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Diffstat (limited to 'framework/src/suricata/src/decode-ipv4.h')
-rw-r--r-- | framework/src/suricata/src/decode-ipv4.h | 254 |
1 files changed, 254 insertions, 0 deletions
diff --git a/framework/src/suricata/src/decode-ipv4.h b/framework/src/suricata/src/decode-ipv4.h new file mode 100644 index 00000000..be212bf2 --- /dev/null +++ b/framework/src/suricata/src/decode-ipv4.h @@ -0,0 +1,254 @@ +/* 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 Brian Rectanus <brectanu@gmail.com> + */ + +#ifndef __DECODE_IPV4_H__ +#define __DECODE_IPV4_H__ + +#define IPV4_HEADER_LEN 20 /**< Header length */ +#define IPV4_OPTMAX 40 /**< Max options length */ +#define IPV4_MAXPACKET_LEN 65535 /**< Maximum packet size */ + +/** IP Option Types */ +#define IPV4_OPT_EOL 0x00 /**< Option: End of List */ +#define IPV4_OPT_NOP 0x01 /**< Option: No op */ +#define IPV4_OPT_RR 0x07 /**< Option: Record Route */ +#define IPV4_OPT_QS 0x19 /**< Option: Quick Start */ +#define IPV4_OPT_TS 0x44 /**< Option: Timestamp */ +#define IPV4_OPT_SEC 0x82 /**< Option: Security */ +#define IPV4_OPT_LSRR 0x83 /**< Option: Loose Source Route */ +#define IPV4_OPT_CIPSO 0x86 /**< Option: Commercial IP Security */ +#define IPV4_OPT_SID 0x88 /**< Option: Stream Identifier */ +#define IPV4_OPT_SSRR 0x89 /**< Option: Strict Source Route */ +#define IPV4_OPT_RTRALT 0x94 /**< Option: Router Alert */ + +/** IP Option Lengths (fixed) */ +#define IPV4_OPT_SEC_LEN 11 /**< SEC Option Fixed Length */ +#define IPV4_OPT_SID_LEN 4 /**< SID Option Fixed Length */ +#define IPV4_OPT_RTRALT_LEN 4 /**< RTRALT Option Fixed Length */ + +/** IP Option Lengths (variable) */ +#define IPV4_OPT_ROUTE_MIN 3 /**< RR, SRR, LTRR Option Min Length */ +#define IPV4_OPT_QS_MIN 8 /**< QS Option Min Length */ +#define IPV4_OPT_TS_MIN 5 /**< TS Option Min Length */ +#define IPV4_OPT_CIPSO_MIN 10 /**< CIPSO Option Min Length */ + +/** IP Option fields */ +#define IPV4_OPTS ip4vars.ip_opts +#define IPV4_OPTS_CNT ip4vars.ip_opt_cnt + +typedef struct IPV4Opt_ { + /** \todo We may want to break type up into its 3 fields + * as the reassembler may want to know which options + * must be copied to each fragment. + */ + uint8_t type; /**< option type */ + uint8_t len; /**< option length (type+len+data) */ + uint8_t *data; /**< option data */ +} IPV4Opt; + +typedef struct IPV4Hdr_ +{ + uint8_t ip_verhl; /**< version & header length */ + uint8_t ip_tos; /**< type of service */ + uint16_t ip_len; /**< length */ + uint16_t ip_id; /**< id */ + uint16_t ip_off; /**< frag offset */ + uint8_t ip_ttl; /**< time to live */ + uint8_t ip_proto; /**< protocol (tcp, udp, etc) */ + uint16_t ip_csum; /**< checksum */ + union { + struct { + struct in_addr ip_src;/**< source address */ + struct