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",
122 debug_prefix
, len
, DCCP_SKB_CB(skb
)->dccpd_ack_seq
);
123 dccp_ackvector_print(DCCP_SKB_CB(skb
)->dccpd_ack_seq
,
125 dccp_ackpkts_check_rcv_ackvector(dp
->dccps_hc_rx_ackpkts
, sk
,
126 DCCP_SKB_CB(skb
)->dccpd_ack_seq
,
129 case DCCPO_TIMESTAMP
:
131 goto out_invalid_option
;
133 opt_recv
->dccpor_timestamp
= ntohl(*(u32
*)value
);
135 dp
->dccps_timestamp_echo
= opt_recv
->dccpor_timestamp
;
136 dp
->dccps_timestamp_time
= jiffies
;
138 dccp_pr_debug("%sTIMESTAMP=%u, ackno=%llu\n",
139 debug_prefix
, opt_recv
->dccpor_timestamp
,
140 DCCP_SKB_CB(skb
)->dccpd_ack_seq
);
142 case DCCPO_TIMESTAMP_ECHO
:
143 if (len
< 4 || len
> 8)
144 goto out_invalid_option
;
146 opt_recv
->dccpor_timestamp_echo
= ntohl(*(u32
*)value
);
148 dccp_pr_debug("%sTIMESTAMP_ECHO=%u, len=%d, ackno=%llu, diff=%u\n",
149 debug_prefix
, opt_recv
->dccpor_timestamp_echo
,
150 len
+ 2, DCCP_SKB_CB(skb
)->dccpd_ack_seq
,
151 tcp_time_stamp
- opt_recv
->dccpor_timestamp_echo
);
153 opt_recv
->dccpor_elapsed_time
= dccp_decode_value_var(value
+ 4, len
- 4);
154 dccp_pr_debug("%sTIMESTAMP_ECHO ELAPSED_TIME=%d\n", debug_prefix
,
155 opt_recv
->dccpor_elapsed_time
);
157 case DCCPO_ELAPSED_TIME
:
159 goto out_invalid_option
;
161 if (pkt_type
== DCCP_PKT_DATA
)
163 opt_recv
->dccpor_elapsed_time
= dccp_decode_value_var(value
, len
);
164 dccp_pr_debug("%sELAPSED_TIME=%d\n", debug_prefix
,
165 opt_recv
->dccpor_elapsed_time
);
168 * From draft-ietf-dccp-spec-11.txt:
170 * Option numbers 128 through 191 are for options sent from the HC-
171 * Sender to the HC-Receiver; option numbers 192 through 255 are for
172 * options sent from the HC-Receiver to the HC-Sender.
175 const u16 idx
= value
- options
;
177 if (ccid_hc_rx_parse_options(dp
->dccps_hc_rx_ccid
, sk
, opt
, len
, idx
, value
) != 0)
178 goto out_invalid_option
;
182 const u16 idx
= value
- options
;
184 if (ccid_hc_tx_parse_options(dp
->dccps_hc_tx_ccid
, sk
, opt
, len
, idx
, value
) != 0)
185 goto out_invalid_option
;
189 pr_info("DCCP(%p): option %d(len=%d) not implemented, ignoring\n",
198 DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT
);
199 DCCP_SKB_CB(skb
)->dccpd_reset_code
= DCCP_RESET_CODE_OPTION_ERROR
;
200 pr_info("DCCP(%p): invalid option %d, len=%d\n", sk
, opt
, len
);
204 static void dccp_encode_value_var(const u32 value
, unsigned char *to
,
205 const unsigned int len
)
208 *to
++ = (value
& 0xFF000000) >> 24;
210 *to
++ = (value
& 0xFF0000) >> 16;
212 *to
++ = (value
& 0xFF00) >> 8;
214 *to
++ = (value
& 0xFF);
217 static inline int dccp_ndp_len(const int ndp
)
219 return likely(ndp
<= 0xFF) ? 1 : ndp
<= 0xFFFF ? 2 : 3;
222 void dccp_insert_option(struct sock
*sk
, struct sk_buff
*skb
,
223 const unsigned char option
,
