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irda: remove some pointless conditionals before kfree_skb()
[net-next-2.6.git] / drivers / net / ppp_generic.c
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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>
1da177e4
LT		 49#include <net/slhc_vj.h>
50#include <asm/atomic.h>
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 */
71#define MIN_FRAG_SIZE 64
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 */
170#endif /* CONFIG_PPP_MULTILINK */
171};
172
173/*
174 * SMP locking issues:
175 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
176 * list and the ppp.n_channels field, you need to take both locks
177 * before you modify them.
178 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
179 * channel.downl.
180 */
181
1da177e4 182static atomic_t ppp_unit_count = ATOMIC_INIT(0);
1da177e4
LT		 183static atomic_t channel_count = ATOMIC_INIT(0);
184
273ec51d 185/* per-net private data for this module */
d6781f2a 186static int ppp_net_id;
273ec51d
CG		 187struct ppp_net {
188 /* units to ppp mapping */
189 struct idr units_idr;
190
191 /*
192 * all_ppp_mutex protects the units_idr mapping.
193 * It also ensures that finding a ppp unit in the units_idr
194 * map and updating its file.refcnt field is atomic.
195 */
196 struct mutex all_ppp_mutex;
197
198 /* channels */
199 struct list_head all_channels;
200 struct list_head new_channels;
201 int last_channel_index;
202
203 /*
204 * all_channels_lock protects all_channels and
205 * last_channel_index, and the atomicity of find
206 * a channel and updating its file.refcnt field.
207 */
208 spinlock_t all_channels_lock;
209};
210
1da177e4
LT		 211/* Get the PPP protocol number from a skb */
212#define PPP_PROTO(skb) (((skb)->data[0] << 8) + (skb)->data[1])
213
214/* We limit the length of ppp->file.rq to this (arbitrary) value */
215#define PPP_MAX_RQLEN 32
216
217/*
218 * Maximum number of multilink fragments queued up.
219 * This has to be large enough to cope with the maximum latency of
220 * the slowest channel relative to the others. Strictly it should
221 * depend on the number of channels and their characteristics.
222 */
223#define PPP_MP_MAX_QLEN 128
224
225/* Multilink header bits. */
226#define B 0x80 /* this fragment begins a packet */
227#define E 0x40 /* this fragment ends a packet */
228
229/* Compare multilink sequence numbers (assumed to be 32 bits wide) */
230#define seq_before(a, b) ((s32)((a) - (b)) < 0)
231#define seq_after(a, b) ((s32)((a) - (b)) > 0)
232
233/* Prototypes. */
273ec51d
CG		 234static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
235 struct file *file, unsigned int cmd, unsigned long arg);
1da177e4
LT		 236static void ppp_xmit_process(struct ppp *ppp);
237static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
238static void ppp_push(struct ppp *ppp);
239static void ppp_channel_push(struct channel *pch);
240static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
241 struct channel *pch);
242static void ppp_receive_error(struct ppp *ppp);
243static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
244static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
245 struct sk_buff *skb);
246#ifdef CONFIG_PPP_MULTILINK
247static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
248 struct channel *pch);
249static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
250static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
251static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
252#endif /* CONFIG_PPP_MULTILINK */
253static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
254static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
255static void ppp_ccp_closed(struct ppp *ppp);
256static struct compressor *find_compressor(int type);
257static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
273ec51d 258static struct ppp *ppp_create_interface(struct net *net, int unit, int *retp);
1da177e4
LT		 259static void init_ppp_file(struct ppp_file *pf, int kind);
260static void ppp_shutdown_interface(struct ppp *ppp);
261static void ppp_destroy_interface(struct ppp *ppp);
273ec51d
CG		 262static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit);
263static struct channel *ppp_find_channel(struct ppp_net *pn, int unit);
1da177e4
LT		 264static int ppp_connect_channel(struct channel *pch, int unit);
265static int ppp_disconnect_channel(struct channel *pch);
266static void ppp_destroy_channel(struct channel *pch);
7a95d267 267static int unit_get(struct idr *p, void *ptr);
85997576 268static int unit_set(struct idr *p, void *ptr, int n);
7a95d267
CG		 269static void unit_put(struct idr *p, int n);
270static void *unit_find(struct idr *p, int n);
1da177e4 271
56b22935 272static struct class *ppp_class;
1da177e4 273
273ec51d
CG		 274/* per net-namespace data */
275static inline struct ppp_net *ppp_pernet(struct net *net)
276{
277 BUG_ON(!net);
278
279 return net_generic(net, ppp_net_id);
280}
281
1da177e4
LT		 282/* Translates a PPP protocol number to a NP index (NP == network protocol) */
283static inline int proto_to_npindex(int proto)
284{
285 switch (proto) {
286 case PPP_IP:
287 return NP_IP;
288 case PPP_IPV6:
289 return NP_IPV6;
290 case PPP_IPX:
291 return NP_IPX;
292 case PPP_AT:
293 return NP_AT;
294 case PPP_MPLS_UC:
295 return NP_MPLS_UC;
296 case PPP_MPLS_MC:
297 return NP_MPLS_MC;
298 }
299 return -EINVAL;
300}
301
302/* Translates an NP index into a PPP protocol number */
303static const int npindex_to_proto[NUM_NP] = {
304 PPP_IP,
305 PPP_IPV6,
306 PPP_IPX,
307 PPP_AT,
308 PPP_MPLS_UC,
309 PPP_MPLS_MC,
310};
6aa20a22 311
1da177e4
LT		 312/* Translates an ethertype into an NP index */
313static inline int ethertype_to_npindex(int ethertype)
314{
315 switch (ethertype) {
316 case ETH_P_IP:
317 return NP_IP;
318 case ETH_P_IPV6:
319 return NP_IPV6;
320 case ETH_P_IPX:
321 return NP_IPX;
322 case ETH_P_PPPTALK:
323 case ETH_P_ATALK:
324 return NP_AT;
325 case ETH_P_MPLS_UC:
326 return NP_MPLS_UC;
327 case ETH_P_MPLS_MC:
328 return NP_MPLS_MC;
329 }
330 return -1;
331}
332
333/* Translates an NP index into an ethertype */
334static const int npindex_to_ethertype[NUM_NP] = {
335 ETH_P_IP,
336 ETH_P_IPV6,
337 ETH_P_IPX,
338 ETH_P_PPPTALK,
339 ETH_P_MPLS_UC,
340 ETH_P_MPLS_MC,
341};
342
343/*
344 * Locking shorthand.
345 */
346#define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
347#define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
348#define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
349#define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
350#define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
351 ppp_recv_lock(ppp); } while (0)
352#define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
353 ppp_xmit_unlock(ppp); } while (0)
354
355/*
356 * /dev/ppp device routines.
357 * The /dev/ppp device is used by pppd to control the ppp unit.
358 * It supports the read, write, ioctl and poll functions.
359 * Open instances of /dev/ppp can be in one of three states:
360 * unattached, attached to a ppp unit, or attached to a ppp channel.
361 */
362static int ppp_open(struct inode *inode, struct file *file)
363{
f2b9857e 364 cycle_kernel_lock();
1da177e4
LT		 365 /*
366 * This could (should?) be enforced by the permissions on /dev/ppp.
367 */
368 if (!capable(CAP_NET_ADMIN))
369 return -EPERM;
370 return 0;
371}
372
f3ff8a4d 373static int ppp_release(struct inode *unused, struct file *file)
1da177e4
LT		 374{
375 struct ppp_file *pf = file->private_data;
376 struct ppp *ppp;
377
cd228d54 378 if (pf) {
1da177e4
LT		 379 file->private_data = NULL;
380 if (pf->kind == INTERFACE) {
381 ppp = PF_TO_PPP(pf);
382 if (file == ppp->owner)
383 ppp_shutdown_interface(ppp);
384 }
385 if (atomic_dec_and_test(&pf->refcnt)) {
386 switch (pf->kind) {
387 case INTERFACE:
388 ppp_destroy_interface(PF_TO_PPP(pf));
389 break;
390 case CHANNEL:
391 ppp_destroy_channel(PF_TO_CHANNEL(pf));
392 break;
393 }
394 }
395 }
396 return 0;
397}
398
399static ssize_t ppp_read(struct file *file, char __user *buf,
400 size_t count, loff_t *ppos)
401{
402 struct ppp_file *pf = file->private_data;
403 DECLARE_WAITQUEUE(wait, current);
404 ssize_t ret;
405 struct sk_buff *skb = NULL;
406
407 ret = count;
408
cd228d54 409 if (!pf)
1da177e4
LT		 410 return -ENXIO;
411 add_wait_queue(&pf->rwait, &wait);
412 for (;;) {
413 set_current_state(TASK_INTERRUPTIBLE);
414 skb = skb_dequeue(&pf->rq);
415 if (skb)
416 break;
417 ret = 0;
418 if (pf->dead)
419 break;
420 if (pf->kind == INTERFACE) {
421 /*
422 * Return 0 (EOF) on an interface that has no
423 * channels connected, unless it is looping
424 * network traffic (demand mode).
425 */
426 struct ppp *ppp = PF_TO_PPP(pf);
427 if (ppp->n_channels == 0
428 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
429 break;
430 }
431 ret = -EAGAIN;
432 if (file->f_flags & O_NONBLOCK)
433 break;
434 ret = -ERESTARTSYS;
435 if (signal_pending(current))
436 break;
437 schedule();
438 }
439 set_current_state(TASK_RUNNING);
440 remove_wait_queue(&pf->rwait, &wait);
441
cd228d54 442 if (!skb)
1da177e4
LT		 443 goto out;
444
445 ret = -EOVERFLOW;
446 if (skb->len > count)
447 goto outf;
448 ret = -EFAULT;
449 if (copy_to_user(buf, skb->data, skb->len))
450 goto outf;
451 ret = skb->len;
452
453 outf:
454 kfree_skb(skb);
455 out:
456 return ret;
457}
458
459static ssize_t ppp_write(struct file *file, const char __user *buf,
460 size_t count, loff_t *ppos)
461{
462 struct ppp_file *pf = file->private_data;
463 struct sk_buff *skb;
464 ssize_t ret;
465
cd228d54 466 if (!pf)
1da177e4
LT		 467 return -ENXIO;
468 ret = -ENOMEM;
469 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
cd228d54 470 if (!skb)
1da177e4
LT		 471 goto out;
472 skb_reserve(skb, pf->hdrlen);
473 ret = -EFAULT;
474 if (copy_from_user(skb_put(skb, count), buf, count)) {
475 kfree_skb(skb);
476 goto out;
477 }
478
479 skb_queue_tail(&pf->xq, skb);
480
481 switch (pf->kind) {
482 case INTERFACE:
483 ppp_xmit_process(PF_TO_PPP(pf));
484 break;
485 case CHANNEL:
486 ppp_channel_push(PF_TO_CHANNEL(pf));
487 break;
488 }
489
490 ret = count;
491
492 out:
493 return ret;
494}
495
496/* No kernel lock - fine */
497static unsigned int ppp_poll(struct file *file, poll_table *wait)
498{
499 struct ppp_file *pf = file->private_data;
500 unsigned int mask;
501
cd228d54 502 if (!pf)
1da177e4
LT		 503 return 0;
504 poll_wait(file, &pf->rwait, wait);
505 mask = POLLOUT | POLLWRNORM;
cd228d54 506 if (skb_peek(&pf->rq))
1da177e4
LT		 507 mask |= POLLIN | POLLRDNORM;
508 if (pf->dead)
509 mask |= POLLHUP;
510 else if (pf->kind == INTERFACE) {
511 /* see comment in ppp_read */
512 struct ppp *ppp = PF_TO_PPP(pf);
513 if (ppp->n_channels == 0
514 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
515 mask |= POLLIN | POLLRDNORM;
516 }
517
518 return mask;
519}
520
521#ifdef CONFIG_PPP_FILTER
522static int get_filter(void __user *arg, struct sock_filter **p)
523{
524 struct sock_fprog uprog;
525 struct sock_filter *code = NULL;
526 int len, err;
527
528 if (copy_from_user(&uprog, arg, sizeof(uprog)))
529 return -EFAULT;
530
1da177e4
LT		 531 if (!uprog.len) {
532 *p = NULL;
533 return 0;
534 }
535
536 len = uprog.len * sizeof(struct sock_filter);
537 code = kmalloc(len, GFP_KERNEL);
538 if (code == NULL)
539 return -ENOMEM;
540
541 if (copy_from_user(code, uprog.filter, len)) {
542 kfree(code);
543 return -EFAULT;
544 }
545
546 err = sk_chk_filter(code, uprog.len);
547 if (err) {
548 kfree(code);
549 return err;
550 }
551
552 *p = code;
553 return uprog.len;
554}
555#endif /* CONFIG_PPP_FILTER */
556
f3ff8a4d 557static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1da177e4
LT		 558{
559 struct ppp_file *pf = file->private_data;
560 struct ppp *ppp;
561 int err = -EFAULT, val, val2, i;
562 struct ppp_idle idle;
563 struct npioctl npi;
564 int unit, cflags;
565 struct slcompress *vj;
566 void __user *argp = (void __user *)arg;
567 int __user *p = argp;
568
cd228d54 569 if (!pf)
273ec51d
CG		 570 return ppp_unattached_ioctl(current->nsproxy->net_ns,
571 pf, file, cmd, arg);
1da177e4
LT		 572
573 if (cmd == PPPIOCDETACH) {
574 /*
575 * We have to be careful here... if the file descriptor
576 * has been dup'd, we could have another process in the
577 * middle of a poll using the same file *, so we had
578 * better not free the interface data structures -
579 * instead we fail the ioctl. Even in this case, we
580 * shut down the interface if we are the owner of it.
581 * Actually, we should get rid of PPPIOCDETACH, userland
582 * (i.e. pppd) could achieve the same effect by closing
583 * this fd and reopening /dev/ppp.
584 */
585 err = -EINVAL;
f3ff8a4d 586 lock_kernel();
1da177e4
LT		 587 if (pf->kind == INTERFACE) {
588 ppp = PF_TO_PPP(pf);
589 if (file == ppp->owner)
590 ppp_shutdown_interface(ppp);
591 }
516e0cc5 592 if (atomic_long_read(&file->f_count) <= 2) {
f3ff8a4d 593 ppp_release(NULL, file);
1da177e4
LT		 594 err = 0;
595 } else
516e0cc5
AV		 596 printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%ld\n",
597 atomic_long_read(&file->f_count));
f3ff8a4d 598 unlock_kernel();
1da177e4
LT		 599 return err;
600 }
601
602 if (pf->kind == CHANNEL) {
f3ff8a4d 603 struct channel *pch;
1da177e4
LT		 604 struct ppp_channel *chan;
605
f3ff8a4d
AC		 606 lock_kernel();
607 pch = PF_TO_CHANNEL(pf);
608
1da177e4
LT		 609 switch (cmd) {
610 case PPPIOCCONNECT:
611 if (get_user(unit, p))
612 break;
613 err = ppp_connect_channel(pch, unit);
614 break;
615
616 case PPPIOCDISCONN:
617 err = ppp_disconnect_channel(pch);
618 break;
619
620 default:
621 down_read(&pch->chan_sem);
622 chan = pch->chan;
623 err = -ENOTTY;
624 if (chan && chan->ops->ioctl)
625 err = chan->ops->ioctl(chan, cmd, arg);
626 up_read(&pch->chan_sem);
627 }
f3ff8a4d 628 unlock_kernel();
1da177e4
LT		 629 return err;
630 }
631
632 if (pf->kind != INTERFACE) {
633 /* can't happen */
634 printk(KERN_ERR "PPP: not interface or channel??\n");
635 return -EINVAL;
636 }
637
f3ff8a4d 638 lock_kernel();
1da177e4
LT		 639 ppp = PF_TO_PPP(pf);
640 switch (cmd) {
641 case PPPIOCSMRU:
642 if (get_user(val, p))
643 break;
644 ppp->mru = val;
645 err = 0;
646 break;
647
648 case PPPIOCSFLAGS:
649 if (get_user(val, p))
650 break;
651 ppp_lock(ppp);
652 cflags = ppp->flags & ~val;
653 ppp->flags = val & SC_FLAG_BITS;
654 ppp_unlock(ppp);
655 if (cflags & SC_CCP_OPEN)
656 ppp_ccp_closed(ppp);
657 err = 0;
658 break;
659
660 case PPPIOCGFLAGS:
661 val = ppp->flags | ppp->xstate | ppp->rstate;
662 if (put_user(val, p))
663 break;
664 err = 0;
665 break;
666
667 case PPPIOCSCOMPRESS:
668 err = ppp_set_compress(ppp, arg);
669 break;
670
671 case PPPIOCGUNIT:
672 if (put_user(ppp->file.index, p))
673 break;
674 err = 0;
675 break;
676
677 case PPPIOCSDEBUG:
678 if (get_user(val, p))
679 break;
680 ppp->debug = val;
681 err = 0;
682 break;
683
684 case PPPIOCGDEBUG:
685 if (put_user(ppp->debug, p))
686 break;
687 err = 0;
688 break;
689
690 case PPPIOCGIDLE:
691 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
692 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
693 if (copy_to_user(argp, &idle, sizeof(idle)))
694 break;
695 err = 0;
696 break;
697
698 case PPPIOCSMAXCID:
699 if (get_user(val, p))
700 break;
701 val2 = 15;
702 if ((val >> 16) != 0) {
703 val2 = val >> 16;
704 val &= 0xffff;
705 }
706 vj = slhc_init(val2+1, val+1);
cd228d54 707 if (!vj) {
1da177e4
LT		 708 printk(KERN_ERR "PPP: no memory (VJ compressor)\n");
709 err = -ENOMEM;
710 break;
711 }
712 ppp_lock(ppp);
cd228d54 713 if (ppp->vj)
1da177e4
LT		 714 slhc_free(ppp->vj);
715 ppp->vj = vj;
716 ppp_unlock(ppp);
717 err = 0;
718 break;
719
720 case PPPIOCGNPMODE:
721 case PPPIOCSNPMODE:
722 if (copy_from_user(&npi, argp, sizeof(npi)))
723 break;
724 err = proto_to_npindex(npi.protocol);
725 if (err < 0)
726 break;
727 i = err;
728 if (cmd == PPPIOCGNPMODE) {
729 err = -EFAULT;
730 npi.mode = ppp->npmode[i];
731 if (copy_to_user(argp, &npi, sizeof(npi)))
732 break;
733 } else {
734 ppp->npmode[i] = npi.mode;
735 /* we may be able to transmit more packets now (??) */
736 netif_wake_queue(ppp->dev);
737 }
738 err = 0;
739 break;
740
741#ifdef CONFIG_PPP_FILTER
742 case PPPIOCSPASS:
743 {
744 struct sock_filter *code;
745 err = get_filter(argp, &code);
746 if (err >= 0) {
747 ppp_lock(ppp);
748 kfree(ppp->pass_filter);
749 ppp->pass_filter = code;
750 ppp->pass_len = err;
751 ppp_unlock(ppp);
752 err = 0;
753 }
754 break;
755 }
756 case PPPIOCSACTIVE:
757 {
758 struct sock_filter *code;
759 err = get_filter(argp, &code);
760 if (err >= 0) {
761 ppp_lock(ppp);
762 kfree(ppp->active_filter);
763 ppp->active_filter = code;
764 ppp->active_len = err;
765 ppp_unlock(ppp);
766 err = 0;
767 }
768 break;
769 }
770#endif /* CONFIG_PPP_FILTER */
771
772#ifdef CONFIG_PPP_MULTILINK
773 case PPPIOCSMRRU:
774 if (get_user(val, p))
775 break;
776 ppp_recv_lock(ppp);
777 ppp->mrru = val;
778 ppp_recv_unlock(ppp);
779 err = 0;
780 break;
781#endif /* CONFIG_PPP_MULTILINK */
782
783 default:
784 err = -ENOTTY;
785 }
f3ff8a4d 786 unlock_kernel();
1da177e4
LT		 787 return err;
788}
789
273ec51d
CG		 790static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
791 struct file *file, unsigned int cmd, unsigned long arg)
1da177e4
LT		 792{
793 int unit, err = -EFAULT;
794 struct ppp *ppp;
795 struct channel *chan;
273ec51d 796 struct ppp_net *pn;
1da177e4
LT		 797 int __user *p = (int __user *)arg;
798
f3ff8a4d 799 lock_kernel();
1da177e4
LT		 800 switch (cmd) {
801 case PPPIOCNEWUNIT:
802 /* Create a new ppp unit */
803 if (get_user(unit, p))
804 break;
273ec51d 805 ppp = ppp_create_interface(net, unit, &err);
cd228d54 806 if (!ppp)
1da177e4
LT		 807 break;
808 file->private_data = &ppp->file;
809 ppp->owner = file;
810 err = -EFAULT;
811 if (put_user(ppp->file.index, p))
812 break;
813 err = 0;
814 break;
815
816 case PPPIOCATTACH:
817 /* Attach to an existing ppp unit */
818 if (get_user(unit, p))
819 break;
1da177e4 820 err = -ENXIO;
273ec51d
CG		 821 pn = ppp_pernet(net);
822 mutex_lock(&pn->all_ppp_mutex);
823 ppp = ppp_find_unit(pn, unit);
cd228d54 824 if (ppp) {
1da177e4
LT		 825 atomic_inc(&ppp->file.refcnt);
826 file->private_data = &ppp->file;
827 err = 0;
828 }
273ec51d 829 mutex_unlock(&pn->all_ppp_mutex);
1da177e4
LT		 830 break;
831
832 case PPPIOCATTCHAN:
833 if (get_user(unit, p))
834 break;
1da177e4 835 err = -ENXIO;
273ec51d
CG		 836 pn = ppp_pernet(net);
837 spin_lock_bh(&pn->all_channels_lock);
838 chan = ppp_find_channel(pn, unit);
cd228d54 839 if (chan) {
1da177e4
LT		 840 atomic_inc(&chan->file.refcnt);
841 file->private_data = &chan->file;
842 err = 0;
843 }
273ec51d 844 spin_unlock_bh(&pn->all_channels_lock);
1da177e4
LT		 845 break;
846
847 default:
848 err = -ENOTTY;
849 }
f3ff8a4d 850 unlock_kernel();
1da177e4
LT		 851 return err;
852}
853
d54b1fdb 854static const struct file_operations ppp_device_fops = {
1da177e4
LT		 855 .owner = THIS_MODULE,
856 .read = ppp_read,
857 .write = ppp_write,
858 .poll = ppp_poll,
f3ff8a4d 859 .unlocked_ioctl = ppp_ioctl,
1da177e4
LT		 860 .open = ppp_open,
861 .release = ppp_release
862};
863
273ec51d
CG		 864static __net_init int ppp_init_net(struct net *net)
865{
866 struct ppp_net *pn;
867 int err;
868
869 pn = kzalloc(sizeof(*pn), GFP_KERNEL);
870 if (!pn)
871 return -ENOMEM;
872
873 idr_init(&pn->units_idr);
874 mutex_init(&pn->all_ppp_mutex);
875
876 INIT_LIST_HEAD(&pn->all_channels);
877 INIT_LIST_HEAD(&pn->new_channels);
878
879 spin_lock_init(&pn->all_channels_lock);
880
881 err = net_assign_generic(net, ppp_net_id, pn);
882 if (err) {
883 kfree(pn);
884 return err;
885 }
886
887 return 0;
888}
889
890static __net_exit void ppp_exit_net(struct net *net)
891{
892 struct ppp_net *pn;
893
894 pn = net_generic(net, ppp_net_id);
895 idr_destroy(&pn->units_idr);
896 /*
897 * if someone has cached our net then
898 * further net_generic call will return NULL
899 */
900 net_assign_generic(net, ppp_net_id, NULL);
901 kfree(pn);
902}
903
0012985d 904static struct pernet_operations ppp_net_ops = {
273ec51d
CG		 905 .init = ppp_init_net,
906 .exit = ppp_exit_net,
907};
908
1da177e4
LT		 909#define PPP_MAJOR 108
910
911/* Called at boot time if ppp is compiled into the kernel,
912 or at module load time (from init_module) if compiled as a module. */
913static int __init ppp_init(void)
914{
915 int err;
916
917 printk(KERN_INFO "PPP generic driver version " PPP_VERSION "\n");
273ec51d
CG		 918
919 err = register_pernet_gen_device(&ppp_net_id, &ppp_net_ops);
920 if (err) {
921 printk(KERN_ERR "failed to register PPP pernet device (%d)\n", err);
922 goto out;
1da177e4
LT		 923 }
924
273ec51d
CG		 925 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
926 if (err) {
1da177e4 927 printk(KERN_ERR "failed to register PPP device (%d)\n", err);
273ec51d
CG		 928 goto out_net;
929 }
930
931 ppp_class = class_create(THIS_MODULE, "ppp");
932 if (IS_ERR(ppp_class)) {
933 err = PTR_ERR(ppp_class);
934 goto out_chrdev;
935 }
936
937 /* not a big deal if we fail here :-) */
938 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
939
940 return 0;
1da177e4 941
1da177e4
LT		 942out_chrdev:
943 unregister_chrdev(PPP_MAJOR, "ppp");
273ec51d
CG		 944out_net:
945 unregister_pernet_gen_device(ppp_net_id, &ppp_net_ops);
946out:
947 return err;
1da177e4
LT		 948}
949
950/*
951 * Network interface unit routines.
