[TCP]: Move the tcp sock states to net/tcp_states.h
[linux-2.6.git] / net / x25 / x25_in.c
1 /*
2  *      X.25 Packet Layer release 002
3  *
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. 
7  *
8  *      This code REQUIRES 2.1.15 or higher
9  *
10  *      This module:
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.
15  *
16  *      History
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 
21  *                                        negotiation.
22  *      2000-11-10      Henner Eisen      Check and reset for out-of-sequence
23  *                                        i-frames.
24  */
25
26 #include <linux/errno.h>
27 #include <linux/kernel.h>
28 #include <linux/string.h>
29 #include <linux/skbuff.h>
30 #include <net/sock.h>
31 #include <net/tcp_states.h>
32 #include <net/x25.h>
33
34 static int x25_queue_rx_frame(struct sock *sk, struct sk_buff *skb, int more)
35 {
36         struct sk_buff *skbo, *skbn = skb;
37         struct x25_sock *x25 = x25_sk(sk);
38
39         if (more) {
40                 x25->fraglen += skb->len;
41                 skb_queue_tail(&x25->fragment_queue, skb);
42                 skb_set_owner_r(skb, sk);
43                 return 0;
44         }
45
46         if (!more && x25->fraglen > 0) {        /* End of fragment */
47                 int len = x25->fraglen + skb->len;
48
49                 if ((skbn = alloc_skb(len, GFP_ATOMIC)) == NULL){
50                         kfree_skb(skb);
51                         return 1;
52                 }
53
54                 skb_queue_tail(&x25->fragment_queue, skb);
55
56                 skbn->h.raw = skbn->data;
57
58                 skbo = skb_dequeue(&x25->fragment_queue);
59                 memcpy(skb_put(skbn, skbo->len), skbo->data, skbo->len);
60                 kfree_skb(skbo);
61
62                 while ((skbo =
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);
67                         kfree_skb(skbo);
68                 }
69
70                 x25->fraglen = 0;               
71         }
72
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);
77
78         return 0;
79 }
80
81 /*
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.
85  */
86 static int x25_state1_machine(struct sock *sk, struct sk_buff *skb, int frametype)
87 {
88         struct x25_address source_addr, dest_addr;
89
90         switch (frametype) {
91                 case X25_CALL_ACCEPTED: {
92                         struct x25_sock *x25 = x25_sk(sk);
93
94                         x25_stop_timer(sk);
95                         x25->condition = 0x00;
96                         x25->vs        = 0;
97                         x25->va        = 0;
98                         x25->vr        = 0;
99                         x25->vl        = 0;
100                         x25->state     = X25_STATE_3;
101                         sk->sk_state   = TCP_ESTABLISHED;
102                         /*
103                          *      Parse the data in the frame.
104                          */
105                         skb_pull(skb, X25_STD_MIN_LEN);
106                         skb_pull(skb, x25_addr_ntoa(skb->data, &source_addr, &dest_addr));
107                         skb_pull(skb,
108                                  x25_parse_facilities(skb, &x25->facilities,
109                                                       &x25->vc_facil_mask));
110                         /*
111                          *      Copy any Call User Data.
112                          */
113                         if (skb->len >= 0) {
114                                 memcpy(x25->calluserdata.cuddata, skb->data,
115                                        skb->len);
116                                 x25->calluserdata.cudlength = skb->len;
117                         }
118                         if (!sock_flag(sk, SOCK_DEAD))
119                                 sk->sk_state_change(sk);
120                         break;
121                 }
122                 case X25_CLEAR_REQUEST:
123                         x25_write_internal(sk, X25_CLEAR_CONFIRMATION);
124                         x25_disconnect(sk, ECONNREFUSED, skb->data[3], skb->data[4]);
125                         break;
126
127                 default:
128                         break;
129         }
130
131         return 0;
132 }
133
134 /*
135  * State machine for state 2, Awaiting Clear Confirmation State.
136  * The handling of the timer(s) is in file x25_timer.c
137  * Handling of state 0 and connection release is in af_x25.c.
