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+/*
+ * useful_functions.c, January 2004
+ *
+ * Random collection of functions that can be used by extensions.
+ *
+ * Author: Bart De Schuymer
+ *
+ * This code is stongly inspired on the iptables code which is
+ * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+#include "include/ebtables_u.h"
+#include "include/ethernetdb.h"
+#include <stdio.h>
+#include <netinet/ether.h>
+#include <string.h>
+#include <stdlib.h>
+#include <getopt.h>
+
+const unsigned char mac_type_unicast[ETH_ALEN] = {0,0,0,0,0,0};
+const unsigned char msk_type_unicast[ETH_ALEN] = {1,0,0,0,0,0};
+const unsigned char mac_type_multicast[ETH_ALEN] = {1,0,0,0,0,0};
+const unsigned char msk_type_multicast[ETH_ALEN] = {1,0,0,0,0,0};
+const unsigned char mac_type_broadcast[ETH_ALEN] = {255,255,255,255,255,255};
+const unsigned char msk_type_broadcast[ETH_ALEN] = {255,255,255,255,255,255};
+const unsigned char mac_type_bridge_group[ETH_ALEN] = {0x01,0x80,0xc2,0,0,0};
+const unsigned char msk_type_bridge_group[ETH_ALEN] = {255,255,255,255,255,255};
+
+int ebt_printstyle_mac;
+/*
+ * flag = 2: byte always printed with 2 digits
+ */
+void ebt_print_mac(const char *mac)
+{
+ if (ebt_printstyle_mac == 2) {
+ int j;
+ for (j = 0; j < ETH_ALEN; j++)
+ printf("%02x%s", (unsigned char)mac[j],
+ (j==ETH_ALEN-1) ? "" : ":");
+ } else
+ printf("%s", ether_ntoa((struct ether_addr *) mac));
+}
+
+void ebt_print_mac_and_mask(const char *mac, const char *mask)
+{
+ char hlpmsk[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
+
+ if (!memcmp(mac, mac_type_unicast, 6) &&
+ !memcmp(mask, msk_type_unicast, 6))
+ printf("Unicast");
+ else if (!memcmp(mac, mac_type_multicast, 6) &&
+ !memcmp(mask, msk_type_multicast, 6))
+ printf("Multicast");
+ else if (!memcmp(mac, mac_type_broadcast, 6) &&
+ !memcmp(mask, msk_type_broadcast, 6))
+ printf("Broadcast");
+ else if (!memcmp(mac, mac_type_bridge_group, 6) &&
+ !memcmp(mask, msk_type_bridge_group, 6))
+ printf("BGA");
+ else {
+ ebt_print_mac(mac);
+ if (memcmp(mask, hlpmsk, 6)) {
+ printf("/");
+ ebt_print_mac(mask);
+ }
+ }
+}
+
+/*
+ * Checks the type for validity and calls getethertypebynumber()
+ */
+struct ethertypeent *parseethertypebynumber(int type)
+{
+ if (type < 1536)
+ print_error("Ethernet protocols have values >= 0x0600");
+ if (type > 0xffff)
+ print_error("Ethernet protocols have values <= 0xffff");
+ return getethertypebynumber(type);
+}
+
+/*
+ * put the mac address into 6 (ETH_ALEN) bytes
+ * returns 0 on success
+ */
+int ebt_get_mac_and_mask(char *from, char *to, char *mask)
+{
+ char *p;
+ int i;
+ struct ether_addr *addr;
+
+ if (strcasecmp(from, "Unicast") == 0) {
+ memcpy(to, mac_type_unicast, ETH_ALEN);
+ memcpy(mask, msk_type_unicast, ETH_ALEN);
+ return 0;
+ }
+ if (strcasecmp(from, "Multicast") == 0) {
+ memcpy(to, mac_type_multicast, ETH_ALEN);
+ memcpy(mask, msk_type_multicast, ETH_ALEN);
+ return 0;
+ }
+ if (strcasecmp(from, "Broadcast") == 0) {
+ memcpy(to, mac_type_broadcast, ETH_ALEN);
+ memcpy(mask, msk_type_broadcast, ETH_ALEN);
+ return 0;
+ }
+ if (strcasecmp(from, "BGA") == 0) {
