sys/compat/common/compat_util.c

   1 /*      $NetBSD: compat_util.c,v 1.42 2009/06/29 05:08:15 dholland 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 and Frank van der Linden.
   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  *
  19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  29  * POSSIBILITY OF SUCH DAMAGE.
  30  */
  31
  32 /*
  33  * Copyright (c) 2008, 2009 Matthew R. Green
  34  * All rights reserved.
  35  *
  36  * Redistribution and use in source and binary forms, with or without
  37  * modification, are permitted provided that the following conditions
  38  * are met:
  39  * 1. Redistributions of source code must retain the above copyright
  40  *    notice, this list of conditions and the following disclaimer.
  41  * 2. Redistributions in binary form must reproduce the above copyright
  42  *    notice, this list of conditions and the following disclaimer in the
  43  *    documentation and/or other materials provided with the distribution.
  44  * 3. The name of the author may not be used to endorse or promote products
  45  *    derived from this software without specific prior written permission.
  46  *
  47  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  48  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  49  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  50  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  51  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  52  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  53  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  54  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  55  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  56  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  57  * SUCH DAMAGE.
  58  */
  59
  60 #include <sys/cdefs.h>
  61 __KERNEL_RCSID(0, "$NetBSD: compat_util.c,v 1.42 2009/06/29 05:08:15 dholland Exp $");
  62
  63 #include <sys/param.h>
  64 #include <sys/systm.h>
  65 #include <sys/namei.h>
  66 #include <sys/proc.h>
  67 #include <sys/file.h>
  68 #include <sys/stat.h>
  69 #include <sys/filedesc.h>
  70 #include <sys/exec.h>
  71 #include <sys/ioctl.h>
  72 #include <sys/kernel.h>
  73 #include <sys/malloc.h>
  74 #include <sys/vnode.h>
  75 #include <sys/syslog.h>
  76 #include <sys/mount.h>
  77
  78 #include <compat/common/compat_util.h>
  79
  80 void
  81 emul_find_root(struct lwp *l, struct exec_package *epp)
  82 {
  83         struct vnode *vp;
  84         const char *emul_path;
  85
  86         if (epp->ep_emul_root != NULL)
  87                 /* We've already found it */
  88                 return;
  89
  90         emul_path = epp->ep_esch->es_emul->e_path;
  91         if (emul_path == NULL)
  92                 /* Emulation doesn't have a root */
  93                 return;
  94
  95         if (namei_simple_kernel(emul_path, NSM_FOLLOW_NOEMULROOT, &vp) != 0)
  96                 /* emulation root doesn't exist */
  97                 return;
  98
  99         epp->ep_emul_root = vp;
 100 }
 101
 102 /*
 103  * Search the alternate path for dynamic binary interpreter. If not found
 104  * there, check if the interpreter exists in within 'proper' tree.
 105  */
 106 int
 107 emul_find_interp(struct lwp *l, struct exec_package *epp, const char *itp)
 108 {
 109         int error;
 110         struct nameidata nd;
 111         unsigned int flags;
 112
 113         /* If we haven't found the emulation root already, do so now */
 114         /* Maybe we should remember failures somehow ? */
 115         if (epp->ep_esch->es_emul->e_path != 0 && epp->ep_emul_root == NULL)
 116                 emul_find_root(l, epp);
 117
 118         if (epp->ep_interp != NULL)
 119                 vrele(epp->ep_interp);
 120
 121         /* We need to use the emulation root for the new program,
 122          * not the one for the current process. */
 123         if (epp->ep_emul_root == NULL)
 124                 flags = FOLLOW;
 125         else {
 126                 nd.ni_erootdir = epp->ep_emul_root;
 127                 /* hack: Pass in the emulation path for ktrace calls */
 128                 nd.ni_next = epp->ep_esch->es_emul->e_path;
 129                 flags = FOLLOW | TRYEMULROOT | EMULROOTSET;
 130         }
 131
 132         NDINIT(&nd, LOOKUP, flags, UIO_SYSSPACE, itp);
 133         error = namei(&nd);
 134         if (error != 0) {
 135                 epp->ep_interp = NULL;
 136                 return error;
 137         }
 138
 139         /* Save interpreter in case we actually need to load it */
 140         epp->ep_interp = nd.ni_vp;
 141
 142         return 0;
 143 }
 144
 145 /*
 146  * Translate one set of flags to another, based on the entries in
 147  * the given table.  If 'leftover' is specified, it is filled in
 148  * with any flags which could not be translated.
 149  */
 150 unsigned long
 151 emul_flags_translate(const struct emul_flags_xtab *tab,
 152                      unsigned long in, unsigned long *leftover)
 153 {
 154         unsigned long out;
 155
 156         for (out = 0; tab->omask != 0; tab++) {
 157                 if ((in & tab->omask) == tab->oval) {
 158                         in &= ~tab->omask;
 159                         out |= tab->nval;
 160                 }
 161         }
 162         if (leftover != NULL)
 163                 *leftover = in;
 164         return (out);
 165 }
 166
 167 void
 168 compat_offseterr(struct vnode *vp, const char *msg)
 169 {
 170         struct mount *mp;
 171
 172         mp = vp->v_mount;
 173
 174         log(LOG_ERR, "%s: dir offset too large on fs %s (mounted from %s)\n",
 175             msg, mp->mnt_stat.f_mntonname, mp->mnt_stat.f_mntfromname);
 176         uprintf("%s: dir offset too large for emulated program\n", msg);
 177 }
 178
 179 /*
 180  * Look for native NetBSD compatibility libraries, usually interp-ABI.
 181  * It returns 0 if it changed the interpreter, otherwise it returns
 182  * the error from namei().  Callers should not try any more processing
 183  * if this returns 0, and probably should just ignore the return value.
 184  */
 185 int
 186 compat_elf_check_interp(struct exec_package *epp,
 187                         char *interp,
 188                         const char *interp_suffix)
 189 {
 190         int error = 0;
 191
 192         /*
 193          * Don't look for something else, if someone has already found and
 194          * setup the ep_interp already.
 195          */
 196         if (interp && epp->ep_interp == NULL) {
 197                 /*
 198                  * If the path is exactly "/usr/libexec/ld.elf_so", first
 199                  * try to see if "/usr/libexec/ld.elf_so-<abi>" exists
 200                  * and if so, use that instead.
 201                  */
 202                 if (strcmp(interp, "/usr/libexec/ld.elf_so") == 0 ||
 203                     strcmp(interp, "/libexec/ld.elf_so") == 0) {
 204                         struct vnode *vp;
 205                         char *path;
 206
 207                         path = PNBUF_GET();
 208                         snprintf(path, MAXPATHLEN, "%s-%s", interp, interp_suffix);
 209                         error = namei_simple_kernel(path,
 210                                         NSM_FOLLOW_NOEMULROOT, &vp);
 211                         /*
 212                          * If that worked, replace interpreter in case we
 213                          * actually need to load it.
 214                          */
 215                         if (error == 0) {
 216                                 epp->ep_interp = vp;
 217                                 snprintf(interp, MAXPATHLEN, "%s", path);
 218                         }
 219                         PNBUF_PUT(path);
 220                 }
 221         }
 222         return error;
 223 }