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1da177e4 LT |
1 | /* |
2 | * llc_station.c - station component of LLC | |
3 | * | |
4 | * Copyright (c) 1997 by Procom Technology, Inc. | |
5 | * 2001-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br> | |
6 | * | |
7 | * This program can be redistributed or modified under the terms of the | |
8 | * GNU General Public License as published by the Free Software Foundation. | |
9 | * This program is distributed without any warranty or implied warranty | |
10 | * of merchantability or fitness for a particular purpose. | |
11 | * | |
12 | * See the GNU General Public License for more details. | |
13 | */ | |
14 | #include <linux/config.h> | |
15 | #include <linux/init.h> | |
16 | #include <linux/module.h> | |
17 | #include <net/llc.h> | |
18 | #include <net/llc_sap.h> | |
19 | #include <net/llc_conn.h> | |
20 | #include <net/llc_c_ac.h> | |
21 | #include <net/llc_s_ac.h> | |
22 | #include <net/llc_c_ev.h> | |
23 | #include <net/llc_c_st.h> | |
24 | #include <net/llc_s_ev.h> | |
25 | #include <net/llc_s_st.h> | |
26 | #include <net/llc_pdu.h> | |
27 | ||
28 | /** | |
29 | * struct llc_station - LLC station component | |
30 | * | |
31 | * SAP and connection resource manager, one per adapter. | |
32 | * | |
33 | * @state - state of station | |
34 | * @xid_r_count - XID response PDU counter | |
35 | * @mac_sa - MAC source address | |
36 | * @sap_list - list of related SAPs | |
37 | * @ev_q - events entering state mach. | |
38 | * @mac_pdu_q - PDUs ready to send to MAC | |
39 | */ | |
40 | struct llc_station { | |
41 | u8 state; | |
42 | u8 xid_r_count; | |
43 | struct timer_list ack_timer; | |
44 | u8 retry_count; | |
45 | u8 maximum_retry; | |
46 | struct { | |
47 | struct sk_buff_head list; | |
48 | spinlock_t lock; | |
49 | } ev_q; | |
50 | struct sk_buff_head mac_pdu_q; | |
51 | }; | |
52 | ||
590232a7 ACM |
53 | #define LLC_STATION_ACK_TIME (3 * HZ) |
54 | ||
55 | int sysctl_llc_station_ack_timeout = LLC_STATION_ACK_TIME; | |
56 | ||
1da177e4 LT |
57 | /* Types of events (possible values in 'ev->type') */ |
58 | #define LLC_STATION_EV_TYPE_SIMPLE 1 | |
59 | #define LLC_STATION_EV_TYPE_CONDITION 2 | |
60 | #define LLC_STATION_EV_TYPE_PRIM 3 | |
61 | #define LLC_STATION_EV_TYPE_PDU 4 /* command/response PDU */ | |
62 | #define LLC_STATION_EV_TYPE_ACK_TMR 5 | |
63 | #define LLC_STATION_EV_TYPE_RPT_STATUS 6 | |
64 | ||
65 | /* Events */ | |
66 | #define LLC_STATION_EV_ENABLE_WITH_DUP_ADDR_CHECK 1 | |
67 | #define LLC_STATION_EV_ENABLE_WITHOUT_DUP_ADDR_CHECK 2 | |
68 | #define LLC_STATION_EV_ACK_TMR_EXP_LT_RETRY_CNT_MAX_RETRY 3 | |
69 | #define LLC_STATION_EV_ACK_TMR_EXP_EQ_RETRY_CNT_MAX_RETRY 4 | |
70 | #define LLC_STATION_EV_RX_NULL_DSAP_XID_C 5 | |
71 | #define LLC_STATION_EV_RX_NULL_DSAP_0_XID_R_XID_R_CNT_EQ 6 | |
72 | #define LLC_STATION_EV_RX_NULL_DSAP_1_XID_R_XID_R_CNT_EQ 7 | |
73 | #define LLC_STATION_EV_RX_NULL_DSAP_TEST_C 8 | |
74 | #define LLC_STATION_EV_DISABLE_REQ 9 | |
75 | ||
76 | struct llc_station_state_ev { | |
77 | u8 type; | |
78 | u8 prim; | |
79 | u8 prim_type; | |
80 | u8 reason; | |
81 | struct list_head node; /* node in station->ev_q.list */ | |
82 | }; | |
83 | ||
84 | static __inline__ struct llc_station_state_ev * | |
85 | llc_station_ev(struct sk_buff *skb) | |
86 | { | |
87 | return (struct llc_station_state_ev *)skb->cb; | |
88 | } | |
89 | ||
90 | typedef int (*llc_station_ev_t)(struct sk_buff *skb); | |
