detect-engine-prefilter.c

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/* Copyright (C) 2016-2025 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 <victor@inliniac.net>
 *
 * Prefilter engine
 *
 * Prefilter engines have as purpose to check for a critical common part of
 * a set of rules. If the condition is present in the traffic, the rules
 * will have to be inspected individually. Otherwise, the rules can be
 * skipped.
 *
 * The best example of this is the MPM. From each rule take a pattern and
 * add it to the MPM state machine. Inspect that in one step and only
 * individually inspect the rules that had a match in MPM.
 *
 * This prefilter API is designed to abstract this logic so that it becomes
 * easier to add other types of prefilters.
 *
 * The prefilter engines are structured as a simple list of engines. Each
 * engine checks for a condition using it's callback function and private
 * data. It then adds the rule match candidates to the PrefilterRuleStore
 * structure.
 *
 * After the engines have run the resulting list of match candidates is
 * sorted by the rule id's so that the individual inspection happens in
 * the correct order.
 */
 
#include "suricata-common.h"
#include "suricata.h"
 
#include "detect-engine.h"
#include "detect-engine-prefilter.h"
#include "detect-engine-mpm.h"
#include "detect-engine-frame.h"
#include "detect-engine-uint.h"
 
#include "app-layer-parser.h"
#include "app-layer-htp.h"
 
#include "util-profiling.h"
#include "util-validate.h"
#include "util-hash-string.h"
 
static int PrefilterStoreGetId(DetectEngineCtx *de_ctx,
        const char *name, void (*FreeFunc)(void *));
static const PrefilterStore *PrefilterStoreGetStore(const DetectEngineCtx *de_ctx,
        const uint32_t id);
 
static inline void QuickSortSigIntId(SigIntId *sids, uint32_t n)
{
    if (n < 2)
        return;
    SigIntId p = sids[n / 2];
    SigIntId *l = sids;
    SigIntId *r = sids + n - 1;
    while (l <= r) {
        if (*l < p)
            l++;
        else if (*r > p)
            r--;
        else {
            SigIntId t = *l;
            *l = *r;
            *r = t;
            l++;
            r--;
        }
    }
    QuickSortSigIntId(sids, r - sids + 1);
    QuickSortSigIntId(l, sids + n - l);
}
 
/**
 * \brief run prefilter engines on a transaction
 */
void DetectRunPrefilterTx(DetectEngineThreadCtx *det_ctx,
        const SigGroupHead *sgh,
        Packet *p,
        const uint8_t ipproto,
        const uint8_t flow_flags,
        const AppProto alproto,
        void *alstate,
        DetectTransaction *tx)
{
    /* reset rule store */
    det_ctx->pmq.rule_id_array_cnt = 0;
 
    SCLogDebug("packet %" PRIu64 " tx %p progress %d tx->detect_progress %02x", p->pcap_cnt,
            tx->tx_ptr, tx->tx_progress, tx->detect_progress);
 
    PrefilterEngine *engine = sgh->tx_engines;
    do {
        // based on flow alproto, and engine, we get right tx_ptr
        void *tx_ptr = DetectGetInnerTx(tx->tx_ptr, alproto, engine->alproto, flow_flags);
        if (tx_ptr == NULL) {
            // incompatible engine->alproto with flow alproto
            goto next;
        }
 
        if (engine->ctx.tx_min_progress != -1) {
#ifdef DEBUG
            const char *pname = AppLayerParserGetStateNameById(ipproto, engine->alproto,
                    engine->ctx.tx_min_progress, flow_flags & (STREAM_TOSERVER | STREAM_TOCLIENT));
            SCLogDebug("engine %p min_progress %d %s:%s", engine, engine->ctx.tx_min_progress,
                    AppProtoToString(engine->alproto), pname);
#endif
            /* if engine needs tx state to be higher, break out. */
            if (engine->ctx.tx_min_progress > tx->tx_progress)
                break;
            if (tx->tx_progress > engine->ctx.tx_min_progress) {
                SCLogDebug("tx->tx_progress %u > engine->ctx.tx_min_progress %d", tx->tx_progress,
                        engine->ctx.tx_min_progress);
 
                /* if state value is at or beyond engine state, we can skip it. It means we ran at
                 * least once already. */
                if (tx->detect_progress > engine->ctx.tx_min_progress) {
                    SCLogDebug("tx already marked progress as beyond engine: %u > %u",
                            tx->detect_progress, engine->ctx.tx_min_progress);
                    goto next;
                } else {
                    SCLogDebug("tx->tx_progress %u > engine->ctx.tx_min_progress %d: "
                               "tx->detect_progress %u",
                            tx->tx_progress, engine->ctx.tx_min_progress, tx->detect_progress);
                }
            }
#ifdef DEBUG
            uint32_t old = det_ctx->pmq.rule_id_array_cnt;
#endif
            PREFILTER_PROFILING_START(det_ctx);
            engine->cb.PrefilterTx(det_ctx, engine->pectx, p, p->flow, tx_ptr, tx->tx_id,
                    tx->tx_data_ptr, flow_flags);
            PREFILTER_PROFILING_END(det_ctx, engine->gid);
            SCLogDebug("engine %p min_progress %d %s:%s: results %u", engine,
                    engine->ctx.tx_min_progress, AppProtoToString(engine->alproto), pname,
                    det_ctx->pmq.rule_id_array_cnt - old);
 
            if (tx->tx_progress > engine->ctx.tx_min_progress && engine->is_last_for_progress) {
                /* track with an offset of one, so that tx->progress 0 complete is tracked
                 * as 1, progress 1 as 2, etc. This is to allow 0 to mean: nothing tracked, even
                 * though a parser may use 0 as a valid value. */
                tx->detect_progress = engine->ctx.tx_min_progress + 1;
                SCLogDebug("tx->tx_progress %d engine->ctx.tx_min_progress %d "
                           "engine->is_last_for_progress %d => tx->detect_progress updated to %02x",
                        tx->tx_progress, engine->ctx.tx_min_progress, engine->is_last_for_progress,
                        tx->detect_progress);
            }
        } else {
            PREFILTER_PROFILING_START(det_ctx);
            engine->cb.PrefilterTx(det_ctx, engine->pectx, p, p->flow, tx_ptr, tx->tx_id,
                    tx->tx_data_ptr, flow_flags);
            PREFILTER_PROFILING_END(det_ctx, engine->gid);
        }
    next:
        if (engine->is_last)
            break;
        engine++;
    } while (1);
 
    /* Sort the rule list to lets look at pmq.
     * NOTE due to merging of 'stream' pmqs we *MAY* have duplicate entries */
    if (likely(det_ctx->pmq.rule_id_array_cnt > 1)) {
        PACKET_PROFILING_DETECT_START(p, PROF_DETECT_PF_SORT1);
        QuickSortSigIntId(det_ctx->pmq.rule_id_array, det_ctx->pmq.rule_id_array_cnt);
        PACKET_PROFILING_DETECT_END(p, PROF_DETECT_PF_SORT1);
    }
}
 
/** \brief invoke post-rule match "prefilter" engines
 *
 * Invoke prefilter engines that depend on a rule match to run.
 * e.g. the flowbits:set prefilter that adds sids that depend on
 * a flowbit "set" to the match array.
 */
void PrefilterPostRuleMatch(
        DetectEngineThreadCtx *det_ctx, const SigGroupHead *sgh, Packet *p, Flow *f)
{
    SCLogDebug("post-rule-match engines %p", sgh->post_rule_match_engines);
    if (sgh->post_rule_match_engines) {
        PrefilterEngine *engine = sgh->post_rule_match_engines;
        do {
            SCLogDebug("running post-rule-match engine");
            PREFILTER_PROFILING_START(det_ctx);
            engine->cb.PrefilterPostRule(det_ctx, engine->pectx, p, f);
            PREFILTER_PROFILING_END(det_ctx, engine->gid);
 
            if (engine->is_last)
                break;
            engine++;
        } while (1);
 
        if (det_ctx->pmq.rule_id_array_cnt > 1) {
            QuickSortSigIntId(det_ctx->pmq.rule_id_array, det_ctx->pmq.rule_id_array_cnt);
        }
    }
}
 
void Prefilter(DetectEngineThreadCtx *det_ctx, const SigGroupHead *sgh, Packet *p,
        const uint8_t flags, const SignatureMask mask)
{
    SCEnter();
#if 0
    /* TODO review this check */
    SCLogDebug("sgh %p frame_engines %p", sgh, sgh->frame_engines);
    if (p->proto == IPPROTO_TCP && sgh->frame_engines && p->flow &&
            p->flow->alproto != ALPROTO_UNKNOWN && p->flow->alparser != NULL) {
        PACKET_PROFILING_DETECT_START(p, PROF_DETECT_PF_RECORD);
        PrefilterFrames(det_ctx, sgh, p, flags, p->flow->alproto);
        PACKET_PROFILING_DETECT_END(p, PROF_DETECT_PF_RECORD);
    }
#endif
    if (sgh->pkt_engines) {
        PACKET_PROFILING_DETECT_START(p, PROF_DETECT_PF_PKT);
        /* run packet engines */
        PrefilterEngine *engine = sgh->pkt_engines;
        do {
            /* run engine if:
             * mask matches
             * no hook is used OR hook matches
             */
            if (((engine->ctx.pkt.mask & mask) == engine->ctx.pkt.mask) &&
                    (engine->ctx.pkt.hook == 0 || (p->pkt_hooks & BIT_U16(engine->ctx.pkt.hook)))) {
                PREFILTER_PROFILING_START(det_ctx);
                engine->cb.Prefilter(det_ctx, p, engine->pectx);
                PREFILTER_PROFILING_END(det_ctx, engine->gid);
            }
 
            if (engine->is_last)
                break;
            engine++;
        } while (1);
        PACKET_PROFILING_DETECT_END(p, PROF_DETECT_PF_PKT);
    }
 
