1 /* SCTP kernel implementation
2  * (C) Copyright IBM Corp. 2001, 2004
3  * Copyright (c) 1999-2000 Cisco, Inc.
4  * Copyright (c) 1999-2001 Motorola, Inc.
5  * Copyright (c) 2001 Intel Corp.
6  *
7  * This file is part of the SCTP kernel implementation
8  *
9  * This SCTP implementation is free software;
10  * you can redistribute it and/or modify it under the terms of
11  * the GNU General Public License as published by
12  * the Free Software Foundation; either version 2, or (at your option)
13  * any later version.
14  *
15  * This SCTP implementation is distributed in the hope that it
16  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
17  *                 ************************
18  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
19  * See the GNU General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with GNU CC; see the file COPYING.  If not, write to
23  * the Free Software Foundation, 59 Temple Place - Suite 330,
24  * Boston, MA 02111-1307, USA.
25  *
26  * Please send any bug reports or fixes you make to the
27  * email address(es):
28  *    lksctp developers <lksctp-developers@lists.sourceforge.net>
29  *
30  * Or submit a bug report through the following website:
31  *    http://www.sf.net/projects/lksctp
32  *
33  * Written or modified by:
34  *   La Monte H.P. Yarroll <piggy@acm.org>
35  *   Karl Knutson          <karl@athena.chicago.il.us>
36  *   Randall Stewart       <randall@stewart.chicago.il.us>
37  *   Ken Morneau           <kmorneau@cisco.com>
38  *   Qiaobing Xie          <qxie1@motorola.com>
39  *   Xingang Guo           <xingang.guo@intel.com>
40  *   Sridhar Samudrala     <samudrala@us.ibm.com>
41  *   Daisy Chang           <daisyc@us.ibm.com>
42  *
43  * Any bugs reported given to us we will try to fix... any fixes shared will
44  * be incorporated into the next SCTP release.
45  */
46 
47 #ifndef __sctp_constants_h__
48 #define __sctp_constants_h__
49 
50 #include <linux/sctp.h>
51 #include <linux/ipv6.h> /* For ipv6hdr. */
52 #include <net/sctp/user.h>
53 #include <net/tcp_states.h>  /* For TCP states used in sctp_sock_state_t */
54 
55 /* Value used for stream negotiation. */
56 enum { SCTP_MAX_STREAM = 0xffff };
57 enum { SCTP_DEFAULT_OUTSTREAMS = 10 };
58 enum { SCTP_DEFAULT_INSTREAMS = SCTP_MAX_STREAM };
59 
60 /* Since CIDs are sparse, we need all four of the following
61  * symbols.  CIDs are dense through SCTP_CID_BASE_MAX.
62  */
63 #define SCTP_CID_BASE_MAX		SCTP_CID_SHUTDOWN_COMPLETE
64 
65 #define SCTP_NUM_BASE_CHUNK_TYPES	(SCTP_CID_BASE_MAX + 1)
66 
67 #define SCTP_NUM_ADDIP_CHUNK_TYPES	2
68 
69 #define SCTP_NUM_PRSCTP_CHUNK_TYPES	1
70 
71 #define SCTP_NUM_AUTH_CHUNK_TYPES	1
72 
73 #define SCTP_NUM_CHUNK_TYPES		(SCTP_NUM_BASE_CHUNK_TYPES + \
74 					 SCTP_NUM_ADDIP_CHUNK_TYPES +\
75 					 SCTP_NUM_PRSCTP_CHUNK_TYPES +\
76 					 SCTP_NUM_AUTH_CHUNK_TYPES)
77 
78 /* These are the different flavours of event.  */
79 typedef enum {
80 
81 	SCTP_EVENT_T_CHUNK = 1,
82 	SCTP_EVENT_T_TIMEOUT,
83 	SCTP_EVENT_T_OTHER,
84 	SCTP_EVENT_T_PRIMITIVE
85 
86 } sctp_event_t;
87 
88 /* As a convenience for the state machine, we append SCTP_EVENT_* and
89  * SCTP_ULP_* to the list of possible chunks.
