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authorLorenzo Colitti <lorenzo@google.com>2014-05-13 21:17:33 +0400
committerDavid S. Miller <davem@davemloft.net>2014-05-14 02:35:08 +0400
commite110861f86094cd78cc85593b873970092deb43a (patch)
tree535ecba8f65cefb68da0846ff54801bb32bf3c9e /net/ipv4/icmp.c
parent87e067cda6df60b55cea0239c2f3cee81e9f46df (diff)
downloadlinux-e110861f86094cd78cc85593b873970092deb43a.tar.xz
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 <lorenzo@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/icmp.c')
-rw-r--r--net/ipv4/icmp.c11
1 files changed, 9 insertions, 2 deletions
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;