1/* 	$NetBSD$	*/
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, "$NetBSD$");
62
63#include <sys/param.h>
64#include <sys/systm.h>
65#include <sys/namei.h>
66#include <sys/proc.h>
67#include <sys/file.h>
68#include <sys/stat.h>
69#include <sys/filedesc.h>
70#include <sys/exec.h>
71#include <sys/ioctl.h>
72#include <sys/kernel.h>
73#include <sys/malloc.h>
74#include <sys/vnode.h>
75#include <sys/syslog.h>
76#include <sys/mount.h>
77
78#include <compat/common/compat_util.h>
79
80void
81emul_find_root(struct lwp *l, struct exec_package *epp)
82{
83	struct vnode *vp;
84	const char *emul_path;
85
86	if (epp->ep_emul_root != NULL)
87		/* We've already found it */
88		return;
89
90	emul_path = epp->ep_esch->es_emul->e_path;
91	if (emul_path == NULL)
92		/* Emulation doesn't have a root */
93		return;
94
95	if (namei_simple_kernel(emul_path, NSM_FOLLOW_NOEMULROOT, &vp) != 0)
96		/* emulation root doesn't exist */
97		return;
98
99	epp->ep_emul_root = vp;
100}
101
102/*
103 * Search the alternate path for dynamic binary interpreter. If not found
104 * there, check if the interpreter exists in within 'proper' tree.
105 */
106int
107emul_find_interp(struct lwp *l, struct exec_package *epp, const char *itp)
108{
109	int error;
110	struct pathbuf *pb;
111	struct nameidata nd;
112	unsigned int flags;
113
114	pb = pathbuf_create(itp);
115	if (pb == NULL) {
116		return ENOMEM;
117	}
118
119	/* If we haven't found the emulation root already, do so now */
120	/* Maybe we should remember failures somehow ? */
121	if (epp->ep_esch->es_emul->e_path != 0 && epp->ep_emul_root == NULL)
122		emul_find_root(l, epp);
123
124	if (epp->ep_interp != NULL)
125		vrele(epp->ep_interp);
126
127	/* We need to use the emulation root for the new program,
128	 * not the one for the current process. */
129	if (epp->ep_emul_root == NULL)
130		flags = FOLLOW;
131	else {
132		nd.ni_erootdir = epp->ep_emul_root;
133		/* hack: Pass in the emulation path for ktrace calls */
134		nd.ni_next = epp->ep_esch->es_emul->e_path;
135		flags = FOLLOW | TRYEMULROOT | EMULROOTSET;
136	}
137
138	NDINIT(&nd, LOOKUP, flags, pb);
139	error = namei(&nd);
140	if (error != 0) {
141		epp->ep_interp = NULL;
142		pathbuf_destroy(pb);
143		return error;
144	}
145
146	/* Save interpreter in case we actually need to load it */
147	epp->ep_interp = nd.ni_vp;
148
149	pathbuf_destroy(pb);
150
151	return 0;
152}
153
154/*
155 * Translate one set of flags to another, based on the entries in
156 * the given table.  If 'leftover' is specified, it is filled in
157 * with any flags which could not be translated.
158 */
159unsigned long
160emul_flags_translate(const struct emul_flags_xtab *tab,
161		     unsigned long in, unsigned long *leftover)
162{
163	unsigned long out;
164
165	for (out = 0; tab->omask != 0; tab++) {
166		if ((in & tab->omask) == tab->oval) {
167			in &= ~tab->omask;
168			out |= tab->nval;
169		}
170	}
171	if (leftover != NULL)
172		*leftover = in;
173	return (out);
174}
175
176void
177compat_offseterr(struct vnode *vp, const char *msg)
178{
179	struct mount *mp;
180
181	mp = vp->v_mount;
182
183	log(LOG_ERR, "%s: dir offset too large on fs %s (mounted from %s)\n",
184	    msg, mp->mnt_stat.f_mntonname, mp->mnt_stat.f_mntfromname);
185	uprintf("%s: dir offset too large for emulated program\n", msg);
186}
187
188/*
189 * Look for native NetBSD compatibility libraries, usually interp-ABI.
190 * It returns 0 if it changed the interpreter, otherwise it returns
191 * the error from namei().  Callers should not try any more processing
192 * if this returns 0, and probably should just ignore the return value.
193 */
194int
195compat_elf_check_interp(struct exec_package *epp,
196			char *interp,
197			const char *interp_suffix)
198{
199	int error = 0;
200
201	/*
202	 * Don't look for something else, if someone has already found and
203	 * setup the ep_interp already.
204	 */
205	if (interp && epp->ep_interp == NULL) {
206		/*
207		 * If the path is exactly "/usr/libexec/ld.elf_so", first
208		 * try to see if "/usr/libexec/ld.elf_so-<abi>" exists
209		 * and if so, use that instead.
210		 */
211		if (strcmp(interp, "/usr/libexec/ld.elf_so") == 0 ||
212		    strcmp(interp, "/libexec/ld.elf_so") == 0) {
213			struct vnode *vp;
214			char *path;
215
216			path = PNBUF_GET();
217			snprintf(path, MAXPATHLEN, "%s-%s", interp, interp_suffix);
218			error = namei_simple_kernel(path,
219					NSM_FOLLOW_NOEMULROOT, &vp);
220			/*
221			 * If that worked, replace interpreter in case we
222			 * actually need to load it.
223			 */
224			if (error == 0) {
225				epp->ep_interp = vp;
226				snprintf(interp, MAXPATHLEN, "%s", path);
227			}
228			PNBUF_PUT(path);
229		}
230	}
231	return error;
232}
233