1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /* SCTP kernel implementation
3 * (C) Copyright IBM Corp. 2001, 2004
4 * Copyright (c) 1999-2000 Cisco, Inc.
5 * Copyright (c) 1999-2001 Motorola, Inc.
6 * Copyright (c) 2001 Intel Corp.
7 *
8 * This file is part of the SCTP kernel implementation
9 *
10 * Please send any bug reports or fixes you make to the
11 * email address(es):
12 * lksctp developers <linux-sctp@vger.kernel.org>
13 *
14 * Written or modified by:
15 * La Monte H.P. Yarroll <piggy@acm.org>
16 * Karl Knutson <karl@athena.chicago.il.us>
17 * Randall Stewart <randall@stewart.chicago.il.us>
18 * Ken Morneau <kmorneau@cisco.com>
19 * Qiaobing Xie <qxie1@motorola.com>
20 * Xingang Guo <xingang.guo@intel.com>
21 * Sridhar Samudrala <samudrala@us.ibm.com>
22 * Daisy Chang <daisyc@us.ibm.com>
23 */
24
25 #ifndef __sctp_constants_h__
26 #define __sctp_constants_h__
27
28 #include <linux/sctp.h>
29 #include <linux/ipv6.h> /* For ipv6hdr. */
30 #include <net/tcp_states.h> /* For TCP states used in enum sctp_sock_state */
31
32 /* Value used for stream negotiation. */
33 enum { SCTP_MAX_STREAM = 0xffff };
34 enum { SCTP_DEFAULT_OUTSTREAMS = 10 };
35 enum { SCTP_DEFAULT_INSTREAMS = SCTP_MAX_STREAM };
36
37 /* Since CIDs are sparse, we need all four of the following
38 * symbols. CIDs are dense through SCTP_CID_BASE_MAX.
39 */
40 #define SCTP_CID_BASE_MAX SCTP_CID_SHUTDOWN_COMPLETE
41
42 #define SCTP_NUM_BASE_CHUNK_TYPES (SCTP_CID_BASE_MAX + 1)
43
44 #define SCTP_NUM_ADDIP_CHUNK_TYPES 2
45
46 #define SCTP_NUM_PRSCTP_CHUNK_TYPES 1
47
48 #define SCTP_NUM_RECONF_CHUNK_TYPES 1
49
50 #define SCTP_NUM_AUTH_CHUNK_TYPES 1
51
52 #define SCTP_NUM_CHUNK_TYPES (SCTP_NUM_BASE_CHUNK_TYPES + \
53 SCTP_NUM_ADDIP_CHUNK_TYPES +\
54 SCTP_NUM_PRSCTP_CHUNK_TYPES +\
55 SCTP_NUM_RECONF_CHUNK_TYPES +\
56 SCTP_NUM_AUTH_CHUNK_TYPES)
57
58 /* These are the different flavours of event. */
59 enum sctp_event_type {
60 SCTP_EVENT_T_CHUNK = 1,
61 SCTP_EVENT_T_TIMEOUT,
62 SCTP_EVENT_T_OTHER,
63 SCTP_EVENT_T_PRIMITIVE
64 };
65
66 /* As a convenience for the state machine, we append SCTP_EVENT_* and
67 * SCTP_ULP_* to the list of possible chunks.
