xref: /netbsd-src/sys/compat/common/compat_util.c (revision 7c3f385475147b6e1c4753f2bee961630e2dfc40)
1 /* 	$NetBSD: compat_util.c,v 1.40 2007/12/31 15:32:09 ad Exp $	*/
2 
3 /*-
4  * Copyright (c) 1994 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Christos Zoulas and Frank van der Linden.
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. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *        This product includes software developed by the NetBSD
21  *        Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 #include <sys/cdefs.h>
40 __KERNEL_RCSID(0, "$NetBSD: compat_util.c,v 1.40 2007/12/31 15:32:09 ad Exp $");
41 
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/namei.h>
45 #include <sys/proc.h>
46 #include <sys/file.h>
47 #include <sys/stat.h>
48 #include <sys/filedesc.h>
49 #include <sys/exec.h>
50 #include <sys/ioctl.h>
51 #include <sys/kernel.h>
52 #include <sys/malloc.h>
53 #include <sys/vnode.h>
54 #include <sys/syslog.h>
55 #include <sys/mount.h>
56 
57 #include <compat/common/compat_util.h>
58 
59 void
60 emul_find_root(struct lwp *l, struct exec_package *epp)
61 {
62 	struct nameidata nd;
63 	const char *emul_path;
64 
65 	if (epp->ep_emul_root != NULL)
66 		/* We've already found it */
67 		return;
68 
69 	emul_path = epp->ep_esch->es_emul->e_path;
70 	if (emul_path == NULL)
71 		/* Emulation doesn't have a root */
72 		return;
73 
74 	NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, emul_path);
75 	if (namei(&nd) != 0)
76 		/* emulation root doesn't exist */
77 		return;
78 
79 	epp->ep_emul_root = nd.ni_vp;
80 }
81 
82 /*
83  * Search the alternate path for dynamic binary interpreter. If not found
84  * there, check if the interpreter exists in within 'proper' tree.
85  */
86 int
87 emul_find_interp(struct lwp *l, struct exec_package *epp, const char *itp)
88 {
89 	int error;
90 	struct nameidata nd;
91 	unsigned int flags;
92 
93 	/* If we haven't found the emulation root already, do so now */
94 	/* Maybe we should remember failures somehow ? */
95 	if (epp->ep_esch->es_emul->e_path != 0 && epp->ep_emul_root == NULL)
96 		emul_find_root(l, epp);
97 
98 	if (epp->ep_interp != NULL)
99 		vrele(epp->ep_interp);
100 
101 	/* We need to use the emulation root for the new program,
102 	 * not the one for the current process. */
103 	if (epp->ep_emul_root == NULL)
104 		flags = FOLLOW;
105 	else {
106 		nd.ni_erootdir = epp->ep_emul_root;
107 		/* hack: Pass in the emulation path for ktrace calls */
108 		nd.ni_next = epp->ep_esch->es_emul->e_path;
109 		flags = FOLLOW | TRYEMULROOT | EMULROOTSET;
110 	}
111 
112 	NDINIT(&nd, LOOKUP, flags, UIO_SYSSPACE, itp);
113 	error = namei(&nd);
114 	if (error != 0) {
115 		epp->ep_interp = NULL;
116 		return error;
117 	}
118 
119 	/* Save interpreter in case we actually need to load it */
120 	epp->ep_interp = nd.ni_vp;
121 
122 	return 0;
123 }
124 
125 /*
126  * Translate one set of flags to another, based on the entries in
127  * the given table.  If 'leftover' is specified, it is filled in
128  * with any flags which could not be translated.
129  */
130 unsigned long
131 emul_flags_translate(const struct emul_flags_xtab *tab,
132 		     unsigned long in, unsigned long *leftover)
133 {
134 	unsigned long out;
135 
136 	for (out = 0; tab->omask != 0; tab++) {
137 		if ((in & tab->omask) == tab->oval) {
138 			in &= ~tab->omask;
139 			out |= tab->nval;
140 		}
141 	}
142 	if (leftover != NULL)
143 		*leftover = in;
144 	return (out);
145 }
146 
147 void
148 compat_offseterr(struct vnode *vp, const char *msg)
149 {
150 	struct mount *mp;
151 
152 	mp = vp->v_mount;
153 
154 	log(LOG_ERR, "%s: dir offset too large on fs %s (mounted from %s)\n",
155 	    msg, mp->mnt_stat.f_mntonname, mp->mnt_stat.f_mntfromname);
156 	uprintf("%s: dir offset too large for emulated program\n", msg);
157 }
158