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>
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;
25 static void dccp_fin(struct sock
*sk
, struct sk_buff
*skb
)
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);
35 static int dccp_rcv_close(struct sock
*sk
, struct sk_buff
*skb
)
39 switch (sk
->sk_state
) {
41 * We ignore Close when received in one of the following states:
42 * - CLOSED (may be a late or duplicate packet)
43 * - PASSIVE_CLOSEREQ (the peer has sent a CloseReq earlier)
44 * - RESPOND (already handled by dccp_check_req)
48 * Simultaneous-close: receiving a Close after sending one. This
49 * can happen if both client and server perform active-close and
50 * will result in an endless ping-pong of crossing and retrans-
51 * mitted Close packets, which only terminates when one of the
52 * nodes times out (min. 64 seconds). Quicker convergence can be
53 * achieved when one of the nodes acts as tie-breaker.
54 * This is ok as both ends are done with data transfer and each
55 * end is just waiting for the other to acknowledge termination.
57 if (dccp_sk(sk
)->dccps_role
!= DCCP_ROLE_CLIENT
)
61 case DCCP_ACTIVE_CLOSEREQ
:
62 dccp_send_reset(sk
, DCCP_RESET_CODE_CLOSED
);
67 /* Give waiting application a chance to read pending data */
70 dccp_set_state(sk
, DCCP_PASSIVE_CLOSE
);
72 case DCCP_PASSIVE_CLOSE
:
74 * Retransmitted Close: we have already enqueued the first one.
76 sk_wake_async(sk
, SOCK_WAKE_WAITD
, POLL_HUP
);
81 static int dccp_rcv_closereq(struct sock
*sk
, struct sk_buff
*skb
)
86 * Step 7: Check for unexpected packet types
87 * If (S.is_server and P.type == CloseReq)
88 * Send Sync packet acknowledging P.seqno
89 * Drop packet and return
91 if (dccp_sk(sk
)->dccps_role
!= DCCP_ROLE_CLIENT
) {
92 dccp_send_sync(sk
, DCCP_SKB_CB(skb
)->dccpd_seq
, DCCP_PKT_SYNC
);
96 /* Step 13: process relevant Client states < CLOSEREQ */
97 switch (sk
->sk_state
) {
99 dccp_send_close(sk
, 0);
100 dccp_set_state(sk
, DCCP_CLOSING
);
104 /* Give waiting application a chance to read pending data */
107 dccp_set_state(sk
, DCCP_PASSIVE_CLOSEREQ
);
109 case DCCP_PASSIVE_CLOSEREQ
:
110 sk_wake_async(sk
, SOCK_WAKE_WAITD
, POLL_HUP
);
115 static u8
dccp_reset_code_convert(const u8 code
)
117 const u8 error_code
[] = {
118 [DCCP_RESET_CODE_CLOSED
] = 0, /* normal termination */
119 [DCCP_RESET_CODE_UNSPECIFIED
] = 0, /* nothing known */
120 [DCCP_RESET_CODE_ABORTED
] = ECONNRESET
,
122 [DCCP_RESET_CODE_NO_CONNECTION
] = ECONNREFUSED
,
123 [DCCP_RESET_CODE_CONNECTION_REFUSED
] = ECONNREFUSED
,
124 [DCCP_RESET_CODE_TOO_BUSY
] = EUSERS
,
125 [DCCP_RESET_CODE_AGGRESSION_PENALTY
] = EDQUOT
,
127 [DCCP_RESET_CODE_PACKET_ERROR
] = ENOMSG
,
128 [DCCP_RESET_CODE_BAD_INIT_COOKIE
] = EBADR
,
129 [DCCP_RESET_CODE_BAD_SERVICE_CODE
] = EBADRQC
,
130 [DCCP_RESET_CODE_OPTION_ERROR
] = EILSEQ
,
131 [DCCP_RESET_CODE_MANDATORY_ERROR
] = EOPNOTSUPP
,
134 return code
>= DCCP_MAX_RESET_CODES
? 0 : error_code
[code
];
137 static void dccp_rcv_reset(struct sock
*sk
, struct sk_buff
*skb
)
139 u8 err
= dccp_reset_code_convert(dccp_hdr_reset(skb
)->dccph_reset_code
);
143 /* Queue the equivalent of TCP fin so that dccp_recvmsg exits the loop */
146 if (err
&& !sock_flag(sk
, SOCK_DEAD
))
147 sk_wake_async(sk
, SOCK_WAKE_IO
, POLL_ERR
);
148 dccp_time_wait(sk
, DCCP_TIME_WAIT
, 0);
151 static void dccp_event_ack_recv(struct sock
*sk
, struct sk_buff
*skb
)
153 struct dccp_sock
*dp
= dccp_sk(sk
);
155 if (dccp_msk(sk
)->dccpms_send_ack_vector
)
156 dccp_ackvec_check_rcv_ackno(dp
->dccps_hc_rx_ackvec
, sk
,
157 DCCP_SKB_CB(skb
)->dccpd_ack_seq
);
160 static void dccp_deliver_input_to_ccids(struct sock
*sk
, struct sk_buff
*skb
)
162 const struct dccp_sock
*dp
= dccp_sk(sk
);
164 /* Don't deliver to RX CCID when node has shut down read end. */
165 if (!(sk
->sk_shutdown
& RCV_SHUTDOWN
))
166 ccid_hc_rx_packet_recv(dp
->dccps_hc_rx_ccid
, sk
, skb
);
168 * Until the TX queue has been drained, we can not honour SHUT_WR, since
169 * we need received feedback as input to adjust congestion control.
