Introduce a new set of XDR encoding/decoding functions for NFSv2 basic
types that operate on xdr_streams. Use coding style similar to what's
in fs/nfs/nfs4xdr.c.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
fs/nfs/nfs2xdr.c | 342 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 342 insertions(+), 0 deletions(-)
diff --git a/fs/nfs/nfs2xdr.c b/fs/nfs/nfs2xdr.c
index 279883c..9d5159f 100644
--- a/fs/nfs/nfs2xdr.c
+++ b/fs/nfs/nfs2xdr.c
@@ -3,6 +3,11 @@
*
* XDR functions to encode/decode NFS RPC arguments and results.
*
+ * NFSv2 argument and result types are defined in section 2.2 of
+ * RFC 1094: "NFS: Network File System Protocol Specification".
+ * Basic data types are defined in section 2.3 of RFC 1094.
+ *
+ *
* Copyright (C) 1992, 1993, 1994 Rick Sladkey
* Copyright (C) 1996 Olaf Kirch
* 04 Aug 1998 Ion Badulescu <ionut@xxxxxxxxxxxxxxx>
@@ -61,6 +66,343 @@
#define NFS_readdirres_sz (1)
#define NFS_statfsres_sz (1+NFS_info_sz)
+static void print_overflow_msg(const char *func, const struct xdr_stream *xdr)
+{
+ dprintk("NFS: %s: prematurely hit end of receive buffer. "
+ "Remaining buffer length is %tu workds.\n",
+ func, xdr->end - xdr->p);
+}
+
+/*
+ * Encode/decode NFSv2 basic data types
+ *
+ * Not all basic data types have their own encoding and decoding
+ * functions. For run-time efficiency, some data types are encoded
+ * or decoded inline.
+ */
+
+/*
+ * 2.3.1. stat
+ *
+ * enum stat {
+ * NFS_OK = 0,
+ * ...
+ * }
+ */
+static int decode_stat(struct xdr_stream *xdr, enum nfs_stat *status)
+{
+ __be32 *p;
+
+ p = xdr_inline_decode(xdr, 4);
+ if (unlikely(p == NULL)) {
+ print_overflow_msg(__func__, xdr);
+ return -EIO;
+ }
+ *status = be32_to_cpup(p);
+ return 0;
+}
+
+/*
+ * 2.3.3. fhandle
+ *
+ * typedef opaque fhandle[FHSIZE];
+ */
+static void encode_fhandle(struct xdr_stream *xdr, const struct nfs_fh *fh)
+{
+ __be32 *p;
+
+ BUG_ON(unlikely(fh->size != NFS2_FHSIZE));
+ p = xdr_reserve_space(xdr, NFS2_FHSIZE);
+ BUG_ON(unlikely(p == NULL));
+ xdr_encode_opaque_fixed(p, &fh->data, NFS2_FHSIZE);
+}
+
+static int decode_fhandle(struct xdr_stream *xdr, struct nfs_fh *fh)
+{
+ __be32 *p;
+
+ p = xdr_inline_decode(xdr, NFS2_FHSIZE);
+ if (unlikely(p == NULL)) {
+ print_overflow_msg(__func__, xdr);
+ return -EIO;
+ }
+ memcpy(&fh->data, p, NFS2_FHSIZE);
+ fh->size = NFS2_FHSIZE;
+ return 0;
+}
+
+/*
+ * 2.3.4. timeval
+ *
+ * struct timeval {
+ * unsigned int seconds;
+ * unsigned int useconds;
+ * };
+ */
+static void encode_timeval(struct xdr_stream *xdr, const struct timespec *timep)
+{
+ __be32 *p;
