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, 302 insertions, 0 deletions

diff --git a/src/detect-tcp-seq.c b/src/detect-tcp-seq.c
new file mode 100644
index 0000000..20d7c6d
--- /dev/null
+++ b/src/detect-tcp-seq.c
@@ -0,0 +1,302 @@
+/* Copyright (C) 2007-2010 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 Brian Rectanus <brectanu@gmail.com>
+ *
+ * Implements the seq keyword.
+ */
+
+#include "suricata-common.h"
+#include "decode.h"
+#include "detect.h"
+
+#include "detect-parse.h"
+#include "detect-engine.h"
+#include "detect-engine-prefilter.h"
+#include "detect-engine-prefilter-common.h"
+#include "detect-engine-build.h"
+
+#include "detect-tcp-seq.h"
+
+#include "util-byte.h"
+#include "util-unittest.h"
+#include "util-unittest-helper.h"
+#include "util-debug.h"
+
+static int DetectSeqSetup(DetectEngineCtx *, Signature *, const char *);
+static int DetectSeqMatch(DetectEngineThreadCtx *,
+                          Packet *, const Signature *, const SigMatchCtx *);
+#ifdef UNITTESTS
+static void DetectSeqRegisterTests(void);
+#endif
+static void DetectSeqFree(DetectEngineCtx *, void *);
+static int PrefilterSetupTcpSeq(DetectEngineCtx *de_ctx, SigGroupHead *sgh);
+static bool PrefilterTcpSeqIsPrefilterable(const Signature *s);
+
+void DetectSeqRegister(void)
+{
+    sigmatch_table[DETECT_SEQ].name = "tcp.seq";
+    sigmatch_table[DETECT_SEQ].alias = "seq";
+    sigmatch_table[DETECT_SEQ].desc = "check for a specific TCP sequence number";
+    sigmatch_table[DETECT_SEQ].url = "/rules/header-keywords.html#seq";
+    sigmatch_table[DETECT_SEQ].Match = DetectSeqMatch;
+    sigmatch_table[DETECT_SEQ].Setup = DetectSeqSetup;
+    sigmatch_table[DETECT_SEQ].Free = DetectSeqFree;
+#ifdef UNITTESTS
+    sigmatch_table[DETECT_SEQ].RegisterTests = DetectSeqRegisterTests;
+#endif
+    sigmatch_table[DETECT_SEQ].SupportsPrefilter = PrefilterTcpSeqIsPrefilterable;
+    sigmatch_table[DETECT_SEQ].SetupPrefilter = PrefilterSetupTcpSeq;
+}
+
+/**
+ * \internal
+ * \brief This function is used to match packets with a given Seq number
+ *
+ * \param t pointer to thread vars
+ * \param det_ctx pointer to the pattern matcher thread
+ * \param p pointer to the current packet
+ * \param m pointer to the sigmatch that we will cast into DetectSeqData
+ *
+ * \retval 0 no match
+ * \retval 1 match
+ */
+static int DetectSeqMatch(DetectEngineThreadCtx *det_ctx,
+                          Packet *p, const Signature *s, const SigMatchCtx *ctx)
+{
+    const DetectSeqData *data = (const DetectSeqData *)ctx;
+
+    /* This is only needed on TCP packets */
+    if (!(PKT_IS_TCP(p)) || PKT_IS_PSEUDOPKT(p)) {
+        return 0;
+    }
+
+    return (data->seq == TCP_GET_SEQ(p)) ? 1 : 0;
+}
+
+/**
+ * \internal
+ * \brief this function is used to add the seq option into the signature
+ *
+ * \param de_ctx pointer to the Detection Engine Context
+ * \param s pointer to the Current Signature
+ * \param optstr pointer to the user provided options
+ *
+ * \retval 0 on Success
+ * \retval -1 on Failure
+ */
+static int DetectSeqSetup (DetectEngineCtx *de_ctx, Signature *s, const char *optstr)
+{
+    DetectSeqData *data = NULL;
+    SigMatch *sm = NULL;
+
+    data = SCMalloc(sizeof(DetectSeqData));
+    if (unlikely(data == NULL))
+        goto error;
+
+    sm = SigMatchAlloc();
+    if (sm == NULL)
+        goto error;
+
+    sm->type = DETECT_SEQ;
+
+    if (StringParseUint32(&data->seq, 10, 0, optstr) < 0) {
+        goto error;
+    }
+    sm->ctx = (SigMatchCtx*)data;
+
+    SigMatchAppendSMToList(s, sm, DETECT_SM_LIST_MATCH);
+    s->flags |= SIG_FLAG_REQUIRE_PACKET;
+
+    return 0;
+
+error:
+    if (data)
+        SCFree(data);
+    if (sm)
+        SigMatchFree(de_ctx, sm);
+    return -1;
+
+}
+
+/**
+ * \internal
+ * \brief this function will free memory associated with seq option
+ *
+ * \param data pointer to seq configuration data
+ */
+static void DetectSeqFree(DetectEngineCtx *de_ctx, void *ptr)
+{
+    DetectSeqData *data = (DetectSeqData *)ptr;
+    SCFree(data);
+}
+
+/* prefilter code */
+
+static void
+PrefilterPacketSeqMatch(DetectEngineThreadCtx *det_ctx, Packet *p, const void *pectx)
