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[DCCP]: Fix default sequence window size
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When using the default sequence window size (100) I got the following in
my logs:

Jun 22 14:24:09 localhost kernel: [ 1492.114775] DCCP: Step 6 failed for
DATA packet, (LSWL(6279674225) <= P.seqno(6279674749) <=
S.SWH(6279674324)) and (P.ackno doesn't exist or LAWL(18798206530) <=
P.ackno(1125899906842620) <= S.AWH(18798206548), sending SYNC...
Jun 22 14:24:09 localhost kernel: [ 1492.115147] DCCP: Step 6 failed for
DATA packet, (LSWL(6279674225) <= P.seqno(6279674750) <=
S.SWH(6279674324)) and (P.ackno doesn't exist or LAWL(18798206530) <=
P.ackno(1125899906842620) <= S.AWH(18798206549), sending SYNC...

I went to alter the default sysctl and it didn't take for new sockets.
Below patch fixes this.

I think the default is too low but it is what the DCCP spec specifies.

As a side effect of this my rx speed using iperf goes from about 2.8 Mbits/sec
to 3.5. This is still far too slow but it is a step in the right direction.

Compile tested only for IPv6 but not particularly complex change.

Signed off by: Ian McDonald <[email protected]>
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
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imcdnzl authored and David S. Miller committed Jul 24, 2006
1 parent 8fdf679 commit 4b79f0a
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Showing 4 changed files with 7 additions and 4 deletions.
2 changes: 2 additions & 0 deletions net/dccp/feat.h
Original file line number Diff line number Diff line change
Expand Up @@ -26,4 +26,6 @@ extern void dccp_feat_clean(struct dccp_minisock *dmsk);
extern int dccp_feat_clone(struct sock *oldsk, struct sock *newsk);
extern int dccp_feat_init(struct dccp_minisock *dmsk);

extern int dccp_feat_default_sequence_window;

#endif /* _DCCP_FEAT_H */
3 changes: 1 addition & 2 deletions net/dccp/ipv4.c
Original file line number Diff line number Diff line change
Expand Up @@ -504,8 +504,7 @@ int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
ireq = inet_rsk(req);
ireq->loc_addr = daddr;
ireq->rmt_addr = saddr;
req->rcv_wnd = 100; /* Fake, option parsing will get the
right value */
req->rcv_wnd = dccp_feat_default_sequence_window;
ireq->opt = NULL;

/*
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4 changes: 2 additions & 2 deletions net/dccp/ipv6.c
Original file line number Diff line number Diff line change
Expand Up @@ -31,6 +31,7 @@

#include "dccp.h"
#include "ipv6.h"
#include "feat.h"

/* Socket used for sending RSTs and ACKs */
static struct socket *dccp_v6_ctl_socket;
Expand Down Expand Up @@ -707,8 +708,7 @@ static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
ireq = inet_rsk(req);
ipv6_addr_copy(&ireq6->rmt_addr, &skb->nh.ipv6h->saddr);
ipv6_addr_copy(&ireq6->loc_addr, &skb->nh.ipv6h->daddr);
req->rcv_wnd = 100; /* Fake, option parsing will get the
right value */
req->rcv_wnd = dccp_feat_default_sequence_window;
ireq6->pktopts = NULL;

if (ipv6_opt_accepted(sk, skb) ||
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2 changes: 2 additions & 0 deletions net/dccp/options.c
Original file line number Diff line number Diff line change
Expand Up @@ -29,6 +29,8 @@ int dccp_feat_default_ack_ratio = DCCPF_INITIAL_ACK_RATIO;
int dccp_feat_default_send_ack_vector = DCCPF_INITIAL_SEND_ACK_VECTOR;
int dccp_feat_default_send_ndp_count = DCCPF_INITIAL_SEND_NDP_COUNT;

EXPORT_SYMBOL_GPL(dccp_feat_default_sequence_window);

void dccp_minisock_init(struct dccp_minisock *dmsk)
{
dmsk->dccpms_sequence_window = dccp_feat_default_sequence_window;
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