4 * An implementation of the DCCP protocol
5 * Arnaldo Carvalho de Melo <acme@conectiva.com.br>
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.
13 #include <linux/dccp.h>
14 #include <linux/skbuff.h>
15 #include <linux/slab.h>
23 /* rate-limit for syncs in reply to sequence-invalid packets; RFC 4340, 7.5.4 */
24 int sysctl_dccp_sync_ratelimit __read_mostly
= HZ
/ 8;
26 static void dccp_enqueue_skb(struct sock
*sk
, struct sk_buff
*skb
)
28 __skb_pull(skb
, dccp_hdr(skb
)->dccph_doff
* 4);
29 __skb_queue_tail(&sk
->sk_receive_queue
, skb
);
30 skb_set_owner_r(skb
, sk
);
31 sk
->sk_data_ready(sk
, 0);
34 static void dccp_fin(struct sock
*sk
, struct sk_buff
*skb
)
37 * On receiving Close/CloseReq, both RD/WR shutdown are performed.
38 * RFC 4340, 8.3 says that we MAY send further Data/DataAcks after
39 * receiving the closing segment, but there is no guarantee that such
40 * data will be processed at all.
42 sk
->sk_shutdown
= SHUTDOWN_MASK
;
43 sock_set_flag(sk
, SOCK_DONE
);
44 dccp_enqueue_skb(sk
, skb
);
47 static int dccp_rcv_close(struct sock
*sk
, struct sk_buff
*skb
)
51 switch (sk
->sk_state
) {
53 * We ignore Close when received in one of the following states:
54 * - CLOSED (may be a late or duplicate packet)
55 * - PASSIVE_CLOSEREQ (the peer has sent a CloseReq earlier)
56 * - RESPOND (already handled by dccp_check_req)
60 * Simultaneous-close: receiving a Close after sending one. This
61 * can happen if both client and server perform active-close and
62 * will result in an endless ping-pong of crossing and retrans-
63 * mitted Close packets, which only terminates when one of the
64 * nodes times out (min. 64 seconds). Quicker convergence can be
65 * achieved when one of the nodes acts as tie-breaker.
66 * This is ok as both ends are done with data transfer and each
67 * end is just waiting for the other to acknowledge termination.
69 if (dccp_sk(sk
)->dccps_role
!= DCCP_ROLE_CLIENT
)
73 case DCCP_ACTIVE_CLOSEREQ
:
74 dccp_send_reset(sk
, DCCP_RESET_CODE_CLOSED
);
79 /* Give waiting application a chance to read pending data */
82 dccp_set_state(sk
, DCCP_PASSIVE_CLOSE
);
84 case DCCP_PASSIVE_CLOSE
:
86 * Retransmitted Close: we have already enqueued the first one.
88 sk_wake_async(sk
, SOCK_WAKE_WAITD
, POLL_HUP
);
93 static int dccp_rcv_closereq(struct sock
*sk
, struct sk_buff
*skb
)
98 * Step 7: Check for unexpected packet types
99 * If (S.is_server and P.type == CloseReq)
