view src/os/unix/ngx_process_cycle.c @ 9189:fcec773dd249

QUIC: avoid partial expansion of PATH_CHALLENGE/PATH_RESPONSE. By default packets with these frames are expanded to 1200 bytes. Previously, if anti-amplification limit did not allow this expansion, it was limited to whatever size was allowed. However RFC 9000 clearly states no partial expansion should happen in both cases. Section 8.2.1. Initiating Path Validation: An endpoint MUST expand datagrams that contain a PATH_CHALLENGE frame to at least the smallest allowed maximum datagram size of 1200 bytes, unless the anti-amplification limit for the path does not permit sending a datagram of this size. Section 8.2.2. Path Validation Responses: An endpoint MUST expand datagrams that contain a PATH_RESPONSE frame to at least the smallest allowed maximum datagram size of 1200 bytes. ... However, an endpoint MUST NOT expand the datagram containing the PATH_RESPONSE if the resulting data exceeds the anti-amplification limit.
author Roman Arutyunyan <arut@nginx.com>
date Wed, 29 Nov 2023 18:13:25 +0400
parents 8852f39311de
children 791ead216b03
line wrap: on
line source


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


#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_event.h>
#include <ngx_channel.h>


static void ngx_start_worker_processes(ngx_cycle_t *cycle, ngx_int_t n,
    ngx_int_t type);
static void ngx_start_cache_manager_processes(ngx_cycle_t *cycle,
    ngx_uint_t respawn);
static void ngx_pass_open_channel(ngx_cycle_t *cycle);
static void ngx_signal_worker_processes(ngx_cycle_t *cycle, int signo);
static ngx_uint_t ngx_reap_children(ngx_cycle_t *cycle);
static void ngx_master_process_exit(ngx_cycle_t *cycle);
static void ngx_worker_process_cycle(ngx_cycle_t *cycle, void *data);
static void ngx_worker_process_init(ngx_cycle_t *cycle, ngx_int_t worker);
static void ngx_worker_process_exit(ngx_cycle_t *cycle);
static void ngx_channel_handler(ngx_event_t *ev);
static void ngx_cache_manager_process_cycle(ngx_cycle_t *cycle, void *data);
static void ngx_cache_manager_process_handler(ngx_event_t *ev);
static void ngx_cache_loader_process_handler(ngx_event_t *ev);


ngx_uint_t    ngx_process;
ngx_uint_t    ngx_worker;
ngx_pid_t     ngx_pid;
ngx_pid_t     ngx_parent;

sig_atomic_t  ngx_reap;
sig_atomic_t  ngx_sigio;
sig_atomic_t  ngx_sigalrm;
sig_atomic_t  ngx_terminate;
sig_atomic_t  ngx_quit;
sig_atomic_t  ngx_debug_quit;
ngx_uint_t    ngx_exiting;
sig_atomic_t  ngx_reconfigure;
sig_atomic_t  ngx_reopen;

sig_atomic_t  ngx_change_binary;
ngx_pid_t     ngx_new_binary;
ngx_uint_t    ngx_inherited;
ngx_uint_t    ngx_daemonized;

sig_atomic_t  ngx_noaccept;
ngx_uint_t    ngx_noaccepting;
ngx_uint_t    ngx_restart;


static u_char  master_process[] = "master process";


static ngx_cache_manager_ctx_t  ngx_cache_manager_ctx = {
    ngx_cache_manager_process_handler, "cache manager process", 0
};

static ngx_cache_manager_ctx_t  ngx_cache_loader_ctx = {
    ngx_cache_loader_process_handler, "cache loader process", 60000
};


static ngx_cycle_t      ngx_exit_cycle;
static ngx_log_t        ngx_exit_log;
static ngx_open_file_t  ngx_exit_log_file;


void
ngx_master_process_cycle(ngx_cycle_t *cycle)
{
    char              *title;
    u_char            *p;
    size_t             size;
    ngx_int_t          i;
    ngx_uint_t         sigio;
    sigset_t           set;
    struct itimerval   itv;
    ngx_uint_t         live;
    ngx_msec_t         delay;
    ngx_core_conf_t   *ccf;