    /* run payload inspecting engines */
    if (sgh->payload_engines &&
        (p->payload_len || (p->flags & PKT_DETECT_HAS_STREAMDATA)) &&
        !(p->flags & PKT_NOPAYLOAD_INSPECTION))
    {
        PACKET_PROFILING_DETECT_START(p, PROF_DETECT_PF_PAYLOAD);
        PrefilterEngine *engine = sgh->payload_engines;
        while (1) {
            PREFILTER_PROFILING_START(det_ctx);
            engine->cb.Prefilter(det_ctx, p, engine->pectx);
            PREFILTER_PROFILING_END(det_ctx, engine->gid);
 
            if (engine->is_last)
                break;
            engine++;
        }
        PACKET_PROFILING_DETECT_END(p, PROF_DETECT_PF_PAYLOAD);
    }
 
    /* Sort the rule list to lets look at pmq.
     * NOTE due to merging of 'stream' pmqs we *MAY* have duplicate entries */
    if (likely(det_ctx->pmq.rule_id_array_cnt > 1)) {
        PACKET_PROFILING_DETECT_START(p, PROF_DETECT_PF_SORT1);
        QuickSortSigIntId(det_ctx->pmq.rule_id_array, det_ctx->pmq.rule_id_array_cnt);
        PACKET_PROFILING_DETECT_END(p, PROF_DETECT_PF_SORT1);
    }
    SCReturn;
}
 
int PrefilterAppendEngine(DetectEngineCtx *de_ctx, SigGroupHead *sgh, PrefilterPktFn PrefilterFunc,
        SignatureMask mask, enum SignatureHookPkt hook, void *pectx, void (*FreeFunc)(void *pectx),
        const char *name)
{
    if (sgh == NULL || PrefilterFunc == NULL || pectx == NULL)
        return -1;
 
    PrefilterEngineList *e = SCMallocAligned(sizeof(*e), CLS);
    if (e == NULL)
        return -1;
    memset(e, 0x00, sizeof(*e));
 
    // TODO right now we represent the hook in a u8 in the prefilter engine for space reasons.
    BUG_ON(hook >= 8);
 
    e->Prefilter = PrefilterFunc;
    e->pectx = pectx;
    e->Free = FreeFunc;
    e->pkt_mask = mask;
    e->pkt_hook = hook;
 
    if (sgh->init->pkt_engines == NULL) {
        sgh->init->pkt_engines = e;
    } else {
        PrefilterEngineList *t = sgh->init->pkt_engines;
        while (t->next != NULL) {
            t = t->next;
        }
 
        t->next = e;
        e->id = t->id + 1;
    }
 
    e->name = name;
    e->gid = PrefilterStoreGetId(de_ctx, e->name, e->Free);
    return 0;
}
 
int PrefilterAppendPayloadEngine(DetectEngineCtx *de_ctx, SigGroupHead *sgh,
        PrefilterPktFn PrefilterFunc, void *pectx, void (*FreeFunc)(void *pectx), const char *name)
{
    if (sgh == NULL || PrefilterFunc == NULL || pectx == NULL)
        return -1;
 
    PrefilterEngineList *e = SCMallocAligned(sizeof(*e), CLS);
    if (e == NULL)
        return -1;
    memset(e, 0x00, sizeof(*e));
 
    e->Prefilter = PrefilterFunc;
    e->pectx = pectx;
    e->Free = FreeFunc;
 
    if (sgh->init->payload_engines == NULL) {
        sgh->init->payload_engines = e;
    } else {
        PrefilterEngineList *t = sgh->init->payload_engines;
        while (t->next != NULL) {
            t = t->next;
        }
 
        t->next = e;
        e->id = t->id + 1;
    }
 
    e->name = name;
    e->gid = PrefilterStoreGetId(de_ctx, e->name, e->Free);
    return 0;
}
 
int PrefilterAppendTxEngine(DetectEngineCtx *de_ctx, SigGroupHead *sgh,
        PrefilterTxFn PrefilterTxFunc, AppProto alproto, int tx_min_progress, void *pectx,
        void (*FreeFunc)(void *pectx), const char *name)
{
    if (sgh == NULL || PrefilterTxFunc == NULL || pectx == NULL)
        return -1;
 
    PrefilterEngineList *e = SCMallocAligned(sizeof(*e), CLS);
    if (e == NULL)
        return -1;
    memset(e, 0x00, sizeof(*e));
 
    e->PrefilterTx = PrefilterTxFunc;
    e->pectx = pectx;
    e->alproto = alproto;
    // TODO change function prototype ?
    DEBUG_VALIDATE_BUG_ON(tx_min_progress > INT8_MAX);
    e->tx_min_progress = (uint8_t)tx_min_progress;
    e->Free = FreeFunc;
 
    if (sgh->init->tx_engines == NULL) {
        sgh->init->tx_engines = e;
    } else {
        PrefilterEngineList *t = sgh->init->tx_engines;
        while (t->next != NULL) {
            t = t->next;
        }
 
        t->next = e;
        e->id = t->id + 1;
    }
 
    e->name = name;
    e->gid = PrefilterStoreGetId(de_ctx, e->name, e->Free);
    return 0;
}
 
int PrefilterAppendFrameEngine(DetectEngineCtx *de_ctx, SigGroupHead *sgh,
        PrefilterFrameFn PrefilterFrameFunc, AppProto alproto, uint8_t frame_type, void *pectx,
        void (*FreeFunc)(void *pectx), const char *name)
{
    if (sgh == NULL || PrefilterFrameFunc == NULL || pectx == NULL)
        return -1;
 
    PrefilterEngineList *e = SCMallocAligned(sizeof(*e), CLS);
    if (e == NULL)
        return -1;
    memset(e, 0x00, sizeof(*e));
 
    e->frame_type = frame_type;
    e->alproto = alproto;
    e->PrefilterFrame = PrefilterFrameFunc;
    e->pectx = pectx;
    e->Free = FreeFunc;
 
    if (sgh->init->frame_engines == NULL) {
        sgh->init->frame_engines = e;
    } else {
        PrefilterEngineList *t = sgh->init->frame_engines;
        while (t->next != NULL) {
            t = t->next;
        }
 
        t->next = e;
        e->id = t->id + 1;
    }
 
    e->name = name;
    e->gid = PrefilterStoreGetId(de_ctx, e->name, e->Free);
    return 0;
}
 
int PrefilterAppendPostRuleEngine(DetectEngineCtx *de_ctx, SigGroupHead *sgh,
        void (*PrefilterPostRuleFunc)(
                DetectEngineThreadCtx *det_ctx, const void *pectx, Packet *p, Flow *f),
        void *pectx, void (*FreeFunc)(void *pectx), const char *name)
{
    if (sgh == NULL || PrefilterPostRuleFunc == NULL || pectx == NULL)
        return -1;
 