100 * Send Sync packet acknowledging P.seqno
101 * Drop packet and return
103 if (dccp_sk(sk
)->dccps_role
!= DCCP_ROLE_CLIENT
) {
104 dccp_send_sync(sk
, DCCP_SKB_CB(skb
)->dccpd_seq
, DCCP_PKT_SYNC
);
108 /* Step 13: process relevant Client states < CLOSEREQ */
109 switch (sk
->sk_state
) {
110 case DCCP_REQUESTING
:
111 dccp_send_close(sk
, 0);
112 dccp_set_state(sk
, DCCP_CLOSING
);
116 /* Give waiting application a chance to read pending data */
119 dccp_set_state(sk
, DCCP_PASSIVE_CLOSEREQ
);
121 case DCCP_PASSIVE_CLOSEREQ
:
122 sk_wake_async(sk
, SOCK_WAKE_WAITD
, POLL_HUP
);
127 static u16
dccp_reset_code_convert(const u8 code
)
129 const u16 error_code
[] = {
130 [DCCP_RESET_CODE_CLOSED
] = 0, /* normal termination */
131 [DCCP_RESET_CODE_UNSPECIFIED
] = 0, /* nothing known */
132 [DCCP_RESET_CODE_ABORTED
] = ECONNRESET
,
134 [DCCP_RESET_CODE_NO_CONNECTION
] = ECONNREFUSED
,
135 [DCCP_RESET_CODE_CONNECTION_REFUSED
] = ECONNREFUSED
,
136 [DCCP_RESET_CODE_TOO_BUSY
] = EUSERS
,
137 [DCCP_RESET_CODE_AGGRESSION_PENALTY
] = EDQUOT
,
139 [DCCP_RESET_CODE_PACKET_ERROR
] = ENOMSG
,
140 [DCCP_RESET_CODE_BAD_INIT_COOKIE
] = EBADR
,
141 [DCCP_RESET_CODE_BAD_SERVICE_CODE
] = EBADRQC
,
142 [DCCP_RESET_CODE_OPTION_ERROR
] = EILSEQ
,
143 [DCCP_RESET_CODE_MANDATORY_ERROR
] = EOPNOTSUPP
,
146 return code
>= DCCP_MAX_RESET_CODES
? 0 : error_code
[code
];
149 static void dccp_rcv_reset(struct sock
*sk
, struct sk_buff
*skb
)
151 u16 err
= dccp_reset_code_convert(dccp_hdr_reset(skb
)->dccph_reset_code
);
155 /* Queue the equivalent of TCP fin so that dccp_recvmsg exits the loop */
158 if (err
&& !sock_flag(sk
, SOCK_DEAD
))
159 sk_wake_async(sk
, SOCK_WAKE_IO
, POLL_ERR
);
160 dccp_time_wait(sk
, DCCP_TIME_WAIT
, 0);
163 static void dccp_event_ack_recv(struct sock
*sk
, struct sk_buff
*skb
)
165 struct dccp_sock
*dp
= dccp_sk(sk
);
167 if (dp
->dccps_hc_rx_ackvec
!= NULL
)
168 dccp_ackvec_check_rcv_ackno(dp
->dccps_hc_rx_ackvec
, sk
,
169 DCCP_SKB_CB(skb
)->dccpd_ack_seq
);
172 static void dccp_deliver_input_to_ccids(struct sock
*sk
, struct sk_buff
*skb
)
174 const struct dccp_sock
*dp
= dccp_sk(sk
);
176 /* Don't deliver to RX CCID when node has shut down read end. */
177 if (!(sk
->sk_shutdown
& RCV_SHUTDOWN
))
178 ccid_hc_rx_packet_recv(dp
->dccps_hc_rx_ccid
, sk
, skb
);
180 * Until the TX queue has been drained, we can not honour SHUT_WR, since
181 * we need received feedback as input to adjust congestion control.
