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ARM: mm: Recreate kernel mappings in early_paging_init()
[linux/fpc-iii.git] / drivers / net / ppp / ppp_generic.c
blob72ff14b811c621c3a6694a2e4941d2a4c41651ed
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 sock_filter *pass_filter; /* filter for packets to pass */
147 struct sock_filter *active_filter;/* filter for pkts to reset idle */
148 unsigned pass_len, active_len;
149 #endif /* CONFIG_PPP_FILTER */
150 struct net *ppp_net; /* the net we belong to */
151 struct ppp_link_stats stats64; /* 64 bit network stats */
152 };
153
154 /*
155 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
156 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
157 * SC_MUST_COMP
158 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
159 * Bits in xstate: SC_COMP_RUN
160 */
161 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
162 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
163 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
164
165 /*
166 * Private data structure for each channel.
167 * This includes the data structure used for multilink.
168 */
169 struct channel {
170 struct ppp_file file; /* stuff for read/write/poll */
171 struct list_head list; /* link in all/new_channels list */
172 struct ppp_channel *chan; /* public channel data structure */
173 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
174 spinlock_t downl; /* protects `chan', file.xq dequeue */
175 struct ppp *ppp; /* ppp unit we're connected to */
176 struct net *chan_net; /* the net channel belongs to */
177 struct list_head clist; /* link in list of channels per unit */
178 rwlock_t upl; /* protects `ppp' */
179 #ifdef CONFIG_PPP_MULTILINK
180 u8 avail; /* flag used in multilink stuff */
181 u8 had_frag; /* >= 1 fragments have been sent */
182 u32 lastseq; /* MP: last sequence # received */
183 int speed; /* speed of the corresponding ppp channel*/
184 #endif /* CONFIG_PPP_MULTILINK */
185 };
186
187 /*
188 * SMP locking issues:
189 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
190 * list and the ppp.n_channels field, you need to take both locks
191 * before you modify them.
192 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
193 * channel.downl.
194 */
195
196 static DEFINE_MUTEX(ppp_mutex);
197 static atomic_t ppp_unit_count = ATOMIC_INIT(0);
198 static atomic_t channel_count = ATOMIC_INIT(0);
199
200 /* per-net private data for this module */
201 static int ppp_net_id __read_mostly;
202 struct ppp_net {
203 /* units to ppp mapping */
204 struct idr units_idr;
205
206 /*
207 * all_ppp_mutex protects the units_idr mapping.
208 * It also ensures that finding a ppp unit in the units_idr
209 * map and updating its file.refcnt field is atomic.
210 */
211 struct mutex all_ppp_mutex;
212
213 /* channels */
214 struct list_head all_channels;
215 struct list_head new_channels;
216 int last_channel_index;
217
218 /*
219 * all_channels_lock protects all_channels and
220 * last_channel_index, and the atomicity of find
221 * a channel and updating its file.refcnt field.
222 */
223 spinlock_t all_channels_lock;
224 };
225
226 /* Get the PPP protocol number from a skb */
227 #define PPP_PROTO(skb) get_unaligned_be16((skb)->data)
228
229 /* We limit the length of ppp->file.rq to this (arbitrary) value */
230 #define PPP_MAX_RQLEN 32
231
232 /*
233 * Maximum number of multilink fragments queued up.
234 * This has to be large enough to cope with the maximum latency of
235 * the slowest channel relative to the others. Strictly it should
236 * depend on the number of channels and their characteristics.
237 */
238 #define PPP_MP_MAX_QLEN 128
239
240 /* Multilink header bits. */
241 #define B 0x80 /* this fragment begins a packet */
242 #define E 0x40 /* this fragment ends a packet */
243
244 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */
245 #define seq_before(a, b) ((s32)((a) - (b)) < 0)
246 #define seq_after(a, b) ((s32)((a) - (b)) > 0)
247
248 /* Prototypes. */
249 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
250 struct file *file, unsigned int cmd, unsigned long arg);
251 static void ppp_xmit_process(struct ppp *ppp);
252 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
253 static void ppp_push(struct ppp *ppp);
254 static void ppp_channel_push(struct channel *pch);
255 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
256 struct channel *pch);
257 static void ppp_receive_error(struct ppp *ppp);
258 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
259 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
260 struct sk_buff *skb);
261 #ifdef CONFIG_PPP_MULTILINK
262 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
263 struct channel *pch);
264 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
265 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
266 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
267 #endif /* CONFIG_PPP_MULTILINK */
268 static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
269 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
270 static void ppp_ccp_closed(struct ppp *ppp);
271 static struct compressor *find_compressor(int type);
272 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
273 static struct ppp *ppp_create_interface(struct net *net, int unit, int *retp);
274 static void init_ppp_file(struct ppp_file *pf, int kind);
275 static void ppp_shutdown_interface(struct ppp *ppp);
276 static void ppp_destroy_interface(struct ppp *ppp);
277 static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit);
278 static struct channel *ppp_find_channel(struct ppp_net *pn, int unit);
279 static int ppp_connect_channel(struct channel *pch, int unit);
280 static int ppp_disconnect_channel(struct channel *pch);
281 static void ppp_destroy_channel(struct channel *pch);
282 static int unit_get(struct idr *p, void *ptr);
283 static int unit_set(struct idr *p, void *ptr, int n);
284 static void unit_put(struct idr *p, int n);
285 static void *unit_find(struct idr *p, int n);
286
287 static struct class *ppp_class;
288
289 /* per net-namespace data */
290 static inline struct ppp_net *ppp_pernet(struct net *net)
291 {
292 BUG_ON(!net);
293
294 return net_generic(net, ppp_net_id);
295 }
296
297 /* Translates a PPP protocol number to a NP index (NP == network protocol) */
298 static inline int proto_to_npindex(int proto)
299 {
300 switch (proto) {
301 case PPP_IP:
302 return NP_IP;
303 case PPP_IPV6:
304 return NP_IPV6;
305 case PPP_IPX:
306 return NP_IPX;
307 case PPP_AT:
308 return NP_AT;
309 case PPP_MPLS_UC:
310 return NP_MPLS_UC;
311 case PPP_MPLS_MC:
312 return NP_MPLS_MC;
313 }
314 return -EINVAL;
315 }
316
317 /* Translates an NP index into a PPP protocol number */
318 static const int npindex_to_proto[NUM_NP] = {
319 PPP_IP,
320 PPP_IPV6,
321 PPP_IPX,
322 PPP_AT,
323 PPP_MPLS_UC,
324 PPP_MPLS_MC,
325 };
326
327 /* Translates an ethertype into an NP index */
328 static inline int ethertype_to_npindex(int ethertype)
329 {
330 switch (ethertype) {
331 case ETH_P_IP:
332 return NP_IP;
333 case ETH_P_IPV6:
334 return NP_IPV6;
335 case ETH_P_IPX:
336 return NP_IPX;
337 case ETH_P_PPPTALK:
338 case ETH_P_ATALK:
339 return NP_AT;
340 case ETH_P_MPLS_UC:
341 return NP_MPLS_UC;
342 case ETH_P_MPLS_MC:
343 return NP_MPLS_MC;
344 }
345 return -1;
346 }
347
348 /* Translates an NP index into an ethertype */
349 static const int npindex_to_ethertype[NUM_NP] = {
350 ETH_P_IP,
351 ETH_P_IPV6,
352 ETH_P_IPX,
353 ETH_P_PPPTALK,
354 ETH_P_MPLS_UC,
355 ETH_P_MPLS_MC,
356 };
357
358 /*
359 * Locking shorthand.
360 */
361 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
362 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
363 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
364 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
365 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
366 ppp_recv_lock(ppp); } while (0)
367 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
368 ppp_xmit_unlock(ppp); } while (0)
369
370 /*
371 * /dev/ppp device routines.
372 * The /dev/ppp device is used by pppd to control the ppp unit.
373 * It supports the read, write, ioctl and poll functions.
374 * Open instances of /dev/ppp can be in one of three states:
375 * unattached, attached to a ppp unit, or attached to a ppp channel.
376 */
377 static int ppp_open(struct inode *inode, struct file *file)
378 {
379 /*
380 * This could (should?) be enforced by the permissions on /dev/ppp.
381 */
382 if (!capable(CAP_NET_ADMIN))
383 return -EPERM;
384 return 0;
385 }
386
387 static int ppp_release(struct inode *unused, struct file *file)
388 {
389 struct ppp_file *pf = file->private_data;
390 struct ppp *ppp;
391
392 if (pf) {
393 file->private_data = NULL;
394 if (pf->kind == INTERFACE) {
395 ppp = PF_TO_PPP(pf);
396 if (file == ppp->owner)
397 ppp_shutdown_interface(ppp);
398 }
399 if (atomic_dec_and_test(&pf->refcnt)) {
400 switch (pf->kind) {
401 case INTERFACE:
402 ppp_destroy_interface(PF_TO_PPP(pf));
403 break;
404 case CHANNEL:
405 ppp_destroy_channel(PF_TO_CHANNEL(pf));
406 break;
407 }
408 }
409 }
410 return 0;
411 }
412
413 static ssize_t ppp_read(struct file *file, char __user *buf,
414 size_t count, loff_t *ppos)
415 {
416 struct ppp_file *pf = file->private_data;
417 DECLARE_WAITQUEUE(wait, current);
418 ssize_t ret;
419 struct sk_buff *skb = NULL;
420 struct iovec iov;
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 if (skb_copy_datagram_iovec(skb, 0, &iov, skb->len))
467 goto outf;
468 ret = skb->len;
469
470 outf:
471 kfree_skb(skb);
472 out:
473 return ret;
474 }
475
476 static ssize_t ppp_write(struct file *file, const char __user *buf,
477 size_t count, loff_t *ppos)
478 {
479 struct ppp_file *pf = file->private_data;
480 struct sk_buff *skb;
481 ssize_t ret;
482
483 if (!pf)
484 return -ENXIO;
485 ret = -ENOMEM;
486 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
487 if (!skb)
488 goto out;
489 skb_reserve(skb, pf->hdrlen);
490 ret = -EFAULT;
491 if (copy_from_user(skb_put(skb, count), buf, count)) {
492 kfree_skb(skb);
493 goto out;
494 }
495
496 skb_queue_tail(&pf->xq, skb);
497
498 switch (pf->kind) {
499 case INTERFACE:
500 ppp_xmit_process(PF_TO_PPP(pf));
501 break;
502 case CHANNEL:
503 ppp_channel_push(PF_TO_CHANNEL(pf));
504 break;
505 }
506
507 ret = count;
508
509 out:
510 return ret;
511 }
512
513 /* No kernel lock - fine */
514 static unsigned int ppp_poll(struct file *file, poll_table *wait)
515 {
516 struct ppp_file *pf = file->private_data;
517 unsigned int mask;
518
519 if (!pf)
520 return 0;
521 poll_wait(file, &pf->rwait, wait);
522 mask = POLLOUT | POLLWRNORM;
523 if (skb_peek(&pf->rq))
524 mask |= POLLIN | POLLRDNORM;
525 if (pf->dead)
526 mask |= POLLHUP;
527 else if (pf->kind == INTERFACE) {
528 /* see comment in ppp_read */
529 struct ppp *ppp = PF_TO_PPP(pf);
530 if (ppp->n_channels == 0 &&
531 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
532 mask |= POLLIN | POLLRDNORM;
533 }
534
535 return mask;
536 }
537
538 #ifdef CONFIG_PPP_FILTER
539 static int get_filter(void __user *arg, struct sock_filter **p)
540 {
541 struct sock_fprog uprog;
542 struct sock_filter *code = NULL;
543 int len, err;
544
545 if (copy_from_user(&uprog, arg, sizeof(uprog)))
546 return -EFAULT;
547
548 if (!uprog.len) {
549 *p = NULL;
550 return 0;
551 }
552
553 len = uprog.len * sizeof(struct sock_filter);
554 code = memdup_user(uprog.filter, len);
555 if (IS_ERR(code))
556 return PTR_ERR(code);
557
558 err = sk_chk_filter(code, uprog.len);
559 if (err) {
560 kfree(code);
561 return err;
562 }
563
564 *p = code;
565 return uprog.len;
566 }
567 #endif /* CONFIG_PPP_FILTER */
568
569 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
570 {
571 struct ppp_file *pf = file->private_data;
572 struct ppp *ppp;
573 int err = -EFAULT, val, val2, i;
574 struct ppp_idle idle;
575 struct npioctl npi;
576 int unit, cflags;
577 struct slcompress *vj;
578 void __user *argp = (void __user *)arg;
579 int __user *p = argp;
580
581 if (!pf)
582 return ppp_unattached_ioctl(current->nsproxy->net_ns,
583 pf, file, cmd, arg);
584
585 if (cmd == PPPIOCDETACH) {
586 /*
587 * We have to be careful here... if the file descriptor
588 * has been dup'd, we could have another process in the
589 * middle of a poll using the same file *, so we had
590 * better not free the interface data structures -
591 * instead we fail the ioctl. Even in this case, we
592 * shut down the interface if we are the owner of it.
