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 182069 2008-08-23 16:03:00Z 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/sysctl.h>
40#include <sys/systm.h>
41#include <sys/tty.h>
42
43/*
44 * This driver implements a BSD-style compatibility naming scheme for
45 * the pts(4) driver. We just call into pts(4) to create the actual PTY.
46 * To make sure we don't use the same PTY multiple times, we abuse
47 * si_drv1 inside the cdev to mark whether the PTY is in use.
48 */
49
50static unsigned int pty_warningcnt = 10;
51SYSCTL_UINT(_kern, OID_AUTO, tty_pty_warningcnt, CTLFLAG_RW,
52 &pty_warningcnt, 0,
53 "Warnings that will be triggered upon PTY allocation");
54
55static int
56ptydev_fdopen(struct cdev *dev, int fflags, struct thread *td, struct file *fp)
57{
58 int u, error;
59 char name[] = "ttyXX";
60
61 if (!atomic_cmpset_ptr((uintptr_t *)&dev->si_drv1, 0, 1))
62 return (EBUSY);
63
64 /* Generate device name and create PTY. */
65 u = dev2unit(dev);
66 name[3] = u >> 8;
67 name[4] = u;
68
69 error = pts_alloc_external(fflags & (FREAD|FWRITE), td, fp, dev, name);
70 if (error != 0) {
71 destroy_dev_sched(dev);
72 return (error);
73 }
74
75 /* Raise a warning when a legacy PTY has been allocated. */
76 if (pty_warningcnt > 0) {
77 pty_warningcnt--;
78 printf("pid %d (%s) is using legacy pty devices%s\n",
79 td->td_proc->p_pid, td->td_name,
80 pty_warningcnt ? "" : " - not logging anymore");
81 }
82
83 return (0);
84}
85
86static struct cdevsw ptydev_cdevsw = {
87 .d_version = D_VERSION,
88 .d_fdopen = ptydev_fdopen,
89 .d_name = "ptydev",
90};
91
92static void
93pty_clone(void *arg, struct ucred *cr, char *name, int namelen,
94 struct cdev **dev)
95{
96 int u;
97
98 /* Cloning is already satisfied. */
99 if (*dev != NULL)
100 return;
101
102 /* Only catch /dev/ptyXX. */
103 if (namelen != 5 || bcmp(name, "pty", 3) != 0)
104 return;
105
106 /* Only catch /dev/pty[l-sL-S]X. */
107 if (!(name[3] >= 'l' && name[3] <= 's') &&
108 !(name[3] >= 'L' && name[3] <= 'S'))
109 return;
110
111 /* Only catch /dev/pty[l-sL-S][0-9a-v]. */
112 if (!(name[4] >= '0' && name[4] <= '9') &&
113 !(name[4] >= 'a' && name[4] <= 'v'))
114 return;
115
116 /* Create the controller device node. */
117 u = (unsigned int)name[3] << 8 | name[4];
118 *dev = make_dev_credf(MAKEDEV_REF, &ptydev_cdevsw, u,
119 NULL, UID_ROOT, GID_WHEEL, 0666, name);
120}
121
122static void
123pty_init(void *unused)
124{
125
126 EVENTHANDLER_REGISTER(dev_clone, pty_clone, 0, 1000);
127}
128
129SYSINIT(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 182069 2008-08-23 16:03:00Z 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/sysctl.h>
40#include <sys/systm.h>
41#include <sys/tty.h>
42
43/*
44 * This driver implements a BSD-style compatibility naming scheme for
45 * the pts(4) driver. We just call into pts(4) to create the actual PTY.
46 * To make sure we don't use the same PTY multiple times, we abuse
47 * si_drv1 inside the cdev to mark whether the PTY is in use.
48 */
49
50static unsigned int pty_warningcnt = 10;
51SYSCTL_UINT(_kern, OID_AUTO, tty_pty_warningcnt, CTLFLAG_RW,
52 &pty_warningcnt, 0,
53 "Warnings that will be triggered upon PTY allocation");
54
55static int
56ptydev_fdopen(struct cdev *dev, int fflags, struct thread *td, struct file *fp)
57{
58 int u, error;
59 char name[] = "ttyXX";
60
61 if (!atomic_cmpset_ptr((uintptr_t *)&dev->si_drv1, 0, 1))
62 return (EBUSY);
63
64 /* Generate device name and create PTY. */
65 u = dev2unit(dev);
66 name[3] = u >> 8;
67 name[4] = u;
68
69 error = pts_alloc_external(fflags & (FREAD|FWRITE), td, fp, dev, name);
70 if (error != 0) {
71 destroy_dev_sched(dev);
72 return (error);
73 }
74
75 /* Raise a warning when a legacy PTY has been allocated. */
76 if (pty_warningcnt > 0) {
77 pty_warningcnt--;
78 printf("pid %d (%s) is using legacy pty devices%s\n",
79 td->td_proc->p_pid, td->td_name,
80 pty_warningcnt ? "" : " - not logging anymore");
81 }
82
83 return (0);
84}
85
86static struct cdevsw ptydev_cdevsw = {
87 .d_version = D_VERSION,
88 .d_fdopen = ptydev_fdopen,
89 .d_name = "ptydev",
90};
91
92static void
93pty_clone(void *arg, struct ucred *cr, char *name, int namelen,
94 struct cdev **dev)
95{
96 int u;
97
98 /* Cloning is already satisfied. */
99 if (*dev != NULL)
100 return;
101
102 /* Only catch /dev/ptyXX. */
103 if (namelen != 5 || bcmp(name, "pty", 3) != 0)
104 return;
105
106 /* Only catch /dev/pty[l-sL-S]X. */
107 if (!(name[3] >= 'l' && name[3] <= 's') &&
108 !(name[3] >= 'L' && name[3] <= 'S'))
109 return;
110
111 /* Only catch /dev/pty[l-sL-S][0-9a-v]. */
112 if (!(name[4] >= '0' && name[4] <= '9') &&
113 !(name[4] >= 'a' && name[4] <= 'v'))
114 return;
115
116 /* Create the controller device node. */
117 u = (unsigned int)name[3] << 8 | name[4];
118 *dev = make_dev_credf(MAKEDEV_REF, &ptydev_cdevsw, u,
119 NULL, UID_ROOT, GID_WHEEL, 0666, name);
120}
121
122static void
123pty_init(void *unused)
124{
125
126 EVENTHANDLER_REGISTER(dev_clone, pty_clone, 0, 1000);
127}
128
129SYSINIT(pty, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, pty_init, NULL);