Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * llc_conn.c - Driver routines for connection component. | |
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 | ||
15 | #include <linux/init.h> | |
16 | #include <net/llc_sap.h> | |
17 | #include <net/llc_conn.h> | |
18 | #include <net/sock.h> | |
c752f073 | 19 | #include <net/tcp_states.h> |
1da177e4 LT |
20 | #include <net/llc_c_ev.h> |
21 | #include <net/llc_c_ac.h> | |
22 | #include <net/llc_c_st.h> | |
23 | #include <net/llc_pdu.h> | |
24 | ||
25 | #if 0 | |
26 | #define dprintk(args...) printk(KERN_DEBUG args) | |
27 | #else | |
28 | #define dprintk(args...) | |
29 | #endif | |
30 | ||
31 | static int llc_find_offset(int state, int ev_type); | |
32 | static void llc_conn_send_pdus(struct sock *sk); | |
33 | static int llc_conn_service(struct sock *sk, struct sk_buff *skb); | |
34 | static int llc_exec_conn_trans_actions(struct sock *sk, | |
35 | struct llc_conn_state_trans *trans, | |
36 | struct sk_buff *ev); | |
37 | static struct llc_conn_state_trans *llc_qualify_conn_ev(struct sock *sk, | |
38 | struct sk_buff *skb); | |
39 | ||
40 | /* Offset table on connection states transition diagram */ | |
41 | static int llc_offset_table[NBR_CONN_STATES][NBR_CONN_EV]; | |
42 | ||
590232a7 ACM |
43 | int sysctl_llc2_ack_timeout = LLC2_ACK_TIME * HZ; |
44 | int sysctl_llc2_p_timeout = LLC2_P_TIME * HZ; | |
45 | int sysctl_llc2_rej_timeout = LLC2_REJ_TIME * HZ; | |
46 | int sysctl_llc2_busy_timeout = LLC2_BUSY_TIME * HZ; | |
47 | ||
1da177e4 LT |
48 | /** |
49 | * llc_conn_state_process - sends event to connection state machine | |
50 | * @sk: connection | |
51 | * @skb: occurred event | |
52 | * | |
53 | * Sends an event to connection state machine. After processing event | |
54 | * (executing it's actions and changing state), upper layer will be | |
55 | * indicated or confirmed, if needed. Returns 0 for success, 1 for | |
56 | * failure. The socket lock has to be held before calling this function. | |
57 | */ | |
58 | int llc_conn_state_process(struct sock *sk, struct sk_buff *skb) | |
59 | { | |
60 | int rc; | |
61 | struct llc_sock *llc = llc_sk(sk); | |
62 | struct llc_conn_state_ev *ev = llc_conn_ev(skb); | |
63 | ||
64 | /* | |
65 | * We have to hold the skb, because llc_conn_service will kfree it in | |
66 | * the sending path and we need to look at the skb->cb, where we encode | |
67 | * llc_conn_state_ev. | |
68 | */ | |
69 | skb_get(skb); | |
70 | ev->ind_prim = ev->cfm_prim = 0; | |
71 | rc = llc_conn_service(sk, skb); /* sending event to state machine */ | |
af426d32 | 72 | if (unlikely(rc != 0)) { |
1da177e4 LT |
73 | printk(KERN_ERR "%s: llc_conn_service failed\n", __FUNCTION__); |
74 | goto out_kfree_skb; | |
75 | } | |
76 | ||
af426d32 | 77 | if (unlikely(!ev->ind_prim && !ev->cfm_prim)) { |
1da177e4 | 78 | /* indicate or confirm not required */ |
8728b834 DM |
79 | /* XXX this is not very pretty, perhaps we should store |
80 | * XXX indicate/confirm-needed state in the llc_conn_state_ev | |
81 | * XXX control block of the SKB instead? -DaveM | |
82 | */ | |
83 | if (!skb->next) | |
1da177e4 LT |
84 | goto out_kfree_skb; |
85 | goto out_skb_put; | |
86 | } | |
87 | ||
af426d32 | 88 | if (unlikely(ev->ind_prim && ev->cfm_prim)) /* Paranoia */ |
1da177e4 LT |
89 | skb_get(skb); |
90 | ||
91 | switch (ev->ind_prim) { | |
92 | case LLC_DATA_PRIM: | |
93 | llc_save_primitive(skb, LLC_DATA_PRIM); | |
94 | if (sock_queue_rcv_skb(sk, skb)) { | |
95 | /* | |
96 | * shouldn't happen | |
97 | */ | |
98 | printk(KERN_ERR "%s: sock_queue_rcv_skb failed!\n", | |
99 | __FUNCTION__); | |
100 | kfree_skb(skb); | |
101 | } | |
102 | break; | |
103 | case LLC_CONN_PRIM: { | |
104 | struct sock *parent = skb->sk; | |
105 | ||
106 | skb->sk = sk; | |
107 | skb_queue_tail(&parent->sk_receive_queue, skb); | |
108 | sk->sk_state_change(parent); | |
109 | } | |
110 | break; | |
111 | case LLC_DISC_PRIM: | |
112 | sock_hold(sk); | |
113 | if (sk->sk_type == SOCK_STREAM && | |
114 | sk->sk_state == TCP_ESTABLISHED) { | |
115 | sk->sk_shutdown = SHUTDOWN_MASK; | |
