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

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

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

#include "port_after.h"

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

/* Definitions */

struct pvt {
        struct dns_p *          dns;
        struct servent          serv;
        char *                  svbuf;
        struct __res_state *    res;
        void                    (*free_res)(void *);
};

/* Forward. */

static void                     sv_close(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 struct servent *         sv_next(struct irs_sv *);
static void                     sv_rewind(struct irs_sv *);
static void                     sv_minimize(struct irs_sv *);
#ifdef SV_RES_SETGET
static struct __res_state *     sv_res_get(struct irs_sv *);
static void                     sv_res_set(struct irs_sv *,
                                           struct __res_state *,
                                           void (*)(void *));
#endif

static struct servent *         parse_hes_list(struct irs_sv *,
                                               char **, const char *);

/* Public */

struct irs_sv *
irs_dns_sv(struct irs_acc *this) {
        struct dns_p *dns = (struct dns_p *)this->private;
        struct irs_sv *sv;
        struct pvt *pvt;

        if (!dns || !dns->hes_ctx) {
                errno = ENODEV;
                return (NULL);
        }
        if (!(pvt = memget(sizeof *pvt))) {
                errno = ENOMEM;
                return (NULL);
        }
        memset(pvt, 0, sizeof *pvt);
        pvt->dns = dns;
        if (!(sv = memget(sizeof *sv))) {
                memput(pvt, sizeof *pvt);
                errno = ENOMEM;
                return (NULL);
        }
        memset(sv, 0x5e, sizeof *sv);
        sv->private = pvt;
        sv->byname = sv_byname;
        sv->byport = sv_byport;
        sv->next = sv_next;
        sv->rewind = sv_rewind;
        sv->close = sv_close;
        sv->minimize = sv_minimize;
#ifdef SV_RES_SETGET
        sv->res_get = sv_res_get;
        sv->res_set = sv_res_set;
#else
        sv->res_get = NULL; /*%< sv_res_get; */
        sv->res_set = NULL; /*%< sv_res_set; */
#endif
        return (sv);
}

/* Methods */

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

        if (pvt->serv.s_aliases)
                free(pvt->serv.s_aliases);
        if (pvt->svbuf)
                free(pvt->svbuf);

        if (pvt->res && pvt->free_res)
                (*pvt->free_res)(pvt->res);
        memput(pvt, sizeof *pvt);
        memput(this, sizeof *this);
}

static struct servent *
sv_byname(struct irs_sv *this, const char *name, const char *proto) {
        struct pvt *pvt = (struct pvt *)this->private;
        struct dns_p *dns = pvt->dns;
        struct servent *s;
        char **hes_list;

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

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

static struct servent *
sv_byport(struct irs_sv *this, int port, const char *proto) {
        struct pvt *pvt = (struct pvt *)this->private;
        struct dns_p *dns = pvt->dns;
        struct servent *s;
        char portstr[16];
        char **hes_list;

        sprintf(portstr, "%d", ntohs(port));
        if (!(hes_list = hesiod_resolve(dns->hes_ctx, portstr, "port")))
                return (NULL);

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

static struct servent *
sv_next(struct irs_sv *this) {
        UNUSED(this);
        errno = ENODEV;
        return (NULL);
}

static void
sv_rewind(struct irs_sv *this) {
        UNUSED(this);
        /* NOOP */
}

/* Private */

static struct servent *
parse_hes_list(struct irs_sv *this, char **hes_list, const char *proto) {
        struct pvt *pvt = (struct pvt *)this->private;
        char *p, *cp, **cpp, **new;
        int proto_len;
        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;

                /* Check to make sure the protocol matches. */
                p = cp;
                while (*p && !isspace((unsigned char)*p))
                        p++;
                if (!*p)
                        continue;
                if (proto) {
                     proto_len = strlen(proto);
                     if (strncasecmp(++p, proto, proto_len) != 0)
                          continue;
                     if (p[proto_len] && !isspace(p[proto_len]&0xff))
                          continue;
                }
                /* OK, we've got a live one.  Let's parse it for real. */
                if (pvt->svbuf)
                        free(pvt->svbuf);
                pvt->svbuf = strdup(cp);

                p = pvt->svbuf;
                pvt->serv.s_name = p;
                while (*p && !isspace(*p&0xff))
                        p++;
                if (!*p)
                        continue;
                *p++ = '\0';

                pvt->serv.s_proto = p;
                while (*p && !isspace(*p&0xff))
                        p++;
                if (!*p)
                        continue;
                *p++ = '\0';

                pvt->serv.s_port = htons((u_short) atoi(p));
                while (*p && !isspace(*p&0xff))
                        p++;
                if (*p)
                        *p++ = '\0';

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

 cleanup:
        if (pvt->serv.s_aliases) {
                free(pvt->serv.s_aliases);
                pvt->serv.s_aliases = NULL;
        }
        if (pvt->svbuf) {
                free(pvt->svbuf);
                pvt->svbuf = NULL;
        }
        return (NULL);
}

static void
sv_minimize(struct irs_sv *this) {
        UNUSED(this);
        /* NOOP */
}

#ifdef SV_RES_SETGET
static struct __res_state *
sv_res_get(struct irs_sv *this) {
        struct pvt *pvt = (struct pvt *)this->private;
        struct dns_p *dns = pvt->dns;

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

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 dns_p *dns = pvt->dns;

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

/*! \file */