42 static bool ip_exceeds_mtu(const struct sk_buff *skb, unsigned int mtu)  in ip_exceeds_mtu()  argument
44 	if (skb->len <= mtu)  in ip_exceeds_mtu()
47 	if (unlikely((ip_hdr(skb)->frag_off & htons(IP_DF)) == 0))  in ip_exceeds_mtu()
51 	if (unlikely(IPCB(skb)->frag_max_size > mtu))  in ip_exceeds_mtu()
54 	if (skb->ignore_df)  in ip_exceeds_mtu()
57 	if (skb_is_gso(skb) && skb_gso_network_seglen(skb) <= mtu)  in ip_exceeds_mtu()
64 static int ip_forward_finish(struct net *net, struct sock *sk, struct sk_buff *skb)  in ip_forward_finish()  argument
66 	struct ip_options *opt	= &(IPCB(skb)->opt);  in ip_forward_finish()
69 	IP_ADD_STATS_BH(net, IPSTATS_MIB_OUTOCTETS, skb->len);  in ip_forward_finish()
72 		ip_forward_options(skb);  in ip_forward_finish()
74 	skb_sender_cpu_clear(skb);  in ip_forward_finish()
75 	return dst_output(net, sk, skb);  in ip_forward_finish()
78 int ip_forward(struct sk_buff *skb)  in ip_forward()  argument
83 	struct ip_options *opt	= &(IPCB(skb)->opt);  in ip_forward()
87 	if (skb->pkt_type != PACKET_HOST)  in ip_forward()
90 	if (unlikely(skb->sk))  in ip_forward()
93 	if (skb_warn_if_lro(skb))  in ip_forward()
96 	if (!xfrm4_policy_check(NULL, XFRM_POLICY_FWD, skb))  in ip_forward()
99 	if (IPCB(skb)->opt.router_alert && ip_call_ra_chain(skb))  in ip_forward()
102 	skb_forward_csum(skb);  in ip_forward()
103 	net = dev_net(skb->dev);  in ip_forward()
110 	if (ip_hdr(skb)->ttl <= 1)  in ip_forward()
113 	if (!xfrm4_route_forward(skb))  in ip_forward()
116 	rt = skb_rtable(skb);  in ip_forward()
121 	IPCB(skb)->flags |= IPSKB_FORWARDED;  in ip_forward()
123 	if (ip_exceeds_mtu(skb, mtu)) {  in ip_forward()
125 		icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,  in ip_forward()
131 	if (skb_cow(skb, LL_RESERVED_SPACE(rt->dst.dev)+rt->dst.header_len))  in ip_forward()
133 	iph = ip_hdr(skb);  in ip_forward()
142 	if (IPCB(skb)->flags & IPSKB_DOREDIRECT && !opt->srr &&  in ip_forward()
143 	    !skb_sec_path(skb))  in ip_forward()
144 		ip_rt_send_redirect(skb);  in ip_forward()
146 	skb->priority = rt_tos2priority(iph->tos);  in ip_forward()
149 		       net, NULL, skb, skb->dev, rt->dst.dev,  in ip_forward()
156 	 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_SR_FAILED, 0);  in ip_forward()
162 	icmp_send(skb, ICMP_TIME_EXCEEDED, ICMP_EXC_TTL, 0);  in ip_forward()
164 	kfree_skb(skb);  in ip_forward()