1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_DCCP_H
3#define _LINUX_DCCP_H
4
5
6#include <linux/in.h>
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>
12
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>
18
19enum dccp_state {
20 DCCP_OPEN = TCP_ESTABLISHED,
21 DCCP_REQUESTING = TCP_SYN_SENT,
22 DCCP_LISTEN = TCP_LISTEN,
23 DCCP_RESPOND = TCP_SYN_RECV,
24 /*
25 * States involved in closing a DCCP connection:
26 * 1) ACTIVE_CLOSEREQ is entered by a server sending a CloseReq.
27 *
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.
36 *
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).
41 */
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 */
50 DCCP_MAX_STATES
51};
52
53enum {
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),
64};
65
66static inline struct dccp_hdr *dccp_hdr(const struct sk_buff *skb)
67{
68 return (struct dccp_hdr *)skb_transport_header(skb);
69}
70
71static inline struct dccp_hdr *dccp_zeroed_hdr(struct sk_buff *skb, int headlen)
72{
73 skb_push(skb, headlen);
74 skb_reset_transport_header(skb);
75 return memset(skb_transport_header(skb), 0, headlen);
76}
77
78static inline struct dccp_hdr_ext *dccp_hdrx(const struct dccp_hdr *dh)
79{
80 return (struct dccp_hdr_ext *)((unsigned char *)dh + sizeof(*dh));
81}
82
83static inline unsigned int __dccp_basic_hdr_len(const struct dccp_hdr *dh)
84{
85 return sizeof(*dh) + (dh->dccph_x ? sizeof(struct dccp_hdr_ext) : 0);
86}
87
88static inline unsigned int dccp_basic_hdr_len(const struct sk_buff *skb)
89{
90 const struct dccp_hdr *dh = dccp_hdr(skb);
91 return __dccp_basic_hdr_len(dh);
92}
93
94static inline __u64 dccp_hdr_seq(const struct dccp_hdr *dh)
95{
96 __u64 seq_nr = ntohs(dh->dccph_seq);
97
98 if (dh->dccph_x != 0)
99 seq_nr = (seq_nr << 32) + ntohl(dccp_hdrx(dh)->dccph_seq_low);
100 else
101 seq_nr += (u32)dh->dccph_seq2 << 16;
102
103 return seq_nr;
104}
105
106static inline struct dccp_hdr_request *dccp_hdr_request(struct sk_buff *skb)
107{
108 return (struct dccp_hdr_request *)(skb_transport_header(skb) +
109 dccp_basic_hdr_len(skb));
110}
111
112static inline struct dccp_hdr_ack_bits *dccp_hdr_ack_bits(const struct sk_buff *skb)
113{
114 return (struct dccp_hdr_ack_bits *)(skb_transport_header(skb) +
115 dccp_basic_hdr_len(skb));
116}
117
118static inline u64 dccp_hdr_ack_seq(const struct sk_buff *skb)
119{
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);
122}
123
124static inline struct dccp_hdr_response *dccp_hdr_response(struct sk_buff *skb)
125{
126 return (struct dccp_hdr_response *)(skb_transport_header(skb) +
127 dccp_basic_hdr_len(skb));
128}
129
130static inline struct dccp_hdr_reset *dccp_hdr_reset(struct sk_buff *skb)
131{
132 return (struct dccp_hdr_reset *)(skb_transport_header(skb) +
133 dccp_basic_hdr_len(skb));
134}
135
136static inline unsigned int __dccp_hdr_len(const struct dccp_hdr *dh)
137{
138 return __dccp_basic_hdr_len(dh) +
139 dccp_packet_hdr_len(dh->dccph_type);
140}
141
142static inline unsigned int dccp_hdr_len(const struct sk_buff *skb)
143{
144 return __dccp_hdr_len(dccp_hdr(skb));
145}
146
147/**
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
159 */
160struct dccp_request_sock {
161 struct inet_request_sock dreq_inet_rsk;
162 __u64 dreq_iss;
163 __u64 dreq_gss;
164 __u64 dreq_isr;
165 __u64 dreq_gsr;
166 __be32 dreq_service;
167 spinlock_t dreq_lock;
168 struct list_head dreq_featneg;
169 __u32 dreq_timestamp_echo;
170 __u32 dreq_timestamp_time;
171};
172
173static inline struct dccp_request_sock *dccp_rsk(const struct request_sock *req)
174{
175 return (struct dccp_request_sock *)req;
176}
177
178extern struct inet_timewait_death_row dccp_death_row;
179
180extern int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq,
181 struct sk_buff *skb);
182
183struct dccp_options_received {
184 u64 dccpor_ndp:48;
185 u32 dccpor_timestamp;
186 u32 dccpor_timestamp_echo;
187 u32 dccpor_elapsed_time;
188};
189
190struct ccid;
191
192enum dccp_role {
193 DCCP_ROLE_UNDEFINED,
194 DCCP_ROLE_LISTEN,
195 DCCP_ROLE_CLIENT,
196 DCCP_ROLE_SERVER,
197};
198
199struct dccp_service_list {
200 __u32 dccpsl_nr;
201 __be32 dccpsl_list[0];
202};
203
204#define DCCP_SERVICE_INVALID_VALUE htonl((__u32)-1)
205#define DCCP_SERVICE_CODE_IS_ABSENT 0
206
207static inline bool dccp_list_has_service(const struct dccp_service_list *sl,
208 const __be32 service)
209{
210 if (likely(sl != NULL)) {
211 u32 i = sl->dccpsl_nr;
212 while (i--)
213 if (sl->dccpsl_list[i] == service)
214 return true;
215 }
216 return false;
217}
218
219struct dccp_ackvec;
220
221/**
222 * struct dccp_sock - DCCP socket state
223 *
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)
263 */
264struct dccp_sock {
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
268 __u64 dccps_swl;
269 __u64 dccps_swh;
270 __u64 dccps_awl;
271 __u64 dccps_awh;
272 __u64 dccps_iss;
273 __u64 dccps_isr;
274 __u64 dccps_osr;
275 __u64 dccps_gss;
276 __u64 dccps_gsr;
277 __u64 dccps_gar;
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;
287 __u8 dccps_pcslen:4;
288 __u8 dccps_pcrlen:4;
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;
297 __u8 dccps_qpolicy;
298 __u32 dccps_tx_qlen;
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;
306};
307
308static inline struct dccp_sock *dccp_sk(const struct sock *sk)
309{
310 return (struct dccp_sock *)sk;
311}
312
313static inline const char *dccp_role(const struct sock *sk)
314{
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";
320 }
321 return NULL;
322}
323
324extern void dccp_syn_ack_timeout(const struct request_sock *req);
325
326#endif /* _LINUX_DCCP_H */
327