stdlib/system-fbsd.c

   1 /*
   2  * Copyright (c) 1988, 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[] = "@(#)system.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/stdlib/system.c,v 1.10 2002/03/22 21:53:10 obrien Exp $");
  39
  40 #include "namespace.h"
  41 #include <sys/types.h>
  42 #include <sys/wait.h>
  43 #include <signal.h>
  44 #include <stdlib.h>
  45 #include <stddef.h>
  46 #include <unistd.h>
  47 #include <spawn.h>
  48 #include <paths.h>
  49 #include <errno.h>
  50 #include "un-namespace.h"
  51 #include "libc_private.h"
  52
  53 #include <crt_externs.h>
  54 #define environ (*_NSGetEnviron())
  55
  56 #if __DARWIN_UNIX03
  57 #include <pthread.h>
  58
  59 static pthread_mutex_t __systemfn_mutex = PTHREAD_MUTEX_INITIALIZER;
  60 extern int __unix_conforming;
  61 #ifdef VARIANT_CANCELABLE
  62 extern void _pthread_testcancel(pthread_t thread, int isconforming);
  63 #endif /* VARIANT_CANCELABLE */
  64 #endif /* __DARWIN_UNIX03 */
  65
  66 int
  67 __system(command)
  68         const char *command;
  69 {
  70         pid_t pid, savedpid;
  71         int pstat, err;
  72         struct sigaction ign, intact, quitact;
  73         sigset_t newsigblock, oldsigblock, defaultsig;
  74         posix_spawnattr_t attr;
  75         short flags = POSIX_SPAWN_SETSIGMASK;
  76         const char *argv[] = {"sh", "-c", command, NULL};
  77
  78 #if __DARWIN_UNIX03
  79         if (__unix_conforming == 0)
  80                 __unix_conforming = 1;
  81 #ifdef VARIANT_CANCELABLE
  82         _pthread_testcancel(pthread_self(), 1);
  83 #endif /* VARIANT_CANCELABLE */
  84 #endif /* __DARWIN_UNIX03 */
  85
  86         if (!command) {         /* just checking... */
  87                 if (access(_PATH_BSHELL, F_OK) == -1)   /* if no sh or no access */
  88                         return(0);
  89                 else
  90                         return(1);
  91         }
  92
  93         if ((err = posix_spawnattr_init(&attr)) != 0) {
  94                 errno = err;
  95                 return -1;
  96         }
  97         (void)sigemptyset(&defaultsig);
  98
  99 #if __DARWIN_UNIX03
 100         pthread_mutex_lock(&__systemfn_mutex);
 101 #endif /* __DARWIN_UNIX03 */
 102         /*
 103          * Ignore SIGINT and SIGQUIT, block SIGCHLD. Remember to save
 104          * existing signal dispositions.
 105          */
 106         ign.sa_handler = SIG_IGN;
 107         (void)sigemptyset(&ign.sa_mask);
 108         ign.sa_flags = 0;
 109         (void)_sigaction(SIGINT, &ign, &intact);
 110         if (intact.sa_handler != SIG_IGN) {
 111                 sigaddset(&defaultsig, SIGINT);
 112                 flags |= POSIX_SPAWN_SETSIGDEF;
 113         }
 114         (void)_sigaction(SIGQUIT, &ign, &quitact);
 115         if (quitact.sa_handler != SIG_IGN) {
 116                 sigaddset(&defaultsig, SIGQUIT);
 117                 flags |= POSIX_SPAWN_SETSIGDEF;
 118         }
 119         (void)sigemptyset(&newsigblock);
 120         (void)sigaddset(&newsigblock, SIGCHLD);
 121         (void)_sigprocmask(SIG_BLOCK, &newsigblock, &oldsigblock);
 122         (void)posix_spawnattr_setsigmask(&attr, &oldsigblock);
 123         if (flags & POSIX_SPAWN_SETSIGDEF) {
 124                 (void)posix_spawnattr_setsigdefault(&attr, &defaultsig);
 125         }
 126         (void)posix_spawnattr_setflags(&attr, flags);
 127
 128         err = posix_spawn(&pid, _PATH_BSHELL, NULL, &attr, (char *const *)argv, environ);
 129         (void)posix_spawnattr_destroy(&attr);
 130         if (err == 0) {
 131                 savedpid = pid;
 132                 do {
 133                         pid = _wait4(savedpid, &pstat, 0, (struct rusage *)0);
 134                 } while (pid == -1 && errno == EINTR);
 135                 if (pid == -1) pstat = -1;
 136         } else if (err == ENOMEM || err == EAGAIN) { /* as if fork failed */
 137                 pstat = -1;
 138         } else {
 139                 pstat = W_EXITCODE(127, 0); /* couldn't exec shell */
 140         }
 141
 142         (void)_sigaction(SIGINT, &intact, NULL);
 143         (void)_sigaction(SIGQUIT,  &quitact, NULL);
 144         (void)_sigprocmask(SIG_SETMASK, &oldsigblock, NULL);
 145 #if __DARWIN_UNIX03
 146         pthread_mutex_unlock(&__systemfn_mutex);
 147 #endif /* __DARWIN_UNIX03 */
 148         return(pstat);
 149 }
 150
 151 __weak_reference(__system, system);
 152 __weak_reference(__system, _system);