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Linux 4.2.1
[linux/fpc-iii.git] / drivers / net / ppp / ppp_generic.c
blobfa8f5046afe90627242f6d2d523178da653c9427
1 /*
2 * Generic PPP layer for Linux.
3 *
4 * Copyright 1999-2002 Paul Mackerras.
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 *
11 * The generic PPP layer handles the PPP network interfaces, the
12 * /dev/ppp device, packet and VJ compression, and multilink.
13 * It talks to PPP `channels' via the interface defined in
14 * include/linux/ppp_channel.h. Channels provide the basic means for
15 * sending and receiving PPP frames on some kind of communications
16 * channel.
17 *
18 * Part of the code in this driver was inspired by the old async-only
19 * PPP driver, written by Michael Callahan and Al Longyear, and
20 * subsequently hacked by Paul Mackerras.
21 *
22 * ==FILEVERSION 20041108==
23 */
24
25 #include <linux/module.h>
26 #include <linux/kernel.h>
27 #include <linux/kmod.h>
28 #include <linux/init.h>
29 #include <linux/list.h>
30 #include <linux/idr.h>
31 #include <linux/netdevice.h>
32 #include <linux/poll.h>
33 #include <linux/ppp_defs.h>
34 #include <linux/filter.h>
35 #include <linux/ppp-ioctl.h>
36 #include <linux/ppp_channel.h>
37 #include <linux/ppp-comp.h>
38 #include <linux/skbuff.h>
39 #include <linux/rtnetlink.h>
40 #include <linux/if_arp.h>
41 #include <linux/ip.h>
42 #include <linux/tcp.h>
43 #include <linux/spinlock.h>
44 #include <linux/rwsem.h>
45 #include <linux/stddef.h>
46 #include <linux/device.h>
47 #include <linux/mutex.h>
48 #include <linux/slab.h>
49 #include <asm/unaligned.h>
50 #include <net/slhc_vj.h>
51 #include <linux/atomic.h>
52
53 #include <linux/nsproxy.h>
54 #include <net/net_namespace.h>
55 #include <net/netns/generic.h>
56
57 #define PPP_VERSION "2.4.2"
58
59 /*
60 * Network protocols we support.
61 */
62 #define NP_IP 0 /* Internet Protocol V4 */
63 #define NP_IPV6 1 /* Internet Protocol V6 */
64 #define NP_IPX 2 /* IPX protocol */
65 #define NP_AT 3 /* Appletalk protocol */
66 #define NP_MPLS_UC 4 /* MPLS unicast */
67 #define NP_MPLS_MC 5 /* MPLS multicast */
68 #define NUM_NP 6 /* Number of NPs. */
69
70 #define MPHDRLEN 6 /* multilink protocol header length */
71 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */
72
73 /*
74 * An instance of /dev/ppp can be associated with either a ppp
75 * interface unit or a ppp channel. In both cases, file->private_data
76 * points to one of these.
77 */
78 struct ppp_file {
79 enum {
80 INTERFACE=1, CHANNEL
81 } kind;
82 struct sk_buff_head xq; /* pppd transmit queue */
83 struct sk_buff_head rq; /* receive queue for pppd */
84 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */
85 atomic_t refcnt; /* # refs (incl /dev/ppp attached) */
86 int hdrlen; /* space to leave for headers */
87 int index; /* interface unit / channel number */
88 int dead; /* unit/channel has been shut down */
89 };
90
91 #define PF_TO_X(pf, X) container_of(pf, X, file)
92
93 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
94 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
95
96 /*
97 * Data structure to hold primary network stats for which
98 * we want to use 64 bit storage. Other network stats
99 * are stored in dev->stats of the ppp strucute.
100 */
101 struct ppp_link_stats {
102 u64 rx_packets;
103 u64 tx_packets;
104 u64 rx_bytes;
105 u64 tx_bytes;
106 };
107
108 /*
109 * Data structure describing one ppp unit.
110 * A ppp unit corresponds to a ppp network interface device
111 * and represents a multilink bundle.
112 * It can have 0 or more ppp channels connected to it.
113 */
114 struct ppp {
115 struct ppp_file file; /* stuff for read/write/poll 0 */
116 struct file *owner; /* file that owns this unit 48 */
117 struct list_head channels; /* list of attached channels 4c */
118 int n_channels; /* how many channels are attached 54 */
119 spinlock_t rlock; /* lock for receive side 58 */
120 spinlock_t wlock; /* lock for transmit side 5c */
121 int mru; /* max receive unit 60 */
122 unsigned int flags; /* control bits 64 */
123 unsigned int xstate; /* transmit state bits 68 */
124 unsigned int rstate; /* receive state bits 6c */
125 int debug; /* debug flags 70 */
126 struct slcompress *vj; /* state for VJ header compression */
127 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
128 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
129 struct compressor *xcomp; /* transmit packet compressor 8c */
130 void *xc_state; /* its internal state 90 */
131 struct compressor *rcomp; /* receive decompressor 94 */
132 void *rc_state; /* its internal state 98 */
133 unsigned long last_xmit; /* jiffies when last pkt sent 9c */
134 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
135 struct net_device *dev; /* network interface device a4 */
136 int closing; /* is device closing down? a8 */
137 #ifdef CONFIG_PPP_MULTILINK
138 int nxchan; /* next channel to send something on */
139 u32 nxseq; /* next sequence number to send */
140 int mrru; /* MP: max reconst. receive unit */
141 u32 nextseq; /* MP: seq no of next packet */
142 u32 minseq; /* MP: min of most recent seqnos */
143 struct sk_buff_head mrq; /* MP: receive reconstruction queue */
144 #endif /* CONFIG_PPP_MULTILINK */
145 #ifdef CONFIG_PPP_FILTER
146 struct bpf_prog *pass_filter; /* filter for packets to pass */
147 struct bpf_prog *active_filter; /* filter for pkts to reset idle */
148 #endif /* CONFIG_PPP_FILTER */
149 struct net *ppp_net; /* the net we belong to */
150 struct ppp_link_stats stats64; /* 64 bit network stats */
151 };
152
153 /*
154 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
155 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
156 * SC_MUST_COMP
157 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
158 * Bits in xstate: SC_COMP_RUN
159 */
160 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
161 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
162 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
163
164 /*
165 * Private data structure for each channel.
166 * This includes the data structure used for multilink.
167 */
168 struct channel {
169 struct ppp_file file; /* stuff for read/write/poll */
170 struct list_head list; /* link in all/new_channels list */
171 struct ppp_channel *chan; /* public channel data structure */
172 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
173 spinlock_t downl; /* protects `chan', file.xq dequeue */
174 struct ppp *ppp; /* ppp unit we're connected to */
175 struct net *chan_net; /* the net channel belongs to */
176 struct list_head clist; /* link in list of channels per unit */
177 rwlock_t upl; /* protects `ppp' */
178 #ifdef CONFIG_PPP_MULTILINK
179 u8 avail; /* flag used in multilink stuff */
180 u8 had_frag; /* >= 1 fragments have been sent */
181 u32 lastseq; /* MP: last sequence # received */
182 int speed; /* speed of the corresponding ppp channel*/
183 #endif /* CONFIG_PPP_MULTILINK */
184 };
185
186 /*
187 * SMP locking issues:
188 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
189 * list and the ppp.n_channels field, you need to take both locks
190 * before you modify them.
191 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
192 * channel.downl.
193 */
194
195 static DEFINE_MUTEX(ppp_mutex);
196 static atomic_t ppp_unit_count = ATOMIC_INIT(0);
197 static atomic_t channel_count = ATOMIC_INIT(0);
198
199 /* per-net private data for this module */
200 static int ppp_net_id __read_mostly;
201 struct ppp_net {
202 /* units to ppp mapping */
203 struct idr units_idr;
204
205 /*
206 * all_ppp_mutex protects the units_idr mapping.
207 * It also ensures that finding a ppp unit in the units_idr
208 * map and updating its file.refcnt field is atomic.
209 */
210 struct mutex all_ppp_mutex;
211
212 /* channels */
213 struct list_head all_channels;
214 struct list_head new_channels;
215 int last_channel_index;
216
217 /*
218 * all_channels_lock protects all_channels and
219 * last_channel_index, and the atomicity of find
220 * a channel and updating its file.refcnt field.
221 */
222 spinlock_t all_channels_lock;
223 };
224
225 /* Get the PPP protocol number from a skb */
226 #define PPP_PROTO(skb) get_unaligned_be16((skb)->data)
227
228 /* We limit the length of ppp->file.rq to this (arbitrary) value */
229 #define PPP_MAX_RQLEN 32
230
231 /*
232 * Maximum number of multilink fragments queued up.
233 * This has to be large enough to cope with the maximum latency of
234 * the slowest channel relative to the others. Strictly it should
235 * depend on the number of channels and their characteristics.
236 */
237 #define PPP_MP_MAX_QLEN 128
238
239 /* Multilink header bits. */
240 #define B 0x80 /* this fragment begins a packet */
241 #define E 0x40 /* this fragment ends a packet */
242
243 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */
244 #define seq_before(a, b) ((s32)((a) - (b)) < 0)
245 #define seq_after(a, b) ((s32)((a) - (b)) > 0)
246
247 /* Prototypes. */
248 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
249 struct file *file, unsigned int cmd, unsigned long arg);
250 static void ppp_xmit_process(struct ppp *ppp);
251 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
252 static void ppp_push(struct ppp *ppp);
253 static void ppp_channel_push(struct channel *pch);
254 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
255 struct channel *pch);
256 static void ppp_receive_error(struct ppp *ppp);
257 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
258 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
259 struct sk_buff *skb);
260 #ifdef CONFIG_PPP_MULTILINK
261 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
262 struct channel *pch);
263 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
264 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
265 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
266 #endif /* CONFIG_PPP_MULTILINK */
267 static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
268 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
269 static void ppp_ccp_closed(struct ppp *ppp);
270 static struct compressor *find_compressor(int type);
271 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
272 static struct ppp *ppp_create_interface(struct net *net, int unit,
273 struct file *file, int *retp);
274 static void init_ppp_file(struct ppp_file *pf, int kind);
275 static void ppp_destroy_interface(struct ppp *ppp);
276 static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit);
277 static struct channel *ppp_find_channel(struct ppp_net *pn, int unit);
278 static int ppp_connect_channel(struct channel *pch, int unit);
279 static int ppp_disconnect_channel(struct channel *pch);
280 static void ppp_destroy_channel(struct channel *pch);
281 static int unit_get(struct idr *p, void *ptr);
282 static int unit_set(struct idr *p, void *ptr, int n);
283 static void unit_put(struct idr *p, int n);
284 static void *unit_find(struct idr *p, int n);
285
286 static struct class *ppp_class;
287
288 /* per net-namespace data */
289 static inline struct ppp_net *ppp_pernet(struct net *net)
290 {
291 BUG_ON(!net);
292
293 return net_generic(net, ppp_net_id);
294 }
295
296 /* Translates a PPP protocol number to a NP index (NP == network protocol) */
297 static inline int proto_to_npindex(int proto)
298 {
299 switch (proto) {
300 case PPP_IP:
301 return NP_IP;
302 case PPP_IPV6:
303 return NP_IPV6;
304 case PPP_IPX:
305 return NP_IPX;
306 case PPP_AT:
307 return NP_AT;
308 case PPP_MPLS_UC:
309 return NP_MPLS_UC;
310 case PPP_MPLS_MC:
311 return NP_MPLS_MC;
312 }
313 return -EINVAL;
314 }
315
316 /* Translates an NP index into a PPP protocol number */
317 static const int npindex_to_proto[NUM_NP] = {
318 PPP_IP,
319 PPP_IPV6,
320 PPP_IPX,
321 PPP_AT,
322 PPP_MPLS_UC,
323 PPP_MPLS_MC,
324 };
325
326 /* Translates an ethertype into an NP index */
327 static inline int ethertype_to_npindex(int ethertype)
328 {
329 switch (ethertype) {
330 case ETH_P_IP:
331 return NP_IP;
332 case ETH_P_IPV6:
333 return NP_IPV6;
334 case ETH_P_IPX:
335 return NP_IPX;
336 case ETH_P_PPPTALK:
337 case ETH_P_ATALK:
338 return NP_AT;
339 case ETH_P_MPLS_UC:
340 return NP_MPLS_UC;
341 case ETH_P_MPLS_MC:
342 return NP_MPLS_MC;
343 }
344 return -1;
345 }
346
347 /* Translates an NP index into an ethertype */
348 static const int npindex_to_ethertype[NUM_NP] = {
349 ETH_P_IP,
350 ETH_P_IPV6,
351 ETH_P_IPX,
352 ETH_P_PPPTALK,
353 ETH_P_MPLS_UC,
354 ETH_P_MPLS_MC,
355 };
356
357 /*
358 * Locking shorthand.
