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detect-engine-analyzer.c
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detect-engine-analyzer.c
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/* Copyright (C) 2007-2023 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 <emdonlo@gmail.com>
* \author Victor Julien <victor@inliniac.net>
*
* Rule analyzers for the detection engine
*/
#include "suricata-common.h"
#include "suricata.h"
#include "rust.h"
#include "action-globals.h"
#include "detect.h"
#include "detect-parse.h"
#include "detect-engine.h"
#include "detect-engine-analyzer.h"
#include "detect-engine-mpm.h"
#include "detect-engine-uint.h"
#include "conf.h"
#include "detect-content.h"
#include "detect-pcre.h"
#include "detect-bytejump.h"
#include "detect-bytetest.h"
#include "detect-flow.h"
#include "detect-tcp-flags.h"
#include "detect-tcp-ack.h"
#include "detect-ipopts.h"
#include "detect-tcp-seq.h"
#include "feature.h"
#include "util-print.h"
#include "util-time.h"
#include "util-validate.h"
#include "util-conf.h"
#include "detect-flowbits.h"
#include "util-var-name.h"
#include "detect-icmp-id.h"
static int rule_warnings_only = 0;
/* Details for each buffer being tracked */
typedef struct DetectEngineAnalyzerItems {
int16_t item_id;
bool item_seen;
bool export_item_seen;
bool check_encoding_match;
const char *item_name;
const char *display_name;
} DetectEngineAnalyzerItems;
typedef struct FpPatternStats_ {
uint16_t min;
uint16_t max;
uint32_t cnt;
uint64_t tot;
} FpPatternStats;
/* Track which items require the item_seen value to be exposed */
struct ExposedItemSeen {
const char *bufname;
bool *item_seen_ptr;
};
typedef struct EngineAnalysisCtx_ {
FILE *rule_engine_analysis_fp;
FILE *fp_engine_analysis_fp;
DetectEngineAnalyzerItems *analyzer_items;
char *file_prefix;
pcre2_code *percent_re;
/*
* This array contains the map between the `analyzer_items` array listed above and
* the item ids returned by DetectBufferTypeGetByName. Iterating signature's sigmatch
* array provides list_ids. The map converts those ids into elements of the
* analyzer items array.
*
* Ultimately, the g_buffer_type_hash is searched for each buffer name. The size of that
* hashlist is 256, so that's the value we use here.
*/
int16_t analyzer_item_map[256];
FpPatternStats fp_pattern_stats[DETECT_SM_LIST_MAX];
/*
* Certain values must be directly accessible. This array contains items that are directly
* accessed when checking if they've been seen or not.
*/
struct ExposedItemSeen exposed_item_seen_list[2];
bool analyzer_initialized;
} EngineAnalysisCtx;
const DetectEngineAnalyzerItems analyzer_items[] = {
/* request keywords */
{ 0, false, false, true, "http_uri", "http uri" },
{ 0, false, false, false, "http_raw_uri", "http raw uri" },
{ 0, false, true, false, "http_method", "http method" },
{ 0, false, false, false, "http_request_line", "http request line" },
{ 0, false, false, false, "http_client_body", "http client body" },
{ 0, false, false, true, "http_header", "http header" },
{ 0, false, false, false, "http_raw_header", "http raw header" },
{ 0, false, false, true, "http_cookie", "http cookie" },
{ 0, false, false, false, "http_user_agent", "http user agent" },
{ 0, false, false, false, "http_host", "http host" },
{ 0, false, false, false, "http_raw_host", "http raw host" },
{ 0, false, false, false, "http_accept_enc", "http accept enc" },
{ 0, false, false, false, "http_referer", "http referer" },
{ 0, false, false, false, "http_content_type", "http content type" },
{ 0, false, false, false, "http_header_names", "http header names" },
/* response keywords not listed above */
{ 0, false, false, false, "http_stat_msg", "http stat msg" },
{ 0, false, false, false, "http_stat_code", "http stat code" },
