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[net-next-2.6.git] / drivers / net / ppp_generic.c
CommitLineData
1da177e4
LT		 1/*
2 * Generic PPP layer for Linux.
3 *
4 * Copyright 1999-2002 Paul Mackerras.
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 *
11 * The generic PPP layer handles the PPP network interfaces, the
12 * /dev/ppp device, packet and VJ compression, and multilink.
13 * It talks to PPP `channels' via the interface defined in
14 * include/linux/ppp_channel.h. Channels provide the basic means for
15 * sending and receiving PPP frames on some kind of communications
16 * channel.
17 *
18 * Part of the code in this driver was inspired by the old async-only
19 * PPP driver, written by Michael Callahan and Al Longyear, and
20 * subsequently hacked by Paul Mackerras.
21 *
22 * ==FILEVERSION 20041108==
23 */
24
1da177e4
LT		 25#include <linux/module.h>
26#include <linux/kernel.h>
27#include <linux/kmod.h>
28#include <linux/init.h>
29#include <linux/list.h>
7a95d267 30#include <linux/idr.h>
1da177e4
LT		 31#include <linux/netdevice.h>
32#include <linux/poll.h>
33#include <linux/ppp_defs.h>
34#include <linux/filter.h>
35#include <linux/if_ppp.h>
36#include <linux/ppp_channel.h>
37#include <linux/ppp-comp.h>
38#include <linux/skbuff.h>
39#include <linux/rtnetlink.h>
40#include <linux/if_arp.h>
41#include <linux/ip.h>
42#include <linux/tcp.h>
f2b9857e 43#include <linux/smp_lock.h>
1da177e4 44#include <linux/spinlock.h>
1da177e4
LT		 45#include <linux/rwsem.h>
46#include <linux/stddef.h>
47#include <linux/device.h>
8ed965d6 48#include <linux/mutex.h>
5a0e3ad6 49#include <linux/slab.h>
1da177e4
LT		 50#include <net/slhc_vj.h>
51#include <asm/atomic.h>
52
273ec51d
CG		 53#include <linux/nsproxy.h>
54#include <net/net_namespace.h>
55#include <net/netns/generic.h>
56
1da177e4
LT		 57#define PPP_VERSION "2.4.2"
58
59/*
60 * Network protocols we support.
61 */
62#define NP_IP 0 /* Internet Protocol V4 */
63#define NP_IPV6 1 /* Internet Protocol V6 */
64#define NP_IPX 2 /* IPX protocol */
65#define NP_AT 3 /* Appletalk protocol */
66#define NP_MPLS_UC 4 /* MPLS unicast */
67#define NP_MPLS_MC 5 /* MPLS multicast */
68#define NUM_NP 6 /* Number of NPs. */
69
70#define MPHDRLEN 6 /* multilink protocol header length */
71#define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */
1da177e4
LT		 72
73/*
74 * An instance of /dev/ppp can be associated with either a ppp
75 * interface unit or a ppp channel. In both cases, file->private_data
76 * points to one of these.
77 */
78struct ppp_file {
79 enum {
80 INTERFACE=1, CHANNEL
81 } kind;
82 struct sk_buff_head xq; /* pppd transmit queue */
83 struct sk_buff_head rq; /* receive queue for pppd */
84 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */
85 atomic_t refcnt; /* # refs (incl /dev/ppp attached) */
86 int hdrlen; /* space to leave for headers */
87 int index; /* interface unit / channel number */
88 int dead; /* unit/channel has been shut down */
89};
90
b385a144 91#define PF_TO_X(pf, X) container_of(pf, X, file)
1da177e4
LT		 92
93#define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
94#define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
95
1da177e4
LT		 96/*
97 * Data structure describing one ppp unit.
98 * A ppp unit corresponds to a ppp network interface device
99 * and represents a multilink bundle.
100 * It can have 0 or more ppp channels connected to it.
101 */
102struct ppp {
103 struct ppp_file file; /* stuff for read/write/poll 0 */
104 struct file *owner; /* file that owns this unit 48 */
105 struct list_head channels; /* list of attached channels 4c */
106 int n_channels; /* how many channels are attached 54 */
107 spinlock_t rlock; /* lock for receive side 58 */
108 spinlock_t wlock; /* lock for transmit side 5c */
109 int mru; /* max receive unit 60 */
110 unsigned int flags; /* control bits 64 */
111 unsigned int xstate; /* transmit state bits 68 */
112 unsigned int rstate; /* receive state bits 6c */
113 int debug; /* debug flags 70 */
114 struct slcompress *vj; /* state for VJ header compression */
115 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
116 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
117 struct compressor *xcomp; /* transmit packet compressor 8c */
118 void *xc_state; /* its internal state 90 */
119 struct compressor *rcomp; /* receive decompressor 94 */
120 void *rc_state; /* its internal state 98 */
121 unsigned long last_xmit; /* jiffies when last pkt sent 9c */
122 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
123 struct net_device *dev; /* network interface device a4 */
739840d5 124 int closing; /* is device closing down? a8 */
1da177e4
LT		 125#ifdef CONFIG_PPP_MULTILINK
126 int nxchan; /* next channel to send something on */
127 u32 nxseq; /* next sequence number to send */
128 int mrru; /* MP: max reconst. receive unit */
129 u32 nextseq; /* MP: seq no of next packet */
130 u32 minseq; /* MP: min of most recent seqnos */
131 struct sk_buff_head mrq; /* MP: receive reconstruction queue */
132#endif /* CONFIG_PPP_MULTILINK */
1da177e4
LT		 133#ifdef CONFIG_PPP_FILTER
134 struct sock_filter *pass_filter; /* filter for packets to pass */
135 struct sock_filter *active_filter;/* filter for pkts to reset idle */
136 unsigned pass_len, active_len;
137#endif /* CONFIG_PPP_FILTER */
273ec51d 138 struct net *ppp_net; /* the net we belong to */
1da177e4
LT		 139};
140
141/*
142 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
b3f9b92a
MD		 143 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
144 * SC_MUST_COMP
1da177e4
LT		 145 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
146 * Bits in xstate: SC_COMP_RUN
147 */
148#define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
149 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
b3f9b92a 150 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
1da177e4
LT		 151
152/*
153 * Private data structure for each channel.
154 * This includes the data structure used for multilink.
155 */
156struct channel {
157 struct ppp_file file; /* stuff for read/write/poll */
158 struct list_head list; /* link in all/new_channels list */
159 struct ppp_channel *chan; /* public channel data structure */
160 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
161 spinlock_t downl; /* protects `chan', file.xq dequeue */
162 struct ppp *ppp; /* ppp unit we're connected to */
273ec51d 163 struct net *chan_net; /* the net channel belongs to */
1da177e4
LT		 164 struct list_head clist; /* link in list of channels per unit */
165 rwlock_t upl; /* protects `ppp' */
166#ifdef CONFIG_PPP_MULTILINK
167 u8 avail; /* flag used in multilink stuff */
168 u8 had_frag; /* >= 1 fragments have been sent */
169 u32 lastseq; /* MP: last sequence # received */
fa44a73c 170 int speed; /* speed of the corresponding ppp channel*/
1da177e4
LT		 171#endif /* CONFIG_PPP_MULTILINK */
172};
173
174/*
175 * SMP locking issues:
176 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
177 * list and the ppp.n_channels field, you need to take both locks
178 * before you modify them.
179 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
180 * channel.downl.
181 */
182
1da177e4 183static atomic_t ppp_unit_count = ATOMIC_INIT(0);
1da177e4
LT		 184static atomic_t channel_count = ATOMIC_INIT(0);
185
273ec51d 186/* per-net private data for this module */
f99189b1 187static int ppp_net_id __read_mostly;
273ec51d
CG		 188struct ppp_net {
189 /* units to ppp mapping */
190 struct idr units_idr;
191
192 /*
193 * all_ppp_mutex protects the units_idr mapping.
194 * It also ensures that finding a ppp unit in the units_idr
195 * map and updating its file.refcnt field is atomic.
196 */
197 struct mutex all_ppp_mutex;
198
199 /* channels */
200 struct list_head all_channels;
201 struct list_head new_channels;
202 int last_channel_index;
203
204 /*
205 * all_channels_lock protects all_channels and
206 * last_channel_index, and the atomicity of find
207 * a channel and updating its file.refcnt field.
208 */
209 spinlock_t all_channels_lock;
210};
211
1da177e4
LT		 212/* Get the PPP protocol number from a skb */
213#define PPP_PROTO(skb) (((skb)->data[0] << 8) + (skb)->data[1])
214
215/* We limit the length of ppp->file.rq to this (arbitrary) value */
216#define PPP_MAX_RQLEN 32
217
218/*
219 * Maximum number of multilink fragments queued up.
220 * This has to be large enough to cope with the maximum latency of
221 * the slowest channel relative to the others. Strictly it should
222 * depend on the number of channels and their characteristics.
223 */
224#define PPP_MP_MAX_QLEN 128
225
226/* Multilink header bits. */
227#define B 0x80 /* this fragment begins a packet */
228#define E 0x40 /* this fragment ends a packet */
229
230/* Compare multilink sequence numbers (assumed to be 32 bits wide) */
231#define seq_before(a, b) ((s32)((a) - (b)) < 0)
232#define seq_after(a, b) ((s32)((a) - (b)) > 0)
233
234/* Prototypes. */
273ec51d
CG		 235static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
236 struct file *file, unsigned int cmd, unsigned long arg);
1da177e4
LT		 237static void ppp_xmit_process(struct ppp *ppp);
238static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
239static void ppp_push(struct ppp *ppp);
240static void ppp_channel_push(struct channel *pch);
241static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
242 struct channel *pch);
243static void ppp_receive_error(struct ppp *ppp);
244static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
245static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
246 struct sk_buff *skb);
247#ifdef CONFIG_PPP_MULTILINK
248static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
249 struct channel *pch);
250static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
251static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
252static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
253#endif /* CONFIG_PPP_MULTILINK */
254static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
255static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
256static void ppp_ccp_closed(struct ppp *ppp);
257static struct compressor *find_compressor(int type);
258static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
273ec51d 259static struct ppp *ppp_create_interface(struct net *net, int unit, int *retp);
1da177e4
LT		 260static void init_ppp_file(struct ppp_file *pf, int kind);
261static void ppp_shutdown_interface(struct ppp *ppp);
262static void ppp_destroy_interface(struct ppp *ppp);
273ec51d
CG		 263static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit);
264static struct channel *ppp_find_channel(struct ppp_net *pn, int unit);
1da177e4
LT		 265static int ppp_connect_channel(struct channel *pch, int unit);
266static int ppp_disconnect_channel(struct channel *pch);
267static void ppp_destroy_channel(struct channel *pch);
7a95d267 268static int unit_get(struct idr *p, void *ptr);
85997576 269static int unit_set(struct idr *p, void *ptr, int n);
7a95d267
CG		 270static void unit_put(struct idr *p, int n);
271static void *unit_find(struct idr *p, int n);
1da177e4 272
56b22935 273static struct class *ppp_class;
1da177e4 274
273ec51d
CG		 275/* per net-namespace data */
276static inline struct ppp_net *ppp_pernet(struct net *net)
277{
278 BUG_ON(!net);
279
280 return net_generic(net, ppp_net_id);
281}
282
1da177e4
LT		 283/* Translates a PPP protocol number to a NP index (NP == network protocol) */
284static inline int proto_to_npindex(int proto)
285{
286 switch (proto) {
287 case PPP_IP:
288 return NP_IP;
289 case PPP_IPV6:
290 return NP_IPV6;
291 case PPP_IPX:
292 return NP_IPX;
293 case PPP_AT:
294 return NP_AT;
295 case PPP_MPLS_UC:
296 return NP_MPLS_UC;
297 case PPP_MPLS_MC:
298 return NP_MPLS_MC;
299 }
300 return -EINVAL;
301}
302
303/* Translates an NP index into a PPP protocol number */
304static const int npindex_to_proto[NUM_NP] = {
305 PPP_IP,
306 PPP_IPV6,
307 PPP_IPX,
308 PPP_AT,
309 PPP_MPLS_UC,
310 PPP_MPLS_MC,
311};
6aa20a22 312
1da177e4
LT		 313/* Translates an ethertype into an NP index */
314static inline int ethertype_to_npindex(int ethertype)
315{
316 switch (ethertype) {
317 case ETH_P_IP:
318 return NP_IP;
319 case ETH_P_IPV6:
320 return NP_IPV6;
321 case ETH_P_IPX:
322 return NP_IPX;
323 case ETH_P_PPPTALK:
324 case ETH_P_ATALK:
325 return NP_AT;
326 case ETH_P_MPLS_UC:
327 return NP_MPLS_UC;
328 case ETH_P_MPLS_MC:
329 return NP_MPLS_MC;
330 }
331 return -1;
332}
333
334/* Translates an NP index into an ethertype */
335static const int npindex_to_ethertype[NUM_NP] = {
336 ETH_P_IP,
337 ETH_P_IPV6,
338 ETH_P_IPX,
339 ETH_P_PPPTALK,
340 ETH_P_MPLS_UC,
341 ETH_P_MPLS_MC,
342};
343
344/*
345 * Locking shorthand.
