Rework how guest nicks work.

- Use the config setting as a string template instead of as a prefix.
- Allow users of IRCds that have UIDs to use that as the guest nick.
- Fall back to a UID before killing if a guest nick can not be found.

5 files changed, 65 insertions, 33 deletions

diff --git a/data/nickserv.example.conf b/data/nickserv.example.conf
index a62379053..4d2ef3af8 100644
--- a/data/nickserv.example.conf
+++ b/data/nickserv.example.conf
@@ -203,13 +203,17 @@ module
 	releasetimeout = 1m
 
 	/*
-	 * When a user's nick is forcibly changed to enforce a "nick kill", their new nick will start
-	 * with this value. The rest will be made up of 6 or 7 digits.
-	 * Make sure this is a valid nick and Nicklen+7 is not longer than the allowed Nicklen on your ircd.
+	 * When a user's nick is forcibly changed to enforce nickname protection their new
+	 * nick will be based on this value. Any # in the value will be replaced with a random
+	 * number. If your IRCd has support for unique identifiers you can also set this to an
+	 * empty string to change a user's nick to their unique identifier.
 	 *
-	 * This directive is optional. If not set it defaults to "Guest"
+	 * Make sure this is a valid nick and that it is is not longer than the maximum nick
+	 * length on your IRCd.
+	 *
+	 * This directive is optional. If not set it defaults to "Guest####"
 	 */
-	guestnickprefix = "Guest"
+	guestnick = "Guest####"
 
 	/*
 	 * If set, Anope does not allow ownership of nick names, only ownership of accounts.
diff --git a/include/modules/pseudoclients/nickserv.h b/include/modules/pseudoclients/nickserv.h
index 58cf93bd9..f269537bf 100644
--- a/include/modules/pseudoclients/nickserv.h
+++ b/include/modules/pseudoclients/nickserv.h
@@ -19,4 +19,5 @@ public:
 	virtual void Validate(User *u) = 0;
 	virtual void Collide(User *u, NickAlias *na) = 0;
 	virtual void Release(NickAlias *na) = 0;
+	virtual bool IsGuestNick(const Anope::string &nick) const = 0;
 };
diff --git a/modules/nickserv/nickserv.cpp b/modules/nickserv/nickserv.cpp
index 04dd2e1e2..1328ecea5 100644
--- a/modules/nickserv/nickserv.cpp
+++ b/modules/nickserv/nickserv.cpp
@@ -174,6 +174,24 @@ public:
 		OnShutdown();
 	}
 
+	bool IsGuestNick(const Anope::string &nick) const
+	{
+		const auto guestnick = Config->GetModule(this)->Get<Anope::string>("guestnick", "Guest####");
+		if (guestnick.empty())
+			return false; // No guest nick.
+
+		const auto minlen = std::min(nick.length(), guestnick.length());
+		for (size_t idx = 0; idx < minlen; ++idx)
+		{
+			if (guestnick[idx] == '#' && !isdigit(nick[idx]))
+				return false;
+
+			if (Anope::tolower(guestnick[idx]) != Anope::tolower(nick[idx]))
+				return false;
+		}
+		return true;
+	}
+
 	void Validate(User *u) override
 	{
 		NickAlias *na = NickAlias::Find(u->nick);
@@ -238,30 +256,47 @@ public:
 
 		if (IRCD->CanSVSNick)
 		{
-			unsigned nicklen = IRCD->MaxNick;
-			const Anope::string &guestprefix = Config->GetModule("nickserv")->Get<const Anope::string>("guestnickprefix", "Guest");
-
+			auto guestnickok = false;
 			Anope::string guestnick;
+			for (auto i = 0; i < 10; ++i)
+			{
+				guestnick.clear();
+				for (auto guestnickchr : Config->GetModule(this)->Get<Anope::string>("guestnick", "Guest####").substr(0, IRCD->MaxNick))
+				{
+					if (guestnickchr == '#')
+						guestnick.append(Anope::ToString(abs(Anope::RandomNumber()) % 10));
+					else
+						guestnick.push_back(guestnickchr);
+				}
 
-			int i = 0;
-			do
+				// A guest nick is valid if it is non-empty and is not in use.
+				if (!guestnick.empty() && !User::Find(guestnick, true))
+				{
+					guestnickok = true;
+					break;
+				}
+			}
+
+			// If we can't find a guest nick and the IRCd supports
+			// uids then we should use that as the backup guest
+			// nickname.
+			if (!guestnickok && IRCD->RequiresID)
 			{
-				guestnick = guestprefix + Anope::ToString(static_cast<uint16_t>(Anope::RandomNumber()));
-				if (guestnick.length() > nicklen)
-					guestnick = guestnick.substr(0, nicklen);
+				guestnickok = true;
+				guestnick = u->GetUID();
 			}
-			while (User::Find(guestnick) && i++ < 10);
 
