/* Copyright (C) 2007-2012 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 Eileen Donlon * * Rule analyzer for the detection engine */ #include "suricata-common.h" #include "suricata.h" #include "detect.h" #include "detect-parse.h" #include "detect-engine.h" #include "detect-engine-analyzer.h" #include "detect-engine-mpm.h" #include "conf.h" #include "detect-content.h" #include "detect-flow.h" #include "detect-flags.h" #include "util-print.h" static int rule_warnings_only = 0; static FILE *rule_engine_analysis_FD = NULL; static FILE *fp_engine_analysis_FD = NULL; static pcre *percent_re = NULL; static pcre_extra *percent_re_study = NULL; static char log_path[PATH_MAX]; typedef struct FpPatternStats_ { uint16_t min; uint16_t max; uint32_t cnt; uint64_t tot; } FpPatternStats; static FpPatternStats fp_pattern_stats[DETECT_SM_LIST_MAX]; static void FpPatternStatsAdd(int list, uint16_t patlen) { if (list < 0 || list >= DETECT_SM_LIST_MAX) return; FpPatternStats *f = &fp_pattern_stats[list]; if (f->min == 0) f->min = patlen; else if (patlen < f->min) f->min = patlen; if (patlen > f->max) f->max = patlen; f->cnt++; f->tot += patlen; } void EngineAnalysisFP(Signature *s, char *line) { int fast_pattern_set = 0; int fast_pattern_only_set = 0; int fast_pattern_chop_set = 0; DetectContentData *fp_cd = NULL; SigMatch *mpm_sm = s->mpm_sm; if (mpm_sm != NULL) { fp_cd = (DetectContentData *)mpm_sm->ctx; if (fp_cd->flags & DETECT_CONTENT_FAST_PATTERN) { fast_pattern_set = 1; if (fp_cd->flags & DETECT_CONTENT_FAST_PATTERN_ONLY) { fast_pattern_only_set = 1; } else if (fp_cd->flags & DETECT_CONTENT_FAST_PATTERN_CHOP) { fast_pattern_chop_set = 1; } } } fprintf(fp_engine_analysis_FD, "== Sid: %u ==\n", s->id); fprintf(fp_engine_analysis_FD, "%s\n", line); fprintf(fp_engine_analysis_FD, " Fast Pattern analysis:\n"); if (fp_cd == NULL) { fprintf(fp_engine_analysis_FD, " No content present\n"); fprintf(fp_engine_analysis_FD, "\n"); return; } fprintf(fp_engine_analysis_FD, " Fast pattern matcher: "); int list_type = SigMatchListSMBelongsTo(s, mpm_sm); if (list_type == DETECT_SM_LIST_PMATCH) fprintf(fp_engine_analysis_FD, "content\n"); else if (list_type == DETECT_SM_LIST_UMATCH) fprintf(fp_engine_analysis_FD, "http uri content\n"); else if (list_type == DETECT_SM_LIST_HRUDMATCH) fprintf(fp_engine_analysis_FD, "http raw uri content\n"); else if (list_type == DETECT_SM_LIST_HHDMATCH) fprintf(fp_engine_analysis_FD, "http header content\n"); else if (list_type == DETECT_SM_LIST_HRHDMATCH) fprintf(fp_engine_analysis_FD, "http raw header content\n"); else if (list_type == DETECT_SM_LIST_HMDMATCH) fprintf(fp_engine_analysis_FD, "http method content\n"); else if (list_type == DETECT_SM_LIST_HCDMATCH) fprintf(fp_engine_analysis_FD, "http cookie content\n"); else if (list_type == DETECT_SM_LIST_HCBDMATCH) fprintf(fp_engine_analysis_FD, "http client body content\n"); else if (list_type == DETECT_SM_LIST_FILEDATA) fprintf(fp_engine_analysis_FD, "http server body content\n"); else if (list_type == DETECT_SM_LIST_HSCDMATCH) fprintf(fp_engine_analysis_FD, "http stat code content\n"); else if (list_type == DETECT_SM_LIST_HSMDMATCH) fprintf(fp_engine_analysis_FD, "http stat msg content\n"); else if (list_type == DETECT_SM_LIST_HUADMATCH) fprintf(fp_engine_analysis_FD, "http user agent content\n"); int flags_set = 0; fprintf(fp_engine_analysis_FD, " Flags:"); if (fp_cd->flags & DETECT_CONTENT_OFFSET) { fprintf(fp_engine_analysis_FD, " Offset"); flags_set = 1; } if (fp_cd->flags & DETECT_CONTENT_DEPTH) { fprintf(fp_engine_analysis_FD, " Depth"); flags_set = 1; } if (fp_cd->flags & DETECT_CONTENT_WITHIN) { fprintf(fp_engine_analysis_FD, " Within"); flags_set = 1; } if (fp_cd->flags & DETECT_CONTENT_DISTANCE) { fprintf(fp_engine_analysis_FD, " Distance"); flags_set = 1; } if (fp_cd->flags & DETECT_CONTENT_NOCASE) { fprintf(fp_engine_analysis_FD, " Nocase"); flags_set = 1; } if (fp_cd->flags & DETECT_CONTENT_NEGATED) { fprintf(fp_engine_analysis_FD, " Negated"); flags_set = 1; } if (flags_set == 0) fprintf(fp_engine_analysis_FD, " None"); fprintf(fp_engine_analysis_FD, "\n"); fprintf(fp_engine_analysis_FD, " Fast pattern set: %s\n", fast_pattern_set ? "yes" : "no"); fprintf(fp_engine_analysis_FD, " Fast pattern only set: %s\n", fast_pattern_only_set ? "yes" : "no"); fprintf(fp_engine_analysis_FD, " Fast pattern chop set: %s\n", fast_pattern_chop_set ? "yes" : "no"); if (fast_pattern_chop_set) { fprintf(fp_engine_analysis_FD, " Fast pattern offset, length: %u, %u\n", fp_cd->fp_chop_offset, fp_cd->fp_chop_len); } uint16_t patlen = fp_cd->content_len; uint8_t *pat = SCMalloc(fp_cd->content_len + 1); if (unlikely(pat == NULL)) { SCLogError(SC_ERR_MEM_ALLOC, "Error allocating memory"); exit(EXIT_FAILURE); } memcpy(pat, fp_cd->content, fp_cd->content_len); pat[fp_cd->content_len] = '\0'; fprintf(fp_engine_analysis_FD, " Original content: "); PrintRawUriFp(fp_engine_analysis_FD, pat, patlen); fprintf(fp_engine_analysis_FD, "\n"); if (fast_pattern_chop_set) { SCFree(pat); patlen = fp_cd->fp_chop_len; pat = SCMalloc(fp_cd->fp_chop_len + 1); if (unlikely(pat == NULL)) { exit(EXIT_FAILURE); } memcpy(pat, fp_cd->content + fp_cd->fp_chop_offset, fp_cd->fp_chop_len); pat[fp_cd->fp_chop_len] = '\0'; fprintf(fp_engine_analysis_FD, " Final content: "); PrintRawUriFp(fp_engine_analysis_FD, pat, patlen); fprintf(fp_engine_analysis_FD, "\n"); FpPatternStatsAdd(list_type, patlen); } else { fprintf(fp_engine_analysis_FD, " Final content: "); PrintRawUriFp(fp_engine_analysis_FD, pat, patlen); fprintf(fp_engine_analysis_FD, "\n"); FpPatternStatsAdd(list_type, patlen); } SCFree(pat); fprintf(fp_engine_analysis_FD, "\n"); return; } /** * \brief Sets up the fast pattern analyzer according to the config. * * \retval 1 If rule analyzer successfully enabled. * \retval 0 If not enabled. */ int SetupFPAnalyzer(void) { int fp_engine_analysis_set = 0; if ((ConfGetBool("engine-analysis.rules-fast-pattern", &fp_engine_analysis_set)) == 0) { return 0; } if (fp_engine_analysis_set == 0) return 0; char *log_dir; log_dir = ConfigGetLogDirectory(); snprintf(log_path, sizeof(log_path), "%s/%s", log_dir, "rules_fast_pattern.txt"); fp_engine_analysis_FD = fopen(log_path, "w"); if (fp_engine_analysis_FD == NULL) { SCLogError(SC_ERR_FOPEN, "failed to open %s: %s", log_path, strerror(errno)); return 0; } SCLogInfo("Engine-Analysis for fast_pattern printed to file - %s", log_path); struct timeval tval; struct tm *tms; gettimeofday(&tval, NULL); struct tm local_tm; tms = SCLocalTime(tval.tv_sec, &local_tm); fprintf(fp_engine_analysis_FD, "----------------------------------------------" "---------------------\n"); fprintf(fp_engine_analysis_FD, "Date: %" PRId32 "/%" PRId32 "/%04d -- " "%02d:%02d:%02d\n", tms->tm_mday, tms->tm_mon + 1, tms->tm_year + 1900, tms->tm_hour, tms->tm_min, tms->tm_sec); fprintf(fp_engine_analysis_FD, "----------------------------------------------" "---------------------\n"); memset(&fp_pattern_stats, 0, sizeof(fp_pattern_stats)); return 1; } /** * \brief Sets up the rule analyzer according to the config * \retval 1 if rule analyzer successfully enabled * \retval 0 if not enabled */ int SetupRuleAnalyzer(void) { ConfNode *conf = ConfGetNode("engine-analysis"); int enabled = 0; if (conf != NULL) { const char *value = ConfNodeLookupChildValue(conf, "rules"); if (value && ConfValIsTrue(value)) { enabled = 1; } else if (value && strcasecmp(value, "warnings-only") == 0) { enabled = 1; rule_warnings_only = 1; } if (enabled) { char *log_dir; log_dir = ConfigGetLogDirectory(); snprintf(log_path, sizeof(log_path), "%s/%s", log_dir, "rules_analysis.txt"); rule_engine_analysis_FD = fopen(log_path, "w"); if (rule_engine_analysis_FD == NULL) { SCLogError(SC_ERR_FOPEN, "failed to open %s: %s", log_path, strerror(errno)); return 0; } SCLogInfo("Engine-Analysis for rules printed to file - %s", log_path); struct timeval tval; struct tm *tms; gettimeofday(&tval, NULL); struct tm local_tm; tms = SCLocalTime(tval.tv_sec, &local_tm); fprintf(rule_engine_analysis_FD, "----------------------------------------------" "---------------------\n"); fprintf(rule_engine_analysis_FD, "Date: %" PRId32 "/%" PRId32 "/%04d -- " "%02d:%02d:%02d\n", tms->tm_mday, tms->tm_mon + 1, tms->tm_year + 1900, tms->tm_hour, tms->tm_min, tms->tm_sec); fprintf(rule_engine_analysis_FD, "----------------------------------------------" "---------------------\n"); /*compile regex's for rule analysis*/ if (PerCentEncodingSetup()== 0) { fprintf(rule_engine_analysis_FD, "Error compiling regex; can't check for percent encoding in normalized http content.\n"); } } } else { SCLogInfo("Conf parameter \"engine-analysis.rules\" not found. " "Defaulting to not printing the rules analysis report."); } if (!enabled) { SCLogInfo("Engine-Analysis for rules disabled in conf file."); return 0; } return 1; } void CleanupFPAnalyzer(void) { fprintf(fp_engine_analysis_FD, "============\n" "Summary:\n============\n"); int i; for (i = 0; i < DETECT_SM_LIST_MAX; i++) { FpPatternStats *f = &fp_pattern_stats[i]; if (f->cnt == 0) continue; fprintf(fp_engine_analysis_FD, "%s, smallest pattern %u byte(s), longest pattern %u byte(s), number of patterns %u, avg pattern len %.2f byte(s)\n", DetectSigmatchListEnumToString(i), f->min, f->max, f->cnt, (float)((double)f->tot/(float)f->cnt)); } if (fp_engine_analysis_FD != NULL) { fclose(fp_engine_analysis_FD); fp_engine_analysis_FD = NULL; } return; } void CleanupRuleAnalyzer(void) { if (rule_engine_analysis_FD != NULL) { SCLogInfo("Engine-Analyis for rules printed to file - %s", log_path); fclose(rule_engine_analysis_FD); rule_engine_analysis_FD = NULL; } } /** * \brief Compiles regex for rule analysis * \retval 1 if successful * \retval 0 if on error */ int PerCentEncodingSetup () { #define DETECT_PERCENT_ENCODING_REGEX "%[0-9|a-f|A-F]{2}" const char *eb = NULL; int eo = 0; int opts = 0; //PCRE_NEWLINE_ANY?? percent_re = pcre_compile(DETECT_PERCENT_ENCODING_REGEX, opts, &eb, &eo, NULL); if (percent_re == NULL) { SCLogError(SC_ERR_PCRE_COMPILE, "Compile of \"%s\" failed at offset %" PRId32 ": %s", DETECT_PERCENT_ENCODING_REGEX, eo, eb); return 0; } percent_re_study = pcre_study(percent_re, 0, &eb); if (eb != NULL) { SCLogError(SC_ERR_PCRE_STUDY, "pcre study failed: %s", eb); return 0; } return 1; } /** * \brief Checks for % encoding in content. * \param Pointer to content * \retval number of matches if content has % encoding * \retval 0 if it doesn't have % encoding * \retval -1 on error */ int PerCentEncodingMatch (uint8_t *content, uint8_t content_len) { #define MAX_ENCODED_CHARS 240 int ret = 0; int ov[MAX_ENCODED_CHARS]; ret = pcre_exec(percent_re, percent_re_study, (char *)content, content_len, 0, 0, ov, MAX_ENCODED_CHARS); if (ret == -1) { return 0; } else if (ret < -1) { SCLogError(SC_ERR_PCRE_MATCH, "Error parsing content - %s; error code is %d", content, ret); return -1; } return ret; } static void EngineAnalysisRulesPrintFP(Signature *s) { DetectContentData *fp_cd = NULL; SigMatch *mpm_sm = s->mpm_sm; if (mpm_sm != NULL) { fp_cd = (DetectContentData *)mpm_sm->ctx; } if (fp_cd == NULL) { return; } uint16_t patlen = fp_cd->content_len; uint8_t *pat = SCMalloc(fp_cd->content_len + 1); if (unlikely(pat == NULL)) { SCLogError(SC_ERR_MEM_ALLOC, "Error allocating memory"); exit(EXIT_FAILURE); } memcpy(pat, fp_cd->content, fp_cd->content_len); pat[fp_cd->content_len] = '\0'; if (fp_cd->flags & DETECT_CONTENT_FAST_PATTERN_CHOP) { SCFree(pat); patlen = fp_cd->fp_chop_len; pat = SCMalloc(fp_cd->fp_chop_len + 1); if (unlikely(pat == NULL)) { exit(EXIT_FAILURE); } memcpy(pat, fp_cd->content + fp_cd->fp_chop_offset, fp_cd->fp_chop_len); pat[fp_cd->fp_chop_len] = '\0'; fprintf(rule_engine_analysis_FD, " Fast Pattern \""); PrintRawUriFp(rule_engine_analysis_FD, pat, patlen); } else { fprintf(rule_engine_analysis_FD, " Fast Pattern \""); PrintRawUriFp(rule_engine_analysis_FD, pat, patlen); } SCFree(pat); fprintf(rule_engine_analysis_FD, "\" on \""); int list_type = SigMatchListSMBelongsTo(s, mpm_sm); if (list_type == DETECT_SM_LIST_PMATCH) { int payload = 0; int stream = 0; if (SignatureHasPacketContent(s)) payload = 1; if (SignatureHasStreamContent(s)) stream = 1; fprintf(rule_engine_analysis_FD, "%s", payload ? (stream ? "payload and reassembled stream" : "payload") : "reassembled stream"); } else if (list_type == DETECT_SM_LIST_UMATCH) fprintf(rule_engine_analysis_FD, "http uri content"); else if (list_type == DETECT_SM_LIST_HRUDMATCH) fprintf(rule_engine_analysis_FD, "http raw uri content"); else if (list_type == DETECT_SM_LIST_HHDMATCH) fprintf(rule_engine_analysis_FD, "http header content"); else if (list_type == DETECT_SM_LIST_HRHDMATCH) fprintf(rule_engine_analysis_FD, "http raw header content"); else if (list_type == DETECT_SM_LIST_HMDMATCH) fprintf(rule_engine_analysis_FD, "http method content"); else if (list_type == DETECT_SM_LIST_HCDMATCH) fprintf(rule_engine_analysis_FD, "http cookie content"); else if (list_type == DETECT_SM_LIST_HCBDMATCH) fprintf(rule_engine_analysis_FD, "http client body content"); else if (list_type == DETECT_SM_LIST_FILEDATA) fprintf(rule_engine_analysis_FD, "http server body content"); else if (list_type == DETECT_SM_LIST_HSCDMATCH) fprintf(rule_engine_analysis_FD, "http stat code content"); else if (list_type == DETECT_SM_LIST_HSMDMATCH) fprintf(rule_engine_analysis_FD, "http stat msg content"); else if (list_type == DETECT_SM_LIST_HUADMATCH) fprintf(rule_engine_analysis_FD, "http user agent content"); else if (list_type == DETECT_SM_LIST_DNSQUERYNAME_MATCH) fprintf(rule_engine_analysis_FD, "dns query name content"); fprintf(rule_engine_analysis_FD, "\" buffer.\n"); return; } void EngineAnalysisRulesFailure(char *line, char *file, int lineno) { fprintf(rule_engine_analysis_FD, "== Sid: UNKNOWN ==\n"); fprintf(rule_engine_analysis_FD, "%s\n", line); fprintf(rule_engine_analysis_FD, " FAILURE: invalid rule.\n"); fprintf(rule_engine_analysis_FD, " File: %s.\n", file); fprintf(rule_engine_analysis_FD, " Line: %d.\n", lineno); fprintf(rule_engine_analysis_FD, "\n"); } /** * \brief Prints analysis of loaded rules. * * Warns if potential rule issues are detected. For example, * warns if a rule uses a construct that may perform poorly, * e.g. pcre without content or with http_method content only; * warns if a rule uses a construct that may not be consistent with intent, * e.g. client side ports only, http and content without any http_* modifiers, etc. * * \param s Pointer to the signature. */ void EngineAnalysisRules(Signature *s, char *line) { uint32_t rule_bidirectional = 0; uint32_t rule_pcre = 0; uint32_t rule_pcre_http = 0; uint32_t rule_content = 