Mercurial > hg > nginx-quic
view src/os/unix/ngx_freebsd_sendfile_chain.c @ 8531:41f4bd4c51f1
Disabled control characters and space in header names.
Control characters (0x00-0x1f, 0x7f), space, and colon were never allowed in
header names. The only somewhat valid use is header continuation which nginx
never supported and which is explicitly obsolete by RFC 7230.
Previously, such headers were considered invalid and were ignored by default
(as per ignore_invalid_headers directive). With this change, such headers
are unconditionally rejected.
It is expected to make nginx more resilient to various attacks, in particular,
with ignore_invalid_headers switched off (which is inherently unsecure, though
nevertheless sometimes used in the wild).
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Mon, 28 Jun 2021 18:01:18 +0300 |
parents | 400a3412b1e3 |
children | 555533169506 |
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/* * 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; } } }