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[mirror_ubuntu-eoan-kernel.git] / drivers / net / ppp / ppp_generic.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Generic PPP layer for Linux.
4 *
5 * Copyright 1999-2002 Paul Mackerras.
6 *
7 * The generic PPP layer handles the PPP network interfaces, the
8 * /dev/ppp device, packet and VJ compression, and multilink.
9 * It talks to PPP `channels' via the interface defined in
10 * include/linux/ppp_channel.h. Channels provide the basic means for
11 * sending and receiving PPP frames on some kind of communications
12 * channel.
13 *
14 * Part of the code in this driver was inspired by the old async-only
15 * PPP driver, written by Michael Callahan and Al Longyear, and
16 * subsequently hacked by Paul Mackerras.
17 *
18 * ==FILEVERSION 20041108==
19 */
20
21 #include <linux/module.h>
22 #include <linux/kernel.h>
23 #include <linux/sched/signal.h>
24 #include <linux/kmod.h>
25 #include <linux/init.h>
26 #include <linux/list.h>
27 #include <linux/idr.h>
28 #include <linux/netdevice.h>
29 #include <linux/poll.h>
30 #include <linux/ppp_defs.h>
31 #include <linux/filter.h>
32 #include <linux/ppp-ioctl.h>
33 #include <linux/ppp_channel.h>
34 #include <linux/ppp-comp.h>
35 #include <linux/skbuff.h>
36 #include <linux/rtnetlink.h>
37 #include <linux/if_arp.h>
38 #include <linux/ip.h>
39 #include <linux/tcp.h>
40 #include <linux/spinlock.h>
41 #include <linux/rwsem.h>
42 #include <linux/stddef.h>
43 #include <linux/device.h>
44 #include <linux/mutex.h>
45 #include <linux/slab.h>
46 #include <linux/file.h>
47 #include <asm/unaligned.h>
48 #include <net/slhc_vj.h>
49 #include <linux/atomic.h>
50 #include <linux/refcount.h>
51
52 #include <linux/nsproxy.h>
53 #include <net/net_namespace.h>
54 #include <net/netns/generic.h>
55
56 #define PPP_VERSION "2.4.2"
57
58 /*
59 * Network protocols we support.
60 */
61 #define NP_IP 0 /* Internet Protocol V4 */
62 #define NP_IPV6 1 /* Internet Protocol V6 */
63 #define NP_IPX 2 /* IPX protocol */
64 #define NP_AT 3 /* Appletalk protocol */
65 #define NP_MPLS_UC 4 /* MPLS unicast */
66 #define NP_MPLS_MC 5 /* MPLS multicast */
67 #define NUM_NP 6 /* Number of NPs. */
68
69 #define MPHDRLEN 6 /* multilink protocol header length */
70 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */
71
72 /*
73 * An instance of /dev/ppp can be associated with either a ppp
74 * interface unit or a ppp channel. In both cases, file->private_data
75 * points to one of these.
76 */
77 struct ppp_file {
78 enum {
79 INTERFACE=1, CHANNEL
80 } kind;
81 struct sk_buff_head xq; /* pppd transmit queue */
82 struct sk_buff_head rq; /* receive queue for pppd */
83 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */
84 refcount_t refcnt; /* # refs (incl /dev/ppp attached) */
85 int hdrlen; /* space to leave for headers */
86 int index; /* interface unit / channel number */
87 int dead; /* unit/channel has been shut down */
88 };
89
90 #define PF_TO_X(pf, X) container_of(pf, X, file)
91
92 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
93 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
94
95 /*
96 * Data structure to hold primary network stats for which
97 * we want to use 64 bit storage. Other network stats
98 * are stored in dev->stats of the ppp strucute.
99 */
100 struct ppp_link_stats {
101 u64 rx_packets;
102 u64 tx_packets;
103 u64 rx_bytes;
104 u64 tx_bytes;
105 };
106
107 /*
108 * Data structure describing one ppp unit.
109 * A ppp unit corresponds to a ppp network interface device
110 * and represents a multilink bundle.
111 * It can have 0 or more ppp channels connected to it.
112 */
113 struct ppp {
114 struct ppp_file file; /* stuff for read/write/poll 0 */
115 struct file *owner; /* file that owns this unit 48 */
116 struct list_head channels; /* list of attached channels 4c */
117 int n_channels; /* how many channels are attached 54 */
118 spinlock_t rlock; /* lock for receive side 58 */
119 spinlock_t wlock; /* lock for transmit side 5c */
120 int __percpu *xmit_recursion; /* xmit recursion detect */
121 int mru; /* max receive unit 60 */
122 unsigned int flags; /* control bits 64 */
123 unsigned int xstate; /* transmit state bits 68 */
124 unsigned int rstate; /* receive state bits 6c */
125 int debug; /* debug flags 70 */
126 struct slcompress *vj; /* state for VJ header compression */
127 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
128 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
129 struct compressor *xcomp; /* transmit packet compressor 8c */
130 void *xc_state; /* its internal state 90 */
131 struct compressor *rcomp; /* receive decompressor 94 */
132 void *rc_state; /* its internal state 98 */
133 unsigned long last_xmit; /* jiffies when last pkt sent 9c */
134 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
135 struct net_device *dev; /* network interface device a4 */
136 int closing; /* is device closing down? a8 */
137 #ifdef CONFIG_PPP_MULTILINK
138 int nxchan; /* next channel to send something on */
139 u32 nxseq; /* next sequence number to send */
140 int mrru; /* MP: max reconst. receive unit */
141 u32 nextseq; /* MP: seq no of next packet */
142 u32 minseq; /* MP: min of most recent seqnos */
143 struct sk_buff_head mrq; /* MP: receive reconstruction queue */
144 #endif /* CONFIG_PPP_MULTILINK */
145 #ifdef CONFIG_PPP_FILTER
146 struct bpf_prog *pass_filter; /* filter for packets to pass */
147 struct bpf_prog *active_filter; /* filter for pkts to reset idle */
148 #endif /* CONFIG_PPP_FILTER */
149 struct net *ppp_net; /* the net we belong to */
150 struct ppp_link_stats stats64; /* 64 bit network stats */
151 };
152
153 /*
154 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
155 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
156 * SC_MUST_COMP
157 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
158 * Bits in xstate: SC_COMP_RUN
159 */
160 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
161 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
162 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
163
164 /*
165 * Private data structure for each channel.
166 * This includes the data structure used for multilink.
167 */
168 struct channel {
169 struct ppp_file file; /* stuff for read/write/poll */
170 struct list_head list; /* link in all/new_channels list */
171 struct ppp_channel *chan; /* public channel data structure */
172 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
173 spinlock_t downl; /* protects `chan', file.xq dequeue */
174 struct ppp *ppp; /* ppp unit we're connected to */
175 struct net *chan_net; /* the net channel belongs to */
176 struct list_head clist; /* link in list of channels per unit */
177 rwlock_t upl; /* protects `ppp' */
178 #ifdef CONFIG_PPP_MULTILINK
179 u8 avail; /* flag used in multilink stuff */
180 u8 had_frag; /* >= 1 fragments have been sent */
181 u32 lastseq; /* MP: last sequence # received */
182 int speed; /* speed of the corresponding ppp channel*/
183 #endif /* CONFIG_PPP_MULTILINK */
184 };
185
186 struct ppp_config {
187 struct file *file;
188 s32 unit;
189 bool ifname_is_set;
190 };
191
192 /*
193 * SMP locking issues:
194 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
195 * list and the ppp.n_channels field, you need to take both locks
196 * before you modify them.
197 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
198 * channel.downl.
199 */
200
201 static DEFINE_MUTEX(ppp_mutex);
202 static atomic_t ppp_unit_count = ATOMIC_INIT(0);
203 static atomic_t channel_count = ATOMIC_INIT(0);
204
205 /* per-net private data for this module */
206 static unsigned int ppp_net_id __read_mostly;
207 struct ppp_net {
208 /* units to ppp mapping */
209 struct idr units_idr;
210
211 /*
212 * all_ppp_mutex protects the units_idr mapping.
213 * It also ensures that finding a ppp unit in the units_idr
214 * map and updating its file.refcnt field is atomic.
215 */
216 struct mutex all_ppp_mutex;
217
218 /* channels */
219 struct list_head all_channels;
220 struct list_head new_channels;
221 int last_channel_index;
222
223 /*
224 * all_channels_lock protects all_channels and
225 * last_channel_index, and the atomicity of find
226 * a channel and updating its file.refcnt field.
227 */
228 spinlock_t all_channels_lock;
229 };
230
231 /* Get the PPP protocol number from a skb */
232 #define PPP_PROTO(skb) get_unaligned_be16((skb)->data)
233
234 /* We limit the length of ppp->file.rq to this (arbitrary) value */
235 #define PPP_MAX_RQLEN 32
236
237 /*
238 * Maximum number of multilink fragments queued up.
239 * This has to be large enough to cope with the maximum latency of
240 * the slowest channel relative to the others. Strictly it should
241 * depend on the number of channels and their characteristics.
242 */
243 #define PPP_MP_MAX_QLEN 128
244
245 /* Multilink header bits. */
246 #define B 0x80 /* this fragment begins a packet */
247 #define E 0x40 /* this fragment ends a packet */
248
249 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */
250 #define seq_before(a, b) ((s32)((a) - (b)) < 0)
251 #define seq_after(a, b) ((s32)((a) - (b)) > 0)
252
253 /* Prototypes. */
254 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
255 struct file *file, unsigned int cmd, unsigned long arg);
256 static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb);
257 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
258 static void ppp_push(struct ppp *ppp);
259 static void ppp_channel_push(struct channel *pch);
260 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
261 struct channel *pch);
262 static void ppp_receive_error(struct ppp *ppp);
263 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
264 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
265 struct sk_buff *skb);
266 #ifdef CONFIG_PPP_MULTILINK
267 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
268 struct channel *pch);
269 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
270 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
271 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
272 #endif /* CONFIG_PPP_MULTILINK */
273 static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
274 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
275 static void ppp_ccp_closed(struct ppp *ppp);
276 static struct compressor *find_compressor(int type);
277 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
278 static int ppp_create_interface(struct net *net, struct file *file, int *unit);
279 static void init_ppp_file(struct ppp_file *pf, int kind);
280 static void ppp_destroy_interface(struct ppp *ppp);
281 static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit);
282 static struct channel *ppp_find_channel(struct ppp_net *pn, int unit);
283 static int ppp_connect_channel(struct channel *pch, int unit);
284 static int ppp_disconnect_channel(struct channel *pch);
285 static void ppp_destroy_channel(struct channel *pch);
286 static int unit_get(struct idr *p, void *ptr);
287 static int unit_set(struct idr *p, void *ptr, int n);
288 static void unit_put(struct idr *p, int n);
289 static void *unit_find(struct idr *p, int n);
290 static void ppp_setup(struct net_device *dev);
291
292 static const struct net_device_ops ppp_netdev_ops;
293
294 static struct class *ppp_class;
295
296 /* per net-namespace data */
297 static inline struct ppp_net *ppp_pernet(struct net *net)
298 {
299 BUG_ON(!net);
300
301 return net_generic(net, ppp_net_id);
302 }
303
304 /* Translates a PPP protocol number to a NP index (NP == network protocol) */
305 static inline int proto_to_npindex(int proto)
306 {
307 switch (proto) {
308 case PPP_IP:
309 return NP_IP;
310 case PPP_IPV6:
311 return NP_IPV6;
312 case PPP_IPX:
313 return NP_IPX;
314 case PPP_AT:
315 return NP_AT;
316 case PPP_MPLS_UC:
317 return NP_MPLS_UC;
318 case PPP_MPLS_MC:
319 return NP_MPLS_MC;
320 }
321 return -EINVAL;
322 }
323
324 /* Translates an NP index into a PPP protocol number */
325 static const int npindex_to_proto[NUM_NP] = {
326 PPP_IP,
327 PPP_IPV6,
328 PPP_IPX,
329 PPP_AT,
330 PPP_MPLS_UC,
331 PPP_MPLS_MC,
332 };
333
334 /* Translates an ethertype into an NP index */
335 static inline int ethertype_to_npindex(int ethertype)
336 {
337 switch (ethertype) {
338 case ETH_P_IP:
339 return NP_IP;
340 case ETH_P_IPV6:
341 return NP_IPV6;
342 case ETH_P_IPX:
343 return NP_IPX;
344 case ETH_P_PPPTALK:
345 case ETH_P_ATALK:
346 return NP_AT;
347 case ETH_P_MPLS_UC:
348 return NP_MPLS_UC;
349 case ETH_P_MPLS_MC:
350 return NP_MPLS_MC;
351 }
352 return -1;
353 }
354
355 /* Translates an NP index into an ethertype */
356 static const int npindex_to_ethertype[NUM_NP] = {
357 ETH_P_IP,
358 ETH_P_IPV6,
359 ETH_P_IPX,
360 ETH_P_PPPTALK,
361 ETH_P_MPLS_UC,
362 ETH_P_MPLS_MC,
363 };
364
365 /*
366 * Locking shorthand.