91 | ||
92 | #define LLC_STATION_STATE_DOWN 1 /* initial state */ | |
93 | #define LLC_STATION_STATE_DUP_ADDR_CHK 2 | |
94 | #define LLC_STATION_STATE_UP 3 | |
95 | ||
96 | #define LLC_NBR_STATION_STATES 3 /* size of state table */ | |
97 | ||
98 | typedef int (*llc_station_action_t)(struct sk_buff *skb); | |
99 | ||
100 | /* Station component state table structure */ | |
101 | struct llc_station_state_trans { | |
102 | llc_station_ev_t ev; | |
103 | u8 next_state; | |
104 | llc_station_action_t *ev_actions; | |
105 | }; | |
106 | ||
107 | struct llc_station_state { | |
108 | u8 curr_state; | |
109 | struct llc_station_state_trans **transitions; | |
110 | }; | |
111 | ||
112 | static struct llc_station llc_main_station; | |
113 | ||
114 | static int llc_stat_ev_enable_with_dup_addr_check(struct sk_buff *skb) | |
115 | { | |
116 | struct llc_station_state_ev *ev = llc_station_ev(skb); | |
117 | ||
118 | return ev->type == LLC_STATION_EV_TYPE_SIMPLE && | |
119 | ev->prim_type == | |
120 | LLC_STATION_EV_ENABLE_WITH_DUP_ADDR_CHECK ? 0 : 1; | |
121 | } | |
122 | ||
123 | static int llc_stat_ev_enable_without_dup_addr_check(struct sk_buff *skb) | |
124 | { | |
125 | struct llc_station_state_ev *ev = llc_station_ev(skb); | |
126 | ||
127 | return ev->type == LLC_STATION_EV_TYPE_SIMPLE && | |
128 | ev->prim_type == | |
129 | LLC_STATION_EV_ENABLE_WITHOUT_DUP_ADDR_CHECK ? 0 : 1; | |
130 | } | |
131 | ||
132 | static int llc_stat_ev_ack_tmr_exp_lt_retry_cnt_max_retry(struct sk_buff *skb) | |
133 | { | |
134 | struct llc_station_state_ev *ev = llc_station_ev(skb); | |
135 | ||
136 | return ev->type == LLC_STATION_EV_TYPE_ACK_TMR && | |
137 | llc_main_station.retry_count < | |
138 | llc_main_station.maximum_retry ? 0 : 1; | |
139 | } | |
140 | ||
141 | static int llc_stat_ev_ack_tmr_exp_eq_retry_cnt_max_retry(struct sk_buff *skb) | |
142 | { | |
143 | struct llc_station_state_ev *ev = llc_station_ev(skb); | |
144 | ||
145 | return ev->type == LLC_STATION_EV_TYPE_ACK_TMR && | |
146 | llc_main_station.retry_count == | |
147 | llc_main_station.maximum_retry ? 0 : 1; | |
148 | } | |
149 | ||
150 | static int llc_stat_ev_rx_null_dsap_xid_c(struct sk_buff *skb) | |
151 | { | |
152 | struct llc_station_state_ev *ev = llc_station_ev(skb); | |
153 | struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb); | |
154 | ||
155 | return ev->type == LLC_STATION_EV_TYPE_PDU && | |
156 | LLC_PDU_IS_CMD(pdu) && /* command PDU */ | |
157 | LLC_PDU_TYPE_IS_U(pdu) && /* U type PDU */ | |
158 | LLC_U_PDU_CMD(pdu) == LLC_1_PDU_CMD_XID && | |
159 | !pdu->dsap ? 0 : 1; /* NULL DSAP value */ | |
160 | } | |
161 | ||
162 | static int llc_stat_ev_rx_null_dsap_0_xid_r_xid_r_cnt_eq(struct sk_buff *skb) | |
163 | { | |
164 | struct llc_station_state_ev *ev = llc_station_ev(skb); | |
165 | struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb); | |
166 | ||
167 | return ev->type == LLC_STATION_EV_TYPE_PDU && | |
168 | LLC_PDU_IS_RSP(pdu) && /* response PDU */ | |
169 | LLC_PDU_TYPE_IS_U(pdu) && /* U type PDU */ | |
170 | LLC_U_PDU_RSP(pdu) == LLC_1_PDU_CMD_XID && | |
171 | !pdu->dsap && /* NULL DSAP value */ | |
172 | !llc_main_station.xid_r_count ? 0 : 1; | |
173 | } | |
174 | ||
175 | static int llc_stat_ev_rx_null_dsap_1_xid_r_xid_r_cnt_eq(struct sk_buff *skb) | |
176 | { | |
177 | struct llc_station_state_ev *ev = llc_station_ev(skb); | |
178 | struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb); | |
