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 filesfrom_fd;
29 extern struct chmod_mode_struct *chmod_modes;
32 * Create a child connected to us via its stdin/stdout.
34 * This is derived from CVS code
36 * Note that in the child STDIN is set to blocking and STDOUT
37 * is set to non-blocking. This is necessary as rsh relies on stdin being blocking
38 * and ssh relies on stdout being non-blocking
40 * If blocking_io is set then use blocking io on both fds. That can be
41 * used to cope with badly broken rsh implementations like the one on
44 pid_t piped_child(char **command, int *f_in, int *f_out)
48 int from_child_pipe[2];
51 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 if (close(from_child_pipe[1]) < 0 ||
150 close(to_child_pipe[0]) < 0) {
151 rsyserr(FERROR, errno, "Failed to close");
152 exit_cleanup(RERR_IPC);
155 *f_in = from_child_pipe[0];
156 *f_out = to_child_pipe[1];