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/idr.h>
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>
42 #include <linux/tcp.h>
43 #include <linux/smp_lock.h>
44 #include <linux/spinlock.h>
45 #include <linux/rwsem.h>
46 #include <linux/stddef.h>
47 #include <linux/device.h>
48 #include <linux/mutex.h>
49 #include <net/slhc_vj.h>
50 #include <asm/atomic.h>
52 #include <linux/nsproxy.h>
53 #include <net/net_namespace.h>
54 #include <net/netns/generic.h>
56 #define PPP_VERSION "2.4.2"
59 * Network protocols we support.
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. */
69 #define MPHDRLEN 6 /* multilink protocol header length */
70 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */
71 #define MIN_FRAG_SIZE 64
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.
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 */
91 #define PF_TO_X(pf, X) container_of(pf, X, file)
93 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
94 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
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.
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 */
124 int closing
; /* is device closing down? a8 */
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 */
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 */
138 struct net
*ppp_net
; /* the net we belong to */
142 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
143 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
145 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
146 * Bits in xstate: SC_COMP_RUN
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 \
150 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
153 * Private data structure for each channel.
154 * This includes the data structure used for multilink.
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 */
163 struct net
*chan_net
; /* the net channel belongs to */
164 struct list_head clist
; /* link in list of channels per unit */
165 rwlock_t upl
; /* protects `ppp' */
166 #ifdef CONFIG_PPP_MULTILINK
167 u8 avail
; /* flag used in multilink stuff */
168 u8 had_frag
; /* >= 1 fragments have been sent */
169 u32 lastseq
; /* MP: last sequence # received */
170 #endif /* CONFIG_PPP_MULTILINK */
174 * SMP locking issues:
175 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
176 * list and the ppp.n_channels field, you need to take both locks
177 * before you modify them.
178 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
182 static atomic_t ppp_unit_count
= ATOMIC_INIT(0);
183 static atomic_t channel_count
= ATOMIC_INIT(0);
185 /* per-net private data for this module */
186 static unsigned int ppp_net_id
;
188 /* units to ppp mapping */
189 struct idr units_idr
;
192 * all_ppp_mutex protects the units_idr mapping.
193 * It also ensures that finding a ppp unit in the units_idr
194 * map and updating its file.refcnt field is atomic.
196 struct mutex all_ppp_mutex
;
199 struct list_head all_channels
;
200 struct list_head new_channels
;
201 int last_channel_index
;
204 * all_channels_lock protects all_channels and
205 * last_channel_index, and the atomicity of find
206 * a channel and updating its file.refcnt field.
208 spinlock_t all_channels_lock
;
211 /* Get the PPP protocol number from a skb */
212 #define PPP_PROTO(skb) (((skb)->data[0] << 8) + (skb)->data[1])
214 /* We limit the length of ppp->file.rq to this (arbitrary) value */
215 #define PPP_MAX_RQLEN 32
218 * Maximum number of multilink fragments queued up.
219 * This has to be large enough to cope with the maximum latency of
220 * the slowest channel relative to the others. Strictly it should
221 * depend on the number of channels and their characteristics.
223 #define PPP_MP_MAX_QLEN 128
225 /* Multilink header bits. */
226 #define B 0x80 /* this fragment begins a packet */
227 #define E 0x40 /* this fragment ends a packet */
229 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */
230 #define seq_before(a, b) ((s32)((a) - (b)) < 0)
231 #define seq_after(a, b) ((s32)((a) - (b)) > 0)
234 static int ppp_unattached_ioctl(struct net
*net
, struct ppp_file
*pf
,
235 struct file
*file
, unsigned int cmd
, unsigned long arg
);
236 static void ppp_xmit_process(struct ppp
*ppp
);
237 static void ppp_send_frame(struct ppp
*ppp
, struct sk_buff
*skb
);
238 static void ppp_push(struct ppp
*ppp
);
239 static void ppp_channel_push(struct channel
*pch
);
240 static void ppp_receive_frame(struct ppp
*ppp
, struct sk_buff
*skb
,
241 struct channel
*pch
);
242 static void ppp_receive_error(struct ppp
*ppp
);
243 static void ppp_receive_nonmp_frame(struct ppp
*ppp
, struct sk_buff
*skb
);
244 static struct sk_buff
*ppp_decompress_frame(struct ppp
*ppp
,
245 struct sk_buff
*skb
);
246 #ifdef CONFIG_PPP_MULTILINK
247 static void ppp_receive_mp_frame(struct ppp
*ppp
, struct sk_buff
*skb
,
248 struct channel
*pch
);
249 static void ppp_mp_insert(struct ppp
*ppp
, struct sk_buff
*skb
);
250 static struct sk_buff
*ppp_mp_reconstruct(struct ppp
*ppp
);
251 static int ppp_mp_explode(struct ppp
*ppp
, struct sk_buff
*skb
);
252 #endif /* CONFIG_PPP_MULTILINK */
253 static int ppp_set_compress(struct ppp
*ppp
, unsigned long arg
);
254 static void ppp_ccp_peek(struct ppp
*ppp
, struct sk_buff
*skb
, int inbound
);
255 static void ppp_ccp_closed(struct ppp
*ppp
);
256 static struct compressor
*find_compressor(int type
);
257 static void ppp_get_stats(struct ppp
*ppp
, struct ppp_stats
*st
);
258 static struct ppp
*ppp_create_interface(struct net
*net
, int unit
, int *retp
);
259 static void init_ppp_file(struct ppp_file
*pf
, int kind
);
260 static void ppp_shutdown_interface(struct ppp
*ppp
);
261 static void ppp_destroy_interface(struct ppp
*ppp
);
262 static struct ppp
*ppp_find_unit(struct ppp_net
*pn
, int unit
);
263 static struct channel
*ppp_find_channel(struct ppp_net
*pn
, int unit
);
264 static int ppp_connect_channel(struct channel
*pch
, int unit
);
265 static int ppp_disconnect_channel(struct channel
*pch
);
266 static void ppp_destroy_channel(struct channel
*pch
);
267 static int unit_get(struct idr
*p
, void *ptr
);
268 static int unit_set(struct idr
*p
, void *ptr
, int n
);
269 static void unit_put(struct idr
*p
, int n
);
270 static void *unit_find(struct idr
*p
, int n
);
272 static struct class *ppp_class
;
274 /* per net-namespace data */
275 static inline struct ppp_net
*ppp_pernet(struct net
*net
)
279 return net_generic(net
, ppp_net_id
);
282 /* Translates a PPP protocol number to a NP index (NP == network protocol) */
283 static inline int proto_to_npindex(int proto
)
302 /* Translates an NP index into a PPP protocol number */
303 static const int npindex_to_proto
[NUM_NP
] = {
312 /* Translates an ethertype into an NP index */
313 static inline int ethertype_to_npindex(int ethertype
)
333 /* Translates an NP index into an ethertype */
334 static const int npindex_to_ethertype
[NUM_NP
] = {
346 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
347 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
348 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
349 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
350 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
351 ppp_recv_lock(ppp); } while (0)
352 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
353 ppp_xmit_unlock(ppp); } while (0)
356 * /dev/ppp device routines.
357 * The /dev/ppp device is used by pppd to control the ppp unit.
358 * It supports the read, write, ioctl and poll functions.
359 * Open instances of /dev/ppp can be in one of three states:
360 * unattached, attached to a ppp unit, or attached to a ppp channel.
362 static int ppp_open(struct inode
*inode
, struct file
*file
)
366 * This could (should?) be enforced by the permissions on /dev/ppp.
368 if (!capable(CAP_NET_ADMIN
))
373 static int ppp_release(struct inode
*unused
, struct file
*file
)
375 struct ppp_file
*pf
= file
->private_data
;
379 file
->private_data
= NULL
;
380 if (pf
->kind
== INTERFACE
) {
382 if (file
== ppp
->owner
)
383 ppp_shutdown_interface(ppp
);
385 if (atomic_dec_and_test(&pf
->refcnt
)) {
388 ppp_destroy_interface(PF_TO_PPP(pf
));
391 ppp_destroy_channel(PF_TO_CHANNEL(pf
));
399 static ssize_t
ppp_read(struct file
*file
, char __user
*buf
,
400 size_t count
, loff_t
*ppos
)
402 struct ppp_file
*pf
= file
->private_data
;
403 DECLARE_WAITQUEUE(wait
, current
);
405 struct sk_buff
*skb
= NULL
;
411 add_wait_queue(&pf
->rwait
, &wait
);
413 set_current_state(TASK_INTERRUPTIBLE
);
414 skb
= skb_dequeue(&pf
->rq
);
420 if (pf
->kind
== INTERFACE
) {
422 * Return 0 (EOF) on an interface that has no
423 * channels connected, unless it is looping
424 * network traffic (demand mode).
