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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 | */ | |
1da177e4 LT |
14 | #include <linux/init.h> |
15 | #include <linux/module.h> | |
5a0e3ad6 | 16 | #include <linux/slab.h> |
1da177e4 LT |
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 | { | |
d57b1869 YH |
116 | struct llc_station_state_ev *ev = llc_station_ev(skb); |
117 | ||
1da177e4 LT |
118 | return ev->type == LLC_STATION_EV_TYPE_SIMPLE && |
119 | ev->prim_type == | |
d57b1869 | 120 | LLC_STATION_EV_ENABLE_WITH_DUP_ADDR_CHECK ? 0 : 1; |
1da177e4 LT |
121 | } |
122 | ||
123 | static int llc_stat_ev_enable_without_dup_addr_check(struct sk_buff *skb) | |
124 | { | |
d57b1869 YH |
125 | struct llc_station_state_ev *ev = llc_station_ev(skb); |
126 | ||
1da177e4 LT |
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 | { | |
d57b1869 YH |
134 | struct llc_station_state_ev *ev = llc_station_ev(skb); |
135 | ||
1da177e4 LT |
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 | { | |
d57b1869 YH |
143 | struct llc_station_state_ev *ev = llc_station_ev(skb); |
144 | ||
1da177e4 LT |
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 | { | |
d57b1869 | 152 | struct llc_station_state_ev *ev = llc_station_ev(skb); |
1da177e4 LT |
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; | |
f83f1768 JP |
257 | struct sk_buff *nskb = llc_alloc_frame(NULL, skb->dev, LLC_PDU_TYPE_U, |
258 | sizeof(struct llc_xid_info)); | |
1da177e4 LT |
259 | |
260 | if (!nskb) | |
261 | goto out; | |
262 | llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, 0, 0, LLC_PDU_CMD); | |
263 | llc_pdu_init_as_xid_cmd(nskb, LLC_XID_NULL_CLASS_2, 127); | |
a5a04819 | 264 | rc = llc_mac_hdr_init(nskb, skb->dev->dev_addr, skb->dev->dev_addr); |
249ff1c6 | 265 | if (unlikely(rc)) |
1da177e4 LT |
266 | goto free; |
267 | llc_station_send_pdu(nskb); | |
268 | out: | |
269 | return rc; | |
270 | free: | |
271 | kfree_skb(skb); | |
272 | goto out; | |
273 | } | |
274 | ||
275 | static int llc_station_ac_send_xid_r(struct sk_buff *skb) | |
276 | { | |
277 | u8 mac_da[ETH_ALEN], dsap; | |
278 | int rc = 1; | |
f83f1768 JP |
279 | struct sk_buff *nskb = llc_alloc_frame(NULL, skb->dev, LLC_PDU_TYPE_U, |
280 | sizeof(struct llc_xid_info)); | |
1da177e4 LT |
281 | |
282 | if (!nskb) | |
283 | goto out; | |
284 | rc = 0; | |
1da177e4 LT |
285 | llc_pdu_decode_sa(skb, mac_da); |
286 | llc_pdu_decode_ssap(skb, &dsap); | |
287 | llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, 0, dsap, LLC_PDU_RSP); | |
288 | llc_pdu_init_as_xid_rsp(nskb, LLC_XID_NULL_CLASS_2, 127); | |
a5a04819 | 289 | rc = llc_mac_hdr_init(nskb, skb->dev->dev_addr, mac_da); |
249ff1c6 | 290 | if (unlikely(rc)) |
1da177e4 LT |
291 | goto free; |
292 | llc_station_send_pdu(nskb); | |
293 | out: | |
294 | return rc; | |
295 | free: | |
296 | kfree_skb(skb); | |
297 | goto out; | |
298 | } | |
299 | ||
300 | static int llc_station_ac_send_test_r(struct sk_buff *skb) | |
301 | { | |
302 | u8 mac_da[ETH_ALEN], dsap; | |
303 | int rc = 1; | |
f83f1768 JP |
304 | u32 data_size; |
305 | struct sk_buff *nskb; | |
306 | ||
307 | /* The test request command is type U (llc_len = 3) */ | |
308 | data_size = ntohs(eth_hdr(skb)->h_proto) - 3; | |
