From 1b74c25bc1a142ee8dd7ad080e2a974f28d1cb18 Mon Sep 17 00:00:00 2001 From: Mi Jinlong Date: Thu, 14 Jul 2011 14:50:17 +0800 Subject: [PATCH] nfsd41: error out when client sets maxreq_sz or maxresp_sz too small 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." So, error out when the client sets a maxreq_sz less than the minimum possible SEQUENCE request size, or sets a maxresp_sz less than the minimum possible SEQUENCE reply size. Signed-off-by: Mi Jinlong Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4state.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index e252aa79c94f..fe4ba68886d8 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -1506,6 +1506,29 @@ 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, @@ -1574,6 +1597,10 @@ 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) -- 2.39.5