blob: 4041817200024ed0b540e052dc38356fe6e30bba [file] [log] [blame]
Denis Vlasenko2afabe82007-12-10 07:06:04 +00001/* vi: set sw=4 ts=4: */
2/*
Denis Vlasenko6d709972007-05-18 09:45:36 +00003 * Licensed under GPLv2
Denis Vlasenko2afabe82007-12-10 07:06:04 +00004 *
5 * Copyright (c) 2007 Denys Vlasenko <vda.linux@googlemail.com>
Denis Vlasenko6d709972007-05-18 09:45:36 +00006 */
7#include "libbb.h"
8
9/* From <linux/vt.h> */
10struct vt_stat {
Denis Vlasenko2afabe82007-12-10 07:06:04 +000011 unsigned short v_active; /* active vt */
12 unsigned short v_signal; /* signal to send */
13 unsigned short v_state; /* vt bitmask */
Denis Vlasenko6d709972007-05-18 09:45:36 +000014};
Denis Vlasenko2afabe82007-12-10 07:06:04 +000015enum { VT_GETSTATE = 0x5603 }; /* get global vt state info */
Denis Vlasenko6d709972007-05-18 09:45:36 +000016
17/* From <linux/serial.h> */
18struct serial_struct {
19 int type;
20 int line;
21 unsigned int port;
22 int irq;
23 int flags;
24 int xmit_fifo_size;
25 int custom_divisor;
26 int baud_base;
27 unsigned short close_delay;
28 char io_type;
29 char reserved_char[1];
30 int hub6;
Denis Vlasenko2afabe82007-12-10 07:06:04 +000031 unsigned short closing_wait; /* time to wait before closing */
32 unsigned short closing_wait2; /* no longer used... */
Denis Vlasenko6d709972007-05-18 09:45:36 +000033 unsigned char *iomem_base;
34 unsigned short iomem_reg_shift;
35 unsigned int port_high;
36 unsigned long iomap_base; /* cookie passed into ioremap */
37 int reserved[1];
38};
39
Denis Vlasenko528a8b92007-12-22 19:57:28 +000040int cttyhack_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
Denis Vlasenko6d709972007-05-18 09:45:36 +000041int cttyhack_main(int argc, char **argv)
42{
43 int fd;
44 char console[sizeof(int)*3 + 16];
45 union {
46 struct vt_stat vt;
47 struct serial_struct sr;
48 char paranoia[sizeof(struct serial_struct) * 3];
49 } u;
50
51 if (!*++argv) {
52 bb_show_usage();
53 }
54
55 strcpy(console, "/dev/tty");
56 if (ioctl(0, TIOCGSERIAL, &u.sr) == 0) {
57 /* this is a serial console */
58 sprintf(console + 8, "S%d", u.sr.line);
59 } else if (ioctl(0, VT_GETSTATE, &u.vt) == 0) {
60 /* this is linux virtual tty */
61 sprintf(console + 8, "S%d" + 1, u.vt.v_active);
62 }
63
64 if (console[8]) {
65 fd = xopen(console, O_RDWR);
66 //bb_error_msg("switching to '%s'", console);
67 dup2(fd, 0);
68 dup2(fd, 1);
69 dup2(fd, 2);
70 while (fd > 2) close(fd--);
Denis Vlasenko2afabe82007-12-10 07:06:04 +000071 /* Some other session may have it as ctty. Steal it from them */
Denis Vlasenkod7e2e122007-12-10 08:40:29 +000072 ioctl(0, TIOCSCTTY, 1);
Denis Vlasenko6d709972007-05-18 09:45:36 +000073 }
74
Denis Vlasenko2afabe82007-12-10 07:06:04 +000075 BB_EXECVP(argv[0], argv);
Denis Vlasenko6d709972007-05-18 09:45:36 +000076 bb_perror_msg_and_die("cannot exec '%s'", argv[0]);
77}