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 
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 
llc_conn_ac_clear_remote_busy(struct sock * sk,struct sk_buff * skb)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 
llc_conn_ac_conn_ind(struct sock * sk,struct sk_buff * skb)61 int 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 
llc_conn_ac_conn_confirm(struct sock * sk,struct sk_buff * skb)69 int 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 
llc_conn_ac_data_confirm(struct sock * sk,struct sk_buff * skb)77 static 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 
llc_conn_ac_data_ind(struct sock * sk,struct sk_buff * skb)85 int 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 
llc_conn_ac_disc_ind(struct sock * sk,struct sk_buff * skb)91 int 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 
llc_conn_ac_disc_confirm(struct sock * sk,struct sk_buff * skb)119 int 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 
llc_conn_ac_rst_ind(struct sock * sk,struct sk_buff * skb)128 int 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 
llc_conn_ac_rst_confirm(struct sock * sk,struct sk_buff * skb)167 int 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 
llc_conn_ac_clear_remote_busy_if_f_eq_1(struct sock * sk,struct sk_buff * skb)176 int 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 
llc_conn_ac_stop_rej_tmr_if_data_flag_eq_2(struct sock * sk,struct sk_buff * skb)188 int 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 
llc_conn_ac_send_disc_cmd_p_set_x(struct sock * sk,struct sk_buff * skb)198 int 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 	}
216 out:
217 	return rc;
218 free:
219 	kfree_skb(nskb);
220 	goto out;
221 }
222 
llc_conn_ac_send_dm_rsp_f_set_p(struct sock * sk,struct sk_buff * skb)223 int 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 	}
242 out:
243 	return rc;
244 free:
245 	kfree_skb(nskb);
246 	goto out;
247 }
248 
llc_conn_ac_send_dm_rsp_f_set_1(struct sock * sk,struct sk_buff * skb)249 int 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 	}
266 out:
267 	return rc;
268 free:
269 	kfree_skb(nskb);
270 	goto out;
271 }
272 
llc_conn_ac_send_frmr_rsp_f_set_x(struct sock * sk,struct sk_buff * skb)273 int 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 	}
300 out:
301 	return rc;
302 free:
303 	kfree_skb(nskb);
304 	goto out;
305 }
306 
llc_conn_ac_resend_frmr_rsp_f_set_0(struct sock * sk,struct sk_buff * skb)307 int 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 	}
327 out:
328 	return rc;
329 free:
330 	kfree_skb(nskb);
331 	goto out;
332 }
333 
llc_conn_ac_resend_frmr_rsp_f_set_p(struct sock * sk,struct sk_buff * skb)334 int 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 	}
357 out:
358 	return rc;
359 free:
360 	kfree_skb(nskb);
361 	goto out;
362 }
363 
llc_conn_ac_send_i_cmd_p_set_1(struct sock * sk,struct sk_buff * skb)364 int 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 
llc_conn_ac_send_i_cmd_p_set_0(struct sock * sk,struct sk_buff * skb)381 static 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 
llc_conn_ac_send_i_xxx_x_set_0(struct sock * sk,struct sk_buff * skb)398 int 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 
llc_conn_ac_resend_i_xxx_x_set_0(struct sock * sk,struct sk_buff * skb)415 int 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 
llc_conn_ac_resend_i_xxx_x_set_0_or_send_rr(struct sock * sk,struct sk_buff * skb)424 int 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 
llc_conn_ac_resend_i_rsp_f_set_1(struct sock * sk,struct sk_buff * skb)453 int 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 
llc_conn_ac_send_rej_cmd_p_set_1(struct sock * sk,struct sk_buff * skb)462 int 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 	}
479 out:
480 	return rc;
481 free:
482 	kfree_skb(nskb);
483 	goto out;
484 }
485 
llc_conn_ac_send_rej_rsp_f_set_1(struct sock * sk,struct sk_buff * skb)486 int 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 	}
503 out:
504 	return rc;
505 free:
506 	kfree_skb(nskb);
507 	goto out;
508 }
509 
llc_conn_ac_send_rej_xxx_x_set_0(struct sock * sk,struct sk_buff * skb)510 int 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 	}
527 out:
528 	return rc;
529 free:
530 	kfree_skb(nskb);
531 	goto out;
532 }
533 
llc_conn_ac_send_rnr_cmd_p_set_1(struct sock * sk,struct sk_buff * skb)534 int 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 	}
551 out:
552 	return rc;
553 free:
554 	kfree_skb(nskb);