224 const void *value
, const unsigned char len
)
228 if (DCCP_SKB_CB(skb
)->dccpd_opt_len
+ len
+ 2 > DCCP_MAX_OPT_LEN
) {
229 LIMIT_NETDEBUG(pr_info("DCCP: packet too small to insert %d option!\n", option
));
233 DCCP_SKB_CB(skb
)->dccpd_opt_len
+= len
+ 2;
235 to
= skb_push(skb
, len
+ 2);
239 memcpy(to
, value
, len
);
242 EXPORT_SYMBOL_GPL(dccp_insert_option
);
244 static void dccp_insert_option_ndp(struct sock
*sk
, struct sk_buff
*skb
)
246 struct dccp_sock
*dp
= dccp_sk(sk
);
247 int ndp
= dp
->dccps_ndp_count
;
249 if (dccp_non_data_packet(skb
))
250 ++dp
->dccps_ndp_count
;
252 dp
->dccps_ndp_count
= 0;
256 const int ndp_len
= dccp_ndp_len(ndp
);
257 const int len
= ndp_len
+ 2;
259 if (DCCP_SKB_CB(skb
)->dccpd_opt_len
+ len
> DCCP_MAX_OPT_LEN
)
262 DCCP_SKB_CB(skb
)->dccpd_opt_len
+= len
;
264 ptr
= skb_push(skb
, len
);
265 *ptr
++ = DCCPO_NDP_COUNT
;
267 dccp_encode_value_var(ndp
, ptr
, ndp_len
);
271 static inline int dccp_elapsed_time_len(const u32 elapsed_time
)
273 return elapsed_time
== 0 ? 0 :
274 elapsed_time
<= 0xFF ? 1 :
275 elapsed_time
<= 0xFFFF ? 2 :
276 elapsed_time
<= 0xFFFFFF ? 3 : 4;
279 void dccp_insert_option_elapsed_time(struct sock
*sk
,
284 struct dccp_sock
*dp
= dccp_sk(sk
);
285 const char *debug_prefix
= dp
->dccps_role
== DCCP_ROLE_CLIENT
? "CLIENT TX opt: " :
288 const int elapsed_time_len
= dccp_elapsed_time_len(elapsed_time
);
289 const int len
= 2 + elapsed_time_len
;
292 /* If elapsed_time == 0... */
293 if (elapsed_time_len
== 2)
296 if (DCCP_SKB_CB(skb
)->dccpd_opt_len
+ len
> DCCP_MAX_OPT_LEN
) {
297 LIMIT_NETDEBUG(pr_info("DCCP: packet too small to insert elapsed time!\n"));
301 DCCP_SKB_CB(skb
)->dccpd_opt_len
+= len
;
303 to
= skb_push(skb
, len
);
304 *to
++ = DCCPO_ELAPSED_TIME
;
307 dccp_encode_value_var(elapsed_time
, to
, elapsed_time_len
);
309 dccp_pr_debug("%sELAPSED_TIME=%u, len=%d, seqno=%llu\n",
310 debug_prefix
, elapsed_time
,
311 len
, DCCP_SKB_CB(skb
)->dccpd_seq
);
314 EXPORT_SYMBOL(dccp_insert_option_elapsed_time
);
316 static void dccp_insert_option_ack_vector(struct sock
*sk
, struct sk_buff
*skb
)
318 struct dccp_sock
*dp
= dccp_sk(sk
);
320 const char *debug_prefix
= dp
->dccps_role
== DCCP_ROLE_CLIENT
? "CLIENT TX opt: " :
323 struct dccp_ackpkts
*ap
= dp
->dccps_hc_rx_ackpkts
;
324 int len
= ap
->dccpap_buf_vector_len
+ 2;
325 const u32 elapsed_time
= jiffies_to_usecs(jiffies
- ap
->dccpap_time
) / 10;
326 unsigned char *to
, *from
;
328 if (elapsed_time
!= 0)
329 dccp_insert_option_elapsed_time(sk
, skb
, elapsed_time
);
331 if (DCCP_SKB_CB(skb
)->dccpd_opt_len
+ len
> DCCP_MAX_OPT_LEN
) {
332 LIMIT_NETDEBUG(pr_info("DCCP: packet too small to insert ACK Vector!\n"));
337 * XXX: now we have just one ack vector sent record, so
338 * we have to wait for it to be cleared.
340 * Of course this is not acceptable, but this is just for
343 if (ap
->dccpap_ack_seqno
!= DCCP_MAX_SEQNO
+ 1)
346 DCCP_SKB_CB(skb
)->dccpd_opt_len
+= len
;
348 to
= skb_push(skb
, len
);
349 *to
++ = DCCPO_ACK_VECTOR_0
;
352 len
= ap
->dccpap_buf_vector_len
;
353 from
= ap
->dccpap_buf
+ ap
->dccpap_buf_head
;
355 /* Check if buf_head wraps */
356 if (ap
->dccpap_buf_head
+ len
> ap
->dccpap_buf_len
) {
357 const unsigned int tailsize
= ap
->dccpap_buf_len
- ap
->dccpap_buf_head
;
359 memcpy(to
, from
, tailsize
);
362 from
= ap
->dccpap_buf
;
365 memcpy(to
, from
, len
);
367 * From draft-ietf-dccp-spec-11.txt:
369 * For each acknowledgement it sends, the HC-Receiver will add an
370 * acknowledgement record. ack_seqno will equal the HC-Receiver
371 * sequence number it used for the ack packet; ack_ptr will equal
372 * buf_head; ack_ackno will equal buf_ackno; and ack_nonce will equal
375 * This implemention uses just one ack record for now.
377 ap
->dccpap_ack_seqno
= DCCP_SKB_CB(skb
)->dccpd_seq
;
378 ap
->dccpap_ack_ptr
= ap
->dccpap_buf_head
;
379 ap
->dccpap_ack_ackno
= ap
->dccpap_buf_ackno
;
380 ap
->dccpap_ack_nonce
= ap
->dccpap_buf_nonce
;
381 ap
->dccpap_ack_vector_len
= ap
->dccpap_buf_vector_len
;
383 dccp_pr_debug("%sACK Vector 0, len=%d, ack_seqno=%llu, ack_ackno=%llu\n",
384 debug_prefix
, ap
->dccpap_ack_vector_len
,
385 ap
->dccpap_ack_seqno
, ap
->dccpap_ack_ackno
);
388 static inline void dccp_insert_option_timestamp(struct sock
*sk
, struct sk_buff
*skb
)
390 const u32 now
= htonl(tcp_time_stamp
);
391 dccp_insert_option(sk
, skb
, DCCPO_TIMESTAMP
, &now
, sizeof(now
));
394 static void dccp_insert_option_timestamp_echo(struct sock
*sk
, struct sk_buff
*skb
)
396 struct dccp_sock
*dp
= dccp_sk(sk
);
398 const char *debug_prefix
= dp
->dccps_role
== DCCP_ROLE_CLIENT
? "CLIENT TX opt: " :
402 const u32 elapsed_time
= jiffies_to_usecs(jiffies
- dp
->dccps_timestamp_time
) / 10;
403 const int elapsed_time_len
= dccp_elapsed_time_len(elapsed_time
);
404 const int len
= 6 + elapsed_time_len
;
407 if (DCCP_SKB_CB(skb
)->dccpd_opt_len
+ len
> DCCP_MAX_OPT_LEN
) {
408 LIMIT_NETDEBUG(pr_info("DCCP: packet too small to insert timestamp echo!\n"));
412 DCCP_SKB_CB(skb
)->dccpd_opt_len
+= len
;
414 to
= skb_push(skb
, len
);
415 *to
++ = DCCPO_TIMESTAMP_ECHO
;
418 tstamp_echo
= htonl(dp
->dccps_timestamp_echo
);
419 memcpy(to
, &tstamp_echo
, 4);
421 dccp_encode_value_var(elapsed_time
, to
, elapsed_time_len
);
423 dccp_pr_debug("%sTIMESTAMP_ECHO=%u, len=%d, seqno=%llu\n",
424 debug_prefix
, dp
->dccps_timestamp_echo
,
425 len
, DCCP_SKB_CB(skb
)->dccpd_seq
);
427 dp
->dccps_timestamp_echo
= 0;
428 dp
->dccps_timestamp_time
= 0;
431 void dccp_insert_options(struct sock
*sk
, struct sk_buff
*skb
)
433 struct dccp_sock
*dp
= dccp_sk(sk
);
435 DCCP_SKB_CB(skb
)->dccpd_opt_len
= 0;
437 if (dp
->dccps_options
.dccpo_send_ndp_count
)
438 dccp_insert_option_ndp(sk
, skb
);
440 if (!dccp_packet_without_ack(skb
)) {
