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
);
62 const char *debug_prefix
= dp
->dccps_role
== DCCP_ROLE_CLIENT
? "CLIENT 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
+ (dh
->dccph_doff
* 4);
70 struct dccp_options_received
*opt_recv
= &dp
->dccps_options_received
;
71 unsigned char opt
, len
;
74 memset(opt_recv
, 0, sizeof(*opt_recv
));
76 while (opt_ptr
!= opt_end
) {
81 /* Check if this isn't a single byte option */
82 if (opt
> DCCPO_MAX_RESERVED
) {
83 if (opt_ptr
== opt_end
)
84 goto out_invalid_option
;
88 goto out_invalid_option
;
90 * Remove the type and len fields, leaving
97 if (opt_ptr
> opt_end
)
98 goto out_invalid_option
;
104 case DCCPO_NDP_COUNT
:
106 goto out_invalid_option
;
108 opt_recv
->dccpor_ndp
= dccp_decode_value_var(value
, len
);
109 dccp_pr_debug("%sNDP count=%d\n", debug_prefix
, opt_recv
->dccpor_ndp
);
111 case DCCPO_ACK_VECTOR_0
:
112 if (len
> DCCP_MAX_ACK_VECTOR_LEN
)
113 goto out_invalid_option
;
115 if (pkt_type
== DCCP_PKT_DATA
)
118 opt_recv
->dccpor_ack_vector_len
= len
;
119 opt_recv
->dccpor_ack_vector_idx
= value
- options
;
121 dccp_pr_debug("%sACK vector 0, len=%d, ack_ackno=%llu\n",
124 DCCP_SKB_CB(skb
)->dccpd_ack_seq
);
125 dccp_ackvector_print(DCCP_SKB_CB(skb
)->dccpd_ack_seq
,
127 dccp_ackpkts_check_rcv_ackvector(dp
->dccps_hc_rx_ackpkts
, sk
,
128 DCCP_SKB_CB(skb
)->dccpd_ack_seq
,
131 case DCCPO_TIMESTAMP
:
133 goto out_invalid_option
;
135 opt_recv
->dccpor_timestamp
= ntohl(*(u32
*)value
);
137 dp
->dccps_timestamp_echo
= opt_recv
->dccpor_timestamp
;
138 dp
->dccps_timestamp_time
= jiffies
;
140 dccp_pr_debug("%sTIMESTAMP=%u, ackno=%llu\n",
141 debug_prefix
, opt_recv
->dccpor_timestamp
,
143 DCCP_SKB_CB(skb
)->dccpd_ack_seq
);
145 case DCCPO_TIMESTAMP_ECHO
:
146 if (len
< 4 || len
> 8)
147 goto out_invalid_option
;
149 opt_recv
->dccpor_timestamp_echo
= ntohl(*(u32
*)value
);
151 dccp_pr_debug("%sTIMESTAMP_ECHO=%u, len=%d, ackno=%llu, diff=%u\n",
152 debug_prefix
, opt_recv
->dccpor_timestamp_echo
,
155 DCCP_SKB_CB(skb
)->dccpd_ack_seq
,
156 tcp_time_stamp
- opt_recv
->dccpor_timestamp_echo
);
158 opt_recv
->dccpor_elapsed_time
= dccp_decode_value_var(value
+ 4, len
- 4);
159 dccp_pr_debug("%sTIMESTAMP_ECHO ELAPSED_TIME=%d\n", debug_prefix
,
160 opt_recv
->dccpor_elapsed_time
);
162 case DCCPO_ELAPSED_TIME
:
164 goto out_invalid_option
;
166 if (pkt_type
== DCCP_PKT_DATA
)
168 opt_recv
->dccpor_elapsed_time
= dccp_decode_value_var(value
, len
);
169 dccp_pr_debug("%sELAPSED_TIME=%d\n", debug_prefix
,
170 opt_recv
->dccpor_elapsed_time
);
173 * From draft-ietf-dccp-spec-11.txt:
175 * Option numbers 128 through 191 are for options sent from the HC-
176 * Sender to the HC-Receiver; option numbers 192 through 255 are for
177 * options sent from the HC-Receiver to the HC-Sender.
