From 180885259717ec2d7ec2f99c2c6c43f25bef8337 Mon Sep 17 00:00:00 2001 From: Victor Julien Date: Fri, 30 Nov 2012 16:57:53 +0100 Subject: [PATCH] detect plugin: add helloworld example --- src/Makefile.am | 1 + src/detect-helloworld.c | 294 +++++++++++++++++++++++++++++++++++++++++++++++ src/detect-helloworld.h | 35 ++++++ src/detect.c | 2 + src/detect.h | 2 + 5 files changed, 334 insertions(+) create mode 100644 src/detect-helloworld.c create mode 100644 src/detect-helloworld.h diff --git a/src/Makefile.am b/src/Makefile.am index 0910e06..38a82e1 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -120,6 +120,7 @@ detect-fragbits.c detect-fragbits.h \ detect-fragoffset.c detect-fragoffset.h \ detect-ftpbounce.c detect-ftpbounce.h \ detect-gid.c detect-gid.h \ +detect-helloworld.c detect-helloworld.h \ detect-http-client-body.c detect-http-client-body.h \ detect-http-cookie.c detect-http-cookie.h \ detect-http-header.c detect-http-header.h \ diff --git a/src/detect-helloworld.c b/src/detect-helloworld.c new file mode 100644 index 0000000..5336f2d --- /dev/null +++ b/src/detect-helloworld.c @@ -0,0 +1,294 @@ +/* Copyright (C) 2012 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 Yourname + * + * Short description of the purpose of this keyword + */ + +#include "suricata-common.h" +#include "util-unittest.h" + +#include "detect-parse.h" +#include "detect-engine.h" + +#include "detect-helloworld.h" + +/** + * \brief Regex for parsing our keyword 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 DetectHelloWorldMatch (ThreadVars *, DetectEngineThreadCtx *, + Packet *, Signature *, SigMatch *); +static int DetectHelloWorldSetup (DetectEngineCtx *, Signature *, char *); +static void DetectHelloWorldFree (void *); +static void DetectHelloWorldRegisterTests (void); + +/** + * \brief Registration function for helloworld: keyword + */ +void DetectHelloWorldRegister(void) { + sigmatch_table[DETECT_HELLOWORLD].name = "helloworld"; + sigmatch_table[DETECT_HELLOWORLD].desc = ""; + sigmatch_table[DETECT_HELLOWORLD].url = ""; + sigmatch_table[DETECT_HELLOWORLD].Match = DetectHelloWorldMatch; + sigmatch_table[DETECT_HELLOWORLD].Setup = DetectHelloWorldSetup; + sigmatch_table[DETECT_HELLOWORLD].Free = DetectHelloWorldFree; + sigmatch_table[DETECT_HELLOWORLD].RegisterTests = DetectHelloWorldRegisterTests; + + const char *eb; + int eo; + int opts = 0; + + parse_regex = pcre_compile(PARSE_REGEX, opts, &eb, &eo, NULL); + if (parse_regex == NULL) { + SCLogError(SC_ERR_PCRE_COMPILE, "pcre compile of \"%s\" failed at offset %" PRId32 ": %s", PARSE_REGEX, eo, eb); + goto error; + } + + parse_regex_study = pcre_study(parse_regex, 0, &eb); + if (eb != NULL) { + SCLogError(SC_ERR_PCRE_STUDY, "pcre study failed: %s", eb); + goto error; + } + return; + +error: + if (parse_regex != NULL) + SCFree(parse_regex); + if (parse_regex_study != NULL) + SCFree(parse_regex_study); + return; +} + +/** + * \brief This function is used to match HELLOWORLD rule option on a packet + * + * \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 with context that we will cast into DetectHelloWorldData + * + * \retval 0 no match + * \retval 1 match + */ +int DetectHelloWorldMatch (ThreadVars *t, DetectEngineThreadCtx *det_ctx, Packet *p, Signature *s, SigMatch *m) +{ + int ret = 0; + DetectHelloWorldData *helloworldd = (DetectHelloWorldData *) m->ctx; +#if 0 + if (PKT_IS_PSEUDOPKT(p)) { + /* fake pkt */ + } + + if (PKT_IS_IPV4(p)) { + /* ipv4 pkt */ + } else if (PKT_IS_IPV6(p)) { + /* ipv6 pkt */ + } else { + SCLogDebug("pcket is of not IPv4 or IPv6"); + return ret; + } +#endif + /* packet payload access */ + if (p->payload != NULL && p->payload_len > 0) { + if (helloworldd->helloworld1 == p->payload[0] && + helloworldd->helloworld2 == p->payload[p->payload_len - 1]) + { + ret = 1; + } + } + + return ret; +} + +/** + * \brief This function is used to parse helloworld options passed via helloworld: keyword + * + * \param helloworldstr Pointer to the user provided helloworld options + * + * \retval helloworldd pointer to DetectHelloWorldData on success + * \retval NULL on failure + */ + +DetectHelloWorldData *DetectHelloWorldParse (char *helloworldstr) +{ + DetectHelloWorldData *helloworldd = NULL; + char *arg1 = NULL; + char *arg2 = NULL; +#define MAX_SUBSTRINGS 30 + int ret = 0, res = 0; + int ov[MAX_SUBSTRINGS]; + + ret = pcre_exec(parse_regex, parse_regex_study, helloworldstr, strlen(helloworldstr), 0, 0, ov, MAX_SUBSTRINGS); + if (ret != 