Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
Arnaldo Carvalho de Melo | 590232a | 2005-09-22 04:30:44 -0300 | [diff] [blame] | 53 | #define LLC_STATION_ACK_TIME (3 * HZ) |
| 54 | |
| 55 | int sysctl_llc_station_ack_timeout = LLC_STATION_ACK_TIME; |
| 56 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | { |
Arnaldo Carvalho de Melo | 590232a | 2005-09-22 04:30:44 -0300 | [diff] [blame] | 225 | mod_timer(&llc_main_station.ack_timer, |
| 226 | jiffies + sysctl_llc_station_ack_timeout); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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; |
Arnaldo Carvalho de Melo | 1d67e65 | 2005-09-22 03:27:56 -0300 | [diff] [blame] | 257 | struct sk_buff *nskb = llc_alloc_frame(skb->dev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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); |
Arnaldo Carvalho de Melo | 249ff1c | 2005-09-22 04:32:10 -0300 | [diff] [blame] | 264 | if (unlikely(rc)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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; |
Arnaldo Carvalho de Melo | 1d67e65 | 2005-09-22 03:27:56 -0300 | [diff] [blame] | 278 | struct sk_buff* nskb = llc_alloc_frame(skb->dev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 279 | |
| 280 | if (!nskb) |
| 281 | goto out; |
| 282 | rc = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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); |
Arnaldo Carvalho de Melo | 249ff1c | 2005-09-22 04:32:10 -0300 | [diff] [blame] | 288 | if (unlikely(rc)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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; |
Arnaldo Carvalho de Melo | 1d67e65 | 2005-09-22 03:27:56 -0300 | [diff] [blame] | 302 | struct sk_buff *nskb = llc_alloc_frame(skb->dev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 303 | |
| 304 | if (!nskb) |
| 305 | goto out; |
| 306 | rc = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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); |
Arnaldo Carvalho de Melo | 249ff1c | 2005-09-22 04:32:10 -0300 | [diff] [blame] | 312 | if (unlikely(rc)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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; |
Arnaldo Carvalho de Melo | 590232a | 2005-09-22 04:30:44 -0300 | [diff] [blame] | 695 | llc_main_station.ack_timer.expires = jiffies + |
| 696 | sysctl_llc_station_ack_timeout; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | } |