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 1.5 2003/06/26 05:55:10 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 <compat/linux/linux_util.h>
43 const char linux_emul_path[] = "/compat/linux";
46 * Search an alternate path before passing pathname arguments on
47 * to system calls. Useful for keeping a separate 'emulation tree'.
49 * If cflag is set, we check if an attempt can be made to create
50 * the named file, i.e. we check if the directory it should
54 linux_emul_find(td, sgp, prefix, path, pbuf, cflag)
56 caddr_t *sgp; /* Pointer to stackgap memory */
63 struct nameidata ndroot;
71 KKASSERT(td->td_proc);
72 cred = td->td_proc->p_ucred;
74 buf = (char *) malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
77 for (ptr = buf; (*ptr = *prefix) != '\0'; ptr++, prefix++)
80 sz = MAXPATHLEN - (ptr - buf);
83 * If sgp is not given then the path is already in kernel space
86 error = copystr(path, ptr, sz, &len);
88 error = copyinstr(path, ptr, sz, &len);
101 * We know that there is a / somewhere in this pathname.
102 * Search backwards for it, to find the file's parent dir
103 * to see if it exists in the alternate tree. If it does,
104 * and we want to create a file (cflag is set). We don't
105 * need to worry about the root comparison in this case.
109 for (cp = &ptr[len] - 1; *cp != '/'; cp--);
112 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, buf, td);
114 if ((error = namei(&nd)) != 0) {
122 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, buf, td);
124 if ((error = namei(&nd)) != 0) {
130 * We now compare the vnode of the linux_root to the one
131 * vnode asked. If they resolve to be the same, then we
132 * ignore the match so that the real root gets used.
133 * This avoids the problem of traversing "../.." to find the
134 * root directory and never finding it, because "/" resolves
135 * to the emulation root directory. This is expensive :-(
137 NDINIT(&ndroot, LOOKUP, FOLLOW, UIO_SYSSPACE,
138 linux_emul_path, td);
140 if ((error = namei(&ndroot)) != 0) {
143 NDFREE(&nd, NDF_ONLY_PNBUF);
148 if ((error = VOP_GETATTR(nd.ni_vp, &vat, td)) != 0) {
152 if ((error = VOP_GETATTR(ndroot.ni_vp, &vatroot, td))
157 if (vat.va_fsid == vatroot.va_fsid &&
158 vat.va_fileid == vatroot.va_fileid) {
167 sz = &ptr[len] - buf;
168 *pbuf = stackgap_alloc(sgp, sz + 1);
170 error = copyout(buf, *pbuf, sz);
172 error = ENAMETOOLONG;
176 NDFREE(&nd, NDF_ONLY_PNBUF);
179 NDFREE(&ndroot, NDF_ONLY_PNBUF);
185 NDFREE(&ndroot, NDF_ONLY_PNBUF);
187 NDFREE(&nd, NDF_ONLY_PNBUF);