952 */
953static int
954ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
955{
c8019bf3 956 struct ppp *ppp = netdev_priv(dev);
1da177e4
LT		 957 int npi, proto;
958 unsigned char *pp;
959
960 npi = ethertype_to_npindex(ntohs(skb->protocol));
961 if (npi < 0)
962 goto outf;
963
964 /* Drop, accept or reject the packet */
965 switch (ppp->npmode[npi]) {
966 case NPMODE_PASS:
967 break;
968 case NPMODE_QUEUE:
969 /* it would be nice to have a way to tell the network
970 system to queue this one up for later. */
971 goto outf;
972 case NPMODE_DROP:
973 case NPMODE_ERROR:
974 goto outf;
975 }
976
977 /* Put the 2-byte PPP protocol number on the front,
978 making sure there is room for the address and control fields. */
7b797d5b
HX		 979 if (skb_cow_head(skb, PPP_HDRLEN))
980 goto outf;
981
1da177e4
LT		 982 pp = skb_push(skb, 2);
983 proto = npindex_to_proto[npi];
984 pp[0] = proto >> 8;
985 pp[1] = proto;
986
987 netif_stop_queue(dev);
988 skb_queue_tail(&ppp->file.xq, skb);
989 ppp_xmit_process(ppp);
990 return 0;
991
992 outf:
993 kfree_skb(skb);
6ceffd47 994 ++dev->stats.tx_dropped;
1da177e4
LT		 995 return 0;
996}
997
1da177e4
LT		 998static int
999ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1000{
c8019bf3 1001 struct ppp *ppp = netdev_priv(dev);
1da177e4
LT		 1002 int err = -EFAULT;
1003 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
1004 struct ppp_stats stats;
1005 struct ppp_comp_stats cstats;
1006 char *vers;
1007
1008 switch (cmd) {
1009 case SIOCGPPPSTATS:
1010 ppp_get_stats(ppp, &stats);
1011 if (copy_to_user(addr, &stats, sizeof(stats)))
1012 break;
1013 err = 0;
1014 break;
1015
1016 case SIOCGPPPCSTATS:
1017 memset(&cstats, 0, sizeof(cstats));
cd228d54 1018 if (ppp->xc_state)
1da177e4 1019 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
cd228d54 1020 if (ppp->rc_state)
1da177e4
LT		 1021 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
1022 if (copy_to_user(addr, &cstats, sizeof(cstats)))
1023 break;
1024 err = 0;
1025 break;
1026
1027 case SIOCGPPPVER:
1028 vers = PPP_VERSION;
1029 if (copy_to_user(addr, vers, strlen(vers) + 1))
1030 break;
1031 err = 0;
1032 break;
1033
1034 default:
1035 err = -EINVAL;
1036 }
1037
1038 return err;
1039}
1040
52256cfc 1041static const struct net_device_ops ppp_netdev_ops = {
00829823
SH		 1042 .ndo_start_xmit = ppp_start_xmit,
1043 .ndo_do_ioctl = ppp_net_ioctl,
52256cfc
SH		 1044};
1045
1da177e4
LT		 1046static void ppp_setup(struct net_device *dev)
1047{
52256cfc 1048 dev->netdev_ops = &ppp_netdev_ops;
1da177e4
LT		 1049 dev->hard_header_len = PPP_HDRLEN;
1050 dev->mtu = PPP_MTU;
1051 dev->addr_len = 0;
1052 dev->tx_queue_len = 3;
1053 dev->type = ARPHRD_PPP;
1054 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
273ec51d 1055 dev->features |= NETIF_F_NETNS_LOCAL;
1da177e4
LT		 1056}
1057
1058/*
1059 * Transmit-side routines.
1060 */
1061
1062/*
1063 * Called to do any work queued up on the transmit side
1064 * that can now be done.
1065 */
1066static void
1067ppp_xmit_process(struct ppp *ppp)
1068{
1069 struct sk_buff *skb;
1070
1071 ppp_xmit_lock(ppp);
739840d5 1072 if (!ppp->closing) {
1da177e4 1073 ppp_push(ppp);
cd228d54
JP		 1074 while (!ppp->xmit_pending
1075 && (skb = skb_dequeue(&ppp->file.xq)))
1da177e4
LT		 1076 ppp_send_frame(ppp, skb);
1077 /* If there's no work left to do, tell the core net
1078 code that we can accept some more. */
cd228d54 1079 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1da177e4
LT		 1080 netif_wake_queue(ppp->dev);
1081 }
1082 ppp_xmit_unlock(ppp);
1083}
1084
b3f9b92a
MD		 1085static inline struct sk_buff *
1086pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1087{
1088 struct sk_buff *new_skb;
1089 int len;
1090 int new_skb_size = ppp->dev->mtu +
1091 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1092 int compressor_skb_size = ppp->dev->mtu +
1093 ppp->xcomp->comp_extra + PPP_HDRLEN;
1094 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1095 if (!new_skb) {
1096 if (net_ratelimit())
1097 printk(KERN_ERR "PPP: no memory (comp pkt)\n");
1098 return NULL;
1099 }
1100 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1101 skb_reserve(new_skb,
1102 ppp->dev->hard_header_len - PPP_HDRLEN);
1103
1104 /* compressor still expects A/C bytes in hdr */
1105 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1106 new_skb->data, skb->len + 2,
1107 compressor_skb_size);
1108 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1109 kfree_skb(skb);
1110 skb = new_skb;
1111 skb_put(skb, len);
1112 skb_pull(skb, 2); /* pull off A/C bytes */
1113 } else if (len == 0) {
1114 /* didn't compress, or CCP not up yet */
1115 kfree_skb(new_skb);
1116 new_skb = skb;
1117 } else {
1118 /*
1119 * (len < 0)
1120 * MPPE requires that we do not send unencrypted
1121 * frames. The compressor will return -1 if we
1122 * should drop the frame. We cannot simply test
1123 * the compress_proto because MPPE and MPPC share
1124 * the same number.
1125 */
1126 if (net_ratelimit())
1127 printk(KERN_ERR "ppp: compressor dropped pkt\n");
1128 kfree_skb(skb);
1129 kfree_skb(new_skb);
1130 new_skb = NULL;
1131 }
1132 return new_skb;
1133}
1134
1da177e4
LT		 1135/*
1136 * Compress and send a frame.
1137 * The caller should have locked the xmit path,
1138 * and xmit_pending should be 0.
1139 */
1140static void
1141ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1142{
1143 int proto = PPP_PROTO(skb);
1144 struct sk_buff *new_skb;
1145 int len;
1146 unsigned char *cp;
1147
1148 if (proto < 0x8000) {
1149#ifdef CONFIG_PPP_FILTER
1150 /* check if we should pass this packet */
1151 /* the filter instructions are constructed assuming
1152 a four-byte PPP header on each packet */
1153 *skb_push(skb, 2) = 1;
1154 if (ppp->pass_filter
1155 && sk_run_filter(skb, ppp->pass_filter,
1156 ppp->pass_len) == 0) {
1157 if (ppp->debug & 1)
1158 printk(KERN_DEBUG "PPP: outbound frame not passed\n");
1159 kfree_skb(skb);
1160 return;
1161 }
1162 /* if this packet passes the active filter, record the time */
1163 if (!(ppp->active_filter
1164 && sk_run_filter(skb, ppp->active_filter,
1165 ppp->active_len) == 0))
1166 ppp->last_xmit = jiffies;
1167 skb_pull(skb, 2);
1168#else
1169 /* for data packets, record the time */
1170 ppp->last_xmit = jiffies;
1171#endif /* CONFIG_PPP_FILTER */
1172 }
1173
8c0469cd
PZ		 1174 ++ppp->dev->stats.tx_packets;
1175 ppp->dev->stats.tx_bytes += skb->len - 2;
1da177e4
LT		 1176
1177 switch (proto) {
1178 case PPP_IP:
cd228d54 1179 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1da177e4
LT		 1180 break;
1181 /* try to do VJ TCP header compression */
1182 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1183 GFP_ATOMIC);
cd228d54 1184 if (!new_skb) {
1da177e4
LT		 1185 printk(KERN_ERR "PPP: no memory (VJ comp pkt)\n");
1186 goto drop;
1187 }
1188 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1189 cp = skb->data + 2;
1190 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1191 new_skb->data + 2, &cp,
1192 !(ppp->flags & SC_NO_TCP_CCID));
1193 if (cp == skb->data + 2) {
1194 /* didn't compress */
1195 kfree_skb(new_skb);
1196 } else {
1197 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1198 proto = PPP_VJC_COMP;
1199 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1200 } else {
1201 proto = PPP_VJC_UNCOMP;
1202 cp[0] = skb->data[2];
1203 }
1204 kfree_skb(skb);
1205 skb = new_skb;
1206 cp = skb_put(skb, len + 2);
1207 cp[0] = 0;
1208 cp[1] = proto;
1209 }
1210 break;
1211
1212 case PPP_CCP:
1213 /* peek at outbound CCP frames */
1214 ppp_ccp_peek(ppp, skb, 0);
1215 break;
1216 }
1217
1218 /* try to do packet compression */
cd228d54 1219 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state
1da177e4 1220 && proto != PPP_LCP && proto != PPP_CCP) {
b3f9b92a
MD		 1221 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1222 if (net_ratelimit())
1223 printk(KERN_ERR "ppp: compression required but down - pkt dropped.\n");
1da177e4
LT		 1224 goto drop;
1225 }
b3f9b92a
MD		 1226 skb = pad_compress_skb(ppp, skb);
1227 if (!skb)
1228 goto drop;
1da177e4
LT		 1229 }
1230
1231 /*
1232 * If we are waiting for traffic (demand dialling),
1233 * queue it up for pppd to receive.
