1 files changed, 23 insertions, 8 deletions

diff --git a/include/net/inet_ecn.h b/include/net/inet_ecn.h
index e1eaf1780288..ea32393464a2 100644
--- a/include/net/inet_ecn.h
+++ b/include/net/inet_ecn.h
@@ -8,6 +8,7 @@
 
 #include <net/inet_sock.h>
 #include <net/dsfield.h>
+#include <net/checksum.h>
 
 enum {
 	INET_ECN_NOT_ECT = 0,
@@ -75,8 +76,8 @@ static inline void INET_ECN_dontxmit(struct sock *sk)
 
 static inline int IP_ECN_set_ce(struct iphdr *iph)
 {
-	u32 check = (__force u32)iph->check;
 	u32 ecn = (iph->tos + 1) & INET_ECN_MASK;
+	__be16 check_add;
 
 	/*
 	 * After the last operation we have (in binary):
@@ -93,23 +94,20 @@ static inline int IP_ECN_set_ce(struct iphdr *iph)
 	 * INET_ECN_ECT_1 => check += htons(0xFFFD)
 	 * INET_ECN_ECT_0 => check += htons(0xFFFE)
 	 */
-	check += (__force u16)htons(0xFFFB) + (__force u16)htons(ecn);
+	check_add = (__force __be16)((__force u16)htons(0xFFFB) +
+				     (__force u16)htons(ecn));
 
-	iph->check = (__force __sum16)(check + (check>=0xFFFF));
+	iph->check = csum16_add(iph->check, check_add);
 	iph->tos |= INET_ECN_CE;
 	return 1;
 }
 
 static inline int IP_ECN_set_ect1(struct iphdr *iph)
 {
-	u32 check = (__force u32)iph->check;
-
 	if ((iph->tos & INET_ECN_MASK) != INET_ECN_ECT_0)
 		return 0;
 
-	check += (__force u16)htons(0x100);
-
-	iph->check = (__force __sum16)(check + (check>=0xFFFF));
+	iph->check = csum16_add(iph->check, htons(0x1));
 	iph->tos ^= INET_ECN_MASK;
 	return 1;
 }
@@ -190,6 +188,23 @@ static inline int INET_ECN_set_ce(struct sk_buff *skb)
 	return 0;
 }
 
+static inline int skb_get_dsfield(struct sk_buff *skb)
+{
+	switch (skb_protocol(skb, true)) {
+	case cpu_to_be16(ETH_P_IP):
+		if (!pskb_network_may_pull(skb, sizeof(struct iphdr)))
+			break;
+		return ipv4_get_dsfield(ip_hdr(skb));
+
+	case cpu_to_be16(ETH_P_IPV6):
+		if (!pskb_network_may_pull(skb, sizeof(struct ipv6hdr)))
+			break;
+		return ipv6_get_dsfield(ipv6_hdr(skb));
+	}
+
+	return -1;
+}
+
 static inline int INET_ECN_set_ect1(struct sk_buff *skb)
 {
 	switch (skb_protocol(skb, true)) {