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; | |
d389424e | 61 | struct llc_sock *llc = llc_sk(skb->sk); |
1da177e4 LT |
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; | |
d389424e ACM |
71 | /* |
72 | * Send event to state machine | |
73 | */ | |
74 | rc = llc_conn_service(skb->sk, skb); | |
af426d32 | 75 | if (unlikely(rc != 0)) { |
0dc47877 | 76 | printk(KERN_ERR "%s: llc_conn_service failed\n", __func__); |
1da177e4 LT |
77 | goto out_kfree_skb; |
78 | } | |
79 | ||
af426d32 | 80 | if (unlikely(!ev->ind_prim && !ev->cfm_prim)) { |
1da177e4 | 81 | /* indicate or confirm not required */ |
8728b834 | 82 | if (!skb->next) |
1da177e4 LT |
83 | goto out_kfree_skb; |
84 | goto out_skb_put; | |
85 | } | |
86 | ||
af426d32 | 87 | if (unlikely(ev->ind_prim && ev->cfm_prim)) /* Paranoia */ |
1da177e4 LT |
88 | skb_get(skb); |
89 | ||
90 | switch (ev->ind_prim) { | |
91 | case LLC_DATA_PRIM: | |
04e4223f ACM |
92 | llc_save_primitive(sk, skb, LLC_DATA_PRIM); |
93 | if (unlikely(sock_queue_rcv_skb(sk, skb))) { | |
1da177e4 LT |
94 | /* |
95 | * shouldn't happen | |
96 | */ | |
97 | printk(KERN_ERR "%s: sock_queue_rcv_skb failed!\n", | |
0dc47877 | 98 | __func__); |
1da177e4 LT |
99 | kfree_skb(skb); |
100 | } | |
101 | break; | |
d389424e | 102 | case LLC_CONN_PRIM: |
04e4223f | 103 | /* |
d389424e ACM |
104 | * Can't be sock_queue_rcv_skb, because we have to leave the |
105 | * skb->sk pointing to the newly created struct sock in | |
106 | * llc_conn_handler. -acme | |
04e4223f | 107 | */ |
d389424e ACM |
108 | skb_queue_tail(&sk->sk_receive_queue, skb); |
109 | sk->sk_state_change(sk); | |
1da177e4 LT |
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)) { | |
1da177e4 | 119 | sock_set_flag(sk, SOCK_DEAD); |
8420e1b5 | 120 | sk->sk_state_change(sk); |
1da177e4 LT |
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 | */ | |
0dc47877 | 131 | printk(KERN_INFO "%s: received a reset ind!\n", __func__); |
1da177e4 LT |
132 | kfree_skb(skb); |
133 | break; | |
134 | default: | |
135 | if (ev->ind_prim) { | |
136 | printk(KERN_INFO "%s: received unknown %d prim!\n", | |
0dc47877 | 137 | __func__, ev->ind_prim); |
1da177e4 LT |
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 | */ | |
0dc47877 | 178 | printk(KERN_INFO "%s: received a reset conf!\n", __func__); |
1da177e4 LT |
179 | break; |
180 | default: | |
181 | if (ev->cfm_prim) { | |
182 | printk(KERN_INFO "%s: received unknown %d prim!\n", | |
0dc47877 | 183 | __func__, ev->cfm_prim); |
1da177e4 LT |
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); | |
c3431ea7 | 331 | kfree_skb(skb); |
1da177e4 LT |
332 | nbr_acked++; |
333 | } | |
334 | out: | |
335 | *how_many_unacked = skb_queue_len(&llc->pdu_unack_q); | |
336 | return nbr_acked; | |
337 | } | |
338 | ||
339 | /** | |
340 | * llc_conn_send_pdus - Sends queued PDUs | |
341 | * @sk: active connection | |
342 | * | |
343 | * Sends queued pdus to MAC layer for transmission. | |
344 | */ | |
345 | static void llc_conn_send_pdus(struct sock *sk) | |
346 | { | |
347 | struct sk_buff *skb; | |
348 | ||
349 | while ((skb = skb_dequeue(&sk->sk_write_queue)) != NULL) { | |
