xref: /linux-6.15/include/linux/sunrpc/xdr.h (revision 643d1f7f)
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 #include <linux/smp_lock.h>
16 
17 /*
18  * Buffer adjustment
19  */
20 #define XDR_QUADLEN(l)		(((l) + 3) >> 2)
21 
22 /*
23  * Generic opaque `network object.' At the kernel level, this type
24  * is used only by lockd.
25  */
26 #define XDR_MAX_NETOBJ		1024
27 struct xdr_netobj {
28 	unsigned int		len;
29 	u8 *			data;
30 };
31 
32 /*
33  * This is the generic XDR function. rqstp is either a rpc_rqst (client
34  * side) or svc_rqst pointer (server side).
35  * Encode functions always assume there's enough room in the buffer.
36  */
37 typedef int	(*kxdrproc_t)(void *rqstp, __be32 *data, void *obj);
38 
39 /*
40  * We're still requiring the BKL in the xdr code until it's been
41  * more carefully audited, at which point this wrapper will become
42  * unnecessary.
43  */
44 static inline int rpc_call_xdrproc(kxdrproc_t xdrproc, void *rqstp, __be32 *data, void *obj)
45 {
46 	int ret;
47 
48 	lock_kernel();
49 	ret = xdrproc(rqstp, data, obj);
50 	unlock_kernel();
51 	return ret;
52 }
53 
54 /*
55  * Basic structure for transmission/reception of a client XDR message.
56  * Features a header (for a linear buffer containing RPC headers
57  * and the data payload for short messages), and then an array of
58  * pages.
59  * The tail iovec allows you to append data after the page array. Its
60  * main interest is for appending padding to the pages in order to
61  * satisfy the int_32-alignment requirements in RFC1832.
62  *
63  * For the future, we might want to string several of these together
64  * in a list if anybody wants to make use of NFSv4 COMPOUND
65  * operations and/or has a need for scatter/gather involving pages.
66  */
67 struct xdr_buf {
68 	struct kvec	head[1],	/* RPC header + non-page data */
69 			tail[1];	/* Appended after page data */
70 
71 	struct page **	pages;		/* Array of contiguous pages */
72 	unsigned int	page_base,	/* Start of page data */
73 			page_len,	/* Length of page data */
74 			flags;		/* Flags for data disposition */
75 #define XDRBUF_READ		0x01		/* target of file read */
76 #define XDRBUF_WRITE		0x02		/* source of file write */
77 
78 	unsigned int	buflen,		/* Total length of storage buffer */
79 			len;		/* Length of XDR encoded message */
80 
81 };
82 
83 /*
84  * pre-xdr'ed macros.
85  */
86 
87 #define	xdr_zero	__constant_htonl(0)
88 #define	xdr_one		__constant_htonl(1)
89 #define	xdr_two		__constant_htonl(2)
90 
91 #define	rpc_success		__constant_htonl(RPC_SUCCESS)
92 #define	rpc_prog_unavail	__constant_htonl(RPC_PROG_UNAVAIL)
93 #define	rpc_prog_mismatch	__constant_htonl(RPC_PROG_MISMATCH)
94 #define	rpc_proc_unavail	__constant_htonl(RPC_PROC_UNAVAIL)
95 #define	rpc_garbage_args	__constant_htonl(RPC_GARBAGE_ARGS)
96 #define	rpc_system_err		__constant_htonl(RPC_SYSTEM_ERR)
97 #define	rpc_drop_reply		__constant_htonl(RPC_DROP_REPLY)
98 
99 #define	rpc_auth_ok		__constant_htonl(RPC_AUTH_OK)
100 #define	rpc_autherr_badcred	__constant_htonl(RPC_AUTH_BADCRED)
101 #define	rpc_autherr_rejectedcred __constant_htonl(RPC_AUTH_REJECTEDCRED)
102 #define	rpc_autherr_badverf	__constant_htonl(RPC_AUTH_BADVERF)
103 #define	rpc_autherr_rejectedverf __constant_htonl(RPC_AUTH_REJECTEDVERF)
104 #define	rpc_autherr_tooweak	__constant_htonl(RPC_AUTH_TOOWEAK)
105 #define	rpcsec_gsserr_credproblem	__constant_htonl(RPCSEC_GSS_CREDPROBLEM)
106 #define	rpcsec_gsserr_ctxproblem	__constant_htonl(RPCSEC_GSS_CTXPROBLEM)
107 #define	rpc_autherr_oldseqnum	__constant_htonl(101)
108 
109 /*
110  * Miscellaneous XDR helper functions
111  */
112 __be32 *xdr_encode_opaque_fixed(__be32 *p, const void *ptr, unsigned int len);
113 __be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int len);
114 __be32 *xdr_encode_string(__be32 *p, const char *s);
115 __be32 *xdr_decode_string_inplace(__be32 *p, char **sp, unsigned int *lenp,
116 			unsigned int maxlen);