1234 */
1235 if (ppp->flags & SC_LOOP_TRAFFIC) {
1236 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1237 goto drop;
1238 skb_queue_tail(&ppp->file.rq, skb);
1239 wake_up_interruptible(&ppp->file.rwait);
1240 return;
1241 }
1242
1243 ppp->xmit_pending = skb;
1244 ppp_push(ppp);
1245 return;
1246
1247 drop:
b3f9b92a
MD		 1248 if (skb)
1249 kfree_skb(skb);
8c0469cd 1250 ++ppp->dev->stats.tx_errors;
1da177e4
LT		 1251}
1252
1253/*
1254 * Try to send the frame in xmit_pending.
1255 * The caller should have the xmit path locked.
1256 */
1257static void
1258ppp_push(struct ppp *ppp)
1259{
1260 struct list_head *list;
1261 struct channel *pch;
1262 struct sk_buff *skb = ppp->xmit_pending;
1263
cd228d54 1264 if (!skb)
1da177e4
LT		 1265 return;
1266
1267 list = &ppp->channels;
1268 if (list_empty(list)) {
1269 /* nowhere to send the packet, just drop it */
1270 ppp->xmit_pending = NULL;
1271 kfree_skb(skb);
1272 return;
1273 }
1274
1275 if ((ppp->flags & SC_MULTILINK) == 0) {
1276 /* not doing multilink: send it down the first channel */
1277 list = list->next;
1278 pch = list_entry(list, struct channel, clist);
1279
1280 spin_lock_bh(&pch->downl);
1281 if (pch->chan) {
1282 if (pch->chan->ops->start_xmit(pch->chan, skb))
1283 ppp->xmit_pending = NULL;
1284 } else {
1285 /* channel got unregistered */
1286 kfree_skb(skb);
1287 ppp->xmit_pending = NULL;
1288 }
1289 spin_unlock_bh(&pch->downl);
1290 return;
1291 }
1292
1293#ifdef CONFIG_PPP_MULTILINK
1294 /* Multilink: fragment the packet over as many links
1295 as can take the packet at the moment. */
1296 if (!ppp_mp_explode(ppp, skb))
1297 return;
1298#endif /* CONFIG_PPP_MULTILINK */
1299
1300 ppp->xmit_pending = NULL;
1301 kfree_skb(skb);
1302}
1303
1304#ifdef CONFIG_PPP_MULTILINK
1305/*
1306 * Divide a packet to be transmitted into fragments and
1307 * send them out the individual links.
1308 */
1309static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1310{
516cd15f 1311 int len, fragsize;
1da177e4 1312 int i, bits, hdrlen, mtu;
516cd15f
PM		 1313 int flen;
1314 int navail, nfree;
1315 int nbigger;
1da177e4
LT		 1316 unsigned char *p, *q;
1317 struct list_head *list;
1318 struct channel *pch;
1319 struct sk_buff *frag;
1320 struct ppp_channel *chan;
1321
516cd15f
PM		 1322 nfree = 0; /* # channels which have no packet already queued */
1323 navail = 0; /* total # of usable channels (not deregistered) */
1da177e4 1324 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
516cd15f 1325 i = 0;
81616c5a 1326 list_for_each_entry(pch, &ppp->channels, clist) {
516cd15f
PM		 1327 navail += pch->avail = (pch->chan != NULL);
1328 if (pch->avail) {
b03efcfb
DM		 1329 if (skb_queue_empty(&pch->file.xq) ||
1330 !pch->had_frag) {
516cd15f
PM		 1331 pch->avail = 2;
1332 ++nfree;
1da177e4 1333 }
516cd15f
PM		 1334 if (!pch->had_frag && i < ppp->nxchan)
1335 ppp->nxchan = i;
1da177e4 1336 }
516cd15f 1337 ++i;
1da177e4 1338 }
516cd15f
PM		 1339
1340 /*
1341 * Don't start sending this packet unless at least half of
1342 * the channels are free. This gives much better TCP
1343 * performance if we have a lot of channels.
1344 */
1345 if (nfree == 0 || nfree < navail / 2)
1da177e4
LT		 1346 return 0; /* can't take now, leave it in xmit_pending */
1347
1348 /* Do protocol field compression (XXX this should be optional) */
1349 p = skb->data;
1350 len = skb->len;
1351 if (*p == 0) {
1352 ++p;
1353 --len;
1354 }
1355
516cd15f
PM		 1356 /*
1357 * Decide on fragment size.
1358 * We create a fragment for each free channel regardless of
1359 * how small they are (i.e. even 0 length) in order to minimize
1360 * the time that it will take to detect when a channel drops
1361 * a fragment.
1362 */
1da177e4 1363 fragsize = len;
516cd15f 1364 if (nfree > 1)
57cd5f75 1365 fragsize = DIV_ROUND_UP(fragsize, nfree);
516cd15f
PM		 1366 /* nbigger channels get fragsize bytes, the rest get fragsize-1,
1367 except if nbigger==0, then they all get fragsize. */
1368 nbigger = len % nfree;
1da177e4
LT		 1369
1370 /* skip to the channel after the one we last used
1371 and start at that one */
81616c5a 1372 list = &ppp->channels;
1da177e4
LT		 1373 for (i = 0; i < ppp->nxchan; ++i) {
1374 list = list->next;
1375 if (list == &ppp->channels) {
1376 i = 0;
1377 break;
1378 }
1379 }
1380
1381 /* create a fragment for each channel */
1382 bits = B;
516cd15f 1383 while (nfree > 0 || len > 0) {
1da177e4
LT		 1384 list = list->next;
1385 if (list == &ppp->channels) {
1386 i = 0;
1387 continue;
1388 }
1389 pch = list_entry(list, struct channel, clist);
1390 ++i;
1391 if (!pch->avail)
1392 continue;
1393
516cd15f
PM		 1394 /*
1395 * Skip this channel if it has a fragment pending already and
1396 * we haven't given a fragment to all of the free channels.
1397 */
1398 if (pch->avail == 1) {
1399 if (nfree > 0)
1400 continue;
1401 } else {
1402 --nfree;
1403 pch->avail = 1;
1404 }
1405
1da177e4
LT		 1406 /* check the channel's mtu and whether it is still attached. */
1407 spin_lock_bh(&pch->downl);
516cd15f
PM		 1408 if (pch->chan == NULL) {
1409 /* can't use this channel, it's being deregistered */
1da177e4
LT		 1410 spin_unlock_bh(&pch->downl);
1411 pch->avail = 0;
516cd15f 1412 if (--navail == 0)
1da177e4
LT		 1413 break;
1414 continue;
1415 }
1416
1417 /*
516cd15f
PM		 1418 * Create a fragment for this channel of
1419 * min(max(mtu+2-hdrlen, 4), fragsize, len) bytes.
1420 * If mtu+2-hdrlen < 4, that is a ridiculously small
1421 * MTU, so we use mtu = 2 + hdrlen.
1da177e4
LT		 1422 */
1423 if (fragsize > len)
1424 fragsize = len;
516cd15f
PM		 1425 flen = fragsize;
1426 mtu = pch->chan->mtu + 2 - hdrlen;
1427 if (mtu < 4)
1428 mtu = 4;
1429 if (flen > mtu)
1430 flen = mtu;
1431 if (flen == len && nfree == 0)
1432 bits |= E;
1433 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
cd228d54 1434 if (!frag)
516cd15f
PM		 1435 goto noskb;
1436 q = skb_put(frag, flen + hdrlen);
1437
1438 /* make the MP header */
1439 q[0] = PPP_MP >> 8;
1440 q[1] = PPP_MP;
1441 if (ppp->flags & SC_MP_XSHORTSEQ) {
1442 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1443 q[3] = ppp->nxseq;
1444 } else {
1445 q[2] = bits;
1446 q[3] = ppp->nxseq >> 16;
1447 q[4] = ppp->nxseq >> 8;
1448 q[5] = ppp->nxseq;
1da177e4 1449 }
516cd15f
PM		 1450
1451 /*
1452 * Copy the data in.
1453 * Unfortunately there is a bug in older versions of
1454 * the Linux PPP multilink reconstruction code where it
1455 * drops 0-length fragments. Therefore we make sure the
1456 * fragment has at least one byte of data. Any bytes
1457 * we add in this situation will end up as padding on the
1458 * end of the reconstructed packet.
1459 */
1460 if (flen == 0)
1461 *skb_put(frag, 1) = 0;
1462 else
1463 memcpy(q + hdrlen, p, flen);
1464
1465 /* try to send it down the channel */
1466 chan = pch->chan;
b03efcfb
DM		 1467 if (!skb_queue_empty(&pch->file.xq) ||
1468 !chan->ops->start_xmit(chan, frag))
516cd15f
PM		 1469 skb_queue_tail(&pch->file.xq, frag);
1470 pch->had_frag = 1;
1471 p += flen;
1472 len -= flen;
1473 ++ppp->nxseq;
1474 bits = 0;
1da177e4 1475 spin_unlock_bh(&pch->downl);
516cd15f
PM		 1476
1477 if (--nbigger == 0 && fragsize > 0)
1478 --fragsize;
1479 }
1da177e4
LT		 1480 ppp->nxchan = i;
1481
1482 return 1;
1483
1484 noskb:
1485 spin_unlock_bh(&pch->downl);
1486 if (ppp->debug & 1)
1487 printk(KERN_ERR "PPP: no memory (fragment)\n");
8c0469cd 1488 ++ppp->dev->stats.tx_errors;
1da177e4
LT		 1489 ++ppp->nxseq;
1490 return 1; /* abandon the frame */
1491}
1492#endif /* CONFIG_PPP_MULTILINK */
1493
1494/*
1495 * Try to send data out on a channel.
1496 */
1497static void
1498ppp_channel_push(struct channel *pch)
1499{
1500 struct sk_buff *skb;
1501 struct ppp *ppp;
1502
1503 spin_lock_bh(&pch->downl);
cd228d54 1504 if (pch->chan) {
b03efcfb 1505 while (!skb_queue_empty(&pch->file.xq)) {
1da177e4
LT		 1506 skb = skb_dequeue(&pch->file.xq);
1507 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1508 /* put the packet back and try again later */
1509 skb_queue_head(&pch->file.xq, skb);
1510 break;
1511 }
1512 }
1513 } else {
1514 /* channel got deregistered */
1515 skb_queue_purge(&pch->file.xq);
1516 }
1517 spin_unlock_bh(&pch->downl);
1518 /* see if there is anything from the attached unit to be sent */
b03efcfb 1519 if (skb_queue_empty(&pch->file.xq)) {
1da177e4
LT		 1520 read_lock_bh(&pch->upl);
1521 ppp = pch->ppp;
cd228d54 1522 if (ppp)
1da177e4
LT		 1523 ppp_xmit_process(ppp);
1524 read_unlock_bh(&pch->upl);
1525 }
1526}
1527
1528/*
1529 * Receive-side routines.
1530 */
1531
1532/* misuse a few fields of the skb for MP reconstruction */
1533#define sequence priority
1534#define BEbits cb[0]
1535
1536static inline void
1537ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1538{
1539 ppp_recv_lock(ppp);
739840d5 1540 if (!ppp->closing)
1da177e4
LT		 1541 ppp_receive_frame(ppp, skb, pch);
1542 else
1543 kfree_skb(skb);
1544 ppp_recv_unlock(ppp);
1545}
1546
1547void
1548ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1549{
1550 struct channel *pch = chan->ppp;
1551 int proto;
1552
cd228d54 1553 if (!pch || skb->len == 0) {
1da177e4
LT		 1554 kfree_skb(skb);
1555 return;
1556 }
516cd15f 1557
1da177e4
LT		 1558 proto = PPP_PROTO(skb);
1559 read_lock_bh(&pch->upl);
cd228d54 1560 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1da177e4
LT		 1561 /* put it on the channel queue */
1562 skb_queue_tail(&pch->file.rq, skb);
1563 /* drop old frames if queue too long */
1564 while (pch->file.rq.qlen > PPP_MAX_RQLEN
cd228d54 1565 && (skb = skb_dequeue(&pch->file.rq)))
1da177e4
LT		 1566 kfree_skb(skb);
1567 wake_up_interruptible(&pch->file.rwait);
1568 } else {
1569 ppp_do_recv(pch->ppp, skb, pch);
1570 }
1571 read_unlock_bh(&pch->upl);
1572}
1573
1574/* Put a 0-length skb in the receive queue as an error indication */
1575void
1576ppp_input_error(struct ppp_channel *chan, int code)
1577{
1578 struct channel *pch = chan->ppp;
1579 struct sk_buff *skb;
1580
cd228d54 1581 if (!pch)
1da177e4
LT		 1582 return;
1583
1584 read_lock_bh(&pch->upl);
cd228d54 1585 if (pch->ppp) {
1da177e4 1586 skb = alloc_skb(0, GFP_ATOMIC);
cd228d54 1587 if (skb) {
1da177e4
LT		 1588 skb->len = 0; /* probably unnecessary */
1589 skb->cb[0] = code;
1590 ppp_do_recv(pch->ppp, skb, pch);
1591 }
1592 }
1593 read_unlock_bh(&pch->upl);
1594}
1595
1596/*
1597 * We come in here to process a received frame.
