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Merge tag 'irq_urgent_for_v6.5_rc1' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6-block.git] / drivers / net / ppp / ppp_generic.c
CommitLineData
2874c5fd 1// SPDX-License-Identifier: GPL-2.0-or-later
1da177e4
LT		 2/*
3 * Generic PPP layer for Linux.
4 *
5 * Copyright 1999-2002 Paul Mackerras.
6 *
1da177e4
LT		 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
1da177e4
LT		 21#include <linux/module.h>
22#include <linux/kernel.h>
174cd4b1 23#include <linux/sched/signal.h>
1da177e4
LT		 24#include <linux/kmod.h>
25#include <linux/init.h>
26#include <linux/list.h>
7a95d267 27#include <linux/idr.h>
1da177e4
LT		 28#include <linux/netdevice.h>
29#include <linux/poll.h>
30#include <linux/ppp_defs.h>
31#include <linux/filter.h>
bf7daebb 32#include <linux/ppp-ioctl.h>
1da177e4
LT		 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>
1da177e4
LT		 41#include <linux/rwsem.h>
42#include <linux/stddef.h>
43#include <linux/device.h>
8ed965d6 44#include <linux/mutex.h>
5a0e3ad6 45#include <linux/slab.h>
96d934c7 46#include <linux/file.h>
96545aeb 47#include <asm/unaligned.h>
1da177e4 48#include <net/slhc_vj.h>
60063497 49#include <linux/atomic.h>
d780cd44 50#include <linux/refcount.h>
1da177e4 51
273ec51d
CG		 52#include <linux/nsproxy.h>
53#include <net/net_namespace.h>
54#include <net/netns/generic.h>
55
1da177e4
LT		 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 */
1da177e4 71
44073187
ED		 72#define PPP_PROTO_LEN 2
73
1da177e4
LT		 74/*
75 * An instance of /dev/ppp can be associated with either a ppp
76 * interface unit or a ppp channel. In both cases, file->private_data
77 * points to one of these.
78 */
79struct ppp_file {
80 enum {
81 INTERFACE=1, CHANNEL
82 } kind;
83 struct sk_buff_head xq; /* pppd transmit queue */
84 struct sk_buff_head rq; /* receive queue for pppd */
85 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */
d780cd44 86 refcount_t refcnt; /* # refs (incl /dev/ppp attached) */
1da177e4
LT		 87 int hdrlen; /* space to leave for headers */
88 int index; /* interface unit / channel number */
89 int dead; /* unit/channel has been shut down */
90};
91
b385a144 92#define PF_TO_X(pf, X) container_of(pf, X, file)
1da177e4
LT		 93
94#define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
95#define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
96
e51f6ff3
KG		 97/*
98 * Data structure to hold primary network stats for which
99 * we want to use 64 bit storage. Other network stats
100 * are stored in dev->stats of the ppp strucute.
101 */
102struct ppp_link_stats {
103 u64 rx_packets;
104 u64 tx_packets;
105 u64 rx_bytes;
106 u64 tx_bytes;
107};
108
1da177e4
LT		 109/*
110 * Data structure describing one ppp unit.
111 * A ppp unit corresponds to a ppp network interface device
112 * and represents a multilink bundle.
113 * It can have 0 or more ppp channels connected to it.
114 */
115struct ppp {
116 struct ppp_file file; /* stuff for read/write/poll 0 */
117 struct file *owner; /* file that owns this unit 48 */
118 struct list_head channels; /* list of attached channels 4c */
119 int n_channels; /* how many channels are attached 54 */
120 spinlock_t rlock; /* lock for receive side 58 */
121 spinlock_t wlock; /* lock for transmit side 5c */
5a59a3a0 122 int __percpu *xmit_recursion; /* xmit recursion detect */
1da177e4
LT		 123 int mru; /* max receive unit 60 */
124 unsigned int flags; /* control bits 64 */
125 unsigned int xstate; /* transmit state bits 68 */
126 unsigned int rstate; /* receive state bits 6c */
127 int debug; /* debug flags 70 */
128 struct slcompress *vj; /* state for VJ header compression */
129 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
130 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
131 struct compressor *xcomp; /* transmit packet compressor 8c */
132 void *xc_state; /* its internal state 90 */
133 struct compressor *rcomp; /* receive decompressor 94 */
134 void *rc_state; /* its internal state 98 */
135 unsigned long last_xmit; /* jiffies when last pkt sent 9c */
136 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
137 struct net_device *dev; /* network interface device a4 */
739840d5 138 int closing; /* is device closing down? a8 */
1da177e4
LT		 139#ifdef CONFIG_PPP_MULTILINK
140 int nxchan; /* next channel to send something on */
141 u32 nxseq; /* next sequence number to send */
142 int mrru; /* MP: max reconst. receive unit */
143 u32 nextseq; /* MP: seq no of next packet */
144 u32 minseq; /* MP: min of most recent seqnos */
145 struct sk_buff_head mrq; /* MP: receive reconstruction queue */
146#endif /* CONFIG_PPP_MULTILINK */
1da177e4 147#ifdef CONFIG_PPP_FILTER
7ae457c1
AS		 148 struct bpf_prog *pass_filter; /* filter for packets to pass */
149 struct bpf_prog *active_filter; /* filter for pkts to reset idle */
1da177e4 150#endif /* CONFIG_PPP_FILTER */
273ec51d 151 struct net *ppp_net; /* the net we belong to */
e51f6ff3 152 struct ppp_link_stats stats64; /* 64 bit network stats */
1da177e4
LT		 153};
154
155/*
156 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
b3f9b92a
MD		 157 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
158 * SC_MUST_COMP
1da177e4
LT		 159 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
160 * Bits in xstate: SC_COMP_RUN
161 */
162#define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
163 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
b3f9b92a 164 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
1da177e4
LT		 165
166/*
167 * Private data structure for each channel.
168 * This includes the data structure used for multilink.
169 */
170struct channel {
171 struct ppp_file file; /* stuff for read/write/poll */
172 struct list_head list; /* link in all/new_channels list */
173 struct ppp_channel *chan; /* public channel data structure */
174 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
175 spinlock_t downl; /* protects `chan', file.xq dequeue */
176 struct ppp *ppp; /* ppp unit we're connected to */
273ec51d 177 struct net *chan_net; /* the net channel belongs to */
11b311a8 178 netns_tracker ns_tracker;
1da177e4 179 struct list_head clist; /* link in list of channels per unit */
4cf476ce
TP		 180 rwlock_t upl; /* protects `ppp' and 'bridge' */
181 struct channel __rcu *bridge; /* "bridged" ppp channel */
1da177e4
LT		 182#ifdef CONFIG_PPP_MULTILINK
183 u8 avail; /* flag used in multilink stuff */
184 u8 had_frag; /* >= 1 fragments have been sent */
185 u32 lastseq; /* MP: last sequence # received */
fa44a73c 186 int speed; /* speed of the corresponding ppp channel*/
1da177e4
LT		 187#endif /* CONFIG_PPP_MULTILINK */
188};
189
7d9f0b48
GN		 190struct ppp_config {
191 struct file *file;
192 s32 unit;
96d934c7 193 bool ifname_is_set;
7d9f0b48
GN		 194};
195
1da177e4
LT		 196/*
197 * SMP locking issues:
198 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
199 * list and the ppp.n_channels field, you need to take both locks
200 * before you modify them.
201 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
202 * channel.downl.
203 */
204
15fd0cd9 205static DEFINE_MUTEX(ppp_mutex);
1da177e4 206static atomic_t ppp_unit_count = ATOMIC_INIT(0);
1da177e4
LT		 207static atomic_t channel_count = ATOMIC_INIT(0);
208
273ec51d 209/* per-net private data for this module */
c7d03a00 210static unsigned int ppp_net_id __read_mostly;
273ec51d
CG		 211struct ppp_net {
212 /* units to ppp mapping */
213 struct idr units_idr;
214
215 /*
216 * all_ppp_mutex protects the units_idr mapping.
217 * It also ensures that finding a ppp unit in the units_idr
218 * map and updating its file.refcnt field is atomic.
219 */
220 struct mutex all_ppp_mutex;
221
222 /* channels */
223 struct list_head all_channels;
224 struct list_head new_channels;
225 int last_channel_index;
226
227 /*
228 * all_channels_lock protects all_channels and
229 * last_channel_index, and the atomicity of find
230 * a channel and updating its file.refcnt field.
231 */
232 spinlock_t all_channels_lock;
233};
234
1da177e4 235/* Get the PPP protocol number from a skb */
96545aeb 236#define PPP_PROTO(skb) get_unaligned_be16((skb)->data)
1da177e4
LT		 237
238/* We limit the length of ppp->file.rq to this (arbitrary) value */
239#define PPP_MAX_RQLEN 32
240
241/*
242 * Maximum number of multilink fragments queued up.
243 * This has to be large enough to cope with the maximum latency of
244 * the slowest channel relative to the others. Strictly it should
245 * depend on the number of channels and their characteristics.
246 */
247#define PPP_MP_MAX_QLEN 128
248
249/* Multilink header bits. */
250#define B 0x80 /* this fragment begins a packet */
251#define E 0x40 /* this fragment ends a packet */
252
253/* Compare multilink sequence numbers (assumed to be 32 bits wide) */
254#define seq_before(a, b) ((s32)((a) - (b)) < 0)
255#define seq_after(a, b) ((s32)((a) - (b)) > 0)
256
257/* Prototypes. */
273ec51d
CG		 258static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
259 struct file *file, unsigned int cmd, unsigned long arg);
6d066734 260static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb);
1da177e4
LT		 261static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
262static void ppp_push(struct ppp *ppp);
263static void ppp_channel_push(struct channel *pch);
264static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
265 struct channel *pch);
266static void ppp_receive_error(struct ppp *ppp);
267static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
268static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
269 struct sk_buff *skb);
270#ifdef CONFIG_PPP_MULTILINK
271static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
272 struct channel *pch);
273static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
274static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
275static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
276#endif /* CONFIG_PPP_MULTILINK */
5b6c02df 277static int ppp_set_compress(struct ppp *ppp, struct ppp_option_data *data);
1da177e4
LT		 278static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
279static void ppp_ccp_closed(struct ppp *ppp);
280static struct compressor *find_compressor(int type);
281static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
7d9f0b48 282static int ppp_create_interface(struct net *net, struct file *file, int *unit);
1da177e4 283static void init_ppp_file(struct ppp_file *pf, int kind);
1da177e4 284static void ppp_destroy_interface(struct ppp *ppp);
273ec51d
CG		 285static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit);
286static struct channel *ppp_find_channel(struct ppp_net *pn, int unit);
1da177e4
LT		 287static int ppp_connect_channel(struct channel *pch, int unit);
288static int ppp_disconnect_channel(struct channel *pch);
289static void ppp_destroy_channel(struct channel *pch);
3125f26c 290static int unit_get(struct idr *p, void *ptr, int min);
85997576 291static int unit_set(struct idr *p, void *ptr, int n);
7a95d267
CG		 292static void unit_put(struct idr *p, int n);
293static void *unit_find(struct idr *p, int n);
96d934c7 294static void ppp_setup(struct net_device *dev);
1da177e4 295
79c441ae
GN		 296static const struct net_device_ops ppp_netdev_ops;
297
56b22935 298static struct class *ppp_class;
1da177e4 299
273ec51d
CG		 300/* per net-namespace data */
301static inline struct ppp_net *ppp_pernet(struct net *net)
302{
273ec51d
CG		 303 return net_generic(net, ppp_net_id);
304}
305
1da177e4
LT		 306/* Translates a PPP protocol number to a NP index (NP == network protocol) */
307static inline int proto_to_npindex(int proto)
308{
309 switch (proto) {
310 case PPP_IP:
311 return NP_IP;
312 case PPP_IPV6:
313 return NP_IPV6;
314 case PPP_IPX:
315 return NP_IPX;
316 case PPP_AT:
317 return NP_AT;
318 case PPP_MPLS_UC:
319 return NP_MPLS_UC;
320 case PPP_MPLS_MC:
321 return NP_MPLS_MC;
322 }
323 return -EINVAL;
324}
325
326/* Translates an NP index into a PPP protocol number */
327static const int npindex_to_proto[NUM_NP] = {
328 PPP_IP,
329 PPP_IPV6,
330 PPP_IPX,
331 PPP_AT,
332 PPP_MPLS_UC,
333 PPP_MPLS_MC,
334};
6aa20a22 335
1da177e4
LT		 336/* Translates an ethertype into an NP index */
337static inline int ethertype_to_npindex(int ethertype)
338{
339 switch (ethertype) {
340 case ETH_P_IP:
341 return NP_IP;
342 case ETH_P_IPV6:
343 return NP_IPV6;
344 case ETH_P_IPX:
345 return NP_IPX;
346 case ETH_P_PPPTALK:
347 case ETH_P_ATALK:
348 return NP_AT;
349 case ETH_P_MPLS_UC:
350 return NP_MPLS_UC;
351 case ETH_P_MPLS_MC:
352 return NP_MPLS_MC;
353 }
354 return -1;
355}
356
357/* Translates an NP index into an ethertype */
358static const int npindex_to_ethertype[NUM_NP] = {
359 ETH_P_IP,
360 ETH_P_IPV6,
361 ETH_P_IPX,
362 ETH_P_PPPTALK,
363 ETH_P_MPLS_UC,
364 ETH_P_MPLS_MC,
365};
366
367/*
368 * Locking shorthand.
369 */
370#define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
371#define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
372#define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
373#define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
374#define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
375 ppp_recv_lock(ppp); } while (0)
376#define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
377 ppp_xmit_unlock(ppp); } while (0)
378
379/*
380 * /dev/ppp device routines.
381 * The /dev/ppp device is used by pppd to control the ppp unit.
382 * It supports the read, write, ioctl and poll functions.
383 * Open instances of /dev/ppp can be in one of three states:
384 * unattached, attached to a ppp unit, or attached to a ppp channel.
385 */
386static int ppp_open(struct inode *inode, struct file *file)
387{
388 /*
389 * This could (should?) be enforced by the permissions on /dev/ppp.
390 */
90e229ef 391 if (!ns_capable(file->f_cred->user_ns, CAP_NET_ADMIN))
1da177e4
LT		 392 return -EPERM;
393 return 0;
394}
395
f3ff8a4d 396static int ppp_release(struct inode *unused, struct file *file)
1da177e4
LT		 397{
398 struct ppp_file *pf = file->private_data;
399 struct ppp *ppp;
400
cd228d54 401 if (pf) {
1da177e4
LT		 402 file->private_data = NULL;
403 if (pf->kind == INTERFACE) {
404 ppp = PF_TO_PPP(pf);
8cb775bc 405 rtnl_lock();
1da177e4 406 if (file == ppp->owner)
8cb775bc
GN		 407 unregister_netdevice(ppp->dev);
408 rtnl_unlock();
1da177e4 409 }
d780cd44 410 if (refcount_dec_and_test(&pf->refcnt)) {
1da177e4
LT		 411 switch (pf->kind) {
412 case INTERFACE:
413 ppp_destroy_interface(PF_TO_PPP(pf));
414 break;
415 case CHANNEL:
416 ppp_destroy_channel(PF_TO_CHANNEL(pf));
417 break;
418 }
419 }
420 }
421 return 0;
422}
423
424static ssize_t ppp_read(struct file *file, char __user *buf,
425 size_t count, loff_t *ppos)
426{
427 struct ppp_file *pf = file->private_data;
428 DECLARE_WAITQUEUE(wait, current);
429 ssize_t ret;
430 struct sk_buff *skb = NULL;
19937d04 431 struct iovec iov;
ba568408 432 struct iov_iter to;
1da177e4
LT		 433
434 ret = count;
435
cd228d54 436 if (!pf)
1da177e4
LT		 437 return -ENXIO;
438 add_wait_queue(&pf->rwait, &wait);
439 for (;;) {
440 set_current_state(TASK_INTERRUPTIBLE);
441 skb = skb_dequeue(&pf->rq);
442 if (skb)
443 break;
444 ret = 0;
445 if (pf->dead)
446 break;
447 if (pf->kind == INTERFACE) {
448 /*
449 * Return 0 (EOF) on an interface that has no
450 * channels connected, unless it is looping
451 * network traffic (demand mode).
