README.md

@@ -2324,6 +2324,15 @@ IRC_LISTEN_ADDR=
   operator status (`@`).
 - **Channel modes**: `+m` (moderated), `+t` (topic lock), `+o` (operator),
   `+v` (voice)
+- **User modes**: `+o` (operator, set only via `OPER`), `+w` (receives
+  `WALLOPS`). `MODE` for any nick other than your own is rejected with
+  `ERR_USERSDONTMATCH` (502), for both queries and changes. Nick comparison
+  is case-insensitive.
+- **KILL**: an operator's `KILL` broadcasts the victim's `QUIT` to its channel
+  peers, deletes its session, and then sends the victim a `KILL` and
+  `ERROR :Closing Link` before closing its socket. This applies to victims on
+  the IRC listener regardless of whether the `KILL` arrived over IRC or the
+  HTTP API.
 
 ### Bridge to HTTP API
 

internal/db/queries.go

@@ -7,6 +7,7 @@ import (
 	"database/sql"
 	"encoding/hex"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"strconv"
 	"strings"
@@ -2509,7 +2510,9 @@ type UserhostInfo struct {
 }
 
 // GetUserhostInfo returns USERHOST info for the given
-// nicks. Only nicks that exist are returned.
+// nicks. Nicks with no session are omitted from the
+// result; any other database failure is returned, because
+// an unreadable row is not the same as an absent one.
 func (database *Database) GetUserhostInfo(
 	ctx context.Context,
 	nicks []string,
@@ -2534,7 +2537,13 @@ func (database *Database) GetUserhostInfo(
 			&info.IsOper, &info.AwayMessage,
 		)
 		if err != nil {
-			continue // nick not found, skip
+			if errors.Is(err, sql.ErrNoRows) {
+				continue // nick not online
+			}
+
+			return nil, fmt.Errorf(
+				"userhost lookup %q: %w", nick, err,
+			)
 		}
 
 		results = append(results, info)

internal/handlers/api_test.go

@@ -214,6 +214,7 @@ func newTestHandlers(
 		Config:   cfg,
 		Database: database,
 		Broker:   brk,
+		Globals:  globs,
 	})
 
 	hdlr, err := handlers.New(lifecycle, handlers.Params{ //nolint:exhaustruct

internal/handlers/utility.go

@@ -184,7 +184,7 @@ func (hdlr *Handlers) handleVersion(
 ) {
 	ctx := request.Context()
 	srvName := hdlr.serverName()
-	version := hdlr.serverVersion()
+	version := hdlr.svc.ServerVersion()
 
 	// 351 RPL_VERSION
 	hdlr.enqueueNumeric(
@@ -250,18 +250,8 @@ func (hdlr *Handlers) handleInfo(
 	nick string,
 ) {
 	ctx := request.Context()
-	version := hdlr.serverVersion()
 
-	infoLines := []string{
-		"neoirc — IRC semantics over HTTP",
-		"Version: " + version,
-		"Written in Go",
-		"Started: " +
-			hdlr.params.Globals.StartTime.
-				Format(time.RFC1123),
-	}
-
-	for _, line := range infoLines {
+	for _, line := range hdlr.svc.InfoLines() {
 		// 371 RPL_INFO
 		hdlr.enqueueNumeric(
 			ctx, clientID, irc.RplInfo, nick, nil,
@@ -379,9 +369,11 @@ func (hdlr *Handlers) handleKill(
 
 	quitReason := "Killed (" + nick + " (" + reason + "))"
 
-	hdlr.svc.BroadcastQuit(
-		request.Context(), targetSID,
-		targetNick, quitReason,
+	// KillSession broadcasts the QUIT, deletes the session
+	// and disconnects the victim's wire connection if it
+	// holds one.
+	hdlr.svc.KillSession(
+		ctx, targetSID, targetNick, quitReason,
 	)
 
 	hdlr.respondJSON(writer, request,
@@ -484,12 +476,12 @@ func (hdlr *Handlers) handleUserMode(
 ) {
 	ctx := request.Context()
 
-	lines := bodyLines()
-
-	// Mode change requested.
-	if len(lines) > 0 {
-		// Users can only change their own modes.
-		if target != nick && target != "" {
+	// Users can only query or change their own modes. The
+	// check is above the query/change split so that both
+	// forms are rejected, and uses EqualFold because IRC
+	// nicks are case-insensitive — matching the wire path
+	// in ircserver.handleUserMode.
+	if target != "" && !strings.EqualFold(target, nick) {
 		hdlr.respondIRCError(
 			writer, request, clientID, sessionID,
 			irc.ErrUsersDoNotMatch, nick, nil,
@@ -499,8 +491,56 @@ func (hdlr *Handlers) handleUserMode(
 		return
 	}
 