367 */
368 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
369 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
370 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
371 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
372 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
373 ppp_recv_lock(ppp); } while (0)
374 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
375 ppp_xmit_unlock(ppp); } while (0)
376
377 /*
378 * /dev/ppp device routines.
379 * The /dev/ppp device is used by pppd to control the ppp unit.
380 * It supports the read, write, ioctl and poll functions.
381 * Open instances of /dev/ppp can be in one of three states:
382 * unattached, attached to a ppp unit, or attached to a ppp channel.
383 */
384 static int ppp_open(struct inode *inode, struct file *file)
385 {
386 /*
387 * This could (should?) be enforced by the permissions on /dev/ppp.
388 */
389 if (!ns_capable(file->f_cred->user_ns, CAP_NET_ADMIN))
390 return -EPERM;
391 return 0;
392 }
393
394 static int ppp_release(struct inode *unused, struct file *file)
395 {
396 struct ppp_file *pf = file->private_data;
397 struct ppp *ppp;
398
399 if (pf) {
400 file->private_data = NULL;
401 if (pf->kind == INTERFACE) {
402 ppp = PF_TO_PPP(pf);
403 rtnl_lock();
404 if (file == ppp->owner)
405 unregister_netdevice(ppp->dev);
406 rtnl_unlock();
407 }
408 if (refcount_dec_and_test(&pf->refcnt)) {
409 switch (pf->kind) {
410 case INTERFACE:
411 ppp_destroy_interface(PF_TO_PPP(pf));
412 break;
413 case CHANNEL:
414 ppp_destroy_channel(PF_TO_CHANNEL(pf));
415 break;
416 }
417 }
418 }
419 return 0;
420 }
421
422 static ssize_t ppp_read(struct file *file, char __user *buf,
423 size_t count, loff_t *ppos)
424 {
425 struct ppp_file *pf = file->private_data;
426 DECLARE_WAITQUEUE(wait, current);
427 ssize_t ret;
428 struct sk_buff *skb = NULL;
429 struct iovec iov;
430 struct iov_iter to;
431
432 ret = count;
433
434 if (!pf)
435 return -ENXIO;
436 add_wait_queue(&pf->rwait, &wait);
437 for (;;) {
438 set_current_state(TASK_INTERRUPTIBLE);
439 skb = skb_dequeue(&pf->rq);
440 if (skb)
441 break;
442 ret = 0;
443 if (pf->dead)
444 break;
445 if (pf->kind == INTERFACE) {
446 /*
447 * Return 0 (EOF) on an interface that has no
448 * channels connected, unless it is looping
449 * network traffic (demand mode).
450 */
451 struct ppp *ppp = PF_TO_PPP(pf);
452
453 ppp_recv_lock(ppp);
454 if (ppp->n_channels == 0 &&
455 (ppp->flags & SC_LOOP_TRAFFIC) == 0) {
456 ppp_recv_unlock(ppp);
457 break;
458 }
459 ppp_recv_unlock(ppp);
460 }
461 ret = -EAGAIN;
462 if (file->f_flags & O_NONBLOCK)
463 break;
464 ret = -ERESTARTSYS;
465 if (signal_pending(current))
466 break;
467 schedule();
468 }
469 set_current_state(TASK_RUNNING);
470 remove_wait_queue(&pf->rwait, &wait);
471
472 if (!skb)
473 goto out;
474
475 ret = -EOVERFLOW;
476 if (skb->len > count)
477 goto outf;
478 ret = -EFAULT;
479 iov.iov_base = buf;
480 iov.iov_len = count;
481 iov_iter_init(&to, READ, &iov, 1, count);
482 if (skb_copy_datagram_iter(skb, 0, &to, skb->len))
483 goto outf;
484 ret = skb->len;
485
486 outf:
487 kfree_skb(skb);
488 out:
489 return ret;
490 }
491
492 static ssize_t ppp_write(struct file *file, const char __user *buf,
493 size_t count, loff_t *ppos)
494 {
495 struct ppp_file *pf = file->private_data;
496 struct sk_buff *skb;
497 ssize_t ret;
498
499 if (!pf)
500 return -ENXIO;
501 ret = -ENOMEM;
502 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
503 if (!skb)
504 goto out;
505 skb_reserve(skb, pf->hdrlen);
506 ret = -EFAULT;
507 if (copy_from_user(skb_put(skb, count), buf, count)) {
508 kfree_skb(skb);
509 goto out;
510 }
511
512 switch (pf->kind) {
513 case INTERFACE:
514 ppp_xmit_process(PF_TO_PPP(pf), skb);
515 break;
516 case CHANNEL:
517 skb_queue_tail(&pf->xq, skb);
518 ppp_channel_push(PF_TO_CHANNEL(pf));
519 break;
520 }
521
522 ret = count;
523
524 out:
525 return ret;
526 }
527
528 /* No kernel lock - fine */
529 static __poll_t ppp_poll(struct file *file, poll_table *wait)
530 {
531 struct ppp_file *pf = file->private_data;
532 __poll_t mask;
533
534 if (!pf)
535 return 0;
536 poll_wait(file, &pf->rwait, wait);
537 mask = EPOLLOUT | EPOLLWRNORM;
538 if (skb_peek(&pf->rq))
539 mask |= EPOLLIN | EPOLLRDNORM;
540 if (pf->dead)
541 mask |= EPOLLHUP;
542 else if (pf->kind == INTERFACE) {
543 /* see comment in ppp_read */
544 struct ppp *ppp = PF_TO_PPP(pf);
545
546 ppp_recv_lock(ppp);
547 if (ppp->n_channels == 0 &&
548 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
549 mask |= EPOLLIN | EPOLLRDNORM;
550 ppp_recv_unlock(ppp);
551 }
552
553 return mask;
554 }
555
556 #ifdef CONFIG_PPP_FILTER
557 static int get_filter(void __user *arg, struct sock_filter **p)
558 {
559 struct sock_fprog uprog;
560 struct sock_filter *code = NULL;
561 int len;
562
563 if (copy_from_user(&uprog, arg, sizeof(uprog)))
564 return -EFAULT;
565
566 if (!uprog.len) {
567 *p = NULL;
568 return 0;
569 }
570
571 len = uprog.len * sizeof(struct sock_filter);
572 code = memdup_user(uprog.filter, len);
573 if (IS_ERR(code))
574 return PTR_ERR(code);
575
576 *p = code;
577 return uprog.len;
578 }
579 #endif /* CONFIG_PPP_FILTER */
580
581 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
582 {
583 struct ppp_file *pf;
584 struct ppp *ppp;
585 int err = -EFAULT, val, val2, i;
586 struct ppp_idle idle;
587 struct npioctl npi;
588 int unit, cflags;
589 struct slcompress *vj;
590 void __user *argp = (void __user *)arg;
591 int __user *p = argp;
592
593 mutex_lock(&ppp_mutex);
594
595 pf = file->private_data;
596 if (!pf) {
597 err = ppp_unattached_ioctl(current->nsproxy->net_ns,
598 pf, file, cmd, arg);
599 goto out;
600 }
601
602 if (cmd == PPPIOCDETACH) {
603 /*
604 * PPPIOCDETACH is no longer supported as it was heavily broken,
605 * and is only known to have been used by pppd older than
606 * ppp-2.4.2 (released November 2003).
607 */
608 pr_warn_once("%s (%d) used obsolete PPPIOCDETACH ioctl\n",
609 current->comm, current->pid);
610 err = -EINVAL;
611 goto out;
612 }
613
614 if (pf->kind == CHANNEL) {
615 struct channel *pch;
616 struct ppp_channel *chan;
617
618 pch = PF_TO_CHANNEL(pf);
619
620 switch (cmd) {
621 case PPPIOCCONNECT:
622 if (get_user(unit, p))
623 break;
624 err = ppp_connect_channel(pch, unit);
625 break;
626
627 case PPPIOCDISCONN:
628 err = ppp_disconnect_channel(pch);
629 break;
630
631 default:
632 down_read(&pch->chan_sem);
633 chan = pch->chan;
634 err = -ENOTTY;
635 if (chan && chan->ops->ioctl)
636 err = chan->ops->ioctl(chan, cmd, arg);
637 up_read(&pch->chan_sem);
638 }
639 goto out;
640 }
641
642 if (pf->kind != INTERFACE) {
643 /* can't happen */
644 pr_err("PPP: not interface or channel??\n");
645 err = -EINVAL;
646 goto out;
647 }
648
649 ppp = PF_TO_PPP(pf);
650 switch (cmd) {
651 case PPPIOCSMRU:
652 if (get_user(val, p))
653 break;
654 ppp->mru = val;
655 err = 0;
656 break;
657
658 case PPPIOCSFLAGS:
659 if (get_user(val, p))
660 break;
661 ppp_lock(ppp);
662 cflags = ppp->flags & ~val;
663 #ifdef CONFIG_PPP_MULTILINK
664 if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK))
665 ppp->nextseq = 0;
666 #endif
667 ppp->flags = val & SC_FLAG_BITS;
668 ppp_unlock(ppp);
669 if (cflags & SC_CCP_OPEN)
670 ppp_ccp_closed(ppp);
671 err = 0;
672 break;
673
674 case PPPIOCGFLAGS:
675 val = ppp->flags | ppp->xstate | ppp->rstate;
676 if (put_user(val, p))
677 break;
678 err = 0;
679 break;
680
681 case PPPIOCSCOMPRESS:
682 err = ppp_set_compress(ppp, arg);
683 break;
684
685 case PPPIOCGUNIT:
686 if (put_user(ppp->file.index, p))
687 break;
688 err = 0;
689 break;
690
691 case PPPIOCSDEBUG:
692 if (get_user(val, p))
693 break;
694 ppp->debug = val;
695 err = 0;
696 break;
697
698 case PPPIOCGDEBUG:
699 if (put_user(ppp->debug, p))
700 break;
701 err = 0;
702 break;
703
704 case PPPIOCGIDLE:
705 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
706 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
707 if (copy_to_user(argp, &idle, sizeof(idle)))
708 break;
709 err = 0;
710 break;
711
712 case PPPIOCSMAXCID:
713 if (get_user(val, p))
714 break;
715 val2 = 15;
716 if ((val >> 16) != 0) {
717 val2 = val >> 16;
718 val &= 0xffff;
719 }
720 vj = slhc_init(val2+1, val+1);
721 if (IS_ERR(vj)) {
722 err = PTR_ERR(vj);
723 break;
724 }
725 ppp_lock(ppp);
726 if (ppp->vj)
727 slhc_free(ppp->vj);
728 ppp->vj = vj;
729 ppp_unlock(ppp);
730 err = 0;
731 break;
732
733 case PPPIOCGNPMODE:
734 case PPPIOCSNPMODE:
735 if (copy_from_user(&npi, argp, sizeof(npi)))
736 break;
737 err = proto_to_npindex(npi.protocol);
738 if (err < 0)
739 break;
740 i = err;
741 if (cmd == PPPIOCGNPMODE) {
742 err = -EFAULT;
743 npi.mode = ppp->npmode[i];
744 if (copy_to_user(argp, &npi, sizeof(npi)))
745 break;
746 } else {
747 ppp->npmode[i] = npi.mode;
748 /* we may be able to transmit more packets now (??) */
749 netif_wake_queue(ppp->dev);
750 }
751 err = 0;
752 break;
753
754 #ifdef CONFIG_PPP_FILTER
755 case PPPIOCSPASS:
756 {
757 struct sock_filter *code;
758
759 err = get_filter(argp, &code);
760 if (err >= 0) {
761 struct bpf_prog *pass_filter = NULL;
762 struct sock_fprog_kern fprog = {
763 .len = err,
764 .filter = code,
765 };
766
767 err = 0;
768 if (fprog.filter)
769 err = bpf_prog_create(&pass_filter, &fprog);
770 if (!err) {
771 ppp_lock(ppp);
772 if (ppp->pass_filter)
