1 /*
2  * llc_c_ev.c - Connection component state transition event qualifiers
3  *
4  * A 'state' consists of a number of possible event matching functions,
5  * the actions associated with each being executed when that event is
6  * matched; a 'state machine' accepts events in a serial fashion from an
7  * event queue. Each event is passed to each successive event matching
8  * function until a match is made (the event matching function returns
9  * success, or '0') or the list of event matching functions is exhausted.
10  * If a match is made, the actions associated with the event are executed
11  * and the state is changed to that event's transition state. Before some
12  * events are recognized, even after a match has been made, a certain
13  * number of 'event qualifier' functions must also be executed. If these
14  * all execute successfully, then the event is finally executed.
15  *
16  * These event functions must return 0 for success, to show a matched
17  * event, of 1 if the event does not match. Event qualifier functions
18  * must return a 0 for success or a non-zero for failure. Each function
19  * is simply responsible for verifying one single thing and returning
20  * either a success or failure.
21  *
22  * All of followed event functions are described in 802.2 LLC Protocol
23  * standard document except two functions that we added that will explain
24  * in their comments, at below.
25  *
26  * Copyright (c) 1997 by Procom Technology, Inc.
27  * 		 2001-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
28  *
29  * This program can be redistributed or modified under the terms of the
30  * GNU General Public License as published by the Free Software Foundation.
31  * This program is distributed without any warranty or implied warranty
32  * of merchantability or fitness for a particular purpose.
33  *
34  * See the GNU General Public License for more details.
35  */
36 #include <linux/netdevice.h>
37 #include <net/llc_conn.h>
38 #include <net/llc_sap.h>
39 #include <net/sock.h>
40 #include <net/llc_c_ac.h>
41 #include <net/llc_c_ev.h>
42 #include <net/llc_pdu.h>
43 
44 #if 1
45 #define dprintk(args...) printk(KERN_DEBUG args)
46 #else
47 #define dprintk(args...)
48 #endif
49 
50 /**
51  *	llc_util_ns_inside_rx_window - check if sequence number is in rx window
52  *	@ns: sequence number of received pdu.
53  *	@vr: sequence number which receiver expects to receive.
54  *	@rw: receive window size of receiver.
55  *
56  *	Checks if sequence number of received PDU is in range of receive
57  *	window. Returns 0 for success, 1 otherwise
58  */
llc_util_ns_inside_rx_window(u8 ns,u8 vr,u8 rw)59 static u16 llc_util_ns_inside_rx_window(u8 ns, u8 vr, u8 rw)
60 {
61 	return !llc_circular_between(vr, ns,
62 				     (vr + rw - 1) % LLC_2_SEQ_NBR_MODULO);
63 }
64 
65 /**
66  *	llc_util_nr_inside_tx_window - check if sequence number is in tx window
67  *	@sk: current connection.
68  *	@nr: N(R) of received PDU.
69  *
70  *	This routine checks if N(R) of received PDU is in range of transmit
71  *	window; on the other hand checks if received PDU acknowledges some
72  *	outstanding PDUs that are in transmit window. Returns 0 for success, 1
73  *	otherwise.
74  */
llc_util_nr_inside_tx_window(struct sock * sk,u8 nr)75 static u16 llc_util_nr_inside_tx_window(struct sock *sk, u8 nr)
76 {
77 	u8 nr1, nr2;
78 	struct sk_buff *skb;
79 	struct llc_pdu_sn *pdu;
80 	struct llc_sock *llc = llc_sk(sk);
81 	int rc = 0;
82 
83 	if (llc->dev->flags & IFF_LOOPBACK)
84 		goto out;
85 	rc = 1;
86 	if (skb_queue_empty(&llc->pdu_unack_q))
87 		goto out;
88 	skb = skb_peek(&llc->pdu_unack_q);
89 	pdu = llc_pdu_sn_hdr(skb);
90 	nr1 = LLC_I_GET_NS(pdu);
91 	skb = skb_peek_tail(&llc->pdu_unack_q);
92 	pdu = llc_pdu_sn_hdr(skb);
93 	nr2 = LLC_I_GET_NS(pdu);
94 	rc = !llc_circular_between(nr1, nr, (nr2 + 1) % LLC_2_SEQ_NBR_MODULO);
95 out:
96 	return rc;
97 }
98 
llc_conn_ev_conn_req(struct sock * sk,struct sk_buff * skb)99 int llc_conn_ev_conn_req(struct sock *sk, struct sk_buff *skb)
100 {
101 	const struct llc_conn_state_ev *ev = llc_conn_ev(skb);
102 
103 	return ev->prim == LLC_CONN_PRIM &&
104 	       ev->prim_type == LLC_PRIM_TYPE_REQ ? 0 : 1;
105 }
106 
llc_conn_ev_data_req(struct sock * sk,struct sk_buff * skb)107 int llc_conn_ev_data_req(struct sock *sk, struct sk_buff *skb)
108 {
109 	const struct llc_conn_state_ev *ev = llc_conn_ev(skb);
110 
111 	return ev->prim == LLC_DATA_PRIM &&
112 	       ev->prim_type == LLC_PRIM_TYPE_REQ ? 0 : 1;
113 }
114 
llc_conn_ev_disc_req(struct sock * sk,struct sk_buff * skb)115 int llc_conn_ev_disc_req(struct sock *sk, struct sk_buff *skb)
116 {
117 	const struct llc_conn_state_ev *ev = llc_conn_ev(skb);
118 
119 	return ev->prim == LLC_DISC_PRIM &&
120 	       ev->prim_type == LLC_PRIM_TYPE_REQ ? 0 : 1;
121 }
122 
llc_conn_ev_rst_req(struct sock * sk,struct sk_buff * skb)123 int llc_conn_ev_rst_req(struct sock *sk, struct sk_buff *skb)
124 {
125 	const struct llc_conn_state_ev *ev = llc_conn_ev(skb);
126 
127 	return ev->prim == LLC_RESET_PRIM &&
128 	       ev->prim_type == LLC_PRIM_TYPE_REQ ? 0 : 1;
129 }
130 
llc_conn_ev_local_busy_detected(struct sock * sk,struct sk_buff * skb)131 int llc_conn_ev_local_busy_detected(struct sock *sk, struct sk_buff *skb)
132 {
133 	const struct llc_conn_state_ev *ev = llc_conn_ev(skb);
134 
135 	return ev->type == LLC_CONN_EV_TYPE_SIMPLE &&
136 	       ev->prim_type == LLC_CONN_EV_LOCAL_BUSY_DETECTED ? 0 : 1;
137 }
138 
llc_conn_ev_local_busy_cleared(struct sock * sk,struct sk_buff * skb)139 int llc_conn_ev_local_busy_cleared(struct sock *sk, struct sk_buff *skb)
140 {
141 	const struct llc_conn_state_ev *ev = llc_conn_ev(skb);
142 
143 	return ev->type == LLC_CONN_EV_TYPE_SIMPLE &&
144 	       ev->prim_type == LLC_CONN_EV_LOCAL_BUSY_CLEARED ? 0 : 1;
145 }
146 
llc_conn_ev_rx_bad_pdu(struct sock * sk,struct sk_buff * skb)147 int llc_conn_ev_rx_bad_pdu(struct sock *sk, struct sk_buff *skb)
148 {
149 	return 1;
150 }
151 
llc_conn_ev_rx_disc_cmd_pbit_set_x(struct sock * sk,struct sk_buff * skb)152 int llc_conn_ev_rx_disc_cmd_pbit_set_x(struct sock *sk, struct sk_buff *skb)
153 {
154 	const struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
155 
156 	return LLC_PDU_IS_CMD(pdu) && LLC_PDU_TYPE_IS_U(pdu) &&
157 	       LLC_U_PDU_CMD(pdu) == LLC_2_PDU_CMD_DISC ? 0 : 1;
158 }
159 
llc_conn_ev_rx_dm_rsp_fbit_set_x(struct sock * sk,struct sk_buff * skb)160 int llc_conn_ev_rx_dm_rsp_fbit_set_x(struct sock *sk, struct sk_buff *skb)
161 {
162 	const struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
163 
164 	return LLC_PDU_IS_RSP(pdu) && LLC_PDU_TYPE_IS_U(pdu) &&
165 	       LLC_U_PDU_RSP(pdu) == LLC_2_PDU_RSP_DM ? 0 : 1;
166 }
167 
llc_conn_ev_rx_frmr_rsp_fbit_set_x(struct sock * sk,struct sk_buff * skb)168 int llc_conn_ev_rx_frmr_rsp_fbit_set_x(struct sock *sk, struct sk_buff *skb)
169 {
170 	const struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
171 
172 	return LLC_PDU_IS_RSP(pdu) && LLC_PDU_TYPE_IS_U(pdu) &&
173 	       LLC_U_PDU_RSP(pdu) == LLC_2_PDU_RSP_FRMR ? 0 : 1;
174 }
175 
llc_conn_ev_rx_i_cmd_pbit_set_0(struct sock * sk,struct sk_buff * skb)176 int llc_conn_ev_rx_i_cmd_pbit_set_0(struct sock *sk, struct sk_buff *skb)
177 {
178 	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
179 
