1 files changed, 569 insertions, 0 deletions

diff --git a/fs/nfsd/nfsxdr.c b/fs/nfsd/nfsxdr.c
new file mode 100644
index 000000000..6b2e8b73d
--- /dev/null
+++ b/fs/nfsd/nfsxdr.c
@@ -0,0 +1,569 @@
+// 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"
+
+#define NFSDDBG_FACILITY		NFSDDBG_XDR
+
+/*
+ * Mapping of S_IF* types to NFS file types
+ */
+static u32	nfs_ftypes[] = {
+	NFNON,  NFCHR,  NFCHR, NFBAD,
+	NFDIR,  NFBAD,  NFBLK, NFBAD,
+	NFREG,  NFBAD,  NFLNK, NFBAD,
+	NFSOCK, NFBAD,  NFLNK, NFBAD,
+};
+
+
+/*
+ * XDR functions for basic NFS types
+ */
+static __be32 *
+decode_fh(__be32 *p, struct svc_fh *fhp)
+{
+	fh_init(fhp, NFS_FHSIZE);
+	memcpy(&fhp->fh_handle.fh_base, p, NFS_FHSIZE);
+	fhp->fh_handle.fh_size = NFS_FHSIZE;
+
+	/* FIXME: Look up export pointer here and verify
+	 * Sun Secure RPC if requested */
+	return p + (NFS_FHSIZE >> 2);
+}
+
+/* Helper function for NFSv2 ACL code */
+__be32 *nfs2svc_decode_fh(__be32 *p, struct svc_fh *fhp)
+{
+	return decode_fh(p, fhp);
+}
+
+static __be32 *
+encode_fh(__be32 *p, struct svc_fh *fhp)
+{
+	memcpy(p, &fhp->fh_handle.fh_base, NFS_FHSIZE);
+	return p + (NFS_FHSIZE>> 2);
+}
+
+/*
+ * Decode a file name and make sure that the path contains
+ * no slashes or null bytes.
+ */
+static __be32 *
+decode_filename(__be32 *p, char **namp, unsigned int *lenp)
+{
+	char		*name;
+	unsigned int	i;
+
+	if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS_MAXNAMLEN)) != NULL) {
+		for (i = 0, name = *namp; i < *lenp; i++, name++) {
+			if (*name == '\0' || *name == '/')
+				return NULL;
+		}
+	}
+
+	return p;
+}
+
+static __be32 *
+decode_sattr(__be32 *p, struct iattr *iap)
+{
+	u32	tmp, tmp1;
+
+	iap->ia_valid = 0;
+
+	/* Sun client bug compatibility check: some sun clients seem to
+	 * put 0xffff in the mode field when they mean 0xffffffff.
+	 * Quoting the 4.4BSD nfs server code: Nah nah nah nah na nah.
+	 */
+	if ((tmp = ntohl(*p++)) != (u32)-1 && tmp != 0xffff) {
+		iap->ia_valid |= ATTR_MODE;
+		iap->ia_mode = tmp;
+	}
+	if ((tmp = ntohl(*p++)) != (u32)-1) {
+		iap->ia_uid = make_kuid(&init_user_ns, tmp);
+		if (uid_valid(iap->ia_uid))
+			iap->ia_valid |= ATTR_UID;
+	}
+	if ((tmp = ntohl(*p++)) != (u32)-1) {
+		iap->ia_gid = make_kgid(&init_user_ns, tmp);
+		if (gid_valid(iap->ia_gid))
+			iap->ia_valid |= ATTR_GID;
+	}
+	if ((tmp = ntohl(*p++)) != (u32)-1) {
+		iap->ia_valid |= ATTR_SIZE;
+		iap->ia_size = tmp;
+	}
+	tmp  = ntohl(*p++); tmp1 = ntohl(*p++);
+	if (tmp != (u32)-1 && tmp1 != (u32)-1) {
+		iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
+		iap->ia_atime.tv_sec = tmp;
+		iap->ia_atime.tv_nsec = tmp1 * 1000; 
+	}
+	tmp  = ntohl(*p++); tmp1 = ntohl(*p++);
+	if (tmp != (u32)-1 && tmp1 != (u32)-1) {
+		iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
+		iap->ia_mtime.tv_sec = tmp;
+		iap->ia_mtime.tv_nsec = tmp1 * 1000; 
+		/*
+		 * 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 (tmp1 == 1000000)
+			iap->ia_valid &= ~(ATTR_ATIME_SET|ATTR_MTIME_SET);
+	}
+	return p;
+}
+
+static __be32 *
+encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp,
+	     struct kstat *stat)
+{
+	struct dentry	*dentry = fhp->fh_dentry;
+	int type;
+	struct timespec64 time;
+	u32 f;
+
+	type = (stat->mode & S_IFMT);
+
+	*p++ = htonl(nfs_ftypes[type >> 12]);
+	*p++ = htonl((u32) stat->mode);
+	*p++ = htonl((u32) stat->nlink);
+	*p++ = htonl((u32) from_kuid(&init_user_ns, stat->uid));
+	*p++ = htonl((u32) from_kgid(&init_user_ns, stat->gid));
+
+	if (S_ISLNK(type) && stat->size > NFS_MAXPATHLEN) {
+		*p++ = htonl(NFS_MAXPATHLEN);
+	} else {
+		*p++ = htonl((u32) stat->size);
+	}
+	*p++ = htonl((u32) stat->blksize);
+	if (S_ISCHR(type) || S_ISBLK(type))
+		*p++ = htonl(new_encode_dev(stat->rdev));
+	else
+		*p++ = htonl(0xffffffff);
+	*p++ = htonl((u32) stat->blocks);
+	switch (fsid_source(fhp)) {
+	default:
+	case FSIDSOURCE_DEV:
+		*p++ = htonl(new_encode_dev(stat->dev));
+		break;
+	case FSIDSOURCE_FSID:
+		*p++ = htonl((u32) fhp->fh_export->ex_fsid);
+		break;
+	case FSIDSOURCE_UUID:
+		f = ((u32*)fhp->fh_export->ex_uuid)[0];
+		f ^= ((u32*)fhp->fh_export->ex_uuid)[1];
+		f ^= ((u32*)fhp->fh_export->ex_uuid)[2];
+		f ^= ((u32*)fhp->fh_export->ex_uuid)[3];
+		*p++ = htonl(f);
+		break;
+	}
+	*p++ = htonl((u32) stat->ino);
+	*p++ = htonl((u32) stat->atime.tv_sec);
+	*p++ = htonl(stat->atime.tv_nsec ? stat->atime.tv_nsec / 1000 : 0);
+	time = stat->mtime;
+	lease_get_mtime(d_inode(dentry), &time); 
+	*p++ = htonl((u32) time.tv_sec);
+	*p++ = htonl(time.tv_nsec ? time.tv_nsec / 1000 : 0); 
+	*p++ = htonl((u32) stat->ctime.tv_sec);
+	*p++ = htonl(stat->ctime.tv_nsec ? stat->ctime.tv_nsec / 1000 : 0);
+
+	return p;
+}
+
+/* Helper function for NFSv2 ACL code */
+__be32 *nfs2svc_encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp, struct kstat *stat)
+{
+	return encode_fattr(rqstp, p, fhp, stat);
+}
+
+/*
+ * XDR decode functions
+ */
+int
+nfssvc_decode_void(struct svc_rqst *rqstp, __be32 *p)
+{
+	return xdr_argsize_check(rqstp, p);
+}
+
+int
+nfssvc_decode_fhandle(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_fhandle *args = rqstp->rq_argp;
+
+	p = decode_fh(p, &args->fh);
+	if (!p)
+		return 0;
+	return xdr_argsize_check(rqstp, p);
+}
+
+int
+nfssvc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_sattrargs *args = rqstp->rq_argp;
+
+	p = decode_fh(p, &args->fh);
+	if (!p)
+		return 0;
+	p = decode_sattr(p, &args->attrs);
+
+	return xdr_argsize_check(rqstp, p);
+}
+
+int
+nfssvc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_diropargs *args = rqstp->rq_argp;
+
+	if (!(p = decode_fh(p, &args->fh))
+	 || !(p = decode_filename(p, &args->name, &args->len)))
+		return 0;
+
+	return xdr_argsize_check(rqstp, p);
+}
+
+int
+nfssvc_decode_readargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_readargs *args = rqstp->rq_argp;
+	unsigned int len;
+	int v;
+	p = decode_fh(p, &args->fh);
+	if (!p)
+		return 0;
+
+	args->offset    = ntohl(*p++);
+	len = args->count     = ntohl(*p++);
+	p++; /* totalcount - unused */
+
+	len = min_t(unsigned int, len, NFSSVC_MAXBLKSIZE_V2);
+
+	/* set up somewhere to store response.
+	 * We take pages, put them on reslist and include in iovec
+	 */
+	v=0;
+	while (len > 0) {
+		struct page *p = *(rqstp->rq_next_page++);
+
+		rqstp->rq_vec[v].iov_base = page_address(p);
+		rqstp->rq_vec[v].iov_len = min_t(unsigned int, len, PAGE_SIZE);
+		len -= rqstp->rq_vec[v].iov_len;
+		v++;
+	}
+	args->vlen = v;
+	return xdr_argsize_check(rqstp, p);
+}
+
+int
+nfssvc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_writeargs *args = rqstp->rq_argp;
+	unsigned int len, hdr, dlen;
+	struct kvec *head = rqstp->rq_arg.head;
+
+	p = decode_fh(p, &args->fh);
+	if (!p)
+		return 0;
+
+	p++;				/* beginoffset */
+	args->offset = ntohl(*p++);	/* offset */
+	p++;				/* totalcount */
+	len = args->len = ntohl(*p++);
+	/*
+	 * The protocol specifies a maximum of 8192 bytes.
+	 */
+	if (len > NFSSVC_MAXBLKSIZE_V2)
+		return 0;
+
+	/*
+	 * Check to make sure that we got the right number of
+	 * bytes.
+	 */
+	hdr = (void*)p - head->iov_base;
+	if (hdr > head->iov_len)
+		return 0;
+	dlen = head->iov_len + rqstp->rq_arg.page_len - hdr;
+
+	/*
+	 * Round the length of the data which was specified up to
+	 * the next multiple of XDR units and then compare that
+	 * against the length which was actually received.
+	 * Note that when RPCSEC/GSS (for example) is used, the
+	 * data buffer can be padded so dlen might be larger
+	 * than required.  It must never be smaller.
+	 */
+	if (dlen < XDR_QUADLEN(len)*4)
+		return 0;
+
+	args->first.iov_base = (void *)p;
+	args->first.iov_len = head->iov_len - hdr;
+	return 1;
+}
+
+int
+nfssvc_decode_createargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_createargs *args = rqstp->rq_argp;
+
+	if (   !(p = decode_fh(p, &args->fh))
+	    || !(p = decode_filename(p, &args->name, &args->len)))
+		return 0;
+	p = decode_sattr(p, &args->attrs);
+
+	return xdr_argsize_check(rqstp, p);
+}
+
+int
+nfssvc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_renameargs *args = rqstp->rq_argp;
+
+	if (!(p = decode_fh(p, &args->ffh))
+	 || !(p = decode_filename(p, &args->fname, &args->flen))
+	 || !(p = decode_fh(p, &args->tfh))
+	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
+		return 0;
+
+	return xdr_argsize_check(rqstp, p);
+}
+
+int
+nfssvc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_readlinkargs *args = rqstp->rq_argp;
+
+	p = decode_fh(p, &args->fh);
+	if (!p)
+		return 0;
+	args->buffer = page_address(*(rqstp->rq_next_page++));
+
+	return xdr_argsize_check(rqstp, p);
+}
+
+int
+nfssvc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_linkargs *args = rqstp->rq_argp;
+
+	if (!(p = decode_fh(p, &args->ffh))
+	 || !(p = decode_fh(p, &args->tfh))
+	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
+		return 0;
+
+	return xdr_argsize_check(rqstp, p);
+}
+
+int
+nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_symlinkargs *args = rqstp->rq_argp;
+	char *base = (char *)p;
+	size_t xdrlen;
+
+	if (   !(p = decode_fh(p, &args->ffh))
+	    || !(p = decode_filename(p, &args->fname, &args->flen)))
+		return 0;
+
+	args->tlen = ntohl(*p++);
+	if (args->tlen == 0)
+		return 0;
+
+	args->first.iov_base = p;
+	args->first.iov_len = rqstp->rq_arg.head[0].iov_len;
+	args->first.iov_len -= (char *)p - base;
+
+	/* This request is never larger than a page. Therefore,
+	 * transport will deliver either:
+	 * 1. pathname in the pagelist -> sattr is in the tail.
+	 * 2. everything in the head buffer -> sattr is in the head.
