xref: /freebsd/sys/fs/nfs/nfsm_subs.h (revision cbd30a72ca196976c1c700400ecd424baa1b9c16)
1 /*-
2  * Copyright (c) 1989, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Rick Macklem at The University of Guelph.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  * $FreeBSD$
33  */
34 
35 #ifndef _NFS_NFSM_SUBS_H_
36 #define	_NFS_NFSM_SUBS_H_
37 
38 
39 /*
40  * These macros do strange and peculiar things to mbuf chains for
41  * the assistance of the nfs code. To attempt to use them for any
42  * other purpose will be dangerous. (they make weird assumptions)
43  */
44 
45 #ifndef APPLE
46 /*
47  * First define what the actual subs. return
48  */
49 #define	NFSM_DATAP(m, s)	(m)->m_data += (s)
50 
51 /*
52  * Now for the macros that do the simple stuff and call the functions
53  * for the hard stuff.
54  * They use fields in struct nfsrv_descript to handle the mbuf queues.
55  * Replace most of the macro with an inline function, to minimize
56  * the machine code. The inline functions in lower case can be called
57  * directly, bypassing the macro.
58  */
59 static __inline void *
60 nfsm_build(struct nfsrv_descript *nd, int siz)
61 {
62 	void *retp;
63 	struct mbuf *mb2;
64 
65 	if (siz > M_TRAILINGSPACE(nd->nd_mb)) {
66 		NFSMCLGET(mb2, M_NOWAIT);
67 		if (siz > MLEN)
68 			panic("build > MLEN");
69 		mbuf_setlen(mb2, 0);
70 		nd->nd_bpos = NFSMTOD(mb2, caddr_t);
71 		nd->nd_mb->m_next = mb2;
72 		nd->nd_mb = mb2;
73 	}
74 	retp = (void *)(nd->nd_bpos);
75 	nd->nd_mb->m_len += siz;
76 	nd->nd_bpos += siz;
77 	return (retp);
78 }
79 
80 #define	NFSM_BUILD(a, c, s)	((a) = (c)nfsm_build(nd, (s)))
81 
82 static __inline void *
83 nfsm_dissect(struct nfsrv_descript *nd, int siz)
84 {
85 	int tt1;
86 	void *retp;
87 
88 	tt1 = NFSMTOD(nd->nd_md, caddr_t) + nd->nd_md->m_len - nd->nd_dpos;
89 	if (tt1 >= siz) {
90 		retp = (void *)nd->nd_dpos;
91 		nd->nd_dpos += siz;
92 	} else {
93 		retp = nfsm_dissct(nd, siz, M_WAITOK);
94 	}
95 	return (retp);
96 }
97 
98 static __inline void *
99 nfsm_dissect_nonblock(struct nfsrv_descript *nd, int siz)
100 {
101 	int tt1;
102 	void *retp;
103 
104 	tt1 = NFSMTOD(nd->nd_md, caddr_t) + nd->nd_md->m_len - nd->nd_dpos;
105 	if (tt1 >= siz) {
106 		retp = (void *)nd->nd_dpos;
107 		nd->nd_dpos += siz;
108 	} else {
109 		retp = nfsm_dissct(nd, siz, M_NOWAIT);
110 	}
111 	return (retp);
112 }
113 
114 #define	NFSM_DISSECT(a, c, s) 						\
115 	do {								\
116 		(a) = (c)nfsm_dissect(nd, (s));	 			\
117 		if ((a) == NULL) { 					\
118 			error = EBADRPC; 				\
119 			goto nfsmout; 					\
120 		}							\
121 	} while (0)
122 
123 #define	NFSM_DISSECT_NONBLOCK(a, c, s) 					\
124 	do {								\
125 		(a) = (c)nfsm_dissect_nonblock(nd, (s));		\
126 		if ((a) == NULL) { 					\
127 			error = EBADRPC; 				\
128 			goto nfsmout; 					\
129 		}							\
130 	} while (0)
131 #endif	/* !APPLE */
132 
133 #define	NFSM_STRSIZ(s, m)  						\
134 	do {								\
135 		tl = (u_int32_t *)nfsm_dissect(nd, NFSX_UNSIGNED);	\
136 		if (!tl || ((s) = fxdr_unsigned(int32_t, *tl)) > (m)) { \
137 			error = EBADRPC; 				\
138 			goto nfsmout; 					\
139 		}							\
140 	} while (0)
141 
142 #define	NFSM_RNDUP(a)	(((a)+3)&(~0x3))
143 
144 #endif	/* _NFS_NFSM_SUBS_H_ */
145