555 	goto out;
556 }
557 
llc_conn_ac_send_rnr_rsp_f_set_1(struct sock * sk,struct sk_buff * skb)558 int 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 	}
575 out:
576 	return rc;
577 free:
578 	kfree_skb(nskb);
579 	goto out;
580 }
581 
llc_conn_ac_send_rnr_xxx_x_set_0(struct sock * sk,struct sk_buff * skb)582 int 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 	}
599 out:
600 	return rc;
601 free:
602 	kfree_skb(nskb);
603 	goto out;
604 }
605 
llc_conn_ac_set_remote_busy(struct sock * sk,struct sk_buff * skb)606 int 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 
llc_conn_ac_opt_send_rnr_xxx_x_set_0(struct sock * sk,struct sk_buff * skb)618 int 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 	}
635 out:
636 	return rc;
637 free:
638 	kfree_skb(nskb);
639 	goto out;
640 }
641 
llc_conn_ac_send_rr_cmd_p_set_1(struct sock * sk,struct sk_buff * skb)642 int 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 	}
659 out:
660 	return rc;
661 free:
662 	kfree_skb(nskb);
663 	goto out;
664 }
665 
llc_conn_ac_send_rr_rsp_f_set_1(struct sock * sk,struct sk_buff * skb)666 int 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 	}
684 out:
685 	return rc;
686 free:
687 	kfree_skb(nskb);
688 	goto out;
689 }
690 
llc_conn_ac_send_ack_rsp_f_set_1(struct sock * sk,struct sk_buff * skb)691 int 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 	}
708 out:
709 	return rc;
710 free:
711 	kfree_skb(nskb);
712 	goto out;
713 }
714 
llc_conn_ac_send_rr_xxx_x_set_0(struct sock * sk,struct sk_buff * skb)715 int 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 	}
732 out:
733 	return rc;
734 free:
735 	kfree_skb(nskb);
736 	goto out;
737 }
738 
llc_conn_ac_send_ack_xxx_x_set_0(struct sock * sk,struct sk_buff * skb)739 int 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 	}
756 out:
757 	return rc;
758 free:
759 	kfree_skb(nskb);
760 	goto out;
761 }
762 
llc_conn_set_p_flag(struct sock * sk,u8 value)763 void 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 
llc_conn_ac_send_sabme_cmd_p_set_x(struct sock * sk,struct sk_buff * skb)773 int 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 	}
794 out:
795 	return rc;
796 free:
797 	kfree_skb(nskb);
798 	goto out;
799 }
800 
llc_conn_ac_send_ua_rsp_f_set_p(struct sock * sk,struct sk_buff * skb)801 int 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 	}
821 out:
822 	return rc;
823 free:
824 	kfree_skb(nskb);
825 	goto out;
826 }
827 
llc_conn_ac_set_s_flag_0(struct sock * sk,struct sk_buff * skb)828 int 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 
llc_conn_ac_set_s_flag_1(struct sock * sk,struct sk_buff * skb)834 int 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 
llc_conn_ac_start_p_timer(struct sock * sk,struct sk_buff * skb)840 int 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  */
llc_conn_ac_send_ack_if_needed(struct sock * sk,struct sk_buff * skb)860 int 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  */
llc_conn_ac_rst_sendack_flag(struct sock * sk,struct sk_buff * skb)891 int 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  */
llc_conn_ac_send_i_rsp_f_set_ackpf(struct sock * sk,struct sk_buff * skb)907 static 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  */
llc_conn_ac_send_i_as_ack(struct sock * sk,struct sk_buff * skb)935 int 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  */
llc_conn_ac_send_rr_rsp_f_set_ackpf(struct sock * sk,struct sk_buff * skb)958 static 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 	}
976 out:
977 	return rc;
978 free:
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  */
llc_conn_ac_inc_npta_value(struct sock * sk,struct sk_buff * skb)993 static 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  */
llc_conn_ac_adjust_npta_by_rr(struct sock * sk,struct sk_buff * skb)1016 int 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  */
llc_conn_ac_adjust_npta_by_rnr(struct sock * sk,struct sk_buff * skb)1042 int 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  */
llc_conn_ac_dec_tx_win_size(struct sock * sk,struct sk_buff * skb)1067 int 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  */
llc_conn_ac_inc_tx_win_size(struct sock * sk,struct sk_buff * skb)1087 int 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 
llc_conn_ac_stop_all_timers(struct sock * sk,struct sk_buff * skb)1097 int 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 