359 */
360 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
361 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
362 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
363 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
364 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
365 ppp_recv_lock(ppp); } while (0)
366 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
367 ppp_xmit_unlock(ppp); } while (0)
368
369 /*
370 * /dev/ppp device routines.
371 * The /dev/ppp device is used by pppd to control the ppp unit.
372 * It supports the read, write, ioctl and poll functions.
373 * Open instances of /dev/ppp can be in one of three states:
374 * unattached, attached to a ppp unit, or attached to a ppp channel.
375 */
376 static int ppp_open(struct inode *inode, struct file *file)
377 {
378 /*
379 * This could (should?) be enforced by the permissions on /dev/ppp.
380 */
381 if (!capable(CAP_NET_ADMIN))
382 return -EPERM;
383 return 0;
384 }
385
386 static int ppp_release(struct inode *unused, struct file *file)
387 {
388 struct ppp_file *pf = file->private_data;
389 struct ppp *ppp;
390
391 if (pf) {
392 file->private_data = NULL;
393 if (pf->kind == INTERFACE) {
394 ppp = PF_TO_PPP(pf);
395 rtnl_lock();
396 if (file == ppp->owner)
397 unregister_netdevice(ppp->dev);
398 rtnl_unlock();
399 }
400 if (atomic_dec_and_test(&pf->refcnt)) {
401 switch (pf->kind) {
402 case INTERFACE:
403 ppp_destroy_interface(PF_TO_PPP(pf));
404 break;
405 case CHANNEL:
406 ppp_destroy_channel(PF_TO_CHANNEL(pf));
407 break;
408 }
409 }
410 }
411 return 0;
412 }
413
414 static ssize_t ppp_read(struct file *file, char __user *buf,
415 size_t count, loff_t *ppos)
416 {
417 struct ppp_file *pf = file->private_data;
418 DECLARE_WAITQUEUE(wait, current);
419 ssize_t ret;
420 struct sk_buff *skb = NULL;
421 struct iovec iov;
422 struct iov_iter to;
423
424 ret = count;
425
426 if (!pf)
427 return -ENXIO;
428 add_wait_queue(&pf->rwait, &wait);
429 for (;;) {
430 set_current_state(TASK_INTERRUPTIBLE);
431 skb = skb_dequeue(&pf->rq);
432 if (skb)
433 break;
434 ret = 0;
435 if (pf->dead)
436 break;
437 if (pf->kind == INTERFACE) {
438 /*
439 * Return 0 (EOF) on an interface that has no
440 * channels connected, unless it is looping
441 * network traffic (demand mode).
442 */
443 struct ppp *ppp = PF_TO_PPP(pf);
444 if (ppp->n_channels == 0 &&
445 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
446 break;
447 }
448 ret = -EAGAIN;
449 if (file->f_flags & O_NONBLOCK)
450 break;
451 ret = -ERESTARTSYS;
452 if (signal_pending(current))
453 break;
454 schedule();
455 }
456 set_current_state(TASK_RUNNING);
457 remove_wait_queue(&pf->rwait, &wait);
458
459 if (!skb)
460 goto out;
461
462 ret = -EOVERFLOW;
463 if (skb->len > count)
464 goto outf;
465 ret = -EFAULT;
466 iov.iov_base = buf;
467 iov.iov_len = count;
468 iov_iter_init(&to, READ, &iov, 1, count);
469 if (skb_copy_datagram_iter(skb, 0, &to, skb->len))
470 goto outf;
471 ret = skb->len;
472
473 outf:
474 kfree_skb(skb);
475 out:
476 return ret;
477 }
478
479 static ssize_t ppp_write(struct file *file, const char __user *buf,
480 size_t count, loff_t *ppos)
481 {
482 struct ppp_file *pf = file->private_data;
483 struct sk_buff *skb;
484 ssize_t ret;
485
486 if (!pf)
487 return -ENXIO;
488 ret = -ENOMEM;
489 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
490 if (!skb)
491 goto out;
492 skb_reserve(skb, pf->hdrlen);
493 ret = -EFAULT;
494 if (copy_from_user(skb_put(skb, count), buf, count)) {
495 kfree_skb(skb);
496 goto out;
497 }
498
499 skb_queue_tail(&pf->xq, skb);
500
501 switch (pf->kind) {
502 case INTERFACE:
503 ppp_xmit_process(PF_TO_PPP(pf));
504 break;
505 case CHANNEL:
506 ppp_channel_push(PF_TO_CHANNEL(pf));
507 break;
508 }
509
510 ret = count;
511
512 out:
513 return ret;
514 }
515
516 /* No kernel lock - fine */
517 static unsigned int ppp_poll(struct file *file, poll_table *wait)
518 {
519 struct ppp_file *pf = file->private_data;
520 unsigned int mask;
521
522 if (!pf)
523 return 0;
524 poll_wait(file, &pf->rwait, wait);
525 mask = POLLOUT | POLLWRNORM;
526 if (skb_peek(&pf->rq))
527 mask |= POLLIN | POLLRDNORM;
528 if (pf->dead)
529 mask |= POLLHUP;
530 else if (pf->kind == INTERFACE) {
531 /* see comment in ppp_read */
532 struct ppp *ppp = PF_TO_PPP(pf);
533 if (ppp->n_channels == 0 &&
534 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
535 mask |= POLLIN | POLLRDNORM;
536 }
537
538 return mask;
539 }
540
541 #ifdef CONFIG_PPP_FILTER
542 static int get_filter(void __user *arg, struct sock_filter **p)
543 {
544 struct sock_fprog uprog;
545 struct sock_filter *code = NULL;
546 int len;
547
548 if (copy_from_user(&uprog, arg, sizeof(uprog)))
549 return -EFAULT;
550
551 if (!uprog.len) {
552 *p = NULL;
553 return 0;
554 }
555
556 len = uprog.len * sizeof(struct sock_filter);
557 code = memdup_user(uprog.filter, len);
558 if (IS_ERR(code))
559 return PTR_ERR(code);
560
561 *p = code;
562 return uprog.len;
563 }
564 #endif /* CONFIG_PPP_FILTER */
565
566 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
567 {
568 struct ppp_file *pf = file->private_data;
569 struct ppp *ppp;
570 int err = -EFAULT, val, val2, i;
571 struct ppp_idle idle;
572 struct npioctl npi;
573 int unit, cflags;
574 struct slcompress *vj;
575 void __user *argp = (void __user *)arg;
576 int __user *p = argp;
577
578 if (!pf)
579 return ppp_unattached_ioctl(current->nsproxy->net_ns,
580 pf, file, cmd, arg);
581
582 if (cmd == PPPIOCDETACH) {
583 /*
584 * We have to be careful here... if the file descriptor
585 * has been dup'd, we could have another process in the
586 * middle of a poll using the same file *, so we had
587 * better not free the interface data structures -
588 * instead we fail the ioctl. Even in this case, we
589 * shut down the interface if we are the owner of it.
590 * Actually, we should get rid of PPPIOCDETACH, userland
591 * (i.e. pppd) could achieve the same effect by closing
592 * this fd and reopening /dev/ppp.
593 */
594 err = -EINVAL;
595 mutex_lock(&ppp_mutex);
596 if (pf->kind == INTERFACE) {
597 ppp = PF_TO_PPP(pf);
598 rtnl_lock();
599 if (file == ppp->owner)
600 unregister_netdevice(ppp->dev);
601 rtnl_unlock();
602 }
603 if (atomic_long_read(&file->f_count) < 2) {
604 ppp_release(NULL, file);
605 err = 0;
606 } else
607 pr_warn("PPPIOCDETACH file->f_count=%ld\n",
608 atomic_long_read(&file->f_count));
609 mutex_unlock(&ppp_mutex);
610 return err;
611 }
612
613 if (pf->kind == CHANNEL) {
614 struct channel *pch;
615 struct ppp_channel *chan;
616
617 mutex_lock(&ppp_mutex);
618 pch = PF_TO_CHANNEL(pf);
619
620 switch (cmd) {
621 case PPPIOCCONNECT:
622 if (get_user(unit, p))
623 break;
624 err = ppp_connect_channel(pch, unit);
625 break;
626
627 case PPPIOCDISCONN:
628 err = ppp_disconnect_channel(pch);
629 break;
630
631 default:
632 down_read(&pch->chan_sem);
633 chan = pch->chan;
634 err = -ENOTTY;
635 if (chan && chan->ops->ioctl)
636 err = chan->ops->ioctl(chan, cmd, arg);
637 up_read(&pch->chan_sem);
638 }
639 mutex_unlock(&ppp_mutex);
640 return err;
641 }
642
643 if (pf->kind != INTERFACE) {
644 /* can't happen */
645 pr_err("PPP: not interface or channel??\n");
646 return -EINVAL;
647 }
648
649 mutex_lock(&ppp_mutex);
650 ppp = PF_TO_PPP(pf);
651 switch (cmd) {
652 case PPPIOCSMRU:
653 if (get_user(val, p))
654 break;
655 ppp->mru = val;
656 err = 0;
657 break;
658
659 case PPPIOCSFLAGS:
660 if (get_user(val, p))
661 break;
662 ppp_lock(ppp);
663 cflags = ppp->flags & ~val;
664 #ifdef CONFIG_PPP_MULTILINK
665 if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK))
666 ppp->nextseq = 0;
667 #endif
668 ppp->flags = val & SC_FLAG_BITS;
669 ppp_unlock(ppp);
670 if (cflags & SC_CCP_OPEN)
671 ppp_ccp_closed(ppp);
672 err = 0;
673 break;
674
675 case PPPIOCGFLAGS:
676 val = ppp->flags | ppp->xstate | ppp->rstate;
677 if (put_user(val, p))
678 break;
679 err = 0;
680 break;
681
682 case PPPIOCSCOMPRESS:
683 err = ppp_set_compress(ppp, arg);
684 break;
685
686 case PPPIOCGUNIT:
687 if (put_user(ppp->file.index, p))
688 break;
689 err = 0;
690 break;
691
692 case PPPIOCSDEBUG:
693 if (get_user(val, p))
694 break;
695 ppp->debug = val;
696 err = 0;
697 break;
698
699 case PPPIOCGDEBUG:
700 if (put_user(ppp->debug, p))
701 break;
702 err = 0;
703 break;
704
705 case PPPIOCGIDLE:
706 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
707 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
708 if (copy_to_user(argp, &idle, sizeof(idle)))
709 break;
710 err = 0;
711 break;
712
713 case PPPIOCSMAXCID:
714 if (get_user(val, p))
715 break;
716 val2 = 15;
717 if ((val >> 16) != 0) {
718 val2 = val >> 16;
719 val &= 0xffff;
720 }
721 vj = slhc_init(val2+1, val+1);
722 if (!vj) {
723 netdev_err(ppp->dev,
724 "PPP: no memory (VJ compressor)\n");
725 err = -ENOMEM;
726 break;
727 }
728 ppp_lock(ppp);
729 if (ppp->vj)
730 slhc_free(ppp->vj);
731 ppp->vj = vj;
732 ppp_unlock(ppp);
733 err = 0;
734 break;
735
736 case PPPIOCGNPMODE:
737 case PPPIOCSNPMODE:
738 if (copy_from_user(&npi, argp, sizeof(npi)))
739 break;
740 err = proto_to_npindex(npi.protocol);
741 if (err < 0)
742 break;
743 i = err;
744 if (cmd == PPPIOCGNPMODE) {
745 err = -EFAULT;
746 npi.mode = ppp->npmode[i];
747 if (copy_to_user(argp, &npi, sizeof(npi)))
748 break;
749 } else {
750 ppp->npmode[i] = npi.mode;
751 /* we may be able to transmit more packets now (??) */
752 netif_wake_queue(ppp->dev);
