gen/FreeBSD/exec.c

   1 /*-
   2  * Copyright (c) 1991, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #if defined(LIBC_SCCS) && !defined(lint)
  35 static char sccsid[] = "@(#)exec.c      8.1 (Berkeley) 6/4/93";
  36 #endif /* LIBC_SCCS and not lint */
  37 #include <sys/cdefs.h>
  38 __FBSDID("$FreeBSD: src/lib/libc/gen/exec.c,v 1.20 2003/01/03 23:16:55 tjr Exp $");
  39
  40 #include "namespace.h"
  41 #include <sys/param.h>
  42 #include <sys/types.h>
  43 #include <sys/stat.h>
  44 #include <errno.h>
  45 #include <unistd.h>
  46 #include <stdlib.h>
  47 #include <string.h>
  48 #include <stdio.h>
  49 #include <paths.h>
  50
  51 #include <stdarg.h>
  52 #include "un-namespace.h"
  53
  54 extern char **environ;
  55
  56 int
  57 execl(const char *name, const char *arg, ...)
  58 {
  59         va_list ap;
  60         char **argv;
  61         int n;
  62
  63         va_start(ap, arg);
  64         n = 1;
  65         while (va_arg(ap, char *) != NULL)
  66                 n++;
  67         va_end(ap);
  68         argv = alloca((n + 1) * sizeof(*argv));
  69         if (argv == NULL) {
  70                 errno = ENOMEM;
  71                 return (-1);
  72         }
  73         va_start(ap, arg);
  74         n = 1;
  75         argv[0] = (char *)arg;
  76         while ((argv[n] = va_arg(ap, char *)) != NULL)
  77                 n++;
  78         va_end(ap);
  79         return (_execve(name, argv, environ));
  80 }
  81
  82 int
  83 execle(const char *name, const char *arg, ...)
  84 {
  85         va_list ap;
  86         char **argv, **envp;
  87         int n;
  88
  89         va_start(ap, arg);
  90         n = 1;
  91         while (va_arg(ap, char *) != NULL)
  92                 n++;
  93         va_end(ap);
  94         argv = alloca((n + 1) * sizeof(*argv));
  95         if (argv == NULL) {
  96                 errno = ENOMEM;
  97                 return (-1);
  98         }
  99         va_start(ap, arg);
 100         n = 1;
 101         argv[0] = (char *)arg;
 102         while ((argv[n] = va_arg(ap, char *)) != NULL)
 103                 n++;
 104         envp = va_arg(ap, char **);
 105         va_end(ap);
 106         return (_execve(name, argv, envp));
 107 }
 108
 109 int
 110 execlp(const char *name, const char *arg, ...)
 111 {
 112         va_list ap;
 113         char **argv;
 114         int n;
 115
 116         va_start(ap, arg);
 117         n = 1;
 118         while (va_arg(ap, char *) != NULL)
 119                 n++;
 120         va_end(ap);
 121         argv = alloca((n + 1) * sizeof(*argv));
 122         if (argv == NULL) {
 123                 errno = ENOMEM;
 124                 return (-1);
 125         }
 126         va_start(ap, arg);
 127         n = 1;
 128         argv[0] = (char *)arg;
 129         while ((argv[n] = va_arg(ap, char *)) != NULL)
 130                 n++;
 131         va_end(ap);
 132         return (execvp(name, argv));
 133 }
 134
 135 int
 136 execv(name, argv)
 137         const char *name;
 138         char * const *argv;
 139 {
 140         (void)_execve(name, argv, environ);
 141         return (-1);
 142 }
 143
 144 int
 145 execvp(name, argv)
 146         const char *name;
 147         char * const *argv;
 148 {
 149         char **memp;
 150         int cnt, lp, ln;
 151         char *p;
 152         int eacces, save_errno;
 153         char *bp, *cur, *path, buf[MAXPATHLEN];
 154         struct stat sb;
 155
 156         eacces = 0;
 157
 158         /* If it's an absolute or relative path name, it's easy. */
 159         if (index(name, '/')) {
 160                 bp = (char *)name;
 161                 cur = path = NULL;
 162                 goto retry;
 163         }
 164         bp = buf;
 165
 166         /* If it's an empty path name, fail in the usual POSIX way. */
 167         if (*name == '\0') {
 168                 errno = ENOENT;
 169                 return (-1);
 170         }
 171
 172         /* Get the path we're searching. */
 173         if (!(path = getenv("PATH")))
 174                 path = _PATH_DEFPATH;
 175         cur = alloca(strlen(path) + 1);
 176         if (cur == NULL) {
 177                 errno = ENOMEM;
 178                 return (-1);
 179         }
 180         strcpy(cur, path);
 181         path = cur;
 182         while ( (p = strsep(&cur, ":")) ) {
 183                 /*
 184                  * It's a SHELL path -- double, leading and trailing colons
 185                  * mean the current directory.
