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WIP FPC-III support
[linux/fpc-iii.git] / drivers / net / ppp / ppp_generic.c
blob09c27f7773f9592a44ba41b24712825d4b828913
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' and 'bridge' */
178 struct channel __rcu *bridge; /* "bridged" ppp channel */
179 #ifdef CONFIG_PPP_MULTILINK
180 u8 avail; /* flag used in multilink stuff */
181 u8 had_frag; /* >= 1 fragments have been sent */
182 u32 lastseq; /* MP: last sequence # received */
183 int speed; /* speed of the corresponding ppp channel*/
184 #endif /* CONFIG_PPP_MULTILINK */
185 };
186
187 struct ppp_config {
188 struct file *file;
189 s32 unit;
190 bool ifname_is_set;
191 };
192
193 /*
194 * SMP locking issues:
195 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
196 * list and the ppp.n_channels field, you need to take both locks
197 * before you modify them.
198 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
199 * channel.downl.
200 */
201
202 static DEFINE_MUTEX(ppp_mutex);
203 static atomic_t ppp_unit_count = ATOMIC_INIT(0);
204 static atomic_t channel_count = ATOMIC_INIT(0);
205
206 /* per-net private data for this module */
207 static unsigned int ppp_net_id __read_mostly;
208 struct ppp_net {
209 /* units to ppp mapping */
210 struct idr units_idr;
211
212 /*
213 * all_ppp_mutex protects the units_idr mapping.
214 * It also ensures that finding a ppp unit in the units_idr
215 * map and updating its file.refcnt field is atomic.
216 */
217 struct mutex all_ppp_mutex;
218
219 /* channels */
220 struct list_head all_channels;
221 struct list_head new_channels;
222 int last_channel_index;
223
224 /*
225 * all_channels_lock protects all_channels and
226 * last_channel_index, and the atomicity of find
227 * a channel and updating its file.refcnt field.
228 */
229 spinlock_t all_channels_lock;
230 };
231
232 /* Get the PPP protocol number from a skb */
233 #define PPP_PROTO(skb) get_unaligned_be16((skb)->data)
234
235 /* We limit the length of ppp->file.rq to this (arbitrary) value */
236 #define PPP_MAX_RQLEN 32
237
238 /*
239 * Maximum number of multilink fragments queued up.
240 * This has to be large enough to cope with the maximum latency of
241 * the slowest channel relative to the others. Strictly it should
242 * depend on the number of channels and their characteristics.
243 */
244 #define PPP_MP_MAX_QLEN 128
245
246 /* Multilink header bits. */
247 #define B 0x80 /* this fragment begins a packet */
248 #define E 0x40 /* this fragment ends a packet */
249
250 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */
251 #define seq_before(a, b) ((s32)((a) - (b)) < 0)
252 #define seq_after(a, b) ((s32)((a) - (b)) > 0)
253
254 /* Prototypes. */
255 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
256 struct file *file, unsigned int cmd, unsigned long arg);
257 static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb);
258 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
259 static void ppp_push(struct ppp *ppp);
260 static void ppp_channel_push(struct channel *pch);
261 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
262 struct channel *pch);
263 static void ppp_receive_error(struct ppp *ppp);
264 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
265 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
266 struct sk_buff *skb);
267 #ifdef CONFIG_PPP_MULTILINK
268 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
269 struct channel *pch);
270 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
271 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
272 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
273 #endif /* CONFIG_PPP_MULTILINK */
274 static int ppp_set_compress(struct ppp *ppp, struct ppp_option_data *data);
275 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
276 static void ppp_ccp_closed(struct ppp *ppp);
277 static struct compressor *find_compressor(int type);
278 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
279 static int ppp_create_interface(struct net *net, struct file *file, int *unit);
280 static void init_ppp_file(struct ppp_file *pf, int kind);
281 static void ppp_destroy_interface(struct ppp *ppp);
282 static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit);
283 static struct channel *ppp_find_channel(struct ppp_net *pn, int unit);
284 static int ppp_connect_channel(struct channel *pch, int unit);
285 static int ppp_disconnect_channel(struct channel *pch);
286 static void ppp_destroy_channel(struct channel *pch);
287 static int unit_get(struct idr *p, void *ptr);
288 static int unit_set(struct idr *p, void *ptr, int n);
289 static void unit_put(struct idr *p, int n);
290 static void *unit_find(struct idr *p, int n);
291 static void ppp_setup(struct net_device *dev);
292
293 static const struct net_device_ops ppp_netdev_ops;
294
295 static struct class *ppp_class;
296
297 /* per net-namespace data */
298 static inline struct ppp_net *ppp_pernet(struct net *net)
299 {
300 return net_generic(net, ppp_net_id);
301 }
302
303 /* Translates a PPP protocol number to a NP index (NP == network protocol) */
304 static inline int proto_to_npindex(int proto)
305 {
306 switch (proto) {
307 case PPP_IP:
308 return NP_IP;
309 case PPP_IPV6:
310 return NP_IPV6;
311 case PPP_IPX:
312 return NP_IPX;
313 case PPP_AT:
314 return NP_AT;
315 case PPP_MPLS_UC:
316 return NP_MPLS_UC;
317 case PPP_MPLS_MC:
318 return NP_MPLS_MC;
319 }
320 return -EINVAL;
321 }
322
323 /* Translates an NP index into a PPP protocol number */
324 static const int npindex_to_proto[NUM_NP] = {
325 PPP_IP,
326 PPP_IPV6,
327 PPP_IPX,
328 PPP_AT,
329 PPP_MPLS_UC,
330 PPP_MPLS_MC,
331 };
332
333 /* Translates an ethertype into an NP index */
334 static inline int ethertype_to_npindex(int ethertype)
335 {
336 switch (ethertype) {
337 case ETH_P_IP:
338 return NP_IP;
339 case ETH_P_IPV6:
340 return NP_IPV6;
341 case ETH_P_IPX:
342 return NP_IPX;
343 case ETH_P_PPPTALK:
344 case ETH_P_ATALK:
345 return NP_AT;
346 case ETH_P_MPLS_UC:
347 return NP_MPLS_UC;
348 case ETH_P_MPLS_MC:
349 return NP_MPLS_MC;
350 }
351 return -1;
352 }
353
354 /* Translates an NP index into an ethertype */
355 static const int npindex_to_ethertype[NUM_NP] = {
356 ETH_P_IP,
357 ETH_P_IPV6,
358 ETH_P_IPX,
359 ETH_P_PPPTALK,
360 ETH_P_MPLS_UC,
361 ETH_P_MPLS_MC,
362 };
363
364 /*
365 * Locking shorthand.
366 */
367 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
368 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
369 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
370 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
371 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
372 ppp_recv_lock(ppp); } while (0)
373 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
374 ppp_xmit_unlock(ppp); } while (0)
375
376 /*
377 * /dev/ppp device routines.
378 * The /dev/ppp device is used by pppd to control the ppp unit.
379 * It supports the read, write, ioctl and poll functions.
380 * Open instances of /dev/ppp can be in one of three states:
381 * unattached, attached to a ppp unit, or attached to a ppp channel.
382 */
383 static int ppp_open(struct inode *inode, struct file *file)
384 {
385 /*
386 * This could (should?) be enforced by the permissions on /dev/ppp.
387 */
388 if (!ns_capable(file->f_cred->user_ns, CAP_NET_ADMIN))
389 return -EPERM;
390 return 0;
391 }
392
393 static int ppp_release(struct inode *unused, struct file *file)
394 {
395 struct ppp_file *pf = file->private_data;
396 struct ppp *ppp;
397
398 if (pf) {
399 file->private_data = NULL;
400 if (pf->kind == INTERFACE) {
401 ppp = PF_TO_PPP(pf);
402 rtnl_lock();
403 if (file == ppp->owner)
404 unregister_netdevice(ppp->dev);
405 rtnl_unlock();
406 }
407 if (refcount_dec_and_test(&pf->refcnt)) {
408 switch (pf->kind) {
409 case INTERFACE:
410 ppp_destroy_interface(PF_TO_PPP(pf));
411 break;
412 case CHANNEL:
413 ppp_destroy_channel(PF_TO_CHANNEL(pf));
414 break;
415 }
416 }
417 }
418 return 0;
419 }
420
421 static ssize_t ppp_read(struct file *file, char __user *buf,
422 size_t count, loff_t *ppos)
423 {
424 struct ppp_file *pf = file->private_data;
425 DECLARE_WAITQUEUE(wait, current);
426 ssize_t ret;
427 struct sk_buff *skb = NULL;
428 struct iovec iov;
429 struct iov_iter to;
430
431 ret = count;
432
433 if (!pf)
434 return -ENXIO;
435 add_wait_queue(&pf->rwait, &wait);
436 for (;;) {
437 set_current_state(TASK_INTERRUPTIBLE);
438 skb = skb_dequeue(&pf->rq);
439 if (skb)
440 break;
441 ret = 0;
442 if (pf->dead)
443 break;
444 if (pf->kind == INTERFACE) {
445 /*
446 * Return 0 (EOF) on an interface that has no
447 * channels connected, unless it is looping
448 * network traffic (demand mode).
449 */
450 struct ppp *ppp = PF_TO_PPP(pf);
451
452 ppp_recv_lock(ppp);
453 if (ppp->n_channels == 0 &&
454 (ppp->flags & SC_LOOP_TRAFFIC) == 0) {
455 ppp_recv_unlock(ppp);
456 break;
457 }
458 ppp_recv_unlock(ppp);
459 }
460 ret = -EAGAIN;
461 if (file->f_flags & O_NONBLOCK)
462 break;
463 ret = -ERESTARTSYS;
464 if (signal_pending(current))
465 break;
466 schedule();
467 }
468 set_current_state(TASK_RUNNING);
469 remove_wait_queue(&pf->rwait, &wait);
470
471 if (!skb)
472 goto out;
473
474 ret = -EOVERFLOW;
475 if (skb->len > count)
476 goto outf;
477 ret = -EFAULT;
478 iov.iov_base = buf;
479 iov.iov_len = count;
480 iov_iter_init(&to, READ, &iov, 1, count);
481 if (skb_copy_datagram_iter(skb, 0, &to, skb->len))
482 goto outf;
483 ret = skb->len;
484
485 outf:
486 kfree_skb(skb);
487 out:
488 return ret;
489 }
490
491 static ssize_t ppp_write(struct file *file, const char __user *buf,
492 size_t count, loff_t *ppos)
493 {
494 struct ppp_file *pf = file->private_data;
495 struct sk_buff *skb;
496 ssize_t ret;
497
498 if (!pf)
499 return -ENXIO;
500 ret = -ENOMEM;
501 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
502 if (!skb)
503 goto out;
504 skb_reserve(skb, pf->hdrlen);
505 ret = -EFAULT;
506 if (copy_from_user(skb_put(skb, count), buf, count)) {
507 kfree_skb(skb);
508 goto out;
509 }
510
511 switch (pf->kind) {
512 case INTERFACE:
513 ppp_xmit_process(PF_TO_PPP(pf), skb);
514 break;
515 case CHANNEL:
516 skb_queue_tail(&pf->xq, skb);
517 ppp_channel_push(PF_TO_CHANNEL(pf));
518 break;
519 }
520
521 ret = count;
522
523 out:
524 return ret;
525 }
526
527 /* No kernel lock - fine */
528 static __poll_t ppp_poll(struct file *file, poll_table *wait)
529 {
530 struct ppp_file *pf = file->private_data;
531 __poll_t mask;
532
533 if (!pf)
534 return 0;
535 poll_wait(file, &pf->rwait, wait);
536 mask = EPOLLOUT | EPOLLWRNORM;
537 if (skb_peek(&pf->rq))
538 mask |= EPOLLIN | EPOLLRDNORM;
539 if (pf->dead)
540 mask |= EPOLLHUP;
541 else if (pf->kind == INTERFACE) {
542 /* see comment in ppp_read */
543 struct ppp *ppp = PF_TO_PPP(pf);
544
545 ppp_recv_lock(ppp);
546 if (ppp->n_channels == 0 &&
547 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
548 mask |= EPOLLIN | EPOLLRDNORM;
549 ppp_recv_unlock(ppp);
550 }
551
552 return mask;
553 }
554
555 #ifdef CONFIG_PPP_FILTER
556 static struct bpf_prog *get_filter(struct sock_fprog *uprog)
557 {
558 struct sock_fprog_kern fprog;
559 struct bpf_prog *res = NULL;
560 int err;
561
562 if (!uprog->len)
563 return NULL;
564
565 /* uprog->len is unsigned short, so no overflow here */
566 fprog.len = uprog->len;
567 fprog.filter = memdup_user(uprog->filter,
568 uprog->len * sizeof(struct sock_filter));
569 if (IS_ERR(fprog.filter))
570 return ERR_CAST(fprog.filter);
571
572 err = bpf_prog_create(&res, &fprog);
573 kfree(fprog.filter);
574
575 return err ? ERR_PTR(err) : res;
576 }
577
578 static struct bpf_prog *ppp_get_filter(struct sock_fprog __user *p)
579 {
580 struct sock_fprog uprog;
581
582 if (copy_from_user(&uprog, p, sizeof(struct sock_fprog)))
583 return ERR_PTR(-EFAULT);
584 return get_filter(&uprog);
585 }
586
587 #ifdef CONFIG_COMPAT
588 struct sock_fprog32 {
589 unsigned short len;
590 compat_caddr_t filter;
591 };
592
593 #define PPPIOCSPASS32 _IOW('t', 71, struct sock_fprog32)
594 #define PPPIOCSACTIVE32 _IOW('t', 70, struct sock_fprog32)
595
596 static struct bpf_prog *compat_ppp_get_filter(struct sock_fprog32 __user *p)
597 {
598 struct sock_fprog32 uprog32;
599 struct sock_fprog uprog;
600
601 if (copy_from_user(&uprog32, p, sizeof(struct sock_fprog32)))
602 return ERR_PTR(-EFAULT);
603 uprog.len = uprog32.len;
604 uprog.filter = compat_ptr(uprog32.filter);
605 return get_filter(&uprog);
606 }
607 #endif
608 #endif
609
610 /* Bridge one PPP channel to another.
