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[IA64] arch/ia64/sn/kernel/mca.c: undo lock when sn_oemdata can't be extended
[wrt350n-kernel.git] / net / dccp / input.c
blob1ce101062824ef25fca9280889a572ae2c62408b
1 /*
2 * net/dccp/input.c
3 *
4 * An implementation of the DCCP protocol
5 * Arnaldo Carvalho de Melo <acme@conectiva.com.br>
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 */
12
13 #include <linux/dccp.h>
14 #include <linux/skbuff.h>
15
16 #include <net/sock.h>
17
18 #include "ackvec.h"
19 #include "ccid.h"
20 #include "dccp.h"
21
22 /* rate-limit for syncs in reply to sequence-invalid packets; RFC 4340, 7.5.4 */
23 int sysctl_dccp_sync_ratelimit __read_mostly = HZ / 8;
24
25 static void dccp_fin(struct sock *sk, struct sk_buff *skb)
26 {
27 sk->sk_shutdown |= RCV_SHUTDOWN;
28 sock_set_flag(sk, SOCK_DONE);
29 __skb_pull(skb, dccp_hdr(skb)->dccph_doff * 4);
30 __skb_queue_tail(&sk->sk_receive_queue, skb);
31 skb_set_owner_r(skb, sk);
32 sk->sk_data_ready(sk, 0);
33 }
34
35 static void dccp_rcv_close(struct sock *sk, struct sk_buff *skb)
36 {
37 dccp_send_reset(sk, DCCP_RESET_CODE_CLOSED);
38 dccp_fin(sk, skb);
39 dccp_set_state(sk, DCCP_CLOSED);
40 sk_wake_async(sk, 1, POLL_HUP);
41 }
42
43 static void dccp_rcv_closereq(struct sock *sk, struct sk_buff *skb)
44 {
45 /*
46 * Step 7: Check for unexpected packet types
47 * If (S.is_server and P.type == CloseReq)
48 * Send Sync packet acknowledging P.seqno
49 * Drop packet and return
50 */
51 if (dccp_sk(sk)->dccps_role != DCCP_ROLE_CLIENT) {
52 dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq, DCCP_PKT_SYNC);
53 return;
54 }
55
56 if (sk->sk_state != DCCP_CLOSING)
57 dccp_set_state(sk, DCCP_CLOSING);
58 dccp_send_close(sk, 0);
59 }
60
61 static u8 dccp_reset_code_convert(const u8 code)
62 {
63 const u8 error_code[] = {
64 [DCCP_RESET_CODE_CLOSED] = 0, /* normal termination */
65 [DCCP_RESET_CODE_UNSPECIFIED] = 0, /* nothing known */
66 [DCCP_RESET_CODE_ABORTED] = ECONNRESET,
67
68 [DCCP_RESET_CODE_NO_CONNECTION] = ECONNREFUSED,
69 [DCCP_RESET_CODE_CONNECTION_REFUSED] = ECONNREFUSED,
70 [DCCP_RESET_CODE_TOO_BUSY] = EUSERS,
71 [DCCP_RESET_CODE_AGGRESSION_PENALTY] = EDQUOT,
72
73 [DCCP_RESET_CODE_PACKET_ERROR] = ENOMSG,
74 [DCCP_RESET_CODE_BAD_INIT_COOKIE] = EBADR,
75 [DCCP_RESET_CODE_BAD_SERVICE_CODE] = EBADRQC,
76 [DCCP_RESET_CODE_OPTION_ERROR] = EILSEQ,
77 [DCCP_RESET_CODE_MANDATORY_ERROR] = EOPNOTSUPP,
78 };
79
80 return code >= DCCP_MAX_RESET_CODES ? 0 : error_code[code];
81 }
82
83 static void dccp_rcv_reset(struct sock *sk, struct sk_buff *skb)
84 {
85 u8 err = dccp_reset_code_convert(dccp_hdr_reset(skb)->dccph_reset_code);
86
87 sk->sk_err = err;
88
89 /* Queue the equivalent of TCP fin so that dccp_recvmsg exits the loop */
90 dccp_fin(sk, skb);
91
92 if (err && !sock_flag(sk, SOCK_DEAD))
93 sk_wake_async(sk, 0, POLL_ERR);
94 dccp_time_wait(sk, DCCP_TIME_WAIT, 0);
95 }
96
97 static void dccp_event_ack_recv(struct sock *sk, struct sk_buff *skb)
98 {
99 struct dccp_sock *dp = dccp_sk(sk);
100
101 if (dccp_msk(sk)->dccpms_send_ack_vector)
102 dccp_ackvec_check_rcv_ackno(dp->dccps_hc_rx_ackvec, sk,
103 DCCP_SKB_CB(skb)->dccpd_ack_seq);
104 }
105
106 static int dccp_check_seqno(struct sock *sk, struct sk_buff *skb)
107 {
108 const struct dccp_hdr *dh = dccp_hdr(skb);