350 | struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb); | |
351 | ||
352 | if (LLC_PDU_TYPE_IS_I(pdu) && | |
353 | !(skb->dev->flags & IFF_LOOPBACK)) { | |
354 | struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); | |
355 | ||
356 | skb_queue_tail(&llc_sk(sk)->pdu_unack_q, skb); | |
357 | if (!skb2) | |
358 | break; | |
359 | skb = skb2; | |
360 | } | |
361 | dev_queue_xmit(skb); | |
362 | } | |
363 | } | |
364 | ||
365 | /** | |
366 | * llc_conn_service - finds transition and changes state of connection | |
367 | * @sk: connection | |
368 | * @skb: happened event | |
369 | * | |
370 | * This function finds transition that matches with happened event, then | |
371 | * executes related actions and finally changes state of connection. | |
372 | * Returns 0 for success, 1 for failure. | |
373 | */ | |
374 | static int llc_conn_service(struct sock *sk, struct sk_buff *skb) | |
375 | { | |
376 | int rc = 1; | |
377 | struct llc_sock *llc = llc_sk(sk); | |
378 | struct llc_conn_state_trans *trans; | |
379 | ||
380 | if (llc->state > NBR_CONN_STATES) | |
381 | goto out; | |
382 | rc = 0; | |
383 | trans = llc_qualify_conn_ev(sk, skb); | |
384 | if (trans) { | |
385 | rc = llc_exec_conn_trans_actions(sk, trans, skb); | |
386 | if (!rc && trans->next_state != NO_STATE_CHANGE) { | |
387 | llc->state = trans->next_state; | |
388 | if (!llc_data_accept_state(llc->state)) | |
389 | sk->sk_state_change(sk); | |
390 | } | |
391 | } | |
392 | out: | |
393 | return rc; | |
394 | } | |
395 | ||
396 | /** | |
397 | * llc_qualify_conn_ev - finds transition for event | |
398 | * @sk: connection | |
399 | * @skb: happened event | |
400 | * | |
401 | * This function finds transition that matches with happened event. | |
402 | * Returns pointer to found transition on success, %NULL otherwise. | |
403 | */ | |
404 | static struct llc_conn_state_trans *llc_qualify_conn_ev(struct sock *sk, | |
405 | struct sk_buff *skb) | |
406 | { | |
407 | struct llc_conn_state_trans **next_trans; | |
408 | llc_conn_ev_qfyr_t *next_qualifier; | |
409 | struct llc_conn_state_ev *ev = llc_conn_ev(skb); | |
410 | struct llc_sock *llc = llc_sk(sk); | |
411 | struct llc_conn_state *curr_state = | |
412 | &llc_conn_state_table[llc->state - 1]; | |
413 | ||
414 | /* search thru events for this state until | |
415 | * list exhausted or until no more | |
416 | */ | |
417 | for (next_trans = curr_state->transitions + | |
418 | llc_find_offset(llc->state - 1, ev->type); | |
419 | (*next_trans)->ev; next_trans++) { | |
420 | if (!((*next_trans)->ev)(sk, skb)) { | |
421 | /* got POSSIBLE event match; the event may require | |
422 | * qualification based on the values of a number of | |
423 | * state flags; if all qualifications are met (i.e., | |
424 | * if all qualifying functions return success, or 0, | |
425 | * then this is THE event we're looking for | |
426 | */ | |
427 | for (next_qualifier = (*next_trans)->ev_qualifiers; | |
428 | next_qualifier && *next_qualifier && | |
429 | !(*next_qualifier)(sk, skb); next_qualifier++) | |
430 | /* nothing */; | |
431 | if (!next_qualifier || !*next_qualifier) | |
432 | /* all qualifiers executed successfully; this is | |
433 | * our transition; return it so we can perform | |
434 | * the associated actions & change the state | |
435 | */ | |
436 | return *next_trans; | |
437 | } | |
438 | } | |
439 | return NULL; | |
440 | } | |
441 | ||
442 | /** | |
443 | * llc_exec_conn_trans_actions - executes related actions | |
444 | * @sk: connection | |
445 | * @trans: transition that it's actions must be performed | |
446 | * @skb: event | |
447 | * | |
448 | * Executes actions that is related to happened event. Returns 0 for | |
449 | * success, 1 to indicate failure of at least one action. | |
450 | */ | |
451 | static int llc_exec_conn_trans_actions(struct sock *sk, | |
452 | struct llc_conn_state_trans *trans, | |
453 | struct sk_buff *skb) | |
454 | { | |
455 | int rc = 0; | |
456 | llc_conn_action_t *next_action; | |
457 | ||
458 | for (next_action = trans->ev_actions; | |
459 | next_action && *next_action; next_action++) { | |
460 | int rc2 = (*next_action)(sk, skb); | |
461 | ||
462 | if (rc2 == 2) { | |
463 | rc = rc2; | |
464 | break; | |
465 | } else if (rc2) | |
466 | rc = 1; | |
467 | } | |
468 | return rc; | |
469 | } | |
470 | ||
471 | /** | |
d389424e | 472 | * __llc_lookup_established - Finds connection for the remote/local sap/mac |
1da177e4 LT |
473 | * @sap: SAP |
474 | * @daddr: address of remote LLC (MAC + SAP) | |
475 | * @laddr: address of local LLC (MAC + SAP) | |
476 | * | |
477 | * Search connection list of the SAP and finds connection using the remote | |
478 | * mac, remote sap, local mac, and local sap. Returns pointer for | |
479 | * connection found, %NULL otherwise. | |
d389424e | 480 | * Caller has to make sure local_bh is disabled. |
1da177e4 | 481 | */ |
d389424e ACM |
482 | static struct sock *__llc_lookup_established(struct llc_sap *sap, |
483 | struct llc_addr *daddr, | |
484 | struct llc_addr *laddr) | |
1da177e4 LT |
485 | { |
486 | struct sock *rc; | |
487 | struct hlist_node *node; | |
488 | ||
d389424e | 489 | read_lock(&sap->sk_list.lock); |
1da177e4 LT |
490 | sk_for_each(rc, node, &sap->sk_list.list) { |
491 | struct llc_sock *llc = llc_sk(rc); | |
492 | ||
493 | if (llc->laddr.lsap == laddr->lsap && | |
494 | llc->daddr.lsap == daddr->lsap && | |
495 | llc_mac_match(llc->laddr.mac, laddr->mac) && | |
496 | llc_mac_match(llc->daddr.mac, daddr->mac)) { | |
497 | sock_hold(rc); | |
498 | goto found; | |
499 | } | |
500 | } | |
501 | rc = NULL; | |
502 | found: | |
d389424e | 503 | read_unlock(&sap->sk_list.lock); |
1da177e4 LT |
504 | return rc; |
505 | } | |
506 | ||
d389424e ACM |
507 | struct sock *llc_lookup_established(struct llc_sap *sap, |
508 | struct llc_addr *daddr, | |
509 | struct llc_addr *laddr) | |
510 | { | |
511 | struct sock *sk; | |
512 | ||
513 | local_bh_disable(); | |
514 | sk = __llc_lookup_established(sap, daddr, laddr); | |
515 | local_bh_enable(); | |
516 | return sk; | |
517 | } | |
518 | ||
1da177e4 LT |
519 | /** |
520 | * llc_lookup_listener - Finds listener for local MAC + SAP | |
521 | * @sap: SAP | |
522 | * @laddr: address of local LLC (MAC + SAP) | |
523 | * | |
524 | * Search connection list of the SAP and finds connection listening on | |
525 | * local mac, and local sap. Returns pointer for parent socket found, | |
526 | * %NULL otherwise. | |
d389424e | 527 | * Caller has to make sure local_bh is disabled. |
1da177e4 LT |
528 | */ |
529 | static struct sock *llc_lookup_listener(struct llc_sap *sap, | |
530 | struct llc_addr *laddr) | |
531 | { | |
532 | struct sock *rc; | |
533 | struct hlist_node *node; | |
534 | ||
d389424e | 535 | read_lock(&sap->sk_list.lock); |
1da177e4 LT |
536 | sk_for_each(rc, node, &sap->sk_list.list) { |
537 | struct llc_sock *llc = llc_sk(rc); | |
538 | ||
539 | if (rc->sk_type == SOCK_STREAM && rc->sk_state == TCP_LISTEN && | |
540 | llc->laddr.lsap == laddr->lsap && | |
541 | (llc_mac_match(llc->laddr.mac, laddr->mac) || | |
542 | llc_mac_null(llc->laddr.mac))) { | |
543 | sock_hold(rc); | |
544 | goto found; | |
545 | } | |
546 | } | |
547 | rc = NULL; | |
548 | found: | |
d389424e | 549 | read_unlock(&sap->sk_list.lock); |
1da177e4 LT |
550 | return rc; |
551 | } | |
552 | ||
d389424e ACM |
553 | static struct sock *__llc_lookup(struct llc_sap *sap, |
554 | struct llc_addr *daddr, | |
555 | struct llc_addr *laddr) | |
556 | { | |
557 | struct sock *sk = __llc_lookup_established(sap, daddr, laddr); | |
558 | ||
559 | return sk ? : llc_lookup_listener(sap, laddr); | |
560 | } | |
561 | ||
1da177e4 LT |
562 | /** |
563 | * llc_data_accept_state - designates if in this state data can be sent. | |
564 | * @state: state of connection. | |
565 | * | |
566 | * Returns 0 if data can be sent, 1 otherwise. | |
567 | */ | |
568 | u8 llc_data_accept_state(u8 state) | |
569 | { | |
570 | return state != LLC_CONN_STATE_NORMAL && state != LLC_CONN_STATE_BUSY && | |
571 | state != LLC_CONN_STATE_REJ; | |
572 | } | |
573 | ||
574 | /** | |
0eb80172 | 575 | * llc_find_next_offset - finds offset for next category of transitions |
1da177e4 LT |
576 | * @state: state table. |
577 | * @offset: start offset. | |
578 | * | |
579 | * Finds offset of next category of transitions in transition table. | |
580 | * Returns the start index of next category. | |
581 | */ | |
0eb80172 | 582 | static u16 __init llc_find_next_offset(struct llc_conn_state *state, u16 offset) |
1da177e4 LT |
583 | { |
584 | u16 cnt = 0; | |
585 | struct llc_conn_state_trans **next_trans; | |
586 | ||
587 | for (next_trans = state->transitions + offset; | |
588 | (*next_trans)->ev; next_trans++) | |
589 | ++cnt; | |
590 | return cnt; | |
591 | } | |
592 | ||
593 | /** | |
594 | * llc_build_offset_table - builds offset table of connection | |
595 | * | |
596 | * Fills offset table of connection state transition table | |
597 | * (llc_offset_table). | |
598 | */ | |
599 | void __init llc_build_offset_table(void) | |
600 | { | |
601 | struct llc_conn_state *curr_state; | |
602 | int state, ev_type, next_offset; | |
603 | ||
604 | for (state = 0; state < NBR_CONN_STATES; state++) { | |
605 | curr_state = &llc_conn_state_table[state]; | |
606 | next_offset = 0; | |
607 | for (ev_type = 0; ev_type < NBR_CONN_EV; ev_type++) { | |
608 | llc_offset_table[state][ev_type] = next_offset; | |
0eb80172 ACM |
609 | next_offset += llc_find_next_offset(curr_state, |
610 | next_offset) + 1; | |
1da177e4 LT |
611 | } |
612 | } | |
613 | } | |
614 | ||
615 | /** | |
616 | * llc_find_offset - finds start offset of category of transitions | |
617 | * @state: state of connection | |
618 | * @ev_type: type of happened event | |
619 | * | |
620 | * Finds start offset of desired category of transitions. Returns the | |
621 | * desired start offset. | |
622 | */ | |
623 | static int llc_find_offset(int state, int ev_type) | |
624 | { | |
625 | int rc = 0; | |
626 | /* at this stage, llc_offset_table[..][2] is not important. it is for | |
627 | * init_pf_cycle and I don't know what is it. | |
628 | */ | |
629 | switch (ev_type) { | |
630 | case LLC_CONN_EV_TYPE_PRIM: | |
631 | rc = llc_offset_table[state][0]; break; | |
632 | case LLC_CONN_EV_TYPE_PDU: | |
633 | rc = llc_offset_table[state][4]; break; | |
634 | case LLC_CONN_EV_TYPE_SIMPLE: | |
635 | rc = llc_offset_table[state][1]; break; | |
636 | case LLC_CONN_EV_TYPE_P_TMR: | |
637 | case LLC_CONN_EV_TYPE_ACK_TMR: | |
638 | case LLC_CONN_EV_TYPE_REJ_TMR: | |
639 | case LLC_CONN_EV_TYPE_BUSY_TMR: | |
640 | rc = llc_offset_table[state][3]; break; | |
641 | } | |
642 | return rc; | |
643 | } | |
644 | ||
645 | /** | |
646 | * llc_sap_add_socket - adds a socket to a SAP | |
647 | * @sap: SAP | |
648 | * @sk: socket | |
649 | * | |
650 | * This function adds a socket to sk_list of a SAP. | |
651 | */ | |
652 | void llc_sap_add_socket(struct llc_sap *sap, struct sock *sk) | |
653 | { | |
6e2144b7 | 654 | llc_sap_hold(sap); |
1da177e4 LT |
655 | write_lock_bh(&sap->sk_list.lock); |
656 | llc_sk(sk)->sap = sap; | |
657 | sk_add_node(sk, &sap->sk_list.list); | |
658 | write_unlock_bh(&sap->sk_list.lock); | |
659 | } | |
660 | ||
661 | /** | |
662 | * llc_sap_remove_socket - removes a socket from SAP | |
663 | * @sap: SAP | |
664 | * @sk: socket | |
665 | * | |
666 | * This function removes a connection from sk_list.list of a SAP if | |
667 | * the connection was in this list. | |
668 | */ | |
669 | void llc_sap_remove_socket(struct llc_sap *sap, struct sock *sk) | |
670 | { | |
671 | write_lock_bh(&sap->sk_list.lock); | |
672 | sk_del_node_init(sk); | |
673 | write_unlock_bh(&sap->sk_list.lock); | |
6e2144b7 | 674 | llc_sap_put(sap); |
1da177e4 LT |
675 | } |
676 | ||
677 | /** | |
678 | * llc_conn_rcv - sends received pdus to the connection state machine | |
679 | * @sk: current connection structure. | |
680 | * @skb: received frame. | |
681 | * | |
682 | * Sends received pdus to the connection state machine. | |
683 | */ | |
684 | static int llc_conn_rcv(struct sock* sk, struct sk_buff *skb) | |
685 | { | |
686 | struct llc_conn_state_ev *ev = llc_conn_ev(skb); | |
1da177e4 | 687 | |
1da177e4 LT |
688 | ev->type = LLC_CONN_EV_TYPE_PDU; |
689 | ev->reason = 0; | |
690 | return llc_conn_state_process(sk, skb); | |
691 | } | |
692 | ||
d389424e ACM |
693 | static struct sock *llc_create_incoming_sock(struct sock *sk, |
694 | struct net_device *dev, | |
695 | struct llc_addr *saddr, | |
696 | struct llc_addr *daddr) | |
697 | { | |
3b1e0a65 | 698 | struct sock *newsk = llc_sk_alloc(sock_net(sk), sk->sk_family, GFP_ATOMIC, |
d389424e ACM |
699 | sk->sk_prot); |
700 | struct llc_sock *newllc, *llc = llc_sk(sk); | |
701 | ||
702 | if (!newsk) | |
703 | goto out; | |
704 | newllc = llc_sk(newsk); | |
705 | memcpy(&newllc->laddr, daddr, sizeof(newllc->laddr)); | |
706 | memcpy(&newllc->daddr, saddr, sizeof(newllc->daddr)); | |
707 | newllc->dev = dev; | |
708 | dev_hold(dev); | |
709 | llc_sap_add_socket(llc->sap, newsk); | |
710 | llc_sap_hold(llc->sap); | |
711 | out: | |
712 | return newsk; | |
713 | } | |
714 | ||
1da177e4 LT |
715 | void llc_conn_handler(struct llc_sap *sap, struct sk_buff *skb) |
716 | { | |
717 | struct llc_addr saddr, daddr; | |
718 | struct sock *sk; | |
719 | ||
720 | llc_pdu_decode_sa(skb, saddr.mac); | |
721 | llc_pdu_decode_ssap(skb, &saddr.lsap); | |
722 | llc_pdu_decode_da(skb, daddr.mac); | |
723 | llc_pdu_decode_dsap(skb, &daddr.lsap); | |
724 | ||
d389424e ACM |
725 | sk = __llc_lookup(sap, &saddr, &daddr); |
726 | if (!sk) | |
727 | goto drop; | |
728 | ||
729 | bh_lock_sock(sk); | |
730 | /* | |
731 | * This has to be done here and not at the upper layer ->accept | |
732 | * method because of the way the PROCOM state machine works: | |
733 | * it needs to set several state variables (see, for instance, | |
734 | * llc_adm_actions_2 in net/llc/llc_c_st.c) and send a packet to | |
735 | * the originator of the new connection, and this state has to be | |
736 | * in the newly created struct sock private area. -acme | |
737 | */ | |
738 | if (unlikely(sk->sk_state == TCP_LISTEN)) { | |
739 | struct sock *newsk = llc_create_incoming_sock(sk, skb->dev, | |
740 | &saddr, &daddr); | |
741 | if (!newsk) | |
742 | goto drop_unlock; | |
743 | skb_set_owner_r(skb, newsk); | |
744 | } else { | |
1da177e4 | 745 | /* |
d389424e ACM |
746 | * Can't be skb_set_owner_r, this will be done at the |
747 | * llc_conn_state_process function, later on, when we will use | |
748 | * skb_queue_rcv_skb to send it to upper layers, this is | |
749 | * another trick required to cope with how the PROCOM state | |
750 | * machine works. -acme | |
1da177e4 | 751 | */ |
d389424e | 752 | skb->sk = sk; |
04e4223f | 753 | } |
1da177e4 LT |
754 | if (!sock_owned_by_user(sk)) |
755 | llc_conn_rcv(sk, skb); | |
756 | else { | |
0dc47877 | 757 | dprintk("%s: adding to backlog...\n", __func__); |
1da177e4 LT |
758 | llc_set_backlog_type(skb, LLC_PACKET); |
759 | sk_add_backlog(sk, skb); | |
760 | } | |
d389424e | 761 | out: |
1da177e4 LT |
762 | bh_unlock_sock(sk); |
763 | sock_put(sk); | |
764 | return; | |
765 | drop: | |
766 | kfree_skb(skb); | |
d389424e ACM |
767 | return; |
768 | drop_unlock: | |
769 | kfree_skb(skb); | |
770 | goto out; | |
1da177e4 LT |
771 | } |
772 | ||
773 | #undef LLC_REFCNT_DEBUG | |
774 | #ifdef LLC_REFCNT_DEBUG | |
775 | static atomic_t llc_sock_nr; | |
776 | #endif | |
777 | ||
1da177e4 LT |
778 | /** |
779 | * llc_backlog_rcv - Processes rx frames and expired timers. | |
780 | * @sk: LLC sock (p8022 connection) | |
781 | * @skb: queued rx frame or event | |
782 | * | |
783 | * This function processes frames that has received and timers that has | |
784 | * expired during sending an I pdu (refer to data_req_handler). frames | |
785 | * queue by llc_rcv function (llc_mac.c) and timers queue by timer | |
786 | * callback functions(llc_c_ac.c). | |
787 | */ | |
788 | static int llc_backlog_rcv(struct sock *sk, struct sk_buff *skb) | |
789 | { | |
790 | int rc = 0; | |
791 | struct llc_sock *llc = llc_sk(sk); | |
792 | ||
af426d32 ACM |
793 | if (likely(llc_backlog_type(skb) == LLC_PACKET)) { |
794 | if (likely(llc->state > 1)) /* not closed */ | |
1da177e4 LT |
795 | rc = llc_conn_rcv(sk, skb); |
796 | else | |
797 | goto out_kfree_skb; | |
798 | } else if (llc_backlog_type(skb) == LLC_EVENT) { | |
799 | /* timer expiration event */ | |
af426d32 | 800 | if (likely(llc->state > 1)) /* not closed */ |
1da177e4 LT |
801 | rc = llc_conn_state_process(sk, skb); |
802 | else | |
803 | goto out_kfree_skb; | |
804 | } else { | |
0dc47877 | 805 | printk(KERN_ERR "%s: invalid skb in backlog\n", __func__); |
1da177e4 LT |
806 | goto out_kfree_skb; |
807 | } | |
808 | out: | |
809 | return rc; | |
810 | out_kfree_skb: | |
811 | kfree_skb(skb); | |
812 | goto out; | |
813 | } | |
814 | ||
815 | /** | |
816 | * llc_sk_init - Initializes a socket with default llc values. | |
817 | * @sk: socket to initialize. | |
818 | * | |
819 | * Initializes a socket with default llc values. | |
820 | */ | |
821 | static void llc_sk_init(struct sock* sk) | |
822 | { | |
823 | struct llc_sock *llc = llc_sk(sk); | |
824 | ||
825 | llc->state = LLC_CONN_STATE_ADM; | |
826 | llc->inc_cntr = llc->dec_cntr = 2; | |
827 | llc->dec_step = llc->connect_step = 1; | |
828 | ||
b24b8a24 PE |
829 | setup_timer(&llc->ack_timer.timer, llc_conn_ack_tmr_cb, |
830 | (unsigned long)sk); | |
590232a7 | 831 | llc->ack_timer.expire = sysctl_llc2_ack_timeout; |
1da177e4 | 832 | |
b24b8a24 PE |
833 | setup_timer(&llc->pf_cycle_timer.timer, llc_conn_pf_cycle_tmr_cb, |
834 | (unsigned long)sk); | |
590232a7 | 835 | llc->pf_cycle_timer.expire = sysctl_llc2_p_timeout; |
1da177e4 | 836 | |
b24b8a24 PE |
837 | setup_timer(&llc->rej_sent_timer.timer, llc_conn_rej_tmr_cb, |
838 | (unsigned long)sk); | |
590232a7 | 839 | llc->rej_sent_timer.expire = sysctl_llc2_rej_timeout; |
1da177e4 | 840 | |
b24b8a24 PE |
841 | setup_timer(&llc->busy_state_timer.timer, llc_conn_busy_tmr_cb, |
842 | (unsigned long)sk); | |
590232a7 | 843 | llc->busy_state_timer.expire = sysctl_llc2_busy_timeout; |
1da177e4 LT |
844 | |
845 | llc->n2 = 2; /* max retransmit */ | |
846 | llc->k = 2; /* tx win size, will adjust dynam */ | |
847 | llc->rw = 128; /* rx win size (opt and equal to | |
d57b1869 | 848 | * tx_win of remote LLC) */ |
1da177e4 LT |
849 | skb_queue_head_init(&llc->pdu_unack_q); |
850 | sk->sk_backlog_rcv = llc_backlog_rcv; | |
851 | } | |
852 | ||
853 | /** | |
854 | * llc_sk_alloc - Allocates LLC sock | |
855 | * @family: upper layer protocol family | |
856 | * @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc) | |
857 | * | |
858 | * Allocates a LLC sock and initializes it. Returns the new LLC sock | |
859 | * or %NULL if there's no memory available for one | |
860 | */ | |
1b8d7ae4 | 861 | struct sock *llc_sk_alloc(struct net *net, int family, gfp_t priority, struct proto *prot) |
1da177e4 | 862 | { |
6257ff21 | 863 | struct sock *sk = sk_alloc(net, family, priority, prot); |
1da177e4 LT |
864 | |
865 | if (!sk) | |
866 | goto out; | |
867 | llc_sk_init(sk); | |
868 | sock_init_data(NULL, sk); | |
869 | #ifdef LLC_REFCNT_DEBUG | |
870 | atomic_inc(&llc_sock_nr); | |
871 | printk(KERN_DEBUG "LLC socket %p created in %s, now we have %d alive\n", sk, | |
0dc47877 | 872 | __func__, atomic_read(&llc_sock_nr)); |
1da177e4 LT |
873 | #endif |
874 | out: | |
875 | return sk; | |
876 | } | |
877 | ||
878 | /** | |
879 | * llc_sk_free - Frees a LLC socket | |
880 | * @sk - socket to free | |
881 | * | |
882 | * Frees a LLC socket | |
883 | */ | |
884 | void llc_sk_free(struct sock *sk) | |
885 | { | |
886 | struct llc_sock *llc = llc_sk(sk); | |
887 | ||
888 | llc->state = LLC_CONN_OUT_OF_SVC; | |
889 | /* Stop all (possibly) running timers */ | |
890 | llc_conn_ac_stop_all_timers(sk, NULL); | |
891 | #ifdef DEBUG_LLC_CONN_ALLOC | |
0dc47877 | 892 | printk(KERN_INFO "%s: unackq=%d, txq=%d\n", __func__, |
1da177e4 LT |
893 | skb_queue_len(&llc->pdu_unack_q), |
894 | skb_queue_len(&sk->sk_write_queue)); | |
895 | #endif | |
896 | skb_queue_purge(&sk->sk_receive_queue); | |
897 | skb_queue_purge(&sk->sk_write_queue); | |
898 | skb_queue_purge(&llc->pdu_unack_q); | |
899 | #ifdef LLC_REFCNT_DEBUG | |
900 | if (atomic_read(&sk->sk_refcnt) != 1) { | |
901 | printk(KERN_DEBUG "Destruction of LLC sock %p delayed in %s, cnt=%d\n", | |
0dc47877 | 902 | sk, __func__, atomic_read(&sk->sk_refcnt)); |
1da177e4 LT |
903 | printk(KERN_DEBUG "%d LLC sockets are still alive\n", |
904 | atomic_read(&llc_sock_nr)); | |
905 | } else { | |
906 | atomic_dec(&llc_sock_nr); | |
907 | printk(KERN_DEBUG "LLC socket %p released in %s, %d are still alive\n", sk, | |
0dc47877 | 908 | __func__, atomic_read(&llc_sock_nr)); |
1da177e4 LT |
909 | } |
910 | #endif | |
911 | sock_put(sk); | |
912 | } | |
913 | ||
914 | /** | |
915 | * llc_sk_reset - resets a connection | |
916 | * @sk: LLC socket to reset | |
917 | * | |
918 | * Resets a connection to the out of service state. Stops its timers | |
919 | * and frees any frames in the queues of the connection. | |
920 | */ | |
921 | void llc_sk_reset(struct sock *sk) | |
922 | { | |
923 | struct llc_sock *llc = llc_sk(sk); | |
924 | ||
925 | llc_conn_ac_stop_all_timers(sk, NULL); | |
926 | skb_queue_purge(&sk->sk_write_queue); | |
927 | skb_queue_purge(&llc->pdu_unack_q); | |
928 | llc->remote_busy_flag = 0; | |
929 | llc->cause_flag = 0; | |
930 | llc->retry_count = 0; | |
931 | llc_conn_set_p_flag(sk, 0); | |
932 | llc->f_flag = 0; | |
933 | llc->s_flag = 0; | |
934 | llc->ack_pf = 0; | |
935 | llc->first_pdu_Ns = 0; | |
936 | llc->ack_must_be_send = 0; | |
937 | llc->dec_step = 1; | |
938 | llc->inc_cntr = 2; | |
939 | llc->dec_cntr = 2; | |
940 | llc->X = 0; | |
941 | llc->failed_data_req = 0 ; | |
942 | llc->last_nr = 0; | |
943 | } |