/*      $NetBSD: gen_nw.c,v 1.1.1.2 2012/09/09 16:07:55 christos Exp $  */

/*
* Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
* Copyright (c) 1996,1999 by Internet Software Consortium.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
* OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/

#if !defined(LINT) && !defined(CODECENTER)
static const char rcsid[] = "Id: gen_nw.c,v 1.4 2005/04/27 04:56:23 sra Exp ";
#endif

/* Imports */

#include "port_before.h"

#include <sys/types.h>

#include <netinet/in.h>
#include <arpa/nameser.h>

#include <errno.h>
#include <resolv.h>
#include <stdlib.h>
#include <string.h>

#include <isc/memcluster.h>
#include <irs.h>

#include "port_after.h"

#include "irs_p.h"
#include "gen_p.h"

/* Types */

struct pvt {
       struct irs_rule *       rules;
       struct irs_rule *       rule;
       struct __res_state *    res;
       void                    (*free_res)(void *);
};

/* Forward */

static void             nw_close(struct irs_nw*);
static struct nwent *   nw_next(struct irs_nw *);
static struct nwent *   nw_byname(struct irs_nw *, const char *, int);
static struct nwent *   nw_byaddr(struct irs_nw *, void *, int, int);
static void             nw_rewind(struct irs_nw *);
static void             nw_minimize(struct irs_nw *);
static struct __res_state * nw_res_get(struct irs_nw *this);
static void             nw_res_set(struct irs_nw *this,
                                  struct __res_state *res,
                                  void (*free_res)(void *));

static int              init(struct irs_nw *this);

/* Public */

struct irs_nw *
irs_gen_nw(struct irs_acc *this) {
       struct gen_p *accpvt = (struct gen_p *)this->private;
       struct irs_nw *nw;
       struct pvt *pvt;

       if (!(pvt = memget(sizeof *pvt))) {
               errno = ENOMEM;
               return (NULL);
       }
       memset(pvt, 0, sizeof *pvt);
       if (!(nw = memget(sizeof *nw))) {
               memput(pvt, sizeof *pvt);
               errno = ENOMEM;
               return (NULL);
       }
       memset(nw, 0x5e, sizeof *nw);
       pvt->rules = accpvt->map_rules[irs_nw];
       pvt->rule = pvt->rules;
       nw->private = pvt;
       nw->close = nw_close;
       nw->next = nw_next;
       nw->byname = nw_byname;
       nw->byaddr = nw_byaddr;
       nw->rewind = nw_rewind;
       nw->minimize = nw_minimize;
       nw->res_get = nw_res_get;
       nw->res_set = nw_res_set;
       return (nw);
}

/* Methods */

static void
nw_close(struct irs_nw *this) {
       struct pvt *pvt = (struct pvt *)this->private;

       nw_minimize(this);

       if (pvt->res && pvt->free_res)
               (*pvt->free_res)(pvt->res);

       memput(pvt, sizeof *pvt);
       memput(this, sizeof *this);
}

static struct nwent *
nw_next(struct irs_nw *this) {
       struct pvt *pvt = (struct pvt *)this->private;
       struct nwent *rval;
       struct irs_nw *nw;

       if (init(this) == -1)
               return(NULL);

       while (pvt->rule) {
               nw = pvt->rule->inst->nw;
               rval = (*nw->next)(nw);
               if (rval)
                       return (rval);
               if (!(pvt->rules->flags & IRS_CONTINUE))
                       break;
               pvt->rule = pvt->rule->next;
               if (pvt->rule) {
                       nw = pvt->rule->inst->nw;
                       (*nw->rewind)(nw);
               }
       }
       return (NULL);
}

static struct nwent *
nw_byname(struct irs_nw *this, const char *name, int type) {
       struct pvt *pvt = (struct pvt *)this->private;
       struct irs_rule *rule;
       struct nwent *rval;
       struct irs_nw *nw;

       if (init(this) == -1)
               return(NULL);

       for (rule = pvt->rules; rule; rule = rule->next) {
               nw = rule->inst->nw;
               RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL);
               rval = (*nw->byname)(nw, name, type);
               if (rval != NULL)
                       return (rval);
               if (pvt->res->res_h_errno != TRY_AGAIN &&
                   !(rule->flags & IRS_CONTINUE))
                       break;
       }
       return (NULL);
}

static struct nwent *
nw_byaddr(struct irs_nw *this, void *net, int length, int type) {
       struct pvt *pvt = (struct pvt *)this->private;
       struct irs_rule *rule;
       struct nwent *rval;
       struct irs_nw *nw;

       if (init(this) == -1)
               return(NULL);

       for (rule = pvt->rules; rule; rule = rule->next) {
               nw = rule->inst->nw;
               RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL);
               rval = (*nw->byaddr)(nw, net, length, type);
               if (rval != NULL)
                       return (rval);
               if (pvt->res->res_h_errno != TRY_AGAIN &&
                   !(rule->flags & IRS_CONTINUE))
                       break;
       }
       return (NULL);
}

static void
nw_rewind(struct irs_nw *this) {
       struct pvt *pvt = (struct pvt *)this->private;
       struct irs_nw *nw;

       pvt->rule = pvt->rules;
       if (pvt->rule) {
               nw = pvt->rule->inst->nw;
               (*nw->rewind)(nw);
       }
}

static void
nw_minimize(struct irs_nw *this) {
       struct pvt *pvt = (struct pvt *)this->private;
       struct irs_rule *rule;

       if (pvt->res)
               res_nclose(pvt->res);
       for (rule = pvt->rules; rule != NULL; rule = rule->next) {
               struct irs_nw *nw = rule->inst->nw;

               (*nw->minimize)(nw);
       }
}

static struct __res_state *
nw_res_get(struct irs_nw *this) {
       struct pvt *pvt = (struct pvt *)this->private;

       if (!pvt->res) {
               struct __res_state *res;
               res = (struct __res_state *)malloc(sizeof *res);
               if (!res) {
                       errno = ENOMEM;
                       return (NULL);
               }
               memset(res, 0, sizeof *res);
               nw_res_set(this, res, free);
       }

       return (pvt->res);
}

static void
nw_res_set(struct irs_nw *this, struct __res_state *res,
               void (*free_res)(void *)) {
       struct pvt *pvt = (struct pvt *)this->private;
       struct irs_rule *rule;

       if (pvt->res && pvt->free_res) {
               res_nclose(pvt->res);
               (*pvt->free_res)(pvt->res);
       }

       pvt->res = res;
       pvt->free_res = free_res;

       for (rule = pvt->rules; rule != NULL; rule = rule->next) {
               struct irs_nw *nw = rule->inst->nw;

               (*nw->res_set)(nw, pvt->res, NULL);
       }
}

static int
init(struct irs_nw *this) {
       struct pvt *pvt = (struct pvt *)this->private;

       if (!pvt->res && !nw_res_get(this))
               return (-1);
       if (((pvt->res->options & RES_INIT) == 0U) &&
           res_ninit(pvt->res) == -1)
               return (-1);
       return (0);
}

/*! \file */

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