1 /* SPDX-License-Identifier: GPL-2.0 */
7 #include <linux/interrupt.h>
8 #include <linux/ktime.h>
9 #include <linux/list.h>
10 #include <linux/uio.h>
11 #include <linux/workqueue.h>
13 #include <net/inet_connection_sock.h>
14 #include <net/inet_sock.h>
15 #include <net/inet_timewait_sock.h>
16 #include <net/tcp_states.h>
17 #include <uapi/linux/dccp.h>
20 DCCP_OPEN
= TCP_ESTABLISHED
,
21 DCCP_REQUESTING
= TCP_SYN_SENT
,
22 DCCP_LISTEN
= TCP_LISTEN
,
23 DCCP_RESPOND
= TCP_SYN_RECV
,
25 * States involved in closing a DCCP connection:
26 * 1) ACTIVE_CLOSEREQ is entered by a server sending a CloseReq.
28 * 2) CLOSING can have three different meanings (RFC 4340, 8.3):
29 * a. Client has performed active-close, has sent a Close to the server
30 * from state OPEN or PARTOPEN, and is waiting for the final Reset
31 * (in this case, SOCK_DONE == 1).
32 * b. Client is asked to perform passive-close, by receiving a CloseReq
33 * in (PART)OPEN state. It sends a Close and waits for final Reset
34 * (in this case, SOCK_DONE == 0).
35 * c. Server performs an active-close as in (a), keeps TIMEWAIT state.
37 * 3) The following intermediate states are employed to give passively
38 * closing nodes a chance to process their unread data:
39 * - PASSIVE_CLOSE (from OPEN => CLOSED) and
40 * - PASSIVE_CLOSEREQ (from (PART)OPEN to CLOSING; case (b) above).
42 DCCP_ACTIVE_CLOSEREQ
= TCP_FIN_WAIT1
,
43 DCCP_PASSIVE_CLOSE
= TCP_CLOSE_WAIT
, /* any node receiving a Close */
44 DCCP_CLOSING
= TCP_CLOSING
,
45 DCCP_TIME_WAIT
= TCP_TIME_WAIT
,
46 DCCP_CLOSED
= TCP_CLOSE
,
47 DCCP_NEW_SYN_RECV
= TCP_NEW_SYN_RECV
,
48 DCCP_PARTOPEN
= TCP_MAX_STATES
,
49 DCCP_PASSIVE_CLOSEREQ
, /* clients receiving CloseReq */
54 DCCPF_OPEN
= TCPF_ESTABLISHED
,
55 DCCPF_REQUESTING
= TCPF_SYN_SENT
,
56 DCCPF_LISTEN
= TCPF_LISTEN
,
57 DCCPF_RESPOND
= TCPF_SYN_RECV
,
58 DCCPF_ACTIVE_CLOSEREQ
= TCPF_FIN_WAIT1
,
59 DCCPF_CLOSING
= TCPF_CLOSING
,
60 DCCPF_TIME_WAIT
= TCPF_TIME_WAIT
,
61 DCCPF_CLOSED
= TCPF_CLOSE
,
62 DCCPF_NEW_SYN_RECV
= TCPF_NEW_SYN_RECV
,
63 DCCPF_PARTOPEN
= (1 << DCCP_PARTOPEN
),
66 static inline struct dccp_hdr
*dccp_hdr(const struct sk_buff
*skb
)
68 return (struct dccp_hdr
*)skb_transport_header(skb
);
71 static inline struct dccp_hdr
*dccp_zeroed_hdr(struct sk_buff
*skb
, int headlen
)
73 skb_push(skb
, headlen
);
74 skb_reset_transport_header(skb
);
75 return memset(skb_transport_header(skb
), 0, headlen
);
78 static inline struct dccp_hdr_ext
*dccp_hdrx(const struct dccp_hdr
*dh
)
80 return (struct dccp_hdr_ext
*)((unsigned char *)dh
+ sizeof(*dh
));
83 static inline unsigned int __dccp_basic_hdr_len(const struct dccp_hdr
*dh
)
85 return sizeof(*dh
) + (dh
->dccph_x
? sizeof(struct dccp_hdr_ext
) : 0);
88 static inline unsigned int dccp_basic_hdr_len(const struct sk_buff
*skb
)
90 const struct dccp_hdr
*dh
= dccp_hdr(skb
);
91 return __dccp_basic_hdr_len(dh
);
94 static inline __u64
dccp_hdr_seq(const struct dccp_hdr
*dh
)
96 __u64 seq_nr
= ntohs(dh
->dccph_seq
);
99 seq_nr
= (seq_nr
<< 32) + ntohl(dccp_hdrx(dh
)->dccph_seq_low
);
101 seq_nr
+= (u32
)dh
->dccph_seq2
<< 16;
106 static inline struct dccp_hdr_request
*dccp_hdr_request(struct sk_buff
*skb
)
108 return (struct dccp_hdr_request
*)(skb_transport_header(skb
) +
109 dccp_basic_hdr_len(skb
));
112 static inline struct dccp_hdr_ack_bits
*dccp_hdr_ack_bits(const struct sk_buff
*skb
)
114 return (struct dccp_hdr_ack_bits
*)(skb_transport_header(skb
) +
115 dccp_basic_hdr_len(skb
));
