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: J. Bruce Fields <bfields@redhat.com>
This commit is contained in:
J. Bruce Fields 2014-03-12 21:39:35 -04:00
parent db3f58a95b
commit 47ee529864
2 changed files with 19 additions and 16 deletions

View File

@ -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;

View File

@ -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)
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;
}
if (buf->len + respsize > buf->buflen) {
WARN_ON_ONCE(nfsd4_has_session(&resp->cstate));
return nfserr_resource;
}
return 0;
return nfserr_rep_too_big;
}
void