@@ -547,6 +547,15 @@ 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
*/
@@ -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;
@@ -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;
@@ -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;
@@ -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;
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> --- include/net/ipv6.h | 9 +++++++++ net/ipv6/ip6_gre.c | 6 ++---- net/ipv6/ip6_output.c | 8 +++----- net/ipv6/ip6_tunnel.c | 4 +--- net/ipv6/netfilter/ip6t_REJECT.c | 2 +- 5 files changed, 16 insertions(+), 13 deletions(-)