Add the ability to SPAMFILTER message-tags.

The new target type is called 'T' and we match against "name=value"
of each message tag (or just "name" if it is without value).

Example: SPAMFILTER ADD -simple T kill 0 this_is_a_test +typing=active
(No this is not a suggestion :D)

This probably won't be used much at all, but it is good to have the
option available in case there is some massive problem,
especially since more message tags may pop up sooner or later.

Caveat: this is actually a bit slow as we may have to check multiple
message tags for a single line.
If there are zero message-tag spamfilters then we will automatically
short-circuit and save all this CPU, which will be the most common case.

doc/conf/help/help.conf

@@ -1405,7 +1405,8 @@ help Spamfilter {
 	" [type]    specifies the target type, you can specify multiple targets:";
 	"           'c' channel msg, 'p' private msg, 'n' private notice,";
 	"           'N' channel notice, 'P' part msg, 'q' quit msg, 'd' dcc,";
-	"           'a' away, 't' topic, 'u' user (nick!user@host:realname ban)";
+	"           'a' away, 't' topic, 'T' message-tag (eg: +typing=active),",
+	"           'u' user (nick!user@host:realname ban)";
 	" [action]  specifies the action to be taken (only 1 action can be specified):";
 	"           'kill', 'tempshun' (only shun current session), 'shun',";
 	"           'kline', 'gline', 'zline', 'gzline', 'block' (blocks the msg),";

include/h.h

@@ -723,7 +723,8 @@ extern MODVAR void (*tkl_stats)(Client *cptr, int type, char *para, int *cnt);
 extern MODVAR void (*tkl_sync)(Client *client);
 extern MODVAR void (*cmd_tkl)(Client *client, MessageTag *recv_mtags, int parc, char *parv[]);
 extern MODVAR int (*place_host_ban)(Client *client, BanAction action, char *reason, long duration);
-extern MODVAR int (*match_spamfilter)(Client *client, char *str_in, int type, char *target, int flags, TKL **rettk);
+extern MODVAR int (*match_spamfilter)(Client *client, char *str_in, int type, char *cmd, char *target, int flags, TKL **rettk);
+extern MODVAR int (*match_spamfilter_mtags)(Client *client, MessageTag *mtags, char *cmd);
 extern MODVAR int (*join_viruschan)(Client *client, TKL *tk, int type);
 extern MODVAR unsigned char *(*StripColors)(unsigned char *text);
 extern MODVAR const char *(*StripControlCodes)(unsigned char *text);

include/modules.h

@@ -2260,6 +2260,7 @@ enum EfunctionType {
 	EFUNC_CMD_TKL,
 	EFUNC_PLACE_HOST_BAN,
 	EFUNC_DOSPAMFILTER,
+	EFUNC_MATCH_SPAMFILTER_MTAGS,
 	EFUNC_DOSPAMFILTER_VIRUSCHAN,
 	EFUNC_FIND_TKLINE_MATCH_ZAP_EX,
 	EFUNC_SEND_LIST,

include/struct.h

@@ -992,12 +992,13 @@ struct Secret {
 #define SPAMF_USERMSG		0x0002 /* p */
 #define SPAMF_USERNOTICE	0x0004 /* n */
 #define SPAMF_CHANNOTICE	0x0008 /* N */
-#define SPAMF_PART			0x0010 /* P */
-#define SPAMF_QUIT			0x0020 /* q */
-#define SPAMF_DCC			0x0040 /* d */
-#define SPAMF_USER			0x0080 /* u */
-#define SPAMF_AWAY			0x0100 /* a */
-#define SPAMF_TOPIC			0x0200 /* t */
+#define SPAMF_PART		0x0010 /* P */
+#define SPAMF_QUIT		0x0020 /* q */
+#define SPAMF_DCC		0x0040 /* d */
+#define SPAMF_USER		0x0080 /* u */
+#define SPAMF_AWAY		0x0100 /* a */
+#define SPAMF_TOPIC		0x0200 /* t */
+#define SPAMF_MTAG		0x0400 /* m */
 