611 * When two channels are bridged, ppp_input on one channel is redirected to
612 * the other's ops->start_xmit handler.
613 * In order to safely bridge channels we must reject channels which are already
614 * part of a bridge instance, or which form part of an existing unit.
615 * Once successfully bridged, each channel holds a reference on the other
616 * to prevent it being freed while the bridge is extant.
617 */
618 static int ppp_bridge_channels(struct channel *pch, struct channel *pchb)
619 {
620 write_lock_bh(&pch->upl);
621 if (pch->ppp ||
622 rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl))) {
623 write_unlock_bh(&pch->upl);
624 return -EALREADY;
625 }
626 rcu_assign_pointer(pch->bridge, pchb);
627 write_unlock_bh(&pch->upl);
628
629 write_lock_bh(&pchb->upl);
630 if (pchb->ppp ||
631 rcu_dereference_protected(pchb->bridge, lockdep_is_held(&pchb->upl))) {
632 write_unlock_bh(&pchb->upl);
633 goto err_unset;
634 }
635 rcu_assign_pointer(pchb->bridge, pch);
636 write_unlock_bh(&pchb->upl);
637
638 refcount_inc(&pch->file.refcnt);
639 refcount_inc(&pchb->file.refcnt);
640
641 return 0;
642
643 err_unset:
644 write_lock_bh(&pch->upl);
645 RCU_INIT_POINTER(pch->bridge, NULL);
646 write_unlock_bh(&pch->upl);
647 synchronize_rcu();
648 return -EALREADY;
649 }
650
651 static int ppp_unbridge_channels(struct channel *pch)
652 {
653 struct channel *pchb, *pchbb;
654
655 write_lock_bh(&pch->upl);
656 pchb = rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl));
657 if (!pchb) {
658 write_unlock_bh(&pch->upl);
659 return -EINVAL;
660 }
661 RCU_INIT_POINTER(pch->bridge, NULL);
662 write_unlock_bh(&pch->upl);
663
664 /* Only modify pchb if phcb->bridge points back to pch.
665 * If not, it implies that there has been a race unbridging (and possibly
666 * even rebridging) pchb. We should leave pchb alone to avoid either a
667 * refcount underflow, or breaking another established bridge instance.
668 */
669 write_lock_bh(&pchb->upl);
670 pchbb = rcu_dereference_protected(pchb->bridge, lockdep_is_held(&pchb->upl));
671 if (pchbb == pch)
672 RCU_INIT_POINTER(pchb->bridge, NULL);
673 write_unlock_bh(&pchb->upl);
674
675 synchronize_rcu();
676
677 if (pchbb == pch)
678 if (refcount_dec_and_test(&pch->file.refcnt))
679 ppp_destroy_channel(pch);
680
681 if (refcount_dec_and_test(&pchb->file.refcnt))
682 ppp_destroy_channel(pchb);
683
684 return 0;
685 }
686
687 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
688 {
689 struct ppp_file *pf;
690 struct ppp *ppp;
691 int err = -EFAULT, val, val2, i;
692 struct ppp_idle32 idle32;
693 struct ppp_idle64 idle64;
694 struct npioctl npi;
695 int unit, cflags;
696 struct slcompress *vj;
697 void __user *argp = (void __user *)arg;
698 int __user *p = argp;
699
700 mutex_lock(&ppp_mutex);
701
702 pf = file->private_data;
703 if (!pf) {
704 err = ppp_unattached_ioctl(current->nsproxy->net_ns,
705 pf, file, cmd, arg);
706 goto out;
707 }
708
709 if (cmd == PPPIOCDETACH) {
710 /*
711 * PPPIOCDETACH is no longer supported as it was heavily broken,
712 * and is only known to have been used by pppd older than
713 * ppp-2.4.2 (released November 2003).
714 */
715 pr_warn_once("%s (%d) used obsolete PPPIOCDETACH ioctl\n",
716 current->comm, current->pid);
717 err = -EINVAL;
718 goto out;
719 }
720
721 if (pf->kind == CHANNEL) {
722 struct channel *pch, *pchb;
723 struct ppp_channel *chan;
724 struct ppp_net *pn;
725
726 pch = PF_TO_CHANNEL(pf);
727
728 switch (cmd) {
729 case PPPIOCCONNECT:
730 if (get_user(unit, p))
731 break;
732 err = ppp_connect_channel(pch, unit);
733 break;
734
735 case PPPIOCDISCONN:
736 err = ppp_disconnect_channel(pch);
737 break;
738
739 case PPPIOCBRIDGECHAN:
740 if (get_user(unit, p))
741 break;
742 err = -ENXIO;
743 pn = ppp_pernet(current->nsproxy->net_ns);
744 spin_lock_bh(&pn->all_channels_lock);
745 pchb = ppp_find_channel(pn, unit);
746 /* Hold a reference to prevent pchb being freed while
747 * we establish the bridge.
748 */
749 if (pchb)
750 refcount_inc(&pchb->file.refcnt);
751 spin_unlock_bh(&pn->all_channels_lock);
752 if (!pchb)
753 break;
754 err = ppp_bridge_channels(pch, pchb);
755 /* Drop earlier refcount now bridge establishment is complete */
756 if (refcount_dec_and_test(&pchb->file.refcnt))
757 ppp_destroy_channel(pchb);
758 break;
759
760 case PPPIOCUNBRIDGECHAN:
761 err = ppp_unbridge_channels(pch);
762 break;
763
764 default:
765 down_read(&pch->chan_sem);
766 chan = pch->chan;
767 err = -ENOTTY;
768 if (chan && chan->ops->ioctl)
769 err = chan->ops->ioctl(chan, cmd, arg);
770 up_read(&pch->chan_sem);
771 }
772 goto out;
773 }
774
775 if (pf->kind != INTERFACE) {
776 /* can't happen */
777 pr_err("PPP: not interface or channel??\n");
778 err = -EINVAL;
779 goto out;
780 }
781
782 ppp = PF_TO_PPP(pf);
783 switch (cmd) {
784 case PPPIOCSMRU:
785 if (get_user(val, p))
786 break;
787 ppp->mru = val;
788 err = 0;
789 break;
790
791 case PPPIOCSFLAGS:
792 if (get_user(val, p))
793 break;
794 ppp_lock(ppp);
795 cflags = ppp->flags & ~val;
796 #ifdef CONFIG_PPP_MULTILINK
797 if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK))
798 ppp->nextseq = 0;
799 #endif
800 ppp->flags = val & SC_FLAG_BITS;
801 ppp_unlock(ppp);
802 if (cflags & SC_CCP_OPEN)
803 ppp_ccp_closed(ppp);
804 err = 0;
805 break;
806
807 case PPPIOCGFLAGS:
808 val = ppp->flags | ppp->xstate | ppp->rstate;
809 if (put_user(val, p))
810 break;
811 err = 0;
812 break;
813
814 case PPPIOCSCOMPRESS:
815 {
816 struct ppp_option_data data;
817 if (copy_from_user(&data, argp, sizeof(data)))
818 err = -EFAULT;
819 else
820 err = ppp_set_compress(ppp, &data);
821 break;
822 }
823 case PPPIOCGUNIT:
824 if (put_user(ppp->file.index, p))
825 break;
826 err = 0;
827 break;
828
829 case PPPIOCSDEBUG:
830 if (get_user(val, p))
831 break;
832 ppp->debug = val;
833 err = 0;
834 break;
835
836 case PPPIOCGDEBUG:
837 if (put_user(ppp->debug, p))
838 break;
839 err = 0;
840 break;
841
842 case PPPIOCGIDLE32:
843 idle32.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
844 idle32.recv_idle = (jiffies - ppp->last_recv) / HZ;
845 if (copy_to_user(argp, &idle32, sizeof(idle32)))
846 break;
847 err = 0;
848 break;
849
850 case PPPIOCGIDLE64:
851 idle64.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
852 idle64.recv_idle = (jiffies - ppp->last_recv) / HZ;
853 if (copy_to_user(argp, &idle64, sizeof(idle64)))
854 break;
855 err = 0;
856 break;
857
858 case PPPIOCSMAXCID:
859 if (get_user(val, p))
860 break;
861 val2 = 15;
862 if ((val >> 16) != 0) {
863 val2 = val >> 16;
864 val &= 0xffff;
865 }
866 vj = slhc_init(val2+1, val+1);
867 if (IS_ERR(vj)) {
868 err = PTR_ERR(vj);
869 break;
870 }
871 ppp_lock(ppp);
872 if (ppp->vj)
873 slhc_free(ppp->vj);
874 ppp->vj = vj;
875 ppp_unlock(ppp);
876 err = 0;
877 break;
878
879 case PPPIOCGNPMODE:
880 case PPPIOCSNPMODE:
881 if (copy_from_user(&npi, argp, sizeof(npi)))
882 break;
883 err = proto_to_npindex(npi.protocol);
884 if (err < 0)
885 break;
886 i = err;
887 if (cmd == PPPIOCGNPMODE) {
888 err = -EFAULT;
889 npi.mode = ppp->npmode[i];
890 if (copy_to_user(argp, &npi, sizeof(npi)))
891 break;
892 } else {
893 ppp->npmode[i] = npi.mode;
894 /* we may be able to transmit more packets now (??) */
895 netif_wake_queue(ppp->dev);
896 }
897 err = 0;
898 break;
899
900 #ifdef CONFIG_PPP_FILTER
901 case PPPIOCSPASS:
902 case PPPIOCSACTIVE:
903 {
904 struct bpf_prog *filter = ppp_get_filter(argp);
905 struct bpf_prog **which;
906
907 if (IS_ERR(filter)) {
908 err = PTR_ERR(filter);
909 break;
910 }
911 if (cmd == PPPIOCSPASS)
912 which = &ppp->pass_filter;
913 else
914 which = &ppp->active_filter;
915 ppp_lock(ppp);
916 if (*which)
917 bpf_prog_destroy(*which);
918 *which = filter;
919 ppp_unlock(ppp);
920 err = 0;
921 break;
922 }
923 #endif /* CONFIG_PPP_FILTER */
924
925 #ifdef CONFIG_PPP_MULTILINK
926 case PPPIOCSMRRU:
927 if (get_user(val, p))
928 break;
929 ppp_recv_lock(ppp);
930 ppp->mrru = val;
931 ppp_recv_unlock(ppp);
932 err = 0;
933 break;
934 #endif /* CONFIG_PPP_MULTILINK */
935
936 default:
937 err = -ENOTTY;
938 }
939
940 out:
941 mutex_unlock(&ppp_mutex);
942
943 return err;
944 }
945
946 #ifdef CONFIG_COMPAT
947 struct ppp_option_data32 {
948 compat_uptr_t ptr;
949 u32 length;
950 compat_int_t transmit;
951 };
952 #define PPPIOCSCOMPRESS32 _IOW('t', 77, struct ppp_option_data32)
953
954 static long ppp_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
955 {
956 struct ppp_file *pf;
957 int err = -ENOIOCTLCMD;
958 void __user *argp = (void __user *)arg;
959
960 mutex_lock(&ppp_mutex);
961
962 pf = file->private_data;
963 if (pf && pf->kind == INTERFACE) {
964 struct ppp *ppp = PF_TO_PPP(pf);
965 switch (cmd) {
966 #ifdef CONFIG_PPP_FILTER
967 case PPPIOCSPASS32:
968 case PPPIOCSACTIVE32:
969 {
970 struct bpf_prog *filter = compat_ppp_get_filter(argp);
971 struct bpf_prog **which;
972
973 if (IS_ERR(filter)) {
974 err = PTR_ERR(filter);
975 break;
976 }
977 if (cmd == PPPIOCSPASS32)
978 which = &ppp->pass_filter;
979 else
980 which = &ppp->active_filter;
981 ppp_lock(ppp);
982 if (*which)
983 bpf_prog_destroy(*which);
984 *which = filter;
985 ppp_unlock(ppp);
986 err = 0;
987 break;
988 }
989 #endif /* CONFIG_PPP_FILTER */
990 case PPPIOCSCOMPRESS32:
991 {
992 struct ppp_option_data32 data32;
993 if (copy_from_user(&data32, argp, sizeof(data32))) {
994 err = -EFAULT;
995 } else {
996 struct ppp_option_data data = {
997 .ptr = compat_ptr(data32.ptr),
998 .length = data32.length,
999 .transmit = data32.transmit
1000 };
1001 err = ppp_set_compress(ppp, &data);
1002 }
1003 break;
1004 }
1005 }
1006 }
1007 mutex_unlock(&ppp_mutex);
1008
1009 /* all other commands have compatible arguments */
1010 if (err == -ENOIOCTLCMD)
1011 err = ppp_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
1012
1013 return err;
1014 }
1015 #endif
1016
1017 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
1018 struct file *file, unsigned int cmd, unsigned long arg)
