1 /*
2 * childio.c -- set up communication with child processes
3 *
4 * Copyright 1991 by Digital Equipment Corporation, Maynard,
5 * Massachusetts.
6 *
7 * Enhancements Copyright 1992-2001, 2002, 2003, 2004, 2005, 2006,
8 * 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015 Free Software Foundation, Inc.
9 *
10 * The following terms apply to Digital Equipment Corporation's copyright
11 * interest in XBoard:
12 * ------------------------------------------------------------------------
13 * All Rights Reserved
14 *
15 * Permission to use, copy, modify, and distribute this software and its
16 * documentation for any purpose and without fee is hereby granted,
17 * provided that the above copyright notice appear in all copies and that
18 * both that copyright notice and this permission notice appear in
19 * supporting documentation, and that the name of Digital not be
20 * used in advertising or publicity pertaining to distribution of the
21 * software without specific, written prior permission.
22 *
23 * DIGITAL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
24 * ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
25 * DIGITAL BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
26 * ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
27 * WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
28 * ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
29 * SOFTWARE.
30 * ------------------------------------------------------------------------
31 *
32 * The following terms apply to the enhanced version of XBoard
33 * distributed by the Free Software Foundation:
34 * ------------------------------------------------------------------------
35 *
36 * GNU XBoard is free software: you can redistribute it and/or modify
37 * it under the terms of the GNU General Public License as published by
38 * the Free Software Foundation, either version 3 of the License, or (at
39 * your option) any later version.
40 *
41 * GNU XBoard is distributed in the hope that it will be useful, but
42 * WITHOUT ANY WARRANTY; without even the implied warranty of
43 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
44 * General Public License for more details.
45 *
46 * You should have received a copy of the GNU General Public License
47 * along with this program. If not, see http://www.gnu.org/licenses/. *
48 *
49 *------------------------------------------------------------------------
50 ** See the file ChangeLog for a revision history. */
51
52 /* This file splits into two entirely different pieces of code
53 depending on whether USE_PTYS is 1. The whole reason for all
54 the pty nonsense is that select() does not work on pipes in System-V
55 derivatives (at least some of them). This is a problem because
56 XtAppAddInput works by adding its argument to a select that is done
57 deep inside Xlib.
58 */
59
60 #include "config.h"
61
62 #include <stdio.h>
63 #include <signal.h>
64 #if HAVE_UNISTD_H
65 # include <unistd.h>
66 #endif
67
68 #include "common.h"
69 #include "frontend.h"
70 #include "backend.h" /* for safeStrCpy */
71
72 #if !USE_PTYS
73 /* This code is for systems where pipes work properly */
74
75 void
SetUpChildIO(int to_prog[2],int from_prog[2])76 SetUpChildIO (int to_prog[2], int from_prog[2])
77 {
78 signal(SIGPIPE, SIG_IGN);
79 pipe(to_prog);
80 pipe(from_prog);
81 }
82
83 #else /* USE_PTYS == 1 */
84 /* This code is for all systems where we must use ptys */
85
86 #include <errno.h>
87 #include <sys/stat.h>
88 #include <sys/ioctl.h>
89 #if HAVE_STROPTS_H
90 # include <stropts.h>
91 #endif /* HAVE_STROPTS_H */
92 #if HAVE_SYS_FCNTL_H
93 # include <sys/fcntl.h>
94 #else /* not HAVE_SYS_FCNTL_H */
95 # if HAVE_FCNTL_H
96 # include <fcntl.h>
97 # endif /* HAVE_FCNTL_H */
98 #endif /* not HAVE_SYS_FCNTL_H */
99
100 int PseudoTTY P((char pty_name[]));
101
102 int
SetUpChildIO(int to_prog[2],int from_prog[2])103 SetUpChildIO (int to_prog[2], int from_prog[2])
104 {
105 char pty_name[MSG_SIZ];
106
107 if ((to_prog[1] = PseudoTTY(pty_name)) == -1) {
108 DisplayFatalError("Can't open pseudo-tty", errno, 1);
