view src/core/nginx.c @ 7054:e02555553d0b

Range filter: protect from total size overflows. The overflow can be used to circumvent the restriction on total size of ranges introduced in c2a91088b0c0 (1.1.2). Additionally, overflow allows producing ranges with negative start (such ranges can be created by using a suffix, "bytes=-100"; normally this results in 200 due to the total size check). These can result in the following errors in logs: [crit] ... pread() ... failed (22: Invalid argument) [alert] ... sendfile() failed (22: Invalid argument) When using cache, it can be also used to reveal cache file header. It is believed that there are no other negative effects, at least with standard nginx modules. In theory, this can also result in memory disclosure and/or segmentation faults if multiple ranges are allowed, and the response is returned in a single in-memory buffer. This never happens with standard nginx modules though, as well as known 3rd party modules. Fix is to properly protect from possible overflow when incrementing size.
author Maxim Dounin <mdounin@mdounin.ru>
date Tue, 11 Jul 2017 16:06:23 +0300
parents 97c99bb43737
children 69f9ee0342db
line wrap: on
line source


/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#include <ngx_config.h>
#include <ngx_core.h>
#include <nginx.h>


static void ngx_show_version_info(void);
static ngx_int_t ngx_add_inherited_sockets(ngx_cycle_t *cycle);
static void ngx_cleanup_environment(void *data);
static ngx_int_t ngx_get_options(int argc, char *const *argv);
static ngx_int_t ngx_process_options(ngx_cycle_t *cycle);
static ngx_int_t ngx_save_argv(ngx_cycle_t *cycle, int argc, char *const *argv);
static void *ngx_core_module_create_conf(ngx_cycle_t *cycle);
static char *ngx_core_module_init_conf(ngx_cycle_t *cycle, void *conf);
static char *ngx_set_user(ngx_conf_t *cf, ngx_command_t *cmd, void *conf);
static char *ngx_set_env(ngx_conf_t *cf, ngx_command_t *cmd, void *conf);
static char *ngx_set_priority(ngx_conf_t *cf, ngx_command_t *cmd, void *conf);
static char *ngx_set_cpu_affinity(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);
static char *ngx_set_worker_processes(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);
static char *ngx_load_module(ngx_conf_t *cf, ngx_command_t *cmd, void *conf);
#if (NGX_HAVE_DLOPEN)
static void ngx_unload_module(void *data);
#endif


static ngx_conf_enum_t  ngx_debug_points[] = {
    { ngx_string("stop"), NGX_DEBUG_POINTS_STOP },
    { ngx_string("abort"), NGX_DEBUG_POINTS_ABORT },
    { ngx_null_string, 0 }
};


static ngx_command_t  ngx_core_commands[] = {

    { ngx_string("daemon"),
      NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_FLAG,
      ngx_conf_set_flag_slot,
      0,
      offsetof(ngx_core_conf_t, daemon),
      NULL },

    { ngx_string("master_process"),
      NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_FLAG,
      ngx_conf_set_flag_slot,
      0,
      offsetof(ngx_core_conf_t, master),
      NULL },

    { ngx_string("timer_resolution"),
      NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_msec_slot,
      0,
      offsetof(ngx_core_conf_t, timer_resolution),
      NULL },

    { ngx_string("pid"),
      NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_str_slot,
      0,
      offsetof(ngx_core_conf_t, pid),
      NULL },

    { ngx_string("lock_file"),
      NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_str_slot,
      0,
      offsetof(ngx_core_conf_t, lock_file),
      NULL },

    { ngx_string("worker_processes"),
      NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
      ngx_set_worker_processes,
      0,
      0,
      NULL },

    { ngx_string("debug_points"),
      NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_enum_slot,
      0,
      offsetof(ngx_core_conf_t, debug_points),
      &ngx_debug_points },

    { ngx_string("user"),
      NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE12,
      ngx_set_user,
      0,
      0,
      NULL },

    { ngx_string("worker_priority"),
      NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
      ngx_set_priority,
      0,
      0,
      NULL },

    { ngx_string("worker_cpu_affinity"),
      NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_1MORE,
      ngx_set_cpu_affinity,
      0,
      0,
      NULL },

    { ngx_string("worker_rlimit_nofile"),
      NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_num_slot,
      0,
      offsetof(ngx_core_conf_t, rlimit_nofile),
      NULL },

    { ngx_string("worker_rlimit_core"),
      NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_off_slot,
      0,
      offsetof(ngx_core_conf_t, rlimit_core),
      NULL },

    { ngx_string("worker_shutdown_timeout"),
      NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_msec_slot,
      0,
      offsetof(ngx_core_conf_t, shutdown_timeout),
      NULL },

    { ngx_string("working_directory"),
      NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_str_slot,
      0,
      offsetof(ngx_core_conf_t, working_directory),
      NULL },

    { ngx_string("env"),
      NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
      ngx_set_env,
      0,
      0,
      NULL },