+	 */
+	if (rqstp->rq_arg.page_len) {
+		if (args->tlen != rqstp->rq_arg.page_len)
+			return 0;
+		p = rqstp->rq_arg.tail[0].iov_base;
+	} else {
+		xdrlen = XDR_QUADLEN(args->tlen);
+		if (xdrlen > args->first.iov_len - (8 * sizeof(__be32)))
+			return 0;
+		p += xdrlen;
+	}
+	decode_sattr(p, &args->attrs);
+
+	return 1;
+}
+
+int
+nfssvc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_readdirargs *args = rqstp->rq_argp;
+
+	p = decode_fh(p, &args->fh);
+	if (!p)
+		return 0;
+	args->cookie = ntohl(*p++);
+	args->count  = ntohl(*p++);
+	args->count  = min_t(u32, args->count, PAGE_SIZE);
+	args->buffer = page_address(*(rqstp->rq_next_page++));
+
+	return xdr_argsize_check(rqstp, p);
+}
+
+/*
+ * XDR encode functions
+ */
+int
+nfssvc_encode_void(struct svc_rqst *rqstp, __be32 *p)
+{
+	return xdr_ressize_check(rqstp, p);
+}
+
+int
+nfssvc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_attrstat *resp = rqstp->rq_resp;
+
+	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
+	return xdr_ressize_check(rqstp, p);
+}
+
+int
+nfssvc_encode_diropres(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_diropres *resp = rqstp->rq_resp;
+
+	p = encode_fh(p, &resp->fh);
+	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
+	return xdr_ressize_check(rqstp, p);
+}
+
+int
+nfssvc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_readlinkres *resp = rqstp->rq_resp;
+
+	*p++ = htonl(resp->len);
+	xdr_ressize_check(rqstp, p);
+	rqstp->rq_res.page_len = resp->len;
+	if (resp->len & 3) {
+		/* need to pad the tail */
+		rqstp->rq_res.tail[0].iov_base = p;
+		*p = 0;
+		rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
+	}
+	return 1;
+}
+
+int
+nfssvc_encode_readres(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_readres *resp = rqstp->rq_resp;
+
+	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
+	*p++ = htonl(resp->count);
+	xdr_ressize_check(rqstp, p);
+
+	/* now update rqstp->rq_res to reflect data as well */
+	rqstp->rq_res.page_len = resp->count;
+	if (resp->count & 3) {
+		/* need to pad the tail */
+		rqstp->rq_res.tail[0].iov_base = p;
+		*p = 0;
+		rqstp->rq_res.tail[0].iov_len = 4 - (resp->count&3);
+	}
+	return 1;
+}
+
+int
+nfssvc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_readdirres *resp = rqstp->rq_resp;
+
+	xdr_ressize_check(rqstp, p);
+	p = resp->buffer;
+	*p++ = 0;			/* no more entries */
+	*p++ = htonl((resp->common.err == nfserr_eof));
+	rqstp->rq_res.page_len = (((unsigned long)p-1) & ~PAGE_MASK)+1;
+
+	return 1;
+}
+
+int
+nfssvc_encode_statfsres(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_statfsres *resp = rqstp->rq_resp;
+	struct kstatfs	*stat = &resp->stats;
+
+	*p++ = htonl(NFSSVC_MAXBLKSIZE_V2);	/* max transfer size */
+	*p++ = htonl(stat->f_bsize);
+	*p++ = htonl(stat->f_blocks);
+	*p++ = htonl(stat->f_bfree);
+	*p++ = htonl(stat->f_bavail);
+	return xdr_ressize_check(rqstp, p);
+}
+
+int
+nfssvc_encode_entry(void *ccdv, const char *name,
+		    int namlen, loff_t offset, u64 ino, unsigned int d_type)
+{
+	struct readdir_cd *ccd = ccdv;
+	struct nfsd_readdirres *cd = container_of(ccd, struct nfsd_readdirres, common);
+	__be32	*p = cd->buffer;
+	int	buflen, slen;
+
+	/*
+	dprintk("nfsd: entry(%.*s off %ld ino %ld)\n",
+			namlen, name, offset, ino);
+	 */
+
+	if (offset > ~((u32) 0)) {
+		cd->common.err = nfserr_fbig;
+		return -EINVAL;
+	}
+	if (cd->offset)
+		*cd->offset = htonl(offset);
+
+	/* truncate filename */
+	namlen = min(namlen, NFS2_MAXNAMLEN);
+	slen = XDR_QUADLEN(namlen);
+
+	if ((buflen = cd->buflen - slen - 4) < 0) {
+		cd->common.err = nfserr_toosmall;
+		return -EINVAL;
+	}
+	if (ino > ~((u32) 0)) {
+		cd->common.err = nfserr_fbig;
+		return -EINVAL;
+	}
+	*p++ = xdr_one;				/* mark entry present */
+	*p++ = htonl((u32) ino);		/* file id */
+	p    = xdr_encode_array(p, name, namlen);/* name length & name */
+	cd->offset = p;			/* remember pointer */
+	*p++ = htonl(~0U);		/* offset of next entry */
+
+	cd->buflen = buflen;
+	cd->buffer = p;
+	cd->common.err = nfs_ok;
+	return 0;
+}
+
+/*
+ * XDR release functions
+ */
+void
+nfssvc_release_fhandle(struct svc_rqst *rqstp)
+{
+	struct nfsd_fhandle *resp = rqstp->rq_resp;
+
+	fh_put(&resp->fh);
+}