diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index e6215bdd96c0a4063a92b6ee35355872a1785f81..a1151b8adf3c6d65409ea8944973432187e49fe0 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -45,6 +45,7 @@
 #include <linux/udp.h>
 #include <linux/inet.h>
 #include <linux/netfilter_ipv4.h>
+#include <net/inet_ecn.h>
 
 /* NOTE. Logic of IP defragmentation is parallel to corresponding IPv6
  * code now. If you change something here, _PLEASE_ update ipv6/reassembly.c
@@ -70,11 +71,28 @@ struct ipq {
 	__be32		daddr;
 	__be16		id;
 	u8		protocol;
+	u8		ecn; /* RFC3168 support */
 	int             iif;
 	unsigned int    rid;
 	struct inet_peer *peer;
 };
 
+#define IPFRAG_ECN_CLEAR  0x01 /* one frag had INET_ECN_NOT_ECT */
+#define IPFRAG_ECN_SET_CE 0x04 /* one frag had INET_ECN_CE */
+
+static inline u8 ip4_frag_ecn(u8 tos)
+{
+	tos = (tos & INET_ECN_MASK) + 1;
+	/*
+	 * After the last operation we have (in binary):
+	 * INET_ECN_NOT_ECT => 001
+	 * INET_ECN_ECT_1   => 010
+	 * INET_ECN_ECT_0   => 011
+	 * INET_ECN_CE      => 100
+	 */
+	return (tos & 2) ? 0 : tos;
+}
+
 static struct inet_frags ip4_frags;
 
 int ip_frag_nqueues(struct net *net)
@@ -137,6 +155,7 @@ static void ip4_frag_init(struct inet_frag_queue *q, void *a)
 
 	qp->protocol = arg->iph->protocol;
 	qp->id = arg->iph->id;
+	qp->ecn = ip4_frag_ecn(arg->iph->tos);
 	qp->saddr = arg->iph->saddr;
 	qp->daddr = arg->iph->daddr;
 	qp->user = arg->user;
@@ -316,6 +335,7 @@ static int ip_frag_reinit(struct ipq *qp)
 	qp->q.fragments = NULL;
 	qp->q.fragments_tail = NULL;
 	qp->iif = 0;
+	qp->ecn = 0;
 
 	return 0;
 }
@@ -328,6 +348,7 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
 	int flags, offset;
 	int ihl, end;
 	int err = -ENOENT;
+	u8 ecn;
 
 	if (qp->q.last_in & INET_FRAG_COMPLETE)
 		goto err;
@@ -339,6 +360,7 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
 		goto err;
 	}
 
+	ecn = ip4_frag_ecn(ip_hdr(skb)->tos);
 	offset = ntohs(ip_hdr(skb)->frag_off);
 	flags = offset & ~IP_OFFSET;
 	offset &= IP_OFFSET;
@@ -472,6 +494,7 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
 	}
 	qp->q.stamp = skb->tstamp;
 	qp->q.meat += skb->len;
+	qp->ecn |= ecn;
 	atomic_add(skb->truesize, &qp->q.net->mem);
 	if (offset == 0)
 		qp->q.last_in |= INET_FRAG_FIRST_IN;
@@ -583,6 +606,17 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
 	iph = ip_hdr(head);
 	iph->frag_off = 0;
 	iph->tot_len = htons(len);
+	/* RFC3168 5.3 Fragmentation support
+	 * If one fragment had INET_ECN_NOT_ECT,
+	 *	reassembled frame also has INET_ECN_NOT_ECT
+	 * Elif one fragment had INET_ECN_CE
+	 *	reassembled frame also has INET_ECN_CE
+	 */
+	if (qp->ecn & IPFRAG_ECN_CLEAR)
+		iph->tos &= ~INET_ECN_MASK;
+	else if (qp->ecn & IPFRAG_ECN_SET_CE)
+		iph->tos |= INET_ECN_CE;
+
 	IP_INC_STATS_BH(net, IPSTATS_MIB_REASMOKS);
 	qp->q.fragments = NULL;
 	qp->q.fragments_tail = NULL;