]>
Commit | Line | Data |
---|---|---|
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> | |
16 | #include <net/llc.h> | |
17 | #include <net/llc_sap.h> | |
18 | #include <net/llc_conn.h> | |
19 | #include <net/llc_c_ac.h> | |
20 | #include <net/llc_s_ac.h> | |
21 | #include <net/llc_c_ev.h> | |
22 | #include <net/llc_c_st.h> | |
23 | #include <net/llc_s_ev.h> | |
24 | #include <net/llc_s_st.h> | |
25 | #include <net/llc_pdu.h> | |
26 | ||
27 | /** | |
28 | * struct llc_station - LLC station component | |
29 | * | |
30 | * SAP and connection resource manager, one per adapter. | |
31 | * | |
32 | * @state - state of station | |
33 | * @xid_r_count - XID response PDU counter | |
34 | * @mac_sa - MAC source address | |
35 | * @sap_list - list of related SAPs | |
36 | * @ev_q - events entering state mach. | |
37 | * @mac_pdu_q - PDUs ready to send to MAC | |
38 | */ | |
39 | struct llc_station { | |
40 | u8 state; | |
41 | u8 xid_r_count; | |
42 | struct timer_list ack_timer; | |
43 | u8 retry_count; | |
44 | u8 maximum_retry; | |
45 | struct { | |
46 | struct sk_buff_head list; | |
47 | spinlock_t lock; | |
48 | } ev_q; | |
49 | struct sk_buff_head mac_pdu_q; | |
50 | }; | |
51 | ||
590232a7 ACM |
52 | #define LLC_STATION_ACK_TIME (3 * HZ) |
53 | ||
54 | int sysctl_llc_station_ack_timeout = LLC_STATION_ACK_TIME; | |
55 | ||
1da177e4 LT |
56 | /* Types of events (possible values in 'ev->type') */ |
57 | #define LLC_STATION_EV_TYPE_SIMPLE 1 | |
58 | #define LLC_STATION_EV_TYPE_CONDITION 2 | |
59 | #define LLC_STATION_EV_TYPE_PRIM 3 | |
60 | #define LLC_STATION_EV_TYPE_PDU 4 /* command/response PDU */ | |
61 | #define LLC_STATION_EV_TYPE_ACK_TMR 5 | |
62 | #define LLC_STATION_EV_TYPE_RPT_STATUS 6 | |
63 | ||
64 | /* Events */ | |
65 | #define LLC_STATION_EV_ENABLE_WITH_DUP_ADDR_CHECK 1 | |
66 | #define LLC_STATION_EV_ENABLE_WITHOUT_DUP_ADDR_CHECK 2 | |
67 | #define LLC_STATION_EV_ACK_TMR_EXP_LT_RETRY_CNT_MAX_RETRY 3 | |
68 | #define LLC_STATION_EV_ACK_TMR_EXP_EQ_RETRY_CNT_MAX_RETRY 4 | |
69 | #define LLC_STATION_EV_RX_NULL_DSAP_XID_C 5 | |
70 | #define LLC_STATION_EV_RX_NULL_DSAP_0_XID_R_XID_R_CNT_EQ 6 | |
71 | #define LLC_STATION_EV_RX_NULL_DSAP_1_XID_R_XID_R_CNT_EQ 7 | |
72 | #define LLC_STATION_EV_RX_NULL_DSAP_TEST_C 8 | |
73 | #define LLC_STATION_EV_DISABLE_REQ 9 | |
74 | ||
75 | struct llc_station_state_ev { | |
76 | u8 type; | |
77 | u8 prim; | |
78 | u8 prim_type; | |
79 | u8 reason; | |
80 | struct list_head node; /* node in station->ev_q.list */ | |
81 | }; | |
82 | ||
83 | static __inline__ struct llc_station_state_ev * | |
84 | llc_station_ev(struct sk_buff *skb) | |
85 | { | |
86 | return (struct llc_station_state_ev *)skb->cb; | |
87 | } | |
88 | ||
89 | typedef int (*llc_station_ev_t)(struct sk_buff *skb); | |
90 | ||
91 | #define LLC_STATION_STATE_DOWN 1 /* initial state */ | |
92 | #define LLC_STATION_STATE_DUP_ADDR_CHK 2 | |
93 | #define LLC_STATION_STATE_UP 3 | |
94 | ||
95 | #define LLC_NBR_STATION_STATES 3 /* size of state table */ | |
96 | ||
97 | typedef int (*llc_station_action_t)(struct sk_buff *skb); | |
98 | ||
99 | /* Station component state table structure */ | |
100 | struct llc_station_state_trans { | |
101 | llc_station_ev_t ev; | |
102 | u8 next_state; | |
103 | llc_station_action_t *ev_actions; | |
104 | }; | |
105 | ||
106 | struct llc_station_state { | |