309 | nskb = llc_alloc_frame(NULL, skb->dev, LLC_PDU_TYPE_U, data_size); | |
1da177e4 LT |
310 | |
311 | if (!nskb) | |
312 | goto out; | |
313 | rc = 0; | |
1da177e4 LT |
314 | llc_pdu_decode_sa(skb, mac_da); |
315 | llc_pdu_decode_ssap(skb, &dsap); | |
316 | llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, 0, dsap, LLC_PDU_RSP); | |
d57b1869 | 317 | llc_pdu_init_as_test_rsp(nskb, skb); |
a5a04819 | 318 | rc = llc_mac_hdr_init(nskb, skb->dev->dev_addr, mac_da); |
249ff1c6 | 319 | if (unlikely(rc)) |
1da177e4 LT |
320 | goto free; |
321 | llc_station_send_pdu(nskb); | |
322 | out: | |
323 | return rc; | |
324 | free: | |
325 | kfree_skb(skb); | |
326 | goto out; | |
327 | } | |
328 | ||
329 | static int llc_station_ac_report_status(struct sk_buff *skb) | |
330 | { | |
331 | return 0; | |
332 | } | |
333 | ||
334 | /* COMMON STATION STATE transitions */ | |
335 | ||
336 | /* dummy last-transition indicator; common to all state transition groups | |
337 | * last entry for this state | |
338 | * all members are zeros, .bss zeroes it | |
339 | */ | |
340 | static struct llc_station_state_trans llc_stat_state_trans_end; | |
341 | ||
342 | /* DOWN STATE transitions */ | |
343 | ||
344 | /* state transition for LLC_STATION_EV_ENABLE_WITH_DUP_ADDR_CHECK event */ | |
345 | static llc_station_action_t llc_stat_down_state_actions_1[] = { | |
346 | [0] = llc_station_ac_start_ack_timer, | |
347 | [1] = llc_station_ac_set_retry_cnt_0, | |
348 | [2] = llc_station_ac_set_xid_r_cnt_0, | |
349 | [3] = llc_station_ac_send_null_dsap_xid_c, | |
350 | [4] = NULL, | |
351 | }; | |
352 | ||
353 | static struct llc_station_state_trans llc_stat_down_state_trans_1 = { | |
354 | .ev = llc_stat_ev_enable_with_dup_addr_check, | |
355 | .next_state = LLC_STATION_STATE_DUP_ADDR_CHK, | |
356 | .ev_actions = llc_stat_down_state_actions_1, | |
357 | }; | |
358 | ||
359 | /* state transition for LLC_STATION_EV_ENABLE_WITHOUT_DUP_ADDR_CHECK event */ | |
360 | static llc_station_action_t llc_stat_down_state_actions_2[] = { | |
361 | [0] = llc_station_ac_report_status, /* STATION UP */ | |
362 | [1] = NULL, | |
363 | }; | |
364 | ||
365 | static struct llc_station_state_trans llc_stat_down_state_trans_2 = { | |
366 | .ev = llc_stat_ev_enable_without_dup_addr_check, | |
367 | .next_state = LLC_STATION_STATE_UP, | |
368 | .ev_actions = llc_stat_down_state_actions_2, | |
369 | }; | |
370 | ||
371 | /* array of pointers; one to each transition */ | |
372 | static struct llc_station_state_trans *llc_stat_dwn_state_trans[] = { | |
373 | [0] = &llc_stat_down_state_trans_1, | |
374 | [1] = &llc_stat_down_state_trans_2, | |
375 | [2] = &llc_stat_state_trans_end, | |
376 | }; | |
377 | ||
378 | /* UP STATE transitions */ | |
379 | /* state transition for LLC_STATION_EV_DISABLE_REQ event */ | |
380 | static llc_station_action_t llc_stat_up_state_actions_1[] = { | |
381 | [0] = llc_station_ac_report_status, /* STATION DOWN */ | |
382 | [1] = NULL, | |
383 | }; | |
384 | ||
385 | static struct llc_station_state_trans llc_stat_up_state_trans_1 = { | |
386 | .ev = llc_stat_ev_disable_req, | |
387 | .next_state = LLC_STATION_STATE_DOWN, | |
388 | .ev_actions = llc_stat_up_state_actions_1, | |
389 | }; | |
390 | ||
391 | /* state transition for LLC_STATION_EV_RX_NULL_DSAP_XID_C event */ | |