180 	return llc_conn_space(sk, skb) &&
181 	       LLC_PDU_IS_CMD(pdu) && LLC_PDU_TYPE_IS_I(pdu) &&
182 	       LLC_I_PF_IS_0(pdu) &&
183 	       LLC_I_GET_NS(pdu) == llc_sk(sk)->vR ? 0 : 1;
184 }
185 
llc_conn_ev_rx_i_cmd_pbit_set_1(struct sock * sk,struct sk_buff * skb)186 int llc_conn_ev_rx_i_cmd_pbit_set_1(struct sock *sk, struct sk_buff *skb)
187 {
188 	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
189 
190 	return llc_conn_space(sk, skb) &&
191 	       LLC_PDU_IS_CMD(pdu) && LLC_PDU_TYPE_IS_I(pdu) &&
192 	       LLC_I_PF_IS_1(pdu) &&
193 	       LLC_I_GET_NS(pdu) == llc_sk(sk)->vR ? 0 : 1;
194 }
195 
llc_conn_ev_rx_i_cmd_pbit_set_0_unexpd_ns(struct sock * sk,struct sk_buff * skb)196 int llc_conn_ev_rx_i_cmd_pbit_set_0_unexpd_ns(struct sock *sk,
197 					      struct sk_buff *skb)
198 {
199 	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
200 	const u8 vr = llc_sk(sk)->vR;
201 	const u8 ns = LLC_I_GET_NS(pdu);
202 
203 	return LLC_PDU_IS_CMD(pdu) && LLC_PDU_TYPE_IS_I(pdu) &&
204 	       LLC_I_PF_IS_0(pdu) && ns != vr &&
205 	       !llc_util_ns_inside_rx_window(ns, vr, llc_sk(sk)->rw) ? 0 : 1;
206 }
207 
llc_conn_ev_rx_i_cmd_pbit_set_1_unexpd_ns(struct sock * sk,struct sk_buff * skb)208 int llc_conn_ev_rx_i_cmd_pbit_set_1_unexpd_ns(struct sock *sk,
209 					      struct sk_buff *skb)
210 {
211 	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
212 	const u8 vr = llc_sk(sk)->vR;
213 	const u8 ns = LLC_I_GET_NS(pdu);
214 
215 	return LLC_PDU_IS_CMD(pdu) && LLC_PDU_TYPE_IS_I(pdu) &&
216 	       LLC_I_PF_IS_1(pdu) && ns != vr &&
217 	       !llc_util_ns_inside_rx_window(ns, vr, llc_sk(sk)->rw) ? 0 : 1;
218 }
219 
llc_conn_ev_rx_i_cmd_pbit_set_x_inval_ns(struct sock * sk,struct sk_buff * skb)220 int llc_conn_ev_rx_i_cmd_pbit_set_x_inval_ns(struct sock *sk,
221 					     struct sk_buff *skb)
222 {
223 	const struct llc_pdu_sn * pdu = llc_pdu_sn_hdr(skb);
224 	const u8 vr = llc_sk(sk)->vR;
225 	const u8 ns = LLC_I_GET_NS(pdu);
226 	const u16 rc = LLC_PDU_IS_CMD(pdu) && LLC_PDU_TYPE_IS_I(pdu) &&
227 		ns != vr &&
228 		 llc_util_ns_inside_rx_window(ns, vr, llc_sk(sk)->rw) ? 0 : 1;
229 	if (!rc)
230 		dprintk("%s: matched, state=%d, ns=%d, vr=%d\n",
231 			__func__, llc_sk(sk)->state, ns, vr);
232 	return rc;
233 }
234 
llc_conn_ev_rx_i_rsp_fbit_set_0(struct sock * sk,struct sk_buff * skb)235 int llc_conn_ev_rx_i_rsp_fbit_set_0(struct sock *sk, struct sk_buff *skb)
236 {
237 	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
238 
239 	return llc_conn_space(sk, skb) &&
240 	       LLC_PDU_IS_RSP(pdu) && LLC_PDU_TYPE_IS_I(pdu) &&
241 	       LLC_I_PF_IS_0(pdu) &&
242 	       LLC_I_GET_NS(pdu) == llc_sk(sk)->vR ? 0 : 1;
243 }
244 
llc_conn_ev_rx_i_rsp_fbit_set_1(struct sock * sk,struct sk_buff * skb)245 int llc_conn_ev_rx_i_rsp_fbit_set_1(struct sock *sk, struct sk_buff *skb)
246 {
247 	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
248 
249 	return LLC_PDU_IS_RSP(pdu) && LLC_PDU_TYPE_IS_I(pdu) &&
250 	       LLC_I_PF_IS_1(pdu) &&
251 	       LLC_I_GET_NS(pdu) == llc_sk(sk)->vR ? 0 : 1;
252 }
253 
llc_conn_ev_rx_i_rsp_fbit_set_x(struct sock * sk,struct sk_buff * skb)254 int llc_conn_ev_rx_i_rsp_fbit_set_x(struct sock *sk, struct sk_buff *skb)
255 {
256 	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
257 
258 	return llc_conn_space(sk, skb) &&
259 	       LLC_PDU_IS_RSP(pdu) && LLC_PDU_TYPE_IS_I(pdu) &&
260 	       LLC_I_GET_NS(pdu) == llc_sk(sk)->vR ? 0 : 1;
261 }
262 
llc_conn_ev_rx_i_rsp_fbit_set_0_unexpd_ns(struct sock * sk,struct sk_buff * skb)263 int llc_conn_ev_rx_i_rsp_fbit_set_0_unexpd_ns(struct sock *sk,
264 					      struct sk_buff *skb)
265 {
