From 4221f40513233fa8edeef7fc82e44163fde03b9b Mon Sep 17 00:00:00 2001 From: Pravin B Shelar Date: Tue, 13 Aug 2013 01:41:06 -0700 Subject: [PATCH] ip_tunnel: Do not use inner ip-header-id for tunnel ip-header-id. 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 490ab08127 (IP_GRE: Fix IP-Identification.) CC: Jarno Rajahalme CC: Ansis Atteka Signed-off-by: Pravin B Shelar Signed-off-by: David S. Miller --- include/net/ip_tunnels.h | 14 -------------- net/ipv4/ip_tunnel_core.c | 4 +--- 2 files changed, 1 insertion(+), 17 deletions(-) diff --git a/include/net/ip_tunnels.h b/include/net/ip_tunnels.h index 781b3cf..a354db5 100644 --- a/include/net/ip_tunnels.h +++ b/include/net/ip_tunnels.h @@ -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, diff --git a/net/ipv4/ip_tunnel_core.c b/net/ipv4/ip_tunnel_core.c index 7167b08..850525b 100644 --- a/net/ipv4/ip_tunnel_core.c +++ b/net/ipv4/ip_tunnel_core.c @@ -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))) -- 2.7.4