202 	u32 mtu;  in ip6_xmit()  local
260 	mtu = dst_mtu(dst);  in ip6_xmit()
261 	if ((skb->len <= mtu) || skb->ignore_df || skb_is_gso(skb)) {  in ip6_xmit()
284 	ipv6_local_error((struct sock *)sk, EMSGSIZE, fl6, mtu);  in ip6_xmit()
384 static bool ip6_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)  in ip6_pkt_too_big()  argument
386 	if (skb->len <= mtu)  in ip6_pkt_too_big()
390 	if (IP6CB(skb)->frag_max_size && IP6CB(skb)->frag_max_size > mtu)  in ip6_pkt_too_big()
396 	if (skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu))  in ip6_pkt_too_big()
409 	u32 mtu;  in ip6_forward()  local
523 	mtu = ip6_dst_mtu_forward(dst);  in ip6_forward()
524 	if (mtu < IPV6_MIN_MTU)  in ip6_forward()
525 		mtu = IPV6_MIN_MTU;  in ip6_forward()
527 	if (ip6_pkt_too_big(skb, mtu)) {  in ip6_forward()
530 		icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);  in ip6_forward()
589 	unsigned int mtu, hlen, left, len;  in ip6_fragment()  local
601 	mtu = ip6_skb_dst_mtu(skb);  in ip6_fragment()
606 	if (unlikely(!skb->ignore_df && skb->len > mtu))  in ip6_fragment()
610 		if (IP6CB(skb)->frag_max_size > mtu)  in ip6_fragment()
614 		mtu = IP6CB(skb)->frag_max_size;  in ip6_fragment()
615 		if (mtu < IPV6_MIN_MTU)  in ip6_fragment()
616 			mtu = IPV6_MIN_MTU;  in ip6_fragment()
619 	if (np && np->frag_size < mtu) {  in ip6_fragment()
621 			mtu = np->frag_size;  in ip6_fragment()
623 	if (mtu < hlen + sizeof(struct frag_hdr) + 8)  in ip6_fragment()
625 	mtu -= hlen + sizeof(struct frag_hdr);  in ip6_fragment()
639 		if (first_len - hlen > mtu ||  in ip6_fragment()
647 			if (frag->len > mtu ||  in ip6_fragment()
773 		if (len > mtu)  in ip6_fragment()
774 			len = mtu;  in ip6_fragment()
859 	icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);  in ip6_fragment()
1135 static void ip6_append_data_mtu(unsigned int *mtu,  in ip6_append_data_mtu()  argument
1145 			*mtu = orig_mtu - rt->dst.header_len;  in ip6_append_data_mtu()
1152 			*mtu = orig_mtu;  in ip6_append_data_mtu()
1154 		*maxfraglen = ((*mtu - fragheaderlen) & ~7)  in ip6_append_data_mtu()
1164 	unsigned int mtu;  in ip6_setup_cork()  local
1210 		mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ?  in ip6_setup_cork()
1211 		      READ_ONCE(rt->dst.dev->mtu) : dst_mtu(&rt->dst);  in ip6_setup_cork()
1213 		mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ?  in ip6_setup_cork()
1214 			READ_ONCE(rt->dst.dev->mtu) : dst_mtu(xfrm_dst_path(&rt->dst));  in ip6_setup_cork()
1215 	if (np->frag_size < mtu) {  in ip6_setup_cork()
1217 			mtu = np->frag_size;  in ip6_setup_cork()
1219 	if (mtu < IPV6_MIN_MTU)  in ip6_setup_cork()
1221 	cork->base.fragsize = mtu;  in ip6_setup_cork()
1247 	unsigned int maxfraglen, fragheaderlen, mtu, orig_mtu, pmtu;  in __ip6_append_data()  local
1269 	mtu = cork->gso_size ? IP6_MAX_MTU : cork->fragsize;  in __ip6_append_data()
1270 	orig_mtu = mtu;  in __ip6_append_data()
1280 	maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen -  in __ip6_append_data()
1292 	if (headersize + transhdrlen > mtu)  in __ip6_append_data()
1295 	if (cork->length + length > mtu - headersize && ipc6->dontfrag &&  in __ip6_append_data()
1298 		ipv6_local_rxpmtu(sk, fl6, mtu - headersize +  in __ip6_append_data()
1306 		maxnonfragsize = mtu;  in __ip6_append_data()
1310 		pmtu = max_t(int, mtu - headersize + sizeof(struct ipv6hdr), 0);  in __ip6_append_data()
1320 	    length <= mtu - headersize &&  in __ip6_append_data()
1347 		copy = (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len;  in __ip6_append_data()
1366 				ip6_append_data_mtu(&mtu, &maxfraglen,  in __ip6_append_data()
1378 …if (datalen > (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fraghe…  in __ip6_append_data()
1384 				alloclen = mtu;  in __ip6_append_data()