xref: /openbmc/linux/net/llc/llc_c_ac.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
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 #include "llc_output.h"
31 
32 static int llc_conn_ac_inc_vs_by_1(struct sock *sk, struct sk_buff *skb);
33 static void llc_process_tmr_ev(struct sock *sk, struct sk_buff *skb);
34 static int llc_conn_ac_data_confirm(struct sock *sk, struct sk_buff *ev);
35 
36 static int llc_conn_ac_inc_npta_value(struct sock *sk, struct sk_buff *skb);
37 
38 static int llc_conn_ac_send_rr_rsp_f_set_ackpf(struct sock *sk,
39 					       struct sk_buff *skb);
40 
41 static int llc_conn_ac_set_p_flag_1(struct sock *sk, struct sk_buff *skb);
42 
43 #define INCORRECT 0
44 
45 int llc_conn_ac_clear_remote_busy(struct sock *sk, struct sk_buff *skb)
46 {
47 	struct llc_sock *llc = llc_sk(sk);
48 
49 	if (llc->remote_busy_flag) {
50 		u8 nr;
51 		struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
52 
53 		llc->remote_busy_flag = 0;
54 		del_timer(&llc->busy_state_timer.timer);
55 		nr = LLC_I_GET_NR(pdu);
56 		llc_conn_resend_i_pdu_as_cmd(sk, nr, 0);
57 	}
58 	return 0;
59 }
60 
61 int llc_conn_ac_conn_ind(struct sock *sk, struct sk_buff *skb)
62 {
63 	int rc = -ENOTCONN;
64 	u8 dsap;
65 	struct llc_sap *sap;
66 
67 	llc_pdu_decode_dsap(skb, &dsap);
68 	sap = llc_sap_find(dsap);
69 	if (sap) {
70 		struct llc_conn_state_ev *ev = llc_conn_ev(skb);
71 		struct llc_sock *llc = llc_sk(sk);
72 
73 		llc_pdu_decode_sa(skb, llc->daddr.mac);
74 		llc_pdu_decode_da(skb, llc->laddr.mac);
75 		llc->dev = skb->dev;
76 		ev->ind_prim = LLC_CONN_PRIM;
77 		rc = 0;
78 	}
79 	return rc;
80 }
81 
82 int llc_conn_ac_conn_confirm(struct sock *sk, struct sk_buff *skb)
83 {
84 	struct llc_conn_state_ev *ev = llc_conn_ev(skb);
85 
86 	ev->cfm_prim = LLC_CONN_PRIM;
87 	return 0;
88 }
89 
90 static int llc_conn_ac_data_confirm(struct sock *sk, struct sk_buff *skb)
91 {
92 	struct llc_conn_state_ev *ev = llc_conn_ev(skb);
93 
94 	ev->cfm_prim = LLC_DATA_PRIM;
95 	return 0;
96 }
97 
98 int llc_conn_ac_data_ind(struct sock *sk, struct sk_buff *skb)
99 {
100 	llc_conn_rtn_pdu(sk, skb);
101 	return 0;
102 }
103 
104 int llc_conn_ac_disc_ind(struct sock *sk, struct sk_buff *skb)
105 {
106 	struct llc_conn_state_ev *ev = llc_conn_ev(skb);
107 	u8 reason = 0;
108 	int rc = 0;
109 
110 	if (ev->type == LLC_CONN_EV_TYPE_PDU) {
111 		struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
112 
113 		if (LLC_PDU_IS_RSP(pdu) &&
114 		    LLC_PDU_TYPE_IS_U(pdu) &&
115 		    LLC_U_PDU_RSP(pdu) == LLC_2_PDU_RSP_DM)
116 			reason = LLC_DISC_REASON_RX_DM_RSP_PDU;
117 		else if (LLC_PDU_IS_CMD(pdu) &&
118 			   LLC_PDU_TYPE_IS_U(pdu) &&
119 			   LLC_U_PDU_CMD(pdu) == LLC_2_PDU_CMD_DISC)
120 			reason = LLC_DISC_REASON_RX_DISC_CMD_PDU;
121 	} else if (ev->type == LLC_CONN_EV_TYPE_ACK_TMR)
122 		reason = LLC_DISC_REASON_ACK_TMR_EXP;
123 	else {
124 		reason = 0;
125 		rc = -EINVAL;
126 	}
127 	if (!rc) {
128 		ev->reason   = reason;
129 		ev->ind_prim = LLC_DISC_PRIM;
130 	}
131 	return rc;
132 }
133 
134 int llc_conn_ac_disc_confirm(struct sock *sk, struct sk_buff *skb)
135 {
136 	struct llc_conn_state_ev *ev = llc_conn_ev(skb);
137 
138 	ev->reason   = ev->status;
139 	ev->cfm_prim = LLC_DISC_PRIM;
140 	return 0;
141 }
142 
143 int llc_conn_ac_rst_ind(struct sock *sk, struct sk_buff *skb)
144 {
145 	u8 reason = 0;
146 	int rc = 1;
147 	struct llc_conn_state_ev *ev = llc_conn_ev(skb);
148 	struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
149 	struct llc_sock *llc = llc_sk(sk);
150 
151 	switch (ev->type) {
152 	case LLC_CONN_EV_TYPE_PDU:
153 		if (LLC_PDU_IS_RSP(pdu) &&
154 		    LLC_PDU_TYPE_IS_U(pdu) &&
155 		    LLC_U_PDU_RSP(pdu) == LLC_2_PDU_RSP_FRMR) {
156 			reason = LLC_RESET_REASON_LOCAL;
157 			rc = 0;
158 		} else if (LLC_PDU_IS_CMD(pdu) &&
159 			   LLC_PDU_TYPE_IS_U(pdu) &&
160 			   LLC_U_PDU_CMD(pdu) == LLC_2_PDU_CMD_SABME) {
161 			reason = LLC_RESET_REASON_REMOTE;
162 			rc = 0;
163 		} else {
164 			reason = 0;
165 			rc  = 1;
166 		}
167 		break;
168 	case LLC_CONN_EV_TYPE_ACK_TMR:
169 	case LLC_CONN_EV_TYPE_P_TMR:
170 	case LLC_CONN_EV_TYPE_REJ_TMR:
171 	case LLC_CONN_EV_TYPE_BUSY_TMR:
172 		if (llc->retry_count > llc->n2) {
173 			reason = LLC_RESET_REASON_LOCAL;
174 			rc = 0;
175 		} else
176 			rc = 1;
177 		break;
178 	}
179 	if (!rc) {
180 		ev->reason   = reason;
181 		ev->ind_prim = LLC_RESET_PRIM;
182 	}
183 	return rc;
184 }
185 
186 int llc_conn_ac_rst_confirm(struct sock *sk, struct sk_buff *skb)
187 {
188 	struct llc_conn_state_ev *ev = llc_conn_ev(skb);
189 
190 	ev->reason   = 0;
191 	ev->cfm_prim = LLC_RESET_PRIM;
192 	return 0;
193 }
194 
195 int llc_conn_ac_clear_remote_busy_if_f_eq_1(struct sock *sk,
196 					    struct sk_buff *skb)
197 {
198 	struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
199 
200 	if (LLC_PDU_IS_RSP(pdu) &&
201 	    LLC_PDU_TYPE_IS_I(pdu) &&
202 	    LLC_I_PF_IS_1(pdu) && llc_sk(sk)->ack_pf)
203 		llc_conn_ac_clear_remote_busy(sk, skb);
204 	return 0;
205 }
206 
207 int llc_conn_ac_stop_rej_tmr_if_data_flag_eq_2(struct sock *sk,
208 					       struct sk_buff *skb)
209 {
210 	struct llc_sock *llc = llc_sk(sk);
211 
212 	if (llc->data_flag == 2)
213 		del_timer(&llc->rej_sent_timer.timer);
214 	return 0;
215 }
216 
