Commit | Line | Data |
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1da177e4 LT |
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 | |
f8e1d201 | 6 | * screw up. It might even work. |
1da177e4 LT |
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. | |
f8e1d201 | 20 | * 2000-03-20 Daniela Squassoni Disabling/enabling of facilities |
1da177e4 LT |
21 | * negotiation. |
22 | * 2000-11-10 Henner Eisen Check and reset for out-of-sequence | |
23 | * i-frames. | |
24 | */ | |
25 | ||
5a0e3ad6 | 26 | #include <linux/slab.h> |
1da177e4 LT |
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> | |
c752f073 | 32 | #include <net/tcp_states.h> |
1da177e4 LT |
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 | ||
badff6d0 | 57 | skb_reset_transport_header(skbn); |
1da177e4 LT |
58 | |
59 | skbo = skb_dequeue(&x25->fragment_queue); | |
1a4e2d09 ACM |
60 | skb_copy_from_linear_data(skbo, skb_put(skbn, skbo->len), |
61 | skbo->len); | |
1da177e4 LT |
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); | |
1a4e2d09 ACM |
68 | skb_copy_from_linear_data(skbo, |
69 | skb_put(skbn, skbo->len), | |
70 | skbo->len); | |
1da177e4 LT |
71 | kfree_skb(skbo); |
72 | } | |
73 | ||
f8e1d201 | 74 | x25->fraglen = 0; |
1da177e4 LT |
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; | |
f5eb917b | 93 | int len; |
95c30430 | 94 | struct x25_sock *x25 = x25_sk(sk); |
1da177e4 LT |
95 | |
96 | switch (frametype) { | |
97 | case X25_CALL_ACCEPTED: { | |
1da177e4 LT |
98 | |
99 | x25_stop_timer(sk); | |
100 | x25->condition = 0x00; | |
101 | x25->vs = 0; | |
102 | x25->va = 0; | |
103 | x25->vr = 0; | |
104 | x25->vl = 0; | |
105 | x25->state = X25_STATE_3; | |
106 | sk->sk_state = TCP_ESTABLISHED; | |
107 | /* | |
108 | * Parse the data in the frame. | |
109 | */ | |
110 | skb_pull(skb, X25_STD_MIN_LEN); | |
f5eb917b JH |
111 | |
112 | len = x25_parse_address_block(skb, &source_addr, | |
113 | &dest_addr); | |
114 | if (len > 0) | |
115 | skb_pull(skb, len); | |
95c30430 | 116 | else if (len < 0) |
117 | goto out_clear; | |
f5eb917b JH |
118 | |
119 | len = x25_parse_facilities(skb, &x25->facilities, | |
a64b7b93 | 120 | &x25->dte_facilities, |
f5eb917b JH |
121 | &x25->vc_facil_mask); |
122 | if (len > 0) | |
123 | skb_pull(skb, len); | |
95c30430 | 124 | else if (len < 0) |
125 | goto out_clear; | |
1da177e4 LT |
126 | /* |
127 | * Copy any Call User Data. | |
128 | */ | |
091bb8ab | 129 | if (skb->len > 0) { |
d626f62b ACM |
130 | skb_copy_from_linear_data(skb, |
131 | x25->calluserdata.cuddata, | |
132 | skb->len); | |
1da177e4 LT |
133 | x25->calluserdata.cudlength = skb->len; |
134 | } | |
135 | if (!sock_flag(sk, SOCK_DEAD)) | |
136 | sk->sk_state_change(sk); | |
137 | break; | |
138 | } | |
139 | case X25_CLEAR_REQUEST: | |
140 | x25_write_internal(sk, X25_CLEAR_CONFIRMATION); | |
141 | x25_disconnect(sk, ECONNREFUSED, skb->data[3], skb->data[4]); | |
142 | break; | |
143 | ||
144 | default: | |
145 | break; | |
146 | } | |
147 | ||
148 | return 0; | |
95c30430 | 149 | |
150 | out_clear: | |
151 | x25_write_internal(sk, X25_CLEAR_REQUEST); | |
152 | x25->state = X25_STATE_2; | |
153 | x25_start_t23timer(sk); | |
154 | return 0; | |
1da177e4 LT |
155 | } |
156 | ||
157 | /* | |
158 | * State machine for state 2, Awaiting Clear Confirmation State. | |
159 | * The handling of the timer(s) is in file x25_timer.c | |
160 | * Handling of state 0 and connection release is in af_x25.c. | |
