ipv4: icmp: Unmask upper DSCP bits in icmp_route_lookup()

[ Upstream commit 4805646c42e51d2fbf142864d281473ad453ad5d ]

The function is called to resolve a route for an ICMP message that is
sent in response to a situation. Based on the type of the generated ICMP
message, the function is either passed the DS field of the packet that
generated the ICMP message or a DS field that is derived from it.

Unmask the upper DSCP bits before resolving and output route via
ip_route_output_key_hash() so that in the future the lookup could be
performed according to the full DSCP value.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 27843ce6ba3d ("ipvlan: ensure network headers are in skb linear part")
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 3807a269e0755bf5a2ce1d52a26146d66ffad26c..a154339845dd4451505d1cb3bf0c151ee9166deb 100644 (file)
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -93,6 +93,7 @@
 #include <net/ip_fib.h>
 #include <net/l3mdev.h>
 #include <net/addrconf.h>
+#include <net/inet_dscp.h>
 #define CREATE_TRACE_POINTS
 #include <trace/events/icmp.h>
 
@@ -502,7 +503,7 @@ static struct rtable *icmp_route_lookup(struct net *net,
        fl4->saddr = saddr;
        fl4->flowi4_mark = mark;
        fl4->flowi4_uid = sock_net_uid(net, NULL);
-       fl4->flowi4_tos = RT_TOS(tos);
+       fl4->flowi4_tos = tos & INET_DSCP_MASK;
        fl4->flowi4_proto = IPPROTO_ICMP;
        fl4->fl4_icmp_type = type;
        fl4->fl4_icmp_code = code;