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