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      1 /* @(#) $Header: /tcpdump/master/tcpdump/dccp.h,v 1.1.2.4 2006/05/12 01:46:17 guy Exp $ (LBL) */
      2 /*
      3  * Copyright (C) Arnaldo Carvalho de Melo 2004
      4  * Copyright (C) Ian McDonald 2005 <iam4 (at) cs.waikato.ac.nz>
      5  * Copyright (C) Yoshifumi Nishida 2005
      6  *
      7  * This software may be distributed either under the terms of the
      8  * BSD-style license that accompanies tcpdump or the GNU GPL version 2
      9  */
     10 
     11 #ifndef __DCCP_HDR__
     12 #define __DCCP_HDR__
     13 
     14 /**
     15  * struct dccp_hdr - generic part of DCCP packet header
     16  *
     17  * @dccph_sport - Relevant port on the endpoint that sent this packet
     18  * @dccph_dport - Relevant port on the other endpoint
     19  * @dccph_doff - Data Offset from the start of the DCCP header, in 32-bit words
     20  * @dccph_ccval - Used by the HC-Sender CCID
     21  * @dccph_cscov - Parts of the packet that are covered by the Checksum field
     22  * @dccph_checksum - Internet checksum, depends on dccph_cscov
     23  * @dccph_x - 0 = 24 bit sequence number, 1 = 48
     24  * @dccph_type - packet type, see DCCP_PKT_ prefixed macros
     25  * @dccph_seq - sequence number high or low order 24 bits, depends on dccph_x
     26  */
     27 struct dccp_hdr {
     28 	u_int16_t	dccph_sport,
     29 			dccph_dport;
     30 	u_int8_t	dccph_doff;
     31 	u_int8_t	dccph_ccval_cscov;
     32 	u_int16_t	dccph_checksum;
     33 	union {
     34 	u_int8_t	dccph_xtr;
     35 	u_int32_t	dccph_seq;
     36 	}		dccph_xtrs;
     37 };
     38 
     39 #define DCCPH_CCVAL(dh)	(((dh)->dccph_ccval_cscov) & 0x0F)
     40 #define DCCPH_CSCOV(dh)	(((dh)->dccph_ccval_cscov >> 4) & 0x0F)
     41 
     42 #define DCCPH_X(dh)	((dh)->dccph_xtrs.dccph_xtr & 1)
     43 #define DCCPH_TYPE(dh)	(((dh)->dccph_xtrs.dccph_xtr >> 1) & 0xF)
     44 #define DCCPH_SEQ(dh)   (((dh)->dccph_xtrs.dccph_seq) >> 8)
     45 
     46 /**
     47  * struct dccp_hdr_ext - the low bits of a 48 bit seq packet
     48  *
     49  * @dccph_seq_low - low 24 bits of a 48 bit seq packet
     50  */
     51 struct dccp_hdr_ext {
     52 	u_int32_t	dccph_seq_low;
     53 };
     54 
     55 /**
     56  * struct dccp_hdr_request - Conection initiation request header
     57  *
     58  * @dccph_req_service - Service to which the client app wants to connect
     59  */
     60 struct dccp_hdr_request {
     61 	u_int32_t	dccph_req_service;
     62 };
     63 
     64 /**
     65  * struct dccp_hdr_ack_bits - acknowledgment bits common to most packets
     66  *
     67  * @dccph_resp_ack_nr_high - 48 bit ack number high order bits, contains GSR
     68  * @dccph_resp_ack_nr_low - 48 bit ack number low order bits, contains GSR
     69  */
     70 struct dccp_hdr_ack_bits {
     71 	u_int32_t	dccph_ra;
     72 	u_int32_t	dccph_ack_nr_low;
     73 };
     74 
     75 #define DCCPH_ACK(dh_ack)   ((dh_ack)->dccph_ra >> 8)
     76 
     77 /**
     78  * struct dccp_hdr_response - Conection initiation response header
     79  *
     80  * @dccph_resp_ack_nr_high - 48 bit ack number high order bits, contains GSR
     81  * @dccph_resp_ack_nr_low - 48 bit ack number low order bits, contains GSR
     82  * @dccph_resp_service - Echoes the Service Code on a received DCCP-Request
     83  */
     84 struct dccp_hdr_response {
     85 	struct dccp_hdr_ack_bits	dccph_resp_ack;
     86 	u_int32_t			dccph_resp_service;
     87 };
     88 
     89 #if 0
     90 static inline struct dccp_hdr_data *dccp_hdr_data(struct dccp_hdr *hdrg)
     91 {
     92 	const int ext = DCCPH_X(hdrg) ? sizeof(struct dccp_hdr_ext) : 0;
     93 
     94 	return (struct dccp_hdr_data *)(((u_char *)hdrg) + sizeof(hdrg) + ext);
     95 }
     96 #endif
     97 
     98 /**
     99  * struct dccp_hdr_reset - Unconditionally shut down a connection
    100  *
    101  * @dccph_reset_service - Echoes the Service Code on a received DCCP-Request
    102  */
    103 struct dccp_hdr_reset {
    104 	struct dccp_hdr_ack_bits	dccph_reset_ack;
    105 	u_int8_t			dccph_reset_code,
    106 					dccph_reset_data[3];
    107 };
    108 
    109 enum dccp_pkt_type {
    110 	DCCP_PKT_REQUEST = 0,
    111 	DCCP_PKT_RESPONSE,
    112 	DCCP_PKT_DATA,
    113 	DCCP_PKT_ACK,
    114 	DCCP_PKT_DATAACK,
    115 	DCCP_PKT_CLOSEREQ,
    116 	DCCP_PKT_CLOSE,
    117 	DCCP_PKT_RESET,
    118 	DCCP_PKT_SYNC,
    119 	DCCP_PKT_SYNCACK,
    120 	DCCP_PKT_INVALID
    121 };
    122 
    123 enum dccp_reset_codes {
    124 	DCCP_RESET_CODE_UNSPECIFIED = 0,
    125 	DCCP_RESET_CODE_CLOSED,
    126 	DCCP_RESET_CODE_ABORTED,
    127 	DCCP_RESET_CODE_NO_CONNECTION,
    128 	DCCP_RESET_CODE_PACKET_ERROR,
    129 	DCCP_RESET_CODE_OPTION_ERROR,
    130 	DCCP_RESET_CODE_MANDATORY_ERROR,
    131 	DCCP_RESET_CODE_CONNECTION_REFUSED,
    132 	DCCP_RESET_CODE_BAD_SERVICE_CODE,
    133 	DCCP_RESET_CODE_TOO_BUSY,
    134 	DCCP_RESET_CODE_BAD_INIT_COOKIE,
    135 	DCCP_RESET_CODE_AGGRESSION_PENALTY,
    136 	__DCCP_RESET_CODE_LAST
    137 };
    138 
    139 #endif /* __DCCP_HDR__ */
    140