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ARM: pmu: add support for interrupt-affinity property
[linux/fpc-iii.git] / drivers / net / ppp / ppp_generic.c
blobaf034dba9bd62a693ba81dd04479cd11ffc7f10e
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, int *retp);
273 static void init_ppp_file(struct ppp_file *pf, int kind);
274 static void ppp_shutdown_interface(struct ppp *ppp);
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 if (file == ppp->owner)
396 ppp_shutdown_interface(ppp);
397 }
398 if (atomic_dec_and_test(&pf->refcnt)) {
399 switch (pf->kind) {
400 case INTERFACE:
401 ppp_destroy_interface(PF_TO_PPP(pf));
402 break;
403 case CHANNEL:
404 ppp_destroy_channel(PF_TO_CHANNEL(pf));
405 break;
406 }
407 }
408 }
409 return 0;
410 }
411
412 static ssize_t ppp_read(struct file *file, char __user *buf,
413 size_t count, loff_t *ppos)
414 {
415 struct ppp_file *pf = file->private_data;
416 DECLARE_WAITQUEUE(wait, current);
417 ssize_t ret;
418 struct sk_buff *skb = NULL;
419 struct iovec iov;
420 struct iov_iter to;
421
422 ret = count;
423
424 if (!pf)
425 return -ENXIO;
426 add_wait_queue(&pf->rwait, &wait);
427 for (;;) {
428 set_current_state(TASK_INTERRUPTIBLE);
429 skb = skb_dequeue(&pf->rq);
430 if (skb)
431 break;
432 ret = 0;
433 if (pf->dead)
434 break;
435 if (pf->kind == INTERFACE) {
436 /*
437 * Return 0 (EOF) on an interface that has no
438 * channels connected, unless it is looping
439 * network traffic (demand mode).
440 */
441 struct ppp *ppp = PF_TO_PPP(pf);
442 if (ppp->n_channels == 0 &&
443 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
444 break;
445 }
446 ret = -EAGAIN;
447 if (file->f_flags & O_NONBLOCK)
448 break;
449 ret = -ERESTARTSYS;
450 if (signal_pending(current))
451 break;
452 schedule();
453 }
454 set_current_state(TASK_RUNNING);
455 remove_wait_queue(&pf->rwait, &wait);
456
457 if (!skb)
458 goto out;
459
460 ret = -EOVERFLOW;
461 if (skb->len > count)
462 goto outf;
463 ret = -EFAULT;
464 iov.iov_base = buf;
465 iov.iov_len = count;
466 iov_iter_init(&to, READ, &iov, 1, count);
467 if (skb_copy_datagram_iter(skb, 0, &to, skb->len))
468 goto outf;
469 ret = skb->len;
470
471 outf:
472 kfree_skb(skb);
473 out:
474 return ret;
475 }
476
477 static ssize_t ppp_write(struct file *file, const char __user *buf,
478 size_t count, loff_t *ppos)
479 {
480 struct ppp_file *pf = file->private_data;
481 struct sk_buff *skb;
482 ssize_t ret;
483
484 if (!pf)
485 return -ENXIO;
486 ret = -ENOMEM;
487 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
488 if (!skb)
489 goto out;
490 skb_reserve(skb, pf->hdrlen);
491 ret = -EFAULT;
492 if (copy_from_user(skb_put(skb, count), buf, count)) {
493 kfree_skb(skb);
494 goto out;
495 }
496
497 skb_queue_tail(&pf->xq, skb);
498
499 switch (pf->kind) {
500 case INTERFACE:
501 ppp_xmit_process(PF_TO_PPP(pf));
502 break;
503 case CHANNEL:
504 ppp_channel_push(PF_TO_CHANNEL(pf));
505 break;
506 }
507
508 ret = count;
509
510 out:
511 return ret;
512 }
513
514 /* No kernel lock - fine */
515 static unsigned int ppp_poll(struct file *file, poll_table *wait)
516 {
517 struct ppp_file *pf = file->private_data;
518 unsigned int mask;
519
520 if (!pf)
521 return 0;
522 poll_wait(file, &pf->rwait, wait);
523 mask = POLLOUT | POLLWRNORM;
524 if (skb_peek(&pf->rq))
525 mask |= POLLIN | POLLRDNORM;
526 if (pf->dead)
527 mask |= POLLHUP;
528 else if (pf->kind == INTERFACE) {
529 /* see comment in ppp_read */
530 struct ppp *ppp = PF_TO_PPP(pf);
531 if (ppp->n_channels == 0 &&
532 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
533 mask |= POLLIN | POLLRDNORM;
534 }
535
536 return mask;
537 }
538
539 #ifdef CONFIG_PPP_FILTER
540 static int get_filter(void __user *arg, struct sock_filter **p)
541 {
542 struct sock_fprog uprog;
543 struct sock_filter *code = NULL;
544 int len;
545
546 if (copy_from_user(&uprog, arg, sizeof(uprog)))
547 return -EFAULT;
548
549 if (!uprog.len) {
550 *p = NULL;
551 return 0;
552 }
553
554 len = uprog.len * sizeof(struct sock_filter);
555 code = memdup_user(uprog.filter, len);
556 if (IS_ERR(code))
557 return PTR_ERR(code);
558
559 *p = code;
560 return uprog.len;
561 }
562 #endif /* CONFIG_PPP_FILTER */
563
564 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
565 {
566 struct ppp_file *pf = file->private_data;
567 struct ppp *ppp;
568 int err = -EFAULT, val, val2, i;
569 struct ppp_idle idle;
570 struct npioctl npi;
571 int unit, cflags;
572 struct slcompress *vj;
573 void __user *argp = (void __user *)arg;
574 int __user *p = argp;
575
576 if (!pf)
577 return ppp_unattached_ioctl(current->nsproxy->net_ns,
578 pf, file, cmd, arg);
579
580 if (cmd == PPPIOCDETACH) {
581 /*
582 * We have to be careful here... if the file descriptor
583 * has been dup'd, we could have another process in the
584 * middle of a poll using the same file *, so we had
585 * better not free the interface data structures -
586 * instead we fail the ioctl. Even in this case, we
587 * shut down the interface if we are the owner of it.
588 * Actually, we should get rid of PPPIOCDETACH, userland
589 * (i.e. pppd) could achieve the same effect by closing
590 * this fd and reopening /dev/ppp.
591 */
592 err = -EINVAL;
593 mutex_lock(&ppp_mutex);
594 if (pf->kind == INTERFACE) {
595 ppp = PF_TO_PPP(pf);
596 if (file == ppp->owner)
597 ppp_shutdown_interface(ppp);
598 }
599 if (atomic_long_read(&file->f_count) < 2) {
600 ppp_release(NULL, file);
601 err = 0;
602 } else
603 pr_warn("PPPIOCDETACH file->f_count=%ld\n",
604 atomic_long_read(&file->f_count));
605 mutex_unlock(&ppp_mutex);
606 return err;
607 }
608
609 if (pf->kind == CHANNEL) {
610 struct channel *pch;
611 struct ppp_channel *chan;
612
613 mutex_lock(&ppp_mutex);
614 pch = PF_TO_CHANNEL(pf);
615
616 switch (cmd) {
617 case PPPIOCCONNECT:
618 if (get_user(unit, p))
619 break;
620 err = ppp_connect_channel(pch, unit);
621 break;
622
623 case PPPIOCDISCONN:
624 err = ppp_disconnect_channel(pch);
625 break;
626
627 default:
628 down_read(&pch->chan_sem);
629 chan = pch->chan;
630 err = -ENOTTY;
631 if (chan && chan->ops->ioctl)
632 err = chan->ops->ioctl(chan, cmd, arg);
633 up_read(&pch->chan_sem);
634 }
635 mutex_unlock(&ppp_mutex);
636 return err;
637 }
638
639 if (pf->kind != INTERFACE) {
640 /* can't happen */
641 pr_err("PPP: not interface or channel??\n");
642 return -EINVAL;
643 }
644
645 mutex_lock(&ppp_mutex);
646 ppp = PF_TO_PPP(pf);
647 switch (cmd) {
648 case PPPIOCSMRU:
649 if (get_user(val, p))
650 break;
651 ppp->mru = val;
652 err = 0;
653 break;
654
655 case PPPIOCSFLAGS:
656 if (get_user(val, p))
657 break;
658 ppp_lock(ppp);
659 cflags = ppp->flags & ~val;
660 #ifdef CONFIG_PPP_MULTILINK
661 if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK))
662 ppp->nextseq = 0;
663 #endif
664 ppp->flags = val & SC_FLAG_BITS;
665 ppp_unlock(ppp);
666 if (cflags & SC_CCP_OPEN)
667 ppp_ccp_closed(ppp);
668 err = 0;
669 break;
670
671 case PPPIOCGFLAGS:
672 val = ppp->flags | ppp->xstate | ppp->rstate;
673 if (put_user(val, p))
674 break;
675 err = 0;
676 break;
677
678 case PPPIOCSCOMPRESS:
679 err = ppp_set_compress(ppp, arg);
680 break;
681
682 case PPPIOCGUNIT:
683 if (put_user(ppp->file.index, p))
684 break;
685 err = 0;
686 break;
687
688 case PPPIOCSDEBUG:
689 if (get_user(val, p))
690 break;
691 ppp->debug = val;
692 err = 0;
693 break;
694
695 case PPPIOCGDEBUG:
696 if (put_user(ppp->debug, p))
697 break;
698 err = 0;
699 break;
700
701 case PPPIOCGIDLE:
702 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
703 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
704 if (copy_to_user(argp, &idle, sizeof(idle)))
705 break;
706 err = 0;
707 break;
708
709 case PPPIOCSMAXCID:
710 if (get_user(val, p))
711 break;
712 val2 = 15;
713 if ((val >> 16) != 0) {
714 val2 = val >> 16;
715 val &= 0xffff;
716 }
717 vj = slhc_init(val2+1, val+1);
718 if (!vj) {
719 netdev_err(ppp->dev,
720 "PPP: no memory (VJ compressor)\n");
721 err = -ENOMEM;
722 break;
723 }
724 ppp_lock(ppp);
725 if (ppp->vj)
726 slhc_free(ppp->vj);
727 ppp->vj = vj;
728 ppp_unlock(ppp);
729 err = 0;
730 break;
731
732 case PPPIOCGNPMODE:
733 case PPPIOCSNPMODE:
734 if (copy_from_user(&npi, argp, sizeof(npi)))
735 break;
736 err = proto_to_npindex(npi.protocol);
737 if (err < 0)
738 break;
739 i = err;
740 if (cmd == PPPIOCGNPMODE) {
741 err = -EFAULT;
742 npi.mode = ppp->npmode[i];
743 if (copy_to_user(argp, &npi, sizeof(npi)))
744 break;
745 } else {
746 ppp->npmode[i] = npi.mode;
747 /* we may be able to transmit more packets now (??) */
748 netif_wake_queue(ppp->dev);
749 }
750 err = 0;
751 break;
752
753 #ifdef CONFIG_PPP_FILTER