346 */
347#define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
348#define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
349#define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
350#define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
351#define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
352 ppp_recv_lock(ppp); } while (0)
353#define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
354 ppp_xmit_unlock(ppp); } while (0)
355
356/*
357 * /dev/ppp device routines.
358 * The /dev/ppp device is used by pppd to control the ppp unit.
359 * It supports the read, write, ioctl and poll functions.
360 * Open instances of /dev/ppp can be in one of three states:
361 * unattached, attached to a ppp unit, or attached to a ppp channel.
362 */
363static int ppp_open(struct inode *inode, struct file *file)
364{
f2b9857e 365 cycle_kernel_lock();
1da177e4
LT		 366 /*
367 * This could (should?) be enforced by the permissions on /dev/ppp.
368 */
369 if (!capable(CAP_NET_ADMIN))
370 return -EPERM;
371 return 0;
372}
373
f3ff8a4d 374static int ppp_release(struct inode *unused, struct file *file)
1da177e4
LT		 375{
376 struct ppp_file *pf = file->private_data;
377 struct ppp *ppp;
378
cd228d54 379 if (pf) {
1da177e4
LT		 380 file->private_data = NULL;
381 if (pf->kind == INTERFACE) {
382 ppp = PF_TO_PPP(pf);
383 if (file == ppp->owner)
384 ppp_shutdown_interface(ppp);
385 }
386 if (atomic_dec_and_test(&pf->refcnt)) {
387 switch (pf->kind) {
388 case INTERFACE:
389 ppp_destroy_interface(PF_TO_PPP(pf));
390 break;
391 case CHANNEL:
392 ppp_destroy_channel(PF_TO_CHANNEL(pf));
393 break;
394 }
395 }
396 }
397 return 0;
398}
399
400static ssize_t ppp_read(struct file *file, char __user *buf,
401 size_t count, loff_t *ppos)
402{
403 struct ppp_file *pf = file->private_data;
404 DECLARE_WAITQUEUE(wait, current);
405 ssize_t ret;
406 struct sk_buff *skb = NULL;
19937d04 407 struct iovec iov;
1da177e4
LT		 408
409 ret = count;
410
cd228d54 411 if (!pf)
1da177e4
LT		 412 return -ENXIO;
413 add_wait_queue(&pf->rwait, &wait);
414 for (;;) {
415 set_current_state(TASK_INTERRUPTIBLE);
416 skb = skb_dequeue(&pf->rq);
417 if (skb)
418 break;
419 ret = 0;
420 if (pf->dead)
421 break;
422 if (pf->kind == INTERFACE) {
423 /*
424 * Return 0 (EOF) on an interface that has no
425 * channels connected, unless it is looping
426 * network traffic (demand mode).
427 */
428 struct ppp *ppp = PF_TO_PPP(pf);
8e95a202
JP		 429 if (ppp->n_channels == 0 &&
430 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
1da177e4
LT		 431 break;
432 }
433 ret = -EAGAIN;
434 if (file->f_flags & O_NONBLOCK)
435 break;
436 ret = -ERESTARTSYS;
437 if (signal_pending(current))
438 break;
439 schedule();
440 }
441 set_current_state(TASK_RUNNING);
442 remove_wait_queue(&pf->rwait, &wait);
443
cd228d54 444 if (!skb)
1da177e4
LT		 445 goto out;
446
447 ret = -EOVERFLOW;
448 if (skb->len > count)
449 goto outf;
450 ret = -EFAULT;
19937d04
SA		 451 iov.iov_base = buf;
452 iov.iov_len = count;
453 if (skb_copy_datagram_iovec(skb, 0, &iov, skb->len))
1da177e4
LT		 454 goto outf;
455 ret = skb->len;
456
457 outf:
458 kfree_skb(skb);
459 out:
460 return ret;
461}
462
463static ssize_t ppp_write(struct file *file, const char __user *buf,
464 size_t count, loff_t *ppos)
465{
466 struct ppp_file *pf = file->private_data;
467 struct sk_buff *skb;
468 ssize_t ret;
469
cd228d54 470 if (!pf)
1da177e4
LT		 471 return -ENXIO;
472 ret = -ENOMEM;
473 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
cd228d54 474 if (!skb)
1da177e4
LT		 475 goto out;
476 skb_reserve(skb, pf->hdrlen);
477 ret = -EFAULT;
478 if (copy_from_user(skb_put(skb, count), buf, count)) {
479 kfree_skb(skb);
480 goto out;
481 }
482
483 skb_queue_tail(&pf->xq, skb);
484
485 switch (pf->kind) {
486 case INTERFACE:
487 ppp_xmit_process(PF_TO_PPP(pf));
488 break;
489 case CHANNEL:
490 ppp_channel_push(PF_TO_CHANNEL(pf));
491 break;
492 }
493
494 ret = count;
495
496 out:
497 return ret;
498}
499
500/* No kernel lock - fine */
501static unsigned int ppp_poll(struct file *file, poll_table *wait)
502{
503 struct ppp_file *pf = file->private_data;
504 unsigned int mask;
505
cd228d54 506 if (!pf)
1da177e4
LT		 507 return 0;
508 poll_wait(file, &pf->rwait, wait);
509 mask = POLLOUT | POLLWRNORM;
cd228d54 510 if (skb_peek(&pf->rq))
1da177e4
LT		 511 mask |= POLLIN | POLLRDNORM;
512 if (pf->dead)
513 mask |= POLLHUP;
514 else if (pf->kind == INTERFACE) {
515 /* see comment in ppp_read */
516 struct ppp *ppp = PF_TO_PPP(pf);
8e95a202
JP		 517 if (ppp->n_channels == 0 &&
518 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
1da177e4
LT		 519 mask |= POLLIN | POLLRDNORM;
520 }
521
522 return mask;
523}
524
525#ifdef CONFIG_PPP_FILTER
526static int get_filter(void __user *arg, struct sock_filter **p)
527{
528 struct sock_fprog uprog;
529 struct sock_filter *code = NULL;
530 int len, err;
531
532 if (copy_from_user(&uprog, arg, sizeof(uprog)))
533 return -EFAULT;
534
1da177e4
LT		 535 if (!uprog.len) {
536 *p = NULL;
537 return 0;
538 }
539
540 len = uprog.len * sizeof(struct sock_filter);
b23d00e9
JL		 541 code = memdup_user(uprog.filter, len);
542 if (IS_ERR(code))
543 return PTR_ERR(code);
1da177e4
LT		 544
545 err = sk_chk_filter(code, uprog.len);
546 if (err) {
547 kfree(code);
548 return err;
549 }
550
551 *p = code;
552 return uprog.len;
553}
554#endif /* CONFIG_PPP_FILTER */
555
f3ff8a4d 556static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1da177e4
LT		 557{
558 struct ppp_file *pf = file->private_data;
559 struct ppp *ppp;
560 int err = -EFAULT, val, val2, i;
561 struct ppp_idle idle;
562 struct npioctl npi;
563 int unit, cflags;
564 struct slcompress *vj;
565 void __user *argp = (void __user *)arg;
566 int __user *p = argp;
567
cd228d54 568 if (!pf)
273ec51d
CG		 569 return ppp_unattached_ioctl(current->nsproxy->net_ns,
570 pf, file, cmd, arg);
1da177e4
LT		 571
572 if (cmd == PPPIOCDETACH) {
573 /*
574 * We have to be careful here... if the file descriptor
575 * has been dup'd, we could have another process in the
576 * middle of a poll using the same file *, so we had
577 * better not free the interface data structures -
578 * instead we fail the ioctl. Even in this case, we
579 * shut down the interface if we are the owner of it.
580 * Actually, we should get rid of PPPIOCDETACH, userland
581 * (i.e. pppd) could achieve the same effect by closing
582 * this fd and reopening /dev/ppp.
583 */
584 err = -EINVAL;
f3ff8a4d 585 lock_kernel();
1da177e4
LT		 586 if (pf->kind == INTERFACE) {
587 ppp = PF_TO_PPP(pf);
588 if (file == ppp->owner)
589 ppp_shutdown_interface(ppp);
590 }
516e0cc5 591 if (atomic_long_read(&file->f_count) <= 2) {
f3ff8a4d 592 ppp_release(NULL, file);
1da177e4
LT		 593 err = 0;
594 } else
516e0cc5
AV		 595 printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%ld\n",
596 atomic_long_read(&file->f_count));
f3ff8a4d 597 unlock_kernel();
1da177e4
LT		 598 return err;
599 }
600
601 if (pf->kind == CHANNEL) {
f3ff8a4d 602 struct channel *pch;
1da177e4
LT		 603 struct ppp_channel *chan;
604
f3ff8a4d
AC		 605 lock_kernel();
606 pch = PF_TO_CHANNEL(pf);
607
1da177e4
LT		 608 switch (cmd) {
609 case PPPIOCCONNECT:
610 if (get_user(unit, p))
611 break;
612 err = ppp_connect_channel(pch, unit);
613 break;
614
615 case PPPIOCDISCONN:
616 err = ppp_disconnect_channel(pch);
617 break;
618
619 default:
620 down_read(&pch->chan_sem);
621 chan = pch->chan;
622 err = -ENOTTY;
623 if (chan && chan->ops->ioctl)
624 err = chan->ops->ioctl(chan, cmd, arg);
625 up_read(&pch->chan_sem);
626 }
f3ff8a4d 627 unlock_kernel();
1da177e4
LT		 628 return err;
629 }
630
631 if (pf->kind != INTERFACE) {
632 /* can't happen */
633 printk(KERN_ERR "PPP: not interface or channel??\n");
634 return -EINVAL;
635 }
636
f3ff8a4d 637 lock_kernel();
1da177e4
LT		 638 ppp = PF_TO_PPP(pf);
639 switch (cmd) {
640 case PPPIOCSMRU:
641 if (get_user(val, p))
642 break;
643 ppp->mru = val;
644 err = 0;
645 break;
646
647 case PPPIOCSFLAGS:
648 if (get_user(val, p))
649 break;
650 ppp_lock(ppp);
651 cflags = ppp->flags & ~val;
652 ppp->flags = val & SC_FLAG_BITS;
653 ppp_unlock(ppp);
654 if (cflags & SC_CCP_OPEN)
655 ppp_ccp_closed(ppp);
656 err = 0;
657 break;
658
659 case PPPIOCGFLAGS:
660 val = ppp->flags | ppp->xstate | ppp->rstate;
661 if (put_user(val, p))
662 break;
663 err = 0;
664 break;
665
666 case PPPIOCSCOMPRESS:
667 err = ppp_set_compress(ppp, arg);
668 break;
669
670 case PPPIOCGUNIT:
671 if (put_user(ppp->file.index, p))
672 break;
673 err = 0;
674 break;
675
676 case PPPIOCSDEBUG:
677 if (get_user(val, p))
678 break;
679 ppp->debug = val;
680 err = 0;
681 break;
682
683 case PPPIOCGDEBUG:
684 if (put_user(ppp->debug, p))
685 break;
686 err = 0;
687 break;
688
689 case PPPIOCGIDLE:
690 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
691 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
692 if (copy_to_user(argp, &idle, sizeof(idle)))
693 break;
694 err = 0;
695 break;
696
697 case PPPIOCSMAXCID:
698 if (get_user(val, p))
699 break;
700 val2 = 15;
701 if ((val >> 16) != 0) {
702 val2 = val >> 16;
703 val &= 0xffff;
704 }
705 vj = slhc_init(val2+1, val+1);
cd228d54 706 if (!vj) {
1da177e4
LT		 707 printk(KERN_ERR "PPP: no memory (VJ compressor)\n");
708 err = -ENOMEM;
709 break;
710 }
711 ppp_lock(ppp);
cd228d54 712 if (ppp->vj)
1da177e4
LT		 713 slhc_free(ppp->vj);
714 ppp->vj = vj;
715 ppp_unlock(ppp);
716 err = 0;
717 break;
718
719 case PPPIOCGNPMODE:
720 case PPPIOCSNPMODE:
721 if (copy_from_user(&npi, argp, sizeof(npi)))
722 break;
723 err = proto_to_npindex(npi.protocol);
724 if (err < 0)
725 break;
726 i = err;
727 if (cmd == PPPIOCGNPMODE) {
728 err = -EFAULT;
729 npi.mode = ppp->npmode[i];
730 if (copy_to_user(argp, &npi, sizeof(npi)))
731 break;
732 } else {
733 ppp->npmode[i] = npi.mode;
734 /* we may be able to transmit more packets now (??) */
735 netif_wake_queue(ppp->dev);
736 }
737 err = 0;
738 break;
739
740#ifdef CONFIG_PPP_FILTER
741 case PPPIOCSPASS:
742 {
743 struct sock_filter *code;
744 err = get_filter(argp, &code);
745 if (err >= 0) {
746 ppp_lock(ppp);
747 kfree(ppp->pass_filter);
748 ppp->pass_filter = code;
749 ppp->pass_len = err;
