ia64/linux-2.6.18-xen.hg

view net/llc/llc_conn.c @ 673:3161879fdf22

[IA64] xencomm: support XENMEM_add_to_physmap and XENMEM_remove_from_phsymap

support XENMEM_add_to_physmap and XENMEM_remove_from_phsymap.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
author Isaku Yamahata <yamahata@valinux.co.jp>
date Tue Sep 16 21:26:15 2008 +0900 (2008-09-16)
parents 831230e53067
children
line source
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 */
15 #include <linux/init.h>
16 #include <net/llc_sap.h>
17 #include <net/llc_conn.h>
18 #include <net/sock.h>
19 #include <net/tcp_states.h>
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>
25 #if 0
26 #define dprintk(args...) printk(KERN_DEBUG args)
27 #else
28 #define dprintk(args...)
29 #endif
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);
40 /* Offset table on connection states transition diagram */
41 static int llc_offset_table[NBR_CONN_STATES][NBR_CONN_EV];
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;
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(skb->sk);
62 struct llc_conn_state_ev *ev = llc_conn_ev(skb);
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 /*
72 * Send event to state machine
73 */
74 rc = llc_conn_service(skb->sk, skb);
75 if (unlikely(rc != 0)) {
76 printk(KERN_ERR "%s: llc_conn_service failed\n", __FUNCTION__);
77 goto out_kfree_skb;
78 }
80 if (unlikely(!ev->ind_prim && !ev->cfm_prim)) {
81 /* indicate or confirm not required */
82 /* XXX this is not very pretty, perhaps we should store
83 * XXX indicate/confirm-needed state in the llc_conn_state_ev
84 * XXX control block of the SKB instead? -DaveM
85 */
86 if (!skb->next)
87 goto out_kfree_skb;
88 goto out_skb_put;
89 }
91 if (unlikely(ev->ind_prim && ev->cfm_prim)) /* Paranoia */
92 skb_get(skb);
94 switch (ev->ind_prim) {
95 case LLC_DATA_PRIM:
96 llc_save_primitive(sk, skb, LLC_DATA_PRIM);
97 if (unlikely(sock_queue_rcv_skb(sk, skb))) {
98 /*
99 * shouldn't happen
100 */
101 printk(KERN_ERR "%s: sock_queue_rcv_skb failed!\n",
102 __FUNCTION__);
103 kfree_skb(skb);
104 }
105 break;
106 case LLC_CONN_PRIM:
107 /*
108 * Can't be sock_queue_rcv_skb, because we have to leave the
109 * skb->sk pointing to the newly created struct sock in
110 * llc_conn_handler. -acme
111 */
112 skb_queue_tail(&sk->sk_receive_queue, skb);
113 sk->sk_state_change(sk);
114 break;
115 case LLC_DISC_PRIM:
116 sock_hold(sk);
117 if (sk->sk_type == SOCK_STREAM &&
118 sk->sk_state == TCP_ESTABLISHED) {
119 sk->sk_shutdown = SHUTDOWN_MASK;
120 sk->sk_socket->state = SS_UNCONNECTED;
121 sk->sk_state = TCP_CLOSE;
122 if (!sock_flag(sk, SOCK_DEAD)) {
123 sock_set_flag(sk, SOCK_DEAD);
124 sk->sk_state_change(sk);
125 }
126 }
127 kfree_skb(skb);
128 sock_put(sk);
129 break;
130 case LLC_RESET_PRIM:
131 /*
132 * FIXME:
133 * RESET is not being notified to upper layers for now
134 */
135 printk(KERN_INFO "%s: received a reset ind!\n", __FUNCTION__);
136 kfree_skb(skb);
137 break;
138 default:
139 if (ev->ind_prim) {
140 printk(KERN_INFO "%s: received unknown %d prim!\n",
141 __FUNCTION__, ev->ind_prim);
142 kfree_skb(skb);
143 }
144 /* No indication */
145 break;
146 }
148 switch (ev->cfm_prim) {
149 case LLC_DATA_PRIM:
150 if (!llc_data_accept_state(llc->state))
151 sk->sk_write_space(sk);
152 else