180 const u16 idx
= value
- options
;
182 if (ccid_hc_rx_parse_options(dp
->dccps_hc_rx_ccid
, sk
, opt
, len
, idx
, value
) != 0)
183 goto out_invalid_option
;
187 const u16 idx
= value
- options
;
189 if (ccid_hc_tx_parse_options(dp
->dccps_hc_tx_ccid
, sk
, opt
, len
, idx
, value
) != 0)
190 goto out_invalid_option
;
194 pr_info("DCCP(%p): option %d(len=%d) not implemented, ignoring\n",
203 DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT
);
204 DCCP_SKB_CB(skb
)->dccpd_reset_code
= DCCP_RESET_CODE_OPTION_ERROR
;
205 pr_info("DCCP(%p): invalid option %d, len=%d\n", sk
, opt
, len
);
209 static void dccp_encode_value_var(const u32 value
, unsigned char *to
,
210 const unsigned int len
)
213 *to
++ = (value
& 0xFF000000) >> 24;
215 *to
++ = (value
& 0xFF0000) >> 16;
217 *to
++ = (value
& 0xFF00) >> 8;
219 *to
++ = (value
& 0xFF);
222 static inline int dccp_ndp_len(const int ndp
)
224 return likely(ndp
<= 0xFF) ? 1 : ndp
<= 0xFFFF ? 2 : 3;
227 void dccp_insert_option(struct sock
*sk
, struct sk_buff
*skb
,
228 const unsigned char option
,
229 const void *value
, const unsigned char len
)
233 if (DCCP_SKB_CB(skb
)->dccpd_opt_len
+ len
+ 2 > DCCP_MAX_OPT_LEN
) {
234 LIMIT_NETDEBUG(KERN_INFO
"DCCP: packet too small to insert %d option!\n", option
);
238 DCCP_SKB_CB(skb
)->dccpd_opt_len
+= len
+ 2;
240 to
= skb_push(skb
, len
+ 2);
244 memcpy(to
, value
, len
);
247 EXPORT_SYMBOL_GPL(dccp_insert_option
);
249 static void dccp_insert_option_ndp(struct sock
*sk
, struct sk_buff
*skb
)
251 struct dccp_sock
*dp
= dccp_sk(sk
);
252 int ndp
= dp
->dccps_ndp_count
;
254 if (dccp_non_data_packet(skb
))
255 ++dp
->dccps_ndp_count
;
257 dp
->dccps_ndp_count
= 0;
261 const int ndp_len
= dccp_ndp_len(ndp
);
262 const int len
= ndp_len
+ 2;
264 if (DCCP_SKB_CB(skb
)->dccpd_opt_len
+ len
> DCCP_MAX_OPT_LEN
)
267 DCCP_SKB_CB(skb
)->dccpd_opt_len
+= len
;
269 ptr
= skb_push(skb
, len
);
270 *ptr
++ = DCCPO_NDP_COUNT
;
272 dccp_encode_value_var(ndp
, ptr
, ndp_len
);
276 static inline int dccp_elapsed_time_len(const u32 elapsed_time
)
278 return elapsed_time
== 0 ? 0 :
279 elapsed_time
<= 0xFF ? 1 :
280 elapsed_time
<= 0xFFFF ? 2 :
281 elapsed_time
<= 0xFFFFFF ? 3 : 4;
284 void dccp_insert_option_elapsed_time(struct sock
*sk
,
289 struct dccp_sock
*dp
= dccp_sk(sk
);
290 const char *debug_prefix
= dp
->dccps_role
== DCCP_ROLE_CLIENT
? "CLIENT TX opt: " :
293 const int elapsed_time_len