107 | u8 curr_state; | |
108 | struct llc_station_state_trans **transitions; | |
109 | }; | |
110 | ||
111 | static struct llc_station llc_main_station; | |
112 | ||
113 | static int llc_stat_ev_enable_with_dup_addr_check(struct sk_buff *skb) | |
114 | { | |
d57b1869 YH |
115 | struct llc_station_state_ev *ev = llc_station_ev(skb); |
116 | ||
1da177e4 LT |
117 | return ev->type == LLC_STATION_EV_TYPE_SIMPLE && |
118 | ev->prim_type == | |
d57b1869 | 119 | LLC_STATION_EV_ENABLE_WITH_DUP_ADDR_CHECK ? 0 : 1; |
1da177e4 LT |
120 | } |
121 | ||
122 | static int llc_stat_ev_enable_without_dup_addr_check(struct sk_buff *skb) | |
123 | { | |
d57b1869 YH |
124 | struct llc_station_state_ev *ev = llc_station_ev(skb); |
125 | ||
1da177e4 LT |
126 | return ev->type == LLC_STATION_EV_TYPE_SIMPLE && |
127 | ev->prim_type == | |
128 | LLC_STATION_EV_ENABLE_WITHOUT_DUP_ADDR_CHECK ? 0 : 1; | |
129 | } | |
130 | ||
131 | static int llc_stat_ev_ack_tmr_exp_lt_retry_cnt_max_retry(struct sk_buff *skb) | |
132 | { | |
d57b1869 YH |
133 | struct llc_station_state_ev *ev = llc_station_ev(skb); |
134 | ||
1da177e4 LT |
135 | return ev->type == LLC_STATION_EV_TYPE_ACK_TMR && |
136 | llc_main_station.retry_count < | |
137 | llc_main_station.maximum_retry ? 0 : 1; | |
138 | } | |
139 | ||
140 | static int llc_stat_ev_ack_tmr_exp_eq_retry_cnt_max_retry(struct sk_buff *skb) | |
141 | { | |
d57b1869 YH |
142 | struct llc_station_state_ev *ev = llc_station_ev(skb); |
143 | ||
1da177e4 LT |
144 | return ev->type == LLC_STATION_EV_TYPE_ACK_TMR && |
145 | llc_main_station.retry_count == | |
146 | llc_main_station.maximum_retry ? 0 : 1; | |
147 | } | |
148 | ||
149 | static int llc_stat_ev_rx_null_dsap_xid_c(struct sk_buff *skb) | |
150 | { | |
d57b1869 | 151 | struct llc_station_state_ev *ev = llc_station_ev(skb); |
1da177e4 LT |
152 | struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb); |
153 | ||
154 | return ev->type == LLC_STATION_EV_TYPE_PDU && | |
155 | LLC_PDU_IS_CMD(pdu) && /* command PDU */ | |
156 | LLC_PDU_TYPE_IS_U(pdu) && /* U type PDU */ | |
157 | LLC_U_PDU_CMD(pdu) == LLC_1_PDU_CMD_XID && | |
158 | !pdu->dsap ? 0 : 1; /* NULL DSAP value */ | |
159 | } | |
160 | ||
161 | static int llc_stat_ev_rx_null_dsap_0_xid_r_xid_r_cnt_eq(struct sk_buff *skb) | |
162 | { | |
163 | struct llc_station_state_ev *ev = llc_station_ev(skb); | |
164 | struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb); | |
165 | ||
166 | return ev->type == LLC_STATION_EV_TYPE_PDU && | |
167 | LLC_PDU_IS_RSP(pdu) && /* response PDU */ | |
168 | LLC_PDU_TYPE_IS_U(pdu) && /* U type PDU */ | |
169 | LLC_U_PDU_RSP(pdu) == LLC_1_PDU_CMD_XID && | |
170 | !pdu->dsap && /* NULL DSAP value */ | |
171 | !llc_main_station.xid_r_count ? 0 : 1; | |
172 | } | |
173 | ||
174 | static int llc_stat_ev_rx_null_dsap_1_xid_r_xid_r_cnt_eq(struct sk_buff *skb) | |
175 | { | |
176 | struct llc_station_state_ev *ev = llc_station_ev(skb); | |
177 | struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb); | |
178 | ||
179 | return ev->type == LLC_STATION_EV_TYPE_PDU && | |
180 | LLC_PDU_IS_RSP(pdu) && /* response PDU */ | |
181 | LLC_PDU_TYPE_IS_U(pdu) && /* U type PDU */ | |
182 | LLC_U_PDU_RSP(pdu) == LLC_1_PDU_CMD_XID && | |
183 | !pdu->dsap && /* NULL DSAP value */ | |
184 | llc_main_station.xid_r_count == 1 ? 0 : 1; | |
185 | } | |
186 | ||