    { ngx_string("load_module"),
      NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
      ngx_load_module,
      0,
      0,
      NULL },

      ngx_null_command
};


static ngx_core_module_t  ngx_core_module_ctx = {
    ngx_string("core"),
    ngx_core_module_create_conf,
    ngx_core_module_init_conf
};


ngx_module_t  ngx_core_module = {
    NGX_MODULE_V1,
    &ngx_core_module_ctx,                  /* module context */
    ngx_core_commands,                     /* module directives */
    NGX_CORE_MODULE,                       /* module type */
    NULL,                                  /* init master */
    NULL,                                  /* init module */
    NULL,                                  /* init process */
    NULL,                                  /* init thread */
    NULL,                                  /* exit thread */
    NULL,                                  /* exit process */
    NULL,                                  /* exit master */
    NGX_MODULE_V1_PADDING
};


static ngx_uint_t   ngx_show_help;
static ngx_uint_t   ngx_show_version;
static ngx_uint_t   ngx_show_configure;
static u_char      *ngx_prefix;
static u_char      *ngx_conf_file;
static u_char      *ngx_conf_params;
static char        *ngx_signal;


static char **ngx_os_environ;


int ngx_cdecl
main(int argc, char *const *argv)
{
    ngx_buf_t        *b;
    ngx_log_t        *log;
    ngx_uint_t        i;
    ngx_cycle_t      *cycle, init_cycle;
    ngx_conf_dump_t  *cd;
    ngx_core_conf_t  *ccf;

    ngx_debug_init();

    if (ngx_strerror_init() != NGX_OK) {
        return 1;
    }

    if (ngx_get_options(argc, argv) != NGX_OK) {
        return 1;
    }

    if (ngx_show_version) {
        ngx_show_version_info();

        if (!ngx_test_config) {
            return 0;
        }
    }

    /* TODO */ ngx_max_sockets = -1;

    ngx_time_init();

#if (NGX_PCRE)
    ngx_regex_init();
#endif

    ngx_pid = ngx_getpid();

    log = ngx_log_init(ngx_prefix);
    if (log == NULL) {
        return 1;
    }

    /* STUB */
#if (NGX_OPENSSL)
    ngx_ssl_init(log);
#endif

    /*
     * init_cycle->log is required for signal handlers and
     * ngx_process_options()
     */

    ngx_memzero(&init_cycle, sizeof(ngx_cycle_t));
    init_cycle.log = log;
    ngx_cycle = &init_cycle;

    init_cycle.pool = ngx_create_pool(1024, log);
    if (init_cycle.pool == NULL) {
        return 1;
    }

    if (ngx_save_argv(&init_cycle, argc, argv) != NGX_OK) {
        return 1;
    }

    if (ngx_process_options(&init_cycle) != NGX_OK) {
        return 1;
    }

    if (ngx_os_init(log) != NGX_OK) {
        return 1;
    }

    /*
     * ngx_crc32_table_init() requires ngx_cacheline_size set in ngx_os_init()
     */

    if (ngx_crc32_table_init() != NGX_OK) {
        return 1;
    }

    if (ngx_add_inherited_sockets(&init_cycle) != NGX_OK) {
        return 1;
    }

    if (ngx_preinit_modules() != NGX_OK) {
        return 1;
    }

    cycle = ngx_init_cycle(&init_cycle);
    if (cycle == NULL) {
        if (ngx_test_config) {
            ngx_log_stderr(0, "configuration file %s test failed",
                           init_cycle.conf_file.data);
        }

        return 1;
    }

    if (ngx_test_config) {
        if (!ngx_quiet_mode) {
            ngx_log_stderr(0, "configuration file %s test is successful",
                           cycle->conf_file.data);
        }

        if (ngx_dump_config) {
            cd = cycle->config_dump.elts;

            for (i = 0; i < cycle->config_dump.nelts; i++) {

                ngx_write_stdout("# configuration file ");
                (void) ngx_write_fd(ngx_stdout, cd[i].name.data,
                                    cd[i].name.len);
                ngx_write_stdout(":" NGX_LINEFEED);

                b = cd[i].buffer;

                (void) ngx_write_fd(ngx_stdout, b->pos, b->last - b->pos);
                ngx_write_stdout(NGX_LINEFEED);
            }
        }

        return 0;
    }

    if (ngx_signal) {
        return ngx_signal_process(cycle, ngx_signal);
    }

    ngx_os_status(cycle->log);

    ngx_cycle = cycle;

    ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);

    if (ccf->master && ngx_process == NGX_PROCESS_SINGLE) {
        ngx_process = NGX_PROCESS_MASTER;
    }

#if !(NGX_WIN32)

    if (ngx_init_signals(cycle->log) != NGX_OK) {
        return 1;
    }

    if (!ngx_inherited && ccf->daemon) {
        if (ngx_daemon(cycle->log) != NGX_OK) {
            return 1;
        }

        ngx_daemonized = 1;
    }

    if (ngx_inherited) {
        ngx_daemonized = 1;
    }

#endif

    if (ngx_create_pidfile(&ccf->pid, cycle->log) != NGX_OK) {
        return 1;
    }

    if (ngx_log_redirect_stderr(cycle) != NGX_OK) {
        return 1;
    }

    if (log->file->fd != ngx_stderr) {
        if (ngx_close_file(log->file->fd) == NGX_FILE_ERROR) {
            ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                          ngx_close_file_n " built-in log failed");
        }
    }

    ngx_use_stderr = 0;

    if (ngx_process == NGX_PROCESS_SINGLE) {
        ngx_single_process_cycle(cycle);

