xref: /netbsd-src/sys/compat/common/compat_util.c (revision d91f98a8715141154279122ae81737cb65179572)
1 /* 	$NetBSD: compat_util.c,v 1.47 2019/01/27 02:08:39 pgoyette 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 /*
33  * Copyright (c) 2008, 2009 Matthew R. Green
34  * All rights reserved.
35  *
36  * Redistribution and use in source and binary forms, with or without
37  * modification, are permitted provided that the following conditions
38  * are met:
39  * 1. Redistributions of source code must retain the above copyright
40  *    notice, this list of conditions and the following disclaimer.
41  * 2. Redistributions in binary form must reproduce the above copyright
42  *    notice, this list of conditions and the following disclaimer in the
43  *    documentation and/or other materials provided with the distribution.
44  * 3. The name of the author may not be used to endorse or promote products
45  *    derived from this software without specific prior written permission.
46  *
47  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
48  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
49  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
50  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
51  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
52  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
53  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
54  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
55  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
56  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
57  * SUCH DAMAGE.
58  */
59 
60 #include <sys/cdefs.h>
61 __KERNEL_RCSID(0, "$NetBSD: compat_util.c,v 1.47 2019/01/27 02:08:39 pgoyette Exp $");
62 
63 #if defined(_KERNEL_OPT)
64 #include "opt_compat_netbsd.h"
65 #endif
66 
67 #include <sys/param.h>
68 #include <sys/systm.h>
69 #include <sys/namei.h>
70 #include <sys/proc.h>
71 #include <sys/file.h>
72 #include <sys/stat.h>
73 #include <sys/filedesc.h>
74 #include <sys/exec.h>
75 #include <sys/ioctl.h>
76 #include <sys/kernel.h>
77 #include <sys/vnode.h>
78 #include <sys/syslog.h>
79 #include <sys/mount.h>
80 #include <sys/module.h>
81 
82 #include <compat/common/compat_util.h>
83 
84 /*
85  * Translate one set of flags to another, based on the entries in
86  * the given table.  If 'leftover' is specified, it is filled in
87  * with any flags which could not be translated.
88  */
89 unsigned long
emul_flags_translate(const struct emul_flags_xtab * tab,unsigned long in,unsigned long * leftover)90 emul_flags_translate(const struct emul_flags_xtab *tab,
91 		     unsigned long in, unsigned long *leftover)
92 {
93 	unsigned long out;
94 
95 	for (out = 0; tab->omask != 0; tab++) {
96 		if ((in & tab->omask) == tab->oval) {
97 			in &= ~tab->omask;
98 			out |= tab->nval;
99 		}
100 	}
101 	if (leftover != NULL)
102 		*leftover = in;
103 	return (out);
104 }
105 
106 void
compat_offseterr(struct vnode * vp,const char * msg)107 compat_offseterr(struct vnode *vp, const char *msg)
108 {
109 	struct mount *mp;
110 
111 	mp = vp->v_mount;
112 
113 	log(LOG_ERR, "%s: dir offset too large on fs %s (mounted from %s)\n",
114 	    msg, mp->mnt_stat.f_mntonname, mp->mnt_stat.f_mntfromname);
115 	uprintf("%s: dir offset too large for emulated program\n", msg);
116 }
117 
118 /*
119  * Look for native NetBSD compatibility libraries, usually interp-ABI.
120  * It returns 0 if it changed the interpreter, otherwise it returns
121  * the error from namei().  Callers should not try any more processing
122  * if this returns 0, and probably should just ignore the return value.
123  */
124 int
compat_elf_check_interp(struct exec_package * epp,char * interp,const char * interp_suffix)125 compat_elf_check_interp(struct exec_package *epp,
126 			char *interp,
127 			const char *interp_suffix)
128 {
129 	int error = 0;
130 
131 	/*
132 	 * Don't look for something else, if someone has already found and
133 	 * setup the ep_interp already.
134 	 */
135 	if (interp && epp->ep_interp == NULL) {
136 		/*
137 		 * If the path is exactly "/usr/libexec/ld.elf_so", first
138 		 * try to see if "/usr/libexec/ld.elf_so-<abi>" exists
139 		 * and if so, use that instead.
140 		 */
141 		if (strcmp(interp, "/usr/libexec/ld.elf_so") == 0 ||
142 		    strcmp(interp, "/libexec/ld.elf_so") == 0) {
143 			struct vnode *vp;
144 			char *path;
145 
146 			path = PNBUF_GET();
147 			snprintf(path, MAXPATHLEN, "%s-%s", interp, interp_suffix);
148 			error = namei_simple_kernel(path,
149 					NSM_FOLLOW_NOEMULROOT, &vp);
150 			/*
151 			 * If that worked, replace interpreter in case we
152 			 * actually need to load it.
153 			 */
154 			if (error == 0) {
155 				epp->ep_interp = vp;
156 				snprintf(interp, MAXPATHLEN, "%s", path);
157 			}
158 			PNBUF_PUT(path);
159 		}
160 	}
161 	return error;
162 }
163 
164 MODULE(MODULE_CLASS_MISC, compat_util, NULL);
165 
166 int
compat_util_modcmd(modcmd_t cmd,void * arg)167 compat_util_modcmd(modcmd_t cmd, void *arg)
168 {
169 
170 	switch (cmd) {
171 	case MODULE_CMD_INIT:
172 	case MODULE_CMD_FINI:
173 		return 0;
174 	default:
175 		return ENOTTY;
176 	}
177 }
178