179 | ||
180 | return ev->type == LLC_STATION_EV_TYPE_PDU && | |
181 | LLC_PDU_IS_RSP(pdu) && /* response PDU */ | |
182 | LLC_PDU_TYPE_IS_U(pdu) && /* U type PDU */ | |
183 | LLC_U_PDU_RSP(pdu) == LLC_1_PDU_CMD_XID && | |
184 | !pdu->dsap && /* NULL DSAP value */ | |
185 | llc_main_station.xid_r_count == 1 ? 0 : 1; | |
186 | } | |
187 | ||
188 | static int llc_stat_ev_rx_null_dsap_test_c(struct sk_buff *skb) | |
189 | { | |
190 | struct llc_station_state_ev *ev = llc_station_ev(skb); | |
191 | struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb); | |
192 | ||
193 | return ev->type == LLC_STATION_EV_TYPE_PDU && | |
194 | LLC_PDU_IS_CMD(pdu) && /* command PDU */ | |
195 | LLC_PDU_TYPE_IS_U(pdu) && /* U type PDU */ | |
196 | LLC_U_PDU_CMD(pdu) == LLC_1_PDU_CMD_TEST && | |
197 | !pdu->dsap ? 0 : 1; /* NULL DSAP */ | |
198 | } | |
199 | ||
200 | static int llc_stat_ev_disable_req(struct sk_buff *skb) | |
201 | { | |
202 | struct llc_station_state_ev *ev = llc_station_ev(skb); | |
203 | ||
204 | return ev->type == LLC_STATION_EV_TYPE_PRIM && | |
205 | ev->prim == LLC_DISABLE_PRIM && | |
206 | ev->prim_type == LLC_PRIM_TYPE_REQ ? 0 : 1; | |
207 | } | |
208 | ||
209 | /** | |
210 | * llc_station_send_pdu - queues PDU to send | |
211 | * @skb: Address of the PDU | |
212 | * | |
213 | * Queues a PDU to send to the MAC layer. | |
214 | */ | |
215 | static void llc_station_send_pdu(struct sk_buff *skb) | |
216 | { | |
217 | skb_queue_tail(&llc_main_station.mac_pdu_q, skb); | |
218 | while ((skb = skb_dequeue(&llc_main_station.mac_pdu_q)) != NULL) | |
219 | if (dev_queue_xmit(skb)) | |
220 | break; | |
221 | } | |
222 | ||
223 | static int llc_station_ac_start_ack_timer(struct sk_buff *skb) | |
224 | { | |
590232a7 ACM |
225 | mod_timer(&llc_main_station.ack_timer, |
226 | jiffies + sysctl_llc_station_ack_timeout); | |
1da177e4 LT |
227 | return 0; |
228 | } | |
229 | ||
230 | static int llc_station_ac_set_retry_cnt_0(struct sk_buff *skb) | |
231 | { | |
232 | llc_main_station.retry_count = 0; | |
233 | return 0; | |
234 | } | |
235 | ||
236 | static int llc_station_ac_inc_retry_cnt_by_1(struct sk_buff *skb) | |
237 | { | |
238 | llc_main_station.retry_count++; | |
239 | return 0; | |
240 | } | |
241 | ||
242 | static int llc_station_ac_set_xid_r_cnt_0(struct sk_buff *skb) | |
243 | { | |
244 | llc_main_station.xid_r_count = 0; | |
245 | return 0; | |
246 | } | |
247 | ||
248 | static int llc_station_ac_inc_xid_r_cnt_by_1(struct sk_buff *skb) | |
249 | { | |
250 | llc_main_station.xid_r_count++; | |
251 | return 0; | |
252 | } | |
253 | ||
254 | static int llc_station_ac_send_null_dsap_xid_c(struct sk_buff *skb) | |
255 | { | |
256 | int rc = 1; | |
d389424e | 257 | struct sk_buff *nskb = llc_alloc_frame(NULL, skb->dev); |
1da177e4 LT |
258 | |
259 | if (!nskb) | |
260 | goto out; | |
261 | llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, 0, 0, LLC_PDU_CMD); | |
262 | llc_pdu_init_as_xid_cmd(nskb, LLC_XID_NULL_CLASS_2, 127); | |
263 | rc = llc_mac_hdr_init(nskb, llc_station_mac_sa, llc_station_mac_sa); | |
249ff1c6 | 264 | if (unlikely(rc)) |
1da177e4 LT |
265 | goto free; |
266 | llc_station_send_pdu(nskb); | |
267 | out: | |
268 | return rc; | |
269 | free: | |
270 | kfree_skb(skb); | |
271 | goto out; | |
272 | } | |
273 | ||
274 | static int llc_station_ac_send_xid_r(struct sk_buff *skb) | |
275 | { | |
276 | u8 mac_da[ETH_ALEN], dsap; | |
277 | int rc = 1; | |