1019 {
1020 int unit, err = -EFAULT;
1021 struct ppp *ppp;
1022 struct channel *chan;
1023 struct ppp_net *pn;
1024 int __user *p = (int __user *)arg;
1025
1026 switch (cmd) {
1027 case PPPIOCNEWUNIT:
1028 /* Create a new ppp unit */
1029 if (get_user(unit, p))
1030 break;
1031 err = ppp_create_interface(net, file, &unit);
1032 if (err < 0)
1033 break;
1034
1035 err = -EFAULT;
1036 if (put_user(unit, p))
1037 break;
1038 err = 0;
1039 break;
1040
1041 case PPPIOCATTACH:
1042 /* Attach to an existing ppp unit */
1043 if (get_user(unit, p))
1044 break;
1045 err = -ENXIO;
1046 pn = ppp_pernet(net);
1047 mutex_lock(&pn->all_ppp_mutex);
1048 ppp = ppp_find_unit(pn, unit);
1049 if (ppp) {
1050 refcount_inc(&ppp->file.refcnt);
1051 file->private_data = &ppp->file;
1052 err = 0;
1053 }
1054 mutex_unlock(&pn->all_ppp_mutex);
1055 break;
1056
1057 case PPPIOCATTCHAN:
1058 if (get_user(unit, p))
1059 break;
1060 err = -ENXIO;
1061 pn = ppp_pernet(net);
1062 spin_lock_bh(&pn->all_channels_lock);
1063 chan = ppp_find_channel(pn, unit);
1064 if (chan) {
1065 refcount_inc(&chan->file.refcnt);
1066 file->private_data = &chan->file;
1067 err = 0;
1068 }
1069 spin_unlock_bh(&pn->all_channels_lock);
1070 break;
1071
1072 default:
1073 err = -ENOTTY;
1074 }
1075
1076 return err;
1077 }
1078
1079 static const struct file_operations ppp_device_fops = {
1080 .owner = THIS_MODULE,
1081 .read = ppp_read,
1082 .write = ppp_write,
1083 .poll = ppp_poll,
1084 .unlocked_ioctl = ppp_ioctl,
1085 #ifdef CONFIG_COMPAT
1086 .compat_ioctl = ppp_compat_ioctl,
1087 #endif
1088 .open = ppp_open,
1089 .release = ppp_release,
1090 .llseek = noop_llseek,
1091 };
1092
1093 static __net_init int ppp_init_net(struct net *net)
1094 {
1095 struct ppp_net *pn = net_generic(net, ppp_net_id);
1096
1097 idr_init(&pn->units_idr);
1098 mutex_init(&pn->all_ppp_mutex);
1099
1100 INIT_LIST_HEAD(&pn->all_channels);
1101 INIT_LIST_HEAD(&pn->new_channels);
1102
1103 spin_lock_init(&pn->all_channels_lock);
1104
1105 return 0;
1106 }
1107
1108 static __net_exit void ppp_exit_net(struct net *net)
1109 {
1110 struct ppp_net *pn = net_generic(net, ppp_net_id);
1111 struct net_device *dev;
1112 struct net_device *aux;
1113 struct ppp *ppp;
1114 LIST_HEAD(list);
1115 int id;
1116
1117 rtnl_lock();
1118 for_each_netdev_safe(net, dev, aux) {
1119 if (dev->netdev_ops == &ppp_netdev_ops)
1120 unregister_netdevice_queue(dev, &list);
1121 }
1122
1123 idr_for_each_entry(&pn->units_idr, ppp, id)
1124 /* Skip devices already unregistered by previous loop */
1125 if (!net_eq(dev_net(ppp->dev), net))
1126 unregister_netdevice_queue(ppp->dev, &list);
1127
1128 unregister_netdevice_many(&list);
1129 rtnl_unlock();
1130
1131 mutex_destroy(&pn->all_ppp_mutex);
1132 idr_destroy(&pn->units_idr);
1133 WARN_ON_ONCE(!list_empty(&pn->all_channels));
1134 WARN_ON_ONCE(!list_empty(&pn->new_channels));
1135 }
1136
1137 static struct pernet_operations ppp_net_ops = {
1138 .init = ppp_init_net,
1139 .exit = ppp_exit_net,
1140 .id = &ppp_net_id,
1141 .size = sizeof(struct ppp_net),
1142 };
1143
1144 static int ppp_unit_register(struct ppp *ppp, int unit, bool ifname_is_set)
1145 {
1146 struct ppp_net *pn = ppp_pernet(ppp->ppp_net);
1147 int ret;
1148
1149 mutex_lock(&pn->all_ppp_mutex);
1150
1151 if (unit < 0) {
1152 ret = unit_get(&pn->units_idr, ppp);
1153 if (ret < 0)
1154 goto err;
1155 } else {
1156 /* Caller asked for a specific unit number. Fail with -EEXIST
1157 * if unavailable. For backward compatibility, return -EEXIST
1158 * too if idr allocation fails; this makes pppd retry without
1159 * requesting a specific unit number.
1160 */
1161 if (unit_find(&pn->units_idr, unit)) {
1162 ret = -EEXIST;
1163 goto err;
1164 }
1165 ret = unit_set(&pn->units_idr, ppp, unit);
1166 if (ret < 0) {
1167 /* Rewrite error for backward compatibility */
1168 ret = -EEXIST;
1169 goto err;
1170 }
1171 }
1172 ppp->file.index = ret;
1173
1174 if (!ifname_is_set)
1175 snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ppp->file.index);
1176
1177 mutex_unlock(&pn->all_ppp_mutex);
1178
1179 ret = register_netdevice(ppp->dev);
1180 if (ret < 0)
1181 goto err_unit;
1182
1183 atomic_inc(&ppp_unit_count);
1184
1185 return 0;
1186
1187 err_unit:
1188 mutex_lock(&pn->all_ppp_mutex);
1189 unit_put(&pn->units_idr, ppp->file.index);
1190 err:
1191 mutex_unlock(&pn->all_ppp_mutex);
1192
1193 return ret;
1194 }
1195
1196 static int ppp_dev_configure(struct net *src_net, struct net_device *dev,
1197 const struct ppp_config *conf)
1198 {
1199 struct ppp *ppp = netdev_priv(dev);
1200 int indx;
1201 int err;
1202 int cpu;
1203
1204 ppp->dev = dev;
1205 ppp->ppp_net = src_net;
1206 ppp->mru = PPP_MRU;
1207 ppp->owner = conf->file;
1208
1209 init_ppp_file(&ppp->file, INTERFACE);
1210 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
1211
1212 for (indx = 0; indx < NUM_NP; ++indx)
1213 ppp->npmode[indx] = NPMODE_PASS;
1214 INIT_LIST_HEAD(&ppp->channels);
1215 spin_lock_init(&ppp->rlock);
1216 spin_lock_init(&ppp->wlock);
1217
1218 ppp->xmit_recursion = alloc_percpu(int);
1219 if (!ppp->xmit_recursion) {
1220 err = -ENOMEM;
1221 goto err1;
1222 }
1223 for_each_possible_cpu(cpu)
1224 (*per_cpu_ptr(ppp->xmit_recursion, cpu)) = 0;
1225
1226 #ifdef CONFIG_PPP_MULTILINK
1227 ppp->minseq = -1;
1228 skb_queue_head_init(&ppp->mrq);
1229 #endif /* CONFIG_PPP_MULTILINK */
1230 #ifdef CONFIG_PPP_FILTER
1231 ppp->pass_filter = NULL;
1232 ppp->active_filter = NULL;
1233 #endif /* CONFIG_PPP_FILTER */
1234
1235 err = ppp_unit_register(ppp, conf->unit, conf->ifname_is_set);
1236 if (err < 0)
1237 goto err2;
1238
1239 conf->file->private_data = &ppp->file;
1240
1241 return 0;
1242 err2:
1243 free_percpu(ppp->xmit_recursion);
1244 err1:
1245 return err;
1246 }
1247
1248 static const struct nla_policy ppp_nl_policy[IFLA_PPP_MAX + 1] = {
1249 [IFLA_PPP_DEV_FD] = { .type = NLA_S32 },
1250 };
1251
1252 static int ppp_nl_validate(struct nlattr *tb[], struct nlattr *data[],
1253 struct netlink_ext_ack *extack)
1254 {
1255 if (!data)
1256 return -EINVAL;
1257
1258 if (!data[IFLA_PPP_DEV_FD])
1259 return -EINVAL;
1260 if (nla_get_s32(data[IFLA_PPP_DEV_FD]) < 0)
1261 return -EBADF;
1262
1263 return 0;
1264 }
1265
1266 static int ppp_nl_newlink(struct net *src_net, struct net_device *dev,
1267 struct nlattr *tb[], struct nlattr *data[],
1268 struct netlink_ext_ack *extack)
1269 {
1270 struct ppp_config conf = {
1271 .unit = -1,
1272 .ifname_is_set = true,
1273 };
1274 struct file *file;
1275 int err;
1276
1277 file = fget(nla_get_s32(data[IFLA_PPP_DEV_FD]));
1278 if (!file)
1279 return -EBADF;
1280
1281 /* rtnl_lock is already held here, but ppp_create_interface() locks
1282 * ppp_mutex before holding rtnl_lock. Using mutex_trylock() avoids
1283 * possible deadlock due to lock order inversion, at the cost of
1284 * pushing the problem back to userspace.
1285 */
1286 if (!mutex_trylock(&ppp_mutex)) {
1287 err = -EBUSY;
1288 goto out;
1289 }
1290
1291 if (file->f_op != &ppp_device_fops || file->private_data) {
1292 err = -EBADF;
1293 goto out_unlock;
1294 }
1295
1296 conf.file = file;
1297
1298 /* Don't use device name generated by the rtnetlink layer when ifname
1299 * isn't specified. Let ppp_dev_configure() set the device name using
1300 * the PPP unit identifer as suffix (i.e. ppp<unit_id>). This allows
1301 * userspace to infer the device name using to the PPPIOCGUNIT ioctl.
1302 */
1303 if (!tb[IFLA_IFNAME])
1304 conf.ifname_is_set = false;
1305
1306 err = ppp_dev_configure(src_net, dev, &conf);
1307
1308 out_unlock:
1309 mutex_unlock(&ppp_mutex);
1310 out:
1311 fput(file);
1312
1313 return err;
1314 }
1315
1316 static void ppp_nl_dellink(struct net_device *dev, struct list_head *head)
1317 {
1318 unregister_netdevice_queue(dev, head);
1319 }
1320
1321 static size_t ppp_nl_get_size(const struct net_device *dev)
1322 {
1323 return 0;
1324 }
1325
1326 static int ppp_nl_fill_info(struct sk_buff *skb, const struct net_device *dev)
1327 {
1328 return 0;
1329 }
1330
1331 static struct net *ppp_nl_get_link_net(const struct net_device *dev)
1332 {
1333 struct ppp *ppp = netdev_priv(dev);
1334
1335 return ppp->ppp_net;
1336 }
1337
1338 static struct rtnl_link_ops ppp_link_ops __read_mostly = {
1339 .kind = "ppp",
1340 .maxtype = IFLA_PPP_MAX,
1341 .policy = ppp_nl_policy,
1342 .priv_size = sizeof(struct ppp),
1343 .setup = ppp_setup,
1344 .validate = ppp_nl_validate,
1345 .newlink = ppp_nl_newlink,
1346 .dellink = ppp_nl_dellink,
1347 .get_size = ppp_nl_get_size,
1348 .fill_info = ppp_nl_fill_info,
1349 .get_link_net = ppp_nl_get_link_net,
1350 };
1351
1352 #define PPP_MAJOR 108
1353
1354 /* Called at boot time if ppp is compiled into the kernel,
1355 or at module load time (from init_module) if compiled as a module. */
1356 static int __init ppp_init(void)
1357 {
1358 int err;
1359
1360 pr_info("PPP generic driver version " PPP_VERSION "\n");
1361
1362 err = register_pernet_device(&ppp_net_ops);
1363 if (err) {
1364 pr_err("failed to register PPP pernet device (%d)\n", err);
1365 goto out;
1366 }
1367
1368 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
1369 if (err) {
1370 pr_err("failed to register PPP device (%d)\n", err);
1371 goto out_net;
1372 }
1373
1374 ppp_class = class_create(THIS_MODULE, "ppp");
1375 if (IS_ERR(ppp_class)) {
1376 err = PTR_ERR(ppp_class);
1377 goto out_chrdev;
1378 }
1379
1380 err = rtnl_link_register(&ppp_link_ops);
1381 if (err) {
1382 pr_err("failed to register rtnetlink PPP handler\n");
1383 goto out_class;
1384 }
1385
1386 /* not a big deal if we fail here :-) */
1387 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
1388
1389 return 0;
1390
1391 out_class:
1392 class_destroy(ppp_class);
1393 out_chrdev:
1394 unregister_chrdev(PPP_MAJOR, "ppp");
1395 out_net:
1396 unregister_pernet_device(&ppp_net_ops);
1397 out:
1398 return err;
1399 }
1400
1401 /*
1402 * Network interface unit routines.
