]> git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - net/x25/x25_in.c
projects / mirror_ubuntu-artful-kernel.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit...
[mirror_ubuntu-artful-kernel.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/slab.h>
27 #include <linux/errno.h>
28 #include <linux/kernel.h>
29 #include <linux/string.h>
30 #include <linux/skbuff.h>
31 #include <net/sock.h>
32 #include <net/tcp_states.h>
33 #include <net/x25.h>
34
35 static int x25_queue_rx_frame(struct sock *sk, struct sk_buff *skb, int more)
36 {
37 struct sk_buff *skbo, *skbn = skb;
38 struct x25_sock *x25 = x25_sk(sk);
39
40 if (more) {
41 x25->fraglen += skb->len;
42 skb_queue_tail(&x25->fragment_queue, skb);
43 skb_set_owner_r(skb, sk);
44 return 0;
45 }
46
47 if (!more && x25->fraglen > 0) { /* End of fragment */
48 int len = x25->fraglen + skb->len;
49
50 if ((skbn = alloc_skb(len, GFP_ATOMIC)) == NULL){
51 kfree_skb(skb);
52 return 1;
53 }
54
55 skb_queue_tail(&x25->fragment_queue, skb);
56
57 skb_reset_transport_header(skbn);
58
59 skbo = skb_dequeue(&x25->fragment_queue);
60 skb_copy_from_linear_data(skbo, skb_put(skbn, skbo->len),
61 skbo->len);
62 kfree_skb(skbo);
63
64 while ((skbo =
65 skb_dequeue(&x25->fragment_queue)) != NULL) {
66 skb_pull(skbo, (x25->neighbour->extended) ?
67 X25_EXT_MIN_LEN : X25_STD_MIN_LEN);
68 skb_copy_from_linear_data(skbo,
69 skb_put(skbn, skbo->len),
70 skbo->len);
71 kfree_skb(skbo);
72 }
73
74 x25->fraglen = 0;
75 }
76
77 skb_set_owner_r(skbn, sk);
78 skb_queue_tail(&sk->sk_receive_queue, skbn);
79 if (!sock_flag(sk, SOCK_DEAD))
80 sk->sk_data_ready(sk, skbn->len);
81
82 return 0;
83 }
84
85 /*
86 * State machine for state 1, Awaiting Call Accepted State.
87 * The handling of the timer(s) is in file x25_timer.c.
88 * Handling of state 0 and connection release is in af_x25.c.
89 */
90 static int x25_state1_machine(struct sock *sk, struct sk_buff *skb, int frametype)
91 {
92 struct x25_address source_addr, dest_addr;
93
94 switch (frametype) {
95 case X25_CALL_ACCEPTED: {
96 struct x25_sock *x25 = x25_sk(sk);
97
98 x25_stop_timer(sk);
99 x25->condition = 0x00;
100 x25->vs = 0;
101 x25->va = 0;
102 x25->vr = 0;
103 x25->vl = 0;
104 x25->state = X25_STATE_3;
105 sk->sk_state = TCP_ESTABLISHED;
106 /*
107 * Parse the data in the frame.
108 */
109 skb_pull(skb, X25_STD_MIN_LEN);
110 skb_pull(skb, x25_addr_ntoa(skb->data, &source_addr, &dest_addr));
111 skb_pull(skb,
112 x25_parse_facilities(skb, &x25->facilities,
113 &x25->dte_facilities,
114 &x25->vc_facil_mask));
115 /*
116 * Copy any Call User Data.
117 */
118 if (skb->len > 0) {
119 skb_copy_from_linear_data(skb,
120 x25->calluserdata.cuddata,
121 skb->len);
122 x25->calluserdata.cudlength = skb->len;
123 }
124 if (!sock_flag(sk, SOCK_DEAD))
125 sk->sk_state_change(sk);
126 break;
127 }
128 case X25_CLEAR_REQUEST:
129 x25_write_internal(sk, X25_CLEAR_CONFIRMATION);
130 x25_disconnect(sk, ECONNREFUSED, skb->data[3], skb->data[4]);
131 break;
132
133 default:
134 break;
135 }
136
137 return 0;
138 }
139
140 /*
141 * State machine for state 2, Awaiting Clear Confirmation State.
