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_SACK,
81 SCTP_EVENT_TIMEOUT_AUTOCLOSE,
82 };
83
84 #define SCTP_EVENT_TIMEOUT_MAX SCTP_EVENT_TIMEOUT_AUTOCLOSE
85 #define SCTP_NUM_TIMEOUT_TYPES (SCTP_EVENT_TIMEOUT_MAX + 1)
86
87 enum sctp_event_other {
88 SCTP_EVENT_NO_PENDING_TSN = 0,
89 SCTP_EVENT_ICMP_PROTO_UNREACH,
90 };
91
92 #define SCTP_EVENT_OTHER_MAX SCTP_EVENT_ICMP_PROTO_UNREACH
93 #define SCTP_NUM_OTHER_TYPES (SCTP_EVENT_OTHER_MAX + 1)
94
95 /* These are primitive requests from the ULP. */
96 enum sctp_event_primitive {
97 SCTP_PRIMITIVE_ASSOCIATE = 0,
98 SCTP_PRIMITIVE_SHUTDOWN,
99 SCTP_PRIMITIVE_ABORT,
100 SCTP_PRIMITIVE_SEND,
101 SCTP_PRIMITIVE_REQUESTHEARTBEAT,
102 SCTP_PRIMITIVE_ASCONF,
103 SCTP_PRIMITIVE_RECONF,
104 };
105
106 #define SCTP_EVENT_PRIMITIVE_MAX SCTP_PRIMITIVE_RECONF
107 #define SCTP_NUM_PRIMITIVE_TYPES (SCTP_EVENT_PRIMITIVE_MAX + 1)
108
109 /* We define here a utility type for manipulating subtypes.
110 * The subtype constructors all work like this:
111 *
112 * union sctp_subtype foo = SCTP_ST_CHUNK(SCTP_CID_INIT);
113 */
114
115 union sctp_subtype {
116 enum sctp_cid chunk;
117 enum sctp_event_timeout timeout;
118 enum sctp_event_other other;
119 enum sctp_event_primitive primitive;
120 };
121
122 #define SCTP_SUBTYPE_CONSTRUCTOR(_name, _type, _elt) \
123 static inline union sctp_subtype \
124 SCTP_ST_## _name (_type _arg) \
125 { union sctp_subtype _retval; _retval._elt = _arg; return _retval; }
126
127 SCTP_SUBTYPE_CONSTRUCTOR(CHUNK, enum sctp_cid, chunk)
128 SCTP_SUBTYPE_CONSTRUCTOR(TIMEOUT, enum sctp_event_timeout, timeout)
129 SCTP_SUBTYPE_CONSTRUCTOR(OTHER, enum sctp_event_other, other)
130 SCTP_SUBTYPE_CONSTRUCTOR(PRIMITIVE, enum sctp_event_primitive, primitive)
131
132
133 #define sctp_chunk_is_data(a) (a->chunk_hdr->type == SCTP_CID_DATA || \
134 a->chunk_hdr->type == SCTP_CID_I_DATA)
135
136 /* Internal error codes */
137 enum sctp_ierror {
138 SCTP_IERROR_NO_ERROR = 0,
139 SCTP_IERROR_BASE = 1000,
140 SCTP_IERROR_NO_COOKIE,
141 SCTP_IERROR_BAD_SIG,
142 SCTP_IERROR_STALE_COOKIE,
143 SCTP_IERROR_NOMEM,
144 SCTP_IERROR_MALFORMED,
145 SCTP_IERROR_BAD_TAG,
146 SCTP_IERROR_BIG_GAP,
147 SCTP_IERROR_DUP_TSN,
148 SCTP_IERROR_HIGH_TSN,
149 SCTP_IERROR_IGNORE_TSN,
150 SCTP_IERROR_NO_DATA,
151 SCTP_IERROR_BAD_STREAM,
152 SCTP_IERROR_BAD_PORTS,
153 SCTP_IERROR_AUTH_BAD_HMAC,
154 SCTP_IERROR_AUTH_BAD_KEYID,
155 SCTP_IERROR_PROTO_VIOLATION,
156 SCTP_IERROR_ERROR,
157 SCTP_IERROR_ABORT,
158 };
159
160
161
162 /* SCTP state defines for internal state machine */
163 enum sctp_state {
164
165 SCTP_STATE_CLOSED = 0,
166 SCTP_STATE_COOKIE_WAIT = 1,
167 SCTP_STATE_COOKIE_ECHOED = 2,
168 SCTP_STATE_ESTABLISHED = 3,
169 SCTP_STATE_SHUTDOWN_PENDING = 4,
170 SCTP_STATE_SHUTDOWN_SENT = 5,
171 SCTP_STATE_SHUTDOWN_RECEIVED = 6,
172 SCTP_STATE_SHUTDOWN_ACK_SENT = 7,
173
174 };
175
176 #define SCTP_STATE_MAX SCTP_STATE_SHUTDOWN_ACK_SENT
177 #define SCTP_STATE_NUM_STATES (SCTP_STATE_MAX + 1)
178
179 /* These are values for sk->state.
