nfsm_subs.h revision 331722 
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 * 4. 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: stable/11/sys/fs/nfs/nfsm_subs.h 331722 2018-03-29 02:50:57Z eadler $
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 */
59static __inline void *
60nfsm_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
82static __inline void *
83nfsm_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
98static __inline void *
99nfsm_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