116 | sk->sk_socket->state = SS_UNCONNECTED; | |
117 | sk->sk_state = TCP_CLOSE; | |
118 | if (!sock_flag(sk, SOCK_DEAD)) { | |
119 | sk->sk_state_change(sk); | |
120 | sock_set_flag(sk, SOCK_DEAD); | |
121 | } | |
122 | } | |
123 | kfree_skb(skb); | |
124 | sock_put(sk); | |
125 | break; | |
126 | case LLC_RESET_PRIM: | |
127 | /* | |
128 | * FIXME: | |
129 | * RESET is not being notified to upper layers for now | |
130 | */ | |
131 | printk(KERN_INFO "%s: received a reset ind!\n", __FUNCTION__); | |
132 | kfree_skb(skb); | |
133 | break; | |
134 | default: | |
135 | if (ev->ind_prim) { | |
136 | printk(KERN_INFO "%s: received unknown %d prim!\n", | |
137 | __FUNCTION__, ev->ind_prim); | |
138 | kfree_skb(skb); | |
139 | } | |
140 | /* No indication */ | |
141 | break; | |
142 | } | |
143 | ||
144 | switch (ev->cfm_prim) { | |
145 | case LLC_DATA_PRIM: | |
146 | if (!llc_data_accept_state(llc->state)) | |
147 | sk->sk_write_space(sk); | |
148 | else | |
149 | rc = llc->failed_data_req = 1; | |
150 | break; | |
151 | case LLC_CONN_PRIM: | |
152 | if (sk->sk_type == SOCK_STREAM && | |
153 | sk->sk_state == TCP_SYN_SENT) { | |
154 | if (ev->status) { | |
155 | sk->sk_socket->state = SS_UNCONNECTED; | |
156 | sk->sk_state = TCP_CLOSE; | |
157 | } else { | |
158 | sk->sk_socket->state = SS_CONNECTED; | |
159 | sk->sk_state = TCP_ESTABLISHED; | |
160 | } | |
161 | sk->sk_state_change(sk); | |
162 | } | |
163 | break; | |
164 | case LLC_DISC_PRIM: | |
165 | sock_hold(sk); | |
166 | if (sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_CLOSING) { | |
167 | sk->sk_socket->state = SS_UNCONNECTED; | |
168 | sk->sk_state = TCP_CLOSE; | |
169 | sk->sk_state_change(sk); | |
170 | } | |
171 | sock_put(sk); | |
172 | break; | |
173 | case LLC_RESET_PRIM: | |
174 | /* | |
175 | * FIXME: | |
176 | * RESET is not being notified to upper layers for now | |
177 | */ | |
178 | printk(KERN_INFO "%s: received a reset conf!\n", __FUNCTION__); | |
179 | break; | |
180 | default: | |
181 | if (ev->cfm_prim) { | |
182 | printk(KERN_INFO "%s: received unknown %d prim!\n", | |
183 | __FUNCTION__, ev->cfm_prim); | |
184 | break; | |
185 | } | |
186 | goto out_skb_put; /* No confirmation */ | |
187 | } | |
188 | out_kfree_skb: | |
189 | kfree_skb(skb); | |
190 | out_skb_put: | |
191 | kfree_skb(skb); | |
192 | return rc; | |
193 | } | |
194 | ||
195 | void llc_conn_send_pdu(struct sock *sk, struct sk_buff *skb) | |
196 | { | |
197 | /* queue PDU to send to MAC layer */ | |
198 | skb_queue_tail(&sk->sk_write_queue, skb); | |
199 | llc_conn_send_pdus(sk); | |
200 | } | |
201 | ||
202 | /** | |
203 | * llc_conn_rtn_pdu - sends received data pdu to upper layer | |
204 | * @sk: Active connection | |
205 | * @skb: Received data frame | |
206 | * | |
207 | * Sends received data pdu to upper layer (by using indicate function). | |
208 | * Prepares service parameters (prim and prim_data). calling indication | |
209 | * function will be done in llc_conn_state_process. | |
210 | */ | |
211 | void llc_conn_rtn_pdu(struct sock *sk, struct sk_buff *skb) | |
212 | { | |
213 | struct llc_conn_state_ev *ev = llc_conn_ev(skb); | |
214 | ||
215 | ev->ind_prim = LLC_DATA_PRIM; | |
216 | } | |
217 | ||
218 | /** | |
219 | * llc_conn_resend_i_pdu_as_cmd - resend all all unacknowledged I PDUs | |
220 | * @sk: active connection | |
221 | * @nr: NR | |
222 | * @first_p_bit: p_bit value of first pdu | |
223 | * | |
224 | * Resend all unacknowledged I PDUs, starting with the NR; send first as | |
225 | * command PDU with P bit equal first_p_bit; if more than one send | |
226 | * subsequent as command PDUs with P bit equal zero (0). | |
227 | */ | |
228 | void llc_conn_resend_i_pdu_as_cmd(struct sock *sk, u8 nr, u8 first_p_bit) | |
229 | { | |
230 | struct sk_buff *skb; | |
231 | struct llc_pdu_sn *pdu; | |
232 | u16 nbr_unack_pdus; | |
233 | struct llc_sock *llc; | |
234 | u8 howmany_resend = 0; | |
235 | ||
236 | llc_conn_remove_acked_pdus(sk, nr, &nbr_unack_pdus); | |
237 | if (!nbr_unack_pdus) | |
238 | goto out; | |
239 | /* | |
