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Add support for IFLA_MIN_MTU and IFLA_MAX_MTU in LinkAttrs #1102

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Add support for IFLA_MIN_MTU and IFLA_MAX_MTU in LinkAttrs #1102

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2 changes: 2 additions & 0 deletions link.go
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Original file line number Diff line number Diff line change
Expand Up @@ -24,6 +24,8 @@ type (
type LinkAttrs struct {
Index int
MTU int
MinMTU int
MaxMTU int
TxQLen int // Transmit Queue Length
Name string
HardwareAddr net.HardwareAddr
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4 changes: 4 additions & 0 deletions link_linux.go
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Expand Up @@ -2248,6 +2248,10 @@ func LinkDeserialize(hdr *unix.NlMsghdr, m []byte) (Link, error) {
base.Name = string(attr.Value[:len(attr.Value)-1])
case unix.IFLA_MTU:
base.MTU = int(native.Uint32(attr.Value[0:4]))
case unix.IFLA_MIN_MTU:
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@AlekseyMamedoff
Shouldn't you also add a corresponding method LinkSetMinMTU

If you are adding functionality to parse this attribute via netlink, we should also be able to add it to Links

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@lazysegtree lazysegtree Jul 23, 2025 •
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Also a unit test would be great. Something like

func TestLinkMinMaxMTU(t *testing.T) {
	tearDown := setUpNetlinkTest(t)
	defer tearDown()

	iface := &Dummy{LinkAttrs{
		Name: "foo",
	}}
	if err := LinkAdd(iface); err != nil {
		t.Fatal(err)
	}

	link, err := LinkByName("foo")
	err = LinkSetMinMTU(link, 1000)
	if link.Attrs().MinMTU != 1000 {
		t.Fatal("MinMTU not correct")
	}
}

base.MinMTU = int(native.Uint32(attr.Value[0:4]))
case unix.IFLA_MAX_MTU:
base.MaxMTU = int(native.Uint32(attr.Value[0:4]))
case unix.IFLA_PROMISCUITY:
base.Promisc = int(native.Uint32(attr.Value[0:4]))
case unix.IFLA_LINK:
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