{ 0, false, true, false, "file_data", "http server body" },
/* missing request keywords */
{ 0, false, false, false, "http_request_line", "http request line" },
{ 0, false, false, false, "http_accept", "http accept" },
{ 0, false, false, false, "http_accept_lang", "http accept lang" },
{ 0, false, false, false, "http_connection", "http connection" },
{ 0, false, false, false, "http_content_len", "http content len" },
{ 0, false, false, false, "http_protocol", "http protocol" },
{ 0, false, false, false, "http_start", "http start" },
/* missing response keywords; some of the missing are listed above*/
{ 0, false, false, false, "http_response_line", "http response line" },
{ 0, false, false, false, "http.server", "http server" },
{ 0, false, false, false, "http.location", "http location" },
};
static void FpPatternStatsAdd(FpPatternStats *fp, int list, uint16_t patlen)
{
if (list < 0 || list >= DETECT_SM_LIST_MAX)
return;
FpPatternStats *f = &fp[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(const DetectEngineCtx *de_ctx, const Signature *s, char *line)
{
int fast_pattern_set = 0;
int fast_pattern_only_set = 0;
int fast_pattern_chop_set = 0;
const DetectContentData *fp_cd = NULL;
const SigMatch *mpm_sm = s->init_data->mpm_sm;
const int mpm_sm_list = s->init_data->mpm_sm_list;
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;
}
}
}
FILE *fp = de_ctx->ea->rule_engine_analysis_fp;
fprintf(fp, "== Sid: %u ==\n", s->id);
fprintf(fp, "%s\n", line);
fprintf(fp, " Fast Pattern analysis:\n");
if (s->init_data->prefilter_sm != NULL) {
fprintf(fp, " Prefilter on: %s\n",
sigmatch_table[s->init_data->prefilter_sm->type].name);
fprintf(fp, "\n");
return;
}
if (fp_cd == NULL) {
fprintf(fp, " No content present\n");
fprintf(fp, "\n");
return;
}
fprintf(fp, " Fast pattern matcher: ");
int list_type = mpm_sm_list;
if (list_type == DETECT_SM_LIST_PMATCH)
fprintf(fp, "content\n");
else {
const char *desc = DetectEngineBufferTypeGetDescriptionById(de_ctx, list_type);
const char *name = DetectEngineBufferTypeGetNameById(de_ctx, list_type);
if (desc && name) {
fprintf(fp, "%s (%s)\n", desc, name);
}
}
int flags_set = 0;
fprintf(fp, " Flags:");
if (fp_cd->flags & DETECT_CONTENT_OFFSET) {
fprintf(fp, " Offset");
flags_set = 1;
} if (fp_cd->flags & DETECT_CONTENT_DEPTH) {
fprintf(fp, " Depth");
flags_set = 1;
}
if (fp_cd->flags & DETECT_CONTENT_WITHIN) {
fprintf(fp, " Within");
flags_set = 1;
}
if (fp_cd->flags & DETECT_CONTENT_DISTANCE) {
fprintf(fp, " Distance");
flags_set = 1;
}
if (fp_cd->flags & DETECT_CONTENT_NOCASE) {
fprintf(fp, " Nocase");
flags_set = 1;
}
if (fp_cd->flags & DETECT_CONTENT_NEGATED) {
fprintf(fp, " Negated");
flags_set = 1;
}
if (flags_set == 0)
fprintf(fp, " None");
fprintf(fp, "\n");
fprintf(fp, " Fast pattern set: %s\n", fast_pattern_set ? "yes" : "no");
fprintf(fp, " Fast pattern only set: %s\n", fast_pattern_only_set ? "yes" : "no");
fprintf(fp, " Fast pattern chop set: %s\n", fast_pattern_chop_set ? "yes" : "no");
if (fast_pattern_chop_set) {
fprintf(fp, " 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)) {
FatalError("Error allocating memory");
}
memcpy(pat, fp_cd->content, fp_cd->content_len);
pat[fp_cd->content_len] = '\0';
fprintf(fp, " Original content: ");
PrintRawUriFp(fp, pat, patlen);
fprintf(fp, "\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, " Final content: ");
PrintRawUriFp(fp, pat, patlen);
fprintf(fp, "\n");
FpPatternStatsAdd(&de_ctx->ea->fp_pattern_stats[0], list_type, patlen);
} else {
fprintf(fp, " Final content: ");
PrintRawUriFp(fp, pat, patlen);
fprintf(fp, "\n");
FpPatternStatsAdd(&de_ctx->ea->fp_pattern_stats[0], list_type, patlen);
}
SCFree(pat);
fprintf(fp, "\n");
}
/**
* \brief Sets up the fast pattern analyzer according to the config.
