From: Ido Schimmel <idosch@nvidia.com>
Date: Thu, 29 Aug 2024 06:54:50 +0000 (+0300)
Subject: ipv4: icmp: Unmask upper DSCP bits in icmp_route_lookup()
X-Git-Tag: v6.12-rc1~232^2~133^2~9
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=4805646c42e51d2fbf142864d281473ad453ad5d;p=linux-2.6-block.git

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

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>
---

diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 1ed88883e1f2..d2463b6e390e 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>
 
@@ -497,7 +498,7 @@ 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;