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authorEric Andersen <andersen@codepoet.org>2001-05-08 19:58:20 +0000
committerEric Andersen <andersen@codepoet.org>2001-05-08 19:58:20 +0000
commita3e03be058a9b9a2caf36c5b18f66c0fc3df3bf0 (patch)
tree2ad333bd1e56590e981eba3c54f6057cbf5758bb /libc/stdlib/unix_grantpt.c
parent6c0899094d50e0d35d699594bfcd9cae4164abe2 (diff)
Add in libutil, based on Cory Visi's variant of Michael Shmulevich's libutil
port. I have reworked the code quite a bit so that the stuff that is supposed to be in libc is in libc, and I added a bunch of missing stuff so the libutil interface matches that of glibc's libutil. The only caveat is that libutil/login.c is currently a stub. -Erik
Diffstat (limited to 'libc/stdlib/unix_grantpt.c')
-rw-r--r--libc/stdlib/unix_grantpt.c197
1 files changed, 197 insertions, 0 deletions
diff --git a/libc/stdlib/unix_grantpt.c b/libc/stdlib/unix_grantpt.c
new file mode 100644
index 000000000..eb6ce0b35
--- /dev/null
+++ b/libc/stdlib/unix_grantpt.c
@@ -0,0 +1,197 @@
+/* Copyright (C) 1998 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Zack Weinberg <zack@rabi.phys.columbia.edu>, 1998.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Library General Public License as
+ published by the Free Software Foundation; either version 2 of the
+ License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Library General Public License for more details.
+
+ You should have received a copy of the GNU Library General Public
+ License along with the GNU C Library; see the file COPYING.LIB. If not,
+ write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
+
+#include <assert.h>
+#include <errno.h>
+#include <grp.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/resource.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include "pty-private.h"
+
+extern int ptsname_r (int fd, char *buf, size_t buflen);
+
+/* Return the result of ptsname_r in the buffer pointed to by PTS,
+ which should be of length BUF_LEN. If it is too long to fit in
+ this buffer, a sufficiently long buffer is allocated using malloc,
+ and returned in PTS. 0 is returned upon success, -1 otherwise. */
+static int
+pts_name (int fd, char **pts, size_t buf_len)
+{
+ int rv;
+ char *buf = *pts;
+
+ for (;;)
+ {
+ char *new_buf;
+
+ if (buf_len)
+ {
+ rv = ptsname_r (fd, buf, buf_len);
+
+ if (rv != 0 || memchr (buf, '\0', buf_len))
+ /* We either got an error, or we succeeded and the
+ returned name fit in the buffer. */
+ break;
+
+ /* Try again with a longer buffer. */
+ buf_len += buf_len; /* Double it */
+ }
+ else
+ /* No initial buffer; start out by mallocing one. */
+ buf_len = 128; /* First time guess. */
+
+ if (buf != *pts)
+ /* We've already malloced another buffer at least once. */
+ new_buf = realloc (buf, buf_len);
+ else
+ new_buf = malloc (buf_len);
+ if (! new_buf)
+ {
+ rv = -1;
+ errno = ENOMEM;
+ break;
+ }
+ buf = new_buf;
+ }
+
+ if (rv == 0)
+ *pts = buf; /* Return buffer to the user. */
+ else if (buf != *pts)
+ free (buf); /* Free what we malloced when returning an error. */
+
+ return rv;
+}
+
+/* Change the ownership and access permission of the slave pseudo
+ terminal associated with the master pseudo terminal specified
+ by FD. */
+int
+grantpt (int fd)
+{
+ int retval = -1;
+#ifdef PATH_MAX
+ char _buf[PATH_MAX];
+#else
+ char _buf[512];
+#endif
+ char *buf = _buf;
+ struct stat st;
+ uid_t uid;
+ gid_t gid;
+ pid_t pid;
+
+ if (pts_name (fd, &buf, sizeof (_buf)))
+ return -1;
+
+ if (_xstat (_STAT_VER, buf, &st) < 0)
+ goto cleanup;
+
+ /* Make sure that we own the device. */
+ uid = getuid ();
+ if (st.st_uid != uid)
+ {
+ if (chown (buf, uid, st.st_gid) < 0)
+ goto helper;
+ }
+
+ gid = getgid ();
+
+ /* Make sure the group of the device is that special group. */
+ if (st.st_gid != gid)
+ {
+ if (chown (buf, uid, gid) < 0)
+ goto helper;
+ }
+
+ /* Make sure the permission mode is set to readable and writable by
+ the owner, and writable by the group. */
+ if ((st.st_mode & ACCESSPERMS) != (S_IRUSR|S_IWUSR|S_IWGRP))
+ {
+ if (chmod (buf, S_IRUSR|S_IWUSR|S_IWGRP) < 0)
+ goto helper;
+ }
+
+ retval = 0;
+ goto cleanup;
+
+ /* We have to use the helper program. */
+ helper:
+
+ pid = fork ();
+ if (pid == -1)
+ goto cleanup;
+ else if (pid == 0)
+ {
+ /* Disable core dumps. */
+ struct rlimit rl = { 0, 0 };
+ setrlimit (RLIMIT_CORE, &rl);
+
+ /* We pase the master pseudo terminal as file descriptor PTY_FILENO. */
+ if (fd != PTY_FILENO)
+ if (dup2 (fd, PTY_FILENO) < 0)
+ exit (FAIL_EBADF);
+
+ execle (_PATH_PT_CHOWN, _PATH_PT_CHOWN, NULL, NULL);
+ exit (FAIL_EXEC);
+ }
+ else
+ {
+ int w;
+
+ if (waitpid (pid, &w, 0) == -1)
+ goto cleanup;
+ if (!WIFEXITED (w))
+ errno = ENOEXEC;
+ else
+ switch (WEXITSTATUS(w))
+ {
+ case 0:
+ retval = 0;
+ break;
+ case FAIL_EBADF:
+ errno = EBADF;
+ break;
+ case FAIL_EINVAL:
+ errno = EINVAL;
+ break;
+ case FAIL_EACCES:
+ errno = EACCES;
+ break;
+ case FAIL_EXEC:
+ errno = ENOEXEC;
+ break;
+
+ default:
+ assert(! "getpt: internal error: invalid exit code from pt_chown");
+ }
+ }
+
+ cleanup:
+ if (buf != _buf)
+ free (buf);
+
+ return retval;
+}