[NETFILTER]: Fix DHCP + MASQUERADE problem 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 --- commit 5048a58f5d9643ca88593cda13433006599b77d3 tree fec8093ebdf5c8f44c87492fadcedbb7ad40f6ae parent 9af9e2ec732d00e62b458b46829bc696987d68af author Patrick McHardy Tue, 13 Sep 2005 09:32:06 +0200 committer Patrick McHardy Tue, 13 Sep 2005 09:32:06 +0200 net/ipv4/netfilter/ipt_MASQUERADE.c | 6 ++++++ 1 files changed, 6 insertions(+), 0 deletions(-) diff --git a/net/ipv4/netfilter/ipt_MASQUERADE.c b/net/ipv4/netfilter/ipt_MASQUERADE.c --- a/net/ipv4/netfilter/ipt_MASQUERADE.c +++ b/net/ipv4/netfilter/ipt_MASQUERADE.c @@ -90,6 +90,12 @@ 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);