xref: /openbmc/linux/net/llc/llc_c_ac.c (revision e868d61272caa648214046a096e5a6bfc068dc8c)
1 /*
2  * llc_c_ac.c - actions performed during connection state transition.
3  *
4  * Description:
5  *   Functions in this module are implementation of connection component actions
6  *   Details of actions can be found in IEEE-802.2 standard document.
7  *   All functions have one connection and one event as input argument. All of
8  *   them return 0 On success and 1 otherwise.
9  *
10  * Copyright (c) 1997 by Procom Technology, Inc.
11  * 		 2001-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
12  *
13  * This program can be redistributed or modified under the terms of the
14  * GNU General Public License as published by the Free Software Foundation.
15  * This program is distributed without any warranty or implied warranty
16  * of merchantability or fitness for a particular purpose.
17  *
18  * See the GNU General Public License for more details.
19  */
20 #include <linux/netdevice.h>
21 #include <net/llc_conn.h>
22 #include <net/llc_sap.h>
23 #include <net/sock.h>
24 #include <net/llc_c_ev.h>
25 #include <net/llc_c_ac.h>
26 #include <net/llc_c_st.h>
27 #include <net/llc_pdu.h>
28 #include <net/llc.h>
29 
30 
31 static int llc_conn_ac_inc_vs_by_1(struct sock *sk, struct sk_buff *skb);
32 static void llc_process_tmr_ev(struct sock *sk, struct sk_buff *skb);
33 static int llc_conn_ac_data_confirm(struct sock *sk, struct sk_buff *ev);
34 
35 static int llc_conn_ac_inc_npta_value(struct sock *sk, struct sk_buff *skb);
36 
37 static int llc_conn_ac_send_rr_rsp_f_set_ackpf(struct sock *sk,
38 					       struct sk_buff *skb);
39 
40 static int llc_conn_ac_set_p_flag_1(struct sock *sk, struct sk_buff *skb);
41 
42 #define INCORRECT 0
43 
44 int llc_conn_ac_clear_remote_busy(struct sock *sk, struct sk_buff *skb)
45 {
46 	struct llc_sock *llc = llc_sk(sk);
47 
48 	if (llc->remote_busy_flag) {
49 		u8 nr;
50 		struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
51 
52 		llc->remote_busy_flag = 0;
53 		del_timer(&llc->busy_state_timer.timer);
54 		nr = LLC_I_GET_NR(pdu);
55 		llc_conn_resend_i_pdu_as_cmd(sk, nr, 0);
56 	}
57 	return 0;
58 }
59 
60 int llc_conn_ac_conn_ind(struct sock *sk, struct sk_buff *skb)
61 {
62 	struct llc_conn_state_ev *ev = llc_conn_ev(skb);
63 
64 	ev->ind_prim = LLC_CONN_PRIM;
65 	return 0;
66 }
67 
68 int llc_conn_ac_conn_confirm(struct sock *sk, struct sk_buff *skb)
69 {
70 	struct llc_conn_state_ev *ev = llc_conn_ev(skb);
71 
72 	ev->cfm_prim = LLC_CONN_PRIM;
73 	return 0;
74 }
75 
76 static int llc_conn_ac_data_confirm(struct sock *sk, struct sk_buff *skb)
77 {
78 	struct llc_conn_state_ev *ev = llc_conn_ev(skb);
79 
80 	ev->cfm_prim = LLC_DATA_PRIM;
81 	return 0;
82 }
83 
84 int llc_conn_ac_data_ind(struct sock *sk, struct sk_buff *skb)
85 {
86 	llc_conn_rtn_pdu(sk, skb);
87 	return 0;
88 }
89 
90 int llc_conn_ac_disc_ind(struct sock *sk, struct sk_buff *skb)
91 {
92 	struct llc_conn_state_ev *ev = llc_conn_ev(skb);
93 	u8 reason = 0;
94 	int rc = 0;
95 
96 	if (ev->type == LLC_CONN_EV_TYPE_PDU) {
97 		struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
98 
99 		if (LLC_PDU_IS_RSP(pdu) &&
100 		    LLC_PDU_TYPE_IS_U(pdu) &&
101 		    LLC_U_PDU_RSP(pdu) == LLC_2_PDU_RSP_DM)
102 			reason = LLC_DISC_REASON_RX_DM_RSP_PDU;
103 		else if (LLC_PDU_IS_CMD(pdu) &&
104 			   LLC_PDU_TYPE_IS_U(pdu) &&
105 			   LLC_U_PDU_CMD(pdu) == LLC_2_PDU_CMD_DISC)
106 			reason = LLC_DISC_REASON_RX_DISC_CMD_PDU;
107 	} else if (ev->type == LLC_CONN_EV_TYPE_ACK_TMR)
108 		reason = LLC_DISC_REASON_ACK_TMR_EXP;
109 	else
110 		rc = -EINVAL;
111 	if (!rc) {
112 		ev->reason   = reason;
113 		ev->ind_prim = LLC_DISC_PRIM;
114 	}
115 	return rc;
116 }
117 
118 int llc_conn_ac_disc_confirm(struct sock *sk, struct sk_buff *skb)
119 {
120 	struct llc_conn_state_ev *ev = llc_conn_ev(skb);
121 
122 	ev->reason   = ev->status;
123 	ev->cfm_prim = LLC_DISC_PRIM;
124 	return 0;
125 }
126 
127 int llc_conn_ac_rst_ind(struct sock *sk, struct sk_buff *skb)
128 {
129 	u8 reason = 0;
130 	int rc = 1;
131 	struct llc_conn_state_ev *ev = llc_conn_ev(skb);
132 	struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
133 	struct llc_sock *llc = llc_sk(sk);
134 
135 	switch (ev->type) {
136 	case LLC_CONN_EV_TYPE_PDU:
137 		if (LLC_PDU_IS_RSP(pdu) &&
138 		    LLC_PDU_TYPE_IS_U(pdu) &&
139 		    LLC_U_PDU_RSP(pdu) == LLC_2_PDU_RSP_FRMR) {
140 			reason = LLC_RESET_REASON_LOCAL;
141 			rc = 0;
142 		} else if (LLC_PDU_IS_CMD(pdu) &&
143 			   LLC_PDU_TYPE_IS_U(pdu) &&
144 			   LLC_U_PDU_CMD(pdu) == LLC_2_PDU_CMD_SABME) {
145 			reason = LLC_RESET_REASON_REMOTE;
146 			rc = 0;
147 		}
148 		break;
149 	case LLC_CONN_EV_TYPE_ACK_TMR:
150 	case LLC_CONN_EV_TYPE_P_TMR:
151 	case LLC_CONN_EV_TYPE_REJ_TMR:
152 	case LLC_CONN_EV_TYPE_BUSY_TMR:
153 		if (llc->retry_count > llc->n2) {
154 			reason = LLC_RESET_REASON_LOCAL;
155 			rc = 0;
156 		}
157 		break;
158 	}
159 	if (!rc) {
160 		ev->reason   = reason;
161 		ev->ind_prim = LLC_RESET_PRIM;
162 	}
163 	return rc;
164 }
165 
166 int llc_conn_ac_rst_confirm(struct sock *sk, struct sk_buff *skb)
167 {
168 	struct llc_conn_state_ev *ev = llc_conn_ev(skb);
169 
170 	ev->reason   = 0;
171 	ev->cfm_prim = LLC_RESET_PRIM;
172 	return 0;
173 }
174 
175 int llc_conn_ac_clear_remote_busy_if_f_eq_1(struct sock *sk,
176 					    struct sk_buff *skb)
177 {
