NFSD: Update XDR decoders in NFSv4 callback client

Clean up.

Remove old-style NFSv4 XDR macros in favor of the style now used in
fs/nfs/nfs4xdr.c.  These were forgotten during the recent nfs4xdr.c
rewrite.

Additional whitespace cleanup adds to the size of this patch.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 239 insertions, 176 deletions

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index d8148cc461e7..c3c6a903144c 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -74,37 +74,6 @@ enum {
                                         cb_sequence_dec_sz +            \
                                         op_dec_sz)
 
-/*
- * Generic decode routines from fs/nfs/nfs4xdr.c
- */
-#define DECODE_TAIL                             \
-        status = 0;                             \
-out:                                            \
-        return status;                          \
-xdr_error:                                      \
-        dprintk("NFSD: xdr error! (%s:%d)\n", __FILE__, __LINE__); \
-        status = -EIO;                          \
-        goto out
-
-#define READ32(x)         (x) = ntohl(*p++)
-#define READ64(x)         do {                  \
-        (x) = (u64)ntohl(*p++) << 32;           \
-        (x) |= ntohl(*p++);                     \
-} while (0)
-#define READTIME(x)       do {                  \
-        p++;                                    \
-        (x.tv_sec) = ntohl(*p++);               \
-        (x.tv_nsec) = ntohl(*p++);              \
-} while (0)
-#define READ_BUF(nbytes)  do { \
-        p = xdr_inline_decode(xdr, nbytes); \
-        if (!p) { \
-                dprintk("NFSD: %s: reply buffer overflowed in line %d.\n", \
-                        __func__, __LINE__); \
-                return -EIO; \
-        } \
-} while (0)
-
 struct nfs4_cb_compound_hdr {
         /* args */
         u32             ident;  /* minorversion 0 only */
@@ -115,57 +84,14 @@ struct nfs4_cb_compound_hdr {
         int             status;
 };
 
-static struct {
-int stat;
-int errno;
-} nfs_cb_errtbl[] = {
-        { NFS4_OK,              0               },
-        { NFS4ERR_PERM,         EPERM           },
-        { NFS4ERR_NOENT,        ENOENT          },
-        { NFS4ERR_IO,           EIO             },
-        { NFS4ERR_NXIO,         ENXIO           },
-        { NFS4ERR_ACCESS,       EACCES          },
-        { NFS4ERR_EXIST,        EEXIST          },
-        { NFS4ERR_XDEV,         EXDEV           },
-        { NFS4ERR_NOTDIR,       ENOTDIR         },
-        { NFS4ERR_ISDIR,        EISDIR          },
-        { NFS4ERR_INVAL,        EINVAL          },
-        { NFS4ERR_FBIG,         EFBIG           },
-        { NFS4ERR_NOSPC,        ENOSPC          },
-        { NFS4ERR_ROFS,         EROFS           },
-        { NFS4ERR_MLINK,        EMLINK          },
-        { NFS4ERR_NAMETOOLONG,  ENAMETOOLONG    },
-        { NFS4ERR_NOTEMPTY,     ENOTEMPTY       },
-        { NFS4ERR_DQUOT,        EDQUOT          },
-        { NFS4ERR_STALE,        ESTALE          },
-        { NFS4ERR_BADHANDLE,    EBADHANDLE      },
-        { NFS4ERR_BAD_COOKIE,   EBADCOOKIE      },
-        { NFS4ERR_NOTSUPP,      ENOTSUPP        },
-        { NFS4ERR_TOOSMALL,     ETOOSMALL       },
-        { NFS4ERR_SERVERFAULT,  ESERVERFAULT    },
-        { NFS4ERR_BADTYPE,      EBADTYPE        },
-        { NFS4ERR_LOCKED,       EAGAIN          },
-        { NFS4ERR_RESOURCE,     EREMOTEIO       },
-        { NFS4ERR_SYMLINK,      ELOOP           },
-        { NFS4ERR_OP_ILLEGAL,   EOPNOTSUPP      },
-        { NFS4ERR_DEADLOCK,     EDEADLK         },
-        { -1,                   EIO             }
-};
-
-static int
-nfs_cb_stat_to_errno(int stat)
+/*
+ * Handle decode buffer overflows out-of-line.
+ */
+static void print_overflow_msg(const char *func, const struct xdr_stream *xdr)
 {
-        int i;
-        for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
-                if (nfs_cb_errtbl[i].stat == stat)
-                        return nfs_cb_errtbl[i].errno;
-        }
-        /* If we cannot translate the error, the recovery routines should
-        * handle it.
-        * Note: remaining NFSv4 error codes have values > 10000, so should
-        * not conflict with native Linux error codes.
-        */
-        return stat;
+        dprintk("NFS: %s prematurely hit the end of our receive buffer. "
+                "Remaining buffer length is %tu words.\n",
+                func, xdr->end - xdr->p);
 }
 
 static __be32 *xdr_encode_empty_array(__be32 *p)
@@ -263,6 +189,89 @@ static void encode_sessionid4(struct xdr_stream *xdr,
 }
 