153 rc = llc->failed_data_req = 1;
154 break;
155 case LLC_CONN_PRIM:
156 if (sk->sk_type == SOCK_STREAM &&
157 sk->sk_state == TCP_SYN_SENT) {
158 if (ev->status) {
159 sk->sk_socket->state = SS_UNCONNECTED;
160 sk->sk_state = TCP_CLOSE;
161 } else {
162 sk->sk_socket->state = SS_CONNECTED;
163 sk->sk_state = TCP_ESTABLISHED;
164 }
165 sk->sk_state_change(sk);
166 }
167 break;
168 case LLC_DISC_PRIM:
169 sock_hold(sk);
170 if (sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_CLOSING) {
171 sk->sk_socket->state = SS_UNCONNECTED;
172 sk->sk_state = TCP_CLOSE;
173 sk->sk_state_change(sk);
174 }
175 sock_put(sk);
176 break;
177 case LLC_RESET_PRIM:
178 /*
179 * FIXME:
180 * RESET is not being notified to upper layers for now
181 */
182 printk(KERN_INFO "%s: received a reset conf!\n", __FUNCTION__);
183 break;
184 default:
185 if (ev->cfm_prim) {
186 printk(KERN_INFO "%s: received unknown %d prim!\n",
187 __FUNCTION__, ev->cfm_prim);
188 break;
189 }
190 goto out_skb_put; /* No confirmation */
191 }
192 out_kfree_skb:
193 kfree_skb(skb);
194 out_skb_put:
195 kfree_skb(skb);
196 return rc;
197 }
199 void llc_conn_send_pdu(struct sock *sk, struct sk_buff *skb)
200 {
201 /* queue PDU to send to MAC layer */
202 skb_queue_tail(&sk->sk_write_queue, skb);
203 llc_conn_send_pdus(sk);
204 }
206 /**
207 * llc_conn_rtn_pdu - sends received data pdu to upper layer
208 * @sk: Active connection
209 * @skb: Received data frame
210 *
211 * Sends received data pdu to upper layer (by using indicate function).
212 * Prepares service parameters (prim and prim_data). calling indication
213 * function will be done in llc_conn_state_process.
214 */
215 void llc_conn_rtn_pdu(struct sock *sk, struct sk_buff *skb)
216 {
217 struct llc_conn_state_ev *ev = llc_conn_ev(skb);
219 ev->ind_prim = LLC_DATA_PRIM;
220 }
222 /**
223 * llc_conn_resend_i_pdu_as_cmd - resend all all unacknowledged I PDUs
224 * @sk: active connection
225 * @nr: NR
226 * @first_p_bit: p_bit value of first pdu
227 *
228 * Resend all unacknowledged I PDUs, starting with the NR; send first as
229 * command PDU with P bit equal first_p_bit; if more than one send
230 * subsequent as command PDUs with P bit equal zero (0).
231 */
232 void llc_conn_resend_i_pdu_as_cmd(struct sock *sk, u8 nr, u8 first_p_bit)
233 {
234 struct sk_buff *skb;
235 struct llc_pdu_sn *pdu;
236 u16 nbr_unack_pdus;
237 struct llc_sock *llc;
238 u8 howmany_resend = 0;
240 llc_conn_remove_acked_pdus(sk, nr, &nbr_unack_pdus);
241 if (!nbr_unack_pdus)
242 goto out;
243 /*
244 * Process unack PDUs only if unack queue is not empty; remove
245 * appropriate PDUs, fix them up, and put them on mac_pdu_q.
246 */
247 llc = llc_sk(sk);
249 while ((skb = skb_dequeue(&llc->pdu_unack_q)) != NULL) {
250 pdu = llc_pdu_sn_hdr(skb);
251 llc_pdu_set_cmd_rsp(skb, LLC_PDU_CMD);
252 llc_pdu_set_pf_bit(skb, first_p_bit);
253 skb_queue_tail(&sk->sk_write_queue, skb);
254 first_p_bit = 0;
255 llc->vS = LLC_I_GET_NS(pdu);
256 howmany_resend++;
257 }
258 if (howmany_resend > 0)
259 llc->vS = (llc->vS + 1) % LLC_2_SEQ_NBR_MODULO;
260 /* any PDUs to re-send are queued up; start sending to MAC */
261 llc_conn_send_pdus(sk);
262 out:;
263 }
265 /**
266 * llc_conn_resend_i_pdu_as_rsp - Resend all unacknowledged I PDUs
267 * @sk: active connection.