178 	struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
179 
180 	if (LLC_PDU_IS_RSP(pdu) &&
181 	    LLC_PDU_TYPE_IS_I(pdu) &&
182 	    LLC_I_PF_IS_1(pdu) && llc_sk(sk)->ack_pf)
183 		llc_conn_ac_clear_remote_busy(sk, skb);
184 	return 0;
185 }
186 
187 int llc_conn_ac_stop_rej_tmr_if_data_flag_eq_2(struct sock *sk,
188 					       struct sk_buff *skb)
189 {
190 	struct llc_sock *llc = llc_sk(sk);
191 
192 	if (llc->data_flag == 2)
193 		del_timer(&llc->rej_sent_timer.timer);
194 	return 0;
195 }
196 
197 int llc_conn_ac_send_disc_cmd_p_set_x(struct sock *sk, struct sk_buff *skb)
198 {
199 	int rc = -ENOBUFS;
200 	struct llc_sock *llc = llc_sk(sk);
201 	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev);
202 
203 	if (nskb) {
204 		struct llc_sap *sap = llc->sap;
205 
206 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
207 				    llc->daddr.lsap, LLC_PDU_CMD);
208 		llc_pdu_init_as_disc_cmd(nskb, 1);
209 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
210 		if (unlikely(rc))
211 			goto free;
212 		llc_conn_send_pdu(sk, nskb);
213 		llc_conn_ac_set_p_flag_1(sk, skb);
214 	}
215 out:
216 	return rc;
217 free:
218 	kfree_skb(nskb);
219 	goto out;
220 }
221 
222 int llc_conn_ac_send_dm_rsp_f_set_p(struct sock *sk, struct sk_buff *skb)
223 {
224 	int rc = -ENOBUFS;
225 	struct llc_sock *llc = llc_sk(sk);
226 	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev);
227 
228 	if (nskb) {
229 		struct llc_sap *sap = llc->sap;
230 		u8 f_bit;
231 
232 		llc_pdu_decode_pf_bit(skb, &f_bit);
233 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
234 				    llc->daddr.lsap, LLC_PDU_RSP);
235 		llc_pdu_init_as_dm_rsp(nskb, f_bit);
236 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
237 		if (unlikely(rc))
238 			goto free;
239 		llc_conn_send_pdu(sk, nskb);
240 	}
241 out:
242 	return rc;
243 free:
244 	kfree_skb(nskb);
245 	goto out;
246 }
247 
248 int llc_conn_ac_send_dm_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
249 {
250 	int rc = -ENOBUFS;
251 	struct llc_sock *llc = llc_sk(sk);
252 	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev);
253 
254 	if (nskb) {
255 		struct llc_sap *sap = llc->sap;
256 
257 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
258 				    llc->daddr.lsap, LLC_PDU_RSP);
259 		llc_pdu_init_as_dm_rsp(nskb, 1);
260 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
261 		if (unlikely(rc))
262 			goto free;
263 		llc_conn_send_pdu(sk, nskb);
264 	}
265 out:
266 	return rc;
267 free:
268 	kfree_skb(nskb);
269 	goto out;
270 }
271 
272 int llc_conn_ac_send_frmr_rsp_f_set_x(struct sock *sk, struct sk_buff *skb)
273 {
274 	u8 f_bit;
275 	int rc = -ENOBUFS;
276 	struct sk_buff *nskb;
277 	struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
278 	struct llc_sock *llc = llc_sk(sk);
279 
280 	llc->rx_pdu_hdr = *((u32 *)pdu);
281 	if (LLC_PDU_IS_CMD(pdu))
282 		llc_pdu_decode_pf_bit(skb, &f_bit);
283 	else
284 		f_bit = 0;
285 	nskb = llc_alloc_frame(sk, llc->dev);
286 	if (nskb) {
287 		struct llc_sap *sap = llc->sap;
288 
289 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
290 				    llc->daddr.lsap, LLC_PDU_RSP);
291 		llc_pdu_init_as_frmr_rsp(nskb, pdu, f_bit, llc->vS,
292 					 llc->vR, INCORRECT);
293 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
294 		if (unlikely(rc))
295 			goto free;
296 		llc_conn_send_pdu(sk, nskb);
297 	}
298 out:
299 	return rc;
300 free:
301 	kfree_skb(nskb);
302 	goto out;
303 }
304 
305 int llc_conn_ac_resend_frmr_rsp_f_set_0(struct sock *sk, struct sk_buff *skb)
306 {
307 	int rc = -ENOBUFS;
308 	struct llc_sock *llc = llc_sk(sk);
309 	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev);
310 
311 	if (nskb) {
312 		struct llc_sap *sap = llc->sap;
313 		struct llc_pdu_sn *pdu = (struct llc_pdu_sn *)&llc->rx_pdu_hdr;
314 
315 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
316 				    llc->daddr.lsap, LLC_PDU_RSP);
317 		llc_pdu_init_as_frmr_rsp(nskb, pdu, 0, llc->vS,
318 					 llc->vR, INCORRECT);
319 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
320 		if (unlikely(rc))
321 			goto free;
322 		llc_conn_send_pdu(sk, nskb);
323 	}
324 out:
325 	return rc;
326 free:
327 	kfree_skb(nskb);
328 	goto out;
329 }
330 
331 int llc_conn_ac_resend_frmr_rsp_f_set_p(struct sock *sk, struct sk_buff *skb)
332 {
333 	u8 f_bit;
334 	int rc = -ENOBUFS;
335 	struct sk_buff *nskb;
336 	struct llc_sock *llc = llc_sk(sk);
337 
338 	llc_pdu_decode_pf_bit(skb, &f_bit);
339 	nskb = llc_alloc_frame(sk, llc->dev);
340 	if (nskb) {
341 		struct llc_sap *sap = llc->sap;
342 		struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
343 
344 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
345 				    llc->daddr.lsap, LLC_PDU_RSP);
346 		llc_pdu_init_as_frmr_rsp(nskb, pdu, f_bit, llc->vS,
347 					 llc->vR, INCORRECT);
348 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
349 		if (unlikely(rc))
350 			goto free;
351 		llc_conn_send_pdu(sk, nskb);
352 	}
353 out:
354 	return rc;
355 free:
356 	kfree_skb(nskb);
357 	goto out;
358 }
359 
360 int llc_conn_ac_send_i_cmd_p_set_1(struct sock *sk, struct sk_buff *skb)
361 {
362 	int rc;
363 	struct llc_sock *llc = llc_sk(sk);
364 	struct llc_sap *sap = llc->sap;
365 
366 	llc_pdu_header_init(skb, LLC_PDU_TYPE_I, sap->laddr.lsap,
367 			    llc->daddr.lsap, LLC_PDU_CMD);
368 	llc_pdu_init_as_i_cmd(skb, 1, llc->vS, llc->vR);