171 if (sk
->sk_write_queue
.qlen
> 0 || !(sk
->sk_shutdown
& SEND_SHUTDOWN
))
172 ccid_hc_tx_packet_recv(dp
->dccps_hc_tx_ccid
, sk
, skb
);
175 static int dccp_check_seqno(struct sock
*sk
, struct sk_buff
*skb
)
177 const struct dccp_hdr
*dh
= dccp_hdr(skb
);
178 struct dccp_sock
*dp
= dccp_sk(sk
);
179 u64 lswl
, lawl
, seqno
= DCCP_SKB_CB(skb
)->dccpd_seq
,
180 ackno
= DCCP_SKB_CB(skb
)->dccpd_ack_seq
;
183 * Step 5: Prepare sequence numbers for Sync
184 * If P.type == Sync or P.type == SyncAck,
185 * If S.AWL <= P.ackno <= S.AWH and P.seqno >= S.SWL,
186 * / * P is valid, so update sequence number variables
187 * accordingly. After this update, P will pass the tests
188 * in Step 6. A SyncAck is generated if necessary in
190 * Update S.GSR, S.SWL, S.SWH
192 * Drop packet and return
194 if (dh
->dccph_type
== DCCP_PKT_SYNC
||
195 dh
->dccph_type
== DCCP_PKT_SYNCACK
) {
196 if (between48(ackno
, dp
->dccps_awl
, dp
->dccps_awh
) &&
197 dccp_delta_seqno(dp
->dccps_swl
, seqno
) >= 0)
198 dccp_update_gsr(sk
, seqno
);
204 * Step 6: Check sequence numbers
205 * Let LSWL = S.SWL and LAWL = S.AWL
206 * If P.type == CloseReq or P.type == Close or P.type == Reset,
207 * LSWL := S.GSR + 1, LAWL := S.GAR
208 * If LSWL <= P.seqno <= S.SWH
209 * and (P.ackno does not exist or LAWL <= P.ackno <= S.AWH),
210 * Update S.GSR, S.SWL, S.SWH
214 lswl
= dp
->dccps_swl
;
215 lawl
= dp
->dccps_awl
;
217 if (dh
->dccph_type
== DCCP_PKT_CLOSEREQ
||
218 dh
->dccph_type
== DCCP_PKT_CLOSE
||
219 dh
->dccph_type
== DCCP_PKT_RESET
) {
220 lswl
= ADD48(dp
->dccps_gsr
, 1);
221 lawl
= dp
->dccps_gar
;
224 if (between48(seqno
, lswl
, dp
->dccps_swh
) &&
225 (ackno
== DCCP_PKT_WITHOUT_ACK_SEQ
||
226 between48(ackno
, lawl
, dp
->dccps_awh
))) {
227 dccp_update_gsr(sk
, seqno
);
229 if (dh
->dccph_type
!= DCCP_PKT_SYNC
&&
230 (ackno
!= DCCP_PKT_WITHOUT_ACK_SEQ
))
231 dp
->dccps_gar
= ackno
;
233 unsigned long now
= jiffies
;
235 * Step 6: Check sequence numbers
237 * If P.type == Reset,
238 * Send Sync packet acknowledging S.GSR
240 * Send Sync packet acknowledging P.seqno
241 * Drop packet and return
243 * These Syncs are rate-limited as per RFC 4340, 7.5.4:
244 * at most 1 / (dccp_sync_rate_limit * HZ) Syncs per second.
