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  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 #if defined(LIBC_SCCS) && !defined(lint)
  31 static char sccsid[] = "@(#)exec.c      8.1 (Berkeley) 6/4/93";
  32 #endif /* LIBC_SCCS and not lint */
  33 #include <sys/cdefs.h>
  34 __FBSDID("$FreeBSD: src/lib/libc/gen/exec.c,v 1.27 2009/12/05 18:55:16 ed Exp $");
  35
  36 #include "namespace.h"
  37 #include <sys/param.h>
  38 #include <sys/types.h>
  39 #include <sys/stat.h>
  40 #include <errno.h>
  41 #include <unistd.h>
  42 #include <stdlib.h>
  43 #include <string.h>
  44 #include <stdio.h>
  45 #include <paths.h>
  46
  47 #include <stdarg.h>
  48 #include "un-namespace.h"
  49 #include "libc_private.h"
  50
  51 #include <crt_externs.h>
  52 #define environ (*_NSGetEnviron())
  53
  54 int
  55 _execvpe(const char *name, char * const argv[], char * const envp[]);
  56
  57 int
  58 execl(const char *name, const char *arg, ...)
  59 {
  60         va_list ap;
  61         const 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] = arg;
  77         while ((argv[n] = va_arg(ap, char *)) != NULL)
  78                 n++;
  79         va_end(ap);
  80         return (_execve(name, __DECONST(char **, argv), environ));
  81 }
  82
  83 int
  84 execle(const char *name, const char *arg, ...)
  85 {
  86         va_list ap;
  87         const char **argv;
  88         char **envp;
  89         int n;
  90
  91         va_start(ap, arg);
  92         n = 1;
  93         while (va_arg(ap, char *) != NULL)
  94                 n++;
  95         va_end(ap);
  96         argv = alloca((n + 1) * sizeof(*argv));
  97         if (argv == NULL) {
  98                 errno = ENOMEM;
  99                 return (-1);
 100         }
 101         va_start(ap, arg);
 102         n = 1;
 103         argv[0] = arg;
 104         while ((argv[n] = va_arg(ap, char *)) != NULL)
 105                 n++;
 106         envp = va_arg(ap, char **);
 107         va_end(ap);
 108         return (_execve(name, __DECONST(char **, argv), envp));
 109 }
 110
 111 int
 112 execlp(const char *name, const char *arg, ...)
 113 {
 114         va_list ap;
 115         const char **argv;
 116         int n;
 117
 118         va_start(ap, arg);
 119         n = 1;
 120         while (va_arg(ap, char *) != NULL)
 121                 n++;
 122         va_end(ap);
 123         argv = alloca((n + 1) * sizeof(*argv));
 124         if (argv == NULL) {
 125                 errno = ENOMEM;
 126                 return (-1);
 127         }
 128         va_start(ap, arg);
 129         n = 1;
 130         argv[0] = arg;
 131         while ((argv[n] = va_arg(ap, char *)) != NULL)
 132                 n++;
 133         va_end(ap);
 134         return (execvp(name, __DECONST(char **, argv)));
 135 }
 136
 137 int
 138 execv(name, argv)
 139         const char *name;
 140         char * const *argv;
 141 {
 142         (void)_execve(name, argv, environ);
 143         return (-1);
 144 }
 145
 146 int
 147 execvp(const char *name, char * const *argv)
 148 {
 149         return (_execvpe(name, argv, environ));
 150 }
 151
 152 static int
 153 execvPe(const char *name, const char *path, char * const *argv,
 154     char * const *envp)
 155 {
 156         const char **memp;
 157         size_t cnt, lp, ln;
 158         int eacces, save_errno;
 159         char *cur, buf[MAXPATHLEN];
 160         const char *p, *bp;
 161         struct stat sb;
 162
 163         eacces = 0;
 164
 165         /* If it's an absolute or relative path name, it's easy. */
 166         if (index(name, '/')) {
 167                 bp = name;
 168                 cur = NULL;
 169                 goto retry;
 170         }
 171         bp = buf;
 172
 173         /* If it's an empty path name, fail in the usual POSIX way. */
 174         if (*name == '\0') {
 175                 errno = ENOENT;
 176                 return (-1);
 177         }
 178
 179         cur = alloca(strlen(path) + 1);
 180         if (cur == NULL) {
 181                 errno = ENOMEM;
 182                 return (-1);
 183         }
 184         strcpy(cur, path);
 185         while ((p = strsep(&cur, ":")) != NULL) {
 186                 /*
 187                  * It's a SHELL path -- double, leading and trailing colons
 188                  * mean the current directory.