217 int llc_conn_ac_send_disc_cmd_p_set_x(struct sock *sk, struct sk_buff *skb)
218 {
219 	int rc = -ENOBUFS;
220 	struct sk_buff *nskb = llc_alloc_frame();
221 
222 	if (nskb) {
223 		struct llc_sock *llc = llc_sk(sk);
224 		struct llc_sap *sap = llc->sap;
225 
226 		nskb->dev = llc->dev;
227 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
228 				    llc->daddr.lsap, LLC_PDU_CMD);
229 		llc_pdu_init_as_disc_cmd(nskb, 1);
230 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
231 		if (rc)
232 			goto free;
233 		llc_conn_send_pdu(sk, nskb);
234 		llc_conn_ac_set_p_flag_1(sk, skb);
235 	}
236 out:
237 	return rc;
238 free:
239 	kfree_skb(nskb);
240 	goto out;
241 }
242 
243 int llc_conn_ac_send_dm_rsp_f_set_p(struct sock *sk, struct sk_buff *skb)
244 {
245 	int rc = -ENOBUFS;
246 	struct sk_buff *nskb = llc_alloc_frame();
247 
248 	if (nskb) {
249 		struct llc_sock *llc = llc_sk(sk);
250 		struct llc_sap *sap = llc->sap;
251 		u8 f_bit;
252 
253 		nskb->dev = llc->dev;
254 		llc_pdu_decode_pf_bit(skb, &f_bit);
255 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
256 				    llc->daddr.lsap, LLC_PDU_RSP);
257 		llc_pdu_init_as_dm_rsp(nskb, f_bit);
258 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
259 		if (rc)
260 			goto free;
261 		llc_conn_send_pdu(sk, nskb);
262 	}
263 out:
264 	return rc;
265 free:
266 	kfree_skb(nskb);
267 	goto out;
268 }
269 
270 int llc_conn_ac_send_dm_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
271 {
272 	int rc = -ENOBUFS;
273 	struct sk_buff *nskb = llc_alloc_frame();
274 
275 	if (nskb) {
276 		struct llc_sock *llc = llc_sk(sk);
277 		struct llc_sap *sap = llc->sap;
278 		u8 f_bit = 1;
279 
280 		nskb->dev = llc->dev;
281 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
282 				    llc->daddr.lsap, LLC_PDU_RSP);
283 		llc_pdu_init_as_dm_rsp(nskb, f_bit);
284 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
285 		if (rc)
286 			goto free;
287 		llc_conn_send_pdu(sk, nskb);
288 	}
289 out:
290 	return rc;
291 free:
292 	kfree_skb(nskb);
293 	goto out;
294 }
295 
296 int llc_conn_ac_send_frmr_rsp_f_set_x(struct sock *sk, struct sk_buff *skb)
297 {
298 	u8 f_bit;
299 	int rc = -ENOBUFS;
300 	struct sk_buff *nskb;
301 	struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
302 	struct llc_sock *llc = llc_sk(sk);
303 
304 	llc->rx_pdu_hdr = *((u32 *)pdu);
305 	if (LLC_PDU_IS_CMD(pdu))
306 		llc_pdu_decode_pf_bit(skb, &f_bit);
307 	else
308 		f_bit = 0;
309 	nskb = llc_alloc_frame();
310 	if (nskb) {
311 		struct llc_sap *sap = llc->sap;
312 
313 		nskb->dev = llc->dev;
314 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
315 				    llc->daddr.lsap, LLC_PDU_RSP);
316 		llc_pdu_init_as_frmr_rsp(nskb, pdu, f_bit, llc->vS,
317 					 llc->vR, INCORRECT);
318 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
319 		if (rc)
320 			goto free;
321 		llc_conn_send_pdu(sk, nskb);
322 	}
323 out:
324 	return rc;
325 free:
326 	kfree_skb(nskb);
327 	goto out;
328 }
329 
330 int llc_conn_ac_resend_frmr_rsp_f_set_0(struct sock *sk, struct sk_buff *skb)
331 {
332 	int rc = -ENOBUFS;
333 	struct sk_buff *nskb = llc_alloc_frame();
334 
335 	if (nskb) {
336 		u8 f_bit = 0;
337 		struct llc_sock *llc = llc_sk(sk);
338 		struct llc_sap *sap = llc->sap;
339 		struct llc_pdu_sn *pdu = (struct llc_pdu_sn *)&llc->rx_pdu_hdr;
340 
341 		nskb->dev = llc->dev;
342 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
343 				    llc->daddr.lsap, LLC_PDU_RSP);
344 		llc_pdu_init_as_frmr_rsp(nskb, pdu, f_bit, llc->vS,
345 					 llc->vR, INCORRECT);
346 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
347 		if (rc)
348 			goto free;
349 		llc_conn_send_pdu(sk, nskb);
350 	}
351 out:
352 	return rc;
353 free:
354 	kfree_skb(nskb);
355 	goto out;
356 }
357 
358 int llc_conn_ac_resend_frmr_rsp_f_set_p(struct sock *sk, struct sk_buff *skb)
359 {
360 	u8 f_bit;
361 	int rc = -ENOBUFS;
362 	struct sk_buff *nskb;
363 
364 	llc_pdu_decode_pf_bit(skb, &f_bit);
365 	nskb = llc_alloc_frame();
366 	if (nskb) {
367 		struct llc_sock *llc = llc_sk(sk);
368 		struct llc_sap *sap = llc->sap;
369 		struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
370 
371 		nskb->dev = llc->dev;
372 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
373 				    llc->daddr.lsap, LLC_PDU_RSP);
374 		llc_pdu_init_as_frmr_rsp(nskb, pdu, f_bit, llc->vS,
375 					 llc->vR, INCORRECT);
376 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
377 		if (rc)
378 			goto free;
379 		llc_conn_send_pdu(sk, nskb);
380 	}
381 out:
382 	return rc;
383 free:
384 	kfree_skb(nskb);
385 	goto out;
386 }
387 
388 int llc_conn_ac_send_i_cmd_p_set_1(struct sock *sk, struct sk_buff *skb)
389 {
390 	int rc;
391 	struct llc_sock *llc = llc_sk(sk);
392 	struct llc_sap *sap = llc->sap;
393 
394 	llc_pdu_header_init(skb, LLC_PDU_TYPE_I, sap->laddr.lsap,
395 			    llc->daddr.lsap, LLC_PDU_CMD);
396 	llc_pdu_init_as_i_cmd(skb, 1, llc->vS, llc->vR);
397 	rc = llc_mac_hdr_init(skb, llc->dev->dev_addr, llc->daddr.mac);
398 	if (!rc) {
399 		llc_conn_send_pdu(sk, skb);
400 		llc_conn_ac_inc_vs_by_1(sk, skb);
401 	}
402 	return rc;
403 }
404 
405 static int llc_conn_ac_send_i_cmd_p_set_0(struct sock *sk, struct sk_buff *skb)
406 {
407 	int rc;
408 	struct llc_sock *llc = llc_sk(sk);
409 	struct llc_sap *sap = llc->sap;
