/*
 * daemon/cachedump.c - dump the cache to text format.
 *
 * Copyright (c) 2008, NLnet Labs. All rights reserved.
 *
 * This software is open source.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 * Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 * 
 * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 * 
 * Neither the name of the NLNET LABS nor the names of its contributors may
 * be used to endorse or promote products derived from this software without
 * specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * \file
 *
 * This file contains functions to read and write the cache(s)
 * to text format.
 */
#include "config.h"
#include <openssl/ssl.h>
#include "daemon/cachedump.h"
#include "daemon/remote.h"
#include "daemon/worker.h"
#include "services/cache/rrset.h"
#include "services/cache/dns.h"
#include "services/cache/infra.h"
#include "services/outside_network.h"
#include "util/data/msgreply.h"
#include "util/regional.h"
#include "util/net_help.h"
#include "util/data/dname.h"
#include "util/config_file.h"
#include "iterator/iterator.h"
#include "iterator/iter_delegpt.h"
#include "iterator/iter_utils.h"
#include "iterator/iter_fwd.h"
#include "iterator/iter_hints.h"
#include "sldns/sbuffer.h"
#include "sldns/wire2str.h"
#include "sldns/str2wire.h"

static void spool_txt_printf(struct config_strlist_head* txt,
        const char* format, ...) ATTR_FORMAT(printf, 2, 3);

/** Append to strlist at end, and log error if out of memory. */
static void
spool_txt_string(struct config_strlist_head* txt, char* str)
{
        if(!cfg_strlist_append(txt, strdup(str))) {
                log_err("out of memory in spool text");
        }
}

/** Spool txt to spool list. */
static void
spool_txt_vmsg(struct config_strlist_head* txt, const char* format,
        va_list args)
{
        char msg[65535];
        vsnprintf(msg, sizeof(msg), format, args);
        spool_txt_string(txt, msg);
}

/** Print item to spool list. On alloc failure the list is as before. */
static void
spool_txt_printf(struct config_strlist_head* txt, const char* format, ...)
{
        va_list args;
        va_start(args, format);
        spool_txt_vmsg(txt, format, args);
        va_end(args);
}

/** dump one rrset zonefile line */
static void
dump_rrset_line(struct config_strlist_head* txt, struct ub_packed_rrset_key* k,
        time_t now, size_t i)
{
        char s[65535];
        if(!packed_rr_to_string(k, i, now, s, sizeof(s))) {
                spool_txt_string(txt, "BADRR\n");
                return;
        }
        spool_txt_string(txt, s);
}

/** dump rrset key and data info */
static void
dump_rrset(struct config_strlist_head* txt, struct ub_packed_rrset_key* k,
        struct packed_rrset_data* d, time_t now)
{
        size_t i;
        /* rd lock held by caller */
        if(!k || !d) return;
        if(k->id == 0) return; /* deleted */
        if(d->ttl < now) return; /* expired */

        /* meta line */
        spool_txt_printf(txt, ";rrset%s " ARG_LL "d %u %u %d %d\n",
                (k->rk.flags & PACKED_RRSET_NSEC_AT_APEX)?" nsec_apex":"",
                (long long)(d->ttl - now),
                (unsigned)d->count, (unsigned)d->rrsig_count,
                (int)d->trust, (int)d->security
                );
        for(i=0; i<d->count + d->rrsig_count; i++) {
                dump_rrset_line(txt, k, now, i);
        }
}

/** Spool strlist to the output. */
static int
spool_strlist(RES* ssl, struct config_strlist* list)
{
        struct config_strlist* s;
        for(s=list; s; s=s->next) {
                if(!ssl_printf(ssl, "%s", s->str))
                        return 0;
        }
        return 1;
}

/** dump lruhash cache and call callback for every item. */
static int
dump_lruhash(struct lruhash* table,
        void (*func)(struct lruhash_entry*, struct config_strlist_head*, void*),
        RES* ssl, void* arg)
{
        int just_started = 1;
        int not_done = 1;
        hashvalue_type hash;
        size_t num = 0; /* number of entries processed. */
        size_t max = 2; /* number of entries after which it unlocks. */
        struct config_strlist_head txt; /* Text strings spooled. */
        memset(&txt, 0, sizeof(txt));

        while(not_done) {
                size_t i; /* hash bin. */
                /* Process a number of items. */
                num = 0;
                lock_quick_lock(&table->lock);
                if(just_started) {
                        i = 0;
                } else {
                        i = hash&table->size_mask;
                }
                while(num < max) {
                        /* Process bin. */
                        int found = 0;
                        size_t num_bin = 0;
                        struct lruhash_bin* bin = &table->array[i];
                        struct lruhash_entry* e;
                        lock_quick_lock(&bin->lock);
                        for(e = bin->overflow_list; e; e = e->overflow_next) {
                                /* Entry e is locked by the func. */
                                func(e, &txt, arg);
                                num_bin++;
                        }
                        lock_quick_unlock(&bin->lock);
                        /* This addition of bin number of entries may take
                         * it over the max. */
                        num += num_bin;

