4 * An implementation of the DCCP protocol
5 * Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org>
6 * Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
13 #include <linux/config.h>
14 #include <linux/dccp.h>
15 #include <linux/module.h>
16 #include <linux/types.h>
17 #include <linux/kernel.h>
18 #include <linux/skbuff.h>
23 static void dccp_ackpkts_check_rcv_ackvector(struct dccp_ackpkts
*ap
,
26 const unsigned char len
,
27 const unsigned char *vector
);
29 /* stores the default values for new connection. may be changed with sysctl */
30 static const struct dccp_options dccpo_default_values
= {
31 .dccpo_sequence_window
= DCCPF_INITIAL_SEQUENCE_WINDOW
,
32 .dccpo_ccid
= DCCPF_INITIAL_CCID
,
33 .dccpo_send_ack_vector
= DCCPF_INITIAL_SEND_ACK_VECTOR
,
34 .dccpo_send_ndp_count
= DCCPF_INITIAL_SEND_NDP_COUNT
,
37 void dccp_options_init(struct dccp_options
*dccpo
)
39 memcpy(dccpo
, &dccpo_default_values
, sizeof(*dccpo
));
42 static u32
dccp_decode_value_var(const unsigned char *bf
, const u8 len
)
58 int dccp_parse_options(struct sock
*sk
, struct sk_buff
*skb
)
60 struct dccp_sock
*dp
= dccp_sk(sk
);
61 #ifdef CONFIG_IP_DCCP_DEBUG
62 const char *debug_prefix
= dp
->dccps_role
== DCCP_ROLE_CLIENT
?
63 "CLIENT rx opt: " : "server rx opt: ";
65 const struct dccp_hdr
*dh
= dccp_hdr(skb
);
66 const u8 pkt_type
= DCCP_SKB_CB(skb
)->dccpd_type
;
67 unsigned char *options
= (unsigned char *)dh
+ dccp_hdr_len(skb
);
68 unsigned char *opt_ptr
= options
;
69 const unsigned char *opt_end
= (unsigned char *)dh
+
71 struct dccp_options_received
*opt_recv
= &dp
->dccps_options_received
;
72 unsigned char opt
, len
;
75 memset(opt_recv
, 0, sizeof(*opt_recv
));
77 while (opt_ptr
!= opt_end
) {
82 /* Check if this isn't a single byte option */
83 if (opt
> DCCPO_MAX_RESERVED
) {
84 if (opt_ptr
== opt_end
)
85 goto out_invalid_option
;
89 goto out_invalid_option
;
91 * Remove the type and len fields, leaving
98 if (opt_ptr
> opt_end
)
99 goto out_invalid_option
;
105 case DCCPO_NDP_COUNT
:
107 goto out_invalid_option
;
109 opt_recv
->dccpor_ndp
= dccp_decode_value_var(value
, len
);
110 dccp_pr_debug("%sNDP count=%d\n", debug_prefix
,
111 opt_recv
->dccpor_ndp
);
113 case DCCPO_ACK_VECTOR_0
:
114 if (len
> DCCP_MAX_ACK_VECTOR_LEN
)
115 goto out_invalid_option
;
117 if (pkt_type
== DCCP_PKT_DATA
)
120 opt_recv
->dccpor_ack_vector_len
= len
;
121 opt_recv
->dccpor_ack_vector_idx
= value
- options
;
123 dccp_pr_debug("%sACK vector 0, len=%d, ack_ackno=%llu\n",
126 DCCP_SKB_CB(skb
)->dccpd_ack_seq
);
127 dccp_ackvector_print(DCCP_SKB_CB(skb
)->dccpd_ack_seq
,
129 dccp_ackpkts_check_rcv_ackvector(dp
->dccps_hc_rx_ackpkts
,
131 DCCP_SKB_CB(skb
)->dccpd_ack_seq
,
134 case DCCPO_TIMESTAMP
:
136 goto out_invalid_option
;
138 opt_recv
->dccpor_timestamp
= ntohl(*(u32
*)value
);
140 dp
->dccps_timestamp_echo
= opt_recv
->dccpor_timestamp
;
141 dp
->dccps_timestamp_time
= jiffies
;
143 dccp_pr_debug("%sTIMESTAMP=%u, ackno=%llu\n",
144 debug_prefix
, opt_recv
->dccpor_timestamp
,
146 DCCP_SKB_CB(skb
)->dccpd_ack_seq
);
148 case DCCPO_TIMESTAMP_ECHO
:
149 if (len
< 4 || len
> 8)
150 goto out_invalid_option
;
152 opt_recv
->dccpor_timestamp_echo
= ntohl(*(u32
*)value