117 __be32 *xdr_encode_netobj(__be32 *p, const struct xdr_netobj *);
118 __be32 *xdr_decode_netobj(__be32 *p, struct xdr_netobj *);
119 
120 void	xdr_encode_pages(struct xdr_buf *, struct page **, unsigned int,
121 			 unsigned int);
122 void	xdr_inline_pages(struct xdr_buf *, unsigned int,
123 			 struct page **, unsigned int, unsigned int);
124 
125 static inline __be32 *xdr_encode_array(__be32 *p, const void *s, unsigned int len)
126 {
127 	return xdr_encode_opaque(p, s, len);
128 }
129 
130 /*
131  * Decode 64bit quantities (NFSv3 support)
132  */
133 static inline __be32 *
134 xdr_encode_hyper(__be32 *p, __u64 val)
135 {
136 	*p++ = htonl(val >> 32);
137 	*p++ = htonl(val & 0xFFFFFFFF);
138 	return p;
139 }
140 
141 static inline __be32 *
142 xdr_decode_hyper(__be32 *p, __u64 *valp)
143 {
144 	*valp  = ((__u64) ntohl(*p++)) << 32;
145 	*valp |= ntohl(*p++);
146 	return p;
147 }
148 
149 /*
150  * Adjust kvec to reflect end of xdr'ed data (RPC client XDR)
151  */
152 static inline int
153 xdr_adjust_iovec(struct kvec *iov, __be32 *p)
154 {
155 	return iov->iov_len = ((u8 *) p - (u8 *) iov->iov_base);
156 }
157 
158 /*
159  * XDR buffer helper functions
160  */
161 extern void xdr_shift_buf(struct xdr_buf *, size_t);
162 extern void xdr_buf_from_iov(struct kvec *, struct xdr_buf *);
163 extern int xdr_buf_subsegment(struct xdr_buf *, struct xdr_buf *, unsigned int, unsigned int);
164 extern int xdr_buf_read_netobj(struct xdr_buf *, struct xdr_netobj *, unsigned int);
165 extern int read_bytes_from_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int);
166 extern int write_bytes_to_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int);
167 
168 /*
169  * Helper structure for copying from an sk_buff.
170  */
171 struct xdr_skb_reader {
172 	struct sk_buff	*skb;
173 	unsigned int	offset;
174 	size_t		count;
175 	__wsum		csum;
176 };
177 
178 typedef size_t (*xdr_skb_read_actor)(struct xdr_skb_reader *desc, void *to, size_t len);
179 
180 size_t xdr_skb_read_bits(struct xdr_skb_reader *desc, void *to, size_t len);
181 extern int csum_partial_copy_to_xdr(struct xdr_buf *, struct sk_buff *);
182 extern ssize_t xdr_partial_copy_from_skb(struct xdr_buf *, unsigned int,
183 		struct xdr_skb_reader *, xdr_skb_read_actor);
184 
185 extern int xdr_encode_word(struct xdr_buf *, unsigned int, u32);
186 extern int xdr_decode_word(struct xdr_buf *, unsigned int, u32 *);
187 
188 struct xdr_array2_desc;
189 typedef int (*xdr_xcode_elem_t)(struct xdr_array2_desc *desc, void *elem);
190 struct xdr_array2_desc {
191 	unsigned int elem_size;
192 	unsigned int array_len;
193 	unsigned int array_maxlen;
194 	xdr_xcode_elem_t xcode;
195 };
196 
197 extern int xdr_decode_array2(struct xdr_buf *buf, unsigned int base,
198                              struct xdr_array2_desc *desc);
199 extern int xdr_encode_array2(struct xdr_buf *buf, unsigned int base,
200 			     struct xdr_array2_desc *desc);
201 
202 /*
203  * Provide some simple tools for XDR buffer overflow-checking etc.
204  */
205 struct xdr_stream {
206 	__be32 *p;		/* start of available buffer */
207 	struct xdr_buf *buf;	/* XDR buffer to read/write */
208 
209 	__be32 *end;		/* end of available buffer space */
210 	struct kvec *iov;	/* pointer to the current kvec */
211 };
212 
213 extern void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p);
214 extern __be32 *xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes);
215 extern void xdr_write_pages(struct xdr_stream *xdr, struct page **pages,
216 		unsigned int base, unsigned int len);
217 extern void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p);
218 extern __be32 *xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes);
219 extern void xdr_read_pages(struct xdr_stream *xdr, unsigned int len);
220 extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len);
221 extern int xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data);
222 
223 #endif /* __KERNEL__ */
224 
225 #endif /* _SUNRPC_XDR_H_ */
226