266 	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
267 	const u8 vr = llc_sk(sk)->vR;
268 	const u8 ns = LLC_I_GET_NS(pdu);
269 
270 	return LLC_PDU_IS_RSP(pdu) && LLC_PDU_TYPE_IS_I(pdu) &&
271 	       LLC_I_PF_IS_0(pdu) && ns != vr &&
272 	       !llc_util_ns_inside_rx_window(ns, vr, llc_sk(sk)->rw) ? 0 : 1;
273 }
274 
llc_conn_ev_rx_i_rsp_fbit_set_1_unexpd_ns(struct sock * sk,struct sk_buff * skb)275 int llc_conn_ev_rx_i_rsp_fbit_set_1_unexpd_ns(struct sock *sk,
276 					      struct sk_buff *skb)
277 {
278 	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
279 	const u8 vr = llc_sk(sk)->vR;
280 	const u8 ns = LLC_I_GET_NS(pdu);
281 
282 	return LLC_PDU_IS_RSP(pdu) && LLC_PDU_TYPE_IS_I(pdu) &&
283 	       LLC_I_PF_IS_1(pdu) && ns != vr &&
284 	       !llc_util_ns_inside_rx_window(ns, vr, llc_sk(sk)->rw) ? 0 : 1;
285 }
286 
llc_conn_ev_rx_i_rsp_fbit_set_x_unexpd_ns(struct sock * sk,struct sk_buff * skb)287 int llc_conn_ev_rx_i_rsp_fbit_set_x_unexpd_ns(struct sock *sk,
288 					      struct sk_buff *skb)
289 {
290 	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
291 	const u8 vr = llc_sk(sk)->vR;
292 	const u8 ns = LLC_I_GET_NS(pdu);
293 
294 	return LLC_PDU_IS_RSP(pdu) && LLC_PDU_TYPE_IS_I(pdu) && ns != vr &&
295 	       !llc_util_ns_inside_rx_window(ns, vr, llc_sk(sk)->rw) ? 0 : 1;
296 }
297 
llc_conn_ev_rx_i_rsp_fbit_set_x_inval_ns(struct sock * sk,struct sk_buff * skb)298 int llc_conn_ev_rx_i_rsp_fbit_set_x_inval_ns(struct sock *sk,
299 					     struct sk_buff *skb)
300 {
301 	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
302 	const u8 vr = llc_sk(sk)->vR;
303 	const u8 ns = LLC_I_GET_NS(pdu);
304 	const u16 rc = LLC_PDU_IS_RSP(pdu) && LLC_PDU_TYPE_IS_I(pdu) &&
305 		ns != vr &&
306 		 llc_util_ns_inside_rx_window(ns, vr, llc_sk(sk)->rw) ? 0 : 1;
307 	if (!rc)
308 		dprintk("%s: matched, state=%d, ns=%d, vr=%d\n",
309 			__func__, llc_sk(sk)->state, ns, vr);
310 	return rc;
311 }
312 
llc_conn_ev_rx_rej_cmd_pbit_set_0(struct sock * sk,struct sk_buff * skb)313 int llc_conn_ev_rx_rej_cmd_pbit_set_0(struct sock *sk, struct sk_buff *skb)
314 {
315 	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
316 
317 	return LLC_PDU_IS_CMD(pdu) && LLC_PDU_TYPE_IS_S(pdu) &&
318 	       LLC_S_PF_IS_0(pdu) &&
319 	       LLC_S_PDU_CMD(pdu) == LLC_2_PDU_CMD_REJ ? 0 : 1;
320 }
321 
llc_conn_ev_rx_rej_cmd_pbit_set_1(struct sock * sk,struct sk_buff * skb)322 int llc_conn_ev_rx_rej_cmd_pbit_set_1(struct sock *sk, struct sk_buff *skb)
323 {
324 	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
325 
326 	return LLC_PDU_IS_CMD(pdu) && LLC_PDU_TYPE_IS_S(pdu) &&
327 	       LLC_S_PF_IS_1(pdu) &&
328 	       LLC_S_PDU_CMD(pdu) == LLC_2_PDU_CMD_REJ ? 0 : 1;
329 }
330 
llc_conn_ev_rx_rej_rsp_fbit_set_0(struct sock * sk,struct sk_buff * skb)331 int llc_conn_ev_rx_rej_rsp_fbit_set_0(struct sock *sk, struct sk_buff *skb)
332 {
333 	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
334 
335 	return LLC_PDU_IS_RSP(pdu) && LLC_PDU_TYPE_IS_S(pdu) &&
336 	       LLC_S_PF_IS_0(pdu) &&
337 	       LLC_S_PDU_RSP(pdu) == LLC_2_PDU_RSP_REJ ? 0 : 1;
338 }
339 
llc_conn_ev_rx_rej_rsp_fbit_set_1(struct sock * sk,struct sk_buff * skb)340 int llc_conn_ev_rx_rej_rsp_fbit_set_1(struct sock *sk, struct sk_buff *skb)
341 {
342 	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
343 
344 	return LLC_PDU_IS_RSP(pdu) && LLC_PDU_TYPE_IS_S(pdu) &&
345 	       LLC_S_PF_IS_1(pdu) &&
346 	       LLC_S_PDU_RSP(pdu) == LLC_2_PDU_RSP_REJ ? 0 : 1;
347 }
348 
llc_conn_ev_rx_rej_rsp_fbit_set_x(struct sock * sk,struct sk_buff * skb)349 int llc_conn_ev_rx_rej_rsp_fbit_set_x(struct sock *sk, struct sk_buff *skb)
350 {
