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