750 ppp_unlock(ppp);
751 err = 0;
752 }
753 break;
754 }
755 case PPPIOCSACTIVE:
756 {
757 struct sock_filter *code;
758 err = get_filter(argp, &code);
759 if (err >= 0) {
760 ppp_lock(ppp);
761 kfree(ppp->active_filter);
762 ppp->active_filter = code;
763 ppp->active_len = err;
764 ppp_unlock(ppp);
765 err = 0;
766 }
767 break;
768 }
769#endif /* CONFIG_PPP_FILTER */
770
771#ifdef CONFIG_PPP_MULTILINK
772 case PPPIOCSMRRU:
773 if (get_user(val, p))
774 break;
775 ppp_recv_lock(ppp);
776 ppp->mrru = val;
777 ppp_recv_unlock(ppp);
778 err = 0;
779 break;
780#endif /* CONFIG_PPP_MULTILINK */
781
782 default:
783 err = -ENOTTY;
784 }
f3ff8a4d 785 unlock_kernel();
1da177e4
LT		 786 return err;
787}
788
273ec51d
CG		 789static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
790 struct file *file, unsigned int cmd, unsigned long arg)
1da177e4
LT		 791{
792 int unit, err = -EFAULT;
793 struct ppp *ppp;
794 struct channel *chan;
273ec51d 795 struct ppp_net *pn;
1da177e4
LT		 796 int __user *p = (int __user *)arg;
797
f3ff8a4d 798 lock_kernel();
1da177e4
LT		 799 switch (cmd) {
800 case PPPIOCNEWUNIT:
801 /* Create a new ppp unit */
802 if (get_user(unit, p))
803 break;
273ec51d 804 ppp = ppp_create_interface(net, unit, &err);
cd228d54 805 if (!ppp)
1da177e4
LT		 806 break;
807 file->private_data = &ppp->file;
808 ppp->owner = file;
809 err = -EFAULT;
810 if (put_user(ppp->file.index, p))
811 break;
812 err = 0;
813 break;
814
815 case PPPIOCATTACH:
816 /* Attach to an existing ppp unit */
817 if (get_user(unit, p))
818 break;
1da177e4 819 err = -ENXIO;
273ec51d
CG		 820 pn = ppp_pernet(net);
821 mutex_lock(&pn->all_ppp_mutex);
822 ppp = ppp_find_unit(pn, unit);
cd228d54 823 if (ppp) {
1da177e4
LT		 824 atomic_inc(&ppp->file.refcnt);
825 file->private_data = &ppp->file;
826 err = 0;
827 }
273ec51d 828 mutex_unlock(&pn->all_ppp_mutex);
1da177e4
LT		 829 break;
830
831 case PPPIOCATTCHAN:
832 if (get_user(unit, p))
833 break;
1da177e4 834 err = -ENXIO;
273ec51d
CG		 835 pn = ppp_pernet(net);
836 spin_lock_bh(&pn->all_channels_lock);
837 chan = ppp_find_channel(pn, unit);
cd228d54 838 if (chan) {
1da177e4
LT		 839 atomic_inc(&chan->file.refcnt);
840 file->private_data = &chan->file;
841 err = 0;
842 }
273ec51d 843 spin_unlock_bh(&pn->all_channels_lock);
1da177e4
LT		 844 break;
845
846 default:
847 err = -ENOTTY;
848 }
f3ff8a4d 849 unlock_kernel();
1da177e4
LT		 850 return err;
851}
852
d54b1fdb 853static const struct file_operations ppp_device_fops = {
1da177e4
LT		 854 .owner = THIS_MODULE,
855 .read = ppp_read,
856 .write = ppp_write,
857 .poll = ppp_poll,
f3ff8a4d 858 .unlocked_ioctl = ppp_ioctl,
1da177e4
LT		 859 .open = ppp_open,
860 .release = ppp_release
861};
862
273ec51d
CG		 863static __net_init int ppp_init_net(struct net *net)
864{
741a6fa2 865 struct ppp_net *pn = net_generic(net, ppp_net_id);
273ec51d
CG		 866
867 idr_init(&pn->units_idr);
868 mutex_init(&pn->all_ppp_mutex);
869
870 INIT_LIST_HEAD(&pn->all_channels);
871 INIT_LIST_HEAD(&pn->new_channels);
872
873 spin_lock_init(&pn->all_channels_lock);
874
273ec51d
CG		 875 return 0;
876}
877
878static __net_exit void ppp_exit_net(struct net *net)
879{
741a6fa2 880 struct ppp_net *pn = net_generic(net, ppp_net_id);
273ec51d 881
273ec51d 882 idr_destroy(&pn->units_idr);
273ec51d
CG		 883}
884
0012985d 885static struct pernet_operations ppp_net_ops = {
273ec51d
CG		 886 .init = ppp_init_net,
887 .exit = ppp_exit_net,
741a6fa2
EB		 888 .id = &ppp_net_id,
889 .size = sizeof(struct ppp_net),
273ec51d
CG		 890};
891
1da177e4
LT		 892#define PPP_MAJOR 108
893
894/* Called at boot time if ppp is compiled into the kernel,
895 or at module load time (from init_module) if compiled as a module. */
896static int __init ppp_init(void)
897{
898 int err;
899
900 printk(KERN_INFO "PPP generic driver version " PPP_VERSION "\n");
273ec51d 901
741a6fa2 902 err = register_pernet_device(&ppp_net_ops);
273ec51d
CG		 903 if (err) {
904 printk(KERN_ERR "failed to register PPP pernet device (%d)\n", err);
905 goto out;
1da177e4
LT		 906 }
907
273ec51d
CG		 908 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
909 if (err) {
1da177e4 910 printk(KERN_ERR "failed to register PPP device (%d)\n", err);
273ec51d
CG		 911 goto out_net;
912 }
913
914 ppp_class = class_create(THIS_MODULE, "ppp");
915 if (IS_ERR(ppp_class)) {
916 err = PTR_ERR(ppp_class);
917 goto out_chrdev;
918 }
919
920 /* not a big deal if we fail here :-) */
921 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
922
923 return 0;
1da177e4 924
1da177e4
LT		 925out_chrdev:
926 unregister_chrdev(PPP_MAJOR, "ppp");
273ec51d 927out_net:
741a6fa2 928 unregister_pernet_device(&ppp_net_ops);
273ec51d
CG		 929out:
930 return err;
1da177e4
LT		 931}
932
933/*
934 * Network interface unit routines.
935 */
424efe9c 936static netdev_tx_t
1da177e4
LT		 937ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
938{
c8019bf3 939 struct ppp *ppp = netdev_priv(dev);
1da177e4
LT		 940 int npi, proto;
941 unsigned char *pp;
942
943 npi = ethertype_to_npindex(ntohs(skb->protocol));
944 if (npi < 0)
945 goto outf;
946
947 /* Drop, accept or reject the packet */
948 switch (ppp->npmode[npi]) {
949 case NPMODE_PASS:
950 break;
951 case NPMODE_QUEUE:
952 /* it would be nice to have a way to tell the network
953 system to queue this one up for later. */
954 goto outf;
955 case NPMODE_DROP:
956 case NPMODE_ERROR:
957 goto outf;
958 }
959
960 /* Put the 2-byte PPP protocol number on the front,
961 making sure there is room for the address and control fields. */
7b797d5b
HX		 962 if (skb_cow_head(skb, PPP_HDRLEN))
963 goto outf;
964
1da177e4
LT		 965 pp = skb_push(skb, 2);
966 proto = npindex_to_proto[npi];
967 pp[0] = proto >> 8;
968 pp[1] = proto;
969
970 netif_stop_queue(dev);
971 skb_queue_tail(&ppp->file.xq, skb);
972 ppp_xmit_process(ppp);
6ed10654 973 return NETDEV_TX_OK;
1da177e4
LT		 974
975 outf:
976 kfree_skb(skb);
6ceffd47 977 ++dev->stats.tx_dropped;
6ed10654 978 return NETDEV_TX_OK;
1da177e4
LT		 979}
980
1da177e4
LT		 981static int
982ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
983{
c8019bf3 984 struct ppp *ppp = netdev_priv(dev);
1da177e4
LT		 985 int err = -EFAULT;
986 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
987 struct ppp_stats stats;
988 struct ppp_comp_stats cstats;
989 char *vers;
990
991 switch (cmd) {
992 case SIOCGPPPSTATS:
993 ppp_get_stats(ppp, &stats);
994 if (copy_to_user(addr, &stats, sizeof(stats)))
995 break;
996 err = 0;
997 break;
998
999 case SIOCGPPPCSTATS:
1000 memset(&cstats, 0, sizeof(cstats));
cd228d54 1001 if (ppp->xc_state)
1da177e4 1002 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
cd228d54 1003 if (ppp->rc_state)
1da177e4
LT		 1004 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
1005 if (copy_to_user(addr, &cstats, sizeof(cstats)))
1006 break;
1007 err = 0;
1008 break;
1009
1010 case SIOCGPPPVER:
1011 vers = PPP_VERSION;
1012 if (copy_to_user(addr, vers, strlen(vers) + 1))
1013 break;
1014 err = 0;
1015 break;
1016
1017 default:
1018 err = -EINVAL;
1019 }
1020
1021 return err;
1022}
1023
52256cfc 1024static const struct net_device_ops ppp_netdev_ops = {
00829823
SH		 1025 .ndo_start_xmit = ppp_start_xmit,
1026 .ndo_do_ioctl = ppp_net_ioctl,
52256cfc
SH		 1027};
1028
1da177e4
LT		 1029static void ppp_setup(struct net_device *dev)
1030{
52256cfc 1031 dev->netdev_ops = &ppp_netdev_ops;
1da177e4
LT		 1032 dev->hard_header_len = PPP_HDRLEN;
1033 dev->mtu = PPP_MTU;
1034 dev->addr_len = 0;
1035 dev->tx_queue_len = 3;
1036 dev->type = ARPHRD_PPP;
1037 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
273ec51d 1038 dev->features |= NETIF_F_NETNS_LOCAL;
8b2d850d 1039 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1da177e4
LT		 1040}
1041
1042/*
1043 * Transmit-side routines.
1044 */
1045
1046/*
1047 * Called to do any work queued up on the transmit side
1048 * that can now be done.
1049 */
1050static void
1051ppp_xmit_process(struct ppp *ppp)
1052{
1053 struct sk_buff *skb;
1054
1055 ppp_xmit_lock(ppp);
739840d5 1056 if (!ppp->closing) {
1da177e4 1057 ppp_push(ppp);
8e95a202
JP		 1058 while (!ppp->xmit_pending &&
1059 (skb = skb_dequeue(&ppp->file.xq)))
1da177e4
LT		 1060 ppp_send_frame(ppp, skb);
1061 /* If there's no work left to do, tell the core net
1062 code that we can accept some more. */
cd228d54 1063 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1da177e4
LT		 1064 netif_wake_queue(ppp->dev);
1065 }
1066 ppp_xmit_unlock(ppp);
1067}
1068
b3f9b92a
MD		 1069static inline struct sk_buff *
1070pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1071{
1072 struct sk_buff *new_skb;
1073 int len;
1074 int new_skb_size = ppp->dev->mtu +
1075 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1076 int compressor_skb_size = ppp->dev->mtu +
1077 ppp->xcomp->comp_extra + PPP_HDRLEN;
1078 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1079 if (!new_skb) {
1080 if (net_ratelimit())
1081 printk(KERN_ERR "PPP: no memory (comp pkt)\n");
1082 return NULL;
1083 }
1084 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1085 skb_reserve(new_skb,
1086 ppp->dev->hard_header_len - PPP_HDRLEN);
1087
1088 /* compressor still expects A/C bytes in hdr */
1089 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1090 new_skb->data, skb->len + 2,
1091 compressor_skb_size);
1092 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1093 kfree_skb(skb);
1094 skb = new_skb;
1095 skb_put(skb, len);
1096 skb_pull(skb, 2); /* pull off A/C bytes */
1097 } else if (len == 0) {
1098 /* didn't compress, or CCP not up yet */
1099 kfree_skb(new_skb);
1100 new_skb = skb;
1101 } else {
1102 /*
1103 * (len < 0)
1104 * MPPE requires that we do not send unencrypted
1105 * frames. The compressor will return -1 if we
1106 * should drop the frame. We cannot simply test
1107 * the compress_proto because MPPE and MPPC share
1108 * the same number.
1109 */
1110 if (net_ratelimit())
1111 printk(KERN_ERR "ppp: compressor dropped pkt\n");
1112 kfree_skb(skb);
1113 kfree_skb(new_skb);
1114 new_skb = NULL;
1115 }
1116 return new_skb;
1117}
1118
1da177e4
LT		 1119/*
1120 * Compress and send a frame.
1121 * The caller should have locked the xmit path,
1122 * and xmit_pending should be 0.
