Adding upstream version 1:7.0.3.upstream/1%7.0.3

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 879 insertions, 0 deletions

diff --git a/src/detect-dns-query.c b/src/detect-dns-query.c
new file mode 100644
index 0000000..354c4f8
--- /dev/null
+++ b/src/detect-dns-query.c
@@ -0,0 +1,879 @@
+/* Copyright (C) 2013-2018 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.
+ */
+
+/**
+ * \ingroup dnslayer
+ *
+ * @{
+ */
+
+
+/**
+ * \file
+ *
+ * \author Victor Julien <victor@inliniac.net>
+ */
+
+#include "suricata-common.h"
+#include "threads.h"
+#include "decode.h"
+#include "detect.h"
+
+#include "detect-parse.h"
+#include "detect-engine.h"
+#include "detect-engine-build.h"
+#include "detect-engine-mpm.h"
+#include "detect-engine-prefilter.h"
+#include "detect-engine-content-inspection.h"
+#include "detect-content.h"
+#include "detect-pcre.h"
+
+#include "flow.h"
+#include "flow-util.h"
+#include "flow-var.h"
+
+#include "util-debug.h"
+#include "util-unittest.h"
+#include "util-spm.h"
+#include "util-print.h"
+
+#include "stream-tcp.h"
+
+#include "app-layer.h"
+#include "app-layer-parser.h"
+#include "detect-dns-query.h"
+
+#include "util-profiling.h"
+#include "util-unittest-helper.h"
+#include "rust.h"
+
+static int DetectDnsQuerySetup (DetectEngineCtx *, Signature *, const char *);
+#ifdef UNITTESTS
+static void DetectDnsQueryRegisterTests(void);
+#endif
+static int g_dns_query_buffer_id = 0;
+
+struct DnsQueryGetDataArgs {
+    uint32_t local_id; /**< used as index into thread inspect array */
+    void *txv;
+};
+
+static InspectionBuffer *DnsQueryGetData(DetectEngineThreadCtx *det_ctx,
+        const DetectEngineTransforms *transforms, Flow *f, struct DnsQueryGetDataArgs *cbdata,
+        int list_id)
+{
+    SCEnter();
+
+    InspectionBuffer *buffer =
+            InspectionBufferMultipleForListGet(det_ctx, list_id, cbdata->local_id);
+    if (buffer == NULL)
+        return NULL;
+    if (buffer->initialized)
+        return buffer;
+
+    const uint8_t *data;
+    uint32_t data_len;
+    if (rs_dns_tx_get_query_name(cbdata->txv, cbdata->local_id, &data, &data_len) == 0) {
+        InspectionBufferSetupMultiEmpty(buffer);
+        return NULL;
+    }
+    InspectionBufferSetupMulti(buffer, transforms, data, data_len);
+
+    SCReturnPtr(buffer, "InspectionBuffer");
+}
+
+static uint8_t DetectEngineInspectDnsQuery(DetectEngineCtx *de_ctx, DetectEngineThreadCtx *det_ctx,
+        const DetectEngineAppInspectionEngine *engine, const Signature *s, Flow *f, uint8_t flags,
+        void *alstate, void *txv, uint64_t tx_id)
+{
+    uint32_t local_id = 0;
+
+    const DetectEngineTransforms *transforms = NULL;
+    if (!engine->mpm) {
+        transforms = engine->v2.transforms;
+    }
+
+    while(1) {
+        struct DnsQueryGetDataArgs cbdata = { local_id, txv, };
+        InspectionBuffer *buffer =
+                DnsQueryGetData(det_ctx, transforms, f, &cbdata, engine->sm_list);
+        if (buffer == NULL || buffer->inspect == NULL)
+            break;
+
+        det_ctx->buffer_offset = 0;
+        det_ctx->discontinue_matching = 0;
+        det_ctx->inspection_recursion_counter = 0;
+
+        const int match = DetectEngineContentInspection(de_ctx, det_ctx, s, engine->smd,
+                                              NULL, f,
+                                              (uint8_t *)buffer->inspect,
+                                              buffer->inspect_len,
+                                              buffer->inspect_offset, DETECT_CI_FLAGS_SINGLE,
+                                              DETECT_ENGINE_CONTENT_INSPECTION_MODE_STATE);
+        if (match == 1) {
+            return DETECT_ENGINE_INSPECT_SIG_MATCH;
+        }
+        local_id++;
+    }
