/* Copyright (C) 2007-2022 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 Victor Julien * * Basic detection engine */ #include "suricata-common.h" #include "suricata.h" #include "conf.h" #include "decode.h" #include "packet.h" #include "flow.h" #include "stream-tcp.h" #include "app-layer.h" #include "app-layer-parser.h" #include "app-layer-frames.h" #include "detect.h" #include "detect-dsize.h" #include "detect-engine.h" #include "detect-engine-build.h" #include "detect-engine-frame.h" #include "detect-engine-profile.h" #include "detect-engine-alert.h" #include "detect-engine-siggroup.h" #include "detect-engine-address.h" #include "detect-engine-proto.h" #include "detect-engine-port.h" #include "detect-engine-mpm.h" #include "detect-engine-iponly.h" #include "detect-engine-threshold.h" #include "detect-engine-prefilter.h" #include "detect-engine-state.h" #include "detect-engine-analyzer.h" #include "detect-engine-payload.h" #include "detect-engine-event.h" #include "detect-filestore.h" #include "detect-flowvar.h" #include "detect-replace.h" #include "util-validate.h" #include "util-detect.h" #include "util-profiling.h" #include "action-globals.h" typedef struct DetectRunScratchpad { const AppProto alproto; const uint8_t flow_flags; /* flow/state flags: STREAM_* */ const bool app_decoder_events; const SigGroupHead *sgh; SignatureMask pkt_mask; } DetectRunScratchpad; /* prototypes */ static DetectRunScratchpad DetectRunSetup(const DetectEngineCtx *de_ctx, DetectEngineThreadCtx *det_ctx, Packet * const p, Flow * const pflow); static void DetectRunInspectIPOnly(ThreadVars *tv, const DetectEngineCtx *de_ctx, DetectEngineThreadCtx *det_ctx, Flow * const pflow, Packet * const p); static inline void DetectRunGetRuleGroup(const DetectEngineCtx *de_ctx, Packet * const p, Flow * const pflow, DetectRunScratchpad *scratch); static inline void DetectRunPrefilterPkt(ThreadVars *tv, DetectEngineCtx *de_ctx, DetectEngineThreadCtx *det_ctx, Packet *p, DetectRunScratchpad *scratch); static inline void DetectRulePacketRules(ThreadVars * const tv, DetectEngineCtx * const de_ctx, DetectEngineThreadCtx * const det_ctx, Packet * const p, Flow * const pflow, const DetectRunScratchpad *scratch); static void DetectRunTx(ThreadVars *tv, DetectEngineCtx *de_ctx, DetectEngineThreadCtx *det_ctx, Packet *p, Flow *f, DetectRunScratchpad *scratch); static void DetectRunFrames(ThreadVars *tv, DetectEngineCtx *de_ctx, DetectEngineThreadCtx *det_ctx, Packet *p, Flow *f, DetectRunScratchpad *scratch); static inline void DetectRunPostRules(ThreadVars *tv, DetectEngineCtx *de_ctx, DetectEngineThreadCtx *det_ctx, Packet * const p, Flow * const pflow, DetectRunScratchpad *scratch); static void DetectRunCleanup(DetectEngineThreadCtx *det_ctx, Packet *p, Flow * const pflow); /** \internal */ static void DetectRun(ThreadVars *th_v, DetectEngineCtx *de_ctx, DetectEngineThreadCtx *det_ctx, Packet *p) { SCEnter(); SCLogDebug("p->pcap_cnt %" PRIu64 " direction %s pkt_src %s", p->pcap_cnt, p->flow ? (FlowGetPacketDirection(p->flow, p) == TOSERVER ? "toserver" : "toclient") : "noflow", PktSrcToString(p->pkt_src)); /* bail early if packet should not be inspected */ if (p->flags & PKT_NOPACKET_INSPECTION) { /* nothing to do */ SCReturn; } /* Load the Packet's flow early, even though it might not be needed. * Mark as a constant pointer, although the flow itself can change. */ Flow * const pflow = p->flow; DetectRunScratchpad scratch = DetectRunSetup(de_ctx, det_ctx, p, pflow); /* run the IPonly engine */ DetectRunInspectIPOnly(th_v, de_ctx, det_ctx, pflow, p); /* get our rule group */ DetectRunGetRuleGroup(de_ctx, p, pflow, &scratch); /* if we didn't get a sig group head, we * have nothing to do.... */ if (scratch.sgh == NULL) { SCLogDebug("no sgh for this packet, nothing to match against"); goto end; } /* run the prefilters for packets */ DetectRunPrefilterPkt(th_v, de_ctx, det_ctx, p, &scratch); PACKET_PROFILING_DETECT_START(p, PROF_DETECT_RULES); /* inspect the rules against the packet */ DetectRulePacketRules(th_v, de_ctx, det_ctx, p, pflow, &scratch); PACKET_PROFILING_DETECT_END(p, PROF_DETECT_RULES); /* run tx/state inspection. Don't call for ICMP error msgs. */ if (pflow && pflow->alstate && likely(pflow->proto == p->proto)) { if (p->proto == IPPROTO_TCP) { const TcpSession *ssn = p->flow->protoctx; if (ssn && (ssn->flags & STREAMTCP_FLAG_APP_LAYER_DISABLED) == 0) { // PACKET_PROFILING_DETECT_START(p, PROF_DETECT_TX); DetectRunFrames(th_v, de_ctx, det_ctx, p, pflow, &scratch); // PACKET_PROFILING_DETECT_END(p, PROF_DETECT_TX); } // no update to transactions if (!PKT_IS_PSEUDOPKT(p) && p->app_update_direction == 0 && ((PKT_IS_TOSERVER(p) && (p->flow->flags & FLOW_TS_APP_UPDATED) == 0) || (PKT_IS_TOCLIENT(p) && (p->flow->flags & FLOW_TC_APP_UPDATED) == 0))) { goto end; } } else if (p->proto == IPPROTO_UDP) { DetectRunFrames(th_v, de_ctx, det_ctx, p, pflow, &scratch); } PACKET_PROFILING_DETECT_START(p, PROF_DETECT_TX); DetectRunTx(th_v, de_ctx, det_ctx, p, pflow, &scratch); PACKET_PROFILING_DETECT_END(p, PROF_DETECT_TX); /* see if we need to increment the inspect_id and reset the de_state */ PACKET_PROFILING_DETECT_START(p, PROF_DETECT_TX_UPDATE); AppLayerParserSetTransactionInspectId( pflow, pflow->alparser, pflow->alstate, scratch.flow_flags, (scratch.sgh == NULL)); PACKET_PROFILING_DETECT_END(p, PROF_DETECT_TX_UPDATE); } end: DetectRunPostRules(th_v, de_ctx, det_ctx, p, pflow, &scratch); DetectRunCleanup(det_ctx, p, pflow); SCReturn; } static void DetectRunPostMatch(ThreadVars *tv, DetectEngineThreadCtx *det_ctx, Packet *p, const Signature *s) { /* run the packet match functions */ const SigMatchData *smd = s->sm_arrays[DETECT_SM_LIST_POSTMATCH]; if (smd != NULL) { KEYWORD_PROFILING_SET_LIST(det_ctx, DETECT_SM_LIST_POSTMATCH); SCLogDebug("running match functions, sm %p", smd); while (1) { KEYWORD_PROFILING_START; (void)sigmatch_table[smd->type].Match(det_ctx, p, s, smd->ctx); KEYWORD_PROFILING_END(det_ctx, smd->type, 1); if (smd->is_last) break; smd++; } } } /** * \brief Get the SigGroupHead for a packet. * * \param de_ctx detection engine context * \param p packet * * \retval sgh the SigGroupHead or NULL if non applies to the packet */ const SigGroupHead *SigMatchSignaturesGetSgh(const DetectEngineCtx *de_ctx, const Packet *p) { SCEnter(); int f; SigGroupHead *sgh = NULL; /* if the packet proto is 0 (not set), we're inspecting it against * the decoder events sgh we have. */ if (p->proto == 0 && p->events.cnt > 0) { SCReturnPtr(de_ctx->decoder_event_sgh, "SigGroupHead"); } else if (p->proto == 0) { if (!