392 | static llc_station_action_t llc_stat_up_state_actions_2[] = { | |
393 | [0] = llc_station_ac_send_xid_r, | |
394 | [1] = NULL, | |
395 | }; | |
396 | ||
397 | static struct llc_station_state_trans llc_stat_up_state_trans_2 = { | |
398 | .ev = llc_stat_ev_rx_null_dsap_xid_c, | |
399 | .next_state = LLC_STATION_STATE_UP, | |
400 | .ev_actions = llc_stat_up_state_actions_2, | |
401 | }; | |
402 | ||
403 | /* state transition for LLC_STATION_EV_RX_NULL_DSAP_TEST_C event */ | |
404 | static llc_station_action_t llc_stat_up_state_actions_3[] = { | |
405 | [0] = llc_station_ac_send_test_r, | |
406 | [1] = NULL, | |
407 | }; | |
408 | ||
409 | static struct llc_station_state_trans llc_stat_up_state_trans_3 = { | |
410 | .ev = llc_stat_ev_rx_null_dsap_test_c, | |
411 | .next_state = LLC_STATION_STATE_UP, | |
412 | .ev_actions = llc_stat_up_state_actions_3, | |
413 | }; | |
414 | ||
415 | /* array of pointers; one to each transition */ | |
416 | static struct llc_station_state_trans *llc_stat_up_state_trans [] = { | |
417 | [0] = &llc_stat_up_state_trans_1, | |
418 | [1] = &llc_stat_up_state_trans_2, | |
419 | [2] = &llc_stat_up_state_trans_3, | |
420 | [3] = &llc_stat_state_trans_end, | |
421 | }; | |
422 | ||
423 | /* DUP ADDR CHK STATE transitions */ | |
424 | /* state transition for LLC_STATION_EV_RX_NULL_DSAP_0_XID_R_XID_R_CNT_EQ | |
425 | * event | |
426 | */ | |
427 | static llc_station_action_t llc_stat_dupaddr_state_actions_1[] = { | |
428 | [0] = llc_station_ac_inc_xid_r_cnt_by_1, | |
429 | [1] = NULL, | |
430 | }; | |
431 | ||
432 | static struct llc_station_state_trans llc_stat_dupaddr_state_trans_1 = { | |
433 | .ev = llc_stat_ev_rx_null_dsap_0_xid_r_xid_r_cnt_eq, | |
434 | .next_state = LLC_STATION_STATE_DUP_ADDR_CHK, | |
435 | .ev_actions = llc_stat_dupaddr_state_actions_1, | |
436 | }; | |
437 | ||
438 | /* state transition for LLC_STATION_EV_RX_NULL_DSAP_1_XID_R_XID_R_CNT_EQ | |
439 | * event | |
440 | */ | |
441 | static llc_station_action_t llc_stat_dupaddr_state_actions_2[] = { | |
442 | [0] = llc_station_ac_report_status, /* DUPLICATE ADDRESS FOUND */ | |
443 | [1] = NULL, | |
444 | }; | |
445 | ||
446 | static struct llc_station_state_trans llc_stat_dupaddr_state_trans_2 = { | |
447 | .ev = llc_stat_ev_rx_null_dsap_1_xid_r_xid_r_cnt_eq, | |
448 | .next_state = LLC_STATION_STATE_DOWN, | |
449 | .ev_actions = llc_stat_dupaddr_state_actions_2, | |
450 | }; | |
451 | ||
452 | /* state transition for LLC_STATION_EV_RX_NULL_DSAP_XID_C event */ | |
453 | static llc_station_action_t llc_stat_dupaddr_state_actions_3[] = { | |
454 | [0] = llc_station_ac_send_xid_r, | |
455 | [1] = NULL, | |
456 | }; | |
457 | ||
458 | static struct llc_station_state_trans llc_stat_dupaddr_state_trans_3 = { | |
459 | .ev = llc_stat_ev_rx_null_dsap_xid_c, | |
460 | .next_state = LLC_STATION_STATE_DUP_ADDR_CHK, | |
461 | .ev_actions = llc_stat_dupaddr_state_actions_3, | |
462 | }; | |
463 | ||
464 | /* state transition for LLC_STATION_EV_ACK_TMR_EXP_LT_RETRY_CNT_MAX_RETRY | |
465 | * event | |
466 | */ | |
467 | static llc_station_action_t llc_stat_dupaddr_state_actions_4[] = { | |
468 | [0] = llc_station_ac_start_ack_timer, | |
469 | [1] = llc_station_ac_inc_retry_cnt_by_1, | |