369 	rc = llc_mac_hdr_init(skb, llc->dev->dev_addr, llc->daddr.mac);
370 	if (likely(!rc)) {
371 		llc_conn_send_pdu(sk, skb);
372 		llc_conn_ac_inc_vs_by_1(sk, skb);
373 	}
374 	return rc;
375 }
376 
377 static int llc_conn_ac_send_i_cmd_p_set_0(struct sock *sk, struct sk_buff *skb)
378 {
379 	int rc;
380 	struct llc_sock *llc = llc_sk(sk);
381 	struct llc_sap *sap = llc->sap;
382 
383 	llc_pdu_header_init(skb, LLC_PDU_TYPE_I, sap->laddr.lsap,
384 			    llc->daddr.lsap, LLC_PDU_CMD);
385 	llc_pdu_init_as_i_cmd(skb, 0, llc->vS, llc->vR);
386 	rc = llc_mac_hdr_init(skb, llc->dev->dev_addr, llc->daddr.mac);
387 	if (likely(!rc)) {
388 		llc_conn_send_pdu(sk, skb);
389 		llc_conn_ac_inc_vs_by_1(sk, skb);
390 	}
391 	return rc;
392 }
393 
394 int llc_conn_ac_send_i_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
395 {
396 	int rc;
397 	struct llc_sock *llc = llc_sk(sk);
398 	struct llc_sap *sap = llc->sap;
399 
400 	llc_pdu_header_init(skb, LLC_PDU_TYPE_I, sap->laddr.lsap,
401 			    llc->daddr.lsap, LLC_PDU_CMD);
402 	llc_pdu_init_as_i_cmd(skb, 0, llc->vS, llc->vR);
403 	rc = llc_mac_hdr_init(skb, llc->dev->dev_addr, llc->daddr.mac);
404 	if (likely(!rc)) {
405 		llc_conn_send_pdu(sk, skb);
406 		llc_conn_ac_inc_vs_by_1(sk, skb);
407 	}
408 	return 0;
409 }
410 
411 int llc_conn_ac_resend_i_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
412 {
413 	struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
414 	u8 nr = LLC_I_GET_NR(pdu);
415 
416 	llc_conn_resend_i_pdu_as_cmd(sk, nr, 0);
417 	return 0;
418 }
419 
420 int llc_conn_ac_resend_i_xxx_x_set_0_or_send_rr(struct sock *sk,
421 						struct sk_buff *skb)
422 {
423 	u8 nr;
424 	struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
425 	int rc = -ENOBUFS;
426 	struct llc_sock *llc = llc_sk(sk);
427 	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev);
428 
429 	if (nskb) {
430 		struct llc_sap *sap = llc->sap;
431 
432 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
433 				    llc->daddr.lsap, LLC_PDU_RSP);
434 		llc_pdu_init_as_rr_rsp(nskb, 0, llc->vR);
435 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
436 		if (likely(!rc))
437 			llc_conn_send_pdu(sk, nskb);
438 		else
439 			kfree_skb(skb);
440 	}
441 	if (rc) {
442 		nr = LLC_I_GET_NR(pdu);
443 		rc = 0;
444 		llc_conn_resend_i_pdu_as_cmd(sk, nr, 0);
445 	}
446 	return rc;
447 }
448 
449 int llc_conn_ac_resend_i_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
450 {
451 	struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
452 	u8 nr = LLC_I_GET_NR(pdu);
453 
454 	llc_conn_resend_i_pdu_as_rsp(sk, nr, 1);
455 	return 0;
456 }
457 
458 int llc_conn_ac_send_rej_cmd_p_set_1(struct sock *sk, struct sk_buff *skb)
459 {
460 	int rc = -ENOBUFS;
461 	struct llc_sock *llc = llc_sk(sk);
462 	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev);
463 
464 	if (nskb) {
465 		struct llc_sap *sap = llc->sap;
466 
467 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
468 				    llc->daddr.lsap, LLC_PDU_CMD);
469 		llc_pdu_init_as_rej_cmd(nskb, 1, llc->vR);
470 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
471 		if (unlikely(rc))
472 			goto free;
473 		llc_conn_send_pdu(sk, nskb);
474 	}
475 out:
476 	return rc;
477 free:
478 	kfree_skb(nskb);
479 	goto out;
480 }
481 
482 int llc_conn_ac_send_rej_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
483 {
484 	int rc = -ENOBUFS;
485 	struct llc_sock *llc = llc_sk(sk);
486 	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev);
487 
488 	if (nskb) {
489 		struct llc_sap *sap = llc->sap;
490 
491 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
492 				    llc->daddr.lsap, LLC_PDU_RSP);
493 		llc_pdu_init_as_rej_rsp(nskb, 1, llc->vR);
494 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
495 		if (unlikely(rc))
496 			goto free;
497 		llc_conn_send_pdu(sk, nskb);
498 	}
499 out:
500 	return rc;
501 free:
502 	kfree_skb(nskb);
503 	goto out;
504 }
505 
506 int llc_conn_ac_send_rej_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
507 {
508 	int rc = -ENOBUFS;
509 	struct llc_sock *llc = llc_sk(sk);
510 	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev);
511 
512 	if (nskb) {
513 		struct llc_sap *sap = llc->sap;
514 
515 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
516 				    llc->daddr.lsap, LLC_PDU_RSP);
517 		llc_pdu_init_as_rej_rsp(nskb, 0, llc->vR);
518 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
519 		if (unlikely(rc))
520 			goto free;
521 		llc_conn_send_pdu(sk, nskb);
522 	}
523 out:
524 	return rc;
525 free:
526 	kfree_skb(nskb);
527 	goto out;
528 }
529 
530 int llc_conn_ac_send_rnr_cmd_p_set_1(struct sock *sk, struct sk_buff *skb)
531 {
532 	int rc = -ENOBUFS;
533 	struct llc_sock *llc = llc_sk(sk);
534 	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev);
535 
536 	if (nskb) {
537 		struct llc_sap *sap = llc->sap;
538 
539 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
540 				    llc->daddr.lsap, LLC_PDU_CMD);
541 		llc_pdu_init_as_rnr_cmd(nskb, 1, llc->vR);
542 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
543 		if (unlikely(rc))
544 			goto free;
545 		llc_conn_send_pdu(sk, nskb);
546 	}
547 out:
548 	return rc;
549 free:
550 	kfree_skb(nskb);
551 	goto out;
552 }
553 
554 int llc_conn_ac_send_rnr_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
555 {
556 	int rc = -ENOBUFS;
557 	struct llc_sock *llc = llc_sk(sk);
