1 /*- 2 * Copyright (c) 1982, 1986, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 * 7 * @(#)tty_tty.c 8.3 (Berkeley) 01/09/95 8 */ 9 10 /* 11 * Indirect driver for controlling tty. 12 */ 13 #include <sys/param.h> 14 #include <sys/systm.h> 15 #include <sys/conf.h> 16 #include <sys/ioctl.h> 17 #include <sys/proc.h> 18 #include <sys/tty.h> 19 #include <sys/vnode.h> 20 #include <sys/file.h> 21 22 #define cttyvp(p) ((p)->p_flag & P_CONTROLT ? (p)->p_session->s_ttyvp : NULL) 23 24 /*ARGSUSED*/ 25 cttyopen(dev, flag, mode, p) 26 dev_t dev; 27 int flag, mode; 28 struct proc *p; 29 { 30 struct vnode *ttyvp = cttyvp(p); 31 int error; 32 33 if (ttyvp == NULL) 34 return (ENXIO); 35 VOP_LOCK(ttyvp); 36 #ifdef PARANOID 37 /* 38 * Since group is tty and mode is 620 on most terminal lines 39 * and since sessions protect terminals from processes outside 40 * your session, this check is probably no longer necessary. 41 * Since it inhibits setuid root programs that later switch 42 * to another user from accessing /dev/tty, we have decided 43 * to delete this test. (mckusick 5/93) 44 */ 45 error = VOP_ACCESS(ttyvp, 46 (flag&FREAD ? VREAD : 0) | (flag&FWRITE ? VWRITE : 0), p->p_ucred, p); 47 if (!error) 48 #endif /* PARANOID */ 49 error = VOP_OPEN(ttyvp, flag, NOCRED, p); 50 VOP_UNLOCK(ttyvp); 51 return (error); 52 } 53 54 /*ARGSUSED*/ 55 cttyread(dev, uio, flag) 56 dev_t dev; 57 struct uio *uio; 58 int flag; 59 { 60 register struct vnode *ttyvp = cttyvp(uio->uio_procp); 61 int error; 62 63 if (ttyvp == NULL) 64 return (EIO); 65 VOP_LOCK(ttyvp); 66 error = VOP_READ(ttyvp, uio, flag, NOCRED); 67 VOP_UNLOCK(ttyvp); 68 return (error); 69 } 70 71 /*ARGSUSED*/ 72 cttywrite(dev, uio, flag) 73 dev_t dev; 74 struct uio *uio; 75 int flag; 76 { 77 register struct vnode *ttyvp = cttyvp(uio->uio_procp); 78 int error; 79 80 if (ttyvp == NULL) 81 return (EIO); 82 VOP_LOCK(ttyvp); 83 error = VOP_WRITE(ttyvp, uio, flag, NOCRED); 84 VOP_UNLOCK(ttyvp); 85 return (error); 86 } 87 88 /*ARGSUSED*/ 89 cttyioctl(dev, cmd, addr, flag, p) 90 dev_t dev; 91 u_long cmd; 92 caddr_t addr; 93 int flag; 94 struct proc *p; 95 { 96 struct vnode *ttyvp = cttyvp(p); 97 98 if (ttyvp == NULL) 99 return (EIO); 100 if (cmd == TIOCNOTTY) { 101 if (!SESS_LEADER(p)) { 102 p->p_flag &= ~P_CONTROLT; 103 return (0); 104 } else 105 return (EINVAL); 106 } 107 return (VOP_IOCTL(ttyvp, cmd, addr, flag, NOCRED, p)); 108 } 109 110 /*ARGSUSED*/ 111 cttyselect(dev, flag, p) 112 dev_t dev; 113 int flag; 114 struct proc *p; 115 { 116 struct vnode *ttyvp = cttyvp(p); 117 118 if (ttyvp == NULL) 119 return (1); /* try operation to get EOF/failure */ 120 return (VOP_SELECT(ttyvp, flag, FREAD|FWRITE, NOCRED, p)); 121 } 122