183 if (sk
->sk_write_queue
.qlen
> 0 || !(sk
->sk_shutdown
& SEND_SHUTDOWN
))
184 ccid_hc_tx_packet_recv(dp
->dccps_hc_tx_ccid
, sk
, skb
);
187 static int dccp_check_seqno(struct sock
*sk
, struct sk_buff
*skb
)
189 const struct dccp_hdr
*dh
= dccp_hdr(skb
);
190 struct dccp_sock
*dp
= dccp_sk(sk
);
191 u64 lswl
, lawl
, seqno
= DCCP_SKB_CB(skb
)->dccpd_seq
,
192 ackno
= DCCP_SKB_CB(skb
)->dccpd_ack_seq
;
195 * Step 5: Prepare sequence numbers for Sync
196 * If P.type == Sync or P.type == SyncAck,
197 * If S.AWL <= P.ackno <= S.AWH and P.seqno >= S.SWL,
198 * / * P is valid, so update sequence number variables
199 * accordingly. After this update, P will pass the tests
200 * in Step 6. A SyncAck is generated if necessary in
202 * Update S.GSR, S.SWL, S.SWH
204 * Drop packet and return
206 if (dh
->dccph_type
== DCCP_PKT_SYNC
||
207 dh
->dccph_type
== DCCP_PKT_SYNCACK
) {
208 if (between48(ackno
, dp
->dccps_awl
, dp
->dccps_awh
) &&
209 dccp_delta_seqno(dp
->dccps_swl
, seqno
) >= 0)
210 dccp_update_gsr(sk
, seqno
);
216 * Step 6: Check sequence numbers
217 * Let LSWL = S.SWL and LAWL = S.AWL
218 * If P.type == CloseReq or P.type == Close or P.type == Reset,
219 * LSWL := S.GSR + 1, LAWL := S.GAR
220 * If LSWL <= P.seqno <= S.SWH
221 * and (P.ackno does not exist or LAWL <= P.ackno <= S.AWH),
222 * Update S.GSR, S.SWL, S.SWH
226 lswl
= dp
->dccps_swl
;
227 lawl
= dp
->dccps_awl
;
229 if (dh
->dccph_type
== DCCP_PKT_CLOSEREQ
||
230 dh
->dccph_type
== DCCP_PKT_CLOSE
||
231 dh
->dccph_type
== DCCP_PKT_RESET
) {
232 lswl
= ADD48(dp
->dccps_gsr
, 1);
233 lawl
= dp
->dccps_gar
;
236 if (between48(seqno
, lswl
, dp
->dccps_swh
) &&
237 (ackno
== DCCP_PKT_WITHOUT_ACK_SEQ
||
238 between48(ackno
, lawl
, dp
->dccps_awh
))) {
239 dccp_update_gsr(sk
, seqno
);
241 if (dh
->dccph_type
!= DCCP_PKT_SYNC
&&
242 (ackno
!= DCCP_PKT_WITHOUT_ACK_SEQ
))
243 dp
->dccps_gar
= ackno
;
245 unsigned long now
= jiffies
;
247 * Step 6: Check sequence numbers
249 * If P.type == Reset,
250 * Send Sync packet acknowledging S.GSR
252 * Send Sync packet acknowledging P.seqno
253 * Drop packet and return
255 * These Syncs are rate-limited as per RFC 4340, 7.5.4:
256 * at most 1 / (dccp_sync_rate_limit * HZ) Syncs per second.
258 if (time_before(now
, (dp
->dccps_rate_last
+
259 sysctl_dccp_sync_ratelimit
)))
262 DCCP_WARN("DCCP: Step 6 failed for %s packet, "
263 "(LSWL(%llu) <= P.seqno(%llu) <= S.SWH(%llu)) and "
264 "(P.ackno %s or LAWL(%llu) <= P.ackno(%llu) <= S.AWH(%llu), "
265 "sending SYNC...\n", dccp_packet_name(dh
->dccph_type
),
266 (unsigned long long) lswl
, (unsigned long long) seqno
,
267 (unsigned long long) dp
->dccps_swh
,
268 (ackno
== DCCP_PKT_WITHOUT_ACK_SEQ
) ? "doesn't exist"
270 (unsigned long long) lawl
, (unsigned long long) ackno
,
271 (unsigned long long) dp
->dccps_awh
);
273 dp
->dccps_rate_last
= now
;
275 if (dh
->dccph_type
== DCCP_PKT_RESET
)
276 seqno
= dp
->dccps_gsr
;
277 dccp_send_sync(sk
, seqno
, DCCP_PKT_SYNC
);
284 static int __dccp_rcv_established(struct sock
*sk
, struct sk_buff
*skb
,
285 const struct dccp_hdr
*dh
, const unsigned len
)
287 struct dccp_sock
*dp
= dccp_sk(sk
);
289 switch (dccp_hdr(skb
)->dccph_type
) {