    sigemptyset(&set);
    sigaddset(&set, SIGCHLD);
    sigaddset(&set, SIGALRM);
    sigaddset(&set, SIGIO);
    sigaddset(&set, SIGINT);
    sigaddset(&set, ngx_signal_value(NGX_RECONFIGURE_SIGNAL));
    sigaddset(&set, ngx_signal_value(NGX_REOPEN_SIGNAL));
    sigaddset(&set, ngx_signal_value(NGX_NOACCEPT_SIGNAL));
    sigaddset(&set, ngx_signal_value(NGX_TERMINATE_SIGNAL));
    sigaddset(&set, ngx_signal_value(NGX_SHUTDOWN_SIGNAL));
    sigaddset(&set, ngx_signal_value(NGX_CHANGEBIN_SIGNAL));

    if (sigprocmask(SIG_BLOCK, &set, NULL) == -1) {
        ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                      "sigprocmask() failed");
    }

    sigemptyset(&set);


    size = sizeof(master_process);

    for (i = 0; i < ngx_argc; i++) {
        size += ngx_strlen(ngx_argv[i]) + 1;
    }

    title = ngx_pnalloc(cycle->pool, size);
    if (title == NULL) {
        /* fatal */
        exit(2);
    }

    p = ngx_cpymem(title, master_process, sizeof(master_process) - 1);
    for (i = 0; i < ngx_argc; i++) {
        *p++ = ' ';
        p = ngx_cpystrn(p, (u_char *) ngx_argv[i], size);
    }

    ngx_setproctitle(title);


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

    ngx_start_worker_processes(cycle, ccf->worker_processes,
                               NGX_PROCESS_RESPAWN);
    ngx_start_cache_manager_processes(cycle, 0);

    ngx_new_binary = 0;
    delay = 0;
    sigio = 0;
    live = 1;

    for ( ;; ) {
        if (delay) {
            if (ngx_sigalrm) {
                sigio = 0;
                delay *= 2;
                ngx_sigalrm = 0;
            }

            ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
                           "termination cycle: %M", delay);

            itv.it_interval.tv_sec = 0;
            itv.it_interval.tv_usec = 0;
            itv.it_value.tv_sec = delay / 1000;
            itv.it_value.tv_usec = (delay % 1000 ) * 1000;

            if (setitimer(ITIMER_REAL, &itv, NULL) == -1) {
                ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                              "setitimer() failed");
            }
        }

        ngx_log_debug0(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "sigsuspend");

        sigsuspend(&set);

        ngx_time_update();

        ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
                       "wake up, sigio %i", sigio);

        if (ngx_reap) {
            ngx_reap = 0;
            ngx_log_debug0(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "reap children");

            live = ngx_reap_children(cycle);
        }

        if (!live && (ngx_terminate || ngx_quit)) {
            ngx_master_process_exit(cycle);
        }

        if (ngx_terminate) {
            if (delay == 0) {
                delay = 50;
            }

            if (sigio) {
                sigio--;
                continue;
            }

            sigio = ccf->worker_processes + 2 /* cache processes */;

            if (delay > 1000) {
                ngx_signal_worker_processes(cycle, SIGKILL);
            } else {
                ngx_signal_worker_processes(cycle,
                                       ngx_signal_value(NGX_TERMINATE_SIGNAL));
            }

            continue;
        }

        if (ngx_quit) {
            ngx_signal_worker_processes(cycle,
                                        ngx_signal_value(NGX_SHUTDOWN_SIGNAL));
            ngx_close_listening_sockets(cycle);

            continue;
        }

        if (ngx_reconfigure) {
            ngx_reconfigure = 0;

            if (ngx_new_binary) {
                ngx_start_worker_processes(cycle, ccf->worker_processes,
                                           NGX_PROCESS_RESPAWN);
                ngx_start_cache_manager_processes(cycle, 0);
                ngx_noaccepting = 0;

                continue;
            }

            ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "reconfiguring");

            cycle = ngx_init_cycle(cycle);
            if (cycle == NULL) {
                cycle = (ngx_cycle_t *) ngx_cycle;
                continue;
            }

            ngx_cycle = cycle;
            ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx,
                                                   ngx_core_module);
            ngx_start_worker_processes(cycle, ccf->worker_processes,
                                       NGX_PROCESS_JUST_RESPAWN);
            ngx_start_cache_manager_processes(cycle, 1);

