contrib/libarchive-2.1/libarchive/filter_fork.c

   1 /*-
   2  * Copyright (c) 2007 Joerg Sonnenberger
   3  * 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  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
  15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  17  * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
  18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #include "archive_platform.h"
  27
  28 __FBSDID("$FreeBSD$");
  29
  30 #if defined(HAVE_POLL)
  31 #  if defined(HAVE_POLL_H)
  32 #    include <poll.h>
  33 #  endif
  34 #elif defined(HAVE_SELECT)
  35 #  if defined(HAVE_SYS_SELECT_H)
  36 #    include <sys/select.h>
  37 #  elif defined(HAVE_UNISTD_H)
  38 #    include <unistd.h>
  39 #  endif
  40 #endif
  41 #ifdef HAVE_FCNTL_H
  42 #  include <fcntl.h>
  43 #endif
  44 #ifdef HAVE_UNISTD_H
  45 #  include <unistd.h>
  46 #endif
  47
  48 #include "filter_fork.h"
  49
  50 pid_t
  51 __archive_create_child(const char *path, int *child_stdin, int *child_stdout)
  52 {
  53         pid_t child;
  54         int stdin_pipe[2], stdout_pipe[2], tmp;
  55
  56         if (pipe(stdin_pipe) == -1)
  57                 goto state_allocated;
  58         if (stdin_pipe[0] == STDOUT_FILENO) {
  59                 if ((tmp = dup(stdin_pipe[0])) == -1)
  60                         goto stdin_opened;
  61                 close(stdin_pipe[0]);
  62                 stdin_pipe[0] = tmp;
  63         }
  64         if (pipe(stdout_pipe) == -1)
  65                 goto stdin_opened;
  66         if (stdout_pipe[1] == STDIN_FILENO) {
  67                 if ((tmp = dup(stdout_pipe[1])) == -1)
  68                         goto stdout_opened;
  69                 close(stdout_pipe[1]);
  70                 stdout_pipe[1] = tmp;
  71         }
  72
  73         switch ((child = vfork())) {
  74         case -1:
  75                 goto stdout_opened;
  76         case 0:
  77                 close(stdin_pipe[1]);
  78                 close(stdout_pipe[0]);
  79                 if (dup2(stdin_pipe[0], STDIN_FILENO) == -1)
  80                         _exit(254);
  81                 if (stdin_pipe[0] != STDIN_FILENO)
  82                         close(stdin_pipe[0]);
  83                 if (dup2(stdout_pipe[1], STDOUT_FILENO) == -1)
  84                         _exit(254);
  85                 if (stdout_pipe[1] != STDOUT_FILENO)
  86                         close(stdout_pipe[1]);
  87                 execlp(path, path, (char *)NULL);
  88                 _exit(254);
  89         default:
  90                 close(stdin_pipe[0]);
  91                 close(stdout_pipe[1]);
  92
  93                 *child_stdin = stdin_pipe[1];
  94                 fcntl(*child_stdin, F_SETFL, O_NONBLOCK);
  95                 *child_stdout = stdout_pipe[0];
  96                 fcntl(*child_stdout, F_SETFL, O_NONBLOCK);
  97         }
  98
  99         return child;
 100
 101 stdout_opened:
 102         close(stdout_pipe[0]);
 103         close(stdout_pipe[1]);
 104 stdin_opened:
 105         close(stdin_pipe[0]);
 106         close(stdin_pipe[1]);
 107 state_allocated:
 108         return -1;
 109 }
 110
 111 void
 112 __archive_check_child(int in, int out)
 113 {
 114 #if defined(HAVE_POLL)
 115         struct pollfd fds[2];
 116
 117         fds[0].fd = in;
 118         fds[0].events = POLLOUT;
 119         fds[1].fd = out;
 120         fds[1].events = POLLIN;
 121
 122         poll(fds, 2, -1); /* -1 == INFTIM, wait forever */
 123 #elif defined(HAVE_SELECT)
 124         fd_set fds_in, fds_out, fds_error;
 125
 126         FD_ZERO(&fds_in);
 127         FD_SET(out, &fds_in);
 128         FD_ZERO(&fds_out);
 129         FD_SET(in, &fds_out);
 130         FD_ZERO(&fds_error);
 131         FD_SET(in, &fds_error);
 132         FD_SET(out, &fds_error);
 133         select(in < out ? out + 1 : in + 1, &fds_in, &fds_out, &fds_error, NULL);
 134 #else
 135         sleep(1);
 136 #endif
 137 }