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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/sched/signal.h>
28#include <linux/kmod.h>
29#include <linux/init.h>
30#include <linux/list.h>
31#include <linux/idr.h>
32#include <linux/netdevice.h>
33#include <linux/poll.h>
34#include <linux/ppp_defs.h>
35#include <linux/filter.h>
36#include <linux/ppp-ioctl.h>
37#include <linux/ppp_channel.h>
38#include <linux/ppp-comp.h>
39#include <linux/skbuff.h>
40#include <linux/rtnetlink.h>
41#include <linux/if_arp.h>
42#include <linux/ip.h>
43#include <linux/tcp.h>
44#include <linux/spinlock.h>
45#include <linux/rwsem.h>
46#include <linux/stddef.h>
47#include <linux/device.h>
48#include <linux/mutex.h>
49#include <linux/slab.h>
50#include <linux/file.h>
51#include <asm/unaligned.h>
52#include <net/slhc_vj.h>
53#include <linux/atomic.h>
54#include <linux/refcount.h>
55
56#include <linux/nsproxy.h>
57#include <net/net_namespace.h>
58#include <net/netns/generic.h>
59
60#define PPP_VERSION "2.4.2"
61
62/*
63 * Network protocols we support.
64 */
65#define NP_IP 0 /* Internet Protocol V4 */
66#define NP_IPV6 1 /* Internet Protocol V6 */
67#define NP_IPX 2 /* IPX protocol */
68#define NP_AT 3 /* Appletalk protocol */
69#define NP_MPLS_UC 4 /* MPLS unicast */
70#define NP_MPLS_MC 5 /* MPLS multicast */
71#define NUM_NP 6 /* Number of NPs. */
72
73#define MPHDRLEN 6 /* multilink protocol header length */
74#define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */
75
76/*
77 * An instance of /dev/ppp can be associated with either a ppp
78 * interface unit or a ppp channel. In both cases, file->private_data
79 * points to one of these.
80 */
81struct ppp_file {
82 enum {
83 INTERFACE=1, CHANNEL
84 } kind;
85 struct sk_buff_head xq; /* pppd transmit queue */
86 struct sk_buff_head rq; /* receive queue for pppd */
87 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */
88 refcount_t refcnt; /* # refs (incl /dev/ppp attached) */
89 int hdrlen; /* space to leave for headers */
90 int index; /* interface unit / channel number */
91 int dead; /* unit/channel has been shut down */
92};
93
94#define PF_TO_X(pf, X) container_of(pf, X, file)
95
96#define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
97#define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
98
99/*
100 * Data structure to hold primary network stats for which
101 * we want to use 64 bit storage. Other network stats
102 * are stored in dev->stats of the ppp strucute.
103 */
104struct ppp_link_stats {
105 u64 rx_packets;
106 u64 tx_packets;
107 u64 rx_bytes;
108 u64 tx_bytes;
109};
110
111/*
112 * Data structure describing one ppp unit.
113 * A ppp unit corresponds to a ppp network interface device
114 * and represents a multilink bundle.
115 * It can have 0 or more ppp channels connected to it.
116 */
117struct ppp {
118 struct ppp_file file; /* stuff for read/write/poll 0 */
119 struct file *owner; /* file that owns this unit 48 */
120 struct list_head channels; /* list of attached channels 4c */
121 int n_channels; /* how many channels are attached 54 */
122 spinlock_t rlock; /* lock for receive side 58 */
123 spinlock_t wlock; /* lock for transmit side 5c */
124 int __percpu *xmit_recursion; /* xmit recursion detect */
125 int mru; /* max receive unit 60 */
126 unsigned int flags; /* control bits 64 */
127 unsigned int xstate; /* transmit state bits 68 */
128 unsigned int rstate; /* receive state bits 6c */
129 int debug; /* debug flags 70 */
130 struct slcompress *vj; /* state for VJ header compression */
131 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
132 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
133 struct compressor *xcomp; /* transmit packet compressor 8c */
134 void *xc_state; /* its internal state 90 */
135 struct compressor *rcomp; /* receive decompressor 94 */
136 void *rc_state; /* its internal state 98 */
137 unsigned long last_xmit; /* jiffies when last pkt sent 9c */
138 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
139 struct net_device *dev; /* network interface device a4 */
140 int closing; /* is device closing down? a8 */
141#ifdef CONFIG_PPP_MULTILINK
142 int nxchan; /* next channel to send something on */
143 u32 nxseq; /* next sequence number to send */
144 int mrru; /* MP: max reconst. receive unit */
145 u32 nextseq; /* MP: seq no of next packet */
146 u32 minseq; /* MP: min of most recent seqnos */
147 struct sk_buff_head mrq; /* MP: receive reconstruction queue */
148#endif /* CONFIG_PPP_MULTILINK */
149#ifdef CONFIG_PPP_FILTER
150 struct bpf_prog *pass_filter; /* filter for packets to pass */
151 struct bpf_prog *active_filter; /* filter for pkts to reset idle */
152#endif /* CONFIG_PPP_FILTER */
153 struct net *ppp_net; /* the net we belong to */
154 struct ppp_link_stats stats64; /* 64 bit network stats */
155};
156
157/*
158 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
159 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
160 * SC_MUST_COMP
161 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
162 * Bits in xstate: SC_COMP_RUN
163 */
164#define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
165 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
166 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
167
168/*
169 * Private data structure for each channel.
170 * This includes the data structure used for multilink.
171 */
172struct channel {
173 struct ppp_file file; /* stuff for read/write/poll */
174 struct list_head list; /* link in all/new_channels list */
175 struct ppp_channel *chan; /* public channel data structure */
176 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
177 spinlock_t downl; /* protects `chan', file.xq dequeue */
178 struct ppp *ppp; /* ppp unit we're connected to */
179 struct net *chan_net; /* the net channel belongs to */
180 struct list_head clist; /* link in list of channels per unit */
181 rwlock_t upl; /* protects `ppp' */
182#ifdef CONFIG_PPP_MULTILINK
183 u8 avail; /* flag used in multilink stuff */
184 u8 had_frag; /* >= 1 fragments have been sent */
185 u32 lastseq; /* MP: last sequence # received */
186 int speed; /* speed of the corresponding ppp channel*/
187#endif /* CONFIG_PPP_MULTILINK */
188};
189
190struct ppp_config {
191 struct file *file;
192 s32 unit;
193 bool ifname_is_set;
194};
195
196/*
197 * SMP locking issues:
198 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
199 * list and the ppp.n_channels field, you need to take both locks
200 * before you modify them.
201 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
202 * channel.downl.
203 */
204
205static DEFINE_MUTEX(ppp_mutex);
206static atomic_t ppp_unit_count = ATOMIC_INIT(0);
207static atomic_t channel_count = ATOMIC_INIT(0);
208
209/* per-net private data for this module */
210static unsigned int ppp_net_id __read_mostly;
211struct ppp_net {
212 /* units to ppp mapping */
213 struct idr units_idr;
214
215 /*
216 * all_ppp_mutex protects the units_idr mapping.
217 * It also ensures that finding a ppp unit in the units_idr
218 * map and updating its file.refcnt field is atomic.
219 */
220 struct mutex all_ppp_mutex;
221
222 /* channels */
223 struct list_head all_channels;
224 struct list_head new_channels;
225 int last_channel_index;
226
227 /*
228 * all_channels_lock protects all_channels and
229 * last_channel_index, and the atomicity of find
230 * a channel and updating its file.refcnt field.
231 */
232 spinlock_t all_channels_lock;
233};
234
235/* Get the PPP protocol number from a skb */
236#define PPP_PROTO(skb) get_unaligned_be16((skb)->data)
237
238/* We limit the length of ppp->file.rq to this (arbitrary) value */
239#define PPP_MAX_RQLEN 32
240
241/*
242 * Maximum number of multilink fragments queued up.
243 * This has to be large enough to cope with the maximum latency of
244 * the slowest channel relative to the others. Strictly it should
245 * depend on the number of channels and their characteristics.
246 */
247#define PPP_MP_MAX_QLEN 128
248
249/* Multilink header bits. */
250#define B 0x80 /* this fragment begins a packet */
251#define E 0x40 /* this fragment ends a packet */
252
253/* Compare multilink sequence numbers (assumed to be 32 bits wide) */
254#define seq_before(a, b) ((s32)((a) - (b)) < 0)
255#define seq_after(a, b) ((s32)((a) - (b)) > 0)
256
257/* Prototypes. */
258static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
259 struct file *file, unsigned int cmd, unsigned long arg);
260static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb);
261static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
262static void ppp_push(struct ppp *ppp);
263static void ppp_channel_push(struct channel *pch);
264static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
265 struct channel *pch);
266static void ppp_receive_error(struct ppp *ppp);
267static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
268static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
269 struct sk_buff *skb);
270#ifdef CONFIG_PPP_MULTILINK
271static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
272 struct channel *pch);
273static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
274static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
275static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
276#endif /* CONFIG_PPP_MULTILINK */
277static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
278static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
279static void ppp_ccp_closed(struct ppp *ppp);
280static struct compressor *find_compressor(int type);
281static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
282static int ppp_create_interface(struct net *net, struct file *file, int *unit);
283static void init_ppp_file(struct ppp_file *pf, int kind);
284static void ppp_destroy_interface(struct ppp *ppp);
285static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit);
286static struct channel *ppp_find_channel(struct ppp_net *pn, int unit);
287static int ppp_connect_channel(struct channel *pch, int unit);
288static int ppp_disconnect_channel(struct channel *pch);
289static void ppp_destroy_channel(struct channel *pch);
290static int unit_get(struct idr *p, void *ptr);
291static int unit_set(struct idr *p, void *ptr, int n);
292static void unit_put(struct idr *p, int n);
293static void *unit_find(struct idr *p, int n);
294static void ppp_setup(struct net_device *dev);
295
296static const struct net_device_ops ppp_netdev_ops;
297
298static struct class *ppp_class;
299
300/* per net-namespace data */
301static inline struct ppp_net *ppp_pernet(struct net *net)
302{
303 BUG_ON(!net);
304
305 return net_generic(net, ppp_net_id);
306}
307
308/* Translates a PPP protocol number to a NP index (NP == network protocol) */
309static inline int proto_to_npindex(int proto)
310{
311 switch (proto) {
312 case PPP_IP:
313 return NP_IP;
314 case PPP_IPV6:
315 return NP_IPV6;
316 case PPP_IPX:
317 return NP_IPX;
318 case PPP_AT:
319 return NP_AT;
320 case PPP_MPLS_UC:
321 return NP_MPLS_UC;
322 case PPP_MPLS_MC:
323 return NP_MPLS_MC;
324 }
325 return -EINVAL;
326}
327
328/* Translates an NP index into a PPP protocol number */
329static const int npindex_to_proto[NUM_NP] = {
330 PPP_IP,
331 PPP_IPV6,
332 PPP_IPX,
333 PPP_AT,
334 PPP_MPLS_UC,
335 PPP_MPLS_MC,
336};
337
338/* Translates an ethertype into an NP index */
339static inline int ethertype_to_npindex(int ethertype)
340{
341 switch (ethertype) {
342 case ETH_P_IP:
343 return NP_IP;
344 case ETH_P_IPV6:
345 return NP_IPV6;
346 case ETH_P_IPX:
347 return NP_IPX;
348 case ETH_P_PPPTALK:
349 case ETH_P_ATALK:
350 return NP_AT;
351 case ETH_P_MPLS_UC:
352 return NP_MPLS_UC;
353 case ETH_P_MPLS_MC:
354 return NP_MPLS_MC;
355 }
356 return -1;
357}
358
359/* Translates an NP index into an ethertype */
360static const int npindex_to_ethertype[NUM_NP] = {
361 ETH_P_IP,
362 ETH_P_IPV6,
363 ETH_P_IPX,
364 ETH_P_PPPTALK,
365 ETH_P_MPLS_UC,
366 ETH_P_MPLS_MC,
367};
368
369/*
370 * Locking shorthand.
371 */
372#define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
373#define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
374#define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
375#define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
376#define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
377 ppp_recv_lock(ppp); } while (0)
378#define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
379 ppp_xmit_unlock(ppp); } while (0)
380
381/*
382 * /dev/ppp device routines.
383 * The /dev/ppp device is used by pppd to control the ppp unit.
384 * It supports the read, write, ioctl and poll functions.
385 * Open instances of /dev/ppp can be in one of three states:
386 * unattached, attached to a ppp unit, or attached to a ppp channel.
387 */
388static int ppp_open(struct inode *inode, struct file *file)
389{
390 /*
391 * This could (should?) be enforced by the permissions on /dev/ppp.
392 */
393 if (!ns_capable(file->f_cred->user_ns, CAP_NET_ADMIN))
394 return -EPERM;
395 return 0;
396}
397
398static int ppp_release(struct inode *unused, struct file *file)
399{
400 struct ppp_file *pf = file->private_data;
401 struct ppp *ppp;
402
403 if (pf) {
404 file->private_data = NULL;
405 if (pf->kind == INTERFACE) {
406 ppp = PF_TO_PPP(pf);
407 rtnl_lock();
408 if (file == ppp->owner)
409 unregister_netdevice(ppp->dev);
410 rtnl_unlock();
411 }
412 if (refcount_dec_and_test(&pf->refcnt)) {
413 switch (pf->kind) {
414 case INTERFACE:
415 ppp_destroy_interface(PF_TO_PPP(pf));
416 break;
417 case CHANNEL:
418 ppp_destroy_channel(PF_TO_CHANNEL(pf));
419 break;
420 }
421 }
422 }
423 return 0;
424}
425
426static ssize_t ppp_read(struct file *file, char __user *buf,
427 size_t count, loff_t *ppos)
428{
429 struct ppp_file *pf = file->private_data;
430 DECLARE_WAITQUEUE(wait, current);
431 ssize_t ret;
432 struct sk_buff *skb = NULL;
433 struct iovec iov;
434 struct iov_iter to;
435
436 ret = count;
437
438 if (!pf)
439 return -ENXIO;
440 add_wait_queue(&pf->rwait, &wait);
441 for (;;) {
442 set_current_state(TASK_INTERRUPTIBLE);
443 skb = skb_dequeue(&pf->rq);
444 if (skb)
445 break;
446 ret = 0;
447 if (pf->dead)
448 break;
449 if (pf->kind == INTERFACE) {
450 /*
451 * Return 0 (EOF) on an interface that has no
452 * channels connected, unless it is looping
453 * network traffic (demand mode).
454 */
455 struct ppp *ppp = PF_TO_PPP(pf);
456
457 ppp_recv_lock(ppp);
458 if (ppp->n_channels == 0 &&
459 (ppp->flags & SC_LOOP_TRAFFIC) == 0) {
460 ppp_recv_unlock(ppp);
461 break;
462 }
463 ppp_recv_unlock(ppp);
464 }
465 ret = -EAGAIN;
466 if (file->f_flags & O_NONBLOCK)
467 break;
468 ret = -ERESTARTSYS;
469 if (signal_pending(current))
470 break;
471 schedule();
472 }
473 set_current_state(TASK_RUNNING);
474 remove_wait_queue(&pf->rwait, &wait);
475
476 if (!skb)
477 goto out;
478
479 ret = -EOVERFLOW;
480 if (skb->len > count)
481 goto outf;
482 ret = -EFAULT;
483 iov.iov_base = buf;
484 iov.iov_len = count;
485 iov_iter_init(&to, READ, &iov, 1, count);
486 if (skb_copy_datagram_iter(skb, 0, &to, skb->len))
487 goto outf;
488 ret = skb->len;
489
490 outf:
491 kfree_skb(skb);
492 out:
493 return ret;
494}
495
496static ssize_t ppp_write(struct file *file, const char __user *buf,
497 size_t count, loff_t *ppos)
498{
499 struct ppp_file *pf = file->private_data;
500 struct sk_buff *skb;
501 ssize_t ret;
502
503 if (!pf)
504 return -ENXIO;
505 ret = -ENOMEM;
506 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
507 if (!skb)
508 goto out;
509 skb_reserve(skb, pf->hdrlen);
510 ret = -EFAULT;
511 if (copy_from_user(skb_put(skb, count), buf, count)) {
512 kfree_skb(skb);
513 goto out;
514 }
515
516 switch (pf->kind) {
517 case INTERFACE:
518 ppp_xmit_process(PF_TO_PPP(pf), skb);
519 break;
520 case CHANNEL:
521 skb_queue_tail(&pf->xq, skb);
522 ppp_channel_push(PF_TO_CHANNEL(pf));
523 break;
524 }
525
526 ret = count;
527
528 out:
529 return ret;
530}
531
532/* No kernel lock - fine */
533static __poll_t ppp_poll(struct file *file, poll_table *wait)
534{
535 struct ppp_file *pf = file->private_data;
536 __poll_t mask;
537
538 if (!pf)
539 return 0;
540 poll_wait(file, &pf->rwait, wait);
541 mask = EPOLLOUT | EPOLLWRNORM;
542 if (skb_peek(&pf->rq))
543 mask |= EPOLLIN | EPOLLRDNORM;
544 if (pf->dead)
545 mask |= EPOLLHUP;
546 else if (pf->kind == INTERFACE) {
547 /* see comment in ppp_read */
548 struct ppp *ppp = PF_TO_PPP(pf);
549
550 ppp_recv_lock(ppp);
551 if (ppp->n_channels == 0 &&
552 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
553 mask |= EPOLLIN | EPOLLRDNORM;
554 ppp_recv_unlock(ppp);
555 }
556
557 return mask;
558}
559
560#ifdef CONFIG_PPP_FILTER
561static int get_filter(void __user *arg, struct sock_filter **p)
562{
563 struct sock_fprog uprog;
564 struct sock_filter *code = NULL;
565 int len;
566
567 if (copy_from_user(&uprog, arg, sizeof(uprog)))
568 return -EFAULT;
569
570 if (!uprog.len) {
571 *p = NULL;
572 return 0;
573 }
574
575 len = uprog.len * sizeof(struct sock_filter);
576 code = memdup_user(uprog.filter, len);
577 if (IS_ERR(code))
578 return PTR_ERR(code);
579
580 *p = code;
581 return uprog.len;
582}
583#endif /* CONFIG_PPP_FILTER */
584
585static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
586{
587 struct ppp_file *pf;
588 struct ppp *ppp;
589 int err = -EFAULT, val, val2, i;
590 struct ppp_idle idle;
591 struct npioctl npi;
592 int unit, cflags;
593 struct slcompress *vj;
594 void __user *argp = (void __user *)arg;
595 int __user *p = argp;
596
597 mutex_lock(&ppp_mutex);
598
599 pf = file->private_data;
600 if (!pf) {
601 err = ppp_unattached_ioctl(current->nsproxy->net_ns,
602 pf, file, cmd, arg);
603 goto out;
604 }
605
606 if (cmd == PPPIOCDETACH) {
607 /*
608 * PPPIOCDETACH is no longer supported as it was heavily broken,
609 * and is only known to have been used by pppd older than
610 * ppp-2.4.2 (released November 2003).
611 */
612 pr_warn_once("%s (%d) used obsolete PPPIOCDETACH ioctl\n",
613 current->comm, current->pid);
614 err = -EINVAL;
615 goto out;
616 }
617
618 if (pf->kind == CHANNEL) {
619 struct channel *pch;
620 struct ppp_channel *chan;
621
622 pch = PF_TO_CHANNEL(pf);
623
624 switch (cmd) {
625 case PPPIOCCONNECT:
626 if (get_user(unit, p))
627 break;
628 err = ppp_connect_channel(pch, unit);
629 break;
630
631 case PPPIOCDISCONN:
632 err = ppp_disconnect_channel(pch);
633 break;
634
635 default:
636 down_read(&pch->chan_sem);
637 chan = pch->chan;
638 err = -ENOTTY;
639 if (chan && chan->ops->ioctl)
640 err = chan->ops->ioctl(chan, cmd, arg);
641 up_read(&pch->chan_sem);
642 }
643 goto out;
644 }
645
646 if (pf->kind != INTERFACE) {
647 /* can't happen */
648 pr_err("PPP: not interface or channel??\n");
649 err = -EINVAL;
650 goto out;
651 }
652
653 ppp = PF_TO_PPP(pf);
654 switch (cmd) {
655 case PPPIOCSMRU:
656 if (get_user(val, p))
657 break;
658 ppp->mru = val;
659 err = 0;
660 break;
661
662 case PPPIOCSFLAGS:
663 if (get_user(val, p))
664 break;
665 ppp_lock(ppp);
666 cflags = ppp->flags & ~val;
667#ifdef CONFIG_PPP_MULTILINK
668 if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK))
669 ppp->nextseq = 0;
670#endif
671 ppp->flags = val & SC_FLAG_BITS;
672 ppp_unlock(ppp);
673 if (cflags & SC_CCP_OPEN)
674 ppp_ccp_closed(ppp);
675 err = 0;
676 break;
677
678 case PPPIOCGFLAGS:
679 val = ppp->flags | ppp->xstate | ppp->rstate;
680 if (put_user(val, p))
681 break;
682 err = 0;
683 break;
684
685 case PPPIOCSCOMPRESS:
686 err = ppp_set_compress(ppp, arg);
687 break;
688
689 case PPPIOCGUNIT:
690 if (put_user(ppp->file.index, p))
691 break;
692 err = 0;
693 break;
694
695 case PPPIOCSDEBUG:
696 if (get_user(val, p))
697 break;
698 ppp->debug = val;
699 err = 0;
700 break;
701
702 case PPPIOCGDEBUG:
703 if (put_user(ppp->debug, p))
704 break;
705 err = 0;
706 break;
707
708 case PPPIOCGIDLE:
709 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
710 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
711 if (copy_to_user(argp, &idle, sizeof(idle)))
712 break;
713 err = 0;
714 break;
715
716 case PPPIOCSMAXCID:
717 if (get_user(val, p))
718 break;
719 val2 = 15;
720 if ((val >> 16) != 0) {
721 val2 = val >> 16;
722 val &= 0xffff;
723 }
724 vj = slhc_init(val2+1, val+1);
725 if (IS_ERR(vj)) {
726 err = PTR_ERR(vj);
727 break;
728 }
729 ppp_lock(ppp);
730 if (ppp->vj)
731 slhc_free(ppp->vj);
732 ppp->vj = vj;
733 ppp_unlock(ppp);
734 err = 0;
735 break;
736
737 case PPPIOCGNPMODE:
738 case PPPIOCSNPMODE:
739 if (copy_from_user(&npi, argp, sizeof(npi)))
740 break;
741 err = proto_to_npindex(npi.protocol);
742 if (err < 0)
743 break;
744 i = err;
745 if (cmd == PPPIOCGNPMODE) {
746 err = -EFAULT;
747 npi.mode = ppp->npmode[i];
748 if (copy_to_user(argp, &npi, sizeof(npi)))
749 break;
750 } else {
751 ppp->npmode[i] = npi.mode;
752 /* we may be able to transmit more packets now (??) */
753 netif_wake_queue(ppp->dev);
754 }
755 err = 0;
756 break;
757
758#ifdef CONFIG_PPP_FILTER
759 case PPPIOCSPASS:
760 {
761 struct sock_filter *code;
762
763 err = get_filter(argp, &code);
764 if (err >= 0) {
765 struct bpf_prog *pass_filter = NULL;
766 struct sock_fprog_kern fprog = {
767 .len = err,
768 .filter = code,
769 };
770
771 err = 0;
772 if (fprog.filter)
773 err = bpf_prog_create(&pass_filter, &fprog);
774 if (!err) {
775 ppp_lock(ppp);
776 if (ppp->pass_filter)
777 bpf_prog_destroy(ppp->pass_filter);
778 ppp->pass_filter = pass_filter;
779 ppp_unlock(ppp);
780 }
781 kfree(code);
782 }
783 break;
784 }
785 case PPPIOCSACTIVE:
786 {
787 struct sock_filter *code;
788
789 err = get_filter(argp, &code);
790 if (err >= 0) {
791 struct bpf_prog *active_filter = NULL;
792 struct sock_fprog_kern fprog = {
793 .len = err,
794 .filter = code,
795 };
796
797 err = 0;
798 if (fprog.filter)
799 err = bpf_prog_create(&active_filter, &fprog);
800 if (!err) {
801 ppp_lock(ppp);
802 if (ppp->active_filter)
803 bpf_prog_destroy(ppp->active_filter);
804 ppp->active_filter = active_filter;
805 ppp_unlock(ppp);
806 }
807 kfree(code);
808 }
809 break;
810 }
811#endif /* CONFIG_PPP_FILTER */
812
813#ifdef CONFIG_PPP_MULTILINK
814 case PPPIOCSMRRU:
815 if (get_user(val, p))
816 break;
817 ppp_recv_lock(ppp);
818 ppp->mrru = val;
819 ppp_recv_unlock(ppp);
820 err = 0;
821 break;
822#endif /* CONFIG_PPP_MULTILINK */
823
824 default:
825 err = -ENOTTY;
826 }
827
828out:
829 mutex_unlock(&ppp_mutex);
830
831 return err;
832}
833
834static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
835 struct file *file, unsigned int cmd, unsigned long arg)
836{
837 int unit, err = -EFAULT;
838 struct ppp *ppp;
839 struct channel *chan;
840 struct ppp_net *pn;
841 int __user *p = (int __user *)arg;
842
843 switch (cmd) {
844 case PPPIOCNEWUNIT:
845 /* Create a new ppp unit */
846 if (get_user(unit, p))
847 break;
848 err = ppp_create_interface(net, file, &unit);
849 if (err < 0)
850 break;
851
852 err = -EFAULT;
853 if (put_user(unit, p))
854 break;
855 err = 0;
856 break;
857
858 case PPPIOCATTACH:
859 /* Attach to an existing ppp unit */
860 if (get_user(unit, p))
861 break;
862 err = -ENXIO;
863 pn = ppp_pernet(net);
864 mutex_lock(&pn->all_ppp_mutex);
865 ppp = ppp_find_unit(pn, unit);
866 if (ppp) {
867 refcount_inc(&ppp->file.refcnt);
868 file->private_data = &ppp->file;
869 err = 0;
870 }
871 mutex_unlock(&pn->all_ppp_mutex);
872 break;
873
874 case PPPIOCATTCHAN:
875 if (get_user(unit, p))
876 break;
877 err = -ENXIO;
878 pn = ppp_pernet(net);
879 spin_lock_bh(&pn->all_channels_lock);
880 chan = ppp_find_channel(pn, unit);
881 if (chan) {
882 refcount_inc(&chan->file.refcnt);
883 file->private_data = &chan->file;
884 err = 0;
885 }
886 spin_unlock_bh(&pn->all_channels_lock);
887 break;
888
889 default:
890 err = -ENOTTY;
891 }
892
893 return err;
894}
895
896static const struct file_operations ppp_device_fops = {
897 .owner = THIS_MODULE,
898 .read = ppp_read,
899 .write = ppp_write,
900 .poll = ppp_poll,
901 .unlocked_ioctl = ppp_ioctl,
902 .open = ppp_open,
903 .release = ppp_release,
904 .llseek = noop_llseek,
905};
906
907static __net_init int ppp_init_net(struct net *net)
908{
909 struct ppp_net *pn = net_generic(net, ppp_net_id);
910
911 idr_init(&pn->units_idr);
912 mutex_init(&pn->all_ppp_mutex);
913
914 INIT_LIST_HEAD(&pn->all_channels);
915 INIT_LIST_HEAD(&pn->new_channels);
916
917 spin_lock_init(&pn->all_channels_lock);
918
919 return 0;
920}
921
922static __net_exit void ppp_exit_net(struct net *net)
923{
924 struct ppp_net *pn = net_generic(net, ppp_net_id);
925 struct net_device *dev;
926 struct net_device *aux;
927 struct ppp *ppp;
928 LIST_HEAD(list);
929 int id;
930
931 rtnl_lock();
932 for_each_netdev_safe(net, dev, aux) {
933 if (dev->netdev_ops == &ppp_netdev_ops)
934 unregister_netdevice_queue(dev, &list);
935 }
936
937 idr_for_each_entry(&pn->units_idr, ppp, id)
938 /* Skip devices already unregistered by previous loop */
939 if (!net_eq(dev_net(ppp->dev), net))
940 unregister_netdevice_queue(ppp->dev, &list);
941
942 unregister_netdevice_many(&list);
943 rtnl_unlock();
944
945 mutex_destroy(&pn->all_ppp_mutex);
946 idr_destroy(&pn->units_idr);
947 WARN_ON_ONCE(!list_empty(&pn->all_channels));
948 WARN_ON_ONCE(!list_empty(&pn->new_channels));
949}
950
951static struct pernet_operations ppp_net_ops = {
952 .init = ppp_init_net,
953 .exit = ppp_exit_net,
954 .id = &ppp_net_id,
955 .size = sizeof(struct ppp_net),
956};
957
958static int ppp_unit_register(struct ppp *ppp, int unit, bool ifname_is_set)
959{
960 struct ppp_net *pn = ppp_pernet(ppp->ppp_net);
961 int ret;
962
963 mutex_lock(&pn->all_ppp_mutex);
964
965 if (unit < 0) {
966 ret = unit_get(&pn->units_idr, ppp);
967 if (ret < 0)
968 goto err;
969 } else {
970 /* Caller asked for a specific unit number. Fail with -EEXIST
971 * if unavailable. For backward compatibility, return -EEXIST
972 * too if idr allocation fails; this makes pppd retry without
973 * requesting a specific unit number.