246 if (time_before(now
, (dp
->dccps_rate_last
+
247 sysctl_dccp_sync_ratelimit
)))
250 DCCP_WARN("DCCP: Step 6 failed for %s packet, "
251 "(LSWL(%llu) <= P.seqno(%llu) <= S.SWH(%llu)) and "
252 "(P.ackno %s or LAWL(%llu) <= P.ackno(%llu) <= S.AWH(%llu), "
253 "sending SYNC...\n", dccp_packet_name(dh
->dccph_type
),
254 (unsigned long long) lswl
, (unsigned long long) seqno
,
255 (unsigned long long) dp
->dccps_swh
,
256 (ackno
== DCCP_PKT_WITHOUT_ACK_SEQ
) ? "doesn't exist"
258 (unsigned long long) lawl
, (unsigned long long) ackno
,
259 (unsigned long long) dp
->dccps_awh
);
261 dp
->dccps_rate_last
= now
;
263 if (dh
->dccph_type
== DCCP_PKT_RESET
)
264 seqno
= dp
->dccps_gsr
;
265 dccp_send_sync(sk
, seqno
, DCCP_PKT_SYNC
);
272 static int __dccp_rcv_established(struct sock
*sk
, struct sk_buff
*skb
,
273 const struct dccp_hdr
*dh
, const unsigned len
)
275 struct dccp_sock
*dp
= dccp_sk(sk
);
277 switch (dccp_hdr(skb
)->dccph_type
) {
278 case DCCP_PKT_DATAACK
:
281 * FIXME: schedule DATA_DROPPED (RFC 4340, 11.7.2) if and when
282 * - sk_shutdown == RCV_SHUTDOWN, use Code 1, "Not Listening"
283 * - sk_receive_queue is full, use Code 2, "Receive Buffer"
285 __skb_pull(skb
, dh
->dccph_doff
* 4);
286 __skb_queue_tail(&sk
->sk_receive_queue
, skb
);
287 skb_set_owner_r(skb
, sk
);
288 sk
->sk_data_ready(sk
, 0);
294 * Step 9: Process Reset
295 * If P.type == Reset,
296 * Tear down connection
297 * S.state := TIMEWAIT
299 * Drop packet and return
301 dccp_rcv_reset(sk
, skb
);
303 case DCCP_PKT_CLOSEREQ
:
304 if (dccp_rcv_closereq(sk
, skb
))
308 if (dccp_rcv_close(sk
, skb
))
311 case DCCP_PKT_REQUEST
:
313 * or (S.is_server and P.type == Response)
314 * or (S.is_client and P.type == Request)
315 * or (S.state >= OPEN and P.type == Request
316 * and P.seqno >= S.OSR)
317 * or (S.state >= OPEN and P.type == Response
318 * and P.seqno >= S.OSR)
319 * or (S.state == RESPOND and P.type == Data),
320 * Send Sync packet acknowledging P.seqno
321 * Drop packet and return
323 if (dp
->dccps_role
!= DCCP_ROLE_LISTEN
)
326 case DCCP_PKT_RESPONSE
:
327 if (dp
->dccps_role
!= DCCP_ROLE_CLIENT
)
330 if (dccp_delta_seqno(dp
->dccps_osr
,
331 DCCP_SKB_CB(skb
)->dccpd_seq
) >= 0) {
333 dccp_send_sync(sk
, DCCP_SKB_CB(skb
)->dccpd_seq
,
338 dccp_send_sync(sk
, DCCP_SKB_CB(skb
)->dccpd_seq
,
341 * From RFC 4340, sec. 5.7
343 * As with DCCP-Ack packets, DCCP-Sync and DCCP-SyncAck packets
344 * MAY have non-zero-length application data areas, whose
345 * contents receivers MUST ignore.