            /* allow new processes to start */
            ngx_msleep(100);

            live = 1;
            ngx_signal_worker_processes(cycle,
                                        ngx_signal_value(NGX_SHUTDOWN_SIGNAL));
        }

        if (ngx_restart) {
            ngx_restart = 0;
            ngx_start_worker_processes(cycle, ccf->worker_processes,
                                       NGX_PROCESS_RESPAWN);
            ngx_start_cache_manager_processes(cycle, 0);
            live = 1;
        }

        if (ngx_reopen) {
            ngx_reopen = 0;
            ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "reopening logs");
            ngx_reopen_files(cycle, ccf->user);
            ngx_signal_worker_processes(cycle,
                                        ngx_signal_value(NGX_REOPEN_SIGNAL));
        }

        if (ngx_change_binary) {
            ngx_change_binary = 0;
            ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "changing binary");
            ngx_new_binary = ngx_exec_new_binary(cycle, ngx_argv);
        }

        if (ngx_noaccept) {
            ngx_noaccept = 0;
            ngx_noaccepting = 1;
            ngx_signal_worker_processes(cycle,
                                        ngx_signal_value(NGX_SHUTDOWN_SIGNAL));
        }
    }
}


void
ngx_single_process_cycle(ngx_cycle_t *cycle)
{
    ngx_uint_t  i;

    if (ngx_set_environment(cycle, NULL) == NULL) {
        /* fatal */
        exit(2);
    }

    for (i = 0; cycle->modules[i]; i++) {
        if (cycle->modules[i]->init_process) {
            if (cycle->modules[i]->init_process(cycle) == NGX_ERROR) {
                /* fatal */
                exit(2);
            }
        }
    }

    for ( ;; ) {
        ngx_log_debug0(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "worker cycle");

        ngx_process_events_and_timers(cycle);

        if (ngx_terminate || ngx_quit) {

            for (i = 0; cycle->modules[i]; i++) {
                if (cycle->modules[i]->exit_process) {
                    cycle->modules[i]->exit_process(cycle);
                }
            }

            ngx_master_process_exit(cycle);
        }

        if (ngx_reconfigure) {
            ngx_reconfigure = 0;
            ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "reconfiguring");

            cycle = ngx_init_cycle(cycle);
            if (cycle == NULL) {
                cycle = (ngx_cycle_t *) ngx_cycle;
                continue;
            }

            ngx_cycle = cycle;
        }

        if (ngx_reopen) {
            ngx_reopen = 0;
            ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "reopening logs");
            ngx_reopen_files(cycle, (ngx_uid_t) -1);
        }
    }
}


static void
ngx_start_worker_processes(ngx_cycle_t *cycle, ngx_int_t n, ngx_int_t type)
{
    ngx_int_t  i;

    ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "start worker processes");

    for (i = 0; i < n; i++) {

        ngx_spawn_process(cycle, ngx_worker_process_cycle,
                          (void *) (intptr_t) i, "worker process", type);

        ngx_pass_open_channel(cycle);
    }
}


static void
ngx_start_cache_manager_processes(ngx_cycle_t *cycle, ngx_uint_t respawn)
{
    ngx_uint_t    i, manager, loader;
    ngx_path_t  **path;

    manager = 0;
    loader = 0;

    path = ngx_cycle->paths.elts;
    for (i = 0; i < ngx_cycle->paths.nelts; i++) {

        if (path[i]->manager) {
            manager = 1;
        }

        if (path[i]->loader) {
            loader = 1;
        }
    }

    if (manager == 0) {
        return;
    }

    ngx_spawn_process(cycle, ngx_cache_manager_process_cycle,
                      &ngx_cache_manager_ctx, "cache manager process",
                      respawn ? NGX_PROCESS_JUST_RESPAWN : NGX_PROCESS_RESPAWN);

    ngx_pass_open_channel(cycle);

    if (loader == 0) {
        return;
    }

    ngx_spawn_process(cycle, ngx_cache_manager_process_cycle,
                      &ngx_cache_loader_ctx, "cache loader process",
                      respawn ? NGX_PROCESS_JUST_SPAWN : NGX_PROCESS_NORESPAWN);

    ngx_pass_open_channel(cycle);
}


static void
ngx_pass_open_channel(ngx_cycle_t *cycle)
{
    ngx_int_t      i;
    ngx_channel_t  ch;

    ngx_memzero(&ch, sizeof(ngx_channel_t));

