Limit channel invite and ban lists to 50 entries

 - New function Lists_Count().
 - New limit #define MAX_HNDL_CHANNEL_LISTS = 50.
 - New numeric #define ERR_LISTFULL_MSG(478).
 - Adjust numeric RPL_ISUPPORT2_MSG(005) accordingly ("MAXLIST")

6 files changed, 36 insertions, 2 deletions

diff --git a/src/ngircd/defines.h b/src/ngircd/defines.h
index e7586681..e7a14ef8 100644
--- a/src/ngircd/defines.h
+++ b/src/ngircd/defines.h
@@ -181,6 +181,9 @@
 /** Max. number of LIST replies. */
 #define MAX_RPL_LIST 100
 
+/** Max. number of elemets allowed in channel invite and ban lists. */
+#define MAX_HNDL_CHANNEL_LISTS 50
+
 /** Max. number of channel modes with arguments per MODE command. */
 #define MAX_HNDL_MODES_ARG 5
 
diff --git a/src/ngircd/irc-info.c b/src/ngircd/irc-info.c
index fd4cbee4..24f25afe 100644
--- a/src/ngircd/irc-info.c
+++ b/src/ngircd/irc-info.c
@@ -1583,7 +1583,8 @@ IRC_Send_ISUPPORT(CLIENT * Client)
 	return IRC_WriteStrClient(Client, RPL_ISUPPORT2_MSG, Client_ID(Client),
 				  CHANNEL_NAME_LEN - 1, Conf_MaxNickLength - 1,
 				  COMMAND_LEN - 23, CLIENT_AWAY_LEN - 1,
-				  COMMAND_LEN - 113, MAX_HNDL_MODES_ARG);
+				  COMMAND_LEN - 113, MAX_HNDL_MODES_ARG,
+				  MAX_HNDL_CHANNEL_LISTS);
 } /* IRC_Send_ISUPPORT */
 
 
diff --git a/src/ngircd/irc-mode.c b/src/ngircd/irc-mode.c
index bb78bcb6..c85faa04 100644
--- a/src/ngircd/irc-mode.c
+++ b/src/ngircd/irc-mode.c
@@ -863,6 +863,12 @@ Add_Ban_Invite(char what, CLIENT *Prefix, CLIENT *Client, CHANNEL *Channel,
 
 	if (Lists_CheckDupeMask(list, mask))
 		return CONNECTED;
+	if (Client_Type(Client) == CLIENT_USER &&
+	    Lists_Count(list) >= MAX_HNDL_CHANNEL_LISTS)
+		return IRC_WriteStrClient(Client, ERR_LISTFULL_MSG,
+					  Client_ID(Client),
+					  Channel_Name(Channel), mask,
+					  MAX_HNDL_CHANNEL_LISTS);
 
 	if (what == 'I') {
 		if (!Channel_AddInvite(Channel, mask, false))
diff --git a/src/ngircd/lists.c b/src/ngircd/lists.c
index fd86f301..c082f1c4 100644
--- a/src/ngircd/lists.c
+++ b/src/ngircd/lists.c
@@ -385,4 +385,26 @@ Lists_Expire(struct list_head *h, const char *ListName)
 	}
 }
 
+/**
+ * Return the number of entries of a list.
+ *
+ * @param h List head.
+ * @return Number of items.
+ */
+GLOBAL unsigned long
+Lists_Count(struct list_head *h)
+{
+	struct list_elem *e;
+	unsigned long count = 0;
+
+	assert(h != NULL);
+
+	e = h->first;
+	while (e) {
+		count++;
+		e = e->next;
+	}
+	return count;
+}
+
 /* -eof- */
diff --git a/src/ngircd/lists.h b/src/ngircd/lists.h
index d0b4d819..cb2e2c1a 100644
--- a/src/ngircd/lists.h
+++ b/src/ngircd/lists.h
@@ -36,6 +36,7 @@ GLOBAL struct list_elem *Lists_CheckDupeMask PARAMS((const struct list_head *hea
 GLOBAL bool Lists_Add PARAMS((struct list_head *h, const char *Mask,
 			      time_t ValidUntil, const char *Reason));
 GLOBAL void Lists_Del PARAMS((struct list_head *head, const char *Mask));
+GLOBAL unsigned long Lists_Count PARAMS((struct list_head *h));
 
 GLOBAL void Lists_Free PARAMS((struct list_head *head));
 
diff --git a/src/ngircd/messages.h b/src/ngircd/messages.h
index 761e36df..c5d83367 100644
--- a/src/ngircd/messages.h
+++ b/src/ngircd/messages.h
@@ -22,7 +22,7 @@
 #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=(ov)@+ CHANTYPES=#&+ CHANMODES=bI,k,l,imnOPRstz 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 PENALTY :are supported on this server"
+#define RPL_ISUPPORT2_MSG		"005 %s CHANNELLEN=%d NICKLEN=%d TOPICLEN=%d AWAYLEN=%d KICKLEN=%d MODES=%d MAXLIST=bI:%d PENALTY :are supported on this server"
 
 #define RPL_TRACELINK_MSG		"200 %s Link %s-%s %s %s V%s %ld %d %d"
 #define RPL_TRACEOPERATOR_MSG		"204 %s Oper 2 :%s"
@@ -127,6 +127,7 @@
 #define ERR_BANNEDFROMCHAN_MSG		"474 %s %s :Cannot join channel (+b)"
 #define ERR_BADCHANNELKEY_MSG		"475 %s %s :Cannot join channel (+k)"
 #define ERR_NOCHANMODES_MSG		"477 %s %s :Channel doesn't support modes"
+#define ERR_LISTFULL_MSG		"478 %s %s %s: Channel list is full (%d)"
 #define ERR_NOPRIVILEGES_MSG		"481 %s :Permission denied"
 #define ERR_CHANOPRIVSNEEDED_MSG	"482 %s %s :You are not channel operator"
 #define ERR_CANTKILLSERVER_MSG		"483 %s :You can't kill a server!"