1123 */
1124static void
1125ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1126{
1127 int proto = PPP_PROTO(skb);
1128 struct sk_buff *new_skb;
1129 int len;
1130 unsigned char *cp;
1131
1132 if (proto < 0x8000) {
1133#ifdef CONFIG_PPP_FILTER
1134 /* check if we should pass this packet */
1135 /* the filter instructions are constructed assuming
1136 a four-byte PPP header on each packet */
1137 *skb_push(skb, 2) = 1;
8e95a202
JP		 1138 if (ppp->pass_filter &&
1139 sk_run_filter(skb, ppp->pass_filter,
1140 ppp->pass_len) == 0) {
1da177e4
LT		 1141 if (ppp->debug & 1)
1142 printk(KERN_DEBUG "PPP: outbound frame not passed\n");
1143 kfree_skb(skb);
1144 return;
1145 }
1146 /* if this packet passes the active filter, record the time */
8e95a202
JP		 1147 if (!(ppp->active_filter &&
1148 sk_run_filter(skb, ppp->active_filter,
1149 ppp->active_len) == 0))
1da177e4
LT		 1150 ppp->last_xmit = jiffies;
1151 skb_pull(skb, 2);
1152#else
1153 /* for data packets, record the time */
1154 ppp->last_xmit = jiffies;
1155#endif /* CONFIG_PPP_FILTER */
1156 }
1157
8c0469cd
PZ		 1158 ++ppp->dev->stats.tx_packets;
1159 ppp->dev->stats.tx_bytes += skb->len - 2;
1da177e4
LT		 1160
1161 switch (proto) {
1162 case PPP_IP:
cd228d54 1163 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1da177e4
LT		 1164 break;
1165 /* try to do VJ TCP header compression */
1166 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1167 GFP_ATOMIC);
cd228d54 1168 if (!new_skb) {
1da177e4
LT		 1169 printk(KERN_ERR "PPP: no memory (VJ comp pkt)\n");
1170 goto drop;
1171 }
1172 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1173 cp = skb->data + 2;
1174 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1175 new_skb->data + 2, &cp,
1176 !(ppp->flags & SC_NO_TCP_CCID));
1177 if (cp == skb->data + 2) {
1178 /* didn't compress */
1179 kfree_skb(new_skb);
1180 } else {
1181 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1182 proto = PPP_VJC_COMP;
1183 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1184 } else {
1185 proto = PPP_VJC_UNCOMP;
1186 cp[0] = skb->data[2];
1187 }
1188 kfree_skb(skb);
1189 skb = new_skb;
1190 cp = skb_put(skb, len + 2);
1191 cp[0] = 0;
1192 cp[1] = proto;
1193 }
1194 break;
1195
1196 case PPP_CCP:
1197 /* peek at outbound CCP frames */
1198 ppp_ccp_peek(ppp, skb, 0);
1199 break;
1200 }
1201
1202 /* try to do packet compression */
8e95a202
JP		 1203 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state &&
1204 proto != PPP_LCP && proto != PPP_CCP) {
b3f9b92a
MD		 1205 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1206 if (net_ratelimit())
1207 printk(KERN_ERR "ppp: compression required but down - pkt dropped.\n");
1da177e4
LT		 1208 goto drop;
1209 }
b3f9b92a
MD		 1210 skb = pad_compress_skb(ppp, skb);
1211 if (!skb)
1212 goto drop;
1da177e4
LT		 1213 }
1214
1215 /*
1216 * If we are waiting for traffic (demand dialling),
1217 * queue it up for pppd to receive.
1218 */
1219 if (ppp->flags & SC_LOOP_TRAFFIC) {
1220 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1221 goto drop;
1222 skb_queue_tail(&ppp->file.rq, skb);
1223 wake_up_interruptible(&ppp->file.rwait);
1224 return;
1225 }
1226
1227 ppp->xmit_pending = skb;
1228 ppp_push(ppp);
1229 return;
1230
1231 drop:
1d2f8c95 1232 kfree_skb(skb);
8c0469cd 1233 ++ppp->dev->stats.tx_errors;
1da177e4
LT		 1234}
1235
1236/*
1237 * Try to send the frame in xmit_pending.
1238 * The caller should have the xmit path locked.
1239 */
1240static void
1241ppp_push(struct ppp *ppp)
1242{
1243 struct list_head *list;
1244 struct channel *pch;
1245 struct sk_buff *skb = ppp->xmit_pending;
1246
cd228d54 1247 if (!skb)
1da177e4
LT		 1248 return;
1249
1250 list = &ppp->channels;
1251 if (list_empty(list)) {
1252 /* nowhere to send the packet, just drop it */
1253 ppp->xmit_pending = NULL;
1254 kfree_skb(skb);
1255 return;
1256 }
1257
1258 if ((ppp->flags & SC_MULTILINK) == 0) {
1259 /* not doing multilink: send it down the first channel */
1260 list = list->next;
1261 pch = list_entry(list, struct channel, clist);
1262
1263 spin_lock_bh(&pch->downl);
1264 if (pch->chan) {
1265 if (pch->chan->ops->start_xmit(pch->chan, skb))
1266 ppp->xmit_pending = NULL;
1267 } else {
1268 /* channel got unregistered */
1269 kfree_skb(skb);
1270 ppp->xmit_pending = NULL;
1271 }
1272 spin_unlock_bh(&pch->downl);
1273 return;
1274 }
1275
1276#ifdef CONFIG_PPP_MULTILINK
1277 /* Multilink: fragment the packet over as many links
1278 as can take the packet at the moment. */
1279 if (!ppp_mp_explode(ppp, skb))
1280 return;
1281#endif /* CONFIG_PPP_MULTILINK */
1282
1283 ppp->xmit_pending = NULL;
1284 kfree_skb(skb);
1285}
1286
1287#ifdef CONFIG_PPP_MULTILINK
1288/*
1289 * Divide a packet to be transmitted into fragments and
1290 * send them out the individual links.
1291 */
1292static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1293{
fa44a73c
LS		 1294 int len, totlen;
1295 int i, bits, hdrlen, mtu;
1296 int flen;
1297 int navail, nfree, nzero;
1298 int nbigger;
1299 int totspeed;
1300 int totfree;
1da177e4
LT		 1301 unsigned char *p, *q;
1302 struct list_head *list;
1303 struct channel *pch;
1304 struct sk_buff *frag;
1305 struct ppp_channel *chan;
1306
9c705260 1307 totspeed = 0; /*total bitrate of the bundle*/
fa44a73c
LS		 1308 nfree = 0; /* # channels which have no packet already queued */
1309 navail = 0; /* total # of usable channels (not deregistered) */
1310 nzero = 0; /* number of channels with zero speed associated*/
1311 totfree = 0; /*total # of channels available and
9c705260
GP		 1312 *having no queued packets before
1313 *starting the fragmentation*/
1314
1da177e4 1315 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
fa44a73c
LS		 1316 i = 0;
1317 list_for_each_entry(pch, &ppp->channels, clist) {
516cd15f 1318 navail += pch->avail = (pch->chan != NULL);
9c705260 1319 pch->speed = pch->chan->speed;
fa44a73c 1320 if (pch->avail) {
b03efcfb 1321 if (skb_queue_empty(&pch->file.xq) ||
fa44a73c 1322 !pch->had_frag) {
9c705260
GP		 1323 if (pch->speed == 0)
1324 nzero++;
1325 else
1326 totspeed += pch->speed;
1327
1328 pch->avail = 2;
1329 ++nfree;
1330 ++totfree;
1331 }
fa44a73c
LS		 1332 if (!pch->had_frag && i < ppp->nxchan)
1333 ppp->nxchan = i;
1da177e4 1334 }
516cd15f 1335 ++i;
1da177e4 1336 }
516cd15f 1337 /*
fa44a73c
LS		 1338 * Don't start sending this packet unless at least half of
1339 * the channels are free. This gives much better TCP
1340 * performance if we have a lot of channels.
516cd15f 1341 */
fa44a73c
LS		 1342 if (nfree == 0 || nfree < navail / 2)
1343 return 0; /* can't take now, leave it in xmit_pending */
1da177e4
LT		 1344
1345 /* Do protocol field compression (XXX this should be optional) */
fa44a73c
LS		 1346 p = skb->data;
1347 len = skb->len;
1da177e4
LT		 1348 if (*p == 0) {
1349 ++p;
1350 --len;
1351 }
1352
9c705260 1353 totlen = len;
fa44a73c 1354 nbigger = len % nfree;
9c705260 1355
fa44a73c
LS		 1356 /* skip to the channel after the one we last used
1357 and start at that one */
81616c5a 1358 list = &ppp->channels;
fa44a73c 1359 for (i = 0; i < ppp->nxchan; ++i) {
1da177e4 1360 list = list->next;
fa44a73c
LS		 1361 if (list == &ppp->channels) {
1362 i = 0;
1da177e4
LT		 1363 break;
1364 }
1365 }
1366
fa44a73c 1367 /* create a fragment for each channel */
1da177e4 1368 bits = B;
fa44a73c 1369 while (len > 0) {
1da177e4 1370 list = list->next;
fa44a73c
LS		 1371 if (list == &ppp->channels) {
1372 i = 0;
1da177e4
LT		 1373 continue;
1374 }
fa44a73c 1375 pch = list_entry(list, struct channel, clist);
1da177e4
LT		 1376 ++i;
1377 if (!pch->avail)
1378 continue;
1379
516cd15f 1380 /*
fa44a73c
LS		 1381 * Skip this channel if it has a fragment pending already and
1382 * we haven't given a fragment to all of the free channels.
516cd15f
PM		 1383 */
1384 if (pch->avail == 1) {
fa44a73c 1385 if (nfree > 0)
516cd15f
PM		 1386 continue;
1387 } else {
516cd15f
PM		 1388 pch->avail = 1;
1389 }
1390
1da177e4
LT		 1391 /* check the channel's mtu and whether it is still attached. */
1392 spin_lock_bh(&pch->downl);
516cd15f 1393 if (pch->chan == NULL) {
fa44a73c 1394 /* can't use this channel, it's being deregistered */
9c705260
GP		 1395 if (pch->speed == 0)
1396 nzero--;
1397 else
fa44a73c 1398 totspeed -= pch->speed;
9c705260 1399
1da177e4
LT		 1400 spin_unlock_bh(&pch->downl);
1401 pch->avail = 0;
9c705260
GP		 1402 totlen = len;
1403 totfree--;
1404 nfree--;
fa44a73c 1405 if (--navail == 0)
1da177e4
LT		 1406 break;
1407 continue;
1408 }
1409
1410 /*
9c705260 1411 *if the channel speed is not set divide
fa44a73c 1412 *the packet evenly among the free channels;
9c705260
GP		 1413 *otherwise divide it according to the speed
1414 *of the channel we are going to transmit on
1415 */
886f9fe6 1416 flen = len;
a53a8b56
BM		 1417 if (nfree > 0) {
1418 if (pch->speed == 0) {
536e00e5 1419 flen = len/nfree;
a53a8b56
BM		 1420 if (nbigger > 0) {
1421 flen++;
1422 nbigger--;
1423 }
1424 } else {
1425 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
1426 ((totspeed*totfree)/pch->speed)) - hdrlen;
1427 if (nbigger > 0) {
1428 flen += ((totfree - nzero)*pch->speed)/totspeed;
1429 nbigger -= ((totfree - nzero)*pch->speed)/
9c705260 1430 totspeed;
a53a8b56 1431 }
9c705260 1432 }
a53a8b56 1433 nfree--;
9c705260 1434 }
9c705260
GP		 1435
1436 /*
fa44a73c
LS		 1437 *check if we are on the last channel or
1438 *we exceded the lenght of the data to
9c705260
GP		 1439 *fragment
1440 */
a53a8b56 1441 if ((nfree <= 0) || (flen > len))
9c705260
GP		 1442 flen = len;
1443 /*
1444 *it is not worth to tx on slow channels:
1445 *in that case from the resulting flen according to the
1446 *above formula will be equal or less than zero.
1447 *Skip the channel in this case
1da177e4 1448 */
fa44a73c 1449 if (flen <= 0) {
9c705260
GP		 1450 pch->avail = 2;
1451 spin_unlock_bh(&pch->downl);
1452 continue;
1453 }
1454
fa44a73c
LS		 1455 mtu = pch->chan->mtu - hdrlen;
1456 if (mtu < 4)
1457 mtu = 4;
516cd15f
PM		 1458 if (flen > mtu)
1459 flen = mtu;
fa44a73c
LS		 1460 if (flen == len)
1461 bits |= E;
1462 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
cd228d54 1463 if (!frag)
516cd15f 1464 goto noskb;
fa44a73c 1465 q = skb_put(frag, flen + hdrlen);
516cd15f 1466
fa44a73c 1467 /* make the MP header */
516cd15f
PM		 1468 q[0] = PPP_MP >> 8;
1469 q[1] = PPP_MP;
1470 if (ppp->flags & SC_MP_XSHORTSEQ) {
fa44a73c 1471 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
516cd15f
PM		 1472 q[3] = ppp->nxseq;
1473 } else {
1474 q[2] = bits;
1475 q[3] = ppp->nxseq >> 16;
1476 q[4] = ppp->nxseq >> 8;
1477 q[5] = ppp->nxseq;
1da177e4 1478 }
516cd15f 1479
9c705260 1480 memcpy(q + hdrlen, p, flen);
516cd15f
PM		 1481
1482 /* try to send it down the channel */
1483 chan = pch->chan;
fa44a73c 1484 if (!skb_queue_empty(&pch->file.xq) ||
9c705260 1485 !chan->ops->start_xmit(chan, frag))
516cd15f 1486 skb_queue_tail(&pch->file.xq, frag);
fa44a73c 1487 pch->had_frag = 1;
516cd15f 1488 p += flen;
fa44a73c 1489 len -= flen;
516cd15f
PM		 1490 ++ppp->nxseq;
1491 bits = 0;
1da177e4 1492 spin_unlock_bh(&pch->downl);
516cd15f 1493 }
fa44a73c 1494 ppp->nxchan = i;
1da177e4
LT		 1495
1496 return 1;
1497
1498 noskb:
1499 spin_unlock_bh(&pch->downl);
1500 if (ppp->debug & 1)
fa44a73c 1501 printk(KERN_ERR "PPP: no memory (fragment)\n");
8c0469cd 1502 ++ppp->dev->stats.tx_errors;
1da177e4
LT		 1503 ++ppp->nxseq;
1504 return 1; /* abandon the frame */
1505}
1506#endif /* CONFIG_PPP_MULTILINK */
1507
1508/*
1509 * Try to send data out on a channel.
