1 files changed, 141 insertions, 0 deletions
diff --git a/sys/dev/pty/pty.c b/sys/dev/pty/pty.c
new file mode 100644
index 0000000..d3dce9f
--- /dev/null
+++ b/sys/dev/pty/pty.c
@@ -0,0 +1,141 @@
+/*-
+ * Copyright (c) 2008 Ed Schouten <ed@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Portions of this software were developed under sponsorship from Snow
+ * B.V., the Netherlands.
+ *
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR OR 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>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/conf.h>
+#include <sys/eventhandler.h>
+#include <sys/fcntl.h>
+#include <sys/kernel.h>
+#include <sys/module.h>
+#include <sys/proc.h>
+#include <sys/sysctl.h>
+#include <sys/syslog.h>
+#include <sys/systm.h>
+#include <sys/tty.h>
+
+/*
+ * This driver implements a BSD-style compatibility naming scheme for
+ * the pts(4) driver. We just call into pts(4) to create the actual PTY.
+ * To make sure we don't use the same PTY multiple times, we abuse
+ * si_drv1 inside the cdev to mark whether the PTY is in use.
+ */
+
+static unsigned int pty_warningcnt = 1;
+SYSCTL_UINT(_kern, OID_AUTO, tty_pty_warningcnt, CTLFLAG_RW,
+	&pty_warningcnt, 0,
+	"Warnings that will be triggered upon legacy PTY allocation");
+
+static int
+ptydev_fdopen(struct cdev *dev, int fflags, struct thread *td, struct file *fp)
+{
+	int error;
+	char name[6]; /* "ttyXX" */
+
+	if (!atomic_cmpset_ptr((uintptr_t *)&dev->si_drv1, 0, 1))
+		return (EBUSY);
+
+	/* Generate device name and create PTY. */
+	strcpy(name, devtoname(dev));
+	name[0] = 't';
+
+	error = pts_alloc_external(fflags & (FREAD|FWRITE), td, fp, dev, name);
+	if (error != 0) {
+		destroy_dev_sched(dev);
+		return (error);
+	}
+
+	/* Raise a warning when a legacy PTY has been allocated. */
+	if (pty_warningcnt > 0) {
+		pty_warningcnt--;
+		log(LOG_INFO, "pid %d (%s) is using legacy pty devices%s\n", 
+		    td->td_proc->p_pid, td->td_name,
+		    pty_warningcnt ? "" : " - not logging anymore");
+	}
+
+	return (0);
+}
+
+static struct cdevsw ptydev_cdevsw = {
+	.d_version	= D_VERSION,
+	.d_fdopen	= ptydev_fdopen,
+	.d_name		= "ptydev",
+};
+
+static void
+pty_clone(void *arg, struct ucred *cr, char *name, int namelen,
+    struct cdev **dev)
+{
+
+	/* Cloning is already satisfied. */
+	if (*dev != NULL)
+		return;
+
+	/* Only catch /dev/ptyXX. */
+	if (namelen != 5 || bcmp(name, "pty", 3) != 0)
+		return;
+
+	/* Only catch /dev/pty[l-sL-S]X. */
+	if (!(name[3] >= 'l' && name[3] <= 's') &&
+	    !(name[3] >= 'L' && name[3] <= 'S'))
+		return;
+
+	/* Only catch /dev/pty[l-sL-S][0-9a-v]. */
+	if (!(name[4] >= '0' && name[4] <= '9') &&
+	    !(name[4] >= 'a' && name[4] <= 'v'))
+		return;
+
+	/* Create the controller device node. */
+	*dev = make_dev_credf(MAKEDEV_REF, &ptydev_cdevsw, 0,
+	    NULL, UID_ROOT, GID_WHEEL, 0666, "%s", name);
+}
+
+static int
+pty_modevent(module_t mod, int type, void *data)
+{
+
+        switch(type) {
+        case MOD_LOAD: 
+		EVENTHANDLER_REGISTER(dev_clone, pty_clone, 0, 1000);
+		break;
+	case MOD_SHUTDOWN:
+		break;
+	case MOD_UNLOAD:
+		/* XXX: No unloading support yet. */
+		return (EBUSY);
+	default:
+		return (EOPNOTSUPP);
+	}
+
+	return (0);
+}
+
+DEV_MODULE(pty, pty_modevent, NULL);