    } else {
        ngx_master_process_cycle(cycle);
    }

    return 0;
}


static void
ngx_show_version_info(void)
{
    ngx_write_stderr("nginx version: " NGINX_VER_BUILD NGX_LINEFEED);

    if (ngx_show_help) {
        ngx_write_stderr(
            "Usage: nginx [-?hvVtTq] [-s signal] [-c filename] "
                         "[-p prefix] [-g directives]" NGX_LINEFEED
                         NGX_LINEFEED
            "Options:" NGX_LINEFEED
            "  -?,-h         : this help" NGX_LINEFEED
            "  -v            : show version and exit" NGX_LINEFEED
            "  -V            : show version and configure options then exit"
                               NGX_LINEFEED
            "  -t            : test configuration and exit" NGX_LINEFEED
            "  -T            : test configuration, dump it and exit"
                               NGX_LINEFEED
            "  -q            : suppress non-error messages "
                               "during configuration testing" NGX_LINEFEED
            "  -s signal     : send signal to a master process: "
                               "stop, quit, reopen, reload" NGX_LINEFEED
#ifdef NGX_PREFIX
            "  -p prefix     : set prefix path (default: " NGX_PREFIX ")"
                               NGX_LINEFEED
#else
            "  -p prefix     : set prefix path (default: NONE)" NGX_LINEFEED
#endif
            "  -c filename   : set configuration file (default: " NGX_CONF_PATH
                               ")" NGX_LINEFEED
            "  -g directives : set global directives out of configuration "
                               "file" NGX_LINEFEED NGX_LINEFEED
        );
    }

    if (ngx_show_configure) {

#ifdef NGX_COMPILER
        ngx_write_stderr("built by " NGX_COMPILER NGX_LINEFEED);
#endif

#if (NGX_SSL)
        if (ngx_strcmp(ngx_ssl_version(), OPENSSL_VERSION_TEXT) == 0) {
            ngx_write_stderr("built with " OPENSSL_VERSION_TEXT NGX_LINEFEED);
        } else {
            ngx_write_stderr("built with " OPENSSL_VERSION_TEXT
                             " (running with ");
            ngx_write_stderr((char *) (uintptr_t) ngx_ssl_version());
            ngx_write_stderr(")" NGX_LINEFEED);
        }
#ifdef SSL_CTRL_SET_TLSEXT_HOSTNAME
        ngx_write_stderr("TLS SNI support enabled" NGX_LINEFEED);
#else
        ngx_write_stderr("TLS SNI support disabled" NGX_LINEFEED);
#endif
#endif

        ngx_write_stderr("configure arguments:" NGX_CONFIGURE NGX_LINEFEED);
    }
}


static ngx_int_t
ngx_add_inherited_sockets(ngx_cycle_t *cycle)
{
    u_char           *p, *v, *inherited;
    ngx_int_t         s;
    ngx_listening_t  *ls;

    inherited = (u_char *) getenv(NGINX_VAR);

    if (inherited == NULL) {
        return NGX_OK;
    }

    ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0,
                  "using inherited sockets from \"%s\"", inherited);

    if (ngx_array_init(&cycle->listening, cycle->pool, 10,
                       sizeof(ngx_listening_t))
        != NGX_OK)
    {
        return NGX_ERROR;
    }

    for (p = inherited, v = p; *p; p++) {
        if (*p == ':' || *p == ';') {
            s = ngx_atoi(v, p - v);
            if (s == NGX_ERROR) {
                ngx_log_error(NGX_LOG_EMERG, cycle->log, 0,
                              "invalid socket number \"%s\" in " NGINX_VAR
                              " environment variable, ignoring the rest"
                              " of the variable", v);
                break;
            }

            v = p + 1;

            ls = ngx_array_push(&cycle->listening);
            if (ls == NULL) {
                return NGX_ERROR;
            }

            ngx_memzero(ls, sizeof(ngx_listening_t));

            ls->fd = (ngx_socket_t) s;
        }
    }

    if (v != p) {
        ngx_log_error(NGX_LOG_EMERG, cycle->log, 0,
                      "invalid socket number \"%s\" in " NGINX_VAR
                      " environment variable, ignoring", v);
    }

    ngx_inherited = 1;

    return ngx_set_inherited_sockets(cycle);
}


char **
ngx_set_environment(ngx_cycle_t *cycle, ngx_uint_t *last)
{
    char                **p, **env;
    ngx_str_t            *var;
    ngx_uint_t            i, n;
    ngx_core_conf_t      *ccf;
    ngx_pool_cleanup_t   *cln;

    ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);

    if (last == NULL && ccf->environment) {
        return ccf->environment;
    }

    var = ccf->env.elts;

    for (i = 0; i < ccf->env.nelts; i++) {
        if (ngx_strcmp(var[i].data, "TZ") == 0
            || ngx_strncmp(var[i].data, "TZ=", 3) == 0)
        {
            goto tz_found;
        }
    }

    var = ngx_array_push(&ccf->env);
    if (var == NULL) {
        return NULL;
    }

    var->len = 2;
    var->data = (u_char *) "TZ";

    var = ccf->env.elts;

tz_found:

    n = 0;

    for (i = 0; i < ccf->env.nelts; i++) {

        if (var[i].data[var[i].len] == '=') {
            n++;
            continue;
        }

        for (p = ngx_os_environ; *p; p++) {

            if (ngx_strncmp(*p, var[i].data, var[i].len) == 0
                && (*p)[var[i].len] == '=')
            {
                n++;
                break;
            }
        }
    }

    if (last) {
        env = ngx_alloc((*last + n + 1) * sizeof(char *), cycle->log);
        if (env == NULL) {
            return NULL;
        }

