From 3d87f28751db84fae47ec33925de050b7ad8ec11 Mon Sep 17 00:00:00 2001
From: codemastr <devnull@localhost>
Date: Mon, 8 Mar 2004 03:38:16 +0000
Subject: [PATCH] Added check to detect broad /spamfilter masks

---
 Changes             |  3 +++
 include/h.h         |  2 +-
 src/modules/m_tkl.c |  2 +-
 src/s_conf.c        |  4 ++--
 src/s_misc.c        | 10 +++++++++-
 5 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/Changes b/Changes
index 3cf620aeb..af66fdc76 100644
--- a/Changes
+++ b/Changes
@@ -3014,3 +3014,6 @@ seen. gmtime warning still there
 *** RC2fix release ***
 - spamfilter.conf: fixed fyle sig (was bad!), some minor updates to the rest,
   added mirc 6.12 exploit sig. Reported by PHANTOm.
+- Added a check to try and prevent people from adding all-encompassing
+  regexp's in /spamfilter. Thanks to Ville Laurikari for coming up with the
+  method!
diff --git a/include/h.h b/include/h.h
index f8871e103..1f7d95b52 100644
--- a/include/h.h
+++ b/include/h.h
@@ -646,7 +646,7 @@ extern void extban_init(void);
 extern char *trim_str(char *str, int len);
 extern char *ban_realhost, *ban_virthost, *ban_ip;
 extern void join_channel(aChannel *chptr, aClient *cptr, aClient *sptr, int flags);
-extern char *unreal_checkregex(char *s, int fastsupport);
+extern char *unreal_checkregex(char *s, int fastsupport, int check_broadness);
 extern int banact_stringtoval(char *s);
 extern char *banact_valtostring(int val);
 extern int banact_chartoval(char c);
diff --git a/src/modules/m_tkl.c b/src/modules/m_tkl.c
index 1db3b18c9..14a15a55c 100644
--- a/src/modules/m_tkl.c
+++ b/src/modules/m_tkl.c
@@ -563,7 +563,7 @@ char targetbuf[64], actionbuf[2];
 	actionbuf[1] = '\0';
 	
 	/* now check the regex... */
-	p = unreal_checkregex(parv[6],0);
+	p = unreal_checkregex(parv[6],0,1);
 	if (p)
 	{
 		sendto_one(sptr, ":%s NOTICE %s :Error in regex '%s': %s",
diff --git a/src/s_conf.c b/src/s_conf.c
index 390c44f8b..91e91fd82 100644
--- a/src/s_conf.c
+++ b/src/s_conf.c
@@ -4681,7 +4681,7 @@ int _test_badword(ConfigFile *conf, ConfigEntry *ce) {
 		}
 		else 
 		{
-			char *errbuf = unreal_checkregex(word->ce_vardata,1);
+			char *errbuf = unreal_checkregex(word->ce_vardata,1,0);
 			if (errbuf)
 			{
 				config_error("%s:%i: badword::%s contains an invalid regex: %s",
@@ -4836,7 +4836,7 @@ int _test_spamfilter(ConfigFile *conf, ConfigEntry *ce)
 		errors++;
 	} else if (cep->ce_vardata) {
 		/* Check if it's a valid one */
-		char *errbuf = unreal_checkregex(cep->ce_vardata,0);
+		char *errbuf = unreal_checkregex(cep->ce_vardata,0,0);
 		if (errbuf)
 		{
 			config_error("%s:%i: spamfilter::regex contains an invalid regex: %s",
diff --git a/src/s_misc.c b/src/s_misc.c
index a3ed70c4c..8a05bf467 100644
--- a/src/s_misc.c
+++ b/src/s_misc.c
@@ -775,8 +775,10 @@ char *p;
 /** Checks if the specified regex (or fast badwords) is valid.
  * returns NULL in case of success [!],
  * pointer to buffer with error message otherwise
+ * if check_broadness is 1, the function will attempt to determine
+ * if the given regex string is too broad (i.e. matches everything)
  */
-char *unreal_checkregex(char *s, int fastsupport)
+char *unreal_checkregex(char *s, int fastsupport, int check_broadness)
 {
 int errorcode, errorbufsize, regex=0;
 char *errtmp, *tmp;
@@ -810,6 +812,12 @@ Ilovegotos:
 			regfree(&expr);
 			return errorbuf;
 		}
+		if (check_broadness && !regexec(&expr, "", 0, NULL, 0))
+		{
+			strncpyzt(errorbuf, "Regular expression is too broad", sizeof(errorbuf));
+			regfree(&expr);
+			return errorbuf;
+		}
 		regfree(&expr);
 	}
 	return NULL;