                        /* Move to next bin. */
                        /* Find one with an entry, with a  hash value, so we
                         * can continue from the hash value. The hash value
                         * can be indexed also if the array changes size. */
                        i++;
                        while(i < table->size) {
                                bin = &table->array[i];
                                lock_quick_lock(&bin->lock);
                                if(bin->overflow_list) {
                                        hash = bin->overflow_list->hash;
                                        lock_quick_unlock(&bin->lock);
                                        found = 1;
                                        just_started = 0;
                                        break;
                                }
                                lock_quick_unlock(&bin->lock);
                                i++;
                        }
                        if(!found) {
                                not_done = 0;
                                break;
                        }
                }
                lock_quick_unlock(&table->lock);
                /* Print the spooled items, that are collected while the
                 * locks are locked. The print happens while they are not
                 * locked. */
                if(txt.first) {
                        if(!spool_strlist(ssl, txt.first)) {
                                config_delstrlist(txt.first);
                                return 0;
                        }
                        config_delstrlist(txt.first);
                        memset(&txt, 0, sizeof(txt));
                }
        }
        /* Print the final spooled items. */
        if(txt.first) {
                if(!spool_strlist(ssl, txt.first)) {
                        config_delstrlist(txt.first);
                        return 0;
                }
                config_delstrlist(txt.first);
        }
        return 1;
}

/** dump slabhash cache and call callback for every item. */
static int
dump_slabhash(struct slabhash* sh,
        void (*func)(struct lruhash_entry*, struct config_strlist_head*, void*),
        RES* ssl, void* arg)
{
        /* Process a number of items at a time, then unlock the cache,
         * so that ordinary processing can continue. Keep an iteration marker
         * to continue the loop. That means the cache can change, items
         * could be inserted and deleted. And, for example, the hash table
         * can grow. */
        size_t slab;
        for(slab=0; slab<sh->size; slab++) {
                if(!dump_lruhash(sh->array[slab], func, ssl, arg))
                        return 0;
        }
        return 1;
}

/** Struct for dump information. */
struct dump_info {
        /** The worker. */
        struct worker* worker;
        /** The printout connection. */
        RES* ssl;
};

/** Dump the rrset cache entry */
static void
dump_rrset_entry(struct lruhash_entry* e, struct config_strlist_head* txt,
        void* arg)
{
        struct dump_info* dump_info = (struct dump_info*)arg;
        lock_rw_rdlock(&e->lock);
        dump_rrset(txt, (struct ub_packed_rrset_key*)e->key,
                (struct packed_rrset_data*)e->data,
                *dump_info->worker->env.now);
        lock_rw_unlock(&e->lock);
}

/** dump rrset cache */
static int
dump_rrset_cache(RES* ssl, struct worker* worker)
{
        struct rrset_cache* r = worker->env.rrset_cache;
        struct dump_info dump_info;
        dump_info.worker = worker;
        dump_info.ssl = ssl;
        if(!ssl_printf(ssl, "START_RRSET_CACHE\n")) return 0;
        if(!dump_slabhash(&r->table, &dump_rrset_entry, ssl, &dump_info))
                return 0;
        return ssl_printf(ssl, "END_RRSET_CACHE\n");
}

/** dump message to rrset reference */
static void
dump_msg_ref(struct config_strlist_head* txt, struct ub_packed_rrset_key* k)
{
        char* nm, *tp, *cl;
        nm = sldns_wire2str_dname(k->rk.dname, k->rk.dname_len);
        tp = sldns_wire2str_type(ntohs(k->rk.type));
        cl = sldns_wire2str_class(ntohs(k->rk.rrset_class));
        if(!nm || !cl || !tp) {
                free(nm);
                free(tp);
                free(cl);
                spool_txt_string(txt, "BADREF\n");
                return;
        }
        spool_txt_printf(txt, "%s %s %s %d\n", nm, cl, tp, (int)k->rk.flags);
        free(nm);
        free(tp);
        free(cl);
}