1403 */
1404 static netdev_tx_t
1405 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
1406 {
1407 struct ppp *ppp = netdev_priv(dev);
1408 int npi, proto;
1409 unsigned char *pp;
1410
1411 npi = ethertype_to_npindex(ntohs(skb->protocol));
1412 if (npi < 0)
1413 goto outf;
1414
1415 /* Drop, accept or reject the packet */
1416 switch (ppp->npmode[npi]) {
1417 case NPMODE_PASS:
1418 break;
1419 case NPMODE_QUEUE:
1420 /* it would be nice to have a way to tell the network
1421 system to queue this one up for later. */
1422 goto outf;
1423 case NPMODE_DROP:
1424 case NPMODE_ERROR:
1425 goto outf;
1426 }
1427
1428 /* Put the 2-byte PPP protocol number on the front,
1429 making sure there is room for the address and control fields. */
1430 if (skb_cow_head(skb, PPP_HDRLEN))
1431 goto outf;
1432
1433 pp = skb_push(skb, 2);
1434 proto = npindex_to_proto[npi];
1435 put_unaligned_be16(proto, pp);
1436
1437 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, dev_net(dev)));
1438 ppp_xmit_process(ppp, skb);
1439
1440 return NETDEV_TX_OK;
1441
1442 outf:
1443 kfree_skb(skb);
1444 ++dev->stats.tx_dropped;
1445 return NETDEV_TX_OK;
1446 }
1447
1448 static int
1449 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1450 {
1451 struct ppp *ppp = netdev_priv(dev);
1452 int err = -EFAULT;
1453 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
1454 struct ppp_stats stats;
1455 struct ppp_comp_stats cstats;
1456 char *vers;
1457
1458 switch (cmd) {
1459 case SIOCGPPPSTATS:
1460 ppp_get_stats(ppp, &stats);
1461 if (copy_to_user(addr, &stats, sizeof(stats)))
1462 break;
1463 err = 0;
1464 break;
1465
1466 case SIOCGPPPCSTATS:
1467 memset(&cstats, 0, sizeof(cstats));
1468 if (ppp->xc_state)
1469 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
1470 if (ppp->rc_state)
1471 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
1472 if (copy_to_user(addr, &cstats, sizeof(cstats)))
1473 break;
1474 err = 0;
1475 break;
1476
1477 case SIOCGPPPVER:
1478 vers = PPP_VERSION;
1479 if (copy_to_user(addr, vers, strlen(vers) + 1))
1480 break;
1481 err = 0;
1482 break;
1483
1484 default:
1485 err = -EINVAL;
1486 }
1487
1488 return err;
1489 }
1490
1491 static void
1492 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64)
1493 {
1494 struct ppp *ppp = netdev_priv(dev);
1495
1496 ppp_recv_lock(ppp);
1497 stats64->rx_packets = ppp->stats64.rx_packets;
1498 stats64->rx_bytes = ppp->stats64.rx_bytes;
1499 ppp_recv_unlock(ppp);
1500
1501 ppp_xmit_lock(ppp);
1502 stats64->tx_packets = ppp->stats64.tx_packets;
1503 stats64->tx_bytes = ppp->stats64.tx_bytes;
1504 ppp_xmit_unlock(ppp);
1505
1506 stats64->rx_errors = dev->stats.rx_errors;
1507 stats64->tx_errors = dev->stats.tx_errors;
1508 stats64->rx_dropped = dev->stats.rx_dropped;
1509 stats64->tx_dropped = dev->stats.tx_dropped;
1510 stats64->rx_length_errors = dev->stats.rx_length_errors;
1511 }
1512
1513 static int ppp_dev_init(struct net_device *dev)
1514 {
1515 struct ppp *ppp;
1516
1517 netdev_lockdep_set_classes(dev);
1518
1519 ppp = netdev_priv(dev);
1520 /* Let the netdevice take a reference on the ppp file. This ensures
1521 * that ppp_destroy_interface() won't run before the device gets
1522 * unregistered.
1523 */
1524 refcount_inc(&ppp->file.refcnt);
1525
1526 return 0;
1527 }
1528
1529 static void ppp_dev_uninit(struct net_device *dev)
1530 {
1531 struct ppp *ppp = netdev_priv(dev);
1532 struct ppp_net *pn = ppp_pernet(ppp->ppp_net);
1533
1534 ppp_lock(ppp);
1535 ppp->closing = 1;
1536 ppp_unlock(ppp);
1537
1538 mutex_lock(&pn->all_ppp_mutex);
1539 unit_put(&pn->units_idr, ppp->file.index);
1540 mutex_unlock(&pn->all_ppp_mutex);
1541
1542 ppp->owner = NULL;
1543
1544 ppp->file.dead = 1;
1545 wake_up_interruptible(&ppp->file.rwait);
1546 }
1547
1548 static void ppp_dev_priv_destructor(struct net_device *dev)
1549 {
1550 struct ppp *ppp;
1551
1552 ppp = netdev_priv(dev);
1553 if (refcount_dec_and_test(&ppp->file.refcnt))
1554 ppp_destroy_interface(ppp);
1555 }
1556
1557 static const struct net_device_ops ppp_netdev_ops = {
1558 .ndo_init = ppp_dev_init,
1559 .ndo_uninit = ppp_dev_uninit,
1560 .ndo_start_xmit = ppp_start_xmit,
1561 .ndo_do_ioctl = ppp_net_ioctl,
1562 .ndo_get_stats64 = ppp_get_stats64,
1563 };
1564
1565 static struct device_type ppp_type = {
1566 .name = "ppp",
1567 };
1568
1569 static void ppp_setup(struct net_device *dev)
1570 {
1571 dev->netdev_ops = &ppp_netdev_ops;
1572 SET_NETDEV_DEVTYPE(dev, &ppp_type);
1573
1574 dev->features |= NETIF_F_LLTX;
1575
1576 dev->hard_header_len = PPP_HDRLEN;
1577 dev->mtu = PPP_MRU;
1578 dev->addr_len = 0;
1579 dev->tx_queue_len = 3;
1580 dev->type = ARPHRD_PPP;
1581 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1582 dev->priv_destructor = ppp_dev_priv_destructor;
1583 netif_keep_dst(dev);
1584 }
1585
1586 /*
1587 * Transmit-side routines.
1588 */
1589
1590 /* Called to do any work queued up on the transmit side that can now be done */
1591 static void __ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb)
1592 {
1593 ppp_xmit_lock(ppp);
1594 if (!ppp->closing) {
1595 ppp_push(ppp);
1596
1597 if (skb)
1598 skb_queue_tail(&ppp->file.xq, skb);
1599 while (!ppp->xmit_pending &&
1600 (skb = skb_dequeue(&ppp->file.xq)))
1601 ppp_send_frame(ppp, skb);
1602 /* If there's no work left to do, tell the core net
1603 code that we can accept some more. */
1604 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1605 netif_wake_queue(ppp->dev);
1606 else
1607 netif_stop_queue(ppp->dev);
1608 } else {
1609 kfree_skb(skb);
1610 }
1611 ppp_xmit_unlock(ppp);
1612 }
1613
1614 static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb)
1615 {
1616 local_bh_disable();
1617
1618 if (unlikely(*this_cpu_ptr(ppp->xmit_recursion)))
1619 goto err;
1620
1621 (*this_cpu_ptr(ppp->xmit_recursion))++;
1622 __ppp_xmit_process(ppp, skb);
1623 (*this_cpu_ptr(ppp->xmit_recursion))--;
1624
1625 local_bh_enable();
1626
1627 return;
1628
1629 err:
1630 local_bh_enable();
1631
1632 kfree_skb(skb);
1633
1634 if (net_ratelimit())
1635 netdev_err(ppp->dev, "recursion detected\n");
1636 }
1637
1638 static inline struct sk_buff *
1639 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1640 {
1641 struct sk_buff *new_skb;
1642 int len;
1643 int new_skb_size = ppp->dev->mtu +
1644 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1645 int compressor_skb_size = ppp->dev->mtu +
1646 ppp->xcomp->comp_extra + PPP_HDRLEN;
1647 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1648 if (!new_skb) {
1649 if (net_ratelimit())
1650 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n");
1651 return NULL;
1652 }
1653 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1654 skb_reserve(new_skb,
1655 ppp->dev->hard_header_len - PPP_HDRLEN);
1656
1657 /* compressor still expects A/C bytes in hdr */
1658 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1659 new_skb->data, skb->len + 2,
1660 compressor_skb_size);
1661 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1662 consume_skb(skb);
1663 skb = new_skb;
1664 skb_put(skb, len);
1665 skb_pull(skb, 2); /* pull off A/C bytes */
1666 } else if (len == 0) {
1667 /* didn't compress, or CCP not up yet */
1668 consume_skb(new_skb);
1669 new_skb = skb;
1670 } else {
1671 /*
1672 * (len < 0)
1673 * MPPE requires that we do not send unencrypted
1674 * frames. The compressor will return -1 if we
1675 * should drop the frame. We cannot simply test
1676 * the compress_proto because MPPE and MPPC share
1677 * the same number.
1678 */
1679 if (net_ratelimit())
1680 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n");
1681 kfree_skb(skb);
1682 consume_skb(new_skb);
1683 new_skb = NULL;
1684 }
1685 return new_skb;
1686 }
1687
1688 /*
1689 * Compress and send a frame.
1690 * The caller should have locked the xmit path,
1691 * and xmit_pending should be 0.
1692 */
1693 static void
1694 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1695 {
1696 int proto = PPP_PROTO(skb);
1697 struct sk_buff *new_skb;
1698 int len;
1699 unsigned char *cp;
1700
1701 if (proto < 0x8000) {
1702 #ifdef CONFIG_PPP_FILTER
1703 /* check if we should pass this packet */
1704 /* the filter instructions are constructed assuming
1705 a four-byte PPP header on each packet */
1706 *(u8 *)skb_push(skb, 2) = 1;
1707 if (ppp->pass_filter &&
1708 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
1709 if (ppp->debug & 1)
1710 netdev_printk(KERN_DEBUG, ppp->dev,
1711 "PPP: outbound frame "
1712 "not passed\n");
1713 kfree_skb(skb);
1714 return;
1715 }
1716 /* if this packet passes the active filter, record the time */
1717 if (!(ppp->active_filter &&
1718 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
1719 ppp->last_xmit = jiffies;
1720 skb_pull(skb, 2);
1721 #else
1722 /* for data packets, record the time */
1723 ppp->last_xmit = jiffies;
1724 #endif /* CONFIG_PPP_FILTER */
1725 }
1726
1727 ++ppp->stats64.tx_packets;
1728 ppp->stats64.tx_bytes += skb->len - 2;
1729
1730 switch (proto) {
1731 case PPP_IP:
1732 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1733 break;
1734 /* try to do VJ TCP header compression */
1735 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1736 GFP_ATOMIC);
1737 if (!new_skb) {
1738 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n");
1739 goto drop;
1740 }
1741 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1742 cp = skb->data + 2;
1743 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1744 new_skb->data + 2, &cp,
1745 !(ppp->flags & SC_NO_TCP_CCID));
1746 if (cp == skb->data + 2) {
1747 /* didn't compress */
1748 consume_skb(new_skb);
1749 } else {
1750 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1751 proto = PPP_VJC_COMP;
1752 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1753 } else {
1754 proto = PPP_VJC_UNCOMP;
1755 cp[0] = skb->data[2];
1756 }
1757 consume_skb(skb);
1758 skb = new_skb;
1759 cp = skb_put(skb, len + 2);
1760 cp[0] = 0;
1761 cp[1] = proto;
1762 }
1763 break;
1764
1765 case PPP_CCP:
1766 /* peek at outbound CCP frames */
1767 ppp_ccp_peek(ppp, skb, 0);
1768 break;
1769 }
1770
1771 /* try to do packet compression */
1772 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state &&
1773 proto != PPP_LCP && proto != PPP_CCP) {
1774 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1775 if (net_ratelimit())
1776 netdev_err(ppp->dev,
1777 "ppp: compression required but "
1778 "down - pkt dropped.\n");
1779 goto drop;
1780 }
1781 skb = pad_compress_skb(ppp, skb);
1782 if (!skb)
1783 goto drop;
1784 }
1785
1786 /*
1787 * If we are waiting for traffic (demand dialling),
1788 * queue it up for pppd to receive.
1789 */
1790 if (ppp->flags & SC_LOOP_TRAFFIC) {
1791 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1792 goto drop;
1793 skb_queue_tail(&ppp->file.rq, skb);
1794 wake_up_interruptible(&ppp->file.rwait);
1795 return;
1796 }
1797
1798 ppp->xmit_pending = skb;
1799 ppp_push(ppp);
1800 return;
1801
1802 drop:
1803 kfree_skb(skb);
1804 ++ppp->dev->stats.tx_errors;
1805 }
1806
1807 /*
1808 * Try to send the frame in xmit_pending.
1809 * The caller should have the xmit path locked.
1810 */
1811 static void
1812 ppp_push(struct ppp *ppp)
1813 {
1814 struct list_head *list;
1815 struct channel *pch;
1816 struct sk_buff *skb = ppp->xmit_pending;
1817
1818 if (!skb)
1819 return;
1820
1821 list = &ppp->channels;
1822 if (list_empty(list)) {
1823 /* nowhere to send the packet, just drop it */
1824 ppp->xmit_pending = NULL;
1825 kfree_skb(skb);
1826 return;
1827 }
1828
1829 if ((ppp->flags & SC_MULTILINK) == 0) {
1830 /* not doing multilink: send it down the first channel */
1831 list = list->next;
1832 pch = list_entry(list, struct channel, clist);
1833
1834 spin_lock(&pch->downl);
1835 if (pch->chan) {
1836 if (pch->chan->ops->start_xmit(pch->chan, skb))
1837 ppp->xmit_pending = NULL;
1838 } else {
1839 /* channel got unregistered */
1840 kfree_skb(skb);
1841 ppp->xmit_pending = NULL;
1842 }
1843 spin_unlock(&pch->downl);
1844 return;
1845 }
1846
1847 #ifdef CONFIG_PPP_MULTILINK
1848 /* Multilink: fragment the packet over as many links
1849 as can take the packet at the moment. */
1850 if (!ppp_mp_explode(ppp, skb))
1851 return;
1852 #endif /* CONFIG_PPP_MULTILINK */
1853
1854 ppp->xmit_pending = NULL;
1855 kfree_skb(skb);
1856 }
1857
1858 #ifdef CONFIG_PPP_MULTILINK
1859 static bool mp_protocol_compress __read_mostly = true;
1860 module_param(mp_protocol_compress, bool, 0644);
1861 MODULE_PARM_DESC(mp_protocol_compress,
1862 "compress protocol id in multilink fragments");
1863
1864 /*
1865 * Divide a packet to be transmitted into fragments and
1866 * send them out the individual links.