+	lines := bodyLines()
+
+	// Mode change requested.
+	if len(lines) > 0 {
+		hdlr.changeUserMode(
+			writer, request,
+			sessionID, clientID, nick, lines[0],
+		)
+
+		return
+	}
+
+	// Mode query — delegate to shared service.
+	modeStr, err := hdlr.svc.QueryUserMode(ctx, sessionID)
+	if err != nil {
+		hdlr.log.Error(
+			"query user mode failed", "error", err,
+		)
+		hdlr.respondError(
+			writer, request,
+			"internal error",
+			http.StatusInternalServerError,
+		)
+
+		return
+	}
+
+	hdlr.enqueueNumeric(
+		ctx, clientID, irc.RplUmodeIs, nick, nil,
+		modeStr,
+	)
+	hdlr.broker.Notify(sessionID)
+	hdlr.respondJSON(writer, request,
+		map[string]string{"status": "ok"},
+		http.StatusOK)
+}
+
+// changeUserMode applies a mode string to the caller's own
+// session. The caller has already verified that the target
+// nick is the caller's own.
+func (hdlr *Handlers) changeUserMode(
+	writer http.ResponseWriter,
+	request *http.Request,
+	sessionID, clientID int64,
+	nick, modeStr string,
+) {
+	ctx := request.Context()
+
 	newModes, err := hdlr.svc.ApplyUserMode(
-			ctx, sessionID, lines[0],
+		ctx, sessionID, modeStr,
 	)
 	if err != nil {
 		var ircErr *service.IRCError
@@ -533,19 +573,4 @@ func (hdlr *Handlers) handleUserMode(
 	hdlr.respondJSON(writer, request,
 		map[string]string{"status": "ok"},
 		http.StatusOK)
-
-		return
-	}
-
-	// Mode query — delegate to shared service.
-	modeStr := hdlr.svc.QueryUserMode(ctx, sessionID)
-
-	hdlr.enqueueNumeric(
-		ctx, clientID, irc.RplUmodeIs, nick, nil,
-		modeStr,
-	)
-	hdlr.broker.Notify(sessionID)
-	hdlr.respondJSON(writer, request,
-		map[string]string{"status": "ok"},
-		http.StatusOK)
 }

internal/handlers/utility_test.go

@@ -959,6 +959,95 @@ func TestUserModeCannotChangeOtherUser(t *testing.T) {
 	}
 }
 
+// TestUserModeCannotQueryOtherUser covers the MODE query
+// form (no body). Without a body there is no mode change
+// to reject, so a missing target check here silently
+// answers with the *requester's* own modes.
+func TestUserModeCannotQueryOtherUser(t *testing.T) {
+	tserver := newTestServer(t)
+
+	// Give the other user a mode the querier does not have,
+	// so leaking their modes would be visible.
+	otherToken := tserver.createSession("target")
+	_, otherLast := tserver.pollMessages(otherToken, 0)
+
+	tserver.sendCommand(otherToken, map[string]any{
+		commandKey: "MODE",
+		toKey:      "target",
+		bodyKey:    []string{"+w"},
+	})
+	tserver.pollMessages(otherToken, otherLast)
+
+	token := tserver.createSession("querier")
+	_, lastID := tserver.pollMessages(token, 0)
+
+	// Query another user's modes — no body.
+	tserver.sendCommand(token, map[string]any{
+		commandKey: "MODE",
+		toKey:      "target",
+	})
+
+	msgs, _ := tserver.pollMessages(token, lastID)
+
+	// Expect 502 ERR_USERSDONTMATCH.
+	if !findNumeric(msgs, "502") {
+		t.Fatalf(
+			"expected ERR_USERSDONTMATCH (502), got %v",
+			msgs,
+		)
+	}
+
+	// And definitely not a mode reply.
+	if findNumeric(msgs, "221") {
+		t.Fatalf(
+			"MODE query for another user leaked "+
+				"RPL_UMODEIS (221): %v",
+			msgs,
+		)
+	}
+}
+
+// TestUserModeOwnNickIsCaseInsensitive covers the same-nick
+// comparison. IRC nicks are case-insensitive, so a user
+// must be able to address their own modes in any case —
+// and the wire path already allows it.
+func TestUserModeOwnNickIsCaseInsensitive(t *testing.T) {
+	tserver := newTestServer(t)
+
+	token := tserver.createSession("mixedcase")
+	_, lastID := tserver.pollMessages(token, 0)
+
+	tserver.sendCommand(token, map[string]any{
+		commandKey: "MODE",
+		toKey:      "MixedCase",
+		bodyKey:    []string{"+w"},
+	})
+
+	msgs, _ := tserver.pollMessages(token, lastID)
+
+	if findNumeric(msgs, "502") {
+		t.Fatalf(
+			"own nick in different case rejected with "+
+				"ERR_USERSDONTMATCH (502): %v",
+			msgs,
+		)
+	}
+
+	msg := findNumericWithParams(msgs, "221")
+	if msg == nil {
+		t.Fatalf(
+			"expected RPL_UMODEIS (221), got %v", msgs,
+		)
+	}
+
+	body := getNumericBody(msg)
+	if !strings.Contains(body, "w") {
+		t.Fatalf(
+			"expected 'w' to be set, got %q", body,
+		)
+	}
+}
+
 // getNumericBody extracts the body text from a numeric
 // message. The body is stored as a JSON array; this
 // returns the first element.

