1: /*
2: * Routines used to setup various kinds of inter-process pipes.
3: *
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) 2004-2013 Wayne Davison
8: *
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.
13: *
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.
18: *
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.
21: */
22:
23: #include "rsync.h"
24:
25: extern int am_sender;
26: extern int am_server;
27: extern int blocking_io;
28: extern int filesfrom_fd;
29: extern int munge_symlinks;
30: extern char *logfile_name;
31: extern int remote_option_cnt;
32: extern const char **remote_options;
33: extern struct chmod_mode_struct *chmod_modes;
34:
35: /**
36: * Create a child connected to us via its stdin/stdout.
37: *
38: * This is derived from CVS code
39: *
40: * Note that in the child STDIN is set to blocking and STDOUT
41: * is set to non-blocking. This is necessary as rsh relies on stdin being blocking
42: * and ssh relies on stdout being non-blocking
43: *
44: * If blocking_io is set then use blocking io on both fds. That can be
45: * used to cope with badly broken rsh implementations like the one on
46: * Solaris.
47: **/
48: pid_t piped_child(char **command, int *f_in, int *f_out)
49: {
50: pid_t pid;
51: int to_child_pipe[2];
52: int from_child_pipe[2];
53:
54: if (DEBUG_GTE(CMD, 1))
55: print_child_argv("opening connection using:", command);
56:
57: if (fd_pair(to_child_pipe) < 0 || fd_pair(from_child_pipe) < 0) {
58: rsyserr(FERROR, errno, "pipe");
59: exit_cleanup(RERR_IPC);
60: }
61:
62: pid = do_fork();
63: if (pid == -1) {
64: rsyserr(FERROR, errno, "fork");
65: exit_cleanup(RERR_IPC);
66: }
67:
68: if (pid == 0) {
69: if (dup2(to_child_pipe[0], STDIN_FILENO) < 0 ||
70: close(to_child_pipe[1]) < 0 ||
71: close(from_child_pipe[0]) < 0 ||
72: dup2(from_child_pipe[1], STDOUT_FILENO) < 0) {
73: rsyserr(FERROR, errno, "Failed to dup/close");
74: exit_cleanup(RERR_IPC);
75: }
76: if (to_child_pipe[0] != STDIN_FILENO)
77: close(to_child_pipe[0]);
78: if (from_child_pipe[1] != STDOUT_FILENO)
79: close(from_child_pipe[1]);
80: set_blocking(STDIN_FILENO);
81: if (blocking_io > 0)
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);
86: }
87:
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);
91: }
92:
93: *f_in = from_child_pipe[0];
94: *f_out = to_child_pipe[1];
95:
96: return pid;
97: }
98:
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*[]))
111: {
112: pid_t pid;
113: int to_child_pipe[2];
114: int from_child_pipe[2];
115:
116: /* The parent process is always the sender for a local rsync. */
117: assert(am_sender);
118:
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);
123: }
124:
125: pid = do_fork();
126: if (pid == -1) {
127: rsyserr(FERROR, errno, "fork");
128: exit_cleanup(RERR_IPC);
129: }
130:
131: if (pid == 0) {
132: am_sender = 0;
133: am_server = 1;
134: filesfrom_fd = -1;
135: munge_symlinks = 0; /* Each side needs its own option. */
136: chmod_modes = NULL; /* Let the sending side handle this. */
137:
138: /* Let the client side handle this. */
139: if (logfile_name) {
140: logfile_name = NULL;
141: logfile_close();
142: }
143:
144: if (remote_option_cnt) {
145: int rc = remote_option_cnt + 1;
146: const char **rv = remote_options;
147: if (!parse_arguments(&rc, &rv)) {
148: option_error();
149: exit_cleanup(RERR_SYNTAX);
150: }
151: }
152:
153: if (dup2(to_child_pipe[0], STDIN_FILENO) < 0 ||
154: close(to_child_pipe[1]) < 0 ||
155: close(from_child_pipe[0]) < 0 ||
156: dup2(from_child_pipe[1], STDOUT_FILENO) < 0) {
157: rsyserr(FERROR, errno, "Failed to dup/close");
158: exit_cleanup(RERR_IPC);
159: }
160: if (to_child_pipe[0] != STDIN_FILENO)
161: close(to_child_pipe[0]);
162: if (from_child_pipe[1] != STDOUT_FILENO)
163: close(from_child_pipe[1]);
164: #ifdef ICONV_CONST
165: setup_iconv();
166: #endif
167: child_main(argc, argv);
168: }
169:
170: if (close(from_child_pipe[1]) < 0 ||
171: close(to_child_pipe[0]) < 0) {
172: rsyserr(FERROR, errno, "Failed to close");
173: exit_cleanup(RERR_IPC);
174: }
175:
176: *f_in = from_child_pipe[0];
177: *f_out = to_child_pipe[1];
178:
179: return pid;
180: }
FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>
![[BACK]](/icons/cvsweb/back.gif){kind=icon}
Return to pipe.c CVS log ![[TXT]](/icons/cvsweb/text.gif){kind=icon}
![[DIR]](/icons/cvsweb/dir.gif){kind=icon}
Up to [ELWIX - Embedded LightWeight unIX -] / embedaddon / rsync