From: Alexander Barton <alex@barton.de>
Date: Mon, 16 Jan 2012 10:43:22 +0000 (+0100)
Subject: Implement user mode 'C': require "same channel" to send message
X-Git-Tag: rel-19-rc1~30
X-Git-Url: https://arthur.barton.de/cgi-bin/gitweb.cgi?p=ngircd-alex.git;a=commitdiff_plain;h=1f4711a5474d2f0ea4664bd9b54f036af11f96cd;hp=4d0069c3a8021c32b5bdeeec57f1d41d369587ce

Implement user mode 'C': require "same channel" to send message

If the target user of a PRIVMSG or NOTICE command has the user mode 'C'
set, it is required that both sender and receiver are on the same channel.

This prevents private flooding by completely unknown clients.
---

diff --git a/doc/Modes.txt b/doc/Modes.txt
index 20e927b6..0b0e488f 100644
--- a/doc/Modes.txt
+++ b/doc/Modes.txt
@@ -23,6 +23,7 @@ channels he is using at the moment.
 
   a	0.3.0	User is away.
   c	17	IRC operator wants to receive connect/disconnect NOTICEs.
+  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.
   r	0.0.1	User is restricted.
diff --git a/src/ngircd/defines.h b/src/ngircd/defines.h
index e7a14ef8..9dc5e92d 100644
--- a/src/ngircd/defines.h
+++ b/src/ngircd/defines.h
@@ -158,7 +158,7 @@
 #endif
 
 /** Supported user modes. */
-#define USERMODES "aciorRswx"
+#define USERMODES "acCiorRswx"
 
 /** Supported channel modes. */
 #define CHANMODES "biIklmnoOPRstvz"
diff --git a/src/ngircd/irc-mode.c b/src/ngircd/irc-mode.c
index c85faa04..3dd61e7c 100644
--- a/src/ngircd/irc-mode.c
+++ b/src/ngircd/irc-mode.c
@@ -214,6 +214,7 @@ Client_Mode( CLIENT *Client, REQUEST *Req, CLIENT *Origin, CLIENT *Target )
 		/* Validate modes */
 		x[0] = '\0';
 		switch (*mode_ptr) {
+		case 'C': /* Only messages from clients sharing a channel */
 		case 'i': /* Invisible */
 		case 's': /* Server messages */
 		case 'w': /* Wallops messages */
diff --git a/src/ngircd/irc.c b/src/ngircd/irc.c
index 10e3e456..2b94e33a 100644
--- a/src/ngircd/irc.c
+++ b/src/ngircd/irc.c
@@ -349,6 +349,7 @@ static bool
 Send_Message(CLIENT * Client, REQUEST * Req, int ForceType, bool SendErrors)
 {
 	CLIENT *cl, *from;
+	CL2CHAN *cl2chan;
 	CHANNEL *chan;
 	char *currentTarget = Req->argv[0];
 	char *lastCurrentTarget = NULL;
@@ -485,6 +486,23 @@ Send_Message(CLIENT * Client, REQUEST * Req, int ForceType, bool SendErrors)
 			}
 #endif
 
+			if (Client_HasMode(cl, 'C')) {
+				cl2chan = Channel_FirstChannelOf(cl);
+				while (cl2chan) {
+					chan = Channel_GetChannel(cl2chan);
+					if (Channel_IsMemberOf(chan, from))
+						break;
+					cl2chan = Channel_NextChannelOf(cl, cl2chan);
+				}
+				if (!cl2chan) {
+					if (SendErrors && !IRC_WriteStrClient(
+					    from, ERR_NOTONSAMECHANNEL_MSG,
+					    Client_ID(from), Client_ID(cl)))
+						return DISCONNECTED;
+					goto send_next_target;
+				}
+			}
+
 			if (SendErrors && (Client_Type(Client) != CLIENT_SERVER)
 			    && strchr(Client_Modes(cl), 'a')) {
 				/* Target is away */
@@ -522,6 +540,7 @@ Send_Message(CLIENT * Client, REQUEST * Req, int ForceType, bool SendErrors)
 				return DISCONNECTED;
 		}
 
+	send_next_target:
 		currentTarget = strtok_r(NULL, ",", &lastCurrentTarget);
 		if (currentTarget)
 			Conn_SetPenalty(Client_Conn(Client), 1);
diff --git a/src/ngircd/messages.h b/src/ngircd/messages.h
index 0070e701..6a784fe9 100644
--- a/src/ngircd/messages.h
+++ b/src/ngircd/messages.h
@@ -134,6 +134,7 @@
 #define ERR_CANTKILLSERVER_MSG		"483 %s :You can't kill a server!"
 #define ERR_RESTRICTED_MSG		"484 %s :Your connection is restricted"
 #define ERR_NOOPERHOST_MSG		"491 %s :Not configured for your host"
+#define ERR_NOTONSAMECHANNEL_MSG	"493 %s :You must share a common channel with %s"
 
 #define ERR_UMODEUNKNOWNFLAG_MSG	"501 %s :Unknown mode"
 #define ERR_UMODEUNKNOWNFLAG2_MSG	"501 %s :Unknown mode \"%c%c\""