268 * @nr: NR
269 * @first_f_bit: f_bit value of first pdu.
270 *
271 * Resend all unacknowledged I PDUs, starting with the NR; send first as
272 * response PDU with F bit equal first_f_bit; if more than one send
273 * subsequent as response PDUs with F bit equal zero (0).
274 */
275 void llc_conn_resend_i_pdu_as_rsp(struct sock *sk, u8 nr, u8 first_f_bit)
276 {
277 struct sk_buff *skb;
278 u16 nbr_unack_pdus;
279 struct llc_sock *llc = llc_sk(sk);
280 u8 howmany_resend = 0;
282 llc_conn_remove_acked_pdus(sk, nr, &nbr_unack_pdus);
283 if (!nbr_unack_pdus)
284 goto out;
285 /*
286 * Process unack PDUs only if unack queue is not empty; remove
287 * appropriate PDUs, fix them up, and put them on mac_pdu_q
288 */
289 while ((skb = skb_dequeue(&llc->pdu_unack_q)) != NULL) {
290 struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
292 llc_pdu_set_cmd_rsp(skb, LLC_PDU_RSP);
293 llc_pdu_set_pf_bit(skb, first_f_bit);
294 skb_queue_tail(&sk->sk_write_queue, skb);
295 first_f_bit = 0;
296 llc->vS = LLC_I_GET_NS(pdu);
297 howmany_resend++;
298 }
299 if (howmany_resend > 0)
300 llc->vS = (llc->vS + 1) % LLC_2_SEQ_NBR_MODULO;
301 /* any PDUs to re-send are queued up; start sending to MAC */
302 llc_conn_send_pdus(sk);
303 out:;
304 }
306 /**
307 * llc_conn_remove_acked_pdus - Removes acknowledged pdus from tx queue
308 * @sk: active connection
309 * nr: NR
310 * how_many_unacked: size of pdu_unack_q after removing acked pdus
311 *
312 * Removes acknowledged pdus from transmit queue (pdu_unack_q). Returns
313 * the number of pdus that removed from queue.
314 */
315 int llc_conn_remove_acked_pdus(struct sock *sk, u8 nr, u16 *how_many_unacked)
316 {
317 int pdu_pos, i;
318 struct sk_buff *skb;
319 struct llc_pdu_sn *pdu;
320 int nbr_acked = 0;
321 struct llc_sock *llc = llc_sk(sk);
322 int q_len = skb_queue_len(&llc->pdu_unack_q);
324 if (!q_len)
325 goto out;
326 skb = skb_peek(&llc->pdu_unack_q);
327 pdu = llc_pdu_sn_hdr(skb);
329 /* finding position of last acked pdu in queue */
330 pdu_pos = ((int)LLC_2_SEQ_NBR_MODULO + (int)nr -
331 (int)LLC_I_GET_NS(pdu)) % LLC_2_SEQ_NBR_MODULO;
333 for (i = 0; i < pdu_pos && i < q_len; i++) {
334 skb = skb_dequeue(&llc->pdu_unack_q);
335 if (skb)
336 kfree_skb(skb);
337 nbr_acked++;
338 }
339 out:
340 *how_many_unacked = skb_queue_len(&llc->pdu_unack_q);
341 return nbr_acked;
342 }
344 /**
345 * llc_conn_send_pdus - Sends queued PDUs
346 * @sk: active connection
347 *
348 * Sends queued pdus to MAC layer for transmission.
349 */
350 static void llc_conn_send_pdus(struct sock *sk)
351 {
352 struct sk_buff *skb;
354 while ((skb = skb_dequeue(&sk->sk_write_queue)) != NULL) {
355 struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
357 if (LLC_PDU_TYPE_IS_I(pdu) &&
358 !(skb->dev->flags & IFF_LOOPBACK)) {
359 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
361 skb_queue_tail(&llc_sk(sk)->pdu_unack_q, skb);
362 if (!skb2)
363 break;
364 skb = skb2;
365 }
366 dev_queue_xmit(skb);
367 }
368 }
370 /**
371 * llc_conn_service - finds transition and changes state of connection
372 * @sk: connection
373 * @skb: happened event
374 *
375 * This function finds transition that matches with happened event, then
376 * executes related actions and finally changes state of connection.
377 * Returns 0 for success, 1 for failure.
