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);