round 1 of follow-up for metadata

default.yaml

@@ -724,6 +724,7 @@ oper-classes:
             - "history"      # modify or delete history messages
             - "defcon"       # use the DEFCON command (restrict server capabilities)
             - "massmessage"  # message all users on the server
+            - "metadata"     # modify arbitrary metadata on channels and users
 
 # ircd operators
 opers:
@@ -1087,15 +1088,14 @@ history:
 # e.g., ERGO__SERVER__MAX_SENDQ=128k. see the manual for more details.
 allow-environment-overrides: true
 
-# experimental IRC metadata support for setting key/value data on channels and nicknames.
+# metadata support for setting key/value data on channels and nicknames.
 metadata:
     # can clients store metadata?
     enabled: true
-    # how many keys can a client subscribe to? 
-    # set to 0 to disable subscriptions or -1 to allow unlimited subscriptions.
+    # how many keys can a client subscribe to?
     max-subs: 100
-    # how many keys can a user store about themselves? set to -1 to allow unlimited keys.
-    max-keys: 1000
+    # how many keys can be stored per entity?
+    max-keys: 100
 
 # experimental support for mobile push notifications
 # see the manual for potential security, privacy, and performance implications.

irc/channel.go

@@ -7,6 +7,7 @@ package irc
 
 import (
 	"fmt"
+	"iter"
 	"maps"
 	"strconv"
 	"strings"
@@ -1676,6 +1677,20 @@ func (channel *Channel) auditoriumFriends(client *Client) (friends []*Client) {
 	return
 }
 
+func (channel *Channel) sessionsWithCaps(capabs ...caps.Capability) iter.Seq[*Session] {
+	return func(yield func(*Session) bool) {
+		for _, member := range channel.Members() {
+			for _, sess := range member.Sessions() {
+				if sess.capabilities.HasAll(capabs...) {
+					if !yield(sess) {
+						return
+					}
+				}
+			}
+		}
+	}
+}
+
 // returns whether the client is visible to unprivileged users in the channel
 // (i.e., respecting auditorium mode). note that this assumes that the client
 // is a member; if the client is not, it may return true anyway

irc/channelmanager.go

@@ -206,6 +206,10 @@ func (cm *ChannelManager) Cleanup(channel *Channel) {
 }
 
 func (cm *ChannelManager) SetRegistered(channelName string, account string) (err error) {
+	if account == "" {
+		return errAuthRequired // this is already enforced by ChanServ, but do a final check
+	}
+
 	if cm.server.Defcon() <= 4 {
 		return errFeatureDisabled
 	}

irc/config.go

@@ -728,7 +728,7 @@ type Config struct {
 		Enabled       bool
 		MaxSubs       int `yaml:"max-subs"`
 		MaxKeys       int `yaml:"max-keys"`
-		MaxValueBytes int `yaml:"max-value-length"` // todo: currently unenforced!!
+		MaxValueBytes int `yaml:"max-value-length"`
 	}
 
 	WebPush struct {
@@ -1649,19 +1649,20 @@ func LoadConfig(filename string) (config *Config, err error) {
 		config.Server.supportedCaps.Disable(caps.Metadata)
 	} else {
 		var metadataValues []string
-		if config.Metadata.MaxSubs >= 0 {
-			metadataValues = append(metadataValues, fmt.Sprintf("max-subs=%d", config.Metadata.MaxSubs))
+		// these are required for normal operation, so set sane defaults:
+		if config.Metadata.MaxSubs == 0 {
+			config.Metadata.MaxSubs = 10
 		}
-		if config.Metadata.MaxKeys > 0 {
-			metadataValues = append(metadataValues, fmt.Sprintf("max-keys=%d", config.Metadata.MaxKeys))
+		metadataValues = append(metadataValues, fmt.Sprintf("max-subs=%d", config.Metadata.MaxSubs))
+		if config.Metadata.MaxKeys == 0 {
+			config.Metadata.MaxKeys = 10
 		}
+		metadataValues = append(metadataValues, fmt.Sprintf("max-keys=%d", config.Metadata.MaxKeys))
+		// this is not required since we enforce a hardcoded upper bound on key+value
 		if config.Metadata.MaxValueBytes > 0 {
 			metadataValues = append(metadataValues, fmt.Sprintf("max-value-bytes=%d", config.Metadata.MaxValueBytes))
 		}
-		if len(metadataValues) != 0 {
-			config.Server.capValues[caps.Metadata] = strings.Join(metadataValues, ",")
-		}
-
+		config.Server.capValues[caps.Metadata] = strings.Join(metadataValues, ",")
 	}
 
 	err = config.processExtjwt()

irc/errors.go

@@ -33,6 +33,7 @@ var (
 	errAccountVerificationInvalidCode = errors.New("Invalid account verification code")
 	errAccountUpdateFailed            = errors.New(`Error while updating your account information`)
 	errAccountMustHoldNick            = errors.New(`You must hold that nickname in order to register it`)
+	errAuthRequired                   = errors.New("You must be logged into an account to do this")
 	errAuthzidAuthcidMismatch         = errors.New(`authcid and authzid must be the same`)
 	errCertfpAlreadyExists            = errors.New(`An account already exists for your certificate fingerprint`)
 	errChannelNotOwnedByAccount       = errors.New("Channel not owned by the specified account")

irc/getters.go

@@ -894,7 +894,7 @@ func (channel *Channel) GetMetadata(key string) (string, bool) {
 	return val, ok
 }
 
-func (channel *Channel) SetMetadata(key string, value string) {
+func (channel *Channel) SetMetadata(key string, value string, limit int) (updated bool, err error) {
 	defer channel.MarkDirty(IncludeAllAttrs)
 
 	channel.stateMutex.Lock()
@@ -904,7 +904,15 @@ func (channel *Channel) SetMetadata(key string, value string) {
 		channel.metadata = make(map[string]string)
 	}
 
-	channel.metadata[key] = value
+	existing, ok := channel.metadata[key]
+	if !ok && len(channel.metadata) >= limit {
+		return false, errLimitExceeded
+	}
+	updated = !ok || value != existing
+	if updated {
+		channel.metadata[key] = value
+	}
+	return updated, nil
 }
 
 func (channel *Channel) ListMetadata() map[string]string {
@@ -914,13 +922,17 @@ func (channel *Channel) ListMetadata() map[string]string {
 	return maps.Clone(channel.metadata)
 }
 
-func (channel *Channel) DeleteMetadata(key string) {
+func (channel *Channel) DeleteMetadata(key string) (updated bool) {
 	defer channel.MarkDirty(IncludeAllAttrs)
 
 	channel.stateMutex.Lock()
 	defer channel.stateMutex.Unlock()
 
-	delete(channel.metadata, key)
+	_, updated = channel.metadata[key]
+	if updated {
+		delete(channel.metadata, key)
+	}
+	return updated
 }
 
 func (channel *Channel) ClearMetadata() map[string]string {
@@ -949,15 +961,23 @@ func (client *Client) GetMetadata(key string) (string, bool) {
 	return val, ok
 }
 
-func (client *Client) SetMetadata(key string, value string) {
+func (client *Client) SetMetadata(key string, value string, limit int) (updated bool, err error) {
 	client.stateMutex.Lock()
 	defer client.stateMutex.Unlock()
 
 	if client.metadata == nil {
 		client.metadata = make(map[string]string)
 	}
 
-	client.metadata[key] = value
+	existing, ok := client.metadata[key]
+	if !ok && len(client.metadata) >= limit {
+		return false, errLimitExceeded
+	}
+	updated = !ok || value != existing
+	if updated {
+		client.metadata[key] = value
+	}
+	return updated, nil
 }
 
 func (client *Client) ListMetadata() map[string]string {
@@ -967,11 +987,15 @@ func (client *Client) ListMetadata() map[string]string {
 	return maps.Clone(client.metadata)
 }
 
-func (client *Client) DeleteMetadata(key string) {
+func (client *Client) DeleteMetadata(key string) (updated bool) {
 	client.stateMutex.Lock()
 	defer client.stateMutex.Unlock()
 
-	delete(client.metadata, key)
+	_, updated = client.metadata[key]
+	if updated {
+		delete(client.metadata, key)
+	}
+	return updated
 }
 
 func (client *Client) ClearMetadata() map[string]string {