ipv6: Introduce ip6_flow_hdr() to fill version, tclass and flowlabel.

This is not only for readability but also for optimization.
What we do here is to build the 32bit word at the beginning of the ipv6
header (the "ip6_flow" virtual member of struct ip6_hdr in RFC3542) and
we do not need to read the tclass portion of the target buffer.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index 5af66b26ebdd6379ce34ae1a914c3c71a2ce5f32..fcbc6464b014255db736c95319897622662be367 100644 (file)
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -546,6 +546,15 @@ static inline int ipv6_addr_diff(const struct in6_addr *a1, const struct in6_add
 
 extern void ipv6_select_ident(struct frag_hdr *fhdr, struct rt6_info *rt);
 
+/*
+ *     Header manipulation
+ */
+static inline void ip6_flow_hdr(struct ipv6hdr *hdr, unsigned int tclass,
+                               __be32 flowlabel)
+{
+       *(__be32 *)hdr = ntohl(0x60000000 | (tclass << 20)) | flowlabel;
+}
+
 /*
  *     Prototypes exported by ipv6
  */

diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index c727e471275199ef27039f79b95755803435211a..db91fe3466a3c1dc02df7d2b864c6b17b1218cb1 100644 (file)
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -772,9 +772,7 @@ static netdev_tx_t ip6gre_xmit2(struct sk_buff *skb,
         *      Push down and install the IP header.
         */
        ipv6h = ipv6_hdr(skb);
-       *(__be32 *)ipv6h = fl6->flowlabel | htonl(0x60000000);
-       dsfield = INET_ECN_encapsulate(0, dsfield);
-       ipv6_change_dsfield(ipv6h, ~INET_ECN_MASK, dsfield);
+       ip6_flow_hdr(ipv6h, INET_ECN_encapsulate(0, dsfield), fl6->flowlabel);
        ipv6h->hop_limit = tunnel->parms.hop_limit;
        ipv6h->nexthdr = proto;
        ipv6h->saddr = fl6->saddr;
@@ -1240,7 +1238,7 @@ static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
        struct ipv6hdr *ipv6h = (struct ipv6hdr *)skb_push(skb, t->hlen);
        __be16 *p = (__be16 *)(ipv6h+1);
 
-       *(__be32 *)ipv6h = t->fl.u.ip6.flowlabel | htonl(0x60000000);
+       ip6_flow_hdr(ipv6h, 0, t->fl.u.ip6.flowlabel);
        ipv6h->hop_limit = t->parms.hop_limit;
        ipv6h->nexthdr = NEXTHDR_GRE;
        ipv6h->saddr = t->parms.laddr;

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 5552d13ae92f8554c04ec912b82317dfeef065a5..9250c696de9dafdc22b1824b1f59298bd7299377 100644 (file)
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -216,7 +216,7 @@ int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
        if (hlimit < 0)
                hlimit = ip6_dst_hoplimit(dst);
 
-       *(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | fl6->flowlabel;
+       ip6_flow_hdr(hdr, tclass, fl6->flowlabel);
 
        hdr->payload_len = htons(seg_len);
        hdr->nexthdr = proto;
@@ -267,7 +267,7 @@ int ip6_nd_hdr(struct sock *sk, struct sk_buff *skb, struct net_device *dev,
        skb_put(skb, sizeof(struct ipv6hdr));
        hdr = ipv6_hdr(skb);
 
-       *(__be32*)hdr = htonl(0x60000000);
+       ip6_flow_hdr(hdr, 0, 0);
 
        hdr->payload_len = htons(len);
        hdr->nexthdr = proto;
@@ -1548,9 +1548,7 @@ int ip6_push_pending_frames(struct sock *sk)
        skb_reset_network_header(skb);
        hdr = ipv6_hdr(skb);
 
-       *(__be32*)hdr = fl6->flowlabel |
-                    htonl(0x60000000 | ((int)np->cork.tclass << 20));
-
+       ip6_flow_hdr(hdr, np->cork.tclass, fl6->flowlabel);
        hdr->hop_limit = np->cork.hop_limit;
        hdr->nexthdr = proto;
        hdr->saddr = fl6->saddr;

diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index a14f28b280f57a040e3d499955419f6c949c5c93..fff83cbc197f1cc22149698d0b8f54fea0d107e8 100644 (file)
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -1030,9 +1030,7 @@ static int ip6_tnl_xmit2(struct sk_buff *skb,
        skb_push(skb, sizeof(struct ipv6hdr));
        skb_reset_network_header(skb);
        ipv6h = ipv6_hdr(skb);
-       *(__be32*)ipv6h = fl6->flowlabel | htonl(0x60000000);
-       dsfield = INET_ECN_encapsulate(0, dsfield);
-       ipv6_change_dsfield(ipv6h, ~INET_ECN_MASK, dsfield);
+       ip6_flow_hdr(ipv6h, INET_ECN_encapsulate(0, dsfield), fl6->flowlabel);
        ipv6h->hop_limit = t->parms.hop_limit;
        ipv6h->nexthdr = proto;
        ipv6h->saddr = fl6->saddr;

diff --git a/net/ipv6/netfilter/ip6t_REJECT.c b/net/ipv6/netfilter/ip6t_REJECT.c
index fd4fb34c51c7f5b9bd62294de2abb6da943ee494..8e75b6f3db91f3dc789c193f608d261edccc8f85 100644 (file)
--- a/net/ipv6/netfilter/ip6t_REJECT.c
+++ b/net/ipv6/netfilter/ip6t_REJECT.c
@@ -126,7 +126,7 @@ static void send_reset(struct net *net, struct sk_buff *oldskb)
        skb_put(nskb, sizeof(struct ipv6hdr));
        skb_reset_network_header(nskb);
        ip6h = ipv6_hdr(nskb);
-       *(__be32 *)ip6h =  htonl(0x60000000 | (tclass << 20));
+       ip6_flow_hdr(ip6h, tclass, 0);
        ip6h->hop_limit = ip6_dst_hoplimit(dst);
        ip6h->nexthdr = IPPROTO_TCP;
        ip6h->saddr = oip6h->daddr;