187 | static int llc_stat_ev_rx_null_dsap_test_c(struct sk_buff *skb) | |
188 | { | |
189 | struct llc_station_state_ev *ev = llc_station_ev(skb); | |
190 | struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb); | |
191 | ||
192 | return ev->type == LLC_STATION_EV_TYPE_PDU && | |
193 | LLC_PDU_IS_CMD(pdu) && /* command PDU */ | |
194 | LLC_PDU_TYPE_IS_U(pdu) && /* U type PDU */ | |
195 | LLC_U_PDU_CMD(pdu) == LLC_1_PDU_CMD_TEST && | |
196 | !pdu->dsap ? 0 : 1; /* NULL DSAP */ | |
197 | } | |
198 | ||
199 | static int llc_stat_ev_disable_req(struct sk_buff *skb) | |
200 | { | |
201 | struct llc_station_state_ev *ev = llc_station_ev(skb); | |
202 | ||
203 | return ev->type == LLC_STATION_EV_TYPE_PRIM && | |
204 | ev->prim == LLC_DISABLE_PRIM && | |
205 | ev->prim_type == LLC_PRIM_TYPE_REQ ? 0 : 1; | |
206 | } | |
207 | ||
208 | /** | |
209 | * llc_station_send_pdu - queues PDU to send | |
210 | * @skb: Address of the PDU | |
211 | * | |
212 | * Queues a PDU to send to the MAC layer. | |
213 | */ | |
214 | static void llc_station_send_pdu(struct sk_buff *skb) | |
215 | { | |
216 | skb_queue_tail(&llc_main_station.mac_pdu_q, skb); | |
217 | while ((skb = skb_dequeue(&llc_main_station.mac_pdu_q)) != NULL) | |
218 | if (dev_queue_xmit(skb)) | |
219 | break; | |
220 | } | |
221 | ||
222 | static int llc_station_ac_start_ack_timer(struct sk_buff *skb) | |
223 | { | |
590232a7 ACM |
224 | mod_timer(&llc_main_station.ack_timer, |
225 | jiffies + sysctl_llc_station_ack_timeout); | |
1da177e4 LT |
226 | return 0; |
227 | } | |
228 | ||
229 | static int llc_station_ac_set_retry_cnt_0(struct sk_buff *skb) | |
230 | { | |
231 | llc_main_station.retry_count = 0; | |
232 | return 0; | |
233 | } | |
234 | ||
235 | static int llc_station_ac_inc_retry_cnt_by_1(struct sk_buff *skb) | |
236 | { | |
237 | llc_main_station.retry_count++; | |
238 | return 0; | |
239 | } | |
240 | ||
241 | static int llc_station_ac_set_xid_r_cnt_0(struct sk_buff *skb) | |
242 | { | |
243 | llc_main_station.xid_r_count = 0; | |
244 | return 0; | |
245 | } | |
246 | ||
247 | static int llc_station_ac_inc_xid_r_cnt_by_1(struct sk_buff *skb) | |
248 | { | |
249 | llc_main_station.xid_r_count++; | |
250 | return 0; | |
251 | } | |
252 | ||
253 | static int llc_station_ac_send_null_dsap_xid_c(struct sk_buff *skb) | |
254 | { | |
255 | int rc = 1; | |
f83f1768 JP |
256 | struct sk_buff *nskb = llc_alloc_frame(NULL, skb->dev, LLC_PDU_TYPE_U, |
257 | sizeof(struct llc_xid_info)); | |
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); | |
a5a04819 | 263 | rc = llc_mac_hdr_init(nskb, skb->dev->dev_addr, skb->dev->dev_addr); |
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; | |
f83f1768 JP |
278 | struct sk_buff *nskb = llc_alloc_frame(NULL, skb->dev, LLC_PDU_TYPE_U, |
279 | sizeof(struct llc_xid_info)); | |
1da177e4 LT |
280 | |
281 | if (!nskb) | |
282 | goto out; | |
283 | rc = 0; | |
1da177e4 LT |
284 | llc_pdu_decode_sa(skb, mac_da); |
285 | llc_pdu_decode_ssap(skb, &dsap); | |
286 | llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, 0, dsap, LLC_PDU_RSP); | |
287 | llc_pdu_init_as_xid_rsp(nskb, LLC_XID_NULL_CLASS_2, 127); | |
a5a04819 | 288 | rc = llc_mac_hdr_init(nskb, skb->dev->dev_addr, mac_da); |
249ff1c6 | 289 | if (unlikely(rc)) |
1da177e4 LT |
290 | goto free; |
291 | llc_station_send_pdu(nskb); | |
292 | out: | |
