xref: /linux-6.15/include/linux/dccp.h (revision 4e57b681)
1 #ifndef _LINUX_DCCP_H
2 #define _LINUX_DCCP_H
3 
4 #include <linux/types.h>
5 #include <asm/byteorder.h>
6 
7 /**
8  * struct dccp_hdr - generic part of DCCP packet header
9  *
10  * @dccph_sport - Relevant port on the endpoint that sent this packet
11  * @dccph_dport - Relevant port on the other endpoint
12  * @dccph_doff - Data Offset from the start of the DCCP header, in 32-bit words
13  * @dccph_ccval - Used by the HC-Sender CCID
14  * @dccph_cscov - Parts of the packet that are covered by the Checksum field
15  * @dccph_checksum - Internet checksum, depends on dccph_cscov
16  * @dccph_x - 0 = 24 bit sequence number, 1 = 48
17  * @dccph_type - packet type, see DCCP_PKT_ prefixed macros
18  * @dccph_seq - sequence number high or low order 24 bits, depends on dccph_x
19  */
20 struct dccp_hdr {
21 	__u16	dccph_sport,
22 		dccph_dport;
23 	__u8	dccph_doff;
24 #if defined(__LITTLE_ENDIAN_BITFIELD)
25 	__u8	dccph_cscov:4,
26 		dccph_ccval:4;
27 #elif defined(__BIG_ENDIAN_BITFIELD)
28 	__u8	dccph_ccval:4,
29 		dccph_cscov:4;
30 #else
31 #error  "Adjust your <asm/byteorder.h> defines"
32 #endif
33 	__u16	dccph_checksum;
34 #if defined(__LITTLE_ENDIAN_BITFIELD)
35 	__u32	dccph_x:1,
36 		dccph_type:4,
37 		dccph_reserved:3,
38 		dccph_seq:24;
39 #elif defined(__BIG_ENDIAN_BITFIELD)
40 	__u32	dccph_reserved:3,
41 		dccph_type:4,
42 		dccph_x:1,
43 		dccph_seq:24;
44 #else
45 #error  "Adjust your <asm/byteorder.h> defines"
46 #endif
47 };
48 
49 /**
50  * struct dccp_hdr_ext - the low bits of a 48 bit seq packet
51  *
52  * @dccph_seq_low - low 24 bits of a 48 bit seq packet
53  */
54 struct dccp_hdr_ext {
55 	__u32	dccph_seq_low;
56 };
57 
58 /**
59  * struct dccp_hdr_request - Conection initiation request header
60  *
61  * @dccph_req_service - Service to which the client app wants to connect
62  * @dccph_req_options - list of options (must be a multiple of 32 bits
63  */
64 struct dccp_hdr_request {
65 	__u32	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 	__u32	dccph_reserved1:8,
75 		dccph_ack_nr_high:24;
76 	__u32	dccph_ack_nr_low;
77 };
78 /**
79  * struct dccp_hdr_response - Conection initiation response header
80  *
81  * @dccph_resp_ack_nr_high - 48 bit ack number high order bits, contains GSR
82  * @dccph_resp_ack_nr_low - 48 bit ack number low order bits, contains GSR
83  * @dccph_resp_service - Echoes the Service Code on a received DCCP-Request
84  * @dccph_resp_options - list of options (must be a multiple of 32 bits
85  */
86 struct dccp_hdr_response {
87 	struct dccp_hdr_ack_bits	dccph_resp_ack;
88 	__u32				dccph_resp_service;
89 };
90 
91 /**
92  * struct dccp_hdr_reset - Unconditionally shut down a connection
93  *
94  * @dccph_reset_service - Echoes the Service Code on a received DCCP-Request
95  * @dccph_reset_options - list of options (must be a multiple of 32 bits
96  */
97 struct dccp_hdr_reset {
98 	struct dccp_hdr_ack_bits	dccph_reset_ack;