0; uint32_t rule_flow = 0; uint32_t rule_flags = 0; uint32_t rule_flow_toserver = 0; uint32_t rule_flow_toclient = 0; uint32_t rule_flow_nostream = 0; uint32_t rule_ipv4_only = 0; uint32_t rule_ipv6_only = 0; uint32_t rule_flowbits = 0; uint32_t rule_flowint = 0; //uint32_t rule_flowvar = 0; uint32_t rule_content_http = 0; uint32_t rule_content_offset_depth = 0; uint32_t list_id = 0; uint32_t rule_warning = 0; uint32_t raw_http_buf = 0; uint32_t norm_http_buf = 0; uint32_t stream_buf = 0; uint32_t packet_buf = 0; uint32_t http_header_buf = 0; uint32_t http_uri_buf = 0; uint32_t http_method_buf = 0; uint32_t http_cookie_buf = 0; uint32_t http_client_body_buf = 0; uint32_t http_server_body_buf = 0; uint32_t http_stat_code_buf = 0; uint32_t http_stat_msg_buf = 0; uint32_t http_raw_header_buf = 0; uint32_t http_raw_uri_buf = 0; uint32_t http_ua_buf = 0; uint32_t warn_pcre_no_content = 0; uint32_t warn_pcre_http_content = 0; uint32_t warn_pcre_http = 0; uint32_t warn_content_http_content = 0; uint32_t warn_content_http = 0; uint32_t warn_tcp_no_flow = 0; uint32_t warn_client_ports = 0; uint32_t warn_direction = 0; uint32_t warn_method_toclient = 0; uint32_t warn_method_serverbody = 0; uint32_t warn_pcre_method = 0; uint32_t warn_encoding_norm_http_buf = 0; uint32_t warn_offset_depth_pkt_stream = 0; uint32_t warn_offset_depth_alproto = 0; uint32_t warn_non_alproto_fp_for_alproto_sig = 0; if (s->init_flags & SIG_FLAG_INIT_BIDIREC) { rule_bidirectional = 1; } if (s->flags & SIG_FLAG_REQUIRE_PACKET) { packet_buf += 1; } if (s->flags & SIG_FLAG_REQUIRE_STREAM) { stream_buf += 1; } if (s->proto.flags & DETECT_PROTO_IPV4) { rule_ipv4_only += 1; } if (s->proto.flags & DETECT_PROTO_IPV6) { rule_ipv6_only += 1; } for (list_id = 0; list_id < DETECT_SM_LIST_MAX; list_id++) { SigMatch *sm = NULL; for (sm = s->sm_lists[list_id]; sm != NULL; sm = sm->next) { if (sm->type == DETECT_PCRE) { if (list_id == DETECT_SM_LIST_HCBDMATCH) { rule_pcre_http += 1; http_client_body_buf += 1; raw_http_buf += 1; } else if (list_id == DETECT_SM_LIST_UMATCH) { rule_pcre_http += 1; norm_http_buf += 1; http_uri_buf += 1; } else if (list_id == DETECT_SM_LIST_HHDMATCH) { rule_pcre_http += 1; norm_http_buf += 1; http_header_buf += 1; } else if (list_id == DETECT_SM_LIST_HCDMATCH) { rule_pcre_http += 1; norm_http_buf += 1; http_cookie_buf += 1; } else if (list_id == DETECT_SM_LIST_FILEDATA) { rule_pcre_http += 1; http_server_body_buf += 1; raw_http_buf += 1; } else if (list_id == DETECT_SM_LIST_HRHDMATCH) { rule_pcre_http += 1; raw_http_buf += 1; http_raw_header_buf += 1; } else if (list_id == DETECT_SM_LIST_HMDMATCH) { rule_pcre_http += 1; raw_http_buf += 1; http_method_buf += 1; } else if (list_id == DETECT_SM_LIST_HRUDMATCH) { rule_pcre_http += 1; raw_http_buf += 1; http_raw_uri_buf += 1; } else if (list_id == DETECT_SM_LIST_HSMDMATCH) { rule_pcre_http += 1; raw_http_buf += 1; http_stat_msg_buf += 1; } else if (list_id == DETECT_SM_LIST_HSCDMATCH) { rule_pcre_http += 1; raw_http_buf += 1; http_stat_code_buf += 1; } else if (list_id == DETECT_SM_LIST_HUADMATCH) { rule_pcre_http += 1; norm_http_buf += 1; http_ua_buf += 1; } else { rule_pcre += 1; } } else if (sm->type == DETECT_CONTENT) { if (list_id == DETECT_SM_LIST_UMATCH || list_id == DETECT_SM_LIST_HHDMATCH || list_id == DETECT_SM_LIST_HCDMATCH) { rule_content_http += 1; norm_http_buf += 1; DetectContentData *cd = (DetectContentData *)sm->ctx; if (cd != NULL && PerCentEncodingMatch(cd->content, cd->content_len) > 0) { warn_encoding_norm_http_buf += 1; rule_warning += 1; } if (list_id == DETECT_SM_LIST_UMATCH) { http_uri_buf += 1; } else if (list_id == DETECT_SM_LIST_HHDMATCH) { http_header_buf += 1; } else if (list_id == DETECT_SM_LIST_HCDMATCH) { http_cookie_buf += 1; } } else if (list_id == DETECT_SM_LIST_HCBDMATCH) { rule_content_http += 1; raw_http_buf += 1; http_client_body_buf += 1; } else if (list_id == DETECT_SM_LIST_FILEDATA) { rule_content_http += 1; raw_http_buf += 1; http_server_body_buf += 1; } else if (list_id == DETECT_SM_LIST_HRHDMATCH) { rule_content_http += 1; raw_http_buf += 1; http_raw_header_buf += 1; } else if (list_id == DETECT_SM_LIST_HRUDMATCH) { rule_content_http += 1; raw_http_buf += 1; http_raw_uri_buf += 1; } else if (list_id == DETECT_SM_LIST_HSMDMATCH) { rule_content_http += 1; raw_http_buf += 1; http_stat_msg_buf += 1; } else if (list_id == DETECT_SM_LIST_HSCDMATCH) { rule_content_http += 1; raw_http_buf += 1; http_stat_code_buf += 1; } else if (list_id == DETECT_SM_LIST_HMDMATCH) { rule_content_http += 1; raw_http_buf += 1; http_method_buf += 1; } else if (list_id == DETECT_SM_LIST_PMATCH) { rule_content += 1; DetectContentData *cd = (DetectContentData *)sm->ctx; if (cd->flags & (DETECT_CONTENT_OFFSET | DETECT_CONTENT_DEPTH)) { rule_content_offset_depth++; } } } else if (sm->type == DETECT_FLOW) { rule_flow += 1; if ((s->flags & SIG_FLAG_TOSERVER) && !(s->flags & SIG_FLAG_TOCLIENT)) { rule_flow_toserver = 1; } else if ((s->flags & SIG_FLAG_TOCLIENT) && !(s->flags & SIG_FLAG_TOSERVER)) { rule_flow_toclient = 1; } DetectFlowData *fd = (DetectFlowData *)sm->ctx; if (fd != NULL) { if (fd->flags & DETECT_FLOW_FLAG_NOSTREAM) rule_flow_nostream = 1; } } else if (sm->type == DETECT_FLOWBITS) { if (list_id == DETECT_SM_LIST_MATCH) { rule_flowbits += 1; } } else if (sm->type == DETECT_FLOWINT) { if (list_id == DETECT_SM_LIST_MATCH) { rule_flowint += 1; } } else if (sm->type == DETECT_FLAGS) { DetectFlagsData *fd = (DetectFlagsData *)sm->ctx; if (fd != NULL) { rule_flags = 1; } } } /* for (sm = s->sm_lists[list_id]; sm != NULL; sm = sm->next) */ } /* for ( ; list_id < DETECT_SM_LIST_MAX; list_id++) */ if (rule_pcre > 0 && rule_content == 0 && rule_content_http == 0) { rule_warning += 1; warn_pcre_no_content = 1; } if (rule_content_http > 0 && rule_pcre > 0 && rule_pcre_http == 0) { rule_warning += 1; warn_pcre_http_content = 1; } else if (s->alproto == ALPROTO_HTTP && rule_pcre > 0 && rule_pcre_http == 0) { rule_warning += 1; warn_pcre_http = 1; } if (rule_content > 0 && rule_content_http > 0) { rule_warning += 1; warn_content_http_content = 1; } if (s->alproto == ALPROTO_HTTP && rule_content > 0 && rule_content_http == 0) { rule_warning += 1; warn_content_http = 1; } if (rule_content == 1) { //todo: warning if content is weak, separate warning for pcre + weak content } if (rule_flow == 0 && rule_flags == 0 && !(s->proto.flags & DETECT_PROTO_ANY) && DetectProtoContainsProto(&s->proto, IPPROTO_TCP) && (rule_content || rule_content_http || rule_pcre || rule_pcre_http || rule_flowbits)) { rule_warning += 1; warn_tcp_no_flow = 1; } if (rule_flow && !rule_bidirectional && (rule_flow_toserver || rule_flow_toclient) && !((s->flags & SIG_FLAG_SP_ANY) && (s->flags & SIG_FLAG_DP_ANY))) { if (((s->flags & SIG_FLAG_TOSERVER) && !(s->flags & SIG_FLAG_SP_ANY) && (s->flags & SIG_FLAG_DP_ANY)) || ((s->flags & SIG_FLAG_TOCLIENT) && !