blob: d5035b956cc1529a9a4401a242d34fae3ec0eab1 [file] [log] [blame]
/* ebt_arp
*
* Authors:
* Bart De Schuymer <bdschuym@pandora.be>
* Tim Gardner <timg@tpi.com>
*
* April, 2002
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <getopt.h>
#include <xtables.h>
#include <netinet/ether.h>
#include <xtables.h>
#include <net/if_arp.h>
#include <linux/netfilter_bridge/ebt_arp.h>
#include "iptables/nft.h"
#include "iptables/nft-bridge.h"
#define ARP_OPCODE '1'
#define ARP_HTYPE '2'
#define ARP_PTYPE '3'
#define ARP_IP_S '4'
#define ARP_IP_D '5'
#define ARP_MAC_S '6'
#define ARP_MAC_D '7'
#define ARP_GRAT '8'
static const struct option brarp_opts[] = {
{ "arp-opcode" , required_argument, 0, ARP_OPCODE },
{ "arp-op" , required_argument, 0, ARP_OPCODE },
{ "arp-htype" , required_argument, 0, ARP_HTYPE },
{ "arp-ptype" , required_argument, 0, ARP_PTYPE },
{ "arp-ip-src" , required_argument, 0, ARP_IP_S },
{ "arp-ip-dst" , required_argument, 0, ARP_IP_D },
{ "arp-mac-src" , required_argument, 0, ARP_MAC_S },
{ "arp-mac-dst" , required_argument, 0, ARP_MAC_D },
{ "arp-gratuitous", no_argument, 0, ARP_GRAT },
XT_GETOPT_TABLEEND,
};
/* a few names */
static char *opcodes[] =
{
"Request",
"Reply",
"Request_Reverse",
"Reply_Reverse",
"DRARP_Request",
"DRARP_Reply",
"DRARP_Error",
"InARP_Request",
"ARP_NAK",
};
static void brarp_print_help(void)
{
int i;
printf(
"arp options:\n"
"--arp-opcode [!] opcode : ARP opcode (integer or string)\n"
"--arp-htype [!] type : ARP hardware type (integer or string)\n"
"--arp-ptype [!] type : ARP protocol type (hexadecimal or string)\n"
"--arp-ip-src [!] address[/mask]: ARP IP source specification\n"
"--arp-ip-dst [!] address[/mask]: ARP IP target specification\n"
"--arp-mac-src [!] address[/mask]: ARP MAC source specification\n"
"--arp-mac-dst [!] address[/mask]: ARP MAC target specification\n"
"[!] --arp-gratuitous : ARP gratuitous packet\n"
" opcode strings: \n");
for (i = 0; i < ARRAY_SIZE(opcodes); i++)
printf(" %d = %s\n", i + 1, opcodes[i]);
printf(
" hardware type string: 1 = Ethernet\n"
" protocol type string: see "XT_PATH_ETHERTYPES"\n");
}
#define OPT_OPCODE 0x01
#define OPT_HTYPE 0x02
#define OPT_PTYPE 0x04
#define OPT_IP_S 0x08
#define OPT_IP_D 0x10
#define OPT_MAC_S 0x20
#define OPT_MAC_D 0x40
#define OPT_GRAT 0x80
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;
}
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;
}
static 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)) {
xtables_error(PARAMETER_PROBLEM,
"Problem with the IP mask '%s'", p + 1);
return;
}
} else
*msk = 0xFFFFFFFF;
if (undot_ip(address, (unsigned char *)addr)) {
xtables_error(PARAMETER_PROBLEM,
"Problem with the IP address '%s'", address);
return;
}
*addr = *addr & *msk;
}
static int
brarp_parse(int c, char **argv, int invert, unsigned int *flags,
const void *entry, struct xt_entry_match **match)
{
struct ebt_arp_info *arpinfo = (struct ebt_arp_info *)(*match)->data;
long int i;
char *end;
uint32_t *addr;
uint32_t *mask;
unsigned char *maddr;
unsigned char *mmask;
switch (c) {
case ARP_OPCODE:
EBT_CHECK_OPTION(flags, OPT_OPCODE);
if (invert)
arpinfo->invflags |= EBT_ARP_OPCODE;
i = strtol(optarg, &end, 10);
if (i < 0 || i >= (0x1 << 16) || *end !='\0') {
for (i = 0; i < ARRAY_SIZE(opcodes); i++)
if (!strcasecmp(opcodes[i], optarg))
break;
if (i == ARRAY_SIZE(opcodes))
xtables_error(PARAMETER_PROBLEM, "Problem with specified ARP opcode");
i++;
}
arpinfo->opcode = htons(i);
arpinfo->bitmask |= EBT_ARP_OPCODE;
break;
case ARP_HTYPE:
EBT_CHECK_OPTION(flags, OPT_HTYPE);
if (invert)
arpinfo->invflags |= EBT_ARP_HTYPE;
i = strtol(optarg, &end, 10);
if (i < 0 || i >= (0x1 << 16) || *end !='\0') {
if (!strcasecmp("Ethernet", argv[optind - 1]))
i = 1;
else
xtables_error(PARAMETER_PROBLEM, "Problem with specified ARP hardware type");
}
arpinfo->htype = htons(i);
arpinfo->bitmask |= EBT_ARP_HTYPE;