internal/ircserver/commands.go

@@ -8,29 +8,10 @@ import (
 	"strings"
 	"time"
 
-	"sneak.berlin/go/neoirc/internal/globals"
 	"sneak.berlin/go/neoirc/internal/service"
 	"sneak.berlin/go/neoirc/pkg/irc"
 )
 
-// versionString returns the server version for IRC
-// responses, falling back to "neoirc-dev" when globals
-// are not set (e.g. during tests).
-func versionString() string {
-	name := globals.Appname
-	ver := globals.Version
-
-	if name == "" {
-		name = "neoirc"
-	}
-
-	if ver == "" {
-		ver = "dev"
-	}
-
-	return name + "-" + ver
-}
-
 // sendIRCError maps a service.IRCError to an IRC numeric
 // reply on the wire.
 func (c *Conn) sendIRCError(err error) {
@@ -368,7 +349,10 @@ func (c *Conn) handleQuit(msg *Message) {
 
 	c.send("ERROR :Closing Link: " + c.hostname +
 		" (Quit: " + reason + ")")
+
+	c.mu.Lock()
 	c.closed = true
+	c.mu.Unlock()
 }
 
 // handleTopic gets or sets a channel topic via the shared
@@ -719,7 +703,7 @@ func (c *Conn) handleUserMode(
 ) {
 	target := msg.Params[0]
 
-	if !strings.EqualFold(target, c.nick) {
+	if !strings.EqualFold(target, c.currentNick()) {
 		c.sendNumeric(
 			irc.ErrUsersDoNotMatch,
 			"Can't change mode for other users",
@@ -730,7 +714,21 @@ func (c *Conn) handleUserMode(
 
 	// Mode query (no mode string).
 	if len(msg.Params) < 2 { //nolint:mnd
-		modes := c.svc.QueryUserMode(ctx, c.sessionID)
+		modes, err := c.svc.QueryUserMode(
+			ctx, c.sessionID,
+		)
+		if err != nil {
+			c.log.Error(
+				"query user mode failed", "error", err,
+			)
+			c.sendNumeric(
+				irc.ErrUmodeUnknownFlag,
+				"Unable to read user modes",
+			)
+
+			return
+		}
+
 		c.sendNumeric(irc.RplUmodeIs, modes)
 
 		return
@@ -1349,22 +1347,16 @@ func (c *Conn) handleUserhost(
 }
 
 // handleVersion replies with the server version string.
-func (c *Conn) handleVersion(ctx context.Context) {
-	_ = ctx
-
-	version := versionString()
-
+func (c *Conn) handleVersion() {
 	c.sendNumeric(
 		irc.RplVersion,
-		version+".", c.cfg.ServerName,
+		c.svc.ServerVersion()+".", c.cfg.ServerName,
 		"",
 	)
 }
 
 // handleAdmin replies with server admin info.
-func (c *Conn) handleAdmin(ctx context.Context) {
-	_ = ctx
-
+func (c *Conn) handleAdmin() {
 	srvName := c.cfg.ServerName
 
 	c.sendNumeric(
@@ -1389,16 +1381,8 @@ func (c *Conn) handleAdmin(ctx context.Context) {
 }
 