426 struct ppp
*ppp
= PF_TO_PPP(pf
);
427 if (ppp
->n_channels
== 0
428 && (ppp
->flags
& SC_LOOP_TRAFFIC
) == 0)
432 if (file
->f_flags
& O_NONBLOCK
)
435 if (signal_pending(current
))
439 set_current_state(TASK_RUNNING
);
440 remove_wait_queue(&pf
->rwait
, &wait
);
446 if (skb
->len
> count
)
449 if (copy_to_user(buf
, skb
->data
, skb
->len
))
459 static ssize_t
ppp_write(struct file
*file
, const char __user
*buf
,
460 size_t count
, loff_t
*ppos
)
462 struct ppp_file
*pf
= file
->private_data
;
469 skb
= alloc_skb(count
+ pf
->hdrlen
, GFP_KERNEL
);
472 skb_reserve(skb
, pf
->hdrlen
);
474 if (copy_from_user(skb_put(skb
, count
), buf
, count
)) {
479 skb_queue_tail(&pf
->xq
, skb
);
483 ppp_xmit_process(PF_TO_PPP(pf
));
486 ppp_channel_push(PF_TO_CHANNEL(pf
));
496 /* No kernel lock - fine */
497 static unsigned int ppp_poll(struct file
*file
, poll_table
*wait
)
499 struct ppp_file
*pf
= file
->private_data
;
504 poll_wait(file
, &pf
->rwait
, wait
);
505 mask
= POLLOUT
| POLLWRNORM
;
506 if (skb_peek(&pf
->rq
))
507 mask
|= POLLIN
| POLLRDNORM
;
510 else if (pf
->kind
== INTERFACE
) {
511 /* see comment in ppp_read */
512 struct ppp
*ppp
= PF_TO_PPP(pf
);
513 if (ppp
->n_channels
== 0
514 && (ppp
->flags
& SC_LOOP_TRAFFIC
) == 0)
515 mask
|= POLLIN
| POLLRDNORM
;
521 #ifdef CONFIG_PPP_FILTER
522 static int get_filter(void __user
*arg
, struct sock_filter
**p
)
524 struct sock_fprog uprog
;
525 struct sock_filter
*code
= NULL
;
528 if (copy_from_user(&uprog
, arg
, sizeof(uprog
)))
536 len
= uprog
.len
* sizeof(struct sock_filter
);
537 code
= kmalloc(len
, GFP_KERNEL
);
541 if (copy_from_user(code
, uprog
.filter
, len
)) {
546 err
= sk_chk_filter(code
, uprog
.len
);
555 #endif /* CONFIG_PPP_FILTER */
557 static long ppp_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
559 struct ppp_file
*pf
= file
->private_data
;
561 int err
= -EFAULT
, val
, val2
, i
;
562 struct ppp_idle idle
;
565 struct slcompress
*vj
;
566 void __user
*argp
= (void __user
*)arg
;
567 int __user
*p
= argp
;
570 return ppp_unattached_ioctl(current
->nsproxy
->net_ns
,
573 if (cmd
== PPPIOCDETACH
) {
575 * We have to be careful here... if the file descriptor
576 * has been dup'd, we could have another process in the
577 * middle of a poll using the same file *, so we had
578 * better not free the interface data structures -
579 * instead we fail the ioctl. Even in this case, we
580 * shut down the interface if we are the owner of it.
581 * Actually, we should get rid of PPPIOCDETACH, userland
582 * (i.e. pppd) could achieve the same effect by closing
583 * this fd and reopening /dev/ppp.
587 if (pf
->kind
== INTERFACE
) {
589 if (file
== ppp
->owner
)
590 ppp_shutdown_interface(ppp
);
592 if (atomic_long_read(&file
->f_count
) <= 2) {
593 ppp_release(NULL
, file
);
596 printk(KERN_DEBUG
"PPPIOCDETACH file->f_count=%ld\n",
597 atomic_long_read(&file
->f_count
));
602 if (pf
->kind
== CHANNEL
) {
604 struct ppp_channel
*chan
;
607 pch
= PF_TO_CHANNEL(pf
);
611 if (get_user(unit
, p
))
613 err
= ppp_connect_channel(pch
, unit
);
617 err
= ppp_disconnect_channel(pch
);
621 down_read(&pch
->chan_sem
);
624 if (chan
&& chan
->ops
->ioctl
)
625 err
= chan
->ops
->ioctl(chan
, cmd
, arg
);
626 up_read(&pch
->chan_sem
);
632 if (pf
->kind
!= INTERFACE
) {
634 printk(KERN_ERR
"PPP: not interface or channel??\n");
642 if (get_user(val
, p
))
649 if (get_user(val
, p
))
652 cflags
= ppp
->flags
& ~val
;
653 ppp
->flags
= val
& SC_FLAG_BITS
;
655 if (cflags
& SC_CCP_OPEN
)
661 val
= ppp
->flags
| ppp
->xstate
| ppp
->rstate
;
662 if (put_user(val
, p
))
667 case PPPIOCSCOMPRESS
:
668 err
= ppp_set_compress(ppp
, arg
);
672 if (put_user(ppp
->file
.index
, p
))
678 if (get_user(val
, p
))
685 if (put_user(ppp
->debug
, p
))
691 idle
.xmit_idle
= (jiffies
- ppp
->last_xmit
) / HZ
;
692 idle
.recv_idle
= (jiffies
- ppp
->last_recv
) / HZ
;
693 if (copy_to_user(argp
, &idle
, sizeof(idle
)))
699 if (get_user(val
, p
))
702 if ((val
>> 16) != 0) {
706 vj
= slhc_init(val2
+1, val
+1);
708 printk(KERN_ERR
"PPP: no memory (VJ compressor)\n");
722 if (copy_from_user(&npi
, argp
, sizeof(npi
)))
724 err
= proto_to_npindex(npi
.protocol
);
728 if (cmd
== PPPIOCGNPMODE
) {
730 npi
.mode
= ppp
->npmode
[i
];
731 if (copy_to_user(argp
, &npi
, sizeof(npi
)))
734 ppp
->npmode
[i
] = npi
.mode
;
735 /* we may be able to transmit more packets now (??) */
736 netif_wake_queue(ppp
->dev
);
741 #ifdef CONFIG_PPP_FILTER
744 struct sock_filter
*code
;
745 err
= get_filter(argp
, &code
);
748 kfree(ppp
->pass_filter
);
749 ppp
->pass_filter
= code
;
758 struct sock_filter
*code
;
759 err
= get_filter(argp
, &code
);
762 kfree(ppp
->active_filter
);
763 ppp
->active_filter
= code
;
764 ppp
->active_len
= err
;
770 #endif /* CONFIG_PPP_FILTER */
772 #ifdef CONFIG_PPP_MULTILINK
774 if (get_user(val
, p
))
778 ppp_recv_unlock(ppp
);
781 #endif /* CONFIG_PPP_MULTILINK */
790 static int ppp_unattached_ioctl(struct net
*net
, struct ppp_file
*pf
,
791 struct file
*file
, unsigned int cmd
, unsigned long arg
)
793 int unit
, err
= -EFAULT
;
795 struct channel
*chan
;
797 int __user
*p
= (int __user
*)arg
;
802 /* Create a new ppp unit */
803 if (get_user(unit
, p
))
805 ppp
= ppp_create_interface(net
, unit
, &err
);
808 file
->private_data
= &ppp
->file
;
811 if (put_user(ppp
->file
.index
, p
))
817 /* Attach to an existing ppp unit */
818 if (get_user(unit
, p
))
821 pn
= ppp_pernet(net
);
822 mutex_lock(&pn
->all_ppp_mutex
);
823 ppp
= ppp_find_unit(pn
, unit
);
825 atomic_inc(&ppp
->file
.refcnt
);
826 file
->private_data
= &ppp
->file
;
829 mutex_unlock(&pn
->all_ppp_mutex
);
833 if (get_user(unit
, p
))
836 pn
= ppp_pernet(net
);
837 spin_lock_bh(&pn
->all_channels_lock
);
838 chan
= ppp_find_channel(pn
, unit
);
840 atomic_inc(&chan
->file
.refcnt
);
841 file
->private_data
= &chan
->file
;
844 spin_unlock_bh(&pn
->all_channels_lock
);
854 static const struct file_operations ppp_device_fops
= {
855 .owner
= THIS_MODULE
,
859 .unlocked_ioctl
= ppp_ioctl
,
861 .release
= ppp_release
864 static __net_init
int ppp_init_net(struct net
*net
)
869 pn
= kzalloc(sizeof(*pn
), GFP_KERNEL
);
873 idr_init(&pn
->units_idr
);
874 mutex_init(&pn
->all_ppp_mutex
);
876 INIT_LIST_HEAD(&pn
->all_channels
);
877 INIT_LIST_HEAD(&pn
->new_channels
);
879 spin_lock_init(&pn
->all_channels_lock
);
881 err
= net_assign_generic(net
, ppp_net_id
, pn
);
890 static __net_exit
void ppp_exit_net(struct net
*net
)
894 pn
= net_generic(net
, ppp_net_id
);
895 idr_destroy(&pn
->units_idr
);
897 * if someone has cached our net then
898 * further net_generic call will return NULL
900 net_assign_generic(net
, ppp_net_id
, NULL
);
904 static __net_initdata
struct pernet_operations ppp_net_ops
= {
905 .init
= ppp_init_net
,
906 .exit
= ppp_exit_net
,
909 #define PPP_MAJOR 108
911 /* Called at boot time if ppp is compiled into the kernel,
912 or at module load time (from init_module) if compiled as a module. */
913 static int __init
ppp_init(void)
917 printk(KERN_INFO
"PPP generic driver version " PPP_VERSION
"\n");
919 err
= register_pernet_gen_device(&ppp_net_id
, &ppp_net_ops
);
921 printk(KERN_ERR
"failed to register PPP pernet device (%d)\n", err
);
925 err
= register_chrdev(PPP_MAJOR
, "ppp", &ppp_device_fops
);
927 printk(KERN_ERR
"failed to register PPP device (%d)\n", err
);
931 ppp_class
= class_create(THIS_MODULE
, "ppp");
932 if (IS_ERR(ppp_class
)) {
933 err
= PTR_ERR(ppp_class
);
937 /* not a big deal if we fail here :-) */
938 device_create(ppp_class
, NULL
, MKDEV(PPP_MAJOR
, 0), NULL
, "ppp");
943 unregister_chrdev(PPP_MAJOR
, "ppp");
945 unregister_pernet_gen_device(ppp_net_id
, &ppp_net_ops
);
951 * Network interface unit routines.
