207 	u32 mtu;  in ip6_xmit()  local
264 	mtu = dst_mtu(dst);  in ip6_xmit()
265 	if ((skb->len <= mtu) || skb->ignore_df || skb_is_gso(skb)) {  in ip6_xmit()
288 	ipv6_local_error((struct sock *)sk, EMSGSIZE, fl6, mtu);  in ip6_xmit()
402 static bool ip6_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)  in ip6_pkt_too_big()  argument
404 	if (skb->len <= mtu)  in ip6_pkt_too_big()
408 	if (IP6CB(skb)->frag_max_size && IP6CB(skb)->frag_max_size > mtu)  in ip6_pkt_too_big()
414 	if (skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu))  in ip6_pkt_too_big()
427 	u32 mtu;  in ip6_forward()  local
541 	mtu = ip6_dst_mtu_forward(dst);  in ip6_forward()
542 	if (mtu < IPV6_MIN_MTU)  in ip6_forward()
543 		mtu = IPV6_MIN_MTU;  in ip6_forward()
545 	if (ip6_pkt_too_big(skb, mtu)) {  in ip6_forward()
548 		icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);  in ip6_forward()
665 void ip6_frag_init(struct sk_buff *skb, unsigned int hlen, unsigned int mtu,  in ip6_frag_init()  argument
674 	state->mtu = mtu;  in ip6_frag_init()
694 	/* IF: it doesn't fit, use 'mtu' - the data space left */  in ip6_frag_next()
695 	if (len > state->mtu)  in ip6_frag_next()
696 		len = state->mtu;  in ip6_frag_next()
770 	unsigned int mtu, hlen, nexthdr_offset;  in ip6_fragment()  local
783 	mtu = ip6_skb_dst_mtu(skb);  in ip6_fragment()
785 	/* We must not fragment if the socket is set to force MTU discovery  in ip6_fragment()
788 	if (unlikely(!skb->ignore_df && skb->len > mtu))  in ip6_fragment()
792 		if (IP6CB(skb)->frag_max_size > mtu)  in ip6_fragment()
796 		mtu = IP6CB(skb)->frag_max_size;  in ip6_fragment()
797 		if (mtu < IPV6_MIN_MTU)  in ip6_fragment()
798 			mtu = IPV6_MIN_MTU;  in ip6_fragment()
801 	if (np && np->frag_size < mtu) {  in ip6_fragment()
803 			mtu = np->frag_size;  in ip6_fragment()
805 	if (mtu < hlen + sizeof(struct frag_hdr) + 8)  in ip6_fragment()
807 	mtu -= hlen + sizeof(struct frag_hdr);  in ip6_fragment()
823 		if (first_len - hlen > mtu ||  in ip6_fragment()
831 			if (frag->len > mtu ||  in ip6_fragment()
900 	ip6_frag_init(skb, hlen, mtu, rt->dst.dev->needed_tailroom,  in ip6_fragment()
935 	icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);  in ip6_fragment()
1211 static void ip6_append_data_mtu(unsigned int *mtu,  in ip6_append_data_mtu()  argument
1221 			*mtu = orig_mtu - rt->dst.header_len;  in ip6_append_data_mtu()
1228 			*mtu = orig_mtu;  in ip6_append_data_mtu()
1230 		*maxfraglen = ((*mtu - fragheaderlen) & ~7)  in ip6_append_data_mtu()
1240 	unsigned int mtu;  in ip6_setup_cork()  local
1286 		mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ?  in ip6_setup_cork()
1287 		      READ_ONCE(rt->dst.dev->mtu) : dst_mtu(&rt->dst);  in ip6_setup_cork()
1289 		mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ?  in ip6_setup_cork()
1290 			READ_ONCE(rt->dst.dev->mtu) : dst_mtu(xfrm_dst_path(&rt->dst));  in ip6_setup_cork()
1291 	if (np->frag_size < mtu) {  in ip6_setup_cork()
1293 			mtu = np->frag_size;  in ip6_setup_cork()
1295 	if (mtu < IPV6_MIN_MTU)  in ip6_setup_cork()
1297 	cork->base.fragsize = mtu;  in ip6_setup_cork()
1324 	unsigned int maxfraglen, fragheaderlen, mtu, orig_mtu, pmtu;  in __ip6_append_data()  local
1347 	mtu = cork->gso_size ? IP6_MAX_MTU : cork->fragsize;  in __ip6_append_data()
1348 	orig_mtu = mtu;  in __ip6_append_data()
1358 	maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen -  in __ip6_append_data()
1370 	if (headersize + transhdrlen > mtu)  in __ip6_append_data()
1373 	if (cork->length + length > mtu - headersize && ipc6->dontfrag &&  in __ip6_append_data()
1376 		ipv6_local_rxpmtu(sk, fl6, mtu - headersize +  in __ip6_append_data()
1384 		maxnonfragsize = mtu;  in __ip6_append_data()
1388 		pmtu = max_t(int, mtu - headersize + sizeof(struct ipv6hdr), 0);  in __ip6_append_data()
1398 	    length <= mtu - headersize &&  in __ip6_append_data()
1419 	 * Use MTU if total length of the message fits into the MTU.  in __ip6_append_data()
1439 		copy = (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len;  in __ip6_append_data()
1456 			/* update mtu and maxfraglen if necessary */  in __ip6_append_data()
1458 				ip6_append_data_mtu(&mtu, &maxfraglen,  in __ip6_append_data()
1465 			 * If remaining data exceeds the mtu,  in __ip6_append_data()
1470 …if (datalen > (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fraghe…  in __ip6_append_data()
1477 				alloclen = mtu;  in __ip6_append_data()
1501 			 * (without MSG_MORE) fits into the MTU.  in __ip6_append_data()