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-rw-r--r--fs/nfsd/nfsxdr.c663
1 files changed, 663 insertions, 0 deletions
diff --git a/fs/nfsd/nfsxdr.c b/fs/nfsd/nfsxdr.c
new file mode 100644
index 0000000000..5777f40c73
--- /dev/null
+++ b/fs/nfsd/nfsxdr.c
@@ -0,0 +1,663 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * XDR support for nfsd
+ *
+ * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include "vfs.h"
+#include "xdr.h"
+#include "auth.h"
+
+/*
+ * Mapping of S_IF* types to NFS file types
+ */
+static const u32 nfs_ftypes[] = {
+ NFNON, NFCHR, NFCHR, NFBAD,
+ NFDIR, NFBAD, NFBLK, NFBAD,
+ NFREG, NFBAD, NFLNK, NFBAD,
+ NFSOCK, NFBAD, NFLNK, NFBAD,
+};
+
+
+/*
+ * Basic NFSv2 data types (RFC 1094 Section 2.3)
+ */
+
+/**
+ * svcxdr_encode_stat - Encode an NFSv2 status code
+ * @xdr: XDR stream
+ * @status: status value to encode
+ *
+ * Return values:
+ * %false: Send buffer space was exhausted
+ * %true: Success
+ */
+bool
+svcxdr_encode_stat(struct xdr_stream *xdr, __be32 status)
+{
+ __be32 *p;
+
+ p = xdr_reserve_space(xdr, sizeof(status));
+ if (!p)
+ return false;
+ *p = status;
+
+ return true;
+}
+
+/**
+ * svcxdr_decode_fhandle - Decode an NFSv2 file handle
+ * @xdr: XDR stream positioned at an encoded NFSv2 FH
+ * @fhp: OUT: filled-in server file handle
+ *
+ * Return values:
+ * %false: The encoded file handle was not valid
+ * %true: @fhp has been initialized
+ */
+bool
+svcxdr_decode_fhandle(struct xdr_stream *xdr, struct svc_fh *fhp)
+{
+ __be32 *p;
+
+ p = xdr_inline_decode(xdr, NFS_FHSIZE);
+ if (!p)
+ return false;
+ fh_init(fhp, NFS_FHSIZE);
+ memcpy(&fhp->fh_handle.fh_raw, p, NFS_FHSIZE);
+ fhp->fh_handle.fh_size = NFS_FHSIZE;
+
+ return true;
+}
+
+static bool
+svcxdr_encode_fhandle(struct xdr_stream *xdr, const struct svc_fh *fhp)
+{
+ __be32 *p;
+
+ p = xdr_reserve_space(xdr, NFS_FHSIZE);
+ if (!p)
+ return false;
+ memcpy(p, &fhp->fh_handle.fh_raw, NFS_FHSIZE);
+
+ return true;
+}
+
+static __be32 *
+encode_timeval(__be32 *p, const struct timespec64 *time)
+{
+ *p++ = cpu_to_be32((u32)time->tv_sec);
+ if (time->tv_nsec)
+ *p++ = cpu_to_be32(time->tv_nsec / NSEC_PER_USEC);
+ else
+ *p++ = xdr_zero;
+ return p;
+}
+
+static bool
+svcxdr_decode_filename(struct xdr_stream *xdr, char **name, unsigned int *len)
+{
+ u32 size, i;
+ __be32 *p;
+ char *c;
+
+ if (xdr_stream_decode_u32(xdr, &size) < 0)
+ return false;
+ if (size == 0 || size > NFS_MAXNAMLEN)
+ return false;
+ p = xdr_inline_decode(xdr, size);
+ if (!p)
+ return false;
+
+ *len = size;
+ *name = (char *)p;
+ for (i = 0, c = *name; i < size; i++, c++)
+ if (*c == '\0' || *c == '/')
+ return false;
+
+ return true;
+}
+
+static bool
+svcxdr_decode_diropargs(struct xdr_stream *xdr, struct svc_fh *fhp,
+ char **name, unsigned int *len)
+{
+ return svcxdr_decode_fhandle(xdr, fhp) &&
+ svcxdr_decode_filename(xdr, name, len);
+}
+
+static bool
+svcxdr_decode_sattr(struct svc_rqst *rqstp, struct xdr_stream *xdr,
+ struct iattr *iap)
+{
+ u32 tmp1, tmp2;
+ __be32 *p;
+
+ p = xdr_inline_decode(xdr, XDR_UNIT * 8);
+ if (!p)
+ return false;
+
+ iap->ia_valid = 0;
+
+ /*
+ * Some Sun clients put 0xffff in the mode field when they
+ * mean 0xffffffff.
