Denis 'GNUtoo' Carikli | bfe0789 | 2016-02-21 14:27:21 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2016 Denis 'GNUtoo' Carikli <GNUtoo@no-log.org> |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License as published by |
| 6 | * the Free Software Foundation; either version 2 of the License, or |
| 7 | * (at your option) any later version. |
| 8 | * |
| 9 | * This program is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | * GNU General Public License for more details. |
| 13 | */ |
| 14 | |
| 15 | #include <errno.h> |
| 16 | #include <limits.h> |
| 17 | #include <stdarg.h> |
| 18 | #include <stdio.h> |
| 19 | #include <stdlib.h> |
| 20 | #include <sys/io.h> |
| 21 | |
| 22 | #define POST_DEFAULT_IO_PORT 0x80 |
| 23 | |
| 24 | void usage(char *progname, const char *error, ...) |
| 25 | { |
| 26 | printf("Usage: %s <VALUE> [PORT]\n", progname); |
| 27 | printf("The VALUE argument is an integer between 0x00 and 0xff\n"); |
| 28 | printf("The PORT argument is an integer between 0x00 and 0xffff\n"); |
| 29 | |
| 30 | if (error) { |
| 31 | va_list args; |
| 32 | |
| 33 | va_start(args, error); |
| 34 | vprintf(error, args); |
| 35 | va_end(args); |
| 36 | }; |
| 37 | } |
| 38 | |
| 39 | void check_int(long val, int min, int max, int err, char *string, char *endptr, |
| 40 | char *progname) |
| 41 | { |
| 42 | if (val < min || val > max) { |
| 43 | usage(progname, |
| 44 | "\nError: The value has to be between 0x%x and 0x%x\n", |
| 45 | min, max); |
| 46 | exit(EXIT_FAILURE); |
| 47 | } |
| 48 | |
| 49 | if (endptr == string || *endptr != '\0') { |
| 50 | usage(progname, "\nError: An integer is required\n"); |
| 51 | exit(EXIT_FAILURE); |
| 52 | } |
| 53 | |
| 54 | if ((err) && (!val)) { |
| 55 | perror("strtol"); |
| 56 | exit(EXIT_FAILURE); |
| 57 | } |
| 58 | } |
| 59 | |
| 60 | int main(int argc, char *argv[]) |
| 61 | { |
| 62 | unsigned long val; |
| 63 | unsigned long port = POST_DEFAULT_IO_PORT; |
| 64 | char *endptr; |
| 65 | int err; |
| 66 | |
| 67 | if (argc != 2 && argc != 3) { |
| 68 | usage(argv[0], NULL); |
| 69 | exit(EXIT_FAILURE); |
| 70 | } |
| 71 | |
| 72 | val = strtol(argv[1], &endptr, 0); |
| 73 | err = errno; |
| 74 | check_int(val, 0x00, 0xff, err, argv[1], endptr, argv[0]); |
| 75 | |
| 76 | if (argc > 2) { |
| 77 | port = strtol(argv[2], &endptr, 0); |
| 78 | err = errno; |
| 79 | check_int(port, 0x0000, 0xffff, err, argv[2], endptr, argv[0]); |
| 80 | } |
| 81 | |
| 82 | err = iopl(3); |
| 83 | if (err == -1) { |
| 84 | perror("Not root"); |
| 85 | exit(EXIT_FAILURE); |
| 86 | } |
| 87 | |
| 88 | outb(val, port); |
| 89 | |
| 90 | return 0; |
| 91 | } |