Remove old string functions.

More specifically, this removes the functions:
strcasecmp_n
strchr_n
strrchr_n

and replaces the calls with the respective C-library calls that should
be part of just about all operating systems by now.

src/analyzer/protocol/finger/Finger.cc

@@ -54,7 +54,8 @@ void Finger_Analyzer::DeliverStream(int length, const u_char* data, bool is_orig
 		if ( long_cnt )
 			line = skip_whitespace(line+2, end_of_line);
 
-		const char* at = strchr_n(line, end_of_line, '@');
+		assert(line <= end_of_line);
+		const char* at = reinterpret_cast<const char*>(memchr(line, '@', end_of_line - line));
 		const char* host = 0;
 		if ( ! at )
 			at = host = end_of_line;

src/analyzer/protocol/http/HTTP.cc

@@ -1370,7 +1370,7 @@ void HTTP_Analyzer::HTTP_Request()
 	const char* method = (const char*) request_method->AsString()->Bytes();
 	int method_len = request_method->AsString()->Len();
 
-	if ( strcasecmp_n(method_len, method, "CONNECT") == 0 )
+	if ( strncasecmp(method, "CONNECT", method_len) == 0 )
 		connect_request = true;
 
 	if ( http_request )
@@ -1564,7 +1564,7 @@ int HTTP_Analyzer::ExpectReplyMessageBody()
 
 	const BroString* method = UnansweredRequestMethod();
 
-	if ( method && strcasecmp_n(method->Len(), (const char*) (method->Bytes()), "HEAD") == 0 )
+	if ( method && strncasecmp((const char*) (method->Bytes()), "HEAD", method->Len()) == 0 )
 		return HTTP_BODY_NOT_EXPECTED;
 
 	if ( (reply_code >= 100 && reply_code < 200) ||

src/analyzer/protocol/ident/Ident.cc

@@ -153,8 +153,9 @@ void Ident_Analyzer::DeliverStream(int length, const u_char* data, bool is_orig)
 		else
 			{
 			const char* sys_type = line;
-			const char* colon = strchr_n(line, end_of_line, ':');
+			assert(line <= end_of_line);
-			const char* comma = strchr_n(line, end_of_line, ',');
+			const char* colon = reinterpret_cast<const char*>(memchr(line, ':', end_of_line - line));
+			const char* comma = reinterpret_cast<const char*>(memchr(line, ':', end_of_line - line));
 			if ( ! colon )
 				{
 				BadReply(length, orig_line);

src/analyzer/protocol/mime/MIME.cc

@@ -148,7 +148,7 @@ void MIME_Mail::Undelivered(int len)
 
 int strcasecmp_n(data_chunk_t s, const char* t)
 	{
-	return ::strcasecmp_n(s.length, s.data, t);
+	return strncasecmp(s.data, t, s.length);
 	}
 
 int MIME_count_leading_lws(int len, const char* data)

src/analyzer/protocol/smtp/SMTP.cc

@@ -809,7 +809,7 @@ void SMTP_Analyzer::ProcessExtension(int ext_len, const char* ext)
 	if ( ! ext )
 		return;
 
-	if ( ! strcasecmp_n(ext_len, ext, "PIPELINING") )
+	if ( ! strncasecmp(ext, "PIPELINING", ext_len) )
 		pipelining = 1;
 	}
 
@@ -819,7 +819,7 @@ int SMTP_Analyzer::ParseCmd(int cmd_len, const char* cmd)
 		return -1;
 
 	for ( int code = SMTP_CMD_EHLO; code < SMTP_CMD_LAST; ++code )
-		if ( ! strcasecmp_n(cmd_len, cmd, smtp_cmd_word[code - SMTP_CMD_EHLO]) )
+		if ( ! strncasecmp(cmd, smtp_cmd_word[code - SMTP_CMD_EHLO], cmd_len) )
 			return code;
 
 	return -1;

src/util.cc

@@ -323,24 +323,6 @@ string to_upper(const std::string& s)
 	return t;
 	}
 
-const char* strchr_n(const char* s, const char* end_of_s, char ch)
-	{
-	for ( ; s < end_of_s; ++s )
-		if ( *s == ch )
-			return s;
-
-	return 0;
-	}
-
-const char* strrchr_n(const char* s, const char* end_of_s, char ch)
-	{
-	for ( --end_of_s; end_of_s >= s; --end_of_s )
-		if ( *end_of_s == ch )
-			return end_of_s;
-
-	return 0;
-	}
-
 int decode_hex(char ch)
 	{
 	if ( ch >= '0' && ch <= '9' )
@@ -382,27 +364,6 @@ const char* strpbrk_n(size_t len, const char* s, const char* charset)
 	return 0;
 	}
 
-int strcasecmp_n(int b_len, const char* b, const char* t)
-	{
-	if ( ! b )
-		return -1;
-
-	int i;
-	for ( i = 0; i < b_len; ++i )
-		{
-		char c1 = islower(b[i]) ? toupper(b[i]) : b[i];
-		char c2 = islower(t[i]) ? toupper(t[i]) : t[i];
-
-		if ( c1 < c2 )
-			return -1;
-
-		if ( c1 > c2 )
-			return 1;
-		}
-
-	return t[i] != '\0';
-	}
-
 #ifndef HAVE_STRCASESTR
 // This code is derived from software contributed to BSD by Chris Torek.
 char* strcasestr(const char* s, const char* find)
@@ -421,7 +382,7 @@ char* strcasestr(const char* s, const char* find)
 				if ( sc == 0 )
 					return 0;
 			} while ( char(tolower((unsigned char) sc)) != c );
-		} while ( strcasecmp_n(len, s, find) != 0 );
+		} while ( strncasecmp(s, find, len) != 0 );
 
 		--s;
 		}

src/util.h

@@ -143,11 +143,8 @@ extern char* get_word(char*& s);
 extern void get_word(int length, const char* s, int& pwlen, const char*& pw);
 extern void to_upper(char* s);
 extern std::string to_upper(const std::string& s);
-extern const char* strchr_n(const char* s, const char* end_of_s, char ch);
-extern const char* strrchr_n(const char* s, const char* end_of_s, char ch);
 extern int decode_hex(char ch);
 extern unsigned char encode_hex(int h);
-extern int strcasecmp_n(int s_len, const char* s, const char* t);
 #ifndef HAVE_STRCASESTR
 extern char* strcasestr(const char* s, const char* find);
 #endif