754 case PPPIOCSPASS:
755 {
756 struct sock_filter *code;
757
758 err = get_filter(argp, &code);
759 if (err >= 0) {
760 struct bpf_prog *pass_filter = NULL;
761 struct sock_fprog_kern fprog = {
762 .len = err,
763 .filter = code,
764 };
765
766 err = 0;
767 if (fprog.filter)
768 err = bpf_prog_create(&pass_filter, &fprog);
769 if (!err) {
770 ppp_lock(ppp);
771 if (ppp->pass_filter)
772 bpf_prog_destroy(ppp->pass_filter);
773 ppp->pass_filter = pass_filter;
774 ppp_unlock(ppp);
775 }
776 kfree(code);
777 }
778 break;
779 }
780 case PPPIOCSACTIVE:
781 {
782 struct sock_filter *code;
783
784 err = get_filter(argp, &code);
785 if (err >= 0) {
786 struct bpf_prog *active_filter = NULL;
787 struct sock_fprog_kern fprog = {
788 .len = err,
789 .filter = code,
790 };
791
792 err = 0;
793 if (fprog.filter)
794 err = bpf_prog_create(&active_filter, &fprog);
795 if (!err) {
796 ppp_lock(ppp);
797 if (ppp->active_filter)
798 bpf_prog_destroy(ppp->active_filter);
799 ppp->active_filter = active_filter;
800 ppp_unlock(ppp);
801 }
802 kfree(code);
803 }
804 break;
805 }
806 #endif /* CONFIG_PPP_FILTER */
807
808 #ifdef CONFIG_PPP_MULTILINK
809 case PPPIOCSMRRU:
810 if (get_user(val, p))
811 break;
812 ppp_recv_lock(ppp);
813 ppp->mrru = val;
814 ppp_recv_unlock(ppp);
815 err = 0;
816 break;
817 #endif /* CONFIG_PPP_MULTILINK */
818
819 default:
820 err = -ENOTTY;
821 }
822 mutex_unlock(&ppp_mutex);
823 return err;
824 }
825
826 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
827 struct file *file, unsigned int cmd, unsigned long arg)
828 {
829 int unit, err = -EFAULT;
830 struct ppp *ppp;
831 struct channel *chan;
832 struct ppp_net *pn;
833 int __user *p = (int __user *)arg;
834
835 mutex_lock(&ppp_mutex);
836 switch (cmd) {
837 case PPPIOCNEWUNIT:
838 /* Create a new ppp unit */
839 if (get_user(unit, p))
840 break;
841 ppp = ppp_create_interface(net, unit, &err);
842 if (!ppp)
843 break;
844 file->private_data = &ppp->file;
845 ppp->owner = file;
846 err = -EFAULT;
847 if (put_user(ppp->file.index, p))
848 break;
849 err = 0;
850 break;
851
852 case PPPIOCATTACH:
853 /* Attach to an existing ppp unit */
854 if (get_user(unit, p))
855 break;
856 err = -ENXIO;
857 pn = ppp_pernet(net);
858 mutex_lock(&pn->all_ppp_mutex);
859 ppp = ppp_find_unit(pn, unit);
860 if (ppp) {
861 atomic_inc(&ppp->file.refcnt);
862 file->private_data = &ppp->file;
863 err = 0;
864 }
865 mutex_unlock(&pn->all_ppp_mutex);
866 break;
867
868 case PPPIOCATTCHAN:
869 if (get_user(unit, p))
870 break;
871 err = -ENXIO;
872 pn = ppp_pernet(net);
873 spin_lock_bh(&pn->all_channels_lock);
874 chan = ppp_find_channel(pn, unit);
875 if (chan) {
876 atomic_inc(&chan->file.refcnt);
877 file->private_data = &chan->file;
878 err = 0;
879 }
880 spin_unlock_bh(&pn->all_channels_lock);
881 break;
882
883 default:
884 err = -ENOTTY;
885 }
886 mutex_unlock(&ppp_mutex);
887 return err;
888 }
889
890 static const struct file_operations ppp_device_fops = {
891 .owner = THIS_MODULE,
892 .read = ppp_read,
893 .write = ppp_write,
894 .poll = ppp_poll,
895 .unlocked_ioctl = ppp_ioctl,
896 .open = ppp_open,
897 .release = ppp_release,
898 .llseek = noop_llseek,
899 };
900
901 static __net_init int ppp_init_net(struct net *net)
902 {
903 struct ppp_net *pn = net_generic(net, ppp_net_id);
904
905 idr_init(&pn->units_idr);
906 mutex_init(&pn->all_ppp_mutex);
907
908 INIT_LIST_HEAD(&pn->all_channels);
909 INIT_LIST_HEAD(&pn->new_channels);
910
911 spin_lock_init(&pn->all_channels_lock);
912
913 return 0;
914 }
915
916 static __net_exit void ppp_exit_net(struct net *net)
917 {
918 struct ppp_net *pn = net_generic(net, ppp_net_id);
919
920 idr_destroy(&pn->units_idr);
921 }
922
923 static struct pernet_operations ppp_net_ops = {
924 .init = ppp_init_net,
925 .exit = ppp_exit_net,
926 .id = &ppp_net_id,
927 .size = sizeof(struct ppp_net),
928 };
929
930 #define PPP_MAJOR 108
931
932 /* Called at boot time if ppp is compiled into the kernel,
933 or at module load time (from init_module) if compiled as a module. */
934 static int __init ppp_init(void)
935 {
936 int err;
937
938 pr_info("PPP generic driver version " PPP_VERSION "\n");
939
940 err = register_pernet_device(&ppp_net_ops);
941 if (err) {
942 pr_err("failed to register PPP pernet device (%d)\n", err);
943 goto out;
944 }
945
946 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
947 if (err) {
948 pr_err("failed to register PPP device (%d)\n", err);
949 goto out_net;
950 }
951
952 ppp_class = class_create(THIS_MODULE, "ppp");
953 if (IS_ERR(ppp_class)) {
954 err = PTR_ERR(ppp_class);
955 goto out_chrdev;
956 }
957
958 /* not a big deal if we fail here :-) */
959 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
960
961 return 0;
962
963 out_chrdev:
964 unregister_chrdev(PPP_MAJOR, "ppp");
965 out_net:
966 unregister_pernet_device(&ppp_net_ops);
967 out:
968 return err;
969 }
970
971 /*
972 * Network interface unit routines.
973 */
974 static netdev_tx_t
975 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
976 {
977 struct ppp *ppp = netdev_priv(dev);
978 int npi, proto;
979 unsigned char *pp;
980
981 npi = ethertype_to_npindex(ntohs(skb->protocol));
982 if (npi < 0)
983 goto outf;
984
985 /* Drop, accept or reject the packet */
986 switch (ppp->npmode[npi]) {
987 case NPMODE_PASS:
988 break;
989 case NPMODE_QUEUE:
990 /* it would be nice to have a way to tell the network
991 system to queue this one up for later. */
992 goto outf;
993 case NPMODE_DROP:
994 case NPMODE_ERROR:
995 goto outf;
996 }
997
998 /* Put the 2-byte PPP protocol number on the front,
999 making sure there is room for the address and control fields. */
1000 if (skb_cow_head(skb, PPP_HDRLEN))
1001 goto outf;
1002
1003 pp = skb_push(skb, 2);
1004 proto = npindex_to_proto[npi];
1005 put_unaligned_be16(proto, pp);
1006
1007 skb_queue_tail(&ppp->file.xq, skb);
1008 ppp_xmit_process(ppp);
1009 return NETDEV_TX_OK;
1010
1011 outf:
1012 kfree_skb(skb);
1013 ++dev->stats.tx_dropped;
1014 return NETDEV_TX_OK;
1015 }
1016
1017 static int
1018 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1019 {
1020 struct ppp *ppp = netdev_priv(dev);
1021 int err = -EFAULT;
1022 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
1023 struct ppp_stats stats;
1024 struct ppp_comp_stats cstats;
1025 char *vers;
1026
1027 switch (cmd) {
1028 case SIOCGPPPSTATS:
1029 ppp_get_stats(ppp, &stats);
1030 if (copy_to_user(addr, &stats, sizeof(stats)))
1031 break;
1032 err = 0;
1033 break;
1034
1035 case SIOCGPPPCSTATS:
1036 memset(&cstats, 0, sizeof(cstats));
1037 if (ppp->xc_state)
1038 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
1039 if (ppp->rc_state)
1040 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
1041 if (copy_to_user(addr, &cstats, sizeof(cstats)))
1042 break;
1043 err = 0;
1044 break;
1045
1046 case SIOCGPPPVER:
1047 vers = PPP_VERSION;
1048 if (copy_to_user(addr, vers, strlen(vers) + 1))
1049 break;
1050 err = 0;
1051 break;
1052
1053 default:
1054 err = -EINVAL;
1055 }
1056
1057 return err;
1058 }
1059
1060 static struct rtnl_link_stats64*
1061 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64)
1062 {
1063 struct ppp *ppp = netdev_priv(dev);
1064
1065 ppp_recv_lock(ppp);
1066 stats64->rx_packets = ppp->stats64.rx_packets;
1067 stats64->rx_bytes = ppp->stats64.rx_bytes;
1068 ppp_recv_unlock(ppp);
1069
1070 ppp_xmit_lock(ppp);
1071 stats64->tx_packets = ppp->stats64.tx_packets;
1072 stats64->tx_bytes = ppp->stats64.tx_bytes;
1073 ppp_xmit_unlock(ppp);
1074
1075 stats64->rx_errors = dev->stats.rx_errors;
1076 stats64->tx_errors = dev->stats.tx_errors;
1077 stats64->rx_dropped = dev->stats.rx_dropped;
1078 stats64->tx_dropped = dev->stats.tx_dropped;
1079 stats64->rx_length_errors = dev->stats.rx_length_errors;
1080
1081 return stats64;
1082 }
1083
1084 static struct lock_class_key ppp_tx_busylock;
1085 static int ppp_dev_init(struct net_device *dev)
1086 {
1087 dev->qdisc_tx_busylock = &ppp_tx_busylock;
1088 return 0;
1089 }
1090
1091 static const struct net_device_ops ppp_netdev_ops = {
1092 .ndo_init = ppp_dev_init,
1093 .ndo_start_xmit = ppp_start_xmit,
1094 .ndo_do_ioctl = ppp_net_ioctl,
1095 .ndo_get_stats64 = ppp_get_stats64,
1096 };
1097
1098 static void ppp_setup(struct net_device *dev)
1099 {
1100 dev->netdev_ops = &ppp_netdev_ops;
1101 dev->hard_header_len = PPP_HDRLEN;
1102 dev->mtu = PPP_MRU;
1103 dev->addr_len = 0;
1104 dev->tx_queue_len = 3;
1105 dev->type = ARPHRD_PPP;
1106 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1107 dev->features |= NETIF_F_NETNS_LOCAL;
1108 netif_keep_dst(dev);
1109 }
1110
1111 /*
1112 * Transmit-side routines.
