|  | 
 | /* | 
 |  * 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 (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; | 
 |         } | 
 |     } | 
 | } |