441 if (dp
->dccps_options
.dccpo_send_ack_vector
&&
442 dp
->dccps_hc_rx_ackpkts
->dccpap_buf_ackno
!= DCCP_MAX_SEQNO
+ 1)
443 dccp_insert_option_ack_vector(sk
, skb
);
445 dccp_insert_option_timestamp(sk
, skb
);
446 if (dp
->dccps_timestamp_echo
!= 0)
447 dccp_insert_option_timestamp_echo(sk
, skb
);
450 ccid_hc_rx_insert_options(dp
->dccps_hc_rx_ccid
, sk
, skb
);
451 ccid_hc_tx_insert_options(dp
->dccps_hc_tx_ccid
, sk
, skb
);
453 /* XXX: insert other options when appropriate */
455 if (DCCP_SKB_CB(skb
)->dccpd_opt_len
!= 0) {
456 /* The length of all options has to be a multiple of 4 */
457 int padding
= DCCP_SKB_CB(skb
)->dccpd_opt_len
% 4;
460 padding
= 4 - padding
;
461 memset(skb_push(skb
, padding
), 0, padding
);
462 DCCP_SKB_CB(skb
)->dccpd_opt_len
+= padding
;
467 struct dccp_ackpkts
*dccp_ackpkts_alloc(unsigned int len
, int priority
)
469 struct dccp_ackpkts
*ap
= kmalloc(sizeof(*ap
) + len
, priority
);
473 memset(ap
->dccpap_buf
, 0xFF, len
);
475 ap
->dccpap_buf_len
= len
;
476 ap
->dccpap_buf_head
= ap
->dccpap_buf_tail
= ap
->dccpap_buf_len
- 1;
477 ap
->dccpap_buf_ackno
= ap
->dccpap_ack_ackno
= ap
->dccpap_ack_seqno
= DCCP_MAX_SEQNO
+ 1;
478 ap
->dccpap_buf_nonce
= ap
->dccpap_buf_nonce
= 0;
479 ap
->dccpap_ack_ptr
= 0;
481 ap
->dccpap_buf_vector_len
= ap
->dccpap_ack_vector_len
= 0;
487 void dccp_ackpkts_free(struct dccp_ackpkts
*ap
)
491 memset(ap
, 0xFF, sizeof(*ap
) + ap
->dccpap_buf_len
);
497 static inline u8
dccp_ackpkts_state(const struct dccp_ackpkts
*ap
,
498 const unsigned int index
)
500 return ap
->dccpap_buf
[index
] & DCCP_ACKPKTS_STATE_MASK
;
503 static inline u8
dccp_ackpkts_len(const struct dccp_ackpkts
*ap
,
504 const unsigned int index
)
506 return ap
->dccpap_buf
[index
] & DCCP_ACKPKTS_LEN_MASK
;
510 * If several packets are missing, the HC-Receiver may prefer to enter multiple
511 * bytes with run length 0, rather than a single byte with a larger run length;
512 * this simplifies table updates if one of the missing packets arrives.
514 static inline int dccp_ackpkts_set_buf_head_state(struct dccp_ackpkts
*ap
,
515 const unsigned int packets
,
516 const unsigned char state
)
519 signed long new_head
;
521 if (ap
->dccpap_buf_vector_len
+ packets
> ap
->dccpap_buf_len
)
525 new_head
= ap
->dccpap_buf_head
- packets
;
529 memset(ap
->dccpap_buf
, DCCP_ACKPKTS_STATE_NOT_RECEIVED
,
533 new_head
+= ap
->dccpap_buf_len
;
536 ap
->dccpap_buf_head
= new_head
;
539 memset(ap
->dccpap_buf
+ ap
->dccpap_buf_head
+ 1,
540 DCCP_ACKPKTS_STATE_NOT_RECEIVED
, gap
);
542 ap
->dccpap_buf
[ap
->dccpap_buf_head
] = state
;
543 ap
->dccpap_buf_vector_len
+= packets
;
548 * Implements the draft-ietf-dccp-spec-11.txt Appendix A
550 int dccp_ackpkts_add(struct dccp_ackpkts
*ap
, u64 ackno
, u8 state
)
553 * Check at the right places if the buffer is full, if it is, tell the
554 * caller to start dropping packets till the HC-Sender acks our ACK
555 * vectors, when we will free up space in dccpap_buf.