 // handleInfo replies with server software info.
-func (c *Conn) handleInfo(ctx context.Context) {
-	_ = ctx
-
-	infoLines := []string{
-		"neoirc — IRC semantics over HTTP",
-		"Version: " + versionString(),
-		"Written in Go",
-	}
-
-	for _, line := range infoLines {
+func (c *Conn) handleInfo() {
+	for _, line := range c.svc.InfoLines() {
 		c.sendNumeric(irc.RplInfo, line)
 	}
 
@@ -1409,9 +1393,7 @@ func (c *Conn) handleInfo(ctx context.Context) {
 }
 
 // handleTime replies with the server's current time.
-func (c *Conn) handleTime(ctx context.Context) {
-	_ = ctx
-
+func (c *Conn) handleTime() {
 	srvName := c.cfg.ServerName
 
 	c.sendNumeric(
@@ -1455,7 +1437,9 @@ func (c *Conn) handleKillCmd(
 		reason = msg.Params[1]
 	}
 
-	if targetNick == c.nick {
+	killerNick := c.currentNick()
+
+	if strings.EqualFold(targetNick, killerNick) {
 		c.sendNumeric(
 			irc.ErrCantKillServer,
 			"You cannot KILL yourself",
@@ -1476,9 +1460,12 @@ func (c *Conn) handleKillCmd(
 		return
 	}
 
-	quitReason := "Killed (" + c.nick + " (" + reason + "))"
+	quitReason := "Killed (" + killerNick +
+		" (" + reason + "))"
 
-	c.svc.BroadcastQuit(
+	// KillSession broadcasts the QUIT, deletes the session
+	// and disconnects the victim's wire connection.
+	c.svc.KillSession(
 		ctx, targetSID, targetNick, quitReason,
 	)
 }
@@ -1530,7 +1517,7 @@ func (c *Conn) handleWallopsCmd(
 		}
 
 		_, _, _ = c.svc.FanOut(
-			ctx, irc.CmdWallops, c.nick, "*",
+			ctx, irc.CmdWallops, c.currentNick(), "*",
 			nil, body, nil, wallopsSIDs,
 		)
 	}

internal/ircserver/conn.go

@@ -46,6 +46,12 @@ type Conn struct {
 	serverSfx string
 	commands  map[string]cmdHandler
 
+	// writeMu serializes writes to conn.  A connection is
+	// written to by its own read loop, by its relay
+	// goroutine, and — when an operator KILLs it — by
+	// another client's goroutine.
+	writeMu sync.Mutex
+
 	mu        sync.Mutex
 	nick      string
 	username  string
@@ -62,6 +68,7 @@ type Conn struct {
 
 	lastQueueID int64
 	closed      bool
+	killed      bool
 	cancel      context.CancelFunc
 }
 
@@ -98,6 +105,47 @@ func newConn(
 	return conn
 }
 
+// Disconnect terminates the connection on behalf of an
+// operator KILL issued from either transport.  The victim
+// is told why, then its socket is closed so that the read
+// loop unblocks and serve() returns; without the close the
+// victim would keep a socket that looks alive but silently
+// delivers nothing.  Disconnect is called from the killer's
+// goroutine, never the victim's.
+func (c *Conn) Disconnect(reason string) {
+	c.mu.Lock()
+
+	if c.closed {
+		c.mu.Unlock()
+
+		return
+	}
+
+	c.closed = true
+	c.killed = true
+	nick := c.nick
+	host := c.hostname
+	c.mu.Unlock()
+
+	if nick == "" {
+		nick = "*"
+	}
+
+	c.sendFromServer(irc.CmdKill, nick, reason)
+	c.send(
+		"ERROR :Closing Link: " + host +
+			" (" + reason + ")",
+	)
+
+	// Stop the relay goroutine, which would otherwise keep
+	// polling a queue belonging to a deleted session.
+	if c.cancel != nil {
+		c.cancel()
+	}
+
+	c.conn.Close() //nolint:errcheck,gosec
+}
+
 // buildCommandMap returns a map from IRC command strings
 // to handler functions.
 func (c *Conn) buildCommandMap() map[string]cmdHandler {
@@ -131,10 +179,10 @@ func (c *Conn) buildCommandMap() map[string]cmdHandler {
 			c.handleCAP(msg)
 		},
 		"USERHOST":     c.handleUserhost,
-		irc.CmdVersion: func(ctx context.Context, _ *Message) { c.handleVersion(ctx) },
-		irc.CmdAdmin:   func(ctx context.Context, _ *Message) { c.handleAdmin(ctx) },
-		irc.CmdInfo:    func(ctx context.Context, _ *Message) { c.handleInfo(ctx) },
-		irc.CmdTime:    func(ctx context.Context, _ *Message) { c.handleTime(ctx) },
+		irc.CmdVersion: func(context.Context, *Message) { c.handleVersion() },
+		irc.CmdAdmin:   func(context.Context, *Message) { c.handleAdmin() },
+		irc.CmdInfo:    func(context.Context, *Message) { c.handleInfo() },
+		irc.CmdTime:    func(context.Context, *Message) { c.handleTime() },
 		irc.CmdKill:    c.handleKillCmd,
 		irc.CmdWallops: c.handleWallopsCmd,
 	}
@@ -185,7 +233,7 @@ func (c *Conn) serve(ctx context.Context) {
 
