net: Introduce ipv4_addr_hash and use it for tcp metrics

Refactors a common line into helper function.
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/net/ip.h

@@ -458,6 +458,11 @@ static __inline__ void inet_reset_saddr(struct sock *sk)
 
 #endif
 
+static inline unsigned int ipv4_addr_hash(__be32 ip)
+{
+	return (__force unsigned int) ip;
+}
+
 bool ip_call_ra_chain(struct sk_buff *skb);
 
 /*

net/ipv4/tcp_metrics.c

@@ -249,7 +249,7 @@ static struct tcp_metrics_block *__tcp_get_metrics_req(struct request_sock *req,
 	case AF_INET:
 		saddr.addr.a4 = inet_rsk(req)->ir_loc_addr;
 		daddr.addr.a4 = inet_rsk(req)->ir_rmt_addr;
-		hash = (__force unsigned int) daddr.addr.a4;
+		hash = ipv4_addr_hash(inet_rsk(req)->ir_rmt_addr);
 		break;
 #if IS_ENABLED(CONFIG_IPV6)
 	case AF_INET6:
@@ -289,7 +289,7 @@ static struct tcp_metrics_block *__tcp_get_metrics_tw(struct inet_timewait_sock
 		saddr.addr.a4 = tw->tw_rcv_saddr;
 		daddr.family = AF_INET;
 		daddr.addr.a4 = tw->tw_daddr;
-		hash = (__force unsigned int) daddr.addr.a4;
+		hash = ipv4_addr_hash(tw->tw_daddr);
 	}
 #if IS_ENABLED(CONFIG_IPV6)
 	else if (tw->tw_family == AF_INET6) {
@@ -298,7 +298,7 @@ static struct tcp_metrics_block *__tcp_get_metrics_tw(struct inet_timewait_sock
 			saddr.addr.a4 = tw->tw_rcv_saddr;
 			daddr.family = AF_INET;
 			daddr.addr.a4 = tw->tw_daddr;
-			hash = (__force unsigned int) daddr.addr.a4;
+			hash = ipv4_addr_hash(tw->tw_daddr);
 		} else {
 			saddr.family = AF_INET6;
 			saddr.addr.in6 = tw->tw_v6_rcv_saddr;
@@ -339,7 +339,7 @@ static struct tcp_metrics_block *tcp_get_metrics(struct sock *sk,
 		saddr.addr.a4 = inet_sk(sk)->inet_saddr;
 		daddr.family = AF_INET;
 		daddr.addr.a4 = inet_sk(sk)->inet_daddr;
-		hash = (__force unsigned int) daddr.addr.a4;
+		hash = ipv4_addr_hash(inet_sk(sk)->inet_daddr);
 	}
 #if IS_ENABLED(CONFIG_IPV6)
 	else if (sk->sk_family == AF_INET6) {
@@ -348,7 +348,7 @@ static struct tcp_metrics_block *tcp_get_metrics(struct sock *sk,
 			saddr.addr.a4 = inet_sk(sk)->inet_saddr;
 			daddr.family = AF_INET;
 			daddr.addr.a4 = inet_sk(sk)->inet_daddr;
-			hash = (__force unsigned int) daddr.addr.a4;
+			hash = ipv4_addr_hash(inet_sk(sk)->inet_daddr);
 		} else {
 			saddr.family = AF_INET6;
 			saddr.addr.in6 = sk->sk_v6_rcv_saddr;
@@ -959,7 +959,7 @@ static int __parse_nl_addr(struct genl_info *info, struct inetpeer_addr *addr,
 		addr->family = AF_INET;
 		addr->addr.a4 = nla_get_in_addr(a);
 		if (hash)
-			*hash = (__force unsigned int) addr->addr.a4;
+			*hash = ipv4_addr_hash(addr->addr.a4);
 		return 0;
 	}
 	a = info->attrs[v6];