/* ebt_ip
*
* Authors:
* Bart De Schuymer <bdschuym@pandora.be>
*
* Changes:
* added ip-sport and ip-dport; parsing of port arguments is
* based on code from iptables-1.2.7a
* Innominate Security Technologies AG <mhopf@innominate.com>
* September, 2002
*
* Adapted by Arturo Borrero Gonzalez <arturo@debian.org>
* to use libxtables for ebtables-compat in 2015.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <getopt.h>
#include <netdb.h>
#include <inttypes.h>
#include <xtables.h>
#include "libxt_icmp.h"
#define EBT_IP_SOURCE 0x01
#define EBT_IP_DEST 0x02
#define EBT_IP_TOS 0x04
#define EBT_IP_PROTO 0x08
#define EBT_IP_SPORT 0x10
#define EBT_IP_DPORT 0x20
#define EBT_IP_ICMP 0x40
#define EBT_IP_IGMP 0x80
#define EBT_IP_MASK (EBT_IP_SOURCE | EBT_IP_DEST | EBT_IP_TOS | EBT_IP_PROTO |\
EBT_IP_SPORT | EBT_IP_DPORT | EBT_IP_ICMP | EBT_IP_IGMP)
struct ebt_ip_info {
__be32 saddr;
__be32 daddr;
__be32 smsk;
__be32 dmsk;
__u8 tos;
__u8 protocol;
__u8 bitmask;
__u8 invflags;
union {
__u16 sport[2];
__u8 icmp_type[2];
__u8 igmp_type[2];
};
union {
__u16 dport[2];
__u8 icmp_code[2];
};
};
#define IP_SOURCE '1'
#define IP_DEST '2'
#define IP_EBT_TOS '3' /* include/bits/in.h seems to already define IP_TOS */
#define IP_PROTO '4'
#define IP_SPORT '5'
#define IP_DPORT '6'
#define IP_EBT_ICMP '7'
#define IP_EBT_IGMP '8'
static const struct option brip_opts[] = {
{ .name = "ip-source", .has_arg = true, .val = IP_SOURCE },
{ .name = "ip-src", .has_arg = true, .val = IP_SOURCE },
{ .name = "ip-destination", .has_arg = true, .val = IP_DEST },
{ .name = "ip-dst", .has_arg = true, .val = IP_DEST },
{ .name = "ip-tos", .has_arg = true, .val = IP_EBT_TOS },
{ .name = "ip-protocol", .has_arg = true, .val = IP_PROTO },
{ .name = "ip-proto", .has_arg = true, .val = IP_PROTO },
{ .name = "ip-source-port", .has_arg = true, .val = IP_SPORT },
{ .name = "ip-sport", .has_arg = true, .val = IP_SPORT },
{ .name = "ip-destination-port",.has_arg = true, .val = IP_DPORT },
{ .name = "ip-dport", .has_arg = true, .val = IP_DPORT },
{ .name = "ip-icmp-type", .has_arg = true, .val = IP_EBT_ICMP },
{ .name = "ip-igmp-type", .has_arg = true, .val = IP_EBT_IGMP },
XT_GETOPT_TABLEEND,
};
static const struct xt_icmp_names icmp_codes[] = {
{ "echo-reply", 0, 0, 0xFF },
/* Alias */ { "pong", 0, 0, 0xFF },
{ "destination-unreachable", 3, 0, 0xFF },
{ "network-unreachable", 3, 0, 0 },
{ "host-unreachable", 3, 1, 1 },
{ "protocol-unreachable", 3, 2, 2 },
{ "port-unreachable", 3, 3, 3 },
{ "fragmentation-needed", 3, 4, 4 },
{ "source-route-failed", 3, 5, 5 },
{ "network-unknown", 3, 6, 6 },
{ "host-unknown", 3, 7, 7 },
{ "network-prohibited", 3, 9, 9 },
{ "host-prohibited", 3, 10, 10 },
{ "TOS-network-unreachable", 3, 11, 11 },
{ "TOS-host-unreachable", 3, 12, 12 },
{ "communication-prohibited", 3, 13, 13 },
{ "host-precedence-violation", 3, 14, 14 },
{ "precedence-cutoff", 3, 15, 15 },
{ "source-quench", 4, 0, 0xFF },
{ "redirect", 5, 0, 0xFF },
{ "network-redirect", 5, 0, 0 },
{ "host-redirect", 5, 1, 1 },
{ "TOS-network-redirect", 5, 2, 2 },
{ "TOS-host-redirect", 5, 3, 3 },