+    return DETECT_ENGINE_INSPECT_SIG_NO_MATCH;
+}
+
+typedef struct PrefilterMpmDnsQuery {
+    int list_id;
+    const MpmCtx *mpm_ctx;
+    const DetectEngineTransforms *transforms;
+} PrefilterMpmDnsQuery;
+
+/** \brief DnsQuery DnsQuery Mpm prefilter callback
+ *
+ *  \param det_ctx detection engine thread ctx
+ *  \param p packet to inspect
+ *  \param f flow to inspect
+ *  \param txv tx to inspect
+ *  \param pectx inspection context
+ */
+static void PrefilterTxDnsQuery(DetectEngineThreadCtx *det_ctx, const void *pectx, Packet *p,
+        Flow *f, void *txv, const uint64_t idx, const AppLayerTxData *_txd, const uint8_t flags)
+{
+    SCEnter();
+
+    const PrefilterMpmDnsQuery *ctx = (const PrefilterMpmDnsQuery *)pectx;
+    const MpmCtx *mpm_ctx = ctx->mpm_ctx;
+    const int list_id = ctx->list_id;
+
+    uint32_t local_id = 0;
+    while(1) {
+        // loop until we get a NULL
+
+        struct DnsQueryGetDataArgs cbdata = { local_id, txv };
+        InspectionBuffer *buffer = DnsQueryGetData(det_ctx, ctx->transforms, f, &cbdata, list_id);
+        if (buffer == NULL)
+            break;
+
+        if (buffer->inspect_len >= mpm_ctx->minlen) {
+            (void)mpm_table[mpm_ctx->mpm_type].Search(mpm_ctx,
+                    &det_ctx->mtcu, &det_ctx->pmq,
+                    buffer->inspect, buffer->inspect_len);
+            PREFILTER_PROFILING_ADD_BYTES(det_ctx, buffer->inspect_len);
+        }
+
+        local_id++;
+    }
+}
+
+static void PrefilterMpmDnsQueryFree(void *ptr)
+{
+    SCFree(ptr);
+}
+
+static int PrefilterMpmDnsQueryRegister(DetectEngineCtx *de_ctx, SigGroupHead *sgh, MpmCtx *mpm_ctx,
+        const DetectBufferMpmRegistry *mpm_reg, int list_id)
+{
+    PrefilterMpmDnsQuery *pectx = SCCalloc(1, sizeof(*pectx));
+    if (pectx == NULL)
+        return -1;
+    pectx->list_id = list_id;
+    pectx->mpm_ctx = mpm_ctx;
+    pectx->transforms = &mpm_reg->transforms;
+
+    return PrefilterAppendTxEngine(de_ctx, sgh, PrefilterTxDnsQuery,
+            mpm_reg->app_v2.alproto, mpm_reg->app_v2.tx_min_progress,
+            pectx, PrefilterMpmDnsQueryFree, mpm_reg->pname);
+}
+
+/**
+ * \brief Registration function for keyword: dns_query
+ */
+void DetectDnsQueryRegister (void)
+{
+    sigmatch_table[DETECT_AL_DNS_QUERY].name = "dns.query";
+    sigmatch_table[DETECT_AL_DNS_QUERY].alias = "dns_query";
+    sigmatch_table[DETECT_AL_DNS_QUERY].desc = "sticky buffer to match DNS query-buffer";
+    sigmatch_table[DETECT_AL_DNS_QUERY].url = "/rules/dns-keywords.html#dns-query";
+    sigmatch_table[DETECT_AL_DNS_QUERY].Setup = DetectDnsQuerySetup;
+#ifdef UNITTESTS
+    sigmatch_table[DETECT_AL_DNS_QUERY].RegisterTests = DetectDnsQueryRegisterTests;
+#endif
+    sigmatch_table[DETECT_AL_DNS_QUERY].flags |= SIGMATCH_NOOPT;
+    sigmatch_table[DETECT_AL_DNS_QUERY].flags |= SIGMATCH_INFO_STICKY_BUFFER;
+
+    DetectAppLayerMpmRegister2("dns_query", SIG_FLAG_TOSERVER, 2,
+            PrefilterMpmDnsQueryRegister, NULL,
+            ALPROTO_DNS, 1);
+
+    DetectAppLayerInspectEngineRegister2("dns_query",
+            ALPROTO_DNS, SIG_FLAG_TOSERVER, 1,
+            DetectEngineInspectDnsQuery, NULL);
+
+    DetectBufferTypeSetDescriptionByName("dns_query",
+            "dns request query");
+    DetectBufferTypeSupportsMultiInstance("dns_query");
+
+    g_dns_query_buffer_id = DetectBufferTypeGetByName("dns_query");
+
+#ifdef HAVE_LUA
+    /* register these generic engines from here for now */
+    DetectAppLayerInspectEngineRegister2(
+            "dns_request", ALPROTO_DNS, SIG_FLAG_TOSERVER, 1, DetectEngineInspectGenericList, NULL);
+    DetectAppLayerInspectEngineRegister2("dns_response", ALPROTO_DNS, SIG_FLAG_TOCLIENT, 1,
+            DetectEngineInspectGenericList, NULL);
+
