2 * Generic PPP layer for Linux.
4 * Copyright 1999-2002 Paul Mackerras.
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.
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
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.
22 * ==FILEVERSION 20041108==
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>
30 #include <linux/netdevice.h>
31 #include <linux/poll.h>
32 #include <linux/ppp_defs.h>
33 #include <linux/filter.h>
34 #include <linux/if_ppp.h>
35 #include <linux/ppp_channel.h>
36 #include <linux/ppp-comp.h>
37 #include <linux/skbuff.h>
38 #include <linux/rtnetlink.h>
39 #include <linux/if_arp.h>
41 #include <linux/tcp.h>
42 #include <linux/smp_lock.h>
43 #include <linux/spinlock.h>
44 #include <linux/rwsem.h>
45 #include <linux/stddef.h>
46 #include <linux/device.h>
47 #include <linux/mutex.h>
48 #include <net/slhc_vj.h>
49 #include <asm/atomic.h>
51 #define PPP_VERSION "2.4.2"
54 * Network protocols we support.
56 #define NP_IP 0 /* Internet Protocol V4 */
57 #define NP_IPV6 1 /* Internet Protocol V6 */
58 #define NP_IPX 2 /* IPX protocol */
59 #define NP_AT 3 /* Appletalk protocol */
60 #define NP_MPLS_UC 4 /* MPLS unicast */
61 #define NP_MPLS_MC 5 /* MPLS multicast */
62 #define NUM_NP 6 /* Number of NPs. */
64 #define MPHDRLEN 6 /* multilink protocol header length */
65 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */
66 #define MIN_FRAG_SIZE 64
69 * An instance of /dev/ppp can be associated with either a ppp
70 * interface unit or a ppp channel. In both cases, file->private_data
71 * points to one of these.
77 struct sk_buff_head xq
; /* pppd transmit queue */
78 struct sk_buff_head rq
; /* receive queue for pppd */
79 wait_queue_head_t rwait
; /* for poll on reading /dev/ppp */
80 atomic_t refcnt
; /* # refs (incl /dev/ppp attached) */
81 int hdrlen
; /* space to leave for headers */
82 int index
; /* interface unit / channel number */
83 int dead
; /* unit/channel has been shut down */
86 #define PF_TO_X(pf, X) container_of(pf, X, file)
88 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
89 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
92 * Data structure describing one ppp unit.
93 * A ppp unit corresponds to a ppp network interface device
94 * and represents a multilink bundle.
95 * It can have 0 or more ppp channels connected to it.
98 struct ppp_file file
; /* stuff for read/write/poll 0 */
99 struct file
*owner
; /* file that owns this unit 48 */
100 struct list_head channels
; /* list of attached channels 4c */
101 int n_channels
; /* how many channels are attached 54 */
102 spinlock_t rlock
; /* lock for receive side 58 */
103 spinlock_t wlock
; /* lock for transmit side 5c */
104 int mru
; /* max receive unit 60 */
105 unsigned int flags
; /* control bits 64 */
106 unsigned int xstate
; /* transmit state bits 68 */
107 unsigned int rstate
; /* receive state bits 6c */
108 int debug
; /* debug flags 70 */
109 struct slcompress
*vj
; /* state for VJ header compression */
110 enum NPmode npmode
[NUM_NP
]; /* what to do with each net proto 78 */
111 struct sk_buff
*xmit_pending
; /* a packet ready to go out 88 */
112 struct compressor
*xcomp
; /* transmit packet compressor 8c */
113 void *xc_state
; /* its internal state 90 */
114 struct compressor
*rcomp
; /* receive decompressor 94 */
115 void *rc_state
; /* its internal state 98 */
116 unsigned long last_xmit
; /* jiffies when last pkt sent 9c */
117 unsigned long last_recv
; /* jiffies when last pkt rcvd a0 */
118 struct net_device
*dev
; /* network interface device a4 */
119 #ifdef CONFIG_PPP_MULTILINK
120 int nxchan
; /* next channel to send something on */
121 u32 nxseq
; /* next sequence number to send */
122 int mrru
; /* MP: max reconst. receive unit */
123 u32 nextseq
; /* MP: seq no of next packet */
124 u32 minseq
; /* MP: min of most recent seqnos */
125 struct sk_buff_head mrq
; /* MP: receive reconstruction queue */
126 #endif /* CONFIG_PPP_MULTILINK */
127 #ifdef CONFIG_PPP_FILTER
128 struct sock_filter
*pass_filter
; /* filter for packets to pass */
129 struct sock_filter
*active_filter
;/* filter for pkts to reset idle */
130 unsigned pass_len
, active_len
;
131 #endif /* CONFIG_PPP_FILTER */
135 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
136 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
138 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
139 * Bits in xstate: SC_COMP_RUN
141 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
142 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
143 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
146 * Private data structure for each channel.
147 * This includes the data structure used for multilink.
150 struct ppp_file file
; /* stuff for read/write/poll */
151 struct list_head list
; /* link in all/new_channels list */
152 struct ppp_channel
*chan
; /* public channel data structure */
153 struct rw_semaphore chan_sem
; /* protects `chan' during chan ioctl */
154 spinlock_t downl
; /* protects `chan', file.xq dequeue */
155 struct ppp
*ppp
; /* ppp unit we're connected to */
156 struct list_head clist
; /* link in list of channels per unit */
157 rwlock_t upl
; /* protects `ppp' */
158 #ifdef CONFIG_PPP_MULTILINK
159 u8 avail
; /* flag used in multilink stuff */
160 u8 had_frag
; /* >= 1 fragments have been sent */
161 u32 lastseq
; /* MP: last sequence # received */
162 #endif /* CONFIG_PPP_MULTILINK */
166 * SMP locking issues:
167 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
168 * list and the ppp.n_channels field, you need to take both locks
169 * before you modify them.
170 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
175 * A cardmap represents a mapping from unsigned integers to pointers,
176 * and provides a fast "find lowest unused number" operation.
177 * It uses a broad (32-way) tree with a bitmap at each level.
178 * It is designed to be space-efficient for small numbers of entries
179 * and time-efficient for large numbers of entries.
181 #define CARDMAP_ORDER 5
182 #define CARDMAP_WIDTH (1U << CARDMAP_ORDER)
183 #define CARDMAP_MASK (CARDMAP_WIDTH - 1)
188 struct cardmap
*parent
;
189 void *ptr
[CARDMAP_WIDTH
];
191 static void *cardmap_get(struct cardmap
*map
, unsigned int nr
);
192 static int cardmap_set(struct cardmap
**map
, unsigned int nr
, void *ptr
);
193 static unsigned int cardmap_find_first_free(struct cardmap
*map
);
194 static void cardmap_destroy(struct cardmap
**map
);
197 * all_ppp_mutex protects the all_ppp_units mapping.
198 * It also ensures that finding a ppp unit in the all_ppp_units map
199 * and updating its file.refcnt field is atomic.
201 static DEFINE_MUTEX(all_ppp_mutex
);
202 static struct cardmap
*all_ppp_units
;
203 static atomic_t ppp_unit_count
= ATOMIC_INIT(0);
206 * all_channels_lock protects all_channels and last_channel_index,
207 * and the atomicity of find a channel and updating its file.refcnt
210 static DEFINE_SPINLOCK(all_channels_lock
);
211 static LIST_HEAD(all_channels
);
212 static LIST_HEAD(new_channels
);
213 static int last_channel_index
;
214 static atomic_t channel_count
= ATOMIC_INIT(0);
216 /* Get the PPP protocol number from a skb */
217 #define PPP_PROTO(skb) (((skb)->data[0] << 8) + (skb)->data[1])
219 /* We limit the length of ppp->file.rq to this (arbitrary) value */
220 #define PPP_MAX_RQLEN 32
223 * Maximum number of multilink fragments queued up.
224 * This has to be large enough to cope with the maximum latency of
225 * the slowest channel relative to the others. Strictly it should
226 * depend on the number of channels and their characteristics.