 		c.handleMessage(ctx, msg)
 
-		if c.closed {
+		if c.isClosed() {
 			return
 		}
 	}
@@ -194,22 +242,52 @@ func (c *Conn) serve(ctx context.Context) {
 func (c *Conn) cleanup(ctx context.Context) {
 	c.mu.Lock()
 	wasRegistered := c.registered
+	wasKilled := c.killed
 	sessID := c.sessionID
 	nick := c.nick
 	c.closed = true
 	c.mu.Unlock()
 
 	if wasRegistered && sessID > 0 {
+		c.svc.UnregisterWireConn(sessID, c)
+
+		// A KILLed session has already been broadcast and
+		// deleted by the killer; broadcasting again would
+		// fan out a QUIT for a session row that is gone.
+		if !wasKilled {
 			c.svc.BroadcastQuit(
 				ctx, sessID, nick, "Connection closed",
 			)
 		}
+	}
 
 	c.conn.Close() //nolint:errcheck,gosec
 }
 
+// isClosed reports whether the connection has been marked
+// for teardown, either by QUIT or by an operator KILL.
+func (c *Conn) isClosed() bool {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	return c.closed
+}
+
+// currentNick returns the connection's registered nick.
+// c.nick is written under c.mu during registration and
+// NICK changes, so every read must take the mutex.
+func (c *Conn) currentNick() string {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	return c.nick
+}
+
 // send writes a formatted IRC line to the connection.
 func (c *Conn) send(line string) {
+	c.writeMu.Lock()
+	defer c.writeMu.Unlock()
+
 	_ = c.conn.SetWriteDeadline(
 		time.Now().Add(writeTimeout),
 	)
@@ -392,7 +470,10 @@ func (c *Conn) completeRegistration(ctx context.Context) {
 			"failed to create session", "error", err,
 		)
 		c.send("ERROR :Internal server error")
+
+		c.mu.Lock()
 		c.closed = true
+		c.mu.Unlock()
 
 		return
 	}
@@ -403,6 +484,10 @@ func (c *Conn) completeRegistration(ctx context.Context) {
 	c.registered = true
 	c.mu.Unlock()
 
+	// Make this connection reachable by session ID so that
+	// KILL from either transport can disconnect it.
+	c.svc.RegisterWireConn(sessionID, c)
+
 	// If PASS was provided before registration, set the
 	// session password.
 	if c.passWord != "" && len(c.passWord) >= minPasswordLen {

internal/ircserver/export_test.go

@@ -4,10 +4,12 @@ import (
 	"context"
 	"log/slog"
 	"net"
+	"time"
 
 	"sneak.berlin/go/neoirc/internal/broker"
 	"sneak.berlin/go/neoirc/internal/config"
 	"sneak.berlin/go/neoirc/internal/db"
+	"sneak.berlin/go/neoirc/internal/globals"
 	"sneak.berlin/go/neoirc/internal/service"
 )
 
@@ -19,8 +21,14 @@ func NewTestServer(
 	database *db.Database,
 	brk *broker.Broker,
 ) *Server {
+	globs := &globals.Globals{
+		Appname:   "neoirc",
+		Version:   "test",
+		StartTime: time.Now(),
+	}
+
 	svc := service.NewTestService(
-		database, brk, cfg, log,
+		database, brk, cfg, globs, log,
 	)
 
 	return &Server{ //nolint:exhaustruct

internal/ircserver/integration_test.go

@@ -923,7 +923,11 @@ func TestIntegrationTime(t *testing.T) {
 }
 
 // TestIntegrationKill verifies the KILL command: oper can
-// kill a user, non-oper cannot.
+// kill a user, non-oper cannot, and — most importantly —
+// that the victim is actually disconnected rather than
+// merely announced as having quit.
+//
+//nolint:funlen // one KILL scenario asserted end to end
 func TestIntegrationKill(t *testing.T) {
 	t.Parallel()
 