(PKT_IS_IPV4(p) || PKT_IS_IPV6(p))) { /* not IP, so nothing to do */ SCReturnPtr(NULL, "SigGroupHead"); } } /* select the flow_gh */ if (p->flowflags & FLOW_PKT_TOCLIENT) f = 0; else f = 1; int proto = IP_GET_IPPROTO(p); if (proto == IPPROTO_TCP) { DetectPort *list = de_ctx->flow_gh[f].tcp; SCLogDebug("tcp toserver %p, tcp toclient %p: going to use %p", de_ctx->flow_gh[1].tcp, de_ctx->flow_gh[0].tcp, de_ctx->flow_gh[f].tcp); uint16_t port = f ? p->dp : p->sp; SCLogDebug("tcp port %u -> %u:%u", port, p->sp, p->dp); DetectPort *sghport = DetectPortLookupGroup(list, port); if (sghport != NULL) sgh = sghport->sh; SCLogDebug("TCP list %p, port %u, direction %s, sghport %p, sgh %p", list, port, f ? "toserver" : "toclient", sghport, sgh); } else if (proto == IPPROTO_UDP) { DetectPort *list = de_ctx->flow_gh[f].udp; uint16_t port = f ? p->dp : p->sp; DetectPort *sghport = DetectPortLookupGroup(list, port); if (sghport != NULL) sgh = sghport->sh; SCLogDebug("UDP list %p, port %u, direction %s, sghport %p, sgh %p", list, port, f ? "toserver" : "toclient", sghport, sgh); } else { sgh = de_ctx->flow_gh[f].sgh[proto]; } SCReturnPtr(sgh, "SigGroupHead"); } static inline void DetectPrefilterMergeSort(DetectEngineCtx *de_ctx, DetectEngineThreadCtx *det_ctx) { SigIntId mpm, nonmpm; SigIntId *mpm_ptr = det_ctx->pmq.rule_id_array; SigIntId *nonmpm_ptr = det_ctx->non_pf_id_array; uint32_t m_cnt = det_ctx->pmq.rule_id_array_cnt; uint32_t n_cnt = det_ctx->non_pf_id_cnt; SigIntId *final_ptr; uint32_t final_cnt; SigIntId id; SigIntId previous_id = (SigIntId)-1; Signature **sig_array = de_ctx->sig_array; Signature **match_array = det_ctx->match_array; Signature *s; SCLogDebug("PMQ rule id array count %d", det_ctx->pmq.rule_id_array_cnt); /* Load first values. */ if (likely(m_cnt)) { mpm = *mpm_ptr; } else { /* mpm list is empty */ final_ptr = nonmpm_ptr; final_cnt = n_cnt; goto final; } if (likely(n_cnt)) { nonmpm = *nonmpm_ptr; } else { /* non-mpm list is empty. */ final_ptr = mpm_ptr; final_cnt = m_cnt; goto final; } while (1) { if (mpm < nonmpm) { /* Take from mpm list */ id = mpm; s = sig_array[id]; /* As the mpm list can contain duplicates, check for that here. */ if (likely(id != previous_id)) { *match_array++ = s; previous_id = id; } if (unlikely(--m_cnt == 0)) { /* mpm list is now empty */ final_ptr = nonmpm_ptr; final_cnt = n_cnt; goto final; } mpm_ptr++; mpm = *mpm_ptr; } else if (mpm > nonmpm) { id = nonmpm; s = sig_array[id]; /* As the mpm list can contain duplicates, check for that here. */ if (likely(id != previous_id)) { *match_array++ = s; previous_id = id; } if (unlikely(--n_cnt == 0)) { final_ptr = mpm_ptr; final_cnt = m_cnt; goto final; } nonmpm_ptr++; nonmpm = *nonmpm_ptr; } else { /* implied mpm == nonmpm */ /* special case: if on both lists, it's a negated mpm pattern */ /* mpm list may have dups, so skip past them here */ while (--m_cnt != 0) { mpm_ptr++; mpm = *mpm_ptr; if (mpm != nonmpm) break; } /* if mpm is done, update nonmpm_ptrs and jump to final */ if (unlikely(m_cnt == 0)) { n_cnt--; /* mpm list is now empty */ final_ptr = ++nonmpm_ptr; final_cnt = n_cnt; goto final; } /* otherwise, if nonmpm is done jump to final for mpm * mpm ptrs already updated */ if (unlikely(--n_cnt == 0)) { final_ptr = mpm_ptr; final_cnt = m_cnt; goto final; } /* not at end of the lists, update nonmpm. Mpm already * updated in while loop above. */ nonmpm_ptr++; nonmpm = *nonmpm_ptr; } } final: /* Only one list remaining. Just walk that list. */ while (final_cnt-- > 0) { id = *final_ptr++; s = sig_array[id]; /* As the mpm list can contain duplicates, check for that here. */ if (likely(id != previous_id)) { *match_array++ = s; previous_id = id; } } det_ctx->match_array_cnt = match_array - det_ctx->match_array; DEBUG_VALIDATE_BUG_ON((det_ctx->pmq.rule_id_array_cnt + det_ctx->non_pf_id_cnt) < det_ctx->match_array_cnt); PMQ_RESET(&det_ctx->pmq); } /** \internal * \brief build non-prefilter list based on the rule group list we've set. */ static inline void DetectPrefilterBuildNonPrefilterList( DetectEngineThreadCtx *det_ctx, const SignatureMask mask, const AppProto alproto) { for (uint32_t x = 0; x < det_ctx->non_pf_store_cnt; x++) { /* only if the mask matches this rule can possibly match, * so build the non_mpm array only for match candidates */ const SignatureMask rule_mask = det_ctx->non_pf_store_ptr[x].mask; const AppProto rule_alproto = det_ctx->non_pf_store_ptr[x].alproto; if ((rule_mask & mask) == rule_mask && (rule_alproto == 0 || AppProtoEquals(rule_alproto, alproto))) { det_ctx->non_pf_id_array[det_ctx->non_pf_id_cnt++] = det_ctx->non_pf_store_ptr[x].id; } } } /** \internal * \brief select non-mpm list * Based on the packet properties, select the non-mpm list to use * \todo move non_pf_store* into scratchpad */ static inline void DetectPrefilterSetNonPrefilterList(const Packet *p, DetectEngineThreadCtx *det_ctx, DetectRunScratchpad *scratch) { if ((p->proto == IPPROTO_TCP) && (p->tcph != NULL) && (p->tcph->th_flags & TH_SYN)) { det_ctx->non_pf_store_ptr = scratch->sgh->non_pf_syn_store_array; det_ctx->non_pf_store_cnt = scratch->sgh->non_pf_syn_store_cnt; } else { det_ctx->non_pf_store_ptr = scratch->sgh->non_pf_other_store_array; det_ctx->non_pf_store_cnt = scratch->sgh->non_pf_other_store_cnt; } SCLogDebug("sgh non_pf ptr %p cnt %u (syn %p/%u, other %p/%u)", det_ctx->non_pf_store_ptr, det_ctx->non_pf_store_cnt, scratch->sgh->non_pf_syn_store_array, scratch->sgh->non_pf_syn_store_cnt, scratch->sgh->non_pf_other_store_array, scratch->sgh->non_pf_other_store_cnt); } /** \internal * \brief update flow's file tracking flags based on the detection engine * A set of flags is prepared that is sent to the File API. The File API may reject one or more based on the global force settings. */ static inline void DetectPostInspectFileFlagsUpdate(Flow *f, const SigGroupHead *sgh, uint8_t direction) { uint16_t flow_file_flags = FLOWFILE_INIT; if (sgh == NULL) { SCLogDebug("requesting disabling all file features for flow"); flow_file_flags = FLOWFILE_NONE; } else { if (sgh->filestore_cnt == 0) { SCLogDebug("requesting disabling filestore for flow"); flow_file_flags |= (FLOWFILE_NO_STORE_TS|FLOWFILE_NO_STORE_TC); } #ifdef HAVE_MAGIC if (!(sgh->flags & SIG_GROUP_HEAD_HAVEFILEMAGIC)) { SCLogDebug("requesting disabling magic for flow"); flow_file_flags |= (FLOWFILE_NO_MAGIC_TS|FLOWFILE_NO_MAGIC_TC); } #endif if (!(sgh->flags & SIG_GROUP_HEAD_HAVEFILEMD5)) { SCLogDebug("requesting disabling md5 for flow"); flow_file_flags |= (FLOWFILE_NO_MD5_TS|FLOWFILE_NO_MD5_TC); } if (!(sgh->flags & SIG_GROUP_HEAD_HAVEFILESHA1)) { SCLogDebug("requesting disabling sha1 for flow"); flow_file_flags |= (FLOWFILE_NO_SHA1_TS|FLOWFILE_NO_SHA1_TC); } if (!(sgh->flags & SIG_GROUP_HEAD_HAVEFILESHA256)) { SCLogDebug("requesting disabling sha256 for flow"); flow_file_flags |= (FLOWFILE_NO_SHA256_TS|FLOWFILE_NO_SHA256_TC); } if (!(sgh->flags & SIG_GROUP_HEAD_HAVEFILESIZE)) { SCLogDebug("requesting disabling filesize for flow"); flow_file_flags |= (FLOWFILE_NO_SIZE_TS|FLOWFILE_NO_SIZE_TC); } } if (flow_file_flags != 0) { FileUpdateFlowFileFlags(f, flow_file_flags, direction); } } static inline void DetectRunPostGetFirstRuleGroup(const Packet *p, Flow *pflow, const SigGroupHead *sgh) { if ((p->flowflags & FLOW_PKT_TOSERVER) && !(pflow->flags & FLOW_SGH_TOSERVER)) { /* first time we see this toserver sgh, store it */ pflow->sgh_toserver = sgh; pflow->flags |= FLOW_SGH_TOSERVER; if (p->proto == IPPROTO_TCP && (sgh == NULL || !(sgh->flags & SIG_GROUP_HEAD_HAVERAWSTREAM))) { if (pflow->protoctx != NULL) { TcpSession *ssn = pflow->protoctx; SCLogDebug("STREAMTCP_STREAM_FLAG_DISABLE_RAW ssn.client"); ssn->client.flags |= STREAMTCP_STREAM_FLAG_DISABLE_RAW; } } DetectPostInspectFileFlagsUpdate(pflow, pflow->sgh_toserver, STREAM_TOSERVER); } else if ((p->flowflags & FLOW_PKT_TOCLIENT) && !(pflow->flags & FLOW_SGH_TOCLIENT)) { pflow->sgh_toclient = sgh; pflow->flags |= FLOW_SGH_TOCLIENT; if (p->proto == IPPROTO_TCP && (sgh == NULL || !