2 * Routines used to setup various kinds of inter-process pipes.
4 * Copyright (C) 1996-2000 Andrew Tridgell
5 * Copyright (C) 1996 Paul Mackerras
6 * Copyright (C) 2001, 2002 Martin Pool <mbp@samba.org>
7 * Copyright (C) 2004-2007 Wayne Davison
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 3 as
11 * published by the Free Software Foundation.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License along
19 * with this program; if not, visit the http://fsf.org website.
26 extern int blocking_io;
27 extern int filesfrom_fd;
28 extern mode_t orig_umask;
29 extern char *logfile_name;
30 extern struct chmod_mode_struct *chmod_modes;
33 * Create a child connected to us via its 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);
54 if (fd_pair(to_child_pipe) < 0 || fd_pair(from_child_pipe) < 0) {
55 rsyserr(FERROR, errno, "pipe");
56 exit_cleanup(RERR_IPC);
61 rsyserr(FERROR, errno, "fork");
62 exit_cleanup(RERR_IPC);
66 if (dup2(to_child_pipe[0], STDIN_FILENO) < 0 ||
67 close(to_child_pipe[1]) < 0 ||
68 close(from_child_pipe[0]) < 0 ||
69 dup2(from_child_pipe[1], STDOUT_FILENO) < 0) {
70 rsyserr(FERROR, errno, "Failed to dup/close");
71 exit_cleanup(RERR_IPC);
73 if (to_child_pipe[0] != STDIN_FILENO)
74 close(to_child_pipe[0]);
75 if (from_child_pipe[1] != STDOUT_FILENO)
76 close(from_child_pipe[1]);
78 set_blocking(STDIN_FILENO);
80 set_blocking(STDOUT_FILENO);
81 execvp(command[0], command);
82 rsyserr(FERROR, errno, "Failed to exec %s", command[0]);
83 exit_cleanup(RERR_IPC);
86 if (close(from_child_pipe[1]) < 0 || close(to_child_pipe[0]) < 0) {
87 rsyserr(FERROR, errno, "Failed to close");
88 exit_cleanup(RERR_IPC);
91 *f_in = from_child_pipe[0];
92 *f_out = to_child_pipe[1];
97 /* This function forks a child which calls child_main(). First,
98 * however, it has to establish communication paths to and from the
99 * newborn child. It creates two socket pairs -- one for writing to
100 * the child (from the parent) and one for reading from the child
101 * (writing to the parent). Since that's four socket ends, each
102 * process has to close the two ends it doesn't need. The remaining
103 * two socket ends are retained for reading and writing. In the
104 * child, the STDIN and STDOUT file descriptors refer to these
105 * sockets. In the parent, the function arguments f_in and f_out are
106 * set to refer to these sockets. */
107 pid_t local_child(int argc, char **argv, int *f_in, int *f_out,
108 int (*child_main)(int, char*[]))
111 int to_child_pipe[2];
112 int from_child_pipe[2];
114 /* The parent process is always the sender for a local rsync. */
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);
125 rsyserr(FERROR, errno, "fork");
126 exit_cleanup(RERR_IPC);
133 chmod_modes = NULL; /* Let the sending side handle this. */
135 if (dup2(to_child_pipe[0], STDIN_FILENO) < 0 ||
136 close(to_child_pipe[1]) < 0 ||
137 close(from_child_pipe[0]) < 0 ||
138 dup2(from_child_pipe[1], STDOUT_FILENO) < 0) {
139 rsyserr(FERROR, errno, "Failed to dup/close");
140 exit_cleanup(RERR_IPC);
142 if (to_child_pipe[0] != STDIN_FILENO)
143 close(to_child_pipe[0]);
144 if (from_child_pipe[1] != STDOUT_FILENO)
145 close(from_child_pipe[1]);
146 child_main(argc, argv);
149 /* Let the client side handle this. */
155 if (close(from_child_pipe[1]) < 0 ||
156 close(to_child_pipe[0]) < 0) {
157 rsyserr(FERROR, errno, "Failed to close");
158 exit_cleanup(RERR_IPC);
161 *f_in = from_child_pipe[0];
162 *f_out = to_child_pipe[1];