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 #define PPP_PROTO_LEN 2
73
74 /*
75 * An instance of /dev/ppp can be associated with either a ppp
76 * interface unit or a ppp channel. In both cases, file->private_data
77 * points to one of these.
78 */
79 struct ppp_file {
80 enum {
81 INTERFACE=1, CHANNEL
82 } kind;
83 struct sk_buff_head xq; /* pppd transmit queue */
84 struct sk_buff_head rq; /* receive queue for pppd */
85 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */
86 refcount_t refcnt; /* # refs (incl /dev/ppp attached) */
87 int hdrlen; /* space to leave for headers */
88 int index; /* interface unit / channel number */
89 int dead; /* unit/channel has been shut down */
90 };
91
92 #define PF_TO_X(pf, X) container_of(pf, X, file)
93
94 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
95 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
96
97 /*
98 * Data structure to hold primary network stats for which
99 * we want to use 64 bit storage. Other network stats
100 * are stored in dev->stats of the ppp strucute.
101 */
102 struct ppp_link_stats {
103 u64 rx_packets;
104 u64 tx_packets;
105 u64 rx_bytes;
106 u64 tx_bytes;
107 };
108
109 /*
110 * Data structure describing one ppp unit.
111 * A ppp unit corresponds to a ppp network interface device
112 * and represents a multilink bundle.
113 * It can have 0 or more ppp channels connected to it.
114 */
115 struct ppp {
116 struct ppp_file file; /* stuff for read/write/poll 0 */
117 struct file *owner; /* file that owns this unit 48 */
118 struct list_head channels; /* list of attached channels 4c */
119 int n_channels; /* how many channels are attached 54 */
120 spinlock_t rlock; /* lock for receive side 58 */
121 spinlock_t wlock; /* lock for transmit side 5c */
122 int __percpu *xmit_recursion; /* xmit recursion detect */
123 int mru; /* max receive unit 60 */
124 unsigned int flags; /* control bits 64 */
125 unsigned int xstate; /* transmit state bits 68 */
126 unsigned int rstate; /* receive state bits 6c */
127 int debug; /* debug flags 70 */
128 struct slcompress *vj; /* state for VJ header compression */
129 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
130 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
131 struct compressor *xcomp; /* transmit packet compressor 8c */
132 void *xc_state; /* its internal state 90 */
133 struct compressor *rcomp; /* receive decompressor 94 */
134 void *rc_state; /* its internal state 98 */
135 unsigned long last_xmit; /* jiffies when last pkt sent 9c */
136 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
137 struct net_device *dev; /* network interface device a4 */
138 int closing; /* is device closing down? a8 */
139 #ifdef CONFIG_PPP_MULTILINK
140 int nxchan; /* next channel to send something on */
141 u32 nxseq; /* next sequence number to send */
142 int mrru; /* MP: max reconst. receive unit */
143 u32 nextseq; /* MP: seq no of next packet */
144 u32 minseq; /* MP: min of most recent seqnos */
145 struct sk_buff_head mrq; /* MP: receive reconstruction queue */
146 #endif /* CONFIG_PPP_MULTILINK */
147 #ifdef CONFIG_PPP_FILTER
148 struct bpf_prog *pass_filter; /* filter for packets to pass */
149 struct bpf_prog *active_filter; /* filter for pkts to reset idle */
150 #endif /* CONFIG_PPP_FILTER */
151 struct net *ppp_net; /* the net we belong to */
152 struct ppp_link_stats stats64; /* 64 bit network stats */
153 };
154
155 /*
156 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
157 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
158 * SC_MUST_COMP
159 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
160 * Bits in xstate: SC_COMP_RUN
161 */
162 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
163 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
164 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
165
166 /*
167 * Private data structure for each channel.
168 * This includes the data structure used for multilink.
169 */
170 struct channel {
171 struct ppp_file file; /* stuff for read/write/poll */
172 struct list_head list; /* link in all/new_channels list */
173 struct ppp_channel *chan; /* public channel data structure */
174 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
175 spinlock_t downl; /* protects `chan', file.xq dequeue */
176 struct ppp *ppp; /* ppp unit we're connected to */
177 struct net *chan_net; /* the net channel belongs to */
178 struct list_head clist; /* link in list of channels per unit */
179 rwlock_t upl; /* protects `ppp' */
180 #ifdef CONFIG_PPP_MULTILINK
181 u8 avail; /* flag used in multilink stuff */
182 u8 had_frag; /* >= 1 fragments have been sent */
183 u32 lastseq; /* MP: last sequence # received */
184 int speed; /* speed of the corresponding ppp channel*/
185 #endif /* CONFIG_PPP_MULTILINK */
186 };
187
188 struct ppp_config {
189 struct file *file;
190 s32 unit;
191 bool ifname_is_set;
192 };
193
194 /*
195 * SMP locking issues:
196 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
197 * list and the ppp.n_channels field, you need to take both locks
198 * before you modify them.
199 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
200 * channel.downl.
201 */
202
203 static DEFINE_MUTEX(ppp_mutex);
204 static atomic_t ppp_unit_count = ATOMIC_INIT(0);
205 static atomic_t channel_count = ATOMIC_INIT(0);
206
207 /* per-net private data for this module */
208 static unsigned int ppp_net_id __read_mostly;
209 struct ppp_net {
210 /* units to ppp mapping */
211 struct idr units_idr;
212
213 /*
214 * all_ppp_mutex protects the units_idr mapping.
215 * It also ensures that finding a ppp unit in the units_idr
216 * map and updating its file.refcnt field is atomic.
217 */
218 struct mutex all_ppp_mutex;
219
220 /* channels */
221 struct list_head all_channels;
222 struct list_head new_channels;
223 int last_channel_index;
224
225 /*
226 * all_channels_lock protects all_channels and
227 * last_channel_index, and the atomicity of find
228 * a channel and updating its file.refcnt field.
229 */
230 spinlock_t all_channels_lock;
231 };
232
233 /* Get the PPP protocol number from a skb */
234 #define PPP_PROTO(skb) get_unaligned_be16((skb)->data)
235
236 /* We limit the length of ppp->file.rq to this (arbitrary) value */
237 #define PPP_MAX_RQLEN 32
238
239 /*
240 * Maximum number of multilink fragments queued up.
241 * This has to be large enough to cope with the maximum latency of
242 * the slowest channel relative to the others. Strictly it should
243 * depend on the number of channels and their characteristics.
244 */
245 #define PPP_MP_MAX_QLEN 128
246
247 /* Multilink header bits. */
248 #define B 0x80 /* this fragment begins a packet */
249 #define E 0x40 /* this fragment ends a packet */
250
251 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */
252 #define seq_before(a, b) ((s32)((a) - (b)) < 0)
253 #define seq_after(a, b) ((s32)((a) - (b)) > 0)
254
255 /* Prototypes. */
256 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
257 struct file *file, unsigned int cmd, unsigned long arg);
258 static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb);
259 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
260 static void ppp_push(struct ppp *ppp);
261 static void ppp_channel_push(struct channel *pch);
262 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
263 struct channel *pch);
264 static void ppp_receive_error(struct ppp *ppp);
265 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
266 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
267 struct sk_buff *skb);
268 #ifdef CONFIG_PPP_MULTILINK
269 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
270 struct channel *pch);
271 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
272 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
273 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
274 #endif /* CONFIG_PPP_MULTILINK */
275 static int ppp_set_compress(struct ppp *ppp, struct ppp_option_data *data);
276 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
277 static void ppp_ccp_closed(struct ppp *ppp);
278 static struct compressor *find_compressor(int type);
279 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
280 static int ppp_create_interface(struct net *net, struct file *file, int *unit);
281 static void init_ppp_file(struct ppp_file *pf, int kind);
282 static void ppp_destroy_interface(struct ppp *ppp);
283 static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit);
284 static struct channel *ppp_find_channel(struct ppp_net *pn, int unit);
285 static int ppp_connect_channel(struct channel *pch, int unit);
286 static int ppp_disconnect_channel(struct channel *pch);
287 static void ppp_destroy_channel(struct channel *pch);
288 static int unit_get(struct idr *p, void *ptr, int min);
289 static int unit_set(struct idr *p, void *ptr, int n);
290 static void unit_put(struct idr *p, int n);
291 static void *unit_find(struct idr *p, int n);
292 static void ppp_setup(struct net_device *dev);
293
294 static const struct net_device_ops ppp_netdev_ops;
295
296 static struct class *ppp_class;
297
298 /* per net-namespace data */
ppp_pernet(struct net * net)299 static inline struct ppp_net *ppp_pernet(struct net *net)
300 {
301 return net_generic(net, ppp_net_id);
302 }
303
304 /* Translates a PPP protocol number to a NP index (NP == network protocol) */
proto_to_npindex(int proto)305 static inline int proto_to_npindex(int proto)
306 {
307 switch (proto) {
308 case PPP_IP:
309 return NP_IP;
310 case PPP_IPV6:
311 return NP_IPV6;
312 case PPP_IPX:
313 return NP_IPX;
314 case PPP_AT:
315 return NP_AT;
316 case PPP_MPLS_UC:
317 return NP_MPLS_UC;
318 case PPP_MPLS_MC:
319 return NP_MPLS_MC;
320 }
321 return -EINVAL;
322 }
323
324 /* Translates an NP index into a PPP protocol number */
325 static const int npindex_to_proto[NUM_NP] = {
326 PPP_IP,
327 PPP_IPV6,
328 PPP_IPX,
329 PPP_AT,
330 PPP_MPLS_UC,
331 PPP_MPLS_MC,
332 };
333
334 /* Translates an ethertype into an NP index */
ethertype_to_npindex(int ethertype)335 static inline int ethertype_to_npindex(int ethertype)
336 {
337 switch (ethertype) {
338 case ETH_P_IP:
339 return NP_IP;
340 case ETH_P_IPV6:
341 return NP_IPV6;
342 case ETH_P_IPX:
343 return NP_IPX;
344 case ETH_P_PPPTALK:
345 case ETH_P_ATALK:
346 return NP_AT;
347 case ETH_P_MPLS_UC:
348 return NP_MPLS_UC;
349 case ETH_P_MPLS_MC:
350 return NP_MPLS_MC;
351 }
352 return -1;
353 }
354
355 /* Translates an NP index into an ethertype */
356 static const int npindex_to_ethertype[NUM_NP] = {
357 ETH_P_IP,
358 ETH_P_IPV6,
359 ETH_P_IPX,
360 ETH_P_PPPTALK,
361 ETH_P_MPLS_UC,
362 ETH_P_MPLS_MC,
363 };
364
365 /*
366 * Locking shorthand.
367 */
368 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
369 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
370 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
371 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
372 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
373 ppp_recv_lock(ppp); } while (0)
374 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
375 ppp_xmit_unlock(ppp); } while (0)
376
377 /*
378 * /dev/ppp device routines.
379 * The /dev/ppp device is used by pppd to control the ppp unit.
380 * It supports the read, write, ioctl and poll functions.
381 * Open instances of /dev/ppp can be in one of three states:
382 * unattached, attached to a ppp unit, or attached to a ppp channel.
383 */
ppp_open(struct inode * inode,struct file * file)384 static int ppp_open(struct inode *inode, struct file *file)
385 {
386 /*
387 * This could (should?) be enforced by the permissions on /dev/ppp.
388 */
389 if (!ns_capable(file->f_cred->user_ns, CAP_NET_ADMIN))
390 return -EPERM;
391 return 0;
392 }
393
ppp_release(struct inode * unused,struct file * file)394 static int ppp_release(struct inode *unused, struct file *file)
395 {
396 struct ppp_file *pf = file->private_data;
397 struct ppp *ppp;
398
399 if (pf) {
400 file->private_data = NULL;
401 if (pf->kind == INTERFACE) {
402 ppp = PF_TO_PPP(pf);
403 rtnl_lock();
404 if (file == ppp->owner)
405 unregister_netdevice(ppp->dev);
406 rtnl_unlock();
407 }
408 if (refcount_dec_and_test(&pf->refcnt)) {
409 switch (pf->kind) {
410 case INTERFACE:
411 ppp_destroy_interface(PF_TO_PPP(pf));
412 break;
413 case CHANNEL:
414 ppp_destroy_channel(PF_TO_CHANNEL(pf));
415 break;
416 }
417 }
418 }
419 return 0;
420 }
421
ppp_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)422 static ssize_t ppp_read(struct file *file, char __user *buf,
423 size_t count, loff_t *ppos)
424 {
425 struct ppp_file *pf = file->private_data;
426 DECLARE_WAITQUEUE(wait, current);
427 ssize_t ret;
428 struct sk_buff *skb = NULL;
429 struct iovec iov;
430 struct iov_iter to;
431
432 ret = count;
433
434 if (!pf)
435 return -ENXIO;
436 add_wait_queue(&pf->rwait, &wait);
437 for (;;) {
438 set_current_state(TASK_INTERRUPTIBLE);
439 skb = skb_dequeue(&pf->rq);
440 if (skb)
441 break;
442 ret = 0;
443 if (pf->dead)
444 break;
445 if (pf->kind == INTERFACE) {
446 /*
447 * Return 0 (EOF) on an interface that has no
448 * channels connected, unless it is looping
449 * network traffic (demand mode).
