feat: implement multi-root virtual filesystem

chfs-ng/cmd/chfs/main.go

@@ -53,17 +53,21 @@ func main() {
 	}
 
 	root := cfg.Path[0]
-	if len(cfg.Path) > 1 {
-		log.Printf("warning: %d shared roots configured; v1 compatibility currently serves the first root %q", len(cfg.Path), root)
-	}
-	if err := os.MkdirAll(root, 0755); err != nil {
-		log.Fatal(err)
+	for _, p := range cfg.Path {
+		if err := os.MkdirAll(p, 0755); err != nil {
+			log.Fatal(err)
+		}
 	}
 	mgr, err := auth.ParseRules(cfg.Rules)
 	if err != nil {
 		log.Fatal(err)
 	}
-	srv := &api.Server{Store: storage.Local{Root: root}, Auth: mgr, Sessions: map[string]*auth.Account{}, WebDAVRoot: root, Allow: cfg.Allow}
+	multi := storage.NewMulti(cfg.Path)
+	store := storage.Storage(multi)
+	if len(cfg.Path) == 1 {
+		store = storage.Local{Root: root}
+	}
+	srv := &api.Server{Store: store, Auth: mgr, Sessions: map[string]*auth.Account{}, WebDAVRoot: root, Allow: cfg.Allow, MultiRoot: len(cfg.Path) > 1}
 	addr := ":" + itoa(cfg.Port)
 	log.Printf("chfs-ng listening on %s root=%s", addr, filepath.Clean(root))
 	if cfg.SSLCert != "" && cfg.SSLKey != "" {

chfs-ng/internal/api/server.go

@@ -24,6 +24,7 @@ type Server struct {
 	Sessions   map[string]*auth.Account
 	WebDAVRoot string
 	Allow      string
+	MultiRoot  bool
 }
 type fileInfo struct {
 	Name      string `json:"name"`
@@ -74,13 +75,13 @@ func qpath(r *http.Request) string {
 }
 func permString(p auth.PermMask) string {
 	if p.HasDelete() {
-		return "d"
+		return "RWD"
 	}
 	if p.HasWrite() {
-		return "w"
+		return "RW"
 	}
 	if p.HasRead() {
-		return "r"
+		return "R"
 	}
 	return ""
 }
@@ -106,9 +107,10 @@ func (s *Server) files(w http.ResponseWriter, r *http.Request) {
 				sub = len(xs) > 0
 			}
 		}
-		out = append(out, fileInfo{Name: fi.Name(), Path: fp, Size: fi.Size(), Modified: fi.ModTime().Format(time.RFC3339), Dir: fi.IsDir(), Mask: permString(a.MaskFor(fp)), HasSubDir: sub})
+		out = append(out, fileInfo{Name: fi.Name(), Path: fp, Size: fi.Size(), Modified: fi.ModTime().Format(time.RFC3339), Dir: fi.IsDir(), Mask: permString(a.MaskFor(fp)), GuestMask: permString(s.Auth.Guest.MaskFor(fp)), HasSubDir: sub})
 	}
-	writeJSON(w, map[string]any{"files": out, "currentMask": permString(m), "virtualRoot": false})
+	virtual := p == "" && s.MultiRoot
+	writeJSON(w, map[string]any{"files": out, "currentMask": permString(m), "virtualRoot": virtual})
 }
 func (s *Server) newdir(w http.ResponseWriter, r *http.Request) {
 	_ = r.ParseMultipartForm(16 << 20)

chfs-ng/internal/storage/multipath.go

@@ -0,0 +1,132 @@
+package storage
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+)
+
+type Multi struct {
+	Roots []Local
+	Names []string
+}
+
+func NewMulti(paths []string) Multi {
+	m := Multi{}
+	for _, p := range paths {
+		if strings.TrimSpace(p) == "" {
+			continue
+		}
+		abs, _ := filepath.Abs(p)
+		name := filepath.Base(filepath.Clean(abs))
+		if name == "." || name == string(filepath.Separator) || name == "" {
+			name = "root"
+		}
+		duplicate := false
+		for _, existing := range m.Names {
+			if existing == name {
+				duplicate = true
+				break
+			}
+		}
+		if duplicate {
+			continue
+		}
+		m.Roots = append(m.Roots, Local{Root: abs})
+		m.Names = append(m.Names, name)
+	}
+	return m
+}
+
+func (m Multi) isVirtualRoot(p string) bool { return strings.Trim(p, "/") == "" }
+
+func (m Multi) find(p string) (Local, string, bool) {
+	p = strings.Trim(strings.ReplaceAll(p, "\\", "/"), "/")
+	if p == "" {
+		return Local{}, "", false
+	}
+	parts := strings.SplitN(p, "/", 2)
+	for i, n := range m.Names {
+		if parts[0] != n {
+			continue
+		}
+		rel := ""
+		if len(parts) == 2 {
+			rel = parts[1]
+		}
+		return m.Roots[i], rel, true
+	}
+	return Local{}, "", false
+}
+
+func (m Multi) Stat(p string) (os.FileInfo, error) {
+	if m.isVirtualRoot(p) {
+		return virtualDirInfo{name: "."}, nil
+	}
+	r, rel, ok := m.find(p)
+	if !ok {
+		return nil, os.ErrNotExist
+	}
+	return r.Stat(rel)
+}
+func (m Multi) Open(p string) (*os.File, error) {
+	r, rel, ok := m.find(p)
+	if !ok {
+		return nil, os.ErrNotExist
+	}
+	return r.Open(rel)
+}
+func (m Multi) Create(p string) (*os.File, error) {
+	r, rel, ok := m.find(p)
+	if !ok {
+		return nil, os.ErrNotExist
+	}
+	return r.Create(rel)
+}
+func (m Multi) Remove(p string) error {
+	r, rel, ok := m.find(p)
+	if !ok {
+		return os.ErrNotExist
+	}
+	return r.Remove(rel)
+}
+func (m Multi) Rename(a, b string) error {
+	ra, aa, oka := m.find(a)
+	rb, bb, okb := m.find(b)
+	if !oka || !okb || ra.Root != rb.Root {
+		return os.ErrInvalid
+	}
+	return ra.Rename(aa, bb)
+}
+func (m Multi) MkdirAll(p string) error {
+	r, rel, ok := m.find(p)
+	if !ok {
+		return os.ErrNotExist
+	}
+	return r.MkdirAll(rel)
+}
+func (m Multi) List(p string) ([]os.FileInfo, error) {
+	p = strings.Trim(strings.ReplaceAll(p, "\\", "/"), "/")
+	if p == "" {
+		out := make([]os.FileInfo, 0, len(m.Names))
+		for _, n := range m.Names {
+			out = append(out, virtualDirInfo{name: n})
+		}
+		return out, nil
+	}
+	r, rel, ok := m.find(p)
+	if !ok {
+		return nil, os.ErrNotExist
+	}
+	return r.List(rel)
+}
+
+type virtualDirInfo struct{ name string }
+
+func (v virtualDirInfo) Name() string           { return v.name }
+func (v virtualDirInfo) Size() int64            { return 0 }
+func (v virtualDirInfo) Mode() os.FileMode      { return os.ModeDir | 0555 }
+func (v virtualDirInfo) ModTime() (t time.Time) { return time.Time{} }
+func (v virtualDirInfo) IsDir() bool            { return true }
+func (v virtualDirInfo) Sys() any               { return nil }