378 */
379 static int llc_conn_service(struct sock *sk, struct sk_buff *skb)
380 {
381 int rc = 1;
382 struct llc_sock *llc = llc_sk(sk);
383 struct llc_conn_state_trans *trans;
385 if (llc->state > NBR_CONN_STATES)
386 goto out;
387 rc = 0;
388 trans = llc_qualify_conn_ev(sk, skb);
389 if (trans) {
390 rc = llc_exec_conn_trans_actions(sk, trans, skb);
391 if (!rc && trans->next_state != NO_STATE_CHANGE) {
392 llc->state = trans->next_state;
393 if (!llc_data_accept_state(llc->state))
394 sk->sk_state_change(sk);
395 }
396 }
397 out:
398 return rc;
399 }
401 /**
402 * llc_qualify_conn_ev - finds transition for event
403 * @sk: connection
404 * @skb: happened event
405 *
406 * This function finds transition that matches with happened event.
407 * Returns pointer to found transition on success, %NULL otherwise.
408 */
409 static struct llc_conn_state_trans *llc_qualify_conn_ev(struct sock *sk,
410 struct sk_buff *skb)
411 {
412 struct llc_conn_state_trans **next_trans;
413 llc_conn_ev_qfyr_t *next_qualifier;
414 struct llc_conn_state_ev *ev = llc_conn_ev(skb);
415 struct llc_sock *llc = llc_sk(sk);
416 struct llc_conn_state *curr_state =
417 &llc_conn_state_table[llc->state - 1];
419 /* search thru events for this state until
420 * list exhausted or until no more
421 */
422 for (next_trans = curr_state->transitions +
423 llc_find_offset(llc->state - 1, ev->type);
424 (*next_trans)->ev; next_trans++) {
425 if (!((*next_trans)->ev)(sk, skb)) {
426 /* got POSSIBLE event match; the event may require
427 * qualification based on the values of a number of
428 * state flags; if all qualifications are met (i.e.,
429 * if all qualifying functions return success, or 0,
430 * then this is THE event we're looking for
431 */
432 for (next_qualifier = (*next_trans)->ev_qualifiers;
433 next_qualifier && *next_qualifier &&
434 !(*next_qualifier)(sk, skb); next_qualifier++)
435 /* nothing */;
436 if (!next_qualifier || !*next_qualifier)
437 /* all qualifiers executed successfully; this is
438 * our transition; return it so we can perform
439 * the associated actions & change the state
440 */
441 return *next_trans;
442 }
443 }
444 return NULL;
445 }
447 /**
448 * llc_exec_conn_trans_actions - executes related actions
449 * @sk: connection
450 * @trans: transition that it's actions must be performed
451 * @skb: event
452 *
453 * Executes actions that is related to happened event. Returns 0 for
454 * success, 1 to indicate failure of at least one action.
455 */
456 static int llc_exec_conn_trans_actions(struct sock *sk,
457 struct llc_conn_state_trans *trans,
458 struct sk_buff *skb)
459 {
460 int rc = 0;
461 llc_conn_action_t *next_action;
463 for (next_action = trans->ev_actions;
464 next_action && *next_action; next_action++) {
465 int rc2 = (*next_action)(sk, skb);
467 if (rc2 == 2) {
468 rc = rc2;
469 break;
470 } else if (rc2)
471 rc = 1;
472 }
473 return rc;
474 }
476 /**
477 * __llc_lookup_established - Finds connection for the remote/local sap/mac
478 * @sap: SAP
479 * @daddr: address of remote LLC (MAC + SAP)
480 * @laddr: address of local LLC (MAC + SAP)
481 *
482 * Search connection list of the SAP and finds connection using the remote
483 * mac, remote sap, local mac, and local sap. Returns pointer for
484 * connection found, %NULL otherwise.
485 * Caller has to make sure local_bh is disabled.
