2 files changed, 16 insertions, 0 deletions
diff --git a/src/libsystemd-network/network-internal.c b/src/libsystemd-network/network-internal.c
index 52e614c4ea..e7ba628fc7 100644
--- a/src/libsystemd-network/network-internal.c
+++ b/src/libsystemd-network/network-internal.c
@@ -326,3 +326,17 @@ int net_parse_inaddr(const char *address, unsigned char *family, void *dst) {
 
         return 0;
 }
+
+bool link_has_carrier(unsigned flags, uint8_t operstate) {
+        /* see Documentation/networking/operstates.txt in the kernel sources */
+
+        if (operstate == IF_OPER_UP)
+                return true;
+
+        if (operstate == IF_OPER_UNKNOWN)
+                /* operstate may not be implemented, so fall back to flags */
+                if ((flags & IFF_LOWER_UP) && !(flags & IFF_DORMANT))
+                        return true;
+
+        return false;
+}
diff --git a/src/libsystemd-network/network-internal.h b/src/libsystemd-network/network-internal.h
index 836472a776..ef3cb8b91d 100644
--- a/src/libsystemd-network/network-internal.h
+++ b/src/libsystemd-network/network-internal.h
@@ -65,3 +65,5 @@ int config_parse_ifalias(const char *unit, const char *filename, unsigned line,
 int net_parse_inaddr(const char *address, unsigned char *family, void *dst);
 
 int net_get_unique_predictable_data(struct udev_device *device, uint8_t result[8]);
+
+bool link_has_carrier(unsigned flags, uint8_t operstate);