/*
* Copyright (C) Igor Sysoev
* Copyright (C) Nginx, Inc.
*/
#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_event.h>
/*
* Although FreeBSD sendfile() allows to pass a header and a trailer,
* it cannot send a header with a part of the file in one packet until
* FreeBSD 5.3. Besides, over the fast ethernet connection sendfile()
* may send the partially filled packets, i.e. the 8 file pages may be sent
* as the 11 full 1460-bytes packets, then one incomplete 324-bytes packet,
* and then again the 11 full 1460-bytes packets.
*
* Therefore we use the TCP_NOPUSH option (similar to Linux's TCP_CORK)
* to postpone the sending - it not only sends a header and the first part of
* the file in one packet, but also sends the file pages in the full packets.
*
* But until FreeBSD 4.5 turning TCP_NOPUSH off does not flush a pending
* data that less than MSS, so that data may be sent with 5 second delay.
* So we do not use TCP_NOPUSH on FreeBSD prior to 4.5, although it can be used
* for non-keepalive HTTP connections.
*/
ngx_chain_t *
ngx_freebsd_sendfile_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit)
{
int rc, flags;
off_t send, prev_send, sent;
size_t file_size;
ssize_t n;
ngx_uint_t eintr, eagain;
ngx_err_t err;
ngx_buf_t *file;
ngx_event_t *wev;
ngx_chain_t *cl;
ngx_iovec_t header, trailer;
struct sf_hdtr hdtr;
struct iovec headers[NGX_IOVS_PREALLOCATE];
struct iovec trailers[NGX_IOVS_PREALLOCATE];
#if (NGX_HAVE_AIO_SENDFILE)
ngx_uint_t ebusy;
ngx_event_aio_t *aio;
#endif
wev = c->write;
if (!wev->ready) {
return in;
}
#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_CHAIN_ERROR;
}
#endif
/* the maximum limit size is the maximum size_t value - the page size */
if (limit == 0 || limit > (off_t) (NGX_MAX_SIZE_T_VALUE - ngx_pagesize)) {
limit = NGX_MAX_SIZE_T_VALUE - ngx_pagesize;
}
send = 0;
eagain = 0;
flags = 0;
#if (NGX_HAVE_AIO_SENDFILE && NGX_SUPPRESS_WARN)
aio = NULL;
file = NULL;
#endif
header.iovs = headers;
header.nalloc = NGX_IOVS_PREALLOCATE;
trailer.iovs = trailers;
trailer.nalloc = NGX_IOVS_PREALLOCATE;
for ( ;; ) {
eintr = 0;
#if (NGX_HAVE_AIO_SENDFILE)
ebusy = 0;
#endif
prev_send = send;
/* create the header iovec and coalesce the neighbouring bufs */
cl = ngx_output_chain_to_iovec(&header, in, limit - send, c->log);
if (cl == NGX_CHAIN_ERROR) {
return NGX_CHAIN_ERROR;
}
send += header.size;
if (cl && cl->buf->in_file && send < limit) {
file = cl->buf;
/* coalesce the neighbouring file bufs */
file_size = (size_t) ngx_chain_coalesce_file(&cl, limit - send);
send += file_size;
/* create the trailer iovec and coalesce the neighbouring bufs */
cl = ngx_output_chain_to_iovec(&trailer, cl, limit - send, c->log);
if (cl == NGX_CHAIN_ERROR) {
return NGX_CHAIN_ERROR;
}
send += trailer.size;
if (ngx_freebsd_use_tcp_nopush
&& c->tcp_nopush == NGX_TCP_NOPUSH_UNSET)
{
if (ngx_tcp_nopush(c->fd) == NGX_ERROR) {
err = ngx_socket_errno;
/*
* there is a tiny chance to be interrupted, however,
* we continue a processing without the TCP_NOPUSH
*/
if (err != NGX_EINTR) {
wev->error = 1;
(void) ngx_connection_error(c, err,
ngx_tcp_nopush_n " failed");
return NGX_CHAIN_ERROR;
}
} else {
c->tcp_nopush = NGX_TCP_NOPUSH_SET;
ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, 0,
"tcp_nopush");
}
}
/*
* sendfile() does unneeded work if sf_hdtr's count is 0,
* but corresponding pointer is not NULL
*/
hdtr.headers = header.count ? header.iovs : NULL;
hdtr.hdr_cnt = header.count;
hdtr.trailers = trailer.count ? trailer.iovs : NULL;
hdtr.trl_cnt = trailer.count;
/*
* the "nbytes bug" of the old sendfile() syscall:
* http://bugs.freebsd.org/33771
*/
if (!ngx_freebsd_sendfile_nbytes_bug) {
header.size = 0;
}
sent = 0;
#if (NGX_HAVE_AIO_SENDFILE)
aio = file->file->aio;
flags = (aio && aio->preload_handler) ? SF_NODISKIO : 0;
#endif
rc = sendfile(file->file->fd, c->fd, file->file_pos,
file_size + header.size, &hdtr, &sent, flags);
if (rc == -1) {
err = ngx_errno;
switch (err) {
case NGX_EAGAIN:
eagain = 1;
break;
case NGX_EINTR:
eintr = 1;
break;
#if (NGX_HAVE_AIO_SENDFILE)
case NGX_EBUSY:
ebusy = 1;
break;
#endif
default:
wev->error = 1;
(void) ngx_connection_error(c, err, "sendfile() failed");
return NGX_CHAIN_ERROR;
}
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, err,
"sendfile() sent only %O bytes", sent);
/*
* sendfile() in FreeBSD 3.x-4.x may return value >= 0
* on success, although only 0 is documented
*/
} else if (rc >= 0 && sent == 0) {
/*
* if rc is OK and sent equal to zero, then someone
* has truncated the file, so the offset became beyond
* the end of the file
*/
ngx_log_error(NGX_LOG_ALERT, c->log, 0,
"sendfile() reported that \"%s\" was truncated at %O",
file->file->name.data, file->file_pos);
return NGX_CHAIN_ERROR;
}
ngx_log_debug4(NGX_LOG_DEBUG_EVENT, c->log, 0,
"sendfile: %d, @%O %O:%uz",
rc, file->file_pos, sent, file_size + header.size);
} else {
n = ngx_writev(c, &header);
if (n == NGX_ERROR) {
return NGX_CHAIN_ERROR;
}
sent = (n == NGX_AGAIN) ? 0 : n;
}
c->sent += sent;
in = ngx_chain_update_sent(in, sent);
#if (NGX_HAVE_AIO_SENDFILE)
if (ebusy) {
if (sent == 0) {
c->busy_count++;
if (c->busy_count > 2) {
ngx_log_error(NGX_LOG_ALERT, c->log, 0,
"sendfile(%V) returned busy again",
&file->file->name);
c->busy_count = 0;
aio->preload_handler = NULL;
send = prev_send;
continue;
}
} else {
c->busy_count = 0;
}
n = aio->preload_handler(file);
if (n > 0) {
send = prev_send + sent;
continue;
}
return in;
}
if (flags == SF_NODISKIO) {
c->busy_count = 0;
}
#endif
if (eagain) {
/*
* sendfile() may return EAGAIN, even if it has sent a whole file
* part, it indicates that the successive sendfile() call would
* return EAGAIN right away and would not send anything.
* We use it as a hint.
*/
wev->ready = 0;
return in;
}
if (eintr) {
send = prev_send + sent;
continue;
}
if (send - prev_send != sent) {
wev->ready = 0;
return in;
}
if (send >= limit || in == NULL) {
return in;
}
}
}