d389424e | 278 | struct sk_buff* nskb = llc_alloc_frame(NULL, skb->dev); |
1da177e4 LT |
279 | |
280 | if (!nskb) | |
281 | goto out; | |
282 | rc = 0; | |
1da177e4 LT |
283 | llc_pdu_decode_sa(skb, mac_da); |
284 | llc_pdu_decode_ssap(skb, &dsap); | |
285 | llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, 0, dsap, LLC_PDU_RSP); | |
286 | llc_pdu_init_as_xid_rsp(nskb, LLC_XID_NULL_CLASS_2, 127); | |
287 | rc = llc_mac_hdr_init(nskb, llc_station_mac_sa, mac_da); | |
249ff1c6 | 288 | if (unlikely(rc)) |
1da177e4 LT |
289 | goto free; |
290 | llc_station_send_pdu(nskb); | |
291 | out: | |
292 | return rc; | |
293 | free: | |
294 | kfree_skb(skb); | |
295 | goto out; | |
296 | } | |
297 | ||
298 | static int llc_station_ac_send_test_r(struct sk_buff *skb) | |
299 | { | |
300 | u8 mac_da[ETH_ALEN], dsap; | |
301 | int rc = 1; | |
d389424e | 302 | struct sk_buff *nskb = llc_alloc_frame(NULL, skb->dev); |
1da177e4 LT |
303 | |
304 | if (!nskb) | |
305 | goto out; | |
306 | rc = 0; | |
1da177e4 LT |
307 | llc_pdu_decode_sa(skb, mac_da); |
308 | llc_pdu_decode_ssap(skb, &dsap); | |
309 | llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, 0, dsap, LLC_PDU_RSP); | |
310 | llc_pdu_init_as_test_rsp(nskb, skb); | |
311 | rc = llc_mac_hdr_init(nskb, llc_station_mac_sa, mac_da); | |
249ff1c6 | 312 | if (unlikely(rc)) |
1da177e4 LT |
313 | goto free; |
314 | llc_station_send_pdu(nskb); | |
315 | out: | |
316 | return rc; | |
317 | free: | |
318 | kfree_skb(skb); | |
319 | goto out; | |
320 | } | |
321 | ||
322 | static int llc_station_ac_report_status(struct sk_buff *skb) | |
323 | { | |
324 | return 0; | |
325 | } | |
326 | ||
327 | /* COMMON STATION STATE transitions */ | |
328 | ||
329 | /* dummy last-transition indicator; common to all state transition groups | |
330 | * last entry for this state | |
331 | * all members are zeros, .bss zeroes it | |
332 | */ | |
333 | static struct llc_station_state_trans llc_stat_state_trans_end; | |
334 | ||
335 | /* DOWN STATE transitions */ | |
336 | ||
337 | /* state transition for LLC_STATION_EV_ENABLE_WITH_DUP_ADDR_CHECK event */ | |
338 | static llc_station_action_t llc_stat_down_state_actions_1[] = { | |
339 | [0] = llc_station_ac_start_ack_timer, | |
340 | [1] = llc_station_ac_set_retry_cnt_0, | |
341 | [2] = llc_station_ac_set_xid_r_cnt_0, | |
342 | [3] = llc_station_ac_send_null_dsap_xid_c, | |
343 | [4] = NULL, | |
344 | }; | |
345 | ||
346 | static struct llc_station_state_trans llc_stat_down_state_trans_1 = { | |
347 | .ev = llc_stat_ev_enable_with_dup_addr_check, | |
348 | .next_state = LLC_STATION_STATE_DUP_ADDR_CHK, | |
349 | .ev_actions = llc_stat_down_state_actions_1, | |
350 | }; | |
351 | ||
352 | /* state transition for LLC_STATION_EV_ENABLE_WITHOUT_DUP_ADDR_CHECK event */ | |
353 | static llc_station_action_t llc_stat_down_state_actions_2[] = { | |
354 | [0] = llc_station_ac_report_status, /* STATION UP */ | |
355 | [1] = NULL, | |
356 | }; | |
357 | ||
358 | static struct llc_station_state_trans llc_stat_down_state_trans_2 = { | |
359 | .ev = llc_stat_ev_enable_without_dup_addr_check, | |
360 | .next_state = LLC_STATION_STATE_UP, | |
361 | .ev_actions = llc_stat_down_state_actions_2, | |
362 | }; | |
363 | ||
364 | /* array of pointers; one to each transition */ | |
365 | static struct llc_station_state_trans *llc_stat_dwn_state_trans[] = { | |
366 | [0] = &llc_stat_down_state_trans_1, | |
367 | [1] = &llc_stat_down_state_trans_2, | |