(sgh->flags & SIG_GROUP_HEAD_HAVERAWSTREAM))) { if (pflow->protoctx != NULL) { TcpSession *ssn = pflow->protoctx; SCLogDebug("STREAMTCP_STREAM_FLAG_DISABLE_RAW ssn.server"); ssn->server.flags |= STREAMTCP_STREAM_FLAG_DISABLE_RAW; } } DetectPostInspectFileFlagsUpdate(pflow, pflow->sgh_toclient, STREAM_TOCLIENT); } } static inline void DetectRunGetRuleGroup( const DetectEngineCtx *de_ctx, Packet * const p, Flow * const pflow, DetectRunScratchpad *scratch) { const SigGroupHead *sgh = NULL; if (pflow) { bool use_flow_sgh = false; /* Get the stored sgh from the flow (if any). Make sure we're not using * the sgh for icmp error packets part of the same stream. */ if (IP_GET_IPPROTO(p) == pflow->proto) { /* filter out icmp */ PACKET_PROFILING_DETECT_START(p, PROF_DETECT_GETSGH); if ((p->flowflags & FLOW_PKT_TOSERVER) && (pflow->flags & FLOW_SGH_TOSERVER)) { sgh = pflow->sgh_toserver; SCLogDebug("sgh = pflow->sgh_toserver; => %p", sgh); use_flow_sgh = true; } else if ((p->flowflags & FLOW_PKT_TOCLIENT) && (pflow->flags & FLOW_SGH_TOCLIENT)) { sgh = pflow->sgh_toclient; SCLogDebug("sgh = pflow->sgh_toclient; => %p", sgh); use_flow_sgh = true; } PACKET_PROFILING_DETECT_END(p, PROF_DETECT_GETSGH); } if (!(use_flow_sgh)) { PACKET_PROFILING_DETECT_START(p, PROF_DETECT_GETSGH); sgh = SigMatchSignaturesGetSgh(de_ctx, p); PACKET_PROFILING_DETECT_END(p, PROF_DETECT_GETSGH); /* HACK: prevent the wrong sgh (or NULL) from being stored in the * flow's sgh pointers */ if (PKT_IS_ICMPV4(p) && ICMPV4_DEST_UNREACH_IS_VALID(p)) { ; /* no-op */ } else { /* store the found sgh (or NULL) in the flow to save us * from looking it up again for the next packet. * Also run other tasks */ DetectRunPostGetFirstRuleGroup(p, pflow, sgh); } } } else { /* p->flags & PKT_HAS_FLOW */ /* no flow */ PACKET_PROFILING_DETECT_START(p, PROF_DETECT_GETSGH); sgh = SigMatchSignaturesGetSgh(de_ctx, p); PACKET_PROFILING_DETECT_END(p, PROF_DETECT_GETSGH); } scratch->sgh = sgh; } static void DetectRunInspectIPOnly(ThreadVars *tv, const DetectEngineCtx *de_ctx, DetectEngineThreadCtx *det_ctx, Flow * const pflow, Packet * const p) { if (pflow) { /* set the iponly stuff */ if (pflow->flags & FLOW_TOCLIENT_IPONLY_SET) p->flowflags |= FLOW_PKT_TOCLIENT_IPONLY_SET; if (pflow->flags & FLOW_TOSERVER_IPONLY_SET) p->flowflags |= FLOW_PKT_TOSERVER_IPONLY_SET; if (((p->flowflags & FLOW_PKT_TOSERVER) && !(p->flowflags & FLOW_PKT_TOSERVER_IPONLY_SET)) || ((p->flowflags & FLOW_PKT_TOCLIENT) && !(p->flowflags & FLOW_PKT_TOCLIENT_IPONLY_SET))) { SCLogDebug("testing against \"ip-only\" signatures"); PACKET_PROFILING_DETECT_START(p, PROF_DETECT_IPONLY); IPOnlyMatchPacket(tv, de_ctx, det_ctx, &de_ctx->io_ctx, p); PACKET_PROFILING_DETECT_END(p, PROF_DETECT_IPONLY); /* save in the flow that we scanned this direction... */ FlowSetIPOnlyFlag(pflow, p->flowflags & FLOW_PKT_TOSERVER ? 1 : 0); } } else { /* p->flags & PKT_HAS_FLOW */ /* no flow */ /* Even without flow we should match the packet src/dst */ PACKET_PROFILING_DETECT_START(p, PROF_DETECT_IPONLY); IPOnlyMatchPacket(tv, de_ctx, det_ctx, &de_ctx->io_ctx, p); PACKET_PROFILING_DETECT_END(p, PROF_DETECT_IPONLY); } } /* returns 0 if no match, 1 if match */ static inline int DetectRunInspectRuleHeader( const Packet *p, const Flow *f, const Signature *s, const uint32_t sflags, const uint8_t s_proto_flags) { /* check if this signature has a requirement for flowvars of some type * and if so, if we actually have any in the flow. If not, the sig * can't match and we skip it. */ if ((p->flags & PKT_HAS_FLOW) && (sflags & SIG_FLAG_REQUIRE_FLOWVAR)) { DEBUG_VALIDATE_BUG_ON(f == NULL); int m = f->flowvar ? 1 : 0; /* no flowvars? skip this sig */ if (m == 0) { SCLogDebug("skipping sig as the flow has no flowvars and sig " "has SIG_FLAG_REQUIRE_FLOWVAR flag set."); return 0; } } if ((s_proto_flags & DETECT_PROTO_IPV4) && !PKT_IS_IPV4(p)) { SCLogDebug("ip version didn't match"); return 0; } if ((s_proto_flags & DETECT_PROTO_IPV6) && !PKT_IS_IPV6(p)) { SCLogDebug("ip version didn't match"); return 0; } if (DetectProtoContainsProto(&s->proto, IP_GET_IPPROTO(p)) == 0) { SCLogDebug("proto didn't match"); return 0; } /* check the source & dst port in the sig */ if (p->proto == IPPROTO_TCP || p->proto == IPPROTO_UDP || p->proto == IPPROTO_SCTP) { if (!(sflags & SIG_FLAG_DP_ANY)) { if (p->flags & PKT_IS_FRAGMENT) return 0; DetectPort *dport = DetectPortLookupGroup(s->dp,p->dp); if (dport == NULL) { SCLogDebug("dport didn't match."); return 0; } } if (!(sflags & SIG_FLAG_SP_ANY)) { if (p->flags & PKT_IS_FRAGMENT) return 0; DetectPort *sport = DetectPortLookupGroup(s->sp,p->sp); if (sport == NULL) { SCLogDebug("sport didn't match."); return 0; } } } else if ((sflags & (SIG_FLAG_DP_ANY|SIG_FLAG_SP_ANY)) != (SIG_FLAG_DP_ANY|SIG_FLAG_SP_ANY)) { SCLogDebug("port-less protocol and sig needs ports"); return 0; } /* check the destination address */ if (!(sflags & SIG_FLAG_DST_ANY)) { if (PKT_IS_IPV4(p)) { if (DetectAddressMatchIPv4(s->addr_dst_match4, s->addr_dst_match4_cnt, &p->dst) == 0) return 0; } else if (PKT_IS_IPV6(p)) { if (DetectAddressMatchIPv6(s->addr_dst_match6, s->addr_dst_match6_cnt, &p->dst) == 0) return 0; } } /* check the source address */ if (!(sflags & SIG_FLAG_SRC_ANY)) { if (PKT_IS_IPV4(p)) { if (DetectAddressMatchIPv4(s->addr_src_match4, s->addr_src_match4_cnt, &p->src) == 0) return 0; } else if (PKT_IS_IPV6(p)) { if (DetectAddressMatchIPv6(s->addr_src_match6, s->addr_src_match6_cnt, &p->src) == 0) return 0; } } return 1; } /** \internal * \brief run packet/stream prefilter engines */ static inline void DetectRunPrefilterPkt( ThreadVars *tv, DetectEngineCtx *de_ctx, DetectEngineThreadCtx *det_ctx, Packet *p, DetectRunScratchpad *scratch ) { DetectPrefilterSetNonPrefilterList(p, det_ctx, scratch); /* create our prefilter mask */ PacketCreateMask(p, &scratch->pkt_mask, scratch->alproto, scratch->app_decoder_events); /* build and prefilter non_pf list against the mask of the packet */ PACKET_PROFILING_DETECT_START(p, PROF_DETECT_NONMPMLIST); det_ctx->non_pf_id_cnt = 0; if (likely(det_ctx->non_pf_store_cnt > 0)) { DetectPrefilterBuildNonPrefilterList(det_ctx, scratch->pkt_mask, scratch->alproto); } PACKET_PROFILING_DETECT_END(p, PROF_DETECT_NONMPMLIST); /* run the prefilter engines */ Prefilter(det_ctx, scratch->sgh, p, scratch->flow_flags); /* create match list if we have non-pf and/or pf */ if (det_ctx->non_pf_store_cnt || det_ctx->pmq.rule_id_array_cnt) { #ifdef PROFILING if (tv) { StatsAddUI64(tv, det_ctx->counter_mpm_list, (uint64_t)det_ctx->pmq.rule_id_array_cnt); } #endif PACKET_PROFILING_DETECT_START(p, PROF_DETECT_PF_SORT2); DetectPrefilterMergeSort(de_ctx, det_ctx); PACKET_PROFILING_DETECT_END(p, PROF_DETECT_PF_SORT2); } #ifdef PROFILING if (tv) { StatsAddUI64(tv, det_ctx->counter_nonmpm_list, (uint64_t)det_ctx->non_pf_store_cnt); /* non mpm sigs after mask prefilter */ StatsAddUI64(tv, det_ctx->counter_fnonmpm_list, (uint64_t)det_ctx->non_pf_id_cnt); } #endif } static inline void DetectRulePacketRules( ThreadVars * const tv, DetectEngineCtx * const de_ctx, DetectEngineThreadCtx * const det_ctx, Packet * const p, Flow * const pflow, const DetectRunScratchpad *scratch ) { const Signature *s = NULL; const Signature *next_s = NULL; /* inspect the sigs against the packet */ /* Prefetch the next signature. */ SigIntId match_cnt = det_ctx->match_array_cnt; #ifdef PROFILING if (tv) { StatsAddUI64(tv, det_ctx->counter_match_list, (uint64_t)match_cnt); } #endif