[DCCP]: Retrieve packet sequence number for error reporting

This fixes a problem when analysing erroneous packets in dccp_v{4,6}_err:
* dccp_hdr_seq currently takes an skb
* however, the transport headers in the skb are shifted, due to the
  preceding IPv4/v6 header.
Fixed for v4 and v6 by changing dccp_hdr_seq to take a struct dccp_hdr as
argument. Verified that the correct sequence number is now reported in the
error handler.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

2 files changed, 4 insertions, 4 deletions

diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index 222549ab274a..3f1578db93e8 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -241,7 +241,7 @@ static void dccp_v4_err(struct sk_buff *skb, u32 info)
                 goto out;
 
         dp = dccp_sk(sk);
-        seq = dccp_hdr_seq(skb);
+        seq = dccp_hdr_seq(dh);
         if (sk->sk_state != DCCP_LISTEN &&
             !between48(seq, dp->dccps_swl, dp->dccps_swh)) {
                 NET_INC_STATS_BH(LINUX_MIB_OUTOFWINDOWICMPS);
@@ -795,7 +795,7 @@ static int dccp_v4_rcv(struct sk_buff *skb)
 
         dh = dccp_hdr(skb);
 
-        DCCP_SKB_CB(skb)->dccpd_seq  = dccp_hdr_seq(skb);
+        DCCP_SKB_CB(skb)->dccpd_seq  = dccp_hdr_seq(dh);
         DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type;
 
         dccp_pr_debug("%8.8s "
diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c
index bbadd6681b83..62428ff137dd 100644
--- a/net/dccp/ipv6.c
+++ b/net/dccp/ipv6.c
@@ -173,7 +173,7 @@ static void dccp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 
         icmpv6_err_convert(type, code, &err);
 
-        seq = DCCP_SKB_CB(skb)->dccpd_seq;
+        seq = dccp_hdr_seq(dh);
         /* Might be for an request_sock */
         switch (sk->sk_state) {
                 struct request_sock *req, **prev;
@@ -787,7 +787,7 @@ static int dccp_v6_rcv(struct sk_buff *skb)
 
         dh = dccp_hdr(skb);
 
-        DCCP_SKB_CB(skb)->dccpd_seq  = dccp_hdr_seq(skb);
+        DCCP_SKB_CB(skb)->dccpd_seq  = dccp_hdr_seq(dh);
         DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type;
 
         if (dccp_packet_without_ack(skb))