1/*
2 * include/linux/sunrpc/xdr.h
3 *
4 * Copyright (C) 1995-1997 Olaf Kirch <okir@monad.swb.de>
5 */
6
7#ifndef _SUNRPC_XDR_H_
8#define _SUNRPC_XDR_H_
9
10#ifdef __KERNEL__
11
12#include <linux/uio.h>
13#include <asm/byteorder.h>
14
15/*
16 * Buffer adjustment
17 */
18#define XDR_QUADLEN(l)		(((l) + 3) >> 2)
19
20/*
21 * Generic opaque `network object.' At the kernel level, this type
22 * is used only by lockd.
23 */
24#define XDR_MAX_NETOBJ		1024
25struct xdr_netobj {
26	unsigned int		len;
27	u8 *			data;
28};
29
30/*
31 * This is the generic XDR function. rqstp is either a rpc_rqst (client
32 * side) or svc_rqst pointer (server side).
33 * Encode functions always assume there's enough room in the buffer.
34 */
35typedef int	(*kxdrproc_t)(void *rqstp, u32 *data, void *obj);
36
37/*
38 * Basic structure for transmission/reception of a client XDR message.
39 * Features a header (for a linear buffer containing RPC headers
40 * and the data payload for short messages), and then an array of
41 * pages.
42 * The tail iovec allows you to append data after the page array. Its
43 * main interest is for appending padding to the pages in order to
44 * satisfy the int_32-alignment requirements in RFC1832.
45 *
46 * For the future, we might want to string several of these together
47 * in a list if anybody wants to make use of NFSv4 COMPOUND
48 * operations and/or has a need for scatter/gather involving pages.
49 */
50struct xdr_buf {
51	struct kvec	head[1],	/* RPC header + non-page data */
52			tail[1];	/* Appended after page data */
53
54	struct page **	pages;		/* Array of contiguous pages */
55	unsigned int	page_base,	/* Start of page data */
56			page_len;	/* Length of page data */
57
58	unsigned int	buflen,		/* Total length of storage buffer */
59			len;		/* Length of XDR encoded message */
60
61};
62
63/*
64 * pre-xdr'ed macros.
65 */
66
67#define	xdr_zero	__constant_htonl(0)
68#define	xdr_one		__constant_htonl(1)
69#define	xdr_two		__constant_htonl(2)
70
71#define	rpc_success		__constant_htonl(RPC_SUCCESS)
72#define	rpc_prog_unavail	__constant_htonl(RPC_PROG_UNAVAIL)
73#define	rpc_prog_mismatch	__constant_htonl(RPC_PROG_MISMATCH)
74#define	rpc_proc_unavail	__constant_htonl(RPC_PROC_UNAVAIL)
75#define	rpc_garbage_args	__constant_htonl(RPC_GARBAGE_ARGS)
76#define	rpc_system_err		__constant_htonl(RPC_SYSTEM_ERR)
77
78#define	rpc_auth_ok		__constant_htonl(RPC_AUTH_OK)
79#define	rpc_autherr_badcred	__constant_htonl(RPC_AUTH_BADCRED)
80#define	rpc_autherr_rejectedcred __constant_htonl(RPC_AUTH_REJECTEDCRED)
81#define	rpc_autherr_badverf	__constant_htonl(RPC_AUTH_BADVERF)
82#define	rpc_autherr_rejectedverf __constant_htonl(RPC_AUTH_REJECTEDVERF)
83#define	rpc_autherr_tooweak	__constant_htonl(RPC_AUTH_TOOWEAK)
84#define	rpcsec_gsserr_credproblem	__constant_htonl(RPCSEC_GSS_CREDPROBLEM)
85#define	rpcsec_gsserr_ctxproblem	__constant_htonl(RPCSEC_GSS_CTXPROBLEM)
86#define	rpc_autherr_oldseqnum	__constant_htonl(101)
87
88/*
89 * Miscellaneous XDR helper functions
90 */
91u32 *	xdr_encode_opaque_fixed(u32 *p, const void *ptr, unsigned int len);
92u32 *	xdr_encode_opaque(u32 *p, const void *ptr, unsigned int len);
93u32 *	xdr_encode_string(u32 *p, const char *s);
94u32 *	xdr_decode_string_inplace(u32 *p, char **sp, int *lenp, int maxlen);
95u32 *	xdr_encode_netobj(u32 *p, const struct xdr_netobj *);
96u32 *	xdr_decode_netobj(u32 *p, struct xdr_netobj *);
97
98void	xdr_encode_pages(struct xdr_buf *, struct page **, unsigned int,
99			 unsigned int);
100void	xdr_inline_pages(struct xdr_buf *, unsigned int,
101			 struct page **, unsigned int, unsigned int);
102
103static inline u32 *xdr_encode_array(u32 *p, const void *s, unsigned int len)
104{
105	return xdr_encode_opaque(p, s, len);
106}
107
108/*
109 * Decode 64bit quantities (NFSv3 support)
110 */
111static inline u32 *
112xdr_encode_hyper(u32 *p, __u64 val)
113{
114	*p++ = htonl(val >> 32);
115	*p++ = htonl(val & 0xFFFFFFFF);
116	return p;
117}
118
119static inline u32 *
120xdr_decode_hyper(u32 *p, __u64 *valp)
121{
122	*valp  = ((__u64) ntohl(*p++)) << 32;
123	*valp |= ntohl(*p++);
124	return p;
125}
126
127/*
128 * Adjust kvec to reflect end of xdr'ed data (RPC client XDR)
129 */
130static inline int
131xdr_adjust_iovec(struct kvec *iov, u32 *p)
132{
133	return iov->iov_len = ((u8 *) p - (u8 *) iov->iov_base);
134}
135
136/*
137 * XDR buffer helper functions
138 */
139extern void xdr_shift_buf(struct xdr_buf *, size_t);
140extern void xdr_buf_from_iov(struct kvec *, struct xdr_buf *);
141extern int xdr_buf_subsegment(struct xdr_buf *, struct xdr_buf *, int, int);
142extern int xdr_buf_read_netobj(struct xdr_buf *, struct xdr_netobj *, int);
143extern int read_bytes_from_xdr_buf(struct xdr_buf *, int, void *, int);
144extern int write_bytes_to_xdr_buf(struct xdr_buf *, int, void *, int);
145
146/*
147 * Helper structure for copying from an sk_buff.
148 */
149typedef struct {
150	struct sk_buff	*skb;
151	unsigned int	offset;
152	size_t		count;
153	unsigned int	csum;
154} skb_reader_t;
155
156typedef size_t (*skb_read_actor_t)(skb_reader_t *desc, void *to, size_t len);
157
158extern int csum_partial_copy_to_xdr(struct xdr_buf *, struct sk_buff *);
159extern ssize_t xdr_partial_copy_from_skb(struct xdr_buf *, unsigned int,
160		skb_reader_t *, skb_read_actor_t);
161
162extern int xdr_encode_word(struct xdr_buf *, int, u32);
163extern int xdr_decode_word(struct xdr_buf *, int, u32 *);
164
165struct xdr_array2_desc;
166typedef int (*xdr_xcode_elem_t)(struct xdr_array2_desc *desc, void *elem);
167struct xdr_array2_desc {
168	unsigned int elem_size;
169	unsigned int array_len;
170	unsigned int array_maxlen;
171	xdr_xcode_elem_t xcode;
172};
173
174extern int xdr_decode_array2(struct xdr_buf *buf, unsigned int base,
175                             struct xdr_array2_desc *desc);
176extern int xdr_encode_array2(struct xdr_buf *buf, unsigned int base,
177			     struct xdr_array2_desc *desc);
178
179/*
180 * Provide some simple tools for XDR buffer overflow-checking etc.
181 */
182struct xdr_stream {
183	uint32_t *p;		/* start of available buffer */
184	struct xdr_buf *buf;	/* XDR buffer to read/write */
185
186	uint32_t *end;		/* end of available buffer space */
187	struct kvec *iov;	/* pointer to the current kvec */
188};
189
190extern void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, uint32_t *p);
191extern uint32_t *xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes);
192extern void xdr_write_pages(struct xdr_stream *xdr, struct page **pages,
193		unsigned int base, unsigned int len);
194extern void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, uint32_t *p);
195extern uint32_t *xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes);
196extern void xdr_read_pages(struct xdr_stream *xdr, unsigned int len);
197extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len);
198
199#endif /* __KERNEL__ */
200
201#endif /* _SUNRPC_XDR_H_ */
202