1 files changed, 286 insertions, 0 deletions
diff --git a/lib/libc/stdlib/grantpt.c b/lib/libc/stdlib/grantpt.c
new file mode 100644
index 0000000..8570f8b
--- /dev/null
+++ b/lib/libc/stdlib/grantpt.c
@@ -0,0 +1,286 @@
+/*
+ * Copyright (c) 2002 The FreeBSD Project, Inc.
+ * All rights reserved.
+ *
+ * This software includes code contributed to the FreeBSD Project
+ * by Ryan Younce of North Carolina State University.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the FreeBSD Project nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE FREEBSD PROJECT AND CONTRIBUTORS ``AS IS''
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE FREEBSD PROJECT OR ITS CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+#ifndef lint
+__FBSDID("$FreeBSD$");
+#endif /* not lint */
+
+#include "namespace.h"
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <sys/sysctl.h>
+#include <sys/ioctl.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <grp.h>
+#include <paths.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sysexits.h>
+#include <unistd.h>
+#include "un-namespace.h"
+
+#define PTYM_PREFIX	"pty"	/* pty(4) master naming convention */
+#define PTYS_PREFIX	"tty"	/* pty(4) slave naming convention */
+#define PTMXS_PREFIX	"pts/"	/* pts(4) slave naming convention */
+#define PTMX		"ptmx"
+
+/*
+ * The following are range values for pseudo TTY devices.  Pseudo TTYs have a
+ * name of /dev/[pt]ty[l-sL-S][0-9a-v].
+ */
+#define	PTY_DEV1	"pqrsPQRSlmnoLMNO"
+#define PTY_DEV2	"0123456789abcdefghijklmnopqrstuv"
+
+/*
+ * grantpt(3) support utility.
+ */
+#define _PATH_PTCHOWN	"/usr/libexec/pt_chown"
+
+int
+__use_pts(void)
+{
+	int use_pts;
+	size_t len;
+	int error;
+
+	len = sizeof(use_pts);
+	error = sysctlbyname("kern.pts.enable", &use_pts, &len, NULL, 0);
+	if (error) {
+		struct stat sb;
+
+		if (stat(_PATH_DEV PTMX, &sb) != 0)
+			return (0);
+		use_pts = 1;
+	}
+	return (use_pts);
+}
+
+/*
+ * grantpt():  grant ownership of a slave pseudo-terminal device to the
+ *             current user.
+ */
+
+int
+grantpt(int fildes)
+{
+	int retval, serrno, status;
+	pid_t pid, spid;
+	gid_t gid;
+	char *slave;
+	sigset_t oblock, nblock;
+	struct group *grp;
+
+	retval = -1;
+	serrno = errno;
+
+	if ((slave = ptsname(fildes)) != NULL) {
+		/*
+		 * Block SIGCHLD.
+		 */
+		(void)sigemptyset(&nblock);
+		(void)sigaddset(&nblock, SIGCHLD);
+		(void)_sigprocmask(SIG_BLOCK, &nblock, &oblock);
+
+		switch (pid = fork()) {
+		case -1:
+			break;
+		case 0:		/* child */
+			/*
+			 * pt_chown expects the master pseudo TTY to be its
+			 * standard input.
+			 */
+			(void)_dup2(fildes, STDIN_FILENO);
+			(void)_sigprocmask(SIG_SETMASK, &oblock, NULL);
+			execl(_PATH_PTCHOWN, _PATH_PTCHOWN, (char *)NULL);
+			_exit(EX_UNAVAILABLE);
+			/* NOTREACHED */
+		default:	/* parent */
+			/*
+			 * Just wait for the process.  Error checking is
+			 * done below.
+			 */
+			while ((spid = _waitpid(pid, &status, 0)) == -1 &&
+			       (errno == EINTR))
+				;
+			if (spid != -1 && WIFEXITED(status) &&
+			    WEXITSTATUS(status) == EX_OK)
+				retval = 0;
+			else
+				errno = EACCES;
+			break;
+		}
+
+		/*
+		 * Restore process's signal mask.
+		 */
+		(void)_sigprocmask(SIG_SETMASK, &oblock, NULL);
+
+		if (retval) {
+			/*
+			 * pt_chown failed.  Try to manually change the
+			 * permissions for the slave.