Signature **match_array = det_ctx->match_array; SGH_PROFILING_RECORD(det_ctx, scratch->sgh); #ifdef PROFILING if (match_cnt >= de_ctx->profile_match_logging_threshold) RulesDumpMatchArray(det_ctx, scratch->sgh, p); #endif uint32_t sflags, next_sflags = 0; if (match_cnt) { next_s = *match_array++; next_sflags = next_s->flags; } while (match_cnt--) { RULE_PROFILING_START(p); uint8_t alert_flags = 0; #ifdef PROFILE_RULES bool smatch = false; /* signature match */ #endif s = next_s; sflags = next_sflags; if (match_cnt) { next_s = *match_array++; next_sflags = next_s->flags; } const uint8_t s_proto_flags = s->proto.flags; SCLogDebug("inspecting signature id %"PRIu32"", s->id); if (s->app_inspect != NULL) { goto next; // handle sig in DetectRunTx } if (s->frame_inspect != NULL) { goto next; // handle sig in DetectRunFrame } /* don't run mask check for stateful rules. * There we depend on prefilter */ if ((s->mask & scratch->pkt_mask) != s->mask) { SCLogDebug("mask mismatch %x & %x != %x", s->mask, scratch->pkt_mask, s->mask); goto next; } if (SigDsizePrefilter(p, s, sflags)) goto next; /* if the sig has alproto and the session as well they should match */ if (likely(sflags & SIG_FLAG_APPLAYER)) { if (s->alproto != ALPROTO_UNKNOWN && !AppProtoEquals(s->alproto, scratch->alproto)) { SCLogDebug("alproto mismatch"); goto next; } } if (DetectRunInspectRuleHeader(p, pflow, s, sflags, s_proto_flags) == 0) { goto next; } if (DetectEnginePktInspectionRun(tv, det_ctx, s, pflow, p, &alert_flags) == false) { goto next; } #ifdef PROFILE_RULES smatch = true; #endif DetectRunPostMatch(tv, det_ctx, p, s); AlertQueueAppend(det_ctx, s, p, 0, alert_flags); next: DetectVarProcessList(det_ctx, pflow, p); DetectReplaceFree(det_ctx); RULE_PROFILING_END(det_ctx, s, smatch, p); det_ctx->flags = 0; continue; } } static DetectRunScratchpad DetectRunSetup( const DetectEngineCtx *de_ctx, DetectEngineThreadCtx *det_ctx, Packet * const p, Flow * const pflow) { AppProto alproto = ALPROTO_UNKNOWN; uint8_t flow_flags = 0; /* flow/state flags */ bool app_decoder_events = false; PACKET_PROFILING_DETECT_START(p, PROF_DETECT_SETUP); #ifdef UNITTESTS p->alerts.cnt = 0; p->alerts.discarded = 0; p->alerts.suppressed = 0; #endif det_ctx->filestore_cnt = 0; det_ctx->base64_decoded_len = 0; det_ctx->raw_stream_progress = 0; det_ctx->match_array_cnt = 0; det_ctx->alert_queue_size = 0; p->alerts.drop.action = 0; #ifdef DEBUG if (p->flags & PKT_STREAM_ADD) { det_ctx->pkt_stream_add_cnt++; } #endif /* grab the protocol state we will detect on */ if (p->flags & PKT_HAS_FLOW) { DEBUG_VALIDATE_BUG_ON(pflow == NULL); if (p->flowflags & FLOW_PKT_TOSERVER) { flow_flags = STREAM_TOSERVER; SCLogDebug("flag STREAM_TOSERVER set"); } else if (p->flowflags & FLOW_PKT_TOCLIENT) { flow_flags = STREAM_TOCLIENT; SCLogDebug("flag STREAM_TOCLIENT set"); } SCLogDebug("p->flowflags 0x%02x", p->flowflags); if (p->flags & PKT_STREAM_EOF) { flow_flags |= STREAM_EOF; SCLogDebug("STREAM_EOF set"); } /* store tenant_id in the flow so that we can use it * for creating pseudo packets */ if (p->tenant_id > 0 && pflow->tenant_id == 0) { pflow->tenant_id = p->tenant_id; } /* live ruleswap check for flow updates */ if (pflow->de_ctx_version == 0) { /* first time this flow is inspected, set id */ pflow->de_ctx_version = de_ctx->version; } else if (pflow->de_ctx_version != de_ctx->version) { /* first time we inspect flow with this de_ctx, reset */ pflow->flags &= ~FLOW_SGH_TOSERVER; pflow->flags &= ~FLOW_SGH_TOCLIENT; pflow->sgh_toserver = NULL; pflow->sgh_toclient = NULL; pflow->de_ctx_version = de_ctx->version; GenericVarFree(pflow->flowvar); pflow->flowvar = NULL; DetectEngineStateResetTxs(pflow); } /* Retrieve the app layer state and protocol and the tcp reassembled * stream chunks. */ if ((p->proto == IPPROTO_TCP && (p->flags & PKT_STREAM_EST)) || (p->proto == IPPROTO_UDP) || (p->proto == IPPROTO_SCTP && (p->flowflags & FLOW_PKT_ESTABLISHED))) { /* update flow flags with knowledge on disruptions */ flow_flags = FlowGetDisruptionFlags(pflow, flow_flags); alproto = FlowGetAppProtocol(pflow); if (p->proto == IPPROTO_TCP && pflow->protoctx && StreamReassembleRawHasDataReady(pflow->protoctx, p)) { p->flags |= PKT_DETECT_HAS_STREAMDATA; } SCLogDebug("alproto %u", alproto); } else { SCLogDebug("packet doesn't have established flag set (proto %d)", p->proto); } app_decoder_events = AppLayerParserHasDecoderEvents(pflow->alparser); } DetectRunScratchpad pad = { alproto, flow_flags, app_decoder_events, NULL, 0 }; PACKET_PROFILING_DETECT_END(p, PROF_DETECT_SETUP); return pad; } static inline void DetectRunPostRules( ThreadVars *tv, DetectEngineCtx *de_ctx, DetectEngineThreadCtx *det_ctx, Packet * const p, Flow * const pflow, DetectRunScratchpad *scratch) { /* so now let's iterate the alerts and remove the ones after a pass rule * matched (if any). This is done inside PacketAlertFinalize() */ /* PR: installed "tag" keywords are handled after the threshold inspection */ PACKET_PROFILING_DETECT_START(p, PROF_DETECT_ALERT); PacketAlertFinalize(de_ctx, det_ctx, p); if (p->alerts.cnt > 0) { StatsAddUI64(tv, det_ctx->counter_alerts, (uint64_t)p->alerts.cnt); } if (p->alerts.discarded > 0) { StatsAddUI64(tv, det_ctx->counter_alerts_overflow, (uint64_t)p->alerts.discarded); } if (p->alerts.suppressed > 0) { StatsAddUI64(tv, det_ctx->counter_alerts_suppressed, (uint64_t)p->alerts.suppressed); } PACKET_PROFILING_DETECT_END(p, PROF_DETECT_ALERT); } static void DetectRunCleanup(DetectEngineThreadCtx *det_ctx, Packet *p, Flow * const pflow) { PACKET_PROFILING_DETECT_START(p, PROF_DETECT_CLEANUP); InspectionBufferClean(det_ctx); if (pflow != NULL) { /* update inspected tracker for raw reassembly */ if (p->proto == IPPROTO_TCP && pflow->protoctx != NULL && (p->flags & PKT_DETECT_HAS_STREAMDATA)) { StreamReassembleRawUpdateProgress(pflow->protoctx, p, det_ctx->raw_stream_progress); } } PACKET_PROFILING_DETECT_END(p, PROF_DETECT_CLEANUP); SCReturn; } void RuleMatchCandidateTxArrayInit(DetectEngineThreadCtx *det_ctx, uint32_t size) { DEBUG_VALIDATE_BUG_ON(det_ctx->tx_candidates); det_ctx->tx_candidates = SCCalloc(size, sizeof(RuleMatchCandidateTx)); if (det_ctx->tx_candidates == NULL) { FatalError("failed to allocate %" PRIu64 " bytes", (uint64_t)(size * sizeof(RuleMatchCandidateTx))); } det_ctx->tx_candidates_size = size; SCLogDebug("array initialized to %u elements (%"PRIu64" bytes)", size, (uint64_t)(size * sizeof(RuleMatchCandidateTx))); } void RuleMatchCandidateTxArrayFree(DetectEngineThreadCtx *det_ctx) { SCFree(det_ctx->tx_candidates); det_ctx->tx_candidates_size = 0; } /* if size >= cur_space */ static inline bool RuleMatchCandidateTxArrayHasSpace(const DetectEngineThreadCtx *det_ctx, const uint32_t need) { if (det_ctx->tx_candidates_size >= need) return 1; return 0; } /* realloc */ static int RuleMatchCandidateTxArrayExpand(DetectEngineThreadCtx *det_ctx, const uint32_t needed) { const uint32_t old_size = det_ctx->tx_candidates_size; uint32_t new_size = needed; void *ptmp = SCRealloc(det_ctx->tx_candidates, (new_size * sizeof(RuleMatchCandidateTx))); if (ptmp == NULL) { FatalError("failed to expand to %" PRIu64 " bytes", (uint64_t)(new_size * sizeof(RuleMatchCandidateTx))); // TODO can this be handled more gracefully? } det_ctx->tx_candidates = ptmp; det_ctx->tx_candidates_size = new_size; SCLogDebug("array expanded from %u to %u elements (%"PRIu64" bytes -> %"PRIu64" bytes)", old_size, new_size, (uint64_t)(old_size * sizeof(RuleMatchCandidateTx)), (uint64_t)(new_size * sizeof(RuleMatchCandidateTx))); (void)old_size; return 1; } /** \internal * \brief sort helper for sorting match candidates by id: ascending * * The id field is set from Signature::num, so we sort the candidates to match the signature * sort order (ascending), where candidates that have flags go first. */ static int DetectRunTxSortHelper(const void *a, const void *b) { const RuleMatchCandidateTx *s0 = a; const RuleMatchCandidateTx *s1 = b; if (s1->id == s0->id) { if (s1->flags && !s0->flags) return 1; else if (!s1->flags && s0->flags) return -1; return 0; } else return s0->id > s1->id ? 