1 files changed, 10 insertions, 1 deletions
diff --git a/src/lib.rs b/src/lib.rs
index 26af39a..2d47db2 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -15,6 +15,7 @@ use tokio::runtime::Runtime;
 pub enum Error {
     RtNetlink(rtnetlink::Error),
     IoError(std::io::Error),
+    LinkNotFound(Option<String>),
 }
 
 impl std::error::Error for Error {}
@@ -24,6 +25,10 @@ impl fmt::Display for Error {
         match self {
             Self::RtNetlink(e) => write!(fmt, "rtnetlink error: {}", e),
             Self::IoError(e) => write!(fmt, "rtnetlink connection failed: {}", e),
+            Self::LinkNotFound(filter) => match filter {
+                Some(link) => write!(fmt, "link not found: {}", link),
+                None => write!(fmt, "no links found"),
+            },
         }
     }
 }
@@ -166,5 +171,9 @@ async fn internal_addresses(filter: Option<String>) -> Result<Vec<IpNet>> {
         num_links.add_assign(1);
     }
 
-    Ok(link_addrs)
+    if num_links > 0 {
+        Ok(link_addrs)
+    } else {
+        Err(Error::LinkNotFound(filter))
+    }
 }