        *last = n;

    } else {
        cln = ngx_pool_cleanup_add(cycle->pool, 0);
        if (cln == NULL) {
            return NULL;
        }

        env = ngx_alloc((n + 1) * sizeof(char *), cycle->log);
        if (env == NULL) {
            return NULL;
        }

        cln->handler = ngx_cleanup_environment;
        cln->data = env;
    }

    n = 0;

    for (i = 0; i < ccf->env.nelts; i++) {

        if (var[i].data[var[i].len] == '=') {
            env[n++] = (char *) var[i].data;
            continue;
        }

        for (p = ngx_os_environ; *p; p++) {

            if (ngx_strncmp(*p, var[i].data, var[i].len) == 0
                && (*p)[var[i].len] == '=')
            {
                env[n++] = *p;
                break;
            }
        }
    }

    env[n] = NULL;

    if (last == NULL) {
        ccf->environment = env;
        environ = env;
    }

    return env;
}


static void
ngx_cleanup_environment(void *data)
{
    char  **env = data;

    if (environ == env) {

        /*
         * if the environment is still used, as it happens on exit,
         * the only option is to leak it
         */

        return;
    }

    ngx_free(env);
}


ngx_pid_t
ngx_exec_new_binary(ngx_cycle_t *cycle, char *const *argv)
{
    char             **env, *var;
    u_char            *p;
    ngx_uint_t         i, n;
    ngx_pid_t          pid;
    ngx_exec_ctx_t     ctx;
    ngx_core_conf_t   *ccf;
    ngx_listening_t   *ls;

    ngx_memzero(&ctx, sizeof(ngx_exec_ctx_t));

    ctx.path = argv[0];
    ctx.name = "new binary process";
    ctx.argv = argv;

    n = 2;
    env = ngx_set_environment(cycle, &n);
    if (env == NULL) {
        return NGX_INVALID_PID;
    }

    var = ngx_alloc(sizeof(NGINX_VAR)
                    + cycle->listening.nelts * (NGX_INT32_LEN + 1) + 2,
                    cycle->log);
    if (var == NULL) {
        ngx_free(env);
        return NGX_INVALID_PID;
    }

    p = ngx_cpymem(var, NGINX_VAR "=", sizeof(NGINX_VAR));

    ls = cycle->listening.elts;
    for (i = 0; i < cycle->listening.nelts; i++) {
        p = ngx_sprintf(p, "%ud;", ls[i].fd);
    }

    *p = '\0';

    env[n++] = var;

#if (NGX_SETPROCTITLE_USES_ENV)

    /* allocate the spare 300 bytes for the new binary process title */

    env[n++] = "SPARE=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
               "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
               "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
               "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
               "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX";

#endif

    env[n] = NULL;

#if (NGX_DEBUG)
    {
    char  **e;
    for (e = env; *e; e++) {
        ngx_log_debug1(NGX_LOG_DEBUG_CORE, cycle->log, 0, "env: %s", *e);
    }
    }
#endif

    ctx.envp = (char *const *) env;

    ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);

    if (ngx_rename_file(ccf->pid.data, ccf->oldpid.data) == NGX_FILE_ERROR) {
        ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                      ngx_rename_file_n " %s to %s failed "
                      "before executing new binary process \"%s\"",
                      ccf->pid.data, ccf->oldpid.data, argv[0]);

        ngx_free(env);
        ngx_free(var);

        return NGX_INVALID_PID;
    }

    pid = ngx_execute(cycle, &ctx);

    if (pid == NGX_INVALID_PID) {
        if (ngx_rename_file(ccf->oldpid.data, ccf->pid.data)
            == NGX_FILE_ERROR)
        {
            ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                          ngx_rename_file_n " %s back to %s failed after "
                          "an attempt to execute new binary process \"%s\"",
                          ccf->oldpid.data, ccf->pid.data, argv[0]);
        }
    }

    ngx_free(env);
    ngx_free(var);

    return pid;
}


static ngx_int_t
ngx_get_options(int argc, char *const *argv)
{
    u_char     *p;
    ngx_int_t   i;

    for (i = 1; i < argc; i++) {

        p = (u_char *) argv[i];

        if (*p++ != '-') {
            ngx_log_stderr(0, "invalid option: \"%s\"", argv[i]);
            return NGX_ERROR;
        }

        while (*p) {

            switch (*p++) {

            case '?':
            case 'h':
                ngx_show_version = 1;
                ngx_show_help = 1;
                break;

            case 'v':
                ngx_show_version = 1;
                break;

            case 'V':
                ngx_show_version = 1;
                ngx_show_configure = 1;
                break;

            case 't':
                ngx_test_config = 1;
                break;

            case 'T':
                ngx_test_config = 1;
                ngx_dump_config = 1;
                break;

            case 'q':
                ngx_quiet_mode = 1;
                break;

            case 'p':
                if (*p) {
                    ngx_prefix = p;
                    goto next;
                }