*
* \retval 1 If rule analyzer successfully enabled.
* \retval 0 If not enabled.
*/
static int SetupFPAnalyzer(DetectEngineCtx *de_ctx)
{
int fp_engine_analysis_set = 0;
if ((ConfGetBool("engine-analysis.rules-fast-pattern",
&fp_engine_analysis_set)) == 0) {
return false;
}
if (fp_engine_analysis_set == 0)
return false;
const char *log_dir = ConfigGetLogDirectory();
char *log_path = SCMalloc(PATH_MAX);
if (log_path == NULL) {
FatalError("Unable to allocate scratch memory for rule filename");
}
snprintf(log_path, PATH_MAX, "%s/%s%s", log_dir,
de_ctx->ea->file_prefix ? de_ctx->ea->file_prefix : "", "rules_fast_pattern.txt");
FILE *fp = fopen(log_path, "w");
if (fp == NULL) {
SCLogError("failed to open %s: %s", log_path, strerror(errno));
SCFree(log_path);
return false;
}
de_ctx->ea->fp_engine_analysis_fp = fp;
SCLogInfo("Engine-Analysis for fast_pattern printed to file - %s",
log_path);
SCFree(log_path);
struct timeval tval;
gettimeofday(&tval, NULL);
struct tm local_tm;
struct tm *tms = SCLocalTime(tval.tv_sec, &local_tm);
fprintf(fp, "----------------------------------------------"
"---------------------\n");
fprintf(fp,
"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, "----------------------------------------------"
"---------------------\n");
memset(&de_ctx->ea->fp_pattern_stats[0], 0, sizeof(de_ctx->ea->fp_pattern_stats));
return true;
}
/**
* \brief Compiles regex for rule analysis
* \retval 1 if successful
* \retval 0 if on error
*/
static bool PerCentEncodingSetup(EngineAnalysisCtx *ea_ctx)
{
#define DETECT_PERCENT_ENCODING_REGEX "%[0-9|a-f|A-F]{2}"
int en;
PCRE2_SIZE eo = 0;
int opts = 0; // PCRE2_NEWLINE_ANY??
ea_ctx->percent_re = pcre2_compile((PCRE2_SPTR8)DETECT_PERCENT_ENCODING_REGEX,
PCRE2_ZERO_TERMINATED, opts, &en, &eo, NULL);
if (ea_ctx->percent_re == NULL) {
PCRE2_UCHAR errbuffer[256];
pcre2_get_error_message(en, errbuffer, sizeof(errbuffer));
SCLogError("Compile of \"%s\" failed at offset %d: %s", DETECT_PERCENT_ENCODING_REGEX,
(int)eo, errbuffer);
return false;
}
return true;
}
/**
* \brief Sets up the rule analyzer according to the config
* \retval 1 if rule analyzer successfully enabled
* \retval 0 if not enabled
*/
static int SetupRuleAnalyzer(DetectEngineCtx *de_ctx)
{
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) {
const char *log_dir;
log_dir = ConfigGetLogDirectory();
char log_path[PATH_MAX];
snprintf(log_path, sizeof(log_path), "%s/%s%s", log_dir,
de_ctx->ea->file_prefix ? de_ctx->ea->file_prefix : "", "rules_analysis.txt");
de_ctx->ea->rule_engine_analysis_fp = fopen(log_path, "w");
if (de_ctx->ea->rule_engine_analysis_fp == NULL) {
SCLogError("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;
gettimeofday(&tval, NULL);
struct tm local_tm;
struct tm *tms = SCLocalTime(tval.tv_sec, &local_tm);
fprintf(de_ctx->ea->rule_engine_analysis_fp,