 /*
+ * nfsstat4
+ */
+static const struct {
+        int stat;
+        int errno;
+} nfs_cb_errtbl[] = {
+        { NFS4_OK,              0               },
+        { NFS4ERR_PERM,         -EPERM          },
+        { NFS4ERR_NOENT,        -ENOENT         },
+        { NFS4ERR_IO,           -EIO            },
+        { NFS4ERR_NXIO,         -ENXIO          },
+        { NFS4ERR_ACCESS,       -EACCES         },
+        { NFS4ERR_EXIST,        -EEXIST         },
+        { NFS4ERR_XDEV,         -EXDEV          },
+        { NFS4ERR_NOTDIR,       -ENOTDIR        },
+        { NFS4ERR_ISDIR,        -EISDIR         },
+        { NFS4ERR_INVAL,        -EINVAL         },
+        { NFS4ERR_FBIG,         -EFBIG          },
+        { NFS4ERR_NOSPC,        -ENOSPC         },
+        { NFS4ERR_ROFS,         -EROFS          },
+        { NFS4ERR_MLINK,        -EMLINK         },
+        { NFS4ERR_NAMETOOLONG,  -ENAMETOOLONG   },
+        { NFS4ERR_NOTEMPTY,     -ENOTEMPTY      },
+        { NFS4ERR_DQUOT,        -EDQUOT         },
+        { NFS4ERR_STALE,        -ESTALE         },
+        { NFS4ERR_BADHANDLE,    -EBADHANDLE     },
+        { NFS4ERR_BAD_COOKIE,   -EBADCOOKIE     },
+        { NFS4ERR_NOTSUPP,      -ENOTSUPP       },
+        { NFS4ERR_TOOSMALL,     -ETOOSMALL      },
+        { NFS4ERR_SERVERFAULT,  -ESERVERFAULT   },
+        { NFS4ERR_BADTYPE,      -EBADTYPE       },
+        { NFS4ERR_LOCKED,       -EAGAIN         },
+        { NFS4ERR_RESOURCE,     -EREMOTEIO      },
+        { NFS4ERR_SYMLINK,      -ELOOP          },
+        { NFS4ERR_OP_ILLEGAL,   -EOPNOTSUPP     },
+        { NFS4ERR_DEADLOCK,     -EDEADLK        },
+        { -1,                   -EIO            }
+};
+
+/*
+ * If we cannot translate the error, the recovery routines should
+ * handle it.
+ *
+ * Note: remaining NFSv4 error codes have values > 10000, so should
+ * not conflict with native Linux error codes.
+ */
+static int nfs_cb_stat_to_errno(int status)
+{
+        int i;
+
+        for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
+                if (nfs_cb_errtbl[i].stat == status)
+                        return nfs_cb_errtbl[i].errno;
+        }
+
+        dprintk("NFSD: Unrecognized NFS CB status value: %u\n", status);
+        return -status;
+}
+
+static int decode_cb_op_status(struct xdr_stream *xdr, enum nfs_opnum4 expected,
+                               enum nfsstat4 *status)
+{
+        __be32 *p;
+        u32 op;
+
+        p = xdr_inline_decode(xdr, 4 + 4);
+        if (unlikely(p == NULL))
+                goto out_overflow;
+        op = be32_to_cpup(p++);
+        if (unlikely(op != expected))
+                goto out_unexpected;
+        *status = be32_to_cpup(p);
+        return 0;
+out_overflow:
+        print_overflow_msg(__func__, xdr);
+        return -EIO;
+out_unexpected:
+        dprintk("NFSD: Callback server returned operation %d but "
+                "we issued a request for %d\n", op, expected);
+        return -EIO;
+}
+
+/*
  * CB_COMPOUND4args
  *
  *      struct CB_COMPOUND4args {
@@ -296,6 +305,37 @@ static void encode_cb_nops(struct nfs4_cb_compound_hdr *hdr)
 }
 
