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