[PATCH 1/2] DSCP in IPv4 routing
TOS handling in ipv4 routing does not use all the bits in a DSCP
value. This change introduces a sysctl "route_tos_as_dscp" control
that, when enabled, widens masks to used the 6 DSCP bits in routing.
This commit adds the sysctl
Signed-off-by: Russell Strong <russ...@strong.id.au>
---
Documentation/networking/ip-sysctl.rst | 5 +++++
include/net/netns/ipv4.h | 2 ++
include/net/route.h | 16 ++++++++++++++++
include/uapi/linux/in_route.h | 3 +++
include/uapi/linux/ip.h | 2 ++
net/ipv4/sysctl_net_ipv4.c | 9 +++++++++
6 files changed, 37 insertions(+)
diff --git a/Documentation/networking/ip-sysctl.rst
b/Documentation/networking/ip-sysctl.rst
index dd2b12a32b73..e728c58dbc08 100644
--- a/Documentation/networking/ip-sysctl.rst
+++ b/Documentation/networking/ip-sysctl.rst
@@ -1596,6 +1596,11 @@ igmp_link_local_mcast_reports - BOOLEAN
Default TRUE
+route_tos_as_dscp - BOOLEAN
+ Interpret TOS as DSCP for routing purposes
+
+ Default 0
+
Alexey Kuznetsov.
kuz...@ms2.inr.ac.ru
diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
index 8e4fcac4df72..8c4230090149 100644
--- a/include/net/netns/ipv4.h
+++ b/include/net/netns/ipv4.h
@@ -197,6 +197,8 @@ struct netns_ipv4 {
int sysctl_igmp_llm_reports;
int sysctl_igmp_qrv;
+ int sysctl_route_tos_as_dscp;
+
struct ping_group_range ping_group_range;
atomic_t dev_addr_genid;
diff --git a/include/net/route.h b/include/net/route.h
index ff021cab657e..0cc8ce316940 100644
--- a/include/net/route.h
+++ b/include/net/route.h
@@ -38,6 +38,22 @@
/* IPv4 datagram length is stored into 16bit field (tot_len) */
#define IP_MAX_MTU 0xFFFFU
+static inline u8 iptos_rt_mask(const struct net *net)
+{
+ if (net->ipv4.sysctl_route_tos_as_dscp)
+ return IPTOS_DS_MASK;
+ else
+ return IPTOS_TOS_MASK & ~3;
+}
+
+static inline u8 rt_tos(const struct net *net, u8 tos)
+{
+ if (net->ipv4.sysctl_route_tos_as_dscp)
+ return RT_DS(tos);
+ else
+ return RT_TOS(tos);
+}
+
#define RTO_ONLINK 0x01
#define RT_CONN_FLAGS(sk) (RT_TOS(inet_sk(sk)->tos) | sock_flag(sk,
SOCK_LOCALROUTE))
diff --git a/include/uapi/linux/in_route.h b/include/uapi/linux/in_route.h
index 0cc2c23b47f8..61a95ed2a2e0 100644
--- a/include/uapi/linux/in_route.h
+++ b/include/uapi/linux/in_route.h
@@ -28,6 +28,9 @@
#define RTCF_NAT (RTCF_DNAT|RTCF_SNAT)
+/* sysctl route_tos_as_dscp = 0 */
#define RT_TOS(tos) ((tos)&IPTOS_TOS_MASK)
+/* sysctl route_tos_as_dscp = 1 */
+#define RT_DS(tos) ((tos)&IPTOS_DS_MASK)
#endif /* _LINUX_IN_ROUTE_H */
diff --git a/include/uapi/linux/ip.h b/include/uapi/linux/ip.h
index e42d13b55cf3..4a6b01e03cab 100644
--- a/include/uapi/linux/ip.h
+++ b/include/uapi/linux/ip.h
@@ -20,6 +20,8 @@
#include <linux/types.h>
#include <asm/byteorder.h>
+#define IPTOS_DS_MASK 0xFC
+#define IPTOS_DS(tos) ((tos)&IPTOS_DS_MASK)
#define IPTOS_TOS_MASK 0x1E
#define IPTOS_TOS(tos) ((tos)&IPTOS_TOS_MASK)
#define IPTOS_LOWDELAY 0x10
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 3e5f4f2e705e..61b1e2bd6bc5 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -790,6 +790,15 @@ static struct ctl_table ipv4_net_table[] = {
.extra2 = SYSCTL_ONE,
},
#endif
+ {
+ .procname = "route_tos_as_dscp",
+ .data = &init_net.ipv4.sysctl_route_tos_as_dscp,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = SYSCTL_ZERO,
+ .extra2 = SYSCTL_ONE,
+ },
{
.procname = "tcp_mtu_probing",
.data = &init_net.ipv4.sysctl_tcp_mtu_probing,
--
2.26.2