558 	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev);
559 
560 	if (nskb) {
561 		struct llc_sap *sap = llc->sap;
562 
563 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
564 				    llc->daddr.lsap, LLC_PDU_RSP);
565 		llc_pdu_init_as_rnr_rsp(nskb, 1, llc->vR);
566 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
567 		if (unlikely(rc))
568 			goto free;
569 		llc_conn_send_pdu(sk, nskb);
570 	}
571 out:
572 	return rc;
573 free:
574 	kfree_skb(nskb);
575 	goto out;
576 }
577 
578 int llc_conn_ac_send_rnr_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
579 {
580 	int rc = -ENOBUFS;
581 	struct llc_sock *llc = llc_sk(sk);
582 	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev);
583 
584 	if (nskb) {
585 		struct llc_sap *sap = llc->sap;
586 
587 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
588 				    llc->daddr.lsap, LLC_PDU_RSP);
589 		llc_pdu_init_as_rnr_rsp(nskb, 0, llc->vR);
590 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
591 		if (unlikely(rc))
592 			goto free;
593 		llc_conn_send_pdu(sk, nskb);
594 	}
595 out:
596 	return rc;
597 free:
598 	kfree_skb(nskb);
599 	goto out;
600 }
601 
602 int llc_conn_ac_set_remote_busy(struct sock *sk, struct sk_buff *skb)
603 {
604 	struct llc_sock *llc = llc_sk(sk);
605 
606 	if (!llc->remote_busy_flag) {
607 		llc->remote_busy_flag = 1;
608 		mod_timer(&llc->busy_state_timer.timer,
609 			 jiffies + llc->busy_state_timer.expire);
610 	}
611 	return 0;
612 }
613 
614 int llc_conn_ac_opt_send_rnr_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
615 {
616 	int rc = -ENOBUFS;
617 	struct llc_sock *llc = llc_sk(sk);
618 	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev);
619 
620 	if (nskb) {
621 		struct llc_sap *sap = llc->sap;
622 
623 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
624 				    llc->daddr.lsap, LLC_PDU_RSP);
625 		llc_pdu_init_as_rnr_rsp(nskb, 0, llc->vR);
626 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
627 		if (unlikely(rc))
628 			goto free;
629 		llc_conn_send_pdu(sk, nskb);
630 	}
631 out:
632 	return rc;
633 free:
634 	kfree_skb(nskb);
635 	goto out;
636 }
637 
638 int llc_conn_ac_send_rr_cmd_p_set_1(struct sock *sk, struct sk_buff *skb)
639 {
640 	int rc = -ENOBUFS;
641 	struct llc_sock *llc = llc_sk(sk);
642 	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev);
643 
644 	if (nskb) {
645 		struct llc_sap *sap = llc->sap;
646 
647 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
648 				    llc->daddr.lsap, LLC_PDU_CMD);
649 		llc_pdu_init_as_rr_cmd(nskb, 1, llc->vR);
650 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
651 		if (unlikely(rc))
652 			goto free;
653 		llc_conn_send_pdu(sk, nskb);
654 	}
655 out:
656 	return rc;
657 free:
658 	kfree_skb(nskb);
659 	goto out;
660 }
661 
662 int llc_conn_ac_send_rr_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
663 {
664 	int rc = -ENOBUFS;
665 	struct llc_sock *llc = llc_sk(sk);
666 	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev);
667 
668 	if (nskb) {
669 		struct llc_sap *sap = llc->sap;
670 		u8 f_bit = 1;
671 
672 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
673 				    llc->daddr.lsap, LLC_PDU_RSP);
674 		llc_pdu_init_as_rr_rsp(nskb, f_bit, llc->vR);
675 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
676 		if (unlikely(rc))
677 			goto free;
678 		llc_conn_send_pdu(sk, nskb);
679 	}
680 out:
681 	return rc;
682 free:
683 	kfree_skb(nskb);
684 	goto out;
685 }
686 
687 int llc_conn_ac_send_ack_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
688 {
689 	int rc = -ENOBUFS;
690 	struct llc_sock *llc = llc_sk(sk);
691 	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev);
692 
693 	if (nskb) {
694 		struct llc_sap *sap = llc->sap;
695 
696 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
697 				    llc->daddr.lsap, LLC_PDU_RSP);
698 		llc_pdu_init_as_rr_rsp(nskb, 1, llc->vR);
699 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
700 		if (unlikely(rc))
701 			goto free;
702 		llc_conn_send_pdu(sk, nskb);
703 	}
704 out:
705 	return rc;
706 free:
707 	kfree_skb(nskb);
708 	goto out;
709 }
710 
711 int llc_conn_ac_send_rr_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
712 {
713 	int rc = -ENOBUFS;
714 	struct llc_sock *llc = llc_sk(sk);
715 	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev);
716 
717 	if (nskb) {
718 		struct llc_sap *sap = llc->sap;
719 
720 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
721 				    llc->daddr.lsap, LLC_PDU_RSP);
722 		llc_pdu_init_as_rr_rsp(nskb, 0, llc->vR);
723 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
724 		if (unlikely(rc))
725 			goto free;
726 		llc_conn_send_pdu(sk, nskb);
727 	}
728 out:
729 	return rc;
730 free:
731 	kfree_skb(nskb);
732 	goto out;
733 }
734 
735 int llc_conn_ac_send_ack_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
736 {
737 	int rc = -ENOBUFS;
738 	struct llc_sock *llc = llc_sk(sk);
739 	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev);
740 
741 	if (nskb) {
742 		struct llc_sap *sap = llc->sap;
743 
744 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
745 				    llc->daddr.lsap, LLC_PDU_RSP);
746 		llc_pdu_init_as_rr_rsp(nskb, 0, llc->vR);
747 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
748 		if (unlikely(rc))
749 			goto free;
750 		llc_conn_send_pdu(sk, nskb);
751 	}
752 out:
753 	return rc;
