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