1 : -1; } #if 0 #define TRACE_SID_TXS(sid,txs,...) \ do { \ char _trace_buf[2048]; \ snprintf(_trace_buf, sizeof(_trace_buf), __VA_ARGS__); \ SCLogNotice("%p/%"PRIu64"/%u: %s", txs->tx_ptr, txs->tx_id, sid, _trace_buf); \ } while(0) #else #define TRACE_SID_TXS(sid,txs,...) #endif /** \internal * \brief inspect a rule against a transaction * * Inspect a rule. New detection or continued stateful * detection. * * \param stored_flags pointer to stored flags or NULL. * If stored_flags is set it means we're continuing * inspection from an earlier run. * * \retval bool true sig matched, false didn't match */ static bool DetectRunTxInspectRule(ThreadVars *tv, DetectEngineCtx *de_ctx, DetectEngineThreadCtx *det_ctx, Packet *p, Flow *f, const uint8_t in_flow_flags, // direction, EOF, etc void *alstate, DetectTransaction *tx, const Signature *s, uint32_t *stored_flags, RuleMatchCandidateTx *can, DetectRunScratchpad *scratch) { uint8_t flow_flags = in_flow_flags; const int direction = (flow_flags & STREAM_TOSERVER) ? 0 : 1; uint32_t inspect_flags = stored_flags ? *stored_flags : 0; int total_matches = 0; uint16_t file_no_match = 0; bool retval = false; bool mpm_before_progress = false; // is mpm engine before progress? bool mpm_in_progress = false; // is mpm engine in a buffer we will revisit? TRACE_SID_TXS(s->id, tx, "starting %s", direction ? "toclient" : "toserver"); /* for a new inspection we inspect pkt header and packet matches */ if (likely(stored_flags == NULL)) { TRACE_SID_TXS(s->id, tx, "first inspect, run packet matches"); if (DetectRunInspectRuleHeader(p, f, s, s->flags, s->proto.flags) == 0) { TRACE_SID_TXS(s->id, tx, "DetectRunInspectRuleHeader() no match"); return false; } if (DetectEnginePktInspectionRun(tv, det_ctx, s, f, p, NULL) == false) { TRACE_SID_TXS(s->id, tx, "DetectEnginePktInspectionRun no match"); return false; } /* stream mpm and negated mpm sigs can end up here with wrong proto */ if (!(AppProtoEquals(s->alproto, f->alproto) || s->alproto == ALPROTO_UNKNOWN)) { TRACE_SID_TXS(s->id, tx, "alproto mismatch"); return false; } } const DetectEngineAppInspectionEngine *engine = s->app_inspect; while (engine != NULL) { // TODO could be do {} while as s->app_inspect cannot be null TRACE_SID_TXS(s->id, tx, "engine %p inspect_flags %x", engine, inspect_flags); if (!(inspect_flags & BIT_U32(engine->id)) && direction == engine->dir) { const bool skip_engine = (engine->alproto != 0 && engine->alproto != f->alproto); /* special case: file_data on 'alert tcp' will have engines * in the list that are not for us. */ if (unlikely(skip_engine)) { engine = engine->next; continue; } /* engines are sorted per progress, except that the one with * mpm/prefilter enabled is first */ if (tx->tx_progress < engine->progress) { SCLogDebug("tx progress %d < engine progress %d", tx->tx_progress, engine->progress); break; } if (engine->mpm) { if (tx->tx_progress > engine->progress) { TRACE_SID_TXS(s->id, tx, "engine->mpm: t->tx_progress %u > engine->progress %u, so set " "mpm_before_progress", tx->tx_progress, engine->progress); mpm_before_progress = true; } else if (tx->tx_progress == engine->progress) { TRACE_SID_TXS(s->id, tx, "engine->mpm: t->tx_progress %u == engine->progress %u, so set " "mpm_in_progress", tx->tx_progress, engine->progress); mpm_in_progress = true; } } /* run callback: but bypass stream callback if we can */ uint8_t match; if (unlikely(engine->stream && can->stream_stored)) { match = can->stream_result; TRACE_SID_TXS(s->id, tx, "stream skipped, stored result %d used instead", match); } else { KEYWORD_PROFILING_SET_LIST(det_ctx, engine->sm_list); DEBUG_VALIDATE_BUG_ON(engine->v2.Callback == NULL); match = engine->v2.Callback( de_ctx, det_ctx, engine, s, f, flow_flags, alstate, tx->tx_ptr, tx->tx_id); TRACE_SID_TXS(s->id, tx, "engine %p match %d", engine, match); if (engine->stream) { can->stream_stored = true; can->stream_result = match; TRACE_SID_TXS(s->id, tx, "stream ran, store result %d for next tx (if any)", match); } } if (match == DETECT_ENGINE_INSPECT_SIG_MATCH) { inspect_flags |= BIT_U32(engine->id); engine = engine->next; total_matches++; continue; } else if (match == DETECT_ENGINE_INSPECT_SIG_MATCH_MORE_FILES) { /* if the file engine matched, but indicated more * files are still in progress, we don't set inspect * flags as these would end inspection for this tx */ engine = engine->next; total_matches++; continue; } else if (match == DETECT_ENGINE_INSPECT_SIG_CANT_MATCH) { inspect_flags |= DE_STATE_FLAG_SIG_CANT_MATCH; inspect_flags |= BIT_U32(engine->id); } else if (match == DETECT_ENGINE_INSPECT_SIG_CANT_MATCH_FILES) { inspect_flags |= DE_STATE_FLAG_SIG_CANT_MATCH; inspect_flags |= BIT_U32(engine->id); file_no_match = 1; } /* implied DETECT_ENGINE_INSPECT_SIG_NO_MATCH */ if (engine->mpm && mpm_before_progress) { inspect_flags |= DE_STATE_FLAG_SIG_CANT_MATCH; inspect_flags |= BIT_U32(engine->id); } break; } engine = engine->next; } TRACE_SID_TXS(s->id, tx, "inspect_flags %x, total_matches %u, engine %p", inspect_flags, total_matches, engine); if (engine == NULL && total_matches) { inspect_flags |= DE_STATE_FLAG_FULL_INSPECT; TRACE_SID_TXS(s->id, tx, "MATCH"); retval = true; } if (stored_flags) { *stored_flags = inspect_flags; TRACE_SID_TXS(s->id, tx, "continue inspect flags %08x", inspect_flags); } else { // store... or? If tx is done we might not want to come back to this tx // also... if mpmid tracking is enabled, we won't do a sig again for this tx... TRACE_SID_TXS(s->id, tx, "start inspect flags %08x", inspect_flags); if (inspect_flags & DE_STATE_FLAG_SIG_CANT_MATCH) { if (file_no_match) { /* if we have a mismatch on a file sig, we need to keep state. * We may get another file on the same tx (for http and smtp * at least), so for a new file we need to re-eval the sig. * Thoughts / TODO: * - not for some protos that have 1 file per tx (e.g. nfs) * - maybe we only need this for file sigs that mix with * other matches? E.g. 