    PrefilterEngineList *e = SCMallocAligned(sizeof(*e), CLS);
    if (e == NULL)
        return -1;
    memset(e, 0x00, sizeof(*e));
    e->PrefilterPostRule = PrefilterPostRuleFunc;
    e->pectx = pectx;
    e->Free = FreeFunc;
 
    if (sgh->init->post_rule_match_engines == NULL) {
        sgh->init->post_rule_match_engines = e;
    } else {
        PrefilterEngineList *t = sgh->init->post_rule_match_engines;
        while (t->next != NULL) {
            t = t->next;
        }
 
        t->next = e;
        e->id = t->id + 1;
    }
 
    e->name = name;
    e->gid = PrefilterStoreGetId(de_ctx, e->name, e->Free);
    return 0;
}
 
static void PrefilterFreeEngineList(PrefilterEngineList *e)
{
    if (e->Free && e->pectx) {
        e->Free(e->pectx);
    }
    SCFreeAligned(e);
}
 
void PrefilterFreeEnginesList(PrefilterEngineList *list)
{
    PrefilterEngineList *t = list;
 
    while (t != NULL) {
        PrefilterEngineList *next = t->next;
        PrefilterFreeEngineList(t);
        t = next;
    }
}
 
static void PrefilterFreeEngines(const DetectEngineCtx *de_ctx, PrefilterEngine *list)
{
    PrefilterEngine *t = list;
 
    while (1) {
        const PrefilterStore *s = PrefilterStoreGetStore(de_ctx, t->gid);
        if (s && s->FreeFunc && t->pectx) {
            s->FreeFunc(t->pectx);
        }
 
        if (t->is_last)
            break;
        t++;
    }
    SCFreeAligned(list);
}
 
void PrefilterCleanupRuleGroup(const DetectEngineCtx *de_ctx, SigGroupHead *sgh)
{
    if (sgh->pkt_engines) {
        PrefilterFreeEngines(de_ctx, sgh->pkt_engines);
        sgh->pkt_engines = NULL;
    }
    if (sgh->payload_engines) {
        PrefilterFreeEngines(de_ctx, sgh->payload_engines);
        sgh->payload_engines = NULL;
    }
    if (sgh->tx_engines) {
        PrefilterFreeEngines(de_ctx, sgh->tx_engines);
        sgh->tx_engines = NULL;
    }
    if (sgh->frame_engines) {
        PrefilterFreeEngines(de_ctx, sgh->frame_engines);
        sgh->frame_engines = NULL;
    }
    if (sgh->post_rule_match_engines) {
        PrefilterFreeEngines(de_ctx, sgh->post_rule_match_engines);
        sgh->post_rule_match_engines = NULL;
    }
}
 
static int PrefilterSetupRuleGroupSortHelper(const void *a, const void *b)
{
    const PrefilterEngine *s0 = a;
    const PrefilterEngine *s1 = b;
    if (s1->ctx.tx_min_progress == s0->ctx.tx_min_progress) {
        if (s1->alproto == s0->alproto) {
            return s0->local_id > s1->local_id ? 1 : -1;
        } else {
            return s0->alproto > s1->alproto ? 1 : -1;
        }
    } else {
        return s0->ctx.tx_min_progress > s1->ctx.tx_min_progress ? 1 : -1;
    }
}
 
/** prefilter engine data for the non-prefilter engine for the prefilter API */
struct PrefilterNonPFDataSig {
    uint32_t sid : 30;
    uint32_t type : 2; /**< type for `value` field below: 0:alproto 1:dport 2:dsize */
    uint16_t value;
    /* since we have 2 more bytes available due to padding, we can add some additional
     * filters here. */
    union {
        struct {
            SignatureMask sig_mask;
        } pkt;
        struct {
            /* filter for frame type */
            uint8_t type;
        } frame;
        struct {
            uint8_t foo; // TODO unused
        } app;
    };
};
 
struct PrefilterNonPFData {
    uint32_t size;
    struct PrefilterNonPFDataSig array[];
};
 
struct PrefilterNonPFDataTx {
    uint32_t size;
    uint32_t array[];
};
 
/** \internal
 *  \brief wrapper for use in APIs */
static void PrefilterNonPFDataFree(void *data)
{
    SCFree(data);
}
 
static void PrefilterTxNonPF(DetectEngineThreadCtx *det_ctx, const void *pectx, Packet *p, Flow *f,
        void *tx, const uint64_t tx_id, const AppLayerTxData *tx_data, const uint8_t flags)
{
    const struct PrefilterNonPFDataTx *data = (const struct PrefilterNonPFDataTx *)pectx;
    SCLogDebug("adding %u sids", data->size);
    PrefilterAddSids(&det_ctx->pmq, data->array, data->size);
}
 
#ifdef NONPF_PKT_STATS
static thread_local uint64_t prefilter_pkt_nonpf_called = 0;
static thread_local uint64_t prefilter_pkt_nonpf_mask_fail = 0;
static thread_local uint64_t prefilter_pkt_nonpf_alproto_fail = 0;
static thread_local uint64_t prefilter_pkt_nonpf_dsize_fail = 0;
static thread_local uint64_t prefilter_pkt_nonpf_dport_fail = 0;
static thread_local uint64_t prefilter_pkt_nonpf_sids = 0;
#define NONPF_PKT_STATS_INCR(s) (s)++
#else
#define NONPF_PKT_STATS_INCR(s)
#endif
 
void PrefilterPktNonPFStatsDump(void)
{
#ifdef NONPF_PKT_STATS
    SCLogDebug("prefilter non-pf: called:%" PRIu64 ", mask_fail:%" PRIu64 ", alproto fail:%" PRIu64
               ", dport fail:%" PRIu64 ", dsize fail:%" PRIu64 ", sids:%" PRIu64
               ", avg sids:%" PRIu64,
            prefilter_pkt_nonpf_called, prefilter_pkt_nonpf_mask_fail,
            prefilter_pkt_nonpf_alproto_fail, prefilter_pkt_nonpf_dport_fail,
            prefilter_pkt_nonpf_dsize_fail, prefilter_pkt_nonpf_sids,
            prefilter_pkt_nonpf_called ? prefilter_pkt_nonpf_sids / prefilter_pkt_nonpf_called : 0);
#endif
}
 
static void PrefilterPktNonPF(DetectEngineThreadCtx *det_ctx, Packet *p, const void *pectx)
{
    const uint16_t alproto = p->flow ? p->flow->alproto : ALPROTO_UNKNOWN;
    const SignatureMask mask = p->sig_mask;
    const struct PrefilterNonPFData *data = (const struct PrefilterNonPFData *)pectx;
    SCLogDebug("adding %u sids", data->size);
    NONPF_PKT_STATS_INCR(prefilter_pkt_nonpf_called);
    for (uint32_t i = 0; i < data->size; i++) {
        const struct PrefilterNonPFDataSig *ds = &data->array[i];
        const SignatureMask rule_mask = ds->pkt.sig_mask;
        if ((rule_mask & mask) == rule_mask) {
            switch (ds->type) {
                case 0:
                    if (ds->value == ALPROTO_UNKNOWN || AppProtoEquals(ds->value, alproto)) {
                        const uint32_t sid = ds->sid;
                        PrefilterAddSids(&det_ctx->pmq, &sid, 1);
                        NONPF_PKT_STATS_INCR(prefilter_pkt_nonpf_sids);
                    } else {
                        NONPF_PKT_STATS_INCR(prefilter_pkt_nonpf_alproto_fail);
                    }
                    break;
                case 1:
                    if (ds->value == p->dp) {
                        const uint32_t sid = ds->sid;
                        PrefilterAddSids(&det_ctx->pmq, &sid, 1);
                        NONPF_PKT_STATS_INCR(prefilter_pkt_nonpf_sids);
                    } else {
                        NONPF_PKT_STATS_INCR(prefilter_pkt_nonpf_dport_fail);
                    }
                    break;
                case 2:
                    if (ds->value == p->payload_len) {
                        const uint32_t sid = ds->sid;
                        PrefilterAddSids(&det_ctx->pmq, &sid, 1);
                        NONPF_PKT_STATS_INCR(prefilter_pkt_nonpf_sids);
                    } else {
                        NONPF_PKT_STATS_INCR(prefilter_pkt_nonpf_dsize_fail);
                    }
                    break;
            }
        } else {
            NONPF_PKT_STATS_INCR(prefilter_pkt_nonpf_mask_fail);
        }
    }
}
 
static void PrefilterPktNonPFHookFlowStart(
        DetectEngineThreadCtx *det_ctx, Packet *p, const void *pectx)
{
    if (p->flowflags & (FLOW_PKT_TOSERVER_FIRST | FLOW_PKT_TOCLIENT_FIRST)) {
        PrefilterPktNonPF(det_ctx, p, pectx);
    }
}
 
