1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1989, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Rick Macklem at The University of Guelph.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35#ifndef _NFS_NFSM_SUBS_H_
36#define _NFS_NFSM_SUBS_H_
37
38/*
39 * These macros do strange and peculiar things to mbuf chains for
40 * the assistance of the nfs code. To attempt to use them for any
41 * other purpose will be dangerous. (they make weird assumptions)
42 */
43
44/*
45 * First define what the actual subs. return
46 */
47#define NFSM_DATAP(m, s) (m)->m_data += (s)
48
49/*
50 * Now for the macros that do the simple stuff and call the functions
51 * for the hard stuff.
52 * They use fields in struct nfsrv_descript to handle the mbuf queues.
53 * Replace most of the macro with an inline function, to minimize
54 * the machine code. The inline functions in lower case can be called
55 * directly, bypassing the macro.
56 */
57static __inline void *
58nfsm_build(struct nfsrv_descript *nd, int siz)
59{
60 void *retp;
61 struct mbuf *mb2;
62
63 if ((nd->nd_flag & ND_EXTPG) == 0 &&
64 siz > M_TRAILINGSPACE(nd->nd_mb)) {
65 NFSMCLGET(mb2, M_NOWAIT);
66 if (siz > MLEN)
67 panic("build > MLEN");
68 mb2->m_len = 0;
69 nd->nd_bpos = mtod(mb2, char *);
70 nd->nd_mb->m_next = mb2;
71 nd->nd_mb = mb2;
72 } else if ((nd->nd_flag & ND_EXTPG) != 0) {
73 if (siz > nd->nd_bextpgsiz) {
74 mb2 = mb_alloc_ext_plus_pages(PAGE_SIZE, M_WAITOK);
75 nd->nd_bpos = (char *)(void *)
76 PHYS_TO_DMAP(mb2->m_epg_pa[0]);
77 nd->nd_bextpg = 0;
78 nd->nd_bextpgsiz = PAGE_SIZE - siz;
79 nd->nd_mb->m_next = mb2;
80 nd->nd_mb = mb2;
81 } else
82 nd->nd_bextpgsiz -= siz;
83 nd->nd_mb->m_epg_last_len += siz;
84 }
85 retp = (void *)(nd->nd_bpos);
86 nd->nd_mb->m_len += siz;
87 nd->nd_bpos += siz;
88 return (retp);
89}
90
91#define NFSM_BUILD(a, c, s) ((a) = (c)nfsm_build(nd, (s)))
92
93static __inline void *
94nfsm_dissect(struct nfsrv_descript *nd, int siz)
95{
96 int tt1;
97 void *retp;
98
99 tt1 = mtod(nd->nd_md, caddr_t) + nd->nd_md->m_len - nd->nd_dpos;
100 if (tt1 >= siz) {
101 retp = (void *)nd->nd_dpos;
102 nd->nd_dpos += siz;
103 } else {
104 retp = nfsm_dissct(nd, siz, M_WAITOK);
105 }
106 return (retp);
107}
108
109static __inline void *
110nfsm_dissect_nonblock(struct nfsrv_descript *nd, int siz)
111{
112 int tt1;
113 void *retp;
114
115 tt1 = mtod(nd->nd_md, caddr_t) + nd->nd_md->m_len - nd->nd_dpos;
116 if (tt1 >= siz) {
117 retp = (void *)nd->nd_dpos;
118 nd->nd_dpos += siz;
119 } else {
120 retp = nfsm_dissct(nd, siz, M_NOWAIT);
121 }
122 return (retp);
123}
124
125#define NFSM_DISSECT(a, c, s) \
126 do { \
127 (a) = (c)nfsm_dissect(nd, (s)); \
128 if ((a) == NULL) { \
129 error = EBADRPC; \
130 goto nfsmout; \
131 } \
132 } while (0)
133
134#define NFSM_DISSECT_NONBLOCK(a, c, s) \
135 do { \
136 (a) = (c)nfsm_dissect_nonblock(nd, (s)); \
137 if ((a) == NULL) { \
138 error = EBADRPC; \
139 goto nfsmout; \
140 } \
141 } while (0)
142
143#define NFSM_STRSIZ(s, m) \
144 do { \
145 tl = (u_int32_t *)nfsm_dissect(nd, NFSX_UNSIGNED); \
146 if (!tl || ((s) = fxdr_unsigned(int32_t, *tl)) > (m)) { \
147 error = EBADRPC; \
148 goto nfsmout; \
149 } \
150 } while (0)
151
152#define NFSM_RNDUP(a) (((a)+3)&(~0x3))
153
154#endif /* _NFS_NFSM_SUBS_H_ */