'POST + filename', is different than * just 'filename'. */ DetectRunStoreStateTx(scratch->sgh, f, tx->tx_ptr, tx->tx_id, s, inspect_flags, flow_flags, file_no_match); } } else if ((inspect_flags & DE_STATE_FLAG_FULL_INSPECT) && mpm_before_progress) { TRACE_SID_TXS(s->id, tx, "no need to store match sig, " "mpm won't trigger for it anymore"); if (inspect_flags & DE_STATE_FLAG_FILE_INSPECT) { TRACE_SID_TXS(s->id, tx, "except that for new files, " "we may have to revisit anyway"); DetectRunStoreStateTx(scratch->sgh, f, tx->tx_ptr, tx->tx_id, s, inspect_flags, flow_flags, file_no_match); } } else if ((inspect_flags & DE_STATE_FLAG_FULL_INSPECT) == 0 && mpm_in_progress) { TRACE_SID_TXS(s->id, tx, "no need to store no-match sig, " "mpm will revisit it"); } else { TRACE_SID_TXS(s->id, tx, "storing state: flags %08x", inspect_flags); DetectRunStoreStateTx(scratch->sgh, f, tx->tx_ptr, tx->tx_id, s, inspect_flags, flow_flags, file_no_match); } } return retval; } #define NO_TX \ { \ NULL, 0, NULL, NULL, 0, 0, 0, 0, 0, \ } /** \internal * \brief get a DetectTransaction object * \retval struct filled with relevant info or all nulls/0s */ static DetectTransaction GetDetectTx(const uint8_t ipproto, const AppProto alproto, void *alstate, const uint64_t tx_id, void *tx_ptr, const int tx_end_state, const uint8_t flow_flags) { AppLayerTxData *txd = AppLayerParserGetTxData(ipproto, alproto, tx_ptr); if (unlikely(txd == NULL)) { DetectTransaction no_tx = NO_TX; return no_tx; } uint64_t detect_flags = (flow_flags & STREAM_TOSERVER) ? txd->detect_flags_ts : txd->detect_flags_tc; if (detect_flags & APP_LAYER_TX_INSPECTED_FLAG) { SCLogDebug("%"PRIu64" tx already fully inspected for %s. Flags %016"PRIx64, tx_id, flow_flags & STREAM_TOSERVER ? "toserver" : "toclient", detect_flags); DetectTransaction no_tx = NO_TX; return no_tx; } if (detect_flags & APP_LAYER_TX_SKIP_INSPECT_FLAG) { SCLogDebug("%" PRIu64 " tx should not be inspected in direction %s. Flags %016" PRIx64, tx_id, flow_flags & STREAM_TOSERVER ? "toserver" : "toclient", detect_flags); DetectTransaction no_tx = NO_TX; return no_tx; } const int tx_progress = AppLayerParserGetStateProgress(ipproto, alproto, tx_ptr, flow_flags); const int dir_int = (flow_flags & STREAM_TOSERVER) ? 0 : 1; DetectEngineState *tx_de_state = txd->de_state; DetectEngineStateDirection *tx_dir_state = tx_de_state ? &tx_de_state->dir_state[dir_int] : NULL; uint64_t prefilter_flags = detect_flags & APP_LAYER_TX_PREFILTER_MASK; DEBUG_VALIDATE_BUG_ON(prefilter_flags & APP_LAYER_TX_RESERVED_FLAGS); DetectTransaction tx = { .tx_ptr = tx_ptr, .tx_id = tx_id, .tx_data_ptr = (struct AppLayerTxData *)txd, .de_state = tx_dir_state, .detect_flags = detect_flags, .prefilter_flags = prefilter_flags, .prefilter_flags_orig = prefilter_flags, .tx_progress = tx_progress, .tx_end_state = tx_end_state, }; return tx; } static inline void StoreDetectFlags(DetectTransaction *tx, const uint8_t flow_flags, const uint8_t ipproto, const AppProto alproto, const uint64_t detect_flags) { AppLayerTxData *txd = (AppLayerTxData *)tx->tx_data_ptr; if (likely(txd != NULL)) { if (flow_flags & STREAM_TOSERVER) { txd->detect_flags_ts = detect_flags; } else { txd->detect_flags_tc = detect_flags; } } } // Merge 'state' rules from the regular prefilter // updates array_idx on the way static inline void RuleMatchCandidateMergeStateRules( DetectEngineThreadCtx *det_ctx, uint32_t *array_idx) { // Now, we will merge 2 sorted lists : // the one in det_ctx->tx_candidates // and the one in det_ctx->match_array // For match_array, we take only the relevant elements where s->app_inspect != NULL // Basically, we iterate at the same time over the 2 lists // comparing and taking an element from either. // Trick is to do so in place in det_ctx->tx_candidates, // so as to minimize the number of moves in det_ctx->tx_candidates. // For this, the algorithm traverses the lists in reverse order. // Otherwise, if the first element of match_array was to be put before // all tx_candidates, we would need to shift all tx_candidates // Retain the number of elements sorted in tx_candidates before merge uint32_t j = *array_idx; // First loop only counting the number of elements to add for (uint32_t i = 0; i < det_ctx->match_array_cnt; i++) { const Signature *s = det_ctx->match_array[i]; if (s->app_inspect != NULL) { (*array_idx)++; } } // Future number of elements in tx_candidates after merge uint32_t k = *array_idx; if (k == j) { // no new element from match_array to merge in tx_candidates return; } // variable i is for all elements of match_array (even not relevant ones) // variable j is for elements of tx_candidates before merge // variable k is for elements of tx_candidates after merge for (uint32_t i = det_ctx->match_array_cnt; i > 0;) { const Signature *s = det_ctx->match_array[i - 1]; if (s->app_inspect == NULL) { // no relevant element, get the next one from match_array i--; continue; } // we have one element from match_array to merge in tx_candidates k--; if (j > 0) { // j > 0 means there is still at least one element in tx_candidates to merge const RuleMatchCandidateTx *s0 = &det_ctx->tx_candidates[j - 1]; if (s->num <= s0->id) { // get next element from previous tx_candidates j--; // take the element from tx_candidates before merge det_ctx->tx_candidates[k].s = det_ctx->tx_candidates[j].s; det_ctx->tx_candidates[k].id = det_ctx->tx_candidates[j].id; det_ctx->tx_candidates[k].flags = det_ctx->tx_candidates[j].flags; det_ctx->tx_candidates[k].stream_reset = det_ctx->tx_candidates[j].stream_reset; continue; } } // otherwise // get next element from match_array i--; // take the element from match_array det_ctx->tx_candidates[k].s = s; det_ctx->tx_candidates[k].id = s->num; det_ctx->tx_candidates[k].flags = NULL; det_ctx->tx_candidates[k].stream_reset = 0; } // Even if k > 0 or j > 0, the loop is over. (Note that j == k now) // The remaining elements in tx_candidates up to k were already sorted // and come before any other element later in the list } static void DetectRunTx(ThreadVars *tv, DetectEngineCtx *de_ctx, DetectEngineThreadCtx *det_ctx, Packet *p, Flow *f, DetectRunScratchpad *scratch) { const uint8_t flow_flags = scratch->flow_flags; const SigGroupHead * const sgh = scratch->sgh; void * const alstate = f->alstate; const uint8_t ipproto = f->proto; const AppProto alproto = f->alproto; const uint64_t total_txs = AppLayerParserGetTxCnt(f, alstate); uint64_t tx_id_min = AppLayerParserGetTransactionInspectId(f->alparser, flow_flags); const int tx_end_state = AppLayerParserGetStateProgressCompletionStatus(alproto, flow_flags); AppLayerGetTxIteratorFunc IterFunc = AppLayerGetTxIterator(ipproto, alproto); AppLayerGetTxIterState state; memset(&state, 0, sizeof(state)); while (1) { AppLayerGetTxIterTuple ires = IterFunc(ipproto, alproto, alstate, tx_id_min, total_txs, &state); if (ires.tx_ptr == NULL) break; DetectTransaction tx = GetDetectTx(ipproto, alproto, alstate, ires.tx_id, ires.tx_ptr, tx_end_state, flow_flags); if (tx.tx_ptr == NULL) { SCLogDebug("%p/%"PRIu64" no transaction to inspect", tx.tx_ptr, tx_id_min); tx_id_min++; // next (if any) run look for +1 goto next; } tx_id_min = tx.tx_id + 1; // next look for cur + 1 bool do_sort = false; // do we need to sort the tx candidate list? uint32_t array_idx = 0; uint32_t total_rules = det_ctx->match_array_cnt; total_rules += (tx.de_state ? tx.de_state->cnt : 0); /* run prefilter engines and merge results into a candidates array */ if (sgh->tx_engines) { PACKET_PROFILING_DETECT_START(p, PROF_DETECT_PF_TX); DetectRunPrefilterTx(det_ctx, sgh, p, ipproto, flow_flags, alproto, alstate, &tx); PACKET_PROFILING_DETECT_END(p, PROF_DETECT_PF_TX); SCLogDebug("%p/%"PRIu64" rules added from prefilter: %u candidates", tx.tx_ptr, tx.tx_id, det_ctx->pmq.rule_id_array_cnt); total_rules += det_ctx->pmq.rule_id_array_cnt; if (!