350 DCCP_INC_STATS_BH(DCCP_MIB_INERRS
);
356 int dccp_rcv_established(struct sock
*sk
, struct sk_buff
*skb
,
357 const struct dccp_hdr
*dh
, const unsigned len
)
359 struct dccp_sock
*dp
= dccp_sk(sk
);
361 if (dccp_check_seqno(sk
, skb
))
364 if (dccp_parse_options(sk
, skb
))
367 if (DCCP_SKB_CB(skb
)->dccpd_ack_seq
!= DCCP_PKT_WITHOUT_ACK_SEQ
)
368 dccp_event_ack_recv(sk
, skb
);
370 if (dccp_msk(sk
)->dccpms_send_ack_vector
&&
371 dccp_ackvec_add(dp
->dccps_hc_rx_ackvec
, sk
,
372 DCCP_SKB_CB(skb
)->dccpd_seq
,
373 DCCP_ACKVEC_STATE_RECEIVED
))
375 dccp_deliver_input_to_ccids(sk
, skb
);
377 return __dccp_rcv_established(sk
, skb
, dh
, len
);
383 EXPORT_SYMBOL_GPL(dccp_rcv_established
);
385 static int dccp_rcv_request_sent_state_process(struct sock
*sk
,
387 const struct dccp_hdr
*dh
,
391 * Step 4: Prepare sequence numbers in REQUEST
392 * If S.state == REQUEST,
393 * If (P.type == Response or P.type == Reset)
394 * and S.AWL <= P.ackno <= S.AWH,
395 * / * Set sequence number variables corresponding to the
396 * other endpoint, so P will pass the tests in Step 6 * /
397 * Set S.GSR, S.ISR, S.SWL, S.SWH
398 * / * Response processing continues in Step 10; Reset
399 * processing continues in Step 9 * /
401 if (dh
->dccph_type
== DCCP_PKT_RESPONSE
) {
402 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
403 struct dccp_sock
*dp
= dccp_sk(sk
);
404 long tstamp
= dccp_timestamp();
406 /* Stop the REQUEST timer */
407 inet_csk_clear_xmit_timer(sk
, ICSK_TIME_RETRANS
);
408 BUG_TRAP(sk
->sk_send_head
!= NULL
);
409 __kfree_skb(sk
->sk_send_head
);
410 sk
->sk_send_head
= NULL
;
412 if (!between48(DCCP_SKB_CB(skb
)->dccpd_ack_seq
,
413 dp
->dccps_awl
, dp
->dccps_awh
)) {
414 dccp_pr_debug("invalid ackno: S.AWL=%llu, "
415 "P.ackno=%llu, S.AWH=%llu \n",
416 (unsigned long long)dp
->dccps_awl
,
417 (unsigned long long)DCCP_SKB_CB(skb
)->dccpd_ack_seq
,
418 (unsigned long long)dp
->dccps_awh
);
419 goto out_invalid_packet
;
422 if (dccp_parse_options(sk
, skb
))
423 goto out_invalid_packet
;
425 /* Obtain usec RTT sample from SYN exchange (used by CCID 3) */
426 if (likely(dp
->dccps_options_received
.dccpor_timestamp_echo
))
427 dp
->dccps_syn_rtt
= dccp_sample_rtt(sk
, 10 * (tstamp
-
428 dp
->dccps_options_received
.dccpor_timestamp_echo
));
430 if (dccp_msk(sk
)->dccpms_send_ack_vector
&&
431 dccp_ackvec_add(dp
->dccps_hc_rx_ackvec
, sk
,
432 DCCP_SKB_CB(skb
)->dccpd_seq
,
433 DCCP_ACKVEC_STATE_RECEIVED
))
434 goto out_invalid_packet
; /* FIXME: change error code */
436 dp
->dccps_isr
= DCCP_SKB_CB(skb
)->dccpd_seq
;
437 dccp_update_gsr(sk
, dp
->dccps_isr
);
439 * SWL and AWL are initially adjusted so that they are not less than
440 * the initial Sequence Numbers received and sent, respectively:
441 * SWL := max(GSR + 1 - floor(W/4), ISR),
442 * AWL := max(GSS - W' + 1, ISS).
