xref: /linux-6.15/include/linux/sunrpc/xdr.h (revision c9d05cfc)
1 /*
2  * include/linux/sunrpc/xdr.h
3  *
4  * Copyright (C) 1995-1997 Olaf Kirch <[email protected]>
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 #include <linux/scatterlist.h>
15 
16 /*
17  * Buffer adjustment
18  */
19 #define XDR_QUADLEN(l)		(((l) + 3) >> 2)
20 
21 /*
22  * Generic opaque `network object.' At the kernel level, this type
23  * is used only by lockd.
24  */
25 #define XDR_MAX_NETOBJ		1024
26 struct xdr_netobj {
27 	unsigned int		len;
28 	u8 *			data;
29 };
30 
31 /*
32  * This is the generic XDR function. rqstp is either a rpc_rqst (client
33  * side) or svc_rqst pointer (server side).
34  * Encode functions always assume there's enough room in the buffer.
35  */
36 typedef int	(*kxdrproc_t)(void *rqstp, __be32 *data, void *obj);
37 
38 /*
39  * Basic structure for transmission/reception of a client XDR message.
40  * Features a header (for a linear buffer containing RPC headers
41  * and the data payload for short messages), and then an array of
42  * pages.
43  * The tail iovec allows you to append data after the page array. Its
44  * main interest is for appending padding to the pages in order to
45  * satisfy the int_32-alignment requirements in RFC1832.
46  *
47  * For the future, we might want to string several of these together
48  * in a list if anybody wants to make use of NFSv4 COMPOUND
49  * operations and/or has a need for scatter/gather involving pages.
50  */
51 struct xdr_buf {
52 	struct kvec	head[1],	/* RPC header + non-page data */
53 			tail[1];	/* Appended after page data */
54 
55 	struct page **	pages;		/* Array of contiguous pages */
56 	unsigned int	page_base,	/* Start of page data */
57 			page_len,	/* Length of page data */
58 			flags;		/* Flags for data disposition */
59 #define XDRBUF_READ		0x01		/* target of file read */
60 #define XDRBUF_WRITE		0x02		/* source of file write */
61 
62 	unsigned int	buflen,		/* Total length of storage buffer */
63 			len;		/* Length of XDR encoded message */
64 
65 };
66 
67 /*
68  * pre-xdr'ed macros.
69  */
70 
71 #define	xdr_zero	cpu_to_be32(0)
72 #define	xdr_one		cpu_to_be32(1)
73 #define	xdr_two		cpu_to_be32(2)
74 
75 #define	rpc_success		cpu_to_be32(RPC_SUCCESS)
76 #define	rpc_prog_unavail	cpu_to_be32(RPC_PROG_UNAVAIL)
77 #define	rpc_prog_mismatch	cpu_to_be32(RPC_PROG_MISMATCH)
78 #define	rpc_proc_unavail	cpu_to_be32(RPC_PROC_UNAVAIL)
79 #define	rpc_garbage_args	cpu_to_be32(RPC_GARBAGE_ARGS)
80 #define	rpc_system_err		cpu_to_be32(RPC_SYSTEM_ERR)
81 #define	rpc_drop_reply		cpu_to_be32(RPC_DROP_REPLY)
82 
83 #define	rpc_auth_ok		cpu_to_be32(RPC_AUTH_OK)
84 #define	rpc_autherr_badcred	cpu_to_be32(RPC_AUTH_BADCRED)
85 #define	rpc_autherr_rejectedcred cpu_to_be32(RPC_AUTH_REJECTEDCRED)
86 #define	rpc_autherr_badverf	cpu_to_be32(RPC_AUTH_BADVERF)
87 #define	rpc_autherr_rejectedverf cpu_to_be32(RPC_AUTH_REJECTEDVERF)
88 #define	rpc_autherr_tooweak	cpu_to_be32(RPC_AUTH_TOOWEAK)
89 #define	rpcsec_gsserr_credproblem	cpu_to_be32(RPCSEC_GSS_CREDPROBLEM)
90 #define	rpcsec_gsserr_ctxproblem	cpu_to_be32(RPCSEC_GSS_CTXPROBLEM)
91 #define	rpc_autherr_oldseqnum	cpu_to_be32(101)
92 
93 /*
94  * Miscellaneous XDR helper functions
95  */
96 __be32 *xdr_encode_opaque_fixed(__be32 *p, const void *ptr, unsigned int len);
97 __be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int len);
98 __be32 *xdr_encode_string(__be32 *p, const char *s);
99 __be32 *xdr_decode_string_inplace(__be32 *p, char **sp, unsigned int *lenp,
100 			unsigned int maxlen);
101 __be32 *xdr_encode_netobj(__be32 *p, const struct xdr_netobj *);
102 __be32 *xdr_decode_netobj(__be32 *p, struct xdr_netobj *);
103 
104 void	xdr_encode_pages(struct xdr_buf *, struct page **, unsigned int,
105 			 unsigned int);
106 void	xdr_inline_pages(struct xdr_buf *, unsigned int,
107 			 struct page **, unsigned int, unsigned int);
108 
109 static inline __be32 *xdr_encode_array(__be32 *p, const void *s, unsigned int len)
110 {
111 	return xdr_encode_opaque(p, s, len);
112 }
113 
114 /*
115  * Decode 64bit quantities (NFSv3 support)
116  */
117 static inline __be32 *
118 xdr_encode_hyper(__be32 *p, __u64 val)
119 {
120 	*(__be64 *)p = cpu_to_be64(val);
121 	return p + 2;
122 }
123 
124 static inline __be32 *
125 xdr_decode_hyper(__be32 *p, __u64 *valp)
126 {
127 	*valp = be64_to_cpup((__be64 *)p);
128 	return p + 2;
129 }
130 
131 /*
132  * Adjust kvec to reflect end of xdr'ed data (RPC client XDR)
133  */
134 static inline int
135 xdr_adjust_iovec(struct kvec *iov, __be32 *p)
136 {
137 	return iov->iov_len = ((u8 *) p - (u8 *) iov->iov_base);
138 }
139 
140 /*
141  * XDR buffer helper functions
142  */
143 extern void xdr_shift_buf(struct xdr_buf *, size_t);
144 extern void xdr_buf_from_iov(struct kvec *, struct xdr_buf *);
145 extern int xdr_buf_subsegment(struct xdr_buf *, struct xdr_buf *, unsigned int, unsigned int);
146 extern int xdr_buf_read_netobj(struct xdr_buf *, struct xdr_netobj *, unsigned int);
147 extern int read_bytes_from_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int);
148 extern int write_bytes_to_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int);
149 
150 /*
151  * Helper structure for copying from an sk_buff.
152  */
153 struct xdr_skb_reader {
154 	struct sk_buff	*skb;
155 	unsigned int	offset;
156 	size_t		count;
157 	__wsum		csum;
158 };
159 
160 typedef size_t (*xdr_skb_read_actor)(struct xdr_skb_reader *desc, void *to, size_t len);
161 
162 size_t xdr_skb_read_bits(struct xdr_skb_reader *desc, void *to, size_t len);
163 extern int csum_partial_copy_to_xdr(struct xdr_buf *, struct sk_buff *);
164 extern ssize_t xdr_partial_copy_from_skb(struct xdr_buf *, unsigned int,
165 		struct xdr_skb_reader *, xdr_skb_read_actor);
166 
167 extern int xdr_encode_word(struct xdr_buf *, unsigned int, u32);
168 extern int xdr_decode_word(struct xdr_buf *, unsigned int, u32 *);
169 
170 struct xdr_array2_desc;
171 typedef int (*xdr_xcode_elem_t)(struct xdr_array2_desc *desc, void *elem);
172 struct xdr_array2_desc {
173 	unsigned int elem_size;
174 	unsigned int array_len;
175 	unsigned int array_maxlen;
176 	xdr_xcode_elem_t xcode;
177 };
178 
179 extern int xdr_decode_array2(struct xdr_buf *buf, unsigned int base,
180                              struct xdr_array2_desc *desc);
181 extern int xdr_encode_array2(struct xdr_buf *buf, unsigned int base,
182 			     struct xdr_array2_desc *desc);
183 
184 /*
185  * Provide some simple tools for XDR buffer overflow-checking etc.
186  */
187 struct xdr_stream {
188 	__be32 *p;		/* start of available buffer */
189 	struct xdr_buf *buf;	/* XDR buffer to read/write */
190 
191 	__be32 *end;		/* end of available buffer space */
192 	struct kvec *iov;	/* pointer to the current kvec */
193 };
194 
195 extern void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p);
196 extern __be32 *xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes);
197 extern void xdr_write_pages(struct xdr_stream *xdr, struct page **pages,
198 		unsigned int base, unsigned int len);
199 extern void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p);
200 extern __be32 *xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes);
201 extern void xdr_read_pages(struct xdr_stream *xdr, unsigned int len);
202 extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len);
203 extern int xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data);
204 
205 #endif /* __KERNEL__ */
206 
207 #endif /* _SUNRPC_XDR_H_ */
208