109 struct dccp_sock *dp = dccp_sk(sk);
110 u64 lswl, lawl, seqno = DCCP_SKB_CB(skb)->dccpd_seq,
111 ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq;
112
113 /*
114 * Step 5: Prepare sequence numbers for Sync
115 * If P.type == Sync or P.type == SyncAck,
116 * If S.AWL <= P.ackno <= S.AWH and P.seqno >= S.SWL,
117 * / * P is valid, so update sequence number variables
118 * accordingly. After this update, P will pass the tests
119 * in Step 6. A SyncAck is generated if necessary in
120 * Step 15 * /
121 * Update S.GSR, S.SWL, S.SWH
122 * Otherwise,
123 * Drop packet and return
124 */
125 if (dh->dccph_type == DCCP_PKT_SYNC ||
126 dh->dccph_type == DCCP_PKT_SYNCACK) {
127 if (between48(ackno, dp->dccps_awl, dp->dccps_awh) &&
128 dccp_delta_seqno(dp->dccps_swl, seqno) >= 0)
129 dccp_update_gsr(sk, seqno);
130 else
131 return -1;
132 }
133
134 /*
135 * Step 6: Check sequence numbers
136 * Let LSWL = S.SWL and LAWL = S.AWL
137 * If P.type == CloseReq or P.type == Close or P.type == Reset,
138 * LSWL := S.GSR + 1, LAWL := S.GAR
139 * If LSWL <= P.seqno <= S.SWH
140 * and (P.ackno does not exist or LAWL <= P.ackno <= S.AWH),
141 * Update S.GSR, S.SWL, S.SWH
142 * If P.type != Sync,
143 * Update S.GAR
144 */
145 lswl = dp->dccps_swl;
146 lawl = dp->dccps_awl;
147
148 if (dh->dccph_type == DCCP_PKT_CLOSEREQ ||
149 dh->dccph_type == DCCP_PKT_CLOSE ||
150 dh->dccph_type == DCCP_PKT_RESET) {
151 lswl = ADD48(dp->dccps_gsr, 1);
152 lawl = dp->dccps_gar;
153 }
154
155 if (between48(seqno, lswl, dp->dccps_swh) &&
156 (ackno == DCCP_PKT_WITHOUT_ACK_SEQ ||
157 between48(ackno, lawl, dp->dccps_awh))) {
158 dccp_update_gsr(sk, seqno);
159
160 if (dh->dccph_type != DCCP_PKT_SYNC &&
161 (ackno != DCCP_PKT_WITHOUT_ACK_SEQ))
162 dp->dccps_gar = ackno;
163 } else {
164 unsigned long now = jiffies;
165 /*
166 * Step 6: Check sequence numbers
167 * Otherwise,
168 * If P.type == Reset,
169 * Send Sync packet acknowledging S.GSR
170 * Otherwise,
171 * Send Sync packet acknowledging P.seqno
172 * Drop packet and return
173 *
174 * These Syncs are rate-limited as per RFC 4340, 7.5.4:
175 * at most 1 / (dccp_sync_rate_limit * HZ) Syncs per second.
176 */
177 if (time_before(now, (dp->dccps_rate_last +
178 sysctl_dccp_sync_ratelimit)))
179 return 0;
180
181 DCCP_WARN("DCCP: Step 6 failed for %s packet, "
182 "(LSWL(%llu) <= P.seqno(%llu) <= S.SWH(%llu)) and "
183 "(P.ackno %s or LAWL(%llu) <= P.ackno(%llu) <= S.AWH(%llu), "
184 "sending SYNC...\n", dccp_packet_name(dh->dccph_type),
185 (unsigned long long) lswl, (unsigned long long) seqno,
186 (unsigned long long) dp->dccps_swh,
187 (ackno == DCCP_PKT_WITHOUT_ACK_SEQ) ? "doesn't exist"
188 : "exists",
189 (unsigned long long) lawl, (unsigned long long) ackno,
190 (unsigned long long) dp->dccps_awh);
191
192 dp->dccps_rate_last = now;
193
194 if (dh->dccph_type == DCCP_PKT_RESET)
195 seqno = dp->dccps_gsr;
196 dccp_send_sync(sk, seqno, DCCP_PKT_SYNC);
197 return -1;
198 }
199
200 return 0;
201 }
202
203 static int __dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
204 const struct dccp_hdr *dh, const unsigned len)
205 {
206 struct dccp_sock *dp = dccp_sk(sk);
207
208 switch (dccp_hdr(skb)->dccph_type) {
209 case DCCP_PKT_DATAACK:
210 case DCCP_PKT_DATA:
211 /*
212 * FIXME: check if sk_receive_queue is full, schedule DATA_DROPPED
213 * option if it is.