974 */
975 if (unit_find(&pn->units_idr, unit)) {
976 ret = -EEXIST;
977 goto err;
978 }
979 ret = unit_set(&pn->units_idr, ppp, unit);
980 if (ret < 0) {
981 /* Rewrite error for backward compatibility */
982 ret = -EEXIST;
983 goto err;
984 }
985 }
986 ppp->file.index = ret;
987
988 if (!ifname_is_set)
989 snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ppp->file.index);
990
991 mutex_unlock(&pn->all_ppp_mutex);
992
993 ret = register_netdevice(ppp->dev);
994 if (ret < 0)
995 goto err_unit;
996
997 atomic_inc(&ppp_unit_count);
998
999 return 0;
1000
1001err_unit:
1002 mutex_lock(&pn->all_ppp_mutex);
1003 unit_put(&pn->units_idr, ppp->file.index);
1004err:
1005 mutex_unlock(&pn->all_ppp_mutex);
1006
1007 return ret;
1008}
1009
1010static int ppp_dev_configure(struct net *src_net, struct net_device *dev,
1011 const struct ppp_config *conf)
1012{
1013 struct ppp *ppp = netdev_priv(dev);
1014 int indx;
1015 int err;
1016 int cpu;
1017
1018 ppp->dev = dev;
1019 ppp->ppp_net = src_net;
1020 ppp->mru = PPP_MRU;
1021 ppp->owner = conf->file;
1022
1023 init_ppp_file(&ppp->file, INTERFACE);
1024 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
1025
1026 for (indx = 0; indx < NUM_NP; ++indx)
1027 ppp->npmode[indx] = NPMODE_PASS;
1028 INIT_LIST_HEAD(&ppp->channels);
1029 spin_lock_init(&ppp->rlock);
1030 spin_lock_init(&ppp->wlock);
1031
1032 ppp->xmit_recursion = alloc_percpu(int);
1033 if (!ppp->xmit_recursion) {
1034 err = -ENOMEM;
1035 goto err1;
1036 }
1037 for_each_possible_cpu(cpu)
1038 (*per_cpu_ptr(ppp->xmit_recursion, cpu)) = 0;
1039
1040#ifdef CONFIG_PPP_MULTILINK
1041 ppp->minseq = -1;
1042 skb_queue_head_init(&ppp->mrq);
1043#endif /* CONFIG_PPP_MULTILINK */
1044#ifdef CONFIG_PPP_FILTER
1045 ppp->pass_filter = NULL;
1046 ppp->active_filter = NULL;
1047#endif /* CONFIG_PPP_FILTER */
1048
1049 err = ppp_unit_register(ppp, conf->unit, conf->ifname_is_set);
1050 if (err < 0)
1051 goto err2;
1052
1053 conf->file->private_data = &ppp->file;
1054
1055 return 0;
1056err2:
1057 free_percpu(ppp->xmit_recursion);
1058err1:
1059 return err;
1060}
1061
1062static const struct nla_policy ppp_nl_policy[IFLA_PPP_MAX + 1] = {
1063 [IFLA_PPP_DEV_FD] = { .type = NLA_S32 },
1064};
1065
1066static int ppp_nl_validate(struct nlattr *tb[], struct nlattr *data[],
1067 struct netlink_ext_ack *extack)
1068{
1069 if (!data)
1070 return -EINVAL;
1071
1072 if (!data[IFLA_PPP_DEV_FD])
1073 return -EINVAL;
1074 if (nla_get_s32(data[IFLA_PPP_DEV_FD]) < 0)
1075 return -EBADF;
1076
1077 return 0;
1078}
1079
1080static int ppp_nl_newlink(struct net *src_net, struct net_device *dev,
1081 struct nlattr *tb[], struct nlattr *data[],
1082 struct netlink_ext_ack *extack)
1083{
1084 struct ppp_config conf = {
1085 .unit = -1,
1086 .ifname_is_set = true,
1087 };
1088 struct file *file;
1089 int err;
1090
1091 file = fget(nla_get_s32(data[IFLA_PPP_DEV_FD]));
1092 if (!file)
1093 return -EBADF;
1094
1095 /* rtnl_lock is already held here, but ppp_create_interface() locks
1096 * ppp_mutex before holding rtnl_lock. Using mutex_trylock() avoids
1097 * possible deadlock due to lock order inversion, at the cost of
1098 * pushing the problem back to userspace.
1099 */
1100 if (!mutex_trylock(&ppp_mutex)) {
1101 err = -EBUSY;
1102 goto out;
1103 }
1104
1105 if (file->f_op != &ppp_device_fops || file->private_data) {
1106 err = -EBADF;
1107 goto out_unlock;
1108 }
1109
1110 conf.file = file;
1111
1112 /* Don't use device name generated by the rtnetlink layer when ifname
1113 * isn't specified. Let ppp_dev_configure() set the device name using
1114 * the PPP unit identifer as suffix (i.e. ppp<unit_id>). This allows
1115 * userspace to infer the device name using to the PPPIOCGUNIT ioctl.
1116 */
1117 if (!tb[IFLA_IFNAME])
1118 conf.ifname_is_set = false;
1119
1120 err = ppp_dev_configure(src_net, dev, &conf);
1121
1122out_unlock:
1123 mutex_unlock(&ppp_mutex);
1124out:
1125 fput(file);
1126
1127 return err;
1128}
1129
1130static void ppp_nl_dellink(struct net_device *dev, struct list_head *head)
1131{
1132 unregister_netdevice_queue(dev, head);
1133}
1134
1135static size_t ppp_nl_get_size(const struct net_device *dev)
1136{
1137 return 0;
1138}
1139
1140static int ppp_nl_fill_info(struct sk_buff *skb, const struct net_device *dev)
1141{
1142 return 0;
1143}
1144
1145static struct net *ppp_nl_get_link_net(const struct net_device *dev)
1146{
1147 struct ppp *ppp = netdev_priv(dev);
1148
1149 return ppp->ppp_net;
1150}
1151
1152static struct rtnl_link_ops ppp_link_ops __read_mostly = {
1153 .kind = "ppp",
1154 .maxtype = IFLA_PPP_MAX,
1155 .policy = ppp_nl_policy,
1156 .priv_size = sizeof(struct ppp),
1157 .setup = ppp_setup,
1158 .validate = ppp_nl_validate,
1159 .newlink = ppp_nl_newlink,
1160 .dellink = ppp_nl_dellink,
1161 .get_size = ppp_nl_get_size,
1162 .fill_info = ppp_nl_fill_info,
1163 .get_link_net = ppp_nl_get_link_net,
1164};
1165
1166#define PPP_MAJOR 108
1167
1168/* Called at boot time if ppp is compiled into the kernel,
1169 or at module load time (from init_module) if compiled as a module. */
1170static int __init ppp_init(void)
1171{
1172 int err;
1173
1174 pr_info("PPP generic driver version " PPP_VERSION "\n");
1175
1176 err = register_pernet_device(&ppp_net_ops);
1177 if (err) {
1178 pr_err("failed to register PPP pernet device (%d)\n", err);
1179 goto out;
1180 }
1181
1182 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
1183 if (err) {
1184 pr_err("failed to register PPP device (%d)\n", err);
1185 goto out_net;
1186 }
1187
1188 ppp_class = class_create(THIS_MODULE, "ppp");
1189 if (IS_ERR(ppp_class)) {
1190 err = PTR_ERR(ppp_class);
1191 goto out_chrdev;
1192 }
1193
1194 err = rtnl_link_register(&ppp_link_ops);
1195 if (err) {
1196 pr_err("failed to register rtnetlink PPP handler\n");
1197 goto out_class;
1198 }
1199
1200 /* not a big deal if we fail here :-) */
1201 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
1202
1203 return 0;
1204
1205out_class:
1206 class_destroy(ppp_class);
1207out_chrdev:
1208 unregister_chrdev(PPP_MAJOR, "ppp");
1209out_net:
1210 unregister_pernet_device(&ppp_net_ops);
1211out:
1212 return err;
1213}
1214
1215/*
1216 * Network interface unit routines.
1217 */
1218static netdev_tx_t
1219ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
1220{
1221 struct ppp *ppp = netdev_priv(dev);
1222 int npi, proto;
1223 unsigned char *pp;
1224
1225 npi = ethertype_to_npindex(ntohs(skb->protocol));
1226 if (npi < 0)
1227 goto outf;
1228
1229 /* Drop, accept or reject the packet */
1230 switch (ppp->npmode[npi]) {
1231 case NPMODE_PASS:
1232 break;
1233 case NPMODE_QUEUE:
1234 /* it would be nice to have a way to tell the network
1235 system to queue this one up for later. */
1236 goto outf;
1237 case NPMODE_DROP:
1238 case NPMODE_ERROR:
1239 goto outf;
1240 }
1241
1242 /* Put the 2-byte PPP protocol number on the front,
1243 making sure there is room for the address and control fields. */
1244 if (skb_cow_head(skb, PPP_HDRLEN))
1245 goto outf;
1246
1247 pp = skb_push(skb, 2);
1248 proto = npindex_to_proto[npi];
1249 put_unaligned_be16(proto, pp);
1250
1251 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, dev_net(dev)));
1252 ppp_xmit_process(ppp, skb);
1253
1254 return NETDEV_TX_OK;
1255
1256 outf:
1257 kfree_skb(skb);
1258 ++dev->stats.tx_dropped;
1259 return NETDEV_TX_OK;
1260}
1261
1262static int
1263ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1264{
1265 struct ppp *ppp = netdev_priv(dev);
1266 int err = -EFAULT;
1267 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
1268 struct ppp_stats stats;
1269 struct ppp_comp_stats cstats;
1270 char *vers;
1271
1272 switch (cmd) {
1273 case SIOCGPPPSTATS:
1274 ppp_get_stats(ppp, &stats);
1275 if (copy_to_user(addr, &stats, sizeof(stats)))
1276 break;
1277 err = 0;
1278 break;
1279
1280 case SIOCGPPPCSTATS:
1281 memset(&cstats, 0, sizeof(cstats));
1282 if (ppp->xc_state)
1283 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
1284 if (ppp->rc_state)
1285 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
1286 if (copy_to_user(addr, &cstats, sizeof(cstats)))
1287 break;
1288 err = 0;
1289 break;
1290
1291 case SIOCGPPPVER:
1292 vers = PPP_VERSION;
1293 if (copy_to_user(addr, vers, strlen(vers) + 1))
1294 break;
1295 err = 0;
1296 break;
1297
1298 default:
1299 err = -EINVAL;
1300 }
1301
1302 return err;
1303}
1304
1305static void
1306ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64)
1307{
1308 struct ppp *ppp = netdev_priv(dev);
1309
1310 ppp_recv_lock(ppp);
1311 stats64->rx_packets = ppp->stats64.rx_packets;
1312 stats64->rx_bytes = ppp->stats64.rx_bytes;
1313 ppp_recv_unlock(ppp);
1314
1315 ppp_xmit_lock(ppp);
1316 stats64->tx_packets = ppp->stats64.tx_packets;
1317 stats64->tx_bytes = ppp->stats64.tx_bytes;
1318 ppp_xmit_unlock(ppp);
1319
1320 stats64->rx_errors = dev->stats.rx_errors;
1321 stats64->tx_errors = dev->stats.tx_errors;
1322 stats64->rx_dropped = dev->stats.rx_dropped;
1323 stats64->tx_dropped = dev->stats.tx_dropped;
1324 stats64->rx_length_errors = dev->stats.rx_length_errors;
1325}
1326
1327static int ppp_dev_init(struct net_device *dev)
1328{
1329 struct ppp *ppp;
1330
1331 netdev_lockdep_set_classes(dev);
1332
1333 ppp = netdev_priv(dev);
1334 /* Let the netdevice take a reference on the ppp file. This ensures
1335 * that ppp_destroy_interface() won't run before the device gets
1336 * unregistered.
1337 */
1338 refcount_inc(&ppp->file.refcnt);
1339
1340 return 0;
1341}
1342
1343static void ppp_dev_uninit(struct net_device *dev)
1344{
1345 struct ppp *ppp = netdev_priv(dev);
1346 struct ppp_net *pn = ppp_pernet(ppp->ppp_net);
1347
1348 ppp_lock(ppp);
1349 ppp->closing = 1;
1350 ppp_unlock(ppp);
1351
1352 mutex_lock(&pn->all_ppp_mutex);
1353 unit_put(&pn->units_idr, ppp->file.index);
1354 mutex_unlock(&pn->all_ppp_mutex);
1355
1356 ppp->owner = NULL;
1357
1358 ppp->file.dead = 1;
1359 wake_up_interruptible(&ppp->file.rwait);
1360}
1361
1362static void ppp_dev_priv_destructor(struct net_device *dev)
1363{
1364 struct ppp *ppp;
1365
1366 ppp = netdev_priv(dev);
1367 if (refcount_dec_and_test(&ppp->file.refcnt))
1368 ppp_destroy_interface(ppp);
1369}
1370
1371static const struct net_device_ops ppp_netdev_ops = {
1372 .ndo_init = ppp_dev_init,
1373 .ndo_uninit = ppp_dev_uninit,
1374 .ndo_start_xmit = ppp_start_xmit,
1375 .ndo_do_ioctl = ppp_net_ioctl,
1376 .ndo_get_stats64 = ppp_get_stats64,
1377};
1378
1379static struct device_type ppp_type = {
1380 .name = "ppp",
1381};
1382
1383static void ppp_setup(struct net_device *dev)
1384{
1385 dev->netdev_ops = &ppp_netdev_ops;
1386 SET_NETDEV_DEVTYPE(dev, &ppp_type);
1387
1388 dev->features |= NETIF_F_LLTX;
1389
1390 dev->hard_header_len = PPP_HDRLEN;
1391 dev->mtu = PPP_MRU;
1392 dev->addr_len = 0;
1393 dev->tx_queue_len = 3;
1394 dev->type = ARPHRD_PPP;
1395 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1396 dev->priv_destructor = ppp_dev_priv_destructor;
1397 netif_keep_dst(dev);
1398}
1399
1400/*
1401 * Transmit-side routines.
1402 */
1403
1404/* Called to do any work queued up on the transmit side that can now be done */
1405static void __ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb)
1406{
1407 ppp_xmit_lock(ppp);
1408 if (!ppp->closing) {
1409 ppp_push(ppp);
1410
1411 if (skb)
1412 skb_queue_tail(&ppp->file.xq, skb);
1413 while (!ppp->xmit_pending &&
1414 (skb = skb_dequeue(&ppp->file.xq)))
1415 ppp_send_frame(ppp, skb);
1416 /* If there's no work left to do, tell the core net
1417 code that we can accept some more. */
1418 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1419 netif_wake_queue(ppp->dev);
1420 else
1421 netif_stop_queue(ppp->dev);
1422 }
1423 ppp_xmit_unlock(ppp);
1424}
1425
1426static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb)
1427{
1428 local_bh_disable();
1429
1430 if (unlikely(*this_cpu_ptr(ppp->xmit_recursion)))
1431 goto err;
1432
1433 (*this_cpu_ptr(ppp->xmit_recursion))++;
1434 __ppp_xmit_process(ppp, skb);
1435 (*this_cpu_ptr(ppp->xmit_recursion))--;
1436
1437 local_bh_enable();
1438
1439 return;
1440
1441err:
1442 local_bh_enable();
1443
1444 kfree_skb(skb);
1445
1446 if (net_ratelimit())
1447 netdev_err(ppp->dev, "recursion detected\n");
1448}
1449
1450static inline struct sk_buff *
1451pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1452{
1453 struct sk_buff *new_skb;
1454 int len;
1455 int new_skb_size = ppp->dev->mtu +
1456 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1457 int compressor_skb_size = ppp->dev->mtu +
1458 ppp->xcomp->comp_extra + PPP_HDRLEN;
1459 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1460 if (!new_skb) {
1461 if (net_ratelimit())
1462 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n");
1463 return NULL;
1464 }
1465 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1466 skb_reserve(new_skb,
1467 ppp->dev->hard_header_len - PPP_HDRLEN);
1468
1469 /* compressor still expects A/C bytes in hdr */
1470 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1471 new_skb->data, skb->len + 2,
1472 compressor_skb_size);
1473 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1474 consume_skb(skb);
1475 skb = new_skb;
1476 skb_put(skb, len);
1477 skb_pull(skb, 2); /* pull off A/C bytes */
1478 } else if (len == 0) {
1479 /* didn't compress, or CCP not up yet */
1480 consume_skb(new_skb);
1481 new_skb = skb;
1482 } else {
1483 /*
1484 * (len < 0)
1485 * MPPE requires that we do not send unencrypted
1486 * frames. The compressor will return -1 if we
1487 * should drop the frame. We cannot simply test
1488 * the compress_proto because MPPE and MPPC share
1489 * the same number.
1490 */
1491 if (net_ratelimit())
1492 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n");
1493 kfree_skb(skb);
1494 consume_skb(new_skb);
1495 new_skb = NULL;
1496 }
1497 return new_skb;
1498}
1499
1500/*
1501 * Compress and send a frame.
1502 * The caller should have locked the xmit path,
1503 * and xmit_pending should be 0.
1504 */
1505static void
1506ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1507{
1508 int proto = PPP_PROTO(skb);
1509 struct sk_buff *new_skb;
1510 int len;
1511 unsigned char *cp;
1512
1513 if (proto < 0x8000) {
1514#ifdef CONFIG_PPP_FILTER
1515 /* check if we should pass this packet */
1516 /* the filter instructions are constructed assuming
1517 a four-byte PPP header on each packet */
1518 *(u8 *)skb_push(skb, 2) = 1;
1519 if (ppp->pass_filter &&
1520 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
1521 if (ppp->debug & 1)
1522 netdev_printk(KERN_DEBUG, ppp->dev,
1523 "PPP: outbound frame "
1524 "not passed\n");
1525 kfree_skb(skb);
1526 return;
1527 }
1528 /* if this packet passes the active filter, record the time */
1529 if (!(ppp->active_filter &&
1530 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
1531 ppp->last_xmit = jiffies;
1532 skb_pull(skb, 2);
1533#else
1534 /* for data packets, record the time */
1535 ppp->last_xmit = jiffies;
1536#endif /* CONFIG_PPP_FILTER */
1537 }
1538
1539 ++ppp->stats64.tx_packets;
1540 ppp->stats64.tx_bytes += skb->len - 2;
1541
1542 switch (proto) {
1543 case PPP_IP:
1544 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1545 break;
1546 /* try to do VJ TCP header compression */
1547 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1548 GFP_ATOMIC);
1549 if (!new_skb) {
1550 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n");
1551 goto drop;
1552 }
1553 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1554 cp = skb->data + 2;
1555 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1556 new_skb->data + 2, &cp,
1557 !(ppp->flags & SC_NO_TCP_CCID));
1558 if (cp == skb->data + 2) {
1559 /* didn't compress */
1560 consume_skb(new_skb);
1561 } else {
1562 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1563 proto = PPP_VJC_COMP;
1564 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1565 } else {
1566 proto = PPP_VJC_UNCOMP;
1567 cp[0] = skb->data[2];
1568 }
1569 consume_skb(skb);
1570 skb = new_skb;
1571 cp = skb_put(skb, len + 2);
1572 cp[0] = 0;
1573 cp[1] = proto;
1574 }
1575 break;
1576
1577 case PPP_CCP:
1578 /* peek at outbound CCP frames */
1579 ppp_ccp_peek(ppp, skb, 0);
1580 break;
1581 }
1582
1583 /* try to do packet compression */
1584 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state &&
1585 proto != PPP_LCP && proto != PPP_CCP) {
1586 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1587 if (net_ratelimit())
1588 netdev_err(ppp->dev,
1589 "ppp: compression required but "
1590 "down - pkt dropped.\n");
1591 goto drop;
1592 }
1593 skb = pad_compress_skb(ppp, skb);
1594 if (!skb)
1595 goto drop;
1596 }
1597
1598 /*
1599 * If we are waiting for traffic (demand dialling),
1600 * queue it up for pppd to receive.
1601 */
1602 if (ppp->flags & SC_LOOP_TRAFFIC) {
1603 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1604 goto drop;
1605 skb_queue_tail(&ppp->file.rq, skb);
1606 wake_up_interruptible(&ppp->file.rwait);
1607 return;
1608 }
1609
1610 ppp->xmit_pending = skb;
1611 ppp_push(ppp);
1612 return;
1613
1614 drop:
1615 kfree_skb(skb);
1616 ++ppp->dev->stats.tx_errors;
1617}
1618
1619/*
1620 * Try to send the frame in xmit_pending.
1621 * The caller should have the xmit path locked.
1622 */
1623static void
1624ppp_push(struct ppp *ppp)
1625{
1626 struct list_head *list;
1627 struct channel *pch;
1628 struct sk_buff *skb = ppp->xmit_pending;
1629
1630 if (!skb)
1631 return;
1632
1633 list = &ppp->channels;
1634 if (list_empty(list)) {
1635 /* nowhere to send the packet, just drop it */
1636 ppp->xmit_pending = NULL;
1637 kfree_skb(skb);
1638 return;
1639 }
1640
1641 if ((ppp->flags & SC_MULTILINK) == 0) {
1642 /* not doing multilink: send it down the first channel */
1643 list = list->next;
1644 pch = list_entry(list, struct channel, clist);
1645
1646 spin_lock(&pch->downl);
1647 if (pch->chan) {
1648 if (pch->chan->ops->start_xmit(pch->chan, skb))
1649 ppp->xmit_pending = NULL;
1650 } else {
1651 /* channel got unregistered */
1652 kfree_skb(skb);
1653 ppp->xmit_pending = NULL;
1654 }
1655 spin_unlock(&pch->downl);
1656 return;
1657 }
1658
1659#ifdef CONFIG_PPP_MULTILINK
1660 /* Multilink: fragment the packet over as many links
1661 as can take the packet at the moment. */
1662 if (!ppp_mp_explode(ppp, skb))
1663 return;
1664#endif /* CONFIG_PPP_MULTILINK */
1665
1666 ppp->xmit_pending = NULL;
1667 kfree_skb(skb);
1668}
1669
1670#ifdef CONFIG_PPP_MULTILINK
1671static bool mp_protocol_compress __read_mostly = true;
1672module_param(mp_protocol_compress, bool, 0644);
1673MODULE_PARM_DESC(mp_protocol_compress,
1674 "compress protocol id in multilink fragments");
1675
1676/*
1677 * Divide a packet to be transmitted into fragments and
1678 * send them out the individual links.
1679 */
1680static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1681{
1682 int len, totlen;
1683 int i, bits, hdrlen, mtu;
1684 int flen;
1685 int navail, nfree, nzero;
1686 int nbigger;
1687 int totspeed;
1688 int totfree;
1689 unsigned char *p, *q;
1690 struct list_head *list;
1691 struct channel *pch;
1692 struct sk_buff *frag;
1693 struct ppp_channel *chan;
1694
1695 totspeed = 0; /*total bitrate of the bundle*/
1696 nfree = 0; /* # channels which have no packet already queued */
1697 navail = 0; /* total # of usable channels (not deregistered) */
1698 nzero = 0; /* number of channels with zero speed associated*/
1699 totfree = 0; /*total # of channels available and
1700 *having no queued packets before
1701 *starting the fragmentation*/
1702
1703 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1704 i = 0;
1705 list_for_each_entry(pch, &ppp->channels, clist) {
1706 if (pch->chan) {
1707 pch->avail = 1;
1708 navail++;
1709 pch->speed = pch->chan->speed;
1710 } else {
1711 pch->avail = 0;
1712 }
1713 if (pch->avail) {
1714 if (skb_queue_empty(&pch->file.xq) ||
1715 !pch->had_frag) {
1716 if (pch->speed == 0)
1717 nzero++;
1718 else
1719 totspeed += pch->speed;
1720
1721 pch->avail = 2;
1722 ++nfree;
1723 ++totfree;
1724 }
1725 if (!pch->had_frag && i < ppp->nxchan)
1726 ppp->nxchan = i;
1727 }
1728 ++i;
1729 }
1730 /*
1731 * Don't start sending this packet unless at least half of
1732 * the channels are free. This gives much better TCP
1733 * performance if we have a lot of channels.
1734 */
1735 if (nfree == 0 || nfree < navail / 2)
1736 return 0; /* can't take now, leave it in xmit_pending */
1737
1738 /* Do protocol field compression */
1739 p = skb->data;
1740 len = skb->len;
1741 if (*p == 0 && mp_protocol_compress) {
1742 ++p;
1743 --len;
1744 }
1745
1746 totlen = len;
1747 nbigger = len % nfree;
1748
1749 /* skip to the channel after the one we last used
1750 and start at that one */
1751 list = &ppp->channels;
1752 for (i = 0; i < ppp->nxchan; ++i) {
1753 list = list->next;
1754 if (list == &ppp->channels) {
1755 i = 0;
1756 break;
1757 }
1758 }
1759
1760 /* create a fragment for each channel */
1761 bits = B;
1762 while (len > 0) {
1763 list = list->next;
1764 if (list == &ppp->channels) {
1765 i = 0;
1766 continue;
1767 }
1768 pch = list_entry(list, struct channel, clist);
1769 ++i;
1770 if (!pch->avail)
1771 continue;
1772
1773 /*
1774 * Skip this channel if it has a fragment pending already and
1775 * we haven't given a fragment to all of the free channels.
