/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */

/*

 * Copyright (C) 2008 Imendio AB

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public License as

 * published by the Free Software Foundation; either version 2 of the

 * License, or (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this program; if not, see <https://www.gnu.org/licenses>

 */

#include <config.h>

#include <string.h>

#ifdef HAVE_ASYNCNS

#include <asyncns.h>

#define freeaddrinfo(x) asyncns_freeaddrinfo(x)

/* Needed on Mac OS X */

#if HAVE_ARPA_NAMESER_COMPAT_H

#include <arpa/nameser_compat.h>

#endif

#include <arpa/nameser.h>

#include <resolv.h>

#include "lm-debug.h"

#include "lm-error.h"

#include "lm-internals.h"

#include "lm-marshal.h"

#include "lm-misc.h"

#include "lm-asyncns-resolver.h"

    GSource     *watch_resolv;

    asyncns_query_t *resolv_query;

    asyncns_t   *asyncns_ctx;

    GIOChannel  *resolv_channel;

};

static void     asyncns_resolver_dispose       (GObject     *object);

static void     asyncns_resolver_lookup        (LmResolver  *resolver);

static void     asyncns_resolver_cleanup       (LmResolver  *resolver);

static void     asyncns_resolver_cancel        (LmResolver  *resolver);

static void

lm_asyncns_resolver_class_init (LmAsyncnsResolverClass *class)

{

    GObjectClass    *object_class = G_OBJECT_CLASS (class);

    LmResolverClass *resolver_class = LM_RESOLVER_CLASS (class);

    object_class->dispose = asyncns_resolver_dispose;

    resolver_class->lookup = asyncns_resolver_lookup;

    resolver_class->cancel = asyncns_resolver_cancel;

}

static void

lm_asyncns_resolver_init (LmAsyncnsResolver *asyncns_resolver)

{

}

static void

asyncns_resolver_dispose (GObject *object)

{

    g_return_if_fail (LM_IS_ASYNCNS_RESOLVER (object));

    asyncns_resolver_cleanup (LM_RESOLVER(object));

    (G_OBJECT_CLASS (lm_asyncns_resolver_parent_class)->dispose) (object);

}

static void

asyncns_resolver_cleanup (LmResolver *resolver)

{

    if (priv->resolv_channel != NULL) {

        g_io_channel_unref (priv->resolv_channel);

        priv->resolv_channel = NULL;

    }

    if (priv->watch_resolv) {

        g_source_destroy (priv->watch_resolv);

        priv->watch_resolv = NULL;

    }

    if (priv->asyncns_ctx) {

        asyncns_free (priv->asyncns_ctx);

        priv->asyncns_ctx = NULL;

    }

    priv->resolv_query = NULL;

}

static void

asyncns_resolver_done (LmResolver *resolver)

{

    struct addrinfo       *ans;

    int                err;

    err = asyncns_getaddrinfo_done (priv->asyncns_ctx, priv->resolv_query, &ans);

    priv->resolv_query = NULL;

    /* Signal that we are done */

    g_object_ref (resolver);

    if (err) {

        _lm_resolver_set_result (resolver,

                                 LM_RESOLVER_RESULT_FAILED,

                                 NULL);

    } else {

        _lm_resolver_set_result (resolver,

                                 LM_RESOLVER_RESULT_OK,

                                 ans);

    }

    asyncns_resolver_cleanup (resolver);

    g_object_unref (resolver);

}

typedef gboolean  (* LmAsyncnsResolverCallback) (LmResolver *resolver);

static gboolean

asyncns_resolver_io_cb (GSource      *source,

                        GIOCondition  condition,

                        LmResolver   *resolver)

{

    LmAsyncnsResolverCallback  func;

    asyncns_wait (priv->asyncns_ctx, FALSE);

    if (!asyncns_isdone (priv->asyncns_ctx, priv->resolv_query)) {

        return TRUE;

    }

    func = (LmAsyncnsResolverCallback) asyncns_getuserdata (priv->asyncns_ctx,

                                                            priv->resolv_query);

    return func (resolver);

}

static gboolean

asyncns_resolver_prep (LmResolver *resolver, GError **error)

{

    GMainContext          *context;

    if (priv->asyncns_ctx) {

        return TRUE;

    }

    priv->asyncns_ctx = asyncns_new (1);

    if (priv->asyncns_ctx == NULL) {

        g_set_error (error,

                     LM_ERROR,

                     LM_ERROR_CONNECTION_FAILED,

                     "can't initialise libasyncns");

        return FALSE;

    }

    priv->resolv_channel =

        g_io_channel_unix_new (asyncns_fd (priv->asyncns_ctx));

    g_object_get (resolver, "context", &context, NULL);

    priv->watch_resolv =

        lm_misc_add_io_watch (context,

                              priv->resolv_channel,

                              G_IO_IN,

                              (GIOFunc) asyncns_resolver_io_cb,

                              resolver);

    return TRUE;

}

static void

asyncns_resolver_lookup_host (LmResolver *resolver)