351 	const struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
352 
353 	return LLC_PDU_IS_RSP(pdu) && LLC_PDU_TYPE_IS_S(pdu) &&
354 	       LLC_S_PDU_RSP(pdu) == LLC_2_PDU_RSP_REJ ? 0 : 1;
355 }
356 
llc_conn_ev_rx_rnr_cmd_pbit_set_0(struct sock * sk,struct sk_buff * skb)357 int llc_conn_ev_rx_rnr_cmd_pbit_set_0(struct sock *sk, struct sk_buff *skb)
358 {
359 	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
360 
361 	return LLC_PDU_IS_CMD(pdu) && LLC_PDU_TYPE_IS_S(pdu) &&
362 	       LLC_S_PF_IS_0(pdu) &&
363 	       LLC_S_PDU_CMD(pdu) == LLC_2_PDU_CMD_RNR ? 0 : 1;
364 }
365 
llc_conn_ev_rx_rnr_cmd_pbit_set_1(struct sock * sk,struct sk_buff * skb)366 int llc_conn_ev_rx_rnr_cmd_pbit_set_1(struct sock *sk, struct sk_buff *skb)
367 {
368 	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
369 
370 	return LLC_PDU_IS_CMD(pdu) && LLC_PDU_TYPE_IS_S(pdu) &&
371 	       LLC_S_PF_IS_1(pdu) &&
372 	       LLC_S_PDU_CMD(pdu) == LLC_2_PDU_CMD_RNR ? 0 : 1;
373 }
374 
llc_conn_ev_rx_rnr_rsp_fbit_set_0(struct sock * sk,struct sk_buff * skb)375 int llc_conn_ev_rx_rnr_rsp_fbit_set_0(struct sock *sk, struct sk_buff *skb)
376 {
377 	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
378 
379 	return LLC_PDU_IS_RSP(pdu) && LLC_PDU_TYPE_IS_S(pdu) &&
380 	       LLC_S_PF_IS_0(pdu) &&
381 	       LLC_S_PDU_RSP(pdu) == LLC_2_PDU_RSP_RNR ? 0 : 1;
382 }
383 
llc_conn_ev_rx_rnr_rsp_fbit_set_1(struct sock * sk,struct sk_buff * skb)384 int llc_conn_ev_rx_rnr_rsp_fbit_set_1(struct sock *sk, struct sk_buff *skb)
385 {
386 	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
387 
388 	return LLC_PDU_IS_RSP(pdu) && LLC_PDU_TYPE_IS_S(pdu) &&
389 	       LLC_S_PF_IS_1(pdu) &&
390 	       LLC_S_PDU_RSP(pdu) == LLC_2_PDU_RSP_RNR ? 0 : 1;
391 }
392 
llc_conn_ev_rx_rr_cmd_pbit_set_0(struct sock * sk,struct sk_buff * skb)393 int llc_conn_ev_rx_rr_cmd_pbit_set_0(struct sock *sk, struct sk_buff *skb)
394 {
395 	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
396 
397 	return LLC_PDU_IS_CMD(pdu) && LLC_PDU_TYPE_IS_S(pdu) &&
398 	       LLC_S_PF_IS_0(pdu) &&
399 	       LLC_S_PDU_CMD(pdu) == LLC_2_PDU_CMD_RR ? 0 : 1;
400 }
401 
llc_conn_ev_rx_rr_cmd_pbit_set_1(struct sock * sk,struct sk_buff * skb)402 int llc_conn_ev_rx_rr_cmd_pbit_set_1(struct sock *sk, struct sk_buff *skb)
403 {
404 	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
405 
406 	return LLC_PDU_IS_CMD(pdu) && LLC_PDU_TYPE_IS_S(pdu) &&
407 	       LLC_S_PF_IS_1(pdu) &&
408 	       LLC_S_PDU_CMD(pdu) == LLC_2_PDU_CMD_RR ? 0 : 1;
409 }
410 
llc_conn_ev_rx_rr_rsp_fbit_set_0(struct sock * sk,struct sk_buff * skb)411 int llc_conn_ev_rx_rr_rsp_fbit_set_0(struct sock *sk, struct sk_buff *skb)
412 {
413 	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
414 
415 	return llc_conn_space(sk, skb) &&
416 	       LLC_PDU_IS_RSP(pdu) && LLC_PDU_TYPE_IS_S(pdu) &&
417 	       LLC_S_PF_IS_0(pdu) &&
418 	       LLC_S_PDU_RSP(pdu) == LLC_2_PDU_RSP_RR ? 0 : 1;
419 }
420 
llc_conn_ev_rx_rr_rsp_fbit_set_1(struct sock * sk,struct sk_buff * skb)421 int llc_conn_ev_rx_rr_rsp_fbit_set_1(struct sock *sk, struct sk_buff *skb)
422 {
423 	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
424 
425 	return llc_conn_space(sk, skb) &&
426 	       LLC_PDU_IS_RSP(pdu) && LLC_PDU_TYPE_IS_S(pdu) &&
427 	       LLC_S_PF_IS_1(pdu) &&
428 	       LLC_S_PDU_RSP(pdu) == LLC_2_PDU_RSP_RR ? 0 : 1;
429 }
430 
llc_conn_ev_rx_sabme_cmd_pbit_set_x(struct sock * sk,struct sk_buff * skb)431 int llc_conn_ev_rx_sabme_cmd_pbit_set_x(struct sock *sk, struct sk_buff *skb)
432 {
433 	const struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
434 
435 	return LLC_PDU_IS_CMD(pdu) && LLC_PDU_TYPE_IS_U(pdu) &&
