1 /* -*- c-file-style: "linux" -*-
3 * Copyright (C) 1996-2000 by Andrew Tridgell
4 * Copyright (C) Paul Mackerras 1996
5 * Copyright (C) 2001, 2002 by Martin Pool <mbp@samba.org>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
26 extern int blocking_io;
27 extern int orig_umask;
28 extern int read_batch;
29 extern int write_batch;
30 extern int filesfrom_fd;
33 * Create a child connected to use on stdin/stdout.
35 * This is derived from CVS code
37 * Note that in the child STDIN is set to blocking and STDOUT
38 * is set to non-blocking. This is necessary as rsh relies on stdin being blocking
39 * and ssh relies on stdout being non-blocking
41 * If blocking_io is set then use blocking io on both fds. That can be
42 * used to cope with badly broken rsh implementations like the one on
45 pid_t piped_child(char **command, int *f_in, int *f_out)
49 int from_child_pipe[2];
52 print_child_argv(command);
55 if (fd_pair(to_child_pipe) < 0 || fd_pair(from_child_pipe) < 0) {
56 rsyserr(FERROR, errno, "pipe");
57 exit_cleanup(RERR_IPC);
62 rsyserr(FERROR, errno, "fork");
63 exit_cleanup(RERR_IPC);
67 if (dup2(to_child_pipe[0], STDIN_FILENO) < 0 ||
68 close(to_child_pipe[1]) < 0 ||
69 close(from_child_pipe[0]) < 0 ||
70 dup2(from_child_pipe[1], STDOUT_FILENO) < 0) {
71 rsyserr(FERROR, errno, "Failed to dup/close");
72 exit_cleanup(RERR_IPC);
74 if (to_child_pipe[0] != STDIN_FILENO)
75 close(to_child_pipe[0]);
76 if (from_child_pipe[1] != STDOUT_FILENO)
77 close(from_child_pipe[1]);
79 set_blocking(STDIN_FILENO);
81 set_blocking(STDOUT_FILENO);
82 execvp(command[0], command);
83 rsyserr(FERROR, errno, "Failed to exec %s", command[0]);
84 exit_cleanup(RERR_IPC);
87 if (close(from_child_pipe[1]) < 0 || close(to_child_pipe[0]) < 0) {
88 rsyserr(FERROR, errno, "Failed to close");
89 exit_cleanup(RERR_IPC);
92 *f_in = from_child_pipe[0];
93 *f_out = to_child_pipe[1];
99 * This function forks a child which calls child_main(). First,
100 * however, it has to establish communication paths to and from the
101 * newborn child. It creates two socket pairs -- one for writing to
102 * the child (from the parent) and one for reading from the child
103 * (writing to the parent). Since that's four socket ends, each
104 * process has to close the two ends it doesn't need. The remaining
105 * two socket ends are retained for reading and writing. In the
106 * child, the STDIN and STDOUT file descriptors refer to these
107 * sockets. In the parent, the function arguments f_in and f_out are
108 * set to refer to these sockets.
110 pid_t local_child(int argc, char **argv, int *f_in, int *f_out,
111 int (*child_main)(int, char*[]))
114 int to_child_pipe[2];
115 int from_child_pipe[2];
117 if (fd_pair(to_child_pipe) < 0 ||
118 fd_pair(from_child_pipe) < 0) {
119 rsyserr(FERROR, errno, "pipe");
120 exit_cleanup(RERR_IPC);
123 /* For read-batch, don't even fork. */
124 pid = read_batch ? getpid() : do_fork();
127 rsyserr(FERROR, errno, "fork");
128 exit_cleanup(RERR_IPC);
132 am_sender = !am_sender;
135 /* The server side never writes the batch, even if it
136 * is local (it makes the logic easier elsewhere). */
142 if (dup2(to_child_pipe[0], STDIN_FILENO) < 0 ||
143 close(to_child_pipe[1]) < 0 ||
144 close(from_child_pipe[0]) < 0 ||
145 dup2(from_child_pipe[1], STDOUT_FILENO) < 0) {
146 rsyserr(FERROR, errno, "Failed to dup/close");
147 exit_cleanup(RERR_IPC);
149 if (to_child_pipe[0] != STDIN_FILENO)
150 close(to_child_pipe[0]);
151 if (from_child_pipe[1] != STDOUT_FILENO)
152 close(from_child_pipe[1]);
153 child_main(argc, argv);
159 if (close(from_child_pipe[1]) < 0 ||
160 close(to_child_pipe[0]) < 0) {
161 rsyserr(FERROR, errno, "Failed to close");
162 exit_cleanup(RERR_IPC);
165 *f_in = from_child_pipe[0];
166 *f_out = to_child_pipe[1];