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 <linux/slab.h>
22#include <net/llc_conn.h>
23#include <net/llc_sap.h>
24#include <net/sock.h>
25#include <net/llc_c_ev.h>
26#include <net/llc_c_ac.h>
27#include <net/llc_c_st.h>
28#include <net/llc_pdu.h>
29#include <net/llc.h>
30
31
32static int llc_conn_ac_inc_vs_by_1(struct sock *sk, struct sk_buff *skb);
33static void llc_process_tmr_ev(struct sock *sk, struct sk_buff *skb);
34static int llc_conn_ac_data_confirm(struct sock *sk, struct sk_buff *ev);
35
36static int llc_conn_ac_inc_npta_value(struct sock *sk, struct sk_buff *skb);
37
38static int llc_conn_ac_send_rr_rsp_f_set_ackpf(struct sock *sk,
39					       struct sk_buff *skb);
40
41static int llc_conn_ac_set_p_flag_1(struct sock *sk, struct sk_buff *skb);
42
43#define INCORRECT 0
44
45int 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
61int llc_conn_ac_conn_ind(struct sock *sk, struct sk_buff *skb)
62{
63	struct llc_conn_state_ev *ev = llc_conn_ev(skb);
64
65	ev->ind_prim = LLC_CONN_PRIM;
66	return 0;
67}
68
69int llc_conn_ac_conn_confirm(struct sock *sk, struct sk_buff *skb)
70{
71	struct llc_conn_state_ev *ev = llc_conn_ev(skb);
72
73	ev->cfm_prim = LLC_CONN_PRIM;
74	return 0;
75}
76
77static int llc_conn_ac_data_confirm(struct sock *sk, struct sk_buff *skb)
78{
79	struct llc_conn_state_ev *ev = llc_conn_ev(skb);
80
81	ev->cfm_prim = LLC_DATA_PRIM;
82	return 0;
83}
84
85int llc_conn_ac_data_ind(struct sock *sk, struct sk_buff *skb)
86{
87	llc_conn_rtn_pdu(sk, skb);
88	return 0;
89}
90
91int llc_conn_ac_disc_ind(struct sock *sk, struct sk_buff *skb)
92{
93	struct llc_conn_state_ev *ev = llc_conn_ev(skb);
94	u8 reason = 0;
95	int rc = 0;
96
97	if (ev->type == LLC_CONN_EV_TYPE_PDU) {
98		struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
99
100		if (LLC_PDU_IS_RSP(pdu) &&
101		    LLC_PDU_TYPE_IS_U(pdu) &&
102		    LLC_U_PDU_RSP(pdu) == LLC_2_PDU_RSP_DM)
103			reason = LLC_DISC_REASON_RX_DM_RSP_PDU;
104		else if (LLC_PDU_IS_CMD(pdu) &&
105			   LLC_PDU_TYPE_IS_U(pdu) &&
106			   LLC_U_PDU_CMD(pdu) == LLC_2_PDU_CMD_DISC)
107			reason = LLC_DISC_REASON_RX_DISC_CMD_PDU;
108	} else if (ev->type == LLC_CONN_EV_TYPE_ACK_TMR)
109		reason = LLC_DISC_REASON_ACK_TMR_EXP;
110	else
111		rc = -EINVAL;
112	if (!rc) {
113		ev->reason   = reason;
114		ev->ind_prim = LLC_DISC_PRIM;
115	}
116	return rc;
117}
118
119int llc_conn_ac_disc_confirm(struct sock *sk, struct sk_buff *skb)
120{
121	struct llc_conn_state_ev *ev = llc_conn_ev(skb);
122
123	ev->reason   = ev->status;
124	ev->cfm_prim = LLC_DISC_PRIM;
125	return 0;
126}
127
128int llc_conn_ac_rst_ind(struct sock *sk, struct sk_buff *skb)
129{
130	u8 reason = 0;
131	int rc = 1;
132	struct llc_conn_state_ev *ev = llc_conn_ev(skb);
133	struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
134	struct llc_sock *llc = llc_sk(sk);
135
136	switch (ev->type) {
137	case LLC_CONN_EV_TYPE_PDU:
138		if (LLC_PDU_IS_RSP(pdu) &&
139		    LLC_PDU_TYPE_IS_U(pdu) &&
140		    LLC_U_PDU_RSP(pdu) == LLC_2_PDU_RSP_FRMR) {
141			reason = LLC_RESET_REASON_LOCAL;
142			rc = 0;
143		} else if (LLC_PDU_IS_CMD(pdu) &&
144			   LLC_PDU_TYPE_IS_U(pdu) &&
145			   LLC_U_PDU_CMD(pdu) == LLC_2_PDU_CMD_SABME) {
146			reason = LLC_RESET_REASON_REMOTE;
147			rc = 0;
148		}
149		break;
150	case LLC_CONN_EV_TYPE_ACK_TMR:
151	case LLC_CONN_EV_TYPE_P_TMR:
152	case LLC_CONN_EV_TYPE_REJ_TMR:
153	case LLC_CONN_EV_TYPE_BUSY_TMR:
154		if (llc->retry_count > llc->n2) {
155			reason = LLC_RESET_REASON_LOCAL;
156			rc = 0;
157		}
158		break;
159	}
160	if (!rc) {
161		ev->reason   = reason;
162		ev->ind_prim = LLC_RESET_PRIM;
163	}
164	return rc;
165}
166
167int llc_conn_ac_rst_confirm(struct sock *sk, struct sk_buff *skb)
168{
169	struct llc_conn_state_ev *ev = llc_conn_ev(skb);
170
171	ev->reason   = 0;
172	ev->cfm_prim = LLC_RESET_PRIM;
173	return 0;
174}
175
176int llc_conn_ac_clear_remote_busy_if_f_eq_1(struct sock *sk,
177					    struct sk_buff *skb)
178{
179	struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
180
181	if (LLC_PDU_IS_RSP(pdu) &&
182	    LLC_PDU_TYPE_IS_I(pdu) &&
183	    LLC_I_PF_IS_1(pdu) && llc_sk(sk)->ack_pf)
184		llc_conn_ac_clear_remote_busy(sk, skb);
185	return 0;
186}
187
188int llc_conn_ac_stop_rej_tmr_if_data_flag_eq_2(struct sock *sk,
189					       struct sk_buff *skb)
190{
191	struct llc_sock *llc = llc_sk(sk);
192
193	if (llc->data_flag == 2)
194		del_timer(&llc->rej_sent_timer.timer);
195	return 0;
196}
197
198int llc_conn_ac_send_disc_cmd_p_set_x(struct sock *sk, struct sk_buff *skb)
199{
200	int rc = -ENOBUFS;
201	struct llc_sock *llc = llc_sk(sk);
202	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, 0);
203
204	if (nskb) {
205		struct llc_sap *sap = llc->sap;
206
207		llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
208				    llc->daddr.lsap, LLC_PDU_CMD);
209		llc_pdu_init_as_disc_cmd(nskb, 1);
210		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
211		if (unlikely(rc))
212			goto free;
213		llc_conn_send_pdu(sk, nskb);
214		llc_conn_ac_set_p_flag_1(sk, skb);
215	}
216out:
217	return rc;
218free:
219	kfree_skb(nskb);