99 	__u8				dccph_reset_code,
100 					dccph_reset_data[3];
101 };
102 
103 enum dccp_pkt_type {
104 	DCCP_PKT_REQUEST = 0,
105 	DCCP_PKT_RESPONSE,
106 	DCCP_PKT_DATA,
107 	DCCP_PKT_ACK,
108 	DCCP_PKT_DATAACK,
109 	DCCP_PKT_CLOSEREQ,
110 	DCCP_PKT_CLOSE,
111 	DCCP_PKT_RESET,
112 	DCCP_PKT_SYNC,
113 	DCCP_PKT_SYNCACK,
114 	DCCP_PKT_INVALID,
115 };
116 
117 #define DCCP_NR_PKT_TYPES DCCP_PKT_INVALID
118 
119 static inline unsigned int dccp_packet_hdr_len(const __u8 type)
120 {
121 	if (type == DCCP_PKT_DATA)
122 		return 0;
123 	if (type == DCCP_PKT_DATAACK	||
124 	    type == DCCP_PKT_ACK	||
125 	    type == DCCP_PKT_SYNC	||
126 	    type == DCCP_PKT_SYNCACK	||
127 	    type == DCCP_PKT_CLOSE	||
128 	    type == DCCP_PKT_CLOSEREQ)
129 		return sizeof(struct dccp_hdr_ack_bits);
130 	if (type == DCCP_PKT_REQUEST)
131 		return sizeof(struct dccp_hdr_request);
132 	if (type == DCCP_PKT_RESPONSE)
133 		return sizeof(struct dccp_hdr_response);
134 	return sizeof(struct dccp_hdr_reset);
135 }
136 enum dccp_reset_codes {
137 	DCCP_RESET_CODE_UNSPECIFIED = 0,
138 	DCCP_RESET_CODE_CLOSED,
139 	DCCP_RESET_CODE_ABORTED,
140 	DCCP_RESET_CODE_NO_CONNECTION,
141 	DCCP_RESET_CODE_PACKET_ERROR,
142 	DCCP_RESET_CODE_OPTION_ERROR,
143 	DCCP_RESET_CODE_MANDATORY_ERROR,
144 	DCCP_RESET_CODE_CONNECTION_REFUSED,
145 	DCCP_RESET_CODE_BAD_SERVICE_CODE,
146 	DCCP_RESET_CODE_TOO_BUSY,
147 	DCCP_RESET_CODE_BAD_INIT_COOKIE,
148 	DCCP_RESET_CODE_AGGRESSION_PENALTY,
149 };
150 
151 /* DCCP options */
152 enum {
153 	DCCPO_PADDING = 0,
154 	DCCPO_MANDATORY = 1,
155 	DCCPO_MIN_RESERVED = 3,
156 	DCCPO_MAX_RESERVED = 31,
157 	DCCPO_NDP_COUNT = 37,
158 	DCCPO_ACK_VECTOR_0 = 38,
159 	DCCPO_ACK_VECTOR_1 = 39,
160 	DCCPO_TIMESTAMP = 41,
161 	DCCPO_TIMESTAMP_ECHO = 42,
162 	DCCPO_ELAPSED_TIME = 43,
163 	DCCPO_MAX = 45,
164 	DCCPO_MIN_CCID_SPECIFIC = 128,
165 	DCCPO_MAX_CCID_SPECIFIC = 255,
166 };
167 
168 /* DCCP features */
169 enum {
170 	DCCPF_RESERVED = 0,
171 	DCCPF_SEQUENCE_WINDOW = 3,
172 	DCCPF_SEND_ACK_VECTOR = 6,
173 	DCCPF_SEND_NDP_COUNT = 7,
174 	/* 10-127 reserved */
175 	DCCPF_MIN_CCID_SPECIFIC = 128,
176 	DCCPF_MAX_CCID_SPECIFIC = 255,
177 };
178 
179 /* DCCP socket options */
180 #define DCCP_SOCKOPT_PACKET_SIZE	1
181 #define DCCP_SOCKOPT_SERVICE		2
182 #define DCCP_SOCKOPT_CCID_RX_INFO	128
183 #define DCCP_SOCKOPT_CCID_TX_INFO	192
184 
185 #define DCCP_SERVICE_LIST_MAX_LEN      32
186 
187 #ifdef __KERNEL__
188 
189 #include <linux/in.h>
190 #include <linux/list.h>
191 #include <linux/uio.h>
192 #include <linux/workqueue.h>
193 
194 #include <net/inet_connection_sock.h>
195 #include <net/inet_timewait_sock.h>
196 #include <net/sock.h>
197 #include <net/tcp_states.h>
198 #include <net/tcp.h>
199 
200 enum dccp_state {
201 	DCCP_OPEN	= TCP_ESTABLISHED,
202 	DCCP_REQUESTING	= TCP_SYN_SENT,
203 	DCCP_PARTOPEN	= TCP_FIN_WAIT1, /* FIXME:
204 					    This mapping is horrible, but TCP has
205 					    no matching state for DCCP_PARTOPEN,