                if (argv[++i]) {
                    ngx_prefix = (u_char *) argv[i];
                    goto next;
                }

                ngx_log_stderr(0, "option \"-p\" requires directory name");
                return NGX_ERROR;

            case 'c':
                if (*p) {
                    ngx_conf_file = p;
                    goto next;
                }

                if (argv[++i]) {
                    ngx_conf_file = (u_char *) argv[i];
                    goto next;
                }

                ngx_log_stderr(0, "option \"-c\" requires file name");
                return NGX_ERROR;

            case 'g':
                if (*p) {
                    ngx_conf_params = p;
                    goto next;
                }

                if (argv[++i]) {
                    ngx_conf_params = (u_char *) argv[i];
                    goto next;
                }

                ngx_log_stderr(0, "option \"-g\" requires parameter");
                return NGX_ERROR;

            case 's':
                if (*p) {
                    ngx_signal = (char *) p;

                } else if (argv[++i]) {
                    ngx_signal = argv[i];

                } else {
                    ngx_log_stderr(0, "option \"-s\" requires parameter");
                    return NGX_ERROR;
                }

                if (ngx_strcmp(ngx_signal, "stop") == 0
                    || ngx_strcmp(ngx_signal, "quit") == 0
                    || ngx_strcmp(ngx_signal, "reopen") == 0
                    || ngx_strcmp(ngx_signal, "reload") == 0)
                {
                    ngx_process = NGX_PROCESS_SIGNALLER;
                    goto next;
                }

                ngx_log_stderr(0, "invalid option: \"-s %s\"", ngx_signal);
                return NGX_ERROR;

            default:
                ngx_log_stderr(0, "invalid option: \"%c\"", *(p - 1));
                return NGX_ERROR;
            }
        }

    next:

        continue;
    }

    return NGX_OK;
}


static ngx_int_t
ngx_save_argv(ngx_cycle_t *cycle, int argc, char *const *argv)
{
#if (NGX_FREEBSD)

    ngx_os_argv = (char **) argv;
    ngx_argc = argc;
    ngx_argv = (char **) argv;

#else
    size_t     len;
    ngx_int_t  i;

    ngx_os_argv = (char **) argv;
    ngx_argc = argc;

    ngx_argv = ngx_alloc((argc + 1) * sizeof(char *), cycle->log);
    if (ngx_argv == NULL) {
        return NGX_ERROR;
    }

    for (i = 0; i < argc; i++) {
        len = ngx_strlen(argv[i]) + 1;

        ngx_argv[i] = ngx_alloc(len, cycle->log);
        if (ngx_argv[i] == NULL) {
            return NGX_ERROR;
        }

        (void) ngx_cpystrn((u_char *) ngx_argv[i], (u_char *) argv[i], len);
    }

    ngx_argv[i] = NULL;

#endif

    ngx_os_environ = environ;

    return NGX_OK;
}


static ngx_int_t
ngx_process_options(ngx_cycle_t *cycle)
{
    u_char  *p;
    size_t   len;

    if (ngx_prefix) {
        len = ngx_strlen(ngx_prefix);
        p = ngx_prefix;

        if (len && !ngx_path_separator(p[len - 1])) {
            p = ngx_pnalloc(cycle->pool, len + 1);
            if (p == NULL) {
                return NGX_ERROR;
            }

            ngx_memcpy(p, ngx_prefix, len);
            p[len++] = '/';
        }

        cycle->conf_prefix.len = len;
        cycle->conf_prefix.data = p;
        cycle->prefix.len = len;
        cycle->prefix.data = p;

    } else {

#ifndef NGX_PREFIX

        p = ngx_pnalloc(cycle->pool, NGX_MAX_PATH);
        if (p == NULL) {
            return NGX_ERROR;
        }

        if (ngx_getcwd(p, NGX_MAX_PATH) == 0) {
            ngx_log_stderr(ngx_errno, "[emerg]: " ngx_getcwd_n " failed");
            return NGX_ERROR;
        }

        len = ngx_strlen(p);

        p[len++] = '/';

        cycle->conf_prefix.len = len;
        cycle->conf_prefix.data = p;
        cycle->prefix.len = len;
        cycle->prefix.data = p;

#else

#ifdef NGX_CONF_PREFIX
        ngx_str_set(&cycle->conf_prefix, NGX_CONF_PREFIX);
#else
        ngx_str_set(&cycle->conf_prefix, NGX_PREFIX);
#endif
        ngx_str_set(&cycle->prefix, NGX_PREFIX);

#endif
    }

    if (ngx_conf_file) {
        cycle->conf_file.len = ngx_strlen(ngx_conf_file);
        cycle->conf_file.data = ngx_conf_file;

