4 * An implementation of the DCCP protocol
5 * Copyright (c) 2005 Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org>
6 * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
7 * Copyright (c) 2005 Ian McDonald <iam4@cs.waikato.ac.nz>
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * as published by the Free Software Foundation; either version
12 * 2 of the License, or (at your option) any later version.
14 #include <linux/config.h>
15 #include <linux/dccp.h>
16 #include <linux/module.h>
17 #include <linux/types.h>
18 #include <linux/kernel.h>
19 #include <linux/skbuff.h>
24 static void dccp_ackpkts_check_rcv_ackvector(struct dccp_ackpkts
*ap
,
27 const unsigned char len
,
28 const unsigned char *vector
);
30 /* stores the default values for new connection. may be changed with sysctl */
31 static const struct dccp_options dccpo_default_values
= {
32 .dccpo_sequence_window
= DCCPF_INITIAL_SEQUENCE_WINDOW
,
33 .dccpo_ccid
= DCCPF_INITIAL_CCID
,
34 .dccpo_send_ack_vector
= DCCPF_INITIAL_SEND_ACK_VECTOR
,
35 .dccpo_send_ndp_count
= DCCPF_INITIAL_SEND_NDP_COUNT
,
38 void dccp_options_init(struct dccp_options
*dccpo
)
40 memcpy(dccpo
, &dccpo_default_values
, sizeof(*dccpo
));
43 static u32
dccp_decode_value_var(const unsigned char *bf
, const u8 len
)
59 int dccp_parse_options(struct sock
*sk
, struct sk_buff
*skb
)
61 struct dccp_sock
*dp
= dccp_sk(sk
);
62 #ifdef CONFIG_IP_DCCP_DEBUG
63 const char *debug_prefix
= dp
->dccps_role
== DCCP_ROLE_CLIENT
?
64 "CLIENT rx opt: " : "server rx opt: ";
66 const struct dccp_hdr
*dh
= dccp_hdr(skb
);
67 const u8 pkt_type
= DCCP_SKB_CB(skb
)->dccpd_type
;
68 unsigned char *options
= (unsigned char *)dh
+ dccp_hdr_len(skb
);
69 unsigned char *opt_ptr
= options
;
70 const unsigned char *opt_end
= (unsigned char *)dh
+
72 struct dccp_options_received
*opt_recv
= &dp
->dccps_options_received
;
73 unsigned char opt
, len
;
77 memset(opt_recv
, 0, sizeof(*opt_recv
));
79 while (opt_ptr
!= opt_end
) {
84 /* Check if this isn't a single byte option */
85 if (opt
> DCCPO_MAX_RESERVED
) {
86 if (opt_ptr
== opt_end
)
87 goto out_invalid_option
;
91 goto out_invalid_option
;
93 * Remove the type and len fields, leaving
100 if (opt_ptr
> opt_end
)
101 goto out_invalid_option
;
107 case DCCPO_NDP_COUNT
:
109 goto out_invalid_option
;
111 opt_recv
->dccpor_ndp
= dccp_decode_value_var(value
, len
);
112 dccp_pr_debug("%sNDP count=%d\n", debug_prefix
,
113 opt_recv
->dccpor_ndp
);
115 case DCCPO_ACK_VECTOR_0
:
116 if (len
> DCCP_MAX_ACK_VECTOR_LEN
)
117 goto out_invalid_option
;
119 if (pkt_type
== DCCP_PKT_DATA
)
122 opt_recv
->dccpor_ack_vector_len