(s->flags & SIG_FLAG_DP_ANY) && (s->flags & SIG_FLAG_SP_ANY))) { rule_warning += 1; warn_client_ports = 1; } } if (rule_flow && rule_bidirectional && (rule_flow_toserver || rule_flow_toclient)) { rule_warning += 1; warn_direction = 1; } if (http_method_buf) { if (rule_flow && rule_flow_toclient) { rule_warning += 1; warn_method_toclient = 1; } if (http_server_body_buf) { rule_warning += 1; warn_method_serverbody = 1; } if (rule_content == 0 && rule_content_http == 0 && (rule_pcre > 0 || rule_pcre_http > 0)) { rule_warning += 1; warn_pcre_method = 1; } } if (rule_content_offset_depth > 0 && stream_buf && packet_buf) { rule_warning += 1; warn_offset_depth_pkt_stream = 1; } if (rule_content_offset_depth > 0 && !stream_buf && packet_buf && s->alproto != ALPROTO_UNKNOWN) { rule_warning += 1; warn_offset_depth_alproto = 1; } if (s->mpm_sm != NULL && s->alproto == ALPROTO_HTTP && SigMatchListSMBelongsTo(s, s->mpm_sm) == DETECT_SM_LIST_PMATCH) { rule_warning += 1; warn_non_alproto_fp_for_alproto_sig = 1; } if (!rule_warnings_only || (rule_warnings_only && rule_warning > 0)) { fprintf(rule_engine_analysis_FD, "== Sid: %u ==\n", s->id); fprintf(rule_engine_analysis_FD, "%s\n", line); if (s->flags & SIG_FLAG_IPONLY) fprintf(rule_engine_analysis_FD, " Rule is ip only.\n"); if (rule_ipv6_only) fprintf(rule_engine_analysis_FD, " Rule is IPv6 only.\n"); if (rule_ipv4_only) fprintf(rule_engine_analysis_FD, " Rule is IPv4 only.\n"); if (packet_buf) fprintf(rule_engine_analysis_FD, " Rule matches on packets.\n"); if (!rule_flow_nostream && stream_buf && (rule_flow || rule_flowbits || rule_content || rule_pcre)) { fprintf(rule_engine_analysis_FD, " Rule matches on reassembled stream.\n"); } if (http_uri_buf) fprintf(rule_engine_analysis_FD, " Rule matches on http uri buffer.\n"); if (http_header_buf) fprintf(rule_engine_analysis_FD, " Rule matches on http header buffer.\n"); if (http_cookie_buf) fprintf(rule_engine_analysis_FD, " Rule matches on http cookie buffer.\n"); if (http_raw_uri_buf) fprintf(rule_engine_analysis_FD, " Rule matches on http raw uri buffer.\n"); if (http_raw_header_buf) fprintf(rule_engine_analysis_FD, " Rule matches on http raw header buffer.\n"); if (http_method_buf) fprintf(rule_engine_analysis_FD, " Rule matches on http method buffer.\n"); if (http_server_body_buf) fprintf(rule_engine_analysis_FD, " Rule matches on http server body buffer.\n"); if (http_client_body_buf) fprintf(rule_engine_analysis_FD, " Rule matches on http client body buffer.\n"); if (http_stat_msg_buf) fprintf(rule_engine_analysis_FD, " Rule matches on http stat msg buffer.\n"); if (http_stat_code_buf) fprintf(rule_engine_analysis_FD, " Rule matches on http stat code buffer.\n"); if (http_ua_buf) fprintf(rule_engine_analysis_FD, " Rule matches on http user agent buffer.\n"); if (s->alproto != ALPROTO_UNKNOWN) { fprintf(rule_engine_analysis_FD, " App layer protocol is %s.\n", AppProtoToString(s->alproto)); } if (rule_content || rule_content_http || rule_pcre || rule_pcre_http) { fprintf(rule_engine_analysis_FD, " Rule contains %d content options, %d http content options, %d pcre options, and %d pcre options with http modifiers.\n", rule_content, rule_content_http, rule_pcre, rule_pcre_http); } /* print fast pattern info */ EngineAnalysisRulesPrintFP(s); /* this is where the warnings start */ if (warn_pcre_no_content /*rule_pcre > 0 && rule_content == 0 && rule_content_http == 0*/) { fprintf(rule_engine_analysis_FD, " Warning: Rule uses pcre without a content option present.\n" " -Consider adding a content to improve performance of this rule.\n"); } if (warn_pcre_http_content /*rule_content_http > 0 && rule_pcre > 0 && rule_pcre_http == 0*/) { fprintf(rule_engine_analysis_FD, " Warning: Rule uses content options with http_* and pcre options without http modifiers.\n" " -Consider adding http pcre modifier.\n"); } else if (warn_pcre_http /*s->alproto == ALPROTO_HTTP && rule_pcre > 0 && rule_pcre_http == 0*/) { fprintf(rule_engine_analysis_FD, " Warning: Rule app layer protocol is http, but pcre options do not have http modifiers.\n" " -Consider adding http pcre modifiers.