/** \internal
 *  \brief engine to select the non-prefilter rules for frames
 *  Checks the alproto and type as well.
 *  Direction needs no checking as the rule groups are per direction. */
static void PrefilterFrameNonPF(DetectEngineThreadCtx *det_ctx, const void *pectx, Packet *p,
        const Frames *frames, const Frame *frame)
{
    DEBUG_VALIDATE_BUG_ON(p->flow == NULL);
    const uint16_t alproto = p->flow->alproto;
    const struct PrefilterNonPFData *data = (const struct PrefilterNonPFData *)pectx;
    SCLogDebug("adding %u sids", data->size);
    for (uint32_t i = 0; i < data->size; i++) {
        const struct PrefilterNonPFDataSig *ds = &data->array[i];
        if (ds->frame.type == frame->type &&
                (ds->value == ALPROTO_UNKNOWN || AppProtoEquals(ds->value, alproto))) {
            const uint32_t sid = ds->sid;
            PrefilterAddSids(&det_ctx->pmq, &sid, 1);
        }
    }
}
 
/* helper funcs for the non prefilter names hash */
 
static uint32_t NonPFNamesHash(HashTable *h, void *data, uint16_t _len)
{
    const char *str = data;
    return StringHashDjb2((const uint8_t *)str, (uint16_t)strlen(str)) % h->array_size;
}
 
static char NonPFNamesCompare(void *data1, uint16_t _len1, void *data2, uint16_t len2)
{
    const char *s1 = data1;
    const char *s2 = data2;
    return StringHashCompareFunc(data1, (uint16_t)strlen(s1), data2, (uint16_t)strlen(s2));
}
 
static void NonPFNamesFree(void *data)
{
    SCFree(data);
}
 
/* helper funcs for assembling non-prefilter engines */
 
struct TxNonPFData {
    AppProto alproto;
    int dir;      /**< 0: toserver, 1: toclient */
    int progress; /**< progress state value to register at */
    int sig_list; /**< special handling: normally 0, but for special cases (app-layer-state,
                     app-layer-event) use the list id to create separate engines */
    uint32_t sigs_cnt;
    struct PrefilterNonPFDataSig *sigs;
    const char *engine_name; /**< pointer to name owned by DetectEngineCtx::non_pf_engine_names */
};
 
static uint32_t TxNonPFHash(HashListTable *h, void *data, uint16_t _len)
{
    struct TxNonPFData *d = data;
    return (d->alproto + d->progress + d->dir + d->sig_list) % h->array_size;
}
 
static char TxNonPFCompare(void *data1, uint16_t _len1, void *data2, uint16_t len2)
{
    struct TxNonPFData *d1 = data1;
    struct TxNonPFData *d2 = data2;
    return d1->alproto == d2->alproto && d1->progress == d2->progress && d1->dir == d2->dir &&
           d1->sig_list == d2->sig_list;
}
 
static void TxNonPFFree(void *data)
{
    struct TxNonPFData *d = data;
    SCFree(d->sigs);
    SCFree(d);
}
 
static int TxNonPFAddSig(DetectEngineCtx *de_ctx, HashListTable *tx_engines_hash,
        const AppProto alproto, const int dir, const int16_t progress, const int sig_list,
        const char *name, const Signature *s)
{
    const uint32_t max_sids = DetectEngineGetMaxSigId(de_ctx);
 
    struct TxNonPFData lookup = {
        .alproto = alproto,
        .dir = dir,
        .progress = progress,
        .sig_list = sig_list,
        .sigs_cnt = 0,
        .sigs = NULL,
        .engine_name = NULL,
    };
    struct TxNonPFData *e = HashListTableLookup(tx_engines_hash, &lookup, 0);
    if (e != NULL) {
        bool found = false;
        // avoid adding same sid multiple times
        for (uint32_t y = 0; y < e->sigs_cnt; y++) {
            if (e->sigs[y].sid == s->num) {
                found = true;
                break;
            }
        }
        if (!found) {
            BUG_ON(e->sigs_cnt == max_sids);
            e->sigs[e->sigs_cnt].sid = s->num;
            e->sigs[e->sigs_cnt].value = alproto;
            e->sigs_cnt++;
        }
        return 0;
    }
 
    struct TxNonPFData *add = SCCalloc(1, sizeof(*add));
    if (add == NULL) {
        return -1;
    }
    add->dir = dir;
    add->alproto = alproto;
    add->progress = progress;
    add->sig_list = sig_list;
    add->sigs = SCCalloc(max_sids, sizeof(struct PrefilterNonPFDataSig));
    if (add->sigs == NULL) {
        SCFree(add);
        return -1;
    }
    add->sigs_cnt = 0;
    add->sigs[add->sigs_cnt].sid = s->num;
    add->sigs[add->sigs_cnt].value = alproto;
    add->sigs_cnt++;
 
    char engine_name[128];
    snprintf(engine_name, sizeof(engine_name), "%s:%s:non_pf:%s", AppProtoToString(alproto), name,
            dir == 0 ? "toserver" : "toclient");
    char *engine_name_heap = SCStrdup(engine_name);
    if (engine_name_heap == NULL) {
        SCFree(add->sigs);
        SCFree(add);
        return -1;
    }
    int result = HashTableAdd(
            de_ctx->non_pf_engine_names, engine_name_heap, (uint16_t)strlen(engine_name_heap));
    if (result != 0) {
        SCFree(add->sigs);
        SCFree(add);
        return -1;
    }
 
    add->engine_name = engine_name_heap;
    SCLogDebug("engine_name_heap %s", engine_name_heap);
 
    int ret = HashListTableAdd(tx_engines_hash, add, 0);
    if (ret != 0) {
        SCFree(add->sigs);
        SCFree(add);
        return -1;
    }
 
    return 0;
}
 
/** \internal
 *  \brief setup non-prefilter rules in special "non-prefilter" engines that are registered in the
 * prefilter logic.
 *
 *  \retval 0 ok
 *  \retval -1 error
 */
static int SetupNonPrefilter(DetectEngineCtx *de_ctx, SigGroupHead *sgh)
{
    const uint32_t max_sids = DetectEngineGetMaxSigId(de_ctx);
    SCLogDebug("max_sids %u", max_sids);
    struct PrefilterNonPFDataSig *pkt_non_pf_array = SCCalloc(max_sids, sizeof(*pkt_non_pf_array));
    if (pkt_non_pf_array == NULL) {
        return -1;
    }
    uint32_t pkt_non_pf_array_size = 0;
    struct PrefilterNonPFDataSig *frame_non_pf_array =
            SCCalloc(max_sids, sizeof(*frame_non_pf_array));
    if (frame_non_pf_array == NULL) {
        SCFree(pkt_non_pf_array);
        return -1;
    }
    uint32_t frame_non_pf_array_size = 0;
 
    struct PrefilterNonPFDataSig *pkt_hook_flow_start_non_pf_array =
            SCCalloc(max_sids, sizeof(*pkt_hook_flow_start_non_pf_array));
    if (pkt_hook_flow_start_non_pf_array == NULL) {
        SCFree(pkt_non_pf_array);
        SCFree(frame_non_pf_array);
        return -1;
    }
    uint32_t pkt_hook_flow_start_non_pf_array_size = 0;
    SignatureMask pkt_hook_flow_start_mask = 0;
    bool pkt_hook_flow_start_mask_init = false;
 
    HashListTable *tx_engines_hash =
            HashListTableInit(256, TxNonPFHash, TxNonPFCompare, TxNonPFFree);
    if (tx_engines_hash == NULL) {
        SCFree(pkt_non_pf_array);
        SCFree(pkt_hook_flow_start_non_pf_array);
        SCFree(frame_non_pf_array);
        return -1;
    }
 
    if (de_ctx->non_pf_engine_names == NULL) {
        de_ctx->non_pf_engine_names =
                HashTableInit(512, NonPFNamesHash, NonPFNamesCompare, NonPFNamesFree);
        if (de_ctx->non_pf_engine_names == NULL) {
            SCFree(pkt_non_pf_array);
            SCFree(pkt_hook_flow_start_non_pf_array);
            SCFree(frame_non_pf_array);
            HashListTableFree(tx_engines_hash);
            return -1;
        }
    }
 
    SignatureMask pkt_mask = 0;
    bool pkt_mask_init = false;
#ifdef NONPF_PKT_STATS
    uint32_t nonpf_pkt_alproto = 0;
    uint32_t nonpf_pkt_dsize = 0;
    uint32_t nonpf_pkt_dport = 0;
#endif
    const int app_events_list_id = DetectBufferTypeGetByName("app-layer-events");
    SCLogDebug("app_events_list_id %d", app_events_list_id);
    const int app_state_list_id = DetectBufferTypeGetByName("app-layer-state");
    SCLogDebug("app_state_list_id %d", app_state_list_id);
    for (uint32_t sig = 0; sig < sgh->init->sig_cnt; sig++) {
        Signature *s = sgh->init->match_array[sig];
        if (s == NULL)
            continue;
        SCLogDebug("checking sid %u for non-prefilter", s->id);
        if (s->init_data->mpm_sm != NULL && (s->flags & SIG_FLAG_MPM_NEG) == 0)
            continue;
        if (s->init_data->prefilter_sm != NULL)
            continue;
        if ((s->flags & (SIG_FLAG_PREFILTER | SIG_FLAG_MPM_NEG)) == SIG_FLAG_PREFILTER)
            continue;
        SCLogDebug("setting up sid %u for non-prefilter", s->id);
 
        uint8_t frame_type = 0; /**< only a single type per rule */
        bool tx_non_pf = false;
        bool frame_non_pf = false;
        bool pkt_non_pf = false;
 
        if (s->init_data->hook.type == SIGNATURE_HOOK_TYPE_PKT &&
                s->init_data->hook.t.pkt.ph == SIGNATURE_HOOK_PKT_FLOW_START) {
            // TODO code duplication with regular pkt case below
 