 /* Other flags only for function calls: */
 #define SPAMFLAG_NOWARN		0x0001

src/aliases.c

@@ -66,7 +66,7 @@ void cmd_alias(Client *client, MessageTag *mtags, int parc, char *parv[], char *
 	{
 		if (SERVICES_NAME && (acptr = find_person(alias->nick, NULL)))
 		{
-			if (alias->spamfilter && match_spamfilter(client, parv[1], SPAMF_USERMSG, alias->nick, 0, NULL))
+			if (alias->spamfilter && match_spamfilter(client, parv[1], SPAMF_USERMSG, cmd, alias->nick, 0, NULL))
 				return;
 			sendto_one(acptr, NULL, ":%s PRIVMSG %s@%s :%s", client->name,
 				alias->nick, SERVICES_NAME, parv[1]);
@@ -78,7 +78,7 @@ void cmd_alias(Client *client, MessageTag *mtags, int parc, char *parv[], char *
 	{
 		if (STATS_SERVER && (acptr = find_person(alias->nick, NULL)))
 		{
-			if (alias->spamfilter && match_spamfilter(client, parv[1], SPAMF_USERMSG, alias->nick, 0, NULL))
+			if (alias->spamfilter && match_spamfilter(client, parv[1], SPAMF_USERMSG, cmd, alias->nick, 0, NULL))
 				return;
 			sendto_one(acptr, NULL, ":%s PRIVMSG %s@%s :%s", client->name,
 				alias->nick, STATS_SERVER, parv[1]);
@@ -90,7 +90,7 @@ void cmd_alias(Client *client, MessageTag *mtags, int parc, char *parv[], char *
 	{
 		if ((acptr = find_person(alias->nick, NULL))) 
 		{
-			if (alias->spamfilter && match_spamfilter(client, parv[1], SPAMF_USERMSG, alias->nick, 0, NULL))
+			if (alias->spamfilter && match_spamfilter(client, parv[1], SPAMF_USERMSG, cmd, alias->nick, 0, NULL))
 				return;
 			if (MyUser(acptr))
 				sendto_one(acptr, NULL, ":%s!%s@%s PRIVMSG %s :%s", client->name, 
@@ -112,7 +112,7 @@ void cmd_alias(Client *client, MessageTag *mtags, int parc, char *parv[], char *
 			char *errmsg = NULL;
 			if (can_send_to_channel(client, channel, &msg, &errmsg, 0))
 			{
-				if (alias->spamfilter && match_spamfilter(client, parv[1], SPAMF_CHANMSG, channel->chname, 0, NULL))
+				if (alias->spamfilter && match_spamfilter(client, parv[1], SPAMF_CHANMSG, cmd, channel->chname, 0, NULL))
 					return;
 				new_message(client, NULL, &mtags);
 				sendto_channel(channel, client, client->direction,
@@ -203,7 +203,7 @@ void cmd_alias(Client *client, MessageTag *mtags, int parc, char *parv[], char *
 				{
 					if (SERVICES_NAME && (acptr = find_person(format->nick, NULL)))
 					{
-						if (alias->spamfilter && match_spamfilter(client, output, SPAMF_USERMSG, format->nick, 0, NULL))
+						if (alias->spamfilter && match_spamfilter(client, output, SPAMF_USERMSG, cmd, format->nick, 0, NULL))
 							return;
 						sendto_one(acptr, NULL, ":%s PRIVMSG %s@%s :%s", client->name,
 							format->nick, SERVICES_NAME, output);
@@ -214,7 +214,7 @@ void cmd_alias(Client *client, MessageTag *mtags, int parc, char *parv[], char *
 				{
 					if (STATS_SERVER && (acptr = find_person(format->nick, NULL)))
 					{
-						if (alias->spamfilter && match_spamfilter(client, output, SPAMF_USERMSG, format->nick, 0, NULL))
+						if (alias->spamfilter && match_spamfilter(client, output, SPAMF_USERMSG, cmd, format->nick, 0, NULL))
 							return;
 						sendto_one(acptr, NULL, ":%s PRIVMSG %s@%s :%s", client->name,
 							format->nick, STATS_SERVER, output);
@@ -225,7 +225,7 @@ void cmd_alias(Client *client, MessageTag *mtags, int parc, char *parv[], char *
 				{
 					if ((acptr = find_person(format->nick, NULL))) 
 					{
-						if (alias->spamfilter && match_spamfilter(client, output, SPAMF_USERMSG, format->nick, 0, NULL))
+						if (alias->spamfilter && match_spamfilter(client, output, SPAMF_USERMSG, cmd, format->nick, 0, NULL))
 							return;
 						if (MyUser(acptr))
 							sendto_one(acptr, NULL, ":%s!%s@%s PRIVMSG %s :%s", client->name, 
@@ -247,7 +247,7 @@ void cmd_alias(Client *client, MessageTag *mtags, int parc, char *parv[], char *
 						char *errmsg = NULL;
 						if (!can_send_to_channel(client, channel, &msg, &errmsg, 0))
 						{
-							if (alias->spamfilter && match_spamfilter(client, output, SPAMF_CHANMSG, channel->chname, 0, NULL))
+							if (alias->spamfilter && match_spamfilter(client, output, SPAMF_CHANMSG, cmd, channel->chname, 0, NULL))
 								return;
 							new_message(client, NULL, &mtags);
 							sendto_channel(channel, client, client->direction,