1867 */
1868 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1869 {
1870 int len, totlen;
1871 int i, bits, hdrlen, mtu;
1872 int flen;
1873 int navail, nfree, nzero;
1874 int nbigger;
1875 int totspeed;
1876 int totfree;
1877 unsigned char *p, *q;
1878 struct list_head *list;
1879 struct channel *pch;
1880 struct sk_buff *frag;
1881 struct ppp_channel *chan;
1882
1883 totspeed = 0; /*total bitrate of the bundle*/
1884 nfree = 0; /* # channels which have no packet already queued */
1885 navail = 0; /* total # of usable channels (not deregistered) */
1886 nzero = 0; /* number of channels with zero speed associated*/
1887 totfree = 0; /*total # of channels available and
1888 *having no queued packets before
1889 *starting the fragmentation*/
1890
1891 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1892 i = 0;
1893 list_for_each_entry(pch, &ppp->channels, clist) {
1894 if (pch->chan) {
1895 pch->avail = 1;
1896 navail++;
1897 pch->speed = pch->chan->speed;
1898 } else {
1899 pch->avail = 0;
1900 }
1901 if (pch->avail) {
1902 if (skb_queue_empty(&pch->file.xq) ||
1903 !pch->had_frag) {
1904 if (pch->speed == 0)
1905 nzero++;
1906 else
1907 totspeed += pch->speed;
1908
1909 pch->avail = 2;
1910 ++nfree;
1911 ++totfree;
1912 }
1913 if (!pch->had_frag && i < ppp->nxchan)
1914 ppp->nxchan = i;
1915 }
1916 ++i;
1917 }
1918 /*
1919 * Don't start sending this packet unless at least half of
1920 * the channels are free. This gives much better TCP
1921 * performance if we have a lot of channels.
1922 */
1923 if (nfree == 0 || nfree < navail / 2)
1924 return 0; /* can't take now, leave it in xmit_pending */
1925
1926 /* Do protocol field compression */
1927 p = skb->data;
1928 len = skb->len;
1929 if (*p == 0 && mp_protocol_compress) {
1930 ++p;
1931 --len;
1932 }
1933
1934 totlen = len;
1935 nbigger = len % nfree;
1936
1937 /* skip to the channel after the one we last used
1938 and start at that one */
1939 list = &ppp->channels;
1940 for (i = 0; i < ppp->nxchan; ++i) {
1941 list = list->next;
1942 if (list == &ppp->channels) {
1943 i = 0;
1944 break;
1945 }
1946 }
1947
1948 /* create a fragment for each channel */
1949 bits = B;
1950 while (len > 0) {
1951 list = list->next;
1952 if (list == &ppp->channels) {
1953 i = 0;
1954 continue;
1955 }
1956 pch = list_entry(list, struct channel, clist);
1957 ++i;
1958 if (!pch->avail)
1959 continue;
1960
1961 /*
1962 * Skip this channel if it has a fragment pending already and
1963 * we haven't given a fragment to all of the free channels.
1964 */
1965 if (pch->avail == 1) {
1966 if (nfree > 0)
1967 continue;
1968 } else {
1969 pch->avail = 1;
1970 }
1971
1972 /* check the channel's mtu and whether it is still attached. */
1973 spin_lock(&pch->downl);
1974 if (pch->chan == NULL) {
1975 /* can't use this channel, it's being deregistered */
1976 if (pch->speed == 0)
1977 nzero--;
1978 else
1979 totspeed -= pch->speed;
1980
1981 spin_unlock(&pch->downl);
1982 pch->avail = 0;
1983 totlen = len;
1984 totfree--;
1985 nfree--;
1986 if (--navail == 0)
1987 break;
1988 continue;
1989 }
1990
1991 /*
1992 *if the channel speed is not set divide
1993 *the packet evenly among the free channels;
1994 *otherwise divide it according to the speed
1995 *of the channel we are going to transmit on
1996 */
1997 flen = len;
1998 if (nfree > 0) {
1999 if (pch->speed == 0) {
2000 flen = len/nfree;
2001 if (nbigger > 0) {
2002 flen++;
2003 nbigger--;
2004 }
2005 } else {
2006 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
2007 ((totspeed*totfree)/pch->speed)) - hdrlen;
2008 if (nbigger > 0) {
2009 flen += ((totfree - nzero)*pch->speed)/totspeed;
2010 nbigger -= ((totfree - nzero)*pch->speed)/
2011 totspeed;
2012 }
2013 }
2014 nfree--;
2015 }
2016
2017 /*
2018 *check if we are on the last channel or
2019 *we exceded the length of the data to
2020 *fragment
2021 */
2022 if ((nfree <= 0) || (flen > len))
2023 flen = len;
2024 /*
2025 *it is not worth to tx on slow channels:
2026 *in that case from the resulting flen according to the
2027 *above formula will be equal or less than zero.
2028 *Skip the channel in this case
2029 */
2030 if (flen <= 0) {
2031 pch->avail = 2;
2032 spin_unlock(&pch->downl);
2033 continue;
2034 }
2035
2036 /*
2037 * hdrlen includes the 2-byte PPP protocol field, but the
2038 * MTU counts only the payload excluding the protocol field.
2039 * (RFC1661 Section 2)
2040 */
2041 mtu = pch->chan->mtu - (hdrlen - 2);
2042 if (mtu < 4)
2043 mtu = 4;
2044 if (flen > mtu)
2045 flen = mtu;
2046 if (flen == len)
2047 bits |= E;
2048 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
2049 if (!frag)
2050 goto noskb;
2051 q = skb_put(frag, flen + hdrlen);
2052
2053 /* make the MP header */
2054 put_unaligned_be16(PPP_MP, q);
2055 if (ppp->flags & SC_MP_XSHORTSEQ) {
2056 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
2057 q[3] = ppp->nxseq;
2058 } else {
2059 q[2] = bits;
2060 q[3] = ppp->nxseq >> 16;
2061 q[4] = ppp->nxseq >> 8;
2062 q[5] = ppp->nxseq;
2063 }
2064
2065 memcpy(q + hdrlen, p, flen);
2066
2067 /* try to send it down the channel */
2068 chan = pch->chan;
2069 if (!skb_queue_empty(&pch->file.xq) ||
2070 !chan->ops->start_xmit(chan, frag))
2071 skb_queue_tail(&pch->file.xq, frag);
2072 pch->had_frag = 1;
2073 p += flen;
2074 len -= flen;
2075 ++ppp->nxseq;
2076 bits = 0;
2077 spin_unlock(&pch->downl);
2078 }
2079 ppp->nxchan = i;
2080
2081 return 1;
2082
2083 noskb:
2084 spin_unlock(&pch->downl);
2085 if (ppp->debug & 1)
2086 netdev_err(ppp->dev, "PPP: no memory (fragment)\n");
2087 ++ppp->dev->stats.tx_errors;
2088 ++ppp->nxseq;
2089 return 1; /* abandon the frame */
2090 }
2091 #endif /* CONFIG_PPP_MULTILINK */
2092
2093 /* Try to send data out on a channel */
2094 static void __ppp_channel_push(struct channel *pch)
2095 {
2096 struct sk_buff *skb;
2097 struct ppp *ppp;
2098
2099 spin_lock(&pch->downl);
2100 if (pch->chan) {
2101 while (!skb_queue_empty(&pch->file.xq)) {
2102 skb = skb_dequeue(&pch->file.xq);
2103 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
2104 /* put the packet back and try again later */
2105 skb_queue_head(&pch->file.xq, skb);
2106 break;
2107 }
2108 }
2109 } else {
2110 /* channel got deregistered */
2111 skb_queue_purge(&pch->file.xq);
2112 }
2113 spin_unlock(&pch->downl);
2114 /* see if there is anything from the attached unit to be sent */
2115 if (skb_queue_empty(&pch->file.xq)) {
2116 ppp = pch->ppp;
2117 if (ppp)
2118 __ppp_xmit_process(ppp, NULL);
2119 }
2120 }
2121
2122 static void ppp_channel_push(struct channel *pch)
2123 {
2124 read_lock_bh(&pch->upl);
2125 if (pch->ppp) {
2126 (*this_cpu_ptr(pch->ppp->xmit_recursion))++;
2127 __ppp_channel_push(pch);
2128 (*this_cpu_ptr(pch->ppp->xmit_recursion))--;
2129 } else {
2130 __ppp_channel_push(pch);
2131 }
2132 read_unlock_bh(&pch->upl);
2133 }
2134
2135 /*
2136 * Receive-side routines.
2137 */
2138
2139 struct ppp_mp_skb_parm {
2140 u32 sequence;
2141 u8 BEbits;
2142 };
2143 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb))
2144
2145 static inline void
2146 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
2147 {
2148 ppp_recv_lock(ppp);
2149 if (!ppp->closing)
2150 ppp_receive_frame(ppp, skb, pch);
2151 else
2152 kfree_skb(skb);
2153 ppp_recv_unlock(ppp);
2154 }
2155
2156 /**
2157 * __ppp_decompress_proto - Decompress protocol field, slim version.
2158 * @skb: Socket buffer where protocol field should be decompressed. It must have
2159 * at least 1 byte of head room and 1 byte of linear data. First byte of
2160 * data must be a protocol field byte.
2161 *
2162 * Decompress protocol field in PPP header if it's compressed, e.g. when
2163 * Protocol-Field-Compression (PFC) was negotiated. No checks w.r.t. skb data
2164 * length are done in this function.
2165 */
2166 static void __ppp_decompress_proto(struct sk_buff *skb)
2167 {
2168 if (skb->data[0] & 0x01)
2169 *(u8 *)skb_push(skb, 1) = 0x00;
2170 }
2171
2172 /**
2173 * ppp_decompress_proto - Check skb data room and decompress protocol field.
2174 * @skb: Socket buffer where protocol field should be decompressed. First byte
2175 * of data must be a protocol field byte.
2176 *
2177 * Decompress protocol field in PPP header if it's compressed, e.g. when
2178 * Protocol-Field-Compression (PFC) was negotiated. This function also makes
2179 * sure that skb data room is sufficient for Protocol field, before and after
2180 * decompression.
2181 *
2182 * Return: true - decompressed successfully, false - not enough room in skb.
2183 */
2184 static bool ppp_decompress_proto(struct sk_buff *skb)
2185 {
2186 /* At least one byte should be present (if protocol is compressed) */
2187 if (!pskb_may_pull(skb, 1))
2188 return false;
2189
2190 __ppp_decompress_proto(skb);
2191
2192 /* Protocol field should occupy 2 bytes when not compressed */
2193 return pskb_may_pull(skb, 2);
2194 }
2195
2196 /* Attempt to handle a frame via. a bridged channel, if one exists.
2197 * If the channel is bridged, the frame is consumed by the bridge.
2198 * If not, the caller must handle the frame by normal recv mechanisms.
2199 * Returns true if the frame is consumed, false otherwise.
2200 */
2201 static bool ppp_channel_bridge_input(struct channel *pch, struct sk_buff *skb)
2202 {
2203 struct channel *pchb;
2204
2205 rcu_read_lock();
2206 pchb = rcu_dereference(pch->bridge);
2207 if (!pchb)
2208 goto out_rcu;
2209
2210 spin_lock(&pchb->downl);
2211 if (!pchb->chan) {
2212 /* channel got unregistered */
2213 kfree_skb(skb);
2214 goto outl;
2215 }
2216
2217 skb_scrub_packet(skb, !net_eq(pch->chan_net, pchb->chan_net));
2218 if (!pchb->chan->ops->start_xmit(pchb->chan, skb))
2219 kfree_skb(skb);
2220
2221 outl:
2222 spin_unlock(&pchb->downl);
2223 out_rcu:
2224 rcu_read_unlock();
2225
2226 /* If pchb is set then we've consumed the packet */
2227 return !!pchb;
2228 }
2229
2230 void
2231 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
2232 {
2233 struct channel *pch = chan->ppp;
2234 int proto;
2235
2236 if (!pch) {
2237 kfree_skb(skb);
2238 return;
2239 }
2240
2241 /* If the channel is bridged, transmit via. bridge */
2242 if (ppp_channel_bridge_input(pch, skb))
2243 return;
2244
2245 read_lock_bh(&pch->upl);
2246 if (!ppp_decompress_proto(skb)) {
2247 kfree_skb(skb);
2248 if (pch->ppp) {
2249 ++pch->ppp->dev->stats.rx_length_errors;
2250 ppp_receive_error(pch->ppp);
2251 }
2252 goto done;
2253 }
2254
2255 proto = PPP_PROTO(skb);
2256 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
2257 /* put it on the channel queue */
2258 skb_queue_tail(&pch->file.rq, skb);
2259 /* drop old frames if queue too long */
2260 while (pch->file.rq.qlen > PPP_MAX_RQLEN &&
2261 (skb = skb_dequeue(&pch->file.rq)))
2262 kfree_skb(skb);
2263 wake_up_interruptible(&pch->file.rwait);
2264 } else {
2265 ppp_do_recv(pch->ppp, skb, pch);
2266 }
2267
2268 done:
2269 read_unlock_bh(&pch->upl);
2270 }
2271
2272 /* Put a 0-length skb in the receive queue as an error indication */
2273 void
2274 ppp_input_error(struct ppp_channel *chan, int code)
2275 {
2276 struct channel *pch = chan->ppp;
2277 struct sk_buff *skb;
2278
2279 if (!pch)
2280 return;
2281
2282 read_lock_bh(&pch->upl);
2283 if (pch->ppp) {
2284 skb = alloc_skb(0, GFP_ATOMIC);
2285 if (skb) {
2286 skb->len = 0; /* probably unnecessary */
2287 skb->cb[0] = code;
2288 ppp_do_recv(pch->ppp, skb, pch);
2289 }
2290 }
2291 read_unlock_bh(&pch->upl);
2292 }
2293
2294 /*
2295 * We come in here to process a received frame.
