diff options
Diffstat (limited to 'package/network/utils/maccalc/src/main.c')
| -rw-r--r-- | package/network/utils/maccalc/src/main.c | 256 |
1 files changed, 256 insertions, 0 deletions
diff --git a/package/network/utils/maccalc/src/main.c b/package/network/utils/maccalc/src/main.c new file mode 100644 index 0000000..dcb5f55 --- /dev/null +++ b/package/network/utils/maccalc/src/main.c @@ -0,0 +1,256 @@ +/* + * MAC address manupulation utility + * + * Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published + * by the Free Software Foundation. + * + */ + +#include <errno.h> +#include <stdlib.h> +#include <stdio.h> +#include <stdint.h> +#include <string.h> +#include <unistd.h> + +#define MAC_ADDRESS_LEN 6 + +#define ERR_INVALID 1 +#define ERR_IO 2 + +static void usage(void); + +char *maccalc_name; + +static int parse_mac(const char *mac_str, unsigned char *buf) +{ + int t; + + t = sscanf(mac_str, "%02hhx:%02hhx:%02hhx:%02hhx:%02hhx:%02hhx", + &buf[0], &buf[1], &buf[2], &buf[3], &buf[4], &buf[5]); + + if (t != MAC_ADDRESS_LEN) + return ERR_INVALID; + + return 0; +} + +static void print_mac(unsigned char *buf) +{ + printf("%02x:%02x:%02x:%02x:%02x:%02x\n", + buf[0], buf[1], buf[2], buf[3], buf[4], buf[5]); +} + +static int maccalc_do_add(int argc, const char *argv[]) +{ + unsigned char mac[MAC_ADDRESS_LEN]; + uint32_t t; + int err; + int i; + + if (argc != 2) { + usage(); + return ERR_INVALID; + } + + err = parse_mac(argv[0], mac); + if (err) + return err; + + i = atoi(argv[1]); + + t = (mac[3] << 16) | (mac[4] << 8) | mac[5]; + t += i; + mac[3] = (t >> 16) & 0xff; + mac[4] = (t >> 8) & 0xff; + mac[5] = t & 0xff; + + print_mac(mac); + return 0; +} + +static int maccalc_do_logical(int argc, const char *argv[], + unsigned char (*op)(unsigned char n1, + unsigned char n2)) +{ + unsigned char mac1[MAC_ADDRESS_LEN]; + unsigned char mac2[MAC_ADDRESS_LEN]; + int err; + int i; + + if (argc != 2) { + usage(); + return ERR_INVALID; + } + + err = parse_mac(argv[0], mac1); + if (err) + return err; + + err = parse_mac(argv[1], mac2); + if (err) + return err; + + for (i = 0; i < MAC_ADDRESS_LEN; i++) + mac1[i] = op(mac1[i],mac2[i]); + + print_mac(mac1); + return 0; +} + +static int maccalc_do_mac2bin(int argc, const char *argv[]) +{ + unsigned char mac[MAC_ADDRESS_LEN]; + ssize_t c; + int err; + + if (argc != 1) { + usage(); + return ERR_INVALID; + } + + err = parse_mac(argv[0], mac); + if (err) + return err; + + c = write(STDOUT_FILENO, mac, sizeof(mac)); + if (c != sizeof(mac)) { + fprintf(stderr, "failed to write to stdout\n"); + return ERR_IO; + } + + return 0; +} + +static ssize_t read_safe(int fd, void *buf, size_t count) +{ + ssize_t total = 0; + ssize_t r; + + while(count > 0) { + r = read(fd, buf, count); + if (r == 0) + /* EOF */ + break; + if (r < 0) { + if (errno == EINTR) + /* interrupted by a signal, restart */ + continue; + /* error */ + total = -1; + break; + } + + /* ok */ + total += r; + count -= r; + buf += r; + } + + return total; +} + +static int maccalc_do_bin2mac(int argc, const char *argv[]) +{ + unsigned char mac[MAC_ADDRESS_LEN]; + ssize_t c; + + if (argc != 0) { + usage(); + return ERR_INVALID; + } + + c = read_safe(STDIN_FILENO, mac, sizeof(mac)); + if (c != sizeof(mac)) { + fprintf(stderr, "failed to read from stdin\n"); + return ERR_IO; + } + + print_mac(mac); + return 0; +} + +static unsigned char op_or(unsigned char n1, unsigned char n2) +{ + return n1 | n2; +} + +static int maccalc_do_or(int argc, const char *argv[]) +{ + return maccalc_do_logical(argc, argv, op_or); +} + +static unsigned char op_and(unsigned char n1, unsigned char n2) +{ + return n1 & n2; +} + +static int maccalc_do_and(int argc, const char *argv[]) +{ + return maccalc_do_logical(argc, argv, op_and); +} + +static unsigned char op_xor(unsigned char n1, unsigned char n2) +{ + return n1 ^ n2; +} + +static int maccalc_do_xor(int argc, const char *argv[]) +{ + return maccalc_do_logical(argc, argv, op_xor); +} + +static void usage(void) +{ + fprintf(stderr, + "Usage: %s <command>\n" + "valid commands:\n" + " add <mac> <number>\n" + " and|or|xor <mac1> <mac2>\n" + " mac2bin <mac>\n" + " bin2mac\n", + maccalc_name); +} + +int main(int argc, const char *argv[]) +{ + int (*op)(int argc, const char *argv[]); + int ret; + + maccalc_name = (char *) argv[0]; + + if (argc < 2) { + usage(); + return EXIT_FAILURE; + } + + if (strcmp(argv[1], "add") == 0) { + op = maccalc_do_add; + } else if (strcmp(argv[1], "and") == 0) { + op = maccalc_do_and; + } else if (strcmp(argv[1], "or") == 0) { + op = maccalc_do_or; + } else if (strcmp(argv[1], "xor") == 0) { + op = maccalc_do_xor; + } else if (strcmp(argv[1], "mac2bin") == 0) { + op = maccalc_do_mac2bin; + } else if (strcmp(argv[1], "bin2mac") == 0) { + op = maccalc_do_bin2mac; + } else { + fprintf(stderr, "unknown command '%s'\n", argv[1]); + usage(); + return EXIT_FAILURE; + } + + argc -= 2; + argv += 2; + + ret = op(argc, argv); + if (ret) + return EXIT_FAILURE; + + return EXIT_SUCCESS; +} |