From: Victor Julien Date: Wed, 19 Jun 2019 10:54:13 +0000 (+0200) Subject: detect: tcp.hdr sticky buffer X-Git-Tag: suricata-5.0.0-rc1~247 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=35be8385eb77f6f292eb3d34f9a997ab714f22af;p=thirdparty%2Fsuricata.git detect: tcp.hdr sticky buffer Sticky buffer to inspect the TCP header. --- diff --git a/src/Makefile.am b/src/Makefile.am index f165b09665..4376047498 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -248,6 +248,7 @@ detect-tag.c detect-tag.h \ detect-target.c detect-target.h \ detect-template.c detect-template.h \ detect-template2.c detect-template2.h \ +detect-tcphdr.c detect-tcphdr.h \ detect-tcpmss.c detect-tcpmss.h \ detect-ftpdata.c detect-ftpdata.h \ detect-template-rust-buffer.c detect-template-rust-buffer.h \ diff --git a/src/detect-engine-mpm.c b/src/detect-engine-mpm.c index 7bbb1b8f9d..9ecf78f7db 100644 --- a/src/detect-engine-mpm.c +++ b/src/detect-engine-mpm.c @@ -42,6 +42,7 @@ #include "util-memcpy.h" #include "conf.h" #include "detect-fast-pattern.h" +#include "detect-tcphdr.h" #include "flow.h" #include "flow-var.h" @@ -1384,6 +1385,11 @@ int PatternMatchPrepareGroup(DetectEngineCtx *de_ctx, SigGroupHead *sh) } SetRawReassemblyFlag(de_ctx, sh); + + mpm_store = MpmStorePrepareBuffer(de_ctx, sh, MPMB_L4HDR_TS); + if (mpm_store != NULL) { + PrefilterTcpHeaderRegister(de_ctx, sh, mpm_store->mpm_ctx); + } } if (SGH_DIRECTION_TC(sh)) { mpm_store = MpmStorePrepareBuffer(de_ctx, sh, MPMB_TCP_PKT_TC); @@ -1397,6 +1403,11 @@ int PatternMatchPrepareGroup(DetectEngineCtx *de_ctx, SigGroupHead *sh) } SetRawReassemblyFlag(de_ctx, sh); + + mpm_store = MpmStorePrepareBuffer(de_ctx, sh, MPMB_L4HDR_TC); + if (mpm_store != NULL) { + PrefilterTcpHeaderRegister(de_ctx, sh, mpm_store->mpm_ctx); + } } } else if (SGH_PROTO(sh, IPPROTO_UDP)) { if (SGH_DIRECTION_TS(sh)) { diff --git a/src/detect-engine-register.c b/src/detect-engine-register.c index 3d14d53da3..7e74e025b1 100644 --- a/src/detect-engine-register.c +++ b/src/detect-engine-register.c @@ -167,6 +167,7 @@ #include "detect-app-layer-protocol.h" #include "detect-template.h" #include "detect-template2.h" +#include "detect-tcphdr.h" #include "detect-tcpmss.h" #include "detect-krb5-cname.h" #include "detect-krb5-errcode.h" @@ -524,6 +525,7 @@ void SigTableSetup(void) DetectBase64DataRegister(); DetectTemplateRegister(); DetectTemplate2Register(); + DetectTcphdrRegister(); DetectTcpmssRegister(); DetectKrb5CNameRegister(); DetectKrb5ErrCodeRegister(); diff --git a/src/detect-engine-register.h b/src/detect-engine-register.h index ef8d9f821e..76ee057933 100644 --- a/src/detect-engine-register.h +++ b/src/detect-engine-register.h @@ -225,6 +225,7 @@ enum { DETECT_TEMPLATE, DETECT_TEMPLATE2, + DETECT_TCPHDR, DETECT_TCPMSS, DETECT_FTPDATA, DETECT_TARGET, diff --git a/src/detect-engine.c b/src/detect-engine.c index 3b53f03c00..6172341c9f 100644 --- a/src/detect-engine.c +++ b/src/detect-engine.c @@ -54,6 +54,7 @@ #include "detect-byte-extract.h" #include "detect-content.h" #include "detect-uricontent.h" +#include "detect-tcphdr.h" #include "detect-engine-threshold.h" #include "detect-engine-content-inspection.h" @@ -1248,6 +1249,15 @@ int DetectEnginePktInspectionSetup(Signature *s) SCLogDebug("sid %u: DetectEngineInspectRulePayloadMatches appended", s->id); } + if (s->sm_arrays[DETECT_SM_LIST_L4HDR] && + (s->proto.proto[IPPROTO_TCP / 8] & (1 << (IPPROTO_TCP % 8)))) + { + if (DetectEnginePktInspectionAppend(s, DetectEngineInspectRuleTcpHeaderMatches, + s->sm_arrays[DETECT_SM_LIST_L4HDR]) < 0) + return -1; + SCLogDebug("sid %u: DetectEngineInspectRuleTcpHeaderMatches appended", s->id); + } + if (s->sm_arrays[DETECT_SM_LIST_MATCH]) { if (DetectEnginePktInspectionAppend(s, DetectEngineInspectRulePacketMatches, s->sm_arrays[DETECT_SM_LIST_MATCH]) < 0) diff --git a/src/detect-tcphdr.c b/src/detect-tcphdr.c new file mode 100644 index 0000000000..bec48980cc --- /dev/null +++ b/src/detect-tcphdr.c @@ -0,0 +1,168 @@ +/* Copyright (C) 2007-2019 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. + */ + +/** + * \file + * + * \author Victor Julien + * + */ + +#include "suricata-common.h" + +#include "detect.h" +#include "detect-parse.h" +#include "detect-engine.h" +#include "detect-engine-prefilter.h" +#include "detect-engine-content-inspection.h" +#include "detect-fast-pattern.h" +#include "detect-tcphdr.h" + +/* prototypes */ +static int DetectTcphdrSetup (DetectEngineCtx *, Signature *, const char *); +#ifdef UNITTESTS +void DetectTcphdrRegisterTests (void); +#endif + +/** + * \brief Registration function for tcphdr: keyword + */ + +void DetectTcphdrRegister(void) +{ + sigmatch_table[DETECT_TCPHDR].name = "tcp.hdr"; + sigmatch_table[DETECT_TCPHDR].desc = "sticky buffer to match on the TCP header"; + sigmatch_table[DETECT_TCPHDR].url = DOC_URL DOC_VERSION "/rules/header-keywords.html#tcphdr"; + sigmatch_table[DETECT_TCPHDR].Setup = DetectTcphdrSetup; + sigmatch_table[DETECT_TCPHDR].flags |= SIGMATCH_NOOPT | SIGMATCH_INFO_STICKY_BUFFER; +#ifdef UNITTESTS + sigmatch_table[DETECT_TCPHDR].RegisterTests = DetectTcphdrRegisterTests; +#endif + SupportFastPatternForSigMatchList(DETECT_SM_LIST_L4HDR, 2); + return; +} + +/** + * \brief this function is used to atcphdrd the parsed tcphdr data into the current signature + * + * \param de_ctx pointer to the Detection Engine Context + * \param s pointer to the Current Signature + * \param tcphdrstr pointer to the user provided tcphdr options + * + * \retval 0 on Success + * \retval -1 on Failure + */ +static int DetectTcphdrSetup (DetectEngineCtx *de_ctx, Signature *s, const char *tcphdrstr) +{ + if (!(DetectProtoContainsProto(&s->proto, IPPROTO_TCP))) + return -1; + + s->flags |= SIG_FLAG_REQUIRE_PACKET; + + if (DetectBufferSetActiveList(s, DETECT_SM_LIST_L4HDR) < 0) + return -1; + + return 0; +} + +static void PrefilterTcpHeader(DetectEngineThreadCtx *det_ctx, + Packet *p, const void *pectx) +{ + SCEnter(); + + uint32_t hlen = TCP_GET_HLEN(p); + if (((uint8_t *)p->tcph + (ptrdiff_t)hlen) > + ((uint8_t *)GET_PKT_DATA(p) + (ptrdiff_t)GET_PKT_LEN(p))) + { + SCLogDebug("data out of range: %p > %p", + ((uint8_t *)p->tcph + (ptrdiff_t)hlen), + ((uint8_t *)GET_PKT_DATA(p) + (ptrdiff_t)GET_PKT_LEN(p))); + SCReturn; + } + + const MpmCtx *mpm_ctx = (MpmCtx *)pectx; + if (hlen < mpm_ctx->minlen) + SCReturn; + + (void)mpm_table[mpm_ctx->mpm_type].Search(mpm_ctx, + &det_ctx->mtc, &det_ctx->pmq, + (uint8_t *)p->tcph, hlen); +} + +int PrefilterTcpHeaderRegister(DetectEngineCtx *de_ctx, + SigGroupHead *sgh, MpmCtx *mpm_ctx) +{ + return PrefilterAppendEngine(de_ctx, sgh, + PrefilterTcpHeader, mpm_ctx, NULL, "tcp.hdr"); +} + +/** + * \brief Do the content inspection & validation for a signature + * + * \param det_ctx Detection engine thread context + * \param s Signature to inspect + * \param p Packet + * + * \retval false no match + * \retval true match + */ +bool DetectEngineInspectRuleTcpHeaderMatches( + ThreadVars *tv, DetectEngineThreadCtx *det_ctx, + const Signature *s, const SigMatchData *sm_data, + Flow *f, Packet *p, + uint8_t *alert_flags) +{ + SCEnter(); + + BUG_ON(sm_data == NULL); + BUG_ON(sm_data != s->sm_arrays[DETECT_SM_LIST_L4HDR]); + + if (!(PKT_IS_TCP(p))) { + SCReturnInt(false); + } + uint32_t hlen = TCP_GET_HLEN(p); + if (((uint8_t *)p->tcph + (ptrdiff_t)hlen) > + ((uint8_t *)GET_PKT_DATA(p) + (ptrdiff_t)GET_PKT_LEN(p))) + { + SCLogDebug("data out of range: %p > %p", + ((uint8_t *)p->tcph + (ptrdiff_t)hlen), + ((uint8_t *)GET_PKT_DATA(p) + (ptrdiff_t)GET_PKT_LEN(p))); + SCReturnInt(false); + } + +#ifdef DEBUG + det_ctx->payload_persig_cnt++; + det_ctx->payload_persig_size += hlen; +#endif + det_ctx->buffer_offset = 0; + det_ctx->discontinue_matching = 0; + det_ctx->inspection_recursion_counter = 0; + det_ctx->replist = NULL; + + int r = DetectEngineContentInspection(det_ctx->de_ctx, det_ctx, + s, sm_data, + p, NULL, (uint8_t *)p->tcph, hlen, 0, + DETECT_CI_FLAGS_SINGLE, DETECT_ENGINE_CONTENT_INSPECTION_MODE_HEADER); + if (r == 1) { + SCReturnInt(true); + } + SCReturnInt(false); +} + +#ifdef UNITTESTS +#include "tests/detect-tcphdr.c" +#endif diff --git a/src/detect-tcphdr.h b/src/detect-tcphdr.h new file mode 100644 index 0000000000..0bd1f94174 --- /dev/null +++ b/src/detect-tcphdr.h @@ -0,0 +1,36 @@ +/* Copyright (C) 2007-2019 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. + */ + +/** + * \file + * + * \author Victor Julien + */ + +#ifndef _DETECT_TCPHDR_H +#define _DETECT_TCPHDR_H + +int PrefilterTcpHeaderRegister(DetectEngineCtx *de_ctx, + SigGroupHead *sgh, MpmCtx *mpm_ctx); +bool DetectEngineInspectRuleTcpHeaderMatches( + ThreadVars *tv, DetectEngineThreadCtx *det_ctx, + const Signature *s, const SigMatchData *sm_data, + Flow *f, Packet *p, + uint8_t *alert_flags); +void DetectTcphdrRegister(void); + +#endif /* _DETECT_TCPHDR_H */ diff --git a/src/tests/detect-tcphdr.c b/src/tests/detect-tcphdr.c new file mode 100644 index 0000000000..6faa0d716f --- /dev/null +++ b/src/tests/detect-tcphdr.c @@ -0,0 +1,47 @@ +/* Copyright (C) 2007-2018 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. + */ + +#include "../suricata-common.h" + +#include "../detect.h" +#include "../detect-parse.h" +#include "../detect-engine-prefilter-common.h" + +#include "../detect-tcphdr.h" + +#include "../util-unittest.h" + +static int DetectTcphdrParseTest01 (void) +{ + DetectEngineCtx *de_ctx = DetectEngineCtxInit(); + FAIL_IF_NULL(de_ctx); + + Signature *sig = DetectEngineAppendSig(de_ctx, + "alert tcp any any -> any any (tcp.hdr; content:\"A\"; sid:1; rev:1;)"); + FAIL_IF_NULL(sig); + + DetectEngineCtxFree(de_ctx); + PASS; +} + +/** + * \brief this function registers unit tests for DetectTcphdr + */ +void DetectTcphdrRegisterTests(void) +{ + UtRegisterTest("DetectTcphdrParseTest01", DetectTcphdrParseTest01); +}