452 */
453 struct ppp *ppp = PF_TO_PPP(pf);
edffc217
GN		 454
455 ppp_recv_lock(ppp);
8e95a202 456 if (ppp->n_channels == 0 &&
edffc217
GN		 457 (ppp->flags & SC_LOOP_TRAFFIC) == 0) {
458 ppp_recv_unlock(ppp);
1da177e4 459 break;
edffc217
GN		 460 }
461 ppp_recv_unlock(ppp);
1da177e4
LT		 462 }
463 ret = -EAGAIN;
464 if (file->f_flags & O_NONBLOCK)
465 break;
466 ret = -ERESTARTSYS;
467 if (signal_pending(current))
468 break;
469 schedule();
470 }
471 set_current_state(TASK_RUNNING);
472 remove_wait_queue(&pf->rwait, &wait);
473
cd228d54 474 if (!skb)
1da177e4
LT		 475 goto out;
476
477 ret = -EOVERFLOW;
478 if (skb->len > count)
479 goto outf;
480 ret = -EFAULT;
19937d04
SA		 481 iov.iov_base = buf;
482 iov.iov_len = count;
de4eda9d 483 iov_iter_init(&to, ITER_DEST, &iov, 1, count);
ba568408 484 if (skb_copy_datagram_iter(skb, 0, &to, skb->len))
1da177e4
LT		 485 goto outf;
486 ret = skb->len;
487
488 outf:
489 kfree_skb(skb);
490 out:
491 return ret;
492}
493
494static ssize_t ppp_write(struct file *file, const char __user *buf,
495 size_t count, loff_t *ppos)
496{
497 struct ppp_file *pf = file->private_data;
498 struct sk_buff *skb;
499 ssize_t ret;
500
cd228d54 501 if (!pf)
1da177e4 502 return -ENXIO;
44073187
ED		 503 /* All PPP packets should start with the 2-byte protocol */
504 if (count < PPP_PROTO_LEN)
505 return -EINVAL;
1da177e4
LT		 506 ret = -ENOMEM;
507 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
cd228d54 508 if (!skb)
1da177e4
LT		 509 goto out;
510 skb_reserve(skb, pf->hdrlen);
511 ret = -EFAULT;
512 if (copy_from_user(skb_put(skb, count), buf, count)) {
513 kfree_skb(skb);
514 goto out;
515 }
516
1da177e4
LT		 517 switch (pf->kind) {
518 case INTERFACE:
6d066734 519 ppp_xmit_process(PF_TO_PPP(pf), skb);
1da177e4
LT		 520 break;
521 case CHANNEL:
6d066734 522 skb_queue_tail(&pf->xq, skb);
1da177e4
LT		 523 ppp_channel_push(PF_TO_CHANNEL(pf));
524 break;
525 }
526
527 ret = count;
528
529 out:
530 return ret;
531}
532
533/* No kernel lock - fine */
afc9a42b 534static __poll_t ppp_poll(struct file *file, poll_table *wait)
1da177e4
LT		 535{
536 struct ppp_file *pf = file->private_data;
afc9a42b 537 __poll_t mask;
1da177e4 538
cd228d54 539 if (!pf)
1da177e4
LT		 540 return 0;
541 poll_wait(file, &pf->rwait, wait);
a9a08845 542 mask = EPOLLOUT | EPOLLWRNORM;
cd228d54 543 if (skb_peek(&pf->rq))
a9a08845 544 mask |= EPOLLIN | EPOLLRDNORM;
1da177e4 545 if (pf->dead)
a9a08845 546 mask |= EPOLLHUP;
1da177e4
LT		 547 else if (pf->kind == INTERFACE) {
548 /* see comment in ppp_read */
549 struct ppp *ppp = PF_TO_PPP(pf);
edffc217
GN		 550
551 ppp_recv_lock(ppp);
8e95a202
JP		 552 if (ppp->n_channels == 0 &&
553 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
a9a08845 554 mask |= EPOLLIN | EPOLLRDNORM;
edffc217 555 ppp_recv_unlock(ppp);
1da177e4
LT		 556 }
557
558 return mask;
559}
560
561#ifdef CONFIG_PPP_FILTER
3e859adf
AV		 562static struct bpf_prog *get_filter(struct sock_fprog *uprog)
563{
564 struct sock_fprog_kern fprog;
565 struct bpf_prog *res = NULL;
566 int err;
567
568 if (!uprog->len)
569 return NULL;
570
571 /* uprog->len is unsigned short, so no overflow here */
0033b34a
EB		 572 fprog.len = uprog->len;
573 fprog.filter = memdup_user(uprog->filter,
574 uprog->len * sizeof(struct sock_filter));
3e859adf
AV		 575 if (IS_ERR(fprog.filter))
576 return ERR_CAST(fprog.filter);
577
578 err = bpf_prog_create(&res, &fprog);
579 kfree(fprog.filter);
580
581 return err ? ERR_PTR(err) : res;
582}
583
584static struct bpf_prog *ppp_get_filter(struct sock_fprog __user *p)
1da177e4
LT		 585{
586 struct sock_fprog uprog;
1da177e4 587
3e859adf
AV		 588 if (copy_from_user(&uprog, p, sizeof(struct sock_fprog)))
589 return ERR_PTR(-EFAULT);
590 return get_filter(&uprog);
591}
1da177e4 592
3e859adf
AV		 593#ifdef CONFIG_COMPAT
594struct sock_fprog32 {
595 unsigned short len;
596 compat_caddr_t filter;
597};
1da177e4 598
3e859adf
AV		 599#define PPPIOCSPASS32 _IOW('t', 71, struct sock_fprog32)
600#define PPPIOCSACTIVE32 _IOW('t', 70, struct sock_fprog32)
1da177e4 601
3e859adf
AV		 602static struct bpf_prog *compat_ppp_get_filter(struct sock_fprog32 __user *p)
603{
604 struct sock_fprog32 uprog32;
605 struct sock_fprog uprog;
1da177e4 606
3e859adf
AV		 607 if (copy_from_user(&uprog32, p, sizeof(struct sock_fprog32)))
608 return ERR_PTR(-EFAULT);
609 uprog.len = uprog32.len;
610 uprog.filter = compat_ptr(uprog32.filter);
611 return get_filter(&uprog);
1da177e4 612}
3e859adf
AV		 613#endif
614#endif
1da177e4 615
4cf476ce
TP		 616/* Bridge one PPP channel to another.
617 * When two channels are bridged, ppp_input on one channel is redirected to
618 * the other's ops->start_xmit handler.
619 * In order to safely bridge channels we must reject channels which are already
620 * part of a bridge instance, or which form part of an existing unit.
621 * Once successfully bridged, each channel holds a reference on the other
622 * to prevent it being freed while the bridge is extant.
623 */
624static int ppp_bridge_channels(struct channel *pch, struct channel *pchb)
625{
626 write_lock_bh(&pch->upl);
627 if (pch->ppp ||
628 rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl))) {
629 write_unlock_bh(&pch->upl);
630 return -EALREADY;
631 }
c1787ffd 632 refcount_inc(&pchb->file.refcnt);
4cf476ce
TP		 633 rcu_assign_pointer(pch->bridge, pchb);
634 write_unlock_bh(&pch->upl);
635
636 write_lock_bh(&pchb->upl);
637 if (pchb->ppp ||
638 rcu_dereference_protected(pchb->bridge, lockdep_is_held(&pchb->upl))) {
639 write_unlock_bh(&pchb->upl);
640 goto err_unset;
641 }
c1787ffd 642 refcount_inc(&pch->file.refcnt);
4cf476ce
TP		 643 rcu_assign_pointer(pchb->bridge, pch);
644 write_unlock_bh(&pchb->upl);
645
4cf476ce
TP		 646 return 0;
647
648err_unset:
649 write_lock_bh(&pch->upl);
c1787ffd
TP		 650 /* Re-read pch->bridge with upl held in case it was modified concurrently */
651 pchb = rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl));
4cf476ce
TP		 652 RCU_INIT_POINTER(pch->bridge, NULL);
653 write_unlock_bh(&pch->upl);
654 synchronize_rcu();
c1787ffd
TP		 655
656 if (pchb)
657 if (refcount_dec_and_test(&pchb->file.refcnt))
658 ppp_destroy_channel(pchb);
659
4cf476ce
TP		 660 return -EALREADY;
661}
662
663static int ppp_unbridge_channels(struct channel *pch)
664{
665 struct channel *pchb, *pchbb;
666
667 write_lock_bh(&pch->upl);
668 pchb = rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl));
669 if (!pchb) {
670 write_unlock_bh(&pch->upl);
671 return -EINVAL;
672 }
673 RCU_INIT_POINTER(pch->bridge, NULL);
674 write_unlock_bh(&pch->upl);
675
676 /* Only modify pchb if phcb->bridge points back to pch.
677 * If not, it implies that there has been a race unbridging (and possibly
678 * even rebridging) pchb. We should leave pchb alone to avoid either a
679 * refcount underflow, or breaking another established bridge instance.
680 */
681 write_lock_bh(&pchb->upl);
682 pchbb = rcu_dereference_protected(pchb->bridge, lockdep_is_held(&pchb->upl));
683 if (pchbb == pch)
684 RCU_INIT_POINTER(pchb->bridge, NULL);
685 write_unlock_bh(&pchb->upl);
686
687 synchronize_rcu();
688
689 if (pchbb == pch)
690 if (refcount_dec_and_test(&pch->file.refcnt))
691 ppp_destroy_channel(pch);
692
693 if (refcount_dec_and_test(&pchb->file.refcnt))
694 ppp_destroy_channel(pchb);
695
696 return 0;
697}
698
f3ff8a4d 699static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1da177e4 700{
e8e56ffd 701 struct ppp_file *pf;
1da177e4
LT		 702 struct ppp *ppp;
703 int err = -EFAULT, val, val2, i;
17c7e7f4
AB		 704 struct ppp_idle32 idle32;
705 struct ppp_idle64 idle64;
1da177e4
LT		 706 struct npioctl npi;
707 int unit, cflags;
708 struct slcompress *vj;
709 void __user *argp = (void __user *)arg;
710 int __user *p = argp;
711
e8e56ffd
GN		 712 mutex_lock(&ppp_mutex);
713
714 pf = file->private_data;
715 if (!pf) {
716 err = ppp_unattached_ioctl(current->nsproxy->net_ns,
717 pf, file, cmd, arg);
718 goto out;
719 }
1da177e4
LT		 720
721 if (cmd == PPPIOCDETACH) {
722 /*
af8d3c7c
EB		 723 * PPPIOCDETACH is no longer supported as it was heavily broken,
724 * and is only known to have been used by pppd older than
725 * ppp-2.4.2 (released November 2003).
1da177e4 726 */
af8d3c7c
EB		 727 pr_warn_once("%s (%d) used obsolete PPPIOCDETACH ioctl\n",
728 current->comm, current->pid);
1da177e4 729 err = -EINVAL;
e8e56ffd 730 goto out;
1da177e4
LT		 731 }
732
733 if (pf->kind == CHANNEL) {
4cf476ce 734 struct channel *pch, *pchb;
1da177e4 735 struct ppp_channel *chan;
4cf476ce 736 struct ppp_net *pn;
1da177e4 737
f3ff8a4d
AC		 738 pch = PF_TO_CHANNEL(pf);
739
1da177e4
LT		 740 switch (cmd) {
741 case PPPIOCCONNECT:
742 if (get_user(unit, p))
743 break;
744 err = ppp_connect_channel(pch, unit);
745 break;
746
747 case PPPIOCDISCONN:
748 err = ppp_disconnect_channel(pch);
749 break;
750
4cf476ce
TP		 751 case PPPIOCBRIDGECHAN:
752 if (get_user(unit, p))
753 break;
754 err = -ENXIO;
755 pn = ppp_pernet(current->nsproxy->net_ns);
756 spin_lock_bh(&pn->all_channels_lock);
757 pchb = ppp_find_channel(pn, unit);
758 /* Hold a reference to prevent pchb being freed while
759 * we establish the bridge.
760 */
761 if (pchb)
762 refcount_inc(&pchb->file.refcnt);
763 spin_unlock_bh(&pn->all_channels_lock);
764 if (!pchb)
765 break;
766 err = ppp_bridge_channels(pch, pchb);
767 /* Drop earlier refcount now bridge establishment is complete */
768 if (refcount_dec_and_test(&pchb->file.refcnt))
769 ppp_destroy_channel(pchb);
770 break;
771
772 case PPPIOCUNBRIDGECHAN:
773 err = ppp_unbridge_channels(pch);
774 break;
775
1da177e4
LT		 776 default:
777 down_read(&pch->chan_sem);
778 chan = pch->chan;
779 err = -ENOTTY;
780 if (chan && chan->ops->ioctl)
781 err = chan->ops->ioctl(chan, cmd, arg);
782 up_read(&pch->chan_sem);
783 }
e8e56ffd 784 goto out;
1da177e4
LT		 785 }
786
787 if (pf->kind != INTERFACE) {
788 /* can't happen */
b48f8c23 789 pr_err("PPP: not interface or channel??\n");
e8e56ffd
GN		 790 err = -EINVAL;
791 goto out;
1da177e4
LT		 792 }
793
794 ppp = PF_TO_PPP(pf);
795 switch (cmd) {
796 case PPPIOCSMRU:
797 if (get_user(val, p))
798 break;
799 ppp->mru = val;
800 err = 0;
801 break;
802
803 case PPPIOCSFLAGS:
804 if (get_user(val, p))
805 break;
806 ppp_lock(ppp);
807 cflags = ppp->flags & ~val;
a9f559c3 808#ifdef CONFIG_PPP_MULTILINK
d762d038
CS		 809 if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK))
810 ppp->nextseq = 0;
a9f559c3 811#endif
1da177e4
LT		 812 ppp->flags = val & SC_FLAG_BITS;
813 ppp_unlock(ppp);
814 if (cflags & SC_CCP_OPEN)
815 ppp_ccp_closed(ppp);
816 err = 0;
817 break;
818
819 case PPPIOCGFLAGS:
820 val = ppp->flags | ppp->xstate | ppp->rstate;
821 if (put_user(val, p))
822 break;
823 err = 0;
824 break;
825
826 case PPPIOCSCOMPRESS:
5b6c02df
AV		 827 {
828 struct ppp_option_data data;
829 if (copy_from_user(&data, argp, sizeof(data)))
830 err = -EFAULT;
831 else
832 err = ppp_set_compress(ppp, &data);
1da177e4 833 break;
5b6c02df 834 }
1da177e4
LT		 835 case PPPIOCGUNIT:
836 if (put_user(ppp->file.index, p))
837 break;
838 err = 0;
839 break;
840
841 case PPPIOCSDEBUG:
842 if (get_user(val, p))
843 break;
844 ppp->debug = val;
845 err = 0;
846 break;
847
848 case PPPIOCGDEBUG:
849 if (put_user(ppp->debug, p))
850 break;
851 err = 0;
852 break;
853
17c7e7f4
AB		 854 case PPPIOCGIDLE32:
855 idle32.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
856 idle32.recv_idle = (jiffies - ppp->last_recv) / HZ;
857 if (copy_to_user(argp, &idle32, sizeof(idle32)))
858 break;
859 err = 0;
860 break;
861
862 case PPPIOCGIDLE64:
863 idle64.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
864 idle64.recv_idle = (jiffies - ppp->last_recv) / HZ;
865 if (copy_to_user(argp, &idle64, sizeof(idle64)))
1da177e4
LT		 866 break;
867 err = 0;
868 break;
869
870 case PPPIOCSMAXCID:
871 if (get_user(val, p))
872 break;
873 val2 = 15;
874 if ((val >> 16) != 0) {
875 val2 = val >> 16;
876 val &= 0xffff;
877 }
878 vj = slhc_init(val2+1, val+1);
4ab42d78
BH		 879 if (IS_ERR(vj)) {
880 err = PTR_ERR(vj);
1da177e4
LT		 881 break;
882 }
883 ppp_lock(ppp);
cd228d54 884 if (ppp->vj)
1da177e4
LT		 885 slhc_free(ppp->vj);
886 ppp->vj = vj;
887 ppp_unlock(ppp);
888 err = 0;
889 break;
890
891 case PPPIOCGNPMODE:
892 case PPPIOCSNPMODE:
893 if (copy_from_user(&npi, argp, sizeof(npi)))
894 break;
895 err = proto_to_npindex(npi.protocol);
896 if (err < 0)
897 break;
898 i = err;
899 if (cmd == PPPIOCGNPMODE) {
900 err = -EFAULT;
901 npi.mode = ppp->npmode[i];
902 if (copy_to_user(argp, &npi, sizeof(npi)))
903 break;
904 } else {
905 ppp->npmode[i] = npi.mode;
906 /* we may be able to transmit more packets now (??) */
907 netif_wake_queue(ppp->dev);
908 }
909 err = 0;
910 break;
911
912#ifdef CONFIG_PPP_FILTER
913 case PPPIOCSPASS:
1da177e4
LT		 914 case PPPIOCSACTIVE:
915 {
3e859adf
AV		 916 struct bpf_prog *filter = ppp_get_filter(argp);
917 struct bpf_prog **which;
568f194e 918
3e859adf
AV		 919 if (IS_ERR(filter)) {
920 err = PTR_ERR(filter);
921 break;
1da177e4 922 }
3e859adf
AV		 923 if (cmd == PPPIOCSPASS)
924 which = &ppp->pass_filter;
925 else
926 which = &ppp->active_filter;
927 ppp_lock(ppp);
928 if (*which)
929 bpf_prog_destroy(*which);
930 *which = filter;
931 ppp_unlock(ppp);
932 err = 0;
1da177e4
LT		 933 break;
934 }
935#endif /* CONFIG_PPP_FILTER */
936
937#ifdef CONFIG_PPP_MULTILINK
938 case PPPIOCSMRRU:
939 if (get_user(val, p))
940 break;
941 ppp_recv_lock(ppp);
942 ppp->mrru = val;
943 ppp_recv_unlock(ppp);
944 err = 0;
945 break;
946#endif /* CONFIG_PPP_MULTILINK */
947
948 default:
949 err = -ENOTTY;
950 }
e8e56ffd
GN		 951
952out:
15fd0cd9 953 mutex_unlock(&ppp_mutex);
e8e56ffd 954
1da177e4
LT		 955 return err;
956}
957
3e859adf 958#ifdef CONFIG_COMPAT
5b6c02df
AV		 959struct ppp_option_data32 {
960 compat_uptr_t ptr;
961 u32 length;
962 compat_int_t transmit;
963};
964#define PPPIOCSCOMPRESS32 _IOW('t', 77, struct ppp_option_data32)
965
3e859adf
AV		 966static long ppp_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
967{
968 struct ppp_file *pf;
969 int err = -ENOIOCTLCMD;
970 void __user *argp = (void __user *)arg;
971
972 mutex_lock(&ppp_mutex);
973
974 pf = file->private_data;
975 if (pf && pf->kind == INTERFACE) {
976 struct ppp *ppp = PF_TO_PPP(pf);
977 switch (cmd) {
978#ifdef CONFIG_PPP_FILTER
979 case PPPIOCSPASS32:
980 case PPPIOCSACTIVE32:
981 {
982 struct bpf_prog *filter = compat_ppp_get_filter(argp);
983 struct bpf_prog **which;
984
985 if (IS_ERR(filter)) {
986 err = PTR_ERR(filter);
987 break;
988 }
989 if (cmd == PPPIOCSPASS32)
990 which = &ppp->pass_filter;
991 else
992 which = &ppp->active_filter;
993 ppp_lock(ppp);
994 if (*which)
995 bpf_prog_destroy(*which);
996 *which = filter;
997 ppp_unlock(ppp);
998 err = 0;
999 break;
1000 }
1001#endif /* CONFIG_PPP_FILTER */
5b6c02df
AV		 1002 case PPPIOCSCOMPRESS32:
1003 {
1004 struct ppp_option_data32 data32;
1005 if (copy_from_user(&data32, argp, sizeof(data32))) {
1006 err = -EFAULT;
1007 } else {
1008 struct ppp_option_data data = {
1009 .ptr = compat_ptr(data32.ptr),
1010 .length = data32.length,
1011 .transmit = data32.transmit
1012 };
1013 err = ppp_set_compress(ppp, &data);
1014 }
1015 break;
1016 }
3e859adf
AV		 1017 }
1018 }
1019 mutex_unlock(&ppp_mutex);
1020
8f5d9f2c
AB		 1021 /* all other commands have compatible arguments */
1022 if (err == -ENOIOCTLCMD)
1023 err = ppp_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
1024
3e859adf
AV		 1025 return err;
1026}
1027#endif
1028
273ec51d
CG		 1029static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
1030 struct file *file, unsigned int cmd, unsigned long arg)
1da177e4
LT		 1031{
1032 int unit, err = -EFAULT;
1033 struct ppp *ppp;
1034 struct channel *chan;
273ec51d 1035 struct ppp_net *pn;
1da177e4
LT		 1036 int __user *p = (int __user *)arg;
1037
1038 switch (cmd) {
1039 case PPPIOCNEWUNIT:
1040 /* Create a new ppp unit */
1041 if (get_user(unit, p))
1042 break;
7d9f0b48
GN		 1043 err = ppp_create_interface(net, file, &unit);
1044 if (err < 0)
1da177e4 1045 break;
7d9f0b48 1046
1da177e4 1047 err = -EFAULT;
7d9f0b48 1048 if (put_user(unit, p))
1da177e4
LT		 1049 break;
1050 err = 0;
1051 break;
1052
1053 case PPPIOCATTACH:
1054 /* Attach to an existing ppp unit */
1055 if (get_user(unit, p))
1056 break;
1da177e4 1057 err = -ENXIO;
273ec51d
CG		 1058 pn = ppp_pernet(net);
1059 mutex_lock(&pn->all_ppp_mutex);
1060 ppp = ppp_find_unit(pn, unit);
cd228d54 1061 if (ppp) {
d780cd44 1062 refcount_inc(&ppp->file.refcnt);
1da177e4
LT		 1063 file->private_data = &ppp->file;
1064 err = 0;
1065 }
273ec51d 1066 mutex_unlock(&pn->all_ppp_mutex);
1da177e4
LT		 1067 break;
1068
1069 case PPPIOCATTCHAN:
1070 if (get_user(unit, p))
1071 break;
1da177e4 1072 err = -ENXIO;
273ec51d
CG		 1073 pn = ppp_pernet(net);
1074 spin_lock_bh(&pn->all_channels_lock);
1075 chan = ppp_find_channel(pn, unit);
cd228d54 1076 if (chan) {
d780cd44 1077 refcount_inc(&chan->file.refcnt);
1da177e4
LT		 1078 file->private_data = &chan->file;
1079 err = 0;
1080 }
273ec51d 1081 spin_unlock_bh(&pn->all_channels_lock);
1da177e4
LT		 1082 break;
1083
1084 default:
1085 err = -ENOTTY;
1086 }
e8e56ffd 1087
1da177e4
LT		 1088 return err;
1089}
1090
d54b1fdb 1091static const struct file_operations ppp_device_fops = {
1da177e4
LT		 1092 .owner = THIS_MODULE,
1093 .read = ppp_read,
1094 .write = ppp_write,
1095 .poll = ppp_poll,
f3ff8a4d 1096 .unlocked_ioctl = ppp_ioctl,
3e859adf
AV		 1097#ifdef CONFIG_COMPAT
1098 .compat_ioctl = ppp_compat_ioctl,
1099#endif
1da177e4 1100 .open = ppp_open,
6038f373
AB		 1101 .release = ppp_release,
1102 .llseek = noop_llseek,
1da177e4
LT		 1103};
1104
273ec51d
CG		 1105static __net_init int ppp_init_net(struct net *net)
1106{
741a6fa2 1107 struct ppp_net *pn = net_generic(net, ppp_net_id);
273ec51d
CG		 1108
1109 idr_init(&pn->units_idr);
1110 mutex_init(&pn->all_ppp_mutex);
1111
1112 INIT_LIST_HEAD(&pn->all_channels);
1113 INIT_LIST_HEAD(&pn->new_channels);
1114
1115 spin_lock_init(&pn->all_channels_lock);
1116
273ec51d
CG		 1117 return 0;
1118}
1119
1120static __net_exit void ppp_exit_net(struct net *net)
1121{
741a6fa2 1122 struct ppp_net *pn = net_generic(net, ppp_net_id);
79c441ae
GN		 1123 struct net_device *dev;
1124 struct net_device *aux;
8cb775bc
GN		 1125 struct ppp *ppp;
1126 LIST_HEAD(list);
1127 int id;
1128
1129 rtnl_lock();
79c441ae
GN		 1130 for_each_netdev_safe(net, dev, aux) {
1131 if (dev->netdev_ops == &ppp_netdev_ops)
1132 unregister_netdevice_queue(dev, &list);
1133 }
1134
8cb775bc 1135 idr_for_each_entry(&pn->units_idr, ppp, id)
79c441ae
GN		 1136 /* Skip devices already unregistered by previous loop */
1137 if (!net_eq(dev_net(ppp->dev), net))
1138 unregister_netdevice_queue(ppp->dev, &list);
8cb775bc
GN		 1139
1140 unregister_netdevice_many(&list);
1141 rtnl_unlock();
273ec51d 1142
f02b2320 1143 mutex_destroy(&pn->all_ppp_mutex);
273ec51d 1144 idr_destroy(&pn->units_idr);
e6675000
VA		 1145 WARN_ON_ONCE(!list_empty(&pn->all_channels));
1146 WARN_ON_ONCE(!list_empty(&pn->new_channels));
273ec51d
CG		 1147}
1148
0012985d 1149static struct pernet_operations ppp_net_ops = {
273ec51d
CG		 1150 .init = ppp_init_net,
1151 .exit = ppp_exit_net,
741a6fa2
EB		 1152 .id = &ppp_net_id,
1153 .size = sizeof(struct ppp_net),
273ec51d
CG		 1154};
1155
96d934c7 1156static int ppp_unit_register(struct ppp *ppp, int unit, bool ifname_is_set)
7d9f0b48
GN		 1157{
1158 struct ppp_net *pn = ppp_pernet(ppp->ppp_net);
1159 int ret;
1160
1161 mutex_lock(&pn->all_ppp_mutex);
1162
1163 if (unit < 0) {
3125f26c 1164 ret = unit_get(&pn->units_idr, ppp, 0);
7d9f0b48
GN		 1165 if (ret < 0)
1166 goto err;
3125f26c
PR		 1167 if (!ifname_is_set) {
1168 while (1) {
1169 snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ret);
d03eb978 1170 if (!netdev_name_in_use(ppp->ppp_net, ppp->dev->name))
3125f26c
PR		 1171 break;
1172 unit_put(&pn->units_idr, ret);
1173 ret = unit_get(&pn->units_idr, ppp, ret + 1);
1174 if (ret < 0)
1175 goto err;
1176 }
1177 }
7d9f0b48
GN		 1178 } else {
1179 /* Caller asked for a specific unit number. Fail with -EEXIST
1180 * if unavailable. For backward compatibility, return -EEXIST
1181 * too if idr allocation fails; this makes pppd retry without
1182 * requesting a specific unit number.
1183 */
1184 if (unit_find(&pn->units_idr, unit)) {
1185 ret = -EEXIST;
1186 goto err;
1187 }
1188 ret = unit_set(&pn->units_idr, ppp, unit);
1189 if (ret < 0) {
1190 /* Rewrite error for backward compatibility */
1191 ret = -EEXIST;
1192 goto err;
1193 }
1194 }
1195 ppp->file.index = ret;
1196
96d934c7
GN		 1197 if (!ifname_is_set)
1198 snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ppp->file.index);
7d9f0b48 1199
0171c418
GN		 1200 mutex_unlock(&pn->all_ppp_mutex);
1201
7d9f0b48
GN		 1202 ret = register_netdevice(ppp->dev);
1203 if (ret < 0)
1204 goto err_unit;
1205
1206 atomic_inc(&ppp_unit_count);
1207
7d9f0b48
GN		 1208 return 0;
1209
1210err_unit:
0171c418 1211 mutex_lock(&pn->all_ppp_mutex);
7d9f0b48
GN		 1212 unit_put(&pn->units_idr, ppp->file.index);
1213err:
1214 mutex_unlock(&pn->all_ppp_mutex);
1215
1216 return ret;
1217}
1218
1219static int ppp_dev_configure(struct net *src_net, struct net_device *dev,
1220 const struct ppp_config *conf)
1221{
1222 struct ppp *ppp = netdev_priv(dev);
1223 int indx;
1224 int err;
e5dadc65 1225 int cpu;
7d9f0b48
GN		 1226
1227 ppp->dev = dev;
1228 ppp->ppp_net = src_net;
1229 ppp->mru = PPP_MRU;
1230 ppp->owner = conf->file;
1231
1232 init_ppp_file(&ppp->file, INTERFACE);
1233 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
1234
1235 for (indx = 0; indx < NUM_NP; ++indx)
1236 ppp->npmode[indx] = NPMODE_PASS;
1237 INIT_LIST_HEAD(&ppp->channels);
1238 spin_lock_init(&ppp->rlock);
1239 spin_lock_init(&ppp->wlock);
e5dadc65
GF		 1240
1241 ppp->xmit_recursion = alloc_percpu(int);
1242 if (!ppp->xmit_recursion) {
1243 err = -ENOMEM;
1244 goto err1;
1245 }
1246 for_each_possible_cpu(cpu)
1247 (*per_cpu_ptr(ppp->xmit_recursion, cpu)) = 0;
1248
7d9f0b48
GN		 1249#ifdef CONFIG_PPP_MULTILINK
1250 ppp->minseq = -1;
1251 skb_queue_head_init(&ppp->mrq);
1252#endif /* CONFIG_PPP_MULTILINK */
1253#ifdef CONFIG_PPP_FILTER
1254 ppp->pass_filter = NULL;
1255 ppp->active_filter = NULL;
1256#endif /* CONFIG_PPP_FILTER */
1257
96d934c7 1258 err = ppp_unit_register(ppp, conf->unit, conf->ifname_is_set);
7d9f0b48 1259 if (err < 0)
e5dadc65 1260 goto err2;
7d9f0b48
GN		 1261
1262 conf->file->private_data = &ppp->file;
1263
1264 return 0;
e5dadc65
GF		 1265err2:
1266 free_percpu(ppp->xmit_recursion);
1267err1:
1268 return err;
7d9f0b48
GN		 1269}
1270
96d934c7
GN		 1271static const struct nla_policy ppp_nl_policy[IFLA_PPP_MAX + 1] = {
1272 [IFLA_PPP_DEV_FD] = { .type = NLA_S32 },
1273};
1274
a8b8a889
MS		 1275static int ppp_nl_validate(struct nlattr *tb[], struct nlattr *data[],
1276 struct netlink_ext_ack *extack)
96d934c7
GN		 1277{
1278 if (!data)
1279 return -EINVAL;
1280
1281 if (!data[IFLA_PPP_DEV_FD])
1282 return -EINVAL;
1283 if (nla_get_s32(data[IFLA_PPP_DEV_FD]) < 0)
1284 return -EBADF;
1285
1286 return 0;
1287}
1288
1289static int ppp_nl_newlink(struct net *src_net, struct net_device *dev,
7a3f4a18
MS		 1290 struct nlattr *tb[], struct nlattr *data[],
1291 struct netlink_ext_ack *extack)
96d934c7
GN		 1292{
1293 struct ppp_config conf = {
1294 .unit = -1,
1295 .ifname_is_set = true,
1296 };
1297 struct file *file;
1298 int err;
1299
1300 file = fget(nla_get_s32(data[IFLA_PPP_DEV_FD]));
1301 if (!file)
1302 return -EBADF;
1303
1304 /* rtnl_lock is already held here, but ppp_create_interface() locks
1305 * ppp_mutex before holding rtnl_lock. Using mutex_trylock() avoids
1306 * possible deadlock due to lock order inversion, at the cost of
1307 * pushing the problem back to userspace.
1308 */
1309 if (!mutex_trylock(&ppp_mutex)) {
1310 err = -EBUSY;
1311 goto out;
1312 }
1313
1314 if (file->f_op != &ppp_device_fops || file->private_data) {
1315 err = -EBADF;
1316 goto out_unlock;
1317 }
1318
1319 conf.file = file;
bb8082f6
GN		 1320
1321 /* Don't use device name generated by the rtnetlink layer when ifname
1322 * isn't specified. Let ppp_dev_configure() set the device name using
1323 * the PPP unit identifer as suffix (i.e. ppp<unit_id>). This allows
1324 * userspace to infer the device name using to the PPPIOCGUNIT ioctl.
1325 */
2459dcb9 1326 if (!tb[IFLA_IFNAME] || !nla_len(tb[IFLA_IFNAME]) || !*(char *)nla_data(tb[IFLA_IFNAME]))
bb8082f6
GN		 1327 conf.ifname_is_set = false;
1328
96d934c7
GN		 1329 err = ppp_dev_configure(src_net, dev, &conf);
1330
1331out_unlock:
1332 mutex_unlock(&ppp_mutex);
1333out:
1334 fput(file);
1335
1336 return err;
1337}
1338
1339static void ppp_nl_dellink(struct net_device *dev, struct list_head *head)
1340{
1341 unregister_netdevice_queue(dev, head);
1342}
1343
1344static size_t ppp_nl_get_size(const struct net_device *dev)
1345{
1346 return 0;
1347}
1348
1349static int ppp_nl_fill_info(struct sk_buff *skb, const struct net_device *dev)
1350{
1351 return 0;
1352}
1353
1354static struct net *ppp_nl_get_link_net(const struct net_device *dev)
1355{
1356 struct ppp *ppp = netdev_priv(dev);
1357
1358 return ppp->ppp_net;
1359}
1360
1361static struct rtnl_link_ops ppp_link_ops __read_mostly = {
1362 .kind = "ppp",
1363 .maxtype = IFLA_PPP_MAX,
1364 .policy = ppp_nl_policy,
1365 .priv_size = sizeof(struct ppp),
1366 .setup = ppp_setup,
1367 .validate = ppp_nl_validate,
1368 .newlink = ppp_nl_newlink,
1369 .dellink = ppp_nl_dellink,
1370 .get_size = ppp_nl_get_size,
1371 .fill_info = ppp_nl_fill_info,
1372 .get_link_net = ppp_nl_get_link_net,
1373};
1374
1da177e4
LT		 1375#define PPP_MAJOR 108
1376
1377/* Called at boot time if ppp is compiled into the kernel,
1378 or at module load time (from init_module) if compiled as a module. */
1379static int __init ppp_init(void)
1380{
1381 int err;
1382
b48f8c23 1383 pr_info("PPP generic driver version " PPP_VERSION "\n");
273ec51d 1384
741a6fa2 1385 err = register_pernet_device(&ppp_net_ops);
273ec51d 1386 if (err) {
b48f8c23 1387 pr_err("failed to register PPP pernet device (%d)\n", err);
273ec51d 1388 goto out;
1da177e4
LT		 1389 }
1390
273ec51d
CG		 1391 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
1392 if (err) {
b48f8c23 1393 pr_err("failed to register PPP device (%d)\n", err);
273ec51d
CG		 1394 goto out_net;
1395 }
1396
1aaba11d 1397 ppp_class = class_create("ppp");
273ec51d
CG		 1398 if (IS_ERR(ppp_class)) {
1399 err = PTR_ERR(ppp_class);
1400 goto out_chrdev;
1401 }
1402
96d934c7
GN		 1403 err = rtnl_link_register(&ppp_link_ops);
1404 if (err) {
1405 pr_err("failed to register rtnetlink PPP handler\n");
1406 goto out_class;
1407 }
1408
273ec51d
CG		 1409 /* not a big deal if we fail here :-) */
1410 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
1411
1412 return 0;
1da177e4 1413
96d934c7
GN		 1414out_class:
1415 class_destroy(ppp_class);
1da177e4
LT		 1416out_chrdev:
1417 unregister_chrdev(PPP_MAJOR, "ppp");
273ec51d 1418out_net:
741a6fa2 1419 unregister_pernet_device(&ppp_net_ops);
273ec51d
CG		 1420out:
1421 return err;
1da177e4
LT		 1422}
1423
1424/*
1425 * Network interface unit routines.
