ip_tunnel: Do not use inner ip-header-id for tunnel ip-header-id. (4221f405) · Commits · 戴 / test

Using inner-id for tunnel id is not safe in some rare cases. E.g. packets coming from multiple sources entering same tunnel can have same id. Therefore on tunnel packet receive we could have packets from two different stream but with same source and dst IP with same ip-id which could confuse ip packet reassembly. Following patch reverts optimization from commit (IP_GRE: Fix IP-Identification.) CC: Jarno Rajahalme <jrajahalme@nicira.com> CC: Ansis Atteka <aatteka@nicira.com> Signed-off-by:

Pravin B Shelar <pshelar@nicira.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

include/net/ip_tunnels.h

+0 −14

Original line number	Diff line number	Diff line
		@@ -145,20 +145,6 @@ static inline u8 ip_tunnel_ecn_encap(u8 tos, const struct iphdr *iph,
		return INET_ECN_encapsulate(tos, inner);
		}

		static inline void tunnel_ip_select_ident(struct sk_buff *skb,
		const struct iphdr *old_iph,
		struct dst_entry *dst)
		{
		struct iphdr *iph = ip_hdr(skb);

		/* Use inner packet iph-id if possible. */
		if (skb->protocol == htons(ETH_P_IP) && old_iph->id)
		iph->id = old_iph->id;
		else
		__ip_select_ident(iph, dst,
		(skb_shinfo(skb)->gso_segs ?: 1) - 1);
		}

		int iptunnel_pull_header(struct sk_buff *skb, int hdr_len, __be16 inner_proto);
		int iptunnel_xmit(struct net net, struct rtable rt,
		struct sk_buff *skb,

net/ipv4/ip_tunnel_core.c

+1 −3

Original line number	Diff line number	Diff line
		@@ -76,9 +76,7 @@ int iptunnel_xmit(struct net net, struct rtable rt,
		iph->daddr = dst;
		iph->saddr = src;
		iph->ttl = ttl;
		tunnel_ip_select_ident(skb,
		(const struct iphdr *)skb_inner_network_header(skb),
		&rt->dst);
		__ip_select_ident(iph, &rt->dst, (skb_shinfo(skb)->gso_segs ?: 1) - 1);

		err = ip_local_out(skb);
		if (unlikely(net_xmit_eval(err)))

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