From 28a6c1d9f8c47695081ec850e72a22417aedde4c Mon Sep 17 00:00:00 2001 From: Victor Julien Date: Wed, 24 Apr 2013 14:02:53 +0200 Subject: [PATCH] DNS: add test for app layer event match --- src/detect-dns-query.c | 187 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 187 insertions(+) diff --git a/src/detect-dns-query.c b/src/detect-dns-query.c index 49aebfa9fa..5570239ff1 100644 --- a/src/detect-dns-query.c +++ b/src/detect-dns-query.c @@ -869,6 +869,192 @@ end: return result; } +/** \test multi tx google.(com|net) query matching + + * app layer event */ +static int DetectDnsQueryTest07(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, recusion 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, }; + int result = 0; + Flow f; + DNSState *dns_state = NULL; + Packet *p1 = NULL, *p2 = NULL, *p3 = NULL; + Signature *s = NULL; + ThreadVars tv; + DetectEngineThreadCtx *det_ctx = NULL; + + memset(&tv, 0, sizeof(ThreadVars)); + memset(&f, 0, sizeof(Flow)); + + p1 = UTHBuildPacket(buf1, sizeof(buf1), IPPROTO_UDP); + p2 = UTHBuildPacket(buf2, sizeof(buf2), IPPROTO_UDP); + p3 = UTHBuildPacket(buf3, sizeof(buf3), IPPROTO_UDP); + + FLOW_INITIALIZE(&f); + f.flags |= FLOW_IPV4; + f.proto = IPPROTO_UDP; + f.alproto = ALPROTO_DNS_UDP; + + 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(); + if (de_ctx == NULL) { + goto end; + } + de_ctx->mpm_matcher = MPM_AC; + de_ctx->flags |= DE_QUIET; + + s = DetectEngineAppendSig(de_ctx, "alert dns any any -> any any " + "(msg:\"Test dns_query option\"; " + "content:\"google.com\"; nocase; dns_query; sid:1;)"); + if (s == NULL) { + goto end; + } + s = DetectEngineAppendSig(de_ctx, "alert dns any any -> any any " + "(msg:\"Test dns_query option\"; " + "content:\"google.net\"; nocase; dns_query; sid:2;)"); + if (s == NULL) { + goto end; + } + s = DetectEngineAppendSig(de_ctx, "alert dns any any -> any any " + "(msg:\"Test Z flag event\"; " + "app-layer-event:dns.z_flag_set; sid:3;)"); + if (s == NULL) { + goto end; + } + + SigGroupBuild(de_ctx); + DetectEngineThreadCtxInit(&tv, (void *)de_ctx, (void *)&det_ctx); + + int r = AppLayerParse(NULL, &f, ALPROTO_DNS_UDP, STREAM_TOSERVER, buf1, sizeof(buf1)); + if (r != 0) { + printf("toserver chunk 1 returned %" PRId32 ", expected 0: ", r); + goto end; + } + + dns_state = f.alstate; + if (dns_state == NULL) { + printf("no dns state: "); + goto end; + } + + /* do detect */ + SigMatchSignatures(&tv, de_ctx, det_ctx, p1); + + if (!(PacketAlertCheck(p1, 1))) { + printf("(p1) sig 1 didn't alert, but it should have: "); + goto end; + } + if (PacketAlertCheck(p1, 2)) { + printf("(p1) sig 2 did alert, but it should not have: "); + goto end; + } + + r = AppLayerParse(NULL, &f, ALPROTO_DNS_UDP, STREAM_TOCLIENT, buf2, sizeof(buf2)); + if (r != -1) { + printf("toserver client 1 returned %" PRId32 ", expected 0: ", r); + goto end; + } + + /* do detect */ + SigMatchSignatures(&tv, de_ctx, det_ctx, p2); + + if (PacketAlertCheck(p2, 1)) { + printf("(p2) sig 1 alerted, but it should not have: "); + goto end; + } + if (PacketAlertCheck(p2, 2)) { + printf("(p2) sig 2 alerted, but it should not have: "); + goto end; + } + if (!(PacketAlertCheck(p2, 3))) { + printf("(p2) sig 3 didn't alert, but it should have: "); + goto end; + } + + r = AppLayerParse(NULL, &f, ALPROTO_DNS_UDP, STREAM_TOSERVER, buf3, sizeof(buf3)); + if (r != 0) { + printf("toserver chunk 3 returned %" PRId32 ", expected 0: ", r); + goto end; + } + + /* do detect */ + SigMatchSignatures(&tv, de_ctx, det_ctx, p3); + + if (PacketAlertCheck(p3, 1)) { + printf("(p3) sig 1 alerted, but it should not have: "); + goto end; + } + if (!(PacketAlertCheck(p3, 2))) { + printf("(p3) sig 2 didn't alert, but it should have: "); + goto end; + } + /* VJ currently we when we reset de_state we reset AMATCH too, + * this resets app-layer-event matching as well. However, we + * are not clearing/reseting app events, so we match over and + * over again */ +#if 0 + if (PacketAlertCheck(p3, 3)) { + printf("(p3) sig 3 did alerted, but it should not have: "); + goto end; + } +#endif + result = 1; + +end: + 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); + return result; +} + #endif static void DetectDnsQueryRegisterTests(void) { @@ -879,5 +1065,6 @@ static void DetectDnsQueryRegisterTests(void) { UtRegisterTest("DetectDnsQueryTest04 -- tcp splicing", DetectDnsQueryTest04, 1); UtRegisterTest("DetectDnsQueryTest05 -- tcp splicing/multi tx", DetectDnsQueryTest05, 1); UtRegisterTest("DetectDnsQueryTest06 -- pcre", DetectDnsQueryTest06, 1); + UtRegisterTest("DetectDnsQueryTest07 -- app layer event", DetectDnsQueryTest07, 1); #endif }