This source file includes following definitions.
- pty_close
- pty_write
- pty_write_room
- pty_chars_in_buffer
- pty_flush_buffer
- pty_open
- pty_init
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15 #include <linux/errno.h>
16 #include <linux/sched.h>
17 #include <linux/interrupt.h>
18 #include <linux/tty.h>
19 #include <linux/tty_flip.h>
20 #include <linux/fcntl.h>
21 #include <linux/string.h>
22 #include <linux/major.h>
23 #include <linux/mm.h>
24
25 #include <asm/segment.h>
26 #include <asm/system.h>
27 #include <asm/bitops.h>
28
29 struct pty_struct {
30 int magic;
31 struct wait_queue * open_wait;
32 };
33
34 #define PTY_MAGIC 0x5001
35
36 #define PTY_BUF_SIZE PAGE_SIZE/2
37
38
39
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42
43
44
45
46
47 static unsigned char *tmp_buf;
48 static struct semaphore tmp_buf_sem = MUTEX;
49
50 struct tty_driver pty_driver, pty_slave_driver;
51 static int pty_refcount;
52
53 static struct tty_struct *pty_table[NR_PTYS];
54 static struct termios *pty_termios[NR_PTYS];
55 static struct termios *pty_termios_locked[NR_PTYS];
56 static struct tty_struct *ttyp_table[NR_PTYS];
57 static struct termios *ttyp_termios[NR_PTYS];
58 static struct termios *ttyp_termios_locked[NR_PTYS];
59 static struct pty_struct pty_state[NR_PTYS];
60
61 #define MIN(a,b) ((a) < (b) ? (a) : (b))
62
63 static void pty_close(struct tty_struct * tty, struct file * filp)
64 {
65 if (!tty)
66 return;
67 if (tty->driver.subtype == PTY_TYPE_MASTER) {
68 if (tty->count > 1)
69 printk("master pty_close: count = %d!!\n", tty->count);
70 } else {
71 if (tty->count > 2)
72 return;
73 }
74 wake_up_interruptible(&tty->read_wait);
75 wake_up_interruptible(&tty->write_wait);
76 if (!tty->link)
77 return;
78 wake_up_interruptible(&tty->link->read_wait);
79 wake_up_interruptible(&tty->link->write_wait);
80 if (tty->driver.subtype == PTY_TYPE_MASTER)
81 tty_hangup(tty->link);
82 else {
83 start_tty(tty);
84 set_bit(TTY_SLAVE_CLOSED, &tty->link->flags);
85 }
86 }
87
88 static int pty_write(struct tty_struct * tty, int from_user,
89 unsigned char *buf, int count)
90 {
91 struct tty_struct *to = tty->link;
92 int c=0, n, r;
93 char *temp_buffer;
94
95 if (!to || tty->stopped)
96 return 0;
97
98 if (from_user) {
99 down(&tmp_buf_sem);
100 temp_buffer = tmp_buf +
101 ((tty->driver.subtype-1) * PTY_BUF_SIZE);
102 while (count > 0) {
103 n = MIN(count, PTY_BUF_SIZE);
104 memcpy_fromfs(temp_buffer, buf, n);
105 r = to->ldisc.receive_room(to);
106 if (r <= 0)
107 break;
108 n = MIN(n, r);
109 to->ldisc.receive_buf(to, temp_buffer, 0, n);
110 buf += n; c+= n;
111 count -= n;
112 }
113 up(&tmp_buf_sem);
114 } else {
115 c = MIN(count, to->ldisc.receive_room(to));
116 to->ldisc.receive_buf(to, buf, 0, c);
117 }
118
119 return c;
120 }
121
122 static int pty_write_room(struct tty_struct *tty)
123 {
124 struct tty_struct *to = tty->link;
125
126 if (!to || tty->stopped)
127 return 0;
128
129 return to->ldisc.receive_room(to);
130 }
131
132 static int pty_chars_in_buffer(struct tty_struct *tty)
133 {
134 struct tty_struct *to = tty->link;
