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suricata/src/respond-reject-libnet11.c

548 lines
19 KiB
C

/* Copyright (C) 2007-2013 Open Information Security Foundation
*
* You can copy, redistribute or modify this Program under the terms of
* the GNU General Public License version 2 as published by the Free
* Software Foundation.
*
* 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
* version 2 along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*/
/**
* \file
*
* \author Victor Julien <victor@inliniac.net>
* \author William Metcalf <william.metcalf@gmail.com>
*
* RespondRejectLibnet11 used to send out libnet based
* TCP resets and ICMP unreachables.
*
* \todo calculate TTL base on average from stream tracking
* \todo come up with a way for users to specify icmp unreachable type
* \todo Possibly default to port unreachable for UDP traffic this seems
* to be the default in flexresp and iptables
* \todo implement ipv6 resets
* \todo implement pre-alloc resets for speed
*/
#include "suricata-common.h"
#include "decode.h"
#include "decode-ipv4.h"
#include "decode-tcp.h"
#include "decode-sctp.h"
#include "decode-udp.h"
#include "packet-queue.h"
#include "threads.h"
#include "threadvars.h"
#include "tm-queuehandlers.h"
#include "tm-threads.h"
#include "action-globals.h"
#include "respond-reject.h"
#include "respond-reject-libnet11.h"
#include "util-device.h"
#ifdef HAVE_LIBNET11
#ifndef HAVE_LIBNET_INIT_CONST
#define LIBNET_INIT_CAST (char *)
#else
#define LIBNET_INIT_CAST
#endif
/** set to true in main if we're setting caps. We need it here if we're using
* reject rules as libnet 1.1 is not compatible with caps. */
extern int sc_set_caps;
#include <libnet.h>
extern uint8_t host_mode;
typedef struct Libnet11Packet_ {
uint32_t ack, seq;
uint16_t window, dsize;
uint8_t ttl;
uint16_t id;
uint32_t flow;
uint8_t class;
struct libnet_in6_addr src6, dst6;
uint32_t src4, dst4;
uint16_t sp, dp;
size_t len;
} Libnet11Packet;
int RejectSendLibnet11L3IPv4TCP(ThreadVars *tv, Packet *p, void *data, int dir)
{
Libnet11Packet lpacket;
libnet_t *c; /* libnet context */
char ebuf[LIBNET_ERRBUF_SIZE];
int result;
const char *devname = NULL;
/* fill in struct defaults */
lpacket.ttl = 0;
lpacket.id = 0;
lpacket.flow = 0;
lpacket.class = 0;
if (IS_SURI_HOST_MODE_SNIFFER_ONLY(host_mode) && (p->livedev)) {
devname = p->livedev->dev;
SCLogDebug("Will emit reject packet on dev %s", devname);
}
if ((c = libnet_init(LIBNET_RAW4, LIBNET_INIT_CAST devname, ebuf)) == NULL) {
SCLogError(SC_ERR_LIBNET_INIT,"libnet_init failed: %s", ebuf);
return 1;
}
if (p->tcph == NULL)
return 1;
/* save payload len */
lpacket.dsize = p->payload_len;
switch (dir) {
case REJECT_DIR_SRC:
SCLogDebug("sending a tcp reset to src");
/* We follow http://tools.ietf.org/html/rfc793#section-3.4 :
