xref: /openbmc/linux/include/linux/dccp.h (revision f7018c21)
1 #ifndef _LINUX_DCCP_H
2 #define _LINUX_DCCP_H
3 
4 
5 #include <linux/in.h>
6 #include <linux/interrupt.h>
7 #include <linux/ktime.h>
8 #include <linux/list.h>
9 #include <linux/uio.h>
10 #include <linux/workqueue.h>
11 
12 #include <net/inet_connection_sock.h>
13 #include <net/inet_sock.h>
14 #include <net/inet_timewait_sock.h>
15 #include <net/tcp_states.h>
16 #include <uapi/linux/dccp.h>
17 
18 enum dccp_state {
19 	DCCP_OPEN	     = TCP_ESTABLISHED,
20 	DCCP_REQUESTING	     = TCP_SYN_SENT,
21 	DCCP_LISTEN	     = TCP_LISTEN,
22 	DCCP_RESPOND	     = TCP_SYN_RECV,
23 	/*
24 	 * States involved in closing a DCCP connection:
25 	 * 1) ACTIVE_CLOSEREQ is entered by a server sending a CloseReq.
26 	 *
27 	 * 2) CLOSING can have three different meanings (RFC 4340, 8.3):
28 	 *  a. Client has performed active-close, has sent a Close to the server
29 	 *     from state OPEN or PARTOPEN, and is waiting for the final Reset
30 	 *     (in this case, SOCK_DONE == 1).
31 	 *  b. Client is asked to perform passive-close, by receiving a CloseReq
32 	 *     in (PART)OPEN state. It sends a Close and waits for final Reset
33 	 *     (in this case, SOCK_DONE == 0).
34 	 *  c. Server performs an active-close as in (a), keeps TIMEWAIT state.
35 	 *
36 	 * 3) The following intermediate states are employed to give passively
37 	 *    closing nodes a chance to process their unread data:
38 	 *    - PASSIVE_CLOSE    (from OPEN => CLOSED) and
39 	 *    - PASSIVE_CLOSEREQ (from (PART)OPEN to CLOSING; case (b) above).
40 	 */
41 	DCCP_ACTIVE_CLOSEREQ = TCP_FIN_WAIT1,
42 	DCCP_PASSIVE_CLOSE   = TCP_CLOSE_WAIT,	/* any node receiving a Close */
43 	DCCP_CLOSING	     = TCP_CLOSING,
44 	DCCP_TIME_WAIT	     = TCP_TIME_WAIT,
45 	DCCP_CLOSED	     = TCP_CLOSE,
46 	DCCP_PARTOPEN	     = TCP_MAX_STATES,
47 	DCCP_PASSIVE_CLOSEREQ,			/* clients receiving CloseReq */
48 	DCCP_MAX_STATES
49 };
50 
51 enum {
52 	DCCPF_OPEN	      = TCPF_ESTABLISHED,
53 	DCCPF_REQUESTING      = TCPF_SYN_SENT,
54 	DCCPF_LISTEN	      = TCPF_LISTEN,
55 	DCCPF_RESPOND	      = TCPF_SYN_RECV,
56 	DCCPF_ACTIVE_CLOSEREQ = TCPF_FIN_WAIT1,
57 	DCCPF_CLOSING	      = TCPF_CLOSING,
58 	DCCPF_TIME_WAIT	      = TCPF_TIME_WAIT,
59 	DCCPF_CLOSED	      = TCPF_CLOSE,
60 	DCCPF_PARTOPEN	      = (1 << DCCP_PARTOPEN),
61 };
62 
63 static inline struct dccp_hdr *dccp_hdr(const struct sk_buff *skb)
64 {
65 	return (struct dccp_hdr *)skb_transport_header(skb);
66 }
67 
68 static inline struct dccp_hdr *dccp_zeroed_hdr(struct sk_buff *skb, int headlen)
69 {
70 	skb_push(skb, headlen);
71 	skb_reset_transport_header(skb);
72 	return memset(skb_transport_header(skb), 0, headlen);
73 }
74 
75 static inline struct dccp_hdr_ext *dccp_hdrx(const struct dccp_hdr *dh)
76 {
77 	return (struct dccp_hdr_ext *)((unsigned char *)dh + sizeof(*dh));
78 }
79 
80 static inline unsigned int __dccp_basic_hdr_len(const struct dccp_hdr *dh)
81 {
82 	return sizeof(*dh) + (dh->dccph_x ? sizeof(struct dccp_hdr_ext) : 0);