206 					    as TCP_SYN_RECV is already used by
207 					    DCCP_RESPOND, why don't stop using TCP
208 					    mapping of states? OK, now we don't use
209 					    sk_stream_sendmsg anymore, so doesn't
210 					    seem to exist any reason for us to
211 					    do the TCP mapping here */
212 	DCCP_LISTEN	= TCP_LISTEN,
213 	DCCP_RESPOND	= TCP_SYN_RECV,
214 	DCCP_CLOSING	= TCP_CLOSING,
215 	DCCP_TIME_WAIT	= TCP_TIME_WAIT,
216 	DCCP_CLOSED	= TCP_CLOSE,
217 	DCCP_MAX_STATES = TCP_MAX_STATES,
218 };
219 
220 #define DCCP_STATE_MASK 0xf
221 #define DCCP_ACTION_FIN (1<<7)
222 
223 enum {
224 	DCCPF_OPEN	 = TCPF_ESTABLISHED,
225 	DCCPF_REQUESTING = TCPF_SYN_SENT,
226 	DCCPF_PARTOPEN	 = TCPF_FIN_WAIT1,
227 	DCCPF_LISTEN	 = TCPF_LISTEN,
228 	DCCPF_RESPOND	 = TCPF_SYN_RECV,
229 	DCCPF_CLOSING	 = TCPF_CLOSING,
230 	DCCPF_TIME_WAIT	 = TCPF_TIME_WAIT,
231 	DCCPF_CLOSED	 = TCPF_CLOSE,
232 };
233 
234 static inline struct dccp_hdr *dccp_hdr(const struct sk_buff *skb)
235 {
236 	return (struct dccp_hdr *)skb->h.raw;
237 }
238 
239 static inline struct dccp_hdr_ext *dccp_hdrx(const struct sk_buff *skb)
240 {
241 	return (struct dccp_hdr_ext *)(skb->h.raw + sizeof(struct dccp_hdr));
242 }
243 
244 static inline unsigned int __dccp_basic_hdr_len(const struct dccp_hdr *dh)
245 {
246 	return sizeof(*dh) + (dh->dccph_x ? sizeof(struct dccp_hdr_ext) : 0);
247 }
248 
249 static inline unsigned int dccp_basic_hdr_len(const struct sk_buff *skb)
250 {
251 	const struct dccp_hdr *dh = dccp_hdr(skb);
252 	return __dccp_basic_hdr_len(dh);
253 }
254 
255 static inline __u64 dccp_hdr_seq(const struct sk_buff *skb)
256 {
257 	const struct dccp_hdr *dh = dccp_hdr(skb);
258 #if defined(__LITTLE_ENDIAN_BITFIELD)
259 	__u64 seq_nr = ntohl(dh->dccph_seq << 8);
260 #elif defined(__BIG_ENDIAN_BITFIELD)
261 	__u64 seq_nr = ntohl(dh->dccph_seq);
262 #else
263 #error  "Adjust your <asm/byteorder.h> defines"
264 #endif
265 
266 	if (dh->dccph_x != 0)
267 		seq_nr = (seq_nr << 32) + ntohl(dccp_hdrx(skb)->dccph_seq_low);
268 
269 	return seq_nr;
270 }
271 
272 static inline struct dccp_hdr_request *dccp_hdr_request(struct sk_buff *skb)
273 {
274 	return (struct dccp_hdr_request *)(skb->h.raw + dccp_basic_hdr_len(skb));
275 }
276 
277 static inline struct dccp_hdr_ack_bits *dccp_hdr_ack_bits(const struct sk_buff *skb)
278 {
279 	return (struct dccp_hdr_ack_bits *)(skb->h.raw + dccp_basic_hdr_len(skb));
280 }
281 
282 static inline u64 dccp_hdr_ack_seq(const struct sk_buff *skb)
283 {
284 	const struct dccp_hdr_ack_bits *dhack = dccp_hdr_ack_bits(skb);
285 #if defined(__LITTLE_ENDIAN_BITFIELD)
286 	return (((u64)ntohl(dhack->dccph_ack_nr_high << 8)) << 32) + ntohl(dhack->dccph_ack_nr_low);
287 #elif defined(__BIG_ENDIAN_BITFIELD)
288 	return (((u64)ntohl(dhack->dccph_ack_nr_high)) << 32) + ntohl(dhack->dccph_ack_nr_low);
289 #else
290 #error  "Adjust your <asm/byteorder.h> defines"
291 #endif
292 }
293 
294 static inline struct dccp_hdr_response *dccp_hdr_response(struct sk_buff *skb)