954 ppp_start_xmit(struct sk_buff
*skb
, struct net_device
*dev
)
956 struct ppp
*ppp
= netdev_priv(dev
);
960 npi
= ethertype_to_npindex(ntohs(skb
->protocol
));
964 /* Drop, accept or reject the packet */
965 switch (ppp
->npmode
[npi
]) {
969 /* it would be nice to have a way to tell the network
970 system to queue this one up for later. */
977 /* Put the 2-byte PPP protocol number on the front,
978 making sure there is room for the address and control fields. */
979 if (skb_cow_head(skb
, PPP_HDRLEN
))
982 pp
= skb_push(skb
, 2);
983 proto
= npindex_to_proto
[npi
];
987 netif_stop_queue(dev
);
988 skb_queue_tail(&ppp
->file
.xq
, skb
);
989 ppp_xmit_process(ppp
);
994 ++ppp
->dev
->stats
.tx_dropped
;
999 ppp_net_ioctl(struct net_device
*dev
, struct ifreq
*ifr
, int cmd
)
1001 struct ppp
*ppp
= netdev_priv(dev
);
1003 void __user
*addr
= (void __user
*) ifr
->ifr_ifru
.ifru_data
;
1004 struct ppp_stats stats
;
1005 struct ppp_comp_stats cstats
;
1010 ppp_get_stats(ppp
, &stats
);
1011 if (copy_to_user(addr
, &stats
, sizeof(stats
)))
1016 case SIOCGPPPCSTATS
:
1017 memset(&cstats
, 0, sizeof(cstats
));
1019 ppp
->xcomp
->comp_stat(ppp
->xc_state
, &cstats
.c
);
1021 ppp
->rcomp
->decomp_stat(ppp
->rc_state
, &cstats
.d
);
1022 if (copy_to_user(addr
, &cstats
, sizeof(cstats
)))
1029 if (copy_to_user(addr
, vers
, strlen(vers
) + 1))
1041 static const struct net_device_ops ppp_netdev_ops
= {
1042 .ndo_start_xmit
= ppp_start_xmit
,
1043 .ndo_do_ioctl
= ppp_net_ioctl
,
1046 static void ppp_setup(struct net_device
*dev
)
1048 dev
->netdev_ops
= &ppp_netdev_ops
;
1049 dev
->hard_header_len
= PPP_HDRLEN
;
1052 dev
->tx_queue_len
= 3;
1053 dev
->type
= ARPHRD_PPP
;
1054 dev
->flags
= IFF_POINTOPOINT
| IFF_NOARP
| IFF_MULTICAST
;
1055 dev
->features
|= NETIF_F_NETNS_LOCAL
;
1059 * Transmit-side routines.
1063 * Called to do any work queued up on the transmit side
1064 * that can now be done.
1067 ppp_xmit_process(struct ppp
*ppp
)
1069 struct sk_buff
*skb
;
1072 if (!ppp
->closing
) {
1074 while (!ppp
->xmit_pending
1075 && (skb
= skb_dequeue(&ppp
->file
.xq
)))
1076 ppp_send_frame(ppp
, skb
);
1077 /* If there's no work left to do, tell the core net
1078 code that we can accept some more. */
1079 if (!ppp
->xmit_pending
&& !skb_peek(&ppp
->file
.xq
))
1080 netif_wake_queue(ppp
->dev
);
1082 ppp_xmit_unlock(ppp
);
1085 static inline struct sk_buff
*
1086 pad_compress_skb(struct ppp
*ppp
, struct sk_buff
*skb
)
1088 struct sk_buff
*new_skb
;
1090 int new_skb_size
= ppp
->dev
->mtu
+
1091 ppp
->xcomp
->comp_extra
+ ppp
->dev
->hard_header_len
;
1092 int compressor_skb_size
= ppp
->dev
->mtu
+
1093 ppp
->xcomp
->comp_extra
+ PPP_HDRLEN
;
1094 new_skb
= alloc_skb(new_skb_size
, GFP_ATOMIC
);
1096 if (net_ratelimit())
1097 printk(KERN_ERR
"PPP: no memory (comp pkt)\n");
1100 if (ppp
->dev
->hard_header_len
> PPP_HDRLEN
)
1101 skb_reserve(new_skb
,
1102 ppp
->dev
->hard_header_len
- PPP_HDRLEN
);
1104 /* compressor still expects A/C bytes in hdr */
1105 len
= ppp
->xcomp
->compress(ppp
->xc_state
, skb
->data
- 2,
1106 new_skb
->data
, skb
->len
+ 2,
1107 compressor_skb_size
);
1108 if (len
> 0 && (ppp
->flags
& SC_CCP_UP
)) {
1112 skb_pull(skb
, 2); /* pull off A/C bytes */
1113 } else if (len
== 0) {
1114 /* didn't compress, or CCP not up yet */
1120 * MPPE requires that we do not send unencrypted
1121 * frames. The compressor will return -1 if we
1122 * should drop the frame. We cannot simply test
1123 * the compress_proto because MPPE and MPPC share
1126 if (net_ratelimit())
1127 printk(KERN_ERR
"ppp: compressor dropped pkt\n");
1136 * Compress and send a frame.
1137 * The caller should have locked the xmit path,
1138 * and xmit_pending should be 0.
1141 ppp_send_frame(struct ppp
*ppp
, struct sk_buff
*skb
)
1143 int proto
= PPP_PROTO(skb
);
1144 struct sk_buff
*new_skb
;
1148 if (proto
< 0x8000) {
1149 #ifdef CONFIG_PPP_FILTER
1150 /* check if we should pass this packet */
1151 /* the filter instructions are constructed assuming
1152 a four-byte PPP header on each packet */
1153 *skb_push(skb
, 2) = 1;
1154 if (ppp
->pass_filter
1155 && sk_run_filter(skb
, ppp
->pass_filter
,
1156 ppp
->pass_len
) == 0) {
1158 printk(KERN_DEBUG
"PPP: outbound frame not passed\n");
1162 /* if this packet passes the active filter, record the time */
1163 if (!(ppp
->active_filter
1164 && sk_run_filter(skb
, ppp
->active_filter
,
1165 ppp
->active_len
) == 0))
1166 ppp
->last_xmit
= jiffies
;
1169 /* for data packets, record the time */
1170 ppp
->last_xmit
= jiffies
;
1171 #endif /* CONFIG_PPP_FILTER */
1174 ++ppp
->dev
->stats
.tx_packets
;
1175 ppp
->dev
->stats
.tx_bytes
+= skb
->len
- 2;
1179 if (!ppp
->vj
|| (ppp
->flags
& SC_COMP_TCP
) == 0)
1181 /* try to do VJ TCP header compression */
1182 new_skb
= alloc_skb(skb
->len
+ ppp
->dev
->hard_header_len
- 2,
1185 printk(KERN_ERR
"PPP: no memory (VJ comp pkt)\n");
1188 skb_reserve(new_skb
, ppp
->dev
->hard_header_len
- 2);
1190 len
= slhc_compress(ppp
->vj
, cp
, skb
->len
- 2,
1191 new_skb
->data
+ 2, &cp
,
1192 !(ppp
->flags
& SC_NO_TCP_CCID
));
1193 if (cp
== skb
->data
+ 2) {
1194 /* didn't compress */
1197 if (cp
[0] & SL_TYPE_COMPRESSED_TCP
) {
1198 proto
= PPP_VJC_COMP
;
1199 cp
[0] &= ~SL_TYPE_COMPRESSED_TCP
;
1201 proto
= PPP_VJC_UNCOMP
;
1202 cp
[0] = skb
->data
[2];
1206 cp
= skb_put(skb
, len
+ 2);
1213 /* peek at outbound CCP frames */
1214 ppp_ccp_peek(ppp
, skb
, 0);
1218 /* try to do packet compression */
1219 if ((ppp
->xstate
& SC_COMP_RUN
) && ppp
->xc_state
1220 && proto
!= PPP_LCP
&& proto
!= PPP_CCP
) {
1221 if (!(ppp
->flags
& SC_CCP_UP
) && (ppp
->flags
& SC_MUST_COMP
)) {
1222 if (net_ratelimit())
1223 printk(KERN_ERR
"ppp: compression required but down - pkt dropped.\n");
1226 skb
= pad_compress_skb(ppp
, skb
);
1232 * If we are waiting for traffic (demand dialling),
1233 * queue it up for pppd to receive.
