sysfs: add link_layer property to InfiniBandPort

Signed-off-by: Thomas Barrett <thomas@fluidstack.io>

Author: Thomas Barrett

sysfs/class_infiniband.go

@@ -107,6 +107,7 @@ type InfiniBandHwCounters struct {
 // /sys/class/infiniband/<Name>/ports/<Port>
 // for a single port of one InfiniBand device.
 type InfiniBandPort struct {
+	LinkLayer   string
 	Name        string
 	Port        uint
 	State       string // String representation from /sys/class/infiniband/<Name>/ports/<Port>/state
@@ -248,6 +249,13 @@ func (fs FS) parseInfiniBandPort(name string, port string) (*InfiniBandPort, err
 	ibp := InfiniBandPort{Name: name, Port: uint(portNumber)}
 
 	portPath := fs.sys.Path(infinibandClassPath, name, "ports", port)
+
+	linkLayer, err := os.ReadFile(filepath.Join(portPath, "link_layer"))
+	if err != nil {
+		return nil, err
+	}
+	ibp.LinkLayer = strings.TrimSpace(string(linkLayer))
+
 	content, err := os.ReadFile(filepath.Join(portPath, "state"))
 	if err != nil {
 		return nil, err

sysfs/class_infiniband_test.go

@@ -174,6 +174,7 @@ func TestInfiniBandClass(t *testing.T) {
 			HCAType:         "",
 			Ports: map[uint]InfiniBandPort{
 				1: {
+					LinkLayer:   "InfiniBand",
 					Name:        "hfi1_0",
 					Port:        1,
 					State:       "ACTIVE",
@@ -210,6 +211,7 @@ func TestInfiniBandClass(t *testing.T) {
 			HCAType:         "MT4099",
 			Ports: map[uint]InfiniBandPort{
 				1: {
+					LinkLayer:   "InfiniBand",
 					Name:        "mlx4_0",
 					Port:        1,
 					State:       "ACTIVE",
@@ -238,6 +240,7 @@ func TestInfiniBandClass(t *testing.T) {
 					},
 				},
 				2: {
+					LinkLayer:   "InfiniBand",
 					Name:        "mlx4_0",
 					Port:        2,
 					State:       "ACTIVE",
@@ -274,6 +277,7 @@ func TestInfiniBandClass(t *testing.T) {
 			HCAType:         "MT4118",
 			Ports: map[uint]InfiniBandPort{
 				1: {
+					LinkLayer:   "InfiniBand",
 					Name:        "mlx5_0",
 					Port:        1,
 					State:       "ACTIVE",

testdata/fixtures.ttar

@@ -5758,6 +5758,11 @@ Lines: 1
 100 Gb/sec (4X EDR)
 Mode: 644
 # ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+Path: fixtures/sys/class/infiniband/hfi1_0/ports/1/link_layer
+Lines: 1
+InfiniBand
+Mode: 644
+# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 Path: fixtures/sys/class/infiniband/hfi1_0/ports/1/state
 Lines: 1
 4: ACTIVE
@@ -5885,6 +5890,11 @@ Lines: 1
 40 Gb/sec (4X QDR)
 Mode: 644
 # ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+Path: fixtures/sys/class/infiniband/mlx4_0/ports/1/link_layer
+Lines: 1
+InfiniBand
+Mode: 644
+# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 Path: fixtures/sys/class/infiniband/mlx4_0/ports/1/state
 Lines: 1
 4: ACTIVE
@@ -6266,6 +6276,11 @@ Lines: 1
 25 Gb/sec (1X EDR)
 Mode: 644
 # ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+Path: fixtures/sys/class/infiniband/mlx5_0/ports/1/link_layer
+Lines: 1
+InfiniBand
+Mode: 644
+# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 Path: fixtures/sys/class/infiniband/mlx5_0/ports/1/state
 Lines: 1
 4: ACTIVE