450 */
451 struct ppp *ppp = PF_TO_PPP(pf);
452
453 ppp_recv_lock(ppp);
454 if (ppp->n_channels == 0 &&
455 (ppp->flags & SC_LOOP_TRAFFIC) == 0) {
456 ppp_recv_unlock(ppp);
457 break;
458 }
459 ppp_recv_unlock(ppp);
460 }
461 ret = -EAGAIN;
462 if (file->f_flags & O_NONBLOCK)
463 break;
464 ret = -ERESTARTSYS;
465 if (signal_pending(current))
466 break;
467 schedule();
468 }
469 set_current_state(TASK_RUNNING);
470 remove_wait_queue(&pf->rwait, &wait);
471
472 if (!skb)
473 goto out;
474
475 ret = -EOVERFLOW;
476 if (skb->len > count)
477 goto outf;
478 ret = -EFAULT;
479 iov.iov_base = buf;
480 iov.iov_len = count;
481 iov_iter_init(&to, READ, &iov, 1, count);
482 if (skb_copy_datagram_iter(skb, 0, &to, skb->len))
483 goto outf;
484 ret = skb->len;
485
486 outf:
487 kfree_skb(skb);
488 out:
489 return ret;
490 }
491
ppp_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)492 static ssize_t ppp_write(struct file *file, const char __user *buf,
493 size_t count, loff_t *ppos)
494 {
495 struct ppp_file *pf = file->private_data;
496 struct sk_buff *skb;
497 ssize_t ret;
498
499 if (!pf)
500 return -ENXIO;
501 /* All PPP packets should start with the 2-byte protocol */
502 if (count < PPP_PROTO_LEN)
503 return -EINVAL;
504 ret = -ENOMEM;
505 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
506 if (!skb)
507 goto out;
508 skb_reserve(skb, pf->hdrlen);
509 ret = -EFAULT;
510 if (copy_from_user(skb_put(skb, count), buf, count)) {
511 kfree_skb(skb);
512 goto out;
513 }
514
515 switch (pf->kind) {
516 case INTERFACE:
517 ppp_xmit_process(PF_TO_PPP(pf), skb);
518 break;
519 case CHANNEL:
520 skb_queue_tail(&pf->xq, skb);
521 ppp_channel_push(PF_TO_CHANNEL(pf));
522 break;
523 }
524
525 ret = count;
526
527 out:
528 return ret;
529 }
530
531 /* No kernel lock - fine */
ppp_poll(struct file * file,poll_table * wait)532 static __poll_t ppp_poll(struct file *file, poll_table *wait)
533 {
534 struct ppp_file *pf = file->private_data;
535 __poll_t mask;
536
537 if (!pf)
538 return 0;
539 poll_wait(file, &pf->rwait, wait);
540 mask = EPOLLOUT | EPOLLWRNORM;
541 if (skb_peek(&pf->rq))
542 mask |= EPOLLIN | EPOLLRDNORM;
543 if (pf->dead)
544 mask |= EPOLLHUP;
545 else if (pf->kind == INTERFACE) {
546 /* see comment in ppp_read */
547 struct ppp *ppp = PF_TO_PPP(pf);
548
549 ppp_recv_lock(ppp);
550 if (ppp->n_channels == 0 &&
551 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
552 mask |= EPOLLIN | EPOLLRDNORM;
553 ppp_recv_unlock(ppp);
554 }
555
556 return mask;
557 }
558
559 #ifdef CONFIG_PPP_FILTER
get_filter(struct sock_fprog * uprog)560 static struct bpf_prog *get_filter(struct sock_fprog *uprog)
561 {
562 struct sock_fprog_kern fprog;
563 struct bpf_prog *res = NULL;
564 int err;
565
566 if (!uprog->len)
567 return NULL;
568
569 /* uprog->len is unsigned short, so no overflow here */
570 fprog.len = uprog->len;
571 fprog.filter = memdup_user(uprog->filter,
572 uprog->len * sizeof(struct sock_filter));
573 if (IS_ERR(fprog.filter))
574 return ERR_CAST(fprog.filter);
575
576 err = bpf_prog_create(&res, &fprog);
577 kfree(fprog.filter);
578
579 return err ? ERR_PTR(err) : res;
580 }
581
ppp_get_filter(struct sock_fprog __user * p)582 static struct bpf_prog *ppp_get_filter(struct sock_fprog __user *p)
583 {
584 struct sock_fprog uprog;
585
586 if (copy_from_user(&uprog, p, sizeof(struct sock_fprog)))
587 return ERR_PTR(-EFAULT);
588 return get_filter(&uprog);
589 }
590
591 #ifdef CONFIG_COMPAT
592 struct sock_fprog32 {
593 unsigned short len;
594 compat_caddr_t filter;
595 };
596
597 #define PPPIOCSPASS32 _IOW('t', 71, struct sock_fprog32)
598 #define PPPIOCSACTIVE32 _IOW('t', 70, struct sock_fprog32)
599
compat_ppp_get_filter(struct sock_fprog32 __user * p)600 static struct bpf_prog *compat_ppp_get_filter(struct sock_fprog32 __user *p)
601 {
602 struct sock_fprog32 uprog32;
603 struct sock_fprog uprog;
604
605 if (copy_from_user(&uprog32, p, sizeof(struct sock_fprog32)))
606 return ERR_PTR(-EFAULT);
607 uprog.len = uprog32.len;
608 uprog.filter = compat_ptr(uprog32.filter);
609 return get_filter(&uprog);
610 }
611 #endif
612 #endif
613
ppp_ioctl(struct file * file,unsigned int cmd,unsigned long arg)614 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
615 {
616 struct ppp_file *pf;
617 struct ppp *ppp;
618 int err = -EFAULT, val, val2, i;
619 struct ppp_idle32 idle32;
620 struct ppp_idle64 idle64;
621 struct npioctl npi;
622 int unit, cflags;
623 struct slcompress *vj;
624 void __user *argp = (void __user *)arg;
625 int __user *p = argp;
626
627 mutex_lock(&ppp_mutex);
628
629 pf = file->private_data;
630 if (!pf) {
631 err = ppp_unattached_ioctl(current->nsproxy->net_ns,
632 pf, file, cmd, arg);
633 goto out;
634 }
635
636 if (cmd == PPPIOCDETACH) {
637 /*
638 * PPPIOCDETACH is no longer supported as it was heavily broken,
639 * and is only known to have been used by pppd older than
640 * ppp-2.4.2 (released November 2003).
641 */
642 pr_warn_once("%s (%d) used obsolete PPPIOCDETACH ioctl\n",
643 current->comm, current->pid);
644 err = -EINVAL;
645 goto out;
646 }
647
648 if (pf->kind == CHANNEL) {
649 struct channel *pch;
650 struct ppp_channel *chan;
651
652 pch = PF_TO_CHANNEL(pf);
653
654 switch (cmd) {
655 case PPPIOCCONNECT:
656 if (get_user(unit, p))
657 break;
658 err = ppp_connect_channel(pch, unit);
659 break;
660
661 case PPPIOCDISCONN:
662 err = ppp_disconnect_channel(pch);
663 break;
664
665 default:
666 down_read(&pch->chan_sem);
667 chan = pch->chan;
668 err = -ENOTTY;
669 if (chan && chan->ops->ioctl)
670 err = chan->ops->ioctl(chan, cmd, arg);
671 up_read(&pch->chan_sem);
672 }
673 goto out;
674 }
675
676 if (pf->kind != INTERFACE) {
677 /* can't happen */
678 pr_err("PPP: not interface or channel??\n");
679 err = -EINVAL;
680 goto out;
681 }
682
683 ppp = PF_TO_PPP(pf);
684 switch (cmd) {
685 case PPPIOCSMRU:
686 if (get_user(val, p))
687 break;
688 ppp->mru = val;
689 err = 0;
690 break;
691
692 case PPPIOCSFLAGS:
693 if (get_user(val, p))
694 break;
695 ppp_lock(ppp);
696 cflags = ppp->flags & ~val;
697 #ifdef CONFIG_PPP_MULTILINK
698 if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK))
699 ppp->nextseq = 0;
700 #endif
701 ppp->flags = val & SC_FLAG_BITS;
702 ppp_unlock(ppp);
703 if (cflags & SC_CCP_OPEN)
704 ppp_ccp_closed(ppp);
705 err = 0;
706 break;
707
708 case PPPIOCGFLAGS:
709 val = ppp->flags | ppp->xstate | ppp->rstate;
710 if (put_user(val, p))
711 break;
712 err = 0;
713 break;
714
715 case PPPIOCSCOMPRESS:
716 {
717 struct ppp_option_data data;
718 if (copy_from_user(&data, argp, sizeof(data)))
719 err = -EFAULT;
720 else
721 err = ppp_set_compress(ppp, &data);
722 break;
723 }
724 case PPPIOCGUNIT:
725 if (put_user(ppp->file.index, p))
726 break;
727 err = 0;
728 break;
729
730 case PPPIOCSDEBUG:
731 if (get_user(val, p))
732 break;
733 ppp->debug = val;
734 err = 0;
735 break;
736
737 case PPPIOCGDEBUG:
738 if (put_user(ppp->debug, p))
739 break;
740 err = 0;
741 break;
742
743 case PPPIOCGIDLE32:
744 idle32.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
745 idle32.recv_idle = (jiffies - ppp->last_recv) / HZ;
746 if (copy_to_user(argp, &idle32, sizeof(idle32)))
747 break;
748 err = 0;
749 break;
750
751 case PPPIOCGIDLE64:
752 idle64.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
753 idle64.recv_idle = (jiffies - ppp->last_recv) / HZ;
754 if (copy_to_user(argp, &idle64, sizeof(idle64)))
755 break;
756 err = 0;
757 break;
758
759 case PPPIOCSMAXCID:
760 if (get_user(val, p))
761 break;
762 val2 = 15;
763 if ((val >> 16) != 0) {
764 val2 = val >> 16;
765 val &= 0xffff;
766 }
767 vj = slhc_init(val2+1, val+1);
768 if (IS_ERR(vj)) {
769 err = PTR_ERR(vj);
770 break;
771 }
772 ppp_lock(ppp);
773 if (ppp->vj)
774 slhc_free(ppp->vj);
775 ppp->vj = vj;
776 ppp_unlock(ppp);
777 err = 0;
778 break;
779
780 case PPPIOCGNPMODE:
781 case PPPIOCSNPMODE:
782 if (copy_from_user(&npi, argp, sizeof(npi)))
783 break;
784 err = proto_to_npindex(npi.protocol);
785 if (err < 0)
786 break;
787 i = err;
788 if (cmd == PPPIOCGNPMODE) {
789 err = -EFAULT;
790 npi.mode = ppp->npmode[i];
791 if (copy_to_user(argp, &npi, sizeof(npi)))
792 break;
793 } else {
794 ppp->npmode[i] = npi.mode;
795 /* we may be able to transmit more packets now (??) */
796 netif_wake_queue(ppp->dev);
797 }
798 err = 0;
799 break;
800
801 #ifdef CONFIG_PPP_FILTER
802 case PPPIOCSPASS:
803 case PPPIOCSACTIVE:
804 {
805 struct bpf_prog *filter = ppp_get_filter(argp);
806 struct bpf_prog **which;
807
808 if (IS_ERR(filter)) {
809 err = PTR_ERR(filter);
810 break;
811 }
812 if (cmd == PPPIOCSPASS)
813 which = &ppp->pass_filter;
814 else
815 which = &ppp->active_filter;
816 ppp_lock(ppp);
817 if (*which)
818 bpf_prog_destroy(*which);
819 *which = filter;
820 ppp_unlock(ppp);
821 err = 0;
822 break;
823 }
824 #endif /* CONFIG_PPP_FILTER */
825
826 #ifdef CONFIG_PPP_MULTILINK
827 case PPPIOCSMRRU:
828 if (get_user(val, p))
829 break;
830 ppp_recv_lock(ppp);
831 ppp->mrru = val;
832 ppp_recv_unlock(ppp);
833 err = 0;
834 break;
835 #endif /* CONFIG_PPP_MULTILINK */
836
837 default:
838 err = -ENOTTY;
839 }
840
841 out:
842 mutex_unlock(&ppp_mutex);
843
844 return err;
845 }
846
847 #ifdef CONFIG_COMPAT
848 struct ppp_option_data32 {
849 compat_uptr_t ptr;
850 u32 length;
851 compat_int_t transmit;
852 };
853 #define PPPIOCSCOMPRESS32 _IOW('t', 77, struct ppp_option_data32)
854
ppp_compat_ioctl(struct file * file,unsigned int cmd,unsigned long arg)855 static long ppp_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
856 {
857 struct ppp_file *pf;
858 int err = -ENOIOCTLCMD;
859 void __user *argp = (void __user *)arg;
860
861 mutex_lock(&ppp_mutex);
862
863 pf = file->private_data;
864 if (pf && pf->kind == INTERFACE) {
865 struct ppp *ppp = PF_TO_PPP(pf);
866 switch (cmd) {
867 #ifdef CONFIG_PPP_FILTER
868 case PPPIOCSPASS32:
869 case PPPIOCSACTIVE32:
870 {
871 struct bpf_prog *filter = compat_ppp_get_filter(argp);
872 struct bpf_prog **which;
873
874 if (IS_ERR(filter)) {
875 err = PTR_ERR(filter);
876 break;
877 }
878 if (cmd == PPPIOCSPASS32)
879 which = &ppp->pass_filter;
880 else
881 which = &ppp->active_filter;
882 ppp_lock(ppp);
883 if (*which)
884 bpf_prog_destroy(*which);
885 *which = filter;
886 ppp_unlock(ppp);
887 err = 0;
888 break;
889 }
890 #endif /* CONFIG_PPP_FILTER */
891 case PPPIOCSCOMPRESS32:
892 {
893 struct ppp_option_data32 data32;
894 if (copy_from_user(&data32, argp, sizeof(data32))) {
895 err = -EFAULT;
896 } else {
897 struct ppp_option_data data = {
898 .ptr = compat_ptr(data32.ptr),
899 .length = data32.length,
900 .transmit = data32.transmit
901 };
902 err = ppp_set_compress(ppp, &data);
903 }
904 break;
905 }
906 }
907 }
908 mutex_unlock(&ppp_mutex);
909
910 /* all other commands have compatible arguments */
911 if (err == -ENOIOCTLCMD)
912 err = ppp_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
913
914 return err;
915 }
916 #endif
917
ppp_unattached_ioctl(struct net * net,struct ppp_file * pf,struct file * file,unsigned int cmd,unsigned long arg)918 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