486 */
487 static struct sock *__llc_lookup_established(struct llc_sap *sap,
488 struct llc_addr *daddr,
489 struct llc_addr *laddr)
490 {
491 struct sock *rc;
492 struct hlist_node *node;
494 read_lock(&sap->sk_list.lock);
495 sk_for_each(rc, node, &sap->sk_list.list) {
496 struct llc_sock *llc = llc_sk(rc);
498 if (llc->laddr.lsap == laddr->lsap &&
499 llc->daddr.lsap == daddr->lsap &&
500 llc_mac_match(llc->laddr.mac, laddr->mac) &&
501 llc_mac_match(llc->daddr.mac, daddr->mac)) {
502 sock_hold(rc);
503 goto found;
504 }
505 }
506 rc = NULL;
507 found:
508 read_unlock(&sap->sk_list.lock);
509 return rc;
510 }
512 struct sock *llc_lookup_established(struct llc_sap *sap,
513 struct llc_addr *daddr,
514 struct llc_addr *laddr)
515 {
516 struct sock *sk;
518 local_bh_disable();
519 sk = __llc_lookup_established(sap, daddr, laddr);
520 local_bh_enable();
521 return sk;
522 }
524 /**
525 * llc_lookup_listener - Finds listener for local MAC + SAP
526 * @sap: SAP
527 * @laddr: address of local LLC (MAC + SAP)
528 *
529 * Search connection list of the SAP and finds connection listening on
530 * local mac, and local sap. Returns pointer for parent socket found,
531 * %NULL otherwise.
532 * Caller has to make sure local_bh is disabled.
533 */
534 static struct sock *llc_lookup_listener(struct llc_sap *sap,
535 struct llc_addr *laddr)
536 {
537 struct sock *rc;
538 struct hlist_node *node;
540 read_lock(&sap->sk_list.lock);
541 sk_for_each(rc, node, &sap->sk_list.list) {
542 struct llc_sock *llc = llc_sk(rc);
544 if (rc->sk_type == SOCK_STREAM && rc->sk_state == TCP_LISTEN &&
545 llc->laddr.lsap == laddr->lsap &&
546 (llc_mac_match(llc->laddr.mac, laddr->mac) ||
547 llc_mac_null(llc->laddr.mac))) {
548 sock_hold(rc);
549 goto found;
550 }
551 }
552 rc = NULL;
553 found:
554 read_unlock(&sap->sk_list.lock);
555 return rc;
556 }
558 static struct sock *__llc_lookup(struct llc_sap *sap,
559 struct llc_addr *daddr,
560 struct llc_addr *laddr)
561 {
562 struct sock *sk = __llc_lookup_established(sap, daddr, laddr);
564 return sk ? : llc_lookup_listener(sap, laddr);
565 }
567 /**
568 * llc_data_accept_state - designates if in this state data can be sent.
569 * @state: state of connection.
570 *
571 * Returns 0 if data can be sent, 1 otherwise.
572 */
573 u8 llc_data_accept_state(u8 state)
574 {
575 return state != LLC_CONN_STATE_NORMAL && state != LLC_CONN_STATE_BUSY &&
576 state != LLC_CONN_STATE_REJ;
577 }
579 /**
580 * llc_find_next_offset - finds offset for next category of transitions
581 * @state: state table.
582 * @offset: start offset.
583 *
584 * Finds offset of next category of transitions in transition table.
585 * Returns the start index of next category.
586 */
587 static u16 __init llc_find_next_offset(struct llc_conn_state *state, u16 offset)
588 {
589 u16 cnt = 0;
590 struct llc_conn_state_trans **next_trans;
592 for (next_trans = state->transitions + offset;
593 (*next_trans)->ev; next_trans++)
594 ++cnt;
595 return cnt;
596 }
598 /**
599 * llc_build_offset_table - builds offset table of connection
600 *
601 * Fills offset table of connection state transition table
602 * (llc_offset_table).
603 */
604 void __init llc_build_offset_table(void)
605 {
606 struct llc_conn_state *curr_state;
607 int state, ev_type, next_offset;
609 for (state = 0; state < NBR_CONN_STATES; state++) {
610 curr_state = &llc_conn_state_table[state];
611 next_offset = 0;
612 for (ev_type = 0; ev_type < NBR_CONN_EV; ev_type++) {
613 llc_offset_table[state][ev_type] = next_offset;
614 next_offset += llc_find_next_offset(curr_state,
615 next_offset) + 1;
616 }
617 }
618 }
620 /**
621 * llc_find_offset - finds start offset of category of transitions
622 * @state: state of connection
623 * @ev_type: type of happened event
624 *
625 * Finds start offset of desired category of transitions. Returns the
626 * desired start offset.