1113 */
1114
1115 /*
1116 * Called to do any work queued up on the transmit side
1117 * that can now be done.
1118 */
1119 static void
1120 ppp_xmit_process(struct ppp *ppp)
1121 {
1122 struct sk_buff *skb;
1123
1124 ppp_xmit_lock(ppp);
1125 if (!ppp->closing) {
1126 ppp_push(ppp);
1127 while (!ppp->xmit_pending &&
1128 (skb = skb_dequeue(&ppp->file.xq)))
1129 ppp_send_frame(ppp, skb);
1130 /* If there's no work left to do, tell the core net
1131 code that we can accept some more. */
1132 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1133 netif_wake_queue(ppp->dev);
1134 else
1135 netif_stop_queue(ppp->dev);
1136 }
1137 ppp_xmit_unlock(ppp);
1138 }
1139
1140 static inline struct sk_buff *
1141 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1142 {
1143 struct sk_buff *new_skb;
1144 int len;
1145 int new_skb_size = ppp->dev->mtu +
1146 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1147 int compressor_skb_size = ppp->dev->mtu +
1148 ppp->xcomp->comp_extra + PPP_HDRLEN;
1149 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1150 if (!new_skb) {
1151 if (net_ratelimit())
1152 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n");
1153 return NULL;
1154 }
1155 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1156 skb_reserve(new_skb,
1157 ppp->dev->hard_header_len - PPP_HDRLEN);
1158
1159 /* compressor still expects A/C bytes in hdr */
1160 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1161 new_skb->data, skb->len + 2,
1162 compressor_skb_size);
1163 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1164 consume_skb(skb);
1165 skb = new_skb;
1166 skb_put(skb, len);
1167 skb_pull(skb, 2); /* pull off A/C bytes */
1168 } else if (len == 0) {
1169 /* didn't compress, or CCP not up yet */
1170 consume_skb(new_skb);
1171 new_skb = skb;
1172 } else {
1173 /*
1174 * (len < 0)
1175 * MPPE requires that we do not send unencrypted
1176 * frames. The compressor will return -1 if we
1177 * should drop the frame. We cannot simply test
1178 * the compress_proto because MPPE and MPPC share
1179 * the same number.
1180 */
1181 if (net_ratelimit())
1182 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n");
1183 kfree_skb(skb);
1184 consume_skb(new_skb);
1185 new_skb = NULL;
1186 }
1187 return new_skb;
1188 }
1189
1190 /*
1191 * Compress and send a frame.
1192 * The caller should have locked the xmit path,
1193 * and xmit_pending should be 0.
1194 */
1195 static void
1196 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1197 {
1198 int proto = PPP_PROTO(skb);
1199 struct sk_buff *new_skb;
1200 int len;
1201 unsigned char *cp;
1202
1203 if (proto < 0x8000) {
1204 #ifdef CONFIG_PPP_FILTER
1205 /* check if we should pass this packet */
1206 /* the filter instructions are constructed assuming
1207 a four-byte PPP header on each packet */
1208 *skb_push(skb, 2) = 1;
1209 if (ppp->pass_filter &&
1210 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
1211 if (ppp->debug & 1)
1212 netdev_printk(KERN_DEBUG, ppp->dev,
1213 "PPP: outbound frame "
1214 "not passed\n");
1215 kfree_skb(skb);
1216 return;
1217 }
1218 /* if this packet passes the active filter, record the time */
1219 if (!(ppp->active_filter &&
1220 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
1221 ppp->last_xmit = jiffies;
1222 skb_pull(skb, 2);
1223 #else
1224 /* for data packets, record the time */
1225 ppp->last_xmit = jiffies;
1226 #endif /* CONFIG_PPP_FILTER */
1227 }
1228
1229 ++ppp->stats64.tx_packets;
1230 ppp->stats64.tx_bytes += skb->len - 2;
1231
1232 switch (proto) {
1233 case PPP_IP:
1234 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1235 break;
1236 /* try to do VJ TCP header compression */
1237 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1238 GFP_ATOMIC);
1239 if (!new_skb) {
1240 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n");
1241 goto drop;
1242 }
1243 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1244 cp = skb->data + 2;
1245 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1246 new_skb->data + 2, &cp,
1247 !(ppp->flags & SC_NO_TCP_CCID));
1248 if (cp == skb->data + 2) {
1249 /* didn't compress */
1250 consume_skb(new_skb);
1251 } else {
1252 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1253 proto = PPP_VJC_COMP;
1254 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1255 } else {
1256 proto = PPP_VJC_UNCOMP;
1257 cp[0] = skb->data[2];
1258 }
1259 consume_skb(skb);
1260 skb = new_skb;
1261 cp = skb_put(skb, len + 2);
1262 cp[0] = 0;
1263 cp[1] = proto;
1264 }
1265 break;
1266
1267 case PPP_CCP:
1268 /* peek at outbound CCP frames */
1269 ppp_ccp_peek(ppp, skb, 0);
1270 break;
1271 }
1272
1273 /* try to do packet compression */
1274 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state &&
1275 proto != PPP_LCP && proto != PPP_CCP) {
1276 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1277 if (net_ratelimit())
1278 netdev_err(ppp->dev,
1279 "ppp: compression required but "
1280 "down - pkt dropped.\n");
1281 goto drop;
1282 }
1283 skb = pad_compress_skb(ppp, skb);
1284 if (!skb)
1285 goto drop;
1286 }
1287
1288 /*
1289 * If we are waiting for traffic (demand dialling),
1290 * queue it up for pppd to receive.
1291 */
1292 if (ppp->flags & SC_LOOP_TRAFFIC) {
1293 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1294 goto drop;
1295 skb_queue_tail(&ppp->file.rq, skb);
1296 wake_up_interruptible(&ppp->file.rwait);
1297 return;
1298 }
1299
1300 ppp->xmit_pending = skb;
1301 ppp_push(ppp);
1302 return;
1303
1304 drop:
1305 kfree_skb(skb);
1306 ++ppp->dev->stats.tx_errors;
1307 }
1308
1309 /*
1310 * Try to send the frame in xmit_pending.
1311 * The caller should have the xmit path locked.
1312 */
1313 static void
1314 ppp_push(struct ppp *ppp)
1315 {
1316 struct list_head *list;
1317 struct channel *pch;
1318 struct sk_buff *skb = ppp->xmit_pending;
1319
1320 if (!skb)
1321 return;
1322
1323 list = &ppp->channels;
1324 if (list_empty(list)) {
1325 /* nowhere to send the packet, just drop it */
1326 ppp->xmit_pending = NULL;
1327 kfree_skb(skb);
1328 return;
1329 }
1330
1331 if ((ppp->flags & SC_MULTILINK) == 0) {
1332 /* not doing multilink: send it down the first channel */
1333 list = list->next;
1334 pch = list_entry(list, struct channel, clist);
1335
1336 spin_lock_bh(&pch->downl);
1337 if (pch->chan) {
1338 if (pch->chan->ops->start_xmit(pch->chan, skb))
1339 ppp->xmit_pending = NULL;
1340 } else {
1341 /* channel got unregistered */
1342 kfree_skb(skb);
1343 ppp->xmit_pending = NULL;
1344 }
1345 spin_unlock_bh(&pch->downl);
1346 return;
1347 }
1348
1349 #ifdef CONFIG_PPP_MULTILINK
1350 /* Multilink: fragment the packet over as many links
1351 as can take the packet at the moment. */
1352 if (!ppp_mp_explode(ppp, skb))
1353 return;
1354 #endif /* CONFIG_PPP_MULTILINK */
1355
1356 ppp->xmit_pending = NULL;
1357 kfree_skb(skb);
1358 }
1359
1360 #ifdef CONFIG_PPP_MULTILINK
1361 static bool mp_protocol_compress __read_mostly = true;
1362 module_param(mp_protocol_compress, bool, S_IRUGO | S_IWUSR);
1363 MODULE_PARM_DESC(mp_protocol_compress,
1364 "compress protocol id in multilink fragments");
1365
1366 /*
1367 * Divide a packet to be transmitted into fragments and
1368 * send them out the individual links.
1369 */
1370 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1371 {
1372 int len, totlen;
1373 int i, bits, hdrlen, mtu;
1374 int flen;
1375 int navail, nfree, nzero;
1376 int nbigger;
1377 int totspeed;
1378 int totfree;
1379 unsigned char *p, *q;
1380 struct list_head *list;
1381 struct channel *pch;
1382 struct sk_buff *frag;
1383 struct ppp_channel *chan;
1384
1385 totspeed = 0; /*total bitrate of the bundle*/
1386 nfree = 0; /* # channels which have no packet already queued */
1387 navail = 0; /* total # of usable channels (not deregistered) */
1388 nzero = 0; /* number of channels with zero speed associated*/
1389 totfree = 0; /*total # of channels available and
1390 *having no queued packets before
1391 *starting the fragmentation*/
1392
1393 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1394 i = 0;
1395 list_for_each_entry(pch, &ppp->channels, clist) {
1396 if (pch->chan) {
1397 pch->avail = 1;
1398 navail++;
1399 pch->speed = pch->chan->speed;
1400 } else {
1401 pch->avail = 0;
1402 }
1403 if (pch->avail) {
1404 if (skb_queue_empty(&pch->file.xq) ||
1405 !pch->had_frag) {
1406 if (pch->speed == 0)
1407 nzero++;
1408 else
1409 totspeed += pch->speed;
1410
1411 pch->avail = 2;
1412 ++nfree;
1413 ++totfree;
1414 }
1415 if (!pch->had_frag && i < ppp->nxchan)
1416 ppp->nxchan = i;
1417 }
1418 ++i;
1419 }
1420 /*
1421 * Don't start sending this packet unless at least half of
1422 * the channels are free. This gives much better TCP
1423 * performance if we have a lot of channels.
