diff mbox

ip6_tunnel, ip6_gre: fix setting of DSCP on encapsulated packets

Message ID CANX4UBcureLm+7wkC1C6=ZvV4JNTKzSCvzv-hV=w77O_WF4ntA@mail.gmail.com
State Changes Requested, archived
Delegated to: David Miller
Headers show

Commit Message

Peter Dawson May 18, 2017, 2:49 a.m. UTC 
>> This fix addresses two problems in the way the DSCP field is
>> formulated on the  encapsulating header of IPv6 tunnels.
>> This fix addresses Bug 195661.
>> https://bugzilla.kernel.org/show_bug.cgi?id=195661
>>
>> 1) The IPv6 tunneling code was manipulating the DSCP field of the
>> encapsulating  packet using the 32b flowlabel. Since the flowlabel is
>> only the lower 20b it  was incorrect to assume that the upper 12b
>> containing the DSCP and ECN fields  would remain intact when
>> formulating the encapsulating header. This fix  handles the 'inherit'
>> and 'fixed-value' DSCP cases explicitly using the extant  dsfield u8 variable.
>>
>> 2) The use of INET_ECN_encapsulate(0, dsfield) in ip6_tnl_xmit was
>> incorrect  and resulted in the DSCP value always being set to 0.
>> ---
>>  net/ipv6/ip6_gre.c    | 18 ++++++++++--------
>>  net/ipv6/ip6_tunnel.c | 28 +++++++++++++++++-----------
>>  2 files changed, 27 insertions(+), 19 deletions(-)
>
> This patch looks correct, but has trivial style issues like using spaces instead of tabs and other junk.  Please run checkpatch.pl, look at the results and resubmit.

Thanks.  I've run checkpatch.pl over this updated file with no errors.
Regards
Peter
diff mbox

Patch

From f12adb265f683d53ae071725e657dab17d26ed8d Mon Sep 17 00:00:00 2001
From: Peter Dawson <peter.a.dawson@boeing.com>
Date: Thu, 18 May 2017 11:52:22 +1000
Subject: [PATCH] ip6_tunnel, ip6_gre: fix setting of DSCP on encapsulated
 packets

This fix addresses two problems in the way the DSCP field is formulated
 on the encapsulating header of IPv6 tunnels.
This fix addresses Bug 195661.

1) The IPv6 tunneling code was manipulating the DSCP field of the
 encapsulating packet using the 32b flowlabel. Since the flowlabel is
 only the lower 20b it was incorrect to assume that the upper 12b
 containing the DSCP and ECN fields would remain intact when formulating
 the encapsulating header. This fix handles the 'inherit' and
 'fixed-value' DSCP cases explicitly using the extant dsfield u8 variable.

2) The use of INET_ECN_encapsulate(0, dsfield) in ip6_tnl_xmit was
 incorrect and resulted in the DSCP value always being set to 0.

Signed-off-by: Peter Dawson <peter.a.dawson@boeing.com>
---
 net/ipv6/ip6_gre.c    | 13 +++++++------
 net/ipv6/ip6_tunnel.c | 21 +++++++++++++--------
 2 files changed, 20 insertions(+), 14 deletions(-)

diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index 8d128ba..0c5b4caa 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -537,11 +537,10 @@  static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
 
 	memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 
-	dsfield = ipv4_get_dsfield(iph);
-
 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
-		fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT)
-					  & IPV6_TCLASS_MASK;
+		dsfield = ipv4_get_dsfield(iph);
+	else
+		dsfield = ip6_tclass(t->parms.flowinfo);
 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
 		fl6.flowi6_mark = skb->mark;
 	else
@@ -598,9 +597,11 @@  static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev)
 
 	memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
 
-	dsfield = ipv6_get_dsfield(ipv6h);
 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
-		fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK);
+		dsfield = ipv6_get_dsfield(ipv6h);
+	else
+		dsfield = ip6_tclass(t->parms.flowinfo);
+
 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
 		fl6.flowlabel |= ip6_flowlabel(ipv6h);
 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 6eb2ae5..7ae6c50 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -1196,7 +1196,7 @@  int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield,
 	skb_push(skb, sizeof(struct ipv6hdr));
 	skb_reset_network_header(skb);
 	ipv6h = ipv6_hdr(skb);
-	ip6_flow_hdr(ipv6h, INET_ECN_encapsulate(0, dsfield),
+	ip6_flow_hdr(ipv6h, dsfield,
 		     ip6_make_flowlabel(net, skb, fl6->flowlabel, true, fl6));
 	ipv6h->hop_limit = hop_limit;
 	ipv6h->nexthdr = proto;
@@ -1231,8 +1231,6 @@  ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
 	if (tproto != IPPROTO_IPIP && tproto != 0)
 		return -1;
 
-	dsfield = ipv4_get_dsfield(iph);
-
 	if (t->parms.collect_md) {
 		struct ip_tunnel_info *tun_info;
 		const struct ip_tunnel_key *key;
@@ -1246,6 +1244,7 @@  ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
 		fl6.flowi6_proto = IPPROTO_IPIP;
 		fl6.daddr = key->u.ipv6.dst;
 		fl6.flowlabel = key->label;
+		dsfield = ip6_tclass(key->label);
 	} else {
 		if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 			encap_limit = t->parms.encap_limit;
@@ -1254,8 +1253,9 @@  ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
 		fl6.flowi6_proto = IPPROTO_IPIP;
 
 		if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
-			fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT)
-					 & IPV6_TCLASS_MASK;
+			dsfield = ipv4_get_dsfield(iph);
+		else
+			dsfield = ip6_tclass(t->parms.flowinfo);
 		if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
 			fl6.flowi6_mark = skb->mark;
 		else
@@ -1267,6 +1267,8 @@  ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
 	if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6))
 		return -1;
 
+	dsfield = INET_ECN_encapsulate(dsfield, ipv4_get_dsfield(iph));
+
 	skb_set_inner_ipproto(skb, IPPROTO_IPIP);
 
 	err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
@@ -1300,8 +1302,6 @@  ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
 	    ip6_tnl_addr_conflict(t, ipv6h))
 		return -1;
 
-	dsfield = ipv6_get_dsfield(ipv6h);
-
 	if (t->parms.collect_md) {
 		struct ip_tunnel_info *tun_info;
 		const struct ip_tunnel_key *key;
@@ -1315,6 +1315,7 @@  ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
 		fl6.flowi6_proto = IPPROTO_IPV6;
 		fl6.daddr = key->u.ipv6.dst;
 		fl6.flowlabel = key->label;
+		dsfield = ip6_tclass(key->label);
 	} else {
 		offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
 		/* ip6_tnl_parse_tlv_enc_lim() might have reallocated skb->head */
@@ -1337,7 +1338,9 @@  ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
 		fl6.flowi6_proto = IPPROTO_IPV6;
 
 		if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
-			fl6.flowlabel |= (*(__be32 *)ipv6h & IPV6_TCLASS_MASK);
+			dsfield = ipv6_get_dsfield(ipv6h);
+		else
+			dsfield = ip6_tclass(t->parms.flowinfo);
 		if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
 			fl6.flowlabel |= ip6_flowlabel(ipv6h);
 		if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
@@ -1351,6 +1354,8 @@  ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
 	if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6))
 		return -1;
 
+	dsfield = INET_ECN_encapsulate(dsfield, ipv6_get_dsfield(ipv6h));
+
 	skb_set_inner_ipproto(skb, IPPROTO_IPV6);
 
 	err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
-- 
2.7.4