/** BEGIN COPYRIGHT BLOCK
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * Additional permission under GPLv3 section 7:
 *
 * In the following paragraph, "GPL" means the GNU General Public
 * License, version 3 or any later version, and "Non-GPL Code" means
 * code that is governed neither by the GPL nor a license
 * compatible with the GPL.
 *
 * You may link the code of this Program with Non-GPL Code and convey
 * linked combinations including the two, provided that such Non-GPL
 * Code only links to the code of this Program through those well
 * defined interfaces identified in the file named EXCEPTION found in
 * the source code files (the "Approved Interfaces"). The files of
 * Non-GPL Code may instantiate templates or use macros or inline
 * functions from the Approved Interfaces without causing the resulting
 * work to be covered by the GPL. Only the copyright holders of this
 * Program may make changes or additions to the list of Approved
 * Interfaces.
 *
 * Authors:
 * Simo Sorce <ssorce@redhat.com>
 *
 * Copyright (C) 2011 Red Hat, Inc.
 * All rights reserved.
 * END COPYRIGHT BLOCK **/

#include "ipa_cldap.h"
#include "util.h"

Slapi_PluginDesc ipa_cldap_desc = {
    IPA_CLDAP_PLUGIN_NAME,
    "FreeIPA project",
    "FreeIPA/3.0",
    IPA_CLDAP_PLUGIN_DESC
};

static int ipa_cldap_start(Slapi_PBlock *pb)
{
    struct ipa_cldap_ctx *ctx;
    int ret;

    ret = slapi_pblock_get(pb, SLAPI_PLUGIN_PRIVATE, &ctx);
    if (ret) {
        LOG_FATAL("No plugin context ?!\n");
        return -1;
    }

    ret = pthread_create(&ctx->tid, NULL, ipa_cldap_worker, ctx);
    if (ret) {
        LOG_FATAL("Failed to create worker thread\n");
        return -1;
    }

    LOG("Plugin statrup completed.\n");

    return 0;
}

static int ipa_cldap_stop(Slapi_PBlock *pb)
{
    struct ipa_cldap_ctx *ctx;
    void *retval;
    int ret;

    ret = slapi_pblock_get(pb, SLAPI_PLUGIN_PRIVATE, &ctx);
    if (ret) {
        LOG_FATAL("No plugin context ?!\n");
        return -1;
    }

    /* send stop signal to terminate worker thread */
    do {
        ret = write(ctx->stopfd[1], "", 1);
    } while (ret == -1 && errno == EINTR);
    close(ctx->stopfd[1]);

    ret = pthread_join(ctx->tid, &retval);
    if (ret) {
        LOG_FATAL("Failed to stop worker thread\n");
        return -1;
    }

    LOG("Plugin shutdown completed.\n");

    return 0;
}

static int ipa_cldap_init_service(Slapi_PBlock *pb,
                                  struct ipa_cldap_ctx **cldap_ctx)
{
    struct ipa_cldap_ctx *ctx;
    struct sockaddr_in6 addr;
    Slapi_Entry *e;
    int flags;
    int val;
    int ret;

    ctx = calloc(1, sizeof(struct ipa_cldap_ctx));
    if (!ctx) {
        return ENOMEM;
    }
    ctx->sd = -1;

    ret = slapi_pblock_get(pb, SLAPI_PLUGIN_IDENTITY, &ctx->plugin_id);
    if ((ret != 0) || (NULL == ctx->plugin_id)) {
        LOG_FATAL("Could not get identity or identity was NULL\n");
        if (ret == 0) {
            ret = -1;
        }
        goto done;
    }

    slapi_pblock_get(pb, SLAPI_PLUGIN_CONFIG_ENTRY, &e);
    if (!e) {
        LOG_FATAL("Plugin configuration not found!\n");
        ret = -1;
        goto done;
    }

    ctx->base_dn = slapi_entry_attr_get_charptr(e, "nsslapd-basedn");
    if (!ctx->base_dn) {
        LOG_FATAL("Plugin configuration not found!\n");
        ret = -1;
        goto done;
    }

    /* create a stop pipe so the main DS thread can interrupt the poll()
     * of the worker thread at any time and cause the worker thread to
     * immediately exit without waiting for timeouts or such */
    ret = pipe(ctx->stopfd);
    if (ret != 0) {
        LOG_FATAL("Failed to stop pipe\n");
        ret = EIO;
        goto done;
    }

    ctx->sd = socket(PF_INET6, SOCK_DGRAM, 0);
    if (ctx->sd == -1) {
        LOG_FATAL("Failed to create IPv6 socket: IPv6 support in kernel "
                  "is required\n");
        ret = EIO;
        goto done;
    }

    val = 1;
    ret = setsockopt(ctx->sd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
    if (ret == -1) {
        ret = errno;
        LOG("Failed to make socket immediately reusable (%d, %s)\n",
            ret, strerror(ret));
    }

    memset(&addr, 0, sizeof(addr));
    addr.sin6_family = AF_INET6;
    addr.sin6_port = htons(CLDAP_PORT);

    ret = bind(ctx->sd, (struct sockaddr *)&addr, sizeof(addr));
    if (ret == -1) {
        ret = errno;
        LOG_FATAL("Failed to bind socket (%d, %s)\n", ret, strerror(ret));
        goto done;
    }

    flags = fcntl(ctx->sd, F_GETFL);
    if ((flags & O_NONBLOCK) == 0) {
        ret = fcntl(ctx->sd, F_SETFL, flags | O_NONBLOCK);
        if (ret == -1) {
            ret = errno;
            LOG_FATAL("Failed to set socket to non-blocking\n");
            goto done;
        }
    }

done:
    if (ret) {
        if (ctx->sd != -1) {
            close(ctx->sd);
        }
        free(ctx);
    } else {
        *cldap_ctx = ctx;
    }
    return ret;
}

static int ipa_cldap_post_init(Slapi_PBlock *pb)
{
    return 0;
}

/* Initialization function */
int ipa_cldap_init(Slapi_PBlock *pb)
{
    struct ipa_cldap_ctx *cldap_ctx = NULL;
    int ret;

    ret = ipa_cldap_init_service(pb, &cldap_ctx);
    if (ret) {
        LOG_FATAL("Failed to initialize CLDAP Plugin\n");
        /* do not cause DS to stop, simply do nothing */
        return 0;
    }

    /* Register the plug-in */
    ret = slapi_pblock_set(pb, SLAPI_PLUGIN_VERSION, SLAPI_PLUGIN_VERSION_03);
    if (!ret) {
        ret = slapi_pblock_set(pb, SLAPI_PLUGIN_DESCRIPTION, &ipa_cldap_desc);
    }
    if (!ret) {
        ret = slapi_pblock_set(pb, SLAPI_PLUGIN_START_FN, &ipa_cldap_start);
    }
    if (!ret) {
        ret = slapi_pblock_set(pb, SLAPI_PLUGIN_CLOSE_FN, &ipa_cldap_stop);
    }
    if (!ret) {
        ret = slapi_pblock_set(pb, SLAPI_PLUGIN_PRIVATE, cldap_ctx);
    }
    if (ret) {
        LOG_FATAL("Failed to initialize plug-in\n" );
        return -1;
    }

    slapi_register_plugin("postoperation", 1,
                          "ipa_cldap_post_init",
                          ipa_cldap_post_init,
                          "CLDAP post ops", NULL,
                          cldap_ctx->plugin_id);

    return 0;
}