view src/event/ngx_event_posted.c @ 4162:fb1375e8b68c stable-1.0

Merging r4036, r4055, r4056, r4057, r4058, r4059, r4060, r4061, r4062, r4063, r4064: Ranges related fixes: The "max_ranges" directive. "max_ranges 0" disables ranges support at all, "max_ranges 1" allows the single range, etc. By default number of ranges is unlimited, to be precise, 2^31-1. If client requests more ranges than "max_ranges" permits, nginx disables ranges and returns just the source response. If total size of all ranges is greater than source response size, then nginx disables ranges and returns just the source response. This fix should not affect well-behaving applications but will defeat DoS attempts exploiting malicious byte ranges. Now unsatisfiable ranges are processed according to RFC 2616.
author Igor Sysoev <igor@sysoev.ru>
date Fri, 30 Sep 2011 14:06:08 +0000
parents 9c2f3ed7a247
children d620f497c50f
line wrap: on
line source


/*
 * Copyright (C) Igor Sysoev
 */


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


ngx_thread_volatile ngx_event_t  *ngx_posted_accept_events;
ngx_thread_volatile ngx_event_t  *ngx_posted_events;

#if (NGX_THREADS)
ngx_mutex_t                      *ngx_posted_events_mutex;
#endif


void
ngx_event_process_posted(ngx_cycle_t *cycle,
    ngx_thread_volatile ngx_event_t **posted)
{
    ngx_event_t  *ev;

    for ( ;; ) {

        ev = (ngx_event_t *) *posted;

        ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
                      "posted event %p", ev);

        if (ev == NULL) {
            return;
        }

        ngx_delete_posted_event(ev);

        ev->handler(ev);
    }
}


#if (NGX_THREADS) && !(NGX_WIN32)

void
ngx_wakeup_worker_thread(ngx_cycle_t *cycle)
{
    ngx_int_t     i;
#if 0
    ngx_uint_t    busy;
    ngx_event_t  *ev;

    busy = 1;

    if (ngx_mutex_lock(ngx_posted_events_mutex) == NGX_ERROR) {
        return;
    }

    for (ev = (ngx_event_t *) ngx_posted_events; ev; ev = ev->next) {
        if (*(ev->lock) == 0) {
            busy = 0;
            break;
        }
    }

    ngx_mutex_unlock(ngx_posted_events_mutex);

    if (busy) {
        return;
    }
#endif

    for (i = 0; i < ngx_threads_n; i++) {
        if (ngx_threads[i].state == NGX_THREAD_FREE) {
            ngx_cond_signal(ngx_threads[i].cv);
            return;
        }
    }
}


ngx_int_t
ngx_event_thread_process_posted(ngx_cycle_t *cycle)
{
    ngx_event_t  *ev;

    for ( ;; ) {

        ev = (ngx_event_t *) ngx_posted_events;

        for ( ;; ) {

            ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
                          "posted event %p", ev);

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

            if (ngx_trylock(ev->lock) == 0) {

                ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
                               "posted event %p is busy", ev);

                ev = ev->next;
                continue;
            }

            if (ev->lock != ev->own_lock) {
                if (*(ev->own_lock)) {
                    ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
                             "the own lock of the posted event %p is busy", ev);
                    ngx_unlock(ev->lock);
                    ev = ev->next;
                    continue;
                }
                *(ev->own_lock) = 1;
            }

            ngx_delete_posted_event(ev);

            ev->locked = 1;

            ev->ready |= ev->posted_ready;
            ev->timedout |= ev->posted_timedout;
            ev->pending_eof |= ev->posted_eof;
#if (NGX_HAVE_KQUEUE)
            ev->kq_errno |= ev->posted_errno;
#endif
            if (ev->posted_available) {
                ev->available = ev->posted_available;
            }

            ev->posted_ready = 0;
            ev->posted_timedout = 0;
            ev->posted_eof = 0;
#if (NGX_HAVE_KQUEUE)
            ev->posted_errno = 0;
#endif
            ev->posted_available = 0;

            ngx_mutex_unlock(ngx_posted_events_mutex);

            ev->handler(ev);

            ngx_mutex_lock(ngx_posted_events_mutex);

            if (ev->locked) {
                ngx_unlock(ev->lock);

                if (ev->lock != ev->own_lock) {
                    ngx_unlock(ev->own_lock);
                }
            }

            ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
                           "posted event %p is done", ev);

            break;
        }
    }
}

#else

void
ngx_wakeup_worker_thread(ngx_cycle_t *cycle)
{
}

#endif