436 	       LLC_U_PDU_CMD(pdu) == LLC_2_PDU_CMD_SABME ? 0 : 1;
437 }
438 
llc_conn_ev_rx_ua_rsp_fbit_set_x(struct sock * sk,struct sk_buff * skb)439 int llc_conn_ev_rx_ua_rsp_fbit_set_x(struct sock *sk, struct sk_buff *skb)
440 {
441 	struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
442 
443 	return LLC_PDU_IS_RSP(pdu) && LLC_PDU_TYPE_IS_U(pdu) &&
444 	       LLC_U_PDU_RSP(pdu) == LLC_2_PDU_RSP_UA ? 0 : 1;
445 }
446 
llc_conn_ev_rx_xxx_cmd_pbit_set_1(struct sock * sk,struct sk_buff * skb)447 int llc_conn_ev_rx_xxx_cmd_pbit_set_1(struct sock *sk, struct sk_buff *skb)
448 {
449 	u16 rc = 1;
450 	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
451 
452 	if (LLC_PDU_IS_CMD(pdu)) {
453 		if (LLC_PDU_TYPE_IS_I(pdu) || LLC_PDU_TYPE_IS_S(pdu)) {
454 			if (LLC_I_PF_IS_1(pdu))
455 				rc = 0;
456 		} else if (LLC_PDU_TYPE_IS_U(pdu) && LLC_U_PF_IS_1(pdu))
457 			rc = 0;
458 	}
459 	return rc;
460 }
461 
llc_conn_ev_rx_xxx_cmd_pbit_set_x(struct sock * sk,struct sk_buff * skb)462 int llc_conn_ev_rx_xxx_cmd_pbit_set_x(struct sock *sk, struct sk_buff *skb)
463 {
464 	u16 rc = 1;
465 	const struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
466 
467 	if (LLC_PDU_IS_CMD(pdu)) {
468 		if (LLC_PDU_TYPE_IS_I(pdu) || LLC_PDU_TYPE_IS_S(pdu))
469 			rc = 0;
470 		else if (LLC_PDU_TYPE_IS_U(pdu))
471 			switch (LLC_U_PDU_CMD(pdu)) {
472 			case LLC_2_PDU_CMD_SABME:
473 			case LLC_2_PDU_CMD_DISC:
474 				rc = 0;
475 				break;
476 			}
477 	}
478 	return rc;
479 }
480 
llc_conn_ev_rx_xxx_rsp_fbit_set_x(struct sock * sk,struct sk_buff * skb)481 int llc_conn_ev_rx_xxx_rsp_fbit_set_x(struct sock *sk, struct sk_buff *skb)
482 {
483 	u16 rc = 1;
484 	const struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
485 
486 	if (LLC_PDU_IS_RSP(pdu)) {
487 		if (LLC_PDU_TYPE_IS_I(pdu) || LLC_PDU_TYPE_IS_S(pdu))
488 			rc = 0;
489 		else if (LLC_PDU_TYPE_IS_U(pdu))
490 			switch (LLC_U_PDU_RSP(pdu)) {
491 			case LLC_2_PDU_RSP_UA:
492 			case LLC_2_PDU_RSP_DM:
493 			case LLC_2_PDU_RSP_FRMR:
494 				rc = 0;
495 				break;
496 			}
497 	}
498 
499 	return rc;
500 }
501 
llc_conn_ev_rx_zzz_cmd_pbit_set_x_inval_nr(struct sock * sk,struct sk_buff * skb)502 int llc_conn_ev_rx_zzz_cmd_pbit_set_x_inval_nr(struct sock *sk,
503 					       struct sk_buff *skb)
504 {
505 	u16 rc = 1;
506 	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
507 	const u8 vs = llc_sk(sk)->vS;
508 	const u8 nr = LLC_I_GET_NR(pdu);
509 
510 	if (LLC_PDU_IS_CMD(pdu) &&
511 	    (LLC_PDU_TYPE_IS_I(pdu) || LLC_PDU_TYPE_IS_S(pdu)) &&
512 	    nr != vs && llc_util_nr_inside_tx_window(sk, nr)) {
513 		dprintk("%s: matched, state=%d, vs=%d, nr=%d\n",
514 			__func__, llc_sk(sk)->state, vs, nr);
515 		rc = 0;
516 	}
517 	return rc;
518 }
519 
llc_conn_ev_rx_zzz_rsp_fbit_set_x_inval_nr(struct sock * sk,struct sk_buff * skb)520 int llc_conn_ev_rx_zzz_rsp_fbit_set_x_inval_nr(struct sock *sk,
521 					       struct sk_buff *skb)
522 {
523 	u16 rc = 1;
524 	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
525 	const u8 vs = llc_sk(sk)->vS;
526 	const u8 nr = LLC_I_GET_NR(pdu);
527 
528 	if (LLC_PDU_IS_RSP(pdu) &&
529 	    (LLC_PDU_TYPE_IS_I(pdu) || LLC_PDU_TYPE_IS_S(pdu)) &&
530 	    nr != vs && llc_util_nr_inside_tx_window(sk, nr)) {
531 		rc = 0;
532 		dprintk("%s: matched, state=%d, vs=%d, nr=%d\n",
533 			__func__, llc_sk(sk)->state, vs, nr);
534 	}
535 	return rc;
536 }
537 
llc_conn_ev_rx_any_frame(struct sock * sk,struct sk_buff * skb)538 int llc_conn_ev_rx_any_frame(struct sock *sk, struct sk_buff *skb)
539 {
540 	return 0;
541 }
542 
llc_conn_ev_p_tmr_exp(struct sock * sk,struct sk_buff * skb)543 int llc_conn_ev_p_tmr_exp(struct sock *sk, struct sk_buff *skb)
