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
dccp_packet_hdr_len(const __u8 type)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 */
239