"----------------------------------------------"
"---------------------\n");
fprintf(de_ctx->ea->rule_engine_analysis_fp,
"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(de_ctx->ea->rule_engine_analysis_fp,
"----------------------------------------------"
"---------------------\n");
/*compile regex's for rule analysis*/
if (!PerCentEncodingSetup(de_ctx->ea)) {
fprintf(de_ctx->ea->rule_engine_analysis_fp,
"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;
}
static void CleanupFPAnalyzer(DetectEngineCtx *de_ctx)
{
FILE *fp = de_ctx->ea->rule_engine_analysis_fp;
fprintf(fp, "============\n"
"Summary:\n============\n");
for (int i = 0; i < DETECT_SM_LIST_MAX; i++) {
FpPatternStats *f = &de_ctx->ea->fp_pattern_stats[i];
if (f->cnt == 0)
continue;
fprintf(fp,
"%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));
}
fclose(de_ctx->ea->rule_engine_analysis_fp);
de_ctx->ea->rule_engine_analysis_fp = NULL;
}
static void CleanupRuleAnalyzer(DetectEngineCtx *de_ctx)
{
if (de_ctx->ea->fp_engine_analysis_fp != NULL) {
fclose(de_ctx->ea->fp_engine_analysis_fp);
de_ctx->ea->fp_engine_analysis_fp = NULL;
}
if (de_ctx->ea->percent_re != NULL) {
pcre2_code_free(de_ctx->ea->percent_re);
}
}
void SetupEngineAnalysis(DetectEngineCtx *de_ctx, bool *fp_analysis, bool *rule_analysis)
{
*fp_analysis = false;
*rule_analysis = false;
EngineAnalysisCtx *ea = SCCalloc(1, sizeof(EngineAnalysisCtx));
if (ea == NULL) {
FatalError("Unable to allocate per-engine analysis context");
}
ea->file_prefix = NULL;
int cfg_prefix_len = strlen(de_ctx->config_prefix);
if (cfg_prefix_len > 0) {
/* length of prefix + NULL + "." */
ea->file_prefix = SCCalloc(1, cfg_prefix_len + 1 + 1);
if (ea->file_prefix == NULL) {
FatalError("Unable to allocate per-engine analysis context name buffer");
}
snprintf(ea->file_prefix, cfg_prefix_len + 1 + 1, "%s.", de_ctx->config_prefix);
}
de_ctx->ea = ea;
*fp_analysis = SetupFPAnalyzer(de_ctx);
*rule_analysis = SetupRuleAnalyzer(de_ctx);
if (!(*fp_analysis || *rule_analysis)) {
if (ea->file_prefix)
SCFree(ea->file_prefix);
if (ea->analyzer_items)
SCFree(ea->analyzer_items);
SCFree(ea);
}
}
void CleanupEngineAnalysis(DetectEngineCtx *de_ctx)
{
if (de_ctx->ea) {
CleanupRuleAnalyzer(de_ctx);
CleanupFPAnalyzer(de_ctx);
if (de_ctx->ea->file_prefix)
SCFree(de_ctx->ea->file_prefix);
if (de_ctx->ea->analyzer_items)
SCFree(de_ctx->ea->analyzer_items);
SCFree(de_ctx->ea);
de_ctx->ea = NULL;
}
}
/**
* \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
*/
static int PerCentEncodingMatch(EngineAnalysisCtx *ea_ctx, uint8_t *content, uint16_t content_len)
{
int ret = 0;
pcre2_match_data *match = pcre2_match_data_create_from_pattern(ea_ctx->percent_re, NULL);
ret = pcre2_match(ea_ctx->percent_re, (PCRE2_SPTR8)content, content_len, 0, 0, match, NULL);
if (ret == -1) {
return 0;
} else if (ret < -1) {