753 }
754 err = 0;
755 break;
756
757 #ifdef CONFIG_PPP_FILTER
758 case PPPIOCSPASS:
759 {
760 struct sock_filter *code;
761
762 err = get_filter(argp, &code);
763 if (err >= 0) {
764 struct bpf_prog *pass_filter = NULL;
765 struct sock_fprog_kern fprog = {
766 .len = err,
767 .filter = code,
768 };
769
770 err = 0;
771 if (fprog.filter)
772 err = bpf_prog_create(&pass_filter, &fprog);
773 if (!err) {
774 ppp_lock(ppp);
775 if (ppp->pass_filter)
776 bpf_prog_destroy(ppp->pass_filter);
777 ppp->pass_filter = pass_filter;
778 ppp_unlock(ppp);
779 }
780 kfree(code);
781 }
782 break;
783 }
784 case PPPIOCSACTIVE:
785 {
786 struct sock_filter *code;
787
788 err = get_filter(argp, &code);
789 if (err >= 0) {
790 struct bpf_prog *active_filter = NULL;
791 struct sock_fprog_kern fprog = {
792 .len = err,
793 .filter = code,
794 };
795
796 err = 0;
797 if (fprog.filter)
798 err = bpf_prog_create(&active_filter, &fprog);
799 if (!err) {
800 ppp_lock(ppp);
801 if (ppp->active_filter)
802 bpf_prog_destroy(ppp->active_filter);
803 ppp->active_filter = active_filter;
804 ppp_unlock(ppp);
805 }
806 kfree(code);
807 }
808 break;
809 }
810 #endif /* CONFIG_PPP_FILTER */
811
812 #ifdef CONFIG_PPP_MULTILINK
813 case PPPIOCSMRRU:
814 if (get_user(val, p))
815 break;
816 ppp_recv_lock(ppp);
817 ppp->mrru = val;
818 ppp_recv_unlock(ppp);
819 err = 0;
820 break;
821 #endif /* CONFIG_PPP_MULTILINK */
822
823 default:
824 err = -ENOTTY;
825 }
826 mutex_unlock(&ppp_mutex);
827 return err;
828 }
829
830 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
831 struct file *file, unsigned int cmd, unsigned long arg)
832 {
833 int unit, err = -EFAULT;
834 struct ppp *ppp;
835 struct channel *chan;
836 struct ppp_net *pn;
837 int __user *p = (int __user *)arg;
838
839 mutex_lock(&ppp_mutex);
840 switch (cmd) {
841 case PPPIOCNEWUNIT:
842 /* Create a new ppp unit */
843 if (get_user(unit, p))
844 break;
845 ppp = ppp_create_interface(net, unit, file, &err);
846 if (!ppp)
847 break;
848 file->private_data = &ppp->file;
849 err = -EFAULT;
850 if (put_user(ppp->file.index, p))
851 break;
852 err = 0;
853 break;
854
855 case PPPIOCATTACH:
856 /* Attach to an existing ppp unit */
857 if (get_user(unit, p))
858 break;
859 err = -ENXIO;
860 pn = ppp_pernet(net);
861 mutex_lock(&pn->all_ppp_mutex);
862 ppp = ppp_find_unit(pn, unit);
863 if (ppp) {
864 atomic_inc(&ppp->file.refcnt);
865 file->private_data = &ppp->file;
866 err = 0;
867 }
868 mutex_unlock(&pn->all_ppp_mutex);
869 break;
870
871 case PPPIOCATTCHAN:
872 if (get_user(unit, p))
873 break;
874 err = -ENXIO;
875 pn = ppp_pernet(net);
876 spin_lock_bh(&pn->all_channels_lock);
877 chan = ppp_find_channel(pn, unit);
878 if (chan) {
879 atomic_inc(&chan->file.refcnt);
880 file->private_data = &chan->file;
881 err = 0;
882 }
883 spin_unlock_bh(&pn->all_channels_lock);
884 break;
885
886 default:
887 err = -ENOTTY;
888 }
889 mutex_unlock(&ppp_mutex);
890 return err;
891 }
892
893 static const struct file_operations ppp_device_fops = {
894 .owner = THIS_MODULE,
895 .read = ppp_read,
896 .write = ppp_write,
897 .poll = ppp_poll,
898 .unlocked_ioctl = ppp_ioctl,
899 .open = ppp_open,
900 .release = ppp_release,
901 .llseek = noop_llseek,
902 };
903
904 static __net_init int ppp_init_net(struct net *net)
905 {
906 struct ppp_net *pn = net_generic(net, ppp_net_id);
907
908 idr_init(&pn->units_idr);
909 mutex_init(&pn->all_ppp_mutex);
910
911 INIT_LIST_HEAD(&pn->all_channels);
912 INIT_LIST_HEAD(&pn->new_channels);
913
914 spin_lock_init(&pn->all_channels_lock);
915
916 return 0;
917 }
918
919 static __net_exit void ppp_exit_net(struct net *net)
920 {
921 struct ppp_net *pn = net_generic(net, ppp_net_id);
922 struct ppp *ppp;
923 LIST_HEAD(list);
924 int id;
925
926 rtnl_lock();
927 idr_for_each_entry(&pn->units_idr, ppp, id)
928 unregister_netdevice_queue(ppp->dev, &list);
929
930 unregister_netdevice_many(&list);
931 rtnl_unlock();
932
933 idr_destroy(&pn->units_idr);
934 }
935
936 static struct pernet_operations ppp_net_ops = {
937 .init = ppp_init_net,
938 .exit = ppp_exit_net,
939 .id = &ppp_net_id,
940 .size = sizeof(struct ppp_net),
941 };
942
943 #define PPP_MAJOR 108
944
945 /* Called at boot time if ppp is compiled into the kernel,
946 or at module load time (from init_module) if compiled as a module. */
947 static int __init ppp_init(void)
948 {
949 int err;
950
951 pr_info("PPP generic driver version " PPP_VERSION "\n");
952
953 err = register_pernet_device(&ppp_net_ops);
954 if (err) {
955 pr_err("failed to register PPP pernet device (%d)\n", err);
956 goto out;
957 }
958
959 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
960 if (err) {
961 pr_err("failed to register PPP device (%d)\n", err);
962 goto out_net;
963 }
964
965 ppp_class = class_create(THIS_MODULE, "ppp");
966 if (IS_ERR(ppp_class)) {
967 err = PTR_ERR(ppp_class);
968 goto out_chrdev;
969 }
970
971 /* not a big deal if we fail here :-) */
972 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
973
974 return 0;
975
976 out_chrdev:
977 unregister_chrdev(PPP_MAJOR, "ppp");
978 out_net:
979 unregister_pernet_device(&ppp_net_ops);
980 out:
981 return err;
982 }
983
984 /*
985 * Network interface unit routines.
986 */
987 static netdev_tx_t
988 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
989 {
990 struct ppp *ppp = netdev_priv(dev);
991 int npi, proto;
992 unsigned char *pp;
993
994 npi = ethertype_to_npindex(ntohs(skb->protocol));
995 if (npi < 0)
996 goto outf;
997
998 /* Drop, accept or reject the packet */
999 switch (ppp->npmode[npi]) {
1000 case NPMODE_PASS:
1001 break;
1002 case NPMODE_QUEUE:
1003 /* it would be nice to have a way to tell the network
1004 system to queue this one up for later. */
1005 goto outf;
1006 case NPMODE_DROP:
1007 case NPMODE_ERROR:
1008 goto outf;
1009 }
1010
1011 /* Put the 2-byte PPP protocol number on the front,
1012 making sure there is room for the address and control fields. */
1013 if (skb_cow_head(skb, PPP_HDRLEN))
1014 goto outf;
1015
1016 pp = skb_push(skb, 2);
1017 proto = npindex_to_proto[npi];
1018 put_unaligned_be16(proto, pp);
1019
1020 skb_queue_tail(&ppp->file.xq, skb);
1021 ppp_xmit_process(ppp);
1022 return NETDEV_TX_OK;
1023
1024 outf:
1025 kfree_skb(skb);
1026 ++dev->stats.tx_dropped;
1027 return NETDEV_TX_OK;
1028 }
1029
1030 static int
1031 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1032 {
1033 struct ppp *ppp = netdev_priv(dev);
1034 int err = -EFAULT;
1035 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
1036 struct ppp_stats stats;
1037 struct ppp_comp_stats cstats;
1038 char *vers;
1039
1040 switch (cmd) {
1041 case SIOCGPPPSTATS:
1042 ppp_get_stats(ppp, &stats);
1043 if (copy_to_user(addr, &stats, sizeof(stats)))
1044 break;
1045 err = 0;
1046 break;
1047
1048 case SIOCGPPPCSTATS:
1049 memset(&cstats, 0, sizeof(cstats));
1050 if (ppp->xc_state)
1051 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
1052 if (ppp->rc_state)
1053 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
1054 if (copy_to_user(addr, &cstats, sizeof(cstats)))
1055 break;
1056 err = 0;
1057 break;
1058
1059 case SIOCGPPPVER:
1060 vers = PPP_VERSION;
1061 if (copy_to_user(addr, vers, strlen(vers) + 1))
1062 break;
1063 err = 0;
1064 break;
1065
1066 default:
1067 err = -EINVAL;
1068 }
1069
1070 return err;
1071 }
1072
1073 static struct rtnl_link_stats64*
1074 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64)
1075 {
1076 struct ppp *ppp = netdev_priv(dev);
1077
1078 ppp_recv_lock(ppp);
1079 stats64->rx_packets = ppp->stats64.rx_packets;
1080 stats64->rx_bytes = ppp->stats64.rx_bytes;
1081 ppp_recv_unlock(ppp);
1082
1083 ppp_xmit_lock(ppp);
1084 stats64->tx_packets = ppp->stats64.tx_packets;
1085 stats64->tx_bytes = ppp->stats64.tx_bytes;
1086 ppp_xmit_unlock(ppp);
1087
1088 stats64->rx_errors = dev->stats.rx_errors;
1089 stats64->tx_errors = dev->stats.tx_errors;
1090 stats64->rx_dropped = dev->stats.rx_dropped;
1091 stats64->tx_dropped = dev->stats.tx_dropped;
1092 stats64->rx_length_errors = dev->stats.rx_length_errors;
1093
1094 return stats64;
1095 }
1096
1097 static struct lock_class_key ppp_tx_busylock;
1098 static int ppp_dev_init(struct net_device *dev)
1099 {
1100 dev->qdisc_tx_busylock = &ppp_tx_busylock;
1101 return 0;
1102 }
1103
1104 static void ppp_dev_uninit(struct net_device *dev)
1105 {
1106 struct ppp *ppp = netdev_priv(dev);
1107 struct ppp_net *pn = ppp_pernet(ppp->ppp_net);
1108
1109 ppp_lock(ppp);
1110 ppp->closing = 1;
1111 ppp_unlock(ppp);
1112
1113 mutex_lock(&pn->all_ppp_mutex);
1114 unit_put(&pn->units_idr, ppp->file.index);
1115 mutex_unlock(&pn->all_ppp_mutex);
1116
1117 ppp->owner = NULL;
1118
1119 ppp->file.dead = 1;
1120 wake_up_interruptible(&ppp->file.rwait);
1121 }
1122
1123 static const struct net_device_ops ppp_netdev_ops = {
1124 .ndo_init = ppp_dev_init,
1125 .ndo_uninit = ppp_dev_uninit,
1126 .ndo_start_xmit = ppp_start_xmit,
1127 .ndo_do_ioctl = ppp_net_ioctl,
1128 .ndo_get_stats64 = ppp_get_stats64,
1129 };
1130
1131 static void ppp_setup(struct net_device *dev)
1132 {
1133 dev->netdev_ops = &ppp_netdev_ops;
1134 dev->hard_header_len = PPP_HDRLEN;
1135 dev->mtu = PPP_MRU;
1136 dev->addr_len = 0;
1137 dev->tx_queue_len = 3;
1138 dev->type = ARPHRD_PPP;
1139 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1140 dev->features |= NETIF_F_NETNS_LOCAL;
1141 netif_keep_dst(dev);
1142 }
1143
1144 /*
1145 * Transmit-side routines.