    ch.command = NGX_CMD_OPEN_CHANNEL;
    ch.pid = ngx_processes[ngx_process_slot].pid;
    ch.slot = ngx_process_slot;
    ch.fd = ngx_processes[ngx_process_slot].channel[0];

    for (i = 0; i < ngx_last_process; i++) {

        if (i == ngx_process_slot
            || ngx_processes[i].pid == -1
            || ngx_processes[i].channel[0] == -1)
        {
            continue;
        }

        ngx_log_debug6(NGX_LOG_DEBUG_CORE, cycle->log, 0,
                      "pass channel s:%i pid:%P fd:%d to s:%i pid:%P fd:%d",
                      ch.slot, ch.pid, ch.fd,
                      i, ngx_processes[i].pid,
                      ngx_processes[i].channel[0]);

        /* TODO: NGX_AGAIN */

        ngx_write_channel(ngx_processes[i].channel[0],
                          &ch, sizeof(ngx_channel_t), cycle->log);
    }
}


static void
ngx_signal_worker_processes(ngx_cycle_t *cycle, int signo)
{
    ngx_int_t      i;
    ngx_err_t      err;
    ngx_channel_t  ch;

    ngx_memzero(&ch, sizeof(ngx_channel_t));

#if (NGX_BROKEN_SCM_RIGHTS)

    ch.command = 0;

#else

    switch (signo) {

    case ngx_signal_value(NGX_SHUTDOWN_SIGNAL):
        ch.command = NGX_CMD_QUIT;
        break;

    case ngx_signal_value(NGX_TERMINATE_SIGNAL):
        ch.command = NGX_CMD_TERMINATE;
        break;

    case ngx_signal_value(NGX_REOPEN_SIGNAL):
        ch.command = NGX_CMD_REOPEN;
        break;

    default:
        ch.command = 0;
    }

#endif

    ch.fd = -1;


    for (i = 0; i < ngx_last_process; i++) {

        ngx_log_debug7(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
                       "child: %i %P e:%d t:%d d:%d r:%d j:%d",
                       i,
                       ngx_processes[i].pid,
                       ngx_processes[i].exiting,
                       ngx_processes[i].exited,
                       ngx_processes[i].detached,
                       ngx_processes[i].respawn,
                       ngx_processes[i].just_spawn);

        if (ngx_processes[i].detached || ngx_processes[i].pid == -1) {
            continue;
        }

        if (ngx_processes[i].just_spawn) {
            ngx_processes[i].just_spawn = 0;
            continue;
        }

        if (ngx_processes[i].exiting
            && signo == ngx_signal_value(NGX_SHUTDOWN_SIGNAL))
        {
            continue;
        }

        if (ch.command) {
            if (ngx_write_channel(ngx_processes[i].channel[0],
                                  &ch, sizeof(ngx_channel_t), cycle->log)
                == NGX_OK)
            {
                if (signo != ngx_signal_value(NGX_REOPEN_SIGNAL)) {
                    ngx_processes[i].exiting = 1;
                }

                continue;
            }
        }

        ngx_log_debug2(NGX_LOG_DEBUG_CORE, cycle->log, 0,
                       "kill (%P, %d)", ngx_processes[i].pid, signo);

        if (kill(ngx_processes[i].pid, signo) == -1) {
            err = ngx_errno;
            ngx_log_error(NGX_LOG_ALERT, cycle->log, err,
                          "kill(%P, %d) failed", ngx_processes[i].pid, signo);

            if (err == NGX_ESRCH) {
                ngx_processes[i].exited = 1;
                ngx_processes[i].exiting = 0;
                ngx_reap = 1;
            }

            continue;
        }

        if (signo != ngx_signal_value(NGX_REOPEN_SIGNAL)) {
            ngx_processes[i].exiting = 1;
        }
    }
}


static ngx_uint_t
ngx_reap_children(ngx_cycle_t *cycle)
{
    ngx_int_t         i, n;
    ngx_uint_t        live;
    ngx_channel_t     ch;
    ngx_core_conf_t  *ccf;

    ngx_memzero(&ch, sizeof(ngx_channel_t));

    ch.command = NGX_CMD_CLOSE_CHANNEL;
    ch.fd = -1;

    live = 0;
    for (i = 0; i < ngx_last_process; i++) {

        ngx_log_debug7(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
                       "child: %i %P e:%d t:%d d:%d r:%d j:%d",
                       i,
                       ngx_processes[i].pid,
                       ngx_processes[i].exiting,
                       ngx_processes[i].exited,
                       ngx_processes[i].detached,
                       ngx_processes[i].respawn,
                       ngx_processes[i].just_spawn);