90  */
91 
92 typedef enum {
93 	SCTP_EVENT_TIMEOUT_NONE = 0,
94 	SCTP_EVENT_TIMEOUT_T1_COOKIE,
95 	SCTP_EVENT_TIMEOUT_T1_INIT,
96 	SCTP_EVENT_TIMEOUT_T2_SHUTDOWN,
97 	SCTP_EVENT_TIMEOUT_T3_RTX,
98 	SCTP_EVENT_TIMEOUT_T4_RTO,
99 	SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD,
100 	SCTP_EVENT_TIMEOUT_HEARTBEAT,
101 	SCTP_EVENT_TIMEOUT_SACK,
102 	SCTP_EVENT_TIMEOUT_AUTOCLOSE,
103 } sctp_event_timeout_t;
104 
105 #define SCTP_EVENT_TIMEOUT_MAX		SCTP_EVENT_TIMEOUT_AUTOCLOSE
106 #define SCTP_NUM_TIMEOUT_TYPES		(SCTP_EVENT_TIMEOUT_MAX + 1)
107 
108 typedef enum {
109 	SCTP_EVENT_NO_PENDING_TSN = 0,
110 	SCTP_EVENT_ICMP_PROTO_UNREACH,
111 } sctp_event_other_t;
112 
113 #define SCTP_EVENT_OTHER_MAX		SCTP_EVENT_ICMP_PROTO_UNREACH
114 #define SCTP_NUM_OTHER_TYPES		(SCTP_EVENT_OTHER_MAX + 1)
115 
116 /* These are primitive requests from the ULP.  */
117 typedef enum {
118 	SCTP_PRIMITIVE_ASSOCIATE = 0,
119 	SCTP_PRIMITIVE_SHUTDOWN,
120 	SCTP_PRIMITIVE_ABORT,
121 	SCTP_PRIMITIVE_SEND,
122 	SCTP_PRIMITIVE_REQUESTHEARTBEAT,
123 	SCTP_PRIMITIVE_ASCONF,
124 } sctp_event_primitive_t;
125 
126 #define SCTP_EVENT_PRIMITIVE_MAX	SCTP_PRIMITIVE_ASCONF
127 #define SCTP_NUM_PRIMITIVE_TYPES	(SCTP_EVENT_PRIMITIVE_MAX + 1)
128 
129 /* We define here a utility type for manipulating subtypes.
130  * The subtype constructors all work like this:
131  *
132  * 	sctp_subtype_t foo = SCTP_ST_CHUNK(SCTP_CID_INIT);
133  */
134 
135 typedef union {
136 	sctp_cid_t chunk;
137 	sctp_event_timeout_t timeout;
138 	sctp_event_other_t other;
139 	sctp_event_primitive_t primitive;
140 } sctp_subtype_t;
141 
142 #define SCTP_SUBTYPE_CONSTRUCTOR(_name, _type, _elt) \
143 static inline sctp_subtype_t	\
144 SCTP_ST_## _name (_type _arg)		\
145 { sctp_subtype_t _retval; _retval._elt = _arg; return _retval; }
146 
147 SCTP_SUBTYPE_CONSTRUCTOR(CHUNK,		sctp_cid_t,		chunk)
148 SCTP_SUBTYPE_CONSTRUCTOR(TIMEOUT,	sctp_event_timeout_t,	timeout)
149 SCTP_SUBTYPE_CONSTRUCTOR(OTHER,		sctp_event_other_t,	other)
150 SCTP_SUBTYPE_CONSTRUCTOR(PRIMITIVE,	sctp_event_primitive_t,	primitive)
151 
152 
153 #define sctp_chunk_is_data(a) (a->chunk_hdr->type == SCTP_CID_DATA)
154 
155 /* Calculate the actual data size in a data chunk */
156 #define SCTP_DATA_SNDSIZE(c) ((int)((unsigned long)(c->chunk_end)\
157 		       		- (unsigned long)(c->chunk_hdr)\
158 				- sizeof(sctp_data_chunk_t)))
159 
160 /* Internal error codes */
161 typedef enum {
162 
163 	SCTP_IERROR_NO_ERROR	        = 0,
164 	SCTP_IERROR_BASE		= 1000,
165 	SCTP_IERROR_NO_COOKIE,
166 	SCTP_IERROR_BAD_SIG,
167 	SCTP_IERROR_STALE_COOKIE,
168 	SCTP_IERROR_NOMEM,
169 	SCTP_IERROR_MALFORMED,
170 	SCTP_IERROR_BAD_TAG,
171 	SCTP_IERROR_BIG_GAP,
172 	SCTP_IERROR_DUP_TSN,
173 	SCTP_IERROR_HIGH_TSN,
174 	SCTP_IERROR_IGNORE_TSN,
175 	SCTP_IERROR_NO_DATA,
176 	SCTP_IERROR_BAD_STREAM,
177 	SCTP_IERROR_BAD_PORTS,
178 	SCTP_IERROR_AUTH_BAD_HMAC,
179 	SCTP_IERROR_AUTH_BAD_KEYID,
180 	SCTP_IERROR_PROTO_VIOLATION,
181 	SCTP_IERROR_ERROR,
182 	SCTP_IERROR_ABORT,
183 } sctp_ierror_t;
184 
185 
186 
187 /* SCTP state defines for internal state machine */
188 typedef enum {