 189                  */
 190                 if (*p == '\0') {
 191                         p = ".";
 192                         lp = 1;
 193                 } else
 194                         lp = strlen(p);
 195                 ln = strlen(name);
 196
 197                 /*
 198                  * If the path is too long complain.  This is a possible
 199                  * security issue; given a way to make the path too long
 200                  * the user may execute the wrong program.
 201                  */
 202                 if (lp + ln + 2 > sizeof(buf)) {
 203                         (void)_write(STDERR_FILENO, "execvP: ", 8);
 204                         (void)_write(STDERR_FILENO, p, lp);
 205                         (void)_write(STDERR_FILENO, ": path too long\n",
 206                             16);
 207                         continue;
 208                 }
 209                 bcopy(p, buf, lp);
 210                 buf[lp] = '/';
 211                 bcopy(name, buf + lp + 1, ln);
 212                 buf[lp + ln + 1] = '\0';
 213
 214 retry:          (void)_execve(bp, argv, envp);
 215                 switch (errno) {
 216                 case E2BIG:
 217                         goto done;
 218                 case ELOOP:
 219                 case ENAMETOOLONG:
 220                 case ENOENT:
 221                         break;
 222                 case ENOEXEC:
 223                         for (cnt = 0; argv[cnt]; ++cnt)
 224                                 ;
 225                         memp = alloca((cnt + 2) * sizeof(char *));
 226                         if (memp == NULL) {
 227                                 /* errno = ENOMEM; XXX override ENOEXEC? */
 228                                 goto done;
 229                         }
 230                         memp[0] = "sh";
 231                         memp[1] = bp;
 232                         bcopy(argv + 1, memp + 2, cnt * sizeof(char *));
 233                         (void)_execve(_PATH_BSHELL,
 234                             __DECONST(char **, memp), envp);
 235                         goto done;
 236                 case ENOMEM:
 237                         goto done;
 238                 case ENOTDIR:
 239                         break;
 240                 case ETXTBSY:
 241                         /*
 242                          * We used to retry here, but sh(1) doesn't.
 243                          */
 244                         goto done;
 245                 default:
 246                         /*
 247                          * EACCES may be for an inaccessible directory or
 248                          * a non-executable file.  Call stat() to decide
 249                          * which.  This also handles ambiguities for EFAULT
 250                          * and EIO, and undocumented errors like ESTALE.
 251                          * We hope that the race for a stat() is unimportant.
 252                          */
 253                         save_errno = errno;
 254                         if (stat(bp, &sb) != 0)
 255                                 break;
 256                         if (save_errno == EACCES) {
 257                                 eacces = 1;
 258                                 continue;
 259                         }
 260                         errno = save_errno;
 261                         goto done;
 262                 }
 263         }
 264         if (eacces)
 265                 errno = EACCES;
 266         else if (cur)
 267                 errno = ENOENT;
 268         /* else use existing errno from _execve */
 269 done:
 270         return (-1);
 271 }
 272
 273 int
 274 execvP(const char *name, const char *path, char * const argv[])
 275 {
 276         return execvPe(name, path, argv, environ);
 277 }
 278
 279 __private_extern__ int
 280 _execvpe(const char *name, char * const argv[], char * const envp[])
 281 {
 282         const char *path;
 283
 284         /* Get the path we're searching. */
 285         if ((path = getenv("PATH")) == NULL)
 286                 path = _PATH_DEFPATH;
 287
 288         return (execvPe(name, path, argv, envp));
 289 }