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33 * @(#)tty_tty.c 8.2 (Berkeley) 9/23/93
34 * $FreeBSD: src/sys/kern/tty_tty.c,v 1.30 1999/09/25 18:24:24 phk Exp $
35 * $DragonFly: src/sys/kern/tty_tty.c,v 1.6 2003/08/26 21:09:02 rob Exp $
39 * Indirect driver for controlling tty.
42 #include <sys/param.h>
43 #include <sys/systm.h>
47 #include <sys/ttycom.h>
48 #include <sys/vnode.h>
49 #include <sys/kernel.h>
51 static d_open_t cttyopen;
52 static d_read_t cttyread;
53 static d_write_t cttywrite;
54 static d_ioctl_t cttyioctl;
55 static d_poll_t cttypoll;
58 /* Don't make this static, since fdesc_vnops uses it. */
59 struct cdevsw ctty_cdevsw = {
67 /* close */ nullclose,
69 /* write */ cttywrite,
70 /* ioctl */ cttyioctl,
73 /* strategy */ nostrategy,
78 #define cttyvp(p) ((p)->p_flag & P_CONTROLT ? (p)->p_session->s_ttyvp : NULL)
82 cttyopen(dev_t dev, int flag, int mode, struct thread *td)
84 struct proc *p = td->td_proc;
93 vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, td);
96 * Since group is tty and mode is 620 on most terminal lines
97 * and since sessions protect terminals from processes outside
98 * your session, this check is probably no longer necessary.
99 * Since it inhibits setuid root programs that later switch
100 * to another user from accessing /dev/tty, we have decided
101 * to delete this test. (mckusick 5/93)
103 error = VOP_ACCESS(ttyvp,
104 (flag&FREAD ? VREAD : 0) | (flag&FWRITE ? VWRITE : 0), p->p_ucred, td);
106 #endif /* PARANOID */
107 error = VOP_OPEN(ttyvp, flag, NOCRED, td);
108 VOP_UNLOCK(ttyvp, 0, td);
114 cttyread(dev, uio, flag)
119 struct thread *td = uio->uio_td;
120 struct proc *p = td->td_proc;
128 vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, td);
129 error = VOP_READ(ttyvp, uio, flag, NOCRED);
130 VOP_UNLOCK(ttyvp, 0, td);
136 cttywrite(dev, uio, flag)
141 struct thread *td = uio->uio_td;
142 struct proc *p = td->td_proc;
150 vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, td);
151 error = VOP_WRITE(ttyvp, uio, flag, NOCRED);
152 VOP_UNLOCK(ttyvp, 0, td);
158 cttyioctl(dev, cmd, addr, flag, td)
166 struct proc *p = td->td_proc;
172 if (cmd == TIOCSCTTY) /* don't allow controlling tty to be set */
173 return EINVAL; /* to controlling tty -- infinite recursion */
174 if (cmd == TIOCNOTTY) {
175 if (!SESS_LEADER(p)) {
176 p->p_flag &= ~P_CONTROLT;
181 return (VOP_IOCTL(ttyvp, cmd, addr, flag, NOCRED, td));
186 cttypoll(dev_t dev, int events, struct thread *td)
189 struct proc *p = td->td_proc;
194 /* try operation to get EOF/failure */
195 return (seltrue(dev, events, td));
196 return (VOP_POLL(ttyvp, events, p->p_ucred, td));
199 static void ctty_drvinit (void *unused);
205 make_dev(&ctty_cdevsw, 0, 0, 0, 0666, "tty");
208 SYSINIT(cttydev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,ctty_drvinit,NULL)