544 {
545 	const struct llc_conn_state_ev *ev = llc_conn_ev(skb);
546 
547 	return ev->type != LLC_CONN_EV_TYPE_P_TMR;
548 }
549 
llc_conn_ev_ack_tmr_exp(struct sock * sk,struct sk_buff * skb)550 int llc_conn_ev_ack_tmr_exp(struct sock *sk, struct sk_buff *skb)
551 {
552 	const struct llc_conn_state_ev *ev = llc_conn_ev(skb);
553 
554 	return ev->type != LLC_CONN_EV_TYPE_ACK_TMR;
555 }
556 
llc_conn_ev_rej_tmr_exp(struct sock * sk,struct sk_buff * skb)557 int llc_conn_ev_rej_tmr_exp(struct sock *sk, struct sk_buff *skb)
558 {
559 	const struct llc_conn_state_ev *ev = llc_conn_ev(skb);
560 
561 	return ev->type != LLC_CONN_EV_TYPE_REJ_TMR;
562 }
563 
llc_conn_ev_busy_tmr_exp(struct sock * sk,struct sk_buff * skb)564 int llc_conn_ev_busy_tmr_exp(struct sock *sk, struct sk_buff *skb)
565 {
566 	const struct llc_conn_state_ev *ev = llc_conn_ev(skb);
567 
568 	return ev->type != LLC_CONN_EV_TYPE_BUSY_TMR;
569 }
570 
llc_conn_ev_init_p_f_cycle(struct sock * sk,struct sk_buff * skb)571 int llc_conn_ev_init_p_f_cycle(struct sock *sk, struct sk_buff *skb)
572 {
573 	return 1;
574 }
575 
llc_conn_ev_tx_buffer_full(struct sock * sk,struct sk_buff * skb)576 int llc_conn_ev_tx_buffer_full(struct sock *sk, struct sk_buff *skb)
577 {
578 	const struct llc_conn_state_ev *ev = llc_conn_ev(skb);
579 
580 	return ev->type == LLC_CONN_EV_TYPE_SIMPLE &&
581 	       ev->prim_type == LLC_CONN_EV_TX_BUFF_FULL ? 0 : 1;
582 }
583 
584 /* Event qualifier functions
585  *
586  * these functions simply verify the value of a state flag associated with
587  * the connection and return either a 0 for success or a non-zero value
588  * for not-success; verify the event is the type we expect
589  */
llc_conn_ev_qlfy_data_flag_eq_1(struct sock * sk,struct sk_buff * skb)590 int llc_conn_ev_qlfy_data_flag_eq_1(struct sock *sk, struct sk_buff *skb)
591 {
592 	return llc_sk(sk)->data_flag != 1;
593 }
594 
llc_conn_ev_qlfy_data_flag_eq_0(struct sock * sk,struct sk_buff * skb)595 int llc_conn_ev_qlfy_data_flag_eq_0(struct sock *sk, struct sk_buff *skb)
596 {
597 	return llc_sk(sk)->data_flag;
598 }
599 
llc_conn_ev_qlfy_data_flag_eq_2(struct sock * sk,struct sk_buff * skb)600 int llc_conn_ev_qlfy_data_flag_eq_2(struct sock *sk, struct sk_buff *skb)
601 {
602 	return llc_sk(sk)->data_flag != 2;
603 }
604 
llc_conn_ev_qlfy_p_flag_eq_1(struct sock * sk,struct sk_buff * skb)605 int llc_conn_ev_qlfy_p_flag_eq_1(struct sock *sk, struct sk_buff *skb)
606 {
607 	return llc_sk(sk)->p_flag != 1;
608 }
609 
610 /**
611  *	llc_conn_ev_qlfy_last_frame_eq_1 - checks if frame is last in tx window
612  *	@sk: current connection structure.
613  *	@skb: current event.
614  *
615  *	This function determines when frame which is sent, is last frame of
616  *	transmit window, if it is then this function return zero else return
617  *	one.  This function is used for sending last frame of transmit window
618  *	as I-format command with p-bit set to one. Returns 0 if frame is last
619  *	frame, 1 otherwise.
620  */
llc_conn_ev_qlfy_last_frame_eq_1(struct sock * sk,struct sk_buff * skb)621 int llc_conn_ev_qlfy_last_frame_eq_1(struct sock *sk, struct sk_buff *skb)
622 {
623 	return !(skb_queue_len(&llc_sk(sk)->pdu_unack_q) + 1 == llc_sk(sk)->k);
624 }
625 
626 /**
627  *	llc_conn_ev_qlfy_last_frame_eq_0 - checks if frame isn't last in tx window
628  *	@sk: current connection structure.
629  *	@skb: current event.
630  *
631  *	This function determines when frame which is sent, isn't last frame of
632  *	transmit window, if it isn't then this function return zero else return
633  *	one. Returns 0 if frame isn't last frame, 1 otherwise.