/** dump message entry */
static void
dump_msg(struct config_strlist_head* txt, struct query_info* k,
        struct reply_info* d, time_t now)
{
        size_t i;
        char* nm, *tp, *cl;
        if(!k || !d) return;
        if(d->ttl < now) return; /* expired */

        nm = sldns_wire2str_dname(k->qname, k->qname_len);
        tp = sldns_wire2str_type(k->qtype);
        cl = sldns_wire2str_class(k->qclass);
        if(!nm || !tp || !cl) {
                free(nm);
                free(tp);
                free(cl);
                return; /* skip this entry */
        }
        if(!rrset_array_lock(d->ref, d->rrset_count, now)) {
                /* rrsets have timed out or do not exist */
                free(nm);
                free(tp);
                free(cl);
                return; /* skip this entry */
        }

        /* meta line */
        spool_txt_printf(txt,
                "msg %s %s %s %d %d " ARG_LL "d %d %u %u %u %d %s\n",
                nm, cl, tp,
                (int)d->flags, (int)d->qdcount,
                (long long)(d->ttl-now), (int)d->security,
                (unsigned)d->an_numrrsets,
                (unsigned)d->ns_numrrsets,
                (unsigned)d->ar_numrrsets,
                (int)d->reason_bogus,
                d->reason_bogus_str?d->reason_bogus_str:"");
        free(nm);
        free(tp);
        free(cl);
        
        for(i=0; i<d->rrset_count; i++) {
                dump_msg_ref(txt, d->rrsets[i]);
        }
        rrset_array_unlock(d->ref, d->rrset_count);
}

/** copy msg to worker pad */
static int
copy_msg(struct regional* region, struct lruhash_entry* e, 
        struct query_info** k, struct reply_info** d)
{
        struct reply_info* rep = (struct reply_info*)e->data;
        if(rep->rrset_count > RR_COUNT_MAX)
                return 0; /* to protect against integer overflow */
        *d = (struct reply_info*)regional_alloc_init(region, e->data,
                sizeof(struct reply_info) + 
                sizeof(struct rrset_ref) * (rep->rrset_count-1) +
                sizeof(struct ub_packed_rrset_key*) * rep->rrset_count);
        if(!*d)
                return 0;
        (*d)->rrsets = (struct ub_packed_rrset_key**)(void *)(
                (uint8_t*)(&((*d)->ref[0])) + 
                sizeof(struct rrset_ref) * rep->rrset_count);
        *k = (struct query_info*)regional_alloc_init(region, 
                e->key, sizeof(struct query_info));
        if(!*k)
                return 0;
        (*k)->qname = regional_alloc_init(region, 
                (*k)->qname, (*k)->qname_len);
        return (*k)->qname != NULL;
}

/** Dump the msg entry. */
static void
dump_msg_entry(struct lruhash_entry* e, struct config_strlist_head* txt,
        void* arg)
{
        struct dump_info* dump_info = (struct dump_info*)arg;
        struct query_info* k;
        struct reply_info* d;

        regional_free_all(dump_info->worker->scratchpad);
        /* Make copy of rrset in worker buffer. */
        lock_rw_rdlock(&e->lock);
        if(!copy_msg(dump_info->worker->scratchpad, e, &k, &d)) {
                lock_rw_unlock(&e->lock);
                log_err("out of memory in dump_msg_entry");
                return;
        }
        lock_rw_unlock(&e->lock);
        /* Release lock so we can lookup the rrset references
         * in the rrset cache. */
        dump_msg(txt, k, d, *dump_info->worker->env.now);
}

/** dump msg cache */
static int
dump_msg_cache(RES* ssl, struct worker* worker)
{
        struct dump_info dump_info;
        dump_info.worker = worker;
        dump_info.ssl = ssl;
        if(!ssl_printf(ssl, "START_MSG_CACHE\n")) return 0;
        if(!dump_slabhash(worker->env.msg_cache, &dump_msg_entry, ssl,
                &dump_info))
                return 0;
        return ssl_printf(ssl, "END_MSG_CACHE\n");
}

int
dump_cache(RES* ssl, struct worker* worker)
{
        if(!dump_rrset_cache(ssl, worker))
                return 0;
        if(!dump_msg_cache(ssl, worker))
                return 0;
        return ssl_printf(ssl, "EOF\n");
}

/** read a line from ssl into buffer */
static int
ssl_read_buf(RES* ssl, sldns_buffer* buf)
{
        return ssl_read_line(ssl, (char*)sldns_buffer_begin(buf), 
                sldns_buffer_capacity(buf));
}

/** check fixed text on line */
static int
read_fixed(RES* ssl, sldns_buffer* buf, const char* str)
{
        if(!ssl_read_buf(ssl, buf)) return 0;
        return (strcmp((char*)sldns_buffer_begin(buf), str) == 0);
}