410 
411 	llc_pdu_header_init(skb, LLC_PDU_TYPE_I, sap->laddr.lsap,
412 			    llc->daddr.lsap, LLC_PDU_CMD);
413 	llc_pdu_init_as_i_cmd(skb, 0, llc->vS, llc->vR);
414 	rc = llc_mac_hdr_init(skb, llc->dev->dev_addr, llc->daddr.mac);
415 	if (!rc) {
416 		llc_conn_send_pdu(sk, skb);
417 		llc_conn_ac_inc_vs_by_1(sk, skb);
418 	}
419 	return rc;
420 }
421 
422 int llc_conn_ac_send_i_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
423 {
424 	int rc;
425 	struct llc_sock *llc = llc_sk(sk);
426 	struct llc_sap *sap = llc->sap;
427 
428 	llc_pdu_header_init(skb, LLC_PDU_TYPE_I, sap->laddr.lsap,
429 			    llc->daddr.lsap, LLC_PDU_CMD);
430 	llc_pdu_init_as_i_cmd(skb, 0, llc->vS, llc->vR);
431 	rc = llc_mac_hdr_init(skb, llc->dev->dev_addr, llc->daddr.mac);
432 	if (!rc) {
433 		llc_conn_send_pdu(sk, skb);
434 		llc_conn_ac_inc_vs_by_1(sk, skb);
435 	}
436 	return 0;
437 }
438 
439 int llc_conn_ac_resend_i_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
440 {
441 	struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
442 	u8 nr = LLC_I_GET_NR(pdu);
443 
444 	llc_conn_resend_i_pdu_as_cmd(sk, nr, 0);
445 	return 0;
446 }
447 
448 int llc_conn_ac_resend_i_xxx_x_set_0_or_send_rr(struct sock *sk,
449 						struct sk_buff *skb)
450 {
451 	u8 nr;
452 	struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
453 	int rc = -ENOBUFS;
454 	struct sk_buff *nskb = llc_alloc_frame();
455 
456 	if (nskb) {
457 		struct llc_sock *llc = llc_sk(sk);
458 		struct llc_sap *sap = llc->sap;
459 
460 		nskb->dev = llc->dev;
461 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
462 				    llc->daddr.lsap, LLC_PDU_RSP);
463 		llc_pdu_init_as_rr_rsp(nskb, 0, llc->vR);
464 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
465 		if (!rc)
466 			llc_conn_send_pdu(sk, nskb);
467 		else
468 			kfree_skb(skb);
469 	}
470 	if (rc) {
471 		nr = LLC_I_GET_NR(pdu);
472 		rc = 0;
473 		llc_conn_resend_i_pdu_as_cmd(sk, nr, 0);
474 	}
475 	return rc;
476 }
477 
478 int llc_conn_ac_resend_i_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
479 {
480 	struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
481 	u8 nr = LLC_I_GET_NR(pdu);
482 
483 	llc_conn_resend_i_pdu_as_rsp(sk, nr, 1);
484 	return 0;
485 }
486 
487 int llc_conn_ac_send_rej_cmd_p_set_1(struct sock *sk, struct sk_buff *skb)
488 {
489 	int rc = -ENOBUFS;
490 	struct sk_buff *nskb = llc_alloc_frame();
491 
492 	if (nskb) {
493 		struct llc_sock *llc = llc_sk(sk);
494 		struct llc_sap *sap = llc->sap;
495 
496 		nskb->dev = llc->dev;
497 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
498 				    llc->daddr.lsap, LLC_PDU_CMD);
499 		llc_pdu_init_as_rej_cmd(nskb, 1, llc->vR);
500 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
501 		if (rc)
502 			goto free;
503 		llc_conn_send_pdu(sk, nskb);
504 	}
505 out:
506 	return rc;
507 free:
508 	kfree_skb(nskb);
509 	goto out;
510 }
511 
512 int llc_conn_ac_send_rej_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
513 {
514 	int rc = -ENOBUFS;
515 	struct sk_buff *nskb = llc_alloc_frame();
516 
517 	if (nskb) {
518 		u8 f_bit = 1;
519 		struct llc_sock *llc = llc_sk(sk);
520 		struct llc_sap *sap = llc->sap;
521 
522 		nskb->dev = llc->dev;
523 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
524 				    llc->daddr.lsap, LLC_PDU_RSP);
525 		llc_pdu_init_as_rej_rsp(nskb, f_bit, llc->vR);
526 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
527 		if (rc)
528 			goto free;
529 		llc_conn_send_pdu(sk, nskb);
530 	}
531 out:
532 	return rc;
533 free:
534 	kfree_skb(nskb);
535 	goto out;
536 }
537 
538 int llc_conn_ac_send_rej_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
539 {
540 	int rc = -ENOBUFS;
541 	struct sk_buff *nskb = llc_alloc_frame();
542 
543 	if (nskb) {
544 		struct llc_sock *llc = llc_sk(sk);
545 		struct llc_sap *sap = llc->sap;
546 		u8 f_bit = 0;
547 
548 		nskb->dev = llc->dev;
549 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
550 				    llc->daddr.lsap, LLC_PDU_RSP);
551 		llc_pdu_init_as_rej_rsp(nskb, f_bit, llc->vR);
552 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
553 		if (rc)
554 			goto free;
555 		llc_conn_send_pdu(sk, nskb);
556 	}
557 out:
558 	return rc;
559 free:
560 	kfree_skb(nskb);
561 	goto out;
562 }
563 
564 int llc_conn_ac_send_rnr_cmd_p_set_1(struct sock *sk, struct sk_buff *skb)
565 {
566 	int rc = -ENOBUFS;
567 	struct sk_buff *nskb = llc_alloc_frame();
568 
569 	if (nskb) {
570 		struct llc_sock *llc = llc_sk(sk);
571 		struct llc_sap *sap = llc->sap;
572 
573 		nskb->dev = llc->dev;
574 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
575 				    llc->daddr.lsap, LLC_PDU_CMD);
576 		llc_pdu_init_as_rnr_cmd(nskb, 1, llc->vR);
577 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
578 		if (rc)
579 			goto free;
580 		llc_conn_send_pdu(sk, nskb);
581 	}
582 out:
583 	return rc;
584 free:
585 	kfree_skb(nskb);
586 	goto out;
587 }
588 
589 int llc_conn_ac_send_rnr_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
590 {
591 	int rc = -ENOBUFS;
592 	struct sk_buff *nskb = llc_alloc_frame();
593 
594 	if (nskb) {
595 		struct llc_sock *llc = llc_sk(sk);
596 		struct llc_sap *sap = llc->sap;
597 		u8 f_bit = 1;
598 
599 		nskb->dev = llc->dev;
600 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
