/* SCTP kernel reference Implementation * (C) Copyright IBM Corp. 2001, 2004 * Copyright (c) 1999-2000 Cisco, Inc. * Copyright (c) 1999-2001 Motorola, Inc. * Copyright (c) 2001 Intel Corp. * Copyright (c) 2001 Nokia, Inc. * Copyright (c) 2001 La Monte H.P. Yarroll * * This file is part of the SCTP kernel reference Implementation * * Various protocol defined structures. * * The SCTP reference implementation is free software; * you can redistribute it and/or modify it under the terms of * the GNU General Public License as published by * the Free Software Foundation; either version 2, or (at your option) * any later version. * * The SCTP reference implementation 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 * along with GNU CC; see the file COPYING. If not, write to * the Free Software Foundation, 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. * * Please send any bug reports or fixes you make to the * email address(es): * lksctp developers <lksctp-developerst@lists.sourceforge.net> * * Or submit a bug report through the following website: * http://www.sf.net/projects/lksctp * * Written or modified by: * La Monte H.P. Yarroll <piggy@acm.org> * Karl Knutson <karl@athena.chicago.il.us> * Jon Grimm <jgrimm@us.ibm.com> * Xingang Guo <xingang.guo@intel.com> * randall@sctp.chicago.il.us * kmorneau@cisco.com * qxie1@email.mot.com * Sridhar Samudrala <sri@us.ibm.com> * Kevin Gao <kevin.gao@intel.com> * * Any bugs reported given to us we will try to fix... any fixes shared will * be incorporated into the next SCTP release. */ #ifndef __LINUX_SCTP_H__ #define __LINUX_SCTP_H__ #include <linux/in.h> /* We need in_addr. */ #include <linux/in6.h> /* We need in6_addr. */ /* Section 3.1. SCTP Common Header Format */ typedef struct sctphdr { __be16 source; __be16 dest; __be32 vtag; __be32 checksum; } __attribute__((packed)) sctp_sctphdr_t; #ifdef __KERNEL__ #include <linux/skbuff.h> static inline struct sctphdr *sctp_hdr(const struct sk_buff *skb) { return (struct sctphdr *)skb_transport_header(skb); } #endif /* Section 3.2. Chunk Field Descriptions. */ typedef struct sctp_chunkhdr { __u8 type; __u8 flags; __be16 length; } __attribute__((packed)) sctp_chunkhdr_t; /* Section 3.2. Chunk Type Values. * [Chunk Type] identifies the type of information contained in the Chunk * Value field. It takes a value from 0 to 254. The value of 255 is * reserved for future use as an extension field. */ typedef enum { SCTP_CID_DATA = 0, SCTP_CID_INIT = 1, SCTP_CID_INIT_ACK = 2, SCTP_CID_SACK = 3, SCTP_CID_HEARTBEAT = 4, SCTP_CID_HEARTBEAT_ACK = 5, SCTP_CID_ABORT = 6, SCTP_CID_SHUTDOWN = 7, SCTP_CID_SHUTDOWN_ACK = 8, SCTP_CID_ERROR = 9, SCTP_CID_COOKIE_ECHO = 10, SCTP_CID_COOKIE_ACK = 11, SCTP_CID_ECN_ECNE = 12, SCTP_CID_ECN_CWR = 13, SCTP_CID_SHUTDOWN_COMPLETE = 14, /* AUTH Extension Section 4.1 */ SCTP_CID_AUTH = 0x0F, /* PR-SCTP Sec 3.2 */ SCTP_CID_FWD_TSN = 0xC0, /* Use hex, as defined in ADDIP sec. 3.1 */ SCTP_CID_ASCONF = 0xC1, SCTP_CID_ASCONF_ACK = 0x80, } sctp_cid_t; /* enum */ /* Section 3.2 * Chunk Types are encoded such that the highest-order two bits specify * the action that must be taken if the processing endpoint does not * recognize the Chunk Type. */ typedef enum { SCTP_CID_ACTION_DISCARD = 0x00, SCTP_CID_ACTION_DISCARD_ERR = 0x40, SCTP_CID_ACTION_SKIP = 0x80, SCTP_CID_ACTION_SKIP_ERR = 0xc0, } sctp_cid_action_t; enum { SCTP_CID_ACTION_MASK = 0xc0, }; /* This flag is used in Chunk Flags for ABORT and SHUTDOWN COMPLETE. * * 3.3.7 Abort Association (ABORT) (6): * The T bit is set to 0 if the sender had a TCB that it destroyed. * If the sender did not have a TCB it should set this bit to 1. */ enum { SCTP_CHUNK_FLAG_T = 0x01 }; /* * Set the T bit * * 0 1 2 3 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Type = 14 |Reserved |T| Length = 4 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * * Chunk Flags: 8 bits * * Reserved: 7 bits * Set to 0 on transmit and ignored on receipt. * * T bit: 1 bit * The T bit is set to 0 if the sender had a TCB that it destroyed. If * the sender did NOT have a TCB it should set this bit to 1. * * Note: Special rules apply to this chunk for verification, please * see Section 8.5.1 for details. */ #define sctp_test_T_bit(c) ((c)->chunk_hdr->flags & SCTP_CHUNK_FLAG_T) /* RFC 2960 * Section 3.2.1 Optional/Variable-length Parmaeter Format. */ typedef struct sctp_paramhdr { __be16 type; __be16 length; } __attribute__((packed)) sctp_paramhdr_t; typedef enum { /* RFC 2960 Section 3.3.5 */ SCTP_PARAM_HEARTBEAT_INFO = __constant_htons(1), /* RFC 2960 Section 3.3.2.1 */ SCTP_PARAM_IPV4_ADDRESS = __constant_htons(5), SCTP_PARAM_IPV6_ADDRESS = __constant_htons(6), SCTP_PARAM_STATE_COOKIE = __constant_htons(7), SCTP_PARAM_UNRECOGNIZED_PARAMETERS = __constant_htons(8), SCTP_PARAM_COOKIE_PRESERVATIVE = __constant_htons(9), SCTP_PARAM_HOST_NAME_ADDRESS = __constant_htons(11), SCTP_PARAM_SUPPORTED_ADDRESS_TYPES = __constant_htons(12), SCTP_PARAM_ECN_CAPABLE = __constant_htons(0x8000), /* AUTH Extension Section 3 */ SCTP_PARAM_RANDOM = __constant_htons(0x8002), SCTP_PARAM_CHUNKS = __constant_htons(0x8003), SCTP_PARAM_HMAC_ALGO = __constant_htons(0x8004), /* Add-IP: Supported Extensions, Section 4.2 */ SCTP_PARAM_SUPPORTED_EXT = __constant_htons(0x8008), /* PR-SCTP Sec 3.1 */ SCTP_PARAM_FWD_TSN_SUPPORT = __constant_htons(0xc000), /* Add-IP Extension. Section 3.2 */ SCTP_PARAM_ADD_IP = __constant_htons(0xc001), SCTP_PARAM_DEL_IP = __constant_htons(0xc002), SCTP_PARAM_ERR_CAUSE = __constant_htons(0xc003), SCTP_PARAM_SET_PRIMARY = __constant_htons(0xc004), SCTP_PARAM_SUCCESS_REPORT = __constant_htons(0xc005), SCTP_PARAM_ADAPTATION_LAYER_IND = __constant_htons(0xc006), } sctp_param_t; /* enum */ /* RFC 2960 Section 3.2.1 * The Parameter Types are encoded such that the highest-order two bits * specify the action that must be taken if the processing endpoint does * not recognize the Parameter Type. * */ typedef enum { SCTP_PARAM_ACTION_DISCARD = __constant_htons(0x0000), SCTP_PARAM_ACTION_DISCARD_ERR = __constant_htons(0x4000), SCTP_PARAM_ACTION_SKIP = __constant_htons(0x8000), SCTP_PARAM_ACTION_SKIP_ERR = __constant_htons(0xc000), } sctp_param_action_t; enum { SCTP_PARAM_ACTION_MASK = __constant_htons(0xc000), }; /* RFC 2960 Section 3.3.1 Payload Data (DATA) (0) */ typedef struct sctp_datahdr { __be32 tsn; __be16 stream; __be16 ssn; __be32 ppid; __u8 payload[0]; } __attribute__((packed)) sctp_datahdr_t; typedef struct sctp_data_chunk { sctp_chunkhdr_t chunk_hdr; sctp_datahdr_t data_hdr; } __attribute__((packed)) sctp_data_chunk_t; /* DATA Chuck Specific Flags */ enum { SCTP_DATA_MIDDLE_FRAG = 0x00, SCTP_DATA_LAST_FRAG = 0x01, SCTP_DATA_FIRST_FRAG = 0x02, SCTP_DATA_NOT_FRAG = 0x03, SCTP_DATA_UNORDERED = 0x04, }; enum { SCTP_DATA_FRAG_MASK = 0x03, }; /* RFC 2960 Section 3.3.2 Initiation (INIT) (1) * * This chunk is used to initiate a SCTP association between two * endpoints. */ typedef struct sctp_inithdr { __be32 init_tag; __be32 a_rwnd; __be16 num_outbound_streams; __be16 num_inbound_streams; __be32 initial_tsn; __u8 params[0]; } __attribute__((packed)) sctp_inithdr_t; typedef struct sctp_init_chunk { sctp_chunkhdr_t chunk_hdr; sctp_inithdr_t init_hdr; } __attribute__((packed)) sctp_init_chunk_t; /* Section 3.3.2.1. IPv4 Address Parameter (5) */ typedef struct sctp_ipv4addr_param { sctp_paramhdr_t param_hdr; struct in_addr addr; } __attribute__((packed)) sctp_ipv4addr_param_t; /* Section 3.3.2.1. IPv6 Address Parameter (6) */ typedef struct sctp_ipv6addr_param { sctp_paramhdr_t param_hdr; struct in6_addr addr; } __attribute__((packed)) sctp_ipv6addr_param_t; /* Section 3.3.2.1 Cookie Preservative (9) */ typedef struct sctp_cookie_preserve_param { sctp_paramhdr_t param_hdr; __be32 lifespan_increment; } __attribute__((packed)) sctp_cookie_preserve_param_t; /* Section 3.3.2.1 Host Name Address (11) */ typedef struct sctp_hostname_param { sctp_paramhdr_t param_hdr; uint8_t hostname[0]; } __attribute__((packed)) sctp_hostname_param_t; /* Section 3.3.2.1 Supported Address Types (12) */ typedef struct sctp_supported_addrs_param { sctp_paramhdr_t param_hdr; __be16 types[0]; } __attribute__((packed)) sctp_supported_addrs_param_t; /* Appendix A. ECN Capable (32768) */ typedef struct sctp_ecn_capable_param { sctp_paramhdr_t param_hdr; } __attribute__((packed)) sctp_ecn_capable_param_t; /* ADDIP Section 3.2.6 Adaptation Layer Indication */ typedef struct sctp_adaptation_ind_param { struct sctp_paramhdr param_hdr; __be32 adaptation_ind; } __attribute__((packed)) sctp_adaptation_ind_param_t; /* ADDIP Section 4.2.7 Supported Extensions Parameter */ typedef struct sctp_supported_ext_param { struct sctp_paramhdr param_hdr; __u8 chunks[0]; } __attribute__((packed)) sctp_supported_ext_param_t; /* AUTH Section 3.1 Random */ typedef struct sctp_random_param { sctp_paramhdr_t param_hdr; __u8 random_val[0]; } __attribute__((packed)) sctp_random_param_t; /* AUTH Section 3.2 Chunk List */ typedef struct sctp_chunks_param { sctp_paramhdr_t param_hdr; __u8 chunks[0]; } __attribute__((packed)) sctp_chunks_param_t; /* AUTH Section 3.3 HMAC Algorithm */ typedef struct sctp_hmac_algo_param { sctp_paramhdr_t param_hdr; __be16 hmac_ids[0]; } __attribute__((packed)) sctp_hmac_algo_param_t; /* RFC 2960. Section 3.3.3 Initiation Acknowledgement (INIT ACK) (2): * The INIT ACK chunk is used to acknowledge the initiation of an SCTP * association. */ typedef sctp_init_chunk_t sctp_initack_chunk_t; /* Section 3.3.3.1 State Cookie (7) */ typedef struct sctp_cookie_param { sctp_paramhdr_t p; __u8 body[0]; } __attribute__((packed)) sctp_cookie_param_t; /* Section 3.3.3.1 Unrecognized Parameters (8) */ typedef struct sctp_unrecognized_param { sctp_paramhdr_t param_hdr; sctp_paramhdr_t unrecognized; } __attribute__((packed)) sctp_unrecognized_param_t; /* * 3.3.4 Selective Acknowledgement (SACK) (3): * * This chunk is sent to the peer endpoint to acknowledge received DATA * chunks and to inform the peer endpoint of gaps in the received * subsequences of DATA chunks as represented by their TSNs. */ typedef struct sctp_gap_ack_block { __be16 start; __be16 end; } __attribute__((packed)) sctp_gap_ack_block_t; typedef __be32 sctp_dup_tsn_t; typedef union { sctp_gap_ack_block_t gab; sctp_dup_tsn_t dup; } sctp_sack_variable_t; typedef struct sctp_sackhdr { __be32 cum_tsn_ack; __be32 a_rwnd; __be16 num_gap_ack_blocks; __be16 num_dup_tsns; sctp_sack_variable_t variable[0]; } __attribute__((packed)) sctp_sackhdr_t; typedef struct sctp_sack_chunk { sctp_chunkhdr_t chunk_hdr; sctp_sackhdr_t sack_hdr; } __attribute__((packed)) sctp_sack_chunk_t; /* RFC 2960. Section 3.3.5 Heartbeat Request (HEARTBEAT) (4): * * An endpoint should send this chunk to its peer endpoint to probe the * reachability of a particular destination transport address defined in * the present association. */ typedef struct sctp_heartbeathdr { sctp_paramhdr_t info; } __attribute__((packed)) sctp_heartbeathdr_t; typedef struct sctp_heartbeat_chunk { sctp_chunkhdr_t chunk_hdr; sctp_heartbeathdr_t hb_hdr; } __attribute__((packed)) sctp_heartbeat_chunk_t; /* For the abort and shutdown ACK we must carry the init tag in the * common header. Just the common header is all that is needed with a * chunk descriptor. */ typedef struct sctp_abort_chunk { sctp_chunkhdr_t uh; } __attribute__((packed)) sctp_abort_chunk_t; /* For the graceful shutdown we must carry the tag (in common header) * and the highest consecutive acking value. */ typedef struct sctp_shutdownhdr { __be32 cum_tsn_ack; } __attribute__((packed)) sctp_shutdownhdr_t; struct sctp_shutdown_chunk_t { sctp_chunkhdr_t chunk_hdr; sctp_shutdownhdr_t shutdown_hdr; } __attribute__ ((packed)); /* RFC 2960. Section 3.3.10 Operation Error (ERROR) (9) */ typedef struct sctp_errhdr { __be16 cause; __be16 length; __u8 variable[0]; } __attribute__((packed)) sctp_errhdr_t; typedef struct sctp_operr_chunk { sctp_chunkhdr_t chunk_hdr; sctp_errhdr_t err_hdr; } __attribute__((packed)) sctp_operr_chunk_t; /* RFC 2960 3.3.10 - Operation Error * * Cause Code: 16 bits (unsigned integer) * * Defines the type of error conditions being reported. * Cause Code * Value Cause Code * --------- ---------------- * 1 Invalid Stream Identifier * 2 Missing Mandatory Parameter * 3 Stale Cookie Error * 4 Out of Resource * 5 Unresolvable Address * 6 Unrecognized Chunk Type * 7 Invalid Mandatory Parameter * 8 Unrecognized Parameters * 9 No User Data * 10 Cookie Received While Shutting Down */ typedef enum { SCTP_ERROR_NO_ERROR = __constant_htons(0x00), SCTP_ERROR_INV_STRM = __constant_htons(0x01), SCTP_ERROR_MISS_PARAM = __constant_htons(0x02), SCTP_ERROR_STALE_COOKIE = __constant_htons(0x03), SCTP_ERROR_NO_RESOURCE = __constant_htons(0x04), SCTP_ERROR_DNS_FAILED = __constant_htons(0x05), SCTP_ERROR_UNKNOWN_CHUNK = __constant_htons(0x06), SCTP_ERROR_INV_PARAM = __constant_htons(0x07), SCTP_ERROR_UNKNOWN_PARAM = __constant_htons(0x08), SCTP_ERROR_NO_DATA = __constant_htons(0x09), SCTP_ERROR_COOKIE_IN_SHUTDOWN = __constant_htons(0x0a), /* SCTP Implementation Guide: * 11 Restart of an association with new addresses * 12 User Initiated Abort * 13 Protocol Violation */ SCTP_ERROR_RESTART = __constant_htons(0x0b), SCTP_ERROR_USER_ABORT = __constant_htons(0x0c), SCTP_ERROR_PROTO_VIOLATION = __constant_htons(0x0d), /* ADDIP Section 3.3 New Error Causes * * Four new Error Causes are added to the SCTP Operational Errors, * primarily for use in the ASCONF-ACK chunk. * * Value Cause Code * --------- ---------------- * 0x0100 Request to Delete Last Remaining IP Address. * 0x0101 Operation Refused Due to Resource Shortage. * 0x0102 Request to Delete Source IP Address. * 0x0103 Association Aborted due to illegal ASCONF-ACK * 0x0104 Request refused - no authorization. */ SCTP_ERROR_DEL_LAST_IP = __constant_htons(0x0100), SCTP_ERROR_RSRC_LOW = __constant_htons(0x0101), SCTP_ERROR_DEL_SRC_IP = __constant_htons(0x0102), SCTP_ERROR_ASCONF_ACK = __constant_htons(0x0103), SCTP_ERROR_REQ_REFUSED = __constant_htons(0x0104), /* AUTH Section 4. New Error Cause * * This section defines a new error cause that will be sent if an AUTH * chunk is received with an unsupported HMAC identifier. * illustrates the new error cause. * * Cause Code Error Cause Name * -------------------------------------------------------------- * 0x0105 Unsupported HMAC Identifier */ SCTP_ERROR_UNSUP_HMAC = __constant_htons(0x0105) } sctp_error_t; /* RFC 2960. Appendix A. Explicit Congestion Notification. * Explicit Congestion Notification Echo (ECNE) (12) */ typedef struct sctp_ecnehdr { __be32 lowest_tsn; } sctp_ecnehdr_t; typedef struct sctp_ecne_chunk { sctp_chunkhdr_t chunk_hdr; sctp_ecnehdr_t ence_hdr; } __attribute__((packed)) sctp_ecne_chunk_t; /* RFC 2960. Appendix A. Explicit Congestion Notification. * Congestion Window Reduced (CWR) (13) */ typedef struct sctp_cwrhdr { __be32 lowest_tsn; } sctp_cwrhdr_t; typedef struct sctp_cwr_chunk { sctp_chunkhdr_t chunk_hdr; sctp_cwrhdr_t cwr_hdr; } __attribute__((packed)) sctp_cwr_chunk_t; /* PR-SCTP * 3.2 Forward Cumulative TSN Chunk Definition (FORWARD TSN) * * Forward Cumulative TSN chunk has the following format: * * 0 1 2 3 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Type = 192 | Flags = 0x00 | Length = Variable | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | New Cumulative TSN | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Stream-1 | Stream Sequence-1 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * \ / * / \ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Stream-N | Stream Sequence-N | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * * Chunk Flags: * * Set to all zeros on transmit and ignored on receipt. * * New Cumulative TSN: 32 bit u_int * * This indicates the new cumulative TSN to the data receiver. Upon * the reception of this value, the data receiver MUST consider * any missing TSNs earlier than or equal to this value as received * and stop reporting them as gaps in any subsequent SACKs. * * Stream-N: 16 bit u_int * * This field holds a stream number that was skipped by this * FWD-TSN. * * Stream Sequence-N: 16 bit u_int * This field holds the sequence number associated with the stream * that was skipped. The stream sequence field holds the largest stream * sequence number in this stream being skipped. The receiver of * the FWD-TSN's can use the Stream-N and Stream Sequence-N fields * to enable delivery of any stranded TSN's that remain on the stream * re-ordering queues. This field MUST NOT report TSN's corresponding * to DATA chunk that are marked as unordered. For ordered DATA * chunks this field MUST be filled in. */ struct sctp_fwdtsn_skip { __be16 stream; __be16 ssn; } __attribute__((packed)); struct sctp_fwdtsn_hdr { __be32 new_cum_tsn; struct sctp_fwdtsn_skip skip[0]; } __attribute((packed)); struct sctp_fwdtsn_chunk { struct sctp_chunkhdr chunk_hdr; struct sctp_fwdtsn_hdr fwdtsn_hdr; } __attribute((packed)); /* ADDIP * Section 3.1.1 Address Configuration Change Chunk (ASCONF) * * Serial Number: 32 bits (unsigned integer) * This value represents a Serial Number for the ASCONF Chunk. The * valid range of Serial Number is from 0 to 2^32-1. * Serial Numbers wrap back to 0 after reaching 2^32 -1. * * Address Parameter: 8 or 20 bytes (depending on type) * The address is an address of the sender of the ASCONF chunk, * the address MUST be considered part of the association by the * peer endpoint. This field may be used by the receiver of the * ASCONF to help in finding the association. This parameter MUST * be present in every ASCONF message i.e. it is a mandatory TLV * parameter. * * ASCONF Parameter: TLV format * Each Address configuration change is represented by a TLV * parameter as defined in Section 3.2. One or more requests may * be present in an ASCONF Chunk. * * Section 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK) * * Serial Number: 32 bits (unsigned integer) * This value represents the Serial Number for the received ASCONF * Chunk that is acknowledged by this chunk. This value is copied * from the received ASCONF Chunk. * * ASCONF Parameter Response: TLV format * The ASCONF Parameter Response is used in the ASCONF-ACK to * report status of ASCONF processing. */ typedef struct sctp_addip_param { sctp_paramhdr_t param_hdr; __be32 crr_id; } __attribute__((packed)) sctp_addip_param_t; typedef struct sctp_addiphdr { __be32 serial; __u8 params[0]; } __attribute__((packed)) sctp_addiphdr_t; typedef struct sctp_addip_chunk { sctp_chunkhdr_t chunk_hdr; sctp_addiphdr_t addip_hdr; } __attribute__((packed)) sctp_addip_chunk_t; /* AUTH * Section 4.1 Authentication Chunk (AUTH) * * This chunk is used to hold the result of the HMAC calculation. * * 0 1 2 3 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Type = 0x0F | Flags=0 | Length | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Shared Key Identifier | HMAC Identifier | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | | * \ HMAC / * / \ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * * Type: 1 byte (unsigned integer) * This value MUST be set to 0x0F for all AUTH-chunks. * * Flags: 1 byte (unsigned integer) * Set to zero on transmit and ignored on receipt. * * Length: 2 bytes (unsigned integer) * This value holds the length of the HMAC in bytes plus 8. * * Shared Key Identifier: 2 bytes (unsigned integer) * This value describes which endpoint pair shared key is used. * * HMAC Identifier: 2 bytes (unsigned integer) * This value describes which message digest is being used. Table 2 * shows the currently defined values. * * The following Table 2 shows the currently defined values for HMAC * identifiers. * * +-----------------+--------------------------+ * | HMAC Identifier | Message Digest Algorithm | * +-----------------+--------------------------+ * | 0 | Reserved | * | 1 | SHA-1 defined in [8] | * | 2 | Reserved | * | 3 | SHA-256 defined in [8] | * +-----------------+--------------------------+ * * * HMAC: n bytes (unsigned integer) This hold the result of the HMAC * calculation. */ typedef struct sctp_authhdr { __be16 shkey_id; __be16 hmac_id; __u8 hmac[0]; } __attribute__((packed)) sctp_authhdr_t; typedef struct sctp_auth_chunk { sctp_chunkhdr_t chunk_hdr; sctp_authhdr_t auth_hdr; } __attribute__((packed)) sctp_auth_chunk_t; #endif /* __LINUX_SCTP_H__ */