368 | [2] = &llc_stat_state_trans_end, | |
369 | }; | |
370 | ||
371 | /* UP STATE transitions */ | |
372 | /* state transition for LLC_STATION_EV_DISABLE_REQ event */ | |
373 | static llc_station_action_t llc_stat_up_state_actions_1[] = { | |
374 | [0] = llc_station_ac_report_status, /* STATION DOWN */ | |
375 | [1] = NULL, | |
376 | }; | |
377 | ||
378 | static struct llc_station_state_trans llc_stat_up_state_trans_1 = { | |
379 | .ev = llc_stat_ev_disable_req, | |
380 | .next_state = LLC_STATION_STATE_DOWN, | |
381 | .ev_actions = llc_stat_up_state_actions_1, | |
382 | }; | |
383 | ||
384 | /* state transition for LLC_STATION_EV_RX_NULL_DSAP_XID_C event */ | |
385 | static llc_station_action_t llc_stat_up_state_actions_2[] = { | |
386 | [0] = llc_station_ac_send_xid_r, | |
387 | [1] = NULL, | |
388 | }; | |
389 | ||
390 | static struct llc_station_state_trans llc_stat_up_state_trans_2 = { | |
391 | .ev = llc_stat_ev_rx_null_dsap_xid_c, | |
392 | .next_state = LLC_STATION_STATE_UP, | |
393 | .ev_actions = llc_stat_up_state_actions_2, | |
394 | }; | |
395 | ||
396 | /* state transition for LLC_STATION_EV_RX_NULL_DSAP_TEST_C event */ | |
397 | static llc_station_action_t llc_stat_up_state_actions_3[] = { | |
398 | [0] = llc_station_ac_send_test_r, | |
399 | [1] = NULL, | |
400 | }; | |
401 | ||
402 | static struct llc_station_state_trans llc_stat_up_state_trans_3 = { | |
403 | .ev = llc_stat_ev_rx_null_dsap_test_c, | |
404 | .next_state = LLC_STATION_STATE_UP, | |
405 | .ev_actions = llc_stat_up_state_actions_3, | |
406 | }; | |
407 | ||
408 | /* array of pointers; one to each transition */ | |
409 | static struct llc_station_state_trans *llc_stat_up_state_trans [] = { | |
410 | [0] = &llc_stat_up_state_trans_1, | |
411 | [1] = &llc_stat_up_state_trans_2, | |
412 | [2] = &llc_stat_up_state_trans_3, | |
413 | [3] = &llc_stat_state_trans_end, | |
414 | }; | |
415 | ||
416 | /* DUP ADDR CHK STATE transitions */ | |
417 | /* state transition for LLC_STATION_EV_RX_NULL_DSAP_0_XID_R_XID_R_CNT_EQ | |
418 | * event | |
419 | */ | |
420 | static llc_station_action_t llc_stat_dupaddr_state_actions_1[] = { | |
421 | [0] = llc_station_ac_inc_xid_r_cnt_by_1, | |
422 | [1] = NULL, | |
423 | }; | |
424 | ||
425 | static struct llc_station_state_trans llc_stat_dupaddr_state_trans_1 = { | |
426 | .ev = llc_stat_ev_rx_null_dsap_0_xid_r_xid_r_cnt_eq, | |
427 | .next_state = LLC_STATION_STATE_DUP_ADDR_CHK, | |
428 | .ev_actions = llc_stat_dupaddr_state_actions_1, | |
429 | }; | |
430 | ||
431 | /* state transition for LLC_STATION_EV_RX_NULL_DSAP_1_XID_R_XID_R_CNT_EQ | |
432 | * event | |
433 | */ | |
434 | static llc_station_action_t llc_stat_dupaddr_state_actions_2[] = { | |
435 | [0] = llc_station_ac_report_status, /* DUPLICATE ADDRESS FOUND */ | |
436 | [1] = NULL, | |
437 | }; | |
438 | ||
439 | static struct llc_station_state_trans llc_stat_dupaddr_state_trans_2 = { | |
440 | .ev = llc_stat_ev_rx_null_dsap_1_xid_r_xid_r_cnt_eq, | |
441 | .next_state = LLC_STATION_STATE_DOWN, | |
442 | .ev_actions = llc_stat_dupaddr_state_actions_2, | |
443 | }; | |
444 | ||
445 | /* state transition for LLC_STATION_EV_RX_NULL_DSAP_XID_C event */ | |
446 | static llc_station_action_t llc_stat_dupaddr_state_actions_3[] = { | |
447 | [0] = llc_station_ac_send_xid_r, | |
448 | [1] = NULL, | |
449 | }; | |
450 | ||
451 | static struct llc_station_state_trans llc_stat_dupaddr_state_trans_3 = { | |