1146 */
1147
1148 /*
1149 * Called to do any work queued up on the transmit side
1150 * that can now be done.
1151 */
1152 static void
1153 ppp_xmit_process(struct ppp *ppp)
1154 {
1155 struct sk_buff *skb;
1156
1157 ppp_xmit_lock(ppp);
1158 if (!ppp->closing) {
1159 ppp_push(ppp);
1160 while (!ppp->xmit_pending &&
1161 (skb = skb_dequeue(&ppp->file.xq)))
1162 ppp_send_frame(ppp, skb);
1163 /* If there's no work left to do, tell the core net
1164 code that we can accept some more. */
1165 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1166 netif_wake_queue(ppp->dev);
1167 else
1168 netif_stop_queue(ppp->dev);
1169 }
1170 ppp_xmit_unlock(ppp);
1171 }
1172
1173 static inline struct sk_buff *
1174 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1175 {
1176 struct sk_buff *new_skb;
1177 int len;
1178 int new_skb_size = ppp->dev->mtu +
1179 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1180 int compressor_skb_size = ppp->dev->mtu +
1181 ppp->xcomp->comp_extra + PPP_HDRLEN;
1182 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1183 if (!new_skb) {
1184 if (net_ratelimit())
1185 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n");
1186 return NULL;
1187 }
1188 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1189 skb_reserve(new_skb,
1190 ppp->dev->hard_header_len - PPP_HDRLEN);
1191
1192 /* compressor still expects A/C bytes in hdr */
1193 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1194 new_skb->data, skb->len + 2,
1195 compressor_skb_size);
1196 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1197 consume_skb(skb);
1198 skb = new_skb;
1199 skb_put(skb, len);
1200 skb_pull(skb, 2); /* pull off A/C bytes */
1201 } else if (len == 0) {
1202 /* didn't compress, or CCP not up yet */
1203 consume_skb(new_skb);
1204 new_skb = skb;
1205 } else {
1206 /*
1207 * (len < 0)
1208 * MPPE requires that we do not send unencrypted
1209 * frames. The compressor will return -1 if we
1210 * should drop the frame. We cannot simply test
1211 * the compress_proto because MPPE and MPPC share
1212 * the same number.
1213 */
1214 if (net_ratelimit())
1215 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n");
1216 kfree_skb(skb);
1217 consume_skb(new_skb);
1218 new_skb = NULL;
1219 }
1220 return new_skb;
1221 }
1222
1223 /*
1224 * Compress and send a frame.
1225 * The caller should have locked the xmit path,
1226 * and xmit_pending should be 0.
1227 */
1228 static void
1229 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1230 {
1231 int proto = PPP_PROTO(skb);
1232 struct sk_buff *new_skb;
1233 int len;
1234 unsigned char *cp;
1235
1236 if (proto < 0x8000) {
1237 #ifdef CONFIG_PPP_FILTER
1238 /* check if we should pass this packet */
1239 /* the filter instructions are constructed assuming
1240 a four-byte PPP header on each packet */
1241 *skb_push(skb, 2) = 1;
1242 if (ppp->pass_filter &&
1243 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
1244 if (ppp->debug & 1)
1245 netdev_printk(KERN_DEBUG, ppp->dev,
1246 "PPP: outbound frame "
1247 "not passed\n");
1248 kfree_skb(skb);
1249 return;
1250 }
1251 /* if this packet passes the active filter, record the time */
1252 if (!(ppp->active_filter &&
1253 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
1254 ppp->last_xmit = jiffies;
1255 skb_pull(skb, 2);
1256 #else
1257 /* for data packets, record the time */
1258 ppp->last_xmit = jiffies;
1259 #endif /* CONFIG_PPP_FILTER */
1260 }
1261
1262 ++ppp->stats64.tx_packets;
1263 ppp->stats64.tx_bytes += skb->len - 2;
1264
1265 switch (proto) {
1266 case PPP_IP:
1267 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1268 break;
1269 /* try to do VJ TCP header compression */
1270 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1271 GFP_ATOMIC);
1272 if (!new_skb) {
1273 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n");
1274 goto drop;
1275 }
1276 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1277 cp = skb->data + 2;
1278 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1279 new_skb->data + 2, &cp,
1280 !(ppp->flags & SC_NO_TCP_CCID));
1281 if (cp == skb->data + 2) {
1282 /* didn't compress */
1283 consume_skb(new_skb);
1284 } else {
1285 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1286 proto = PPP_VJC_COMP;
1287 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1288 } else {
1289 proto = PPP_VJC_UNCOMP;
1290 cp[0] = skb->data[2];
1291 }
1292 consume_skb(skb);
1293 skb = new_skb;
1294 cp = skb_put(skb, len + 2);
1295 cp[0] = 0;
1296 cp[1] = proto;
1297 }
1298 break;
1299
1300 case PPP_CCP:
1301 /* peek at outbound CCP frames */
1302 ppp_ccp_peek(ppp, skb, 0);
1303 break;
1304 }
1305
1306 /* try to do packet compression */
1307 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state &&
1308 proto != PPP_LCP && proto != PPP_CCP) {
1309 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1310 if (net_ratelimit())
1311 netdev_err(ppp->dev,
1312 "ppp: compression required but "
1313 "down - pkt dropped.\n");
1314 goto drop;
1315 }
1316 skb = pad_compress_skb(ppp, skb);
1317 if (!skb)
1318 goto drop;
1319 }
1320
1321 /*
1322 * If we are waiting for traffic (demand dialling),
1323 * queue it up for pppd to receive.
1324 */
1325 if (ppp->flags & SC_LOOP_TRAFFIC) {
1326 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1327 goto drop;
1328 skb_queue_tail(&ppp->file.rq, skb);
1329 wake_up_interruptible(&ppp->file.rwait);
1330 return;
1331 }
1332
1333 ppp->xmit_pending = skb;
1334 ppp_push(ppp);
1335 return;
1336
1337 drop:
1338 kfree_skb(skb);
1339 ++ppp->dev->stats.tx_errors;
1340 }
1341
1342 /*
1343 * Try to send the frame in xmit_pending.
1344 * The caller should have the xmit path locked.
1345 */
1346 static void
1347 ppp_push(struct ppp *ppp)
1348 {
1349 struct list_head *list;
1350 struct channel *pch;
1351 struct sk_buff *skb = ppp->xmit_pending;
1352
1353 if (!skb)
1354 return;
1355
1356 list = &ppp->channels;
1357 if (list_empty(list)) {
1358 /* nowhere to send the packet, just drop it */
1359 ppp->xmit_pending = NULL;
1360 kfree_skb(skb);
1361 return;
1362 }
1363
1364 if ((ppp->flags & SC_MULTILINK) == 0) {
1365 /* not doing multilink: send it down the first channel */
1366 list = list->next;
1367 pch = list_entry(list, struct channel, clist);
1368
1369 spin_lock_bh(&pch->downl);
1370 if (pch->chan) {
1371 if (pch->chan->ops->start_xmit(pch->chan, skb))
1372 ppp->xmit_pending = NULL;
1373 } else {
1374 /* channel got unregistered */
1375 kfree_skb(skb);
1376 ppp->xmit_pending = NULL;
1377 }
1378 spin_unlock_bh(&pch->downl);
1379 return;
1380 }
1381
1382 #ifdef CONFIG_PPP_MULTILINK
1383 /* Multilink: fragment the packet over as many links
1384 as can take the packet at the moment. */
1385 if (!ppp_mp_explode(ppp, skb))
1386 return;
1387 #endif /* CONFIG_PPP_MULTILINK */
1388
1389 ppp->xmit_pending = NULL;
1390 kfree_skb(skb);
1391 }
1392
1393 #ifdef CONFIG_PPP_MULTILINK
1394 static bool mp_protocol_compress __read_mostly = true;
1395 module_param(mp_protocol_compress, bool, S_IRUGO | S_IWUSR);
1396 MODULE_PARM_DESC(mp_protocol_compress,
1397 "compress protocol id in multilink fragments");
1398
1399 /*
1400 * Divide a packet to be transmitted into fragments and
1401 * send them out the individual links.
1402 */
1403 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1404 {
1405 int len, totlen;
1406 int i, bits, hdrlen, mtu;
1407 int flen;
1408 int navail, nfree, nzero;
1409 int nbigger;
1410 int totspeed;
1411 int totfree;
1412 unsigned char *p, *q;
1413 struct list_head *list;
1414 struct channel *pch;
1415 struct sk_buff *frag;
1416 struct ppp_channel *chan;
1417
1418 totspeed = 0; /*total bitrate of the bundle*/
1419 nfree = 0; /* # channels which have no packet already queued */
1420 navail = 0; /* total # of usable channels (not deregistered) */
1421 nzero = 0; /* number of channels with zero speed associated*/
1422 totfree = 0; /*total # of channels available and
1423 *having no queued packets before
1424 *starting the fragmentation*/
1425
1426 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1427 i = 0;
1428 list_for_each_entry(pch, &ppp->channels, clist) {
1429 if (pch->chan) {
1430 pch->avail = 1;
1431 navail++;
1432 pch->speed = pch->chan->speed;
1433 } else {
1434 pch->avail = 0;
1435 }
1436 if (pch->avail) {
1437 if (skb_queue_empty(&pch->file.xq) ||
1438 !pch->had_frag) {
1439 if (pch->speed == 0)
1440 nzero++;
1441 else
1442 totspeed += pch->speed;
1443
1444 pch->avail = 2;
1445 ++nfree;
1446 ++totfree;
1447 }
1448 if (!pch->had_frag && i < ppp->nxchan)
1449 ppp->nxchan = i;
1450 }
1451 ++i;
1452 }
1453 /*
1454 * Don't start sending this packet unless at least half of
1455 * the channels are free. This gives much better TCP
1456 * performance if we have a lot of channels.
1457 */
1458 if (nfree == 0 || nfree < navail / 2)
1459 return 0; /* can't take now, leave it in xmit_pending */
1460
1461 /* Do protocol field compression */
1462 p = skb->data;
1463 len = skb->len;
1464 if (*p == 0 && mp_protocol_compress) {
1465 ++p;
1466 --len;
1467 }
1468
1469 totlen = len;
1470 nbigger = len % nfree;
1471
1472 /* skip to the channel after the one we last used
1473 and start at that one */
1474 list = &ppp->channels;
1475 for (i = 0; i < ppp->nxchan; ++i) {
1476 list = list->next;
1477 if (list == &ppp->channels) {
1478 i = 0;
1479 break;
1480 }
1481 }
1482
1483 /* create a fragment for each channel */
1484 bits = B;
1485 while (len > 0) {
1486 list = list->next;
1487 if (list == &ppp->channels) {
1488 i = 0;
1489 continue;
1490 }
1491 pch = list_entry(list, struct channel, clist);
1492 ++i;
1493 if (!pch->avail)
1494 continue;
1495
1496 /*
1497 * Skip this channel if it has a fragment pending already and
1498 * we haven't given a fragment to all of the free channels.
1499 */
1500 if (pch->avail == 1) {
1501 if (nfree > 0)
1502 continue;
1503 } else {
1504 pch->avail = 1;
1505 }
1506
1507 /* check the channel's mtu and whether it is still attached. */
1508 spin_lock_bh(&pch->downl);
1509 if (pch->chan == NULL) {
1510 /* can't use this channel, it's being deregistered */
1511 if (pch->speed == 0)
1512 nzero--;
1513 else
1514 totspeed -= pch->speed;
1515
1516 spin_unlock_bh(&pch->downl);
1517 pch->avail = 0;
1518 totlen = len;
1519 totfree--;
1520 nfree--;
1521 if (--navail == 0)
1522 break;
1523 continue;
1524 }
1525
1526 /*
1527 *if the channel speed is not set divide
1528 *the packet evenly among the free channels;
1529 *otherwise divide it according to the speed
1530 *of the channel we are going to transmit on
1531 */
1532 flen = len;
1533 if (nfree > 0) {
1534 if (pch->speed == 0) {
1535 flen = len/nfree;
1536 if (nbigger > 0) {
1537 flen++;
1538 nbigger--;
1539 }
1540 } else {
1541 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
1542 ((totspeed*totfree)/pch->speed)) - hdrlen;
1543 if (nbigger > 0) {
1544 flen += ((totfree - nzero)*pch->speed)/totspeed;
1545 nbigger -= ((totfree - nzero)*pch->speed)/
1546 totspeed;
1547 }
1548 }
1549 nfree--;
1550 }
1551
1552 /*
1553 *check if we are on the last channel or
1554 *we exceded the length of the data to
1555 *fragment
1556 */
1557 if ((nfree <= 0) || (flen > len))
1558 flen = len;
1559 /*
1560 *it is not worth to tx on slow channels:
1561 *in that case from the resulting flen according to the
1562 *above formula will be equal or less than zero.