SCLogError("Error parsing content - %s; error code is %d", content, ret);
ret = -1;
}
pcre2_match_data_free(match);
return ret;
}
static void EngineAnalysisRulesPrintFP(const DetectEngineCtx *de_ctx, const Signature *s)
{
const DetectContentData *fp_cd = NULL;
const SigMatch *mpm_sm = s->init_data->mpm_sm;
const int mpm_sm_list = s->init_data->mpm_sm_list;
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)) {
FatalError("Error allocating memory");
}
EngineAnalysisCtx *ea_ctx = de_ctx->ea;
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(ea_ctx->rule_engine_analysis_fp, " Fast Pattern \"");
PrintRawUriFp(ea_ctx->rule_engine_analysis_fp, pat, patlen);
} else {
fprintf(ea_ctx->rule_engine_analysis_fp, " Fast Pattern \"");
PrintRawUriFp(ea_ctx->rule_engine_analysis_fp, pat, patlen);
}
SCFree(pat);
fprintf(ea_ctx->rule_engine_analysis_fp, "\" on \"");
const int list_type = mpm_sm_list;
if (list_type == DETECT_SM_LIST_PMATCH) {
int payload = 0;
int stream = 0;
if (SignatureHasPacketContent(s))
payload = 1;
if (SignatureHasStreamContent(s))
stream = 1;
fprintf(ea_ctx->rule_engine_analysis_fp, "%s",
payload ? (stream ? "payload and reassembled stream" : "payload")
: "reassembled stream");
}
else {
const char *desc = DetectEngineBufferTypeGetDescriptionById(de_ctx, list_type);
const char *name = DetectEngineBufferTypeGetNameById(de_ctx, list_type);
if (desc && name) {
fprintf(ea_ctx->rule_engine_analysis_fp, "%s (%s)", desc, name);
} else if (desc || name) {
fprintf(ea_ctx->rule_engine_analysis_fp, "%s", desc ? desc : name);
}
}
fprintf(ea_ctx->rule_engine_analysis_fp, "\" ");
const DetectBufferType *bt = DetectEngineBufferTypeGetById(de_ctx, list_type);
if (bt && bt->transforms.cnt) {
fprintf(ea_ctx->rule_engine_analysis_fp, "(with %d transform(s)) ", bt->transforms.cnt);
}
fprintf(ea_ctx->rule_engine_analysis_fp, "buffer.\n");
}
void EngineAnalysisRulesFailure(const DetectEngineCtx *de_ctx, char *line, char *file, int lineno)
{
fprintf(de_ctx->ea->fp_engine_analysis_fp, "== Sid: UNKNOWN ==\n");
fprintf(de_ctx->ea->fp_engine_analysis_fp, "%s\n", line);
fprintf(de_ctx->ea->fp_engine_analysis_fp, " FAILURE: invalid rule.\n");
fprintf(de_ctx->ea->fp_engine_analysis_fp, " File: %s.\n", file);
fprintf(de_ctx->ea->fp_engine_analysis_fp, " Line: %d.\n", lineno);
fprintf(de_ctx->ea->fp_engine_analysis_fp, "\n");
}
typedef struct RuleAnalyzer {
JsonBuilder *js; /* document root */
JsonBuilder *js_warnings;
JsonBuilder *js_notes;
} RuleAnalyzer;
static void ATTR_FMT_PRINTF(2, 3) AnalyzerNote(RuleAnalyzer *ctx, char *fmt, ...)
{
va_list ap;
char str[1024];
va_start(ap, fmt);
vsnprintf(str, sizeof(str), fmt, ap);
va_end(ap);
if (!ctx->js_notes)
ctx->js_notes = jb_new_array();
if (ctx->js_notes)
jb_append_string(ctx->js_notes, str);
}
static void ATTR_FMT_PRINTF(2, 3) AnalyzerWarning(RuleAnalyzer *ctx, char *fmt, ...)