593 * Actually, we should get rid of PPPIOCDETACH, userland
594 * (i.e. pppd) could achieve the same effect by closing
595 * this fd and reopening /dev/ppp.
596 */
597 err = -EINVAL;
598 mutex_lock(&ppp_mutex);
599 if (pf->kind == INTERFACE) {
600 ppp = PF_TO_PPP(pf);
601 if (file == ppp->owner)
602 ppp_shutdown_interface(ppp);
603 }
604 if (atomic_long_read(&file->f_count) <= 2) {
605 ppp_release(NULL, file);
606 err = 0;
607 } else
608 pr_warn("PPPIOCDETACH file->f_count=%ld\n",
609 atomic_long_read(&file->f_count));
610 mutex_unlock(&ppp_mutex);
611 return err;
612 }
613
614 if (pf->kind == CHANNEL) {
615 struct channel *pch;
616 struct ppp_channel *chan;
617
618 mutex_lock(&ppp_mutex);
619 pch = PF_TO_CHANNEL(pf);
620
621 switch (cmd) {
622 case PPPIOCCONNECT:
623 if (get_user(unit, p))
624 break;
625 err = ppp_connect_channel(pch, unit);
626 break;
627
628 case PPPIOCDISCONN:
629 err = ppp_disconnect_channel(pch);
630 break;
631
632 default:
633 down_read(&pch->chan_sem);
634 chan = pch->chan;
635 err = -ENOTTY;
636 if (chan && chan->ops->ioctl)
637 err = chan->ops->ioctl(chan, cmd, arg);
638 up_read(&pch->chan_sem);
639 }
640 mutex_unlock(&ppp_mutex);
641 return err;
642 }
643
644 if (pf->kind != INTERFACE) {
645 /* can't happen */
646 pr_err("PPP: not interface or channel??\n");
647 return -EINVAL;
648 }
649
650 mutex_lock(&ppp_mutex);
651 ppp = PF_TO_PPP(pf);
652 switch (cmd) {
653 case PPPIOCSMRU:
654 if (get_user(val, p))
655 break;
656 ppp->mru = val;
657 err = 0;
658 break;
659
660 case PPPIOCSFLAGS:
661 if (get_user(val, p))
662 break;
663 ppp_lock(ppp);
664 cflags = ppp->flags & ~val;
665 ppp->flags = val & SC_FLAG_BITS;
666 ppp_unlock(ppp);
667 if (cflags & SC_CCP_OPEN)
668 ppp_ccp_closed(ppp);
669 err = 0;
670 break;
671
672 case PPPIOCGFLAGS:
673 val = ppp->flags | ppp->xstate | ppp->rstate;
674 if (put_user(val, p))
675 break;
676 err = 0;
677 break;
678
679 case PPPIOCSCOMPRESS:
680 err = ppp_set_compress(ppp, arg);
681 break;
682
683 case PPPIOCGUNIT:
684 if (put_user(ppp->file.index, p))
685 break;
686 err = 0;
687 break;
688
689 case PPPIOCSDEBUG:
690 if (get_user(val, p))
691 break;
692 ppp->debug = val;
693 err = 0;
694 break;
695
696 case PPPIOCGDEBUG:
697 if (put_user(ppp->debug, p))
698 break;
699 err = 0;
700 break;
701
702 case PPPIOCGIDLE:
703 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
704 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
705 if (copy_to_user(argp, &idle, sizeof(idle)))
706 break;
707 err = 0;
708 break;
709
710 case PPPIOCSMAXCID:
711 if (get_user(val, p))
712 break;
713 val2 = 15;
714 if ((val >> 16) != 0) {
715 val2 = val >> 16;
716 val &= 0xffff;
717 }
718 vj = slhc_init(val2+1, val+1);
719 if (!vj) {
720 netdev_err(ppp->dev,
721 "PPP: no memory (VJ compressor)\n");
722 err = -ENOMEM;
723 break;
724 }
725 ppp_lock(ppp);
726 if (ppp->vj)
727 slhc_free(ppp->vj);
728 ppp->vj = vj;
729 ppp_unlock(ppp);
730 err = 0;
731 break;
732
733 case PPPIOCGNPMODE:
734 case PPPIOCSNPMODE:
735 if (copy_from_user(&npi, argp, sizeof(npi)))
736 break;
737 err = proto_to_npindex(npi.protocol);
738 if (err < 0)
739 break;
740 i = err;
741 if (cmd == PPPIOCGNPMODE) {
742 err = -EFAULT;
743 npi.mode = ppp->npmode[i];
744 if (copy_to_user(argp, &npi, sizeof(npi)))
745 break;
746 } else {
747 ppp->npmode[i] = npi.mode;
748 /* we may be able to transmit more packets now (??) */
749 netif_wake_queue(ppp->dev);
750 }
751 err = 0;
752 break;
753
754 #ifdef CONFIG_PPP_FILTER
755 case PPPIOCSPASS:
756 {
757 struct sock_filter *code;
758 err = get_filter(argp, &code);
759 if (err >= 0) {
760 ppp_lock(ppp);
761 kfree(ppp->pass_filter);
762 ppp->pass_filter = code;
763 ppp->pass_len = err;
764 ppp_unlock(ppp);
765 err = 0;
766 }
767 break;
768 }
769 case PPPIOCSACTIVE:
770 {
771 struct sock_filter *code;
772 err = get_filter(argp, &code);
773 if (err >= 0) {
774 ppp_lock(ppp);
775 kfree(ppp->active_filter);
776 ppp->active_filter = code;
777 ppp->active_len = err;
778 ppp_unlock(ppp);
779 err = 0;
780 }
781 break;
782 }
783 #endif /* CONFIG_PPP_FILTER */
784
785 #ifdef CONFIG_PPP_MULTILINK
786 case PPPIOCSMRRU:
787 if (get_user(val, p))
788 break;
789 ppp_recv_lock(ppp);
790 ppp->mrru = val;
791 ppp_recv_unlock(ppp);
792 err = 0;
793 break;
794 #endif /* CONFIG_PPP_MULTILINK */
795
796 default:
797 err = -ENOTTY;
798 }
799 mutex_unlock(&ppp_mutex);
800 return err;
801 }
802
803 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
804 struct file *file, unsigned int cmd, unsigned long arg)
805 {
806 int unit, err = -EFAULT;
807 struct ppp *ppp;
808 struct channel *chan;
809 struct ppp_net *pn;
810 int __user *p = (int __user *)arg;
811
812 mutex_lock(&ppp_mutex);
813 switch (cmd) {
814 case PPPIOCNEWUNIT:
815 /* Create a new ppp unit */
816 if (get_user(unit, p))
817 break;
818 ppp = ppp_create_interface(net, unit, &err);
819 if (!ppp)
820 break;
821 file->private_data = &ppp->file;
822 ppp->owner = file;
823 err = -EFAULT;
824 if (put_user(ppp->file.index, p))
825 break;
826 err = 0;
827 break;
828
829 case PPPIOCATTACH:
830 /* Attach to an existing ppp unit */
831 if (get_user(unit, p))
832 break;
833 err = -ENXIO;
834 pn = ppp_pernet(net);
835 mutex_lock(&pn->all_ppp_mutex);
836 ppp = ppp_find_unit(pn, unit);
837 if (ppp) {
838 atomic_inc(&ppp->file.refcnt);
839 file->private_data = &ppp->file;
840 err = 0;
841 }
842 mutex_unlock(&pn->all_ppp_mutex);
843 break;
844
845 case PPPIOCATTCHAN:
846 if (get_user(unit, p))
847 break;
848 err = -ENXIO;
849 pn = ppp_pernet(net);
850 spin_lock_bh(&pn->all_channels_lock);
851 chan = ppp_find_channel(pn, unit);
852 if (chan) {
853 atomic_inc(&chan->file.refcnt);
854 file->private_data = &chan->file;
855 err = 0;
856 }
857 spin_unlock_bh(&pn->all_channels_lock);
858 break;
859
860 default:
861 err = -ENOTTY;
862 }
863 mutex_unlock(&ppp_mutex);
864 return err;
865 }
866
867 static const struct file_operations ppp_device_fops = {
868 .owner = THIS_MODULE,
869 .read = ppp_read,
870 .write = ppp_write,
871 .poll = ppp_poll,
872 .unlocked_ioctl = ppp_ioctl,
873 .open = ppp_open,
874 .release = ppp_release,
875 .llseek = noop_llseek,
876 };
877
878 static __net_init int ppp_init_net(struct net *net)
879 {
880 struct ppp_net *pn = net_generic(net, ppp_net_id);
881
882 idr_init(&pn->units_idr);
883 mutex_init(&pn->all_ppp_mutex);
884
885 INIT_LIST_HEAD(&pn->all_channels);
886 INIT_LIST_HEAD(&pn->new_channels);
887
888 spin_lock_init(&pn->all_channels_lock);
889
890 return 0;
891 }
892
893 static __net_exit void ppp_exit_net(struct net *net)
894 {
895 struct ppp_net *pn = net_generic(net, ppp_net_id);
896
897 idr_destroy(&pn->units_idr);
898 }
899
900 static struct pernet_operations ppp_net_ops = {
901 .init = ppp_init_net,
902 .exit = ppp_exit_net,
903 .id = &ppp_net_id,
904 .size = sizeof(struct ppp_net),
905 };
906
907 #define PPP_MAJOR 108
908
909 /* Called at boot time if ppp is compiled into the kernel,
910 or at module load time (from init_module) if compiled as a module. */
911 static int __init ppp_init(void)
912 {
913 int err;
914
915 pr_info("PPP generic driver version " PPP_VERSION "\n");
916
917 err = register_pernet_device(&ppp_net_ops);
918 if (err) {
919 pr_err("failed to register PPP pernet device (%d)\n", err);
920 goto out;
921 }
922
923 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
924 if (err) {
925 pr_err("failed to register PPP device (%d)\n", err);
926 goto out_net;
927 }
928
929 ppp_class = class_create(THIS_MODULE, "ppp");
930 if (IS_ERR(ppp_class)) {
931 err = PTR_ERR(ppp_class);
932 goto out_chrdev;
933 }
934
935 /* not a big deal if we fail here :-) */
936 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
937
938 return 0;
939
940 out_chrdev:
941 unregister_chrdev(PPP_MAJOR, "ppp");
942 out_net:
943 unregister_pernet_device(&ppp_net_ops);
944 out:
945 return err;
946 }
947
948 /*
949 * Network interface unit routines.
