diff options
| -rw-r--r-- | fs/nfs_common/nfsacl.c | 52 | ||||
| -rw-r--r-- | include/linux/nfsacl.h | 3 |
2 files changed, 55 insertions, 0 deletions
diff --git a/fs/nfs_common/nfsacl.c b/fs/nfs_common/nfsacl.c index d056ad2fdefd..79c563c1a5e8 100644 --- a/fs/nfs_common/nfsacl.c +++ b/fs/nfs_common/nfsacl.c @@ -295,3 +295,55 @@ int nfsacl_decode(struct xdr_buf *buf, unsigned int base, unsigned int *aclcnt, nfsacl_desc.desc.array_len; } EXPORT_SYMBOL_GPL(nfsacl_decode); + +/** + * nfs_stream_decode_acl - Decode an NFSv3 ACL + * + * @xdr: an xdr_stream positioned at an encoded ACL + * @aclcnt: OUT: count of ACEs in decoded posix_acl + * @pacl: OUT: a dynamically-allocated buffer containing the decoded posix_acl + * + * Return values: + * %false: The encoded ACL is not valid + * %true: @pacl contains a decoded ACL, and @xdr is advanced + * + * On a successful return, caller must release *pacl using posix_acl_release(). + */ +bool nfs_stream_decode_acl(struct xdr_stream *xdr, unsigned int *aclcnt, + struct posix_acl **pacl) +{ + const size_t elem_size = XDR_UNIT * 3; + struct nfsacl_decode_desc nfsacl_desc = { + .desc = { + .elem_size = elem_size, + .xcode = pacl ? xdr_nfsace_decode : NULL, + }, + }; + unsigned int base; + u32 entries; + + if (xdr_stream_decode_u32(xdr, &entries) < 0) + return false; + if (entries > NFS_ACL_MAX_ENTRIES) + return false; + + base = xdr_stream_pos(xdr); + if (!xdr_inline_decode(xdr, XDR_UNIT + elem_size * entries)) + return false; + nfsacl_desc.desc.array_maxlen = entries; + if (xdr_decode_array2(xdr->buf, base, &nfsacl_desc.desc)) + return false; + + if (pacl) { + if (entries != nfsacl_desc.desc.array_len || + posix_acl_from_nfsacl(nfsacl_desc.acl) != 0) { + posix_acl_release(nfsacl_desc.acl); + return false; + } + *pacl = nfsacl_desc.acl; + } + if (aclcnt) + *aclcnt = entries; + return true; +} +EXPORT_SYMBOL_GPL(nfs_stream_decode_acl); diff --git a/include/linux/nfsacl.h b/include/linux/nfsacl.h index 103d44695323..0ba99c513649 100644 --- a/include/linux/nfsacl.h +++ b/include/linux/nfsacl.h @@ -38,5 +38,8 @@ nfsacl_encode(struct xdr_buf *buf, unsigned int base, struct inode *inode, extern int nfsacl_decode(struct xdr_buf *buf, unsigned int base, unsigned int *aclcnt, struct posix_acl **pacl); +extern bool +nfs_stream_decode_acl(struct xdr_stream *xdr, unsigned int *aclcnt, + struct posix_acl **pacl); #endif /* __LINUX_NFSACL_H */ |