240 | * Process unack PDUs only if unack queue is not empty; remove | |
241 | * appropriate PDUs, fix them up, and put them on mac_pdu_q. | |
242 | */ | |
243 | llc = llc_sk(sk); | |
244 | ||
245 | while ((skb = skb_dequeue(&llc->pdu_unack_q)) != NULL) { | |
246 | pdu = llc_pdu_sn_hdr(skb); | |
247 | llc_pdu_set_cmd_rsp(skb, LLC_PDU_CMD); | |
248 | llc_pdu_set_pf_bit(skb, first_p_bit); | |
249 | skb_queue_tail(&sk->sk_write_queue, skb); | |
250 | first_p_bit = 0; | |
251 | llc->vS = LLC_I_GET_NS(pdu); | |
252 | howmany_resend++; | |
253 | } | |
254 | if (howmany_resend > 0) | |
255 | llc->vS = (llc->vS + 1) % LLC_2_SEQ_NBR_MODULO; | |
256 | /* any PDUs to re-send are queued up; start sending to MAC */ | |
257 | llc_conn_send_pdus(sk); | |
258 | out:; | |
259 | } | |
260 | ||
261 | /** | |
262 | * llc_conn_resend_i_pdu_as_rsp - Resend all unacknowledged I PDUs | |
263 | * @sk: active connection. | |
264 | * @nr: NR | |
265 | * @first_f_bit: f_bit value of first pdu. | |
266 | * | |
267 | * Resend all unacknowledged I PDUs, starting with the NR; send first as | |
268 | * response PDU with F bit equal first_f_bit; if more than one send | |
269 | * subsequent as response PDUs with F bit equal zero (0). | |
270 | */ | |
271 | void llc_conn_resend_i_pdu_as_rsp(struct sock *sk, u8 nr, u8 first_f_bit) | |
272 | { | |
273 | struct sk_buff *skb; | |
274 | u16 nbr_unack_pdus; | |
275 | struct llc_sock *llc = llc_sk(sk); | |
276 | u8 howmany_resend = 0; | |
277 | ||
278 | llc_conn_remove_acked_pdus(sk, nr, &nbr_unack_pdus); | |
279 | if (!nbr_unack_pdus) | |
280 | goto out; | |
281 | /* | |
282 | * Process unack PDUs only if unack queue is not empty; remove | |
283 | * appropriate PDUs, fix them up, and put them on mac_pdu_q | |
284 | */ | |
285 | while ((skb = skb_dequeue(&llc->pdu_unack_q)) != NULL) { | |
286 | struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb); | |
287 | ||
288 | llc_pdu_set_cmd_rsp(skb, LLC_PDU_RSP); | |
289 | llc_pdu_set_pf_bit(skb, first_f_bit); | |
290 | skb_queue_tail(&sk->sk_write_queue, skb); | |
291 | first_f_bit = 0; | |
292 | llc->vS = LLC_I_GET_NS(pdu); | |
293 | howmany_resend++; | |
294 | } | |
295 | if (howmany_resend > 0) | |
296 | llc->vS = (llc->vS + 1) % LLC_2_SEQ_NBR_MODULO; | |
297 | /* any PDUs to re-send are queued up; start sending to MAC */ | |
298 | llc_conn_send_pdus(sk); | |
299 | out:; | |
300 | } | |
301 | ||
302 | /** | |
303 | * llc_conn_remove_acked_pdus - Removes acknowledged pdus from tx queue | |
304 | * @sk: active connection | |
305 | * nr: NR | |
306 | * how_many_unacked: size of pdu_unack_q after removing acked pdus | |
307 | * | |
308 | * Removes acknowledged pdus from transmit queue (pdu_unack_q). Returns | |
309 | * the number of pdus that removed from queue. | |
310 | */ | |
311 | int llc_conn_remove_acked_pdus(struct sock *sk, u8 nr, u16 *how_many_unacked) | |
312 | { | |
313 | int pdu_pos, i; | |
314 | struct sk_buff *skb; | |
315 | struct llc_pdu_sn *pdu; | |
316 | int nbr_acked = 0; | |
317 | struct llc_sock *llc = llc_sk(sk); | |
318 | int q_len = skb_queue_len(&llc->pdu_unack_q); | |
319 | ||
320 | if (!q_len) | |
321 | goto out; | |
322 | skb = skb_peek(&llc->pdu_unack_q); | |
323 | pdu = llc_pdu_sn_hdr(skb); | |
324 | ||
325 | /* finding position of last acked pdu in queue */ | |
326 | pdu_pos = ((int)LLC_2_SEQ_NBR_MODULO + (int)nr - | |
327 | (int)LLC_I_GET_NS(pdu)) % LLC_2_SEQ_NBR_MODULO; | |
328 | ||
329 | for (i = 0; i < pdu_pos && i < q_len; i++) { | |
330 | skb = skb_dequeue(&llc->pdu_unack_q); | |
331 | if (skb) | |
332 | kfree_skb(skb); | |
333 | nbr_acked++; | |
334 | } | |
335 | out: | |
336 | *how_many_unacked = skb_queue_len(&llc->pdu_unack_q); | |
337 | return nbr_acked; | |
338 | } | |
339 | ||
340 | /** | |
341 | * llc_conn_send_pdus - Sends queued PDUs | |
342 | * @sk: active connection | |
343 | * | |
344 | * Sends queued pdus to MAC layer for transmission. | |
345 | */ | |
346 | static void llc_conn_send_pdus(struct sock *sk) | |
347 | { | |
348 | struct sk_buff *skb; | |
349 | ||
350 | while ((skb = skb_dequeue(&sk->sk_write_queue)) != NULL) { | |