773 bpf_prog_destroy(ppp->pass_filter);
774 ppp->pass_filter = pass_filter;
775 ppp_unlock(ppp);
776 }
777 kfree(code);
778 }
779 break;
780 }
781 case PPPIOCSACTIVE:
782 {
783 struct sock_filter *code;
784
785 err = get_filter(argp, &code);
786 if (err >= 0) {
787 struct bpf_prog *active_filter = NULL;
788 struct sock_fprog_kern fprog = {
789 .len = err,
790 .filter = code,
791 };
792
793 err = 0;
794 if (fprog.filter)
795 err = bpf_prog_create(&active_filter, &fprog);
796 if (!err) {
797 ppp_lock(ppp);
798 if (ppp->active_filter)
799 bpf_prog_destroy(ppp->active_filter);
800 ppp->active_filter = active_filter;
801 ppp_unlock(ppp);
802 }
803 kfree(code);
804 }
805 break;
806 }
807 #endif /* CONFIG_PPP_FILTER */
808
809 #ifdef CONFIG_PPP_MULTILINK
810 case PPPIOCSMRRU:
811 if (get_user(val, p))
812 break;
813 ppp_recv_lock(ppp);
814 ppp->mrru = val;
815 ppp_recv_unlock(ppp);
816 err = 0;
817 break;
818 #endif /* CONFIG_PPP_MULTILINK */
819
820 default:
821 err = -ENOTTY;
822 }
823
824 out:
825 mutex_unlock(&ppp_mutex);
826
827 return err;
828 }
829
830 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
831 struct file *file, unsigned int cmd, unsigned long arg)
832 {
833 int unit, err = -EFAULT;
834 struct ppp *ppp;
835 struct channel *chan;
836 struct ppp_net *pn;
837 int __user *p = (int __user *)arg;
838
839 switch (cmd) {
840 case PPPIOCNEWUNIT:
841 /* Create a new ppp unit */
842 if (get_user(unit, p))
843 break;
844 err = ppp_create_interface(net, file, &unit);
845 if (err < 0)
846 break;
847
848 err = -EFAULT;
849 if (put_user(unit, p))
850 break;
851 err = 0;
852 break;
853
854 case PPPIOCATTACH:
855 /* Attach to an existing ppp unit */
856 if (get_user(unit, p))
857 break;
858 err = -ENXIO;
859 pn = ppp_pernet(net);
860 mutex_lock(&pn->all_ppp_mutex);
861 ppp = ppp_find_unit(pn, unit);
862 if (ppp) {
863 refcount_inc(&ppp->file.refcnt);
864 file->private_data = &ppp->file;
865 err = 0;
866 }
867 mutex_unlock(&pn->all_ppp_mutex);
868 break;
869
870 case PPPIOCATTCHAN:
871 if (get_user(unit, p))
872 break;
873 err = -ENXIO;
874 pn = ppp_pernet(net);
875 spin_lock_bh(&pn->all_channels_lock);
876 chan = ppp_find_channel(pn, unit);
877 if (chan) {
878 refcount_inc(&chan->file.refcnt);
879 file->private_data = &chan->file;
880 err = 0;
881 }
882 spin_unlock_bh(&pn->all_channels_lock);
883 break;
884
885 default:
886 err = -ENOTTY;
887 }
888
889 return err;
890 }
891
892 static const struct file_operations ppp_device_fops = {
893 .owner = THIS_MODULE,
894 .read = ppp_read,
895 .write = ppp_write,
896 .poll = ppp_poll,
897 .unlocked_ioctl = ppp_ioctl,
898 .open = ppp_open,
899 .release = ppp_release,
900 .llseek = noop_llseek,
901 };
902
903 static __net_init int ppp_init_net(struct net *net)
904 {
905 struct ppp_net *pn = net_generic(net, ppp_net_id);
906
907 idr_init(&pn->units_idr);
908 mutex_init(&pn->all_ppp_mutex);
909
910 INIT_LIST_HEAD(&pn->all_channels);
911 INIT_LIST_HEAD(&pn->new_channels);
912
913 spin_lock_init(&pn->all_channels_lock);
914
915 return 0;
916 }
917
918 static __net_exit void ppp_exit_net(struct net *net)
919 {
920 struct ppp_net *pn = net_generic(net, ppp_net_id);
921 struct net_device *dev;
922 struct net_device *aux;
923 struct ppp *ppp;
924 LIST_HEAD(list);
925 int id;
926
927 rtnl_lock();
928 for_each_netdev_safe(net, dev, aux) {
929 if (dev->netdev_ops == &ppp_netdev_ops)
930 unregister_netdevice_queue(dev, &list);
931 }
932
933 idr_for_each_entry(&pn->units_idr, ppp, id)
934 /* Skip devices already unregistered by previous loop */
935 if (!net_eq(dev_net(ppp->dev), net))
936 unregister_netdevice_queue(ppp->dev, &list);
937
938 unregister_netdevice_many(&list);
939 rtnl_unlock();
940
941 mutex_destroy(&pn->all_ppp_mutex);
942 idr_destroy(&pn->units_idr);
943 WARN_ON_ONCE(!list_empty(&pn->all_channels));
944 WARN_ON_ONCE(!list_empty(&pn->new_channels));
945 }
946
947 static struct pernet_operations ppp_net_ops = {
948 .init = ppp_init_net,
949 .exit = ppp_exit_net,
950 .id = &ppp_net_id,
951 .size = sizeof(struct ppp_net),
952 };
953
954 static int ppp_unit_register(struct ppp *ppp, int unit, bool ifname_is_set)
955 {
956 struct ppp_net *pn = ppp_pernet(ppp->ppp_net);
957 int ret;
958
959 mutex_lock(&pn->all_ppp_mutex);
960
961 if (unit < 0) {
962 ret = unit_get(&pn->units_idr, ppp);
963 if (ret < 0)
964 goto err;
965 } else {
966 /* Caller asked for a specific unit number. Fail with -EEXIST
967 * if unavailable. For backward compatibility, return -EEXIST
968 * too if idr allocation fails; this makes pppd retry without
969 * requesting a specific unit number.
970 */
971 if (unit_find(&pn->units_idr, unit)) {
972 ret = -EEXIST;
973 goto err;
974 }
975 ret = unit_set(&pn->units_idr, ppp, unit);
976 if (ret < 0) {
977 /* Rewrite error for backward compatibility */
978 ret = -EEXIST;
979 goto err;
980 }
981 }
982 ppp->file.index = ret;
983
984 if (!ifname_is_set)
985 snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ppp->file.index);
986
987 mutex_unlock(&pn->all_ppp_mutex);
988
989 ret = register_netdevice(ppp->dev);
990 if (ret < 0)
991 goto err_unit;
992
993 atomic_inc(&ppp_unit_count);
994
995 return 0;
996
997 err_unit:
998 mutex_lock(&pn->all_ppp_mutex);
999 unit_put(&pn->units_idr, ppp->file.index);
1000 err:
1001 mutex_unlock(&pn->all_ppp_mutex);
1002
1003 return ret;
1004 }
1005
1006 static int ppp_dev_configure(struct net *src_net, struct net_device *dev,
1007 const struct ppp_config *conf)
1008 {
1009 struct ppp *ppp = netdev_priv(dev);
1010 int indx;
1011 int err;
1012 int cpu;
1013
1014 ppp->dev = dev;
1015 ppp->ppp_net = src_net;
1016 ppp->mru = PPP_MRU;
1017 ppp->owner = conf->file;
1018
1019 init_ppp_file(&ppp->file, INTERFACE);
1020 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
1021
1022 for (indx = 0; indx < NUM_NP; ++indx)
1023 ppp->npmode[indx] = NPMODE_PASS;
1024 INIT_LIST_HEAD(&ppp->channels);
1025 spin_lock_init(&ppp->rlock);
1026 spin_lock_init(&ppp->wlock);
1027
1028 ppp->xmit_recursion = alloc_percpu(int);
1029 if (!ppp->xmit_recursion) {
1030 err = -ENOMEM;
1031 goto err1;
1032 }
1033 for_each_possible_cpu(cpu)
1034 (*per_cpu_ptr(ppp->xmit_recursion, cpu)) = 0;
1035
1036 #ifdef CONFIG_PPP_MULTILINK
1037 ppp->minseq = -1;
1038 skb_queue_head_init(&ppp->mrq);
1039 #endif /* CONFIG_PPP_MULTILINK */
1040 #ifdef CONFIG_PPP_FILTER
1041 ppp->pass_filter = NULL;
1042 ppp->active_filter = NULL;
1043 #endif /* CONFIG_PPP_FILTER */
1044
1045 err = ppp_unit_register(ppp, conf->unit, conf->ifname_is_set);
1046 if (err < 0)
1047 goto err2;
1048
1049 conf->file->private_data = &ppp->file;
1050
1051 return 0;
1052 err2:
1053 free_percpu(ppp->xmit_recursion);
1054 err1:
1055 return err;
1056 }
1057
1058 static const struct nla_policy ppp_nl_policy[IFLA_PPP_MAX + 1] = {
1059 [IFLA_PPP_DEV_FD] = { .type = NLA_S32 },
1060 };
1061
1062 static int ppp_nl_validate(struct nlattr *tb[], struct nlattr *data[],
1063 struct netlink_ext_ack *extack)
1064 {
1065 if (!data)
1066 return -EINVAL;
1067
1068 if (!data[IFLA_PPP_DEV_FD])
1069 return -EINVAL;
1070 if (nla_get_s32(data[IFLA_PPP_DEV_FD]) < 0)
1071 return -EBADF;
1072
1073 return 0;
1074 }
1075
1076 static int ppp_nl_newlink(struct net *src_net, struct net_device *dev,
1077 struct nlattr *tb[], struct nlattr *data[],
1078 struct netlink_ext_ack *extack)
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 ppp_xmit_process(ppp, skb);
1249
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 struct ppp *ppp;
1326
1327 netdev_lockdep_set_classes(dev);
1328
1329 ppp = netdev_priv(dev);
1330 /* Let the netdevice take a reference on the ppp file. This ensures
1331 * that ppp_destroy_interface() won't run before the device gets
1332 * unregistered.
1333 */
1334 refcount_inc(&ppp->file.refcnt);
1335
1336 return 0;
1337 }
1338
1339 static void ppp_dev_uninit(struct net_device *dev)
1340 {
1341 struct ppp *ppp = netdev_priv(dev);
1342 struct ppp_net *pn = ppp_pernet(ppp->ppp_net);
1343
1344 ppp_lock(ppp);
1345 ppp->closing = 1;
1346 ppp_unlock(ppp);
1347
1348 mutex_lock(&pn->all_ppp_mutex);
1349 unit_put(&pn->units_idr, ppp->file.index);
1350 mutex_unlock(&pn->all_ppp_mutex);
1351
1352 ppp->owner = NULL;
1353
1354 ppp->file.dead = 1;
1355 wake_up_interruptible(&ppp->file.rwait);
1356 }
1357
1358 static void ppp_dev_priv_destructor(struct net_device *dev)
1359 {
1360 struct ppp *ppp;
1361
1362 ppp = netdev_priv(dev);
1363 if (refcount_dec_and_test(&ppp->file.refcnt))
1364 ppp_destroy_interface(ppp);
1365 }
1366
1367 static const struct net_device_ops ppp_netdev_ops = {
1368 .ndo_init = ppp_dev_init,
1369 .ndo_uninit = ppp_dev_uninit,
1370 .ndo_start_xmit = ppp_start_xmit,
1371 .ndo_do_ioctl = ppp_net_ioctl,
1372 .ndo_get_stats64 = ppp_get_stats64,
1373 };
1374
1375 static struct device_type ppp_type = {
1376 .name = "ppp",
1377 };
1378
1379 static void ppp_setup(struct net_device *dev)
1380 {
1381 dev->netdev_ops = &ppp_netdev_ops;
1382 SET_NETDEV_DEVTYPE(dev, &ppp_type);
1383
1384 dev->features |= NETIF_F_LLTX;
1385
1386 dev->hard_header_len = PPP_HDRLEN;
1387 dev->mtu = PPP_MRU;
1388 dev->addr_len = 0;
1389 dev->tx_queue_len = 3;
1390 dev->type = ARPHRD_PPP;
1391 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1392 dev->priv_destructor = ppp_dev_priv_destructor;
1393 netif_keep_dst(dev);
1394 }
1395
1396 /*
1397 * Transmit-side routines.