220	goto out;
221}
222
223int llc_conn_ac_send_dm_rsp_f_set_p(struct sock *sk, struct sk_buff *skb)
224{
225	int rc = -ENOBUFS;
226	struct llc_sock *llc = llc_sk(sk);
227	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, 0);
228
229	if (nskb) {
230		struct llc_sap *sap = llc->sap;
231		u8 f_bit;
232
233		llc_pdu_decode_pf_bit(skb, &f_bit);
234		llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
235				    llc->daddr.lsap, LLC_PDU_RSP);
236		llc_pdu_init_as_dm_rsp(nskb, f_bit);
237		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
238		if (unlikely(rc))
239			goto free;
240		llc_conn_send_pdu(sk, nskb);
241	}
242out:
243	return rc;
244free:
245	kfree_skb(nskb);
246	goto out;
247}
248
249int llc_conn_ac_send_dm_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
250{
251	int rc = -ENOBUFS;
252	struct llc_sock *llc = llc_sk(sk);
253	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, 0);
254
255	if (nskb) {
256		struct llc_sap *sap = llc->sap;
257
258		llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
259				    llc->daddr.lsap, LLC_PDU_RSP);
260		llc_pdu_init_as_dm_rsp(nskb, 1);
261		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
262		if (unlikely(rc))
263			goto free;
264		llc_conn_send_pdu(sk, nskb);
265	}
266out:
267	return rc;
268free:
269	kfree_skb(nskb);
270	goto out;
271}
272
273int llc_conn_ac_send_frmr_rsp_f_set_x(struct sock *sk, struct sk_buff *skb)
274{
275	u8 f_bit;
276	int rc = -ENOBUFS;
277	struct sk_buff *nskb;
278	struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
279	struct llc_sock *llc = llc_sk(sk);
280
281	llc->rx_pdu_hdr = *((u32 *)pdu);
282	if (LLC_PDU_IS_CMD(pdu))
283		llc_pdu_decode_pf_bit(skb, &f_bit);
284	else
285		f_bit = 0;
286	nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U,
287			       sizeof(struct llc_frmr_info));
288	if (nskb) {
289		struct llc_sap *sap = llc->sap;
290
291		llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
292				    llc->daddr.lsap, LLC_PDU_RSP);
293		llc_pdu_init_as_frmr_rsp(nskb, pdu, f_bit, llc->vS,
294					 llc->vR, INCORRECT);
295		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
296		if (unlikely(rc))
297			goto free;
298		llc_conn_send_pdu(sk, nskb);
299	}
300out:
301	return rc;
302free:
303	kfree_skb(nskb);
304	goto out;
305}
306
307int llc_conn_ac_resend_frmr_rsp_f_set_0(struct sock *sk, struct sk_buff *skb)
308{
309	int rc = -ENOBUFS;
310	struct llc_sock *llc = llc_sk(sk);
311	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U,
312					       sizeof(struct llc_frmr_info));
313
314	if (nskb) {
315		struct llc_sap *sap = llc->sap;
316		struct llc_pdu_sn *pdu = (struct llc_pdu_sn *)&llc->rx_pdu_hdr;
317
318		llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
319				    llc->daddr.lsap, LLC_PDU_RSP);
320		llc_pdu_init_as_frmr_rsp(nskb, pdu, 0, llc->vS,
321					 llc->vR, INCORRECT);
322		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
323		if (unlikely(rc))
324			goto free;
325		llc_conn_send_pdu(sk, nskb);
326	}
327out:
328	return rc;
329free:
330	kfree_skb(nskb);
331	goto out;
332}
333
334int llc_conn_ac_resend_frmr_rsp_f_set_p(struct sock *sk, struct sk_buff *skb)
335{
336	u8 f_bit;
337	int rc = -ENOBUFS;
338	struct sk_buff *nskb;
339	struct llc_sock *llc = llc_sk(sk);
340
341	llc_pdu_decode_pf_bit(skb, &f_bit);
342	nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U,
343			       sizeof(struct llc_frmr_info));
344	if (nskb) {
345		struct llc_sap *sap = llc->sap;
346		struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
347
348		llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
349				    llc->daddr.lsap, LLC_PDU_RSP);
350		llc_pdu_init_as_frmr_rsp(nskb, pdu, f_bit, llc->vS,
351					 llc->vR, INCORRECT);
352		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
353		if (unlikely(rc))
354			goto free;
355		llc_conn_send_pdu(sk, nskb);
356	}
357out:
358	return rc;
359free:
360	kfree_skb(nskb);
361	goto out;
362}
363
364int llc_conn_ac_send_i_cmd_p_set_1(struct sock *sk, struct sk_buff *skb)
365{
366	int rc;
367	struct llc_sock *llc = llc_sk(sk);
368	struct llc_sap *sap = llc->sap;
369
370	llc_pdu_header_init(skb, LLC_PDU_TYPE_I, sap->laddr.lsap,
371			    llc->daddr.lsap, LLC_PDU_CMD);
372	llc_pdu_init_as_i_cmd(skb, 1, llc->vS, llc->vR);
373	rc = llc_mac_hdr_init(skb, llc->dev->dev_addr, llc->daddr.mac);
374	if (likely(!rc)) {
375		llc_conn_send_pdu(sk, skb);
376		llc_conn_ac_inc_vs_by_1(sk, skb);
377	}
378	return rc;
379}
380
381static int llc_conn_ac_send_i_cmd_p_set_0(struct sock *sk, struct sk_buff *skb)
382{
383	int rc;
384	struct llc_sock *llc = llc_sk(sk);
385	struct llc_sap *sap = llc->sap;
386
387	llc_pdu_header_init(skb, LLC_PDU_TYPE_I, sap->laddr.lsap,
388			    llc->daddr.lsap, LLC_PDU_CMD);
389	llc_pdu_init_as_i_cmd(skb, 0, llc->vS, llc->vR);
390	rc = llc_mac_hdr_init(skb, llc->dev->dev_addr, llc->daddr.mac);
391	if (likely(!rc)) {
392		llc_conn_send_pdu(sk, skb);
393		llc_conn_ac_inc_vs_by_1(sk, skb);
394	}
395	return rc;
396}
397
398int llc_conn_ac_send_i_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
399{
400	int rc;
401	struct llc_sock *llc = llc_sk(sk);
402	struct llc_sap *sap = llc->sap;
403
404	llc_pdu_header_init(skb, LLC_PDU_TYPE_I, sap->laddr.lsap,
405			    llc->daddr.lsap, LLC_PDU_CMD);
406	llc_pdu_init_as_i_cmd(skb, 0, llc->vS, llc->vR);
407	rc = llc_mac_hdr_init(skb, llc->dev->dev_addr, llc->daddr.mac);
408	if (likely(!rc)) {
409		llc_conn_send_pdu(sk, skb);
410		llc_conn_ac_inc_vs_by_1(sk, skb);
411	}
412	return 0;
413}
414
415int llc_conn_ac_resend_i_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
416{
417	struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
418	u8 nr = LLC_I_GET_NR(pdu);
419
420	llc_conn_resend_i_pdu_as_cmd(sk, nr, 0);
421	return 0;
422}
423
424int llc_conn_ac_resend_i_xxx_x_set_0_or_send_rr(struct sock *sk,
425						struct sk_buff *skb)
426{
427	u8 nr;
428	struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
429	int rc = -ENOBUFS;
430	struct llc_sock *llc = llc_sk(sk);
431	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, 0);
432
433	if (nskb) {
434		struct llc_sap *sap = llc->sap;
435
436		llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
437				    llc->daddr.lsap, LLC_PDU_RSP);
438		llc_pdu_init_as_rr_rsp(nskb, 0, llc->vR);
439		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
440		if (likely(!rc))
441			llc_conn_send_pdu(sk, nskb);
442		else
443			kfree_skb(skb);
444	}
445	if (rc) {
446		nr = LLC_I_GET_NR(pdu);
447		rc = 0;
448		llc_conn_resend_i_pdu_as_cmd(sk, nr, 0);
449	}
450	return rc;
451}
452
453int llc_conn_ac_resend_i_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
454{
455	struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
456	u8 nr = LLC_I_GET_NR(pdu);
457
458	llc_conn_resend_i_pdu_as_rsp(sk, nr, 1);
459	return 0;
460}
461
462int llc_conn_ac_send_rej_cmd_p_set_1(struct sock *sk, struct sk_buff *skb)
463{
464	int rc = -ENOBUFS;
465	struct llc_sock *llc = llc_sk(sk);
466	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
467
468	if (nskb) {
469		struct llc_sap *sap = llc->sap;
470
471		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
472				    llc->daddr.lsap, LLC_PDU_CMD);
473		llc_pdu_init_as_rej_cmd(nskb, 1, llc->vR);
474		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
475		if (unlikely(rc))
476			goto free;
477		llc_conn_send_pdu(sk, nskb);
478	}
479out:
480	return rc;
481free:
482	kfree_skb(nskb);
483	goto out;
484}
485
486int llc_conn_ac_send_rej_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
487{
488	int rc = -ENOBUFS;
489	struct llc_sock *llc = llc_sk(sk);
490	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
491
492	if (nskb) {
493		struct llc_sap *sap = llc->sap;
494
495		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
496				    llc->daddr.lsap, LLC_PDU_RSP);
497		llc_pdu_init_as_rej_rsp(nskb, 1, llc->vR);
498		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
499		if (unlikely(rc))
500			goto free;
501		llc_conn_send_pdu(sk, nskb);
502	}
503out:
504	return rc;
505free:
506	kfree_skb(nskb);
507	goto out;
508}
509
510int llc_conn_ac_send_rej_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
511{
512	int rc = -ENOBUFS;
513	struct llc_sock *llc = llc_sk(sk);
514	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
515
516	if (nskb) {
517		struct llc_sap *sap = llc->sap;
518
519		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
520				    llc->daddr.lsap, LLC_PDU_RSP);
521		llc_pdu_init_as_rej_rsp(nskb, 0, llc->vR);
522		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
523		if (unlikely(rc))
524			goto free;
525		llc_conn_send_pdu(sk, nskb);
526	}
527out:
528	return rc;
529free:
530	kfree_skb(nskb);
531	goto out;
532}
533
534int llc_conn_ac_send_rnr_cmd_p_set_1(struct sock *sk, struct sk_buff *skb)
535{
536	int rc = -ENOBUFS;
537	struct llc_sock *llc = llc_sk(sk);
538	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
539
540	if (nskb) {
541		struct llc_sap *sap = llc->sap;
542
543		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
544				    llc->daddr.lsap, LLC_PDU_CMD);
545		llc_pdu_init_as_rnr_cmd(nskb, 1, llc->vR);
546		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
547		if (unlikely(rc))
548			goto free;
549		llc_conn_send_pdu(sk, nskb);
550	}
551out:
552	return rc;
553free:
554	kfree_skb(nskb);
555	goto out;
556}
557
558int llc_conn_ac_send_rnr_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
559{
560	int rc = -ENOBUFS;
561	struct llc_sock *llc = llc_sk(sk);
562	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
563
564	if (nskb) {
565		struct llc_sap *sap = llc->sap;
566
567		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
568				    llc->daddr.lsap, LLC_PDU_RSP);
569		llc_pdu_init_as_rnr_rsp(nskb, 1, llc->vR);
570		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
571		if (unlikely(rc))
572			goto free;
573		llc_conn_send_pdu(sk, nskb);
574	}
575out:
576	return rc;
577free:
578	kfree_skb(nskb);
579	goto out;
580}
581
582int llc_conn_ac_send_rnr_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
583{
584	int rc = -ENOBUFS;
585	struct llc_sock *llc = llc_sk(sk);
586	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
587
588	if (nskb) {
589		struct llc_sap *sap = llc->sap;
590
591		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
592				    llc->daddr.lsap, LLC_PDU_RSP);
593		llc_pdu_init_as_rnr_rsp(nskb, 0, llc->vR);
594		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
595		if (unlikely(rc))
596			goto free;
597		llc_conn_send_pdu(sk, nskb);
598	}
599out:
600	return rc;
601free:
602	kfree_skb(nskb);
603	goto out;
604}
605
606int llc_conn_ac_set_remote_busy(struct sock *sk, struct sk_buff *skb)
607{
608	struct llc_sock *llc = llc_sk(sk);
609
610	if (!llc->remote_busy_flag) {
611		llc->remote_busy_flag = 1;
612		mod_timer(&llc->busy_state_timer.timer,
613			 jiffies + llc->busy_state_timer.expire);
614	}
615	return 0;
616}
617
618int llc_conn_ac_opt_send_rnr_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
619{
620	int rc = -ENOBUFS;
621	struct llc_sock *llc = llc_sk(sk);
622	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
623
624	if (nskb) {
625		struct llc_sap *sap = llc->sap;
626
627		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
628				    llc->daddr.lsap, LLC_PDU_RSP);
629		llc_pdu_init_as_rnr_rsp(nskb, 0, llc->vR);
630		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
631		if (unlikely(rc))
632			goto free;
633		llc_conn_send_pdu(sk, nskb);
634	}
635out:
636	return rc;
637free:
638	kfree_skb(nskb);
639	goto out;
640}
641
642int llc_conn_ac_send_rr_cmd_p_set_1(struct sock *sk, struct sk_buff *skb)
643{
644	int rc = -ENOBUFS;
645	struct llc_sock *llc = llc_sk(sk);
646	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
647
648	if (nskb) {
649		struct llc_sap *sap = llc->sap;
650
651		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
652				    llc->daddr.lsap, LLC_PDU_CMD);
653		llc_pdu_init_as_rr_cmd(nskb, 1, llc->vR);
654		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
655		if (unlikely(rc))
656			goto free;
657		llc_conn_send_pdu(sk, nskb);
658	}
659out:
660	return rc;
661free:
662	kfree_skb(nskb);
663	goto out;
664}
665
666int llc_conn_ac_send_rr_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
667{
668	int rc = -ENOBUFS;
669	struct llc_sock *llc = llc_sk(sk);
670	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
671
672	if (nskb) {
673		struct llc_sap *sap = llc->sap;
674		u8 f_bit = 1;
675
676		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
677				    llc->daddr.lsap, LLC_PDU_RSP);
678		llc_pdu_init_as_rr_rsp(nskb, f_bit, llc->vR);
679		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
680		if (unlikely(rc))
681			goto free;
682		llc_conn_send_pdu(sk, nskb);
683	}
684out:
685	return rc;
686free:
687	kfree_skb(nskb);
688	goto out;
689}
690
691int llc_conn_ac_send_ack_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
692{
693	int rc = -ENOBUFS;
694	struct llc_sock *llc = llc_sk(sk);
695	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
696
697	if (nskb) {
698		struct llc_sap *sap = llc->sap;
699
700		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
701				    llc->daddr.lsap, LLC_PDU_RSP);
702		llc_pdu_init_as_rr_rsp(nskb, 1, llc->vR);
703		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
704		if (unlikely(rc))
705			goto free;
706		llc_conn_send_pdu(sk, nskb);
707	}
708out:
709	return rc;
710free:
711	kfree_skb(nskb);
712	goto out;
713}
714
715int llc_conn_ac_send_rr_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
716{
717	int rc = -ENOBUFS;
718	struct llc_sock *llc = llc_sk(sk);
719	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
720
721	if (nskb) {
722		struct llc_sap *sap = llc->sap;
723
724		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
725				    llc->daddr.lsap, LLC_PDU_RSP);
726		llc_pdu_init_as_rr_rsp(nskb, 0, llc->vR);
727		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
728		if (unlikely(rc))
729			goto free;
730		llc_conn_send_pdu(sk, nskb);
731	}
732out:
733	return rc;
734free:
735	kfree_skb(nskb);
736	goto out;
737}
738
739int llc_conn_ac_send_ack_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
740{
741	int rc = -ENOBUFS;
742	struct llc_sock *llc = llc_sk(sk);
743	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
744
745	if (nskb) {
746		struct llc_sap *sap = llc->sap;
747
748		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
749				    llc->daddr.lsap, LLC_PDU_RSP);
750		llc_pdu_init_as_rr_rsp(nskb, 0, llc->vR);
751		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
752		if (unlikely(rc))
753			goto free;
754		llc_conn_send_pdu(sk, nskb);
755	}
756out:
757	return rc;
758free:
759	kfree_skb(nskb);
760	goto out;
761}
762
763void llc_conn_set_p_flag(struct sock *sk, u8 value)
764{
765	int state_changed = llc_sk(sk)->p_flag && !value;
766
767	llc_sk(sk)->p_flag = value;
768
769	if (state_changed)
770		sk->sk_state_change(sk);
771}
772
773int llc_conn_ac_send_sabme_cmd_p_set_x(struct sock *sk, struct sk_buff *skb)
774{
775	int rc = -ENOBUFS;
776	struct llc_sock *llc = llc_sk(sk);
777	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, 0);
778
779	if (nskb) {
780		struct llc_sap *sap = llc->sap;
781		u8 *dmac = llc->daddr.mac;
782
783		if (llc->dev->flags & IFF_LOOPBACK)
784			dmac = llc->dev->dev_addr;
785		llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
786				    llc->daddr.lsap, LLC_PDU_CMD);
787		llc_pdu_init_as_sabme_cmd(nskb, 1);
788		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, dmac);
789		if (unlikely(rc))
790			goto free;
791		llc_conn_send_pdu(sk, nskb);
792		llc_conn_set_p_flag(sk, 1);
793	}
794out:
795	return rc;
796free:
797	kfree_skb(nskb);
798	goto out;
799}
800
801int llc_conn_ac_send_ua_rsp_f_set_p(struct sock *sk, struct sk_buff *skb)
802{
803	u8 f_bit;
804	int rc = -ENOBUFS;
805	struct llc_sock *llc = llc_sk(sk);
806	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, 0);
807
808	llc_pdu_decode_pf_bit(skb, &f_bit);
809	if (nskb) {
810		struct llc_sap *sap = llc->sap;
811
812		nskb->dev = llc->dev;
813		llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
814				    llc->daddr.lsap, LLC_PDU_RSP);
815		llc_pdu_init_as_ua_rsp(nskb, f_bit);
816		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
817		if (unlikely(rc))
818			goto free;
819		llc_conn_send_pdu(sk, nskb);
820	}
821out:
822	return rc;
823free:
824	kfree_skb(nskb);
825	goto out;
826}
827
828int llc_conn_ac_set_s_flag_0(struct sock *sk, struct sk_buff *skb)
829{
830	llc_sk(sk)->s_flag = 0;
831	return 0;
832}
833
834int llc_conn_ac_set_s_flag_1(struct sock *sk, struct sk_buff *skb)
835{
836	llc_sk(sk)->s_flag = 1;
837	return 0;
838}
839
840int llc_conn_ac_start_p_timer(struct sock *sk, struct sk_buff *skb)
841{
842	struct llc_sock *llc = llc_sk(sk);
843
844	llc_conn_set_p_flag(sk, 1);
845	mod_timer(&llc->pf_cycle_timer.timer,
846		  jiffies + llc->pf_cycle_timer.expire);
847	return 0;
848}
849
850/**
851 *	llc_conn_ac_send_ack_if_needed - check if ack is needed
852 *	@sk: current connection structure
853 *	@skb: current event
854 *
855 *	Checks number of received PDUs which have not been acknowledged, yet,
856 *	If number of them reaches to "npta"(Number of PDUs To Acknowledge) then
857 *	sends an RR response as acknowledgement for them.  Returns 0 for
858 *	success, 1 otherwise.
859 */
860int llc_conn_ac_send_ack_if_needed(struct sock *sk, struct sk_buff *skb)
861{
862	u8 pf_bit;
863	struct llc_sock *llc = llc_sk(sk);
864
865	llc_pdu_decode_pf_bit(skb, &pf_bit);
866	llc->ack_pf |= pf_bit & 1;
867	if (!llc->ack_must_be_send) {
868		llc->first_pdu_Ns = llc->vR;
869		llc->ack_must_be_send = 1;
870		llc->ack_pf = pf_bit & 1;
871	}
872	if (((llc->vR - llc->first_pdu_Ns + 1 + LLC_2_SEQ_NBR_MODULO)
873			% LLC_2_SEQ_NBR_MODULO) >= llc->npta) {
874		llc_conn_ac_send_rr_rsp_f_set_ackpf(sk, skb);
875		llc->ack_must_be_send	= 0;
876		llc->ack_pf		= 0;
877		llc_conn_ac_inc_npta_value(sk, skb);
878	}
879	return 0;
880}
881
882/**
883 *	llc_conn_ac_rst_sendack_flag - resets ack_must_be_send flag
884 *	@sk: current connection structure
885 *	@skb: current event
886 *
887 *	This action resets ack_must_be_send flag of given connection, this flag
888 *	indicates if there is any PDU which has not been acknowledged yet.
889 *	Returns 0 for success, 1 otherwise.
890 */
891int llc_conn_ac_rst_sendack_flag(struct sock *sk, struct sk_buff *skb)
892{
893	llc_sk(sk)->ack_must_be_send = llc_sk(sk)->ack_pf = 0;
894	return 0;
895}
896
897/**
898 *	llc_conn_ac_send_i_rsp_f_set_ackpf - acknowledge received PDUs
899 *	@sk: current connection structure
900 *	@skb: current event
901 *
902 *	Sends an I response PDU with f-bit set to ack_pf flag as acknowledge to
903 *	all received PDUs which have not been acknowledged, yet. ack_pf flag is
904 *	set to one if one PDU with p-bit set to one is received.  Returns 0 for
905 *	success, 1 otherwise.
906 */
907static int llc_conn_ac_send_i_rsp_f_set_ackpf(struct sock *sk,
908					      struct sk_buff *skb)
909{
910	int rc;
911	struct llc_sock *llc = llc_sk(sk);
912	struct llc_sap *sap = llc->sap;
913
914	llc_pdu_header_init(skb, LLC_PDU_TYPE_I, sap->laddr.lsap,
915			    llc->daddr.lsap, LLC_PDU_RSP);
916	llc_pdu_init_as_i_cmd(skb, llc->ack_pf, llc->vS, llc->vR);
917	rc = llc_mac_hdr_init(skb, llc->dev->dev_addr, llc->daddr.mac);
918	if (likely(!rc)) {
919		llc_conn_send_pdu(sk, skb);
920		llc_conn_ac_inc_vs_by_1(sk, skb);
921	}
922	return rc;
923}
924
925/**
926 *	llc_conn_ac_send_i_as_ack - sends an I-format PDU to acknowledge rx PDUs
927 *	@sk: current connection structure.
928 *	@skb: current event.
929 *
930 *	This action sends an I-format PDU as acknowledge to received PDUs which
931 *	have not been acknowledged, yet, if there is any. By using of this
932 *	action number of acknowledgements decreases, this technic is called
933 *	piggy backing. Returns 0 for success, 1 otherwise.
934 */
935int llc_conn_ac_send_i_as_ack(struct sock *sk, struct sk_buff *skb)
936{
937	struct llc_sock *llc = llc_sk(sk);
938
939	if (llc->ack_must_be_send) {
940		llc_conn_ac_send_i_rsp_f_set_ackpf(sk, skb);
941		llc->ack_must_be_send = 0 ;
942		llc->ack_pf = 0;
943	} else
944		llc_conn_ac_send_i_cmd_p_set_0(sk, skb);
945	return 0;
946}
947
948/**
949 *	llc_conn_ac_send_rr_rsp_f_set_ackpf - ack all rx PDUs not yet acked
950 *	@sk: current connection structure.
951 *	@skb: current event.
