package/maccalc: a simple mac address manipulation utility

SVN-Revision: 28004

1 files changed, 227 insertions, 0 deletions

diff --git a/package/maccalc/src/main.c b/package/maccalc/src/main.c
new file mode 100644
index 0000000..e1e12cd
--- /dev/null
+++ b/package/maccalc/src/main.c
@@ -0,0 +1,227 @@
+/*
+ * 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 <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 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(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;
+}