[PATCH net-next v2 03/12] ipv4: icmp: Unmask upper DSCP bits in icmp_route_lookup()

[Ido Schimmel <idosch@nvidia.com>]

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>
---
 net/ipv4/icmp.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index b8f56d03fcbb..441057f2c903 100644
--- 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>
 
@@ -496,7 +497,7 @@ 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;
-- 
2.46.0