1398 */
1399
1400 /* Called to do any work queued up on the transmit side that can now be done */
1401 static void __ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb)
1402 {
1403 ppp_xmit_lock(ppp);
1404 if (!ppp->closing) {
1405 ppp_push(ppp);
1406
1407 if (skb)
1408 skb_queue_tail(&ppp->file.xq, skb);
1409 while (!ppp->xmit_pending &&
1410 (skb = skb_dequeue(&ppp->file.xq)))
1411 ppp_send_frame(ppp, skb);
1412 /* If there's no work left to do, tell the core net
1413 code that we can accept some more. */
1414 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1415 netif_wake_queue(ppp->dev);
1416 else
1417 netif_stop_queue(ppp->dev);
1418 }
1419 ppp_xmit_unlock(ppp);
1420 }
1421
1422 static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb)
1423 {
1424 local_bh_disable();
1425
1426 if (unlikely(*this_cpu_ptr(ppp->xmit_recursion)))
1427 goto err;
1428
1429 (*this_cpu_ptr(ppp->xmit_recursion))++;
1430 __ppp_xmit_process(ppp, skb);
1431 (*this_cpu_ptr(ppp->xmit_recursion))--;
1432
1433 local_bh_enable();
1434
1435 return;
1436
1437 err:
1438 local_bh_enable();
1439
1440 kfree_skb(skb);
1441
1442 if (net_ratelimit())
1443 netdev_err(ppp->dev, "recursion detected\n");
1444 }
1445
1446 static inline struct sk_buff *
1447 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1448 {
1449 struct sk_buff *new_skb;
1450 int len;
1451 int new_skb_size = ppp->dev->mtu +
1452 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1453 int compressor_skb_size = ppp->dev->mtu +
1454 ppp->xcomp->comp_extra + PPP_HDRLEN;
1455 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1456 if (!new_skb) {
1457 if (net_ratelimit())
1458 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n");
1459 return NULL;
1460 }
1461 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1462 skb_reserve(new_skb,
1463 ppp->dev->hard_header_len - PPP_HDRLEN);
1464
1465 /* compressor still expects A/C bytes in hdr */
1466 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1467 new_skb->data, skb->len + 2,
1468 compressor_skb_size);
1469 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1470 consume_skb(skb);
1471 skb = new_skb;
1472 skb_put(skb, len);
1473 skb_pull(skb, 2); /* pull off A/C bytes */
1474 } else if (len == 0) {
1475 /* didn't compress, or CCP not up yet */
1476 consume_skb(new_skb);
1477 new_skb = skb;
1478 } else {
1479 /*
1480 * (len < 0)
1481 * MPPE requires that we do not send unencrypted
1482 * frames. The compressor will return -1 if we
1483 * should drop the frame. We cannot simply test
1484 * the compress_proto because MPPE and MPPC share
1485 * the same number.
1486 */
1487 if (net_ratelimit())
1488 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n");
1489 kfree_skb(skb);
1490 consume_skb(new_skb);
1491 new_skb = NULL;
1492 }
1493 return new_skb;
1494 }
1495
1496 /*
1497 * Compress and send a frame.
1498 * The caller should have locked the xmit path,
1499 * and xmit_pending should be 0.
1500 */
1501 static void
1502 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1503 {
1504 int proto = PPP_PROTO(skb);
1505 struct sk_buff *new_skb;
1506 int len;
1507 unsigned char *cp;
1508
1509 if (proto < 0x8000) {
1510 #ifdef CONFIG_PPP_FILTER
1511 /* check if we should pass this packet */
1512 /* the filter instructions are constructed assuming
1513 a four-byte PPP header on each packet */
1514 *(u8 *)skb_push(skb, 2) = 1;
1515 if (ppp->pass_filter &&
1516 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
1517 if (ppp->debug & 1)
1518 netdev_printk(KERN_DEBUG, ppp->dev,
1519 "PPP: outbound frame "
1520 "not passed\n");
1521 kfree_skb(skb);
1522 return;
1523 }
1524 /* if this packet passes the active filter, record the time */
1525 if (!(ppp->active_filter &&
1526 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
1527 ppp->last_xmit = jiffies;
1528 skb_pull(skb, 2);
1529 #else
1530 /* for data packets, record the time */
1531 ppp->last_xmit = jiffies;
1532 #endif /* CONFIG_PPP_FILTER */
1533 }
1534
1535 ++ppp->stats64.tx_packets;
1536 ppp->stats64.tx_bytes += skb->len - 2;
1537
1538 switch (proto) {
1539 case PPP_IP:
1540 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1541 break;
1542 /* try to do VJ TCP header compression */
1543 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1544 GFP_ATOMIC);
1545 if (!new_skb) {
1546 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n");
1547 goto drop;
1548 }
1549 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1550 cp = skb->data + 2;
1551 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1552 new_skb->data + 2, &cp,
1553 !(ppp->flags & SC_NO_TCP_CCID));
1554 if (cp == skb->data + 2) {
1555 /* didn't compress */
1556 consume_skb(new_skb);
1557 } else {
1558 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1559 proto = PPP_VJC_COMP;
1560 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1561 } else {
1562 proto = PPP_VJC_UNCOMP;
1563 cp[0] = skb->data[2];
1564 }
1565 consume_skb(skb);
1566 skb = new_skb;
1567 cp = skb_put(skb, len + 2);
1568 cp[0] = 0;
1569 cp[1] = proto;
1570 }
1571 break;
1572
1573 case PPP_CCP:
1574 /* peek at outbound CCP frames */
1575 ppp_ccp_peek(ppp, skb, 0);
1576 break;
1577 }
1578
1579 /* try to do packet compression */
1580 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state &&
1581 proto != PPP_LCP && proto != PPP_CCP) {
1582 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1583 if (net_ratelimit())
1584 netdev_err(ppp->dev,
1585 "ppp: compression required but "
1586 "down - pkt dropped.\n");
1587 goto drop;
1588 }
1589 skb = pad_compress_skb(ppp, skb);
1590 if (!skb)
1591 goto drop;
1592 }
1593
1594 /*
1595 * If we are waiting for traffic (demand dialling),
1596 * queue it up for pppd to receive.
1597 */
1598 if (ppp->flags & SC_LOOP_TRAFFIC) {
1599 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1600 goto drop;
1601 skb_queue_tail(&ppp->file.rq, skb);
1602 wake_up_interruptible(&ppp->file.rwait);
1603 return;
1604 }
1605
1606 ppp->xmit_pending = skb;
1607 ppp_push(ppp);
1608 return;
1609
1610 drop:
1611 kfree_skb(skb);
1612 ++ppp->dev->stats.tx_errors;
1613 }
1614
1615 /*
1616 * Try to send the frame in xmit_pending.
1617 * The caller should have the xmit path locked.
1618 */
1619 static void
1620 ppp_push(struct ppp *ppp)
1621 {
1622 struct list_head *list;
1623 struct channel *pch;
1624 struct sk_buff *skb = ppp->xmit_pending;
1625
1626 if (!skb)
1627 return;
1628
1629 list = &ppp->channels;
1630 if (list_empty(list)) {
1631 /* nowhere to send the packet, just drop it */
1632 ppp->xmit_pending = NULL;
1633 kfree_skb(skb);
1634 return;
1635 }
1636
1637 if ((ppp->flags & SC_MULTILINK) == 0) {
1638 /* not doing multilink: send it down the first channel */
1639 list = list->next;
1640 pch = list_entry(list, struct channel, clist);
1641
1642 spin_lock(&pch->downl);
1643 if (pch->chan) {
1644 if (pch->chan->ops->start_xmit(pch->chan, skb))
1645 ppp->xmit_pending = NULL;
1646 } else {
1647 /* channel got unregistered */
1648 kfree_skb(skb);
1649 ppp->xmit_pending = NULL;
1650 }
1651 spin_unlock(&pch->downl);
1652 return;
1653 }
1654
1655 #ifdef CONFIG_PPP_MULTILINK
1656 /* Multilink: fragment the packet over as many links
1657 as can take the packet at the moment. */
1658 if (!ppp_mp_explode(ppp, skb))
1659 return;
1660 #endif /* CONFIG_PPP_MULTILINK */
1661
1662 ppp->xmit_pending = NULL;
1663 kfree_skb(skb);
1664 }
1665
1666 #ifdef CONFIG_PPP_MULTILINK
1667 static bool mp_protocol_compress __read_mostly = true;
1668 module_param(mp_protocol_compress, bool, 0644);
1669 MODULE_PARM_DESC(mp_protocol_compress,
1670 "compress protocol id in multilink fragments");
1671
1672 /*
1673 * Divide a packet to be transmitted into fragments and
1674 * send them out the individual links.
1675 */
1676 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1677 {
1678 int len, totlen;
1679 int i, bits, hdrlen, mtu;
1680 int flen;
1681 int navail, nfree, nzero;
1682 int nbigger;
1683 int totspeed;
1684 int totfree;
1685 unsigned char *p, *q;
1686 struct list_head *list;
1687 struct channel *pch;
1688 struct sk_buff *frag;
1689 struct ppp_channel *chan;
1690
1691 totspeed = 0; /*total bitrate of the bundle*/
1692 nfree = 0; /* # channels which have no packet already queued */
1693 navail = 0; /* total # of usable channels (not deregistered) */
1694 nzero = 0; /* number of channels with zero speed associated*/
1695 totfree = 0; /*total # of channels available and
1696 *having no queued packets before
1697 *starting the fragmentation*/
1698
1699 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1700 i = 0;
1701 list_for_each_entry(pch, &ppp->channels, clist) {
1702 if (pch->chan) {
1703 pch->avail = 1;
1704 navail++;
1705 pch->speed = pch->chan->speed;
1706 } else {
1707 pch->avail = 0;
1708 }
1709 if (pch->avail) {
1710 if (skb_queue_empty(&pch->file.xq) ||
1711 !pch->had_frag) {
1712 if (pch->speed == 0)
1713 nzero++;
1714 else
1715 totspeed += pch->speed;
1716
1717 pch->avail = 2;
1718 ++nfree;
1719 ++totfree;
1720 }
1721 if (!pch->had_frag && i < ppp->nxchan)
1722 ppp->nxchan = i;
1723 }
1724 ++i;
1725 }
1726 /*
1727 * Don't start sending this packet unless at least half of
1728 * the channels are free. This gives much better TCP
1729 * performance if we have a lot of channels.
1730 */
1731 if (nfree == 0 || nfree < navail / 2)
1732 return 0; /* can't take now, leave it in xmit_pending */
1733
1734 /* Do protocol field compression */
1735 p = skb->data;
1736 len = skb->len;
1737 if (*p == 0 && mp_protocol_compress) {
1738 ++p;
1739 --len;
1740 }
1741
1742 totlen = len;
1743 nbigger = len % nfree;
1744
1745 /* skip to the channel after the one we last used
1746 and start at that one */
1747 list = &ppp->channels;
1748 for (i = 0; i < ppp->nxchan; ++i) {
1749 list = list->next;
1750 if (list == &ppp->channels) {
1751 i = 0;
1752 break;
1753 }
1754 }
1755
1756 /* create a fragment for each channel */
1757 bits = B;
1758 while (len > 0) {
1759 list = list->next;
1760 if (list == &ppp->channels) {
1761 i = 0;
1762 continue;
1763 }
1764 pch = list_entry(list, struct channel, clist);
1765 ++i;
1766 if (!pch->avail)
1767 continue;
1768
1769 /*
1770 * Skip this channel if it has a fragment pending already and
1771 * we haven't given a fragment to all of the free channels.
1772 */
1773 if (pch->avail == 1) {
1774 if (nfree > 0)
1775 continue;
1776 } else {
1777 pch->avail = 1;
1778 }
1779
1780 /* check the channel's mtu and whether it is still attached. */
1781 spin_lock(&pch->downl);
1782 if (pch->chan == NULL) {
1783 /* can't use this channel, it's being deregistered */
1784 if (pch->speed == 0)
1785 nzero--;
1786 else
1787 totspeed -= pch->speed;
1788
1789 spin_unlock(&pch->downl);
1790 pch->avail = 0;
1791 totlen = len;
1792 totfree--;
1793 nfree--;
1794 if (--navail == 0)
1795 break;
1796 continue;
1797 }
1798
1799 /*
1800 *if the channel speed is not set divide
1801 *the packet evenly among the free channels;
1802 *otherwise divide it according to the speed
1803 *of the channel we are going to transmit on
1804 */
1805 flen = len;
1806 if (nfree > 0) {
1807 if (pch->speed == 0) {
1808 flen = len/nfree;
1809 if (nbigger > 0) {
1810 flen++;
1811 nbigger--;
1812 }
1813 } else {
1814 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
1815 ((totspeed*totfree)/pch->speed)) - hdrlen;
1816 if (nbigger > 0) {
1817 flen += ((totfree - nzero)*pch->speed)/totspeed;
1818 nbigger -= ((totfree - nzero)*pch->speed)/
1819 totspeed;
1820 }
1821 }
1822 nfree--;
1823 }
1824
1825 /*
1826 *check if we are on the last channel or
1827 *we exceded the length of the data to
1828 *fragment
1829 */
1830 if ((nfree <= 0) || (flen > len))
1831 flen = len;
1832 /*
1833 *it is not worth to tx on slow channels:
1834 *in that case from the resulting flen according to the
1835 *above formula will be equal or less than zero.