142 * The handling of the timer(s) is in file x25_timer.c
143 * Handling of state 0 and connection release is in af_x25.c.
144 */
145 static int x25_state2_machine(struct sock *sk, struct sk_buff *skb, int frametype)
146 {
147 switch (frametype) {
148
149 case X25_CLEAR_REQUEST:
150 x25_write_internal(sk, X25_CLEAR_CONFIRMATION);
151 x25_disconnect(sk, 0, skb->data[3], skb->data[4]);
152 break;
153
154 case X25_CLEAR_CONFIRMATION:
155 x25_disconnect(sk, 0, 0, 0);
156 break;
157
158 default:
159 break;
160 }
161
162 return 0;
163 }
164
165 /*
166 * State machine for state 3, Connected State.
167 * The handling of the timer(s) is in file x25_timer.c
168 * Handling of state 0 and connection release is in af_x25.c.
169 */
170 static int x25_state3_machine(struct sock *sk, struct sk_buff *skb, int frametype, int ns, int nr, int q, int d, int m)
171 {
172 int queued = 0;
173 int modulus;
174 struct x25_sock *x25 = x25_sk(sk);
175
176 modulus = (x25->neighbour->extended) ? X25_EMODULUS : X25_SMODULUS;
177
178 switch (frametype) {
179
180 case X25_RESET_REQUEST:
181 x25_write_internal(sk, X25_RESET_CONFIRMATION);
182 x25_stop_timer(sk);
183 x25->condition = 0x00;
184 x25->vs = 0;
185 x25->vr = 0;
186 x25->va = 0;
187 x25->vl = 0;
188 x25_requeue_frames(sk);
189 break;
190
191 case X25_CLEAR_REQUEST:
192 x25_write_internal(sk, X25_CLEAR_CONFIRMATION);
193 x25_disconnect(sk, 0, skb->data[3], skb->data[4]);
194 break;
195
196 case X25_RR:
197 case X25_RNR:
198 if (!x25_validate_nr(sk, nr)) {
199 x25_clear_queues(sk);
200 x25_write_internal(sk, X25_RESET_REQUEST);
201 x25_start_t22timer(sk);
202 x25->condition = 0x00;
203 x25->vs = 0;
204 x25->vr = 0;
205 x25->va = 0;
206 x25->vl = 0;
207 x25->state = X25_STATE_4;
208 } else {
209 x25_frames_acked(sk, nr);
210 if (frametype == X25_RNR) {
211 x25->condition |= X25_COND_PEER_RX_BUSY;
212 } else {
213 x25->condition &= ~X25_COND_PEER_RX_BUSY;
214 }
215 }
216 break;
217
218 case X25_DATA: /* XXX */
219 x25->condition &= ~X25_COND_PEER_RX_BUSY;
220 if ((ns != x25->vr) || !x25_validate_nr(sk, nr)) {
221 x25_clear_queues(sk);
222 x25_write_internal(sk, X25_RESET_REQUEST);
223 x25_start_t22timer(sk);
224 x25->condition = 0x00;
225 x25->vs = 0;
226 x25->vr = 0;
227 x25->va = 0;
228 x25->vl = 0;
229 x25->state = X25_STATE_4;
230 break;
231 }
232 x25_frames_acked(sk, nr);
233 if (ns == x25->vr) {
234 if (x25_queue_rx_frame(sk, skb, m) == 0) {
235 x25->vr = (x25->vr + 1) % modulus;
236 queued = 1;
237 } else {
238 /* Should never happen */
239 x25_clear_queues(sk);
240 x25_write_internal(sk, X25_RESET_REQUEST);
241 x25_start_t22timer(sk);
242 x25->condition = 0x00;
243 x25->vs = 0;
244 x25->vr = 0;
245 x25->va = 0;
246 x25->vl = 0;
247 x25->state = X25_STATE_4;
248 break;
249 }
250 if (atomic_read(&sk->sk_rmem_alloc) >
251 (sk->sk_rcvbuf >> 1))
252 x25->condition |= X25_COND_OWN_RX_BUSY;
253 }
254 /*
255 * If the window is full Ack it immediately, else
256 * start the holdback timer.
