feat: parse capabilities in /proc/pid/status

proc_status.go

@@ -83,6 +83,19 @@ type ProcStatus struct {
 
 	// CpusAllowedList: List of cpu cores processes are allowed to run on.
 	CpusAllowedList []uint64
+
+	// CapInh is the bitmap of inheritable capabilities
+	//
+	// See: https://www.kernel.org/doc/man-pages/online/pages/man7/capabilities.7.html
+	CapInh uint64
+	// CapPrm is the bitmap of permitted capabilities
+	CapPrm uint64
+	// CapEff is the bitmap of effective capabilities
+	CapEff uint64
+	// CapBnd is the bitmap of bounding capabilities
+	CapBnd uint64
+	// CapAmb is the bitmap of ambient capabilities
+	CapAmb uint64
 }
 
 // NewStatus returns the current status information of the process.
@@ -190,6 +203,36 @@ func (s *ProcStatus) fillStatus(k string, vString string, vUint uint64, vUintByt
 		s.NonVoluntaryCtxtSwitches = vUint
 	case "Cpus_allowed_list":
 		s.CpusAllowedList = calcCpusAllowedList(vString)
+	case "CapInh":
+		var err error
+		s.CapInh, err = strconv.ParseUint(vString, 16, 64)
+		if err != nil {
+			return err
+		}
+	case "CapPrm":
+		var err error
+		s.CapPrm, err = strconv.ParseUint(vString, 16, 64)
+		if err != nil {
+			return err
+		}
+	case "CapEff":
+		var err error
+		s.CapEff, err = strconv.ParseUint(vString, 16, 64)
+		if err != nil {
+			return err
+		}
+	case "CapBnd":
+		var err error
+		s.CapBnd, err = strconv.ParseUint(vString, 16, 64)
+		if err != nil {
+			return err
+		}
+	case "CapAmb":
+		var err error
+		s.CapAmb, err = strconv.ParseUint(vString, 16, 64)
+		if err != nil {
+			return err
+		}
 	}
 
 	return nil

proc_status_test.go

@@ -160,3 +160,31 @@ func TestNsPids(t *testing.T) {
 		t.Fatalf("unexpected NsPids (-want +got):\n%s", diff)
 	}
 }
+
+func TestCaps(t *testing.T) {
+	p, err := getProcFixtures(t).Proc(26231)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	s, err := p.NewStatus()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	for _, test := range []struct {
+		name string
+		want uint64
+		have uint64
+	}{
+		{name: "CapInh", want: 0x0000000000000000, have: s.CapInh},
+		{name: "CapPrm", want: 0x0000003fffffffff, have: s.CapPrm},
+		{name: "CapEff", want: 0x0000003fffffffff, have: s.CapEff},
+		{name: "CapBnd", want: 0x0000003fffffffff, have: s.CapBnd},
+		{name: "CapAmb", want: 0x0000000000000000, have: s.CapAmb},
+	} {
+		if test.want != test.have {
+			t.Errorf("want %s %d, have %d", test.name, test.want, test.have)
+		}
+	}
+}