627 */
628 static int llc_find_offset(int state, int ev_type)
629 {
630 int rc = 0;
631 /* at this stage, llc_offset_table[..][2] is not important. it is for
632 * init_pf_cycle and I don't know what is it.
633 */
634 switch (ev_type) {
635 case LLC_CONN_EV_TYPE_PRIM:
636 rc = llc_offset_table[state][0]; break;
637 case LLC_CONN_EV_TYPE_PDU:
638 rc = llc_offset_table[state][4]; break;
639 case LLC_CONN_EV_TYPE_SIMPLE:
640 rc = llc_offset_table[state][1]; break;
641 case LLC_CONN_EV_TYPE_P_TMR:
642 case LLC_CONN_EV_TYPE_ACK_TMR:
643 case LLC_CONN_EV_TYPE_REJ_TMR:
644 case LLC_CONN_EV_TYPE_BUSY_TMR:
645 rc = llc_offset_table[state][3]; break;
646 }
647 return rc;
648 }
650 /**
651 * llc_sap_add_socket - adds a socket to a SAP
652 * @sap: SAP
653 * @sk: socket
654 *
655 * This function adds a socket to sk_list of a SAP.
656 */
657 void llc_sap_add_socket(struct llc_sap *sap, struct sock *sk)
658 {
659 llc_sap_hold(sap);
660 write_lock_bh(&sap->sk_list.lock);
661 llc_sk(sk)->sap = sap;
662 sk_add_node(sk, &sap->sk_list.list);
663 write_unlock_bh(&sap->sk_list.lock);
664 }
666 /**
667 * llc_sap_remove_socket - removes a socket from SAP
668 * @sap: SAP
669 * @sk: socket
670 *
671 * This function removes a connection from sk_list.list of a SAP if
672 * the connection was in this list.
673 */
674 void llc_sap_remove_socket(struct llc_sap *sap, struct sock *sk)
675 {
676 write_lock_bh(&sap->sk_list.lock);
677 sk_del_node_init(sk);
678 write_unlock_bh(&sap->sk_list.lock);
679 llc_sap_put(sap);
680 }
682 /**
683 * llc_conn_rcv - sends received pdus to the connection state machine
684 * @sk: current connection structure.
685 * @skb: received frame.
686 *
687 * Sends received pdus to the connection state machine.
688 */
689 static int llc_conn_rcv(struct sock* sk, struct sk_buff *skb)
690 {
691 struct llc_conn_state_ev *ev = llc_conn_ev(skb);
693 ev->type = LLC_CONN_EV_TYPE_PDU;
694 ev->reason = 0;
695 return llc_conn_state_process(sk, skb);
696 }
698 static struct sock *llc_create_incoming_sock(struct sock *sk,
699 struct net_device *dev,
700 struct llc_addr *saddr,
701 struct llc_addr *daddr)
702 {
703 struct sock *newsk = llc_sk_alloc(sk->sk_family, GFP_ATOMIC,
704 sk->sk_prot);
705 struct llc_sock *newllc, *llc = llc_sk(sk);
707 if (!newsk)
708 goto out;
709 newllc = llc_sk(newsk);
710 memcpy(&newllc->laddr, daddr, sizeof(newllc->laddr));
711 memcpy(&newllc->daddr, saddr, sizeof(newllc->daddr));
712 newllc->dev = dev;
713 dev_hold(dev);
714 llc_sap_add_socket(llc->sap, newsk);
715 llc_sap_hold(llc->sap);
716 out:
717 return newsk;
718 }
720 void llc_conn_handler(struct llc_sap *sap, struct sk_buff *skb)
721 {
722 struct llc_addr saddr, daddr;
723 struct sock *sk;
725 llc_pdu_decode_sa(skb, saddr.mac);
726 llc_pdu_decode_ssap(skb, &saddr.lsap);
727 llc_pdu_decode_da(skb, daddr.mac);
728 llc_pdu_decode_dsap(skb, &daddr.lsap);
730 sk = __llc_lookup(sap, &saddr, &daddr);
731 if (!sk)
732 goto drop;
734 bh_lock_sock(sk);
735 /*
736 * This has to be done here and not at the upper layer ->accept
737 * method because of the way the PROCOM state machine works:
738 * it needs to set several state variables (see, for instance,
739 * llc_adm_actions_2 in net/llc/llc_c_st.c) and send a packet to
