Subject: Re: 2.6.27 [BUG-FIX] [PATCH 1/1] dccp: Port redirection supportfor DCCP

From: KOVACS Krisztian <[email-masked]>
Date: Sat, 18 Oct 2008 11:48:14 +0200

Hi,

On Saturday 18 October 2008, Gerrit Renker wrote:
> Commit a3116ac5c216fc3c145906a46df9ce542ff7dcf2 from 1st October ("tcp:
> Port redirection support for TCP") broke DCCP skb lookup by changing
> inet_csk_clone, which is used by DCCP to generate the child socket
> after the handshake.
>
> This patch updates DCCP to use 'loc_port' instead of 'sport', which
> fixes the problem, and thus inheriting port redirection support via the
> new interface.
>
> Signed-off-by: Gerrit Renker <[email-masked]>

Yeah, Gerrit and me simultaneously found this to be the culprit.
One minor comment below.

> ---
>  net/dccp/ipv6.c      |    2 +-
>  net/dccp/minisocks.c |    1 +
>  net/dccp/output.c    |    2 +-
>  3 files changed, 3 insertions(+), 2 deletions(-)
>
> --- a/net/dccp/minisocks.c
> +++ b/net/dccp/minisocks.c
> @@ -309,6 +309,7 @@ void dccp_reqsk_init(struct request_sock
>  	struct dccp_request_sock *dreq = dccp_rsk(req);
>
>  	inet_rsk(req)->rmt_port	  = dccp_hdr(skb)->dccph_sport;
> +	inet_rsk(req)->loc_port	  = dccp_hdr(skb)->dccph_dport;
>  	inet_rsk(req)->acked	  = 0;
>  	req->rcv_wnd		  = sysctl_dccp_feat_sequence_window;
>  	dreq->dreq_timestamp_echo = 0;
> --- a/net/dccp/ipv6.c
> +++ b/net/dccp/ipv6.c
> @@ -259,7 +259,7 @@ static int dccp_v6_send_response(struct
>  	fl.fl6_flowlabel = 0;
>  	fl.oif = ireq6->iif;
>  	fl.fl_ip_dport = inet_rsk(req)->rmt_port;
> -	fl.fl_ip_sport = inet_sk(sk)->sport;
> +	fl.fl_ip_sport = inet_rsk(req)->loc_port;
>  	security_req_classify_flow(req, &fl);
>
>  	opt = np->opt;
> --- a/net/dccp/output.c
> +++ b/net/dccp/output.c
> @@ -347,7 +347,7 @@ struct sk_buff *dccp_make_response(struc
>  	/* Build and checksum header */
>  	dh = dccp_zeroed_hdr(skb, dccp_header_size);
>
> -	dh->dccph_sport	= inet_sk(sk)->sport;
> +	dh->dccph_sport	= inet_rsk(req)->loc_port;
>  	dh->dccph_dport	= inet_rsk(req)->rmt_port;
>  	dh->dccph_doff	= (dccp_header_size +
>  			   DCCP_SKB_CB(skb)->dccpd_opt_len) / 4;

I think we're still missing this one:

diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c
index 1106278..aa00cdd 100644
--- a/net/dccp/ipv6.c
+++ b/net/dccp/ipv6.c
@@ -558,7 +558,7 @@ static struct sock *dccp_v6_request_recv_sock(struct sock *sk,
 		ipv6_addr_copy(&fl.fl6_src, &ireq6->loc_addr);
 		fl.oif = sk->sk_bound_dev_if;
 		fl.fl_ip_dport = inet_rsk(req)->rmt_port;
-		fl.fl_ip_sport = inet_sk(sk)->sport;
+		fl.fl_ip_sport = inet_rsk(req)->loc_port;
 		security_sk_classify_flow(sk, &fl);
 
 		if (ip6_dst_lookup(sk, &dst, &fl))

What do you think?

-- 
KOVACS Krisztian