557 * We may well decide to do buffer compression, etc, but for now lets
562 * Of course, the circular buffer may overflow, either when the HC-
563 * Sender is sending data at a very high rate, when the HC-Receiver's
564 * acknowledgements are not reaching the HC-Sender, or when the HC-
565 * Sender is forgetting to acknowledge those acks (so the HC-Receiver
566 * is unable to clean up old state). In this case, the HC-Receiver
567 * should either compress the buffer (by increasing run lengths when
568 * possible), transfer its state to a larger buffer, or, as a last
569 * resort, drop all received packets, without processing them
570 * whatsoever, until its buffer shrinks again.
573 /* See if this is the first ackno being inserted */
574 if (ap
->dccpap_buf_vector_len
== 0) {
575 ap
->dccpap_buf
[ap
->dccpap_buf_head
] = state
;
576 ap
->dccpap_buf_vector_len
= 1;
577 } else if (after48(ackno
, ap
->dccpap_buf_ackno
)) {
578 const u64 delta
= dccp_delta_seqno(ap
->dccpap_buf_ackno
, ackno
);
581 * Look if the state of this packet is the same as the previous ackno
582 * and if so if we can bump the head len.
585 dccp_ackpkts_state(ap
, ap
->dccpap_buf_head
) == state
&&
586 dccp_ackpkts_len(ap
, ap
->dccpap_buf_head
) < DCCP_ACKPKTS_LEN_MASK
)
587 ap
->dccpap_buf
[ap
->dccpap_buf_head
]++;
588 else if (dccp_ackpkts_set_buf_head_state(ap
, delta
, state
))
594 * When a packet with Sequence Number S arrives, and S <= buf_ackno,
595 * the HC-Receiver will scan the table for the byte corresponding to S.
596 * (Indexing structures could reduce the complexity of this scan.)
598 u64 delta
= dccp_delta_seqno(ackno
, ap
->dccpap_buf_ackno
);
599 unsigned int index
= ap
->dccpap_buf_head
;
602 const u8 len
= dccp_ackpkts_len(ap
, index
);
603 const u8 state
= dccp_ackpkts_state(ap
, index
);
605 * valid packets not yet in dccpap_buf have a reserved entry, with
608 if (state
== DCCP_ACKPKTS_STATE_NOT_RECEIVED
&&
609 len
== 0 && delta
== 0) { /* Found our reserved seat! */
610 dccp_pr_debug("Found %llu reserved seat!\n", ackno
);
611 ap
->dccpap_buf
[index
] = state
;
614 /* len == 0 means one packet */
619 if (++index
== ap
->dccpap_buf_len
)
624 ap
->dccpap_buf_ackno
= ackno
;
625 ap
->dccpap_time
= jiffies
;
628 dccp_ackpkts_print(ap
);
632 /* Duplicate packet */
633 dccp_pr_debug("Received a dup or already considered lost packet: %llu\n", ackno
);
638 void dccp_ackvector_print(const u64 ackno
, const unsigned char *vector
, int len
)
643 printk("ACK vector len=%d, ackno=%llu |", len
, ackno
);
646 const u8 state
= (*vector
& DCCP_ACKPKTS_STATE_MASK
) >> 6;
647 const u8 rl
= (*vector
& DCCP_ACKPKTS_LEN_MASK
);
649 printk("%d,%d|", state
, rl
);
656 void dccp_ackpkts_print(const struct dccp_ackpkts
*ap
)
658 dccp_ackvector_print(ap
->dccpap_buf_ackno
,
659 ap
->dccpap_buf
+ ap
->dccpap_buf_head
,
660 ap
->dccpap_buf_vector_len
);
664 static void dccp_ackpkts_trow_away_ack_record(struct dccp_ackpkts
