nfsd41: enforce NFS4ERR_SEQUENCE_POS operation order rules for minorversion != 0...

Signed-off-by: Andy Adamson<andros@netapp.com>
[nfsd41: do not verify nfserr_sequence_pos for minorversion 0]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index f7be7fa..ec51936 100644 (file)
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -811,14 +811,15 @@ static inline void nfsd4_increment_op_stats(u32 opnum)
 
 typedef __be32(*nfsd4op_func)(struct svc_rqst *, struct nfsd4_compound_state *,
                              void *);
+enum nfsd4_op_flags {
+       ALLOWED_WITHOUT_FH = 1 << 0,    /* No current filehandle required */
+       ALLOWED_ON_ABSENT_FS = 2 << 0,  /* ops processed on absent fs */
+       ALLOWED_AS_FIRST_OP = 3 << 0,   /* ops reqired first in compound */
+};
 
 struct nfsd4_operation {
        nfsd4op_func op_func;
        u32 op_flags;
-/* Most ops require a valid current filehandle; a few don't: */
-#define ALLOWED_WITHOUT_FH 1
-/* GETATTR and ops not listed as returning NFS4ERR_MOVED: */
-#define ALLOWED_ON_ABSENT_FS 2
        char *op_name;
 };
 
@@ -826,6 +827,23 @@ static struct nfsd4_operation nfsd4_ops[];
 
 static const char *nfsd4_op_name(unsigned opnum);
 
+/*
+ * Enforce NFSv4.1 COMPOUND ordering rules.
+ *
+ * TODO:
+ * - enforce NFS4ERR_NOT_ONLY_OP,
+ * - DESTROY_SESSION MUST be the final operation in the COMPOUND request.
+ */
+static bool nfs41_op_ordering_ok(struct nfsd4_compoundargs *args)
+{
+       if (args->minorversion && args->opcnt > 0) {
+               struct nfsd4_op *op = &args->ops[0];
+               return (op->status == nfserr_op_illegal) ||
+                      (nfsd4_ops[op->opnum].op_flags & ALLOWED_AS_FIRST_OP);
+       }
+       return true;
+}
+
 /*
  * COMPOUND call.
  */
@@ -864,6 +882,12 @@ nfsd4_proc_compound(struct svc_rqst *rqstp,
        if (args->minorversion > NFSD_SUPPORTED_MINOR_VERSION)
                goto out;
 
+       if (!nfs41_op_ordering_ok(args)) {
+               op = &args->ops[0];
+               op->status = nfserr_sequence_pos;
+               goto encode_op;
+       }
+
        status = nfs_ok;
        while (!status && resp->opcnt < args->opcnt) {
                op = &args->ops[resp->opcnt++];
@@ -1105,22 +1129,22 @@ static struct nfsd4_operation nfsd4_ops[] = {
        /* NFSv4.1 operations */
        [OP_EXCHANGE_ID] = {
                .op_func = (nfsd4op_func)nfsd4_exchange_id,
-               .op_flags = ALLOWED_WITHOUT_FH,
+               .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP,
                .op_name = "OP_EXCHANGE_ID",
        },
        [OP_CREATE_SESSION] = {
                .op_func = (nfsd4op_func)nfsd4_create_session,
-               .op_flags = ALLOWED_WITHOUT_FH,
+               .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP,
                .op_name = "OP_CREATE_SESSION",
        },
        [OP_DESTROY_SESSION] = {
                .op_func = (nfsd4op_func)nfsd4_destroy_session,
-               .op_flags = ALLOWED_WITHOUT_FH,
+               .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP,
                .op_name = "OP_DESTROY_SESSION",
        },
        [OP_SEQUENCE] = {
                .op_func = (nfsd4op_func)nfsd4_sequence,
-               .op_flags = ALLOWED_WITHOUT_FH,
+               .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP,
                .op_name = "OP_SEQUENCE",
        },
 };

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 24b6e05..9243dca 100644 (file)
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1047,10 +1047,14 @@ nfsd4_sequence(struct svc_rqst *rqstp,
               struct nfsd4_compound_state *cstate,
               struct nfsd4_sequence *seq)
 {
+       struct nfsd4_compoundres *resp = rqstp->rq_resp;
        struct nfsd4_session *session;
        struct nfsd4_slot *slot;
        int status;
 
+       if (resp->opcnt != 1)
+               return nfserr_sequence_pos;
+
        spin_lock(&sessionid_lock);
        status = nfserr_badsession;
        session = find_in_sessionid_hashtbl(&seq->sessionid);