/** load an RR into rrset */
static int
load_rr(RES* ssl, sldns_buffer* buf, struct regional* region,
        struct ub_packed_rrset_key* rk, struct packed_rrset_data* d,
        unsigned int i, int is_rrsig, int* go_on, time_t now)
{
        uint8_t rr[LDNS_RR_BUF_SIZE];
        size_t rr_len = sizeof(rr), dname_len = 0;
        int status;

        /* read the line */
        if(!ssl_read_buf(ssl, buf))
                return 0;
        if(strncmp((char*)sldns_buffer_begin(buf), "BADRR\n", 6) == 0) {
                *go_on = 0;
                return 1;
        }
        status = sldns_str2wire_rr_buf((char*)sldns_buffer_begin(buf), rr,
                &rr_len, &dname_len, 3600, NULL, 0, NULL, 0);
        if(status != 0) {
                log_warn("error cannot parse rr: %s: %s",
                        sldns_get_errorstr_parse(status),
                        (char*)sldns_buffer_begin(buf));
                return 0;
        }
        if(is_rrsig && sldns_wirerr_get_type(rr, rr_len, dname_len)
                != LDNS_RR_TYPE_RRSIG) {
                log_warn("error expected rrsig but got %s",
                        (char*)sldns_buffer_begin(buf));
                return 0;
        }

        /* convert ldns rr into packed_rr */
        d->rr_ttl[i] = (time_t)sldns_wirerr_get_ttl(rr, rr_len, dname_len) + now;
        sldns_buffer_clear(buf);
        d->rr_len[i] = sldns_wirerr_get_rdatalen(rr, rr_len, dname_len)+2;
        d->rr_data[i] = (uint8_t*)regional_alloc_init(region, 
                sldns_wirerr_get_rdatawl(rr, rr_len, dname_len), d->rr_len[i]);
        if(!d->rr_data[i]) {
                log_warn("error out of memory");
                return 0;
        }

        /* if first entry, fill the key structure */
        if(i==0) {
                rk->rk.type = htons(sldns_wirerr_get_type(rr, rr_len, dname_len));
                rk->rk.rrset_class = htons(sldns_wirerr_get_class(rr, rr_len, dname_len));
                rk->rk.dname_len = dname_len;
                rk->rk.dname = regional_alloc_init(region, rr, dname_len);
                if(!rk->rk.dname) {
                        log_warn("error out of memory");
                        return 0;
                }
        }

        return 1;
}

/** move entry into cache */
static int
move_into_cache(struct ub_packed_rrset_key* k, 
        struct packed_rrset_data* d, struct worker* worker)
{
        struct ub_packed_rrset_key* ak;
        struct packed_rrset_data* ad;
        size_t s, i, num = d->count + d->rrsig_count;
        struct rrset_ref ref;
        uint8_t* p;

        ak = alloc_special_obtain(worker->alloc);
        if(!ak) {
                log_warn("error out of memory");
                return 0;
        }
        ak->entry.data = NULL;
        ak->rk = k->rk;
        ak->entry.hash = rrset_key_hash(&k->rk);
        ak->rk.dname = (uint8_t*)memdup(k->rk.dname, k->rk.dname_len);
        if(!ak->rk.dname) {
                log_warn("error out of memory");
                ub_packed_rrset_parsedelete(ak, worker->alloc);
                return 0;
        }
        s = sizeof(*ad) + (sizeof(size_t) + sizeof(uint8_t*) + 
                sizeof(time_t))* num;
        for(i=0; i<num; i++)
                s += d->rr_len[i];
        ad = (struct packed_rrset_data*)malloc(s);
        if(!ad) {
                log_warn("error out of memory");
                ub_packed_rrset_parsedelete(ak, worker->alloc);
                return 0;
        }
        p = (uint8_t*)ad;
        memmove(p, d, sizeof(*ad));
        p += sizeof(*ad);
        memmove(p, &d->rr_len[0], sizeof(size_t)*num);
        p += sizeof(size_t)*num;
        memmove(p, &d->rr_data[0], sizeof(uint8_t*)*num);
        p += sizeof(uint8_t*)*num;
        memmove(p, &d->rr_ttl[0], sizeof(time_t)*num);
        p += sizeof(time_t)*num;
        for(i=0; i<num; i++) {
                memmove(p, d->rr_data[i], d->rr_len[i]);
                p += d->rr_len[i];
        }
        packed_rrset_ptr_fixup(ad);

        ak->entry.data = ad;

        ref.key = ak;
        ref.id = ak->id;
        (void)rrset_cache_update(worker->env.rrset_cache, &ref,
                worker->alloc, *worker->env.now);