+{
+    const PrefilterPacketHeaderCtx *ctx = pectx;
+
+    if (!PrefilterPacketHeaderExtraMatch(ctx, p))
+        return;
+
+    if ((p->proto) == IPPROTO_TCP && !(PKT_IS_PSEUDOPKT(p)) &&
+        (p->tcph != NULL) && (TCP_GET_SEQ(p) == ctx->v1.u32[0]))
+    {
+        SCLogDebug("packet matches TCP seq %u", ctx->v1.u32[0]);
+        PrefilterAddSids(&det_ctx->pmq, ctx->sigs_array, ctx->sigs_cnt);
+    }
+}
+
+static void
+PrefilterPacketSeqSet(PrefilterPacketHeaderValue *v, void *smctx)
+{
+    const DetectSeqData *a = smctx;
+    v->u32[0] = a->seq;
+}
+
+static bool
+PrefilterPacketSeqCompare(PrefilterPacketHeaderValue v, void *smctx)
+{
+    const DetectSeqData *a = smctx;
+    if (v.u32[0] == a->seq)
+        return true;
+    return false;
+}
+
+static int PrefilterSetupTcpSeq(DetectEngineCtx *de_ctx, SigGroupHead *sgh)
+{
+    return PrefilterSetupPacketHeader(de_ctx, sgh, DETECT_SEQ,
+        PrefilterPacketSeqSet,
+        PrefilterPacketSeqCompare,
+        PrefilterPacketSeqMatch);
+}
+
+static bool PrefilterTcpSeqIsPrefilterable(const Signature *s)
+{
+    const SigMatch *sm;
+    for (sm = s->init_data->smlists[DETECT_SM_LIST_MATCH] ; sm != NULL; sm = sm->next) {
+        switch (sm->type) {
+            case DETECT_SEQ:
+                return true;
+        }
+    }
+    return false;
+}
+
+
+#ifdef UNITTESTS
+
+/**
+ * \test DetectSeqSigTest01 tests parses
+ */
+static int DetectSeqSigTest01(void)
+{
+    int result = 0;
+    DetectEngineCtx *de_ctx = DetectEngineCtxInit();
+    if (de_ctx == NULL)
+        goto end;
+
+    /* These three are crammed in here as there is no Parse */
+    if (SigInit(de_ctx,
+                "alert tcp any any -> any any "
+                "(msg:\"Testing seq\";seq:foo;sid:1;)") != NULL)
+    {
+        printf("invalid seq accepted: ");
+        goto cleanup;
+    }
+    if (SigInit(de_ctx,
+                "alert tcp any any -> any any "
+                "(msg:\"Testing seq\";seq:9999999999;sid:1;)") != NULL)
+    {
+        printf("overflowing seq accepted: ");
+        goto cleanup;
+    }
+    if (SigInit(de_ctx,
+                "alert tcp any any -> any any "
+                "(msg:\"Testing seq\";seq:-100;sid:1;)") != NULL)
+    {
+        printf("negative seq accepted: ");
+        goto cleanup;
+    }
+    result = 1;
+
+cleanup:
+    if (de_ctx) {
+        SigGroupCleanup(de_ctx);
+        SigCleanSignatures(de_ctx);
+        DetectEngineCtxFree(de_ctx);
+    }
+end:
+    return result;
+}
+
+/**
+ * \test DetectSeqSigTest02 tests seq keyword
+ */
+static int DetectSeqSigTest02(void)
+{
+    int result = 0;
+    uint8_t *buf = (uint8_t *)"Hi all!";
+    uint16_t buflen = strlen((char *)buf);
+    Packet *p[3];
+    p[0] = UTHBuildPacket((uint8_t *)buf, buflen, IPPROTO_TCP);
+    p[1] = UTHBuildPacket((uint8_t *)buf, buflen, IPPROTO_TCP);
+    p[2] = UTHBuildPacket((uint8_t *)buf, buflen, IPPROTO_ICMP);
+    if (p[0] == NULL || p[1] == NULL ||p[2] == NULL)
+        goto end;
+
+    /* TCP w/seq=42 */
+    p[0]->tcph->th_seq = htonl(42);
+
+    /* TCP w/seq=100 */
+    p[1]->tcph->th_seq = htonl(100);
+
+    const char *sigs[2];
+    sigs[0]= "alert tcp any any -> any any (msg:\"Testing seq\"; seq:41; sid:1;)";
+    sigs[1]= "alert tcp any any -> any any (msg:\"Testing seq\"; seq:42; sid:2;)";
+
+    uint32_t sid[2] = {1, 2};
+
+    uint32_t results[3][2] = {
+                              /* packet 0 match sid 1 but should not match sid 2 */
+                              {0, 1},
+                              /* packet 1 should not match */
+                              {0, 0},
+                              /* packet 2 should not match */
+                              {0, 0} };
+
+    result = UTHGenericTest(p, 3, sigs, sid, (uint32_t *) results, 2);
+    UTHFreePackets(p, 3);
+end:
+    return result;
+}
+
+/**
+ * \internal
+ * \brief This function registers unit tests for DetectSeq
+ */
+static void DetectSeqRegisterTests(void)
+{
+    UtRegisterTest("DetectSeqSigTest01", DetectSeqSigTest01);
+    UtRegisterTest("DetectSeqSigTest02", DetectSeqSigTest02);
+}
+#endif /* UNITTESTS */