detect/sip.stat_code: add sticky buffer

Matches on status code field in SIP.

rust/src/sip/detect.rs

@@ -99,3 +99,24 @@ pub unsafe extern "C" fn rs_sip_tx_get_protocol(tx:  &mut SIPTransaction,
 
     return 0;
 }
+
+#[no_mangle]
+pub unsafe extern "C" fn rs_sip_tx_get_stat_code(tx:  &mut SIPTransaction,
+                                                 buffer: *mut *const u8,
+                                                 buffer_len: *mut u32)
+                                                 -> u8
+{
+    if let Some(ref r) = tx.response {
+        let c = &r.code;
+        if c.len() > 0 {
+            *buffer = c.as_ptr();
+            *buffer_len = c.len() as u32;
+            return 1;
+        }
+    }
+
+    *buffer = ptr::null();
+    *buffer_len = 0;
+
+    return 0;
+}

src/Makefile.am

@@ -248,6 +248,7 @@ detect-snmp-version.c detect-snmp-version.h \
 detect-sip-method.c detect-sip-method.h \
 detect-sip-uri.c detect-sip-uri.h \
 detect-sip-protocol.c detect-sip-protocol.h \
+detect-sip-stat-code.c detect-sip-stat-code.h \
 detect-ssh-proto.c detect-ssh-proto.h \
 detect-ssh-proto-version.c detect-ssh-proto-version.h \
 detect-ssh-software.c detect-ssh-software.h \

src/detect-engine-register.c

@@ -182,6 +182,7 @@
 #include "detect-sip-method.h"
 #include "detect-sip-uri.h"
 #include "detect-sip-protocol.h"
+#include "detect-sip-stat-code.h"
 #include "detect-target.h"
 #include "detect-template-rust-buffer.h"
 #include "detect-snmp-version.h"
@@ -550,6 +551,7 @@ void SigTableSetup(void)
     DetectSipMethodRegister();
     DetectSipUriRegister();
     DetectSipProtocolRegister();
+    DetectSipStatCodeRegister();
     DetectTargetRegister();
     DetectTemplateRustBufferRegister();
     DetectSNMPVersionRegister();

src/detect-engine-register.h

@@ -229,6 +229,7 @@ enum {
     DETECT_AL_SIP_METHOD,
     DETECT_AL_SIP_URI,
     DETECT_AL_SIP_PROTOCOL,
+    DETECT_AL_SIP_STAT_CODE,
 
     DETECT_TEMPLATE,
     DETECT_TEMPLATE2,

src/detect-sip-stat-code.c

@@ -0,0 +1,121 @@
+/* Copyright (C) 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.
+ */
+
+/**
+ *
+ * \author Giuseppe Longo <giuseppe@glongo.it>
+ *
+ * Implements the sip.stat_code sticky buffer
+ *
+ */
+
+#include "suricata-common.h"
+#include "threads.h"
+#include "debug.h"
+#include "decode.h"
+#include "detect.h"
+
+#include "detect-parse.h"
+#include "detect-engine.h"
+#include "detect-engine-mpm.h"
+#include "detect-engine-prefilter.h"
+#include "detect-content.h"
+#include "detect-pcre.h"
+#include "detect-urilen.h"
+
+#include "flow.h"
+#include "flow-var.h"
+#include "flow-util.h"
+
+#include "util-debug.h"
+#include "util-unittest.h"
+#include "util-unittest-helper.h"
+#include "util-spm.h"
+
+#include "app-layer.h"
+#include "app-layer-parser.h"
+
+#include "detect-sip-stat-code.h"
+#include "stream-tcp.h"
+
+#include "rust.h"
+#include "app-layer-sip.h"
+#include "rust-sip-detect-gen.h"
+
+#define KEYWORD_NAME "sip.stat_code"
+#define KEYWORD_DOC  "sip-keywords.html#sip-stat-code"
+#define BUFFER_NAME  "sip.method"
+#define BUFFER_DESC  "sip response status code"
+static int g_buffer_id = 0;
+
+static int DetectSipStatCodeSetup(DetectEngineCtx *de_ctx, Signature *s, const char *str)
+{
+    if (DetectBufferSetActiveList(s, g_buffer_id) < 0)
+        return -1;
+
+    if (DetectSignatureSetAppProto(s, ALPROTO_SIP) < 0)
+        return -1;
+
+    return 0;
+}
+
+static InspectionBuffer *GetData(DetectEngineThreadCtx *det_ctx,
+        const DetectEngineTransforms *transforms, Flow *_f,
+        const uint8_t _flow_flags, void *txv, const int list_id)
+{
+    SCEnter();
+
+    InspectionBuffer *buffer = InspectionBufferGet(det_ctx, list_id);
+    if (buffer->inspect == NULL) {
+        const uint8_t *b = NULL;
+        uint32_t b_len = 0;
+
+        if (rs_sip_tx_get_stat_code(txv, &b, &b_len) != 1)
+            return NULL;
+        if (b == NULL || b_len == 0)
+            return NULL;
+
+        InspectionBufferSetup(buffer, b, b_len);
+        InspectionBufferApplyTransforms(buffer, transforms);
+    }
+
+    return buffer;
+}
+
+void DetectSipStatCodeRegister (void)
+{
+    /* sip.stat_code sticky buffer */
+    sigmatch_table[DETECT_AL_SIP_STAT_CODE].name = KEYWORD_NAME;
+    sigmatch_table[DETECT_AL_SIP_STAT_CODE].desc = "sticky buffer to match on the SIP status code";
+    sigmatch_table[DETECT_AL_SIP_STAT_CODE].url = DOC_URL DOC_VERSION "/rules/" KEYWORD_DOC;
+    sigmatch_table[DETECT_AL_SIP_STAT_CODE].Setup = DetectSipStatCodeSetup;
+    sigmatch_table[DETECT_AL_SIP_STAT_CODE].flags |= SIGMATCH_NOOPT;
+
+    DetectAppLayerInspectEngineRegister2(BUFFER_NAME, ALPROTO_SIP,
+            SIG_FLAG_TOCLIENT, 1,
+            DetectEngineInspectBufferGeneric, GetData);
+
+    DetectAppLayerMpmRegister2(BUFFER_NAME, SIG_FLAG_TOCLIENT, 4,
+            PrefilterGenericMpmRegister, GetData, ALPROTO_SIP,
+            1);
+
+    DetectBufferTypeSetDescriptionByName(BUFFER_NAME, BUFFER_DESC);
+
+    g_buffer_id = DetectBufferTypeGetByName(BUFFER_NAME);
+
+    SCLogDebug("registering " BUFFER_NAME " rule option");
+}

src/detect-sip-stat-code.h

@@ -0,0 +1,29 @@
+/* Copyright (C) 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 Giuseppe Longo <giuseppe@glongo.it>
+ */
+
+#ifndef __DETECT_SIP_STAT_CODE_H__
+#define __DETECT_SIP_STAT_CODE_H__
+
+void DetectSipStatCodeRegister(void);
+
+#endif /* __DETECT_SIP_STAT_CODE_H__ */