1235 if (ppp
->flags
& SC_LOOP_TRAFFIC
) {
1236 if (ppp
->file
.rq
.qlen
> PPP_MAX_RQLEN
)
1238 skb_queue_tail(&ppp
->file
.rq
, skb
);
1239 wake_up_interruptible(&ppp
->file
.rwait
);
1243 ppp
->xmit_pending
= skb
;
1250 ++ppp
->dev
->stats
.tx_errors
;
1254 * Try to send the frame in xmit_pending.
1255 * The caller should have the xmit path locked.
1258 ppp_push(struct ppp
*ppp
)
1260 struct list_head
*list
;
1261 struct channel
*pch
;
1262 struct sk_buff
*skb
= ppp
->xmit_pending
;
1267 list
= &ppp
->channels
;
1268 if (list_empty(list
)) {
1269 /* nowhere to send the packet, just drop it */
1270 ppp
->xmit_pending
= NULL
;
1275 if ((ppp
->flags
& SC_MULTILINK
) == 0) {
1276 /* not doing multilink: send it down the first channel */
1278 pch
= list_entry(list
, struct channel
, clist
);
1280 spin_lock_bh(&pch
->downl
);
1282 if (pch
->chan
->ops
->start_xmit(pch
->chan
, skb
))
1283 ppp
->xmit_pending
= NULL
;
1285 /* channel got unregistered */
1287 ppp
->xmit_pending
= NULL
;
1289 spin_unlock_bh(&pch
->downl
);
1293 #ifdef CONFIG_PPP_MULTILINK
1294 /* Multilink: fragment the packet over as many links
1295 as can take the packet at the moment. */
1296 if (!ppp_mp_explode(ppp
, skb
))
1298 #endif /* CONFIG_PPP_MULTILINK */
1300 ppp
->xmit_pending
= NULL
;
1304 #ifdef CONFIG_PPP_MULTILINK
1306 * Divide a packet to be transmitted into fragments and
1307 * send them out the individual links.
1309 static int ppp_mp_explode(struct ppp
*ppp
, struct sk_buff
*skb
)
1312 int i
, bits
, hdrlen
, mtu
;
1316 unsigned char *p
, *q
;
1317 struct list_head
*list
;
1318 struct channel
*pch
;
1319 struct sk_buff
*frag
;
1320 struct ppp_channel
*chan
;
1322 nfree
= 0; /* # channels which have no packet already queued */
1323 navail
= 0; /* total # of usable channels (not deregistered) */
1324 hdrlen
= (ppp
->flags
& SC_MP_XSHORTSEQ
)? MPHDRLEN_SSN
: MPHDRLEN
;
1326 list_for_each_entry(pch
, &ppp
->channels
, clist
) {
1327 navail
+= pch
->avail
= (pch
->chan
!= NULL
);
1329 if (skb_queue_empty(&pch
->file
.xq
) ||
1334 if (!pch
->had_frag
&& i
< ppp
->nxchan
)
1341 * Don't start sending this packet unless at least half of
1342 * the channels are free. This gives much better TCP
1343 * performance if we have a lot of channels.
1345 if (nfree
== 0 || nfree
< navail
/ 2)
1346 return 0; /* can't take now, leave it in xmit_pending */
1348 /* Do protocol field compression (XXX this should be optional) */
1357 * Decide on fragment size.
1358 * We create a fragment for each free channel regardless of
1359 * how small they are (i.e. even 0 length) in order to minimize
1360 * the time that it will take to detect when a channel drops
1365 fragsize
= DIV_ROUND_UP(fragsize
, nfree
);
1366 /* nbigger channels get fragsize bytes, the rest get fragsize-1,
1367 except if nbigger==0, then they all get fragsize. */
1368 nbigger
= len
% nfree
;
1370 /* skip to the channel after the one we last used
1371 and start at that one */
1372 list
= &ppp
->channels
;
1373 for (i
= 0; i
< ppp
->nxchan
; ++i
) {
1375 if (list
== &ppp
->channels
) {
1381 /* create a fragment for each channel */
1383 while (nfree
> 0 || len
> 0) {
1385 if (list
== &ppp
->channels
) {
1389 pch
= list_entry(list
, struct channel
, clist
);
1395 * Skip this channel if it has a fragment pending already and
1396 * we haven't given a fragment to all of the free channels.
1398 if (pch
->avail
== 1) {
1406 /* check the channel's mtu and whether it is still attached. */
1407 spin_lock_bh(&pch
->downl
);
1408 if (pch
->chan
== NULL
) {
1409 /* can't use this channel, it's being deregistered */
1410 spin_unlock_bh(&pch
->downl
);
1418 * Create a fragment for this channel of
1419 * min(max(mtu+2-hdrlen, 4), fragsize, len) bytes.
1420 * If mtu+2-hdrlen < 4, that is a ridiculously small
1421 * MTU, so we use mtu = 2 + hdrlen.
1426 mtu
= pch
->chan
->mtu
+ 2 - hdrlen
;
1431 if (flen
== len
&& nfree
== 0)
1433 frag
= alloc_skb(flen
+ hdrlen
+ (flen
== 0), GFP_ATOMIC
);
1436 q
= skb_put(frag
, flen
+ hdrlen
);
1438 /* make the MP header */
1441 if (ppp
->flags
& SC_MP_XSHORTSEQ
) {
1442 q
[2] = bits
+ ((ppp
->nxseq
>> 8) & 0xf);
1446 q
[3] = ppp
->nxseq
>> 16;
1447 q
[4] = ppp
->nxseq
>> 8;
1453 * Unfortunately there is a bug in older versions of
1454 * the Linux PPP multilink reconstruction code where it
1455 * drops 0-length fragments. Therefore we make sure the
1456 * fragment has at least one byte of data. Any bytes
1457 * we add in this situation will end up as padding on the
1458 * end of the reconstructed packet.
1461 *skb_put(frag
, 1) = 0;
1463 memcpy(q
+ hdrlen
, p
, flen
);
1465 /* try to send it down the channel */
1467 if (!skb_queue_empty(&pch
->file
.xq
) ||
1468 !chan
->ops
->start_xmit(chan
, frag
))
1469 skb_queue_tail(&pch
->file
.xq
, frag
);
1475 spin_unlock_bh(&pch
->downl
);
1477 if (--nbigger
== 0 && fragsize
> 0)
1485 spin_unlock_bh(&pch
->downl
);
1487 printk(KERN_ERR
"PPP: no memory (fragment)\n");
1488 ++ppp
->dev
->stats
.tx_errors
;
1490 return 1; /* abandon the frame */
1492 #endif /* CONFIG_PPP_MULTILINK */
1495 * Try to send data out on a channel.
1498 ppp_channel_push(struct channel
*pch
)
1500 struct sk_buff
*skb
;
1503 spin_lock_bh(&pch
->downl
);
1505 while (!skb_queue_empty(&pch
->file
.xq
)) {
1506 skb
= skb_dequeue(&pch
->file
.xq
);
1507 if (!pch
->chan
->ops
->start_xmit(pch
->chan
, skb
)) {
1508 /* put the packet back and try again later */
1509 skb_queue_head(&pch
->file
.xq
, skb
);
1514 /* channel got deregistered */
1515 skb_queue_purge(&pch
->file
.xq
);
1517 spin_unlock_bh(&pch
->downl
);
1518 /* see if there is anything from the attached unit to be sent */
1519 if (skb_queue_empty(&pch
->file
.xq
)) {
1520 read_lock_bh(&pch
->upl
);
1523 ppp_xmit_process(ppp
);
1524 read_unlock_bh(&pch
->upl
);
1529 * Receive-side routines.
1532 /* misuse a few fields of the skb for MP reconstruction */
1533 #define sequence priority
1534 #define BEbits cb[0]
1537 ppp_do_recv(struct ppp
*ppp
, struct sk_buff
*skb
, struct channel
*pch
)
1541 ppp_receive_frame(ppp
, skb
, pch
);
1544 ppp_recv_unlock(ppp
);
1548 ppp_input(struct ppp_channel
*chan
, struct sk_buff
*skb
)
1550 struct channel
*pch
= chan
->ppp
;
1553 if (!pch
|| skb
->len
== 0) {
1558 proto
= PPP_PROTO(skb
);
1559 read_lock_bh(&pch
->upl
);
1560 if (!pch
->ppp
|| proto
>= 0xc000 || proto
== PPP_CCPFRAG
) {
1561 /* put it on the channel queue */
1562 skb_queue_tail(&pch
->file
.rq
, skb
);
1563 /* drop old frames if queue too long */
1564 while (pch
->file
.rq
.qlen
> PPP_MAX_RQLEN
1565 && (skb
= skb_dequeue(&pch
->file
.rq
)))
1567 wake_up_interruptible(&pch
->file
.rwait
);
1569 ppp_do_recv(pch
->ppp
, skb
, pch
);
1571 read_unlock_bh(&pch
->upl
);
1574 /* Put a 0-length skb in the receive queue as an error indication */
1576 ppp_input_error(struct ppp_channel
*chan
, int code
)
1578 struct channel
*pch
= chan
->ppp
;
1579 struct sk_buff
*skb
;
1584 read_lock_bh(&pch
->upl
);
1586 skb
= alloc_skb(0, GFP_ATOMIC
);
1588 skb
->len
= 0; /* probably unnecessary */
1590 ppp_do_recv(pch
->ppp
, skb
, pch
);
1593 read_unlock_bh(&pch
->upl
);
1597 * We come in here to process a received frame.