= len
;
123 opt_recv
->dccpor_ack_vector_idx
= value
- options
;
125 dccp_pr_debug("%sACK vector 0, len=%d, ack_ackno=%llu\n",
128 DCCP_SKB_CB(skb
)->dccpd_ack_seq
);
129 dccp_ackvector_print(DCCP_SKB_CB(skb
)->dccpd_ack_seq
,
131 dccp_ackpkts_check_rcv_ackvector(dp
->dccps_hc_rx_ackpkts
,
133 DCCP_SKB_CB(skb
)->dccpd_ack_seq
,
136 case DCCPO_TIMESTAMP
:
138 goto out_invalid_option
;
140 opt_recv
->dccpor_timestamp
= ntohl(*(u32
*)value
);
142 dp
->dccps_timestamp_echo
= opt_recv
->dccpor_timestamp
;
143 dccp_timestamp(sk
, &dp
->dccps_timestamp_time
);
145 dccp_pr_debug("%sTIMESTAMP=%u, ackno=%llu\n",
146 debug_prefix
, opt_recv
->dccpor_timestamp
,
148 DCCP_SKB_CB(skb
)->dccpd_ack_seq
);
150 case DCCPO_TIMESTAMP_ECHO
:
151 if (len
!= 4 && len
!= 6 && len
!= 8)
152 goto out_invalid_option
;
154 opt_recv
->dccpor_timestamp_echo
= ntohl(*(u32
*)value
);
156 dccp_pr_debug("%sTIMESTAMP_ECHO=%u, len=%d, ackno=%llu, ",
158 opt_recv
->dccpor_timestamp_echo
,
161 DCCP_SKB_CB(skb
)->dccpd_ack_seq
);
168 elapsed_time
= ntohs(*(u16
*)(value
+ 4));
170 elapsed_time
= ntohl(*(u32
*)(value
+ 4));
172 /* Give precedence to the biggest ELAPSED_TIME */
173 if (elapsed_time
> opt_recv
->dccpor_elapsed_time
)
174 opt_recv
->dccpor_elapsed_time
= elapsed_time
;
176 case DCCPO_ELAPSED_TIME
:
177 if (len
!= 2 && len
!= 4)
178 goto out_invalid_option
;
180 if (pkt_type
== DCCP_PKT_DATA
)
184 elapsed_time
= ntohs(*(u16
*)value
);
186 elapsed_time
= ntohl(*(u32
*)value
);
188 if (elapsed_time
> opt_recv
->dccpor_elapsed_time
)
189 opt_recv
->dccpor_elapsed_time
= elapsed_time
;
191 dccp_pr_debug("%sELAPSED_TIME=%d\n", debug_prefix
,
195 * From draft-ietf-dccp-spec-11.txt:
197 * Option numbers 128 through 191 are for
198 * options sent from the HC-Sender to the
199 * HC-Receiver; option numbers 192 through 255
200 * are for options sent from the HC-Receiver to
204 const u16 idx
= value
- options
;
206 if (ccid_hc_rx_parse_options(dp
->dccps_hc_rx_ccid
, sk
,
209 goto out_invalid_option
;
213 const u16 idx
= value
- options
;
215 if (ccid_hc_tx_parse_options(dp
->dccps_hc_tx_ccid
, sk
,
218 goto out_invalid_option
;
222 pr_info("DCCP(%p): option %d(len=%d) not "
223 "implemented, ignoring\n",
232 DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT
);
233 DCCP_SKB_CB(skb
)->dccpd_reset_code
= DCCP_RESET_CODE_OPTION_ERROR
;
234 pr_info("DCCP(%p): invalid option %d, len=%d\n", sk
, opt
, len
);
238 static void dccp_encode_value_var(const u32 value
, unsigned char *to
,
239 const unsigned int len
)
242 *to
++ = (value
& 0xFF000000) >> 24;
244 *to
++ = (value
& 0xFF0000) >> 16;
246 *to
++ = (value