135
136 if (!to || !to->ldisc.chars_in_buffer)
137 return 0;
138
139 return to->ldisc.chars_in_buffer(to);
140 }
141
142 static void pty_flush_buffer(struct tty_struct *tty)
143 {
144 struct tty_struct *to = tty->link;
145
146 if (!to)
147 return;
148
149 if (to->ldisc.flush_buffer)
150 to->ldisc.flush_buffer(to);
151
152 if (to->packet) {
153 tty->ctrl_status |= TIOCPKT_FLUSHWRITE;
154 wake_up_interruptible(&to->read_wait);
155 }
156 }
157
158 int pty_open(struct tty_struct *tty, struct file * filp)
159 {
160 int line;
161 struct pty_struct *pty;
162
163 if (!tty || !tty->link)
164 return -ENODEV;
165 line = MINOR(tty->device) - tty->driver.minor_start;
166 if ((line < 0) || (line >= NR_PTYS))
167 return -ENODEV;
168 pty = pty_state + line;
169 tty->driver_data = pty;
170
171 if (!tmp_buf) {
172 tmp_buf = (unsigned char *) get_free_page(GFP_KERNEL);
173 if (!tmp_buf)
174 return -ENOMEM;
175 }
176
177 if (tty->driver.subtype == PTY_TYPE_SLAVE)
178 clear_bit(TTY_SLAVE_CLOSED, &tty->link->flags);
179 wake_up_interruptible(&pty->open_wait);
180 if (filp->f_flags & O_NDELAY)
181 return 0;
182 while (!tty->link->count && !(current->signal & ~current->blocked))
183 interruptible_sleep_on(&pty->open_wait);
184 if (!tty->link->count)
185 return -ERESTARTSYS;
186 return 0;
187 }
188
189 long pty_init(long kmem_start)
190 {
191 memset(&pty_state, 0, sizeof(pty_state));
192 memset(&pty_driver, 0, sizeof(struct tty_driver));
193 pty_driver.magic = TTY_DRIVER_MAGIC;
194 pty_driver.name = "pty";
195 pty_driver.major = TTY_MAJOR;
196 pty_driver.minor_start = 128;
197 pty_driver.num = NR_PTYS;
198 pty_driver.type = TTY_DRIVER_TYPE_PTY;
199 pty_driver.subtype = PTY_TYPE_MASTER;
200 pty_driver.init_termios = tty_std_termios;
201 pty_driver.init_termios.c_iflag = 0;
202 pty_driver.init_termios.c_oflag = 0;
203 pty_driver.init_termios.c_cflag = B9600 | CS8 | CREAD;
204 pty_driver.init_termios.c_lflag = 0;
205 pty_driver.flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW;
206 pty_driver.refcount = &pty_refcount;
207 pty_driver.table = pty_table;
208 pty_driver.termios = pty_termios;
209 pty_driver.termios_locked = pty_termios_locked;
210 pty_driver.other = &pty_slave_driver;
211
212 pty_driver.open = pty_open;
213 pty_driver.close = pty_close;
214 pty_driver.write = pty_write;
215 pty_driver.write_room = pty_write_room;
216 pty_driver.flush_buffer = pty_flush_buffer;
217 pty_driver.chars_in_buffer = pty_chars_in_buffer;
218
219 pty_slave_driver = pty_driver;
220 pty_slave_driver.name = "ttyp";
221 pty_slave_driver.subtype = PTY_TYPE_SLAVE;
222 pty_slave_driver.minor_start = 192;
223 pty_slave_driver.init_termios = tty_std_termios;
224 pty_slave_driver.table = ttyp_table;
225 pty_slave_driver.termios = ttyp_termios;
226 pty_slave_driver.termios_locked = ttyp_termios_locked;
227 pty_slave_driver.other = &pty_driver;
228
229 tmp_buf = 0;
230
231 if (tty_register_driver(&pty_driver))
232 panic("Couldn't register pty driver");
233 if (tty_register_driver(&pty_slave_driver))
234 panic("Couldn't register pty slave driver");
235
236 return kmem_start;
237 }