+ u32 usec;
+
+ p = xdr_reserve_space(xdr, 8);
+ BUG_ON(unlikely(p == NULL));
+ usec = timep->tv_nsec ? (timep->tv_nsec / NSEC_PER_USEC) : 0;
+ *p++ = cpu_to_be32(timep->tv_sec);
+ *p = cpu_to_be32(usec);
+}
+
+/*
+ * Passing the invalid value useconds=1000000 is a Sun convention
+ * for "set to current server time". It's needed to make
+ * permissions checks for the "touch" program across v2 mounts to
+ * Solaris and Irix servers work correctly. Note that this is not
+ * discussed in RFC 1094; see description of sattr in section 6.1
+ * of "NFS Illustrated" by Brent Callaghan, Addison-Wesley,
+ * ISBN 0-201-32750-5
+ */
+static void encode_current_server_timeval(struct xdr_stream *xdr,
+ const struct timespec *timep)
+{
+ __be32 *p;
+
+ p = xdr_reserve_space(xdr, 8);
+ BUG_ON(unlikely(p == NULL));
+ *p++ = cpu_to_be32(timep->tv_sec);
+ *p = cpu_to_be32(1000000);
+}
+
+/*
+ * 2.3.5. fattr
+ *
+ * struct fattr {
+ * ftype type;
+ * unsigned int mode;
+ * unsigned int nlink;
+ * unsigned int uid;
+ * unsigned int gid;
+ * unsigned int size;
+ * unsigned int blocksize;
+ * unsigned int rdev;
+ * unsigned int blocks;
+ * unsigned int fsid;
+ * unsigned int fileid;
+ * timeval atime;
+ * timeval mtime;
+ * timeval ctime;
+ * };
+ *
+ */
+static int decode_fattr(struct xdr_stream *xdr, struct nfs_fattr *fattr)
+{
+ u32 rdev, type;
+ __be32 *p;
+
+ p = xdr_inline_decode(xdr, NFS_fattr_sz << 2);
+ if (unlikely(p == NULL)) {
+ print_overflow_msg(__func__, xdr);
+ return -EIO;
+ }
+
+ fattr->valid |= NFS_ATTR_FATTR;
+
+ type = be32_to_cpup(p++); /* 2.3.2. ftype */
+ if (unlikely(type > NF2FIFO))
+ type = NFBAD;
+
+ fattr->mode = be32_to_cpup(p++);
+ fattr->nlink = be32_to_cpup(p++);
+ fattr->uid = be32_to_cpup(p++);
+ fattr->gid = be32_to_cpup(p++);
+ fattr->size = be32_to_cpup(p++);
+ fattr->du.nfs2.blocksize = be32_to_cpup(p++);
+ rdev = be32_to_cpup(p++);
+ fattr->rdev = new_decode_dev(rdev);
+ fattr->du.nfs2.blocks = be32_to_cpup(p++);
+ fattr->fsid.major = be32_to_cpup(p++);
+ fattr->fsid.minor = 0;
+ fattr->fileid = be32_to_cpup(p++);
+
+ /* 2.3.4. timeval */
+ fattr->atime.tv_sec = be32_to_cpup(p++);
+ fattr->atime.tv_nsec = be32_to_cpup(p++) * NSEC_PER_USEC;
+
+ /* 2.3.4. timeval */
+ fattr->mtime.tv_sec = be32_to_cpup(p++);
+ fattr->mtime.tv_nsec = be32_to_cpup(p++) * NSEC_PER_USEC;
+
+ /* 2.3.4. timeval */
+ fattr->ctime.tv_sec = be32_to_cpup(p++);
+ fattr->ctime.tv_nsec = be32_to_cpup(p++) * NSEC_PER_USEC;
+
+ /*
+ * RFC 1094 section 2.3.2 suggests that NF2SOCK and NF2FIFO
+ * are not supported by version 2 of the protocol.