* If packet has no ACK, the seq number is 0 and the ACK is built
* the normal way. If packet has a ACK, the seq of the RST packet
* is equal to the ACK of incoming packet and the ACK is build
* using packet sequence number and size of the data. */
if (TCP_GET_ACK(p) == 0) {
lpacket.seq = 0;
lpacket.ack = TCP_GET_SEQ(p) + lpacket.dsize + 1;
} else {
lpacket.seq = TCP_GET_ACK(p);
lpacket.ack = TCP_GET_SEQ(p) + lpacket.dsize;
}
lpacket.sp = TCP_GET_DST_PORT(p);
lpacket.dp = TCP_GET_SRC_PORT(p);
lpacket.src4 = GET_IPV4_DST_ADDR_U32(p);
lpacket.dst4 = GET_IPV4_SRC_ADDR_U32(p);
break;
case REJECT_DIR_DST:
SCLogDebug("sending a tcp reset to dst");
lpacket.seq = TCP_GET_SEQ(p);
lpacket.ack = TCP_GET_ACK(p);
lpacket.sp = TCP_GET_SRC_PORT(p);
lpacket.dp = TCP_GET_DST_PORT(p);
lpacket.src4 = GET_IPV4_SRC_ADDR_U32(p);
lpacket.dst4 = GET_IPV4_DST_ADDR_U32(p);
break;
default:
SCLogError(SC_ERR_LIBNET_INVALID_DIR,
"reset not src or dst returning");
return 1;
}
lpacket.window = TCP_GET_WINDOW(p);
//lpacket.seq += lpacket.dsize;
/* TODO come up with ttl calc function */
lpacket.ttl = 64;
/* build the package */
if ((libnet_build_tcp(
lpacket.sp, /* source port */
lpacket.dp, /* dst port */
lpacket.seq, /* seq number */
lpacket.ack, /* ack number */
TH_RST|TH_ACK, /* flags */
lpacket.window, /* window size */
0, /* checksum */
0, /* urgent flag */
LIBNET_TCP_H, /* header length */
NULL, /* payload */
0, /* payload length */
c, /* libnet context */
0)) < 0) /* libnet ptag */
{
SCLogError(SC_ERR_LIBNET_BUILD_FAILED,"libnet_build_tcp %s", libnet_geterror(c));
goto cleanup;
}
if ((libnet_build_ipv4(
LIBNET_TCP_H + LIBNET_IPV4_H, /* entire packet length */
0, /* tos */
lpacket.id, /* ID */
0, /* fragmentation flags and offset */
lpacket.ttl, /* TTL */
IPPROTO_TCP, /* protocol */
0, /* checksum */
lpacket.src4, /* source address */
lpacket.dst4, /* destination address */
NULL, /* pointer to packet data (or NULL) */
0, /* payload length */
c, /* libnet context pointer */
0)) < 0) /* packet id */
{
SCLogError(SC_ERR_LIBNET_BUILD_FAILED,"libnet_build_ipv4 %s", libnet_geterror(c));
goto cleanup;
}
result = libnet_write(c);
if (result == -1) {
SCLogError(SC_ERR_LIBNET_WRITE_FAILED,"libnet_write failed: %s", libnet_geterror(c));
goto cleanup;
}
cleanup:
libnet_destroy (c);
return 0;
}
int RejectSendLibnet11L3IPv4ICMP(ThreadVars *tv, Packet *p, void *data, int dir)
{
Libnet11Packet lpacket;
libnet_t *c; /* libnet context */
char ebuf[LIBNET_ERRBUF_SIZE];
int result;
const char *devname = NULL;
/* fill in struct defaults */
lpacket.ttl = 0;
lpacket.id = 0;
lpacket.flow = 0;
lpacket.class = 0;
lpacket.len = (IPV4_GET_HLEN(p) + p->payload_len);
if (IS_SURI_HOST_MODE_SNIFFER_ONLY(host_mode) && (p->livedev)) {
devname = p->livedev->dev;
}