180 * For a UDP-style SCTP socket, the states are defined as follows
181 * - A socket in SCTP_SS_CLOSED state indicates that it is not willing to
182 * accept new associations, but it can initiate the creation of new ones.
183 * - A socket in SCTP_SS_LISTENING state indicates that it is willing to
184 * accept new associations and can initiate the creation of new ones.
185 * - A socket in SCTP_SS_ESTABLISHED state indicates that it is a peeled off
186 * socket with one association.
187 * For a TCP-style SCTP socket, the states are defined as follows
188 * - A socket in SCTP_SS_CLOSED state indicates that it is not willing to
189 * accept new associations, but it can initiate the creation of new ones.
190 * - A socket in SCTP_SS_LISTENING state indicates that it is willing to
191 * accept new associations, but cannot initiate the creation of new ones.
192 * - A socket in SCTP_SS_ESTABLISHED state indicates that it has a single
193 * association.
194 */
195 enum sctp_sock_state {
196 SCTP_SS_CLOSED = TCP_CLOSE,
197 SCTP_SS_LISTENING = TCP_LISTEN,
198 SCTP_SS_ESTABLISHING = TCP_SYN_SENT,
199 SCTP_SS_ESTABLISHED = TCP_ESTABLISHED,
200 SCTP_SS_CLOSING = TCP_CLOSE_WAIT,
201 };
202
203 /* These functions map various type to printable names. */
204 const char *sctp_cname(const union sctp_subtype id); /* chunk types */
205 const char *sctp_oname(const union sctp_subtype id); /* other events */
206 const char *sctp_tname(const union sctp_subtype id); /* timeouts */
207 const char *sctp_pname(const union sctp_subtype id); /* primitives */
208
209 /* This is a table of printable names of sctp_state_t's. */
210 extern const char *const sctp_state_tbl[];
211 extern const char *const sctp_evttype_tbl[];
212 extern const char *const sctp_status_tbl[];
213
214 /* Maximum chunk length considering padding requirements. */
215 enum { SCTP_MAX_CHUNK_LEN = ((1<<16) - sizeof(__u32)) };
216
217 /* Encourage Cookie-Echo bundling by pre-fragmenting chunks a little
218 * harder (until reaching ESTABLISHED state).
219 */
220 enum { SCTP_ARBITRARY_COOKIE_ECHO_LEN = 200 };
221
222 /* Guess at how big to make the TSN mapping array.
223 * We guarantee that we can handle at least this big a gap between the
224 * cumulative ACK and the highest TSN. In practice, we can often
225 * handle up to twice this value.
226 *
227 * NEVER make this more than 32767 (2^15-1). The Gap Ack Blocks in a
228 * SACK (see section 3.3.4) are only 16 bits, so 2*SCTP_TSN_MAP_SIZE
229 * must be less than 65535 (2^16 - 1), or we will have overflow
230 * problems creating SACK's.
231 */
232 #define SCTP_TSN_MAP_INITIAL BITS_PER_LONG
233 #define SCTP_TSN_MAP_INCREMENT SCTP_TSN_MAP_INITIAL
234 #define SCTP_TSN_MAP_SIZE 4096
235
236 /* We will not record more than this many duplicate TSNs between two
237 * SACKs. The minimum PMTU is 512. Remove all the headers and there
238 * is enough room for 117 duplicate reports. Round down to the
239 * nearest power of 2.