351 | struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb); | |
352 | ||
353 | if (LLC_PDU_TYPE_IS_I(pdu) && | |
354 | !(skb->dev->flags & IFF_LOOPBACK)) { | |
355 | struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); | |
356 | ||
357 | skb_queue_tail(&llc_sk(sk)->pdu_unack_q, skb); | |
358 | if (!skb2) | |
359 | break; | |
360 | skb = skb2; | |
361 | } | |
362 | dev_queue_xmit(skb); | |
363 | } | |
364 | } | |
365 | ||
366 | /** | |
367 | * llc_conn_service - finds transition and changes state of connection | |
368 | * @sk: connection | |
369 | * @skb: happened event | |
370 | * | |
371 | * This function finds transition that matches with happened event, then | |
372 | * executes related actions and finally changes state of connection. | |
373 | * Returns 0 for success, 1 for failure. | |
374 | */ | |
375 | static int llc_conn_service(struct sock *sk, struct sk_buff *skb) | |
376 | { | |
377 | int rc = 1; | |
378 | struct llc_sock *llc = llc_sk(sk); | |
379 | struct llc_conn_state_trans *trans; | |
380 | ||
381 | if (llc->state > NBR_CONN_STATES) | |
382 | goto out; | |
383 | rc = 0; | |
384 | trans = llc_qualify_conn_ev(sk, skb); | |
385 | if (trans) { | |
386 | rc = llc_exec_conn_trans_actions(sk, trans, skb); | |
387 | if (!rc && trans->next_state != NO_STATE_CHANGE) { | |
388 | llc->state = trans->next_state; | |
389 | if (!llc_data_accept_state(llc->state)) | |
390 | sk->sk_state_change(sk); | |
391 | } | |
392 | } | |
393 | out: | |
394 | return rc; | |
395 | } | |
396 | ||
397 | /** | |
398 | * llc_qualify_conn_ev - finds transition for event | |
399 | * @sk: connection | |
400 | * @skb: happened event | |
401 | * | |
402 | * This function finds transition that matches with happened event. | |
403 | * Returns pointer to found transition on success, %NULL otherwise. | |
404 | */ | |
405 | static struct llc_conn_state_trans *llc_qualify_conn_ev(struct sock *sk, | |
406 | struct sk_buff *skb) | |
407 | { | |
408 | struct llc_conn_state_trans **next_trans; | |
409 | llc_conn_ev_qfyr_t *next_qualifier; | |
410 | struct llc_conn_state_ev *ev = llc_conn_ev(skb); | |
411 | struct llc_sock *llc = llc_sk(sk); | |
412 | struct llc_conn_state *curr_state = | |
413 | &llc_conn_state_table[llc->state - 1]; | |
414 | ||
415 | /* search thru events for this state until | |
416 | * list exhausted or until no more | |
417 | */ | |
418 | for (next_trans = curr_state->transitions + | |
419 | llc_find_offset(llc->state - 1, ev->type); | |
420 | (*next_trans)->ev; next_trans++) { | |
421 | if (!((*next_trans)->ev)(sk, skb)) { | |
422 | /* got POSSIBLE event match; the event may require | |
423 | * qualification based on the values of a number of | |
424 | * state flags; if all qualifications are met (i.e., | |
425 | * if all qualifying functions return success, or 0, | |
426 | * then this is THE event we're looking for | |
427 | */ | |
428 | for (next_qualifier = (*next_trans)->ev_qualifiers; | |
429 | next_qualifier && *next_qualifier && | |
430 | !(*next_qualifier)(sk, skb); next_qualifier++) | |
431 | /* nothing */; | |
432 | if (!next_qualifier || !*next_qualifier) | |
433 | /* all qualifiers executed successfully; this is | |
434 | * our transition; return it so we can perform | |
435 | * the associated actions & change the state | |
436 | */ | |
437 | return *next_trans; | |
438 | } | |
439 | } | |
440 | return NULL; | |
441 | } | |
442 | ||
443 | /** | |
444 | * llc_exec_conn_trans_actions - executes related actions | |
445 | * @sk: connection | |
446 | * @trans: transition that it's actions must be performed | |
447 | * @skb: event | |
448 | * | |
449 | * Executes actions that is related to happened event. Returns 0 for | |
450 | * success, 1 to indicate failure of at least one action. | |
451 | */ | |
452 | static int llc_exec_conn_trans_actions(struct sock *sk, | |
453 | struct llc_conn_state_trans *trans, | |
454 | struct sk_buff *skb) | |
455 | { | |
456 | int rc = 0; | |
457 | llc_conn_action_t *next_action; | |
458 | ||
459 | for (next_action = trans->ev_actions; | |
460 | next_action && *next_action; next_action++) { | |