228 #define PPP_MP_MAX_QLEN 128
230 /* Multilink header bits. */
231 #define B 0x80 /* this fragment begins a packet */
232 #define E 0x40 /* this fragment ends a packet */
234 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */
235 #define seq_before(a, b) ((s32)((a) - (b)) < 0)
236 #define seq_after(a, b) ((s32)((a) - (b)) > 0)
239 static int ppp_unattached_ioctl(struct ppp_file
*pf
, struct file
*file
,
240 unsigned int cmd
, unsigned long arg
);
241 static void ppp_xmit_process(struct ppp
*ppp
);
242 static void ppp_send_frame(struct ppp
*ppp
, struct sk_buff
*skb
);
243 static void ppp_push(struct ppp
*ppp
);
244 static void ppp_channel_push(struct channel
*pch
);
245 static void ppp_receive_frame(struct ppp
*ppp
, struct sk_buff
*skb
,
246 struct channel
*pch
);
247 static void ppp_receive_error(struct ppp
*ppp
);
248 static void ppp_receive_nonmp_frame(struct ppp
*ppp
, struct sk_buff
*skb
);
249 static struct sk_buff
*ppp_decompress_frame(struct ppp
*ppp
,
250 struct sk_buff
*skb
);
251 #ifdef CONFIG_PPP_MULTILINK
252 static void ppp_receive_mp_frame(struct ppp
*ppp
, struct sk_buff
*skb
,
253 struct channel
*pch
);
254 static void ppp_mp_insert(struct ppp
*ppp
, struct sk_buff
*skb
);
255 static struct sk_buff
*ppp_mp_reconstruct(struct ppp
*ppp
);
256 static int ppp_mp_explode(struct ppp
*ppp
, struct sk_buff
*skb
);
257 #endif /* CONFIG_PPP_MULTILINK */
258 static int ppp_set_compress(struct ppp
*ppp
, unsigned long arg
);
259 static void ppp_ccp_peek(struct ppp
*ppp
, struct sk_buff
*skb
, int inbound
);
260 static void ppp_ccp_closed(struct ppp
*ppp
);
261 static struct compressor
*find_compressor(int type
);
262 static void ppp_get_stats(struct ppp
*ppp
, struct ppp_stats
*st
);
263 static struct ppp
*ppp_create_interface(int unit
, int *retp
);
264 static void init_ppp_file(struct ppp_file
*pf
, int kind
);
265 static void ppp_shutdown_interface(struct ppp
*ppp
);
266 static void ppp_destroy_interface(struct ppp
*ppp
);
267 static struct ppp
*ppp_find_unit(int unit
);
268 static struct channel
*ppp_find_channel(int unit
);
269 static int ppp_connect_channel(struct channel
*pch
, int unit
);
270 static int ppp_disconnect_channel(struct channel
*pch
);
271 static void ppp_destroy_channel(struct channel
*pch
);
273 static struct class *ppp_class
;
275 /* Translates a PPP protocol number to a NP index (NP == network protocol) */
276 static inline int proto_to_npindex(int proto
)
295 /* Translates an NP index into a PPP protocol number */
296 static const int npindex_to_proto
[NUM_NP
] = {
305 /* Translates an ethertype into an NP index */
306 static inline int ethertype_to_npindex(int ethertype
)
326 /* Translates an NP index into an ethertype */
327 static const int npindex_to_ethertype
[NUM_NP
] = {
339 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
340 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
341 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
342 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
343 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
344 ppp_recv_lock(ppp); } while (0)
345 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
346 ppp_xmit_unlock(ppp); } while (0)
349 * /dev/ppp device routines.
350 * The /dev/ppp device is used by pppd to control the ppp unit.
351 * It supports the read, write, ioctl and poll functions.
352 * Open instances of /dev/ppp can be in one of three states:
353 * unattached, attached to a ppp unit, or attached to a ppp channel.
355 static int ppp_open(struct inode
*inode
, struct file
*file
)
359 * This could (should?) be enforced by the permissions on /dev/ppp.
361 if (!capable(CAP_NET_ADMIN
))
366 static int ppp_release(struct inode
*inode
, struct file
*file
)
368 struct ppp_file
*pf
= file
->private_data
;
372 file
->private_data
= NULL
;
373 if (pf
->kind
== INTERFACE
) {
375 if (file
== ppp
->owner
)
376 ppp_shutdown_interface(ppp
);
378 if (atomic_dec_and_test(&pf
->refcnt
)) {
381 ppp_destroy_interface(PF_TO_PPP(pf
));
384 ppp_destroy_channel(PF_TO_CHANNEL(pf
));
392 static ssize_t
ppp_read(struct file
*file
, char __user
*buf
,
393 size_t count
, loff_t
*ppos
)
395 struct ppp_file
*pf
= file
->private_data
;
396 DECLARE_WAITQUEUE(wait
, current
);
398 struct sk_buff
*skb
= NULL
;
404 add_wait_queue(&pf
->rwait
, &wait
);
406 set_current_state(TASK_INTERRUPTIBLE
);
407 skb
= skb_dequeue(&pf
->rq
);
413 if (pf
->kind
== INTERFACE
) {
415 * Return 0 (EOF) on an interface that has no
416 * channels connected, unless it is looping
417 * network traffic (demand mode).
419 struct ppp
*ppp
= PF_TO_PPP(pf
);
420 if (ppp
->n_channels
== 0
421 && (ppp
->flags
& SC_LOOP_TRAFFIC
) == 0)
425 if (file
->f_flags
& O_NONBLOCK
)
428 if (signal_pending(current
))
432 set_current_state(TASK_RUNNING
);
433 remove_wait_queue(&pf
->rwait
, &wait
);
439 if (skb
->len
> count
)
442 if (copy_to_user(buf
, skb
->data
, skb
->len
))
452 static ssize_t
ppp_write(struct file
*file
, const char __user
*buf
,
453 size_t count
, loff_t
*ppos
)
455 struct ppp_file
*pf
= file
->private_data
;
462 skb
= alloc_skb(count
+ pf
->hdrlen
, GFP_KERNEL
);
465 skb_reserve(skb
, pf
->hdrlen
);
467 if (copy_from_user(skb_put(skb
, count
), buf
, count
)) {
472 skb_queue_tail(&pf
->xq
, skb
);
476 ppp_xmit_process(PF_TO_PPP(pf
));
479 ppp_channel_push(PF_TO_CHANNEL(pf
));
489 /* No kernel lock - fine */
490 static unsigned int ppp_poll(struct file
*file
, poll_table
*wait
)
492 struct ppp_file
*pf
= file
->private_data
;
497 poll_wait(file
, &pf
->rwait
, wait
);
498 mask
= POLLOUT
| POLLWRNORM
;
499 if (skb_peek(&pf
->rq
))
500 mask
|= POLLIN
| POLLRDNORM
;
503 else if (pf
->kind
== INTERFACE
) {
504 /* see comment in ppp_read */
505 struct ppp
*ppp
= PF_TO_PPP(pf
);
506 if (ppp
->n_channels
== 0
507 && (ppp
->flags
& SC_LOOP_TRAFFIC
) == 0)
508 mask
|= POLLIN
| POLLRDNORM
;
514 #ifdef CONFIG_PPP_FILTER
515 static int get_filter(void __user
*arg
, struct sock_filter
**p
)
517 struct sock_fprog uprog
;
518 struct sock_filter
*code
= NULL
;
521 if (copy_from_user(&uprog
, arg
, sizeof(uprog
)))
529 len
= uprog
.len
* sizeof(struct sock_filter
);
530 code
= kmalloc(len
, GFP_KERNEL
);
534 if (copy_from_user(code
, uprog
.filter
, len
)) {
539 err
= sk_chk_filter(code
, uprog
.len
);
548 #endif /* CONFIG_PPP_FILTER */
550 static int ppp_ioctl(struct inode
*inode
, struct file
*file
,
551 unsigned int cmd
, unsigned long arg
)
553 struct ppp_file
*pf
= file
->private_data
;
555 int err
= -EFAULT
, val
, val2
, i
;
556 struct ppp_idle idle
;
559 struct slcompress
*vj
;
560 void __user
*argp
= (void __user
*)arg
;
561 int __user
*p
= argp
;
564 return ppp_unattached_ioctl(pf
, file
, cmd
, arg
);
566 if (cmd
== PPPIOCDETACH
) {
568 * We have to be careful here... if the file descriptor
569 * has been dup'd, we could have another process in the
570 * middle of a poll using the same file *, so we had
571 * better not free the interface data structures -
572 * instead we fail the ioctl. Even in this case, we
573 * shut down the interface if we are the owner of it.
574 * Actually, we should get rid of PPPIOCDETACH, userland
575 * (i.e. pppd) could achieve the same effect by closing
576 * this fd and reopening /dev/ppp.