            /* for pkt non prefilter, we have some space in the structure,
             * so we can squeeze another filter */
            uint8_t type;
            uint16_t value;
            if ((s->flags & SIG_FLAG_DSIZE) && s->dsize_mode == DETECT_UINT_EQ) {
                SCLogDebug("dsize extra match");
                type = 2;
                value = s->dsize_low;
            } else if (s->dp != NULL && s->dp->next == NULL && s->dp->port == s->dp->port2) {
                type = 1;
                value = s->dp->port;
            } else {
                type = 0;
                value = s->alproto;
            }
            pkt_hook_flow_start_non_pf_array[pkt_hook_flow_start_non_pf_array_size].sid = s->num;
            pkt_hook_flow_start_non_pf_array[pkt_hook_flow_start_non_pf_array_size].value = value;
            pkt_hook_flow_start_non_pf_array[pkt_hook_flow_start_non_pf_array_size].type = type;
            pkt_hook_flow_start_non_pf_array[pkt_hook_flow_start_non_pf_array_size].pkt.sig_mask =
                    s->mask;
            pkt_hook_flow_start_non_pf_array_size++;
 
            if (pkt_hook_flow_start_mask_init) {
                pkt_hook_flow_start_mask &= s->mask;
            } else {
                pkt_hook_flow_start_mask = s->mask;
                pkt_hook_flow_start_mask_init = true;
            }
 
            SCLogDebug("flow_start hook");
            continue; // done for this sig
        }
 
        for (uint32_t x = 0; x < s->init_data->buffer_index; x++) {
            const int list_id = s->init_data->buffers[x].id;
            const DetectBufferType *buf = DetectEngineBufferTypeGetById(de_ctx, list_id);
            if (buf == NULL)
                continue;
            /* for now, exclude app-layer-events, as they are not tied to a specific
             * progress value like other keywords. */
            SCLogDebug("list_id %d buf %p", list_id, buf);
            if (list_id == app_events_list_id)
                continue;
            if (buf->packet) {
                SCLogDebug("packet buf");
                /* packet is handled below */
                pkt_non_pf = true;
            } else if (buf->frame) {
                for (DetectEngineFrameInspectionEngine *f = de_ctx->frame_inspect_engines;
                        f != NULL; f = f->next) {
                    if (!((((s->flags & SIG_FLAG_TOSERVER) != 0 && f->dir == 0) ||
                                  ((s->flags & SIG_FLAG_TOCLIENT) != 0 && f->dir == 1)) &&
                                list_id == (int)f->sm_list &&
                                AppProtoEquals(s->alproto, f->alproto)))
                        continue;
 
                    SCLogDebug("frame '%s' type %u", buf->name, f->type);
                    frame_type = f->type;
                    frame_non_pf = true;
 
                    frame_non_pf_array[frame_non_pf_array_size].sid = s->num;
                    frame_non_pf_array[frame_non_pf_array_size].value = s->alproto;
                    frame_non_pf_array[frame_non_pf_array_size].frame.type = frame_type;
                    frame_non_pf_array_size++;
                    break;
                }
 
            } else {
                SCLogDebug("x %u list_id %d", x, list_id);
                for (DetectEngineAppInspectionEngine *app = de_ctx->app_inspect_engines;
                        app != NULL; app = app->next) {
                    SCLogDebug("app %p proto %s list_d %d sig dir %0x", app,
                            AppProtoToString(app->alproto), app->sm_list,
                            s->flags & (SIG_FLAG_TOSERVER | SIG_FLAG_TOCLIENT));
 
                    /* skip if:
                     * - not in our dir
                     * - not our list
                     * - app proto mismatch. Both sig and app can have proto or unknown */
                    if (!((((s->flags & SIG_FLAG_TOSERVER) != 0 && app->dir == 0) ||
                                  ((s->flags & SIG_FLAG_TOCLIENT) != 0 && app->dir == 1)) &&
                                list_id == (int)app->sm_list &&
                                (s->alproto == ALPROTO_UNKNOWN || app->alproto == ALPROTO_UNKNOWN ||
                                        AppProtoEquals(s->alproto, app->alproto))))
                        continue;
 
                    int sig_list = 0;
                    if (list_id == app_state_list_id)
                        sig_list = app_state_list_id;
                    if (TxNonPFAddSig(de_ctx, tx_engines_hash, app->alproto, app->dir,
                                app->progress, sig_list, buf->name, s) != 0) {
                        goto error;
                    }
                    tx_non_pf = true;
                }
            }
        }
        /* handle hook only rules */
        if (!tx_non_pf && s->init_data->hook.type == SIGNATURE_HOOK_TYPE_APP) {
            const int dir = (s->flags & SIG_FLAG_TOSERVER) ? 0 : 1;
            const char *pname = AppLayerParserGetStateNameById(IPPROTO_TCP, // TODO
                    s->alproto, s->init_data->hook.t.app.app_progress,
                    dir == 0 ? STREAM_TOSERVER : STREAM_TOCLIENT);
 
            if (TxNonPFAddSig(de_ctx, tx_engines_hash, s->alproto, dir,
                        (int16_t)s->init_data->hook.t.app.app_progress, s->init_data->hook.sm_list,
                        pname, s) != 0) {
                goto error;
            }
            tx_non_pf = true;
        }
        /* mark as prefiltered as the sig is now part of a engine */
        // s->flags |= SIG_FLAG_PREFILTER;
        //  TODO doesn't work for sigs that are in multiple sgh's
 
        /* default to pkt if there was no tx or frame match */
        if (!(tx_non_pf || frame_non_pf)) {
            if (!pkt_non_pf) {
                SCLogDebug("not frame, not tx, so pkt");
            }
            pkt_non_pf = true;
        }
 
        SCLogDebug("setting up sid %u for non-prefilter: %s", s->id,
                tx_non_pf ? "tx engine" : (frame_non_pf ? "frame engine" : "pkt engine"));
 
        if (pkt_non_pf) {
            /* for pkt non prefilter, we have some space in the structure,
             * so we can squeeze another filter */
            uint8_t type;
            uint16_t value;
            if ((s->flags & SIG_FLAG_DSIZE) && s->dsize_mode == DETECT_UINT_EQ) {
                SCLogDebug("dsize extra match");
                type = 2;
                value = s->dsize_low;
#ifdef NONPF_PKT_STATS
                nonpf_pkt_dsize++;
#endif
            } else if (s->dp != NULL && s->dp->next == NULL && s->dp->port == s->dp->port2) {
                type = 1;
                value = s->dp->port;
#ifdef NONPF_PKT_STATS
                nonpf_pkt_dport++;
#endif
            } else {
                type = 0;
                value = s->alproto;
#ifdef NONPF_PKT_STATS
                nonpf_pkt_alproto++;
#endif
            }
 
            pkt_non_pf_array[pkt_non_pf_array_size].sid = s->num;
            pkt_non_pf_array[pkt_non_pf_array_size].value = value;
            pkt_non_pf_array[pkt_non_pf_array_size].type = type;
            pkt_non_pf_array[pkt_non_pf_array_size].pkt.sig_mask = s->mask;
            pkt_non_pf_array_size++;
 
            if (pkt_mask_init) {
                pkt_mask &= s->mask;
            } else {
                pkt_mask = s->mask;
                pkt_mask_init = true;
            }
        }
    }
 
    /* for each unique sig set, add an engine */
    for (HashListTableBucket *b = HashListTableGetListHead(tx_engines_hash); b != NULL;
            b = HashListTableGetListNext(b)) {
        struct TxNonPFData *t = HashListTableGetListData(b);
        SCLogDebug("%s engine for %s hook %d has %u non-pf sigs",
                t->dir == 0 ? "toserver" : "toclient", AppProtoToString(t->alproto), t->progress,
                t->sigs_cnt);
 
        if (((sgh->init->direction & SIG_FLAG_TOSERVER) && t->dir == 1) ||
                ((sgh->init->direction & SIG_FLAG_TOCLIENT) && t->dir == 0)) {
            SCLogDebug("skipped");
            continue;
        }
 