214 */
215 __skb_pull(skb, dh->dccph_doff * 4);
216 __skb_queue_tail(&sk->sk_receive_queue, skb);
217 skb_set_owner_r(skb, sk);
218 sk->sk_data_ready(sk, 0);
219 return 0;
220 case DCCP_PKT_ACK:
221 goto discard;
222 case DCCP_PKT_RESET:
223 /*
224 * Step 9: Process Reset
225 * If P.type == Reset,
226 * Tear down connection
227 * S.state := TIMEWAIT
228 * Set TIMEWAIT timer
229 * Drop packet and return
230 */
231 dccp_rcv_reset(sk, skb);
232 return 0;
233 case DCCP_PKT_CLOSEREQ:
234 dccp_rcv_closereq(sk, skb);
235 goto discard;
236 case DCCP_PKT_CLOSE:
237 dccp_rcv_close(sk, skb);
238 return 0;
239 case DCCP_PKT_REQUEST:
240 /* Step 7
241 * or (S.is_server and P.type == Response)
242 * or (S.is_client and P.type == Request)
243 * or (S.state >= OPEN and P.type == Request
244 * and P.seqno >= S.OSR)
245 * or (S.state >= OPEN and P.type == Response
246 * and P.seqno >= S.OSR)
247 * or (S.state == RESPOND and P.type == Data),
248 * Send Sync packet acknowledging P.seqno
249 * Drop packet and return
250 */
251 if (dp->dccps_role != DCCP_ROLE_LISTEN)
252 goto send_sync;
253 goto check_seq;
254 case DCCP_PKT_RESPONSE:
255 if (dp->dccps_role != DCCP_ROLE_CLIENT)
256 goto send_sync;
257 check_seq:
258 if (dccp_delta_seqno(dp->dccps_osr,
259 DCCP_SKB_CB(skb)->dccpd_seq) >= 0) {
260 send_sync:
261 dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq,
262 DCCP_PKT_SYNC);
263 }
264 break;
265 case DCCP_PKT_SYNC:
266 dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq,
267 DCCP_PKT_SYNCACK);
268 /*
269 * From RFC 4340, sec. 5.7
270 *
271 * As with DCCP-Ack packets, DCCP-Sync and DCCP-SyncAck packets
272 * MAY have non-zero-length application data areas, whose
273 * contents receivers MUST ignore.
274 */
275 goto discard;
276 }
277
278 DCCP_INC_STATS_BH(DCCP_MIB_INERRS);
279 discard:
280 __kfree_skb(skb);
281 return 0;
282 }
283
284 int dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
285 const struct dccp_hdr *dh, const unsigned len)
286 {
287 struct dccp_sock *dp = dccp_sk(sk);
288
289 if (dccp_check_seqno(sk, skb))
290 goto discard;
291
292 if (dccp_parse_options(sk, skb))
293 goto discard;
294
295 if (DCCP_SKB_CB(skb)->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ)
296 dccp_event_ack_recv(sk, skb);
297
298 if (dccp_msk(sk)->dccpms_send_ack_vector &&
299 dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk,
300 DCCP_SKB_CB(skb)->dccpd_seq,
301 DCCP_ACKVEC_STATE_RECEIVED))
302 goto discard;
303
304 ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb);
305 ccid_hc_tx_packet_recv(dp->dccps_hc_tx_ccid, sk, skb);
306
307 return __dccp_rcv_established(sk, skb, dh, len);
308 discard:
309 __kfree_skb(skb);
310 return 0;
311 }
312
313 EXPORT_SYMBOL_GPL(dccp_rcv_established);
314
315 static int dccp_rcv_request_sent_state_process(struct sock *sk,
316 struct sk_buff *skb,
317 const struct dccp_hdr *dh,
318 const unsigned len)
319 {
320 /*
321 * Step 4: Prepare sequence numbers in REQUEST
322 * If S.state == REQUEST,
323 * If (P.type == Response or P.type == Reset)
324 * and S.AWL <= P.ackno <= S.AWH,
325 * / * Set sequence number variables corresponding to the
