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) 2004-2009 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 3 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, visit the http://fsf.org website.
27 extern int blocking_io;
28 extern int filesfrom_fd;
29 extern int munge_symlinks;
30 extern mode_t orig_umask;
31 extern char *logfile_name;
32 extern int remote_option_cnt;
33 extern const char **remote_options;
34 extern struct chmod_mode_struct *chmod_modes;
37 * Create a child connected to us via its stdin/stdout.
39 * This is derived from CVS code
41 * Note that in the child STDIN is set to blocking and STDOUT
42 * is set to non-blocking. This is necessary as rsh relies on stdin being blocking
43 * and ssh relies on stdout being non-blocking
45 * If blocking_io is set then use blocking io on both fds. That can be
46 * used to cope with badly broken rsh implementations like the one on
49 pid_t piped_child(char **command, int *f_in, int *f_out)
53 int from_child_pipe[2];
55 if (DEBUG_GTE(CMD, 1))
56 print_child_argv("opening connection using:", command);
58 if (fd_pair(to_child_pipe) < 0 || fd_pair(from_child_pipe) < 0) {
59 rsyserr(FERROR, errno, "pipe");
60 exit_cleanup(RERR_IPC);
65 rsyserr(FERROR, errno, "fork");
66 exit_cleanup(RERR_IPC);
70 if (dup2(to_child_pipe[0], STDIN_FILENO) < 0 ||
71 close(to_child_pipe[1]) < 0 ||
72 close(from_child_pipe[0]) < 0 ||
73 dup2(from_child_pipe[1], STDOUT_FILENO) < 0) {
74 rsyserr(FERROR, errno, "Failed to dup/close");
75 exit_cleanup(RERR_IPC);
77 if (to_child_pipe[0] != STDIN_FILENO)
78 close(to_child_pipe[0]);
79 if (from_child_pipe[1] != STDOUT_FILENO)
80 close(from_child_pipe[1]);
82 set_blocking(STDIN_FILENO);
84 set_blocking(STDOUT_FILENO);
85 execvp(command[0], command);
86 rsyserr(FERROR, errno, "Failed to exec %s", command[0]);
87 exit_cleanup(RERR_IPC);
90 if (close(from_child_pipe[1]) < 0 || close(to_child_pipe[0]) < 0) {
91 rsyserr(FERROR, errno, "Failed to close");
92 exit_cleanup(RERR_IPC);
95 *f_in = from_child_pipe[0];
96 *f_out = to_child_pipe[1];
101 /* This function forks a child which calls child_main(). First,
102 * however, it has to establish communication paths to and from the
103 * newborn child. It creates two socket pairs -- one for writing to
104 * the child (from the parent) and one for reading from the child
105 * (writing to the parent). Since that's four socket ends, each
106 * process has to close the two ends it doesn't need. The remaining
107 * two socket ends are retained for reading and writing. In the
108 * child, the STDIN and STDOUT file descriptors refer to these
109 * sockets. In the parent, the function arguments f_in and f_out are
110 * set to refer to these sockets. */
111 pid_t local_child(int argc, char **argv, int *f_in, int *f_out,
112 int (*child_main)(int, char*[]))
115 int to_child_pipe[2];
116 int from_child_pipe[2];
118 /* The parent process is always the sender for a local rsync. */
121 if (fd_pair(to_child_pipe) < 0 ||
122 fd_pair(from_child_pipe) < 0) {
123 rsyserr(FERROR, errno, "pipe");
124 exit_cleanup(RERR_IPC);
129 rsyserr(FERROR, errno, "fork");
130 exit_cleanup(RERR_IPC);
137 munge_symlinks = 0; /* Each side needs its own option. */
138 chmod_modes = NULL; /* Let the sending side handle this. */
140 /* Let the client side handle this. */
146 if (remote_option_cnt) {
147 int rc = remote_option_cnt + 1;
148 const char **rv = remote_options;
149 if (!parse_arguments(&rc, &rv)) {
151 exit_cleanup(RERR_SYNTAX);
155 if (dup2(to_child_pipe[0], STDIN_FILENO) < 0 ||
156 close(to_child_pipe[1]) < 0 ||
157 close(from_child_pipe[0]) < 0 ||
158 dup2(from_child_pipe[1], STDOUT_FILENO) < 0) {
159 rsyserr(FERROR, errno, "Failed to dup/close");
160 exit_cleanup(RERR_IPC);
162 if (to_child_pipe[0] != STDIN_FILENO)
163 close(to_child_pipe[0]);
164 if (from_child_pipe[1] != STDOUT_FILENO)
165 close(from_child_pipe[1]);
169 child_main(argc, argv);
172 if (close(from_child_pipe[1]) < 0 ||
173 close(to_child_pipe[0]) < 0) {
174 rsyserr(FERROR, errno, "Failed to close");
175 exit_cleanup(RERR_IPC);
178 *f_in = from_child_pipe[0];
179 *f_out = to_child_pipe[1];