1836 *Skip the channel in this case
1837 */
1838 if (flen <= 0) {
1839 pch->avail = 2;
1840 spin_unlock(&pch->downl);
1841 continue;
1842 }
1843
1844 /*
1845 * hdrlen includes the 2-byte PPP protocol field, but the
1846 * MTU counts only the payload excluding the protocol field.
1847 * (RFC1661 Section 2)
1848 */
1849 mtu = pch->chan->mtu - (hdrlen - 2);
1850 if (mtu < 4)
1851 mtu = 4;
1852 if (flen > mtu)
1853 flen = mtu;
1854 if (flen == len)
1855 bits |= E;
1856 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1857 if (!frag)
1858 goto noskb;
1859 q = skb_put(frag, flen + hdrlen);
1860
1861 /* make the MP header */
1862 put_unaligned_be16(PPP_MP, q);
1863 if (ppp->flags & SC_MP_XSHORTSEQ) {
1864 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1865 q[3] = ppp->nxseq;
1866 } else {
1867 q[2] = bits;
1868 q[3] = ppp->nxseq >> 16;
1869 q[4] = ppp->nxseq >> 8;
1870 q[5] = ppp->nxseq;
1871 }
1872
1873 memcpy(q + hdrlen, p, flen);
1874
1875 /* try to send it down the channel */
1876 chan = pch->chan;
1877 if (!skb_queue_empty(&pch->file.xq) ||
1878 !chan->ops->start_xmit(chan, frag))
1879 skb_queue_tail(&pch->file.xq, frag);
1880 pch->had_frag = 1;
1881 p += flen;
1882 len -= flen;
1883 ++ppp->nxseq;
1884 bits = 0;
1885 spin_unlock(&pch->downl);
1886 }
1887 ppp->nxchan = i;
1888
1889 return 1;
1890
1891 noskb:
1892 spin_unlock(&pch->downl);
1893 if (ppp->debug & 1)
1894 netdev_err(ppp->dev, "PPP: no memory (fragment)\n");
1895 ++ppp->dev->stats.tx_errors;
1896 ++ppp->nxseq;
1897 return 1; /* abandon the frame */
1898 }
1899 #endif /* CONFIG_PPP_MULTILINK */
1900
1901 /* Try to send data out on a channel */
1902 static void __ppp_channel_push(struct channel *pch)
1903 {
1904 struct sk_buff *skb;
1905 struct ppp *ppp;
1906
1907 spin_lock(&pch->downl);
1908 if (pch->chan) {
1909 while (!skb_queue_empty(&pch->file.xq)) {
1910 skb = skb_dequeue(&pch->file.xq);
1911 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1912 /* put the packet back and try again later */
1913 skb_queue_head(&pch->file.xq, skb);
1914 break;
1915 }
1916 }
1917 } else {
1918 /* channel got deregistered */
1919 skb_queue_purge(&pch->file.xq);
1920 }
1921 spin_unlock(&pch->downl);
1922 /* see if there is anything from the attached unit to be sent */
1923 if (skb_queue_empty(&pch->file.xq)) {
1924 ppp = pch->ppp;
1925 if (ppp)
1926 __ppp_xmit_process(ppp, NULL);
1927 }
1928 }
1929
1930 static void ppp_channel_push(struct channel *pch)
1931 {
1932 read_lock_bh(&pch->upl);
1933 if (pch->ppp) {
1934 (*this_cpu_ptr(pch->ppp->xmit_recursion))++;
1935 __ppp_channel_push(pch);
1936 (*this_cpu_ptr(pch->ppp->xmit_recursion))--;
1937 } else {
1938 __ppp_channel_push(pch);
1939 }
1940 read_unlock_bh(&pch->upl);
1941 }
1942
1943 /*
1944 * Receive-side routines.
1945 */
1946
1947 struct ppp_mp_skb_parm {
1948 u32 sequence;
1949 u8 BEbits;
1950 };
1951 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb))
1952
1953 static inline void
1954 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1955 {
1956 ppp_recv_lock(ppp);
1957 if (!ppp->closing)
1958 ppp_receive_frame(ppp, skb, pch);
1959 else
1960 kfree_skb(skb);
1961 ppp_recv_unlock(ppp);
1962 }
1963
1964 /**
1965 * __ppp_decompress_proto - Decompress protocol field, slim version.
1966 * @skb: Socket buffer where protocol field should be decompressed. It must have
1967 * at least 1 byte of head room and 1 byte of linear data. First byte of
1968 * data must be a protocol field byte.
1969 *
1970 * Decompress protocol field in PPP header if it's compressed, e.g. when
1971 * Protocol-Field-Compression (PFC) was negotiated. No checks w.r.t. skb data
1972 * length are done in this function.
1973 */
1974 static void __ppp_decompress_proto(struct sk_buff *skb)
1975 {
1976 if (skb->data[0] & 0x01)
1977 *(u8 *)skb_push(skb, 1) = 0x00;
1978 }
1979
1980 /**
1981 * ppp_decompress_proto - Check skb data room and decompress protocol field.
1982 * @skb: Socket buffer where protocol field should be decompressed. First byte
1983 * of data must be a protocol field byte.
1984 *
1985 * Decompress protocol field in PPP header if it's compressed, e.g. when
1986 * Protocol-Field-Compression (PFC) was negotiated. This function also makes
1987 * sure that skb data room is sufficient for Protocol field, before and after
1988 * decompression.
1989 *
1990 * Return: true - decompressed successfully, false - not enough room in skb.
1991 */
1992 static bool ppp_decompress_proto(struct sk_buff *skb)
1993 {
1994 /* At least one byte should be present (if protocol is compressed) */
1995 if (!pskb_may_pull(skb, 1))
1996 return false;
1997
1998 __ppp_decompress_proto(skb);
1999
2000 /* Protocol field should occupy 2 bytes when not compressed */
2001 return pskb_may_pull(skb, 2);
2002 }
2003
2004 void
2005 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
2006 {
2007 struct channel *pch = chan->ppp;
2008 int proto;
2009
2010 if (!pch) {
2011 kfree_skb(skb);
2012 return;
2013 }
2014
2015 read_lock_bh(&pch->upl);
2016 if (!ppp_decompress_proto(skb)) {
2017 kfree_skb(skb);
2018 if (pch->ppp) {
2019 ++pch->ppp->dev->stats.rx_length_errors;
2020 ppp_receive_error(pch->ppp);
2021 }
2022 goto done;
2023 }
2024
2025 proto = PPP_PROTO(skb);
2026 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
2027 /* put it on the channel queue */
2028 skb_queue_tail(&pch->file.rq, skb);
2029 /* drop old frames if queue too long */
2030 while (pch->file.rq.qlen > PPP_MAX_RQLEN &&
2031 (skb = skb_dequeue(&pch->file.rq)))
2032 kfree_skb(skb);
2033 wake_up_interruptible(&pch->file.rwait);
2034 } else {
2035 ppp_do_recv(pch->ppp, skb, pch);
2036 }
2037
2038 done:
2039 read_unlock_bh(&pch->upl);
2040 }
2041
2042 /* Put a 0-length skb in the receive queue as an error indication */
2043 void
2044 ppp_input_error(struct ppp_channel *chan, int code)
2045 {
2046 struct channel *pch = chan->ppp;
2047 struct sk_buff *skb;
2048
2049 if (!pch)
2050 return;
2051
2052 read_lock_bh(&pch->upl);
2053 if (pch->ppp) {
2054 skb = alloc_skb(0, GFP_ATOMIC);
2055 if (skb) {
2056 skb->len = 0; /* probably unnecessary */
2057 skb->cb[0] = code;
2058 ppp_do_recv(pch->ppp, skb, pch);
2059 }
2060 }
2061 read_unlock_bh(&pch->upl);
2062 }
2063
2064 /*
2065 * We come in here to process a received frame.
2066 * The receive side of the ppp unit is locked.
2067 */
2068 static void
2069 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
2070 {
2071 /* note: a 0-length skb is used as an error indication */
2072 if (skb->len > 0) {
2073 skb_checksum_complete_unset(skb);
2074 #ifdef CONFIG_PPP_MULTILINK
2075 /* XXX do channel-level decompression here */
2076 if (PPP_PROTO(skb) == PPP_MP)
2077 ppp_receive_mp_frame(ppp, skb, pch);
2078 else
2079 #endif /* CONFIG_PPP_MULTILINK */
2080 ppp_receive_nonmp_frame(ppp, skb);
2081 } else {
2082 kfree_skb(skb);
2083 ppp_receive_error(ppp);
2084 }
2085 }
2086
2087 static void
2088 ppp_receive_error(struct ppp *ppp)
2089 {
2090 ++ppp->dev->stats.rx_errors;
2091 if (ppp->vj)
2092 slhc_toss(ppp->vj);
2093 }
2094
2095 static void
2096 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
2097 {
2098 struct sk_buff *ns;
2099 int proto, len, npi;
2100
2101 /*
2102 * Decompress the frame, if compressed.
2103 * Note that some decompressors need to see uncompressed frames
2104 * that come in as well as compressed frames.
2105 */
2106 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) &&
2107 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
2108 skb = ppp_decompress_frame(ppp, skb);
2109
2110 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
2111 goto err;
2112
2113 /* At this point the "Protocol" field MUST be decompressed, either in
2114 * ppp_input(), ppp_decompress_frame() or in ppp_receive_mp_frame().
2115 */
2116 proto = PPP_PROTO(skb);
2117 switch (proto) {
2118 case PPP_VJC_COMP:
2119 /* decompress VJ compressed packets */
2120 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
2121 goto err;
2122
2123 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
2124 /* copy to a new sk_buff with more tailroom */
2125 ns = dev_alloc_skb(skb->len + 128);
2126 if (!ns) {
2127 netdev_err(ppp->dev, "PPP: no memory "
2128 "(VJ decomp)\n");
2129 goto err;
2130 }
2131 skb_reserve(ns, 2);
2132 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
2133 consume_skb(skb);
2134 skb = ns;
2135 }
2136 else
2137 skb->ip_summed = CHECKSUM_NONE;
2138
2139 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
2140 if (len <= 0) {
2141 netdev_printk(KERN_DEBUG, ppp->dev,
2142 "PPP: VJ decompression error\n");
2143 goto err;
2144 }
2145 len += 2;
2146 if (len > skb->len)
2147 skb_put(skb, len - skb->len);
2148 else if (len < skb->len)
2149 skb_trim(skb, len);
2150 proto = PPP_IP;
2151 break;
2152
2153 case PPP_VJC_UNCOMP:
2154 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
2155 goto err;
2156
2157 /* Until we fix the decompressor need to make sure
2158 * data portion is linear.