1598 * The receive side of the ppp unit is locked.
1599 */
1600static void
1601ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1602{
2a38b775 1603 if (pskb_may_pull(skb, 2)) {
1da177e4
LT		 1604#ifdef CONFIG_PPP_MULTILINK
1605 /* XXX do channel-level decompression here */
1606 if (PPP_PROTO(skb) == PPP_MP)
1607 ppp_receive_mp_frame(ppp, skb, pch);
1608 else
1609#endif /* CONFIG_PPP_MULTILINK */
1610 ppp_receive_nonmp_frame(ppp, skb);
1611 return;
1612 }
1613
1614 if (skb->len > 0)
1615 /* note: a 0-length skb is used as an error indication */
8c0469cd 1616 ++ppp->dev->stats.rx_length_errors;
1da177e4
LT		 1617
1618 kfree_skb(skb);
1619 ppp_receive_error(ppp);
1620}
1621
1622static void
1623ppp_receive_error(struct ppp *ppp)
1624{
8c0469cd 1625 ++ppp->dev->stats.rx_errors;
cd228d54 1626 if (ppp->vj)
1da177e4
LT		 1627 slhc_toss(ppp->vj);
1628}
1629
1630static void
1631ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1632{
1633 struct sk_buff *ns;
1634 int proto, len, npi;
1635
1636 /*
1637 * Decompress the frame, if compressed.
1638 * Note that some decompressors need to see uncompressed frames
1639 * that come in as well as compressed frames.
1640 */
cd228d54 1641 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)
1da177e4
LT		 1642 && (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1643 skb = ppp_decompress_frame(ppp, skb);
1644
b3f9b92a
MD		 1645 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1646 goto err;
1647
1da177e4
LT		 1648 proto = PPP_PROTO(skb);
1649 switch (proto) {
1650 case PPP_VJC_COMP:
1651 /* decompress VJ compressed packets */
cd228d54 1652 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1da177e4
LT		 1653 goto err;
1654
2a38b775 1655 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1da177e4
LT		 1656 /* copy to a new sk_buff with more tailroom */
1657 ns = dev_alloc_skb(skb->len + 128);
cd228d54 1658 if (!ns) {
1da177e4
LT		 1659 printk(KERN_ERR"PPP: no memory (VJ decomp)\n");
1660 goto err;
1661 }
1662 skb_reserve(ns, 2);
1663 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1664 kfree_skb(skb);
1665 skb = ns;
1666 }
e3f749c4
HX		 1667 else
1668 skb->ip_summed = CHECKSUM_NONE;
1da177e4
LT		 1669
1670 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1671 if (len <= 0) {
1672 printk(KERN_DEBUG "PPP: VJ decompression error\n");
1673 goto err;
1674 }
1675 len += 2;
1676 if (len > skb->len)
1677 skb_put(skb, len - skb->len);
1678 else if (len < skb->len)
1679 skb_trim(skb, len);
1680 proto = PPP_IP;
1681 break;
1682
1683 case PPP_VJC_UNCOMP:
cd228d54 1684 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1da177e4 1685 goto err;
6aa20a22 1686
1da177e4
LT		 1687 /* Until we fix the decompressor need to make sure
1688 * data portion is linear.
1689 */
6aa20a22 1690 if (!pskb_may_pull(skb, skb->len))
1da177e4
LT		 1691 goto err;
1692
1693 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1694 printk(KERN_ERR "PPP: VJ uncompressed error\n");
1695 goto err;
1696 }
1697 proto = PPP_IP;
1698 break;
1699
1700 case PPP_CCP:
1701 ppp_ccp_peek(ppp, skb, 1);
1702 break;
1703 }
1704
8c0469cd
PZ		 1705 ++ppp->dev->stats.rx_packets;
1706 ppp->dev->stats.rx_bytes += skb->len - 2;
1da177e4
LT		 1707
1708 npi = proto_to_npindex(proto);
1709 if (npi < 0) {
1710 /* control or unknown frame - pass it to pppd */
1711 skb_queue_tail(&ppp->file.rq, skb);
1712 /* limit queue length by dropping old frames */
1713 while (ppp->file.rq.qlen > PPP_MAX_RQLEN
cd228d54 1714 && (skb = skb_dequeue(&ppp->file.rq)))
1da177e4
LT		 1715 kfree_skb(skb);
1716 /* wake up any process polling or blocking on read */
1717 wake_up_interruptible(&ppp->file.rwait);
1718
1719 } else {
1720 /* network protocol frame - give it to the kernel */
1721
1722#ifdef CONFIG_PPP_FILTER
1723 /* check if the packet passes the pass and active filters */
1724 /* the filter instructions are constructed assuming
1725 a four-byte PPP header on each packet */
2a38b775
HX		 1726 if (ppp->pass_filter || ppp->active_filter) {
1727 if (skb_cloned(skb) &&
1728 pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
1729 goto err;
1730
1731 *skb_push(skb, 2) = 0;
1732 if (ppp->pass_filter
1733 && sk_run_filter(skb, ppp->pass_filter,
1734 ppp->pass_len) == 0) {
1735 if (ppp->debug & 1)
1736 printk(KERN_DEBUG "PPP: inbound frame "
1737 "not passed\n");
1738 kfree_skb(skb);
1739 return;
1740 }
1741 if (!(ppp->active_filter
1742 && sk_run_filter(skb, ppp->active_filter,
1743 ppp->active_len) == 0))
1744 ppp->last_recv = jiffies;
1745 __skb_pull(skb, 2);
1746 } else
1da177e4 1747#endif /* CONFIG_PPP_FILTER */
2a38b775 1748 ppp->last_recv = jiffies;
1da177e4
LT		 1749
1750 if ((ppp->dev->flags & IFF_UP) == 0
1751 || ppp->npmode[npi] != NPMODE_PASS) {
1752 kfree_skb(skb);
1753 } else {
cbb042f9
HX		 1754 /* chop off protocol */
1755 skb_pull_rcsum(skb, 2);
1da177e4
LT		 1756 skb->dev = ppp->dev;
1757 skb->protocol = htons(npindex_to_ethertype[npi]);
459a98ed 1758 skb_reset_mac_header(skb);
1da177e4 1759 netif_rx(skb);
1da177e4
LT		 1760 }
1761 }
1762 return;
1763
1764 err:
1765 kfree_skb(skb);
1766 ppp_receive_error(ppp);
1767}
1768
1769static struct sk_buff *
1770ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1771{
1772 int proto = PPP_PROTO(skb);
1773 struct sk_buff *ns;
1774 int len;
1775
1776 /* Until we fix all the decompressor's need to make sure
1777 * data portion is linear.
1778 */
1779 if (!pskb_may_pull(skb, skb->len))
1780 goto err;
1781
1782 if (proto == PPP_COMP) {
4b2a8fb3
KS		 1783 int obuff_size;
1784
1785 switch(ppp->rcomp->compress_proto) {
1786 case CI_MPPE:
1787 obuff_size = ppp->mru + PPP_HDRLEN + 1;
1788 break;
1789 default:
1790 obuff_size = ppp->mru + PPP_HDRLEN;
1791 break;
1792 }
1793
1794 ns = dev_alloc_skb(obuff_size);
cd228d54 1795 if (!ns) {
1da177e4
LT		 1796 printk(KERN_ERR "ppp_decompress_frame: no memory\n");
1797 goto err;
1798 }
1799 /* the decompressor still expects the A/C bytes in the hdr */
1800 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
06c7af56 1801 skb->len + 2, ns->data, obuff_size);
1da177e4
LT		 1802 if (len < 0) {
1803 /* Pass the compressed frame to pppd as an
1804 error indication. */
1805 if (len == DECOMP_FATALERROR)
1806 ppp->rstate |= SC_DC_FERROR;
1807 kfree_skb(ns);
1808 goto err;
1809 }
1810
1811 kfree_skb(skb);
1812 skb = ns;
1813 skb_put(skb, len);
1814 skb_pull(skb, 2); /* pull off the A/C bytes */
1815
1816 } else {
1817 /* Uncompressed frame - pass to decompressor so it
1818 can update its dictionary if necessary. */
1819 if (ppp->rcomp->incomp)
1820 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1821 skb->len + 2);
1822 }
1823
1824 return skb;
1825
1826 err:
1827 ppp->rstate |= SC_DC_ERROR;
1828 ppp_receive_error(ppp);
1829 return skb;
1830}
1831
1832#ifdef CONFIG_PPP_MULTILINK
1833/*
1834 * Receive a multilink frame.
1835 * We put it on the reconstruction queue and then pull off
1836 * as many completed frames as we can.
1837 */
1838static void
1839ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1840{
1841 u32 mask, seq;
81616c5a 1842 struct channel *ch;
1da177e4
LT		 1843 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1844
2a38b775 1845 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
1da177e4
LT		 1846 goto err; /* no good, throw it away */
1847
1848 /* Decode sequence number and begin/end bits */
1849 if (ppp->flags & SC_MP_SHORTSEQ) {
1850 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1851 mask = 0xfff;
1852 } else {
1853 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1854 mask = 0xffffff;
1855 }
1856 skb->BEbits = skb->data[2];
1857 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
1858
1859 /*
1860 * Do protocol ID decompression on the first fragment of each packet.
1861 */
1862 if ((skb->BEbits & B) && (skb->data[0] & 1))
1863 *skb_push(skb, 1) = 0;
1864
1865 /*
1866 * Expand sequence number to 32 bits, making it as close
1867 * as possible to ppp->minseq.
1868 */
1869 seq |= ppp->minseq & ~mask;
1870 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
1871 seq += mask + 1;
1872 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
1873 seq -= mask + 1; /* should never happen */
1874 skb->sequence = seq;
1875 pch->lastseq = seq;
1876
1877 /*
1878 * If this packet comes before the next one we were expecting,
1879 * drop it.
1880 */
1881 if (seq_before(seq, ppp->nextseq)) {
1882 kfree_skb(skb);
8c0469cd 1883 ++ppp->dev->stats.rx_dropped;
1da177e4
LT		 1884 ppp_receive_error(ppp);
1885 return;
1886 }
1887
1888 /*
1889 * Reevaluate minseq, the minimum over all channels of the
1890 * last sequence number received on each channel. Because of
1891 * the increasing sequence number rule, we know that any fragment
1892 * before `minseq' which hasn't arrived is never going to arrive.
1893 * The list of channels can't change because we have the receive
1894 * side of the ppp unit locked.
