filter_fork.c revision 228759 
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: head/lib/libarchive/filter_fork.c 182958 2008-09-12 05:33:00Z kientzle $");
33
34#if defined(HAVE_POLL) && (defined(HAVE_POLL_H) || defined(HAVE_SYS_POLL_H))
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
56pid_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] == 1 /* stdout */) {
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] == 0 /* stdin */) {
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], 0 /* stdin */) == -1)
90			_exit(254);
91		if (stdin_pipe[0] != 0 /* stdin */)
92			close(stdin_pipe[0]);
93		if (dup2(stdout_pipe[1], 1 /* stdout */) == -1)
94			_exit(254);
95		if (stdout_pipe[1] != 1 /* stdout */)
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
111stdout_opened:
112	close(stdout_pipe[0]);
113	close(stdout_pipe[1]);
114stdin_opened:
115	close(stdin_pipe[0]);
116	close(stdin_pipe[1]);
117state_allocated:
118	return -1;
119}
120
121void
122__archive_check_child(int in, int out)
123{
124#if defined(HAVE_POLL) && (defined(HAVE_POLL_H) || defined(HAVE_SYS_POLL_H))
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) */
162