293 | return rc; | |
294 | free: | |
295 | kfree_skb(skb); | |
296 | goto out; | |
297 | } | |
298 | ||
299 | static int llc_station_ac_send_test_r(struct sk_buff *skb) | |
300 | { | |
301 | u8 mac_da[ETH_ALEN], dsap; | |
302 | int rc = 1; | |
f83f1768 JP |
303 | u32 data_size; |
304 | struct sk_buff *nskb; | |
305 | ||
306 | /* The test request command is type U (llc_len = 3) */ | |
307 | data_size = ntohs(eth_hdr(skb)->h_proto) - 3; | |
308 | nskb = llc_alloc_frame(NULL, skb->dev, LLC_PDU_TYPE_U, data_size); | |
1da177e4 LT |
309 | |
310 | if (!nskb) | |
311 | goto out; | |
312 | rc = 0; | |
1da177e4 LT |
313 | llc_pdu_decode_sa(skb, mac_da); |
314 | llc_pdu_decode_ssap(skb, &dsap); | |
315 | llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, 0, dsap, LLC_PDU_RSP); | |
d57b1869 | 316 | llc_pdu_init_as_test_rsp(nskb, skb); |
a5a04819 | 317 | rc = llc_mac_hdr_init(nskb, skb->dev->dev_addr, mac_da); |
249ff1c6 | 318 | if (unlikely(rc)) |
1da177e4 LT |
319 | goto free; |
320 | llc_station_send_pdu(nskb); | |
321 | out: | |
322 | return rc; | |
323 | free: | |
324 | kfree_skb(skb); | |
325 | goto out; | |
326 | } | |
327 | ||
328 | static int llc_station_ac_report_status(struct sk_buff *skb) | |
329 | { | |
330 | return 0; | |
331 | } | |
332 | ||
333 | /* COMMON STATION STATE transitions */ | |
334 | ||
335 | /* dummy last-transition indicator; common to all state transition groups | |
336 | * last entry for this state | |
337 | * all members are zeros, .bss zeroes it | |
338 | */ | |
339 | static struct llc_station_state_trans llc_stat_state_trans_end; | |
340 | ||
341 | /* DOWN STATE transitions */ | |
342 | ||
343 | /* state transition for LLC_STATION_EV_ENABLE_WITH_DUP_ADDR_CHECK event */ | |
344 | static llc_station_action_t llc_stat_down_state_actions_1[] = { | |
345 | [0] = llc_station_ac_start_ack_timer, | |
346 | [1] = llc_station_ac_set_retry_cnt_0, | |
347 | [2] = llc_station_ac_set_xid_r_cnt_0, | |
348 | [3] = llc_station_ac_send_null_dsap_xid_c, | |
349 | [4] = NULL, | |
350 | }; | |
351 | ||
352 | static struct llc_station_state_trans llc_stat_down_state_trans_1 = { | |
353 | .ev = llc_stat_ev_enable_with_dup_addr_check, | |
354 | .next_state = LLC_STATION_STATE_DUP_ADDR_CHK, | |
355 | .ev_actions = llc_stat_down_state_actions_1, | |
356 | }; | |
357 | ||
358 | /* state transition for LLC_STATION_EV_ENABLE_WITHOUT_DUP_ADDR_CHECK event */ | |
359 | static llc_station_action_t llc_stat_down_state_actions_2[] = { | |
360 | [0] = llc_station_ac_report_status, /* STATION UP */ | |
361 | [1] = NULL, | |
362 | }; | |
363 | ||
364 | static struct llc_station_state_trans llc_stat_down_state_trans_2 = { | |
365 | .ev = llc_stat_ev_enable_without_dup_addr_check, | |
366 | .next_state = LLC_STATION_STATE_UP, | |
367 | .ev_actions = llc_stat_down_state_actions_2, | |
368 | }; | |
369 | ||
370 | /* array of pointers; one to each transition */ | |
371 | static struct llc_station_state_trans *llc_stat_dwn_state_trans[] = { | |
372 | [0] = &llc_stat_down_state_trans_1, | |
373 | [1] = &llc_stat_down_state_trans_2, | |
374 | [2] = &llc_stat_state_trans_end, | |
375 | }; | |
376 | ||
377 | /* UP STATE transitions */ | |
378 | /* state transition for LLC_STATION_EV_DISABLE_REQ event */ | |
379 | static llc_station_action_t llc_stat_up_state_actions_1[] = { | |
