xref: /netbsd-src/sys/compat/common/compat_util.c (revision 6dffe8d42bd46273f674d7ab834e7be9b1af990e)
1 /* 	$NetBSD: compat_util.c,v 1.42 2009/06/29 05:08:15 dholland 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  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 __KERNEL_RCSID(0, "$NetBSD: compat_util.c,v 1.42 2009/06/29 05:08:15 dholland Exp $");
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/namei.h>
38 #include <sys/proc.h>
39 #include <sys/file.h>
40 #include <sys/stat.h>
41 #include <sys/filedesc.h>
42 #include <sys/exec.h>
43 #include <sys/ioctl.h>
44 #include <sys/kernel.h>
45 #include <sys/malloc.h>
46 #include <sys/vnode.h>
47 #include <sys/syslog.h>
48 #include <sys/mount.h>
49 
50 #include <compat/common/compat_util.h>
51 
52 void
53 emul_find_root(struct lwp *l, struct exec_package *epp)
54 {
55 	struct vnode *vp;
56 	const char *emul_path;
57 
58 	if (epp->ep_emul_root != NULL)
59 		/* We've already found it */
60 		return;
61 
62 	emul_path = epp->ep_esch->es_emul->e_path;
63 	if (emul_path == NULL)
64 		/* Emulation doesn't have a root */
65 		return;
66 
67 	if (namei_simple_kernel(emul_path, NSM_FOLLOW_NOEMULROOT, &vp) != 0)
68 		/* emulation root doesn't exist */
69 		return;
70 
71 	epp->ep_emul_root = vp;
72 }
73 
74 /*
75  * Search the alternate path for dynamic binary interpreter. If not found
76  * there, check if the interpreter exists in within 'proper' tree.
77  */
78 int
79 emul_find_interp(struct lwp *l, struct exec_package *epp, const char *itp)
80 {
81 	int error;
82 	struct nameidata nd;
83 	unsigned int flags;
84 
85 	/* If we haven't found the emulation root already, do so now */
86 	/* Maybe we should remember failures somehow ? */
87 	if (epp->ep_esch->es_emul->e_path != 0 && epp->ep_emul_root == NULL)
88 		emul_find_root(l, epp);
89 
90 	if (epp->ep_interp != NULL)
91 		vrele(epp->ep_interp);
92 
93 	/* We need to use the emulation root for the new program,
94 	 * not the one for the current process. */
95 	if (epp->ep_emul_root == NULL)
96 		flags = FOLLOW;
97 	else {
98 		nd.ni_erootdir = epp->ep_emul_root;
99 		/* hack: Pass in the emulation path for ktrace calls */
100 		nd.ni_next = epp->ep_esch->es_emul->e_path;
101 		flags = FOLLOW | TRYEMULROOT | EMULROOTSET;
102 	}
103 
104 	NDINIT(&nd, LOOKUP, flags, UIO_SYSSPACE, itp);
105 	error = namei(&nd);
106 	if (error != 0) {
107 		epp->ep_interp = NULL;
108 		return error;
109 	}
110 
111 	/* Save interpreter in case we actually need to load it */
112 	epp->ep_interp = nd.ni_vp;
113 
114 	return 0;
115 }
116 
117 /*
118  * Translate one set of flags to another, based on the entries in
119  * the given table.  If 'leftover' is specified, it is filled in
120  * with any flags which could not be translated.
121  */
122 unsigned long
123 emul_flags_translate(const struct emul_flags_xtab *tab,
124 		     unsigned long in, unsigned long *leftover)
125 {
126 	unsigned long out;
127 
128 	for (out = 0; tab->omask != 0; tab++) {
129 		if ((in & tab->omask) == tab->oval) {
130 			in &= ~tab->omask;
131 			out |= tab->nval;
132 		}
133 	}
134 	if (leftover != NULL)
135 		*leftover = in;
136 	return (out);
137 }
138 
139 void
140 compat_offseterr(struct vnode *vp, const char *msg)
141 {
142 	struct mount *mp;
143 
144 	mp = vp->v_mount;
145 
146 	log(LOG_ERR, "%s: dir offset too large on fs %s (mounted from %s)\n",
147 	    msg, mp->mnt_stat.f_mntonname, mp->mnt_stat.f_mntfromname);
148 	uprintf("%s: dir offset too large for emulated program\n", msg);
149 }
150