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> | |
5a0e3ad6 | 16 | #include <linux/slab.h> |
1da177e4 LT |
17 | #include <net/llc_sap.h> |
18 | #include <net/llc_conn.h> | |
19 | #include <net/sock.h> | |
c752f073 | 20 | #include <net/tcp_states.h> |
1da177e4 LT |
21 | #include <net/llc_c_ev.h> |
22 | #include <net/llc_c_ac.h> | |
23 | #include <net/llc_c_st.h> | |
24 | #include <net/llc_pdu.h> | |
25 | ||
26 | #if 0 | |
27 | #define dprintk(args...) printk(KERN_DEBUG args) | |
28 | #else | |
29 | #define dprintk(args...) | |
30 | #endif | |
31 | ||
32 | static int llc_find_offset(int state, int ev_type); | |
33 | static void llc_conn_send_pdus(struct sock *sk); | |
34 | static int llc_conn_service(struct sock *sk, struct sk_buff *skb); | |
35 | static int llc_exec_conn_trans_actions(struct sock *sk, | |
36 | struct llc_conn_state_trans *trans, | |
37 | struct sk_buff *ev); | |
38 | static struct llc_conn_state_trans *llc_qualify_conn_ev(struct sock *sk, | |
39 | struct sk_buff *skb); | |
40 | ||
41 | /* Offset table on connection states transition diagram */ | |
42 | static int llc_offset_table[NBR_CONN_STATES][NBR_CONN_EV]; | |
43 | ||
590232a7 ACM |
44 | int sysctl_llc2_ack_timeout = LLC2_ACK_TIME * HZ; |
45 | int sysctl_llc2_p_timeout = LLC2_P_TIME * HZ; | |
46 | int sysctl_llc2_rej_timeout = LLC2_REJ_TIME * HZ; | |
47 | int sysctl_llc2_busy_timeout = LLC2_BUSY_TIME * HZ; | |
48 | ||
1da177e4 LT |
49 | /** |
50 | * llc_conn_state_process - sends event to connection state machine | |
51 | * @sk: connection | |
52 | * @skb: occurred event | |
53 | * | |
54 | * Sends an event to connection state machine. After processing event | |
55 | * (executing it's actions and changing state), upper layer will be | |
56 | * indicated or confirmed, if needed. Returns 0 for success, 1 for | |
57 | * failure. The socket lock has to be held before calling this function. | |
58 | */ | |
59 | int llc_conn_state_process(struct sock *sk, struct sk_buff *skb) | |
60 | { | |
61 | int rc; | |
d389424e | 62 | struct llc_sock *llc = llc_sk(skb->sk); |
1da177e4 LT |
63 | struct llc_conn_state_ev *ev = llc_conn_ev(skb); |
64 | ||
65 | /* | |
66 | * We have to hold the skb, because llc_conn_service will kfree it in | |
67 | * the sending path and we need to look at the skb->cb, where we encode | |
68 | * llc_conn_state_ev. | |
69 | */ | |
70 | skb_get(skb); | |
71 | ev->ind_prim = ev->cfm_prim = 0; | |
d389424e ACM |
72 | /* |
73 | * Send event to state machine | |
74 | */ | |
75 | rc = llc_conn_service(skb->sk, skb); | |
af426d32 | 76 | if (unlikely(rc != 0)) { |
0dc47877 | 77 | printk(KERN_ERR "%s: llc_conn_service failed\n", __func__); |
1da177e4 LT |
78 | goto out_kfree_skb; |
79 | } | |
80 | ||
af426d32 | 81 | if (unlikely(!ev->ind_prim && !ev->cfm_prim)) { |
1da177e4 | 82 | /* indicate or confirm not required */ |
8728b834 | 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: | |
04e4223f ACM |
93 | llc_save_primitive(sk, skb, LLC_DATA_PRIM); |
94 | if (unlikely(sock_queue_rcv_skb(sk, skb))) { | |
1da177e4 LT |
95 | /* |
96 | * shouldn't happen | |
97 | */ | |
98 | printk(KERN_ERR "%s: sock_queue_rcv_skb failed!\n", | |
0dc47877 | 99 | __func__); |
1da177e4 LT |
100 | kfree_skb(skb); |
101 | } | |
102 | break; | |
d389424e | 103 | case LLC_CONN_PRIM: |
04e4223f | 104 | /* |
d389424e ACM |
105 | * Can't be sock_queue_rcv_skb, because we have to leave the |
106 | * skb->sk pointing to the newly created struct sock in | |
107 | * llc_conn_handler. -acme | |
04e4223f | 108 | */ |
d389424e ACM |
109 | skb_queue_tail(&sk->sk_receive_queue, skb); |
110 | sk->sk_state_change(sk); | |
1da177e4 LT |
111 | break; |
112 | case LLC_DISC_PRIM: | |
113 | sock_hold(sk); | |
114 | if (sk->sk_type == SOCK_STREAM && | |
115 | sk->sk_state == TCP_ESTABLISHED) { | |
116 | sk->sk_shutdown = SHUTDOWN_MASK; | |
117 | sk->sk_socket->state = SS_UNCONNECTED; | |
118 | sk->sk_state = TCP_CLOSE; | |
119 | if (!sock_flag(sk, SOCK_DEAD)) { | |
1da177e4 | 120 | sock_set_flag(sk, SOCK_DEAD); |
8420e1b5 | 121 | sk->sk_state_change(sk); |
1da177e4 LT |
122 | } |
123 | } | |
124 | kfree_skb(skb); | |
125 | sock_put(sk); | |
126 | break; | |
127 | case LLC_RESET_PRIM: | |
128 | /* | |
129 | * FIXME: | |
130 | * RESET is not being notified to upper layers for now | |
131 | */ | |
0dc47877 | 132 | printk(KERN_INFO "%s: received a reset ind!\n", __func__); |
1da177e4 LT |
133 | kfree_skb(skb); |
134 | break; | |
135 | default: | |
136 | if (ev->ind_prim) { | |
137 | printk(KERN_INFO "%s: received unknown %d prim!\n", | |
0dc47877 | 138 | __func__, ev->ind_prim); |
1da177e4 LT |
139 | kfree_skb(skb); |
140 | } | |
141 | /* No indication */ | |
142 | break; | |
143 | } | |
144 | ||
145 | switch (ev->cfm_prim) { | |
146 | case LLC_DATA_PRIM: | |
147 | if (!llc_data_accept_state(llc->state)) | |
148 | sk->sk_write_space(sk); | |
149 | else | |
150 | rc = llc->failed_data_req = 1; | |
151 | break; | |
152 | case LLC_CONN_PRIM: | |
153 | if (sk->sk_type == SOCK_STREAM && | |
154 | sk->sk_state == TCP_SYN_SENT) { | |
155 | if (ev->status) { | |
156 | sk->sk_socket->state = SS_UNCONNECTED; | |
157 | sk->sk_state = TCP_CLOSE; | |
158 | } else { | |
159 | sk->sk_socket->state = SS_CONNECTED; | |
160 | sk->sk_state = TCP_ESTABLISHED; | |
161 | } | |
162 | sk->sk_state_change(sk); | |
163 | } | |
164 | break; | |
165 | case LLC_DISC_PRIM: | |
166 | sock_hold(sk); | |
167 | if (sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_CLOSING) { | |
168 | sk->sk_socket->state = SS_UNCONNECTED; | |
169 | sk->sk_state = TCP_CLOSE; | |
170 | sk->sk_state_change(sk); | |
171 | } | |
172 | sock_put(sk); | |
173 | break; | |
174 | case LLC_RESET_PRIM: | |
175 | /* | |
176 | * FIXME: | |
177 | * RESET is not being notified to upper layers for now | |
178 | */ | |
0dc47877 | 179 | printk(KERN_INFO "%s: received a reset conf!\n", __func__); |
1da177e4 LT |
180 | break; |
181 | default: | |
182 | if (ev->cfm_prim) { | |
183 | printk(KERN_INFO "%s: received unknown %d prim!\n", | |
0dc47877 | 184 | __func__, ev->cfm_prim); |
1da177e4 LT |
185 | break; |
186 | } | |
187 | goto out_skb_put; /* No confirmation */ | |
188 | } | |
189 | out_kfree_skb: | |
190 | kfree_skb(skb); | |
191 | out_skb_put: | |
192 | kfree_skb(skb); | |
193 | return rc; | |
194 | } | |
195 | ||
196 | void llc_conn_send_pdu(struct sock *sk, struct sk_buff *skb) | |
197 | { | |
198 | /* queue PDU to send to MAC layer */ | |
199 | skb_queue_tail(&sk->sk_write_queue, skb); | |
200 | llc_conn_send_pdus(sk); | |
201 | } | |
202 | ||
203 | /** | |
204 | * llc_conn_rtn_pdu - sends received data pdu to upper layer | |
205 | * @sk: Active connection | |
206 | * @skb: Received data frame | |
207 | * | |
208 | * Sends received data pdu to upper layer (by using indicate function). | |
209 | * Prepares service parameters (prim and prim_data). calling indication | |
210 | * function will be done in llc_conn_state_process. | |
211 | */ | |
212 | void llc_conn_rtn_pdu(struct sock *sk, struct sk_buff *skb) | |
213 | { | |
214 | struct llc_conn_state_ev *ev = llc_conn_ev(skb); | |
215 | ||
216 | ev->ind_prim = LLC_DATA_PRIM; | |
217 | } | |
218 | ||
219 | /** | |
220 | * llc_conn_resend_i_pdu_as_cmd - resend all all unacknowledged I PDUs | |
221 | * @sk: active connection | |
222 | * @nr: NR | |
223 | * @first_p_bit: p_bit value of first pdu | |
224 | * | |
225 | * Resend all unacknowledged I PDUs, starting with the NR; send first as | |
226 | * command PDU with P bit equal first_p_bit; if more than one send | |
227 | * subsequent as command PDUs with P bit equal zero (0). | |
228 | */ | |
229 | void llc_conn_resend_i_pdu_as_cmd(struct sock *sk, u8 nr, u8 first_p_bit) | |
230 | { | |
231 | struct sk_buff *skb; | |
232 | struct llc_pdu_sn *pdu; | |
233 | u16 nbr_unack_pdus; | |
234 | struct llc_sock *llc; | |
235 | u8 howmany_resend = 0; | |
236 | ||
237 | llc_conn_remove_acked_pdus(sk, nr, &nbr_unack_pdus); | |
238 | if (!nbr_unack_pdus) | |
239 | goto out; | |
240 | /* | |
241 | * Process unack PDUs only if unack queue is not empty; remove | |
242 | * appropriate PDUs, fix them up, and put them on mac_pdu_q. | |
243 | */ | |
244 | llc = llc_sk(sk); | |
245 | ||
246 | while ((skb = skb_dequeue(&llc->pdu_unack_q)) != NULL) { | |
247 | pdu = llc_pdu_sn_hdr(skb); | |
248 | llc_pdu_set_cmd_rsp(skb, LLC_PDU_CMD); | |
249 | llc_pdu_set_pf_bit(skb, first_p_bit); | |
250 | skb_queue_tail(&sk->sk_write_queue, skb); | |
251 | first_p_bit = 0; | |
252 | llc->vS = LLC_I_GET_NS(pdu); | |
253 | howmany_resend++; | |
254 | } | |
255 | if (howmany_resend > 0) | |
256 | llc->vS = (llc->vS + 1) % LLC_2_SEQ_NBR_MODULO; | |
257 | /* any PDUs to re-send are queued up; start sending to MAC */ | |
258 | llc_conn_send_pdus(sk); | |
259 | out:; | |
260 | } | |
261 | ||
262 | /** | |
263 | * llc_conn_resend_i_pdu_as_rsp - Resend all unacknowledged I PDUs | |
264 | * @sk: active connection. | |
265 | * @nr: NR | |
266 | * @first_f_bit: f_bit value of first pdu. | |
267 | * | |
268 | * Resend all unacknowledged I PDUs, starting with the NR; send first as | |
269 | * response PDU with F bit equal first_f_bit; if more than one send | |
270 | * subsequent as response PDUs with F bit equal zero (0). | |
271 | */ | |
272 | void llc_conn_resend_i_pdu_as_rsp(struct sock *sk, u8 nr, u8 first_f_bit) | |
273 | { | |
274 | struct sk_buff *skb; | |
275 | u16 nbr_unack_pdus; | |
276 | struct llc_sock *llc = llc_sk(sk); | |
277 | u8 howmany_resend = 0; | |
278 | ||
279 | llc_conn_remove_acked_pdus(sk, nr, &nbr_unack_pdus); | |
280 | if (!nbr_unack_pdus) | |
281 | goto out; | |
282 | /* | |
283 | * Process unack PDUs only if unack queue is not empty; remove | |
284 | * appropriate PDUs, fix them up, and put them on mac_pdu_q | |
285 | */ | |
286 | while ((skb = skb_dequeue(&llc->pdu_unack_q)) != NULL) { | |
287 | struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb); | |
288 | ||
289 | llc_pdu_set_cmd_rsp(skb, LLC_PDU_RSP); | |
290 | llc_pdu_set_pf_bit(skb, first_f_bit); | |
291 | skb_queue_tail(&sk->sk_write_queue, skb); | |
292 | first_f_bit = 0; | |
293 | llc->vS = LLC_I_GET_NS(pdu); | |
294 | howmany_resend++; | |
295 | } | |
296 | if (howmany_resend > 0) | |
297 | llc->vS = (llc->vS + 1) % LLC_2_SEQ_NBR_MODULO; | |
298 | /* any PDUs to re-send are queued up; start sending to MAC */ | |
299 | llc_conn_send_pdus(sk); | |
300 | out:; | |
301 | } | |
302 | ||
303 | /** | |
304 | * llc_conn_remove_acked_pdus - Removes acknowledged pdus from tx queue | |
305 | * @sk: active connection | |
306 | * nr: NR | |
307 | * how_many_unacked: size of pdu_unack_q after removing acked pdus | |
308 | * | |
309 | * Removes acknowledged pdus from transmit queue (pdu_unack_q). Returns | |
310 | * the number of pdus that removed from queue. | |
311 | */ | |
312 | int llc_conn_remove_acked_pdus(struct sock *sk, u8 nr, u16 *how_many_unacked) | |
313 | { | |
314 | int pdu_pos, i; | |
315 | struct sk_buff *skb; | |
316 | struct llc_pdu_sn *pdu; | |
317 | int nbr_acked = 0; | |
318 | struct llc_sock *llc = llc_sk(sk); | |
319 | int q_len = skb_queue_len(&llc->pdu_unack_q); | |
320 | ||
321 | if (!q_len) | |
322 | goto out; | |
323 | skb = skb_peek(&llc->pdu_unack_q); | |
324 | pdu = llc_pdu_sn_hdr(skb); | |
325 | ||
326 | /* finding position of last acked pdu in queue */ | |
327 | pdu_pos = ((int)LLC_2_SEQ_NBR_MODULO + (int)nr - | |
328 | (int)LLC_I_GET_NS(pdu)) % LLC_2_SEQ_NBR_MODULO; | |
329 | ||
330 | for (i = 0; i < pdu_pos && i < q_len; i++) { | |
331 | skb = skb_dequeue(&llc->pdu_unack_q); | |
c3431ea7 | 332 | kfree_skb(skb); |
1da177e4 LT |
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; | |
9b373069 | 409 | const llc_conn_ev_qfyr_t *next_qualifier; |
1da177e4 LT |
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; | |
14b7d95f | 457 | const llc_conn_action_t *next_action; |
1da177e4 LT |
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 | ||
b76f5a84 OP |
472 | static inline bool llc_estab_match(const struct llc_sap *sap, |
473 | const struct llc_addr *daddr, | |
474 | const struct llc_addr *laddr, | |
475 | const struct sock *sk) | |
476 | { | |
477 | struct llc_sock *llc = llc_sk(sk); | |
478 | ||
479 | return llc->laddr.lsap == laddr->lsap && | |
480 | llc->daddr.lsap == daddr->lsap && | |
951fd874 JP |
481 | ether_addr_equal(llc->laddr.mac, laddr->mac) && |
482 | ether_addr_equal(llc->daddr.mac, daddr->mac); | |
b76f5a84 OP |
483 | } |
484 | ||
1da177e4 | 485 | /** |
d389424e | 486 | * __llc_lookup_established - Finds connection for the remote/local sap/mac |
1da177e4 LT |
487 | * @sap: SAP |
488 | * @daddr: address of remote LLC (MAC + SAP) | |
489 | * @laddr: address of local LLC (MAC + SAP) | |
490 | * | |
491 | * Search connection list of the SAP and finds connection using the remote | |
492 | * mac, remote sap, local mac, and local sap. Returns pointer for | |
493 | * connection found, %NULL otherwise. | |
d389424e | 494 | * Caller has to make sure local_bh is disabled. |
1da177e4 | 495 | */ |
d389424e ACM |
496 | static struct sock *__llc_lookup_established(struct llc_sap *sap, |
497 | struct llc_addr *daddr, | |
498 | struct llc_addr *laddr) | |
1da177e4 LT |
499 | { |
500 | struct sock *rc; | |
b76f5a84 | 501 | struct hlist_nulls_node *node; |
52d58aef OP |
502 | int slot = llc_sk_laddr_hashfn(sap, laddr); |
503 | struct hlist_nulls_head *laddr_hb = &sap->sk_laddr_hash[slot]; | |
b76f5a84 OP |
504 | |
505 | rcu_read_lock(); | |
506 | again: | |
52d58aef | 507 | sk_nulls_for_each_rcu(rc, node, laddr_hb) { |
b76f5a84 OP |
508 | if (llc_estab_match(sap, daddr, laddr, rc)) { |
509 | /* Extra checks required by SLAB_DESTROY_BY_RCU */ | |
510 | if (unlikely(!atomic_inc_not_zero(&rc->sk_refcnt))) | |
511 | goto again; | |
512 | if (unlikely(llc_sk(rc)->sap != sap || | |
513 | !llc_estab_match(sap, daddr, laddr, rc))) { | |
514 | sock_put(rc); | |
515 | continue; | |
516 | } | |
1da177e4 LT |
517 | goto found; |
518 | } | |
519 | } | |
520 | rc = NULL; | |
52d58aef OP |
521 | /* |
522 | * if the nulls value we got at the end of this lookup is | |
523 | * not the expected one, we must restart lookup. | |
524 | * We probably met an item that was moved to another chain. | |
525 | */ | |
526 | if (unlikely(get_nulls_value(node) != slot)) | |
527 | goto again; | |
1da177e4 | 528 | found: |
b76f5a84 | 529 | rcu_read_unlock(); |
1da177e4 LT |
530 | return rc; |
531 | } | |
532 | ||
d389424e ACM |
533 | struct sock *llc_lookup_established(struct llc_sap *sap, |
534 | struct llc_addr *daddr, | |
535 | struct llc_addr *laddr) | |
536 | { | |
537 | struct sock *sk; | |
538 | ||
539 | local_bh_disable(); | |
540 | sk = __llc_lookup_established(sap, daddr, laddr); | |
541 | local_bh_enable(); | |
542 | return sk; | |
543 | } | |
544 | ||
b76f5a84 OP |
545 | static inline bool llc_listener_match(const struct llc_sap *sap, |
546 | const struct llc_addr *laddr, | |
547 | const struct sock *sk) | |
548 | { | |
549 | struct llc_sock *llc = llc_sk(sk); | |
550 | ||
551 | return sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_LISTEN && | |
552 | llc->laddr.lsap == laddr->lsap && | |
951fd874 | 553 | ether_addr_equal(llc->laddr.mac, laddr->mac); |
b76f5a84 OP |
554 | } |
555 | ||
52d58aef OP |
556 | static struct sock *__llc_lookup_listener(struct llc_sap *sap, |
557 | struct llc_addr *laddr) | |
1da177e4 LT |
558 | { |
559 | struct sock *rc; | |
b76f5a84 | 560 | struct hlist_nulls_node *node; |
52d58aef OP |
561 | int slot = llc_sk_laddr_hashfn(sap, laddr); |
562 | struct hlist_nulls_head *laddr_hb = &sap->sk_laddr_hash[slot]; | |
b76f5a84 OP |
563 | |
564 | rcu_read_lock(); | |
565 | again: | |
52d58aef | 566 | sk_nulls_for_each_rcu(rc, node, laddr_hb) { |
b76f5a84 OP |
567 | if (llc_listener_match(sap, laddr, rc)) { |
568 | /* Extra checks required by SLAB_DESTROY_BY_RCU */ | |
569 | if (unlikely(!atomic_inc_not_zero(&rc->sk_refcnt))) | |
570 | goto again; | |
571 | if (unlikely(llc_sk(rc)->sap != sap || | |
572 | !llc_listener_match(sap, laddr, rc))) { | |
573 | sock_put(rc); | |
574 | continue; | |
575 | } | |
1da177e4 LT |
576 | goto found; |
577 | } | |
578 | } | |
579 | rc = NULL; | |
52d58aef OP |
580 | /* |
581 | * if the nulls value we got at the end of this lookup is | |
582 | * not the expected one, we must restart lookup. | |
583 | * We probably met an item that was moved to another chain. | |
584 | */ | |
585 | if (unlikely(get_nulls_value(node) != slot)) | |
586 | goto again; | |
1da177e4 | 587 | found: |
b76f5a84 | 588 | rcu_read_unlock(); |
1da177e4 LT |
589 | return rc; |
590 | } | |
591 | ||
52d58aef OP |
592 | /** |
593 | * llc_lookup_listener - Finds listener for local MAC + SAP | |
594 | * @sap: SAP | |
595 | * @laddr: address of local LLC (MAC + SAP) | |
596 | * | |
597 | * Search connection list of the SAP and finds connection listening on | |
598 | * local mac, and local sap. Returns pointer for parent socket found, | |
599 | * %NULL otherwise. | |
600 | * Caller has to make sure local_bh is disabled. | |
601 | */ | |
602 | static struct sock *llc_lookup_listener(struct llc_sap *sap, | |
603 | struct llc_addr *laddr) | |
604 | { | |
605 | static struct llc_addr null_addr; | |
606 | struct sock *rc = __llc_lookup_listener(sap, laddr); | |
607 | ||
608 | if (!rc) | |
609 | rc = __llc_lookup_listener(sap, &null_addr); | |
610 | ||
611 | return rc; | |
612 | } | |
613 | ||
d389424e ACM |
614 | static struct sock *__llc_lookup(struct llc_sap *sap, |
615 | struct llc_addr *daddr, | |
616 | struct llc_addr *laddr) | |
617 | { | |
618 | struct sock *sk = __llc_lookup_established(sap, daddr, laddr); | |
619 | ||
620 | return sk ? : llc_lookup_listener(sap, laddr); | |
621 | } | |
622 | ||
1da177e4 LT |
623 | /** |
624 | * llc_data_accept_state - designates if in this state data can be sent. | |
625 | * @state: state of connection. | |
626 | * | |
627 | * Returns 0 if data can be sent, 1 otherwise. | |
628 | */ | |
629 | u8 llc_data_accept_state(u8 state) | |
630 | { | |
631 | return state != LLC_CONN_STATE_NORMAL && state != LLC_CONN_STATE_BUSY && | |
632 | state != LLC_CONN_STATE_REJ; | |
633 | } | |
634 | ||
635 | /** | |
0eb80172 | 636 | * llc_find_next_offset - finds offset for next category of transitions |
1da177e4 LT |
637 | * @state: state table. |
638 | * @offset: start offset. | |
639 | * | |
640 | * Finds offset of next category of transitions in transition table. | |
641 | * Returns the start index of next category. | |
642 | */ | |
0eb80172 | 643 | static u16 __init llc_find_next_offset(struct llc_conn_state *state, u16 offset) |
1da177e4 LT |
644 | { |
645 | u16 cnt = 0; | |
646 | struct llc_conn_state_trans **next_trans; | |
647 | ||
648 | for (next_trans = state->transitions + offset; | |
649 | (*next_trans)->ev; next_trans++) | |
650 | ++cnt; | |
651 | return cnt; | |
652 | } | |
653 | ||
654 | /** | |
655 | * llc_build_offset_table - builds offset table of connection | |
656 | * | |
657 | * Fills offset table of connection state transition table | |
658 | * (llc_offset_table). | |
659 | */ | |
660 | void __init llc_build_offset_table(void) | |
661 | { | |
662 | struct llc_conn_state *curr_state; | |
663 | int state, ev_type, next_offset; | |
664 | ||
665 | for (state = 0; state < NBR_CONN_STATES; state++) { | |
666 | curr_state = &llc_conn_state_table[state]; | |
667 | next_offset = 0; | |
668 | for (ev_type = 0; ev_type < NBR_CONN_EV; ev_type++) { | |
669 | llc_offset_table[state][ev_type] = next_offset; | |
0eb80172 ACM |
670 | next_offset += llc_find_next_offset(curr_state, |
671 | next_offset) + 1; | |
1da177e4 LT |
672 | } |
673 | } | |
674 | } | |
675 | ||
676 | /** | |
677 | * llc_find_offset - finds start offset of category of transitions | |
678 | * @state: state of connection | |
679 | * @ev_type: type of happened event | |
680 | * | |
681 | * Finds start offset of desired category of transitions. Returns the | |
682 | * desired start offset. | |
683 | */ | |
684 | static int llc_find_offset(int state, int ev_type) | |
685 | { | |
686 | int rc = 0; | |
687 | /* at this stage, llc_offset_table[..][2] is not important. it is for | |
688 | * init_pf_cycle and I don't know what is it. | |
689 | */ | |
690 | switch (ev_type) { | |
691 | case LLC_CONN_EV_TYPE_PRIM: | |
692 | rc = llc_offset_table[state][0]; break; | |
693 | case LLC_CONN_EV_TYPE_PDU: | |
694 | rc = llc_offset_table[state][4]; break; | |
695 | case LLC_CONN_EV_TYPE_SIMPLE: | |
696 | rc = llc_offset_table[state][1]; break; | |
697 | case LLC_CONN_EV_TYPE_P_TMR: | |
698 | case LLC_CONN_EV_TYPE_ACK_TMR: | |
699 | case LLC_CONN_EV_TYPE_REJ_TMR: | |
700 | case LLC_CONN_EV_TYPE_BUSY_TMR: | |
701 | rc = llc_offset_table[state][3]; break; | |
702 | } | |
703 | return rc; | |
704 | } | |
705 | ||
706 | /** | |
707 | * llc_sap_add_socket - adds a socket to a SAP | |
708 | * @sap: SAP | |
709 | * @sk: socket | |
710 | * | |
52d58aef | 711 | * This function adds a socket to the hash tables of a SAP. |
1da177e4 LT |
712 | */ |
713 | void llc_sap_add_socket(struct llc_sap *sap, struct sock *sk) | |
714 | { | |
6d2e3ea2 OP |
715 | struct llc_sock *llc = llc_sk(sk); |
716 | struct hlist_head *dev_hb = llc_sk_dev_hash(sap, llc->dev->ifindex); | |
52d58aef | 717 | struct hlist_nulls_head *laddr_hb = llc_sk_laddr_hash(sap, &llc->laddr); |
6d2e3ea2 | 718 | |
6e2144b7 | 719 | llc_sap_hold(sap); |
1da177e4 | 720 | llc_sk(sk)->sap = sap; |
6d2e3ea2 OP |
721 | |
722 | spin_lock_bh(&sap->sk_lock); | |
52d58aef OP |
723 | sap->sk_count++; |
724 | sk_nulls_add_node_rcu(sk, laddr_hb); | |
6d2e3ea2 | 725 | hlist_add_head(&llc->dev_hash_node, dev_hb); |
b76f5a84 | 726 | spin_unlock_bh(&sap->sk_lock); |
1da177e4 LT |
727 | } |
728 | ||
729 | /** | |
730 | * llc_sap_remove_socket - removes a socket from SAP | |
731 | * @sap: SAP | |
732 | * @sk: socket | |
733 | * | |
52d58aef | 734 | * This function removes a connection from the hash tables of a SAP if |
1da177e4 LT |
735 | * the connection was in this list. |
736 | */ | |
737 | void llc_sap_remove_socket(struct llc_sap *sap, struct sock *sk) | |
738 | { | |
6d2e3ea2 OP |
739 | struct llc_sock *llc = llc_sk(sk); |
740 | ||
b76f5a84 OP |
741 | spin_lock_bh(&sap->sk_lock); |
742 | sk_nulls_del_node_init_rcu(sk); | |
6d2e3ea2 | 743 | hlist_del(&llc->dev_hash_node); |
52d58aef | 744 | sap->sk_count--; |
b76f5a84 | 745 | spin_unlock_bh(&sap->sk_lock); |
6e2144b7 | 746 | llc_sap_put(sap); |
1da177e4 LT |
747 | } |
748 | ||
749 | /** | |
750 | * llc_conn_rcv - sends received pdus to the connection state machine | |
751 | * @sk: current connection structure. | |
752 | * @skb: received frame. | |
753 | * | |
754 | * Sends received pdus to the connection state machine. | |
755 | */ | |
3cdba604 | 756 | static int llc_conn_rcv(struct sock *sk, struct sk_buff *skb) |
1da177e4 LT |
757 | { |
758 | struct llc_conn_state_ev *ev = llc_conn_ev(skb); | |
1da177e4 | 759 | |
1da177e4 LT |
760 | ev->type = LLC_CONN_EV_TYPE_PDU; |
761 | ev->reason = 0; | |
762 | return llc_conn_state_process(sk, skb); | |
763 | } | |
764 | ||
d389424e ACM |
765 | static struct sock *llc_create_incoming_sock(struct sock *sk, |
766 | struct net_device *dev, | |
767 | struct llc_addr *saddr, | |
768 | struct llc_addr *daddr) | |
769 | { | |
3b1e0a65 | 770 | struct sock *newsk = llc_sk_alloc(sock_net(sk), sk->sk_family, GFP_ATOMIC, |
11aa9c28 | 771 | sk->sk_prot, 0); |
d389424e ACM |
772 | struct llc_sock *newllc, *llc = llc_sk(sk); |
773 | ||
774 | if (!newsk) | |
775 | goto out; | |
776 | newllc = llc_sk(newsk); | |
777 | memcpy(&newllc->laddr, daddr, sizeof(newllc->laddr)); | |
778 | memcpy(&newllc->daddr, saddr, sizeof(newllc->daddr)); | |
779 | newllc->dev = dev; | |
780 | dev_hold(dev); | |
781 | llc_sap_add_socket(llc->sap, newsk); | |
782 | llc_sap_hold(llc->sap); | |
783 | out: | |
784 | return newsk; | |
785 | } | |
786 | ||
1da177e4 LT |
787 | void llc_conn_handler(struct llc_sap *sap, struct sk_buff *skb) |
788 | { | |
789 | struct llc_addr saddr, daddr; | |
790 | struct sock *sk; | |
791 | ||
792 | llc_pdu_decode_sa(skb, saddr.mac); | |
793 | llc_pdu_decode_ssap(skb, &saddr.lsap); | |
794 | llc_pdu_decode_da(skb, daddr.mac); | |
795 | llc_pdu_decode_dsap(skb, &daddr.lsap); | |
796 | ||
d389424e ACM |
797 | sk = __llc_lookup(sap, &saddr, &daddr); |
798 | if (!sk) | |
799 | goto drop; | |
800 | ||
801 | bh_lock_sock(sk); | |
802 | /* | |
803 | * This has to be done here and not at the upper layer ->accept | |
804 | * method because of the way the PROCOM state machine works: | |
805 | * it needs to set several state variables (see, for instance, | |
806 | * llc_adm_actions_2 in net/llc/llc_c_st.c) and send a packet to | |
807 | * the originator of the new connection, and this state has to be | |
808 | * in the newly created struct sock private area. -acme | |
809 | */ | |
810 | if (unlikely(sk->sk_state == TCP_LISTEN)) { | |
811 | struct sock *newsk = llc_create_incoming_sock(sk, skb->dev, | |
812 | &saddr, &daddr); | |
813 | if (!newsk) | |
814 | goto drop_unlock; | |
815 | skb_set_owner_r(skb, newsk); | |
816 | } else { | |
1da177e4 | 817 | /* |
d389424e ACM |
818 | * Can't be skb_set_owner_r, this will be done at the |
819 | * llc_conn_state_process function, later on, when we will use | |
820 | * skb_queue_rcv_skb to send it to upper layers, this is | |
821 | * another trick required to cope with how the PROCOM state | |
822 | * machine works. -acme | |
1da177e4 | 823 | */ |
2b3eb433 ED |
824 | skb_orphan(skb); |
825 | sock_hold(sk); | |
d389424e | 826 | skb->sk = sk; |
2b3eb433 | 827 | skb->destructor = sock_efree; |
04e4223f | 828 | } |
1da177e4 LT |
829 | if (!sock_owned_by_user(sk)) |
830 | llc_conn_rcv(sk, skb); | |
831 | else { | |
0dc47877 | 832 | dprintk("%s: adding to backlog...\n", __func__); |
1da177e4 | 833 | llc_set_backlog_type(skb, LLC_PACKET); |
f545a38f | 834 | if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) |
79545b68 | 835 | goto drop_unlock; |
1da177e4 | 836 | } |
d389424e | 837 | out: |
1da177e4 LT |
838 | bh_unlock_sock(sk); |
839 | sock_put(sk); | |
840 | return; | |
841 | drop: | |
842 | kfree_skb(skb); | |
d389424e ACM |
843 | return; |
844 | drop_unlock: | |
845 | kfree_skb(skb); | |
846 | goto out; | |
1da177e4 LT |
847 | } |
848 | ||
849 | #undef LLC_REFCNT_DEBUG | |
850 | #ifdef LLC_REFCNT_DEBUG | |
851 | static atomic_t llc_sock_nr; | |
852 | #endif | |
853 | ||
1da177e4 LT |
854 | /** |
855 | * llc_backlog_rcv - Processes rx frames and expired timers. | |
856 | * @sk: LLC sock (p8022 connection) | |
857 | * @skb: queued rx frame or event | |
858 | * | |
859 | * This function processes frames that has received and timers that has | |
860 | * expired during sending an I pdu (refer to data_req_handler). frames | |
861 | * queue by llc_rcv function (llc_mac.c) and timers queue by timer | |
862 | * callback functions(llc_c_ac.c). | |
863 | */ | |
864 | static int llc_backlog_rcv(struct sock *sk, struct sk_buff *skb) | |
865 | { | |
866 | int rc = 0; | |
867 | struct llc_sock *llc = llc_sk(sk); | |
868 | ||
af426d32 ACM |
869 | if (likely(llc_backlog_type(skb) == LLC_PACKET)) { |
870 | if (likely(llc->state > 1)) /* not closed */ | |
1da177e4 LT |
871 | rc = llc_conn_rcv(sk, skb); |
872 | else | |
873 | goto out_kfree_skb; | |
874 | } else if (llc_backlog_type(skb) == LLC_EVENT) { | |
875 | /* timer expiration event */ | |
af426d32 | 876 | if (likely(llc->state > 1)) /* not closed */ |
1da177e4 LT |
877 | rc = llc_conn_state_process(sk, skb); |
878 | else | |
879 | goto out_kfree_skb; | |
880 | } else { | |
0dc47877 | 881 | printk(KERN_ERR "%s: invalid skb in backlog\n", __func__); |
1da177e4 LT |
882 | goto out_kfree_skb; |
883 | } | |
884 | out: | |
885 | return rc; | |
886 | out_kfree_skb: | |
887 | kfree_skb(skb); | |
888 | goto out; | |
889 | } | |
890 | ||
891 | /** | |
892 | * llc_sk_init - Initializes a socket with default llc values. | |
893 | * @sk: socket to initialize. | |
894 | * | |
895 | * Initializes a socket with default llc values. | |
896 | */ | |
3cdba604 | 897 | static void llc_sk_init(struct sock *sk) |
1da177e4 LT |
898 | { |
899 | struct llc_sock *llc = llc_sk(sk); | |
900 | ||
901 | llc->state = LLC_CONN_STATE_ADM; | |
902 | llc->inc_cntr = llc->dec_cntr = 2; | |
903 | llc->dec_step = llc->connect_step = 1; | |
904 | ||
b24b8a24 PE |
905 | setup_timer(&llc->ack_timer.timer, llc_conn_ack_tmr_cb, |
906 | (unsigned long)sk); | |
590232a7 | 907 | llc->ack_timer.expire = sysctl_llc2_ack_timeout; |
1da177e4 | 908 | |
b24b8a24 PE |
909 | setup_timer(&llc->pf_cycle_timer.timer, llc_conn_pf_cycle_tmr_cb, |
910 | (unsigned long)sk); | |
590232a7 | 911 | llc->pf_cycle_timer.expire = sysctl_llc2_p_timeout; |
1da177e4 | 912 | |
b24b8a24 PE |
913 | setup_timer(&llc->rej_sent_timer.timer, llc_conn_rej_tmr_cb, |
914 | (unsigned long)sk); | |
590232a7 | 915 | llc->rej_sent_timer.expire = sysctl_llc2_rej_timeout; |
1da177e4 | 916 | |
b24b8a24 PE |
917 | setup_timer(&llc->busy_state_timer.timer, llc_conn_busy_tmr_cb, |
918 | (unsigned long)sk); | |
590232a7 | 919 | llc->busy_state_timer.expire = sysctl_llc2_busy_timeout; |
1da177e4 LT |
920 | |
921 | llc->n2 = 2; /* max retransmit */ | |
922 | llc->k = 2; /* tx win size, will adjust dynam */ | |
923 | llc->rw = 128; /* rx win size (opt and equal to | |
d57b1869 | 924 | * tx_win of remote LLC) */ |
1da177e4 LT |
925 | skb_queue_head_init(&llc->pdu_unack_q); |
926 | sk->sk_backlog_rcv = llc_backlog_rcv; | |
927 | } | |
928 | ||
929 | /** | |
930 | * llc_sk_alloc - Allocates LLC sock | |
931 | * @family: upper layer protocol family | |
932 | * @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc) | |
933 | * | |
934 | * Allocates a LLC sock and initializes it. Returns the new LLC sock | |
935 | * or %NULL if there's no memory available for one | |
936 | */ | |
11aa9c28 | 937 | struct sock *llc_sk_alloc(struct net *net, int family, gfp_t priority, struct proto *prot, int kern) |
1da177e4 | 938 | { |
11aa9c28 | 939 | struct sock *sk = sk_alloc(net, family, priority, prot, kern); |
1da177e4 LT |
940 | |
941 | if (!sk) | |
942 | goto out; | |
943 | llc_sk_init(sk); | |
944 | sock_init_data(NULL, sk); | |
945 | #ifdef LLC_REFCNT_DEBUG | |
946 | atomic_inc(&llc_sock_nr); | |
947 | printk(KERN_DEBUG "LLC socket %p created in %s, now we have %d alive\n", sk, | |
0dc47877 | 948 | __func__, atomic_read(&llc_sock_nr)); |
1da177e4 LT |
949 | #endif |
950 | out: | |
951 | return sk; | |
952 | } | |
953 | ||
954 | /** | |
955 | * llc_sk_free - Frees a LLC socket | |
956 | * @sk - socket to free | |
957 | * | |
958 | * Frees a LLC socket | |
959 | */ | |
960 | void llc_sk_free(struct sock *sk) | |
961 | { | |
962 | struct llc_sock *llc = llc_sk(sk); | |
963 | ||
964 | llc->state = LLC_CONN_OUT_OF_SVC; | |
965 | /* Stop all (possibly) running timers */ | |
966 | llc_conn_ac_stop_all_timers(sk, NULL); | |
967 | #ifdef DEBUG_LLC_CONN_ALLOC | |
0dc47877 | 968 | printk(KERN_INFO "%s: unackq=%d, txq=%d\n", __func__, |
1da177e4 LT |
969 | skb_queue_len(&llc->pdu_unack_q), |
970 | skb_queue_len(&sk->sk_write_queue)); | |
971 | #endif | |
972 | skb_queue_purge(&sk->sk_receive_queue); | |
973 | skb_queue_purge(&sk->sk_write_queue); | |
974 | skb_queue_purge(&llc->pdu_unack_q); | |
975 | #ifdef LLC_REFCNT_DEBUG | |
976 | if (atomic_read(&sk->sk_refcnt) != 1) { | |
977 | printk(KERN_DEBUG "Destruction of LLC sock %p delayed in %s, cnt=%d\n", | |
0dc47877 | 978 | sk, __func__, atomic_read(&sk->sk_refcnt)); |
1da177e4 LT |
979 | printk(KERN_DEBUG "%d LLC sockets are still alive\n", |
980 | atomic_read(&llc_sock_nr)); | |
981 | } else { | |
982 | atomic_dec(&llc_sock_nr); | |
983 | printk(KERN_DEBUG "LLC socket %p released in %s, %d are still alive\n", sk, | |
0dc47877 | 984 | __func__, atomic_read(&llc_sock_nr)); |
1da177e4 LT |
985 | } |
986 | #endif | |
987 | sock_put(sk); | |
988 | } | |
989 | ||
990 | /** | |
991 | * llc_sk_reset - resets a connection | |
992 | * @sk: LLC socket to reset | |
993 | * | |
994 | * Resets a connection to the out of service state. Stops its timers | |
995 | * and frees any frames in the queues of the connection. | |
996 | */ | |
997 | void llc_sk_reset(struct sock *sk) | |
998 | { | |
999 | struct llc_sock *llc = llc_sk(sk); | |
1000 | ||
1001 | llc_conn_ac_stop_all_timers(sk, NULL); | |
1002 | skb_queue_purge(&sk->sk_write_queue); | |
1003 | skb_queue_purge(&llc->pdu_unack_q); | |
1004 | llc->remote_busy_flag = 0; | |
1005 | llc->cause_flag = 0; | |
1006 | llc->retry_count = 0; | |
1007 | llc_conn_set_p_flag(sk, 0); | |
1008 | llc->f_flag = 0; | |
1009 | llc->s_flag = 0; | |
1010 | llc->ack_pf = 0; | |
1011 | llc->first_pdu_Ns = 0; | |
1012 | llc->ack_must_be_send = 0; | |
1013 | llc->dec_step = 1; | |
1014 | llc->inc_cntr = 2; | |
1015 | llc->dec_cntr = 2; | |
1016 | llc->X = 0; | |
1017 | llc->failed_data_req = 0 ; | |
1018 | llc->last_nr = 0; | |
1019 | } |