gen/exec-fbsd.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 1.22 2003/07/01 12:30:03 bde 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 #include <crt_externs.h>
  55 #define environ (*_NSGetEnviron())
  56
  57 int
  58 execl(const char *name, const char *arg, ...)
  59 {
  60         va_list ap;
  61         char **argv;
  62         int n;
  63
  64         va_start(ap, arg);
  65         n = 1;
  66         while (va_arg(ap, char *) != NULL)
  67                 n++;
  68         va_end(ap);
  69         argv = alloca((n + 1) * sizeof(*argv));
  70         if (argv == NULL) {
  71                 errno = ENOMEM;
  72                 return (-1);
  73         }
  74         va_start(ap, arg);
  75         n = 1;
  76         argv[0] = (char *)arg;
  77         while ((argv[n] = va_arg(ap, char *)) != NULL)
  78                 n++;
  79         va_end(ap);
  80         return (_execve(name, argv, environ));
  81 }
  82
  83 int
  84 execle(const char *name, const char *arg, ...)
  85 {
  86         va_list ap;
  87         char **argv, **envp;
  88         int n;
  89
  90         va_start(ap, arg);
  91         n = 1;
  92         while (va_arg(ap, char *) != NULL)
  93                 n++;
  94         va_end(ap);
  95         argv = alloca((n + 1) * sizeof(*argv));
  96         if (argv == NULL) {
  97                 errno = ENOMEM;
  98                 return (-1);
  99         }
 100         va_start(ap, arg);
 101         n = 1;
 102         argv[0] = (char *)arg;
 103         while ((argv[n] = va_arg(ap, char *)) != NULL)
 104                 n++;
 105         envp = va_arg(ap, char **);
 106         va_end(ap);
 107         return (_execve(name, argv, envp));
 108 }
 109
 110 int
 111 execlp(const char *name, const char *arg, ...)
 112 {
 113         va_list ap;
 114         char **argv;
 115         int n;
 116
 117         va_start(ap, arg);
 118         n = 1;
 119         while (va_arg(ap, char *) != NULL)
 120                 n++;
 121         va_end(ap);
 122         argv = alloca((n + 1) * sizeof(*argv));
 123         if (argv == NULL) {
 124                 errno = ENOMEM;
 125                 return (-1);
 126         }
 127         va_start(ap, arg);
 128         n = 1;
 129         argv[0] = (char *)arg;
 130         while ((argv[n] = va_arg(ap, char *)) != NULL)
 131                 n++;
 132         va_end(ap);
 133         return (execvp(name, argv));
 134 }
 135
 136 int
 137 execv(name, argv)
 138         const char *name;
 139         char * const *argv;
 140 {
 141         (void)_execve(name, argv, environ);
 142         return (-1);
 143 }
 144
 145 int
 146 execvp(const char *name, char * const *argv)
 147 {
 148         const char *path;
 149
 150         /* Get the path we're searching. */
 151         if ((path = getenv("PATH")) == NULL)
 152                 path = _PATH_DEFPATH;
 153
 154         return (execvP(name, path, argv));
 155 }
 156
 157 int
 158 execvP(name, path, argv)
 159         const char *name;
 160         const char *path;
 161         char * const *argv;
 162 {
 163         char **memp;
 164         int cnt, lp, ln;
 165         char *p;
 166         int eacces, save_errno;
 167         char *bp, *cur, buf[MAXPATHLEN];
 168         struct stat sb;
 169
 170         eacces = 0;
 171
 172         /* If it's an absolute or relative path name, it's easy. */
 173         if (index(name, '/')) {
 174                 bp = (char *)name;
 175                 cur = NULL;
 176                 goto retry;
 177         }
 178         bp = buf;
 179
 180         /* If it's an empty path name, fail in the usual POSIX way. */
 181         if (*name == '\0') {
 182                 errno = ENOENT;
 183                 return (-1);
 184         }
 185
 186         cur = alloca(strlen(path) + 1);
 187         if (cur == NULL) {
 188                 errno = ENOMEM;
 189                 return (-1);
 190         }
 191         strcpy(cur, path);
 192         while ((p = strsep(&cur, ":")) != NULL) {
 193                 /*
 194                  * It's a SHELL path -- double, leading and trailing colons
 195                  * mean the current directory.
 196                  */
 197                 if (*p == '\0') {
 198                         p = ".";
 199                         lp = 1;
 200                 } else
 201                         lp = strlen(p);
 202                 ln = strlen(name);
 203
 204                 /*
 205                  * If the path is too long complain.  This is a possible
 206                  * security issue; given a way to make the path too long
 207                  * the user may execute the wrong program.
 208                  */
 209                 if (lp + ln + 2 > sizeof(buf)) {
 210                         (void)_write(STDERR_FILENO, "execvP: ", 8);
 211                         (void)_write(STDERR_FILENO, p, lp);
 212                         (void)_write(STDERR_FILENO, ": path too long\n",
 213                             16);
 214                         continue;
 215                 }
 216                 bcopy(p, buf, lp);
 217                 buf[lp] = '/';
 218                 bcopy(name, buf + lp + 1, ln);
 219                 buf[lp + ln + 1] = '\0';
 220
 221 retry:          (void)_execve(bp, argv, environ);
 222                 switch (errno) {
 223                 case E2BIG:
 224                         goto done;
 225                 case ELOOP:
 226                 case ENAMETOOLONG:
 227                 case ENOENT:
 228                         break;
 229                 case ENOEXEC:
 230                         for (cnt = 0; argv[cnt]; ++cnt)
 231                                 ;
 232                         memp = alloca((cnt + 2) * sizeof(char *));
 233                         if (memp == NULL) {
 234                                 /* errno = ENOMEM; XXX override ENOEXEC? */
 235                                 goto done;
 236                         }
 237                         memp[0] = "sh";
 238                         memp[1] = bp;
 239                         bcopy(argv + 1, memp + 2, cnt * sizeof(char *));
 240                         (void)_execve(_PATH_BSHELL, memp, environ);
 241                         goto done;
 242                 case ENOMEM:
 243                         goto done;
 244                 case ENOTDIR:
 245                         break;
 246                 case ETXTBSY:
 247                         /*
 248                          * We used to retry here, but sh(1) doesn't.
 249                          */
 250                         goto done;
 251                 default:
 252                         /*
 253                          * EACCES may be for an inaccessible directory or
 254                          * a non-executable file.  Call stat() to decide
 255                          * which.  This also handles ambiguities for EFAULT
 256                          * and EIO, and undocumented errors like ESTALE.
 257                          * We hope that the race for a stat() is unimportant.
 258                          */
 259                         save_errno = errno;
 260                         if (stat(bp, &sb) != 0)
 261                                 break;
 262                         if (save_errno == EACCES) {
 263                                 eacces = 1;
 264                                 continue;
 265                         }
 266                         errno = save_errno;
 267                         goto done;
 268                 }
 269         }
 270         if (eacces)
 271                 errno = EACCES;
 272         else if (cur)
 273                 errno = ENOENT;
 274         /* else use existing errno from _execve */
 275 done:
 276         return (-1);
 277 }