compat_util.c revision 1.8
1 /* $NetBSD: compat_util.c,v 1.8 1998/09/05 14:50:25 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 1994 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Christos Zoulas. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 /* 40 * Copyright (c) 1995 Frank van der Linden 41 * All rights reserved. 42 * 43 * Redistribution and use in source and binary forms, with or without 44 * modification, are permitted provided that the following conditions 45 * are met: 46 * 1. Redistributions of source code must retain the above copyright 47 * notice, this list of conditions and the following disclaimer. 48 * 2. Redistributions in binary form must reproduce the above copyright 49 * notice, this list of conditions and the following disclaimer in the 50 * documentation and/or other materials provided with the distribution. 51 * 3. The name of the author may not be used to endorse or promote products 52 * derived from this software without specific prior written permission 53 * 54 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 55 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 56 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 57 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 58 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 59 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 60 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 61 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 62 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 63 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 64 * 65 */ 66 67 #include <sys/param.h> 68 #include <sys/systm.h> 69 #include <sys/namei.h> 70 #include <sys/proc.h> 71 #include <sys/file.h> 72 #include <sys/stat.h> 73 #include <sys/filedesc.h> 74 #include <sys/exec.h> 75 #include <sys/ioctl.h> 76 #include <sys/kernel.h> 77 #include <sys/malloc.h> 78 #include <sys/vnode.h> 79 #include <sys/syslog.h> 80 #include <sys/mount.h> 81 82 #include <vm/vm_param.h> 83 84 #include <compat/common/compat_util.h> 85 86 /* 87 * Search an alternate path before passing pathname arguments on 88 * to system calls. Useful for keeping a separate 'emulation tree'. 89 * 90 * If cflag is set, we check if an attempt can be made to create 91 * the named file, i.e. we check if the directory it should 92 * be in exists. 93 */ 94 int 95 emul_find(p, sgp, prefix, path, pbuf, cflag) 96 struct proc *p; 97 caddr_t *sgp; /* Pointer to stackgap memory */ 98 const char *prefix; 99 char *path; 100 char **pbuf; 101 int cflag; 102 { 103 struct nameidata nd; 104 struct nameidata ndroot; 105 struct vattr vat; 106 struct vattr vatroot; 107 int error; 108 char *ptr, *buf, *cp; 109 const char *pr; 110 size_t sz, len; 111 112 buf = (char *) malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 113 *pbuf = path; 114 115 for (ptr = buf, pr = prefix; (*ptr = *pr) != '\0'; ptr++, pr++) 116 continue; 117 118 sz = MAXPATHLEN - (ptr - buf); 119 120 /* 121 * If sgp is not given then the path is already in kernel space 122 */ 123 if (sgp == NULL) 124 error = copystr(path, ptr, sz, &len); 125 else 126 error = copyinstr(path, ptr, sz, &len); 127 128 if (error) 129 goto bad; 130 131 if (*ptr != '/') { 132 error = EINVAL; 133 goto bad; 134 } 135 136 /* 137 * We know that there is a / somewhere in this pathname. 138 * Search backwards for it, to find the file's parent dir 139 * to see if it exists in the alternate tree. If it does, 140 * and we want to create a file (cflag is set). We don't 141 * need to worry about the root comparison in this case. 142 */ 143 144 if (cflag) { 145 for (cp = &ptr[len] - 1; *cp != '/'; cp--) 146 ; 147 *cp = '\0'; 148 149 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, buf, p); 150 151 if ((error = namei(&nd)) != 0) 152 goto bad; 153 154 *cp = '/'; 155 } 156 else { 157 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, buf, p); 158 159 if ((error = namei(&nd)) != 0) 160 goto bad; 161 162 /* 163 * We now compare the vnode of the emulation root to the one 164 * vnode asked. If they resolve to be the same, then we 165 * ignore the match so that the real root gets used. 166 * This avoids the problem of traversing "../.." to find the 167 * root directory and never finding it, because "/" resolves 168 * to the emulation root directory. This is expensive :-( 169 */ 170 NDINIT(&ndroot, LOOKUP, FOLLOW, UIO_SYSSPACE, prefix, p); 171 172 if ((error = namei(&ndroot)) != 0) 173 goto bad2; 174 175 if ((error = VOP_GETATTR(nd.ni_vp, &vat, p->p_ucred, p)) != 0) 176 goto bad3; 177 178 if ((error = VOP_GETATTR(ndroot.ni_vp, &vatroot, p->p_ucred, p)) 179 != 0) 180 goto bad3; 181 182 if (vat.va_fsid == vatroot.va_fsid && 183 vat.va_fileid == vatroot.va_fileid) { 184 error = ENOENT; 185 goto bad3; 186 } 187 } 188 if (sgp == NULL) 189 *pbuf = buf; 190 else { 191 sz = &ptr[len] - buf; 192 *pbuf = stackgap_alloc(sgp, sz + 1); 193 error = copyout(buf, *pbuf, sz); 194 free(buf, M_TEMP); 195 } 196 197 vrele(nd.ni_vp); 198 if (!cflag) 199 vrele(ndroot.ni_vp); 200 return error; 201 202 bad3: 203 vrele(ndroot.ni_vp); 204 bad2: 205 vrele(nd.ni_vp); 206 bad: 207 free(buf, M_TEMP); 208 return error; 209 } 210 211 caddr_t 212 stackgap_init(e) 213 struct emul *e; 214 { 215 216 #define szsigcode ((caddr_t)(e->e_esigcode - e->e_sigcode)) 217 return STACKGAPBASE; 218 #undef szsigcode 219 } 220 221 222 void * 223 stackgap_alloc(sgp, sz) 224 caddr_t *sgp; 225 size_t sz; 226 { 227 void *p = (void *) *sgp; 228 229 *sgp += ALIGN(sz); 230 return p; 231 } 232 233 void 234 compat_offseterr(vp, msg) 235 struct vnode *vp; 236 char *msg; 237 { 238 struct mount *mp; 239 240 mp = vp->v_mount; 241 242 log(LOG_ERR, "%s: dir offset too large on fs %s (mounted from %s)\n", 243 msg, mp->mnt_stat.f_mntonname, mp->mnt_stat.f_mntfromname); 244 uprintf("%s: dir offset too large for emulated program\n", msg); 245 } 246
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