@@ -965,6 +969,24 @@ func TestIntegrationKill(t *testing.T) {
 	// Oper KILL should succeed.
 	alice.send("KILL bob :bad behavior")
 
+	// The victim must be told why and then disconnected.
+	// Reading to EOF is the assertion that matters: a KILL
+	// that only broadcasts a QUIT leaves bob holding a
+	// socket that looks alive but delivers nothing.
+	bobLines := bob.readUntilClosed()
+	assertContains(
+		t, bobLines, "KILL",
+		"victim receives KILL before disconnect",
+	)
+	assertContains(
+		t, bobLines, "ERROR :Closing Link",
+		"victim receives ERROR before disconnect",
+	)
+	assertContains(
+		t, bobLines, "bad behavior",
+		"KILL reason delivered to victim",
+	)
+
 	// alice should see bob's QUIT relay.
 	aliceSeesQuit := alice.readUntil(func(l string) bool {
 		return strings.Contains(l, "QUIT") &&
@@ -975,6 +997,32 @@ func TestIntegrationKill(t *testing.T) {
 		"KILL reason in QUIT message",
 	)
 
+	// bob must be gone from the channel member list.
+	alice.send("NAMES #killtest")
+
+	aliceNames := alice.readUntil(func(l string) bool {
+		return strings.Contains(l, " 366 ")
+	})
+	assertContains(
+		t, aliceNames, "alice",
+		"alice still in NAMES after killing bob",
+	)
+	assertNotContains(
+		t, aliceNames, "bob",
+		"killed user must not appear in NAMES",
+	)
+
+	// ...nor from WHO.
+	alice.send("WHO #killtest")
+
+	aliceWho := alice.readUntil(func(l string) bool {
+		return strings.Contains(l, " 315 ")
+	})
+	assertNotContains(
+		t, aliceWho, "bob",
+		"killed user must not appear in WHO",
+	)
+
 	// KILL nonexistent nick.
 	alice.send("KILL nobody123 :gone")
 

internal/ircserver/server_test.go

@@ -291,6 +291,36 @@ func (tc *testClient) register(nick string) []string {
 	})
 }
 
+// readUntilClosed reads until the peer closes the
+// connection, returning the lines received first.  It
+// fails the test if the connection is still open when the
+// read deadline expires, which is what a KILL that never
+// terminates the victim's socket looks like.
+func (tc *testClient) readUntilClosed() []string {
+	tc.t.Helper()
+
+	_ = tc.conn.SetReadDeadline(
+		time.Now().Add(testTimeout),
+	)
+
+	var lines []string
+
+	for tc.scanner.Scan() {
+		lines = append(lines, tc.scanner.Text())
+	}
+
+	err := tc.scanner.Err()
+	if err != nil {
+		tc.t.Fatalf(
+			"expected EOF on victim socket, got %v "+
+				"(lines: %v)",
+			err, lines,
+		)
+	}
+
+	return lines
+}
+
 // assertContains checks that at least one line matches the
 // given substring.
 func assertContains(
@@ -309,6 +339,27 @@ func assertContains(
 	t.Errorf("did not find %q in output: %s", substr, description)
 }
 
+// assertNotContains checks that no line matches the given
+// substring.
+func assertNotContains(
+	t *testing.T,
+	lines []string,
+	substr, description string,
+) {
+	t.Helper()
+
+	for _, line := range lines {
+		if strings.Contains(line, substr) {
+			t.Errorf(
+				"unexpectedly found %q in output: %s",
+				substr, description,
+			)
+
+			return
+		}
+	}
+}
+
 // joinAndDrain joins a channel and reads until
 // RPL_ENDOFNAMES.
 func (tc *testClient) joinAndDrain(channel string) {

internal/server/server.go

@@ -92,19 +92,6 @@ func New(
 	return srv, nil
 }
 
-// Run configures the server and begins serving. It blocks
-// until shutdown is signalled. Kept for external callers
-// that embed the server outside fx. The fx lifecycle now
-// performs setup synchronously in OnStart and invokes
-// serve directly in a goroutine, so this is only used when
-// the server is driven by hand.
-func (srv *Server) Run() {
-	srv.configure()
-	srv.enableSentry()
-	srv.SetupRoutes()
-	srv.serve()
-}
-
 // ServeHTTP delegates to the chi router.
 func (srv *Server) ServeHTTP(
 	writer http.ResponseWriter,

internal/service/service.go

@@ -10,11 +10,14 @@ import (
 	"log/slog"
 	"strconv"
 	"strings"
+	"sync"
+	"time"
 