380 | [0] = llc_station_ac_report_status, /* STATION DOWN */ | |
381 | [1] = NULL, | |
382 | }; | |
383 | ||
384 | static struct llc_station_state_trans llc_stat_up_state_trans_1 = { | |
385 | .ev = llc_stat_ev_disable_req, | |
386 | .next_state = LLC_STATION_STATE_DOWN, | |
387 | .ev_actions = llc_stat_up_state_actions_1, | |
388 | }; | |
389 | ||
390 | /* state transition for LLC_STATION_EV_RX_NULL_DSAP_XID_C event */ | |
391 | static llc_station_action_t llc_stat_up_state_actions_2[] = { | |
392 | [0] = llc_station_ac_send_xid_r, | |
393 | [1] = NULL, | |
394 | }; | |
395 | ||
396 | static struct llc_station_state_trans llc_stat_up_state_trans_2 = { | |
397 | .ev = llc_stat_ev_rx_null_dsap_xid_c, | |
398 | .next_state = LLC_STATION_STATE_UP, | |
399 | .ev_actions = llc_stat_up_state_actions_2, | |
400 | }; | |
401 | ||
402 | /* state transition for LLC_STATION_EV_RX_NULL_DSAP_TEST_C event */ | |
403 | static llc_station_action_t llc_stat_up_state_actions_3[] = { | |
404 | [0] = llc_station_ac_send_test_r, | |
405 | [1] = NULL, | |
406 | }; | |
407 | ||
408 | static struct llc_station_state_trans llc_stat_up_state_trans_3 = { | |
409 | .ev = llc_stat_ev_rx_null_dsap_test_c, | |
410 | .next_state = LLC_STATION_STATE_UP, | |
411 | .ev_actions = llc_stat_up_state_actions_3, | |
412 | }; | |
413 | ||
414 | /* array of pointers; one to each transition */ | |
415 | static struct llc_station_state_trans *llc_stat_up_state_trans [] = { | |
416 | [0] = &llc_stat_up_state_trans_1, | |
417 | [1] = &llc_stat_up_state_trans_2, | |
418 | [2] = &llc_stat_up_state_trans_3, | |
419 | [3] = &llc_stat_state_trans_end, | |
420 | }; | |
421 | ||
422 | /* DUP ADDR CHK STATE transitions */ | |
423 | /* state transition for LLC_STATION_EV_RX_NULL_DSAP_0_XID_R_XID_R_CNT_EQ | |
424 | * event | |
425 | */ | |
426 | static llc_station_action_t llc_stat_dupaddr_state_actions_1[] = { | |
427 | [0] = llc_station_ac_inc_xid_r_cnt_by_1, | |
428 | [1] = NULL, | |
429 | }; | |
430 | ||
431 | static struct llc_station_state_trans llc_stat_dupaddr_state_trans_1 = { | |
432 | .ev = llc_stat_ev_rx_null_dsap_0_xid_r_xid_r_cnt_eq, | |
433 | .next_state = LLC_STATION_STATE_DUP_ADDR_CHK, | |
434 | .ev_actions = llc_stat_dupaddr_state_actions_1, | |
435 | }; | |
436 | ||
437 | /* state transition for LLC_STATION_EV_RX_NULL_DSAP_1_XID_R_XID_R_CNT_EQ | |
438 | * event | |
439 | */ | |
440 | static llc_station_action_t llc_stat_dupaddr_state_actions_2[] = { | |
441 | [0] = llc_station_ac_report_status, /* DUPLICATE ADDRESS FOUND */ | |
442 | [1] = NULL, | |
443 | }; | |
444 | ||
445 | static struct llc_station_state_trans llc_stat_dupaddr_state_trans_2 = { | |
446 | .ev = llc_stat_ev_rx_null_dsap_1_xid_r_xid_r_cnt_eq, | |
447 | .next_state = LLC_STATION_STATE_DOWN, | |
448 | .ev_actions = llc_stat_dupaddr_state_actions_2, | |
449 | }; | |
450 | ||
451 | /* state transition for LLC_STATION_EV_RX_NULL_DSAP_XID_C event */ | |
452 | static llc_station_action_t llc_stat_dupaddr_state_actions_3[] = { | |
453 | [0] = llc_station_ac_send_xid_r, | |
454 | [1] = NULL, | |
455 | }; | |
456 | ||
457 | static struct llc_station_state_trans llc_stat_dupaddr_state_trans_3 = { | |
458 | .ev = llc_stat_ev_rx_null_dsap_xid_c, | |
459 | .next_state = LLC_STATION_STATE_DUP_ADDR_CHK, | |
460 | .ev_actions = llc_stat_dupaddr_state_actions_3, | |
461 | }; | |
462 | ||