1424 */
1425 if (nfree == 0 || nfree < navail / 2)
1426 return 0; /* can't take now, leave it in xmit_pending */
1427
1428 /* Do protocol field compression */
1429 p = skb->data;
1430 len = skb->len;
1431 if (*p == 0 && mp_protocol_compress) {
1432 ++p;
1433 --len;
1434 }
1435
1436 totlen = len;
1437 nbigger = len % nfree;
1438
1439 /* skip to the channel after the one we last used
1440 and start at that one */
1441 list = &ppp->channels;
1442 for (i = 0; i < ppp->nxchan; ++i) {
1443 list = list->next;
1444 if (list == &ppp->channels) {
1445 i = 0;
1446 break;
1447 }
1448 }
1449
1450 /* create a fragment for each channel */
1451 bits = B;
1452 while (len > 0) {
1453 list = list->next;
1454 if (list == &ppp->channels) {
1455 i = 0;
1456 continue;
1457 }
1458 pch = list_entry(list, struct channel, clist);
1459 ++i;
1460 if (!pch->avail)
1461 continue;
1462
1463 /*
1464 * Skip this channel if it has a fragment pending already and
1465 * we haven't given a fragment to all of the free channels.
1466 */
1467 if (pch->avail == 1) {
1468 if (nfree > 0)
1469 continue;
1470 } else {
1471 pch->avail = 1;
1472 }
1473
1474 /* check the channel's mtu and whether it is still attached. */
1475 spin_lock_bh(&pch->downl);
1476 if (pch->chan == NULL) {
1477 /* can't use this channel, it's being deregistered */
1478 if (pch->speed == 0)
1479 nzero--;
1480 else
1481 totspeed -= pch->speed;
1482
1483 spin_unlock_bh(&pch->downl);
1484 pch->avail = 0;
1485 totlen = len;
1486 totfree--;
1487 nfree--;
1488 if (--navail == 0)
1489 break;
1490 continue;
1491 }
1492
1493 /*
1494 *if the channel speed is not set divide
1495 *the packet evenly among the free channels;
1496 *otherwise divide it according to the speed
1497 *of the channel we are going to transmit on
1498 */
1499 flen = len;
1500 if (nfree > 0) {
1501 if (pch->speed == 0) {
1502 flen = len/nfree;
1503 if (nbigger > 0) {
1504 flen++;
1505 nbigger--;
1506 }
1507 } else {
1508 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
1509 ((totspeed*totfree)/pch->speed)) - hdrlen;
1510 if (nbigger > 0) {
1511 flen += ((totfree - nzero)*pch->speed)/totspeed;
1512 nbigger -= ((totfree - nzero)*pch->speed)/
1513 totspeed;
1514 }
1515 }
1516 nfree--;
1517 }
1518
1519 /*
1520 *check if we are on the last channel or
1521 *we exceded the length of the data to
1522 *fragment
1523 */
1524 if ((nfree <= 0) || (flen > len))
1525 flen = len;
1526 /*
1527 *it is not worth to tx on slow channels:
1528 *in that case from the resulting flen according to the
1529 *above formula will be equal or less than zero.
1530 *Skip the channel in this case
1531 */
1532 if (flen <= 0) {
1533 pch->avail = 2;
1534 spin_unlock_bh(&pch->downl);
1535 continue;
1536 }
1537
1538 /*
1539 * hdrlen includes the 2-byte PPP protocol field, but the
1540 * MTU counts only the payload excluding the protocol field.
1541 * (RFC1661 Section 2)
1542 */
1543 mtu = pch->chan->mtu - (hdrlen - 2);
1544 if (mtu < 4)
1545 mtu = 4;
1546 if (flen > mtu)
1547 flen = mtu;
1548 if (flen == len)
1549 bits |= E;
1550 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1551 if (!frag)
1552 goto noskb;
1553 q = skb_put(frag, flen + hdrlen);
1554
1555 /* make the MP header */
1556 put_unaligned_be16(PPP_MP, q);
1557 if (ppp->flags & SC_MP_XSHORTSEQ) {
1558 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1559 q[3] = ppp->nxseq;
1560 } else {
1561 q[2] = bits;
1562 q[3] = ppp->nxseq >> 16;
1563 q[4] = ppp->nxseq >> 8;
1564 q[5] = ppp->nxseq;
1565 }
1566
1567 memcpy(q + hdrlen, p, flen);
1568
1569 /* try to send it down the channel */
1570 chan = pch->chan;
1571 if (!skb_queue_empty(&pch->file.xq) ||
1572 !chan->ops->start_xmit(chan, frag))
1573 skb_queue_tail(&pch->file.xq, frag);
1574 pch->had_frag = 1;
1575 p += flen;
1576 len -= flen;
1577 ++ppp->nxseq;
1578 bits = 0;
1579 spin_unlock_bh(&pch->downl);
1580 }
1581 ppp->nxchan = i;
1582
1583 return 1;
1584
1585 noskb:
1586 spin_unlock_bh(&pch->downl);
1587 if (ppp->debug & 1)
1588 netdev_err(ppp->dev, "PPP: no memory (fragment)\n");
1589 ++ppp->dev->stats.tx_errors;
1590 ++ppp->nxseq;
1591 return 1; /* abandon the frame */
1592 }
1593 #endif /* CONFIG_PPP_MULTILINK */
1594
1595 /*
1596 * Try to send data out on a channel.
1597 */
1598 static void
1599 ppp_channel_push(struct channel *pch)
1600 {
1601 struct sk_buff *skb;
1602 struct ppp *ppp;
1603
1604 spin_lock_bh(&pch->downl);
1605 if (pch->chan) {
1606 while (!skb_queue_empty(&pch->file.xq)) {
1607 skb = skb_dequeue(&pch->file.xq);
1608 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1609 /* put the packet back and try again later */
1610 skb_queue_head(&pch->file.xq, skb);
1611 break;
1612 }
1613 }
1614 } else {
1615 /* channel got deregistered */
1616 skb_queue_purge(&pch->file.xq);
1617 }
1618 spin_unlock_bh(&pch->downl);
1619 /* see if there is anything from the attached unit to be sent */
1620 if (skb_queue_empty(&pch->file.xq)) {
1621 read_lock_bh(&pch->upl);
1622 ppp = pch->ppp;
1623 if (ppp)
1624 ppp_xmit_process(ppp);
1625 read_unlock_bh(&pch->upl);
1626 }
1627 }
1628
1629 /*
1630 * Receive-side routines.
1631 */
1632
1633 struct ppp_mp_skb_parm {
1634 u32 sequence;
1635 u8 BEbits;
1636 };
1637 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb))
1638
1639 static inline void
1640 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1641 {
1642 ppp_recv_lock(ppp);
1643 if (!ppp->closing)
1644 ppp_receive_frame(ppp, skb, pch);
1645 else
1646 kfree_skb(skb);
1647 ppp_recv_unlock(ppp);
1648 }
1649
1650 void
1651 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1652 {
1653 struct channel *pch = chan->ppp;
1654 int proto;
1655
1656 if (!pch) {
1657 kfree_skb(skb);
1658 return;
1659 }
1660
1661 read_lock_bh(&pch->upl);
1662 if (!pskb_may_pull(skb, 2)) {
1663 kfree_skb(skb);
1664 if (pch->ppp) {
1665 ++pch->ppp->dev->stats.rx_length_errors;
1666 ppp_receive_error(pch->ppp);
1667 }
1668 goto done;
1669 }
1670
1671 proto = PPP_PROTO(skb);
1672 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1673 /* put it on the channel queue */
1674 skb_queue_tail(&pch->file.rq, skb);
1675 /* drop old frames if queue too long */
1676 while (pch->file.rq.qlen > PPP_MAX_RQLEN &&
1677 (skb = skb_dequeue(&pch->file.rq)))
1678 kfree_skb(skb);
1679 wake_up_interruptible(&pch->file.rwait);
1680 } else {
1681 ppp_do_recv(pch->ppp, skb, pch);
1682 }
1683
1684 done:
1685 read_unlock_bh(&pch->upl);
1686 }
1687
1688 /* Put a 0-length skb in the receive queue as an error indication */
1689 void
1690 ppp_input_error(struct ppp_channel *chan, int code)
1691 {
1692 struct channel *pch = chan->ppp;
1693 struct sk_buff *skb;
1694
1695 if (!pch)
1696 return;
1697
1698 read_lock_bh(&pch->upl);
1699 if (pch->ppp) {
1700 skb = alloc_skb(0, GFP_ATOMIC);
1701 if (skb) {
1702 skb->len = 0; /* probably unnecessary */
1703 skb->cb[0] = code;
1704 ppp_do_recv(pch->ppp, skb, pch);
1705 }
1706 }
1707 read_unlock_bh(&pch->upl);
1708 }
1709
1710 /*
1711 * We come in here to process a received frame.
1712 * The receive side of the ppp unit is locked.
1713 */
1714 static void
1715 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1716 {
1717 /* note: a 0-length skb is used as an error indication */
1718 if (skb->len > 0) {
1719 #ifdef CONFIG_PPP_MULTILINK
1720 /* XXX do channel-level decompression here */
1721 if (PPP_PROTO(skb) == PPP_MP)
1722 ppp_receive_mp_frame(ppp, skb, pch);
1723 else
1724 #endif /* CONFIG_PPP_MULTILINK */
1725 ppp_receive_nonmp_frame(ppp, skb);
1726 } else {
1727 kfree_skb(skb);
1728 ppp_receive_error(ppp);
1729 }
1730 }
1731
1732 static void
1733 ppp_receive_error(struct ppp *ppp)
1734 {
1735 ++ppp->dev->stats.rx_errors;
1736 if (ppp->vj)
1737 slhc_toss(ppp->vj);
1738 }
1739
1740 static void
1741 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1742 {
1743 struct sk_buff *ns;
1744 int proto, len, npi;
1745
1746 /*
1747 * Decompress the frame, if compressed.
1748 * Note that some decompressors need to see uncompressed frames
1749 * that come in as well as compressed frames.
