From e110861f86094cd78cc85593b873970092deb43a Mon Sep 17 00:00:00 2001 From: Lorenzo Colitti Date: Tue, 13 May 2014 10:17:33 -0700 Subject: net: add a sysctl to reflect the fwmark on replies Kernel-originated IP packets that have no user socket associated with them (e.g., ICMP errors and echo replies, TCP RSTs, etc.) are emitted with a mark of zero. Add a sysctl to make them have the same mark as the packet they are replying to. This allows an administrator that wishes to do so to use mark-based routing, firewalling, etc. for these replies by marking the original packets inbound. Tested using user-mode linux: - ICMP/ICMPv6 echo replies and errors. - TCP RST packets (IPv4 and IPv6). Signed-off-by: Lorenzo Colitti Signed-off-by: David S. Miller --- net/ipv6/icmp.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'net/ipv6/icmp.c') diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c index 8d3952796d39..f6c84a6eb238 100644 --- a/net/ipv6/icmp.c +++ b/net/ipv6/icmp.c @@ -400,6 +400,7 @@ static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info) int len; int hlimit; int err = 0; + u32 mark = IP6_REPLY_MARK(net, skb->mark); if ((u8 *)hdr < skb->head || (skb_network_header(skb) + sizeof(*hdr)) > skb_tail_pointer(skb)) @@ -466,6 +467,7 @@ static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info) fl6.daddr = hdr->saddr; if (saddr) fl6.saddr = *saddr; + fl6.flowi6_mark = mark; fl6.flowi6_oif = iif; fl6.fl6_icmp_type = type; fl6.fl6_icmp_code = code; @@ -474,6 +476,7 @@ static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info) sk = icmpv6_xmit_lock(net); if (sk == NULL) return; + sk->sk_mark = mark; np = inet6_sk(sk); if (!icmpv6_xrlim_allow(sk, type, &fl6)) @@ -551,6 +554,7 @@ static void icmpv6_echo_reply(struct sk_buff *skb) int err = 0; int hlimit; u8 tclass; + u32 mark = IP6_REPLY_MARK(net, skb->mark); saddr = &ipv6_hdr(skb)->daddr; @@ -569,11 +573,13 @@ static void icmpv6_echo_reply(struct sk_buff *skb) fl6.saddr = *saddr; fl6.flowi6_oif = skb->dev->ifindex; fl6.fl6_icmp_type = ICMPV6_ECHO_REPLY; + fl6.flowi6_mark = mark; security_skb_classify_flow(skb, flowi6_to_flowi(&fl6)); sk = icmpv6_xmit_lock(net); if (sk == NULL) return; + sk->sk_mark = mark; np = inet6_sk(sk); if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) -- cgit v1.2.3-55-g7522