*ap
)
667 * As we're keeping track of the ack vector size
668 * (dccpap_buf_vector_len) and the sent ack vector size
669 * (dccpap_ack_vector_len) we don't need dccpap_buf_tail at all, but
670 * keep this code here as in the future we'll implement a vector of ack
671 * records, as suggested in draft-ietf-dccp-spec-11.txt Appendix A. -acme
674 ap
->dccpap_buf_tail
= ap
->dccpap_ack_ptr
+ 1;
675 if (ap
->dccpap_buf_tail
>= ap
->dccpap_buf_len
)
676 ap
->dccpap_buf_tail
-= ap
->dccpap_buf_len
;
678 ap
->dccpap_buf_vector_len
-= ap
->dccpap_ack_vector_len
;
681 void dccp_ackpkts_check_rcv_ackno(struct dccp_ackpkts
*ap
, struct sock
*sk
,
684 /* Check if we actually sent an ACK vector */
685 if (ap
->dccpap_ack_seqno
== DCCP_MAX_SEQNO
+ 1)
688 if (ackno
== ap
->dccpap_ack_seqno
) {
690 struct dccp_sock
*dp
= dccp_sk(sk
);
691 const char *debug_prefix
= dp
->dccps_role
== DCCP_ROLE_CLIENT
? "CLIENT rx ack: " :
694 dccp_pr_debug("%sACK packet 0, len=%d, ack_seqno=%llu, ack_ackno=%llu, ACKED!\n",
696 ap
->dccpap_ack_seqno
, ap
->dccpap_ack_ackno
);
697 dccp_ackpkts_trow_away_ack_record(ap
);
698 ap
->dccpap_ack_seqno
= DCCP_MAX_SEQNO
+ 1;
702 static void dccp_ackpkts_check_rcv_ackvector(struct dccp_ackpkts
*ap
,
703 struct sock
*sk
, u64 ackno
,
704 const unsigned char len
,
705 const unsigned char *vector
)
709 /* Check if we actually sent an ACK vector */
710 if (ap
->dccpap_ack_seqno
== DCCP_MAX_SEQNO
+ 1)
713 * We're in the receiver half connection, so if the received an ACK vector
714 * ackno (e.g. 50) before dccpap_ack_seqno (e.g. 52), we're not interested.
716 * Extra explanation with example:
718 * if we received an ACK vector with ackno 50, it can only be acking
719 * 50, 49, 48, etc, not 52 (the seqno for the ACK vector we sent).
721 // dccp_pr_debug("is %llu < %llu? ", ackno, ap->dccpap_ack_seqno);
722 if (before48(ackno
, ap
->dccpap_ack_seqno
)) {
723 // dccp_pr_debug_cat("yes\n");
726 // dccp_pr_debug_cat("no\n");
730 const u8 rl
= (*vector
& DCCP_ACKPKTS_LEN_MASK
);
733 dccp_set_seqno(&ackno_end_rl
, ackno
- rl
);
735 // dccp_pr_debug("is %llu <= %llu <= %llu? ", ackno_end_rl, ap->dccpap_ack_seqno, ackno);
736 if (between48(ap
->dccpap_ack_seqno
, ackno_end_rl
, ackno
)) {
737 const u8 state
= (*vector
& DCCP_ACKPKTS_STATE_MASK
) >> 6;
738 // dccp_pr_debug_cat("yes\n");
740 if (state
!= DCCP_ACKPKTS_STATE_NOT_RECEIVED
) {
742 struct dccp_sock
*dp
= dccp_sk(sk
);
743 const char *debug_prefix
= dp
->dccps_role
== DCCP_ROLE_CLIENT
? "CLIENT rx ack: " :
746 dccp_pr_debug("%sACK vector 0, len=%d, ack_seqno=%llu, ack_ackno=%llu, ACKED!\n",
748 ap
->dccpap_ack_seqno
, ap
->dccpap_ack_ackno
);
749 dccp_ackpkts_trow_away_ack_record(ap
);
752 * If dccpap_ack_seqno was not received, no problem we'll
753 * send another ACK vector.
755 ap
->dccpap_ack_seqno
= DCCP_MAX_SEQNO
+ 1;
758 // dccp_pr_debug_cat("no\n");
760 dccp_set_seqno(&ackno
, ackno_end_rl
- 1);