);
154 dccp_pr_debug("%sTIMESTAMP_ECHO=%u, len=%d, ackno=%llu, "
157 opt_recv
->dccpor_timestamp_echo
,
160 DCCP_SKB_CB(skb
)->dccpd_ack_seq
,
162 opt_recv
->dccpor_timestamp_echo
));
164 opt_recv
->dccpor_elapsed_time
=
165 dccp_decode_value_var(value
+ 4,
167 dccp_pr_debug("%sTIMESTAMP_ECHO ELAPSED_TIME=%d\n",
169 opt_recv
->dccpor_elapsed_time
);
171 case DCCPO_ELAPSED_TIME
:
173 goto out_invalid_option
;
175 if (pkt_type
== DCCP_PKT_DATA
)
177 opt_recv
->dccpor_elapsed_time
=
178 dccp_decode_value_var(value
, len
);
179 dccp_pr_debug("%sELAPSED_TIME=%d\n", debug_prefix
,
180 opt_recv
->dccpor_elapsed_time
);
183 * From draft-ietf-dccp-spec-11.txt:
185 * Option numbers 128 through 191 are for
186 * options sent from the HC-Sender to the
187 * HC-Receiver; option numbers 192 through 255
188 * are for options sent from the HC-Receiver to
192 const u16 idx
= value
- options
;
194 if (ccid_hc_rx_parse_options(dp
->dccps_hc_rx_ccid
, sk
,
197 goto out_invalid_option
;
201 const u16 idx
= value
- options
;
203 if (ccid_hc_tx_parse_options(dp
->dccps_hc_tx_ccid
, sk
,
206 goto out_invalid_option
;
210 pr_info("DCCP(%p): option %d(len=%d) not "
211 "implemented, ignoring\n",
220 DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT
);
221 DCCP_SKB_CB(skb
)->dccpd_reset_code
= DCCP_RESET_CODE_OPTION_ERROR
;
222 pr_info("DCCP(%p): invalid option %d, len=%d\n", sk
, opt
, len
);
226 static void dccp_encode_value_var(const u32 value
, unsigned char *to
,
227 const unsigned int len
)
230 *to
++ = (value
& 0xFF000000) >> 24;
232 *to
++ = (value
& 0xFF0000) >> 16;
234 *to
++ = (value
& 0xFF00) >> 8;
236 *to
++ = (value
& 0xFF);
239 static inline int dccp_ndp_len(const int ndp
)
241 return likely(ndp
<= 0xFF) ? 1 : ndp
<= 0xFFFF ? 2 : 3;
244 void dccp_insert_option(struct sock
*sk
, struct sk_buff
*skb
,
245 const unsigned char option
,
246 const void *value
, const unsigned char len
)
250 if (DCCP_SKB_CB(skb
)->dccpd_opt_len
+ len
+ 2 > DCCP_MAX_OPT_LEN
) {
251 LIMIT_NETDEBUG(KERN_INFO
"DCCP: packet too small to insert "
252 "%d option!\n", option
);
256 DCCP_SKB_CB(skb
)->dccpd_opt_len
+= len
+ 2;
258 to
= skb_push(skb
, len
+ 2);
262 memcpy(to
, value
, len
);
265 EXPORT_SYMBOL_GPL(dccp_insert_option
);
267 static void dccp_insert_option_ndp(struct sock
*sk
, struct sk_buff
*skb
)
269 struct dccp_sock
*dp
= dccp_sk(sk
);
270 int ndp
= dp
->dccps_ndp_count
;
272 if (dccp_non_data_packet(skb
))
273 ++dp
->dccps_ndp_count
;
275 dp
->dccps_ndp_count
= 0;
279 const int ndp_len
= dccp_ndp_len(ndp
);
280 const int len
= ndp_len
+ 2;
282 if (DCCP_SKB_CB(skb
)->dccpd_opt_len
+ len
> DCCP_MAX_OPT_LEN
)
285 DCCP_SKB_CB(skb
)->dccpd_opt_len
+= len
;
287 ptr
= skb_push(skb
, len
);
288 *ptr
++ = DCCPO_NDP_COUNT
;
290 dccp_encode_value_var(ndp
, ptr
, ndp_len
);
294 static inline int dccp_elapsed_time_len(const u32 elapsed_time
)
296 return elapsed_time
== 0 ? 0 :
297 elapsed_time
<= 0xFF ? 1 :
298 elapsed_time
<= 0xFFFF ? 2 :
299 elapsed_time
<= 0xFFFFFF ? 3 : 4;
302 void dccp_insert_option_elapsed_time(struct sock
*sk
,
306 #ifdef CONFIG_IP_DCCP_DEBUG
307 struct dccp_sock
*dp
= dccp_sk(sk
);
308 const char *debug_prefix
= dp
->dccps_role
== DCCP_ROLE_CLIENT
?