257 */
258 if (((x25->vl + x25->facilities.winsize_in) % modulus) == x25->vr) {
259 x25->condition &= ~X25_COND_ACK_PENDING;
260 x25_stop_timer(sk);
261 x25_enquiry_response(sk);
262 } else {
263 x25->condition |= X25_COND_ACK_PENDING;
264 x25_start_t2timer(sk);
265 }
266 break;
267
268 case X25_INTERRUPT_CONFIRMATION:
269 x25->intflag = 0;
270 break;
271
272 case X25_INTERRUPT:
273 if (sock_flag(sk, SOCK_URGINLINE))
274 queued = !sock_queue_rcv_skb(sk, skb);
275 else {
276 skb_set_owner_r(skb, sk);
277 skb_queue_tail(&x25->interrupt_in_queue, skb);
278 queued = 1;
279 }
280 sk_send_sigurg(sk);
281 x25_write_internal(sk, X25_INTERRUPT_CONFIRMATION);
282 break;
283
284 default:
285 printk(KERN_WARNING "x25: unknown %02X in state 3\n", frametype);
286 break;
287 }
288
289 return queued;
290 }
291
292 /*
293 * State machine for state 4, Awaiting Reset Confirmation State.
294 * The handling of the timer(s) is in file x25_timer.c
295 * Handling of state 0 and connection release is in af_x25.c.
296 */
297 static int x25_state4_machine(struct sock *sk, struct sk_buff *skb, int frametype)
298 {
299 switch (frametype) {
300
301 case X25_RESET_REQUEST:
302 x25_write_internal(sk, X25_RESET_CONFIRMATION);
303 case X25_RESET_CONFIRMATION: {
304 struct x25_sock *x25 = x25_sk(sk);
305
306 x25_stop_timer(sk);
307 x25->condition = 0x00;
308 x25->va = 0;
309 x25->vr = 0;
310 x25->vs = 0;
311 x25->vl = 0;
312 x25->state = X25_STATE_3;
313 x25_requeue_frames(sk);
314 break;
315 }
316 case X25_CLEAR_REQUEST:
317 x25_write_internal(sk, X25_CLEAR_CONFIRMATION);
318 x25_disconnect(sk, 0, skb->data[3], skb->data[4]);
319 break;
320
321 default:
322 break;
323 }
324
325 return 0;
326 }
327
328 /* Higher level upcall for a LAPB frame */
329 int x25_process_rx_frame(struct sock *sk, struct sk_buff *skb)
330 {
331 struct x25_sock *x25 = x25_sk(sk);
332 int queued = 0, frametype, ns, nr, q, d, m;
333
334 if (x25->state == X25_STATE_0)
335 return 0;
336
337 frametype = x25_decode(sk, skb, &ns, &nr, &q, &d, &m);
338
339 switch (x25->state) {
340 case X25_STATE_1:
341 queued = x25_state1_machine(sk, skb, frametype);
342 break;
343 case X25_STATE_2:
344 queued = x25_state2_machine(sk, skb, frametype);
345 break;
346 case X25_STATE_3:
347 queued = x25_state3_machine(sk, skb, frametype, ns, nr, q, d, m);
348 break;
349 case X25_STATE_4:
350 queued = x25_state4_machine(sk, skb, frametype);
351 break;
352 }
353
354 x25_kick(sk);
355
356 return queued;
357 }
358
359 int x25_backlog_rcv(struct sock *sk, struct sk_buff *skb)
360 {
361 int queued = x25_process_rx_frame(sk, skb);
362
363 if (!queued)
364 kfree_skb(skb);
365
366 return 0;
367 }
Ubuntu Artful kernel mirror