1598 * The receive side of the ppp unit is locked.
1601 ppp_receive_frame(struct ppp
*ppp
, struct sk_buff
*skb
, struct channel
*pch
)
1603 if (pskb_may_pull(skb
, 2)) {
1604 #ifdef CONFIG_PPP_MULTILINK
1605 /* XXX do channel-level decompression here */
1606 if (PPP_PROTO(skb
) == PPP_MP
)
1607 ppp_receive_mp_frame(ppp
, skb
, pch
);
1609 #endif /* CONFIG_PPP_MULTILINK */
1610 ppp_receive_nonmp_frame(ppp
, skb
);
1615 /* note: a 0-length skb is used as an error indication */
1616 ++ppp
->dev
->stats
.rx_length_errors
;
1619 ppp_receive_error(ppp
);
1623 ppp_receive_error(struct ppp
*ppp
)
1625 ++ppp
->dev
->stats
.rx_errors
;
1631 ppp_receive_nonmp_frame(struct ppp
*ppp
, struct sk_buff
*skb
)
1634 int proto
, len
, npi
;
1637 * Decompress the frame, if compressed.
1638 * Note that some decompressors need to see uncompressed frames
1639 * that come in as well as compressed frames.
1641 if (ppp
->rc_state
&& (ppp
->rstate
& SC_DECOMP_RUN
)
1642 && (ppp
->rstate
& (SC_DC_FERROR
| SC_DC_ERROR
)) == 0)
1643 skb
= ppp_decompress_frame(ppp
, skb
);
1645 if (ppp
->flags
& SC_MUST_COMP
&& ppp
->rstate
& SC_DC_FERROR
)
1648 proto
= PPP_PROTO(skb
);
1651 /* decompress VJ compressed packets */
1652 if (!ppp
->vj
|| (ppp
->flags
& SC_REJ_COMP_TCP
))
1655 if (skb_tailroom(skb
) < 124 || skb_cloned(skb
)) {
1656 /* copy to a new sk_buff with more tailroom */
1657 ns
= dev_alloc_skb(skb
->len
+ 128);
1659 printk(KERN_ERR
"PPP: no memory (VJ decomp)\n");
1663 skb_copy_bits(skb
, 0, skb_put(ns
, skb
->len
), skb
->len
);
1668 skb
->ip_summed
= CHECKSUM_NONE
;
1670 len
= slhc_uncompress(ppp
->vj
, skb
->data
+ 2, skb
->len
- 2);
1672 printk(KERN_DEBUG
"PPP: VJ decompression error\n");
1677 skb_put(skb
, len
- skb
->len
);
1678 else if (len
< skb
->len
)
1683 case PPP_VJC_UNCOMP
:
1684 if (!ppp
->vj
|| (ppp
->flags
& SC_REJ_COMP_TCP
))
1687 /* Until we fix the decompressor need to make sure
1688 * data portion is linear.
1690 if (!pskb_may_pull(skb
, skb
->len
))
1693 if (slhc_remember(ppp
->vj
, skb
->data
+ 2, skb
->len
- 2) <= 0) {
1694 printk(KERN_ERR
"PPP: VJ uncompressed error\n");
1701 ppp_ccp_peek(ppp
, skb
, 1);
1705 ++ppp
->dev
->stats
.rx_packets
;
1706 ppp
->dev
->stats
.rx_bytes
+= skb
->len
- 2;
1708 npi
= proto_to_npindex(proto
);
1710 /* control or unknown frame - pass it to pppd */
1711 skb_queue_tail(&ppp
->file
.rq
, skb
);
1712 /* limit queue length by dropping old frames */
1713 while (ppp
->file
.rq
.qlen
> PPP_MAX_RQLEN
1714 && (skb
= skb_dequeue(&ppp
->file
.rq
)))
1716 /* wake up any process polling or blocking on read */
1717 wake_up_interruptible(&ppp
->file
.rwait
);
1720 /* network protocol frame - give it to the kernel */
1722 #ifdef CONFIG_PPP_FILTER
1723 /* check if the packet passes the pass and active filters */
1724 /* the filter instructions are constructed assuming
1725 a four-byte PPP header on each packet */
1726 if (ppp
->pass_filter
|| ppp
->active_filter
) {
1727 if (skb_cloned(skb
) &&
1728 pskb_expand_head(skb
, 0, 0, GFP_ATOMIC
))
1731 *skb_push(skb
, 2) = 0;
1732 if (ppp
->pass_filter
1733 && sk_run_filter(skb
, ppp
->pass_filter
,
1734 ppp
->pass_len
) == 0) {
1736 printk(KERN_DEBUG
"PPP: inbound frame "
1741 if (!(ppp
->active_filter
1742 && sk_run_filter(skb
, ppp
->active_filter
,
1743 ppp
->active_len
) == 0))
1744 ppp
->last_recv
= jiffies
;
1747 #endif /* CONFIG_PPP_FILTER */
1748 ppp
->last_recv
= jiffies
;
1750 if ((ppp
->dev
->flags
& IFF_UP
) == 0
1751 || ppp
->npmode
[npi
] != NPMODE_PASS
) {
1754 /* chop off protocol */
1755 skb_pull_rcsum(skb
, 2);
1756 skb
->dev
= ppp
->dev
;
1757 skb
->protocol
= htons(npindex_to_ethertype
[npi
]);
1758 skb_reset_mac_header(skb
);
1766 ppp_receive_error(ppp
);
1769 static struct sk_buff
*
1770 ppp_decompress_frame(struct ppp
*ppp
, struct sk_buff
*skb
)
1772 int proto
= PPP_PROTO(skb
);
1776 /* Until we fix all the decompressor's need to make sure
1777 * data portion is linear.
1779 if (!pskb_may_pull(skb
, skb
->len
))
1782 if (proto
== PPP_COMP
) {
1785 switch(ppp
->rcomp
->compress_proto
) {
1787 obuff_size
= ppp
->mru
+ PPP_HDRLEN
+ 1;
1790 obuff_size
= ppp
->mru
+ PPP_HDRLEN
;
1794 ns
= dev_alloc_skb(obuff_size
);
1796 printk(KERN_ERR
"ppp_decompress_frame: no memory\n");
1799 /* the decompressor still expects the A/C bytes in the hdr */
1800 len
= ppp
->rcomp
->decompress(ppp
->rc_state
, skb
->data
- 2,
1801 skb
->len
+ 2, ns
->data
, obuff_size
);
1803 /* Pass the compressed frame to pppd as an
1804 error indication. */
1805 if (len
== DECOMP_FATALERROR
)
1806 ppp
->rstate
|= SC_DC_FERROR
;
1814 skb_pull(skb
, 2); /* pull off the A/C bytes */
1817 /* Uncompressed frame - pass to decompressor so it
1818 can update its dictionary if necessary. */
1819 if (ppp
->rcomp
->incomp
)
1820 ppp
->rcomp
->incomp(ppp
->rc_state
, skb
->data
- 2,
1827 ppp
->rstate
|= SC_DC_ERROR
;
1828 ppp_receive_error(ppp
);
1832 #ifdef CONFIG_PPP_MULTILINK
1834 * Receive a multilink frame.
1835 * We put it on the reconstruction queue and then pull off
1836 * as many completed frames as we can.
1839 ppp_receive_mp_frame(struct ppp
*ppp
, struct sk_buff
*skb
, struct channel
*pch
)
1843 int mphdrlen
= (ppp
->flags
& SC_MP_SHORTSEQ
)? MPHDRLEN_SSN
: MPHDRLEN
;
1845 if (!pskb_may_pull(skb
, mphdrlen
+ 1) || ppp
->mrru
== 0)
1846 goto err
; /* no good, throw it away */
1848 /* Decode sequence number and begin/end bits */
1849 if (ppp
->flags
& SC_MP_SHORTSEQ
) {
1850 seq
= ((skb
->data
[2] & 0x0f) << 8) | skb
->data
[3];
1853 seq
= (skb
->data
[3] << 16) | (skb
->data
[4] << 8)| skb
->data
[5];
1856 skb
->BEbits
= skb
->data
[2];
1857 skb_pull(skb
, mphdrlen
); /* pull off PPP and MP headers */
1860 * Do protocol ID decompression on the first fragment of each packet.
1862 if ((skb
->BEbits
& B
) && (skb
->data
[0] & 1))
1863 *skb_push(skb
, 1) = 0;
1866 * Expand sequence number to 32 bits, making it as close
1867 * as possible to ppp->minseq.
1869 seq
|= ppp
->minseq
& ~mask
;
1870 if ((int)(ppp
->minseq
- seq
) > (int)(mask
>> 1))
1872 else if ((int)(seq
- ppp
->minseq
) > (int)(mask
>> 1))
1873 seq
-= mask
+ 1; /* should never happen */
1874 skb
->sequence
= seq
;
1878 * If this packet comes before the next one we were expecting,
1881 if (seq_before(seq
, ppp
->nextseq
)) {
1883 ++ppp
->dev
->stats
.rx_dropped
;
1884 ppp_receive_error(ppp
);
1889 * Reevaluate minseq, the minimum over all channels of the
1890 * last sequence number received on each channel. Because of
1891 * the increasing sequence number rule, we know that any fragment
1892 * before `minseq' which hasn't arrived is never going to arrive.