1510 */
1511static void
1512ppp_channel_push(struct channel *pch)
1513{
1514 struct sk_buff *skb;
1515 struct ppp *ppp;
1516
1517 spin_lock_bh(&pch->downl);
cd228d54 1518 if (pch->chan) {
b03efcfb 1519 while (!skb_queue_empty(&pch->file.xq)) {
1da177e4
LT		 1520 skb = skb_dequeue(&pch->file.xq);
1521 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1522 /* put the packet back and try again later */
1523 skb_queue_head(&pch->file.xq, skb);
1524 break;
1525 }
1526 }
1527 } else {
1528 /* channel got deregistered */
1529 skb_queue_purge(&pch->file.xq);
1530 }
1531 spin_unlock_bh(&pch->downl);
1532 /* see if there is anything from the attached unit to be sent */
b03efcfb 1533 if (skb_queue_empty(&pch->file.xq)) {
1da177e4
LT		 1534 read_lock_bh(&pch->upl);
1535 ppp = pch->ppp;
cd228d54 1536 if (ppp)
1da177e4
LT		 1537 ppp_xmit_process(ppp);
1538 read_unlock_bh(&pch->upl);
1539 }
1540}
1541
1542/*
1543 * Receive-side routines.
1544 */
1545
1546/* misuse a few fields of the skb for MP reconstruction */
1547#define sequence priority
1548#define BEbits cb[0]
1549
1550static inline void
1551ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1552{
1553 ppp_recv_lock(ppp);
739840d5 1554 if (!ppp->closing)
1da177e4
LT		 1555 ppp_receive_frame(ppp, skb, pch);
1556 else
1557 kfree_skb(skb);
1558 ppp_recv_unlock(ppp);
1559}
1560
1561void
1562ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1563{
1564 struct channel *pch = chan->ppp;
1565 int proto;
1566
ea8420e9 1567 if (!pch) {
1da177e4
LT		 1568 kfree_skb(skb);
1569 return;
1570 }
516cd15f 1571
1da177e4 1572 read_lock_bh(&pch->upl);
ea8420e9
SA		 1573 if (!pskb_may_pull(skb, 2)) {
1574 kfree_skb(skb);
1575 if (pch->ppp) {
1576 ++pch->ppp->dev->stats.rx_length_errors;
1577 ppp_receive_error(pch->ppp);
1578 }
1579 goto done;
1580 }
1581
1582 proto = PPP_PROTO(skb);
cd228d54 1583 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1da177e4
LT		 1584 /* put it on the channel queue */
1585 skb_queue_tail(&pch->file.rq, skb);
1586 /* drop old frames if queue too long */
8e95a202
JP		 1587 while (pch->file.rq.qlen > PPP_MAX_RQLEN &&
1588 (skb = skb_dequeue(&pch->file.rq)))
1da177e4
LT		 1589 kfree_skb(skb);
1590 wake_up_interruptible(&pch->file.rwait);
1591 } else {
1592 ppp_do_recv(pch->ppp, skb, pch);
1593 }
ea8420e9
SA		 1594
1595done:
1da177e4
LT		 1596 read_unlock_bh(&pch->upl);
1597}
1598
1599/* Put a 0-length skb in the receive queue as an error indication */
1600void
1601ppp_input_error(struct ppp_channel *chan, int code)
1602{
1603 struct channel *pch = chan->ppp;
1604 struct sk_buff *skb;
1605
cd228d54 1606 if (!pch)
1da177e4
LT		 1607 return;
1608
1609 read_lock_bh(&pch->upl);
cd228d54 1610 if (pch->ppp) {
1da177e4 1611 skb = alloc_skb(0, GFP_ATOMIC);
cd228d54 1612 if (skb) {
1da177e4
LT		 1613 skb->len = 0; /* probably unnecessary */
1614 skb->cb[0] = code;
1615 ppp_do_recv(pch->ppp, skb, pch);
1616 }
1617 }
1618 read_unlock_bh(&pch->upl);
1619}
1620
1621/*
1622 * We come in here to process a received frame.
1623 * The receive side of the ppp unit is locked.
1624 */
1625static void
1626ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1627{
ea8420e9
SA		 1628 /* note: a 0-length skb is used as an error indication */
1629 if (skb->len > 0) {
1da177e4
LT		 1630#ifdef CONFIG_PPP_MULTILINK
1631 /* XXX do channel-level decompression here */
1632 if (PPP_PROTO(skb) == PPP_MP)
1633 ppp_receive_mp_frame(ppp, skb, pch);
1634 else
1635#endif /* CONFIG_PPP_MULTILINK */
1636 ppp_receive_nonmp_frame(ppp, skb);
ea8420e9
SA		 1637 } else {
1638 kfree_skb(skb);
1639 ppp_receive_error(ppp);
1da177e4 1640 }
1da177e4
LT		 1641}
1642
1643static void
1644ppp_receive_error(struct ppp *ppp)
1645{
8c0469cd 1646 ++ppp->dev->stats.rx_errors;
cd228d54 1647 if (ppp->vj)
1da177e4
LT		 1648 slhc_toss(ppp->vj);
1649}
1650
1651static void
1652ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1653{
1654 struct sk_buff *ns;
1655 int proto, len, npi;
1656
1657 /*
1658 * Decompress the frame, if compressed.
1659 * Note that some decompressors need to see uncompressed frames
1660 * that come in as well as compressed frames.
1661 */
8e95a202
JP		 1662 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) &&
1663 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1da177e4
LT		 1664 skb = ppp_decompress_frame(ppp, skb);
1665
b3f9b92a
MD		 1666 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1667 goto err;
1668
1da177e4
LT		 1669 proto = PPP_PROTO(skb);
1670 switch (proto) {
1671 case PPP_VJC_COMP:
1672 /* decompress VJ compressed packets */
cd228d54 1673 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1da177e4
LT		 1674 goto err;
1675
2a38b775 1676 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1da177e4
LT		 1677 /* copy to a new sk_buff with more tailroom */
1678 ns = dev_alloc_skb(skb->len + 128);
cd228d54 1679 if (!ns) {
1da177e4
LT		 1680 printk(KERN_ERR"PPP: no memory (VJ decomp)\n");
1681 goto err;
1682 }
1683 skb_reserve(ns, 2);
1684 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1685 kfree_skb(skb);
1686 skb = ns;
1687 }
e3f749c4
HX		 1688 else
1689 skb->ip_summed = CHECKSUM_NONE;
1da177e4
LT		 1690
1691 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1692 if (len <= 0) {
1693 printk(KERN_DEBUG "PPP: VJ decompression error\n");
1694 goto err;
1695 }
1696 len += 2;
1697 if (len > skb->len)
1698 skb_put(skb, len - skb->len);
1699 else if (len < skb->len)
1700 skb_trim(skb, len);
1701 proto = PPP_IP;
1702 break;
1703
1704 case PPP_VJC_UNCOMP:
cd228d54 1705 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1da177e4 1706 goto err;
6aa20a22 1707
1da177e4
LT		 1708 /* Until we fix the decompressor need to make sure
1709 * data portion is linear.
1710 */
6aa20a22 1711 if (!pskb_may_pull(skb, skb->len))
1da177e4
LT		 1712 goto err;
1713
1714 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1715 printk(KERN_ERR "PPP: VJ uncompressed error\n");
1716 goto err;
1717 }
1718 proto = PPP_IP;
1719 break;
1720
1721 case PPP_CCP:
1722 ppp_ccp_peek(ppp, skb, 1);
1723 break;
1724 }
1725
8c0469cd
PZ		 1726 ++ppp->dev->stats.rx_packets;
1727 ppp->dev->stats.rx_bytes += skb->len - 2;
1da177e4
LT		 1728
1729 npi = proto_to_npindex(proto);
1730 if (npi < 0) {
1731 /* control or unknown frame - pass it to pppd */
1732 skb_queue_tail(&ppp->file.rq, skb);
1733 /* limit queue length by dropping old frames */
8e95a202
JP		 1734 while (ppp->file.rq.qlen > PPP_MAX_RQLEN &&
1735 (skb = skb_dequeue(&ppp->file.rq)))
1da177e4
LT		 1736 kfree_skb(skb);
1737 /* wake up any process polling or blocking on read */
1738 wake_up_interruptible(&ppp->file.rwait);
1739
1740 } else {
1741 /* network protocol frame - give it to the kernel */
1742
1743#ifdef CONFIG_PPP_FILTER
1744 /* check if the packet passes the pass and active filters */
1745 /* the filter instructions are constructed assuming
1746 a four-byte PPP header on each packet */
2a38b775
HX		 1747 if (ppp->pass_filter || ppp->active_filter) {
1748 if (skb_cloned(skb) &&
1749 pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
1750 goto err;
1751
1752 *skb_push(skb, 2) = 0;
8e95a202
JP		 1753 if (ppp->pass_filter &&
1754 sk_run_filter(skb, ppp->pass_filter,
1755 ppp->pass_len) == 0) {
2a38b775
HX		 1756 if (ppp->debug & 1)
1757 printk(KERN_DEBUG "PPP: inbound frame "
1758 "not passed\n");
1759 kfree_skb(skb);
1760 return;
1761 }
8e95a202
JP		 1762 if (!(ppp->active_filter &&
1763 sk_run_filter(skb, ppp->active_filter,
1764 ppp->active_len) == 0))
2a38b775
HX		 1765 ppp->last_recv = jiffies;
1766 __skb_pull(skb, 2);
1767 } else
1da177e4 1768#endif /* CONFIG_PPP_FILTER */
2a38b775 1769 ppp->last_recv = jiffies;
1da177e4 1770
8e95a202
JP		 1771 if ((ppp->dev->flags & IFF_UP) == 0 ||
1772 ppp->npmode[npi] != NPMODE_PASS) {
1da177e4
LT		 1773 kfree_skb(skb);
1774 } else {
cbb042f9
HX		 1775 /* chop off protocol */
1776 skb_pull_rcsum(skb, 2);
1da177e4
LT		 1777 skb->dev = ppp->dev;
1778 skb->protocol = htons(npindex_to_ethertype[npi]);
459a98ed 1779 skb_reset_mac_header(skb);
1da177e4 1780 netif_rx(skb);
1da177e4
LT		 1781 }
1782 }
1783 return;
1784
1785 err:
1786 kfree_skb(skb);
1787 ppp_receive_error(ppp);
1788}
1789
1790static struct sk_buff *
1791ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1792{
1793 int proto = PPP_PROTO(skb);
1794 struct sk_buff *ns;
1795 int len;
1796
1797 /* Until we fix all the decompressor's need to make sure
1798 * data portion is linear.
1799 */
1800 if (!pskb_may_pull(skb, skb->len))
1801 goto err;
1802
1803 if (proto == PPP_COMP) {
4b2a8fb3
KS		 1804 int obuff_size;
1805
1806 switch(ppp->rcomp->compress_proto) {
1807 case CI_MPPE:
1808 obuff_size = ppp->mru + PPP_HDRLEN + 1;
1809 break;
1810 default:
1811 obuff_size = ppp->mru + PPP_HDRLEN;
1812 break;
1813 }
1814
1815 ns = dev_alloc_skb(obuff_size);
cd228d54 1816 if (!ns) {
1da177e4
LT		 1817 printk(KERN_ERR "ppp_decompress_frame: no memory\n");
1818 goto err;
1819 }
1820 /* the decompressor still expects the A/C bytes in the hdr */
1821 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
06c7af56 1822 skb->len + 2, ns->data, obuff_size);
1da177e4
LT		 1823 if (len < 0) {
1824 /* Pass the compressed frame to pppd as an
1825 error indication. */
1826 if (len == DECOMP_FATALERROR)
1827 ppp->rstate |= SC_DC_FERROR;
1828 kfree_skb(ns);
1829 goto err;
1830 }
1831
1832 kfree_skb(skb);
1833 skb = ns;
1834 skb_put(skb, len);
1835 skb_pull(skb, 2); /* pull off the A/C bytes */
1836
1837 } else {
1838 /* Uncompressed frame - pass to decompressor so it
1839 can update its dictionary if necessary. */
1840 if (ppp->rcomp->incomp)
1841 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1842 skb->len + 2);
1843 }
1844
1845 return skb;
1846
1847 err:
1848 ppp->rstate |= SC_DC_ERROR;
1849 ppp_receive_error(ppp);
1850 return skb;
1851}
1852
1853#ifdef CONFIG_PPP_MULTILINK
1854/*
1855 * Receive a multilink frame.