579 if (pf
->kind
== INTERFACE
) {
581 if (file
== ppp
->owner
)
582 ppp_shutdown_interface(ppp
);
584 if (atomic_read(&file
->f_count
) <= 2) {
585 ppp_release(inode
, file
);
588 printk(KERN_DEBUG
"PPPIOCDETACH file->f_count=%d\n",
589 atomic_read(&file
->f_count
));
593 if (pf
->kind
== CHANNEL
) {
594 struct channel
*pch
= PF_TO_CHANNEL(pf
);
595 struct ppp_channel
*chan
;
599 if (get_user(unit
, p
))
601 err
= ppp_connect_channel(pch
, unit
);
605 err
= ppp_disconnect_channel(pch
);
609 down_read(&pch
->chan_sem
);
612 if (chan
&& chan
->ops
->ioctl
)
613 err
= chan
->ops
->ioctl(chan
, cmd
, arg
);
614 up_read(&pch
->chan_sem
);
619 if (pf
->kind
!= INTERFACE
) {
621 printk(KERN_ERR
"PPP: not interface or channel??\n");
628 if (get_user(val
, p
))
635 if (get_user(val
, p
))
638 cflags
= ppp
->flags
& ~val
;
639 ppp
->flags
= val
& SC_FLAG_BITS
;
641 if (cflags
& SC_CCP_OPEN
)
647 val
= ppp
->flags
| ppp
->xstate
| ppp
->rstate
;
648 if (put_user(val
, p
))
653 case PPPIOCSCOMPRESS
:
654 err
= ppp_set_compress(ppp
, arg
);
658 if (put_user(ppp
->file
.index
, p
))
664 if (get_user(val
, p
))
671 if (put_user(ppp
->debug
, p
))
677 idle
.xmit_idle
= (jiffies
- ppp
->last_xmit
) / HZ
;
678 idle
.recv_idle
= (jiffies
- ppp
->last_recv
) / HZ
;
679 if (copy_to_user(argp
, &idle
, sizeof(idle
)))
685 if (get_user(val
, p
))
688 if ((val
>> 16) != 0) {
692 vj
= slhc_init(val2
+1, val
+1);
694 printk(KERN_ERR
"PPP: no memory (VJ compressor)\n");
708 if (copy_from_user(&npi
, argp
, sizeof(npi
)))
710 err
= proto_to_npindex(npi
.protocol
);
714 if (cmd
== PPPIOCGNPMODE
) {
716 npi
.mode
= ppp
->npmode
[i
];
717 if (copy_to_user(argp
, &npi
, sizeof(npi
)))
720 ppp
->npmode
[i
] = npi
.mode
;
721 /* we may be able to transmit more packets now (??) */
722 netif_wake_queue(ppp
->dev
);
727 #ifdef CONFIG_PPP_FILTER
730 struct sock_filter
*code
;
731 err
= get_filter(argp
, &code
);
734 kfree(ppp
->pass_filter
);
735 ppp
->pass_filter
= code
;
744 struct sock_filter
*code
;
745 err
= get_filter(argp
, &code
);
748 kfree(ppp
->active_filter
);
749 ppp
->active_filter
= code
;
750 ppp
->active_len
= err
;
756 #endif /* CONFIG_PPP_FILTER */
758 #ifdef CONFIG_PPP_MULTILINK
760 if (get_user(val
, p
))
764 ppp_recv_unlock(ppp
);
767 #endif /* CONFIG_PPP_MULTILINK */
776 static int ppp_unattached_ioctl(struct ppp_file
*pf
, struct file
*file
,
777 unsigned int cmd
, unsigned long arg
)
779 int unit
, err
= -EFAULT
;
781 struct channel
*chan
;
782 int __user
*p
= (int __user
*)arg
;
786 /* Create a new ppp unit */
787 if (get_user(unit
, p
))
789 ppp
= ppp_create_interface(unit
, &err
);
792 file
->private_data
= &ppp
->file
;
795 if (put_user(ppp
->file
.index
, p
))
801 /* Attach to an existing ppp unit */
802 if (get_user(unit
, p
))
804 mutex_lock(&all_ppp_mutex
);
806 ppp
= ppp_find_unit(unit
);
808 atomic_inc(&ppp
->file
.refcnt
);
809 file
->private_data
= &ppp
->file
;
812 mutex_unlock(&all_ppp_mutex
);
816 if (get_user(unit
, p
))
818 spin_lock_bh(&all_channels_lock
);
820 chan
= ppp_find_channel(unit
);
822 atomic_inc(&chan
->file
.refcnt
);
823 file
->private_data
= &chan
->file
;
826 spin_unlock_bh(&all_channels_lock
);
835 static const struct file_operations ppp_device_fops
= {
836 .owner
= THIS_MODULE
,
842 .release
= ppp_release
845 #define PPP_MAJOR 108
847 /* Called at boot time if ppp is compiled into the kernel,
848 or at module load time (from init_module) if compiled as a module. */
849 static int __init
ppp_init(void)
853 printk(KERN_INFO
"PPP generic driver version " PPP_VERSION
"\n");
854 err
= register_chrdev(PPP_MAJOR
, "ppp", &ppp_device_fops
);
856 ppp_class
= class_create(THIS_MODULE
, "ppp");
857 if (IS_ERR(ppp_class
)) {
858 err
= PTR_ERR(ppp_class
);
861 device_create(ppp_class
, NULL
, MKDEV(PPP_MAJOR
, 0), "ppp");
866 printk(KERN_ERR
"failed to register PPP device (%d)\n", err
);
870 unregister_chrdev(PPP_MAJOR
, "ppp");
875 * Network interface unit routines.
878 ppp_start_xmit(struct sk_buff
*skb
, struct net_device
*dev
)
880 struct ppp
*ppp
= (struct ppp
*) dev
->priv
;
884 npi
= ethertype_to_npindex(ntohs(skb
->protocol
));
888 /* Drop, accept or reject the packet */
889 switch (ppp
->npmode
[npi
]) {
893 /* it would be nice to have a way to tell the network
894 system to queue this one up for later. */
901 /* Put the 2-byte PPP protocol number on the front,
902 making sure there is room for the address and control fields. */
903 if (skb_cow_head(skb
, PPP_HDRLEN
))
906 pp
= skb_push(skb
, 2);
907 proto
= npindex_to_proto
[npi
];
911 netif_stop_queue(dev
);
912 skb_queue_tail(&ppp
->file
.xq
, skb
);
913 ppp_xmit_process(ppp
);
918 ++ppp
->dev
->stats
.tx_dropped
;
923 ppp_net_ioctl(struct net_device
*dev
, struct ifreq
*ifr
, int cmd
)
925 struct ppp
*ppp
= dev
->priv
;
927 void __user
*addr
= (void __user
*) ifr
->ifr_ifru
.ifru_data
;
928 struct ppp_stats stats
;
929 struct ppp_comp_stats cstats
;
934 ppp_get_stats(ppp
, &stats
);
935 if (copy_to_user(addr
, &stats
, sizeof(stats
)))
941 memset(&cstats
, 0, sizeof(cstats
));
943 ppp
->xcomp
->comp_stat(ppp
->xc_state
, &cstats
.c
);
945 ppp
->rcomp
->decomp_stat(ppp
->rc_state
, &cstats
.d
);
946 if (copy_to_user(addr
, &cstats
, sizeof(cstats
)))
953 if (copy_to_user(addr
, vers
, strlen(vers
) + 1))
965 static void ppp_setup(struct net_device
*dev
)
967 dev
->hard_header_len
= PPP_HDRLEN
;
970 dev
->tx_queue_len
= 3;
971 dev
->type
= ARPHRD_PPP
;
972 dev
->flags
= IFF_POINTOPOINT
| IFF_NOARP
| IFF_MULTICAST
;
976 * Transmit-side routines.
980 * Called to do any work queued up on the transmit side
981 * that can now be done.
984 ppp_xmit_process(struct ppp
*ppp
)
991 while (!ppp
->xmit_pending
992 && (skb
= skb_dequeue(&ppp
->file
.xq
)))
993 ppp_send_frame(ppp
, skb
);
994 /* If there's no work left to do, tell the core net
995 code that we can accept some more. */
996 if (!ppp
->xmit_pending
&& !skb_peek(&ppp
->file
.xq
))
997 netif_wake_queue(ppp
->dev
);
999 ppp_xmit_unlock(ppp
);
1002 static inline struct sk_buff
*
1003 pad_compress_skb(struct ppp
*ppp
, struct sk_buff
*skb
)
1005 struct sk_buff
*new_skb
;
1007 int new_skb_size
= ppp
->dev
->mtu
+
1008 ppp
->xcomp
->comp_extra
+ ppp
->dev
->hard_header_len
;
1009 int compressor_skb_size
= ppp
->dev
->mtu
+
1010 ppp
->xcomp
->comp_extra
+ PPP_HDRLEN
;
1011 new_skb
= alloc_skb(new_skb_size
, GFP_ATOMIC
);
1013 if (net_ratelimit())
1014 printk(KERN_ERR
"PPP: no memory (comp pkt)\n");
1017 if (ppp
->dev
->hard_header_len
> PPP_HDRLEN
)
1018 skb_reserve(new_skb
,
1019 ppp
->dev
->hard_header_len
- PPP_HDRLEN
);
1021 /* compressor still expects A/C bytes in hdr */
1022 len
= ppp
->xcomp
->compress(ppp
->xc_state
, skb
->data
- 2,
1023 new_skb
->data
, skb
->len
+ 2,
1024 compressor_skb_size
);
1025 if (len
> 0 && (ppp
->flags
& SC_CCP_UP
)) {
1029 skb_pull(skb
, 2); /* pull off A/C bytes */
1030 } else if (len
== 0) {
1031 /* didn't compress, or CCP not up yet */
1037 * MPPE requires that we do not send unencrypted
1038 * frames. The compressor will return -1 if we
1039 * should drop the frame. We cannot simply test
1040 * the compress_proto because MPPE and MPPC share
1043 if (net_ratelimit())
1044 printk(KERN_ERR
"ppp: compressor dropped pkt\n");
1053 * Compress and send a frame.
1054 * The caller should have locked the xmit path,
1055 * and xmit_pending should be 0.
1058 ppp_send_frame(struct ppp
*ppp
, struct sk_buff
*skb
)
1060 int proto
= PPP_PROTO(skb
);
1061 struct sk_buff
*new_skb
;
1065 if (proto
< 0x8000) {
1066 #ifdef CONFIG_PPP_FILTER
1067 /* check if we should pass this packet */
1068 /* the filter instructions are constructed assuming
1069 a four-byte PPP header on each packet */
1070 *skb_push(skb
, 2) = 1;
1071 if (ppp
->pass_filter
1072 && sk_run_filter(skb
, ppp
->pass_filter
,
1073 ppp
->pass_len
) == 0) {
1075 printk(KERN_DEBUG
"PPP: outbound frame not passed\n");
1079 /* if this packet passes the active filter, record the time */
1080 if (!(ppp
->active_filter
1081 && sk_run_filter(skb
, ppp
->active_filter
,
1082 ppp
->active_len
) == 0))
1083 ppp
->last_xmit
= jiffies
;
1086 /* for data packets, record the time */
1087 ppp
->last_xmit
= jiffies
;
1088 #endif /* CONFIG_PPP_FILTER */
1091 ++ppp
->dev
->stats
.tx_packets
;
1092 ppp
->dev
->stats
.tx_bytes
+= skb
->len
- 2;
1096 if (!ppp
->vj
|| (ppp
->flags
& SC_COMP_TCP
) == 0)
1098 /* try to do VJ TCP header compression */
1099 new_skb
= alloc_skb(skb
->len
+ ppp
->dev
->hard_header_len
- 2,
1102 printk(KERN_ERR
"PPP: no memory (VJ comp pkt)\n");
1105 skb_reserve(new_skb
, ppp
->dev
->hard_header_len
- 2);
1107 len
= slhc_compress(ppp
->vj
, cp
, skb
->len
- 2,
1108 new_skb
->data
+ 2, &cp
,
1109 !(ppp
->flags
& SC_NO_TCP_CCID
));
1110 if (cp
== skb
->data
+ 2) {
1111 /* didn't compress */
1114 if (cp
[0] & SL_TYPE_COMPRESSED_TCP
) {
1115 proto
= PPP_VJC_COMP
;
1116 cp
[0] &= ~SL_TYPE_COMPRESSED_TCP
;
1118 proto
= PPP_VJC_UNCOMP
;
1119 cp
[0] = skb
->data
[2];
1123 cp
= skb_put(skb
, len
+ 2);
1130 /* peek at outbound CCP frames */
1131 ppp_ccp_peek(ppp
, skb
, 0);
1135 /* try to do packet compression */
1136 if ((ppp
->xstate
& SC_COMP_RUN
) && ppp
->xc_state
1137 && proto
!= PPP_LCP
&& proto
!= PPP_CCP
) {
1138 if (!(ppp
->flags
& SC_CCP_UP
) && (ppp
->flags
& SC_MUST_COMP
)) {
1139 if (net_ratelimit())
1140 printk(KERN_ERR
"ppp: compression required but down - pkt dropped.\n");
1143 skb
= pad_compress_skb(ppp
, skb
);
1149 * If we are waiting for traffic (demand dialling),
1150 * queue it up for pppd to receive.
