NetBSD/dist/bind/lib/irs/gen_ho.c

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1999-11-20 21:53:57 +03:00
/* $NetBSD: gen_ho.c,v 1.1.1.1 1999/11/20 18:54:08 veego Exp $ */
/*
* 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 INTERNET SOFTWARE CONSORTIUM DISCLAIMS
* ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
* CONSORTIUM 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(LIBC_SCCS) && !defined(lint)
static const char rcsid[] = "Id: gen_ho.c,v 1.15 1999/10/13 16:39:29 vixie Exp";
#endif /* LIBC_SCCS and not lint */
/* Imports */
#include "port_before.h"
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <errno.h>
#include <stdlib.h>
#include <netdb.h>
#include <resolv.h>
#include <stdio.h>
#include <string.h>
#include <isc/memcluster.h>
#include <irs.h>
#include "port_after.h"
#include "irs_p.h"
#include "gen_p.h"
/* Definitions */
struct pvt {
struct irs_rule * rules;
struct irs_rule * rule;
struct irs_ho * ho;
struct __res_state * res;
void (*free_res)(void *);
};
/* Forwards */
static void ho_close(struct irs_ho *this);
static struct hostent * ho_byname(struct irs_ho *this, const char *name);
static struct hostent * ho_byname2(struct irs_ho *this, const char *name,
int af);
static struct hostent * ho_byaddr(struct irs_ho *this, const void *addr,
int len, int af);
static struct hostent * ho_next(struct irs_ho *this);
static void ho_rewind(struct irs_ho *this);
static void ho_minimize(struct irs_ho *this);
static struct __res_state * ho_res_get(struct irs_ho *this);
static void ho_res_set(struct irs_ho *this,
struct __res_state *res,
void (*free_res)(void *));
static int init(struct irs_ho *this);
/* Exports */
struct irs_ho *
irs_gen_ho(struct irs_acc *this) {
struct gen_p *accpvt = (struct gen_p *)this->private;
struct irs_ho *ho;
struct pvt *pvt;
if (!(pvt = memget(sizeof *pvt))) {
errno = ENOMEM;
return (NULL);
}
memset(pvt, 0, sizeof *pvt);
if (!(ho = memget(sizeof *ho))) {
memput(pvt, sizeof *pvt);
errno = ENOMEM;
return (NULL);
}
memset(ho, 0x5e, sizeof *ho);
pvt->rules = accpvt->map_rules[irs_ho];
pvt->rule = pvt->rules;
ho->private = pvt;
ho->close = ho_close;
ho->byname = ho_byname;
ho->byname2 = ho_byname2;
ho->byaddr = ho_byaddr;
ho->next = ho_next;
ho->rewind = ho_rewind;
ho->minimize = ho_minimize;
ho->res_get = ho_res_get;
ho->res_set = ho_res_set;
return (ho);
}
/* Methods. */
static void
ho_close(struct irs_ho *this) {
struct pvt *pvt = (struct pvt *)this->private;
ho_minimize(this);
if (pvt->res && pvt->free_res)
(*pvt->free_res)(pvt->res);
memput(pvt, sizeof *pvt);
memput(this, sizeof *this);
}
static struct hostent *
ho_byname(struct irs_ho *this, const char *name) {
struct pvt *pvt = (struct pvt *)this->private;
struct irs_rule *rule;
struct hostent *rval;
struct irs_ho *ho;
int therrno = NETDB_INTERNAL;
int softerror = 0;
if (init(this) == -1)
return (NULL);
for (rule = pvt->rules; rule; rule = rule->next) {
ho = rule->inst->ho;
RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL);
errno = 0;
rval = (*ho->byname)(ho, name);
if (rval != NULL)
return (rval);
if (softerror == 0 &&
pvt->res->res_h_errno != HOST_NOT_FOUND &&
pvt->res->res_h_errno != NETDB_INTERNAL) {
softerror = 1;
therrno = pvt->res->res_h_errno;
}
if (rule->flags & IRS_CONTINUE)
continue;
/*
* The value TRY_AGAIN can mean that the service
* is not available, or just that this particular name
* cannot be resolved now. We use the errno ECONNREFUSED
* to distinguish. If a lookup sets that errno when
* H_ERRNO is TRY_AGAIN, we continue to try other lookup
* functions, otherwise we return the TRY_AGAIN error.