601 				    llc->daddr.lsap, LLC_PDU_RSP);
602 		llc_pdu_init_as_rnr_rsp(nskb, f_bit, llc->vR);
603 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
604 		if (rc)
605 			goto free;
606 		llc_conn_send_pdu(sk, nskb);
607 	}
608 out:
609 	return rc;
610 free:
611 	kfree_skb(nskb);
612 	goto out;
613 }
614 
615 int llc_conn_ac_send_rnr_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
616 {
617 	int rc = -ENOBUFS;
618 	struct sk_buff *nskb = llc_alloc_frame();
619 
620 	if (nskb) {
621 		u8 f_bit = 0;
622 		struct llc_sock *llc = llc_sk(sk);
623 		struct llc_sap *sap = llc->sap;
624 
625 		nskb->dev = llc->dev;
626 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
627 				    llc->daddr.lsap, LLC_PDU_RSP);
628 		llc_pdu_init_as_rnr_rsp(nskb, f_bit, llc->vR);
629 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
630 		if (rc)
631 			goto free;
632 		llc_conn_send_pdu(sk, nskb);
633 	}
634 out:
635 	return rc;
636 free:
637 	kfree_skb(nskb);
638 	goto out;
639 }
640 
641 int llc_conn_ac_set_remote_busy(struct sock *sk, struct sk_buff *skb)
642 {
643 	struct llc_sock *llc = llc_sk(sk);
644 
645 	if (!llc->remote_busy_flag) {
646 		llc->remote_busy_flag = 1;
647 		mod_timer(&llc->busy_state_timer.timer,
648 			 jiffies + llc->busy_state_timer.expire * HZ);
649 	}
650 	return 0;
651 }
652 
653 int llc_conn_ac_opt_send_rnr_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
654 {
655 	int rc = -ENOBUFS;
656 	struct sk_buff *nskb = llc_alloc_frame();
657 
658 	if (nskb) {
659 		struct llc_sock *llc = llc_sk(sk);
660 		struct llc_sap *sap = llc->sap;
661 
662 		nskb->dev = llc->dev;
663 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
664 				    llc->daddr.lsap, LLC_PDU_RSP);
665 		llc_pdu_init_as_rnr_rsp(nskb, 0, llc->vR);
666 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
667 		if (rc)
668 			goto free;
669 		llc_conn_send_pdu(sk, nskb);
670 	}
671 out:
672 	return rc;
673 free:
674 	kfree_skb(nskb);
675 	goto out;
676 }
677 
678 int llc_conn_ac_send_rr_cmd_p_set_1(struct sock *sk, struct sk_buff *skb)
679 {
680 	int rc = -ENOBUFS;
681 	struct sk_buff *nskb = llc_alloc_frame();
682 
683 	if (nskb) {
684 		struct llc_sock *llc = llc_sk(sk);
685 		struct llc_sap *sap = llc->sap;
686 
687 		nskb->dev = llc->dev;
688 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
689 				    llc->daddr.lsap, LLC_PDU_CMD);
690 		llc_pdu_init_as_rr_cmd(nskb, 1, llc->vR);
691 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
692 		if (rc)
693 			goto free;
694 		llc_conn_send_pdu(sk, nskb);
695 	}
696 out:
697 	return rc;
698 free:
699 	kfree_skb(nskb);
700 	goto out;
701 }
702 
703 int llc_conn_ac_send_rr_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
704 {
705 	int rc = -ENOBUFS;
706 	struct sk_buff *nskb = llc_alloc_frame();
707 
708 	if (nskb) {
709 		struct llc_sock *llc = llc_sk(sk);
710 		struct llc_sap *sap = llc->sap;
711 		u8 f_bit = 1;
712 
713 		nskb->dev = llc->dev;
714 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
715 				    llc->daddr.lsap, LLC_PDU_RSP);
716 		llc_pdu_init_as_rr_rsp(nskb, f_bit, llc->vR);
717 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
718 		if (rc)
719 			goto free;
720 		llc_conn_send_pdu(sk, nskb);
721 	}
722 out:
723 	return rc;
724 free:
725 	kfree_skb(nskb);
726 	goto out;
727 }
728 
729 int llc_conn_ac_send_ack_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
730 {
731 	int rc = -ENOBUFS;
732 	struct sk_buff *nskb = llc_alloc_frame();
733 
734 	if (nskb) {
735 		struct llc_sock *llc = llc_sk(sk);
736 		struct llc_sap *sap = llc->sap;
737 		u8 f_bit = 1;
738 
739 		nskb->dev = llc->dev;
740 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
741 				    llc->daddr.lsap, LLC_PDU_RSP);
742 		llc_pdu_init_as_rr_rsp(nskb, f_bit, llc->vR);
743 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
744 		if (rc)
745 			goto free;
746 		llc_conn_send_pdu(sk, nskb);
747 	}
748 out:
749 	return rc;
750 free:
751 	kfree_skb(nskb);
752 	goto out;
753 }
754 
755 int llc_conn_ac_send_rr_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
756 {
757 	int rc = -ENOBUFS;
758 	struct sk_buff *nskb = llc_alloc_frame();
759 
760 	if (nskb) {
761 		struct llc_sock *llc = llc_sk(sk);
762 		struct llc_sap *sap = llc->sap;
763 
764 		nskb->dev = llc->dev;
765 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
766 				    llc->daddr.lsap, LLC_PDU_RSP);
767 		llc_pdu_init_as_rr_rsp(nskb, 0, llc->vR);
768 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
769 		if (rc)
770 			goto free;
771 		llc_conn_send_pdu(sk, nskb);
772 	}
773 out:
774 	return rc;
775 free:
776 	kfree_skb(nskb);
777 	goto out;
778 }
779 
780 int llc_conn_ac_send_ack_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
781 {
782 	int rc = -ENOBUFS;
783 	struct sk_buff *nskb = llc_alloc_frame();
784 
785 	if (nskb) {
786 		struct llc_sock *llc = llc_sk(sk);
787 		struct llc_sap *sap = llc->sap;
788 
789 		nskb->dev = llc->dev;
790 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
791 				    llc->daddr.lsap, LLC_PDU_RSP);
792 		llc_pdu_init_as_rr_rsp(nskb, 0, llc->vR);
793 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
794 		if (rc)
795 			goto free;
796 		llc_conn_send_pdu(sk, nskb);
797 	}
798 out:
799 	return rc;
800 free:
801 	kfree_skb(nskb);