470 | [2] = llc_station_ac_set_xid_r_cnt_0, | |
471 | [3] = llc_station_ac_send_null_dsap_xid_c, | |
472 | [4] = NULL, | |
473 | }; | |
474 | ||
475 | static struct llc_station_state_trans llc_stat_dupaddr_state_trans_4 = { | |
476 | .ev = llc_stat_ev_ack_tmr_exp_lt_retry_cnt_max_retry, | |
477 | .next_state = LLC_STATION_STATE_DUP_ADDR_CHK, | |
478 | .ev_actions = llc_stat_dupaddr_state_actions_4, | |
479 | }; | |
480 | ||
481 | /* state transition for LLC_STATION_EV_ACK_TMR_EXP_EQ_RETRY_CNT_MAX_RETRY | |
482 | * event | |
483 | */ | |
484 | static llc_station_action_t llc_stat_dupaddr_state_actions_5[] = { | |
485 | [0] = llc_station_ac_report_status, /* STATION UP */ | |
486 | [1] = NULL, | |
487 | }; | |
488 | ||
489 | static struct llc_station_state_trans llc_stat_dupaddr_state_trans_5 = { | |
490 | .ev = llc_stat_ev_ack_tmr_exp_eq_retry_cnt_max_retry, | |
491 | .next_state = LLC_STATION_STATE_UP, | |
492 | .ev_actions = llc_stat_dupaddr_state_actions_5, | |
493 | }; | |
494 | ||
495 | /* state transition for LLC_STATION_EV_DISABLE_REQ event */ | |
496 | static llc_station_action_t llc_stat_dupaddr_state_actions_6[] = { | |
497 | [0] = llc_station_ac_report_status, /* STATION DOWN */ | |
498 | [1] = NULL, | |
499 | }; | |
500 | ||
501 | static struct llc_station_state_trans llc_stat_dupaddr_state_trans_6 = { | |
502 | .ev = llc_stat_ev_disable_req, | |
503 | .next_state = LLC_STATION_STATE_DOWN, | |
504 | .ev_actions = llc_stat_dupaddr_state_actions_6, | |
505 | }; | |
506 | ||
507 | /* array of pointers; one to each transition */ | |
508 | static struct llc_station_state_trans *llc_stat_dupaddr_state_trans[] = { | |
509 | [0] = &llc_stat_dupaddr_state_trans_6, /* Request */ | |
510 | [1] = &llc_stat_dupaddr_state_trans_4, /* Timer */ | |
511 | [2] = &llc_stat_dupaddr_state_trans_5, | |
512 | [3] = &llc_stat_dupaddr_state_trans_1, /* Receive frame */ | |
513 | [4] = &llc_stat_dupaddr_state_trans_2, | |
514 | [5] = &llc_stat_dupaddr_state_trans_3, | |
515 | [6] = &llc_stat_state_trans_end, | |
516 | }; | |
517 | ||
518 | static struct llc_station_state | |
519 | llc_station_state_table[LLC_NBR_STATION_STATES] = { | |
520 | [LLC_STATION_STATE_DOWN - 1] = { | |
521 | .curr_state = LLC_STATION_STATE_DOWN, | |
522 | .transitions = llc_stat_dwn_state_trans, | |
523 | }, | |
524 | [LLC_STATION_STATE_DUP_ADDR_CHK - 1] = { | |
525 | .curr_state = LLC_STATION_STATE_DUP_ADDR_CHK, | |
526 | .transitions = llc_stat_dupaddr_state_trans, | |
527 | }, | |
528 | [LLC_STATION_STATE_UP - 1] = { | |
529 | .curr_state = LLC_STATION_STATE_UP, | |
530 | .transitions = llc_stat_up_state_trans, | |
531 | }, | |
532 | }; | |
533 | ||
534 | /** | |
535 | * llc_exec_station_trans_actions - executes actions for transition | |
536 | * @trans: Address of the transition | |
537 | * @skb: Address of the event that caused the transition | |
538 | * | |
539 | * Executes actions of a transition of the station state machine. Returns | |
540 | * 0 if all actions complete successfully, nonzero otherwise. | |
541 | */ | |
542 | static u16 llc_exec_station_trans_actions(struct llc_station_state_trans *trans, | |
543 | struct sk_buff *skb) | |
544 | { | |
545 | u16 rc = 0; | |
546 | llc_station_action_t *next_action = trans->ev_actions; | |