if ((c = libnet_init(LIBNET_RAW4, LIBNET_INIT_CAST devname, ebuf)) == NULL) {
SCLogError(SC_ERR_LIBNET_INIT,"libnet_inint failed: %s", ebuf);
return 1;
}
switch (dir) {
case REJECT_DIR_SRC:
lpacket.src4 = GET_IPV4_DST_ADDR_U32(p);
lpacket.dst4 = GET_IPV4_SRC_ADDR_U32(p);
break;
case REJECT_DIR_DST:
lpacket.src4 = GET_IPV4_SRC_ADDR_U32(p);
lpacket.dst4 = GET_IPV4_DST_ADDR_U32(p);
break;
default:
SCLogError(SC_ERR_LIBNET_INVALID_DIR,
"reset not src or dst returning");
return 1;
}
/* TODO come up with ttl calc function */
lpacket.ttl = 64;
/* build the package */
if ((libnet_build_icmpv4_unreach(
ICMP_DEST_UNREACH, /* type */
ICMP_HOST_ANO, /* code */
0, /* checksum */
(uint8_t *)p->ip4h, /* payload */
lpacket.len, /* payload length */
c, /* libnet context */
0)) < 0) /* libnet ptag */
{
SCLogError(SC_ERR_LIBNET_BUILD_FAILED,"libnet_build_icmpv4_unreach %s", libnet_geterror(c));
goto cleanup;
}
if ((libnet_build_ipv4(
LIBNET_ICMPV4_H + LIBNET_IPV4_H +
lpacket.len, /* entire packet length */
0, /* tos */
lpacket.id, /* ID */
0, /* fragmentation flags and offset */
lpacket.ttl, /* TTL */
IPPROTO_ICMP, /* protocol */
0, /* checksum */
lpacket.src4, /* source address */
lpacket.dst4, /* destination address */
NULL, /* pointer to packet data (or NULL) */
0, /* payload length */
c, /* libnet context pointer */
0)) < 0) /* packet id */
{
SCLogError(SC_ERR_LIBNET_BUILD_FAILED,"libnet_build_ipv4 %s", libnet_geterror(c));
goto cleanup;
}
result = libnet_write(c);
if (result == -1) {
SCLogError(SC_ERR_LIBNET_WRITE_FAILED,"libnet_write_raw_ipv4 failed: %s", libnet_geterror(c));
goto cleanup;
}
cleanup:
libnet_destroy (c);
return 0;
}
int RejectSendLibnet11L3IPv6TCP(ThreadVars *tv, Packet *p, void *data, int dir)
{
Libnet11Packet lpacket;
libnet_t *c; /* libnet context */
char ebuf[LIBNET_ERRBUF_SIZE];
int result;
const char *devname = NULL;
/* fill in struct defaults */
lpacket.ttl = 0;
lpacket.id = 0;
lpacket.flow = 0;
lpacket.class = 0;
if (IS_SURI_HOST_MODE_SNIFFER_ONLY(host_mode) && (p->livedev)) {
devname = p->livedev->dev;
}
if ((c = libnet_init(LIBNET_RAW6, LIBNET_INIT_CAST devname, ebuf)) == NULL) {
SCLogError(SC_ERR_LIBNET_INIT,"libnet_init failed: %s", ebuf);
return 1;
}
if (p->tcph == NULL)
return 1;
/* save payload len */
lpacket.dsize = p->payload_len;
switch (dir) {
case REJECT_DIR_SRC:
SCLogDebug("sending a tcp reset to src");
/* We follow http://tools.ietf.org/html/rfc793#section-3.4 :
* If packet has no ACK, the seq number is 0 and the ACK is built
* the normal way. If packet has a ACK, the seq of the RST packet
* is equal to the ACK of incoming packet and the ACK is build
* using packet sequence number and size of the data. */
if (TCP_GET_ACK(p) == 0) {
lpacket.seq = 0;
lpacket.ack = TCP_GET_SEQ(p) + lpacket.dsize + 1;
} else {
lpacket.seq = TCP_GET_ACK(p);