461 | int rc2 = (*next_action)(sk, skb); | |
462 | ||
463 | if (rc2 == 2) { | |
464 | rc = rc2; | |
465 | break; | |
466 | } else if (rc2) | |
467 | rc = 1; | |
468 | } | |
469 | return rc; | |
470 | } | |
471 | ||
472 | /** | |
473 | * llc_lookup_established - Finds connection for the remote/local sap/mac | |
474 | * @sap: SAP | |
475 | * @daddr: address of remote LLC (MAC + SAP) | |
476 | * @laddr: address of local LLC (MAC + SAP) | |
477 | * | |
478 | * Search connection list of the SAP and finds connection using the remote | |
479 | * mac, remote sap, local mac, and local sap. Returns pointer for | |
480 | * connection found, %NULL otherwise. | |
481 | */ | |
482 | struct sock *llc_lookup_established(struct llc_sap *sap, struct llc_addr *daddr, | |
483 | struct llc_addr *laddr) | |
484 | { | |
485 | struct sock *rc; | |
486 | struct hlist_node *node; | |
487 | ||
488 | read_lock_bh(&sap->sk_list.lock); | |
489 | sk_for_each(rc, node, &sap->sk_list.list) { | |
490 | struct llc_sock *llc = llc_sk(rc); | |
491 | ||
492 | if (llc->laddr.lsap == laddr->lsap && | |
493 | llc->daddr.lsap == daddr->lsap && | |
494 | llc_mac_match(llc->laddr.mac, laddr->mac) && | |
495 | llc_mac_match(llc->daddr.mac, daddr->mac)) { | |
496 | sock_hold(rc); | |
497 | goto found; | |
498 | } | |
499 | } | |
500 | rc = NULL; | |
501 | found: | |
502 | read_unlock_bh(&sap->sk_list.lock); | |
503 | return rc; | |
504 | } | |
505 | ||
506 | /** | |
507 | * llc_lookup_listener - Finds listener for local MAC + SAP | |
508 | * @sap: SAP | |
509 | * @laddr: address of local LLC (MAC + SAP) | |
510 | * | |
511 | * Search connection list of the SAP and finds connection listening on | |
512 | * local mac, and local sap. Returns pointer for parent socket found, | |
513 | * %NULL otherwise. | |
514 | */ | |
515 | static struct sock *llc_lookup_listener(struct llc_sap *sap, | |
516 | struct llc_addr *laddr) | |
517 | { | |
518 | struct sock *rc; | |
519 | struct hlist_node *node; | |
520 | ||
521 | read_lock_bh(&sap->sk_list.lock); | |
522 | sk_for_each(rc, node, &sap->sk_list.list) { | |
523 | struct llc_sock *llc = llc_sk(rc); | |
524 | ||
525 | if (rc->sk_type == SOCK_STREAM && rc->sk_state == TCP_LISTEN && | |
526 | llc->laddr.lsap == laddr->lsap && | |
527 | (llc_mac_match(llc->laddr.mac, laddr->mac) || | |
528 | llc_mac_null(llc->laddr.mac))) { | |
529 | sock_hold(rc); | |
530 | goto found; | |
531 | } | |
532 | } | |
533 | rc = NULL; | |
534 | found: | |
535 | read_unlock_bh(&sap->sk_list.lock); | |
536 | return rc; | |
537 | } | |
538 | ||
539 | /** | |
540 | * llc_data_accept_state - designates if in this state data can be sent. | |
541 | * @state: state of connection. | |
542 | * | |
543 | * Returns 0 if data can be sent, 1 otherwise. | |
544 | */ | |
545 | u8 llc_data_accept_state(u8 state) | |
546 | { | |
547 | return state != LLC_CONN_STATE_NORMAL && state != LLC_CONN_STATE_BUSY && | |
548 | state != LLC_CONN_STATE_REJ; | |
549 | } | |
550 | ||
551 | /** | |
0eb80172 | 552 | * llc_find_next_offset - finds offset for next category of transitions |
1da177e4 LT |
553 | * @state: state table. |
554 | * @offset: start offset. | |
555 | * | |
556 | * Finds offset of next category of transitions in transition table. | |
557 | * Returns the start index of next category. | |
558 | */ | |
0eb80172 | 559 | static u16 __init llc_find_next_offset(struct llc_conn_state *state, u16 offset) |
1da177e4 LT |
560 | { |
561 | u16 cnt = 0; | |
562 | struct llc_conn_state_trans **next_trans; | |
563 | ||
564 | for (next_trans = state->transitions + offset; | |
565 | (*next_trans)->ev; next_trans++) | |
566 | ++cnt; | |
567 | return cnt; | |
568 | } | |
569 | ||
570 | /** | |
571 | * llc_build_offset_table - builds offset table of connection | |
572 | * | |
573 | * Fills offset table of connection state transition table | |
574 | * (llc_offset_table). | |
575 | */ | |
576 | void __init llc_build_offset_table(void) | |
577 | { | |
578 | struct llc_conn_state *curr_state; | |
579 | int state, ev_type, next_offset; | |
580 | ||