326 * other endpoint, so P will pass the tests in Step 6 * /
327 * Set S.GSR, S.ISR, S.SWL, S.SWH
328 * / * Response processing continues in Step 10; Reset
329 * processing continues in Step 9 * /
330 */
331 if (dh->dccph_type == DCCP_PKT_RESPONSE) {
332 const struct inet_connection_sock *icsk = inet_csk(sk);
333 struct dccp_sock *dp = dccp_sk(sk);
334 long tstamp = dccp_timestamp();
335
336 /* Stop the REQUEST timer */
337 inet_csk_clear_xmit_timer(sk, ICSK_TIME_RETRANS);
338 BUG_TRAP(sk->sk_send_head != NULL);
339 __kfree_skb(sk->sk_send_head);
340 sk->sk_send_head = NULL;
341
342 if (!between48(DCCP_SKB_CB(skb)->dccpd_ack_seq,
343 dp->dccps_awl, dp->dccps_awh)) {
344 dccp_pr_debug("invalid ackno: S.AWL=%llu, "
345 "P.ackno=%llu, S.AWH=%llu \n",
346 (unsigned long long)dp->dccps_awl,
347 (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq,
348 (unsigned long long)dp->dccps_awh);
349 goto out_invalid_packet;
350 }
351
352 if (dccp_parse_options(sk, skb))
353 goto out_invalid_packet;
354
355 /* Obtain usec RTT sample from SYN exchange (used by CCID 3) */
356 if (likely(dp->dccps_options_received.dccpor_timestamp_echo))
357 dp->dccps_syn_rtt = dccp_sample_rtt(sk, 10 * (tstamp -
358 dp->dccps_options_received.dccpor_timestamp_echo));
359
360 if (dccp_msk(sk)->dccpms_send_ack_vector &&
361 dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk,
362 DCCP_SKB_CB(skb)->dccpd_seq,
363 DCCP_ACKVEC_STATE_RECEIVED))
364 goto out_invalid_packet; /* FIXME: change error code */
365
366 dp->dccps_isr = DCCP_SKB_CB(skb)->dccpd_seq;
367 dccp_update_gsr(sk, dp->dccps_isr);
368 /*
369 * SWL and AWL are initially adjusted so that they are not less than
370 * the initial Sequence Numbers received and sent, respectively:
371 * SWL := max(GSR + 1 - floor(W/4), ISR),
372 * AWL := max(GSS - W' + 1, ISS).
373 * These adjustments MUST be applied only at the beginning of the
374 * connection.
375 *
376 * AWL was adjusted in dccp_v4_connect -acme
377 */
378 dccp_set_seqno(&dp->dccps_swl,
379 max48(dp->dccps_swl, dp->dccps_isr));
380
381 dccp_sync_mss(sk, icsk->icsk_pmtu_cookie);
382
383 /*
384 * Step 10: Process REQUEST state (second part)
385 * If S.state == REQUEST,
386 * / * If we get here, P is a valid Response from the
387 * server (see Step 4), and we should move to
388 * PARTOPEN state. PARTOPEN means send an Ack,
389 * don't send Data packets, retransmit Acks
390 * periodically, and always include any Init Cookie
391 * from the Response * /
392 * S.state := PARTOPEN
393 * Set PARTOPEN timer
394 * Continue with S.state == PARTOPEN
395 * / * Step 12 will send the Ack completing the
396 * three-way handshake * /
397 */
398 dccp_set_state(sk, DCCP_PARTOPEN);
399
400 /* Make sure socket is routed, for correct metrics. */
401 icsk->icsk_af_ops->rebuild_header(sk);
402
403 if (!sock_flag(sk, SOCK_DEAD)) {
404 sk->sk_state_change(sk);
405 sk_wake_async(sk, 0, POLL_OUT);
406 }
407
408 if (sk->sk_write_pending || icsk->icsk_ack.pingpong ||
409 icsk->icsk_accept_queue.rskq_defer_accept) {
410 /* Save one ACK. Data will be ready after
411 * several ticks, if write_pending is set.