83 }
84 
85 static inline unsigned int dccp_basic_hdr_len(const struct sk_buff *skb)
86 {
87 	const struct dccp_hdr *dh = dccp_hdr(skb);
88 	return __dccp_basic_hdr_len(dh);
89 }
90 
91 static inline __u64 dccp_hdr_seq(const struct dccp_hdr *dh)
92 {
93 	__u64 seq_nr =  ntohs(dh->dccph_seq);
94 
95 	if (dh->dccph_x != 0)
96 		seq_nr = (seq_nr << 32) + ntohl(dccp_hdrx(dh)->dccph_seq_low);
97 	else
98 		seq_nr += (u32)dh->dccph_seq2 << 16;
99 
100 	return seq_nr;
101 }
102 
103 static inline struct dccp_hdr_request *dccp_hdr_request(struct sk_buff *skb)
104 {
105 	return (struct dccp_hdr_request *)(skb_transport_header(skb) +
106 					   dccp_basic_hdr_len(skb));
107 }
108 
109 static inline struct dccp_hdr_ack_bits *dccp_hdr_ack_bits(const struct sk_buff *skb)
110 {
111 	return (struct dccp_hdr_ack_bits *)(skb_transport_header(skb) +
112 					    dccp_basic_hdr_len(skb));
113 }
114 
115 static inline u64 dccp_hdr_ack_seq(const struct sk_buff *skb)
116 {
117 	const struct dccp_hdr_ack_bits *dhack = dccp_hdr_ack_bits(skb);
118 	return ((u64)ntohs(dhack->dccph_ack_nr_high) << 32) + ntohl(dhack->dccph_ack_nr_low);
119 }
120 
121 static inline struct dccp_hdr_response *dccp_hdr_response(struct sk_buff *skb)
122 {
123 	return (struct dccp_hdr_response *)(skb_transport_header(skb) +
124 					    dccp_basic_hdr_len(skb));
125 }
126 
127 static inline struct dccp_hdr_reset *dccp_hdr_reset(struct sk_buff *skb)
128 {
129 	return (struct dccp_hdr_reset *)(skb_transport_header(skb) +
130 					 dccp_basic_hdr_len(skb));
131 }
132 
133 static inline unsigned int __dccp_hdr_len(const struct dccp_hdr *dh)
134 {
135 	return __dccp_basic_hdr_len(dh) +
136 	       dccp_packet_hdr_len(dh->dccph_type);
137 }
138 
139 static inline unsigned int dccp_hdr_len(const struct sk_buff *skb)
140 {
141 	return __dccp_hdr_len(dccp_hdr(skb));
142 }
143 
144 /**
145  * struct dccp_request_sock  -  represent DCCP-specific connection request
146  * @dreq_inet_rsk: structure inherited from
147  * @dreq_iss: initial sequence number, sent on the first Response (RFC 4340, 7.1)
148  * @dreq_gss: greatest sequence number sent (for retransmitted Responses)
149  * @dreq_isr: initial sequence number received in the first Request
150  * @dreq_gsr: greatest sequence number received (for retransmitted Request(s))
151  * @dreq_service: service code present on the Request (there is just one)
152  * @dreq_featneg: feature negotiation options for this connection
153  * The following two fields are analogous to the ones in dccp_sock:
154  * @dreq_timestamp_echo: last received timestamp to echo (13.1)
155  * @dreq_timestamp_echo: the time of receiving the last @dreq_timestamp_echo
156  */
157 struct dccp_request_sock {
158 	struct inet_request_sock dreq_inet_rsk;
159 	__u64			 dreq_iss;
160 	__u64			 dreq_gss;
161 	__u64			 dreq_isr;
162 	__u64			 dreq_gsr;
163 	__be32			 dreq_service;
164 	struct list_head	 dreq_featneg;
165 	__u32			 dreq_timestamp_echo;
166 	__u32			 dreq_timestamp_time;
167 };
168 
169 static inline struct dccp_request_sock *dccp_rsk(const struct request_sock *req)
170 {
171 	return (struct dccp_request_sock *)req;
172 }
173 
174 extern struct inet_timewait_death_row dccp_death_row;
175 
176 extern int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq,
177 			      struct sk_buff *skb);
178 
179 struct dccp_options_received {
180 	u64	dccpor_ndp:48;
181 	u32	dccpor_timestamp;
182 	u32	dccpor_timestamp_echo;
183 	u32	dccpor_elapsed_time;
184 };
185 
186 struct ccid;
187 
188 enum dccp_role {
189 	DCCP_ROLE_UNDEFINED,
190 	DCCP_ROLE_LISTEN,
191 	DCCP_ROLE_CLIENT,
192 	DCCP_ROLE_SERVER,
193 };
194 
195 struct dccp_service_list {
196 	__u32	dccpsl_nr;
197 	__be32	dccpsl_list[0];
198 };
199 
200 #define DCCP_SERVICE_INVALID_VALUE htonl((__u32)-1)
201 #define DCCP_SERVICE_CODE_IS_ABSENT		0
202 
203 static inline int dccp_list_has_service(const struct dccp_service_list *sl,
204 					const __be32 service)
205 {
206 	if (likely(sl != NULL)) {
207 		u32 i = sl->dccpsl_nr;
208 		while (i--)
209 			if (sl->dccpsl_list[i] == service)
210 				return 1;
211 	}
212 	return 0;
213 }
214 
215 struct dccp_ackvec;
216 
217 /**
218  * struct dccp_sock - DCCP socket state
219  *
220  * @dccps_swl - sequence number window low
221  * @dccps_swh - sequence number window high
222  * @dccps_awl - acknowledgement number window low
223  * @dccps_awh - acknowledgement number window high
224  * @dccps_iss - initial sequence number sent
225  * @dccps_isr - initial sequence number received
226  * @dccps_osr - first OPEN sequence number received
227  * @dccps_gss - greatest sequence number sent
228  * @dccps_gsr - greatest valid sequence number received
229  * @dccps_gar - greatest valid ack number received on a non-Sync; initialized to %dccps_iss
230  * @dccps_service - first (passive sock) or unique (active sock) service code
231  * @dccps_service_list - second .. last service code on passive socket
232  * @dccps_timestamp_echo - latest timestamp received on a TIMESTAMP option
233  * @dccps_timestamp_time - time of receiving latest @dccps_timestamp_echo
234  * @dccps_l_ack_ratio - feature-local Ack Ratio
235  * @dccps_r_ack_ratio - feature-remote Ack Ratio
236  * @dccps_l_seq_win - local Sequence Window (influences ack number validity)
237  * @dccps_r_seq_win - remote Sequence Window (influences seq number validity)
238  * @dccps_pcslen - sender   partial checksum coverage (via sockopt)
239  * @dccps_pcrlen - receiver partial checksum coverage (via sockopt)
240  * @dccps_send_ndp_count - local Send NDP Count feature (7.7.2)
241  * @dccps_ndp_count - number of Non Data Packets since last data packet
242  * @dccps_mss_cache - current value of MSS (path MTU minus header sizes)
243  * @dccps_rate_last - timestamp for rate-limiting DCCP-Sync (RFC 4340, 7.5.4)
244  * @dccps_featneg - tracks feature-negotiation state (mostly during handshake)
245  * @dccps_hc_rx_ackvec - rx half connection ack vector
246  * @dccps_hc_rx_ccid - CCID used for the receiver (or receiving half-connection)
247  * @dccps_hc_tx_ccid - CCID used for the sender (or sending half-connection)
248  * @dccps_options_received - parsed set of retrieved options
249  * @dccps_qpolicy - TX dequeueing policy, one of %dccp_packet_dequeueing_policy
250  * @dccps_tx_qlen - maximum length of the TX queue
251  * @dccps_role - role of this sock, one of %dccp_role
252  * @dccps_hc_rx_insert_options - receiver wants to add options when acking
253  * @dccps_hc_tx_insert_options - sender wants to add options when sending
254  * @dccps_server_timewait - server holds timewait state on close (RFC 4340, 8.3)
255  * @dccps_sync_scheduled - flag which signals "send out-of-band message soon"
256  * @dccps_xmitlet - tasklet scheduled by the TX CCID to dequeue data packets
257  * @dccps_xmit_timer - used by the TX CCID to delay sending (rate-based pacing)
258  * @dccps_syn_rtt - RTT sample from Request/Response exchange (in usecs)
259  */
260 struct dccp_sock {
261 	/* inet_connection_sock has to be the first member of dccp_sock */
262 	struct inet_connection_sock	dccps_inet_connection;
263 #define dccps_syn_rtt			dccps_inet_connection.icsk_ack.lrcvtime
264 	__u64				dccps_swl;
265 	__u64				dccps_swh;
266 	__u64				dccps_awl;
267 	__u64				dccps_awh;
268 	__u64				dccps_iss;
269 	__u64				dccps_isr;
270 	__u64				dccps_osr;
271 	__u64				dccps_gss;
272 	__u64				dccps_gsr;
273 	__u64				dccps_gar;
274 	__be32				dccps_service;
275 	__u32				dccps_mss_cache;
276 	struct dccp_service_list	*dccps_service_list;
277 	__u32				dccps_timestamp_echo;
278 	__u32				dccps_timestamp_time;
279 	__u16				dccps_l_ack_ratio;
280 	__u16				dccps_r_ack_ratio;
281 	__u64				dccps_l_seq_win:48;
282 	__u64				dccps_r_seq_win:48;
283 	__u8				dccps_pcslen:4;
284 	__u8				dccps_pcrlen:4;
285 	__u8				dccps_send_ndp_count:1;
286 	__u64				dccps_ndp_count:48;
287 	unsigned long			dccps_rate_last;
288 	struct list_head		dccps_featneg;
289 	struct dccp_ackvec		*dccps_hc_rx_ackvec;
290 	struct ccid			*dccps_hc_rx_ccid;
291 	struct ccid			*dccps_hc_tx_ccid;
292 	struct dccp_options_received	dccps_options_received;
293 	__u8				dccps_qpolicy;
294 	__u32				dccps_tx_qlen;
295 	enum dccp_role			dccps_role:2;
296 	__u8				dccps_hc_rx_insert_options:1;
297 	__u8				dccps_hc_tx_insert_options:1;
298 	__u8				dccps_server_timewait:1;
299 	__u8				dccps_sync_scheduled:1;
300 	struct tasklet_struct		dccps_xmitlet;
301 	struct timer_list		dccps_xmit_timer;
302 };
303 
304 static inline struct dccp_sock *dccp_sk(const struct sock *sk)
305 {
306 	return (struct dccp_sock *)sk;
307 }
308 
309 static inline const char *dccp_role(const struct sock *sk)
310 {
311 	switch (dccp_sk(sk)->dccps_role) {
312 	case DCCP_ROLE_UNDEFINED: return "undefined";
313 	case DCCP_ROLE_LISTEN:	  return "listen";
314 	case DCCP_ROLE_SERVER:	  return "server";
315 	case DCCP_ROLE_CLIENT:	  return "client";
316 	}
317 	return NULL;
318 }
319 
320 extern void dccp_syn_ack_timeout(struct sock *sk, struct request_sock *req);
321 
322 #endif /* _LINUX_DCCP_H */
323