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364 lines
9.1 KiB
364 lines
9.1 KiB
/* ebt_arp
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*
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* Authors:
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* Bart De Schuymer <bdschuym@pandora.be>
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* Tim Gardner <timg@tpi.com>
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*
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* April, 2002
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*/
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#include <stdio.h>
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#include <string.h>
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#include <stdlib.h>
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#include <getopt.h>
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#include <xtables.h>
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#include <netinet/ether.h>
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#include <xtables.h>
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#include <net/if_arp.h>
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#include <linux/netfilter_bridge/ebt_arp.h>
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#include "iptables/nft.h"
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#include "iptables/nft-bridge.h"
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#define ARP_OPCODE '1'
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#define ARP_HTYPE '2'
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#define ARP_PTYPE '3'
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#define ARP_IP_S '4'
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#define ARP_IP_D '5'
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#define ARP_MAC_S '6'
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#define ARP_MAC_D '7'
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#define ARP_GRAT '8'
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static const struct option brarp_opts[] = {
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{ "arp-opcode" , required_argument, 0, ARP_OPCODE },
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{ "arp-op" , required_argument, 0, ARP_OPCODE },
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{ "arp-htype" , required_argument, 0, ARP_HTYPE },
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{ "arp-ptype" , required_argument, 0, ARP_PTYPE },
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{ "arp-ip-src" , required_argument, 0, ARP_IP_S },
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{ "arp-ip-dst" , required_argument, 0, ARP_IP_D },
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{ "arp-mac-src" , required_argument, 0, ARP_MAC_S },
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{ "arp-mac-dst" , required_argument, 0, ARP_MAC_D },
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{ "arp-gratuitous", no_argument, 0, ARP_GRAT },
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XT_GETOPT_TABLEEND,
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};
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/* a few names */
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static char *opcodes[] =
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{
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"Request",
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"Reply",
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"Request_Reverse",
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"Reply_Reverse",
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"DRARP_Request",
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"DRARP_Reply",
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"DRARP_Error",
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"InARP_Request",
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"ARP_NAK",
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};
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static void brarp_print_help(void)
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{
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int i;
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printf(
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"arp options:\n"
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"--arp-opcode [!] opcode : ARP opcode (integer or string)\n"
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"--arp-htype [!] type : ARP hardware type (integer or string)\n"
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"--arp-ptype [!] type : ARP protocol type (hexadecimal or string)\n"
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"--arp-ip-src [!] address[/mask]: ARP IP source specification\n"
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"--arp-ip-dst [!] address[/mask]: ARP IP target specification\n"
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"--arp-mac-src [!] address[/mask]: ARP MAC source specification\n"
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"--arp-mac-dst [!] address[/mask]: ARP MAC target specification\n"
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"[!] --arp-gratuitous : ARP gratuitous packet\n"
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" opcode strings: \n");
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for (i = 0; i < ARRAY_SIZE(opcodes); i++)
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printf(" %d = %s\n", i + 1, opcodes[i]);
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printf(
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" hardware type string: 1 = Ethernet\n"
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" protocol type string: see "XT_PATH_ETHERTYPES"\n");
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}
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#define OPT_OPCODE 0x01
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#define OPT_HTYPE 0x02
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#define OPT_PTYPE 0x04
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#define OPT_IP_S 0x08
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#define OPT_IP_D 0x10
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#define OPT_MAC_S 0x20
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#define OPT_MAC_D 0x40
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#define OPT_GRAT 0x80
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static int undot_ip(char *ip, unsigned char *ip2)
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{
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char *p, *q, *end;
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long int onebyte;
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int i;
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char buf[20];
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strncpy(buf, ip, sizeof(buf) - 1);
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p = buf;
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for (i = 0; i < 3; i++) {
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if ((q = strchr(p, '.')) == NULL)
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return -1;
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*q = '\0';
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onebyte = strtol(p, &end, 10);
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if (*end != '\0' || onebyte > 255 || onebyte < 0)
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return -1;
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ip2[i] = (unsigned char)onebyte;
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p = q + 1;
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}
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onebyte = strtol(p, &end, 10);
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if (*end != '\0' || onebyte > 255 || onebyte < 0)
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return -1;
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ip2[3] = (unsigned char)onebyte;
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return 0;
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}
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static int ip_mask(char *mask, unsigned char *mask2)
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{
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char *end;
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long int bits;
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uint32_t mask22;
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if (undot_ip(mask, mask2)) {
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/* not the /a.b.c.e format, maybe the /x format */