109 ExitEvent(1);
110 }
111 from_prog[0] = to_prog[1];
112 to_prog[0] = from_prog[1] = open(pty_name, O_RDWR, 0);
113
114 #if HAVE_STROPTS_H /* do we really need this?? pipe-like behavior is fine */
115 if (ioctl (to_prog[0], I_PUSH, "ptem") == -1 ||
116 ioctl (to_prog[0], I_PUSH, "ldterm") == -1 ||
117 ioctl (to_prog[0], I_PUSH, "ttcompat") == -1) {
118 # ifdef NOTDEF /* seems some systems don't have or need ptem and ttcompat */
119 DisplayFatalError("Can't ioctl pseudo-tty", errno, 1);
120 ExitEvent(1);
121 # endif /*NOTDEF*/
122 }
123 #endif /* HAVE_STROPTS_H */
124
125 }
126
127 #if HAVE_GRANTPT
128 /* This code is for SVR4 */
129
130 int
PseudoTTY(char pty_name[])131 PseudoTTY (char pty_name[])
132 {
133 extern char *ptsname();
134 char *ptss;
135 int fd;
136
137 fd = open("/dev/ptmx", O_RDWR);
138 if (fd < 0) return fd;
139 if (grantpt(fd) == -1) return -1;
140 if (unlockpt(fd) == -1) return -1;
141 if (!(ptss = ptsname(fd))) return -1;
142 safeStrCpy(pty_name, ptss, sizeof(pty_name)/sizeof(pty_name[0]));
143 return fd;
144 }
145
146 #else /* not HAVE_GRANTPT */
147 #if HAVE__GETPTY
148 /* This code is for IRIX */
149
150 int
PseudoTTY(char pty_name[])151 PseudoTTY (char pty_name[])
152 {
153 int fd;
154 char *ptyn;
155
156 ptyn = _getpty(&fd, O_RDWR, 0600, 0);
157 if (ptyn == NULL) return -1;
158 safeStrCpy(pty_name, ptyn, sizeof(pty_name)/sizeof(pty_name[0]));
159 return fd;
160 }
161
162 #else /* not HAVE__GETPTY */
163 #if HAVE_LIBSEQ
164 /* This code is for Sequent DYNIX/ptx. Untested. --tpm */
165
166 int
PseudoTTY(char pty_name[])167 PseudoTTY (char pty_name[])
168 {
169 int fd;
170 char *slave, *master;
171
172 fd = getpseudotty(&slave, &master);
173 if (fd < 0) return fd;
174 safeStrCpy(pty_name, slave, sizeof(pty_name)/sizeof(pty_name[0]));
175 return fd;
176 }
177
178 #else /* not HAVE_LIBSEQ */
179 /* This code is for all other systems */
180 /* The code is adapted from GNU Emacs 19.24 */
181
182 #ifndef FIRST_PTY_LETTER
183 #define FIRST_PTY_LETTER 'p'
184 #endif
185 #ifndef LAST_PTY_LETTER
186 #define LAST_PTY_LETTER 'z'
187 #endif
188
189 int
PseudoTTY(char pty_name[])190 PseudoTTY (char pty_name[])
191 {
192 struct stat stb;
193 register c, i;
194 int fd;
195
196 /* Some systems name their pseudoterminals so that there are gaps in
197 the usual sequence - for example, on HP9000/S700 systems, there
198 are no pseudoterminals with names ending in 'f'. So we wait for
199 three failures in a row before deciding that we've reached the
200 end of the ptys. */
201 int failed_count = 0;
202
203 #ifdef PTY_ITERATION
204 PTY_ITERATION
205 #else
206 for (c = FIRST_PTY_LETTER; c <= LAST_PTY_LETTER; c++)
207 for (i = 0; i < 16; i++)
208 #endif
209 {
210 #ifdef PTY_NAME_SPRINTF
211 PTY_NAME_SPRINTF
212 #else
213 sprintf (pty_name, "/dev/pty%c%x", c, i);
214 #endif /* no PTY_NAME_SPRINTF */
215
216 #ifdef PTY_OPEN
217 PTY_OPEN;
218 #else /* no PTY_OPEN */
219 if (stat (pty_name, &stb) < 0)
220 {
221 failed_count++;
222 if (failed_count >= 3)
223 return -1;
224 }
225 else
226 failed_count = 0;
227 fd = open (pty_name, O_RDWR, 0);
228 #endif /* no PTY_OPEN */
229
230 if (fd >= 0)
231 {
232 /* check to make certain that both sides are available
233 this avoids a nasty yet stupid bug in rlogins */
234 #ifdef PTY_TTY_NAME_SPRINTF
235 PTY_TTY_NAME_SPRINTF
236 #else
237 sprintf (pty_name, "/dev/tty%c%x", c, i);
238 #endif /* no PTY_TTY_NAME_SPRINTF */
239 #ifndef UNIPLUS
240 if (access (pty_name, 6) != 0)
241 {
242 close (fd);
243 continue;
244 }
245 #endif /* not UNIPLUS */
246 #ifdef IBMRTAIX
247 /* On AIX, the parent gets SIGHUP when a pty attached
248 child dies. So, we ignore SIGHUP once we've started
249 a child on a pty. Note that this may cause xboard
250 not to die when it should, i.e., when its own
251 controlling tty goes away.
252 */
253 signal(SIGHUP, SIG_IGN);
254 #endif /* IBMRTAIX */
255 return fd;
256 }
257 }
258 return -1;
259 }
260
261 #endif /* not HAVE_LIBSEQ */
262 #endif /* not HAVE__GETPTY */
263 #endif /* not HAVE_GRANTPT */
264 #endif /* USE_PTYS */
265