452 | .ev = llc_stat_ev_rx_null_dsap_xid_c, | |
453 | .next_state = LLC_STATION_STATE_DUP_ADDR_CHK, | |
454 | .ev_actions = llc_stat_dupaddr_state_actions_3, | |
455 | }; | |
456 | ||
457 | /* state transition for LLC_STATION_EV_ACK_TMR_EXP_LT_RETRY_CNT_MAX_RETRY | |
458 | * event | |
459 | */ | |
460 | static llc_station_action_t llc_stat_dupaddr_state_actions_4[] = { | |
461 | [0] = llc_station_ac_start_ack_timer, | |
462 | [1] = llc_station_ac_inc_retry_cnt_by_1, | |
463 | [2] = llc_station_ac_set_xid_r_cnt_0, | |
464 | [3] = llc_station_ac_send_null_dsap_xid_c, | |
465 | [4] = NULL, | |
466 | }; | |
467 | ||
468 | static struct llc_station_state_trans llc_stat_dupaddr_state_trans_4 = { | |
469 | .ev = llc_stat_ev_ack_tmr_exp_lt_retry_cnt_max_retry, | |
470 | .next_state = LLC_STATION_STATE_DUP_ADDR_CHK, | |
471 | .ev_actions = llc_stat_dupaddr_state_actions_4, | |
472 | }; | |
473 | ||
474 | /* state transition for LLC_STATION_EV_ACK_TMR_EXP_EQ_RETRY_CNT_MAX_RETRY | |
475 | * event | |
476 | */ | |
477 | static llc_station_action_t llc_stat_dupaddr_state_actions_5[] = { | |
478 | [0] = llc_station_ac_report_status, /* STATION UP */ | |
479 | [1] = NULL, | |
480 | }; | |
481 | ||
482 | static struct llc_station_state_trans llc_stat_dupaddr_state_trans_5 = { | |
483 | .ev = llc_stat_ev_ack_tmr_exp_eq_retry_cnt_max_retry, | |
484 | .next_state = LLC_STATION_STATE_UP, | |
485 | .ev_actions = llc_stat_dupaddr_state_actions_5, | |
486 | }; | |
487 | ||
488 | /* state transition for LLC_STATION_EV_DISABLE_REQ event */ | |
489 | static llc_station_action_t llc_stat_dupaddr_state_actions_6[] = { | |
490 | [0] = llc_station_ac_report_status, /* STATION DOWN */ | |
491 | [1] = NULL, | |
492 | }; | |
493 | ||
494 | static struct llc_station_state_trans llc_stat_dupaddr_state_trans_6 = { | |
495 | .ev = llc_stat_ev_disable_req, | |
496 | .next_state = LLC_STATION_STATE_DOWN, | |
497 | .ev_actions = llc_stat_dupaddr_state_actions_6, | |
498 | }; | |
499 | ||
500 | /* array of pointers; one to each transition */ | |
501 | static struct llc_station_state_trans *llc_stat_dupaddr_state_trans[] = { | |
502 | [0] = &llc_stat_dupaddr_state_trans_6, /* Request */ | |
503 | [1] = &llc_stat_dupaddr_state_trans_4, /* Timer */ | |
504 | [2] = &llc_stat_dupaddr_state_trans_5, | |
505 | [3] = &llc_stat_dupaddr_state_trans_1, /* Receive frame */ | |
506 | [4] = &llc_stat_dupaddr_state_trans_2, | |
507 | [5] = &llc_stat_dupaddr_state_trans_3, | |
508 | [6] = &llc_stat_state_trans_end, | |
509 | }; | |
510 | ||
511 | static struct llc_station_state | |
512 | llc_station_state_table[LLC_NBR_STATION_STATES] = { | |
513 | [LLC_STATION_STATE_DOWN - 1] = { | |
514 | .curr_state = LLC_STATION_STATE_DOWN, | |
515 | .transitions = llc_stat_dwn_state_trans, | |
516 | }, | |
517 | [LLC_STATION_STATE_DUP_ADDR_CHK - 1] = { | |
518 | .curr_state = LLC_STATION_STATE_DUP_ADDR_CHK, | |
519 | .transitions = llc_stat_dupaddr_state_trans, | |
520 | }, | |
521 | [LLC_STATION_STATE_UP - 1] = { | |
522 | .curr_state = LLC_STATION_STATE_UP, | |
523 | .transitions = llc_stat_up_state_trans, | |
524 | }, | |
525 | }; | |
526 | ||
527 | /** | |
528 | * llc_exec_station_trans_actions - executes actions for transition | |
529 | * @trans: Address of the transition | |
530 | * @skb: Address of the event that caused the transition | |
531 | * | |
532 | * Executes actions of a transition of the station state machine. Returns | |