740 * the originator of the new connection, and this state has to be
741 * in the newly created struct sock private area. -acme
742 */
743 if (unlikely(sk->sk_state == TCP_LISTEN)) {
744 struct sock *newsk = llc_create_incoming_sock(sk, skb->dev,
745 &saddr, &daddr);
746 if (!newsk)
747 goto drop_unlock;
748 skb_set_owner_r(skb, newsk);
749 } else {
750 /*
751 * Can't be skb_set_owner_r, this will be done at the
752 * llc_conn_state_process function, later on, when we will use
753 * skb_queue_rcv_skb to send it to upper layers, this is
754 * another trick required to cope with how the PROCOM state
755 * machine works. -acme
756 */
757 skb->sk = sk;
758 }
759 if (!sock_owned_by_user(sk))
760 llc_conn_rcv(sk, skb);
761 else {
762 dprintk("%s: adding to backlog...\n", __FUNCTION__);
763 llc_set_backlog_type(skb, LLC_PACKET);
764 sk_add_backlog(sk, skb);
765 }
766 out:
767 bh_unlock_sock(sk);
768 sock_put(sk);
769 return;
770 drop:
771 kfree_skb(skb);
772 return;
773 drop_unlock:
774 kfree_skb(skb);
775 goto out;
776 }
778 #undef LLC_REFCNT_DEBUG
779 #ifdef LLC_REFCNT_DEBUG
780 static atomic_t llc_sock_nr;
781 #endif
783 /**
784 * llc_backlog_rcv - Processes rx frames and expired timers.
785 * @sk: LLC sock (p8022 connection)
786 * @skb: queued rx frame or event
787 *
788 * This function processes frames that has received and timers that has
789 * expired during sending an I pdu (refer to data_req_handler). frames
790 * queue by llc_rcv function (llc_mac.c) and timers queue by timer
791 * callback functions(llc_c_ac.c).
792 */
793 static int llc_backlog_rcv(struct sock *sk, struct sk_buff *skb)
794 {
795 int rc = 0;
796 struct llc_sock *llc = llc_sk(sk);
798 if (likely(llc_backlog_type(skb) == LLC_PACKET)) {
799 if (likely(llc->state > 1)) /* not closed */
800 rc = llc_conn_rcv(sk, skb);
801 else
802 goto out_kfree_skb;
803 } else if (llc_backlog_type(skb) == LLC_EVENT) {
804 /* timer expiration event */
805 if (likely(llc->state > 1)) /* not closed */
806 rc = llc_conn_state_process(sk, skb);
807 else
808 goto out_kfree_skb;
809 } else {
810 printk(KERN_ERR "%s: invalid skb in backlog\n", __FUNCTION__);
811 goto out_kfree_skb;
812 }
813 out:
814 return rc;
815 out_kfree_skb:
816 kfree_skb(skb);
817 goto out;
818 }
820 /**
821 * llc_sk_init - Initializes a socket with default llc values.
822 * @sk: socket to initialize.
823 *
824 * Initializes a socket with default llc values.
825 */
826 static void llc_sk_init(struct sock* sk)
827 {
828 struct llc_sock *llc = llc_sk(sk);
830 llc->state = LLC_CONN_STATE_ADM;
831 llc->inc_cntr = llc->dec_cntr = 2;
832 llc->dec_step = llc->connect_step = 1;
834 init_timer(&llc->ack_timer.timer);
835 llc->ack_timer.expire = sysctl_llc2_ack_timeout;
836 llc->ack_timer.timer.data = (unsigned long)sk;
837 llc->ack_timer.timer.function = llc_conn_ack_tmr_cb;
839 init_timer(&llc->pf_cycle_timer.timer);
840 llc->pf_cycle_timer.expire = sysctl_llc2_p_timeout;
841 llc->pf_cycle_timer.timer.data = (unsigned long)sk;
842 llc->pf_cycle_timer.timer.function = llc_conn_pf_cycle_tmr_cb;
844 init_timer(&llc->rej_sent_timer.timer);
845 llc->rej_sent_timer.expire = sysctl_llc2_rej_timeout;
846 llc->rej_sent_timer.timer.data = (unsigned long)sk;
