add IP to sessions, IP+hostname to clients

- Add ip column to sessions table (real client IP of session creator)
- Add ip and hostname columns to clients table (per-connection tracking)
- Update CreateSession, RegisterUser, LoginUser to store new fields
- Add GetClientHostInfo query method
- Update SessionHostInfo to include IP
- Extract executeCreateSession to fix funlen lint
- Add tests for session IP, client IP/hostname, login client tracking
- Update README with new field documentation

internal/db/queries.go

@@ -102,7 +102,7 @@ func FormatHostmask(nick, username, hostname string) string {
 // CreateSession registers a new session and its first client.
 func (database *Database) CreateSession(
 	ctx context.Context,
-	nick, username, hostname string,
+	nick, username, hostname, remoteIP string,
 ) (int64, int64, string, error) {
 	if username == "" {
 		username = nick
@@ -127,10 +127,11 @@ func (database *Database) CreateSession(
 
 	res, err := transaction.ExecContext(ctx,
 		`INSERT INTO sessions
-		 (uuid, nick, username, hostname,
+		 (uuid, nick, username, hostname, ip,
 		  created_at, last_seen)
-		 VALUES (?, ?, ?, ?, ?, ?)`,
-		sessionUUID, nick, username, hostname, now, now)
+		 VALUES (?, ?, ?, ?, ?, ?, ?)`,
+		sessionUUID, nick, username, hostname,
+		remoteIP, now, now)
 	if err != nil {
 		_ = transaction.Rollback()
 
@@ -145,10 +146,11 @@ func (database *Database) CreateSession(
 
 	clientRes, err := transaction.ExecContext(ctx,
 		`INSERT INTO clients
-		 (uuid, session_id, token,
+		 (uuid, session_id, token, ip, hostname,
 		  created_at, last_seen)
-		 VALUES (?, ?, ?, ?, ?)`,
-		clientUUID, sessionID, tokenHash, now, now)
+		 VALUES (?, ?, ?, ?, ?, ?, ?)`,
+		clientUUID, sessionID, tokenHash,
+		remoteIP, hostname, now, now)
 	if err != nil {
 		_ = transaction.Rollback()
 
@@ -236,14 +238,16 @@ func (database *Database) GetSessionByNick(
 	return sessionID, nil
 }
 
-// SessionHostInfo holds the username and hostname for a session.
+// SessionHostInfo holds the username, hostname, and IP
+// for a session.
 type SessionHostInfo struct {
 	Username string
 	Hostname string
+	IP       string
 }
 
-// GetSessionHostInfo returns the username and hostname
-// for a session.
+// GetSessionHostInfo returns the username, hostname,
+// and IP for a session.
 func (database *Database) GetSessionHostInfo(
 	ctx context.Context,
 	sessionID int64,
@@ -252,10 +256,10 @@ func (database *Database) GetSessionHostInfo(
 
 	err := database.conn.QueryRowContext(
 		ctx,
-		`SELECT username, hostname
+		`SELECT username, hostname, ip
 		 FROM sessions WHERE id = ?`,
 		sessionID,
-	).Scan(&info.Username, &info.Hostname)
+	).Scan(&info.Username, &info.Hostname, &info.IP)
 	if err != nil {
 		return nil, fmt.Errorf(
 			"get session host info: %w", err,
@@ -265,6 +269,35 @@ func (database *Database) GetSessionHostInfo(
 	return &info, nil
 }
 
+// ClientHostInfo holds the IP and hostname for a client.
+type ClientHostInfo struct {
+	IP       string
+	Hostname string
+}
+
+// GetClientHostInfo returns the IP and hostname for a
+// client.
+func (database *Database) GetClientHostInfo(
+	ctx context.Context,
+	clientID int64,
+) (*ClientHostInfo, error) {
+	var info ClientHostInfo
+
+	err := database.conn.QueryRowContext(
+		ctx,
+		`SELECT ip, hostname
+		 FROM clients WHERE id = ?`,
+		clientID,
+	).Scan(&info.IP, &info.Hostname)
+	if err != nil {
+		return nil, fmt.Errorf(
+			"get client host info: %w", err,
+		)
+	}
+
+	return &info, nil
+}
+
 // GetChannelByName returns the channel ID for a name.
 func (database *Database) GetChannelByName(
 	ctx context.Context,