common/irs/gen_sv.c

/*
 * 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_sv.c,v 1.3 2005/04/27 04:56:24 sra Exp $";
#endif

/* Imports */

#include "port_before.h"

#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <resolv.h>

#include <errno.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         sv_close(struct irs_sv*);
static struct servent *     sv_next(struct irs_sv *);
static struct servent *     sv_byname(struct irs_sv *, const char *,
                      const char *);
static struct servent *     sv_byport(struct irs_sv *, int, const char *);
static void         sv_rewind(struct irs_sv *);
static void         sv_minimize(struct irs_sv *);
static struct __res_state * sv_res_get(struct irs_sv *);
static void         sv_res_set(struct irs_sv *,
                          struct __res_state *,
                          void (*)(void *));

/* Public */

struct irs_sv *
irs_gen_sv(struct irs_acc *this) {
    struct gen_p *accpvt = (struct gen_p *)this->private;
    struct irs_sv *sv;
    struct pvt *pvt;

    if (!(sv = memget(sizeof *sv))) {
        errno = ENOMEM;
        return (NULL);
    }
    memset(sv, 0x5e, sizeof *sv);
    if (!(pvt = memget(sizeof *pvt))) {
        memput(sv, sizeof *sv);
        errno = ENOMEM;
        return (NULL);
    }
    memset(pvt, 0, sizeof *pvt);
    pvt->rules = accpvt->map_rules[irs_sv];
    pvt->rule = pvt->rules;
    sv->private = pvt;
    sv->close = sv_close;
    sv->next = sv_next;
    sv->byname = sv_byname;
    sv->byport = sv_byport;
    sv->rewind = sv_rewind;
    sv->minimize = sv_minimize;
    sv->res_get = sv_res_get;
    sv->res_set = sv_res_set;
    return (sv);
}

/* Methods */

static void
sv_close(struct irs_sv *this) {
    struct pvt *pvt = (struct pvt *)this->private;

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

static struct servent *
sv_next(struct irs_sv *this) {
    struct pvt *pvt = (struct pvt *)this->private;
    struct servent *rval;
    struct irs_sv *sv;

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

static struct servent *
sv_byname(struct irs_sv *this, const char *name, const char *proto) {
    struct pvt *pvt = (struct pvt *)this->private;
    struct irs_rule *rule;
    struct servent *rval;
    struct irs_sv *sv;

    rval = NULL;
    for (rule = pvt->rules; rule; rule = rule->next) {
        sv = rule->inst->sv;
        rval = (*sv->byname)(sv, name, proto);
        if (rval || !(rule->flags & IRS_CONTINUE))
            break;
    }
    return (rval);
}

static struct servent *
sv_byport(struct irs_sv *this, int port, const char *proto) {
    struct pvt *pvt = (struct pvt *)this->private;
    struct irs_rule *rule;
    struct servent *rval;
    struct irs_sv *sv;

    rval = NULL;
    for (rule = pvt->rules; rule; rule = rule->next) {
        sv = rule->inst->sv;
        rval = (*sv->byport)(sv, port, proto);
        if (rval || !(rule->flags & IRS_CONTINUE))
            break;
    }
    return (rval);
}

static void
sv_rewind(struct irs_sv *this) {
    struct pvt *pvt = (struct pvt *)this->private;
    struct irs_sv *sv;

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

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

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

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

static struct __res_state *
sv_res_get(struct irs_sv *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);
        sv_res_set(this, res, free);
    }

    return (pvt->res);
}

static void
sv_res_set(struct irs_sv *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_sv *sv = rule->inst->sv;

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

/*! \file */