        if (ngx_processes[i].pid == -1) {
            continue;
        }

        if (ngx_processes[i].exited) {

            if (!ngx_processes[i].detached) {
                ngx_close_channel(ngx_processes[i].channel, cycle->log);

                ngx_processes[i].channel[0] = -1;
                ngx_processes[i].channel[1] = -1;

                ch.pid = ngx_processes[i].pid;
                ch.slot = i;

                for (n = 0; n < ngx_last_process; n++) {
                    if (ngx_processes[n].exited
                        || ngx_processes[n].pid == -1
                        || ngx_processes[n].channel[0] == -1)
                    {
                        continue;
                    }

                    ngx_log_debug3(NGX_LOG_DEBUG_CORE, cycle->log, 0,
                                   "pass close channel s:%i pid:%P to:%P",
                                   ch.slot, ch.pid, ngx_processes[n].pid);

                    /* TODO: NGX_AGAIN */

                    ngx_write_channel(ngx_processes[n].channel[0],
                                      &ch, sizeof(ngx_channel_t), cycle->log);
                }
            }

            if (ngx_processes[i].respawn
                && !ngx_processes[i].exiting
                && !ngx_terminate
                && !ngx_quit)
            {
                if (ngx_spawn_process(cycle, ngx_processes[i].proc,
                                      ngx_processes[i].data,
                                      ngx_processes[i].name, i)
                    == NGX_INVALID_PID)
                {
                    ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
                                  "could not respawn %s",
                                  ngx_processes[i].name);
                    continue;
                }


                ngx_pass_open_channel(cycle);

                live = 1;

                continue;
            }

            if (ngx_processes[i].pid == ngx_new_binary) {

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

                if (ngx_rename_file((char *) ccf->oldpid.data,
                                    (char *) 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 the new binary process \"%s\" exited",
                                  ccf->oldpid.data, ccf->pid.data, ngx_argv[0]);
                }

                ngx_new_binary = 0;
                if (ngx_noaccepting) {
                    ngx_restart = 1;
                    ngx_noaccepting = 0;
                }
            }

            if (i == ngx_last_process - 1) {
                ngx_last_process--;

            } else {
                ngx_processes[i].pid = -1;
            }

        } else if (ngx_processes[i].exiting || !ngx_processes[i].detached) {
            live = 1;
        }
    }

    return live;
}


static void
ngx_master_process_exit(ngx_cycle_t *cycle)
{
    ngx_uint_t  i;

    ngx_delete_pidfile(cycle);

    ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "exit");

    for (i = 0; cycle->modules[i]; i++) {
        if (cycle->modules[i]->exit_master) {
            cycle->modules[i]->exit_master(cycle);
        }
    }

    ngx_close_listening_sockets(cycle);

    /*
     * Copy ngx_cycle->log related data to the special static exit cycle,
     * log, and log file structures enough to allow a signal handler to log.
     * The handler may be called when standard ngx_cycle->log allocated from
     * ngx_cycle->pool is already destroyed.
     */


    ngx_exit_log = *ngx_log_get_file_log(ngx_cycle->log);

    ngx_exit_log_file.fd = ngx_exit_log.file->fd;
    ngx_exit_log.file = &ngx_exit_log_file;
    ngx_exit_log.next = NULL;
    ngx_exit_log.writer = NULL;

    ngx_exit_cycle.log = &ngx_exit_log;
    ngx_exit_cycle.files = ngx_cycle->files;
    ngx_exit_cycle.files_n = ngx_cycle->files_n;
    ngx_cycle = &ngx_exit_cycle;

    ngx_destroy_pool(cycle->pool);

    exit(0);
}


static void
ngx_worker_process_cycle(ngx_cycle_t *cycle, void *data)
{
    ngx_int_t worker = (intptr_t) data;

    ngx_process = NGX_PROCESS_WORKER;
    ngx_worker = worker;

    ngx_worker_process_init(cycle, worker);

    ngx_setproctitle("worker process");

    for ( ;; ) {

        if (ngx_exiting) {
            if (ngx_event_no_timers_left() == NGX_OK) {
                ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "exiting");
                ngx_worker_process_exit(cycle);
            }
        }