1856 * We put it on the reconstruction queue and then pull off
1857 * as many completed frames as we can.
1858 */
1859static void
1860ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1861{
1862 u32 mask, seq;
81616c5a 1863 struct channel *ch;
1da177e4
LT		 1864 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1865
2a38b775 1866 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
1da177e4
LT		 1867 goto err; /* no good, throw it away */
1868
1869 /* Decode sequence number and begin/end bits */
1870 if (ppp->flags & SC_MP_SHORTSEQ) {
1871 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1872 mask = 0xfff;
1873 } else {
1874 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1875 mask = 0xffffff;
1876 }
1877 skb->BEbits = skb->data[2];
1878 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
1879
1880 /*
1881 * Do protocol ID decompression on the first fragment of each packet.
1882 */
1883 if ((skb->BEbits & B) && (skb->data[0] & 1))
1884 *skb_push(skb, 1) = 0;
1885
1886 /*
1887 * Expand sequence number to 32 bits, making it as close
1888 * as possible to ppp->minseq.
1889 */
1890 seq |= ppp->minseq & ~mask;
1891 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
1892 seq += mask + 1;
1893 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
1894 seq -= mask + 1; /* should never happen */
1895 skb->sequence = seq;
1896 pch->lastseq = seq;
1897
1898 /*
1899 * If this packet comes before the next one we were expecting,
1900 * drop it.
1901 */
1902 if (seq_before(seq, ppp->nextseq)) {
1903 kfree_skb(skb);
8c0469cd 1904 ++ppp->dev->stats.rx_dropped;
1da177e4
LT		 1905 ppp_receive_error(ppp);
1906 return;
1907 }
1908
1909 /*
1910 * Reevaluate minseq, the minimum over all channels of the
1911 * last sequence number received on each channel. Because of
1912 * the increasing sequence number rule, we know that any fragment
1913 * before `minseq' which hasn't arrived is never going to arrive.
1914 * The list of channels can't change because we have the receive
1915 * side of the ppp unit locked.
1916 */
81616c5a 1917 list_for_each_entry(ch, &ppp->channels, clist) {
1da177e4
LT		 1918 if (seq_before(ch->lastseq, seq))
1919 seq = ch->lastseq;
1920 }
1921 if (seq_before(ppp->minseq, seq))
1922 ppp->minseq = seq;
1923
1924 /* Put the fragment on the reconstruction queue */
1925 ppp_mp_insert(ppp, skb);
1926
1927 /* If the queue is getting long, don't wait any longer for packets
1928 before the start of the queue. */
38ce7c73 1929 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
c6b20d94 1930 struct sk_buff *mskb = skb_peek(&ppp->mrq);
1931 if (seq_before(ppp->minseq, mskb->sequence))
1932 ppp->minseq = mskb->sequence;
38ce7c73 1933 }
1da177e4
LT		 1934
1935 /* Pull completed packets off the queue and receive them. */
82b3cc1a
BM		 1936 while ((skb = ppp_mp_reconstruct(ppp))) {
1937 if (pskb_may_pull(skb, 2))
1938 ppp_receive_nonmp_frame(ppp, skb);
1939 else {
1940 ++ppp->dev->stats.rx_length_errors;
1941 kfree_skb(skb);
1942 ppp_receive_error(ppp);
1943 }
1944 }
1da177e4
LT		 1945
1946 return;
1947
1948 err:
1949 kfree_skb(skb);
1950 ppp_receive_error(ppp);
1951}
1952
1953/*
1954 * Insert a fragment on the MP reconstruction queue.
1955 * The queue is ordered by increasing sequence number.
1956 */
1957static void
1958ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
1959{
1960 struct sk_buff *p;
1961 struct sk_buff_head *list = &ppp->mrq;
1962 u32 seq = skb->sequence;
1963
1964 /* N.B. we don't need to lock the list lock because we have the
1965 ppp unit receive-side lock. */
13c9821e 1966 skb_queue_walk(list, p) {
1da177e4
LT		 1967 if (seq_before(seq, p->sequence))
1968 break;
13c9821e 1969 }
43f59c89 1970 __skb_queue_before(list, p, skb);
1da177e4
LT		 1971}
1972
1973/*
1974 * Reconstruct a packet from the MP fragment queue.
1975 * We go through increasing sequence numbers until we find a
1976 * complete packet, or we get to the sequence number for a fragment
1977 * which hasn't arrived but might still do so.
1978 */
3c582b30 1979static struct sk_buff *
1da177e4
LT		 1980ppp_mp_reconstruct(struct ppp *ppp)
1981{
1982 u32 seq = ppp->nextseq;
1983 u32 minseq = ppp->minseq;
1984 struct sk_buff_head *list = &ppp->mrq;
1985 struct sk_buff *p, *next;
1986 struct sk_buff *head, *tail;
1987 struct sk_buff *skb = NULL;
1988 int lost = 0, len = 0;
1989
1990 if (ppp->mrru == 0) /* do nothing until mrru is set */
1991 return NULL;
1992 head = list->next;
1993 tail = NULL;
1994 for (p = head; p != (struct sk_buff *) list; p = next) {
1995 next = p->next;
1996 if (seq_before(p->sequence, seq)) {
1997 /* this can't happen, anyway ignore the skb */
1998 printk(KERN_ERR "ppp_mp_reconstruct bad seq %u < %u\n",
1999 p->sequence, seq);
2000 head = next;
2001 continue;
2002 }
2003 if (p->sequence != seq) {
2004 /* Fragment `seq' is missing. If it is after
2005 minseq, it might arrive later, so stop here. */
2006 if (seq_after(seq, minseq))
2007 break;
2008 /* Fragment `seq' is lost, keep going. */
2009 lost = 1;
2010 seq = seq_before(minseq, p->sequence)?
2011 minseq + 1: p->sequence;
2012 next = p;
2013 continue;
2014 }
2015
2016 /*
2017 * At this point we know that all the fragments from
2018 * ppp->nextseq to seq are either present or lost.
2019 * Also, there are no complete packets in the queue
2020 * that have no missing fragments and end before this
2021 * fragment.
2022 */
2023
2024 /* B bit set indicates this fragment starts a packet */
2025 if (p->BEbits & B) {
2026 head = p;
2027 lost = 0;
2028 len = 0;
2029 }
2030
2031 len += p->len;
2032
2033 /* Got a complete packet yet? */
2034 if (lost == 0 && (p->BEbits & E) && (head->BEbits & B)) {
2035 if (len > ppp->mrru + 2) {
8c0469cd 2036 ++ppp->dev->stats.rx_length_errors;
1da177e4
LT		 2037 printk(KERN_DEBUG "PPP: reconstructed packet"
2038 " is too long (%d)\n", len);
2039 } else if (p == head) {
2040 /* fragment is complete packet - reuse skb */
2041 tail = p;
2042 skb = skb_get(p);
2043 break;
2044 } else if ((skb = dev_alloc_skb(len)) == NULL) {
8c0469cd 2045 ++ppp->dev->stats.rx_missed_errors;
1da177e4
LT		 2046 printk(KERN_DEBUG "PPP: no memory for "
2047 "reconstructed packet");
2048 } else {
2049 tail = p;
2050 break;
2051 }
2052 ppp->nextseq = seq + 1;
2053 }
2054
2055 /*
2056 * If this is the ending fragment of a packet,
2057 * and we haven't found a complete valid packet yet,
2058 * we can discard up to and including this fragment.
2059 */
2060 if (p->BEbits & E)
2061 head = next;
2062
2063 ++seq;
2064 }
2065
2066 /* If we have a complete packet, copy it all into one skb. */
2067 if (tail != NULL) {
2068 /* If we have discarded any fragments,
2069 signal a receive error. */
2070 if (head->sequence != ppp->nextseq) {
2071 if (ppp->debug & 1)
2072 printk(KERN_DEBUG " missed pkts %u..%u\n",
2073 ppp->nextseq, head->sequence-1);
8c0469cd 2074 ++ppp->dev->stats.rx_dropped;
1da177e4
LT		 2075 ppp_receive_error(ppp);
2076 }
2077
2078 if (head != tail)
2079 /* copy to a single skb */
2080 for (p = head; p != tail->next; p = p->next)
2081 skb_copy_bits(p, 0, skb_put(skb, p->len), p->len);
2082 ppp->nextseq = tail->sequence + 1;
2083 head = tail->next;
2084 }
2085
2086 /* Discard all the skbuffs that we have copied the data out of
2087 or that we can't use. */
2088 while ((p = list->next) != head) {
2089 __skb_unlink(p, list);
2090 kfree_skb(p);
2091 }
2092
2093 return skb;
2094}
2095#endif /* CONFIG_PPP_MULTILINK */
2096
2097/*
2098 * Channel interface.
2099 */
2100
273ec51d
CG		 2101/* Create a new, unattached ppp channel. */
2102int ppp_register_channel(struct ppp_channel *chan)
2103{
2104 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2105}
2106
2107/* Create a new, unattached ppp channel for specified net. */
2108int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
1da177e4
LT		 2109{
2110 struct channel *pch;
273ec51d 2111 struct ppp_net *pn;
1da177e4 2112
d4274b51 2113 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
cd228d54 2114 if (!pch)
1da177e4 2115 return -ENOMEM;
273ec51d
CG		 2116
2117 pn = ppp_pernet(net);
2118
1da177e4
LT		 2119 pch->ppp = NULL;
2120 pch->chan = chan;
273ec51d 2121 pch->chan_net = net;
1da177e4
LT		 2122 chan->ppp = pch;
2123 init_ppp_file(&pch->file, CHANNEL);
2124 pch->file.hdrlen = chan->hdrlen;
2125#ifdef CONFIG_PPP_MULTILINK
2126 pch->lastseq = -1;
2127#endif /* CONFIG_PPP_MULTILINK */
2128 init_rwsem(&pch->chan_sem);
2129 spin_lock_init(&pch->downl);
2130 rwlock_init(&pch->upl);
273ec51d
CG		 2131
2132 spin_lock_bh(&pn->all_channels_lock);
2133 pch->file.index = ++pn->last_channel_index;
2134 list_add(&pch->list, &pn->new_channels);
1da177e4 2135 atomic_inc(&channel_count);
273ec51d
CG		 2136 spin_unlock_bh(&pn->all_channels_lock);
2137
1da177e4
LT		 2138 return 0;
2139}
2140
2141/*
2142 * Return the index of a channel.
2143 */
2144int ppp_channel_index(struct ppp_channel *chan)
2145{
2146 struct channel *pch = chan->ppp;
2147
cd228d54 2148 if (pch)
1da177e4
LT		 2149 return pch->file.index;
2150 return -1;
2151}
2152
2153/*
2154 * Return the PPP unit number to which a channel is connected.
2155 */
2156int ppp_unit_number(struct ppp_channel *chan)
2157{
2158 struct channel *pch = chan->ppp;
2159 int unit = -1;
2160
cd228d54 2161 if (pch) {
1da177e4 2162 read_lock_bh(&pch->upl);
cd228d54 2163 if (pch->ppp)
1da177e4
LT		 2164 unit = pch->ppp->file.index;
2165 read_unlock_bh(&pch->upl);
2166 }
2167 return unit;
2168}
2169
63f96072
JC		 2170/*
2171 * Return the PPP device interface name of a channel.
2172 */
2173char *ppp_dev_name(struct ppp_channel *chan)
2174{
2175 struct channel *pch = chan->ppp;
2176 char *name = NULL;
2177
2178 if (pch) {
2179 read_lock_bh(&pch->upl);
2180 if (pch->ppp && pch->ppp->dev)
2181 name = pch->ppp->dev->name;
2182 read_unlock_bh(&pch->upl);
2183 }
2184 return name;
2185}
2186
2187
1da177e4
LT		 2188/*
2189 * Disconnect a channel from the generic layer.
2190 * This must be called in process context.
2191 */
2192void
2193ppp_unregister_channel(struct ppp_channel *chan)
2194{
2195 struct channel *pch = chan->ppp;
273ec51d 2196 struct ppp_net *pn;
1da177e4 2197
cd228d54 2198 if (!pch)
1da177e4 2199 return; /* should never happen */
273ec51d 2200
1da177e4
LT		 2201 chan->ppp = NULL;
2202
2203 /*
2204 * This ensures that we have returned from any calls into the
2205 * the channel's start_xmit or ioctl routine before we proceed.
