From 486054595a067b068847c4e91d0457dcfdcd75b4 Mon Sep 17 00:00:00 2001 From: Victor Julien Date: Wed, 19 Sep 2018 18:48:53 +0200 Subject: [PATCH] detect/template2: template with prefilter (copy of ttl) --- src/Makefile.am | 1 + src/detect-engine-register.c | 2 + src/detect-engine-register.h | 1 + src/detect-template2.c | 383 +++++++++++++++++++++++++++++++++++ src/detect-template2.h | 42 ++++ src/tests/detect-template2.c | 155 ++++++++++++++ 6 files changed, 584 insertions(+) create mode 100644 src/detect-template2.c create mode 100644 src/detect-template2.h create mode 100644 src/tests/detect-template2.c diff --git a/src/Makefile.am b/src/Makefile.am index d14bce84a2..69ad4d810b 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -255,6 +255,7 @@ detect-stream_size.c detect-stream_size.h \ 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-ftpdata.c detect-ftpdata.h \ detect-template-buffer.c detect-template-buffer.h \ detect-threshold.c detect-threshold.h \ diff --git a/src/detect-engine-register.c b/src/detect-engine-register.c index c2b961903a..0fbc376b81 100644 --- a/src/detect-engine-register.c +++ b/src/detect-engine-register.c @@ -178,6 +178,7 @@ #include "detect-geoip.h" #include "detect-app-layer-protocol.h" #include "detect-template.h" +#include "detect-template2.h" #include "detect-krb5-cname.h" #include "detect-krb5-errcode.h" #include "detect-krb5-msgtype.h" @@ -505,6 +506,7 @@ void SigTableSetup(void) DetectBase64DecodeRegister(); DetectBase64DataRegister(); DetectTemplateRegister(); + DetectTemplate2Register(); DetectKrb5CNameRegister(); DetectKrb5ErrCodeRegister(); DetectKrb5MsgTypeRegister(); diff --git a/src/detect-engine-register.h b/src/detect-engine-register.h index ee8d2db9f7..762a01b439 100644 --- a/src/detect-engine-register.h +++ b/src/detect-engine-register.h @@ -203,6 +203,7 @@ enum { DETECT_AL_KRB5_SNAME, DETECT_TEMPLATE, + DETECT_TEMPLATE2, DETECT_FTPDATA, DETECT_TARGET, DETECT_AL_TEMPLATE_BUFFER, diff --git a/src/detect-template2.c b/src/detect-template2.c new file mode 100644 index 0000000000..d45684a3ad --- /dev/null +++ b/src/detect-template2.c @@ -0,0 +1,383 @@ +/* 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. + */ + +/** + * \file + * + * \author XXX + * + */ + +#include "suricata-common.h" + +#include "detect.h" +#include "detect-parse.h" +#include "detect-engine-prefilter-common.h" + +#include "detect-template2.h" + +/** + * \brief Regex for parsing our options + */ +#define PARSE_REGEX "^\\s*([0-9]*)?\\s*([<>=-]+)?\\s*([0-9]+)?\\s*$" + +static pcre *parse_regex; +static pcre_extra *parse_regex_study; + +/* prototypes */ +static int DetectTemplate2Match (ThreadVars *, DetectEngineThreadCtx *, Packet *, + const Signature *, const SigMatchCtx *); +static int DetectTemplate2Setup (DetectEngineCtx *, Signature *, const char *); +void DetectTemplate2Free (void *); +#ifdef UNITTESTS +void DetectTemplate2RegisterTests (void); +#endif +static int PrefilterSetupTemplate2(DetectEngineCtx *de_ctx, SigGroupHead *sgh); +static _Bool PrefilterTemplate2IsPrefilterable(const Signature *s); + +/** + * \brief Registration function for template2: keyword + */ + +void DetectTemplate2Register(void) +{ + sigmatch_table[DETECT_TEMPLATE2].name = "template2"; + sigmatch_table[DETECT_TEMPLATE2].desc = "TODO