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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 1.2 2003/06/17 04:28:41 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, p)
85 struct vnode *ttyvp = cttyvp(p);
90 vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, p);
93 * Since group is tty and mode is 620 on most terminal lines
94 * and since sessions protect terminals from processes outside
95 * your session, this check is probably no longer necessary.
96 * Since it inhibits setuid root programs that later switch
97 * to another user from accessing /dev/tty, we have decided
98 * to delete this test. (mckusick 5/93)
100 error = VOP_ACCESS(ttyvp,
101 (flag&FREAD ? VREAD : 0) | (flag&FWRITE ? VWRITE : 0), p->p_ucred, p);
103 #endif /* PARANOID */
104 error = VOP_OPEN(ttyvp, flag, NOCRED, p);
105 VOP_UNLOCK(ttyvp, 0, p);
111 cttyread(dev, uio, flag)
116 struct proc *p = uio->uio_procp;
117 register struct vnode *ttyvp = cttyvp(p);
122 vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, p);
123 error = VOP_READ(ttyvp, uio, flag, NOCRED);
124 VOP_UNLOCK(ttyvp, 0, p);
130 cttywrite(dev, uio, flag)
135 struct proc *p = uio->uio_procp;
136 struct vnode *ttyvp = cttyvp(uio->uio_procp);
141 vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, p);
142 error = VOP_WRITE(ttyvp, uio, flag, NOCRED);
143 VOP_UNLOCK(ttyvp, 0, p);
149 cttyioctl(dev, cmd, addr, flag, p)
156 struct vnode *ttyvp = cttyvp(p);
160 if (cmd == TIOCSCTTY) /* don't allow controlling tty to be set */
161 return EINVAL; /* to controlling tty -- infinite recursion */
162 if (cmd == TIOCNOTTY) {
163 if (!SESS_LEADER(p)) {
164 p->p_flag &= ~P_CONTROLT;
169 return (VOP_IOCTL(ttyvp, cmd, addr, flag, NOCRED, p));
174 cttypoll(dev, events, p)
179 struct vnode *ttyvp = cttyvp(p);
182 /* try operation to get EOF/failure */
183 return (seltrue(dev, events, p));
184 return (VOP_POLL(ttyvp, events, p->p_ucred, p));
187 static void ctty_drvinit __P((void *unused));
193 make_dev(&ctty_cdevsw, 0, 0, 0, 0666, "tty");
196 SYSINIT(cttydev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,ctty_drvinit,NULL)