detect/ipv4: add ipv4.hdr sticky buffer

src/Makefile.am

@@ -201,6 +201,7 @@ detect-id.c detect-id.h \
 detect-ipopts.c detect-ipopts.h \
 detect-ipproto.c detect-ipproto.h \
 detect-iprep.c detect-iprep.h \
+detect-ipv4hdr.c detect-ipv4hdr.h \
 detect-isdataat.c detect-isdataat.h \
 detect-itype.c detect-itype.h \
 detect-krb5-cname.c detect-krb5-cname.h \

src/detect-engine-register.c

@@ -170,6 +170,7 @@
 #include "detect-tcphdr.h"
 #include "detect-tcpmss.h"
 #include "detect-udphdr.h"
+#include "detect-ipv4hdr.h"
 #include "detect-krb5-cname.h"
 #include "detect-krb5-errcode.h"
 #include "detect-krb5-msgtype.h"
@@ -529,6 +530,7 @@ void SigTableSetup(void)
     DetectTcphdrRegister();
     DetectUdphdrRegister();
     DetectTcpmssRegister();
+    DetectIpv4hdrRegister();
     DetectKrb5CNameRegister();
     DetectKrb5ErrCodeRegister();
     DetectKrb5MsgTypeRegister();

src/detect-engine-register.h

@@ -225,6 +225,7 @@ enum {
 
     DETECT_TEMPLATE,
     DETECT_TEMPLATE2,
+    DETECT_IPV4HDR,
     DETECT_TCPHDR,
     DETECT_UDPHDR,
     DETECT_TCPMSS,

src/detect-ipv4hdr.c

@@ -0,0 +1,125 @@
+/* Copyright (C) 2007-2019 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.
+ */
+
+/**
+ * \file
+ *
+ * \author Victor Julien <victor@inliniac.net>
+ *
+ */
+
+#include "suricata-common.h"
+
+#include "detect.h"
+#include "detect-parse.h"
+#include "detect-engine.h"
+#include "detect-engine-mpm.h"
+#include "detect-engine-prefilter.h"
+#include "detect-engine-content-inspection.h"
+#include "detect-fast-pattern.h"
+#include "detect-ipv4hdr.h"
+
+/* prototypes */
+static int DetectIpv4hdrSetup (DetectEngineCtx *, Signature *, const char *);
+#ifdef UNITTESTS
+void DetectIpv4hdrRegisterTests (void);
+#endif
+
+static int g_ipv4hdr_buffer_id = 0;
+
+static InspectionBuffer *GetData(DetectEngineThreadCtx *det_ctx,
+        const DetectEngineTransforms *transforms, Packet *p, const int list_id);
+
+/**
+ * \brief Registration function for ipv4.hdr: keyword
+ */
+void DetectIpv4hdrRegister(void)
+{
+    sigmatch_table[DETECT_IPV4HDR].name = "ipv4.hdr";
+    sigmatch_table[DETECT_IPV4HDR].desc = "sticky buffer to match on the IPV4 header";
+    sigmatch_table[DETECT_IPV4HDR].url = DOC_URL DOC_VERSION "/rules/header-keywords.html#ipv4hdr";
+    sigmatch_table[DETECT_IPV4HDR].Setup = DetectIpv4hdrSetup;
+    sigmatch_table[DETECT_IPV4HDR].flags |= SIGMATCH_NOOPT | SIGMATCH_INFO_STICKY_BUFFER;
+#ifdef UNITTESTS
+    sigmatch_table[DETECT_IPV4HDR].RegisterTests = DetectIpv4hdrRegisterTests;
+#endif
+
+    g_ipv4hdr_buffer_id = DetectBufferTypeRegister("ipv4.hdr");
+    BUG_ON(g_ipv4hdr_buffer_id < 0);
+
+    DetectBufferTypeSupportsPacket("ipv4.hdr");
+
+    DetectPktMpmRegister("ipv4.hdr", 2, PrefilterGenericMpmPktRegister, GetData);
+
+    DetectPktInspectEngineRegister("ipv4.hdr", GetData,
+            DetectEngineInspectPktBufferGeneric);
+
+    return;
+}
+
+/**
+ * \brief setup ipv4.hdr sticky buffer
+ *
+ * \param de_ctx pointer to the Detection Engine Context
+ * \param s pointer to the Current Signature
+ * \param _unused unused
+ *
+ * \retval 0 on Success
+ * \retval -1 on Failure
+ */
+static int DetectIpv4hdrSetup (DetectEngineCtx *de_ctx, Signature *s, const char *_unused)
+{
+    s->proto.flags |= DETECT_PROTO_IPV4; // TODO
+
+    s->flags |= SIG_FLAG_REQUIRE_PACKET;
+
+    if (DetectBufferSetActiveList(s, g_ipv4hdr_buffer_id) < 0)
+        return -1;
+
+    return 0;
+}
+
+static InspectionBuffer *GetData(DetectEngineThreadCtx *det_ctx,
+        const DetectEngineTransforms *transforms, Packet *p, const int list_id)
+{
+    SCEnter();
+
+    InspectionBuffer *buffer = InspectionBufferGet(det_ctx, list_id);
+    if (buffer->inspect == NULL) {
+        uint32_t hlen = IPV4_GET_HLEN(p);
+        if (((uint8_t *)p->ip4h + (ptrdiff_t)hlen) >
+                ((uint8_t *)GET_PKT_DATA(p) + (ptrdiff_t)GET_PKT_LEN(p)))
+        {
+            SCLogDebug("data out of range: %p > %p",
+                    ((uint8_t *)p->ip4h + (ptrdiff_t)hlen),
+                    ((uint8_t *)GET_PKT_DATA(p) + (ptrdiff_t)GET_PKT_LEN(p)));
+            return NULL;
+        }
+
+        const uint32_t data_len = hlen;
+        const uint8_t *data = (const uint8_t *)p->ip4h;
+
+        InspectionBufferSetup(buffer, data, data_len);
+        InspectionBufferApplyTransforms(buffer, transforms);
+    }
+
+    return buffer;
+}
+
+#ifdef UNITTESTS
+#include "tests/detect-ipv4hdr.c"
+#endif