919 struct file *file, unsigned int cmd, unsigned long arg)
920 {
921 int unit, err = -EFAULT;
922 struct ppp *ppp;
923 struct channel *chan;
924 struct ppp_net *pn;
925 int __user *p = (int __user *)arg;
926
927 switch (cmd) {
928 case PPPIOCNEWUNIT:
929 /* Create a new ppp unit */
930 if (get_user(unit, p))
931 break;
932 err = ppp_create_interface(net, file, &unit);
933 if (err < 0)
934 break;
935
936 err = -EFAULT;
937 if (put_user(unit, p))
938 break;
939 err = 0;
940 break;
941
942 case PPPIOCATTACH:
943 /* Attach to an existing ppp unit */
944 if (get_user(unit, p))
945 break;
946 err = -ENXIO;
947 pn = ppp_pernet(net);
948 mutex_lock(&pn->all_ppp_mutex);
949 ppp = ppp_find_unit(pn, unit);
950 if (ppp) {
951 refcount_inc(&ppp->file.refcnt);
952 file->private_data = &ppp->file;
953 err = 0;
954 }
955 mutex_unlock(&pn->all_ppp_mutex);
956 break;
957
958 case PPPIOCATTCHAN:
959 if (get_user(unit, p))
960 break;
961 err = -ENXIO;
962 pn = ppp_pernet(net);
963 spin_lock_bh(&pn->all_channels_lock);
964 chan = ppp_find_channel(pn, unit);
965 if (chan) {
966 refcount_inc(&chan->file.refcnt);
967 file->private_data = &chan->file;
968 err = 0;
969 }
970 spin_unlock_bh(&pn->all_channels_lock);
971 break;
972
973 default:
974 err = -ENOTTY;
975 }
976
977 return err;
978 }
979
980 static const struct file_operations ppp_device_fops = {
981 .owner = THIS_MODULE,
982 .read = ppp_read,
983 .write = ppp_write,
984 .poll = ppp_poll,
985 .unlocked_ioctl = ppp_ioctl,
986 #ifdef CONFIG_COMPAT
987 .compat_ioctl = ppp_compat_ioctl,
988 #endif
989 .open = ppp_open,
990 .release = ppp_release,
991 .llseek = noop_llseek,
992 };
993
ppp_init_net(struct net * net)994 static __net_init int ppp_init_net(struct net *net)
995 {
996 struct ppp_net *pn = net_generic(net, ppp_net_id);
997
998 idr_init(&pn->units_idr);
999 mutex_init(&pn->all_ppp_mutex);
1000
1001 INIT_LIST_HEAD(&pn->all_channels);
1002 INIT_LIST_HEAD(&pn->new_channels);
1003
1004 spin_lock_init(&pn->all_channels_lock);
1005
1006 return 0;
1007 }
1008
ppp_exit_net(struct net * net)1009 static __net_exit void ppp_exit_net(struct net *net)
1010 {
1011 struct ppp_net *pn = net_generic(net, ppp_net_id);
1012 struct net_device *dev;
1013 struct net_device *aux;
1014 struct ppp *ppp;
1015 LIST_HEAD(list);
1016 int id;
1017
1018 rtnl_lock();
1019 for_each_netdev_safe(net, dev, aux) {
1020 if (dev->netdev_ops == &ppp_netdev_ops)
1021 unregister_netdevice_queue(dev, &list);
1022 }
1023
1024 idr_for_each_entry(&pn->units_idr, ppp, id)
1025 /* Skip devices already unregistered by previous loop */
1026 if (!net_eq(dev_net(ppp->dev), net))
1027 unregister_netdevice_queue(ppp->dev, &list);
1028
1029 unregister_netdevice_many(&list);
1030 rtnl_unlock();
1031
1032 mutex_destroy(&pn->all_ppp_mutex);
1033 idr_destroy(&pn->units_idr);
1034 WARN_ON_ONCE(!list_empty(&pn->all_channels));
1035 WARN_ON_ONCE(!list_empty(&pn->new_channels));
1036 }
1037
1038 static struct pernet_operations ppp_net_ops = {
1039 .init = ppp_init_net,
1040 .exit = ppp_exit_net,
1041 .id = &ppp_net_id,
1042 .size = sizeof(struct ppp_net),
1043 };
1044
ppp_unit_register(struct ppp * ppp,int unit,bool ifname_is_set)1045 static int ppp_unit_register(struct ppp *ppp, int unit, bool ifname_is_set)
1046 {
1047 struct ppp_net *pn = ppp_pernet(ppp->ppp_net);
1048 int ret;
1049
1050 mutex_lock(&pn->all_ppp_mutex);
1051
1052 if (unit < 0) {
1053 ret = unit_get(&pn->units_idr, ppp, 0);
1054 if (ret < 0)
1055 goto err;
1056 if (!ifname_is_set) {
1057 while (1) {
1058 snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ret);
1059 if (!__dev_get_by_name(ppp->ppp_net, ppp->dev->name))
1060 break;
1061 unit_put(&pn->units_idr, ret);
1062 ret = unit_get(&pn->units_idr, ppp, ret + 1);
1063 if (ret < 0)
1064 goto err;
1065 }
1066 }
1067 } else {
1068 /* Caller asked for a specific unit number. Fail with -EEXIST
1069 * if unavailable. For backward compatibility, return -EEXIST
1070 * too if idr allocation fails; this makes pppd retry without
1071 * requesting a specific unit number.
1072 */
1073 if (unit_find(&pn->units_idr, unit)) {
1074 ret = -EEXIST;
1075 goto err;
1076 }
1077 ret = unit_set(&pn->units_idr, ppp, unit);
1078 if (ret < 0) {
1079 /* Rewrite error for backward compatibility */
1080 ret = -EEXIST;
1081 goto err;
1082 }
1083 }
1084 ppp->file.index = ret;
1085
1086 if (!ifname_is_set)
1087 snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ppp->file.index);
1088
1089 mutex_unlock(&pn->all_ppp_mutex);
1090
1091 ret = register_netdevice(ppp->dev);
1092 if (ret < 0)
1093 goto err_unit;
1094
1095 atomic_inc(&ppp_unit_count);
1096
1097 return 0;
1098
1099 err_unit:
1100 mutex_lock(&pn->all_ppp_mutex);
1101 unit_put(&pn->units_idr, ppp->file.index);
1102 err:
1103 mutex_unlock(&pn->all_ppp_mutex);
1104
1105 return ret;
1106 }
1107
ppp_dev_configure(struct net * src_net,struct net_device * dev,const struct ppp_config * conf)1108 static int ppp_dev_configure(struct net *src_net, struct net_device *dev,
1109 const struct ppp_config *conf)
1110 {
1111 struct ppp *ppp = netdev_priv(dev);
1112 int indx;
1113 int err;
1114 int cpu;
1115
1116 ppp->dev = dev;
1117 ppp->ppp_net = src_net;
1118 ppp->mru = PPP_MRU;
1119 ppp->owner = conf->file;
1120
1121 init_ppp_file(&ppp->file, INTERFACE);
1122 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
1123
1124 for (indx = 0; indx < NUM_NP; ++indx)
1125 ppp->npmode[indx] = NPMODE_PASS;
1126 INIT_LIST_HEAD(&ppp->channels);
1127 spin_lock_init(&ppp->rlock);
1128 spin_lock_init(&ppp->wlock);
1129
1130 ppp->xmit_recursion = alloc_percpu(int);
1131 if (!ppp->xmit_recursion) {
1132 err = -ENOMEM;
1133 goto err1;
1134 }
1135 for_each_possible_cpu(cpu)
1136 (*per_cpu_ptr(ppp->xmit_recursion, cpu)) = 0;
1137
1138 #ifdef CONFIG_PPP_MULTILINK
1139 ppp->minseq = -1;
1140 skb_queue_head_init(&ppp->mrq);
1141 #endif /* CONFIG_PPP_MULTILINK */
1142 #ifdef CONFIG_PPP_FILTER
1143 ppp->pass_filter = NULL;
1144 ppp->active_filter = NULL;
1145 #endif /* CONFIG_PPP_FILTER */
1146
1147 err = ppp_unit_register(ppp, conf->unit, conf->ifname_is_set);
1148 if (err < 0)
1149 goto err2;
1150
1151 conf->file->private_data = &ppp->file;
1152
1153 return 0;
1154 err2:
1155 free_percpu(ppp->xmit_recursion);
1156 err1:
1157 return err;
1158 }
1159
1160 static const struct nla_policy ppp_nl_policy[IFLA_PPP_MAX + 1] = {
1161 [IFLA_PPP_DEV_FD] = { .type = NLA_S32 },
1162 };
1163
ppp_nl_validate(struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)1164 static int ppp_nl_validate(struct nlattr *tb[], struct nlattr *data[],
1165 struct netlink_ext_ack *extack)
1166 {
1167 if (!data)
1168 return -EINVAL;
1169
1170 if (!data[IFLA_PPP_DEV_FD])
1171 return -EINVAL;
1172 if (nla_get_s32(data[IFLA_PPP_DEV_FD]) < 0)
1173 return -EBADF;
1174
1175 return 0;
1176 }
1177
ppp_nl_newlink(struct net * src_net,struct net_device * dev,struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)1178 static int ppp_nl_newlink(struct net *src_net, struct net_device *dev,
1179 struct nlattr *tb[], struct nlattr *data[],
1180 struct netlink_ext_ack *extack)
1181 {
1182 struct ppp_config conf = {
1183 .unit = -1,
1184 .ifname_is_set = true,
1185 };
1186 struct file *file;
1187 int err;
1188
1189 file = fget(nla_get_s32(data[IFLA_PPP_DEV_FD]));
1190 if (!file)
1191 return -EBADF;
1192
1193 /* rtnl_lock is already held here, but ppp_create_interface() locks
1194 * ppp_mutex before holding rtnl_lock. Using mutex_trylock() avoids
1195 * possible deadlock due to lock order inversion, at the cost of
1196 * pushing the problem back to userspace.
1197 */
1198 if (!mutex_trylock(&ppp_mutex)) {
1199 err = -EBUSY;
1200 goto out;
1201 }
1202
1203 if (file->f_op != &ppp_device_fops || file->private_data) {
1204 err = -EBADF;
1205 goto out_unlock;
1206 }
1207
1208 conf.file = file;
1209
1210 /* Don't use device name generated by the rtnetlink layer when ifname
1211 * isn't specified. Let ppp_dev_configure() set the device name using
1212 * the PPP unit identifer as suffix (i.e. ppp<unit_id>). This allows
1213 * userspace to infer the device name using to the PPPIOCGUNIT ioctl.
1214 */
1215 if (!tb[IFLA_IFNAME] || !nla_len(tb[IFLA_IFNAME]) || !*(char *)nla_data(tb[IFLA_IFNAME]))
1216 conf.ifname_is_set = false;
1217
1218 err = ppp_dev_configure(src_net, dev, &conf);
1219
1220 out_unlock:
1221 mutex_unlock(&ppp_mutex);
1222 out:
1223 fput(file);
1224
1225 return err;
1226 }
1227
ppp_nl_dellink(struct net_device * dev,struct list_head * head)1228 static void ppp_nl_dellink(struct net_device *dev, struct list_head *head)
1229 {
1230 unregister_netdevice_queue(dev, head);
1231 }
1232
ppp_nl_get_size(const struct net_device * dev)1233 static size_t ppp_nl_get_size(const struct net_device *dev)
1234 {
1235 return 0;
1236 }
1237
ppp_nl_fill_info(struct sk_buff * skb,const struct net_device * dev)1238 static int ppp_nl_fill_info(struct sk_buff *skb, const struct net_device *dev)
1239 {
1240 return 0;
1241 }
1242
ppp_nl_get_link_net(const struct net_device * dev)1243 static struct net *ppp_nl_get_link_net(const struct net_device *dev)
1244 {
1245 struct ppp *ppp = netdev_priv(dev);
1246
1247 return ppp->ppp_net;
1248 }
1249
1250 static struct rtnl_link_ops ppp_link_ops __read_mostly = {
1251 .kind = "ppp",
1252 .maxtype = IFLA_PPP_MAX,
1253 .policy = ppp_nl_policy,
1254 .priv_size = sizeof(struct ppp),
1255 .setup = ppp_setup,
1256 .validate = ppp_nl_validate,
1257 .newlink = ppp_nl_newlink,
1258 .dellink = ppp_nl_dellink,
1259 .get_size = ppp_nl_get_size,
1260 .fill_info = ppp_nl_fill_info,
1261 .get_link_net = ppp_nl_get_link_net,
1262 };
1263
1264 #define PPP_MAJOR 108
1265
1266 /* Called at boot time if ppp is compiled into the kernel,
1267 or at module load time (from init_module) if compiled as a module. */
ppp_init(void)1268 static int __init ppp_init(void)
1269 {
1270 int err;
1271
1272 pr_info("PPP generic driver version " PPP_VERSION "\n");
1273
1274 err = register_pernet_device(&ppp_net_ops);
1275 if (err) {
1276 pr_err("failed to register PPP pernet device (%d)\n", err);
1277 goto out;
1278 }
1279
1280 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
1281 if (err) {
1282 pr_err("failed to register PPP device (%d)\n", err);
1283 goto out_net;
1284 }
1285
1286 ppp_class = class_create(THIS_MODULE, "ppp");
1287 if (IS_ERR(ppp_class)) {
1288 err = PTR_ERR(ppp_class);
1289 goto out_chrdev;
1290 }
1291
1292 err = rtnl_link_register(&ppp_link_ops);
1293 if (err) {
1294 pr_err("failed to register rtnetlink PPP handler\n");
1295 goto out_class;
1296 }
1297
1298 /* not a big deal if we fail here :-) */
1299 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
1300
1301 return 0;
1302
1303 out_class:
1304 class_destroy(ppp_class);
1305 out_chrdev:
1306 unregister_chrdev(PPP_MAJOR, "ppp");
1307 out_net:
1308 unregister_pernet_device(&ppp_net_ops);
1309 out:
1310 return err;
1311 }
1312
1313 /*
1314 * Network interface unit routines.
