bytetest: add unittest showing missed detection

Tests recursive and relative negative byte_test matching.

src/detect-engine-hsbd.c

@@ -2641,6 +2641,133 @@ end:
     return result;
 }
 
+/* \test recursive relative byte test */
+static int DetectEngineHttpServerBodyFileDataTest03(void)
+{
+    TcpSession ssn;
+    Packet *p1 = NULL;
+    Packet *p2 = NULL;
+    ThreadVars th_v;
+    DetectEngineCtx *de_ctx = NULL;
+    DetectEngineThreadCtx *det_ctx = NULL;
+    HtpState *http_state = NULL;
+    Flow f;
+    uint8_t http_buf1[] =
+        "GET /index.html HTTP/1.0\r\n"
+        "Host: www.openinfosecfoundation.org\r\n"
+        "User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1.7) Gecko/20091221 Firefox/3.5.7\r\n"
+        "\r\n";
+    uint32_t http_len1 = sizeof(http_buf1) - 1;
+    uint8_t http_buf2[] =
+        "HTTP/1.0 200 ok\r\n"
+        "Content-Type: text/html\r\n"
+        "Content-Length: 33\r\n"
+        "\r\n"
+        "XYZ_klm_1234abcd_XYZ_klm_5678abcd";
+    uint32_t http_len2 = sizeof(http_buf2) - 1;
+    int result = 0;
+
+    memset(&th_v, 0, sizeof(th_v));
+    memset(&f, 0, sizeof(f));
+    memset(&ssn, 0, sizeof(ssn));
+
+    p1 = UTHBuildPacket(NULL, 0, IPPROTO_TCP);
+    p2 = UTHBuildPacket(NULL, 0, IPPROTO_TCP);
+
+    FLOW_INITIALIZE(&f);
+    f.protoctx = (void *)&ssn;
+    f.flags |= FLOW_IPV4;
+
+    p1->flow = &f;
+    p1->flowflags |= FLOW_PKT_TOSERVER;
+    p1->flowflags |= FLOW_PKT_ESTABLISHED;
+    p1->flags |= PKT_HAS_FLOW|PKT_STREAM_EST;
+    p2->flow = &f;
+    p2->flowflags |= FLOW_PKT_TOCLIENT;
+    p2->flowflags |= FLOW_PKT_ESTABLISHED;
+    p2->flags |= PKT_HAS_FLOW|PKT_STREAM_EST;
+    f.alproto = ALPROTO_HTTP;
+
+    StreamTcpInitConfig(TRUE);
+
+    de_ctx = DetectEngineCtxInit();
+    if (de_ctx == NULL)
+        goto end;
+
+    de_ctx->flags |= DE_QUIET;
+
+    if (!(DetectEngineAppendSig(de_ctx, "alert http any any -> any any "
+                               "(msg:\"match on 1st\"; "
+                               "file_data; content:\"XYZ\"; content:\"_klm_\"; distance:0; content:\"abcd\"; distance:4; byte_test:4,=,1234,-8,relative,string;"
+                               "sid:1;)")))
+        goto end;
+    if (!(DetectEngineAppendSig(de_ctx, "alert http any any -> any any "
+                               "(msg:\"match on 2nd\"; "
+                               "file_data; content:\"XYZ\"; content:\"_klm_\"; distance:0; content:\"abcd\"; distance:4; byte_test:4,=,5678,-8,relative,string;"
+                               "sid:2;)")))
+        goto end;
+
+    SigGroupBuild(de_ctx);
+    DetectEngineThreadCtxInit(&th_v, (void *)de_ctx, (void *)&det_ctx);
+
+    int r = AppLayerParse(NULL, &f, ALPROTO_HTTP, STREAM_TOSERVER, http_buf1, http_len1);
+    if (r != 0) {
+        printf("toserver chunk 1 returned %" PRId32 ", expected 0: ", r);
+        result = 0;
+        goto end;
+    }
+
+    http_state = f.alstate;
+    if (http_state == NULL) {
+        printf("no http state: \n");
+        result = 0;
+        goto end;
+    }
+
+    /* do detect */
+    SigMatchSignatures(&th_v, de_ctx, det_ctx, p1);
+
+    if (PacketAlertCheck(p1, 1)) {
+        printf("sid 1 matched but shouldn't have: ");
+        goto end;
+    }
+
+    r = AppLayerParse(NULL, &f, ALPROTO_HTTP, STREAM_TOCLIENT, http_buf2, http_len2);
+    if (r != 0) {
+        printf("toserver chunk 1 returned %" PRId32 ", expected 0: \n", r);
+        result = 0;
+        goto end;
+    }
+
+    /* do detect */
+    SigMatchSignatures(&th_v, de_ctx, det_ctx, p2);
+
+    if (!PacketAlertCheck(p2, 1)) {
+        printf("sid 1 did not match but should have: ");
+        goto end;
+    }
+    if (!PacketAlertCheck(p2, 2)) {
+        printf("sid 2 did not match but should have: ");
+        goto end;
+    }
+
+    result = 1;
+
+end:
+    if (de_ctx != NULL)
+        SigGroupCleanup(de_ctx);
+    if (de_ctx != NULL)
+        SigCleanSignatures(de_ctx);
+    if (de_ctx != NULL)
+        DetectEngineCtxFree(de_ctx);
+
+    StreamTcpFreeConfig(TRUE);
+    FLOW_DESTROY(&f);
+    UTHFreePackets(&p1, 1);
+    UTHFreePackets(&p2, 1);
+    return result;
+}
+
 #endif /* UNITTESTS */
 
 void DetectEngineHttpServerBodyRegisterTests(void)
@@ -2686,6 +2813,8 @@ void DetectEngineHttpServerBodyRegisterTests(void)
                    DetectEngineHttpServerBodyFileDataTest01, 1);
     UtRegisterTest("DetectEngineHttpServerBodyFileDataTest02",
                    DetectEngineHttpServerBodyFileDataTest02, 1);
+    UtRegisterTest("DetectEngineHttpServerBodyFileDataTest03",
+                   DetectEngineHttpServerBodyFileDataTest03, 1);
 #endif /* UNITTESTS */
 
     return;