1895 */
81616c5a 1896 list_for_each_entry(ch, &ppp->channels, clist) {
1da177e4
LT		 1897 if (seq_before(ch->lastseq, seq))
1898 seq = ch->lastseq;
1899 }
1900 if (seq_before(ppp->minseq, seq))
1901 ppp->minseq = seq;
1902
1903 /* Put the fragment on the reconstruction queue */
1904 ppp_mp_insert(ppp, skb);
1905
1906 /* If the queue is getting long, don't wait any longer for packets
1907 before the start of the queue. */
38ce7c73
DM		 1908 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
1909 struct sk_buff *skb = skb_peek(&ppp->mrq);
1910 if (seq_before(ppp->minseq, skb->sequence))
1911 ppp->minseq = skb->sequence;
1912 }
1da177e4
LT		 1913
1914 /* Pull completed packets off the queue and receive them. */
cd228d54 1915 while ((skb = ppp_mp_reconstruct(ppp)))
1da177e4
LT		 1916 ppp_receive_nonmp_frame(ppp, skb);
1917
1918 return;
1919
1920 err:
1921 kfree_skb(skb);
1922 ppp_receive_error(ppp);
1923}
1924
1925/*
1926 * Insert a fragment on the MP reconstruction queue.
1927 * The queue is ordered by increasing sequence number.
1928 */
1929static void
1930ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
1931{
1932 struct sk_buff *p;
1933 struct sk_buff_head *list = &ppp->mrq;
1934 u32 seq = skb->sequence;
1935
1936 /* N.B. we don't need to lock the list lock because we have the
1937 ppp unit receive-side lock. */
13c9821e 1938 skb_queue_walk(list, p) {
1da177e4
LT		 1939 if (seq_before(seq, p->sequence))
1940 break;
13c9821e 1941 }
43f59c89 1942 __skb_queue_before(list, p, skb);
1da177e4
LT		 1943}
1944
1945/*
1946 * Reconstruct a packet from the MP fragment queue.
1947 * We go through increasing sequence numbers until we find a
1948 * complete packet, or we get to the sequence number for a fragment
1949 * which hasn't arrived but might still do so.
1950 */
3c582b30 1951static struct sk_buff *
1da177e4
LT		 1952ppp_mp_reconstruct(struct ppp *ppp)
1953{
1954 u32 seq = ppp->nextseq;
1955 u32 minseq = ppp->minseq;
1956 struct sk_buff_head *list = &ppp->mrq;
1957 struct sk_buff *p, *next;
1958 struct sk_buff *head, *tail;
1959 struct sk_buff *skb = NULL;
1960 int lost = 0, len = 0;
1961
1962 if (ppp->mrru == 0) /* do nothing until mrru is set */
1963 return NULL;
1964 head = list->next;
1965 tail = NULL;
1966 for (p = head; p != (struct sk_buff *) list; p = next) {
1967 next = p->next;
1968 if (seq_before(p->sequence, seq)) {
1969 /* this can't happen, anyway ignore the skb */
1970 printk(KERN_ERR "ppp_mp_reconstruct bad seq %u < %u\n",
1971 p->sequence, seq);
1972 head = next;
1973 continue;
1974 }
1975 if (p->sequence != seq) {
1976 /* Fragment `seq' is missing. If it is after
1977 minseq, it might arrive later, so stop here. */
1978 if (seq_after(seq, minseq))
1979 break;
1980 /* Fragment `seq' is lost, keep going. */
1981 lost = 1;
1982 seq = seq_before(minseq, p->sequence)?
1983 minseq + 1: p->sequence;
1984 next = p;
1985 continue;
1986 }
1987
1988 /*
1989 * At this point we know that all the fragments from
1990 * ppp->nextseq to seq are either present or lost.
1991 * Also, there are no complete packets in the queue
1992 * that have no missing fragments and end before this
1993 * fragment.
1994 */
1995
1996 /* B bit set indicates this fragment starts a packet */
1997 if (p->BEbits & B) {
1998 head = p;
1999 lost = 0;
2000 len = 0;
2001 }
2002
2003 len += p->len;
2004
2005 /* Got a complete packet yet? */
2006 if (lost == 0 && (p->BEbits & E) && (head->BEbits & B)) {
2007 if (len > ppp->mrru + 2) {
8c0469cd 2008 ++ppp->dev->stats.rx_length_errors;
1da177e4
LT		 2009 printk(KERN_DEBUG "PPP: reconstructed packet"
2010 " is too long (%d)\n", len);
2011 } else if (p == head) {
2012 /* fragment is complete packet - reuse skb */
2013 tail = p;
2014 skb = skb_get(p);
2015 break;
2016 } else if ((skb = dev_alloc_skb(len)) == NULL) {
8c0469cd 2017 ++ppp->dev->stats.rx_missed_errors;
1da177e4
LT		 2018 printk(KERN_DEBUG "PPP: no memory for "
2019 "reconstructed packet");
2020 } else {
2021 tail = p;
2022 break;
2023 }
2024 ppp->nextseq = seq + 1;
2025 }
2026
2027 /*
2028 * If this is the ending fragment of a packet,
2029 * and we haven't found a complete valid packet yet,
2030 * we can discard up to and including this fragment.
2031 */
2032 if (p->BEbits & E)
2033 head = next;
2034
2035 ++seq;
2036 }
2037
2038 /* If we have a complete packet, copy it all into one skb. */
2039 if (tail != NULL) {
2040 /* If we have discarded any fragments,
2041 signal a receive error. */
2042 if (head->sequence != ppp->nextseq) {
2043 if (ppp->debug & 1)
2044 printk(KERN_DEBUG " missed pkts %u..%u\n",
2045 ppp->nextseq, head->sequence-1);
8c0469cd 2046 ++ppp->dev->stats.rx_dropped;
1da177e4
LT		 2047 ppp_receive_error(ppp);
2048 }
2049
2050 if (head != tail)
2051 /* copy to a single skb */
2052 for (p = head; p != tail->next; p = p->next)
2053 skb_copy_bits(p, 0, skb_put(skb, p->len), p->len);
2054 ppp->nextseq = tail->sequence + 1;
2055 head = tail->next;
2056 }
2057
2058 /* Discard all the skbuffs that we have copied the data out of
2059 or that we can't use. */
2060 while ((p = list->next) != head) {
2061 __skb_unlink(p, list);
2062 kfree_skb(p);
2063 }
2064
2065 return skb;
2066}
2067#endif /* CONFIG_PPP_MULTILINK */
2068
2069/*
2070 * Channel interface.
2071 */
2072
273ec51d
CG		 2073/* Create a new, unattached ppp channel. */
2074int ppp_register_channel(struct ppp_channel *chan)
2075{
2076 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2077}
2078
2079/* Create a new, unattached ppp channel for specified net. */
2080int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
1da177e4
LT		 2081{
2082 struct channel *pch;
273ec51d 2083 struct ppp_net *pn;
1da177e4 2084
d4274b51 2085 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
cd228d54 2086 if (!pch)
1da177e4 2087 return -ENOMEM;
273ec51d
CG		 2088
2089 pn = ppp_pernet(net);
2090
1da177e4
LT		 2091 pch->ppp = NULL;
2092 pch->chan = chan;
273ec51d 2093 pch->chan_net = net;
1da177e4
LT		 2094 chan->ppp = pch;
2095 init_ppp_file(&pch->file, CHANNEL);
2096 pch->file.hdrlen = chan->hdrlen;
2097#ifdef CONFIG_PPP_MULTILINK
2098 pch->lastseq = -1;
2099#endif /* CONFIG_PPP_MULTILINK */
2100 init_rwsem(&pch->chan_sem);
2101 spin_lock_init(&pch->downl);
2102 rwlock_init(&pch->upl);
273ec51d
CG		 2103
2104 spin_lock_bh(&pn->all_channels_lock);
2105 pch->file.index = ++pn->last_channel_index;
2106 list_add(&pch->list, &pn->new_channels);
1da177e4 2107 atomic_inc(&channel_count);
273ec51d
CG		 2108 spin_unlock_bh(&pn->all_channels_lock);
2109
1da177e4
LT		 2110 return 0;
2111}
2112
2113/*
2114 * Return the index of a channel.
2115 */
2116int ppp_channel_index(struct ppp_channel *chan)
2117{
2118 struct channel *pch = chan->ppp;
2119
cd228d54 2120 if (pch)
1da177e4
LT		 2121 return pch->file.index;
2122 return -1;
2123}
2124
2125/*
2126 * Return the PPP unit number to which a channel is connected.
2127 */
2128int ppp_unit_number(struct ppp_channel *chan)
2129{
2130 struct channel *pch = chan->ppp;
2131 int unit = -1;
2132
cd228d54 2133 if (pch) {
1da177e4 2134 read_lock_bh(&pch->upl);
cd228d54 2135 if (pch->ppp)
1da177e4
LT		 2136 unit = pch->ppp->file.index;
2137 read_unlock_bh(&pch->upl);
2138 }
2139 return unit;
2140}
2141
2142/*
2143 * Disconnect a channel from the generic layer.
2144 * This must be called in process context.
2145 */
2146void
2147ppp_unregister_channel(struct ppp_channel *chan)
2148{
2149 struct channel *pch = chan->ppp;
273ec51d 2150 struct ppp_net *pn;
1da177e4 2151
cd228d54 2152 if (!pch)
1da177e4 2153 return; /* should never happen */
273ec51d 2154
1da177e4
LT		 2155 chan->ppp = NULL;
2156
2157 /*
2158 * This ensures that we have returned from any calls into the
2159 * the channel's start_xmit or ioctl routine before we proceed.
2160 */
2161 down_write(&pch->chan_sem);
2162 spin_lock_bh(&pch->downl);
2163 pch->chan = NULL;
2164 spin_unlock_bh(&pch->downl);
2165 up_write(&pch->chan_sem);
2166 ppp_disconnect_channel(pch);
273ec51d
CG		 2167
2168 pn = ppp_pernet(pch->chan_net);
2169 spin_lock_bh(&pn->all_channels_lock);
1da177e4 2170 list_del(&pch->list);
273ec51d
CG		 2171 spin_unlock_bh(&pn->all_channels_lock);
2172
1da177e4
LT		 2173 pch->file.dead = 1;
2174 wake_up_interruptible(&pch->file.rwait);
2175 if (atomic_dec_and_test(&pch->file.refcnt))
2176 ppp_destroy_channel(pch);
2177}
2178
2179/*
2180 * Callback from a channel when it can accept more to transmit.
2181 * This should be called at BH/softirq level, not interrupt level.
2182 */
2183void
2184ppp_output_wakeup(struct ppp_channel *chan)
2185{
2186 struct channel *pch = chan->ppp;
2187
cd228d54 2188 if (!pch)
1da177e4
LT		 2189 return;
2190 ppp_channel_push(pch);
2191}
2192
2193/*
2194 * Compression control.
2195 */
2196
2197/* Process the PPPIOCSCOMPRESS ioctl. */
2198static int
2199ppp_set_compress(struct ppp *ppp, unsigned long arg)
2200{
2201 int err;
2202 struct compressor *cp, *ocomp;
2203 struct ppp_option_data data;
2204 void *state, *ostate;
2205 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2206
2207 err = -EFAULT;
2208 if (copy_from_user(&data, (void __user *) arg, sizeof(data))
2209 || (data.length <= CCP_MAX_OPTION_LENGTH
2210 && copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2211 goto out;
2212 err = -EINVAL;
2213 if (data.length > CCP_MAX_OPTION_LENGTH
2214 || ccp_option[1] < 2 || ccp_option[1] > data.length)
2215 goto out;
2216
a65e5d78
JB		 2217 cp = try_then_request_module(
2218 find_compressor(ccp_option[0]),
2219 "ppp-compress-%d", ccp_option[0]);
cd228d54 2220 if (!cp)
1da177e4
LT		 2221 goto out;
2222
2223 err = -ENOBUFS;
2224 if (data.transmit) {
2225 state = cp->comp_alloc(ccp_option, data.length);
cd228d54 2226 if (state) {
1da177e4
LT		 2227 ppp_xmit_lock(ppp);
2228 ppp->xstate &= ~SC_COMP_RUN;
2229 ocomp = ppp->xcomp;
2230 ostate = ppp->xc_state;
2231 ppp->xcomp = cp;
2232 ppp->xc_state = state;
2233 ppp_xmit_unlock(ppp);
cd228d54 2234 if (ostate) {
1da177e4
LT		 2235 ocomp->comp_free(ostate);
2236 module_put(ocomp->owner);
2237 }
2238 err = 0;
2239 } else
2240 module_put(cp->owner);
2241
2242 } else {
2243 state = cp->decomp_alloc(ccp_option, data.length);
cd228d54 2244 if (state) {
1da177e4
LT		 2245 ppp_recv_lock(ppp);
2246 ppp->rstate &= ~SC_DECOMP_RUN;
2247 ocomp = ppp->rcomp;
2248 ostate = ppp->rc_state;
2249 ppp->rcomp = cp;
2250 ppp->rc_state = state;
2251 ppp_recv_unlock(ppp);
cd228d54 2252 if (ostate) {
1da177e4
LT		 2253 ocomp->decomp_free(ostate);
2254 module_put(ocomp->owner);
2255 }
2256 err = 0;
2257 } else
2258 module_put(cp->owner);
2259 }
2260
2261 out:
2262 return err;
2263}
2264
2265/*
2266 * Look at a CCP packet and update our state accordingly.
