Add rate limiting

This should fix #65, although it may be expanded in the future.

Default settings for limits can be changed or disabled in the settings.
Default values:
- Chat: 1 second
- Duplicate chat: 30 seconds
- /nick: 5 minutes
- /auth: 5 seconds
- /color: 1 minute

Creation of the chat Client object has been moved from ChatRoom.Join()
to NewClient().  This function also handles setting the initial name.

chatclient.go

@@ -5,6 +5,7 @@ import (
 	"html"
 	"regexp"
 	"strings"
+	"time"
 	"unicode"
 
 	"github.com/zorchenhimer/MovieNight/common"
@@ -25,6 +26,36 @@ type Client struct {
 	IsColorForced bool
 	IsNameForced  bool
 	regexName     *regexp.Regexp
+
+	// Times since last event.  use time.Duration.Since()
+	nextChat  time.Time // rate limit chat messages
+	nextNick  time.Time // rate limit nickname changes
+	nextColor time.Time // rate limit color changes
+	nextAuth  time.Time // rate limit failed auth attempts.  Sould prolly have a backoff policy.
+	authTries int       // number of failed auth attempts
+
+	nextDuplicate time.Time
+	lastMsg       string
+}
+
+func NewClient(connection *chatConnection, room *ChatRoom, name, color string) (*Client, error) {
+	c := &Client{
+		conn:      connection,
+		belongsTo: room,
+		color:     color,
+	}
+
+	if err := c.setName(name); err != nil {
+		return nil, fmt.Errorf("could not set client name to %#v: %v", name, err)
+	}
+
+	// Set initial vaules to their rate limit duration in the past.
+	c.nextChat = time.Now()
+	c.nextNick = time.Now()
+	c.nextColor = time.Now()
+	c.nextAuth = time.Now()
+
+	return c, nil
 }
 
 //Client has a new message to broadcast
@@ -85,11 +116,42 @@ func (cl *Client) NewMsg(data common.ClientData) {
 			}
 
 		} else {
+			// Limit the rate of sent chat messages.  Ignore mods and admins
+			if time.Now().Before(cl.nextChat) && cl.CmdLevel == common.CmdlUser {
+				err := cl.SendChatData(common.NewChatMessage("", "",
+					"Slow down.",
+					common.CmdlUser,
+					common.MsgCommandResponse))
+				if err != nil {
+					common.LogErrorf("Unable to send slowdown for chat: %v", err)
+				}
+				return
+			}
+
 			// Trim long messages
 			if len(msg) > 400 {
 				msg = msg[0:400]
 			}
 
+			// Limit the rate of duplicate messages.  Ignore mods and admins.
+			// Only checks the last message.
+			if strings.TrimSpace(strings.ToLower(msg)) == cl.lastMsg &&
+				time.Now().Before(cl.nextDuplicate) &&
+				cl.CmdLevel == common.CmdlUser {
+				err := cl.SendChatData(common.NewChatMessage("", "",
+					common.ParseEmotes("You already sent that PeepoSus"),
+					common.CmdlUser,
+					common.MsgCommandResponse))
+				if err != nil {
+					common.LogErrorf("Unable to send slowdown for chat: %v", err)
+				}
+				return
+			}
+
+			cl.nextChat = time.Now().Add(time.Second * settings.RateLimitChat)
+			cl.nextDuplicate = time.Now().Add(time.Second * settings.RateLimitDuplicate)
+			cl.lastMsg = strings.TrimSpace(strings.ToLower(msg))
+
 			common.LogChatf("[chat] <%s> %q\n", cl.name, msg)
 
 			// Enable links for mods and admins
@@ -188,6 +250,7 @@ func (cl *Client) setName(s string) error {
 
 	cl.name = s
 	cl.regexName = regex
+	cl.conn.clientName = s
 	return nil
 }
 

chatcommands.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"html"
 	"strings"
+	"time"
 
 	"github.com/zorchenhimer/MovieNight/common"
 )
@@ -126,6 +127,10 @@ var commands = &CommandControl{
 					return "You are not allowed to change your color."
 				}
 
+				if time.Now().Before(cl.nextColor) && cl.CmdLevel == common.CmdlUser {
+					return fmt.Sprintf("Slow down. You can change your color in %0.0f seconds.", time.Until(cl.nextColor).Seconds())
+				}
+
 				if len(args) == 0 {
 					cl.setColor(common.RandomColor())
 					return "Random color chosen: " + cl.color
@@ -136,6 +141,8 @@ var commands = &CommandControl{
 					return "To choose a specific color use the format <i>/color #c029ce</i>.  Hex values expected."
 				}
 