1426 */
424efe9c 1427static netdev_tx_t
1da177e4
LT		 1428ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
1429{
c8019bf3 1430 struct ppp *ppp = netdev_priv(dev);
1da177e4
LT		 1431 int npi, proto;
1432 unsigned char *pp;
1433
1434 npi = ethertype_to_npindex(ntohs(skb->protocol));
1435 if (npi < 0)
1436 goto outf;
1437
1438 /* Drop, accept or reject the packet */
1439 switch (ppp->npmode[npi]) {
1440 case NPMODE_PASS:
1441 break;
1442 case NPMODE_QUEUE:
1443 /* it would be nice to have a way to tell the network
1444 system to queue this one up for later. */
1445 goto outf;
1446 case NPMODE_DROP:
1447 case NPMODE_ERROR:
1448 goto outf;
1449 }
1450
1451 /* Put the 2-byte PPP protocol number on the front,
1452 making sure there is room for the address and control fields. */
7b797d5b
HX		 1453 if (skb_cow_head(skb, PPP_HDRLEN))
1454 goto outf;
1455
1da177e4
LT		 1456 pp = skb_push(skb, 2);
1457 proto = npindex_to_proto[npi];
96545aeb 1458 put_unaligned_be16(proto, pp);
1da177e4 1459
79c441ae 1460 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, dev_net(dev)));
6d066734
GN		 1461 ppp_xmit_process(ppp, skb);
1462
6ed10654 1463 return NETDEV_TX_OK;
1da177e4
LT		 1464
1465 outf:
1466 kfree_skb(skb);
6ceffd47 1467 ++dev->stats.tx_dropped;
6ed10654 1468 return NETDEV_TX_OK;
1da177e4
LT		 1469}
1470
1da177e4 1471static int
34f7cac0
AB		 1472ppp_net_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
1473 void __user *addr, int cmd)
1da177e4 1474{
c8019bf3 1475 struct ppp *ppp = netdev_priv(dev);
1da177e4 1476 int err = -EFAULT;
1da177e4
LT		 1477 struct ppp_stats stats;
1478 struct ppp_comp_stats cstats;
1479 char *vers;
1480
1481 switch (cmd) {
1482 case SIOCGPPPSTATS:
1483 ppp_get_stats(ppp, &stats);
1484 if (copy_to_user(addr, &stats, sizeof(stats)))
1485 break;
1486 err = 0;
1487 break;
1488
1489 case SIOCGPPPCSTATS:
1490 memset(&cstats, 0, sizeof(cstats));
cd228d54 1491 if (ppp->xc_state)
1da177e4 1492 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
cd228d54 1493 if (ppp->rc_state)
1da177e4
LT		 1494 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
1495 if (copy_to_user(addr, &cstats, sizeof(cstats)))
1496 break;
1497 err = 0;
1498 break;
1499
1500 case SIOCGPPPVER:
1501 vers = PPP_VERSION;
1502 if (copy_to_user(addr, vers, strlen(vers) + 1))
1503 break;
1504 err = 0;
1505 break;
1506
1507 default:
1508 err = -EINVAL;
1509 }
1510
1511 return err;
1512}
1513
bc1f4470 1514static void
e51f6ff3
KG		 1515ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64)
1516{
1517 struct ppp *ppp = netdev_priv(dev);
1518
1519 ppp_recv_lock(ppp);
1520 stats64->rx_packets = ppp->stats64.rx_packets;
1521 stats64->rx_bytes = ppp->stats64.rx_bytes;
1522 ppp_recv_unlock(ppp);
1523
1524 ppp_xmit_lock(ppp);
1525 stats64->tx_packets = ppp->stats64.tx_packets;
1526 stats64->tx_bytes = ppp->stats64.tx_bytes;
1527 ppp_xmit_unlock(ppp);
1528
1529 stats64->rx_errors = dev->stats.rx_errors;
1530 stats64->tx_errors = dev->stats.tx_errors;
1531 stats64->rx_dropped = dev->stats.rx_dropped;
1532 stats64->tx_dropped = dev->stats.tx_dropped;
1533 stats64->rx_length_errors = dev->stats.rx_length_errors;
e51f6ff3
KG		 1534}
1535
303c07db
ED		 1536static int ppp_dev_init(struct net_device *dev)
1537{
6151b8b3
GN		 1538 struct ppp *ppp;
1539
1a33e10e
CW		 1540 netdev_lockdep_set_classes(dev);
1541
6151b8b3
GN		 1542 ppp = netdev_priv(dev);
1543 /* Let the netdevice take a reference on the ppp file. This ensures
1544 * that ppp_destroy_interface() won't run before the device gets
1545 * unregistered.
1546 */
d780cd44 1547 refcount_inc(&ppp->file.refcnt);
6151b8b3 1548
303c07db
ED		 1549 return 0;
1550}
1551
8cb775bc
GN		 1552static void ppp_dev_uninit(struct net_device *dev)
1553{
1554 struct ppp *ppp = netdev_priv(dev);
1555 struct ppp_net *pn = ppp_pernet(ppp->ppp_net);
1556
1557 ppp_lock(ppp);
1558 ppp->closing = 1;
1559 ppp_unlock(ppp);
1560
1561 mutex_lock(&pn->all_ppp_mutex);
1562 unit_put(&pn->units_idr, ppp->file.index);
1563 mutex_unlock(&pn->all_ppp_mutex);
1564
1565 ppp->owner = NULL;
1566
1567 ppp->file.dead = 1;
1568 wake_up_interruptible(&ppp->file.rwait);
1569}
1570
6151b8b3
GN		 1571static void ppp_dev_priv_destructor(struct net_device *dev)
1572{
1573 struct ppp *ppp;
1574
1575 ppp = netdev_priv(dev);
d780cd44 1576 if (refcount_dec_and_test(&ppp->file.refcnt))
6151b8b3
GN		 1577 ppp_destroy_interface(ppp);
1578}
1579
f6efc675
FF		 1580static int ppp_fill_forward_path(struct net_device_path_ctx *ctx,
1581 struct net_device_path *path)
1582{
1583 struct ppp *ppp = netdev_priv(ctx->dev);
1584 struct ppp_channel *chan;
1585 struct channel *pch;
1586
1587 if (ppp->flags & SC_MULTILINK)
1588 return -EOPNOTSUPP;
1589
1590 if (list_empty(&ppp->channels))
1591 return -ENODEV;
1592
1593 pch = list_first_entry(&ppp->channels, struct channel, clist);
1594 chan = pch->chan;
1595 if (!chan->ops->fill_forward_path)
1596 return -EOPNOTSUPP;
1597
1598 return chan->ops->fill_forward_path(ctx, path, chan);
1599}
1600
52256cfc 1601static const struct net_device_ops ppp_netdev_ops = {
303c07db 1602 .ndo_init = ppp_dev_init,
8cb775bc 1603 .ndo_uninit = ppp_dev_uninit,
e51f6ff3 1604 .ndo_start_xmit = ppp_start_xmit,
34f7cac0 1605 .ndo_siocdevprivate = ppp_net_siocdevprivate,
e51f6ff3 1606 .ndo_get_stats64 = ppp_get_stats64,
f6efc675 1607 .ndo_fill_forward_path = ppp_fill_forward_path,
52256cfc
SH		 1608};
1609
94dbffe1
GN		 1610static struct device_type ppp_type = {
1611 .name = "ppp",
1612};
1613
1da177e4
LT		 1614static void ppp_setup(struct net_device *dev)
1615{
52256cfc 1616 dev->netdev_ops = &ppp_netdev_ops;
94dbffe1
GN		 1617 SET_NETDEV_DEVTYPE(dev, &ppp_type);
1618
07712770
GN		 1619 dev->features |= NETIF_F_LLTX;
1620
1da177e4 1621 dev->hard_header_len = PPP_HDRLEN;
bf7daebb 1622 dev->mtu = PPP_MRU;
1da177e4
LT		 1623 dev->addr_len = 0;
1624 dev->tx_queue_len = 3;
1625 dev->type = ARPHRD_PPP;
1626 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
6151b8b3 1627 dev->priv_destructor = ppp_dev_priv_destructor;
02875878 1628 netif_keep_dst(dev);
1da177e4
LT		 1629}
1630
1631/*
1632 * Transmit-side routines.
1633 */
1634
55454a56 1635/* Called to do any work queued up on the transmit side that can now be done */
6d066734 1636static void __ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb)
1da177e4 1637{
1da177e4 1638 ppp_xmit_lock(ppp);
739840d5 1639 if (!ppp->closing) {
1da177e4 1640 ppp_push(ppp);
6d066734
GN		 1641
1642 if (skb)
1643 skb_queue_tail(&ppp->file.xq, skb);
8e95a202
JP		 1644 while (!ppp->xmit_pending &&
1645 (skb = skb_dequeue(&ppp->file.xq)))
1da177e4
LT		 1646 ppp_send_frame(ppp, skb);
1647 /* If there's no work left to do, tell the core net
1648 code that we can accept some more. */
9a5d2bd9 1649 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1da177e4 1650 netif_wake_queue(ppp->dev);
9a5d2bd9
DW		 1651 else
1652 netif_stop_queue(ppp->dev);
4c247de5
TM		 1653 } else {
1654 kfree_skb(skb);
1da177e4
LT		 1655 }
1656 ppp_xmit_unlock(ppp);
1657}
1658
6d066734 1659static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb)
55454a56
GN		 1660{
1661 local_bh_disable();
1662
e5dadc65 1663 if (unlikely(*this_cpu_ptr(ppp->xmit_recursion)))
55454a56
GN		 1664 goto err;
1665
e5dadc65 1666 (*this_cpu_ptr(ppp->xmit_recursion))++;
6d066734 1667 __ppp_xmit_process(ppp, skb);
e5dadc65 1668 (*this_cpu_ptr(ppp->xmit_recursion))--;
55454a56
GN		 1669
1670 local_bh_enable();
1671
1672 return;
1673
1674err:
1675 local_bh_enable();
1676
6d066734
GN		 1677 kfree_skb(skb);
1678
55454a56
GN		 1679 if (net_ratelimit())
1680 netdev_err(ppp->dev, "recursion detected\n");
1681}
1682
b3f9b92a
MD		 1683static inline struct sk_buff *
1684pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1685{
1686 struct sk_buff *new_skb;
1687 int len;
1688 int new_skb_size = ppp->dev->mtu +
1689 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1690 int compressor_skb_size = ppp->dev->mtu +
1691 ppp->xcomp->comp_extra + PPP_HDRLEN;
1692 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1693 if (!new_skb) {
1694 if (net_ratelimit())
b48f8c23 1695 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n");
b3f9b92a
MD		 1696 return NULL;
1697 }
1698 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1699 skb_reserve(new_skb,
1700 ppp->dev->hard_header_len - PPP_HDRLEN);
1701
1702 /* compressor still expects A/C bytes in hdr */
1703 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1704 new_skb->data, skb->len + 2,
1705 compressor_skb_size);
1706 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
968d7018 1707 consume_skb(skb);
b3f9b92a
MD		 1708 skb = new_skb;
1709 skb_put(skb, len);
1710 skb_pull(skb, 2); /* pull off A/C bytes */
1711 } else if (len == 0) {
1712 /* didn't compress, or CCP not up yet */
968d7018 1713 consume_skb(new_skb);
b3f9b92a
MD		 1714 new_skb = skb;
1715 } else {
1716 /*
1717 * (len < 0)
1718 * MPPE requires that we do not send unencrypted
1719 * frames. The compressor will return -1 if we
1720 * should drop the frame. We cannot simply test
1721 * the compress_proto because MPPE and MPPC share
1722 * the same number.
1723 */
1724 if (net_ratelimit())
b48f8c23 1725 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n");
b3f9b92a 1726 kfree_skb(skb);
968d7018 1727 consume_skb(new_skb);
b3f9b92a
MD		 1728 new_skb = NULL;
1729 }
1730 return new_skb;
1731}
1732
1da177e4
LT		 1733/*
1734 * Compress and send a frame.
1735 * The caller should have locked the xmit path,
1736 * and xmit_pending should be 0.
1737 */
1738static void
1739ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1740{
1741 int proto = PPP_PROTO(skb);
1742 struct sk_buff *new_skb;
1743 int len;
1744 unsigned char *cp;
1745
9f225444
SF		 1746 skb->dev = ppp->dev;
1747
1da177e4
LT		 1748 if (proto < 0x8000) {
1749#ifdef CONFIG_PPP_FILTER
1750 /* check if we should pass this packet */
1751 /* the filter instructions are constructed assuming
1752 a four-byte PPP header on each packet */
d58ff351 1753 *(u8 *)skb_push(skb, 2) = 1;
8e95a202 1754 if (ppp->pass_filter &&
fb7dd8bc 1755 bpf_prog_run(ppp->pass_filter, skb) == 0) {
1da177e4 1756 if (ppp->debug & 1)
b48f8c23
DM		 1757 netdev_printk(KERN_DEBUG, ppp->dev,
1758 "PPP: outbound frame "
1759 "not passed\n");
1da177e4
LT		 1760 kfree_skb(skb);
1761 return;
1762 }
1763 /* if this packet passes the active filter, record the time */
8e95a202 1764 if (!(ppp->active_filter &&
fb7dd8bc 1765 bpf_prog_run(ppp->active_filter, skb) == 0))
1da177e4
LT		 1766 ppp->last_xmit = jiffies;
1767 skb_pull(skb, 2);
1768#else
1769 /* for data packets, record the time */
1770 ppp->last_xmit = jiffies;
1771#endif /* CONFIG_PPP_FILTER */
1772 }
1773
e51f6ff3 1774 ++ppp->stats64.tx_packets;
44073187 1775 ppp->stats64.tx_bytes += skb->len - PPP_PROTO_LEN;
1da177e4
LT		 1776
1777 switch (proto) {
1778 case PPP_IP:
cd228d54 1779 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1da177e4
LT		 1780 break;
1781 /* try to do VJ TCP header compression */
1782 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1783 GFP_ATOMIC);
cd228d54 1784 if (!new_skb) {
b48f8c23 1785 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n");
1da177e4
LT		 1786 goto drop;
1787 }
1788 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1789 cp = skb->data + 2;
1790 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1791 new_skb->data + 2, &cp,
1792 !(ppp->flags & SC_NO_TCP_CCID));
1793 if (cp == skb->data + 2) {
1794 /* didn't compress */
968d7018 1795 consume_skb(new_skb);
1da177e4
LT		 1796 } else {
1797 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1798 proto = PPP_VJC_COMP;
1799 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1800 } else {
1801 proto = PPP_VJC_UNCOMP;
1802 cp[0] = skb->data[2];
1803 }
968d7018 1804 consume_skb(skb);
1da177e4
LT		 1805 skb = new_skb;
1806 cp = skb_put(skb, len + 2);
1807 cp[0] = 0;
1808 cp[1] = proto;
1809 }
1810 break;
1811
1812 case PPP_CCP:
1813 /* peek at outbound CCP frames */
1814 ppp_ccp_peek(ppp, skb, 0);
1815 break;
1816 }
1817
1818 /* try to do packet compression */
8e95a202
JP		 1819 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state &&
1820 proto != PPP_LCP && proto != PPP_CCP) {
b3f9b92a
MD		 1821 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1822 if (net_ratelimit())
b48f8c23
DM		 1823 netdev_err(ppp->dev,
1824 "ppp: compression required but "
1825 "down - pkt dropped.\n");
1da177e4
LT		 1826 goto drop;
1827 }
b3f9b92a
MD		 1828 skb = pad_compress_skb(ppp, skb);
1829 if (!skb)
1830 goto drop;
1da177e4
LT		 1831 }
1832
1833 /*
1834 * If we are waiting for traffic (demand dialling),
1835 * queue it up for pppd to receive.