        ngx_log_debug0(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "worker cycle");

        ngx_process_events_and_timers(cycle);

        if (ngx_terminate) {
            ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "exiting");
            ngx_worker_process_exit(cycle);
        }

        if (ngx_quit) {
            ngx_quit = 0;
            ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0,
                          "gracefully shutting down");
            ngx_setproctitle("worker process is shutting down");

            if (!ngx_exiting) {
                ngx_exiting = 1;
                ngx_set_shutdown_timer(cycle);
                ngx_close_listening_sockets(cycle);
                ngx_close_idle_connections(cycle);
                ngx_event_process_posted(cycle, &ngx_posted_events);
            }
        }

        if (ngx_reopen) {
            ngx_reopen = 0;
            ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "reopening logs");
            ngx_reopen_files(cycle, -1);
        }
    }
}


static void
ngx_worker_process_init(ngx_cycle_t *cycle, ngx_int_t worker)
{
    sigset_t          set;
    ngx_int_t         n;
    ngx_time_t       *tp;
    ngx_uint_t        i;
    ngx_cpuset_t     *cpu_affinity;
    struct rlimit     rlmt;
    ngx_core_conf_t  *ccf;

    if (ngx_set_environment(cycle, NULL) == NULL) {
        /* fatal */
        exit(2);
    }

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

    if (worker >= 0 && ccf->priority != 0) {
        if (setpriority(PRIO_PROCESS, 0, ccf->priority) == -1) {
            ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                          "setpriority(%d) failed", ccf->priority);
        }
    }

    if (ccf->rlimit_nofile != NGX_CONF_UNSET) {
        rlmt.rlim_cur = (rlim_t) ccf->rlimit_nofile;
        rlmt.rlim_max = (rlim_t) ccf->rlimit_nofile;

        if (setrlimit(RLIMIT_NOFILE, &rlmt) == -1) {
            ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                          "setrlimit(RLIMIT_NOFILE, %i) failed",
                          ccf->rlimit_nofile);
        }
    }

    if (ccf->rlimit_core != NGX_CONF_UNSET) {
        rlmt.rlim_cur = (rlim_t) ccf->rlimit_core;
        rlmt.rlim_max = (rlim_t) ccf->rlimit_core;

        if (setrlimit(RLIMIT_CORE, &rlmt) == -1) {
            ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                          "setrlimit(RLIMIT_CORE, %O) failed",
                          ccf->rlimit_core);
        }
    }

    if (geteuid() == 0) {
        if (setgid(ccf->group) == -1) {
            ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
                          "setgid(%d) failed", ccf->group);
            /* fatal */
            exit(2);
        }

        if (initgroups(ccf->username, ccf->group) == -1) {
            ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
                          "initgroups(%s, %d) failed",
                          ccf->username, ccf->group);
        }

#if (NGX_HAVE_PR_SET_KEEPCAPS && NGX_HAVE_CAPABILITIES)
        if (ccf->transparent && ccf->user) {
            if (prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0) == -1) {
                ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
                              "prctl(PR_SET_KEEPCAPS, 1) failed");
                /* fatal */
                exit(2);
            }
        }
#endif

        if (setuid(ccf->user) == -1) {
            ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
                          "setuid(%d) failed", ccf->user);
            /* fatal */
            exit(2);
        }

#if (NGX_HAVE_CAPABILITIES)
        if (ccf->transparent && ccf->user) {
            struct __user_cap_data_struct    data;
            struct __user_cap_header_struct  header;

            ngx_memzero(&header, sizeof(struct __user_cap_header_struct));
            ngx_memzero(&data, sizeof(struct __user_cap_data_struct));

            header.version = _LINUX_CAPABILITY_VERSION_1;
            data.effective = CAP_TO_MASK(CAP_NET_RAW);
            data.permitted = data.effective;

            if (syscall(SYS_capset, &header, &data) == -1) {
                ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
                              "capset() failed");
                /* fatal */
                exit(2);
            }
        }
#endif
    }

    if (worker >= 0) {
        cpu_affinity = ngx_get_cpu_affinity(worker);

        if (cpu_affinity) {
            ngx_setaffinity(cpu_affinity, cycle->log);
        }
    }

#if (NGX_HAVE_PR_SET_DUMPABLE)