754 free:
755 	kfree_skb(nskb);
756 	goto out;
757 }
758 
759 void llc_conn_set_p_flag(struct sock *sk, u8 value)
760 {
761 	int state_changed = llc_sk(sk)->p_flag && !value;
762 
763 	llc_sk(sk)->p_flag = value;
764 
765 	if (state_changed)
766 		sk->sk_state_change(sk);
767 }
768 
769 int llc_conn_ac_send_sabme_cmd_p_set_x(struct sock *sk, struct sk_buff *skb)
770 {
771 	int rc = -ENOBUFS;
772 	struct llc_sock *llc = llc_sk(sk);
773 	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev);
774 
775 	if (nskb) {
776 		struct llc_sap *sap = llc->sap;
777 		u8 *dmac = llc->daddr.mac;
778 
779 		if (llc->dev->flags & IFF_LOOPBACK)
780 			dmac = llc->dev->dev_addr;
781 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
782 				    llc->daddr.lsap, LLC_PDU_CMD);
783 		llc_pdu_init_as_sabme_cmd(nskb, 1);
784 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, dmac);
785 		if (unlikely(rc))
786 			goto free;
787 		llc_conn_send_pdu(sk, nskb);
788 		llc_conn_set_p_flag(sk, 1);
789 	}
790 out:
791 	return rc;
792 free:
793 	kfree_skb(nskb);
794 	goto out;
795 }
796 
797 int llc_conn_ac_send_ua_rsp_f_set_p(struct sock *sk, struct sk_buff *skb)
798 {
799 	u8 f_bit;
800 	int rc = -ENOBUFS;
801 	struct llc_sock *llc = llc_sk(sk);
802 	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev);
803 
804 	llc_pdu_decode_pf_bit(skb, &f_bit);
805 	if (nskb) {
806 		struct llc_sap *sap = llc->sap;
807 
808 		nskb->dev = llc->dev;
809 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
810 				    llc->daddr.lsap, LLC_PDU_RSP);
811 		llc_pdu_init_as_ua_rsp(nskb, f_bit);
812 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
813 		if (unlikely(rc))
814 			goto free;
815 		llc_conn_send_pdu(sk, nskb);
816 	}
817 out:
818 	return rc;
819 free:
820 	kfree_skb(nskb);
821 	goto out;
822 }
823 
824 int llc_conn_ac_set_s_flag_0(struct sock *sk, struct sk_buff *skb)
825 {
826 	llc_sk(sk)->s_flag = 0;
827 	return 0;
828 }
829 
830 int llc_conn_ac_set_s_flag_1(struct sock *sk, struct sk_buff *skb)
831 {
832 	llc_sk(sk)->s_flag = 1;
833 	return 0;
834 }
835 
836 int llc_conn_ac_start_p_timer(struct sock *sk, struct sk_buff *skb)
837 {
838 	struct llc_sock *llc = llc_sk(sk);
839 
840 	llc_conn_set_p_flag(sk, 1);
841 	mod_timer(&llc->pf_cycle_timer.timer,
842 		  jiffies + llc->pf_cycle_timer.expire);
843 	return 0;
844 }
845 
846 /**
847  *	llc_conn_ac_send_ack_if_needed - check if ack is needed
848  *	@sk: current connection structure
849  *	@skb: current event
850  *
851  *	Checks number of received PDUs which have not been acknowledged, yet,
852  *	If number of them reaches to "npta"(Number of PDUs To Acknowledge) then
853  *	sends an RR response as acknowledgement for them.  Returns 0 for
854  *	success, 1 otherwise.
855  */
856 int llc_conn_ac_send_ack_if_needed(struct sock *sk, struct sk_buff *skb)
857 {
858 	u8 pf_bit;
859 	struct llc_sock *llc = llc_sk(sk);
860 
861 	llc_pdu_decode_pf_bit(skb, &pf_bit);
862 	llc->ack_pf |= pf_bit & 1;
863 	if (!llc->ack_must_be_send) {
864 		llc->first_pdu_Ns = llc->vR;
865 		llc->ack_must_be_send = 1;
866 		llc->ack_pf = pf_bit & 1;
867 	}
868 	if (((llc->vR - llc->first_pdu_Ns + 1 + LLC_2_SEQ_NBR_MODULO)
869 			% LLC_2_SEQ_NBR_MODULO) >= llc->npta) {
870 		llc_conn_ac_send_rr_rsp_f_set_ackpf(sk, skb);
871 		llc->ack_must_be_send	= 0;
872 		llc->ack_pf		= 0;
873 		llc_conn_ac_inc_npta_value(sk, skb);
874 	}
875 	return 0;
876 }
877 
878 /**
879  *	llc_conn_ac_rst_sendack_flag - resets ack_must_be_send flag
880  *	@sk: current connection structure
881  *	@skb: current event
882  *
883  *	This action resets ack_must_be_send flag of given connection, this flag
884  *	indicates if there is any PDU which has not been acknowledged yet.
885  *	Returns 0 for success, 1 otherwise.
886  */
887 int llc_conn_ac_rst_sendack_flag(struct sock *sk, struct sk_buff *skb)
888 {
889 	llc_sk(sk)->ack_must_be_send = llc_sk(sk)->ack_pf = 0;
890 	return 0;
891 }
892 
893 /**
894  *	llc_conn_ac_send_i_rsp_f_set_ackpf - acknowledge received PDUs
895  *	@sk: current connection structure
896  *	@skb: current event
897  *
898  *	Sends an I response PDU with f-bit set to ack_pf flag as acknowledge to
899  *	all received PDUs which have not been acknowledged, yet. ack_pf flag is
900  *	set to one if one PDU with p-bit set to one is received.  Returns 0 for
901  *	success, 1 otherwise.
902  */
903 static int llc_conn_ac_send_i_rsp_f_set_ackpf(struct sock *sk,
904 					      struct sk_buff *skb)
905 {
906 	int rc;
907 	struct llc_sock *llc = llc_sk(sk);
908 	struct llc_sap *sap = llc->sap;
909 
910 	llc_pdu_header_init(skb, LLC_PDU_TYPE_I, sap->laddr.lsap,
911 			    llc->daddr.lsap, LLC_PDU_RSP);
912 	llc_pdu_init_as_i_cmd(skb, llc->ack_pf, llc->vS, llc->vR);
913 	rc = llc_mac_hdr_init(skb, llc->dev->dev_addr, llc->daddr.mac);
914 	if (likely(!rc)) {
915 		llc_conn_send_pdu(sk, skb);
916 		llc_conn_ac_inc_vs_by_1(sk, skb);
917 	}
918 	return rc;
919 }
920 
921 /**
922  *	llc_conn_ac_send_i_as_ack - sends an I-format PDU to acknowledge rx PDUs
923  *	@sk: current connection structure.
924  *	@skb: current event.
925  *
926  *	This action sends an I-format PDU as acknowledge to received PDUs which
927  *	have not been acknowledged, yet, if there is any. By using of this
928  *	action number of acknowledgements decreases, this technic is called
929  *	piggy backing. Returns 0 for success, 1 otherwise.