309 "CLIENT TX opt: " : "server TX opt: ";
311 const int elapsed_time_len
= dccp_elapsed_time_len(elapsed_time
);
312 const int len
= 2 + elapsed_time_len
;
315 /* If elapsed_time == 0... */
316 if (elapsed_time_len
== 2)
319 if (DCCP_SKB_CB(skb
)->dccpd_opt_len
+ len
> DCCP_MAX_OPT_LEN
) {
320 LIMIT_NETDEBUG(KERN_INFO
"DCCP: packet too small to "
321 "insert elapsed time!\n");
325 DCCP_SKB_CB(skb
)->dccpd_opt_len
+= len
;
327 to
= skb_push(skb
, len
);
328 *to
++ = DCCPO_ELAPSED_TIME
;
331 dccp_encode_value_var(elapsed_time
, to
, elapsed_time_len
);
333 dccp_pr_debug("%sELAPSED_TIME=%u, len=%d, seqno=%llu\n",
334 debug_prefix
, elapsed_time
,
336 (unsigned long long) DCCP_SKB_CB(skb
)->dccpd_seq
);
339 EXPORT_SYMBOL(dccp_insert_option_elapsed_time
);
341 static void dccp_insert_option_ack_vector(struct sock
*sk
, struct sk_buff
*skb
)
343 struct dccp_sock
*dp
= dccp_sk(sk
);
344 #ifdef CONFIG_IP_DCCP_DEBUG
345 const char *debug_prefix
= dp
->dccps_role
== DCCP_ROLE_CLIENT
?
346 "CLIENT TX opt: " : "server TX opt: ";
348 struct dccp_ackpkts
*ap
= dp
->dccps_hc_rx_ackpkts
;
349 int len
= ap
->dccpap_buf_vector_len
+ 2;
350 const u32 elapsed_time
= jiffies_to_usecs(jiffies
- ap
->dccpap_time
) / 10;
351 unsigned char *to
, *from
;
353 if (elapsed_time
!= 0)
354 dccp_insert_option_elapsed_time(sk
, skb
, elapsed_time
);
356 if (DCCP_SKB_CB(skb
)->dccpd_opt_len
+ len
> DCCP_MAX_OPT_LEN
) {
357 LIMIT_NETDEBUG(KERN_INFO
"DCCP: packet too small to "
358 "insert ACK Vector!\n");
363 * XXX: now we have just one ack vector sent record, so
364 * we have to wait for it to be cleared.
366 * Of course this is not acceptable, but this is just for
369 if (ap
->dccpap_ack_seqno
!= DCCP_MAX_SEQNO
+ 1)
372 DCCP_SKB_CB(skb
)->dccpd_opt_len
+= len
;
374 to
= skb_push(skb
, len
);
375 *to
++ = DCCPO_ACK_VECTOR_0
;
378 len
= ap
->dccpap_buf_vector_len
;
379 from
= ap
->dccpap_buf
+ ap
->dccpap_buf_head
;
381 /* Check if buf_head wraps */
382 if (ap
->dccpap_buf_head
+ len
> ap
->dccpap_buf_len
) {
383 const unsigned int tailsize
= (ap
->dccpap_buf_len
-
384 ap
->dccpap_buf_head
);
386 memcpy(to
, from
, tailsize
);
389 from
= ap
->dccpap_buf
;
392 memcpy(to
, from
, len
);
394 * From draft-ietf-dccp-spec-11.txt:
396 * For each acknowledgement it sends, the HC-Receiver will add an
397 * acknowledgement record. ack_seqno will equal the HC-Receiver
398 * sequence number it used for the ack packet; ack_ptr will equal
399 * buf_head; ack_ackno will equal buf_ackno; and ack_nonce will
402 * This implemention uses just one ack record for now.