+ memcpy(to, mac_type_bridge_group, ETH_ALEN);
+ memcpy(mask, msk_type_bridge_group, ETH_ALEN);
+ return 0;
+ }
+ if ( (p = strrchr(from, '/')) != NULL) {
+ *p = '\0';
+ if (!(addr = ether_aton(p + 1)))
+ return -1;
+ memcpy(mask, addr, ETH_ALEN);
+ } else
+ memset(mask, 0xff, ETH_ALEN);
+ if (!(addr = ether_aton(from)))
+ return -1;
+ memcpy(to, addr, ETH_ALEN);
+ for (i = 0; i < ETH_ALEN; i++)
+ to[i] &= mask[i];
+ return 0;
+}
+
+int ebt_invert = 0;
+int ebt_check_inverse(const char option[])
+{
+ if (strcmp(option, "!") == 0) {
+ if (ebt_invert == 1)
+ print_error("double use of '!' not allowed");
+ optind++;
+ ebt_invert = 1;
+ return 1;
+ }
+ return ebt_invert;
+}
+
+void ebt_check_option(unsigned int *flags, unsigned int mask)
+{
+ if (*flags & mask)
+ print_error("Multiple use of same option not allowed");
+ *flags |= mask;
+}
+
+/* put the ip string into 4 bytes */
+static int undot_ip(char *ip, unsigned char *ip2)
+{
+ char *p, *q, *end;
+ long int onebyte;
+ int i;
+ char buf[20];
+
+ strncpy(buf, ip, sizeof(buf) - 1);
+
+ p = buf;
+ for (i = 0; i < 3; i++) {
+ if ((q = strchr(p, '.')) == NULL)
+ return -1;
+ *q = '\0';
+ onebyte = strtol(p, &end, 10);
+ if (*end != '\0' || onebyte > 255 || onebyte < 0)
+ return -1;
+ ip2[i] = (unsigned char)onebyte;
+ p = q + 1;
+ }
+
+ onebyte = strtol(p, &end, 10);
+ if (*end != '\0' || onebyte > 255 || onebyte < 0)
+ return -1;
+ ip2[3] = (unsigned char)onebyte;
+
+ return 0;
+}
+
+/* put the mask into 4 bytes */
+static int ip_mask(char *mask, unsigned char *mask2)
+{
+ char *end;
+ long int bits;
+ uint32_t mask22;
+
+ if (undot_ip(mask, mask2)) {
+ /* not the /a.b.c.e format, maybe the /x format */
+ bits = strtol(mask, &end, 10);
+ if (*end != '\0' || bits > 32 || bits < 0)
+ return -1;
+ if (bits != 0) {
+ mask22 = htonl(0xFFFFFFFF << (32 - bits));
+ memcpy(mask2, &mask22, 4);
+ } else {
+ mask22 = 0xFFFFFFFF;
+ memcpy(mask2, &mask22, 4);
+ }
+ }
+ return 0;
+}
+
+/* set the ip mask and ip address */
+void ebt_parse_ip_address(char *address, uint32_t *addr, uint32_t *msk)
+{
+ char *p;
+
+ /* first the mask */
+ if ((p = strrchr(address, '/')) != NULL) {
+ *p = '\0';
+ if (ip_mask(p + 1, (unsigned char *)msk))
+ print_error("Problem with the IP mask");
+ } else
+ *msk = 0xFFFFFFFF;
+
+ if (undot_ip(address, (unsigned char *)addr))
+ print_error("Problem with the IP address");
+ *addr = *addr & *msk;
+}
+
+/* transform the ip mask into a string ready for output */
+char *ebt_mask_to_dotted(uint32_t mask)
+{
+ int i;
+ static char buf[20];
+ uint32_t maskaddr, bits;
+
+ maskaddr = ntohl(mask);
+
+ /* don't print /32 */
+ if (mask == 0xFFFFFFFFL) {
+ *buf = '\0';
+ return buf;
+ }
+
+ i = 32;
+ bits = 0xFFFFFFFEL; /* case 0xFFFFFFFF has just been dealt with */
+ while (--i >= 0 && maskaddr != bits)
+ bits <<= 1;
+
+ if (i > 0)
+ sprintf(buf, "/%d", i);
+ else if (!i)
+ *buf = '\0';
+ else
+ /* mask was not a decent combination of 1's and 0's */
+ sprintf(buf, "/%d.%d.%d.%d", ((unsigned char *)&mask)[0],
+ ((unsigned char *)&mask)[1], ((unsigned char *)&mask)[2],
+ ((unsigned char *)&mask)[3]);
+
+ return buf;
+}