1 /* Copyright (C) 1998 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Zack Weinberg <zack@rabi.phys.columbia.edu>, 1998.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Library General Public License as
7 published by the Free Software Foundation; either version 2 of the
8 License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Library General Public License for more details.
15 You should have received a copy of the GNU Library General Public
16 License along with the GNU C Library; see the file COPYING.LIB. If not,
17 see <http://www.gnu.org/licenses/>. */
25 #include <sys/resource.h>
27 #include <sys/types.h>
30 #include "pty-private.h"
33 /* Return the result of ptsname_r in the buffer pointed to by PTS,
34 which should be of length BUF_LEN. If it is too long to fit in
35 this buffer, a sufficiently long buffer is allocated using malloc,
36 and returned in PTS. 0 is returned upon success, -1 otherwise. */
38 pts_name (int fd, char **pts, size_t buf_len)
49 rv = ptsname_r (fd, buf, buf_len);
51 if (rv != 0 || memchr (buf, '\0', buf_len))
52 /* We either got an error, or we succeeded and the
53 returned name fit in the buffer. */
56 /* Try again with a longer buffer. */
57 buf_len += buf_len; /* Double it */
60 /* No initial buffer; start out by mallocing one. */
61 buf_len = 128; /* First time guess. */
64 /* We've already malloced another buffer at least once. */
65 new_buf = realloc (buf, buf_len);
67 new_buf = malloc (buf_len);
78 *pts = buf; /* Return buffer to the user. */
80 free (buf); /* Free what we malloced when returning an error. */
85 /* Change the ownership and access permission of the slave pseudo
86 terminal associated with the master pseudo terminal specified
103 if (pts_name (fd, &buf, sizeof (_buf)))
106 if (stat(buf, &st) < 0)
109 /* Make sure that we own the device. */
111 if (st.st_uid != uid)
113 if (chown (buf, uid, st.st_gid) < 0)
119 /* Make sure the group of the device is that special group. */
120 if (st.st_gid != gid)
122 if (chown (buf, uid, gid) < 0)
126 /* Make sure the permission mode is set to readable and writable by
127 the owner, and writable by the group. */
128 if ((st.st_mode & ACCESSPERMS) != (S_IRUSR|S_IWUSR|S_IWGRP))
130 if (chmod (buf, S_IRUSR|S_IWUSR|S_IWGRP) < 0)
137 /* We have to use the helper program. */
145 /* Disable core dumps. */
146 struct rlimit rl = { 0, 0 };
147 setrlimit (RLIMIT_CORE, &rl);
149 /* We pase the master pseudo terminal as file descriptor PTY_FILENO. */
150 if (fd != PTY_FILENO)
151 if (dup2 (fd, PTY_FILENO) < 0)
154 execle (_PATH_PT_CHOWN, _PATH_PT_CHOWN, NULL, NULL);
161 if (waitpid (pid, &w, 0) == -1)
166 switch (WEXITSTATUS(w))
185 assert(! "getpt: internal error: invalid exit code from pt_chown");