{
va_list ap;
char str[1024];
va_start(ap, fmt);
vsnprintf(str, sizeof(str), fmt, ap);
va_end(ap);
if (!ctx->js_warnings)
ctx->js_warnings = jb_new_array();
if (ctx->js_warnings)
jb_append_string(ctx->js_warnings, str);
}
#define CHECK(pat) if (strlen((pat)) <= len && memcmp((pat), buf, MIN(len, strlen((pat)))) == 0) return true;
static bool LooksLikeHTTPMethod(const uint8_t *buf, uint16_t len)
{
CHECK("GET /");
CHECK("POST /");
CHECK("HEAD /");
CHECK("PUT /");
return false;
}
static bool LooksLikeHTTPUA(const uint8_t *buf, uint16_t len)
{
CHECK("User-Agent: ");
CHECK("\nUser-Agent: ");
return false;
}
static void DumpContent(JsonBuilder *js, const DetectContentData *cd)
{
char pattern_str[1024] = "";
DetectContentPatternPrettyPrint(cd, pattern_str, sizeof(pattern_str));
jb_set_string(js, "pattern", pattern_str);
jb_set_uint(js, "length", cd->content_len);
jb_set_bool(js, "nocase", cd->flags & DETECT_CONTENT_NOCASE);
jb_set_bool(js, "negated", cd->flags & DETECT_CONTENT_NEGATED);
jb_set_bool(js, "starts_with", cd->flags & DETECT_CONTENT_STARTS_WITH);
jb_set_bool(js, "ends_with", cd->flags & DETECT_CONTENT_ENDS_WITH);
jb_set_bool(js, "is_mpm", cd->flags & DETECT_CONTENT_MPM);
jb_set_bool(js, "no_double_inspect", cd->flags & DETECT_CONTENT_NO_DOUBLE_INSPECTION_REQUIRED);
if (cd->flags & DETECT_CONTENT_OFFSET) {
jb_set_uint(js, "offset", cd->offset);
}
if (cd->flags & DETECT_CONTENT_DEPTH) {
jb_set_uint(js, "depth", cd->depth);
}
if (cd->flags & DETECT_CONTENT_DISTANCE) {
jb_set_int(js, "distance", cd->distance);
}
if (cd->flags & DETECT_CONTENT_WITHIN) {
jb_set_int(js, "within", cd->within);
}
jb_set_bool(js, "fast_pattern", cd->flags & DETECT_CONTENT_FAST_PATTERN);
jb_set_bool(js, "relative_next", cd->flags & DETECT_CONTENT_RELATIVE_NEXT);
}
static void DumpPcre(JsonBuilder *js, const DetectPcreData *cd)
{
jb_set_bool(js, "relative", cd->flags & DETECT_PCRE_RELATIVE);
jb_set_bool(js, "relative_next", cd->flags & DETECT_PCRE_RELATIVE_NEXT);
jb_set_bool(js, "nocase", cd->flags & DETECT_PCRE_CASELESS);
jb_set_bool(js, "negated", cd->flags & DETECT_PCRE_NEGATE);
}
static void DumpMatches(RuleAnalyzer *ctx, JsonBuilder *js, const SigMatchData *smd)
{
if (smd == NULL)
return;
jb_open_array(js, "matches");
do {
jb_start_object(js);
const char *mname = sigmatch_table[smd->type].name;
jb_set_string(js, "name", mname);
switch (smd->type) {
case DETECT_CONTENT: {
const DetectContentData *cd = (const DetectContentData *)smd->ctx;
jb_open_object(js, "content");
DumpContent(js, cd);
if (cd->flags & DETECT_CONTENT_FAST_PATTERN_ONLY) {
AnalyzerNote(ctx, (char *)"'fast_pattern:only' option is silently ignored and "
"is interpreted as regular 'fast_pattern'");
}
if (LooksLikeHTTPMethod(cd->content, cd->content_len)) {
AnalyzerWarning(ctx,
(char *)"pattern looks like it inspects HTTP, use http.request_line or "
"http.method and http.uri instead for improved performance");
}
if (LooksLikeHTTPUA(cd->content, cd->content_len)) {
AnalyzerWarning(ctx,
(char *)"pattern looks like it inspects HTTP, use http.user_agent "
"or http.header for improved performance");
}
if (cd->flags & DETECT_CONTENT_WITHIN2DEPTH) {