        /* register special progress value to indicate we need to run it all the time */
        int engine_progress = t->progress;
        if (t->sig_list == app_state_list_id) {
            SCLogDebug("engine %s for state list", t->engine_name);
            engine_progress = -1;
        }
 
        struct PrefilterNonPFDataTx *data =
                SCCalloc(1, sizeof(*data) + t->sigs_cnt * sizeof(data->array[0]));
        if (data == NULL)
            goto error;
        data->size = t->sigs_cnt;
        for (uint32_t i = 0; i < t->sigs_cnt; i++) {
            data->array[i] = t->sigs[i].sid;
        }
        if (PrefilterAppendTxEngine(de_ctx, sgh, PrefilterTxNonPF, t->alproto, engine_progress,
                    (void *)data, PrefilterNonPFDataFree, t->engine_name) < 0) {
            SCFree(data);
            goto error;
        }
    }
    HashListTableFree(tx_engines_hash);
    tx_engines_hash = NULL;
 
    if (pkt_non_pf_array_size) {
        struct PrefilterNonPFData *data =
                SCCalloc(1, sizeof(*data) + pkt_non_pf_array_size * sizeof(data->array[0]));
        if (data == NULL)
            goto error;
        data->size = pkt_non_pf_array_size;
        memcpy((uint8_t *)&data->array, pkt_non_pf_array,
                pkt_non_pf_array_size * sizeof(data->array[0]));
        enum SignatureHookPkt hook = SIGNATURE_HOOK_PKT_NOT_SET; // TODO review
        if (PrefilterAppendEngine(de_ctx, sgh, PrefilterPktNonPF, pkt_mask, hook, (void *)data,
                    PrefilterNonPFDataFree, "packet:non_pf") < 0) {
            SCFree(data);
            goto error;
        }
    }
    if (pkt_hook_flow_start_non_pf_array_size) {
        struct PrefilterNonPFData *data = SCCalloc(
                1, sizeof(*data) + pkt_hook_flow_start_non_pf_array_size * sizeof(data->array[0]));
        if (data == NULL)
            goto error;
        data->size = pkt_hook_flow_start_non_pf_array_size;
        memcpy((uint8_t *)&data->array, pkt_hook_flow_start_non_pf_array,
                pkt_hook_flow_start_non_pf_array_size * sizeof(data->array[0]));
        SCLogDebug("packet:flow_start:non_pf added with %u rules", data->size);
        enum SignatureHookPkt hook = SIGNATURE_HOOK_PKT_FLOW_START;
        if (PrefilterAppendEngine(de_ctx, sgh,
                    PrefilterPktNonPFHookFlowStart, // TODO no longer needed to have a dedicated
                                                    // callback
                    pkt_hook_flow_start_mask, hook, (void *)data, PrefilterNonPFDataFree,
                    "packet:flow_start:non_pf") < 0) {
            SCFree(data);
            goto error;
        }
    }
    if (frame_non_pf_array_size) {
        SCLogDebug("%u frame non-pf sigs", frame_non_pf_array_size);
        struct PrefilterNonPFData *data =
                SCCalloc(1, sizeof(*data) + frame_non_pf_array_size * sizeof(data->array[0]));
        if (data == NULL)
            goto error;
        data->size = frame_non_pf_array_size;
        memcpy((uint8_t *)&data->array, frame_non_pf_array,
                frame_non_pf_array_size * sizeof(data->array[0]));
        if (PrefilterAppendFrameEngine(de_ctx, sgh, PrefilterFrameNonPF, ALPROTO_UNKNOWN,
                    FRAME_ANY_TYPE, (void *)data, PrefilterNonPFDataFree, "frame:non_pf") < 0) {
            SCFree(data);
            goto error;
        }
    }
 
    SCFree(pkt_hook_flow_start_non_pf_array);
    pkt_hook_flow_start_non_pf_array = NULL;
    SCFree(pkt_non_pf_array);
    pkt_non_pf_array = NULL;
    SCFree(frame_non_pf_array);
    frame_non_pf_array = NULL;
    return 0;
 
error:
    if (tx_engines_hash) {
        HashListTableFree(tx_engines_hash);
    }
    SCFree(pkt_hook_flow_start_non_pf_array);
    SCFree(pkt_non_pf_array);
    SCFree(frame_non_pf_array);
    return -1;
}
 
int PrefilterSetupRuleGroup(DetectEngineCtx *de_ctx, SigGroupHead *sgh)
{
    int r = PatternMatchPrepareGroup(de_ctx, sgh);
    if (r != 0) {
        FatalError("failed to set up pattern matching");
    }
 
    /* set up engines if needed - when prefilter is set to auto we run
     * all engines, otherwise only those that have been forced by the
     * prefilter keyword. */
    const enum DetectEnginePrefilterSetting setting = de_ctx->prefilter_setting;
    for (int i = 0; i < DETECT_TBLSIZE; i++) {
        if (sigmatch_table[i].SetupPrefilter != NULL &&
                (setting == DETECT_PREFILTER_AUTO || de_ctx->sm_types_prefilter[i])) {
            sigmatch_table[i].SetupPrefilter(de_ctx, sgh);
        }
    }
 
    if (SetupNonPrefilter(de_ctx, sgh) != 0) {
        return -1;
    }
 
    /* we have lists of engines in sgh->init now. Lets setup the
     * match arrays */
    PrefilterEngineList *el;
    if (sgh->init->pkt_engines != NULL) {
        uint32_t cnt = 0;
        for (el = sgh->init->pkt_engines ; el != NULL; el = el->next) {
            cnt++;
        }
        sgh->pkt_engines = SCMallocAligned(cnt * sizeof(PrefilterEngine), CLS);
        if (sgh->pkt_engines == NULL) {
            return -1;
        }
        memset(sgh->pkt_engines, 0x00, (cnt * sizeof(PrefilterEngine)));
 
        PrefilterEngine *e = sgh->pkt_engines;
        for (el = sgh->init->pkt_engines ; el != NULL; el = el->next) {
            e->local_id = el->id;
            e->cb.Prefilter = el->Prefilter;
            e->ctx.pkt.mask = el->pkt_mask;
            // TODO right now we represent the hook in a u8 in the prefilter engine for space
            // reasons.
            BUG_ON(el->pkt_hook >= 8);
            e->ctx.pkt.hook = (uint8_t)el->pkt_hook;
            e->pectx = el->pectx;
            el->pectx = NULL; // e now owns the ctx
            e->gid = el->gid;
            if (el->next == NULL) {
                e->is_last = true;
            }
            e++;
        }
    }
    if (sgh->init->payload_engines != NULL) {
        uint32_t cnt = 0;
        for (el = sgh->init->payload_engines ; el != NULL; el = el->next) {
            cnt++;
        }
        sgh->payload_engines = SCMallocAligned(cnt * sizeof(PrefilterEngine), CLS);
        if (sgh->payload_engines == NULL) {
            return -1;
        }
        memset(sgh->payload_engines, 0x00, (cnt * sizeof(PrefilterEngine)));
 
        PrefilterEngine *e = sgh->payload_engines;
        for (el = sgh->init->payload_engines ; el != NULL; el = el->next) {
            e->local_id = el->id;
            e->cb.Prefilter = el->Prefilter;
            e->ctx.pkt.mask = el->pkt_mask;
            // TODO right now we represent the hook in a u8 in the prefilter engine for space
            // reasons.
            BUG_ON(el->pkt_hook >= 8);
            e->ctx.pkt.hook = (uint8_t)el->pkt_hook;
            e->pectx = el->pectx;
            el->pectx = NULL; // e now owns the ctx
            e->gid = el->gid;
            if (el->next == NULL) {
                e->is_last = true;
            }
            e++;
        }
    }
    if (sgh->init->tx_engines != NULL) {
        uint32_t cnt = 0;
        for (el = sgh->init->tx_engines ; el != NULL; el = el->next) {
            cnt++;
        }
        sgh->tx_engines = SCMallocAligned(cnt * sizeof(PrefilterEngine), CLS);
        if (sgh->tx_engines == NULL) {
            return -1;
        }
        memset(sgh->tx_engines, 0x00, (cnt * sizeof(PrefilterEngine)));
 
        uint16_t local_id = 0;
        PrefilterEngine *e = sgh->tx_engines;
        for (el = sgh->init->tx_engines ; el != NULL; el = el->next) {
            e->local_id = local_id++;
            e->alproto = el->alproto;
            e->ctx.tx_min_progress = el->tx_min_progress;
            e->cb.PrefilterTx = el->PrefilterTx;
            e->pectx = el->pectx;
            el->pectx = NULL; // e now owns the ctx
            e->gid = el->gid;
            e++;
        }
 