295 {
296 	return (struct dccp_hdr_response *)(skb->h.raw + dccp_basic_hdr_len(skb));
297 }
298 
299 static inline struct dccp_hdr_reset *dccp_hdr_reset(struct sk_buff *skb)
300 {
301 	return (struct dccp_hdr_reset *)(skb->h.raw + dccp_basic_hdr_len(skb));
302 }
303 
304 static inline unsigned int __dccp_hdr_len(const struct dccp_hdr *dh)
305 {
306 	return __dccp_basic_hdr_len(dh) +
307 	       dccp_packet_hdr_len(dh->dccph_type);
308 }
309 
310 static inline unsigned int dccp_hdr_len(const struct sk_buff *skb)
311 {
312 	return __dccp_hdr_len(dccp_hdr(skb));
313 }
314 
315 
316 /* initial values for each feature */
317 #define DCCPF_INITIAL_SEQUENCE_WINDOW		100
318 /* FIXME: for now we're using CCID 3 (TFRC) */
319 #define DCCPF_INITIAL_CCID			3
320 #define DCCPF_INITIAL_SEND_ACK_VECTOR		0
321 /* FIXME: for now we're default to 1 but it should really be 0 */
322 #define DCCPF_INITIAL_SEND_NDP_COUNT		1
323 
324 #define DCCP_NDP_LIMIT 0xFFFFFF
325 
326 /**
327   * struct dccp_options - option values for a DCCP connection
328   *	@dccpo_sequence_window - Sequence Window Feature (section 7.5.2)
329   *	@dccpo_ccid - Congestion Control Id (CCID) (section 10)
330   *	@dccpo_send_ack_vector - Send Ack Vector Feature (section 11.5)
331   *	@dccpo_send_ndp_count - Send NDP Count Feature (7.7.2)
332   */
333 struct dccp_options {
334 	__u64	dccpo_sequence_window;
335 	__u8	dccpo_rx_ccid;
336 	__u8	dccpo_tx_ccid;
337 	__u8	dccpo_send_ack_vector;
338 	__u8	dccpo_send_ndp_count;
339 };
340 
341 extern void __dccp_options_init(struct dccp_options *dccpo);
342 extern void dccp_options_init(struct dccp_options *dccpo);
343 extern int dccp_parse_options(struct sock *sk, struct sk_buff *skb);
344 
345 struct dccp_request_sock {
346 	struct inet_request_sock dreq_inet_rsk;
347 	__u64			 dreq_iss;
348 	__u64			 dreq_isr;
349 	__u32			 dreq_service;
350 };
351 
352 static inline struct dccp_request_sock *dccp_rsk(const struct request_sock *req)
353 {
354 	return (struct dccp_request_sock *)req;
355 }
356 
357 extern struct inet_timewait_death_row dccp_death_row;
358 
359 struct dccp_options_received {
360 	u32	dccpor_ndp; /* only 24 bits */
361 	u32	dccpor_timestamp;
362 	u32	dccpor_timestamp_echo;
363 	u32	dccpor_elapsed_time;
364 };
365 
366 struct ccid;
367 
368 enum dccp_role {
369 	DCCP_ROLE_UNDEFINED,
370 	DCCP_ROLE_LISTEN,
371 	DCCP_ROLE_CLIENT,
372 	DCCP_ROLE_SERVER,
373 };
374 
375 struct dccp_service_list {
376 	__u32	dccpsl_nr;
377 	__u32	dccpsl_list[0];
378 };
379 
380 #define DCCP_SERVICE_INVALID_VALUE htonl((__u32)-1)
381 
382 static inline int dccp_list_has_service(const struct dccp_service_list *sl,
383 					const u32 service)
384 {
385 	if (likely(sl != NULL)) {
386 		u32 i = sl->dccpsl_nr;
387 		while (i--)
388 			if (sl->dccpsl_list[i] == service)
389 				return 1;
390 	}
391 	return 0;
392 }
393 
394 struct dccp_ackvec;
395 
396 /**
397  * struct dccp_sock - DCCP socket state
398  *
399  * @dccps_swl - sequence number window low
400  * @dccps_swh - sequence number window high
401  * @dccps_awl - acknowledgement number window low
402  * @dccps_awh - acknowledgement number window high
403  * @dccps_iss - initial sequence number sent
404  * @dccps_isr - initial sequence number received
405  * @dccps_osr - first OPEN sequence number received
406  * @dccps_gss - greatest sequence number sent
407  * @dccps_gsr - greatest valid sequence number received
408  * @dccps_gar - greatest valid ack number received on a non-Sync; initialized to %dccps_iss
409  * @dccps_timestamp_time - time of latest TIMESTAMP option
410  * @dccps_timestamp_echo - latest timestamp received on a TIMESTAMP option
411  * @dccps_ext_header_len - network protocol overhead (IP/IPv6 options)
412  * @dccps_pmtu_cookie - Last pmtu seen by socket
413  * @dccps_packet_size - Set thru setsockopt
414  * @dccps_role - Role of this sock, one of %dccp_role
415  * @dccps_ndp_count - number of Non Data Packets since last data packet
416  * @dccps_hc_rx_ackvec - rx half connection ack vector
417  */
418 struct dccp_sock {
419 	/* inet_connection_sock has to be the first member of dccp_sock */
420 	struct inet_connection_sock	dccps_inet_connection;
421 	__u64				dccps_swl;
422 	__u64				dccps_swh;
423 	__u64				dccps_awl;
424 	__u64				dccps_awh;
425 	__u64				dccps_iss;
426 	__u64				dccps_isr;
427 	__u64				dccps_osr;
428 	__u64				dccps_gss;
429 	__u64				dccps_gsr;
430 	__u64				dccps_gar;
431 	__u32				dccps_service;
432 	struct dccp_service_list	*dccps_service_list;
433 	struct timeval			dccps_timestamp_time;
434 	__u32				dccps_timestamp_echo;
435 	__u32				dccps_packet_size;
436 	unsigned long			dccps_ndp_count;
437 	__u16				dccps_ext_header_len;
438 	__u32				dccps_pmtu_cookie;
439 	__u32				dccps_mss_cache;
440 	struct dccp_options		dccps_options;
441 	struct dccp_ackvec		*dccps_hc_rx_ackvec;
442 	void				*dccps_hc_rx_ccid_private;
443 	void				*dccps_hc_tx_ccid_private;
444 	struct ccid			*dccps_hc_rx_ccid;
445 	struct ccid			*dccps_hc_tx_ccid;
446 	struct dccp_options_received	dccps_options_received;
447 	struct timeval			dccps_epoch;
448 	enum dccp_role			dccps_role:2;
449 	__u8				dccps_hc_rx_insert_options:1;
450 	__u8				dccps_hc_tx_insert_options:1;
451 };
452 
453 static inline struct dccp_sock *dccp_sk(const struct sock *sk)
454 {
455 	return (struct dccp_sock *)sk;
456 }
457 
458 static inline int dccp_service_not_initialized(const struct sock *sk)
459 {
460 	return dccp_sk(sk)->dccps_service == DCCP_SERVICE_INVALID_VALUE;
461 }
462 
463 static inline const char *dccp_role(const struct sock *sk)
464 {
465 	switch (dccp_sk(sk)->dccps_role) {
466 	case DCCP_ROLE_UNDEFINED: return "undefined";
467 	case DCCP_ROLE_LISTEN:	  return "listen";
468 	case DCCP_ROLE_SERVER:	  return "server";
469 	case DCCP_ROLE_CLIENT:	  return "client";
470 	}
471 	return NULL;
472 }
473 
474 #endif /* __KERNEL__ */
475 
476 #endif /* _LINUX_DCCP_H */
477