        return 1;
}

/** load an rrset entry */
static int
load_rrset(RES* ssl, sldns_buffer* buf, struct worker* worker)
{
        char* s = (char*)sldns_buffer_begin(buf);
        struct regional* region = worker->scratchpad;
        struct ub_packed_rrset_key* rk;
        struct packed_rrset_data* d;
        unsigned int rr_count, rrsig_count, trust, security;
        long long ttl;
        unsigned int i;
        int go_on = 1;
        regional_free_all(region);

        rk = (struct ub_packed_rrset_key*)regional_alloc_zero(region, 
                sizeof(*rk));
        d = (struct packed_rrset_data*)regional_alloc_zero(region, sizeof(*d));
        if(!rk || !d) {
                log_warn("error out of memory");
                return 0;
        }

        if(strncmp(s, ";rrset", 6) != 0) {
                log_warn("error expected ';rrset' but got %s", s);
                return 0;
        }
        s += 6;
        if(strncmp(s, " nsec_apex", 10) == 0) {
                s += 10;
                rk->rk.flags |= PACKED_RRSET_NSEC_AT_APEX;
        }
        if(sscanf(s, " " ARG_LL "d %u %u %u %u", &ttl, &rr_count, &rrsig_count,
                &trust, &security) != 5) {
                log_warn("error bad rrset spec %s", s);
                return 0;
        }
        if(rr_count == 0 && rrsig_count == 0) {
                log_warn("bad rrset without contents");
                return 0;
        }
        if(rr_count > RR_COUNT_MAX || rrsig_count > RR_COUNT_MAX) {
                log_warn("bad rrset with too many rrs");
                return 0;
        }
        d->count = (size_t)rr_count;
        d->rrsig_count = (size_t)rrsig_count;
        d->security = (enum sec_status)security;
        d->trust = (enum rrset_trust)trust;
        d->ttl = (time_t)ttl + *worker->env.now;

        d->rr_len = regional_alloc_zero(region, 
                sizeof(size_t)*(d->count+d->rrsig_count));
        d->rr_ttl = regional_alloc_zero(region, 
                sizeof(time_t)*(d->count+d->rrsig_count));
        d->rr_data = regional_alloc_zero(region, 
                sizeof(uint8_t*)*(d->count+d->rrsig_count));
        if(!d->rr_len || !d->rr_ttl || !d->rr_data) {
                log_warn("error out of memory");
                return 0;
        }
        
        /* read the rr's themselves */
        for(i=0; i<rr_count; i++) {
                if(!load_rr(ssl, buf, region, rk, d, i, 0, 
                        &go_on, *worker->env.now)) {
                        log_warn("could not read rr %u", i);
                        return 0;
                }
        }
        for(i=0; i<rrsig_count; i++) {
                if(!load_rr(ssl, buf, region, rk, d, i+rr_count, 1, 
                        &go_on, *worker->env.now)) {
                        log_warn("could not read rrsig %u", i);
                        return 0;
                }
        }
        if(!go_on) {
                /* skip this entry */
                return 1;
        }

        return move_into_cache(rk, d, worker);
}

/** load rrset cache */
static int
load_rrset_cache(RES* ssl, struct worker* worker)
{
        sldns_buffer* buf = worker->env.scratch_buffer;
        if(!read_fixed(ssl, buf, "START_RRSET_CACHE")) return 0;
        while(ssl_read_buf(ssl, buf) && 
                strcmp((char*)sldns_buffer_begin(buf), "END_RRSET_CACHE")!=0) {
                if(!load_rrset(ssl, buf, worker))
                        return 0;
        }
        return 1;
}

/** read qinfo from next three words */
static char*
load_qinfo(char* str, struct query_info* qinfo, struct regional* region)
{
        /* s is part of the buf */
        char* s = str;
        uint8_t rr[LDNS_RR_BUF_SIZE];
        size_t rr_len = sizeof(rr), dname_len = 0;
        int status;

        /* skip three words */
        s = strchr(str, ' ');
        if(s) s = strchr(s+1, ' ');
        if(s) s = strchr(s+1, ' ');
        if(!s) {
                log_warn("error line too short, %s", str);
                return NULL;
        }
        s[0] = 0;
        s++;