lpacket.ack = TCP_GET_SEQ(p) + lpacket.dsize;
}
lpacket.sp = TCP_GET_DST_PORT(p);
lpacket.dp = TCP_GET_SRC_PORT(p);
memcpy(lpacket.src6.libnet_s6_addr, GET_IPV6_DST_ADDR(p), 16);
memcpy(lpacket.dst6.libnet_s6_addr, GET_IPV6_SRC_ADDR(p), 16);
break;
case REJECT_DIR_DST:
SCLogDebug("sending a tcp reset to dst");
lpacket.seq = TCP_GET_SEQ(p);
lpacket.ack = TCP_GET_ACK(p);
lpacket.sp = TCP_GET_SRC_PORT(p);
lpacket.dp = TCP_GET_DST_PORT(p);
memcpy(lpacket.src6.libnet_s6_addr, GET_IPV6_SRC_ADDR(p), 16);
memcpy(lpacket.dst6.libnet_s6_addr, GET_IPV6_DST_ADDR(p), 16);
break;
default:
SCLogError(SC_ERR_LIBNET_INVALID_DIR,
"reset not src or dst returning");
return 1;
}
lpacket.window = TCP_GET_WINDOW(p);
//lpacket.seq += lpacket.dsize;
/* TODO come up with ttl calc function */
lpacket.ttl = 64;
/* build the package */
if ((libnet_build_tcp(
lpacket.sp, /* source port */
lpacket.dp, /* dst port */
lpacket.seq, /* seq number */
lpacket.ack, /* ack number */
TH_RST|TH_ACK, /* flags */
lpacket.window, /* window size */
0, /* checksum */
0, /* urgent flag */
LIBNET_TCP_H, /* header length */
NULL, /* payload */
0, /* payload length */
c, /* libnet context */
0)) < 0) /* libnet ptag */
{
SCLogError(SC_ERR_LIBNET_BUILD_FAILED,"libnet_build_tcp %s", libnet_geterror(c));
goto cleanup;
}
if ((libnet_build_ipv6(
lpacket.class, /* traffic class */
lpacket.flow, /* Flow label */
LIBNET_TCP_H, /* payload length */
IPPROTO_TCP, /* next header */
lpacket.ttl, /* TTL */
lpacket.src6, /* source address */
lpacket.dst6, /* destination address */
NULL, /* pointer to packet data (or NULL) */
0, /* payload length */
c, /* libnet context pointer */
0)) < 0) /* packet id */
{
SCLogError(SC_ERR_LIBNET_BUILD_FAILED,"libnet_build_ipv6 %s", libnet_geterror(c));
goto cleanup;
}
result = libnet_write(c);
if (result == -1) {
SCLogError(SC_ERR_LIBNET_WRITE_FAILED,"libnet_write failed: %s", libnet_geterror(c));
goto cleanup;
}
cleanup:
libnet_destroy (c);
return 0;
}
#ifdef HAVE_LIBNET_ICMPV6_UNREACH
int RejectSendLibnet11L3IPv6ICMP(ThreadVars *tv, Packet *p, void *data, int dir)
{
Libnet11Packet lpacket;
libnet_t *c; /* libnet context */
char ebuf[LIBNET_ERRBUF_SIZE];
int result;
const char *devname = NULL;
/* fill in struct defaults */
lpacket.ttl = 0;
lpacket.id = 0;
lpacket.flow = 0;
lpacket.class = 0;
lpacket.len = IPV6_GET_PLEN(p) + IPV6_HEADER_LEN;
if (IS_SURI_HOST_MODE_SNIFFER_ONLY(host_mode) && (p->livedev)) {
devname = p->livedev->dev;
}
if ((c = libnet_init(LIBNET_RAW6, LIBNET_INIT_CAST devname, ebuf)) == NULL) {
SCLogError(SC_ERR_LIBNET_INIT,"libnet_inint failed: %s", ebuf);
return 1;
}
switch (dir) {
case REJECT_DIR_SRC:
memcpy(lpacket.src6.libnet_s6_addr, GET_IPV6_DST_ADDR(p), 16);
memcpy(lpacket.dst6.libnet_s6_addr, GET_IPV6_SRC_ADDR(p), 16);
break;
case REJECT_DIR_DST:
memcpy(lpacket.src6.libnet_s6_addr, GET_IPV6_SRC_ADDR(p), 16);
memcpy(lpacket.dst6.libnet_s6_addr, GET_IPV6_DST_ADDR(p), 16);
break;
default:
SCLogError(SC_ERR_LIBNET_INVALID_DIR,
"reset not src or dst returning");
return 1;
}
/* TODO come up with ttl calc function */
lpacket.ttl = 64;
/* build the package */
if ((libnet_build_icmpv6_unreach(
ICMP6_DST_UNREACH, /* type */
ICMP6_DST_UNREACH_ADMIN, /* code */
0, /* checksum */
(uint8_t *)p->ip6h, /* payload */
lpacket.len, /* payload length */
c, /* libnet context */
0)) < 0) /* libnet ptag */
{
SCLogError(SC_ERR_LIBNET_BUILD_FAILED,"libnet_build_icmpv6_unreach %s", libnet_geterror(c));
goto cleanup;
}
if ((libnet_build_ipv6(
lpacket.class, /* traffic class */
lpacket.flow, /* Flow label */
LIBNET_ICMPV6_H + lpacket.len, /* IPv6 payload length */
IPPROTO_ICMPV6, /* next header */
lpacket.ttl, /* TTL */
lpacket.src6, /* source address */
lpacket.dst6, /* destination address */
NULL, /* pointer to packet data (or NULL) */
0, /* payload length */
c, /* libnet context pointer */
0)) < 0) /* packet id */
{
SCLogError(SC_ERR_LIBNET_BUILD_FAILED,"libnet_build_ipv6 %s", libnet_geterror(c));
goto cleanup;
}
result = libnet_write(c);
if (result == -1) {
SCLogError(SC_ERR_LIBNET_WRITE_FAILED,"libnet_write_raw_ipv6 failed: %s", libnet_geterror(c));
goto cleanup;
}
cleanup:
libnet_destroy (c);
return 0;
}
#else /* HAVE_LIBNET_ICMPV6_UNREACH */
int RejectSendLibnet11L3IPv6ICMP(ThreadVars *tv, Packet *p, void *data, int dir)
{
SCLogError(SC_ERR_LIBNET_NOT_ENABLED, "Libnet ICMPv6 based rejects are disabled."
"Usually this means that you don't have a patched libnet installed,"
" or configure couldn't find it.");
return 0;
}
#endif /* HAVE_LIBNET_ICMPV6_UNREACH */
#else
int RejectSendLibnet11L3IPv4TCP(ThreadVars *tv, Packet *p, void *data, int dir)
{
SCLogError(SC_ERR_LIBNET_NOT_ENABLED, "Libnet based rejects are disabled."
"Usually this means that you don't have libnet installed,"
" or configure couldn't find it.");
return 0;
}
int RejectSendLibnet11L3IPv4ICMP(ThreadVars *tv, Packet *p, void *data, int dir)
{
SCLogError(SC_ERR_LIBNET_NOT_ENABLED, "Libnet based rejects are disabled."
"Usually this means that you don't have libnet installed,"
" or configure couldn't find it.");
return 0;
}
int RejectSendLibnet11L3IPv6TCP(ThreadVars *tv, Packet *p, void *data, int dir)
{
SCLogError(SC_ERR_LIBNET_NOT_ENABLED, "Libnet based rejects are disabled."
"Usually this means that you don't have libnet installed,"
" or configure couldn't find it.");
return 0;
}
int RejectSendLibnet11L3IPv6ICMP(ThreadVars *tv, Packet *p, void *data, int dir)
{
SCLogError(SC_ERR_LIBNET_NOT_ENABLED, "Libnet based rejects are disabled."
"Usually this means that you don't have libnet installed,"
" or configure couldn't find it.");
return 0;
}
#endif /* HAVE_LIBNET11 */