443 * These adjustments MUST be applied only at the beginning of the
446 * AWL was adjusted in dccp_v4_connect -acme
448 dccp_set_seqno(&dp
->dccps_swl
,
449 max48(dp
->dccps_swl
, dp
->dccps_isr
));
451 dccp_sync_mss(sk
, icsk
->icsk_pmtu_cookie
);
454 * Step 10: Process REQUEST state (second part)
455 * If S.state == REQUEST,
456 * / * If we get here, P is a valid Response from the
457 * server (see Step 4), and we should move to
458 * PARTOPEN state. PARTOPEN means send an Ack,
459 * don't send Data packets, retransmit Acks
460 * periodically, and always include any Init Cookie
461 * from the Response * /
462 * S.state := PARTOPEN
464 * Continue with S.state == PARTOPEN
465 * / * Step 12 will send the Ack completing the
466 * three-way handshake * /
468 dccp_set_state(sk
, DCCP_PARTOPEN
);
470 /* Make sure socket is routed, for correct metrics. */
471 icsk
->icsk_af_ops
->rebuild_header(sk
);
473 if (!sock_flag(sk
, SOCK_DEAD
)) {
474 sk
->sk_state_change(sk
);
475 sk_wake_async(sk
, SOCK_WAKE_IO
, POLL_OUT
);
478 if (sk
->sk_write_pending
|| icsk
->icsk_ack
.pingpong
||
479 icsk
->icsk_accept_queue
.rskq_defer_accept
) {
480 /* Save one ACK. Data will be ready after
481 * several ticks, if write_pending is set.
483 * It may be deleted, but with this feature tcpdumps
484 * look so _wonderfully_ clever, that I was not able
485 * to stand against the temptation 8) --ANK
488 * OK, in DCCP we can as well do a similar trick, its
489 * even in the draft, but there is no need for us to
490 * schedule an ack here, as dccp_sendmsg does this for
491 * us, also stated in the draft. -acme
501 /* dccp_v4_do_rcv will send a reset */
502 DCCP_SKB_CB(skb
)->dccpd_reset_code
= DCCP_RESET_CODE_PACKET_ERROR
;
506 static int dccp_rcv_respond_partopen_state_process(struct sock
*sk
,
508 const struct dccp_hdr
*dh
,
513 switch (dh
->dccph_type
) {
515 inet_csk_clear_xmit_timer(sk
, ICSK_TIME_DACK
);
518 if (sk
->sk_state
== DCCP_RESPOND
)
520 case DCCP_PKT_DATAACK
:
523 * FIXME: we should be reseting the PARTOPEN (DELACK) timer
524 * here but only if we haven't used the DELACK timer for
525 * something else, like sending a delayed ack for a TIMESTAMP
526 * echo, etc, for now were not clearing it, sending an extra
527 * ACK when there is nothing else to do in DELACK is not a big
531 /* Stop the PARTOPEN timer */
532 if (sk
->sk_state
== DCCP_PARTOPEN
)
533 inet_csk_clear_xmit_timer(sk
, ICSK_TIME_DACK
);
535 dccp_sk(sk
)->dccps_osr
= DCCP_SKB_CB(skb
)->dccpd_seq
;
536 dccp_set_state(sk
, DCCP_OPEN
);
538 if (dh
->dccph_type
== DCCP_PKT_DATAACK
||
539 dh
->dccph_type
== DCCP_PKT_DATA
) {
540 __dccp_rcv_established(sk
, skb
, dh
, len
);
541 queued
= 1; /* packet was queued
542 (by __dccp_rcv_established) */
550 int dccp_rcv_state_process(struct sock
*sk
, struct sk_buff
*skb
,
551 struct dccp_hdr
*dh
, unsigned len
)
553 struct dccp_sock
*dp
= dccp_sk(sk
);
554 struct dccp_skb_cb
*dcb
= DCCP_SKB_CB(skb
);
555 const int old_state
= sk
->sk_state
;
559 * Step 3: Process LISTEN state
561 * If S.state == LISTEN,
562 * If P.type == Request or P contains a valid Init Cookie option,
563 * (* Must scan the packet's options to check for Init
564 * Cookies. Only Init Cookies are processed here,
565 * however; other options are processed in Step 8. This
566 * scan need only be performed if the endpoint uses Init
568 * (* Generate a new socket and switch to that socket *)
569 * Set S := new socket for this port pair
571 * Choose S.ISS (initial seqno) or set from Init Cookies
572 * Initialize S.GAR := S.ISS
