From 7b215ffc3885a38182d3d49ceb41d0a81c3e041a Mon Sep 17 00:00:00 2001 From: Hannes Eder Date: Fri, 23 Jul 2010 12:46:32 +0200 Subject: [PATCH] IPVS: make friends with nf_conntrack Update the nf_conntrack tuple in reply direction, as we will see traffic from the real server (RIP) to the client (CIP). Once this is done we can use netfilters SNAT in POSTROUTING, especially with xt_ipvs, to do source NAT, e.g.: % iptables -t nat -A POSTROUTING -m ipvs --vaddr 192.168.100.30/32 --vport 80 \ -j SNAT --to-source 192.168.10.10 [ minor fixes by Simon Horman ] Signed-off-by: Hannes Eder Signed-off-by: Simon Horman Signed-off-by: Patrick McHardy --- net/netfilter/ipvs/Kconfig | 2 +- net/netfilter/ipvs/ip_vs_core.c | 36 --------------------------------- net/netfilter/ipvs/ip_vs_xmit.c | 29 ++++++++++++++++++++++++++ 3 files changed, 30 insertions(+), 37 deletions(-) diff --git a/net/netfilter/ipvs/Kconfig b/net/netfilter/ipvs/Kconfig index d80b41abec09..366244492ac7 100644 --- a/net/netfilter/ipvs/Kconfig +++ b/net/netfilter/ipvs/Kconfig @@ -3,7 +3,7 @@ # menuconfig IP_VS tristate "IP virtual server support" - depends on NET && INET && NETFILTER + depends on NET && INET && NETFILTER && NF_CONNTRACK ---help--- IP Virtual Server support will let you build a high-performance virtual server based on cluster of two or more real servers. This diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c index 50907d8472a3..58f82dfc950a 100644 --- a/net/netfilter/ipvs/ip_vs_core.c +++ b/net/netfilter/ipvs/ip_vs_core.c @@ -536,26 +536,6 @@ int ip_vs_leave(struct ip_vs_service *svc, struct sk_buff *skb, return NF_DROP; } - -/* - * It is hooked before NF_IP_PRI_NAT_SRC at the NF_INET_POST_ROUTING - * chain, and is used for VS/NAT. - * It detects packets for VS/NAT connections and sends the packets - * immediately. This can avoid that iptable_nat mangles the packets - * for VS/NAT. - */ -static unsigned int ip_vs_post_routing(unsigned int hooknum, - struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - int (*okfn)(struct sk_buff *)) -{ - if (!skb->ipvs_property) - return NF_ACCEPT; - /* The packet was sent from IPVS, exit this chain */ - return NF_STOP; -} - __sum16 ip_vs_checksum_complete(struct sk_buff *skb, int offset) { return csum_fold(skb_checksum(skb, offset, skb->len - offset, 0)); @@ -1499,14 +1479,6 @@ static struct nf_hook_ops ip_vs_ops[] __read_mostly = { .hooknum = NF_INET_FORWARD, .priority = 99, }, - /* Before the netfilter connection tracking, exit from POST_ROUTING */ - { - .hook = ip_vs_post_routing, - .owner = THIS_MODULE, - .pf = PF_INET, - .hooknum = NF_INET_POST_ROUTING, - .priority = NF_IP_PRI_NAT_SRC-1, - }, #ifdef CONFIG_IP_VS_IPV6 /* After packet filtering, forward packet through VS/DR, VS/TUN, * or VS/NAT(change destination), so that filtering rules can be @@ -1535,14 +1507,6 @@ static struct nf_hook_ops ip_vs_ops[] __read_mostly = { .hooknum = NF_INET_FORWARD, .priority = 99, }, - /* Before the netfilter connection tracking, exit from POST_ROUTING */ - { - .hook = ip_vs_post_routing, - .owner = THIS_MODULE, - .pf = PF_INET6, - .hooknum = NF_INET_POST_ROUTING, - .priority = NF_IP6_PRI_NAT_SRC-1, - }, #endif }; diff --git a/net/netfilter/ipvs/ip_vs_xmit.c b/net/netfilter/ipvs/ip_vs_xmit.c index 02b078e11cf3..21e1a5e9b9d3 100644 --- a/net/netfilter/ipvs/ip_vs_xmit.c +++ b/net/netfilter/ipvs/ip_vs_xmit.c @@ -28,6 +28,7 @@ #include #include #include +#include #include #include @@ -348,6 +349,30 @@ ip_vs_bypass_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp, } #endif +static void +ip_vs_update_conntrack(struct sk_buff *skb, struct ip_vs_conn *cp) +{ + struct nf_conn *ct = (struct nf_conn *)skb->nfct; + struct nf_conntrack_tuple new_tuple; + + if (ct == NULL || nf_ct_is_untracked(ct) || nf_ct_is_confirmed(ct)) + return; + + /* + * The connection is not yet in the hashtable, so we update it. + * CIP->VIP will remain the same, so leave the tuple in + * IP_CT_DIR_ORIGINAL untouched. When the reply comes back from the + * real-server we will see RIP->DIP. + */ + new_tuple = ct->tuplehash[IP_CT_DIR_REPLY].tuple; + new_tuple.src.u3 = cp->daddr; + /* + * This will also take care of UDP and other protocols. + */ + new_tuple.src.u.tcp.port = cp->dport; + nf_conntrack_alter_reply(ct, &new_tuple); +} + /* * NAT transmitter (only for outside-to-inside nat forwarding) * Not used for related ICMP @@ -403,6 +428,8 @@ ip_vs_nat_xmit(struct sk_buff *skb, struct ip_vs_conn *cp, IP_VS_DBG_PKT(10, pp, skb, 0, "After DNAT"); + ip_vs_update_conntrack(skb, cp); + /* FIXME: when application helper enlarges the packet and the length is larger than the MTU of outgoing device, there will be still MTU problem. */ @@ -479,6 +506,8 @@ ip_vs_nat_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp, IP_VS_DBG_PKT(10, pp, skb, 0, "After DNAT"); + ip_vs_update_conntrack(skb, cp); + /* FIXME: when application helper enlarges the packet and the length is larger than the MTU of outgoing device, there will be still MTU problem. */ -- GitLab