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/ipv4/icmp.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'net/ipv4/icmp.c') diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c index fe52666dc43c..79c3d947a481 100644 --- a/net/ipv4/icmp.c +++ b/net/ipv4/icmp.c @@ -337,6 +337,7 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb) struct sock *sk; struct inet_sock *inet; __be32 daddr, saddr; + u32 mark = IP4_REPLY_MARK(net, skb->mark); if (ip_options_echo(&icmp_param->replyopts.opt.opt, skb)) return; @@ -349,6 +350,7 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb) icmp_param->data.icmph.checksum = 0; inet->tos = ip_hdr(skb)->tos; + sk->sk_mark = mark; daddr = ipc.addr = ip_hdr(skb)->saddr; saddr = fib_compute_spec_dst(skb); ipc.opt = NULL; @@ -364,6 +366,7 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb) memset(&fl4, 0, sizeof(fl4)); fl4.daddr = daddr; fl4.saddr = saddr; + fl4.flowi4_mark = mark; fl4.flowi4_tos = RT_TOS(ip_hdr(skb)->tos); fl4.flowi4_proto = IPPROTO_ICMP; security_skb_classify_flow(skb, flowi4_to_flowi(&fl4)); @@ -382,7 +385,7 @@ static struct rtable *icmp_route_lookup(struct net *net, struct flowi4 *fl4, struct sk_buff *skb_in, const struct iphdr *iph, - __be32 saddr, u8 tos, + __be32 saddr, u8 tos, u32 mark, int type, int code, struct icmp_bxm *param) { @@ -394,6 +397,7 @@ static struct rtable *icmp_route_lookup(struct net *net, fl4->daddr = (param->replyopts.opt.opt.srr ? param->replyopts.opt.opt.faddr : iph->saddr); fl4->saddr = saddr; + fl4->flowi4_mark = mark; fl4->flowi4_tos = RT_TOS(tos); fl4->flowi4_proto = IPPROTO_ICMP; fl4->fl4_icmp_type = type; @@ -491,6 +495,7 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info) struct flowi4 fl4; __be32 saddr; u8 tos; + u32 mark; struct net *net; struct sock *sk; @@ -592,6 +597,7 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info) tos = icmp_pointers[type].error ? ((iph->tos & IPTOS_TOS_MASK) | IPTOS_PREC_INTERNETCONTROL) : iph->tos; + mark = IP4_REPLY_MARK(net, skb_in->mark); if (ip_options_echo(&icmp_param->replyopts.opt.opt, skb_in)) goto out_unlock; @@ -608,13 +614,14 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info) icmp_param->skb = skb_in; icmp_param->offset = skb_network_offset(skb_in); inet_sk(sk)->tos = tos; + sk->sk_mark = mark; ipc.addr = iph->saddr; ipc.opt = &icmp_param->replyopts.opt; ipc.tx_flags = 0; ipc.ttl = 0; ipc.tos = -1; - rt = icmp_route_lookup(net, &fl4, skb_in, iph, saddr, tos, + rt = icmp_route_lookup(net, &fl4, skb_in, iph, saddr, tos, mark, type, code, icmp_param); if (IS_ERR(rt)) goto out_unlock; -- cgit v1.2.3