From c2d715a1af75443631b05a49edbd152aef7e8b93 Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" Date: Mon, 27 Apr 2020 17:59:01 -0400 Subject: nfsd: handle repeated BIND_CONN_TO_SESSION If the client attempts BIND_CONN_TO_SESSION on an already bound connection, it should be either a no-op or an error. Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4state.c | 54 +++++++++++++++++++++++++++++++++++++++++------------ 1 file changed, 42 insertions(+), 12 deletions(-) (limited to 'fs/nfsd/nfs4state.c') diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 2c8567b32990..fe88f5f23cf4 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -3485,6 +3485,45 @@ __be32 nfsd4_backchannel_ctl(struct svc_rqst *rqstp, return nfs_ok; } +static struct nfsd4_conn *__nfsd4_find_conn(struct svc_xprt *xpt, struct nfsd4_session *s) +{ + struct nfsd4_conn *c; + + list_for_each_entry(c, &s->se_conns, cn_persession) { + if (c->cn_xprt == xpt) { + return c; + } + } + return NULL; +} + +static __be32 nfsd4_match_existing_connection(struct svc_rqst *rqst, + struct nfsd4_session *session, u32 req) +{ + struct nfs4_client *clp = session->se_client; + struct svc_xprt *xpt = rqst->rq_xprt; + struct nfsd4_conn *c; + __be32 status; + + /* Following the last paragraph of RFC 5661 Section 18.34.3: */ + spin_lock(&clp->cl_lock); + c = __nfsd4_find_conn(xpt, session); + if (!c) + status = nfserr_noent; + else if (req == c->cn_flags) + status = nfs_ok; + else if (req == NFS4_CDFC4_FORE_OR_BOTH && + c->cn_flags != NFS4_CDFC4_BACK) + status = nfs_ok; + else if (req == NFS4_CDFC4_BACK_OR_BOTH && + c->cn_flags != NFS4_CDFC4_FORE) + status = nfs_ok; + else + status = nfserr_inval; + spin_unlock(&clp->cl_lock); + return status; +} + __be32 nfsd4_bind_conn_to_session(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, union nfsd4_op_u *u) @@ -3506,6 +3545,9 @@ __be32 nfsd4_bind_conn_to_session(struct svc_rqst *rqstp, status = nfserr_wrong_cred; if (!nfsd4_mach_creds_match(session->se_client, rqstp)) goto out; + status = nfsd4_match_existing_connection(rqstp, session, bcts->dir); + if (status == nfs_ok || status == nfserr_inval) + goto out; status = nfsd4_map_bcts_dir(&bcts->dir); if (status) goto out; @@ -3571,18 +3613,6 @@ out: return status; } -static struct nfsd4_conn *__nfsd4_find_conn(struct svc_xprt *xpt, struct nfsd4_session *s) -{ - struct nfsd4_conn *c; - - list_for_each_entry(c, &s->se_conns, cn_persession) { - if (c->cn_xprt == xpt) { - return c; - } - } - return NULL; -} - static __be32 nfsd4_sequence_check_conn(struct nfsd4_conn *new, struct nfsd4_session *ses) { struct nfs4_client *clp = ses->se_client; -- cgit v1.2.3