view src/event/ngx_event_timer.h @ 7667:1ece2ac2555a

OCSP: fixed use-after-free on error. When validating second and further certificates, ssl callback could be called twice to report the error. After the first call client connection is terminated and its memory is released. Prior to the second call and in it released connection memory is accessed. Errors triggering this behavior: - failure to create the request - failure to start resolving OCSP responder name - failure to start connecting to the OCSP responder The fix is to rearrange the code to eliminate the second call.
author Roman Arutyunyan <arut@nginx.com>
date Mon, 15 Jun 2020 20:17:16 +0300
parents 3069dd358ba2
children
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_EVENT_TIMER_H_INCLUDED_
#define _NGX_EVENT_TIMER_H_INCLUDED_


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


#define NGX_TIMER_INFINITE  (ngx_msec_t) -1

#define NGX_TIMER_LAZY_DELAY  300


ngx_int_t ngx_event_timer_init(ngx_log_t *log);
ngx_msec_t ngx_event_find_timer(void);
void ngx_event_expire_timers(void);
ngx_int_t ngx_event_no_timers_left(void);


extern ngx_rbtree_t  ngx_event_timer_rbtree;


static ngx_inline void
ngx_event_del_timer(ngx_event_t *ev)
{
    ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0,
                   "event timer del: %d: %M",
                    ngx_event_ident(ev->data), ev->timer.key);

    ngx_rbtree_delete(&ngx_event_timer_rbtree, &ev->timer);

#if (NGX_DEBUG)
    ev->timer.left = NULL;
    ev->timer.right = NULL;
    ev->timer.parent = NULL;
#endif

    ev->timer_set = 0;
}


static ngx_inline void
ngx_event_add_timer(ngx_event_t *ev, ngx_msec_t timer)
{
    ngx_msec_t      key;
    ngx_msec_int_t  diff;

    key = ngx_current_msec + timer;

    if (ev->timer_set) {

        /*
         * Use a previous timer value if difference between it and a new
         * value is less than NGX_TIMER_LAZY_DELAY milliseconds: this allows
         * to minimize the rbtree operations for fast connections.
         */

        diff = (ngx_msec_int_t) (key - ev->timer.key);

        if (ngx_abs(diff) < NGX_TIMER_LAZY_DELAY) {
            ngx_log_debug3(NGX_LOG_DEBUG_EVENT, ev->log, 0,
                           "event timer: %d, old: %M, new: %M",
                            ngx_event_ident(ev->data), ev->timer.key, key);
            return;
        }

        ngx_del_timer(ev);
    }

    ev->timer.key = key;

    ngx_log_debug3(NGX_LOG_DEBUG_EVENT, ev->log, 0,
                   "event timer add: %d: %M:%M",
                    ngx_event_ident(ev->data), timer, ev->timer.key);

    ngx_rbtree_insert(&ngx_event_timer_rbtree, &ev->timer);

    ev->timer_set = 1;
}


#endif /* _NGX_EVENT_TIMER_H_INCLUDED_ */