+    DetectBufferTypeSetDescriptionByName("dns_request",
+            "dns requests");
+    DetectBufferTypeSetDescriptionByName("dns_response",
+            "dns responses");
+#endif
+}
+
+
+/**
+ * \brief setup the dns_query sticky buffer keyword used in the rule
+ *
+ * \param de_ctx   Pointer to the Detection Engine Context
+ * \param s        Pointer to the Signature to which the current keyword belongs
+ * \param str      Should hold an empty string always
+ *
+ * \retval  0 On success
+ * \retval -1 On failure
+ */
+
+static int DetectDnsQuerySetup(DetectEngineCtx *de_ctx, Signature *s, const char *str)
+{
+    if (DetectBufferSetActiveList(de_ctx, s, g_dns_query_buffer_id) < 0)
+        return -1;
+    if (DetectSignatureSetAppProto(s, ALPROTO_DNS) < 0)
+        return -1;
+    return 0;
+}
+
+#ifdef UNITTESTS
+#include "detect-isdataat.h"
+#include "detect-engine-alert.h"
+
+/** \test simple google.com query matching */
+static int DetectDnsQueryTest01(void)
+{
+    /* google.com */
+    uint8_t buf[] = {   0x10, 0x32, 0x01, 0x00, 0x00, 0x01,
+                        0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                        0x06, 0x67, 0x6F, 0x6F, 0x67, 0x6C,
+                        0x65, 0x03, 0x63, 0x6F, 0x6D, 0x00,
+                        0x00, 0x10, 0x00, 0x01, };
+    Flow f;
+    void *dns_state = NULL;
+    Packet *p = NULL;
+    Signature *s = NULL;
+    ThreadVars tv;
+    DetectEngineThreadCtx *det_ctx = NULL;
+    AppLayerParserThreadCtx *alp_tctx = AppLayerParserThreadCtxAlloc();
+
+    memset(&tv, 0, sizeof(ThreadVars));
+    memset(&f, 0, sizeof(Flow));
+
+    p = UTHBuildPacketReal(buf, sizeof(buf), IPPROTO_UDP,
+                           "192.168.1.5", "192.168.1.1",
+                           41424, 53);
+
+    FLOW_INITIALIZE(&f);
+    f.flags |= FLOW_IPV4;
+    f.proto = IPPROTO_UDP;
+    f.protomap = FlowGetProtoMapping(f.proto);
+
+    p->flow = &f;
+    p->flags |= PKT_HAS_FLOW;
+    p->flowflags |= FLOW_PKT_TOSERVER;
+    f.alproto = ALPROTO_DNS;
+
+    DetectEngineCtx *de_ctx = DetectEngineCtxInit();
+    FAIL_IF_NULL(de_ctx);
+    de_ctx->mpm_matcher = mpm_default_matcher;
+    de_ctx->flags |= DE_QUIET;
+
+    s = DetectEngineAppendSig(de_ctx, "alert dns any any -> any any "
+                              "(msg:\"Test dns_query option\"; "
+                              "dns_query; content:\"google\"; nocase; sid:1;)");
+    FAIL_IF_NULL(s);
+
+    SigGroupBuild(de_ctx);
+    DetectEngineThreadCtxInit(&tv, (void *)de_ctx, (void *)&det_ctx);
+
+    int r = AppLayerParserParse(NULL, alp_tctx, &f, ALPROTO_DNS,
+                                STREAM_TOSERVER, buf, sizeof(buf));
+    if (r != 0) {
+        printf("toserver chunk 1 returned %" PRId32 ", expected 0: ", r);
+        FAIL;
+    }
+
+    dns_state = f.alstate;
+    FAIL_IF_NULL(dns_state);
+
+    /* do detect */
+    SigMatchSignatures(&tv, de_ctx, det_ctx, p);
+
+    if (!(PacketAlertCheck(p, 1))) {
+        printf("sig 1 didn't alert, but it should have: ");
+        FAIL;
+    }
+
+    if (alp_tctx != NULL)
+        AppLayerParserThreadCtxFree(alp_tctx);
+    if (det_ctx != NULL)
+        DetectEngineThreadCtxDeinit(&tv, det_ctx);
+    if (de_ctx != NULL)
+        SigGroupCleanup(de_ctx);
+    if (de_ctx != NULL)
+        DetectEngineCtxFree(de_ctx);
+
+    FLOW_DESTROY(&f);
+    UTHFreePacket(p);
+    PASS;
+}
+
+/** \test multi tx google.(com|net) query matching */
+static int DetectDnsQueryTest02(void)
+{
+    /* google.com */
+    uint8_t buf1[] = {  0x10, 0x32, 0x01, 0x00, 0x00, 0x01,
+                        0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                        0x06, 0x67, 0x6F, 0x6F, 0x67, 0x6C,
+                        0x65, 0x03, 0x63, 0x6F, 0x6D, 0x00,