952 *
953 *	This action sends an RR response with f-bit set to ack_pf flag as
954 *	acknowledge to all received PDUs which have not been acknowledged, yet,
955 *	if there is any. ack_pf flag indicates if a PDU has been received with
956 *	p-bit set to one. Returns 0 for success, 1 otherwise.
957 */
958static int llc_conn_ac_send_rr_rsp_f_set_ackpf(struct sock *sk,
959					       struct sk_buff *skb)
960{
961	int rc = -ENOBUFS;
962	struct llc_sock *llc = llc_sk(sk);
963	struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
964
965	if (nskb) {
966		struct llc_sap *sap = llc->sap;
967
968		llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
969				    llc->daddr.lsap, LLC_PDU_RSP);
970		llc_pdu_init_as_rr_rsp(nskb, llc->ack_pf, llc->vR);
971		rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
972		if (unlikely(rc))
973			goto free;
974		llc_conn_send_pdu(sk, nskb);
975	}
976out:
977	return rc;
978free:
979	kfree_skb(nskb);
980	goto out;
981}
982
983/**
984 *	llc_conn_ac_inc_npta_value - tries to make value of npta greater
985 *	@sk: current connection structure.
986 *	@skb: current event.
987 *
988 *	After "inc_cntr" times calling of this action, "npta" increase by one.
989 *	this action tries to make vale of "npta" greater as possible; number of
990 *	acknowledgements decreases by increasing of "npta". Returns 0 for
991 *	success, 1 otherwise.
992 */
993static int llc_conn_ac_inc_npta_value(struct sock *sk, struct sk_buff *skb)
994{
995	struct llc_sock *llc = llc_sk(sk);
996
997	if (!llc->inc_cntr) {
998		llc->dec_step = 0;
999		llc->dec_cntr = llc->inc_cntr = 2;
1000		++llc->npta;
1001		if (llc->npta > (u8) ~LLC_2_SEQ_NBR_MODULO)
1002			llc->npta = (u8) ~LLC_2_SEQ_NBR_MODULO;
1003	} else
1004		--llc->inc_cntr;
1005	return 0;
1006}
1007
1008/**
1009 *	llc_conn_ac_adjust_npta_by_rr - decreases "npta" by one
1010 *	@sk: current connection structure.
1011 *	@skb: current event.
1012 *
1013 *	After receiving "dec_cntr" times RR command, this action decreases
1014 *	"npta" by one. Returns 0 for success, 1 otherwise.
1015 */
1016int llc_conn_ac_adjust_npta_by_rr(struct sock *sk, struct sk_buff *skb)
1017{
1018	struct llc_sock *llc = llc_sk(sk);
1019
1020	if (!llc->connect_step && !llc->remote_busy_flag) {
1021		if (!llc->dec_step) {
1022			if (!llc->dec_cntr) {
1023				llc->inc_cntr = llc->dec_cntr = 2;
1024				if (llc->npta > 0)
1025					llc->npta = llc->npta - 1;
1026			} else
1027				llc->dec_cntr -=1;
1028		}
1029	} else
1030		llc->connect_step = 0 ;
1031	return 0;
1032}
1033
1034/**
1035 *	llc_conn_ac_adjust_npta_by_rnr - decreases "npta" by one
1036 *	@sk: current connection structure.
1037 *	@skb: current event.
1038 *
1039 *	After receiving "dec_cntr" times RNR command, this action decreases
1040 *	"npta" by one. Returns 0 for success, 1 otherwise.
1041 */
1042int llc_conn_ac_adjust_npta_by_rnr(struct sock *sk, struct sk_buff *skb)
1043{
1044	struct llc_sock *llc = llc_sk(sk);
1045
1046	if (llc->remote_busy_flag)
1047		if (!llc->dec_step) {
1048			if (!llc->dec_cntr) {
1049				llc->inc_cntr = llc->dec_cntr = 2;
1050				if (llc->npta > 0)
1051					--llc->npta;
1052			} else
1053				--llc->dec_cntr;
1054		}
1055	return 0;
1056}
1057
1058/**
1059 *	llc_conn_ac_dec_tx_win_size - decreases tx window size
1060 *	@sk: current connection structure.
1061 *	@skb: current event.
1062 *
1063 *	After receiving of a REJ command or response, transmit window size is
1064 *	decreased by number of PDUs which are outstanding yet. Returns 0 for
1065 *	success, 1 otherwise.
1066 */
1067int llc_conn_ac_dec_tx_win_size(struct sock *sk, struct sk_buff *skb)
1068{
1069	struct llc_sock *llc = llc_sk(sk);
1070	u8 unacked_pdu = skb_queue_len(&llc->pdu_unack_q);
1071
1072	if (llc->k - unacked_pdu < 1)
1073		llc->k = 1;
1074	else
1075		llc->k -= unacked_pdu;
1076	return 0;
1077}
1078
1079/**
1080 *	llc_conn_ac_inc_tx_win_size - tx window size is inc by 1
1081 *	@sk: current connection structure.
1082 *	@skb: current event.
1083 *
1084 *	After receiving an RR response with f-bit set to one, transmit window
1085 *	size is increased by one. Returns 0 for success, 1 otherwise.
1086 */
1087int llc_conn_ac_inc_tx_win_size(struct sock *sk, struct sk_buff *skb)
1088{
1089	struct llc_sock *llc = llc_sk(sk);
1090
1091	llc->k += 1;
1092	if (llc->k > (u8) ~LLC_2_SEQ_NBR_MODULO)
1093		llc->k = (u8) ~LLC_2_SEQ_NBR_MODULO;
1094	return 0;
1095}
1096
1097int llc_conn_ac_stop_all_timers(struct sock *sk, struct sk_buff *skb)
1098{
1099	struct llc_sock *llc = llc_sk(sk);
1100
1101	del_timer(&llc->pf_cycle_timer.timer);
1102	del_timer(&llc->ack_timer.timer);
1103	del_timer(&llc->rej_sent_timer.timer);
1104	del_timer(&llc->busy_state_timer.timer);
1105	llc->ack_must_be_send = 0;
1106	llc->ack_pf = 0;
1107	return 0;
1108}
1109
1110int llc_conn_ac_stop_other_timers(struct sock *sk, struct sk_buff *skb)
1111{
1112	struct llc_sock *llc = llc_sk(sk);
1113
1114	del_timer(&llc->rej_sent_timer.timer);
1115	del_timer(&llc->pf_cycle_timer.timer);
1116	del_timer(&llc->busy_state_timer.timer);
1117	llc->ack_must_be_send = 0;
1118	llc->ack_pf = 0;
1119	return 0;
1120}
1121
1122int llc_conn_ac_start_ack_timer(struct sock *sk, struct sk_buff *skb)
1123{
1124	struct llc_sock *llc = llc_sk(sk);
1125
1126	mod_timer(&llc->ack_timer.timer, jiffies + llc->ack_timer.expire);
1127	return 0;
1128}
1129
1130int llc_conn_ac_start_rej_timer(struct sock *sk, struct sk_buff *skb)
1131{
1132	struct llc_sock *llc = llc_sk(sk);
1133
1134	mod_timer(&llc->rej_sent_timer.timer,
1135		  jiffies + llc->rej_sent_timer.expire);
1136	return 0;
1137}
1138
1139int llc_conn_ac_start_ack_tmr_if_not_running(struct sock *sk,
1140					     struct sk_buff *skb)
1141{
1142	struct llc_sock *llc = llc_sk(sk);
1143
1144	if (!timer_pending(&llc->ack_timer.timer))
1145		mod_timer(&llc->ack_timer.timer,
1146			  jiffies + llc->ack_timer.expire);
1147	return 0;
1148}
1149
1150int llc_conn_ac_stop_ack_timer(struct sock *sk, struct sk_buff *skb)
1151{
1152	del_timer(&llc_sk(sk)->ack_timer.timer);
1153	return 0;
1154}
1155
1156int llc_conn_ac_stop_p_timer(struct sock *sk, struct sk_buff *skb)
1157{
1158	struct llc_sock *llc = llc_sk(sk);
1159
1160	del_timer(&llc->pf_cycle_timer.timer);
1161	llc_conn_set_p_flag(sk, 0);
1162	return 0;
1163}
1164
1165int llc_conn_ac_stop_rej_timer(struct sock *sk, struct sk_buff *skb)
1166{
1167	del_timer(&llc_sk(sk)->rej_sent_timer.timer);
1168	return 0;
1169}
1170
1171int llc_conn_ac_upd_nr_received(struct sock *sk, struct sk_buff *skb)
1172{
1173	int acked;
1174	u16 unacked = 0;
1175	struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
1176	struct llc_sock *llc = llc_sk(sk);
1177
1178	llc->last_nr = PDU_SUPV_GET_Nr(pdu);
1179	acked = llc_conn_remove_acked_pdus(sk, llc->last_nr, &unacked);
1180	/* On loopback we don't queue I frames in unack_pdu_q queue. */
1181	if (acked > 0 || (llc->dev->flags & IFF_LOOPBACK)) {
1182		llc->retry_count = 0;
1183		del_timer(&llc->ack_timer.timer);
1184		if (llc->failed_data_req) {
1185			/* already, we did not accept data from upper layer
1186			 * (tx_window full or unacceptable state). Now, we
1187			 * can send data and must inform to upper layer.
1188			 */
1189			llc->failed_data_req = 0;
1190			llc_conn_ac_data_confirm(sk, skb);
1191		}
1192		if (unacked)
1193			mod_timer(&llc->ack_timer.timer,
1194				  jiffies + llc->ack_timer.expire);
1195	} else if (llc->failed_data_req) {
1196		u8 f_bit;
1197
1198		llc_pdu_decode_pf_bit(skb, &f_bit);
1199		if (f_bit == 1) {
1200			llc->failed_data_req = 0;
1201			llc_conn_ac_data_confirm(sk, skb);
1202		}
1203	}
1204	return 0;
1205}
1206
1207int llc_conn_ac_upd_p_flag(struct sock *sk, struct sk_buff *skb)
1208{
1209	struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
1210
1211	if (LLC_PDU_IS_RSP(pdu)) {
1212		u8 f_bit;
1213
1214		llc_pdu_decode_pf_bit(skb, &f_bit);
1215		if (f_bit) {
1216			llc_conn_set_p_flag(sk, 0);
1217			llc_conn_ac_stop_p_timer(sk, skb);
1218		}
1219	}
1220	return 0;
1221}
1222
1223int llc_conn_ac_set_data_flag_2(struct sock *sk, struct sk_buff *skb)
1224{
1225	llc_sk(sk)->data_flag = 2;
1226	return 0;
1227}
1228
1229int llc_conn_ac_set_data_flag_0(struct sock *sk, struct sk_buff *skb)
1230{
1231	llc_sk(sk)->data_flag = 0;
1232	return 0;
1233}
1234
1235int llc_conn_ac_set_data_flag_1(struct sock *sk, struct sk_buff *skb)
1236{
1237	llc_sk(sk)->data_flag = 1;
1238	return 0;
1239}
1240
1241int llc_conn_ac_set_data_flag_1_if_data_flag_eq_0(struct sock *sk,
1242						  struct sk_buff *skb)
1243{
1244	if (!llc_sk(sk)->data_flag)
1245		llc_sk(sk)->data_flag = 1;
1246	return 0;
1247}
1248
1249int llc_conn_ac_set_p_flag_0(struct sock *sk, struct sk_buff *skb)
1250{
1251	llc_conn_set_p_flag(sk, 0);
1252	return 0;
1253}
1254
1255static int llc_conn_ac_set_p_flag_1(struct sock *sk, struct sk_buff *skb)
1256{
1257	llc_conn_set_p_flag(sk, 1);
1258	return 0;
1259}
1260
1261int llc_conn_ac_set_remote_busy_0(struct sock *sk, struct sk_buff *skb)
1262{
1263	llc_sk(sk)->remote_busy_flag = 0;