1776 */
1777 if (pch->avail == 1) {
1778 if (nfree > 0)
1779 continue;
1780 } else {
1781 pch->avail = 1;
1782 }
1783
1784 /* check the channel's mtu and whether it is still attached. */
1785 spin_lock(&pch->downl);
1786 if (pch->chan == NULL) {
1787 /* can't use this channel, it's being deregistered */
1788 if (pch->speed == 0)
1789 nzero--;
1790 else
1791 totspeed -= pch->speed;
1792
1793 spin_unlock(&pch->downl);
1794 pch->avail = 0;
1795 totlen = len;
1796 totfree--;
1797 nfree--;
1798 if (--navail == 0)
1799 break;
1800 continue;
1801 }
1802
1803 /*
1804 *if the channel speed is not set divide
1805 *the packet evenly among the free channels;
1806 *otherwise divide it according to the speed
1807 *of the channel we are going to transmit on
1808 */
1809 flen = len;
1810 if (nfree > 0) {
1811 if (pch->speed == 0) {
1812 flen = len/nfree;
1813 if (nbigger > 0) {
1814 flen++;
1815 nbigger--;
1816 }
1817 } else {
1818 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
1819 ((totspeed*totfree)/pch->speed)) - hdrlen;
1820 if (nbigger > 0) {
1821 flen += ((totfree - nzero)*pch->speed)/totspeed;
1822 nbigger -= ((totfree - nzero)*pch->speed)/
1823 totspeed;
1824 }
1825 }
1826 nfree--;
1827 }
1828
1829 /*
1830 *check if we are on the last channel or
1831 *we exceded the length of the data to
1832 *fragment
1833 */
1834 if ((nfree <= 0) || (flen > len))
1835 flen = len;
1836 /*
1837 *it is not worth to tx on slow channels:
1838 *in that case from the resulting flen according to the
1839 *above formula will be equal or less than zero.
1840 *Skip the channel in this case
1841 */
1842 if (flen <= 0) {
1843 pch->avail = 2;
1844 spin_unlock(&pch->downl);
1845 continue;
1846 }
1847
1848 /*
1849 * hdrlen includes the 2-byte PPP protocol field, but the
1850 * MTU counts only the payload excluding the protocol field.
1851 * (RFC1661 Section 2)
1852 */
1853 mtu = pch->chan->mtu - (hdrlen - 2);
1854 if (mtu < 4)
1855 mtu = 4;
1856 if (flen > mtu)
1857 flen = mtu;
1858 if (flen == len)
1859 bits |= E;
1860 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1861 if (!frag)
1862 goto noskb;
1863 q = skb_put(frag, flen + hdrlen);
1864
1865 /* make the MP header */
1866 put_unaligned_be16(PPP_MP, q);
1867 if (ppp->flags & SC_MP_XSHORTSEQ) {
1868 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1869 q[3] = ppp->nxseq;
1870 } else {
1871 q[2] = bits;
1872 q[3] = ppp->nxseq >> 16;
1873 q[4] = ppp->nxseq >> 8;
1874 q[5] = ppp->nxseq;
1875 }
1876
1877 memcpy(q + hdrlen, p, flen);
1878
1879 /* try to send it down the channel */
1880 chan = pch->chan;
1881 if (!skb_queue_empty(&pch->file.xq) ||
1882 !chan->ops->start_xmit(chan, frag))
1883 skb_queue_tail(&pch->file.xq, frag);
1884 pch->had_frag = 1;
1885 p += flen;
1886 len -= flen;
1887 ++ppp->nxseq;
1888 bits = 0;
1889 spin_unlock(&pch->downl);
1890 }
1891 ppp->nxchan = i;
1892
1893 return 1;
1894
1895 noskb:
1896 spin_unlock(&pch->downl);
1897 if (ppp->debug & 1)
1898 netdev_err(ppp->dev, "PPP: no memory (fragment)\n");
1899 ++ppp->dev->stats.tx_errors;
1900 ++ppp->nxseq;
1901 return 1; /* abandon the frame */
1902}
1903#endif /* CONFIG_PPP_MULTILINK */
1904
1905/* Try to send data out on a channel */
1906static void __ppp_channel_push(struct channel *pch)
1907{
1908 struct sk_buff *skb;
1909 struct ppp *ppp;
1910
1911 spin_lock(&pch->downl);
1912 if (pch->chan) {
1913 while (!skb_queue_empty(&pch->file.xq)) {
1914 skb = skb_dequeue(&pch->file.xq);
1915 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1916 /* put the packet back and try again later */
1917 skb_queue_head(&pch->file.xq, skb);
1918 break;
1919 }
1920 }
1921 } else {
1922 /* channel got deregistered */
1923 skb_queue_purge(&pch->file.xq);
1924 }
1925 spin_unlock(&pch->downl);
1926 /* see if there is anything from the attached unit to be sent */
1927 if (skb_queue_empty(&pch->file.xq)) {
1928 ppp = pch->ppp;
1929 if (ppp)
1930 __ppp_xmit_process(ppp, NULL);
1931 }
1932}
1933
1934static void ppp_channel_push(struct channel *pch)
1935{
1936 read_lock_bh(&pch->upl);
1937 if (pch->ppp) {
1938 (*this_cpu_ptr(pch->ppp->xmit_recursion))++;
1939 __ppp_channel_push(pch);
1940 (*this_cpu_ptr(pch->ppp->xmit_recursion))--;
1941 } else {
1942 __ppp_channel_push(pch);
1943 }
1944 read_unlock_bh(&pch->upl);
1945}
1946
1947/*
1948 * Receive-side routines.
1949 */
1950
1951struct ppp_mp_skb_parm {
1952 u32 sequence;
1953 u8 BEbits;
1954};
1955#define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb))
1956
1957static inline void
1958ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1959{
1960 ppp_recv_lock(ppp);
1961 if (!ppp->closing)
1962 ppp_receive_frame(ppp, skb, pch);
1963 else
1964 kfree_skb(skb);
1965 ppp_recv_unlock(ppp);
1966}
1967
1968void
1969ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1970{
1971 struct channel *pch = chan->ppp;
1972 int proto;
1973
1974 if (!pch) {
1975 kfree_skb(skb);
1976 return;
1977 }
1978
1979 read_lock_bh(&pch->upl);
1980 if (!pskb_may_pull(skb, 2)) {
1981 kfree_skb(skb);
1982 if (pch->ppp) {
1983 ++pch->ppp->dev->stats.rx_length_errors;
1984 ppp_receive_error(pch->ppp);
1985 }
1986 goto done;
1987 }
1988
1989 proto = PPP_PROTO(skb);
1990 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1991 /* put it on the channel queue */
1992 skb_queue_tail(&pch->file.rq, skb);
1993 /* drop old frames if queue too long */
1994 while (pch->file.rq.qlen > PPP_MAX_RQLEN &&
1995 (skb = skb_dequeue(&pch->file.rq)))
1996 kfree_skb(skb);
1997 wake_up_interruptible(&pch->file.rwait);
1998 } else {
1999 ppp_do_recv(pch->ppp, skb, pch);
2000 }
2001
2002done:
2003 read_unlock_bh(&pch->upl);
2004}
2005
2006/* Put a 0-length skb in the receive queue as an error indication */
2007void
2008ppp_input_error(struct ppp_channel *chan, int code)
2009{
2010 struct channel *pch = chan->ppp;
2011 struct sk_buff *skb;
2012
2013 if (!pch)
2014 return;
2015
2016 read_lock_bh(&pch->upl);
2017 if (pch->ppp) {
2018 skb = alloc_skb(0, GFP_ATOMIC);
2019 if (skb) {
2020 skb->len = 0; /* probably unnecessary */
2021 skb->cb[0] = code;
2022 ppp_do_recv(pch->ppp, skb, pch);
2023 }
2024 }
2025 read_unlock_bh(&pch->upl);
2026}
2027
2028/*
2029 * We come in here to process a received frame.
2030 * The receive side of the ppp unit is locked.
2031 */
2032static void
2033ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
2034{
2035 /* note: a 0-length skb is used as an error indication */
2036 if (skb->len > 0) {
2037 skb_checksum_complete_unset(skb);
2038#ifdef CONFIG_PPP_MULTILINK
2039 /* XXX do channel-level decompression here */
2040 if (PPP_PROTO(skb) == PPP_MP)
2041 ppp_receive_mp_frame(ppp, skb, pch);
2042 else
2043#endif /* CONFIG_PPP_MULTILINK */
2044 ppp_receive_nonmp_frame(ppp, skb);
2045 } else {
2046 kfree_skb(skb);
2047 ppp_receive_error(ppp);
2048 }
2049}
2050
2051static void
2052ppp_receive_error(struct ppp *ppp)
2053{
2054 ++ppp->dev->stats.rx_errors;
2055 if (ppp->vj)
2056 slhc_toss(ppp->vj);
2057}
2058
2059static void
2060ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
2061{
2062 struct sk_buff *ns;
2063 int proto, len, npi;
2064
2065 /*
2066 * Decompress the frame, if compressed.
2067 * Note that some decompressors need to see uncompressed frames
2068 * that come in as well as compressed frames.
2069 */
2070 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) &&
2071 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
2072 skb = ppp_decompress_frame(ppp, skb);
2073
2074 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
2075 goto err;
2076
2077 proto = PPP_PROTO(skb);
2078 switch (proto) {
2079 case PPP_VJC_COMP:
2080 /* decompress VJ compressed packets */
2081 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
2082 goto err;
2083
2084 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
2085 /* copy to a new sk_buff with more tailroom */
2086 ns = dev_alloc_skb(skb->len + 128);
2087 if (!ns) {
2088 netdev_err(ppp->dev, "PPP: no memory "
2089 "(VJ decomp)\n");
2090 goto err;
2091 }
2092 skb_reserve(ns, 2);
2093 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
2094 consume_skb(skb);
2095 skb = ns;
2096 }
2097 else
2098 skb->ip_summed = CHECKSUM_NONE;
2099
2100 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
2101 if (len <= 0) {
2102 netdev_printk(KERN_DEBUG, ppp->dev,
2103 "PPP: VJ decompression error\n");
2104 goto err;
2105 }
2106 len += 2;
2107 if (len > skb->len)
2108 skb_put(skb, len - skb->len);
2109 else if (len < skb->len)
2110 skb_trim(skb, len);
2111 proto = PPP_IP;
2112 break;
2113
2114 case PPP_VJC_UNCOMP:
2115 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
2116 goto err;
2117
2118 /* Until we fix the decompressor need to make sure
2119 * data portion is linear.
2120 */
2121 if (!pskb_may_pull(skb, skb->len))
2122 goto err;
2123
2124 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
2125 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n");
2126 goto err;
2127 }
2128 proto = PPP_IP;
2129 break;
2130
2131 case PPP_CCP:
2132 ppp_ccp_peek(ppp, skb, 1);
2133 break;
2134 }
2135
2136 ++ppp->stats64.rx_packets;
2137 ppp->stats64.rx_bytes += skb->len - 2;
2138
2139 npi = proto_to_npindex(proto);
2140 if (npi < 0) {
2141 /* control or unknown frame - pass it to pppd */
2142 skb_queue_tail(&ppp->file.rq, skb);
2143 /* limit queue length by dropping old frames */
2144 while (ppp->file.rq.qlen > PPP_MAX_RQLEN &&
2145 (skb = skb_dequeue(&ppp->file.rq)))
2146 kfree_skb(skb);
2147 /* wake up any process polling or blocking on read */
2148 wake_up_interruptible(&ppp->file.rwait);
2149
2150 } else {
2151 /* network protocol frame - give it to the kernel */
2152
2153#ifdef CONFIG_PPP_FILTER
2154 /* check if the packet passes the pass and active filters */
2155 /* the filter instructions are constructed assuming
2156 a four-byte PPP header on each packet */
2157 if (ppp->pass_filter || ppp->active_filter) {
2158 if (skb_unclone(skb, GFP_ATOMIC))
2159 goto err;
2160
2161 *(u8 *)skb_push(skb, 2) = 0;
2162 if (ppp->pass_filter &&
2163 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
2164 if (ppp->debug & 1)
2165 netdev_printk(KERN_DEBUG, ppp->dev,
2166 "PPP: inbound frame "
2167 "not passed\n");
2168 kfree_skb(skb);
2169 return;
2170 }
2171 if (!(ppp->active_filter &&
2172 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
2173 ppp->last_recv = jiffies;
2174 __skb_pull(skb, 2);
2175 } else
2176#endif /* CONFIG_PPP_FILTER */
2177 ppp->last_recv = jiffies;
2178
2179 if ((ppp->dev->flags & IFF_UP) == 0 ||
2180 ppp->npmode[npi] != NPMODE_PASS) {
2181 kfree_skb(skb);
2182 } else {
2183 /* chop off protocol */
2184 skb_pull_rcsum(skb, 2);
2185 skb->dev = ppp->dev;
2186 skb->protocol = htons(npindex_to_ethertype[npi]);
2187 skb_reset_mac_header(skb);
2188 skb_scrub_packet(skb, !net_eq(ppp->ppp_net,
2189 dev_net(ppp->dev)));
2190 netif_rx(skb);
2191 }
2192 }
2193 return;
2194
2195 err:
2196 kfree_skb(skb);
2197 ppp_receive_error(ppp);
2198}
2199
2200static struct sk_buff *
2201ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
2202{
2203 int proto = PPP_PROTO(skb);
2204 struct sk_buff *ns;
2205 int len;
2206
2207 /* Until we fix all the decompressor's need to make sure
2208 * data portion is linear.
2209 */
2210 if (!pskb_may_pull(skb, skb->len))
2211 goto err;
2212
2213 if (proto == PPP_COMP) {
2214 int obuff_size;
2215
2216 switch(ppp->rcomp->compress_proto) {
2217 case CI_MPPE:
2218 obuff_size = ppp->mru + PPP_HDRLEN + 1;
2219 break;
2220 default:
2221 obuff_size = ppp->mru + PPP_HDRLEN;
2222 break;
2223 }
2224
2225 ns = dev_alloc_skb(obuff_size);
2226 if (!ns) {
2227 netdev_err(ppp->dev, "ppp_decompress_frame: "
2228 "no memory\n");
2229 goto err;
2230 }
2231 /* the decompressor still expects the A/C bytes in the hdr */
2232 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
2233 skb->len + 2, ns->data, obuff_size);
2234 if (len < 0) {
2235 /* Pass the compressed frame to pppd as an
2236 error indication. */
2237 if (len == DECOMP_FATALERROR)
2238 ppp->rstate |= SC_DC_FERROR;
2239 kfree_skb(ns);
2240 goto err;
2241 }
2242
2243 consume_skb(skb);
2244 skb = ns;
2245 skb_put(skb, len);
2246 skb_pull(skb, 2); /* pull off the A/C bytes */
2247
2248 } else {
2249 /* Uncompressed frame - pass to decompressor so it
2250 can update its dictionary if necessary. */
2251 if (ppp->rcomp->incomp)
2252 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
2253 skb->len + 2);
2254 }
2255
2256 return skb;
2257
2258 err:
2259 ppp->rstate |= SC_DC_ERROR;
2260 ppp_receive_error(ppp);
2261 return skb;
2262}
2263
2264#ifdef CONFIG_PPP_MULTILINK
2265/*
2266 * Receive a multilink frame.
2267 * We put it on the reconstruction queue and then pull off
2268 * as many completed frames as we can.
2269 */
2270static void
2271ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
2272{
2273 u32 mask, seq;
2274 struct channel *ch;
2275 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
2276
2277 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
2278 goto err; /* no good, throw it away */
2279
2280 /* Decode sequence number and begin/end bits */
2281 if (ppp->flags & SC_MP_SHORTSEQ) {
2282 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
2283 mask = 0xfff;
2284 } else {
2285 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
2286 mask = 0xffffff;
2287 }
2288 PPP_MP_CB(skb)->BEbits = skb->data[2];
2289 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
2290
2291 /*
2292 * Do protocol ID decompression on the first fragment of each packet.
2293 */
2294 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1))
2295 *(u8 *)skb_push(skb, 1) = 0;
2296
2297 /*
2298 * Expand sequence number to 32 bits, making it as close
2299 * as possible to ppp->minseq.
2300 */
2301 seq |= ppp->minseq & ~mask;
2302 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
2303 seq += mask + 1;
2304 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
2305 seq -= mask + 1; /* should never happen */
2306 PPP_MP_CB(skb)->sequence = seq;
2307 pch->lastseq = seq;
2308
2309 /*
2310 * If this packet comes before the next one we were expecting,
2311 * drop it.
2312 */
2313 if (seq_before(seq, ppp->nextseq)) {
2314 kfree_skb(skb);
2315 ++ppp->dev->stats.rx_dropped;
2316 ppp_receive_error(ppp);
2317 return;
2318 }
2319
2320 /*
2321 * Reevaluate minseq, the minimum over all channels of the
2322 * last sequence number received on each channel. Because of
2323 * the increasing sequence number rule, we know that any fragment
2324 * before `minseq' which hasn't arrived is never going to arrive.
2325 * The list of channels can't change because we have the receive
2326 * side of the ppp unit locked.
2327 */
2328 list_for_each_entry(ch, &ppp->channels, clist) {
2329 if (seq_before(ch->lastseq, seq))
2330 seq = ch->lastseq;
2331 }
2332 if (seq_before(ppp->minseq, seq))
2333 ppp->minseq = seq;
2334
2335 /* Put the fragment on the reconstruction queue */
2336 ppp_mp_insert(ppp, skb);
2337
2338 /* If the queue is getting long, don't wait any longer for packets
2339 before the start of the queue. */
2340 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
2341 struct sk_buff *mskb = skb_peek(&ppp->mrq);
2342 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence))
2343 ppp->minseq = PPP_MP_CB(mskb)->sequence;
2344 }
2345
2346 /* Pull completed packets off the queue and receive them. */
2347 while ((skb = ppp_mp_reconstruct(ppp))) {
2348 if (pskb_may_pull(skb, 2))
2349 ppp_receive_nonmp_frame(ppp, skb);
2350 else {
2351 ++ppp->dev->stats.rx_length_errors;
2352 kfree_skb(skb);
2353 ppp_receive_error(ppp);
2354 }
2355 }
2356
2357 return;
2358
2359 err:
2360 kfree_skb(skb);
2361 ppp_receive_error(ppp);
2362}
2363
2364/*
2365 * Insert a fragment on the MP reconstruction queue.
2366 * The queue is ordered by increasing sequence number.
2367 */
2368static void
2369ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
2370{
2371 struct sk_buff *p;
2372 struct sk_buff_head *list = &ppp->mrq;
2373 u32 seq = PPP_MP_CB(skb)->sequence;
2374
2375 /* N.B. we don't need to lock the list lock because we have the
2376 ppp unit receive-side lock. */
2377 skb_queue_walk(list, p) {
2378 if (seq_before(seq, PPP_MP_CB(p)->sequence))
2379 break;
2380 }
2381 __skb_queue_before(list, p, skb);
2382}
2383
2384/*
2385 * Reconstruct a packet from the MP fragment queue.
2386 * We go through increasing sequence numbers until we find a
2387 * complete packet, or we get to the sequence number for a fragment
2388 * which hasn't arrived but might still do so.
2389 */
2390static struct sk_buff *
2391ppp_mp_reconstruct(struct ppp *ppp)
2392{
2393 u32 seq = ppp->nextseq;
2394 u32 minseq = ppp->minseq;
2395 struct sk_buff_head *list = &ppp->mrq;
2396 struct sk_buff *p, *tmp;
2397 struct sk_buff *head, *tail;
2398 struct sk_buff *skb = NULL;
2399 int lost = 0, len = 0;
2400
2401 if (ppp->mrru == 0) /* do nothing until mrru is set */
2402 return NULL;
2403 head = list->next;
2404 tail = NULL;
2405 skb_queue_walk_safe(list, p, tmp) {
2406 again:
2407 if (seq_before(PPP_MP_CB(p)->sequence, seq)) {
2408 /* this can't happen, anyway ignore the skb */
2409 netdev_err(ppp->dev, "ppp_mp_reconstruct bad "
2410 "seq %u < %u\n",
2411 PPP_MP_CB(p)->sequence, seq);
2412 __skb_unlink(p, list);
2413 kfree_skb(p);
2414 continue;
2415 }
2416 if (PPP_MP_CB(p)->sequence != seq) {
2417 u32 oldseq;
2418 /* Fragment `seq' is missing. If it is after
2419 minseq, it might arrive later, so stop here. */
2420 if (seq_after(seq, minseq))
2421 break;
2422 /* Fragment `seq' is lost, keep going. */
2423 lost = 1;
2424 oldseq = seq;
2425 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)?
2426 minseq + 1: PPP_MP_CB(p)->sequence;
2427
2428 if (ppp->debug & 1)
2429 netdev_printk(KERN_DEBUG, ppp->dev,
2430 "lost frag %u..%u\n",
2431 oldseq, seq-1);
2432
2433 goto again;
2434 }
2435
2436 /*
2437 * At this point we know that all the fragments from
2438 * ppp->nextseq to seq are either present or lost.
2439 * Also, there are no complete packets in the queue
2440 * that have no missing fragments and end before this
2441 * fragment.
2442 */
2443
2444 /* B bit set indicates this fragment starts a packet */
2445 if (PPP_MP_CB(p)->BEbits & B) {
2446 head = p;
2447 lost = 0;
2448 len = 0;
2449 }
2450
2451 len += p->len;
2452
2453 /* Got a complete packet yet? */
2454 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) &&
2455 (PPP_MP_CB(head)->BEbits & B)) {
2456 if (len > ppp->mrru + 2) {
2457 ++ppp->dev->stats.rx_length_errors;
2458 netdev_printk(KERN_DEBUG, ppp->dev,
2459 "PPP: reconstructed packet"
2460 " is too long (%d)\n", len);
2461 } else {
2462 tail = p;
2463 break;
2464 }
2465 ppp->nextseq = seq + 1;
2466 }
2467
2468 /*
2469 * If this is the ending fragment of a packet,
2470 * and we haven't found a complete valid packet yet,
2471 * we can discard up to and including this fragment.
2472 */
2473 if (PPP_MP_CB(p)->BEbits & E) {
2474 struct sk_buff *tmp2;
2475
2476 skb_queue_reverse_walk_from_safe(list, p, tmp2) {
2477 if (ppp->debug & 1)
2478 netdev_printk(KERN_DEBUG, ppp->dev,
2479 "discarding frag %u\n",
2480 PPP_MP_CB(p)->sequence);
2481 __skb_unlink(p, list);
2482 kfree_skb(p);
2483 }
2484 head = skb_peek(list);
2485 if (!head)
2486 break;
2487 }
2488 ++seq;
2489 }
2490
2491 /* If we have a complete packet, copy it all into one skb. */
2492 if (tail != NULL) {
2493 /* If we have discarded any fragments,
2494 signal a receive error. */
2495 if (PPP_MP_CB(head)->sequence != ppp->nextseq) {
2496 skb_queue_walk_safe(list, p, tmp) {
2497 if (p == head)
2498 break;
2499 if (ppp->debug & 1)
2500 netdev_printk(KERN_DEBUG, ppp->dev,
2501 "discarding frag %u\n",
2502 PPP_MP_CB(p)->sequence);
2503 __skb_unlink(p, list);
2504 kfree_skb(p);
2505 }
2506
2507 if (ppp->debug & 1)
2508 netdev_printk(KERN_DEBUG, ppp->dev,
2509 " missed pkts %u..%u\n",
2510 ppp->nextseq,
2511 PPP_MP_CB(head)->sequence-1);
2512 ++ppp->dev->stats.rx_dropped;
2513 ppp_receive_error(ppp);
2514 }
2515
2516 skb = head;
2517 if (head != tail) {
2518 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list;
2519 p = skb_queue_next(list, head);
2520 __skb_unlink(skb, list);
2521 skb_queue_walk_from_safe(list, p, tmp) {
2522 __skb_unlink(p, list);
2523 *fragpp = p;
2524 p->next = NULL;
2525 fragpp = &p->next;
2526
2527 skb->len += p->len;
2528 skb->data_len += p->len;
2529 skb->truesize += p->truesize;
2530
2531 if (p == tail)
2532 break;
2533 }
2534 } else {
2535 __skb_unlink(skb, list);
2536 }
2537
2538 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1;
2539 }
2540
2541 return skb;
2542}
2543#endif /* CONFIG_PPP_MULTILINK */
2544
2545/*
2546 * Channel interface.
2547 */
2548
2549/* Create a new, unattached ppp channel. */
2550int ppp_register_channel(struct ppp_channel *chan)
2551{
2552 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2553}
2554
2555/* Create a new, unattached ppp channel for specified net. */
2556int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
2557{
2558 struct channel *pch;
2559 struct ppp_net *pn;
2560
2561 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2562 if (!pch)
2563 return -ENOMEM;
2564
2565 pn = ppp_pernet(net);
2566
2567 pch->ppp = NULL;
2568 pch->chan = chan;
2569 pch->chan_net = get_net(net);
2570 chan->ppp = pch;
2571 init_ppp_file(&pch->file, CHANNEL);
2572 pch->file.hdrlen = chan->hdrlen;
2573#ifdef CONFIG_PPP_MULTILINK
2574 pch->lastseq = -1;
2575#endif /* CONFIG_PPP_MULTILINK */
2576 init_rwsem(&pch->chan_sem);
2577 spin_lock_init(&pch->downl);
2578 rwlock_init(&pch->upl);
2579
2580 spin_lock_bh(&pn->all_channels_lock);
2581 pch->file.index = ++pn->last_channel_index;
2582 list_add(&pch->list, &pn->new_channels);
2583 atomic_inc(&channel_count);
2584 spin_unlock_bh(&pn->all_channels_lock);
2585
2586 return 0;
2587}
2588
2589/*
2590 * Return the index of a channel.
2591 */
2592int ppp_channel_index(struct ppp_channel *chan)
2593{
2594 struct channel *pch = chan->ppp;
2595
2596 if (pch)
2597 return pch->file.index;
2598 return -1;
2599}
2600
2601/*
2602 * Return the PPP unit number to which a channel is connected.
2603 */
2604int ppp_unit_number(struct ppp_channel *chan)
2605{
2606 struct channel *pch = chan->ppp;
2607 int unit = -1;
2608
2609 if (pch) {
2610 read_lock_bh(&pch->upl);
2611 if (pch->ppp)
2612 unit = pch->ppp->file.index;
2613 read_unlock_bh(&pch->upl);
2614 }
2615 return unit;
2616}
2617
2618/*
2619 * Return the PPP device interface name of a channel.
2620 */
2621char *ppp_dev_name(struct ppp_channel *chan)
2622{
2623 struct channel *pch = chan->ppp;
2624 char *name = NULL;
2625
2626 if (pch) {
2627 read_lock_bh(&pch->upl);
2628 if (pch->ppp && pch->ppp->dev)
2629 name = pch->ppp->dev->name;
2630 read_unlock_bh(&pch->upl);
2631 }
2632 return name;
2633}
2634
2635
2636/*
2637 * Disconnect a channel from the generic layer.
2638 * This must be called in process context.
2639 */
2640void
2641ppp_unregister_channel(struct ppp_channel *chan)
2642{
2643 struct channel *pch = chan->ppp;
2644 struct ppp_net *pn;
2645
2646 if (!pch)
2647 return; /* should never happen */
2648
2649 chan->ppp = NULL;
2650
2651 /*
2652 * This ensures that we have returned from any calls into the
2653 * the channel's start_xmit or ioctl routine before we proceed.
