taglinefilesource code
IP_DF245net/ipv4/ip_forward.cif (skb->len+encap > dev2->mtu && (ntohs(iph->frag_off) & IP_DF)) {
IP_DF654net/ipv4/ip_fragment.cif (ntohs(iph->frag_off) & IP_DF)
IP_DF691net/ipv4/tcp.ciph->frag_off &= ~htons(IP_DF);
IP_DF1989net/ipv4/tcp.cskb->ip_hdr->frag_off |= htons(IP_DF);
IP_DF3351net/ipv4/tcp.ciph->frag_off &= ~htons(IP_DF);