    /* allow coredump after setuid() in Linux 2.4.x */

    if (prctl(PR_SET_DUMPABLE, 1, 0, 0, 0) == -1) {
        ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                      "prctl(PR_SET_DUMPABLE) failed");
    }

#endif

    if (ccf->working_directory.len) {
        if (chdir((char *) ccf->working_directory.data) == -1) {
            ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                          "chdir(\"%s\") failed", ccf->working_directory.data);
            /* fatal */
            exit(2);
        }
    }

    sigemptyset(&set);

    if (sigprocmask(SIG_SETMASK, &set, NULL) == -1) {
        ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                      "sigprocmask() failed");
    }

    tp = ngx_timeofday();
    srandom(((unsigned) ngx_pid << 16) ^ tp->sec ^ tp->msec);

    for (i = 0; cycle->modules[i]; i++) {
        if (cycle->modules[i]->init_process) {
            if (cycle->modules[i]->init_process(cycle) == NGX_ERROR) {
                /* fatal */
                exit(2);
            }
        }
    }

    for (n = 0; n < ngx_last_process; n++) {

        if (ngx_processes[n].pid == -1) {
            continue;
        }

        if (n == ngx_process_slot) {
            continue;
        }

        if (ngx_processes[n].channel[1] == -1) {
            continue;
        }

        if (close(ngx_processes[n].channel[1]) == -1) {
            ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                          "close() channel failed");
        }
    }

    if (close(ngx_processes[ngx_process_slot].channel[0]) == -1) {
        ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                      "close() channel failed");
    }

#if 0
    ngx_last_process = 0;
#endif

    if (ngx_add_channel_event(cycle, ngx_channel, NGX_READ_EVENT,
                              ngx_channel_handler)
        == NGX_ERROR)
    {
        /* fatal */
        exit(2);
    }
}


static void
ngx_worker_process_exit(ngx_cycle_t *cycle)
{
    ngx_uint_t         i;
    ngx_connection_t  *c;

    for (i = 0; cycle->modules[i]; i++) {
        if (cycle->modules[i]->exit_process) {
            cycle->modules[i]->exit_process(cycle);
        }
    }

    if (ngx_exiting) {
        c = cycle->connections;
        for (i = 0; i < cycle->connection_n; i++) {
            if (c[i].fd != -1
                && c[i].read
                && !c[i].read->accept
                && !c[i].read->channel
                && !c[i].read->resolver)
            {
                ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
                              "*%uA open socket #%d left in connection %ui",
                              c[i].number, c[i].fd, i);
                ngx_debug_quit = 1;
            }
        }

        if (ngx_debug_quit) {
            ngx_log_error(NGX_LOG_ALERT, cycle->log, 0, "aborting");
            ngx_debug_point();
        }
    }

    /*
     * Copy ngx_cycle->log related data to the special static exit cycle,
     * log, and log file structures enough to allow a signal handler to log.
     * The handler may be called when standard ngx_cycle->log allocated from
     * ngx_cycle->pool is already destroyed.
     */

    ngx_exit_log = *ngx_log_get_file_log(ngx_cycle->log);

    ngx_exit_log_file.fd = ngx_exit_log.file->fd;
    ngx_exit_log.file = &ngx_exit_log_file;
    ngx_exit_log.next = NULL;
    ngx_exit_log.writer = NULL;

    ngx_exit_cycle.log = &ngx_exit_log;
    ngx_exit_cycle.files = ngx_cycle->files;
    ngx_exit_cycle.files_n = ngx_cycle->files_n;
    ngx_cycle = &ngx_exit_cycle;

    ngx_destroy_pool(cycle->pool);

    ngx_log_error(NGX_LOG_NOTICE, ngx_cycle->log, 0, "exit");

    exit(0);
}


static void
ngx_channel_handler(ngx_event_t *ev)
{
    ngx_int_t          n;
    ngx_channel_t      ch;
    ngx_connection_t  *c;

    if (ev->timedout) {
        ev->timedout = 0;
        return;
    }

    c = ev->data;

    ngx_log_debug0(NGX_LOG_DEBUG_CORE, ev->log, 0, "channel handler");

    for ( ;; ) {

        n = ngx_read_channel(c->fd, &ch, sizeof(ngx_channel_t), ev->log);

        ngx_log_debug1(NGX_LOG_DEBUG_CORE, ev->log, 0, "channel: %i", n);