290 case DCCP_PKT_DATAACK
:
292 dccp_enqueue_skb(sk
, skb
);
298 * Step 9: Process Reset
299 * If P.type == Reset,
300 * Tear down connection
301 * S.state := TIMEWAIT
303 * Drop packet and return
305 dccp_rcv_reset(sk
, skb
);
307 case DCCP_PKT_CLOSEREQ
:
308 if (dccp_rcv_closereq(sk
, skb
))
312 if (dccp_rcv_close(sk
, skb
))
315 case DCCP_PKT_REQUEST
:
317 * or (S.is_server and P.type == Response)
318 * or (S.is_client and P.type == Request)
319 * or (S.state >= OPEN and P.type == Request
320 * and P.seqno >= S.OSR)
321 * or (S.state >= OPEN and P.type == Response
322 * and P.seqno >= S.OSR)
323 * or (S.state == RESPOND and P.type == Data),
324 * Send Sync packet acknowledging P.seqno
325 * Drop packet and return
327 if (dp
->dccps_role
!= DCCP_ROLE_LISTEN
)
330 case DCCP_PKT_RESPONSE
:
331 if (dp
->dccps_role
!= DCCP_ROLE_CLIENT
)
334 if (dccp_delta_seqno(dp
->dccps_osr
,
335 DCCP_SKB_CB(skb
)->dccpd_seq
) >= 0) {
337 dccp_send_sync(sk
, DCCP_SKB_CB(skb
)->dccpd_seq
,
342 dccp_send_sync(sk
, DCCP_SKB_CB(skb
)->dccpd_seq
,
345 * From RFC 4340, sec. 5.7
347 * As with DCCP-Ack packets, DCCP-Sync and DCCP-SyncAck packets
348 * MAY have non-zero-length application data areas, whose
349 * contents receivers MUST ignore.
354 DCCP_INC_STATS_BH(DCCP_MIB_INERRS
);
360 int dccp_rcv_established(struct sock
*sk
, struct sk_buff
*skb
,
361 const struct dccp_hdr
*dh
, const unsigned len
)
363 struct dccp_sock
*dp
= dccp_sk(sk
);
365 if (dccp_check_seqno(sk
, skb
))
368 if (dccp_parse_options(sk
, NULL
, skb
))
371 if (DCCP_SKB_CB(skb
)->dccpd_ack_seq
!= DCCP_PKT_WITHOUT_ACK_SEQ
)
372 dccp_event_ack_recv(sk
, skb
);
374 if (dp
->dccps_hc_rx_ackvec
!= NULL
&&
375 dccp_ackvec_add(dp
->dccps_hc_rx_ackvec
, sk
,
376 DCCP_SKB_CB(skb
)->dccpd_seq
,
377 DCCP_ACKVEC_STATE_RECEIVED
))
379 dccp_deliver_input_to_ccids(sk
, skb
);
381 return __dccp_rcv_established(sk
, skb
, dh
, len
);
387 EXPORT_SYMBOL_GPL(dccp_rcv_established
);
389 static int dccp_rcv_request_sent_state_process(struct sock
*sk
,
391 const struct dccp_hdr
*dh
,
395 * Step 4: Prepare sequence numbers in REQUEST
396 * If S.state == REQUEST,
397 * If (P.type == Response or P.type == Reset)
398 * and S.AWL <= P.ackno <= S.AWH,
399 * / * Set sequence number variables corresponding to the
400 * other endpoint, so P will pass the tests in Step 6 * /
401 * Set S.GSR, S.ISR, S.SWL, S.SWH
402 * / * Response processing continues in Step 10; Reset
403 * processing continues in Step 9 * /
405 if (dh
->dccph_type
== DCCP_PKT_RESPONSE
) {
406 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
407 struct dccp_sock
*dp
= dccp_sk(sk
);
408 long tstamp
= dccp_timestamp();
410 if (!between48(DCCP_SKB_CB(skb
)->dccpd_ack_seq
,
411 dp
->dccps_awl
, dp
->dccps_awh
)) {
412 dccp_pr_debug("invalid ackno: S.AWL=%llu, "
413 "P.ackno=%llu, S.AWH=%llu\n",
414 (unsigned long long)dp
->dccps_awl
,
415 (unsigned long long)DCCP_SKB_CB(skb
)->dccpd_ack_seq
,
416 (unsigned long long)dp
->dccps_awh
);
417 goto out_invalid_packet
;
421 * If option processing (Step 8) failed, return 1 here so that
422 * dccp_v4_do_rcv() sends a Reset. The Reset code depends on
423 * the option type and is set in dccp_parse_options().