1563 *Skip the channel in this case
1564 */
1565 if (flen <= 0) {
1566 pch->avail = 2;
1567 spin_unlock_bh(&pch->downl);
1568 continue;
1569 }
1570
1571 /*
1572 * hdrlen includes the 2-byte PPP protocol field, but the
1573 * MTU counts only the payload excluding the protocol field.
1574 * (RFC1661 Section 2)
1575 */
1576 mtu = pch->chan->mtu - (hdrlen - 2);
1577 if (mtu < 4)
1578 mtu = 4;
1579 if (flen > mtu)
1580 flen = mtu;
1581 if (flen == len)
1582 bits |= E;
1583 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1584 if (!frag)
1585 goto noskb;
1586 q = skb_put(frag, flen + hdrlen);
1587
1588 /* make the MP header */
1589 put_unaligned_be16(PPP_MP, q);
1590 if (ppp->flags & SC_MP_XSHORTSEQ) {
1591 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1592 q[3] = ppp->nxseq;
1593 } else {
1594 q[2] = bits;
1595 q[3] = ppp->nxseq >> 16;
1596 q[4] = ppp->nxseq >> 8;
1597 q[5] = ppp->nxseq;
1598 }
1599
1600 memcpy(q + hdrlen, p, flen);
1601
1602 /* try to send it down the channel */
1603 chan = pch->chan;
1604 if (!skb_queue_empty(&pch->file.xq) ||
1605 !chan->ops->start_xmit(chan, frag))
1606 skb_queue_tail(&pch->file.xq, frag);
1607 pch->had_frag = 1;
1608 p += flen;
1609 len -= flen;
1610 ++ppp->nxseq;
1611 bits = 0;
1612 spin_unlock_bh(&pch->downl);
1613 }
1614 ppp->nxchan = i;
1615
1616 return 1;
1617
1618 noskb:
1619 spin_unlock_bh(&pch->downl);
1620 if (ppp->debug & 1)
1621 netdev_err(ppp->dev, "PPP: no memory (fragment)\n");
1622 ++ppp->dev->stats.tx_errors;
1623 ++ppp->nxseq;
1624 return 1; /* abandon the frame */
1625 }
1626 #endif /* CONFIG_PPP_MULTILINK */
1627
1628 /*
1629 * Try to send data out on a channel.
1630 */
1631 static void
1632 ppp_channel_push(struct channel *pch)
1633 {
1634 struct sk_buff *skb;
1635 struct ppp *ppp;
1636
1637 spin_lock_bh(&pch->downl);
1638 if (pch->chan) {
1639 while (!skb_queue_empty(&pch->file.xq)) {
1640 skb = skb_dequeue(&pch->file.xq);
1641 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1642 /* put the packet back and try again later */
1643 skb_queue_head(&pch->file.xq, skb);
1644 break;
1645 }
1646 }
1647 } else {
1648 /* channel got deregistered */
1649 skb_queue_purge(&pch->file.xq);
1650 }
1651 spin_unlock_bh(&pch->downl);
1652 /* see if there is anything from the attached unit to be sent */
1653 if (skb_queue_empty(&pch->file.xq)) {
1654 read_lock_bh(&pch->upl);
1655 ppp = pch->ppp;
1656 if (ppp)
1657 ppp_xmit_process(ppp);
1658 read_unlock_bh(&pch->upl);
1659 }
1660 }
1661
1662 /*
1663 * Receive-side routines.
1664 */
1665
1666 struct ppp_mp_skb_parm {
1667 u32 sequence;
1668 u8 BEbits;
1669 };
1670 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb))
1671
1672 static inline void
1673 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1674 {
1675 ppp_recv_lock(ppp);
1676 if (!ppp->closing)
1677 ppp_receive_frame(ppp, skb, pch);
1678 else
1679 kfree_skb(skb);
1680 ppp_recv_unlock(ppp);
1681 }
1682
1683 void
1684 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1685 {
1686 struct channel *pch = chan->ppp;
1687 int proto;
1688
1689 if (!pch) {
1690 kfree_skb(skb);
1691 return;
1692 }
1693
1694 read_lock_bh(&pch->upl);
1695 if (!pskb_may_pull(skb, 2)) {
1696 kfree_skb(skb);
1697 if (pch->ppp) {
1698 ++pch->ppp->dev->stats.rx_length_errors;
1699 ppp_receive_error(pch->ppp);
1700 }
1701 goto done;
1702 }
1703
1704 proto = PPP_PROTO(skb);
1705 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1706 /* put it on the channel queue */
1707 skb_queue_tail(&pch->file.rq, skb);
1708 /* drop old frames if queue too long */
1709 while (pch->file.rq.qlen > PPP_MAX_RQLEN &&
1710 (skb = skb_dequeue(&pch->file.rq)))
1711 kfree_skb(skb);
1712 wake_up_interruptible(&pch->file.rwait);
1713 } else {
1714 ppp_do_recv(pch->ppp, skb, pch);
1715 }
1716
1717 done:
1718 read_unlock_bh(&pch->upl);
1719 }
1720
1721 /* Put a 0-length skb in the receive queue as an error indication */
1722 void
1723 ppp_input_error(struct ppp_channel *chan, int code)
1724 {
1725 struct channel *pch = chan->ppp;
1726 struct sk_buff *skb;
1727
1728 if (!pch)
1729 return;
1730
1731 read_lock_bh(&pch->upl);
1732 if (pch->ppp) {
1733 skb = alloc_skb(0, GFP_ATOMIC);
1734 if (skb) {
1735 skb->len = 0; /* probably unnecessary */
1736 skb->cb[0] = code;
1737 ppp_do_recv(pch->ppp, skb, pch);
1738 }
1739 }
1740 read_unlock_bh(&pch->upl);
1741 }
1742
1743 /*
1744 * We come in here to process a received frame.
1745 * The receive side of the ppp unit is locked.
1746 */
1747 static void
1748 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1749 {
1750 /* note: a 0-length skb is used as an error indication */
1751 if (skb->len > 0) {
1752 skb_checksum_complete_unset(skb);
1753 #ifdef CONFIG_PPP_MULTILINK
1754 /* XXX do channel-level decompression here */
1755 if (PPP_PROTO(skb) == PPP_MP)
1756 ppp_receive_mp_frame(ppp, skb, pch);
1757 else
1758 #endif /* CONFIG_PPP_MULTILINK */
1759 ppp_receive_nonmp_frame(ppp, skb);
1760 } else {
1761 kfree_skb(skb);
1762 ppp_receive_error(ppp);
1763 }
1764 }
1765
1766 static void
1767 ppp_receive_error(struct ppp *ppp)
1768 {
1769 ++ppp->dev->stats.rx_errors;
1770 if (ppp->vj)
1771 slhc_toss(ppp->vj);
1772 }
1773
1774 static void
1775 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1776 {
1777 struct sk_buff *ns;
1778 int proto, len, npi;
1779
1780 /*
1781 * Decompress the frame, if compressed.
1782 * Note that some decompressors need to see uncompressed frames
1783 * that come in as well as compressed frames.
1784 */
1785 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) &&
1786 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1787 skb = ppp_decompress_frame(ppp, skb);
1788
1789 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1790 goto err;
1791
1792 proto = PPP_PROTO(skb);
1793 switch (proto) {
1794 case PPP_VJC_COMP:
1795 /* decompress VJ compressed packets */
1796 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1797 goto err;
1798
1799 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1800 /* copy to a new sk_buff with more tailroom */
1801 ns = dev_alloc_skb(skb->len + 128);
1802 if (!ns) {
1803 netdev_err(ppp->dev, "PPP: no memory "
1804 "(VJ decomp)\n");
1805 goto err;
1806 }
1807 skb_reserve(ns, 2);
1808 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1809 consume_skb(skb);
1810 skb = ns;
1811 }
1812 else
1813 skb->ip_summed = CHECKSUM_NONE;
1814
1815 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1816 if (len <= 0) {
1817 netdev_printk(KERN_DEBUG, ppp->dev,
1818 "PPP: VJ decompression error\n");
1819 goto err;
1820 }
1821 len += 2;
1822 if (len > skb->len)
1823 skb_put(skb, len - skb->len);
1824 else if (len < skb->len)
1825 skb_trim(skb, len);
1826 proto = PPP_IP;
1827 break;
1828
1829 case PPP_VJC_UNCOMP:
1830 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1831 goto err;
1832
1833 /* Until we fix the decompressor need to make sure
1834 * data portion is linear.
1835 */
1836 if (!pskb_may_pull(skb, skb->len))
1837 goto err;
1838
1839 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1840 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n");
1841 goto err;
1842 }
1843 proto = PPP_IP;
1844 break;
1845
1846 case PPP_CCP:
1847 ppp_ccp_peek(ppp, skb, 1);
1848 break;
1849 }
1850
1851 ++ppp->stats64.rx_packets;
1852 ppp->stats64.rx_bytes += skb->len - 2;
1853
1854 npi = proto_to_npindex(proto);
1855 if (npi < 0) {
1856 /* control or unknown frame - pass it to pppd */
1857 skb_queue_tail(&ppp->file.rq, skb);
1858 /* limit queue length by dropping old frames */
1859 while (ppp->file.rq.qlen > PPP_MAX_RQLEN &&
1860 (skb = skb_dequeue(&ppp->file.rq)))
1861 kfree_skb(skb);
1862 /* wake up any process polling or blocking on read */
1863 wake_up_interruptible(&ppp->file.rwait);
1864
1865 } else {
1866 /* network protocol frame - give it to the kernel */
1867
1868 #ifdef CONFIG_PPP_FILTER
1869 /* check if the packet passes the pass and active filters */
1870 /* the filter instructions are constructed assuming
1871 a four-byte PPP header on each packet */
1872 if (ppp->pass_filter || ppp->active_filter) {
1873 if (skb_unclone(skb, GFP_ATOMIC))
1874 goto err;
1875
1876 *skb_push(skb, 2) = 0;
1877 if (ppp->pass_filter &&
1878 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
1879 if (ppp->debug & 1)
1880 netdev_printk(KERN_DEBUG, ppp->dev,
1881 "PPP: inbound frame "
1882 "not passed\n");
1883 kfree_skb(skb);
1884 return;
1885 }
1886 if (!(ppp->active_filter &&
1887 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
1888 ppp->last_recv = jiffies;
1889 __skb_pull(skb, 2);
1890 } else
1891 #endif /* CONFIG_PPP_FILTER */
1892 ppp->last_recv = jiffies;
1893
1894 if ((ppp->dev->flags & IFF_UP) == 0 ||
1895 ppp->npmode[npi] != NPMODE_PASS) {
1896 kfree_skb(skb);
1897 } else {
1898 /* chop off protocol */
1899 skb_pull_rcsum(skb, 2);
1900 skb->dev = ppp->dev;
1901 skb->protocol = htons(npindex_to_ethertype[npi]);
1902 skb_reset_mac_header(skb);
1903 netif_rx(skb);
1904 }
1905 }
1906 return;
1907
1908 err:
1909 kfree_skb(skb);
1910 ppp_receive_error(ppp);
1911 }
1912
1913 static struct sk_buff *
1914 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1915 {
1916 int proto = PPP_PROTO(skb);
1917 struct sk_buff *ns;
1918 int len;
1919
1920 /* Until we fix all the decompressor's need to make sure
1921 * data portion is linear.