138  */
139 static int x25_state2_machine(struct sock *sk, struct sk_buff *skb, int frametype)
140 {
141         switch (frametype) {
142
143                 case X25_CLEAR_REQUEST:
144                         x25_write_internal(sk, X25_CLEAR_CONFIRMATION);
145                         x25_disconnect(sk, 0, skb->data[3], skb->data[4]);
146                         break;
147
148                 case X25_CLEAR_CONFIRMATION:
149                         x25_disconnect(sk, 0, 0, 0);
150                         break;
151
152                 default:
153                         break;
154         }
155
156         return 0;
157 }
158
159 /*
160  * State machine for state 3, Connected State.
161  * The handling of the timer(s) is in file x25_timer.c
162  * Handling of state 0 and connection release is in af_x25.c.
163  */
164 static int x25_state3_machine(struct sock *sk, struct sk_buff *skb, int frametype, int ns, int nr, int q, int d, int m)
165 {
166         int queued = 0;
167         int modulus;
168         struct x25_sock *x25 = x25_sk(sk);
169         
170         modulus = (x25->neighbour->extended) ? X25_EMODULUS : X25_SMODULUS;
171
172         switch (frametype) {
173
174                 case X25_RESET_REQUEST:
175                         x25_write_internal(sk, X25_RESET_CONFIRMATION);
176                         x25_stop_timer(sk);
177                         x25->condition = 0x00;
178                         x25->vs        = 0;
179                         x25->vr        = 0;
180                         x25->va        = 0;
181                         x25->vl        = 0;
182                         x25_requeue_frames(sk);
183                         break;
184
185                 case X25_CLEAR_REQUEST:
186                         x25_write_internal(sk, X25_CLEAR_CONFIRMATION);
187                         x25_disconnect(sk, 0, skb->data[3], skb->data[4]);
188                         break;
189
190                 case X25_RR:
191                 case X25_RNR:
192                         if (!x25_validate_nr(sk, nr)) {
193                                 x25_clear_queues(sk);
194                                 x25_write_internal(sk, X25_RESET_REQUEST);
195                                 x25_start_t22timer(sk);
196                                 x25->condition = 0x00;
197                                 x25->vs        = 0;
198                                 x25->vr        = 0;
199                                 x25->va        = 0;
200                                 x25->vl        = 0;
201                                 x25->state     = X25_STATE_4;
202                         } else {
203                                 x25_frames_acked(sk, nr);
204                                 if (frametype == X25_RNR) {
205                                         x25->condition |= X25_COND_PEER_RX_BUSY;
206                                 } else {
207                                         x25->condition &= ~X25_COND_PEER_RX_BUSY;
208                                 }
209                         }
210                         break;
211
212                 case X25_DATA:  /* XXX */
213                         x25->condition &= ~X25_COND_PEER_RX_BUSY;
214                         if ((ns != x25->vr) || !x25_validate_nr(sk, nr)) {
215                                 x25_clear_queues(sk);
216                                 x25_write_internal(sk, X25_RESET_REQUEST);
217                                 x25_start_t22timer(sk);
218                                 x25->condition = 0x00;
219                                 x25->vs        = 0;
220                                 x25->vr        = 0;
221                                 x25->va        = 0;
222                                 x25->vl        = 0;
223                                 x25->state     = X25_STATE_4;
224                                 break;
225                         }
226                         x25_frames_acked(sk, nr);
227                         if (ns == x25->vr) {
228                                 if (x25_queue_rx_frame(sk, skb, m) == 0) {
229                                         x25->vr = (x25->vr + 1) % modulus;
230                                         queued = 1;
231                                 } else {
232                                         /* Should never happen */
233                                         x25_clear_queues(sk);
234                                         x25_write_internal(sk, X25_RESET_REQUEST);
235                                         x25_start_t22timer(sk);
236                                         x25->condition = 0x00;
237                                         x25->vs        = 0;
238                                         x25->vr        = 0;
239                                         x25->va        = 0;
240                                         x25->vl        = 0;
241                                         x25->state     = X25_STATE_4;
242                                         break;
243                                 }
244                                 if (atomic_read(&sk->sk_rmem_alloc) >
245                                     (sk->sk_rcvbuf / 2))
246                                         x25->condition |= X25_COND_OWN_RX_BUSY;
247                         }
248                         /*
249                          *      If the window is full Ack it immediately, else
250                          *      start the holdback timer.