68 */
69
70 enum sctp_event_timeout {
71 SCTP_EVENT_TIMEOUT_NONE = 0,
72 SCTP_EVENT_TIMEOUT_T1_COOKIE,
73 SCTP_EVENT_TIMEOUT_T1_INIT,
74 SCTP_EVENT_TIMEOUT_T2_SHUTDOWN,
75 SCTP_EVENT_TIMEOUT_T3_RTX,
76 SCTP_EVENT_TIMEOUT_T4_RTO,
77 SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD,
78 SCTP_EVENT_TIMEOUT_HEARTBEAT,
79 SCTP_EVENT_TIMEOUT_RECONF,
80 SCTP_EVENT_TIMEOUT_PROBE,
81 SCTP_EVENT_TIMEOUT_SACK,
82 SCTP_EVENT_TIMEOUT_AUTOCLOSE,
83 };
84
85 #define SCTP_EVENT_TIMEOUT_MAX SCTP_EVENT_TIMEOUT_AUTOCLOSE
86 #define SCTP_NUM_TIMEOUT_TYPES (SCTP_EVENT_TIMEOUT_MAX + 1)
87
88 enum sctp_event_other {
89 SCTP_EVENT_NO_PENDING_TSN = 0,
90 SCTP_EVENT_ICMP_PROTO_UNREACH,
91 };
92
93 #define SCTP_EVENT_OTHER_MAX SCTP_EVENT_ICMP_PROTO_UNREACH
94 #define SCTP_NUM_OTHER_TYPES (SCTP_EVENT_OTHER_MAX + 1)
95
96 /* These are primitive requests from the ULP. */
97 enum sctp_event_primitive {
98 SCTP_PRIMITIVE_ASSOCIATE = 0,
99 SCTP_PRIMITIVE_SHUTDOWN,
100 SCTP_PRIMITIVE_ABORT,
101 SCTP_PRIMITIVE_SEND,
102 SCTP_PRIMITIVE_REQUESTHEARTBEAT,
103 SCTP_PRIMITIVE_ASCONF,
104 SCTP_PRIMITIVE_RECONF,
105 };
106
107 #define SCTP_EVENT_PRIMITIVE_MAX SCTP_PRIMITIVE_RECONF
108 #define SCTP_NUM_PRIMITIVE_TYPES (SCTP_EVENT_PRIMITIVE_MAX + 1)
109
110 /* We define here a utility type for manipulating subtypes.
111 * The subtype constructors all work like this:
112 *
113 * union sctp_subtype foo = SCTP_ST_CHUNK(SCTP_CID_INIT);
114 */
115
116 union sctp_subtype {
117 enum sctp_cid chunk;
118 enum sctp_event_timeout timeout;
119 enum sctp_event_other other;
120 enum sctp_event_primitive primitive;
121 };
122
123 #define SCTP_SUBTYPE_CONSTRUCTOR(_name, _type, _elt) \
124 static inline union sctp_subtype \
125 SCTP_ST_## _name (_type _arg) \
126 { union sctp_subtype _retval; _retval._elt = _arg; return _retval; }
127
128 SCTP_SUBTYPE_CONSTRUCTOR(CHUNK, enum sctp_cid, chunk)
129 SCTP_SUBTYPE_CONSTRUCTOR(TIMEOUT, enum sctp_event_timeout, timeout)
130 SCTP_SUBTYPE_CONSTRUCTOR(OTHER, enum sctp_event_other, other)
131 SCTP_SUBTYPE_CONSTRUCTOR(PRIMITIVE, enum sctp_event_primitive, primitive)
132
133
134 #define sctp_chunk_is_data(a) (a->chunk_hdr->type == SCTP_CID_DATA || \
135 a->chunk_hdr->type == SCTP_CID_I_DATA)
136
137 /* Internal error codes */
138 enum sctp_ierror {
139 SCTP_IERROR_NO_ERROR = 0,
140 SCTP_IERROR_BASE = 1000,
141 SCTP_IERROR_NO_COOKIE,
142 SCTP_IERROR_BAD_SIG,
143 SCTP_IERROR_STALE_COOKIE,
144 SCTP_IERROR_NOMEM,
145 SCTP_IERROR_MALFORMED,
146 SCTP_IERROR_BAD_TAG,
147 SCTP_IERROR_BIG_GAP,
148 SCTP_IERROR_DUP_TSN,
149 SCTP_IERROR_HIGH_TSN,
150 SCTP_IERROR_IGNORE_TSN,
151 SCTP_IERROR_NO_DATA,
152 SCTP_IERROR_BAD_STREAM,
153 SCTP_IERROR_BAD_PORTS,
154 SCTP_IERROR_AUTH_BAD_HMAC,
155 SCTP_IERROR_AUTH_BAD_KEYID,
156 SCTP_IERROR_PROTO_VIOLATION,
157 SCTP_IERROR_ERROR,
158 SCTP_IERROR_ABORT,
159 };
160
161
162
163 /* SCTP state defines for internal state machine */
164 enum sctp_state {
165
166 SCTP_STATE_CLOSED = 0,
167 SCTP_STATE_COOKIE_WAIT = 1,
168 SCTP_STATE_COOKIE_ECHOED = 2,
169 SCTP_STATE_ESTABLISHED = 3,
170 SCTP_STATE_SHUTDOWN_PENDING = 4,
171 SCTP_STATE_SHUTDOWN_SENT = 5,
172 SCTP_STATE_SHUTDOWN_RECEIVED = 6,
173 SCTP_STATE_SHUTDOWN_ACK_SENT = 7,
174
175 };
176
177 #define SCTP_STATE_MAX SCTP_STATE_SHUTDOWN_ACK_SENT
178 #define SCTP_STATE_NUM_STATES (SCTP_STATE_MAX + 1)
179
180 /* These are values for sk->state.
