1/*
2 * XDR standard data types and function declarations
3 *
4 * Copyright (C) 1995-1997 Olaf Kirch <okir@monad.swb.de>
5 *
6 * Based on:
7 *   RFC 4506 "XDR: External Data Representation Standard", May 2006
8 */
9
10#ifndef _SUNRPC_XDR_H_
11#define _SUNRPC_XDR_H_
12
13#ifdef __KERNEL__
14
15#include <linux/uio.h>
16#include <asm/byteorder.h>
17#include <asm/unaligned.h>
18#include <linux/scatterlist.h>
19
20/*
21 * Buffer adjustment
22 */
23#define XDR_QUADLEN(l)		(((l) + 3) >> 2)
24
25/*
26 * Generic opaque `network object.' At the kernel level, this type
27 * is used only by lockd.
28 */
29#define XDR_MAX_NETOBJ		1024
30struct xdr_netobj {
31	unsigned int		len;
32	u8 *			data;
33};
34
35/*
36 * This is the legacy generic XDR function. rqstp is either a rpc_rqst
37 * (client side) or svc_rqst pointer (server side).
38 * Encode functions always assume there's enough room in the buffer.
39 */
40typedef int	(*kxdrproc_t)(void *rqstp, __be32 *data, void *obj);
41
42/*
43 * Basic structure for transmission/reception of a client XDR message.
44 * Features a header (for a linear buffer containing RPC headers
45 * and the data payload for short messages), and then an array of
46 * pages.
47 * The tail iovec allows you to append data after the page array. Its
48 * main interest is for appending padding to the pages in order to
49 * satisfy the int_32-alignment requirements in RFC1832.
50 *
51 * For the future, we might want to string several of these together
52 * in a list if anybody wants to make use of NFSv4 COMPOUND
53 * operations and/or has a need for scatter/gather involving pages.
54 */
55struct xdr_buf {
56	struct kvec	head[1],	/* RPC header + non-page data */
57			tail[1];	/* Appended after page data */
58
59	struct page **	pages;		/* Array of pages */
60	unsigned int	page_base,	/* Start of page data */
61			page_len,	/* Length of page data */
62			flags;		/* Flags for data disposition */
63#define XDRBUF_READ		0x01		/* target of file read */
64#define XDRBUF_WRITE		0x02		/* source of file write */
65
66	unsigned int	buflen,		/* Total length of storage buffer */
67			len;		/* Length of XDR encoded message */
68};
69
70/*
71 * pre-xdr'ed macros.
72 */
73
74#define	xdr_zero	cpu_to_be32(0)
75#define	xdr_one		cpu_to_be32(1)
76#define	xdr_two		cpu_to_be32(2)
77
78#define	rpc_success		cpu_to_be32(RPC_SUCCESS)
79#define	rpc_prog_unavail	cpu_to_be32(RPC_PROG_UNAVAIL)
80#define	rpc_prog_mismatch	cpu_to_be32(RPC_PROG_MISMATCH)
81#define	rpc_proc_unavail	cpu_to_be32(RPC_PROC_UNAVAIL)
82#define	rpc_garbage_args	cpu_to_be32(RPC_GARBAGE_ARGS)
83#define	rpc_system_err		cpu_to_be32(RPC_SYSTEM_ERR)
84#define	rpc_drop_reply		cpu_to_be32(RPC_DROP_REPLY)
85
86#define	rpc_auth_ok		cpu_to_be32(RPC_AUTH_OK)
87#define	rpc_autherr_badcred	cpu_to_be32(RPC_AUTH_BADCRED)
88#define	rpc_autherr_rejectedcred cpu_to_be32(RPC_AUTH_REJECTEDCRED)
89#define	rpc_autherr_badverf	cpu_to_be32(RPC_AUTH_BADVERF)
90#define	rpc_autherr_rejectedverf cpu_to_be32(RPC_AUTH_REJECTEDVERF)
91#define	rpc_autherr_tooweak	cpu_to_be32(RPC_AUTH_TOOWEAK)
92#define	rpcsec_gsserr_credproblem	cpu_to_be32(RPCSEC_GSS_CREDPROBLEM)
93#define	rpcsec_gsserr_ctxproblem	cpu_to_be32(RPCSEC_GSS_CTXPROBLEM)
94#define	rpc_autherr_oldseqnum	cpu_to_be32(101)
95
96/*
97 * Miscellaneous XDR helper functions
98 */
99__be32 *xdr_encode_opaque_fixed(__be32 *p, const void *ptr, unsigned int len);
100__be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int len);
101__be32 *xdr_encode_string(__be32 *p, const char *s);
102__be32 *xdr_decode_string_inplace(__be32 *p, char **sp, unsigned int *lenp,
103			unsigned int maxlen);
104__be32 *xdr_encode_netobj(__be32 *p, const struct xdr_netobj *);
105__be32 *xdr_decode_netobj(__be32 *p, struct xdr_netobj *);
106
107void	xdr_inline_pages(struct xdr_buf *, unsigned int,
108			 struct page **, unsigned int, unsigned int);
109void	xdr_terminate_string(struct xdr_buf *, const u32);
110
111static inline __be32 *xdr_encode_array(__be32 *p, const void *s, unsigned int len)
112{
113	return xdr_encode_opaque(p, s, len);
114}
115
116/*
117 * Decode 64bit quantities (NFSv3 support)
118 */
119static inline __be32 *
120xdr_encode_hyper(__be32 *p, __u64 val)
121{
122	put_unaligned_be64(val, p);
123	return p + 2;
124}
125
126static inline __be32 *
127xdr_decode_hyper(__be32 *p, __u64 *valp)
128{
129	*valp = get_unaligned_be64(p);
130	return p + 2;
131}
132
133static inline __be32 *
134xdr_decode_opaque_fixed(__be32 *p, void *ptr, unsigned int len)
135{
136	memcpy(ptr, p, len);
137	return p + XDR_QUADLEN(len);
138}
139
140/*
141 * Adjust kvec to reflect end of xdr'ed data (RPC client XDR)
142 */
143static inline int
144xdr_adjust_iovec(struct kvec *iov, __be32 *p)
145{
146	return iov->iov_len = ((u8 *) p - (u8 *) iov->iov_base);
147}
148
149/*
150 * XDR buffer helper functions
151 */
152extern void xdr_shift_buf(struct xdr_buf *, size_t);
153extern void xdr_buf_from_iov(struct kvec *, struct xdr_buf *);
154extern int xdr_buf_subsegment(struct xdr_buf *, struct xdr_buf *, unsigned int, unsigned int);
155extern void xdr_buf_trim(struct xdr_buf *, unsigned int);
156extern int xdr_buf_read_netobj(struct xdr_buf *, struct xdr_netobj *, unsigned int);
157extern int read_bytes_from_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int);
158extern int write_bytes_to_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int);
159
160/*
161 * Helper structure for copying from an sk_buff.
162 */
163struct xdr_skb_reader {
164	struct sk_buff	*skb;
165	unsigned int	offset;
166	size_t		count;
167	__wsum		csum;
168};
169
170typedef size_t (*xdr_skb_read_actor)(struct xdr_skb_reader *desc, void *to, size_t len);
171
172size_t xdr_skb_read_bits(struct xdr_skb_reader *desc, void *to, size_t len);
173extern int csum_partial_copy_to_xdr(struct xdr_buf *, struct sk_buff *);
174extern ssize_t xdr_partial_copy_from_skb(struct xdr_buf *, unsigned int,
175		struct xdr_skb_reader *, xdr_skb_read_actor);
176
177extern int xdr_encode_word(struct xdr_buf *, unsigned int, u32);
178extern int xdr_decode_word(struct xdr_buf *, unsigned int, u32 *);
179
180struct xdr_array2_desc;
181typedef int (*xdr_xcode_elem_t)(struct xdr_array2_desc *desc, void *elem);
182struct xdr_array2_desc {
183	unsigned int elem_size;
184	unsigned int array_len;
185	unsigned int array_maxlen;
186	xdr_xcode_elem_t xcode;
187};
188
189extern int xdr_decode_array2(struct xdr_buf *buf, unsigned int base,
190			     struct xdr_array2_desc *desc);
191extern int xdr_encode_array2(struct xdr_buf *buf, unsigned int base,
192			     struct xdr_array2_desc *desc);
193extern void _copy_from_pages(char *p, struct page **pages, size_t pgbase,
194			     size_t len);
195
196/*
197 * Provide some simple tools for XDR buffer overflow-checking etc.
198 */
199struct xdr_stream {
200	__be32 *p;		/* start of available buffer */
201	struct xdr_buf *buf;	/* XDR buffer to read/write */
202
203	__be32 *end;		/* end of available buffer space */
204	struct kvec *iov;	/* pointer to the current kvec */
205	struct kvec scratch;	/* Scratch buffer */
206	struct page **page_ptr;	/* pointer to the current page */
207	unsigned int nwords;	/* Remaining decode buffer length */
208};
209
210/*
211 * These are the xdr_stream style generic XDR encode and decode functions.
212 */
213typedef void	(*kxdreproc_t)(void *rqstp, struct xdr_stream *xdr, void *obj);
214typedef int	(*kxdrdproc_t)(void *rqstp, struct xdr_stream *xdr, void *obj);
215
216extern void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p);
217extern __be32 *xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes);
218extern void xdr_commit_encode(struct xdr_stream *xdr);
219extern void xdr_truncate_encode(struct xdr_stream *xdr, size_t len);
220extern int xdr_restrict_buflen(struct xdr_stream *xdr, int newbuflen);
221extern void xdr_write_pages(struct xdr_stream *xdr, struct page **pages,
222		unsigned int base, unsigned int len);
223extern unsigned int xdr_stream_pos(const struct xdr_stream *xdr);
224extern void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p);
225extern void xdr_init_decode_pages(struct xdr_stream *xdr, struct xdr_buf *buf,
226		struct page **pages, unsigned int len);
227extern void xdr_set_scratch_buffer(struct xdr_stream *xdr, void *buf, size_t buflen);
228extern __be32 *xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes);
229extern unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len);
230extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len);
231extern int xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data);
232
233#endif /* __KERNEL__ */
234
235#endif /* _SUNRPC_XDR_H_ */
236