        /* sort by tx_min_progress, then alproto, then local_id */
        qsort(sgh->tx_engines, local_id, sizeof(PrefilterEngine),
                PrefilterSetupRuleGroupSortHelper);
        sgh->tx_engines[local_id - 1].is_last = true;
        sgh->tx_engines[local_id - 1].is_last_for_progress = true;
 
        PrefilterEngine *engine;
 
        /* per alproto to set is_last_for_progress per alproto because the inspect
         * loop skips over engines that are not the correct alproto */
        for (AppProto a = ALPROTO_FAILED + 1; a < g_alproto_max; a++) {
            int last_tx_progress = 0;
            bool last_tx_progress_set = false;
            PrefilterEngine *prev_engine = NULL;
            engine = sgh->tx_engines;
            do {
                if (engine->ctx.tx_min_progress != -1)
                    BUG_ON(engine->ctx.tx_min_progress < last_tx_progress);
                if (engine->alproto == a) {
                    if (last_tx_progress_set && engine->ctx.tx_min_progress > last_tx_progress) {
                        if (prev_engine) {
                            prev_engine->is_last_for_progress = true;
                        }
                    }
 
                    last_tx_progress_set = true;
                    prev_engine = engine;
                } else {
                    if (prev_engine) {
                        prev_engine->is_last_for_progress = true;
                    }
                }
                last_tx_progress = engine->ctx.tx_min_progress;
                if (engine->is_last)
                    break;
                engine++;
            } while (1);
        }
#ifdef DEBUG
        SCLogDebug("sgh %p", sgh);
        engine = sgh->tx_engines;
        do {
            SCLogDebug("engine: gid %u alproto %s tx_min_progress %d is_last %s "
                       "is_last_for_progress %s",
                    engine->gid, AppProtoToString(engine->alproto), engine->ctx.tx_min_progress,
                    engine->is_last ? "true" : "false",
                    engine->is_last_for_progress ? "true" : "false");
            if (engine->is_last)
                break;
            engine++;
        } while (1);
#endif
    }
    if (sgh->init->frame_engines != NULL) {
        uint32_t cnt = 0;
        for (el = sgh->init->frame_engines; el != NULL; el = el->next) {
            cnt++;
        }
        sgh->frame_engines = SCMallocAligned(cnt * sizeof(PrefilterEngine), CLS);
        if (sgh->frame_engines == NULL) {
            return -1;
        }
        memset(sgh->frame_engines, 0x00, (cnt * sizeof(PrefilterEngine)));
 
        PrefilterEngine *e = sgh->frame_engines;
        for (el = sgh->init->frame_engines; el != NULL; el = el->next) {
            e->local_id = el->id;
            e->ctx.frame_type = el->frame_type;
            e->cb.PrefilterFrame = el->PrefilterFrame;
            e->alproto = el->alproto;
            e->pectx = el->pectx;
            el->pectx = NULL; // e now owns the ctx
            e->gid = el->gid;
            if (el->next == NULL) {
                e->is_last = true;
            }
            e++;
        }
    }
 
    if (sgh->init->post_rule_match_engines != NULL) {
        uint32_t cnt = 0;
        for (el = sgh->init->post_rule_match_engines; el != NULL; el = el->next) {
            cnt++;
        }
        sgh->post_rule_match_engines = SCMallocAligned(cnt * sizeof(PrefilterEngine), CLS);
        if (sgh->post_rule_match_engines == NULL) {
            return -1;
        }
        memset(sgh->post_rule_match_engines, 0x00, (cnt * sizeof(PrefilterEngine)));
 
        uint16_t local_id = 0;
        PrefilterEngine *e = sgh->post_rule_match_engines;
        for (el = sgh->init->post_rule_match_engines; el != NULL; el = el->next) {
            e->local_id = local_id++;
            e->cb.PrefilterPostRule = el->PrefilterPostRule;
            e->pectx = el->pectx;
            el->pectx = NULL; // e now owns the ctx
            e->gid = el->gid;
            e->is_last = (el->next == NULL);
            e++;
        }
        SCLogDebug("sgh %p max local_id %u", sgh, local_id);
    }
 
    return 0;
}
 
/* hash table for assigning a unique id to each engine type. */
 
static uint32_t PrefilterStoreHashFunc(HashListTable *ht, void *data, uint16_t datalen)
{
    PrefilterStore *ctx = data;
 
    uint32_t hash = strlen(ctx->name);
 
    for (size_t u = 0; u < strlen(ctx->name); u++) {
        hash += ctx->name[u];
    }
 
    hash %= ht->array_size;
    return hash;
}
 
static char PrefilterStoreCompareFunc(void *data1, uint16_t len1,
                                      void *data2, uint16_t len2)
{
    PrefilterStore *ctx1 = data1;
    PrefilterStore *ctx2 = data2;
    return (strcmp(ctx1->name, ctx2->name) == 0);
}
 
static void PrefilterStoreFreeFunc(void *ptr)
{
    SCFree(ptr);
}
 
void PrefilterDeinit(DetectEngineCtx *de_ctx)
{
    if (de_ctx->prefilter_hash_table != NULL) {
        HashListTableFree(de_ctx->prefilter_hash_table);
    }
}
 
void PrefilterInit(DetectEngineCtx *de_ctx)
{
    BUG_ON(de_ctx->prefilter_hash_table != NULL);
 
    de_ctx->prefilter_hash_table = HashListTableInit(256,
            PrefilterStoreHashFunc,
            PrefilterStoreCompareFunc,
            PrefilterStoreFreeFunc);
    BUG_ON(de_ctx->prefilter_hash_table == NULL);
}
 
static int PrefilterStoreGetId(DetectEngineCtx *de_ctx,
        const char *name, void (*FreeFunc)(void *))
{
    PrefilterStore ctx = { name, FreeFunc, 0 };
 
    BUG_ON(de_ctx->prefilter_hash_table == NULL);
 
    SCLogDebug("looking up %s", name);
 
    PrefilterStore *rctx = HashListTableLookup(de_ctx->prefilter_hash_table, (void *)&ctx, 0);
    if (rctx != NULL) {
        return rctx->id;
    }
 
    PrefilterStore *actx = SCCalloc(1, sizeof(*actx));
    if (actx == NULL) {
        return -1;
    }
 
    actx->name = name;
    actx->FreeFunc = FreeFunc;
    actx->id = de_ctx->prefilter_id++;
    SCLogDebug("prefilter engine %s has profile id %u", actx->name, actx->id);
 
    int ret = HashListTableAdd(de_ctx->prefilter_hash_table, actx, 0);
    if (ret != 0) {
        SCFree(actx);
        return -1;
    }
 
    int r = actx->id;
    return r;
}
 
/** \warning slow */
static const PrefilterStore *PrefilterStoreGetStore(const DetectEngineCtx *de_ctx,
        const uint32_t id)
{
 
    const PrefilterStore *store = NULL;
    if (de_ctx->prefilter_hash_table != NULL) {
        HashListTableBucket *hb = HashListTableGetListHead(de_ctx->prefilter_hash_table);
        for ( ; hb != NULL; hb = HashListTableGetListNext(hb)) {
            PrefilterStore *ctx = HashListTableGetListData(hb);
            if (ctx->id == id) {
                store = ctx;
                break;
            }
        }
    }
    return store;
}
 
#ifdef PROFILING
const char *PrefilterStoreGetName(const uint32_t id)
{
    return NULL;
}
#endif
 
#include "util-print.h"
 
typedef struct PrefilterMpmCtx {
    int list_id;
    InspectionBufferGetDataPtr GetData;
    const MpmCtx *mpm_ctx;
    const DetectEngineTransforms *transforms;
} PrefilterMpmCtx;
 
/** \brief Generic Mpm prefilter callback
 *
 *  \param det_ctx detection engine thread ctx
 *  \param p packet to inspect
 *  \param f flow to inspect
 *  \param txv tx to inspect
 *  \param pectx inspection context
 */
static void PrefilterMpm(DetectEngineThreadCtx *det_ctx, const void *pectx, Packet *p, Flow *f,
        void *txv, const uint64_t idx, const AppLayerTxData *_txd, const uint8_t flags)
{
    SCEnter();
 
    const PrefilterMpmCtx *ctx = (const PrefilterMpmCtx *)pectx;
    const MpmCtx *mpm_ctx = ctx->mpm_ctx;
    SCLogDebug("running on list %d", ctx->list_id);
 