1836 */
1837 if (ppp->flags & SC_LOOP_TRAFFIC) {
1838 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1839 goto drop;
1840 skb_queue_tail(&ppp->file.rq, skb);
1841 wake_up_interruptible(&ppp->file.rwait);
1842 return;
1843 }
1844
1845 ppp->xmit_pending = skb;
1846 ppp_push(ppp);
1847 return;
1848
1849 drop:
1d2f8c95 1850 kfree_skb(skb);
8c0469cd 1851 ++ppp->dev->stats.tx_errors;
1da177e4
LT		 1852}
1853
1854/*
1855 * Try to send the frame in xmit_pending.
1856 * The caller should have the xmit path locked.
1857 */
1858static void
1859ppp_push(struct ppp *ppp)
1860{
1861 struct list_head *list;
1862 struct channel *pch;
1863 struct sk_buff *skb = ppp->xmit_pending;
1864
cd228d54 1865 if (!skb)
1da177e4
LT		 1866 return;
1867
1868 list = &ppp->channels;
1869 if (list_empty(list)) {
1870 /* nowhere to send the packet, just drop it */
1871 ppp->xmit_pending = NULL;
1872 kfree_skb(skb);
1873 return;
1874 }
1875
1876 if ((ppp->flags & SC_MULTILINK) == 0) {
1877 /* not doing multilink: send it down the first channel */
1878 list = list->next;
1879 pch = list_entry(list, struct channel, clist);
1880
97fcc193 1881 spin_lock(&pch->downl);
1da177e4
LT		 1882 if (pch->chan) {
1883 if (pch->chan->ops->start_xmit(pch->chan, skb))
1884 ppp->xmit_pending = NULL;
1885 } else {
1886 /* channel got unregistered */
1887 kfree_skb(skb);
1888 ppp->xmit_pending = NULL;
1889 }
97fcc193 1890 spin_unlock(&pch->downl);
1da177e4
LT		 1891 return;
1892 }
1893
1894#ifdef CONFIG_PPP_MULTILINK
1895 /* Multilink: fragment the packet over as many links
1896 as can take the packet at the moment. */
1897 if (!ppp_mp_explode(ppp, skb))
1898 return;
1899#endif /* CONFIG_PPP_MULTILINK */
1900
1901 ppp->xmit_pending = NULL;
1902 kfree_skb(skb);
1903}
1904
1905#ifdef CONFIG_PPP_MULTILINK
d39cd5e9 1906static bool mp_protocol_compress __read_mostly = true;
d61e4038 1907module_param(mp_protocol_compress, bool, 0644);
d39cd5e9 1908MODULE_PARM_DESC(mp_protocol_compress,
1909 "compress protocol id in multilink fragments");
1910
1da177e4
LT		 1911/*
1912 * Divide a packet to be transmitted into fragments and
1913 * send them out the individual links.
1914 */
1915static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1916{
fa44a73c
LS		 1917 int len, totlen;
1918 int i, bits, hdrlen, mtu;
1919 int flen;
1920 int navail, nfree, nzero;
1921 int nbigger;
1922 int totspeed;
1923 int totfree;
1da177e4
LT		 1924 unsigned char *p, *q;
1925 struct list_head *list;
1926 struct channel *pch;
1927 struct sk_buff *frag;
1928 struct ppp_channel *chan;
1929
9c705260 1930 totspeed = 0; /*total bitrate of the bundle*/
fa44a73c
LS		 1931 nfree = 0; /* # channels which have no packet already queued */
1932 navail = 0; /* total # of usable channels (not deregistered) */
1933 nzero = 0; /* number of channels with zero speed associated*/
1934 totfree = 0; /*total # of channels available and
9c705260
GP		 1935 *having no queued packets before
1936 *starting the fragmentation*/
1937
1da177e4 1938 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
fa44a73c
LS		 1939 i = 0;
1940 list_for_each_entry(pch, &ppp->channels, clist) {
3429769b
DC		 1941 if (pch->chan) {
1942 pch->avail = 1;
1943 navail++;
1944 pch->speed = pch->chan->speed;
1945 } else {
1946 pch->avail = 0;
1947 }
fa44a73c 1948 if (pch->avail) {
b03efcfb 1949 if (skb_queue_empty(&pch->file.xq) ||
fa44a73c 1950 !pch->had_frag) {
9c705260
GP		 1951 if (pch->speed == 0)
1952 nzero++;
1953 else
1954 totspeed += pch->speed;
1955
1956 pch->avail = 2;
1957 ++nfree;
1958 ++totfree;
1959 }
fa44a73c
LS		 1960 if (!pch->had_frag && i < ppp->nxchan)
1961 ppp->nxchan = i;
1da177e4 1962 }
516cd15f 1963 ++i;
1da177e4 1964 }
516cd15f 1965 /*
fa44a73c
LS		 1966 * Don't start sending this packet unless at least half of
1967 * the channels are free. This gives much better TCP
1968 * performance if we have a lot of channels.
516cd15f 1969 */
fa44a73c
LS		 1970 if (nfree == 0 || nfree < navail / 2)
1971 return 0; /* can't take now, leave it in xmit_pending */
1da177e4 1972
d39cd5e9 1973 /* Do protocol field compression */
fa44a73c
LS		 1974 p = skb->data;
1975 len = skb->len;
d39cd5e9 1976 if (*p == 0 && mp_protocol_compress) {
1da177e4
LT		 1977 ++p;
1978 --len;
1979 }
1980
9c705260 1981 totlen = len;
fa44a73c 1982 nbigger = len % nfree;
9c705260 1983
fa44a73c
LS		 1984 /* skip to the channel after the one we last used
1985 and start at that one */
81616c5a 1986 list = &ppp->channels;
fa44a73c 1987 for (i = 0; i < ppp->nxchan; ++i) {
1da177e4 1988 list = list->next;
fa44a73c
LS		 1989 if (list == &ppp->channels) {
1990 i = 0;
1da177e4
LT		 1991 break;
1992 }
1993 }
1994
fa44a73c 1995 /* create a fragment for each channel */
1da177e4 1996 bits = B;
fa44a73c 1997 while (len > 0) {
1da177e4 1998 list = list->next;
fa44a73c
LS		 1999 if (list == &ppp->channels) {
2000 i = 0;
1da177e4
LT		 2001 continue;
2002 }
fa44a73c 2003 pch = list_entry(list, struct channel, clist);
1da177e4
LT		 2004 ++i;
2005 if (!pch->avail)
2006 continue;
2007
516cd15f 2008 /*
fa44a73c
LS		 2009 * Skip this channel if it has a fragment pending already and
2010 * we haven't given a fragment to all of the free channels.
516cd15f
PM		 2011 */
2012 if (pch->avail == 1) {
fa44a73c 2013 if (nfree > 0)
516cd15f
PM		 2014 continue;
2015 } else {
516cd15f
PM		 2016 pch->avail = 1;
2017 }
2018
1da177e4 2019 /* check the channel's mtu and whether it is still attached. */
97fcc193 2020 spin_lock(&pch->downl);
516cd15f 2021 if (pch->chan == NULL) {
fa44a73c 2022 /* can't use this channel, it's being deregistered */
9c705260
GP		 2023 if (pch->speed == 0)
2024 nzero--;
2025 else
fa44a73c 2026 totspeed -= pch->speed;
9c705260 2027
97fcc193 2028 spin_unlock(&pch->downl);
1da177e4 2029 pch->avail = 0;
9c705260
GP		 2030 totlen = len;
2031 totfree--;
2032 nfree--;
fa44a73c 2033 if (--navail == 0)
1da177e4
LT		 2034 break;
2035 continue;
2036 }
2037
2038 /*
9c705260 2039 *if the channel speed is not set divide
fa44a73c 2040 *the packet evenly among the free channels;
9c705260
GP		 2041 *otherwise divide it according to the speed
2042 *of the channel we are going to transmit on
2043 */
886f9fe6 2044 flen = len;
a53a8b56
BM		 2045 if (nfree > 0) {
2046 if (pch->speed == 0) {
536e00e5 2047 flen = len/nfree;
a53a8b56
BM		 2048 if (nbigger > 0) {
2049 flen++;
2050 nbigger--;
2051 }
2052 } else {
2053 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
2054 ((totspeed*totfree)/pch->speed)) - hdrlen;
2055 if (nbigger > 0) {
2056 flen += ((totfree - nzero)*pch->speed)/totspeed;
2057 nbigger -= ((totfree - nzero)*pch->speed)/
9c705260 2058 totspeed;
a53a8b56 2059 }
9c705260 2060 }
a53a8b56 2061 nfree--;
9c705260 2062 }
9c705260
GP		 2063
2064 /*
fa44a73c 2065 *check if we are on the last channel or
25985edc 2066 *we exceded the length of the data to
9c705260
GP		 2067 *fragment
2068 */
a53a8b56 2069 if ((nfree <= 0) || (flen > len))
9c705260
GP		 2070 flen = len;
2071 /*
2072 *it is not worth to tx on slow channels:
2073 *in that case from the resulting flen according to the
2074 *above formula will be equal or less than zero.
2075 *Skip the channel in this case
1da177e4 2076 */
fa44a73c 2077 if (flen <= 0) {
9c705260 2078 pch->avail = 2;
97fcc193 2079 spin_unlock(&pch->downl);
9c705260
GP		 2080 continue;
2081 }
2082
22e83a29
HW		 2083 /*
2084 * hdrlen includes the 2-byte PPP protocol field, but the
2085 * MTU counts only the payload excluding the protocol field.
2086 * (RFC1661 Section 2)
2087 */
2088 mtu = pch->chan->mtu - (hdrlen - 2);
fa44a73c
LS		 2089 if (mtu < 4)
2090 mtu = 4;
516cd15f
PM		 2091 if (flen > mtu)
2092 flen = mtu;
fa44a73c
LS		 2093 if (flen == len)
2094 bits |= E;
2095 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
cd228d54 2096 if (!frag)
516cd15f 2097 goto noskb;
fa44a73c 2098 q = skb_put(frag, flen + hdrlen);
516cd15f 2099
fa44a73c 2100 /* make the MP header */
96545aeb 2101 put_unaligned_be16(PPP_MP, q);
516cd15f 2102 if (ppp->flags & SC_MP_XSHORTSEQ) {
fa44a73c 2103 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
516cd15f
PM		 2104 q[3] = ppp->nxseq;
2105 } else {
2106 q[2] = bits;
2107 q[3] = ppp->nxseq >> 16;
2108 q[4] = ppp->nxseq >> 8;
2109 q[5] = ppp->nxseq;
1da177e4 2110 }
516cd15f 2111
9c705260 2112 memcpy(q + hdrlen, p, flen);
516cd15f
PM		 2113
2114 /* try to send it down the channel */
2115 chan = pch->chan;
fa44a73c 2116 if (!skb_queue_empty(&pch->file.xq) ||
9c705260 2117 !chan->ops->start_xmit(chan, frag))
516cd15f 2118 skb_queue_tail(&pch->file.xq, frag);
fa44a73c 2119 pch->had_frag = 1;
516cd15f 2120 p += flen;
fa44a73c 2121 len -= flen;
516cd15f
PM		 2122 ++ppp->nxseq;
2123 bits = 0;
97fcc193 2124 spin_unlock(&pch->downl);
516cd15f 2125 }
fa44a73c 2126 ppp->nxchan = i;
1da177e4
LT		 2127
2128 return 1;
2129
2130 noskb:
97fcc193 2131 spin_unlock(&pch->downl);
1da177e4 2132 if (ppp->debug & 1)
b48f8c23 2133 netdev_err(ppp->dev, "PPP: no memory (fragment)\n");
8c0469cd 2134 ++ppp->dev->stats.tx_errors;
1da177e4
LT		 2135 ++ppp->nxseq;
2136 return 1; /* abandon the frame */
2137}
2138#endif /* CONFIG_PPP_MULTILINK */
2139
55454a56
GN		 2140/* Try to send data out on a channel */
2141static void __ppp_channel_push(struct channel *pch)
1da177e4
LT		 2142{
2143 struct sk_buff *skb;
2144 struct ppp *ppp;
2145
97fcc193 2146 spin_lock(&pch->downl);
cd228d54 2147 if (pch->chan) {
b03efcfb 2148 while (!skb_queue_empty(&pch->file.xq)) {
1da177e4
LT		 2149 skb = skb_dequeue(&pch->file.xq);
2150 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
2151 /* put the packet back and try again later */
2152 skb_queue_head(&pch->file.xq, skb);
2153 break;
2154 }
2155 }
2156 } else {
2157 /* channel got deregistered */
2158 skb_queue_purge(&pch->file.xq);
2159 }
97fcc193 2160 spin_unlock(&pch->downl);
1da177e4 2161 /* see if there is anything from the attached unit to be sent */
b03efcfb 2162 if (skb_queue_empty(&pch->file.xq)) {
1da177e4 2163 ppp = pch->ppp;
cd228d54 2164 if (ppp)
6d066734 2165 __ppp_xmit_process(ppp, NULL);
1da177e4
LT		 2166 }
2167}
2168
55454a56
GN		 2169static void ppp_channel_push(struct channel *pch)
2170{
0a0e1a85
GN		 2171 read_lock_bh(&pch->upl);
2172 if (pch->ppp) {
2173 (*this_cpu_ptr(pch->ppp->xmit_recursion))++;
2174 __ppp_channel_push(pch);
2175 (*this_cpu_ptr(pch->ppp->xmit_recursion))--;
2176 } else {
2177 __ppp_channel_push(pch);
2178 }
2179 read_unlock_bh(&pch->upl);
55454a56
GN		 2180}
2181
1da177e4
LT		 2182/*
2183 * Receive-side routines.
2184 */
2185
a00eac0c
DM		 2186struct ppp_mp_skb_parm {
2187 u32 sequence;
2188 u8 BEbits;
2189};
2190#define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb))
1da177e4
LT		 2191
2192static inline void
2193ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
2194{
2195 ppp_recv_lock(ppp);
739840d5 2196 if (!ppp->closing)
1da177e4
LT		 2197 ppp_receive_frame(ppp, skb, pch);
2198 else
2199 kfree_skb(skb);
2200 ppp_recv_unlock(ppp);
2201}
2202
7fb1b8ca
SP		 2203/**
2204 * __ppp_decompress_proto - Decompress protocol field, slim version.
2205 * @skb: Socket buffer where protocol field should be decompressed. It must have
2206 * at least 1 byte of head room and 1 byte of linear data. First byte of
2207 * data must be a protocol field byte.
2208 *
2209 * Decompress protocol field in PPP header if it's compressed, e.g. when
2210 * Protocol-Field-Compression (PFC) was negotiated. No checks w.r.t. skb data
2211 * length are done in this function.
2212 */
2213static void __ppp_decompress_proto(struct sk_buff *skb)
2214{
2215 if (skb->data[0] & 0x01)
2216 *(u8 *)skb_push(skb, 1) = 0x00;
2217}
2218
2219/**
2220 * ppp_decompress_proto - Check skb data room and decompress protocol field.
2221 * @skb: Socket buffer where protocol field should be decompressed. First byte
2222 * of data must be a protocol field byte.
2223 *
2224 * Decompress protocol field in PPP header if it's compressed, e.g. when
2225 * Protocol-Field-Compression (PFC) was negotiated. This function also makes
2226 * sure that skb data room is sufficient for Protocol field, before and after
2227 * decompression.
2228 *
2229 * Return: true - decompressed successfully, false - not enough room in skb.
2230 */
2231static bool ppp_decompress_proto(struct sk_buff *skb)
2232{
2233 /* At least one byte should be present (if protocol is compressed) */
2234 if (!pskb_may_pull(skb, 1))
2235 return false;
2236
2237 __ppp_decompress_proto(skb);
2238
2239 /* Protocol field should occupy 2 bytes when not compressed */
2240 return pskb_may_pull(skb, 2);
2241}
2242
4cf476ce
TP		 2243/* Attempt to handle a frame via. a bridged channel, if one exists.
2244 * If the channel is bridged, the frame is consumed by the bridge.
2245 * If not, the caller must handle the frame by normal recv mechanisms.
2246 * Returns true if the frame is consumed, false otherwise.