2267 * We assume the caller has the xmit or recv path locked.
2268 */
2269static void
2270ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2271{
2272 unsigned char *dp;
2273 int len;
2274
2275 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2276 return; /* no header */
2277 dp = skb->data + 2;
2278
2279 switch (CCP_CODE(dp)) {
2280 case CCP_CONFREQ:
2281
6aa20a22 2282 /* A ConfReq starts negotiation of compression
1da177e4
LT		 2283 * in one direction of transmission,
2284 * and hence brings it down...but which way?
2285 *
2286 * Remember:
2287 * A ConfReq indicates what the sender would like to receive
2288 */
2289 if(inbound)
2290 /* He is proposing what I should send */
2291 ppp->xstate &= ~SC_COMP_RUN;
6aa20a22 2292 else
1da177e4
LT		 2293 /* I am proposing to what he should send */
2294 ppp->rstate &= ~SC_DECOMP_RUN;
6aa20a22 2295
1da177e4 2296 break;
6aa20a22 2297
1da177e4
LT		 2298 case CCP_TERMREQ:
2299 case CCP_TERMACK:
2300 /*
6aa20a22 2301 * CCP is going down, both directions of transmission
1da177e4
LT		 2302 */
2303 ppp->rstate &= ~SC_DECOMP_RUN;
2304 ppp->xstate &= ~SC_COMP_RUN;
2305 break;
2306
2307 case CCP_CONFACK:
2308 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2309 break;
2310 len = CCP_LENGTH(dp);
2311 if (!pskb_may_pull(skb, len + 2))
2312 return; /* too short */
2313 dp += CCP_HDRLEN;
2314 len -= CCP_HDRLEN;
2315 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2316 break;
2317 if (inbound) {
2318 /* we will start receiving compressed packets */
cd228d54 2319 if (!ppp->rc_state)
1da177e4
LT		 2320 break;
2321 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2322 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2323 ppp->rstate |= SC_DECOMP_RUN;
2324 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2325 }
2326 } else {
2327 /* we will soon start sending compressed packets */
cd228d54 2328 if (!ppp->xc_state)
1da177e4
LT		 2329 break;
2330 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2331 ppp->file.index, 0, ppp->debug))
2332 ppp->xstate |= SC_COMP_RUN;
2333 }
2334 break;
2335
2336 case CCP_RESETACK:
2337 /* reset the [de]compressor */
2338 if ((ppp->flags & SC_CCP_UP) == 0)
2339 break;
2340 if (inbound) {
2341 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2342 ppp->rcomp->decomp_reset(ppp->rc_state);
2343 ppp->rstate &= ~SC_DC_ERROR;
2344 }
2345 } else {
2346 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2347 ppp->xcomp->comp_reset(ppp->xc_state);
2348 }
2349 break;
2350 }
2351}
2352
2353/* Free up compression resources. */
2354static void
2355ppp_ccp_closed(struct ppp *ppp)
2356{
2357 void *xstate, *rstate;
2358 struct compressor *xcomp, *rcomp;
2359
2360 ppp_lock(ppp);
2361 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2362 ppp->xstate = 0;
2363 xcomp = ppp->xcomp;
2364 xstate = ppp->xc_state;
2365 ppp->xc_state = NULL;
2366 ppp->rstate = 0;
2367 rcomp = ppp->rcomp;
2368 rstate = ppp->rc_state;
2369 ppp->rc_state = NULL;
2370 ppp_unlock(ppp);
2371
2372 if (xstate) {
2373 xcomp->comp_free(xstate);
2374 module_put(xcomp->owner);
2375 }
2376 if (rstate) {
2377 rcomp->decomp_free(rstate);
2378 module_put(rcomp->owner);
2379 }
2380}
2381
2382/* List of compressors. */
2383static LIST_HEAD(compressor_list);
2384static DEFINE_SPINLOCK(compressor_list_lock);
2385
2386struct compressor_entry {
2387 struct list_head list;
2388 struct compressor *comp;
2389};
2390
2391static struct compressor_entry *
2392find_comp_entry(int proto)
2393{
2394 struct compressor_entry *ce;
1da177e4 2395
81616c5a 2396 list_for_each_entry(ce, &compressor_list, list) {
1da177e4
LT		 2397 if (ce->comp->compress_proto == proto)
2398 return ce;
2399 }
2400 return NULL;
2401}
2402
2403/* Register a compressor */
2404int
2405ppp_register_compressor(struct compressor *cp)
2406{
2407 struct compressor_entry *ce;
2408 int ret;
2409 spin_lock(&compressor_list_lock);
2410 ret = -EEXIST;
cd228d54 2411 if (find_comp_entry(cp->compress_proto))
1da177e4
LT		 2412 goto out;
2413 ret = -ENOMEM;
2414 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
cd228d54 2415 if (!ce)
1da177e4
LT		 2416 goto out;
2417 ret = 0;
2418 ce->comp = cp;
2419 list_add(&ce->list, &compressor_list);
2420 out:
2421 spin_unlock(&compressor_list_lock);
2422 return ret;
2423}
2424
2425/* Unregister a compressor */
2426void
2427ppp_unregister_compressor(struct compressor *cp)
2428{
2429 struct compressor_entry *ce;
2430
2431 spin_lock(&compressor_list_lock);
2432 ce = find_comp_entry(cp->compress_proto);
cd228d54 2433 if (ce && ce->comp == cp) {
1da177e4
LT		 2434 list_del(&ce->list);
2435 kfree(ce);
2436 }
2437 spin_unlock(&compressor_list_lock);
2438}
2439
2440/* Find a compressor. */
2441static struct compressor *
2442find_compressor(int type)
2443{
2444 struct compressor_entry *ce;
2445 struct compressor *cp = NULL;
2446
2447 spin_lock(&compressor_list_lock);
2448 ce = find_comp_entry(type);
cd228d54 2449 if (ce) {
1da177e4
LT		 2450 cp = ce->comp;
2451 if (!try_module_get(cp->owner))
2452 cp = NULL;
2453 }
2454 spin_unlock(&compressor_list_lock);
2455 return cp;
2456}
2457
2458/*
2459 * Miscelleneous stuff.
2460 */
2461
2462static void
2463ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2464{
2465 struct slcompress *vj = ppp->vj;
2466
2467 memset(st, 0, sizeof(*st));
8c0469cd
PZ		 2468 st->p.ppp_ipackets = ppp->dev->stats.rx_packets;
2469 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2470 st->p.ppp_ibytes = ppp->dev->stats.rx_bytes;
2471 st->p.ppp_opackets = ppp->dev->stats.tx_packets;
2472 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2473 st->p.ppp_obytes = ppp->dev->stats.tx_bytes;
cd228d54 2474 if (!vj)
1da177e4
LT		 2475 return;
2476 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2477 st->vj.vjs_compressed = vj->sls_o_compressed;
2478 st->vj.vjs_searches = vj->sls_o_searches;
2479 st->vj.vjs_misses = vj->sls_o_misses;
2480 st->vj.vjs_errorin = vj->sls_i_error;
2481 st->vj.vjs_tossed = vj->sls_i_tossed;
2482 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2483 st->vj.vjs_compressedin = vj->sls_i_compressed;
2484}
2485
2486/*
2487 * Stuff for handling the lists of ppp units and channels
2488 * and for initialization.
2489 */
2490
2491/*
2492 * Create a new ppp interface unit. Fails if it can't allocate memory
2493 * or if there is already a unit with the requested number.
2494 * unit == -1 means allocate a new number.
2495 */
2496static struct ppp *
273ec51d 2497ppp_create_interface(struct net *net, int unit, int *retp)
1da177e4
LT		 2498{
2499 struct ppp *ppp;
273ec51d 2500 struct ppp_net *pn;
1da177e4
LT		 2501 struct net_device *dev = NULL;
2502 int ret = -ENOMEM;
2503 int i;
2504
c8019bf3 2505 dev = alloc_netdev(sizeof(struct ppp), "", ppp_setup);
1da177e4
LT		 2506 if (!dev)
2507 goto out1;
1da177e4 2508
273ec51d
CG		 2509 pn = ppp_pernet(net);
2510
c8019bf3
WC		 2511 ppp = netdev_priv(dev);
2512 ppp->dev = dev;
1da177e4
LT		 2513 ppp->mru = PPP_MRU;
2514 init_ppp_file(&ppp->file, INTERFACE);
2515 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2516 for (i = 0; i < NUM_NP; ++i)
2517 ppp->npmode[i] = NPMODE_PASS;
2518 INIT_LIST_HEAD(&ppp->channels);
2519 spin_lock_init(&ppp->rlock);
2520 spin_lock_init(&ppp->wlock);
2521#ifdef CONFIG_PPP_MULTILINK
2522 ppp->minseq = -1;
2523 skb_queue_head_init(&ppp->mrq);
2524#endif /* CONFIG_PPP_MULTILINK */
1da177e4 2525
273ec51d
CG		 2526 /*
2527 * drum roll: don't forget to set
2528 * the net device is belong to
2529 */
2530 dev_net_set(dev, net);
2531
1da177e4 2532 ret = -EEXIST;
273ec51d 2533 mutex_lock(&pn->all_ppp_mutex);
7a95d267
CG		 2534
2535 if (unit < 0) {
273ec51d 2536 unit = unit_get(&pn->units_idr, ppp);
7a95d267
CG		 2537 if (unit < 0) {
2538 *retp = unit;
2539 goto out2;
2540 }
2541 } else {
273ec51d 2542 if (unit_find(&pn->units_idr, unit))
7a95d267 2543 goto out2; /* unit already exists */
85997576
CG		 2544 /*
2545 * if caller need a specified unit number
2546 * lets try to satisfy him, otherwise --
2547 * he should better ask us for new unit number
2548 *
2549 * NOTE: yes I know that returning EEXIST it's not
2550 * fair but at least pppd will ask us to allocate
2551 * new unit in this case so user is happy :)
2552 */
273ec51d 2553 unit = unit_set(&pn->units_idr, ppp, unit);
85997576 2554 if (unit < 0)
7a95d267 2555 goto out2;
7a95d267 2556 }
1da177e4
LT		 2557
2558 /* Initialize the new ppp unit */
2559 ppp->file.index = unit;
2560 sprintf(dev->name, "ppp%d", unit);
2561
2562 ret = register_netdev(dev);
2563 if (ret != 0) {
273ec51d 2564 unit_put(&pn->units_idr, unit);
1da177e4
LT		 2565 printk(KERN_ERR "PPP: couldn't register device %s (%d)\n",
2566 dev->name, ret);
2567 goto out2;
2568 }
2569
273ec51d
CG		 2570 ppp->ppp_net = net;
2571
1da177e4 2572 atomic_inc(&ppp_unit_count);
273ec51d 2573 mutex_unlock(&pn->all_ppp_mutex);
7a95d267 2574
1da177e4
LT		 2575 *retp = 0;
2576 return ppp;
2577
2578out2:
273ec51d 2579 mutex_unlock(&pn->all_ppp_mutex);
1da177e4
LT		 2580 free_netdev(dev);
2581out1:
1da177e4
LT		 2582 *retp = ret;
2583 return NULL;
2584}
2585
2586/*
2587 * Initialize a ppp_file structure.
