--- zzzz-none-000/linux-3.10.107/net/ipv4/ip_forward.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/net/ipv4/ip_forward.c	2021-02-04 17:41:59.000000000 +0000
@@ -39,92 +39,63 @@
 #include <net/route.h>
 #include <net/xfrm.h>
 
-static bool ip_may_fragment(const struct sk_buff *skb)
-{
-	return unlikely((ip_hdr(skb)->frag_off & htons(IP_DF)) == 0) ||
-		skb->local_df;
-}
+#ifdef CONFIG_AVM_PA
+#include <avm/pa/avm_pa.h>
+#endif
+
+int sysctl_ip_use_legacy_tos __read_mostly = 1;
+EXPORT_SYMBOL(sysctl_ip_use_legacy_tos);
 
 static bool ip_exceeds_mtu(const struct sk_buff *skb, unsigned int mtu)
 {
 	if (skb->len <= mtu)
 		return false;
 
-	if (skb_is_gso(skb) && skb_gso_network_seglen(skb) <= mtu)
+	if (unlikely((ip_hdr(skb)->frag_off & htons(IP_DF)) == 0))
 		return false;
 
-	return true;
-}
-
-static bool ip_gso_exceeds_dst_mtu(const struct sk_buff *skb)
-{
-	unsigned int mtu;
+	/* original fragment exceeds mtu and DF is set */
+	if (unlikely(IPCB(skb)->frag_max_size > mtu))
+		return true;
 
-	if (skb->local_df || !skb_is_gso(skb))
+	if (skb->ignore_df)
 		return false;
 
-	mtu = dst_mtu(skb_dst(skb));
+	if (skb_is_gso(skb) && skb_gso_network_seglen(skb) <= mtu)
+		return false;
 
-	/* if seglen > mtu, do software segmentation for IP fragmentation on
-	 * output.  DF bit cannot be set since ip_forward would have sent
-	 * icmp error.
-	 */
-	return skb_gso_network_seglen(skb) > mtu;
+	return true;
 }
 
-/* called if GSO skb needs to be fragmented on forward */
-static int ip_forward_finish_gso(struct sk_buff *skb)
-{
-	struct dst_entry *dst = skb_dst(skb);
-	netdev_features_t features;
-	struct sk_buff *segs;
-	int ret = 0;
-
-	features = netif_skb_dev_features(skb, dst->dev);
-	segs = skb_gso_segment(skb, features & ~NETIF_F_GSO_MASK);
-	if (IS_ERR(segs)) {
-		kfree_skb(skb);
-		return -ENOMEM;
-	}
-
-	consume_skb(skb);
 
-	do {
-		struct sk_buff *nskb = segs->next;
-		int err;
-
-		segs->next = NULL;
-		err = dst_output(segs);
-
-		if (err && ret == 0)
-			ret = err;
-		segs = nskb;
-	} while (segs);
-
-	return ret;
-}
-
-static int ip_forward_finish(struct sk_buff *skb)
+static int ip_forward_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
 {
 	struct ip_options *opt	= &(IPCB(skb)->opt);
 
-	IP_INC_STATS_BH(dev_net(skb_dst(skb)->dev), IPSTATS_MIB_OUTFORWDATAGRAMS);
-	IP_ADD_STATS_BH(dev_net(skb_dst(skb)->dev), IPSTATS_MIB_OUTOCTETS, skb->len);
+	IP_INC_STATS_BH(net, IPSTATS_MIB_OUTFORWDATAGRAMS);
+	IP_ADD_STATS_BH(net, IPSTATS_MIB_OUTOCTETS, skb->len);
 
 	if (unlikely(opt->optlen))
 		ip_forward_options(skb);
 
-	if (ip_gso_exceeds_dst_mtu(skb))
-		return ip_forward_finish_gso(skb);
-
-	return dst_output(skb);
+	skb_sender_cpu_clear(skb);
+#ifdef CONFIG_AVM_PA
+	avm_pa_mark_routed(skb);
+#endif
+	return dst_output(net, sk, skb);
 }
 
 int ip_forward(struct sk_buff *skb)
 {
+	u32 mtu;
 	struct iphdr *iph;	/* Our header */
 	struct rtable *rt;	/* Route we use */
 	struct ip_options *opt	= &(IPCB(skb)->opt);
+	struct net *net;
+
+	/* that should never happen */
+	if (skb->pkt_type != PACKET_HOST)
+		goto drop;
 
 	if (unlikely(skb->sk))
 		goto drop;
@@ -138,10 +109,8 @@
 	if (IPCB(skb)->opt.router_alert && ip_call_ra_chain(skb))
 		return NET_RX_SUCCESS;
 
-	if (skb->pkt_type != PACKET_HOST)
-		goto drop;
-
 	skb_forward_csum(skb);
+	net = dev_net(skb->dev);
 
 	/*
 	 *	According to the RFC, we must first decrease the TTL field. If
@@ -159,10 +128,12 @@
 	if (opt->is_strictroute && rt->rt_uses_gateway)
 		goto sr_failed;
 
-	if (!ip_may_fragment(skb) && ip_exceeds_mtu(skb, dst_mtu(&rt->dst))) {
-		IP_INC_STATS(dev_net(rt->dst.dev), IPSTATS_MIB_FRAGFAILS);
+	IPCB(skb)->flags |= IPSKB_FORWARDED;
+	mtu = ip_dst_mtu_maybe_forward(&rt->dst, true);
+	if (ip_exceeds_mtu(skb, mtu)) {
+		IP_INC_STATS(net, IPSTATS_MIB_FRAGFAILS);
 		icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
-			  htonl(dst_mtu(&rt->dst)));
+			  htonl(mtu));
 		goto drop;
 	}
 
@@ -182,10 +153,15 @@
 	    !skb_sec_path(skb))
 		ip_rt_send_redirect(skb);
 
-	skb->priority = rt_tos2priority(iph->tos);
+	/*
+	 * Set skb priority using legacy ToS method if required.
+	 */
+	if (sysctl_ip_use_legacy_tos != 0)
+		skb->priority = rt_tos2priority(iph->tos);
 
-	return NF_HOOK(NFPROTO_IPV4, NF_INET_FORWARD, skb, skb->dev,
-		       rt->dst.dev, ip_forward_finish);
+	return NF_HOOK(NFPROTO_IPV4, NF_INET_FORWARD,
+		       net, NULL, skb, skb->dev, rt->dst.dev,
+		       ip_forward_finish);
 
 sr_failed:
 	/*
@@ -196,7 +172,7 @@
 
 too_many_hops:
 	/* Tell the sender its packet died... */
-	IP_INC_STATS_BH(dev_net(skb_dst(skb)->dev), IPSTATS_MIB_INHDRERRORS);
+	IP_INC_STATS_BH(net, IPSTATS_MIB_INHDRERRORS);
 	icmp_send(skb, ICMP_TIME_EXCEEDED, ICMP_EXC_TTL, 0);
 drop:
 	kfree_skb(skb);