src/api-efunctions.c

@@ -67,7 +67,8 @@ void (*tkl_stats)(Client *client, int type, char *para, int *cnt);
 void (*tkl_sync)(Client *client);
 void (*cmd_tkl)(Client *client, MessageTag *mtags, int parc, char *parv[]);
 int (*place_host_ban)(Client *client, BanAction action, char *reason, long duration);
-int (*match_spamfilter)(Client *client, char *str_in, int type, char *target, int flags, TKL **rettk);
+int (*match_spamfilter)(Client *client, char *str_in, int type, char *cmd, char *target, int flags, TKL **rettk);
+int (*match_spamfilter_mtags)(Client *client, MessageTag *mtags, char *cmd);
 int (*join_viruschan)(Client *client, TKL *tk, int type);
 unsigned char *(*StripColors)(unsigned char *text);
 const char *(*StripControlCodes)(unsigned char *text);
@@ -307,6 +308,7 @@ void efunctions_init(void)
 	efunc_init_function(EFUNC_CMD_TKL, cmd_tkl, NULL);
 	efunc_init_function(EFUNC_PLACE_HOST_BAN, place_host_ban, NULL);
 	efunc_init_function(EFUNC_DOSPAMFILTER, match_spamfilter, NULL);
+	efunc_init_function(EFUNC_MATCH_SPAMFILTER_MTAGS, match_spamfilter_mtags, NULL);
 	efunc_init_function(EFUNC_DOSPAMFILTER_VIRUSCHAN, join_viruschan, NULL);
 	efunc_init_function(EFUNC_STRIPCOLORS, StripColors, NULL);
 	efunc_init_function(EFUNC_STRIPCONTROLCODES, StripControlCodes, NULL);

src/ircd.c

@@ -370,7 +370,7 @@ int match_tkls(Client *client)
 
 	if (loop.do_bancheck_spamf_away && IsUser(client) &&
 	    client->user->away != NULL &&
-	    match_spamfilter(client, client->user->away, SPAMF_AWAY, NULL, SPAMFLAG_NOWARN, NULL))
+	    match_spamfilter(client, client->user->away, SPAMF_AWAY, "AWAY", NULL, SPAMFLAG_NOWARN, NULL))
 	{
 		return 1;
 	}

src/misc.c

@@ -81,16 +81,17 @@ typedef struct {
 } SpamfilterTargetTable;
 
 SpamfilterTargetTable spamfiltertargettable[] = {
-	{ SPAMF_CHANMSG,	'c',	"channel",			"PRIVMSG" },
-	{ SPAMF_USERMSG,	'p',	"private",			"PRIVMSG" },
+	{ SPAMF_CHANMSG,	'c',	"channel",		"PRIVMSG" },
+	{ SPAMF_USERMSG,	'p',	"private",		"PRIVMSG" },
 	{ SPAMF_USERNOTICE,	'n',	"private-notice",	"NOTICE" },
 	{ SPAMF_CHANNOTICE,	'N',	"channel-notice",	"NOTICE" },
-	{ SPAMF_PART,		'P',	"part",				"PART" },
-	{ SPAMF_QUIT,		'q',	"quit",				"QUIT" },
-	{ SPAMF_DCC,		'd',	"dcc",				"PRIVMSG" },
-	{ SPAMF_USER,		'u',	"user",				"NICK" },
-	{ SPAMF_AWAY,		'a',	"away",				"AWAY" },
-	{ SPAMF_TOPIC,		't',	"topic",			"TOPIC" },
+	{ SPAMF_PART,		'P',	"part",			"PART" },
+	{ SPAMF_QUIT,		'q',	"quit",			"QUIT" },
+	{ SPAMF_DCC,		'd',	"dcc",			"PRIVMSG" },
+	{ SPAMF_USER,		'u',	"user",			"NICK" },
+	{ SPAMF_AWAY,		'a',	"away",			"AWAY" },
+	{ SPAMF_TOPIC,		't',	"topic",		"TOPIC" },
+	{ SPAMF_MTAG,		'T',	"message-tag",		"message-tag" },
 	{ 0, 0, 0, 0 }
 };
 

