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 ++++++ net/ipv6/sysctl_net_ipv6.c | 7 +++++++ net/ipv6/tcp_ipv6.c | 1 + 3 files changed, 14 insertions(+) (limited to 'net/ipv6') 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)) diff --git a/net/ipv6/sysctl_net_ipv6.c b/net/ipv6/sysctl_net_ipv6.c index 7f405a168822..058f3eca2e53 100644 --- a/net/ipv6/sysctl_net_ipv6.c +++ b/net/ipv6/sysctl_net_ipv6.c @@ -38,6 +38,13 @@ static struct ctl_table ipv6_table_template[] = { .mode = 0644, .proc_handler = proc_dointvec }, + { + .procname = "fwmark_reflect", + .data = &init_net.ipv6.sysctl.fwmark_reflect, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec + }, { } }; diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 3a267bf14f2f..c54976a44425 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -812,6 +812,7 @@ static void tcp_v6_send_response(struct sk_buff *skb, u32 seq, u32 ack, u32 win, fl6.flowi6_oif = inet6_iif(skb); else fl6.flowi6_oif = oif; + fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark); fl6.fl6_dport = t1->dest; fl6.fl6_sport = t1->source; security_skb_classify_flow(skb, flowi6_to_flowi(&fl6)); -- cgit v1.2.1