ndisc: Defer building IPv6 header.
Build ICMPv6 message first and make buffer management easier;
we can use skb->len when filling checksum in ICMPv6 header,
and then build IP header with length field.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 200b2b2..09171fd 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -387,7 +387,7 @@
skb->protocol = htons(ETH_P_IPV6);
skb->dev = dev;
- skb_reserve(skb, hlen);
+ skb_reserve(skb, hlen + sizeof(struct ipv6hdr));
return skb;
}
@@ -399,8 +399,8 @@
{
struct ipv6hdr *hdr;
+ skb_push(skb, sizeof(*hdr));
skb_reset_network_header(skb);
- skb_put(skb, sizeof(struct ipv6hdr));
hdr = ipv6_hdr(skb);
ip6_flow_hdr(hdr, 0, 0);
@@ -438,8 +438,6 @@
if (!skb)
return NULL;
- ip6_nd_hdr(skb, saddr, daddr, inet6_sk(sk)->hop_limit, len);
-
skb->transport_header = skb->tail;
skb_put(skb, len);
@@ -455,10 +453,12 @@
if (llinfo)
ndisc_fill_addr_option(opt, llinfo, dev->dev_addr, dev);
- hdr->icmp6_cksum = csum_ipv6_magic(saddr, daddr, len,
+ hdr->icmp6_cksum = csum_ipv6_magic(saddr, daddr, skb->len,
IPPROTO_ICMPV6,
csum_partial(hdr,
- len, 0));
+ skb->len, 0));
+
+ ip6_nd_hdr(skb, saddr, daddr, inet6_sk(sk)->hop_limit, skb->len);
return skb;
}
@@ -1479,9 +1479,6 @@
if (!buff)
goto release;
- ip6_nd_hdr(buff, &saddr_buf, &ipv6_hdr(skb)->saddr,
- inet6_sk(sk)->hop_limit, len);
-
skb_set_transport_header(buff, skb_tail_pointer(buff) - buff->data);
skb_put(buff, len);
msg = (struct rd_msg *)icmp6_hdr(buff);
@@ -1513,8 +1510,11 @@
opt = ndisc_fill_redirect_hdr_option(opt, skb, rd_len);
msg->icmph.icmp6_cksum = csum_ipv6_magic(&saddr_buf, &ipv6_hdr(skb)->saddr,
- len, IPPROTO_ICMPV6,
- csum_partial(msg, len, 0));
+ buff->len, IPPROTO_ICMPV6,
+ csum_partial(msg, buff->len, 0));
+
+ ip6_nd_hdr(buff, &saddr_buf, &ipv6_hdr(skb)->saddr,
+ inet6_sk(sk)->hop_limit, buff->len);
skb_dst_set(buff, dst);
rcu_read_lock();