/*
 * libunbound/context.c - validating context for unbound internal use
 *
 * Copyright (c) 2007, 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 the validator context structure.
 */
#include "config.h"
#include "libunbound/context.h"
#include "util/module.h"
#include "util/config_file.h"
#include "util/net_help.h"
#include "services/modstack.h"
#include "services/localzone.h"
#include "services/cache/rrset.h"
#include "services/cache/infra.h"
#include "services/authzone.h"
#include "services/listen_dnsport.h"
#include "util/data/msgreply.h"
#include "util/storage/slabhash.h"
#include "util/edns.h"
#include "sldns/sbuffer.h"
#include "iterator/iter_fwd.h"
#include "iterator/iter_hints.h"

int 
context_finalize(struct ub_ctx* ctx)
{
        int is_rpz = 0;
        struct config_file* cfg = ctx->env->cfg;
        verbosity = cfg->verbosity;
        if(ctx_logfile_overridden && !ctx->logfile_override) {
                log_file(NULL); /* clear that override */
                ctx_logfile_overridden = 0;
        }
        if(ctx->logfile_override) {
                ctx_logfile_overridden = 1;
                log_file(ctx->log_out);
        } else {
                log_init(cfg->logfile, cfg->use_syslog, NULL);
        }
        ctx->pipe_pid = getpid();
        cfg_apply_local_port_policy(cfg, 65536);
        config_apply(cfg);
        if(!modstack_call_startup(&ctx->mods, cfg->module_conf, ctx->env))
                return UB_INITFAIL;
        if(!modstack_call_init(&ctx->mods, cfg->module_conf, ctx->env))
                return UB_INITFAIL;
        listen_setup_locks();
        log_edns_known_options(VERB_ALGO, ctx->env);
        ctx->local_zones = local_zones_create();
        if(!ctx->local_zones)
                return UB_NOMEM;
        if(!local_zones_apply_cfg(ctx->local_zones, cfg))
                return UB_INITFAIL;
        if(!auth_zones_apply_cfg(ctx->env->auth_zones, cfg, 1, &is_rpz,
                ctx->env, &ctx->mods))
                return UB_INITFAIL;
        if(!(ctx->env->fwds = forwards_create()) ||
                !forwards_apply_cfg(ctx->env->fwds, cfg))
                return UB_INITFAIL;
        if(!(ctx->env->hints = hints_create()) ||
                !hints_apply_cfg(ctx->env->hints, cfg))
                return UB_INITFAIL;
        if(!edns_strings_apply_cfg(ctx->env->edns_strings, cfg))
                return UB_INITFAIL;
        if(!slabhash_is_size(ctx->env->msg_cache, cfg->msg_cache_size,
                cfg->msg_cache_slabs)) {
                slabhash_delete(ctx->env->msg_cache);
                ctx->env->msg_cache = slabhash_create(cfg->msg_cache_slabs,
                        HASH_DEFAULT_STARTARRAY, cfg->msg_cache_size,
                        msgreply_sizefunc, query_info_compare,
                        query_entry_delete, reply_info_delete, NULL);
                if(!ctx->env->msg_cache)
                        return UB_NOMEM;
        }
        ctx->env->rrset_cache = rrset_cache_adjust(ctx->env->rrset_cache,
                ctx->env->cfg, ctx->env->alloc);
        if(!ctx->env->rrset_cache)
                return UB_NOMEM;
        ctx->env->infra_cache = infra_adjust(ctx->env->infra_cache, cfg);
        if(!ctx->env->infra_cache)
                return UB_NOMEM;
        ctx->finalized = 1;
        return UB_NOERROR;
}

int context_query_cmp(const void* a, const void* b)
{
        if( *(int*)a < *(int*)b )
                return -1;
        if( *(int*)a > *(int*)b )
                return 1;
        return 0;
}

void
context_query_delete(struct ctx_query* q) 
{
        if(!q) return;
        ub_resolve_free(q->res);
        free(q->msg);
        free(q);
}

/** How many times to try to find an unused query-id-number for async */
#define NUM_ID_TRIES 100000
/** find next useful id number of 0 on error */
static int
find_id(struct ub_ctx* ctx, int* id)
{
        size_t tries = 0;
        ctx->next_querynum++;
        while(rbtree_search(&ctx->queries, &ctx->next_querynum)) {
                ctx->next_querynum++; /* numerical wraparound is fine */
                if(tries++ > NUM_ID_TRIES)
                        return 0;
        }
        *id = ctx->next_querynum;
        return 1;
}

struct ctx_query* 
context_new(struct ub_ctx* ctx, const char* name, int rrtype, int rrclass, 
        ub_callback_type cb, ub_event_callback_type cb_event, void* cbarg)
{
        struct ctx_query* q = (struct ctx_query*)calloc(1, sizeof(*q));
        if(!q) return NULL;
        lock_basic_lock(&ctx->cfglock);
        if(!find_id(ctx, &q->querynum)) {
                lock_basic_unlock(&ctx->cfglock);
                free(q);
                return NULL;
        }
        lock_basic_unlock(&ctx->cfglock);
        q->node.key = &q->querynum;
        q->async = (cb != NULL || cb_event != NULL);
        q->cb = cb;
        q->cb_event = cb_event;
        q->cb_arg = cbarg;
        q->res = (struct ub_result*)calloc(1, sizeof(*q->res));
        if(!q->res) {
                free(q);
                return NULL;
        }
        q->res->qname = strdup(name);
        if(!q->res->qname) {
                free(q->res);
                free(q);
                return NULL;
        }
        q->res->qtype = rrtype;
        q->res->qclass = rrclass;