 186                  */
 187                 if (!*p) {
 188                         p = ".";
 189                         lp = 1;
 190                 } else
 191                         lp = strlen(p);
 192                 ln = strlen(name);
 193
 194                 /*
 195                  * If the path is too long complain.  This is a possible
 196                  * security issue; given a way to make the path too long
 197                  * the user may execute the wrong program.
 198                  */
 199                 if (lp + ln + 2 > sizeof(buf)) {
 200                         (void)_write(STDERR_FILENO, "execvp: ", 8);
 201                         (void)_write(STDERR_FILENO, p, lp);
 202                         (void)_write(STDERR_FILENO, ": path too long\n",
 203                             16);
 204                         continue;
 205                 }
 206                 bcopy(p, buf, lp);
 207                 buf[lp] = '/';
 208                 bcopy(name, buf + lp + 1, ln);
 209                 buf[lp + ln + 1] = '\0';
 210
 211 retry:          (void)_execve(bp, argv, environ);
 212                 switch(errno) {
 213                 case E2BIG:
 214                         goto done;
 215                 case ELOOP:
 216                 case ENAMETOOLONG:
 217                 case ENOENT:
 218                         break;
 219                 case ENOEXEC:
 220                         for (cnt = 0; argv[cnt]; ++cnt)
 221                                 ;
 222                         memp = alloca((cnt + 2) * sizeof(char *));
 223                         if (memp == NULL) {
 224                                 /* errno = ENOMEM; XXX override ENOEXEC? */
 225                                 goto done;
 226                         }
 227                         memp[0] = "sh";
 228                         memp[1] = bp;
 229                         bcopy(argv + 1, memp + 2, cnt * sizeof(char *));
 230                         (void)_execve(_PATH_BSHELL, memp, environ);
 231                         goto done;
 232                 case ENOMEM:
 233                         goto done;
 234                 case ENOTDIR:
 235                         break;
 236                 case ETXTBSY:
 237                         /*
 238                          * We used to retry here, but sh(1) doesn't.
 239                          */
 240                         goto done;
 241                 default:
 242                         /*
 243                          * EACCES may be for an inaccessible directory or
 244                          * a non-executable file.  Call stat() to decide
 245                          * which.  This also handles ambiguities for EFAULT
 246                          * and EIO, and undocumented errors like ESTALE.
 247                          * We hope that the race for a stat() is unimportant.
 248                          */
 249                         save_errno = errno;
 250                         if (stat(bp, &sb) != 0)
 251                                 break;
 252                         if (save_errno == EACCES) {
 253                                 eacces = 1;
 254                                 continue;
 255                         }
 256                         errno = save_errno;
 257                         goto done;
 258                 }
 259         }
 260         if (eacces)
 261                 errno = EACCES;
 262         else
 263                 errno = ENOENT;
 264 done:
 265         return (-1);
 266 }