2296 * The receive side of the ppp unit is locked.
2297 */
2298 static void
2299 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
2300 {
2301 /* note: a 0-length skb is used as an error indication */
2302 if (skb->len > 0) {
2303 skb_checksum_complete_unset(skb);
2304 #ifdef CONFIG_PPP_MULTILINK
2305 /* XXX do channel-level decompression here */
2306 if (PPP_PROTO(skb) == PPP_MP)
2307 ppp_receive_mp_frame(ppp, skb, pch);
2308 else
2309 #endif /* CONFIG_PPP_MULTILINK */
2310 ppp_receive_nonmp_frame(ppp, skb);
2311 } else {
2312 kfree_skb(skb);
2313 ppp_receive_error(ppp);
2314 }
2315 }
2316
2317 static void
2318 ppp_receive_error(struct ppp *ppp)
2319 {
2320 ++ppp->dev->stats.rx_errors;
2321 if (ppp->vj)
2322 slhc_toss(ppp->vj);
2323 }
2324
2325 static void
2326 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
2327 {
2328 struct sk_buff *ns;
2329 int proto, len, npi;
2330
2331 /*
2332 * Decompress the frame, if compressed.
2333 * Note that some decompressors need to see uncompressed frames
2334 * that come in as well as compressed frames.
2335 */
2336 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) &&
2337 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
2338 skb = ppp_decompress_frame(ppp, skb);
2339
2340 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
2341 goto err;
2342
2343 /* At this point the "Protocol" field MUST be decompressed, either in
2344 * ppp_input(), ppp_decompress_frame() or in ppp_receive_mp_frame().
2345 */
2346 proto = PPP_PROTO(skb);
2347 switch (proto) {
2348 case PPP_VJC_COMP:
2349 /* decompress VJ compressed packets */
2350 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
2351 goto err;
2352
2353 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
2354 /* copy to a new sk_buff with more tailroom */
2355 ns = dev_alloc_skb(skb->len + 128);
2356 if (!ns) {
2357 netdev_err(ppp->dev, "PPP: no memory "
2358 "(VJ decomp)\n");
2359 goto err;
2360 }
2361 skb_reserve(ns, 2);
2362 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
2363 consume_skb(skb);
2364 skb = ns;
2365 }
2366 else
2367 skb->ip_summed = CHECKSUM_NONE;
2368
2369 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
2370 if (len <= 0) {
2371 netdev_printk(KERN_DEBUG, ppp->dev,
2372 "PPP: VJ decompression error\n");
2373 goto err;
2374 }
2375 len += 2;
2376 if (len > skb->len)
2377 skb_put(skb, len - skb->len);
2378 else if (len < skb->len)
2379 skb_trim(skb, len);
2380 proto = PPP_IP;
2381 break;
2382
2383 case PPP_VJC_UNCOMP:
2384 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
2385 goto err;
2386
2387 /* Until we fix the decompressor need to make sure
2388 * data portion is linear.
2389 */
2390 if (!pskb_may_pull(skb, skb->len))
2391 goto err;
2392
2393 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
2394 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n");
2395 goto err;
2396 }
2397 proto = PPP_IP;
2398 break;
2399
2400 case PPP_CCP:
2401 ppp_ccp_peek(ppp, skb, 1);
2402 break;
2403 }
2404
2405 ++ppp->stats64.rx_packets;
2406 ppp->stats64.rx_bytes += skb->len - 2;
2407
2408 npi = proto_to_npindex(proto);
2409 if (npi < 0) {
2410 /* control or unknown frame - pass it to pppd */
2411 skb_queue_tail(&ppp->file.rq, skb);
2412 /* limit queue length by dropping old frames */
2413 while (ppp->file.rq.qlen > PPP_MAX_RQLEN &&
2414 (skb = skb_dequeue(&ppp->file.rq)))
2415 kfree_skb(skb);
2416 /* wake up any process polling or blocking on read */
2417 wake_up_interruptible(&ppp->file.rwait);
2418
2419 } else {
2420 /* network protocol frame - give it to the kernel */
2421
2422 #ifdef CONFIG_PPP_FILTER
2423 /* check if the packet passes the pass and active filters */
2424 /* the filter instructions are constructed assuming
2425 a four-byte PPP header on each packet */
2426 if (ppp->pass_filter || ppp->active_filter) {
2427 if (skb_unclone(skb, GFP_ATOMIC))
2428 goto err;
2429
2430 *(u8 *)skb_push(skb, 2) = 0;
2431 if (ppp->pass_filter &&
2432 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
2433 if (ppp->debug & 1)
2434 netdev_printk(KERN_DEBUG, ppp->dev,
2435 "PPP: inbound frame "
2436 "not passed\n");
2437 kfree_skb(skb);
2438 return;
2439 }
2440 if (!(ppp->active_filter &&
2441 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
2442 ppp->last_recv = jiffies;
2443 __skb_pull(skb, 2);
2444 } else
2445 #endif /* CONFIG_PPP_FILTER */
2446 ppp->last_recv = jiffies;
2447
2448 if ((ppp->dev->flags & IFF_UP) == 0 ||
2449 ppp->npmode[npi] != NPMODE_PASS) {
2450 kfree_skb(skb);
2451 } else {
2452 /* chop off protocol */
2453 skb_pull_rcsum(skb, 2);
2454 skb->dev = ppp->dev;
2455 skb->protocol = htons(npindex_to_ethertype[npi]);
2456 skb_reset_mac_header(skb);
2457 skb_scrub_packet(skb, !net_eq(ppp->ppp_net,
2458 dev_net(ppp->dev)));
2459 netif_rx(skb);
2460 }
2461 }
2462 return;
2463
2464 err:
2465 kfree_skb(skb);
2466 ppp_receive_error(ppp);
2467 }
2468
2469 static struct sk_buff *
2470 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
2471 {
2472 int proto = PPP_PROTO(skb);
2473 struct sk_buff *ns;
2474 int len;
2475
2476 /* Until we fix all the decompressor's need to make sure
2477 * data portion is linear.
2478 */
2479 if (!pskb_may_pull(skb, skb->len))
2480 goto err;
2481
2482 if (proto == PPP_COMP) {
2483 int obuff_size;
2484
2485 switch(ppp->rcomp->compress_proto) {
2486 case CI_MPPE:
2487 obuff_size = ppp->mru + PPP_HDRLEN + 1;
2488 break;
2489 default:
2490 obuff_size = ppp->mru + PPP_HDRLEN;
2491 break;
2492 }
2493
2494 ns = dev_alloc_skb(obuff_size);
2495 if (!ns) {
2496 netdev_err(ppp->dev, "ppp_decompress_frame: "
2497 "no memory\n");
2498 goto err;
2499 }
2500 /* the decompressor still expects the A/C bytes in the hdr */
2501 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
2502 skb->len + 2, ns->data, obuff_size);
2503 if (len < 0) {
2504 /* Pass the compressed frame to pppd as an
2505 error indication. */
2506 if (len == DECOMP_FATALERROR)
2507 ppp->rstate |= SC_DC_FERROR;
2508 kfree_skb(ns);
2509 goto err;
2510 }
2511
2512 consume_skb(skb);
2513 skb = ns;
2514 skb_put(skb, len);
2515 skb_pull(skb, 2); /* pull off the A/C bytes */
2516
2517 /* Don't call __ppp_decompress_proto() here, but instead rely on
2518 * corresponding algo (mppe/bsd/deflate) to decompress it.
2519 */
2520 } else {
2521 /* Uncompressed frame - pass to decompressor so it
2522 can update its dictionary if necessary. */
2523 if (ppp->rcomp->incomp)
2524 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
2525 skb->len + 2);
2526 }
2527
2528 return skb;
2529
2530 err:
2531 ppp->rstate |= SC_DC_ERROR;
2532 ppp_receive_error(ppp);
2533 return skb;
2534 }
2535
2536 #ifdef CONFIG_PPP_MULTILINK
2537 /*
2538 * Receive a multilink frame.
2539 * We put it on the reconstruction queue and then pull off
2540 * as many completed frames as we can.
2541 */
2542 static void
2543 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
2544 {
2545 u32 mask, seq;
2546 struct channel *ch;
2547 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
2548
2549 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
2550 goto err; /* no good, throw it away */
2551
2552 /* Decode sequence number and begin/end bits */
2553 if (ppp->flags & SC_MP_SHORTSEQ) {
2554 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
2555 mask = 0xfff;
2556 } else {
2557 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
2558 mask = 0xffffff;
2559 }
2560 PPP_MP_CB(skb)->BEbits = skb->data[2];
2561 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
2562
2563 /*
2564 * Do protocol ID decompression on the first fragment of each packet.
2565 * We have to do that here, because ppp_receive_nonmp_frame() expects
2566 * decompressed protocol field.
2567 */
2568 if (PPP_MP_CB(skb)->BEbits & B)
2569 __ppp_decompress_proto(skb);
2570
2571 /*
2572 * Expand sequence number to 32 bits, making it as close
2573 * as possible to ppp->minseq.
2574 */
2575 seq |= ppp->minseq & ~mask;
2576 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
2577 seq += mask + 1;
2578 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
2579 seq -= mask + 1; /* should never happen */
2580 PPP_MP_CB(skb)->sequence = seq;
2581 pch->lastseq = seq;
2582
2583 /*
2584 * If this packet comes before the next one we were expecting,
2585 * drop it.
2586 */
2587 if (seq_before(seq, ppp->nextseq)) {
2588 kfree_skb(skb);
2589 ++ppp->dev->stats.rx_dropped;
2590 ppp_receive_error(ppp);
2591 return;
2592 }
2593
2594 /*
2595 * Reevaluate minseq, the minimum over all channels of the
2596 * last sequence number received on each channel. Because of
2597 * the increasing sequence number rule, we know that any fragment
2598 * before `minseq' which hasn't arrived is never going to arrive.
2599 * The list of channels can't change because we have the receive
2600 * side of the ppp unit locked.
2601 */
2602 list_for_each_entry(ch, &ppp->channels, clist) {
2603 if (seq_before(ch->lastseq, seq))
2604 seq = ch->lastseq;
2605 }
2606 if (seq_before(ppp->minseq, seq))
2607 ppp->minseq = seq;
2608
2609 /* Put the fragment on the reconstruction queue */
2610 ppp_mp_insert(ppp, skb);
2611
2612 /* If the queue is getting long, don't wait any longer for packets
2613 before the start of the queue. */
2614 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
2615 struct sk_buff *mskb = skb_peek(&ppp->mrq);
2616 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence))
2617 ppp->minseq = PPP_MP_CB(mskb)->sequence;
2618 }
2619
2620 /* Pull completed packets off the queue and receive them. */
2621 while ((skb = ppp_mp_reconstruct(ppp))) {
2622 if (pskb_may_pull(skb, 2))
2623 ppp_receive_nonmp_frame(ppp, skb);
2624 else {
2625 ++ppp->dev->stats.rx_length_errors;
2626 kfree_skb(skb);
2627 ppp_receive_error(ppp);
2628 }
2629 }
2630
2631 return;
2632
2633 err:
2634 kfree_skb(skb);
2635 ppp_receive_error(ppp);
2636 }
2637
2638 /*
2639 * Insert a fragment on the MP reconstruction queue.
2640 * The queue is ordered by increasing sequence number.
2641 */
2642 static void
2643 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
2644 {
2645 struct sk_buff *p;
2646 struct sk_buff_head *list = &ppp->mrq;
2647 u32 seq = PPP_MP_CB(skb)->sequence;
2648
2649 /* N.B. we don't need to lock the list lock because we have the
2650 ppp unit receive-side lock. */
2651 skb_queue_walk(list, p) {
2652 if (seq_before(seq, PPP_MP_CB(p)->sequence))
2653 break;
2654 }
2655 __skb_queue_before(list, p, skb);
2656 }
2657
2658 /*
2659 * Reconstruct a packet from the MP fragment queue.
2660 * We go through increasing sequence numbers until we find a
2661 * complete packet, or we get to the sequence number for a fragment
2662 * which hasn't arrived but might still do so.
2663 */
2664 static struct sk_buff *
2665 ppp_mp_reconstruct(struct ppp *ppp)
2666 {
2667 u32 seq = ppp->nextseq;
2668 u32 minseq = ppp->minseq;
2669 struct sk_buff_head *list = &ppp->mrq;
2670 struct sk_buff *p, *tmp;
2671 struct sk_buff *head, *tail;
2672 struct sk_buff *skb = NULL;
2673 int lost = 0, len = 0;
2674
2675 if (ppp->mrru == 0) /* do nothing until mrru is set */
2676 return NULL;
2677 head = __skb_peek(list);
2678 tail = NULL;
2679 skb_queue_walk_safe(list, p, tmp) {
2680 again:
2681 if (seq_before(PPP_MP_CB(p)->sequence, seq)) {
2682 /* this can't happen, anyway ignore the skb */
2683 netdev_err(ppp->dev, "ppp_mp_reconstruct bad "
2684 "seq %u < %u\n",
2685 PPP_MP_CB(p)->sequence, seq);
2686 __skb_unlink(p, list);
2687 kfree_skb(p);
2688 continue;
2689 }
2690 if (PPP_MP_CB(p)->sequence != seq) {
2691 u32 oldseq;
2692 /* Fragment `seq' is missing. If it is after
2693 minseq, it might arrive later, so stop here. */
2694 if (seq_after(seq, minseq))
2695 break;
2696 /* Fragment `seq' is lost, keep going. */
2697 lost = 1;
2698 oldseq = seq;
2699 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)?
2700 minseq + 1: PPP_MP_CB(p)->sequence;
2701
2702 if (ppp->debug & 1)
2703 netdev_printk(KERN_DEBUG, ppp->dev,
2704 "lost frag %u..%u\n",
2705 oldseq, seq-1);
2706
2707 goto again;
2708 }
2709
2710 /*
2711 * At this point we know that all the fragments from
2712 * ppp->nextseq to seq are either present or lost.