& 0xFF00) >> 8;
248 *to
++ = (value
& 0xFF);
251 static inline int dccp_ndp_len(const int ndp
)
253 return likely(ndp
<= 0xFF) ? 1 : ndp
<= 0xFFFF ? 2 : 3;
256 void dccp_insert_option(struct sock
*sk
, struct sk_buff
*skb
,
257 const unsigned char option
,
258 const void *value
, const unsigned char len
)
262 if (DCCP_SKB_CB(skb
)->dccpd_opt_len
+ len
+ 2 > DCCP_MAX_OPT_LEN
) {
263 LIMIT_NETDEBUG(KERN_INFO
"DCCP: packet too small to insert "
264 "%d option!\n", option
);
268 DCCP_SKB_CB(skb
)->dccpd_opt_len
+= len
+ 2;
270 to
= skb_push(skb
, len
+ 2);
274 memcpy(to
, value
, len
);
277 EXPORT_SYMBOL_GPL(dccp_insert_option
);
279 static void dccp_insert_option_ndp(struct sock
*sk
, struct sk_buff
*skb
)
281 struct dccp_sock
*dp
= dccp_sk(sk
);
282 int ndp
= dp
->dccps_ndp_count
;
284 if (dccp_non_data_packet(skb
))
285 ++dp
->dccps_ndp_count
;
287 dp
->dccps_ndp_count
= 0;
291 const int ndp_len
= dccp_ndp_len(ndp
);
292 const int len
= ndp_len
+ 2;
294 if (DCCP_SKB_CB(skb
)->dccpd_opt_len
+ len
> DCCP_MAX_OPT_LEN
)
297 DCCP_SKB_CB(skb
)->dccpd_opt_len
+= len
;
299 ptr
= skb_push(skb
, len
);
300 *ptr
++ = DCCPO_NDP_COUNT
;
302 dccp_encode_value_var(ndp
, ptr
, ndp_len
);
306 static inline int dccp_elapsed_time_len(const u32 elapsed_time
)
308 return elapsed_time
== 0 ? 0 : elapsed_time
<= 0xFFFF ? 2 : 4;
311 void dccp_insert_option_elapsed_time(struct sock
*sk
,
315 #ifdef CONFIG_IP_DCCP_DEBUG
316 struct dccp_sock
*dp
= dccp_sk(sk
);
317 const char *debug_prefix
= dp
->dccps_role
== DCCP_ROLE_CLIENT
?
318 "CLIENT TX opt: " : "server TX opt: ";
320 const int elapsed_time_len
= dccp_elapsed_time_len(elapsed_time
);
321 const int len
= 2 + elapsed_time_len
;
324 if (elapsed_time_len
== 0)
327 if (DCCP_SKB_CB(skb
)->dccpd_opt_len
+ len
> DCCP_MAX_OPT_LEN
) {
328 LIMIT_NETDEBUG(KERN_INFO
"DCCP: packet too small to "
329 "insert elapsed time!\n");
333 DCCP_SKB_CB(skb
)->dccpd_opt_len
+= len
;
335 to
= skb_push(skb
, len
);
336 *to
++ = DCCPO_ELAPSED_TIME
;
339 if (elapsed_time_len
== 2) {
340 const u16 var16
= htons((u16
)elapsed_time
);
341 memcpy(to
, &var16
, 2);
343 const u32 var32
= htonl(elapsed_time
);
344 memcpy(to
, &var32
, 4);
347 dccp_pr_debug("%sELAPSED_TIME=%u, len=%d, seqno=%llu\n",
348 debug_prefix
, elapsed_time
,
350 (unsigned long long) DCCP_SKB_CB(skb
)->dccpd_seq
);
353 EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time
);
355 static void dccp_insert_option_ack_vector(struct sock
*sk
, struct sk_buff
*skb
)
357 struct dccp_sock
*dp
= dccp_sk(sk
);
358 #ifdef CONFIG_IP_DCCP_DEBUG
359 const char *debug_prefix
= dp
->dccps_role
== DCCP_ROLE_CLIENT
?
