From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from fieldses.org ([174.143.236.118]:56770 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753247Ab1GLLJw (ORCPT ); Tue, 12 Jul 2011 07:09:52 -0400 Date: Tue, 12 Jul 2011 07:09:50 -0400 From: "J. Bruce Fields" To: Mi Jinlong Cc: NFS Subject: Re: [PATCH 1/2 v3] nfsd41: error out when client sets maxreq_sz or, maxresp_sz too small Message-ID: <20110712110950.GC2162@fieldses.org> References: <4E0EDE78.1060208@cn.fujitsu.com> <20110706162650.GB30349@fieldses.org> <4E17CE8C.8000504@cn.fujitsu.com> Content-Type: text/plain; charset=us-ascii In-Reply-To: <4E17CE8C.8000504@cn.fujitsu.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 On Sat, Jul 09, 2011 at 11:44:12AM +0800, Mi Jinlong wrote: > According to RFC5661, 18.36.3, > > "if the client selects a value for ca_maxresponsesize such that > a replier on a channel could never send a response,the server > SHOULD return NFS4ERR_TOOSMALL in the CREATE_SESSION reply." > > This patch let server error out when client sets maxreq_sz less than > SEQUENCE request size, and maxresp_sz less than a SEQUENCE reply size. > > v3: > use constant for min request size and min response size, > add two function for channel attrs checking(back channel checking > not be implement), > move size check from xdr create_session to nfsd4_create_session, > > Signed-off-by: Mi Jinlong > --- > fs/nfsd/nfs4state.c | 33 +++++++++++++++++++++++++++++++++ > 1 files changed, 33 insertions(+), 0 deletions(-) > > diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c > index e98f3c2..e30bf37 100644 > --- a/fs/nfsd/nfs4state.c > +++ b/fs/nfsd/nfs4state.c > @@ -1507,6 +1507,34 @@ nfsd4_replay_create_session(struct nfsd4_create_session *cr_ses, > return slot->sl_status; > } > > +#define NFSD_MIN_REQ_HDR_SEQ_SZ ((\ > + 2 * 2 + /* credential,verifier: AUTH_NULL, length 0 */ \ > + 1 + /* MIN tag is length with zero, only length */ \ > + 3 + /* version, opcount, opcode */ \ > + XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN) + \ > + /* seqid, slotID, slotID, cache */ \ > + 4 ) * sizeof(__be32)) > + > +#define NFSD_MIN_RESP_HDR_SEQ_SZ ((\ > + 2 + /* verifier: AUTH_NULL, length 0 */\ > + 1 + /* status */ \ > + 1 + /* MIN tag is length with zero, only length */ \ > + 3 + /* opcount, opcode, opstatus*/ \ > + XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN) + \ > + /* seqid, slotID, slotID, slotID, status */ \ > + 5 ) * sizeof(__be32)) > + > +static __be32 check_forechannel_attrs(struct nfsd4_channel_attrs fchannel) > +{ > + return fchannel.maxreq_sz < NFSD_MIN_REQ_HDR_SEQ_SZ > + || fchannel.maxresp_sz < NFSD_MIN_RESP_HDR_SEQ_SZ; > +} > + > +static __be32 check_backchannel_attrs(struct nfsd4_channel_attrs bchannel) > +{ > + return 0; > +} Let's not bother with check_backchannel_attrs() until it actually does something. Other than that, this looks fine.--b. > + > __be32 > nfsd4_create_session(struct svc_rqst *rqstp, > struct nfsd4_compound_state *cstate, > @@ -1575,6 +1603,11 @@ nfsd4_create_session(struct svc_rqst *rqstp, > cr_ses->flags &= ~SESSION4_PERSIST; > cr_ses->flags &= ~SESSION4_RDMA; > > + status = nfserr_toosmall; > + if (check_forechannel_attrs(cr_ses->fore_channel) > + || check_backchannel_attrs(cr_ses->back_channel)) > + goto out; > + > status = nfserr_jukebox; > new = alloc_init_session(rqstp, conf, cr_ses); > if (!new) > -- > 1.7.5.4 > >