= dccp_elapsed_time_len(elapsed_time
);
294 const int len
= 2 + elapsed_time_len
;
297 /* If elapsed_time == 0... */
298 if (elapsed_time_len
== 2)
301 if (DCCP_SKB_CB(skb
)->dccpd_opt_len
+ len
> DCCP_MAX_OPT_LEN
) {
302 LIMIT_NETDEBUG(KERN_INFO
"DCCP: packet too small to insert elapsed time!\n");
306 DCCP_SKB_CB(skb
)->dccpd_opt_len
+= len
;
308 to
= skb_push(skb
, len
);
309 *to
++ = DCCPO_ELAPSED_TIME
;
312 dccp_encode_value_var(elapsed_time
, to
, elapsed_time_len
);
314 dccp_pr_debug("%sELAPSED_TIME=%u, len=%d, seqno=%llu\n",
315 debug_prefix
, elapsed_time
,
317 (unsigned long long) DCCP_SKB_CB(skb
)->dccpd_seq
);
320 EXPORT_SYMBOL(dccp_insert_option_elapsed_time
);
322 static void dccp_insert_option_ack_vector(struct sock
*sk
, struct sk_buff
*skb
)
324 struct dccp_sock
*dp
= dccp_sk(sk
);
326 const char *debug_prefix
= dp
->dccps_role
== DCCP_ROLE_CLIENT
? "CLIENT TX opt: " :
329 struct dccp_ackpkts
*ap
= dp
->dccps_hc_rx_ackpkts
;
330 int len
= ap
->dccpap_buf_vector_len
+ 2;
331 const u32 elapsed_time
= jiffies_to_usecs(jiffies
- ap
->dccpap_time
) / 10;
332 unsigned char *to
, *from
;
334 if (elapsed_time
!= 0)
335 dccp_insert_option_elapsed_time(sk
, skb
, elapsed_time
);
337 if (DCCP_SKB_CB(skb
)->dccpd_opt_len
+ len
> DCCP_MAX_OPT_LEN
) {
338 LIMIT_NETDEBUG(KERN_INFO
"DCCP: packet too small to insert ACK Vector!\n");
343 * XXX: now we have just one ack vector sent record, so
344 * we have to wait for it to be cleared.
346 * Of course this is not acceptable, but this is just for
349 if (ap
->dccpap_ack_seqno
!= DCCP_MAX_SEQNO
+ 1)
352 DCCP_SKB_CB(skb
)->dccpd_opt_len
+= len
;
354 to
= skb_push(skb
, len
);
355 *to
++ = DCCPO_ACK_VECTOR_0
;
358 len
= ap
->dccpap_buf_vector_len
;
359 from
= ap
->dccpap_buf
+ ap
->dccpap_buf_head
;
361 /* Check if buf_head wraps */
362 if (ap
->dccpap_buf_head
+ len
> ap
->dccpap_buf_len
) {
363 const unsigned int tailsize
= ap
->dccpap_buf_len
- ap
->dccpap_buf_head
;
365 memcpy(to
, from
, tailsize
);
368 from
= ap
->dccpap_buf
;
371 memcpy(to
, from
, len
);
373 * From draft-ietf-dccp-spec-11.txt:
375 * For each acknowledgement it sends, the HC-Receiver will add an
376 * acknowledgement record. ack_seqno will equal the HC-Receiver
377 * sequence number it used for the ack packet; ack_ptr will equal
378 * buf_head; ack_ackno will equal buf_ackno; and ack_nonce will equal
381 * This implemention uses just one ack record for now.