        if (n == NGX_ERROR) {

            if (ngx_event_flags & NGX_USE_EPOLL_EVENT) {
                ngx_del_conn(c, 0);
            }

            ngx_close_connection(c);
            return;
        }

        if (ngx_event_flags & NGX_USE_EVENTPORT_EVENT) {
            if (ngx_add_event(ev, NGX_READ_EVENT, 0) == NGX_ERROR) {
                return;
            }
        }

        if (n == NGX_AGAIN) {
            return;
        }

        ngx_log_debug1(NGX_LOG_DEBUG_CORE, ev->log, 0,
                       "channel command: %ui", ch.command);

        switch (ch.command) {

        case NGX_CMD_QUIT:
            ngx_quit = 1;
            break;

        case NGX_CMD_TERMINATE:
            ngx_terminate = 1;
            break;

        case NGX_CMD_REOPEN:
            ngx_reopen = 1;
            break;

        case NGX_CMD_OPEN_CHANNEL:

            ngx_log_debug3(NGX_LOG_DEBUG_CORE, ev->log, 0,
                           "get channel s:%i pid:%P fd:%d",
                           ch.slot, ch.pid, ch.fd);

            ngx_processes[ch.slot].pid = ch.pid;
            ngx_processes[ch.slot].channel[0] = ch.fd;
            break;

        case NGX_CMD_CLOSE_CHANNEL:

            ngx_log_debug4(NGX_LOG_DEBUG_CORE, ev->log, 0,
                           "close channel s:%i pid:%P our:%P fd:%d",
                           ch.slot, ch.pid, ngx_processes[ch.slot].pid,
                           ngx_processes[ch.slot].channel[0]);

            if (close(ngx_processes[ch.slot].channel[0]) == -1) {
                ngx_log_error(NGX_LOG_ALERT, ev->log, ngx_errno,
                              "close() channel failed");
            }

            ngx_processes[ch.slot].channel[0] = -1;
            break;
        }
    }
}


static void
ngx_cache_manager_process_cycle(ngx_cycle_t *cycle, void *data)
{
    ngx_cache_manager_ctx_t *ctx = data;

    void         *ident[4];
    ngx_event_t   ev;

    /*
     * Set correct process type since closing listening Unix domain socket
     * in a master process also removes the Unix domain socket file.
     */
    ngx_process = NGX_PROCESS_HELPER;

    ngx_close_listening_sockets(cycle);

    /* Set a moderate number of connections for a helper process. */
    cycle->connection_n = 512;

    ngx_worker_process_init(cycle, -1);

    ngx_memzero(&ev, sizeof(ngx_event_t));
    ev.handler = ctx->handler;
    ev.data = ident;
    ev.log = cycle->log;
    ident[3] = (void *) -1;

    ngx_use_accept_mutex = 0;

    ngx_setproctitle(ctx->name);

    ngx_add_timer(&ev, ctx->delay);

    for ( ;; ) {

        if (ngx_terminate || ngx_quit) {
            ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "exiting");
            exit(0);
        }

        if (ngx_reopen) {
            ngx_reopen = 0;
            ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "reopening logs");
            ngx_reopen_files(cycle, -1);
        }

        ngx_process_events_and_timers(cycle);
    }
}


static void
ngx_cache_manager_process_handler(ngx_event_t *ev)
{
    ngx_uint_t    i;
    ngx_msec_t    next, n;
    ngx_path_t  **path;

    next = 60 * 60 * 1000;

    path = ngx_cycle->paths.elts;
    for (i = 0; i < ngx_cycle->paths.nelts; i++) {

        if (path[i]->manager) {
            n = path[i]->manager(path[i]->data);

            next = (n <= next) ? n : next;

            ngx_time_update();
        }
    }

    if (next == 0) {
        next = 1;
    }

    ngx_add_timer(ev, next);
}


static void
ngx_cache_loader_process_handler(ngx_event_t *ev)
{
    ngx_uint_t     i;
    ngx_path_t   **path;
    ngx_cycle_t   *cycle;

    cycle = (ngx_cycle_t *) ngx_cycle;

    path = cycle->paths.elts;
    for (i = 0; i < cycle->paths.nelts; i++) {

        if (ngx_terminate || ngx_quit) {
            break;
        }

        if (path[i]->loader) {
            path[i]->loader(path[i]->data);
            ngx_time_update();
        }
    }

    exit(0);
}