+				cl.nextColor = time.Now().Add(time.Second * settings.RateLimitColor)
+
 				err := cl.setColor(args[0])
 				if err != nil {
 					common.LogErrorf("[color] could not send color update to client: %v\n", err)
@@ -163,6 +170,14 @@ var commands = &CommandControl{
 					return "You are already authenticated."
 				}
 
+				// TODO: handle backoff policy
+				if time.Now().Before(cl.nextAuth) {
+					cl.nextAuth = time.Now().Add(time.Second * settings.RateLimitAuth)
+					return "Slow down."
+				}
+				cl.authTries += 1 // this isn't used yet
+				cl.nextAuth = time.Now().Add(time.Second * settings.RateLimitAuth)
+
 				pw := html.UnescapeString(strings.Join(args, " "))
 
 				if settings.AdminPassword == pw {
@@ -196,6 +211,12 @@ var commands = &CommandControl{
 		common.CNNick.String(): Command{
 			HelpText: "Change display name",
 			Function: func(cl *Client, args []string) string {
+				if time.Now().Before(cl.nextNick) {
+					//cl.nextNick = time.Now().Add(time.Second * settings.RateLimitNick)
+					return fmt.Sprintf("Slow down. You can change your nick in %0.0f seconds.", time.Until(cl.nextNick).Seconds())
+				}
+				cl.nextNick = time.Now().Add(time.Second * settings.RateLimitNick)
+
 				if len(args) == 0 {
 					return "Missing name to change to."
 				}

chatroom.go

@@ -96,16 +96,9 @@ func (cr *ChatRoom) Join(name, uid string) (*Client, error) {
 		}
 	}
 
-	conn.clientName = name
+	client, err := NewClient(conn, cr, name, common.RandomColor())
-	client := &Client{
-		conn:      conn,
-		belongsTo: cr,
-		color:     common.RandomColor(),
-	}
-
-	err := client.setName(name)
 	if err != nil {
-		return nil, fmt.Errorf("could not set client name to %#v: %v", name, err)
+		return nil, fmt.Errorf("Unable to join client: %v", err)
 	}
 
 	host := client.Host()

settings.go

@@ -33,6 +33,13 @@ type Settings struct {
 	LogLevel        common.LogLevel
 	LogFile         string
 
+	// Rate limiting stuff, in seconds
+	RateLimitChat      time.Duration
+	RateLimitNick      time.Duration
+	RateLimitColor     time.Duration
+	RateLimitAuth      time.Duration
+	RateLimitDuplicate time.Duration // Amount of seconds between allowed duplicate messages
+
 	// Send the NoCache header?
 	NoCache bool
 }
@@ -72,6 +79,42 @@ func LoadSettings(filename string) (*Settings, error) {
 		return nil, fmt.Errorf("unable to generate admin password: %s", err)
 	}
 
+	if s.RateLimitChat == -1 {
+		s.RateLimitChat = 0
+	} else if s.RateLimitChat <= 0 {
+		s.RateLimitChat = 1
+	}
+
+	if s.RateLimitNick == -1 {
+		s.RateLimitNick = 0
+	} else if s.RateLimitNick <= 0 {
+		s.RateLimitNick = 300
+	}
+
+	if s.RateLimitColor == -1 {
+		s.RateLimitColor = 0
+	} else if s.RateLimitColor <= 0 {
+		s.RateLimitColor = 60
+	}
+
+	if s.RateLimitAuth == -1 {
+		s.RateLimitAuth = 0
+	} else if s.RateLimitAuth <= 0 {
+		s.RateLimitAuth = 5
+	}
+
+	if s.RateLimitDuplicate == -1 {
+		s.RateLimitDuplicate = 0
+	} else if s.RateLimitDuplicate <= 0 {
+		s.RateLimitDuplicate = 30
+	}
+
+	// Print this stuff before we multiply it by time.Second
+	common.LogInfof("RateLimitChat: %v", s.RateLimitChat)
+	common.LogInfof("RateLimitNick: %v", s.RateLimitNick)
+	common.LogInfof("RateLimitColor: %v", s.RateLimitColor)
+	common.LogInfof("RateLimitAuth: %v", s.RateLimitAuth)
+
 	// Don't use LogInfof() here.  Log isn't setup yet when LoadSettings() is called from init().
 	fmt.Printf("Settings reloaded.  New admin password: %s\n", s.AdminPassword)