{ "echo-request", 8, 0, 0xFF },
/* Alias */ { "ping", 8, 0, 0xFF },
{ "router-advertisement", 9, 0, 0xFF },
{ "router-solicitation", 10, 0, 0xFF },
{ "time-exceeded", 11, 0, 0xFF },
/* Alias */ { "ttl-exceeded", 11, 0, 0xFF },
{ "ttl-zero-during-transit", 11, 0, 0 },
{ "ttl-zero-during-reassembly", 11, 1, 1 },
{ "parameter-problem", 12, 0, 0xFF },
{ "ip-header-bad", 12, 0, 0 },
{ "required-option-missing", 12, 1, 1 },
{ "timestamp-request", 13, 0, 0xFF },
{ "timestamp-reply", 14, 0, 0xFF },
{ "address-mask-request", 17, 0, 0xFF },
{ "address-mask-reply", 18, 0, 0xFF }
};
static const struct xt_icmp_names igmp_types[] = {
{ "membership-query", 0x11 },
{ "membership-report-v1", 0x12 },
{ "membership-report-v2", 0x16 },
{ "leave-group", 0x17 },
{ "membership-report-v3", 0x22 },
};
static void brip_print_help(void)
{
printf(
"ip options:\n"
"--ip-src [!] address[/mask]: ip source specification\n"
"--ip-dst [!] address[/mask]: ip destination specification\n"
"--ip-tos [!] tos : ip tos specification\n"
"--ip-proto [!] protocol : ip protocol specification\n"
"--ip-sport [!] port[:port] : tcp/udp source port or port range\n"
"--ip-dport [!] port[:port] : tcp/udp destination port or port range\n"
"--ip-icmp-type [!] type[[:type]/code[:code]] : icmp type/code or type/code range\n"
"--ip-igmp-type [!] type[:type] : igmp type or type range\n");
printf("\nValid ICMP Types:\n");
xt_print_icmp_types(icmp_codes, ARRAY_SIZE(icmp_codes));
printf("\nValid IGMP Types:\n");
xt_print_icmp_types(igmp_types, ARRAY_SIZE(igmp_types));
}
static void brip_init(struct xt_entry_match *match)
{
struct ebt_ip_info *info = (struct ebt_ip_info *)match->data;
info->invflags = 0;
info->bitmask = 0;
}
static void
parse_port_range(const char *protocol, const char *portstring, uint16_t *ports)
{
char *buffer;
char *cp;
buffer = strdup(portstring);
if ((cp = strchr(buffer, ':')) == NULL)
ports[0] = ports[1] = xtables_parse_port(buffer, NULL);
else {
*cp = '\0';
cp++;
ports[0] = buffer[0] ? xtables_parse_port(buffer, NULL) : 0;
ports[1] = cp[0] ? xtables_parse_port(cp, NULL) : 0xFFFF;
if (ports[0] > ports[1])
xtables_error(PARAMETER_PROBLEM,
"invalid portrange (min > max)");
}
free(buffer);
}
/* original code from ebtables: useful_functions.c */
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 char *parse_range(const char *str, unsigned int res[])
{
char *next;
if (!xtables_strtoui(str, &next, &res[0], 0, 255))
return NULL;
res[1] = res[0];
if (*next == ':') {
str = next + 1;
if (!xtables_strtoui(str, &next, &res[1], 0, 255))
return NULL;
}
return next;
}
static int ebt_parse_icmp(const struct xt_icmp_names *codes, size_t n_codes,
const char *icmptype, uint8_t type[], uint8_t code[])
{
unsigned int match = n_codes;
unsigned int i, number[2];
for (i = 0; i < n_codes; i++) {
if (strncasecmp(codes[i].name, icmptype, strlen(icmptype)))
continue;
if (match != n_codes)
xtables_error(PARAMETER_PROBLEM, "Ambiguous ICMP type `%s':"
" `%s' or `%s'?",
icmptype, codes[match].name,
codes[i].name);
match = i;
}
if (match < n_codes) {
type[0] = type[1] = codes[match].type;
if (code) {