802 	goto out;
803 }
804 
805 void llc_conn_set_p_flag(struct sock *sk, u8 value)
806 {
807 	int state_changed = llc_sk(sk)->p_flag && !value;
808 
809 	llc_sk(sk)->p_flag = value;
810 
811 	if (state_changed)
812 		sk->sk_state_change(sk);
813 }
814 
815 int llc_conn_ac_send_sabme_cmd_p_set_x(struct sock *sk, struct sk_buff *skb)
816 {
817 	int rc = -ENOBUFS;
818 	struct sk_buff *nskb = llc_alloc_frame();
819 	struct llc_sock *llc = llc_sk(sk);
820 
821 	if (nskb) {
822 		struct llc_sap *sap = llc->sap;
823 		u8 *dmac = llc->daddr.mac;
824 
825 		if (llc->dev->flags & IFF_LOOPBACK)
826 			dmac = llc->dev->dev_addr;
827 		nskb->dev = llc->dev;
828 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
829 				    llc->daddr.lsap, LLC_PDU_CMD);
830 		llc_pdu_init_as_sabme_cmd(nskb, 1);
831 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, dmac);
832 		if (rc)
833 			goto free;
834 		llc_conn_send_pdu(sk, nskb);
835 		llc_conn_set_p_flag(sk, 1);
836 	}
837 out:
838 	return rc;
839 free:
840 	kfree_skb(nskb);
841 	goto out;
842 }
843 
844 int llc_conn_ac_send_ua_rsp_f_set_p(struct sock *sk, struct sk_buff *skb)
845 {
846 	u8 f_bit;
847 	int rc = -ENOBUFS;
848 	struct sk_buff *nskb = llc_alloc_frame();
849 
850 	llc_pdu_decode_pf_bit(skb, &f_bit);
851 	if (nskb) {
852 		struct llc_sock *llc = llc_sk(sk);
853 		struct llc_sap *sap = llc->sap;
854 
855 		nskb->dev = llc->dev;
856 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
857 				    llc->daddr.lsap, LLC_PDU_RSP);
858 		llc_pdu_init_as_ua_rsp(nskb, f_bit);
859 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
860 		if (rc)
861 			goto free;
862 		llc_conn_send_pdu(sk, nskb);
863 	}
864 out:
865 	return rc;
866 free:
867 	kfree_skb(nskb);
868 	goto out;
869 }
870 
871 int llc_conn_ac_set_s_flag_0(struct sock *sk, struct sk_buff *skb)
872 {
873 	llc_sk(sk)->s_flag = 0;
874 	return 0;
875 }
876 
877 int llc_conn_ac_set_s_flag_1(struct sock *sk, struct sk_buff *skb)
878 {
879 	llc_sk(sk)->s_flag = 1;
880 	return 0;
881 }
882 
883 int llc_conn_ac_start_p_timer(struct sock *sk, struct sk_buff *skb)
884 {
885 	struct llc_sock *llc = llc_sk(sk);
886 
887 	llc_conn_set_p_flag(sk, 1);
888 	mod_timer(&llc->pf_cycle_timer.timer,
889 		  jiffies + llc->pf_cycle_timer.expire * HZ);
890 	return 0;
891 }
892 
893 /**
894  *	llc_conn_ac_send_ack_if_needed - check if ack is needed
895  *	@sk: current connection structure
896  *	@skb: current event
897  *
898  *	Checks number of received PDUs which have not been acknowledged, yet,
899  *	If number of them reaches to "npta"(Number of PDUs To Acknowledge) then
900  *	sends an RR response as acknowledgement for them.  Returns 0 for
901  *	success, 1 otherwise.
902  */
903 int llc_conn_ac_send_ack_if_needed(struct sock *sk, struct sk_buff *skb)
904 {
905 	u8 pf_bit;
906 	struct llc_sock *llc = llc_sk(sk);
907 
908 	llc_pdu_decode_pf_bit(skb, &pf_bit);
909 	llc->ack_pf |= pf_bit & 1;
910 	if (!llc->ack_must_be_send) {
911 		llc->first_pdu_Ns = llc->vR;
912 		llc->ack_must_be_send = 1;
913 		llc->ack_pf = pf_bit & 1;
914 	}
915 	if (((llc->vR - llc->first_pdu_Ns + 129) % 128) >= llc->npta) {
916 		llc_conn_ac_send_rr_rsp_f_set_ackpf(sk, skb);
917 		llc->ack_must_be_send	= 0;
918 		llc->ack_pf		= 0;
919 		llc_conn_ac_inc_npta_value(sk, skb);
920 	}
921 	return 0;
922 }
923 
924 /**
925  *	llc_conn_ac_rst_sendack_flag - resets ack_must_be_send flag
926  *	@sk: current connection structure
927  *	@skb: current event
928  *
929  *	This action resets ack_must_be_send flag of given connection, this flag
930  *	indicates if there is any PDU which has not been acknowledged yet.
931  *	Returns 0 for success, 1 otherwise.
932  */
933 int llc_conn_ac_rst_sendack_flag(struct sock *sk, struct sk_buff *skb)
934 {
935 	llc_sk(sk)->ack_must_be_send = llc_sk(sk)->ack_pf = 0;
936 	return 0;
937 }
938 
939 /**
940  *	llc_conn_ac_send_i_rsp_f_set_ackpf - acknowledge received PDUs
941  *	@sk: current connection structure
942  *	@skb: current event
943  *
944  *	Sends an I response PDU with f-bit set to ack_pf flag as acknowledge to
945  *	all received PDUs which have not been acknowledged, yet. ack_pf flag is
946  *	set to one if one PDU with p-bit set to one is received.  Returns 0 for
947  *	success, 1 otherwise.
948  */
949 static int llc_conn_ac_send_i_rsp_f_set_ackpf(struct sock *sk,
950 					      struct sk_buff *skb)
951 {
952 	int rc;
953 	struct llc_sock *llc = llc_sk(sk);
954 	struct llc_sap *sap = llc->sap;
955 
956 	llc_pdu_header_init(skb, LLC_PDU_TYPE_I, sap->laddr.lsap,
957 			    llc->daddr.lsap, LLC_PDU_RSP);
958 	llc_pdu_init_as_i_cmd(skb, llc->ack_pf, llc->vS, llc->vR);
959 	rc = llc_mac_hdr_init(skb, llc->dev->dev_addr, llc->daddr.mac);
960 	if (!rc) {
961 		llc_conn_send_pdu(sk, skb);
962 		llc_conn_ac_inc_vs_by_1(sk, skb);
963 	}
964 	return rc;
965 }
966 
967 /**
968  *	llc_conn_ac_send_i_as_ack - sends an I-format PDU to acknowledge rx PDUs
969  *	@sk: current connection structure.
970  *	@skb: current event.
971  *
972  *	This action sends an I-format PDU as acknowledge to received PDUs which
973  *	have not been acknowledged, yet, if there is any. By using of this
974  *	action number of acknowledgements decreases, this technic is called
975  *	piggy backing. Returns 0 for success, 1 otherwise.
