apparmor: fix version checks to work properly

Using {{if major}}{{if minor}} doesn't work as expected when the major
version changes. In addition, this didn't support patch levels (which is
necessary in some cases when distributions ship apparmor weirdly).

Signed-off-by: Aleksa Sarai <asarai@suse.com>

aaparser/aaparser.go

@@ -14,13 +14,13 @@ const (
 )
 
 // GetVersion returns the major and minor version of apparmor_parser.
-func GetVersion() (int, int, error) {
+func GetVersion() (int, error) {
 	output, err := cmd("", "--version")
 	if err != nil {
-		return -1, -1, err
+		return -1, err
 	}
 
-	return parseVersion(string(output))
+	return parseVersion(output)
 }
 
 // LoadProfile runs `apparmor_parser -r -W` on a specified apparmor profile to
@@ -47,30 +47,46 @@ func cmd(dir string, arg ...string) (string, error) {
 }
 
 // parseVersion takes the output from `apparmor_parser --version` and returns
-// the major and minor version for `apparor_parser`.
-func parseVersion(output string) (int, int, error) {
+// a representation of the {major, minor, patch} version as a single number of
+// the form MMmmPPP {major, minor, patch}.
+func parseVersion(output string) (int, error) {
 	// output is in the form of the following:
 	// AppArmor parser version 2.9.1
 	// Copyright (C) 1999-2008 Novell Inc.
 	// Copyright 2009-2012 Canonical Ltd.
+
 	lines := strings.SplitN(output, "\n", 2)
 	words := strings.Split(lines[0], " ")
 	version := words[len(words)-1]
 
 	// split by major minor version
 	v := strings.Split(version, ".")
-	if len(v) < 2 {
-		return -1, -1, fmt.Errorf("parsing major minor version failed for output: `%s`", output)
+	if len(v) == 0 || len(v) > 3 {
+		return -1, fmt.Errorf("parsing version failed for output: `%s`", output)
 	}
 
+	// Default the versions to 0.
+	var majorVersion, minorVersion, patchLevel int
+
 	majorVersion, err := strconv.Atoi(v[0])
 	if err != nil {
-		return -1, -1, err
-	}
-	minorVersion, err := strconv.Atoi(v[1])
-	if err != nil {
-		return -1, -1, err
+		return -1, err
 	}
 
-	return majorVersion, minorVersion, nil
+	if len(v) > 1 {
+		minorVersion, err = strconv.Atoi(v[1])
+		if err != nil {
+			return -1, err
+		}
+	}
+	if len(v) > 2 {
+		patchLevel, err = strconv.Atoi(v[2])
+		if err != nil {
+			return -1, err
+		}
+	}
+
+	// major*10^5 + minor*10^3 + patch*10^0
+	numericVersion := majorVersion*1e5 + minorVersion*1e3 + patchLevel
+	return numericVersion, nil
 }

aaparser/aaparser_test.go

@@ -5,9 +5,8 @@ import (
 )
 
 type versionExpected struct {
-	output string
-	major  int
-	minor  int
+	output  string
+	version int
 }
 
 func TestParseVersion(t *testing.T) {
@@ -18,8 +17,7 @@ Copyright (C) 1999-2008 Novell Inc.
 Copyright 2009-2012 Canonical Ltd.
 
 `,
-			major: 2,
-			minor: 10,
+			version: 210000,
 		},
 		{
 			output: `AppArmor parser version 2.8
@@ -27,8 +25,7 @@ Copyright (C) 1999-2008 Novell Inc.
 Copyright 2009-2012 Canonical Ltd.
 
 `,
-			major: 2,
-			minor: 8,
+			version: 208000,
 		},
 		{
 			output: `AppArmor parser version 2.20
@@ -36,8 +33,7 @@ Copyright (C) 1999-2008 Novell Inc.
 Copyright 2009-2012 Canonical Ltd.
 
 `,
-			major: 2,
-			minor: 20,
+			version: 220000,
 		},
 		{
 			output: `AppArmor parser version 2.05
@@ -45,21 +41,33 @@ Copyright (C) 1999-2008 Novell Inc.
 Copyright 2009-2012 Canonical Ltd.
 
 `,
-			major: 2,
-			minor: 5,
+			version: 205000,
+		},
+		{
+			output: `AppArmor parser version 2.9.95
+Copyright (C) 1999-2008 Novell Inc.
+Copyright 2009-2012 Canonical Ltd.
+
+`,
+			version: 209095,
+		},
+		{
+			output: `AppArmor parser version 3.14.159
+Copyright (C) 1999-2008 Novell Inc.
+Copyright 2009-2012 Canonical Ltd.
+
+`,
+			version: 314159,
 		},
 	}
 
 	for _, v := range versions {
-		major, minor, err := parseVersion(v.output)
+		version, err := parseVersion(v.output)
 		if err != nil {
 			t.Fatalf("expected error to be nil for %#v, got: %v", v, err)
 		}
-		if major != v.major {
-			t.Fatalf("expected major version to be %d, was %d, for: %#v\n", v.major, major, v)
-		}
-		if minor != v.minor {
-			t.Fatalf("expected minor version to be %d, was %d, for: %#v\n", v.minor, minor, v)
+		if version != v.version {
+			t.Fatalf("expected version to be %d, was %d, for: %#v\n", v.version, version, v)
 		}
 	}
 }