platform: add nm_platform_link_get_ifi_flags() helper

Add helper nm_platform_link_get_ifi_flags() to access the
ifi-flags.

This replaces the internal API _link_get_flags() and makes it public.
However, the return value also allows to distinguish between errors
and valid flags.

Also, consider non-visible links. These are links that are in netlink,
but not visible in udev. The ifi-flags are inherrently netlink specific,
so it seems wrong to pretend that the link doesn't exist.

2 files changed, 30 insertions, 9 deletions

diff --git a/src/platform/nm-platform.c b/src/platform/nm-platform.c
index 494e2ddaf6..f0a80cb8b5 100644
--- a/src/platform/nm-platform.c
+++ b/src/platform/nm-platform.c
@@ -1217,13 +1217,29 @@ nm_platform_link_refresh (NMPlatform *self, int ifindex)
 	return TRUE;
 }
 
-static guint
-_link_get_flags (NMPlatform *self, int ifindex)
+int
+nm_platform_link_get_ifi_flags (NMPlatform *self,
+                                int ifindex,
+                                guint requested_flags)
 {
 	const NMPlatformLink *pllink;
 
-	pllink = nm_platform_link_get (self, ifindex);
-	return pllink ? pllink->n_ifi_flags : IFF_NOARP;
+	_CHECK_SELF (self, klass, -EINVAL);
+
+	if (ifindex <= 0)
+		return -EINVAL;
+
+	/* include invisible links (only in netlink, not udev). */
+	pllink = NMP_OBJECT_CAST_LINK (nm_platform_link_get_obj (self, ifindex, FALSE));
+	if (!pllink)
+		return -ENODEV;
+
+	/* Errors are signaled as negative values. That means, you cannot request
+	 * the most significant bit (2^31) with this API. Assert against that. */
+	nm_assert ((int) requested_flags >= 0);
+	nm_assert (requested_flags < (guint) G_MAXINT);
+
+	return (int) (pllink->n_ifi_flags & requested_flags);
 }
 
 /**
@@ -1236,9 +1252,7 @@ _link_get_flags (NMPlatform *self, int ifindex)
 gboolean
 nm_platform_link_is_up (NMPlatform *self, int ifindex)
 {
-	_CHECK_SELF (self, klass, FALSE);
-
-	return NM_FLAGS_HAS (_link_get_flags (self, ifindex), IFF_UP);
+	return nm_platform_link_get_ifi_flags (self, ifindex, IFF_UP) == IFF_UP;
 }
 
 /**
@@ -1269,9 +1283,15 @@ nm_platform_link_is_connected (NMPlatform *self, int ifindex)
 gboolean
 nm_platform_link_uses_arp (NMPlatform *self, int ifindex)
 {
-	_CHECK_SELF (self, klass, FALSE);
+	int f;
 
-	return !NM_FLAGS_HAS (_link_get_flags (self, ifindex), IFF_NOARP);
+	f = nm_platform_link_get_ifi_flags (self, ifindex, IFF_NOARP);
+
+	if (f < 0)
+		return FALSE;
+	if (f == IFF_NOARP)
+		return FALSE;
+	return TRUE;
 }
 
 /**
diff --git a/src/platform/nm-platform.h b/src/platform/nm-platform.h
index 2a18d8adf2..dff5102d85 100644
--- a/src/platform/nm-platform.h
+++ b/src/platform/nm-platform.h
@@ -1166,6 +1166,7 @@ int nm_platform_link_get_ifindex (NMPlatform *self, const char *name);
 const char *nm_platform_link_get_name (NMPlatform *self, int ifindex);
 NMLinkType nm_platform_link_get_type (NMPlatform *self, int ifindex);
 gboolean nm_platform_link_is_software (NMPlatform *self, int ifindex);
+int nm_platform_link_get_ifi_flags (NMPlatform *self, int ifindex, guint requested_flags);
 gboolean nm_platform_link_is_up (NMPlatform *self, int ifindex);
 gboolean nm_platform_link_is_connected (NMPlatform *self, int ifindex);
 gboolean nm_platform_link_uses_arp (NMPlatform *self, int ifindex);