src/modules/away.c

@@ -86,7 +86,7 @@ CMD_FUNC(cmd_away)
 	}
 
 	/* Check spamfilters */
-	if (MyUser(client) && match_spamfilter(client, new_reason, SPAMF_AWAY, NULL, 0, NULL))
+	if (MyUser(client) && match_spamfilter(client, new_reason, SPAMF_AWAY, "AWAY", NULL, 0, NULL))
 		return;
 
 	/* Check set::anti-flood::away-flood */

src/modules/dccdeny.c

@@ -639,7 +639,7 @@ static int can_dcc(Client *client, char *target, Client *targetcli, char *filena
 		return 0;
 	}
 
-	if (match_spamfilter(client, filename, SPAMF_DCC, target, 0, NULL))
+	if (match_spamfilter(client, filename, SPAMF_DCC, "PRIVMSG", target, 0, NULL))
 		return 0;
 
 	if ((fl = dcc_isforbidden(client, filename)))

src/modules/message.c

@@ -117,8 +117,14 @@ int can_send_to_user(Client *client, Client *target, char **msgtext, char **errm
 	}
 
 	// Possible FIXME: make match_spamfilter also use errmsg, or via a wrapper? or use same numeric?
-	if (MyUser(client) && match_spamfilter(client, *msgtext, (sendtype == SEND_TYPE_NOTICE ? SPAMF_USERNOTICE : SPAMF_USERMSG), target->name, 0, NULL))
-		return 0;
+	if (MyUser(client))
+	{
+		int spamtype = (sendtype == SEND_TYPE_NOTICE ? SPAMF_USERNOTICE : SPAMF_USERMSG);
+		char *cmd = sendtype_to_cmd(sendtype);
+
+		if (match_spamfilter(client, *msgtext, spamtype, cmd, target->name, 0, NULL))
+			return 0;
+	}
 
 	n = HOOK_CONTINUE;
 	for (h = Hooks[HOOKTYPE_CAN_SEND_TO_USER]; h; h = h->next)
@@ -379,8 +385,13 @@ void cmd_message(Client *client, MessageTag *recv_mtags, int parc, char *parv[],
 			if ((*parv[2] == '\001') && strncmp(&parv[2][1], "ACTION ", 7))
 				sendflags |= SKIP_CTCP;
 
-			if (MyUser(client) && match_spamfilter(client, text, (sendtype == SEND_TYPE_NOTICE ? SPAMF_CHANNOTICE : SPAMF_CHANMSG), channel->chname, 0, NULL))
-				return;
+			if (MyUser(client))
+			{
+				int spamtype = (sendtype == SEND_TYPE_NOTICE ? SPAMF_USERNOTICE : SPAMF_USERMSG);
+
+				if (match_spamfilter(client, text, spamtype, cmd, channel->chname, 0, NULL))
+					return;
+			}
 
 			new_message(client, recv_mtags, &mtags);
 

src/modules/nick.c

@@ -298,7 +298,7 @@ CMD_FUNC(cmd_nick_local)
 	{
 		/* Local client changing nick: check spamfilter */
 		spamfilter_build_user_string(spamfilter_user, nick, client);
-		if (match_spamfilter(client, spamfilter_user, SPAMF_USER, NULL, 0, NULL))
+		if (match_spamfilter(client, spamfilter_user, SPAMF_USER, "NICK", NULL, 0, NULL))
 			return;
 	}
 