2588 */
2589static void
2590init_ppp_file(struct ppp_file *pf, int kind)
2591{
2592 pf->kind = kind;
2593 skb_queue_head_init(&pf->xq);
2594 skb_queue_head_init(&pf->rq);
2595 atomic_set(&pf->refcnt, 1);
2596 init_waitqueue_head(&pf->rwait);
2597}
2598
2599/*
2600 * Take down a ppp interface unit - called when the owning file
2601 * (the one that created the unit) is closed or detached.
2602 */
2603static void ppp_shutdown_interface(struct ppp *ppp)
2604{
273ec51d
CG		 2605 struct ppp_net *pn;
2606
2607 pn = ppp_pernet(ppp->ppp_net);
2608 mutex_lock(&pn->all_ppp_mutex);
2609
1da177e4 2610 /* This will call dev_close() for us. */
739840d5
JC		 2611 ppp_lock(ppp);
2612 if (!ppp->closing) {
2613 ppp->closing = 1;
2614 ppp_unlock(ppp);
2615 unregister_netdev(ppp->dev);
2616 } else
2617 ppp_unlock(ppp);
2618
273ec51d 2619 unit_put(&pn->units_idr, ppp->file.index);
1da177e4
LT		 2620 ppp->file.dead = 1;
2621 ppp->owner = NULL;
2622 wake_up_interruptible(&ppp->file.rwait);
273ec51d
CG		 2623
2624 mutex_unlock(&pn->all_ppp_mutex);
1da177e4
LT		 2625}
2626
2627/*
2628 * Free the memory used by a ppp unit. This is only called once
2629 * there are no channels connected to the unit and no file structs
2630 * that reference the unit.
2631 */
2632static void ppp_destroy_interface(struct ppp *ppp)
2633{
2634 atomic_dec(&ppp_unit_count);
2635
2636 if (!ppp->file.dead || ppp->n_channels) {
2637 /* "can't happen" */
2638 printk(KERN_ERR "ppp: destroying ppp struct %p but dead=%d "
2639 "n_channels=%d !\n", ppp, ppp->file.dead,
2640 ppp->n_channels);
2641 return;
2642 }
2643
2644 ppp_ccp_closed(ppp);
2645 if (ppp->vj) {
2646 slhc_free(ppp->vj);
2647 ppp->vj = NULL;
2648 }
2649 skb_queue_purge(&ppp->file.xq);
2650 skb_queue_purge(&ppp->file.rq);
2651#ifdef CONFIG_PPP_MULTILINK
2652 skb_queue_purge(&ppp->mrq);
2653#endif /* CONFIG_PPP_MULTILINK */
2654#ifdef CONFIG_PPP_FILTER
96edf83c
JJ		 2655 kfree(ppp->pass_filter);
2656 ppp->pass_filter = NULL;
2657 kfree(ppp->active_filter);
2658 ppp->active_filter = NULL;
1da177e4
LT		 2659#endif /* CONFIG_PPP_FILTER */
2660
165de5b7
L		 2661 if (ppp->xmit_pending)
2662 kfree_skb(ppp->xmit_pending);
2663
739840d5 2664 free_netdev(ppp->dev);
1da177e4
LT		 2665}
2666
2667/*
2668 * Locate an existing ppp unit.
8ed965d6 2669 * The caller should have locked the all_ppp_mutex.
1da177e4
LT		 2670 */
2671static struct ppp *
273ec51d 2672ppp_find_unit(struct ppp_net *pn, int unit)
1da177e4 2673{
273ec51d 2674 return unit_find(&pn->units_idr, unit);
1da177e4
LT		 2675}
2676
2677/*
2678 * Locate an existing ppp channel.
2679 * The caller should have locked the all_channels_lock.
2680 * First we look in the new_channels list, then in the
2681 * all_channels list. If found in the new_channels list,
2682 * we move it to the all_channels list. This is for speed
2683 * when we have a lot of channels in use.
2684 */
2685static struct channel *
273ec51d 2686ppp_find_channel(struct ppp_net *pn, int unit)
1da177e4
LT		 2687{
2688 struct channel *pch;
1da177e4 2689
273ec51d 2690 list_for_each_entry(pch, &pn->new_channels, list) {
1da177e4 2691 if (pch->file.index == unit) {
273ec51d 2692 list_move(&pch->list, &pn->all_channels);
1da177e4
LT		 2693 return pch;
2694 }
2695 }
273ec51d
CG		 2696
2697 list_for_each_entry(pch, &pn->all_channels, list) {
1da177e4
LT		 2698 if (pch->file.index == unit)
2699 return pch;
2700 }
273ec51d 2701
1da177e4
LT		 2702 return NULL;
2703}
2704
2705/*
2706 * Connect a PPP channel to a PPP interface unit.
2707 */
2708static int
2709ppp_connect_channel(struct channel *pch, int unit)
2710{
2711 struct ppp *ppp;
273ec51d 2712 struct ppp_net *pn;
1da177e4
LT		 2713 int ret = -ENXIO;
2714 int hdrlen;
2715
273ec51d
CG		 2716 pn = ppp_pernet(pch->chan_net);
2717
2718 mutex_lock(&pn->all_ppp_mutex);
2719 ppp = ppp_find_unit(pn, unit);
cd228d54 2720 if (!ppp)
1da177e4
LT		 2721 goto out;
2722 write_lock_bh(&pch->upl);
2723 ret = -EINVAL;
cd228d54 2724 if (pch->ppp)
1da177e4
LT		 2725 goto outl;
2726
2727 ppp_lock(ppp);
2728 if (pch->file.hdrlen > ppp->file.hdrlen)
2729 ppp->file.hdrlen = pch->file.hdrlen;
2730 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
739840d5 2731 if (hdrlen > ppp->dev->hard_header_len)
1da177e4
LT		 2732 ppp->dev->hard_header_len = hdrlen;
2733 list_add_tail(&pch->clist, &ppp->channels);
2734 ++ppp->n_channels;
2735 pch->ppp = ppp;
2736 atomic_inc(&ppp->file.refcnt);
2737 ppp_unlock(ppp);
2738 ret = 0;
2739
2740 outl:
2741 write_unlock_bh(&pch->upl);
2742 out:
273ec51d 2743 mutex_unlock(&pn->all_ppp_mutex);
1da177e4
LT		 2744 return ret;
2745}
2746
2747/*
2748 * Disconnect a channel from its ppp unit.
2749 */
2750static int
2751ppp_disconnect_channel(struct channel *pch)
2752{
2753 struct ppp *ppp;
2754 int err = -EINVAL;
2755
2756 write_lock_bh(&pch->upl);
2757 ppp = pch->ppp;
2758 pch->ppp = NULL;
2759 write_unlock_bh(&pch->upl);
cd228d54 2760 if (ppp) {
1da177e4
LT		 2761 /* remove it from the ppp unit's list */
2762 ppp_lock(ppp);
2763 list_del(&pch->clist);
2764 if (--ppp->n_channels == 0)
2765 wake_up_interruptible(&ppp->file.rwait);
2766 ppp_unlock(ppp);
2767 if (atomic_dec_and_test(&ppp->file.refcnt))
2768 ppp_destroy_interface(ppp);
2769 err = 0;
2770 }
2771 return err;
2772}
2773
2774/*
2775 * Free up the resources used by a ppp channel.
2776 */
2777static void ppp_destroy_channel(struct channel *pch)
2778{
2779 atomic_dec(&channel_count);
2780
2781 if (!pch->file.dead) {
2782 /* "can't happen" */
2783 printk(KERN_ERR "ppp: destroying undead channel %p !\n",
2784 pch);
2785 return;
2786 }
2787 skb_queue_purge(&pch->file.xq);
2788 skb_queue_purge(&pch->file.rq);
2789 kfree(pch);
2790}
2791
2792static void __exit ppp_cleanup(void)
2793{
2794 /* should never happen */
2795 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2796 printk(KERN_ERR "PPP: removing module but units remain!\n");
68fc4fab 2797 unregister_chrdev(PPP_MAJOR, "ppp");
9a6a2a5e 2798 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
56b22935 2799 class_destroy(ppp_class);
273ec51d 2800 unregister_pernet_gen_device(ppp_net_id, &ppp_net_ops);
1da177e4
LT		 2801}
2802
2803/*
7a95d267
CG		 2804 * Units handling. Caller must protect concurrent access
2805 * by holding all_ppp_mutex
1da177e4 2806 */
7a95d267 2807
85997576
CG		 2808/* associate pointer with specified number */
2809static int unit_set(struct idr *p, void *ptr, int n)
2810{
2811 int unit, err;
2812
2813again:
2814 if (!idr_pre_get(p, GFP_KERNEL)) {
2815 printk(KERN_ERR "PPP: No free memory for idr\n");
2816 return -ENOMEM;
2817 }
2818
2819 err = idr_get_new_above(p, ptr, n, &unit);
2820 if (err == -EAGAIN)
2821 goto again;
2822
2823 if (unit != n) {
2824 idr_remove(p, unit);
2825 return -EINVAL;
2826 }
2827
2828 return unit;
2829}
2830
7a95d267
CG		 2831/* get new free unit number and associate pointer with it */
2832static int unit_get(struct idr *p, void *ptr)
1da177e4 2833{
7a95d267 2834 int unit, err;
1da177e4 2835
7a95d267 2836again:
85997576
CG		 2837 if (!idr_pre_get(p, GFP_KERNEL)) {
2838 printk(KERN_ERR "PPP: No free memory for idr\n");
7a95d267 2839 return -ENOMEM;
1da177e4 2840 }
1da177e4 2841
7a95d267
CG		 2842 err = idr_get_new_above(p, ptr, 0, &unit);
2843 if (err == -EAGAIN)
2844 goto again;
1da177e4 2845
7a95d267 2846 return unit;
1da177e4
LT		 2847}
2848
7a95d267
CG		 2849/* put unit number back to a pool */
2850static void unit_put(struct idr *p, int n)
1da177e4 2851{
7a95d267 2852 idr_remove(p, n);
1da177e4
LT		 2853}
2854
7a95d267
CG		 2855/* get pointer associated with the number */
2856static void *unit_find(struct idr *p, int n)
1da177e4 2857{
7a95d267 2858 return idr_find(p, n);
1da177e4
LT		 2859}
2860
2861/* Module/initialization stuff */
2862
2863module_init(ppp_init);
2864module_exit(ppp_cleanup);
2865
273ec51d 2866EXPORT_SYMBOL(ppp_register_net_channel);
1da177e4
LT		 2867EXPORT_SYMBOL(ppp_register_channel);
2868EXPORT_SYMBOL(ppp_unregister_channel);
2869EXPORT_SYMBOL(ppp_channel_index);
2870EXPORT_SYMBOL(ppp_unit_number);
2871EXPORT_SYMBOL(ppp_input);
2872EXPORT_SYMBOL(ppp_input_error);
2873EXPORT_SYMBOL(ppp_output_wakeup);
2874EXPORT_SYMBOL(ppp_register_compressor);
2875EXPORT_SYMBOL(ppp_unregister_compressor);
2876MODULE_LICENSE("GPL");
2877MODULE_ALIAS_CHARDEV_MAJOR(PPP_MAJOR);
2878MODULE_ALIAS("/dev/ppp");
Clone of davem's net-next-2.6 tree