break;
case ARP_PTYPE: {
uint16_t proto;
EBT_CHECK_OPTION(flags, OPT_PTYPE);
if (invert)
arpinfo->invflags |= EBT_ARP_PTYPE;
i = strtol(optarg, &end, 16);
if (i < 0 || i >= (0x1 << 16) || *end !='\0') {
struct xt_ethertypeent *ent;
ent = xtables_getethertypebyname(argv[optind - 1]);
if (!ent)
xtables_error(PARAMETER_PROBLEM, "Problem with specified ARP "
"protocol type");
proto = ent->e_ethertype;
} else
proto = i;
arpinfo->ptype = htons(proto);
arpinfo->bitmask |= EBT_ARP_PTYPE;
break;
}
case ARP_IP_S:
case ARP_IP_D:
if (c == ARP_IP_S) {
EBT_CHECK_OPTION(flags, OPT_IP_S);
addr = &arpinfo->saddr;
mask = &arpinfo->smsk;
arpinfo->bitmask |= EBT_ARP_SRC_IP;
} else {
EBT_CHECK_OPTION(flags, OPT_IP_D);
addr = &arpinfo->daddr;
mask = &arpinfo->dmsk;
arpinfo->bitmask |= EBT_ARP_DST_IP;
}
if (invert) {
if (c == ARP_IP_S)
arpinfo->invflags |= EBT_ARP_SRC_IP;
else
arpinfo->invflags |= EBT_ARP_DST_IP;
}
ebt_parse_ip_address(optarg, addr, mask);
break;
case ARP_MAC_S:
case ARP_MAC_D:
if (c == ARP_MAC_S) {
EBT_CHECK_OPTION(flags, OPT_MAC_S);
maddr = arpinfo->smaddr;
mmask = arpinfo->smmsk;
arpinfo->bitmask |= EBT_ARP_SRC_MAC;
} else {
EBT_CHECK_OPTION(flags, OPT_MAC_D);
maddr = arpinfo->dmaddr;
mmask = arpinfo->dmmsk;
arpinfo->bitmask |= EBT_ARP_DST_MAC;
}
if (invert) {
if (c == ARP_MAC_S)
arpinfo->invflags |= EBT_ARP_SRC_MAC;
else
arpinfo->invflags |= EBT_ARP_DST_MAC;
}
if (xtables_parse_mac_and_mask(optarg, maddr, mmask))
xtables_error(PARAMETER_PROBLEM, "Problem with ARP MAC address argument");
break;
case ARP_GRAT:
EBT_CHECK_OPTION(flags, OPT_GRAT);
arpinfo->bitmask |= EBT_ARP_GRAT;
if (invert)
arpinfo->invflags |= EBT_ARP_GRAT;
break;
default:
return 0;
}
return 1;
}
static void brarp_print(const void *ip, const struct xt_entry_match *match, int numeric)
{
const struct ebt_arp_info *arpinfo = (struct ebt_arp_info *)match->data;
if (arpinfo->bitmask & EBT_ARP_OPCODE) {
int opcode = ntohs(arpinfo->opcode);
printf("--arp-op ");
if (arpinfo->invflags & EBT_ARP_OPCODE)
printf("! ");
if (opcode > 0 && opcode <= ARRAY_SIZE(opcodes))
printf("%s ", opcodes[opcode - 1]);
else
printf("%d ", opcode);
}
if (arpinfo->bitmask & EBT_ARP_HTYPE) {
printf("--arp-htype ");
if (arpinfo->invflags & EBT_ARP_HTYPE)
printf("! ");
printf("%d ", ntohs(arpinfo->htype));
}
if (arpinfo->bitmask & EBT_ARP_PTYPE) {
printf("--arp-ptype ");
if (arpinfo->invflags & EBT_ARP_PTYPE)
printf("! ");
printf("0x%x ", ntohs(arpinfo->ptype));
}
if (arpinfo->bitmask & EBT_ARP_SRC_IP) {
printf("--arp-ip-src ");
if (arpinfo->invflags & EBT_ARP_SRC_IP)
printf("! ");
printf("%s%s ", xtables_ipaddr_to_numeric((const struct in_addr*) &arpinfo->saddr),
xtables_ipmask_to_numeric((const struct in_addr*)&arpinfo->smsk));
}
if (arpinfo->bitmask & EBT_ARP_DST_IP) {
printf("--arp-ip-dst ");
if (arpinfo->invflags & EBT_ARP_DST_IP)
printf("! ");
printf("%s%s ", xtables_ipaddr_to_numeric((const struct in_addr*) &arpinfo->daddr),
xtables_ipmask_to_numeric((const struct in_addr*)&arpinfo->dmsk));
}
if (arpinfo->bitmask & EBT_ARP_SRC_MAC) {
printf("--arp-mac-src ");
if (arpinfo->invflags & EBT_ARP_SRC_MAC)
printf("! ");
xtables_print_mac_and_mask(arpinfo->smaddr, arpinfo->smmsk);
printf(" ");
}
if (arpinfo->bitmask & EBT_ARP_DST_MAC) {
printf("--arp-mac-dst ");
if (arpinfo->invflags & EBT_ARP_DST_MAC)
printf("! ");
xtables_print_mac_and_mask(arpinfo->dmaddr, arpinfo->dmmsk);
printf(" ");
}
if (arpinfo->bitmask & EBT_ARP_GRAT) {
if (arpinfo->invflags & EBT_ARP_GRAT)
printf("! ");
printf("--arp-gratuitous ");
}
}
static struct xtables_match brarp_match = {
.name = "arp",
.version = XTABLES_VERSION,
.family = NFPROTO_BRIDGE,
.size = XT_ALIGN(sizeof(struct ebt_arp_info)),
.userspacesize = XT_ALIGN(sizeof(struct ebt_arp_info)),
.help = brarp_print_help,
.parse = brarp_parse,
.print = brarp_print,
.extra_opts = brarp_opts,
};
void _init(void)
{
xtables_register_match(&brarp_match);
}