 	"go.uber.org/fx"
 	"sneak.berlin/go/neoirc/internal/broker"
 	"sneak.berlin/go/neoirc/internal/config"
 	"sneak.berlin/go/neoirc/internal/db"
+	"sneak.berlin/go/neoirc/internal/globals"
 	"sneak.berlin/go/neoirc/internal/logger"
 	"sneak.berlin/go/neoirc/pkg/irc"
 )
@@ -27,6 +30,18 @@ type Params struct {
 	Config   *config.Config
 	Database *db.Database
 	Broker   *broker.Broker
+	Globals  *globals.Globals
+}
+
+// WireConn is a live client connection that a transport
+// registers with the service so that commands such as KILL
+// can reach it.  The IRC wire server registers one per
+// registered connection; the HTTP transport has no
+// long-lived socket and registers nothing.
+type WireConn interface {
+	// Disconnect terminates the connection, telling the
+	// client why before closing the socket.
+	Disconnect(reason string)
 }
 
 // Service provides shared business logic for IRC commands.
@@ -34,16 +49,22 @@ type Service struct {
 	db      *db.Database
 	broker  *broker.Broker
 	config  *config.Config
+	globals *globals.Globals
 	log     *slog.Logger
+
+	wireMu    sync.Mutex
+	wireConns map[int64]WireConn
 }
 
 // New creates a new Service.
 func New(params Params) *Service {
-	return &Service{
+	return &Service{ //nolint:exhaustruct // mutex zero value
 		db:        params.Database,
 		broker:    params.Broker,
 		config:    params.Config,
+		globals:   params.Globals,
 		log:       params.Logger.Get(),
+		wireConns: make(map[int64]WireConn),
 	}
 }
 
@@ -53,13 +74,105 @@ func NewTestService(
 	database *db.Database,
 	brk *broker.Broker,
 	cfg *config.Config,
+	globs *globals.Globals,
 	log *slog.Logger,
 ) *Service {
-	return &Service{
+	return &Service{ //nolint:exhaustruct // mutex zero value
 		db:        database,
 		broker:    brk,
 		config:    cfg,
+		globals:   globs,
 		log:       log,
+		wireConns: make(map[int64]WireConn),
+	}
+}
+
+// ServerVersion returns the canonical server version string
+// used by every transport, e.g. "neoirc-1.2.3".  Both the
+// IRC wire protocol and the HTTP API must report the same
+// string, so this is the only place it is built.
+func (s *Service) ServerVersion() string {
+	name := "neoirc"
+	ver := "dev"
+
+	if s.globals != nil {
+		if s.globals.Appname != "" {
+			name = s.globals.Appname
+		}
+
+		if s.globals.Version != "" {
+			ver = s.globals.Version
+		}
+	}
+
+	return name + "-" + ver
+}
+
+// InfoLines returns the RPL_INFO body.  Both transports
+// send exactly these lines so that INFO does not diverge
+// between the wire protocol and the HTTP API.
+func (s *Service) InfoLines() []string {
+	started := "unknown"
+	if s.globals != nil && !s.globals.StartTime.IsZero() {
+		started = s.globals.StartTime.Format(time.RFC1123)
+	}
+
+	return []string{
+		"neoirc — IRC semantics over HTTP",
+		"Version: " + s.ServerVersion(),
+		"Written in Go",
+		"Started: " + started,
+	}
+}
+
+// RegisterWireConn associates a live wire connection with
+// its session ID so that KillSession can reach it.
+func (s *Service) RegisterWireConn(
+	sessionID int64,
+	conn WireConn,
+) {
+	s.wireMu.Lock()
+	defer s.wireMu.Unlock()
+
+	s.wireConns[sessionID] = conn
+}
+
+// UnregisterWireConn removes the association created by
+// RegisterWireConn.  It is a no-op if the session has
+// already been rebound to a different connection.
+func (s *Service) UnregisterWireConn(
+	sessionID int64,
+	conn WireConn,
+) {
+	s.wireMu.Lock()
+	defer s.wireMu.Unlock()
+
+	if s.wireConns[sessionID] == conn {
+		delete(s.wireConns, sessionID)
+	}
+}
+
+// KillSession forcibly removes a user from the server: the
+// victim's channel peers are told via QUIT, the victim's
+// session is deleted, and any live wire connection it holds
+// is disconnected.  Both the IRC KILL command and the HTTP
+// KILL endpoint route through here so the two transports
+// cannot diverge.
+func (s *Service) KillSession(
+	ctx context.Context,
+	sessionID int64,
+	nick, reason string,
+) {
+	s.BroadcastQuit(ctx, sessionID, nick, reason)
+
+	// A session with no registered wire connection (an
+	// HTTP-only client) has nothing left to disconnect.
+	s.wireMu.Lock()
+	conn := s.wireConns[sessionID]
+	s.wireMu.Unlock()
+
+	if conn != nil {
+		conn.Disconnect(reason)
 	}
 }
 