in_addr ip_dst;/**< destination address */ + } ip4_un1; + uint16_t ip_addrs[4]; + } ip4_hdrun1; +} __attribute__((__packed__)) IPV4Hdr; + + +#define s_ip_src ip4_hdrun1.ip4_un1.ip_src +#define s_ip_dst ip4_hdrun1.ip4_un1.ip_dst +#define s_ip_addrs ip4_hdrun1.ip_addrs + +#define IPV4_GET_RAW_VER(ip4h) (((ip4h)->ip_verhl & 0xf0) >> 4) +#define IPV4_GET_RAW_HLEN(ip4h) ((ip4h)->ip_verhl & 0x0f) +#define IPV4_GET_RAW_IPTOS(ip4h) ((ip4h)->ip_tos) +#define IPV4_GET_RAW_IPLEN(ip4h) ((ip4h)->ip_len) +#define IPV4_GET_RAW_IPID(ip4h) ((ip4h)->ip_id) +#define IPV4_GET_RAW_IPOFFSET(ip4h) ((ip4h)->ip_off) +#define IPV4_GET_RAW_IPTTL(ip4h) ((ip4h)->ip_ttl) +#define IPV4_GET_RAW_IPPROTO(ip4h) ((ip4h)->ip_proto) +#define IPV4_GET_RAW_IPSRC(ip4h) ((ip4h)->s_ip_src) +#define IPV4_GET_RAW_IPDST(ip4h) ((ip4h)->s_ip_dst) + +/** return the raw (directly from the header) src ip as uint32_t */ +#define IPV4_GET_RAW_IPSRC_U32(ip4h) (uint32_t)((ip4h)->s_ip_src.s_addr) +/** return the raw (directly from the header) dst ip as uint32_t */ +#define IPV4_GET_RAW_IPDST_U32(ip4h) (uint32_t)((ip4h)->s_ip_dst.s_addr) + +/* we need to change them as well as get them */ +#define IPV4_SET_RAW_VER(ip4h, value) ((ip4h)->ip_verhl = (((ip4h)->ip_verhl & 0x0f) | (value << 4))) +#define IPV4_SET_RAW_HLEN(ip4h, value) ((ip4h)->ip_verhl = (((ip4h)->ip_verhl & 0xf0) | (value & 0x0f))) +#define IPV4_SET_RAW_IPTOS(ip4h, value) ((ip4h)->ip_tos = value) +#define IPV4_SET_RAW_IPLEN(ip4h, value) ((ip4h)->ip_len = value) +#define IPV4_SET_RAW_IPPROTO(ip4h, value) ((ip4h)->ip_proto = value) + +/* ONLY call these functions after making sure that: + * 1. p->ip4h is set + * 2. p->ip4h is valid (len is correct) + */ +#define IPV4_GET_VER(p) \ + IPV4_GET_RAW_VER((p)->ip4h) +#define IPV4_GET_HLEN(p) \ + (IPV4_GET_RAW_HLEN((p)->ip4h) << 2) +#define IPV4_GET_IPTOS(p) \ + IPV4_GET_RAW_IPTOS((p)->ip4h) +#define IPV4_GET_IPLEN(p) \ + (ntohs(IPV4_GET_RAW_IPLEN((p)->ip4h))) +#define IPV4_GET_IPID(p) \ + (ntohs(IPV4_GET_RAW_IPID((p)->ip4h))) +/* _IPV4_GET_IPOFFSET: get the content of the offset header field in host order */ +#define _IPV4_GET_IPOFFSET(p) \ + (ntohs(IPV4_GET_RAW_IPOFFSET((p)->ip4h))) +/* IPV4_GET_IPOFFSET: get the final offset */ +#define IPV4_GET_IPOFFSET(p) \ + (_IPV4_GET_IPOFFSET(p) & 0x1fff) +/* IPV4_GET_RF: get the RF flag. Use _IPV4_GET_IPOFFSET to save a ntohs call. */ +#define IPV4_GET_RF(p) \ + (uint8_t)((_IPV4_GET_IPOFFSET((p)) & 0x8000) >> 15) +/* IPV4_GET_DF: get the DF flag. Use _IPV4_GET_IPOFFSET to save a ntohs call. */ +#define IPV4_GET_DF(p) \ + (uint8_t)((_IPV4_GET_IPOFFSET((p)) & 0x4000) >> 14) +/* IPV4_GET_MF: get the MF flag. Use _IPV4_GET_IPOFFSET to save a ntohs call. */ +#define IPV4_GET_MF(p) \ + (uint8_t)((_IPV4_GET_IPOFFSET((p)) & 0x2000) >> 13) +#define IPV4_GET_IPTTL(p) \ + IPV4_GET_RAW_IPTTL(p->ip4h) +#define IPV4_GET_IPPROTO(p) \ + IPV4_GET_RAW_IPPROTO((p)->ip4h) + +#define CLEAR_IPV4_PACKET(p) do { \ + (p)->ip4h = NULL; \ + (p)->level3_comp_csum = -1; \ + (p)->ip4vars.ip_src_u32 = 0; \ + (p)->ip4vars.ip_dst_u32 = 0; \ + (p)->ip4vars.ip_opt_cnt = 0; \ + (p)->ip4vars.o_rr = NULL; \ + (p)->ip4vars.o_qs = NULL; \ + (p)->ip4vars.o_ts = NULL; \ + (p)->ip4vars.o_sec = NULL; \ + (p)->ip4vars.o_lsrr = NULL; \ + (p)->ip4vars.o_cipso = NULL; \ + (p)->ip4vars.o_sid = NULL; \ + (p)->ip4vars.o_ssrr = NULL; \ + (p)->ip4vars.o_rtralt = NULL; \ +} while (0) + +/* helper structure with parsed ipv4 info */ +typedef struct IPV4Vars_ +{ + int32_t comp_csum; /* checksum computed over the ipv4 packet */ + uint32_t ip_src_u32; /* source IP */ + uint32_t ip_dst_u32; /* dest IP */ + + IPV4Opt ip_opts[IPV4_OPTMAX]; + uint8_t ip_opt_cnt; + + /* These are here for direct access and dup tracking */ + IPV4Opt *o_rr; + IPV4Opt *o_qs; + IPV4Opt *o_ts; + IPV4Opt *o_sec; + IPV4Opt *o_lsrr; + IPV4Opt *o_cipso; + IPV4Opt *o_sid; + IPV4Opt *o_ssrr; + IPV4Opt *o_rtralt; +} IPV4Vars; + + +void DecodeIPV4RegisterTests(void); + +/** ----- Inline functions ----- */ +static inline uint16_t IPV4CalculateChecksum(uint16_t *, uint16_t); +/** + * \brief Calculates the checksum for the IP packet + * + * \param pkt Pointer to the start of the IP packet + * \param hlen Length of the IP header + * + * \retval csum Checksum for the IP packet + */ +static inline uint16_t IPV4CalculateChecksum(uint16_t *pkt, uint16_t hlen) +{ + uint32_t csum = pkt[0]; + + csum += pkt[1] + pkt[2] + pkt[3] + pkt[4] + pkt[6] + pkt[7] + pkt[8] + + pkt[9]; + + hlen -= 20; + pkt += 10; + + if (hlen == 0) { + ; + } else if (hlen == 4) { + csum += pkt[0] + pkt[1]; + } else if (hlen == 8) { + csum += pkt[0] + pkt[1] + pkt[2] + pkt[3]; + } else if (hlen == 12) { + csum += pkt[0] + pkt[1] + pkt[2] + pkt[3] + pkt[4] + pkt[5]; + } else if (hlen == 16) { + csum += pkt[0] + pkt[1] + pkt[2] + pkt[3] + pkt[4] + pkt[5] + pkt[6] + + pkt[7]; + } else if (hlen == 20) { + csum += pkt[0] + pkt[1] + pkt[2] + pkt[3] + pkt[4] + pkt[5] + pkt[6] + + pkt[7] + pkt[8] + pkt[9]; + } else if (hlen == 24) { + 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]; + } else if (hlen == 28) { + 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]; + } else if (hlen == 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]; + } else if (hlen == 36) { + 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] + pkt[16] + pkt[17]; + } else if (hlen == 40) { + 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] + pkt[16] + pkt[17] + pkt[18] + pkt[19]; + } + + csum = (csum >> 16) + (csum & 0x0000FFFF); + csum += (csum >> 16); + + return (uint16_t) ~csum; +} + +#endif /* __DECODE_IPV4_H__ */ + |