1152 if (ppp
->flags
& SC_LOOP_TRAFFIC
) {
1153 if (ppp
->file
.rq
.qlen
> PPP_MAX_RQLEN
)
1155 skb_queue_tail(&ppp
->file
.rq
, skb
);
1156 wake_up_interruptible(&ppp
->file
.rwait
);
1160 ppp
->xmit_pending
= skb
;
1167 ++ppp
->dev
->stats
.tx_errors
;
1171 * Try to send the frame in xmit_pending.
1172 * The caller should have the xmit path locked.
1175 ppp_push(struct ppp
*ppp
)
1177 struct list_head
*list
;
1178 struct channel
*pch
;
1179 struct sk_buff
*skb
= ppp
->xmit_pending
;
1184 list
= &ppp
->channels
;
1185 if (list_empty(list
)) {
1186 /* nowhere to send the packet, just drop it */
1187 ppp
->xmit_pending
= NULL
;
1192 if ((ppp
->flags
& SC_MULTILINK
) == 0) {
1193 /* not doing multilink: send it down the first channel */
1195 pch
= list_entry(list
, struct channel
, clist
);
1197 spin_lock_bh(&pch
->downl
);
1199 if (pch
->chan
->ops
->start_xmit(pch
->chan
, skb
))
1200 ppp
->xmit_pending
= NULL
;
1202 /* channel got unregistered */
1204 ppp
->xmit_pending
= NULL
;
1206 spin_unlock_bh(&pch
->downl
);
1210 #ifdef CONFIG_PPP_MULTILINK
1211 /* Multilink: fragment the packet over as many links
1212 as can take the packet at the moment. */
1213 if (!ppp_mp_explode(ppp
, skb
))
1215 #endif /* CONFIG_PPP_MULTILINK */
1217 ppp
->xmit_pending
= NULL
;
1221 #ifdef CONFIG_PPP_MULTILINK
1223 * Divide a packet to be transmitted into fragments and
1224 * send them out the individual links.
1226 static int ppp_mp_explode(struct ppp
*ppp
, struct sk_buff
*skb
)
1229 int i
, bits
, hdrlen
, mtu
;
1233 unsigned char *p
, *q
;
1234 struct list_head
*list
;
1235 struct channel
*pch
;
1236 struct sk_buff
*frag
;
1237 struct ppp_channel
*chan
;
1239 nfree
= 0; /* # channels which have no packet already queued */
1240 navail
= 0; /* total # of usable channels (not deregistered) */
1241 hdrlen
= (ppp
->flags
& SC_MP_XSHORTSEQ
)? MPHDRLEN_SSN
: MPHDRLEN
;
1243 list_for_each_entry(pch
, &ppp
->channels
, clist
) {
1244 navail
+= pch
->avail
= (pch
->chan
!= NULL
);
1246 if (skb_queue_empty(&pch
->file
.xq
) ||
1251 if (!pch
->had_frag
&& i
< ppp
->nxchan
)
1258 * Don't start sending this packet unless at least half of
1259 * the channels are free. This gives much better TCP
1260 * performance if we have a lot of channels.
1262 if (nfree
== 0 || nfree
< navail
/ 2)
1263 return 0; /* can't take now, leave it in xmit_pending */
1265 /* Do protocol field compression (XXX this should be optional) */
1274 * Decide on fragment size.
1275 * We create a fragment for each free channel regardless of
1276 * how small they are (i.e. even 0 length) in order to minimize
1277 * the time that it will take to detect when a channel drops
1282 fragsize
= DIV_ROUND_UP(fragsize
, nfree
);
1283 /* nbigger channels get fragsize bytes, the rest get fragsize-1,
1284 except if nbigger==0, then they all get fragsize. */
1285 nbigger
= len
% nfree
;
1287 /* skip to the channel after the one we last used
1288 and start at that one */
1289 list
= &ppp
->channels
;
1290 for (i
= 0; i
< ppp
->nxchan
; ++i
) {
1292 if (list
== &ppp
->channels
) {
1298 /* create a fragment for each channel */
1300 while (nfree
> 0 || len
> 0) {
1302 if (list
== &ppp
->channels
) {
1306 pch
= list_entry(list
, struct channel
, clist
);
1312 * Skip this channel if it has a fragment pending already and
1313 * we haven't given a fragment to all of the free channels.
1315 if (pch
->avail
== 1) {
1323 /* check the channel's mtu and whether it is still attached. */
1324 spin_lock_bh(&pch
->downl
);
1325 if (pch
->chan
== NULL
) {
1326 /* can't use this channel, it's being deregistered */
1327 spin_unlock_bh(&pch
->downl
);
1335 * Create a fragment for this channel of
1336 * min(max(mtu+2-hdrlen, 4), fragsize, len) bytes.
1337 * If mtu+2-hdrlen < 4, that is a ridiculously small
1338 * MTU, so we use mtu = 2 + hdrlen.
1343 mtu
= pch
->chan
->mtu
+ 2 - hdrlen
;
1348 if (flen
== len
&& nfree
== 0)
1350 frag
= alloc_skb(flen
+ hdrlen
+ (flen
== 0), GFP_ATOMIC
);
1353 q
= skb_put(frag
, flen
+ hdrlen
);
1355 /* make the MP header */
1358 if (ppp
->flags
& SC_MP_XSHORTSEQ
) {
1359 q
[2] = bits
+ ((ppp
->nxseq
>> 8) & 0xf);
1363 q
[3] = ppp
->nxseq
>> 16;
1364 q
[4] = ppp
->nxseq
>> 8;
1370 * Unfortunately there is a bug in older versions of
1371 * the Linux PPP multilink reconstruction code where it
1372 * drops 0-length fragments. Therefore we make sure the
1373 * fragment has at least one byte of data. Any bytes
1374 * we add in this situation will end up as padding on the
1375 * end of the reconstructed packet.
1378 *skb_put(frag
, 1) = 0;
1380 memcpy(q
+ hdrlen
, p
, flen
);
1382 /* try to send it down the channel */
1384 if (!skb_queue_empty(&pch
->file
.xq
) ||
1385 !chan
->ops
->start_xmit(chan
, frag
))
1386 skb_queue_tail(&pch
->file
.xq
, frag
);
1392 spin_unlock_bh(&pch
->downl
);
1394 if (--nbigger
== 0 && fragsize
> 0)
1402 spin_unlock_bh(&pch
->downl
);
1404 printk(KERN_ERR
"PPP: no memory (fragment)\n");
1405 ++ppp
->dev
->stats
.tx_errors
;
1407 return 1; /* abandon the frame */
1409 #endif /* CONFIG_PPP_MULTILINK */
1412 * Try to send data out on a channel.
1415 ppp_channel_push(struct channel
*pch
)
1417 struct sk_buff
*skb
;
1420 spin_lock_bh(&pch
->downl
);
1422 while (!skb_queue_empty(&pch
->file
.xq
)) {
1423 skb
= skb_dequeue(&pch
->file
.xq
);
1424 if (!pch
->chan
->ops
->start_xmit(pch
->chan
, skb
)) {
1425 /* put the packet back and try again later */
1426 skb_queue_head(&pch
->file
.xq
, skb
);
1431 /* channel got deregistered */
1432 skb_queue_purge(&pch
->file
.xq
);
1434 spin_unlock_bh(&pch
->downl
);
1435 /* see if there is anything from the attached unit to be sent */
1436 if (skb_queue_empty(&pch
->file
.xq
)) {
1437 read_lock_bh(&pch
->upl
);
1440 ppp_xmit_process(ppp
);
1441 read_unlock_bh(&pch
->upl
);
1446 * Receive-side routines.
