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/kernel.h>
28 #include <linux/string.h>
29 #include <linux/skbuff.h>
31 #include <net/tcp_states.h>
34 static int x25_queue_rx_frame(struct sock
*sk
, struct sk_buff
*skb
, int more
)
36 struct sk_buff
*skbo
, *skbn
= skb
;
37 struct x25_sock
*x25
= x25_sk(sk
);
40 x25
->fraglen
+= skb
->len
;
41 skb_queue_tail(&x25
->fragment_queue
, skb
);
42 skb_set_owner_r(skb
, sk
);
46 if (!more
&& x25
->fraglen
> 0) { /* End of fragment */
47 int len
= x25
->fraglen
+ skb
->len
;
49 if ((skbn
= alloc_skb(len
, GFP_ATOMIC
)) == NULL
){
54 skb_queue_tail(&x25
->fragment_queue
, skb
);
56 skb_reset_transport_header(skbn
);
58 skbo
= skb_dequeue(&x25
->fragment_queue
);
59 memcpy(skb_put(skbn
, skbo
->len
), skbo
->data
, skbo
->len
);
63 skb_dequeue(&x25
->fragment_queue
)) != NULL
) {
64 skb_pull(skbo
, (x25
->neighbour
->extended
) ?
65 X25_EXT_MIN_LEN
: X25_STD_MIN_LEN
);
66 memcpy(skb_put(skbn
, skbo
->len
), skbo
->data
, skbo
->len
);
73 skb_set_owner_r(skbn
, sk
);
74 skb_queue_tail(&sk
->sk_receive_queue
, skbn
);
75 if (!sock_flag(sk
, SOCK_DEAD
))
76 sk
->sk_data_ready(sk
, skbn
->len
);
82 * State machine for state 1, Awaiting Call Accepted State.
83 * The handling of the timer(s) is in file x25_timer.c.
84 * Handling of state 0 and connection release is in af_x25.c.
86 static int x25_state1_machine(struct sock
*sk
, struct sk_buff
*skb
, int frametype
)
88 struct x25_address source_addr
, dest_addr
;
91 case X25_CALL_ACCEPTED
: {
92 struct x25_sock
*x25
= x25_sk(sk
);
95 x25
->condition
= 0x00;
100 x25
->state
= X25_STATE_3
;
101 sk
->sk_state
= TCP_ESTABLISHED
;
103 * Parse the data in the frame.
105 skb_pull(skb
, X25_STD_MIN_LEN
);
106 skb_pull(skb
, x25_addr_ntoa(skb
->data
, &source_addr
, &dest_addr
));
108 x25_parse_facilities(skb
, &x25
->facilities
,
109 &x25
->dte_facilities
,
110 &x25
->vc_facil_mask
));
112 * Copy any Call User Data.
115 skb_copy_from_linear_data(skb
,
116 x25
->calluserdata
.cuddata
,
118 x25
->calluserdata
.cudlength
= skb
->len
;
120 if (!sock_flag(sk
, SOCK_DEAD
))
121 sk
->sk_state_change(sk
);
124 case X25_CLEAR_REQUEST
:
125 x25_write_internal(sk
, X25_CLEAR_CONFIRMATION
);
126 x25_disconnect(sk
, ECONNREFUSED
, skb
->data
[3], skb
->data
[4]);
137 * State machine for state 2, Awaiting Clear Confirmation State.
138 * The handling of the timer(s) is in file x25_timer.c
139 * Handling of state 0 and connection release is in af_x25.c.
141 static int x25_state2_machine(struct sock
*sk
, struct sk_buff
*skb
, int frametype
)
145 case X25_CLEAR_REQUEST
:
146 x25_write_internal(sk
, X25_CLEAR_CONFIRMATION
);
147 x25_disconnect(sk
, 0, skb
->data
[3], skb
->data
[4]);
150 case X25_CLEAR_CONFIRMATION
:
151 x25_disconnect(sk
, 0, 0, 0);
162 * State machine for state 3, Connected State.
163 * The handling of the timer(s) is in file x25_timer.c
164 * Handling of state 0 and connection release is in af_x25.c.