    } else {
        ngx_str_set(&cycle->conf_file, NGX_CONF_PATH);
    }

    if (ngx_conf_full_name(cycle, &cycle->conf_file, 0) != NGX_OK) {
        return NGX_ERROR;
    }

    for (p = cycle->conf_file.data + cycle->conf_file.len - 1;
         p > cycle->conf_file.data;
         p--)
    {
        if (ngx_path_separator(*p)) {
            cycle->conf_prefix.len = p - ngx_cycle->conf_file.data + 1;
            cycle->conf_prefix.data = ngx_cycle->conf_file.data;
            break;
        }
    }

    if (ngx_conf_params) {
        cycle->conf_param.len = ngx_strlen(ngx_conf_params);
        cycle->conf_param.data = ngx_conf_params;
    }

    if (ngx_test_config) {
        cycle->log->log_level = NGX_LOG_INFO;
    }

    return NGX_OK;
}


static void *
ngx_core_module_create_conf(ngx_cycle_t *cycle)
{
    ngx_core_conf_t  *ccf;

    ccf = ngx_pcalloc(cycle->pool, sizeof(ngx_core_conf_t));
    if (ccf == NULL) {
        return NULL;
    }

    /*
     * set by ngx_pcalloc()
     *
     *     ccf->pid = NULL;
     *     ccf->oldpid = NULL;
     *     ccf->priority = 0;
     *     ccf->cpu_affinity_auto = 0;
     *     ccf->cpu_affinity_n = 0;
     *     ccf->cpu_affinity = NULL;
     */

    ccf->daemon = NGX_CONF_UNSET;
    ccf->master = NGX_CONF_UNSET;
    ccf->timer_resolution = NGX_CONF_UNSET_MSEC;
    ccf->shutdown_timeout = NGX_CONF_UNSET_MSEC;

    ccf->worker_processes = NGX_CONF_UNSET;
    ccf->debug_points = NGX_CONF_UNSET;

    ccf->rlimit_nofile = NGX_CONF_UNSET;
    ccf->rlimit_core = NGX_CONF_UNSET;

    ccf->user = (ngx_uid_t) NGX_CONF_UNSET_UINT;
    ccf->group = (ngx_gid_t) NGX_CONF_UNSET_UINT;

    if (ngx_array_init(&ccf->env, cycle->pool, 1, sizeof(ngx_str_t))
        != NGX_OK)
    {
        return NULL;
    }

    return ccf;
}


static char *
ngx_core_module_init_conf(ngx_cycle_t *cycle, void *conf)
{
    ngx_core_conf_t  *ccf = conf;

    ngx_conf_init_value(ccf->daemon, 1);
    ngx_conf_init_value(ccf->master, 1);
    ngx_conf_init_msec_value(ccf->timer_resolution, 0);
    ngx_conf_init_msec_value(ccf->shutdown_timeout, 0);

    ngx_conf_init_value(ccf->worker_processes, 1);
    ngx_conf_init_value(ccf->debug_points, 0);

#if (NGX_HAVE_CPU_AFFINITY)

    if (!ccf->cpu_affinity_auto
        && ccf->cpu_affinity_n
        && ccf->cpu_affinity_n != 1
        && ccf->cpu_affinity_n != (ngx_uint_t) ccf->worker_processes)
    {
        ngx_log_error(NGX_LOG_WARN, cycle->log, 0,
                      "the number of \"worker_processes\" is not equal to "
                      "the number of \"worker_cpu_affinity\" masks, "
                      "using last mask for remaining worker processes");
    }

#endif


    if (ccf->pid.len == 0) {
        ngx_str_set(&ccf->pid, NGX_PID_PATH);
    }

    if (ngx_conf_full_name(cycle, &ccf->pid, 0) != NGX_OK) {
        return NGX_CONF_ERROR;
    }

    ccf->oldpid.len = ccf->pid.len + sizeof(NGX_OLDPID_EXT);

    ccf->oldpid.data = ngx_pnalloc(cycle->pool, ccf->oldpid.len);
    if (ccf->oldpid.data == NULL) {
        return NGX_CONF_ERROR;
    }

    ngx_memcpy(ngx_cpymem(ccf->oldpid.data, ccf->pid.data, ccf->pid.len),
               NGX_OLDPID_EXT, sizeof(NGX_OLDPID_EXT));


#if !(NGX_WIN32)

    if (ccf->user == (uid_t) NGX_CONF_UNSET_UINT && geteuid() == 0) {
        struct group   *grp;
        struct passwd  *pwd;

        ngx_set_errno(0);
        pwd = getpwnam(NGX_USER);
        if (pwd == NULL) {
            ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
                          "getpwnam(\"" NGX_USER "\") failed");
            return NGX_CONF_ERROR;
        }

        ccf->username = NGX_USER;
        ccf->user = pwd->pw_uid;

        ngx_set_errno(0);
        grp = getgrnam(NGX_GROUP);
        if (grp == NULL) {
            ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
                          "getgrnam(\"" NGX_GROUP "\") failed");
            return NGX_CONF_ERROR;
        }

        ccf->group = grp->gr_gid;
    }


    if (ccf->lock_file.len == 0) {
        ngx_str_set(&ccf->lock_file, NGX_LOCK_PATH);
    }

    if (ngx_conf_full_name(cycle, &ccf->lock_file, 0) != NGX_OK) {
        return NGX_CONF_ERROR;
    }

    {
    ngx_str_t  lock_file;

    lock_file = cycle->old_cycle->lock_file;

    if (lock_file.len) {
        lock_file.len--;

        if (ccf->lock_file.len != lock_file.len
            || ngx_strncmp(ccf->lock_file.data, lock_file.data, lock_file.len)
               != 0)
        {
            ngx_log_error(NGX_LOG_EMERG, cycle->log, 0,
                          "\"lock_file\" could not be changed, ignored");
        }

        cycle->lock_file.len = lock_file.len + 1;
        lock_file.len += sizeof(".accept");

        cycle->lock_file.data = ngx_pstrdup(cycle->pool, &lock_file);
        if (cycle->lock_file.data == NULL) {
            return NGX_CONF_ERROR;
        }