+                        0x00, 0x01, 0x00, 0x01, };
+
+    uint8_t buf2[] = {  0x10, 0x32,                             /* tx id */
+                        0x81, 0x80,                             /* flags: resp, recursion desired, recursion available */
+                        0x00, 0x01,                             /* 1 query */
+                        0x00, 0x01,                             /* 1 answer */
+                        0x00, 0x00, 0x00, 0x00,                 /* no auth rr, additional rr */
+                        /* query record */
+                        0x06, 0x67, 0x6F, 0x6F, 0x67, 0x6C,     /* name */
+                        0x65, 0x03, 0x63, 0x6F, 0x6D, 0x00,     /* name cont */
+                        0x00, 0x01, 0x00, 0x01,                 /* type a, class in */
+                        /* answer */
+                        0xc0, 0x0c,                             /* ref to name in query above */
+                        0x00, 0x01, 0x00, 0x01,                 /* type a, class in */
+                        0x00, 0x01, 0x40, 0xef,                 /* ttl */
+                        0x00, 0x04,                             /* data len */
+                        0x01, 0x02, 0x03, 0x04 };               /* addr */
+
+    /* google.net */
+    uint8_t buf3[] = {  0x11, 0x33, 0x01, 0x00, 0x00, 0x01,
+                        0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                        0x06, 0x67, 0x6F, 0x6F, 0x67, 0x6C,
+                        0x65, 0x03, 0x6E, 0x65, 0x74, 0x00,
+                        0x00, 0x10, 0x00, 0x01, };
+    Flow f;
+    void *dns_state = NULL;
+    Packet *p1 = NULL, *p2 = NULL, *p3 = NULL;
+    Signature *s = NULL;
+    ThreadVars tv;
+    DetectEngineThreadCtx *det_ctx = NULL;
+    AppLayerParserThreadCtx *alp_tctx = AppLayerParserThreadCtxAlloc();
+
+    memset(&tv, 0, sizeof(ThreadVars));
+    memset(&f, 0, sizeof(Flow));
+
+    p1 = UTHBuildPacketReal(buf1, sizeof(buf1), IPPROTO_UDP,
+                           "192.168.1.5", "192.168.1.1",
+                           41424, 53);
+    p2 = UTHBuildPacketReal(buf1, sizeof(buf1), IPPROTO_UDP,
+                           "192.168.1.5", "192.168.1.1",
+                           41424, 53);
+    p3 = UTHBuildPacketReal(buf1, sizeof(buf1), IPPROTO_UDP,
+                           "192.168.1.5", "192.168.1.1",
+                           41424, 53);
+
+    FLOW_INITIALIZE(&f);
+    f.flags |= FLOW_IPV4;
+    f.proto = IPPROTO_UDP;
+    f.protomap = FlowGetProtoMapping(f.proto);
+    f.alproto = ALPROTO_DNS;
+
+    p1->flow = &f;
+    p1->flags |= PKT_HAS_FLOW;
+    p1->flowflags |= FLOW_PKT_TOSERVER;
+    p1->pcap_cnt = 1;
+
+    p2->flow = &f;
+    p2->flags |= PKT_HAS_FLOW;
+    p2->flowflags |= FLOW_PKT_TOCLIENT;
+    p2->pcap_cnt = 2;
+
+    p3->flow = &f;
+    p3->flags |= PKT_HAS_FLOW;
+    p3->flowflags |= FLOW_PKT_TOSERVER;
+    p3->pcap_cnt = 3;
+
+    DetectEngineCtx *de_ctx = DetectEngineCtxInit();
+    FAIL_IF_NULL(de_ctx);
+    de_ctx->mpm_matcher = mpm_default_matcher;
+    de_ctx->flags |= DE_QUIET;
+
+    s = DetectEngineAppendSig(de_ctx, "alert dns any any -> any any "
+                              "(msg:\"Test dns_query option\"; "
+                              "dns_query; content:\"google.com\"; nocase; sid:1;)");
+    FAIL_IF_NULL(s);
+    s = DetectEngineAppendSig(de_ctx, "alert dns any any -> any any "
+                              "(msg:\"Test dns_query option\"; "
+                              "dns_query; content:\"google.net\"; nocase; sid:2;)");
+    FAIL_IF_NULL(s);
+
+    SigGroupBuild(de_ctx);
+    DetectEngineThreadCtxInit(&tv, (void *)de_ctx, (void *)&det_ctx);
+
+    int r = AppLayerParserParse(NULL, alp_tctx, &f, ALPROTO_DNS,
+                                STREAM_TOSERVER, buf1, sizeof(buf1));