581 | for (state = 0; state < NBR_CONN_STATES; state++) { | |
582 | curr_state = &llc_conn_state_table[state]; | |
583 | next_offset = 0; | |
584 | for (ev_type = 0; ev_type < NBR_CONN_EV; ev_type++) { | |
585 | llc_offset_table[state][ev_type] = next_offset; | |
0eb80172 ACM |
586 | next_offset += llc_find_next_offset(curr_state, |
587 | next_offset) + 1; | |
1da177e4 LT |
588 | } |
589 | } | |
590 | } | |
591 | ||
592 | /** | |
593 | * llc_find_offset - finds start offset of category of transitions | |
594 | * @state: state of connection | |
595 | * @ev_type: type of happened event | |
596 | * | |
597 | * Finds start offset of desired category of transitions. Returns the | |
598 | * desired start offset. | |
599 | */ | |
600 | static int llc_find_offset(int state, int ev_type) | |
601 | { | |
602 | int rc = 0; | |
603 | /* at this stage, llc_offset_table[..][2] is not important. it is for | |
604 | * init_pf_cycle and I don't know what is it. | |
605 | */ | |
606 | switch (ev_type) { | |
607 | case LLC_CONN_EV_TYPE_PRIM: | |
608 | rc = llc_offset_table[state][0]; break; | |
609 | case LLC_CONN_EV_TYPE_PDU: | |
610 | rc = llc_offset_table[state][4]; break; | |
611 | case LLC_CONN_EV_TYPE_SIMPLE: | |
612 | rc = llc_offset_table[state][1]; break; | |
613 | case LLC_CONN_EV_TYPE_P_TMR: | |
614 | case LLC_CONN_EV_TYPE_ACK_TMR: | |
615 | case LLC_CONN_EV_TYPE_REJ_TMR: | |
616 | case LLC_CONN_EV_TYPE_BUSY_TMR: | |
617 | rc = llc_offset_table[state][3]; break; | |
618 | } | |
619 | return rc; | |
620 | } | |
621 | ||
622 | /** | |
623 | * llc_sap_add_socket - adds a socket to a SAP | |
624 | * @sap: SAP | |
625 | * @sk: socket | |
626 | * | |
627 | * This function adds a socket to sk_list of a SAP. | |
628 | */ | |
629 | void llc_sap_add_socket(struct llc_sap *sap, struct sock *sk) | |
630 | { | |
631 | write_lock_bh(&sap->sk_list.lock); | |
632 | llc_sk(sk)->sap = sap; | |
633 | sk_add_node(sk, &sap->sk_list.list); | |
634 | write_unlock_bh(&sap->sk_list.lock); | |
635 | } | |
636 | ||
637 | /** | |
638 | * llc_sap_remove_socket - removes a socket from SAP | |
639 | * @sap: SAP | |
640 | * @sk: socket | |
641 | * | |
642 | * This function removes a connection from sk_list.list of a SAP if | |
643 | * the connection was in this list. | |
644 | */ | |
645 | void llc_sap_remove_socket(struct llc_sap *sap, struct sock *sk) | |
646 | { | |
647 | write_lock_bh(&sap->sk_list.lock); | |
648 | sk_del_node_init(sk); | |
649 | write_unlock_bh(&sap->sk_list.lock); | |
650 | } | |
651 | ||
652 | /** | |
653 | * llc_conn_rcv - sends received pdus to the connection state machine | |
654 | * @sk: current connection structure. | |
655 | * @skb: received frame. | |
656 | * | |
657 | * Sends received pdus to the connection state machine. | |
658 | */ | |
659 | static int llc_conn_rcv(struct sock* sk, struct sk_buff *skb) | |
660 | { | |
661 | struct llc_conn_state_ev *ev = llc_conn_ev(skb); | |
662 | struct llc_sock *llc = llc_sk(sk); | |
663 | ||
664 | if (!llc->dev) | |
665 | llc->dev = skb->dev; | |
666 | ev->type = LLC_CONN_EV_TYPE_PDU; | |
667 | ev->reason = 0; | |
668 | return llc_conn_state_process(sk, skb); | |
669 | } | |
670 | ||
671 | void llc_conn_handler(struct llc_sap *sap, struct sk_buff *skb) | |
672 | { | |
673 | struct llc_addr saddr, daddr; | |
674 | struct sock *sk; | |
675 | ||
676 | llc_pdu_decode_sa(skb, saddr.mac); | |
677 | llc_pdu_decode_ssap(skb, &saddr.lsap); | |
678 | llc_pdu_decode_da(skb, daddr.mac); | |
679 | llc_pdu_decode_dsap(skb, &daddr.lsap); | |
680 | ||
681 | sk = llc_lookup_established(sap, &saddr, &daddr); | |
682 | if (!sk) { | |
683 | /* | |
684 | * Didn't find an active connection; verify if there | |
685 | * is a listening socket for this llc addr | |
686 | */ | |
687 | struct llc_sock *llc; | |
688 | struct sock *parent = llc_lookup_listener(sap, &daddr); | |
689 | ||
690 | if (!parent) { | |
691 | dprintk("llc_lookup_listener failed!\n"); | |
692 | goto drop; | |
693 | } | |
694 | ||
695 | sk = llc_sk_alloc(parent->sk_family, GFP_ATOMIC, parent->sk_prot); | |
696 | if (!sk) { | |
697 | sock_put(parent); | |