930  */
931 int llc_conn_ac_send_i_as_ack(struct sock *sk, struct sk_buff *skb)
932 {
933 	struct llc_sock *llc = llc_sk(sk);
934 
935 	if (llc->ack_must_be_send) {
936 		llc_conn_ac_send_i_rsp_f_set_ackpf(sk, skb);
937 		llc->ack_must_be_send = 0 ;
938 		llc->ack_pf = 0;
939 	} else
940 		llc_conn_ac_send_i_cmd_p_set_0(sk, skb);
941 	return 0;
942 }
943 
944 /**
945  *	llc_conn_ac_send_rr_rsp_f_set_ackpf - ack all rx PDUs not yet acked
946  *	@sk: current connection structure.
947  *	@skb: current event.
948  *
949  *	This action sends an RR response with f-bit set to ack_pf flag as
950  *	acknowledge to all received PDUs which have not been acknowledged, yet,
951  *	if there is any. ack_pf flag indicates if a PDU has been received with
952  *	p-bit set to one. Returns 0 for success, 1 otherwise.
953  */
954 static int llc_conn_ac_send_rr_rsp_f_set_ackpf(struct sock *sk,
955 					       struct sk_buff *skb)
956 {
957 	int rc = -ENOBUFS;
958 	struct llc_sock *llc = llc_sk(sk);
959 	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev);
960 
961 	if (nskb) {
962 		struct llc_sap *sap = llc->sap;
963 
964 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
965 				    llc->daddr.lsap, LLC_PDU_RSP);
966 		llc_pdu_init_as_rr_rsp(nskb, llc->ack_pf, llc->vR);
967 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
968 		if (unlikely(rc))
969 			goto free;
970 		llc_conn_send_pdu(sk, nskb);
971 	}
972 out:
973 	return rc;
974 free:
975 	kfree_skb(nskb);
976 	goto out;
977 }
978 
979 /**
980  *	llc_conn_ac_inc_npta_value - tries to make value of npta greater
981  *	@sk: current connection structure.
982  *	@skb: current event.
983  *
984  *	After "inc_cntr" times calling of this action, "npta" increase by one.
985  *	this action tries to make vale of "npta" greater as possible; number of
986  *	acknowledgements decreases by increasing of "npta". Returns 0 for
987  *	success, 1 otherwise.
988  */
989 static int llc_conn_ac_inc_npta_value(struct sock *sk, struct sk_buff *skb)
990 {
991 	struct llc_sock *llc = llc_sk(sk);
992 
993 	if (!llc->inc_cntr) {
994 		llc->dec_step = 0;
995 		llc->dec_cntr = llc->inc_cntr = 2;
996 		++llc->npta;
997 		if (llc->npta > (u8) ~LLC_2_SEQ_NBR_MODULO)
998 			llc->npta = (u8) ~LLC_2_SEQ_NBR_MODULO;
999 	} else
1000 		--llc->inc_cntr;
1001 	return 0;
1002 }
1003 
1004 /**
1005  *	llc_conn_ac_adjust_npta_by_rr - decreases "npta" by one
1006  *	@sk: current connection structure.
1007  *	@skb: current event.
1008  *
1009  *	After receiving "dec_cntr" times RR command, this action decreases
1010  *	"npta" by one. Returns 0 for success, 1 otherwise.
1011  */
1012 int llc_conn_ac_adjust_npta_by_rr(struct sock *sk, struct sk_buff *skb)
1013 {
1014 	struct llc_sock *llc = llc_sk(sk);
1015 
1016 	if (!llc->connect_step && !llc->remote_busy_flag) {
1017 		if (!llc->dec_step) {
1018 			if (!llc->dec_cntr) {
1019 				llc->inc_cntr = llc->dec_cntr = 2;
1020 				if (llc->npta > 0)
1021 					llc->npta = llc->npta - 1;
1022 			} else
1023 				llc->dec_cntr -=1;
1024 		}
1025 	} else
1026 		llc->connect_step = 0 ;
1027 	return 0;
1028 }
1029 
1030 /**
1031  *	llc_conn_ac_adjust_npta_by_rnr - decreases "npta" by one
1032  *	@sk: current connection structure.
1033  *	@skb: current event.
1034  *
1035  *	After receiving "dec_cntr" times RNR command, this action decreases
1036  *	"npta" by one. Returns 0 for success, 1 otherwise.
1037  */
1038 int llc_conn_ac_adjust_npta_by_rnr(struct sock *sk, struct sk_buff *skb)
1039 {
1040 	struct llc_sock *llc = llc_sk(sk);
1041 
1042 	if (llc->remote_busy_flag)
1043 		if (!llc->dec_step) {
1044 			if (!llc->dec_cntr) {
1045 				llc->inc_cntr = llc->dec_cntr = 2;
1046 				if (llc->npta > 0)
1047 					--llc->npta;
1048 			} else
1049 				--llc->dec_cntr;
1050 		}
1051 	return 0;
1052 }
1053 
1054 /**
1055  *	llc_conn_ac_dec_tx_win_size - decreases tx window size
1056  *	@sk: current connection structure.
1057  *	@skb: current event.
1058  *
1059  *	After receiving of a REJ command or response, transmit window size is
1060  *	decreased by number of PDUs which are outstanding yet. Returns 0 for
1061  *	success, 1 otherwise.
1062  */
1063 int llc_conn_ac_dec_tx_win_size(struct sock *sk, struct sk_buff *skb)
1064 {
1065 	struct llc_sock *llc = llc_sk(sk);
1066 	u8 unacked_pdu = skb_queue_len(&llc->pdu_unack_q);
1067 
1068 	if (llc->k - unacked_pdu < 1)
1069 		llc->k = 1;
1070 	else
1071 		llc->k -= unacked_pdu;
1072 	return 0;
1073 }
1074 
1075 /**
1076  *	llc_conn_ac_inc_tx_win_size - tx window size is inc by 1
1077  *	@sk: current connection structure.
1078  *	@skb: current event.
1079  *
1080  *	After receiving an RR response with f-bit set to one, transmit window
1081  *	size is increased by one. Returns 0 for success, 1 otherwise.