2654 */
2655 down_write(&pch->chan_sem);
2656 spin_lock_bh(&pch->downl);
2657 pch->chan = NULL;
2658 spin_unlock_bh(&pch->downl);
2659 up_write(&pch->chan_sem);
2660 ppp_disconnect_channel(pch);
2661
2662 pn = ppp_pernet(pch->chan_net);
2663 spin_lock_bh(&pn->all_channels_lock);
2664 list_del(&pch->list);
2665 spin_unlock_bh(&pn->all_channels_lock);
2666
2667 pch->file.dead = 1;
2668 wake_up_interruptible(&pch->file.rwait);
2669 if (refcount_dec_and_test(&pch->file.refcnt))
2670 ppp_destroy_channel(pch);
2671}
2672
2673/*
2674 * Callback from a channel when it can accept more to transmit.
2675 * This should be called at BH/softirq level, not interrupt level.
2676 */
2677void
2678ppp_output_wakeup(struct ppp_channel *chan)
2679{
2680 struct channel *pch = chan->ppp;
2681
2682 if (!pch)
2683 return;
2684 ppp_channel_push(pch);
2685}
2686
2687/*
2688 * Compression control.
2689 */
2690
2691/* Process the PPPIOCSCOMPRESS ioctl. */
2692static int
2693ppp_set_compress(struct ppp *ppp, unsigned long arg)
2694{
2695 int err;
2696 struct compressor *cp, *ocomp;
2697 struct ppp_option_data data;
2698 void *state, *ostate;
2699 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2700
2701 err = -EFAULT;
2702 if (copy_from_user(&data, (void __user *) arg, sizeof(data)))
2703 goto out;
2704 if (data.length > CCP_MAX_OPTION_LENGTH)
2705 goto out;
2706 if (copy_from_user(ccp_option, (void __user *) data.ptr, data.length))
2707 goto out;
2708
2709 err = -EINVAL;
2710 if (data.length < 2 || ccp_option[1] < 2 || ccp_option[1] > data.length)
2711 goto out;
2712
2713 cp = try_then_request_module(
2714 find_compressor(ccp_option[0]),
2715 "ppp-compress-%d", ccp_option[0]);
2716 if (!cp)
2717 goto out;
2718
2719 err = -ENOBUFS;
2720 if (data.transmit) {
2721 state = cp->comp_alloc(ccp_option, data.length);
2722 if (state) {
2723 ppp_xmit_lock(ppp);
2724 ppp->xstate &= ~SC_COMP_RUN;
2725 ocomp = ppp->xcomp;
2726 ostate = ppp->xc_state;
2727 ppp->xcomp = cp;
2728 ppp->xc_state = state;
2729 ppp_xmit_unlock(ppp);
2730 if (ostate) {
2731 ocomp->comp_free(ostate);
2732 module_put(ocomp->owner);
2733 }
2734 err = 0;
2735 } else
2736 module_put(cp->owner);
2737
2738 } else {
2739 state = cp->decomp_alloc(ccp_option, data.length);
2740 if (state) {
2741 ppp_recv_lock(ppp);
2742 ppp->rstate &= ~SC_DECOMP_RUN;
2743 ocomp = ppp->rcomp;
2744 ostate = ppp->rc_state;
2745 ppp->rcomp = cp;
2746 ppp->rc_state = state;
2747 ppp_recv_unlock(ppp);
2748 if (ostate) {
2749 ocomp->decomp_free(ostate);
2750 module_put(ocomp->owner);
2751 }
2752 err = 0;
2753 } else
2754 module_put(cp->owner);
2755 }
2756
2757 out:
2758 return err;
2759}
2760
2761/*
2762 * Look at a CCP packet and update our state accordingly.
2763 * We assume the caller has the xmit or recv path locked.
2764 */
2765static void
2766ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2767{
2768 unsigned char *dp;
2769 int len;
2770
2771 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2772 return; /* no header */
2773 dp = skb->data + 2;
2774
2775 switch (CCP_CODE(dp)) {
2776 case CCP_CONFREQ:
2777
2778 /* A ConfReq starts negotiation of compression
2779 * in one direction of transmission,
2780 * and hence brings it down...but which way?
2781 *
2782 * Remember:
2783 * A ConfReq indicates what the sender would like to receive
2784 */
2785 if(inbound)
2786 /* He is proposing what I should send */
2787 ppp->xstate &= ~SC_COMP_RUN;
2788 else
2789 /* I am proposing to what he should send */
2790 ppp->rstate &= ~SC_DECOMP_RUN;
2791
2792 break;
2793
2794 case CCP_TERMREQ:
2795 case CCP_TERMACK:
2796 /*
2797 * CCP is going down, both directions of transmission
2798 */
2799 ppp->rstate &= ~SC_DECOMP_RUN;
2800 ppp->xstate &= ~SC_COMP_RUN;
2801 break;
2802
2803 case CCP_CONFACK:
2804 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2805 break;
2806 len = CCP_LENGTH(dp);
2807 if (!pskb_may_pull(skb, len + 2))
2808 return; /* too short */
2809 dp += CCP_HDRLEN;
2810 len -= CCP_HDRLEN;
2811 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2812 break;
2813 if (inbound) {
2814 /* we will start receiving compressed packets */
2815 if (!ppp->rc_state)
2816 break;
2817 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2818 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2819 ppp->rstate |= SC_DECOMP_RUN;
2820 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2821 }
2822 } else {
2823 /* we will soon start sending compressed packets */
2824 if (!ppp->xc_state)
2825 break;
2826 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2827 ppp->file.index, 0, ppp->debug))
2828 ppp->xstate |= SC_COMP_RUN;
2829 }
2830 break;
2831
2832 case CCP_RESETACK:
2833 /* reset the [de]compressor */
2834 if ((ppp->flags & SC_CCP_UP) == 0)
2835 break;
2836 if (inbound) {
2837 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2838 ppp->rcomp->decomp_reset(ppp->rc_state);
2839 ppp->rstate &= ~SC_DC_ERROR;
2840 }
2841 } else {
2842 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2843 ppp->xcomp->comp_reset(ppp->xc_state);
2844 }
2845 break;
2846 }
2847}
2848
2849/* Free up compression resources. */
2850static void
2851ppp_ccp_closed(struct ppp *ppp)
2852{
2853 void *xstate, *rstate;
2854 struct compressor *xcomp, *rcomp;
2855
2856 ppp_lock(ppp);
2857 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2858 ppp->xstate = 0;
2859 xcomp = ppp->xcomp;
2860 xstate = ppp->xc_state;
2861 ppp->xc_state = NULL;
2862 ppp->rstate = 0;
2863 rcomp = ppp->rcomp;
2864 rstate = ppp->rc_state;
2865 ppp->rc_state = NULL;
2866 ppp_unlock(ppp);
2867
2868 if (xstate) {
2869 xcomp->comp_free(xstate);
2870 module_put(xcomp->owner);
2871 }
2872 if (rstate) {
2873 rcomp->decomp_free(rstate);
2874 module_put(rcomp->owner);
2875 }
2876}
2877
2878/* List of compressors. */
2879static LIST_HEAD(compressor_list);
2880static DEFINE_SPINLOCK(compressor_list_lock);
2881
2882struct compressor_entry {
2883 struct list_head list;
2884 struct compressor *comp;
2885};
2886
2887static struct compressor_entry *
2888find_comp_entry(int proto)
2889{
2890 struct compressor_entry *ce;
2891
2892 list_for_each_entry(ce, &compressor_list, list) {
2893 if (ce->comp->compress_proto == proto)
2894 return ce;
2895 }
2896 return NULL;
2897}
2898
2899/* Register a compressor */
2900int
2901ppp_register_compressor(struct compressor *cp)
2902{
2903 struct compressor_entry *ce;
2904 int ret;
2905 spin_lock(&compressor_list_lock);
2906 ret = -EEXIST;
2907 if (find_comp_entry(cp->compress_proto))
2908 goto out;
2909 ret = -ENOMEM;
2910 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2911 if (!ce)
2912 goto out;
2913 ret = 0;
2914 ce->comp = cp;
2915 list_add(&ce->list, &compressor_list);
2916 out:
2917 spin_unlock(&compressor_list_lock);
2918 return ret;
2919}
2920
2921/* Unregister a compressor */
2922void
2923ppp_unregister_compressor(struct compressor *cp)
2924{
2925 struct compressor_entry *ce;
2926
2927 spin_lock(&compressor_list_lock);
2928 ce = find_comp_entry(cp->compress_proto);
2929 if (ce && ce->comp == cp) {
2930 list_del(&ce->list);
2931 kfree(ce);
2932 }
2933 spin_unlock(&compressor_list_lock);
2934}
2935
2936/* Find a compressor. */
2937static struct compressor *
2938find_compressor(int type)
2939{
2940 struct compressor_entry *ce;
2941 struct compressor *cp = NULL;
2942
2943 spin_lock(&compressor_list_lock);
2944 ce = find_comp_entry(type);
2945 if (ce) {
2946 cp = ce->comp;
2947 if (!try_module_get(cp->owner))
2948 cp = NULL;
2949 }
2950 spin_unlock(&compressor_list_lock);
2951 return cp;
2952}
2953
2954/*
2955 * Miscelleneous stuff.
2956 */
2957
2958static void
2959ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2960{
2961 struct slcompress *vj = ppp->vj;
2962
2963 memset(st, 0, sizeof(*st));
2964 st->p.ppp_ipackets = ppp->stats64.rx_packets;
2965 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2966 st->p.ppp_ibytes = ppp->stats64.rx_bytes;
2967 st->p.ppp_opackets = ppp->stats64.tx_packets;
2968 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2969 st->p.ppp_obytes = ppp->stats64.tx_bytes;
2970 if (!vj)
2971 return;
2972 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2973 st->vj.vjs_compressed = vj->sls_o_compressed;
2974 st->vj.vjs_searches = vj->sls_o_searches;
2975 st->vj.vjs_misses = vj->sls_o_misses;
2976 st->vj.vjs_errorin = vj->sls_i_error;
2977 st->vj.vjs_tossed = vj->sls_i_tossed;
2978 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2979 st->vj.vjs_compressedin = vj->sls_i_compressed;
2980}
2981
2982/*
2983 * Stuff for handling the lists of ppp units and channels
2984 * and for initialization.
2985 */
2986
2987/*
2988 * Create a new ppp interface unit. Fails if it can't allocate memory
2989 * or if there is already a unit with the requested number.
2990 * unit == -1 means allocate a new number.
2991 */
2992static int ppp_create_interface(struct net *net, struct file *file, int *unit)
2993{
2994 struct ppp_config conf = {
2995 .file = file,
2996 .unit = *unit,
2997 .ifname_is_set = false,
2998 };
2999 struct net_device *dev;
3000 struct ppp *ppp;
3001 int err;
3002
3003 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_ENUM, ppp_setup);
3004 if (!dev) {
3005 err = -ENOMEM;
3006 goto err;
3007 }
3008 dev_net_set(dev, net);
3009 dev->rtnl_link_ops = &ppp_link_ops;
3010
3011 rtnl_lock();
3012
3013 err = ppp_dev_configure(net, dev, &conf);
3014 if (err < 0)
3015 goto err_dev;
3016 ppp = netdev_priv(dev);
3017 *unit = ppp->file.index;
3018
3019 rtnl_unlock();
3020
3021 return 0;
3022
3023err_dev:
3024 rtnl_unlock();
3025 free_netdev(dev);
3026err:
3027 return err;
3028}
3029
3030/*
3031 * Initialize a ppp_file structure.
3032 */
3033static void
3034init_ppp_file(struct ppp_file *pf, int kind)
3035{
3036 pf->kind = kind;
3037 skb_queue_head_init(&pf->xq);
3038 skb_queue_head_init(&pf->rq);
3039 refcount_set(&pf->refcnt, 1);
3040 init_waitqueue_head(&pf->rwait);
3041}
3042
3043/*
3044 * Free the memory used by a ppp unit. This is only called once
3045 * there are no channels connected to the unit and no file structs
3046 * that reference the unit.
3047 */
3048static void ppp_destroy_interface(struct ppp *ppp)
3049{
3050 atomic_dec(&ppp_unit_count);
3051
3052 if (!ppp->file.dead || ppp->n_channels) {
3053 /* "can't happen" */
3054 netdev_err(ppp->dev, "ppp: destroying ppp struct %p "
3055 "but dead=%d n_channels=%d !\n",
3056 ppp, ppp->file.dead, ppp->n_channels);
3057 return;
3058 }
3059
3060 ppp_ccp_closed(ppp);
3061 if (ppp->vj) {
3062 slhc_free(ppp->vj);
3063 ppp->vj = NULL;
3064 }
3065 skb_queue_purge(&ppp->file.xq);
3066 skb_queue_purge(&ppp->file.rq);
3067#ifdef CONFIG_PPP_MULTILINK
3068 skb_queue_purge(&ppp->mrq);
3069#endif /* CONFIG_PPP_MULTILINK */
3070#ifdef CONFIG_PPP_FILTER
3071 if (ppp->pass_filter) {
3072 bpf_prog_destroy(ppp->pass_filter);
3073 ppp->pass_filter = NULL;
3074 }
3075
3076 if (ppp->active_filter) {
3077 bpf_prog_destroy(ppp->active_filter);
3078 ppp->active_filter = NULL;
3079 }
3080#endif /* CONFIG_PPP_FILTER */
3081
3082 kfree_skb(ppp->xmit_pending);
3083 free_percpu(ppp->xmit_recursion);
3084
3085 free_netdev(ppp->dev);
3086}
3087
3088/*
3089 * Locate an existing ppp unit.
3090 * The caller should have locked the all_ppp_mutex.
3091 */
3092static struct ppp *
3093ppp_find_unit(struct ppp_net *pn, int unit)
3094{
3095 return unit_find(&pn->units_idr, unit);
3096}
3097
3098/*
3099 * Locate an existing ppp channel.
3100 * The caller should have locked the all_channels_lock.
3101 * First we look in the new_channels list, then in the
3102 * all_channels list. If found in the new_channels list,
3103 * we move it to the all_channels list. This is for speed
3104 * when we have a lot of channels in use.
3105 */
3106static struct channel *
3107ppp_find_channel(struct ppp_net *pn, int unit)
3108{
3109 struct channel *pch;
3110
3111 list_for_each_entry(pch, &pn->new_channels, list) {
3112 if (pch->file.index == unit) {
3113 list_move(&pch->list, &pn->all_channels);
3114 return pch;
3115 }
3116 }
3117
3118 list_for_each_entry(pch, &pn->all_channels, list) {
3119 if (pch->file.index == unit)
3120 return pch;
3121 }
3122
3123 return NULL;
3124}
3125
3126/*
3127 * Connect a PPP channel to a PPP interface unit.
3128 */
3129static int
3130ppp_connect_channel(struct channel *pch, int unit)
3131{
3132 struct ppp *ppp;
3133 struct ppp_net *pn;
3134 int ret = -ENXIO;
3135 int hdrlen;
3136
3137 pn = ppp_pernet(pch->chan_net);
3138
3139 mutex_lock(&pn->all_ppp_mutex);
3140 ppp = ppp_find_unit(pn, unit);
3141 if (!ppp)
3142 goto out;
3143 write_lock_bh(&pch->upl);
3144 ret = -EINVAL;
3145 if (pch->ppp)
3146 goto outl;
3147
3148 ppp_lock(ppp);
3149 spin_lock_bh(&pch->downl);
3150 if (!pch->chan) {
3151 /* Don't connect unregistered channels */
3152 spin_unlock_bh(&pch->downl);
3153 ppp_unlock(ppp);
3154 ret = -ENOTCONN;
3155 goto outl;
3156 }
3157 spin_unlock_bh(&pch->downl);
3158 if (pch->file.hdrlen > ppp->file.hdrlen)
3159 ppp->file.hdrlen = pch->file.hdrlen;
3160 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
3161 if (hdrlen > ppp->dev->hard_header_len)
3162 ppp->dev->hard_header_len = hdrlen;
3163 list_add_tail(&pch->clist, &ppp->channels);
3164 ++ppp->n_channels;
3165 pch->ppp = ppp;
3166 refcount_inc(&ppp->file.refcnt);
3167 ppp_unlock(ppp);
3168 ret = 0;
3169
3170 outl:
3171 write_unlock_bh(&pch->upl);
3172 out:
3173 mutex_unlock(&pn->all_ppp_mutex);
3174 return ret;
3175}
3176
3177/*
3178 * Disconnect a channel from its ppp unit.
3179 */
3180static int
3181ppp_disconnect_channel(struct channel *pch)
3182{
3183 struct ppp *ppp;
3184 int err = -EINVAL;
3185
3186 write_lock_bh(&pch->upl);
3187 ppp = pch->ppp;
3188 pch->ppp = NULL;
3189 write_unlock_bh(&pch->upl);
3190 if (ppp) {
3191 /* remove it from the ppp unit's list */
3192 ppp_lock(ppp);
3193 list_del(&pch->clist);
3194 if (--ppp->n_channels == 0)
3195 wake_up_interruptible(&ppp->file.rwait);
3196 ppp_unlock(ppp);
3197 if (refcount_dec_and_test(&ppp->file.refcnt))
3198 ppp_destroy_interface(ppp);
3199 err = 0;
3200 }
3201 return err;
3202}
3203
3204/*
3205 * Free up the resources used by a ppp channel.
3206 */
3207static void ppp_destroy_channel(struct channel *pch)
3208{
3209 put_net(pch->chan_net);
3210 pch->chan_net = NULL;
3211
3212 atomic_dec(&channel_count);
3213
3214 if (!pch->file.dead) {
3215 /* "can't happen" */
3216 pr_err("ppp: destroying undead channel %p !\n", pch);
3217 return;
3218 }
3219 skb_queue_purge(&pch->file.xq);
3220 skb_queue_purge(&pch->file.rq);
3221 kfree(pch);
3222}
3223
3224static void __exit ppp_cleanup(void)
3225{
3226 /* should never happen */
3227 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
3228 pr_err("PPP: removing module but units remain!\n");
3229 rtnl_link_unregister(&ppp_link_ops);
3230 unregister_chrdev(PPP_MAJOR, "ppp");
3231 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
3232 class_destroy(ppp_class);
3233 unregister_pernet_device(&ppp_net_ops);
3234}
3235
3236/*
3237 * Units handling. Caller must protect concurrent access
3238 * by holding all_ppp_mutex
3239 */
3240
3241/* associate pointer with specified number */
3242static int unit_set(struct idr *p, void *ptr, int n)
3243{
3244 int unit;
3245
3246 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL);
3247 if (unit == -ENOSPC)
3248 unit = -EINVAL;
3249 return unit;
3250}
3251
3252/* get new free unit number and associate pointer with it */
3253static int unit_get(struct idr *p, void *ptr)
3254{
3255 return idr_alloc(p, ptr, 0, 0, GFP_KERNEL);
3256}
3257
3258/* put unit number back to a pool */
3259static void unit_put(struct idr *p, int n)
3260{
3261 idr_remove(p, n);
3262}
3263
3264/* get pointer associated with the number */
3265static void *unit_find(struct idr *p, int n)
3266{
3267 return idr_find(p, n);
3268}
3269
3270/* Module/initialization stuff */
3271
3272module_init(ppp_init);
3273module_exit(ppp_cleanup);
3274
3275EXPORT_SYMBOL(ppp_register_net_channel);
3276EXPORT_SYMBOL(ppp_register_channel);
3277EXPORT_SYMBOL(ppp_unregister_channel);
3278EXPORT_SYMBOL(ppp_channel_index);
3279EXPORT_SYMBOL(ppp_unit_number);
3280EXPORT_SYMBOL(ppp_dev_name);
3281EXPORT_SYMBOL(ppp_input);
3282EXPORT_SYMBOL(ppp_input_error);
3283EXPORT_SYMBOL(ppp_output_wakeup);
3284EXPORT_SYMBOL(ppp_register_compressor);
3285EXPORT_SYMBOL(ppp_unregister_compressor);
3286MODULE_LICENSE("GPL");
3287MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
3288MODULE_ALIAS_RTNL_LINK("ppp");
3289MODULE_ALIAS("devname:ppp");
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Generic PPP layer for Linux.
4 *
5 * Copyright 1999-2002 Paul Mackerras.
6 *
7 * The generic PPP layer handles the PPP network interfaces, the
8 * /dev/ppp device, packet and VJ compression, and multilink.
9 * It talks to PPP `channels' via the interface defined in
10 * include/linux/ppp_channel.h. Channels provide the basic means for
11 * sending and receiving PPP frames on some kind of communications
12 * channel.
13 *
14 * Part of the code in this driver was inspired by the old async-only
15 * PPP driver, written by Michael Callahan and Al Longyear, and
16 * subsequently hacked by Paul Mackerras.
17 *
18 * ==FILEVERSION 20041108==
19 */
20
21#include <linux/module.h>
22#include <linux/kernel.h>
23#include <linux/sched/signal.h>
24#include <linux/kmod.h>
25#include <linux/init.h>
26#include <linux/list.h>
27#include <linux/idr.h>
28#include <linux/netdevice.h>
29#include <linux/poll.h>
30#include <linux/ppp_defs.h>
31#include <linux/filter.h>
32#include <linux/ppp-ioctl.h>
33#include <linux/ppp_channel.h>
34#include <linux/ppp-comp.h>
35#include <linux/skbuff.h>
36#include <linux/rtnetlink.h>
37#include <linux/if_arp.h>
38#include <linux/ip.h>
39#include <linux/tcp.h>
40#include <linux/spinlock.h>
41#include <linux/rwsem.h>
42#include <linux/stddef.h>
43#include <linux/device.h>
44#include <linux/mutex.h>
45#include <linux/slab.h>
46#include <linux/file.h>
47#include <asm/unaligned.h>
48#include <net/slhc_vj.h>
49#include <linux/atomic.h>
50#include <linux/refcount.h>
51
52#include <linux/nsproxy.h>
53#include <net/net_namespace.h>
54#include <net/netns/generic.h>
55
56#define PPP_VERSION "2.4.2"
57
58/*
59 * Network protocols we support.
60 */
61#define NP_IP 0 /* Internet Protocol V4 */
62#define NP_IPV6 1 /* Internet Protocol V6 */
63#define NP_IPX 2 /* IPX protocol */
64#define NP_AT 3 /* Appletalk protocol */
65#define NP_MPLS_UC 4 /* MPLS unicast */
66#define NP_MPLS_MC 5 /* MPLS multicast */
67#define NUM_NP 6 /* Number of NPs. */
68
69#define MPHDRLEN 6 /* multilink protocol header length */
70#define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */
71
72#define PPP_PROTO_LEN 2
73
74/*
75 * An instance of /dev/ppp can be associated with either a ppp
76 * interface unit or a ppp channel. In both cases, file->private_data
77 * points to one of these.
78 */
79struct ppp_file {
80 enum {
81 INTERFACE=1, CHANNEL
82 } kind;
83 struct sk_buff_head xq; /* pppd transmit queue */
84 struct sk_buff_head rq; /* receive queue for pppd */
85 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */
86 refcount_t refcnt; /* # refs (incl /dev/ppp attached) */
87 int hdrlen; /* space to leave for headers */
88 int index; /* interface unit / channel number */
89 int dead; /* unit/channel has been shut down */
90};
91
92#define PF_TO_X(pf, X) container_of(pf, X, file)
93
94#define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
95#define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
96
97/*
98 * Data structure to hold primary network stats for which
99 * we want to use 64 bit storage. Other network stats
100 * are stored in dev->stats of the ppp strucute.
101 */
102struct ppp_link_stats {
103 u64 rx_packets;
104 u64 tx_packets;
105 u64 rx_bytes;
106 u64 tx_bytes;
107};
108
109/*
110 * Data structure describing one ppp unit.
111 * A ppp unit corresponds to a ppp network interface device
112 * and represents a multilink bundle.
113 * It can have 0 or more ppp channels connected to it.
114 */
115struct ppp {
116 struct ppp_file file; /* stuff for read/write/poll 0 */
117 struct file *owner; /* file that owns this unit 48 */
118 struct list_head channels; /* list of attached channels 4c */
119 int n_channels; /* how many channels are attached 54 */
120 spinlock_t rlock; /* lock for receive side 58 */
121 spinlock_t wlock; /* lock for transmit side 5c */
122 int __percpu *xmit_recursion; /* xmit recursion detect */
123 int mru; /* max receive unit 60 */
124 unsigned int flags; /* control bits 64 */
125 unsigned int xstate; /* transmit state bits 68 */
126 unsigned int rstate; /* receive state bits 6c */
127 int debug; /* debug flags 70 */
128 struct slcompress *vj; /* state for VJ header compression */
129 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
130 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
131 struct compressor *xcomp; /* transmit packet compressor 8c */
132 void *xc_state; /* its internal state 90 */
133 struct compressor *rcomp; /* receive decompressor 94 */
134 void *rc_state; /* its internal state 98 */
135 unsigned long last_xmit; /* jiffies when last pkt sent 9c */
136 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
137 struct net_device *dev; /* network interface device a4 */
138 int closing; /* is device closing down? a8 */
139#ifdef CONFIG_PPP_MULTILINK
140 int nxchan; /* next channel to send something on */
141 u32 nxseq; /* next sequence number to send */
142 int mrru; /* MP: max reconst. receive unit */
143 u32 nextseq; /* MP: seq no of next packet */
144 u32 minseq; /* MP: min of most recent seqnos */
145 struct sk_buff_head mrq; /* MP: receive reconstruction queue */
146#endif /* CONFIG_PPP_MULTILINK */
147#ifdef CONFIG_PPP_FILTER
148 struct bpf_prog *pass_filter; /* filter for packets to pass */
149 struct bpf_prog *active_filter; /* filter for pkts to reset idle */
150#endif /* CONFIG_PPP_FILTER */
151 struct net *ppp_net; /* the net we belong to */
152 struct ppp_link_stats stats64; /* 64 bit network stats */
153};
154
155/*
156 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
157 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
158 * SC_MUST_COMP
159 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
160 * Bits in xstate: SC_COMP_RUN
161 */
162#define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
163 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
164 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
165
166/*
167 * Private data structure for each channel.
168 * This includes the data structure used for multilink.
169 */
170struct channel {
171 struct ppp_file file; /* stuff for read/write/poll */
172 struct list_head list; /* link in all/new_channels list */
173 struct ppp_channel *chan; /* public channel data structure */
174 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
175 spinlock_t downl; /* protects `chan', file.xq dequeue */
176 struct ppp *ppp; /* ppp unit we're connected to */
177 struct net *chan_net; /* the net channel belongs to */
178 netns_tracker ns_tracker;
179 struct list_head clist; /* link in list of channels per unit */
180 rwlock_t upl; /* protects `ppp' and 'bridge' */
181 struct channel __rcu *bridge; /* "bridged" ppp channel */
182#ifdef CONFIG_PPP_MULTILINK
183 u8 avail; /* flag used in multilink stuff */
184 u8 had_frag; /* >= 1 fragments have been sent */
185 u32 lastseq; /* MP: last sequence # received */
186 int speed; /* speed of the corresponding ppp channel*/
187#endif /* CONFIG_PPP_MULTILINK */
188};
189
190struct ppp_config {
191 struct file *file;
192 s32 unit;
193 bool ifname_is_set;
194};
195
196/*
197 * SMP locking issues:
198 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
199 * list and the ppp.n_channels field, you need to take both locks
200 * before you modify them.