240 */
241 enum { SCTP_MAX_DUP_TSNS = 16 };
242 enum { SCTP_MAX_GABS = 16 };
243
244 /* Heartbeat interval - 30 secs */
245 #define SCTP_DEFAULT_TIMEOUT_HEARTBEAT (30*1000)
246
247 /* Delayed sack timer - 200ms */
248 #define SCTP_DEFAULT_TIMEOUT_SACK (200)
249
250 /* RTO.Initial - 3 seconds
251 * RTO.Min - 1 second
252 * RTO.Max - 60 seconds
253 * RTO.Alpha - 1/8
254 * RTO.Beta - 1/4
255 */
256 #define SCTP_RTO_INITIAL (3 * 1000)
257 #define SCTP_RTO_MIN (1 * 1000)
258 #define SCTP_RTO_MAX (60 * 1000)
259
260 #define SCTP_RTO_ALPHA 3 /* 1/8 when converted to right shifts. */
261 #define SCTP_RTO_BETA 2 /* 1/4 when converted to right shifts. */
262
263 /* Maximum number of new data packets that can be sent in a burst. */
264 #define SCTP_DEFAULT_MAX_BURST 4
265
266 #define SCTP_CLOCK_GRANULARITY 1 /* 1 jiffy */
267
268 #define SCTP_DEFAULT_COOKIE_LIFE (60 * 1000) /* 60 seconds */
269
270 #define SCTP_DEFAULT_MINWINDOW 1500 /* default minimum rwnd size */
271 #define SCTP_DEFAULT_MAXWINDOW 65535 /* default rwnd size */
272 #define SCTP_DEFAULT_RWND_SHIFT 4 /* by default, update on 1/16 of
273 * rcvbuf, which is 1/8 of initial
274 * window
275 */
276 #define SCTP_DEFAULT_MAXSEGMENT 1500 /* MTU size, this is the limit
277 * to which we will raise the P-MTU.
278 */
279 #define SCTP_DEFAULT_MINSEGMENT 512 /* MTU size ... if no mtu disc */
280
281 #define SCTP_SECRET_SIZE 32 /* Number of octets in a 256 bits. */
282
283 #define SCTP_SIGNATURE_SIZE 20 /* size of a SLA-1 signature */
284
285 #define SCTP_COOKIE_MULTIPLE 32 /* Pad out our cookie to make our hash
286 * functions simpler to write.
287 */
288
289 /* These return values describe the success or failure of a number of
290 * routines which form the lower interface to SCTP_outqueue.
291 */
292 enum sctp_xmit {
293 SCTP_XMIT_OK,
294 SCTP_XMIT_PMTU_FULL,
295 SCTP_XMIT_RWND_FULL,
296 SCTP_XMIT_DELAY,
297 };
298
299 /* These are the commands for manipulating transports. */
300 enum sctp_transport_cmd {
301 SCTP_TRANSPORT_UP,
302 SCTP_TRANSPORT_DOWN,
303 SCTP_TRANSPORT_PF,
304 };
305
306 /* These are the address scopes defined mainly for IPv4 addresses
307 * based on draft of SCTP IPv4 scoping <draft-stewart-tsvwg-sctp-ipv4-00.txt>.
308 * These scopes are hopefully generic enough to be used on scoping both
309 * IPv4 and IPv6 addresses in SCTP.
310 * At this point, the IPv6 scopes will be mapped to these internal scopes
311 * as much as possible.
312 */
313 enum sctp_scope {
314 SCTP_SCOPE_GLOBAL, /* IPv4 global addresses */
315 SCTP_SCOPE_PRIVATE, /* IPv4 private addresses */
316 SCTP_SCOPE_LINK, /* IPv4 link local address */
317 SCTP_SCOPE_LOOPBACK, /* IPv4 loopback address */
318 SCTP_SCOPE_UNUSABLE, /* IPv4 unusable addresses */
319 };
320
321 enum {
322 SCTP_SCOPE_POLICY_DISABLE, /* Disable IPv4 address scoping */
323 SCTP_SCOPE_POLICY_ENABLE, /* Enable IPv4 address scoping */
324 SCTP_SCOPE_POLICY_PRIVATE, /* Follow draft but allow IPv4 private addresses */
325 SCTP_SCOPE_POLICY_LINK, /* Follow draft but allow IPv4 link local addresses */
326 };
327
328 #define SCTP_SCOPE_POLICY_MAX SCTP_SCOPE_POLICY_LINK
329
330 /* Based on IPv4 scoping <draft-stewart-tsvwg-sctp-ipv4-00.txt>,
331 * SCTP IPv4 unusable addresses: 0.0.0.0/8, 224.0.0.0/4, 198.18.0.0/24,
332 * 192.88.99.0/24.