383 ap
->dccpap_ack_seqno
= DCCP_SKB_CB(skb
)->dccpd_seq
;
384 ap
->dccpap_ack_ptr
= ap
->dccpap_buf_head
;
385 ap
->dccpap_ack_ackno
= ap
->dccpap_buf_ackno
;
386 ap
->dccpap_ack_nonce
= ap
->dccpap_buf_nonce
;
387 ap
->dccpap_ack_vector_len
= ap
->dccpap_buf_vector_len
;
389 dccp_pr_debug("%sACK Vector 0, len=%d, ack_seqno=%llu, ack_ackno=%llu\n",
390 debug_prefix
, ap
->dccpap_ack_vector_len
,
391 (unsigned long long) ap
->dccpap_ack_seqno
,
392 (unsigned long long) ap
->dccpap_ack_ackno
);
395 static inline void dccp_insert_option_timestamp(struct sock
*sk
, struct sk_buff
*skb
)
397 const u32 now
= htonl(tcp_time_stamp
);
398 dccp_insert_option(sk
, skb
, DCCPO_TIMESTAMP
, &now
, sizeof(now
));
401 static void dccp_insert_option_timestamp_echo(struct sock
*sk
, struct sk_buff
*skb
)
403 struct dccp_sock
*dp
= dccp_sk(sk
);
405 const char *debug_prefix
= dp
->dccps_role
== DCCP_ROLE_CLIENT
? "CLIENT TX opt: " :
409 const u32 elapsed_time
= jiffies_to_usecs(jiffies
- dp
->dccps_timestamp_time
) / 10;
410 const int elapsed_time_len
= dccp_elapsed_time_len(elapsed_time
);
411 const int len
= 6 + elapsed_time_len
;
414 if (DCCP_SKB_CB(skb
)->dccpd_opt_len
+ len
> DCCP_MAX_OPT_LEN
) {
415 LIMIT_NETDEBUG(KERN_INFO
"DCCP: packet too small to insert timestamp echo!\n");
419 DCCP_SKB_CB(skb
)->dccpd_opt_len
+= len
;
421 to
= skb_push(skb
, len
);
422 *to
++ = DCCPO_TIMESTAMP_ECHO
;
425 tstamp_echo
= htonl(dp
->dccps_timestamp_echo
);
426 memcpy(to
, &tstamp_echo
, 4);
428 dccp_encode_value_var(elapsed_time
, to
, elapsed_time_len
);
430 dccp_pr_debug("%sTIMESTAMP_ECHO=%u, len=%d, seqno=%llu\n",
431 debug_prefix
, dp
->dccps_timestamp_echo
,
433 (unsigned long long) DCCP_SKB_CB(skb
)->dccpd_seq
);
435 dp
->dccps_timestamp_echo
= 0;
436 dp
->dccps_timestamp_time
= 0;
439 void dccp_insert_options(struct sock
*sk
, struct sk_buff
*skb
)
441 struct dccp_sock
*dp
= dccp_sk(sk
);
443 DCCP_SKB_CB(skb
)->dccpd_opt_len
= 0;
445 if (dp
->dccps_options
.dccpo_send_ndp_count
)
446 dccp_insert_option_ndp(sk
, skb
);
448 if (!dccp_packet_without_ack(skb
)) {
449 if (dp
->dccps_options
.dccpo_send_ack_vector
&&
450 dp
->dccps_hc_rx_ackpkts
->dccpap_buf_ackno
!= DCCP_MAX_SEQNO
+ 1)
451 dccp_insert_option_ack_vector(sk
, skb
);
453 dccp_insert_option_timestamp(sk
, skb
);
454 if (dp
->dccps_timestamp_echo
!= 0)
455 dccp_insert_option_timestamp_echo(sk
, skb
);
458 ccid_hc_rx_insert_options(dp
->dccps_hc_rx_ccid
, sk
, skb
);
459 ccid_hc_tx_insert_options(dp
->dccps_hc_tx_ccid
, sk
, skb
);
461 /* XXX: insert other options when appropriate */
463 if (DCCP_SKB_CB(skb
)->dccpd_opt_len
!= 0) {
464 /* The length of all options has to be a multiple of 4 */
465 int padding
= DCCP_SKB_CB(skb
)->dccpd_opt_len
% 4;
468 padding
= 4 - padding
;
469 memset(skb_push(skb
, padding
), 0, padding
);
470 DCCP_SKB_CB(skb
)->dccpd_opt_len
+= padding
;
