view src/os/unix/ngx_udp_send.c @ 8826:3436b441239b quic

HTTP/3: proper uni stream closure detection. Previously, closure detection for server-initiated uni streams was not properly implemented. Instead, HTTP/3 code relied on QUIC code posting the read event and setting rev->error when it needed to close the stream. Then, regular uni stream read handler called c->recv() and received error, which closed the stream. This was an ad-hoc solution. If, for whatever reason, the read handler was called earlier, c->recv() would return 0, which would also close the stream. Now server-initiated uni streams have a separate read event handler for tracking stream closure. The handler calls c->recv(), which normally returns 0, but may return error in case of closure.
author Roman Arutyunyan <arut@nginx.com>
date Mon, 31 Jan 2022 09:46:30 +0300
parents 8f038068f4bc
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_udp_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;

    for ( ;; ) {
        n = sendto(c->fd, buf, size, 0, c->sockaddr, c->socklen);

        ngx_log_debug4(NGX_LOG_DEBUG_EVENT, c->log, 0,
                       "sendto: fd:%d %z of %uz to \"%V\"",
                       c->fd, n, size, &c->addr_text);

        if (n >= 0) {
            if ((size_t) n != size) {
                wev->error = 1;
                (void) ngx_connection_error(c, 0, "sendto() incomplete");
                return NGX_ERROR;
            }

            c->sent += n;

            return n;
        }

        err = ngx_socket_errno;

        if (err == NGX_EAGAIN) {
            wev->ready = 0;
            ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, NGX_EAGAIN,
                           "sendto() not ready");
            return NGX_AGAIN;
        }

        if (err != NGX_EINTR) {
            wev->error = 1;
            (void) ngx_connection_error(c, err, "sendto() failed");
            return NGX_ERROR;
        }
    }
}