Add set::allow-setident (default: 'no'), set::allow-setname ('yes')

Two new settings that control the use of `SETIDENT` and `SETNAME`:
* [set::allow-setident](https://www.unrealircd.org/docs/Set_block#set::allow-setident)
  now defaults to 'no'. Previously all users were allowed to change their
  ident (taking into account
  [set::allow-userhost-change](https://www.unrealircd.org/docs/Set_block#set::allow-userhost-change)
  restrictions).
* [set::allow-setname])(https://www.unrealircd.org/docs/Set_block#set::allow-setname)
  has a default of 'yes' which matches older UnrealIRCd versions (no change).
  Perhaps some admins who use controlled (web)chats may want to set this
  to 'no' if users are not supposed to change their realname/gecos.
  This is probably rare, but they have the option now.

doc/RELEASE-NOTES.md

@@ -18,14 +18,25 @@ This version comes with a few enhancements and has quite a number of bugfixes.
   have not even send a message yet.
 * The [module manager](https://www.unrealircd.org/docs/Module_manager)
   now allows 3rd party modules to specify external libraries and build flags.
+* Two new settings that control the use of `SETIDENT` and `SETNAME`:
+  * [set::allow-setident](https://www.unrealircd.org/docs/Set_block#set::allow-setident)
+    now defaults to 'no'. Previously all users were allowed to change their
+    ident (taking into account
+    [set::allow-userhost-change](https://www.unrealircd.org/docs/Set_block#set::allow-userhost-change)
+    restrictions).
+  * [set::allow-setname])(https://www.unrealircd.org/docs/Set_block#set::allow-setname)
+    has a default of 'yes' which matches older UnrealIRCd versions (no change).
+    Perhaps some admins who use controlled (web)chats may want to set this
+    to 'no' if users are not supposed to change their realname/gecos.
+    This is probably rare, but they have the option now.
 
 ### Changes:
-* Small updates to `HELPOP`.
 * `./unrealircd module install` now gives a non-zero exit code on failure
 * If SASL authentication is ongoing and a client sends `CAP END`, we now wait for
   SASL to succeed/fail/timeout before actually ending the handshake. This solves
   a race condition for IRC clients that don't follow the recommendation in the
   [sasl specification](https://ircv3.net/specs/extensions/sasl-3.1#the-authenticate-command).
+* Small updates to `HELPOP`.
 * Slightly raise default
   [set::handshake-timeout](https://www.unrealircd.org/docs/Set_block#set::handshake-timeout)
   from 30 to 40 seconds.

include/dynconf.h

@@ -102,6 +102,8 @@ struct Configuration {
 	char *outdated_tls_policy_oper_message;
 	Policy outdated_tls_policy_server;
 	enum UHAllowed userhost_allowed;
+	int allow_setident;
+	int allow_setname;
 	char *restrict_channelmodes;
 	int named_extended_bans;
 	char *channel_command_prefix;
@@ -327,6 +329,8 @@ struct SetCheck {
 	unsigned has_maxdccallow:1;
 	unsigned has_anti_spam_quit_message_time:1;
 	unsigned has_allow_userhost_change:1;
+	unsigned has_allow_setident:1;
+	unsigned has_allow_setname:1;
 	unsigned has_restrict_channelmodes:1;
 	unsigned has_channel_command_prefix:1;
 	unsigned has_modes_on_join:1;

src/conf.c

@@ -1842,6 +1842,8 @@ void config_setdefaultsettings(Configuration *i)
 	i->dns_dnsbl_timeout = DNS_DEFAULT_DNSBL_TIMEOUT;
 	i->dns_dnsbl_retry = DNS_DEFAULT_DNSBL_RETRIES;
 	i->send_isupport_updates = 0; /* Off for now, will be turned on by default later after more testing */
+	i->allow_setident = 0;
+	i->allow_setname = 1;
 }
 
 /* Some settings have been moved to here - we (re)set some defaults */
@@ -7808,6 +7810,12 @@ int	_conf_set(ConfigFile *conf, ConfigEntry *ce)
 			else
 				tempiConf.userhost_allowed = UHALLOW_REJOIN;
 		}
+		else if (!strcmp(cep->name, "allow-setident")) {
+			tempiConf.allow_setident = config_checkval(cep->value, CFG_YESNO);
+		}
+		else if (!strcmp(cep->name, "allow-setname")) {
+			tempiConf.allow_setname = config_checkval(cep->value, CFG_YESNO);
+		}
 		else if (!strcmp(cep->name, "channel-command-prefix")) {
 			safe_strdup(tempiConf.channel_command_prefix, cep->value);
 		}
@@ -8567,6 +8575,14 @@ int	_test_set(ConfigFile *conf, ConfigEntry *ce)
 				continue;
 			}
 		}
+		else if (!strcmp(cep->name, "allow-setident")) {
+			CheckNull(cep);
+			CheckDuplicate(cep, allow_setident, "allow-setident");
+		}
+		else if (!strcmp(cep->name, "allow-setname")) {
+			CheckNull(cep);
+			CheckDuplicate(cep, allow_setname, "allow-setname");
+		}
 		else if (!strcmp(cep->name, "anti-spam-quit-message-time")) {
 			CheckNull(cep);
 			CheckDuplicate(cep, anti_spam_quit_message_time, "anti-spam-quit-message-time");

src/modules/setident.c

@@ -63,6 +63,12 @@ CMD_FUNC(cmd_setident)
 {
 	const char *vident, *s;
 
+	if (MyUser(client) && !iConf.allow_setident && !IsOper(client))
+	{
+		sendnumeric(client, ERR_NOPRIVILEGES);
+		return;
+	}
+
 	if ((parc < 2) || BadPtr(parv[1]))
 	{
 		if (MyConnect(client))

src/modules/setname.c

@@ -89,6 +89,12 @@ CMD_FUNC(cmd_setname)
 	ConfigItem_ban *bconf;
 	MessageTag *mtags = NULL;
 
+	if (MyUser(client) && !iConf.allow_setname && !IsOper(client))
+	{
+		sendnumeric(client, ERR_NOPRIVILEGES);
+		return;
+	}
+
 	if ((parc < 2) || BadPtr(parv[1]))
 	{
 		sendnumeric(client, ERR_NEEDMOREPARAMS, "SETNAME");