2247 */
2248static bool ppp_channel_bridge_input(struct channel *pch, struct sk_buff *skb)
2249{
2250 struct channel *pchb;
2251
2252 rcu_read_lock();
2253 pchb = rcu_dereference(pch->bridge);
2254 if (!pchb)
2255 goto out_rcu;
2256
2257 spin_lock(&pchb->downl);
2258 if (!pchb->chan) {
2259 /* channel got unregistered */
2260 kfree_skb(skb);
2261 goto outl;
2262 }
2263
2264 skb_scrub_packet(skb, !net_eq(pch->chan_net, pchb->chan_net));
2265 if (!pchb->chan->ops->start_xmit(pchb->chan, skb))
2266 kfree_skb(skb);
2267
2268outl:
2269 spin_unlock(&pchb->downl);
2270out_rcu:
2271 rcu_read_unlock();
2272
2273 /* If pchb is set then we've consumed the packet */
2274 return !!pchb;
2275}
2276
1da177e4
LT		 2277void
2278ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
2279{
2280 struct channel *pch = chan->ppp;
2281 int proto;
2282
ea8420e9 2283 if (!pch) {
1da177e4
LT		 2284 kfree_skb(skb);
2285 return;
2286 }
516cd15f 2287
4cf476ce
TP		 2288 /* If the channel is bridged, transmit via. bridge */
2289 if (ppp_channel_bridge_input(pch, skb))
2290 return;
2291
1da177e4 2292 read_lock_bh(&pch->upl);
7fb1b8ca 2293 if (!ppp_decompress_proto(skb)) {
ea8420e9
SA		 2294 kfree_skb(skb);
2295 if (pch->ppp) {
2296 ++pch->ppp->dev->stats.rx_length_errors;
2297 ppp_receive_error(pch->ppp);
2298 }
2299 goto done;
2300 }
2301
2302 proto = PPP_PROTO(skb);
cd228d54 2303 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1da177e4
LT		 2304 /* put it on the channel queue */
2305 skb_queue_tail(&pch->file.rq, skb);
2306 /* drop old frames if queue too long */
8e95a202
JP		 2307 while (pch->file.rq.qlen > PPP_MAX_RQLEN &&
2308 (skb = skb_dequeue(&pch->file.rq)))
1da177e4
LT		 2309 kfree_skb(skb);
2310 wake_up_interruptible(&pch->file.rwait);
2311 } else {
2312 ppp_do_recv(pch->ppp, skb, pch);
2313 }
ea8420e9
SA		 2314
2315done:
1da177e4
LT		 2316 read_unlock_bh(&pch->upl);
2317}
2318
2319/* Put a 0-length skb in the receive queue as an error indication */
2320void
2321ppp_input_error(struct ppp_channel *chan, int code)
2322{
2323 struct channel *pch = chan->ppp;
2324 struct sk_buff *skb;
2325
cd228d54 2326 if (!pch)
1da177e4
LT		 2327 return;
2328
2329 read_lock_bh(&pch->upl);
cd228d54 2330 if (pch->ppp) {
1da177e4 2331 skb = alloc_skb(0, GFP_ATOMIC);
cd228d54 2332 if (skb) {
1da177e4
LT		 2333 skb->len = 0; /* probably unnecessary */
2334 skb->cb[0] = code;
2335 ppp_do_recv(pch->ppp, skb, pch);
2336 }
2337 }
2338 read_unlock_bh(&pch->upl);
2339}
2340
2341/*
2342 * We come in here to process a received frame.
2343 * The receive side of the ppp unit is locked.
2344 */
2345static void
2346ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
2347{
ea8420e9
SA		 2348 /* note: a 0-length skb is used as an error indication */
2349 if (skb->len > 0) {
3dfb0534 2350 skb_checksum_complete_unset(skb);
1da177e4
LT		 2351#ifdef CONFIG_PPP_MULTILINK
2352 /* XXX do channel-level decompression here */
2353 if (PPP_PROTO(skb) == PPP_MP)
2354 ppp_receive_mp_frame(ppp, skb, pch);
2355 else
2356#endif /* CONFIG_PPP_MULTILINK */
2357 ppp_receive_nonmp_frame(ppp, skb);
ea8420e9
SA		 2358 } else {
2359 kfree_skb(skb);
2360 ppp_receive_error(ppp);
1da177e4 2361 }
1da177e4
LT		 2362}
2363
2364static void
2365ppp_receive_error(struct ppp *ppp)
2366{
8c0469cd 2367 ++ppp->dev->stats.rx_errors;
cd228d54 2368 if (ppp->vj)
1da177e4
LT		 2369 slhc_toss(ppp->vj);
2370}
2371
2372static void
2373ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
2374{
2375 struct sk_buff *ns;
2376 int proto, len, npi;
2377
2378 /*
2379 * Decompress the frame, if compressed.
2380 * Note that some decompressors need to see uncompressed frames
2381 * that come in as well as compressed frames.
2382 */
8e95a202
JP		 2383 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) &&
2384 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1da177e4
LT		 2385 skb = ppp_decompress_frame(ppp, skb);
2386
b3f9b92a
MD		 2387 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
2388 goto err;
2389
7fb1b8ca
SP		 2390 /* At this point the "Protocol" field MUST be decompressed, either in
2391 * ppp_input(), ppp_decompress_frame() or in ppp_receive_mp_frame().
2392 */
1da177e4
LT		 2393 proto = PPP_PROTO(skb);
2394 switch (proto) {
2395 case PPP_VJC_COMP:
2396 /* decompress VJ compressed packets */
cd228d54 2397 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1da177e4
LT		 2398 goto err;
2399
2a38b775 2400 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1da177e4
LT		 2401 /* copy to a new sk_buff with more tailroom */
2402 ns = dev_alloc_skb(skb->len + 128);
cd228d54 2403 if (!ns) {
b48f8c23
DM		 2404 netdev_err(ppp->dev, "PPP: no memory "
2405 "(VJ decomp)\n");
1da177e4
LT		 2406 goto err;
2407 }
2408 skb_reserve(ns, 2);
2409 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
968d7018 2410 consume_skb(skb);
1da177e4
LT		 2411 skb = ns;
2412 }
e3f749c4
HX		 2413 else
2414 skb->ip_summed = CHECKSUM_NONE;
1da177e4
LT		 2415
2416 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
2417 if (len <= 0) {
b48f8c23
DM		 2418 netdev_printk(KERN_DEBUG, ppp->dev,
2419 "PPP: VJ decompression error\n");
1da177e4
LT		 2420 goto err;
2421 }
2422 len += 2;
2423 if (len > skb->len)
2424 skb_put(skb, len - skb->len);
2425 else if (len < skb->len)
2426 skb_trim(skb, len);
2427 proto = PPP_IP;
2428 break;
2429
2430 case PPP_VJC_UNCOMP:
cd228d54 2431 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1da177e4 2432 goto err;
6aa20a22 2433
1da177e4
LT		 2434 /* Until we fix the decompressor need to make sure
2435 * data portion is linear.
2436 */
6aa20a22 2437 if (!pskb_may_pull(skb, skb->len))
1da177e4
LT		 2438 goto err;
2439
2440 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
b48f8c23 2441 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n");
1da177e4
LT		 2442 goto err;
2443 }
2444 proto = PPP_IP;
2445 break;
2446
2447 case PPP_CCP:
2448 ppp_ccp_peek(ppp, skb, 1);
2449 break;
2450 }
2451
e51f6ff3
KG		 2452 ++ppp->stats64.rx_packets;
2453 ppp->stats64.rx_bytes += skb->len - 2;
1da177e4
LT		 2454
2455 npi = proto_to_npindex(proto);
2456 if (npi < 0) {
2457 /* control or unknown frame - pass it to pppd */
2458 skb_queue_tail(&ppp->file.rq, skb);
2459 /* limit queue length by dropping old frames */
8e95a202
JP		 2460 while (ppp->file.rq.qlen > PPP_MAX_RQLEN &&
2461 (skb = skb_dequeue(&ppp->file.rq)))
1da177e4
LT		 2462 kfree_skb(skb);
2463 /* wake up any process polling or blocking on read */
2464 wake_up_interruptible(&ppp->file.rwait);
2465
2466 } else {
2467 /* network protocol frame - give it to the kernel */
2468
2469#ifdef CONFIG_PPP_FILTER
2470 /* check if the packet passes the pass and active filters */
2471 /* the filter instructions are constructed assuming
2472 a four-byte PPP header on each packet */
2a38b775 2473 if (ppp->pass_filter || ppp->active_filter) {
14bbd6a5 2474 if (skb_unclone(skb, GFP_ATOMIC))
2a38b775
HX		 2475 goto err;
2476
d58ff351 2477 *(u8 *)skb_push(skb, 2) = 0;
8e95a202 2478 if (ppp->pass_filter &&
fb7dd8bc 2479 bpf_prog_run(ppp->pass_filter, skb) == 0) {
2a38b775 2480 if (ppp->debug & 1)
b48f8c23
DM		 2481 netdev_printk(KERN_DEBUG, ppp->dev,
2482 "PPP: inbound frame "
2483 "not passed\n");
2a38b775
HX		 2484 kfree_skb(skb);
2485 return;
2486 }
8e95a202 2487 if (!(ppp->active_filter &&
fb7dd8bc 2488 bpf_prog_run(ppp->active_filter, skb) == 0))
2a38b775
HX		 2489 ppp->last_recv = jiffies;
2490 __skb_pull(skb, 2);
2491 } else
1da177e4 2492#endif /* CONFIG_PPP_FILTER */
2a38b775 2493 ppp->last_recv = jiffies;
1da177e4 2494
8e95a202
JP		 2495 if ((ppp->dev->flags & IFF_UP) == 0 ||
2496 ppp->npmode[npi] != NPMODE_PASS) {
1da177e4
LT		 2497 kfree_skb(skb);
2498 } else {
cbb042f9
HX		 2499 /* chop off protocol */
2500 skb_pull_rcsum(skb, 2);
1da177e4
LT		 2501 skb->dev = ppp->dev;
2502 skb->protocol = htons(npindex_to_ethertype[npi]);
459a98ed 2503 skb_reset_mac_header(skb);
79c441ae
GN		 2504 skb_scrub_packet(skb, !net_eq(ppp->ppp_net,
2505 dev_net(ppp->dev)));
1da177e4 2506 netif_rx(skb);
1da177e4
LT		 2507 }
2508 }
2509 return;
2510
2511 err:
2512 kfree_skb(skb);
2513 ppp_receive_error(ppp);
2514}
2515
2516static struct sk_buff *
2517ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
2518{
2519 int proto = PPP_PROTO(skb);
2520 struct sk_buff *ns;
2521 int len;
2522
2523 /* Until we fix all the decompressor's need to make sure
2524 * data portion is linear.
2525 */
2526 if (!pskb_may_pull(skb, skb->len))
2527 goto err;
2528
2529 if (proto == PPP_COMP) {
4b2a8fb3
KS		 2530 int obuff_size;
2531
2532 switch(ppp->rcomp->compress_proto) {
2533 case CI_MPPE:
2534 obuff_size = ppp->mru + PPP_HDRLEN + 1;
2535 break;
2536 default:
2537 obuff_size = ppp->mru + PPP_HDRLEN;
2538 break;
2539 }
2540
2541 ns = dev_alloc_skb(obuff_size);
cd228d54 2542 if (!ns) {
b48f8c23
DM		 2543 netdev_err(ppp->dev, "ppp_decompress_frame: "
2544 "no memory\n");
1da177e4
LT		 2545 goto err;
2546 }
2547 /* the decompressor still expects the A/C bytes in the hdr */
2548 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
06c7af56 2549 skb->len + 2, ns->data, obuff_size);
1da177e4
LT		 2550 if (len < 0) {
2551 /* Pass the compressed frame to pppd as an
2552 error indication. */
2553 if (len == DECOMP_FATALERROR)
2554 ppp->rstate |= SC_DC_FERROR;
2555 kfree_skb(ns);
2556 goto err;
2557 }
2558
968d7018 2559 consume_skb(skb);
1da177e4
LT		 2560 skb = ns;
2561 skb_put(skb, len);
2562 skb_pull(skb, 2); /* pull off the A/C bytes */
2563
7fb1b8ca
SP		 2564 /* Don't call __ppp_decompress_proto() here, but instead rely on
2565 * corresponding algo (mppe/bsd/deflate) to decompress it.
2566 */
1da177e4
LT		 2567 } else {
2568 /* Uncompressed frame - pass to decompressor so it
2569 can update its dictionary if necessary. */
2570 if (ppp->rcomp->incomp)
2571 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
2572 skb->len + 2);
2573 }
2574
2575 return skb;
2576
2577 err:
2578 ppp->rstate |= SC_DC_ERROR;
2579 ppp_receive_error(ppp);
2580 return skb;
2581}
2582
2583#ifdef CONFIG_PPP_MULTILINK
2584/*
2585 * Receive a multilink frame.
2586 * We put it on the reconstruction queue and then pull off
2587 * as many completed frames as we can.
2588 */
2589static void
2590ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
2591{
2592 u32 mask, seq;
81616c5a 2593 struct channel *ch;
1da177e4
LT		 2594 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
2595
2a38b775 2596 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
1da177e4
LT		 2597 goto err; /* no good, throw it away */
2598
2599 /* Decode sequence number and begin/end bits */
2600 if (ppp->flags & SC_MP_SHORTSEQ) {
2601 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
2602 mask = 0xfff;
2603 } else {
2604 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
2605 mask = 0xffffff;
2606 }
a00eac0c 2607 PPP_MP_CB(skb)->BEbits = skb->data[2];
1da177e4
LT		 2608 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
2609
2610 /*
2611 * Do protocol ID decompression on the first fragment of each packet.
7fb1b8ca
SP		 2612 * We have to do that here, because ppp_receive_nonmp_frame() expects
2613 * decompressed protocol field.
1da177e4 2614 */
7fb1b8ca
SP		 2615 if (PPP_MP_CB(skb)->BEbits & B)
2616 __ppp_decompress_proto(skb);
1da177e4
LT		 2617
2618 /*
2619 * Expand sequence number to 32 bits, making it as close
2620 * as possible to ppp->minseq.
2621 */
2622 seq |= ppp->minseq & ~mask;
2623 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
2624 seq += mask + 1;
2625 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
2626 seq -= mask + 1; /* should never happen */
a00eac0c 2627 PPP_MP_CB(skb)->sequence = seq;
1da177e4
LT		 2628 pch->lastseq = seq;
2629
2630 /*
2631 * If this packet comes before the next one we were expecting,
2632 * drop it.
2633 */
2634 if (seq_before(seq, ppp->nextseq)) {
2635 kfree_skb(skb);
8c0469cd 2636 ++ppp->dev->stats.rx_dropped;
1da177e4
LT		 2637 ppp_receive_error(ppp);
2638 return;
2639 }
2640
2641 /*
2642 * Reevaluate minseq, the minimum over all channels of the
2643 * last sequence number received on each channel. Because of
2644 * the increasing sequence number rule, we know that any fragment
2645 * before `minseq' which hasn't arrived is never going to arrive.
2646 * The list of channels can't change because we have the receive
2647 * side of the ppp unit locked.
2648 */
81616c5a 2649 list_for_each_entry(ch, &ppp->channels, clist) {
1da177e4
LT		 2650 if (seq_before(ch->lastseq, seq))
2651 seq = ch->lastseq;
2652 }
2653 if (seq_before(ppp->minseq, seq))
2654 ppp->minseq = seq;
2655
2656 /* Put the fragment on the reconstruction queue */
2657 ppp_mp_insert(ppp, skb);
2658
2659 /* If the queue is getting long, don't wait any longer for packets
2660 before the start of the queue. */
38ce7c73 2661 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
c6b20d94 2662 struct sk_buff *mskb = skb_peek(&ppp->mrq);
a00eac0c
DM		 2663 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence))
2664 ppp->minseq = PPP_MP_CB(mskb)->sequence;
38ce7c73 2665 }
1da177e4
LT		 2666
2667 /* Pull completed packets off the queue and receive them. */
82b3cc1a
BM		 2668 while ((skb = ppp_mp_reconstruct(ppp))) {
2669 if (pskb_may_pull(skb, 2))
2670 ppp_receive_nonmp_frame(ppp, skb);
2671 else {
2672 ++ppp->dev->stats.rx_length_errors;
2673 kfree_skb(skb);
2674 ppp_receive_error(ppp);
2675 }
2676 }
1da177e4
LT		 2677
2678 return;
2679
2680 err:
2681 kfree_skb(skb);
2682 ppp_receive_error(ppp);
2683}
2684
2685/*
2686 * Insert a fragment on the MP reconstruction queue.
2687 * The queue is ordered by increasing sequence number.
2688 */
2689static void
2690ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
2691{
2692 struct sk_buff *p;
2693 struct sk_buff_head *list = &ppp->mrq;
a00eac0c 2694 u32 seq = PPP_MP_CB(skb)->sequence;
1da177e4
LT		 2695
2696 /* N.B. we don't need to lock the list lock because we have the
2697 ppp unit receive-side lock. */
13c9821e 2698 skb_queue_walk(list, p) {
a00eac0c 2699 if (seq_before(seq, PPP_MP_CB(p)->sequence))
1da177e4 2700 break;
13c9821e 2701 }
43f59c89 2702 __skb_queue_before(list, p, skb);
1da177e4
LT		 2703}
2704
2705/*
2706 * Reconstruct a packet from the MP fragment queue.