+ */
+ tmp1 = be32_to_cpup(p++);
+ if (tmp1 != (u32)-1 && tmp1 != 0xffff) {
+ iap->ia_valid |= ATTR_MODE;
+ iap->ia_mode = tmp1;
+ }
+
+ tmp1 = be32_to_cpup(p++);
+ if (tmp1 != (u32)-1) {
+ iap->ia_uid = make_kuid(nfsd_user_namespace(rqstp), tmp1);
+ if (uid_valid(iap->ia_uid))
+ iap->ia_valid |= ATTR_UID;
+ }
+
+ tmp1 = be32_to_cpup(p++);
+ if (tmp1 != (u32)-1) {
+ iap->ia_gid = make_kgid(nfsd_user_namespace(rqstp), tmp1);
+ if (gid_valid(iap->ia_gid))
+ iap->ia_valid |= ATTR_GID;
+ }
+
+ tmp1 = be32_to_cpup(p++);
+ if (tmp1 != (u32)-1) {
+ iap->ia_valid |= ATTR_SIZE;
+ iap->ia_size = tmp1;
+ }
+
+ tmp1 = be32_to_cpup(p++);
+ tmp2 = be32_to_cpup(p++);
+ if (tmp1 != (u32)-1 && tmp2 != (u32)-1) {
+ iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
+ iap->ia_atime.tv_sec = tmp1;
+ iap->ia_atime.tv_nsec = tmp2 * NSEC_PER_USEC;
+ }
+
+ tmp1 = be32_to_cpup(p++);
+ tmp2 = be32_to_cpup(p++);
+ if (tmp1 != (u32)-1 && tmp2 != (u32)-1) {
+ iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
+ iap->ia_mtime.tv_sec = tmp1;
+ iap->ia_mtime.tv_nsec = tmp2 * NSEC_PER_USEC;
+ /*
+ * Passing the invalid value useconds=1000000 for mtime
+ * is a Sun convention for "set both mtime and atime to
+ * current server time". It's needed to make permissions
+ * checks for the "touch" program across v2 mounts to
+ * Solaris and Irix boxes work correctly. See description of
+ * sattr in section 6.1 of "NFS Illustrated" by
+ * Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5
+ */
+ if (tmp2 == 1000000)
+ iap->ia_valid &= ~(ATTR_ATIME_SET|ATTR_MTIME_SET);
+ }
+
+ return true;
+}
+
+/**
+ * svcxdr_encode_fattr - Encode NFSv2 file attributes
+ * @rqstp: Context of a completed RPC transaction
+ * @xdr: XDR stream
+ * @fhp: File handle to encode
+ * @stat: Attributes to encode
+ *
+ * Return values:
+ * %false: Send buffer space was exhausted
+ * %true: Success
+ */
+bool
+svcxdr_encode_fattr(struct svc_rqst *rqstp, struct xdr_stream *xdr,
+ const struct svc_fh *fhp, const struct kstat *stat)
+{
+ struct user_namespace *userns = nfsd_user_namespace(rqstp);
+ struct dentry *dentry = fhp->fh_dentry;
+ int type = stat->mode & S_IFMT;
+ struct timespec64 time;
+ __be32 *p;
+ u32 fsid;
+
+ p = xdr_reserve_space(xdr, XDR_UNIT * 17);
+ if (!p)
+ return false;
+
+ *p++ = cpu_to_be32(nfs_ftypes[type >> 12]);
+ *p++ = cpu_to_be32((u32)stat->mode);
+ *p++ = cpu_to_be32((u32)stat->nlink);
+ *p++ = cpu_to_be32((u32)from_kuid_munged(userns, stat->uid));
+ *p++ = cpu_to_be32((u32)from_kgid_munged(userns, stat->gid));
+
+ if (S_ISLNK(type) && stat->size > NFS_MAXPATHLEN)
+ *p++ = cpu_to_be32(NFS_MAXPATHLEN);
+ else
+ *p++ = cpu_to_be32((u32) stat->size);
+ *p++ = cpu_to_be32((u32) stat->blksize);
+ if (S_ISCHR(type) || S_ISBLK(type))
+ *p++ = cpu_to_be32(new_encode_dev(stat->rdev));
+ else
+ *p++ = cpu_to_be32(0xffffffff);
+ *p++ = cpu_to_be32((u32)stat->blocks);
+
+ switch (fsid_source(fhp)) {
+ case FSIDSOURCE_FSID:
+ fsid = (u32)fhp->fh_export->ex_fsid;
+ break;
+ case FSIDSOURCE_UUID:
+ fsid = ((u32 *)fhp->fh_export->ex_uuid)[0];
+ fsid ^= ((u32 *)fhp->fh_export->ex_uuid)[1];
+ fsid ^= ((u32 *)fhp->fh_export->ex_uuid)[2];
+ fsid ^= ((u32 *)fhp->fh_export->ex_uuid)[3];
+ break;
+ default:
+ fsid = new_encode_dev(stat->dev);
+ break;
+ }
+ *p++ = cpu_to_be32(fsid);
+
+ *p++ = cpu_to_be32((u32)stat->ino);
+ p = encode_timeval(p, &stat->atime);
+ time = stat->mtime;
+ lease_get_mtime(d_inode(dentry), &time);
+ p = encode_timeval(p, &time);
+ encode_timeval(p, &stat->ctime);
+
+ return true;
+}
+
+/*
+ * XDR decode functions
+ */
+