475 struct dccp_ackpkts
*dccp_ackpkts_alloc(unsigned int len
, int priority
)
477 struct dccp_ackpkts
*ap
= kmalloc(sizeof(*ap
) + len
, priority
);
481 memset(ap
->dccpap_buf
, 0xFF, len
);
483 ap
->dccpap_buf_len
= len
;
484 ap
->dccpap_buf_head
= ap
->dccpap_buf_tail
= ap
->dccpap_buf_len
- 1;
485 ap
->dccpap_buf_ackno
= ap
->dccpap_ack_ackno
= ap
->dccpap_ack_seqno
= DCCP_MAX_SEQNO
+ 1;
486 ap
->dccpap_buf_nonce
= ap
->dccpap_buf_nonce
= 0;
487 ap
->dccpap_ack_ptr
= 0;
489 ap
->dccpap_buf_vector_len
= ap
->dccpap_ack_vector_len
= 0;
495 void dccp_ackpkts_free(struct dccp_ackpkts
*ap
)
499 memset(ap
, 0xFF, sizeof(*ap
) + ap
->dccpap_buf_len
);
505 static inline u8
dccp_ackpkts_state(const struct dccp_ackpkts
*ap
,
506 const unsigned int index
)
508 return ap
->dccpap_buf
[index
] & DCCP_ACKPKTS_STATE_MASK
;
511 static inline u8
dccp_ackpkts_len(const struct dccp_ackpkts
*ap
,
512 const unsigned int index
)
514 return ap
->dccpap_buf
[index
] & DCCP_ACKPKTS_LEN_MASK
;
518 * If several packets are missing, the HC-Receiver may prefer to enter multiple
519 * bytes with run length 0, rather than a single byte with a larger run length;
520 * this simplifies table updates if one of the missing packets arrives.
522 static inline int dccp_ackpkts_set_buf_head_state(struct dccp_ackpkts
*ap
,
523 const unsigned int packets
,
524 const unsigned char state
)
527 signed long new_head
;
529 if (ap
->dccpap_buf_vector_len
+ packets
> ap
->dccpap_buf_len
)
533 new_head
= ap
->dccpap_buf_head
- packets
;
537 memset(ap
->dccpap_buf
, DCCP_ACKPKTS_STATE_NOT_RECEIVED
,
541 new_head
+= ap
->dccpap_buf_len
;
544 ap
->dccpap_buf_head
= new_head
;
547 memset(ap
->dccpap_buf
+ ap
->dccpap_buf_head
+ 1,
548 DCCP_ACKPKTS_STATE_NOT_RECEIVED
, gap
);
550 ap
->dccpap_buf
[ap
->dccpap_buf_head
] = state
;
551 ap
->dccpap_buf_vector_len
+= packets
;
556 * Implements the draft-ietf-dccp-spec-11.txt Appendix A
558 int dccp_ackpkts_add(struct dccp_ackpkts
*ap
, u64 ackno
, u8 state
)
561 * Check at the right places if the buffer is full, if it is, tell the
562 * caller to start dropping packets till the HC-Sender acks our ACK
563 * vectors, when we will free up space in dccpap_buf.
565 * We may well decide to do buffer compression, etc, but for now lets
570 * Of course, the circular buffer may overflow, either when the HC-
571 * Sender is sending data at a very high rate, when the HC-Receiver's
572 * acknowledgements are not reaching the HC-Sender, or when the HC-
573 * Sender is forgetting to acknowledge those acks (so the HC-Receiver
574 * is unable to clean up old state). In this case, the HC-Receiver
575 * should either compress the buffer (by increasing run lengths when
576 * possible), transfer its state to a larger buffer, or, as a last
577 * resort, drop all received packets, without processing them
578 * whatsoever, until its buffer shrinks again.