1315 */
1316 static netdev_tx_t
ppp_start_xmit(struct sk_buff * skb,struct net_device * dev)1317 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
1318 {
1319 struct ppp *ppp = netdev_priv(dev);
1320 int npi, proto;
1321 unsigned char *pp;
1322
1323 npi = ethertype_to_npindex(ntohs(skb->protocol));
1324 if (npi < 0)
1325 goto outf;
1326
1327 /* Drop, accept or reject the packet */
1328 switch (ppp->npmode[npi]) {
1329 case NPMODE_PASS:
1330 break;
1331 case NPMODE_QUEUE:
1332 /* it would be nice to have a way to tell the network
1333 system to queue this one up for later. */
1334 goto outf;
1335 case NPMODE_DROP:
1336 case NPMODE_ERROR:
1337 goto outf;
1338 }
1339
1340 /* Put the 2-byte PPP protocol number on the front,
1341 making sure there is room for the address and control fields. */
1342 if (skb_cow_head(skb, PPP_HDRLEN))
1343 goto outf;
1344
1345 pp = skb_push(skb, 2);
1346 proto = npindex_to_proto[npi];
1347 put_unaligned_be16(proto, pp);
1348
1349 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, dev_net(dev)));
1350 ppp_xmit_process(ppp, skb);
1351
1352 return NETDEV_TX_OK;
1353
1354 outf:
1355 kfree_skb(skb);
1356 ++dev->stats.tx_dropped;
1357 return NETDEV_TX_OK;
1358 }
1359
1360 static int
ppp_net_ioctl(struct net_device * dev,struct ifreq * ifr,int cmd)1361 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1362 {
1363 struct ppp *ppp = netdev_priv(dev);
1364 int err = -EFAULT;
1365 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
1366 struct ppp_stats stats;
1367 struct ppp_comp_stats cstats;
1368 char *vers;
1369
1370 switch (cmd) {
1371 case SIOCGPPPSTATS:
1372 ppp_get_stats(ppp, &stats);
1373 if (copy_to_user(addr, &stats, sizeof(stats)))
1374 break;
1375 err = 0;
1376 break;
1377
1378 case SIOCGPPPCSTATS:
1379 memset(&cstats, 0, sizeof(cstats));
1380 if (ppp->xc_state)
1381 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
1382 if (ppp->rc_state)
1383 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
1384 if (copy_to_user(addr, &cstats, sizeof(cstats)))
1385 break;
1386 err = 0;
1387 break;
1388
1389 case SIOCGPPPVER:
1390 vers = PPP_VERSION;
1391 if (copy_to_user(addr, vers, strlen(vers) + 1))
1392 break;
1393 err = 0;
1394 break;
1395
1396 default:
1397 err = -EINVAL;
1398 }
1399
1400 return err;
1401 }
1402
1403 static void
ppp_get_stats64(struct net_device * dev,struct rtnl_link_stats64 * stats64)1404 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64)
1405 {
1406 struct ppp *ppp = netdev_priv(dev);
1407
1408 ppp_recv_lock(ppp);
1409 stats64->rx_packets = ppp->stats64.rx_packets;
1410 stats64->rx_bytes = ppp->stats64.rx_bytes;
1411 ppp_recv_unlock(ppp);
1412
1413 ppp_xmit_lock(ppp);
1414 stats64->tx_packets = ppp->stats64.tx_packets;
1415 stats64->tx_bytes = ppp->stats64.tx_bytes;
1416 ppp_xmit_unlock(ppp);
1417
1418 stats64->rx_errors = dev->stats.rx_errors;
1419 stats64->tx_errors = dev->stats.tx_errors;
1420 stats64->rx_dropped = dev->stats.rx_dropped;
1421 stats64->tx_dropped = dev->stats.tx_dropped;
1422 stats64->rx_length_errors = dev->stats.rx_length_errors;
1423 }
1424
ppp_dev_init(struct net_device * dev)1425 static int ppp_dev_init(struct net_device *dev)
1426 {
1427 struct ppp *ppp;
1428
1429 netdev_lockdep_set_classes(dev);
1430
1431 ppp = netdev_priv(dev);
1432 /* Let the netdevice take a reference on the ppp file. This ensures
1433 * that ppp_destroy_interface() won't run before the device gets
1434 * unregistered.
1435 */
1436 refcount_inc(&ppp->file.refcnt);
1437
1438 return 0;
1439 }
1440
ppp_dev_uninit(struct net_device * dev)1441 static void ppp_dev_uninit(struct net_device *dev)
1442 {
1443 struct ppp *ppp = netdev_priv(dev);
1444 struct ppp_net *pn = ppp_pernet(ppp->ppp_net);
1445
1446 ppp_lock(ppp);
1447 ppp->closing = 1;
1448 ppp_unlock(ppp);
1449
1450 mutex_lock(&pn->all_ppp_mutex);
1451 unit_put(&pn->units_idr, ppp->file.index);
1452 mutex_unlock(&pn->all_ppp_mutex);
1453
1454 ppp->owner = NULL;
1455
1456 ppp->file.dead = 1;
1457 wake_up_interruptible(&ppp->file.rwait);
1458 }
1459
ppp_dev_priv_destructor(struct net_device * dev)1460 static void ppp_dev_priv_destructor(struct net_device *dev)
1461 {
1462 struct ppp *ppp;
1463
1464 ppp = netdev_priv(dev);
1465 if (refcount_dec_and_test(&ppp->file.refcnt))
1466 ppp_destroy_interface(ppp);
1467 }
1468
1469 static const struct net_device_ops ppp_netdev_ops = {
1470 .ndo_init = ppp_dev_init,
1471 .ndo_uninit = ppp_dev_uninit,
1472 .ndo_start_xmit = ppp_start_xmit,
1473 .ndo_do_ioctl = ppp_net_ioctl,
1474 .ndo_get_stats64 = ppp_get_stats64,
1475 };
1476
1477 static struct device_type ppp_type = {
1478 .name = "ppp",
1479 };
1480
ppp_setup(struct net_device * dev)1481 static void ppp_setup(struct net_device *dev)
1482 {
1483 dev->netdev_ops = &ppp_netdev_ops;
1484 SET_NETDEV_DEVTYPE(dev, &ppp_type);
1485
1486 dev->features |= NETIF_F_LLTX;
1487
1488 dev->hard_header_len = PPP_HDRLEN;
1489 dev->mtu = PPP_MRU;
1490 dev->addr_len = 0;
1491 dev->tx_queue_len = 3;
1492 dev->type = ARPHRD_PPP;
1493 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1494 dev->priv_destructor = ppp_dev_priv_destructor;
1495 netif_keep_dst(dev);
1496 }
1497
1498 /*
1499 * Transmit-side routines.
1500 */
1501
1502 /* Called to do any work queued up on the transmit side that can now be done */
__ppp_xmit_process(struct ppp * ppp,struct sk_buff * skb)1503 static void __ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb)
1504 {
1505 ppp_xmit_lock(ppp);
1506 if (!ppp->closing) {
1507 ppp_push(ppp);
1508
1509 if (skb)
1510 skb_queue_tail(&ppp->file.xq, skb);
1511 while (!ppp->xmit_pending &&
1512 (skb = skb_dequeue(&ppp->file.xq)))
1513 ppp_send_frame(ppp, skb);
1514 /* If there's no work left to do, tell the core net
1515 code that we can accept some more. */
1516 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1517 netif_wake_queue(ppp->dev);
1518 else
1519 netif_stop_queue(ppp->dev);
1520 } else {
1521 kfree_skb(skb);
1522 }
1523 ppp_xmit_unlock(ppp);
1524 }
1525
ppp_xmit_process(struct ppp * ppp,struct sk_buff * skb)1526 static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb)
1527 {
1528 local_bh_disable();
1529
1530 if (unlikely(*this_cpu_ptr(ppp->xmit_recursion)))
1531 goto err;
1532
1533 (*this_cpu_ptr(ppp->xmit_recursion))++;
1534 __ppp_xmit_process(ppp, skb);
1535 (*this_cpu_ptr(ppp->xmit_recursion))--;
1536
1537 local_bh_enable();
1538
1539 return;
1540
1541 err:
1542 local_bh_enable();
1543
1544 kfree_skb(skb);
1545
1546 if (net_ratelimit())
1547 netdev_err(ppp->dev, "recursion detected\n");
1548 }
1549
1550 static inline struct sk_buff *
pad_compress_skb(struct ppp * ppp,struct sk_buff * skb)1551 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1552 {
1553 struct sk_buff *new_skb;
1554 int len;
1555 int new_skb_size = ppp->dev->mtu +
1556 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1557 int compressor_skb_size = ppp->dev->mtu +
1558 ppp->xcomp->comp_extra + PPP_HDRLEN;
1559 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1560 if (!new_skb) {
1561 if (net_ratelimit())
1562 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n");
1563 return NULL;
1564 }
1565 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1566 skb_reserve(new_skb,
1567 ppp->dev->hard_header_len - PPP_HDRLEN);
1568
1569 /* compressor still expects A/C bytes in hdr */
1570 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1571 new_skb->data, skb->len + 2,
1572 compressor_skb_size);
1573 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1574 consume_skb(skb);
1575 skb = new_skb;
1576 skb_put(skb, len);
1577 skb_pull(skb, 2); /* pull off A/C bytes */
1578 } else if (len == 0) {
1579 /* didn't compress, or CCP not up yet */
1580 consume_skb(new_skb);
1581 new_skb = skb;
1582 } else {
1583 /*
1584 * (len < 0)
1585 * MPPE requires that we do not send unencrypted
1586 * frames. The compressor will return -1 if we
1587 * should drop the frame. We cannot simply test
1588 * the compress_proto because MPPE and MPPC share
1589 * the same number.
1590 */
1591 if (net_ratelimit())
1592 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n");
1593 kfree_skb(skb);
1594 consume_skb(new_skb);
1595 new_skb = NULL;
1596 }
1597 return new_skb;
1598 }
1599
1600 /*
1601 * Compress and send a frame.
1602 * The caller should have locked the xmit path,
1603 * and xmit_pending should be 0.
1604 */
1605 static void
ppp_send_frame(struct ppp * ppp,struct sk_buff * skb)1606 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1607 {
1608 int proto = PPP_PROTO(skb);
1609 struct sk_buff *new_skb;
1610 int len;
1611 unsigned char *cp;
1612
1613 if (proto < 0x8000) {
1614 #ifdef CONFIG_PPP_FILTER
1615 /* check if we should pass this packet */
1616 /* the filter instructions are constructed assuming
1617 a four-byte PPP header on each packet */
1618 *(u8 *)skb_push(skb, 2) = 1;
1619 if (ppp->pass_filter &&
1620 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
1621 if (ppp->debug & 1)
1622 netdev_printk(KERN_DEBUG, ppp->dev,
1623 "PPP: outbound frame "
1624 "not passed\n");
1625 kfree_skb(skb);
1626 return;
1627 }
1628 /* if this packet passes the active filter, record the time */
1629 if (!(ppp->active_filter &&
1630 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
1631 ppp->last_xmit = jiffies;
1632 skb_pull(skb, 2);
1633 #else
1634 /* for data packets, record the time */
1635 ppp->last_xmit = jiffies;
1636 #endif /* CONFIG_PPP_FILTER */
1637 }
1638
1639 ++ppp->stats64.tx_packets;
1640 ppp->stats64.tx_bytes += skb->len - PPP_PROTO_LEN;
1641
1642 switch (proto) {
1643 case PPP_IP:
1644 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1645 break;
1646 /* try to do VJ TCP header compression */
1647 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1648 GFP_ATOMIC);
1649 if (!new_skb) {
1650 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n");
1651 goto drop;
1652 }
1653 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1654 cp = skb->data + 2;
1655 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1656 new_skb->data + 2, &cp,
1657 !(ppp->flags & SC_NO_TCP_CCID));
1658 if (cp == skb->data + 2) {
1659 /* didn't compress */
1660 consume_skb(new_skb);
1661 } else {
1662 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1663 proto = PPP_VJC_COMP;
1664 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1665 } else {
1666 proto = PPP_VJC_UNCOMP;
1667 cp[0] = skb->data[2];
1668 }
1669 consume_skb(skb);
1670 skb = new_skb;
1671 cp = skb_put(skb, len + 2);
1672 cp[0] = 0;
1673 cp[1] = proto;
1674 }
1675 break;
1676
1677 case PPP_CCP:
1678 /* peek at outbound CCP frames */
1679 ppp_ccp_peek(ppp, skb, 0);
1680 break;
1681 }
1682
1683 /* try to do packet compression */
1684 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state &&
1685 proto != PPP_LCP && proto != PPP_CCP) {
1686 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1687 if (net_ratelimit())
1688 netdev_err(ppp->dev,
1689 "ppp: compression required but "
1690 "down - pkt dropped.\n");
1691 goto drop;
1692 }
1693 skb = pad_compress_skb(ppp, skb);
1694 if (!skb)
1695 goto drop;
1696 }
1697
1698 /*
1699 * If we are waiting for traffic (demand dialling),
1700 * queue it up for pppd to receive.
1701 */
1702 if (ppp->flags & SC_LOOP_TRAFFIC) {
1703 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1704 goto drop;
1705 skb_queue_tail(&ppp->file.rq, skb);
1706 wake_up_interruptible(&ppp->file.rwait);
1707 return;
1708 }
1709
1710 ppp->xmit_pending = skb;
1711 ppp_push(ppp);
1712 return;
1713
1714 drop:
1715 kfree_skb(skb);
1716 ++ppp->dev->stats.tx_errors;
1717 }
1718
1719 /*
1720 * Try to send the frame in xmit_pending.
1721 * The caller should have the xmit path locked.
1722 */
1723 static void
ppp_push(struct ppp * ppp)1724 ppp_push(struct ppp *ppp)
1725 {
1726 struct list_head *list;
1727 struct channel *pch;
1728 struct sk_buff *skb = ppp->xmit_pending;
1729
1730 if (!skb)
1731 return;
1732
1733 list = &ppp->channels;
1734 if (list_empty(list)) {
1735 /* nowhere to send the packet, just drop it */
1736 ppp->xmit_pending = NULL;
1737 kfree_skb(skb);
1738 return;
1739 }
1740
1741 if ((ppp->flags & SC_MULTILINK) == 0) {
1742 /* not doing multilink: send it down the first channel */
1743 list = list->next;
1744 pch = list_entry(list, struct channel, clist);
1745
1746 spin_lock(&pch->downl);
1747 if (pch->chan) {
1748 if (pch->chan->ops->start_xmit(pch->chan, skb))
1749 ppp->xmit_pending = NULL;
1750 } else {
1751 /* channel got unregistered */
1752 kfree_skb(skb);
1753 ppp->xmit_pending = NULL;
1754 }
1755 spin_unlock(&pch->downl);
1756 return;
1757 }
1758
1759 #ifdef CONFIG_PPP_MULTILINK
1760 /* Multilink: fragment the packet over as many links
1761 as can take the packet at the moment. */
1762 if (!ppp_mp_explode(ppp, skb))
1763 return;
1764 #endif /* CONFIG_PPP_MULTILINK */
1765
1766 ppp->xmit_pending = NULL;
1767 kfree_skb(skb);
1768 }
1769
1770 #ifdef CONFIG_PPP_MULTILINK
1771 static bool mp_protocol_compress __read_mostly = true;
1772 module_param(mp_protocol_compress, bool, 0644);
1773 MODULE_PARM_DESC(mp_protocol_compress,
1774 "compress protocol id in multilink fragments");
1775
1776 /*
1777 * Divide a packet to be transmitted into fragments and
1778 * send them out the individual links.
