include/uapi/linux/dccp.h

   1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
   2 #ifndef _UAPI_LINUX_DCCP_H
   3 #define _UAPI_LINUX_DCCP_H
   4
   5 #include <linux/types.h>
   6 #include <asm/byteorder.h>
   7
   8 /**
   9  * struct dccp_hdr - generic part of DCCP packet header
  10  *
  11  * @dccph_sport - Relevant port on the endpoint that sent this packet
  12  * @dccph_dport - Relevant port on the other endpoint
  13  * @dccph_doff - Data Offset from the start of the DCCP header, in 32-bit words
  14  * @dccph_ccval - Used by the HC-Sender CCID
  15  * @dccph_cscov - Parts of the packet that are covered by the Checksum field
  16  * @dccph_checksum - Internet checksum, depends on dccph_cscov
  17  * @dccph_x - 0 = 24 bit sequence number, 1 = 48
  18  * @dccph_type - packet type, see DCCP_PKT_ prefixed macros
  19  * @dccph_seq - sequence number high or low order 24 bits, depends on dccph_x
  20  */
  21 struct dccp_hdr {
  22         __be16  dccph_sport,
  23                 dccph_dport;
  24         __u8    dccph_doff;
  25 #if defined(__LITTLE_ENDIAN_BITFIELD)
  26         __u8    dccph_cscov:4,
  27                 dccph_ccval:4;
  28 #elif defined(__BIG_ENDIAN_BITFIELD)
  29         __u8    dccph_ccval:4,
  30                 dccph_cscov:4;
  31 #else
  32 #error  "Adjust your <asm/byteorder.h> defines"
  33 #endif
  34         __sum16 dccph_checksum;
  35 #if defined(__LITTLE_ENDIAN_BITFIELD)
  36         __u8    dccph_x:1,
  37                 dccph_type:4,
  38                 dccph_reserved:3;
  39 #elif defined(__BIG_ENDIAN_BITFIELD)
  40         __u8    dccph_reserved:3,
  41                 dccph_type:4,
  42                 dccph_x:1;
  43 #else
  44 #error  "Adjust your <asm/byteorder.h> defines"
  45 #endif
  46         __u8    dccph_seq2;
  47         __be16  dccph_seq;
  48 };
  49
  50 /**
  51  * struct dccp_hdr_ext - the low bits of a 48 bit seq packet
  52  *
  53  * @dccph_seq_low - low 24 bits of a 48 bit seq packet
  54  */
  55 struct dccp_hdr_ext {
  56         __be32  dccph_seq_low;
  57 };
  58
  59 /**
  60  * struct dccp_hdr_request - Connection initiation request header
  61  *
  62  * @dccph_req_service - Service to which the client app wants to connect
  63  */
  64 struct dccp_hdr_request {
  65         __be32  dccph_req_service;
  66 };
  67 /**
  68  * struct dccp_hdr_ack_bits - acknowledgment bits common to most packets
  69  *
  70  * @dccph_resp_ack_nr_high - 48 bit ack number high order bits, contains GSR
  71  * @dccph_resp_ack_nr_low - 48 bit ack number low order bits, contains GSR
  72  */
  73 struct dccp_hdr_ack_bits {
  74         __be16  dccph_reserved1;
  75         __be16  dccph_ack_nr_high;
  76         __be32  dccph_ack_nr_low;
  77 };
  78 /**
  79  * struct dccp_hdr_response - Connection initiation response header
  80  *
  81  * @dccph_resp_ack - 48 bit Acknowledgment Number Subheader (5.3)
  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         __be32                          dccph_resp_service;
  87 };
  88
  89 /**
  90  * struct dccp_hdr_reset - Unconditionally shut down a connection
  91  *
  92  * @dccph_reset_ack - 48 bit Acknowledgment Number Subheader (5.6)
  93  * @dccph_reset_code - one of %dccp_reset_codes
  94  * @dccph_reset_data - the Data 1 ... Data 3 fields from 5.6
  95  */
  96 struct dccp_hdr_reset {
  97         struct dccp_hdr_ack_bits        dccph_reset_ack;
  98         __u8                            dccph_reset_code,
  99                                         dccph_reset_data[3];
 100 };
 101
 102 enum dccp_pkt_type {
 103         DCCP_PKT_REQUEST = 0,
 104         DCCP_PKT_RESPONSE,
 105         DCCP_PKT_DATA,
 106         DCCP_PKT_ACK,
 107         DCCP_PKT_DATAACK,
 108         DCCP_PKT_CLOSEREQ,
 109         DCCP_PKT_CLOSE,
 110         DCCP_PKT_RESET,
 111         DCCP_PKT_SYNC,
 112         DCCP_PKT_SYNCACK,
 113         DCCP_PKT_INVALID,
 114 };
 115
 116 #define DCCP_NR_PKT_TYPES DCCP_PKT_INVALID
 117
 118 static inline unsigned int dccp_packet_hdr_len(const __u8 type)
 119 {
 120         if (type == DCCP_PKT_DATA)
 121                 return 0;
 122         if (type == DCCP_PKT_DATAACK    ||
 123             type == DCCP_PKT_ACK        ||
 124             type == DCCP_PKT_SYNC       ||
 125             type == DCCP_PKT_SYNCACK    ||