@@ -883,7 +883,7 @@ int _register_user(Client *client, char *nick, char *username, char *umode, char
 		find_shun(client);
 
 		spamfilter_build_user_string(spamfilter_user, client->name, client);
-		if (match_spamfilter(client, spamfilter_user, SPAMF_USER, NULL, 0, &savetkl))
+		if (match_spamfilter(client, spamfilter_user, SPAMF_USER, NULL, NULL, 0, &savetkl))
 		{
 			if (savetkl && ((savetkl->ptr.spamfilter->action == BAN_ACT_VIRUSCHAN) ||
 			                (savetkl->ptr.spamfilter->action == BAN_ACT_SOFT_VIRUSCHAN)))

src/modules/part.c

@@ -89,7 +89,7 @@ CMD_FUNC(cmd_part)
 		}
 		if (commentx)
 		{
-			if (match_spamfilter(client, commentx, SPAMF_PART, parv[1], 0, NULL))
+			if (match_spamfilter(client, commentx, SPAMF_PART, "PART", parv[1], 0, NULL))
 				commentx = NULL;
 			if (IsDead(client))
 				return;

src/modules/quit.c

@@ -82,7 +82,7 @@ CMD_FUNC(cmd_quit)
 			return;
 		}
 
-		if (match_spamfilter(client, comment, SPAMF_QUIT, NULL, 0, NULL))
+		if (match_spamfilter(client, comment, SPAMF_QUIT, "QUIT", NULL, 0, NULL))
 		{
 			comment = client->name;
 			if (IsDead(client))

src/modules/setname.c

@@ -89,7 +89,7 @@ CMD_FUNC(cmd_setname)
 		/* set the new name before we check, but don't send to servers unless it is ok */
 		strcpy(client->info, parv[1]);
 		spamfilter_build_user_string(spamfilter_user, client->name, client);
-		if (match_spamfilter(client, spamfilter_user, SPAMF_USER, NULL, 0, NULL))
+		if (match_spamfilter(client, spamfilter_user, SPAMF_USER, "SETNAME", NULL, 0, NULL))
 		{
 			/* Was rejected by spamfilter, restore the realname */
 			strcpy(client->info, tmpinfo);

src/modules/tkl.c

@@ -82,7 +82,9 @@ void _tkl_stats(Client *client, int type, char *para, int *cnt);
 void _tkl_sync(Client *client);
 CMD_FUNC(_cmd_tkl);
 int _place_host_ban(Client *client, BanAction action, char *reason, long duration);
-int _match_spamfilter(Client *client, char *str_in, int type, char *target, int flags, TKL **rettk);
+int _match_spamfilter(Client *client, char *str_in, int type, char *cmd, char *target, int flags, TKL **rettk);
+int _match_spamfilter_mtags(Client *client, MessageTag *mtags, char *cmd);
+int check_mtag_spamfilters_present(void);
 int _join_viruschan(Client *client, TKL *tk, int type);
 void _spamfilter_build_user_string(char *buf, char *nick, Client *client);
 int _match_user(char *rmask, Client *client, int options);
@@ -146,6 +148,7 @@ TKLTypeTable tkl_types[] = {
 #define ALL_VALID_EXCEPTION_TYPES "kline, gline, zline, gzline, spamfilter, shun, qline, blacklist, connect-flood, handshake-data-flood, antirandom, antimixedutf8, ban-version"
 
 int max_stats_matches = 1000;
+int mtag_spamfilters_present = 0; /**< Are any spamfilters with type SPAMF_MTAG present? */
 
 MOD_TEST()
 {
@@ -179,6 +182,7 @@ MOD_TEST()
 	EfunctionAddVoid(modinfo->handle, EFUNC_CMD_TKL, _cmd_tkl);
 	EfunctionAdd(modinfo->handle, EFUNC_PLACE_HOST_BAN, _place_host_ban);
 	EfunctionAdd(modinfo->handle, EFUNC_DOSPAMFILTER, _match_spamfilter);
+	EfunctionAdd(modinfo->handle, EFUNC_MATCH_SPAMFILTER_MTAGS, _match_spamfilter_mtags);
 	EfunctionAdd(modinfo->handle, EFUNC_DOSPAMFILTER_VIRUSCHAN, _join_viruschan);
 	EfunctionAddVoid(modinfo->handle, EFUNC_SPAMFILTER_BUILD_USER_STRING, _spamfilter_build_user_string);
 	EfunctionAdd(modinfo->handle, EFUNC_MATCH_USER, _match_user);
@@ -213,6 +217,7 @@ MOD_INIT()
 