201 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
202 * channel.downl.
203 */
204
205static DEFINE_MUTEX(ppp_mutex);
206static atomic_t ppp_unit_count = ATOMIC_INIT(0);
207static atomic_t channel_count = ATOMIC_INIT(0);
208
209/* per-net private data for this module */
210static unsigned int ppp_net_id __read_mostly;
211struct ppp_net {
212 /* units to ppp mapping */
213 struct idr units_idr;
214
215 /*
216 * all_ppp_mutex protects the units_idr mapping.
217 * It also ensures that finding a ppp unit in the units_idr
218 * map and updating its file.refcnt field is atomic.
219 */
220 struct mutex all_ppp_mutex;
221
222 /* channels */
223 struct list_head all_channels;
224 struct list_head new_channels;
225 int last_channel_index;
226
227 /*
228 * all_channels_lock protects all_channels and
229 * last_channel_index, and the atomicity of find
230 * a channel and updating its file.refcnt field.
231 */
232 spinlock_t all_channels_lock;
233};
234
235/* Get the PPP protocol number from a skb */
236#define PPP_PROTO(skb) get_unaligned_be16((skb)->data)
237
238/* We limit the length of ppp->file.rq to this (arbitrary) value */
239#define PPP_MAX_RQLEN 32
240
241/*
242 * Maximum number of multilink fragments queued up.
243 * This has to be large enough to cope with the maximum latency of
244 * the slowest channel relative to the others. Strictly it should
245 * depend on the number of channels and their characteristics.
246 */
247#define PPP_MP_MAX_QLEN 128
248
249/* Multilink header bits. */
250#define B 0x80 /* this fragment begins a packet */
251#define E 0x40 /* this fragment ends a packet */
252
253/* Compare multilink sequence numbers (assumed to be 32 bits wide) */
254#define seq_before(a, b) ((s32)((a) - (b)) < 0)
255#define seq_after(a, b) ((s32)((a) - (b)) > 0)
256
257/* Prototypes. */
258static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
259 struct file *file, unsigned int cmd, unsigned long arg);
260static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb);
261static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
262static void ppp_push(struct ppp *ppp);
263static void ppp_channel_push(struct channel *pch);
264static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
265 struct channel *pch);
266static void ppp_receive_error(struct ppp *ppp);
267static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
268static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
269 struct sk_buff *skb);
270#ifdef CONFIG_PPP_MULTILINK
271static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
272 struct channel *pch);
273static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
274static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
275static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
276#endif /* CONFIG_PPP_MULTILINK */
277static int ppp_set_compress(struct ppp *ppp, struct ppp_option_data *data);
278static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
279static void ppp_ccp_closed(struct ppp *ppp);
280static struct compressor *find_compressor(int type);
281static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
282static int ppp_create_interface(struct net *net, struct file *file, int *unit);
283static void init_ppp_file(struct ppp_file *pf, int kind);
284static void ppp_destroy_interface(struct ppp *ppp);
285static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit);
286static struct channel *ppp_find_channel(struct ppp_net *pn, int unit);
287static int ppp_connect_channel(struct channel *pch, int unit);
288static int ppp_disconnect_channel(struct channel *pch);
289static void ppp_destroy_channel(struct channel *pch);
290static int unit_get(struct idr *p, void *ptr, int min);
291static int unit_set(struct idr *p, void *ptr, int n);
292static void unit_put(struct idr *p, int n);
293static void *unit_find(struct idr *p, int n);
294static void ppp_setup(struct net_device *dev);
295
296static const struct net_device_ops ppp_netdev_ops;
297
298static struct class *ppp_class;
299
300/* per net-namespace data */
301static inline struct ppp_net *ppp_pernet(struct net *net)
302{
303 return net_generic(net, ppp_net_id);
304}
305
306/* Translates a PPP protocol number to a NP index (NP == network protocol) */
307static inline int proto_to_npindex(int proto)
308{
309 switch (proto) {
310 case PPP_IP:
311 return NP_IP;
312 case PPP_IPV6:
313 return NP_IPV6;
314 case PPP_IPX:
315 return NP_IPX;
316 case PPP_AT:
317 return NP_AT;
318 case PPP_MPLS_UC:
319 return NP_MPLS_UC;
320 case PPP_MPLS_MC:
321 return NP_MPLS_MC;
322 }
323 return -EINVAL;
324}
325
326/* Translates an NP index into a PPP protocol number */
327static const int npindex_to_proto[NUM_NP] = {
328 PPP_IP,
329 PPP_IPV6,
330 PPP_IPX,
331 PPP_AT,
332 PPP_MPLS_UC,
333 PPP_MPLS_MC,
334};
335
336/* Translates an ethertype into an NP index */
337static inline int ethertype_to_npindex(int ethertype)
338{
339 switch (ethertype) {
340 case ETH_P_IP:
341 return NP_IP;
342 case ETH_P_IPV6:
343 return NP_IPV6;
344 case ETH_P_IPX:
345 return NP_IPX;
346 case ETH_P_PPPTALK:
347 case ETH_P_ATALK:
348 return NP_AT;
349 case ETH_P_MPLS_UC:
350 return NP_MPLS_UC;
351 case ETH_P_MPLS_MC:
352 return NP_MPLS_MC;
353 }
354 return -1;
355}
356
357/* Translates an NP index into an ethertype */
358static const int npindex_to_ethertype[NUM_NP] = {
359 ETH_P_IP,
360 ETH_P_IPV6,
361 ETH_P_IPX,
362 ETH_P_PPPTALK,
363 ETH_P_MPLS_UC,
364 ETH_P_MPLS_MC,
365};
366
367/*
368 * Locking shorthand.
369 */
370#define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
371#define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
372#define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
373#define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
374#define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
375 ppp_recv_lock(ppp); } while (0)
376#define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
377 ppp_xmit_unlock(ppp); } while (0)
378
379/*
380 * /dev/ppp device routines.
381 * The /dev/ppp device is used by pppd to control the ppp unit.
382 * It supports the read, write, ioctl and poll functions.
383 * Open instances of /dev/ppp can be in one of three states:
384 * unattached, attached to a ppp unit, or attached to a ppp channel.
385 */
386static int ppp_open(struct inode *inode, struct file *file)
387{
388 /*
389 * This could (should?) be enforced by the permissions on /dev/ppp.
390 */
391 if (!ns_capable(file->f_cred->user_ns, CAP_NET_ADMIN))
392 return -EPERM;
393 return 0;
394}
395
396static int ppp_release(struct inode *unused, struct file *file)
397{
398 struct ppp_file *pf = file->private_data;
399 struct ppp *ppp;
400
401 if (pf) {
402 file->private_data = NULL;
403 if (pf->kind == INTERFACE) {
404 ppp = PF_TO_PPP(pf);
405 rtnl_lock();
406 if (file == ppp->owner)
407 unregister_netdevice(ppp->dev);
408 rtnl_unlock();
409 }
410 if (refcount_dec_and_test(&pf->refcnt)) {
411 switch (pf->kind) {
412 case INTERFACE:
413 ppp_destroy_interface(PF_TO_PPP(pf));
414 break;
415 case CHANNEL:
416 ppp_destroy_channel(PF_TO_CHANNEL(pf));
417 break;
418 }
419 }
420 }
421 return 0;
422}
423
424static ssize_t ppp_read(struct file *file, char __user *buf,
425 size_t count, loff_t *ppos)
426{
427 struct ppp_file *pf = file->private_data;
428 DECLARE_WAITQUEUE(wait, current);
429 ssize_t ret;
430 struct sk_buff *skb = NULL;
431 struct iovec iov;
432 struct iov_iter to;
433
434 ret = count;
435
436 if (!pf)
437 return -ENXIO;
438 add_wait_queue(&pf->rwait, &wait);
439 for (;;) {
440 set_current_state(TASK_INTERRUPTIBLE);
441 skb = skb_dequeue(&pf->rq);
442 if (skb)
443 break;
444 ret = 0;
445 if (pf->dead)
446 break;
447 if (pf->kind == INTERFACE) {
448 /*
449 * Return 0 (EOF) on an interface that has no
450 * channels connected, unless it is looping
451 * network traffic (demand mode).
452 */
453 struct ppp *ppp = PF_TO_PPP(pf);
454
455 ppp_recv_lock(ppp);
456 if (ppp->n_channels == 0 &&
457 (ppp->flags & SC_LOOP_TRAFFIC) == 0) {
458 ppp_recv_unlock(ppp);
459 break;
460 }
461 ppp_recv_unlock(ppp);
462 }
463 ret = -EAGAIN;
464 if (file->f_flags & O_NONBLOCK)
465 break;
466 ret = -ERESTARTSYS;
467 if (signal_pending(current))
468 break;
469 schedule();
470 }
471 set_current_state(TASK_RUNNING);
472 remove_wait_queue(&pf->rwait, &wait);
473
474 if (!skb)
475 goto out;
476
477 ret = -EOVERFLOW;
478 if (skb->len > count)
479 goto outf;
480 ret = -EFAULT;
481 iov.iov_base = buf;
482 iov.iov_len = count;
483 iov_iter_init(&to, ITER_DEST, &iov, 1, count);
484 if (skb_copy_datagram_iter(skb, 0, &to, skb->len))
485 goto outf;
486 ret = skb->len;
487
488 outf:
489 kfree_skb(skb);
490 out:
491 return ret;
492}
493
494static ssize_t ppp_write(struct file *file, const char __user *buf,
495 size_t count, loff_t *ppos)
496{
497 struct ppp_file *pf = file->private_data;
498 struct sk_buff *skb;
499 ssize_t ret;
500
501 if (!pf)
502 return -ENXIO;
503 /* All PPP packets should start with the 2-byte protocol */
504 if (count < PPP_PROTO_LEN)
505 return -EINVAL;
506 ret = -ENOMEM;
507 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
508 if (!skb)
509 goto out;
510 skb_reserve(skb, pf->hdrlen);
511 ret = -EFAULT;
512 if (copy_from_user(skb_put(skb, count), buf, count)) {
513 kfree_skb(skb);
514 goto out;
515 }
516
517 switch (pf->kind) {
518 case INTERFACE:
519 ppp_xmit_process(PF_TO_PPP(pf), skb);
520 break;
521 case CHANNEL:
522 skb_queue_tail(&pf->xq, skb);
523 ppp_channel_push(PF_TO_CHANNEL(pf));
524 break;
525 }
526
527 ret = count;
528
529 out:
530 return ret;
531}
532
533/* No kernel lock - fine */
534static __poll_t ppp_poll(struct file *file, poll_table *wait)
535{
536 struct ppp_file *pf = file->private_data;
537 __poll_t mask;
538
539 if (!pf)
540 return 0;
541 poll_wait(file, &pf->rwait, wait);
542 mask = EPOLLOUT | EPOLLWRNORM;
543 if (skb_peek(&pf->rq))
544 mask |= EPOLLIN | EPOLLRDNORM;
545 if (pf->dead)
546 mask |= EPOLLHUP;
547 else if (pf->kind == INTERFACE) {
548 /* see comment in ppp_read */
549 struct ppp *ppp = PF_TO_PPP(pf);
550
551 ppp_recv_lock(ppp);
552 if (ppp->n_channels == 0 &&
553 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
554 mask |= EPOLLIN | EPOLLRDNORM;
555 ppp_recv_unlock(ppp);
556 }
557
558 return mask;
559}
560
561#ifdef CONFIG_PPP_FILTER
562static struct bpf_prog *get_filter(struct sock_fprog *uprog)
563{
564 struct sock_fprog_kern fprog;
565 struct bpf_prog *res = NULL;
566 int err;
567
568 if (!uprog->len)
569 return NULL;
570
571 /* uprog->len is unsigned short, so no overflow here */
572 fprog.len = uprog->len;
573 fprog.filter = memdup_array_user(uprog->filter,
574 uprog->len, sizeof(struct sock_filter));
575 if (IS_ERR(fprog.filter))
576 return ERR_CAST(fprog.filter);
577
578 err = bpf_prog_create(&res, &fprog);
579 kfree(fprog.filter);
580
581 return err ? ERR_PTR(err) : res;
582}
583
584static struct bpf_prog *ppp_get_filter(struct sock_fprog __user *p)
585{
586 struct sock_fprog uprog;
587
588 if (copy_from_user(&uprog, p, sizeof(struct sock_fprog)))
589 return ERR_PTR(-EFAULT);
590 return get_filter(&uprog);
591}
592
593#ifdef CONFIG_COMPAT
594struct sock_fprog32 {
595 unsigned short len;
596 compat_caddr_t filter;
597};
598
599#define PPPIOCSPASS32 _IOW('t', 71, struct sock_fprog32)
600#define PPPIOCSACTIVE32 _IOW('t', 70, struct sock_fprog32)
601
602static struct bpf_prog *compat_ppp_get_filter(struct sock_fprog32 __user *p)
603{
604 struct sock_fprog32 uprog32;
605 struct sock_fprog uprog;
606
607 if (copy_from_user(&uprog32, p, sizeof(struct sock_fprog32)))
608 return ERR_PTR(-EFAULT);
609 uprog.len = uprog32.len;
610 uprog.filter = compat_ptr(uprog32.filter);
611 return get_filter(&uprog);
612}
613#endif
614#endif
615
616/* Bridge one PPP channel to another.
617 * When two channels are bridged, ppp_input on one channel is redirected to
618 * the other's ops->start_xmit handler.
619 * In order to safely bridge channels we must reject channels which are already
620 * part of a bridge instance, or which form part of an existing unit.
621 * Once successfully bridged, each channel holds a reference on the other
622 * to prevent it being freed while the bridge is extant.
623 */
624static int ppp_bridge_channels(struct channel *pch, struct channel *pchb)
625{
626 write_lock_bh(&pch->upl);
627 if (pch->ppp ||
628 rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl))) {
629 write_unlock_bh(&pch->upl);
630 return -EALREADY;
631 }
632 refcount_inc(&pchb->file.refcnt);
633 rcu_assign_pointer(pch->bridge, pchb);
634 write_unlock_bh(&pch->upl);
635
636 write_lock_bh(&pchb->upl);
637 if (pchb->ppp ||
638 rcu_dereference_protected(pchb->bridge, lockdep_is_held(&pchb->upl))) {
639 write_unlock_bh(&pchb->upl);
640 goto err_unset;
641 }
642 refcount_inc(&pch->file.refcnt);
643 rcu_assign_pointer(pchb->bridge, pch);
644 write_unlock_bh(&pchb->upl);
645
646 return 0;
647
648err_unset:
649 write_lock_bh(&pch->upl);
650 /* Re-read pch->bridge with upl held in case it was modified concurrently */
651 pchb = rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl));
652 RCU_INIT_POINTER(pch->bridge, NULL);
653 write_unlock_bh(&pch->upl);
654 synchronize_rcu();
655
656 if (pchb)
657 if (refcount_dec_and_test(&pchb->file.refcnt))
658 ppp_destroy_channel(pchb);
659
660 return -EALREADY;
661}
662
663static int ppp_unbridge_channels(struct channel *pch)
664{
665 struct channel *pchb, *pchbb;
666
667 write_lock_bh(&pch->upl);
668 pchb = rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl));
669 if (!pchb) {
670 write_unlock_bh(&pch->upl);
671 return -EINVAL;
672 }
673 RCU_INIT_POINTER(pch->bridge, NULL);
674 write_unlock_bh(&pch->upl);
675
676 /* Only modify pchb if phcb->bridge points back to pch.
677 * If not, it implies that there has been a race unbridging (and possibly
678 * even rebridging) pchb. We should leave pchb alone to avoid either a
679 * refcount underflow, or breaking another established bridge instance.
680 */
681 write_lock_bh(&pchb->upl);
682 pchbb = rcu_dereference_protected(pchb->bridge, lockdep_is_held(&pchb->upl));
683 if (pchbb == pch)
684 RCU_INIT_POINTER(pchb->bridge, NULL);
685 write_unlock_bh(&pchb->upl);
686
687 synchronize_rcu();
688
689 if (pchbb == pch)
690 if (refcount_dec_and_test(&pch->file.refcnt))
691 ppp_destroy_channel(pch);
692
693 if (refcount_dec_and_test(&pchb->file.refcnt))
694 ppp_destroy_channel(pchb);
695
696 return 0;
697}
698
699static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
700{
701 struct ppp_file *pf;
702 struct ppp *ppp;
703 int err = -EFAULT, val, val2, i;
704 struct ppp_idle32 idle32;
705 struct ppp_idle64 idle64;
706 struct npioctl npi;
707 int unit, cflags;
708 struct slcompress *vj;
709 void __user *argp = (void __user *)arg;
710 int __user *p = argp;
711
712 mutex_lock(&ppp_mutex);
713
714 pf = file->private_data;
715 if (!pf) {
716 err = ppp_unattached_ioctl(current->nsproxy->net_ns,
717 pf, file, cmd, arg);
718 goto out;
719 }
720
721 if (cmd == PPPIOCDETACH) {
722 /*
723 * PPPIOCDETACH is no longer supported as it was heavily broken,
724 * and is only known to have been used by pppd older than
725 * ppp-2.4.2 (released November 2003).
726 */
727 pr_warn_once("%s (%d) used obsolete PPPIOCDETACH ioctl\n",
728 current->comm, current->pid);
729 err = -EINVAL;
730 goto out;
731 }
732
733 if (pf->kind == CHANNEL) {
734 struct channel *pch, *pchb;
735 struct ppp_channel *chan;
736 struct ppp_net *pn;
737
738 pch = PF_TO_CHANNEL(pf);
739
740 switch (cmd) {
741 case PPPIOCCONNECT:
742 if (get_user(unit, p))
743 break;
744 err = ppp_connect_channel(pch, unit);
745 break;
746
747 case PPPIOCDISCONN:
748 err = ppp_disconnect_channel(pch);
749 break;
750
751 case PPPIOCBRIDGECHAN:
752 if (get_user(unit, p))
753 break;
754 err = -ENXIO;
755 pn = ppp_pernet(current->nsproxy->net_ns);
756 spin_lock_bh(&pn->all_channels_lock);
757 pchb = ppp_find_channel(pn, unit);
758 /* Hold a reference to prevent pchb being freed while
759 * we establish the bridge.
760 */
761 if (pchb)
762 refcount_inc(&pchb->file.refcnt);
763 spin_unlock_bh(&pn->all_channels_lock);
764 if (!pchb)
765 break;
766 err = ppp_bridge_channels(pch, pchb);
767 /* Drop earlier refcount now bridge establishment is complete */
768 if (refcount_dec_and_test(&pchb->file.refcnt))
769 ppp_destroy_channel(pchb);
770 break;
771
772 case PPPIOCUNBRIDGECHAN:
773 err = ppp_unbridge_channels(pch);
774 break;
775
776 default:
777 down_read(&pch->chan_sem);
778 chan = pch->chan;
779 err = -ENOTTY;
780 if (chan && chan->ops->ioctl)
781 err = chan->ops->ioctl(chan, cmd, arg);
782 up_read(&pch->chan_sem);
783 }
784 goto out;
785 }
786
787 if (pf->kind != INTERFACE) {
788 /* can't happen */
789 pr_err("PPP: not interface or channel??\n");
790 err = -EINVAL;
791 goto out;
792 }
793
794 ppp = PF_TO_PPP(pf);
795 switch (cmd) {
796 case PPPIOCSMRU:
797 if (get_user(val, p))
798 break;
799 ppp->mru = val;
800 err = 0;
801 break;
802
803 case PPPIOCSFLAGS:
804 if (get_user(val, p))
805 break;
806 ppp_lock(ppp);
807 cflags = ppp->flags & ~val;
808#ifdef CONFIG_PPP_MULTILINK
809 if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK))
810 ppp->nextseq = 0;
811#endif
812 ppp->flags = val & SC_FLAG_BITS;
813 ppp_unlock(ppp);
814 if (cflags & SC_CCP_OPEN)
815 ppp_ccp_closed(ppp);
816 err = 0;
817 break;
818
819 case PPPIOCGFLAGS:
820 val = ppp->flags | ppp->xstate | ppp->rstate;
821 if (put_user(val, p))
822 break;
823 err = 0;
824 break;
825
826 case PPPIOCSCOMPRESS:
827 {
828 struct ppp_option_data data;
829 if (copy_from_user(&data, argp, sizeof(data)))
830 err = -EFAULT;
831 else
832 err = ppp_set_compress(ppp, &data);
833 break;
834 }
835 case PPPIOCGUNIT:
836 if (put_user(ppp->file.index, p))
837 break;
838 err = 0;
839 break;
840
841 case PPPIOCSDEBUG:
842 if (get_user(val, p))
843 break;
844 ppp->debug = val;
845 err = 0;
846 break;
847
848 case PPPIOCGDEBUG:
849 if (put_user(ppp->debug, p))
850 break;
851 err = 0;
852 break;
853
854 case PPPIOCGIDLE32:
855 idle32.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
856 idle32.recv_idle = (jiffies - ppp->last_recv) / HZ;
857 if (copy_to_user(argp, &idle32, sizeof(idle32)))
858 break;
859 err = 0;
860 break;
861
862 case PPPIOCGIDLE64:
863 idle64.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
864 idle64.recv_idle = (jiffies - ppp->last_recv) / HZ;
865 if (copy_to_user(argp, &idle64, sizeof(idle64)))
866 break;
867 err = 0;
868 break;
869
870 case PPPIOCSMAXCID:
871 if (get_user(val, p))
872 break;
873 val2 = 15;
874 if ((val >> 16) != 0) {
875 val2 = val >> 16;
876 val &= 0xffff;
877 }
878 vj = slhc_init(val2+1, val+1);
879 if (IS_ERR(vj)) {
880 err = PTR_ERR(vj);
881 break;
882 }
883 ppp_lock(ppp);
884 if (ppp->vj)
885 slhc_free(ppp->vj);
886 ppp->vj = vj;
887 ppp_unlock(ppp);
888 err = 0;
889 break;
890
891 case PPPIOCGNPMODE:
892 case PPPIOCSNPMODE:
893 if (copy_from_user(&npi, argp, sizeof(npi)))
894 break;
895 err = proto_to_npindex(npi.protocol);
896 if (err < 0)
897 break;
898 i = err;
899 if (cmd == PPPIOCGNPMODE) {
900 err = -EFAULT;
901 npi.mode = ppp->npmode[i];
902 if (copy_to_user(argp, &npi, sizeof(npi)))
903 break;
904 } else {
905 ppp->npmode[i] = npi.mode;
906 /* we may be able to transmit more packets now (??) */
907 netif_wake_queue(ppp->dev);
908 }
909 err = 0;
910 break;
911
912#ifdef CONFIG_PPP_FILTER
913 case PPPIOCSPASS:
914 case PPPIOCSACTIVE:
915 {
916 struct bpf_prog *filter = ppp_get_filter(argp);
917 struct bpf_prog **which;
918
919 if (IS_ERR(filter)) {
920 err = PTR_ERR(filter);
921 break;
922 }
923 if (cmd == PPPIOCSPASS)
924 which = &ppp->pass_filter;
925 else
926 which = &ppp->active_filter;
927 ppp_lock(ppp);
928 if (*which)
929 bpf_prog_destroy(*which);
930 *which = filter;
931 ppp_unlock(ppp);
932 err = 0;
933 break;
934 }
935#endif /* CONFIG_PPP_FILTER */
936
937#ifdef CONFIG_PPP_MULTILINK
938 case PPPIOCSMRRU:
939 if (get_user(val, p))
940 break;
941 ppp_recv_lock(ppp);
942 ppp->mrru = val;
943 ppp_recv_unlock(ppp);
944 err = 0;
945 break;
946#endif /* CONFIG_PPP_MULTILINK */
947
948 default:
949 err = -ENOTTY;
950 }
951
952out:
953 mutex_unlock(&ppp_mutex);
954
955 return err;
956}
957
958#ifdef CONFIG_COMPAT
959struct ppp_option_data32 {
960 compat_uptr_t ptr;
961 u32 length;
962 compat_int_t transmit;
963};
964#define PPPIOCSCOMPRESS32 _IOW('t', 77, struct ppp_option_data32)
965
966static long ppp_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
967{
968 struct ppp_file *pf;
969 int err = -ENOIOCTLCMD;
970 void __user *argp = (void __user *)arg;
971
972 mutex_lock(&ppp_mutex);
973
974 pf = file->private_data;
975 if (pf && pf->kind == INTERFACE) {
976 struct ppp *ppp = PF_TO_PPP(pf);
977 switch (cmd) {
978#ifdef CONFIG_PPP_FILTER
979 case PPPIOCSPASS32:
980 case PPPIOCSACTIVE32:
981 {
982 struct bpf_prog *filter = compat_ppp_get_filter(argp);
983 struct bpf_prog **which;
984
985 if (IS_ERR(filter)) {
986 err = PTR_ERR(filter);
987 break;
988 }
989 if (cmd == PPPIOCSPASS32)
990 which = &ppp->pass_filter;
991 else
992 which = &ppp->active_filter;
993 ppp_lock(ppp);
994 if (*which)
995 bpf_prog_destroy(*which);
996 *which = filter;
997 ppp_unlock(ppp);
998 err = 0;
999 break;
1000 }
1001#endif /* CONFIG_PPP_FILTER */
1002 case PPPIOCSCOMPRESS32:
1003 {
1004 struct ppp_option_data32 data32;
1005 if (copy_from_user(&data32, argp, sizeof(data32))) {
1006 err = -EFAULT;
1007 } else {
1008 struct ppp_option_data data = {
1009 .ptr = compat_ptr(data32.ptr),
1010 .length = data32.length,
1011 .transmit = data32.transmit
1012 };
1013 err = ppp_set_compress(ppp, &data);
1014 }
1015 break;
1016 }
1017 }
1018 }
1019 mutex_unlock(&ppp_mutex);
1020
1021 /* all other commands have compatible arguments */
1022 if (err == -ENOIOCTLCMD)
1023 err = ppp_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
1024
1025 return err;
1026}
1027#endif
1028
1029static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
1030 struct file *file, unsigned int cmd, unsigned long arg)
1031{
1032 int unit, err = -EFAULT;
1033 struct ppp *ppp;
1034 struct channel *chan;
1035 struct ppp_net *pn;
1036 int __user *p = (int __user *)arg;
1037
1038 switch (cmd) {
1039 case PPPIOCNEWUNIT:
1040 /* Create a new ppp unit */
1041 if (get_user(unit, p))
1042 break;
1043 err = ppp_create_interface(net, file, &unit);
1044 if (err < 0)
1045 break;
1046
1047 err = -EFAULT;
1048 if (put_user(unit, p))
1049 break;
1050 err = 0;
1051 break;
1052
1053 case PPPIOCATTACH:
1054 /* Attach to an existing ppp unit */
1055 if (get_user(unit, p))
1056 break;
1057 err = -ENXIO;
1058 pn = ppp_pernet(net);
1059 mutex_lock(&pn->all_ppp_mutex);
1060 ppp = ppp_find_unit(pn, unit);
1061 if (ppp) {
1062 refcount_inc(&ppp->file.refcnt);
1063 file->private_data = &ppp->file;
1064 err = 0;
1065 }
1066 mutex_unlock(&pn->all_ppp_mutex);
1067 break;
1068
1069 case PPPIOCATTCHAN:
1070 if (get_user(unit, p))
1071 break;
1072 err = -ENXIO;
1073 pn = ppp_pernet(net);
1074 spin_lock_bh(&pn->all_channels_lock);
1075 chan = ppp_find_channel(pn, unit);
1076 if (chan) {
1077 refcount_inc(&chan->file.refcnt);
1078 file->private_data = &chan->file;
1079 err = 0;
1080 }
1081 spin_unlock_bh(&pn->all_channels_lock);
1082 break;
1083
1084 default:
1085 err = -ENOTTY;
1086 }
1087
1088 return err;
1089}
1090
1091static const struct file_operations ppp_device_fops = {
1092 .owner = THIS_MODULE,
1093 .read = ppp_read,
1094 .write = ppp_write,
1095 .poll = ppp_poll,
1096 .unlocked_ioctl = ppp_ioctl,
1097#ifdef CONFIG_COMPAT
1098 .compat_ioctl = ppp_compat_ioctl,
1099#endif
1100 .open = ppp_open,
1101 .release = ppp_release,
1102 .llseek = noop_llseek,
1103};
1104
1105static __net_init int ppp_init_net(struct net *net)
1106{
1107 struct ppp_net *pn = net_generic(net, ppp_net_id);
1108
1109 idr_init(&pn->units_idr);
1110 mutex_init(&pn->all_ppp_mutex);
1111
1112 INIT_LIST_HEAD(&pn->all_channels);
1113 INIT_LIST_HEAD(&pn->new_channels);
1114
1115 spin_lock_init(&pn->all_channels_lock);
1116
1117 return 0;
1118}
1119
1120static __net_exit void ppp_exit_net(struct net *net)
1121{
1122 struct ppp_net *pn = net_generic(net, ppp_net_id);
1123 struct net_device *dev;
1124 struct net_device *aux;
1125 struct ppp *ppp;
1126 LIST_HEAD(list);
1127 int id;
1128
1129 rtnl_lock();
1130 for_each_netdev_safe(net, dev, aux) {
1131 if (dev->netdev_ops == &ppp_netdev_ops)
1132 unregister_netdevice_queue(dev, &list);
1133 }
1134
1135 idr_for_each_entry(&pn->units_idr, ppp, id)
1136 /* Skip devices already unregistered by previous loop */
1137 if (!net_eq(dev_net(ppp->dev), net))
1138 unregister_netdevice_queue(ppp->dev, &list);
1139
1140 unregister_netdevice_many(&list);
1141 rtnl_unlock();
1142
1143 mutex_destroy(&pn->all_ppp_mutex);
1144 idr_destroy(&pn->units_idr);
1145 WARN_ON_ONCE(!list_empty(&pn->all_channels));
1146 WARN_ON_ONCE(!list_empty(&pn->new_channels));
1147}
1148
1149static struct pernet_operations ppp_net_ops = {
1150 .init = ppp_init_net,
1151 .exit = ppp_exit_net,
1152 .id = &ppp_net_id,
1153 .size = sizeof(struct ppp_net),
1154};
1155
1156static int ppp_unit_register(struct ppp *ppp, int unit, bool ifname_is_set)
1157{
1158 struct ppp_net *pn = ppp_pernet(ppp->ppp_net);
1159 int ret;
1160
1161 mutex_lock(&pn->all_ppp_mutex);
1162
1163 if (unit < 0) {
1164 ret = unit_get(&pn->units_idr, ppp, 0);
1165 if (ret < 0)
1166 goto err;
1167 if (!ifname_is_set) {
1168 while (1) {
1169 snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ret);
1170 if (!netdev_name_in_use(ppp->ppp_net, ppp->dev->name))
1171 break;
1172 unit_put(&pn->units_idr, ret);
1173 ret = unit_get(&pn->units_idr, ppp, ret + 1);
1174 if (ret < 0)
1175 goto err;
1176 }
1177 }
1178 } else {
1179 /* Caller asked for a specific unit number. Fail with -EEXIST
1180 * if unavailable. For backward compatibility, return -EEXIST
1181 * too if idr allocation fails; this makes pppd retry without
1182 * requesting a specific unit number.