333 * Also, RFC 8.4, non-unicast addresses are not considered valid SCTP
334 * addresses.
335 */
336 #define IS_IPV4_UNUSABLE_ADDRESS(a) \
337 ((htonl(INADDR_BROADCAST) == a) || \
338 ipv4_is_multicast(a) || \
339 ipv4_is_zeronet(a) || \
340 ipv4_is_test_198(a) || \
341 ipv4_is_anycast_6to4(a))
342
343 /* Flags used for the bind address copy functions. */
344 #define SCTP_ADDR6_ALLOWED 0x00000001 /* IPv6 address is allowed by
345 local sock family */
346 #define SCTP_ADDR4_PEERSUPP 0x00000002 /* IPv4 address is supported by
347 peer */
348 #define SCTP_ADDR6_PEERSUPP 0x00000004 /* IPv6 address is supported by
349 peer */
350
351 /* Reasons to retransmit. */
352 enum sctp_retransmit_reason {
353 SCTP_RTXR_T3_RTX,
354 SCTP_RTXR_FAST_RTX,
355 SCTP_RTXR_PMTUD,
356 SCTP_RTXR_T1_RTX,
357 };
358
359 /* Reasons to lower cwnd. */
360 enum sctp_lower_cwnd {
361 SCTP_LOWER_CWND_T3_RTX,
362 SCTP_LOWER_CWND_FAST_RTX,
363 SCTP_LOWER_CWND_ECNE,
364 SCTP_LOWER_CWND_INACTIVE,
365 };
366
367
368 /* SCTP-AUTH Necessary constants */
369
370 /* SCTP-AUTH, Section 3.3
371 *
372 * The following Table 2 shows the currently defined values for HMAC
373 * identifiers.
374 *
375 * +-----------------+--------------------------+
376 * | HMAC Identifier | Message Digest Algorithm |
377 * +-----------------+--------------------------+
378 * | 0 | Reserved |
379 * | 1 | SHA-1 defined in [8] |
380 * | 2 | Reserved |
381 * | 3 | SHA-256 defined in [8] |
382 * +-----------------+--------------------------+
383 */
384 enum {
385 SCTP_AUTH_HMAC_ID_RESERVED_0,
386 SCTP_AUTH_HMAC_ID_SHA1,
387 SCTP_AUTH_HMAC_ID_RESERVED_2,
388 #if defined (CONFIG_CRYPTO_SHA256) || defined (CONFIG_CRYPTO_SHA256_MODULE)
389 SCTP_AUTH_HMAC_ID_SHA256,
390 #endif
391 __SCTP_AUTH_HMAC_MAX
392 };
393
394 #define SCTP_AUTH_HMAC_ID_MAX __SCTP_AUTH_HMAC_MAX - 1
395 #define SCTP_AUTH_NUM_HMACS __SCTP_AUTH_HMAC_MAX
396 #define SCTP_SHA1_SIG_SIZE 20
397 #define SCTP_SHA256_SIG_SIZE 32
398
399 /* SCTP-AUTH, Section 3.2
400 * The chunk types for INIT, INIT-ACK, SHUTDOWN-COMPLETE and AUTH chunks
401 * MUST NOT be listed in the CHUNKS parameter
402 */
403 #define SCTP_NUM_NOAUTH_CHUNKS 4
404 #define SCTP_AUTH_MAX_CHUNKS (SCTP_NUM_CHUNK_TYPES - SCTP_NUM_NOAUTH_CHUNKS)
405
406 /* SCTP-AUTH Section 6.1
407 * The RANDOM parameter MUST contain a 32 byte random number.
408 */
409 #define SCTP_AUTH_RANDOM_LENGTH 32
410
411 #endif /* __sctp_constants_h__ */