From 955cdbdfef052fb0ea6e8ab24f4df2e47af1d0a7 Mon Sep 17 00:00:00 2001
From: Shivaram Lingamneni <slingamn@cs.stanford.edu>
Date: Tue, 28 Jan 2020 22:27:56 -0500
Subject: [PATCH] impose throttle checks on HS TAKE

---
 irc/accounts.go | 40 ++++++++++++++++++++++++++++++++++++++--
 irc/hostserv.go | 36 +++++++++++++++---------------------
 2 files changed, 53 insertions(+), 23 deletions(-)

diff --git a/irc/accounts.go b/irc/accounts.go
index 784d9dd3..f926e9c1 100644
--- a/irc/accounts.go
+++ b/irc/accounts.go
@@ -1142,12 +1142,40 @@ type PendingVHostRequest struct {
 	Account string
 }
 
+type vhostThrottleExceeded struct {
+	timeRemaining time.Duration
+}
+
+func (vhe *vhostThrottleExceeded) Error() string {
+	return fmt.Sprintf("Wait at least %v and try again", vhe.timeRemaining)
+}
+
+func (vh *VHostInfo) checkThrottle(cooldown time.Duration) (err error) {
+	if cooldown == 0 {
+		return nil
+	}
+
+	now := time.Now().UTC()
+	elapsed := now.Sub(vh.LastRequestTime)
+	if elapsed > cooldown {
+		// success
+		vh.LastRequestTime = now
+		return nil
+	} else {
+		return &vhostThrottleExceeded{timeRemaining: cooldown - elapsed}
+	}
+}
+
 // callback type implementing the actual business logic of vhost operations
 type vhostMunger func(input VHostInfo) (output VHostInfo, err error)
 
-func (am *AccountManager) VHostSet(account string, vhost string) (result VHostInfo, err error) {
+func (am *AccountManager) VHostSet(account string, vhost string, cooldown time.Duration) (result VHostInfo, err error) {
 	munger := func(input VHostInfo) (output VHostInfo, err error) {
 		output = input
+		err = output.checkThrottle(cooldown)
+		if err != nil {
+			return
+		}
 		output.Enabled = true
 		output.ApprovedVHost = vhost
 		return
@@ -1156,9 +1184,17 @@ func (am *AccountManager) VHostSet(account string, vhost string) (result VHostIn
 	return am.performVHostChange(account, munger)
 }
 
-func (am *AccountManager) VHostRequest(account string, vhost string) (result VHostInfo, err error) {
+func (am *AccountManager) VHostRequest(account string, vhost string, cooldown time.Duration) (result VHostInfo, err error) {
 	munger := func(input VHostInfo) (output VHostInfo, err error) {
 		output = input
+		// you can update your existing request, but if you were approved or rejected,
+		// you can't spam a new request
+		if output.RequestedVHost == "" {
+			err = output.checkThrottle(cooldown)
+		}
+		if err != nil {
+			return
+		}
 		output.RequestedVHost = vhost
 		output.RejectedVHost = ""
 		output.RejectionReason = ""
diff --git a/irc/hostserv.go b/irc/hostserv.go
index 0813d82d..8cfa9220 100644
--- a/irc/hostserv.go
+++ b/irc/hostserv.go
@@ -7,7 +7,6 @@ import (
 	"errors"
 	"fmt"
 	"regexp"
-	"time"
 )
 
 const hostservHelp = `HostServ lets you manage your vhost (i.e., the string displayed
@@ -213,23 +212,13 @@ func hsRequestHandler(server *Server, client *Client, command string, params []s
 	}
 
 	accountName := client.Account()
-	account, err := server.accounts.LoadAccount(client.Account())
+	_, err := server.accounts.VHostRequest(accountName, vhost, server.Config().Accounts.VHosts.UserRequests.Cooldown)
 	if err != nil {
-		hsNotice(rb, client.t("An error occurred"))
-		return
-	}
-	elapsed := time.Since(account.VHost.LastRequestTime)
-	remainingTime := server.AccountConfig().VHosts.UserRequests.Cooldown - elapsed
-	// you can update your existing request, but if you were rejected,
-	// you can't spam a replacement request
-	if account.VHost.RequestedVHost == "" && remainingTime > 0 {
-		hsNotice(rb, fmt.Sprintf(client.t("You must wait an additional %v before making another request"), remainingTime))
-		return
-	}
-
-	_, err = server.accounts.VHostRequest(accountName, vhost)
-	if err != nil {
-		hsNotice(rb, client.t("An error occurred"))
+		if throttled, ok := err.(*vhostThrottleExceeded); ok {
+			hsNotice(rb, fmt.Sprintf(client.t("You must wait an additional %v before making another request"), throttled.timeRemaining))
+		} else {
+			hsNotice(rb, client.t("An error occurred"))
+		}
 	} else {
 		hsNotice(rb, client.t("Your vhost request will be reviewed by an administrator"))
 		chanMsg := fmt.Sprintf("Account %s requests vhost %s", accountName, vhost)
@@ -309,7 +298,7 @@ func hsSetHandler(server *Server, client *Client, command string, params []strin
 	}
 	// else: command == "del", vhost == ""
 
-	_, err := server.accounts.VHostSet(user, vhost)
+	_, err := server.accounts.VHostSet(user, vhost, 0)
 	if err != nil {
 		hsNotice(rb, client.t("An error occurred"))
 	} else if vhost != "" {
@@ -402,9 +391,10 @@ func hsOfferListHandler(server *Server, client *Client, command string, params [
 }
 
 func hsTakeHandler(server *Server, client *Client, command string, params []string, rb *ResponseBuffer) {
+	config := server.Config()
 	vhost := params[0]
 	found := false
-	for _, offered := range server.Config().Accounts.VHosts.OfferList {
+	for _, offered := range config.Accounts.VHosts.OfferList {
 		if offered == vhost {
 			found = true
 		}
@@ -414,9 +404,13 @@ func hsTakeHandler(server *Server, client *Client, command string, params []stri
 		return
 	}
 
-	_, err := server.accounts.VHostSet(client.Account(), vhost)
+	_, err := server.accounts.VHostSet(client.Account(), vhost, config.Accounts.VHosts.UserRequests.Cooldown)
 	if err != nil {
-		hsNotice(rb, client.t("An error occurred"))
+		if throttled, ok := err.(*vhostThrottleExceeded); ok {
+			hsNotice(rb, fmt.Sprintf(client.t("You must wait an additional %v before taking a vhost"), throttled.timeRemaining))
+		} else {
+			hsNotice(rb, client.t("An error occurred"))
+		}
 	} else if vhost != "" {
 		hsNotice(rb, client.t("Successfully set vhost"))
 	} else {