1/*-
2 * Copyright (c) 2008 Ed Schouten <ed@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Portions of this software were developed under sponsorship from Snow
6 * B.V., the Netherlands.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#include <sys/cdefs.h>
31__FBSDID("$FreeBSD: head/sys/kern/tty_pty.c 181905 2008-08-20 08:31:58Z ed $");
32
33#include <sys/param.h>
34#include <sys/conf.h>
35#include <sys/eventhandler.h>
36#include <sys/fcntl.h>
37#include <sys/kernel.h>
38#include <sys/proc.h>
39#include <sys/systm.h>
40#include <sys/tty.h>
41
42/*
43 * This driver implements a BSD-style compatibility naming scheme for
44 * the pts(4) driver. We just call into pts(4) to create the actual PTY.
45 * To make sure we don't use the same PTY multiple times, we abuse
46 * si_drv1 inside the cdev to mark whether the PTY is in use.
47 */
48
49static int pty_warningcnt = 10;
50
51static int
52ptydev_fdopen(struct cdev *dev, int fflags, struct thread *td, struct file *fp)
53{
54 int u, error;
55 char name[] = "ttyXX";
56
57 if (!atomic_cmpset_ptr((uintptr_t *)&dev->si_drv1, 0, 1))
58 return (EBUSY);
59
60 /* Generate device name and create PTY. */
61 u = dev2unit(dev);
62 name[3] = u >> 8;
63 name[4] = u;
64
65 error = pts_alloc_external(fflags & (FREAD|FWRITE), td, fp, dev, name);
66 if (error != 0) {
67 destroy_dev_sched(dev);
68 return (error);
69 }
70
71 /* Raise a warning when a legacy PTY has been allocated. */
72 if (pty_warningcnt > 0) {
73 pty_warningcnt--;
74 printf("pid %d (%s) is using legacy pty devices%s\n",
75 td->td_proc->p_pid, td->td_name,
76 pty_warningcnt ? "" : " - not logging anymore");
77 }
78
79 return (0);
80}
81
82static struct cdevsw ptydev_cdevsw = {
83 .d_version = D_VERSION,
84 .d_fdopen = ptydev_fdopen,
85 .d_name = "ptydev",
86};
87
88static void
89pty_clone(void *arg, struct ucred *cr, char *name, int namelen,
90 struct cdev **dev)
91{
92 int u;
93
94 /* Cloning is already satisfied. */
95 if (*dev != NULL)
96 return;
97
98 /* Only catch /dev/ptyXX. */
99 if (namelen != 5 || bcmp(name, "pty", 3) != 0)
100 return;
101
102 /* Only catch /dev/pty[l-sL-S]X. */
103 if (!(name[3] >= 'l' && name[3] <= 's') &&
104 !(name[3] >= 'L' && name[3] <= 'S'))
105 return;
106
107 /* Only catch /dev/pty[l-sL-S][0-9a-v]. */
108 if (!(name[4] >= '0' && name[4] <= '9') &&
109 !(name[4] >= 'a' && name[4] <= 'v'))
110 return;
111
112 /* Create the controller device node. */
113 u = (unsigned int)name[3] << 8 | name[4];
114 *dev = make_dev_credf(MAKEDEV_REF, &ptydev_cdevsw, u,
115 NULL, UID_ROOT, GID_WHEEL, 0666, name);
116}
117
118static void
119pty_init(void *unused)
120{
121
122 EVENTHANDLER_REGISTER(dev_clone, pty_clone, 0, 1000);
123}
124
125SYSINIT(pty, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, pty_init, NULL);
2 * Copyright (c) 2008 Ed Schouten <ed@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Portions of this software were developed under sponsorship from Snow
6 * B.V., the Netherlands.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#include <sys/cdefs.h>
31__FBSDID("$FreeBSD: head/sys/kern/tty_pty.c 181905 2008-08-20 08:31:58Z ed $");
32
33#include <sys/param.h>
34#include <sys/conf.h>
35#include <sys/eventhandler.h>
36#include <sys/fcntl.h>
37#include <sys/kernel.h>
38#include <sys/proc.h>
39#include <sys/systm.h>
40#include <sys/tty.h>
41
42/*
43 * This driver implements a BSD-style compatibility naming scheme for
44 * the pts(4) driver. We just call into pts(4) to create the actual PTY.
45 * To make sure we don't use the same PTY multiple times, we abuse
46 * si_drv1 inside the cdev to mark whether the PTY is in use.
47 */
48
49static int pty_warningcnt = 10;
50
51static int
52ptydev_fdopen(struct cdev *dev, int fflags, struct thread *td, struct file *fp)
53{
54 int u, error;
55 char name[] = "ttyXX";
56
57 if (!atomic_cmpset_ptr((uintptr_t *)&dev->si_drv1, 0, 1))
58 return (EBUSY);
59
60 /* Generate device name and create PTY. */
61 u = dev2unit(dev);
62 name[3] = u >> 8;
63 name[4] = u;
64
65 error = pts_alloc_external(fflags & (FREAD|FWRITE), td, fp, dev, name);
66 if (error != 0) {
67 destroy_dev_sched(dev);
68 return (error);
69 }
70
71 /* Raise a warning when a legacy PTY has been allocated. */
72 if (pty_warningcnt > 0) {
73 pty_warningcnt--;
74 printf("pid %d (%s) is using legacy pty devices%s\n",
75 td->td_proc->p_pid, td->td_name,
76 pty_warningcnt ? "" : " - not logging anymore");
77 }
78
79 return (0);
80}
81
82static struct cdevsw ptydev_cdevsw = {
83 .d_version = D_VERSION,
84 .d_fdopen = ptydev_fdopen,
85 .d_name = "ptydev",
86};
87
88static void
89pty_clone(void *arg, struct ucred *cr, char *name, int namelen,
90 struct cdev **dev)
91{
92 int u;
93
94 /* Cloning is already satisfied. */
95 if (*dev != NULL)
96 return;
97
98 /* Only catch /dev/ptyXX. */
99 if (namelen != 5 || bcmp(name, "pty", 3) != 0)
100 return;
101
102 /* Only catch /dev/pty[l-sL-S]X. */
103 if (!(name[3] >= 'l' && name[3] <= 's') &&
104 !(name[3] >= 'L' && name[3] <= 'S'))
105 return;
106
107 /* Only catch /dev/pty[l-sL-S][0-9a-v]. */
108 if (!(name[4] >= '0' && name[4] <= '9') &&
109 !(name[4] >= 'a' && name[4] <= 'v'))
110 return;
111
112 /* Create the controller device node. */
113 u = (unsigned int)name[3] << 8 | name[4];
114 *dev = make_dev_credf(MAKEDEV_REF, &ptydev_cdevsw, u,
115 NULL, UID_ROOT, GID_WHEEL, 0666, name);
116}
117
118static void
119pty_init(void *unused)
120{
121
122 EVENTHANDLER_REGISTER(dev_clone, pty_clone, 0, 1000);
123}
124
125SYSINIT(pty, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, pty_init, NULL);