AnalyzerNote(ctx, (char *)"'within' option for pattern w/o previous content "
"was converted to 'depth'");
}
if (cd->flags & DETECT_CONTENT_DISTANCE2OFFSET) {
AnalyzerNote(ctx, (char *)"'distance' option for pattern w/o previous content "
"was converted to 'offset'");
}
jb_close(js);
break;
}
case DETECT_PCRE: {
const DetectPcreData *cd = (const DetectPcreData *)smd->ctx;
jb_open_object(js, "pcre");
DumpPcre(js, cd);
jb_close(js);
if (cd->flags & DETECT_PCRE_RAWBYTES) {
AnalyzerNote(ctx,
(char *)"'/B' (rawbytes) option is a no-op and is silently ignored");
}
break;
}
case DETECT_BYTEJUMP: {
const DetectBytejumpData *cd = (const DetectBytejumpData *)smd->ctx;
jb_open_object(js, "byte_jump");
jb_set_uint(js, "nbytes", cd->nbytes);
jb_set_int(js, "offset", cd->offset);
jb_set_uint(js, "multiplier", cd->multiplier);
jb_set_int(js, "post_offset", cd->post_offset);
switch (cd->base) {
case DETECT_BYTEJUMP_BASE_UNSET:
jb_set_string(js, "base", "unset");
break;
case DETECT_BYTEJUMP_BASE_OCT:
jb_set_string(js, "base", "oct");
break;
case DETECT_BYTEJUMP_BASE_DEC:
jb_set_string(js, "base", "dec");
break;
case DETECT_BYTEJUMP_BASE_HEX:
jb_set_string(js, "base", "hex");
break;
}
jb_open_array(js, "flags");
if (cd->flags & DETECT_BYTEJUMP_BEGIN)
jb_append_string(js, "from_beginning");
if (cd->flags & DETECT_BYTEJUMP_LITTLE)
jb_append_string(js, "little_endian");
if (cd->flags & DETECT_BYTEJUMP_BIG)
jb_append_string(js, "big_endian");
if (cd->flags & DETECT_BYTEJUMP_STRING)
jb_append_string(js, "string");
if (cd->flags & DETECT_BYTEJUMP_RELATIVE)
jb_append_string(js, "relative");
if (cd->flags & DETECT_BYTEJUMP_ALIGN)
jb_append_string(js, "align");
if (cd->flags & DETECT_BYTEJUMP_DCE)
jb_append_string(js, "dce");
if (cd->flags & DETECT_BYTEJUMP_OFFSET_BE)
jb_append_string(js, "offset_be");
if (cd->flags & DETECT_BYTEJUMP_END)
jb_append_string(js, "from_end");
jb_close(js);
jb_close(js);
break;
}
case DETECT_BYTETEST: {
const DetectBytetestData *cd = (const DetectBytetestData *)smd->ctx;
jb_open_object(js, "byte_test");
jb_set_uint(js, "nbytes", cd->nbytes);
jb_set_int(js, "offset", cd->offset);
switch (cd->base) {
case DETECT_BYTETEST_BASE_UNSET:
jb_set_string(js, "base", "unset");
break;
case DETECT_BYTETEST_BASE_OCT:
jb_set_string(js, "base", "oct");
break;
case DETECT_BYTETEST_BASE_DEC:
jb_set_string(js, "base", "dec");
break;
case DETECT_BYTETEST_BASE_HEX:
jb_set_string(js, "base", "hex");
break;
}
jb_open_array(js, "flags");
if (cd->flags & DETECT_BYTETEST_LITTLE)
jb_append_string(js, "little_endian");
if (cd->flags & DETECT_BYTETEST_BIG)
jb_append_string(js, "big_endian");
if (cd->flags & DETECT_BYTETEST_STRING)
jb_append_string(js, "string");
if (cd->flags & DETECT_BYTETEST_RELATIVE)
jb_append_string(js, "relative");
if (cd->flags & DETECT_BYTETEST_DCE)
jb_append_string(js, "dce");
jb_close(js);
jb_close(js);
break;
}
case DETECT_IPOPTS: {
const DetectIpOptsData *cd = (const DetectIpOptsData *)smd->ctx;
jb_open_object(js, "ipopts");
const char *flag = IpOptsFlagToString(cd->ipopt);
jb_set_string(js, "option", flag);
jb_close(js);
break;
}
case DETECT_FLOWBITS: {
const DetectFlowbitsData *cd = (const DetectFlowbitsData *)smd->ctx;
