From 3b760dcb0fd304873dfde9ff072a49f893c6f5c4 Mon Sep 17 00:00:00 2001 From: Liping Zhang Date: Sat, 3 Dec 2016 21:25:08 +0800 Subject: [PATCH] netfilter: rpfilter: bypass ipv4 lbcast packets with zeronet source Otherwise, DHCP Discover packets(0.0.0.0->255.255.255.255) may be dropped incorrectly. Signed-off-by: Liping Zhang Acked-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/ipv4/netfilter/ipt_rpfilter.c | 8 +++++--- net/ipv4/netfilter/nft_fib_ipv4.c | 13 +++++++------ 2 files changed, 12 insertions(+), 9 deletions(-) diff --git a/net/ipv4/netfilter/ipt_rpfilter.c b/net/ipv4/netfilter/ipt_rpfilter.c index 59b49945b481..f273098e48fd 100644 --- a/net/ipv4/netfilter/ipt_rpfilter.c +++ b/net/ipv4/netfilter/ipt_rpfilter.c @@ -83,10 +83,12 @@ static bool rpfilter_mt(const struct sk_buff *skb, struct xt_action_param *par) return true ^ invert; iph = ip_hdr(skb); - if (ipv4_is_multicast(iph->daddr)) { - if (ipv4_is_zeronet(iph->saddr)) - return ipv4_is_local_multicast(iph->daddr) ^ invert; + if (ipv4_is_zeronet(iph->saddr)) { + if (ipv4_is_lbcast(iph->daddr) || + ipv4_is_local_multicast(iph->daddr)) + return true ^ invert; } + flow.flowi4_iif = LOOPBACK_IFINDEX; flow.daddr = iph->saddr; flow.saddr = rpfilter_get_saddr(iph->daddr); diff --git a/net/ipv4/netfilter/nft_fib_ipv4.c b/net/ipv4/netfilter/nft_fib_ipv4.c index 258136364f5e..965b1a161369 100644 --- a/net/ipv4/netfilter/nft_fib_ipv4.c +++ b/net/ipv4/netfilter/nft_fib_ipv4.c @@ -101,12 +101,13 @@ void nft_fib4_eval(const struct nft_expr *expr, struct nft_regs *regs, } iph = ip_hdr(pkt->skb); - if (ipv4_is_multicast(iph->daddr) && - ipv4_is_zeronet(iph->saddr) && - ipv4_is_local_multicast(iph->daddr)) { - nft_fib_store_result(dest, priv->result, pkt, - get_ifindex(pkt->skb->dev)); - return; + if (ipv4_is_zeronet(iph->saddr)) { + if (ipv4_is_lbcast(iph->daddr) || + ipv4_is_local_multicast(iph->daddr)) { + nft_fib_store_result(dest, priv->result, pkt, + get_ifindex(pkt->skb->dev)); + return; + } } if (priv->flags & NFTA_FIB_F_MARK) -- 2.39.5