@@ -792,26 +905,42 @@ func (s *Service) QueryChannelMode(
 }
 
 // QueryUserMode returns the current user mode string for
-// the given session (e.g. "+ow", "+w", "+").
+// the given session (e.g. "+ow", "+w", "+").  A database
+// failure is returned rather than being reported as an
+// unset flag: an unreadable mode is not the same as an
+// absent one, and reporting "+" for either would tell the
+// user they are de-opered when the truth is unknown.
 func (s *Service) QueryUserMode(
 	ctx context.Context,
 	sessionID int64,
-) string {
+) (string, error) {
 	modes := "+"
 
 	isOper, err := s.db.IsSessionOper(ctx, sessionID)
-	if err == nil && isOper {
+	if err != nil {
+		return "", fmt.Errorf(
+			"query oper flag: %w", err,
+		)
+	}
+
+	if isOper {
 		modes += "o"
 	}
 
 	isWallops, err := s.db.IsSessionWallops(
 		ctx, sessionID,
 	)
-	if err == nil && isWallops {
+	if err != nil {
+		return "", fmt.Errorf(
+			"query wallops flag: %w", err,
+		)
+	}
+
+	if isWallops {
 		modes += "w"
 	}
 
-	return modes
+	return modes, nil
 }
 
 // userModeOp is a single parsed user-mode change collected
@@ -847,7 +976,7 @@ func (s *Service) ApplyUserMode(
 		}
 	}
 
-	return s.QueryUserMode(ctx, sessionID), nil
+	return s.QueryUserMode(ctx, sessionID)
 }
 
 // parseUserModeString validates and parses a user-mode

internal/service/service_test.go

@@ -11,6 +11,7 @@ import (
 	"fmt"
 	"os"
 	"testing"
+	"time"
 
 	"go.uber.org/fx"
 	"go.uber.org/fx/fxtest"
@@ -55,9 +56,10 @@ func newTestEnv(t *testing.T) *testEnv {
 	app := fxtest.New(t,
 		fx.Provide(
 			func() *globals.Globals {
-				return &globals.Globals{ //nolint:exhaustruct
+				return &globals.Globals{
 					Appname:   "neoirc-test",
 					Version:   "test",
+					StartTime: time.Now(),
 				}
 			},
 			logger.New,
@@ -371,7 +373,11 @@ func TestQueryUserMode(t *testing.T) {
 	sid := createSession(ctx, t, env.db, "alice")
 
 	// Fresh session has no modes.
-	modes := env.svc.QueryUserMode(ctx, sid)
+	modes, err := env.svc.QueryUserMode(ctx, sid)
+	if err != nil {
+		t.Fatalf("query user mode: %v", err)
+	}
+
 	if modes != "+" {
 		t.Errorf("expected +, got %s", modes)
 	}
@@ -379,7 +385,11 @@ func TestQueryUserMode(t *testing.T) {
 	// Set wallops.
 	_ = env.db.SetSessionWallops(ctx, sid, true)
 
-	modes = env.svc.QueryUserMode(ctx, sid)
+	modes, err = env.svc.QueryUserMode(ctx, sid)
+	if err != nil {
+		t.Fatalf("query user mode: %v", err)
+	}
+
 	if modes != "+w" {
 		t.Errorf("expected +w, got %s", modes)
 	}
@@ -387,7 +397,11 @@ func TestQueryUserMode(t *testing.T) {
 	// Set oper.
 	_ = env.db.SetSessionOper(ctx, sid, true)
 
-	modes = env.svc.QueryUserMode(ctx, sid)
+	modes, err = env.svc.QueryUserMode(ctx, sid)
+	if err != nil {
+		t.Fatalf("query user mode: %v", err)
+	}
+
 	if modes != "+ow" {
 		t.Errorf("expected +ow, got %s", modes)
 	}