360 "CLIENT TX opt: " : "server TX opt: ";
362 struct dccp_ackpkts
*ap
= dp
->dccps_hc_rx_ackpkts
;
363 int len
= ap
->dccpap_buf_vector_len
+ 2;
366 unsigned char *to
, *from
;
368 dccp_timestamp(sk
, &now
);
369 elapsed_time
= timeval_delta(&now
, &ap
->dccpap_time
) / 10;
371 if (elapsed_time
!= 0)
372 dccp_insert_option_elapsed_time(sk
, skb
, elapsed_time
);
374 if (DCCP_SKB_CB(skb
)->dccpd_opt_len
+ len
> DCCP_MAX_OPT_LEN
) {
375 LIMIT_NETDEBUG(KERN_INFO
"DCCP: packet too small to "
376 "insert ACK Vector!\n");
381 * XXX: now we have just one ack vector sent record, so
382 * we have to wait for it to be cleared.
384 * Of course this is not acceptable, but this is just for
387 if (ap
->dccpap_ack_seqno
!= DCCP_MAX_SEQNO
+ 1)
390 DCCP_SKB_CB(skb
)->dccpd_opt_len
+= len
;
392 to
= skb_push(skb
, len
);
393 *to
++ = DCCPO_ACK_VECTOR_0
;
396 len
= ap
->dccpap_buf_vector_len
;
397 from
= ap
->dccpap_buf
+ ap
->dccpap_buf_head
;
399 /* Check if buf_head wraps */
400 if (ap
->dccpap_buf_head
+ len
> ap
->dccpap_buf_len
) {
401 const unsigned int tailsize
= (ap
->dccpap_buf_len
-
402 ap
->dccpap_buf_head
);
404 memcpy(to
, from
, tailsize
);
407 from
= ap
->dccpap_buf
;
410 memcpy(to
, from
, len
);
412 * From draft-ietf-dccp-spec-11.txt:
414 * For each acknowledgement it sends, the HC-Receiver will add an
415 * acknowledgement record. ack_seqno will equal the HC-Receiver
416 * sequence number it used for the ack packet; ack_ptr will equal
417 * buf_head; ack_ackno will equal buf_ackno; and ack_nonce will
420 * This implemention uses just one ack record for now.
422 ap
->dccpap_ack_seqno
= DCCP_SKB_CB(skb
)->dccpd_seq
;
423 ap
->dccpap_ack_ptr
= ap
->dccpap_buf_head
;
424 ap
->dccpap_ack_ackno
= ap
->dccpap_buf_ackno
;
425 ap
->dccpap_ack_nonce
= ap
->dccpap_buf_nonce
;
426 ap
->dccpap_ack_vector_len
= ap
->dccpap_buf_vector_len
;
428 dccp_pr_debug("%sACK Vector 0, len=%d, ack_seqno=%llu, "
430 debug_prefix
, ap
->dccpap_ack_vector_len
,
431 (unsigned long long) ap
->dccpap_ack_seqno
,
432 (unsigned long long) ap
->dccpap_ack_ackno
);
435 void dccp_timestamp(const struct sock
*sk
, struct timeval
*tv
)
437 const struct dccp_sock
*dp
= dccp_sk(sk
);
440 tv
->tv_sec
-= dp
->dccps_epoch
.tv_sec
;
441 tv
->tv_usec
-= dp
->dccps_epoch
.tv_usec
;
443 while (tv
->tv_usec
< 0) {
445 tv
->tv_usec
+= USEC_PER_SEC
;
449 EXPORT_SYMBOL_GPL(dccp_timestamp
);
451 void dccp_insert_option_timestamp(struct sock
*sk
, struct sk_buff
*skb
)
456 dccp_timestamp(sk
, &tv
);
457 now
= timeval_usecs(&tv
) / 10;
458 /* yes this will overflow but that is the point as we want a
459 * 10 usec 32 bit timer which mean it wraps every 11.9 hours */
462 dccp_insert_option(sk
, skb
, DCCPO_TIMESTAMP
, &now
, sizeof(now
));
465 EXPORT_SYMBOL_GPL(dccp_insert_option_timestamp
);
467 static void dccp_insert_option_timestamp_echo(struct sock
*sk
,
470 struct dccp_sock
*dp
= dccp_sk(sk
);
471 #ifdef CONFIG_IP_DCCP_DEBUG
472 const char *debug_prefix
= dp
->dccps_role
== DCCP_ROLE_CLIENT
?
