view src/core/nginx.c @ 6351:497d0cff8ace

Resolver: fixed use-after-free memory accesses with CNAME. When several requests were waiting for a response, then after getting a CNAME response only the last request's context had the name updated. Contexts of other requests had the wrong name. This name was used by ngx_resolve_name_done() to find the node to remove the request context from. When the name was wrong, the request could not be properly cancelled, its context was freed but stayed linked to the node's waiting list. This happened e.g. when the first request was aborted or timed out before the resolving completed. When it completed, this triggered a use-after-free memory access by calling ctx->handler of already freed request context. The bug manifests itself by "could not cancel <name> resolving" alerts in error_log. When a request was responded with a CNAME, the request context kept the pointer to the original node's rn->u.cname. If the original node expired before the resolving timed out or completed with an error, this would trigger a use-after-free memory access via ctx->name in ctx->handler(). The fix is to keep ctx->name unmodified. The name from context is no longer used by ngx_resolve_name_done(). Instead, we now keep the pointer to resolver node to which this request is linked. Keeping the original name intact also improves logging.
author Roman Arutyunyan <arut@nginx.com>
date Tue, 26 Jan 2016 16:46:59 +0300
parents 96c4297375bc
children 0f203a2af17c
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();
static ngx_int_t ngx_add_inherited_sockets(ngx_cycle_t *cycle);
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 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("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_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
};


ngx_uint_t          ngx_max_module;

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;
    }

    ngx_max_module = 0;
    for (i = 0; ngx_modules[i]; i++) {
        ngx_modules[i]->index = ngx_max_module++;
    }

    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()
{
    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 (SSLeay() == SSLEAY_VERSION_NUMBER) {
            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)
                             SSLeay_version(SSLEAY_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;
        }
    }

    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;

    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);
        *last = n;

    } else {
        env = ngx_palloc(cycle->pool, (n + 1) * sizeof(char *));
    }

    if (env == NULL) {
        return NULL;
    }

    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;
}


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->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_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;
    uint64_t         *mask;
    ngx_str_t        *value;
    ngx_uint_t        i, n;

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

    mask = ngx_palloc(cf->pool, (cf->args->nelts - 1) * sizeof(uint64_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;
        mask[0] = (uint64_t) -1 >> (64 - ngx_min(64, ngx_ncpu));
        n = 2;

    } else {
        n = 1;
    }

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

        if (value[n].len > 64) {
            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                         "\"worker_cpu_affinity\" supports up to 64 CPUs only");
            return NGX_CONF_ERROR;
        }

        mask[n - 1] = 0;

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

            ch = value[n].data[i];

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

            mask[n - 1] <<= 1;

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

            if (ch == '1') {
                mask[n - 1] |= 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;
}


uint64_t
ngx_get_cpu_affinity(ngx_uint_t n)
{
    uint64_t          mask;
    ngx_uint_t        i;
    ngx_core_conf_t  *ccf;

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

    if (ccf->cpu_affinity == NULL) {
        return 0;
    }

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

        if (mask == 0) {
            return 0;
        }

        for (i = 0; /* void */ ; i++) {
            if ((mask & ((uint64_t) 1 << (i % 64))) && n-- == 0) {
                break;
            }

            /* void */
        }

        return (uint64_t) 1 << (i % 64);
    }

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

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


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;
}