1779 */
ppp_mp_explode(struct ppp * ppp,struct sk_buff * skb)1780 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1781 {
1782 int len, totlen;
1783 int i, bits, hdrlen, mtu;
1784 int flen;
1785 int navail, nfree, nzero;
1786 int nbigger;
1787 int totspeed;
1788 int totfree;
1789 unsigned char *p, *q;
1790 struct list_head *list;
1791 struct channel *pch;
1792 struct sk_buff *frag;
1793 struct ppp_channel *chan;
1794
1795 totspeed = 0; /*total bitrate of the bundle*/
1796 nfree = 0; /* # channels which have no packet already queued */
1797 navail = 0; /* total # of usable channels (not deregistered) */
1798 nzero = 0; /* number of channels with zero speed associated*/
1799 totfree = 0; /*total # of channels available and
1800 *having no queued packets before
1801 *starting the fragmentation*/
1802
1803 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1804 i = 0;
1805 list_for_each_entry(pch, &ppp->channels, clist) {
1806 if (pch->chan) {
1807 pch->avail = 1;
1808 navail++;
1809 pch->speed = pch->chan->speed;
1810 } else {
1811 pch->avail = 0;
1812 }
1813 if (pch->avail) {
1814 if (skb_queue_empty(&pch->file.xq) ||
1815 !pch->had_frag) {
1816 if (pch->speed == 0)
1817 nzero++;
1818 else
1819 totspeed += pch->speed;
1820
1821 pch->avail = 2;
1822 ++nfree;
1823 ++totfree;
1824 }
1825 if (!pch->had_frag && i < ppp->nxchan)
1826 ppp->nxchan = i;
1827 }
1828 ++i;
1829 }
1830 /*
1831 * Don't start sending this packet unless at least half of
1832 * the channels are free. This gives much better TCP
1833 * performance if we have a lot of channels.
1834 */
1835 if (nfree == 0 || nfree < navail / 2)
1836 return 0; /* can't take now, leave it in xmit_pending */
1837
1838 /* Do protocol field compression */
1839 p = skb->data;
1840 len = skb->len;
1841 if (*p == 0 && mp_protocol_compress) {
1842 ++p;
1843 --len;
1844 }
1845
1846 totlen = len;
1847 nbigger = len % nfree;
1848
1849 /* skip to the channel after the one we last used
1850 and start at that one */
1851 list = &ppp->channels;
1852 for (i = 0; i < ppp->nxchan; ++i) {
1853 list = list->next;
1854 if (list == &ppp->channels) {
1855 i = 0;
1856 break;
1857 }
1858 }
1859
1860 /* create a fragment for each channel */
1861 bits = B;
1862 while (len > 0) {
1863 list = list->next;
1864 if (list == &ppp->channels) {
1865 i = 0;
1866 continue;
1867 }
1868 pch = list_entry(list, struct channel, clist);
1869 ++i;
1870 if (!pch->avail)
1871 continue;
1872
1873 /*
1874 * Skip this channel if it has a fragment pending already and
1875 * we haven't given a fragment to all of the free channels.
1876 */
1877 if (pch->avail == 1) {
1878 if (nfree > 0)
1879 continue;
1880 } else {
1881 pch->avail = 1;
1882 }
1883
1884 /* check the channel's mtu and whether it is still attached. */
1885 spin_lock(&pch->downl);
1886 if (pch->chan == NULL) {
1887 /* can't use this channel, it's being deregistered */
1888 if (pch->speed == 0)
1889 nzero--;
1890 else
1891 totspeed -= pch->speed;
1892
1893 spin_unlock(&pch->downl);
1894 pch->avail = 0;
1895 totlen = len;
1896 totfree--;
1897 nfree--;
1898 if (--navail == 0)
1899 break;
1900 continue;
1901 }
1902
1903 /*
1904 *if the channel speed is not set divide
1905 *the packet evenly among the free channels;
1906 *otherwise divide it according to the speed
1907 *of the channel we are going to transmit on
1908 */
1909 flen = len;
1910 if (nfree > 0) {
1911 if (pch->speed == 0) {
1912 flen = len/nfree;
1913 if (nbigger > 0) {
1914 flen++;
1915 nbigger--;
1916 }
1917 } else {
1918 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
1919 ((totspeed*totfree)/pch->speed)) - hdrlen;
1920 if (nbigger > 0) {
1921 flen += ((totfree - nzero)*pch->speed)/totspeed;
1922 nbigger -= ((totfree - nzero)*pch->speed)/
1923 totspeed;
1924 }
1925 }
1926 nfree--;
1927 }
1928
1929 /*
1930 *check if we are on the last channel or
1931 *we exceded the length of the data to
1932 *fragment
1933 */
1934 if ((nfree <= 0) || (flen > len))
1935 flen = len;
1936 /*
1937 *it is not worth to tx on slow channels:
1938 *in that case from the resulting flen according to the
1939 *above formula will be equal or less than zero.
1940 *Skip the channel in this case
1941 */
1942 if (flen <= 0) {
1943 pch->avail = 2;
1944 spin_unlock(&pch->downl);
1945 continue;
1946 }
1947
1948 /*
1949 * hdrlen includes the 2-byte PPP protocol field, but the
1950 * MTU counts only the payload excluding the protocol field.
1951 * (RFC1661 Section 2)
1952 */
1953 mtu = pch->chan->mtu - (hdrlen - 2);
1954 if (mtu < 4)
1955 mtu = 4;
1956 if (flen > mtu)
1957 flen = mtu;
1958 if (flen == len)
1959 bits |= E;
1960 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1961 if (!frag)
1962 goto noskb;
1963 q = skb_put(frag, flen + hdrlen);
1964
1965 /* make the MP header */
1966 put_unaligned_be16(PPP_MP, q);
1967 if (ppp->flags & SC_MP_XSHORTSEQ) {
1968 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1969 q[3] = ppp->nxseq;
1970 } else {
1971 q[2] = bits;
1972 q[3] = ppp->nxseq >> 16;
1973 q[4] = ppp->nxseq >> 8;
1974 q[5] = ppp->nxseq;
1975 }
1976
1977 memcpy(q + hdrlen, p, flen);
1978
1979 /* try to send it down the channel */
1980 chan = pch->chan;
1981 if (!skb_queue_empty(&pch->file.xq) ||
1982 !chan->ops->start_xmit(chan, frag))
1983 skb_queue_tail(&pch->file.xq, frag);
1984 pch->had_frag = 1;
1985 p += flen;
1986 len -= flen;
1987 ++ppp->nxseq;
1988 bits = 0;
1989 spin_unlock(&pch->downl);
1990 }
1991 ppp->nxchan = i;
1992
1993 return 1;
1994
1995 noskb:
1996 spin_unlock(&pch->downl);
1997 if (ppp->debug & 1)
1998 netdev_err(ppp->dev, "PPP: no memory (fragment)\n");
1999 ++ppp->dev->stats.tx_errors;
2000 ++ppp->nxseq;
2001 return 1; /* abandon the frame */
2002 }
2003 #endif /* CONFIG_PPP_MULTILINK */
2004
2005 /* Try to send data out on a channel */
__ppp_channel_push(struct channel * pch)2006 static void __ppp_channel_push(struct channel *pch)
2007 {
2008 struct sk_buff *skb;
2009 struct ppp *ppp;
2010
2011 spin_lock(&pch->downl);
2012 if (pch->chan) {
2013 while (!skb_queue_empty(&pch->file.xq)) {
2014 skb = skb_dequeue(&pch->file.xq);
2015 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
2016 /* put the packet back and try again later */
2017 skb_queue_head(&pch->file.xq, skb);
2018 break;
2019 }
2020 }
2021 } else {
2022 /* channel got deregistered */
2023 skb_queue_purge(&pch->file.xq);
2024 }
2025 spin_unlock(&pch->downl);
2026 /* see if there is anything from the attached unit to be sent */
2027 if (skb_queue_empty(&pch->file.xq)) {
2028 ppp = pch->ppp;
2029 if (ppp)
2030 __ppp_xmit_process(ppp, NULL);
2031 }
2032 }
2033
ppp_channel_push(struct channel * pch)2034 static void ppp_channel_push(struct channel *pch)
2035 {
2036 read_lock_bh(&pch->upl);
2037 if (pch->ppp) {
2038 (*this_cpu_ptr(pch->ppp->xmit_recursion))++;
2039 __ppp_channel_push(pch);
2040 (*this_cpu_ptr(pch->ppp->xmit_recursion))--;
2041 } else {
2042 __ppp_channel_push(pch);
2043 }
2044 read_unlock_bh(&pch->upl);
2045 }
2046
2047 /*
2048 * Receive-side routines.
2049 */
2050
2051 struct ppp_mp_skb_parm {
2052 u32 sequence;
2053 u8 BEbits;
2054 };
2055 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb))
2056
2057 static inline void
ppp_do_recv(struct ppp * ppp,struct sk_buff * skb,struct channel * pch)2058 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
2059 {
2060 ppp_recv_lock(ppp);
2061 if (!ppp->closing)
2062 ppp_receive_frame(ppp, skb, pch);
2063 else
2064 kfree_skb(skb);
2065 ppp_recv_unlock(ppp);
2066 }
2067
2068 /**
2069 * __ppp_decompress_proto - Decompress protocol field, slim version.
2070 * @skb: Socket buffer where protocol field should be decompressed. It must have
2071 * at least 1 byte of head room and 1 byte of linear data. First byte of
2072 * data must be a protocol field byte.
2073 *
2074 * Decompress protocol field in PPP header if it's compressed, e.g. when
2075 * Protocol-Field-Compression (PFC) was negotiated. No checks w.r.t. skb data
2076 * length are done in this function.
2077 */
__ppp_decompress_proto(struct sk_buff * skb)2078 static void __ppp_decompress_proto(struct sk_buff *skb)
2079 {
2080 if (skb->data[0] & 0x01)
2081 *(u8 *)skb_push(skb, 1) = 0x00;
2082 }
2083
2084 /**
2085 * ppp_decompress_proto - Check skb data room and decompress protocol field.
2086 * @skb: Socket buffer where protocol field should be decompressed. First byte
2087 * of data must be a protocol field byte.
2088 *
2089 * Decompress protocol field in PPP header if it's compressed, e.g. when
2090 * Protocol-Field-Compression (PFC) was negotiated. This function also makes
2091 * sure that skb data room is sufficient for Protocol field, before and after
2092 * decompression.
2093 *
2094 * Return: true - decompressed successfully, false - not enough room in skb.
2095 */
ppp_decompress_proto(struct sk_buff * skb)2096 static bool ppp_decompress_proto(struct sk_buff *skb)
2097 {
2098 /* At least one byte should be present (if protocol is compressed) */
2099 if (!pskb_may_pull(skb, 1))
2100 return false;
2101
2102 __ppp_decompress_proto(skb);
2103
2104 /* Protocol field should occupy 2 bytes when not compressed */
2105 return pskb_may_pull(skb, 2);
2106 }
2107
2108 void
ppp_input(struct ppp_channel * chan,struct sk_buff * skb)2109 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
2110 {
2111 struct channel *pch = chan->ppp;
2112 int proto;
2113
2114 if (!pch) {
2115 kfree_skb(skb);
2116 return;
2117 }
2118
2119 read_lock_bh(&pch->upl);
2120 if (!ppp_decompress_proto(skb)) {
2121 kfree_skb(skb);
2122 if (pch->ppp) {
2123 ++pch->ppp->dev->stats.rx_length_errors;
2124 ppp_receive_error(pch->ppp);
2125 }
2126 goto done;
2127 }
2128
2129 proto = PPP_PROTO(skb);
2130 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
2131 /* put it on the channel queue */
2132 skb_queue_tail(&pch->file.rq, skb);
2133 /* drop old frames if queue too long */
2134 while (pch->file.rq.qlen > PPP_MAX_RQLEN &&
2135 (skb = skb_dequeue(&pch->file.rq)))
2136 kfree_skb(skb);
2137 wake_up_interruptible(&pch->file.rwait);
2138 } else {
2139 ppp_do_recv(pch->ppp, skb, pch);
2140 }
2141
2142 done:
2143 read_unlock_bh(&pch->upl);
2144 }
2145
2146 /* Put a 0-length skb in the receive queue as an error indication */
2147 void
ppp_input_error(struct ppp_channel * chan,int code)2148 ppp_input_error(struct ppp_channel *chan, int code)
2149 {
2150 struct channel *pch = chan->ppp;
2151 struct sk_buff *skb;
2152
2153 if (!pch)
2154 return;
2155
2156 read_lock_bh(&pch->upl);
2157 if (pch->ppp) {
2158 skb = alloc_skb(0, GFP_ATOMIC);
2159 if (skb) {
2160 skb->len = 0; /* probably unnecessary */
2161 skb->cb[0] = code;
2162 ppp_do_recv(pch->ppp, skb, pch);
2163 }
2164 }
2165 read_unlock_bh(&pch->upl);
2166 }
2167
2168 /*
2169 * We come in here to process a received frame.
2170 * The receive side of the ppp unit is locked.