llc_conn_ac_stop_other_timers(struct sock * sk,struct sk_buff * skb)1110 int 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 
llc_conn_ac_start_ack_timer(struct sock * sk,struct sk_buff * skb)1122 int 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 
llc_conn_ac_start_rej_timer(struct sock * sk,struct sk_buff * skb)1130 int 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 
llc_conn_ac_start_ack_tmr_if_not_running(struct sock * sk,struct sk_buff * skb)1139 int 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 
llc_conn_ac_stop_ack_timer(struct sock * sk,struct sk_buff * skb)1150 int 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 
llc_conn_ac_stop_p_timer(struct sock * sk,struct sk_buff * skb)1156 int 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 
llc_conn_ac_stop_rej_timer(struct sock * sk,struct sk_buff * skb)1165 int 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 
llc_conn_ac_upd_nr_received(struct sock * sk,struct sk_buff * skb)1171 int 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 
llc_conn_ac_upd_p_flag(struct sock * sk,struct sk_buff * skb)1207 int 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 
llc_conn_ac_set_data_flag_2(struct sock * sk,struct sk_buff * skb)1223 int 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 
llc_conn_ac_set_data_flag_0(struct sock * sk,struct sk_buff * skb)1229 int 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 
llc_conn_ac_set_data_flag_1(struct sock * sk,struct sk_buff * skb)1235 int 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 
llc_conn_ac_set_data_flag_1_if_data_flag_eq_0(struct sock * sk,struct sk_buff * skb)1241 int 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 
llc_conn_ac_set_p_flag_0(struct sock * sk,struct sk_buff * skb)1249 int 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 
llc_conn_ac_set_p_flag_1(struct sock * sk,struct sk_buff * skb)1255 static 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 
llc_conn_ac_set_remote_busy_0(struct sock * sk,struct sk_buff * skb)1261 int 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 
llc_conn_ac_set_cause_flag_0(struct sock * sk,struct sk_buff * skb)1267 int 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 
llc_conn_ac_set_cause_flag_1(struct sock * sk,struct sk_buff * skb)1273 int 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 
llc_conn_ac_set_retry_cnt_0(struct sock * sk,struct sk_buff * skb)1279 int 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 
llc_conn_ac_inc_retry_cnt_by_1(struct sock * sk,struct sk_buff * skb)1285 int 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 
llc_conn_ac_set_vr_0(struct sock * sk,struct sk_buff * skb)1291 int 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 
llc_conn_ac_inc_vr_by_1(struct sock * sk,struct sk_buff * skb)1297 int 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 
llc_conn_ac_set_vs_0(struct sock * sk,struct sk_buff * skb)1303 int 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 
llc_conn_ac_set_vs_nr(struct sock * sk,struct sk_buff * skb)1309 int 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 
llc_conn_ac_inc_vs_by_1(struct sock * sk,struct sk_buff * skb)1315 static 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 
llc_conn_tmr_common_cb(unsigned long timeout_data,u8 type)1321 static 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 
llc_conn_pf_cycle_tmr_cb(unsigned long timeout_data)1337 void 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 
llc_conn_busy_tmr_cb(unsigned long timeout_data)1342 void 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 
llc_conn_ack_tmr_cb(unsigned long timeout_data)1347 void 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 
llc_conn_rej_tmr_cb(unsigned long timeout_data)1352 void 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 
llc_conn_ac_rst_vs(struct sock * sk,struct sk_buff * skb)1357 int 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 
llc_conn_ac_upd_vs(struct sock * sk,struct sk_buff * skb)1364 int 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  */
llc_conn_disc(struct sock * sk,struct sk_buff * skb)1383 int 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  */
llc_conn_reset(struct sock * sk,struct sk_buff * skb)1396 int 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  */
llc_circular_between(u8 a,u8 b,u8 c)1412 u8 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  */
llc_process_tmr_ev(struct sock * sk,struct sk_buff * skb)1430 static 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