 /*
+ * CB_COMPOUND4res
+ *
+ *      struct CB_COMPOUND4res {
+ *              nfsstat4        status;
+ *              utf8str_cs      tag;
+ *              nfs_cb_resop4   resarray<>;
+ *      };
+ */
+static int decode_cb_compound4res(struct xdr_stream *xdr,
+                                  struct nfs4_cb_compound_hdr *hdr)
+{
+        u32 length;
+        __be32 *p;
+
+        p = xdr_inline_decode(xdr, 4 + 4);
+        if (unlikely(p == NULL))
+                goto out_overflow;
+        hdr->status = be32_to_cpup(p++);
+        /* Ignore the tag */
+        length = be32_to_cpup(p++);
+        p = xdr_inline_decode(xdr, length + 4);
+        if (unlikely(p == NULL))
+                goto out_overflow;
+        hdr->nops = be32_to_cpup(p);
+        return 0;
+out_overflow:
+        print_overflow_msg(__func__, xdr);
+        return -EIO;
+}
+
+/*
  * CB_RECALL4args
  *
  *      struct CB_RECALL4args {
@@ -357,6 +397,97 @@ static void encode_cb_sequence4args(struct xdr_stream *xdr,
 }
 
 /*
+ * CB_SEQUENCE4resok
+ *
+ *      struct CB_SEQUENCE4resok {
+ *              sessionid4      csr_sessionid;
+ *              sequenceid4     csr_sequenceid;
+ *              slotid4         csr_slotid;
+ *              slotid4         csr_highest_slotid;
+ *              slotid4         csr_target_highest_slotid;
+ *      };
+ *
+ *      union CB_SEQUENCE4res switch (nfsstat4 csr_status) {
+ *      case NFS4_OK:
+ *              CB_SEQUENCE4resok       csr_resok4;
+ *      default:
+ *              void;
+ *      };
+ *
+ * Our current back channel implmentation supports a single backchannel
+ * with a single slot.
+ */
+static int decode_cb_sequence4resok(struct xdr_stream *xdr,
+                                    struct nfsd4_callback *cb)
+{
+        struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
+        struct nfs4_sessionid id;
+        int status;
+        __be32 *p;
+        u32 dummy;
+
+        status = -ESERVERFAULT;
+
+        /*
+         * If the server returns different values for sessionID, slotID or
+         * sequence number, the server is looney tunes.
+         */
+        p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN + 4 + 4);
+        if (unlikely(p == NULL))
+                goto out_overflow;
+        memcpy(id.data, p, NFS4_MAX_SESSIONID_LEN);
+        if (memcmp(id.data, session->se_sessionid.data,
+                                        NFS4_MAX_SESSIONID_LEN) != 0) {
+                dprintk("NFS: %s Invalid session id\n", __func__);
+                goto out;
+        }
+        p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN);
+
+        dummy = be32_to_cpup(p++);
+        if (dummy != session->se_cb_seq_nr) {
+                dprintk("NFS: %s Invalid sequence number\n", __func__);
+                goto out;
+        }
+
+        dummy = be32_to_cpup(p++);
+        if (dummy != 0) {
+                dprintk("NFS: %s Invalid slotid\n", __func__);
+                goto out;
+        }
+
+        /*
+         * FIXME: process highest slotid and target highest slotid
+         */
+        status = 0;
+out:
+        return status;
+out_overflow:
+        print_overflow_msg(__func__, xdr);
+        return -EIO;
+}
+
+static int decode_cb_sequence4res(struct xdr_stream *xdr,
+                                  struct nfsd4_callback *cb)
+{
+        enum nfsstat4 nfserr;
+        int status;
+
+        if (cb->cb_minorversion == 0)
+                return 0;
+
+        status = decode_cb_op_status(xdr, OP_CB_SEQUENCE, &nfserr);
+        if (unlikely(status))
+                goto out;
+        if (unlikely(nfserr != NFS4_OK))
+                goto out_default;
+        status = decode_cb_sequence4resok(xdr, cb);
+out:
+        return status;
+out_default:
+        return nfs_cb_stat_to_errno(status);
+}
+
+/*
  * NFSv4.0 and NFSv4.1 XDR encode functions
  *
  * NFSv4.0 callback argument types are defined in section 15 of RFC
@@ -399,119 +530,51 @@ static int nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, __be32 *p,
 }
 
