From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EB50DC433E0 for ; Fri, 22 Jan 2021 19:40:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AE5B923B01 for ; Fri, 22 Jan 2021 19:40:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728890AbhAVThj (ORCPT ); Fri, 22 Jan 2021 14:37:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51542 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730189AbhAVSsf (ORCPT ); Fri, 22 Jan 2021 13:48:35 -0500 Received: from fieldses.org (fieldses.org [IPv6:2600:3c00:e000:2f7::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 71E2EC061786 for ; Fri, 22 Jan 2021 10:47:55 -0800 (PST) Received: by fieldses.org (Postfix, from userid 2815) id 160576E97; Fri, 22 Jan 2021 13:47:54 -0500 (EST) DKIM-Filter: OpenDKIM Filter v2.11.0 fieldses.org 160576E97 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fieldses.org; s=default; t=1611341274; bh=6qYDmKUQQN9uy1WwJye0hryd/s38VuaiUyV+IeNFclY=; h=Date:To:Cc:Subject:References:In-Reply-To:From:From; b=YtPfjUfIRfSiH/LTonIkLI+NoG0GA8pFUaJTZxC1sSU1XUEKfAdVPKPMfOXc0omCF gf8L9qfGC0QOMJfQDoJoK204+JSvJ9u9m/plees479TxLBzxwJDLOp9ezAmfa150zD KMWZ53e2Ym4IEj5a1le5/wY4/4ZRNfx823beJtKA= Date: Fri, 22 Jan 2021 13:47:54 -0500 To: Chuck Lever Cc: linux-nfs@vger.kernel.org Subject: Re: [PATCH v1 07/42] NFSD: Update WRITE3arg decoder to use struct xdr_stream Message-ID: <20210122184754.GC18583@fieldses.org> References: <160986050640.5532.16498408936966394862.stgit@klimt.1015granger.net> <160986061812.5532.3122782251888690881.stgit@klimt.1015granger.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <160986061812.5532.3122782251888690881.stgit@klimt.1015granger.net> User-Agent: Mutt/1.5.21 (2010-09-15) From: bfields@fieldses.org (J. Bruce Fields) Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org On Tue, Jan 05, 2021 at 10:30:18AM -0500, Chuck Lever wrote: > As part of the update, open code that sanity-checks the size of the > data payload against the length of the RPC Call message has to be > re-implemented to use xdr_stream infrastructure. I'm having a little trouble parsing that. Did you mean "write code"? --b. > > Signed-off-by: Chuck Lever > --- > fs/nfsd/nfs3xdr.c | 51 ++++++++++++++++++++------------------------------- > 1 file changed, 20 insertions(+), 31 deletions(-) > > diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c > index ff98eae5db81..0aafb096de91 100644 > --- a/fs/nfsd/nfs3xdr.c > +++ b/fs/nfsd/nfs3xdr.c > @@ -405,52 +405,41 @@ nfs3svc_decode_readargs(struct svc_rqst *rqstp, __be32 *p) > int > nfs3svc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p) > { > + struct xdr_stream *xdr = &rqstp->rq_arg_stream; > struct nfsd3_writeargs *args = rqstp->rq_argp; > - unsigned int len, hdr, dlen; > u32 max_blocksize = svc_max_payload(rqstp); > struct kvec *head = rqstp->rq_arg.head; > struct kvec *tail = rqstp->rq_arg.tail; > + size_t remaining; > > - p = decode_fh(p, &args->fh); > - if (!p) > + if (!svcxdr_decode_nfs_fh3(xdr, &args->fh)) > return 0; > - p = xdr_decode_hyper(p, &args->offset); > - > - args->count = ntohl(*p++); > - args->stable = ntohl(*p++); > - len = args->len = ntohl(*p++); > - if ((void *)p > head->iov_base + head->iov_len) > + if (xdr_stream_decode_u64(xdr, &args->offset) < 0) > return 0; > - /* > - * The count must equal the amount of data passed. > - */ > - if (args->count != args->len) > + if (xdr_stream_decode_u32(xdr, &args->count) < 0) > + return 0; > + if (xdr_stream_decode_u32(xdr, &args->stable) < 0) > return 0; > > - /* > - * Check to make sure that we got the right number of > - * bytes. > - */ > - hdr = (void*)p - head->iov_base; > - dlen = head->iov_len + rqstp->rq_arg.page_len + tail->iov_len - hdr; > - /* > - * Round the length of the data which was specified up to > - * the next multiple of XDR units and then compare that > - * against the length which was actually received. > - * Note that when RPCSEC/GSS (for example) is used, the > - * data buffer can be padded so dlen might be larger > - * than required. It must never be smaller. > - */ > - if (dlen < XDR_QUADLEN(len)*4) > + /* opaque data */ > + if (xdr_stream_decode_u32(xdr, &args->len) < 0) > return 0; > > + /* request sanity */ > + if (args->count != args->len) > + return 0; > + remaining = head->iov_len + rqstp->rq_arg.page_len + tail->iov_len; > + remaining -= xdr_stream_pos(xdr); > + if (remaining < xdr_align_size(args->len)) > + return 0; > if (args->count > max_blocksize) { > args->count = max_blocksize; > - len = args->len = max_blocksize; > + args->len = max_blocksize; > } > > - args->first.iov_base = (void *)p; > - args->first.iov_len = head->iov_len - hdr; > + args->first.iov_base = xdr->p; > + args->first.iov_len = head->iov_len - xdr_stream_pos(xdr); > + > return 1; > } > >