        /* parse them */
        status = sldns_str2wire_rr_question_buf(str, rr, &rr_len, &dname_len,
                NULL, 0, NULL, 0);
        if(status != 0) {
                log_warn("error cannot parse: %s %s",
                        sldns_get_errorstr_parse(status), str);
                return NULL;
        }
        qinfo->qtype = sldns_wirerr_get_type(rr, rr_len, dname_len);
        qinfo->qclass = sldns_wirerr_get_class(rr, rr_len, dname_len);
        qinfo->qname_len = dname_len;
        qinfo->qname = (uint8_t*)regional_alloc_init(region, rr, dname_len);
        qinfo->local_alias = NULL;
        if(!qinfo->qname) {
                log_warn("error out of memory");
                return NULL;
        }

        return s;
}

/** load a msg rrset reference */
static int
load_ref(RES* ssl, sldns_buffer* buf, struct worker* worker, 
        struct regional *region, struct ub_packed_rrset_key** rrset, 
        int* go_on)
{
        char* s = (char*)sldns_buffer_begin(buf);
        struct query_info qinfo;
        unsigned int flags;
        struct ub_packed_rrset_key* k;

        /* read line */
        if(!ssl_read_buf(ssl, buf))
                return 0;
        if(strncmp(s, "BADREF", 6) == 0) {
                *go_on = 0; /* its bad, skip it and skip message */
                return 1;
        }

        s = load_qinfo(s, &qinfo, region);
        if(!s) {
                return 0;
        }
        if(sscanf(s, " %u", &flags) != 1) {
                log_warn("error cannot parse flags: %s", s);
                return 0;
        }

        /* lookup in cache */
        k = rrset_cache_lookup(worker->env.rrset_cache, qinfo.qname,
                qinfo.qname_len, qinfo.qtype, qinfo.qclass,
                (uint32_t)flags, *worker->env.now, 0);
        if(!k) {
                /* not found or expired */
                *go_on = 0;
                return 1;
        }

        /* store in result */
        *rrset = packed_rrset_copy_region(k, region, *worker->env.now);
        lock_rw_unlock(&k->entry.lock);

        return (*rrset != NULL);
}

/** load a msg entry */
static int
load_msg(RES* ssl, sldns_buffer* buf, struct worker* worker)
{
        struct regional* region = worker->scratchpad;
        struct query_info qinf;
        struct reply_info rep;
        char* s = (char*)sldns_buffer_begin(buf);
        unsigned int flags, qdcount, security, an, ns, ar;
        long long ttl;
        size_t i;
        int go_on = 1;
        int ede;
        int consumed = 0;
        char* ede_str = NULL;

        regional_free_all(region);

        if(strncmp(s, "msg ", 4) != 0) {
                log_warn("error expected msg but got %s", s);
                return 0;
        }
        s += 4;
        s = load_qinfo(s, &qinf, region);
        if(!s) {
                return 0;
        }

        /* read remainder of line */
        /* note the last space before any possible EDE text */
        if(sscanf(s, " %u %u " ARG_LL "d %u %u %u %u %d %n", &flags, &qdcount, &ttl,
                &security, &an, &ns, &ar, &ede, &consumed) != 8) {
                log_warn("error cannot parse numbers: %s", s);
                return 0;
        }
        /* there may be EDE text after the numbers */
        if(consumed > 0 && (size_t)consumed < strlen(s))
                ede_str = s + consumed;
        memset(&rep, 0, sizeof(rep));
        rep.flags = (uint16_t)flags;
        rep.qdcount = (uint16_t)qdcount;
        rep.ttl = (time_t)ttl;
        rep.prefetch_ttl = PREFETCH_TTL_CALC(rep.ttl);
        rep.serve_expired_ttl = rep.ttl + SERVE_EXPIRED_TTL;
        rep.security = (enum sec_status)security;
        if(an > RR_COUNT_MAX || ns > RR_COUNT_MAX || ar > RR_COUNT_MAX) {
                log_warn("error too many rrsets");
                return 0; /* protect against integer overflow in alloc */
        }
        rep.an_numrrsets = (size_t)an;
        rep.ns_numrrsets = (size_t)ns;
        rep.ar_numrrsets = (size_t)ar;
        rep.rrset_count = (size_t)an+(size_t)ns+(size_t)ar;
        rep.reason_bogus = (sldns_ede_code)ede;
        rep.reason_bogus_str = ede_str?(char*)regional_strdup(region, ede_str):NULL;
        rep.rrsets = (struct ub_packed_rrset_key**)regional_alloc_zero(
                region, sizeof(struct ub_packed_rrset_key*)*rep.rrset_count);

        /* fill repinfo with references */
        for(i=0; i<rep.rrset_count; i++) {
                if(!load_ref(ssl, buf, worker, region, &rep.rrsets[i], 
                        &go_on)) {
                        return 0;
                }
        }

        if(!go_on) 
                return 1; /* skip this one, not all references satisfied */

        if(!dns_cache_store(&worker->env, &qinf, &rep, 0, 0, 0, NULL, flags,
                *worker->env.now, 1)) {
                log_warn("error out of memory");
                return 0;
        }
        return 1;
}