2171 */
2172 static void
ppp_receive_frame(struct ppp * ppp,struct sk_buff * skb,struct channel * pch)2173 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
2174 {
2175 /* note: a 0-length skb is used as an error indication */
2176 if (skb->len > 0) {
2177 skb_checksum_complete_unset(skb);
2178 #ifdef CONFIG_PPP_MULTILINK
2179 /* XXX do channel-level decompression here */
2180 if (PPP_PROTO(skb) == PPP_MP)
2181 ppp_receive_mp_frame(ppp, skb, pch);
2182 else
2183 #endif /* CONFIG_PPP_MULTILINK */
2184 ppp_receive_nonmp_frame(ppp, skb);
2185 } else {
2186 kfree_skb(skb);
2187 ppp_receive_error(ppp);
2188 }
2189 }
2190
2191 static void
ppp_receive_error(struct ppp * ppp)2192 ppp_receive_error(struct ppp *ppp)
2193 {
2194 ++ppp->dev->stats.rx_errors;
2195 if (ppp->vj)
2196 slhc_toss(ppp->vj);
2197 }
2198
2199 static void
ppp_receive_nonmp_frame(struct ppp * ppp,struct sk_buff * skb)2200 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
2201 {
2202 struct sk_buff *ns;
2203 int proto, len, npi;
2204
2205 /*
2206 * Decompress the frame, if compressed.
2207 * Note that some decompressors need to see uncompressed frames
2208 * that come in as well as compressed frames.
2209 */
2210 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) &&
2211 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
2212 skb = ppp_decompress_frame(ppp, skb);
2213
2214 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
2215 goto err;
2216
2217 /* At this point the "Protocol" field MUST be decompressed, either in
2218 * ppp_input(), ppp_decompress_frame() or in ppp_receive_mp_frame().
2219 */
2220 proto = PPP_PROTO(skb);
2221 switch (proto) {
2222 case PPP_VJC_COMP:
2223 /* decompress VJ compressed packets */
2224 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
2225 goto err;
2226
2227 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
2228 /* copy to a new sk_buff with more tailroom */
2229 ns = dev_alloc_skb(skb->len + 128);
2230 if (!ns) {
2231 netdev_err(ppp->dev, "PPP: no memory "
2232 "(VJ decomp)\n");
2233 goto err;
2234 }
2235 skb_reserve(ns, 2);
2236 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
2237 consume_skb(skb);
2238 skb = ns;
2239 }
2240 else
2241 skb->ip_summed = CHECKSUM_NONE;
2242
2243 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
2244 if (len <= 0) {
2245 netdev_printk(KERN_DEBUG, ppp->dev,
2246 "PPP: VJ decompression error\n");
2247 goto err;
2248 }
2249 len += 2;
2250 if (len > skb->len)
2251 skb_put(skb, len - skb->len);
2252 else if (len < skb->len)
2253 skb_trim(skb, len);
2254 proto = PPP_IP;
2255 break;
2256
2257 case PPP_VJC_UNCOMP:
2258 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
2259 goto err;
2260
2261 /* Until we fix the decompressor need to make sure
2262 * data portion is linear.
2263 */
2264 if (!pskb_may_pull(skb, skb->len))
2265 goto err;
2266
2267 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
2268 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n");
2269 goto err;
2270 }
2271 proto = PPP_IP;
2272 break;
2273
2274 case PPP_CCP:
2275 ppp_ccp_peek(ppp, skb, 1);
2276 break;
2277 }
2278
2279 ++ppp->stats64.rx_packets;
2280 ppp->stats64.rx_bytes += skb->len - 2;
2281
2282 npi = proto_to_npindex(proto);
2283 if (npi < 0) {
2284 /* control or unknown frame - pass it to pppd */
2285 skb_queue_tail(&ppp->file.rq, skb);
2286 /* limit queue length by dropping old frames */
2287 while (ppp->file.rq.qlen > PPP_MAX_RQLEN &&
2288 (skb = skb_dequeue(&ppp->file.rq)))
2289 kfree_skb(skb);
2290 /* wake up any process polling or blocking on read */
2291 wake_up_interruptible(&ppp->file.rwait);
2292
2293 } else {
2294 /* network protocol frame - give it to the kernel */
2295
2296 #ifdef CONFIG_PPP_FILTER
2297 /* check if the packet passes the pass and active filters */
2298 /* the filter instructions are constructed assuming
2299 a four-byte PPP header on each packet */
2300 if (ppp->pass_filter || ppp->active_filter) {
2301 if (skb_unclone(skb, GFP_ATOMIC))
2302 goto err;
2303
2304 *(u8 *)skb_push(skb, 2) = 0;
2305 if (ppp->pass_filter &&
2306 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
2307 if (ppp->debug & 1)
2308 netdev_printk(KERN_DEBUG, ppp->dev,
2309 "PPP: inbound frame "
2310 "not passed\n");
2311 kfree_skb(skb);
2312 return;
2313 }
2314 if (!(ppp->active_filter &&
2315 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
2316 ppp->last_recv = jiffies;
2317 __skb_pull(skb, 2);
2318 } else
2319 #endif /* CONFIG_PPP_FILTER */
2320 ppp->last_recv = jiffies;
2321
2322 if ((ppp->dev->flags & IFF_UP) == 0 ||
2323 ppp->npmode[npi] != NPMODE_PASS) {
2324 kfree_skb(skb);
2325 } else {
2326 /* chop off protocol */
2327 skb_pull_rcsum(skb, 2);
2328 skb->dev = ppp->dev;
2329 skb->protocol = htons(npindex_to_ethertype[npi]);
2330 skb_reset_mac_header(skb);
2331 skb_scrub_packet(skb, !net_eq(ppp->ppp_net,
2332 dev_net(ppp->dev)));
2333 netif_rx(skb);
2334 }
2335 }
2336 return;
2337
2338 err:
2339 kfree_skb(skb);
2340 ppp_receive_error(ppp);
2341 }
2342
2343 static struct sk_buff *
ppp_decompress_frame(struct ppp * ppp,struct sk_buff * skb)2344 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
2345 {
2346 int proto = PPP_PROTO(skb);
2347 struct sk_buff *ns;
2348 int len;
2349
2350 /* Until we fix all the decompressor's need to make sure
2351 * data portion is linear.
2352 */
2353 if (!pskb_may_pull(skb, skb->len))
2354 goto err;
2355
2356 if (proto == PPP_COMP) {
2357 int obuff_size;
2358
2359 switch(ppp->rcomp->compress_proto) {
2360 case CI_MPPE:
2361 obuff_size = ppp->mru + PPP_HDRLEN + 1;
2362 break;
2363 default:
2364 obuff_size = ppp->mru + PPP_HDRLEN;
2365 break;
2366 }
2367
2368 ns = dev_alloc_skb(obuff_size);
2369 if (!ns) {
2370 netdev_err(ppp->dev, "ppp_decompress_frame: "
2371 "no memory\n");
2372 goto err;
2373 }
2374 /* the decompressor still expects the A/C bytes in the hdr */
2375 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
2376 skb->len + 2, ns->data, obuff_size);
2377 if (len < 0) {
2378 /* Pass the compressed frame to pppd as an
2379 error indication. */
2380 if (len == DECOMP_FATALERROR)
2381 ppp->rstate |= SC_DC_FERROR;
2382 kfree_skb(ns);
2383 goto err;
2384 }
2385
2386 consume_skb(skb);
2387 skb = ns;
2388 skb_put(skb, len);
2389 skb_pull(skb, 2); /* pull off the A/C bytes */
2390
2391 /* Don't call __ppp_decompress_proto() here, but instead rely on
2392 * corresponding algo (mppe/bsd/deflate) to decompress it.
2393 */
2394 } else {
2395 /* Uncompressed frame - pass to decompressor so it
2396 can update its dictionary if necessary. */
2397 if (ppp->rcomp->incomp)
2398 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
2399 skb->len + 2);
2400 }
2401
2402 return skb;
2403
2404 err:
2405 ppp->rstate |= SC_DC_ERROR;
2406 ppp_receive_error(ppp);
2407 return skb;
2408 }
2409
2410 #ifdef CONFIG_PPP_MULTILINK
2411 /*
2412 * Receive a multilink frame.
2413 * We put it on the reconstruction queue and then pull off
2414 * as many completed frames as we can.
2415 */
2416 static void
ppp_receive_mp_frame(struct ppp * ppp,struct sk_buff * skb,struct channel * pch)2417 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
2418 {
2419 u32 mask, seq;
2420 struct channel *ch;
2421 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
2422
2423 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
2424 goto err; /* no good, throw it away */
2425
2426 /* Decode sequence number and begin/end bits */
2427 if (ppp->flags & SC_MP_SHORTSEQ) {
2428 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
2429 mask = 0xfff;
2430 } else {
2431 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
2432 mask = 0xffffff;
2433 }
2434 PPP_MP_CB(skb)->BEbits = skb->data[2];
2435 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
2436
2437 /*
2438 * Do protocol ID decompression on the first fragment of each packet.
2439 * We have to do that here, because ppp_receive_nonmp_frame() expects
2440 * decompressed protocol field.
2441 */
2442 if (PPP_MP_CB(skb)->BEbits & B)
2443 __ppp_decompress_proto(skb);
2444
2445 /*
2446 * Expand sequence number to 32 bits, making it as close
2447 * as possible to ppp->minseq.
2448 */
2449 seq |= ppp->minseq & ~mask;
2450 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
2451 seq += mask + 1;
2452 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
2453 seq -= mask + 1; /* should never happen */
2454 PPP_MP_CB(skb)->sequence = seq;
2455 pch->lastseq = seq;
2456
2457 /*
2458 * If this packet comes before the next one we were expecting,
2459 * drop it.
2460 */
2461 if (seq_before(seq, ppp->nextseq)) {
2462 kfree_skb(skb);
2463 ++ppp->dev->stats.rx_dropped;
2464 ppp_receive_error(ppp);
2465 return;
2466 }
2467
2468 /*
2469 * Reevaluate minseq, the minimum over all channels of the
2470 * last sequence number received on each channel. Because of
2471 * the increasing sequence number rule, we know that any fragment
2472 * before `minseq' which hasn't arrived is never going to arrive.
2473 * The list of channels can't change because we have the receive
2474 * side of the ppp unit locked.
2475 */
2476 list_for_each_entry(ch, &ppp->channels, clist) {
2477 if (seq_before(ch->lastseq, seq))
2478 seq = ch->lastseq;
2479 }
2480 if (seq_before(ppp->minseq, seq))
2481 ppp->minseq = seq;
2482
2483 /* Put the fragment on the reconstruction queue */
2484 ppp_mp_insert(ppp, skb);
2485
2486 /* If the queue is getting long, don't wait any longer for packets
2487 before the start of the queue. */
2488 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
2489 struct sk_buff *mskb = skb_peek(&ppp->mrq);
2490 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence))
2491 ppp->minseq = PPP_MP_CB(mskb)->sequence;
2492 }
2493
2494 /* Pull completed packets off the queue and receive them. */
2495 while ((skb = ppp_mp_reconstruct(ppp))) {
2496 if (pskb_may_pull(skb, 2))
2497 ppp_receive_nonmp_frame(ppp, skb);
2498 else {
2499 ++ppp->dev->stats.rx_length_errors;
2500 kfree_skb(skb);
2501 ppp_receive_error(ppp);
2502 }
2503 }
2504
2505 return;
2506
2507 err:
2508 kfree_skb(skb);
2509 ppp_receive_error(ppp);
2510 }
2511
2512 /*
2513 * Insert a fragment on the MP reconstruction queue.
2514 * The queue is ordered by increasing sequence number.
2515 */
2516 static void
ppp_mp_insert(struct ppp * ppp,struct sk_buff * skb)2517 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
2518 {
2519 struct sk_buff *p;
2520 struct sk_buff_head *list = &ppp->mrq;
2521 u32 seq = PPP_MP_CB(skb)->sequence;
2522
2523 /* N.B. we don't need to lock the list lock because we have the
2524 ppp unit receive-side lock. */
2525 skb_queue_walk(list, p) {
2526 if (seq_before(seq, PPP_MP_CB(p)->sequence))
2527 break;
2528 }
2529 __skb_queue_before(list, p, skb);
2530 }
2531
2532 /*
2533 * Reconstruct a packet from the MP fragment queue.
2534 * We go through increasing sequence numbers until we find a
2535 * complete packet, or we get to the sequence number for a fragment
2536 * which hasn't arrived but might still do so.
2537 */
2538 static struct sk_buff *
ppp_mp_reconstruct(struct ppp * ppp)2539 ppp_mp_reconstruct(struct ppp *ppp)
2540 {
2541 u32 seq = ppp->nextseq;
2542 u32 minseq = ppp->minseq;
2543 struct sk_buff_head *list = &ppp->mrq;
2544 struct sk_buff *p, *tmp;
2545 struct sk_buff *head, *tail;
2546 struct sk_buff *skb = NULL;
2547 int lost = 0, len = 0;
2548
2549 if (ppp->mrru == 0) /* do nothing until mrru is set */
2550 return NULL;
2551 head = __skb_peek(list);
2552 tail = NULL;
2553 skb_queue_walk_safe(list, p, tmp) {
2554 again:
2555 if (seq_before(PPP_MP_CB(p)->sequence, seq)) {
2556 /* this can't happen, anyway ignore the skb */
2557 netdev_err(ppp->dev, "ppp_mp_reconstruct bad "
2558 "seq %u < %u\n",
2559 PPP_MP_CB(p)->sequence, seq);
2560 __skb_unlink(p, list);
2561 kfree_skb(p);
2562 continue;
2563 }
2564 if (PPP_MP_CB(p)->sequence != seq) {
2565 u32 oldseq;
2566 /* Fragment `seq' is missing. If it is after
2567 minseq, it might arrive later, so stop here. */
2568 if (seq_after(seq, minseq))
2569 break;
2570 /* Fragment `seq' is lost, keep going. */
2571 lost = 1;
2572 oldseq = seq;
2573 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)?
2574 minseq + 1: PPP_MP_CB(p)->sequence;
2575
2576 if (ppp->debug & 1)
2577 netdev_printk(KERN_DEBUG, ppp->dev,
2578 "lost frag %u..%u\n",
2579 oldseq, seq-1);
2580
2581 goto again;
2582 }
2583
2584 /*
2585 * At this point we know that all the fragments from
2586 * ppp->nextseq to seq are either present or lost.
2587 * Also, there are no complete packets in the queue
2588 * that have no missing fragments and end before this
2589 * fragment.
