/**
* \brief this function is used to parse filedata options
* \brief into the current signature
*
* \param de_ctx pointer to the Detection Engine Context
* \param s pointer to the Current Signature
* \param str pointer to the user provided "filestore" option
*
* \retval 0 on Success
* \retval -1 on Failure
*/
static int DetectFiledataSetup (DetectEngineCtx *de_ctx, Signature *s, char *str)
{
SCEnter();
if (!DetectProtoContainsProto(&s->proto, IPPROTO_TCP) &&
s->alproto != ALPROTO_UNKNOWN && s->alproto != ALPROTO_HTTP &&
s->alproto != ALPROTO_SMTP) {
SCLogError(SC_ERR_CONFLICTING_RULE_KEYWORDS, "rule contains conflicting keywords.");
return -1;
}
if (s->alproto == ALPROTO_HTTP && (s->init_flags & SIG_FLAG_INIT_FLOW) &&
(s->flags & SIG_FLAG_TOSERVER) && !(s->flags & SIG_FLAG_TOCLIENT)) {
SCLogError(SC_ERR_INVALID_SIGNATURE, "Can't use file_data with flow:to_server or from_client with http.");
return -1;
}
if (s->alproto == ALPROTO_SMTP && (s->init_flags & SIG_FLAG_INIT_FLOW) &&
!(s->flags & SIG_FLAG_TOSERVER) && (s->flags & SIG_FLAG_TOCLIENT)) {
SCLogError(SC_ERR_INVALID_SIGNATURE, "Can't use file_data with flow:to_client or from_server with smtp.");
return -1;
}
s->list = DETECT_SM_LIST_FILEDATA;
return 0;
}
/**
* \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_HSBDMATCH) {
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_HSBDMATCH) {
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 & FLOW_PKT_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;
}