118 static inline u64
dccp_hdr_ack_seq(const struct sk_buff
*skb
)
120 const struct dccp_hdr_ack_bits
*dhack
= dccp_hdr_ack_bits(skb
);
121 return ((u64
)ntohs(dhack
->dccph_ack_nr_high
) << 32) + ntohl(dhack
->dccph_ack_nr_low
);
124 static inline struct dccp_hdr_response
*dccp_hdr_response(struct sk_buff
*skb
)
126 return (struct dccp_hdr_response
*)(skb_transport_header(skb
) +
127 dccp_basic_hdr_len(skb
));
130 static inline struct dccp_hdr_reset
*dccp_hdr_reset(struct sk_buff
*skb
)
132 return (struct dccp_hdr_reset
*)(skb_transport_header(skb
) +
133 dccp_basic_hdr_len(skb
));
136 static inline unsigned int __dccp_hdr_len(const struct dccp_hdr
*dh
)
138 return __dccp_basic_hdr_len(dh
) +
139 dccp_packet_hdr_len(dh
->dccph_type
);
142 static inline unsigned int dccp_hdr_len(const struct sk_buff
*skb
)
144 return __dccp_hdr_len(dccp_hdr(skb
));
148 * struct dccp_request_sock - represent DCCP-specific connection request
149 * @dreq_inet_rsk: structure inherited from
150 * @dreq_iss: initial sequence number, sent on the first Response (RFC 4340, 7.1)
151 * @dreq_gss: greatest sequence number sent (for retransmitted Responses)
152 * @dreq_isr: initial sequence number received in the first Request
153 * @dreq_gsr: greatest sequence number received (for retransmitted Request(s))
154 * @dreq_service: service code present on the Request (there is just one)
155 * @dreq_featneg: feature negotiation options for this connection
156 * The following two fields are analogous to the ones in dccp_sock:
157 * @dreq_timestamp_echo: last received timestamp to echo (13.1)
158 * @dreq_timestamp_echo: the time of receiving the last @dreq_timestamp_echo
160 struct dccp_request_sock
{
161 struct inet_request_sock dreq_inet_rsk
;
167 spinlock_t dreq_lock
;
168 struct list_head dreq_featneg
;
169 __u32 dreq_timestamp_echo
;
170 __u32 dreq_timestamp_time
;
173 static inline struct dccp_request_sock
*dccp_rsk(const struct request_sock
*req
)
175 return (struct dccp_request_sock
*)req
;
178 extern struct inet_timewait_death_row dccp_death_row
;
180 extern int dccp_parse_options(struct sock
*sk
, struct dccp_request_sock
*dreq
,
181 struct sk_buff
*skb
);
183 struct dccp_options_received
{
185 u32 dccpor_timestamp
;
186 u32 dccpor_timestamp_echo
;
187 u32 dccpor_elapsed_time
;
199 struct dccp_service_list
{
201 __be32 dccpsl_list
[];
204 #define DCCP_SERVICE_INVALID_VALUE htonl((__u32)-1)
205 #define DCCP_SERVICE_CODE_IS_ABSENT 0
207 static inline bool dccp_list_has_service(const struct dccp_service_list
*sl
,
208 const __be32 service
)
210 if (likely(sl
!= NULL
)) {
211 u32 i
= sl
->dccpsl_nr
;
213 if (sl
->dccpsl_list
[i
] == service
)
222 * struct dccp_sock - DCCP socket state
224 * @dccps_swl - sequence number window low
225 * @dccps_swh - sequence number window high
226 * @dccps_awl - acknowledgement number window low
227 * @dccps_awh - acknowledgement number window high
228 * @dccps_iss - initial sequence number sent
229 * @dccps_isr - initial sequence number received
230 * @dccps_osr - first OPEN sequence number received
231 * @dccps_gss - greatest sequence number sent
232 * @dccps_gsr - greatest valid sequence number received
233 * @dccps_gar - greatest valid ack number received on a non-Sync; initialized to %dccps_iss
234 * @dccps_service - first (passive sock) or unique (active sock) service code
235 * @dccps_service_list - second .. last service code on passive socket
236 * @dccps_timestamp_echo - latest timestamp received on a TIMESTAMP option
