Rename group package and defaults to halls

2026-05-17 22:37:38 -04:00
parent 55528b8e62
commit a8ada950d5
26 changed files with 459 additions and 459 deletions
@@ -0,0 +1,783 @@
+package hall
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io/fs"
+	"log"
+	"os"
+	"path"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"git.stormux.org/storm/skald/token"
+)
+
+var ErrTagMismatch = errors.New("tag mismatch")
+var ErrDescriptionsNotWritable = &NotAuthorisedError{}
+var ErrUnknownPermission = errors.New("unknown permission")
+
+type Permissions struct {
+	// non-empty for a named permissions set
+	name string
+	// only used when unnamed
+	permissions []string
+}
+
+var permissionsMap = map[string][]string{
+	"op":      {"op", "present", "message", "caption", "token"},
+	"present": {"present", "message"},
+	"message": {"message"},
+	"observe": {},
+	"caption": {"caption"},
+	"admin":   {"admin"},
+}
+
+func NewPermissions(name string) (Permissions, error) {
+	_, ok := permissionsMap[name]
+	if !ok {
+		return Permissions{}, ErrUnknownPermission
+	}
+	return Permissions{
+		name: name,
+	}, nil
+}
+
+func (p Permissions) Permissions(desc *Description) []string {
+	if p.name == "" {
+		return p.permissions
+	}
+
+	perms := permissionsMap[p.name]
+
+	op := false
+	present := false
+	token := false
+	record := false
+	for _, p := range perms {
+		switch p {
+		case "op":
+			op = true
+		case "present":
+			present = true
+		case "token":
+			token = true
+		case "record":
+			record = true
+		}
+	}
+
+	if desc != nil && desc.AllowRecording {
+		if op && !record {
+			// copy the slice
+			perms = append([]string{"record"}, perms...)
+		}
+	}
+
+	if desc != nil && desc.UnrestrictedTokens {
+		if present && !token {
+			perms = append([]string{"token"}, perms...)
+		}
+	}
+
+	return perms
+}
+
+func (p Permissions) String() string {
+	if p.name != "" {
+		if p.permissions != nil {
+			return fmt.Sprintf("(ERROR=overconstrained %v)", p.name)
+		}
+		return p.name
+	}
+	v, err := json.Marshal(p)
+	if err != nil {
+		return fmt.Sprintf("(ERROR=%v)", err)
+	}
+	return string(v)
+}
+
+func (p *Permissions) UnmarshalJSON(b []byte) error {
+	var a []string
+	err := json.Unmarshal(b, &a)
+	if err == nil {
+		*p = Permissions{
+			permissions: a,
+		}
+		return nil
+	}
+	var s string
+	err = json.Unmarshal(b, &s)
+	if err == nil {
+		_, ok := permissionsMap[s]
+		if !ok {
+			return ErrUnknownPermission
+		}
+		*p = Permissions{
+			name: s,
+		}
+		return nil
+	}
+	return err
+}
+
+func (p Permissions) MarshalJSON() ([]byte, error) {
+	if p.name != "" {
+		return json.Marshal(p.name)
+	}
+	return json.Marshal(p.permissions)
+}
+
+type UserDescription struct {
+	Password    Password    `json:"password"`
+	Permissions Permissions `json:"permissions"`
+}
+
+// Custom MarshalJSON in order to omit empty fields
+func (u UserDescription) MarshalJSON() ([]byte, error) {
+	uu := make(map[string]any, 2)
+	if u.Password.Type != "" {
+		uu["password"] = &u.Password
+	}
+	if u.Permissions.name != "" || u.Permissions.permissions != nil {
+		uu["permissions"] = &u.Permissions
+	}
+	return json.Marshal(uu)
+}
+
+// Description represents a hall description together with some metadata
+// about the JSON file it was deserialised from.
+type Description struct {
+	// The file this was deserialised from.  This is not necessarily
+	// the name of the hall, for example in case of a subgroup.
+	FileName string `json:"-"`
+
+	// The modtime and size of the file.  These are used to detect
+	// when a file has changed on disk.
+	modTime  time.Time `json:"-"`
+	fileSize int64     `json:"-"`
+
+	// Whether this is an automatically generated subgroup
+	isSubgroup bool `json:"-"`
+
+	// The user-friendly hall name
+	DisplayName string `json:"displayName,omitempty"`
+
+	// A user-readable description of the hall.
+	Description string `json:"description,omitempty"`
+
+	// A user-readable contact, typically an e-mail address.
+	Contact string `json:"contact,omitempty"`
+
+	// A user-readable comment.  Ignored by the server.
+	Comment string `json:"comment,omitempty"`
+
+	// Whether to display the hall on the landing page.
+	Public bool `json:"public,omitempty"`
+
+	// A URL to redirect the hall to.  If this is not empty, most
+	// other fields are ignored.
+	Redirect string `json:"redirect,omitempty"`
+
+	// The maximum number of simultaneous clients.  Unlimited if 0.
+	MaxClients int `json:"max-clients,omitempty"`
+
+	// The time for which history entries are kept.
+	MaxHistoryAge int `json:"max-history-age,omitempty"`
+
+	// Time after which joining is no longer allowed
+	Expires *time.Time `json:"expires,omitempty"`
+
+	// Time before which joining is not allowed
+	NotBefore *time.Time `json:"not-before,omitempty"`
+
+	// Whether recording is allowed.
+	AllowRecording bool `json:"allow-recording,omitempty"`
+
+	// Whether creating tokens is allowed
+	UnrestrictedTokens bool `json:"unrestricted-tokens,omitempty"`
+
+	// Whether subgroups are created on the fly.
+	AutoSubgroups bool `json:"auto-subgroups,omitempty"`
+
+	// Whether to lock the hall when the last op logs out.
+	Autolock bool `json:"autolock,omitempty"`
+
+	// Whether to kick all users when the last op logs out.
+	Autokick bool `json:"autokick,omitempty"`
+
+	// Users allowed to login
+	Users map[string]UserDescription `json:"users,omitempty"`
+
+	// Credentials for user with arbitrary username
+	WildcardUser *UserDescription `json:"wildcard-user,omitempty"`
+
+	// The (public) keys used for token authentication.
+	AuthKeys []map[string]interface{} `json:"authKeys,omitempty"`
+
+	// The URL of the authentication server, if any.
+	AuthServer string `json:"authServer,omitempty"`
+
+	// The URL of the authentication portal, if any.
+	AuthPortal string `json:"authPortal,omitempty"`
+
+	// Codec preferences.  If empty, a suitable default is chosen in
+	// the APIFromNames function.
+	Codecs []string `json:"codecs,omitempty"`
+
+	// Obsolete fields
+	Op             []ClientPattern `json:"op,omitempty"`
+	Presenter      []ClientPattern `json:"presenter,omitempty"`
+	Other          []ClientPattern `json:"other,omitempty"`
+	AllowSubgroups bool            `json:"allow-subgroups,omitempty"`
+	AllowAnonymous bool            `json:"allow-anonymous,omitempty"`
+}
+
+const DefaultMaxHistoryAge = 4 * time.Hour
+
+func maxHistoryAge(desc *Description) time.Duration {
+	if desc.MaxHistoryAge != 0 {
+		return time.Duration(desc.MaxHistoryAge) * time.Second
+	}
+	return DefaultMaxHistoryAge
+}
+
+func getDescriptionFile[T any](name string, allowSubgroups bool, get func(string) (T, error)) (T, string, bool, error) {
+	isSubgroup := false
+	for name != "" {
+		fileName := filepath.Join(
+			Directory, path.Clean("/"+name)+".json",
+		)
+		r, err := get(fileName)
+		if !errors.Is(err, os.ErrNotExist) {
+			return r, fileName, isSubgroup, err
+		}
+		if !allowSubgroups {
+			break
+		}
+		isSubgroup = true
+		name, _ = path.Split(name)
+		name = strings.TrimRight(name, "/")
+	}
+	var zero T
+	return zero, "", false, os.ErrNotExist
+}
+
+// descriptionMatch returns true if the description hasn't changed between
+// d1 and d2
+func descriptionMatch(d1, d2 *Description) bool {
+	if d1.FileName != d2.FileName {
+		return false
+	}
+
+	if d1.fileSize != d2.fileSize || !d1.modTime.Equal(d2.modTime) {
+		return false
+	}
+	return true
+}
+
+// descriptionUnchanged returns true if a hall's description hasn't
+// changed since it was last read.
+func descriptionUnchanged(name string, desc *Description) bool {
+	fi, fileName, _, err := getDescriptionFile(name, true, os.Stat)
+	if err != nil || fileName != desc.FileName {
+		return false
+	}
+
+	if fi.Size() != desc.fileSize || !fi.ModTime().Equal(desc.modTime) {
+		return false
+	}
+	return true
+}
+
+// GetDescription gets a hall description, either from cache or from disk
+func GetDescription(name string) (*Description, error) {
+	g := Get(name)
+	if g != nil {
+		if descriptionUnchanged(name, g.description) {
+			return g.description, nil
+		}
+	}
+
+	return readDescription(name, true)
+}
+
+// GetSanitisedDescription returns the subset of the description that is
+// published on the web interface together with a suitable ETag.
+func GetSanitisedDescription(name string) (*Description, string, error) {
+	d, err := GetDescription(name)
+	if err != nil {
+		return nil, "", err
+	}
+	if d.isSubgroup {
+		return nil, "", os.ErrNotExist
+	}
+
+	desc := *d
+	desc.Users = nil
+	desc.WildcardUser = nil
+	desc.AuthKeys = nil
+	return &desc, makeETag(desc.fileSize, desc.modTime), nil
+}
+
+// GetDescriptionTag returns an ETag for a description.
+func GetDescriptionTag(name string) (string, error) {
+	fi, _, _, err := getDescriptionFile(name, false, os.Stat)
+	if err != nil {
+		return "", err
+	}
+	return makeETag(fi.Size(), fi.ModTime()), nil
+}
+
+func makeETag(fileSize int64, modTime time.Time) string {
+	return fmt.Sprintf("\"%v-%v\"", fileSize, modTime.UnixNano())
+}
+
+// DeleteDescription deletes a description (and therefore persistently
+// deletes a hall) but only if it matches a given ETag.
+func DeleteDescription(name, etag string) error {
+	halls.mu.Lock()
+	defer halls.mu.Unlock()
+
+	fi, fileName, _, err := getDescriptionFile(name, false, os.Stat)
+	if err != nil {
+		return err
+	}
+	if etag != makeETag(fi.Size(), fi.ModTime()) {
+		return ErrTagMismatch
+	}
+	return os.Remove(fileName)
+}
+
+// UpdateDescription overwrites a description if it matches a given ETag.
+// In order to create a new hall, pass an empty ETag.
+func UpdateDescription(name, etag string, desc *Description) error {
+	if desc.Users != nil || desc.WildcardUser != nil || desc.AuthKeys != nil {
+		return errors.New("description is not sanitised")
+	}
+
+	halls.mu.Lock()
+	defer halls.mu.Unlock()
+
+	oldetag := ""
+	var filename string
+	old, err := readDescription(name, false)
+	if err == nil {
+		oldetag = makeETag(old.fileSize, old.modTime)
+		filename = old.FileName
+	} else if errors.Is(err, os.ErrNotExist) {
+		old = nil
+		filename = filepath.Join(
+			Directory, path.Clean("/"+name)+".json",
+		)
+	} else {
+		return err
+	}
+
+	if oldetag != etag {
+		return ErrTagMismatch
+	}
+
+	newdesc := *desc
+	if old != nil {
+		newdesc.Users = old.Users
+		newdesc.WildcardUser = old.WildcardUser
+		newdesc.AuthKeys = old.AuthKeys
+	}
+
+	return rewriteDescriptionFile(filename, &newdesc)
+}
+
+func rewriteDescriptionFile(filename string, desc *Description) error {
+	conf, err := GetConfiguration()
+	if err != nil {
+		return err
+	}
+	if !conf.WritableGroups {
+		return ErrDescriptionsNotWritable
+	}
+
+	dir := filepath.Dir(filename)
+
+	err = os.MkdirAll(dir, 0700)
+	if err != nil {
+		return err
+	}
+
+	f, err := os.CreateTemp(dir, "*.temp")
+	if err != nil {
+		return err
+	}
+	temp := f.Name()
+
+	encoder := json.NewEncoder(f)
+	err = encoder.Encode(desc)
+	if err == nil {
+		err = f.Sync()
+	}
+	if err != nil {
+		f.Close()
+		os.Remove(temp)
+		return err
+	}
+	err = f.Close()
+	if err != nil {
+		os.Remove(temp)
+		return err
+	}
+
+	err = os.Rename(temp, filename)
+	if err != nil {
+		os.Remove(temp)
+		return err
+	}
+
+	return nil
+
+}
+
+// readDescription reads a hall's description from disk
+func readDescription(name string, allowSubgroups bool) (*Description, error) {
+	r, fileName, isSubgroup, err :=
+		getDescriptionFile(name, allowSubgroups, os.Open)
+	if err != nil {
+		return nil, err
+	}
+	defer r.Close()
+
+	var desc Description
+
+	fi, err := r.Stat()
+	if err != nil {
+		return nil, err
+	}
+
+	d := json.NewDecoder(r)
+	d.DisallowUnknownFields()
+	err = d.Decode(&desc)
+	if err != nil {
+		return nil, err
+	}
+	desc.FileName = fileName
+	desc.fileSize = fi.Size()
+	desc.modTime = fi.ModTime()
+
+	err = upgradeDescription(&desc)
+	if err != nil {
+		return nil, err
+	}
+
+	if isSubgroup {
+		if !desc.AutoSubgroups {
+			return nil, os.ErrNotExist
+		}
+		desc.isSubgroup = true
+		desc.Public = false
+		desc.Description = ""
+	}
+
+	return &desc, nil
+}
+
+func upgradeDescription(desc *Description) error {
+	if desc.AllowAnonymous {
+		log.Printf(
+			"%v: field allow-anonymous is obsolete, ignored",
+			desc.FileName,
+		)
+		desc.AllowAnonymous = false
+	}
+
+	if desc.AllowSubgroups {
+		desc.AutoSubgroups = true
+		desc.AllowSubgroups = false
+	}
+
+	upgradePassword := func(pw *Password) Password {
+		if pw == nil {
+			return Password{
+				Type: "wildcard",
+			}
+		}
+		return *pw
+	}
+
+	upgradeUser := func(u ClientPattern, p string) UserDescription {
+		return UserDescription{
+			Password: upgradePassword(u.Password),
+			Permissions: Permissions{
+				name: p,
+			},
+		}
+	}
+
+	upgradeUsers := func(ps []ClientPattern, p string) {
+		if desc.Users == nil {
+			desc.Users = make(map[string]UserDescription)
+		}
+		for _, u := range ps {
+			if u.Username == "" {
+				if desc.WildcardUser != nil {
+					log.Printf("%v: duplicate wildcard user",
+						desc.FileName)
+					continue
+				}
+				u := upgradeUser(u, p)
+				desc.WildcardUser = &u
+				continue
+			}
+			_, found := desc.Users[u.Username]
+			if found {
+				log.Printf("%v: duplicate user %v, ignored",
+					desc.FileName, u.Username)
+				continue
+			}
+			desc.Users[u.Username] = upgradeUser(u, p)
+		}
+	}
+
+	if desc.Op != nil {
+		upgradeUsers(desc.Op, "op")
+		desc.Op = nil
+	}
+	if desc.Presenter != nil {
+		upgradeUsers(desc.Presenter, "present")
+		desc.Presenter = nil
+	}
+	if desc.Other != nil {
+		upgradeUsers(desc.Other, "message")
+		desc.Other = nil
+	}
+
+	return nil
+}
+
+func GetDescriptionNames() ([]string, error) {
+	var names []string
+	err := filepath.WalkDir(
+		Directory,
+		func(path string, d fs.DirEntry, err error) error {
+			if err != nil {
+				return nil
+			}
+			base := filepath.Base(path)
+			if d.IsDir() {
+				if base[0] == '.' {
+					return fs.SkipDir
+				}
+				return nil
+			}
+			if base[0] == '.' {
+				return nil
+			}
+			p, err := filepath.Rel(Directory, path)
+			if err != nil || !strings.HasSuffix(p, ".json") {
+				return nil
+			}
+			names = append(names, strings.TrimSuffix(
+				p, ".json",
+			))
+			return nil
+		},
+	)
+	return names, err
+}
+
+func SetKeys(hall string, keys []map[string]any) error {
+	if keys != nil {
+		_, err := token.ParseKeys(keys, "", "")
+		if err != nil {
+			return err
+		}
+	}
+
+	halls.mu.Lock()
+	defer halls.mu.Unlock()
+
+	desc, err := readDescription(hall, false)
+	if err != nil {
+		return err
+	}
+	desc.AuthKeys = keys
+	return rewriteDescriptionFile(desc.FileName, desc)
+}
+
+func GetUsers(hall string) ([]string, string, error) {
+	desc, err := GetDescription(hall)
+	if err != nil {
+		return nil, "", err
+	}
+
+	users := make([]string, 0, len(desc.Users))
+	for u := range desc.Users {
+		users = append(users, u)
+	}
+
+	return users, makeETag(desc.fileSize, desc.modTime), nil
+}
+
+func GetSanitisedUser(hall, username string, wildcard bool) (UserDescription, string, error) {
+	if wildcard && username != "" {
+		return UserDescription{}, "",
+			errors.New("wildcard with username")
+	}
+
+	desc, err := GetDescription(hall)
+	if err != nil {
+		return UserDescription{}, "", err
+	}
+
+	var u UserDescription
+	if wildcard {
+		if desc.WildcardUser == nil {
+			return UserDescription{}, "", os.ErrNotExist
+		}
+		u = *desc.WildcardUser
+	} else {
+		if desc.Users == nil {
+			return UserDescription{}, "", os.ErrNotExist
+		}
+
+		ok := false
+		u, ok = desc.Users[username]
+		if !ok {
+			return UserDescription{}, "", os.ErrNotExist
+		}
+	}
+
+	u.Password = Password{}
+	return u, makeETag(desc.fileSize, desc.modTime), nil
+}
+
+func GetUserTag(hall, username string, wildcard bool) (string, error) {
+	_, etag, err := GetSanitisedUser(hall, username, wildcard)
+	return etag, err
+}
+
+func DeleteUser(hall, username string, wildcard bool, etag string) error {
+	if wildcard && username != "" {
+		return errors.New("wildcard with username")
+	}
+
+	halls.mu.Lock()
+	defer halls.mu.Unlock()
+
+	desc, err := readDescription(hall, false)
+	if err != nil {
+		return err
+	}
+
+	if wildcard {
+		if desc.WildcardUser == nil {
+			return os.ErrNotExist
+		}
+	} else {
+		if desc.Users == nil {
+			return os.ErrNotExist
+		}
+		_, ok := desc.Users[username]
+		if !ok {
+			return os.ErrNotExist
+		}
+	}
+
+	oldetag := makeETag(desc.fileSize, desc.modTime)
+	if oldetag != etag {
+		return ErrTagMismatch
+	}
+
+	if wildcard {
+		desc.WildcardUser = nil
+	} else {
+		delete(desc.Users, username)
+	}
+
+	return rewriteDescriptionFile(desc.FileName, desc)
+}
+
+func UpdateUser(hall, username string, wildcard bool, etag string, user *UserDescription) error {
+	if wildcard && username != "" {
+		return errors.New("wildcard with username")
+	}
+	if user.Password.Type != "" || user.Password.Key != nil {
+		return errors.New("user description is not sanitised")
+	}
+
+	halls.mu.Lock()
+	defer halls.mu.Unlock()
+
+	desc, err := readDescription(hall, false)
+	if err != nil {
+		return err
+	}
+
+	var old UserDescription
+	var ok bool
+	if wildcard {
+		if desc.WildcardUser != nil {
+			ok = true
+			old = *desc.WildcardUser
+		}
+	} else {
+		if desc.Users == nil {
+			desc.Users = make(map[string]UserDescription)
+		}
+		old, ok = desc.Users[username]
+	}
+
+	var oldetag string
+	if ok {
+		oldetag = makeETag(desc.fileSize, desc.modTime)
+	} else {
+		oldetag = ""
+	}
+
+	if oldetag != etag {
+		return ErrTagMismatch
+	}
+
+	newuser := *user
+	newuser.Password = old.Password
+
+	if wildcard {
+		desc.WildcardUser = &newuser
+	} else {
+		desc.Users[username] = newuser
+	}
+	return rewriteDescriptionFile(desc.FileName, desc)
+}
+
+func SetUserPassword(hall, username string, wildcard bool, pw Password) error {
+	if wildcard && username != "" {
+		return errors.New("wildcard with username")
+	}
+
+	halls.mu.Lock()
+	defer halls.mu.Unlock()
+
+	desc, err := readDescription(hall, false)
+	if err != nil {
+		return err
+	}
+
+	if wildcard {
+		if desc.WildcardUser == nil {
+			return os.ErrNotExist
+		}
+		desc.WildcardUser.Password = pw
+	} else {
+		if desc.Users == nil {
+			return os.ErrNotExist
+		}
+		user, ok := desc.Users[username]
+		if !ok {
+			return os.ErrNotExist
+		}
+
+		user.Password = pw
+		desc.Users[username] = user
+	}
+	return rewriteDescriptionFile(desc.FileName, desc)
+}