181 * For a UDP-style SCTP socket, the states are defined as follows
182 * - A socket in SCTP_SS_CLOSED state indicates that it is not willing to
183 * accept new associations, but it can initiate the creation of new ones.
184 * - A socket in SCTP_SS_LISTENING state indicates that it is willing to
185 * accept new associations and can initiate the creation of new ones.
186 * - A socket in SCTP_SS_ESTABLISHED state indicates that it is a peeled off
187 * socket with one association.
188 * For a TCP-style SCTP socket, the states are defined as follows
189 * - A socket in SCTP_SS_CLOSED state indicates that it is not willing to
190 * accept new associations, but it can initiate the creation of new ones.
191 * - A socket in SCTP_SS_LISTENING state indicates that it is willing to
192 * accept new associations, but cannot initiate the creation of new ones.
193 * - A socket in SCTP_SS_ESTABLISHED state indicates that it has a single
194 * association.
195 */
196 enum sctp_sock_state {
197 SCTP_SS_CLOSED = TCP_CLOSE,
198 SCTP_SS_LISTENING = TCP_LISTEN,
199 SCTP_SS_ESTABLISHING = TCP_SYN_SENT,
200 SCTP_SS_ESTABLISHED = TCP_ESTABLISHED,
201 SCTP_SS_CLOSING = TCP_CLOSE_WAIT,
202 };
203
204 enum sctp_plpmtud_state {
205 SCTP_PL_DISABLED,
206 SCTP_PL_BASE,
207 SCTP_PL_SEARCH,
208 SCTP_PL_COMPLETE,
209 SCTP_PL_ERROR,
210 };
211
212 #define SCTP_BASE_PLPMTU 1200
213 #define SCTP_MAX_PLPMTU 9000
214 #define SCTP_MIN_PLPMTU 512
215
216 #define SCTP_MAX_PROBES 3
217
218 #define SCTP_PL_BIG_STEP 32
219 #define SCTP_PL_MIN_STEP 4
220
221 /* These functions map various type to printable names. */
222 const char *sctp_cname(const union sctp_subtype id); /* chunk types */
223 const char *sctp_oname(const union sctp_subtype id); /* other events */
224 const char *sctp_tname(const union sctp_subtype id); /* timeouts */
225 const char *sctp_pname(const union sctp_subtype id); /* primitives */
226
227 /* This is a table of printable names of sctp_state_t's. */
228 extern const char *const sctp_state_tbl[];
229 extern const char *const sctp_evttype_tbl[];
230 extern const char *const sctp_status_tbl[];
231
232 /* Maximum chunk length considering padding requirements. */
233 enum { SCTP_MAX_CHUNK_LEN = ((1<<16) - sizeof(__u32)) };
234
235 /* Encourage Cookie-Echo bundling by pre-fragmenting chunks a little
236 * harder (until reaching ESTABLISHED state).
237 */
238 enum { SCTP_ARBITRARY_COOKIE_ECHO_LEN = 200 };
239
240 /* Guess at how big to make the TSN mapping array.
241 * We guarantee that we can handle at least this big a gap between the
242 * cumulative ACK and the highest TSN. In practice, we can often
243 * handle up to twice this value.
244 *
245 * NEVER make this more than 32767 (2^15-1). The Gap Ack Blocks in a
246 * SACK (see section 3.3.4) are only 16 bits, so 2*SCTP_TSN_MAP_SIZE
247 * must be less than 65535 (2^16 - 1), or we will have overflow
248 * problems creating SACK's.
249 */
250 #define SCTP_TSN_MAP_INITIAL BITS_PER_LONG
251 #define SCTP_TSN_MAP_INCREMENT SCTP_TSN_MAP_INITIAL
252 #define SCTP_TSN_MAP_SIZE 4096
253
254 /* We will not record more than this many duplicate TSNs between two
255 * SACKs. The minimum PMTU is 512. Remove all the headers and there
256 * is enough room for 117 duplicate reports. Round down to the
257 * nearest power of 2.