+			 */
+			gid = (grp = getgrnam("tty")) ? grp->gr_gid : -1;
+			if (chown(slave, getuid(), gid) == -1 ||
+			    chmod(slave, S_IRUSR | S_IWUSR | S_IWGRP) == -1)
+				errno = EACCES;
+			else
+				retval = 0;
+		}
+	}
+
+	if (!retval)
+		errno = serrno;
+
+	return (retval);
+}
+
+/*
+ * posix_openpt():  open the first available master pseudo-terminal device
+ *                  and return descriptor.
+ */
+int
+posix_openpt(int oflag)
+{
+	char *mc1, *mc2, master[] = _PATH_DEV PTYM_PREFIX "XY";
+	const char *pc1, *pc2;
+	int fildes, bflag, serrno;
+
+	fildes = -1;
+	bflag = 0;
+	serrno = errno;
+
+	/*
+	 * Check flag validity.  POSIX doesn't require it,
+	 * but we still do so.
+	 */
+	if (oflag & ~(O_RDWR | O_NOCTTY))
+		errno = EINVAL;
+	else {
+		if (__use_pts()) {
+			fildes = _open(_PATH_DEV PTMX, oflag);
+			return (fildes);
+		}
+		mc1 = master + strlen(_PATH_DEV PTYM_PREFIX);
+		mc2 = mc1 + 1;
+
+		/* Cycle through all possible master PTY devices. */
+		for (pc1 = PTY_DEV1; !bflag && (*mc1 = *pc1); ++pc1)
+			for (pc2 = PTY_DEV2; (*mc2 = *pc2) != '\0'; ++pc2) {
+				/*
+				 * Break out if we successfully open a PTY,
+				 * or if open() fails due to limits.
+				 */
+				if ((fildes = _open(master, oflag)) != -1 ||
+				    (errno == EMFILE || errno == ENFILE)) {
+					++bflag;
+					break;
+				}
+			}
+
+		if (fildes != -1)
+			errno = serrno;
+		else if (!bflag)
+			errno = EAGAIN;
+	}
+
+	return (fildes);
+}
+
+/*
+ * ptsname():  return the pathname of the slave pseudo-terminal device
+ *             associated with the specified master.
+ */
+char *
+ptsname(int fildes)
+{
+	static char pty_slave[] = _PATH_DEV PTYS_PREFIX "XY";
+	static char ptmx_slave[] = _PATH_DEV PTMXS_PREFIX "4294967295";
+	const char *master;
+	struct stat sbuf;
+	int ptn;
+
+	/* Handle pts(4) masters first. */
+	if (_ioctl(fildes, TIOCGPTN, &ptn) == 0) {
+		(void)snprintf(ptmx_slave, sizeof(ptmx_slave),
+		    _PATH_DEV PTMXS_PREFIX "%d", ptn);
+		return (ptmx_slave);
+	}
+
+	/* All master pty's must be char devices. */
+	if (_fstat(fildes, &sbuf) == -1)
+		goto invalid;
+	if (!S_ISCHR(sbuf.st_mode))
+		goto invalid;
+
+	/* Check to see if this device is a pty(4) master. */
+	master = devname(sbuf.st_rdev, S_IFCHR);
+	if (strlen(master) != strlen(PTYM_PREFIX "XY"))
+		goto invalid;
+	if (strncmp(master, PTYM_PREFIX, strlen(PTYM_PREFIX)) != 0)
+		goto invalid;
+
+	/* It is, so generate the corresponding pty(4) slave name. */
+	(void)snprintf(pty_slave, sizeof(pty_slave), _PATH_DEV PTYS_PREFIX "%s",
+	    master + strlen(PTYM_PREFIX));
+	return (pty_slave);
+
+invalid:
+	errno = EINVAL;
+	return (NULL);
+}
+
+/*
+ * unlockpt():  unlock a pseudo-terminal device pair.
+ */
+int
+unlockpt(int fildes)
+{
+
+	/*
+	 * Unlocking a master/slave pseudo-terminal pair has no meaning in a
+	 * non-streams PTY environment.  However, we do ensure fildes is a
+	 * valid master pseudo-terminal device.
+	 */
+	if (ptsname(fildes) == NULL)
+		return (-1);
+
+	return (0);
+}