698 | goto drop; | |
699 | } | |
700 | llc = llc_sk(sk); | |
701 | memcpy(&llc->laddr, &daddr, sizeof(llc->laddr)); | |
702 | memcpy(&llc->daddr, &saddr, sizeof(llc->daddr)); | |
703 | llc_sap_add_socket(sap, sk); | |
704 | sock_hold(sk); | |
705 | sock_put(parent); | |
706 | skb->sk = parent; | |
707 | } else | |
708 | skb->sk = sk; | |
709 | bh_lock_sock(sk); | |
710 | if (!sock_owned_by_user(sk)) | |
711 | llc_conn_rcv(sk, skb); | |
712 | else { | |
713 | dprintk("%s: adding to backlog...\n", __FUNCTION__); | |
714 | llc_set_backlog_type(skb, LLC_PACKET); | |
715 | sk_add_backlog(sk, skb); | |
716 | } | |
717 | bh_unlock_sock(sk); | |
718 | sock_put(sk); | |
719 | return; | |
720 | drop: | |
721 | kfree_skb(skb); | |
722 | } | |
723 | ||
724 | #undef LLC_REFCNT_DEBUG | |
725 | #ifdef LLC_REFCNT_DEBUG | |
726 | static atomic_t llc_sock_nr; | |
727 | #endif | |
728 | ||
729 | /** | |
730 | * llc_release_sockets - releases all sockets in a sap | |
731 | * @sap: sap to release its sockets | |
732 | * | |
733 | * Releases all connections of a sap. Returns 0 if all actions complete | |
734 | * successfully, nonzero otherwise | |
735 | */ | |
736 | int llc_release_sockets(struct llc_sap *sap) | |
737 | { | |
738 | int rc = 0; | |
739 | struct sock *sk; | |
740 | struct hlist_node *node; | |
741 | ||
742 | write_lock_bh(&sap->sk_list.lock); | |
743 | ||
744 | sk_for_each(sk, node, &sap->sk_list.list) { | |
745 | llc_sk(sk)->state = LLC_CONN_STATE_TEMP; | |
746 | ||
747 | if (llc_send_disc(sk)) | |
748 | rc = 1; | |
749 | } | |
750 | ||
751 | write_unlock_bh(&sap->sk_list.lock); | |
752 | return rc; | |
753 | } | |
754 | ||
755 | /** | |
756 | * llc_backlog_rcv - Processes rx frames and expired timers. | |
757 | * @sk: LLC sock (p8022 connection) | |
758 | * @skb: queued rx frame or event | |
759 | * | |
760 | * This function processes frames that has received and timers that has | |
761 | * expired during sending an I pdu (refer to data_req_handler). frames | |
762 | * queue by llc_rcv function (llc_mac.c) and timers queue by timer | |
763 | * callback functions(llc_c_ac.c). | |
764 | */ | |
765 | static int llc_backlog_rcv(struct sock *sk, struct sk_buff *skb) | |
766 | { | |
767 | int rc = 0; | |
768 | struct llc_sock *llc = llc_sk(sk); | |
769 | ||
af426d32 ACM |
770 | if (likely(llc_backlog_type(skb) == LLC_PACKET)) { |
771 | if (likely(llc->state > 1)) /* not closed */ | |
1da177e4 LT |
772 | rc = llc_conn_rcv(sk, skb); |
773 | else | |
774 | goto out_kfree_skb; | |
775 | } else if (llc_backlog_type(skb) == LLC_EVENT) { | |
776 | /* timer expiration event */ | |
af426d32 | 777 | if (likely(llc->state > 1)) /* not closed */ |
1da177e4 LT |
778 | rc = llc_conn_state_process(sk, skb); |
779 | else | |
780 | goto out_kfree_skb; | |
781 | } else { | |
782 | printk(KERN_ERR "%s: invalid skb in backlog\n", __FUNCTION__); | |
783 | goto out_kfree_skb; | |
784 | } | |
785 | out: | |
786 | return rc; | |
787 | out_kfree_skb: | |
788 | kfree_skb(skb); | |
789 | goto out; | |
790 | } | |
791 | ||
792 | /** | |
793 | * llc_sk_init - Initializes a socket with default llc values. | |
794 | * @sk: socket to initialize. | |
795 | * | |
796 | * Initializes a socket with default llc values. | |
797 | */ | |
798 | static void llc_sk_init(struct sock* sk) | |
799 | { | |
800 | struct llc_sock *llc = llc_sk(sk); | |
801 | ||
802 | llc->state = LLC_CONN_STATE_ADM; | |
803 | llc->inc_cntr = llc->dec_cntr = 2; | |
804 | llc->dec_step = llc->connect_step = 1; | |
805 | ||
806 | init_timer(&llc->ack_timer.timer); | |
590232a7 | 807 | llc->ack_timer.expire = sysctl_llc2_ack_timeout; |
1da177e4 LT |
808 | llc->ack_timer.timer.data = (unsigned long)sk; |
809 | llc->ack_timer.timer.function = llc_conn_ack_tmr_cb; | |
810 | ||
811 | init_timer(&llc->pf_cycle_timer.timer); | |
590232a7 | 812 | llc->pf_cycle_timer.expire = sysctl_llc2_p_timeout; |
1da177e4 LT |
813 | llc->pf_cycle_timer.timer.data = (unsigned long)sk; |
814 | llc->pf_cycle_timer.timer.function = llc_conn_pf_cycle_tmr_cb; | |
815 | ||
816 | init_timer(&llc->rej_sent_timer.timer); | |
