Implement new configuration option "AllowedChannelTypes"

The new configuration variable "AllowedChannelTypes" lists all allowed
channel types (channel prefixes) for newly created channels on the local
server. By default, all supported channel types are allowed.

If set to the empty string, local clients can't create new channels at
all, which equals the old "PredefChannelsOnly = yes" setting.

This patch deprecates the "PredefChannelsOnly" variable, too, but it is
still supported and translated to the apropriate "AllowedChannelTypes"
setting. When "PredefChannelsOnly" is processed, a warning message is
logged.

Closes bug #152.

src/ngircd/conf.c

@@ -391,6 +391,7 @@ Conf_Test( void )
 	puts("");
 
 	puts("[OPTIONS]");
+	printf("  AllowedChannelTypes = %s\n", Conf_AllowedChannelTypes);
 	printf("  AllowRemoteOper = %s\n", yesno_to_str(Conf_AllowRemoteOper));
 	printf("  ChrootDir = %s\n", Conf_Chroot);
 	printf("  CloakHost = %s\n", Conf_CloakHost);
@@ -415,7 +416,6 @@ Conf_Test( void )
 	printf("  PAM = %s\n", yesno_to_str(Conf_PAM));
 	printf("  PAMIsOptional = %s\n", yesno_to_str(Conf_PAMIsOptional));
 #endif
-	printf("  PredefChannelsOnly = %s\n", yesno_to_str(Conf_PredefChannelsOnly));
 #ifndef STRICT_RFC
 	printf("  RequireAuthPing = %s\n", yesno_to_str(Conf_AuthPing));
 #endif
@@ -758,6 +758,8 @@ Set_Defaults(bool InitServers)
 	Conf_PongTimeout = 20;
 
 	/* Options */
+	strlcpy(Conf_AllowedChannelTypes, CHANTYPES,
+		sizeof(Conf_AllowedChannelTypes));
 	Conf_AllowRemoteOper = false;
 #ifndef STRICT_RFC
 	Conf_AuthPing = false;
@@ -792,7 +794,6 @@ Set_Defaults(bool InitServers)
 	Conf_PAM = false;
 #endif
 	Conf_PAMIsOptional = false;
-	Conf_PredefChannelsOnly = false;
 #ifdef SYSLOG
 	Conf_ScrubCTCP = false;
 #ifdef LOG_LOCAL5
@@ -1633,12 +1634,37 @@ static void
 Handle_OPTIONS(const char *File, int Line, char *Var, char *Arg)
 {
 	size_t len;
+	char *p;
 
 	assert(File != NULL);
 	assert(Line > 0);
 	assert(Var != NULL);
 	assert(Arg != NULL);
 
+	if (strcasecmp(Var, "AllowedChannelTypes") == 0) {
+		p = Arg;
+		Conf_AllowedChannelTypes[0] = '\0';
+		while (*p) {
+			if (strchr(Conf_AllowedChannelTypes, *p)) {
+				/* Prefix is already included; ignore it */
+				p++;
+				continue;
+			}
+
+			if (strchr(CHANTYPES, *p)) {
+				len = strlen(Conf_AllowedChannelTypes) + 1;
+				assert(len < sizeof(Conf_AllowedChannelTypes));
+				Conf_AllowedChannelTypes[len - 1] = *p;
+				Conf_AllowedChannelTypes[len] = '\0';
+			} else {
+				Config_Error(LOG_WARNING,
+					     "%s, line %d: Unknown channel prefix \"%c\" in \"AllowedChannelTypes\"!",
+					     File, Line, *p);
+			}
+			p++;
+		}
+		return;
+	}
 	if (strcasecmp(Var, "AllowRemoteOper") == 0) {
 		Conf_AllowRemoteOper = Check_ArgIsTrue(Arg);
 		return;
@@ -1731,7 +1757,19 @@ Handle_OPTIONS(const char *File, int Line, char *Var, char *Arg)
 		return;
 	}
 	if (strcasecmp(Var, "PredefChannelsOnly") == 0) {
-		Conf_PredefChannelsOnly = Check_ArgIsTrue(Arg);
+		/*
+		 * TODO: This section and support for "PredefChannelsOnly"
+		 * could be removed starting with ngIRCd release 22 (one
+		 * release after marking it "deprecated") ...
+		 */
+		Config_Error(LOG_WARNING,
+			     "%s, line %d (section \"Options\"): \"%s\" is deprecated, please use \"AllowedChannelTypes\"!",
+			     File, Line, Var);
+		if (Check_ArgIsTrue(Arg))
+			Conf_AllowedChannelTypes[0] = '\0';
+		else
+			strlcpy(Conf_AllowedChannelTypes, CHANTYPES,
+				sizeof(Conf_AllowedChannelTypes));
 		return;
 	}
 #ifndef STRICT_RFC

src/ngircd/conf.h

@@ -148,8 +148,8 @@ GLOBAL CONF_SERVER Conf_Server[MAX_SERVERS];
 /** Array of pre-defined channels */
 GLOBAL array Conf_Channels;
 
-/** Flag indicating if only pre-defined channels are allowed (true) or not */
-GLOBAL bool Conf_PredefChannelsOnly;
+/** String containing all locally allowed channel prefixes for new channels */
+GLOBAL char Conf_AllowedChannelTypes[8];
 
 /** Flag indicating if IRC operators are allowed to always use MODE (true) */
 GLOBAL bool Conf_OperCanMode;

src/ngircd/irc-channel.c

@@ -344,7 +344,7 @@ IRC_JOIN( CLIENT *Client, REQUEST *Req )
 		}
 
 		chan = Channel_Search(channame);
-		if (!chan && Conf_PredefChannelsOnly) {
+		if (!chan && !strchr(Conf_AllowedChannelTypes, channame[0])) {
 			 /* channel must be created, but forbidden by config */
 			IRC_WriteStrClient(Client, ERR_NOSUCHCHANNEL_MSG,
 					   Client_ID(Client), channame);