(RuleMatchCandidateTxArrayHasSpace(det_ctx, total_rules))) { RuleMatchCandidateTxArrayExpand(det_ctx, total_rules); } for (uint32_t i = 0; i < det_ctx->pmq.rule_id_array_cnt; i++) { const Signature *s = de_ctx->sig_array[det_ctx->pmq.rule_id_array[i]]; const SigIntId id = s->num; det_ctx->tx_candidates[array_idx].s = s; det_ctx->tx_candidates[array_idx].id = id; det_ctx->tx_candidates[array_idx].flags = NULL; det_ctx->tx_candidates[array_idx].stream_reset = 0; array_idx++; } PMQ_RESET(&det_ctx->pmq); } else { if (!(RuleMatchCandidateTxArrayHasSpace(det_ctx, total_rules))) { RuleMatchCandidateTxArrayExpand(det_ctx, total_rules); } } /* merge 'state' rules from the regular prefilter */ #ifdef PROFILING uint32_t x = array_idx; #endif RuleMatchCandidateMergeStateRules(det_ctx, &array_idx); /* merge stored state into results */ if (tx.de_state != NULL) { const uint32_t old = array_idx; /* if tx.de_state->flags has 'new file' set and sig below has * 'file inspected' flag, reset the file part of the state */ const bool have_new_file = (tx.de_state->flags & DETECT_ENGINE_STATE_FLAG_FILE_NEW); if (have_new_file) { SCLogDebug("%p/%"PRIu64" destate: need to consider new file", tx.tx_ptr, tx.tx_id); tx.de_state->flags &= ~DETECT_ENGINE_STATE_FLAG_FILE_NEW; } SigIntId state_cnt = 0; DeStateStore *tx_store = tx.de_state->head; for (; tx_store != NULL; tx_store = tx_store->next) { SCLogDebug("tx_store %p", tx_store); SigIntId store_cnt = 0; for (store_cnt = 0; store_cnt < DE_STATE_CHUNK_SIZE && state_cnt < tx.de_state->cnt; store_cnt++, state_cnt++) { DeStateStoreItem *item = &tx_store->store[store_cnt]; SCLogDebug("rule id %u, inspect_flags %u", item->sid, item->flags); if (have_new_file && (item->flags & DE_STATE_FLAG_FILE_INSPECT)) { /* remove part of the state. File inspect engine will now * be able to run again */ item->flags &= ~(DE_STATE_FLAG_SIG_CANT_MATCH|DE_STATE_FLAG_FULL_INSPECT|DE_STATE_FLAG_FILE_INSPECT); SCLogDebug("rule id %u, post file reset inspect_flags %u", item->sid, item->flags); } det_ctx->tx_candidates[array_idx].s = de_ctx->sig_array[item->sid]; det_ctx->tx_candidates[array_idx].id = item->sid; det_ctx->tx_candidates[array_idx].flags = &item->flags; det_ctx->tx_candidates[array_idx].stream_reset = 0; array_idx++; } } do_sort |= (old && old != array_idx); // sort if continue list adds sids SCLogDebug("%p/%" PRIu64 " rules added from 'continue' list: %u", tx.tx_ptr, tx.tx_id, array_idx - old); } if (do_sort) { qsort(det_ctx->tx_candidates, array_idx, sizeof(RuleMatchCandidateTx), DetectRunTxSortHelper); } #ifdef PROFILING if (array_idx >= de_ctx->profile_match_logging_threshold) RulesDumpTxMatchArray(det_ctx, scratch->sgh, p, tx.tx_id, array_idx, x); #endif det_ctx->tx_id = tx.tx_id; det_ctx->tx_id_set = true; det_ctx->p = p; #ifdef DEBUG for (uint32_t i = 0; i < array_idx; i++) { RuleMatchCandidateTx *can = &det_ctx->tx_candidates[i]; const Signature *s = det_ctx->tx_candidates[i].s; SCLogDebug("%u: sid %u flags %p", i, s->id, can->flags); } #endif /* run rules: inspect the match candidates */ for (uint32_t i = 0; i < array_idx; i++) { RuleMatchCandidateTx *can = &det_ctx->tx_candidates[i]; const Signature *s = det_ctx->tx_candidates[i].s; uint32_t *inspect_flags = det_ctx->tx_candidates[i].flags; /* deduplicate: rules_array is sorted, but not deduplicated: * both mpm and stored state could give us the same sid. * As they are back to back in that case we can check for it * here. We select the stored state one as that comes first * in the array. */ while ((i + 1) < array_idx && det_ctx->tx_candidates[i].s == det_ctx->tx_candidates[i + 1].s) { SCLogDebug("%p/%" PRIu64 " inspecting SKIP NEXT: sid %u (%u), flags %08x", tx.tx_ptr, tx.tx_id, s->id, s->num, inspect_flags ? *inspect_flags : 0); i++; } SCLogDebug("%p/%"PRIu64" inspecting: sid %u (%u), flags %08x", tx.tx_ptr, tx.tx_id, s->id, s->num, inspect_flags ? *inspect_flags : 0); if (inspect_flags) { if (*inspect_flags & (DE_STATE_FLAG_FULL_INSPECT|DE_STATE_FLAG_SIG_CANT_MATCH)) { SCLogDebug("%p/%"PRIu64" inspecting: sid %u (%u), flags %08x ALREADY COMPLETE", tx.tx_ptr, tx.tx_id, s->id, s->num, *inspect_flags); continue; } } if (inspect_flags) { /* continue previous inspection */ SCLogDebug("%p/%" PRIu64 " Continuing sid %u", tx.tx_ptr, tx.tx_id, s->id); } else { /* start new inspection */ SCLogDebug("%p/%"PRIu64" Start sid %u", tx.tx_ptr, tx.tx_id, s->id); } /* call individual rule inspection */ RULE_PROFILING_START(p); const int r = DetectRunTxInspectRule(tv, de_ctx, det_ctx, p, f, flow_flags, alstate, &tx, s, inspect_flags, can, scratch); if (r == 1) { /* match */ DetectRunPostMatch(tv, det_ctx, p, s); const uint8_t alert_flags = (PACKET_ALERT_FLAG_STATE_MATCH | PACKET_ALERT_FLAG_TX); SCLogDebug("%p/%"PRIu64" sig %u (%u) matched", tx.tx_ptr, tx.tx_id, s->id, s->num); AlertQueueAppend(det_ctx, s, p, tx.tx_id, alert_flags); } DetectVarProcessList(det_ctx, p->flow, p); RULE_PROFILING_END(det_ctx, s, r, p); } det_ctx->tx_id = 0; det_ctx->tx_id_set = false; det_ctx->p = NULL; /* see if we have any updated state to store in the tx */ uint64_t new_detect_flags = 0; /* this side of the tx is done */ if (tx.tx_progress >= tx.tx_end_state) { new_detect_flags |= APP_LAYER_TX_INSPECTED_FLAG; SCLogDebug("%p/%"PRIu64" tx is done for direction %s. Flag %016"PRIx64, tx.tx_ptr, tx.tx_id, flow_flags & STREAM_TOSERVER ? "toserver" : "toclient", new_detect_flags); } if (tx.prefilter_flags != tx.prefilter_flags_orig) { new_detect_flags |= tx.prefilter_flags; DEBUG_VALIDATE_BUG_ON(new_detect_flags & APP_LAYER_TX_RESERVED_FLAGS); SCLogDebug("%p/%"PRIu64" updated prefilter flags %016"PRIx64" " "(was: %016"PRIx64") for direction %s. Flag %016"PRIx64, tx.tx_ptr, tx.tx_id, tx.prefilter_flags, tx.prefilter_flags_orig, flow_flags & STREAM_TOSERVER ? "toserver" : "toclient", new_detect_flags); } if (new_detect_flags != 0 && (new_detect_flags | tx.detect_flags) != tx.detect_flags) { new_detect_flags |= tx.detect_flags; DEBUG_VALIDATE_BUG_ON(new_detect_flags & APP_LAYER_TX_RESERVED_FLAGS); SCLogDebug("%p/%"PRIu64" Storing new flags %016"PRIx64" (was %016"PRIx64")", tx.tx_ptr, tx.tx_id, new_detect_flags, tx.detect_flags); StoreDetectFlags(&tx, flow_flags, ipproto, alproto, new_detect_flags); } next: InspectionBufferClean(det_ctx); if (!ires.has_next) break; } } static void DetectRunFrames(ThreadVars *tv, DetectEngineCtx *de_ctx, DetectEngineThreadCtx *det_ctx, Packet *p, Flow *f, DetectRunScratchpad *scratch) { const SigGroupHead *const sgh = scratch->sgh; const AppProto alproto = f->alproto; FramesContainer *frames_container = AppLayerFramesGetContainer(f); if (frames_container == NULL) { return; } Frames *frames; if (PKT_IS_TOSERVER(p)) { frames = &frames_container->toserver; } else { frames = &frames_container->toclient; } for (uint32_t idx = 0; idx < frames->cnt; idx++) { SCLogDebug("frame %u", idx); Frame *frame = FrameGetByIndex(frames, idx); if (frame == NULL) { continue; } det_ctx->frame_inspect_progress = 0; uint32_t array_idx = 0; uint32_t total_rules = det_ctx->match_array_cnt; /* run prefilter engines and merge results into a candidates array */ if (sgh->frame_engines) { // PACKET_PROFILING_DETECT_START(p, PROF_DETECT_PF_TX); DetectRunPrefilterFrame(det_ctx, sgh, p, frames, frame, alproto); // PACKET_PROFILING_DETECT_END(p, PROF_DETECT_PF_TX); SCLogDebug("%p/%" PRIi64 " rules added from prefilter: %u candidates", frame, frame->id, det_ctx->pmq.rule_id_array_cnt); total_rules += det_ctx->pmq.rule_id_array_cnt; if (!