From 5a4b081ae3266d5de1faea1cc51a7bafc23208aa 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 b92c2f282b (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 781b3cf86a2f5..a354db5b7662f 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 7167b08977df5..850525b34899f 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))) -- 2.39.5