netpoll: prepare for ipv6

This patch adjusts some struct and functions, to prepare
for supporting IPv6.

Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
index 6989ebe..998fa02 100644
--- a/drivers/net/netconsole.c
+++ b/drivers/net/netconsole.c
@@ -269,12 +269,14 @@
 
 static ssize_t show_local_ip(struct netconsole_target *nt, char *buf)
 {
-	return snprintf(buf, PAGE_SIZE, "%pI4\n", &nt->np.local_ip);
+	if (!nt->np.ipv6)
+		return snprintf(buf, PAGE_SIZE, "%pI4\n", &nt->np.local_ip);
 }
 
 static ssize_t show_remote_ip(struct netconsole_target *nt, char *buf)
 {
-	return snprintf(buf, PAGE_SIZE, "%pI4\n", &nt->np.remote_ip);
+	if (!nt->np.ipv6)
+		return snprintf(buf, PAGE_SIZE, "%pI4\n", &nt->np.remote_ip);
 }
 
 static ssize_t show_local_mac(struct netconsole_target *nt, char *buf)
@@ -410,7 +412,8 @@
 		return -EINVAL;
 	}
 
-	nt->np.local_ip = in_aton(buf);
+	if (!strnchr(buf, count, ':'))
+		nt->np.local_ip.ip = in_aton(buf);
 
 	return strnlen(buf, count);
 }
@@ -426,7 +429,8 @@
 		return -EINVAL;
 	}
 
-	nt->np.remote_ip = in_aton(buf);
+	if (!strnchr(buf, count, ':'))
+		nt->np.remote_ip.ip = in_aton(buf);
 
 	return strnlen(buf, count);
 }