1264	return 0;
1265}
1266
1267int llc_conn_ac_set_cause_flag_0(struct sock *sk, struct sk_buff *skb)
1268{
1269	llc_sk(sk)->cause_flag = 0;
1270	return 0;
1271}
1272
1273int llc_conn_ac_set_cause_flag_1(struct sock *sk, struct sk_buff *skb)
1274{
1275	llc_sk(sk)->cause_flag = 1;
1276	return 0;
1277}
1278
1279int llc_conn_ac_set_retry_cnt_0(struct sock *sk, struct sk_buff *skb)
1280{
1281	llc_sk(sk)->retry_count = 0;
1282	return 0;
1283}
1284
1285int llc_conn_ac_inc_retry_cnt_by_1(struct sock *sk, struct sk_buff *skb)
1286{
1287	llc_sk(sk)->retry_count++;
1288	return 0;
1289}
1290
1291int llc_conn_ac_set_vr_0(struct sock *sk, struct sk_buff *skb)
1292{
1293	llc_sk(sk)->vR = 0;
1294	return 0;
1295}
1296
1297int llc_conn_ac_inc_vr_by_1(struct sock *sk, struct sk_buff *skb)
1298{
1299	llc_sk(sk)->vR = PDU_GET_NEXT_Vr(llc_sk(sk)->vR);
1300	return 0;
1301}
1302
1303int llc_conn_ac_set_vs_0(struct sock *sk, struct sk_buff *skb)
1304{
1305	llc_sk(sk)->vS = 0;
1306	return 0;
1307}
1308
1309int llc_conn_ac_set_vs_nr(struct sock *sk, struct sk_buff *skb)
1310{
1311	llc_sk(sk)->vS = llc_sk(sk)->last_nr;
1312	return 0;
1313}
1314
1315static int llc_conn_ac_inc_vs_by_1(struct sock *sk, struct sk_buff *skb)
1316{
1317	llc_sk(sk)->vS = (llc_sk(sk)->vS + 1) % LLC_2_SEQ_NBR_MODULO;
1318	return 0;
1319}
1320
1321static void llc_conn_tmr_common_cb(unsigned long timeout_data, u8 type)
1322{
1323	struct sock *sk = (struct sock *)timeout_data;
1324	struct sk_buff *skb = alloc_skb(0, GFP_ATOMIC);
1325
1326	bh_lock_sock(sk);
1327	if (skb) {
1328		struct llc_conn_state_ev *ev = llc_conn_ev(skb);
1329
1330		skb_set_owner_r(skb, sk);
1331		ev->type = type;
1332		llc_process_tmr_ev(sk, skb);
1333	}
1334	bh_unlock_sock(sk);
1335}
1336
1337void llc_conn_pf_cycle_tmr_cb(unsigned long timeout_data)
1338{
1339	llc_conn_tmr_common_cb(timeout_data, LLC_CONN_EV_TYPE_P_TMR);
1340}
1341
1342void llc_conn_busy_tmr_cb(unsigned long timeout_data)
1343{
1344	llc_conn_tmr_common_cb(timeout_data, LLC_CONN_EV_TYPE_BUSY_TMR);
1345}
1346
1347void llc_conn_ack_tmr_cb(unsigned long timeout_data)
1348{
1349	llc_conn_tmr_common_cb(timeout_data, LLC_CONN_EV_TYPE_ACK_TMR);
1350}
1351
1352void llc_conn_rej_tmr_cb(unsigned long timeout_data)
1353{
1354	llc_conn_tmr_common_cb(timeout_data, LLC_CONN_EV_TYPE_REJ_TMR);
1355}
1356
1357int llc_conn_ac_rst_vs(struct sock *sk, struct sk_buff *skb)
1358{
1359	llc_sk(sk)->X = llc_sk(sk)->vS;
1360	llc_conn_ac_set_vs_nr(sk, skb);
1361	return 0;
1362}
1363
1364int llc_conn_ac_upd_vs(struct sock *sk, struct sk_buff *skb)
1365{
1366	struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
1367	u8 nr = PDU_SUPV_GET_Nr(pdu);
1368
1369	if (llc_circular_between(llc_sk(sk)->vS, nr, llc_sk(sk)->X))
1370		llc_conn_ac_set_vs_nr(sk, skb);
1371	return 0;
1372}
1373
1374/*
1375 * Non-standard actions; these not contained in IEEE specification; for
1376 * our own usage
1377 */
1378/**
1379 *	llc_conn_disc - removes connection from SAP list and frees it
1380 *	@sk: closed connection
1381 *	@skb: occurred event
1382 */
1383int llc_conn_disc(struct sock *sk, struct sk_buff *skb)
1384{
1385	/* FIXME: this thing seems to want to die */
1386	return 0;
1387}
1388
1389/**
1390 *	llc_conn_reset - resets connection
1391 *	@sk : reseting connection.
1392 *	@skb: occurred event.
1393 *
1394 *	Stop all timers, empty all queues and reset all flags.
1395 */
1396int llc_conn_reset(struct sock *sk, struct sk_buff *skb)
1397{
1398	llc_sk_reset(sk);
1399	return 0;
1400}
1401
1402/**
1403 *	llc_circular_between - designates that b is between a and c or not
1404 *	@a: lower bound
1405 *	@b: element to see if is between a and b
1406 *	@c: upper bound
1407 *
1408 *	This function designates that b is between a and c or not (for example,
1409 *	0 is between 127 and 1). Returns 1 if b is between a and c, 0
1410 *	otherwise.
1411 */
1412u8 llc_circular_between(u8 a, u8 b, u8 c)
1413{
1414	b = b - a;
1415	c = c - a;
1416	return b <= c;
1417}
1418
1419/**
1420 *	llc_process_tmr_ev - timer backend
1421 *	@sk: active connection
1422 *	@skb: occurred event
1423 *
1424 *	This function is called from timer callback functions. When connection
1425 *	is busy (during sending a data frame) timer expiration event must be
1426 *	queued. Otherwise this event can be sent to connection state machine.
1427 *	Queued events will process by llc_backlog_rcv function after sending
1428 *	data frame.
1429 */
1430static void llc_process_tmr_ev(struct sock *sk, struct sk_buff *skb)
1431{
1432	if (llc_sk(sk)->state == LLC_CONN_OUT_OF_SVC) {
1433		printk(KERN_WARNING "%s: timer called on closed connection\n",
1434		       __func__);
1435		kfree_skb(skb);
1436	} else {
1437		if (!sock_owned_by_user(sk))
1438			llc_conn_state_process(sk, skb);
1439		else {
1440			llc_set_backlog_type(skb, LLC_EVENT);
1441			__sk_add_backlog(sk, skb);
1442		}
1443	}
1444}
1445