473 "CLIENT TX opt: " : "server TX opt: ";
478 int len
, elapsed_time_len
;
481 dccp_timestamp(sk
, &now
);
482 elapsed_time
= timeval_delta(&now
, &dp
->dccps_timestamp_time
) / 10;
483 elapsed_time_len
= dccp_elapsed_time_len(elapsed_time
);
484 len
= 6 + elapsed_time_len
;
486 if (DCCP_SKB_CB(skb
)->dccpd_opt_len
+ len
> DCCP_MAX_OPT_LEN
) {
487 LIMIT_NETDEBUG(KERN_INFO
"DCCP: packet too small to insert "
488 "timestamp echo!\n");
492 DCCP_SKB_CB(skb
)->dccpd_opt_len
+= len
;
494 to
= skb_push(skb
, len
);
495 *to
++ = DCCPO_TIMESTAMP_ECHO
;
498 tstamp_echo
= htonl(dp
->dccps_timestamp_echo
);
499 memcpy(to
, &tstamp_echo
, 4);
502 if (elapsed_time_len
== 2) {
503 const u16 var16
= htons((u16
)elapsed_time
);
504 memcpy(to
, &var16
, 2);
505 } else if (elapsed_time_len
== 4) {
506 const u32 var32
= htonl(elapsed_time
);
507 memcpy(to
, &var32
, 4);
510 dccp_pr_debug("%sTIMESTAMP_ECHO=%u, len=%d, seqno=%llu\n",
511 debug_prefix
, dp
->dccps_timestamp_echo
,
513 (unsigned long long) DCCP_SKB_CB(skb
)->dccpd_seq
);
515 dp
->dccps_timestamp_echo
= 0;
516 dp
->dccps_timestamp_time
.tv_sec
= 0;
517 dp
->dccps_timestamp_time
.tv_usec
= 0;
520 void dccp_insert_options(struct sock
*sk
, struct sk_buff
*skb
)
522 struct dccp_sock
*dp
= dccp_sk(sk
);
524 DCCP_SKB_CB(skb
)->dccpd_opt_len
= 0;
526 if (dp
->dccps_options
.dccpo_send_ndp_count
)
527 dccp_insert_option_ndp(sk
, skb
);
529 if (!dccp_packet_without_ack(skb
)) {
530 if (dp
->dccps_options
.dccpo_send_ack_vector
&&
531 (dp
->dccps_hc_rx_ackpkts
->dccpap_buf_ackno
!=
533 dccp_insert_option_ack_vector(sk
, skb
);
534 if (dp
->dccps_timestamp_echo
!= 0)
535 dccp_insert_option_timestamp_echo(sk
, skb
);
538 if (dp
->dccps_hc_rx_insert_options
) {
539 ccid_hc_rx_insert_options(dp
->dccps_hc_rx_ccid
, sk
, skb
);
540 dp
->dccps_hc_rx_insert_options
= 0;
542 if (dp
->dccps_hc_tx_insert_options
) {
543 ccid_hc_tx_insert_options(dp
->dccps_hc_tx_ccid
, sk
, skb
);
544 dp
->dccps_hc_tx_insert_options
= 0;
547 /* XXX: insert other options when appropriate */
549 if (DCCP_SKB_CB(skb
)->dccpd_opt_len
!= 0) {
550 /* The length of all options has to be a multiple of 4 */
551 int padding
= DCCP_SKB_CB(skb
)->dccpd_opt_len
% 4;
554 padding
= 4 - padding
;
555 memset(skb_push(skb
, padding
), 0, padding
);
556 DCCP_SKB_CB(skb
)->dccpd_opt_len
+= padding
;
561 struct dccp_ackpkts
*dccp_ackpkts_alloc(const unsigned int len
,
562 const unsigned int __nocast priority
)
564 struct dccp_ackpkts
*ap
= kmalloc(sizeof(*ap
) + len
, priority
);
567 #ifdef CONFIG_IP_DCCP_DEBUG
568 memset(ap
->dccpap_buf
, 0xFF, len
);
570 ap
->dccpap_buf_len
= len
;
571 ap
->dccpap_buf_head
=
572 ap
->dccpap_buf_tail
=
573 ap
->dccpap_buf_len
- 1;
574 ap
->dccpap_buf_ackno
=
575 ap
->dccpap_ack_ackno
=
576 ap
->dccpap_ack_seqno
= DCCP_MAX_SEQNO
+ 1;
577 ap
->dccpap_buf_nonce
= ap
->dccpap_buf_nonce
= 0;
578 ap
->dccpap_ack_ptr
= 0;
579 ap
