detect: implement http_content_len sticky buffer

This implements inspection of the Content-Length buffer as a content
sticky buffer.

src/Makefile.am

@@ -168,6 +168,7 @@ detect-http-accept-enc.c detect-http-accept-enc.h \
 detect-http-accept-lang.c detect-http-accept-lang.h \
 detect-http-client-body.c detect-http-client-body.h \
 detect-http-connection.c detect-http-connection.h \
+detect-http-content-len.c detect-http-content-len.h \
 detect-http-content-type.c detect-http-content-type.h \
 detect-http-cookie.c detect-http-cookie.h \
 detect-http-header.c detect-http-header.h \

src/detect-http-content-len.c

@@ -0,0 +1,47 @@
+/* Copyright (C) 2007-2017 Open Information Security Foundation
+ *
+ * You can copy, redistribute or modify this Program under the terms of
+ * the GNU General Public License version 2 as published by the Free
+ * Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+/**
+ * \ingroup httplayer
+ *
+ * @{
+ */
+
+
+/**
+ * \file
+ *
+ * \author Victor Julien <victor@inliniac.net>
+ *
+ * Implements http_content_len sticky buffer
+ */
+
+#define KEYWORD_NAME "http_content_len"
+#define KEYWORD_DOC "http-keywords#http-content-len"
+#define BUFFER_NAME "http_content_len"
+#define BUFFER_DESC "http content length header"
+#define HEADER_NAME "Content-Length"
+#define KEYWORD_ID DETECT_AL_HTTP_HEADER_CONTENT_LEN
+#define KEYWORD_TOSERVER 1
+#define KEYWORD_TOCLIENT 1
+
+#include "detect-http-headers-stub.h"
+
+void RegisterHttpHeadersContentLen(void)
+{
+    DetectHttpHeadersRegisterStub();
+}

src/detect-http-content-len.h

@@ -0,0 +1,23 @@
+/* Copyright (C) 2007-2017 Open Information Security Foundation
+ *
+ * You can copy, redistribute or modify this Program under the terms of
+ * the GNU General Public License version 2 as published by the Free
+ * Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+#ifndef __DETECT_HTTP_CONTENT_LEN_H__
+#define __DETECT_HTTP_CONTENT_LEN_H__
+
+void RegisterHttpHeadersContentLen(void);
+
+#endif /* __DETECT_HTTP_CONTENT_LEN_H__ */

src/detect-http-headers.c

@@ -19,6 +19,7 @@
 #include "detect-http-accept-enc.h"
 #include "detect-http-accept-lang.h"
 #include "detect-http-connection.h"
+#include "detect-http-content-len.h"
 #include "detect-http-content-type.h"
 #include "detect-http-referer.h"
 
@@ -29,5 +30,7 @@ void DetectHttpHeadersRegister(void)
     RegisterHttpHeadersAcceptLang();
     RegisterHttpHeadersReferer();
     RegisterHttpHeadersConnection();
+    RegisterHttpHeadersContentLen();
     RegisterHttpHeadersContentType();
 }
+

src/detect.h

@@ -1245,6 +1245,7 @@ enum {
     DETECT_AL_HTTP_HEADER_ACCEPT_LANG,
     DETECT_AL_HTTP_HEADER_ACCEPT_ENC,
     DETECT_AL_HTTP_HEADER_CONNECTION,
+    DETECT_AL_HTTP_HEADER_CONTENT_LEN,
     DETECT_AL_HTTP_HEADER_CONTENT_TYPE,
     DETECT_AL_HTTP_HEADER_REFERER,
     DETECT_AL_HTTP_RAW_HEADER,