[3320] | 1 | /* vi: set sw=4 ts=4: */
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| 2 | /*
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| 3 | * Utility routines.
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| 4 | *
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| 5 | * Copyright (C) many different people. If you wrote this, please
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| 6 | * acknowledge your work.
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| 7 | *
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| 8 | * Licensed under GPLv2 or later, see file LICENSE in this source tree.
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| 9 | */
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| 10 |
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| 11 | #include "libbb.h"
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| 12 |
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| 13 | /* From <linux/kd.h> */
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| 14 | enum { KDGKBTYPE = 0x4B33 }; /* get keyboard type */
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| 15 |
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| 16 | static int open_a_console(const char *fnam)
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| 17 | {
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| 18 | int fd;
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| 19 |
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| 20 | /* try read-write */
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| 21 | fd = open(fnam, O_RDWR);
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| 22 |
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| 23 | /* if failed, try read-only */
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| 24 | if (fd < 0 && errno == EACCES)
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| 25 | fd = open(fnam, O_RDONLY);
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| 26 |
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| 27 | /* if failed, try write-only */
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| 28 | if (fd < 0 && errno == EACCES)
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| 29 | fd = open(fnam, O_WRONLY);
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| 30 |
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| 31 | return fd;
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| 32 | }
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| 33 |
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| 34 | /*
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| 35 | * Get an fd for use with kbd/console ioctls.
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| 36 | * We try several things because opening /dev/console will fail
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| 37 | * if someone else used X (which does a chown on /dev/console).
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| 38 | */
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| 39 | int FAST_FUNC get_console_fd_or_die(void)
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| 40 | {
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| 41 | static const char *const console_names[] = {
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| 42 | DEV_CONSOLE, CURRENT_VC, CURRENT_TTY
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| 43 | };
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| 44 |
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| 45 | int fd;
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| 46 |
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| 47 | for (fd = 2; fd >= 0; fd--) {
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| 48 | int fd4name;
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| 49 | int choice_fd;
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| 50 | char arg;
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| 51 |
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| 52 | fd4name = open_a_console(console_names[fd]);
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| 53 | chk_std:
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| 54 | choice_fd = (fd4name >= 0 ? fd4name : fd);
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| 55 |
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| 56 | arg = 0;
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| 57 | if (ioctl(choice_fd, KDGKBTYPE, &arg) == 0)
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| 58 | return choice_fd;
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| 59 | if (fd4name >= 0) {
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| 60 | close(fd4name);
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| 61 | fd4name = -1;
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| 62 | goto chk_std;
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| 63 | }
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| 64 | }
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| 65 |
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| 66 | bb_error_msg_and_die("can't open console");
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| 67 | /*return fd; - total failure */
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| 68 | }
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| 69 |
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| 70 | /* From <linux/vt.h> */
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| 71 | enum {
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| 72 | VT_ACTIVATE = 0x5606, /* make vt active */
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| 73 | VT_WAITACTIVE = 0x5607 /* wait for vt active */
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| 74 | };
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| 75 |
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| 76 | void FAST_FUNC console_make_active(int fd, const int vt_num)
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| 77 | {
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| 78 | xioctl(fd, VT_ACTIVATE, (void *)(ptrdiff_t)vt_num);
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| 79 | xioctl(fd, VT_WAITACTIVE, (void *)(ptrdiff_t)vt_num);
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| 80 | }
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