tcp: metrics: New netlink attribute for src IP and dumped in netlink reply

This patch adds a new netlink attribute for the source-IP and appends it
to the netlink reply. Now, iproute2 can have access to the source-IP.

Signed-off-by: Christoph Paasch <christoph.paasch@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/uapi/linux/tcp_metrics.h

@@ -35,6 +35,8 @@ enum {
 	TCP_METRICS_ATTR_FOPEN_SYN_DROPS,	/* u16, count of drops */
 	TCP_METRICS_ATTR_FOPEN_SYN_DROP_TS,	/* msecs age */
 	TCP_METRICS_ATTR_FOPEN_COOKIE,		/* binary */
+	TCP_METRICS_ATTR_SADDR_IPV4,		/* u32 */
+	TCP_METRICS_ATTR_SADDR_IPV6,		/* binary */
 
 	__TCP_METRICS_ATTR_MAX,
 };

net/ipv4/tcp_metrics.c

@@ -745,11 +745,17 @@ static int tcp_metrics_fill_info(struct sk_buff *msg,
 		if (nla_put_be32(msg, TCP_METRICS_ATTR_ADDR_IPV4,
 				tm->tcpm_daddr.addr.a4) < 0)
 			goto nla_put_failure;
+		if (nla_put_be32(msg, TCP_METRICS_ATTR_SADDR_IPV4,
+				tm->tcpm_saddr.addr.a4) < 0)
+			goto nla_put_failure;
 		break;
 	case AF_INET6:
 		if (nla_put(msg, TCP_METRICS_ATTR_ADDR_IPV6, 16,
 			    tm->tcpm_daddr.addr.a6) < 0)
 			goto nla_put_failure;
+		if (nla_put(msg, TCP_METRICS_ATTR_SADDR_IPV6, 16,
+			    tm->tcpm_saddr.addr.a6) < 0)
+			goto nla_put_failure;
 		break;
 	default:
 		return -EAFNOSUPPORT;