        /* add to query list */
        lock_basic_lock(&ctx->cfglock);
        if(q->async)
                ctx->num_async ++;
        (void)rbtree_insert(&ctx->queries, &q->node);
        lock_basic_unlock(&ctx->cfglock);
        return q;
}

struct alloc_cache* 
context_obtain_alloc(struct ub_ctx* ctx, int locking)
{
        struct alloc_cache* a;
        int tnum = 0;
        if(locking) {
                lock_basic_lock(&ctx->cfglock);
        }
        a = ctx->alloc_list;
        if(a)
                ctx->alloc_list = a->super; /* snip off list */
        else    tnum = ctx->thr_next_num++;
        if(locking) {
                lock_basic_unlock(&ctx->cfglock);
        }
        if(a) {
                a->super = &ctx->superalloc;
                return a;
        }
        a = (struct alloc_cache*)calloc(1, sizeof(*a));
        if(!a)
                return NULL;
        alloc_init(a, &ctx->superalloc, tnum);
        return a;
}

void 
context_release_alloc(struct ub_ctx* ctx, struct alloc_cache* alloc,
        int locking)
{
        if(!ctx || !alloc)
                return;
        if(locking) {
                lock_basic_lock(&ctx->cfglock);
        }
        alloc->super = ctx->alloc_list;
        ctx->alloc_list = alloc;
        if(locking) {
                lock_basic_unlock(&ctx->cfglock);
        }
}

uint8_t* 
context_serialize_new_query(struct ctx_query* q, uint32_t* len)
{
        /* format for new query is
         *      o uint32 cmd
         *      o uint32 id
         *      o uint32 type
         *      o uint32 class
         *      o rest queryname (string)
         */
        uint8_t* p;
        size_t slen = strlen(q->res->qname) + 1/*end of string*/;
        *len = sizeof(uint32_t)*4 + slen;
        p = (uint8_t*)malloc(*len);
        if(!p) return NULL;
        sldns_write_uint32(p, UB_LIBCMD_NEWQUERY);
        sldns_write_uint32(p+sizeof(uint32_t), (uint32_t)q->querynum);
        sldns_write_uint32(p+2*sizeof(uint32_t), (uint32_t)q->res->qtype);
        sldns_write_uint32(p+3*sizeof(uint32_t), (uint32_t)q->res->qclass);
        memmove(p+4*sizeof(uint32_t), q->res->qname, slen);
        return p;
}

struct ctx_query* 
context_deserialize_new_query(struct ub_ctx* ctx, uint8_t* p, uint32_t len)
{
        struct ctx_query* q = (struct ctx_query*)calloc(1, sizeof(*q));
        if(!q) return NULL;
        if(len < 4*sizeof(uint32_t)+1) {
                free(q);
                return NULL;
        }
        log_assert( sldns_read_uint32(p) == UB_LIBCMD_NEWQUERY);
        q->querynum = (int)sldns_read_uint32(p+sizeof(uint32_t));
        q->node.key = &q->querynum;
        q->async = 1;
        q->res = (struct ub_result*)calloc(1, sizeof(*q->res));
        if(!q->res) {
                free(q);
                return NULL;
        }
        q->res->qtype = (int)sldns_read_uint32(p+2*sizeof(uint32_t));
        q->res->qclass = (int)sldns_read_uint32(p+3*sizeof(uint32_t));
        q->res->qname = strdup((char*)(p+4*sizeof(uint32_t)));
        if(!q->res->qname) {
                free(q->res);
                free(q);
                return NULL;
        }

        /** add to query list */
        ctx->num_async++;
        (void)rbtree_insert(&ctx->queries, &q->node);
        return q;
}

struct ctx_query* 
context_lookup_new_query(struct ub_ctx* ctx, uint8_t* p, uint32_t len)
{
        struct ctx_query* q;
        int querynum;
        if(len < 4*sizeof(uint32_t)+1) {
                return NULL;
        }
        log_assert( sldns_read_uint32(p) == UB_LIBCMD_NEWQUERY);
        querynum = (int)sldns_read_uint32(p+sizeof(uint32_t));
        q = (struct ctx_query*)rbtree_search(&ctx->queries, &querynum);
        if(!q) {
                return NULL;
        }
        log_assert(q->async);
        return q;
}