463 | /* state transition for LLC_STATION_EV_ACK_TMR_EXP_LT_RETRY_CNT_MAX_RETRY | |
464 | * event | |
465 | */ | |
466 | static llc_station_action_t llc_stat_dupaddr_state_actions_4[] = { | |
467 | [0] = llc_station_ac_start_ack_timer, | |
468 | [1] = llc_station_ac_inc_retry_cnt_by_1, | |
469 | [2] = llc_station_ac_set_xid_r_cnt_0, | |
470 | [3] = llc_station_ac_send_null_dsap_xid_c, | |
471 | [4] = NULL, | |
472 | }; | |
473 | ||
474 | static struct llc_station_state_trans llc_stat_dupaddr_state_trans_4 = { | |
475 | .ev = llc_stat_ev_ack_tmr_exp_lt_retry_cnt_max_retry, | |
476 | .next_state = LLC_STATION_STATE_DUP_ADDR_CHK, | |
477 | .ev_actions = llc_stat_dupaddr_state_actions_4, | |
478 | }; | |
479 | ||
480 | /* state transition for LLC_STATION_EV_ACK_TMR_EXP_EQ_RETRY_CNT_MAX_RETRY | |
481 | * event | |
482 | */ | |
483 | static llc_station_action_t llc_stat_dupaddr_state_actions_5[] = { | |
484 | [0] = llc_station_ac_report_status, /* STATION UP */ | |
485 | [1] = NULL, | |
486 | }; | |
487 | ||
488 | static struct llc_station_state_trans llc_stat_dupaddr_state_trans_5 = { | |
489 | .ev = llc_stat_ev_ack_tmr_exp_eq_retry_cnt_max_retry, | |
490 | .next_state = LLC_STATION_STATE_UP, | |
491 | .ev_actions = llc_stat_dupaddr_state_actions_5, | |
492 | }; | |
493 | ||
494 | /* state transition for LLC_STATION_EV_DISABLE_REQ event */ | |
495 | static llc_station_action_t llc_stat_dupaddr_state_actions_6[] = { | |
496 | [0] = llc_station_ac_report_status, /* STATION DOWN */ | |
497 | [1] = NULL, | |
498 | }; | |
499 | ||
500 | static struct llc_station_state_trans llc_stat_dupaddr_state_trans_6 = { | |
501 | .ev = llc_stat_ev_disable_req, | |
502 | .next_state = LLC_STATION_STATE_DOWN, | |
503 | .ev_actions = llc_stat_dupaddr_state_actions_6, | |
504 | }; | |
505 | ||
506 | /* array of pointers; one to each transition */ | |
507 | static struct llc_station_state_trans *llc_stat_dupaddr_state_trans[] = { | |
508 | [0] = &llc_stat_dupaddr_state_trans_6, /* Request */ | |
509 | [1] = &llc_stat_dupaddr_state_trans_4, /* Timer */ | |
510 | [2] = &llc_stat_dupaddr_state_trans_5, | |
511 | [3] = &llc_stat_dupaddr_state_trans_1, /* Receive frame */ | |
512 | [4] = &llc_stat_dupaddr_state_trans_2, | |
513 | [5] = &llc_stat_dupaddr_state_trans_3, | |
514 | [6] = &llc_stat_state_trans_end, | |
515 | }; | |
516 | ||
517 | static struct llc_station_state | |
518 | llc_station_state_table[LLC_NBR_STATION_STATES] = { | |
519 | [LLC_STATION_STATE_DOWN - 1] = { | |
520 | .curr_state = LLC_STATION_STATE_DOWN, | |
521 | .transitions = llc_stat_dwn_state_trans, | |
522 | }, | |
523 | [LLC_STATION_STATE_DUP_ADDR_CHK - 1] = { | |
524 | .curr_state = LLC_STATION_STATE_DUP_ADDR_CHK, | |
525 | .transitions = llc_stat_dupaddr_state_trans, | |
526 | }, | |
527 | [LLC_STATION_STATE_UP - 1] = { | |
528 | .curr_state = LLC_STATION_STATE_UP, | |
529 | .transitions = llc_stat_up_state_trans, | |
530 | }, | |
531 | }; | |
532 | ||
533 | /** | |
534 | * llc_exec_station_trans_actions - executes actions for transition | |
535 | * @trans: Address of the transition | |
536 | * @skb: Address of the event that caused the transition | |
537 | * | |
538 | * Executes actions of a transition of the station state machine. Returns | |
539 | * 0 if all actions complete successfully, nonzero otherwise. | |
540 | */ | |
