Commit 47ee5298 authored by J. Bruce Fields's avatar J. Bruce Fields
Browse files

nfsd4: adjust buflen to session channel limit 



We can simplify session limit enforcement by restricting the xdr buflen
to the session size.

Also fix a preexisting bug: we should really have been taking into
account the auth-required space when comparing against session limits,
which are limits on the size of the entire rpc reply, including any krb5
overhead.

Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
parent db3f58a9

fs/nfsd/nfs4state.c

+11 −0
Original line number Diff line number Diff line
@@ -2208,11 +2208,13 @@ nfsd4_sequence(struct svc_rqst *rqstp, 
	       struct nfsd4_sequence *seq)

{

	struct nfsd4_compoundres *resp = rqstp->rq_resp;

	struct xdr_stream *xdr = &resp->xdr;

	struct nfsd4_session *session;

	struct nfs4_client *clp;

	struct nfsd4_slot *slot;

	struct nfsd4_conn *conn;

	__be32 status;

	int buflen;

	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);



	if (resp->opcnt != 1)
@@ -2281,6 +2283,15 @@ nfsd4_sequence(struct svc_rqst *rqstp, 
	if (status)

		goto out_put_session;



	buflen = (seq->cachethis) ?

			session->se_fchannel.maxresp_cached :

			session->se_fchannel.maxresp_sz;

	status = (seq->cachethis) ? nfserr_rep_too_big_to_cache :

				    nfserr_rep_too_big;

	if (xdr_restrict_buflen(xdr, buflen - 2 * RPC_MAX_AUTH_SIZE))

		goto out_put_session;



	status = nfs_ok;

	/* Success! bump slot seqid */

	slot->sl_seqid = seq->seqid;

	slot->sl_flags |= NFSD4_SLOT_INUSE;

fs/nfsd/nfs4xdr.c

+8 −16
Original line number Diff line number Diff line
@@ -3767,25 +3767,17 @@ static nfsd4_enc nfsd4_enc_ops[] = { 
__be32 nfsd4_check_resp_size(struct nfsd4_compoundres *resp, u32 respsize)

{

	struct xdr_buf *buf = &resp->rqstp->rq_res;

	struct nfsd4_session *session = resp->cstate.session;



	if (nfsd4_has_session(&resp->cstate)) {

	struct nfsd4_slot *slot = resp->cstate.slot;



		if (buf->len + respsize > session->se_fchannel.maxresp_sz)

			return nfserr_rep_too_big;



		if ((slot->sl_flags & NFSD4_SLOT_CACHETHIS) &&

		    buf->len + respsize > session->se_fchannel.maxresp_cached)

			return nfserr_rep_too_big_to_cache;

	}



	if (buf->len + respsize > buf->buflen) {

		WARN_ON_ONCE(nfsd4_has_session(&resp->cstate));

	if (buf->len + respsize <= buf->buflen)

		return nfs_ok;

	if (!nfsd4_has_session(&resp->cstate))

		return nfserr_resource;

	if (slot->sl_flags & NFSD4_SLOT_CACHETHIS) {

		WARN_ON_ONCE(1);

		return nfserr_rep_too_big_to_cache;

	}



	return 0;

	return nfserr_rep_too_big;

}



void