfree_skb(ppp->xmit_pending);
3060
3061 free_netdev(ppp->dev);
3062 }
3063
3064 /*
3065 * Locate an existing ppp unit.
3066 * The caller should have locked the all_ppp_mutex.
3067 */
3068 static struct ppp *
3069 ppp_find_unit(struct ppp_net *pn, int unit)
3070 {
3071 return unit_find(&pn->units_idr, unit);
3072 }
3073
3074 /*
3075 * Locate an existing ppp channel.
3076 * The caller should have locked the all_channels_lock.
3077 * First we look in the new_channels list, then in the
3078 * all_channels list. If found in the new_channels list,
3079 * we move it to the all_channels list. This is for speed
3080 * when we have a lot of channels in use.
3081 */
3082 static struct channel *
3083 ppp_find_channel(struct ppp_net *pn, int unit)
3084 {
3085 struct channel *pch;
3086
3087 list_for_each_entry(pch, &pn->new_channels, list) {
3088 if (pch->file.index == unit) {
3089 list_move(&pch->list, &pn->all_channels);
3090 return pch;
3091 }
3092 }
3093
3094 list_for_each_entry(pch, &pn->all_channels, list) {
3095 if (pch->file.index == unit)
3096 return pch;
3097 }
3098
3099 return NULL;
3100 }
3101
3102 /*
3103 * Connect a PPP channel to a PPP interface unit.
3104 */
3105 static int
3106 ppp_connect_channel(struct channel *pch, int unit)
3107 {
3108 struct ppp *ppp;
3109 struct ppp_net *pn;
3110 int ret = -ENXIO;
3111 int hdrlen;
3112
3113 pn = ppp_pernet(pch->chan_net);
3114
3115 mutex_lock(&pn->all_ppp_mutex);
3116 ppp = ppp_find_unit(pn, unit);
3117 if (!ppp)
3118 goto out;
3119 write_lock_bh(&pch->upl);
3120 ret = -EINVAL;
3121 if (pch->ppp)
3122 goto outl;
3123
3124 ppp_lock(ppp);
3125 if (pch->file.hdrlen > ppp->file.hdrlen)
3126 ppp->file.hdrlen = pch->file.hdrlen;
3127 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
3128 if (hdrlen > ppp->dev->hard_header_len)
3129 ppp->dev->hard_header_len = hdrlen;
3130 list_add_tail(&pch->clist, &ppp->channels);
3131 ++ppp->n_channels;
3132 pch->ppp = ppp;
3133 atomic_inc(&ppp->file.refcnt);
3134 ppp_unlock(ppp);
3135 ret = 0;
3136
3137 outl:
3138 write_unlock_bh(&pch->upl);
3139 out:
3140 mutex_unlock(&pn->all_ppp_mutex);
3141 return ret;
3142 }
3143
3144 /*
3145 * Disconnect a channel from its ppp unit.
3146 */
3147 static int
3148 ppp_disconnect_channel(struct channel *pch)
3149 {
3150 struct ppp *ppp;
3151 int err = -EINVAL;
3152
3153 write_lock_bh(&pch->upl);
3154 ppp = pch->ppp;
3155 pch->ppp = NULL;
3156 write_unlock_bh(&pch->upl);
3157 if (ppp) {
3158 /* remove it from the ppp unit's list */
3159 ppp_lock(ppp);
3160 list_del(&pch->clist);
3161 if (--ppp->n_channels == 0)
3162 wake_up_interruptible(&ppp->file.rwait);
3163 ppp_unlock(ppp);
3164 if (atomic_dec_and_test(&ppp->file.refcnt))
3165 ppp_destroy_interface(ppp);
3166 err = 0;
3167 }
3168 return err;
3169 }
3170
3171 /*
3172 * Free up the resources used by a ppp channel.
3173 */
3174 static void ppp_destroy_channel(struct channel *pch)
3175 {
3176 put_net(pch->chan_net);
3177 pch->chan_net = NULL;
3178
3179 atomic_dec(&channel_count);
3180
3181 if (!pch->file.dead) {
3182 /* "can't happen" */
3183 pr_err("ppp: destroying undead channel %p !\n", pch);
3184 return;
3185 }
3186 skb_queue_purge(&pch->file.xq);
3187 skb_queue_purge(&pch->file.rq);
3188 kfree(pch);
3189 }
3190
3191 static void __exit ppp_cleanup(void)
3192 {
3193 /* should never happen */
3194 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
3195 pr_err("PPP: removing module but units remain!\n");
3196 rtnl_link_unregister(&ppp_link_ops);
3197 unregister_chrdev(PPP_MAJOR, "ppp");
3198 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
3199 class_destroy(ppp_class);
3200 unregister_pernet_device(&ppp_net_ops);
3201 }
3202
3203 /*
3204 * Units handling. Caller must protect concurrent access
3205 * by holding all_ppp_mutex
3206 */
3207
3208 /* associate pointer with specified number */
3209 static int unit_set(struct idr *p, void *ptr, int n)
3210 {
3211 int unit;
3212
3213 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL);
3214 if (unit == -ENOSPC)
3215 unit = -EINVAL;
3216 return unit;
3217 }
3218
3219 /* get new free unit number and associate pointer with it */
3220 static int unit_get(struct idr *p, void *ptr)
3221 {
3222 return idr_alloc(p, ptr, 0, 0, GFP_KERNEL);
3223 }
3224
3225 /* put unit number back to a pool */
3226 static void unit_put(struct idr *p, int n)
3227 {
3228 idr_remove(p, n);
3229 }
3230
3231 /* get pointer associated with the number */
3232 static void *unit_find(struct idr *p, int n)
3233 {
3234 return idr_find(p, n);
3235 }
3236
3237 /* Module/initialization stuff */
3238
3239 module_init(ppp_init);
3240 module_exit(ppp_cleanup);
3241
3242 EXPORT_SYMBOL(ppp_register_net_channel);
3243 EXPORT_SYMBOL(ppp_register_channel);
3244 EXPORT_SYMBOL(ppp_unregister_channel);
3245 EXPORT_SYMBOL(ppp_channel_index);
3246 EXPORT_SYMBOL(ppp_unit_number);
3247 EXPORT_SYMBOL(ppp_dev_name);
3248 EXPORT_SYMBOL(ppp_input);
3249 EXPORT_SYMBOL(ppp_input_error);
3250 EXPORT_SYMBOL(ppp_output_wakeup);
3251 EXPORT_SYMBOL(ppp_register_compressor);
3252 EXPORT_SYMBOL(ppp_unregister_compressor);
3253 MODULE_LICENSE("GPL");
3254 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
3255 MODULE_ALIAS_RTNL_LINK("ppp");
3256 MODULE_ALIAS("devname:ppp");
Ubuntu Artful kernel mirror