258 */
259 enum { SCTP_MAX_DUP_TSNS = 16 };
260 enum { SCTP_MAX_GABS = 16 };
261
262 /* Heartbeat interval - 30 secs */
263 #define SCTP_DEFAULT_TIMEOUT_HEARTBEAT (30*1000)
264
265 /* Delayed sack timer - 200ms */
266 #define SCTP_DEFAULT_TIMEOUT_SACK (200)
267
268 /* RTO.Initial - 3 seconds
269 * RTO.Min - 1 second
270 * RTO.Max - 60 seconds
271 * RTO.Alpha - 1/8
272 * RTO.Beta - 1/4
273 */
274 #define SCTP_RTO_INITIAL (3 * 1000)
275 #define SCTP_RTO_MIN (1 * 1000)
276 #define SCTP_RTO_MAX (60 * 1000)
277
278 #define SCTP_RTO_ALPHA 3 /* 1/8 when converted to right shifts. */
279 #define SCTP_RTO_BETA 2 /* 1/4 when converted to right shifts. */
280
281 /* Maximum number of new data packets that can be sent in a burst. */
282 #define SCTP_DEFAULT_MAX_BURST 4
283
284 #define SCTP_CLOCK_GRANULARITY 1 /* 1 jiffy */
285
286 #define SCTP_DEFAULT_COOKIE_LIFE (60 * 1000) /* 60 seconds */
287
288 #define SCTP_DEFAULT_MINWINDOW 1500 /* default minimum rwnd size */
289 #define SCTP_DEFAULT_MAXWINDOW 65535 /* default rwnd size */
290 #define SCTP_DEFAULT_RWND_SHIFT 4 /* by default, update on 1/16 of
291 * rcvbuf, which is 1/8 of initial
292 * window
293 */
294 #define SCTP_DEFAULT_MAXSEGMENT 1500 /* MTU size, this is the limit
295 * to which we will raise the P-MTU.
296 */
297 #define SCTP_DEFAULT_MINSEGMENT 512 /* MTU size ... if no mtu disc */
298
299 #define SCTP_SECRET_SIZE 32 /* Number of octets in a 256 bits. */
300
301 #define SCTP_SIGNATURE_SIZE 20 /* size of a SLA-1 signature */
302
303 #define SCTP_COOKIE_MULTIPLE 32 /* Pad out our cookie to make our hash
304 * functions simpler to write.
305 */
306
307 #define SCTP_DEFAULT_UDP_PORT 9899 /* default UDP tunneling port */
308
309 /* These are the values for pf exposure, UNUSED is to keep compatible with old
310 * applications by default.
311 */
312 enum {
313 SCTP_PF_EXPOSE_UNSET,
314 SCTP_PF_EXPOSE_DISABLE,
315 SCTP_PF_EXPOSE_ENABLE,
316 };
317 #define SCTP_PF_EXPOSE_MAX SCTP_PF_EXPOSE_ENABLE
318
319 #define SCTP_PS_RETRANS_MAX 0xffff
320
321 /* These return values describe the success or failure of a number of
322 * routines which form the lower interface to SCTP_outqueue.
323 */
324 enum sctp_xmit {
325 SCTP_XMIT_OK,
326 SCTP_XMIT_PMTU_FULL,
327 SCTP_XMIT_RWND_FULL,
328 SCTP_XMIT_DELAY,
329 };
330
331 /* These are the commands for manipulating transports. */
332 enum sctp_transport_cmd {
333 SCTP_TRANSPORT_UP,
334 SCTP_TRANSPORT_DOWN,
335 SCTP_TRANSPORT_PF,
336 };
337
338 /* These are the address scopes defined mainly for IPv4 addresses
339 * based on draft of SCTP IPv4 scoping <draft-stewart-tsvwg-sctp-ipv4-00.txt>.
340 * These scopes are hopefully generic enough to be used on scoping both
341 * IPv4 and IPv6 addresses in SCTP.
342 * At this point, the IPv6 scopes will be mapped to these internal scopes
343 * as much as possible.
344 */
345 enum sctp_scope {
346 SCTP_SCOPE_GLOBAL, /* IPv4 global addresses */
347 SCTP_SCOPE_PRIVATE, /* IPv4 private addresses */
348 SCTP_SCOPE_LINK, /* IPv4 link local address */
349 SCTP_SCOPE_LOOPBACK, /* IPv4 loopback address */
350 SCTP_SCOPE_UNUSABLE, /* IPv4 unusable addresses */
351 };
352
353 enum {
354 SCTP_SCOPE_POLICY_DISABLE, /* Disable IPv4 address scoping */
355 SCTP_SCOPE_POLICY_ENABLE, /* Enable IPv4 address scoping */
356 SCTP_SCOPE_POLICY_PRIVATE, /* Follow draft but allow IPv4 private addresses */
357 SCTP_SCOPE_POLICY_LINK, /* Follow draft but allow IPv4 link local addresses */
358 };
359
360 #define SCTP_SCOPE_POLICY_MAX SCTP_SCOPE_POLICY_LINK
361
362 /* Based on IPv4 scoping <draft-stewart-tsvwg-sctp-ipv4-00.txt>,
363 * SCTP IPv4 unusable addresses: 0.0.0.0/8, 224.0.0.0/4, 192.88.99.0/24.