code[0] = codes[match].code_min;
code[1] = codes[match].code_max;
}
} else {
char *next = parse_range(icmptype, number);
if (!next) {
xtables_error(PARAMETER_PROBLEM, "Unknown ICMP type `%s'",
icmptype);
return -1;
}
type[0] = (uint8_t) number[0];
type[1] = (uint8_t) number[1];
switch (*next) {
case 0:
if (code) {
code[0] = 0;
code[1] = 255;
}
return 0;
case '/':
if (code) {
next = parse_range(next+1, number);
code[0] = (uint8_t) number[0];
code[1] = (uint8_t) number[1];
if (next == NULL)
return -1;
if (next && *next == 0)
return 0;
}
/* fallthrough */
default:
xtables_error(PARAMETER_PROBLEM, "unknown character %c", *next);
return -1;
}
}
return 0;
}
static void print_icmp_code(uint8_t *code)
{
if (!code)
return;
if (code[0] == code[1])
printf("/%"PRIu8 " ", code[0]);
else
printf("/%"PRIu8":%"PRIu8 " ", code[0], code[1]);
}
static void ebt_print_icmp_type(const struct xt_icmp_names *codes,
size_t n_codes, uint8_t *type, uint8_t *code)
{
unsigned int i;
if (type[0] != type[1]) {
printf("%"PRIu8 ":%" PRIu8, type[0], type[1]);
print_icmp_code(code);
return;
}
for (i = 0; i < n_codes; i++) {
if (codes[i].type != type[0])
continue;
if (!code || (codes[i].code_min == code[0] &&
codes[i].code_max == code[1])) {
printf("%s ", codes[i].name);
return;
}
}
printf("%"PRIu8, type[0]);
print_icmp_code(code);
}
static int
brip_parse(int c, char **argv, int invert, unsigned int *flags,
const void *entry, struct xt_entry_match **match)
{
struct ebt_ip_info *info = (struct ebt_ip_info *)(*match)->data;
switch (c) {
case IP_SOURCE:
if (invert)
info->invflags |= EBT_IP_SOURCE;
ebt_parse_ip_address(optarg, &info->saddr, &info->smsk);
info->bitmask |= EBT_IP_SOURCE;
break;
case IP_DEST:
if (invert)
info->invflags |= EBT_IP_DEST;
ebt_parse_ip_address(optarg, &info->daddr, &info->dmsk);
info->bitmask |= EBT_IP_DEST;
break;
case IP_SPORT:
if (invert)
info->invflags |= EBT_IP_SPORT;
parse_port_range(NULL, optarg, info->sport);
info->bitmask |= EBT_IP_SPORT;
break;
case IP_DPORT:
if (invert)
info->invflags |= EBT_IP_DPORT;
parse_port_range(NULL, optarg, info->dport);
info->bitmask |= EBT_IP_DPORT;
break;
case IP_EBT_ICMP:
if (invert)
info->invflags |= EBT_IP_ICMP;
ebt_parse_icmp(icmp_codes, ARRAY_SIZE(icmp_codes), optarg,
info->icmp_type, info->icmp_code);
info->bitmask |= EBT_IP_ICMP;
break;
case IP_EBT_IGMP:
if (invert)
info->invflags |= EBT_IP_IGMP;
ebt_parse_icmp(igmp_types, ARRAY_SIZE(igmp_types), optarg,
info->igmp_type, NULL);
info->bitmask |= EBT_IP_IGMP;
break;
case IP_EBT_TOS: {
uintmax_t tosvalue;
if (invert)
info->invflags |= EBT_IP_TOS;
if (!xtables_strtoul(optarg, NULL, &tosvalue, 0, 255))
xtables_error(PARAMETER_PROBLEM,
"Problem with specified IP tos");
info->tos = tosvalue;
info->bitmask |= EBT_IP_TOS;
}
break;
case IP_PROTO:
if (invert)
info->invflags |= EBT_IP_PROTO;
info->protocol = xtables_parse_protocol(optarg);
info->bitmask |= EBT_IP_PROTO;
break;
default:
return 0;
}
*flags |= info->bitmask;
return 1;
}
static void brip_final_check(unsigned int flags)
{
if (!flags)
xtables_error(PARAMETER_PROBLEM,
"You must specify proper arguments");