 126             type == DCCP_PKT_CLOSE      ||
 127             type == DCCP_PKT_CLOSEREQ)
 128                 return sizeof(struct dccp_hdr_ack_bits);
 129         if (type == DCCP_PKT_REQUEST)
 130                 return sizeof(struct dccp_hdr_request);
 131         if (type == DCCP_PKT_RESPONSE)
 132                 return sizeof(struct dccp_hdr_response);
 133         return sizeof(struct dccp_hdr_reset);
 134 }
 135 enum dccp_reset_codes {
 136         DCCP_RESET_CODE_UNSPECIFIED = 0,
 137         DCCP_RESET_CODE_CLOSED,
 138         DCCP_RESET_CODE_ABORTED,
 139         DCCP_RESET_CODE_NO_CONNECTION,
 140         DCCP_RESET_CODE_PACKET_ERROR,
 141         DCCP_RESET_CODE_OPTION_ERROR,
 142         DCCP_RESET_CODE_MANDATORY_ERROR,
 143         DCCP_RESET_CODE_CONNECTION_REFUSED,
 144         DCCP_RESET_CODE_BAD_SERVICE_CODE,
 145         DCCP_RESET_CODE_TOO_BUSY,
 146         DCCP_RESET_CODE_BAD_INIT_COOKIE,
 147         DCCP_RESET_CODE_AGGRESSION_PENALTY,
 148
 149         DCCP_MAX_RESET_CODES            /* Leave at the end!  */
 150 };
 151
 152 /* DCCP options */
 153 enum {
 154         DCCPO_PADDING = 0,
 155         DCCPO_MANDATORY = 1,
 156         DCCPO_MIN_RESERVED = 3,
 157         DCCPO_MAX_RESERVED = 31,
 158         DCCPO_CHANGE_L = 32,
 159         DCCPO_CONFIRM_L = 33,
 160         DCCPO_CHANGE_R = 34,
 161         DCCPO_CONFIRM_R = 35,
 162         DCCPO_NDP_COUNT = 37,
 163         DCCPO_ACK_VECTOR_0 = 38,
 164         DCCPO_ACK_VECTOR_1 = 39,
 165         DCCPO_TIMESTAMP = 41,
 166         DCCPO_TIMESTAMP_ECHO = 42,
 167         DCCPO_ELAPSED_TIME = 43,
 168         DCCPO_MAX = 45,
 169         DCCPO_MIN_RX_CCID_SPECIFIC = 128,       /* from sender to receiver */
 170         DCCPO_MAX_RX_CCID_SPECIFIC = 191,
 171         DCCPO_MIN_TX_CCID_SPECIFIC = 192,       /* from receiver to sender */
 172         DCCPO_MAX_TX_CCID_SPECIFIC = 255,
 173 };
 174 /* maximum size of a single TLV-encoded DCCP option (sans type/len bytes) */
 175 #define DCCP_SINGLE_OPT_MAXLEN  253
 176
 177 /* DCCP CCIDS */
 178 enum {
 179         DCCPC_CCID2 = 2,
 180         DCCPC_CCID3 = 3,
 181 };
 182
 183 /* DCCP features (RFC 4340 section 6.4) */
 184 enum dccp_feature_numbers {
 185         DCCPF_RESERVED = 0,
 186         DCCPF_CCID = 1,
 187         DCCPF_SHORT_SEQNOS = 2,
 188         DCCPF_SEQUENCE_WINDOW = 3,
 189         DCCPF_ECN_INCAPABLE = 4,
 190         DCCPF_ACK_RATIO = 5,
 191         DCCPF_SEND_ACK_VECTOR = 6,
 192         DCCPF_SEND_NDP_COUNT = 7,
 193         DCCPF_MIN_CSUM_COVER = 8,
 194         DCCPF_DATA_CHECKSUM = 9,
 195         /* 10-127 reserved */
 196         DCCPF_MIN_CCID_SPECIFIC = 128,
 197         DCCPF_SEND_LEV_RATE = 192,      /* RFC 4342, sec. 8.4 */
 198         DCCPF_MAX_CCID_SPECIFIC = 255,
 199 };
 200
 201 /* DCCP socket control message types for cmsg */
 202 enum dccp_cmsg_type {
 203         DCCP_SCM_PRIORITY = 1,
 204         DCCP_SCM_QPOLICY_MAX = 0xFFFF,
 205         /* ^-- Up to here reserved exclusively for qpolicy parameters */
 206         DCCP_SCM_MAX
 207 };
 208
 209 /* DCCP priorities for outgoing/queued packets */
 210 enum dccp_packet_dequeueing_policy {
 211         DCCPQ_POLICY_SIMPLE,
 212         DCCPQ_POLICY_PRIO,
 213         DCCPQ_POLICY_MAX
 214 };
 215
 216 /* DCCP socket options */
 217 #define DCCP_SOCKOPT_PACKET_SIZE        1 /* XXX deprecated, without effect */
 218 #define DCCP_SOCKOPT_SERVICE            2
 219 #define DCCP_SOCKOPT_CHANGE_L           3
 220 #define DCCP_SOCKOPT_CHANGE_R           4
 221 #define DCCP_SOCKOPT_GET_CUR_MPS        5
 222 #define DCCP_SOCKOPT_SERVER_TIMEWAIT    6
 223 #define DCCP_SOCKOPT_SEND_CSCOV         10
 224 #define DCCP_SOCKOPT_RECV_CSCOV         11
 225 #define DCCP_SOCKOPT_AVAILABLE_CCIDS    12
 226 #define DCCP_SOCKOPT_CCID               13
 227 #define DCCP_SOCKOPT_TX_CCID            14
 228 #define DCCP_SOCKOPT_RX_CCID            15
 229 #define DCCP_SOCKOPT_QPOLICY_ID         16
 230 #define DCCP_SOCKOPT_QPOLICY_TXQLEN     17
 231 #define DCCP_SOCKOPT_CCID_RX_INFO       128
 232 #define DCCP_SOCKOPT_CCID_TX_INFO       192
 233
 234 /* maximum number of services provided on the same listening port */
 235 #define DCCP_SERVICE_LIST_MAX_LEN      32
 236
 237
 238 #endif /* _UAPI_LINUX_DCCP_H */