1893 * The list of channels can't change because we have the receive
1894 * side of the ppp unit locked.
1896 list_for_each_entry(ch
, &ppp
->channels
, clist
) {
1897 if (seq_before(ch
->lastseq
, seq
))
1900 if (seq_before(ppp
->minseq
, seq
))
1903 /* Put the fragment on the reconstruction queue */
1904 ppp_mp_insert(ppp
, skb
);
1906 /* If the queue is getting long, don't wait any longer for packets
1907 before the start of the queue. */
1908 if (skb_queue_len(&ppp
->mrq
) >= PPP_MP_MAX_QLEN
) {
1909 struct sk_buff
*skb
= skb_peek(&ppp
->mrq
);
1910 if (seq_before(ppp
->minseq
, skb
->sequence
))
1911 ppp
->minseq
= skb
->sequence
;
1914 /* Pull completed packets off the queue and receive them. */
1915 while ((skb
= ppp_mp_reconstruct(ppp
)))
1916 ppp_receive_nonmp_frame(ppp
, skb
);
1922 ppp_receive_error(ppp
);
1926 * Insert a fragment on the MP reconstruction queue.
1927 * The queue is ordered by increasing sequence number.
1930 ppp_mp_insert(struct ppp
*ppp
, struct sk_buff
*skb
)
1933 struct sk_buff_head
*list
= &ppp
->mrq
;
1934 u32 seq
= skb
->sequence
;
1936 /* N.B. we don't need to lock the list lock because we have the
1937 ppp unit receive-side lock. */
1938 skb_queue_walk(list
, p
) {
1939 if (seq_before(seq
, p
->sequence
))
1942 __skb_queue_before(list
, p
, skb
);
1946 * Reconstruct a packet from the MP fragment queue.
1947 * We go through increasing sequence numbers until we find a
1948 * complete packet, or we get to the sequence number for a fragment
1949 * which hasn't arrived but might still do so.
1951 static struct sk_buff
*
1952 ppp_mp_reconstruct(struct ppp
*ppp
)
1954 u32 seq
= ppp
->nextseq
;
1955 u32 minseq
= ppp
->minseq
;
1956 struct sk_buff_head
*list
= &ppp
->mrq
;
1957 struct sk_buff
*p
, *next
;
1958 struct sk_buff
*head
, *tail
;
1959 struct sk_buff
*skb
= NULL
;
1960 int lost
= 0, len
= 0;
1962 if (ppp
->mrru
== 0) /* do nothing until mrru is set */
1966 for (p
= head
; p
!= (struct sk_buff
*) list
; p
= next
) {
1968 if (seq_before(p
->sequence
, seq
)) {
1969 /* this can't happen, anyway ignore the skb */
1970 printk(KERN_ERR
"ppp_mp_reconstruct bad seq %u < %u\n",
1975 if (p
->sequence
!= seq
) {
1976 /* Fragment `seq' is missing. If it is after
1977 minseq, it might arrive later, so stop here. */
1978 if (seq_after(seq
, minseq
))
1980 /* Fragment `seq' is lost, keep going. */
1982 seq
= seq_before(minseq
, p
->sequence
)?
1983 minseq
+ 1: p
->sequence
;
1989 * At this point we know that all the fragments from
1990 * ppp->nextseq to seq are either present or lost.
1991 * Also, there are no complete packets in the queue
1992 * that have no missing fragments and end before this
1996 /* B bit set indicates this fragment starts a packet */
1997 if (p
->BEbits
& B
) {
2005 /* Got a complete packet yet? */
2006 if (lost
== 0 && (p
->BEbits
& E
) && (head
->BEbits
& B
)) {
2007 if (len
> ppp
->mrru
+ 2) {
2008 ++ppp
->dev
->stats
.rx_length_errors
;
2009 printk(KERN_DEBUG
"PPP: reconstructed packet"
2010 " is too long (%d)\n", len
);
2011 } else if (p
== head
) {
2012 /* fragment is complete packet - reuse skb */
2016 } else if ((skb
= dev_alloc_skb(len
)) == NULL
) {
2017 ++ppp
->dev
->stats
.rx_missed_errors
;
2018 printk(KERN_DEBUG
"PPP: no memory for "
2019 "reconstructed packet");
2024 ppp
->nextseq
= seq
+ 1;
2028 * If this is the ending fragment of a packet,
2029 * and we haven't found a complete valid packet yet,
2030 * we can discard up to and including this fragment.
2038 /* If we have a complete packet, copy it all into one skb. */
2040 /* If we have discarded any fragments,
2041 signal a receive error. */
2042 if (head
->sequence
!= ppp
->nextseq
) {
2044 printk(KERN_DEBUG
" missed pkts %u..%u\n",
2045 ppp
->nextseq
, head
->sequence
-1);
2046 ++ppp
->dev
->stats
.rx_dropped
;
2047 ppp_receive_error(ppp
);
2051 /* copy to a single skb */
2052 for (p
= head
; p
!= tail
->next
; p
= p
->next
)
2053 skb_copy_bits(p
, 0, skb_put(skb
, p
->len
), p
->len
);
2054 ppp
->nextseq
= tail
->sequence
+ 1;
2058 /* Discard all the skbuffs that we have copied the data out of
2059 or that we can't use. */
2060 while ((p
= list
->next
) != head
) {
2061 __skb_unlink(p
, list
);
2067 #endif /* CONFIG_PPP_MULTILINK */
2070 * Channel interface.
2073 /* Create a new, unattached ppp channel. */
2074 int ppp_register_channel(struct ppp_channel
*chan
)
2076 return ppp_register_net_channel(current
->nsproxy
->net_ns
, chan
);
2079 /* Create a new, unattached ppp channel for specified net. */
2080 int ppp_register_net_channel(struct net
*net
, struct ppp_channel
*chan
)
2082 struct channel
*pch
;
2085 pch
= kzalloc(sizeof(struct channel
), GFP_KERNEL
);
2089 pn
= ppp_pernet(net
);
2093 pch
->chan_net
= net
;
2095 init_ppp_file(&pch
->file
, CHANNEL
);
2096 pch
->file
.hdrlen
= chan
->hdrlen
;
2097 #ifdef CONFIG_PPP_MULTILINK
2099 #endif /* CONFIG_PPP_MULTILINK */
2100 init_rwsem(&pch
->chan_sem
);
2101 spin_lock_init(&pch
->downl
);
2102 rwlock_init(&pch
->upl
);
2104 spin_lock_bh(&pn
->all_channels_lock
);
2105 pch
->file
.index
= ++pn
->last_channel_index
;
2106 list_add(&pch
->list
, &pn
->new_channels
);
2107 atomic_inc(&channel_count
);
2108 spin_unlock_bh(&pn
->all_channels_lock
);
2114 * Return the index of a channel.
2116 int ppp_channel_index(struct ppp_channel
*chan
)
2118 struct channel
*pch
= chan
->ppp
;
2121 return pch
->file
.index
;
2126 * Return the PPP unit number to which a channel is connected.
2128 int ppp_unit_number(struct ppp_channel
*chan
)
2130 struct channel
*pch
= chan
->ppp
;
2134 read_lock_bh(&pch
->upl
);
2136 unit
= pch
->ppp
->file
.index
;
2137 read_unlock_bh(&pch
->upl
);
2143 * Disconnect a channel from the generic layer.
2144 * This must be called in process context.
2147 ppp_unregister_channel(struct ppp_channel
*chan
)
2149 struct channel
*pch
= chan
->ppp
;
2153 return; /* should never happen */
2158 * This ensures that we have returned from any calls into the
2159 * the channel's start_xmit or ioctl routine before we proceed.
2161 down_write(&pch
->chan_sem
);
2162 spin_lock_bh(&pch
->downl
);
2164 spin_unlock_bh(&pch
->downl
);
2165 up_write(&pch
->chan_sem
);
2166 ppp_disconnect_channel(pch
);
2168 pn
= ppp_pernet(pch
->chan_net
);
2169 spin_lock_bh(&pn
->all_channels_lock
);
2170 list_del(&pch
->list
);
2171 spin_unlock_bh(&pn
->all_channels_lock
);
2174 wake_up_interruptible(&pch
->file
.rwait
);
2175 if (atomic_dec_and_test(&pch
->file
.refcnt
))
2176 ppp_destroy_channel(pch
);
2180 * Callback from a channel when it can accept more to transmit.
2181 * This should be called at BH/softirq level, not interrupt level.
2184 ppp_output_wakeup(struct ppp_channel
*chan
)
2186 struct channel
*pch
= chan
->ppp
;
2190 ppp_channel_push(pch
);
2194 * Compression control.
