1 files changed, 148 insertions, 0 deletions
diff --git a/packages/numap/internal/hwids/hwids.go b/packages/numap/internal/hwids/hwids.go
new file mode 100644
index 0000000..6aa9d8a
--- /dev/null
+++ b/packages/numap/internal/hwids/hwids.go
@@ -0,0 +1,148 @@
+package hwids
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strings"
+)
+
+var pciPath = []string{
+	"/usr/share/hwdata/pci.ids",
+	"/usr/share/misc/pci.ids",
+}
+
+type PCIType int
+
+const (
+	PCIVendor PCIType = iota
+	PCIDevice
+	PCISubsystem
+)
+
+type PciDevices map[uint16][]PciDevice
+
+// PciDevice represents a PCI device
+type PciDevice struct {
+	Type                   PCIType
+	Vendor, Device         uint16
+	SubVendor, SubDevice   uint16
+	VendorName, DeviceName string
+	SubName                string
+}
+
+// Load load the hardware database for PCI devices and return a map of
+// vendor -> list of devices.
+func Load() (PciDevices, error) {
+	// if the environment variable HWDATAPATH is set, we add it to the
+	// list of paths we check for the hardware database.
+	extraPath := os.Getenv("HWDATA")
+	if extraPath != "" {
+		pciPath = append(pciPath, extraPath)
+	}
+
+	for _, f := range pciPath {
+		fh, err := os.Open(f)
+		if err != nil {
+			continue
+		}
+		defer fh.Close()
+		return parse(fh)
+	}
+	return PciDevices{}, fmt.Errorf("hwids: could not find a pci.ids file")
+}
+
+func parse(f *os.File) (PciDevices, error) {
+	devices := make(PciDevices)
+
+	s := bufio.NewScanner(f)
+
+	// this is to keep track of the current device. The format of the
+	// file is as follow:
+	// vendor  vendor_name
+	//       device  device_name                             <-- single tab
+	//               subvendor subdevice  subsystem_name     <-- two tabs
+	// the variable is to keep track of the current vendor / device
+	cur := PciDevice{}
+
+	for s.Scan() {
+		l := s.Text()
+		// skip empty lines or lines that are a comment
+		if len(l) == 0 || l[0] == '#' {
+			continue
+		}
+		// lines starting with a C are the classes definitions, and
+		// they are at the end of the file, which means we're done
+		// parsing the devices
+		if l[0] == 'C' {
+			break
+		}
+
+		parts := strings.SplitN(l, "  ", 2)
+		if len(parts) != 2 {
+			return devices, fmt.Errorf("hwids: malformed PCI ID line (missing ID separator): %s", l)
+		}
+
+		ids, name := parts[0], parts[1]
+		if len(ids) < 2 || len(name) == 0 {
+			return devices, fmt.Errorf("hwids: malformed PCI ID line (empty ID or name): %s", l)
+		}
+
+		cur.Type = PCIVendor
+
+		if ids[0] == '\t' {
+			if ids[1] == '\t' {
+				cur.Type = PCISubsystem
+			} else {
+				cur.Type = PCIDevice
+			}
+		}
+
+		var err error
+		switch cur.Type {
+		case PCIVendor:
+			_, err = fmt.Sscanf(ids, "%x", &cur.Vendor)
+			cur.VendorName = name
+		case PCIDevice:
+			_, err = fmt.Sscanf(ids, "%x", &cur.Device)
+			cur.DeviceName = name
+		case PCISubsystem:
+			_, err = fmt.Sscanf(ids, "%x %x", &cur.SubVendor, &cur.SubDevice)
+			cur.SubName = name
+		}
+
+		if err != nil {
+			return devices, fmt.Errorf("hwids: malformed PCI ID line: %s: %v", l, err)
+		}
+
+		// This is to reset the state when we are moving to a
+		// different vendor or device
+		switch cur.Type {
+		case PCIVendor:
+			cur.Device = 0
+			cur.DeviceName = ""
+			fallthrough
+		case PCIDevice:
+			cur.SubVendor = 0
+			cur.SubDevice = 0
+			cur.SubName = ""
+		}
+
+		_, ok := devices[cur.Vendor]
+		if ok {
+			_devices := devices[cur.Vendor]
+			_devices = append(_devices, cur)
+			devices[cur.Vendor] = _devices
+
+		} else {
+			_devices := []PciDevice{cur}
+			devices[cur.Vendor] = _devices
+		}
+	}
+
+	if err := s.Err(); err != nil {
+		return devices, fmt.Errorf("hwids: failed to read PCI ID line: %v", err)
+	}
+
+	return devices, nil
+}