1922 */
1923 if (!pskb_may_pull(skb, skb->len))
1924 goto err;
1925
1926 if (proto == PPP_COMP) {
1927 int obuff_size;
1928
1929 switch(ppp->rcomp->compress_proto) {
1930 case CI_MPPE:
1931 obuff_size = ppp->mru + PPP_HDRLEN + 1;
1932 break;
1933 default:
1934 obuff_size = ppp->mru + PPP_HDRLEN;
1935 break;
1936 }
1937
1938 ns = dev_alloc_skb(obuff_size);
1939 if (!ns) {
1940 netdev_err(ppp->dev, "ppp_decompress_frame: "
1941 "no memory\n");
1942 goto err;
1943 }
1944 /* the decompressor still expects the A/C bytes in the hdr */
1945 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1946 skb->len + 2, ns->data, obuff_size);
1947 if (len < 0) {
1948 /* Pass the compressed frame to pppd as an
1949 error indication. */
1950 if (len == DECOMP_FATALERROR)
1951 ppp->rstate |= SC_DC_FERROR;
1952 kfree_skb(ns);
1953 goto err;
1954 }
1955
1956 consume_skb(skb);
1957 skb = ns;
1958 skb_put(skb, len);
1959 skb_pull(skb, 2); /* pull off the A/C bytes */
1960
1961 } else {
1962 /* Uncompressed frame - pass to decompressor so it
1963 can update its dictionary if necessary. */
1964 if (ppp->rcomp->incomp)
1965 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1966 skb->len + 2);
1967 }
1968
1969 return skb;
1970
1971 err:
1972 ppp->rstate |= SC_DC_ERROR;
1973 ppp_receive_error(ppp);
1974 return skb;
1975 }
1976
1977 #ifdef CONFIG_PPP_MULTILINK
1978 /*
1979 * Receive a multilink frame.
1980 * We put it on the reconstruction queue and then pull off
1981 * as many completed frames as we can.
1982 */
1983 static void
1984 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1985 {
1986 u32 mask, seq;
1987 struct channel *ch;
1988 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1989
1990 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
1991 goto err; /* no good, throw it away */
1992
1993 /* Decode sequence number and begin/end bits */
1994 if (ppp->flags & SC_MP_SHORTSEQ) {
1995 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1996 mask = 0xfff;
1997 } else {
1998 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1999 mask = 0xffffff;
2000 }
2001 PPP_MP_CB(skb)->BEbits = skb->data[2];
2002 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
2003
2004 /*
2005 * Do protocol ID decompression on the first fragment of each packet.
2006 */
2007 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1))
2008 *skb_push(skb, 1) = 0;
2009
2010 /*
2011 * Expand sequence number to 32 bits, making it as close
2012 * as possible to ppp->minseq.
2013 */
2014 seq |= ppp->minseq & ~mask;
2015 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
2016 seq += mask + 1;
2017 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
2018 seq -= mask + 1; /* should never happen */
2019 PPP_MP_CB(skb)->sequence = seq;
2020 pch->lastseq = seq;
2021
2022 /*
2023 * If this packet comes before the next one we were expecting,
2024 * drop it.
2025 */
2026 if (seq_before(seq, ppp->nextseq)) {
2027 kfree_skb(skb);
2028 ++ppp->dev->stats.rx_dropped;
2029 ppp_receive_error(ppp);
2030 return;
2031 }
2032
2033 /*
2034 * Reevaluate minseq, the minimum over all channels of the
2035 * last sequence number received on each channel. Because of
2036 * the increasing sequence number rule, we know that any fragment
2037 * before `minseq' which hasn't arrived is never going to arrive.
2038 * The list of channels can't change because we have the receive
2039 * side of the ppp unit locked.
2040 */
2041 list_for_each_entry(ch, &ppp->channels, clist) {
2042 if (seq_before(ch->lastseq, seq))
2043 seq = ch->lastseq;
2044 }
2045 if (seq_before(ppp->minseq, seq))
2046 ppp->minseq = seq;
2047
2048 /* Put the fragment on the reconstruction queue */
2049 ppp_mp_insert(ppp, skb);
2050
2051 /* If the queue is getting long, don't wait any longer for packets
2052 before the start of the queue. */
2053 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
2054 struct sk_buff *mskb = skb_peek(&ppp->mrq);
2055 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence))
2056 ppp->minseq = PPP_MP_CB(mskb)->sequence;
2057 }
2058
2059 /* Pull completed packets off the queue and receive them. */
2060 while ((skb = ppp_mp_reconstruct(ppp))) {
2061 if (pskb_may_pull(skb, 2))
2062 ppp_receive_nonmp_frame(ppp, skb);
2063 else {
2064 ++ppp->dev->stats.rx_length_errors;
2065 kfree_skb(skb);
2066 ppp_receive_error(ppp);
2067 }
2068 }
2069
2070 return;
2071
2072 err:
2073 kfree_skb(skb);
2074 ppp_receive_error(ppp);
2075 }
2076
2077 /*
2078 * Insert a fragment on the MP reconstruction queue.
2079 * The queue is ordered by increasing sequence number.
2080 */
2081 static void
2082 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
2083 {
2084 struct sk_buff *p;
2085 struct sk_buff_head *list = &ppp->mrq;
2086 u32 seq = PPP_MP_CB(skb)->sequence;
2087
2088 /* N.B. we don't need to lock the list lock because we have the
2089 ppp unit receive-side lock. */
2090 skb_queue_walk(list, p) {
2091 if (seq_before(seq, PPP_MP_CB(p)->sequence))
2092 break;
2093 }
2094 __skb_queue_before(list, p, skb);
2095 }
2096
2097 /*
2098 * Reconstruct a packet from the MP fragment queue.
2099 * We go through increasing sequence numbers until we find a
2100 * complete packet, or we get to the sequence number for a fragment
2101 * which hasn't arrived but might still do so.
2102 */
2103 static struct sk_buff *
2104 ppp_mp_reconstruct(struct ppp *ppp)
2105 {
2106 u32 seq = ppp->nextseq;
2107 u32 minseq = ppp->minseq;
2108 struct sk_buff_head *list = &ppp->mrq;
2109 struct sk_buff *p, *tmp;
2110 struct sk_buff *head, *tail;
2111 struct sk_buff *skb = NULL;
2112 int lost = 0, len = 0;
2113
2114 if (ppp->mrru == 0) /* do nothing until mrru is set */
2115 return NULL;
2116 head = list->next;
2117 tail = NULL;
2118 skb_queue_walk_safe(list, p, tmp) {
2119 again:
2120 if (seq_before(PPP_MP_CB(p)->sequence, seq)) {
2121 /* this can't happen, anyway ignore the skb */
2122 netdev_err(ppp->dev, "ppp_mp_reconstruct bad "
2123 "seq %u < %u\n",
2124 PPP_MP_CB(p)->sequence, seq);
2125 __skb_unlink(p, list);
2126 kfree_skb(p);
2127 continue;
2128 }
2129 if (PPP_MP_CB(p)->sequence != seq) {
2130 u32 oldseq;
2131 /* Fragment `seq' is missing. If it is after
2132 minseq, it might arrive later, so stop here. */
2133 if (seq_after(seq, minseq))
2134 break;
2135 /* Fragment `seq' is lost, keep going. */
2136 lost = 1;
2137 oldseq = seq;
2138 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)?
2139 minseq + 1: PPP_MP_CB(p)->sequence;
2140
2141 if (ppp->debug & 1)
2142 netdev_printk(KERN_DEBUG, ppp->dev,
2143 "lost frag %u..%u\n",
2144 oldseq, seq-1);
2145
2146 goto again;
2147 }
2148
2149 /*
2150 * At this point we know that all the fragments from
2151 * ppp->nextseq to seq are either present or lost.
2152 * Also, there are no complete packets in the queue
2153 * that have no missing fragments and end before this
2154 * fragment.
2155 */
2156
2157 /* B bit set indicates this fragment starts a packet */
2158 if (PPP_MP_CB(p)->BEbits & B) {
2159 head = p;
2160 lost = 0;
2161 len = 0;
2162 }
2163
2164 len += p->len;
2165
2166 /* Got a complete packet yet? */
2167 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) &&
2168 (PPP_MP_CB(head)->BEbits & B)) {
2169 if (len > ppp->mrru + 2) {
2170 ++ppp->dev->stats.rx_length_errors;
2171 netdev_printk(KERN_DEBUG, ppp->dev,
2172 "PPP: reconstructed packet"
2173 " is too long (%d)\n", len);
2174 } else {
2175 tail = p;
2176 break;
2177 }
2178 ppp->nextseq = seq + 1;
2179 }
2180
2181 /*
2182 * If this is the ending fragment of a packet,
2183 * and we haven't found a complete valid packet yet,
2184 * we can discard up to and including this fragment.
2185 */
2186 if (PPP_MP_CB(p)->BEbits & E) {
2187 struct sk_buff *tmp2;
2188
2189 skb_queue_reverse_walk_from_safe(list, p, tmp2) {
2190 if (ppp->debug & 1)
2191 netdev_printk(KERN_DEBUG, ppp->dev,
2192 "discarding frag %u\n",
2193 PPP_MP_CB(p)->sequence);
2194 __skb_unlink(p, list);
2195 kfree_skb(p);
2196 }
2197 head = skb_peek(list);
2198 if (!head)
2199 break;
2200 }
2201 ++seq;
2202 }
2203
2204 /* If we have a complete packet, copy it all into one skb. */
2205 if (tail != NULL) {
2206 /* If we have discarded any fragments,
2207 signal a receive error. */
2208 if (PPP_MP_CB(head)->sequence != ppp->nextseq) {
2209 skb_queue_walk_safe(list, p, tmp) {
2210 if (p == head)
2211 break;
2212 if (ppp->debug & 1)
2213 netdev_printk(KERN_DEBUG, ppp->dev,
2214 "discarding frag %u\n",
2215 PPP_MP_CB(p)->sequence);
2216 __skb_unlink(p, list);
2217 kfree_skb(p);
2218 }
2219
2220 if (ppp->debug & 1)
2221 netdev_printk(KERN_DEBUG, ppp->dev,
2222 " missed pkts %u..%u\n",
2223 ppp->nextseq,
2224 PPP_MP_CB(head)->sequence-1);
2225 ++ppp->dev->stats.rx_dropped;
2226 ppp_receive_error(ppp);
2227 }
2228
2229 skb = head;
2230 if (head != tail) {
2231 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list;
2232 p = skb_queue_next(list, head);
2233 __skb_unlink(skb, list);
2234 skb_queue_walk_from_safe(list, p, tmp) {
2235 __skb_unlink(p, list);
2236 *fragpp = p;
2237 p->next = NULL;
2238 fragpp = &p->next;
2239
2240 skb->len += p->len;
2241 skb->data_len += p->len;
2242 skb->truesize += p->truesize;
2243
2244 if (p == tail)
2245 break;
2246 }
2247 } else {
2248 __skb_unlink(skb, list);
2249 }
2250
2251 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1;
2252 }
2253
2254 return skb;
2255 }
2256 #endif /* CONFIG_PPP_MULTILINK */
2257
2258 /*
2259 * Channel interface.
2260 */
2261
2262 /* Create a new, unattached ppp channel. */
2263 int ppp_register_channel(struct ppp_channel *chan)
2264 {
2265 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2266 }
2267
2268 /* Create a new, unattached ppp channel for specified net. */
2269 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
2270 {
2271 struct channel *pch;
2272 struct ppp_net *pn;
2273
2274 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2275 if (!pch)
2276 return -ENOMEM;
2277
2278 pn = ppp_pernet(net);
2279
2280 pch->ppp = NULL;
2281 pch->chan = chan;
2282 pch->chan_net = net;
2283 chan->ppp = pch;
2284 init_ppp_file(&pch->file, CHANNEL);
2285 pch->file.hdrlen = chan->hdrlen;
2286 #ifdef CONFIG_PPP_MULTILINK
2287 pch->lastseq = -1;
2288 #endif /* CONFIG_PPP_MULTILINK */
2289 init_rwsem(&pch->chan_sem);
2290 spin_lock_init(&pch->downl);
2291 rwlock_init(&pch->upl);
2292
2293 spin_lock_bh(&pn->all_channels_lock);
2294 pch->file.index = ++pn->last_channel_index;
2295 list_add(&pch->list, &pn->new_channels);
2296 atomic_inc(&channel_count);
2297 spin_unlock_bh(&pn->all_channels_lock);
2298
2299 return 0;
2300 }
2301
2302 /*
2303 * Return the index of a channel.