573 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init
574 * Cookies Continue with S.state == RESPOND
575 * (* A Response packet will be generated in Step 11 *)
577 * Generate Reset(No Connection) unless P.type == Reset
578 * Drop packet and return
580 if (sk
->sk_state
== DCCP_LISTEN
) {
581 if (dh
->dccph_type
== DCCP_PKT_REQUEST
) {
582 if (inet_csk(sk
)->icsk_af_ops
->conn_request(sk
,
586 /* FIXME: do congestion control initialization */
589 if (dh
->dccph_type
== DCCP_PKT_RESET
)
592 /* Caller (dccp_v4_do_rcv) will send Reset */
593 dcb
->dccpd_reset_code
= DCCP_RESET_CODE_NO_CONNECTION
;
597 if (sk
->sk_state
!= DCCP_REQUESTING
) {
598 if (dccp_check_seqno(sk
, skb
))
602 * Step 8: Process options and mark acknowledgeable
604 if (dccp_parse_options(sk
, skb
))
607 if (dcb
->dccpd_ack_seq
!= DCCP_PKT_WITHOUT_ACK_SEQ
)
608 dccp_event_ack_recv(sk
, skb
);
610 if (dccp_msk(sk
)->dccpms_send_ack_vector
&&
611 dccp_ackvec_add(dp
->dccps_hc_rx_ackvec
, sk
,
612 DCCP_SKB_CB(skb
)->dccpd_seq
,
613 DCCP_ACKVEC_STATE_RECEIVED
))
616 dccp_deliver_input_to_ccids(sk
, skb
);
620 * Step 9: Process Reset
621 * If P.type == Reset,
622 * Tear down connection
623 * S.state := TIMEWAIT
625 * Drop packet and return
627 if (dh
->dccph_type
== DCCP_PKT_RESET
) {
628 dccp_rcv_reset(sk
, skb
);
631 * Step 7: Check for unexpected packet types
632 * If (S.is_server and P.type == Response)
633 * or (S.is_client and P.type == Request)
634 * or (S.state == RESPOND and P.type == Data),
635 * Send Sync packet acknowledging P.seqno
636 * Drop packet and return
638 } else if ((dp
->dccps_role
!= DCCP_ROLE_CLIENT
&&
639 dh
->dccph_type
== DCCP_PKT_RESPONSE
) ||
640 (dp
->dccps_role
== DCCP_ROLE_CLIENT
&&
641 dh
->dccph_type
== DCCP_PKT_REQUEST
) ||
642 (sk
->sk_state
== DCCP_RESPOND
&&
643 dh
->dccph_type
== DCCP_PKT_DATA
)) {
644 dccp_send_sync(sk
, dcb
->dccpd_seq
, DCCP_PKT_SYNC
);
646 } else if (dh
->dccph_type
== DCCP_PKT_CLOSEREQ
) {
647 if (dccp_rcv_closereq(sk
, skb
))
650 } else if (dh
->dccph_type
== DCCP_PKT_CLOSE
) {
651 if (dccp_rcv_close(sk
, skb
))
656 switch (sk
->sk_state
) {
658 dcb
->dccpd_reset_code
= DCCP_RESET_CODE_NO_CONNECTION
;
661 case DCCP_REQUESTING
:
662 /* FIXME: do congestion control initialization */
664 queued
= dccp_rcv_request_sent_state_process(sk
, skb
, dh
, len
);
673 queued
= dccp_rcv_respond_partopen_state_process(sk
, skb
,
678 if (dh
->dccph_type
== DCCP_PKT_ACK
||
679 dh
->dccph_type
== DCCP_PKT_DATAACK
) {
682 sk
->sk_state_change(sk
);
683 sk_wake_async(sk
, SOCK_WAKE_IO
, POLL_OUT
);
686 } else if (unlikely(dh
->dccph_type
== DCCP_PKT_SYNC
)) {
687 dccp_send_sync(sk
, dcb
->dccpd_seq
, DCCP_PKT_SYNCACK
);
698 EXPORT_SYMBOL_GPL(dccp_rcv_state_process
);
701 * dccp_sample_rtt - Validate and finalise computation of RTT sample
702 * @delta: number of microseconds between packet and acknowledgment
703 * The routine is kept generic to work in different contexts. It should be
704 * called immediately when the ACK used for the RTT sample arrives.
706 u32
dccp_sample_rtt(struct sock
*sk
, long delta
)
708 /* dccpor_elapsed_time is either zeroed out or set and > 0 */
709 delta
-= dccp_sk(sk
)->dccps_options_received
.dccpor_elapsed_time
* 10;
711 if (unlikely(delta
<= 0)) {
712 DCCP_WARN("unusable RTT sample %ld, using min\n", delta
);
713 return DCCP_SANE_RTT_MIN
;
715 if (unlikely(delta
> DCCP_SANE_RTT_MAX
)) {
716 DCCP_WARN("RTT sample %ld too large, using max\n", delta
);
717 return DCCP_SANE_RTT_MAX
;
723 EXPORT_SYMBOL_GPL(dccp_sample_rtt
);