2 * Copyright (c) 1994 Christos Zoulas
3 * Copyright (c) 1995 Frank van der Linden
4 * Copyright (c) 1995 Scott Bartram
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. The name of the author may not be used to endorse or promote products
16 * derived from this software without specific prior written permission
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 * from: svr4_util.c,v 1.5 1995/01/22 23:44:50 christos Exp
30 * $FreeBSD: src/sys/compat/linux/linux_util.c,v 1.12.2.2 2001/11/05 19:08:23 marcel Exp $
31 * $DragonFly: src/sys/emulation/linux/linux_util.c,v 1.9 2004/09/09 20:52:19 dillon Exp $
34 #include <sys/param.h>
35 #include <sys/systm.h>
37 #include <sys/namei.h>
38 #include <sys/malloc.h>
39 #include <sys/vnode.h>
41 #include "linux_util.h"
43 const char linux_emul_path[] = "/compat/linux";
46 * Search for an alternate path before passing pathname arguments on
49 * Only signal an error if something really bad happens. In most cases
50 * we can just return the untranslated path, eg. name lookup failures.
53 linux_copyin_path(char *uname, char **kname, int flags)
55 struct thread *td = curthread;
56 struct nameidata nd, ndroot;
57 struct vattr vat, vatroot;
59 int error, length, dummy;
61 buf = (char *) malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
65 * Don't bother trying to translate if the path is relative.
67 if (fubyte(uname) != '/')
71 * The path is absolute. Prepend the buffer with the emulation
74 length = strlen(linux_emul_path);
75 bcopy(linux_emul_path, buf, length);
76 error = copyinstr(uname, buf + length, MAXPATHLEN - length, &dummy);
81 case LINUX_PATH_CREATE:
83 * Check to see if the parent directory exists in the
84 * emulation tree. Walk the string backwards to find
87 cp = buf + strlen(buf);
96 NDINIT(&nd, NAMEI_LOOKUP, CNP_FOLLOW, UIO_SYSSPACE, buf, td);
100 NDFREE(&nd, NDF_ONLY_PNBUF);
104 case LINUX_PATH_EXISTS:
105 NDINIT(&nd, NAMEI_LOOKUP, CNP_FOLLOW, UIO_SYSSPACE, buf, td);
111 * We now compare the vnode of the linux_root to the one
112 * vnode asked. If they resolve to be the same, then we
113 * ignore the match so that the real root gets used.
114 * This avoids the problem of traversing "../.." to find the
115 * root directory and never finding it, because "/" resolves
116 * to the emulation root directory. This is expensive :-(
118 * The next three function calls should not return errors.
119 * If they do something is seriously wrong, eg. the
120 * emulation subtree does not exist. Cross our fingers
121 * and return the untranslated path if something happens.
123 NDINIT(&ndroot, NAMEI_LOOKUP, CNP_FOLLOW, UIO_SYSSPACE,
124 linux_emul_path, td);
125 error = namei(&ndroot);
127 NDFREE(&nd, NDF_ONLY_PNBUF);
132 error = VOP_GETATTR(nd.ni_vp, &vat, td);
134 error = VOP_GETATTR(ndroot.ni_vp, &vatroot, td);
136 if (vat.va_fsid == vatroot.va_fsid &&
137 vat.va_fileid == vatroot.va_fileid)
141 NDFREE(&nd, NDF_ONLY_PNBUF);
143 NDFREE(&ndroot, NDF_ONLY_PNBUF);
154 error = copyinstr(uname, buf, MAXPATHLEN, &dummy);
157 linux_free_path(kname);
162 * Smaller version of the above for translating in kernel buffers. Only
163 * used in exec_linux_imgact_try(). Only check is path exists.
166 linux_translate_path(char *path, int size)
168 struct thread *td = curthread;
171 int error, length, dummy;
173 buf = (char *) malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
174 length = strlen(linux_emul_path);
175 bcopy(linux_emul_path, buf, length);
176 error = copystr(path, buf + length, MAXPATHLEN - length, &dummy);
181 * If this errors, then the path probably doesn't exists.
183 NDINIT(&nd, NAMEI_LOOKUP, CNP_FOLLOW, UIO_SYSSPACE, buf, td);
189 NDFREE(&nd, NDF_ONLY_PNBUF);
193 * The alternate path does exist. Return it in the buffer if
196 if (strlen(buf) + 1 <= size)
197 error = copystr(buf, path, size, &dummy);