189 
190 	SCTP_STATE_CLOSED		= 0,
191 	SCTP_STATE_COOKIE_WAIT		= 1,
192 	SCTP_STATE_COOKIE_ECHOED	= 2,
193 	SCTP_STATE_ESTABLISHED		= 3,
194 	SCTP_STATE_SHUTDOWN_PENDING	= 4,
195 	SCTP_STATE_SHUTDOWN_SENT	= 5,
196 	SCTP_STATE_SHUTDOWN_RECEIVED	= 6,
197 	SCTP_STATE_SHUTDOWN_ACK_SENT	= 7,
198 
199 } sctp_state_t;
200 
201 #define SCTP_STATE_MAX			SCTP_STATE_SHUTDOWN_ACK_SENT
202 #define SCTP_STATE_NUM_STATES		(SCTP_STATE_MAX + 1)
203 
204 /* These are values for sk->state.
205  * For a UDP-style SCTP socket, the states are defined as follows
206  * - A socket in SCTP_SS_CLOSED state indicates that it is not willing to
207  *   accept new associations, but it can initiate the creation of new ones.
208  * - A socket in SCTP_SS_LISTENING state indicates that it is willing to
209  *   accept new  associations and can initiate the creation of new ones.
210  * - A socket in SCTP_SS_ESTABLISHED state indicates that it is a peeled off
211  *   socket with one association.
212  * For a TCP-style SCTP socket, the states are defined as follows
213  * - A socket in SCTP_SS_CLOSED state indicates that it is not willing to
214  *   accept new associations, but it can initiate the creation of new ones.
215  * - A socket in SCTP_SS_LISTENING state indicates that it is willing to
216  *   accept new associations, but cannot initiate the creation of new ones.
217  * - A socket in SCTP_SS_ESTABLISHED state indicates that it has a single
218  *   association.
219  */
220 typedef enum {
221 	SCTP_SS_CLOSED         = TCP_CLOSE,
222 	SCTP_SS_LISTENING      = TCP_LISTEN,
223 	SCTP_SS_ESTABLISHING   = TCP_SYN_SENT,
224 	SCTP_SS_ESTABLISHED    = TCP_ESTABLISHED,
225 	SCTP_SS_CLOSING        = TCP_CLOSING,
226 } sctp_sock_state_t;
227 
228 /* These functions map various type to printable names.  */
229 const char *sctp_cname(const sctp_subtype_t);	/* chunk types */
230 const char *sctp_oname(const sctp_subtype_t);	/* other events */
231 const char *sctp_tname(const sctp_subtype_t);	/* timeouts */
232 const char *sctp_pname(const sctp_subtype_t);	/* primitives */
233 
234 /* This is a table of printable names of sctp_state_t's.  */
235 extern const char *const sctp_state_tbl[];
236 extern const char *const sctp_evttype_tbl[];
237 extern const char *const sctp_status_tbl[];
238 
239 /* Maximum chunk length considering padding requirements. */
240 enum { SCTP_MAX_CHUNK_LEN = ((1<<16) - sizeof(__u32)) };
241 
242 /* Encourage Cookie-Echo bundling by pre-fragmenting chunks a little
243  * harder (until reaching ESTABLISHED state).
244  */
245 enum { SCTP_ARBITRARY_COOKIE_ECHO_LEN = 200 };
246 
247 /* Guess at how big to make the TSN mapping array.
248  * We guarantee that we can handle at least this big a gap between the
249  * cumulative ACK and the highest TSN.  In practice, we can often
250  * handle up to twice this value.
251  *
252  * NEVER make this more than 32767 (2^15-1).  The Gap Ack Blocks in a
253  * SACK (see  section 3.3.4) are only 16 bits, so 2*SCTP_TSN_MAP_SIZE
254  * must be less than 65535 (2^16 - 1), or we will have overflow
255  * problems creating SACK's.