 
-static int
-decode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr){
-        __be32 *p;
-        u32 taglen;
-
-        READ_BUF(8);
-        READ32(hdr->status);
-        /* We've got no use for the tag; ignore it: */
-        READ32(taglen);
-        READ_BUF(taglen + 4);
-        p += XDR_QUADLEN(taglen);
-        READ32(hdr->nops);
-        return 0;
-}
-
-static int
-decode_cb_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 expected)
-{
-        __be32 *p;
-        u32 op;
-        int32_t nfserr;
-
-        READ_BUF(8);
-        READ32(op);
-        if (op != expected) {
-                dprintk("NFSD: decode_cb_op_hdr: Callback server returned "
-                         " operation %d but we issued a request for %d\n",
-                         op, expected);
-                return -EIO;
-        }
-        READ32(nfserr);
-        if (nfserr != NFS_OK)
-                return -nfs_cb_stat_to_errno(nfserr);
-        return 0;
-}
-
 /*
- * Our current back channel implmentation supports a single backchannel
- * with a single slot.
+ * NFSv4.0 and NFSv4.1 XDR decode functions
+ *
+ * NFSv4.0 callback result types are defined in section 15 of RFC
+ * 3530: "Network File System (NFS) version 4 Protocol" and section 20
+ * of RFC 5661:  "Network File System (NFS) Version 4 Minor Version 1
+ * Protocol".
  */
-static int
-decode_cb_sequence(struct xdr_stream *xdr, struct nfsd4_callback *cb,
-                   struct rpc_rqst *rqstp)
-{
-        struct nfsd4_session *ses = cb->cb_clp->cl_cb_session;
-        struct nfs4_sessionid id;
-        int status;
-        u32 dummy;
-        __be32 *p;
-
-        if (cb->cb_minorversion == 0)
-                return 0;
-
-        status = decode_cb_op_hdr(xdr, OP_CB_SEQUENCE);
-        if (status)
-                return status;
-
-        /*
-         * If the server returns different values for sessionID, slotID or
-         * sequence number, the server is looney tunes.
-         */
-        status = -ESERVERFAULT;
-
-        READ_BUF(NFS4_MAX_SESSIONID_LEN + 16);
-        memcpy(id.data, p, NFS4_MAX_SESSIONID_LEN);
-        p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN);
-        if (memcmp(id.data, ses->se_sessionid.data, NFS4_MAX_SESSIONID_LEN)) {
-                dprintk("%s Invalid session id\n", __func__);
-                goto out;
-        }
-        READ32(dummy);
-        if (dummy != ses->se_cb_seq_nr) {
-                dprintk("%s Invalid sequence number\n", __func__);
-                goto out;
-        }
-        READ32(dummy);  /* slotid must be 0 */
-        if (dummy != 0) {
-                dprintk("%s Invalid slotid\n", __func__);
-                goto out;
-        }
-        /* FIXME: process highest slotid and target highest slotid */
-        status = 0;
-out:
-        return status;
-}
-
 
-static int
-nfs4_xdr_dec_cb_null(struct rpc_rqst *req, __be32 *p)
+static int nfs4_xdr_dec_cb_null(struct rpc_rqst *req, __be32 *p, void *__unused)
 {
         return 0;
 }
 
-static int
-nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp, __be32 *p,
-                struct nfsd4_callback *cb)
+/*
+ * 20.2. Operation 4: CB_RECALL - Recall a Delegation
+ */
+static int nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp, __be32 *p,
+                                  struct nfsd4_callback *cb)
 {
         struct xdr_stream xdr;
         struct nfs4_cb_compound_hdr hdr;
+        enum nfsstat4 nfserr;
         int status;
 
         xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
-        status = decode_cb_compound_hdr(&xdr, &hdr);
-        if (status)
+        status = decode_cb_compound4res(&xdr, &hdr);
+        if (unlikely(status))
                 goto out;
-        if (cb) {
-                status = decode_cb_sequence(&xdr, cb, rqstp);
-                if (status)
+
+        if (cb != NULL) {
+                status = decode_cb_sequence4res(&xdr, cb);
+                if (unlikely(status))
                         goto out;
         }
-        status = decode_cb_op_hdr(&xdr, OP_CB_RECALL);
+
+        status = decode_cb_op_status(&xdr, OP_CB_RECALL, &nfserr);
+        if (unlikely(status))
+                goto out;
+        if (unlikely(nfserr != NFS4_OK))
+                goto out_default;
 out:
         return status;
+out_default:
+        return nfs_cb_stat_to_errno(status);
 }
 
 /*