[ovs-dev] [PATCH 1/2] datapath: Set the correct bits for OFPAT_SET_NW_TOS action.

Ben Pfaff blp at nicira.com
Thu Feb 11 15:22:15 PST 2010


The DSCP bits are the high bits, not the low bits.

Reported-by: Jean Tourrilhes <jt at hpl.hp.com>
---
 datapath/actions.c |    9 +++++----
 lib/dpif-netdev.c  |    4 ++--
 lib/flow.c         |    2 +-
 lib/packets.h      |    6 +++++-
 4 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/datapath/actions.c b/datapath/actions.c
index 3eea532..0aefb8d 100644
--- a/datapath/actions.c
+++ b/datapath/actions.c
@@ -1,6 +1,6 @@
 /*
  * Distributed under the terms of the GNU GPL version 2.
- * Copyright (c) 2007, 2008, 2009 Nicira Networks.
+ * Copyright (c) 2007, 2008, 2009, 2010 Nicira Networks.
  *
  * Significant portions of this file may be copied from parts of the Linux
  * kernel, by Linus Torvalds and others.
@@ -15,6 +15,7 @@
 #include <linux/udp.h>
 #include <linux/in6.h>
 #include <linux/if_vlan.h>
+#include <net/inet_ecn.h>
 #include <net/ip.h>
 #include <net/checksum.h>
 #include "datapath.h"
@@ -265,10 +266,10 @@ static struct sk_buff *set_nw_tos(struct sk_buff *skb,
 		struct iphdr *nh = ip_hdr(skb);
 		u8 *f = &nh->tos;
 		u8 old = *f;
+		u8 new;
 
-		/* We only set the lower 6 bits. */
-		u8 new = (a->nw_tos & 0x3f) | (nh->tos & 0xc0);
-
+		/* Set the DSCP bits and preserve the ECN bits. */
+		new = (a->nw_tos & ~INET_ECN_MASK) | (nh->tos & INET_ECN_MASK);
 		update_csum(&nh->check, skb, htons((uint16_t)old),
 				htons((uint16_t)new), 0);
 		*f = new;
diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
index 54fff5e..d576c73 100644
--- a/lib/dpif-netdev.c
+++ b/lib/dpif-netdev.c
@@ -1180,8 +1180,8 @@ dp_netdev_set_nw_tos(struct ofpbuf *packet, flow_t *key,
         struct ip_header *nh = packet->l3;
         uint8_t *field = &nh->ip_tos;
 
-        /* We only set the lower 6 bits. */
-        uint8_t new = (a->nw_tos & 0x3f) | (nh->ip_tos & 0xc0);
+        /* Set the DSCP bits and preserve the ECN bits. */
+        uint8_t new = (a->nw_tos & IP_DSCP_MASK) | (nh->ip_tos & IP_ECN_MASK);
 
         nh->ip_csum = recalc_csum16(nh->ip_csum, htons((uint16_t)*field),
                 htons((uint16_t)a->nw_tos));
diff --git a/lib/flow.c b/lib/flow.c
index d22890e..7d368bb 100644
--- a/lib/flow.c
+++ b/lib/flow.c
@@ -151,7 +151,7 @@ flow_extract(struct ofpbuf *packet, uint16_t in_port, flow_t *flow)
             if (nh) {
                 flow->nw_src = nh->ip_src;
                 flow->nw_dst = nh->ip_dst;
-                flow->nw_tos = nh->ip_tos & 0xfc;
+                flow->nw_tos = nh->ip_tos & IP_DSCP_MASK;
                 flow->nw_proto = nh->ip_proto;
                 packet->l4 = b.data;
                 if (!IP_IS_FRAGMENT(nh->ip_frag_off)) {
diff --git a/lib/packets.h b/lib/packets.h
index 4595c12..6fab659 100644
--- a/lib/packets.h
+++ b/lib/packets.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2009 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010 Nicira Networks.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -213,6 +213,10 @@ BUILD_ASSERT_DECL(VLAN_ETH_HEADER_LEN == sizeof(struct vlan_eth_header));
 #define IP_IHL(ip_ihl_ver) ((ip_ihl_ver) & 15)
 #define IP_IHL_VER(ihl, ver) (((ver) << 4) | (ihl))
 
+/* TOS fields. */
+#define IP_ECN_MASK 0x03
+#define IP_DSCP_MASK 0xfc
+
 #define IP_TYPE_ICMP 1
 #define IP_TYPE_TCP 6
 #define IP_TYPE_UDP 17
-- 
1.6.6.1





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