364 * Also, RFC 8.4, non-unicast addresses are not considered valid SCTP
365 * addresses.
366 */
367 #define IS_IPV4_UNUSABLE_ADDRESS(a) \
368 ((htonl(INADDR_BROADCAST) == a) || \
369 ipv4_is_multicast(a) || \
370 ipv4_is_zeronet(a) || \
371 ipv4_is_anycast_6to4(a))
372
373 /* Flags used for the bind address copy functions. */
374 #define SCTP_ADDR4_ALLOWED 0x00000001 /* IPv4 address is allowed by
375 local sock family */
376 #define SCTP_ADDR6_ALLOWED 0x00000002 /* IPv6 address is allowed by
377 local sock family */
378 #define SCTP_ADDR4_PEERSUPP 0x00000004 /* IPv4 address is supported by
379 peer */
380 #define SCTP_ADDR6_PEERSUPP 0x00000008 /* IPv6 address is supported by
381 peer */
382
383 /* Reasons to retransmit. */
384 enum sctp_retransmit_reason {
385 SCTP_RTXR_T3_RTX,
386 SCTP_RTXR_FAST_RTX,
387 SCTP_RTXR_PMTUD,
388 SCTP_RTXR_T1_RTX,
389 };
390
391 /* Reasons to lower cwnd. */
392 enum sctp_lower_cwnd {
393 SCTP_LOWER_CWND_T3_RTX,
394 SCTP_LOWER_CWND_FAST_RTX,
395 SCTP_LOWER_CWND_ECNE,
396 SCTP_LOWER_CWND_INACTIVE,
397 };
398
399
400 /* SCTP-AUTH Necessary constants */
401
402 /* SCTP-AUTH, Section 3.3
403 *
404 * The following Table 2 shows the currently defined values for HMAC
405 * identifiers.
406 *
407 * +-----------------+--------------------------+
408 * | HMAC Identifier | Message Digest Algorithm |
409 * +-----------------+--------------------------+
410 * | 0 | Reserved |
411 * | 1 | SHA-1 defined in [8] |
412 * | 2 | Reserved |
413 * | 3 | SHA-256 defined in [8] |
414 * +-----------------+--------------------------+
415 */
416 enum {
417 SCTP_AUTH_HMAC_ID_RESERVED_0,
418 SCTP_AUTH_HMAC_ID_SHA1,
419 SCTP_AUTH_HMAC_ID_RESERVED_2,
420 #if defined (CONFIG_CRYPTO_SHA256) || defined (CONFIG_CRYPTO_SHA256_MODULE)
421 SCTP_AUTH_HMAC_ID_SHA256,
422 #endif
423 __SCTP_AUTH_HMAC_MAX
424 };
425
426 #define SCTP_AUTH_HMAC_ID_MAX __SCTP_AUTH_HMAC_MAX - 1
427 #define SCTP_AUTH_NUM_HMACS __SCTP_AUTH_HMAC_MAX
428 #define SCTP_SHA1_SIG_SIZE 20
429 #define SCTP_SHA256_SIG_SIZE 32
430
431 /* SCTP-AUTH, Section 3.2
432 * The chunk types for INIT, INIT-ACK, SHUTDOWN-COMPLETE and AUTH chunks
433 * MUST NOT be listed in the CHUNKS parameter
434 */
435 #define SCTP_NUM_NOAUTH_CHUNKS 4
436 #define SCTP_AUTH_MAX_CHUNKS (SCTP_NUM_CHUNK_TYPES - SCTP_NUM_NOAUTH_CHUNKS)
437
438 /* SCTP-AUTH Section 6.1
439 * The RANDOM parameter MUST contain a 32 byte random number.
440 */
441 #define SCTP_AUTH_RANDOM_LENGTH 32
442
443 #define SCTP_PROBE_TIMER_MIN 5000
444
445 #endif /* __sctp_constants_h__ */
446
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