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/* Copyright (C) 2007-2010 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>
*/
#ifndef __DECODE_ICMPV4_H__
#define __DECODE_ICMPV4_H__
#include "decode.h"
#include "decode-tcp.h"
#include "decode-sctp.h"
#include "decode-udp.h"
#define ICMPV4_HEADER_LEN 8
#ifndef ICMP_ECHOREPLY
#define ICMP_ECHOREPLY 0 /* Echo Reply */
#endif
#ifndef ICMP_DEST_UNREACH
#define ICMP_DEST_UNREACH 3 /* Destination Unreachable */
#endif
#ifndef ICMP_SOURCE_QUENCH
#define ICMP_SOURCE_QUENCH 4 /* Source Quench */
#endif
#ifndef ICMP_REDIRECT
#define ICMP_REDIRECT 5 /* Redirect (change route) */
#endif
#ifndef ICMP_ECHO
#define ICMP_ECHO 8 /* Echo Request */
#endif
#ifndef ICMP_TIME_EXCEEDED
#define ICMP_TIME_EXCEEDED 11 /* Time Exceeded */
#endif
#ifndef ICMP_PARAMETERPROB
#define ICMP_PARAMETERPROB 12 /* Parameter Problem */
#endif
#ifndef ICMP_TIMESTAMP
#define ICMP_TIMESTAMP 13 /* Timestamp Request */
#endif
#ifndef ICMP_TIMESTAMPREPLY
#define ICMP_TIMESTAMPREPLY 14 /* Timestamp Reply */
#endif
#ifndef ICMP_INFO_REQUEST
#define ICMP_INFO_REQUEST 15 /* Information Request */
#endif
#ifndef ICMP_INFO_REPLY
#define ICMP_INFO_REPLY 16 /* Information Reply */
#endif
#ifndef ICMP_ADDRESS
#define ICMP_ADDRESS 17 /* Address Mask Request */
#endif
#ifndef ICMP_ADDRESSREPLY
#define ICMP_ADDRESSREPLY 18 /* Address Mask Reply */
#endif
#ifndef NR_ICMP_TYPES
#define NR_ICMP_TYPES 18
#endif
/* Codes for UNREACH. */
#ifndef ICMP_NET_UNREACH
#define ICMP_NET_UNREACH 0 /* Network Unreachable */
#endif
#ifndef ICMP_HOST_UNREACH
#define ICMP_HOST_UNREACH 1 /* Host Unreachable */
#endif
#ifndef ICMP_PROT_UNREACH
#define ICMP_PROT_UNREACH 2 /* Protocol Unreachable */
#endif
#ifndef ICMP_PORT_UNREACH
#define ICMP_PORT_UNREACH 3 /* Port Unreachable */
#endif
#ifndef ICMP_FRAG_NEEDED
#define ICMP_FRAG_NEEDED 4 /* Fragmentation Needed/DF set */
#endif
#ifndef ICMP_SR_FAILED
#define ICMP_SR_FAILED 5 /* Source Route failed */
#endif
#ifndef ICMP_NET_UNKNOWN
#define ICMP_NET_UNKNOWN 6
#endif
#ifndef ICMP_HOST_UNKNOWN
#define ICMP_HOST_UNKNOWN 7
#endif
#ifndef ICMP_HOST_ISOLATED
#define ICMP_HOST_ISOLATED 8
#endif
#ifndef ICMP_NET_ANO
#define ICMP_NET_ANO 9
#endif
#ifndef ICMP_HOST_ANO
#define ICMP_HOST_ANO 10
#endif
#ifndef ICMP_NET_UNR_TOS
#define ICMP_NET_UNR_TOS 11
#endif
#ifndef ICMP_HOST_UNR_TOS
#define ICMP_HOST_UNR_TOS 12
#endif
#ifndef ICMP_PKT_FILTERED
#define ICMP_PKT_FILTERED 13 /* Packet filtered */
#endif
#ifndef ICMP_PREC_VIOLATION
#define ICMP_PREC_VIOLATION 14 /* Precedence violation */
#endif
#ifndef ICMP_PREC_CUTOFF
#define ICMP_PREC_CUTOFF 15 /* Precedence cut off */
#endif
#ifndef NR_ICMP_UNREACH
#define NR_ICMP_UNREACH 15 /* instead of hardcoding immediate value */
#endif
/* Codes for REDIRECT. */
#ifndef ICMP_REDIR_NET
#define ICMP_REDIR_NET 0 /* Redirect Net */
#endif
#ifndef ICMP_REDIR_HOST
#define ICMP_REDIR_HOST 1 /* Redirect Host */
#endif
#ifndef ICMP_REDIR_NETTOS
#define ICMP_REDIR_NETTOS 2 /* Redirect Net for TOS */
#endif
#ifndef ICMP_REDIR_HOSTTOS
#define ICMP_REDIR_HOSTTOS 3 /* Redirect Host for TOS */
#endif
/* Codes for TIME_EXCEEDED. */
#ifndef ICMP_EXC_TTL
#define ICMP_EXC_TTL 0 /* TTL count exceeded */
#endif
#ifndef ICMP_EXC_FRAGTIME
#define ICMP_EXC_FRAGTIME 1 /* Fragment Reass time exceeded */
#endif
/** marco for icmpv4 type access */
#define ICMPV4_GET_TYPE(p) (p)->icmpv4h->type
/** marco for icmpv4 code access */
#define ICMPV4_GET_CODE(p) (p)->icmpv4h->code
/* ICMPv4 header structure */
typedef struct ICMPV4Hdr_
{
uint8_t type;
uint8_t code;
uint16_t checksum;
} __attribute__((__packed__)) ICMPV4Hdr;
/* ICMPv4 header structure */
typedef struct ICMPV4ExtHdr_
{
uint8_t type;
uint8_t code;
uint16_t checksum;
uint16_t id;
uint16_t seq;
} ICMPV4ExtHdr;
/* ICMPv4 vars */
typedef struct ICMPV4Vars_
{
uint16_t id;
uint16_t seq;
uint32_t mtu;
uint32_t error_ptr;
/** Pointers to the embedded packet headers */
IPV4Hdr *emb_ipv4h;
TCPHdr *emb_tcph;
UDPHdr *emb_udph;
ICMPV4Hdr *emb_icmpv4h;
/** IPv4 src and dst address */
struct in_addr emb_ip4_src;
struct in_addr emb_ip4_dst;
uint8_t emb_ip4_hlen;
uint8_t emb_ip4_proto;
/** TCP/UDP ports */
uint16_t emb_sport;
uint16_t emb_dport;
} ICMPV4Vars;
#define CLEAR_ICMPV4_PACKET(p) do { \
(p)->level4_comp_csum = -1; \
(p)->icmpv4vars.id = 0; \
(p)->icmpv4vars.seq = 0; \
(p)->icmpv4vars.mtu = 0; \
(p)->icmpv4vars.error_ptr = 0; \
(p)->icmpv4vars.emb_ipv4h = NULL; \
(p)->icmpv4vars.emb_tcph = NULL; \
(p)->icmpv4vars.emb_udph = NULL; \
(p)->icmpv4vars.emb_icmpv4h = NULL; \
(p)->icmpv4vars.emb_ip4_src.s_addr = 0; \
(p)->icmpv4vars.emb_ip4_dst.s_addr = 0; \
(p)->icmpv4vars.emb_sport = 0; \
(p)->icmpv4vars.emb_ip4_proto = 0; \
(p)->icmpv4vars.emb_sport = 0; \
(p)->icmpv4vars.emb_dport = 0; \
(p)->icmpv4h = NULL; \
} while(0)
#define ICMPV4_HEADER_PKT_OFFSET 8
/** macro for icmpv4 "type" access */
#define ICMPV4_GET_TYPE(p) (p)->icmpv4h->type
/** macro for icmpv4 "code" access */
#define ICMPV4_GET_CODE(p) (p)->icmpv4h->code
/** macro for icmpv4 "csum" access */
#define ICMPV4_GET_CSUM(p) (p)->icmpv4h->csum
/* If message is informational */
/** macro for icmpv4 "id" access */
#define ICMPV4_GET_ID(p) ((p)->icmpv4vars.id)
/** macro for icmpv4 "seq" access */
#define ICMPV4_GET_SEQ(p) ((p)->icmpv4vars.seq)
/* If message is Error */
/** macro for icmpv4 "unused" access */
#define ICMPV4_GET_UNUSED(p) (p)->icmpv4h->icmpv4b.icmpv4e.unused
/** macro for icmpv4 "error_ptr" access */
#define ICMPV4_GET_ERROR_PTR(p) (p)->icmpv4h->icmpv4b.icmpv4e.error_ptr
/** macro for icmpv4 "mtu" access */
#define ICMPV4_GET_MTU(p) (p)->icmpv4h->icmpv4b.icmpv4e.mtu
/** macro for icmpv4 embedded "protocol" access */
#define ICMPV4_GET_EMB_PROTO(p) (p)->icmpv4vars.emb_ip4_proto
/** macro for icmpv4 embedded "ipv4h" header access */
#define ICMPV4_GET_EMB_IPV4(p) (p)->icmpv4vars.emb_ipv4h
/** macro for icmpv4 embedded "tcph" header access */
#define ICMPV4_GET_EMB_TCP(p) (p)->icmpv4vars.emb_tcph
/** macro for icmpv4 embedded "udph" header access */
#define ICMPV4_GET_EMB_UDP(p) (p)->icmpv4vars.emb_udph
/** macro for icmpv4 embedded "icmpv4h" header access */
#define ICMPV4_GET_EMB_ICMPV4H(p) (p)->icmpv4vars.emb_icmpv4h
/** macro for checking if a ICMP DEST UNREACH packet is valid for use
* in other parts of the engine, such as the flow engine.
*
* \warning use only _after_ the decoder has processed the packet
*/
#define ICMPV4_DEST_UNREACH_IS_VALID(p) (((p)->icmpv4h != NULL) && \
(ICMPV4_GET_TYPE((p)) == ICMP_DEST_UNREACH) && \
(ICMPV4_GET_EMB_IPV4((p)) != NULL) && \
((ICMPV4_GET_EMB_TCP((p)) != NULL) || \
(ICMPV4_GET_EMB_UDP((p)) != NULL)))
/**
* marco for checking if a ICMP packet is an error message or an
* query message.
*
* \todo This check is used in the flow engine and needs to be as
* cheap as possible. Consider setting a bitflag at the decoder
* stage so we can to a bit check instead of the more expensive
* check below.
*/
#define ICMPV4_IS_ERROR_MSG(p) (ICMPV4_GET_TYPE((p)) == ICMP_DEST_UNREACH || \
ICMPV4_GET_TYPE((p)) == ICMP_SOURCE_QUENCH || \
ICMPV4_GET_TYPE((p)) == ICMP_REDIRECT || \
ICMPV4_GET_TYPE((p)) == ICMP_TIME_EXCEEDED || \
ICMPV4_GET_TYPE((p)) == ICMP_PARAMETERPROB)
typedef struct ICMPV4Cache_ {
} ICMPV4Cache;
void DecodeICMPV4RegisterTests(void);
/** ------ Inline functions ------ */
static inline uint16_t ICMPV4CalculateChecksum(uint16_t *, uint16_t);
/**
* \brief Calculates the checksum for the ICMP packet
*
* \param pkt Pointer to the start of the ICMP packet
* \param hlen Total length of the ICMP packet(header + payload)
*
* \retval csum Checksum for the ICMP packet
*/
static inline uint16_t ICMPV4CalculateChecksum(uint16_t *pkt, uint16_t tlen)
{
uint16_t pad = 0;
uint32_t csum = pkt[0];
tlen -= 4;
pkt += 2;
while (tlen >= 32) {
csum += pkt[0] + pkt[1] + pkt[2] + pkt[3] + pkt[4] + pkt[5] + pkt[6] +
pkt[7] + pkt[8] + pkt[9] + pkt[10] + pkt[11] + pkt[12] + pkt[13] +
pkt[14] + pkt[15];
tlen -= 32;
pkt += 16;
}
while(tlen >= 8) {
csum += pkt[0] + pkt[1] + pkt[2] + pkt[3];
tlen -= 8;
pkt += 4;
}
while(tlen >= 4) {
csum += pkt[0] + pkt[1];
tlen -= 4;
pkt += 2;
}
while (tlen > 1) {
csum += pkt[0];
tlen -= 2;
pkt += 1;
}
if (tlen == 1) {
*(uint8_t *)(&pad) = (*(uint8_t *)pkt);
csum += pad;
}
csum = (csum >> 16) + (csum & 0x0000FFFF);
csum += (csum >> 16);
return (uint16_t) ~csum;
}
#endif /* __DECODE_ICMPV4_H__ */
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