412 *
413 * It may be deleted, but with this feature tcpdumps
414 * look so _wonderfully_ clever, that I was not able
415 * to stand against the temptation 8) --ANK
416 */
417 /*
418 * OK, in DCCP we can as well do a similar trick, its
419 * even in the draft, but there is no need for us to
420 * schedule an ack here, as dccp_sendmsg does this for
421 * us, also stated in the draft. -acme
422 */
423 __kfree_skb(skb);
424 return 0;
425 }
426 dccp_send_ack(sk);
427 return -1;
428 }
429
430 out_invalid_packet:
431 /* dccp_v4_do_rcv will send a reset */
432 DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_PACKET_ERROR;
433 return 1;
434 }
435
436 static int dccp_rcv_respond_partopen_state_process(struct sock *sk,
437 struct sk_buff *skb,
438 const struct dccp_hdr *dh,
439 const unsigned len)
440 {
441 int queued = 0;
442
443 switch (dh->dccph_type) {
444 case DCCP_PKT_RESET:
445 inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
446 break;
447 case DCCP_PKT_DATA:
448 if (sk->sk_state == DCCP_RESPOND)
449 break;
450 case DCCP_PKT_DATAACK:
451 case DCCP_PKT_ACK:
452 /*
453 * FIXME: we should be reseting the PARTOPEN (DELACK) timer
454 * here but only if we haven't used the DELACK timer for
455 * something else, like sending a delayed ack for a TIMESTAMP
456 * echo, etc, for now were not clearing it, sending an extra
457 * ACK when there is nothing else to do in DELACK is not a big
458 * deal after all.
459 */
460
461 /* Stop the PARTOPEN timer */
462 if (sk->sk_state == DCCP_PARTOPEN)
463 inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
464
465 dccp_sk(sk)->dccps_osr = DCCP_SKB_CB(skb)->dccpd_seq;
466 dccp_set_state(sk, DCCP_OPEN);
467
468 if (dh->dccph_type == DCCP_PKT_DATAACK ||
469 dh->dccph_type == DCCP_PKT_DATA) {
470 __dccp_rcv_established(sk, skb, dh, len);
471 queued = 1; /* packet was queued
472 (by __dccp_rcv_established) */
473 }
474 break;
475 }
476
477 return queued;
478 }
479
480 int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
481 struct dccp_hdr *dh, unsigned len)
482 {
483 struct dccp_sock *dp = dccp_sk(sk);
484 struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
485 const int old_state = sk->sk_state;
486 int queued = 0;
487
488 /*
489 * Step 3: Process LISTEN state
490 *
491 * If S.state == LISTEN,
492 * If P.type == Request or P contains a valid Init Cookie option,
493 * (* Must scan the packet's options to check for Init
494 * Cookies. Only Init Cookies are processed here,
495 * however; other options are processed in Step 8. This
496 * scan need only be performed if the endpoint uses Init
497 * Cookies *)
498 * (* Generate a new socket and switch to that socket *)
499 * Set S := new socket for this port pair
500 * S.state = RESPOND
501 * Choose S.ISS (initial seqno) or set from Init Cookies
502 * Initialize S.GAR := S.ISS
503 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init
504 * Cookies Continue with S.state == RESPOND
505 * (* A Response packet will be generated in Step 11 *)
506 * Otherwise,
507 * Generate Reset(No Connection) unless P.type == Reset
508 * Drop packet and return
509 */
510 if (sk->sk_state == DCCP_LISTEN) {
511 if (dh->dccph_type == DCCP_PKT_REQUEST) {
512 if (inet_csk(sk)->icsk_af_ops->conn_request(sk,
513 skb) < 0)
514 return 1;
515
516 /* FIXME: do congestion control initialization */
517 goto discard;
518 }
519 if (dh->dccph_type == DCCP_PKT_RESET)
520 goto discard;
521
522 /* Caller (dccp_v4_do_rcv) will send Reset */
523 dcb->dccpd_reset_code = DCCP_RESET_CODE_NO_CONNECTION;
524 return 1;
525 }
526
527 if (sk->sk_state != DCCP_REQUESTING) {
528 if (dccp_check_seqno(sk, skb))