590232a7 | 817 | llc->rej_sent_timer.expire = sysctl_llc2_rej_timeout; |
1da177e4 LT |
818 | llc->rej_sent_timer.timer.data = (unsigned long)sk; |
819 | llc->rej_sent_timer.timer.function = llc_conn_rej_tmr_cb; | |
820 | ||
821 | init_timer(&llc->busy_state_timer.timer); | |
590232a7 | 822 | llc->busy_state_timer.expire = sysctl_llc2_busy_timeout; |
1da177e4 LT |
823 | llc->busy_state_timer.timer.data = (unsigned long)sk; |
824 | llc->busy_state_timer.timer.function = llc_conn_busy_tmr_cb; | |
825 | ||
826 | llc->n2 = 2; /* max retransmit */ | |
827 | llc->k = 2; /* tx win size, will adjust dynam */ | |
828 | llc->rw = 128; /* rx win size (opt and equal to | |
829 | * tx_win of remote LLC) */ | |
830 | skb_queue_head_init(&llc->pdu_unack_q); | |
831 | sk->sk_backlog_rcv = llc_backlog_rcv; | |
832 | } | |
833 | ||
834 | /** | |
835 | * llc_sk_alloc - Allocates LLC sock | |
836 | * @family: upper layer protocol family | |
837 | * @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc) | |
838 | * | |
839 | * Allocates a LLC sock and initializes it. Returns the new LLC sock | |
840 | * or %NULL if there's no memory available for one | |
841 | */ | |
842 | struct sock *llc_sk_alloc(int family, int priority, struct proto *prot) | |
843 | { | |
844 | struct sock *sk = sk_alloc(family, priority, prot, 1); | |
845 | ||
846 | if (!sk) | |
847 | goto out; | |
848 | llc_sk_init(sk); | |
849 | sock_init_data(NULL, sk); | |
850 | #ifdef LLC_REFCNT_DEBUG | |
851 | atomic_inc(&llc_sock_nr); | |
852 | printk(KERN_DEBUG "LLC socket %p created in %s, now we have %d alive\n", sk, | |
853 | __FUNCTION__, atomic_read(&llc_sock_nr)); | |
854 | #endif | |
855 | out: | |
856 | return sk; | |
857 | } | |
858 | ||
859 | /** | |
860 | * llc_sk_free - Frees a LLC socket | |
861 | * @sk - socket to free | |
862 | * | |
863 | * Frees a LLC socket | |
864 | */ | |
865 | void llc_sk_free(struct sock *sk) | |
866 | { | |
867 | struct llc_sock *llc = llc_sk(sk); | |
868 | ||
869 | llc->state = LLC_CONN_OUT_OF_SVC; | |
870 | /* Stop all (possibly) running timers */ | |
871 | llc_conn_ac_stop_all_timers(sk, NULL); | |
872 | #ifdef DEBUG_LLC_CONN_ALLOC | |
873 | printk(KERN_INFO "%s: unackq=%d, txq=%d\n", __FUNCTION__, | |
874 | skb_queue_len(&llc->pdu_unack_q), | |
875 | skb_queue_len(&sk->sk_write_queue)); | |
876 | #endif | |
877 | skb_queue_purge(&sk->sk_receive_queue); | |
878 | skb_queue_purge(&sk->sk_write_queue); | |
879 | skb_queue_purge(&llc->pdu_unack_q); | |
880 | #ifdef LLC_REFCNT_DEBUG | |
881 | if (atomic_read(&sk->sk_refcnt) != 1) { | |
882 | printk(KERN_DEBUG "Destruction of LLC sock %p delayed in %s, cnt=%d\n", | |
883 | sk, __FUNCTION__, atomic_read(&sk->sk_refcnt)); | |
884 | printk(KERN_DEBUG "%d LLC sockets are still alive\n", | |
885 | atomic_read(&llc_sock_nr)); | |
886 | } else { | |
887 | atomic_dec(&llc_sock_nr); | |
888 | printk(KERN_DEBUG "LLC socket %p released in %s, %d are still alive\n", sk, | |
889 | __FUNCTION__, atomic_read(&llc_sock_nr)); | |
890 | } | |
891 | #endif | |
892 | sock_put(sk); | |
893 | } | |
894 | ||
895 | /** | |
896 | * llc_sk_reset - resets a connection | |
897 | * @sk: LLC socket to reset | |
898 | * | |
899 | * Resets a connection to the out of service state. Stops its timers | |
900 | * and frees any frames in the queues of the connection. | |
901 | */ | |
902 | void llc_sk_reset(struct sock *sk) | |
903 | { | |
904 | struct llc_sock *llc = llc_sk(sk); | |
905 | ||
906 | llc_conn_ac_stop_all_timers(sk, NULL); | |
907 | skb_queue_purge(&sk->sk_write_queue); | |
908 | skb_queue_purge(&llc->pdu_unack_q); | |
909 | llc->remote_busy_flag = 0; | |
910 | llc->cause_flag = 0; | |
911 | llc->retry_count = 0; | |
912 | llc_conn_set_p_flag(sk, 0); | |
913 | llc->f_flag = 0; | |
914 | llc->s_flag = 0; | |
915 | llc->ack_pf = 0; | |
916 | llc->first_pdu_Ns = 0; | |
917 | llc->ack_must_be_send = 0; | |
918 | llc->dec_step = 1; | |
919 | llc->inc_cntr = 2; | |
920 | llc->dec_cntr = 2; | |
921 | llc->X = 0; | |
922 | llc->failed_data_req = 0 ; | |
923 | llc->last_nr = 0; | |
924 | } |