1750 */
1751 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) &&
1752 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1753 skb = ppp_decompress_frame(ppp, skb);
1754
1755 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1756 goto err;
1757
1758 proto = PPP_PROTO(skb);
1759 switch (proto) {
1760 case PPP_VJC_COMP:
1761 /* decompress VJ compressed packets */
1762 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1763 goto err;
1764
1765 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1766 /* copy to a new sk_buff with more tailroom */
1767 ns = dev_alloc_skb(skb->len + 128);
1768 if (!ns) {
1769 netdev_err(ppp->dev, "PPP: no memory "
1770 "(VJ decomp)\n");
1771 goto err;
1772 }
1773 skb_reserve(ns, 2);
1774 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1775 consume_skb(skb);
1776 skb = ns;
1777 }
1778 else
1779 skb->ip_summed = CHECKSUM_NONE;
1780
1781 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1782 if (len <= 0) {
1783 netdev_printk(KERN_DEBUG, ppp->dev,
1784 "PPP: VJ decompression error\n");
1785 goto err;
1786 }
1787 len += 2;
1788 if (len > skb->len)
1789 skb_put(skb, len - skb->len);
1790 else if (len < skb->len)
1791 skb_trim(skb, len);
1792 proto = PPP_IP;
1793 break;
1794
1795 case PPP_VJC_UNCOMP:
1796 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1797 goto err;
1798
1799 /* Until we fix the decompressor need to make sure
1800 * data portion is linear.
1801 */
1802 if (!pskb_may_pull(skb, skb->len))
1803 goto err;
1804
1805 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1806 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n");
1807 goto err;
1808 }
1809 proto = PPP_IP;
1810 break;
1811
1812 case PPP_CCP:
1813 ppp_ccp_peek(ppp, skb, 1);
1814 break;
1815 }
1816
1817 ++ppp->stats64.rx_packets;
1818 ppp->stats64.rx_bytes += skb->len - 2;
1819
1820 npi = proto_to_npindex(proto);
1821 if (npi < 0) {
1822 /* control or unknown frame - pass it to pppd */
1823 skb_queue_tail(&ppp->file.rq, skb);
1824 /* limit queue length by dropping old frames */
1825 while (ppp->file.rq.qlen > PPP_MAX_RQLEN &&
1826 (skb = skb_dequeue(&ppp->file.rq)))
1827 kfree_skb(skb);
1828 /* wake up any process polling or blocking on read */
1829 wake_up_interruptible(&ppp->file.rwait);
1830
1831 } else {
1832 /* network protocol frame - give it to the kernel */
1833
1834 #ifdef CONFIG_PPP_FILTER
1835 /* check if the packet passes the pass and active filters */
1836 /* the filter instructions are constructed assuming
1837 a four-byte PPP header on each packet */
1838 if (ppp->pass_filter || ppp->active_filter) {
1839 if (skb_unclone(skb, GFP_ATOMIC))
1840 goto err;
1841
1842 *skb_push(skb, 2) = 0;
1843 if (ppp->pass_filter &&
1844 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
1845 if (ppp->debug & 1)
1846 netdev_printk(KERN_DEBUG, ppp->dev,
1847 "PPP: inbound frame "
1848 "not passed\n");
1849 kfree_skb(skb);
1850 return;
1851 }
1852 if (!(ppp->active_filter &&
1853 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
1854 ppp->last_recv = jiffies;
1855 __skb_pull(skb, 2);
1856 } else
1857 #endif /* CONFIG_PPP_FILTER */
1858 ppp->last_recv = jiffies;
1859
1860 if ((ppp->dev->flags & IFF_UP) == 0 ||
1861 ppp->npmode[npi] != NPMODE_PASS) {
1862 kfree_skb(skb);
1863 } else {
1864 /* chop off protocol */
1865 skb_pull_rcsum(skb, 2);
1866 skb->dev = ppp->dev;
1867 skb->protocol = htons(npindex_to_ethertype[npi]);
1868 skb_reset_mac_header(skb);
1869 netif_rx(skb);
1870 }
1871 }
1872 return;
1873
1874 err:
1875 kfree_skb(skb);
1876 ppp_receive_error(ppp);
1877 }
1878
1879 static struct sk_buff *
1880 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1881 {
1882 int proto = PPP_PROTO(skb);
1883 struct sk_buff *ns;
1884 int len;
1885
1886 /* Until we fix all the decompressor's need to make sure
1887 * data portion is linear.
1888 */
1889 if (!pskb_may_pull(skb, skb->len))
1890 goto err;
1891
1892 if (proto == PPP_COMP) {
1893 int obuff_size;
1894
1895 switch(ppp->rcomp->compress_proto) {
1896 case CI_MPPE:
1897 obuff_size = ppp->mru + PPP_HDRLEN + 1;
1898 break;
1899 default:
1900 obuff_size = ppp->mru + PPP_HDRLEN;
1901 break;
1902 }
1903
1904 ns = dev_alloc_skb(obuff_size);
1905 if (!ns) {
1906 netdev_err(ppp->dev, "ppp_decompress_frame: "
1907 "no memory\n");
1908 goto err;
1909 }
1910 /* the decompressor still expects the A/C bytes in the hdr */
1911 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1912 skb->len + 2, ns->data, obuff_size);
1913 if (len < 0) {
1914 /* Pass the compressed frame to pppd as an
1915 error indication. */
1916 if (len == DECOMP_FATALERROR)
1917 ppp->rstate |= SC_DC_FERROR;
1918 kfree_skb(ns);
1919 goto err;
1920 }
1921
1922 consume_skb(skb);
1923 skb = ns;
1924 skb_put(skb, len);
1925 skb_pull(skb, 2); /* pull off the A/C bytes */
1926
1927 } else {
1928 /* Uncompressed frame - pass to decompressor so it
1929 can update its dictionary if necessary. */
1930 if (ppp->rcomp->incomp)
1931 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1932 skb->len + 2);
1933 }
1934
1935 return skb;
1936
1937 err:
1938 ppp->rstate |= SC_DC_ERROR;
1939 ppp_receive_error(ppp);
1940 return skb;
1941 }
1942
1943 #ifdef CONFIG_PPP_MULTILINK
1944 /*
1945 * Receive a multilink frame.
1946 * We put it on the reconstruction queue and then pull off
1947 * as many completed frames as we can.
1948 */
1949 static void
1950 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1951 {
1952 u32 mask, seq;
1953 struct channel *ch;
1954 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1955
1956 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
1957 goto err; /* no good, throw it away */
1958
1959 /* Decode sequence number and begin/end bits */
1960 if (ppp->flags & SC_MP_SHORTSEQ) {
1961 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1962 mask = 0xfff;
1963 } else {
1964 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1965 mask = 0xffffff;
1966 }
1967 PPP_MP_CB(skb)->BEbits = skb->data[2];
1968 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
1969
1970 /*
1971 * Do protocol ID decompression on the first fragment of each packet.
1972 */
1973 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1))
1974 *skb_push(skb, 1) = 0;
1975
1976 /*
1977 * Expand sequence number to 32 bits, making it as close
1978 * as possible to ppp->minseq.
1979 */
1980 seq |= ppp->minseq & ~mask;
1981 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
1982 seq += mask + 1;
1983 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
1984 seq -= mask + 1; /* should never happen */
1985 PPP_MP_CB(skb)->sequence = seq;
1986 pch->lastseq = seq;
1987
1988 /*
1989 * If this packet comes before the next one we were expecting,
1990 * drop it.
1991 */
1992 if (seq_before(seq, ppp->nextseq)) {
1993 kfree_skb(skb);
1994 ++ppp->dev->stats.rx_dropped;
1995 ppp_receive_error(ppp);
1996 return;
1997 }
1998
1999 /*
2000 * Reevaluate minseq, the minimum over all channels of the
2001 * last sequence number received on each channel. Because of
2002 * the increasing sequence number rule, we know that any fragment
2003 * before `minseq' which hasn't arrived is never going to arrive.
2004 * The list of channels can't change because we have the receive
2005 * side of the ppp unit locked.
2006 */
2007 list_for_each_entry(ch, &ppp->channels, clist) {
2008 if (seq_before(ch->lastseq, seq))
2009 seq = ch->lastseq;
2010 }
2011 if (seq_before(ppp->minseq, seq))
2012 ppp->minseq = seq;
2013
2014 /* Put the fragment on the reconstruction queue */
2015 ppp_mp_insert(ppp, skb);
2016
2017 /* If the queue is getting long, don't wait any longer for packets
2018 before the start of the queue. */
2019 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
2020 struct sk_buff *mskb = skb_peek(&ppp->mrq);
2021 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence))
2022 ppp->minseq = PPP_MP_CB(mskb)->sequence;
2023 }
2024
2025 /* Pull completed packets off the queue and receive them. */
2026 while ((skb = ppp_mp_reconstruct(ppp))) {
2027 if (pskb_may_pull(skb, 2))
2028 ppp_receive_nonmp_frame(ppp, skb);
2029 else {
2030 ++ppp->dev->stats.rx_length_errors;
2031 kfree_skb(skb);
2032 ppp_receive_error(ppp);
2033 }
2034 }
2035
2036 return;
2037
2038 err:
2039 kfree_skb(skb);
2040 ppp_receive_error(ppp);
2041 }
2042
2043 /*
2044 * Insert a fragment on the MP reconstruction queue.
2045 * The queue is ordered by increasing sequence number.
2046 */
2047 static void
2048 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
2049 {
2050 struct sk_buff *p;
2051 struct sk_buff_head *list = &ppp->mrq;
2052 u32 seq = PPP_MP_CB(skb)->sequence;
2053
2054 /* N.B. we don't need to lock the list lock because we have the
2055 ppp unit receive-side lock. */
2056 skb_queue_walk(list, p) {
2057 if (seq_before(seq, PPP_MP_CB(p)->sequence))
2058 break;
2059 }
2060 __skb_queue_before(list, p, skb);
2061 }
2062
2063 /*
2064 * Reconstruct a packet from the MP fragment queue.
2065 * We go through increasing sequence numbers until we find a
2066 * complete packet, or we get to the sequence number for a fragment
2067 * which hasn't arrived but might still do so.
2068 */
2069 static struct sk_buff *
2070 ppp_mp_reconstruct(struct ppp *ppp)
2071 {
2072 u32 seq = ppp->nextseq;
2073 u32 minseq = ppp->minseq;
2074 struct sk_buff_head *list = &ppp->mrq;
2075 struct sk_buff *p, *tmp;
2076 struct sk_buff *head, *tail;
2077 struct sk_buff *skb = NULL;
2078 int lost = 0, len = 0;
2079
2080 if (ppp->mrru == 0) /* do nothing until mrru is set */
2081 return NULL;
2082 head = list->next;
2083 tail = NULL;
2084 skb_queue_walk_safe(list, p, tmp) {
2085 again:
2086 if (seq_before(PPP_MP_CB(p)->sequence, seq)) {
2087 /* this can't happen, anyway ignore the skb */
2088 netdev_err(ppp->dev, "ppp_mp_reconstruct bad "
2089 "seq %u < %u\n",
2090 PPP_MP_CB(p)->sequence, seq);
2091 __skb_unlink(p, list);
2092 kfree_skb(p);
2093 continue;
2094 }
2095 if (PPP_MP_CB(p)->sequence != seq) {
2096 u32 oldseq;
2097 /* Fragment `seq' is missing. If it is after
2098 minseq, it might arrive later, so stop here. */
2099 if (seq_after(seq, minseq))
2100 break;
2101 /* Fragment `seq' is lost, keep going. */
2102 lost = 1;
2103 oldseq = seq;
2104 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)?
2105 minseq + 1: PPP_MP_CB(p)->sequence;
2106
2107 if (ppp->debug & 1)
2108 netdev_printk(KERN_DEBUG, ppp->dev,
2109 "lost frag %u..%u\n",
2110 oldseq, seq-1);
2111
2112 goto again;
2113 }
2114
2115 /*
2116 * At this point we know that all the fragments from
2117 * ppp->nextseq to seq are either present or lost.
2118 * Also, there are no complete packets in the queue
2119 * that have no missing fragments and end before this
2120 * fragment.
2121 */
2122
2123 /* B bit set indicates this fragment starts a packet */
2124 if (PPP_MP_CB(p)->BEbits & B) {
2125 head = p;
2126 lost = 0;
2127 len = 0;
2128 }
2129
2130 len += p->len;
2131
2132 /* Got a complete packet yet? */
2133 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) &&
2134 (PPP_MP_CB(head)->BEbits & B)) {
2135 if (len > ppp->mrru + 2) {
2136 ++ppp->dev->stats.rx_length_errors;
2137 netdev_printk(KERN_DEBUG, ppp->dev,
2138 "PPP: reconstructed packet"
2139 " is too long (%d)\n", len);
2140 } else {
2141 tail = p;
2142 break;
2143 }
2144 ppp->nextseq = seq + 1;
2145 }
2146
2147 /*
2148 * If this is the ending fragment of a packet,
2149 * and we haven't found a complete valid packet yet,
2150 * we can discard up to and including this fragment.
2151 */
2152 if (PPP_MP_CB(p)->BEbits & E) {
2153 struct sk_buff *tmp2;
2154
2155 skb_queue_reverse_walk_from_safe(list, p, tmp2) {
2156 if (ppp->debug & 1)
2157 netdev_printk(KERN_DEBUG, ppp->dev,
2158 "discarding frag %u\n",
2159 PPP_MP_CB(p)->sequence);
2160 __skb_unlink(p, list);
2161 kfree_skb(p);
2162 }
2163 head = skb_peek(list);
2164 if (!head)
2165 break;
2166 }
2167 ++seq;
2168 }
2169
2170 /* If we have a complete packet, copy it all into one skb. */
2171 if (tail != NULL) {
2172 /* If we have discarded any fragments,
2173 signal a receive error. */
2174 if (PPP_MP_CB(head)->sequence != ppp->nextseq) {
2175 skb_queue_walk_safe(list, p, tmp) {
2176 if (p == head)
2177 break;
2178 if (ppp->debug & 1)
2179 netdev_printk(KERN_DEBUG, ppp->dev,
2180 "discarding frag %u\n",
2181 PPP_MP_CB(p)->sequence);
2182 __skb_unlink(p, list);
2183 kfree_skb(p);
2184 }
2185
2186 if (ppp->debug & 1)
2187 netdev_printk(KERN_DEBUG, ppp->dev,
2188 " missed pkts %u..%u\n",
2189 ppp->nextseq,
2190 PPP_MP_CB(head)->sequence-1);
2191 ++ppp->dev->stats.rx_dropped;
2192 ppp_receive_error(ppp);
2193 }
2194
2195 skb = head;
2196 if (head != tail) {
2197 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list;
2198 p = skb_queue_next(list, head);
2199 __skb_unlink(skb, list);
2200 skb_queue_walk_from_safe(list, p, tmp) {
2201 __skb_unlink(p, list);
2202 *fragpp = p;
2203 p->next = NULL;
2204 fragpp = &p->next;
2205
2206 skb->len += p->len;
2207 skb->data_len += p->len;
2208 skb->truesize += p->truesize;
2209
2210 if (p == tail)
2211 break;
2212 }
2213 } else {
2214 __skb_unlink(skb, list);
2215 }
2216
2217 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1;
2218 }
2219
2220 return skb;
2221 }
2222 #endif /* CONFIG_PPP_MULTILINK */
2223
2224 /*
2225 * Channel interface.
2226 */
2227
2228 /* Create a new, unattached ppp channel. */
2229 int ppp_register_channel(struct ppp_channel *chan)
2230 {
2231 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2232 }
2233
2234 /* Create a new, unattached ppp channel for specified net. */
2235 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
2236 {
2237 struct channel *pch;
2238 struct ppp_net *pn;
2239
2240 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2241 if (!pch)
2242 return -ENOMEM;
2243
2244 pn = ppp_pernet(net);
2245
2246 pch->ppp = NULL;
2247 pch->chan = chan;
2248 pch->chan_net = net;
2249 chan->ppp = pch;
2250 init_ppp_file(&pch->file, CHANNEL);
2251 pch->file.hdrlen = chan->hdrlen;
2252 #ifdef CONFIG_PPP_MULTILINK
2253 pch->lastseq = -1;
2254 #endif /* CONFIG_PPP_MULTILINK */
2255 init_rwsem(&pch->chan_sem);
2256 spin_lock_init(&pch->downl);
2257 rwlock_init(&pch->upl);
2258
2259 spin_lock_bh(&pn->all_channels_lock);
2260 pch->file.index = ++pn->last_channel_index;
2261 list_add(&pch->list, &pn->new_channels);
2262 atomic_inc(&channel_count);
2263 spin_unlock_bh(&pn->all_channels_lock);
2264
2265 return 0;
2266 }
2267
2268 /*
2269 * Return the index of a channel.
2270 */
2271 int ppp_channel_index(struct ppp_channel *chan)
2272 {
2273 struct channel *pch = chan->ppp;
2274
2275 if (pch)
2276 return pch->file.index;
2277 return -1;
2278 }
2279
2280 /*
2281 * Return the PPP unit number to which a channel is connected.
2282 */
2283 int ppp_unit_number(struct ppp_channel *chan)
2284 {
2285 struct channel *pch = chan->ppp;
2286 int unit = -1;
2287
2288 if (pch) {
2289 read_lock_bh(&pch->upl);
2290 if (pch->ppp)
2291 unit = pch->ppp->file.index;
2292 read_unlock_bh(&pch->upl);
2293 }
2294 return unit;
2295 }
2296
2297 /*
2298 * Return the PPP device interface name of a channel.
2299 */
2300 char *ppp_dev_name(struct ppp_channel *chan)
2301 {
2302 struct channel *pch = chan->ppp;
2303 char *name = NULL;
2304
2305 if (pch) {
2306 read_lock_bh(&pch->upl);
2307 if (pch->ppp && pch->ppp->dev)
2308 name = pch->ppp->dev->name;
2309 read_unlock_bh(&pch->upl);
2310 }
2311 return name;
2312 }
2313
2314
2315 /*
2316 * Disconnect a channel from the generic layer.
2317 * This must be called in process context.
2318 */
2319 void
2320 ppp_unregister_channel(struct ppp_channel *chan)
2321 {
2322 struct channel *pch = chan->ppp;
2323 struct ppp_net *pn;
2324
2325 if (!pch)
2326 return; /* should never happen */
2327
2328 chan->ppp = NULL;
2329
2330 /*
2331 * This ensures that we have returned from any calls into the
2332 * the channel's start_xmit or ioctl routine before we proceed.
2333 */
2334 down_write(&pch->chan_sem);
2335 spin_lock_bh(&pch->downl);
2336 pch->chan = NULL;
2337 spin_unlock_bh(&pch->downl);
2338 up_write(&pch->chan_sem);
2339 ppp_disconnect_channel(pch);
2340
2341 pn = ppp_pernet(pch->chan_net);
2342 spin_lock_bh(&pn->all_channels_lock);
2343 list_del(&pch->list);
2344 spin_unlock_bh(&pn->all_channels_lock);
2345
2346 pch->file.dead = 1;
2347 wake_up_interruptible(&pch->file.rwait);
2348 if (atomic_dec_and_test(&pch->file.refcnt))
2349 ppp_destroy_channel(pch);
2350 }
2351
2352 /*
2353 * Callback from a channel when it can accept more to transmit.
2354 * This should be called at BH/softirq level, not interrupt level.
2355 */
2356 void
2357 ppp_output_wakeup(struct ppp_channel *chan)
2358 {
2359 struct channel *pch = chan->ppp;
2360
2361 if (!pch)
2362 return;
2363 ppp_channel_push(pch);
2364 }
2365
2366 /*
2367 * Compression control.