}
static void print_port_range(uint16_t *ports)
{
if (ports[0] == ports[1])
printf("%d ", ports[0]);
else
printf("%d:%d ", ports[0], ports[1]);
}
static void brip_print(const void *ip, const struct xt_entry_match *match,
int numeric)
{
struct ebt_ip_info *info = (struct ebt_ip_info *)match->data;
struct in_addr *addrp, *maskp;
if (info->bitmask & EBT_IP_SOURCE) {
printf("--ip-src ");
if (info->invflags & EBT_IP_SOURCE)
printf("! ");
addrp = (struct in_addr *)&info->saddr;
maskp = (struct in_addr *)&info->smsk;
printf("%s%s ", xtables_ipaddr_to_numeric(addrp),
xtables_ipmask_to_numeric(maskp));
}
if (info->bitmask & EBT_IP_DEST) {
printf("--ip-dst ");
if (info->invflags & EBT_IP_DEST)
printf("! ");
addrp = (struct in_addr *)&info->daddr;
maskp = (struct in_addr *)&info->dmsk;
printf("%s%s ", xtables_ipaddr_to_numeric(addrp),
xtables_ipmask_to_numeric(maskp));
}
if (info->bitmask & EBT_IP_TOS) {
printf("--ip-tos ");
if (info->invflags & EBT_IP_TOS)
printf("! ");
printf("0x%02X ", info->tos);
}
if (info->bitmask & EBT_IP_PROTO) {
struct protoent *pe;
printf("--ip-proto ");
if (info->invflags & EBT_IP_PROTO)
printf("! ");
pe = getprotobynumber(info->protocol);
if (pe == NULL) {
printf("%d ", info->protocol);
} else {
printf("%s ", pe->p_name);
}
}
if (info->bitmask & EBT_IP_SPORT) {
printf("--ip-sport ");
if (info->invflags & EBT_IP_SPORT)
printf("! ");
print_port_range(info->sport);
}
if (info->bitmask & EBT_IP_DPORT) {
printf("--ip-dport ");
if (info->invflags & EBT_IP_DPORT)
printf("! ");
print_port_range(info->dport);
}
if (info->bitmask & EBT_IP_ICMP) {
printf("--ip-icmp-type ");
if (info->invflags & EBT_IP_ICMP)
printf("! ");
ebt_print_icmp_type(icmp_codes, ARRAY_SIZE(icmp_codes),
info->icmp_type, info->icmp_code);
}
if (info->bitmask & EBT_IP_IGMP) {
printf("--ip-igmp-type ");
if (info->invflags & EBT_IP_IGMP)
printf("! ");
ebt_print_icmp_type(igmp_types, ARRAY_SIZE(igmp_types),
info->igmp_type, NULL);
}
}
static const char *brip_xlate_proto_to_name(uint8_t proto)
{
switch (proto) {
case IPPROTO_TCP:
return "tcp";
case IPPROTO_UDP:
return "udp";
case IPPROTO_UDPLITE:
return "udplite";
case IPPROTO_SCTP:
return "sctp";
case IPPROTO_DCCP:
return "dccp";
default:
return NULL;
}
}
static void brip_xlate_icmp(struct xt_xlate *xl,
const struct ebt_ip_info *info, int bit)
{
if ((info->bitmask & bit) == 0)
return;
xt_xlate_add(xl, "icmp type ");
if (info->invflags & bit)
xt_xlate_add(xl, "!= ");
if (info->icmp_type[0] == info->icmp_type[1])
xt_xlate_add(xl, "%d ", info->icmp_type[0]);
else
xt_xlate_add(xl, "%d-%d ", info->icmp_type[0],
info->icmp_type[1]);
if (info->icmp_code[0] == 0 &&
info->icmp_code[1] == 0xff)
return;
xt_xlate_add(xl, "icmp code ");
if (info->invflags & bit)
xt_xlate_add(xl, "!= ");
if (info->icmp_code[0] == info->icmp_code[1])
xt_xlate_add(xl, "%d ", info->icmp_code[0]);
else
xt_xlate_add(xl, "%d-%d ", info->icmp_code[0],
info->icmp_code[1]);
}
static void brip_xlate_igmp(struct xt_xlate *xl,
const struct ebt_ip_info *info, int bit)
{
if ((info->bitmask & bit) == 0)
return;
xt_xlate_add(xl, "@th,0,8 ");
