|  |  | 
|  | /* | 
|  | * 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; | 
|  |  | 
|  | if (send < limit) { | 
|  |  | 
|  | /* | 
|  | * 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; | 
|  |  | 
|  | } else { | 
|  | trailer.count = 0; | 
|  | } | 
|  |  | 
|  | if (ngx_freebsd_use_tcp_nopush | 
|  | && c->tcp_nopush == NGX_TCP_NOPUSH_UNSET) | 
|  | { | 
|  | if (ngx_tcp_nopush(c->fd) == -1) { | 
|  | 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 (aio->event.active) { | 
|  | /* | 
|  | * tolerate duplicate calls; they can happen due to subrequests | 
|  | * or multiple calls of the next body filter from a filter | 
|  | */ | 
|  |  | 
|  | if (sent) { | 
|  | c->busy_count = 0; | 
|  | } | 
|  |  | 
|  | return in; | 
|  | } | 
|  |  | 
|  | 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; | 
|  | } | 
|  | } | 
|  | } |