->dccpap_time
.tv_sec
= 0;
580 ap
->dccpap_time
.tv_usec
= 0;
581 ap
->dccpap_buf_vector_len
= ap
->dccpap_ack_vector_len
= 0;
587 void dccp_ackpkts_free(struct dccp_ackpkts
*ap
)
590 #ifdef CONFIG_IP_DCCP_DEBUG
591 memset(ap
, 0xFF, sizeof(*ap
) + ap
->dccpap_buf_len
);
597 static inline u8
dccp_ackpkts_state(const struct dccp_ackpkts
*ap
,
598 const unsigned int index
)
600 return ap
->dccpap_buf
[index
] & DCCP_ACKPKTS_STATE_MASK
;
603 static inline u8
dccp_ackpkts_len(const struct dccp_ackpkts
*ap
,
604 const unsigned int index
)
606 return ap
->dccpap_buf
[index
] & DCCP_ACKPKTS_LEN_MASK
;
610 * If several packets are missing, the HC-Receiver may prefer to enter multiple
611 * bytes with run length 0, rather than a single byte with a larger run length;
612 * this simplifies table updates if one of the missing packets arrives.
614 static inline int dccp_ackpkts_set_buf_head_state(struct dccp_ackpkts
*ap
,
615 const unsigned int packets
,
616 const unsigned char state
)
619 signed long new_head
;
621 if (ap
->dccpap_buf_vector_len
+ packets
> ap
->dccpap_buf_len
)
625 new_head
= ap
->dccpap_buf_head
- packets
;
629 memset(ap
->dccpap_buf
, DCCP_ACKPKTS_STATE_NOT_RECEIVED
,
633 new_head
+= ap
->dccpap_buf_len
;
636 ap
->dccpap_buf_head
= new_head
;
639 memset(ap
->dccpap_buf
+ ap
->dccpap_buf_head
+ 1,
640 DCCP_ACKPKTS_STATE_NOT_RECEIVED
, gap
);
642 ap
->dccpap_buf
[ap
->dccpap_buf_head
] = state
;
643 ap
->dccpap_buf_vector_len
+= packets
;
648 * Implements the draft-ietf-dccp-spec-11.txt Appendix A
650 int dccp_ackpkts_add(struct dccp_ackpkts
*ap
, const struct sock
*sk
,
654 * Check at the right places if the buffer is full, if it is, tell the
655 * caller to start dropping packets till the HC-Sender acks our ACK
656 * vectors, when we will free up space in dccpap_buf.
658 * We may well decide to do buffer compression, etc, but for now lets
663 * Of course, the circular buffer may overflow, either when the
664 * HC-Sender is sending data at a very high rate, when the
665 * HC-Receiver's acknowledgements are not reaching the HC-Sender,
666 * or when the HC-Sender is forgetting to acknowledge those acks
667 * (so the HC-Receiver is unable to clean up old state). In this
668 * case, the HC-Receiver should either compress the buffer (by
669 * increasing run lengths when possible), transfer its state to
670 * a larger buffer, or, as a last resort, drop all received
671 * packets, without processing them whatsoever, until its buffer
675 /* See if this is the first ackno being inserted */
676 if (ap
->dccpap_buf_vector_len
== 0) {
677 ap
->dccpap_buf
[ap
->dccpap_buf_head
] = state
;
678 ap
->dccpap_buf_vector_len
= 1;
679 } else if (after48(ackno
, ap
->dccpap_buf_ackno
)) {
680 const u64 delta
= dccp_delta_seqno(ap
->dccpap_buf_ackno
,
684 * Look if the state of this packet is the same as the
685 * previous ackno and if so if we can bump the head len.