1449 /* misuse a few fields of the skb for MP reconstruction */
1450 #define sequence priority
1451 #define BEbits cb[0]
1454 ppp_do_recv(struct ppp
*ppp
, struct sk_buff
*skb
, struct channel
*pch
)
1457 /* ppp->dev == 0 means interface is closing down */
1459 ppp_receive_frame(ppp
, skb
, pch
);
1462 ppp_recv_unlock(ppp
);
1466 ppp_input(struct ppp_channel
*chan
, struct sk_buff
*skb
)
1468 struct channel
*pch
= chan
->ppp
;
1471 if (!pch
|| skb
->len
== 0) {
1476 proto
= PPP_PROTO(skb
);
1477 read_lock_bh(&pch
->upl
);
1478 if (!pch
->ppp
|| proto
>= 0xc000 || proto
== PPP_CCPFRAG
) {
1479 /* put it on the channel queue */
1480 skb_queue_tail(&pch
->file
.rq
, skb
);
1481 /* drop old frames if queue too long */
1482 while (pch
->file
.rq
.qlen
> PPP_MAX_RQLEN
1483 && (skb
= skb_dequeue(&pch
->file
.rq
)))
1485 wake_up_interruptible(&pch
->file
.rwait
);
1487 ppp_do_recv(pch
->ppp
, skb
, pch
);
1489 read_unlock_bh(&pch
->upl
);
1492 /* Put a 0-length skb in the receive queue as an error indication */
1494 ppp_input_error(struct ppp_channel
*chan
, int code
)
1496 struct channel
*pch
= chan
->ppp
;
1497 struct sk_buff
*skb
;
1502 read_lock_bh(&pch
->upl
);
1504 skb
= alloc_skb(0, GFP_ATOMIC
);
1506 skb
->len
= 0; /* probably unnecessary */
1508 ppp_do_recv(pch
->ppp
, skb
, pch
);
1511 read_unlock_bh(&pch
->upl
);
1515 * We come in here to process a received frame.
1516 * The receive side of the ppp unit is locked.
1519 ppp_receive_frame(struct ppp
*ppp
, struct sk_buff
*skb
, struct channel
*pch
)
1521 if (pskb_may_pull(skb
, 2)) {
1522 #ifdef CONFIG_PPP_MULTILINK
1523 /* XXX do channel-level decompression here */
1524 if (PPP_PROTO(skb
) == PPP_MP
)
1525 ppp_receive_mp_frame(ppp
, skb
, pch
);
1527 #endif /* CONFIG_PPP_MULTILINK */
1528 ppp_receive_nonmp_frame(ppp
, skb
);
1533 /* note: a 0-length skb is used as an error indication */
1534 ++ppp
->dev
->stats
.rx_length_errors
;
1537 ppp_receive_error(ppp
);
1541 ppp_receive_error(struct ppp
*ppp
)
1543 ++ppp
->dev
->stats
.rx_errors
;
1549 ppp_receive_nonmp_frame(struct ppp
*ppp
, struct sk_buff
*skb
)
1552 int proto
, len
, npi
;
1555 * Decompress the frame, if compressed.
1556 * Note that some decompressors need to see uncompressed frames
1557 * that come in as well as compressed frames.
1559 if (ppp
->rc_state
&& (ppp
->rstate
& SC_DECOMP_RUN
)
1560 && (ppp
->rstate
& (SC_DC_FERROR
| SC_DC_ERROR
)) == 0)
1561 skb
= ppp_decompress_frame(ppp
, skb
);
1563 if (ppp
->flags
& SC_MUST_COMP
&& ppp
->rstate
& SC_DC_FERROR
)
1566 proto
= PPP_PROTO(skb
);
1569 /* decompress VJ compressed packets */
1570 if (!ppp
->vj
|| (ppp
->flags
& SC_REJ_COMP_TCP
))
1573 if (skb_tailroom(skb
) < 124 || skb_cloned(skb
)) {
1574 /* copy to a new sk_buff with more tailroom */
1575 ns
= dev_alloc_skb(skb
->len
+ 128);
1577 printk(KERN_ERR
"PPP: no memory (VJ decomp)\n");
1581 skb_copy_bits(skb
, 0, skb_put(ns
, skb
->len
), skb
->len
);
1586 skb
->ip_summed
= CHECKSUM_NONE
;
1588 len
= slhc_uncompress(ppp
->vj
, skb
->data
+ 2, skb
->len
- 2);
1590 printk(KERN_DEBUG
"PPP: VJ decompression error\n");
1595 skb_put(skb
, len
- skb
->len
);
1596 else if (len
< skb
->len
)
1601 case PPP_VJC_UNCOMP
:
1602 if (!ppp
->vj
|| (ppp
->flags
& SC_REJ_COMP_TCP
))
1605 /* Until we fix the decompressor need to make sure
1606 * data portion is linear.
1608 if (!pskb_may_pull(skb
, skb
->len
))
1611 if (slhc_remember(ppp
->vj
, skb
->data
+ 2, skb
->len
- 2) <= 0) {
1612 printk(KERN_ERR
"PPP: VJ uncompressed error\n");
1619 ppp_ccp_peek(ppp
, skb
, 1);
1623 ++ppp
->dev
->stats
.rx_packets
;
1624 ppp
->dev
->stats
.rx_bytes
+= skb
->len
- 2;
1626 npi
= proto_to_npindex(proto
);
1628 /* control or unknown frame - pass it to pppd */
1629 skb_queue_tail(&ppp
->file
.rq
, skb
);
1630 /* limit queue length by dropping old frames */
1631 while (ppp
->file
.rq
.qlen
> PPP_MAX_RQLEN
1632 && (skb
= skb_dequeue(&ppp
->file
.rq
)))
1634 /* wake up any process polling or blocking on read */
1635 wake_up_interruptible(&ppp
->file
.rwait
);
1638 /* network protocol frame - give it to the kernel */
1640 #ifdef CONFIG_PPP_FILTER
1641 /* check if the packet passes the pass and active filters */
1642 /* the filter instructions are constructed assuming
1643 a four-byte PPP header on each packet */
1644 if (ppp
->pass_filter
|| ppp
->active_filter
) {
1645 if (skb_cloned(skb
) &&
1646 pskb_expand_head(skb
, 0, 0, GFP_ATOMIC
))
1649 *skb_push(skb
, 2) = 0;
1650 if (ppp
->pass_filter
1651 && sk_run_filter(skb
, ppp
->pass_filter
,
1652 ppp
->pass_len
) == 0) {
1654 printk(KERN_DEBUG
"PPP: inbound frame "
1659 if (!(ppp
->active_filter
1660 && sk_run_filter(skb
, ppp
->active_filter
,
1661 ppp
->active_len
) == 0))
1662 ppp
->last_recv
= jiffies
;
1665 #endif /* CONFIG_PPP_FILTER */
1666 ppp
->last_recv
= jiffies
;
1668 if ((ppp
->dev
->flags
& IFF_UP
) == 0
1669 || ppp
->npmode
[npi
] != NPMODE_PASS
) {
1672 /* chop off protocol */
1673 skb_pull_rcsum(skb
, 2);
1674 skb
->dev
= ppp
->dev
;
1675 skb
->protocol
= htons(npindex_to_ethertype
[npi
]);
1676 skb_reset_mac_header(skb
);
1678 ppp
->dev
->last_rx
= jiffies
;
1685 ppp_receive_error(ppp
);
1688 static struct sk_buff
*
1689 ppp_decompress_frame(struct ppp
*ppp
, struct sk_buff
*skb
)
1691 int proto
= PPP_PROTO(skb
);
1695 /* Until we fix all the decompressor's need to make sure
1696 * data portion is linear.
1698 if (!pskb_may_pull(skb
, skb
->len
))
1701 if (proto
== PPP_COMP
) {
1704 switch(ppp
->rcomp
->compress_proto
) {
1706 obuff_size
= ppp
->mru
+ PPP_HDRLEN
+ 1;
1709 obuff_size
= ppp
->mru
+ PPP_HDRLEN
;
1713 ns
= dev_alloc_skb(obuff_size
);
1715 printk(KERN_ERR
"ppp_decompress_frame: no memory\n");
1718 /* the decompressor still expects the A/C bytes in the hdr */
1719 len
= ppp
->rcomp
->decompress(ppp
->rc_state
, skb
->data
- 2,
1720 skb
->len
+ 2, ns
->data
, obuff_size
);
1722 /* Pass the compressed frame to pppd as an
1723 error indication. */
1724 if (len
== DECOMP_FATALERROR
)
1725 ppp
->rstate
|= SC_DC_FERROR
;
1733 skb_pull(skb
, 2); /* pull off the A/C bytes */
1736 /* Uncompressed frame - pass to decompressor so it
1737 can update its dictionary if necessary. */
1738 if (ppp
->rcomp
->incomp
)
1739 ppp
->rcomp
->incomp(ppp
->rc_state
, skb
->data
- 2,
1746 ppp
->rstate
|= SC_DC_ERROR
;
1747 ppp_receive_error(ppp
);
1751 #ifdef CONFIG_PPP_MULTILINK
1753 * Receive a multilink frame.
1754 * We put it on the reconstruction queue and then pull off
1755 * as many completed frames as we can.
1758 ppp_receive_mp_frame(struct ppp
*ppp
, struct sk_buff
*skb
, struct channel
*pch
)
1762 int mphdrlen
= (ppp
->flags
& SC_MP_SHORTSEQ
)? MPHDRLEN_SSN
: MPHDRLEN
;
1764 if (!pskb_may_pull(skb
, mphdrlen
+ 1) || ppp
->mrru
== 0)
1765 goto err
; /* no good, throw it away */
1767 /* Decode sequence number and begin/end bits */
1768 if (ppp
->flags
& SC_MP_SHORTSEQ
) {
1769 seq
= ((skb
->data
[2] & 0x0f) << 8) | skb
->data
[3];
1772 seq
= (skb
->data
[3] << 16) | (skb
->data
[4] << 8)| skb
->data
[5];
1775 skb
->BEbits
= skb
->data
[2];
1776 skb_pull(skb
, mphdrlen
); /* pull off PPP and MP headers */
1779 * Do protocol ID decompression on the first fragment of each packet.
1781 if ((skb
->BEbits
& B
) && (skb
->data
[0] & 1))
1782 *skb_push(skb
, 1) = 0;
1785 * Expand sequence number to 32 bits, making it as close
1786 * as possible to ppp->minseq.