976  */
977 int llc_conn_ac_send_i_as_ack(struct sock *sk, struct sk_buff *skb)
978 {
979 	struct llc_sock *llc = llc_sk(sk);
980 
981 	if (llc->ack_must_be_send) {
982 		llc_conn_ac_send_i_rsp_f_set_ackpf(sk, skb);
983 		llc->ack_must_be_send = 0 ;
984 		llc->ack_pf = 0;
985 	} else
986 		llc_conn_ac_send_i_cmd_p_set_0(sk, skb);
987 	return 0;
988 }
989 
990 /**
991  *	llc_conn_ac_send_rr_rsp_f_set_ackpf - ack all rx PDUs not yet acked
992  *	@sk: current connection structure.
993  *	@skb: current event.
994  *
995  *	This action sends an RR response with f-bit set to ack_pf flag as
996  *	acknowledge to all received PDUs which have not been acknowledged, yet,
997  *	if there is any. ack_pf flag indicates if a PDU has been received with
998  *	p-bit set to one. Returns 0 for success, 1 otherwise.
999  */
1000 static int llc_conn_ac_send_rr_rsp_f_set_ackpf(struct sock *sk,
1001 					       struct sk_buff *skb)
1002 {
1003 	int rc = -ENOBUFS;
1004 	struct sk_buff *nskb = llc_alloc_frame();
1005 
1006 	if (nskb) {
1007 		struct llc_sock *llc = llc_sk(sk);
1008 		struct llc_sap *sap = llc->sap;
1009 
1010 		nskb->dev = llc->dev;
1011 		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
1012 				    llc->daddr.lsap, LLC_PDU_RSP);
1013 		llc_pdu_init_as_rr_rsp(nskb, llc->ack_pf, llc->vR);
1014 		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
1015 		if (rc)
1016 			goto free;
1017 		llc_conn_send_pdu(sk, nskb);
1018 	}
1019 out:
1020 	return rc;
1021 free:
1022 	kfree_skb(nskb);
1023 	goto out;
1024 }
1025 
1026 /**
1027  *	llc_conn_ac_inc_npta_value - tries to make value of npta greater
1028  *	@sk: current connection structure.
1029  *	@skb: current event.
1030  *
1031  *	After "inc_cntr" times calling of this action, "npta" increase by one.
1032  *	this action tries to make vale of "npta" greater as possible; number of
1033  *	acknowledgements decreases by increasing of "npta". Returns 0 for
1034  *	success, 1 otherwise.
1035  */
1036 static int llc_conn_ac_inc_npta_value(struct sock *sk, struct sk_buff *skb)
1037 {
1038 	struct llc_sock *llc = llc_sk(sk);
1039 
1040 	if (!llc->inc_cntr) {
1041 		llc->dec_step = 0;
1042 		llc->dec_cntr = llc->inc_cntr = 2;
1043 		++llc->npta;
1044 		if (llc->npta > 127)
1045 			llc->npta = 127 ;
1046 	} else
1047 		--llc->inc_cntr;
1048 	return 0;
1049 }
1050 
1051 /**
1052  *	llc_conn_ac_adjust_npta_by_rr - decreases "npta" by one
1053  *	@sk: current connection structure.
1054  *	@skb: current event.
1055  *
1056  *	After receiving "dec_cntr" times RR command, this action decreases
1057  *	"npta" by one. Returns 0 for success, 1 otherwise.
1058  */
1059 int llc_conn_ac_adjust_npta_by_rr(struct sock *sk, struct sk_buff *skb)
1060 {
1061 	struct llc_sock *llc = llc_sk(sk);
1062 
1063 	if (!llc->connect_step && !llc->remote_busy_flag) {
1064 		if (!llc->dec_step) {
1065 			if (!llc->dec_cntr) {
1066 				llc->inc_cntr = llc->dec_cntr = 2;
1067 				if (llc->npta > 0)
1068 					llc->npta = llc->npta - 1;
1069 			} else
1070 				llc->dec_cntr -=1;
1071 		}
1072 	} else
1073 		llc->connect_step = 0 ;
1074 	return 0;
1075 }
1076 
1077 /**
1078  *	llc_conn_ac_adjust_npta_by_rnr - decreases "npta" by one
1079  *	@sk: current connection structure.
1080  *	@skb: current event.
1081  *
1082  *	After receiving "dec_cntr" times RNR command, this action decreases
1083  *	"npta" by one. Returns 0 for success, 1 otherwise.
1084  */
1085 int llc_conn_ac_adjust_npta_by_rnr(struct sock *sk, struct sk_buff *skb)
1086 {
1087 	struct llc_sock *llc = llc_sk(sk);
1088 
1089 	if (llc->remote_busy_flag)
1090 		if (!llc->dec_step) {
1091 			if (!llc->dec_cntr) {
1092 				llc->inc_cntr = llc->dec_cntr = 2;
1093 				if (llc->npta > 0)
1094 					--llc->npta;
1095 			} else
1096 				--llc->dec_cntr;
1097 		}
1098 	return 0;
1099 }
1100 
1101 /**
1102  *	llc_conn_ac_dec_tx_win_size - decreases tx window size
1103  *	@sk: current connection structure.
1104  *	@skb: current event.
1105  *
1106  *	After receiving of a REJ command or response, transmit window size is
1107  *	decreased by number of PDUs which are outstanding yet. Returns 0 for
1108  *	success, 1 otherwise.
1109  */
1110 int llc_conn_ac_dec_tx_win_size(struct sock *sk, struct sk_buff *skb)
1111 {
1112 	struct llc_sock *llc = llc_sk(sk);
1113 	u8 unacked_pdu = skb_queue_len(&llc->pdu_unack_q);
1114 
1115 	llc->k -= unacked_pdu;
1116 	if (llc->k < 2)
1117 		llc->k = 2;
1118 	return 0;
1119 }
1120 
1121 /**
1122  *	llc_conn_ac_inc_tx_win_size - tx window size is inc by 1
1123  *	@sk: current connection structure.
1124  *	@skb: current event.
1125  *
1126  *	After receiving an RR response with f-bit set to one, transmit window
1127  *	size is increased by one. Returns 0 for success, 1 otherwise.