2197 /* Process the PPPIOCSCOMPRESS ioctl. */
2199 ppp_set_compress(struct ppp
*ppp
, unsigned long arg
)
2202 struct compressor
*cp
, *ocomp
;
2203 struct ppp_option_data data
;
2204 void *state
, *ostate
;
2205 unsigned char ccp_option
[CCP_MAX_OPTION_LENGTH
];
2208 if (copy_from_user(&data
, (void __user
*) arg
, sizeof(data
))
2209 || (data
.length
<= CCP_MAX_OPTION_LENGTH
2210 && copy_from_user(ccp_option
, (void __user
*) data
.ptr
, data
.length
)))
2213 if (data
.length
> CCP_MAX_OPTION_LENGTH
2214 || ccp_option
[1] < 2 || ccp_option
[1] > data
.length
)
2217 cp
= try_then_request_module(
2218 find_compressor(ccp_option
[0]),
2219 "ppp-compress-%d", ccp_option
[0]);
2224 if (data
.transmit
) {
2225 state
= cp
->comp_alloc(ccp_option
, data
.length
);
2228 ppp
->xstate
&= ~SC_COMP_RUN
;
2230 ostate
= ppp
->xc_state
;
2232 ppp
->xc_state
= state
;
2233 ppp_xmit_unlock(ppp
);
2235 ocomp
->comp_free(ostate
);
2236 module_put(ocomp
->owner
);
2240 module_put(cp
->owner
);
2243 state
= cp
->decomp_alloc(ccp_option
, data
.length
);
2246 ppp
->rstate
&= ~SC_DECOMP_RUN
;
2248 ostate
= ppp
->rc_state
;
2250 ppp
->rc_state
= state
;
2251 ppp_recv_unlock(ppp
);
2253 ocomp
->decomp_free(ostate
);
2254 module_put(ocomp
->owner
);
2258 module_put(cp
->owner
);
2266 * Look at a CCP packet and update our state accordingly.
2267 * We assume the caller has the xmit or recv path locked.
2270 ppp_ccp_peek(struct ppp
*ppp
, struct sk_buff
*skb
, int inbound
)
2275 if (!pskb_may_pull(skb
, CCP_HDRLEN
+ 2))
2276 return; /* no header */
2279 switch (CCP_CODE(dp
)) {
2282 /* A ConfReq starts negotiation of compression
2283 * in one direction of transmission,
2284 * and hence brings it down...but which way?
2287 * A ConfReq indicates what the sender would like to receive
2290 /* He is proposing what I should send */
2291 ppp
->xstate
&= ~SC_COMP_RUN
;
2293 /* I am proposing to what he should send */
2294 ppp
->rstate
&= ~SC_DECOMP_RUN
;
2301 * CCP is going down, both directions of transmission
2303 ppp
->rstate
&= ~SC_DECOMP_RUN
;
2304 ppp
->xstate
&= ~SC_COMP_RUN
;
2308 if ((ppp
->flags
& (SC_CCP_OPEN
| SC_CCP_UP
)) != SC_CCP_OPEN
)
2310 len
= CCP_LENGTH(dp
);
2311 if (!pskb_may_pull(skb
, len
+ 2))
2312 return; /* too short */
2315 if (len
< CCP_OPT_MINLEN
|| len
< CCP_OPT_LENGTH(dp
))
2318 /* we will start receiving compressed packets */
2321 if (ppp
->rcomp
->decomp_init(ppp
->rc_state
, dp
, len
,
2322 ppp
->file
.index
, 0, ppp
->mru
, ppp
->debug
)) {
2323 ppp
->rstate
|= SC_DECOMP_RUN
;
2324 ppp
->rstate
&= ~(SC_DC_ERROR
| SC_DC_FERROR
);
2327 /* we will soon start sending compressed packets */
2330 if (ppp
->xcomp
->comp_init(ppp
->xc_state
, dp
, len
,
2331 ppp
->file
.index
, 0, ppp
->debug
))
2332 ppp
->xstate
|= SC_COMP_RUN
;
2337 /* reset the [de]compressor */
2338 if ((ppp
->flags
& SC_CCP_UP
) == 0)
2341 if (ppp
->rc_state
&& (ppp
->rstate
& SC_DECOMP_RUN
)) {
2342 ppp
->rcomp
->decomp_reset(ppp
->rc_state
);
2343 ppp
->rstate
&= ~SC_DC_ERROR
;
2346 if (ppp
->xc_state
&& (ppp
->xstate
& SC_COMP_RUN
))
2347 ppp
->xcomp
->comp_reset(ppp
->xc_state
);
2353 /* Free up compression resources. */
2355 ppp_ccp_closed(struct ppp
*ppp
)
2357 void *xstate
, *rstate
;
2358 struct compressor
*xcomp
, *rcomp
;
2361 ppp
->flags
&= ~(SC_CCP_OPEN
| SC_CCP_UP
);
2364 xstate
= ppp
->xc_state
;
2365 ppp
->xc_state
= NULL
;
2368 rstate
= ppp
->rc_state
;
2369 ppp
->rc_state
= NULL
;
2373 xcomp
->comp_free(xstate
);
2374 module_put(xcomp
->owner
);
2377 rcomp
->decomp_free(rstate
);
2378 module_put(rcomp
->owner
);
2382 /* List of compressors. */
2383 static LIST_HEAD(compressor_list
);
2384 static DEFINE_SPINLOCK(compressor_list_lock
);
2386 struct compressor_entry
{
2387 struct list_head list
;
2388 struct compressor
*comp
;
2391 static struct compressor_entry
*
2392 find_comp_entry(int proto
)
2394 struct compressor_entry
*ce
;
2396 list_for_each_entry(ce
, &compressor_list
, list
) {
2397 if (ce
->comp
->compress_proto
== proto
)
2403 /* Register a compressor */
2405 ppp_register_compressor(struct compressor
*cp
)
2407 struct compressor_entry
*ce
;
2409 spin_lock(&compressor_list_lock
);
2411 if (find_comp_entry(cp
->compress_proto
))
2414 ce
= kmalloc(sizeof(struct compressor_entry
), GFP_ATOMIC
);
2419 list_add(&ce
->list
, &compressor_list
);
2421 spin_unlock(&compressor_list_lock
);
2425 /* Unregister a compressor */
2427 ppp_unregister_compressor(struct compressor
*cp
)
2429 struct compressor_entry
*ce
;
2431 spin_lock(&compressor_list_lock
);
2432 ce
= find_comp_entry(cp
->compress_proto
);
2433 if (ce
&& ce
->comp
== cp
) {
2434 list_del(&ce
->list
);
2437 spin_unlock(&compressor_list_lock
);
2440 /* Find a compressor. */
2441 static struct compressor
*
2442 find_compressor(int type
)
2444 struct compressor_entry
*ce
;
2445 struct compressor
*cp
= NULL
;
2447 spin_lock(&compressor_list_lock
);
2448 ce
= find_comp_entry(type
);
2451 if (!try_module_get(cp
->owner
))
2454 spin_unlock(&compressor_list_lock
);
2459 * Miscelleneous stuff.
2463 ppp_get_stats(struct ppp
*ppp
, struct ppp_stats
*st
)
2465 struct slcompress
*vj
= ppp
->vj
;
2467 memset(st
, 0, sizeof(*st
));
2468 st
->p
.ppp_ipackets
= ppp
->dev
->stats
.rx_packets
;
2469 st
->p
.ppp_ierrors
= ppp
->dev
->stats
.rx_errors
;
2470 st
->p
.ppp_ibytes
= ppp
->dev
->stats
.rx_bytes
;
2471 st
->p
.ppp_opackets
= ppp
->dev
->stats
.tx_packets
;
2472 st
->p
.ppp_oerrors
= ppp
->dev
->stats
.tx_errors
;
2473 st
->p
.ppp_obytes
= ppp
->dev
->stats
.tx_bytes
;
2476 st
->vj
.vjs_packets
= vj
->sls_o_compressed
+ vj
->sls_o_uncompressed
;
2477 st
->vj
.vjs_compressed
= vj
->sls_o_compressed
;
2478 st
->vj
.vjs_searches
= vj
->sls_o_searches
;
2479 st
->vj
.vjs_misses
= vj
->sls_o_misses
;
2480 st
->vj
.vjs_errorin
= vj
->sls_i_error
;
2481 st
->vj
.vjs_tossed
= vj
->sls_i_tossed
;
2482 st
->vj
.vjs_uncompressedin
= vj
->sls_i_uncompressed
;
2483 st
->vj
.vjs_compressedin
= vj
->sls_i_compressed
;
2487 * Stuff for handling the lists of ppp units and channels
2488 * and for initialization.
2492 * Create a new ppp interface unit. Fails if it can't allocate memory
2493 * or if there is already a unit with the requested number.
2494 * unit == -1 means allocate a new number.