jb_open_object(js, "flowbits");
switch (cd->cmd) {
case DETECT_FLOWBITS_CMD_ISSET:
jb_set_string(js, "cmd", "isset");
break;
case DETECT_FLOWBITS_CMD_ISNOTSET:
jb_set_string(js, "cmd", "isnotset");
break;
case DETECT_FLOWBITS_CMD_SET:
jb_set_string(js, "cmd", "set");
break;
case DETECT_FLOWBITS_CMD_UNSET:
jb_set_string(js, "cmd", "unset");
break;
case DETECT_FLOWBITS_CMD_TOGGLE:
jb_set_string(js, "cmd", "toggle");
break;
}
bool is_or = false;
jb_open_array(js, "names");
if (cd->or_list_size == 0) {
jb_append_string(js, VarNameStoreSetupLookup(cd->idx, VAR_TYPE_FLOW_BIT));
} else if (cd->or_list_size > 0) {
is_or = true;
for (uint8_t i = 0; i < cd->or_list_size; i++) {
const char *varname =
VarNameStoreSetupLookup(cd->or_list[i], VAR_TYPE_FLOW_BIT);
jb_append_string(js, varname);
}
}
jb_close(js); // array
if (is_or) {
jb_set_string(js, "operator", "or");
}
jb_close(js); // object
break;
}
case DETECT_ACK: {
const DetectAckData *cd = (const DetectAckData *)smd->ctx;
jb_open_object(js, "ack");
jb_set_uint(js, "number", cd->ack);
jb_close(js);
break;
}
case DETECT_SEQ: {
const DetectSeqData *cd = (const DetectSeqData *)smd->ctx;
jb_open_object(js, "seq");
jb_set_uint(js, "number", cd->seq);
jb_close(js);
break;
}
case DETECT_TCPMSS: {
const DetectU16Data *cd = (const DetectU16Data *)smd->ctx;
jb_open_object(js, "tcp_mss");
SCDetectU16ToJson(js, cd);
jb_close(js);
break;
}
case DETECT_ICMP_ID: {
const DetectIcmpIdData *cd = (const DetectIcmpIdData *)smd->ctx;
jb_open_object(js, "id");
jb_set_uint(js, "number", SCNtohs(cd->id));
jb_close(js);
break;
}
case DETECT_FLOW_AGE: {
const DetectU32Data *cd = (const DetectU32Data *)smd->ctx;
jb_open_object(js, "flow_age");
SCDetectU32ToJson(js, cd);
jb_close(js);
break;
}
}
jb_close(js);
if (smd->is_last)
break;
smd++;
} while (1);
jb_close(js);
}
SCMutex g_rules_analyzer_write_m = SCMUTEX_INITIALIZER;
void EngineAnalysisRules2(const DetectEngineCtx *de_ctx, const Signature *s)
{
SCEnter();
RuleAnalyzer ctx = { NULL, NULL, NULL };
ctx.js = jb_new_object();
if (ctx.js == NULL)
SCReturn;
jb_set_string(ctx.js, "raw", s->sig_str);
jb_set_uint(ctx.js, "id", s->id);
jb_set_uint(ctx.js, "gid", s->gid);
jb_set_uint(ctx.js, "rev", s->rev);
jb_set_string(ctx.js, "msg", s->msg);
const char *alproto = AppProtoToString(s->alproto);
jb_set_string(ctx.js, "app_proto", alproto);
jb_open_array(ctx.js, "requirements");
if (s->mask & SIG_MASK_REQUIRE_PAYLOAD) {
jb_append_string(ctx.js, "payload");
}
if (s->mask & SIG_MASK_REQUIRE_NO_PAYLOAD) {
jb_append_string(ctx.js, "no_payload");
}
if (s->mask & SIG_MASK_REQUIRE_FLOW) {
jb_append_string(ctx.js, "flow");
}
if (s->mask & SIG_MASK_REQUIRE_FLAGS_INITDEINIT) {
jb_append_string(ctx.js, "tcp_flags_init_deinit");
}
if (s->mask & SIG_MASK_REQUIRE_FLAGS_UNUSUAL) {
jb_append_string(ctx.js, "tcp_flags_unusual");
}
if (s->mask & SIG_MASK_REQUIRE_ENGINE_EVENT) {
jb_append_string(ctx.js, "engine_event");
}
if (s->mask & SIG_MASK_REQUIRE_REAL_PKT) {
jb_append_string(ctx.js, "real_pkt");
}
jb_close(ctx.js);
switch (s->type) {
case SIG_TYPE_NOT_SET:
jb_set_string(ctx.js, "type", "unset");
break;
case SIG_TYPE_IPONLY: