xref: /openbmc/linux/include/linux/dccp.h (revision ae6084b7)
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 
19 enum 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 
53 enum {
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 
dccp_hdr(const struct sk_buff * skb)66 static inline struct dccp_hdr *dccp_hdr(const struct sk_buff *skb)
67 {
68 	return (struct dccp_hdr *)skb_transport_header(skb);
69 }
70 
dccp_zeroed_hdr(struct sk_buff * skb,int headlen)71 static 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 
dccp_hdrx(const struct dccp_hdr * dh)78 static 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 
__dccp_basic_hdr_len(const struct dccp_hdr * dh)83 static 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 
dccp_basic_hdr_len(const struct sk_buff * skb)88 static 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 
dccp_hdr_seq(const struct dccp_hdr * dh)94 static 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 
dccp_hdr_request(struct sk_buff * skb)106 static 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 
dccp_hdr_ack_bits(const struct sk_buff * skb)112 static 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 
dccp_hdr_ack_seq(const struct sk_buff * skb)118 static 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 
dccp_hdr_response(struct sk_buff * skb)124 static 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 
dccp_hdr_reset(struct sk_buff * skb)130 static 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 
__dccp_hdr_len(const struct dccp_hdr * dh)136 static 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 
dccp_hdr_len(const struct sk_buff * skb)142 static 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  */
160 struct 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 
dccp_rsk(const struct request_sock * req)173 static inline struct dccp_request_sock *dccp_rsk(const struct request_sock *req)
174 {
175 	return (struct dccp_request_sock *)req;
176 }
177 
178 extern struct inet_timewait_death_row dccp_death_row;
179 
180 extern int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq,
181 			      struct sk_buff *skb);
182 
183 struct dccp_options_received {
184 	u64	dccpor_ndp:48;
185 	u32	dccpor_timestamp;
186 	u32	dccpor_timestamp_echo;
187 	u32	dccpor_elapsed_time;
188 };
189 
190 struct ccid;
191 
192 enum dccp_role {
193 	DCCP_ROLE_UNDEFINED,
194 	DCCP_ROLE_LISTEN,
195 	DCCP_ROLE_CLIENT,
196 	DCCP_ROLE_SERVER,
197 };
198 
199 struct dccp_service_list {
200 	__u32	dccpsl_nr;
201 	__be32	dccpsl_list[];
202 };
203 
204 #define DCCP_SERVICE_INVALID_VALUE htonl((__u32)-1)
205 #define DCCP_SERVICE_CODE_IS_ABSENT		0
206 
dccp_list_has_service(const struct dccp_service_list * sl,const __be32 service)207 static 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 
219 struct 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  */
264 struct 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 
308 #define dccp_sk(ptr)	container_of_const(ptr, struct dccp_sock, \
309 					   dccps_inet_connection.icsk_inet.sk)
310 
dccp_role(const struct sock * sk)311 static inline const char *dccp_role(const struct sock *sk)
312 {
313 	switch (dccp_sk(sk)->dccps_role) {
314 	case DCCP_ROLE_UNDEFINED: return "undefined";
315 	case DCCP_ROLE_LISTEN:	  return "listen";
316 	case DCCP_ROLE_SERVER:	  return "server";
317 	case DCCP_ROLE_CLIENT:	  return "client";
318 	}
319 	return NULL;
320 }
321 
322 extern void dccp_syn_ack_timeout(const struct request_sock *req);
323 
324 #endif /* _LINUX_DCCP_H */
325