taglinefilesource code
send_tail609net/inet/af_inet.csk->send_tail = NULL;
send_tail1741net/inet/ip.csk->send_tail = skb;
send_tail1746net/inet/ip.csk->send_tail->link3 = skb;
send_tail1747net/inet/ip.csk->send_tail = skb;
send_tail93net/inet/sock.hstruct sk_buff    * volatile send_tail;
send_tail1954net/inet/tcp.cnewsk->send_tail = NULL;
send_tail2439net/inet/tcp.csk->send_tail = skb;
send_tail2452net/inet/tcp.csk->send_tail = skb;
send_tail2539net/inet/tcp.csk->send_tail = NULL;
send_tail2571net/inet/tcp.csk->send_tail = skb;
send_tail2575net/inet/tcp.csk->send_tail->link3 = skb;
send_tail2576net/inet/tcp.csk->send_tail = skb;
send_tail2584net/inet/tcp.cif (sk->send_tail == NULL || sk->send_head == NULL) 
send_tail2587net/inet/tcp.csk->send_tail = NULL;
send_tail2758net/inet/tcp.csk->send_tail = NULL;