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, 2005, 2006 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 as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write to the Free Software Foundation, Inc.,
21 * 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.
28 extern int blocking_io;
29 extern int filesfrom_fd;
30 extern mode_t orig_umask;
31 extern char *logfile_name;
32 extern struct chmod_mode_struct *chmod_modes;
35 * Create a child connected to us via its stdin/stdout.
37 * This is derived from CVS code
39 * Note that in the child STDIN is set to blocking and STDOUT
40 * is set to non-blocking. This is necessary as rsh relies on stdin being blocking
41 * and ssh relies on stdout being non-blocking
43 * If blocking_io is set then use blocking io on both fds. That can be
44 * used to cope with badly broken rsh implementations like the one on
47 pid_t piped_child(char **command, int *f_in, int *f_out)
51 int from_child_pipe[2];
54 print_child_argv(command);
56 if (fd_pair(to_child_pipe) < 0 || fd_pair(from_child_pipe) < 0) {
57 rsyserr(FERROR, errno, "pipe");
58 exit_cleanup(RERR_IPC);
63 rsyserr(FERROR, errno, "fork");
64 exit_cleanup(RERR_IPC);
68 if (dup2(to_child_pipe[0], STDIN_FILENO) < 0 ||
69 close(to_child_pipe[1]) < 0 ||
70 close(from_child_pipe[0]) < 0 ||
71 dup2(from_child_pipe[1], STDOUT_FILENO) < 0) {
72 rsyserr(FERROR, errno, "Failed to dup/close");
73 exit_cleanup(RERR_IPC);
75 if (to_child_pipe[0] != STDIN_FILENO)
76 close(to_child_pipe[0]);
77 if (from_child_pipe[1] != STDOUT_FILENO)
78 close(from_child_pipe[1]);
80 set_blocking(STDIN_FILENO);
82 set_blocking(STDOUT_FILENO);
83 execvp(command[0], command);
84 rsyserr(FERROR, errno, "Failed to exec %s", command[0]);
85 exit_cleanup(RERR_IPC);
88 if (close(from_child_pipe[1]) < 0 || close(to_child_pipe[0]) < 0) {
89 rsyserr(FERROR, errno, "Failed to close");
90 exit_cleanup(RERR_IPC);
93 *f_in = from_child_pipe[0];
94 *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. */
109 pid_t local_child(int argc, char **argv, int *f_in, int *f_out,
110 int (*child_main)(int, char*[]))
113 int to_child_pipe[2];
114 int from_child_pipe[2];
116 /* The parent process is always the sender for a local rsync. */
119 if (fd_pair(to_child_pipe) < 0 ||
120 fd_pair(from_child_pipe) < 0) {
121 rsyserr(FERROR, errno, "pipe");
122 exit_cleanup(RERR_IPC);
127 rsyserr(FERROR, errno, "fork");
128 exit_cleanup(RERR_IPC);
135 chmod_modes = NULL; /* Let the sending side handle this. */
137 if (dup2(to_child_pipe[0], STDIN_FILENO) < 0 ||
138 close(to_child_pipe[1]) < 0 ||
139 close(from_child_pipe[0]) < 0 ||
140 dup2(from_child_pipe[1], STDOUT_FILENO) < 0) {
141 rsyserr(FERROR, errno, "Failed to dup/close");
142 exit_cleanup(RERR_IPC);
144 if (to_child_pipe[0] != STDIN_FILENO)
145 close(to_child_pipe[0]);
146 if (from_child_pipe[1] != STDOUT_FILENO)
147 close(from_child_pipe[1]);
148 child_main(argc, argv);
151 /* Let the client side handle this. */
157 if (close(from_child_pipe[1]) < 0 ||
158 close(to_child_pipe[0]) < 0) {
159 rsyserr(FERROR, errno, "Failed to close");
160 exit_cleanup(RERR_IPC);
163 *f_in = from_child_pipe[0];
164 *f_out = to_child_pipe[1];