taglinefilesource code
send_tail671net/inet/af_inet.csk->send_tail = NULL;
send_tail1902net/inet/ip.csk->send_tail = skb;
send_tail1907net/inet/ip.csk->send_tail->link3 = skb;
send_tail1908net/inet/ip.csk->send_tail = skb;
send_tail100net/inet/sock.hstruct sk_buff    * volatile send_tail;
send_tail2736net/inet/tcp.cnewsk->send_tail = NULL;
send_tail3205net/inet/tcp.csk->send_tail = NULL;
send_tail3242net/inet/tcp.csk->send_tail = skb;
send_tail3246net/inet/tcp.csk->send_tail->link3 = skb;
send_tail3247net/inet/tcp.csk->send_tail = skb;
send_tail3259net/inet/tcp.cif (sk->send_tail == NULL || sk->send_head == NULL) 
send_tail3262net/inet/tcp.csk->send_tail = NULL;
send_tail3453net/inet/tcp.csk->send_tail = NULL;