uint8_t* 
context_serialize_answer(struct ctx_query* q, int err, sldns_buffer* pkt,
        uint32_t* len)
{
        /* answer format
         *      o uint32 cmd
         *      o uint32 id
         *      o uint32 error_code
         *      o uint32 msg_security
         *      o uint32 was_ratelimited
         *      o uint32 length of why_bogus string (+1 for eos); 0 absent.
         *      o why_bogus_string
         *      o the remainder is the answer msg from resolver lookup.
         *        remainder can be length 0.
         */
        size_t size_of_uint32s = 6 * sizeof(uint32_t);
        size_t pkt_len = pkt?sldns_buffer_remaining(pkt):0;
        size_t wlen = (pkt&&q->res->why_bogus)?strlen(q->res->why_bogus)+1:0;
        uint8_t* p;
        *len = size_of_uint32s + pkt_len + wlen;
        p = (uint8_t*)malloc(*len);
        if(!p) return NULL;
        sldns_write_uint32(p, UB_LIBCMD_ANSWER);
        sldns_write_uint32(p+sizeof(uint32_t), (uint32_t)q->querynum);
        sldns_write_uint32(p+2*sizeof(uint32_t), (uint32_t)err);
        sldns_write_uint32(p+3*sizeof(uint32_t), (uint32_t)q->msg_security);
        sldns_write_uint32(p+4*sizeof(uint32_t), (uint32_t)q->res->was_ratelimited);
        sldns_write_uint32(p+5*sizeof(uint32_t), (uint32_t)wlen);
        if(wlen > 0)
                memmove(p+size_of_uint32s, q->res->why_bogus, wlen);
        if(pkt_len > 0)
                memmove(p+size_of_uint32s+wlen,
                        sldns_buffer_begin(pkt), pkt_len);
        return p;
}

struct ctx_query* 
context_deserialize_answer(struct ub_ctx* ctx,
        uint8_t* p, uint32_t len, int* err)
{
        size_t size_of_uint32s = 6 * sizeof(uint32_t);
        struct ctx_query* q = NULL ;
        int id;
        size_t wlen;
        if(len < size_of_uint32s) return NULL;
        log_assert( sldns_read_uint32(p) == UB_LIBCMD_ANSWER);
        id = (int)sldns_read_uint32(p+sizeof(uint32_t));
        q = (struct ctx_query*)rbtree_search(&ctx->queries, &id);
        if(!q) return NULL; 
        *err = (int)sldns_read_uint32(p+2*sizeof(uint32_t));
        q->msg_security = sldns_read_uint32(p+3*sizeof(uint32_t));
        q->res->was_ratelimited = (int)sldns_read_uint32(p+4*sizeof(uint32_t));
        wlen = (size_t)sldns_read_uint32(p+5*sizeof(uint32_t));
        if(len > size_of_uint32s && wlen > 0) {
                if(len >= size_of_uint32s+wlen)
                        q->res->why_bogus = (char*)memdup(
                                p+size_of_uint32s, wlen);
                if(!q->res->why_bogus) {
                        /* pass malloc failure to the user callback */
                        q->msg_len = 0;
                        *err = UB_NOMEM;
                        return q;
                }
                q->res->why_bogus[wlen-1] = 0; /* zero terminated for sure */
        }
        if(len > size_of_uint32s+wlen) {
                q->msg_len = len - size_of_uint32s - wlen;
                q->msg = (uint8_t*)memdup(p+size_of_uint32s+wlen,
                        q->msg_len);
                if(!q->msg) {
                        /* pass malloc failure to the user callback */
                        q->msg_len = 0;
                        *err = UB_NOMEM;
                        return q;
                }
        } 
        return q;
}

uint8_t* 
context_serialize_cancel(struct ctx_query* q, uint32_t* len)
{
        /* format of cancel:
         *      o uint32 cmd
         *      o uint32 async-id */
        uint8_t* p = (uint8_t*)reallocarray(NULL, 2, sizeof(uint32_t));
        if(!p) return NULL;
        *len = 2*sizeof(uint32_t);
        sldns_write_uint32(p, UB_LIBCMD_CANCEL);
        sldns_write_uint32(p+sizeof(uint32_t), (uint32_t)q->querynum);
        return p;
}

struct ctx_query* context_deserialize_cancel(struct ub_ctx* ctx,
        uint8_t* p, uint32_t len)
{
        struct ctx_query* q;
        int id;
        if(len != 2*sizeof(uint32_t)) return NULL;
        log_assert( sldns_read_uint32(p) == UB_LIBCMD_CANCEL);
        id = (int)sldns_read_uint32(p+sizeof(uint32_t));
        q = (struct ctx_query*)rbtree_search(&ctx->queries, &id);
        return q;
}

uint8_t* 
context_serialize_quit(uint32_t* len)
{
        uint32_t* p = (uint32_t*)malloc(sizeof(uint32_t));
        if(!p)
                return NULL;
        *len = sizeof(uint32_t);
        sldns_write_uint32(p, UB_LIBCMD_QUIT);
        return (uint8_t*)p;
}

enum ub_ctx_cmd context_serial_getcmd(uint8_t* p, uint32_t len)
{
        uint32_t v;
        if((size_t)len < sizeof(v))
                return UB_LIBCMD_QUIT;
        v = sldns_read_uint32(p);
        return v;
}