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bits = strtol(mask, &end, 10);
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if (*end != '\0' || bits > 32 || bits < 0)
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return -1;
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if (bits != 0) {
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mask22 = htonl(0xFFFFFFFF << (32 - bits));
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memcpy(mask2, &mask22, 4);
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} else {
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mask22 = 0xFFFFFFFF;
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memcpy(mask2, &mask22, 4);
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}
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}
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return 0;
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}
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static void ebt_parse_ip_address(char *address, uint32_t *addr, uint32_t *msk)
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{
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char *p;
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/* first the mask */
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if ((p = strrchr(address, '/')) != NULL) {
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*p = '\0';
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if (ip_mask(p + 1, (unsigned char *)msk)) {
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xtables_error(PARAMETER_PROBLEM,
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"Problem with the IP mask '%s'", p + 1);
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return;
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}
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} else
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*msk = 0xFFFFFFFF;
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if (undot_ip(address, (unsigned char *)addr)) {
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xtables_error(PARAMETER_PROBLEM,
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"Problem with the IP address '%s'", address);
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return;
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}
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*addr = *addr & *msk;
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}
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static int
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brarp_parse(int c, char **argv, int invert, unsigned int *flags,
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const void *entry, struct xt_entry_match **match)
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{
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struct ebt_arp_info *arpinfo = (struct ebt_arp_info *)(*match)->data;
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long int i;
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char *end;
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uint32_t *addr;
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uint32_t *mask;
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unsigned char *maddr;
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unsigned char *mmask;
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switch (c) {
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case ARP_OPCODE:
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EBT_CHECK_OPTION(flags, OPT_OPCODE);
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if (invert)
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arpinfo->invflags |= EBT_ARP_OPCODE;
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i = strtol(optarg, &end, 10);
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if (i < 0 || i >= (0x1 << 16) || *end !='\0') {
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for (i = 0; i < ARRAY_SIZE(opcodes); i++)
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if (!strcasecmp(opcodes[i], optarg))
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break;
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if (i == ARRAY_SIZE(opcodes))
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xtables_error(PARAMETER_PROBLEM, "Problem with specified ARP opcode");
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i++;
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}
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arpinfo->opcode = htons(i);
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arpinfo->bitmask |= EBT_ARP_OPCODE;
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break;
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case ARP_HTYPE:
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EBT_CHECK_OPTION(flags, OPT_HTYPE);
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if (invert)
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arpinfo->invflags |= EBT_ARP_HTYPE;
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i = strtol(optarg, &end, 10);
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if (i < 0 || i >= (0x1 << 16) || *end !='\0') {
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if (!strcasecmp("Ethernet", argv[optind - 1]))
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i = 1;
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else
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xtables_error(PARAMETER_PROBLEM, "Problem with specified ARP hardware type");
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}
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arpinfo->htype = htons(i);
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arpinfo->bitmask |= EBT_ARP_HTYPE;
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break;
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case ARP_PTYPE: {
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uint16_t proto;
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EBT_CHECK_OPTION(flags, OPT_PTYPE);
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if (invert)
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arpinfo->invflags |= EBT_ARP_PTYPE;
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i = strtol(optarg, &end, 16);
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if (i < 0 || i >= (0x1 << 16) || *end !='\0') {
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struct xt_ethertypeent *ent;
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ent = xtables_getethertypebyname(argv[optind - 1]);
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if (!ent)
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xtables_error(PARAMETER_PROBLEM, "Problem with specified ARP "
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"protocol type");
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proto = ent->e_ethertype;
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} else
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proto = i;
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arpinfo->ptype = htons(proto);
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arpinfo->bitmask |= EBT_ARP_PTYPE;
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break;
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}
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case ARP_IP_S:
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case ARP_IP_D:
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if (c == ARP_IP_S) {
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EBT_CHECK_OPTION(flags, OPT_IP_S);
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addr = &arpinfo->saddr;
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mask = &arpinfo->smsk;
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arpinfo->bitmask |= EBT_ARP_SRC_IP;
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} else {
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EBT_CHECK_OPTION(flags, OPT_IP_D);
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addr = &arpinfo->daddr;
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mask = &arpinfo->dmsk;
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arpinfo->bitmask |= EBT_ARP_DST_IP;
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}
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if (invert) {
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if (c == ARP_IP_S)
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arpinfo->invflags |= EBT_ARP_SRC_IP;
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else
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arpinfo->invflags |= EBT_ARP_DST_IP;
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}