256  */
257 #define SCTP_TSN_MAP_INITIAL BITS_PER_LONG
258 #define SCTP_TSN_MAP_INCREMENT SCTP_TSN_MAP_INITIAL
259 #define SCTP_TSN_MAP_SIZE 4096
260 
261 /* We will not record more than this many duplicate TSNs between two
262  * SACKs.  The minimum PMTU is 576.  Remove all the headers and there
263  * is enough room for 131 duplicate reports.  Round down to the
264  * nearest power of 2.
265  */
266 enum { SCTP_MIN_PMTU = 576 };
267 enum { SCTP_MAX_DUP_TSNS = 16 };
268 enum { SCTP_MAX_GABS = 16 };
269 
270 /* Heartbeat interval - 30 secs */
271 #define SCTP_DEFAULT_TIMEOUT_HEARTBEAT	(30*1000)
272 
273 /* Delayed sack timer - 200ms */
274 #define SCTP_DEFAULT_TIMEOUT_SACK	(200)
275 
276 /* RTO.Initial              - 3  seconds
277  * RTO.Min                  - 1  second
278  * RTO.Max                  - 60 seconds
279  * RTO.Alpha                - 1/8
280  * RTO.Beta                 - 1/4
281  */
282 #define SCTP_RTO_INITIAL	(3 * 1000)
283 #define SCTP_RTO_MIN		(1 * 1000)
284 #define SCTP_RTO_MAX		(60 * 1000)
285 
286 #define SCTP_RTO_ALPHA          3   /* 1/8 when converted to right shifts. */
287 #define SCTP_RTO_BETA           2   /* 1/4 when converted to right shifts. */
288 
289 /* Maximum number of new data packets that can be sent in a burst.  */
290 #define SCTP_DEFAULT_MAX_BURST		4
291 
292 #define SCTP_CLOCK_GRANULARITY	1	/* 1 jiffy */
293 
294 #define SCTP_DEFAULT_COOKIE_LIFE	(60 * 1000) /* 60 seconds */
295 
296 #define SCTP_DEFAULT_MINWINDOW	1500	/* default minimum rwnd size */
297 #define SCTP_DEFAULT_MAXWINDOW	65535	/* default rwnd size */
298 #define SCTP_DEFAULT_RWND_SHIFT  4	/* by default, update on 1/16 of
299 					 * rcvbuf, which is 1/8 of initial
300 					 * window
301 					 */
302 #define SCTP_DEFAULT_MAXSEGMENT 1500	/* MTU size, this is the limit
303                                          * to which we will raise the P-MTU.
304 					 */
305 #define SCTP_DEFAULT_MINSEGMENT 512	/* MTU size ... if no mtu disc */
306 #define SCTP_HOW_MANY_SECRETS 2		/* How many secrets I keep */
307 #define SCTP_SECRET_SIZE 32		/* Number of octets in a 256 bits. */
308 
309 #define SCTP_SIGNATURE_SIZE 20	        /* size of a SLA-1 signature */
310 
311 #define SCTP_COOKIE_MULTIPLE 32 /* Pad out our cookie to make our hash
312 				 * functions simpler to write.
313 				 */
314 
315 #if defined (CONFIG_SCTP_HMAC_MD5)
316 #define SCTP_COOKIE_HMAC_ALG "hmac(md5)"
317 #elif defined (CONFIG_SCTP_HMAC_SHA1)
318 #define SCTP_COOKIE_HMAC_ALG "hmac(sha1)"
319 #else
320 #define SCTP_COOKIE_HMAC_ALG NULL
321 #endif
322 
323 /* These return values describe the success or failure of a number of
324  * routines which form the lower interface to SCTP_outqueue.
325  */
326 typedef enum {
327 	SCTP_XMIT_OK,
328 	SCTP_XMIT_PMTU_FULL,
329 	SCTP_XMIT_RWND_FULL,
330 	SCTP_XMIT_NAGLE_DELAY,
331 } sctp_xmit_t;
332 
333 /* These are the commands for manipulating transports.  */
334 typedef enum {
335 	SCTP_TRANSPORT_UP,
336 	SCTP_TRANSPORT_DOWN,
337 } sctp_transport_cmd_t;
338 
339 /* These are the address scopes defined mainly for IPv4 addresses
340  * based on draft of SCTP IPv4 scoping <draft-stewart-tsvwg-sctp-ipv4-00.txt>.
341  * These scopes are hopefully generic enough to be used on scoping both
342  * IPv4 and IPv6 addresses in SCTP.