2368 */
2369
2370 /* Process the PPPIOCSCOMPRESS ioctl. */
2371 static int
2372 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2373 {
2374 int err;
2375 struct compressor *cp, *ocomp;
2376 struct ppp_option_data data;
2377 void *state, *ostate;
2378 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2379
2380 err = -EFAULT;
2381 if (copy_from_user(&data, (void __user *) arg, sizeof(data)) ||
2382 (data.length <= CCP_MAX_OPTION_LENGTH &&
2383 copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2384 goto out;
2385 err = -EINVAL;
2386 if (data.length > CCP_MAX_OPTION_LENGTH ||
2387 ccp_option[1] < 2 || ccp_option[1] > data.length)
2388 goto out;
2389
2390 cp = try_then_request_module(
2391 find_compressor(ccp_option[0]),
2392 "ppp-compress-%d", ccp_option[0]);
2393 if (!cp)
2394 goto out;
2395
2396 err = -ENOBUFS;
2397 if (data.transmit) {
2398 state = cp->comp_alloc(ccp_option, data.length);
2399 if (state) {
2400 ppp_xmit_lock(ppp);
2401 ppp->xstate &= ~SC_COMP_RUN;
2402 ocomp = ppp->xcomp;
2403 ostate = ppp->xc_state;
2404 ppp->xcomp = cp;
2405 ppp->xc_state = state;
2406 ppp_xmit_unlock(ppp);
2407 if (ostate) {
2408 ocomp->comp_free(ostate);
2409 module_put(ocomp->owner);
2410 }
2411 err = 0;
2412 } else
2413 module_put(cp->owner);
2414
2415 } else {
2416 state = cp->decomp_alloc(ccp_option, data.length);
2417 if (state) {
2418 ppp_recv_lock(ppp);
2419 ppp->rstate &= ~SC_DECOMP_RUN;
2420 ocomp = ppp->rcomp;
2421 ostate = ppp->rc_state;
2422 ppp->rcomp = cp;
2423 ppp->rc_state = state;
2424 ppp_recv_unlock(ppp);
2425 if (ostate) {
2426 ocomp->decomp_free(ostate);
2427 module_put(ocomp->owner);
2428 }
2429 err = 0;
2430 } else
2431 module_put(cp->owner);
2432 }
2433
2434 out:
2435 return err;
2436 }
2437
2438 /*
2439 * Look at a CCP packet and update our state accordingly.
2440 * We assume the caller has the xmit or recv path locked.
2441 */
2442 static void
2443 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2444 {
2445 unsigned char *dp;
2446 int len;
2447
2448 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2449 return; /* no header */
2450 dp = skb->data + 2;
2451
2452 switch (CCP_CODE(dp)) {
2453 case CCP_CONFREQ:
2454
2455 /* A ConfReq starts negotiation of compression
2456 * in one direction of transmission,
2457 * and hence brings it down...but which way?
2458 *
2459 * Remember:
2460 * A ConfReq indicates what the sender would like to receive
2461 */
2462 if(inbound)
2463 /* He is proposing what I should send */
2464 ppp->xstate &= ~SC_COMP_RUN;
2465 else
2466 /* I am proposing to what he should send */
2467 ppp->rstate &= ~SC_DECOMP_RUN;
2468
2469 break;
2470
2471 case CCP_TERMREQ:
2472 case CCP_TERMACK:
2473 /*
2474 * CCP is going down, both directions of transmission
2475 */
2476 ppp->rstate &= ~SC_DECOMP_RUN;
2477 ppp->xstate &= ~SC_COMP_RUN;
2478 break;
2479
2480 case CCP_CONFACK:
2481 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2482 break;
2483 len = CCP_LENGTH(dp);
2484 if (!pskb_may_pull(skb, len + 2))
2485 return; /* too short */
2486 dp += CCP_HDRLEN;
2487 len -= CCP_HDRLEN;
2488 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2489 break;
2490 if (inbound) {
2491 /* we will start receiving compressed packets */
2492 if (!ppp->rc_state)
2493 break;
2494 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2495 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2496 ppp->rstate |= SC_DECOMP_RUN;
2497 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2498 }
2499 } else {
2500 /* we will soon start sending compressed packets */
2501 if (!ppp->xc_state)
2502 break;
2503 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2504 ppp->file.index, 0, ppp->debug))
2505 ppp->xstate |= SC_COMP_RUN;
2506 }
2507 break;
2508
2509 case CCP_RESETACK:
2510 /* reset the [de]compressor */
2511 if ((ppp->flags & SC_CCP_UP) == 0)
2512 break;
2513 if (inbound) {
2514 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2515 ppp->rcomp->decomp_reset(ppp->rc_state);
2516 ppp->rstate &= ~SC_DC_ERROR;
2517 }
2518 } else {
2519 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2520 ppp->xcomp->comp_reset(ppp->xc_state);
2521 }
2522 break;
2523 }
2524 }
2525
2526 /* Free up compression resources. */
2527 static void
2528 ppp_ccp_closed(struct ppp *ppp)
2529 {
2530 void *xstate, *rstate;
2531 struct compressor *xcomp, *rcomp;
2532
2533 ppp_lock(ppp);
2534 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2535 ppp->xstate = 0;
2536 xcomp = ppp->xcomp;
2537 xstate = ppp->xc_state;
2538 ppp->xc_state = NULL;
2539 ppp->rstate = 0;
2540 rcomp = ppp->rcomp;
2541 rstate = ppp->rc_state;
2542 ppp->rc_state = NULL;
2543 ppp_unlock(ppp);
2544
2545 if (xstate) {
2546 xcomp->comp_free(xstate);
2547 module_put(xcomp->owner);
2548 }
2549 if (rstate) {
2550 rcomp->decomp_free(rstate);
2551 module_put(rcomp->owner);
2552 }
2553 }
2554
2555 /* List of compressors. */
2556 static LIST_HEAD(compressor_list);
2557 static DEFINE_SPINLOCK(compressor_list_lock);
2558
2559 struct compressor_entry {
2560 struct list_head list;
2561 struct compressor *comp;
2562 };
2563
2564 static struct compressor_entry *
2565 find_comp_entry(int proto)
2566 {
2567 struct compressor_entry *ce;
2568
2569 list_for_each_entry(ce, &compressor_list, list) {
2570 if (ce->comp->compress_proto == proto)
2571 return ce;
2572 }
2573 return NULL;
2574 }
2575
2576 /* Register a compressor */
2577 int
2578 ppp_register_compressor(struct compressor *cp)
2579 {
2580 struct compressor_entry *ce;
2581 int ret;
2582 spin_lock(&compressor_list_lock);
2583 ret = -EEXIST;
2584 if (find_comp_entry(cp->compress_proto))
2585 goto out;
2586 ret = -ENOMEM;
2587 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2588 if (!ce)
2589 goto out;
2590 ret = 0;
2591 ce->comp = cp;
2592 list_add(&ce->list, &compressor_list);
2593 out:
2594 spin_unlock(&compressor_list_lock);
2595 return ret;
2596 }
2597
2598 /* Unregister a compressor */
2599 void
2600 ppp_unregister_compressor(struct compressor *cp)
2601 {
2602 struct compressor_entry *ce;
2603
2604 spin_lock(&compressor_list_lock);
2605 ce = find_comp_entry(cp->compress_proto);
2606 if (ce && ce->comp == cp) {
2607 list_del(&ce->list);
2608 kfree(ce);
2609 }
2610 spin_unlock(&compressor_list_lock);
2611 }
2612
2613 /* Find a compressor. */
2614 static struct compressor *
2615 find_compressor(int type)
2616 {
2617 struct compressor_entry *ce;
2618 struct compressor *cp = NULL;
2619
2620 spin_lock(&compressor_list_lock);
2621 ce = find_comp_entry(type);
2622 if (ce) {
2623 cp = ce->comp;
2624 if (!try_module_get(cp->owner))
2625 cp = NULL;
2626 }
2627 spin_unlock(&compressor_list_lock);
2628 return cp;
2629 }
2630
2631 /*
2632 * Miscelleneous stuff.
2633 */
2634
2635 static void
2636 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2637 {
2638 struct slcompress *vj = ppp->vj;
2639
2640 memset(st, 0, sizeof(*st));
2641 st->p.ppp_ipackets = ppp->stats64.rx_packets;
2642 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2643 st->p.ppp_ibytes = ppp->stats64.rx_bytes;
2644 st->p.ppp_opackets = ppp->stats64.tx_packets;
2645 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2646 st->p.ppp_obytes = ppp->stats64.tx_bytes;
2647 if (!vj)
2648 return;
2649 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2650 st->vj.vjs_compressed = vj->sls_o_compressed;
2651 st->vj.vjs_searches = vj->sls_o_searches;
2652 st->vj.vjs_misses = vj->sls_o_misses;
2653 st->vj.vjs_errorin = vj->sls_i_error;
2654 st->vj.vjs_tossed = vj->sls_i_tossed;
2655 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2656 st->vj.vjs_compressedin = vj->sls_i_compressed;
2657 }
2658
2659 /*
2660 * Stuff for handling the lists of ppp units and channels
2661 * and for initialization.
2662 */
2663
2664 /*
2665 * Create a new ppp interface unit. Fails if it can't allocate memory
2666 * or if there is already a unit with the requested number.
2667 * unit == -1 means allocate a new number.
2668 */
2669 static struct ppp *
2670 ppp_create_interface(struct net *net, int unit, int *retp)
2671 {
2672 struct ppp *ppp;
2673 struct ppp_net *pn;
2674 struct net_device *dev = NULL;
2675 int ret = -ENOMEM;
2676 int i;
2677
2678 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_UNKNOWN,
2679 ppp_setup);
2680 if (!dev)
2681 goto out1;
2682
2683 pn = ppp_pernet(net);
2684
2685 ppp = netdev_priv(dev);
2686 ppp->dev = dev;
2687 ppp->mru = PPP_MRU;
2688 init_ppp_file(&ppp->file, INTERFACE);
2689 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2690 for (i = 0; i < NUM_NP; ++i)
2691 ppp->npmode[i] = NPMODE_PASS;
2692 INIT_LIST_HEAD(&ppp->channels);
2693 spin_lock_init(&ppp->rlock);
2694 spin_lock_init(&ppp->wlock);
2695 #ifdef CONFIG_PPP_MULTILINK
2696 ppp->minseq = -1;
2697 skb_queue_head_init(&ppp->mrq);
2698 #endif /* CONFIG_PPP_MULTILINK */
2699 #ifdef CONFIG_PPP_FILTER
2700 ppp->pass_filter = NULL;
2701 ppp->active_filter = NULL;
2702 #endif /* CONFIG_PPP_FILTER */
2703
2704 /*
2705 * drum roll: don't forget to set
2706 * the net device is belong to
2707 */
2708 dev_net_set(dev, net);
2709
2710 mutex_lock(&pn->all_ppp_mutex);
2711
2712 if (unit < 0) {
2713 unit = unit_get(&pn->units_idr, ppp);
2714 if (unit < 0) {
2715 ret = unit;
2716 goto out2;
2717 }
2718 } else {
2719 ret = -EEXIST;
2720 if (unit_find(&pn->units_idr, unit))
2721 goto out2; /* unit already exists */
2722 /*
2723 * if caller need a specified unit number
2724 * lets try to satisfy him, otherwise --
2725 * he should better ask us for new unit number
2726 *
2727 * NOTE: yes I know that returning EEXIST it's not
2728 * fair but at least pppd will ask us to allocate
2729 * new unit in this case so user is happy :)
2730 */
2731 unit = unit_set(&pn->units_idr, ppp, unit);
2732 if (unit < 0)
2733 goto out2;
2734 }
2735
2736 /* Initialize the new ppp unit */
2737 ppp->file.index = unit;
2738 sprintf(dev->name, "ppp%d", unit);
2739
2740 ret = register_netdev(dev);
2741 if (ret != 0) {
2742 unit_put(&pn->units_idr, unit);
2743 netdev_err(ppp->dev, "PPP: couldn't register device %s (%d)\n",
2744 dev->name, ret);
2745 goto out2;
2746 }
2747
2748 ppp->ppp_net = net;
2749
2750 atomic_inc(&ppp_unit_count);
2751 mutex_unlock(&pn->all_ppp_mutex);
2752
2753 *retp = 0;
2754 return ppp;
2755
2756 out2:
2757 mutex_unlock(&pn->all_ppp_mutex);
2758 free_netdev(dev);
2759 out1:
2760 *retp = ret;
2761 return NULL;
2762 }
2763
2764 /*
2765 * Initialize a ppp_file structure.