/** load msg cache */
static int
load_msg_cache(RES* ssl, struct worker* worker)
{
        sldns_buffer* buf = worker->env.scratch_buffer;
        if(!read_fixed(ssl, buf, "START_MSG_CACHE")) return 0;
        while(ssl_read_buf(ssl, buf) && 
                strcmp((char*)sldns_buffer_begin(buf), "END_MSG_CACHE")!=0) {
                if(!load_msg(ssl, buf, worker))
                        return 0;
        }
        return 1;
}

int
load_cache(RES* ssl, struct worker* worker)
{
        if(!load_rrset_cache(ssl, worker))
                return 0;
        if(!load_msg_cache(ssl, worker))
                return 0;
        return read_fixed(ssl, worker->env.scratch_buffer, "EOF");
}

/** print details on a delegation point */
static void
print_dp_details(RES* ssl, struct worker* worker, struct delegpt* dp)
{
        char buf[257];
        struct delegpt_addr* a;
        int lame, dlame, rlame, rto, edns_vs, to, delay,
                tA = 0, tAAAA = 0, tother = 0;
        long long entry_ttl;
        struct rtt_info ri;
        uint8_t edns_lame_known;
        for(a = dp->target_list; a; a = a->next_target) {
                addr_to_str(&a->addr, a->addrlen, buf, sizeof(buf));
                if(!ssl_printf(ssl, "%-16s\t", buf))
                        return;
                if(a->bogus) {
                        if(!ssl_printf(ssl, "Address is BOGUS. ")) 
                                return;
                }
                /* lookup in infra cache */
                delay=0;
                entry_ttl = infra_get_host_rto(worker->env.infra_cache,
                        &a->addr, a->addrlen, dp->name, dp->namelen,
                        &ri, &delay, *worker->env.now, &tA, &tAAAA, &tother);
                if(entry_ttl == -2 && ri.rto >= USEFUL_SERVER_TOP_TIMEOUT) {
                        if(!ssl_printf(ssl, "expired, rto %d msec, tA %d "
                                "tAAAA %d tother %d.\n", ri.rto, tA, tAAAA,
                                tother))
                                return;
                        continue;
                }
                if(entry_ttl == -1 || entry_ttl == -2) {
                        if(!ssl_printf(ssl, "not in infra cache.\n"))
                                return;
                        continue; /* skip stuff not in infra cache */
                }

                /* uses type_A because most often looked up, but other
                 * lameness won't be reported then */
                if(!infra_get_lame_rtt(worker->env.infra_cache, 
                        &a->addr, a->addrlen, dp->name, dp->namelen,
                        LDNS_RR_TYPE_A, &lame, &dlame, &rlame, &rto,
                        *worker->env.now)) {
                        if(!ssl_printf(ssl, "not in infra cache.\n"))
                                return;
                        continue; /* skip stuff not in infra cache */
                }
                if(!ssl_printf(ssl, "%s%s%s%srto %d msec, ttl " ARG_LL "d, "
                        "ping %d var %d rtt %d, tA %d, tAAAA %d, tother %d",
                        lame?"LAME ":"", dlame?"NoDNSSEC ":"",
                        a->lame?"AddrWasParentSide ":"",
                        rlame?"NoAuthButRecursive ":"", rto, entry_ttl,
                        ri.srtt, ri.rttvar, rtt_notimeout(&ri),
                        tA, tAAAA, tother))
                        return;
                if(delay)
                        if(!ssl_printf(ssl, ", probedelay %d", delay))
                                return;
                if(infra_host(worker->env.infra_cache, &a->addr, a->addrlen,
                        dp->name, dp->namelen, *worker->env.now, &edns_vs,
                        &edns_lame_known, &to)) {
                        if(edns_vs == -1) {
                                if(!ssl_printf(ssl, ", noEDNS%s.",
                                        edns_lame_known?" probed":" assumed"))
                                        return;
                        } else {
                                if(!ssl_printf(ssl, ", EDNS %d%s.", edns_vs,
                                        edns_lame_known?" probed":" assumed"))
                                        return;
                        }
                }
                if(!ssl_printf(ssl, "\n"))
                        return;
        }
}

/** print main dp info */
static void
print_dp_main(RES* ssl, struct delegpt* dp, struct dns_msg* msg)
{
        size_t i, n_ns, n_miss, n_addr, n_res, n_avail;