529 goto discard;
530
531 /*
532 * Step 8: Process options and mark acknowledgeable
533 */
534 if (dccp_parse_options(sk, skb))
535 goto discard;
536
537 if (dcb->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ)
538 dccp_event_ack_recv(sk, skb);
539
540 if (dccp_msk(sk)->dccpms_send_ack_vector &&
541 dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk,
542 DCCP_SKB_CB(skb)->dccpd_seq,
543 DCCP_ACKVEC_STATE_RECEIVED))
544 goto discard;
545
546 ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb);
547 ccid_hc_tx_packet_recv(dp->dccps_hc_tx_ccid, sk, skb);
548 }
549
550 /*
551 * Step 9: Process Reset
552 * If P.type == Reset,
553 * Tear down connection
554 * S.state := TIMEWAIT
555 * Set TIMEWAIT timer
556 * Drop packet and return
557 */
558 if (dh->dccph_type == DCCP_PKT_RESET) {
559 dccp_rcv_reset(sk, skb);
560 return 0;
561 /*
562 * Step 7: Check for unexpected packet types
563 * If (S.is_server and P.type == CloseReq)
564 * or (S.is_server and P.type == Response)
565 * or (S.is_client and P.type == Request)
566 * or (S.state == RESPOND and P.type == Data),
567 * Send Sync packet acknowledging P.seqno
568 * Drop packet and return
569 */
570 } else if ((dp->dccps_role != DCCP_ROLE_CLIENT &&
571 (dh->dccph_type == DCCP_PKT_RESPONSE ||
572 dh->dccph_type == DCCP_PKT_CLOSEREQ)) ||
573 (dp->dccps_role == DCCP_ROLE_CLIENT &&
574 dh->dccph_type == DCCP_PKT_REQUEST) ||
575 (sk->sk_state == DCCP_RESPOND &&
576 dh->dccph_type == DCCP_PKT_DATA)) {
577 dccp_send_sync(sk, dcb->dccpd_seq, DCCP_PKT_SYNC);
578 goto discard;
579 } else if (dh->dccph_type == DCCP_PKT_CLOSEREQ) {
580 dccp_rcv_closereq(sk, skb);
581 goto discard;
582 } else if (dh->dccph_type == DCCP_PKT_CLOSE) {
583 dccp_rcv_close(sk, skb);
584 return 0;
585 }
586
587 switch (sk->sk_state) {
588 case DCCP_CLOSED:
589 dcb->dccpd_reset_code = DCCP_RESET_CODE_NO_CONNECTION;
590 return 1;
591
592 case DCCP_REQUESTING:
593 /* FIXME: do congestion control initialization */
594
595 queued = dccp_rcv_request_sent_state_process(sk, skb, dh, len);
596 if (queued >= 0)
597 return queued;
598
599 __kfree_skb(skb);
600 return 0;
601
602 case DCCP_RESPOND:
603 case DCCP_PARTOPEN:
604 queued = dccp_rcv_respond_partopen_state_process(sk, skb,
605 dh, len);
606 break;
607 }
608
609 if (dh->dccph_type == DCCP_PKT_ACK ||
610 dh->dccph_type == DCCP_PKT_DATAACK) {
611 switch (old_state) {
612 case DCCP_PARTOPEN:
613 sk->sk_state_change(sk);
614 sk_wake_async(sk, 0, POLL_OUT);
615 break;
616 }
617 } else if (unlikely(dh->dccph_type == DCCP_PKT_SYNC)) {
618 dccp_send_sync(sk, dcb->dccpd_seq, DCCP_PKT_SYNCACK);
619 goto discard;
620 }
621
622 if (!queued) {
623 discard:
624 __kfree_skb(skb);
625 }
626 return 0;
627 }
628
629 EXPORT_SYMBOL_GPL(dccp_rcv_state_process);
630
631 /**
632 * dccp_sample_rtt - Validate and finalise computation of RTT sample
633 * @delta: number of microseconds between packet and acknowledgment
634 * The routine is kept generic to work in different contexts. It should be
635 * called immediately when the ACK used for the RTT sample arrives.
636 */
637 u32 dccp_sample_rtt(struct sock *sk, long delta)
638 {
639 /* dccpor_elapsed_time is either zeroed out or set and > 0 */
640 delta -= dccp_sk(sk)->dccps_options_received.dccpor_elapsed_time * 10;
641
642 if (unlikely(delta <= 0)) {
643 DCCP_WARN("unusable RTT sample %ld, using min\n", delta);
644 return DCCP_SANE_RTT_MIN;
645 }
646 if (unlikely(delta > DCCP_SANE_RTT_MAX)) {
647 DCCP_WARN("RTT sample %ld too large, using max\n", delta);
648 return DCCP_SANE_RTT_MAX;
649 }
650
651 return delta;
652 }
653
654 EXPORT_SYMBOL_GPL(dccp_sample_rtt);
WRT350N Kernel Patches