688 dccp_ackpkts_state(ap
, ap
->dccpap_buf_head
) == state
&&
689 (dccp_ackpkts_len(ap
, ap
->dccpap_buf_head
) <
690 DCCP_ACKPKTS_LEN_MASK
))
691 ap
->dccpap_buf
[ap
->dccpap_buf_head
]++;
692 else if (dccp_ackpkts_set_buf_head_state(ap
, delta
, state
))
698 * When a packet with Sequence Number S arrives, and
699 * S <= buf_ackno, the HC-Receiver will scan the table
700 * for the byte corresponding to S. (Indexing structures
701 * could reduce the complexity of this scan.)
703 u64 delta
= dccp_delta_seqno(ackno
, ap
->dccpap_buf_ackno
);
704 unsigned int index
= ap
->dccpap_buf_head
;
707 const u8 len
= dccp_ackpkts_len(ap
, index
);
708 const u8 state
= dccp_ackpkts_state(ap
, index
);
710 * valid packets not yet in dccpap_buf have a reserved
711 * entry, with a len equal to 0.
713 if (state
== DCCP_ACKPKTS_STATE_NOT_RECEIVED
&&
714 len
== 0 && delta
== 0) { /* Found our
716 dccp_pr_debug("Found %llu reserved seat!\n",
717 (unsigned long long) ackno
);
718 ap
->dccpap_buf
[index
] = state
;
721 /* len == 0 means one packet */
726 if (++index
== ap
->dccpap_buf_len
)
731 ap
->dccpap_buf_ackno
= ackno
;
732 dccp_timestamp(sk
, &ap
->dccpap_time
);
735 dccp_ackpkts_print(ap
);
739 /* Duplicate packet */
740 dccp_pr_debug("Received a dup or already considered lost "
741 "packet: %llu\n", (unsigned long long) ackno
);
745 #ifdef CONFIG_IP_DCCP_DEBUG
746 void dccp_ackvector_print(const u64 ackno
, const unsigned char *vector
,
752 printk("ACK vector len=%d, ackno=%llu |", len
,
753 (unsigned long long) ackno
);
756 const u8 state
= (*vector
& DCCP_ACKPKTS_STATE_MASK
) >> 6;
757 const u8 rl
= (*vector
& DCCP_ACKPKTS_LEN_MASK
);
759 printk("%d,%d|", state
, rl
);
766 void dccp_ackpkts_print(const struct dccp_ackpkts
*ap
)
768 dccp_ackvector_print(ap
->dccpap_buf_ackno
,
769 ap
->dccpap_buf
+ ap
->dccpap_buf_head
,
770 ap
->dccpap_buf_vector_len
);
774 static void dccp_ackpkts_trow_away_ack_record(struct dccp_ackpkts
*ap
)
777 * As we're keeping track of the ack vector size
778 * (dccpap_buf_vector_len) and the sent ack vector size
779 * (dccpap_ack_vector_len) we don't need dccpap_buf_tail at all, but
780 * keep this code here as in the future we'll implement a vector of
781 * ack records, as suggested in draft-ietf-dccp-spec-11.txt
785 ap
->dccpap_buf_tail
= ap
->dccpap_ack_ptr
+ 1;
786 if (ap
->dccpap_buf_tail
>= ap
->dccpap_buf_len
)
787 ap
->dccpap_buf_tail
-= ap
->dccpap_buf_len
;
789 ap
->dccpap_buf_vector_len
-= ap
->dccpap_ack_vector_len
;
792 void dccp_ackpkts_check_rcv_ackno(struct dccp_ackpkts
*ap
, struct sock
*sk
,
795 /* Check if we actually sent an ACK vector */
796 if (ap
->dccpap_ack_seqno
== DCCP_MAX_SEQNO
+ 1)
799 if (ackno
== ap
->dccpap_ack_seqno
) {
800 #ifdef CONFIG_IP_DCCP_DEBUG
801 struct dccp_sock
*dp
= dccp_sk(sk
);
802 const char *debug_prefix
= dp
->dccps_role
== DCCP_ROLE_CLIENT
?