-			if (i == 11)
-				u->Kill(*NickServ, "Services nickname-enforcer kill");
-			else
+			if (guestnickok)
 			{
 				u->SendMessage(*NickServ, _("Your nickname is now being changed to \002%s\002"), guestnick.c_str());
 				IRCD->SendForceNickChange(u, guestnick, Anope::CurTime);
+				return;
 			}
 		}
-		else
-			u->Kill(*NickServ, "Services nickname-enforcer kill");
+
+		// We can't change the user's nickname or we can't find an
+		// acceptable guest nick, give them the boot.
+		u->Kill(*NickServ, "Enforcement of services protected nickname");
 	}
 
 	void Release(NickAlias *na) override
diff --git a/modules/nickserv/ns_group.cpp b/modules/nickserv/ns_group.cpp
index f2a7f33ae..3ccba782c 100644
--- a/modules/nickserv/ns_group.cpp
+++ b/modules/nickserv/ns_group.cpp
@@ -12,6 +12,8 @@
 #include "module.h"
 #include "modules/ns_cert.h"
 
+static ServiceReference<NickServService> nickserv("NickServService", "NickServ");
+
 class NSGroupRequest final
 	: public IdentifyRequest
 {
@@ -142,7 +144,6 @@ public:
 		}
 
 		NickAlias *target, *na = NickAlias::Find(source.GetNick());
-		const Anope::string &guestnick = Config->GetModule("nickserv")->Get<const Anope::string>("guestnickprefix", "Guest");
 		time_t reg_delay = Config->GetModule("nickserv")->Get<time_t>("regdelay");
 		unsigned maxaliases = Config->GetModule(this->owner)->Get<unsigned>("maxaliases");
 		if (!(target = NickAlias::Find(nick)))
@@ -165,12 +166,8 @@ public:
 			source.Reply(NICK_IDENTIFY_REQUIRED);
 		else if (maxaliases && target->nc->aliases->size() >= maxaliases && !target->nc->IsServicesOper())
 			source.Reply(_("There are too many nicks in your group."));
-		else if (source.GetNick().length() <= guestnick.length() + 7 &&
-			source.GetNick().length() >= guestnick.length() + 1 &&
-			!source.GetNick().find_ci(guestnick) && !source.GetNick().substr(guestnick.length()).find_first_not_of("1234567890"))
-		{
+		else if (nickserv && nickserv->IsGuestNick(source.GetNick()))
 			source.Reply(NICK_CANNOT_BE_REGISTERED, source.GetNick().c_str());
-		}
 		else
 		{
 			bool ok = false;
diff --git a/modules/nickserv/ns_register.cpp b/modules/nickserv/ns_register.cpp
index 4775fc594..692371c0e 100644
--- a/modules/nickserv/ns_register.cpp
+++ b/modules/nickserv/ns_register.cpp
@@ -13,6 +13,8 @@
 
 static bool SendRegmail(User *u, const NickAlias *na, BotInfo *bi);
 
+static ServiceReference<NickServService> nickserv("NickServService", "NickServ");
+
 class CommandNSConfirm final
 	: public Command
 {
@@ -133,7 +135,6 @@ public:
 	{
 		User *u = source.GetUser();
 		Anope::string u_nick = source.GetNick();
-		size_t nicklen = u_nick.length();
 		Anope::string pass = params[0];
 		Anope::string email = params.size() > 1 ? params[1] : "";
 		const Anope::string &nsregister = Config->GetModule(this->owner)->Get<const Anope::string>("registration");
@@ -160,13 +161,7 @@ public:
 			return;
 		}
 
-		/* Prevent "Guest" nicks from being registered. -TheShadow */
-
-		/* Guest nick can now have a series of between 1 and 7 digits.
-		 *   --lara
-		 */
-		const Anope::string &guestnick = Config->GetModule("nickserv")->Get<const Anope::string>("guestnickprefix", "Guest");
-		if (nicklen <= guestnick.length() + 7 && nicklen >= guestnick.length() + 1 && !u_nick.find_ci(guestnick) && u_nick.substr(guestnick.length()).find_first_not_of("1234567890") == Anope::string::npos)
+		if (nickserv && nickserv->IsGuestNick(u_nick))
 		{
 			source.Reply(NICK_CANNOT_BE_REGISTERED, u_nick.c_str());
 			return;