2304 */
2305 int ppp_channel_index(struct ppp_channel *chan)
2306 {
2307 struct channel *pch = chan->ppp;
2308
2309 if (pch)
2310 return pch->file.index;
2311 return -1;
2312 }
2313
2314 /*
2315 * Return the PPP unit number to which a channel is connected.
2316 */
2317 int ppp_unit_number(struct ppp_channel *chan)
2318 {
2319 struct channel *pch = chan->ppp;
2320 int unit = -1;
2321
2322 if (pch) {
2323 read_lock_bh(&pch->upl);
2324 if (pch->ppp)
2325 unit = pch->ppp->file.index;
2326 read_unlock_bh(&pch->upl);
2327 }
2328 return unit;
2329 }
2330
2331 /*
2332 * Return the PPP device interface name of a channel.
2333 */
2334 char *ppp_dev_name(struct ppp_channel *chan)
2335 {
2336 struct channel *pch = chan->ppp;
2337 char *name = NULL;
2338
2339 if (pch) {
2340 read_lock_bh(&pch->upl);
2341 if (pch->ppp && pch->ppp->dev)
2342 name = pch->ppp->dev->name;
2343 read_unlock_bh(&pch->upl);
2344 }
2345 return name;
2346 }
2347
2348
2349 /*
2350 * Disconnect a channel from the generic layer.
2351 * This must be called in process context.
2352 */
2353 void
2354 ppp_unregister_channel(struct ppp_channel *chan)
2355 {
2356 struct channel *pch = chan->ppp;
2357 struct ppp_net *pn;
2358
2359 if (!pch)
2360 return; /* should never happen */
2361
2362 chan->ppp = NULL;
2363
2364 /*
2365 * This ensures that we have returned from any calls into the
2366 * the channel's start_xmit or ioctl routine before we proceed.
2367 */
2368 down_write(&pch->chan_sem);
2369 spin_lock_bh(&pch->downl);
2370 pch->chan = NULL;
2371 spin_unlock_bh(&pch->downl);
2372 up_write(&pch->chan_sem);
2373 ppp_disconnect_channel(pch);
2374
2375 pn = ppp_pernet(pch->chan_net);
2376 spin_lock_bh(&pn->all_channels_lock);
2377 list_del(&pch->list);
2378 spin_unlock_bh(&pn->all_channels_lock);
2379
2380 pch->file.dead = 1;
2381 wake_up_interruptible(&pch->file.rwait);
2382 if (atomic_dec_and_test(&pch->file.refcnt))
2383 ppp_destroy_channel(pch);
2384 }
2385
2386 /*
2387 * Callback from a channel when it can accept more to transmit.
2388 * This should be called at BH/softirq level, not interrupt level.
2389 */
2390 void
2391 ppp_output_wakeup(struct ppp_channel *chan)
2392 {
2393 struct channel *pch = chan->ppp;
2394
2395 if (!pch)
2396 return;
2397 ppp_channel_push(pch);
2398 }
2399
2400 /*
2401 * Compression control.
2402 */
2403
2404 /* Process the PPPIOCSCOMPRESS ioctl. */
2405 static int
2406 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2407 {
2408 int err;
2409 struct compressor *cp, *ocomp;
2410 struct ppp_option_data data;
2411 void *state, *ostate;
2412 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2413
2414 err = -EFAULT;
2415 if (copy_from_user(&data, (void __user *) arg, sizeof(data)) ||
2416 (data.length <= CCP_MAX_OPTION_LENGTH &&
2417 copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2418 goto out;
2419 err = -EINVAL;
2420 if (data.length > CCP_MAX_OPTION_LENGTH ||
2421 ccp_option[1] < 2 || ccp_option[1] > data.length)
2422 goto out;
2423
2424 cp = try_then_request_module(
2425 find_compressor(ccp_option[0]),
2426 "ppp-compress-%d", ccp_option[0]);
2427 if (!cp)
2428 goto out;
2429
2430 err = -ENOBUFS;
2431 if (data.transmit) {
2432 state = cp->comp_alloc(ccp_option, data.length);
2433 if (state) {
2434 ppp_xmit_lock(ppp);
2435 ppp->xstate &= ~SC_COMP_RUN;
2436 ocomp = ppp->xcomp;
2437 ostate = ppp->xc_state;
2438 ppp->xcomp = cp;
2439 ppp->xc_state = state;
2440 ppp_xmit_unlock(ppp);
2441 if (ostate) {
2442 ocomp->comp_free(ostate);
2443 module_put(ocomp->owner);
2444 }
2445 err = 0;
2446 } else
2447 module_put(cp->owner);
2448
2449 } else {
2450 state = cp->decomp_alloc(ccp_option, data.length);
2451 if (state) {
2452 ppp_recv_lock(ppp);
2453 ppp->rstate &= ~SC_DECOMP_RUN;
2454 ocomp = ppp->rcomp;
2455 ostate = ppp->rc_state;
2456 ppp->rcomp = cp;
2457 ppp->rc_state = state;
2458 ppp_recv_unlock(ppp);
2459 if (ostate) {
2460 ocomp->decomp_free(ostate);
2461 module_put(ocomp->owner);
2462 }
2463 err = 0;
2464 } else
2465 module_put(cp->owner);
2466 }
2467
2468 out:
2469 return err;
2470 }
2471
2472 /*
2473 * Look at a CCP packet and update our state accordingly.
2474 * We assume the caller has the xmit or recv path locked.
2475 */
2476 static void
2477 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2478 {
2479 unsigned char *dp;
2480 int len;
2481
2482 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2483 return; /* no header */
2484 dp = skb->data + 2;
2485
2486 switch (CCP_CODE(dp)) {
2487 case CCP_CONFREQ:
2488
2489 /* A ConfReq starts negotiation of compression
2490 * in one direction of transmission,
2491 * and hence brings it down...but which way?
2492 *
2493 * Remember:
2494 * A ConfReq indicates what the sender would like to receive
2495 */
2496 if(inbound)
2497 /* He is proposing what I should send */
2498 ppp->xstate &= ~SC_COMP_RUN;
2499 else
2500 /* I am proposing to what he should send */
2501 ppp->rstate &= ~SC_DECOMP_RUN;
2502
2503 break;
2504
2505 case CCP_TERMREQ:
2506 case CCP_TERMACK:
2507 /*
2508 * CCP is going down, both directions of transmission
2509 */
2510 ppp->rstate &= ~SC_DECOMP_RUN;
2511 ppp->xstate &= ~SC_COMP_RUN;
2512 break;
2513
2514 case CCP_CONFACK:
2515 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2516 break;
2517 len = CCP_LENGTH(dp);
2518 if (!pskb_may_pull(skb, len + 2))
2519 return; /* too short */
2520 dp += CCP_HDRLEN;
2521 len -= CCP_HDRLEN;
2522 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2523 break;
2524 if (inbound) {
2525 /* we will start receiving compressed packets */
2526 if (!ppp->rc_state)
2527 break;
2528 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2529 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2530 ppp->rstate |= SC_DECOMP_RUN;
2531 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2532 }
2533 } else {
2534 /* we will soon start sending compressed packets */
2535 if (!ppp->xc_state)
2536 break;
2537 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2538 ppp->file.index, 0, ppp->debug))
2539 ppp->xstate |= SC_COMP_RUN;
2540 }
2541 break;
2542
2543 case CCP_RESETACK:
2544 /* reset the [de]compressor */
2545 if ((ppp->flags & SC_CCP_UP) == 0)
2546 break;
2547 if (inbound) {
2548 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2549 ppp->rcomp->decomp_reset(ppp->rc_state);
2550 ppp->rstate &= ~SC_DC_ERROR;
2551 }
2552 } else {
2553 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2554 ppp->xcomp->comp_reset(ppp->xc_state);
2555 }
2556 break;
2557 }
2558 }
2559
2560 /* Free up compression resources. */
2561 static void
2562 ppp_ccp_closed(struct ppp *ppp)
2563 {
2564 void *xstate, *rstate;
2565 struct compressor *xcomp, *rcomp;
2566
2567 ppp_lock(ppp);
2568 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2569 ppp->xstate = 0;
2570 xcomp = ppp->xcomp;
2571 xstate = ppp->xc_state;
2572 ppp->xc_state = NULL;
2573 ppp->rstate = 0;
2574 rcomp = ppp->rcomp;
2575 rstate = ppp->rc_state;
2576 ppp->rc_state = NULL;
2577 ppp_unlock(ppp);
2578
2579 if (xstate) {
2580 xcomp->comp_free(xstate);
2581 module_put(xcomp->owner);
2582 }
2583 if (rstate) {
2584 rcomp->decomp_free(rstate);
2585 module_put(rcomp->owner);
2586 }
2587 }
2588
2589 /* List of compressors. */
2590 static LIST_HEAD(compressor_list);
2591 static DEFINE_SPINLOCK(compressor_list_lock);
2592
2593 struct compressor_entry {
2594 struct list_head list;
2595 struct compressor *comp;
2596 };
2597
2598 static struct compressor_entry *
2599 find_comp_entry(int proto)
2600 {
2601 struct compressor_entry *ce;
2602
2603 list_for_each_entry(ce, &compressor_list, list) {
2604 if (ce->comp->compress_proto == proto)
2605 return ce;
2606 }
2607 return NULL;
2608 }
2609
2610 /* Register a compressor */
2611 int
2612 ppp_register_compressor(struct compressor *cp)
2613 {
2614 struct compressor_entry *ce;
2615 int ret;
2616 spin_lock(&compressor_list_lock);
2617 ret = -EEXIST;
2618 if (find_comp_entry(cp->compress_proto))
2619 goto out;
2620 ret = -ENOMEM;
2621 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2622 if (!ce)
2623 goto out;
2624 ret = 0;
2625 ce->comp = cp;
2626 list_add(&ce->list, &compressor_list);
2627 out:
2628 spin_unlock(&compressor_list_lock);
2629 return ret;
2630 }
2631
2632 /* Unregister a compressor */
2633 void
2634 ppp_unregister_compressor(struct compressor *cp)
2635 {
2636 struct compressor_entry *ce;
2637
2638 spin_lock(&compressor_list_lock);
2639 ce = find_comp_entry(cp->compress_proto);
2640 if (ce && ce->comp == cp) {
2641 list_del(&ce->list);
2642 kfree(ce);
2643 }
2644 spin_unlock(&compressor_list_lock);
2645 }
2646
2647 /* Find a compressor. */
2648 static struct compressor *
2649 find_compressor(int type)
2650 {
2651 struct compressor_entry *ce;
2652 struct compressor *cp = NULL;
2653
2654 spin_lock(&compressor_list_lock);
2655 ce = find_comp_entry(type);
2656 if (ce) {
2657 cp = ce->comp;
2658 if (!try_module_get(cp->owner))
2659 cp = NULL;
2660 }
2661 spin_unlock(&compressor_list_lock);
2662 return cp;
2663 }
2664
2665 /*
2666 * Miscelleneous stuff.
2667 */
2668
2669 static void
2670 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2671 {
2672 struct slcompress *vj = ppp->vj;
2673
2674 memset(st, 0, sizeof(*st));
2675 st->p.ppp_ipackets = ppp->stats64.rx_packets;
2676 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2677 st->p.ppp_ibytes = ppp->stats64.rx_bytes;
2678 st->p.ppp_opackets = ppp->stats64.tx_packets;
2679 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2680 st->p.ppp_obytes = ppp->stats64.tx_bytes;
2681 if (!vj)
2682 return;
2683 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2684 st->vj.vjs_compressed = vj->sls_o_compressed;
2685 st->vj.vjs_searches = vj->sls_o_searches;
2686 st->vj.vjs_misses = vj->sls_o_misses;
2687 st->vj.vjs_errorin = vj->sls_i_error;
2688 st->vj.vjs_tossed = vj->sls_i_tossed;
2689 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2690 st->vj.vjs_compressedin = vj->sls_i_compressed;
2691 }
2692
2693 /*
2694 * Stuff for handling the lists of ppp units and channels
2695 * and for initialization.