803 "CLIENT rx ack: " : "server rx ack: ";
805 dccp_pr_debug("%sACK packet 0, len=%d, ack_seqno=%llu, "
806 "ack_ackno=%llu, ACKED!\n",
808 (unsigned long long) ap
->dccpap_ack_seqno
,
809 (unsigned long long) ap
->dccpap_ack_ackno
);
810 dccp_ackpkts_trow_away_ack_record(ap
);
811 ap
->dccpap_ack_seqno
= DCCP_MAX_SEQNO
+ 1;
815 static void dccp_ackpkts_check_rcv_ackvector(struct dccp_ackpkts
*ap
,
816 struct sock
*sk
, u64 ackno
,
817 const unsigned char len
,
818 const unsigned char *vector
)
822 /* Check if we actually sent an ACK vector */
823 if (ap
->dccpap_ack_seqno
== DCCP_MAX_SEQNO
+ 1)
826 * We're in the receiver half connection, so if the received an ACK
827 * vector ackno (e.g. 50) before dccpap_ack_seqno (e.g. 52), we're
830 * Extra explanation with example:
832 * if we received an ACK vector with ackno 50, it can only be acking
833 * 50, 49, 48, etc, not 52 (the seqno for the ACK vector we sent).
835 /* dccp_pr_debug("is %llu < %llu? ", ackno, ap->dccpap_ack_seqno); */
836 if (before48(ackno
, ap
->dccpap_ack_seqno
)) {
837 /* dccp_pr_debug_cat("yes\n"); */
840 /* dccp_pr_debug_cat("no\n"); */
844 const u8 rl
= (*vector
& DCCP_ACKPKTS_LEN_MASK
);
847 dccp_set_seqno(&ackno_end_rl
, ackno
- rl
);
850 * dccp_pr_debug("is %llu <= %llu <= %llu? ", ackno_end_rl,
851 * ap->dccpap_ack_seqno, ackno);
853 if (between48(ap
->dccpap_ack_seqno
, ackno_end_rl
, ackno
)) {
854 const u8 state
= (*vector
&
855 DCCP_ACKPKTS_STATE_MASK
) >> 6;
856 /* dccp_pr_debug_cat("yes\n"); */
858 if (state
!= DCCP_ACKPKTS_STATE_NOT_RECEIVED
) {
859 #ifdef CONFIG_IP_DCCP_DEBUG
860 struct dccp_sock
*dp
= dccp_sk(sk
);
861 const char *debug_prefix
=
862 dp
->dccps_role
== DCCP_ROLE_CLIENT
?
863 "CLIENT rx ack: " : "server rx ack: ";
865 dccp_pr_debug("%sACK vector 0, len=%d, "
866 "ack_seqno=%llu, ack_ackno=%llu, "
870 ap
->dccpap_ack_seqno
,
872 ap
->dccpap_ack_ackno
);
873 dccp_ackpkts_trow_away_ack_record(ap
);
876 * If dccpap_ack_seqno was not received, no problem
877 * we'll send another ACK vector.
879 ap
->dccpap_ack_seqno
= DCCP_MAX_SEQNO
+ 1;
882 /* dccp_pr_debug_cat("no\n"); */
884 dccp_set_seqno(&ackno
, ackno_end_rl
- 1);