+bool
+nfssvc_decode_fhandleargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+ struct nfsd_fhandle *args = rqstp->rq_argp;
+
+ return svcxdr_decode_fhandle(xdr, &args->fh);
+}
+
+bool
+nfssvc_decode_sattrargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+ struct nfsd_sattrargs *args = rqstp->rq_argp;
+
+ return svcxdr_decode_fhandle(xdr, &args->fh) &&
+ svcxdr_decode_sattr(rqstp, xdr, &args->attrs);
+}
+
+bool
+nfssvc_decode_diropargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+ struct nfsd_diropargs *args = rqstp->rq_argp;
+
+ return svcxdr_decode_diropargs(xdr, &args->fh, &args->name, &args->len);
+}
+
+bool
+nfssvc_decode_readargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+ struct nfsd_readargs *args = rqstp->rq_argp;
+ u32 totalcount;
+
+ if (!svcxdr_decode_fhandle(xdr, &args->fh))
+ return false;
+ if (xdr_stream_decode_u32(xdr, &args->offset) < 0)
+ return false;
+ if (xdr_stream_decode_u32(xdr, &args->count) < 0)
+ return false;
+ /* totalcount is ignored */
+ if (xdr_stream_decode_u32(xdr, &totalcount) < 0)
+ return false;
+
+ return true;
+}
+
+bool
+nfssvc_decode_writeargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+ struct nfsd_writeargs *args = rqstp->rq_argp;
+ u32 beginoffset, totalcount;
+
+ if (!svcxdr_decode_fhandle(xdr, &args->fh))
+ return false;
+ /* beginoffset is ignored */
+ if (xdr_stream_decode_u32(xdr, &beginoffset) < 0)
+ return false;
+ if (xdr_stream_decode_u32(xdr, &args->offset) < 0)
+ return false;
+ /* totalcount is ignored */
+ if (xdr_stream_decode_u32(xdr, &totalcount) < 0)
+ return false;
+
+ /* opaque data */
+ if (xdr_stream_decode_u32(xdr, &args->len) < 0)
+ return false;
+ if (args->len > NFSSVC_MAXBLKSIZE_V2)
+ return false;
+
+ return xdr_stream_subsegment(xdr, &args->payload, args->len);
+}
+
+bool
+nfssvc_decode_createargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+ struct nfsd_createargs *args = rqstp->rq_argp;
+
+ return svcxdr_decode_diropargs(xdr, &args->fh,
+ &args->name, &args->len) &&
+ svcxdr_decode_sattr(rqstp, xdr, &args->attrs);
+}
+
+bool
+nfssvc_decode_renameargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+ struct nfsd_renameargs *args = rqstp->rq_argp;
+
+ return svcxdr_decode_diropargs(xdr, &args->ffh,
+ &args->fname, &args->flen) &&
+ svcxdr_decode_diropargs(xdr, &args->tfh,
+ &args->tname, &args->tlen);
+}
+
+bool
+nfssvc_decode_linkargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+ struct nfsd_linkargs *args = rqstp->rq_argp;
+
+ return svcxdr_decode_fhandle(xdr, &args->ffh) &&
+ svcxdr_decode_diropargs(xdr, &args->tfh,
+ &args->tname, &args->tlen);
+}
+
+bool
+nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+ struct nfsd_symlinkargs *args = rqstp->rq_argp;
+ struct kvec *head = rqstp->rq_arg.head;
+
+ if (!svcxdr_decode_diropargs(xdr, &args->ffh, &args->fname, &args->flen))
+ return false;
+ if (xdr_stream_decode_u32(xdr, &args->tlen) < 0)
+ return false;
+ if (args->tlen == 0)
+ return false;
+
+ args->first.iov_len = head->iov_len - xdr_stream_pos(xdr);
+ args->first.iov_base = xdr_inline_decode(xdr, args->tlen);
+ if (!args->first.iov_base)
+ return false;
+ return svcxdr_decode_sattr(rqstp, xdr, &args->attrs);
+}
+
+bool
+nfssvc_decode_readdirargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+ struct nfsd_readdirargs *args = rqstp->rq_argp;
+
+ if (!svcxdr_decode_fhandle(xdr, &args->fh))
+ return false;
+ if (xdr_stream_decode_u32(xdr, &args->cookie) < 0)
+ return false;
+ if (xdr_stream_decode_u32(xdr, &args->count) < 0)
+ return false;
+
+ return true;
+}
+
+/*
+ * XDR encode functions
+ */
+
+bool
+nfssvc_encode_statres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+ struct nfsd_stat *resp = rqstp->rq_resp;
+
+ return svcxdr_encode_stat(xdr, resp->status);
+}
+
+bool
+nfssvc_encode_attrstatres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+ struct nfsd_attrstat *resp = rqstp->rq_resp;
+
+ if (!svcxdr_encode_stat(xdr, resp->status))
+ return false;
+ switch (resp->status) {
+ case nfs_ok:
+ if (!svcxdr_encode_fattr(rqstp, xdr, &resp->fh, &resp->stat))
+ return false;
+ break;
+ }
+
+ return true;
+}
+
+bool
+nfssvc_encode_diropres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+ struct nfsd_diropres *resp = rqstp->rq_resp;
+
+ if (!svcxdr_encode_stat(xdr, resp->status))
+ return false;
+ switch (resp->status) {
+ case nfs_ok:
+ if (!svcxdr_encode_fhandle(xdr, &resp->fh))
+ return false;
+ if (!svcxdr_encode_fattr(rqstp, xdr, &resp->fh, &resp->stat))
+ return false;
+ break;
+ }
+
+ return true;
+}
+
+bool
+nfssvc_encode_readlinkres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+ struct nfsd_readlinkres *resp = rqstp->rq_resp;
+ struct kvec *head = rqstp->rq_res.head;
+
+ if (!svcxdr_encode_stat(xdr, resp->status))
+ return false;
+ switch (resp->status) {
+ case nfs_ok:
+ if (xdr_stream_encode_u32(xdr, resp->len) < 0)
+ return false;
+ svcxdr_encode_opaque_pages(rqstp, xdr, &resp->page, 0,
+ resp->len);
+ if (svc_encode_result_payload(rqstp, head->iov_len, resp->len) < 0)
+ return false;
+ break;
+ }
+
+ return true;
+}
+
+bool
+nfssvc_encode_readres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+ struct nfsd_readres *resp = rqstp->rq_resp;
+ struct kvec *head = rqstp->rq_res.head;
+
+ if (!svcxdr_encode_stat(xdr, resp->status))
+ return false;
+ switch (resp->status) {
+ case nfs_ok:
+ if (!svcxdr_encode_fattr(rqstp, xdr, &resp->fh, &resp->stat))
+ return false;
+ if (xdr_stream_encode_u32(xdr, resp->count) < 0)
+ return false;
+ svcxdr_encode_opaque_pages(rqstp, xdr, resp->pages,
+ rqstp->rq_res.page_base,
+ resp->count);
+ if (svc_encode_result_payload(rqstp, head->iov_len, resp->count) < 0)
+ return false;
+ break;
+ }
+
+ return true;
+}
+
+bool
+nfssvc_encode_readdirres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+ struct nfsd_readdirres *resp = rqstp->rq_resp;
+ struct xdr_buf *dirlist = &resp->dirlist;
+
+ if (!svcxdr_encode_stat(xdr, resp->status))
+ return false;
+ switch (resp->status) {
+ case nfs_ok:
+ svcxdr_encode_opaque_pages(rqstp, xdr, dirlist->pages, 0,
+ dirlist->len);
+ /* no more entries */
+ if (xdr_stream_encode_item_absent(xdr) < 0)
+ return false;
+ if (xdr_stream_encode_bool(xdr, resp->common.err == nfserr_eof) < 0)
+ return false;
+ break;
+ }
+
+ return true;
+}
+
+bool
+nfssvc_encode_statfsres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+ struct nfsd_statfsres *resp = rqstp->rq_resp;
+ struct kstatfs *stat = &resp->stats;
+ __be32 *p;
+
+ if (!svcxdr_encode_stat(xdr, resp->status))
+ return false;
+ switch (resp->status) {
+ case nfs_ok:
+ p = xdr_reserve_space(xdr, XDR_UNIT * 5);
+ if (!p)
+ return false;
+ *p++ = cpu_to_be32(NFSSVC_MAXBLKSIZE_V2);
+ *p++ = cpu_to_be32(stat->f_bsize);
+ *p++ = cpu_to_be32(stat->f_blocks);
+ *p++ = cpu_to_be32(stat->f_bfree);
+ *p = cpu_to_be32(stat->f_bavail);
+ break;
+ }
+
+ return true;
+}
+
+/**
+ * nfssvc_encode_nfscookie - Encode a directory offset cookie
+ * @resp: readdir result context
+ * @offset: offset cookie to encode
+ *
+ * The buffer space for the offset cookie has already been reserved
+ * by svcxdr_encode_entry_common().