2159 */
2160 if (!pskb_may_pull(skb, skb->len))
2161 goto err;
2162
2163 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
2164 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n");
2165 goto err;
2166 }
2167 proto = PPP_IP;
2168 break;
2169
2170 case PPP_CCP:
2171 ppp_ccp_peek(ppp, skb, 1);
2172 break;
2173 }
2174
2175 ++ppp->stats64.rx_packets;
2176 ppp->stats64.rx_bytes += skb->len - 2;
2177
2178 npi = proto_to_npindex(proto);
2179 if (npi < 0) {
2180 /* control or unknown frame - pass it to pppd */
2181 skb_queue_tail(&ppp->file.rq, skb);
2182 /* limit queue length by dropping old frames */
2183 while (ppp->file.rq.qlen > PPP_MAX_RQLEN &&
2184 (skb = skb_dequeue(&ppp->file.rq)))
2185 kfree_skb(skb);
2186 /* wake up any process polling or blocking on read */
2187 wake_up_interruptible(&ppp->file.rwait);
2188
2189 } else {
2190 /* network protocol frame - give it to the kernel */
2191
2192 #ifdef CONFIG_PPP_FILTER
2193 /* check if the packet passes the pass and active filters */
2194 /* the filter instructions are constructed assuming
2195 a four-byte PPP header on each packet */
2196 if (ppp->pass_filter || ppp->active_filter) {
2197 if (skb_unclone(skb, GFP_ATOMIC))
2198 goto err;
2199
2200 *(u8 *)skb_push(skb, 2) = 0;
2201 if (ppp->pass_filter &&
2202 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
2203 if (ppp->debug & 1)
2204 netdev_printk(KERN_DEBUG, ppp->dev,
2205 "PPP: inbound frame "
2206 "not passed\n");
2207 kfree_skb(skb);
2208 return;
2209 }
2210 if (!(ppp->active_filter &&
2211 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
2212 ppp->last_recv = jiffies;
2213 __skb_pull(skb, 2);
2214 } else
2215 #endif /* CONFIG_PPP_FILTER */
2216 ppp->last_recv = jiffies;
2217
2218 if ((ppp->dev->flags & IFF_UP) == 0 ||
2219 ppp->npmode[npi] != NPMODE_PASS) {
2220 kfree_skb(skb);
2221 } else {
2222 /* chop off protocol */
2223 skb_pull_rcsum(skb, 2);
2224 skb->dev = ppp->dev;
2225 skb->protocol = htons(npindex_to_ethertype[npi]);
2226 skb_reset_mac_header(skb);
2227 skb_scrub_packet(skb, !net_eq(ppp->ppp_net,
2228 dev_net(ppp->dev)));
2229 netif_rx(skb);
2230 }
2231 }
2232 return;
2233
2234 err:
2235 kfree_skb(skb);
2236 ppp_receive_error(ppp);
2237 }
2238
2239 static struct sk_buff *
2240 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
2241 {
2242 int proto = PPP_PROTO(skb);
2243 struct sk_buff *ns;
2244 int len;
2245
2246 /* Until we fix all the decompressor's need to make sure
2247 * data portion is linear.
2248 */
2249 if (!pskb_may_pull(skb, skb->len))
2250 goto err;
2251
2252 if (proto == PPP_COMP) {
2253 int obuff_size;
2254
2255 switch(ppp->rcomp->compress_proto) {
2256 case CI_MPPE:
2257 obuff_size = ppp->mru + PPP_HDRLEN + 1;
2258 break;
2259 default:
2260 obuff_size = ppp->mru + PPP_HDRLEN;
2261 break;
2262 }
2263
2264 ns = dev_alloc_skb(obuff_size);
2265 if (!ns) {
2266 netdev_err(ppp->dev, "ppp_decompress_frame: "
2267 "no memory\n");
2268 goto err;
2269 }
2270 /* the decompressor still expects the A/C bytes in the hdr */
2271 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
2272 skb->len + 2, ns->data, obuff_size);
2273 if (len < 0) {
2274 /* Pass the compressed frame to pppd as an
2275 error indication. */
2276 if (len == DECOMP_FATALERROR)
2277 ppp->rstate |= SC_DC_FERROR;
2278 kfree_skb(ns);
2279 goto err;
2280 }
2281
2282 consume_skb(skb);
2283 skb = ns;
2284 skb_put(skb, len);
2285 skb_pull(skb, 2); /* pull off the A/C bytes */
2286
2287 /* Don't call __ppp_decompress_proto() here, but instead rely on
2288 * corresponding algo (mppe/bsd/deflate) to decompress it.
2289 */
2290 } else {
2291 /* Uncompressed frame - pass to decompressor so it
2292 can update its dictionary if necessary. */
2293 if (ppp->rcomp->incomp)
2294 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
2295 skb->len + 2);
2296 }
2297
2298 return skb;
2299
2300 err:
2301 ppp->rstate |= SC_DC_ERROR;
2302 ppp_receive_error(ppp);
2303 return skb;
2304 }
2305
2306 #ifdef CONFIG_PPP_MULTILINK
2307 /*
2308 * Receive a multilink frame.
2309 * We put it on the reconstruction queue and then pull off
2310 * as many completed frames as we can.
2311 */
2312 static void
2313 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
2314 {
2315 u32 mask, seq;
2316 struct channel *ch;
2317 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
2318
2319 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
2320 goto err; /* no good, throw it away */
2321
2322 /* Decode sequence number and begin/end bits */
2323 if (ppp->flags & SC_MP_SHORTSEQ) {
2324 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
2325 mask = 0xfff;
2326 } else {
2327 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
2328 mask = 0xffffff;
2329 }
2330 PPP_MP_CB(skb)->BEbits = skb->data[2];
2331 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
2332
2333 /*
2334 * Do protocol ID decompression on the first fragment of each packet.
2335 * We have to do that here, because ppp_receive_nonmp_frame() expects
2336 * decompressed protocol field.
2337 */
2338 if (PPP_MP_CB(skb)->BEbits & B)
2339 __ppp_decompress_proto(skb);
2340
2341 /*
2342 * Expand sequence number to 32 bits, making it as close
2343 * as possible to ppp->minseq.
2344 */
2345 seq |= ppp->minseq & ~mask;
2346 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
2347 seq += mask + 1;
2348 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
2349 seq -= mask + 1; /* should never happen */
2350 PPP_MP_CB(skb)->sequence = seq;
2351 pch->lastseq = seq;
2352
2353 /*
2354 * If this packet comes before the next one we were expecting,
2355 * drop it.
2356 */
2357 if (seq_before(seq, ppp->nextseq)) {
2358 kfree_skb(skb);
2359 ++ppp->dev->stats.rx_dropped;
2360 ppp_receive_error(ppp);
2361 return;
2362 }
2363
2364 /*
2365 * Reevaluate minseq, the minimum over all channels of the
2366 * last sequence number received on each channel. Because of
2367 * the increasing sequence number rule, we know that any fragment
2368 * before `minseq' which hasn't arrived is never going to arrive.
2369 * The list of channels can't change because we have the receive
2370 * side of the ppp unit locked.
2371 */
2372 list_for_each_entry(ch, &ppp->channels, clist) {
2373 if (seq_before(ch->lastseq, seq))
2374 seq = ch->lastseq;
2375 }
2376 if (seq_before(ppp->minseq, seq))
2377 ppp->minseq = seq;
2378
2379 /* Put the fragment on the reconstruction queue */
2380 ppp_mp_insert(ppp, skb);
2381
2382 /* If the queue is getting long, don't wait any longer for packets
2383 before the start of the queue. */
2384 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
2385 struct sk_buff *mskb = skb_peek(&ppp->mrq);
2386 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence))
2387 ppp->minseq = PPP_MP_CB(mskb)->sequence;
2388 }
2389
2390 /* Pull completed packets off the queue and receive them. */
2391 while ((skb = ppp_mp_reconstruct(ppp))) {
2392 if (pskb_may_pull(skb, 2))
2393 ppp_receive_nonmp_frame(ppp, skb);
2394 else {
2395 ++ppp->dev->stats.rx_length_errors;
2396 kfree_skb(skb);
2397 ppp_receive_error(ppp);
2398 }
2399 }
2400
2401 return;
2402
2403 err:
2404 kfree_skb(skb);
2405 ppp_receive_error(ppp);
2406 }
2407
2408 /*
2409 * Insert a fragment on the MP reconstruction queue.
2410 * The queue is ordered by increasing sequence number.
2411 */
2412 static void
2413 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
2414 {
2415 struct sk_buff *p;
2416 struct sk_buff_head *list = &ppp->mrq;
2417 u32 seq = PPP_MP_CB(skb)->sequence;
2418
2419 /* N.B. we don't need to lock the list lock because we have the
2420 ppp unit receive-side lock. */
2421 skb_queue_walk(list, p) {
2422 if (seq_before(seq, PPP_MP_CB(p)->sequence))
2423 break;
2424 }
2425 __skb_queue_before(list, p, skb);
2426 }
2427
2428 /*
2429 * Reconstruct a packet from the MP fragment queue.
2430 * We go through increasing sequence numbers until we find a
2431 * complete packet, or we get to the sequence number for a fragment
2432 * which hasn't arrived but might still do so.
2433 */
2434 static struct sk_buff *
2435 ppp_mp_reconstruct(struct ppp *ppp)
2436 {
2437 u32 seq = ppp->nextseq;
2438 u32 minseq = ppp->minseq;
2439 struct sk_buff_head *list = &ppp->mrq;
2440 struct sk_buff *p, *tmp;
2441 struct sk_buff *head, *tail;
2442 struct sk_buff *skb = NULL;
2443 int lost = 0, len = 0;
2444
2445 if (ppp->mrru == 0) /* do nothing until mrru is set */
2446 return NULL;
2447 head = __skb_peek(list);
2448 tail = NULL;
2449 skb_queue_walk_safe(list, p, tmp) {
2450 again:
2451 if (seq_before(PPP_MP_CB(p)->sequence, seq)) {
2452 /* this can't happen, anyway ignore the skb */
2453 netdev_err(ppp->dev, "ppp_mp_reconstruct bad "
2454 "seq %u < %u\n",
2455 PPP_MP_CB(p)->sequence, seq);
2456 __skb_unlink(p, list);
2457 kfree_skb(p);
2458 continue;
2459 }
2460 if (PPP_MP_CB(p)->sequence != seq) {
2461 u32 oldseq;
2462 /* Fragment `seq' is missing. If it is after
2463 minseq, it might arrive later, so stop here. */
2464 if (seq_after(seq, minseq))
2465 break;
2466 /* Fragment `seq' is lost, keep going. */
2467 lost = 1;
2468 oldseq = seq;
2469 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)?
2470 minseq + 1: PPP_MP_CB(p)->sequence;
2471
2472 if (ppp->debug & 1)
2473 netdev_printk(KERN_DEBUG, ppp->dev,
2474 "lost frag %u..%u\n",
2475 oldseq, seq-1);
2476
2477 goto again;
2478 }
2479
2480 /*
2481 * At this point we know that all the fragments from
2482 * ppp->nextseq to seq are either present or lost.
2483 * Also, there are no complete packets in the queue
2484 * that have no missing fragments and end before this
2485 * fragment.
2486 */
2487
2488 /* B bit set indicates this fragment starts a packet */
2489 if (PPP_MP_CB(p)->BEbits & B) {
2490 head = p;
2491 lost = 0;
2492 len = 0;
2493 }
2494
2495 len += p->len;
2496
2497 /* Got a complete packet yet? */
2498 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) &&
2499 (PPP_MP_CB(head)->BEbits & B)) {
2500 if (len > ppp->mrru + 2) {
2501 ++ppp->dev->stats.rx_length_errors;
2502 netdev_printk(KERN_DEBUG, ppp->dev,
2503 "PPP: reconstructed packet"
2504 " is too long (%d)\n", len);
2505 } else {
2506 tail = p;
2507 break;
2508 }
2509 ppp->nextseq = seq + 1;
2510 }
2511
2512 /*
2513 * If this is the ending fragment of a packet,
2514 * and we haven't found a complete valid packet yet,
2515 * we can discard up to and including this fragment.
2516 */
2517 if (PPP_MP_CB(p)->BEbits & E) {
2518 struct sk_buff *tmp2;
2519
2520 skb_queue_reverse_walk_from_safe(list, p, tmp2) {
2521 if (ppp->debug & 1)
2522 netdev_printk(KERN_DEBUG, ppp->dev,
2523 "discarding frag %u\n",
2524 PPP_MP_CB(p)->sequence);
2525 __skb_unlink(p, list);
2526 kfree_skb(p);
2527 }
2528 head = skb_peek(list);
2529 if (!head)
2530 break;
2531 }
2532 ++seq;
2533 }
2534
2535 /* If we have a complete packet, copy it all into one skb. */
2536 if (tail != NULL) {
2537 /* If we have discarded any fragments,
2538 signal a receive error. */
2539 if (PPP_MP_CB(head)->sequence != ppp->nextseq) {
2540 skb_queue_walk_safe(list, p, tmp) {
2541 if (p == head)
2542 break;
2543 if (ppp->debug & 1)
2544 netdev_printk(KERN_DEBUG, ppp->dev,
2545 "discarding frag %u\n",
2546 PPP_MP_CB(p)->sequence);
2547 __skb_unlink(p, list);
2548 kfree_skb(p);
2549 }
2550
2551 if (ppp->debug & 1)
2552 netdev_printk(KERN_DEBUG, ppp->dev,
2553 " missed pkts %u..%u\n",
2554 ppp->nextseq,
2555 PPP_MP_CB(head)->sequence-1);
2556 ++ppp->dev->stats.rx_dropped;
2557 ppp_receive_error(ppp);
2558 }
2559
2560 skb = head;
2561 if (head != tail) {
2562 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list;
2563 p = skb_queue_next(list, head);
2564 __skb_unlink(skb, list);
2565 skb_queue_walk_from_safe(list, p, tmp) {
2566 __skb_unlink(p, list);
2567 *fragpp = p;
2568 p->next = NULL;
2569 fragpp = &p->next;
2570
2571 skb->len += p->len;
2572 skb->data_len += p->len;
2573 skb->truesize += p->truesize;
2574
2575 if (p == tail)
2576 break;
2577 }
2578 } else {
2579 __skb_unlink(skb, list);
2580 }
2581
2582 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1;
2583 }
2584
2585 return skb;
2586 }
2587 #endif /* CONFIG_PPP_MULTILINK */
2588
2589 /*
2590 * Channel interface.
