[DCCPv6]: Choose a genuine initial sequence number

This
	* resolves a FIXME - DCCPv6 connections started all with
	  an initial sequence number of 1;
	* provides a redirection `secure_dccpv6_sequence_number'
	  in case the init_sequence_v6 code should be updated later;
	* concentrates the update of S.GAR into dccp_connect_init();
	* removes a duplicate dccp_update_gss() in ipv4.c;
	* uses inet->dport instead of usin->sin_port, due to the
	  following assignment in dccp_v4_connect():
 		inet->dport = usin->sin_port;

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>

3 files changed, 23 insertions, 20 deletions

diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index b56a2fa2694a..bc400b2ba25e 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -113,13 +113,8 @@ int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
         /* OK, now commit destination to socket.  */
         sk_setup_caps(sk, &rt->u.dst);
 
-        dp->dccps_gar =
-                dp->dccps_iss = secure_dccp_sequence_number(inet->saddr,
-                                                            inet->daddr,
-                                                            inet->sport,
-                                                            usin->sin_port);
-        dccp_update_gss(sk, dp->dccps_iss);
-
+        dp->dccps_iss = secure_dccp_sequence_number(inet->saddr, inet->daddr,
+                                                    inet->sport, inet->dport);
         inet->id = dp->dccps_iss ^ jiffies;
 
         err = dccp_connect(sk);
diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c
index a08af75ddc9e..8d6ddb6389a7 100644
--- a/net/dccp/ipv6.c
+++ b/net/dccp/ipv6.c
@@ -76,12 +76,19 @@ static inline void dccp_v6_send_check(struct sock *sk, int unused_value,
         dh->dccph_checksum = dccp_v6_csum_finish(skb, &np->saddr, &np->daddr);
 }
 
-static inline __u32 dccp_v6_init_sequence(const struct sk_buff *skb)
+static inline __u32 secure_dccpv6_sequence_number(__u32 *saddr, __u32 *daddr,
+                                                  __u16 sport, __u16 dport   )
 {
-        return secure_tcpv6_sequence_number(skb->nh.ipv6h->daddr.s6_addr32,
-                                            skb->nh.ipv6h->saddr.s6_addr32,
-                                            dccp_hdr(skb)->dccph_dport,
-                                            dccp_hdr(skb)->dccph_sport     );
+        return secure_tcpv6_sequence_number(saddr, daddr, sport, dport);
+}
+
+static inline __u32 dccp_v6_init_sequence(struct sk_buff *skb)
+{
+        return secure_dccpv6_sequence_number(skb->nh.ipv6h->daddr.s6_addr32,
+                                             skb->nh.ipv6h->saddr.s6_addr32,
+                                             dccp_hdr(skb)->dccph_dport,
+                                             dccp_hdr(skb)->dccph_sport     );
+
 }
 
 static void dccp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
@@ -1065,13 +1072,10 @@ static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
         err = inet6_hash_connect(&dccp_death_row, sk);
         if (err)
                 goto late_failure;
-        /* FIXME */
-#if 0
-        dp->dccps_gar = secure_dccp_v6_sequence_number(np->saddr.s6_addr32,
-                                                       np->daddr.s6_addr32,
-                                                       inet->sport,
-                                                       inet->dport);
-#endif
+
+        dp->dccps_iss = secure_dccpv6_sequence_number(np->saddr.s6_addr32,
+                                                      np->daddr.s6_addr32,
+                                                      inet->sport, inet->dport);
         err = dccp_connect(sk);
         if (err)
                 goto late_failure;
diff --git a/net/dccp/output.c b/net/dccp/output.c
index 08ee5547a2f2..0994b13f0f15 100644
--- a/net/dccp/output.c
+++ b/net/dccp/output.c
@@ -448,7 +448,6 @@ static inline void dccp_connect_init(struct sock *sk)
         
         dccp_sync_mss(sk, dst_mtu(dst));
 
-        dccp_update_gss(sk, dp->dccps_iss);
         /*
          * SWL and AWL are initially adjusted so that they are not less than
          * the initial Sequence Numbers received and sent, respectively:
@@ -457,8 +456,13 @@ static inline void dccp_connect_init(struct sock *sk)
          * These adjustments MUST be applied only at the beginning of the
          * connection.
          */
+        dccp_update_gss(sk, dp->dccps_iss);
         dccp_set_seqno(&dp->dccps_awl, max48(dp->dccps_awl, dp->dccps_iss));
 
+        /* S.GAR - greatest valid acknowledgement number received on a non-Sync;
+         *         initialized to S.ISS (sec. 8.5)                            */
+        dp->dccps_gar = dp->dccps_iss;
+
         icsk->icsk_retransmits = 0;
         init_timer(&dp->dccps_xmit_timer);
         dp->dccps_xmit_timer.data = (unsigned long)sk;