    } else {
        cycle->lock_file.len = ccf->lock_file.len + 1;
        cycle->lock_file.data = ngx_pnalloc(cycle->pool,
                                      ccf->lock_file.len + sizeof(".accept"));
        if (cycle->lock_file.data == NULL) {
            return NGX_CONF_ERROR;
        }

        ngx_memcpy(ngx_cpymem(cycle->lock_file.data, ccf->lock_file.data,
                              ccf->lock_file.len),
                   ".accept", sizeof(".accept"));
    }
    }

#endif

    return NGX_CONF_OK;
}


static char *
ngx_set_user(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
#if (NGX_WIN32)

    ngx_conf_log_error(NGX_LOG_WARN, cf, 0,
                       "\"user\" is not supported, ignored");

    return NGX_CONF_OK;

#else

    ngx_core_conf_t  *ccf = conf;

    char             *group;
    struct passwd    *pwd;
    struct group     *grp;
    ngx_str_t        *value;

    if (ccf->user != (uid_t) NGX_CONF_UNSET_UINT) {
        return "is duplicate";
    }

    if (geteuid() != 0) {
        ngx_conf_log_error(NGX_LOG_WARN, cf, 0,
                           "the \"user\" directive makes sense only "
                           "if the master process runs "
                           "with super-user privileges, ignored");
        return NGX_CONF_OK;
    }

    value = cf->args->elts;

    ccf->username = (char *) value[1].data;

    ngx_set_errno(0);
    pwd = getpwnam((const char *) value[1].data);
    if (pwd == NULL) {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, ngx_errno,
                           "getpwnam(\"%s\") failed", value[1].data);
        return NGX_CONF_ERROR;
    }

    ccf->user = pwd->pw_uid;

    group = (char *) ((cf->args->nelts == 2) ? value[1].data : value[2].data);

    ngx_set_errno(0);
    grp = getgrnam(group);
    if (grp == NULL) {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, ngx_errno,
                           "getgrnam(\"%s\") failed", group);
        return NGX_CONF_ERROR;
    }

    ccf->group = grp->gr_gid;

    return NGX_CONF_OK;

#endif
}


static char *
ngx_set_env(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_core_conf_t  *ccf = conf;

    ngx_str_t   *value, *var;
    ngx_uint_t   i;

    var = ngx_array_push(&ccf->env);
    if (var == NULL) {
        return NGX_CONF_ERROR;
    }

    value = cf->args->elts;
    *var = value[1];

    for (i = 0; i < value[1].len; i++) {

        if (value[1].data[i] == '=') {

            var->len = i;

            return NGX_CONF_OK;
        }
    }

    return NGX_CONF_OK;
}


static char *
ngx_set_priority(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_core_conf_t  *ccf = conf;

    ngx_str_t        *value;
    ngx_uint_t        n, minus;

    if (ccf->priority != 0) {
        return "is duplicate";
    }

    value = cf->args->elts;

    if (value[1].data[0] == '-') {
        n = 1;
        minus = 1;

    } else if (value[1].data[0] == '+') {
        n = 1;
        minus = 0;

    } else {
        n = 0;
        minus = 0;
    }

    ccf->priority = ngx_atoi(&value[1].data[n], value[1].len - n);
    if (ccf->priority == NGX_ERROR) {
        return "invalid number";
    }

    if (minus) {
        ccf->priority = -ccf->priority;
    }

    return NGX_CONF_OK;
}


static char *
ngx_set_cpu_affinity(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
#if (NGX_HAVE_CPU_AFFINITY)
    ngx_core_conf_t  *ccf = conf;

    u_char            ch, *p;
    ngx_str_t        *value;
    ngx_uint_t        i, n;
    ngx_cpuset_t     *mask;

    if (ccf->cpu_affinity) {
        return "is duplicate";
    }

    mask = ngx_palloc(cf->pool, (cf->args->nelts - 1) * sizeof(ngx_cpuset_t));
    if (mask == NULL) {
        return NGX_CONF_ERROR;
    }

    ccf->cpu_affinity_n = cf->args->nelts - 1;
    ccf->cpu_affinity = mask;

    value = cf->args->elts;

    if (ngx_strcmp(value[1].data, "auto") == 0) {

        if (cf->args->nelts > 3) {
            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                               "invalid number of arguments in "
                               "\"worker_cpu_affinity\" directive");
            return NGX_CONF_ERROR;
        }

        ccf->cpu_affinity_auto = 1;

        CPU_ZERO(&mask[0]);
        for (i = 0; i < (ngx_uint_t) ngx_min(ngx_ncpu, CPU_SETSIZE); i++) {
            CPU_SET(i, &mask[0]);
        }

        n = 2;

