Return-Path: Received: from cn.fujitsu.com ([222.73.24.84]:63076 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1753213Ab1GNGsL (ORCPT ); Thu, 14 Jul 2011 02:48:11 -0400 Message-ID: <4E1E91A9.1@cn.fujitsu.com> Date: Thu, 14 Jul 2011 14:50:17 +0800 From: Mi Jinlong To: "J. Bruce Fields" CC: NFS Subject: [PATCH 1/2 v4] nfsd41: error out when client sets maxreq_sz or, maxresp_sz too small References: <4E0EDE78.1060208@cn.fujitsu.com> <20110706162650.GB30349@fieldses.org> <4E17CE8C.8000504@cn.fujitsu.com> <20110712110950.GC2162@fieldses.org> In-Reply-To: <20110712110950.GC2162@fieldses.org> Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 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. v4: Bruce said "Let's not bother with check_backchannel_attrs() until it actually does something.". So delete the function, only check fore channel attr. 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 | 27 +++++++++++++++++++++++++++ 1 files changed, 27 insertions(+), 0 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index e98f3c2..72899ec 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -1507,6 +1507,29 @@ 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; +} + __be32 nfsd4_create_session(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, @@ -1575,6 +1598,10 @@ 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)) + goto out; + status = nfserr_jukebox; new = alloc_init_session(rqstp, conf, cr_ses); if (!new) -- 1.7.5.4