contrib/libarchive-2/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 /* This capability is only available on POSIX systems. */
  29 #if defined(HAVE_PIPE) && defined(HAVE_FCNTL) && \
  30     (defined(HAVE_FORK) || defined(HAVE_VFORK))
  31
  32 __FBSDID("$FreeBSD: src/lib/libarchive/filter_fork.c,v 1.4 2008/06/15 10:45:57 kientzle Exp $");
  33
  34 #if defined(HAVE_POLL)
  35 #  if defined(HAVE_POLL_H)
  36 #    include <poll.h>
  37 #  elif defined(HAVE_SYS_POLL_H)
  38 #    include <sys/poll.h>
  39 #  endif
  40 #elif defined(HAVE_SELECT)
  41 #  if defined(HAVE_SYS_SELECT_H)
  42 #    include <sys/select.h>
  43 #  elif defined(HAVE_UNISTD_H)
  44 #    include <unistd.h>
  45 #  endif
  46 #endif
  47 #ifdef HAVE_FCNTL_H
  48 #  include <fcntl.h>
  49 #endif
  50 #ifdef HAVE_UNISTD_H
  51 #  include <unistd.h>
  52 #endif
  53
  54 #include "filter_fork.h"
  55
  56 pid_t
  57 __archive_create_child(const char *path, int *child_stdin, int *child_stdout)
  58 {
  59         pid_t child;
  60         int stdin_pipe[2], stdout_pipe[2], tmp;
  61
  62         if (pipe(stdin_pipe) == -1)
  63                 goto state_allocated;
  64         if (stdin_pipe[0] == STDOUT_FILENO) {
  65                 if ((tmp = dup(stdin_pipe[0])) == -1)
  66                         goto stdin_opened;
  67                 close(stdin_pipe[0]);
  68                 stdin_pipe[0] = tmp;
  69         }
  70         if (pipe(stdout_pipe) == -1)
  71                 goto stdin_opened;
  72         if (stdout_pipe[1] == STDIN_FILENO) {
  73                 if ((tmp = dup(stdout_pipe[1])) == -1)
  74                         goto stdout_opened;
  75                 close(stdout_pipe[1]);
  76                 stdout_pipe[1] = tmp;
  77         }
  78
  79 #if HAVE_VFORK
  80         switch ((child = vfork())) {
  81 #else
  82         switch ((child = fork())) {
  83 #endif
  84         case -1:
  85                 goto stdout_opened;
  86         case 0:
  87                 close(stdin_pipe[1]);
  88                 close(stdout_pipe[0]);
  89                 if (dup2(stdin_pipe[0], STDIN_FILENO) == -1)
  90                         _exit(254);
  91                 if (stdin_pipe[0] != STDIN_FILENO)
  92                         close(stdin_pipe[0]);
  93                 if (dup2(stdout_pipe[1], STDOUT_FILENO) == -1)
  94                         _exit(254);
  95                 if (stdout_pipe[1] != STDOUT_FILENO)
  96                         close(stdout_pipe[1]);
  97                 execlp(path, path, (char *)NULL);
  98                 _exit(254);
  99         default:
 100                 close(stdin_pipe[0]);
 101                 close(stdout_pipe[1]);
 102
 103                 *child_stdin = stdin_pipe[1];
 104                 fcntl(*child_stdin, F_SETFL, O_NONBLOCK);
 105                 *child_stdout = stdout_pipe[0];
 106                 fcntl(*child_stdout, F_SETFL, O_NONBLOCK);
 107         }
 108
 109         return child;
 110
 111 stdout_opened:
 112         close(stdout_pipe[0]);
 113         close(stdout_pipe[1]);
 114 stdin_opened:
 115         close(stdin_pipe[0]);
 116         close(stdin_pipe[1]);
 117 state_allocated:
 118         return -1;
 119 }
 120
 121 void
 122 __archive_check_child(int in, int out)
 123 {
 124 #if defined(HAVE_POLL)
 125         struct pollfd fds[2];
 126         int idx;
 127
 128         idx = 0;
 129         if (in != -1) {
 130                 fds[idx].fd = in;
 131                 fds[idx].events = POLLOUT;
 132                 ++idx;
 133         }
 134         if (out != -1) {
 135                 fds[idx].fd = out;
 136                 fds[idx].events = POLLIN;
 137                 ++idx;
 138         }
 139
 140         poll(fds, idx, -1); /* -1 == INFTIM, wait forever */
 141 #elif defined(HAVE_SELECT)
 142         fd_set fds_in, fds_out, fds_error;
 143
 144         FD_ZERO(&fds_in);
 145         FD_ZERO(&fds_out);
 146         FD_ZERO(&fds_error);
 147         if (out != -1) {
 148                 FD_SET(out, &fds_in);
 149                 FD_SET(out, &fds_error);
 150         }
 151         if (in != -1) {
 152                 FD_SET(in, &fds_out);
 153                 FD_SET(in, &fds_error);
 154         }
 155         select(in < out ? out + 1 : in + 1, &fds_in, &fds_out, &fds_error, NULL);
 156 #else
 157         sleep(1);
 158 #endif
 159 }
 160
 161 #endif /* defined(HAVE_PIPE) && defined(HAVE_VFORK) && defined(HAVE_FCNTL) */