2591 */
2592
2593 /* Create a new, unattached ppp channel. */
2594 int ppp_register_channel(struct ppp_channel *chan)
2595 {
2596 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2597 }
2598
2599 /* Create a new, unattached ppp channel for specified net. */
2600 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
2601 {
2602 struct channel *pch;
2603 struct ppp_net *pn;
2604
2605 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2606 if (!pch)
2607 return -ENOMEM;
2608
2609 pn = ppp_pernet(net);
2610
2611 pch->ppp = NULL;
2612 pch->chan = chan;
2613 pch->chan_net = get_net(net);
2614 chan->ppp = pch;
2615 init_ppp_file(&pch->file, CHANNEL);
2616 pch->file.hdrlen = chan->hdrlen;
2617 #ifdef CONFIG_PPP_MULTILINK
2618 pch->lastseq = -1;
2619 #endif /* CONFIG_PPP_MULTILINK */
2620 init_rwsem(&pch->chan_sem);
2621 spin_lock_init(&pch->downl);
2622 rwlock_init(&pch->upl);
2623
2624 spin_lock_bh(&pn->all_channels_lock);
2625 pch->file.index = ++pn->last_channel_index;
2626 list_add(&pch->list, &pn->new_channels);
2627 atomic_inc(&channel_count);
2628 spin_unlock_bh(&pn->all_channels_lock);
2629
2630 return 0;
2631 }
2632
2633 /*
2634 * Return the index of a channel.
2635 */
2636 int ppp_channel_index(struct ppp_channel *chan)
2637 {
2638 struct channel *pch = chan->ppp;
2639
2640 if (pch)
2641 return pch->file.index;
2642 return -1;
2643 }
2644
2645 /*
2646 * Return the PPP unit number to which a channel is connected.
2647 */
2648 int ppp_unit_number(struct ppp_channel *chan)
2649 {
2650 struct channel *pch = chan->ppp;
2651 int unit = -1;
2652
2653 if (pch) {
2654 read_lock_bh(&pch->upl);
2655 if (pch->ppp)
2656 unit = pch->ppp->file.index;
2657 read_unlock_bh(&pch->upl);
2658 }
2659 return unit;
2660 }
2661
2662 /*
2663 * Return the PPP device interface name of a channel.
2664 */
2665 char *ppp_dev_name(struct ppp_channel *chan)
2666 {
2667 struct channel *pch = chan->ppp;
2668 char *name = NULL;
2669
2670 if (pch) {
2671 read_lock_bh(&pch->upl);
2672 if (pch->ppp && pch->ppp->dev)
2673 name = pch->ppp->dev->name;
2674 read_unlock_bh(&pch->upl);
2675 }
2676 return name;
2677 }
2678
2679
2680 /*
2681 * Disconnect a channel from the generic layer.
2682 * This must be called in process context.
2683 */
2684 void
2685 ppp_unregister_channel(struct ppp_channel *chan)
2686 {
2687 struct channel *pch = chan->ppp;
2688 struct ppp_net *pn;
2689
2690 if (!pch)
2691 return; /* should never happen */
2692
2693 chan->ppp = NULL;
2694
2695 /*
2696 * This ensures that we have returned from any calls into the
2697 * the channel's start_xmit or ioctl routine before we proceed.
2698 */
2699 down_write(&pch->chan_sem);
2700 spin_lock_bh(&pch->downl);
2701 pch->chan = NULL;
2702 spin_unlock_bh(&pch->downl);
2703 up_write(&pch->chan_sem);
2704 ppp_disconnect_channel(pch);
2705
2706 pn = ppp_pernet(pch->chan_net);
2707 spin_lock_bh(&pn->all_channels_lock);
2708 list_del(&pch->list);
2709 spin_unlock_bh(&pn->all_channels_lock);
2710
2711 pch->file.dead = 1;
2712 wake_up_interruptible(&pch->file.rwait);
2713 if (refcount_dec_and_test(&pch->file.refcnt))
2714 ppp_destroy_channel(pch);
2715 }
2716
2717 /*
2718 * Callback from a channel when it can accept more to transmit.
2719 * This should be called at BH/softirq level, not interrupt level.
2720 */
2721 void
2722 ppp_output_wakeup(struct ppp_channel *chan)
2723 {
2724 struct channel *pch = chan->ppp;
2725
2726 if (!pch)
2727 return;
2728 ppp_channel_push(pch);
2729 }
2730
2731 /*
2732 * Compression control.
2733 */
2734
2735 /* Process the PPPIOCSCOMPRESS ioctl. */
2736 static int
2737 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2738 {
2739 int err;
2740 struct compressor *cp, *ocomp;
2741 struct ppp_option_data data;
2742 void *state, *ostate;
2743 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2744
2745 err = -EFAULT;
2746 if (copy_from_user(&data, (void __user *) arg, sizeof(data)))
2747 goto out;
2748 if (data.length > CCP_MAX_OPTION_LENGTH)
2749 goto out;
2750 if (copy_from_user(ccp_option, (void __user *) data.ptr, data.length))
2751 goto out;
2752
2753 err = -EINVAL;
2754 if (data.length < 2 || ccp_option[1] < 2 || ccp_option[1] > data.length)
2755 goto out;
2756
2757 cp = try_then_request_module(
2758 find_compressor(ccp_option[0]),
2759 "ppp-compress-%d", ccp_option[0]);
2760 if (!cp)
2761 goto out;
2762
2763 err = -ENOBUFS;
2764 if (data.transmit) {
2765 state = cp->comp_alloc(ccp_option, data.length);
2766 if (state) {
2767 ppp_xmit_lock(ppp);
2768 ppp->xstate &= ~SC_COMP_RUN;
2769 ocomp = ppp->xcomp;
2770 ostate = ppp->xc_state;
2771 ppp->xcomp = cp;
2772 ppp->xc_state = state;
2773 ppp_xmit_unlock(ppp);
2774 if (ostate) {
2775 ocomp->comp_free(ostate);
2776 module_put(ocomp->owner);
2777 }
2778 err = 0;
2779 } else
2780 module_put(cp->owner);
2781
2782 } else {
2783 state = cp->decomp_alloc(ccp_option, data.length);
2784 if (state) {
2785 ppp_recv_lock(ppp);
2786 ppp->rstate &= ~SC_DECOMP_RUN;
2787 ocomp = ppp->rcomp;
2788 ostate = ppp->rc_state;
2789 ppp->rcomp = cp;
2790 ppp->rc_state = state;
2791 ppp_recv_unlock(ppp);
2792 if (ostate) {
2793 ocomp->decomp_free(ostate);
2794 module_put(ocomp->owner);
2795 }
2796 err = 0;
2797 } else
2798 module_put(cp->owner);
2799 }
2800
2801 out:
2802 return err;
2803 }
2804
2805 /*
2806 * Look at a CCP packet and update our state accordingly.
2807 * We assume the caller has the xmit or recv path locked.
2808 */
2809 static void
2810 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2811 {
2812 unsigned char *dp;
2813 int len;
2814
2815 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2816 return; /* no header */
2817 dp = skb->data + 2;
2818
2819 switch (CCP_CODE(dp)) {
2820 case CCP_CONFREQ:
2821
2822 /* A ConfReq starts negotiation of compression
2823 * in one direction of transmission,
2824 * and hence brings it down...but which way?
2825 *
2826 * Remember:
2827 * A ConfReq indicates what the sender would like to receive
2828 */
2829 if(inbound)
2830 /* He is proposing what I should send */
2831 ppp->xstate &= ~SC_COMP_RUN;
2832 else
2833 /* I am proposing to what he should send */
2834 ppp->rstate &= ~SC_DECOMP_RUN;
2835
2836 break;
2837
2838 case CCP_TERMREQ:
2839 case CCP_TERMACK:
2840 /*
2841 * CCP is going down, both directions of transmission
2842 */
2843 ppp->rstate &= ~SC_DECOMP_RUN;
2844 ppp->xstate &= ~SC_COMP_RUN;
2845 break;
2846
2847 case CCP_CONFACK:
2848 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2849 break;
2850 len = CCP_LENGTH(dp);
2851 if (!pskb_may_pull(skb, len + 2))
2852 return; /* too short */
2853 dp += CCP_HDRLEN;
2854 len -= CCP_HDRLEN;
2855 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2856 break;
2857 if (inbound) {
2858 /* we will start receiving compressed packets */
2859 if (!ppp->rc_state)
2860 break;
2861 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2862 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2863 ppp->rstate |= SC_DECOMP_RUN;
2864 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2865 }
2866 } else {
2867 /* we will soon start sending compressed packets */
2868 if (!ppp->xc_state)
2869 break;
2870 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2871 ppp->file.index, 0, ppp->debug))
2872 ppp->xstate |= SC_COMP_RUN;
2873 }
2874 break;
2875
2876 case CCP_RESETACK:
2877 /* reset the [de]compressor */
2878 if ((ppp->flags & SC_CCP_UP) == 0)
2879 break;
2880 if (inbound) {
2881 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2882 ppp->rcomp->decomp_reset(ppp->rc_state);
2883 ppp->rstate &= ~SC_DC_ERROR;
2884 }
2885 } else {
2886 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2887 ppp->xcomp->comp_reset(ppp->xc_state);
2888 }
2889 break;
2890 }
2891 }
2892
2893 /* Free up compression resources. */
2894 static void
2895 ppp_ccp_closed(struct ppp *ppp)
2896 {
2897 void *xstate, *rstate;
2898 struct compressor *xcomp, *rcomp;
2899
2900 ppp_lock(ppp);
2901 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2902 ppp->xstate = 0;
2903 xcomp = ppp->xcomp;
2904 xstate = ppp->xc_state;
2905 ppp->xc_state = NULL;
2906 ppp->rstate = 0;
2907 rcomp = ppp->rcomp;
2908 rstate = ppp->rc_state;
2909 ppp->rc_state = NULL;
2910 ppp_unlock(ppp);
2911
2912 if (xstate) {
2913 xcomp->comp_free(xstate);
2914 module_put(xcomp->owner);
2915 }
2916 if (rstate) {
2917 rcomp->decomp_free(rstate);
2918 module_put(rcomp->owner);
2919 }
2920 }
2921
2922 /* List of compressors. */
2923 static LIST_HEAD(compressor_list);
2924 static DEFINE_SPINLOCK(compressor_list_lock);
2925
2926 struct compressor_entry {
2927 struct list_head list;
2928 struct compressor *comp;
2929 };
2930
2931 static struct compressor_entry *
2932 find_comp_entry(int proto)
2933 {
2934 struct compressor_entry *ce;
2935
2936 list_for_each_entry(ce, &compressor_list, list) {
2937 if (ce->comp->compress_proto == proto)
2938 return ce;
2939 }
2940 return NULL;
2941 }
2942
2943 /* Register a compressor */
2944 int
2945 ppp_register_compressor(struct compressor *cp)
2946 {
2947 struct compressor_entry *ce;
2948 int ret;
2949 spin_lock(&compressor_list_lock);
2950 ret = -EEXIST;
2951 if (find_comp_entry(cp->compress_proto))
2952 goto out;
2953 ret = -ENOMEM;
2954 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2955 if (!ce)
2956 goto out;
2957 ret = 0;
2958 ce->comp = cp;
2959 list_add(&ce->list, &compressor_list);
2960 out:
2961 spin_unlock(&compressor_list_lock);
2962 return ret;
2963 }
2964
2965 /* Unregister a compressor */
2966 void
2967 ppp_unregister_compressor(struct compressor *cp)
2968 {
2969 struct compressor_entry *ce;
2970
2971 spin_lock(&compressor_list_lock);
2972 ce = find_comp_entry(cp->compress_proto);
2973 if (ce && ce->comp == cp) {
2974 list_del(&ce->list);
2975 kfree(ce);
2976 }
2977 spin_unlock(&compressor_list_lock);
2978 }
2979
2980 /* Find a compressor. */
2981 static struct compressor *
2982 find_compressor(int type)
2983 {
2984 struct compressor_entry *ce;
2985 struct compressor *cp = NULL;
2986
2987 spin_lock(&compressor_list_lock);
2988 ce = find_comp_entry(type);
2989 if (ce) {
2990 cp = ce->comp;
2991 if (!try_module_get(cp->owner))
2992 cp = NULL;
2993 }
2994 spin_unlock(&compressor_list_lock);
2995 return cp;
2996 }
2997
2998 /*
2999 * Miscelleneous stuff.