425 if (dccp_parse_options(sk
, NULL
, skb
))
428 /* Obtain usec RTT sample from SYN exchange (used by TFRC). */
429 if (likely(dp
->dccps_options_received
.dccpor_timestamp_echo
))
430 dp
->dccps_syn_rtt
= dccp_sample_rtt(sk
, 10 * (tstamp
-
431 dp
->dccps_options_received
.dccpor_timestamp_echo
));
433 /* Stop the REQUEST timer */
434 inet_csk_clear_xmit_timer(sk
, ICSK_TIME_RETRANS
);
435 WARN_ON(sk
->sk_send_head
== NULL
);
436 kfree_skb(sk
->sk_send_head
);
437 sk
->sk_send_head
= NULL
;
439 dp
->dccps_isr
= DCCP_SKB_CB(skb
)->dccpd_seq
;
440 dccp_update_gsr(sk
, dp
->dccps_isr
);
442 * SWL and AWL are initially adjusted so that they are not less than
443 * the initial Sequence Numbers received and sent, respectively:
444 * SWL := max(GSR + 1 - floor(W/4), ISR),
445 * AWL := max(GSS - W' + 1, ISS).
446 * These adjustments MUST be applied only at the beginning of the
449 * AWL was adjusted in dccp_v4_connect -acme
451 dccp_set_seqno(&dp
->dccps_swl
,
452 max48(dp
->dccps_swl
, dp
->dccps_isr
));
454 dccp_sync_mss(sk
, icsk
->icsk_pmtu_cookie
);
457 * Step 10: Process REQUEST state (second part)
458 * If S.state == REQUEST,
459 * / * If we get here, P is a valid Response from the
460 * server (see Step 4), and we should move to
461 * PARTOPEN state. PARTOPEN means send an Ack,
462 * don't send Data packets, retransmit Acks
463 * periodically, and always include any Init Cookie
464 * from the Response * /
465 * S.state := PARTOPEN
467 * Continue with S.state == PARTOPEN
468 * / * Step 12 will send the Ack completing the
469 * three-way handshake * /
471 dccp_set_state(sk
, DCCP_PARTOPEN
);
474 * If feature negotiation was successful, activate features now;
475 * an activation failure means that this host could not activate
476 * one ore more features (e.g. insufficient memory), which would
477 * leave at least one feature in an undefined state.
479 if (dccp_feat_activate_values(sk
, &dp
->dccps_featneg
))
480 goto unable_to_proceed
;
482 /* Make sure socket is routed, for correct metrics. */
483 icsk
->icsk_af_ops
->rebuild_header(sk
);
485 if (!sock_flag(sk
, SOCK_DEAD
)) {
486 sk
->sk_state_change(sk
);
487 sk_wake_async(sk
, SOCK_WAKE_IO
, POLL_OUT
);
490 if (sk
->sk_write_pending
|| icsk
->icsk_ack
.pingpong
||
491 icsk
->icsk_accept_queue
.rskq_defer_accept
) {
492 /* Save one ACK. Data will be ready after
493 * several ticks, if write_pending is set.