2713 * Also, there are no complete packets in the queue
2714 * that have no missing fragments and end before this
2715 * fragment.
2716 */
2717
2718 /* B bit set indicates this fragment starts a packet */
2719 if (PPP_MP_CB(p)->BEbits & B) {
2720 head = p;
2721 lost = 0;
2722 len = 0;
2723 }
2724
2725 len += p->len;
2726
2727 /* Got a complete packet yet? */
2728 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) &&
2729 (PPP_MP_CB(head)->BEbits & B)) {
2730 if (len > ppp->mrru + 2) {
2731 ++ppp->dev->stats.rx_length_errors;
2732 netdev_printk(KERN_DEBUG, ppp->dev,
2733 "PPP: reconstructed packet"
2734 " is too long (%d)\n", len);
2735 } else {
2736 tail = p;
2737 break;
2738 }
2739 ppp->nextseq = seq + 1;
2740 }
2741
2742 /*
2743 * If this is the ending fragment of a packet,
2744 * and we haven't found a complete valid packet yet,
2745 * we can discard up to and including this fragment.
2746 */
2747 if (PPP_MP_CB(p)->BEbits & E) {
2748 struct sk_buff *tmp2;
2749
2750 skb_queue_reverse_walk_from_safe(list, p, tmp2) {
2751 if (ppp->debug & 1)
2752 netdev_printk(KERN_DEBUG, ppp->dev,
2753 "discarding frag %u\n",
2754 PPP_MP_CB(p)->sequence);
2755 __skb_unlink(p, list);
2756 kfree_skb(p);
2757 }
2758 head = skb_peek(list);
2759 if (!head)
2760 break;
2761 }
2762 ++seq;
2763 }
2764
2765 /* If we have a complete packet, copy it all into one skb. */
2766 if (tail != NULL) {
2767 /* If we have discarded any fragments,
2768 signal a receive error. */
2769 if (PPP_MP_CB(head)->sequence != ppp->nextseq) {
2770 skb_queue_walk_safe(list, p, tmp) {
2771 if (p == head)
2772 break;
2773 if (ppp->debug & 1)
2774 netdev_printk(KERN_DEBUG, ppp->dev,
2775 "discarding frag %u\n",
2776 PPP_MP_CB(p)->sequence);
2777 __skb_unlink(p, list);
2778 kfree_skb(p);
2779 }
2780
2781 if (ppp->debug & 1)
2782 netdev_printk(KERN_DEBUG, ppp->dev,
2783 " missed pkts %u..%u\n",
2784 ppp->nextseq,
2785 PPP_MP_CB(head)->sequence-1);
2786 ++ppp->dev->stats.rx_dropped;
2787 ppp_receive_error(ppp);
2788 }
2789
2790 skb = head;
2791 if (head != tail) {
2792 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list;
2793 p = skb_queue_next(list, head);
2794 __skb_unlink(skb, list);
2795 skb_queue_walk_from_safe(list, p, tmp) {
2796 __skb_unlink(p, list);
2797 *fragpp = p;
2798 p->next = NULL;
2799 fragpp = &p->next;
2800
2801 skb->len += p->len;
2802 skb->data_len += p->len;
2803 skb->truesize += p->truesize;
2804
2805 if (p == tail)
2806 break;
2807 }
2808 } else {
2809 __skb_unlink(skb, list);
2810 }
2811
2812 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1;
2813 }
2814
2815 return skb;
2816 }
2817 #endif /* CONFIG_PPP_MULTILINK */
2818
2819 /*
2820 * Channel interface.
2821 */
2822
2823 /* Create a new, unattached ppp channel. */
2824 int ppp_register_channel(struct ppp_channel *chan)
2825 {
2826 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2827 }
2828
2829 /* Create a new, unattached ppp channel for specified net. */
2830 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
2831 {
2832 struct channel *pch;
2833 struct ppp_net *pn;
2834
2835 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2836 if (!pch)
2837 return -ENOMEM;
2838
2839 pn = ppp_pernet(net);
2840
2841 pch->ppp = NULL;
2842 pch->chan = chan;
2843 pch->chan_net = get_net(net);
2844 chan->ppp = pch;
2845 init_ppp_file(&pch->file, CHANNEL);
2846 pch->file.hdrlen = chan->hdrlen;
2847 #ifdef CONFIG_PPP_MULTILINK
2848 pch->lastseq = -1;
2849 #endif /* CONFIG_PPP_MULTILINK */
2850 init_rwsem(&pch->chan_sem);
2851 spin_lock_init(&pch->downl);
2852 rwlock_init(&pch->upl);
2853
2854 spin_lock_bh(&pn->all_channels_lock);
2855 pch->file.index = ++pn->last_channel_index;
2856 list_add(&pch->list, &pn->new_channels);
2857 atomic_inc(&channel_count);
2858 spin_unlock_bh(&pn->all_channels_lock);
2859
2860 return 0;
2861 }
2862
2863 /*
2864 * Return the index of a channel.
2865 */
2866 int ppp_channel_index(struct ppp_channel *chan)
2867 {
2868 struct channel *pch = chan->ppp;
2869
2870 if (pch)
2871 return pch->file.index;
2872 return -1;
2873 }
2874
2875 /*
2876 * Return the PPP unit number to which a channel is connected.
2877 */
2878 int ppp_unit_number(struct ppp_channel *chan)
2879 {
2880 struct channel *pch = chan->ppp;
2881 int unit = -1;
2882
2883 if (pch) {
2884 read_lock_bh(&pch->upl);
2885 if (pch->ppp)
2886 unit = pch->ppp->file.index;
2887 read_unlock_bh(&pch->upl);
2888 }
2889 return unit;
2890 }
2891
2892 /*
2893 * Return the PPP device interface name of a channel.
2894 */
2895 char *ppp_dev_name(struct ppp_channel *chan)
2896 {
2897 struct channel *pch = chan->ppp;
2898 char *name = NULL;
2899
2900 if (pch) {
2901 read_lock_bh(&pch->upl);
2902 if (pch->ppp && pch->ppp->dev)
2903 name = pch->ppp->dev->name;
2904 read_unlock_bh(&pch->upl);
2905 }
2906 return name;
2907 }
2908
2909
2910 /*
2911 * Disconnect a channel from the generic layer.
2912 * This must be called in process context.
2913 */
2914 void
2915 ppp_unregister_channel(struct ppp_channel *chan)
2916 {
2917 struct channel *pch = chan->ppp;
2918 struct ppp_net *pn;
2919
2920 if (!pch)
2921 return; /* should never happen */
2922
2923 chan->ppp = NULL;
2924
2925 /*
2926 * This ensures that we have returned from any calls into the
2927 * the channel's start_xmit or ioctl routine before we proceed.
2928 */
2929 down_write(&pch->chan_sem);
2930 spin_lock_bh(&pch->downl);
2931 pch->chan = NULL;
2932 spin_unlock_bh(&pch->downl);
2933 up_write(&pch->chan_sem);
2934 ppp_disconnect_channel(pch);
2935
2936 pn = ppp_pernet(pch->chan_net);
2937 spin_lock_bh(&pn->all_channels_lock);
2938 list_del(&pch->list);
2939 spin_unlock_bh(&pn->all_channels_lock);
2940
2941 ppp_unbridge_channels(pch);
2942
2943 pch->file.dead = 1;
2944 wake_up_interruptible(&pch->file.rwait);
2945
2946 if (refcount_dec_and_test(&pch->file.refcnt))
2947 ppp_destroy_channel(pch);
2948 }
2949
2950 /*
2951 * Callback from a channel when it can accept more to transmit.
2952 * This should be called at BH/softirq level, not interrupt level.
2953 */
2954 void
2955 ppp_output_wakeup(struct ppp_channel *chan)
2956 {
2957 struct channel *pch = chan->ppp;
2958
2959 if (!pch)
2960 return;
2961 ppp_channel_push(pch);
2962 }
2963
2964 /*
2965 * Compression control.
2966 */
2967
2968 /* Process the PPPIOCSCOMPRESS ioctl. */
2969 static int
2970 ppp_set_compress(struct ppp *ppp, struct ppp_option_data *data)
2971 {
2972 int err = -EFAULT;
2973 struct compressor *cp, *ocomp;
2974 void *state, *ostate;
2975 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2976
2977 if (data->length > CCP_MAX_OPTION_LENGTH)
2978 goto out;
2979 if (copy_from_user(ccp_option, data->ptr, data->length))
2980 goto out;
2981
2982 err = -EINVAL;
2983 if (data->length < 2 || ccp_option[1] < 2 || ccp_option[1] > data->length)
2984 goto out;
2985
2986 cp = try_then_request_module(
2987 find_compressor(ccp_option[0]),
2988 "ppp-compress-%d", ccp_option[0]);
2989 if (!cp)
2990 goto out;
2991
2992 err = -ENOBUFS;
2993 if (data->transmit) {
2994 state = cp->comp_alloc(ccp_option, data->length);
2995 if (state) {
2996 ppp_xmit_lock(ppp);
2997 ppp->xstate &= ~SC_COMP_RUN;
2998 ocomp = ppp->xcomp;
2999 ostate = ppp->xc_state;
3000 ppp->xcomp = cp;
3001 ppp->xc_state = state;
3002 ppp_xmit_unlock(ppp);
3003 if (ostate) {
3004 ocomp->comp_free(ostate);
3005 module_put(ocomp->owner);
3006 }
3007 err = 0;
3008 } else
3009 module_put(cp->owner);
3010
3011 } else {
3012 state = cp->decomp_alloc(ccp_option, data->length);
3013 if (state) {
3014 ppp_recv_lock(ppp);
3015 ppp->rstate &= ~SC_DECOMP_RUN;
3016 ocomp = ppp->rcomp;
3017 ostate = ppp->rc_state;
3018 ppp->rcomp = cp;
3019 ppp->rc_state = state;
3020 ppp_recv_unlock(ppp);
3021 if (ostate) {
3022 ocomp->decomp_free(ostate);
3023 module_put(ocomp->owner);
3024 }
3025 err = 0;
3026 } else
3027 module_put(cp->owner);
3028 }
3029
3030 out:
3031 return err;
3032 }
3033
3034 /*
3035 * Look at a CCP packet and update our state accordingly.
3036 * We assume the caller has the xmit or recv path locked.
3037 */
3038 static void
3039 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
3040 {
3041 unsigned char *dp;
3042 int len;
3043
3044 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
3045 return; /* no header */
3046 dp = skb->data + 2;
3047
3048 switch (CCP_CODE(dp)) {
3049 case CCP_CONFREQ:
3050
3051 /* A ConfReq starts negotiation of compression
3052 * in one direction of transmission,
3053 * and hence brings it down...but which way?
3054 *
3055 * Remember:
3056 * A ConfReq indicates what the sender would like to receive
3057 */
3058 if(inbound)
3059 /* He is proposing what I should send */
3060 ppp->xstate &= ~SC_COMP_RUN;
3061 else
3062 /* I am proposing to what he should send */
3063 ppp->rstate &= ~SC_DECOMP_RUN;
3064
3065 break;
3066
3067 case CCP_TERMREQ:
3068 case CCP_TERMACK:
3069 /*
3070 * CCP is going down, both directions of transmission
3071 */
3072 ppp->rstate &= ~SC_DECOMP_RUN;
3073 ppp->xstate &= ~SC_COMP_RUN;
3074 break;
3075
3076 case CCP_CONFACK:
3077 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
3078 break;
3079 len = CCP_LENGTH(dp);
3080 if (!pskb_may_pull(skb, len + 2))
3081 return; /* too short */
3082 dp += CCP_HDRLEN;
3083 len -= CCP_HDRLEN;
3084 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
3085 break;
3086 if (inbound) {
3087 /* we will start receiving compressed packets */
3088 if (!ppp->rc_state)
3089 break;
3090 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
3091 ppp->file.index, 0, ppp->mru, ppp->debug)) {
3092 ppp->rstate |= SC_DECOMP_RUN;
3093 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
3094 }
3095 } else {
3096 /* we will soon start sending compressed packets */
3097 if (!ppp->xc_state)
3098 break;
3099 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
3100 ppp->file.index, 0, ppp->debug))
3101 ppp->xstate |= SC_COMP_RUN;
3102 }
3103 break;
3104
3105 case CCP_RESETACK:
3106 /* reset the [de]compressor */
3107 if ((ppp->flags & SC_CCP_UP) == 0)
3108 break;
3109 if (inbound) {
3110 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
3111 ppp->rcomp->decomp_reset(ppp->rc_state);
3112 ppp->rstate &= ~SC_DC_ERROR;
3113 }
3114 } else {
3115 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
3116 ppp->xcomp->comp_reset(ppp->xc_state);
3117 }
3118 break;
3119 }
3120 }
3121
3122 /* Free up compression resources. */
3123 static void
3124 ppp_ccp_closed(struct ppp *ppp)
3125 {
3126 void *xstate, *rstate;
3127 struct compressor *xcomp, *rcomp;
3128
3129 ppp_lock(ppp);
3130 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
3131 ppp->xstate = 0;
3132 xcomp = ppp->xcomp;
3133 xstate = ppp->xc_state;
3134 ppp->xc_state = NULL;
3135 ppp->rstate = 0;
3136 rcomp = ppp->rcomp;
3137 rstate = ppp->rc_state;
3138 ppp->rc_state = NULL;
3139 ppp_unlock(ppp);
3140
3141 if (xstate) {
3142 xcomp->comp_free(xstate);
3143 module_put(xcomp->owner);
3144 }
3145 if (rstate) {
3146 rcomp->decomp_free(rstate);
3147 module_put(rcomp->owner);
3148 }
3149 }
3150
3151 /* List of compressors. */
3152 static LIST_HEAD(compressor_list);
3153 static DEFINE_SPINLOCK(compressor_list_lock);
3154
3155 struct compressor_entry {
3156 struct list_head list;
3157 struct compressor *comp;
3158 };
3159
3160 static struct compressor_entry *
3161 find_comp_entry(int proto)
3162 {
3163 struct compressor_entry *ce;
3164
3165 list_for_each_entry(ce, &compressor_list, list) {
3166 if (ce->comp->compress_proto == proto)
3167 return ce;
3168 }
3169 return NULL;
3170 }
3171
3172 /* Register a compressor */
3173 int
3174 ppp_register_compressor(struct compressor *cp)
3175 {
3176 struct compressor_entry *ce;
3177 int ret;
3178 spin_lock(&compressor_list_lock);
3179 ret = -EEXIST;
3180 if (find_comp_entry(cp->compress_proto))
3181 goto out;
3182 ret = -ENOMEM;
3183 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
3184 if (!ce)
3185 goto out;
3186 ret = 0;
3187 ce->comp = cp;
3188 list_add(&ce->list, &compressor_list);
3189 out:
3190 spin_unlock(&compressor_list_lock);
3191 return ret;
3192 }
3193
3194 /* Unregister a compressor */
3195 void
3196 ppp_unregister_compressor(struct compressor *cp)
3197 {
3198 struct compressor_entry *ce;
3199
3200 spin_lock(&compressor_list_lock);
3201 ce = find_comp_entry(cp->compress_proto);
3202 if (ce && ce->comp == cp) {
3203 list_del(&ce->list);
3204 kfree(ce);
3205 }
3206 spin_unlock(&compressor_list_lock);
3207 }
3208
3209 /* Find a compressor. */
3210 static struct compressor *
3211 find_compressor(int type)
3212 {
3213 struct compressor_entry *ce;
3214 struct compressor *cp = NULL;
3215
3216 spin_lock(&compressor_list_lock);
3217 ce = find_comp_entry(type);
3218 if (ce) {
3219 cp = ce->comp;
3220 if (!try_module_get(cp->owner))
3221 cp = NULL;
3222 }
3223 spin_unlock(&compressor_list_lock);
3224 return cp;
3225 }
3226
3227 /*
3228 * Miscelleneous stuff.