404 ap
->dccpap_ack_seqno
= DCCP_SKB_CB(skb
)->dccpd_seq
;
405 ap
->dccpap_ack_ptr
= ap
->dccpap_buf_head
;
406 ap
->dccpap_ack_ackno
= ap
->dccpap_buf_ackno
;
407 ap
->dccpap_ack_nonce
= ap
->dccpap_buf_nonce
;
408 ap
->dccpap_ack_vector_len
= ap
->dccpap_buf_vector_len
;
410 dccp_pr_debug("%sACK Vector 0, len=%d, ack_seqno=%llu, "
412 debug_prefix
, ap
->dccpap_ack_vector_len
,
413 (unsigned long long) ap
->dccpap_ack_seqno
,
414 (unsigned long long) ap
->dccpap_ack_ackno
);
417 static inline void dccp_insert_option_timestamp(struct sock
*sk
,
420 const u32 now
= htonl(tcp_time_stamp
);
421 dccp_insert_option(sk
, skb
, DCCPO_TIMESTAMP
, &now
, sizeof(now
));
424 static void dccp_insert_option_timestamp_echo(struct sock
*sk
,
427 struct dccp_sock
*dp
= dccp_sk(sk
);
428 #ifdef CONFIG_IP_DCCP_DEBUG
429 const char *debug_prefix
= dp
->dccps_role
== DCCP_ROLE_CLIENT
?
430 "CLIENT TX opt: " : "server TX opt: ";
433 const u32 elapsed_time
= jiffies_to_usecs(jiffies
-
434 dp
->dccps_timestamp_time
) / 10;
435 const int elapsed_time_len
= dccp_elapsed_time_len(elapsed_time
);
436 const int len
= 6 + elapsed_time_len
;
439 if (DCCP_SKB_CB(skb
)->dccpd_opt_len
+ len
> DCCP_MAX_OPT_LEN
) {
440 LIMIT_NETDEBUG(KERN_INFO
"DCCP: packet too small to insert "
441 "timestamp echo!\n");
445 DCCP_SKB_CB(skb
)->dccpd_opt_len
+= len
;
447 to
= skb_push(skb
, len
);
448 *to
++ = DCCPO_TIMESTAMP_ECHO
;
451 tstamp_echo
= htonl(dp
->dccps_timestamp_echo
);
452 memcpy(to
, &tstamp_echo
, 4);
454 dccp_encode_value_var(elapsed_time
, to
, elapsed_time_len
);
456 dccp_pr_debug("%sTIMESTAMP_ECHO=%u, len=%d, seqno=%llu\n",
457 debug_prefix
, dp
->dccps_timestamp_echo
,
459 (unsigned long long) DCCP_SKB_CB(skb
)->dccpd_seq
);
461 dp
->dccps_timestamp_echo
= 0;
462 dp
->dccps_timestamp_time
= 0;
465 void dccp_insert_options(struct sock
*sk
, struct sk_buff
*skb
)
467 struct dccp_sock
*dp
= dccp_sk(sk
);
469 DCCP_SKB_CB(skb
)->dccpd_opt_len
= 0;
471 if (dp
->dccps_options
.dccpo_send_ndp_count
)
472 dccp_insert_option_ndp(sk
, skb
);
474 if (!dccp_packet_without_ack(skb
)) {
475 if (dp
->dccps_options
.dccpo_send_ack_vector
&&
476 (dp
->dccps_hc_rx_ackpkts
->dccpap_buf_ackno
!=
478 dccp_insert_option_ack_vector(sk
, skb
);
480 dccp_insert_option_timestamp(sk
, skb
);
481 if (dp
->dccps_timestamp_echo
!= 0)
482 dccp_insert_option_timestamp_echo(sk
, skb
);
485 ccid_hc_rx_insert_options(dp
->dccps_hc_rx_ccid
, sk
, skb
);
486 ccid_hc_tx_insert_options(dp
->dccps_hc_tx_ccid
, sk
, skb
);
488 /* XXX: insert other options when appropriate */
490 if (DCCP_SKB_CB(skb
