File: /usr/src/linux/fs/proc/proc_tty.c
1 /*
2 * proc_tty.c -- handles /proc/tty
3 *
4 * Copyright 1997, Theodore Ts'o
5 */
6
7 #include <asm/uaccess.h>
8
9 #include <linux/init.h>
10 #include <linux/errno.h>
11 #include <linux/sched.h>
12 #include <linux/proc_fs.h>
13 #include <linux/stat.h>
14 #include <linux/tty.h>
15 #include <asm/bitops.h>
16
17 extern struct tty_driver *tty_drivers; /* linked list of tty drivers */
18 extern struct tty_ldisc ldiscs[];
19
20
21 static int tty_drivers_read_proc(char *page, char **start, off_t off,
22 int count, int *eof, void *data);
23 static int tty_ldiscs_read_proc(char *page, char **start, off_t off,
24 int count, int *eof, void *data);
25
26 /*
27 * The /proc/tty directory inodes...
28 */
29 static struct proc_dir_entry *proc_tty_ldisc, *proc_tty_driver;
30
31 /*
32 * This is the handler for /proc/tty/drivers
33 */
34 static int tty_drivers_read_proc(char *page, char **start, off_t off,
35 int count, int *eof, void *data)
36 {
37 int len = 0;
38 off_t begin = 0;
39 struct tty_driver *p;
40 char range[20], deftype[20];
41 char *type;
42
43 for (p = tty_drivers; p; p = p->next) {
44 if (p->num > 1)
45 sprintf(range, "%d-%d", p->minor_start,
46 p->minor_start + p->num - 1);
47 else
48 sprintf(range, "%d", p->minor_start);
49 switch (p->type) {
50 case TTY_DRIVER_TYPE_SYSTEM:
51 if (p->subtype == SYSTEM_TYPE_TTY)
52 type = "system:/dev/tty";
53 else if (p->subtype == SYSTEM_TYPE_SYSCONS)
54 type = "system:console";
55 else if (p->subtype == SYSTEM_TYPE_CONSOLE)
56 type = "system:vtmaster";
57 else
58 type = "system";
59 break;
60 case TTY_DRIVER_TYPE_CONSOLE:
61 type = "console";
62 break;
63 case TTY_DRIVER_TYPE_SERIAL:
64 if (p->subtype == 2)
65 type = "serial:callout";
66 else
67 type = "serial";
68 break;
69 case TTY_DRIVER_TYPE_PTY:
70 if (p->subtype == PTY_TYPE_MASTER)
71 type = "pty:master";
72 else if (p->subtype == PTY_TYPE_SLAVE)
73 type = "pty:slave";
74 else
75 type = "pty";
76 break;
77 default:
78 sprintf(deftype, "type:%d.%d", p->type, p->subtype);
79 type = deftype;
80 break;
81 }
82 len += sprintf(page+len, "%-20s /dev/%-8s %3d %7s %s\n",
83 p->driver_name ? p->driver_name : "unknown",
84 p->name, p->major, range, type);
85 if (len+begin > off+count)
86 break;
87 if (len+begin < off) {
88 begin += len;
89 len = 0;
90 }
91 }
92 if (!p)
93 *eof = 1;
94 if (off >= len+begin)
95 return 0;
96 *start = page + (off-begin);
97 return ((count < begin+len-off) ? count : begin+len-off);
98 }
99
100 /*
101 * This is the handler for /proc/tty/ldiscs
102 */
103 static int tty_ldiscs_read_proc(char *page, char **start, off_t off,
104 int count, int *eof, void *data)
105 {
106 int i;
107 int len = 0;
108 off_t begin = 0;
109
110 for (i=0; i < NR_LDISCS; i++) {
111 if (!(ldiscs[i].flags & LDISC_FLAG_DEFINED))
112 continue;
113 len += sprintf(page+len, "%-10s %2d\n",
114 ldiscs[i].name ? ldiscs[i].name : "???", i);
115 if (len+begin > off+count)
116 break;
117 if (len+begin < off) {
118 begin += len;
119 len = 0;
120 }
121 }
122 if (i >= NR_LDISCS)
123 *eof = 1;
124 if (off >= len+begin)
125 return 0;
126 *start = page + (off-begin);
127 return ((count < begin+len-off) ? count : begin+len-off);
128 }
129
130 /*
131 * Thsi function is called by register_tty_driver() to handle
132 * registering the driver's /proc handler into /proc/tty/driver/<foo>
133 */
134 void proc_tty_register_driver(struct tty_driver *driver)
135 {
136 struct proc_dir_entry *ent;
137
138 if ((!driver->read_proc && !driver->write_proc) ||
139 !driver->driver_name ||
140 driver->proc_entry)
141 return;
142
143 ent = create_proc_entry(driver->driver_name, 0, proc_tty_driver);
144 if (!ent)
145 return;
146 ent->read_proc = driver->read_proc;
147 ent->write_proc = driver->write_proc;
148 ent->data = driver;
149
150 driver->proc_entry = ent;
151 }
152
153 /*
154 * This function is called by unregister_tty_driver()
155 */
156 void proc_tty_unregister_driver(struct tty_driver *driver)
157 {
158 struct proc_dir_entry *ent;
159
160 ent = driver->proc_entry;
161 if (!ent)
162 return;
163
164 remove_proc_entry(driver->driver_name, proc_tty_driver);
165
166 driver->proc_entry = 0;
167 }
168
169 /*
170 * Called by proc_root_init() to initialize the /proc/tty subtree
171 */
172 void __init proc_tty_init(void)
173 {
174 if (!proc_mkdir("tty", 0))
175 return;
176 proc_tty_ldisc = proc_mkdir("tty/ldisc", 0);
177 proc_tty_driver = proc_mkdir("tty/driver", 0);
178
179 create_proc_read_entry("tty/ldiscs", 0, 0, tty_ldiscs_read_proc,NULL);
180 create_proc_read_entry("tty/drivers", 0, 0, tty_drivers_read_proc,NULL);
181 }
182