2766 */
2767 static void
2768 init_ppp_file(struct ppp_file *pf, int kind)
2769 {
2770 pf->kind = kind;
2771 skb_queue_head_init(&pf->xq);
2772 skb_queue_head_init(&pf->rq);
2773 atomic_set(&pf->refcnt, 1);
2774 init_waitqueue_head(&pf->rwait);
2775 }
2776
2777 /*
2778 * Take down a ppp interface unit - called when the owning file
2779 * (the one that created the unit) is closed or detached.
2780 */
2781 static void ppp_shutdown_interface(struct ppp *ppp)
2782 {
2783 struct ppp_net *pn;
2784
2785 pn = ppp_pernet(ppp->ppp_net);
2786 mutex_lock(&pn->all_ppp_mutex);
2787
2788 /* This will call dev_close() for us. */
2789 ppp_lock(ppp);
2790 if (!ppp->closing) {
2791 ppp->closing = 1;
2792 ppp_unlock(ppp);
2793 unregister_netdev(ppp->dev);
2794 unit_put(&pn->units_idr, ppp->file.index);
2795 } else
2796 ppp_unlock(ppp);
2797
2798 ppp->file.dead = 1;
2799 ppp->owner = NULL;
2800 wake_up_interruptible(&ppp->file.rwait);
2801
2802 mutex_unlock(&pn->all_ppp_mutex);
2803 }
2804
2805 /*
2806 * Free the memory used by a ppp unit. This is only called once
2807 * there are no channels connected to the unit and no file structs
2808 * that reference the unit.
2809 */
2810 static void ppp_destroy_interface(struct ppp *ppp)
2811 {
2812 atomic_dec(&ppp_unit_count);
2813
2814 if (!ppp->file.dead || ppp->n_channels) {
2815 /* "can't happen" */
2816 netdev_err(ppp->dev, "ppp: destroying ppp struct %p "
2817 "but dead=%d n_channels=%d !\n",
2818 ppp, ppp->file.dead, ppp->n_channels);
2819 return;
2820 }
2821
2822 ppp_ccp_closed(ppp);
2823 if (ppp->vj) {
2824 slhc_free(ppp->vj);
2825 ppp->vj = NULL;
2826 }
2827 skb_queue_purge(&ppp->file.xq);
2828 skb_queue_purge(&ppp->file.rq);
2829 #ifdef CONFIG_PPP_MULTILINK
2830 skb_queue_purge(&ppp->mrq);
2831 #endif /* CONFIG_PPP_MULTILINK */
2832 #ifdef CONFIG_PPP_FILTER
2833 if (ppp->pass_filter) {
2834 bpf_prog_destroy(ppp->pass_filter);
2835 ppp->pass_filter = NULL;
2836 }
2837
2838 if (ppp->active_filter) {
2839 bpf_prog_destroy(ppp->active_filter);
2840 ppp->active_filter = NULL;
2841 }
2842 #endif /* CONFIG_PPP_FILTER */
2843
2844 kfree_skb(ppp->xmit_pending);
2845
2846 free_netdev(ppp->dev);
2847 }
2848
2849 /*
2850 * Locate an existing ppp unit.
2851 * The caller should have locked the all_ppp_mutex.
2852 */
2853 static struct ppp *
2854 ppp_find_unit(struct ppp_net *pn, int unit)
2855 {
2856 return unit_find(&pn->units_idr, unit);
2857 }
2858
2859 /*
2860 * Locate an existing ppp channel.
2861 * The caller should have locked the all_channels_lock.
2862 * First we look in the new_channels list, then in the
2863 * all_channels list. If found in the new_channels list,
2864 * we move it to the all_channels list. This is for speed
2865 * when we have a lot of channels in use.
2866 */
2867 static struct channel *
2868 ppp_find_channel(struct ppp_net *pn, int unit)
2869 {
2870 struct channel *pch;
2871
2872 list_for_each_entry(pch, &pn->new_channels, list) {
2873 if (pch->file.index == unit) {
2874 list_move(&pch->list, &pn->all_channels);
2875 return pch;
2876 }
2877 }
2878
2879 list_for_each_entry(pch, &pn->all_channels, list) {
2880 if (pch->file.index == unit)
2881 return pch;
2882 }
2883
2884 return NULL;
2885 }
2886
2887 /*
2888 * Connect a PPP channel to a PPP interface unit.
2889 */
2890 static int
2891 ppp_connect_channel(struct channel *pch, int unit)
2892 {
2893 struct ppp *ppp;
2894 struct ppp_net *pn;
2895 int ret = -ENXIO;
2896 int hdrlen;
2897
2898 pn = ppp_pernet(pch->chan_net);
2899
2900 mutex_lock(&pn->all_ppp_mutex);
2901 ppp = ppp_find_unit(pn, unit);
2902 if (!ppp)
2903 goto out;
2904 write_lock_bh(&pch->upl);
2905 ret = -EINVAL;
2906 if (pch->ppp)
2907 goto outl;
2908
2909 ppp_lock(ppp);
2910 if (pch->file.hdrlen > ppp->file.hdrlen)
2911 ppp->file.hdrlen = pch->file.hdrlen;
2912 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2913 if (hdrlen > ppp->dev->hard_header_len)
2914 ppp->dev->hard_header_len = hdrlen;
2915 list_add_tail(&pch->clist, &ppp->channels);
2916 ++ppp->n_channels;
2917 pch->ppp = ppp;
2918 atomic_inc(&ppp->file.refcnt);
2919 ppp_unlock(ppp);
2920 ret = 0;
2921
2922 outl:
2923 write_unlock_bh(&pch->upl);
2924 out:
2925 mutex_unlock(&pn->all_ppp_mutex);
2926 return ret;
2927 }
2928
2929 /*
2930 * Disconnect a channel from its ppp unit.
2931 */
2932 static int
2933 ppp_disconnect_channel(struct channel *pch)
2934 {
2935 struct ppp *ppp;
2936 int err = -EINVAL;
2937
2938 write_lock_bh(&pch->upl);
2939 ppp = pch->ppp;
2940 pch->ppp = NULL;
2941 write_unlock_bh(&pch->upl);
2942 if (ppp) {
2943 /* remove it from the ppp unit's list */
2944 ppp_lock(ppp);
2945 list_del(&pch->clist);
2946 if (--ppp->n_channels == 0)
2947 wake_up_interruptible(&ppp->file.rwait);
2948 ppp_unlock(ppp);
2949 if (atomic_dec_and_test(&ppp->file.refcnt))
2950 ppp_destroy_interface(ppp);
2951 err = 0;
2952 }
2953 return err;
2954 }
2955
2956 /*
2957 * Free up the resources used by a ppp channel.
2958 */
2959 static void ppp_destroy_channel(struct channel *pch)
2960 {
2961 atomic_dec(&channel_count);
2962
2963 if (!pch->file.dead) {
2964 /* "can't happen" */
2965 pr_err("ppp: destroying undead channel %p !\n", pch);
2966 return;
2967 }
2968 skb_queue_purge(&pch->file.xq);
2969 skb_queue_purge(&pch->file.rq);
2970 kfree(pch);
2971 }
2972
2973 static void __exit ppp_cleanup(void)
2974 {
2975 /* should never happen */
2976 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2977 pr_err("PPP: removing module but units remain!\n");
2978 unregister_chrdev(PPP_MAJOR, "ppp");
2979 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
2980 class_destroy(ppp_class);
2981 unregister_pernet_device(&ppp_net_ops);
2982 }
2983
2984 /*
2985 * Units handling. Caller must protect concurrent access
2986 * by holding all_ppp_mutex
2987 */
2988
2989 /* associate pointer with specified number */
2990 static int unit_set(struct idr *p, void *ptr, int n)
2991 {
2992 int unit;
2993
2994 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL);
2995 if (unit == -ENOSPC)
2996 unit = -EINVAL;
2997 return unit;
2998 }
2999
3000 /* get new free unit number and associate pointer with it */
3001 static int unit_get(struct idr *p, void *ptr)
3002 {
3003 return idr_alloc(p, ptr, 0, 0, GFP_KERNEL);
3004 }
3005
3006 /* put unit number back to a pool */
3007 static void unit_put(struct idr *p, int n)
3008 {
3009 idr_remove(p, n);
3010 }
3011
3012 /* get pointer associated with the number */
3013 static void *unit_find(struct idr *p, int n)
3014 {
3015 return idr_find(p, n);
3016 }
3017
3018 /* Module/initialization stuff */
3019
3020 module_init(ppp_init);
3021 module_exit(ppp_cleanup);
3022
3023 EXPORT_SYMBOL(ppp_register_net_channel);
3024 EXPORT_SYMBOL(ppp_register_channel);
3025 EXPORT_SYMBOL(ppp_unregister_channel);
3026 EXPORT_SYMBOL(ppp_channel_index);
3027 EXPORT_SYMBOL(ppp_unit_number);
3028 EXPORT_SYMBOL(ppp_dev_name);
3029 EXPORT_SYMBOL(ppp_input);
3030 EXPORT_SYMBOL(ppp_input_error);
3031 EXPORT_SYMBOL(ppp_output_wakeup);
3032 EXPORT_SYMBOL(ppp_register_compressor);
3033 EXPORT_SYMBOL(ppp_unregister_compressor);
3034 MODULE_LICENSE("GPL");
3035 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
3036 MODULE_ALIAS("devname:ppp");
Linux with added FPC-III support