2497 ppp_create_interface(struct net
*net
, int unit
, int *retp
)
2501 struct net_device
*dev
= NULL
;
2505 dev
= alloc_netdev(sizeof(struct ppp
), "", ppp_setup
);
2509 pn
= ppp_pernet(net
);
2511 ppp
= netdev_priv(dev
);
2514 init_ppp_file(&ppp
->file
, INTERFACE
);
2515 ppp
->file
.hdrlen
= PPP_HDRLEN
- 2; /* don't count proto bytes */
2516 for (i
= 0; i
< NUM_NP
; ++i
)
2517 ppp
->npmode
[i
] = NPMODE_PASS
;
2518 INIT_LIST_HEAD(&ppp
->channels
);
2519 spin_lock_init(&ppp
->rlock
);
2520 spin_lock_init(&ppp
->wlock
);
2521 #ifdef CONFIG_PPP_MULTILINK
2523 skb_queue_head_init(&ppp
->mrq
);
2524 #endif /* CONFIG_PPP_MULTILINK */
2527 * drum roll: don't forget to set
2528 * the net device is belong to
2530 dev_net_set(dev
, net
);
2533 mutex_lock(&pn
->all_ppp_mutex
);
2536 unit
= unit_get(&pn
->units_idr
, ppp
);
2542 if (unit_find(&pn
->units_idr
, unit
))
2543 goto out2
; /* unit already exists */
2545 * if caller need a specified unit number
2546 * lets try to satisfy him, otherwise --
2547 * he should better ask us for new unit number
2549 * NOTE: yes I know that returning EEXIST it's not
2550 * fair but at least pppd will ask us to allocate
2551 * new unit in this case so user is happy :)
2553 unit
= unit_set(&pn
->units_idr
, ppp
, unit
);
2558 /* Initialize the new ppp unit */
2559 ppp
->file
.index
= unit
;
2560 sprintf(dev
->name
, "ppp%d", unit
);
2562 ret
= register_netdev(dev
);
2564 unit_put(&pn
->units_idr
, unit
);
2565 printk(KERN_ERR
"PPP: couldn't register device %s (%d)\n",
2572 atomic_inc(&ppp_unit_count
);
2573 mutex_unlock(&pn
->all_ppp_mutex
);
2579 mutex_unlock(&pn
->all_ppp_mutex
);
2587 * Initialize a ppp_file structure.
2590 init_ppp_file(struct ppp_file
*pf
, int kind
)
2593 skb_queue_head_init(&pf
->xq
);
2594 skb_queue_head_init(&pf
->rq
);
2595 atomic_set(&pf
->refcnt
, 1);
2596 init_waitqueue_head(&pf
->rwait
);
2600 * Take down a ppp interface unit - called when the owning file
2601 * (the one that created the unit) is closed or detached.
2603 static void ppp_shutdown_interface(struct ppp
*ppp
)
2607 pn
= ppp_pernet(ppp
->ppp_net
);
2608 mutex_lock(&pn
->all_ppp_mutex
);
2610 /* This will call dev_close() for us. */
2612 if (!ppp
->closing
) {
2615 unregister_netdev(ppp
->dev
);
2619 unit_put(&pn
->units_idr
, ppp
->file
.index
);
2622 wake_up_interruptible(&ppp
->file
.rwait
);
2624 mutex_unlock(&pn
->all_ppp_mutex
);
2628 * Free the memory used by a ppp unit. This is only called once
2629 * there are no channels connected to the unit and no file structs
2630 * that reference the unit.
2632 static void ppp_destroy_interface(struct ppp
*ppp
)
2634 atomic_dec(&ppp_unit_count
);
2636 if (!ppp
->file
.dead
|| ppp
->n_channels
) {
2637 /* "can't happen" */
2638 printk(KERN_ERR
"ppp: destroying ppp struct %p but dead=%d "
2639 "n_channels=%d !\n", ppp
, ppp
->file
.dead
,
2644 ppp_ccp_closed(ppp
);
2649 skb_queue_purge(&ppp
->file
.xq
);
2650 skb_queue_purge(&ppp
->file
.rq
);
2651 #ifdef CONFIG_PPP_MULTILINK
2652 skb_queue_purge(&ppp
->mrq
);
2653 #endif /* CONFIG_PPP_MULTILINK */
2654 #ifdef CONFIG_PPP_FILTER
2655 kfree(ppp
->pass_filter
);
2656 ppp
->pass_filter
= NULL
;
2657 kfree(ppp
->active_filter
);
2658 ppp
->active_filter
= NULL
;
2659 #endif /* CONFIG_PPP_FILTER */
2661 if (ppp
->xmit_pending
)
2662 kfree_skb(ppp
->xmit_pending
);
2664 free_netdev(ppp
->dev
);
2668 * Locate an existing ppp unit.
2669 * The caller should have locked the all_ppp_mutex.
2672 ppp_find_unit(struct ppp_net
*pn
, int unit
)
2674 return unit_find(&pn
->units_idr
, unit
);
2678 * Locate an existing ppp channel.
2679 * The caller should have locked the all_channels_lock.
2680 * First we look in the new_channels list, then in the
2681 * all_channels list. If found in the new_channels list,
2682 * we move it to the all_channels list. This is for speed
2683 * when we have a lot of channels in use.
2685 static struct channel
*
2686 ppp_find_channel(struct ppp_net
*pn
, int unit
)
2688 struct channel
*pch
;
2690 list_for_each_entry(pch
, &pn
->new_channels
, list
) {
2691 if (pch
->file
.index
== unit
) {
2692 list_move(&pch
->list
, &pn
->all_channels
);
2697 list_for_each_entry(pch
, &pn
->all_channels
, list
) {
2698 if (pch
->file
.index
== unit
)
2706 * Connect a PPP channel to a PPP interface unit.
2709 ppp_connect_channel(struct channel
*pch
, int unit
)
2716 pn
= ppp_pernet(pch
->chan_net
);
2718 mutex_lock(&pn
->all_ppp_mutex
);
2719 ppp
= ppp_find_unit(pn
, unit
);
2722 write_lock_bh(&pch
->upl
);
2728 if (pch
->file
.hdrlen
> ppp
->file
.hdrlen
)
2729 ppp
->file
.hdrlen
= pch
->file
.hdrlen
;
2730 hdrlen
= pch
->file
.hdrlen
+ 2; /* for protocol bytes */
2731 if (hdrlen
> ppp
->dev
->hard_header_len
)
2732 ppp
->dev
->hard_header_len
= hdrlen
;
2733 list_add_tail(&pch
->clist
, &ppp
->channels
);
2736 atomic_inc(&ppp
->file
.refcnt
);
2741 write_unlock_bh(&pch
->upl
);
2743 mutex_unlock(&pn
->all_ppp_mutex
);
2748 * Disconnect a channel from its ppp unit.
2751 ppp_disconnect_channel(struct channel
*pch
)
2756 write_lock_bh(&pch
->upl
);
2759 write_unlock_bh(&pch
->upl
);
2761 /* remove it from the ppp unit's list */
2763 list_del(&pch
->clist
);
2764 if (--ppp
->n_channels
== 0)
2765 wake_up_interruptible(&ppp
->file
.rwait
);
2767 if (atomic_dec_and_test(&ppp
->file
.refcnt
))
2768 ppp_destroy_interface(ppp
);
2775 * Free up the resources used by a ppp channel.
2777 static void ppp_destroy_channel(struct channel
*pch
)
2779 atomic_dec(&channel_count
);
2781 if (!pch
->file
.dead
) {
2782 /* "can't happen" */
2783 printk(KERN_ERR
"ppp: destroying undead channel %p !\n",
2787 skb_queue_purge(&pch
->file
.xq
);
2788 skb_queue_purge(&pch
->file
.rq
);
2792 static void __exit
ppp_cleanup(void)
2794 /* should never happen */
2795 if (atomic_read(&ppp_unit_count
) || atomic_read(&channel_count
))
2796 printk(KERN_ERR
"PPP: removing module but units remain!\n");
2797 unregister_chrdev(PPP_MAJOR
, "ppp");
2798 device_destroy(ppp_class
, MKDEV(PPP_MAJOR
, 0));
2799 class_destroy(ppp_class
);
2800 unregister_pernet_gen_device(ppp_net_id
, &ppp_net_ops
);
2804 * Units handling. Caller must protect concurrent access
2805 * by holding all_ppp_mutex
2808 /* associate pointer with specified number */
2809 static int unit_set(struct idr
*p
, void *ptr
, int n
)
2814 if (!idr_pre_get(p
, GFP_KERNEL
)) {
2815 printk(KERN_ERR
"PPP: No free memory for idr\n");
2819 err
= idr_get_new_above(p
, ptr
, n
, &unit
);
2824 idr_remove(p
, unit
);
2831 /* get new free unit number and associate pointer with it */
2832 static int unit_get(struct idr
*p
, void *ptr
)
2837 if (!idr_pre_get(p
, GFP_KERNEL
)) {
2838 printk(KERN_ERR
"PPP: No free memory for idr\n");
2842 err
= idr_get_new_above(p
, ptr
, 0, &unit
);
2849 /* put unit number back to a pool */
2850 static void unit_put(struct idr
*p
, int n
)
2855 /* get pointer associated with the number */
2856 static void *unit_find(struct idr
*p
, int n
)
2858 return idr_find(p
, n
);
2861 /* Module/initialization stuff */
2863 module_init(ppp_init
);
2864 module_exit(ppp_cleanup
);
2866 EXPORT_SYMBOL(ppp_register_net_channel
);
2867 EXPORT_SYMBOL(ppp_register_channel
);
2868 EXPORT_SYMBOL(ppp_unregister_channel
);
2869 EXPORT_SYMBOL(ppp_channel_index
);
2870 EXPORT_SYMBOL(ppp_unit_number
);
2871 EXPORT_SYMBOL(ppp_input
);
2872 EXPORT_SYMBOL(ppp_input_error
);
2873 EXPORT_SYMBOL(ppp_output_wakeup
);
2874 EXPORT_SYMBOL(ppp_register_compressor
);
2875 EXPORT_SYMBOL(ppp_unregister_compressor
);
2876 MODULE_LICENSE("GPL");
2877 MODULE_ALIAS_CHARDEV_MAJOR(PPP_MAJOR
);
2878 MODULE_ALIAS("/dev/ppp");