950 */
951 static netdev_tx_t
952 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
953 {
954 struct ppp *ppp = netdev_priv(dev);
955 int npi, proto;
956 unsigned char *pp;
957
958 npi = ethertype_to_npindex(ntohs(skb->protocol));
959 if (npi < 0)
960 goto outf;
961
962 /* Drop, accept or reject the packet */
963 switch (ppp->npmode[npi]) {
964 case NPMODE_PASS:
965 break;
966 case NPMODE_QUEUE:
967 /* it would be nice to have a way to tell the network
968 system to queue this one up for later. */
969 goto outf;
970 case NPMODE_DROP:
971 case NPMODE_ERROR:
972 goto outf;
973 }
974
975 /* Put the 2-byte PPP protocol number on the front,
976 making sure there is room for the address and control fields. */
977 if (skb_cow_head(skb, PPP_HDRLEN))
978 goto outf;
979
980 pp = skb_push(skb, 2);
981 proto = npindex_to_proto[npi];
982 put_unaligned_be16(proto, pp);
983
984 skb_queue_tail(&ppp->file.xq, skb);
985 ppp_xmit_process(ppp);
986 return NETDEV_TX_OK;
987
988 outf:
989 kfree_skb(skb);
990 ++dev->stats.tx_dropped;
991 return NETDEV_TX_OK;
992 }
993
994 static int
995 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
996 {
997 struct ppp *ppp = netdev_priv(dev);
998 int err = -EFAULT;
999 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
1000 struct ppp_stats stats;
1001 struct ppp_comp_stats cstats;
1002 char *vers;
1003
1004 switch (cmd) {
1005 case SIOCGPPPSTATS:
1006 ppp_get_stats(ppp, &stats);
1007 if (copy_to_user(addr, &stats, sizeof(stats)))
1008 break;
1009 err = 0;
1010 break;
1011
1012 case SIOCGPPPCSTATS:
1013 memset(&cstats, 0, sizeof(cstats));
1014 if (ppp->xc_state)
1015 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
1016 if (ppp->rc_state)
1017 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
1018 if (copy_to_user(addr, &cstats, sizeof(cstats)))
1019 break;
1020 err = 0;
1021 break;
1022
1023 case SIOCGPPPVER:
1024 vers = PPP_VERSION;
1025 if (copy_to_user(addr, vers, strlen(vers) + 1))
1026 break;
1027 err = 0;
1028 break;
1029
1030 default:
1031 err = -EINVAL;
1032 }
1033
1034 return err;
1035 }
1036
1037 static struct rtnl_link_stats64*
1038 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64)
1039 {
1040 struct ppp *ppp = netdev_priv(dev);
1041
1042 ppp_recv_lock(ppp);
1043 stats64->rx_packets = ppp->stats64.rx_packets;
1044 stats64->rx_bytes = ppp->stats64.rx_bytes;
1045 ppp_recv_unlock(ppp);
1046
1047 ppp_xmit_lock(ppp);
1048 stats64->tx_packets = ppp->stats64.tx_packets;
1049 stats64->tx_bytes = ppp->stats64.tx_bytes;
1050 ppp_xmit_unlock(ppp);
1051
1052 stats64->rx_errors = dev->stats.rx_errors;
1053 stats64->tx_errors = dev->stats.tx_errors;
1054 stats64->rx_dropped = dev->stats.rx_dropped;
1055 stats64->tx_dropped = dev->stats.tx_dropped;
1056 stats64->rx_length_errors = dev->stats.rx_length_errors;
1057
1058 return stats64;
1059 }
1060
1061 static struct lock_class_key ppp_tx_busylock;
1062 static int ppp_dev_init(struct net_device *dev)
1063 {
1064 dev->qdisc_tx_busylock = &ppp_tx_busylock;
1065 return 0;
1066 }
1067
1068 static const struct net_device_ops ppp_netdev_ops = {
1069 .ndo_init = ppp_dev_init,
1070 .ndo_start_xmit = ppp_start_xmit,
1071 .ndo_do_ioctl = ppp_net_ioctl,
1072 .ndo_get_stats64 = ppp_get_stats64,
1073 };
1074
1075 static void ppp_setup(struct net_device *dev)
1076 {
1077 dev->netdev_ops = &ppp_netdev_ops;
1078 dev->hard_header_len = PPP_HDRLEN;
1079 dev->mtu = PPP_MRU;
1080 dev->addr_len = 0;
1081 dev->tx_queue_len = 3;
1082 dev->type = ARPHRD_PPP;
1083 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1084 dev->features |= NETIF_F_NETNS_LOCAL;
1085 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1086 }
1087
1088 /*
1089 * Transmit-side routines.
1090 */
1091
1092 /*
1093 * Called to do any work queued up on the transmit side
1094 * that can now be done.
1095 */
1096 static void
1097 ppp_xmit_process(struct ppp *ppp)
1098 {
1099 struct sk_buff *skb;
1100
1101 ppp_xmit_lock(ppp);
1102 if (!ppp->closing) {
1103 ppp_push(ppp);
1104 while (!ppp->xmit_pending &&
1105 (skb = skb_dequeue(&ppp->file.xq)))
1106 ppp_send_frame(ppp, skb);
1107 /* If there's no work left to do, tell the core net
1108 code that we can accept some more. */
1109 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1110 netif_wake_queue(ppp->dev);
1111 else
1112 netif_stop_queue(ppp->dev);
1113 }
1114 ppp_xmit_unlock(ppp);
1115 }
1116
1117 static inline struct sk_buff *
1118 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1119 {
1120 struct sk_buff *new_skb;
1121 int len;
1122 int new_skb_size = ppp->dev->mtu +
1123 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1124 int compressor_skb_size = ppp->dev->mtu +
1125 ppp->xcomp->comp_extra + PPP_HDRLEN;
1126 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1127 if (!new_skb) {
1128 if (net_ratelimit())
1129 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n");
1130 return NULL;
1131 }
1132 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1133 skb_reserve(new_skb,
1134 ppp->dev->hard_header_len - PPP_HDRLEN);
1135
1136 /* compressor still expects A/C bytes in hdr */
1137 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1138 new_skb->data, skb->len + 2,
1139 compressor_skb_size);
1140 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1141 consume_skb(skb);
1142 skb = new_skb;
1143 skb_put(skb, len);
1144 skb_pull(skb, 2); /* pull off A/C bytes */
1145 } else if (len == 0) {
1146 /* didn't compress, or CCP not up yet */
1147 consume_skb(new_skb);
1148 new_skb = skb;
1149 } else {
1150 /*
1151 * (len < 0)
1152 * MPPE requires that we do not send unencrypted
1153 * frames. The compressor will return -1 if we
1154 * should drop the frame. We cannot simply test
1155 * the compress_proto because MPPE and MPPC share
1156 * the same number.
1157 */
1158 if (net_ratelimit())
1159 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n");
1160 kfree_skb(skb);
1161 consume_skb(new_skb);
1162 new_skb = NULL;
1163 }
1164 return new_skb;
1165 }
1166
1167 /*
1168 * Compress and send a frame.
1169 * The caller should have locked the xmit path,
1170 * and xmit_pending should be 0.
1171 */
1172 static void
1173 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1174 {
1175 int proto = PPP_PROTO(skb);
1176 struct sk_buff *new_skb;
1177 int len;
1178 unsigned char *cp;
1179
1180 if (proto < 0x8000) {
1181 #ifdef CONFIG_PPP_FILTER
1182 /* check if we should pass this packet */
1183 /* the filter instructions are constructed assuming
1184 a four-byte PPP header on each packet */
1185 *skb_push(skb, 2) = 1;
1186 if (ppp->pass_filter &&
1187 sk_run_filter(skb, ppp->pass_filter) == 0) {
1188 if (ppp->debug & 1)
1189 netdev_printk(KERN_DEBUG, ppp->dev,
1190 "PPP: outbound frame "
1191 "not passed\n");
1192 kfree_skb(skb);
1193 return;
1194 }
1195 /* if this packet passes the active filter, record the time */
1196 if (!(ppp->active_filter &&
1197 sk_run_filter(skb, ppp->active_filter) == 0))
1198 ppp->last_xmit = jiffies;
1199 skb_pull(skb, 2);
1200 #else
1201 /* for data packets, record the time */
1202 ppp->last_xmit = jiffies;
1203 #endif /* CONFIG_PPP_FILTER */
1204 }
1205
1206 ++ppp->stats64.tx_packets;
1207 ppp->stats64.tx_bytes += skb->len - 2;
1208
1209 switch (proto) {
1210 case PPP_IP:
1211 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1212 break;
1213 /* try to do VJ TCP header compression */
1214 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1215 GFP_ATOMIC);
1216 if (!new_skb) {
1217 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n");
1218 goto drop;
1219 }
1220 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1221 cp = skb->data + 2;
1222 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1223 new_skb->data + 2, &cp,
1224 !(ppp->flags & SC_NO_TCP_CCID));
1225 if (cp == skb->data + 2) {
1226 /* didn't compress */
1227 consume_skb(new_skb);
1228 } else {
1229 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1230 proto = PPP_VJC_COMP;
1231 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1232 } else {
1233 proto = PPP_VJC_UNCOMP;
1234 cp[0] = skb->data[2];
1235 }
1236 consume_skb(skb);
1237 skb = new_skb;
1238 cp = skb_put(skb, len + 2);
1239 cp[0] = 0;
1240 cp[1] = proto;
1241 }
1242 break;
1243
1244 case PPP_CCP:
1245 /* peek at outbound CCP frames */
1246 ppp_ccp_peek(ppp, skb, 0);
1247 break;
1248 }
1249
1250 /* try to do packet compression */
1251 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state &&
1252 proto != PPP_LCP && proto != PPP_CCP) {
1253 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1254 if (net_ratelimit())
1255 netdev_err(ppp->dev,
1256 "ppp: compression required but "
1257 "down - pkt dropped.\n");
1258 goto drop;
1259 }
1260 skb = pad_compress_skb(ppp, skb);
1261 if (!skb)
1262 goto drop;
1263 }
1264
1265 /*
1266 * If we are waiting for traffic (demand dialling),
1267 * queue it up for pppd to receive.
1268 */
1269 if (ppp->flags & SC_LOOP_TRAFFIC) {
1270 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1271 goto drop;
1272 skb_queue_tail(&ppp->file.rq, skb);
1273 wake_up_interruptible(&ppp->file.rwait);
1274 return;
1275 }
1276
1277 ppp->xmit_pending = skb;
1278 ppp_push(ppp);
1279 return;
1280
1281 drop:
1282 kfree_skb(skb);
1283 ++ppp->dev->stats.tx_errors;
1284 }
1285
1286 /*
1287 * Try to send the frame in xmit_pending.
1288 * The caller should have the xmit path locked.
1289 */
1290 static void
1291 ppp_push(struct ppp *ppp)
1292 {
1293 struct list_head *list;
1294 struct channel *pch;
1295 struct sk_buff *skb = ppp->xmit_pending;
1296
1297 if (!skb)
1298 return;
1299
1300 list = &ppp->channels;
1301 if (list_empty(list)) {
1302 /* nowhere to send the packet, just drop it */
1303 ppp->xmit_pending = NULL;
1304 kfree_skb(skb);
1305 return;
1306 }
1307
1308 if ((ppp->flags & SC_MULTILINK) == 0) {
1309 /* not doing multilink: send it down the first channel */
1310 list = list->next;
1311 pch = list_entry(list, struct channel, clist);
1312
1313 spin_lock_bh(&pch->downl);
1314 if (pch->chan) {
1315 if (pch->chan->ops->start_xmit(pch->chan, skb))
1316 ppp->xmit_pending = NULL;
1317 } else {
1318 /* channel got unregistered */
1319 kfree_skb(skb);
1320 ppp->xmit_pending = NULL;
1321 }
1322 spin_unlock_bh(&pch->downl);
1323 return;
1324 }
1325
1326 #ifdef CONFIG_PPP_MULTILINK
1327 /* Multilink: fragment the packet over as many links
1328 as can take the packet at the moment. */
1329 if (!ppp_mp_explode(ppp, skb))
1330 return;
1331 #endif /* CONFIG_PPP_MULTILINK */
1332
1333 ppp->xmit_pending = NULL;
1334 kfree_skb(skb);
1335 }
1336
1337 #ifdef CONFIG_PPP_MULTILINK
1338 static bool mp_protocol_compress __read_mostly = true;
1339 module_param(mp_protocol_compress, bool, S_IRUGO | S_IWUSR);
1340 MODULE_PARM_DESC(mp_protocol_compress,
1341 "compress protocol id in multilink fragments");
1342
1343 /*
1344 * Divide a packet to be transmitted into fragments and
1345 * send them out the individual links.
1346 */
1347 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1348 {
1349 int len, totlen;
1350 int i, bits, hdrlen, mtu;
1351 int flen;
1352 int navail, nfree, nzero;
1353 int nbigger;
1354 int totspeed;
1355 int totfree;
1356 unsigned char *p, *q;
1357 struct list_head *list;
1358 struct channel *pch;
1359 struct sk_buff *frag;
1360 struct ppp_channel *chan;
1361
1362 totspeed = 0; /*total bitrate of the bundle*/
1363 nfree = 0; /* # channels which have no packet already queued */
1364 navail = 0; /* total # of usable channels (not deregistered) */
1365 nzero = 0; /* number of channels with zero speed associated*/
1366 totfree = 0; /*total # of channels available and
1367 *having no queued packets before
1368 *starting the fragmentation*/
1369
1370 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1371 i = 0;
1372 list_for_each_entry(pch, &ppp->channels, clist) {
1373 if (pch->chan) {
1374 pch->avail = 1;
1375 navail++;
1376 pch->speed = pch->chan->speed;
1377 } else {
1378 pch->avail = 0;
1379 }
1380 if (pch->avail) {
1381 if (skb_queue_empty(&pch->file.xq) ||
1382 !pch->had_frag) {
1383 if (pch->speed == 0)
1384 nzero++;
1385 else
1386 totspeed += pch->speed;
1387
1388 pch->avail = 2;
1389 ++nfree;
1390 ++totfree;
1391 }
1392 if (!pch->had_frag && i < ppp->nxchan)
1393 ppp->nxchan = i;
1394 }
1395 ++i;
1396 }
1397 /*
1398 * Don't start sending this packet unless at least half of
1399 * the channels are free. This gives much better TCP
1400 * performance if we have a lot of channels.
1401 */
1402 if (nfree == 0 || nfree < navail / 2)
1403 return 0; /* can't take now, leave it in xmit_pending */
1404
1405 /* Do protocol field compression */
1406 p = skb->data;
1407 len = skb->len;
1408 if (*p == 0 && mp_protocol_compress) {
1409 ++p;
1410 --len;
1411 }
1412
1413 totlen = len;
1414 nbigger = len % nfree;
1415
1416 /* skip to the channel after the one we last used
1417 and start at that one */
1418 list = &ppp->channels;
1419 for (i = 0; i < ppp->nxchan; ++i) {
1420 list = list->next;
1421 if (list == &ppp->channels) {
1422 i = 0;
1423 break;
1424 }
1425 }
1426
1427 /* create a fragment for each channel */
1428 bits = B;
1429 while (len > 0) {
1430 list = list->next;
1431 if (list == &ppp->channels) {
1432 i = 0;
1433 continue;
1434 }
1435 pch = list_entry(list, struct channel, clist);
1436 ++i;
1437 if (!pch->avail)
1438 continue;
1439
1440 /*
1441 * Skip this channel if it has a fragment pending already and
1442 * we haven't given a fragment to all of the free channels.
1443 */
1444 if (pch->avail == 1) {
1445 if (nfree > 0)
1446 continue;
1447 } else {
1448 pch->avail = 1;
1449 }
1450
1451 /* check the channel's mtu and whether it is still attached. */
1452 spin_lock_bh(&pch->downl);
1453 if (pch->chan == NULL) {
1454 /* can't use this channel, it's being deregistered */
1455 if (pch->speed == 0)
1456 nzero--;
1457 else
1458 totspeed -= pch->speed;
1459
1460 spin_unlock_bh(&pch->downl);
1461 pch->avail = 0;
1462 totlen = len;
1463 totfree--;
1464 nfree--;
1465 if (--navail == 0)
1466 break;
1467 continue;
1468 }
1469
1470 /*
1471 *if the channel speed is not set divide
1472 *the packet evenly among the free channels;
1473 *otherwise divide it according to the speed
1474 *of the channel we are going to transmit on
1475 */
1476 flen = len;
1477 if (nfree > 0) {
1478 if (pch->speed == 0) {
1479 flen = len/nfree;
1480 if (nbigger > 0) {
1481 flen++;
1482 nbigger--;
1483 }
1484 } else {
1485 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
1486 ((totspeed*totfree)/pch->speed)) - hdrlen;
1487 if (nbigger > 0) {
1488 flen += ((totfree - nzero)*pch->speed)/totspeed;
1489 nbigger -= ((totfree - nzero)*pch->speed)/
1490 totspeed;
1491 }
1492 }
1493 nfree--;
1494 }
1495
1496 /*
1497 *check if we are on the last channel or
1498 *we exceded the length of the data to
1499 *fragment
1500 */
1501 if ((nfree <= 0) || (flen > len))
1502 flen = len;
1503 /*
1504 *it is not worth to tx on slow channels:
1505 *in that case from the resulting flen according to the
1506 *above formula will be equal or less than zero.
1507 *Skip the channel in this case
1508 */
1509 if (flen <= 0) {
1510 pch->avail = 2;
1511 spin_unlock_bh(&pch->downl);
1512 continue;
1513 }
1514
1515 /*
1516 * hdrlen includes the 2-byte PPP protocol field, but the
1517 * MTU counts only the payload excluding the protocol field.
1518 * (RFC1661 Section 2)
1519 */
1520 mtu = pch->chan->mtu - (hdrlen - 2);
1521 if (mtu < 4)
1522 mtu = 4;
1523 if (flen > mtu)
1524 flen = mtu;
1525 if (flen == len)
1526 bits |= E;
1527 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1528 if (!frag)
1529 goto noskb;
1530 q = skb_put(frag, flen + hdrlen);
1531
1532 /* make the MP header */
1533 put_unaligned_be16(PPP_MP, q);
1534 if (ppp->flags & SC_MP_XSHORTSEQ) {
1535 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1536 q[3] = ppp->nxseq;
1537 } else {
1538 q[2] = bits;
1539 q[3] = ppp->nxseq >> 16;
1540 q[4] = ppp->nxseq >> 8;
1541 q[5] = ppp->nxseq;
1542 }
1543
1544 memcpy(q + hdrlen, p, flen);
1545
1546 /* try to send it down the channel */
1547 chan = pch->chan;
1548 if (!skb_queue_empty(&pch->file.xq) ||
1549 !chan->ops->start_xmit(chan, frag))
1550 skb_queue_tail(&pch->file.xq, frag);
1551 pch->had_frag = 1;
1552 p += flen;
1553 len -= flen;
1554 ++ppp->nxseq;
1555 bits = 0;
1556 spin_unlock_bh(&pch->downl);
1557 }
1558 ppp->nxchan = i;
1559
1560 return 1;
1561
1562 noskb:
1563 spin_unlock_bh(&pch->downl);
1564 if (ppp->debug & 1)
1565 netdev_err(ppp->dev, "PPP: no memory (fragment)\n");
1566 ++ppp->dev->stats.tx_errors;
1567 ++ppp->nxseq;
1568 return 1; /* abandon the frame */
1569 }
1570 #endif /* CONFIG_PPP_MULTILINK */
1571
1572 /*
1573 * Try to send data out on a channel.
1574 */
1575 static void
1576 ppp_channel_push(struct channel *pch)
1577 {
1578 struct sk_buff *skb;
1579 struct ppp *ppp;
1580
1581 spin_lock_bh(&pch->downl);
1582 if (pch->chan) {
1583 while (!skb_queue_empty(&pch->file.xq)) {
1584 skb = skb_dequeue(&pch->file.xq);
1585 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1586 /* put the packet back and try again later */
1587 skb_queue_head(&pch->file.xq, skb);
1588 break;
1589 }
1590 }
1591 } else {
1592 /* channel got deregistered */
1593 skb_queue_purge(&pch->file.xq);
1594 }
1595 spin_unlock_bh(&pch->downl);
1596 /* see if there is anything from the attached unit to be sent */
1597 if (skb_queue_empty(&pch->file.xq)) {
1598 read_lock_bh(&pch->upl);
1599 ppp = pch->ppp;
1600 if (ppp)
1601 ppp_xmit_process(ppp);
1602 read_unlock_bh(&pch->upl);
1603 }
1604 }
1605
1606 /*
1607 * Receive-side routines.
1608 */
1609
1610 struct ppp_mp_skb_parm {
1611 u32 sequence;
1612 u8 BEbits;
1613 };
1614 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb))
1615
1616 static inline void
1617 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1618 {
1619 ppp_recv_lock(ppp);
1620 if (!ppp->closing)
1621 ppp_receive_frame(ppp, skb, pch);
1622 else
1623 kfree_skb(skb);
1624 ppp_recv_unlock(ppp);
1625 }
1626
1627 void
1628 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1629 {
1630 struct channel *pch = chan->ppp;
1631 int proto;
1632
1633 if (!pch) {
1634 kfree_skb(skb);
1635 return;
1636 }
1637
1638 read_lock_bh(&pch->upl);
1639 if (!pskb_may_pull(skb, 2)) {
1640 kfree_skb(skb);
1641 if (pch->ppp) {
1642 ++pch->ppp->dev->stats.rx_length_errors;
1643 ppp_receive_error(pch->ppp);
1644 }
1645 goto done;
1646 }
1647
1648 proto = PPP_PROTO(skb);
1649 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1650 /* put it on the channel queue */
1651 skb_queue_tail(&pch->file.rq, skb);
1652 /* drop old frames if queue too long */
1653 while (pch->file.rq.qlen > PPP_MAX_RQLEN &&
1654 (skb = skb_dequeue(&pch->file.rq)))
1655 kfree_skb(skb);
1656 wake_up_interruptible(&pch->file.rwait);
1657 } else {
1658 ppp_do_recv(pch->ppp, skb, pch);
1659 }
1660
1661 done:
1662 read_unlock_bh(&pch->upl);
1663 }
1664
1665 /* Put a 0-length skb in the receive queue as an error indication */
1666 void
1667 ppp_input_error(struct ppp_channel *chan, int code)
1668 {
1669 struct channel *pch = chan->ppp;
1670 struct sk_buff *skb;
1671
1672 if (!pch)
1673 return;
1674
1675 read_lock_bh(&pch->upl);
1676 if (pch->ppp) {
1677 skb = alloc_skb(0, GFP_ATOMIC);
1678 if (skb) {
1679 skb->len = 0; /* probably unnecessary */
1680 skb->cb[0] = code;
1681 ppp_do_recv(pch->ppp, skb, pch);
1682 }
1683 }
1684 read_unlock_bh(&pch->upl);
1685 }
1686
1687 /*
1688 * We come in here to process a received frame.
1689 * The receive side of the ppp unit is locked.
1690 */
1691 static void
1692 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1693 {
1694 /* note: a 0-length skb is used as an error indication */
1695 if (skb->len > 0) {
1696 #ifdef CONFIG_PPP_MULTILINK
1697 /* XXX do channel-level decompression here */
1698 if (PPP_PROTO(skb) == PPP_MP)
1699 ppp_receive_mp_frame(ppp, skb, pch);
1700 else
1701 #endif /* CONFIG_PPP_MULTILINK */
1702 ppp_receive_nonmp_frame(ppp, skb);
1703 } else {
1704 kfree_skb(skb);
1705 ppp_receive_error(ppp);
1706 }
1707 }
1708
1709 static void
1710 ppp_receive_error(struct ppp *ppp)
1711 {
1712 ++ppp->dev->stats.rx_errors;
1713 if (ppp->vj)
1714 slhc_toss(ppp->vj);
1715 }
1716
1717 static void
1718 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1719 {
1720 struct sk_buff *ns;
1721 int proto, len, npi;
1722
1723 /*
1724 * Decompress the frame, if compressed.
1725 * Note that some decompressors need to see uncompressed frames
1726 * that come in as well as compressed frames.
1727 */
1728 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) &&
1729 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1730 skb = ppp_decompress_frame(ppp, skb);
1731
1732 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1733 goto err;
1734
1735 proto = PPP_PROTO(skb);
1736 switch (proto) {
1737 case PPP_VJC_COMP:
1738 /* decompress VJ compressed packets */
1739 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1740 goto err;
1741
1742 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1743 /* copy to a new sk_buff with more tailroom */
1744 ns = dev_alloc_skb(skb->len + 128);
1745 if (!ns) {
1746 netdev_err(ppp->dev, "PPP: no memory "
1747 "(VJ decomp)\n");
1748 goto err;
1749 }
1750 skb_reserve(ns, 2);
1751 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1752 consume_skb(skb);
1753 skb = ns;
1754 }
1755 else
1756 skb->ip_summed = CHECKSUM_NONE;
1757
1758 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1759 if (len <= 0) {
1760 netdev_printk(KERN_DEBUG, ppp->dev,
1761 "PPP: VJ decompression error\n");
1762 goto err;
1763 }
1764 len += 2;
1765 if (len > skb->len)
1766 skb_put(skb, len - skb->len);
1767 else if (len < skb->len)
1768 skb_trim(skb, len);
1769 proto = PPP_IP;
1770 break;
1771
1772 case PPP_VJC_UNCOMP:
1773 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1774 goto err;
1775
1776 /* Until we fix the decompressor need to make sure
1777 * data portion is linear.
1778 */
1779 if (!pskb_may_pull(skb, skb->len))
1780 goto err;
1781
1782 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1783 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n");
1784 goto err;
1785 }
1786 proto = PPP_IP;
1787 break;
1788
1789 case PPP_CCP:
1790 ppp_ccp_peek(ppp, skb, 1);
1791 break;
1792 }
1793
1794 ++ppp->stats64.rx_packets;
1795 ppp->stats64.rx_bytes += skb->len - 2;
1796
1797 npi = proto_to_npindex(proto);
1798 if (npi < 0) {
1799 /* control or unknown frame - pass it to pppd */
1800 skb_queue_tail(&ppp->file.rq, skb);
1801 /* limit queue length by dropping old frames */
1802 while (ppp->file.rq.qlen > PPP_MAX_RQLEN &&
1803 (skb = skb_dequeue(&ppp->file.rq)))
1804 kfree_skb(skb);
1805 /* wake up any process polling or blocking on read */
1806 wake_up_interruptible(&ppp->file.rwait);
1807
1808 } else {
1809 /* network protocol frame - give it to the kernel */
1810
1811 #ifdef CONFIG_PPP_FILTER
1812 /* check if the packet passes the pass and active filters */
1813 /* the filter instructions are constructed assuming
1814 a four-byte PPP header on each packet */
1815 if (ppp->pass_filter || ppp->active_filter) {
1816 if (skb_unclone(skb, GFP_ATOMIC))
1817 goto err;
1818
1819 *skb_push(skb, 2) = 0;
1820 if (ppp->pass_filter &&
1821 sk_run_filter(skb, ppp->pass_filter) == 0) {
1822 if (ppp->debug & 1)
1823 netdev_printk(KERN_DEBUG, ppp->dev,
1824 "PPP: inbound frame "
1825 "not passed\n");
1826 kfree_skb(skb);
1827 return;
1828 }
1829 if (!(ppp->active_filter &&
1830 sk_run_filter(skb, ppp->active_filter) == 0))
1831 ppp->last_recv = jiffies;
1832 __skb_pull(skb, 2);
1833 } else
1834 #endif /* CONFIG_PPP_FILTER */
1835 ppp->last_recv = jiffies;
1836
1837 if ((ppp->dev->flags & IFF_UP) == 0 ||
1838 ppp->npmode[npi] != NPMODE_PASS) {
1839 kfree_skb(skb);
1840 } else {
1841 /* chop off protocol */
1842 skb_pull_rcsum(skb, 2);
1843 skb->dev = ppp->dev;
1844 skb->protocol = htons(npindex_to_ethertype[npi]);
1845 skb_reset_mac_header(skb);
1846 netif_rx(skb);
1847 }
1848 }
1849 return;
1850
1851 err:
1852 kfree_skb(skb);
1853 ppp_receive_error(ppp);
1854 }
1855
1856 static struct sk_buff *
1857 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1858 {
1859 int proto = PPP_PROTO(skb);
1860 struct sk_buff *ns;
1861 int len;
1862
1863 /* Until we fix all the decompressor's need to make sure
1864 * data portion is linear.
1865 */
1866 if (!pskb_may_pull(skb, skb->len))
1867 goto err;
1868
1869 if (proto == PPP_COMP) {
1870 int obuff_size;
1871
1872 switch(ppp->rcomp->compress_proto) {
1873 case CI_MPPE:
1874 obuff_size = ppp->mru + PPP_HDRLEN + 1;
1875 break;
1876 default:
1877 obuff_size = ppp->mru + PPP_HDRLEN;
1878 break;
1879 }
1880
1881 ns = dev_alloc_skb(obuff_size);
1882 if (!ns) {
1883 netdev_err(ppp->dev, "ppp_decompress_frame: "
1884 "no memory\n");
1885 goto err;
1886 }
1887 /* the decompressor still expects the A/C bytes in the hdr */
1888 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1889 skb->len + 2, ns->data, obuff_size);
1890 if (len < 0) {
1891 /* Pass the compressed frame to pppd as an
1892 error indication. */
1893 if (len == DECOMP_FATALERROR)
1894 ppp->rstate |= SC_DC_FERROR;
1895 kfree_skb(ns);
1896 goto err;
1897 }
1898
1899 consume_skb(skb);
1900 skb = ns;
1901 skb_put(skb, len);
1902 skb_pull(skb, 2); /* pull off the A/C bytes */
1903
1904 } else {
1905 /* Uncompressed frame - pass to decompressor so it
1906 can update its dictionary if necessary. */
1907 if (ppp->rcomp->incomp)
1908 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1909 skb->len + 2);
1910 }
1911
1912 return skb;
1913
1914 err:
1915 ppp->rstate |= SC_DC_ERROR;
1916 ppp_receive_error(ppp);
1917 return skb;
1918 }
1919
1920 #ifdef CONFIG_PPP_MULTILINK
1921 /*
1922 * Receive a multilink frame.
1923 * We put it on the reconstruction queue and then pull off
1924 * as many completed frames as we can.
1925 */
1926 static void
1927 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1928 {
1929 u32 mask, seq;
1930 struct channel *ch;
1931 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1932
1933 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
1934 goto err; /* no good, throw it away */
1935
1936 /* Decode sequence number and begin/end bits */
1937 if (ppp->flags & SC_MP_SHORTSEQ) {
1938 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1939 mask = 0xfff;
1940 } else {
1941 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1942 mask = 0xffffff;
1943 }
1944 PPP_MP_CB(skb)->BEbits = skb->data[2];
1945 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
1946
1947 /*
1948 * Do protocol ID decompression on the first fragment of each packet.
1949 */
1950 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1))
1951 *skb_push(skb, 1) = 0;
1952
1953 /*
1954 * Expand sequence number to 32 bits, making it as close
1955 * as possible to ppp->minseq.
1956 */
1957 seq |= ppp->minseq & ~mask;
1958 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
1959 seq += mask + 1;
1960 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
1961 seq -= mask + 1; /* should never happen */
1962 PPP_MP_CB(skb)->sequence = seq;
1963 pch->lastseq = seq;
1964
1965 /*
1966 * If this packet comes before the next one we were expecting,
1967 * drop it.
1968 */
1969 if (seq_before(seq, ppp->nextseq)) {
1970 kfree_skb(skb);
1971 ++ppp->dev->stats.rx_dropped;
1972 ppp_receive_error(ppp);
1973 return;
1974 }
1975
1976 /*
1977 * Reevaluate minseq, the minimum over all channels of the
1978 * last sequence number received on each channel. Because of
1979 * the increasing sequence number rule, we know that any fragment
1980 * before `minseq' which hasn't arrived is never going to arrive.
1981 * The list of channels can't change because we have the receive
1982 * side of the ppp unit locked.
1983 */
1984 list_for_each_entry(ch, &ppp->channels, clist) {
1985 if (seq_before(ch->lastseq, seq))
1986 seq = ch->lastseq;
1987 }
1988 if (seq_before(ppp->minseq, seq))
1989 ppp->minseq = seq;
1990
1991 /* Put the fragment on the reconstruction queue */
1992 ppp_mp_insert(ppp, skb);
1993
1994 /* If the queue is getting long, don't wait any longer for packets
1995 before the start of the queue. */
1996 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
1997 struct sk_buff *mskb = skb_peek(&ppp->mrq);
1998 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence))
1999 ppp->minseq = PPP_MP_CB(mskb)->sequence;
2000 }
2001
2002 /* Pull completed packets off the queue and receive them. */
2003 while ((skb = ppp_mp_reconstruct(ppp))) {
2004 if (pskb_may_pull(skb, 2))
2005 ppp_receive_nonmp_frame(ppp, skb);
2006 else {
2007 ++ppp->dev->stats.rx_length_errors;
2008 kfree_skb(skb);
2009 ppp_receive_error(ppp);
2010 }
2011 }
2012
2013 return;
2014
2015 err:
2016 kfree_skb(skb);
2017 ppp_receive_error(ppp);
2018 }
2019
2020 /*
2021 * Insert a fragment on the MP reconstruction queue.
2022 * The queue is ordered by increasing sequence number.
2023 */
2024 static void
2025 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
2026 {
2027 struct sk_buff *p;
2028 struct sk_buff_head *list = &ppp->mrq;
2029 u32 seq = PPP_MP_CB(skb)->sequence;
2030
2031 /* N.B. we don't need to lock the list lock because we have the
2032 ppp unit receive-side lock. */
2033 skb_queue_walk(list, p) {
2034 if (seq_before(seq, PPP_MP_CB(p)->sequence))
2035 break;
2036 }
2037 __skb_queue_before(list, p, skb);
2038 }
2039
2040 /*
2041 * Reconstruct a packet from the MP fragment queue.
2042 * We go through increasing sequence numbers until we find a
2043 * complete packet, or we get to the sequence number for a fragment
2044 * which hasn't arrived but might still do so.
2045 */
2046 static struct sk_buff *
2047 ppp_mp_reconstruct(struct ppp *ppp)
2048 {
2049 u32 seq = ppp->nextseq;
2050 u32 minseq = ppp->minseq;
2051 struct sk_buff_head *list = &ppp->mrq;
2052 struct sk_buff *p, *tmp;
2053 struct sk_buff *head, *tail;
2054 struct sk_buff *skb = NULL;
2055 int lost = 0, len = 0;
2056
2057 if (ppp->mrru == 0) /* do nothing until mrru is set */
2058 return NULL;
2059 head = list->next;
2060 tail = NULL;
2061 skb_queue_walk_safe(list, p, tmp) {
2062 again:
2063 if (seq_before(PPP_MP_CB(p)->sequence, seq)) {
2064 /* this can't happen, anyway ignore the skb */
2065 netdev_err(ppp->dev, "ppp_mp_reconstruct bad "
2066 "seq %u < %u\n",
2067 PPP_MP_CB(p)->sequence, seq);
2068 __skb_unlink(p, list);
2069 kfree_skb(p);
2070 continue;
2071 }
2072 if (PPP_MP_CB(p)->sequence != seq) {
2073 u32 oldseq;
2074 /* Fragment `seq' is missing. If it is after
2075 minseq, it might arrive later, so stop here. */
2076 if (seq_after(seq, minseq))
2077 break;
2078 /* Fragment `seq' is lost, keep going. */
2079 lost = 1;
2080 oldseq = seq;
2081 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)?
2082 minseq + 1: PPP_MP_CB(p)->sequence;
2083
2084 if (ppp->debug & 1)
2085 netdev_printk(KERN_DEBUG, ppp->dev,
2086 "lost frag %u..%u\n",
2087 oldseq, seq-1);
2088
2089 goto again;
2090 }
2091
2092 /*
2093 * At this point we know that all the fragments from
2094 * ppp->nextseq to seq are either present or lost.
2095 * Also, there are no complete packets in the queue
2096 * that have no missing fragments and end before this
2097 * fragment.
2098 */
2099
2100 /* B bit set indicates this fragment starts a packet */
2101 if (PPP_MP_CB(p)->BEbits & B) {
2102 head = p;
2103 lost = 0;
2104 len = 0;
2105 }
2106
2107 len += p->len;
2108
2109 /* Got a complete packet yet? */
2110 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) &&
2111 (PPP_MP_CB(head)->BEbits & B)) {
2112 if (len > ppp->mrru + 2) {
2113 ++ppp->dev->stats.rx_length_errors;
2114 netdev_printk(KERN_DEBUG, ppp->dev,
2115 "PPP: reconstructed packet"
2116 " is too long (%d)\n", len);
2117 } else {
2118 tail = p;
2119 break;
2120 }
2121 ppp->nextseq = seq + 1;
2122 }
2123
2124 /*
2125 * If this is the ending fragment of a packet,
2126 * and we haven't found a complete valid packet yet,
2127 * we can discard up to and including this fragment.
2128 */
2129 if (PPP_MP_CB(p)->BEbits & E) {
2130 struct sk_buff *tmp2;
2131
2132 skb_queue_reverse_walk_from_safe(list, p, tmp2) {
2133 if (ppp->debug & 1)
2134 netdev_printk(KERN_DEBUG, ppp->dev,
2135 "discarding frag %u\n",
2136 PPP_MP_CB(p)->sequence);
2137 __skb_unlink(p, list);
2138 kfree_skb(p);
2139 }
2140 head = skb_peek(list);
2141 if (!head)
2142 break;
2143 }
2144 ++seq;
2145 }
2146
2147 /* If we have a complete packet, copy it all into one skb. */
2148 if (tail != NULL) {
2149 /* If we have discarded any fragments,
2150 signal a receive error. */
2151 if (PPP_MP_CB(head)->sequence != ppp->nextseq) {
2152 skb_queue_walk_safe(list, p, tmp) {
2153 if (p == head)
2154 break;
2155 if (ppp->debug & 1)
2156 netdev_printk(KERN_DEBUG, ppp->dev,
2157 "discarding frag %u\n",
2158 PPP_MP_CB(p)->sequence);
2159 __skb_unlink(p, list);
2160 kfree_skb(p);
2161 }
2162
2163 if (ppp->debug & 1)
2164 netdev_printk(KERN_DEBUG, ppp->dev,
2165 " missed pkts %u..%u\n",
2166 ppp->nextseq,
2167 PPP_MP_CB(head)->sequence-1);
2168 ++ppp->dev->stats.rx_dropped;
2169 ppp_receive_error(ppp);
2170 }
2171
2172 skb = head;
2173 if (head != tail) {
2174 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list;
2175 p = skb_queue_next(list, head);
2176 __skb_unlink(skb, list);
2177 skb_queue_walk_from_safe(list, p, tmp) {
2178 __skb_unlink(p, list);
2179 *fragpp = p;
2180 p->next = NULL;
2181 fragpp = &p->next;
2182
2183 skb->len += p->len;
2184 skb->data_len += p->len;
2185 skb->truesize += p->truesize;
2186
2187 if (p == tail)
2188 break;
2189 }
2190 } else {
2191 __skb_unlink(skb, list);
2192 }
2193
2194 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1;
2195 }
2196
2197 return skb;
2198 }
2199 #endif /* CONFIG_PPP_MULTILINK */
2200
2201 /*
2202 * Channel interface.
2203 */
2204
2205 /* Create a new, unattached ppp channel. */
2206 int ppp_register_channel(struct ppp_channel *chan)
2207 {
2208 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2209 }
2210
2211 /* Create a new, unattached ppp channel for specified net. */
2212 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
2213 {
2214 struct channel *pch;
2215 struct ppp_net *pn;
2216
2217 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2218 if (!pch)
2219 return -ENOMEM;
2220
2221 pn = ppp_pernet(net);
2222
2223 pch->ppp = NULL;
2224 pch->chan = chan;
2225 pch->chan_net = net;
2226 chan->ppp = pch;
2227 init_ppp_file(&pch->file, CHANNEL);
2228 pch->file.hdrlen = chan->hdrlen;
2229 #ifdef CONFIG_PPP_MULTILINK
2230 pch->lastseq = -1;
2231 #endif /* CONFIG_PPP_MULTILINK */
2232 init_rwsem(&pch->chan_sem);
2233 spin_lock_init(&pch->downl);
2234 rwlock_init(&pch->upl);
2235
2236 spin_lock_bh(&pn->all_channels_lock);
2237 pch->file.index = ++pn->last_channel_index;
2238 list_add(&pch->list, &pn->new_channels);
2239 atomic_inc(&channel_count);
2240 spin_unlock_bh(&pn->all_channels_lock);
2241
2242 return 0;
2243 }
2244
2245 /*
2246 * Return the index of a channel.
2247 */
2248 int ppp_channel_index(struct ppp_channel *chan)
2249 {
2250 struct channel *pch = chan->ppp;
2251
2252 if (pch)
2253 return pch->file.index;
2254 return -1;
2255 }
2256
2257 /*
2258 * Return the PPP unit number to which a channel is connected.
2259 */
2260 int ppp_unit_number(struct ppp_channel *chan)
2261 {
2262 struct channel *pch = chan->ppp;
2263 int unit = -1;
2264
2265 if (pch) {
2266 read_lock_bh(&pch->upl);
2267 if (pch->ppp)
2268 unit = pch->ppp->file.index;
2269 read_unlock_bh(&pch->upl);
2270 }
2271 return unit;
2272 }
2273
2274 /*
2275 * Return the PPP device interface name of a channel.
2276 */
2277 char *ppp_dev_name(struct ppp_channel *chan)
2278 {
2279 struct channel *pch = chan->ppp;
2280 char *name = NULL;
2281
2282 if (pch) {
2283 read_lock_bh(&pch->upl);
2284 if (pch->ppp && pch->ppp->dev)
2285 name = pch->ppp->dev->name;
2286 read_unlock_bh(&pch->upl);
2287 }
2288 return name;
2289 }
2290
2291
2292 /*
2293 * Disconnect a channel from the generic layer.
2294 * This must be called in process context.
2295 */
2296 void
2297 ppp_unregister_channel(struct ppp_channel *chan)
2298 {
2299 struct channel *pch = chan->ppp;
2300 struct ppp_net *pn;
2301
2302 if (!pch)
2303 return; /* should never happen */
2304
2305 chan->ppp = NULL;
2306
2307 /*
2308 * This ensures that we have returned from any calls into the
2309 * the channel's start_xmit or ioctl routine before we proceed.
2310 */
2311 down_write(&pch->chan_sem);
2312 spin_lock_bh(&pch->downl);
2313 pch->chan = NULL;
2314 spin_unlock_bh(&pch->downl);
2315 up_write(&pch->chan_sem);
2316 ppp_disconnect_channel(pch);
2317
2318 pn = ppp_pernet(pch->chan_net);
2319 spin_lock_bh(&pn->all_channels_lock);
2320 list_del(&pch->list);
2321 spin_unlock_bh(&pn->all_channels_lock);
2322
2323 pch->file.dead = 1;
2324 wake_up_interruptible(&pch->file.rwait);
2325 if (atomic_dec_and_test(&pch->file.refcnt))
2326 ppp_destroy_channel(pch);
2327 }
2328
2329 /*
2330 * Callback from a channel when it can accept more to transmit.
2331 * This should be called at BH/softirq level, not interrupt level.
2332 */
2333 void
2334 ppp_output_wakeup(struct ppp_channel *chan)
2335 {
2336 struct channel *pch = chan->ppp;
2337
2338 if (!pch)
2339 return;
2340 ppp_channel_push(pch);
2341 }
2342
2343 /*
2344 * Compression control.
2345 */
2346
2347 /* Process the PPPIOCSCOMPRESS ioctl. */
2348 static int
2349 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2350 {
2351 int err;
2352 struct compressor *cp, *ocomp;
2353 struct ppp_option_data data;
2354 void *state, *ostate;
2355 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2356
2357 err = -EFAULT;
2358 if (copy_from_user(&data, (void __user *) arg, sizeof(data)) ||
2359 (data.length <= CCP_MAX_OPTION_LENGTH &&
2360 copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2361 goto out;
2362 err = -EINVAL;
2363 if (data.length > CCP_MAX_OPTION_LENGTH ||
2364 ccp_option[1] < 2 || ccp_option[1] > data.length)
2365 goto out;
2366
2367 cp = try_then_request_module(
2368 find_compressor(ccp_option[0]),
2369 "ppp-compress-%d", ccp_option[0]);
2370 if (!cp)
2371 goto out;
2372
2373 err = -ENOBUFS;
2374 if (data.transmit) {
2375 state = cp->comp_alloc(ccp_option, data.length);
2376 if (state) {
2377 ppp_xmit_lock(ppp);
2378 ppp->xstate &= ~SC_COMP_RUN;
2379 ocomp = ppp->xcomp;
2380 ostate = ppp->xc_state;
2381 ppp->xcomp = cp;
2382 ppp->xc_state = state;
2383 ppp_xmit_unlock(ppp);
2384 if (ostate) {
2385 ocomp->comp_free(ostate);
2386 module_put(ocomp->owner);
2387 }
2388 err = 0;
2389 } else
2390 module_put(cp->owner);
2391
2392 } else {
2393 state = cp->decomp_alloc(ccp_option, data.length);
2394 if (state) {
2395 ppp_recv_lock(ppp);
2396 ppp->rstate &= ~SC_DECOMP_RUN;
2397 ocomp = ppp->rcomp;
2398 ostate = ppp->rc_state;
2399 ppp->rcomp = cp;
2400 ppp->rc_state = state;
2401 ppp_recv_unlock(ppp);
2402 if (ostate) {
2403 ocomp->decomp_free(ostate);
2404 module_put(ocomp->owner);
2405 }
2406 err = 0;
2407 } else
2408 module_put(cp->owner);
2409 }
2410
2411 out:
2412 return err;
2413 }
2414
2415 /*
2416 * Look at a CCP packet and update our state accordingly.
2417 * We assume the caller has the xmit or recv path locked.
2418 */
2419 static void
2420 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2421 {
2422 unsigned char *dp;
2423 int len;
2424
2425 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2426 return; /* no header */
2427 dp = skb->data + 2;
2428
2429 switch (CCP_CODE(dp)) {
2430 case CCP_CONFREQ:
2431
2432 /* A ConfReq starts negotiation of compression
2433 * in one direction of transmission,
2434 * and hence brings it down...but which way?
2435 *
2436 * Remember:
2437 * A ConfReq indicates what the sender would like to receive
2438 */
2439 if(inbound)
2440 /* He is proposing what I should send */
2441 ppp->xstate &= ~SC_COMP_RUN;
2442 else
2443 /* I am proposing to what he should send */
2444 ppp->rstate &= ~SC_DECOMP_RUN;
2445
2446 break;
2447
2448 case CCP_TERMREQ:
2449 case CCP_TERMACK:
2450 /*
2451 * CCP is going down, both directions of transmission
2452 */
2453 ppp->rstate &= ~SC_DECOMP_RUN;
2454 ppp->xstate &= ~SC_COMP_RUN;
2455 break;
2456
2457 case CCP_CONFACK:
2458 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2459 break;
2460 len = CCP_LENGTH(dp);
2461 if (!pskb_may_pull(skb, len + 2))
2462 return; /* too short */
2463 dp += CCP_HDRLEN;
2464 len -= CCP_HDRLEN;
2465 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2466 break;
2467 if (inbound) {
2468 /* we will start receiving compressed packets */
2469 if (!ppp->rc_state)
2470 break;
2471 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2472 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2473 ppp->rstate |= SC_DECOMP_RUN;
2474 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2475 }
2476 } else {
2477 /* we will soon start sending compressed packets */
2478 if (!ppp->xc_state)
2479 break;
2480 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2481 ppp->file.index, 0, ppp->debug))
2482 ppp->xstate |= SC_COMP_RUN;
2483 }
2484 break;
2485
2486 case CCP_RESETACK:
2487 /* reset the [de]compressor */
2488 if ((ppp->flags & SC_CCP_UP) == 0)
2489 break;
2490 if (inbound) {
2491 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2492 ppp->rcomp->decomp_reset(ppp->rc_state);
2493 ppp->rstate &= ~SC_DC_ERROR;
2494 }
2495 } else {
2496 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2497 ppp->xcomp->comp_reset(ppp->xc_state);
2498 }
2499 break;
2500 }
2501 }
2502
2503 /* Free up compression resources. */
2504 static void
2505 ppp_ccp_closed(struct ppp *ppp)
2506 {
2507 void *xstate, *rstate;
2508 struct compressor *xcomp, *rcomp;
2509
2510 ppp_lock(ppp);
2511 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2512 ppp->xstate = 0;
2513 xcomp = ppp->xcomp;
2514 xstate = ppp->xc_state;
2515 ppp->xc_state = NULL;
2516 ppp->rstate = 0;
2517 rcomp = ppp->rcomp;
2518 rstate = ppp->rc_state;
2519 ppp->rc_state = NULL;
2520 ppp_unlock(ppp);
2521
2522 if (xstate) {
2523 xcomp->comp_free(xstate);
2524 module_put(xcomp->owner);
2525 }
2526 if (rstate) {
2527 rcomp->decomp_free(rstate);
2528 module_put(rcomp->owner);
2529 }
2530 }
2531
2532 /* List of compressors. */
2533 static LIST_HEAD(compressor_list);
2534 static DEFINE_SPINLOCK(compressor_list_lock);
2535
2536 struct compressor_entry {
2537 struct list_head list;
2538 struct compressor *comp;
2539 };
2540
2541 static struct compressor_entry *
2542 find_comp_entry(int proto)
2543 {
2544 struct compressor_entry *ce;
2545
2546 list_for_each_entry(ce, &compressor_list, list) {
2547 if (ce->comp->compress_proto == proto)
2548 return ce;
2549 }
2550 return NULL;
2551 }
2552
2553 /* Register a compressor */
2554 int
2555 ppp_register_compressor(struct compressor *cp)
2556 {
2557 struct compressor_entry *ce;
2558 int ret;
2559 spin_lock(&compressor_list_lock);
2560 ret = -EEXIST;
2561 if (find_comp_entry(cp->compress_proto))
2562 goto out;
2563 ret = -ENOMEM;
2564 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2565 if (!ce)
2566 goto out;
2567 ret = 0;
2568 ce->comp = cp;
2569 list_add(&ce->list, &compressor_list);
2570 out:
2571 spin_unlock(&compressor_list_lock);
2572 return ret;
2573 }
2574
2575 /* Unregister a compressor */
2576 void
2577 ppp_unregister_compressor(struct compressor *cp)
2578 {
2579 struct compressor_entry *ce;
2580
2581 spin_lock(&compressor_list_lock);
2582 ce = find_comp_entry(cp->compress_proto);
2583 if (ce && ce->comp == cp) {
2584 list_del(&ce->list);
2585 kfree(ce);
2586 }
2587 spin_unlock(&compressor_list_lock);
2588 }
2589
2590 /* Find a compressor. */
2591 static struct compressor *
2592 find_compressor(int type)
2593 {
2594 struct compressor_entry *ce;
2595 struct compressor *cp = NULL;
2596
2597 spin_lock(&compressor_list_lock);
2598 ce = find_comp_entry(type);
2599 if (ce) {
2600 cp = ce->comp;
2601 if (!try_module_get(cp->owner))
2602 cp = NULL;
2603 }
2604 spin_unlock(&compressor_list_lock);
2605 return cp;
2606 }
2607
2608 /*
2609 * Miscelleneous stuff.
2610 */
2611
2612 static void
2613 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2614 {
2615 struct slcompress *vj = ppp->vj;
2616
2617 memset(st, 0, sizeof(*st));
2618 st->p.ppp_ipackets = ppp->stats64.rx_packets;
2619 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2620 st->p.ppp_ibytes = ppp->stats64.rx_bytes;
2621 st->p.ppp_opackets = ppp->stats64.tx_packets;
2622 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2623 st->p.ppp_obytes = ppp->stats64.tx_bytes;
2624 if (!vj)
2625 return;
2626 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2627 st->vj.vjs_compressed = vj->sls_o_compressed;
2628 st->vj.vjs_searches = vj->sls_o_searches;
2629 st->vj.vjs_misses = vj->sls_o_misses;
2630 st->vj.vjs_errorin = vj->sls_i_error;
2631 st->vj.vjs_tossed = vj->sls_i_tossed;
2632 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2633 st->vj.vjs_compressedin = vj->sls_i_compressed;
2634 }
2635
2636 /*
2637 * Stuff for handling the lists of ppp units and channels
2638 * and for initialization.
2639 */
2640
2641 /*
2642 * Create a new ppp interface unit. Fails if it can't allocate memory
2643 * or if there is already a unit with the requested number.
2644 * unit == -1 means allocate a new number.
2645 */
2646 static struct ppp *
2647 ppp_create_interface(struct net *net, int unit, int *retp)
2648 {
2649 struct ppp *ppp;
2650 struct ppp_net *pn;
2651 struct net_device *dev = NULL;
2652 int ret = -ENOMEM;
2653 int i;
2654
2655 dev = alloc_netdev(sizeof(struct ppp), "", ppp_setup);
2656 if (!dev)
2657 goto out1;
2658
2659 pn = ppp_pernet(net);
2660
2661 ppp = netdev_priv(dev);
2662 ppp->dev = dev;
2663 ppp->mru = PPP_MRU;
2664 init_ppp_file(&ppp->file, INTERFACE);
2665 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2666 for (i = 0; i < NUM_NP; ++i)
2667 ppp->npmode[i] = NPMODE_PASS;
2668 INIT_LIST_HEAD(&ppp->channels);
2669 spin_lock_init(&ppp->rlock);
2670 spin_lock_init(&ppp->wlock);
2671 #ifdef CONFIG_PPP_MULTILINK
2672 ppp->minseq = -1;
2673 skb_queue_head_init(&ppp->mrq);
2674 #endif /* CONFIG_PPP_MULTILINK */
2675
2676 /*
2677 * drum roll: don't forget to set
2678 * the net device is belong to
2679 */
2680 dev_net_set(dev, net);
2681
2682 mutex_lock(&pn->all_ppp_mutex);
2683
2684 if (unit < 0) {
2685 unit = unit_get(&pn->units_idr, ppp);
2686 if (unit < 0) {
2687 ret = unit;
2688 goto out2;
2689 }
2690 } else {
2691 ret = -EEXIST;
2692 if (unit_find(&pn->units_idr, unit))
2693 goto out2; /* unit already exists */
2694 /*
2695 * if caller need a specified unit number
2696 * lets try to satisfy him, otherwise --
2697 * he should better ask us for new unit number
2698 *
2699 * NOTE: yes I know that returning EEXIST it's not
2700 * fair but at least pppd will ask us to allocate
2701 * new unit in this case so user is happy :)
2702 */
2703 unit = unit_set(&pn->units_idr, ppp, unit);
2704 if (unit < 0)
2705 goto out2;
2706 }
2707
2708 /* Initialize the new ppp unit */
2709 ppp->file.index = unit;
2710 sprintf(dev->name, "ppp%d", unit);
2711
2712 ret = register_netdev(dev);
2713 if (ret != 0) {
2714 unit_put(&pn->units_idr, unit);
2715 netdev_err(ppp->dev, "PPP: couldn't register device %s (%d)\n",
2716 dev->name, ret);
2717 goto out2;
2718 }
2719
2720 ppp->ppp_net = net;
2721
2722 atomic_inc(&ppp_unit_count);
2723 mutex_unlock(&pn->all_ppp_mutex);
2724
2725 *retp = 0;
2726 return ppp;
2727
2728 out2:
2729 mutex_unlock(&pn->all_ppp_mutex);
2730 free_netdev(dev);
2731 out1:
2732 *retp = ret;
2733 return NULL;
2734 }
2735
2736 /*
2737 * Initialize a ppp_file structure.
2738 */
2739 static void
2740 init_ppp_file(struct ppp_file *pf, int kind)
2741 {
2742 pf->kind = kind;
2743 skb_queue_head_init(&pf->xq);
2744 skb_queue_head_init(&pf->rq);
2745 atomic_set(&pf->refcnt, 1);
2746 init_waitqueue_head(&pf->rwait);
2747 }
2748
2749 /*
2750 * Take down a ppp interface unit - called when the owning file
2751 * (the one that created the unit) is closed or detached.
2752 */
2753 static void ppp_shutdown_interface(struct ppp *ppp)
2754 {
2755 struct ppp_net *pn;
2756
2757 pn = ppp_pernet(ppp->ppp_net);
2758 mutex_lock(&pn->all_ppp_mutex);
2759
2760 /* This will call dev_close() for us. */
2761 ppp_lock(ppp);
2762 if (!ppp->closing) {
2763 ppp->closing = 1;
2764 ppp_unlock(ppp);
2765 unregister_netdev(ppp->dev);
2766 unit_put(&pn->units_idr, ppp->file.index);
2767 } else
2768 ppp_unlock(ppp);
2769
2770 ppp->file.dead = 1;
2771 ppp->owner = NULL;
2772 wake_up_interruptible(&ppp->file.rwait);
2773
2774 mutex_unlock(&pn->all_ppp_mutex);
2775 }
2776
2777 /*
2778 * Free the memory used by a ppp unit. This is only called once
2779 * there are no channels connected to the unit and no file structs
2780 * that reference the unit.
2781 */
2782 static void ppp_destroy_interface(struct ppp *ppp)
2783 {
2784 atomic_dec(&ppp_unit_count);
2785
2786 if (!ppp->file.dead || ppp->n_channels) {
2787 /* "can't happen" */
2788 netdev_err(ppp->dev, "ppp: destroying ppp struct %p "
2789 "but dead=%d n_channels=%d !\n",
2790 ppp, ppp->file.dead, ppp->n_channels);
2791 return;
2792 }
2793
2794 ppp_ccp_closed(ppp);
2795 if (ppp->vj) {
2796 slhc_free(ppp->vj);
2797 ppp->vj = NULL;
2798 }
2799 skb_queue_purge(&ppp->file.xq);
2800 skb_queue_purge(&ppp->file.rq);
2801 #ifdef CONFIG_PPP_MULTILINK
2802 skb_queue_purge(&ppp->mrq);
2803 #endif /* CONFIG_PPP_MULTILINK */
2804 #ifdef CONFIG_PPP_FILTER
2805 kfree(ppp->pass_filter);
2806 ppp->pass_filter = NULL;
2807 kfree(ppp->active_filter);
2808 ppp->active_filter = NULL;
2809 #endif /* CONFIG_PPP_FILTER */
2810
2811 kfree_skb(ppp->xmit_pending);
2812
2813 free_netdev(ppp->dev);
2814 }
2815
2816 /*
2817 * Locate an existing ppp unit.
2818 * The caller should have locked the all_ppp_mutex.
2819 */
2820 static struct ppp *
2821 ppp_find_unit(struct ppp_net *pn, int unit)
2822 {
2823 return unit_find(&pn->units_idr, unit);
2824 }
2825
2826 /*
2827 * Locate an existing ppp channel.
2828 * The caller should have locked the all_channels_lock.
2829 * First we look in the new_channels list, then in the
2830 * all_channels list. If found in the new_channels list,
2831 * we move it to the all_channels list. This is for speed
2832 * when we have a lot of channels in use.
2833 */
2834 static struct channel *
2835 ppp_find_channel(struct ppp_net *pn, int unit)
2836 {
2837 struct channel *pch;
2838
2839 list_for_each_entry(pch, &pn->new_channels, list) {
2840 if (pch->file.index == unit) {
2841 list_move(&pch->list, &pn->all_channels);
2842 return pch;
2843 }
2844 }
2845
2846 list_for_each_entry(pch, &pn->all_channels, list) {
2847 if (pch->file.index == unit)
2848 return pch;
2849 }
2850
2851 return NULL;
2852 }
2853
2854 /*
2855 * Connect a PPP channel to a PPP interface unit.
2856 */
2857 static int
2858 ppp_connect_channel(struct channel *pch, int unit)
2859 {
2860 struct ppp *ppp;
2861 struct ppp_net *pn;
2862 int ret = -ENXIO;
2863 int hdrlen;
2864
2865 pn = ppp_pernet(pch->chan_net);
2866
2867 mutex_lock(&pn->all_ppp_mutex);
2868 ppp = ppp_find_unit(pn, unit);
2869 if (!ppp)
2870 goto out;
2871 write_lock_bh(&pch->upl);
2872 ret = -EINVAL;
2873 if (pch->ppp)
2874 goto outl;
2875
2876 ppp_lock(ppp);
2877 if (pch->file.hdrlen > ppp->file.hdrlen)
2878 ppp->file.hdrlen = pch->file.hdrlen;
2879 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2880 if (hdrlen > ppp->dev->hard_header_len)
2881 ppp->dev->hard_header_len = hdrlen;
2882 list_add_tail(&pch->clist, &ppp->channels);
2883 ++ppp->n_channels;
2884 pch->ppp = ppp;
2885 atomic_inc(&ppp->file.refcnt);
2886 ppp_unlock(ppp);
2887 ret = 0;
2888
2889 outl:
2890 write_unlock_bh(&pch->upl);
2891 out:
2892 mutex_unlock(&pn->all_ppp_mutex);
2893 return ret;
2894 }
2895
2896 /*
2897 * Disconnect a channel from its ppp unit.
2898 */
2899 static int
2900 ppp_disconnect_channel(struct channel *pch)
2901 {
2902 struct ppp *ppp;
2903 int err = -EINVAL;
2904
2905 write_lock_bh(&pch->upl);
2906 ppp = pch->ppp;
2907 pch->ppp = NULL;
2908 write_unlock_bh(&pch->upl);
2909 if (ppp) {
2910 /* remove it from the ppp unit's list */
2911 ppp_lock(ppp);
2912 list_del(&pch->clist);
2913 if (--ppp->n_channels == 0)
2914 wake_up_interruptible(&ppp->file.rwait);
2915 ppp_unlock(ppp);
2916 if (atomic_dec_and_test(&ppp->file.refcnt))
2917 ppp_destroy_interface(ppp);
2918 err = 0;
2919 }
2920 return err;
2921 }
2922
2923 /*
2924 * Free up the resources used by a ppp channel.
2925 */
2926 static void ppp_destroy_channel(struct channel *pch)
2927 {
2928 atomic_dec(&channel_count);
2929
2930 if (!pch->file.dead) {
2931 /* "can't happen" */
2932 pr_err("ppp: destroying undead channel %p !\n", pch);
2933 return;
2934 }
2935 skb_queue_purge(&pch->file.xq);
2936 skb_queue_purge(&pch->file.rq);
2937 kfree(pch);
2938 }
2939
2940 static void __exit ppp_cleanup(void)
2941 {
2942 /* should never happen */
2943 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2944 pr_err("PPP: removing module but units remain!\n");
2945 unregister_chrdev(PPP_MAJOR, "ppp");
2946 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
2947 class_destroy(ppp_class);
2948 unregister_pernet_device(&ppp_net_ops);
2949 }
2950
2951 /*
2952 * Units handling. Caller must protect concurrent access
2953 * by holding all_ppp_mutex
2954 */
2955
2956 /* associate pointer with specified number */
2957 static int unit_set(struct idr *p, void *ptr, int n)
2958 {
2959 int unit;
2960
2961 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL);
2962 if (unit == -ENOSPC)
2963 unit = -EINVAL;
2964 return unit;
2965 }
2966
2967 /* get new free unit number and associate pointer with it */
2968 static int unit_get(struct idr *p, void *ptr)
2969 {
2970 return idr_alloc(p, ptr, 0, 0, GFP_KERNEL);
2971 }
2972
2973 /* put unit number back to a pool */
2974 static void unit_put(struct idr *p, int n)
2975 {
2976 idr_remove(p, n);
2977 }
2978
2979 /* get pointer associated with the number */
2980 static void *unit_find(struct idr *p, int n)
2981 {
2982 return idr_find(p, n);
2983 }
2984
2985 /* Module/initialization stuff */
2986
2987 module_init(ppp_init);
2988 module_exit(ppp_cleanup);
2989
2990 EXPORT_SYMBOL(ppp_register_net_channel);
2991 EXPORT_SYMBOL(ppp_register_channel);
2992 EXPORT_SYMBOL(ppp_unregister_channel);
2993 EXPORT_SYMBOL(ppp_channel_index);
2994 EXPORT_SYMBOL(ppp_unit_number);
2995 EXPORT_SYMBOL(ppp_dev_name);
2996 EXPORT_SYMBOL(ppp_input);
2997 EXPORT_SYMBOL(ppp_input_error);
2998 EXPORT_SYMBOL(ppp_output_wakeup);
2999 EXPORT_SYMBOL(ppp_register_compressor);
3000 EXPORT_SYMBOL(ppp_unregister_compressor);
3001 MODULE_LICENSE("GPL");
3002 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
3003 MODULE_ALIAS("devname:ppp");
Linux with added FPC-III support