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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 1.3 2003/06/23 17:55:41 dillon 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 = {
61 /* close */ nullclose,
63 /* write */ cttywrite,
64 /* ioctl */ cttyioctl,
67 /* strategy */ nostrategy,
76 #define cttyvp(p) ((p)->p_flag & P_CONTROLT ? (p)->p_session->s_ttyvp : NULL)
80 cttyopen(dev, flag, mode, td)
88 KKASSERT(td->td_proc != NULL);
89 ttyvp = cttyvp(td->td_proc);
93 vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, td->td_proc);
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, p);
106 #endif /* PARANOID */
107 error = VOP_OPEN(ttyvp, flag, NOCRED, td->td_proc);
108 VOP_UNLOCK(ttyvp, 0, td->td_proc);
114 cttyread(dev, uio, flag)
119 struct proc *p = uio->uio_procp;
120 register struct vnode *ttyvp = cttyvp(p);
125 vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, p);
126 error = VOP_READ(ttyvp, uio, flag, NOCRED);
127 VOP_UNLOCK(ttyvp, 0, p);
133 cttywrite(dev, uio, flag)
138 struct proc *p = uio->uio_procp;
139 struct vnode *ttyvp = cttyvp(uio->uio_procp);
144 vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, p);
145 error = VOP_WRITE(ttyvp, uio, flag, NOCRED);
146 VOP_UNLOCK(ttyvp, 0, p);
152 cttyioctl(dev, cmd, addr, flag, td)
161 KKASSERT(td->td_proc != NULL);
162 ttyvp = cttyvp(td->td_proc);
165 if (cmd == TIOCSCTTY) /* don't allow controlling tty to be set */
166 return EINVAL; /* to controlling tty -- infinite recursion */
167 if (cmd == TIOCNOTTY) {
168 if (!SESS_LEADER(td->td_proc)) {
169 td->td_proc->p_flag &= ~P_CONTROLT;
174 return (VOP_IOCTL(ttyvp, cmd, addr, flag, NOCRED, td->td_proc));
179 cttypoll(dev, events, td)
186 KKASSERT(td->td_proc != NULL);
187 ttyvp = cttyvp(td->td_proc);
189 /* try operation to get EOF/failure */
190 return (seltrue(dev, events, td));
191 return (VOP_POLL(ttyvp, events, td->td_proc->p_ucred, td->td_proc));
194 static void ctty_drvinit __P((void *unused));
200 make_dev(&ctty_cdevsw, 0, 0, 0, 0666, "tty");
203 SYSINIT(cttydev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,ctty_drvinit,NULL)