1788 seq
|= ppp
->minseq
& ~mask
;
1789 if ((int)(ppp
->minseq
- seq
) > (int)(mask
>> 1))
1791 else if ((int)(seq
- ppp
->minseq
) > (int)(mask
>> 1))
1792 seq
-= mask
+ 1; /* should never happen */
1793 skb
->sequence
= seq
;
1797 * If this packet comes before the next one we were expecting,
1800 if (seq_before(seq
, ppp
->nextseq
)) {
1802 ++ppp
->dev
->stats
.rx_dropped
;
1803 ppp_receive_error(ppp
);
1808 * Reevaluate minseq, the minimum over all channels of the
1809 * last sequence number received on each channel. Because of
1810 * the increasing sequence number rule, we know that any fragment
1811 * before `minseq' which hasn't arrived is never going to arrive.
1812 * The list of channels can't change because we have the receive
1813 * side of the ppp unit locked.
1815 list_for_each_entry(ch
, &ppp
->channels
, clist
) {
1816 if (seq_before(ch
->lastseq
, seq
))
1819 if (seq_before(ppp
->minseq
, seq
))
1822 /* Put the fragment on the reconstruction queue */
1823 ppp_mp_insert(ppp
, skb
);
1825 /* If the queue is getting long, don't wait any longer for packets
1826 before the start of the queue. */
1827 if (skb_queue_len(&ppp
->mrq
) >= PPP_MP_MAX_QLEN
1828 && seq_before(ppp
->minseq
, ppp
->mrq
.next
->sequence
))
1829 ppp
->minseq
= ppp
->mrq
.next
->sequence
;
1831 /* Pull completed packets off the queue and receive them. */
1832 while ((skb
= ppp_mp_reconstruct(ppp
)))
1833 ppp_receive_nonmp_frame(ppp
, skb
);
1839 ppp_receive_error(ppp
);
1843 * Insert a fragment on the MP reconstruction queue.
1844 * The queue is ordered by increasing sequence number.
1847 ppp_mp_insert(struct ppp
*ppp
, struct sk_buff
*skb
)
1850 struct sk_buff_head
*list
= &ppp
->mrq
;
1851 u32 seq
= skb
->sequence
;
1853 /* N.B. we don't need to lock the list lock because we have the
1854 ppp unit receive-side lock. */
1855 for (p
= list
->next
; p
!= (struct sk_buff
*)list
; p
= p
->next
)
1856 if (seq_before(seq
, p
->sequence
))
1858 __skb_insert(skb
, p
->prev
, p
, list
);
1862 * Reconstruct a packet from the MP fragment queue.
1863 * We go through increasing sequence numbers until we find a
1864 * complete packet, or we get to the sequence number for a fragment
1865 * which hasn't arrived but might still do so.
1867 static struct sk_buff
*
1868 ppp_mp_reconstruct(struct ppp
*ppp
)
1870 u32 seq
= ppp
->nextseq
;
1871 u32 minseq
= ppp
->minseq
;
1872 struct sk_buff_head
*list
= &ppp
->mrq
;
1873 struct sk_buff
*p
, *next
;
1874 struct sk_buff
*head
, *tail
;
1875 struct sk_buff
*skb
= NULL
;
1876 int lost
= 0, len
= 0;
1878 if (ppp
->mrru
== 0) /* do nothing until mrru is set */
1882 for (p
= head
; p
!= (struct sk_buff
*) list
; p
= next
) {
1884 if (seq_before(p
->sequence
, seq
)) {
1885 /* this can't happen, anyway ignore the skb */
1886 printk(KERN_ERR
"ppp_mp_reconstruct bad seq %u < %u\n",
1891 if (p
->sequence
!= seq
) {
1892 /* Fragment `seq' is missing. If it is after
1893 minseq, it might arrive later, so stop here. */
1894 if (seq_after(seq
, minseq
))
1896 /* Fragment `seq' is lost, keep going. */
1898 seq
= seq_before(minseq
, p
->sequence
)?
1899 minseq
+ 1: p
->sequence
;
1905 * At this point we know that all the fragments from
1906 * ppp->nextseq to seq are either present or lost.
1907 * Also, there are no complete packets in the queue
1908 * that have no missing fragments and end before this
1912 /* B bit set indicates this fragment starts a packet */
1913 if (p
->BEbits
& B
) {
1921 /* Got a complete packet yet? */
1922 if (lost
== 0 && (p
->BEbits
& E
) && (head
->BEbits
& B
)) {
1923 if (len
> ppp
->mrru
+ 2) {
1924 ++ppp
->dev
->stats
.rx_length_errors
;
1925 printk(KERN_DEBUG
"PPP: reconstructed packet"
1926 " is too long (%d)\n", len
);
1927 } else if (p
== head
) {
1928 /* fragment is complete packet - reuse skb */
1932 } else if ((skb
= dev_alloc_skb(len
)) == NULL
) {
1933 ++ppp
->dev
->stats
.rx_missed_errors
;
1934 printk(KERN_DEBUG
"PPP: no memory for "
1935 "reconstructed packet");
1940 ppp
->nextseq
= seq
+ 1;
1944 * If this is the ending fragment of a packet,
1945 * and we haven't found a complete valid packet yet,
1946 * we can discard up to and including this fragment.
1954 /* If we have a complete packet, copy it all into one skb. */
1956 /* If we have discarded any fragments,
1957 signal a receive error. */
1958 if (head
->sequence
!= ppp
->nextseq
) {
1960 printk(KERN_DEBUG
" missed pkts %u..%u\n",
1961 ppp
->nextseq
, head
->sequence
-1);
1962 ++ppp
->dev
->stats
.rx_dropped
;
1963 ppp_receive_error(ppp
);
1967 /* copy to a single skb */
1968 for (p
= head
; p
!= tail
->next
; p
= p
->next
)
1969 skb_copy_bits(p
, 0, skb_put(skb
, p
->len
), p
->len
);
1970 ppp
->nextseq
= tail
->sequence
+ 1;
1974 /* Discard all the skbuffs that we have copied the data out of
1975 or that we can't use. */
1976 while ((p
= list
->next
) != head
) {
1977 __skb_unlink(p
, list
);
1983 #endif /* CONFIG_PPP_MULTILINK */
1986 * Channel interface.
1990 * Create a new, unattached ppp channel.
1993 ppp_register_channel(struct ppp_channel
*chan
)
1995 struct channel
*pch
;
1997 pch
= kzalloc(sizeof(struct channel
), GFP_KERNEL
);
2003 init_ppp_file(&pch
->file
, CHANNEL
);
2004 pch
->file
.hdrlen
= chan
->hdrlen
;
2005 #ifdef CONFIG_PPP_MULTILINK
2007 #endif /* CONFIG_PPP_MULTILINK */
2008 init_rwsem(&pch
->chan_sem
);
2009 spin_lock_init(&pch
->downl
);
2010 rwlock_init(&pch
->upl
);
2011 spin_lock_bh(&all_channels_lock
);
2012 pch
->file
.index
= ++last_channel_index
;
2013 list_add(&pch
->list
, &new_channels
);
2014 atomic_inc(&channel_count
);
2015 spin_unlock_bh(&all_channels_lock
);
2020 * Return the index of a channel.
2022 int ppp_channel_index(struct ppp_channel
*chan
)
2024 struct channel
*pch
= chan
->ppp
;
2027 return pch
->file
.index
;
2032 * Return the PPP unit number to which a channel is connected.
2034 int ppp_unit_number(struct ppp_channel
*chan
)
2036 struct channel
*pch
= chan
->ppp
;
2040 read_lock_bh(&pch
->upl
);
2042 unit
= pch
->ppp
->file
.index
;
2043 read_unlock_bh(&pch
->upl
);
2049 * Disconnect a channel from the generic layer.
2050 * This must be called in process context.
2053 ppp_unregister_channel(struct ppp_channel
*chan
)
2055 struct channel
*pch
= chan
->ppp
;
2058 return; /* should never happen */
2062 * This ensures that we have returned from any calls into the
2063 * the channel's start_xmit or ioctl routine before we proceed.
2065 down_write(&pch
->chan_sem
);
2066 spin_lock_bh(&pch
->downl
);
2068 spin_unlock_bh(&pch
->downl
);
2069 up_write(&pch
->chan_sem
);
2070 ppp_disconnect_channel(pch
);
2071 spin_lock_bh(&all_channels_lock
);
2072 list_del(&pch
->list
);
2073 spin_unlock_bh(&all_channels_lock
);
2075 wake_up_interruptible(&pch
->file
.rwait
);
2076 if (atomic_dec_and_test(&pch
->file
.refcnt
))
2077 ppp_destroy_channel(pch
);
2081 * Callback from a channel when it can accept more to transmit.
2082 * This should be called at BH/softirq level, not interrupt level.
2085 ppp_output_wakeup(struct ppp_channel
*chan
)
2087 struct channel
*pch
= chan
->ppp
;
2091 ppp_channel_push(pch
);
2095 * Compression control.