+    if (r != 0) {
+        printf("toserver chunk 1 returned %" PRId32 ", expected 0: ", r);
+        FAIL;
+    }
+
+    dns_state = f.alstate;
+    FAIL_IF_NULL(dns_state);
+
+    /* do detect */
+    SigMatchSignatures(&tv, de_ctx, det_ctx, p1);
+
+    if (!(PacketAlertCheck(p1, 1))) {
+        printf("(p1) sig 1 didn't alert, but it should have: ");
+        FAIL;
+    }
+    if (PacketAlertCheck(p1, 2)) {
+        printf("(p1) sig 2 did alert, but it should not have: ");
+        FAIL;
+    }
+
+    r = AppLayerParserParse(NULL, alp_tctx, &f, ALPROTO_DNS, STREAM_TOCLIENT,
+                            buf2, sizeof(buf2));
+    if (r != 0) {
+        printf("toserver client 1 returned %" PRId32 ", expected 0: ", r);
+        FAIL;
+    }
+
+    /* do detect */
+    SigMatchSignatures(&tv, de_ctx, det_ctx, p2);
+
+    if (PacketAlertCheck(p2, 1)) {
+        printf("(p2) sig 1 alerted, but it should not have: ");
+        FAIL;
+    }
+    if (PacketAlertCheck(p2, 2)) {
+        printf("(p2) sig 2 alerted, but it should not have: ");
+        FAIL;
+    }
+
+    r = AppLayerParserParse(NULL, alp_tctx, &f, ALPROTO_DNS, STREAM_TOSERVER,
+                            buf3, sizeof(buf3));
+    if (r != 0) {
+        printf("toserver chunk 3 returned %" PRId32 ", expected 0: ", r);
+        FAIL;
+    }
+
+    /* do detect */
+    SigMatchSignatures(&tv, de_ctx, det_ctx, p3);
+
+    if (PacketAlertCheck(p3, 1)) {
+        printf("(p3) sig 1 alerted, but it should not have: ");
+        FAIL;
+    }
+    if (!(PacketAlertCheck(p3, 2))) {
+        printf("(p3) sig 2 didn't alert, but it should have: ");
+        FAIL;
+    }
+
+    if (alp_tctx != NULL)
+        AppLayerParserThreadCtxFree(alp_tctx);
+    if (det_ctx != NULL)
+        DetectEngineThreadCtxDeinit(&tv, det_ctx);
+    if (de_ctx != NULL)
+        SigGroupCleanup(de_ctx);
+    if (de_ctx != NULL)
+        DetectEngineCtxFree(de_ctx);
+
+    FLOW_DESTROY(&f);
+    UTHFreePacket(p1);
+    UTHFreePacket(p2);
+    UTHFreePacket(p3);
+    PASS;
+}
+
+/** \test simple google.com query matching (TCP) */
+static int DetectDnsQueryTest03(void)
+{
+    /* google.com */
+    uint8_t buf[] = {   0x00, 28,
+                        0x10, 0x32, 0x01, 0x00, 0x00, 0x01,
+                        0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                        0x06, 0x67, 0x6F, 0x6F, 0x67, 0x6C,
+                        0x65, 0x03, 0x63, 0x6F, 0x6D, 0x00,
+                        0x00, 0x10, 0x00, 0x01, };
+    Flow f;
+    void *dns_state = NULL;
+    Packet *p = NULL;
+    Signature *s = NULL;
+    ThreadVars tv;
+    DetectEngineThreadCtx *det_ctx = NULL;
+    TcpSession ssn;
+    AppLayerParserThreadCtx *alp_tctx = AppLayerParserThreadCtxAlloc();
+
+    memset(&tv, 0, sizeof(ThreadVars));
+    memset(&f, 0, sizeof(Flow));
+    memset(&ssn, 0, sizeof(TcpSession));
+
+    p = UTHBuildPacketReal(buf, sizeof(buf), IPPROTO_TCP,
+                           "192.168.1.5", "192.168.1.1",
+                           41424, 53);
+
+    FLOW_INITIALIZE(&f);
+    f.protoctx = (void *)&ssn;
+    f.flags |= FLOW_IPV4;
+    f.proto = IPPROTO_TCP;
+    f.protomap = FlowGetProtoMapping(f.proto);
+
+    p->flow = &f;
+    p->flags |= PKT_HAS_FLOW|PKT_STREAM_EST;
+    p->flowflags |= FLOW_PKT_TOSERVER|FLOW_PKT_ESTABLISHED;
+    f.alproto = ALPROTO_DNS;
+
+    StreamTcpInitConfig(true);
+
+    DetectEngineCtx *de_ctx = DetectEngineCtxInit();
+    FAIL_IF_NULL(de_ctx);
+    de_ctx->mpm_matcher = mpm_default_matcher;
+    de_ctx->flags |= DE_QUIET;
+
+    s = DetectEngineAppendSig(de_ctx, "alert dns any any -> any any "
+                              "(msg:\"Test dns_query option\"; "
+                              "dns_query; content:\"google\"; nocase; sid:1;)");
