2 * X.25 Packet Layer release 002
4 * This is ALPHA test software. This code may break your machine,
5 * randomly fail to work with new releases, misbehave and/or generally
6 * screw up. It might even work.
8 * This code REQUIRES 2.1.15 or higher
11 * This module is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation; either version
14 * 2 of the License, or (at your option) any later version.
17 * X.25 001 Jonathan Naylor Started coding.
18 * X.25 002 Jonathan Naylor Centralised disconnection code.
19 * New timer architecture.
20 * 2000-03-20 Daniela Squassoni Disabling/enabling of facilities
22 * 2000-11-10 Henner Eisen Check and reset for out-of-sequence
26 #include <linux/errno.h>
27 #include <linux/types.h>
28 #include <linux/socket.h>
30 #include <linux/kernel.h>
31 #include <linux/sched.h>
32 #include <linux/timer.h>
33 #include <linux/string.h>
34 #include <linux/sockios.h>
35 #include <linux/net.h>
36 #include <linux/inet.h>
37 #include <linux/netdevice.h>
38 #include <linux/skbuff.h>
40 #include <net/ip.h> /* For ip_rcv */
42 #include <asm/system.h>
43 #include <linux/fcntl.h>
45 #include <linux/interrupt.h>
48 static int x25_queue_rx_frame(struct sock
*sk
, struct sk_buff
*skb
, int more
)
50 struct sk_buff
*skbo
, *skbn
= skb
;
51 struct x25_opt
*x25
= x25_sk(sk
);
54 x25
->fraglen
+= skb
->len
;
55 skb_queue_tail(&x25
->fragment_queue
, skb
);
56 skb_set_owner_r(skb
, sk
);
60 if (!more
&& x25
->fraglen
> 0) { /* End of fragment */
61 int len
= x25
->fraglen
+ skb
->len
;
63 if ((skbn
= alloc_skb(len
, GFP_ATOMIC
)) == NULL
){
68 skb_queue_tail(&x25
->fragment_queue
, skb
);
70 skbn
->h
.raw
= skbn
->data
;
72 skbo
= skb_dequeue(&x25
->fragment_queue
);
73 memcpy(skb_put(skbn
, skbo
->len
), skbo
->data
, skbo
->len
);
77 skb_dequeue(&x25
->fragment_queue
)) != NULL
) {
78 skb_pull(skbo
, (x25
->neighbour
->extended
) ?
79 X25_EXT_MIN_LEN
: X25_STD_MIN_LEN
);
80 memcpy(skb_put(skbn
, skbo
->len
), skbo
->data
, skbo
->len
);
87 skb_set_owner_r(skbn
, sk
);
88 skb_queue_tail(&sk
->sk_receive_queue
, skbn
);
89 if (!sock_flag(sk
, SOCK_DEAD
))
90 sk
->sk_data_ready(sk
, skbn
->len
);
96 * State machine for state 1, Awaiting Call Accepted State.
97 * The handling of the timer(s) is in file x25_timer.c.
98 * Handling of state 0 and connection release is in af_x25.c.
100 static int x25_state1_machine(struct sock
*sk
, struct sk_buff
*skb
, int frametype
)
102 struct x25_address source_addr
, dest_addr
;
105 case X25_CALL_ACCEPTED
: {
106 struct x25_opt
*x25
= x25_sk(sk
);
109 x25
->condition
= 0x00;
114 x25
->state
= X25_STATE_3
;
115 sk
->sk_state
= TCP_ESTABLISHED
;
117 * Parse the data in the frame.
119 skb_pull(skb
, X25_STD_MIN_LEN
);
120 skb_pull(skb
, x25_addr_ntoa(skb
->data
, &source_addr
, &dest_addr
));
122 x25_parse_facilities(skb
, &x25
->facilities
,
123 &x25
->vc_facil_mask
));
125 * Copy any Call User Data.
128 memcpy(x25
->calluserdata
.cuddata
, skb
->data
,
130 x25
->calluserdata
.cudlength
= skb
->len
;
132 if (!sock_flag(sk
, SOCK_DEAD
))
133 sk
->sk_state_change(sk
);
136 case X25_CLEAR_REQUEST
:
137 x25_write_internal(sk
, X25_CLEAR_CONFIRMATION
);
138 x25_disconnect(sk
, ECONNREFUSED
, skb
->data
[3], skb
->data
[4]);
149 * State machine for state 2, Awaiting Clear Confirmation State.
150 * The handling of the timer(s) is in file x25_timer.c
151 * Handling of state 0 and connection release is in af_x25.c.
153 static int x25_state2_machine(struct sock
*sk
, struct sk_buff
*skb
, int frametype
)
157 case X25_CLEAR_REQUEST
:
158 x25_write_internal(sk
, X25_CLEAR_CONFIRMATION
);
159 x25_disconnect(sk
, 0, skb
->data
[3], skb
->data
[4]);
162 case X25_CLEAR_CONFIRMATION
:
163 x25_disconnect(sk
, 0, 0, 0);
174 * State machine for state 3, Connected State.
175 * The handling of the timer(s) is in file x25_timer.c
176 * Handling of state 0 and connection release is in af_x25.c.