1183 */
1184 if (unit_find(&pn->units_idr, unit)) {
1185 ret = -EEXIST;
1186 goto err;
1187 }
1188 ret = unit_set(&pn->units_idr, ppp, unit);
1189 if (ret < 0) {
1190 /* Rewrite error for backward compatibility */
1191 ret = -EEXIST;
1192 goto err;
1193 }
1194 }
1195 ppp->file.index = ret;
1196
1197 if (!ifname_is_set)
1198 snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ppp->file.index);
1199
1200 mutex_unlock(&pn->all_ppp_mutex);
1201
1202 ret = register_netdevice(ppp->dev);
1203 if (ret < 0)
1204 goto err_unit;
1205
1206 atomic_inc(&ppp_unit_count);
1207
1208 return 0;
1209
1210err_unit:
1211 mutex_lock(&pn->all_ppp_mutex);
1212 unit_put(&pn->units_idr, ppp->file.index);
1213err:
1214 mutex_unlock(&pn->all_ppp_mutex);
1215
1216 return ret;
1217}
1218
1219static int ppp_dev_configure(struct net *src_net, struct net_device *dev,
1220 const struct ppp_config *conf)
1221{
1222 struct ppp *ppp = netdev_priv(dev);
1223 int indx;
1224 int err;
1225 int cpu;
1226
1227 ppp->dev = dev;
1228 ppp->ppp_net = src_net;
1229 ppp->mru = PPP_MRU;
1230 ppp->owner = conf->file;
1231
1232 init_ppp_file(&ppp->file, INTERFACE);
1233 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
1234
1235 for (indx = 0; indx < NUM_NP; ++indx)
1236 ppp->npmode[indx] = NPMODE_PASS;
1237 INIT_LIST_HEAD(&ppp->channels);
1238 spin_lock_init(&ppp->rlock);
1239 spin_lock_init(&ppp->wlock);
1240
1241 ppp->xmit_recursion = alloc_percpu(int);
1242 if (!ppp->xmit_recursion) {
1243 err = -ENOMEM;
1244 goto err1;
1245 }
1246 for_each_possible_cpu(cpu)
1247 (*per_cpu_ptr(ppp->xmit_recursion, cpu)) = 0;
1248
1249#ifdef CONFIG_PPP_MULTILINK
1250 ppp->minseq = -1;
1251 skb_queue_head_init(&ppp->mrq);
1252#endif /* CONFIG_PPP_MULTILINK */
1253#ifdef CONFIG_PPP_FILTER
1254 ppp->pass_filter = NULL;
1255 ppp->active_filter = NULL;
1256#endif /* CONFIG_PPP_FILTER */
1257
1258 err = ppp_unit_register(ppp, conf->unit, conf->ifname_is_set);
1259 if (err < 0)
1260 goto err2;
1261
1262 conf->file->private_data = &ppp->file;
1263
1264 return 0;
1265err2:
1266 free_percpu(ppp->xmit_recursion);
1267err1:
1268 return err;
1269}
1270
1271static const struct nla_policy ppp_nl_policy[IFLA_PPP_MAX + 1] = {
1272 [IFLA_PPP_DEV_FD] = { .type = NLA_S32 },
1273};
1274
1275static int ppp_nl_validate(struct nlattr *tb[], struct nlattr *data[],
1276 struct netlink_ext_ack *extack)
1277{
1278 if (!data)
1279 return -EINVAL;
1280
1281 if (!data[IFLA_PPP_DEV_FD])
1282 return -EINVAL;
1283 if (nla_get_s32(data[IFLA_PPP_DEV_FD]) < 0)
1284 return -EBADF;
1285
1286 return 0;
1287}
1288
1289static int ppp_nl_newlink(struct net *src_net, struct net_device *dev,
1290 struct nlattr *tb[], struct nlattr *data[],
1291 struct netlink_ext_ack *extack)
1292{
1293 struct ppp_config conf = {
1294 .unit = -1,
1295 .ifname_is_set = true,
1296 };
1297 struct file *file;
1298 int err;
1299
1300 file = fget(nla_get_s32(data[IFLA_PPP_DEV_FD]));
1301 if (!file)
1302 return -EBADF;
1303
1304 /* rtnl_lock is already held here, but ppp_create_interface() locks
1305 * ppp_mutex before holding rtnl_lock. Using mutex_trylock() avoids
1306 * possible deadlock due to lock order inversion, at the cost of
1307 * pushing the problem back to userspace.
1308 */
1309 if (!mutex_trylock(&ppp_mutex)) {
1310 err = -EBUSY;
1311 goto out;
1312 }
1313
1314 if (file->f_op != &ppp_device_fops || file->private_data) {
1315 err = -EBADF;
1316 goto out_unlock;
1317 }
1318
1319 conf.file = file;
1320
1321 /* Don't use device name generated by the rtnetlink layer when ifname
1322 * isn't specified. Let ppp_dev_configure() set the device name using
1323 * the PPP unit identifer as suffix (i.e. ppp<unit_id>). This allows
1324 * userspace to infer the device name using to the PPPIOCGUNIT ioctl.
1325 */
1326 if (!tb[IFLA_IFNAME] || !nla_len(tb[IFLA_IFNAME]) || !*(char *)nla_data(tb[IFLA_IFNAME]))
1327 conf.ifname_is_set = false;
1328
1329 err = ppp_dev_configure(src_net, dev, &conf);
1330
1331out_unlock:
1332 mutex_unlock(&ppp_mutex);
1333out:
1334 fput(file);
1335
1336 return err;
1337}
1338
1339static void ppp_nl_dellink(struct net_device *dev, struct list_head *head)
1340{
1341 unregister_netdevice_queue(dev, head);
1342}
1343
1344static size_t ppp_nl_get_size(const struct net_device *dev)
1345{
1346 return 0;
1347}
1348
1349static int ppp_nl_fill_info(struct sk_buff *skb, const struct net_device *dev)
1350{
1351 return 0;
1352}
1353
1354static struct net *ppp_nl_get_link_net(const struct net_device *dev)
1355{
1356 struct ppp *ppp = netdev_priv(dev);
1357
1358 return ppp->ppp_net;
1359}
1360
1361static struct rtnl_link_ops ppp_link_ops __read_mostly = {
1362 .kind = "ppp",
1363 .maxtype = IFLA_PPP_MAX,
1364 .policy = ppp_nl_policy,
1365 .priv_size = sizeof(struct ppp),
1366 .setup = ppp_setup,
1367 .validate = ppp_nl_validate,
1368 .newlink = ppp_nl_newlink,
1369 .dellink = ppp_nl_dellink,
1370 .get_size = ppp_nl_get_size,
1371 .fill_info = ppp_nl_fill_info,
1372 .get_link_net = ppp_nl_get_link_net,
1373};
1374
1375#define PPP_MAJOR 108
1376
1377/* Called at boot time if ppp is compiled into the kernel,
1378 or at module load time (from init_module) if compiled as a module. */
1379static int __init ppp_init(void)
1380{
1381 int err;
1382
1383 pr_info("PPP generic driver version " PPP_VERSION "\n");
1384
1385 err = register_pernet_device(&ppp_net_ops);
1386 if (err) {
1387 pr_err("failed to register PPP pernet device (%d)\n", err);
1388 goto out;
1389 }
1390
1391 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
1392 if (err) {
1393 pr_err("failed to register PPP device (%d)\n", err);
1394 goto out_net;
1395 }
1396
1397 ppp_class = class_create("ppp");
1398 if (IS_ERR(ppp_class)) {
1399 err = PTR_ERR(ppp_class);
1400 goto out_chrdev;
1401 }
1402
1403 err = rtnl_link_register(&ppp_link_ops);
1404 if (err) {
1405 pr_err("failed to register rtnetlink PPP handler\n");
1406 goto out_class;
1407 }
1408
1409 /* not a big deal if we fail here :-) */
1410 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
1411
1412 return 0;
1413
1414out_class:
1415 class_destroy(ppp_class);
1416out_chrdev:
1417 unregister_chrdev(PPP_MAJOR, "ppp");
1418out_net:
1419 unregister_pernet_device(&ppp_net_ops);
1420out:
1421 return err;
1422}
1423
1424/*
1425 * Network interface unit routines.
1426 */
1427static netdev_tx_t
1428ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
1429{
1430 struct ppp *ppp = netdev_priv(dev);
1431 int npi, proto;
1432 unsigned char *pp;
1433
1434 npi = ethertype_to_npindex(ntohs(skb->protocol));
1435 if (npi < 0)
1436 goto outf;
1437
1438 /* Drop, accept or reject the packet */
1439 switch (ppp->npmode[npi]) {
1440 case NPMODE_PASS:
1441 break;
1442 case NPMODE_QUEUE:
1443 /* it would be nice to have a way to tell the network
1444 system to queue this one up for later. */
1445 goto outf;
1446 case NPMODE_DROP:
1447 case NPMODE_ERROR:
1448 goto outf;
1449 }
1450
1451 /* Put the 2-byte PPP protocol number on the front,
1452 making sure there is room for the address and control fields. */
1453 if (skb_cow_head(skb, PPP_HDRLEN))
1454 goto outf;
1455
1456 pp = skb_push(skb, 2);
1457 proto = npindex_to_proto[npi];
1458 put_unaligned_be16(proto, pp);
1459
1460 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, dev_net(dev)));
1461 ppp_xmit_process(ppp, skb);
1462
1463 return NETDEV_TX_OK;
1464
1465 outf:
1466 kfree_skb(skb);
1467 ++dev->stats.tx_dropped;
1468 return NETDEV_TX_OK;
1469}
1470
1471static int
1472ppp_net_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
1473 void __user *addr, int cmd)
1474{
1475 struct ppp *ppp = netdev_priv(dev);
1476 int err = -EFAULT;
1477 struct ppp_stats stats;
1478 struct ppp_comp_stats cstats;
1479 char *vers;
1480
1481 switch (cmd) {
1482 case SIOCGPPPSTATS:
1483 ppp_get_stats(ppp, &stats);
1484 if (copy_to_user(addr, &stats, sizeof(stats)))
1485 break;
1486 err = 0;
1487 break;
1488
1489 case SIOCGPPPCSTATS:
1490 memset(&cstats, 0, sizeof(cstats));
1491 if (ppp->xc_state)
1492 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
1493 if (ppp->rc_state)
1494 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
1495 if (copy_to_user(addr, &cstats, sizeof(cstats)))
1496 break;
1497 err = 0;
1498 break;
1499
1500 case SIOCGPPPVER:
1501 vers = PPP_VERSION;
1502 if (copy_to_user(addr, vers, strlen(vers) + 1))
1503 break;
1504 err = 0;
1505 break;
1506
1507 default:
1508 err = -EINVAL;
1509 }
1510
1511 return err;
1512}
1513
1514static void
1515ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64)
1516{
1517 struct ppp *ppp = netdev_priv(dev);
1518
1519 ppp_recv_lock(ppp);
1520 stats64->rx_packets = ppp->stats64.rx_packets;
1521 stats64->rx_bytes = ppp->stats64.rx_bytes;
1522 ppp_recv_unlock(ppp);
1523
1524 ppp_xmit_lock(ppp);
1525 stats64->tx_packets = ppp->stats64.tx_packets;
1526 stats64->tx_bytes = ppp->stats64.tx_bytes;
1527 ppp_xmit_unlock(ppp);
1528
1529 stats64->rx_errors = dev->stats.rx_errors;
1530 stats64->tx_errors = dev->stats.tx_errors;
1531 stats64->rx_dropped = dev->stats.rx_dropped;
1532 stats64->tx_dropped = dev->stats.tx_dropped;
1533 stats64->rx_length_errors = dev->stats.rx_length_errors;
1534}
1535
1536static int ppp_dev_init(struct net_device *dev)
1537{
1538 struct ppp *ppp;
1539
1540 netdev_lockdep_set_classes(dev);
1541
1542 ppp = netdev_priv(dev);
1543 /* Let the netdevice take a reference on the ppp file. This ensures
1544 * that ppp_destroy_interface() won't run before the device gets
1545 * unregistered.
1546 */
1547 refcount_inc(&ppp->file.refcnt);
1548
1549 return 0;
1550}
1551
1552static void ppp_dev_uninit(struct net_device *dev)
1553{
1554 struct ppp *ppp = netdev_priv(dev);
1555 struct ppp_net *pn = ppp_pernet(ppp->ppp_net);
1556
1557 ppp_lock(ppp);
1558 ppp->closing = 1;
1559 ppp_unlock(ppp);
1560
1561 mutex_lock(&pn->all_ppp_mutex);
1562 unit_put(&pn->units_idr, ppp->file.index);
1563 mutex_unlock(&pn->all_ppp_mutex);
1564
1565 ppp->owner = NULL;
1566
1567 ppp->file.dead = 1;
1568 wake_up_interruptible(&ppp->file.rwait);
1569}
1570
1571static void ppp_dev_priv_destructor(struct net_device *dev)
1572{
1573 struct ppp *ppp;
1574
1575 ppp = netdev_priv(dev);
1576 if (refcount_dec_and_test(&ppp->file.refcnt))
1577 ppp_destroy_interface(ppp);
1578}
1579
1580static int ppp_fill_forward_path(struct net_device_path_ctx *ctx,
1581 struct net_device_path *path)
1582{
1583 struct ppp *ppp = netdev_priv(ctx->dev);
1584 struct ppp_channel *chan;
1585 struct channel *pch;
1586
1587 if (ppp->flags & SC_MULTILINK)
1588 return -EOPNOTSUPP;
1589
1590 if (list_empty(&ppp->channels))
1591 return -ENODEV;
1592
1593 pch = list_first_entry(&ppp->channels, struct channel, clist);
1594 chan = pch->chan;
1595 if (!chan->ops->fill_forward_path)
1596 return -EOPNOTSUPP;
1597
1598 return chan->ops->fill_forward_path(ctx, path, chan);
1599}
1600
1601static const struct net_device_ops ppp_netdev_ops = {
1602 .ndo_init = ppp_dev_init,
1603 .ndo_uninit = ppp_dev_uninit,
1604 .ndo_start_xmit = ppp_start_xmit,
1605 .ndo_siocdevprivate = ppp_net_siocdevprivate,
1606 .ndo_get_stats64 = ppp_get_stats64,
1607 .ndo_fill_forward_path = ppp_fill_forward_path,
1608};
1609
1610static struct device_type ppp_type = {
1611 .name = "ppp",
1612};
1613
1614static void ppp_setup(struct net_device *dev)
1615{
1616 dev->netdev_ops = &ppp_netdev_ops;
1617 SET_NETDEV_DEVTYPE(dev, &ppp_type);
1618
1619 dev->features |= NETIF_F_LLTX;
1620
1621 dev->hard_header_len = PPP_HDRLEN;
1622 dev->mtu = PPP_MRU;
1623 dev->addr_len = 0;
1624 dev->tx_queue_len = 3;
1625 dev->type = ARPHRD_PPP;
1626 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1627 dev->priv_destructor = ppp_dev_priv_destructor;
1628 netif_keep_dst(dev);
1629}
1630
1631/*
1632 * Transmit-side routines.
1633 */
1634
1635/* Called to do any work queued up on the transmit side that can now be done */
1636static void __ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb)
1637{
1638 ppp_xmit_lock(ppp);
1639 if (!ppp->closing) {
1640 ppp_push(ppp);
1641
1642 if (skb)
1643 skb_queue_tail(&ppp->file.xq, skb);
1644 while (!ppp->xmit_pending &&
1645 (skb = skb_dequeue(&ppp->file.xq)))
1646 ppp_send_frame(ppp, skb);
1647 /* If there's no work left to do, tell the core net
1648 code that we can accept some more. */
1649 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1650 netif_wake_queue(ppp->dev);
1651 else
1652 netif_stop_queue(ppp->dev);
1653 } else {
1654 kfree_skb(skb);
1655 }
1656 ppp_xmit_unlock(ppp);
1657}
1658
1659static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb)
1660{
1661 local_bh_disable();
1662
1663 if (unlikely(*this_cpu_ptr(ppp->xmit_recursion)))
1664 goto err;
1665
1666 (*this_cpu_ptr(ppp->xmit_recursion))++;
1667 __ppp_xmit_process(ppp, skb);
1668 (*this_cpu_ptr(ppp->xmit_recursion))--;
1669
1670 local_bh_enable();
1671
1672 return;
1673
1674err:
1675 local_bh_enable();
1676
1677 kfree_skb(skb);
1678
1679 if (net_ratelimit())
1680 netdev_err(ppp->dev, "recursion detected\n");
1681}
1682
1683static inline struct sk_buff *
1684pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1685{
1686 struct sk_buff *new_skb;
1687 int len;
1688 int new_skb_size = ppp->dev->mtu +
1689 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1690 int compressor_skb_size = ppp->dev->mtu +
1691 ppp->xcomp->comp_extra + PPP_HDRLEN;
1692 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1693 if (!new_skb) {
1694 if (net_ratelimit())
1695 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n");
1696 return NULL;
1697 }
1698 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1699 skb_reserve(new_skb,
1700 ppp->dev->hard_header_len - PPP_HDRLEN);
1701
1702 /* compressor still expects A/C bytes in hdr */
1703 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1704 new_skb->data, skb->len + 2,
1705 compressor_skb_size);
1706 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1707 consume_skb(skb);
1708 skb = new_skb;
1709 skb_put(skb, len);
1710 skb_pull(skb, 2); /* pull off A/C bytes */
1711 } else if (len == 0) {
1712 /* didn't compress, or CCP not up yet */
1713 consume_skb(new_skb);
1714 new_skb = skb;
1715 } else {
1716 /*
1717 * (len < 0)
1718 * MPPE requires that we do not send unencrypted
1719 * frames. The compressor will return -1 if we
1720 * should drop the frame. We cannot simply test
1721 * the compress_proto because MPPE and MPPC share
1722 * the same number.
1723 */
1724 if (net_ratelimit())
1725 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n");
1726 kfree_skb(skb);
1727 consume_skb(new_skb);
1728 new_skb = NULL;
1729 }
1730 return new_skb;
1731}
1732
1733/*
1734 * Compress and send a frame.
1735 * The caller should have locked the xmit path,
1736 * and xmit_pending should be 0.
1737 */
1738static void
1739ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1740{
1741 int proto = PPP_PROTO(skb);
1742 struct sk_buff *new_skb;
1743 int len;
1744 unsigned char *cp;
1745
1746 skb->dev = ppp->dev;
1747
1748 if (proto < 0x8000) {
1749#ifdef CONFIG_PPP_FILTER
1750 /* check if we should pass this packet */
1751 /* the filter instructions are constructed assuming
1752 a four-byte PPP header on each packet */
1753 *(u8 *)skb_push(skb, 2) = 1;
1754 if (ppp->pass_filter &&
1755 bpf_prog_run(ppp->pass_filter, skb) == 0) {
1756 if (ppp->debug & 1)
1757 netdev_printk(KERN_DEBUG, ppp->dev,
1758 "PPP: outbound frame "
1759 "not passed\n");
1760 kfree_skb(skb);
1761 return;
1762 }
1763 /* if this packet passes the active filter, record the time */
1764 if (!(ppp->active_filter &&
1765 bpf_prog_run(ppp->active_filter, skb) == 0))
1766 ppp->last_xmit = jiffies;
1767 skb_pull(skb, 2);
1768#else
1769 /* for data packets, record the time */
1770 ppp->last_xmit = jiffies;
1771#endif /* CONFIG_PPP_FILTER */
1772 }
1773
1774 ++ppp->stats64.tx_packets;
1775 ppp->stats64.tx_bytes += skb->len - PPP_PROTO_LEN;
1776
1777 switch (proto) {
1778 case PPP_IP:
1779 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1780 break;
1781 /* try to do VJ TCP header compression */
1782 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1783 GFP_ATOMIC);
1784 if (!new_skb) {
1785 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n");
1786 goto drop;
1787 }
1788 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1789 cp = skb->data + 2;
1790 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1791 new_skb->data + 2, &cp,
1792 !(ppp->flags & SC_NO_TCP_CCID));
1793 if (cp == skb->data + 2) {
1794 /* didn't compress */
1795 consume_skb(new_skb);
1796 } else {
1797 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1798 proto = PPP_VJC_COMP;
1799 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1800 } else {
1801 proto = PPP_VJC_UNCOMP;
1802 cp[0] = skb->data[2];
1803 }
1804 consume_skb(skb);
1805 skb = new_skb;
1806 cp = skb_put(skb, len + 2);
1807 cp[0] = 0;
1808 cp[1] = proto;
1809 }
1810 break;
1811
1812 case PPP_CCP:
1813 /* peek at outbound CCP frames */
1814 ppp_ccp_peek(ppp, skb, 0);
1815 break;
1816 }
1817
1818 /* try to do packet compression */
1819 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state &&
1820 proto != PPP_LCP && proto != PPP_CCP) {
1821 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1822 if (net_ratelimit())
1823 netdev_err(ppp->dev,
1824 "ppp: compression required but "
1825 "down - pkt dropped.\n");
1826 goto drop;
1827 }
1828 skb = pad_compress_skb(ppp, skb);
1829 if (!skb)
1830 goto drop;
1831 }
1832
1833 /*
1834 * If we are waiting for traffic (demand dialling),
1835 * queue it up for pppd to receive.
1836 */
1837 if (ppp->flags & SC_LOOP_TRAFFIC) {
1838 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1839 goto drop;
1840 skb_queue_tail(&ppp->file.rq, skb);
1841 wake_up_interruptible(&ppp->file.rwait);
1842 return;
1843 }
1844
1845 ppp->xmit_pending = skb;
1846 ppp_push(ppp);
1847 return;
1848
1849 drop:
1850 kfree_skb(skb);
1851 ++ppp->dev->stats.tx_errors;
1852}
1853
1854/*
1855 * Try to send the frame in xmit_pending.
1856 * The caller should have the xmit path locked.
1857 */
1858static void
1859ppp_push(struct ppp *ppp)
1860{
1861 struct list_head *list;
1862 struct channel *pch;
1863 struct sk_buff *skb = ppp->xmit_pending;
1864
1865 if (!skb)
1866 return;
1867
1868 list = &ppp->channels;
1869 if (list_empty(list)) {
1870 /* nowhere to send the packet, just drop it */
1871 ppp->xmit_pending = NULL;
1872 kfree_skb(skb);
1873 return;
1874 }
1875
1876 if ((ppp->flags & SC_MULTILINK) == 0) {
1877 /* not doing multilink: send it down the first channel */
1878 list = list->next;
1879 pch = list_entry(list, struct channel, clist);
1880
1881 spin_lock(&pch->downl);
1882 if (pch->chan) {
1883 if (pch->chan->ops->start_xmit(pch->chan, skb))
1884 ppp->xmit_pending = NULL;
1885 } else {
1886 /* channel got unregistered */
1887 kfree_skb(skb);
1888 ppp->xmit_pending = NULL;
1889 }
1890 spin_unlock(&pch->downl);
1891 return;
1892 }
1893
1894#ifdef CONFIG_PPP_MULTILINK
1895 /* Multilink: fragment the packet over as many links
1896 as can take the packet at the moment. */
1897 if (!ppp_mp_explode(ppp, skb))
1898 return;
1899#endif /* CONFIG_PPP_MULTILINK */
1900
1901 ppp->xmit_pending = NULL;
1902 kfree_skb(skb);
1903}
1904
1905#ifdef CONFIG_PPP_MULTILINK
1906static bool mp_protocol_compress __read_mostly = true;
1907module_param(mp_protocol_compress, bool, 0644);
1908MODULE_PARM_DESC(mp_protocol_compress,
1909 "compress protocol id in multilink fragments");
1910
1911/*
1912 * Divide a packet to be transmitted into fragments and
1913 * send them out the individual links.