2206 */
2207 down_write(&pch->chan_sem);
2208 spin_lock_bh(&pch->downl);
2209 pch->chan = NULL;
2210 spin_unlock_bh(&pch->downl);
2211 up_write(&pch->chan_sem);
2212 ppp_disconnect_channel(pch);
273ec51d
CG		 2213
2214 pn = ppp_pernet(pch->chan_net);
2215 spin_lock_bh(&pn->all_channels_lock);
1da177e4 2216 list_del(&pch->list);
273ec51d
CG		 2217 spin_unlock_bh(&pn->all_channels_lock);
2218
1da177e4
LT		 2219 pch->file.dead = 1;
2220 wake_up_interruptible(&pch->file.rwait);
2221 if (atomic_dec_and_test(&pch->file.refcnt))
2222 ppp_destroy_channel(pch);
2223}
2224
2225/*
2226 * Callback from a channel when it can accept more to transmit.
2227 * This should be called at BH/softirq level, not interrupt level.
2228 */
2229void
2230ppp_output_wakeup(struct ppp_channel *chan)
2231{
2232 struct channel *pch = chan->ppp;
2233
cd228d54 2234 if (!pch)
1da177e4
LT		 2235 return;
2236 ppp_channel_push(pch);
2237}
2238
2239/*
2240 * Compression control.
2241 */
2242
2243/* Process the PPPIOCSCOMPRESS ioctl. */
2244static int
2245ppp_set_compress(struct ppp *ppp, unsigned long arg)
2246{
2247 int err;
2248 struct compressor *cp, *ocomp;
2249 struct ppp_option_data data;
2250 void *state, *ostate;
2251 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2252
2253 err = -EFAULT;
8e95a202
JP		 2254 if (copy_from_user(&data, (void __user *) arg, sizeof(data)) ||
2255 (data.length <= CCP_MAX_OPTION_LENGTH &&
2256 copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
1da177e4
LT		 2257 goto out;
2258 err = -EINVAL;
8e95a202
JP		 2259 if (data.length > CCP_MAX_OPTION_LENGTH ||
2260 ccp_option[1] < 2 || ccp_option[1] > data.length)
1da177e4
LT		 2261 goto out;
2262
a65e5d78
JB		 2263 cp = try_then_request_module(
2264 find_compressor(ccp_option[0]),
2265 "ppp-compress-%d", ccp_option[0]);
cd228d54 2266 if (!cp)
1da177e4
LT		 2267 goto out;
2268
2269 err = -ENOBUFS;
2270 if (data.transmit) {
2271 state = cp->comp_alloc(ccp_option, data.length);
cd228d54 2272 if (state) {
1da177e4
LT		 2273 ppp_xmit_lock(ppp);
2274 ppp->xstate &= ~SC_COMP_RUN;
2275 ocomp = ppp->xcomp;
2276 ostate = ppp->xc_state;
2277 ppp->xcomp = cp;
2278 ppp->xc_state = state;
2279 ppp_xmit_unlock(ppp);
cd228d54 2280 if (ostate) {
1da177e4
LT		 2281 ocomp->comp_free(ostate);
2282 module_put(ocomp->owner);
2283 }
2284 err = 0;
2285 } else
2286 module_put(cp->owner);
2287
2288 } else {
2289 state = cp->decomp_alloc(ccp_option, data.length);
cd228d54 2290 if (state) {
1da177e4
LT		 2291 ppp_recv_lock(ppp);
2292 ppp->rstate &= ~SC_DECOMP_RUN;
2293 ocomp = ppp->rcomp;
2294 ostate = ppp->rc_state;
2295 ppp->rcomp = cp;
2296 ppp->rc_state = state;
2297 ppp_recv_unlock(ppp);
cd228d54 2298 if (ostate) {
1da177e4
LT		 2299 ocomp->decomp_free(ostate);
2300 module_put(ocomp->owner);
2301 }
2302 err = 0;
2303 } else
2304 module_put(cp->owner);
2305 }
2306
2307 out:
2308 return err;
2309}
2310
2311/*
2312 * Look at a CCP packet and update our state accordingly.
2313 * We assume the caller has the xmit or recv path locked.
2314 */
2315static void
2316ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2317{
2318 unsigned char *dp;
2319 int len;
2320
2321 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2322 return; /* no header */
2323 dp = skb->data + 2;
2324
2325 switch (CCP_CODE(dp)) {
2326 case CCP_CONFREQ:
2327
6aa20a22 2328 /* A ConfReq starts negotiation of compression
1da177e4
LT		 2329 * in one direction of transmission,
2330 * and hence brings it down...but which way?
2331 *
2332 * Remember:
2333 * A ConfReq indicates what the sender would like to receive
2334 */
2335 if(inbound)
2336 /* He is proposing what I should send */
2337 ppp->xstate &= ~SC_COMP_RUN;
6aa20a22 2338 else
1da177e4
LT		 2339 /* I am proposing to what he should send */
2340 ppp->rstate &= ~SC_DECOMP_RUN;
6aa20a22 2341
1da177e4 2342 break;
6aa20a22 2343
1da177e4
LT		 2344 case CCP_TERMREQ:
2345 case CCP_TERMACK:
2346 /*
6aa20a22 2347 * CCP is going down, both directions of transmission
1da177e4
LT		 2348 */
2349 ppp->rstate &= ~SC_DECOMP_RUN;
2350 ppp->xstate &= ~SC_COMP_RUN;
2351 break;
2352
2353 case CCP_CONFACK:
2354 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2355 break;
2356 len = CCP_LENGTH(dp);
2357 if (!pskb_may_pull(skb, len + 2))
2358 return; /* too short */
2359 dp += CCP_HDRLEN;
2360 len -= CCP_HDRLEN;
2361 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2362 break;
2363 if (inbound) {
2364 /* we will start receiving compressed packets */
cd228d54 2365 if (!ppp->rc_state)
1da177e4
LT		 2366 break;
2367 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2368 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2369 ppp->rstate |= SC_DECOMP_RUN;
2370 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2371 }
2372 } else {
2373 /* we will soon start sending compressed packets */
cd228d54 2374 if (!ppp->xc_state)
1da177e4
LT		 2375 break;
2376 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2377 ppp->file.index, 0, ppp->debug))
2378 ppp->xstate |= SC_COMP_RUN;
2379 }
2380 break;
2381
2382 case CCP_RESETACK:
2383 /* reset the [de]compressor */
2384 if ((ppp->flags & SC_CCP_UP) == 0)
2385 break;
2386 if (inbound) {
2387 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2388 ppp->rcomp->decomp_reset(ppp->rc_state);
2389 ppp->rstate &= ~SC_DC_ERROR;
2390 }
2391 } else {
2392 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2393 ppp->xcomp->comp_reset(ppp->xc_state);
2394 }
2395 break;
2396 }
2397}
2398
2399/* Free up compression resources. */
2400static void
2401ppp_ccp_closed(struct ppp *ppp)
2402{
2403 void *xstate, *rstate;
2404 struct compressor *xcomp, *rcomp;
2405
2406 ppp_lock(ppp);
2407 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2408 ppp->xstate = 0;
2409 xcomp = ppp->xcomp;
2410 xstate = ppp->xc_state;
2411 ppp->xc_state = NULL;
2412 ppp->rstate = 0;
2413 rcomp = ppp->rcomp;
2414 rstate = ppp->rc_state;
2415 ppp->rc_state = NULL;
2416 ppp_unlock(ppp);
2417
2418 if (xstate) {
2419 xcomp->comp_free(xstate);
2420 module_put(xcomp->owner);
2421 }
2422 if (rstate) {
2423 rcomp->decomp_free(rstate);
2424 module_put(rcomp->owner);
2425 }
2426}
2427
2428/* List of compressors. */
2429static LIST_HEAD(compressor_list);
2430static DEFINE_SPINLOCK(compressor_list_lock);
2431
2432struct compressor_entry {
2433 struct list_head list;
2434 struct compressor *comp;
2435};
2436
2437static struct compressor_entry *
2438find_comp_entry(int proto)
2439{
2440 struct compressor_entry *ce;
1da177e4 2441
81616c5a 2442 list_for_each_entry(ce, &compressor_list, list) {
1da177e4
LT		 2443 if (ce->comp->compress_proto == proto)
2444 return ce;
2445 }
2446 return NULL;
2447}
2448
2449/* Register a compressor */
2450int
2451ppp_register_compressor(struct compressor *cp)
2452{
2453 struct compressor_entry *ce;
2454 int ret;
2455 spin_lock(&compressor_list_lock);
2456 ret = -EEXIST;
cd228d54 2457 if (find_comp_entry(cp->compress_proto))
1da177e4
LT		 2458 goto out;
2459 ret = -ENOMEM;
2460 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
cd228d54 2461 if (!ce)
1da177e4
LT		 2462 goto out;
2463 ret = 0;
2464 ce->comp = cp;
2465 list_add(&ce->list, &compressor_list);
2466 out:
2467 spin_unlock(&compressor_list_lock);
2468 return ret;
2469}
2470
2471/* Unregister a compressor */
2472void
2473ppp_unregister_compressor(struct compressor *cp)
2474{
2475 struct compressor_entry *ce;
2476
2477 spin_lock(&compressor_list_lock);
2478 ce = find_comp_entry(cp->compress_proto);
cd228d54 2479 if (ce && ce->comp == cp) {
1da177e4
LT		 2480 list_del(&ce->list);
2481 kfree(ce);
2482 }
2483 spin_unlock(&compressor_list_lock);
2484}
2485
2486/* Find a compressor. */
2487static struct compressor *
2488find_compressor(int type)
2489{
2490 struct compressor_entry *ce;
2491 struct compressor *cp = NULL;
2492
2493 spin_lock(&compressor_list_lock);
2494 ce = find_comp_entry(type);
cd228d54 2495 if (ce) {
1da177e4
LT		 2496 cp = ce->comp;
2497 if (!try_module_get(cp->owner))
2498 cp = NULL;
2499 }
2500 spin_unlock(&compressor_list_lock);
2501 return cp;
2502}
2503
2504/*
2505 * Miscelleneous stuff.
2506 */
2507
2508static void
2509ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2510{
2511 struct slcompress *vj = ppp->vj;
2512
2513 memset(st, 0, sizeof(*st));
8c0469cd
PZ		 2514 st->p.ppp_ipackets = ppp->dev->stats.rx_packets;
2515 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2516 st->p.ppp_ibytes = ppp->dev->stats.rx_bytes;
2517 st->p.ppp_opackets = ppp->dev->stats.tx_packets;
2518 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2519 st->p.ppp_obytes = ppp->dev->stats.tx_bytes;
cd228d54 2520 if (!vj)
1da177e4
LT		 2521 return;
2522 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2523 st->vj.vjs_compressed = vj->sls_o_compressed;
2524 st->vj.vjs_searches = vj->sls_o_searches;
2525 st->vj.vjs_misses = vj->sls_o_misses;
2526 st->vj.vjs_errorin = vj->sls_i_error;
2527 st->vj.vjs_tossed = vj->sls_i_tossed;
2528 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2529 st->vj.vjs_compressedin = vj->sls_i_compressed;
2530}
2531
2532/*
2533 * Stuff for handling the lists of ppp units and channels
2534 * and for initialization.
2535 */
2536
2537/*
2538 * Create a new ppp interface unit. Fails if it can't allocate memory
2539 * or if there is already a unit with the requested number.
2540 * unit == -1 means allocate a new number.
2541 */
2542static struct ppp *
273ec51d 2543ppp_create_interface(struct net *net, int unit, int *retp)
1da177e4
LT		 2544{
2545 struct ppp *ppp;
273ec51d 2546 struct ppp_net *pn;
1da177e4
LT		 2547 struct net_device *dev = NULL;
2548 int ret = -ENOMEM;
2549 int i;
2550
c8019bf3 2551 dev = alloc_netdev(sizeof(struct ppp), "", ppp_setup);
1da177e4
LT		 2552 if (!dev)
2553 goto out1;
1da177e4 2554
273ec51d
CG		 2555 pn = ppp_pernet(net);
2556
c8019bf3
WC		 2557 ppp = netdev_priv(dev);
2558 ppp->dev = dev;
1da177e4
LT		 2559 ppp->mru = PPP_MRU;
2560 init_ppp_file(&ppp->file, INTERFACE);
2561 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2562 for (i = 0; i < NUM_NP; ++i)
2563 ppp->npmode[i] = NPMODE_PASS;
2564 INIT_LIST_HEAD(&ppp->channels);
2565 spin_lock_init(&ppp->rlock);
2566 spin_lock_init(&ppp->wlock);
2567#ifdef CONFIG_PPP_MULTILINK
2568 ppp->minseq = -1;
2569 skb_queue_head_init(&ppp->mrq);
2570#endif /* CONFIG_PPP_MULTILINK */
1da177e4 2571
273ec51d
CG		 2572 /*
2573 * drum roll: don't forget to set
2574 * the net device is belong to
2575 */
2576 dev_net_set(dev, net);
2577
1da177e4 2578 ret = -EEXIST;
273ec51d 2579 mutex_lock(&pn->all_ppp_mutex);
7a95d267
CG		 2580
2581 if (unit < 0) {
273ec51d 2582 unit = unit_get(&pn->units_idr, ppp);
7a95d267
CG		 2583 if (unit < 0) {
2584 *retp = unit;
2585 goto out2;
2586 }
2587 } else {
273ec51d 2588 if (unit_find(&pn->units_idr, unit))
7a95d267 2589 goto out2; /* unit already exists */
85997576
CG		 2590 /*
2591 * if caller need a specified unit number
2592 * lets try to satisfy him, otherwise --
2593 * he should better ask us for new unit number
2594 *
2595 * NOTE: yes I know that returning EEXIST it's not
2596 * fair but at least pppd will ask us to allocate
2597 * new unit in this case so user is happy :)
2598 */
273ec51d 2599 unit = unit_set(&pn->units_idr, ppp, unit);
85997576 2600 if (unit < 0)
7a95d267 2601 goto out2;
7a95d267 2602 }
1da177e4
LT		 2603
2604 /* Initialize the new ppp unit */
2605 ppp->file.index = unit;
2606 sprintf(dev->name, "ppp%d", unit);
2607
2608 ret = register_netdev(dev);
2609 if (ret != 0) {
273ec51d 2610 unit_put(&pn->units_idr, unit);
1da177e4
LT		 2611 printk(KERN_ERR "PPP: couldn't register device %s (%d)\n",
2612 dev->name, ret);
2613 goto out2;
2614 }
2615
273ec51d
CG		 2616 ppp->ppp_net = net;
2617
1da177e4 2618 atomic_inc(&ppp_unit_count);
273ec51d 2619 mutex_unlock(&pn->all_ppp_mutex);
7a95d267 2620
1da177e4
LT		 2621 *retp = 0;
2622 return ppp;
2623
2624out2:
273ec51d 2625 mutex_unlock(&pn->all_ppp_mutex);
1da177e4
LT		 2626 free_netdev(dev);
2627out1:
1da177e4
LT		 2628 *retp = ret;
2629 return NULL;
2630}
2631
2632/*
2633 * Initialize a ppp_file structure.