581 /* See if this is the first ackno being inserted */
582 if (ap
->dccpap_buf_vector_len
== 0) {
583 ap
->dccpap_buf
[ap
->dccpap_buf_head
] = state
;
584 ap
->dccpap_buf_vector_len
= 1;
585 } else if (after48(ackno
, ap
->dccpap_buf_ackno
)) {
586 const u64 delta
= dccp_delta_seqno(ap
->dccpap_buf_ackno
, ackno
);
589 * Look if the state of this packet is the same as the previous ackno
590 * and if so if we can bump the head len.
593 dccp_ackpkts_state(ap
, ap
->dccpap_buf_head
) == state
&&
594 dccp_ackpkts_len(ap
, ap
->dccpap_buf_head
) < DCCP_ACKPKTS_LEN_MASK
)
595 ap
->dccpap_buf
[ap
->dccpap_buf_head
]++;
596 else if (dccp_ackpkts_set_buf_head_state(ap
, delta
, state
))
602 * When a packet with Sequence Number S arrives, and S <= buf_ackno,
603 * the HC-Receiver will scan the table for the byte corresponding to S.
604 * (Indexing structures could reduce the complexity of this scan.)
606 u64 delta
= dccp_delta_seqno(ackno
, ap
->dccpap_buf_ackno
);
607 unsigned int index
= ap
->dccpap_buf_head
;
610 const u8 len
= dccp_ackpkts_len(ap
, index
);
611 const u8 state
= dccp_ackpkts_state(ap
, index
);
613 * valid packets not yet in dccpap_buf have a reserved entry, with
616 if (state
== DCCP_ACKPKTS_STATE_NOT_RECEIVED
&&
617 len
== 0 && delta
== 0) { /* Found our reserved seat! */
618 dccp_pr_debug("Found %llu reserved seat!\n",
619 (unsigned long long) ackno
);
620 ap
->dccpap_buf
[index
] = state
;
623 /* len == 0 means one packet */
628 if (++index
== ap
->dccpap_buf_len
)
633 ap
->dccpap_buf_ackno
= ackno
;
634 ap
->dccpap_time
= jiffies
;
637 dccp_ackpkts_print(ap
);
641 /* Duplicate packet */
642 dccp_pr_debug("Received a dup or already considered lost packet: %llu\n",
643 (unsigned long long) ackno
);
648 void dccp_ackvector_print(const u64 ackno
, const unsigned char *vector
, int len
)
653 printk("ACK vector len=%d, ackno=%llu |", len
,
654 (unsigned long long) ackno
);
657 const u8 state
= (*vector
& DCCP_ACKPKTS_STATE_MASK
) >> 6;
658 const u8 rl
= (*vector
& DCCP_ACKPKTS_LEN_MASK
);
660 printk("%d,%d|", state
, rl
);
667 void dccp_ackpkts_print(const struct dccp_ackpkts
*ap
)
669 dccp_ackvector_print(ap
->dccpap_buf_ackno
,
670 ap
->dccpap_buf
+ ap
->dccpap_buf_head
,
671 ap
->dccpap_buf_vector_len
);
675 static void dccp_ackpkts_trow_away_ack_record(struct dccp_ackpkts
*ap
)
678 * As we're keeping track of the ack vector size
679 * (dccpap_buf_vector_len) and the sent ack vector size
680 * (dccpap_ack_vector_len) we don't need dccpap_buf_tail at all, but
681 * keep this code here as in the future we'll implement a vector of ack
682 * records, as suggested in draft-ietf-dccp-spec-11.txt Appendix A. -acme