161 | */ | |
162 | static int x25_state2_machine(struct sock *sk, struct sk_buff *skb, int frametype) | |
163 | { | |
164 | switch (frametype) { | |
165 | ||
166 | case X25_CLEAR_REQUEST: | |
167 | x25_write_internal(sk, X25_CLEAR_CONFIRMATION); | |
168 | x25_disconnect(sk, 0, skb->data[3], skb->data[4]); | |
169 | break; | |
170 | ||
171 | case X25_CLEAR_CONFIRMATION: | |
172 | x25_disconnect(sk, 0, 0, 0); | |
173 | break; | |
174 | ||
175 | default: | |
176 | break; | |
177 | } | |
178 | ||
179 | return 0; | |
180 | } | |
181 | ||
182 | /* | |
183 | * State machine for state 3, Connected State. | |
184 | * The handling of the timer(s) is in file x25_timer.c | |
185 | * Handling of state 0 and connection release is in af_x25.c. | |
186 | */ | |
187 | static int x25_state3_machine(struct sock *sk, struct sk_buff *skb, int frametype, int ns, int nr, int q, int d, int m) | |
188 | { | |
189 | int queued = 0; | |
190 | int modulus; | |
191 | struct x25_sock *x25 = x25_sk(sk); | |
f8e1d201 | 192 | |
1da177e4 LT |
193 | modulus = (x25->neighbour->extended) ? X25_EMODULUS : X25_SMODULUS; |
194 | ||
195 | switch (frametype) { | |
196 | ||
197 | case X25_RESET_REQUEST: | |
198 | x25_write_internal(sk, X25_RESET_CONFIRMATION); | |
199 | x25_stop_timer(sk); | |
200 | x25->condition = 0x00; | |
201 | x25->vs = 0; | |
202 | x25->vr = 0; | |
203 | x25->va = 0; | |
204 | x25->vl = 0; | |
205 | x25_requeue_frames(sk); | |
206 | break; | |
207 | ||
208 | case X25_CLEAR_REQUEST: | |
209 | x25_write_internal(sk, X25_CLEAR_CONFIRMATION); | |
210 | x25_disconnect(sk, 0, skb->data[3], skb->data[4]); | |
211 | break; | |
212 | ||
213 | case X25_RR: | |
214 | case X25_RNR: | |
215 | if (!x25_validate_nr(sk, nr)) { | |
216 | x25_clear_queues(sk); | |
217 | x25_write_internal(sk, X25_RESET_REQUEST); | |
218 | x25_start_t22timer(sk); | |
219 | x25->condition = 0x00; | |
220 | x25->vs = 0; | |
221 | x25->vr = 0; | |
222 | x25->va = 0; | |
223 | x25->vl = 0; | |
224 | x25->state = X25_STATE_4; | |
225 | } else { | |
226 | x25_frames_acked(sk, nr); | |
227 | if (frametype == X25_RNR) { | |
228 | x25->condition |= X25_COND_PEER_RX_BUSY; | |
229 | } else { | |
230 | x25->condition &= ~X25_COND_PEER_RX_BUSY; | |
231 | } | |
232 | } | |
233 | break; | |
234 | ||
235 | case X25_DATA: /* XXX */ | |
236 | x25->condition &= ~X25_COND_PEER_RX_BUSY; | |
237 | if ((ns != x25->vr) || !x25_validate_nr(sk, nr)) { | |
238 | x25_clear_queues(sk); | |
239 | x25_write_internal(sk, X25_RESET_REQUEST); | |
240 | x25_start_t22timer(sk); | |
241 | x25->condition = 0x00; | |
242 | x25->vs = 0; | |
243 | x25->vr = 0; | |
244 | x25->va = 0; | |
245 | x25->vl = 0; | |
246 | x25->state = X25_STATE_4; | |
247 | break; | |
248 | } | |
249 | x25_frames_acked(sk, nr); | |
250 | if (ns == x25->vr) { | |
251 | if (x25_queue_rx_frame(sk, skb, m) == 0) { | |
252 | x25->vr = (x25->vr + 1) % modulus; | |
253 | queued = 1; | |
254 | } else { | |
255 | /* Should never happen */ | |
256 | x25_clear_queues(sk); | |
257 | x25_write_internal(sk, X25_RESET_REQUEST); | |
258 | x25_start_t22timer(sk); | |
259 | x25->condition = 0x00; | |
260 | x25->vs = 0; | |
261 | x25->vr = 0; | |
262 | x25->va = 0; | |
263 | x25->vl = 0; | |
264 | x25->state = X25_STATE_4; | |
265 | break; | |
266 | } | |
267 | if (atomic_read(&sk->sk_rmem_alloc) > | |
6bf1574e | 268 | (sk->sk_rcvbuf >> 1)) |
1da177e4 LT |
269 | x25->condition |= X25_COND_OWN_RX_BUSY; |
270 | } | |