)->dccpd_opt_len
!= 0) {
491 /* The length of all options has to be a multiple of 4 */
492 int padding
= DCCP_SKB_CB(skb
)->dccpd_opt_len
% 4;
495 padding
= 4 - padding
;
496 memset(skb_push(skb
, padding
), 0, padding
);
497 DCCP_SKB_CB(skb
)->dccpd_opt_len
+= padding
;
502 struct dccp_ackpkts
*dccp_ackpkts_alloc(const unsigned int len
,
503 const unsigned int __nocast priority
)
505 struct dccp_ackpkts
*ap
= kmalloc(sizeof(*ap
) + len
, priority
);
508 #ifdef CONFIG_IP_DCCP_DEBUG
509 memset(ap
->dccpap_buf
, 0xFF, len
);
511 ap
->dccpap_buf_len
= len
;
512 ap
->dccpap_buf_head
=
513 ap
->dccpap_buf_tail
=
514 ap
->dccpap_buf_len
- 1;
515 ap
->dccpap_buf_ackno
=
516 ap
->dccpap_ack_ackno
=
517 ap
->dccpap_ack_seqno
= DCCP_MAX_SEQNO
+ 1;
518 ap
->dccpap_buf_nonce
= ap
->dccpap_buf_nonce
= 0;
519 ap
->dccpap_ack_ptr
= 0;
521 ap
->dccpap_buf_vector_len
= ap
->dccpap_ack_vector_len
= 0;
527 void dccp_ackpkts_free(struct dccp_ackpkts
*ap
)
530 #ifdef CONFIG_IP_DCCP_DEBUG
531 memset(ap
, 0xFF, sizeof(*ap
) + ap
->dccpap_buf_len
);
537 static inline u8
dccp_ackpkts_state(const struct dccp_ackpkts
*ap
,
538 const unsigned int index
)
540 return ap
->dccpap_buf
[index
] & DCCP_ACKPKTS_STATE_MASK
;
543 static inline u8
dccp_ackpkts_len(const struct dccp_ackpkts
*ap
,
544 const unsigned int index
)
546 return ap
->dccpap_buf
[index
] & DCCP_ACKPKTS_LEN_MASK
;
550 * If several packets are missing, the HC-Receiver may prefer to enter multiple
551 * bytes with run length 0, rather than a single byte with a larger run length;
552 * this simplifies table updates if one of the missing packets arrives.
554 static inline int dccp_ackpkts_set_buf_head_state(struct dccp_ackpkts
*ap
,
555 const unsigned int packets
,
556 const unsigned char state
)
559 signed long new_head
;
561 if (ap
->dccpap_buf_vector_len
+ packets
> ap
->dccpap_buf_len
)
565 new_head
= ap
->dccpap_buf_head
- packets
;
569 memset(ap
->dccpap_buf
, DCCP_ACKPKTS_STATE_NOT_RECEIVED
,
573 new_head
+= ap
->dccpap_buf_len
;
576 ap
->dccpap_buf_head
= new_head
;
579 memset(ap
->dccpap_buf
+ ap
->dccpap_buf_head
+ 1,
580 DCCP_ACKPKTS_STATE_NOT_RECEIVED
, gap
);
582 ap
->dccpap_buf
[ap
->dccpap_buf_head
] = state
;
583 ap
->dccpap_buf_vector_len
+= packets
;
588 * Implements the draft-ietf-dccp-spec-11.txt Appendix A
590 int dccp_ackpkts_add(struct dccp_ackpkts
*ap
, u64 ackno
, u8 state
)
593 * Check at the right places if the buffer is full, if it is, tell the
594 * caller to start dropping packets till the HC-Sender acks our ACK
595 * vectors, when we will free up space in dccpap_buf.
