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