2098 /* Process the PPPIOCSCOMPRESS ioctl. */
2100 ppp_set_compress(struct ppp
*ppp
, unsigned long arg
)
2103 struct compressor
*cp
, *ocomp
;
2104 struct ppp_option_data data
;
2105 void *state
, *ostate
;
2106 unsigned char ccp_option
[CCP_MAX_OPTION_LENGTH
];
2109 if (copy_from_user(&data
, (void __user
*) arg
, sizeof(data
))
2110 || (data
.length
<= CCP_MAX_OPTION_LENGTH
2111 && copy_from_user(ccp_option
, (void __user
*) data
.ptr
, data
.length
)))
2114 if (data
.length
> CCP_MAX_OPTION_LENGTH
2115 || ccp_option
[1] < 2 || ccp_option
[1] > data
.length
)
2118 cp
= find_compressor(ccp_option
[0]);
2121 request_module("ppp-compress-%d", ccp_option
[0]);
2122 cp
= find_compressor(ccp_option
[0]);
2124 #endif /* CONFIG_KMOD */
2129 if (data
.transmit
) {
2130 state
= cp
->comp_alloc(ccp_option
, data
.length
);
2133 ppp
->xstate
&= ~SC_COMP_RUN
;
2135 ostate
= ppp
->xc_state
;
2137 ppp
->xc_state
= state
;
2138 ppp_xmit_unlock(ppp
);
2140 ocomp
->comp_free(ostate
);
2141 module_put(ocomp
->owner
);
2145 module_put(cp
->owner
);
2148 state
= cp
->decomp_alloc(ccp_option
, data
.length
);
2151 ppp
->rstate
&= ~SC_DECOMP_RUN
;
2153 ostate
= ppp
->rc_state
;
2155 ppp
->rc_state
= state
;
2156 ppp_recv_unlock(ppp
);
2158 ocomp
->decomp_free(ostate
);
2159 module_put(ocomp
->owner
);
2163 module_put(cp
->owner
);
2171 * Look at a CCP packet and update our state accordingly.
2172 * We assume the caller has the xmit or recv path locked.
2175 ppp_ccp_peek(struct ppp
*ppp
, struct sk_buff
*skb
, int inbound
)
2180 if (!pskb_may_pull(skb
, CCP_HDRLEN
+ 2))
2181 return; /* no header */
2184 switch (CCP_CODE(dp
)) {
2187 /* A ConfReq starts negotiation of compression
2188 * in one direction of transmission,
2189 * and hence brings it down...but which way?
2192 * A ConfReq indicates what the sender would like to receive
2195 /* He is proposing what I should send */
2196 ppp
->xstate
&= ~SC_COMP_RUN
;
2198 /* I am proposing to what he should send */
2199 ppp
->rstate
&= ~SC_DECOMP_RUN
;
2206 * CCP is going down, both directions of transmission
2208 ppp
->rstate
&= ~SC_DECOMP_RUN
;
2209 ppp
->xstate
&= ~SC_COMP_RUN
;
2213 if ((ppp
->flags
& (SC_CCP_OPEN
| SC_CCP_UP
)) != SC_CCP_OPEN
)
2215 len
= CCP_LENGTH(dp
);
2216 if (!pskb_may_pull(skb
, len
+ 2))
2217 return; /* too short */
2220 if (len
< CCP_OPT_MINLEN
|| len
< CCP_OPT_LENGTH(dp
))
2223 /* we will start receiving compressed packets */
2226 if (ppp
->rcomp
->decomp_init(ppp
->rc_state
, dp
, len
,
2227 ppp
->file
.index
, 0, ppp
->mru
, ppp
->debug
)) {
2228 ppp
->rstate
|= SC_DECOMP_RUN
;
2229 ppp
->rstate
&= ~(SC_DC_ERROR
| SC_DC_FERROR
);
2232 /* we will soon start sending compressed packets */
2235 if (ppp
->xcomp
->comp_init(ppp
->xc_state
, dp
, len
,
2236 ppp
->file
.index
, 0, ppp
->debug
))
2237 ppp
->xstate
|= SC_COMP_RUN
;
2242 /* reset the [de]compressor */
2243 if ((ppp
->flags
& SC_CCP_UP
) == 0)
2246 if (ppp
->rc_state
&& (ppp
->rstate
& SC_DECOMP_RUN
)) {
2247 ppp
->rcomp
->decomp_reset(ppp
->rc_state
);
2248 ppp
->rstate
&= ~SC_DC_ERROR
;
2251 if (ppp
->xc_state
&& (ppp
->xstate
& SC_COMP_RUN
))
2252 ppp
->xcomp
->comp_reset(ppp
->xc_state
);
2258 /* Free up compression resources. */
2260 ppp_ccp_closed(struct ppp
*ppp
)
2262 void *xstate
, *rstate
;
2263 struct compressor
*xcomp
, *rcomp
;
2266 ppp
->flags
&= ~(SC_CCP_OPEN
| SC_CCP_UP
);
2269 xstate
= ppp
->xc_state
;
2270 ppp
->xc_state
= NULL
;
2273 rstate
= ppp
->rc_state
;
2274 ppp
->rc_state
= NULL
;
2278 xcomp
->comp_free(xstate
);
2279 module_put(xcomp
->owner
);
2282 rcomp
->decomp_free(rstate
);
2283 module_put(rcomp
->owner
);
2287 /* List of compressors. */
2288 static LIST_HEAD(compressor_list
);
2289 static DEFINE_SPINLOCK(compressor_list_lock
);
2291 struct compressor_entry
{
2292 struct list_head list
;
2293 struct compressor
*comp
;
2296 static struct compressor_entry
*
2297 find_comp_entry(int proto
)
2299 struct compressor_entry
*ce
;
2301 list_for_each_entry(ce
, &compressor_list
, list
) {
2302 if (ce
->comp
->compress_proto
== proto
)
2308 /* Register a compressor */
2310 ppp_register_compressor(struct compressor
*cp
)
2312 struct compressor_entry
*ce
;
2314 spin_lock(&compressor_list_lock
);
2316 if (find_comp_entry(cp
->compress_proto
))
2319 ce
= kmalloc(sizeof(struct compressor_entry
), GFP_ATOMIC
);
2324 list_add(&ce
->list
, &compressor_list
);
2326 spin_unlock(&compressor_list_lock
);
2330 /* Unregister a compressor */
2332 ppp_unregister_compressor(struct compressor
*cp
)
2334 struct compressor_entry
*ce
;
2336 spin_lock(&compressor_list_lock
);
2337 ce
= find_comp_entry(cp
->compress_proto
);
2338 if (ce
&& ce
->comp
== cp
) {
2339 list_del(&ce
->list
);
2342 spin_unlock(&compressor_list_lock
);
2345 /* Find a compressor. */
2346 static struct compressor
*
2347 find_compressor(int type
)
2349 struct compressor_entry
*ce
;
2350 struct compressor
*cp
= NULL
;
2352 spin_lock(&compressor_list_lock
);
2353 ce
= find_comp_entry(type
);
2356 if (!try_module_get(cp
->owner
))
2359 spin_unlock(&compressor_list_lock
);
2364 * Miscelleneous stuff.
2368 ppp_get_stats(struct ppp
*ppp
, struct ppp_stats
*st
)
2370 struct slcompress
*vj
= ppp
->vj
;
2372 memset(st
, 0, sizeof(*st
));
2373 st
->p
.ppp_ipackets
= ppp
->dev
->stats
.rx_packets
;
2374 st
->p
.ppp_ierrors
= ppp
->dev
->stats
.rx_errors
;
2375 st
->p
.ppp_ibytes
= ppp
->dev
->stats
.rx_bytes
;
2376 st
->p
.ppp_opackets
= ppp
->dev
->stats
.tx_packets
;
2377 st
->p
.ppp_oerrors
= ppp
->dev
->stats
.tx_errors
;
2378 st
->p
.ppp_obytes
= ppp
->dev
->stats
.tx_bytes
;
2381 st
->vj
.vjs_packets
= vj
->sls_o_compressed
+ vj
->sls_o_uncompressed
;
2382 st
->vj
.vjs_compressed
= vj
->sls_o_compressed
;
2383 st
->vj
.vjs_searches
= vj
->sls_o_searches
;
2384 st
->vj
.vjs_misses
= vj
->sls_o_misses
;
2385 st
->vj
.vjs_errorin
= vj
->sls_i_error
;
2386 st
->vj
.vjs_tossed
= vj
->sls_i_tossed
;
2387 st
->vj
.vjs_uncompressedin
= vj
->sls_i_uncompressed
;
2388 st
->vj
.vjs_compressedin
= vj
->sls_i_compressed
;
2392 * Stuff for handling the lists of ppp units and channels
2393 * and for initialization.
2397 * Create a new ppp interface unit. Fails if it can't allocate memory
2398 * or if there is already a unit with the requested number.
2399 * unit == -1 means allocate a new number.
2402 ppp_create_interface(int unit
, int *retp
)
2405 struct net_device
*dev
= NULL
;
2409 ppp
= kzalloc(sizeof(struct ppp
), GFP_KERNEL
);
2412 dev
= alloc_netdev(0, "", ppp_setup
);
2417 init_ppp_file(&ppp
->file
, INTERFACE
);
2418 ppp
->file
.hdrlen
= PPP_HDRLEN
- 2; /* don't count proto bytes */
2419 for (i
= 0; i
< NUM_NP
; ++i
)
2420 ppp
->npmode
[i
] = NPMODE_PASS
;
2421 INIT_LIST_HEAD(&ppp
->channels
);
2422 spin_lock_init(&ppp
->rlock
);
2423 spin_lock_init(&ppp
->wlock
);
2424 #ifdef CONFIG_PPP_MULTILINK
2426 skb_queue_head_init(&ppp
->mrq
);
2427 #endif /* CONFIG_PPP_MULTILINK */
2431 dev
->hard_start_xmit
= ppp_start_xmit
;
2432 dev
->do_ioctl
= ppp_net_ioctl
;
2435 mutex_lock(&all_ppp_mutex
);
2437 unit
= cardmap_find_first_free(all_ppp_units
);
2438 else if (cardmap_get(all_ppp_units
, unit
) != NULL
)
2439 goto out2
; /* unit already exists */
2441 /* Initialize the new ppp unit */
2442 ppp
->file
.index
= unit
;
2443 sprintf(dev
->name
, "ppp%d", unit
);
2445 ret
= register_netdev(dev
);
2447 printk(KERN_ERR
"PPP: couldn't register device %s (%d)\n",
2452 atomic_inc(&ppp_unit_count
);
2453 ret
= cardmap_set(&all_ppp_units
, unit
, ppp
);
2457 mutex_unlock(&all_ppp_mutex
);
2462 atomic_dec(&ppp_unit_count
);
2463 unregister_netdev(dev
);
2465 mutex_unlock(&all_ppp_mutex
);
2475 * Initialize a ppp_file structure.