src/detect-ipv4hdr.h

@@ -0,0 +1,29 @@
+/* Copyright (C) 2007-2019 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.
+ */
+
+/**
+ * \file
+ *
+ * \author Victor Julien <victor@inliniac.net>
+ */
+
+#ifndef _DETECT_IPV4HDR_H
+#define _DETECT_IPV4HDR_H
+
+void DetectIpv4hdrRegister(void);
+
+#endif	/* _DETECT_IPV4HDR_H */

src/tests/detect-ipv4hdr.c

@@ -0,0 +1,47 @@
+/* Copyright (C) 2007-2018 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.
+ */
+
+#include "../suricata-common.h"
+
+#include "../detect.h"
+#include "../detect-parse.h"
+#include "../detect-engine-prefilter-common.h"
+
+#include "../detect-ipv4hdr.h"
+
+#include "../util-unittest.h"
+
+static int DetectIpv4hdrParseTest01 (void)
+{
+    DetectEngineCtx *de_ctx = DetectEngineCtxInit();
+    FAIL_IF_NULL(de_ctx);
+
+    Signature *sig = DetectEngineAppendSig(de_ctx,
+            "alert ip any any -> any any (ipv4.hdr; content:\"A\"; sid:1; rev:1;)");
+    FAIL_IF_NULL(sig);
+
+    DetectEngineCtxFree(de_ctx);
+    PASS;
+}
+
+/**
+ * \brief this function registers unit tests for DetectIpv4hdr
+ */
+void DetectIpv4hdrRegisterTests(void)
+{
+    UtRegisterTest("DetectIpv4hdrParseTest01", DetectIpv4hdrParseTest01);
+}