Remove restrictions from files that are included by pacman.conf

Author: pierres

.golangci.yaml

@@ -41,6 +41,7 @@ linters:
     gosec:
       excludes:
         - G104
+        - G304
 formatters:
   enable:
     - gofumpt

internal/pacman/parser.go

@@ -25,39 +25,24 @@ type Pacman struct {
 }
 
 type parser struct {
-	baseDir          *os.Root
 	includeFileCache map[string][]string
 }
 
 func Parse(pacmanConfPath string) (*Pacman, error) {
-	baseDir, err := os.OpenRoot(filepath.Dir(pacmanConfPath))
-	if err != nil {
-		return nil, err
-	}
-
-	conf, err := newParser(baseDir).parseConfigFile(pacmanConfPath, defaultDBPath)
+	conf, err := newParser().parseConfigFile(pacmanConfPath, defaultDBPath)
 	if err != nil {
 		return nil, err
 	}
 
 	return &Pacman{config: conf}, nil
 }
 
-func newParser(baseDir *os.Root) *parser {
+func newParser() *parser {
 	return &parser{
-		baseDir:          baseDir,
 		includeFileCache: make(map[string][]string),
 	}
 }
 
-func (parser *parser) openFile(name string) (*os.File, error) {
-	fileName, ok := strings.CutPrefix(name, parser.baseDir.Name()+"/")
-	if !ok {
-		return nil, fmt.Errorf("filename %s is not relative to %s", name, parser.baseDir.Name())
-	}
-	return parser.baseDir.Open(fileName)
-}
-
 func (parser *parser) parseConfigFile(configPath string, defaultDBPath string) (*config, error) {
 	lines, err := parser.readConfigFile(configPath, 0)
 	if err != nil {
@@ -84,7 +69,7 @@ func (parser *parser) readConfigFile(fileName string, depth int) ([]string, erro
 	if depth >= configMaxRecursion {
 		return nil, fmt.Errorf("reached maximum Include depth of %d", depth)
 	}
-	readFile, err := parser.openFile(fileName)
+	readFile, err := os.Open(fileName)
 	if err != nil {
 		return nil, err
 	}

tests/unit/internal/pacman/pacman_test.go

@@ -185,6 +185,100 @@ func TestPacmanConfEmptySections(t *testing.T) {
 	}
 }
 
+func TestPacmanConfWithRelativePath(t *testing.T) {
+	tempDir := t.TempDir()
+	currentDir, err := os.Getwd()
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		if err := os.Chdir(currentDir); err != nil {
+			t.Fatal(err)
+		}
+	}()
+
+	if err := os.Chdir(tempDir); err != nil {
+		t.Fatal(err)
+	}
+
+	if err := os.WriteFile("pacman.conf", fmt.Appendf(nil, "[core]\nServer=%s\n", MIRROR), 0o600); err != nil {
+		t.Fatalf("Failed to create pacman.conf: %v", err)
+	}
+
+	p, err := pacman.Parse("pacman.conf")
+	if err != nil {
+		t.Fatal(err)
+	}
+	out, err := p.GetServer()
+	if err != nil {
+		t.Fatal(err, out)
+	}
+	if out != SERVER {
+		t.Error(out)
+	}
+}
+
+func TestPacmanConfWithIncludesInSubdirectory(t *testing.T) {
+	tempDir := t.TempDir()
+	pacmanConfFile := filepath.Join(tempDir, "pacman.conf")
+	pacmanDDir := filepath.Join(tempDir, "pacman.d")
+
+	if err := os.Mkdir(pacmanDDir, 0o755); err != nil {
+		t.Fatalf("Failed to create pacman.d directory: %v", err)
+	}
+
+	mirrorlistFile := filepath.Join(pacmanDDir, "mirrorlist.local")
+	if err := os.WriteFile(mirrorlistFile, fmt.Appendf(nil, "Server=%s\n", MIRROR), 0o600); err != nil {
+		t.Fatalf("Failed to create mirrorlist: %v", err)
+	}
+
+	if err := os.WriteFile(pacmanConfFile, fmt.Appendf(nil, "[core]\nInclude=%s\n", mirrorlistFile), 0o600); err != nil {
+		t.Fatalf("Failed to create pacman.conf: %v", err)
+	}
+
+	p, err := pacman.Parse(pacmanConfFile)
+	if err != nil {
+		t.Fatal(err)
+	}
+	out, err := p.GetServer()
+	if err != nil {
+		t.Fatal(err, out)
+	}
+	if out != SERVER {
+		t.Error(out)
+	}
+}
+
+func TestPacmanConfSymlink(t *testing.T) {
+	tempDir := t.TempDir()
+	realConfigDir := filepath.Join(tempDir, "real-location")
+	if err := os.Mkdir(realConfigDir, 0o755); err != nil {
+		t.Fatalf("Failed to create real config directory: %v", err)
+	}
+
+	realConfigFile := filepath.Join(realConfigDir, "pacman.conf")
+	if err := os.WriteFile(realConfigFile, fmt.Appendf(nil, "[core]\nServer=%s\n", MIRROR), 0o600); err != nil {
+		t.Fatalf("Failed to create real pacman.conf: %v", err)
+	}
+
+	symlinkFile := filepath.Join(tempDir, "pacman.conf")
+	if err := os.Symlink(realConfigFile, symlinkFile); err != nil {
+		t.Fatalf("Failed to create symlink: %v", err)
+	}
+
+	p, err := pacman.Parse(symlinkFile)
+	if err != nil {
+		t.Fatal(err)
+	}
+	out, err := p.GetServer()
+	if err != nil {
+		t.Fatal(err, out)
+	}
+	if out != SERVER {
+		t.Error(out)
+	}
+}
+
 func TestNormalizeMirrorUrl(t *testing.T) {
 	tests := []struct {
 		input    string