    InspectionBuffer *buffer = ctx->GetData(det_ctx, ctx->transforms,
            f, flags, txv, ctx->list_id);
    if (buffer == NULL)
        return;
 
    const uint32_t data_len = buffer->inspect_len;
    const uint8_t *data = buffer->inspect;
 
    SCLogDebug("mpm'ing buffer:");
    //PrintRawDataFp(stdout, data, data_len);
 
    if (data != NULL && data_len >= mpm_ctx->minlen) {
        (void)mpm_table[mpm_ctx->mpm_type].Search(
                mpm_ctx, &det_ctx->mtc, &det_ctx->pmq, data, data_len);
        PREFILTER_PROFILING_ADD_BYTES(det_ctx, data_len);
    }
}
 
static void PrefilterGenericMpmFree(void *ptr)
{
    SCFree(ptr);
}
 
int PrefilterGenericMpmRegister(DetectEngineCtx *de_ctx, SigGroupHead *sgh, MpmCtx *mpm_ctx,
        const DetectBufferMpmRegistry *mpm_reg, int list_id)
{
    SCEnter();
    PrefilterMpmCtx *pectx = SCCalloc(1, sizeof(*pectx));
    if (pectx == NULL)
        return -1;
    pectx->list_id = list_id;
    pectx->GetData = mpm_reg->app_v2.GetData;
    pectx->mpm_ctx = mpm_ctx;
    pectx->transforms = &mpm_reg->transforms;
 
    int r = PrefilterAppendTxEngine(de_ctx, sgh, PrefilterMpm,
        mpm_reg->app_v2.alproto, mpm_reg->app_v2.tx_min_progress,
        pectx, PrefilterGenericMpmFree, mpm_reg->pname);
    if (r != 0) {
        SCFree(pectx);
    }
    return r;
}
 
static void PrefilterMultiGenericMpmFree(void *ptr)
{
    // PrefilterMpmListId
    SCFree(ptr);
}
 
static void PrefilterMultiMpm(DetectEngineThreadCtx *det_ctx, const void *pectx, Packet *p, Flow *f,
        void *txv, const uint64_t idx, const AppLayerTxData *_txd, const uint8_t flags)
{
    SCEnter();
 
    const PrefilterMpmListId *ctx = (const PrefilterMpmListId *)pectx;
    const MpmCtx *mpm_ctx = ctx->mpm_ctx;
    SCLogDebug("running on list %d", ctx->list_id);
    uint32_t local_id = 0;
 
    do {
        // loop until we get a NULL
        InspectionBuffer *buffer = DetectGetMultiData(
                det_ctx, ctx->transforms, f, flags, txv, ctx->list_id, local_id, ctx->GetData);
        if (buffer == NULL)
            break;
 
        if (buffer->inspect_len >= mpm_ctx->minlen) {
            (void)mpm_table[mpm_ctx->mpm_type].Search(
                    mpm_ctx, &det_ctx->mtc, &det_ctx->pmq, buffer->inspect, buffer->inspect_len);
            PREFILTER_PROFILING_ADD_BYTES(det_ctx, buffer->inspect_len);
        }
 
        local_id++;
    } while (1);
}
 
int PrefilterMultiGenericMpmRegister(DetectEngineCtx *de_ctx, SigGroupHead *sgh, MpmCtx *mpm_ctx,
        const DetectBufferMpmRegistry *mpm_reg, int list_id)
{
    SCEnter();
    PrefilterMpmListId *pectx = SCCalloc(1, sizeof(*pectx));
    if (pectx == NULL)
        return -1;
    pectx->list_id = list_id;
    pectx->GetData = mpm_reg->app_v2.GetMultiData;
    pectx->mpm_ctx = mpm_ctx;
    pectx->transforms = &mpm_reg->transforms;
 
    int r = PrefilterAppendTxEngine(de_ctx, sgh, PrefilterMultiMpm, mpm_reg->app_v2.alproto,
            mpm_reg->app_v2.tx_min_progress, pectx, PrefilterMultiGenericMpmFree, mpm_reg->pname);
    if (r != 0) {
        SCFree(pectx);
    }
    return r;
}
 
/* generic mpm for pkt engines */
 
typedef struct PrefilterMpmPktCtx {
    int list_id;
    InspectionBufferGetPktDataPtr GetData;
    const MpmCtx *mpm_ctx;
    const DetectEngineTransforms *transforms;
} PrefilterMpmPktCtx;
 
/** \brief Generic Mpm prefilter callback
 *
 *  \param det_ctx detection engine thread ctx
 *  \param p packet to inspect
 *  \param f flow to inspect
 *  \param txv tx to inspect
 *  \param pectx inspection context
 */
static void PrefilterMpmPkt(DetectEngineThreadCtx *det_ctx,
        Packet *p, const void *pectx)
{
    SCEnter();
 
    const PrefilterMpmPktCtx *ctx = (const PrefilterMpmPktCtx *)pectx;
    const MpmCtx *mpm_ctx = ctx->mpm_ctx;
    SCLogDebug("running on list %d", ctx->list_id);
 
    InspectionBuffer *buffer = ctx->GetData(det_ctx, ctx->transforms,
            p, ctx->list_id);
    if (buffer == NULL)
        return;
 
    const uint32_t data_len = buffer->inspect_len;
    const uint8_t *data = buffer->inspect;
 
    SCLogDebug("mpm'ing buffer:");
    //PrintRawDataFp(stdout, data, data_len);
 
    if (data != NULL && data_len >= mpm_ctx->minlen) {
        (void)mpm_table[mpm_ctx->mpm_type].Search(
                mpm_ctx, &det_ctx->mtc, &det_ctx->pmq, data, data_len);
        PREFILTER_PROFILING_ADD_BYTES(det_ctx, data_len);
    }
}
 
static void PrefilterMpmPktFree(void *ptr)
{
    SCFree(ptr);
}
 
int PrefilterGenericMpmPktRegister(DetectEngineCtx *de_ctx, SigGroupHead *sgh, MpmCtx *mpm_ctx,
        const DetectBufferMpmRegistry *mpm_reg, int list_id)
{
    SCEnter();
    PrefilterMpmPktCtx *pectx = SCCalloc(1, sizeof(*pectx));
    if (pectx == NULL)
        return -1;
    pectx->list_id = list_id;
    pectx->GetData = mpm_reg->pkt_v1.GetData;
    pectx->mpm_ctx = mpm_ctx;
    pectx->transforms = &mpm_reg->transforms;
 
    enum SignatureHookPkt hook = SIGNATURE_HOOK_PKT_NOT_SET; // TODO review
    int r = PrefilterAppendEngine(
            de_ctx, sgh, PrefilterMpmPkt, 0, hook, pectx, PrefilterMpmPktFree, mpm_reg->pname);
    if (r != 0) {
        SCFree(pectx);
    }
    return r;
}
 
#define QUEUE_STEP 16
 
void PostRuleMatchWorkQueueAppend(
        DetectEngineThreadCtx *det_ctx, const Signature *s, const int type, const uint32_t value)
{
    if (det_ctx->post_rule_work_queue.q == NULL) {
        det_ctx->post_rule_work_queue.q =
                SCCalloc(1, sizeof(PostRuleMatchWorkQueueItem) * QUEUE_STEP);
        if (det_ctx->post_rule_work_queue.q == NULL) {
            DetectEngineSetEvent(det_ctx, DETECT_EVENT_POST_MATCH_QUEUE_FAILED);
            return;
        }
        det_ctx->post_rule_work_queue.size = QUEUE_STEP;
    } else if (det_ctx->post_rule_work_queue.len == det_ctx->post_rule_work_queue.size) {
        void *ptr = SCRealloc(
                det_ctx->post_rule_work_queue.q, (det_ctx->post_rule_work_queue.size + QUEUE_STEP) *
                                                         sizeof(PostRuleMatchWorkQueueItem));
        if (ptr == NULL) {
            DetectEngineSetEvent(det_ctx, DETECT_EVENT_POST_MATCH_QUEUE_FAILED);
            return;
        }
        det_ctx->post_rule_work_queue.q = ptr;
        det_ctx->post_rule_work_queue.size += QUEUE_STEP;
    }
    det_ctx->post_rule_work_queue.q[det_ctx->post_rule_work_queue.len].sm_type = type;
    det_ctx->post_rule_work_queue.q[det_ctx->post_rule_work_queue.len].value = value;
#ifdef DEBUG
    det_ctx->post_rule_work_queue.q[det_ctx->post_rule_work_queue.len].id = s->num;
#endif
    det_ctx->post_rule_work_queue.len++;
    SCLogDebug("det_ctx->post_rule_work_queue.len %u", det_ctx->post_rule_work_queue.len);
}