2707 * We go through increasing sequence numbers until we find a
2708 * complete packet, or we get to the sequence number for a fragment
2709 * which hasn't arrived but might still do so.
2710 */
3c582b30 2711static struct sk_buff *
1da177e4
LT		 2712ppp_mp_reconstruct(struct ppp *ppp)
2713{
2714 u32 seq = ppp->nextseq;
2715 u32 minseq = ppp->minseq;
2716 struct sk_buff_head *list = &ppp->mrq;
d52344a7 2717 struct sk_buff *p, *tmp;
1da177e4
LT		 2718 struct sk_buff *head, *tail;
2719 struct sk_buff *skb = NULL;
2720 int lost = 0, len = 0;
2721
2722 if (ppp->mrru == 0) /* do nothing until mrru is set */
2723 return NULL;
8b69bd7d 2724 head = __skb_peek(list);
1da177e4 2725 tail = NULL;
d52344a7
DM		 2726 skb_queue_walk_safe(list, p, tmp) {
2727 again:
a00eac0c 2728 if (seq_before(PPP_MP_CB(p)->sequence, seq)) {
1da177e4 2729 /* this can't happen, anyway ignore the skb */
b48f8c23
DM		 2730 netdev_err(ppp->dev, "ppp_mp_reconstruct bad "
2731 "seq %u < %u\n",
2732 PPP_MP_CB(p)->sequence, seq);
d52344a7
DM		 2733 __skb_unlink(p, list);
2734 kfree_skb(p);
1da177e4
LT		 2735 continue;
2736 }
a00eac0c 2737 if (PPP_MP_CB(p)->sequence != seq) {
8a49ad6e 2738 u32 oldseq;
1da177e4
LT		 2739 /* Fragment `seq' is missing. If it is after
2740 minseq, it might arrive later, so stop here. */
2741 if (seq_after(seq, minseq))
2742 break;
2743 /* Fragment `seq' is lost, keep going. */
2744 lost = 1;
8a49ad6e 2745 oldseq = seq;
a00eac0c
DM		 2746 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)?
2747 minseq + 1: PPP_MP_CB(p)->sequence;
8a49ad6e
BM		 2748
2749 if (ppp->debug & 1)
2750 netdev_printk(KERN_DEBUG, ppp->dev,
2751 "lost frag %u..%u\n",
2752 oldseq, seq-1);
2753
d52344a7 2754 goto again;
1da177e4
LT		 2755 }
2756
2757 /*
2758 * At this point we know that all the fragments from
2759 * ppp->nextseq to seq are either present or lost.
2760 * Also, there are no complete packets in the queue
2761 * that have no missing fragments and end before this
2762 * fragment.
2763 */
2764
2765 /* B bit set indicates this fragment starts a packet */
a00eac0c 2766 if (PPP_MP_CB(p)->BEbits & B) {
1da177e4
LT		 2767 head = p;
2768 lost = 0;
2769 len = 0;
2770 }
2771
2772 len += p->len;
2773
2774 /* Got a complete packet yet? */
a00eac0c
DM		 2775 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) &&
2776 (PPP_MP_CB(head)->BEbits & B)) {
1da177e4 2777 if (len > ppp->mrru + 2) {
8c0469cd 2778 ++ppp->dev->stats.rx_length_errors;
b48f8c23
DM		 2779 netdev_printk(KERN_DEBUG, ppp->dev,
2780 "PPP: reconstructed packet"
2781 " is too long (%d)\n", len);
1da177e4
LT		 2782 } else {
2783 tail = p;
2784 break;
2785 }
2786 ppp->nextseq = seq + 1;
2787 }
2788
2789 /*
2790 * If this is the ending fragment of a packet,
2791 * and we haven't found a complete valid packet yet,
2792 * we can discard up to and including this fragment.
2793 */
d52344a7
DM		 2794 if (PPP_MP_CB(p)->BEbits & E) {
2795 struct sk_buff *tmp2;
1da177e4 2796
d52344a7 2797 skb_queue_reverse_walk_from_safe(list, p, tmp2) {
8a49ad6e
BM		 2798 if (ppp->debug & 1)
2799 netdev_printk(KERN_DEBUG, ppp->dev,
2800 "discarding frag %u\n",
2801 PPP_MP_CB(p)->sequence);
d52344a7
DM		 2802 __skb_unlink(p, list);
2803 kfree_skb(p);
2804 }
2805 head = skb_peek(list);
2806 if (!head)
2807 break;
2808 }
1da177e4
LT		 2809 ++seq;
2810 }
2811
2812 /* If we have a complete packet, copy it all into one skb. */
2813 if (tail != NULL) {
2814 /* If we have discarded any fragments,
2815 signal a receive error. */
a00eac0c 2816 if (PPP_MP_CB(head)->sequence != ppp->nextseq) {
8a49ad6e
BM		 2817 skb_queue_walk_safe(list, p, tmp) {
2818 if (p == head)
2819 break;
2820 if (ppp->debug & 1)
2821 netdev_printk(KERN_DEBUG, ppp->dev,
2822 "discarding frag %u\n",
2823 PPP_MP_CB(p)->sequence);
2824 __skb_unlink(p, list);
2825 kfree_skb(p);
2826 }
2827
1da177e4 2828 if (ppp->debug & 1)
b48f8c23
DM		 2829 netdev_printk(KERN_DEBUG, ppp->dev,
2830 " missed pkts %u..%u\n",
2831 ppp->nextseq,
2832 PPP_MP_CB(head)->sequence-1);
8c0469cd 2833 ++ppp->dev->stats.rx_dropped;
1da177e4
LT		 2834 ppp_receive_error(ppp);
2835 }
2836
212bfb9e
DM		 2837 skb = head;
2838 if (head != tail) {
2839 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list;
2840 p = skb_queue_next(list, head);
2841 __skb_unlink(skb, list);
2842 skb_queue_walk_from_safe(list, p, tmp) {
2843 __skb_unlink(p, list);
2844 *fragpp = p;
2845 p->next = NULL;
2846 fragpp = &p->next;
2847
2848 skb->len += p->len;
2849 skb->data_len += p->len;
19c6c8f5 2850 skb->truesize += p->truesize;
212bfb9e
DM		 2851
2852 if (p == tail)
2853 break;
2854 }
2855 } else {
2856 __skb_unlink(skb, list);
2857 }
2858
a00eac0c 2859 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1;
1da177e4
LT		 2860 }
2861
2862 return skb;
2863}
2864#endif /* CONFIG_PPP_MULTILINK */
2865
2866/*
2867 * Channel interface.
2868 */
2869
273ec51d
CG		 2870/* Create a new, unattached ppp channel. */
2871int ppp_register_channel(struct ppp_channel *chan)
2872{
2873 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2874}
2875
2876/* Create a new, unattached ppp channel for specified net. */
2877int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
1da177e4
LT		 2878{
2879 struct channel *pch;
273ec51d 2880 struct ppp_net *pn;
1da177e4 2881
d4274b51 2882 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
cd228d54 2883 if (!pch)
1da177e4 2884 return -ENOMEM;
273ec51d
CG		 2885
2886 pn = ppp_pernet(net);
2887
1da177e4
LT		 2888 pch->ppp = NULL;
2889 pch->chan = chan;
11b311a8 2890 pch->chan_net = get_net_track(net, &pch->ns_tracker, GFP_KERNEL);
1da177e4
LT		 2891 chan->ppp = pch;
2892 init_ppp_file(&pch->file, CHANNEL);
2893 pch->file.hdrlen = chan->hdrlen;
2894#ifdef CONFIG_PPP_MULTILINK
2895 pch->lastseq = -1;
2896#endif /* CONFIG_PPP_MULTILINK */
2897 init_rwsem(&pch->chan_sem);
2898 spin_lock_init(&pch->downl);
2899 rwlock_init(&pch->upl);
273ec51d
CG		 2900
2901 spin_lock_bh(&pn->all_channels_lock);
2902 pch->file.index = ++pn->last_channel_index;
2903 list_add(&pch->list, &pn->new_channels);
1da177e4 2904 atomic_inc(&channel_count);
273ec51d
CG		 2905 spin_unlock_bh(&pn->all_channels_lock);
2906
1da177e4
LT		 2907 return 0;
2908}
2909
2910/*
2911 * Return the index of a channel.
2912 */
2913int ppp_channel_index(struct ppp_channel *chan)
2914{
2915 struct channel *pch = chan->ppp;
2916
cd228d54 2917 if (pch)
1da177e4
LT		 2918 return pch->file.index;
2919 return -1;
2920}
2921
2922/*
2923 * Return the PPP unit number to which a channel is connected.
2924 */
2925int ppp_unit_number(struct ppp_channel *chan)
2926{
2927 struct channel *pch = chan->ppp;
2928 int unit = -1;
2929
cd228d54 2930 if (pch) {
1da177e4 2931 read_lock_bh(&pch->upl);
cd228d54 2932 if (pch->ppp)
1da177e4
LT		 2933 unit = pch->ppp->file.index;
2934 read_unlock_bh(&pch->upl);
2935 }
2936 return unit;
2937}
2938
63f96072
JC		 2939/*
2940 * Return the PPP device interface name of a channel.
2941 */
2942char *ppp_dev_name(struct ppp_channel *chan)
2943{
2944 struct channel *pch = chan->ppp;
2945 char *name = NULL;
2946
2947 if (pch) {
2948 read_lock_bh(&pch->upl);
2949 if (pch->ppp && pch->ppp->dev)
2950 name = pch->ppp->dev->name;
2951 read_unlock_bh(&pch->upl);
2952 }
2953 return name;
2954}
2955
2956
1da177e4
LT		 2957/*
2958 * Disconnect a channel from the generic layer.
2959 * This must be called in process context.
2960 */
2961void
2962ppp_unregister_channel(struct ppp_channel *chan)
2963{
2964 struct channel *pch = chan->ppp;
273ec51d 2965 struct ppp_net *pn;
1da177e4 2966
cd228d54 2967 if (!pch)
1da177e4 2968 return; /* should never happen */
273ec51d 2969
1da177e4
LT		 2970 chan->ppp = NULL;
2971
2972 /*
959edef6 2973 * This ensures that we have returned from any calls into
1da177e4
LT		 2974 * the channel's start_xmit or ioctl routine before we proceed.
2975 */
2976 down_write(&pch->chan_sem);
2977 spin_lock_bh(&pch->downl);
2978 pch->chan = NULL;
2979 spin_unlock_bh(&pch->downl);
2980 up_write(&pch->chan_sem);
2981 ppp_disconnect_channel(pch);
273ec51d
CG		 2982
2983 pn = ppp_pernet(pch->chan_net);
2984 spin_lock_bh(&pn->all_channels_lock);
1da177e4 2985 list_del(&pch->list);
273ec51d
CG		 2986 spin_unlock_bh(&pn->all_channels_lock);
2987
4cf476ce
TP		 2988 ppp_unbridge_channels(pch);
2989
1da177e4
LT		 2990 pch->file.dead = 1;
2991 wake_up_interruptible(&pch->file.rwait);
4cf476ce 2992
d780cd44 2993 if (refcount_dec_and_test(&pch->file.refcnt))
1da177e4
LT		 2994 ppp_destroy_channel(pch);
2995}
2996
2997/*
2998 * Callback from a channel when it can accept more to transmit.
2999 * This should be called at BH/softirq level, not interrupt level.
3000 */
3001void
3002ppp_output_wakeup(struct ppp_channel *chan)
3003{
3004 struct channel *pch = chan->ppp;
3005
cd228d54 3006 if (!pch)
1da177e4
LT		 3007 return;
3008 ppp_channel_push(pch);
3009}
3010
3011/*
3012 * Compression control.
3013 */
3014
3015/* Process the PPPIOCSCOMPRESS ioctl. */
3016static int
5b6c02df 3017ppp_set_compress(struct ppp *ppp, struct ppp_option_data *data)
1da177e4 3018{
5b6c02df 3019 int err = -EFAULT;
1da177e4 3020 struct compressor *cp, *ocomp;
1da177e4
LT		 3021 void *state, *ostate;
3022 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
3023
5b6c02df 3024 if (data->length > CCP_MAX_OPTION_LENGTH)
555d5b70 3025 goto out;
5b6c02df 3026 if (copy_from_user(ccp_option, data->ptr, data->length))
555d5b70
GN		 3027 goto out;
3028
1da177e4 3029 err = -EINVAL;
5b6c02df 3030 if (data->length < 2 || ccp_option[1] < 2 || ccp_option[1] > data->length)
1da177e4
LT		 3031 goto out;
3032
a65e5d78
JB		 3033 cp = try_then_request_module(
3034 find_compressor(ccp_option[0]),
3035 "ppp-compress-%d", ccp_option[0]);
cd228d54 3036 if (!cp)
1da177e4
LT		 3037 goto out;
3038
3039 err = -ENOBUFS;
5b6c02df
AV		 3040 if (data->transmit) {
3041 state = cp->comp_alloc(ccp_option, data->length);
cd228d54 3042 if (state) {
1da177e4
LT		 3043 ppp_xmit_lock(ppp);
3044 ppp->xstate &= ~SC_COMP_RUN;
3045 ocomp = ppp->xcomp;
3046 ostate = ppp->xc_state;
3047 ppp->xcomp = cp;
3048 ppp->xc_state = state;
3049 ppp_xmit_unlock(ppp);
cd228d54 3050 if (ostate) {
1da177e4
LT		 3051 ocomp->comp_free(ostate);
3052 module_put(ocomp->owner);
3053 }
3054 err = 0;
3055 } else
3056 module_put(cp->owner);
3057
3058 } else {
5b6c02df 3059 state = cp->decomp_alloc(ccp_option, data->length);
cd228d54 3060 if (state) {
1da177e4
LT		 3061 ppp_recv_lock(ppp);
3062 ppp->rstate &= ~SC_DECOMP_RUN;
3063 ocomp = ppp->rcomp;
3064 ostate = ppp->rc_state;
3065 ppp->rcomp = cp;
3066 ppp->rc_state = state;
3067 ppp_recv_unlock(ppp);
cd228d54 3068 if (ostate) {
1da177e4
LT		 3069 ocomp->decomp_free(ostate);
3070 module_put(ocomp->owner);
3071 }
3072 err = 0;
3073 } else
3074 module_put(cp->owner);
3075 }
3076
3077 out:
3078 return err;
3079}
3080
3081/*
3082 * Look at a CCP packet and update our state accordingly.
3083 * We assume the caller has the xmit or recv path locked.
3084 */
3085static void
3086ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
3087{
3088 unsigned char *dp;
3089 int len;
3090
3091 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
3092 return; /* no header */
3093 dp = skb->data + 2;
3094
3095 switch (CCP_CODE(dp)) {
3096 case CCP_CONFREQ:
3097
6aa20a22 3098 /* A ConfReq starts negotiation of compression
1da177e4
LT		 3099 * in one direction of transmission,
3100 * and hence brings it down...but which way?