271 | /* | |
272 | * If the window is full Ack it immediately, else | |
273 | * start the holdback timer. | |
274 | */ | |
275 | if (((x25->vl + x25->facilities.winsize_in) % modulus) == x25->vr) { | |
276 | x25->condition &= ~X25_COND_ACK_PENDING; | |
277 | x25_stop_timer(sk); | |
278 | x25_enquiry_response(sk); | |
279 | } else { | |
280 | x25->condition |= X25_COND_ACK_PENDING; | |
281 | x25_start_t2timer(sk); | |
282 | } | |
283 | break; | |
284 | ||
285 | case X25_INTERRUPT_CONFIRMATION: | |
b7792e34 | 286 | clear_bit(X25_INTERRUPT_FLAG, &x25->flags); |
1da177e4 LT |
287 | break; |
288 | ||
289 | case X25_INTERRUPT: | |
290 | if (sock_flag(sk, SOCK_URGINLINE)) | |
291 | queued = !sock_queue_rcv_skb(sk, skb); | |
292 | else { | |
293 | skb_set_owner_r(skb, sk); | |
294 | skb_queue_tail(&x25->interrupt_in_queue, skb); | |
295 | queued = 1; | |
296 | } | |
297 | sk_send_sigurg(sk); | |
298 | x25_write_internal(sk, X25_INTERRUPT_CONFIRMATION); | |
299 | break; | |
300 | ||
301 | default: | |
302 | printk(KERN_WARNING "x25: unknown %02X in state 3\n", frametype); | |
303 | break; | |
304 | } | |
305 | ||
306 | return queued; | |
307 | } | |
308 | ||
309 | /* | |
310 | * State machine for state 4, Awaiting Reset Confirmation State. | |
311 | * The handling of the timer(s) is in file x25_timer.c | |
312 | * Handling of state 0 and connection release is in af_x25.c. | |
313 | */ | |
314 | static int x25_state4_machine(struct sock *sk, struct sk_buff *skb, int frametype) | |
315 | { | |
316 | switch (frametype) { | |
317 | ||
318 | case X25_RESET_REQUEST: | |
319 | x25_write_internal(sk, X25_RESET_CONFIRMATION); | |
320 | case X25_RESET_CONFIRMATION: { | |
321 | struct x25_sock *x25 = x25_sk(sk); | |
322 | ||
323 | x25_stop_timer(sk); | |
324 | x25->condition = 0x00; | |
325 | x25->va = 0; | |
326 | x25->vr = 0; | |
327 | x25->vs = 0; | |
328 | x25->vl = 0; | |
329 | x25->state = X25_STATE_3; | |
330 | x25_requeue_frames(sk); | |
331 | break; | |
332 | } | |
333 | case X25_CLEAR_REQUEST: | |
334 | x25_write_internal(sk, X25_CLEAR_CONFIRMATION); | |
335 | x25_disconnect(sk, 0, skb->data[3], skb->data[4]); | |
336 | break; | |
337 | ||
338 | default: | |
339 | break; | |
340 | } | |
341 | ||
342 | return 0; | |
343 | } | |
344 | ||
345 | /* Higher level upcall for a LAPB frame */ | |
346 | int x25_process_rx_frame(struct sock *sk, struct sk_buff *skb) | |
347 | { | |
348 | struct x25_sock *x25 = x25_sk(sk); | |
349 | int queued = 0, frametype, ns, nr, q, d, m; | |
350 | ||
351 | if (x25->state == X25_STATE_0) | |
352 | return 0; | |
353 | ||
354 | frametype = x25_decode(sk, skb, &ns, &nr, &q, &d, &m); | |
355 | ||
356 | switch (x25->state) { | |
357 | case X25_STATE_1: | |
358 | queued = x25_state1_machine(sk, skb, frametype); | |
359 | break; | |
360 | case X25_STATE_2: | |
361 | queued = x25_state2_machine(sk, skb, frametype); | |
362 | break; | |
363 | case X25_STATE_3: | |
364 | queued = x25_state3_machine(sk, skb, frametype, ns, nr, q, d, m); | |
365 | break; | |
366 | case X25_STATE_4: | |
367 | queued = x25_state4_machine(sk, skb, frametype); | |
368 | break; | |
369 | } | |
370 | ||
371 | x25_kick(sk); | |
372 | ||
373 | return queued; | |
374 | } | |
375 | ||
376 | int x25_backlog_rcv(struct sock *sk, struct sk_buff *skb) | |
377 | { | |
378 | int queued = x25_process_rx_frame(sk, skb); | |
379 | ||
380 | if (!queued) | |
381 | kfree_skb(skb); | |
382 | ||
383 | return 0; | |
384 | } |