237 * @dccps_timestamp_time - time of receiving latest @dccps_timestamp_echo
238 * @dccps_l_ack_ratio - feature-local Ack Ratio
239 * @dccps_r_ack_ratio - feature-remote Ack Ratio
240 * @dccps_l_seq_win - local Sequence Window (influences ack number validity)
241 * @dccps_r_seq_win - remote Sequence Window (influences seq number validity)
242 * @dccps_pcslen - sender partial checksum coverage (via sockopt)
243 * @dccps_pcrlen - receiver partial checksum coverage (via sockopt)
244 * @dccps_send_ndp_count - local Send NDP Count feature (7.7.2)
245 * @dccps_ndp_count - number of Non Data Packets since last data packet
246 * @dccps_mss_cache - current value of MSS (path MTU minus header sizes)
247 * @dccps_rate_last - timestamp for rate-limiting DCCP-Sync (RFC 4340, 7.5.4)
248 * @dccps_featneg - tracks feature-negotiation state (mostly during handshake)
249 * @dccps_hc_rx_ackvec - rx half connection ack vector
250 * @dccps_hc_rx_ccid - CCID used for the receiver (or receiving half-connection)
251 * @dccps_hc_tx_ccid - CCID used for the sender (or sending half-connection)
252 * @dccps_options_received - parsed set of retrieved options
253 * @dccps_qpolicy - TX dequeueing policy, one of %dccp_packet_dequeueing_policy
254 * @dccps_tx_qlen - maximum length of the TX queue
255 * @dccps_role - role of this sock, one of %dccp_role
256 * @dccps_hc_rx_insert_options - receiver wants to add options when acking
257 * @dccps_hc_tx_insert_options - sender wants to add options when sending
258 * @dccps_server_timewait - server holds timewait state on close (RFC 4340, 8.3)
259 * @dccps_sync_scheduled - flag which signals "send out-of-band message soon"
260 * @dccps_xmitlet - tasklet scheduled by the TX CCID to dequeue data packets
261 * @dccps_xmit_timer - used by the TX CCID to delay sending (rate-based pacing)
262 * @dccps_syn_rtt - RTT sample from Request/Response exchange (in usecs)
265 /* inet_connection_sock has to be the first member of dccp_sock */
266 struct inet_connection_sock dccps_inet_connection
;
267 #define dccps_syn_rtt dccps_inet_connection.icsk_ack.lrcvtime
278 __be32 dccps_service
;
279 __u32 dccps_mss_cache
;
280 struct dccp_service_list
*dccps_service_list
;
281 __u32 dccps_timestamp_echo
;
282 __u32 dccps_timestamp_time
;
283 __u16 dccps_l_ack_ratio
;
284 __u16 dccps_r_ack_ratio
;
285 __u64 dccps_l_seq_win
:48;
286 __u64 dccps_r_seq_win
:48;
289 __u8 dccps_send_ndp_count
:1;
290 __u64 dccps_ndp_count
:48;
291 unsigned long dccps_rate_last
;
292 struct list_head dccps_featneg
;
293 struct dccp_ackvec
*dccps_hc_rx_ackvec
;
294 struct ccid
*dccps_hc_rx_ccid
;
295 struct ccid
*dccps_hc_tx_ccid
;
296 struct dccp_options_received dccps_options_received
;
299 enum dccp_role dccps_role
:2;
300 __u8 dccps_hc_rx_insert_options
:1;
301 __u8 dccps_hc_tx_insert_options
:1;
302 __u8 dccps_server_timewait
:1;
303 __u8 dccps_sync_scheduled
:1;
304 struct tasklet_struct dccps_xmitlet
;
305 struct timer_list dccps_xmit_timer
;
308 static inline struct dccp_sock
*dccp_sk(const struct sock
*sk
)
310 return (struct dccp_sock
*)sk
;
313 static inline const char *dccp_role(const struct sock
*sk
)
315 switch (dccp_sk(sk
)->dccps_role
) {
316 case DCCP_ROLE_UNDEFINED
: return "undefined";
317 case DCCP_ROLE_LISTEN
: return "listen";
318 case DCCP_ROLE_SERVER
: return "server";
319 case DCCP_ROLE_CLIENT
: return "client";
324 extern void dccp_syn_ack_timeout(const struct request_sock
*req
);
326 #endif /* _LINUX_DCCP_H */