495 * It may be deleted, but with this feature tcpdumps
496 * look so _wonderfully_ clever, that I was not able
497 * to stand against the temptation 8) --ANK
500 * OK, in DCCP we can as well do a similar trick, its
501 * even in the draft, but there is no need for us to
502 * schedule an ack here, as dccp_sendmsg does this for
503 * us, also stated in the draft. -acme
513 /* dccp_v4_do_rcv will send a reset */
514 DCCP_SKB_CB(skb
)->dccpd_reset_code
= DCCP_RESET_CODE_PACKET_ERROR
;
518 DCCP_SKB_CB(skb
)->dccpd_reset_code
= DCCP_RESET_CODE_ABORTED
;
520 * We mark this socket as no longer usable, so that the loop in
521 * dccp_sendmsg() terminates and the application gets notified.
523 dccp_set_state(sk
, DCCP_CLOSED
);
528 static int dccp_rcv_respond_partopen_state_process(struct sock
*sk
,
530 const struct dccp_hdr
*dh
,
533 struct dccp_sock
*dp
= dccp_sk(sk
);
534 u32 sample
= dp
->dccps_options_received
.dccpor_timestamp_echo
;
537 switch (dh
->dccph_type
) {
539 inet_csk_clear_xmit_timer(sk
, ICSK_TIME_DACK
);
542 if (sk
->sk_state
== DCCP_RESPOND
)
544 case DCCP_PKT_DATAACK
:
547 /* Stop the PARTOPEN timer */
548 if (sk
->sk_state
== DCCP_PARTOPEN
)
549 inet_csk_clear_xmit_timer(sk
, ICSK_TIME_DACK
);
551 /* Obtain usec RTT sample from SYN exchange (used by TFRC). */
552 if (likely(sample
)) {
553 long delta
= dccp_timestamp() - sample
;
555 dp
->dccps_syn_rtt
= dccp_sample_rtt(sk
, 10 * delta
);
558 dp
->dccps_osr
= DCCP_SKB_CB(skb
)->dccpd_seq
;
559 dccp_set_state(sk
, DCCP_OPEN
);
561 if (dh
->dccph_type
== DCCP_PKT_DATAACK
||
562 dh
->dccph_type
== DCCP_PKT_DATA
) {
563 __dccp_rcv_established(sk
, skb
, dh
, len
);
564 queued
= 1; /* packet was queued
565 (by __dccp_rcv_established) */
573 int dccp_rcv_state_process(struct sock
*sk
, struct sk_buff
*skb
,
574 struct dccp_hdr
*dh
, unsigned len
)
576 struct dccp_sock
*dp
= dccp_sk(sk
);
577 struct dccp_skb_cb
*dcb
= DCCP_SKB_CB(skb
);
578 const int old_state
= sk
->sk_state
;
582 * Step 3: Process LISTEN state
584 * If S.state == LISTEN,
585 * If P.type == Request or P contains a valid Init Cookie option,
586 * (* Must scan the packet's options to check for Init
587 * Cookies. Only Init Cookies are processed here,
588 * however; other options are processed in Step 8. This
589 * scan need only be performed if the endpoint uses Init
591 * (* Generate a new socket and switch to that socket *)
592 * Set S := new socket for this port pair
594 * Choose S.ISS (initial seqno) or set from Init Cookies
595 * Initialize S.GAR := S.ISS
596 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init
597 * Cookies Continue with S.state == RESPOND
598 * (* A Response packet will be generated in Step 11 *)
600 * Generate Reset(No Connection) unless P.type == Reset
601 * Drop packet and return
603 if (sk
->sk_state
== DCCP_LISTEN
) {
604 if (dh
->dccph_type
== DCCP_PKT_REQUEST
) {
605 if (inet_csk(sk
)->icsk_af_ops
->conn_request(sk
,
610 if (dh
->dccph_type
== DCCP_PKT_RESET
