/* Licensed to the Apache Software Foundation (ASF) under one or more

 * contributor license agreements.  See the NOTICE file distributed with

 * this work for additional information regarding copyright ownership.

 * The ASF licenses this file to You under the Apache License, Version 2.0

 * (the "License"); you may not use this file except in compliance with

 * the License.  You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

#include <apr.h>

#include <apr_pools.h>

#include <apr_network_io.h>

#include <apr_thread_proc.h>

#include <apr_getopt.h>

#include <apr_portable.h>

#if APR_HAVE_STDLIB_H

#include <stdlib.h> /* For EXIT_SUCCESS, EXIT_FAILURE */

#endif

#if APR_HAVE_UNISTD_H

#include <unistd.h> /* For execl */

#endif

static const char *usage_message =

    "usage: fcgistarter -c <command> -p <port> [-i <interface> -N <num>]\n"

    "\n"

    "If an interface is not specified, any available will be used.\n";

static void usage(void)

{

    fprintf(stderr, "%s", usage_message);

    exit(EXIT_FAILURE);

}

static void exit_error(apr_status_t rv, const char *func)

{

    char buffer[1024];

    fprintf(stderr,

            "%s: %s\n",

            func,

            apr_strerror(rv, buffer, sizeof(buffer)));

    exit(EXIT_FAILURE);

}

int main(int argc, const char * const argv[])

{

    apr_file_t *infd, *skwrapper;

    apr_sockaddr_t *skaddr;

    apr_getopt_t *gopt;

    apr_socket_t *skt;

    apr_pool_t *pool;

    apr_status_t rv;

    apr_proc_t proc;

    /* Command line arguments */

    int num_to_start = 1, port = 0;

    const char *interface = NULL;

    const char *command = NULL;

    apr_app_initialize(&argc, &argv, NULL);

    atexit(apr_terminate);

    apr_pool_create(&pool, NULL);

    rv = apr_getopt_init(&gopt, pool, argc, argv);

    if (rv) {

        return EXIT_FAILURE;

    }

    for (;;) {

        const char *arg;

        char opt;

        rv = apr_getopt(gopt, "c:p:i:N:", &opt, &arg;;

        if (APR_STATUS_IS_EOF(rv)) {

            break;

        } else if (rv) {

            usage();

        } else {

            switch (opt) {

            case 'c':

                command = arg;

                break;

            case 'p':

                port = atoi(arg);

                if (! port) {

                    usage();

                }

                break;

            case 'i':

                interface = arg;

                break;

            case 'N':

                num_to_start = atoi(arg);

                if (! num_to_start) {

                    usage();

                }

                break;

            default:

                break;

            }

        }

    }

    if (! command || ! port) {

        usage();

    }

    rv = apr_sockaddr_info_get(&skaddr, interface, APR_UNSPEC, port, 0, pool);

    if (rv) {

        exit_error(rv, "apr_sockaddr_info_get");

    }

    rv = apr_socket_create(&skt, skaddr->family, SOCK_STREAM, APR_PROTO_TCP, pool);

    if (rv) {

        exit_error(rv, "apr_socket_create");

    }

    rv = apr_socket_opt_set(skt, APR_SO_REUSEADDR, 1);

    if (rv) {

        exit_error(rv, "apr_socket_opt_set(APR_SO_REUSEADDR)");

    }

    rv = apr_socket_bind(skt, skaddr);

    if (rv) {

        exit_error(rv, "apr_socket_bind");

    }

    rv = apr_socket_listen(skt, 1024);

    if (rv) {

        exit_error(rv, "apr_socket_listen");

    }

    rv = apr_proc_detach(APR_PROC_DETACH_DAEMONIZE);

    if (rv) {

        exit_error(rv, "apr_proc_detach");

    }

#if defined(WIN32) || defined(OS2) || defined(NETWARE)

#error "Please implement me."

#else

    while (--num_to_start >= 0) {

        rv = apr_proc_fork(&proc, pool);

        if (rv == APR_INCHILD) {

            apr_os_file_t oft = 0;

            apr_os_sock_t oskt;

            /* Ok, so we need a file that has file descriptor 0 (which

             * FastCGI wants), but points to our socket.  This isn't really

             * possible in APR, so we cheat a bit.  I have no idea how to

             * do this on a non-unix platform, so for now this is platform

             * specific.  Ick.

             *

             * Note that this has to happen post-detach, otherwise fd 0

             * gets closed during apr_proc_detach and it's all for nothing.

             *

             * Unfortunately, doing this post detach means we have no way

             * to let anyone know if there's a problem at this point :( */

            rv = apr_os_file_put(&infd, &oft, APR_READ | APR_WRITE, pool);

            if (rv) {

                exit(EXIT_FAILURE);

            }

            rv = apr_os_sock_get(&oskt, skt);

            if (rv) {

                exit(EXIT_FAILURE);

            }

            rv = apr_os_file_put(&skwrapper, &oskt, APR_READ | APR_WRITE,

                                 pool);

            if (rv) {

                exit(EXIT_FAILURE);

            }

            rv = apr_file_dup2(infd, skwrapper, pool);

            if (rv) {

                exit(EXIT_FAILURE);

            }

            /* XXX Can't use apr_proc_create because there's no way to get

             *     infd into the procattr without going through another dup2,

             *     which means by the time it gets to the fastcgi process it

             *     is no longer fd 0, so it doesn't work.  Sigh. */

            execl(command, command, NULL);

        } else if (rv == APR_INPARENT) {

            if (num_to_start == 0) {

                apr_socket_close(skt);

            }

        } else {

            exit_error(rv, "apr_proc_fork");

        }

    }

#endif

    return EXIT_SUCCESS;

}