describe the keyword"; + sigmatch_table[DETECT_TEMPLATE2].url = DOC_URL DOC_VERSION "/rules/header-keywords.html#template2"; + sigmatch_table[DETECT_TEMPLATE2].Match = DetectTemplate2Match; + sigmatch_table[DETECT_TEMPLATE2].Setup = DetectTemplate2Setup; + sigmatch_table[DETECT_TEMPLATE2].Free = DetectTemplate2Free; +#ifdef UNITTESTS + sigmatch_table[DETECT_TEMPLATE2].RegisterTests = DetectTemplate2RegisterTests; +#endif + sigmatch_table[DETECT_TEMPLATE2].SupportsPrefilter = PrefilterTemplate2IsPrefilterable; + sigmatch_table[DETECT_TEMPLATE2].SetupPrefilter = PrefilterSetupTemplate2; + + DetectSetupParseRegexes(PARSE_REGEX, &parse_regex, &parse_regex_study); + return; +} + +static inline int Template2Match(const uint8_t parg, const uint8_t mode, + const uint8_t darg1, const uint8_t darg2) +{ + if (mode == DETECT_TEMPLATE2_EQ && parg == darg1) + return 1; + else if (mode == DETECT_TEMPLATE2_LT && parg < darg1) + return 1; + else if (mode == DETECT_TEMPLATE2_GT && parg > darg1) + return 1; + else if (mode == DETECT_TEMPLATE2_RA && (parg > darg1 && parg < darg2)) + return 1; + + return 0; +} + +/** + * \brief This function is used to match TEMPLATE2 rule option on a packet with those passed via template2: + * + * \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 DetectTemplate2Data + * + * \retval 0 no match + * \retval 1 match + */ +static int DetectTemplate2Match (ThreadVars *t, DetectEngineThreadCtx *det_ctx, Packet *p, + const Signature *s, const SigMatchCtx *ctx) +{ + + if (PKT_IS_PSEUDOPKT(p)) + return 0; + + /* TODO replace this */ + uint8_t ptemplate2; + if (PKT_IS_IPV4(p)) { + ptemplate2 = IPV4_GET_IPTTL(p); + } else if (PKT_IS_IPV6(p)) { + ptemplate2 = IPV6_GET_HLIM(p); + } else { + SCLogDebug("Packet is of not IPv4 or IPv6"); + return 0; + } + + const DetectTemplate2Data *template2d = (const DetectTemplate2Data *)ctx; + return Template2Match(ptemplate2, template2d->mode, template2d->arg1, template2d->arg2); +} + +/** + * \brief This function is used to parse template2 options passed via template2: keyword + * + * \param template2str Pointer to the user provided template2 options + * + * \retval template2d pointer to DetectTemplate2Data on success + * \retval NULL on failure + */ + +static DetectTemplate2Data *DetectTemplate2Parse (const char *template2str) +{ + DetectTemplate2Data *template2d = NULL; + char *arg1 = NULL; + char *arg2 = NULL; + char *arg3 = NULL; +#define MAX_SUBSTRINGS 30 + int ret = 0, res = 0; + int ov[MAX_SUBSTRINGS]; + + ret = pcre_exec(parse_regex, parse_regex_study, template2str, strlen(template2str), 0, 0, ov, MAX_SUBSTRINGS); + if (ret < 2 || ret > 4) { + SCLogError(SC_ERR_PCRE_MATCH, "parse error, ret %" PRId32 "", ret); + goto error; + } + const char *str_ptr; + + res = pcre_get_substring((char *) template2str, ov, MAX_SUBSTRINGS, 1, &str_ptr); + if (res < 0) { + SCLogError(SC_ERR_PCRE_GET_SUBSTRING, "pcre_get_substring failed"); + goto error; + } + arg1 = (char *) str_ptr; + SCLogDebug("Arg1 \"%s\"", arg1); + + if (ret >= 3) { + res = pcre_get_substring((char *) template2str, ov, MAX_SUBSTRINGS, 2, &str_ptr); + if (res < 0) { + SCLogError(SC_ERR_PCRE_GET_SUBSTRING, "pcre_get_substring failed"); + goto error; + } + arg2 = (char *) str_ptr; + SCLogDebug("Arg2 \"%s\"", arg2); + + if (ret >= 