IPv6/TCP checksum calcluated incorrectly

[alexirger]

Any IPv6/TCP packet crafted by sendip has incorrect TCP checksum on latest code.

Proposed patch:

diff --git a/tcp.c b/tcp.c
index fa9db26..56fcd46 100644
--- a/tcp.c
+++ b/tcp.c
@@ -74,7 +74,8 @@ static void tcp6csum(sendip_data *ipv6_hdr, sendip_data *tcp_hdr,
        memset(&phdr,0,sizeof(phdr));
        memcpy(&phdr.source,&ipv6->ip6_src,sizeof(struct in6_addr));
        memcpy(&phdr.destination,&ipv6->ip6_dst,sizeof(struct in6_addr));
-       phdr.ulp_length=IPPROTO_TCP;
+        phdr.nexthdr=IPPROTO_TCP;
+        phdr.ulp_length=htobe32(tcp_hdr->alloc_len+data->alloc_len);

        memcpy(tempbuf,&phdr,sizeof(phdr));

[ptpt52]

fixed in ptpt52/sendip@878ab01