178 static int x25_state3_machine(struct sock
*sk
, struct sk_buff
*skb
, int frametype
, int ns
, int nr
, int q
, int d
, int m
)
182 struct x25_opt
*x25
= x25_sk(sk
);
184 modulus
= (x25
->neighbour
->extended
) ? X25_EMODULUS
: X25_SMODULUS
;
188 case X25_RESET_REQUEST
:
189 x25_write_internal(sk
, X25_RESET_CONFIRMATION
);
191 x25
->condition
= 0x00;
196 x25_requeue_frames(sk
);
199 case X25_CLEAR_REQUEST
:
200 x25_write_internal(sk
, X25_CLEAR_CONFIRMATION
);
201 x25_disconnect(sk
, 0, skb
->data
[3], skb
->data
[4]);
206 if (!x25_validate_nr(sk
, nr
)) {
207 x25_clear_queues(sk
);
208 x25_write_internal(sk
, X25_RESET_REQUEST
);
209 x25_start_t22timer(sk
);
210 x25
->condition
= 0x00;
215 x25
->state
= X25_STATE_4
;
217 x25_frames_acked(sk
, nr
);
218 if (frametype
== X25_RNR
) {
219 x25
->condition
|= X25_COND_PEER_RX_BUSY
;
221 x25
->condition
&= ~X25_COND_PEER_RX_BUSY
;
226 case X25_DATA
: /* XXX */
227 x25
->condition
&= ~X25_COND_PEER_RX_BUSY
;
228 if ((ns
!= x25
->vr
) || !x25_validate_nr(sk
, nr
)) {
229 x25_clear_queues(sk
);
230 x25_write_internal(sk
, X25_RESET_REQUEST
);
231 x25_start_t22timer(sk
);
232 x25
->condition
= 0x00;
237 x25
->state
= X25_STATE_4
;
240 x25_frames_acked(sk
, nr
);
242 if (x25_queue_rx_frame(sk
, skb
, m
) == 0) {
243 x25
->vr
= (x25
->vr
+ 1) % modulus
;
246 /* Should never happen */
247 x25_clear_queues(sk
);
248 x25_write_internal(sk
, X25_RESET_REQUEST
);
249 x25_start_t22timer(sk
);
250 x25
->condition
= 0x00;
255 x25
->state
= X25_STATE_4
;
258 if (atomic_read(&sk
->sk_rmem_alloc
) >
260 x25
->condition
|= X25_COND_OWN_RX_BUSY
;
263 * If the window is full Ack it immediately, else
264 * start the holdback timer.
266 if (((x25
->vl
+ x25
->facilities
.winsize_in
) % modulus
) == x25
->vr
) {
267 x25
->condition
&= ~X25_COND_ACK_PENDING
;
269 x25_enquiry_response(sk
);
271 x25
->condition
|= X25_COND_ACK_PENDING
;
272 x25_start_t2timer(sk
);
276 case X25_INTERRUPT_CONFIRMATION
:
281 if (sock_flag(sk
, SOCK_URGINLINE
))
282 queued
= !sock_queue_rcv_skb(sk
, skb
);
284 skb_set_owner_r(skb
, sk
);
285 skb_queue_tail(&x25
->interrupt_in_queue
, skb
);
289 x25_write_internal(sk
, X25_INTERRUPT_CONFIRMATION
);
293 printk(KERN_WARNING
"x25: unknown %02X in state 3\n", frametype
);
301 * State machine for state 4, Awaiting Reset Confirmation State.
302 * The handling of the timer(s) is in file x25_timer.c
303 * Handling of state 0 and connection release is in af_x25.c.
305 static int x25_state4_machine(struct sock
*sk
, struct sk_buff
*skb
, int frametype
)
309 case X25_RESET_REQUEST
:
310 x25_write_internal(sk
, X25_RESET_CONFIRMATION
);
311 case X25_RESET_CONFIRMATION
: {
312 struct x25_opt
*x25
= x25_sk(sk
);
315 x25
->condition
= 0x00;
320 x25
->state
= X25_STATE_3
;
321 x25_requeue_frames(sk
);
324 case X25_CLEAR_REQUEST
:
325 x25_write_internal(sk
, X25_CLEAR_CONFIRMATION
);
326 x25_disconnect(sk
, 0, skb
->data
[3], skb
->data
[4]);
336 /* Higher level upcall for a LAPB frame */
337 int x25_process_rx_frame(struct sock
*sk
, struct sk_buff
*skb
)
339 struct x25_opt
*x25
= x25_sk(sk
);
340 int queued
= 0, frametype
, ns
, nr
, q
, d
, m
;
342 if (x25
->state
== X25_STATE_0
)
345 frametype
= x25_decode(sk
, skb
, &ns
, &nr
, &q
, &d
, &m
);
347 switch (x25
->state
) {
349 queued
= x25_state1_machine(sk
, skb
, frametype
);
352 queued
= x25_state2_machine(sk
, skb
, frametype
);
355 queued
= x25_state3_machine(sk
, skb
, frametype
, ns
, nr
, q
, d
, m
);
358 queued
= x25_state4_machine(sk
, skb
, frametype
);
367 int x25_backlog_rcv(struct sock
*sk
, struct sk_buff
*skb
)
369 int queued
= x25_process_rx_frame(sk
, skb
);