m_shedding: user shedding module based on oftc-hybrid

doc/reference.conf

@@ -479,6 +479,7 @@ privset "local_op" {
 	 * usermode:helpops      allows setting +h (from extensions/helpops)
 	 * auspex:usertimes:
 	 *   allows viewing user idle/connect times even when +I is set (from extensions/umode_hide_idle_time)
+	 * oper:shedding:	allows the SHEDDING command (from extensions/m_shedding)
 	 */
 	privs = oper:general, oper:privs, oper:testline, oper:kill, oper:operwall, oper:message,
 		usermode:servnotice, auspex:oper, auspex:hostname, auspex:umodes, auspex:cmodes;

extensions/Makefile.am

@@ -55,6 +55,7 @@ extension_LTLIBRARIES =		\
   m_omode.la			\
   m_opme.la			\
   m_sendbans.la			\
+  m_shedding.la			\
   m_webirc.la			\
   m_remove.la			\
   hide_uncommon_channels.la	\

extensions/m_shedding.c

@@ -0,0 +1,176 @@
+/*
+ *  Solanum: a slightly advanced ircd
+ *  shedding.c: Enables/disables user shedding.
+ *
+ *  Based on oftc-hybrid's m_shedding.c
+ *
+ *  Copyright (C) 2021 David Schultz <me@zpld.me>
+ *  Copyright (C) 2002 by the past and present ircd coders, and others.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
+ *  USA
+ *
+ *
+ */
+
+#include "stdinc.h"
+#include "modules.h"
+#include "hook.h"
+#include "client.h"
+#include "ircd.h"
+#include "send.h"
+#include "s_conf.h"
+#include "s_serv.h"
+#include "s_newconf.h"
+#include "messages.h"
+#include "numeric.h"
+
+#define SHED_RATE_MIN 5
+
+static struct ev_entry *user_shedding_ev = NULL;
+
+static const char shed_desc[] = "Enables/disables user shedding.";
+
+static void mo_shedding(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_p, int parc, const char *parv[]);
+static void me_shedding(struct MsgBuf *msgbuf, struct Client *client_p, struct Client *source_p, int parc, const char *parv[]);
+static void do_user_shedding(void *unused);
+
+static struct Message shedding_msgtab = {
+	"SHEDDING", 0, 0, 0, 0,
+	{mg_unreg, mg_not_oper, mg_ignore, mg_ignore, {me_shedding, 2}, {mo_shedding, 3}}
+};
+
+mapi_clist_av1 shedding_clist[] = { &shedding_msgtab, NULL };
+
+static void
+moddeinit(void)
+{
+	rb_event_delete(user_shedding_ev);
+}
+
+DECLARE_MODULE_AV2(shed, NULL, moddeinit, shedding_clist, NULL, NULL, NULL, NULL, shed_desc);
+
+static void
+set_shedding_state(struct Client *source_p, const char *chr, const char *reason)
+{
+	int rate;
+	if (irccmp(chr, "OFF") == 0)
+	{
+		// disable shedding
+		sendto_realops_snomask(SNO_GENERAL, L_ALL | L_NETWIDE, "%s disabled user shedding", get_oper_name(source_p));
+		rb_event_delete(user_shedding_ev);
+		user_shedding_ev = NULL;
+		return;
+	}
+
+	rate = atoi(chr);
+
+	if(rate < SHED_RATE_MIN)
+	{
+		sendto_one_notice(source_p, "Shedding rate must be at least %d", SHED_RATE_MIN);
+		return;
+	}
+
+	sendto_realops_snomask(SNO_GENERAL, L_ALL | L_NETWIDE, "%s enabled user shedding (interval: %d seconds, reason: %s)",
+	get_oper_name(source_p), rate, reason);
+
+	rb_event_delete(user_shedding_ev);
+	user_shedding_ev = NULL;
+	user_shedding_ev = rb_event_add("user shedding event", do_user_shedding, NULL, rate);
+}
+
+/*
+ * mo_shedding
+ *
+ * inputs - pointer to server
+ *    - pointer to client
+ *    - parameter count
+ *    - parameter list
+ * output -
+ * side effects - user shedding is enabled or disabled
+ *
+ * SHEDDING <server> OFF - disable shedding
+ * SHEDDING <server> <approx_seconds_per_userdrop> :<reason>
+ * (parv[#] 1        2                             3)
+ *
+ */
+static void
+mo_shedding(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_p, int parc, const char *parv[])
+{
+	if (!HasPrivilege(source_p, "oper:shedding"))
+	{
+		sendto_one(source_p, form_str(ERR_NOPRIVS), me.name, source_p->name, "SHEDDING");
+		return;
+	}
+
+	/* I can think of a thousand ways this could go wrong... */
+	if (strchr(parv[1], '*') != NULL)
+	{
+		sendto_one_notice(source_p, "Wildcards are not permitted for shedding targets");
+		return;
+	}
+
+	if (parc != 4 && !(parc == 3 && irccmp(parv[2], "OFF") == 0))
+	{
+		sendto_one(source_p, form_str(ERR_NEEDMOREPARAMS),
+			me.name, source_p->name, "SHEDDING");
+		return;
+	}
+
+	if (irccmp(parv[1], me.name) != 0) {
+		/* it's not for us, pass it around */
+		if (irccmp(parv[2], "OFF") == 0)
+			sendto_match_servs(source_p, parv[1],
+				CAP_ENCAP, NOCAPS,
+				"ENCAP %s SHEDDING OFF", parv[1]);
+		else
+			sendto_match_servs(source_p, parv[1],
+				CAP_ENCAP, NOCAPS,
+				"ENCAP %s SHEDDING %s :%s",
+				parv[1], parv[2], parv[3]);
+		return;
+	}
+
+	set_shedding_state(source_p, parv[2], parv[3]);
+}
+
+static void
+me_shedding(struct MsgBuf *msgbuf, struct Client *client_p, struct Client *source_p, int parc, const char *parv[])
+{
+	if(!IsPerson(source_p))
+		return;
+
+	set_shedding_state(source_p, parv[1], parv[2]);
+}
+
+
+static void
+do_user_shedding(void *unused)
+{
+	rb_dlink_node *ptr;
+	struct Client *client_p;
+
+	RB_DLINK_FOREACH_PREV(ptr, lclient_list.tail)
+	{
+		client_p = ptr->data;
+
+		if (!IsClient(client_p)) /* It could be servers */
+			continue;
+		if (IsExemptKline(client_p))
+			continue;
+		exit_client(client_p, client_p, &me, "Server closed connection");
+		break;
+	}
+}

help/opers/shedding

@@ -0,0 +1,9 @@
+SHEDDING <server> <rate> :<reason>
+SHEDDING <server> OFF
+
+Turns user shedding on or off on the specified server. When a server is
+shedding, a client will be disconnected from the server at a time period
+defined by rate, until shedding is turned off. Clients with kline_exempt
+are never affected by this feature.
+
+- Requires Oper Priv: oper:shedding