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1.1 root 1: /* bk.c 4.2 11/9/80 */
2:
3: #include "../h/param.h"
4: #include "../h/systm.h"
5: #include "../h/dir.h"
6: #include "../h/user.h"
7: #include "../h/tty.h"
8: #include "../h/proc.h"
9: #include "../h/mx.h"
10: #include "../h/inode.h"
11: #include "../h/file.h"
12: #include "../h/conf.h"
13: #include "../h/buf.h"
14:
15: /*
16: * When running dz's using only SAE (silo alarm) on input
17: * it is necessary to call dzrint() at clock interrupt time.
18: * This is unsafe unless spl5()s in tty code are changed to
19: * spl6()s to block clock interrupts. Note that the dh driver
20: * currently in use works the same way as the dz, even though
21: * we could try to more intelligently manage its silo.
22: * Thus don't take this out if you have no dz's unless you
23: * change clock.c and dhtimer().
24: */
25: #define spl5 spl6
26:
27: /*
28: * Line discipline for Berkeley network.
29: *
30: * This supplies single lines to a user level program
31: * with a minimum of fuss. Lines are newline terminated.
32: * A later version will implement full 8-bit paths by providing
33: * an escape sequence to include a newline in a record.
34: *
35: * This discipline requires that tty device drivers call
36: * the line specific l_ioctl routine from their ioctl routines,
37: * assigning the result to cmd so that we can refuse most tty specific
38: * ioctls which are unsafe because we have ambushed the
39: * teletype input queues, overlaying them with other information.
40: */
41:
42: /*
43: * Open as networked discipline. Called when discipline changed
44: * with ioctl, this assigns a buffer to the line for input, and
45: * changing the interpretation of the information in the tty structure.
46: */
47: /*ARGSUSED*/
48: bkopen(dev, tp)
49: dev_t dev;
50: register struct tty *tp;
51: {
52: register struct buf *bp;
53:
54: if (u.u_error)
55: return; /* paranoia */
56: if (tp->t_line == NETLDISC) {
57: u.u_error = EBUSY; /* sometimes the network */
58: return; /* ... opens /dev/tty */
59: }
60: bp = geteblk();
61: flushtty(tp, FREAD|FWRITE);
62: tp->t_bufp = bp;
63: tp->t_cp = (char *)bp->b_un.b_addr;
64: tp->t_inbuf = 0;
65: tp->t_rec = 0;
66: }
67:
68: /*
69: * Break down... called when discipline changed or from device
70: * close routine.
71: */
72: bkclose(tp)
73: register struct tty *tp;
74: {
75: register s;
76:
77: s = spl5();
78: wakeup((caddr_t)&tp->t_rawq);
79: if (tp->t_bufp) {
80: brelse(tp->t_bufp);
81: tp->t_bufp = 0;
82: } else
83: printf("bkclose: no buf\n");
84: tp->t_cp = 0;
85: tp->t_inbuf = 0;
86: tp->t_rec = 0;
87: tp->t_line = 0; /* paranoid: avoid races */
88: splx(s);
89: }
90:
91: /*
92: * Read from a network line.
93: * Characters have been buffered in a system buffer and are
94: * now dumped back to the user in one fell swoop, and with a
95: * minimum of fuss. Note that no input is accepted when a record
96: * is waiting. Our clearing tp->t_rec here allows further input
97: * to accumulate.
98: */
99: bkread(tp)
100: register struct tty *tp;
101: {
102: register int i;
103: register s;
104:
105: if ((tp->t_state&CARR_ON)==0)
106: return (-1);
107: s = spl5();
108: while (tp->t_rec == 0 && tp->t_line == NETLDISC)
109: sleep((caddr_t)&tp->t_rawq, TTIPRI);
110: splx(s);
111: if (tp->t_line != NETLDISC)
112: return (-1);
113: i = MIN(tp->t_inbuf, (int)u.u_count);
114: if (copyout(tp->t_bufp->b_un.b_addr, u.u_base, (unsigned)i)) {
115: u.u_error = EFAULT;
116: return (-1);
117: }
118: u.u_count -= i;
119: u.u_base += i;
120: u.u_offset += i;
121: tp->t_cp = (char *)tp->t_bufp->b_un.b_addr;
122: tp->t_inbuf = 0;
123: tp->t_rec = 0;
124: return (0);
125: }
126:
127: /*
128: * Low level character input routine.
129: * Stuff the character in the buffer, and wake up the top
130: * half after setting t_rec if this completes the record
131: * or if the buffer is (ick!) full.
132: *
133: * Thisis where the formatting should get done to allow
134: * 8 character data paths through escapes.
135: *
136: * This rutine should be expanded in-line in the receiver
137: * interrupt routine of the dh-11 to make it run as fast as possible.
138: */
139: bkinput(c, tp)
140: register c;
141: register struct tty *tp;
142: {
143:
144: if (tp->t_rec)
145: return;
146: *tp->t_cp++ = c;
147: if (++tp->t_inbuf == BSIZE || c == '\n') {
148: tp->t_rec = 1;
149: wakeup((caddr_t)&tp->t_rawq);
150: }
151: }
152:
153: /*
154: * This routine is called whenever a ioctl is about to be performed
155: * and gets a chance to reject the ioctl. We reject all teletype
156: * oriented ioctl's except those which set the discipline, and
157: * those which get parameters (gtty and get special characters).
158: */
159: /*ARGSUSED*/
160: bkioctl(tp, cmd, addr)
161: struct tty *tp;
162: caddr_t addr;
163: {
164:
165: if ((cmd>>8) != 't')
166: return (cmd);
167: switch (cmd) {
168:
169: case TIOCSETD:
170: case TIOCGETD:
171: case TIOCGETP:
172: case TIOCGETC:
173: return (cmd);
174: }
175: u.u_error = ENOTTY;
176: return (0);
177: }
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