1d66a5066SPeter Wemm /* 2d66a5066SPeter Wemm * Copyright (c) 1994 Christos Zoulas 3d66a5066SPeter Wemm * Copyright (c) 1995 Frank van der Linden 4d66a5066SPeter Wemm * Copyright (c) 1995 Scott Bartram 5d66a5066SPeter Wemm * All rights reserved. 6d66a5066SPeter Wemm * 7d66a5066SPeter Wemm * Redistribution and use in source and binary forms, with or without 8d66a5066SPeter Wemm * modification, are permitted provided that the following conditions 9d66a5066SPeter Wemm * are met: 10d66a5066SPeter Wemm * 1. Redistributions of source code must retain the above copyright 11d66a5066SPeter Wemm * notice, this list of conditions and the following disclaimer. 12d66a5066SPeter Wemm * 2. Redistributions in binary form must reproduce the above copyright 13d66a5066SPeter Wemm * notice, this list of conditions and the following disclaimer in the 14d66a5066SPeter Wemm * documentation and/or other materials provided with the distribution. 15d66a5066SPeter Wemm * 3. The name of the author may not be used to endorse or promote products 16d66a5066SPeter Wemm * derived from this software without specific prior written permission 17d66a5066SPeter Wemm * 18d66a5066SPeter Wemm * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19d66a5066SPeter Wemm * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20d66a5066SPeter Wemm * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21d66a5066SPeter Wemm * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22d66a5066SPeter Wemm * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23d66a5066SPeter Wemm * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24d66a5066SPeter Wemm * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25d66a5066SPeter Wemm * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26d66a5066SPeter Wemm * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27d66a5066SPeter Wemm * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28d66a5066SPeter Wemm * 29d66a5066SPeter Wemm * from: svr4_util.c,v 1.5 1995/01/22 23:44:50 christos Exp 30c3aac50fSPeter Wemm * $FreeBSD$ 31d66a5066SPeter Wemm */ 32d66a5066SPeter Wemm 33d66a5066SPeter Wemm #include <sys/param.h> 34d66a5066SPeter Wemm #include <sys/systm.h> 35d66a5066SPeter Wemm #include <sys/namei.h> 36d66a5066SPeter Wemm #include <sys/proc.h> 37d66a5066SPeter Wemm #include <sys/malloc.h> 38d66a5066SPeter Wemm #include <sys/vnode.h> 39d66a5066SPeter Wemm 40d66a5066SPeter Wemm #include <i386/linux/linux_util.h> 41d66a5066SPeter Wemm 42762e6b85SEivind Eklund #include <vm/vm_zone.h> 43762e6b85SEivind Eklund 44d66a5066SPeter Wemm const char linux_emul_path[] = "/compat/linux"; 45d66a5066SPeter Wemm 46d66a5066SPeter Wemm /* 47d66a5066SPeter Wemm * Search an alternate path before passing pathname arguments on 48d66a5066SPeter Wemm * to system calls. Useful for keeping a seperate 'emulation tree'. 49d66a5066SPeter Wemm * 50d66a5066SPeter Wemm * If cflag is set, we check if an attempt can be made to create 51d66a5066SPeter Wemm * the named file, i.e. we check if the directory it should 52d66a5066SPeter Wemm * be in exists. 53d66a5066SPeter Wemm */ 54d66a5066SPeter Wemm int 55d66a5066SPeter Wemm linux_emul_find(p, sgp, prefix, path, pbuf, cflag) 56d66a5066SPeter Wemm struct proc *p; 57d66a5066SPeter Wemm caddr_t *sgp; /* Pointer to stackgap memory */ 58d66a5066SPeter Wemm const char *prefix; 59d66a5066SPeter Wemm char *path; 60d66a5066SPeter Wemm char **pbuf; 61d66a5066SPeter Wemm int cflag; 62d66a5066SPeter Wemm { 63d66a5066SPeter Wemm struct nameidata nd; 64d66a5066SPeter Wemm struct nameidata ndroot; 65d66a5066SPeter Wemm struct vattr vat; 66d66a5066SPeter Wemm struct vattr vatroot; 67d66a5066SPeter Wemm int error; 68d66a5066SPeter Wemm char *ptr, *buf, *cp; 69d66a5066SPeter Wemm size_t sz, len; 70d66a5066SPeter Wemm 71d66a5066SPeter Wemm buf = (char *) malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 72d66a5066SPeter Wemm *pbuf = path; 73d66a5066SPeter Wemm 74d66a5066SPeter Wemm for (ptr = buf; (*ptr = *prefix) != '\0'; ptr++, prefix++) 75d66a5066SPeter Wemm continue; 76d66a5066SPeter Wemm 77d66a5066SPeter Wemm sz = MAXPATHLEN - (ptr - buf); 78d66a5066SPeter Wemm 79d66a5066SPeter Wemm /* 80d66a5066SPeter Wemm * If sgp is not given then the path is already in kernel space 81d66a5066SPeter Wemm */ 82d66a5066SPeter Wemm if (sgp == NULL) 83d66a5066SPeter Wemm error = copystr(path, ptr, sz, &len); 84d66a5066SPeter Wemm else 85d66a5066SPeter Wemm error = copyinstr(path, ptr, sz, &len); 86d66a5066SPeter Wemm 87d66a5066SPeter Wemm if (error) { 88d66a5066SPeter Wemm free(buf, M_TEMP); 89d66a5066SPeter Wemm return error; 90d66a5066SPeter Wemm } 91d66a5066SPeter Wemm 92d66a5066SPeter Wemm if (*ptr != '/') { 93d66a5066SPeter Wemm free(buf, M_TEMP); 94d66a5066SPeter Wemm return EINVAL; 95d66a5066SPeter Wemm } 96d66a5066SPeter Wemm 97d66a5066SPeter Wemm /* 98d66a5066SPeter Wemm * We know that there is a / somewhere in this pathname. 