From d3ae351236e605b400b94fcfa8e7670e26e19c89 Mon Sep 17 00:00:00 2001
From: Alexander Barton <alex@barton.de>
Date: Sat, 6 Oct 2012 18:13:01 +0200
Subject: [PATCH] Implement channel mode "Q" and user mode "q"

Both modes protect users from channel kicks: only IRC operators and
servers can kick users having mode "q" or in channels with mode "Q".

Original patch by DNS777 <dns@rbose.org>, thanks!

This closes bug #141.
---
 doc/Modes.txt         |  2 ++
 src/ngircd/channel.c  | 11 +++++++++++
 src/ngircd/defines.h  |  4 ++--
 src/ngircd/irc-mode.c | 10 ++++++++++
 src/ngircd/messages.h |  3 ++-
 5 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/doc/Modes.txt b/doc/Modes.txt
index e3b754d6..fb784511 100644
--- a/doc/Modes.txt
+++ b/doc/Modes.txt
@@ -27,6 +27,7 @@ channels he is using at the moment.
   C	19	Only users that share a channel are allowed to send messages.
   i	0.0.1	User is "invisible".
   o	0.0.1	User is IRC operator.
+  q	20	User is protected, can not be kicked from a channel.
   r	0.0.1	User is restricted.
   R (1)	19	User is registered (e.g. by NickServ).
   s	0.4.0	User wants to receive server notices.
@@ -54,6 +55,7 @@ users to lists (e.g. "invite list", "ban list"), others have parameters
   n	0.3.0	Channel doesn't allow messages of users not being members.
   O	18	Only IRC operators are allowed to join this channel.
   P	0.5.0	Channel is "persistent".
+  Q	20	Nobody can be kicked from the channel.
   r (1)	19	Channel is "registered" (e.g. by ChanServ).
   R	19	Only registered users are allowed to join this channel.
   s	0.9.0	Channel is "secret".
diff --git a/src/ngircd/channel.c b/src/ngircd/channel.c
index 10b05405..c679daeb 100644
--- a/src/ngircd/channel.c
+++ b/src/ngircd/channel.c
@@ -327,6 +327,17 @@ Channel_Kick(CLIENT *Peer, CLIENT *Target, CLIENT *Origin, const char *Name,
 	}
 
 	if(Client_Type(Peer) == CLIENT_USER) {
+		/* Channel mode 'Q' and user mode 'q' on target: nobody but
+		 * IRC Operators and servers can kick the target user */
+		if ((strchr(Channel_Modes(chan), 'Q')
+		    || Client_HasMode(Target, 'q'))
+		    && !Client_HasMode(Origin, 'o')) {
+			IRC_WriteStrClient(Origin, ERR_KICKDENY_MSG,
+					   Client_ID(Origin), Name,
+					   Client_ID(Target));
+			return;
+		}
+
 		/* Check if client has the rights to kick target */
 		ptr = Channel_UserModes(chan, Peer);
 		target_modes = Channel_UserModes(chan, Target);
diff --git a/src/ngircd/defines.h b/src/ngircd/defines.h
index ba7adf17..c0be813a 100644
--- a/src/ngircd/defines.h
+++ b/src/ngircd/defines.h
@@ -161,10 +161,10 @@
 #endif
 
 /** Supported user modes. */
-#define USERMODES "aBcCiorRswx"
+#define USERMODES "aBcCioqrRswx"
 
 /** Supported channel modes. */
-#define CHANMODES "abehiIklmMnoOPqrRstvz"
+#define CHANMODES "abehiIklmMnoOPqQrRstvz"
 
 /** Away message for users connected to linked servers. */
 #define DEFAULT_AWAY_MSG "Away"
diff --git a/src/ngircd/irc-mode.c b/src/ngircd/irc-mode.c
index 90f638d8..7f04e9c5 100644
--- a/src/ngircd/irc-mode.c
+++ b/src/ngircd/irc-mode.c
@@ -257,6 +257,15 @@ Client_Mode( CLIENT *Client, REQUEST *Req, CLIENT *Origin, CLIENT *Target )
 							ERR_NOPRIVILEGES_MSG,
 							Client_ID(Origin));
 			break;
+		case 'q': /* KICK-protected user */
+			if (!set || Client_Type(Client) == CLIENT_SERVER
+			    || Client_OperByMe(Origin))
+				x[0] = 'q';
+			else
+				ok = IRC_WriteStrClient(Origin,
+							ERR_NOPRIVILEGES_MSG,
+							Client_ID(Origin));
+			break;
 		case 'r': /* Restricted (only settable) */
 			if (set || Client_Type(Client) == CLIENT_SERVER)
 				x[0] = 'r';
@@ -569,6 +578,7 @@ Channel_Mode(CLIENT *Client, REQUEST *Req, CLIENT *Origin, CHANNEL *Channel)
 		case 'M': /* Only identified nicks can write */
 		case 'm': /* Moderated */
 		case 'n': /* Only members can write */
+		case 'Q': /* No kicks */
 		case 't': /* Topic locked */
 			if(is_oper || is_machine || is_owner ||
 			   is_admin || is_op || is_halfop)
diff --git a/src/ngircd/messages.h b/src/ngircd/messages.h
index efc7524e..ea24b2eb 100644
--- a/src/ngircd/messages.h
+++ b/src/ngircd/messages.h
@@ -21,7 +21,7 @@
 #define RPL_YOURHOST_MSG		"002 %s :Your host is %s, running version ngircd-%s (%s/%s/%s)"
 #define RPL_CREATED_MSG			"003 %s :This server has been started %s"
 #define RPL_MYINFO_MSG			"004 %s %s ngircd-%s %s %s"
-#define RPL_ISUPPORT1_MSG		"005 %s RFC2812 IRCD=ngIRCd CASEMAPPING=ascii PREFIX=(qaohv)~&@%%+ CHANTYPES=#&+ CHANMODES=beI,k,l,imMnOPRstz CHANLIMIT=#&+:%d :are supported on this server"
+#define RPL_ISUPPORT1_MSG		"005 %s RFC2812 IRCD=ngIRCd CASEMAPPING=ascii PREFIX=(qaohv)~&@%%+ CHANTYPES=#&+ CHANMODES=beI,k,l,imMnOPQRstz CHANLIMIT=#&+:%d :are supported on this server"
 #define RPL_ISUPPORT2_MSG		"005 %s CHANNELLEN=%d NICKLEN=%d TOPICLEN=%d AWAYLEN=%d KICKLEN=%d MODES=%d MAXLIST=beI:%d EXCEPTS=e INVEX=I PENALTY :are supported on this server"
 
 #define RPL_TRACELINK_MSG		"200 %s Link %s-%s %s %s V%s %ld %d %d"
@@ -140,6 +140,7 @@
 #define ERR_NOPRIVILEGES_MSG		"481 %s :Permission denied"
 #define ERR_CHANOPRIVSNEEDED_MSG	"482 %s %s :You are not channel operator"
 #define ERR_CHANOPPRIVTOOLOW_MSG	"482 %s %s :Your privileges are too low"
+#define ERR_KICKDENY_MSG		"482 %s %s :Cannot kick, %s is protected"
 #define ERR_CANTKILLSERVER_MSG		"483 %s :You can't kill a server!"
 #define ERR_RESTRICTED_MSG		"484 %s :Your connection is restricted"
 #define ERR_NICKREGISTER_MSG		"484 %s :Cannot modify user mode (+R) -- Use IRC services"