1128  */
1129 int llc_conn_ac_inc_tx_win_size(struct sock *sk, struct sk_buff *skb)
1130 {
1131 	struct llc_sock *llc = llc_sk(sk);
1132 
1133 	llc->k += 1;
1134 	if (llc->k > 128)
1135 		llc->k = 128 ;
1136 	return 0;
1137 }
1138 
1139 int llc_conn_ac_stop_all_timers(struct sock *sk, struct sk_buff *skb)
1140 {
1141 	struct llc_sock *llc = llc_sk(sk);
1142 
1143 	del_timer(&llc->pf_cycle_timer.timer);
1144 	del_timer(&llc->ack_timer.timer);
1145 	del_timer(&llc->rej_sent_timer.timer);
1146 	del_timer(&llc->busy_state_timer.timer);
1147 	llc->ack_must_be_send = 0;
1148 	llc->ack_pf = 0;
1149 	return 0;
1150 }
1151 
1152 int llc_conn_ac_stop_other_timers(struct sock *sk, struct sk_buff *skb)
1153 {
1154 	struct llc_sock *llc = llc_sk(sk);
1155 
1156 	del_timer(&llc->rej_sent_timer.timer);
1157 	del_timer(&llc->pf_cycle_timer.timer);
1158 	del_timer(&llc->busy_state_timer.timer);
1159 	llc->ack_must_be_send = 0;
1160 	llc->ack_pf = 0;
1161 	return 0;
1162 }
1163 
1164 int llc_conn_ac_start_ack_timer(struct sock *sk, struct sk_buff *skb)
1165 {
1166 	struct llc_sock *llc = llc_sk(sk);
1167 
1168 	mod_timer(&llc->ack_timer.timer, jiffies + llc->ack_timer.expire * HZ);
1169 	return 0;
1170 }
1171 
1172 int llc_conn_ac_start_rej_timer(struct sock *sk, struct sk_buff *skb)
1173 {
1174 	struct llc_sock *llc = llc_sk(sk);
1175 
1176 	mod_timer(&llc->rej_sent_timer.timer,
1177 		  jiffies + llc->rej_sent_timer.expire * HZ);
1178 	return 0;
1179 }
1180 
1181 int llc_conn_ac_start_ack_tmr_if_not_running(struct sock *sk,
1182 					     struct sk_buff *skb)
1183 {
1184 	struct llc_sock *llc = llc_sk(sk);
1185 
1186 	if (!timer_pending(&llc->ack_timer.timer))
1187 		mod_timer(&llc->ack_timer.timer,
1188 			  jiffies + llc->ack_timer.expire * HZ);
1189 	return 0;
1190 }
1191 
1192 int llc_conn_ac_stop_ack_timer(struct sock *sk, struct sk_buff *skb)
1193 {
1194 	del_timer(&llc_sk(sk)->ack_timer.timer);
1195 	return 0;
1196 }
1197 
1198 int llc_conn_ac_stop_p_timer(struct sock *sk, struct sk_buff *skb)
1199 {
1200 	struct llc_sock *llc = llc_sk(sk);
1201 
1202 	del_timer(&llc->pf_cycle_timer.timer);
1203 	llc_conn_set_p_flag(sk, 0);
1204 	return 0;
1205 }
1206 
1207 int llc_conn_ac_stop_rej_timer(struct sock *sk, struct sk_buff *skb)
1208 {
1209 	del_timer(&llc_sk(sk)->rej_sent_timer.timer);
1210 	return 0;
1211 }
1212 
1213 int llc_conn_ac_upd_nr_received(struct sock *sk, struct sk_buff *skb)
1214 {
1215 	int acked;
1216 	u16 unacked = 0;
1217 	struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
1218 	struct llc_sock *llc = llc_sk(sk);
1219 
1220 	llc->last_nr = PDU_SUPV_GET_Nr(pdu);
1221 	acked = llc_conn_remove_acked_pdus(sk, llc->last_nr, &unacked);
1222 	/* On loopback we don't queue I frames in unack_pdu_q queue. */
1223 	if (acked > 0 || (llc->dev->flags & IFF_LOOPBACK)) {
1224 		llc->retry_count = 0;
1225 		del_timer(&llc->ack_timer.timer);
1226 		if (llc->failed_data_req) {
1227 			/* already, we did not accept data from upper layer
1228 			 * (tx_window full or unacceptable state). Now, we
1229 			 * can send data and must inform to upper layer.
1230 			 */
1231 			llc->failed_data_req = 0;
1232 			llc_conn_ac_data_confirm(sk, skb);
1233 		}
1234 		if (unacked)
1235 			mod_timer(&llc->ack_timer.timer,
1236 				  jiffies + llc->ack_timer.expire * HZ);
1237 	} else if (llc->failed_data_req) {
1238 		u8 f_bit;
1239 
1240 		llc_pdu_decode_pf_bit(skb, &f_bit);
1241 		if (f_bit == 1) {
1242 			llc->failed_data_req = 0;
1243 			llc_conn_ac_data_confirm(sk, skb);
1244 		}
1245 	}
1246 	return 0;
1247 }
1248 
1249 int llc_conn_ac_upd_p_flag(struct sock *sk, struct sk_buff *skb)
1250 {
1251 	struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
1252 
1253 	if (LLC_PDU_IS_RSP(pdu)) {
1254 		u8 f_bit;
1255 
1256 		llc_pdu_decode_pf_bit(skb, &f_bit);
1257 		if (f_bit) {
1258 			llc_conn_set_p_flag(sk, 0);
1259 			llc_conn_ac_stop_p_timer(sk, skb);
1260 		}
1261 	}
1262 	return 0;
1263 }
1264 
1265 int llc_conn_ac_set_data_flag_2(struct sock *sk, struct sk_buff *skb)
1266 {
1267 	llc_sk(sk)->data_flag = 2;
1268 	return 0;
1269 }
1270 
1271 int llc_conn_ac_set_data_flag_0(struct sock *sk, struct sk_buff *skb)
1272 {
1273 	llc_sk(sk)->data_flag = 0;
1274 	return 0;
1275 }
1276 
1277 int llc_conn_ac_set_data_flag_1(struct sock *sk, struct sk_buff *skb)
1278 {
1279 	llc_sk(sk)->data_flag = 1;
1280 	return 0;
1281 }
1282 
1283 int llc_conn_ac_set_data_flag_1_if_data_flag_eq_0(struct sock *sk,
1284 						  struct sk_buff *skb)
1285 {
1286 	if (!llc_sk(sk)->data_flag)
1287 		llc_sk(sk)->data_flag = 1;
1288 	return 0;
1289 }
1290 
1291 int llc_conn_ac_set_p_flag_0(struct sock *sk, struct sk_buff *skb)
1292 {
1293 	llc_conn_set_p_flag(sk, 0);
1294 	return 0;
1295 }
1296 
1297 static int llc_conn_ac_set_p_flag_1(struct sock *sk, struct sk_buff *skb)
1298 {
1299 	llc_conn_set_p_flag(sk, 1);
1300 	return 0;
1301 }
1302 
1303 int llc_conn_ac_set_remote_busy_0(struct sock *sk, struct sk_buff *skb)
1304 {
1305 	llc_sk(sk)->remote_busy_flag = 0;
1306 	return 0;
1307 }
1308 
1309 int llc_conn_ac_set_cause_flag_0(struct sock *sk, struct sk_buff *skb)
1310 {
1311 	llc_sk(sk)->cause_flag = 0;
1312 	return 0;
1313 }
1314 
1315 int llc_conn_ac_set_cause_flag_1(struct sock *sk, struct sk_buff *skb)
1316 {
1317 	llc_sk(sk)->cause_flag = 1;
1318 	return 0;
1319 }
1320 