634  */
llc_conn_ev_qlfy_last_frame_eq_0(struct sock * sk,struct sk_buff * skb)635 int llc_conn_ev_qlfy_last_frame_eq_0(struct sock *sk, struct sk_buff *skb)
636 {
637 	return skb_queue_len(&llc_sk(sk)->pdu_unack_q) + 1 == llc_sk(sk)->k;
638 }
639 
llc_conn_ev_qlfy_p_flag_eq_0(struct sock * sk,struct sk_buff * skb)640 int llc_conn_ev_qlfy_p_flag_eq_0(struct sock *sk, struct sk_buff *skb)
641 {
642 	return llc_sk(sk)->p_flag;
643 }
644 
llc_conn_ev_qlfy_p_flag_eq_f(struct sock * sk,struct sk_buff * skb)645 int llc_conn_ev_qlfy_p_flag_eq_f(struct sock *sk, struct sk_buff *skb)
646 {
647 	u8 f_bit;
648 
649 	llc_pdu_decode_pf_bit(skb, &f_bit);
650 	return llc_sk(sk)->p_flag == f_bit ? 0 : 1;
651 }
652 
llc_conn_ev_qlfy_remote_busy_eq_0(struct sock * sk,struct sk_buff * skb)653 int llc_conn_ev_qlfy_remote_busy_eq_0(struct sock *sk, struct sk_buff *skb)
654 {
655 	return llc_sk(sk)->remote_busy_flag;
656 }
657 
llc_conn_ev_qlfy_remote_busy_eq_1(struct sock * sk,struct sk_buff * skb)658 int llc_conn_ev_qlfy_remote_busy_eq_1(struct sock *sk, struct sk_buff *skb)
659 {
660 	return !llc_sk(sk)->remote_busy_flag;
661 }
662 
llc_conn_ev_qlfy_retry_cnt_lt_n2(struct sock * sk,struct sk_buff * skb)663 int llc_conn_ev_qlfy_retry_cnt_lt_n2(struct sock *sk, struct sk_buff *skb)
664 {
665 	return !(llc_sk(sk)->retry_count < llc_sk(sk)->n2);
666 }
667 
llc_conn_ev_qlfy_retry_cnt_gte_n2(struct sock * sk,struct sk_buff * skb)668 int llc_conn_ev_qlfy_retry_cnt_gte_n2(struct sock *sk, struct sk_buff *skb)
669 {
670 	return !(llc_sk(sk)->retry_count >= llc_sk(sk)->n2);
671 }
672 
llc_conn_ev_qlfy_s_flag_eq_1(struct sock * sk,struct sk_buff * skb)673 int llc_conn_ev_qlfy_s_flag_eq_1(struct sock *sk, struct sk_buff *skb)
674 {
675 	return !llc_sk(sk)->s_flag;
676 }
677 
llc_conn_ev_qlfy_s_flag_eq_0(struct sock * sk,struct sk_buff * skb)678 int llc_conn_ev_qlfy_s_flag_eq_0(struct sock *sk, struct sk_buff *skb)
679 {
680 	return llc_sk(sk)->s_flag;
681 }
682 
llc_conn_ev_qlfy_cause_flag_eq_1(struct sock * sk,struct sk_buff * skb)683 int llc_conn_ev_qlfy_cause_flag_eq_1(struct sock *sk, struct sk_buff *skb)
684 {
685 	return !llc_sk(sk)->cause_flag;
686 }
687 
llc_conn_ev_qlfy_cause_flag_eq_0(struct sock * sk,struct sk_buff * skb)688 int llc_conn_ev_qlfy_cause_flag_eq_0(struct sock *sk, struct sk_buff *skb)
689 {
690 	return llc_sk(sk)->cause_flag;
691 }
692 
llc_conn_ev_qlfy_set_status_conn(struct sock * sk,struct sk_buff * skb)693 int llc_conn_ev_qlfy_set_status_conn(struct sock *sk, struct sk_buff *skb)
694 {
695 	struct llc_conn_state_ev *ev = llc_conn_ev(skb);
696 
697 	ev->status = LLC_STATUS_CONN;
698 	return 0;
699 }
700 
llc_conn_ev_qlfy_set_status_disc(struct sock * sk,struct sk_buff * skb)701 int llc_conn_ev_qlfy_set_status_disc(struct sock *sk, struct sk_buff *skb)
702 {
703 	struct llc_conn_state_ev *ev = llc_conn_ev(skb);
704 
705 	ev->status = LLC_STATUS_DISC;
706 	return 0;
707 }
708 
llc_conn_ev_qlfy_set_status_failed(struct sock * sk,struct sk_buff * skb)709 int llc_conn_ev_qlfy_set_status_failed(struct sock *sk, struct sk_buff *skb)
710 {
711 	struct llc_conn_state_ev *ev = llc_conn_ev(skb);
712 
713 	ev->status = LLC_STATUS_FAILED;
714 	return 0;
715 }
716 
llc_conn_ev_qlfy_set_status_remote_busy(struct sock * sk,struct sk_buff * skb)717 int llc_conn_ev_qlfy_set_status_remote_busy(struct sock *sk,
718 					    struct sk_buff *skb)
719 {
720 	struct llc_conn_state_ev *ev = llc_conn_ev(skb);
721 
722 	ev->status = LLC_STATUS_REMOTE_BUSY;
723 	return 0;
724 }
725 
llc_conn_ev_qlfy_set_status_refuse(struct sock * sk,struct sk_buff * skb)726 int llc_conn_ev_qlfy_set_status_refuse(struct sock *sk, struct sk_buff *skb)
727 {
728 	struct llc_conn_state_ev *ev = llc_conn_ev(skb);
729 
730 	ev->status = LLC_STATUS_REFUSE;
731 	return 0;
732 }
733 
llc_conn_ev_qlfy_set_status_conflict(struct sock * sk,struct sk_buff * skb)734 int llc_conn_ev_qlfy_set_status_conflict(struct sock *sk, struct sk_buff *skb)
735 {
736 	struct llc_conn_state_ev *ev = llc_conn_ev(skb);
737 
738 	ev->status = LLC_STATUS_CONFLICT;
739 	return 0;
740 }
741 
llc_conn_ev_qlfy_set_status_rst_done(struct sock * sk,struct sk_buff * skb)742 int llc_conn_ev_qlfy_set_status_rst_done(struct sock *sk, struct sk_buff *skb)
743 {
744 	struct llc_conn_state_ev *ev = llc_conn_ev(skb);
745 
746 	ev->status = LLC_STATUS_RESET_DONE;
747 	return 0;
748 }
749