533 | * 0 if all actions complete successfully, nonzero otherwise. | |
534 | */ | |
535 | static u16 llc_exec_station_trans_actions(struct llc_station_state_trans *trans, | |
536 | struct sk_buff *skb) | |
537 | { | |
538 | u16 rc = 0; | |
539 | llc_station_action_t *next_action = trans->ev_actions; | |
540 | ||
541 | for (; next_action && *next_action; next_action++) | |
542 | if ((*next_action)(skb)) | |
543 | rc = 1; | |
544 | return rc; | |
545 | } | |
546 | ||
547 | /** | |
548 | * llc_find_station_trans - finds transition for this event | |
549 | * @skb: Address of the event | |
550 | * | |
551 | * Search thru events of the current state of the station until list | |
552 | * exhausted or it's obvious that the event is not valid for the current | |
553 | * state. Returns the address of the transition if cound, %NULL otherwise. | |
554 | */ | |
555 | static struct llc_station_state_trans * | |
556 | llc_find_station_trans(struct sk_buff *skb) | |
557 | { | |
558 | int i = 0; | |
559 | struct llc_station_state_trans *rc = NULL; | |
560 | struct llc_station_state_trans **next_trans; | |
561 | struct llc_station_state *curr_state = | |
562 | &llc_station_state_table[llc_main_station.state - 1]; | |
563 | ||
564 | for (next_trans = curr_state->transitions; next_trans[i]->ev; i++) | |
565 | if (!next_trans[i]->ev(skb)) { | |
566 | rc = next_trans[i]; | |
567 | break; | |
568 | } | |
569 | return rc; | |
570 | } | |
571 | ||
572 | /** | |
573 | * llc_station_free_ev - frees an event | |
574 | * @skb: Address of the event | |
575 | * | |
576 | * Frees an event. | |
577 | */ | |
578 | static void llc_station_free_ev(struct sk_buff *skb) | |
579 | { | |
580 | struct llc_station_state_ev *ev = llc_station_ev(skb); | |
581 | ||
582 | if (ev->type == LLC_STATION_EV_TYPE_PDU) | |
583 | kfree_skb(skb); | |
584 | } | |
585 | ||
586 | /** | |
587 | * llc_station_next_state - processes event and goes to the next state | |
588 | * @skb: Address of the event | |
589 | * | |
590 | * Processes an event, executes any transitions related to that event and | |
591 | * updates the state of the station. | |
592 | */ | |
593 | static u16 llc_station_next_state(struct sk_buff *skb) | |
594 | { | |
595 | u16 rc = 1; | |
596 | struct llc_station_state_trans *trans; | |
597 | ||
598 | if (llc_main_station.state > LLC_NBR_STATION_STATES) | |
599 | goto out; | |
600 | trans = llc_find_station_trans(skb); | |
601 | if (trans) { | |
602 | /* got the state to which we next transition; perform the | |
603 | * actions associated with this transition before actually | |
604 | * transitioning to the next state | |
605 | */ | |
606 | rc = llc_exec_station_trans_actions(trans, skb); | |
607 | if (!rc) | |
608 | /* transition station to next state if all actions | |
609 | * execute successfully; done; wait for next event | |
610 | */ | |
611 | llc_main_station.state = trans->next_state; | |
612 | } else | |
613 | /* event not recognized in current state; re-queue it for | |
614 | * processing again at a later time; return failure | |
615 | */ | |
616 | rc = 0; | |
617 | out: | |
618 | llc_station_free_ev(skb); | |
619 | return rc; | |
620 | } | |
621 | ||
622 | /** | |
623 | * llc_station_service_events - service events in the queue | |
624 | * | |
625 | * Get an event from the station event queue (if any); attempt to service | |
626 | * the event; if event serviced, get the next event (if any) on the event | |
627 | * queue; if event not service, re-queue the event on the event queue and | |
628 | * attempt to service the next event; when serviced all events in queue, | |
629 | * finished; if don't transition to different state, just service all | |
630 | * events once; if transition to new state, service all events again. | |
631 | * Caller must hold llc_main_station.ev_q.lock. | |
632 | */ | |
633 | static void llc_station_service_events(void) | |
634 | { | |
635 | struct sk_buff *skb; | |
636 | ||
637 | while ((skb = skb_dequeue(&llc_main_station.ev_q.list)) != NULL) | |
638 | llc_station_next_state(skb); | |
639 | } | |
640 | ||
641 | /** | |
642 | * llc_station_state_process: queue event and try to process queue. | |
643 | * @skb: Address of the event | |
644 | * | |
645 | * Queues an event (on the station event queue) for handling by the | |
646 | * station state machine and attempts to process any queued-up events. | |
647 | */ | |
648 | static void llc_station_state_process(struct sk_buff *skb) | |
649 | { | |
650 | spin_lock_bh(&llc_main_station.ev_q.lock); | |
651 | skb_queue_tail(&llc_main_station.ev_q.list, skb); | |
652 | llc_station_service_events(); | |
653 | spin_unlock_bh(&llc_main_station.ev_q.lock); | |
654 | } | |
655 | ||
656 | static void llc_station_ack_tmr_cb(unsigned long timeout_data) | |
657 | { | |
658 | struct sk_buff *skb = alloc_skb(0, GFP_ATOMIC); | |
659 | ||
660 | if (skb) { | |
661 | struct llc_station_state_ev *ev = llc_station_ev(skb); | |
662 | ||
663 | ev->type = LLC_STATION_EV_TYPE_ACK_TMR; | |
664 | llc_station_state_process(skb); | |
665 | } | |
666 | } | |
667 | ||
668 | /* | |
669 | * llc_station_rcv - send received pdu to the station state machine | |
670 | * @skb: received frame. | |
671 | * | |
672 | * Sends data unit to station state machine. | |
673 | */ | |
674 | static void llc_station_rcv(struct sk_buff *skb) | |
675 | { | |
676 | struct llc_station_state_ev *ev = llc_station_ev(skb); | |
677 | ||
678 | ev->type = LLC_STATION_EV_TYPE_PDU; | |
679 | ev->reason = 0; | |
680 | llc_station_state_process(skb); | |
681 | } | |
682 | ||
683 | int __init llc_station_init(void) | |
684 | { | |
685 | u16 rc = -ENOBUFS; | |
686 | struct sk_buff *skb; | |
687 | struct llc_station_state_ev *ev; | |
688 | ||
689 | skb_queue_head_init(&llc_main_station.mac_pdu_q); | |
690 | skb_queue_head_init(&llc_main_station.ev_q.list); | |
691 | spin_lock_init(&llc_main_station.ev_q.lock); | |
692 | init_timer(&llc_main_station.ack_timer); | |
693 | llc_main_station.ack_timer.data = (unsigned long)&llc_main_station; | |
694 | llc_main_station.ack_timer.function = llc_station_ack_tmr_cb; | |
590232a7 ACM |
695 | llc_main_station.ack_timer.expires = jiffies + |
696 | sysctl_llc_station_ack_timeout; | |
1da177e4 LT |
697 | skb = alloc_skb(0, GFP_ATOMIC); |
698 | if (!skb) | |
699 | goto out; | |
700 | rc = 0; | |
701 | llc_set_station_handler(llc_station_rcv); | |
702 | ev = llc_station_ev(skb); | |
703 | memset(ev, 0, sizeof(*ev)); | |
1da177e4 LT |
704 | llc_main_station.maximum_retry = 1; |
705 | llc_main_station.state = LLC_STATION_STATE_DOWN; | |
706 | ev->type = LLC_STATION_EV_TYPE_SIMPLE; | |
707 | ev->prim_type = LLC_STATION_EV_ENABLE_WITHOUT_DUP_ADDR_CHECK; | |
708 | rc = llc_station_next_state(skb); | |
709 | out: | |
710 | return rc; | |
711 | } | |
712 | ||
713 | void __exit llc_station_exit(void) | |
714 | { | |
715 | llc_set_station_handler(NULL); | |
716 | } |