3) { + SCLogError(SC_ERR_PCRE_MATCH, "parse error, ret %" PRId32 "", ret); + goto error; + } + const char *str_ptr; + + res = pcre_get_substring((char *) helloworldstr, 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 *) helloworldstr, 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); + + } + + helloworldd = SCMalloc(sizeof (DetectHelloWorldData)); + if (unlikely(helloworldd == NULL)) + goto error; + helloworldd->helloworld1 = (uint8_t)atoi(arg1); + helloworldd->helloworld2 = (uint8_t)atoi(arg2); + + SCFree(arg1); + SCFree(arg2); + return helloworldd; + +error: + if (helloworldd) + SCFree(helloworldd); + if (arg1) + SCFree(arg1); + if (arg2) + SCFree(arg2); + return NULL; +} + +/** + * \brief this function is used to ahelloworldd the parsed helloworld data into the current signature + * + * \param de_ctx pointer to the Detection Engine Context + * \param s pointer to the Current Signature + * \param helloworldstr pointer to the user provided helloworld options + * + * \retval 0 on Success + * \retval -1 on Failure + */ +static int DetectHelloWorldSetup (DetectEngineCtx *de_ctx, Signature *s, char *helloworldstr) +{ + DetectHelloWorldData *helloworldd = NULL; + SigMatch *sm = NULL; + + helloworldd = DetectHelloWorldParse(helloworldstr); + if (helloworldd == NULL) + goto error; + + sm = SigMatchAlloc(); + if (sm == NULL) + goto error; + + sm->type = DETECT_HELLOWORLD; + sm->ctx = (void *)helloworldd; + + SigMatchAppendSMToList(s, sm, DETECT_SM_LIST_MATCH); + s->flags |= SIG_FLAG_REQUIRE_PACKET; + + return 0; + +error: + if (helloworldd != NULL) + DetectHelloWorldFree(helloworldd); + if (sm != NULL) + SCFree(sm); + return -1; +} + +/** + * \brief this function will free memory associated with DetectHelloWorldData + * + * \param ptr pointer to DetectHelloWorldData + */ +void DetectHelloWorldFree(void *ptr) { + DetectHelloWorldData *helloworldd = (DetectHelloWorldData *)ptr; + SCFree(helloworldd); +} + +#ifdef UNITTESTS + +/** + * \test description of the test + */ + +static int DetectHelloWorldParseTest01 (void) { + DetectHelloWorldData *helloworldd = NULL; + uint8_t res = 0; + + helloworldd = DetectHelloWorldParse("1,10"); + if (helloworldd != NULL) { + if (helloworldd->helloworld1 == 1 && helloworldd->helloworld2 == 10) + res = 1; + + DetectHelloWorldFree(helloworldd); + } + + return res; +} + +static int DetectHelloWorldSignatureTest01 (void) { + uint8_t res = 0; + + DetectEngineCtx *de_ctx = DetectEngineCtxInit(); + if (de_ctx == NULL) + goto end; + + Signature *sig = DetectEngineAppendSig(de_ctx, "alert ip any any -> any any (helloworld:1,10; sid:1; rev:1;)"); + if (sig == NULL) { + printf("parsing signature failed: "); + goto end; + } + + /* if we get here, all conditions pass */ + res = 1; +end: + if (de_ctx != NULL) + DetectEngineCtxFree(de_ctx); + return res; +} + +#endif /* UNITTESTS */ + +/** + * \brief this function registers unit tests for DetectHelloWorld + */ +void DetectHelloWorldRegisterTests(void) { +#ifdef UNITTESTS + UtRegisterTest("DetectHelloWorldParseTest01", + DetectHelloWorldParseTest01, 1); + UtRegisterTest("DetectHelloWorldSignatureTest01", + DetectHelloWorldSignatureTest01, 1); +#endif /* UNITTESTS */ +} diff --git a/src/detect-helloworld.h b/src/detect-helloworld.h new file mode 100644 index 0000000..c9edf37 --- /dev/null +++ b/src/detect-helloworld.h @@ -0,0 +1,35 @@ +/* Copyright (C) 2012 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 Yourname + */ + +#ifndef _DETECT_HELLOWORLD_H +#define _DETECT_HELLOWORLD_H + +typedef struct DetectHelloWorldData_ { + uint8_t helloworld1; /**< first value */ + uint8_t helloworld2; /**< second value */ +} DetectHelloWorldData; + +void DetectHelloWorldRegister(void); + +#endif /* _DETECT_HELLOWORLD_H */ + diff --git a/src/detect.c b/src/detect.c index c9224d6..16b7f91 100644 --- a/src/detect.c +++ b/src/detect.c @@ -144,6 +144,7 @@ #include "detect-app-layer-event.h" #include "detect-luajit.h" #include "detect-iprep.h" +#include "detect-helloworld.h" #include "util-rule-vars.h" @@ -4781,6 +4782,7 @@ void SigTableSetup(void) { DetectHttpUARegister(); DetectLuajitRegister(); DetectIPRepRegister(); + DetectHelloWorldRegister(); uint8_t i = 0; for (i = 0; i < DETECT_TBLSIZE; i++) { diff --git a/src/detect.h b/src/detect.h index 3ebcb8a..5dca075 100644 --- a/src/detect.h +++ b/src/detect.h @@ -1097,6 +1097,8 @@ enum { DETECT_LUAJIT, DETECT_IPREP, + DETECT_HELLOWORLD, + /* make sure this stays last */ DETECT_TBLSIZE, }; -- 1.7.10.4