tag	line	file	source code
IP_DF	246	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)
IP_DF	691	net/ipv4/tcp.c	iph->frag_off &= ~htons(IP_DF);
IP_DF	2009	net/ipv4/tcp.c	skb->ip_hdr->frag_off |= htons(IP_DF);
IP_DF	3373	net/ipv4/tcp.c	iph->frag_off &= ~htons(IP_DF);