*/
if (pvt->res->res_h_errno != TRY_AGAIN || errno != ECONNREFUSED)
break;
}
if (softerror != 0 && pvt->res->res_h_errno == HOST_NOT_FOUND)
RES_SET_H_ERRNO(pvt->res, therrno);
return (NULL);
}
static struct hostent *
ho_byname2(struct irs_ho *this, const char *name, int af) {
struct pvt *pvt = (struct pvt *)this->private;
struct irs_rule *rule;
struct hostent *rval;
struct irs_ho *ho;
int therrno = NETDB_INTERNAL;
int softerror = 0;
if (init(this) == -1)
return (NULL);
for (rule = pvt->rules; rule; rule = rule->next) {
ho = rule->inst->ho;
RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL);
errno = 0;
rval = (*ho->byname2)(ho, name, af);
if (rval != NULL)
return (rval);
if (softerror == 0 &&
pvt->res->res_h_errno != HOST_NOT_FOUND &&
pvt->res->res_h_errno != NETDB_INTERNAL) {
softerror = 1;
therrno = pvt->res->res_h_errno;
}
if (rule->flags & IRS_CONTINUE)
continue;
/*
* See the comments in ho_byname() explaining
* the interpretation of TRY_AGAIN and ECONNREFUSED.
*/
if (pvt->res->res_h_errno != TRY_AGAIN || errno != ECONNREFUSED)
break;
}
if (softerror != 0 && pvt->res->res_h_errno == HOST_NOT_FOUND)
RES_SET_H_ERRNO(pvt->res, therrno);
return (NULL);
}
static struct hostent *
ho_byaddr(struct irs_ho *this, const void *addr, int len, int af) {
struct pvt *pvt = (struct pvt *)this->private;
struct irs_rule *rule;
struct hostent *rval;
struct irs_ho *ho;
int therrno = NETDB_INTERNAL;
int softerror = 0;
if (init(this) == -1)
return (NULL);
for (rule = pvt->rules; rule; rule = rule->next) {
ho = rule->inst->ho;
RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL);
errno = 0;
rval = (*ho->byaddr)(ho, addr, len, af);
if (rval != NULL)
return (rval);
if (softerror == 0 &&
pvt->res->res_h_errno != HOST_NOT_FOUND &&
pvt->res->res_h_errno != NETDB_INTERNAL) {
softerror = 1;
therrno = pvt->res->res_h_errno;
}
if (rule->flags & IRS_CONTINUE)
continue;
/*
* See the comments in ho_byname() explaining
* the interpretation of TRY_AGAIN and ECONNREFUSED.
*/
if (pvt->res->res_h_errno != TRY_AGAIN || errno != ECONNREFUSED)
break;
}
if (softerror != 0 && pvt->res->res_h_errno == HOST_NOT_FOUND)
RES_SET_H_ERRNO(pvt->res, therrno);
return (NULL);
}
static struct hostent *
ho_next(struct irs_ho *this) {
struct pvt *pvt = (struct pvt *)this->private;
struct hostent *rval;
struct irs_ho *ho;
while (pvt->rule) {
ho = pvt->rule->inst->ho;
rval = (*ho->next)(ho);
if (rval)
return (rval);
if (!(pvt->rule->flags & IRS_CONTINUE))
break;
pvt->rule = pvt->rule->next;
if (pvt->rule) {
ho = pvt->rule->inst->ho;
(*ho->rewind)(ho);
}
}
return (NULL);
}
static void
ho_rewind(struct irs_ho *this) {
struct pvt *pvt = (struct pvt *)this->private;
struct irs_ho *ho;
pvt->rule = pvt->rules;
if (pvt->rule) {
ho = pvt->rule->inst->ho;
(*ho->rewind)(ho);
}
}
static void
ho_minimize(struct irs_ho *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_ho *ho = rule->inst->ho;
(*ho->minimize)(ho);
}
}
static struct __res_state *
ho_res_get(struct irs_ho *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);
ho_res_set(this, res, free);
}
return (pvt->res);
}
static void
ho_res_set(struct irs_ho *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_ho *ho = rule->inst->ho;
(*ho->res_set)(ho, pvt->res, NULL);
}
}
static int
init(struct irs_ho *this) {
struct pvt *pvt = (struct pvt *)this->private;
if (!pvt->res && !ho_res_get(this))
return (-1);
if (((pvt->res->options & RES_INIT) == 0) &&
(res_ninit(pvt->res) == -1))
return (-1);
return (0);
}