2696 */
2697
2698 /*
2699 * Create a new ppp interface unit. Fails if it can't allocate memory
2700 * or if there is already a unit with the requested number.
2701 * unit == -1 means allocate a new number.
2702 */
2703 static struct ppp *ppp_create_interface(struct net *net, int unit,
2704 struct file *file, int *retp)
2705 {
2706 struct ppp *ppp;
2707 struct ppp_net *pn;
2708 struct net_device *dev = NULL;
2709 int ret = -ENOMEM;
2710 int i;
2711
2712 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_UNKNOWN,
2713 ppp_setup);
2714 if (!dev)
2715 goto out1;
2716
2717 pn = ppp_pernet(net);
2718
2719 ppp = netdev_priv(dev);
2720 ppp->dev = dev;
2721 ppp->mru = PPP_MRU;
2722 init_ppp_file(&ppp->file, INTERFACE);
2723 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2724 ppp->owner = file;
2725 for (i = 0; i < NUM_NP; ++i)
2726 ppp->npmode[i] = NPMODE_PASS;
2727 INIT_LIST_HEAD(&ppp->channels);
2728 spin_lock_init(&ppp->rlock);
2729 spin_lock_init(&ppp->wlock);
2730 #ifdef CONFIG_PPP_MULTILINK
2731 ppp->minseq = -1;
2732 skb_queue_head_init(&ppp->mrq);
2733 #endif /* CONFIG_PPP_MULTILINK */
2734 #ifdef CONFIG_PPP_FILTER
2735 ppp->pass_filter = NULL;
2736 ppp->active_filter = NULL;
2737 #endif /* CONFIG_PPP_FILTER */
2738
2739 /*
2740 * drum roll: don't forget to set
2741 * the net device is belong to
2742 */
2743 dev_net_set(dev, net);
2744
2745 mutex_lock(&pn->all_ppp_mutex);
2746
2747 if (unit < 0) {
2748 unit = unit_get(&pn->units_idr, ppp);
2749 if (unit < 0) {
2750 ret = unit;
2751 goto out2;
2752 }
2753 } else {
2754 ret = -EEXIST;
2755 if (unit_find(&pn->units_idr, unit))
2756 goto out2; /* unit already exists */
2757 /*
2758 * if caller need a specified unit number
2759 * lets try to satisfy him, otherwise --
2760 * he should better ask us for new unit number
2761 *
2762 * NOTE: yes I know that returning EEXIST it's not
2763 * fair but at least pppd will ask us to allocate
2764 * new unit in this case so user is happy :)
2765 */
2766 unit = unit_set(&pn->units_idr, ppp, unit);
2767 if (unit < 0)
2768 goto out2;
2769 }
2770
2771 /* Initialize the new ppp unit */
2772 ppp->file.index = unit;
2773 sprintf(dev->name, "ppp%d", unit);
2774
2775 ret = register_netdev(dev);
2776 if (ret != 0) {
2777 unit_put(&pn->units_idr, unit);
2778 netdev_err(ppp->dev, "PPP: couldn't register device %s (%d)\n",
2779 dev->name, ret);
2780 goto out2;
2781 }
2782
2783 ppp->ppp_net = net;
2784
2785 atomic_inc(&ppp_unit_count);
2786 mutex_unlock(&pn->all_ppp_mutex);
2787
2788 *retp = 0;
2789 return ppp;
2790
2791 out2:
2792 mutex_unlock(&pn->all_ppp_mutex);
2793 free_netdev(dev);
2794 out1:
2795 *retp = ret;
2796 return NULL;
2797 }
2798
2799 /*
2800 * Initialize a ppp_file structure.
2801 */
2802 static void
2803 init_ppp_file(struct ppp_file *pf, int kind)
2804 {
2805 pf->kind = kind;
2806 skb_queue_head_init(&pf->xq);
2807 skb_queue_head_init(&pf->rq);
2808 atomic_set(&pf->refcnt, 1);
2809 init_waitqueue_head(&pf->rwait);
2810 }
2811
2812 /*
2813 * Free the memory used by a ppp unit. This is only called once
2814 * there are no channels connected to the unit and no file structs
2815 * that reference the unit.
2816 */
2817 static void ppp_destroy_interface(struct ppp *ppp)
2818 {
2819 atomic_dec(&ppp_unit_count);
2820
2821 if (!ppp->file.dead || ppp->n_channels) {
2822 /* "can't happen" */
2823 netdev_err(ppp->dev, "ppp: destroying ppp struct %p "
2824 "but dead=%d n_channels=%d !\n",
2825 ppp, ppp->file.dead, ppp->n_channels);
2826 return;
2827 }
2828
2829 ppp_ccp_closed(ppp);
2830 if (ppp->vj) {
2831 slhc_free(ppp->vj);
2832 ppp->vj = NULL;
2833 }
2834 skb_queue_purge(&ppp->file.xq);
2835 skb_queue_purge(&ppp->file.rq);
2836 #ifdef CONFIG_PPP_MULTILINK
2837 skb_queue_purge(&ppp->mrq);
2838 #endif /* CONFIG_PPP_MULTILINK */
2839 #ifdef CONFIG_PPP_FILTER
2840 if (ppp->pass_filter) {
2841 bpf_prog_destroy(ppp->pass_filter);
2842 ppp->pass_filter = NULL;
2843 }
2844
2845 if (ppp->active_filter) {
2846 bpf_prog_destroy(ppp->active_filter);
2847 ppp->active_filter = NULL;
2848 }
2849 #endif /* CONFIG_PPP_FILTER */
2850
2851 kfree_skb(ppp->xmit_pending);
2852
2853 free_netdev(ppp->dev);
2854 }
2855
2856 /*
2857 * Locate an existing ppp unit.
2858 * The caller should have locked the all_ppp_mutex.
2859 */
2860 static struct ppp *
2861 ppp_find_unit(struct ppp_net *pn, int unit)
2862 {
2863 return unit_find(&pn->units_idr, unit);
2864 }
2865
2866 /*
2867 * Locate an existing ppp channel.
2868 * The caller should have locked the all_channels_lock.
2869 * First we look in the new_channels list, then in the
2870 * all_channels list. If found in the new_channels list,
2871 * we move it to the all_channels list. This is for speed
2872 * when we have a lot of channels in use.
2873 */
2874 static struct channel *
2875 ppp_find_channel(struct ppp_net *pn, int unit)
2876 {
2877 struct channel *pch;
2878
2879 list_for_each_entry(pch, &pn->new_channels, list) {
2880 if (pch->file.index == unit) {
2881 list_move(&pch->list, &pn->all_channels);
2882 return pch;
2883 }
2884 }
2885
2886 list_for_each_entry(pch, &pn->all_channels, list) {
2887 if (pch->file.index == unit)
2888 return pch;
2889 }
2890
2891 return NULL;
2892 }
2893
2894 /*
2895 * Connect a PPP channel to a PPP interface unit.
2896 */
2897 static int
2898 ppp_connect_channel(struct channel *pch, int unit)
2899 {
2900 struct ppp *ppp;
2901 struct ppp_net *pn;
2902 int ret = -ENXIO;
2903 int hdrlen;
2904
2905 pn = ppp_pernet(pch->chan_net);
2906
2907 mutex_lock(&pn->all_ppp_mutex);
2908 ppp = ppp_find_unit(pn, unit);
2909 if (!ppp)
2910 goto out;
2911 write_lock_bh(&pch->upl);
2912 ret = -EINVAL;
2913 if (pch->ppp)
2914 goto outl;
2915
2916 ppp_lock(ppp);
2917 if (pch->file.hdrlen > ppp->file.hdrlen)
2918 ppp->file.hdrlen = pch->file.hdrlen;
2919 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2920 if (hdrlen > ppp->dev->hard_header_len)
2921 ppp->dev->hard_header_len = hdrlen;
2922 list_add_tail(&pch->clist, &ppp->channels);
2923 ++ppp->n_channels;
2924 pch->ppp = ppp;
2925 atomic_inc(&ppp->file.refcnt);
2926 ppp_unlock(ppp);
2927 ret = 0;
2928
2929 outl:
2930 write_unlock_bh(&pch->upl);
2931 out:
2932 mutex_unlock(&pn->all_ppp_mutex);
2933 return ret;
2934 }
2935
2936 /*
2937 * Disconnect a channel from its ppp unit.
2938 */
2939 static int
2940 ppp_disconnect_channel(struct channel *pch)
2941 {
2942 struct ppp *ppp;
2943 int err = -EINVAL;
2944
2945 write_lock_bh(&pch->upl);
2946 ppp = pch->ppp;
2947 pch->ppp = NULL;
2948 write_unlock_bh(&pch->upl);
2949 if (ppp) {
2950 /* remove it from the ppp unit's list */
2951 ppp_lock(ppp);
2952 list_del(&pch->clist);
2953 if (--ppp->n_channels == 0)
2954 wake_up_interruptible(&ppp->file.rwait);
2955 ppp_unlock(ppp);
2956 if (atomic_dec_and_test(&ppp->file.refcnt))
2957 ppp_destroy_interface(ppp);
2958 err = 0;
2959 }
2960 return err;
2961 }
2962
2963 /*
2964 * Free up the resources used by a ppp channel.
2965 */
2966 static void ppp_destroy_channel(struct channel *pch)
2967 {
2968 atomic_dec(&channel_count);
2969
2970 if (!pch->file.dead) {
2971 /* "can't happen" */
2972 pr_err("ppp: destroying undead channel %p !\n", pch);
2973 return;
2974 }
2975 skb_queue_purge(&pch->file.xq);
2976 skb_queue_purge(&pch->file.rq);
2977 kfree(pch);
2978 }
2979
2980 static void __exit ppp_cleanup(void)
2981 {
2982 /* should never happen */
2983 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2984 pr_err("PPP: removing module but units remain!\n");
2985 unregister_chrdev(PPP_MAJOR, "ppp");
2986 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
2987 class_destroy(ppp_class);
2988 unregister_pernet_device(&ppp_net_ops);
2989 }
2990
2991 /*
2992 * Units handling. Caller must protect concurrent access
2993 * by holding all_ppp_mutex
2994 */
2995
2996 /* associate pointer with specified number */
2997 static int unit_set(struct idr *p, void *ptr, int n)
2998 {
2999 int unit;
3000
3001 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL);
3002 if (unit == -ENOSPC)
3003 unit = -EINVAL;
3004 return unit;
3005 }
3006
3007 /* get new free unit number and associate pointer with it */
3008 static int unit_get(struct idr *p, void *ptr)
3009 {
3010 return idr_alloc(p, ptr, 0, 0, GFP_KERNEL);
3011 }
3012
3013 /* put unit number back to a pool */
3014 static void unit_put(struct idr *p, int n)
3015 {
3016 idr_remove(p, n);
3017 }
3018
3019 /* get pointer associated with the number */
3020 static void *unit_find(struct idr *p, int n)
3021 {
3022 return idr_find(p, n);
3023 }
3024
3025 /* Module/initialization stuff */
3026
3027 module_init(ppp_init);
3028 module_exit(ppp_cleanup);
3029
3030 EXPORT_SYMBOL(ppp_register_net_channel);
3031 EXPORT_SYMBOL(ppp_register_channel);
3032 EXPORT_SYMBOL(ppp_unregister_channel);
3033 EXPORT_SYMBOL(ppp_channel_index);
3034 EXPORT_SYMBOL(ppp_unit_number);
3035 EXPORT_SYMBOL(ppp_dev_name);
3036 EXPORT_SYMBOL(ppp_input);
3037 EXPORT_SYMBOL(ppp_input_error);
3038 EXPORT_SYMBOL(ppp_output_wakeup);
3039 EXPORT_SYMBOL(ppp_register_compressor);
3040 EXPORT_SYMBOL(ppp_unregister_compressor);
3041 MODULE_LICENSE("GPL");
3042 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
3043 MODULE_ALIAS("devname:ppp");
Linux with added FPC-III support