251                          */
252                         if (((x25->vl + x25->facilities.winsize_in) % modulus) == x25->vr) {
253                                 x25->condition &= ~X25_COND_ACK_PENDING;
254                                 x25_stop_timer(sk);
255                                 x25_enquiry_response(sk);
256                         } else {
257                                 x25->condition |= X25_COND_ACK_PENDING;
258                                 x25_start_t2timer(sk);
259                         }
260                         break;
261
262                 case X25_INTERRUPT_CONFIRMATION:
263                         x25->intflag = 0;
264                         break;
265
266                 case X25_INTERRUPT:
267                         if (sock_flag(sk, SOCK_URGINLINE))
268                                 queued = !sock_queue_rcv_skb(sk, skb);
269                         else {
270                                 skb_set_owner_r(skb, sk);
271                                 skb_queue_tail(&x25->interrupt_in_queue, skb);
272                                 queued = 1;
273                         }
274                         sk_send_sigurg(sk);
275                         x25_write_internal(sk, X25_INTERRUPT_CONFIRMATION);
276                         break;
277
278                 default:
279                         printk(KERN_WARNING "x25: unknown %02X in state 3\n", frametype);
280                         break;
281         }
282
283         return queued;
284 }
285
286 /*
287  * State machine for state 4, Awaiting Reset Confirmation State.
288  * The handling of the timer(s) is in file x25_timer.c
289  * Handling of state 0 and connection release is in af_x25.c.
290  */
291 static int x25_state4_machine(struct sock *sk, struct sk_buff *skb, int frametype)
292 {
293         switch (frametype) {
294
295                 case X25_RESET_REQUEST:
296                         x25_write_internal(sk, X25_RESET_CONFIRMATION);
297                 case X25_RESET_CONFIRMATION: {
298                         struct x25_sock *x25 = x25_sk(sk);
299
300                         x25_stop_timer(sk);
301                         x25->condition = 0x00;
302                         x25->va        = 0;
303                         x25->vr        = 0;
304                         x25->vs        = 0;
305                         x25->vl        = 0;
306                         x25->state     = X25_STATE_3;
307                         x25_requeue_frames(sk);
308                         break;
309                 }
310                 case X25_CLEAR_REQUEST:
311                         x25_write_internal(sk, X25_CLEAR_CONFIRMATION);
312                         x25_disconnect(sk, 0, skb->data[3], skb->data[4]);
313                         break;
314
315                 default:
316                         break;
317         }
318
319         return 0;
320 }
321
322 /* Higher level upcall for a LAPB frame */
323 int x25_process_rx_frame(struct sock *sk, struct sk_buff *skb)
324 {
325         struct x25_sock *x25 = x25_sk(sk);
326         int queued = 0, frametype, ns, nr, q, d, m;
327
328         if (x25->state == X25_STATE_0)
329                 return 0;
330
331         frametype = x25_decode(sk, skb, &ns, &nr, &q, &d, &m);
332
333         switch (x25->state) {
334                 case X25_STATE_1:
335                         queued = x25_state1_machine(sk, skb, frametype);
336                         break;
337                 case X25_STATE_2:
338                         queued = x25_state2_machine(sk, skb, frametype);
339                         break;
340                 case X25_STATE_3:
341                         queued = x25_state3_machine(sk, skb, frametype, ns, nr, q, d, m);
342                         break;
343                 case X25_STATE_4:
344                         queued = x25_state4_machine(sk, skb, frametype);
345                         break;
346         }
347
348         x25_kick(sk);
349
350         return queued;
351 }
352
353 int x25_backlog_rcv(struct sock *sk, struct sk_buff *skb)
354 {
355         int queued = x25_process_rx_frame(sk, skb);
356
357         if (!queued)
358                 kfree_skb(skb);
359
360         return 0;
361 }