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 
14 /*
15  * Buffer adjustment
16  */
17 #define XDR_QUADLEN(l)		(((l) + 3) >> 2)
18 
19 /*
20  * Generic opaque `network object.' At the kernel level, this type
21  * is used only by lockd.
22  */
23 #define XDR_MAX_NETOBJ		1024
24 struct xdr_netobj {
25 	unsigned int		len;
26 	u8 *			data;
27 };
28 
29 /*
30  * This is the generic XDR function. rqstp is either a rpc_rqst (client
31  * side) or svc_rqst pointer (server side).
32  * Encode functions always assume there's enough room in the buffer.
33  */
34 typedef int	(*kxdrproc_t)(void *rqstp, u32 *data, void *obj);
35 
36 /*
37  * Basic structure for transmission/reception of a client XDR message.
38  * Features a header (for a linear buffer containing RPC headers
39  * and the data payload for short messages), and then an array of
40  * pages.
41  * The tail iovec allows you to append data after the page array. Its
42  * main interest is for appending padding to the pages in order to
43  * satisfy the int_32-alignment requirements in RFC1832.
44  *
45  * For the future, we might want to string several of these together
46  * in a list if anybody wants to make use of NFSv4 COMPOUND
47  * operations and/or has a need for scatter/gather involving pages.
48  */
49 struct xdr_buf {
50 	struct iovec	head[1],	/* RPC header + non-page data */
51 			tail[1];	/* Appended after page data */
52 
53 	struct page **	pages;		/* Array of contiguous pages */
54 	unsigned int	page_base,	/* Start of page data */
55 			page_len;	/* Length of page data */
56 
57 	unsigned int	len;		/* Total length of data */
58 
59 };
60 
61 /*
62  * pre-xdr'ed macros.
63  */
64 
65 #define	xdr_zero	__constant_htonl(0)
66 #define	xdr_one		__constant_htonl(1)
67 #define	xdr_two		__constant_htonl(2)
68 
69 #define	rpc_success		__constant_htonl(RPC_SUCCESS)
70 #define	rpc_prog_unavail	__constant_htonl(RPC_PROG_UNAVAIL)
71 #define	rpc_prog_mismatch	__constant_htonl(RPC_PROG_MISMATCH)
72 #define	rpc_proc_unavail	__constant_htonl(RPC_PROC_UNAVAIL)
73 #define	rpc_garbage_args	__constant_htonl(RPC_GARBAGE_ARGS)
74 #define	rpc_system_err		__constant_htonl(RPC_SYSTEM_ERR)
75 
76 #define	rpc_auth_ok		__constant_htonl(RPC_AUTH_OK)
77 #define	rpc_autherr_badcred	__constant_htonl(RPC_AUTH_BADCRED)
78 #define	rpc_autherr_rejectedcred __constant_htonl(RPC_AUTH_REJECTEDCRED)
79 #define	rpc_autherr_badverf	__constant_htonl(RPC_AUTH_BADVERF)
80 #define	rpc_autherr_rejectedverf __constant_htonl(RPC_AUTH_REJECTEDVERF)
81 #define	rpc_autherr_tooweak	__constant_htonl(RPC_AUTH_TOOWEAK)
82 
83 
84 /*
85  * Miscellaneous XDR helper functions
86  */
87 u32 *	xdr_encode_array(u32 *p, const char *s, unsigned int len);
88 u32 *	xdr_encode_string(u32 *p, const char *s);
89 u32 *	xdr_decode_string(u32 *p, char **sp, int *lenp, int maxlen);
90 u32 *	xdr_decode_string_inplace(u32 *p, char **sp, int *lenp, int maxlen);
91 u32 *	xdr_encode_netobj(u32 *p, const struct xdr_netobj *);
92 u32 *	xdr_decode_netobj(u32 *p, struct xdr_netobj *);
93 u32 *	xdr_decode_netobj_fixed(u32 *p, void *obj, unsigned int len);
94 
95 void	xdr_encode_pages(struct xdr_buf *, struct page **, unsigned int,
96 			 unsigned int);
97 void	xdr_inline_pages(struct xdr_buf *, unsigned int,
98 			 struct page **, unsigned int, unsigned int);
99 
100 /*
101  * Decode 64bit quantities (NFSv3 support)
102  */
103 static inline u32 *
xdr_encode_hyper(u32 * p,__u64 val)104 xdr_encode_hyper(u32 *p, __u64 val)
105 {
106 	*p++ = htonl(val >> 32);
107 	*p++ = htonl(val & 0xFFFFFFFF);
108 	return p;
109 }
110 
111 static inline u32 *
xdr_decode_hyper(u32 * p,__u64 * valp)112 xdr_decode_hyper(u32 *p, __u64 *valp)
113 {
114 	*valp  = ((__u64) ntohl(*p++)) << 32;
115 	*valp |= ntohl(*p++);
116 	return p;
117 }
118 
119 /*
120  * Adjust iovec to reflect end of xdr'ed data (RPC client XDR)
121  */
122 static inline int
xdr_adjust_iovec(struct iovec * iov,u32 * p)123 xdr_adjust_iovec(struct iovec *iov, u32 *p)
124 {
125 	return iov->iov_len = ((u8 *) p - (u8 *) iov->iov_base);
126 }
127 
128 void xdr_shift_iovec(struct iovec *, int, size_t);
129 void xdr_zero_iovec(struct iovec *, int, size_t);
130 
131 /*
132  * Maximum number of iov's we use.
133  */
134 #define MAX_IOVEC	(12)
135 
136 /*
137  * XDR buffer helper functions
138  */
139 extern int xdr_kmap(struct iovec *, struct xdr_buf *, unsigned int);
140 extern void xdr_kunmap(struct xdr_buf *, unsigned int, int);
141 extern void xdr_shift_buf(struct xdr_buf *, size_t);
142 
143 /*
144  * Helper structure for copying from an sk_buff.
145  */
146 typedef struct {
147 	struct sk_buff	*skb;
148 	unsigned int	offset;
149 	size_t		count;
150 	unsigned int	csum;
151 } skb_reader_t;
152 
153 typedef size_t (*skb_read_actor_t)(skb_reader_t *desc, void *to, size_t len);
154 
155 extern void xdr_partial_copy_from_skb(struct xdr_buf *, unsigned int,
156 		skb_reader_t *, skb_read_actor_t);
157 
158 extern int xdr_copy_skb(struct xdr_buf *xdr, unsigned int base,
159 		struct sk_buff *skb, unsigned int offset);
160 
161 extern int xdr_copy_and_csum_skb(struct xdr_buf *xdr, unsigned int base,
162 		struct sk_buff *skb, unsigned int offset, unsigned int csum);
163 
164 #endif /* __KERNEL__ */
165 
166 #endif /* _SUNRPC_XDR_H_ */
167