2590 */
2591
2592 /* B bit set indicates this fragment starts a packet */
2593 if (PPP_MP_CB(p)->BEbits & B) {
2594 head = p;
2595 lost = 0;
2596 len = 0;
2597 }
2598
2599 len += p->len;
2600
2601 /* Got a complete packet yet? */
2602 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) &&
2603 (PPP_MP_CB(head)->BEbits & B)) {
2604 if (len > ppp->mrru + 2) {
2605 ++ppp->dev->stats.rx_length_errors;
2606 netdev_printk(KERN_DEBUG, ppp->dev,
2607 "PPP: reconstructed packet"
2608 " is too long (%d)\n", len);
2609 } else {
2610 tail = p;
2611 break;
2612 }
2613 ppp->nextseq = seq + 1;
2614 }
2615
2616 /*
2617 * If this is the ending fragment of a packet,
2618 * and we haven't found a complete valid packet yet,
2619 * we can discard up to and including this fragment.
2620 */
2621 if (PPP_MP_CB(p)->BEbits & E) {
2622 struct sk_buff *tmp2;
2623
2624 skb_queue_reverse_walk_from_safe(list, p, tmp2) {
2625 if (ppp->debug & 1)
2626 netdev_printk(KERN_DEBUG, ppp->dev,
2627 "discarding frag %u\n",
2628 PPP_MP_CB(p)->sequence);
2629 __skb_unlink(p, list);
2630 kfree_skb(p);
2631 }
2632 head = skb_peek(list);
2633 if (!head)
2634 break;
2635 }
2636 ++seq;
2637 }
2638
2639 /* If we have a complete packet, copy it all into one skb. */
2640 if (tail != NULL) {
2641 /* If we have discarded any fragments,
2642 signal a receive error. */
2643 if (PPP_MP_CB(head)->sequence != ppp->nextseq) {
2644 skb_queue_walk_safe(list, p, tmp) {
2645 if (p == head)
2646 break;
2647 if (ppp->debug & 1)
2648 netdev_printk(KERN_DEBUG, ppp->dev,
2649 "discarding frag %u\n",
2650 PPP_MP_CB(p)->sequence);
2651 __skb_unlink(p, list);
2652 kfree_skb(p);
2653 }
2654
2655 if (ppp->debug & 1)
2656 netdev_printk(KERN_DEBUG, ppp->dev,
2657 " missed pkts %u..%u\n",
2658 ppp->nextseq,
2659 PPP_MP_CB(head)->sequence-1);
2660 ++ppp->dev->stats.rx_dropped;
2661 ppp_receive_error(ppp);
2662 }
2663
2664 skb = head;
2665 if (head != tail) {
2666 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list;
2667 p = skb_queue_next(list, head);
2668 __skb_unlink(skb, list);
2669 skb_queue_walk_from_safe(list, p, tmp) {
2670 __skb_unlink(p, list);
2671 *fragpp = p;
2672 p->next = NULL;
2673 fragpp = &p->next;
2674
2675 skb->len += p->len;
2676 skb->data_len += p->len;
2677 skb->truesize += p->truesize;
2678
2679 if (p == tail)
2680 break;
2681 }
2682 } else {
2683 __skb_unlink(skb, list);
2684 }
2685
2686 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1;
2687 }
2688
2689 return skb;
2690 }
2691 #endif /* CONFIG_PPP_MULTILINK */
2692
2693 /*
2694 * Channel interface.
2695 */
2696
2697 /* Create a new, unattached ppp channel. */
ppp_register_channel(struct ppp_channel * chan)2698 int ppp_register_channel(struct ppp_channel *chan)
2699 {
2700 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2701 }
2702
2703 /* Create a new, unattached ppp channel for specified net. */
ppp_register_net_channel(struct net * net,struct ppp_channel * chan)2704 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
2705 {
2706 struct channel *pch;
2707 struct ppp_net *pn;
2708
2709 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2710 if (!pch)
2711 return -ENOMEM;
2712
2713 pn = ppp_pernet(net);
2714
2715 pch->ppp = NULL;
2716 pch->chan = chan;
2717 pch->chan_net = get_net(net);
2718 chan->ppp = pch;
2719 init_ppp_file(&pch->file, CHANNEL);
2720 pch->file.hdrlen = chan->hdrlen;
2721 #ifdef CONFIG_PPP_MULTILINK
2722 pch->lastseq = -1;
2723 #endif /* CONFIG_PPP_MULTILINK */
2724 init_rwsem(&pch->chan_sem);
2725 spin_lock_init(&pch->downl);
2726 rwlock_init(&pch->upl);
2727
2728 spin_lock_bh(&pn->all_channels_lock);
2729 pch->file.index = ++pn->last_channel_index;
2730 list_add(&pch->list, &pn->new_channels);
2731 atomic_inc(&channel_count);
2732 spin_unlock_bh(&pn->all_channels_lock);
2733
2734 return 0;
2735 }
2736
2737 /*
2738 * Return the index of a channel.
2739 */
ppp_channel_index(struct ppp_channel * chan)2740 int ppp_channel_index(struct ppp_channel *chan)
2741 {
2742 struct channel *pch = chan->ppp;
2743
2744 if (pch)
2745 return pch->file.index;
2746 return -1;
2747 }
2748
2749 /*
2750 * Return the PPP unit number to which a channel is connected.
2751 */
ppp_unit_number(struct ppp_channel * chan)2752 int ppp_unit_number(struct ppp_channel *chan)
2753 {
2754 struct channel *pch = chan->ppp;
2755 int unit = -1;
2756
2757 if (pch) {
2758 read_lock_bh(&pch->upl);
2759 if (pch->ppp)
2760 unit = pch->ppp->file.index;
2761 read_unlock_bh(&pch->upl);
2762 }
2763 return unit;
2764 }
2765
2766 /*
2767 * Return the PPP device interface name of a channel.
2768 */
ppp_dev_name(struct ppp_channel * chan)2769 char *ppp_dev_name(struct ppp_channel *chan)
2770 {
2771 struct channel *pch = chan->ppp;
2772 char *name = NULL;
2773
2774 if (pch) {
2775 read_lock_bh(&pch->upl);
2776 if (pch->ppp && pch->ppp->dev)
2777 name = pch->ppp->dev->name;
2778 read_unlock_bh(&pch->upl);
2779 }
2780 return name;
2781 }
2782
2783
2784 /*
2785 * Disconnect a channel from the generic layer.
2786 * This must be called in process context.
2787 */
2788 void
ppp_unregister_channel(struct ppp_channel * chan)2789 ppp_unregister_channel(struct ppp_channel *chan)
2790 {
2791 struct channel *pch = chan->ppp;
2792 struct ppp_net *pn;
2793
2794 if (!pch)
2795 return; /* should never happen */
2796
2797 chan->ppp = NULL;
2798
2799 /*
2800 * This ensures that we have returned from any calls into the
2801 * the channel's start_xmit or ioctl routine before we proceed.
2802 */
2803 down_write(&pch->chan_sem);
2804 spin_lock_bh(&pch->downl);
2805 pch->chan = NULL;
2806 spin_unlock_bh(&pch->downl);
2807 up_write(&pch->chan_sem);
2808 ppp_disconnect_channel(pch);
2809
2810 pn = ppp_pernet(pch->chan_net);
2811 spin_lock_bh(&pn->all_channels_lock);
2812 list_del(&pch->list);
2813 spin_unlock_bh(&pn->all_channels_lock);
2814
2815 pch->file.dead = 1;
2816 wake_up_interruptible(&pch->file.rwait);
2817 if (refcount_dec_and_test(&pch->file.refcnt))
2818 ppp_destroy_channel(pch);
2819 }
2820
2821 /*
2822 * Callback from a channel when it can accept more to transmit.
2823 * This should be called at BH/softirq level, not interrupt level.
2824 */
2825 void
ppp_output_wakeup(struct ppp_channel * chan)2826 ppp_output_wakeup(struct ppp_channel *chan)
2827 {
2828 struct channel *pch = chan->ppp;
2829
2830 if (!pch)
2831 return;
2832 ppp_channel_push(pch);
2833 }
2834
2835 /*
2836 * Compression control.
2837 */
2838
2839 /* Process the PPPIOCSCOMPRESS ioctl. */
2840 static int
ppp_set_compress(struct ppp * ppp,struct ppp_option_data * data)2841 ppp_set_compress(struct ppp *ppp, struct ppp_option_data *data)
2842 {
2843 int err = -EFAULT;
2844 struct compressor *cp, *ocomp;
2845 void *state, *ostate;
2846 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2847
2848 if (data->length > CCP_MAX_OPTION_LENGTH)
2849 goto out;
2850 if (copy_from_user(ccp_option, data->ptr, data->length))
2851 goto out;
2852
2853 err = -EINVAL;
2854 if (data->length < 2 || ccp_option[1] < 2 || ccp_option[1] > data->length)
2855 goto out;
2856
2857 cp = try_then_request_module(
2858 find_compressor(ccp_option[0]),
2859 "ppp-compress-%d", ccp_option[0]);
2860 if (!cp)
2861 goto out;
2862
2863 err = -ENOBUFS;
2864 if (data->transmit) {
2865 state = cp->comp_alloc(ccp_option, data->length);
2866 if (state) {
2867 ppp_xmit_lock(ppp);
2868 ppp->xstate &= ~SC_COMP_RUN;
2869 ocomp = ppp->xcomp;
2870 ostate = ppp->xc_state;
2871 ppp->xcomp = cp;
2872 ppp->xc_state = state;
2873 ppp_xmit_unlock(ppp);
2874 if (ostate) {
2875 ocomp->comp_free(ostate);
2876 module_put(ocomp->owner);
2877 }
2878 err = 0;
2879 } else
2880 module_put(cp->owner);
2881
2882 } else {
2883 state = cp->decomp_alloc(ccp_option, data->length);
2884 if (state) {
2885 ppp_recv_lock(ppp);
2886 ppp->rstate &= ~SC_DECOMP_RUN;
2887 ocomp = ppp->rcomp;
2888 ostate = ppp->rc_state;
2889 ppp->rcomp = cp;
2890 ppp->rc_state = state;
2891 ppp_recv_unlock(ppp);
2892 if (ostate) {
2893 ocomp->decomp_free(ostate);
2894 module_put(ocomp->owner);
2895 }
2896 err = 0;
2897 } else
2898 module_put(cp->owner);
2899 }
2900
2901 out:
2902 return err;
2903 }
2904
2905 /*
2906 * Look at a CCP packet and update our state accordingly.
2907 * We assume the caller has the xmit or recv path locked.
2908 */
2909 static void
ppp_ccp_peek(struct ppp * ppp,struct sk_buff * skb,int inbound)2910 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2911 {
2912 unsigned char *dp;
2913 int len;
2914
2915 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2916 return; /* no header */
2917 dp = skb->data + 2;
2918
2919 switch (CCP_CODE(dp)) {
2920 case CCP_CONFREQ:
2921
2922 /* A ConfReq starts negotiation of compression
2923 * in one direction of transmission,
2924 * and hence brings it down...but which way?
2925 *
2926 * Remember:
2927 * A ConfReq indicates what the sender would like to receive
2928 */
2929 if(inbound)
2930 /* He is proposing what I should send */
2931 ppp->xstate &= ~SC_COMP_RUN;
2932 else
2933 /* I am proposing to what he should send */
2934 ppp->rstate &= ~SC_DECOMP_RUN;
2935
2936 break;
2937
2938 case CCP_TERMREQ:
2939 case CCP_TERMACK:
2940 /*
2941 * CCP is going down, both directions of transmission
2942 */
2943 ppp->rstate &= ~SC_DECOMP_RUN;
2944 ppp->xstate &= ~SC_COMP_RUN;
2945 break;
2946
2947 case CCP_CONFACK:
2948 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2949 break;
2950 len = CCP_LENGTH(dp);
2951 if (!pskb_may_pull(skb, len + 2))
2952 return; /* too short */
2953 dp += CCP_HDRLEN;
2954 len -= CCP_HDRLEN;
2955 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2956 break;
2957 if (inbound) {
2958 /* we will start receiving compressed packets */
2959 if (!ppp->rc_state)
2960 break;
2961 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2962 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2963 ppp->rstate |= SC_DECOMP_RUN;
2964 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2965 }
2966 } else {
2967 /* we will soon start sending compressed packets */
2968 if (!ppp->xc_state)
2969 break;
2970 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2971 ppp->file.index, 0, ppp->debug))
2972 ppp->xstate |= SC_COMP_RUN;
2973 }
2974 break;
2975
2976 case CCP_RESETACK:
2977 /* reset the [de]compressor */
2978 if ((ppp->flags & SC_CCP_UP) == 0)
2979 break;
2980 if (inbound) {
2981 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2982 ppp->rcomp->decomp_reset(ppp->rc_state);
2983 ppp->rstate &= ~SC_DC_ERROR;
2984 }
2985 } else {
2986 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2987 ppp->xcomp->comp_reset(ppp->xc_state);
2988 }
2989 break;
2990 }
2991 }
2992
2993 /* Free up compression resources. */
2994 static void
ppp_ccp_closed(struct ppp * ppp)2995 ppp_ccp_closed(struct ppp *ppp)
2996 {
2997 void *xstate, *rstate;
2998 struct compressor *xcomp, *rcomp;
2999
3000 ppp_lock(ppp);
3001 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
3002 ppp->xstate = 0;
3003 xcomp = ppp->xcomp;
3004 xstate = ppp->xc_state;
3005 ppp->xc_state = NULL;
3006 ppp->rstate = 0;
3007 rcomp = ppp->rcomp;
3008 rstate = ppp->rc_state;
3009 ppp->rc_state = NULL;
3010 ppp_unlock(ppp);
3011
3012 if (xstate) {
3013 xcomp->comp_free(xstate);
3014 module_put(xcomp->owner);
3015 }
3016 if (rstate) {
3017 rcomp->decomp_free(rstate);
3018 module_put(rcomp->owner);
3019 }
3020 }
3021
3022 /* List of compressors. */
3023 static LIST_HEAD(compressor_list);
3024 static DEFINE_SPINLOCK(compressor_list_lock);
3025
3026 struct compressor_entry {
3027 struct list_head list;
3028 struct compressor *comp;
3029 };
3030
3031 static struct compressor_entry *
find_comp_entry(int proto)3032 find_comp_entry(int proto)
3033 {
3034 struct compressor_entry *ce;
3035
3036 list_for_each_entry(ce, &compressor_list, list) {
3037 if (ce->comp->compress_proto == proto)
3038 return ce;
3039 }
3040 return NULL;
3041 }
3042
3043 /* Register a compressor */
3044 int
ppp_register_compressor(struct compressor * cp)3045 ppp_register_compressor(struct compressor *cp)
3046 {
3047 struct compressor_entry *ce;
3048 int ret;
3049 spin_lock(&compressor_list_lock);
3050 ret = -EEXIST;
3051 if (find_comp_entry(cp->compress_proto))
3052 goto out;
3053 ret = -ENOMEM;
3054 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
3055 if (!ce)
3056 goto out;
3057 ret = 0;
3058 ce->comp = cp;
3059 list_add(&ce->list, &compressor_list);
3060 out:
3061 spin_unlock(&compressor_list_lock);
3062 return ret;
3063 }
3064
3065 /* Unregister a compressor */
3066 void
ppp_unregister_compressor(struct compressor * cp)3067 ppp_unregister_compressor(struct compressor *cp)
3068 {
3069 struct compressor_entry *ce;
3070
3071 spin_lock(&compressor_list_lock);
3072 ce = find_comp_entry(cp->compress_proto);
3073 if (ce && ce->comp == cp) {
3074 list_del(&ce->list);
3075 kfree(ce);
3076 }
3077 spin_unlock(&compressor_list_lock);
3078 }
3079
3080 /* Find a compressor. */
3081 static struct compressor *
find_compressor(int type)3082 find_compressor(int type)
3083 {
3084 struct compressor_entry *ce;
3085 struct compressor *cp = NULL;
3086
3087 spin_lock(&compressor_list_lock);
3088 ce = find_comp_entry(type);
3089 if (ce) {
3090 cp = ce->comp;
3091 if (!try_module_get(cp->owner))
3092 cp = NULL;
3093 }
3094 spin_unlock(&compressor_list_lock);
3095 return cp;
3096 }
3097
3098 /*
3099 * Miscelleneous stuff.
