1/*
 2 *  drivers/s390/char/ctrlchar.c
 3 *  Unified handling of special chars.
 4 *
 5 *    Copyright (C) 2001 IBM Deutschland Entwicklung GmbH, IBM Corporation
 6 *    Author(s): Fritz Elfert <felfert@millenux.com> <elfert@de.ibm.com>
 7 *
 8 */
 9
10#include <linux/stddef.h>
11#include <asm/errno.h>
12#include <linux/sysrq.h>
13#include <linux/ctype.h>
14
15#include "ctrlchar.h"
16
17#ifdef CONFIG_MAGIC_SYSRQ
18static int ctrlchar_sysrq_key;
19
20static void
21ctrlchar_handle_sysrq(struct work_struct *work)
22{
23	handle_sysrq(ctrlchar_sysrq_key);
 
 
24}
25
26static DECLARE_WORK(ctrlchar_work, ctrlchar_handle_sysrq);
 
 
 
 
27#endif
28
29
30/**
31 * Check for special chars at start of input.
32 *
33 * @param buf Console input buffer.
34 * @param len Length of valid data in buffer.
35 * @param tty The tty struct for this console.
36 * @return CTRLCHAR_NONE, if nothing matched,
37 *         CTRLCHAR_SYSRQ, if sysrq was encountered
38 *         otherwise char to be inserted logically or'ed
39 *         with CTRLCHAR_CTRL
40 */
41unsigned int
42ctrlchar_handle(const unsigned char *buf, int len, struct tty_struct *tty)
43{
44	if ((len < 2) || (len > 3))
45		return CTRLCHAR_NONE;
46
47	/* hat is 0xb1 in codepage 037 (US etc.) and thus */
48	/* converted to 0x5e in ascii ('^') */
49	if ((buf[0] != '^') && (buf[0] != '\252'))
50		return CTRLCHAR_NONE;
51
52#ifdef CONFIG_MAGIC_SYSRQ
53	/* racy */
54	if (len == 3 && buf[1] == '-') {
55		ctrlchar_sysrq_key = buf[2];
56		schedule_work(&ctrlchar_work);
57		return CTRLCHAR_SYSRQ;
58	}
59#endif
60
61	if (len != 2)
62		return CTRLCHAR_NONE;
63
64	switch (tolower(buf[1])) {
65	case 'c':
66		return INTR_CHAR(tty) | CTRLCHAR_CTRL;
67	case 'd':
68		return EOF_CHAR(tty)  | CTRLCHAR_CTRL;
69	case 'z':
70		return SUSP_CHAR(tty) | CTRLCHAR_CTRL;
71	}
72	return CTRLCHAR_NONE;
73}

 1/*
 
 2 *  Unified handling of special chars.
 3 *
 4 *    Copyright IBM Corp. 2001
 5 *    Author(s): Fritz Elfert <felfert@millenux.com> <elfert@de.ibm.com>
 6 *
 7 */
 8
 9#include <linux/stddef.h>
10#include <asm/errno.h>
11#include <linux/sysrq.h>
12#include <linux/ctype.h>
13
14#include "ctrlchar.h"
15
16#ifdef CONFIG_MAGIC_SYSRQ
17static struct sysrq_work ctrlchar_sysrq;
18
19static void
20ctrlchar_handle_sysrq(struct work_struct *work)
21{
22	struct sysrq_work *sysrq = container_of(work, struct sysrq_work, work);
23
24	handle_sysrq(sysrq->key);
25}
26
27void schedule_sysrq_work(struct sysrq_work *sw)
28{
29	INIT_WORK(&sw->work, ctrlchar_handle_sysrq);
30	schedule_work(&sw->work);
31}
32#endif
33
34
35/**
36 * Check for special chars at start of input.
37 *
38 * @param buf Console input buffer.
39 * @param len Length of valid data in buffer.
40 * @param tty The tty struct for this console.
41 * @return CTRLCHAR_NONE, if nothing matched,
42 *         CTRLCHAR_SYSRQ, if sysrq was encountered
43 *         otherwise char to be inserted logically or'ed
44 *         with CTRLCHAR_CTRL
45 */
46unsigned int
47ctrlchar_handle(const unsigned char *buf, int len, struct tty_struct *tty)
48{
49	if ((len < 2) || (len > 3))
50		return CTRLCHAR_NONE;
51
52	/* hat is 0xb1 in codepage 037 (US etc.) and thus */
53	/* converted to 0x5e in ascii ('^') */
54	if ((buf[0] != '^') && (buf[0] != '\252'))
55		return CTRLCHAR_NONE;
56
57#ifdef CONFIG_MAGIC_SYSRQ
58	/* racy */
59	if (len == 3 && buf[1] == '-') {
60		ctrlchar_sysrq.key = buf[2];
61		schedule_sysrq_work(&ctrlchar_sysrq);
62		return CTRLCHAR_SYSRQ;
63	}
64#endif
65
66	if (len != 2)
67		return CTRLCHAR_NONE;
68
69	switch (tolower(buf[1])) {
70	case 'c':
71		return INTR_CHAR(tty) | CTRLCHAR_CTRL;
72	case 'd':
73		return EOF_CHAR(tty)  | CTRLCHAR_CTRL;
74	case 'z':
75		return SUSP_CHAR(tty) | CTRLCHAR_CTRL;
76	}
77	return CTRLCHAR_NONE;
78}