1914 */
1915static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1916{
1917 int len, totlen;
1918 int i, bits, hdrlen, mtu;
1919 int flen;
1920 int navail, nfree, nzero;
1921 int nbigger;
1922 int totspeed;
1923 int totfree;
1924 unsigned char *p, *q;
1925 struct list_head *list;
1926 struct channel *pch;
1927 struct sk_buff *frag;
1928 struct ppp_channel *chan;
1929
1930 totspeed = 0; /*total bitrate of the bundle*/
1931 nfree = 0; /* # channels which have no packet already queued */
1932 navail = 0; /* total # of usable channels (not deregistered) */
1933 nzero = 0; /* number of channels with zero speed associated*/
1934 totfree = 0; /*total # of channels available and
1935 *having no queued packets before
1936 *starting the fragmentation*/
1937
1938 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1939 i = 0;
1940 list_for_each_entry(pch, &ppp->channels, clist) {
1941 if (pch->chan) {
1942 pch->avail = 1;
1943 navail++;
1944 pch->speed = pch->chan->speed;
1945 } else {
1946 pch->avail = 0;
1947 }
1948 if (pch->avail) {
1949 if (skb_queue_empty(&pch->file.xq) ||
1950 !pch->had_frag) {
1951 if (pch->speed == 0)
1952 nzero++;
1953 else
1954 totspeed += pch->speed;
1955
1956 pch->avail = 2;
1957 ++nfree;
1958 ++totfree;
1959 }
1960 if (!pch->had_frag && i < ppp->nxchan)
1961 ppp->nxchan = i;
1962 }
1963 ++i;
1964 }
1965 /*
1966 * Don't start sending this packet unless at least half of
1967 * the channels are free. This gives much better TCP
1968 * performance if we have a lot of channels.
1969 */
1970 if (nfree == 0 || nfree < navail / 2)
1971 return 0; /* can't take now, leave it in xmit_pending */
1972
1973 /* Do protocol field compression */
1974 p = skb->data;
1975 len = skb->len;
1976 if (*p == 0 && mp_protocol_compress) {
1977 ++p;
1978 --len;
1979 }
1980
1981 totlen = len;
1982 nbigger = len % nfree;
1983
1984 /* skip to the channel after the one we last used
1985 and start at that one */
1986 list = &ppp->channels;
1987 for (i = 0; i < ppp->nxchan; ++i) {
1988 list = list->next;
1989 if (list == &ppp->channels) {
1990 i = 0;
1991 break;
1992 }
1993 }
1994
1995 /* create a fragment for each channel */
1996 bits = B;
1997 while (len > 0) {
1998 list = list->next;
1999 if (list == &ppp->channels) {
2000 i = 0;
2001 continue;
2002 }
2003 pch = list_entry(list, struct channel, clist);
2004 ++i;
2005 if (!pch->avail)
2006 continue;
2007
2008 /*
2009 * Skip this channel if it has a fragment pending already and
2010 * we haven't given a fragment to all of the free channels.
2011 */
2012 if (pch->avail == 1) {
2013 if (nfree > 0)
2014 continue;
2015 } else {
2016 pch->avail = 1;
2017 }
2018
2019 /* check the channel's mtu and whether it is still attached. */
2020 spin_lock(&pch->downl);
2021 if (pch->chan == NULL) {
2022 /* can't use this channel, it's being deregistered */
2023 if (pch->speed == 0)
2024 nzero--;
2025 else
2026 totspeed -= pch->speed;
2027
2028 spin_unlock(&pch->downl);
2029 pch->avail = 0;
2030 totlen = len;
2031 totfree--;
2032 nfree--;
2033 if (--navail == 0)
2034 break;
2035 continue;
2036 }
2037
2038 /*
2039 *if the channel speed is not set divide
2040 *the packet evenly among the free channels;
2041 *otherwise divide it according to the speed
2042 *of the channel we are going to transmit on
2043 */
2044 flen = len;
2045 if (nfree > 0) {
2046 if (pch->speed == 0) {
2047 flen = len/nfree;
2048 if (nbigger > 0) {
2049 flen++;
2050 nbigger--;
2051 }
2052 } else {
2053 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
2054 ((totspeed*totfree)/pch->speed)) - hdrlen;
2055 if (nbigger > 0) {
2056 flen += ((totfree - nzero)*pch->speed)/totspeed;
2057 nbigger -= ((totfree - nzero)*pch->speed)/
2058 totspeed;
2059 }
2060 }
2061 nfree--;
2062 }
2063
2064 /*
2065 *check if we are on the last channel or
2066 *we exceded the length of the data to
2067 *fragment
2068 */
2069 if ((nfree <= 0) || (flen > len))
2070 flen = len;
2071 /*
2072 *it is not worth to tx on slow channels:
2073 *in that case from the resulting flen according to the
2074 *above formula will be equal or less than zero.
2075 *Skip the channel in this case
2076 */
2077 if (flen <= 0) {
2078 pch->avail = 2;
2079 spin_unlock(&pch->downl);
2080 continue;
2081 }
2082
2083 /*
2084 * hdrlen includes the 2-byte PPP protocol field, but the
2085 * MTU counts only the payload excluding the protocol field.
2086 * (RFC1661 Section 2)
2087 */
2088 mtu = pch->chan->mtu - (hdrlen - 2);
2089 if (mtu < 4)
2090 mtu = 4;
2091 if (flen > mtu)
2092 flen = mtu;
2093 if (flen == len)
2094 bits |= E;
2095 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
2096 if (!frag)
2097 goto noskb;
2098 q = skb_put(frag, flen + hdrlen);
2099
2100 /* make the MP header */
2101 put_unaligned_be16(PPP_MP, q);
2102 if (ppp->flags & SC_MP_XSHORTSEQ) {
2103 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
2104 q[3] = ppp->nxseq;
2105 } else {
2106 q[2] = bits;
2107 q[3] = ppp->nxseq >> 16;
2108 q[4] = ppp->nxseq >> 8;
2109 q[5] = ppp->nxseq;
2110 }
2111
2112 memcpy(q + hdrlen, p, flen);
2113
2114 /* try to send it down the channel */
2115 chan = pch->chan;
2116 if (!skb_queue_empty(&pch->file.xq) ||
2117 !chan->ops->start_xmit(chan, frag))
2118 skb_queue_tail(&pch->file.xq, frag);
2119 pch->had_frag = 1;
2120 p += flen;
2121 len -= flen;
2122 ++ppp->nxseq;
2123 bits = 0;
2124 spin_unlock(&pch->downl);
2125 }
2126 ppp->nxchan = i;
2127
2128 return 1;
2129
2130 noskb:
2131 spin_unlock(&pch->downl);
2132 if (ppp->debug & 1)
2133 netdev_err(ppp->dev, "PPP: no memory (fragment)\n");
2134 ++ppp->dev->stats.tx_errors;
2135 ++ppp->nxseq;
2136 return 1; /* abandon the frame */
2137}
2138#endif /* CONFIG_PPP_MULTILINK */
2139
2140/* Try to send data out on a channel */
2141static void __ppp_channel_push(struct channel *pch)
2142{
2143 struct sk_buff *skb;
2144 struct ppp *ppp;
2145
2146 spin_lock(&pch->downl);
2147 if (pch->chan) {
2148 while (!skb_queue_empty(&pch->file.xq)) {
2149 skb = skb_dequeue(&pch->file.xq);
2150 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
2151 /* put the packet back and try again later */
2152 skb_queue_head(&pch->file.xq, skb);
2153 break;
2154 }
2155 }
2156 } else {
2157 /* channel got deregistered */
2158 skb_queue_purge(&pch->file.xq);
2159 }
2160 spin_unlock(&pch->downl);
2161 /* see if there is anything from the attached unit to be sent */
2162 if (skb_queue_empty(&pch->file.xq)) {
2163 ppp = pch->ppp;
2164 if (ppp)
2165 __ppp_xmit_process(ppp, NULL);
2166 }
2167}
2168
2169static void ppp_channel_push(struct channel *pch)
2170{
2171 read_lock_bh(&pch->upl);
2172 if (pch->ppp) {
2173 (*this_cpu_ptr(pch->ppp->xmit_recursion))++;
2174 __ppp_channel_push(pch);
2175 (*this_cpu_ptr(pch->ppp->xmit_recursion))--;
2176 } else {
2177 __ppp_channel_push(pch);
2178 }
2179 read_unlock_bh(&pch->upl);
2180}
2181
2182/*
2183 * Receive-side routines.
2184 */
2185
2186struct ppp_mp_skb_parm {
2187 u32 sequence;
2188 u8 BEbits;
2189};
2190#define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb))
2191
2192static inline void
2193ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
2194{
2195 ppp_recv_lock(ppp);
2196 if (!ppp->closing)
2197 ppp_receive_frame(ppp, skb, pch);
2198 else
2199 kfree_skb(skb);
2200 ppp_recv_unlock(ppp);
2201}
2202
2203/**
2204 * __ppp_decompress_proto - Decompress protocol field, slim version.
2205 * @skb: Socket buffer where protocol field should be decompressed. It must have
2206 * at least 1 byte of head room and 1 byte of linear data. First byte of
2207 * data must be a protocol field byte.
2208 *
2209 * Decompress protocol field in PPP header if it's compressed, e.g. when
2210 * Protocol-Field-Compression (PFC) was negotiated. No checks w.r.t. skb data
2211 * length are done in this function.
2212 */
2213static void __ppp_decompress_proto(struct sk_buff *skb)
2214{
2215 if (skb->data[0] & 0x01)
2216 *(u8 *)skb_push(skb, 1) = 0x00;
2217}
2218
2219/**
2220 * ppp_decompress_proto - Check skb data room and decompress protocol field.
2221 * @skb: Socket buffer where protocol field should be decompressed. First byte
2222 * of data must be a protocol field byte.
2223 *
2224 * Decompress protocol field in PPP header if it's compressed, e.g. when
2225 * Protocol-Field-Compression (PFC) was negotiated. This function also makes
2226 * sure that skb data room is sufficient for Protocol field, before and after
2227 * decompression.
2228 *
2229 * Return: true - decompressed successfully, false - not enough room in skb.
2230 */
2231static bool ppp_decompress_proto(struct sk_buff *skb)
2232{
2233 /* At least one byte should be present (if protocol is compressed) */
2234 if (!pskb_may_pull(skb, 1))
2235 return false;
2236
2237 __ppp_decompress_proto(skb);
2238
2239 /* Protocol field should occupy 2 bytes when not compressed */
2240 return pskb_may_pull(skb, 2);
2241}
2242
2243/* Attempt to handle a frame via. a bridged channel, if one exists.
2244 * If the channel is bridged, the frame is consumed by the bridge.
2245 * If not, the caller must handle the frame by normal recv mechanisms.
2246 * Returns true if the frame is consumed, false otherwise.
2247 */
2248static bool ppp_channel_bridge_input(struct channel *pch, struct sk_buff *skb)
2249{
2250 struct channel *pchb;
2251
2252 rcu_read_lock();
2253 pchb = rcu_dereference(pch->bridge);
2254 if (!pchb)
2255 goto out_rcu;
2256
2257 spin_lock(&pchb->downl);
2258 if (!pchb->chan) {
2259 /* channel got unregistered */
2260 kfree_skb(skb);
2261 goto outl;
2262 }
2263
2264 skb_scrub_packet(skb, !net_eq(pch->chan_net, pchb->chan_net));
2265 if (!pchb->chan->ops->start_xmit(pchb->chan, skb))
2266 kfree_skb(skb);
2267
2268outl:
2269 spin_unlock(&pchb->downl);
2270out_rcu:
2271 rcu_read_unlock();
2272
2273 /* If pchb is set then we've consumed the packet */
2274 return !!pchb;
2275}
2276
2277void
2278ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
2279{
2280 struct channel *pch = chan->ppp;
2281 int proto;
2282
2283 if (!pch) {
2284 kfree_skb(skb);
2285 return;
2286 }
2287
2288 /* If the channel is bridged, transmit via. bridge */
2289 if (ppp_channel_bridge_input(pch, skb))
2290 return;
2291
2292 read_lock_bh(&pch->upl);
2293 if (!ppp_decompress_proto(skb)) {
2294 kfree_skb(skb);
2295 if (pch->ppp) {
2296 ++pch->ppp->dev->stats.rx_length_errors;
2297 ppp_receive_error(pch->ppp);
2298 }
2299 goto done;
2300 }
2301
2302 proto = PPP_PROTO(skb);
2303 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
2304 /* put it on the channel queue */
2305 skb_queue_tail(&pch->file.rq, skb);
2306 /* drop old frames if queue too long */
2307 while (pch->file.rq.qlen > PPP_MAX_RQLEN &&
2308 (skb = skb_dequeue(&pch->file.rq)))
2309 kfree_skb(skb);
2310 wake_up_interruptible(&pch->file.rwait);
2311 } else {
2312 ppp_do_recv(pch->ppp, skb, pch);
2313 }
2314
2315done:
2316 read_unlock_bh(&pch->upl);
2317}
2318
2319/* Put a 0-length skb in the receive queue as an error indication */
2320void
2321ppp_input_error(struct ppp_channel *chan, int code)
2322{
2323 struct channel *pch = chan->ppp;
2324 struct sk_buff *skb;
2325
2326 if (!pch)
2327 return;
2328
2329 read_lock_bh(&pch->upl);
2330 if (pch->ppp) {
2331 skb = alloc_skb(0, GFP_ATOMIC);
2332 if (skb) {
2333 skb->len = 0; /* probably unnecessary */
2334 skb->cb[0] = code;
2335 ppp_do_recv(pch->ppp, skb, pch);
2336 }
2337 }
2338 read_unlock_bh(&pch->upl);
2339}
2340
2341/*
2342 * We come in here to process a received frame.
2343 * The receive side of the ppp unit is locked.
2344 */
2345static void
2346ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
2347{
2348 /* note: a 0-length skb is used as an error indication */
2349 if (skb->len > 0) {
2350 skb_checksum_complete_unset(skb);
2351#ifdef CONFIG_PPP_MULTILINK
2352 /* XXX do channel-level decompression here */
2353 if (PPP_PROTO(skb) == PPP_MP)
2354 ppp_receive_mp_frame(ppp, skb, pch);
2355 else
2356#endif /* CONFIG_PPP_MULTILINK */
2357 ppp_receive_nonmp_frame(ppp, skb);
2358 } else {
2359 kfree_skb(skb);
2360 ppp_receive_error(ppp);
2361 }
2362}
2363
2364static void
2365ppp_receive_error(struct ppp *ppp)
2366{
2367 ++ppp->dev->stats.rx_errors;
2368 if (ppp->vj)
2369 slhc_toss(ppp->vj);
2370}
2371
2372static void
2373ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
2374{
2375 struct sk_buff *ns;
2376 int proto, len, npi;
2377
2378 /*
2379 * Decompress the frame, if compressed.
2380 * Note that some decompressors need to see uncompressed frames
2381 * that come in as well as compressed frames.
2382 */
2383 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) &&
2384 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
2385 skb = ppp_decompress_frame(ppp, skb);
2386
2387 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
2388 goto err;
2389
2390 /* At this point the "Protocol" field MUST be decompressed, either in
2391 * ppp_input(), ppp_decompress_frame() or in ppp_receive_mp_frame().
2392 */
2393 proto = PPP_PROTO(skb);
2394 switch (proto) {
2395 case PPP_VJC_COMP:
2396 /* decompress VJ compressed packets */
2397 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
2398 goto err;
2399
2400 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
2401 /* copy to a new sk_buff with more tailroom */
2402 ns = dev_alloc_skb(skb->len + 128);
2403 if (!ns) {
2404 netdev_err(ppp->dev, "PPP: no memory "
2405 "(VJ decomp)\n");
2406 goto err;
2407 }
2408 skb_reserve(ns, 2);
2409 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
2410 consume_skb(skb);
2411 skb = ns;
2412 }
2413 else
2414 skb->ip_summed = CHECKSUM_NONE;
2415
2416 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
2417 if (len <= 0) {
2418 netdev_printk(KERN_DEBUG, ppp->dev,
2419 "PPP: VJ decompression error\n");
2420 goto err;
2421 }
2422 len += 2;
2423 if (len > skb->len)
2424 skb_put(skb, len - skb->len);
2425 else if (len < skb->len)
2426 skb_trim(skb, len);
2427 proto = PPP_IP;
2428 break;
2429
2430 case PPP_VJC_UNCOMP:
2431 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
2432 goto err;
2433
2434 /* Until we fix the decompressor need to make sure
2435 * data portion is linear.
2436 */
2437 if (!pskb_may_pull(skb, skb->len))
2438 goto err;
2439
2440 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
2441 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n");
2442 goto err;
2443 }
2444 proto = PPP_IP;
2445 break;
2446
2447 case PPP_CCP:
2448 ppp_ccp_peek(ppp, skb, 1);
2449 break;
2450 }
2451
2452 ++ppp->stats64.rx_packets;
2453 ppp->stats64.rx_bytes += skb->len - 2;
2454
2455 npi = proto_to_npindex(proto);
2456 if (npi < 0) {
2457 /* control or unknown frame - pass it to pppd */
2458 skb_queue_tail(&ppp->file.rq, skb);
2459 /* limit queue length by dropping old frames */
2460 while (ppp->file.rq.qlen > PPP_MAX_RQLEN &&
2461 (skb = skb_dequeue(&ppp->file.rq)))
2462 kfree_skb(skb);
2463 /* wake up any process polling or blocking on read */
2464 wake_up_interruptible(&ppp->file.rwait);
2465
2466 } else {
2467 /* network protocol frame - give it to the kernel */
2468
2469#ifdef CONFIG_PPP_FILTER
2470 /* check if the packet passes the pass and active filters */
2471 /* the filter instructions are constructed assuming
2472 a four-byte PPP header on each packet */
2473 if (ppp->pass_filter || ppp->active_filter) {
2474 if (skb_unclone(skb, GFP_ATOMIC))
2475 goto err;
2476
2477 *(u8 *)skb_push(skb, 2) = 0;
2478 if (ppp->pass_filter &&
2479 bpf_prog_run(ppp->pass_filter, skb) == 0) {
2480 if (ppp->debug & 1)
2481 netdev_printk(KERN_DEBUG, ppp->dev,
2482 "PPP: inbound frame "
2483 "not passed\n");
2484 kfree_skb(skb);
2485 return;
2486 }
2487 if (!(ppp->active_filter &&
2488 bpf_prog_run(ppp->active_filter, skb) == 0))
2489 ppp->last_recv = jiffies;
2490 __skb_pull(skb, 2);
2491 } else
2492#endif /* CONFIG_PPP_FILTER */
2493 ppp->last_recv = jiffies;
2494
2495 if ((ppp->dev->flags & IFF_UP) == 0 ||
2496 ppp->npmode[npi] != NPMODE_PASS) {
2497 kfree_skb(skb);
2498 } else {
2499 /* chop off protocol */
2500 skb_pull_rcsum(skb, 2);
2501 skb->dev = ppp->dev;
2502 skb->protocol = htons(npindex_to_ethertype[npi]);
2503 skb_reset_mac_header(skb);
2504 skb_scrub_packet(skb, !net_eq(ppp->ppp_net,
2505 dev_net(ppp->dev)));
2506 netif_rx(skb);
2507 }
2508 }
2509 return;
2510
2511 err:
2512 kfree_skb(skb);
2513 ppp_receive_error(ppp);
2514}
2515
2516static struct sk_buff *
2517ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
2518{
2519 int proto = PPP_PROTO(skb);
2520 struct sk_buff *ns;
2521 int len;
2522
2523 /* Until we fix all the decompressor's need to make sure
2524 * data portion is linear.
2525 */
2526 if (!pskb_may_pull(skb, skb->len))
2527 goto err;
2528
2529 if (proto == PPP_COMP) {
2530 int obuff_size;
2531
2532 switch(ppp->rcomp->compress_proto) {
2533 case CI_MPPE:
2534 obuff_size = ppp->mru + PPP_HDRLEN + 1;
2535 break;
2536 default:
2537 obuff_size = ppp->mru + PPP_HDRLEN;
2538 break;
2539 }
2540
2541 ns = dev_alloc_skb(obuff_size);
2542 if (!ns) {
2543 netdev_err(ppp->dev, "ppp_decompress_frame: "
2544 "no memory\n");
2545 goto err;
2546 }
2547 /* the decompressor still expects the A/C bytes in the hdr */
2548 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
2549 skb->len + 2, ns->data, obuff_size);
2550 if (len < 0) {
2551 /* Pass the compressed frame to pppd as an
2552 error indication. */
2553 if (len == DECOMP_FATALERROR)
2554 ppp->rstate |= SC_DC_FERROR;
2555 kfree_skb(ns);
2556 goto err;
2557 }
2558
2559 consume_skb(skb);
2560 skb = ns;
2561 skb_put(skb, len);
2562 skb_pull(skb, 2); /* pull off the A/C bytes */
2563
2564 /* Don't call __ppp_decompress_proto() here, but instead rely on
2565 * corresponding algo (mppe/bsd/deflate) to decompress it.
2566 */
2567 } else {
2568 /* Uncompressed frame - pass to decompressor so it
2569 can update its dictionary if necessary. */
2570 if (ppp->rcomp->incomp)
2571 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
2572 skb->len + 2);
2573 }
2574
2575 return skb;
2576
2577 err:
2578 ppp->rstate |= SC_DC_ERROR;
2579 ppp_receive_error(ppp);
2580 return skb;
2581}
2582
2583#ifdef CONFIG_PPP_MULTILINK
2584/*
2585 * Receive a multilink frame.
2586 * We put it on the reconstruction queue and then pull off
2587 * as many completed frames as we can.
2588 */
2589static void
2590ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
2591{
2592 u32 mask, seq;
2593 struct channel *ch;
2594 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
2595
2596 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
2597 goto err; /* no good, throw it away */
2598
2599 /* Decode sequence number and begin/end bits */
2600 if (ppp->flags & SC_MP_SHORTSEQ) {
2601 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
2602 mask = 0xfff;
2603 } else {
2604 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
2605 mask = 0xffffff;
2606 }
2607 PPP_MP_CB(skb)->BEbits = skb->data[2];
2608 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
2609
2610 /*
2611 * Do protocol ID decompression on the first fragment of each packet.
2612 * We have to do that here, because ppp_receive_nonmp_frame() expects
2613 * decompressed protocol field.
2614 */
2615 if (PPP_MP_CB(skb)->BEbits & B)
2616 __ppp_decompress_proto(skb);
2617
2618 /*
2619 * Expand sequence number to 32 bits, making it as close
2620 * as possible to ppp->minseq.
2621 */
2622 seq |= ppp->minseq & ~mask;
2623 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
2624 seq += mask + 1;
2625 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
2626 seq -= mask + 1; /* should never happen */
2627 PPP_MP_CB(skb)->sequence = seq;
2628 pch->lastseq = seq;
2629
2630 /*
2631 * If this packet comes before the next one we were expecting,
2632 * drop it.
2633 */
2634 if (seq_before(seq, ppp->nextseq)) {
2635 kfree_skb(skb);
2636 ++ppp->dev->stats.rx_dropped;
2637 ppp_receive_error(ppp);
2638 return;
2639 }
2640
2641 /*
2642 * Reevaluate minseq, the minimum over all channels of the
2643 * last sequence number received on each channel. Because of
2644 * the increasing sequence number rule, we know that any fragment
2645 * before `minseq' which hasn't arrived is never going to arrive.
2646 * The list of channels can't change because we have the receive
2647 * side of the ppp unit locked.
2648 */
2649 list_for_each_entry(ch, &ppp->channels, clist) {
2650 if (seq_before(ch->lastseq, seq))
2651 seq = ch->lastseq;
2652 }
2653 if (seq_before(ppp->minseq, seq))
2654 ppp->minseq = seq;
2655
2656 /* Put the fragment on the reconstruction queue */
2657 ppp_mp_insert(ppp, skb);
2658
2659 /* If the queue is getting long, don't wait any longer for packets
2660 before the start of the queue. */
2661 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
2662 struct sk_buff *mskb = skb_peek(&ppp->mrq);
2663 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence))
2664 ppp->minseq = PPP_MP_CB(mskb)->sequence;
2665 }
2666
2667 /* Pull completed packets off the queue and receive them. */
2668 while ((skb = ppp_mp_reconstruct(ppp))) {
2669 if (pskb_may_pull(skb, 2))
2670 ppp_receive_nonmp_frame(ppp, skb);
2671 else {
2672 ++ppp->dev->stats.rx_length_errors;
2673 kfree_skb(skb);
2674 ppp_receive_error(ppp);
2675 }
2676 }
2677
2678 return;
2679
2680 err:
2681 kfree_skb(skb);
2682 ppp_receive_error(ppp);
2683}
2684
2685/*
2686 * Insert a fragment on the MP reconstruction queue.
2687 * The queue is ordered by increasing sequence number.
2688 */
2689static void
2690ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
2691{
2692 struct sk_buff *p;
2693 struct sk_buff_head *list = &ppp->mrq;
2694 u32 seq = PPP_MP_CB(skb)->sequence;
2695
2696 /* N.B. we don't need to lock the list lock because we have the
2697 ppp unit receive-side lock. */
2698 skb_queue_walk(list, p) {
2699 if (seq_before(seq, PPP_MP_CB(p)->sequence))
2700 break;
2701 }
2702 __skb_queue_before(list, p, skb);
2703}
2704
2705/*
2706 * Reconstruct a packet from the MP fragment queue.
2707 * We go through increasing sequence numbers until we find a
2708 * complete packet, or we get to the sequence number for a fragment
2709 * which hasn't arrived but might still do so.
2710 */
2711static struct sk_buff *
2712ppp_mp_reconstruct(struct ppp *ppp)
2713{
2714 u32 seq = ppp->nextseq;
2715 u32 minseq = ppp->minseq;
2716 struct sk_buff_head *list = &ppp->mrq;
2717 struct sk_buff *p, *tmp;
2718 struct sk_buff *head, *tail;
2719 struct sk_buff *skb = NULL;
2720 int lost = 0, len = 0;
2721
2722 if (ppp->mrru == 0) /* do nothing until mrru is set */
2723 return NULL;
2724 head = __skb_peek(list);
2725 tail = NULL;
2726 skb_queue_walk_safe(list, p, tmp) {
2727 again:
2728 if (seq_before(PPP_MP_CB(p)->sequence, seq)) {
2729 /* this can't happen, anyway ignore the skb */
2730 netdev_err(ppp->dev, "ppp_mp_reconstruct bad "
2731 "seq %u < %u\n",
2732 PPP_MP_CB(p)->sequence, seq);
2733 __skb_unlink(p, list);
2734 kfree_skb(p);
2735 continue;
2736 }
2737 if (PPP_MP_CB(p)->sequence != seq) {
2738 u32 oldseq;
2739 /* Fragment `seq' is missing. If it is after
2740 minseq, it might arrive later, so stop here. */
2741 if (seq_after(seq, minseq))
2742 break;
2743 /* Fragment `seq' is lost, keep going. */
2744 lost = 1;
2745 oldseq = seq;
2746 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)?
