/* $OpenBSD: compat_util.c,v 1.4 1996/04/18 21:21:32 niklas Exp $ */ /* $NetBSD: compat_util.c,v 1.4 1996/03/14 19:31:45 christos Exp $ */ /* * Copyright (c) 1994 Christos Zoulas * Copyright (c) 1995 Frank van der Linden * 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. * */ #include #include #include #include #include #include #include #include #include #include #include #include /* * Search an alternate path before passing pathname arguments on * to system calls. Useful for keeping a separate '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 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; const char *pr; size_t sz, len; buf = (char *) malloc(MAXPATHLEN, M_TEMP, M_WAITOK); *pbuf = path; for (ptr = buf, pr = prefix; (*ptr = *pr) != '\0'; ptr++, pr++) 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) goto bad; if (*ptr != '/') { error = EINVAL; goto bad; } /* * 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) goto bad; *cp = '/'; } else { NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, buf, p); if ((error = namei(&nd)) != 0) goto bad; /* * We now compare the vnode of the emulation 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 *) prefix, p); if ((error = namei(&ndroot)) != 0) goto bad2; if ((error = VOP_GETATTR(nd.ni_vp, &vat, p->p_ucred, p)) != 0) goto bad3; if ((error = VOP_GETATTR(ndroot.ni_vp, &vatroot, p->p_ucred, p)) != 0) goto bad3; if (vat.va_fsid == vatroot.va_fsid && vat.va_fileid == vatroot.va_fileid) { error = ENOENT; goto bad3; } } 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); } vrele(nd.ni_vp); if (!cflag) vrele(ndroot.ni_vp); return error; bad3: vrele(ndroot.ni_vp); bad2: vrele(nd.ni_vp); bad: free(buf, M_TEMP); return error; }