if (info->invflags & bit)
xt_xlate_add(xl, "!= ");
if (info->icmp_type[0] == info->icmp_type[1])
xt_xlate_add(xl, "%d ", info->icmp_type[0]);
else
xt_xlate_add(xl, "%d-%d ", info->icmp_type[0],
info->icmp_type[1]);
}
static void brip_xlate_th(struct xt_xlate *xl,
const struct ebt_ip_info *info, int bit,
const char *pname)
{
const uint16_t *ports;
if ((info->bitmask & bit) == 0)
return;
switch (bit) {
case EBT_IP_SPORT:
if (pname)
xt_xlate_add(xl, "%s sport ", pname);
else
xt_xlate_add(xl, "@th,0,16 ");
ports = info->sport;
break;
case EBT_IP_DPORT:
if (pname)
xt_xlate_add(xl, "%s dport ", pname);
else
xt_xlate_add(xl, "@th,16,16 ");
ports = info->dport;
break;
default:
return;
}
if (info->invflags & bit)
xt_xlate_add(xl, "!= ");
if (ports[0] == ports[1])
xt_xlate_add(xl, "%d ", ports[0]);
else
xt_xlate_add(xl, "%d-%d ", ports[0], ports[1]);
}
static void brip_xlate_nh(struct xt_xlate *xl,
const struct ebt_ip_info *info, int bit)
{
struct in_addr *addrp, *maskp;
if ((info->bitmask & bit) == 0)
return;
switch (bit) {
case EBT_IP_SOURCE:
xt_xlate_add(xl, "ip saddr ");
addrp = (struct in_addr *)&info->saddr;
maskp = (struct in_addr *)&info->smsk;
break;
case EBT_IP_DEST:
xt_xlate_add(xl, "ip daddr ");
addrp = (struct in_addr *)&info->daddr;
maskp = (struct in_addr *)&info->dmsk;
break;
default:
return;
}
if (info->invflags & bit)
xt_xlate_add(xl, "!= ");
xt_xlate_add(xl, "%s%s ", xtables_ipaddr_to_numeric(addrp),
xtables_ipmask_to_numeric(maskp));
}
static int brip_xlate(struct xt_xlate *xl,
const struct xt_xlate_mt_params *params)
{
const struct ebt_ip_info *info = (const void *)params->match->data;
const char *pname = NULL;
brip_xlate_nh(xl, info, EBT_IP_SOURCE);
brip_xlate_nh(xl, info, EBT_IP_DEST);
if (info->bitmask & EBT_IP_TOS) {
xt_xlate_add(xl, "ip dscp ");
if (info->invflags & EBT_IP_TOS)
xt_xlate_add(xl, "!= ");
xt_xlate_add(xl, "0x%02x ", info->tos & 0x3f); /* remove ECN bits */
}
if (info->bitmask & EBT_IP_PROTO) {
struct protoent *pe;
if (info->bitmask & (EBT_IP_SPORT|EBT_IP_DPORT|EBT_IP_ICMP) &&
(info->invflags & EBT_IP_PROTO) == 0) {
/* port number or icmp given and not inverted, no need to print this */
pname = brip_xlate_proto_to_name(info->protocol);
} else {
xt_xlate_add(xl, "ip protocol ");
if (info->invflags & EBT_IP_PROTO)
xt_xlate_add(xl, "!= ");
pe = getprotobynumber(info->protocol);
if (pe == NULL)
xt_xlate_add(xl, "%d ", info->protocol);
else
xt_xlate_add(xl, "%s ", pe->p_name);
}
}
brip_xlate_th(xl, info, EBT_IP_SPORT, pname);
brip_xlate_th(xl, info, EBT_IP_DPORT, pname);
brip_xlate_icmp(xl, info, EBT_IP_ICMP);
brip_xlate_igmp(xl, info, EBT_IP_IGMP);
return 1;
}
static struct xtables_match brip_match = {
.name = "ip",
.revision = 0,
.version = XTABLES_VERSION,
.family = NFPROTO_BRIDGE,
.size = XT_ALIGN(sizeof(struct ebt_ip_info)),
.userspacesize = XT_ALIGN(sizeof(struct ebt_ip_info)),
.init = brip_init,
.help = brip_print_help,
.parse = brip_parse,
.final_check = brip_final_check,
.print = brip_print,
.xlate = brip_xlate,
.extra_opts = brip_opts,
};
void _init(void)
{
xtables_register_match(&brip_match);
}