+ */
+void nfssvc_encode_nfscookie(struct nfsd_readdirres *resp, u32 offset)
+{
+ __be32 cookie = cpu_to_be32(offset);
+
+ if (!resp->cookie_offset)
+ return;
+
+ write_bytes_to_xdr_buf(&resp->dirlist, resp->cookie_offset, &cookie,
+ sizeof(cookie));
+ resp->cookie_offset = 0;
+}
+
+static bool
+svcxdr_encode_entry_common(struct nfsd_readdirres *resp, const char *name,
+ int namlen, loff_t offset, u64 ino)
+{
+ struct xdr_buf *dirlist = &resp->dirlist;
+ struct xdr_stream *xdr = &resp->xdr;
+
+ if (xdr_stream_encode_item_present(xdr) < 0)
+ return false;
+ /* fileid */
+ if (xdr_stream_encode_u32(xdr, (u32)ino) < 0)
+ return false;
+ /* name */
+ if (xdr_stream_encode_opaque(xdr, name, min(namlen, NFS2_MAXNAMLEN)) < 0)
+ return false;
+ /* cookie */
+ resp->cookie_offset = dirlist->len;
+ if (xdr_stream_encode_u32(xdr, ~0U) < 0)
+ return false;
+
+ return true;
+}
+
+/**
+ * nfssvc_encode_entry - encode one NFSv2 READDIR entry
+ * @data: directory context
+ * @name: name of the object to be encoded
+ * @namlen: length of that name, in bytes
+ * @offset: the offset of the previous entry
+ * @ino: the fileid of this entry
+ * @d_type: unused
+ *
+ * Return values:
+ * %0: Entry was successfully encoded.
+ * %-EINVAL: An encoding problem occured, secondary status code in resp->common.err
+ *
+ * On exit, the following fields are updated:
+ * - resp->xdr
+ * - resp->common.err
+ * - resp->cookie_offset
+ */
+int nfssvc_encode_entry(void *data, const char *name, int namlen,
+ loff_t offset, u64 ino, unsigned int d_type)
+{
+ struct readdir_cd *ccd = data;
+ struct nfsd_readdirres *resp = container_of(ccd,
+ struct nfsd_readdirres,
+ common);
+ unsigned int starting_length = resp->dirlist.len;
+
+ /* The offset cookie for the previous entry */
+ nfssvc_encode_nfscookie(resp, offset);
+
+ if (!svcxdr_encode_entry_common(resp, name, namlen, offset, ino))
+ goto out_toosmall;
+
+ xdr_commit_encode(&resp->xdr);
+ resp->common.err = nfs_ok;
+ return 0;
+
+out_toosmall:
+ resp->cookie_offset = 0;
+ resp->common.err = nfserr_toosmall;
+ resp->dirlist.len = starting_length;
+ return -EINVAL;
+}
+
+/*
+ * XDR release functions
+ */
+void nfssvc_release_attrstat(struct svc_rqst *rqstp)
+{
+ struct nfsd_attrstat *resp = rqstp->rq_resp;
+
+ fh_put(&resp->fh);
+}
+
+void nfssvc_release_diropres(struct svc_rqst *rqstp)
+{
+ struct nfsd_diropres *resp = rqstp->rq_resp;
+
+ fh_put(&resp->fh);
+}
+
+void nfssvc_release_readres(struct svc_rqst *rqstp)
+{
+ struct nfsd_readres *resp = rqstp->rq_resp;
+
+ fh_put(&resp->fh);
+}