541 | static u16 llc_exec_station_trans_actions(struct llc_station_state_trans *trans, | |
542 | struct sk_buff *skb) | |
543 | { | |
544 | u16 rc = 0; | |
545 | llc_station_action_t *next_action = trans->ev_actions; | |
546 | ||
547 | for (; next_action && *next_action; next_action++) | |
548 | if ((*next_action)(skb)) | |
549 | rc = 1; | |
550 | return rc; | |
551 | } | |
552 | ||
553 | /** | |
554 | * llc_find_station_trans - finds transition for this event | |
555 | * @skb: Address of the event | |
556 | * | |
557 | * Search thru events of the current state of the station until list | |
558 | * exhausted or it's obvious that the event is not valid for the current | |
559 | * state. Returns the address of the transition if cound, %NULL otherwise. | |
560 | */ | |
561 | static struct llc_station_state_trans * | |
562 | llc_find_station_trans(struct sk_buff *skb) | |
563 | { | |
564 | int i = 0; | |
565 | struct llc_station_state_trans *rc = NULL; | |
566 | struct llc_station_state_trans **next_trans; | |
567 | struct llc_station_state *curr_state = | |
568 | &llc_station_state_table[llc_main_station.state - 1]; | |
569 | ||
570 | for (next_trans = curr_state->transitions; next_trans[i]->ev; i++) | |
571 | if (!next_trans[i]->ev(skb)) { | |
572 | rc = next_trans[i]; | |
573 | break; | |
574 | } | |
575 | return rc; | |
576 | } | |
577 | ||
578 | /** | |
579 | * llc_station_free_ev - frees an event | |
580 | * @skb: Address of the event | |
581 | * | |
582 | * Frees an event. | |
583 | */ | |
584 | static void llc_station_free_ev(struct sk_buff *skb) | |
585 | { | |
586 | struct llc_station_state_ev *ev = llc_station_ev(skb); | |
587 | ||
588 | if (ev->type == LLC_STATION_EV_TYPE_PDU) | |
589 | kfree_skb(skb); | |
590 | } | |
591 | ||
592 | /** | |
593 | * llc_station_next_state - processes event and goes to the next state | |
594 | * @skb: Address of the event | |
595 | * | |
596 | * Processes an event, executes any transitions related to that event and | |
597 | * updates the state of the station. | |
598 | */ | |
599 | static u16 llc_station_next_state(struct sk_buff *skb) | |
600 | { | |
601 | u16 rc = 1; | |
602 | struct llc_station_state_trans *trans; | |
603 | ||
604 | if (llc_main_station.state > LLC_NBR_STATION_STATES) | |
605 | goto out; | |
606 | trans = llc_find_station_trans(skb); | |
607 | if (trans) { | |
608 | /* got the state to which we next transition; perform the | |
609 | * actions associated with this transition before actually | |
610 | * transitioning to the next state | |
611 | */ | |
612 | rc = llc_exec_station_trans_actions(trans, skb); | |
613 | if (!rc) | |
614 | /* transition station to next state if all actions | |
615 | * execute successfully; done; wait for next event | |
616 | */ | |
617 | llc_main_station.state = trans->next_state; | |
618 | } else | |
619 | /* event not recognized in current state; re-queue it for | |
620 | * processing again at a later time; return failure | |
621 | */ | |
622 | rc = 0; | |
623 | out: | |
624 | llc_station_free_ev(skb); | |
625 | return rc; | |
626 | } | |
627 | ||
628 | /** | |
629 | * llc_station_service_events - service events in the queue | |
630 | * | |
631 | * Get an event from the station event queue (if any); attempt to service | |
632 | * the event; if event serviced, get the next event (if any) on the event | |
