head_data_len    3813 net/ipv4/tcp.c 	const unsigned int head_data_len = skb_headlen(skb) > header_len ?
head_data_len    3820 net/ipv4/tcp.c 	sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len);
head_data_len    3821 net/ipv4/tcp.c 	ahash_request_set_crypt(req, &sg, NULL, head_data_len);