685 ap
->dccpap_buf_tail
= ap
->dccpap_ack_ptr
+ 1;
686 if (ap
->dccpap_buf_tail
>= ap
->dccpap_buf_len
)
687 ap
->dccpap_buf_tail
-= ap
->dccpap_buf_len
;
689 ap
->dccpap_buf_vector_len
-= ap
->dccpap_ack_vector_len
;
692 void dccp_ackpkts_check_rcv_ackno(struct dccp_ackpkts
*ap
, struct sock
*sk
,
695 /* Check if we actually sent an ACK vector */
696 if (ap
->dccpap_ack_seqno
== DCCP_MAX_SEQNO
+ 1)
699 if (ackno
== ap
->dccpap_ack_seqno
) {
701 struct dccp_sock
*dp
= dccp_sk(sk
);
702 const char *debug_prefix
= dp
->dccps_role
== DCCP_ROLE_CLIENT
? "CLIENT rx ack: " :
705 dccp_pr_debug("%sACK packet 0, len=%d, ack_seqno=%llu, ack_ackno=%llu, ACKED!\n",
707 (unsigned long long) ap
->dccpap_ack_seqno
,
708 (unsigned long long) ap
->dccpap_ack_ackno
);
709 dccp_ackpkts_trow_away_ack_record(ap
);
710 ap
->dccpap_ack_seqno
= DCCP_MAX_SEQNO
+ 1;
714 static void dccp_ackpkts_check_rcv_ackvector(struct dccp_ackpkts
*ap
,
715 struct sock
*sk
, u64 ackno
,
716 const unsigned char len
,
717 const unsigned char *vector
)
721 /* Check if we actually sent an ACK vector */
722 if (ap
->dccpap_ack_seqno
== DCCP_MAX_SEQNO
+ 1)
725 * We're in the receiver half connection, so if the received an ACK vector
726 * ackno (e.g. 50) before dccpap_ack_seqno (e.g. 52), we're not interested.
728 * Extra explanation with example:
730 * if we received an ACK vector with ackno 50, it can only be acking
731 * 50, 49, 48, etc, not 52 (the seqno for the ACK vector we sent).
733 // dccp_pr_debug("is %llu < %llu? ", ackno, ap->dccpap_ack_seqno);
734 if (before48(ackno
, ap
->dccpap_ack_seqno
)) {
735 // dccp_pr_debug_cat("yes\n");
738 // dccp_pr_debug_cat("no\n");
742 const u8 rl
= (*vector
& DCCP_ACKPKTS_LEN_MASK
);
745 dccp_set_seqno(&ackno_end_rl
, ackno
- rl
);
747 // dccp_pr_debug("is %llu <= %llu <= %llu? ", ackno_end_rl, ap->dccpap_ack_seqno, ackno);
748 if (between48(ap
->dccpap_ack_seqno
, ackno_end_rl
, ackno
)) {
749 const u8 state
= (*vector
& DCCP_ACKPKTS_STATE_MASK
) >> 6;
750 // dccp_pr_debug_cat("yes\n");
752 if (state
!= DCCP_ACKPKTS_STATE_NOT_RECEIVED
) {
754 struct dccp_sock
*dp
= dccp_sk(sk
);
755 const char *debug_prefix
= dp
->dccps_role
== DCCP_ROLE_CLIENT
? "CLIENT rx ack: " :
758 dccp_pr_debug("%sACK vector 0, len=%d, ack_seqno=%llu, ack_ackno=%llu, ACKED!\n",
761 ap
->dccpap_ack_seqno
,
763 ap
->dccpap_ack_ackno
);
764 dccp_ackpkts_trow_away_ack_record(ap
);
767 * If dccpap_ack_seqno was not received, no problem we'll
768 * send another ACK vector.
770 ap
->dccpap_ack_seqno
= DCCP_MAX_SEQNO
+ 1;
773 // dccp_pr_debug_cat("no\n");
775 dccp_set_seqno(&ackno
, ackno_end_rl
- 1);