1321 int llc_conn_ac_set_retry_cnt_0(struct sock *sk, struct sk_buff *skb)
1322 {
1323 	llc_sk(sk)->retry_count = 0;
1324 	return 0;
1325 }
1326 
1327 int llc_conn_ac_inc_retry_cnt_by_1(struct sock *sk, struct sk_buff *skb)
1328 {
1329 	llc_sk(sk)->retry_count++;
1330 	return 0;
1331 }
1332 
1333 int llc_conn_ac_set_vr_0(struct sock *sk, struct sk_buff *skb)
1334 {
1335 	llc_sk(sk)->vR = 0;
1336 	return 0;
1337 }
1338 
1339 int llc_conn_ac_inc_vr_by_1(struct sock *sk, struct sk_buff *skb)
1340 {
1341 	llc_sk(sk)->vR = PDU_GET_NEXT_Vr(llc_sk(sk)->vR);
1342 	return 0;
1343 }
1344 
1345 int llc_conn_ac_set_vs_0(struct sock *sk, struct sk_buff *skb)
1346 {
1347 	llc_sk(sk)->vS = 0;
1348 	return 0;
1349 }
1350 
1351 int llc_conn_ac_set_vs_nr(struct sock *sk, struct sk_buff *skb)
1352 {
1353 	llc_sk(sk)->vS = llc_sk(sk)->last_nr;
1354 	return 0;
1355 }
1356 
1357 int llc_conn_ac_inc_vs_by_1(struct sock *sk, struct sk_buff *skb)
1358 {
1359 	llc_sk(sk)->vS = (llc_sk(sk)->vS + 1) % 128;
1360 	return 0;
1361 }
1362 
1363 void llc_conn_pf_cycle_tmr_cb(unsigned long timeout_data)
1364 {
1365 	struct sock *sk = (struct sock *)timeout_data;
1366 	struct sk_buff *skb = alloc_skb(0, GFP_ATOMIC);
1367 
1368 	bh_lock_sock(sk);
1369 	if (skb) {
1370 		struct llc_conn_state_ev *ev = llc_conn_ev(skb);
1371 
1372 		skb->sk  = sk;
1373 		ev->type = LLC_CONN_EV_TYPE_P_TMR;
1374 		llc_process_tmr_ev(sk, skb);
1375 	}
1376 	bh_unlock_sock(sk);
1377 }
1378 
1379 void llc_conn_busy_tmr_cb(unsigned long timeout_data)
1380 {
1381 	struct sock *sk = (struct sock *)timeout_data;
1382 	struct sk_buff *skb = alloc_skb(0, GFP_ATOMIC);
1383 
1384 	bh_lock_sock(sk);
1385 	if (skb) {
1386 		struct llc_conn_state_ev *ev = llc_conn_ev(skb);
1387 
1388 		skb->sk  = sk;
1389 		ev->type = LLC_CONN_EV_TYPE_BUSY_TMR;
1390 		llc_process_tmr_ev(sk, skb);
1391 	}
1392 	bh_unlock_sock(sk);
1393 }
1394 
1395 void llc_conn_ack_tmr_cb(unsigned long timeout_data)
1396 {
1397 	struct sock* sk = (struct sock *)timeout_data;
1398 	struct sk_buff *skb = alloc_skb(0, GFP_ATOMIC);
1399 
1400 	bh_lock_sock(sk);
1401 	if (skb) {
1402 		struct llc_conn_state_ev *ev = llc_conn_ev(skb);
1403 
1404 		skb->sk  = sk;
1405 		ev->type = LLC_CONN_EV_TYPE_ACK_TMR;
1406 		llc_process_tmr_ev(sk, skb);
1407 	}
1408 	bh_unlock_sock(sk);
1409 }
1410 
1411 void llc_conn_rej_tmr_cb(unsigned long timeout_data)
1412 {
1413 	struct sock *sk = (struct sock *)timeout_data;
1414 	struct sk_buff *skb = alloc_skb(0, GFP_ATOMIC);
1415 
1416 	bh_lock_sock(sk);
1417 	if (skb) {
1418 		struct llc_conn_state_ev *ev = llc_conn_ev(skb);
1419 
1420 		skb->sk  = sk;
1421 		ev->type = LLC_CONN_EV_TYPE_REJ_TMR;
1422 		llc_process_tmr_ev(sk, skb);
1423 	}
1424 	bh_unlock_sock(sk);
1425 }
1426 
1427 int llc_conn_ac_rst_vs(struct sock *sk, struct sk_buff *skb)
1428 {
1429 	llc_sk(sk)->X = llc_sk(sk)->vS;
1430 	llc_conn_ac_set_vs_nr(sk, skb);
1431 	return 0;
1432 }
1433 
1434 int llc_conn_ac_upd_vs(struct sock *sk, struct sk_buff *skb)
1435 {
1436 	struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
1437 	u8 nr = PDU_SUPV_GET_Nr(pdu);
1438 
1439 	if (llc_circular_between(llc_sk(sk)->vS, nr, llc_sk(sk)->X))
1440 		llc_conn_ac_set_vs_nr(sk, skb);
1441 	return 0;
1442 }
1443 
1444 /*
1445  * Non-standard actions; these not contained in IEEE specification; for
1446  * our own usage
1447  */
1448 /**
1449  *	llc_conn_disc - removes connection from SAP list and frees it
1450  *	@sk: closed connection
1451  *	@skb: occurred event
1452  */
1453 int llc_conn_disc(struct sock *sk, struct sk_buff *skb)
1454 {
1455 	/* FIXME: this thing seems to want to die */
1456 	return 0;
1457 }
1458 
1459 /**
1460  *	llc_conn_reset - resets connection
1461  *	@sk : reseting connection.
1462  *	@skb: occurred event.
1463  *
1464  *	Stop all timers, empty all queues and reset all flags.
1465  */
1466 int llc_conn_reset(struct sock *sk, struct sk_buff *skb)
1467 {
1468 	llc_sk_reset(sk);
1469 	return 0;
1470 }
1471 
1472 /**
1473  *	llc_circular_between - designates that b is between a and c or not
1474  *	@a: lower bound
1475  *	@b: element to see if is between a and b
1476  *	@c: upper bound
1477  *
1478  *	This function designates that b is between a and c or not (for example,
1479  *	0 is between 127 and 1). Returns 1 if b is between a and c, 0
1480  *	otherwise.
1481  */
1482 u8 llc_circular_between(u8 a, u8 b, u8 c)
1483 {
1484 	b = b - a;
1485 	c = c - a;
1486 	return b <= c;
1487 }
1488 
1489 /**
1490  *	llc_process_tmr_ev - timer backend
1491  *	@sk: active connection
1492  *	@skb: occurred event
1493  *
1494  *	This function is called from timer callback functions. When connection
1495  *	is busy (during sending a data frame) timer expiration event must be
1496  *	queued. Otherwise this event can be sent to connection state machine.
1497  *	Queued events will process by llc_backlog_rcv function after sending
1498  *	data frame.
1499  */
1500 static void llc_process_tmr_ev(struct sock *sk, struct sk_buff *skb)
1501 {
1502 	if (llc_sk(sk)->state == LLC_CONN_OUT_OF_SVC) {
1503 		printk(KERN_WARNING "%s: timer called on closed connection\n",
1504 		       __FUNCTION__);
1505 		kfree_skb(skb);
1506 	} else {
1507 		if (!sock_owned_by_user(sk))
1508 			llc_conn_state_process(sk, skb);
1509 		else {
1510 			llc_set_backlog_type(skb, LLC_EVENT);
1511 			sk_add_backlog(sk, skb);
1512 		}
1513 	}
1514 }
1515