+ */
+ if (type == (u32)NFCHR && rdev == (u32)NFS2_FIFO_DEV) {
+ fattr->mode = (fattr->mode & ~S_IFMT) | S_IFIFO;
+ fattr->rdev = 0;
+ }
+
+ return 0;
+}
+
+/*
+ * 2.3.6. sattr
+ *
+ * struct sattr {
+ * unsigned int mode;
+ * unsigned int uid;
+ * unsigned int gid;
+ * unsigned int size;
+ * timeval atime;
+ * timeval mtime;
+ * };
+ */
+
+#define NFS2_SATTR_NOT_SET (0xffffffff)
+
+static void encode_time_not_set(struct xdr_stream *xdr)
+{
+ __be32 *p;
+
+ p = xdr_reserve_space(xdr, 8);
+ BUG_ON(unlikely(p == NULL));
+ *p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
+ *p = cpu_to_be32(NFS2_SATTR_NOT_SET);
+}
+
+static void encode_sattr(struct xdr_stream *xdr, const struct iattr *attr)
+{
+ unsigned int valid = attr->ia_valid;
+ __be32 *p;
+
+ p = xdr_reserve_space(xdr, 16);
+ BUG_ON(unlikely(p == NULL));
+ if (valid & ATTR_MODE)
+ *p++ = cpu_to_be32(attr->ia_mode);
+ else
+ *p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
+ if (valid & ATTR_UID)
+ *p++ = cpu_to_be32(attr->ia_uid);
+ else
+ *p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
+ if (valid & ATTR_GID)
+ *p++ = cpu_to_be32(attr->ia_gid);
+ else
+ *p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
+ if (valid & ATTR_SIZE)
+ *p++ = cpu_to_be32((u32)attr->ia_size);
+ else
+ *p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
+
+ if (valid & ATTR_ATIME_SET)
+ encode_timeval(xdr, &attr->ia_atime);
+ else if (valid & ATTR_ATIME)
+ encode_current_server_timeval(xdr, &attr->ia_atime);
+ else
+ encode_time_not_set(xdr);
+ if (valid & ATTR_MTIME_SET)
+ encode_timeval(xdr, &attr->ia_mtime);
+ else if (valid & ATTR_MTIME)
+ encode_current_server_timeval(xdr, &attr->ia_mtime);
+ else
+ encode_time_not_set(xdr);
+}
+
+/*
+ * 2.3.7. filename
+ *
+ * typedef string filename<MAXNAMLEN>;
+ */
+static void encode_filename(struct xdr_stream *xdr, const char *name, u32 count)
+{
+ __be32 *p;
+
+ BUG_ON(unlikely(count > NFS2_MAXNAMLEN));
+ p = xdr_reserve_space(xdr, 4 + count);
+ BUG_ON(unlikely(p == NULL));
+ *p++ = cpu_to_be32(count);
+ xdr_encode_opaque_fixed(p, name, count);
+}
+
+/*
+ * 2.3.8. path
+ *
+ * typedef string path<MAXPATHLEN>;
+ */
+static void encode_path(struct xdr_stream *xdr, struct page **pages, u32 count)
+{
+ __be32 *p;
+
+ BUG_ON(count > NFS_MAXPATHLEN);
+ p = xdr_reserve_space(xdr, 4);
+ BUG_ON(unlikely(p == NULL));
+ *p = cpu_to_be32(count);
+ xdr_write_pages(xdr, pages, 0, count);
+}
+
+static int decode_path(struct xdr_stream *xdr)
+{
+ u32 recvd, count;
+ size_t hdrlen;
+ __be32 *p;
+
+ p = xdr_inline_decode(xdr, 4);
+ if (unlikely(p == NULL)) {
+ print_overflow_msg(__func__, xdr);
+ return -EIO;
+ }
+ count = be32_to_cpup(p);
+
+ if (count >= xdr->buf->page_len || count > NFS_MAXPATHLEN) {
+ dprintk("NFS: server returned giant pathname!\n");
+ return -ENAMETOOLONG;
+ }
+ hdrlen = (u8 *)xdr->p - (u8 *)xdr->iov->iov_base;
+ recvd = xdr->buf->len - hdrlen;
+ if (count > recvd) {
+ dprintk("NFS: server cheating in pathname result: "
+ "count %u > recvd %u\n", count, recvd);
+ return -EIO;
+ }
+
+ xdr_read_pages(xdr, count);
+ xdr_terminate_string(xdr->buf, count);
+ return 0;
+}
+
+/*
+ * 2.3.10. diropargs
+ *
+ * struct diropargs {
+ * fhandle dir;
+ * filename name;
+ * };
+ */
+static void encode_diropargs(struct xdr_stream *xdr, const struct nfs_fh *fh,
+ const char *name, u32 count)
+{
+ encode_fhandle(xdr, fh);
+ encode_filename(xdr, name, count);
+}
+
+/*
+ * 2.3.11. diropok
+ *
+ * struct {
+ * fhandle file;
+ * fattr attributes;
+ * } diropok;
+ */
+static int decode_diropok(struct xdr_stream *xdr, struct nfs_fh *fh,
+ struct nfs_fattr *fattr)
+{
+ if (decode_fhandle(xdr, fh) != 0)
+ return -EIO;
+ return decode_fattr(xdr, fattr);
+}
+
+
/*
* Common NFS XDR functions as inlines
*/
--
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