view src/os/unix/ngx_send.c @ 8551:c35b255d80dc quic

HTTP/3: close connection on keepalive_requests * 2. After receiving GOAWAY, client is not supposed to create new streams. However, until client reads this frame, we allow it to create new streams, which are gracefully rejected. To prevent client from abusing this algorithm, a new limit is introduced. Upon reaching keepalive_requests * 2, server now closes the entire QUIC connection claiming excessive load.
author Roman Arutyunyan <arut@nginx.com>
date Thu, 29 Jul 2021 16:01:37 +0300
parents f01ab2dbcfdc
children
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


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


ssize_t
ngx_unix_send(ngx_connection_t *c, u_char *buf, size_t size)
{
    ssize_t       n;
    ngx_err_t     err;
    ngx_event_t  *wev;

    wev = c->write;

#if (NGX_HAVE_KQUEUE)

    if ((ngx_event_flags & NGX_USE_KQUEUE_EVENT) && wev->pending_eof) {
        (void) ngx_connection_error(c, wev->kq_errno,
                               "kevent() reported about an closed connection");
        wev->error = 1;
        return NGX_ERROR;
    }

#endif

    for ( ;; ) {
        n = send(c->fd, buf, size, 0);

        ngx_log_debug3(NGX_LOG_DEBUG_EVENT, c->log, 0,
                       "send: fd:%d %z of %uz", c->fd, n, size);

        if (n > 0) {
            if (n < (ssize_t) size) {
                wev->ready = 0;
            }

            c->sent += n;

            return n;
        }

        err = ngx_socket_errno;

        if (n == 0) {
            ngx_log_error(NGX_LOG_ALERT, c->log, err, "send() returned zero");
            wev->ready = 0;
            return n;
        }

        if (err == NGX_EAGAIN || err == NGX_EINTR) {
            wev->ready = 0;

            ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err,
                           "send() not ready");

            if (err == NGX_EAGAIN) {
                return NGX_AGAIN;
            }

        } else {
            wev->error = 1;
            (void) ngx_connection_error(c, err, "send() failed");
            return NGX_ERROR;
        }
    }
}