3100 */
3101
3102 static void
ppp_get_stats(struct ppp * ppp,struct ppp_stats * st)3103 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
3104 {
3105 struct slcompress *vj = ppp->vj;
3106
3107 memset(st, 0, sizeof(*st));
3108 st->p.ppp_ipackets = ppp->stats64.rx_packets;
3109 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
3110 st->p.ppp_ibytes = ppp->stats64.rx_bytes;
3111 st->p.ppp_opackets = ppp->stats64.tx_packets;
3112 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
3113 st->p.ppp_obytes = ppp->stats64.tx_bytes;
3114 if (!vj)
3115 return;
3116 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
3117 st->vj.vjs_compressed = vj->sls_o_compressed;
3118 st->vj.vjs_searches = vj->sls_o_searches;
3119 st->vj.vjs_misses = vj->sls_o_misses;
3120 st->vj.vjs_errorin = vj->sls_i_error;
3121 st->vj.vjs_tossed = vj->sls_i_tossed;
3122 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
3123 st->vj.vjs_compressedin = vj->sls_i_compressed;
3124 }
3125
3126 /*
3127 * Stuff for handling the lists of ppp units and channels
3128 * and for initialization.
3129 */
3130
3131 /*
3132 * Create a new ppp interface unit. Fails if it can't allocate memory
3133 * or if there is already a unit with the requested number.
3134 * unit == -1 means allocate a new number.
3135 */
ppp_create_interface(struct net * net,struct file * file,int * unit)3136 static int ppp_create_interface(struct net *net, struct file *file, int *unit)
3137 {
3138 struct ppp_config conf = {
3139 .file = file,
3140 .unit = *unit,
3141 .ifname_is_set = false,
3142 };
3143 struct net_device *dev;
3144 struct ppp *ppp;
3145 int err;
3146
3147 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_ENUM, ppp_setup);
3148 if (!dev) {
3149 err = -ENOMEM;
3150 goto err;
3151 }
3152 dev_net_set(dev, net);
3153 dev->rtnl_link_ops = &ppp_link_ops;
3154
3155 rtnl_lock();
3156
3157 err = ppp_dev_configure(net, dev, &conf);
3158 if (err < 0)
3159 goto err_dev;
3160 ppp = netdev_priv(dev);
3161 *unit = ppp->file.index;
3162
3163 rtnl_unlock();
3164
3165 return 0;
3166
3167 err_dev:
3168 rtnl_unlock();
3169 free_netdev(dev);
3170 err:
3171 return err;
3172 }
3173
3174 /*
3175 * Initialize a ppp_file structure.
3176 */
3177 static void
init_ppp_file(struct ppp_file * pf,int kind)3178 init_ppp_file(struct ppp_file *pf, int kind)
3179 {
3180 pf->kind = kind;
3181 skb_queue_head_init(&pf->xq);
3182 skb_queue_head_init(&pf->rq);
3183 refcount_set(&pf->refcnt, 1);
3184 init_waitqueue_head(&pf->rwait);
3185 }
3186
3187 /*
3188 * Free the memory used by a ppp unit. This is only called once
3189 * there are no channels connected to the unit and no file structs
3190 * that reference the unit.
3191 */
ppp_destroy_interface(struct ppp * ppp)3192 static void ppp_destroy_interface(struct ppp *ppp)
3193 {
3194 atomic_dec(&ppp_unit_count);
3195
3196 if (!ppp->file.dead || ppp->n_channels) {
3197 /* "can't happen" */
3198 netdev_err(ppp->dev, "ppp: destroying ppp struct %p "
3199 "but dead=%d n_channels=%d !\n",
3200 ppp, ppp->file.dead, ppp->n_channels);
3201 return;
3202 }
3203
3204 ppp_ccp_closed(ppp);
3205 if (ppp->vj) {
3206 slhc_free(ppp->vj);
3207 ppp->vj = NULL;
3208 }
3209 skb_queue_purge(&ppp->file.xq);
3210 skb_queue_purge(&ppp->file.rq);
3211 #ifdef CONFIG_PPP_MULTILINK
3212 skb_queue_purge(&ppp->mrq);
3213 #endif /* CONFIG_PPP_MULTILINK */
3214 #ifdef CONFIG_PPP_FILTER
3215 if (ppp->pass_filter) {
3216 bpf_prog_destroy(ppp->pass_filter);
3217 ppp->pass_filter = NULL;
3218 }
3219
3220 if (ppp->active_filter) {
3221 bpf_prog_destroy(ppp->active_filter);
3222 ppp->active_filter = NULL;
3223 }
3224 #endif /* CONFIG_PPP_FILTER */
3225
3226 kfree_skb(ppp->xmit_pending);
3227 free_percpu(ppp->xmit_recursion);
3228
3229 free_netdev(ppp->dev);
3230 }
3231
3232 /*
3233 * Locate an existing ppp unit.
3234 * The caller should have locked the all_ppp_mutex.
3235 */
3236 static struct ppp *
ppp_find_unit(struct ppp_net * pn,int unit)3237 ppp_find_unit(struct ppp_net *pn, int unit)
3238 {
3239 return unit_find(&pn->units_idr, unit);
3240 }
3241
3242 /*
3243 * Locate an existing ppp channel.
3244 * The caller should have locked the all_channels_lock.
3245 * First we look in the new_channels list, then in the
3246 * all_channels list. If found in the new_channels list,
3247 * we move it to the all_channels list. This is for speed
3248 * when we have a lot of channels in use.
3249 */
3250 static struct channel *
ppp_find_channel(struct ppp_net * pn,int unit)3251 ppp_find_channel(struct ppp_net *pn, int unit)
3252 {
3253 struct channel *pch;
3254
3255 list_for_each_entry(pch, &pn->new_channels, list) {
3256 if (pch->file.index == unit) {
3257 list_move(&pch->list, &pn->all_channels);
3258 return pch;
3259 }
3260 }
3261
3262 list_for_each_entry(pch, &pn->all_channels, list) {
3263 if (pch->file.index == unit)
3264 return pch;
3265 }
3266
3267 return NULL;
3268 }
3269
3270 /*
3271 * Connect a PPP channel to a PPP interface unit.
3272 */
3273 static int
ppp_connect_channel(struct channel * pch,int unit)3274 ppp_connect_channel(struct channel *pch, int unit)
3275 {
3276 struct ppp *ppp;
3277 struct ppp_net *pn;
3278 int ret = -ENXIO;
3279 int hdrlen;
3280
3281 pn = ppp_pernet(pch->chan_net);
3282
3283 mutex_lock(&pn->all_ppp_mutex);
3284 ppp = ppp_find_unit(pn, unit);
3285 if (!ppp)
3286 goto out;
3287 write_lock_bh(&pch->upl);
3288 ret = -EINVAL;
3289 if (pch->ppp)
3290 goto outl;
3291
3292 ppp_lock(ppp);
3293 spin_lock_bh(&pch->downl);
3294 if (!pch->chan) {
3295 /* Don't connect unregistered channels */
3296 spin_unlock_bh(&pch->downl);
3297 ppp_unlock(ppp);
3298 ret = -ENOTCONN;
3299 goto outl;
3300 }
3301 spin_unlock_bh(&pch->downl);
3302 if (pch->file.hdrlen > ppp->file.hdrlen)
3303 ppp->file.hdrlen = pch->file.hdrlen;
3304 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
3305 if (hdrlen > ppp->dev->hard_header_len)
3306 ppp->dev->hard_header_len = hdrlen;
3307 list_add_tail(&pch->clist, &ppp->channels);
3308 ++ppp->n_channels;
3309 pch->ppp = ppp;
3310 refcount_inc(&ppp->file.refcnt);
3311 ppp_unlock(ppp);
3312 ret = 0;
3313
3314 outl:
3315 write_unlock_bh(&pch->upl);
3316 out:
3317 mutex_unlock(&pn->all_ppp_mutex);
3318 return ret;
3319 }
3320
3321 /*
3322 * Disconnect a channel from its ppp unit.
3323 */
3324 static int
ppp_disconnect_channel(struct channel * pch)3325 ppp_disconnect_channel(struct channel *pch)
3326 {
3327 struct ppp *ppp;
3328 int err = -EINVAL;
3329
3330 write_lock_bh(&pch->upl);
3331 ppp = pch->ppp;
3332 pch->ppp = NULL;
3333 write_unlock_bh(&pch->upl);
3334 if (ppp) {
3335 /* remove it from the ppp unit's list */
3336 ppp_lock(ppp);
3337 list_del(&pch->clist);
3338 if (--ppp->n_channels == 0)
3339 wake_up_interruptible(&ppp->file.rwait);
3340 ppp_unlock(ppp);
3341 if (refcount_dec_and_test(&ppp->file.refcnt))
3342 ppp_destroy_interface(ppp);
3343 err = 0;
3344 }
3345 return err;
3346 }
3347
3348 /*
3349 * Free up the resources used by a ppp channel.
3350 */
ppp_destroy_channel(struct channel * pch)3351 static void ppp_destroy_channel(struct channel *pch)
3352 {
3353 put_net(pch->chan_net);
3354 pch->chan_net = NULL;
3355
3356 atomic_dec(&channel_count);
3357
3358 if (!pch->file.dead) {
3359 /* "can't happen" */
3360 pr_err("ppp: destroying undead channel %p !\n", pch);
3361 return;
3362 }
3363 skb_queue_purge(&pch->file.xq);
3364 skb_queue_purge(&pch->file.rq);
3365 kfree(pch);
3366 }
3367
ppp_cleanup(void)3368 static void __exit ppp_cleanup(void)
3369 {
3370 /* should never happen */
3371 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
3372 pr_err("PPP: removing module but units remain!\n");
3373 rtnl_link_unregister(&ppp_link_ops);
3374 unregister_chrdev(PPP_MAJOR, "ppp");
3375 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
3376 class_destroy(ppp_class);
3377 unregister_pernet_device(&ppp_net_ops);
3378 }
3379
3380 /*
3381 * Units handling. Caller must protect concurrent access
3382 * by holding all_ppp_mutex
3383 */
3384
3385 /* associate pointer with specified number */
unit_set(struct idr * p,void * ptr,int n)3386 static int unit_set(struct idr *p, void *ptr, int n)
3387 {
3388 int unit;
3389
3390 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL);
3391 if (unit == -ENOSPC)
3392 unit = -EINVAL;
3393 return unit;
3394 }
3395
3396 /* get new free unit number and associate pointer with it */
unit_get(struct idr * p,void * ptr,int min)3397 static int unit_get(struct idr *p, void *ptr, int min)
3398 {
3399 return idr_alloc(p, ptr, min, 0, GFP_KERNEL);
3400 }
3401
3402 /* put unit number back to a pool */
unit_put(struct idr * p,int n)3403 static void unit_put(struct idr *p, int n)
3404 {
3405 idr_remove(p, n);
3406 }
3407
3408 /* get pointer associated with the number */
unit_find(struct idr * p,int n)3409 static void *unit_find(struct idr *p, int n)
3410 {
3411 return idr_find(p, n);
3412 }
3413
3414 /* Module/initialization stuff */
3415
3416 module_init(ppp_init);
3417 module_exit(ppp_cleanup);
3418
3419 EXPORT_SYMBOL(ppp_register_net_channel);
3420 EXPORT_SYMBOL(ppp_register_channel);
3421 EXPORT_SYMBOL(ppp_unregister_channel);
3422 EXPORT_SYMBOL(ppp_channel_index);
3423 EXPORT_SYMBOL(ppp_unit_number);
3424 EXPORT_SYMBOL(ppp_dev_name);
3425 EXPORT_SYMBOL(ppp_input);
3426 EXPORT_SYMBOL(ppp_input_error);
3427 EXPORT_SYMBOL(ppp_output_wakeup);
3428 EXPORT_SYMBOL(ppp_register_compressor);
3429 EXPORT_SYMBOL(ppp_unregister_compressor);
3430 MODULE_LICENSE("GPL");
3431 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
3432 MODULE_ALIAS_RTNL_LINK("ppp");
3433 MODULE_ALIAS("devname:ppp");
3434