166 static int x25_state3_machine(struct sock
*sk
, struct sk_buff
*skb
, int frametype
, int ns
, int nr
, int q
, int d
, int m
)
170 struct x25_sock
*x25
= x25_sk(sk
);
172 modulus
= (x25
->neighbour
->extended
) ? X25_EMODULUS
: X25_SMODULUS
;
176 case X25_RESET_REQUEST
:
177 x25_write_internal(sk
, X25_RESET_CONFIRMATION
);
179 x25
->condition
= 0x00;
184 x25_requeue_frames(sk
);
187 case X25_CLEAR_REQUEST
:
188 x25_write_internal(sk
, X25_CLEAR_CONFIRMATION
);
189 x25_disconnect(sk
, 0, skb
->data
[3], skb
->data
[4]);
194 if (!x25_validate_nr(sk
, nr
)) {
195 x25_clear_queues(sk
);
196 x25_write_internal(sk
, X25_RESET_REQUEST
);
197 x25_start_t22timer(sk
);
198 x25
->condition
= 0x00;
203 x25
->state
= X25_STATE_4
;
205 x25_frames_acked(sk
, nr
);
206 if (frametype
== X25_RNR
) {
207 x25
->condition
|= X25_COND_PEER_RX_BUSY
;
209 x25
->condition
&= ~X25_COND_PEER_RX_BUSY
;
214 case X25_DATA
: /* XXX */
215 x25
->condition
&= ~X25_COND_PEER_RX_BUSY
;
216 if ((ns
!= x25
->vr
) || !x25_validate_nr(sk
, nr
)) {
217 x25_clear_queues(sk
);
218 x25_write_internal(sk
, X25_RESET_REQUEST
);
219 x25_start_t22timer(sk
);
220 x25
->condition
= 0x00;
225 x25
->state
= X25_STATE_4
;
228 x25_frames_acked(sk
, nr
);
230 if (x25_queue_rx_frame(sk
, skb
, m
) == 0) {
231 x25
->vr
= (x25
->vr
+ 1) % modulus
;
234 /* Should never happen */
235 x25_clear_queues(sk
);
236 x25_write_internal(sk
, X25_RESET_REQUEST
);
237 x25_start_t22timer(sk
);
238 x25
->condition
= 0x00;
243 x25
->state
= X25_STATE_4
;
246 if (atomic_read(&sk
->sk_rmem_alloc
) >
248 x25
->condition
|= X25_COND_OWN_RX_BUSY
;
251 * If the window is full Ack it immediately, else
252 * start the holdback timer.
254 if (((x25
->vl
+ x25
->facilities
.winsize_in
) % modulus
) == x25
->vr
) {
255 x25
->condition
&= ~X25_COND_ACK_PENDING
;
257 x25_enquiry_response(sk
);
259 x25
->condition
|= X25_COND_ACK_PENDING
;
260 x25_start_t2timer(sk
);
264 case X25_INTERRUPT_CONFIRMATION
:
269 if (sock_flag(sk
, SOCK_URGINLINE
))
270 queued
= !sock_queue_rcv_skb(sk
, skb
);
272 skb_set_owner_r(skb
, sk
);
273 skb_queue_tail(&x25
->interrupt_in_queue
, skb
);
277 x25_write_internal(sk
, X25_INTERRUPT_CONFIRMATION
);
281 printk(KERN_WARNING
"x25: unknown %02X in state 3\n", frametype
);
289 * State machine for state 4, Awaiting Reset Confirmation State.
290 * The handling of the timer(s) is in file x25_timer.c
291 * Handling of state 0 and connection release is in af_x25.c.
293 static int x25_state4_machine(struct sock
*sk
, struct sk_buff
*skb
, int frametype
)
297 case X25_RESET_REQUEST
:
298 x25_write_internal(sk
, X25_RESET_CONFIRMATION
);
299 case X25_RESET_CONFIRMATION
: {
300 struct x25_sock
*x25
= x25_sk(sk
);
303 x25
->condition
= 0x00;
308 x25
->state
= X25_STATE_3
;
309 x25_requeue_frames(sk
);
312 case X25_CLEAR_REQUEST
:
313 x25_write_internal(sk
, X25_CLEAR_CONFIRMATION
);
314 x25_disconnect(sk
, 0, skb
->data
[3], skb
->data
[4]);
324 /* Higher level upcall for a LAPB frame */
325 int x25_process_rx_frame(struct sock
*sk
, struct sk_buff
*skb
)
327 struct x25_sock
*x25
= x25_sk(sk
);
328 int queued
= 0, frametype
, ns
, nr
, q
, d
, m
;
330 if (x25
->state
== X25_STATE_0
)
333 frametype
= x25_decode(sk
, skb
, &ns
, &nr
, &q
, &d
, &m
);
335 switch (x25
->state
) {
337 queued
= x25_state1_machine(sk
, skb
, frametype
);
340 queued
= x25_state2_machine(sk
, skb
, frametype
);
343 queued
= x25_state3_machine(sk
, skb
, frametype
, ns
, nr
, q
, d
, m
);
346 queued
= x25_state4_machine(sk
, skb
, frametype
);
355 int x25_backlog_rcv(struct sock
*sk
, struct sk_buff
*skb
)
357 int queued
= x25_process_rx_frame(sk
, skb
);