diff options
Diffstat (limited to 'sys/compat/linux/linux_util.c')
| -rw-r--r-- | sys/compat/linux/linux_util.c | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/sys/compat/linux/linux_util.c b/sys/compat/linux/linux_util.c new file mode 100644 index 0000000..1785fd3 --- /dev/null +++ b/sys/compat/linux/linux_util.c @@ -0,0 +1,179 @@ +/* + * Copyright (c) 1994 Christos Zoulas + * Copyright (c) 1995 Frank van der Linden + * Copyright (c) 1995 Scott Bartram + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * from: svr4_util.c,v 1.5 1995/01/22 23:44:50 christos Exp + * $Id$ + */ + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/namei.h> +#include <sys/proc.h> +#include <sys/file.h> +#include <sys/stat.h> +#include <sys/filedesc.h> +#include <sys/ioctl.h> +#include <sys/kernel.h> +#include <sys/malloc.h> +#include <sys/vnode.h> + +#include <i386/linux/linux_util.h> + +const char linux_emul_path[] = "/compat/linux"; + +/* + * Search an alternate path before passing pathname arguments on + * to system calls. Useful for keeping a seperate 'emulation tree'. + * + * If cflag is set, we check if an attempt can be made to create + * the named file, i.e. we check if the directory it should + * be in exists. + */ +int +linux_emul_find(p, sgp, prefix, path, pbuf, cflag) + struct proc *p; + caddr_t *sgp; /* Pointer to stackgap memory */ + const char *prefix; + char *path; + char **pbuf; + int cflag; +{ + struct nameidata nd; + struct nameidata ndroot; + struct vattr vat; + struct vattr vatroot; + int error; + char *ptr, *buf, *cp; + size_t sz, len; + + buf = (char *) malloc(MAXPATHLEN, M_TEMP, M_WAITOK); + *pbuf = path; + + for (ptr = buf; (*ptr = *prefix) != '\0'; ptr++, prefix++) + continue; + + sz = MAXPATHLEN - (ptr - buf); + + /* + * If sgp is not given then the path is already in kernel space + */ + if (sgp == NULL) + error = copystr(path, ptr, sz, &len); + else + error = copyinstr(path, ptr, sz, &len); + + if (error) { + free(buf, M_TEMP); + return error; + } + + if (*ptr != '/') { + free(buf, M_TEMP); + return EINVAL; + } + + /* + * We know that there is a / somewhere in this pathname. + * Search backwards for it, to find the file's parent dir + * to see if it exists in the alternate tree. If it does, + * and we want to create a file (cflag is set). We don't + * need to worry about the root comparison in this case. + */ + + if (cflag) { + for (cp = &ptr[len] - 1; *cp != '/'; cp--); + *cp = '\0'; + + NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, buf, p); + + if ((error = namei(&nd)) != 0) { + free(buf, M_TEMP); + return error; + } + + *cp = '/'; + } + else { + NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, buf, p); + + if ((error = namei(&nd)) != 0) { + free(buf, M_TEMP); + return error; + } + + /* + * We now compare the vnode of the linux_root to the one + * vnode asked. If they resolve to be the same, then we + * ignore the match so that the real root gets used. + * This avoids the problem of traversing "../.." to find the + * root directory and never finding it, because "/" resolves + * to the emulation root directory. This is expensive :-( + */ + /* XXX: prototype should have const here for NDINIT */ + NDINIT(&ndroot, LOOKUP, FOLLOW, UIO_SYSSPACE, + (char *) linux_emul_path, p); + + if ((error = namei(&ndroot)) != 0) { + /* Cannot happen! */ + free(buf, M_TEMP); + vrele(nd.ni_vp); + return error; + } + + if ((error = VOP_GETATTR(nd.ni_vp, &vat, p->p_ucred, p)) != 0) { + goto done; + } + + if ((error = VOP_GETATTR(ndroot.ni_vp, &vatroot, p->p_ucred, p)) + != 0) { + goto done; + } + + if (vat.va_fsid == vatroot.va_fsid && + vat.va_fileid == vatroot.va_fileid) { + error = ENOENT; + goto done; + } + + } + if (sgp == NULL) + *pbuf = buf; + else { + sz = &ptr[len] - buf; + *pbuf = stackgap_alloc(sgp, sz + 1); + error = copyout(buf, *pbuf, sz); + free(buf, M_TEMP); + } + + +done: + vrele(nd.ni_vp); + if (!cflag) + vrele(ndroot.ni_vp); + return error; +} |