1082  */
1083 int llc_conn_ac_inc_tx_win_size(struct sock *sk, struct sk_buff *skb)
1084 {
1085 	struct llc_sock *llc = llc_sk(sk);
1086 
1087 	llc->k += 1;
1088 	if (llc->k > (u8) ~LLC_2_SEQ_NBR_MODULO)
1089 		llc->k = (u8) ~LLC_2_SEQ_NBR_MODULO;
1090 	return 0;
1091 }
1092 
1093 int llc_conn_ac_stop_all_timers(struct sock *sk, struct sk_buff *skb)
1094 {
1095 	struct llc_sock *llc = llc_sk(sk);
1096 
1097 	del_timer(&llc->pf_cycle_timer.timer);
1098 	del_timer(&llc->ack_timer.timer);
1099 	del_timer(&llc->rej_sent_timer.timer);
1100 	del_timer(&llc->busy_state_timer.timer);
1101 	llc->ack_must_be_send = 0;
1102 	llc->ack_pf = 0;
1103 	return 0;
1104 }
1105 
1106 int llc_conn_ac_stop_other_timers(struct sock *sk, struct sk_buff *skb)
1107 {
1108 	struct llc_sock *llc = llc_sk(sk);
1109 
1110 	del_timer(&llc->rej_sent_timer.timer);
1111 	del_timer(&llc->pf_cycle_timer.timer);
1112 	del_timer(&llc->busy_state_timer.timer);
1113 	llc->ack_must_be_send = 0;
1114 	llc->ack_pf = 0;
1115 	return 0;
1116 }
1117 
1118 int llc_conn_ac_start_ack_timer(struct sock *sk, struct sk_buff *skb)
1119 {
1120 	struct llc_sock *llc = llc_sk(sk);
1121 
1122 	mod_timer(&llc->ack_timer.timer, jiffies + llc->ack_timer.expire);
1123 	return 0;
1124 }
1125 
1126 int llc_conn_ac_start_rej_timer(struct sock *sk, struct sk_buff *skb)
1127 {
1128 	struct llc_sock *llc = llc_sk(sk);
1129 
1130 	mod_timer(&llc->rej_sent_timer.timer,
1131 		  jiffies + llc->rej_sent_timer.expire);
1132 	return 0;
1133 }
1134 
1135 int llc_conn_ac_start_ack_tmr_if_not_running(struct sock *sk,
1136 					     struct sk_buff *skb)
1137 {
1138 	struct llc_sock *llc = llc_sk(sk);
1139 
1140 	if (!timer_pending(&llc->ack_timer.timer))
1141 		mod_timer(&llc->ack_timer.timer,
1142 			  jiffies + llc->ack_timer.expire);
1143 	return 0;
1144 }
1145 
1146 int llc_conn_ac_stop_ack_timer(struct sock *sk, struct sk_buff *skb)
1147 {
1148 	del_timer(&llc_sk(sk)->ack_timer.timer);
1149 	return 0;
1150 }
1151 
1152 int llc_conn_ac_stop_p_timer(struct sock *sk, struct sk_buff *skb)
1153 {
1154 	struct llc_sock *llc = llc_sk(sk);
1155 
1156 	del_timer(&llc->pf_cycle_timer.timer);
1157 	llc_conn_set_p_flag(sk, 0);
1158 	return 0;
1159 }
1160 
1161 int llc_conn_ac_stop_rej_timer(struct sock *sk, struct sk_buff *skb)
1162 {
1163 	del_timer(&llc_sk(sk)->rej_sent_timer.timer);
1164 	return 0;
1165 }
1166 
1167 int llc_conn_ac_upd_nr_received(struct sock *sk, struct sk_buff *skb)
1168 {
1169 	int acked;
1170 	u16 unacked = 0;
1171 	struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
1172 	struct llc_sock *llc = llc_sk(sk);
1173 
1174 	llc->last_nr = PDU_SUPV_GET_Nr(pdu);
1175 	acked = llc_conn_remove_acked_pdus(sk, llc->last_nr, &unacked);
1176 	/* On loopback we don't queue I frames in unack_pdu_q queue. */
1177 	if (acked > 0 || (llc->dev->flags & IFF_LOOPBACK)) {
1178 		llc->retry_count = 0;
1179 		del_timer(&llc->ack_timer.timer);
1180 		if (llc->failed_data_req) {
1181 			/* already, we did not accept data from upper layer
1182 			 * (tx_window full or unacceptable state). Now, we
1183 			 * can send data and must inform to upper layer.
1184 			 */
1185 			llc->failed_data_req = 0;
1186 			llc_conn_ac_data_confirm(sk, skb);
1187 		}
1188 		if (unacked)
1189 			mod_timer(&llc->ack_timer.timer,
1190 				  jiffies + llc->ack_timer.expire);
1191 	} else if (llc->failed_data_req) {
1192 		u8 f_bit;
1193 
1194 		llc_pdu_decode_pf_bit(skb, &f_bit);
1195 		if (f_bit == 1) {
1196 			llc->failed_data_req = 0;
1197 			llc_conn_ac_data_confirm(sk, skb);
1198 		}
1199 	}
1200 	return 0;
1201 }
1202 
1203 int llc_conn_ac_upd_p_flag(struct sock *sk, struct sk_buff *skb)
1204 {
1205 	struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
1206 
1207 	if (LLC_PDU_IS_RSP(pdu)) {
1208 		u8 f_bit;
1209 
1210 		llc_pdu_decode_pf_bit(skb, &f_bit);
1211 		if (f_bit) {
1212 			llc_conn_set_p_flag(sk, 0);
1213 			llc_conn_ac_stop_p_timer(sk, skb);
1214 		}
1215 	}
1216 	return 0;
1217 }
1218 
1219 int llc_conn_ac_set_data_flag_2(struct sock *sk, struct sk_buff *skb)
1220 {
1221 	llc_sk(sk)->data_flag = 2;
1222 	return 0;
1223 }
1224 
1225 int llc_conn_ac_set_data_flag_0(struct sock *sk, struct sk_buff *skb)
1226 {
1227 	llc_sk(sk)->data_flag = 0;
1228 	return 0;
1229 }
1230 
1231 int llc_conn_ac_set_data_flag_1(struct sock *sk, struct sk_buff *skb)
1232 {
1233 	llc_sk(sk)->data_flag = 1;
1234 	return 0;
1235 }
1236 
1237 int llc_conn_ac_set_data_flag_1_if_data_flag_eq_0(struct sock *sk,
1238 						  struct sk_buff *skb)
1239 {
1240 	if (!llc_sk(sk)->data_flag)
1241 		llc_sk(sk)->data_flag = 1;
1242 	return 0;
1243 }
1244 
1245 int llc_conn_ac_set_p_flag_0(struct sock *sk, struct sk_buff *skb)
1246 {
1247 	llc_conn_set_p_flag(sk, 0);
1248 	return 0;
1249 }
1250 
1251 static int llc_conn_ac_set_p_flag_1(struct sock *sk, struct sk_buff *skb)
1252 {
1253 	llc_conn_set_p_flag(sk, 1);
1254 	return 0;
1255 }
1256 
1257 int llc_conn_ac_set_remote_busy_0(struct sock *sk, struct sk_buff *skb)
1258 {
1259 	llc_sk(sk)->remote_busy_flag = 0;
