1 files changed, 239 insertions, 0 deletions
diff --git a/vendor/github.com/cilium/ebpf/info.go b/vendor/github.com/cilium/ebpf/info.go
new file mode 100644
index 000000000..b95131ef5
--- /dev/null
+++ b/vendor/github.com/cilium/ebpf/info.go
@@ -0,0 +1,239 @@
+package ebpf
+
+import (
+	"bufio"
+	"encoding/hex"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"strings"
+	"syscall"
+	"time"
+
+	"github.com/cilium/ebpf/internal"
+)
+
+// MapInfo describes a map.
+type MapInfo struct {
+	Type       MapType
+	id         MapID
+	KeySize    uint32
+	ValueSize  uint32
+	MaxEntries uint32
+	Flags      uint32
+	// Name as supplied by user space at load time.
+	Name string
+}
+
+func newMapInfoFromFd(fd *internal.FD) (*MapInfo, error) {
+	info, err := bpfGetMapInfoByFD(fd)
+	if errors.Is(err, syscall.EINVAL) {
+		return newMapInfoFromProc(fd)
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	return &MapInfo{
+		MapType(info.map_type),
+		MapID(info.id),
+		info.key_size,
+		info.value_size,
+		info.max_entries,
+		info.map_flags,
+		// name is available from 4.15.
+		internal.CString(info.name[:]),
+	}, nil
+}
+
+func newMapInfoFromProc(fd *internal.FD) (*MapInfo, error) {
+	var mi MapInfo
+	err := scanFdInfo(fd, map[string]interface{}{
+		"map_type":    &mi.Type,
+		"key_size":    &mi.KeySize,
+		"value_size":  &mi.ValueSize,
+		"max_entries": &mi.MaxEntries,
+		"map_flags":   &mi.Flags,
+	})
+	if err != nil {
+		return nil, err
+	}
+	return &mi, nil
+}
+
+// ID returns the map ID.
+//
+// Available from 4.13.
+//
+// The bool return value indicates whether this optional field is available.
+func (mi *MapInfo) ID() (MapID, bool) {
+	return mi.id, mi.id > 0
+}
+
+// programStats holds statistics of a program.
+type programStats struct {
+	// Total accumulated runtime of the program ins ns.
+	runtime time.Duration
+	// Total number of times the program was called.
+	runCount uint64
+}
+
+// ProgramInfo describes a program.
+type ProgramInfo struct {
+	Type ProgramType
+	id   ProgramID
+	// Truncated hash of the BPF bytecode.
+	Tag string
+	// Name as supplied by user space at load time.
+	Name string
+
+	stats *programStats
+}
+
+func newProgramInfoFromFd(fd *internal.FD) (*ProgramInfo, error) {
+	info, err := bpfGetProgInfoByFD(fd)
+	if errors.Is(err, syscall.EINVAL) {
+		return newProgramInfoFromProc(fd)
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	return &ProgramInfo{
+		Type: ProgramType(info.prog_type),
+		id:   ProgramID(info.id),
+		// tag is available if the kernel supports BPF_PROG_GET_INFO_BY_FD.
+		Tag: hex.EncodeToString(info.tag[:]),
+		// name is available from 4.15.
+		Name: internal.CString(info.name[:]),
+		stats: &programStats{
+			runtime:  time.Duration(info.run_time_ns),
+			runCount: info.run_cnt,
+		},
+	}, nil
+}
+
+func newProgramInfoFromProc(fd *internal.FD) (*ProgramInfo, error) {
+	var info ProgramInfo
+	err := scanFdInfo(fd, map[string]interface{}{
+		"prog_type": &info.Type,
+		"prog_tag":  &info.Tag,
+	})
+	if errors.Is(err, errMissingFields) {
+		return nil, &internal.UnsupportedFeatureError{
+			Name:           "reading program info from /proc/self/fdinfo",
+			MinimumVersion: internal.Version{4, 10, 0},
+		}
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	return &info, nil
+}
+
+// ID returns the program ID.
+//
+// Available from 4.13.
+//
+// The bool return value indicates whether this optional field is available.
+func (pi *ProgramInfo) ID() (ProgramID, bool) {
+	return pi.id, pi.id > 0
+}
+
+// RunCount returns the total number of times the program was called.
+//
+// Can return 0 if the collection of statistics is not enabled. See EnableStats().
+// The bool return value indicates whether this optional field is available.
+func (pi *ProgramInfo) RunCount() (uint64, bool) {
+	if pi.stats != nil {
+		return pi.stats.runCount, true
+	}
+	return 0, false
+}
+
+// Runtime returns the total accumulated runtime of the program.
+//
+// Can return 0 if the collection of statistics is not enabled. See EnableStats().
+// The bool return value indicates whether this optional field is available.
+func (pi *ProgramInfo) Runtime() (time.Duration, bool) {
+	if pi.stats != nil {
+		return pi.stats.runtime, true
+	}
+	return time.Duration(0), false
+}
+
+func scanFdInfo(fd *internal.FD, fields map[string]interface{}) error {
+	raw, err := fd.Value()
+	if err != nil {
+		return err
+	}
+
+	fh, err := os.Open(fmt.Sprintf("/proc/self/fdinfo/%d", raw))
+	if err != nil {
+		return err
+	}
+	defer fh.Close()
+
+	if err := scanFdInfoReader(fh, fields); err != nil {
+		return fmt.Errorf("%s: %w", fh.Name(), err)
+	}
+	return nil
+}
+
+var errMissingFields = errors.New("missing fields")
+
+func scanFdInfoReader(r io.Reader, fields map[string]interface{}) error {
+	var (
+		scanner = bufio.NewScanner(r)
+		scanned int
+	)
+
+	for scanner.Scan() {
+		parts := strings.SplitN(scanner.Text(), "\t", 2)
+		if len(parts) != 2 {
+			continue
+		}
+
+		name := strings.TrimSuffix(parts[0], ":")
+		field, ok := fields[string(name)]
+		if !ok {
+			continue
+		}
+
+		if n, err := fmt.Sscanln(parts[1], field); err != nil || n != 1 {
+			return fmt.Errorf("can't parse field %s: %v", name, err)
+		}
+
+		scanned++
+	}
+
+	if err := scanner.Err(); err != nil {
+		return err
+	}
+
+	if scanned != len(fields) {
+		return errMissingFields
+	}
+
+	return nil
+}
+
+// EnableStats starts the measuring of the runtime
+// and run counts of eBPF programs.
+//
+// Collecting statistics can have an impact on the performance.
+//
+// Requires at least 5.8.
+func EnableStats(which uint32) (io.Closer, error) {
+	attr := internal.BPFEnableStatsAttr{
+		StatsType: which,
+	}
+
+	fd, err := internal.BPFEnableStats(&attr)
+	if err != nil {
+		return nil, err
+	}
+	return fd, nil
+}