{

    gchar               *host;

    struct addrinfo      req;

    g_object_get (resolver, "host", &host, NULL);

    memset (&req, 0, sizeof(req));

    req.ai_family   = AF_UNSPEC;

    req.ai_socktype = SOCK_STREAM;

    req.ai_protocol = IPPROTO_TCP;

    if (!asyncns_resolver_prep (resolver, NULL)) {

        g_log (LM_LOG_DOMAIN, LM_LOG_LEVEL_NET, "Signal error\n");

        g_free (host);

        return;

    }

    priv->resolv_query =

        asyncns_getaddrinfo (priv->asyncns_ctx,

                             host,

                             NULL,

                             &req);

    asyncns_setuserdata (priv->asyncns_ctx,

                         priv->resolv_query,

                         (gpointer) asyncns_resolver_done);

    g_free (host);

}

static void

asyncns_resolver_srv_done (LmResolver *resolver)

{

    unsigned char         *srv_ans;

    int                    srv_len;

    gboolean               result = FALSE;

    g_log (LM_LOG_DOMAIN, LM_LOG_LEVEL_NET, "srv_done callback\n");

    srv_len = asyncns_res_done (priv->asyncns_ctx,

                                priv->resolv_query, &srv_ans);

    priv->resolv_query = NULL;

    if (srv_len <= 0) {

        /* FIXME: Report error */

        g_log (LM_LOG_DOMAIN, LM_LOG_LEVEL_NET,

               "Failed to read srv request results");

    } else {

        gchar *new_server;

        guint  new_port;

        g_log (LM_LOG_DOMAIN, LM_LOG_LEVEL_NET,

               "trying to parse srv response\n");

        result = _lm_resolver_parse_srv_response (srv_ans, srv_len,

                                                  &new_server,

                                                  &new_port);

        if (result == TRUE) {

            g_log (LM_LOG_DOMAIN, LM_LOG_LEVEL_NET,

                   "worked, new host/post is %s/%d\n",

                   new_server, new_port);

            g_object_set (resolver,

                          "host", new_server,

                          "port", new_port,

                          NULL);

            g_free (new_server);

        }

        /* TODO: Check whether srv_ans needs freeing */

    }

    asyncns_resolver_cleanup (resolver);

    g_object_ref (resolver);

    if (result == TRUE) {

        _lm_resolver_set_result (LM_RESOLVER (resolver), LM_RESOLVER_RESULT_OK, NULL);

    } else {

        _lm_resolver_set_result (LM_RESOLVER (resolver), LM_RESOLVER_RESULT_FAILED, NULL);

    }

    g_object_unref (resolver);

}

static void

asyncns_resolver_lookup_service (LmResolver *resolver)

{

    gchar                 *domain;

    gchar                 *service;

    gchar                 *protocol;

    gchar                 *srv;

    g_object_get (resolver,

                  "domain", &domain,

                  "service", &service,

                  "protocol", &protocol,

                  NULL);

    srv = _lm_resolver_create_srv_string (domain, service, protocol);

    g_log (LM_LOG_DOMAIN, LM_LOG_LEVEL_NET,

           "ASYNCNS: Looking up service: %s %s %s [%s]\n",

           domain, service, protocol, srv);

    if (!asyncns_resolver_prep (resolver, /* Use GError? */ NULL)) {

        g_log (LM_LOG_DOMAIN, LM_LOG_LEVEL_NET,

               "Failed to initiate the asyncns library");

        /* FIXME: Signal error */

        g_free (srv);

        g_free (domain);

        g_free (service);

        g_free (protocol);

        return;

    }

    priv->resolv_query =

        asyncns_res_query (priv->asyncns_ctx, srv, C_IN, T_SRV);

    asyncns_setuserdata (priv->asyncns_ctx,

                         priv->resolv_query,

                         (gpointer) asyncns_resolver_srv_done);

    g_free (srv);

    g_free (domain);

    g_free (service);

    g_free (protocol);

}

static void

asyncns_resolver_lookup (LmResolver *resolver)

{

    gint type;

    /* Start the DNS querying */

    /* Decide if we are going to lookup a srv or host */

    g_object_get (resolver, "type", &type, NULL);

    switch (type) {

    case LM_RESOLVER_HOST:

        asyncns_resolver_lookup_host (resolver);

        break;

    case LM_RESOLVER_SRV:

        asyncns_resolver_lookup_service (resolver);

        break;

    };

    /* End of DNS querying */

}

static void

asyncns_resolver_cancel (LmResolver *resolver)

{

    g_return_if_fail (LM_IS_ASYNCNS_RESOLVER (resolver));

    priv = GET_PRIV (resolver);

    if (priv->asyncns_ctx) {

        if (priv->resolv_query) {

            asyncns_cancel (priv->asyncns_ctx, priv->resolv_query);

            priv->resolv_query = NULL;

        }

        _lm_resolver_set_result (resolver,

                                 LM_RESOLVER_RESULT_CANCELLED,

                                 NULL);

    }

}

#endif //HAVE_ASYNCNS