5 files changed, 30 insertions, 1 deletions
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index 54410a1d4065..d8676dda7fa6 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -1732,6 +1732,15 @@ ndisc_notify - BOOLEAN
 	1 - Generate unsolicited neighbour advertisements when device is brought
 	    up or hardware address changes.
 
+ndisc_tclass - INTEGER
+	The IPv6 Traffic Class to use by default when sending IPv6 Neighbor
+	Discovery (Router Solicitation, Router Advertisement, Neighbor
+	Solicitation, Neighbor Advertisement, Redirect) messages.
+	These 8 bits can be interpreted as 6 high order bits holding the DSCP
+	value and 2 low order bits representing ECN (which you probably want
+	to leave cleared).
+	0 - (default)
+
 mldv1_unsolicited_report_interval - INTEGER
 	The interval in milliseconds in which the next unsolicited
 	MLDv1 report retransmit will take place.
diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index ea04ca024f0d..cb18c6290ca8 100644
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -73,6 +73,7 @@ struct ipv6_devconf {
 	__u32		enhanced_dad;
 	__u32		addr_gen_mode;
 	__s32		disable_policy;
+	__s32           ndisc_tclass;
 
 	struct ctl_table_header *sysctl_header;
 };
diff --git a/include/uapi/linux/ipv6.h b/include/uapi/linux/ipv6.h
index b22a9c4e1b12..9c0f4a92bcff 100644
--- a/include/uapi/linux/ipv6.h
+++ b/include/uapi/linux/ipv6.h
@@ -186,6 +186,7 @@ enum {
 	DEVCONF_ADDR_GEN_MODE,
 	DEVCONF_DISABLE_POLICY,
 	DEVCONF_ACCEPT_RA_RT_INFO_MIN_PLEN,
+	DEVCONF_NDISC_TCLASS,
 	DEVCONF_MAX
 };
 
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 6233e06fa35c..a6dffd65eb9d 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -5059,6 +5059,7 @@ static inline void ipv6_store_devconf(struct ipv6_devconf *cnf,
 	array[DEVCONF_ENHANCED_DAD] = cnf->enhanced_dad;
 	array[DEVCONF_ADDR_GEN_MODE] = cnf->addr_gen_mode;
 	array[DEVCONF_DISABLE_POLICY] = cnf->disable_policy;
+	array[DEVCONF_NDISC_TCLASS] = cnf->ndisc_tclass;
 }
 
 static inline size_t inet6_ifla6_size(void)
@@ -5986,6 +5987,7 @@ int addrconf_sysctl_disable_policy(struct ctl_table *ctl, int write,
 }
 
 static int minus_one = -1;
+static const int zero = 0;
 static const int one = 1;
 static const int two_five_five = 255;
 
@@ -6357,6 +6359,15 @@ static const struct ctl_table addrconf_sysctl[] = {
 		.proc_handler   = addrconf_sysctl_disable_policy,
 	},
 	{
+		.procname	= "ndisc_tclass",
+		.data		= &ipv6_devconf.ndisc_tclass,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= (void *)&zero,
+		.extra2		= (void *)&two_five_five,
+	},
+	{
 		/* sentinel */
 	}
 };
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index f9c3ffe04382..b3cea200c85e 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -427,12 +427,19 @@ static void ip6_nd_hdr(struct sk_buff *skb,
 		       int hop_limit, int len)
 {
 	struct ipv6hdr *hdr;
+	struct inet6_dev *idev;
+	unsigned tclass;
+
+	rcu_read_lock();
+	idev = __in6_dev_get(skb->dev);
+	tclass = idev ? idev->cnf.ndisc_tclass : 0;
+	rcu_read_unlock();
 
 	skb_push(skb, sizeof(*hdr));
 	skb_reset_network_header(skb);
 	hdr = ipv6_hdr(skb);
 
-	ip6_flow_hdr(hdr, 0, 0);
+	ip6_flow_hdr(hdr, tclass, 0);
 
 	hdr->payload_len = htons(len);
 	hdr->nexthdr = IPPROTO_ICMPV6;