 MOD_LOAD()
 {
+	check_mtag_spamfilters_present();
 	EventAdd(modinfo->handle, "tklexpire", tkl_check_expire, NULL, 5000, 0);
 	return MOD_SUCCESS;
 }
@@ -2383,6 +2388,9 @@ TKL *_tkl_add_spamfilter(int type, unsigned short target, BanAction action, Matc
 	index = tkl_hash(tkl_typetochar(type));
 	AddListItem(tkl, tklines[index]);
 
+	if (target & SPAMF_MTAG)
+		mtag_spamfilters_present = 1;
+
 	return tkl;
 }
 
@@ -2653,6 +2661,7 @@ void _tkl_del_line(TKL *tkl)
 
 	/* Finally, free the entry */
 	free_tkl(tkl);
+	check_mtag_spamfilters_present();
 }
 
 /** Add some default ban exceptions - for localhost */
@@ -3130,7 +3139,7 @@ int _find_spamfilter_user(Client *client, int flags)
 		return 0;
 
 	spamfilter_build_user_string(spamfilter_user, client->name, client);
-	return match_spamfilter(client, spamfilter_user, SPAMF_USER, NULL, flags, NULL);
+	return match_spamfilter(client, spamfilter_user, SPAMF_USER, NULL, NULL, flags, NULL);
 }
 
 /** Check a spamfilter against all local users and print a message.
@@ -4670,6 +4679,7 @@ int _join_viruschan(Client *client, TKL *tkl, int type)
 /** match_spamfilter: executes the spamfilter on the input string.
  * @param str		The text (eg msg text, notice text, part text, quit text, etc
  * @param target	The spamfilter target (SPAMF_*)
+ * @param cmd		The command (eg: "PRIVMSG")
  * @param destination	The destination as a text string (eg: "somenick", can be NULL.. eg for away)
  * @param flags		Any flags (SPAMFLAG_*)
  * @param rettkl	Pointer to an aTKLline struct, _used for special circumstances only_
@@ -4677,7 +4687,7 @@ int _join_viruschan(Client *client, TKL *tkl, int type)
  * 1 if spamfilter matched and it should be blocked (or client exited), 0 if not matched.
  * In case of 1, be sure to check IsDead(client)..
  */
-int _match_spamfilter(Client *client, char *str_in, int target, char *destination, int flags, TKL **rettkl)
+int _match_spamfilter(Client *client, char *str_in, int target, char *cmd, char *destination, int flags, TKL **rettkl)
 {
 	TKL *tkl;
 	TKL *winner_tkl = NULL;
@@ -4692,6 +4702,9 @@ int _match_spamfilter(Client *client, char *str_in, int target, char *destinatio
 	if (rettkl)
 		*rettkl = NULL; /* initialize to NULL */
 
+	if (!cmd)
+		cmd = cmdname_by_spamftarget(target);
+
 	if (target == SPAMF_USER)
 		str = str_in;
 	else
@@ -4771,7 +4784,7 @@ int _match_spamfilter(Client *client, char *str_in, int target, char *destinatio
 			ircsnprintf(buf, sizeof(buf), "[Spamfilter] %s!%s@%s matches filter '%s': [%s%s: '%s'] [%s]",
 				client->name, client->user->username, client->user->realhost,
 				tkl->ptr.spamfilter->match->str,
-				cmdname_by_spamftarget(target), destinationbuf, str,
+				cmd, destinationbuf, str,
 				unreal_decodespace(tkl->ptr.spamfilter->tkl_reason));
 