547 | ||
548 | for (; next_action && *next_action; next_action++) | |
549 | if ((*next_action)(skb)) | |
550 | rc = 1; | |
551 | return rc; | |
552 | } | |
553 | ||
554 | /** | |
555 | * llc_find_station_trans - finds transition for this event | |
556 | * @skb: Address of the event | |
557 | * | |
558 | * Search thru events of the current state of the station until list | |
559 | * exhausted or it's obvious that the event is not valid for the current | |
560 | * state. Returns the address of the transition if cound, %NULL otherwise. | |
561 | */ | |
562 | static struct llc_station_state_trans * | |
563 | llc_find_station_trans(struct sk_buff *skb) | |
564 | { | |
565 | int i = 0; | |
566 | struct llc_station_state_trans *rc = NULL; | |
567 | struct llc_station_state_trans **next_trans; | |
568 | struct llc_station_state *curr_state = | |
569 | &llc_station_state_table[llc_main_station.state - 1]; | |
570 | ||
571 | for (next_trans = curr_state->transitions; next_trans[i]->ev; i++) | |
572 | if (!next_trans[i]->ev(skb)) { | |
573 | rc = next_trans[i]; | |
574 | break; | |
575 | } | |
576 | return rc; | |
577 | } | |
578 | ||
579 | /** | |
580 | * llc_station_free_ev - frees an event | |
581 | * @skb: Address of the event | |
582 | * | |
583 | * Frees an event. | |
584 | */ | |
585 | static void llc_station_free_ev(struct sk_buff *skb) | |
586 | { | |
587 | struct llc_station_state_ev *ev = llc_station_ev(skb); | |
588 | ||
589 | if (ev->type == LLC_STATION_EV_TYPE_PDU) | |
590 | kfree_skb(skb); | |
591 | } | |
592 | ||
593 | /** | |
594 | * llc_station_next_state - processes event and goes to the next state | |
595 | * @skb: Address of the event | |
596 | * | |
597 | * Processes an event, executes any transitions related to that event and | |
598 | * updates the state of the station. | |
599 | */ | |
600 | static u16 llc_station_next_state(struct sk_buff *skb) | |
601 | { | |
602 | u16 rc = 1; | |
603 | struct llc_station_state_trans *trans; | |
604 | ||
605 | if (llc_main_station.state > LLC_NBR_STATION_STATES) | |
606 | goto out; | |
607 | trans = llc_find_station_trans(skb); | |
608 | if (trans) { | |
609 | /* got the state to which we next transition; perform the | |
610 | * actions associated with this transition before actually | |
611 | * transitioning to the next state | |
612 | */ | |
613 | rc = llc_exec_station_trans_actions(trans, skb); | |
614 | if (!rc) | |
615 | /* transition station to next state if all actions | |
616 | * execute successfully; done; wait for next event | |
617 | */ | |
618 | llc_main_station.state = trans->next_state; | |
619 | } else | |
620 | /* event not recognized in current state; re-queue it for | |
621 | * processing again at a later time; return failure | |
622 | */ | |
623 | rc = 0; | |
624 | out: | |
625 | llc_station_free_ev(skb); | |
626 | return rc; | |
627 | } | |
628 | ||
629 | /** | |
630 | * llc_station_service_events - service events in the queue | |
631 | * | |
632 | * Get an event from the station event queue (if any); attempt to service | |
633 | * the event; if event serviced, get the next event (if any) on the event | |
634 | * queue; if event not service, re-queue the event on the event queue and | |