+    FAIL_IF_NULL(s);
+
+    SigGroupBuild(de_ctx);
+    DetectEngineThreadCtxInit(&tv, (void *)de_ctx, (void *)&det_ctx);
+
+    int r = AppLayerParserParse(NULL, alp_tctx, &f, ALPROTO_DNS,
+                                STREAM_TOSERVER, buf, sizeof(buf));
+    if (r != 0) {
+        printf("toserver chunk 1 returned %" PRId32 ", expected 0: ", r);
+        FAIL;
+    }
+
+    dns_state = f.alstate;
+    FAIL_IF_NULL(dns_state);
+
+    /* do detect */
+    SigMatchSignatures(&tv, de_ctx, det_ctx, p);
+
+    if (!(PacketAlertCheck(p, 1))) {
+        printf("sig 1 didn't alert, but it should have: ");
+        FAIL;
+    }
+
+    if (alp_tctx != NULL)
+        AppLayerParserThreadCtxFree(alp_tctx);
+    if (det_ctx != NULL)
+        DetectEngineThreadCtxDeinit(&tv, det_ctx);
+    if (de_ctx != NULL)
+        SigGroupCleanup(de_ctx);
+    if (de_ctx != NULL)
+        DetectEngineCtxFree(de_ctx);
+
+    StreamTcpFreeConfig(true);
+    FLOW_DESTROY(&f);
+    UTHFreePacket(p);
+    PASS;
+}
+
+
+/** \test simple google.com query matching, pcre */
+static int DetectDnsQueryTest04(void)
+{
+    /* google.com */
+    uint8_t buf[] = {   0x10, 0x32, 0x01, 0x00, 0x00, 0x01,
+                        0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                        0x06, 0x67, 0x6F, 0x6F, 0x67, 0x6C,
+                        0x65, 0x03, 0x63, 0x6F, 0x6D, 0x00,
+                        0x00, 0x10, 0x00, 0x01, };
+    Flow f;
+    void *dns_state = NULL;
+    Packet *p = NULL;
+    Signature *s = NULL;
+    ThreadVars tv;
+    DetectEngineThreadCtx *det_ctx = NULL;
+    AppLayerParserThreadCtx *alp_tctx = AppLayerParserThreadCtxAlloc();
+
+    memset(&tv, 0, sizeof(ThreadVars));
+    memset(&f, 0, sizeof(Flow));
+
+    p = UTHBuildPacketReal(buf, sizeof(buf), IPPROTO_UDP,
+                           "192.168.1.5", "192.168.1.1",
+                           41424, 53);
+
+    FLOW_INITIALIZE(&f);
+    f.flags |= FLOW_IPV4;
+    f.proto = IPPROTO_UDP;
+    f.protomap = FlowGetProtoMapping(f.proto);
+
+    p->flow = &f;
+    p->flags |= PKT_HAS_FLOW;
+    p->flowflags |= FLOW_PKT_TOSERVER;
+    f.alproto = ALPROTO_DNS;
+
+    DetectEngineCtx *de_ctx = DetectEngineCtxInit();
+    FAIL_IF_NULL(de_ctx);
+    de_ctx->mpm_matcher = mpm_default_matcher;
+    de_ctx->flags |= DE_QUIET;
+
+    s = DetectEngineAppendSig(de_ctx, "alert dns any any -> any any "
+                              "(msg:\"Test dns_query option\"; "
+                              "dns_query; content:\"google\"; nocase; "
+                              "pcre:\"/google\\.com$/i\"; sid:1;)");
+    FAIL_IF_NULL(s);
+    s = DetectEngineAppendSig(de_ctx, "alert dns any any -> any any "
+                                      "(msg:\"Test dns_query option\"; "
+                                      "dns_query; content:\"google\"; nocase; "
+                                      "pcre:\"/^\\.[a-z]{2,3}$/iR\"; sid:2;)");
+    FAIL_IF_NULL(s);
+
+    SigGroupBuild(de_ctx);
+    DetectEngineThreadCtxInit(&tv, (void *)de_ctx, (void *)&det_ctx);
+
+    int r = AppLayerParserParse(NULL, alp_tctx, &f, ALPROTO_DNS,
+                                STREAM_TOSERVER, buf, sizeof(buf));
+    if (r != 0) {
+        printf("toserver chunk 1 returned %" PRId32 ", expected 0: ", r);
+        FAIL;
+    }
+
+    dns_state = f.alstate;
+    FAIL_IF_NULL(dns_state);
+
+    /* do detect */
+    SigMatchSignatures(&tv, de_ctx, det_ctx, p);
+
+    if (!(PacketAlertCheck(p, 1))) {
+        printf("sig 1 didn't alert, but it should have: ");
+        FAIL;
+    }
+    if (!(PacketAlertCheck(p, 2))) {
+        printf("sig 2 didn't alert, but it should have: ");
+        FAIL;
+    }
+
+    if (alp_tctx != NULL)
+        AppLayerParserThreadCtxFree(alp_tctx);
