From 29705306f21d713c2928d8896f48a3cbb640eacc Mon Sep 17 00:00:00 2001
From: Sadie Powell
Date: Thu, 29 Jun 2023 16:29:56 +0100
Subject: Retain the "real" username properly like we do for hostnames.

This introduces the concept of a real username. This value comes
from either the initial USER message or from an ident lookup. Doing
this allows us to use it for bans through vidents and cloaking web
client users using their remote username.

While changing this I also changed all of the uses of "ident" other
than RFC 1413 lookups and some compatibility cases to refer to
usernames as user(name) instead of ident. Our use of ident in these
places was incorrect as that only refers to the RFC 1413 response
and is not commonly used in the way we used it by any other IRC
server implementations.
---
 src/users.cpp | 70 ++++++++++++++++++++++++++++++++++++++++++++++-------------
 1 file changed, 55 insertions(+), 15 deletions(-)

(limited to 'src/users.cpp')

diff --git a/src/users.cpp b/src/users.cpp
index 4fbe51321..16267a94d 100644
--- a/src/users.cpp
+++ b/src/users.cpp
@@ -129,7 +129,7 @@ const std::string& User::GetUserAddress()
 {
 	if (cached_useraddress.empty())
 	{
-		cached_useraddress = INSP_FORMAT("{}@{}", ident, GetAddress());
+		cached_useraddress = INSP_FORMAT("{}@{}", GetRealUser(), GetAddress());
 		cached_useraddress.shrink_to_fit();
 	}
 
@@ -139,7 +139,7 @@ const std::string& User::GetUserHost()
 {
 	if (cached_userhost.empty())
 	{
-		cached_userhost = INSP_FORMAT("{}@{}", ident, GetDisplayedHost());
+		cached_userhost = INSP_FORMAT("{}@{}", GetDisplayedUser(), GetDisplayedHost());
 		cached_userhost.shrink_to_fit();
 	}
 
@@ -150,7 +150,7 @@ const std::string& User::GetRealUserHost()
 {
 	if (cached_realuserhost.empty())
 	{
-		cached_realuserhost = INSP_FORMAT("{}@{}", ident, GetRealHost());
+		cached_realuserhost = INSP_FORMAT("{}@{}", GetRealUser(), GetRealHost());
 		cached_realuserhost.shrink_to_fit();
 	}
 
@@ -161,7 +161,7 @@ const std::string& User::GetMask()
 {
 	if (cached_mask.empty())
 	{
-		cached_mask = INSP_FORMAT("{}!{}@{}", nick, ident, GetDisplayedHost());
+		cached_mask = INSP_FORMAT("{}!{}@{}", nick, GetDisplayedUser(), GetDisplayedHost());
 		cached_mask.shrink_to_fit();
 	}
 
@@ -172,7 +172,7 @@ const std::string& User::GetRealMask()
 {
 	if (cached_realmask.empty())
 	{
-		cached_realmask = INSP_FORMAT("{}!{}@{}", nick, ident, GetRealHost());
+		cached_realmask = INSP_FORMAT("{}!{}@{}", nick, GetRealUser(), GetRealHost());
 		cached_realmask.shrink_to_fit();
 	}
 
@@ -190,9 +190,9 @@ LocalUser::LocalUser(int myfd, const irc::sockets::sockaddrs& clientsa, const ir
 	signon = ServerInstance->Time();
 	// The user's default nick is their UUID
 	nick = uuid;
-	ident = uuid;
 	eh.SetFd(myfd);
 	memcpy(&client_sa, &clientsa, sizeof(irc::sockets::sockaddrs));
+	ChangeRealUser(uuid, true);
 	ChangeRealHost(GetAddress(), true);
 }
 
@@ -593,10 +593,10 @@ void LocalUser::OverruleNick()
 	this->ChangeNick(this->uuid);
 }
 
-const std::string& User::GetBanIdent() const
+const std::string& User::GetBanUser(bool real) const
 {
 	static const std::string wildcard = "*";
-	return uniqueusername ? ident : wildcard;
+	return uniqueusername ? GetUser(real) : wildcard;
 }
 
 irc::sockets::cidr_mask User::GetCIDRMask() const
@@ -990,20 +990,60 @@ void User::ChangeRealHost(const std::string& host, bool resetdisplay)
 		FOREACH_MOD(OnPostChangeRealHost, (this));
 }
 
-bool User::ChangeIdent(const std::string& newident)
+void User::ChangeRealUser(const std::string& newuser, bool resetdisplay)
 {
-	if (this->ident == newident)
-		return true;
+	// If the real user is the new user and we are not resetting the
+	// display user then we have nothing to do.
+	const bool changeuser = (realuser != newuser);
+	if (!changeuser && !resetdisplay)
+		return;
+
+	// If the displayuser is not set and we are not resetting it then
+	// we need to copy it to the displayuser field.
+	if (displayuser.empty() && !resetdisplay)
+		displayuser = realuser;
 
-	FOREACH_MOD(OnChangeIdent, (this, newident));
+	// If the displayuser is the new user or we are resetting it then
+	// we clear its contents to save memory.
+	else if (displayuser == newuser || resetdisplay)
+		displayuser.clear();
+
+	// If we are just resetting the display user then we don't need to
+	// do anything else.
+	if (!changeuser)
+		return;
+
+	// Don't call the OnChangeRealUser event when initialising a user.
+	const bool initializing = realuser.empty();
+	if (!initializing)
+		FOREACH_MOD(OnChangeRealUser, (this, newuser));
+
+	realuser = newuser;
+	realuser.shrink_to_fit();
 
-	this->ident.assign(newident, 0, ServerInstance->Config->Limits.MaxUser);
-	this->ident.shrink_to_fit();
 	this->InvalidateCache();
 
-	return true;
+	// Don't call the OnPostChangeRealUser event when initialising a user.
+	if (!this->quitting && !initializing)
+		FOREACH_MOD(OnPostChangeRealUser, (this));
 }
 
+bool User::ChangeDisplayedUser(const std::string& newuser)
+{
+	if (GetDisplayedUser() == newuser)
+		return true;
+
+	FOREACH_MOD(OnChangeUser, (this, newuser));
+
+	if (realuser == newuser)
+		this->displayuser.clear();
+	else
+		this->displayuser.assign(newuser, 0, ServerInstance->Config->Limits.MaxUser);
+	this->displayuser.shrink_to_fit();
+
+	this->InvalidateCache();
+	return true;
+}
 
 void User::PurgeEmptyChannels()
 {
-- 
cgit v1.3.1-10-gc9f91