597 * We may well decide to do buffer compression, etc, but for now lets
602 * Of course, the circular buffer may overflow, either when the
603 * HC-Sender is sending data at a very high rate, when the
604 * HC-Receiver's acknowledgements are not reaching the HC-Sender,
605 * or when the HC-Sender is forgetting to acknowledge those acks
606 * (so the HC-Receiver is unable to clean up old state). In this
607 * case, the HC-Receiver should either compress the buffer (by
608 * increasing run lengths when possible), transfer its state to
609 * a larger buffer, or, as a last resort, drop all received
610 * packets, without processing them whatsoever, until its buffer
614 /* See if this is the first ackno being inserted */
615 if (ap
->dccpap_buf_vector_len
== 0) {
616 ap
->dccpap_buf
[ap
->dccpap_buf_head
] = state
;
617 ap
->dccpap_buf_vector_len
= 1;
618 } else if (after48(ackno
, ap
->dccpap_buf_ackno
)) {
619 const u64 delta
= dccp_delta_seqno(ap
->dccpap_buf_ackno
,
623 * Look if the state of this packet is the same as the
624 * previous ackno and if so if we can bump the head len.
627 dccp_ackpkts_state(ap
, ap
->dccpap_buf_head
) == state
&&
628 (dccp_ackpkts_len(ap
, ap
->dccpap_buf_head
) <
629 DCCP_ACKPKTS_LEN_MASK
))
630 ap
->dccpap_buf
[ap
->dccpap_buf_head
]++;
631 else if (dccp_ackpkts_set_buf_head_state(ap
, delta
, state
))
637 * When a packet with Sequence Number S arrives, and
638 * S <= buf_ackno, the HC-Receiver will scan the table
639 * for the byte corresponding to S. (Indexing structures
640 * could reduce the complexity of this scan.)
642 u64 delta
= dccp_delta_seqno(ackno
, ap
->dccpap_buf_ackno
);
643 unsigned int index
= ap
->dccpap_buf_head
;
646 const u8 len
= dccp_ackpkts_len(ap
, index
);
647 const u8 state
= dccp_ackpkts_state(ap
, index
);
649 * valid packets not yet in dccpap_buf have a reserved
650 * entry, with a len equal to 0.
652 if (state
== DCCP_ACKPKTS_STATE_NOT_RECEIVED
&&
653 len
== 0 && delta
== 0) { /* Found our
655 dccp_pr_debug("Found %llu reserved seat!\n",
656 (unsigned long long) ackno
);
657 ap
->dccpap_buf
[index
] = state
;
660 /* len == 0 means one packet */
665 if (++index
== ap
->dccpap_buf_len
)
670 ap
->dccpap_buf_ackno
= ackno
;
671 ap
->dccpap_time
= jiffies
;
674 dccp_ackpkts_print(ap
);
678 /* Duplicate packet */
679 dccp_pr_debug("Received a dup or already considered lost "
680 "packet: %llu\n", (unsigned long long) ackno
);
684 #ifdef CONFIG_IP_DCCP_DEBUG
685 void dccp_ackvector_print(const u64 ackno
, const unsigned char *vector
,
691 printk("ACK vector len=%d, ackno=%llu |", len
,
692 (unsigned long long) ackno
);
695 const u8 state
= (*vector
& DCCP_ACKPKTS_STATE_MASK
) >> 6;
696 const u8 rl
= (*vector
& DCCP_ACKPKTS_LEN_MASK
);
698 printk("%d,%d|", state
, rl
);
705 void dccp_ackpkts_print(const struct dccp_ackpkts
*ap
)
707 dccp_ackvector_print(ap
->dccpap_buf_ackno
,
708 ap
->dccpap_buf
+ ap
->dccpap_buf_head
,
709 ap
->dccpap_buf_vector_len
);
713 static void dccp_ackpkts_trow_away_ack_record(struct dccp_ackpkts
*ap
)
716 * As we're keeping track of the ack vector size
717 * (dccpap_buf_vector_len) and the sent ack vector size
718 * (dccpap_ack_vector_len) we don't need dccpap_buf_tail at all, but
719 * keep this code here as in the future we'll implement a vector of
720 * ack records, as suggested in draft-ietf-dccp-spec-11.txt
724 ap
->dccpap_buf_tail
= ap
->dccpap_ack_ptr
+ 1;
725 if (ap
->dccpap_buf_tail
>= ap
->dccpap_buf_len
)
726 ap
->dccpap_buf_tail
-= ap
->dccpap_buf_len
;
728 ap
->dccpap_buf_vector_len
-= ap
->dccpap_ack_vector_len
;
731 void dccp_ackpkts_check_rcv_ackno(struct dccp_ackpkts
*ap
, struct sock
*sk
,
734 /* Check if we actually sent an ACK vector */
735 if (ap
->dccpap_ack_seqno
== DCCP_MAX_SEQNO
+ 1)
738 if (ackno
== ap
->dccpap_ack_seqno
) {
739 #ifdef CONFIG_IP_DCCP_DEBUG
740 struct dccp_sock
*dp
= dccp_sk(sk
);
741 const char *debug_prefix
= dp
->dccps_role
== DCCP_ROLE_CLIENT
?