(RuleMatchCandidateTxArrayHasSpace( det_ctx, total_rules))) { // TODO is it safe to overload? RuleMatchCandidateTxArrayExpand(det_ctx, total_rules); } for (uint32_t i = 0; i < det_ctx->pmq.rule_id_array_cnt; i++) { const Signature *s = de_ctx->sig_array[det_ctx->pmq.rule_id_array[i]]; const SigIntId id = s->num; det_ctx->tx_candidates[array_idx].s = s; det_ctx->tx_candidates[array_idx].id = id; det_ctx->tx_candidates[array_idx].flags = NULL; det_ctx->tx_candidates[array_idx].stream_reset = 0; array_idx++; } PMQ_RESET(&det_ctx->pmq); } /* merge 'state' rules from the regular prefilter */ uint32_t x = array_idx; for (uint32_t i = 0; i < det_ctx->match_array_cnt; i++) { const Signature *s = det_ctx->match_array[i]; if (s->frame_inspect != NULL) { const SigIntId id = s->num; det_ctx->tx_candidates[array_idx].s = s; det_ctx->tx_candidates[array_idx].id = id; det_ctx->tx_candidates[array_idx].flags = NULL; det_ctx->tx_candidates[array_idx].stream_reset = 0; array_idx++; SCLogDebug("%p/%" PRIi64 " rule %u (%u) added from 'match' list", frame, frame->id, s->id, id); } } SCLogDebug("%p/%" PRIi64 " rules added from 'match' list: %u", frame, frame->id, array_idx - x); (void)x; /* run rules: inspect the match candidates */ for (uint32_t i = 0; i < array_idx; i++) { const Signature *s = det_ctx->tx_candidates[i].s; /* deduplicate: rules_array is sorted, but not deduplicated. * As they are back to back in that case we can check for it * here. We select the stored state one as that comes first * in the array. */ while ((i + 1) < array_idx && det_ctx->tx_candidates[i].s == det_ctx->tx_candidates[i + 1].s) { i++; } SCLogDebug("%p/%" PRIi64 " inspecting: sid %u (%u)", frame, frame->id, s->id, s->num); /* start new inspection */ SCLogDebug("%p/%" PRIi64 " Start sid %u", frame, frame->id, s->id); /* call individual rule inspection */ RULE_PROFILING_START(p); int r = DetectRunInspectRuleHeader(p, f, s, s->flags, s->proto.flags); if (r == 1) { r = DetectRunFrameInspectRule(tv, det_ctx, s, f, p, frames, frame); if (r == 1) { /* match */ DetectRunPostMatch(tv, det_ctx, p, s); const uint8_t alert_flags = (PACKET_ALERT_FLAG_STATE_MATCH | PACKET_ALERT_FLAG_FRAME); det_ctx->flags |= DETECT_ENGINE_THREAD_CTX_FRAME_ID_SET; det_ctx->frame_id = frame->id; SCLogDebug( "%p/%" PRIi64 " sig %u (%u) matched", frame, frame->id, s->id, s->num); AlertQueueAppend(det_ctx, s, p, frame->tx_id, alert_flags); } } DetectVarProcessList(det_ctx, p->flow, p); RULE_PROFILING_END(det_ctx, s, r, p); } /* update Frame::inspect_progress here instead of in the code above. The reason is that a * frame might be used more than once in buffers with transforms. */ if (frame->inspect_progress < det_ctx->frame_inspect_progress) { frame->inspect_progress = det_ctx->frame_inspect_progress; SCLogDebug("frame->inspect_progress: %" PRIu64 " -> updated", frame->inspect_progress); } else { SCLogDebug( "frame->inspect_progress: %" PRIu64 " -> not updated", frame->inspect_progress); } SCLogDebug("%p/%" PRIi64 " rules inspected, running cleanup", frame, frame->id); InspectionBufferClean(det_ctx); } } static DetectEngineThreadCtx *GetTenantById(HashTable *h, uint32_t id) { /* technically we need to pass a DetectEngineThreadCtx struct with the * tenant_id member. But as that member is the first in the struct, we * can use the id directly. */ return HashTableLookup(h, &id, 0); } static void DetectFlow(ThreadVars *tv, DetectEngineCtx *de_ctx, DetectEngineThreadCtx *det_ctx, Packet *p) { Flow *const f = p->flow; if (p->flags & PKT_NOPACKET_INSPECTION) { /* hack: if we are in pass the entire flow mode, we need to still * update the inspect_id forward. So test for the condition here, * and call the update code if necessary. */ const int pass = ((f->flags & FLOW_NOPACKET_INSPECTION)); if (pass) { uint8_t flags = STREAM_FLAGS_FOR_PACKET(p); flags = FlowGetDisruptionFlags(f, flags); if (f->alstate) { AppLayerParserSetTransactionInspectId(f, f->alparser, f->alstate, flags, true); } } SCLogDebug("p->pcap %"PRIu64": no detection on packet, " "PKT_NOPACKET_INSPECTION is set", p->pcap_cnt); return; } /* we check the flow drop here, and not the packet drop. This is * to allow stream engine "invalid" drop packets to still be * evaluated by the stream event rules. */ if (f->flags & FLOW_ACTION_DROP) { DEBUG_VALIDATE_BUG_ON(!(PKT_IS_PSEUDOPKT(p)) && !PacketCheckAction(p, ACTION_DROP)); SCReturn; } /* see if the packet matches one or more of the sigs */ (void)DetectRun(tv, de_ctx, det_ctx, p); } static void DetectNoFlow(ThreadVars *tv, DetectEngineCtx *de_ctx, DetectEngineThreadCtx *det_ctx, Packet *p) { /* No need to perform any detection on this packet, if the given flag is set.*/ if ((p->flags & PKT_NOPACKET_INSPECTION) || (PacketCheckAction(p, ACTION_DROP))) { return; } /* see if the packet matches one or more of the sigs */ DetectRun(tv, de_ctx, det_ctx, p); return; } /** \brief Detection engine thread wrapper. * \param tv thread vars * \param p packet to inspect * \param data thread specific data * \param pq packet queue * \retval TM_ECODE_FAILED error * \retval TM_ECODE_OK ok */ TmEcode Detect(ThreadVars *tv, Packet *p, void *data) { DEBUG_VALIDATE_PACKET(p); DetectEngineCtx *de_ctx = NULL; DetectEngineThreadCtx *det_ctx = (DetectEngineThreadCtx *)data; if (det_ctx == NULL) { printf("ERROR: Detect has no thread ctx\n"); goto error; } if (unlikely(SC_ATOMIC_GET(det_ctx->so_far_used_by_detect) == 0)) { (void)SC_ATOMIC_SET(det_ctx->so_far_used_by_detect, 1); SCLogDebug("Detect Engine using new det_ctx - %p", det_ctx); } /* if in MT mode _and_ we have tenants registered, use * MT logic. */ if (det_ctx->mt_det_ctxs_cnt > 0 && det_ctx->TenantGetId != NULL) { uint32_t tenant_id = p->tenant_id; if (tenant_id == 0) tenant_id = det_ctx->TenantGetId(det_ctx, p); if (tenant_id > 0 && tenant_id < det_ctx->mt_det_ctxs_cnt) { p->tenant_id = tenant_id; det_ctx = GetTenantById(det_ctx->mt_det_ctxs_hash, tenant_id); if (det_ctx == NULL) return TM_ECODE_OK; de_ctx = det_ctx->de_ctx; if (de_ctx == NULL) return TM_ECODE_OK; if (unlikely(SC_ATOMIC_GET(det_ctx->so_far_used_by_detect) == 0)) { (void)SC_ATOMIC_SET(det_ctx->so_far_used_by_detect, 1); SCLogDebug("MT de_ctx %p det_ctx %p (tenant %u)", de_ctx, det_ctx, tenant_id); } } else { /* use default if no tenants are registered for this packet */ de_ctx = det_ctx->de_ctx; } } else { de_ctx = det_ctx->de_ctx; } if (p->flow) { DetectFlow(tv, de_ctx, det_ctx, p); } else { DetectNoFlow(tv, de_ctx, det_ctx, p); } #ifdef PROFILE_RULES /* aggregate statistics */ struct timeval ts; gettimeofday(&ts, NULL); if (ts.tv_sec != det_ctx->rule_perf_last_sync) { SCProfilingRuleThreatAggregate(det_ctx); det_ctx->rule_perf_last_sync = ts.tv_sec; } #endif return TM_ECODE_OK; error: return TM_ECODE_FAILED; } /** \brief disable file features we don't need * Called if we have no detection engine. */ void DisableDetectFlowFileFlags(Flow *f) { DetectPostInspectFileFlagsUpdate(f, NULL /* no sgh */, STREAM_TOSERVER); DetectPostInspectFileFlagsUpdate(f, NULL /* no sgh */, STREAM_TOCLIENT); } #ifdef UNITTESTS /** * \brief wrapper for old tests */ void SigMatchSignatures( ThreadVars *tv, DetectEngineCtx *de_ctx, DetectEngineThreadCtx *det_ctx, Packet *p) { if (p->flow) { DetectFlow(tv, de_ctx, det_ctx, p); } else { DetectNoFlow(tv, de_ctx, det_ctx, p); } } #endif /* * TESTS */ #ifdef UNITTESTS #include "tests/detect.c" #endif