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ebt_parse_ip_address(optarg, addr, mask);
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break;
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case ARP_MAC_S:
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case ARP_MAC_D:
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if (c == ARP_MAC_S) {
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EBT_CHECK_OPTION(flags, OPT_MAC_S);
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maddr = arpinfo->smaddr;
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mmask = arpinfo->smmsk;
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arpinfo->bitmask |= EBT_ARP_SRC_MAC;
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} else {
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EBT_CHECK_OPTION(flags, OPT_MAC_D);
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maddr = arpinfo->dmaddr;
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mmask = arpinfo->dmmsk;
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arpinfo->bitmask |= EBT_ARP_DST_MAC;
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}
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if (invert) {
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if (c == ARP_MAC_S)
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arpinfo->invflags |= EBT_ARP_SRC_MAC;
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else
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arpinfo->invflags |= EBT_ARP_DST_MAC;
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}
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if (xtables_parse_mac_and_mask(optarg, maddr, mmask))
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xtables_error(PARAMETER_PROBLEM, "Problem with ARP MAC address argument");
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break;
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case ARP_GRAT:
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EBT_CHECK_OPTION(flags, OPT_GRAT);
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arpinfo->bitmask |= EBT_ARP_GRAT;
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if (invert)
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arpinfo->invflags |= EBT_ARP_GRAT;
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break;
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default:
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return 0;
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}
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return 1;
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}
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static void brarp_print(const void *ip, const struct xt_entry_match *match, int numeric)
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{
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const struct ebt_arp_info *arpinfo = (struct ebt_arp_info *)match->data;
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if (arpinfo->bitmask & EBT_ARP_OPCODE) {
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int opcode = ntohs(arpinfo->opcode);
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printf("--arp-op ");
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if (arpinfo->invflags & EBT_ARP_OPCODE)
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printf("! ");
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if (opcode > 0 && opcode <= ARRAY_SIZE(opcodes))
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printf("%s ", opcodes[opcode - 1]);
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else
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printf("%d ", opcode);
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}
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if (arpinfo->bitmask & EBT_ARP_HTYPE) {
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printf("--arp-htype ");
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if (arpinfo->invflags & EBT_ARP_HTYPE)
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printf("! ");
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printf("%d ", ntohs(arpinfo->htype));
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}
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if (arpinfo->bitmask & EBT_ARP_PTYPE) {
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printf("--arp-ptype ");
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if (arpinfo->invflags & EBT_ARP_PTYPE)
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printf("! ");
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printf("0x%x ", ntohs(arpinfo->ptype));
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}
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if (arpinfo->bitmask & EBT_ARP_SRC_IP) {
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printf("--arp-ip-src ");
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if (arpinfo->invflags & EBT_ARP_SRC_IP)
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printf("! ");
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printf("%s%s ", xtables_ipaddr_to_numeric((const struct in_addr*) &arpinfo->saddr),
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xtables_ipmask_to_numeric((const struct in_addr*)&arpinfo->smsk));
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}
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if (arpinfo->bitmask & EBT_ARP_DST_IP) {
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printf("--arp-ip-dst ");
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if (arpinfo->invflags & EBT_ARP_DST_IP)
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printf("! ");
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printf("%s%s ", xtables_ipaddr_to_numeric((const struct in_addr*) &arpinfo->daddr),
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xtables_ipmask_to_numeric((const struct in_addr*)&arpinfo->dmsk));
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}
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if (arpinfo->bitmask & EBT_ARP_SRC_MAC) {
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printf("--arp-mac-src ");
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if (arpinfo->invflags & EBT_ARP_SRC_MAC)
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printf("! ");
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xtables_print_mac_and_mask(arpinfo->smaddr, arpinfo->smmsk);
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printf(" ");
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}
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if (arpinfo->bitmask & EBT_ARP_DST_MAC) {
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printf("--arp-mac-dst ");
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if (arpinfo->invflags & EBT_ARP_DST_MAC)
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printf("! ");
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xtables_print_mac_and_mask(arpinfo->dmaddr, arpinfo->dmmsk);
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printf(" ");
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}
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if (arpinfo->bitmask & EBT_ARP_GRAT) {
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if (arpinfo->invflags & EBT_ARP_GRAT)
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printf("! ");
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printf("--arp-gratuitous ");
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}
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}
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static struct xtables_match brarp_match = {
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.name = "arp",
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.version = XTABLES_VERSION,
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.family = NFPROTO_BRIDGE,
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.size = XT_ALIGN(sizeof(struct ebt_arp_info)),
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.userspacesize = XT_ALIGN(sizeof(struct ebt_arp_info)),
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.help = brarp_print_help,
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.parse = brarp_parse,
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.print = brarp_print,
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.extra_opts = brarp_opts,
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};
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void _init(void)
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{
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xtables_register_match(&brarp_match);
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}
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