742 "CLIENT rx ack: " : "server rx ack: ";
744 dccp_pr_debug("%sACK packet 0, len=%d, ack_seqno=%llu, "
745 "ack_ackno=%llu, ACKED!\n",
747 (unsigned long long) ap
->dccpap_ack_seqno
,
748 (unsigned long long) ap
->dccpap_ack_ackno
);
749 dccp_ackpkts_trow_away_ack_record(ap
);
750 ap
->dccpap_ack_seqno
= DCCP_MAX_SEQNO
+ 1;
754 static void dccp_ackpkts_check_rcv_ackvector(struct dccp_ackpkts
*ap
,
755 struct sock
*sk
, u64 ackno
,
756 const unsigned char len
,
757 const unsigned char *vector
)
761 /* Check if we actually sent an ACK vector */
762 if (ap
->dccpap_ack_seqno
== DCCP_MAX_SEQNO
+ 1)
765 * We're in the receiver half connection, so if the received an ACK
766 * vector ackno (e.g. 50) before dccpap_ack_seqno (e.g. 52), we're
769 * Extra explanation with example:
771 * if we received an ACK vector with ackno 50, it can only be acking
772 * 50, 49, 48, etc, not 52 (the seqno for the ACK vector we sent).
774 /* dccp_pr_debug("is %llu < %llu? ", ackno, ap->dccpap_ack_seqno); */
775 if (before48(ackno
, ap
->dccpap_ack_seqno
)) {
776 /* dccp_pr_debug_cat("yes\n"); */
779 /* dccp_pr_debug_cat("no\n"); */
783 const u8 rl
= (*vector
& DCCP_ACKPKTS_LEN_MASK
);
786 dccp_set_seqno(&ackno_end_rl
, ackno
- rl
);
789 * dccp_pr_debug("is %llu <= %llu <= %llu? ", ackno_end_rl,
790 * ap->dccpap_ack_seqno, ackno);
792 if (between48(ap
->dccpap_ack_seqno
, ackno_end_rl
, ackno
)) {
793 const u8 state
= (*vector
&
794 DCCP_ACKPKTS_STATE_MASK
) >> 6;
795 /* dccp_pr_debug_cat("yes\n"); */
797 if (state
!= DCCP_ACKPKTS_STATE_NOT_RECEIVED
) {
798 #ifdef CONFIG_IP_DCCP_DEBUG
799 struct dccp_sock
*dp
= dccp_sk(sk
);
800 const char *debug_prefix
=
801 dp
->dccps_role
== DCCP_ROLE_CLIENT
?
802 "CLIENT rx ack: " : "server rx ack: ";
804 dccp_pr_debug("%sACK vector 0, len=%d, "
805 "ack_seqno=%llu, ack_ackno=%llu, "
809 ap
->dccpap_ack_seqno
,
811 ap
->dccpap_ack_ackno
);
812 dccp_ackpkts_trow_away_ack_record(ap
);
815 * If dccpap_ack_seqno was not received, no problem
816 * we'll send another ACK vector.
818 ap
->dccpap_ack_seqno
= DCCP_MAX_SEQNO
+ 1;
821 /* dccp_pr_debug_cat("no\n"); */
823 dccp_set_seqno(&ackno
, ackno_end_rl
- 1);