        /* print the dp */
        if(msg)
            for(i=0; i<msg->rep->rrset_count; i++) {
                struct ub_packed_rrset_key* k = msg->rep->rrsets[i];
                struct packed_rrset_data* d = 
                        (struct packed_rrset_data*)k->entry.data;
                struct config_strlist_head txt;
                memset(&txt, 0, sizeof(txt));
                if(d->security == sec_status_bogus) {
                        if(!ssl_printf(ssl, "Address is BOGUS:\n"))
                                return;
                }
                dump_rrset(&txt, k, d, 0);
                if(!spool_strlist(ssl, txt.first)) {
                        config_delstrlist(txt.first);
                        return;
                }
                config_delstrlist(txt.first);
            }
        delegpt_count_ns(dp, &n_ns, &n_miss);
        delegpt_count_addr(dp, &n_addr, &n_res, &n_avail);
        /* since dp has not been used by iterator, all are available*/
        if(!ssl_printf(ssl, "Delegation with %d names, of which %d "
                "can be examined to query further addresses.\n"
                "%sIt provides %d IP addresses.\n", 
                (int)n_ns, (int)n_miss, (dp->bogus?"It is BOGUS. ":""),
                (int)n_addr))
                return;
}

int print_deleg_lookup(RES* ssl, struct worker* worker, uint8_t* nm,
        size_t nmlen, int ATTR_UNUSED(nmlabs))
{
        /* deep links into the iterator module */
        struct delegpt* dp;
        struct dns_msg* msg;
        struct regional* region = worker->scratchpad;
        char b[LDNS_MAX_DOMAINLEN];
        struct query_info qinfo;
        struct iter_hints_stub* stub;
        int nolock = 0;
        regional_free_all(region);
        qinfo.qname = nm;
        qinfo.qname_len = nmlen;
        qinfo.qtype = LDNS_RR_TYPE_A;
        qinfo.qclass = LDNS_RR_CLASS_IN;
        qinfo.local_alias = NULL;

        dname_str(nm, b);
        if(!ssl_printf(ssl, "The following name servers are used for lookup "
                "of %s\n", b)) 
                return 0;

        dp = forwards_lookup(worker->env.fwds, nm, qinfo.qclass, nolock);
        if(dp) {
                if(!ssl_printf(ssl, "forwarding request:\n")) {
                        lock_rw_unlock(&worker->env.fwds->lock);
                        return 0;
                }
                print_dp_main(ssl, dp, NULL);
                print_dp_details(ssl, worker, dp);
                lock_rw_unlock(&worker->env.fwds->lock);
                return 1;
        }
        
        while(1) {
                dp = dns_cache_find_delegation(&worker->env, nm, nmlen, 
                        qinfo.qtype, qinfo.qclass, region, &msg, 
                        *worker->env.now, 0, NULL, 0);
                if(!dp) {
                        return ssl_printf(ssl, "no delegation from "
                                "cache; goes to configured roots\n");
                }
                /* go up? */
                if(iter_dp_is_useless(&qinfo, BIT_RD, dp,
                        (worker->env.cfg->do_ip4 && worker->back->num_ip4 != 0),
                        (worker->env.cfg->do_ip6 && worker->back->num_ip6 != 0),
                        worker->env.cfg->do_nat64)) {
                        print_dp_main(ssl, dp, msg);
                        print_dp_details(ssl, worker, dp);
                        if(!ssl_printf(ssl, "cache delegation was "
                                "useless (no IP addresses)\n"))
                                return 0;
                        if(dname_is_root(nm)) {
                                /* goes to root config */
                                return ssl_printf(ssl, "no delegation from "
                                        "cache; goes to configured roots\n");
                        } else {
                                /* useless, goes up */
                                nm = dp->name;
                                nmlen = dp->namelen;
                                dname_remove_label(&nm, &nmlen);
                                dname_str(nm, b);
                                if(!ssl_printf(ssl, "going up, lookup %s\n", b))
                                        return 0;
                                continue;
                        }
                }
                stub = hints_lookup_stub(worker->env.hints, nm, qinfo.qclass,
                        dp, nolock);
                if(stub) {
                        if(stub->noprime) {
                                if(!ssl_printf(ssl, "The noprime stub servers "
                                        "are used:\n")) {
                                        lock_rw_unlock(&worker->env.hints->lock);
                                        return 0;
                                }
                        } else {
                                if(!ssl_printf(ssl, "The stub is primed "
                                                "with servers:\n")) {
                                        lock_rw_unlock(&worker->env.hints->lock);
                                        return 0;
                                }
                        }
                        print_dp_main(ssl, stub->dp, NULL);
                        print_dp_details(ssl, worker, stub->dp);
                        lock_rw_unlock(&worker->env.hints->lock);
                } else {
                        print_dp_main(ssl, dp, msg);
                        print_dp_details(ssl, worker, dp);
                }
                break;
        }

        return 1;
}