2747 minseq + 1: PPP_MP_CB(p)->sequence;
2748
2749 if (ppp->debug & 1)
2750 netdev_printk(KERN_DEBUG, ppp->dev,
2751 "lost frag %u..%u\n",
2752 oldseq, seq-1);
2753
2754 goto again;
2755 }
2756
2757 /*
2758 * At this point we know that all the fragments from
2759 * ppp->nextseq to seq are either present or lost.
2760 * Also, there are no complete packets in the queue
2761 * that have no missing fragments and end before this
2762 * fragment.
2763 */
2764
2765 /* B bit set indicates this fragment starts a packet */
2766 if (PPP_MP_CB(p)->BEbits & B) {
2767 head = p;
2768 lost = 0;
2769 len = 0;
2770 }
2771
2772 len += p->len;
2773
2774 /* Got a complete packet yet? */
2775 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) &&
2776 (PPP_MP_CB(head)->BEbits & B)) {
2777 if (len > ppp->mrru + 2) {
2778 ++ppp->dev->stats.rx_length_errors;
2779 netdev_printk(KERN_DEBUG, ppp->dev,
2780 "PPP: reconstructed packet"
2781 " is too long (%d)\n", len);
2782 } else {
2783 tail = p;
2784 break;
2785 }
2786 ppp->nextseq = seq + 1;
2787 }
2788
2789 /*
2790 * If this is the ending fragment of a packet,
2791 * and we haven't found a complete valid packet yet,
2792 * we can discard up to and including this fragment.
2793 */
2794 if (PPP_MP_CB(p)->BEbits & E) {
2795 struct sk_buff *tmp2;
2796
2797 skb_queue_reverse_walk_from_safe(list, p, tmp2) {
2798 if (ppp->debug & 1)
2799 netdev_printk(KERN_DEBUG, ppp->dev,
2800 "discarding frag %u\n",
2801 PPP_MP_CB(p)->sequence);
2802 __skb_unlink(p, list);
2803 kfree_skb(p);
2804 }
2805 head = skb_peek(list);
2806 if (!head)
2807 break;
2808 }
2809 ++seq;
2810 }
2811
2812 /* If we have a complete packet, copy it all into one skb. */
2813 if (tail != NULL) {
2814 /* If we have discarded any fragments,
2815 signal a receive error. */
2816 if (PPP_MP_CB(head)->sequence != ppp->nextseq) {
2817 skb_queue_walk_safe(list, p, tmp) {
2818 if (p == head)
2819 break;
2820 if (ppp->debug & 1)
2821 netdev_printk(KERN_DEBUG, ppp->dev,
2822 "discarding frag %u\n",
2823 PPP_MP_CB(p)->sequence);
2824 __skb_unlink(p, list);
2825 kfree_skb(p);
2826 }
2827
2828 if (ppp->debug & 1)
2829 netdev_printk(KERN_DEBUG, ppp->dev,
2830 " missed pkts %u..%u\n",
2831 ppp->nextseq,
2832 PPP_MP_CB(head)->sequence-1);
2833 ++ppp->dev->stats.rx_dropped;
2834 ppp_receive_error(ppp);
2835 }
2836
2837 skb = head;
2838 if (head != tail) {
2839 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list;
2840 p = skb_queue_next(list, head);
2841 __skb_unlink(skb, list);
2842 skb_queue_walk_from_safe(list, p, tmp) {
2843 __skb_unlink(p, list);
2844 *fragpp = p;
2845 p->next = NULL;
2846 fragpp = &p->next;
2847
2848 skb->len += p->len;
2849 skb->data_len += p->len;
2850 skb->truesize += p->truesize;
2851
2852 if (p == tail)
2853 break;
2854 }
2855 } else {
2856 __skb_unlink(skb, list);
2857 }
2858
2859 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1;
2860 }
2861
2862 return skb;
2863}
2864#endif /* CONFIG_PPP_MULTILINK */
2865
2866/*
2867 * Channel interface.
2868 */
2869
2870/* Create a new, unattached ppp channel. */
2871int ppp_register_channel(struct ppp_channel *chan)
2872{
2873 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2874}
2875
2876/* Create a new, unattached ppp channel for specified net. */
2877int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
2878{
2879 struct channel *pch;
2880 struct ppp_net *pn;
2881
2882 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2883 if (!pch)
2884 return -ENOMEM;
2885
2886 pn = ppp_pernet(net);
2887
2888 pch->ppp = NULL;
2889 pch->chan = chan;
2890 pch->chan_net = get_net_track(net, &pch->ns_tracker, GFP_KERNEL);
2891 chan->ppp = pch;
2892 init_ppp_file(&pch->file, CHANNEL);
2893 pch->file.hdrlen = chan->hdrlen;
2894#ifdef CONFIG_PPP_MULTILINK
2895 pch->lastseq = -1;
2896#endif /* CONFIG_PPP_MULTILINK */
2897 init_rwsem(&pch->chan_sem);
2898 spin_lock_init(&pch->downl);
2899 rwlock_init(&pch->upl);
2900
2901 spin_lock_bh(&pn->all_channels_lock);
2902 pch->file.index = ++pn->last_channel_index;
2903 list_add(&pch->list, &pn->new_channels);
2904 atomic_inc(&channel_count);
2905 spin_unlock_bh(&pn->all_channels_lock);
2906
2907 return 0;
2908}
2909
2910/*
2911 * Return the index of a channel.
2912 */
2913int ppp_channel_index(struct ppp_channel *chan)
2914{
2915 struct channel *pch = chan->ppp;
2916
2917 if (pch)
2918 return pch->file.index;
2919 return -1;
2920}
2921
2922/*
2923 * Return the PPP unit number to which a channel is connected.
2924 */
2925int ppp_unit_number(struct ppp_channel *chan)
2926{
2927 struct channel *pch = chan->ppp;
2928 int unit = -1;
2929
2930 if (pch) {
2931 read_lock_bh(&pch->upl);
2932 if (pch->ppp)
2933 unit = pch->ppp->file.index;
2934 read_unlock_bh(&pch->upl);
2935 }
2936 return unit;
2937}
2938
2939/*
2940 * Return the PPP device interface name of a channel.
2941 */
2942char *ppp_dev_name(struct ppp_channel *chan)
2943{
2944 struct channel *pch = chan->ppp;
2945 char *name = NULL;
2946
2947 if (pch) {
2948 read_lock_bh(&pch->upl);
2949 if (pch->ppp && pch->ppp->dev)
2950 name = pch->ppp->dev->name;
2951 read_unlock_bh(&pch->upl);
2952 }
2953 return name;
2954}
2955
2956
2957/*
2958 * Disconnect a channel from the generic layer.
2959 * This must be called in process context.
2960 */
2961void
2962ppp_unregister_channel(struct ppp_channel *chan)
2963{
2964 struct channel *pch = chan->ppp;
2965 struct ppp_net *pn;
2966
2967 if (!pch)
2968 return; /* should never happen */
2969
2970 chan->ppp = NULL;
2971
2972 /*
2973 * This ensures that we have returned from any calls into
2974 * the channel's start_xmit or ioctl routine before we proceed.
2975 */
2976 down_write(&pch->chan_sem);
2977 spin_lock_bh(&pch->downl);
2978 pch->chan = NULL;
2979 spin_unlock_bh(&pch->downl);
2980 up_write(&pch->chan_sem);
2981 ppp_disconnect_channel(pch);
2982
2983 pn = ppp_pernet(pch->chan_net);
2984 spin_lock_bh(&pn->all_channels_lock);
2985 list_del(&pch->list);
2986 spin_unlock_bh(&pn->all_channels_lock);
2987
2988 ppp_unbridge_channels(pch);
2989
2990 pch->file.dead = 1;
2991 wake_up_interruptible(&pch->file.rwait);
2992
2993 if (refcount_dec_and_test(&pch->file.refcnt))
2994 ppp_destroy_channel(pch);
2995}
2996
2997/*
2998 * Callback from a channel when it can accept more to transmit.
2999 * This should be called at BH/softirq level, not interrupt level.
3000 */
3001void
3002ppp_output_wakeup(struct ppp_channel *chan)
3003{
3004 struct channel *pch = chan->ppp;
3005
3006 if (!pch)
3007 return;
3008 ppp_channel_push(pch);
3009}
3010
3011/*
3012 * Compression control.
3013 */
3014
3015/* Process the PPPIOCSCOMPRESS ioctl. */
3016static int
3017ppp_set_compress(struct ppp *ppp, struct ppp_option_data *data)
3018{
3019 int err = -EFAULT;
3020 struct compressor *cp, *ocomp;
3021 void *state, *ostate;
3022 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
3023
3024 if (data->length > CCP_MAX_OPTION_LENGTH)
3025 goto out;
3026 if (copy_from_user(ccp_option, data->ptr, data->length))
3027 goto out;
3028
3029 err = -EINVAL;
3030 if (data->length < 2 || ccp_option[1] < 2 || ccp_option[1] > data->length)
3031 goto out;
3032
3033 cp = try_then_request_module(
3034 find_compressor(ccp_option[0]),
3035 "ppp-compress-%d", ccp_option[0]);
3036 if (!cp)
3037 goto out;
3038
3039 err = -ENOBUFS;
3040 if (data->transmit) {
3041 state = cp->comp_alloc(ccp_option, data->length);
3042 if (state) {
3043 ppp_xmit_lock(ppp);
3044 ppp->xstate &= ~SC_COMP_RUN;
3045 ocomp = ppp->xcomp;
3046 ostate = ppp->xc_state;
3047 ppp->xcomp = cp;
3048 ppp->xc_state = state;
3049 ppp_xmit_unlock(ppp);
3050 if (ostate) {
3051 ocomp->comp_free(ostate);
3052 module_put(ocomp->owner);
3053 }
3054 err = 0;
3055 } else
3056 module_put(cp->owner);
3057
3058 } else {
3059 state = cp->decomp_alloc(ccp_option, data->length);
3060 if (state) {
3061 ppp_recv_lock(ppp);
3062 ppp->rstate &= ~SC_DECOMP_RUN;
3063 ocomp = ppp->rcomp;
3064 ostate = ppp->rc_state;
3065 ppp->rcomp = cp;
3066 ppp->rc_state = state;
3067 ppp_recv_unlock(ppp);
3068 if (ostate) {
3069 ocomp->decomp_free(ostate);
3070 module_put(ocomp->owner);
3071 }
3072 err = 0;
3073 } else
3074 module_put(cp->owner);
3075 }
3076
3077 out:
3078 return err;
3079}
3080
3081/*
3082 * Look at a CCP packet and update our state accordingly.
3083 * We assume the caller has the xmit or recv path locked.
3084 */
3085static void
3086ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
3087{
3088 unsigned char *dp;
3089 int len;
3090
3091 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
3092 return; /* no header */
3093 dp = skb->data + 2;
3094
3095 switch (CCP_CODE(dp)) {
3096 case CCP_CONFREQ:
3097
3098 /* A ConfReq starts negotiation of compression
3099 * in one direction of transmission,
3100 * and hence brings it down...but which way?
3101 *
3102 * Remember:
3103 * A ConfReq indicates what the sender would like to receive
3104 */
3105 if(inbound)
3106 /* He is proposing what I should send */
3107 ppp->xstate &= ~SC_COMP_RUN;
3108 else
3109 /* I am proposing to what he should send */
3110 ppp->rstate &= ~SC_DECOMP_RUN;
3111
3112 break;
3113
3114 case CCP_TERMREQ:
3115 case CCP_TERMACK:
3116 /*
3117 * CCP is going down, both directions of transmission
3118 */
3119 ppp->rstate &= ~SC_DECOMP_RUN;
3120 ppp->xstate &= ~SC_COMP_RUN;
3121 break;
3122
3123 case CCP_CONFACK:
3124 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
3125 break;
3126 len = CCP_LENGTH(dp);
3127 if (!pskb_may_pull(skb, len + 2))
3128 return; /* too short */
3129 dp += CCP_HDRLEN;
3130 len -= CCP_HDRLEN;
3131 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
3132 break;
3133 if (inbound) {
3134 /* we will start receiving compressed packets */
3135 if (!ppp->rc_state)
3136 break;
3137 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
3138 ppp->file.index, 0, ppp->mru, ppp->debug)) {
3139 ppp->rstate |= SC_DECOMP_RUN;
3140 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
3141 }
3142 } else {
3143 /* we will soon start sending compressed packets */
3144 if (!ppp->xc_state)
3145 break;
3146 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
3147 ppp->file.index, 0, ppp->debug))
3148 ppp->xstate |= SC_COMP_RUN;
3149 }
3150 break;
3151
3152 case CCP_RESETACK:
3153 /* reset the [de]compressor */
3154 if ((ppp->flags & SC_CCP_UP) == 0)
3155 break;
3156 if (inbound) {
3157 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
3158 ppp->rcomp->decomp_reset(ppp->rc_state);
3159 ppp->rstate &= ~SC_DC_ERROR;
3160 }
3161 } else {
3162 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
3163 ppp->xcomp->comp_reset(ppp->xc_state);
3164 }
3165 break;
3166 }
3167}
3168
3169/* Free up compression resources. */
3170static void
3171ppp_ccp_closed(struct ppp *ppp)
3172{
3173 void *xstate, *rstate;
3174 struct compressor *xcomp, *rcomp;
3175
3176 ppp_lock(ppp);
3177 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
3178 ppp->xstate = 0;
3179 xcomp = ppp->xcomp;
3180 xstate = ppp->xc_state;
3181 ppp->xc_state = NULL;
3182 ppp->rstate = 0;
3183 rcomp = ppp->rcomp;
3184 rstate = ppp->rc_state;
3185 ppp->rc_state = NULL;
3186 ppp_unlock(ppp);
3187
3188 if (xstate) {
3189 xcomp->comp_free(xstate);
3190 module_put(xcomp->owner);
3191 }
3192 if (rstate) {
3193 rcomp->decomp_free(rstate);
3194 module_put(rcomp->owner);
3195 }
3196}
3197
3198/* List of compressors. */
3199static LIST_HEAD(compressor_list);
3200static DEFINE_SPINLOCK(compressor_list_lock);
3201
3202struct compressor_entry {
3203 struct list_head list;
3204 struct compressor *comp;
3205};
3206
3207static struct compressor_entry *
3208find_comp_entry(int proto)
3209{
3210 struct compressor_entry *ce;
3211
3212 list_for_each_entry(ce, &compressor_list, list) {
3213 if (ce->comp->compress_proto == proto)
3214 return ce;
3215 }
3216 return NULL;
3217}
3218
3219/* Register a compressor */
3220int
3221ppp_register_compressor(struct compressor *cp)
3222{
3223 struct compressor_entry *ce;
3224 int ret;
3225 spin_lock(&compressor_list_lock);
3226 ret = -EEXIST;
3227 if (find_comp_entry(cp->compress_proto))
3228 goto out;
3229 ret = -ENOMEM;
3230 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
3231 if (!ce)
3232 goto out;
3233 ret = 0;
3234 ce->comp = cp;
3235 list_add(&ce->list, &compressor_list);
3236 out:
3237 spin_unlock(&compressor_list_lock);
3238 return ret;
3239}
3240
3241/* Unregister a compressor */
3242void
3243ppp_unregister_compressor(struct compressor *cp)
3244{
3245 struct compressor_entry *ce;
3246
3247 spin_lock(&compressor_list_lock);
3248 ce = find_comp_entry(cp->compress_proto);
3249 if (ce && ce->comp == cp) {
3250 list_del(&ce->list);
3251 kfree(ce);
3252 }
3253 spin_unlock(&compressor_list_lock);
3254}
3255
3256/* Find a compressor. */
3257static struct compressor *
3258find_compressor(int type)
3259{
3260 struct compressor_entry *ce;
3261 struct compressor *cp = NULL;
3262
3263 spin_lock(&compressor_list_lock);
3264 ce = find_comp_entry(type);
3265 if (ce) {
3266 cp = ce->comp;
3267 if (!try_module_get(cp->owner))
3268 cp = NULL;
3269 }
3270 spin_unlock(&compressor_list_lock);
3271 return cp;
3272}
3273
3274/*
3275 * Miscelleneous stuff.
3276 */
3277
3278static void
3279ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
3280{
3281 struct slcompress *vj = ppp->vj;
3282
3283 memset(st, 0, sizeof(*st));
3284 st->p.ppp_ipackets = ppp->stats64.rx_packets;
3285 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
3286 st->p.ppp_ibytes = ppp->stats64.rx_bytes;
3287 st->p.ppp_opackets = ppp->stats64.tx_packets;
3288 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
3289 st->p.ppp_obytes = ppp->stats64.tx_bytes;
3290 if (!vj)
3291 return;
3292 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
3293 st->vj.vjs_compressed = vj->sls_o_compressed;
3294 st->vj.vjs_searches = vj->sls_o_searches;
3295 st->vj.vjs_misses = vj->sls_o_misses;
3296 st->vj.vjs_errorin = vj->sls_i_error;
3297 st->vj.vjs_tossed = vj->sls_i_tossed;
3298 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
3299 st->vj.vjs_compressedin = vj->sls_i_compressed;
3300}
3301
3302/*
3303 * Stuff for handling the lists of ppp units and channels
3304 * and for initialization.
3305 */
3306
3307/*
3308 * Create a new ppp interface unit. Fails if it can't allocate memory
3309 * or if there is already a unit with the requested number.
3310 * unit == -1 means allocate a new number.
3311 */
3312static int ppp_create_interface(struct net *net, struct file *file, int *unit)
3313{
3314 struct ppp_config conf = {
3315 .file = file,
3316 .unit = *unit,
3317 .ifname_is_set = false,
3318 };
3319 struct net_device *dev;
3320 struct ppp *ppp;
3321 int err;
3322
3323 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_ENUM, ppp_setup);
3324 if (!dev) {
3325 err = -ENOMEM;
3326 goto err;
3327 }
3328 dev_net_set(dev, net);
3329 dev->rtnl_link_ops = &ppp_link_ops;
3330
3331 rtnl_lock();
3332
3333 err = ppp_dev_configure(net, dev, &conf);
3334 if (err < 0)
3335 goto err_dev;
3336 ppp = netdev_priv(dev);
3337 *unit = ppp->file.index;
3338
3339 rtnl_unlock();
3340
3341 return 0;
3342
3343err_dev:
3344 rtnl_unlock();
3345 free_netdev(dev);
3346err:
3347 return err;
3348}
3349
3350/*
3351 * Initialize a ppp_file structure.
3352 */
3353static void
3354init_ppp_file(struct ppp_file *pf, int kind)
3355{
3356 pf->kind = kind;
3357 skb_queue_head_init(&pf->xq);
3358 skb_queue_head_init(&pf->rq);
3359 refcount_set(&pf->refcnt, 1);
3360 init_waitqueue_head(&pf->rwait);
3361}
3362
3363/*
3364 * Free the memory used by a ppp unit. This is only called once
3365 * there are no channels connected to the unit and no file structs
3366 * that reference the unit.
3367 */
3368static void ppp_destroy_interface(struct ppp *ppp)
3369{
3370 atomic_dec(&ppp_unit_count);
3371
3372 if (!ppp->file.dead || ppp->n_channels) {
3373 /* "can't happen" */
3374 netdev_err(ppp->dev, "ppp: destroying ppp struct %p "
3375 "but dead=%d n_channels=%d !\n",
3376 ppp, ppp->file.dead, ppp->n_channels);
3377 return;
3378 }
3379
3380 ppp_ccp_closed(ppp);
3381 if (ppp->vj) {
3382 slhc_free(ppp->vj);
3383 ppp->vj = NULL;
3384 }
3385 skb_queue_purge(&ppp->file.xq);
3386 skb_queue_purge(&ppp->file.rq);
3387#ifdef CONFIG_PPP_MULTILINK
3388 skb_queue_purge(&ppp->mrq);
3389#endif /* CONFIG_PPP_MULTILINK */
3390#ifdef CONFIG_PPP_FILTER
3391 if (ppp->pass_filter) {
3392 bpf_prog_destroy(ppp->pass_filter);
3393 ppp->pass_filter = NULL;
3394 }
3395
3396 if (ppp->active_filter) {
3397 bpf_prog_destroy(ppp->active_filter);
3398 ppp->active_filter = NULL;
3399 }
3400#endif /* CONFIG_PPP_FILTER */
3401
3402 kfree_skb(ppp->xmit_pending);
3403 free_percpu(ppp->xmit_recursion);
3404
3405 free_netdev(ppp->dev);
3406}
3407
3408/*
3409 * Locate an existing ppp unit.
3410 * The caller should have locked the all_ppp_mutex.
3411 */
3412static struct ppp *
3413ppp_find_unit(struct ppp_net *pn, int unit)
3414{
3415 return unit_find(&pn->units_idr, unit);
3416}
3417
3418/*
3419 * Locate an existing ppp channel.
3420 * The caller should have locked the all_channels_lock.
3421 * First we look in the new_channels list, then in the
3422 * all_channels list. If found in the new_channels list,
3423 * we move it to the all_channels list. This is for speed
3424 * when we have a lot of channels in use.
3425 */
3426static struct channel *
3427ppp_find_channel(struct ppp_net *pn, int unit)
3428{
3429 struct channel *pch;
3430
3431 list_for_each_entry(pch, &pn->new_channels, list) {
3432 if (pch->file.index == unit) {
3433 list_move(&pch->list, &pn->all_channels);
3434 return pch;
3435 }
3436 }
3437
3438 list_for_each_entry(pch, &pn->all_channels, list) {
3439 if (pch->file.index == unit)
3440 return pch;
3441 }
3442
3443 return NULL;
3444}
3445
3446/*
3447 * Connect a PPP channel to a PPP interface unit.
3448 */
3449static int
3450ppp_connect_channel(struct channel *pch, int unit)
3451{
3452 struct ppp *ppp;
3453 struct ppp_net *pn;
3454 int ret = -ENXIO;
3455 int hdrlen;
3456
3457 pn = ppp_pernet(pch->chan_net);
3458
3459 mutex_lock(&pn->all_ppp_mutex);
3460 ppp = ppp_find_unit(pn, unit);
3461 if (!ppp)
3462 goto out;
3463 write_lock_bh(&pch->upl);
3464 ret = -EINVAL;
3465 if (pch->ppp ||
3466 rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl)))
3467 goto outl;
3468
3469 ppp_lock(ppp);
3470 spin_lock_bh(&pch->downl);
3471 if (!pch->chan) {
3472 /* Don't connect unregistered channels */
3473 spin_unlock_bh(&pch->downl);
3474 ppp_unlock(ppp);
3475 ret = -ENOTCONN;
3476 goto outl;
3477 }
3478 spin_unlock_bh(&pch->downl);
3479 if (pch->file.hdrlen > ppp->file.hdrlen)
3480 ppp->file.hdrlen = pch->file.hdrlen;
3481 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
3482 if (hdrlen > ppp->dev->hard_header_len)
3483 ppp->dev->hard_header_len = hdrlen;
3484 list_add_tail(&pch->clist, &ppp->channels);
3485 ++ppp->n_channels;
3486 pch->ppp = ppp;
3487 refcount_inc(&ppp->file.refcnt);
3488 ppp_unlock(ppp);
3489 ret = 0;
3490
3491 outl:
3492 write_unlock_bh(&pch->upl);
3493 out:
3494 mutex_unlock(&pn->all_ppp_mutex);
3495 return ret;
3496}
3497
3498/*
3499 * Disconnect a channel from its ppp unit.
3500 */
3501static int
3502ppp_disconnect_channel(struct channel *pch)
3503{
3504 struct ppp *ppp;
3505 int err = -EINVAL;
3506
3507 write_lock_bh(&pch->upl);
3508 ppp = pch->ppp;
3509 pch->ppp = NULL;
3510 write_unlock_bh(&pch->upl);
3511 if (ppp) {
3512 /* remove it from the ppp unit's list */
3513 ppp_lock(ppp);
3514 list_del(&pch->clist);
3515 if (--ppp->n_channels == 0)
3516 wake_up_interruptible(&ppp->file.rwait);
3517 ppp_unlock(ppp);
3518 if (refcount_dec_and_test(&ppp->file.refcnt))
3519 ppp_destroy_interface(ppp);
3520 err = 0;
3521 }
3522 return err;
3523}
3524
3525/*
3526 * Free up the resources used by a ppp channel.
3527 */
3528static void ppp_destroy_channel(struct channel *pch)
3529{
3530 put_net_track(pch->chan_net, &pch->ns_tracker);
3531 pch->chan_net = NULL;
3532
3533 atomic_dec(&channel_count);
3534
3535 if (!pch->file.dead) {
3536 /* "can't happen" */
3537 pr_err("ppp: destroying undead channel %p !\n", pch);
3538 return;
3539 }
3540 skb_queue_purge(&pch->file.xq);
3541 skb_queue_purge(&pch->file.rq);
3542 kfree(pch);
3543}
3544
3545static void __exit ppp_cleanup(void)
3546{
3547 /* should never happen */
3548 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
3549 pr_err("PPP: removing module but units remain!\n");
3550 rtnl_link_unregister(&ppp_link_ops);
3551 unregister_chrdev(PPP_MAJOR, "ppp");
3552 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
3553 class_destroy(ppp_class);
3554 unregister_pernet_device(&ppp_net_ops);
3555}
3556
3557/*
3558 * Units handling. Caller must protect concurrent access
3559 * by holding all_ppp_mutex
3560 */
3561
3562/* associate pointer with specified number */
3563static int unit_set(struct idr *p, void *ptr, int n)
3564{
3565 int unit;
3566
3567 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL);
3568 if (unit == -ENOSPC)
3569 unit = -EINVAL;
3570 return unit;
3571}
3572
3573/* get new free unit number and associate pointer with it */
3574static int unit_get(struct idr *p, void *ptr, int min)
3575{
3576 return idr_alloc(p, ptr, min, 0, GFP_KERNEL);
3577}
3578
3579/* put unit number back to a pool */
3580static void unit_put(struct idr *p, int n)
3581{
3582 idr_remove(p, n);
3583}
3584
3585/* get pointer associated with the number */
3586static void *unit_find(struct idr *p, int n)
3587{
3588 return idr_find(p, n);
3589}
3590
3591/* Module/initialization stuff */
3592
3593module_init(ppp_init);
3594module_exit(ppp_cleanup);
3595
3596EXPORT_SYMBOL(ppp_register_net_channel);
3597EXPORT_SYMBOL(ppp_register_channel);
3598EXPORT_SYMBOL(ppp_unregister_channel);
3599EXPORT_SYMBOL(ppp_channel_index);
3600EXPORT_SYMBOL(ppp_unit_number);
3601EXPORT_SYMBOL(ppp_dev_name);
3602EXPORT_SYMBOL(ppp_input);
3603EXPORT_SYMBOL(ppp_input_error);
3604EXPORT_SYMBOL(ppp_output_wakeup);
3605EXPORT_SYMBOL(ppp_register_compressor);
3606EXPORT_SYMBOL(ppp_unregister_compressor);
3607MODULE_DESCRIPTION("Generic PPP layer driver");
3608MODULE_LICENSE("GPL");
3609MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
3610MODULE_ALIAS_RTNL_LINK("ppp");
3611MODULE_ALIAS("devname:ppp");