)
613 /* Caller (dccp_v4_do_rcv) will send Reset */
614 dcb
->dccpd_reset_code
= DCCP_RESET_CODE_NO_CONNECTION
;
618 if (sk
->sk_state
!= DCCP_REQUESTING
&& sk
->sk_state
!= DCCP_RESPOND
) {
619 if (dccp_check_seqno(sk
, skb
))
623 * Step 8: Process options and mark acknowledgeable
625 if (dccp_parse_options(sk
, NULL
, skb
))
628 if (dcb
->dccpd_ack_seq
!= DCCP_PKT_WITHOUT_ACK_SEQ
)
629 dccp_event_ack_recv(sk
, skb
);
631 if (dp
->dccps_hc_rx_ackvec
!= NULL
&&
632 dccp_ackvec_add(dp
->dccps_hc_rx_ackvec
, sk
,
633 DCCP_SKB_CB(skb
)->dccpd_seq
,
634 DCCP_ACKVEC_STATE_RECEIVED
))
637 dccp_deliver_input_to_ccids(sk
, skb
);
641 * Step 9: Process Reset
642 * If P.type == Reset,
643 * Tear down connection
644 * S.state := TIMEWAIT
646 * Drop packet and return
648 if (dh
->dccph_type
== DCCP_PKT_RESET
) {
649 dccp_rcv_reset(sk
, skb
);
652 * Step 7: Check for unexpected packet types
653 * If (S.is_server and P.type == Response)
654 * or (S.is_client and P.type == Request)
655 * or (S.state == RESPOND and P.type == Data),
656 * Send Sync packet acknowledging P.seqno
657 * Drop packet and return
659 } else if ((dp
->dccps_role
!= DCCP_ROLE_CLIENT
&&
660 dh
->dccph_type
== DCCP_PKT_RESPONSE
) ||
661 (dp
->dccps_role
== DCCP_ROLE_CLIENT
&&
662 dh
->dccph_type
== DCCP_PKT_REQUEST
) ||
663 (sk
->sk_state
== DCCP_RESPOND
&&
664 dh
->dccph_type
== DCCP_PKT_DATA
)) {
665 dccp_send_sync(sk
, dcb
->dccpd_seq
, DCCP_PKT_SYNC
);
667 } else if (dh
->dccph_type
== DCCP_PKT_CLOSEREQ
) {
668 if (dccp_rcv_closereq(sk
, skb
))
671 } else if (dh
->dccph_type
== DCCP_PKT_CLOSE
) {
672 if (dccp_rcv_close(sk
, skb
))
677 switch (sk
->sk_state
) {
679 dcb
->dccpd_reset_code
= DCCP_RESET_CODE_NO_CONNECTION
;
682 case DCCP_REQUESTING
:
683 queued
= dccp_rcv_request_sent_state_process(sk
, skb
, dh
, len
);
692 queued
= dccp_rcv_respond_partopen_state_process(sk
, skb
,
697 if (dh
->dccph_type
== DCCP_PKT_ACK
||
698 dh
->dccph_type
== DCCP_PKT_DATAACK
) {
701 sk
->sk_state_change(sk
);
702 sk_wake_async(sk
, SOCK_WAKE_IO
, POLL_OUT
);
705 } else if (unlikely(dh
->dccph_type
== DCCP_PKT_SYNC
)) {
706 dccp_send_sync(sk
, dcb
->dccpd_seq
, DCCP_PKT_SYNCACK
);
717 EXPORT_SYMBOL_GPL(dccp_rcv_state_process
);
720 * dccp_sample_rtt - Validate and finalise computation of RTT sample
721 * @delta: number of microseconds between packet and acknowledgment
722 * The routine is kept generic to work in different contexts. It should be
723 * called immediately when the ACK used for the RTT sample arrives.
725 u32
dccp_sample_rtt(struct sock
*sk
, long delta
)
727 /* dccpor_elapsed_time is either zeroed out or set and > 0 */
728 delta
-= dccp_sk(sk
)->dccps_options_received
.dccpor_elapsed_time
* 10;
730 if (unlikely(delta
<= 0)) {
731 DCCP_WARN("unusable RTT sample %ld, using min\n", delta
);
732 return DCCP_SANE_RTT_MIN
;
734 if (unlikely(delta
> DCCP_SANE_RTT_MAX
)) {
735 DCCP_WARN("RTT sample %ld too large, using max\n", delta
);
736 return DCCP_SANE_RTT_MAX
;