\n"); } if (warn_content_http_content /*rule_content > 0 && rule_content_http > 0*/) { fprintf(rule_engine_analysis_FD, " Warning: Rule contains content with http_* and content without http_*.\n" " -Consider adding http content modifiers.\n"); } if (warn_content_http /*s->alproto == ALPROTO_HTTP && rule_content > 0 && rule_content_http == 0*/) { fprintf(rule_engine_analysis_FD, " Warning: Rule app layer protocol is http, but content options do not have http_* modifiers.\n" " -Consider adding http content modifiers.\n"); } if (rule_content == 1) { //todo: warning if content is weak, separate warning for pcre + weak content } if (warn_encoding_norm_http_buf) { fprintf(rule_engine_analysis_FD, " Warning: Rule may contain percent encoded content for a normalized http buffer match.\n"); } if (warn_tcp_no_flow /*rule_flow == 0 && rule_flow == 0 && !(s->proto.flags & DETECT_PROTO_ANY) && DetectProtoContainsProto(&s->proto, IPPROTO_TCP)*/) { fprintf(rule_engine_analysis_FD, " Warning: TCP rule without a flow or flags option.\n" " -Consider adding flow or flags to improve performance of this rule.\n"); } if (warn_client_ports /*rule_flow && !rule_bidirectional && (rule_flow_toserver || rule_flow_toclient) && !((s->flags & SIG_FLAG_SP_ANY) && (s->flags & SIG_FLAG_DP_ANY))) if (((s->flags & SIG_FLAG_TOSERVER) && !(s->flags & SIG_FLAG_SP_ANY) && (s->flags & SIG_FLAG_DP_ANY)) || ((s->flags & SIG_FLAG_TOCLIENT) && !(s->flags & SIG_FLAG_DP_ANY) && (s->flags & SIG_FLAG_SP_ANY))*/) { fprintf(rule_engine_analysis_FD, " Warning: Rule contains ports or port variables only on the client side.\n" " -Flow direction possibly inconsistent with rule.\n"); } if (warn_direction /*rule_flow && rule_bidirectional && (rule_flow_toserver || rule_flow_toclient)*/) { fprintf(rule_engine_analysis_FD, " Warning: Rule is bidirectional and has a flow option with a specific direction.\n"); } if (warn_method_toclient /*http_method_buf && rule_flow && rule_flow_toclient*/) { fprintf(rule_engine_analysis_FD, " Warning: Rule uses content or pcre for http_method with flow:to_client or from_server\n"); } if (warn_method_serverbody /*http_method_buf && http_server_body_buf*/) { fprintf(rule_engine_analysis_FD, " Warning: Rule uses content or pcre for http_method with content or pcre for http_server_body.\n"); } if (warn_pcre_method /*http_method_buf && rule_content == 0 && rule_content_http == 0 && (rule_pcre > 0 || rule_pcre_http > 0)*/) { fprintf(rule_engine_analysis_FD, " Warning: Rule uses pcre with only a http_method content; possible performance issue.\n"); } if (warn_offset_depth_pkt_stream) { fprintf(rule_engine_analysis_FD, " Warning: Rule has depth" "/offset with raw content keywords. Please note the " "offset/depth will be checked against both packet " "payloads and stream. If you meant to have the offset/" "depth checked against just the payload, you can update " "the signature as \"alert tcp-pkt...\"\n"); } if (warn_offset_depth_alproto) { fprintf(rule_engine_analysis_FD, " Warning: Rule has " "offset/depth set along with a match on a specific " "app layer protocol - %d. This can lead to FNs if we " "have a offset/depth content match on a packet payload " "before we can detect the app layer protocol for the " "flow.\n", s->alproto); } if (warn_non_alproto_fp_for_alproto_sig) { fprintf(rule_engine_analysis_FD, " Warning: Rule app layer " "protocol is http, but the fast_pattern is set on the raw " "stream. Consider adding fast_pattern over a http " "buffer for increased performance."); } if (rule_warning == 0) { fprintf(rule_engine_analysis_FD, " No warnings for this rule.\n"); } fprintf(rule_engine_analysis_FD, "\n"); } return; }