1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Encode/decode NLM basic data types 4 * 5 * Basic NLMv3 XDR data types are not defined in an IETF standards 6 * document. X/Open has a description of these data types that 7 * is useful. See Chapter 10 of "Protocols for Interworking: 8 * XNFS, Version 3W". 9 * 10 * Basic NLMv4 XDR data types are defined in Appendix II.1.4 of 11 * RFC 1813: "NFS Version 3 Protocol Specification". 12 * 13 * Author: Chuck Lever <chuck.lever@oracle.com> 14 * 15 * Copyright (c) 2020, Oracle and/or its affiliates. 16 */ 17 18 #ifndef _LOCKD_SVCXDR_H_ 19 #define _LOCKD_SVCXDR_H_ 20 21 static inline bool 22 svcxdr_decode_stats(struct xdr_stream *xdr, __be32 *status) 23 { 24 __be32 *p; 25 26 p = xdr_inline_decode(xdr, XDR_UNIT); 27 if (!p) 28 return false; 29 *status = *p; 30 31 return true; 32 } 33 34 static inline bool 35 svcxdr_encode_stats(struct xdr_stream *xdr, __be32 status) 36 { 37 __be32 *p; 38 39 p = xdr_reserve_space(xdr, XDR_UNIT); 40 if (!p) 41 return false; 42 *p = status; 43 44 return true; 45 } 46 47 static inline bool 48 svcxdr_decode_string(struct xdr_stream *xdr, char **data, unsigned int *data_len) 49 { 50 __be32 *p; 51 u32 len; 52 53 if (xdr_stream_decode_u32(xdr, &len) < 0) 54 return false; 55 if (len > NLM_MAXSTRLEN) 56 return false; 57 p = xdr_inline_decode(xdr, len); 58 if (!p) 59 return false; 60 *data_len = len; 61 *data = (char *)p; 62 63 return true; 64 } 65 66 /* 67 * NLM cookies are defined by specification to be a variable-length 68 * XDR opaque no longer than 1024 bytes. However, this implementation 69 * limits their length to 32 bytes, and treats zero-length cookies 70 * specially. 71 */ 72 static inline bool 73 svcxdr_decode_cookie(struct xdr_stream *xdr, struct nlm_cookie *cookie) 74 { 75 __be32 *p; 76 u32 len; 77 78 if (xdr_stream_decode_u32(xdr, &len) < 0) 79 return false; 80 if (len > NLM_MAXCOOKIELEN) 81 return false; 82 if (!len) 83 goto out_hpux; 84 85 p = xdr_inline_decode(xdr, len); 86 if (!p) 87 return false; 88 cookie->len = len; 89 memcpy(cookie->data, p, len); 90 91 return true; 92 93 /* apparently HPUX can return empty cookies */ 94 out_hpux: 95 cookie->len = 4; 96 memset(cookie->data, 0, 4); 97 return true; 98 } 99 100 static inline bool 101 svcxdr_encode_cookie(struct xdr_stream *xdr, const struct nlm_cookie *cookie) 102 { 103 __be32 *p; 104 105 if (xdr_stream_encode_u32(xdr, cookie->len) < 0) 106 return false; 107 p = xdr_reserve_space(xdr, cookie->len); 108 if (!p) 109 return false; 110 memcpy(p, cookie->data, cookie->len); 111 112 return true; 113 } 114 115 static inline bool 116 svcxdr_decode_owner(struct xdr_stream *xdr, struct xdr_netobj *obj) 117 { 118 __be32 *p; 119 u32 len; 120 121 if (xdr_stream_decode_u32(xdr, &len) < 0) 122 return false; 123 if (len > XDR_MAX_NETOBJ) 124 return false; 125 p = xdr_inline_decode(xdr, len); 126 if (!p) 127 return false; 128 obj->len = len; 129 obj->data = (u8 *)p; 130 131 return true; 132 } 133 134 static inline bool 135 svcxdr_encode_owner(struct xdr_stream *xdr, const struct xdr_netobj *obj) 136 { 137 if (obj->len > XDR_MAX_NETOBJ) 138 return false; 139 return xdr_stream_encode_opaque(xdr, obj->data, obj->len) > 0; 140 } 141 142 #endif /* _LOCKD_SVCXDR_H_ */ 143