dccp ccid-2: Algorithm to update buffer state
This provides a routine to consistently update the buffer state when the
peer acknowledges receipt of Ack Vectors; updating state in the list of Ack
Vectors as well as in the circular buffer.
While based on RFC 4340, several additional (and necessary) precautions were
added to protect the consistency of the buffer state. These additions are
essential, since analysis and experience showed that the basic algorithm was
insufficient for this task (which lead to problems that were hard to debug).
The algorithm now
* deals with HC-sender acknowledging to HC-receiver and vice versa,
* keeps track of the last unacknowledged but received seqno in tail_ackno,
* has special cases to reset the overflow condition when appropriate,
* is protected against receiving older information (would mess up buffer state).
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
diff --git a/net/dccp/options.c b/net/dccp/options.c
index 5adeeed..7743df0 100644
--- a/net/dccp/options.c
+++ b/net/dccp/options.c
@@ -54,7 +54,6 @@
struct dccp_sock *dp = dccp_sk(sk);
const struct dccp_hdr *dh = dccp_hdr(skb);
const u8 pkt_type = DCCP_SKB_CB(skb)->dccpd_type;
- u64 ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq;
unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb);
unsigned char *opt_ptr = options;
const unsigned char *opt_end = (unsigned char *)dh +
@@ -133,9 +132,8 @@
case DCCPO_ACK_VECTOR_1:
if (dccp_packet_without_ack(skb)) /* RFC 4340, 11.4 */
break;
- if (dp->dccps_hc_rx_ackvec != NULL &&
- dccp_ackvec_parse(sk, skb, &ackno, opt, value, len))
- goto out_invalid_option;
+ dccp_pr_debug("%s Ack Vector (len=%u)\n", dccp_role(sk),
+ len);
break;
case DCCPO_TIMESTAMP:
if (len != 4)