    } else {
        n = 1;
    }

    for ( /* void */ ; n < cf->args->nelts; n++) {

        if (value[n].len > CPU_SETSIZE) {
            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                         "\"worker_cpu_affinity\" supports up to %d CPUs only",
                         CPU_SETSIZE);
            return NGX_CONF_ERROR;
        }

        i = 0;
        CPU_ZERO(&mask[n - 1]);

        for (p = value[n].data + value[n].len - 1;
             p >= value[n].data;
             p--)
        {
            ch = *p;

            if (ch == ' ') {
                continue;
            }

            i++;

            if (ch == '0') {
                continue;
            }

            if (ch == '1') {
                CPU_SET(i - 1, &mask[n - 1]);
                continue;
            }

            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                          "invalid character \"%c\" in \"worker_cpu_affinity\"",
                          ch);
            return NGX_CONF_ERROR;
        }
    }

#else

    ngx_conf_log_error(NGX_LOG_WARN, cf, 0,
                       "\"worker_cpu_affinity\" is not supported "
                       "on this platform, ignored");
#endif

    return NGX_CONF_OK;
}


ngx_cpuset_t *
ngx_get_cpu_affinity(ngx_uint_t n)
{
#if (NGX_HAVE_CPU_AFFINITY)
    ngx_uint_t        i, j;
    ngx_cpuset_t     *mask;
    ngx_core_conf_t  *ccf;

    static ngx_cpuset_t  result;

    ccf = (ngx_core_conf_t *) ngx_get_conf(ngx_cycle->conf_ctx,
                                           ngx_core_module);

    if (ccf->cpu_affinity == NULL) {
        return NULL;
    }

    if (ccf->cpu_affinity_auto) {
        mask = &ccf->cpu_affinity[ccf->cpu_affinity_n - 1];

        for (i = 0, j = n; /* void */ ; i++) {

            if (CPU_ISSET(i % CPU_SETSIZE, mask) && j-- == 0) {
                break;
            }

            if (i == CPU_SETSIZE && j == n) {
                /* empty mask */
                return NULL;
            }

            /* void */
        }

        CPU_ZERO(&result);
        CPU_SET(i % CPU_SETSIZE, &result);

        return &result;
    }

    if (ccf->cpu_affinity_n > n) {
        return &ccf->cpu_affinity[n];
    }

    return &ccf->cpu_affinity[ccf->cpu_affinity_n - 1];

#else

    return NULL;

#endif
}


static char *
ngx_set_worker_processes(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_str_t        *value;
    ngx_core_conf_t  *ccf;

    ccf = (ngx_core_conf_t *) conf;

    if (ccf->worker_processes != NGX_CONF_UNSET) {
        return "is duplicate";
    }

    value = cf->args->elts;

    if (ngx_strcmp(value[1].data, "auto") == 0) {
        ccf->worker_processes = ngx_ncpu;
        return NGX_CONF_OK;
    }

    ccf->worker_processes = ngx_atoi(value[1].data, value[1].len);

    if (ccf->worker_processes == NGX_ERROR) {
        return "invalid value";
    }

    return NGX_CONF_OK;
}


static char *
ngx_load_module(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
#if (NGX_HAVE_DLOPEN)
    void                *handle;
    char               **names, **order;
    ngx_str_t           *value, file;
    ngx_uint_t           i;
    ngx_module_t        *module, **modules;
    ngx_pool_cleanup_t  *cln;

    if (cf->cycle->modules_used) {
        return "is specified too late";
    }

    value = cf->args->elts;

    file = value[1];

    if (ngx_conf_full_name(cf->cycle, &file, 0) != NGX_OK) {
        return NGX_CONF_ERROR;
    }

    cln = ngx_pool_cleanup_add(cf->cycle->pool, 0);
    if (cln == NULL) {
        return NGX_CONF_ERROR;
    }

    handle = ngx_dlopen(file.data);
    if (handle == NULL) {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           ngx_dlopen_n " \"%s\" failed (%s)",
                           file.data, ngx_dlerror());
        return NGX_CONF_ERROR;
    }

    cln->handler = ngx_unload_module;
    cln->data = handle;

    modules = ngx_dlsym(handle, "ngx_modules");
    if (modules == NULL) {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           ngx_dlsym_n " \"%V\", \"%s\" failed (%s)",
                           &value[1], "ngx_modules", ngx_dlerror());
        return NGX_CONF_ERROR;
    }

    names = ngx_dlsym(handle, "ngx_module_names");
    if (names == NULL) {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           ngx_dlsym_n " \"%V\", \"%s\" failed (%s)",
                           &value[1], "ngx_module_names", ngx_dlerror());
        return NGX_CONF_ERROR;
    }

    order = ngx_dlsym(handle, "ngx_module_order");

    for (i = 0; modules[i]; i++) {
        module = modules[i];
        module->name = names[i];

        if (ngx_add_module(cf, &file, module, order) != NGX_OK) {
            return NGX_CONF_ERROR;
        }

        ngx_log_debug2(NGX_LOG_DEBUG_CORE, cf->log, 0, "module: %s i:%ui",
                       module->name, module->index);
    }

    return NGX_CONF_OK;

#else

    ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                       "\"load_module\" is not supported "
                       "on this platform");
    return NGX_CONF_ERROR;

#endif
}


#if (NGX_HAVE_DLOPEN)

static void
ngx_unload_module(void *data)
{
    void  *handle = data;

    if (ngx_dlclose(handle) != 0) {
        ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, 0,
                      ngx_dlclose_n " failed (%s)", ngx_dlerror());
    }
}

#endif