99d66a5066SPeter Wemm * Search backwards for it, to find the file's parent dir 100d66a5066SPeter Wemm * to see if it exists in the alternate tree. If it does, 101d66a5066SPeter Wemm * and we want to create a file (cflag is set). We don't 102d66a5066SPeter Wemm * need to worry about the root comparison in this case. 103d66a5066SPeter Wemm */ 104d66a5066SPeter Wemm 105d66a5066SPeter Wemm if (cflag) { 106d66a5066SPeter Wemm for (cp = &ptr[len] - 1; *cp != '/'; cp--); 107d66a5066SPeter Wemm *cp = '\0'; 108d66a5066SPeter Wemm 109d66a5066SPeter Wemm NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, buf, p); 110d66a5066SPeter Wemm 111d66a5066SPeter Wemm if ((error = namei(&nd)) != 0) { 112d66a5066SPeter Wemm free(buf, M_TEMP); 113d66a5066SPeter Wemm return error; 114d66a5066SPeter Wemm } 115d66a5066SPeter Wemm 116d66a5066SPeter Wemm *cp = '/'; 117d66a5066SPeter Wemm } 118d66a5066SPeter Wemm else { 119d66a5066SPeter Wemm NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, buf, p); 120d66a5066SPeter Wemm 121d66a5066SPeter Wemm if ((error = namei(&nd)) != 0) { 122d66a5066SPeter Wemm free(buf, M_TEMP); 123d66a5066SPeter Wemm return error; 124d66a5066SPeter Wemm } 125d66a5066SPeter Wemm 126d66a5066SPeter Wemm /* 127d66a5066SPeter Wemm * We now compare the vnode of the linux_root to the one 128d66a5066SPeter Wemm * vnode asked. If they resolve to be the same, then we 129d66a5066SPeter Wemm * ignore the match so that the real root gets used. 130d66a5066SPeter Wemm * This avoids the problem of traversing "../.." to find the 131d66a5066SPeter Wemm * root directory and never finding it, because "/" resolves 132d66a5066SPeter Wemm * to the emulation root directory. This is expensive :-( 133d66a5066SPeter Wemm */ 1346bce784dSBruce Evans NDINIT(&ndroot, LOOKUP, FOLLOW, UIO_SYSSPACE, linux_emul_path, 1356bce784dSBruce Evans p); 136d66a5066SPeter Wemm 137d66a5066SPeter Wemm if ((error = namei(&ndroot)) != 0) { 138d66a5066SPeter Wemm /* Cannot happen! */ 139d66a5066SPeter Wemm free(buf, M_TEMP); 140762e6b85SEivind Eklund NDFREE(&nd, NDF_ONLY_PNBUF); 141d66a5066SPeter Wemm vrele(nd.ni_vp); 142d66a5066SPeter Wemm return error; 143d66a5066SPeter Wemm } 144d66a5066SPeter Wemm 145d66a5066SPeter Wemm if ((error = VOP_GETATTR(nd.ni_vp, &vat, p->p_ucred, p)) != 0) { 146d0dc9fdbSNate Williams goto bad; 147d66a5066SPeter Wemm } 148d66a5066SPeter Wemm 149d66a5066SPeter Wemm if ((error = VOP_GETATTR(ndroot.ni_vp, &vatroot, p->p_ucred, p)) 150d66a5066SPeter Wemm != 0) { 151d0dc9fdbSNate Williams goto bad; 152d66a5066SPeter Wemm } 153d66a5066SPeter Wemm 154d66a5066SPeter Wemm if (vat.va_fsid == vatroot.va_fsid && 155d66a5066SPeter Wemm vat.va_fileid == vatroot.va_fileid) { 156d66a5066SPeter Wemm error = ENOENT; 157d0dc9fdbSNate Williams goto bad; 158d66a5066SPeter Wemm } 159d66a5066SPeter Wemm 160d66a5066SPeter Wemm } 161d66a5066SPeter Wemm if (sgp == NULL) 162d66a5066SPeter Wemm *pbuf = buf; 163d66a5066SPeter Wemm else { 164d66a5066SPeter Wemm sz = &ptr[len] - buf; 165d66a5066SPeter Wemm *pbuf = stackgap_alloc(sgp, sz + 1); 166d66a5066SPeter Wemm error = copyout(buf, *pbuf, sz); 167d66a5066SPeter Wemm free(buf, M_TEMP); 168d66a5066SPeter Wemm } 169d66a5066SPeter Wemm 170762e6b85SEivind Eklund NDFREE(&nd, NDF_ONLY_PNBUF); 171d66a5066SPeter Wemm vrele(nd.ni_vp); 172762e6b85SEivind Eklund if (!cflag) { 173762e6b85SEivind Eklund NDFREE(&ndroot, NDF_ONLY_PNBUF); 174d66a5066SPeter Wemm vrele(ndroot.ni_vp); 175762e6b85SEivind Eklund } 176d66a5066SPeter Wemm return error; 177d0dc9fdbSNate Williams 178d0dc9fdbSNate Williams bad: 179762e6b85SEivind Eklund NDFREE(&ndroot, NDF_ONLY_PNBUF); 180d0dc9fdbSNate Williams vrele(ndroot.ni_vp); 181762e6b85SEivind Eklund NDFREE(&nd, NDF_ONLY_PNBUF); 182d0dc9fdbSNate Williams vrele(nd.ni_vp); 183d0dc9fdbSNate Williams free(buf, M_TEMP); 184d0dc9fdbSNate Williams return error; 185d66a5066SPeter Wemm } 186