+    if (det_ctx != NULL)
+        DetectEngineThreadCtxDeinit(&tv, det_ctx);
+    if (de_ctx != NULL)
+        SigGroupCleanup(de_ctx);
+    if (de_ctx != NULL)
+        DetectEngineCtxFree(de_ctx);
+
+    FLOW_DESTROY(&f);
+    UTHFreePacket(p);
+    PASS;
+}
+
+/** \test multi tx google.(com|net) query matching +
+ *        app layer event */
+static int DetectDnsQueryTest05(void)
+{
+    /* google.com */
+    uint8_t buf1[] = {  0x10, 0x32, 0x01, 0x00, 0x00, 0x01,
+                        0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                        0x06, 0x67, 0x6F, 0x6F, 0x67, 0x6C,
+                        0x65, 0x03, 0x63, 0x6F, 0x6D, 0x00,
+                        0x00, 0x01, 0x00, 0x01, };
+
+    uint8_t buf2[] = {  0x10, 0x32,                             /* tx id */
+                        0x81, 0x80|0x40,                        /* flags: resp, recursion desired, recursion available */
+                        0x00, 0x01,                             /* 1 query */
+                        0x00, 0x01,                             /* 1 answer */
+                        0x00, 0x00, 0x00, 0x00,                 /* no auth rr, additional rr */
+                        /* query record */
+                        0x06, 0x67, 0x6F, 0x6F, 0x67, 0x6C,     /* name */
+                        0x65, 0x03, 0x63, 0x6F, 0x6D, 0x00,     /* name cont */
+                        0x00, 0x01, 0x00, 0x01,                 /* type a, class in */
+                        /* answer */
+                        0xc0, 0x0c,                             /* ref to name in query above */
+                        0x00, 0x01, 0x00, 0x01,                 /* type a, class in */
+                        0x00, 0x01, 0x40, 0xef,                 /* ttl */
+                        0x00, 0x04,                             /* data len */
+                        0x01, 0x02, 0x03, 0x04 };               /* addr */
+
+    /* google.net */
+    uint8_t buf3[] = {  0x11, 0x33, 0x01, 0x00, 0x00, 0x01,
+                        0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                        0x06, 0x67, 0x6F, 0x6F, 0x67, 0x6C,
+                        0x65, 0x03, 0x6E, 0x65, 0x74, 0x00,
+                        0x00, 0x10, 0x00, 0x01, };
+    Flow f;
+    void *dns_state = NULL;
+    Packet *p1 = NULL, *p2 = NULL, *p3 = NULL;
+    Signature *s = NULL;
+    ThreadVars tv;
+    DetectEngineThreadCtx *det_ctx = NULL;
+    AppLayerParserThreadCtx *alp_tctx = AppLayerParserThreadCtxAlloc();
+
+    memset(&tv, 0, sizeof(ThreadVars));
+    memset(&f, 0, sizeof(Flow));
+
+    p1 = UTHBuildPacketReal(buf1, sizeof(buf1), IPPROTO_UDP,
+                            "192.168.1.5", "192.168.1.1",
+                            41424, 53);
+    p2 = UTHBuildPacketReal(buf2, sizeof(buf2), IPPROTO_UDP,
+                            "192.168.1.5", "192.168.1.1",
+                            41424, 53);
+    p3 = UTHBuildPacketReal(buf3, sizeof(buf3), IPPROTO_UDP,
+                            "192.168.1.5", "192.168.1.1",
+                            41424, 53);
+
+    FLOW_INITIALIZE(&f);
+    f.flags |= FLOW_IPV4;
+    f.proto = IPPROTO_UDP;
+    f.protomap = FlowGetProtoMapping(f.proto);
+    f.alproto = ALPROTO_DNS;
+
+    p1->flow = &f;
+    p1->flags |= PKT_HAS_FLOW;
+    p1->flowflags |= FLOW_PKT_TOSERVER;
+    p1->pcap_cnt = 1;
+
+    p2->flow = &f;
+    p2->flags |= PKT_HAS_FLOW;
+    p2->flowflags |= FLOW_PKT_TOCLIENT;
+    p2->pcap_cnt = 2;
+
+    p3->flow = &f;
+    p3->flags |= PKT_HAS_FLOW;
+    p3->flowflags |= FLOW_PKT_TOSERVER;
+    p3->pcap_cnt = 3;
+
+    DetectEngineCtx *de_ctx = DetectEngineCtxInit();
+    FAIL_IF_NULL(de_ctx);
+    de_ctx->mpm_matcher = mpm_default_matcher;
+    de_ctx->flags |= DE_QUIET;