3229 */
3230
3231 static void
3232 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
3233 {
3234 struct slcompress *vj = ppp->vj;
3235
3236 memset(st, 0, sizeof(*st));
3237 st->p.ppp_ipackets = ppp->stats64.rx_packets;
3238 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
3239 st->p.ppp_ibytes = ppp->stats64.rx_bytes;
3240 st->p.ppp_opackets = ppp->stats64.tx_packets;
3241 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
3242 st->p.ppp_obytes = ppp->stats64.tx_bytes;
3243 if (!vj)
3244 return;
3245 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
3246 st->vj.vjs_compressed = vj->sls_o_compressed;
3247 st->vj.vjs_searches = vj->sls_o_searches;
3248 st->vj.vjs_misses = vj->sls_o_misses;
3249 st->vj.vjs_errorin = vj->sls_i_error;
3250 st->vj.vjs_tossed = vj->sls_i_tossed;
3251 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
3252 st->vj.vjs_compressedin = vj->sls_i_compressed;
3253 }
3254
3255 /*
3256 * Stuff for handling the lists of ppp units and channels
3257 * and for initialization.
3258 */
3259
3260 /*
3261 * Create a new ppp interface unit. Fails if it can't allocate memory
3262 * or if there is already a unit with the requested number.
3263 * unit == -1 means allocate a new number.
3264 */
3265 static int ppp_create_interface(struct net *net, struct file *file, int *unit)
3266 {
3267 struct ppp_config conf = {
3268 .file = file,
3269 .unit = *unit,
3270 .ifname_is_set = false,
3271 };
3272 struct net_device *dev;
3273 struct ppp *ppp;
3274 int err;
3275
3276 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_ENUM, ppp_setup);
3277 if (!dev) {
3278 err = -ENOMEM;
3279 goto err;
3280 }
3281 dev_net_set(dev, net);
3282 dev->rtnl_link_ops = &ppp_link_ops;
3283
3284 rtnl_lock();
3285
3286 err = ppp_dev_configure(net, dev, &conf);
3287 if (err < 0)
3288 goto err_dev;
3289 ppp = netdev_priv(dev);
3290 *unit = ppp->file.index;
3291
3292 rtnl_unlock();
3293
3294 return 0;
3295
3296 err_dev:
3297 rtnl_unlock();
3298 free_netdev(dev);
3299 err:
3300 return err;
3301 }
3302
3303 /*
3304 * Initialize a ppp_file structure.
3305 */
3306 static void
3307 init_ppp_file(struct ppp_file *pf, int kind)
3308 {
3309 pf->kind = kind;
3310 skb_queue_head_init(&pf->xq);
3311 skb_queue_head_init(&pf->rq);
3312 refcount_set(&pf->refcnt, 1);
3313 init_waitqueue_head(&pf->rwait);
3314 }
3315
3316 /*
3317 * Free the memory used by a ppp unit. This is only called once
3318 * there are no channels connected to the unit and no file structs
3319 * that reference the unit.
3320 */
3321 static void ppp_destroy_interface(struct ppp *ppp)
3322 {
3323 atomic_dec(&ppp_unit_count);
3324
3325 if (!ppp->file.dead || ppp->n_channels) {
3326 /* "can't happen" */
3327 netdev_err(ppp->dev, "ppp: destroying ppp struct %p "
3328 "but dead=%d n_channels=%d !\n",
3329 ppp, ppp->file.dead, ppp->n_channels);
3330 return;
3331 }
3332
3333 ppp_ccp_closed(ppp);
3334 if (ppp->vj) {
3335 slhc_free(ppp->vj);
3336 ppp->vj = NULL;
3337 }
3338 skb_queue_purge(&ppp->file.xq);
3339 skb_queue_purge(&ppp->file.rq);
3340 #ifdef CONFIG_PPP_MULTILINK
3341 skb_queue_purge(&ppp->mrq);
3342 #endif /* CONFIG_PPP_MULTILINK */
3343 #ifdef CONFIG_PPP_FILTER
3344 if (ppp->pass_filter) {
3345 bpf_prog_destroy(ppp->pass_filter);
3346 ppp->pass_filter = NULL;
3347 }
3348
3349 if (ppp->active_filter) {
3350 bpf_prog_destroy(ppp->active_filter);
3351 ppp->active_filter = NULL;
3352 }
3353 #endif /* CONFIG_PPP_FILTER */
3354
3355 kfree_skb(ppp->xmit_pending);
3356 free_percpu(ppp->xmit_recursion);
3357
3358 free_netdev(ppp->dev);
3359 }
3360
3361 /*
3362 * Locate an existing ppp unit.
3363 * The caller should have locked the all_ppp_mutex.
3364 */
3365 static struct ppp *
3366 ppp_find_unit(struct ppp_net *pn, int unit)
3367 {
3368 return unit_find(&pn->units_idr, unit);
3369 }
3370
3371 /*
3372 * Locate an existing ppp channel.
3373 * The caller should have locked the all_channels_lock.
3374 * First we look in the new_channels list, then in the
3375 * all_channels list. If found in the new_channels list,
3376 * we move it to the all_channels list. This is for speed
3377 * when we have a lot of channels in use.
3378 */
3379 static struct channel *
3380 ppp_find_channel(struct ppp_net *pn, int unit)
3381 {
3382 struct channel *pch;
3383
3384 list_for_each_entry(pch, &pn->new_channels, list) {
3385 if (pch->file.index == unit) {
3386 list_move(&pch->list, &pn->all_channels);
3387 return pch;
3388 }
3389 }
3390
3391 list_for_each_entry(pch, &pn->all_channels, list) {
3392 if (pch->file.index == unit)
3393 return pch;
3394 }
3395
3396 return NULL;
3397 }
3398
3399 /*
3400 * Connect a PPP channel to a PPP interface unit.
3401 */
3402 static int
3403 ppp_connect_channel(struct channel *pch, int unit)
3404 {
3405 struct ppp *ppp;
3406 struct ppp_net *pn;
3407 int ret = -ENXIO;
3408 int hdrlen;
3409
3410 pn = ppp_pernet(pch->chan_net);
3411
3412 mutex_lock(&pn->all_ppp_mutex);
3413 ppp = ppp_find_unit(pn, unit);
3414 if (!ppp)
3415 goto out;
3416 write_lock_bh(&pch->upl);
3417 ret = -EINVAL;
3418 if (pch->ppp ||
3419 rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl)))
3420 goto outl;
3421
3422 ppp_lock(ppp);
3423 spin_lock_bh(&pch->downl);
3424 if (!pch->chan) {
3425 /* Don't connect unregistered channels */
3426 spin_unlock_bh(&pch->downl);
3427 ppp_unlock(ppp);
3428 ret = -ENOTCONN;
3429 goto outl;
3430 }
3431 spin_unlock_bh(&pch->downl);
3432 if (pch->file.hdrlen > ppp->file.hdrlen)
3433 ppp->file.hdrlen = pch->file.hdrlen;
3434 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
3435 if (hdrlen > ppp->dev->hard_header_len)
3436 ppp->dev->hard_header_len = hdrlen;
3437 list_add_tail(&pch->clist, &ppp->channels);
3438 ++ppp->n_channels;
3439 pch->ppp = ppp;
3440 refcount_inc(&ppp->file.refcnt);
3441 ppp_unlock(ppp);
3442 ret = 0;
3443
3444 outl:
3445 write_unlock_bh(&pch->upl);
3446 out:
3447 mutex_unlock(&pn->all_ppp_mutex);
3448 return ret;
3449 }
3450
3451 /*
3452 * Disconnect a channel from its ppp unit.
3453 */
3454 static int
3455 ppp_disconnect_channel(struct channel *pch)
3456 {
3457 struct ppp *ppp;
3458 int err = -EINVAL;
3459
3460 write_lock_bh(&pch->upl);
3461 ppp = pch->ppp;
3462 pch->ppp = NULL;
3463 write_unlock_bh(&pch->upl);
3464 if (ppp) {
3465 /* remove it from the ppp unit's list */
3466 ppp_lock(ppp);
3467 list_del(&pch->clist);
3468 if (--ppp->n_channels == 0)
3469 wake_up_interruptible(&ppp->file.rwait);
3470 ppp_unlock(ppp);
3471 if (refcount_dec_and_test(&ppp->file.refcnt))
3472 ppp_destroy_interface(ppp);
3473 err = 0;
3474 }
3475 return err;
3476 }
3477
3478 /*
3479 * Free up the resources used by a ppp channel.
3480 */
3481 static void ppp_destroy_channel(struct channel *pch)
3482 {
3483 put_net(pch->chan_net);
3484 pch->chan_net = NULL;
3485
3486 atomic_dec(&channel_count);
3487
3488 if (!pch->file.dead) {
3489 /* "can't happen" */
3490 pr_err("ppp: destroying undead channel %p !\n", pch);
3491 return;
3492 }
3493 skb_queue_purge(&pch->file.xq);
3494 skb_queue_purge(&pch->file.rq);
3495 kfree(pch);
3496 }
3497
3498 static void __exit ppp_cleanup(void)
3499 {
3500 /* should never happen */
3501 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
3502 pr_err("PPP: removing module but units remain!\n");
3503 rtnl_link_unregister(&ppp_link_ops);
3504 unregister_chrdev(PPP_MAJOR, "ppp");
3505 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
3506 class_destroy(ppp_class);
3507 unregister_pernet_device(&ppp_net_ops);
3508 }
3509
3510 /*
3511 * Units handling. Caller must protect concurrent access
3512 * by holding all_ppp_mutex
3513 */
3514
3515 /* associate pointer with specified number */
3516 static int unit_set(struct idr *p, void *ptr, int n)
3517 {
3518 int unit;
3519
3520 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL);
3521 if (unit == -ENOSPC)
3522 unit = -EINVAL;
3523 return unit;
3524 }
3525
3526 /* get new free unit number and associate pointer with it */
3527 static int unit_get(struct idr *p, void *ptr)
3528 {
3529 return idr_alloc(p, ptr, 0, 0, GFP_KERNEL);
3530 }
3531
3532 /* put unit number back to a pool */
3533 static void unit_put(struct idr *p, int n)
3534 {
3535 idr_remove(p, n);
3536 }
3537
3538 /* get pointer associated with the number */
3539 static void *unit_find(struct idr *p, int n)
3540 {
3541 return idr_find(p, n);
3542 }
3543
3544 /* Module/initialization stuff */
3545
3546 module_init(ppp_init);
3547 module_exit(ppp_cleanup);
3548
3549 EXPORT_SYMBOL(ppp_register_net_channel);
3550 EXPORT_SYMBOL(ppp_register_channel);
3551 EXPORT_SYMBOL(ppp_unregister_channel);
3552 EXPORT_SYMBOL(ppp_channel_index);
3553 EXPORT_SYMBOL(ppp_unit_number);
3554 EXPORT_SYMBOL(ppp_dev_name);
3555 EXPORT_SYMBOL(ppp_input);
3556 EXPORT_SYMBOL(ppp_input_error);
3557 EXPORT_SYMBOL(ppp_output_wakeup);
3558 EXPORT_SYMBOL(ppp_register_compressor);
3559 EXPORT_SYMBOL(ppp_unregister_compressor);
3560 MODULE_LICENSE("GPL");
3561 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
3562 MODULE_ALIAS_RTNL_LINK("ppp");
3563 MODULE_ALIAS("devname:ppp");
Linux with added FPC-III support