3000 */
3001
3002 static void
3003 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
3004 {
3005 struct slcompress *vj = ppp->vj;
3006
3007 memset(st, 0, sizeof(*st));
3008 st->p.ppp_ipackets = ppp->stats64.rx_packets;
3009 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
3010 st->p.ppp_ibytes = ppp->stats64.rx_bytes;
3011 st->p.ppp_opackets = ppp->stats64.tx_packets;
3012 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
3013 st->p.ppp_obytes = ppp->stats64.tx_bytes;
3014 if (!vj)
3015 return;
3016 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
3017 st->vj.vjs_compressed = vj->sls_o_compressed;
3018 st->vj.vjs_searches = vj->sls_o_searches;
3019 st->vj.vjs_misses = vj->sls_o_misses;
3020 st->vj.vjs_errorin = vj->sls_i_error;
3021 st->vj.vjs_tossed = vj->sls_i_tossed;
3022 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
3023 st->vj.vjs_compressedin = vj->sls_i_compressed;
3024 }
3025
3026 /*
3027 * Stuff for handling the lists of ppp units and channels
3028 * and for initialization.
3029 */
3030
3031 /*
3032 * Create a new ppp interface unit. Fails if it can't allocate memory
3033 * or if there is already a unit with the requested number.
3034 * unit == -1 means allocate a new number.
3035 */
3036 static int ppp_create_interface(struct net *net, struct file *file, int *unit)
3037 {
3038 struct ppp_config conf = {
3039 .file = file,
3040 .unit = *unit,
3041 .ifname_is_set = false,
3042 };
3043 struct net_device *dev;
3044 struct ppp *ppp;
3045 int err;
3046
3047 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_ENUM, ppp_setup);
3048 if (!dev) {
3049 err = -ENOMEM;
3050 goto err;
3051 }
3052 dev_net_set(dev, net);
3053 dev->rtnl_link_ops = &ppp_link_ops;
3054
3055 rtnl_lock();
3056
3057 err = ppp_dev_configure(net, dev, &conf);
3058 if (err < 0)
3059 goto err_dev;
3060 ppp = netdev_priv(dev);
3061 *unit = ppp->file.index;
3062
3063 rtnl_unlock();
3064
3065 return 0;
3066
3067 err_dev:
3068 rtnl_unlock();
3069 free_netdev(dev);
3070 err:
3071 return err;
3072 }
3073
3074 /*
3075 * Initialize a ppp_file structure.
3076 */
3077 static void
3078 init_ppp_file(struct ppp_file *pf, int kind)
3079 {
3080 pf->kind = kind;
3081 skb_queue_head_init(&pf->xq);
3082 skb_queue_head_init(&pf->rq);
3083 refcount_set(&pf->refcnt, 1);
3084 init_waitqueue_head(&pf->rwait);
3085 }
3086
3087 /*
3088 * Free the memory used by a ppp unit. This is only called once
3089 * there are no channels connected to the unit and no file structs
3090 * that reference the unit.
3091 */
3092 static void ppp_destroy_interface(struct ppp *ppp)
3093 {
3094 atomic_dec(&ppp_unit_count);
3095
3096 if (!ppp->file.dead || ppp->n_channels) {
3097 /* "can't happen" */
3098 netdev_err(ppp->dev, "ppp: destroying ppp struct %p "
3099 "but dead=%d n_channels=%d !\n",
3100 ppp, ppp->file.dead, ppp->n_channels);
3101 return;
3102 }
3103
3104 ppp_ccp_closed(ppp);
3105 if (ppp->vj) {
3106 slhc_free(ppp->vj);
3107 ppp->vj = NULL;
3108 }
3109 skb_queue_purge(&ppp->file.xq);
3110 skb_queue_purge(&ppp->file.rq);
3111 #ifdef CONFIG_PPP_MULTILINK
3112 skb_queue_purge(&ppp->mrq);
3113 #endif /* CONFIG_PPP_MULTILINK */
3114 #ifdef CONFIG_PPP_FILTER
3115 if (ppp->pass_filter) {
3116 bpf_prog_destroy(ppp->pass_filter);
3117 ppp->pass_filter = NULL;
3118 }
3119
3120 if (ppp->active_filter) {
3121 bpf_prog_destroy(ppp->active_filter);
3122 ppp->active_filter = NULL;
3123 }
3124 #endif /* CONFIG_PPP_FILTER */
3125
3126 kfree_skb(ppp->xmit_pending);
3127 free_percpu(ppp->xmit_recursion);
3128
3129 free_netdev(ppp->dev);
3130 }
3131
3132 /*
3133 * Locate an existing ppp unit.
3134 * The caller should have locked the all_ppp_mutex.
3135 */
3136 static struct ppp *
3137 ppp_find_unit(struct ppp_net *pn, int unit)
3138 {
3139 return unit_find(&pn->units_idr, unit);
3140 }
3141
3142 /*
3143 * Locate an existing ppp channel.
3144 * The caller should have locked the all_channels_lock.
3145 * First we look in the new_channels list, then in the
3146 * all_channels list. If found in the new_channels list,
3147 * we move it to the all_channels list. This is for speed
3148 * when we have a lot of channels in use.
3149 */
3150 static struct channel *
3151 ppp_find_channel(struct ppp_net *pn, int unit)
3152 {
3153 struct channel *pch;
3154
3155 list_for_each_entry(pch, &pn->new_channels, list) {
3156 if (pch->file.index == unit) {
3157 list_move(&pch->list, &pn->all_channels);
3158 return pch;
3159 }
3160 }
3161
3162 list_for_each_entry(pch, &pn->all_channels, list) {
3163 if (pch->file.index == unit)
3164 return pch;
3165 }
3166
3167 return NULL;
3168 }
3169
3170 /*
3171 * Connect a PPP channel to a PPP interface unit.
3172 */
3173 static int
3174 ppp_connect_channel(struct channel *pch, int unit)
3175 {
3176 struct ppp *ppp;
3177 struct ppp_net *pn;
3178 int ret = -ENXIO;
3179 int hdrlen;
3180
3181 pn = ppp_pernet(pch->chan_net);
3182
3183 mutex_lock(&pn->all_ppp_mutex);
3184 ppp = ppp_find_unit(pn, unit);
3185 if (!ppp)
3186 goto out;
3187 write_lock_bh(&pch->upl);
3188 ret = -EINVAL;
3189 if (pch->ppp)
3190 goto outl;
3191
3192 ppp_lock(ppp);
3193 spin_lock_bh(&pch->downl);
3194 if (!pch->chan) {
3195 /* Don't connect unregistered channels */
3196 spin_unlock_bh(&pch->downl);
3197 ppp_unlock(ppp);
3198 ret = -ENOTCONN;
3199 goto outl;
3200 }
3201 spin_unlock_bh(&pch->downl);
3202 if (pch->file.hdrlen > ppp->file.hdrlen)
3203 ppp->file.hdrlen = pch->file.hdrlen;
3204 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
3205 if (hdrlen > ppp->dev->hard_header_len)
3206 ppp->dev->hard_header_len = hdrlen;
3207 list_add_tail(&pch->clist, &ppp->channels);
3208 ++ppp->n_channels;
3209 pch->ppp = ppp;
3210 refcount_inc(&ppp->file.refcnt);
3211 ppp_unlock(ppp);
3212 ret = 0;
3213
3214 outl:
3215 write_unlock_bh(&pch->upl);
3216 out:
3217 mutex_unlock(&pn->all_ppp_mutex);
3218 return ret;
3219 }
3220
3221 /*
3222 * Disconnect a channel from its ppp unit.
3223 */
3224 static int
3225 ppp_disconnect_channel(struct channel *pch)
3226 {
3227 struct ppp *ppp;
3228 int err = -EINVAL;
3229
3230 write_lock_bh(&pch->upl);
3231 ppp = pch->ppp;
3232 pch->ppp = NULL;
3233 write_unlock_bh(&pch->upl);
3234 if (ppp) {
3235 /* remove it from the ppp unit's list */
3236 ppp_lock(ppp);
3237 list_del(&pch->clist);
3238 if (--ppp->n_channels == 0)
3239 wake_up_interruptible(&ppp->file.rwait);
3240 ppp_unlock(ppp);
3241 if (refcount_dec_and_test(&ppp->file.refcnt))
3242 ppp_destroy_interface(ppp);
3243 err = 0;
3244 }
3245 return err;
3246 }
3247
3248 /*
3249 * Free up the resources used by a ppp channel.
3250 */
3251 static void ppp_destroy_channel(struct channel *pch)
3252 {
3253 put_net(pch->chan_net);
3254 pch->chan_net = NULL;
3255
3256 atomic_dec(&channel_count);
3257
3258 if (!pch->file.dead) {
3259 /* "can't happen" */
3260 pr_err("ppp: destroying undead channel %p !\n", pch);
3261 return;
3262 }
3263 skb_queue_purge(&pch->file.xq);
3264 skb_queue_purge(&pch->file.rq);
3265 kfree(pch);
3266 }
3267
3268 static void __exit ppp_cleanup(void)
3269 {
3270 /* should never happen */
3271 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
3272 pr_err("PPP: removing module but units remain!\n");
3273 rtnl_link_unregister(&ppp_link_ops);
3274 unregister_chrdev(PPP_MAJOR, "ppp");
3275 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
3276 class_destroy(ppp_class);
3277 unregister_pernet_device(&ppp_net_ops);
3278 }
3279
3280 /*
3281 * Units handling. Caller must protect concurrent access
3282 * by holding all_ppp_mutex
3283 */
3284
3285 /* associate pointer with specified number */
3286 static int unit_set(struct idr *p, void *ptr, int n)
3287 {
3288 int unit;
3289
3290 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL);
3291 if (unit == -ENOSPC)
3292 unit = -EINVAL;
3293 return unit;
3294 }
3295
3296 /* get new free unit number and associate pointer with it */
3297 static int unit_get(struct idr *p, void *ptr)
3298 {
3299 return idr_alloc(p, ptr, 0, 0, GFP_KERNEL);
3300 }
3301
3302 /* put unit number back to a pool */
3303 static void unit_put(struct idr *p, int n)
3304 {
3305 idr_remove(p, n);
3306 }
3307
3308 /* get pointer associated with the number */
3309 static void *unit_find(struct idr *p, int n)
3310 {
3311 return idr_find(p, n);
3312 }
3313
3314 /* Module/initialization stuff */
3315
3316 module_init(ppp_init);
3317 module_exit(ppp_cleanup);
3318
3319 EXPORT_SYMBOL(ppp_register_net_channel);
3320 EXPORT_SYMBOL(ppp_register_channel);
3321 EXPORT_SYMBOL(ppp_unregister_channel);
3322 EXPORT_SYMBOL(ppp_channel_index);
3323 EXPORT_SYMBOL(ppp_unit_number);
3324 EXPORT_SYMBOL(ppp_dev_name);
3325 EXPORT_SYMBOL(ppp_input);
3326 EXPORT_SYMBOL(ppp_input_error);
3327 EXPORT_SYMBOL(ppp_output_wakeup);
3328 EXPORT_SYMBOL(ppp_register_compressor);
3329 EXPORT_SYMBOL(ppp_unregister_compressor);
3330 MODULE_LICENSE("GPL");
3331 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
3332 MODULE_ALIAS_RTNL_LINK("ppp");
3333 MODULE_ALIAS("devname:ppp");
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