From e5a4bc2e0b01b1a484091379a1a7f8ce098fb429 Mon Sep 17 00:00:00 2001 From: Julian Anastasov Date: Thu, 18 Dec 2014 22:41:23 +0200 Subject: ipvs: rerouting to local clients is not needed anymore commit 579eb62ac35845686a7c4286c0a820b4eb1f96aa upstream. commit f5a41847acc5 ("ipvs: move ip_route_me_harder for ICMP") from 2.6.37 introduced ip_route_me_harder() call for responses to local clients, so that we can provide valid rt_src after SNAT. It was used by TCP to provide valid daddr for ip_send_reply(). After commit 0a5ebb8000c5 ("ipv4: Pass explicit daddr arg to ip_send_reply()." from 3.0 this rerouting is not needed anymore and should be avoided, especially in LOCAL_IN. Fixes 3.12.33 crash in xfrm reported by Florian Wiessner: "3.12.33 - BUG xfrm_selector_match+0x25/0x2f6" Reported-by: Smart Weblications GmbH - Florian Wiessner Tested-by: Smart Weblications GmbH - Florian Wiessner Signed-off-by: Julian Anastasov Signed-off-by: Simon Horman Signed-off-by: Ben Hutchings Cc: Pablo Neira Ayuso --- net/netfilter/ipvs/ip_vs_core.c | 32 +++++++++++++++++++++----------- 1 file changed, 21 insertions(+), 11 deletions(-) (limited to 'net') diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c index 6dc7d7d..d864aaf 100644 --- a/net/netfilter/ipvs/ip_vs_core.c +++ b/net/netfilter/ipvs/ip_vs_core.c @@ -662,16 +662,24 @@ static inline int ip_vs_gather_frags_v6(struct sk_buff *skb, u_int32_t user) } #endif -static int ip_vs_route_me_harder(int af, struct sk_buff *skb) +static int ip_vs_route_me_harder(int af, struct sk_buff *skb, + unsigned int hooknum) { + if (!sysctl_snat_reroute(skb)) + return 0; + /* Reroute replies only to remote clients (FORWARD and LOCAL_OUT) */ + if (NF_INET_LOCAL_IN == hooknum) + return 0; #ifdef CONFIG_IP_VS_IPV6 if (af == AF_INET6) { - if (sysctl_snat_reroute(skb) && ip6_route_me_harder(skb) != 0) + struct dst_entry *dst = skb_dst(skb); + + if (dst->dev && !(dst->dev->flags & IFF_LOOPBACK) && + ip6_route_me_harder(skb) != 0) return 1; } else #endif - if ((sysctl_snat_reroute(skb) || - skb_rtable(skb)->rt_flags & RTCF_LOCAL) && + if (!(skb_rtable(skb)->rt_flags & RTCF_LOCAL) && ip_route_me_harder(skb, RTN_LOCAL) != 0) return 1; @@ -782,7 +790,8 @@ static int handle_response_icmp(int af, struct sk_buff *skb, union nf_inet_addr *snet, __u8 protocol, struct ip_vs_conn *cp, struct ip_vs_protocol *pp, - unsigned int offset, unsigned int ihl) + unsigned int offset, unsigned int ihl, + unsigned int hooknum) { unsigned int verdict = NF_DROP; @@ -812,7 +821,7 @@ static int handle_response_icmp(int af, struct sk_buff *skb, #endif ip_vs_nat_icmp(skb, pp, cp, 1); - if (ip_vs_route_me_harder(af, skb)) + if (ip_vs_route_me_harder(af, skb, hooknum)) goto out; /* do the statistics and put it back */ @@ -908,7 +917,7 @@ static int ip_vs_out_icmp(struct sk_buff *skb, int *related, snet.ip = iph->saddr; return handle_response_icmp(AF_INET, skb, &snet, cih->protocol, cp, - pp, offset, ihl); + pp, offset, ihl, hooknum); } #ifdef CONFIG_IP_VS_IPV6 @@ -985,7 +994,8 @@ static int ip_vs_out_icmp_v6(struct sk_buff *skb, int *related, ipv6_addr_copy(&snet.in6, &iph->saddr); return handle_response_icmp(AF_INET6, skb, &snet, cih->nexthdr, cp, - pp, offset, sizeof(struct ipv6hdr)); + pp, offset, sizeof(struct ipv6hdr), + hooknum); } #endif @@ -1018,7 +1028,7 @@ static inline int is_tcp_reset(const struct sk_buff *skb, int nh_len) */ static unsigned int handle_response(int af, struct sk_buff *skb, struct ip_vs_proto_data *pd, - struct ip_vs_conn *cp, int ihl) + struct ip_vs_conn *cp, int ihl, unsigned int hooknum) { struct ip_vs_protocol *pp = pd->pp; @@ -1056,7 +1066,7 @@ handle_response(int af, struct sk_buff *skb, struct ip_vs_proto_data *pd, * if it came from this machine itself. So re-compute * the routing information. */ - if (ip_vs_route_me_harder(af, skb)) + if (ip_vs_route_me_harder(af, skb, hooknum)) goto drop; IP_VS_DBG_PKT(10, af, pp, skb, 0, "After SNAT"); @@ -1169,7 +1179,7 @@ ip_vs_out(unsigned int hooknum, struct sk_buff *skb, int af) cp = pp->conn_out_get(af, skb, &iph, iph.len, 0); if (likely(cp)) - return handle_response(af, skb, pd, cp, iph.len); + return handle_response(af, skb, pd, cp, iph.len, hooknum); if (sysctl_nat_icmp_send(net) && (pp->protocol == IPPROTO_TCP || pp->protocol == IPPROTO_UDP || -- cgit v1.1