635 | * attempt to service the next event; when serviced all events in queue, | |
636 | * finished; if don't transition to different state, just service all | |
637 | * events once; if transition to new state, service all events again. | |
638 | * Caller must hold llc_main_station.ev_q.lock. | |
639 | */ | |
640 | static void llc_station_service_events(void) | |
641 | { | |
642 | struct sk_buff *skb; | |
643 | ||
644 | while ((skb = skb_dequeue(&llc_main_station.ev_q.list)) != NULL) | |
645 | llc_station_next_state(skb); | |
646 | } | |
647 | ||
648 | /** | |
649 | * llc_station_state_process: queue event and try to process queue. | |
650 | * @skb: Address of the event | |
651 | * | |
652 | * Queues an event (on the station event queue) for handling by the | |
653 | * station state machine and attempts to process any queued-up events. | |
654 | */ | |
655 | static void llc_station_state_process(struct sk_buff *skb) | |
656 | { | |
657 | spin_lock_bh(&llc_main_station.ev_q.lock); | |
658 | skb_queue_tail(&llc_main_station.ev_q.list, skb); | |
659 | llc_station_service_events(); | |
660 | spin_unlock_bh(&llc_main_station.ev_q.lock); | |
661 | } | |
662 | ||
663 | static void llc_station_ack_tmr_cb(unsigned long timeout_data) | |
664 | { | |
665 | struct sk_buff *skb = alloc_skb(0, GFP_ATOMIC); | |
666 | ||
667 | if (skb) { | |
668 | struct llc_station_state_ev *ev = llc_station_ev(skb); | |
669 | ||
670 | ev->type = LLC_STATION_EV_TYPE_ACK_TMR; | |
671 | llc_station_state_process(skb); | |
672 | } | |
673 | } | |
674 | ||
675 | /* | |
676 | * llc_station_rcv - send received pdu to the station state machine | |
677 | * @skb: received frame. | |
678 | * | |
679 | * Sends data unit to station state machine. | |
680 | */ | |
681 | static void llc_station_rcv(struct sk_buff *skb) | |
682 | { | |
683 | struct llc_station_state_ev *ev = llc_station_ev(skb); | |
684 | ||
685 | ev->type = LLC_STATION_EV_TYPE_PDU; | |
686 | ev->reason = 0; | |
687 | llc_station_state_process(skb); | |
688 | } | |
689 | ||
690 | int __init llc_station_init(void) | |
691 | { | |
692 | u16 rc = -ENOBUFS; | |
693 | struct sk_buff *skb; | |
694 | struct llc_station_state_ev *ev; | |
695 | ||
696 | skb_queue_head_init(&llc_main_station.mac_pdu_q); | |
697 | skb_queue_head_init(&llc_main_station.ev_q.list); | |
698 | spin_lock_init(&llc_main_station.ev_q.lock); | |
b24b8a24 PE |
699 | setup_timer(&llc_main_station.ack_timer, llc_station_ack_tmr_cb, |
700 | (unsigned long)&llc_main_station); | |
590232a7 ACM |
701 | llc_main_station.ack_timer.expires = jiffies + |
702 | sysctl_llc_station_ack_timeout; | |
1da177e4 LT |
703 | skb = alloc_skb(0, GFP_ATOMIC); |
704 | if (!skb) | |
705 | goto out; | |
706 | rc = 0; | |
707 | llc_set_station_handler(llc_station_rcv); | |
708 | ev = llc_station_ev(skb); | |
709 | memset(ev, 0, sizeof(*ev)); | |
1da177e4 LT |
710 | llc_main_station.maximum_retry = 1; |
711 | llc_main_station.state = LLC_STATION_STATE_DOWN; | |
712 | ev->type = LLC_STATION_EV_TYPE_SIMPLE; | |
713 | ev->prim_type = LLC_STATION_EV_ENABLE_WITHOUT_DUP_ADDR_CHECK; | |
714 | rc = llc_station_next_state(skb); | |
715 | out: | |
716 | return rc; | |
717 | } | |
718 | ||
719 | void __exit llc_station_exit(void) | |
720 | { | |
721 | llc_set_station_handler(NULL); | |
722 | } |