Merge #5828

5828: Ignore server info with control characters r=def- a=heinrich5991

This simply treats server info as invalid if it contains control
characters in any string.

Fixes #5826.

## Checklist

- [ ] Tested the change ingame
- [ ] Provided screenshots if it is a visual change
- [ ] Tested in combination with possibly related configuration options
- [ ] Written a unit test (especially base/) or added coverage to integration test
- [ ] Considered possible null pointers and out of bounds array indexing
- [ ] Changed no physics that affect existing maps
- [ ] Tested the change with [ASan+UBSan or valgrind's memcheck](https://github.com/ddnet/ddnet/#using-addresssanitizer--undefinedbehavioursanitizer-or-valgrinds-memcheck) (optional)


Co-authored-by: heinrich5991 <heinrich5991@gmail.com>

src/base/system.cpp

@@ -2650,6 +2650,20 @@ char *str_trim_words(char *str, int words)
 	return str;
 }
 
+bool str_has_cc(const char *str)
+{
+	unsigned char *s = (unsigned char *)str;
+	while(*s)
+	{
+		if(*s < 32)
+		{
+			return true;
+		}
+		s++;
+	}
+	return false;
+}
+
 /* makes sure that the string only contains the characters between 32 and 255 */
 void str_sanitize_cc(char *str_in)
 {

src/base/system.h

@@ -1249,6 +1249,19 @@ int str_format(char *buffer, int buffer_size, const char *format, ...)
  */
 char *str_trim_words(char *str, int words);
 
+/**
+ * Check whether string has ASCII control characters.
+ *
+ * @ingroup Strings
+ *
+ * @param str String to check.
+ *
+ * @return Whether the string has ASCII control characters.
+ *
+ * @remark The strings are treated as zero-terminated strings.
+ */
+bool str_has_cc(const char *str);
+
 /**
  * Replaces all characters below 32 with whitespace.
  *

src/engine/shared/serverinfo.cpp

@@ -74,10 +74,10 @@ bool CServerInfo2::FromJsonRaw(CServerInfo2 *pOut, const json_value *pJson)
 	Error = Error || MaxClients.type != json_integer;
 	Error = Error || MaxPlayers.type != json_integer;
 	Error = Error || Passworded.type != json_boolean;
-	Error = Error || GameType.type != json_string;
-	Error = Error || Name.type != json_string;
-	Error = Error || MapName.type != json_string;
-	Error = Error || Version.type != json_string;
+	Error = Error || GameType.type != json_string || str_has_cc(GameType);
+	Error = Error || Name.type != json_string || str_has_cc(Name);
+	Error = Error || MapName.type != json_string || str_has_cc(MapName);
+	Error = Error || Version.type != json_string || str_has_cc(Version);
 	Error = Error || Clients.type != json_array;
 	if(Error)
 	{
@@ -102,8 +102,8 @@ bool CServerInfo2::FromJsonRaw(CServerInfo2 *pOut, const json_value *pJson)
 		const json_value &Score = Client["score"];
 		const json_value &IsPlayer = Client["is_player"];
 		Error = false;
-		Error = Error || ClientName.type != json_string;
-		Error = Error || Clan.type != json_string;
+		Error = Error || ClientName.type != json_string || str_has_cc(ClientName);
+		Error = Error || Clan.type != json_string || str_has_cc(ClientName);
 		Error = Error || Country.type != json_integer;
 		Error = Error || Score.type != json_integer;
 		Error = Error || IsPlayer.type != json_boolean;

src/test/str.cpp

@@ -337,7 +337,7 @@ TEST(Str, InList)
 	EXPECT_TRUE(str_in_list("abc,,def", ",", "def"));
 }
 
-TEST(Str, StrFormat)
+TEST(Str, Format)
 {
 	char aBuf[4];
 	EXPECT_EQ(str_format(aBuf, 4, "%d:", 9), 2);
@@ -348,7 +348,7 @@ TEST(Str, StrFormat)
 	EXPECT_STREQ(aBuf, "99:");
 }
 
-TEST(Str, StrFormatTruncate)
+TEST(Str, FormatTruncate)
 {
 	const char *pStr = "DDNet最好了";
 	char aBuf[64];
@@ -374,7 +374,7 @@ TEST(Str, StrFormatTruncate)
 	EXPECT_STREQ(aBuf, "DDNet最好了");
 }
 
-TEST(Str, StrCopyNum)
+TEST(Str, CopyNum)
 {
 	const char *pFoo = "Foobaré";
 	char aBuf[64];
@@ -399,7 +399,7 @@ TEST(Str, StrCopyNum)
 	EXPECT_STREQ(aBuf3, "Foobaré");
 }
 
-TEST(Str, StrCopy)
+TEST(Str, Copy)
 {
 	const char *pStr = "DDNet最好了";
 	char aBuf[64];
@@ -462,7 +462,7 @@ TEST(Str, Utf8Stats)
 	EXPECT_EQ(Count, 3);
 }
 
-TEST(Str, StrTime)
+TEST(Str, Time)
 {
 	char aBuf[32] = "foobar";
 
@@ -514,7 +514,7 @@ TEST(Str, StrTime)
 	EXPECT_STREQ(aBuf, "2057:36.78");
 }
 
-TEST(Str, StrTimeFloat)
+TEST(Str, TimeFloat)
 {
 	char aBuf[64];
 	EXPECT_EQ(str_time_float(123456.78, TIME_DAYS, aBuf, sizeof(aBuf)), 11);
@@ -523,3 +523,19 @@ TEST(Str, StrTimeFloat)
 	EXPECT_EQ(str_time_float(12.16, TIME_HOURS_CENTISECS, aBuf, sizeof(aBuf)), 8);
 	EXPECT_STREQ(aBuf, "00:12.16");
 }
+
+TEST(Str, HasCc)
+{
+	EXPECT_FALSE(str_has_cc(""));
+	EXPECT_FALSE(str_has_cc("a"));
+	EXPECT_FALSE(str_has_cc("Merhaba dünya!"));
+
+	EXPECT_TRUE(str_has_cc("\n"));
+	EXPECT_TRUE(str_has_cc("\n"));
+	EXPECT_TRUE(str_has_cc("\r"));
+	EXPECT_TRUE(str_has_cc("\t"));
+	EXPECT_TRUE(str_has_cc("a\n"));
+	EXPECT_TRUE(str_has_cc("a\rb"));
+	EXPECT_TRUE(str_has_cc("\tb"));
+	EXPECT_TRUE(str_has_cc("\n\n"));
+}