2478 init_ppp_file(struct ppp_file
*pf
, int kind
)
2481 skb_queue_head_init(&pf
->xq
);
2482 skb_queue_head_init(&pf
->rq
);
2483 atomic_set(&pf
->refcnt
, 1);
2484 init_waitqueue_head(&pf
->rwait
);
2488 * Take down a ppp interface unit - called when the owning file
2489 * (the one that created the unit) is closed or detached.
2491 static void ppp_shutdown_interface(struct ppp
*ppp
)
2493 struct net_device
*dev
;
2495 mutex_lock(&all_ppp_mutex
);
2500 /* This will call dev_close() for us. */
2502 unregister_netdev(dev
);
2505 cardmap_set(&all_ppp_units
, ppp
->file
.index
, NULL
);
2508 wake_up_interruptible(&ppp
->file
.rwait
);
2509 mutex_unlock(&all_ppp_mutex
);
2513 * Free the memory used by a ppp unit. This is only called once
2514 * there are no channels connected to the unit and no file structs
2515 * that reference the unit.
2517 static void ppp_destroy_interface(struct ppp
*ppp
)
2519 atomic_dec(&ppp_unit_count
);
2521 if (!ppp
->file
.dead
|| ppp
->n_channels
) {
2522 /* "can't happen" */
2523 printk(KERN_ERR
"ppp: destroying ppp struct %p but dead=%d "
2524 "n_channels=%d !\n", ppp
, ppp
->file
.dead
,
2529 ppp_ccp_closed(ppp
);
2534 skb_queue_purge(&ppp
->file
.xq
);
2535 skb_queue_purge(&ppp
->file
.rq
);
2536 #ifdef CONFIG_PPP_MULTILINK
2537 skb_queue_purge(&ppp
->mrq
);
2538 #endif /* CONFIG_PPP_MULTILINK */
2539 #ifdef CONFIG_PPP_FILTER
2540 kfree(ppp
->pass_filter
);
2541 ppp
->pass_filter
= NULL
;
2542 kfree(ppp
->active_filter
);
2543 ppp
->active_filter
= NULL
;
2544 #endif /* CONFIG_PPP_FILTER */
2546 if (ppp
->xmit_pending
)
2547 kfree_skb(ppp
->xmit_pending
);
2553 * Locate an existing ppp unit.
2554 * The caller should have locked the all_ppp_mutex.
2557 ppp_find_unit(int unit
)
2559 return cardmap_get(all_ppp_units
, unit
);
2563 * Locate an existing ppp channel.
2564 * The caller should have locked the all_channels_lock.
2565 * First we look in the new_channels list, then in the
2566 * all_channels list. If found in the new_channels list,
2567 * we move it to the all_channels list. This is for speed
2568 * when we have a lot of channels in use.
2570 static struct channel
*
2571 ppp_find_channel(int unit
)
2573 struct channel
*pch
;
2575 list_for_each_entry(pch
, &new_channels
, list
) {
2576 if (pch
->file
.index
== unit
) {
2577 list_move(&pch
->list
, &all_channels
);
2581 list_for_each_entry(pch
, &all_channels
, list
) {
2582 if (pch
->file
.index
== unit
)
2589 * Connect a PPP channel to a PPP interface unit.
2592 ppp_connect_channel(struct channel
*pch
, int unit
)
2598 mutex_lock(&all_ppp_mutex
);
2599 ppp
= ppp_find_unit(unit
);
2602 write_lock_bh(&pch
->upl
);
2608 if (pch
->file
.hdrlen
> ppp
->file
.hdrlen
)
2609 ppp
->file
.hdrlen
= pch
->file
.hdrlen
;
2610 hdrlen
= pch
->file
.hdrlen
+ 2; /* for protocol bytes */
2611 if (ppp
->dev
&& hdrlen
> ppp
->dev
->hard_header_len
)
2612 ppp
->dev
->hard_header_len
= hdrlen
;
2613 list_add_tail(&pch
->clist
, &ppp
->channels
);
2616 atomic_inc(&ppp
->file
.refcnt
);
2621 write_unlock_bh(&pch
->upl
);
2623 mutex_unlock(&all_ppp_mutex
);
2628 * Disconnect a channel from its ppp unit.
2631 ppp_disconnect_channel(struct channel
*pch
)
2636 write_lock_bh(&pch
->upl
);
2639 write_unlock_bh(&pch
->upl
);
2641 /* remove it from the ppp unit's list */
2643 list_del(&pch
->clist
);
2644 if (--ppp
->n_channels
== 0)
2645 wake_up_interruptible(&ppp
->file
.rwait
);
2647 if (atomic_dec_and_test(&ppp
->file
.refcnt
))
2648 ppp_destroy_interface(ppp
);
2655 * Free up the resources used by a ppp channel.
2657 static void ppp_destroy_channel(struct channel
*pch
)
2659 atomic_dec(&channel_count
);
2661 if (!pch
->file
.dead
) {
2662 /* "can't happen" */
2663 printk(KERN_ERR
"ppp: destroying undead channel %p !\n",
2667 skb_queue_purge(&pch
->file
.xq
);
2668 skb_queue_purge(&pch
->file
.rq
);
2672 static void __exit
ppp_cleanup(void)
2674 /* should never happen */
2675 if (atomic_read(&ppp_unit_count
) || atomic_read(&channel_count
))
2676 printk(KERN_ERR
"PPP: removing module but units remain!\n");
2677 cardmap_destroy(&all_ppp_units
);
2678 unregister_chrdev(PPP_MAJOR
, "ppp");
2679 device_destroy(ppp_class
, MKDEV(PPP_MAJOR
, 0));
2680 class_destroy(ppp_class
);
2684 * Cardmap implementation.
2686 static void *cardmap_get(struct cardmap
*map
, unsigned int nr
)
2691 for (p
= map
; p
!= NULL
; ) {
2692 if ((i
= nr
>> p
->shift
) >= CARDMAP_WIDTH
)
2696 nr
&= ~(CARDMAP_MASK
<< p
->shift
);
2702 static int cardmap_set(struct cardmap
**pmap
, unsigned int nr
, void *ptr
)
2708 if (p
== NULL
|| (nr
>> p
->shift
) >= CARDMAP_WIDTH
) {
2710 /* need a new top level */
2711 struct cardmap
*np
= kzalloc(sizeof(*np
), GFP_KERNEL
);
2716 np
->shift
= p
->shift
+ CARDMAP_ORDER
;
2721 } while ((nr
>> p
->shift
) >= CARDMAP_WIDTH
);
2724 while (p
->shift
> 0) {
2725 i
= (nr
>> p
->shift
) & CARDMAP_MASK
;
2726 if (p
->ptr
[i
] == NULL
) {
2727 struct cardmap
*np
= kzalloc(sizeof(*np
), GFP_KERNEL
);
2730 np
->shift
= p
->shift
- CARDMAP_ORDER
;
2735 clear_bit(i
, &p
->inuse
);
2738 i
= nr
& CARDMAP_MASK
;
2741 set_bit(i
, &p
->inuse
);
2743 clear_bit(i
, &p
->inuse
);
2749 static unsigned int cardmap_find_first_free(struct cardmap
*map
)
2752 unsigned int nr
= 0;
2755 if ((p
= map
) == NULL
)
2758 i
= find_first_zero_bit(&p
->inuse
, CARDMAP_WIDTH
);
2759 if (i
>= CARDMAP_WIDTH
) {
2760 if (p
->parent
== NULL
)
2761 return CARDMAP_WIDTH
<< p
->shift
;
2763 i
= (nr
>> p
->shift
) & CARDMAP_MASK
;
2764 set_bit(i
, &p
->inuse
);
2767 nr
= (nr
& (~CARDMAP_MASK
<< p
->shift
)) | (i
<< p
->shift
);
2768 if (p
->shift
== 0 || p
->ptr
[i
] == NULL
)
2774 static void cardmap_destroy(struct cardmap
**pmap
)
2776 struct cardmap
*p
, *np
;
2779 for (p
= *pmap
; p
!= NULL
; p
= np
) {
2780 if (p
->shift
!= 0) {
2781 for (i
= 0; i
< CARDMAP_WIDTH
; ++i
)
2782 if (p
->ptr
[i
] != NULL
)
2784 if (i
< CARDMAP_WIDTH
) {
2796 /* Module/initialization stuff */
2798 module_init(ppp_init
);
2799 module_exit(ppp_cleanup
);
2801 EXPORT_SYMBOL(ppp_register_channel
);
2802 EXPORT_SYMBOL(ppp_unregister_channel
);
2803 EXPORT_SYMBOL(ppp_channel_index
);
2804 EXPORT_SYMBOL(ppp_unit_number
);
2805 EXPORT_SYMBOL(ppp_input
);
2806 EXPORT_SYMBOL(ppp_input_error
);
2807 EXPORT_SYMBOL(ppp_output_wakeup
);
2808 EXPORT_SYMBOL(ppp_register_compressor
);
2809 EXPORT_SYMBOL(ppp_unregister_compressor
);
2810 MODULE_LICENSE("GPL");
2811 MODULE_ALIAS_CHARDEV_MAJOR(PPP_MAJOR
);
2812 MODULE_ALIAS("/dev/ppp");