1260 	return 0;
1261 }
1262 
1263 int llc_conn_ac_set_cause_flag_0(struct sock *sk, struct sk_buff *skb)
1264 {
1265 	llc_sk(sk)->cause_flag = 0;
1266 	return 0;
1267 }
1268 
1269 int llc_conn_ac_set_cause_flag_1(struct sock *sk, struct sk_buff *skb)
1270 {
1271 	llc_sk(sk)->cause_flag = 1;
1272 	return 0;
1273 }
1274 
1275 int llc_conn_ac_set_retry_cnt_0(struct sock *sk, struct sk_buff *skb)
1276 {
1277 	llc_sk(sk)->retry_count = 0;
1278 	return 0;
1279 }
1280 
1281 int llc_conn_ac_inc_retry_cnt_by_1(struct sock *sk, struct sk_buff *skb)
1282 {
1283 	llc_sk(sk)->retry_count++;
1284 	return 0;
1285 }
1286 
1287 int llc_conn_ac_set_vr_0(struct sock *sk, struct sk_buff *skb)
1288 {
1289 	llc_sk(sk)->vR = 0;
1290 	return 0;
1291 }
1292 
1293 int llc_conn_ac_inc_vr_by_1(struct sock *sk, struct sk_buff *skb)
1294 {
1295 	llc_sk(sk)->vR = PDU_GET_NEXT_Vr(llc_sk(sk)->vR);
1296 	return 0;
1297 }
1298 
1299 int llc_conn_ac_set_vs_0(struct sock *sk, struct sk_buff *skb)
1300 {
1301 	llc_sk(sk)->vS = 0;
1302 	return 0;
1303 }
1304 
1305 int llc_conn_ac_set_vs_nr(struct sock *sk, struct sk_buff *skb)
1306 {
1307 	llc_sk(sk)->vS = llc_sk(sk)->last_nr;
1308 	return 0;
1309 }
1310 
1311 static int llc_conn_ac_inc_vs_by_1(struct sock *sk, struct sk_buff *skb)
1312 {
1313 	llc_sk(sk)->vS = (llc_sk(sk)->vS + 1) % LLC_2_SEQ_NBR_MODULO;
1314 	return 0;
1315 }
1316 
1317 static void llc_conn_tmr_common_cb(unsigned long timeout_data, u8 type)
1318 {
1319 	struct sock *sk = (struct sock *)timeout_data;
1320 	struct sk_buff *skb = alloc_skb(0, GFP_ATOMIC);
1321 
1322 	bh_lock_sock(sk);
1323 	if (skb) {
1324 		struct llc_conn_state_ev *ev = llc_conn_ev(skb);
1325 
1326 		skb_set_owner_r(skb, sk);
1327 		ev->type = type;
1328 		llc_process_tmr_ev(sk, skb);
1329 	}
1330 	bh_unlock_sock(sk);
1331 }
1332 
1333 void llc_conn_pf_cycle_tmr_cb(unsigned long timeout_data)
1334 {
1335 	llc_conn_tmr_common_cb(timeout_data, LLC_CONN_EV_TYPE_P_TMR);
1336 }
1337 
1338 void llc_conn_busy_tmr_cb(unsigned long timeout_data)
1339 {
1340 	llc_conn_tmr_common_cb(timeout_data, LLC_CONN_EV_TYPE_BUSY_TMR);
1341 }
1342 
1343 void llc_conn_ack_tmr_cb(unsigned long timeout_data)
1344 {
1345 	llc_conn_tmr_common_cb(timeout_data, LLC_CONN_EV_TYPE_ACK_TMR);
1346 }
1347 
1348 void llc_conn_rej_tmr_cb(unsigned long timeout_data)
1349 {
1350 	llc_conn_tmr_common_cb(timeout_data, LLC_CONN_EV_TYPE_REJ_TMR);
1351 }
1352 
1353 int llc_conn_ac_rst_vs(struct sock *sk, struct sk_buff *skb)
1354 {
1355 	llc_sk(sk)->X = llc_sk(sk)->vS;
1356 	llc_conn_ac_set_vs_nr(sk, skb);
1357 	return 0;
1358 }
1359 
1360 int llc_conn_ac_upd_vs(struct sock *sk, struct sk_buff *skb)
1361 {
1362 	struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
1363 	u8 nr = PDU_SUPV_GET_Nr(pdu);
1364 
1365 	if (llc_circular_between(llc_sk(sk)->vS, nr, llc_sk(sk)->X))
1366 		llc_conn_ac_set_vs_nr(sk, skb);
1367 	return 0;
1368 }
1369 
1370 /*
1371  * Non-standard actions; these not contained in IEEE specification; for
1372  * our own usage
1373  */
1374 /**
1375  *	llc_conn_disc - removes connection from SAP list and frees it
1376  *	@sk: closed connection
1377  *	@skb: occurred event
1378  */
1379 int llc_conn_disc(struct sock *sk, struct sk_buff *skb)
1380 {
1381 	/* FIXME: this thing seems to want to die */
1382 	return 0;
1383 }
1384 
1385 /**
1386  *	llc_conn_reset - resets connection
1387  *	@sk : reseting connection.
1388  *	@skb: occurred event.
1389  *
1390  *	Stop all timers, empty all queues and reset all flags.
1391  */
1392 int llc_conn_reset(struct sock *sk, struct sk_buff *skb)
1393 {
1394 	llc_sk_reset(sk);
1395 	return 0;
1396 }
1397 
1398 /**
1399  *	llc_circular_between - designates that b is between a and c or not
1400  *	@a: lower bound
1401  *	@b: element to see if is between a and b
1402  *	@c: upper bound
1403  *
1404  *	This function designates that b is between a and c or not (for example,
1405  *	0 is between 127 and 1). Returns 1 if b is between a and c, 0
1406  *	otherwise.
1407  */
1408 u8 llc_circular_between(u8 a, u8 b, u8 c)
1409 {
1410 	b = b - a;
1411 	c = c - a;
1412 	return b <= c;
1413 }
1414 
1415 /**
1416  *	llc_process_tmr_ev - timer backend
1417  *	@sk: active connection
1418  *	@skb: occurred event
1419  *
1420  *	This function is called from timer callback functions. When connection
1421  *	is busy (during sending a data frame) timer expiration event must be
1422  *	queued. Otherwise this event can be sent to connection state machine.
1423  *	Queued events will process by llc_backlog_rcv function after sending
1424  *	data frame.
1425  */
1426 static void llc_process_tmr_ev(struct sock *sk, struct sk_buff *skb)
1427 {
1428 	if (llc_sk(sk)->state == LLC_CONN_OUT_OF_SVC) {
1429 		printk(KERN_WARNING "%s: timer called on closed connection\n",
1430 		       __FUNCTION__);
1431 		kfree_skb(skb);
1432 	} else {
1433 		if (!sock_owned_by_user(sk))
1434 			llc_conn_state_process(sk, skb);
1435 		else {
1436 			llc_set_backlog_type(skb, LLC_EVENT);
1437 			sk_add_backlog(sk, skb);
1438 		}
1439 	}
1440 }
1441