3101 *
3102 * Remember:
3103 * A ConfReq indicates what the sender would like to receive
3104 */
3105 if(inbound)
3106 /* He is proposing what I should send */
3107 ppp->xstate &= ~SC_COMP_RUN;
6aa20a22 3108 else
1da177e4
LT		 3109 /* I am proposing to what he should send */
3110 ppp->rstate &= ~SC_DECOMP_RUN;
6aa20a22 3111
1da177e4 3112 break;
6aa20a22 3113
1da177e4
LT		 3114 case CCP_TERMREQ:
3115 case CCP_TERMACK:
3116 /*
6aa20a22 3117 * CCP is going down, both directions of transmission
1da177e4
LT		 3118 */
3119 ppp->rstate &= ~SC_DECOMP_RUN;
3120 ppp->xstate &= ~SC_COMP_RUN;
3121 break;
3122
3123 case CCP_CONFACK:
3124 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
3125 break;
3126 len = CCP_LENGTH(dp);
3127 if (!pskb_may_pull(skb, len + 2))
3128 return; /* too short */
3129 dp += CCP_HDRLEN;
3130 len -= CCP_HDRLEN;
3131 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
3132 break;
3133 if (inbound) {
3134 /* we will start receiving compressed packets */
cd228d54 3135 if (!ppp->rc_state)
1da177e4
LT		 3136 break;
3137 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
3138 ppp->file.index, 0, ppp->mru, ppp->debug)) {
3139 ppp->rstate |= SC_DECOMP_RUN;
3140 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
3141 }
3142 } else {
3143 /* we will soon start sending compressed packets */
cd228d54 3144 if (!ppp->xc_state)
1da177e4
LT		 3145 break;
3146 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
3147 ppp->file.index, 0, ppp->debug))
3148 ppp->xstate |= SC_COMP_RUN;
3149 }
3150 break;
3151
3152 case CCP_RESETACK:
3153 /* reset the [de]compressor */
3154 if ((ppp->flags & SC_CCP_UP) == 0)
3155 break;
3156 if (inbound) {
3157 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
3158 ppp->rcomp->decomp_reset(ppp->rc_state);
3159 ppp->rstate &= ~SC_DC_ERROR;
3160 }
3161 } else {
3162 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
3163 ppp->xcomp->comp_reset(ppp->xc_state);
3164 }
3165 break;
3166 }
3167}
3168
3169/* Free up compression resources. */
3170static void
3171ppp_ccp_closed(struct ppp *ppp)
3172{
3173 void *xstate, *rstate;
3174 struct compressor *xcomp, *rcomp;
3175
3176 ppp_lock(ppp);
3177 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
3178 ppp->xstate = 0;
3179 xcomp = ppp->xcomp;
3180 xstate = ppp->xc_state;
3181 ppp->xc_state = NULL;
3182 ppp->rstate = 0;
3183 rcomp = ppp->rcomp;
3184 rstate = ppp->rc_state;
3185 ppp->rc_state = NULL;
3186 ppp_unlock(ppp);
3187
3188 if (xstate) {
3189 xcomp->comp_free(xstate);
3190 module_put(xcomp->owner);
3191 }
3192 if (rstate) {
3193 rcomp->decomp_free(rstate);
3194 module_put(rcomp->owner);
3195 }
3196}
3197
3198/* List of compressors. */
3199static LIST_HEAD(compressor_list);
3200static DEFINE_SPINLOCK(compressor_list_lock);
3201
3202struct compressor_entry {
3203 struct list_head list;
3204 struct compressor *comp;
3205};
3206
3207static struct compressor_entry *
3208find_comp_entry(int proto)
3209{
3210 struct compressor_entry *ce;
1da177e4 3211
81616c5a 3212 list_for_each_entry(ce, &compressor_list, list) {
1da177e4
LT		 3213 if (ce->comp->compress_proto == proto)
3214 return ce;
3215 }
3216 return NULL;
3217}
3218
3219/* Register a compressor */
3220int
3221ppp_register_compressor(struct compressor *cp)
3222{
3223 struct compressor_entry *ce;
3224 int ret;
3225 spin_lock(&compressor_list_lock);
3226 ret = -EEXIST;
cd228d54 3227 if (find_comp_entry(cp->compress_proto))
1da177e4
LT		 3228 goto out;
3229 ret = -ENOMEM;
3230 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
cd228d54 3231 if (!ce)
1da177e4
LT		 3232 goto out;
3233 ret = 0;
3234 ce->comp = cp;
3235 list_add(&ce->list, &compressor_list);
3236 out:
3237 spin_unlock(&compressor_list_lock);
3238 return ret;
3239}
3240
3241/* Unregister a compressor */
3242void
3243ppp_unregister_compressor(struct compressor *cp)
3244{
3245 struct compressor_entry *ce;
3246
3247 spin_lock(&compressor_list_lock);
3248 ce = find_comp_entry(cp->compress_proto);
cd228d54 3249 if (ce && ce->comp == cp) {
1da177e4
LT		 3250 list_del(&ce->list);
3251 kfree(ce);
3252 }
3253 spin_unlock(&compressor_list_lock);
3254}
3255
3256/* Find a compressor. */
3257static struct compressor *
3258find_compressor(int type)
3259{
3260 struct compressor_entry *ce;
3261 struct compressor *cp = NULL;
3262
3263 spin_lock(&compressor_list_lock);
3264 ce = find_comp_entry(type);
cd228d54 3265 if (ce) {
1da177e4
LT		 3266 cp = ce->comp;
3267 if (!try_module_get(cp->owner))
3268 cp = NULL;
3269 }
3270 spin_unlock(&compressor_list_lock);
3271 return cp;
3272}
3273
3274/*
3275 * Miscelleneous stuff.
3276 */
3277
3278static void
3279ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
3280{
3281 struct slcompress *vj = ppp->vj;
3282
3283 memset(st, 0, sizeof(*st));
e51f6ff3 3284 st->p.ppp_ipackets = ppp->stats64.rx_packets;
8c0469cd 3285 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
e51f6ff3
KG		 3286 st->p.ppp_ibytes = ppp->stats64.rx_bytes;
3287 st->p.ppp_opackets = ppp->stats64.tx_packets;
8c0469cd 3288 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
e51f6ff3 3289 st->p.ppp_obytes = ppp->stats64.tx_bytes;
cd228d54 3290 if (!vj)
1da177e4
LT		 3291 return;
3292 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
3293 st->vj.vjs_compressed = vj->sls_o_compressed;
3294 st->vj.vjs_searches = vj->sls_o_searches;
3295 st->vj.vjs_misses = vj->sls_o_misses;
3296 st->vj.vjs_errorin = vj->sls_i_error;
3297 st->vj.vjs_tossed = vj->sls_i_tossed;
3298 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
3299 st->vj.vjs_compressedin = vj->sls_i_compressed;
3300}
3301
3302/*
3303 * Stuff for handling the lists of ppp units and channels
3304 * and for initialization.
3305 */
3306
3307/*
3308 * Create a new ppp interface unit. Fails if it can't allocate memory
3309 * or if there is already a unit with the requested number.
3310 * unit == -1 means allocate a new number.
3311 */
7d9f0b48 3312static int ppp_create_interface(struct net *net, struct file *file, int *unit)
1da177e4 3313{
7d9f0b48
GN		 3314 struct ppp_config conf = {
3315 .file = file,
3316 .unit = *unit,
96d934c7 3317 .ifname_is_set = false,
7d9f0b48
GN		 3318 };
3319 struct net_device *dev;
1da177e4 3320 struct ppp *ppp;
7d9f0b48 3321 int err;
1da177e4 3322
69d9728d 3323 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_ENUM, ppp_setup);
7d9f0b48
GN		 3324 if (!dev) {
3325 err = -ENOMEM;
3326 goto err;
3327 }
273ec51d 3328 dev_net_set(dev, net);
96d934c7 3329 dev->rtnl_link_ops = &ppp_link_ops;
273ec51d 3330
58a89eca 3331 rtnl_lock();
1da177e4 3332
7d9f0b48
GN		 3333 err = ppp_dev_configure(net, dev, &conf);
3334 if (err < 0)
3335 goto err_dev;
3336 ppp = netdev_priv(dev);
3337 *unit = ppp->file.index;
273ec51d 3338
58a89eca 3339 rtnl_unlock();
7a95d267 3340
7d9f0b48 3341 return 0;
1da177e4 3342
7d9f0b48 3343err_dev:
6faac63a 3344 rtnl_unlock();
1da177e4 3345 free_netdev(dev);
7d9f0b48
GN		 3346err:
3347 return err;
1da177e4
LT		 3348}
3349
3350/*
3351 * Initialize a ppp_file structure.
3352 */
3353static void
3354init_ppp_file(struct ppp_file *pf, int kind)
3355{
3356 pf->kind = kind;
3357 skb_queue_head_init(&pf->xq);
3358 skb_queue_head_init(&pf->rq);
d780cd44 3359 refcount_set(&pf->refcnt, 1);
1da177e4
LT		 3360 init_waitqueue_head(&pf->rwait);
3361}
3362
1da177e4
LT		 3363/*
3364 * Free the memory used by a ppp unit. This is only called once
3365 * there are no channels connected to the unit and no file structs
3366 * that reference the unit.
3367 */
3368static void ppp_destroy_interface(struct ppp *ppp)
3369{
3370 atomic_dec(&ppp_unit_count);
3371
3372 if (!ppp->file.dead || ppp->n_channels) {
3373 /* "can't happen" */
b48f8c23
DM		 3374 netdev_err(ppp->dev, "ppp: destroying ppp struct %p "
3375 "but dead=%d n_channels=%d !\n",
3376 ppp, ppp->file.dead, ppp->n_channels);
1da177e4
LT		 3377 return;
3378 }
3379
3380 ppp_ccp_closed(ppp);
3381 if (ppp->vj) {
3382 slhc_free(ppp->vj);
3383 ppp->vj = NULL;
3384 }
3385 skb_queue_purge(&ppp->file.xq);
3386 skb_queue_purge(&ppp->file.rq);
3387#ifdef CONFIG_PPP_MULTILINK
3388 skb_queue_purge(&ppp->mrq);
3389#endif /* CONFIG_PPP_MULTILINK */
3390#ifdef CONFIG_PPP_FILTER
568f194e 3391 if (ppp->pass_filter) {
7ae457c1 3392 bpf_prog_destroy(ppp->pass_filter);
568f194e
DB		 3393 ppp->pass_filter = NULL;
3394 }
3395
3396 if (ppp->active_filter) {
7ae457c1 3397 bpf_prog_destroy(ppp->active_filter);
568f194e
DB		 3398 ppp->active_filter = NULL;
3399 }
1da177e4
LT		 3400#endif /* CONFIG_PPP_FILTER */
3401
1d2f8c95 3402 kfree_skb(ppp->xmit_pending);
e5dadc65 3403 free_percpu(ppp->xmit_recursion);
165de5b7 3404
739840d5 3405 free_netdev(ppp->dev);
1da177e4
LT		 3406}
3407
3408/*
3409 * Locate an existing ppp unit.
8ed965d6 3410 * The caller should have locked the all_ppp_mutex.
1da177e4
LT		 3411 */
3412static struct ppp *
273ec51d 3413ppp_find_unit(struct ppp_net *pn, int unit)
1da177e4 3414{
273ec51d 3415 return unit_find(&pn->units_idr, unit);
1da177e4
LT		 3416}
3417
3418/*
3419 * Locate an existing ppp channel.
3420 * The caller should have locked the all_channels_lock.
3421 * First we look in the new_channels list, then in the
3422 * all_channels list. If found in the new_channels list,
3423 * we move it to the all_channels list. This is for speed
3424 * when we have a lot of channels in use.
3425 */
3426static struct channel *
273ec51d 3427ppp_find_channel(struct ppp_net *pn, int unit)
1da177e4
LT		 3428{
3429 struct channel *pch;
1da177e4 3430
273ec51d 3431 list_for_each_entry(pch, &pn->new_channels, list) {
1da177e4 3432 if (pch->file.index == unit) {
273ec51d 3433 list_move(&pch->list, &pn->all_channels);
1da177e4
LT		 3434 return pch;
3435 }
3436 }
273ec51d
CG		 3437
3438 list_for_each_entry(pch, &pn->all_channels, list) {
1da177e4
LT		 3439 if (pch->file.index == unit)
3440 return pch;
3441 }
273ec51d 3442
1da177e4
LT		 3443 return NULL;
3444}
3445
3446/*
3447 * Connect a PPP channel to a PPP interface unit.
3448 */
3449static int
3450ppp_connect_channel(struct channel *pch, int unit)
3451{
3452 struct ppp *ppp;
273ec51d 3453 struct ppp_net *pn;
1da177e4
LT		 3454 int ret = -ENXIO;
3455 int hdrlen;
3456
273ec51d
CG		 3457 pn = ppp_pernet(pch->chan_net);
3458
3459 mutex_lock(&pn->all_ppp_mutex);
3460 ppp = ppp_find_unit(pn, unit);
cd228d54 3461 if (!ppp)
1da177e4
LT		 3462 goto out;
3463 write_lock_bh(&pch->upl);
3464 ret = -EINVAL;
4cf476ce
TP		 3465 if (pch->ppp ||
3466 rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl)))
1da177e4
LT		 3467 goto outl;
3468
3469 ppp_lock(ppp);
77f840e3
GN		 3470 spin_lock_bh(&pch->downl);
3471 if (!pch->chan) {
3472 /* Don't connect unregistered channels */
3473 spin_unlock_bh(&pch->downl);
3474 ppp_unlock(ppp);
3475 ret = -ENOTCONN;
3476 goto outl;
3477 }
3478 spin_unlock_bh(&pch->downl);
1da177e4
LT		 3479 if (pch->file.hdrlen > ppp->file.hdrlen)
3480 ppp->file.hdrlen = pch->file.hdrlen;
3481 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
739840d5 3482 if (hdrlen > ppp->dev->hard_header_len)
1da177e4
LT		 3483 ppp->dev->hard_header_len = hdrlen;
3484 list_add_tail(&pch->clist, &ppp->channels);
3485 ++ppp->n_channels;
3486 pch->ppp = ppp;
d780cd44 3487 refcount_inc(&ppp->file.refcnt);
1da177e4
LT		 3488 ppp_unlock(ppp);
3489 ret = 0;
3490
3491 outl:
3492 write_unlock_bh(&pch->upl);
3493 out:
273ec51d 3494 mutex_unlock(&pn->all_ppp_mutex);
1da177e4
LT		 3495 return ret;
3496}
3497
3498/*
3499 * Disconnect a channel from its ppp unit.
3500 */
3501static int
3502ppp_disconnect_channel(struct channel *pch)
3503{
3504 struct ppp *ppp;
3505 int err = -EINVAL;
3506
3507 write_lock_bh(&pch->upl);
3508 ppp = pch->ppp;
3509 pch->ppp = NULL;
3510 write_unlock_bh(&pch->upl);
cd228d54 3511 if (ppp) {
1da177e4
LT		 3512 /* remove it from the ppp unit's list */
3513 ppp_lock(ppp);
3514 list_del(&pch->clist);
3515 if (--ppp->n_channels == 0)
3516 wake_up_interruptible(&ppp->file.rwait);
3517 ppp_unlock(ppp);
d780cd44 3518 if (refcount_dec_and_test(&ppp->file.refcnt))
1da177e4
LT		 3519 ppp_destroy_interface(ppp);
3520 err = 0;
3521 }
3522 return err;
3523}
3524
3525/*
3526 * Free up the resources used by a ppp channel.
3527 */
3528static void ppp_destroy_channel(struct channel *pch)
3529{
11b311a8 3530 put_net_track(pch->chan_net, &pch->ns_tracker);
205e1e25
WC		 3531 pch->chan_net = NULL;
3532
1da177e4
LT		 3533 atomic_dec(&channel_count);
3534
3535 if (!pch->file.dead) {
3536 /* "can't happen" */
b48f8c23 3537 pr_err("ppp: destroying undead channel %p !\n", pch);
1da177e4
LT		 3538 return;
3539 }
3540 skb_queue_purge(&pch->file.xq);
3541 skb_queue_purge(&pch->file.rq);
3542 kfree(pch);
3543}
3544
3545static void __exit ppp_cleanup(void)
3546{
3547 /* should never happen */
3548 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
b48f8c23 3549 pr_err("PPP: removing module but units remain!\n");
96d934c7 3550 rtnl_link_unregister(&ppp_link_ops);
68fc4fab 3551 unregister_chrdev(PPP_MAJOR, "ppp");
9a6a2a5e 3552 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
56b22935 3553 class_destroy(ppp_class);
741a6fa2 3554 unregister_pernet_device(&ppp_net_ops);
1da177e4
LT		 3555}
3556
3557/*
7a95d267
CG		 3558 * Units handling. Caller must protect concurrent access
3559 * by holding all_ppp_mutex
1da177e4 3560 */
7a95d267 3561
bcc70bb3
CG		 3562/* associate pointer with specified number */
3563static int unit_set(struct idr *p, void *ptr, int n)
3564{
3565 int unit;
85997576 3566
2fa532c5
TH		 3567 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL);
3568 if (unit == -ENOSPC)
3569 unit = -EINVAL;
85997576
CG		 3570 return unit;
3571}
3572
7a95d267 3573/* get new free unit number and associate pointer with it */
3125f26c 3574static int unit_get(struct idr *p, void *ptr, int min)
1da177e4 3575{
3125f26c 3576 return idr_alloc(p, ptr, min, 0, GFP_KERNEL);
1da177e4
LT		 3577}
3578
7a95d267
CG		 3579/* put unit number back to a pool */
3580static void unit_put(struct idr *p, int n)
1da177e4 3581{
7a95d267 3582 idr_remove(p, n);
1da177e4
LT		 3583}
3584
7a95d267
CG		 3585/* get pointer associated with the number */
3586static void *unit_find(struct idr *p, int n)
1da177e4 3587{
7a95d267 3588 return idr_find(p, n);
1da177e4
LT		 3589}
3590
3591/* Module/initialization stuff */
3592
3593module_init(ppp_init);
3594module_exit(ppp_cleanup);
3595
273ec51d 3596EXPORT_SYMBOL(ppp_register_net_channel);
1da177e4
LT		 3597EXPORT_SYMBOL(ppp_register_channel);
3598EXPORT_SYMBOL(ppp_unregister_channel);
3599EXPORT_SYMBOL(ppp_channel_index);
3600EXPORT_SYMBOL(ppp_unit_number);
63f96072 3601EXPORT_SYMBOL(ppp_dev_name);
1da177e4
LT		 3602EXPORT_SYMBOL(ppp_input);
3603EXPORT_SYMBOL(ppp_input_error);
3604EXPORT_SYMBOL(ppp_output_wakeup);
3605EXPORT_SYMBOL(ppp_register_compressor);
3606EXPORT_SYMBOL(ppp_unregister_compressor);
3607MODULE_LICENSE("GPL");
578454ff 3608MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
96d934c7 3609MODULE_ALIAS_RTNL_LINK("ppp");
578454ff 3610MODULE_ALIAS("devname:ppp");
Linux 6.x block layer and io_uring tree(s)