1 files changed, 153 insertions, 0 deletions
diff --git a/src/detect-sip-method.c b/src/detect-sip-method.c
new file mode 100644
index 0000000..fccc8a7
--- /dev/null
+++ b/src/detect-sip-method.c
@@ -0,0 +1,153 @@
+/* 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.method sticky buffer
+ *
+ */
+
+#include "suricata-common.h"
+#include "threads.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 "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-method.h"
+#include "stream-tcp.h"
+
+#include "rust.h"
+#include "app-layer-sip.h"
+
+#define KEYWORD_NAME "sip.method"
+#define KEYWORD_DOC  "sip-keywords.html#sip-method"
+#define BUFFER_NAME  "sip.method"
+#define BUFFER_DESC  "sip request method"
+static int g_buffer_id = 0;
+
+static int DetectSipMethodSetup(DetectEngineCtx *de_ctx, Signature *s, const char *str)
+{
+    if (DetectBufferSetActiveList(de_ctx, s, g_buffer_id) < 0)
+        return -1;
+
+    if (DetectSignatureSetAppProto(s, ALPROTO_SIP) < 0)
+        return -1;
+
+    return 0;
+}
+
+static bool DetectSipMethodValidateCallback(const Signature *s, const char **sigerror)
+{
+    for (uint32_t x = 0; x < s->init_data->buffer_index; x++) {
+        if (s->init_data->buffers[x].id != (uint32_t)g_buffer_id)
+            continue;
+        const SigMatch *sm = s->init_data->buffers[x].head;
+        for (; sm != NULL; sm = sm->next) {
+            if (sm->type != DETECT_CONTENT)
+                continue;
+            const DetectContentData *cd = (const DetectContentData *)sm->ctx;
+            if (cd->content && cd->content_len) {
+                if (cd->content[cd->content_len - 1] == 0x20) {
+                    *sigerror = "sip.method pattern with trailing space";
+                    SCLogError("%s", *sigerror);
+                    return true;
+                } else if (cd->content[0] == 0x20) {
+                    *sigerror = "sip.method pattern with leading space";
+                    SCLogError("%s", *sigerror);
+                    return true;
+                } else if (cd->content[cd->content_len - 1] == 0x09) {
+                    *sigerror = "sip.method pattern with trailing tab";
+                    SCLogError("%s", *sigerror);
+                    return true;
+                } else if (cd->content[0] == 0x09) {
+                    *sigerror = "sip.method pattern with leading tab";
+                    SCLogError("%s", *sigerror);
+                    return true;
+                }
+            }
+        }
+    }
+    return true;
+}
+
+static InspectionBuffer *GetData(DetectEngineThreadCtx *det_ctx,
+        const DetectEngineTransforms *transforms, Flow *_f,
+        const uint8_t _flow_flags, void *txv, const int list_id)
+{
+    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_method(txv, &b, &b_len) != 1)
+            return NULL;
+        if (b == NULL || b_len == 0)
+            return NULL;
+
+        InspectionBufferSetup(det_ctx, list_id, buffer, b, b_len);
+        InspectionBufferApplyTransforms(buffer, transforms);
+    }
+
+    return buffer;
+}
+
+void DetectSipMethodRegister(void)
+{
+    /* sip.method sticky buffer */
+    sigmatch_table[DETECT_AL_SIP_METHOD].name = KEYWORD_NAME;
+    sigmatch_table[DETECT_AL_SIP_METHOD].desc = "sticky buffer to match on the SIP method buffer";
+    sigmatch_table[DETECT_AL_SIP_METHOD].url = "/rules/" KEYWORD_DOC;
+    sigmatch_table[DETECT_AL_SIP_METHOD].Setup = DetectSipMethodSetup;
+    sigmatch_table[DETECT_AL_SIP_METHOD].flags |= SIGMATCH_NOOPT;
+
+    DetectAppLayerInspectEngineRegister2(BUFFER_NAME, ALPROTO_SIP,
+            SIG_FLAG_TOSERVER, 0,
+            DetectEngineInspectBufferGeneric, GetData);
+
+    DetectAppLayerMpmRegister2(BUFFER_NAME, SIG_FLAG_TOSERVER, 2,
+            PrefilterGenericMpmRegister, GetData, ALPROTO_SIP,
+            1);
+
+    DetectBufferTypeSetDescriptionByName(BUFFER_NAME, BUFFER_DESC);
+
+    DetectBufferTypeRegisterValidateCallback(BUFFER_NAME,
+            DetectSipMethodValidateCallback);
+
+    g_buffer_id = DetectBufferTypeGetByName(BUFFER_NAME);
+
+    SCLogDebug("registering " BUFFER_NAME " rule option");
+}