-stable review patch. If anyone has any objections, please let us know. ------------------ In 2.6.13-rcX the MASQUERADE target was changed not to exclude local packets for better source address consistency. This breaks DHCP clients using UDP sockets when the DHCP requests are caught by a MASQUERADE rule because the MASQUERADE target drops packets when no address is configured on the outgoing interface. This patch makes it ignore packets with a source address of 0. Thanks to Rusty for this suggestion. Signed-off-by: Patrick McHardy Signed-off-by: Chris Wright --- net/ipv4/netfilter/ipt_MASQUERADE.c | 6 ++++++ 1 files changed, 6 insertions(+) Index: linux-2.6.13.y/net/ipv4/netfilter/ipt_MASQUERADE.c =================================================================== --- linux-2.6.13.y.orig/net/ipv4/netfilter/ipt_MASQUERADE.c +++ linux-2.6.13.y/net/ipv4/netfilter/ipt_MASQUERADE.c @@ -95,6 +95,12 @@ masquerade_target(struct sk_buff **pskb, IP_NF_ASSERT(ct && (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED || ctinfo == IP_CT_RELATED + IP_CT_IS_REPLY)); + /* Source address is 0.0.0.0 - locally generated packet that is + * probably not supposed to be masqueraded. + */ + if (ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip == 0) + return NF_ACCEPT; + mr = targinfo; rt = (struct rtable *)(*pskb)->dst; newsrc = inet_select_addr(out, rt->rt_gateway, RT_SCOPE_UNIVERSE); --