+
+    s = DetectEngineAppendSig(de_ctx, "alert dns any any -> any any "
+                                   "(msg:\"Test dns_query option\"; "
+                                   "dns_query; content:\"google.com\"; nocase; sid:1;)");
+    FAIL_IF_NULL(s);
+    s = DetectEngineAppendSig(de_ctx, "alert dns any any -> any any "
+                                   "(msg:\"Test dns_query option\"; "
+                                   "dns_query; content:\"google.net\"; nocase; sid:2;)");
+    FAIL_IF_NULL(s);
+    s = DetectEngineAppendSig(de_ctx, "alert dns any any -> any any "
+                                   "(msg:\"Test Z flag event\"; "
+                                   "app-layer-event:dns.z_flag_set; sid:3;)");
+    FAIL_IF_NULL(s);
+
+    SigGroupBuild(de_ctx);
+    DetectEngineThreadCtxInit(&tv, (void *)de_ctx, (void *)&det_ctx);
+
+    int r = AppLayerParserParse(NULL, alp_tctx, &f, ALPROTO_DNS,
+                                STREAM_TOSERVER, buf1, sizeof(buf1));
+    if (r != 0) {
+        printf("toserver chunk 1 returned %" PRId32 ", expected 0: ", r);
+        FAIL;
+    }
+
+    dns_state = f.alstate;
+    FAIL_IF_NULL(dns_state);
+
+    /* do detect */
+    SigMatchSignatures(&tv, de_ctx, det_ctx, p1);
+
+    if (!(PacketAlertCheck(p1, 1))) {
+        printf("(p1) sig 1 didn't alert, but it should have: ");
+        FAIL;
+    }
+    if (PacketAlertCheck(p1, 2)) {
+        printf("(p1) sig 2 did alert, but it should not have: ");
+        FAIL;
+    }
+
+    r = AppLayerParserParse(NULL, alp_tctx, &f, ALPROTO_DNS, STREAM_TOCLIENT,
+                            buf2, sizeof(buf2));
+    if (r != 0) {
+        printf("toserver client 1 returned %" PRId32 ", expected 0\n", r);
+        FAIL;
+    }
+
+    /* do detect */
+    SigMatchSignatures(&tv, de_ctx, det_ctx, p2);
+
+    if (PacketAlertCheck(p2, 1)) {
+        printf("(p2) sig 1 alerted, but it should not have: ");
+        FAIL;
+    }
+    if (PacketAlertCheck(p2, 2)) {
+        printf("(p2) sig 2 alerted, but it should not have: ");
+        FAIL;
+    }
+    if (!(PacketAlertCheck(p2, 3))) {
+        printf("(p2) sig 3 didn't alert, but it should have: ");
+        FAIL;
+    }
+
+    r = AppLayerParserParse(NULL, alp_tctx, &f, ALPROTO_DNS, STREAM_TOSERVER,
+                            buf3, sizeof(buf3));
+    if (r != 0) {
+        printf("toserver chunk 3 returned %" PRId32 ", expected 0: ", r);
+        FAIL;
+    }
+
+    /* do detect */
+    SigMatchSignatures(&tv, de_ctx, det_ctx, p3);
+
+    if (PacketAlertCheck(p3, 1)) {
+        printf("(p3) sig 1 alerted, but it should not have: ");
+        FAIL;
+    }
+    if (!(PacketAlertCheck(p3, 2))) {
+        printf("(p3) sig 2 didn't alert, but it should have: ");
+        FAIL;
+    }
+    /** \todo should not alert, bug #839
+    if (PacketAlertCheck(p3, 3)) {
+        printf("(p3) sig 3 did alert, but it should not have: ");
+        goto end;
+    }
+    */
+
+    if (alp_tctx != NULL)
+        AppLayerParserThreadCtxFree(alp_tctx);
+    if (det_ctx != NULL)
+        DetectEngineThreadCtxDeinit(&tv, det_ctx);
+    if (de_ctx != NULL)
+        SigGroupCleanup(de_ctx);
+    if (de_ctx != NULL)
+        DetectEngineCtxFree(de_ctx);
+
+    FLOW_DESTROY(&f);
+    UTHFreePacket(p1);
+    UTHFreePacket(p2);
+    UTHFreePacket(p3);
+    PASS;
+}
+
+static void DetectDnsQueryRegisterTests(void)
+{
+    UtRegisterTest("DetectDnsQueryTest01", DetectDnsQueryTest01);
+    UtRegisterTest("DetectDnsQueryTest02", DetectDnsQueryTest02);
+    UtRegisterTest("DetectDnsQueryTest03 -- tcp", DetectDnsQueryTest03);
+    UtRegisterTest("DetectDnsQueryTest04 -- pcre", DetectDnsQueryTest04);
+    UtRegisterTest("DetectDnsQueryTest05 -- app layer event", DetectDnsQueryTest05);
+}
+#endif