847 llc->rej_sent_timer.timer.function = llc_conn_rej_tmr_cb;
849 init_timer(&llc->busy_state_timer.timer);
850 llc->busy_state_timer.expire = sysctl_llc2_busy_timeout;
851 llc->busy_state_timer.timer.data = (unsigned long)sk;
852 llc->busy_state_timer.timer.function = llc_conn_busy_tmr_cb;
854 llc->n2 = 2; /* max retransmit */
855 llc->k = 2; /* tx win size, will adjust dynam */
856 llc->rw = 128; /* rx win size (opt and equal to
857 * tx_win of remote LLC) */
858 skb_queue_head_init(&llc->pdu_unack_q);
859 sk->sk_backlog_rcv = llc_backlog_rcv;
860 }
862 /**
863 * llc_sk_alloc - Allocates LLC sock
864 * @family: upper layer protocol family
865 * @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
866 *
867 * Allocates a LLC sock and initializes it. Returns the new LLC sock
868 * or %NULL if there's no memory available for one
869 */
870 struct sock *llc_sk_alloc(int family, gfp_t priority, struct proto *prot)
871 {
872 struct sock *sk = sk_alloc(family, priority, prot, 1);
874 if (!sk)
875 goto out;
876 llc_sk_init(sk);
877 sock_init_data(NULL, sk);
878 #ifdef LLC_REFCNT_DEBUG
879 atomic_inc(&llc_sock_nr);
880 printk(KERN_DEBUG "LLC socket %p created in %s, now we have %d alive\n", sk,
881 __FUNCTION__, atomic_read(&llc_sock_nr));
882 #endif
883 out:
884 return sk;
885 }
887 /**
888 * llc_sk_free - Frees a LLC socket
889 * @sk - socket to free
890 *
891 * Frees a LLC socket
892 */
893 void llc_sk_free(struct sock *sk)
894 {
895 struct llc_sock *llc = llc_sk(sk);
897 llc->state = LLC_CONN_OUT_OF_SVC;
898 /* Stop all (possibly) running timers */
899 llc_conn_ac_stop_all_timers(sk, NULL);
900 #ifdef DEBUG_LLC_CONN_ALLOC
901 printk(KERN_INFO "%s: unackq=%d, txq=%d\n", __FUNCTION__,
902 skb_queue_len(&llc->pdu_unack_q),
903 skb_queue_len(&sk->sk_write_queue));
904 #endif
905 skb_queue_purge(&sk->sk_receive_queue);
906 skb_queue_purge(&sk->sk_write_queue);
907 skb_queue_purge(&llc->pdu_unack_q);
908 #ifdef LLC_REFCNT_DEBUG
909 if (atomic_read(&sk->sk_refcnt) != 1) {
910 printk(KERN_DEBUG "Destruction of LLC sock %p delayed in %s, cnt=%d\n",
911 sk, __FUNCTION__, atomic_read(&sk->sk_refcnt));
912 printk(KERN_DEBUG "%d LLC sockets are still alive\n",
913 atomic_read(&llc_sock_nr));
914 } else {
915 atomic_dec(&llc_sock_nr);
916 printk(KERN_DEBUG "LLC socket %p released in %s, %d are still alive\n", sk,
917 __FUNCTION__, atomic_read(&llc_sock_nr));
918 }
919 #endif
920 sock_put(sk);
921 }
923 /**
924 * llc_sk_reset - resets a connection
925 * @sk: LLC socket to reset
926 *
927 * Resets a connection to the out of service state. Stops its timers
928 * and frees any frames in the queues of the connection.
929 */
930 void llc_sk_reset(struct sock *sk)
931 {
932 struct llc_sock *llc = llc_sk(sk);
934 llc_conn_ac_stop_all_timers(sk, NULL);
935 skb_queue_purge(&sk->sk_write_queue);
936 skb_queue_purge(&llc->pdu_unack_q);
937 llc->remote_busy_flag = 0;
938 llc->cause_flag = 0;
939 llc->retry_count = 0;
940 llc_conn_set_p_flag(sk, 0);
941 llc->f_flag = 0;
942 llc->s_flag = 0;
943 llc->ack_pf = 0;
944 llc->first_pdu_Ns = 0;
945 llc->ack_must_be_send = 0;
946 llc->dec_step = 1;
947 llc->inc_cntr = 2;
948 llc->dec_cntr = 2;
949 llc->X = 0;
950 llc->failed_data_req = 0 ;
951 llc->last_nr = 0;
952 }