 			sendto_snomask_global(SNO_SPAMF, "%s", buf);
@@ -4823,6 +4836,12 @@ int _match_spamfilter(Client *client, char *str_in, int target, char *destinatio
 					me.name, client->name, destination, reason);
 				break;
 			}
+			case SPAMF_MTAG:
+			{
+				sendnumericfmt(client, ERR_CANNOTDOCOMMAND, "%s :Command blocked: %s",
+					cmd, reason);
+				break;
+			}
 			case SPAMF_DCC:
 			{
 				char errmsg[512];
@@ -4853,7 +4872,7 @@ int _match_spamfilter(Client *client, char *str_in, int target, char *destinatio
 	if ((tkl->ptr.spamfilter->action == BAN_ACT_WARN) || (tkl->ptr.spamfilter->action == BAN_ACT_SOFT_WARN))
 	{
 		if ((target != SPAMF_USER) && (target != SPAMF_QUIT))
-			sendnumeric(client, RPL_SPAMCMDFWD, cmdname_by_spamftarget(target), reason);
+			sendnumeric(client, RPL_SPAMCMDFWD, cmd, reason);
 		return 0;
 	} else
 	if ((tkl->ptr.spamfilter->action == BAN_ACT_DCCBLOCK) || (tkl->ptr.spamfilter->action == BAN_ACT_SOFT_DCCBLOCK))
@@ -4891,6 +4910,60 @@ int _match_spamfilter(Client *client, char *str_in, int target, char *destinatio
 	return 0; /* NOTREACHED */
 }
 
+/** Check message-tag spamfilters.
+ * @param client	The client
+ * @param mtags		Message tags sent by client
+ * @param cmd		Command to be executed (can be NULL)
+ * @retval Return 1 to stop processing the command (ignore it) or 0 to allow/continue as normal
+ */
+int _match_spamfilter_mtags(Client *client, MessageTag *mtags, char *cmd)
+{
+	MessageTag *m;
+	char buf[4096];
+	char *str;
+
+	/* This is a shortcut: if there are no spamfilters present
+	 * on message tags then we can return immediately.
+	 * Saves a lot of CPU and it is quite likely too!
+	 */
+	if (mtag_spamfilters_present == 0)
+		return 0;
+
+	for (m = mtags; m; m = m->next)
+	{
+		if (m->value)
+		{
+			snprintf(buf, sizeof(buf), "%s=%s", m->name, m->value);
+			str = buf;
+		} else {
+			str = m->name;
+		}
+		if (match_spamfilter(client, str, SPAMF_MTAG, cmd, NULL, 0, NULL))
+			return 1;
+	}
+	return 0;
+}
+
+/** Updates 'mtag_spamfilters_present' based on if any spamfilters
+ * are present with the SPAMF_MTAG target.
+ */
+int check_mtag_spamfilters_present(void)
+{
+	TKL *tkl;
+
+	for (tkl = tklines[tkl_hash('F')]; tkl; tkl = tkl->next)
+	{
+		if (tkl->ptr.spamfilter->target & SPAMF_MTAG)
+		{
+			mtag_spamfilters_present = 1;
+			return 1;
+		}
+	}
+
+	mtag_spamfilters_present = 0;
+	return 0;
+}
+
 /** CIDR function to compare the first 'mask' bits.
  * @author Taken from atheme
  * @returns 1 if equal, 0 if not.

src/modules/topic.c

@@ -242,7 +242,7 @@ CMD_FUNC(cmd_topic)
 			Hook *tmphook;
 			int n;
 
-			if (match_spamfilter(client, topic, SPAMF_TOPIC, channel->chname, 0, NULL))
+			if (match_spamfilter(client, topic, SPAMF_TOPIC, "TOPIC", channel->chname, 0, NULL))
 				return;
 
 			for (tmphook = Hooks[HOOKTYPE_PRE_LOCAL_TOPIC]; tmphook; tmphook = tmphook->next) {

src/parse.c

@@ -485,6 +485,11 @@ static void parse2(Client *cptr, Client **fromptr, MessageTag *mtags, char *ch)
 		}
 	}
 	para[++i] = NULL;
+
+	/* Check if one of the message tags are rejected by spamfilter */
+	if (MyConnect(from) && !IsServer(from) && match_spamfilter_mtags(from, mtags, cmptr ? cmptr->cmd : NULL))
+		return;
+
 	if (cmptr == NULL)
 	{
 		do_numeric(numeric, from, mtags, i, para);
@@ -494,6 +499,7 @@ static void parse2(Client *cptr, Client **fromptr, MessageTag *mtags, char *ch)
 	if (IsUser(cptr) && (cmptr->flags & CMD_RESETIDLE))
 		cptr->local->last = TStime();
 
+	/* Now ready to execute the command */
 #ifndef DEBUGMODE
 	if (cmptr->flags & CMD_ALIAS)
 	{