/*
 * 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.
 */

/* Imports */

#include "port_before.h"

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

#include <stdio.h>
#include <string.h>
#include <netdb.h>
#include <ctype.h>
#include <stdlib.h>
#include <errno.h>

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

#include "port_after.h"

#include "irs_p.h"
#include "hesiod.h"
#include "dns_p.h"

/* Types. */

struct pvt {
        struct dns_p *          dns;
        struct protoent         proto;
        char *                  prbuf;
};

/* Forward. */

static void                     pr_close(struct irs_pr *);
static struct protoent *        pr_byname(struct irs_pr *, const char *);
static struct protoent *        pr_bynumber(struct irs_pr *, int);
static struct protoent *        pr_next(struct irs_pr *);
static void                     pr_rewind(struct irs_pr *);
static void                     pr_minimize(struct irs_pr *);
static struct __res_state *     pr_res_get(struct irs_pr *);
static void                     pr_res_set(struct irs_pr *,
                                           struct __res_state *,
                                           void (*)(void *));

static struct protoent *        parse_hes_list(struct irs_pr *, char **);

/* Public. */

struct irs_pr *
irs_dns_pr(struct irs_acc *this) {
        struct dns_p *dns = (struct dns_p *)this->private;
        struct pvt *pvt;
        struct irs_pr *pr;

        if (!dns->hes_ctx) {
                errno = ENODEV;
                return (NULL);
        }
        if (!(pvt = memget(sizeof *pvt))) {
                errno = ENOMEM;
                return (NULL);
        }
        memset(pvt, 0, sizeof *pvt);
        if (!(pr = memget(sizeof *pr))) {
                memput(pvt, sizeof *pvt);
                errno = ENOMEM;
                return (NULL);
        }
        memset(pr, 0x5e, sizeof *pr);
        pvt->dns = dns;
        pr->private = pvt;
        pr->byname = pr_byname;
        pr->bynumber = pr_bynumber;
        pr->next = pr_next;
        pr->rewind = pr_rewind;
        pr->close = pr_close;
        pr->minimize = pr_minimize;
        pr->res_get = pr_res_get;
        pr->res_set = pr_res_set;
        return (pr);
}

/* Methods. */

static void
pr_close(struct irs_pr *this) {
        struct pvt *pvt = (struct pvt *)this->private;

        if (pvt->proto.p_aliases)
                free(pvt->proto.p_aliases);
        if (pvt->prbuf)
                free(pvt->prbuf);

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

static struct protoent *
pr_byname(struct irs_pr *this, const char *name) {
        struct pvt *pvt = (struct pvt *)this->private;
        struct dns_p *dns = pvt->dns;
        struct protoent *proto;
        char **hes_list;

        if (!(hes_list = hesiod_resolve(dns->hes_ctx, name, "protocol")))
                return (NULL);

        proto = parse_hes_list(this, hes_list);
        hesiod_free_list(dns->hes_ctx, hes_list);
        return (proto);
}

static struct protoent *
pr_bynumber(struct irs_pr *this, int num) {
        struct pvt *pvt = (struct pvt *)this->private;
        struct dns_p *dns = pvt->dns;
        struct protoent *proto;
        char numstr[16];
        char **hes_list;

        sprintf(numstr, "%d", num);
        if (!(hes_list = hesiod_resolve(dns->hes_ctx, numstr, "protonum")))
                return (NULL);

        proto = parse_hes_list(this, hes_list);
        hesiod_free_list(dns->hes_ctx, hes_list);
        return (proto);
}

static struct protoent *
pr_next(struct irs_pr *this) {
        UNUSED(this);
        errno = ENODEV;
        return (NULL);
}

static void
pr_rewind(struct irs_pr *this) {
        UNUSED(this);
        /* NOOP */
}

static void
pr_minimize(struct irs_pr *this) {
        UNUSED(this);
        /* NOOP */
}

static struct __res_state *
pr_res_get(struct irs_pr *this) {
        struct pvt *pvt = (struct pvt *)this->private;
        struct dns_p *dns = pvt->dns;

        return (__hesiod_res_get(dns->hes_ctx));
}

static void
pr_res_set(struct irs_pr *this, struct __res_state * res,
           void (*free_res)(void *)) {
        struct pvt *pvt = (struct pvt *)this->private;
        struct dns_p *dns = pvt->dns;

        __hesiod_res_set(dns->hes_ctx, res, free_res);
}

/* Private. */

static struct protoent *
parse_hes_list(struct irs_pr *this, char **hes_list) {
        struct pvt *pvt = (struct pvt *)this->private;
        char *p, *cp, **cpp, **new;
        int num = 0;
        int max = 0;

        for (cpp = hes_list; *cpp; cpp++) {
                cp = *cpp;

                /* Strip away comments, if any. */
                if ((p = strchr(cp, '#')))
                        *p = 0;

                /* Skip blank lines. */
                p = cp;
                while (*p && !isspace((unsigned char)*p))
                        p++;
                if (!*p)
                        continue;

                /* OK, we've got a live one.  Let's parse it for real. */
                if (pvt->prbuf)
                        free(pvt->prbuf);
                pvt->prbuf = strdup(cp);

                p = pvt->prbuf;
                pvt->proto.p_name = p;
                while (*p && !isspace((unsigned char)*p))
                        p++;
                if (!*p)
                        continue;
                *p++ = '\0';

                pvt->proto.p_proto = atoi(p);
                while (*p && !isspace((unsigned char)*p))
                        p++;
                if (*p)
                        *p++ = '\0';

                while (*p) {
                        if ((num + 1) >= max || !pvt->proto.p_aliases) {
                                max += 10;
                                new = realloc(pvt->proto.p_aliases,
                                              max * sizeof(char *));
                                if (!new) {
                                        errno = ENOMEM;
                                        goto cleanup;
                                }
                                pvt->proto.p_aliases = new;
                        }
                        pvt->proto.p_aliases[num++] = p;
                        while (*p && !isspace((unsigned char)*p))
                                p++;
                        if (*p)
                                *p++ = '\0';
                }
                if (!pvt->proto.p_aliases)
                        pvt->proto.p_aliases = malloc(sizeof(char *));
                if (!pvt->proto.p_aliases)
                        goto cleanup;
                pvt->proto.p_aliases[num] = NULL;
                return (&pvt->proto);
        }

 cleanup:
        if (pvt->proto.p_aliases) {
                free(pvt->proto.p_aliases);
                pvt->proto.p_aliases = NULL;
        }
        if (pvt->prbuf) {
                free(pvt->prbuf);
                pvt->prbuf = NULL;
        }
        return (NULL);
}

/*! \file */