633 | * queue; if event not service, re-queue the event on the event queue and | |
634 | * attempt to service the next event; when serviced all events in queue, | |
635 | * finished; if don't transition to different state, just service all | |
636 | * events once; if transition to new state, service all events again. | |
637 | * Caller must hold llc_main_station.ev_q.lock. | |
638 | */ | |
639 | static void llc_station_service_events(void) | |
640 | { | |
641 | struct sk_buff *skb; | |
642 | ||
643 | while ((skb = skb_dequeue(&llc_main_station.ev_q.list)) != NULL) | |
644 | llc_station_next_state(skb); | |
645 | } | |
646 | ||
647 | /** | |
648 | * llc_station_state_process: queue event and try to process queue. | |
649 | * @skb: Address of the event | |
650 | * | |
651 | * Queues an event (on the station event queue) for handling by the | |
652 | * station state machine and attempts to process any queued-up events. | |
653 | */ | |
654 | static void llc_station_state_process(struct sk_buff *skb) | |
655 | { | |
656 | spin_lock_bh(&llc_main_station.ev_q.lock); | |
657 | skb_queue_tail(&llc_main_station.ev_q.list, skb); | |
658 | llc_station_service_events(); | |
659 | spin_unlock_bh(&llc_main_station.ev_q.lock); | |
660 | } | |
661 | ||
662 | static void llc_station_ack_tmr_cb(unsigned long timeout_data) | |
663 | { | |
664 | struct sk_buff *skb = alloc_skb(0, GFP_ATOMIC); | |
665 | ||
666 | if (skb) { | |
667 | struct llc_station_state_ev *ev = llc_station_ev(skb); | |
668 | ||
669 | ev->type = LLC_STATION_EV_TYPE_ACK_TMR; | |
670 | llc_station_state_process(skb); | |
671 | } | |
672 | } | |
673 | ||
674 | /* | |
675 | * llc_station_rcv - send received pdu to the station state machine | |
676 | * @skb: received frame. | |
677 | * | |
678 | * Sends data unit to station state machine. | |
679 | */ | |
680 | static void llc_station_rcv(struct sk_buff *skb) | |
681 | { | |
682 | struct llc_station_state_ev *ev = llc_station_ev(skb); | |
683 | ||
684 | ev->type = LLC_STATION_EV_TYPE_PDU; | |
685 | ev->reason = 0; | |
686 | llc_station_state_process(skb); | |
687 | } | |
688 | ||
689 | int __init llc_station_init(void) | |
690 | { | |
691 | u16 rc = -ENOBUFS; | |
692 | struct sk_buff *skb; | |
693 | struct llc_station_state_ev *ev; | |
694 | ||
695 | skb_queue_head_init(&llc_main_station.mac_pdu_q); | |
696 | skb_queue_head_init(&llc_main_station.ev_q.list); | |
697 | spin_lock_init(&llc_main_station.ev_q.lock); | |
b24b8a24 PE |
698 | setup_timer(&llc_main_station.ack_timer, llc_station_ack_tmr_cb, |
699 | (unsigned long)&llc_main_station); | |
590232a7 ACM |
700 | llc_main_station.ack_timer.expires = jiffies + |
701 | sysctl_llc_station_ack_timeout; | |
1da177e4 LT |
702 | skb = alloc_skb(0, GFP_ATOMIC); |
703 | if (!skb) | |
704 | goto out; | |
705 | rc = 0; | |
706 | llc_set_station_handler(llc_station_rcv); | |
707 | ev = llc_station_ev(skb); | |
708 | memset(ev, 0, sizeof(*ev)); | |
1da177e4 LT |
709 | llc_main_station.maximum_retry = 1; |
710 | llc_main_station.state = LLC_STATION_STATE_DOWN; | |
711 | ev->type = LLC_STATION_EV_TYPE_SIMPLE; | |
712 | ev->prim_type = LLC_STATION_EV_ENABLE_WITHOUT_DUP_ADDR_CHECK; | |
713 | rc = llc_station_next_state(skb); | |
714 | out: | |
715 | return rc; | |
716 | } | |
717 | ||
718 | void __exit llc_station_exit(void) | |
719 | { | |
720 | llc_set_station_handler(NULL); | |
721 | } |