tag	line	file	source code
IP_DF	251	net/ipv4/ip_forward.c	if (skb->len+encap > dev2->mtu && (ntohs(iph->frag_off) & IP_DF)) {
IP_DF	654	net/ipv4/ip_fragment.c	if (ntohs(iph->frag_off) & IP_DF)