2634 */
2635static void
2636init_ppp_file(struct ppp_file *pf, int kind)
2637{
2638 pf->kind = kind;
2639 skb_queue_head_init(&pf->xq);
2640 skb_queue_head_init(&pf->rq);
2641 atomic_set(&pf->refcnt, 1);
2642 init_waitqueue_head(&pf->rwait);
2643}
2644
2645/*
2646 * Take down a ppp interface unit - called when the owning file
2647 * (the one that created the unit) is closed or detached.
2648 */
2649static void ppp_shutdown_interface(struct ppp *ppp)
2650{
273ec51d
CG		 2651 struct ppp_net *pn;
2652
2653 pn = ppp_pernet(ppp->ppp_net);
2654 mutex_lock(&pn->all_ppp_mutex);
2655
1da177e4 2656 /* This will call dev_close() for us. */
739840d5
JC		 2657 ppp_lock(ppp);
2658 if (!ppp->closing) {
2659 ppp->closing = 1;
2660 ppp_unlock(ppp);
2661 unregister_netdev(ppp->dev);
2662 } else
2663 ppp_unlock(ppp);
2664
273ec51d 2665 unit_put(&pn->units_idr, ppp->file.index);
1da177e4
LT		 2666 ppp->file.dead = 1;
2667 ppp->owner = NULL;
2668 wake_up_interruptible(&ppp->file.rwait);
273ec51d
CG		 2669
2670 mutex_unlock(&pn->all_ppp_mutex);
1da177e4
LT		 2671}
2672
2673/*
2674 * Free the memory used by a ppp unit. This is only called once
2675 * there are no channels connected to the unit and no file structs
2676 * that reference the unit.
2677 */
2678static void ppp_destroy_interface(struct ppp *ppp)
2679{
2680 atomic_dec(&ppp_unit_count);
2681
2682 if (!ppp->file.dead || ppp->n_channels) {
2683 /* "can't happen" */
2684 printk(KERN_ERR "ppp: destroying ppp struct %p but dead=%d "
2685 "n_channels=%d !\n", ppp, ppp->file.dead,
2686 ppp->n_channels);
2687 return;
2688 }
2689
2690 ppp_ccp_closed(ppp);
2691 if (ppp->vj) {
2692 slhc_free(ppp->vj);
2693 ppp->vj = NULL;
2694 }
2695 skb_queue_purge(&ppp->file.xq);
2696 skb_queue_purge(&ppp->file.rq);
2697#ifdef CONFIG_PPP_MULTILINK
2698 skb_queue_purge(&ppp->mrq);
2699#endif /* CONFIG_PPP_MULTILINK */
2700#ifdef CONFIG_PPP_FILTER
96edf83c
JJ		 2701 kfree(ppp->pass_filter);
2702 ppp->pass_filter = NULL;
2703 kfree(ppp->active_filter);
2704 ppp->active_filter = NULL;
1da177e4
LT		 2705#endif /* CONFIG_PPP_FILTER */
2706
1d2f8c95 2707 kfree_skb(ppp->xmit_pending);
165de5b7 2708
739840d5 2709 free_netdev(ppp->dev);
1da177e4
LT		 2710}
2711
2712/*
2713 * Locate an existing ppp unit.
8ed965d6 2714 * The caller should have locked the all_ppp_mutex.
1da177e4
LT		 2715 */
2716static struct ppp *
273ec51d 2717ppp_find_unit(struct ppp_net *pn, int unit)
1da177e4 2718{
273ec51d 2719 return unit_find(&pn->units_idr, unit);
1da177e4
LT		 2720}
2721
2722/*
2723 * Locate an existing ppp channel.
2724 * The caller should have locked the all_channels_lock.
2725 * First we look in the new_channels list, then in the
2726 * all_channels list. If found in the new_channels list,
2727 * we move it to the all_channels list. This is for speed
2728 * when we have a lot of channels in use.
2729 */
2730static struct channel *
273ec51d 2731ppp_find_channel(struct ppp_net *pn, int unit)
1da177e4
LT		 2732{
2733 struct channel *pch;
1da177e4 2734
273ec51d 2735 list_for_each_entry(pch, &pn->new_channels, list) {
1da177e4 2736 if (pch->file.index == unit) {
273ec51d 2737 list_move(&pch->list, &pn->all_channels);
1da177e4
LT		 2738 return pch;
2739 }
2740 }
273ec51d
CG		 2741
2742 list_for_each_entry(pch, &pn->all_channels, list) {
1da177e4
LT		 2743 if (pch->file.index == unit)
2744 return pch;
2745 }
273ec51d 2746
1da177e4
LT		 2747 return NULL;
2748}
2749
2750/*
2751 * Connect a PPP channel to a PPP interface unit.
2752 */
2753static int
2754ppp_connect_channel(struct channel *pch, int unit)
2755{
2756 struct ppp *ppp;
273ec51d 2757 struct ppp_net *pn;
1da177e4
LT		 2758 int ret = -ENXIO;
2759 int hdrlen;
2760
273ec51d
CG		 2761 pn = ppp_pernet(pch->chan_net);
2762
2763 mutex_lock(&pn->all_ppp_mutex);
2764 ppp = ppp_find_unit(pn, unit);
cd228d54 2765 if (!ppp)
1da177e4
LT		 2766 goto out;
2767 write_lock_bh(&pch->upl);
2768 ret = -EINVAL;
cd228d54 2769 if (pch->ppp)
1da177e4
LT		 2770 goto outl;
2771
2772 ppp_lock(ppp);
2773 if (pch->file.hdrlen > ppp->file.hdrlen)
2774 ppp->file.hdrlen = pch->file.hdrlen;
2775 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
739840d5 2776 if (hdrlen > ppp->dev->hard_header_len)
1da177e4
LT		 2777 ppp->dev->hard_header_len = hdrlen;
2778 list_add_tail(&pch->clist, &ppp->channels);
2779 ++ppp->n_channels;
2780 pch->ppp = ppp;
2781 atomic_inc(&ppp->file.refcnt);
2782 ppp_unlock(ppp);
2783 ret = 0;
2784
2785 outl:
2786 write_unlock_bh(&pch->upl);
2787 out:
273ec51d 2788 mutex_unlock(&pn->all_ppp_mutex);
1da177e4
LT		 2789 return ret;
2790}
2791
2792/*
2793 * Disconnect a channel from its ppp unit.
2794 */
2795static int
2796ppp_disconnect_channel(struct channel *pch)
2797{
2798 struct ppp *ppp;
2799 int err = -EINVAL;
2800
2801 write_lock_bh(&pch->upl);
2802 ppp = pch->ppp;
2803 pch->ppp = NULL;
2804 write_unlock_bh(&pch->upl);
cd228d54 2805 if (ppp) {
1da177e4
LT		 2806 /* remove it from the ppp unit's list */
2807 ppp_lock(ppp);
2808 list_del(&pch->clist);
2809 if (--ppp->n_channels == 0)
2810 wake_up_interruptible(&ppp->file.rwait);
2811 ppp_unlock(ppp);
2812 if (atomic_dec_and_test(&ppp->file.refcnt))
2813 ppp_destroy_interface(ppp);
2814 err = 0;
2815 }
2816 return err;
2817}
2818
2819/*
2820 * Free up the resources used by a ppp channel.
2821 */
2822static void ppp_destroy_channel(struct channel *pch)
2823{
2824 atomic_dec(&channel_count);
2825
2826 if (!pch->file.dead) {
2827 /* "can't happen" */
2828 printk(KERN_ERR "ppp: destroying undead channel %p !\n",
2829 pch);
2830 return;
2831 }
2832 skb_queue_purge(&pch->file.xq);
2833 skb_queue_purge(&pch->file.rq);
2834 kfree(pch);
2835}
2836
2837static void __exit ppp_cleanup(void)
2838{
2839 /* should never happen */
2840 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2841 printk(KERN_ERR "PPP: removing module but units remain!\n");
68fc4fab 2842 unregister_chrdev(PPP_MAJOR, "ppp");
9a6a2a5e 2843 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
56b22935 2844 class_destroy(ppp_class);
741a6fa2 2845 unregister_pernet_device(&ppp_net_ops);
1da177e4
LT		 2846}
2847
2848/*
7a95d267
CG		 2849 * Units handling. Caller must protect concurrent access
2850 * by holding all_ppp_mutex
1da177e4 2851 */
7a95d267 2852
85997576
CG		 2853/* associate pointer with specified number */
2854static int unit_set(struct idr *p, void *ptr, int n)
2855{
2856 int unit, err;
2857
2858again:
2859 if (!idr_pre_get(p, GFP_KERNEL)) {
2860 printk(KERN_ERR "PPP: No free memory for idr\n");
2861 return -ENOMEM;
2862 }
2863
2864 err = idr_get_new_above(p, ptr, n, &unit);
2865 if (err == -EAGAIN)
2866 goto again;
2867
2868 if (unit != n) {
2869 idr_remove(p, unit);
2870 return -EINVAL;
2871 }
2872
2873 return unit;
2874}
2875
7a95d267
CG		 2876/* get new free unit number and associate pointer with it */
2877static int unit_get(struct idr *p, void *ptr)
1da177e4 2878{
7a95d267 2879 int unit, err;
1da177e4 2880
7a95d267 2881again:
85997576
CG		 2882 if (!idr_pre_get(p, GFP_KERNEL)) {
2883 printk(KERN_ERR "PPP: No free memory for idr\n");
7a95d267 2884 return -ENOMEM;
1da177e4 2885 }
1da177e4 2886
7a95d267
CG		 2887 err = idr_get_new_above(p, ptr, 0, &unit);
2888 if (err == -EAGAIN)
2889 goto again;
1da177e4 2890
7a95d267 2891 return unit;
1da177e4
LT		 2892}
2893
7a95d267
CG		 2894/* put unit number back to a pool */
2895static void unit_put(struct idr *p, int n)
1da177e4 2896{
7a95d267 2897 idr_remove(p, n);
1da177e4
LT		 2898}
2899
7a95d267
CG		 2900/* get pointer associated with the number */
2901static void *unit_find(struct idr *p, int n)
1da177e4 2902{
7a95d267 2903 return idr_find(p, n);
1da177e4
LT		 2904}
2905
2906/* Module/initialization stuff */
2907
2908module_init(ppp_init);
2909module_exit(ppp_cleanup);
2910
273ec51d 2911EXPORT_SYMBOL(ppp_register_net_channel);
1da177e4
LT		 2912EXPORT_SYMBOL(ppp_register_channel);
2913EXPORT_SYMBOL(ppp_unregister_channel);
2914EXPORT_SYMBOL(ppp_channel_index);
2915EXPORT_SYMBOL(ppp_unit_number);
63f96072 2916EXPORT_SYMBOL(ppp_dev_name);
1da177e4
LT		 2917EXPORT_SYMBOL(ppp_input);
2918EXPORT_SYMBOL(ppp_input_error);
2919EXPORT_SYMBOL(ppp_output_wakeup);
2920EXPORT_SYMBOL(ppp_register_compressor);
2921EXPORT_SYMBOL(ppp_unregister_compressor);
2922MODULE_LICENSE("GPL");
578454ff
KS		 2923MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
2924MODULE_ALIAS("devname:ppp");
Clone of davem's net-next-2.6 tree