4) { + res = pcre_get_substring((char *) template2str, ov, MAX_SUBSTRINGS, 3, &str_ptr); + if (res < 0) { + SCLogError(SC_ERR_PCRE_GET_SUBSTRING, "pcre_get_substring failed"); + goto error; + } + arg3 = (char *) str_ptr; + SCLogDebug("Arg3 \"%s\"", arg3); + } + } + + template2d = SCMalloc(sizeof (DetectTemplate2Data)); + if (unlikely(template2d == NULL)) + goto error; + template2d->arg1 = 0; + template2d->arg2 = 0; + + if (arg2 != NULL) { + /*set the values*/ + switch(arg2[0]) { + case '<': + if (arg3 == NULL) + goto error; + + template2d->mode = DETECT_TEMPLATE2_LT; + template2d->arg1 = (uint8_t) atoi(arg3); + + SCLogDebug("template2 is %"PRIu8"",template2d->arg1); + if (strlen(arg1) > 0) + goto error; + + break; + case '>': + if (arg3 == NULL) + goto error; + + template2d->mode = DETECT_TEMPLATE2_GT; + template2d->arg1 = (uint8_t) atoi(arg3); + + SCLogDebug("template2 is %"PRIu8"",template2d->arg1); + if (strlen(arg1) > 0) + goto error; + + break; + case '-': + if (arg1 == NULL || strlen(arg1)== 0) + goto error; + if (arg3 == NULL || strlen(arg3)== 0) + goto error; + + template2d->mode = DETECT_TEMPLATE2_RA; + template2d->arg1 = (uint8_t) atoi(arg1); + + template2d->arg2 = (uint8_t) atoi(arg3); + SCLogDebug("template2 is %"PRIu8" to %"PRIu8"",template2d->arg1, template2d->arg2); + if (template2d->arg1 >= template2d->arg2) { + SCLogError(SC_ERR_INVALID_SIGNATURE, "Invalid template2 range. "); + goto error; + } + break; + default: + template2d->mode = DETECT_TEMPLATE2_EQ; + + if ((arg2 != NULL && strlen(arg2) > 0) || + (arg3 != NULL && strlen(arg3) > 0) || + (arg1 == NULL ||strlen(arg1) == 0)) + goto error; + + template2d->arg1 = (uint8_t) atoi(arg1); + break; + } + } else { + template2d->mode = DETECT_TEMPLATE2_EQ; + + if ((arg3 != NULL && strlen(arg3) > 0) || + (arg1 == NULL ||strlen(arg1) == 0)) + goto error; + + template2d->arg1 = (uint8_t) atoi(arg1); + } + + SCFree(arg1); + SCFree(arg2); + SCFree(arg3); + return template2d; + +error: + if (template2d) + SCFree(template2d); + if (arg1) + SCFree(arg1); + if (arg2) + SCFree(arg2); + if (arg3) + SCFree(arg3); + return NULL; +} + +/** + * \brief this function is used to atemplate2d the parsed template2 data into the current signature + * + * \param de_ctx pointer to the Detection Engine Context + * \param s pointer to the Current Signature + * \param template2str pointer to the user provided template2 options + * + * \retval 0 on Success + * \retval -1 on Failure + */ +static int DetectTemplate2Setup (DetectEngineCtx *de_ctx, Signature *s, const char *template2str) +{ + DetectTemplate2Data *template2d = DetectTemplate2Parse(template2str); + if (template2d == NULL) + return -1; + + SigMatch *sm = SigMatchAlloc(); + if (sm == NULL) { + DetectTemplate2Free(template2d); + return -1; + } + + sm->type = DETECT_TEMPLATE2; + sm->ctx = (SigMatchCtx *)template2d; + + SigMatchAppendSMToList(s, sm, DETECT_SM_LIST_MATCH); + s->flags |= SIG_FLAG_REQUIRE_PACKET; + + return 0; +} + +/** + * \brief this function will free memory associated with DetectTemplate2Data + * + * \param ptr pointer to DetectTemplate2Data + */ +void DetectTemplate2Free(void *ptr) +{ + DetectTemplate2Data *template2d = (DetectTemplate2Data *)ptr; + SCFree(template2d); +} + +/* prefilter code */ + +static void +PrefilterPacketTemplate2Match(DetectEngineThreadCtx *det_ctx, Packet *p, const void *pectx) +{ + if (PKT_IS_PSEUDOPKT(p)) { + SCReturn; + } + + uint8_t ptemplate2; +/* TODO update */ + if (PKT_IS_IPV4(p)) { + ptemplate2 = IPV4_GET_IPTTL(p); + } else if (PKT_IS_IPV6(p)) { + ptemplate2 = IPV6_GET_HLIM(p); + } else { + SCLogDebug("Packet is of not IPv4 or IPv6"); + return; + } + + /* during setup Suricata will automatically see if there is another + * check that can be added: alproto, sport or dport */ + const PrefilterPacketHeaderCtx *ctx = pectx; + if (PrefilterPacketHeaderExtraMatch(ctx, p) == FALSE) + return; + + /* if we match, add all the sigs that use this prefilter. This means + * that these will be inspected further */ + if (Template2Match(ptemplate2, ctx->v1.u8[0], ctx->v1.u8[1], ctx->v1.u8[2])) + { + SCLogDebug("packet matches template2/hl %u", ptemplate2); + PrefilterAddSids(&det_ctx->pmq, ctx->sigs_array, ctx->sigs_cnt); + } +} + +static void +PrefilterPacketTemplate2Set(PrefilterPacketHeaderValue *v, void *smctx) +{ + const DetectTemplate2Data *a = smctx; + v->u8[0] = a->mode; + v->u8[1] = a->arg1; + v->u8[2] = a->arg2; +} + +static _Bool +PrefilterPacketTemplate2Compare(PrefilterPacketHeaderValue v, void *smctx) +{ + const DetectTemplate2Data *a = smctx; + if (v.u8[0] == a->mode && + v.u8[1] == a->arg1 && + v.u8[2] == a->arg2) + return TRUE; + return FALSE; +} + +static int PrefilterSetupTemplate2(DetectEngineCtx *de_ctx, SigGroupHead *sgh) +{ + return PrefilterSetupPacketHeader(de_ctx, sgh, DETECT_TEMPLATE2, + PrefilterPacketTemplate2Set, + PrefilterPacketTemplate2Compare, + PrefilterPacketTemplate2Match); +} + +static _Bool PrefilterTemplate2IsPrefilterable(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_TEMPLATE2: + return TRUE; + } + } + return FALSE; +} + +#ifdef UNITTESTS +#include "tests/detect-template2.c" +#endif + diff --git a/src/detect-template2.h b/src/detect-template2.h new file mode 100644 index 0000000000..e4f8d20bdb --- /dev/null +++ b/src/detect-template2.h @@ -0,0 +1,42 @@ +/* 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. + */ + +/** + * \file + * + * \author XXX + */ + +#ifndef _DETECT_TEMPLATE2_H +#define _DETECT_TEMPLATE2_H + +#define DETECT_TEMPLATE2_LT 0 /**< "less than" operator */ +#define DETECT_TEMPLATE2_EQ 1 /**< "equals" operator (default) */ +#define DETECT_TEMPLATE2_GT 2 /**< "greater than" operator */ +#define DETECT_TEMPLATE2_RA 3 /**< "range" operator */ + +typedef struct DetectTemplate2Data_ { + uint8_t arg1; /**< first arg value in the signature*/ + uint8_t arg2; /**< second arg value in the signature, in case of range + operator*/ + uint8_t mode; /**< operator used in the signature */ +} DetectTemplate2Data; + +void DetectTemplate2Register(void); + +#endif /* _DETECT_TEMPLATE2_H */ + diff --git a/src/tests/detect-template2.c b/src/tests/detect-template2.c new file mode 100644 index 0000000000..78c3712260 --- /dev/null +++ b/src/tests/detect-template2.c @@ -0,0 +1,155 @@ +/* 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-template2.h" + +#include "../util-unittest.h" + +/** + * \test DetectTemplate2ParseTest01 is a test for setting up an valid template2 value. + */ + +static int DetectTemplate2ParseTest01 (void) +{ + DetectTemplate2Data *template2d = DetectTemplate2Parse("10"); + + FAIL_IF_NULL(template2d); + FAIL_IF_NOT(template2d->arg1 == 10); + FAIL_IF_NOT(template2d->mode == DETECT_TEMPLATE2_EQ); + + DetectTemplate2Free(template2d); + + PASS; +} + +/** + * \test DetectTemplate2ParseTest02 is a test for setting up an valid template2 value with + * "<" operator. + */ + +static int DetectTemplate2ParseTest02 (void) +{ + DetectTemplate2Data *template2d = DetectTemplate2Parse("<10"); + + FAIL_IF_NULL(template2d); + FAIL_IF_NOT(template2d->arg1 == 10); + FAIL_IF_NOT(template2d->mode == DETECT_TEMPLATE2_LT); + + DetectTemplate2Free(template2d); + + PASS; +} + +/** + * \test DetectTemplate2ParseTest03 is a test for setting up an valid template2 values with + * "-" operator. + */ + +static int DetectTemplate2ParseTest03 (void) +{ + DetectTemplate2Data *template2d = DetectTemplate2Parse("1-2"); + + FAIL_IF_NULL(template2d); + FAIL_IF_NOT(template2d->arg1 == 1); + FAIL_IF_NOT(template2d->mode == DETECT_TEMPLATE2_RA); + + DetectTemplate2Free(template2d); + + PASS; +} + +/** + * \test DetectTemplate2ParseTest04 is a test for setting up an valid template2 value with + * ">" operator and include spaces arround the given values. + */ + +static int DetectTemplate2ParseTest04 (void) +{ + DetectTemplate2Data *template2d = DetectTemplate2Parse(" > 10 "); + + FAIL_IF_NULL(template2d); + FAIL_IF_NOT(template2d->arg1 == 10); + FAIL_IF_NOT(template2d->mode == DETECT_TEMPLATE2_GT); + + DetectTemplate2Free(template2d); + + PASS; +} + +/** + * \test DetectTemplate2ParseTest05 is a test for setting up an valid template2 values with + * "-" operator and include spaces arround the given values. + */ + +static int DetectTemplate2ParseTest05 (void) +{ + DetectTemplate2Data *template2d = DetectTemplate2Parse(" 1 - 2 "); + + FAIL_IF_NULL(template2d); + FAIL_IF_NOT(template2d->arg1 == 1); + FAIL_IF_NOT(template2d->arg2 == 2); + FAIL_IF_NOT(template2d->mode == DETECT_TEMPLATE2_RA); + + DetectTemplate2Free(template2d); + + PASS; +} + +/** + * \test DetectTemplate2ParseTest06 is a test for setting up an valid template2 values with + * invalid "=" operator and include spaces arround the given values. + */ + +static int DetectTemplate2ParseTest06 (void) +{ + DetectTemplate2Data *template2d = DetectTemplate2Parse(" 1 = 2 "); + FAIL_IF_NOT_NULL(template2d); + PASS; +} + +/** + * \test DetectTemplate2ParseTest07 is a test for setting up an valid template2 values with + * invalid "<>" operator and include spaces arround the given values. + */ + +static int DetectTemplate2ParseTest07 (void) +{ + DetectTemplate2Data *template2d = DetectTemplate2Parse(" 1<>2 "); + FAIL_IF_NOT_NULL(template2d); + PASS; +} + +/** + * \brief this function registers unit tests for DetectTemplate2 + */ +void DetectTemplate2RegisterTests(void) +{ + UtRegisterTest("DetectTemplate2ParseTest01", DetectTemplate2ParseTest01); + UtRegisterTest("DetectTemplate2ParseTest02", DetectTemplate2ParseTest02); + UtRegisterTest("DetectTemplate2ParseTest03", DetectTemplate2ParseTest03); + UtRegisterTest("DetectTemplate2ParseTest04", DetectTemplate2ParseTest04); + UtRegisterTest("DetectTemplate2ParseTest05", DetectTemplate2ParseTest05); + UtRegisterTest("DetectTemplate2ParseTest06", DetectTemplate2ParseTest06); + UtRegisterTest("DetectTemplate2ParseTest07", DetectTemplate2ParseTest07); +} +