343  * At this point, the IPv6 scopes will be mapped to these internal scopes
344  * as much as possible.
345  */
346 typedef enum {
347 	SCTP_SCOPE_GLOBAL,		/* IPv4 global addresses */
348 	SCTP_SCOPE_PRIVATE,		/* IPv4 private addresses */
349 	SCTP_SCOPE_LINK,		/* IPv4 link local address */
350 	SCTP_SCOPE_LOOPBACK,		/* IPv4 loopback address */
351 	SCTP_SCOPE_UNUSABLE,		/* IPv4 unusable addresses */
352 } sctp_scope_t;
353 
354 typedef enum {
355 	SCTP_SCOPE_POLICY_DISABLE,	/* Disable IPv4 address scoping */
356 	SCTP_SCOPE_POLICY_ENABLE,	/* Enable IPv4 address scoping */
357 	SCTP_SCOPE_POLICY_PRIVATE,	/* Follow draft but allow IPv4 private addresses */
358 	SCTP_SCOPE_POLICY_LINK,		/* Follow draft but allow IPv4 link local addresses */
359 } sctp_scope_policy_t;
360 
361 /* Based on IPv4 scoping <draft-stewart-tsvwg-sctp-ipv4-00.txt>,
362  * SCTP IPv4 unusable addresses: 0.0.0.0/8, 224.0.0.0/4, 198.18.0.0/24,
363  * 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_test_198(a) ||		    \
372 	 ipv4_is_anycast_6to4(a))
373 
374 /* Flags used for the bind address copy functions.  */
375 #define SCTP_ADDR6_ALLOWED	0x00000001	/* IPv6 address is allowed by
376 						   local sock family */
377 #define SCTP_ADDR4_PEERSUPP	0x00000002	/* IPv4 address is supported by
378 						   peer */
379 #define SCTP_ADDR6_PEERSUPP	0x00000004	/* IPv6 address is supported by
380 						   peer */
381 
382 /* Reasons to retransmit. */
383 typedef enum {
384 	SCTP_RTXR_T3_RTX,
385 	SCTP_RTXR_FAST_RTX,
386 	SCTP_RTXR_PMTUD,
387 	SCTP_RTXR_T1_RTX,
388 } sctp_retransmit_reason_t;
389 
390 /* Reasons to lower cwnd. */
391 typedef enum {
392 	SCTP_LOWER_CWND_T3_RTX,
393 	SCTP_LOWER_CWND_FAST_RTX,
394 	SCTP_LOWER_CWND_ECNE,
395 	SCTP_LOWER_CWND_INACTIVE,
396 } sctp_lower_cwnd_t;
397 
398 
399 /* SCTP-AUTH Necessary constants */
400 
401 /* SCTP-AUTH, Section 3.3
402  *
403  *  The following Table 2 shows the currently defined values for HMAC
404  *  identifiers.
405  *
406  *  +-----------------+--------------------------+
407  *  | HMAC Identifier | Message Digest Algorithm |
408  *  +-----------------+--------------------------+
409  *  | 0               | Reserved                 |
410  *  | 1               | SHA-1 defined in [8]     |
411  *  | 2               | Reserved                 |
412  *  | 3               | SHA-256 defined in [8]   |
413  *  +-----------------+--------------------------+
414  */
415 enum {
416 	SCTP_AUTH_HMAC_ID_RESERVED_0,
417 	SCTP_AUTH_HMAC_ID_SHA1,
418 	SCTP_AUTH_HMAC_ID_RESERVED_2,
419 #if defined (CONFIG_CRYPTO_SHA256) || defined (CONFIG_CRYPTO_SHA256_MODULE)
420 	SCTP_AUTH_HMAC_ID_SHA256,
421 #endif
422 	__SCTP_AUTH_HMAC_MAX
423 };
424 
425 #define SCTP_AUTH_HMAC_ID_MAX	__SCTP_AUTH_HMAC_MAX - 1
426 #define SCTP_AUTH_NUM_HMACS 	__SCTP_AUTH_HMAC_MAX
427 #define SCTP_SHA1_SIG_SIZE 20
428 #define SCTP_SHA256_SIG_SIZE 32
429 
430 /*  SCTP-AUTH, Section 3.2
431  *     The chunk types for INIT, INIT-ACK, SHUTDOWN-COMPLETE and AUTH chunks
432  *     MUST NOT be listed in the CHUNKS parameter
433  */
434 #define SCTP_NUM_NOAUTH_CHUNKS	4
435 #define SCTP_AUTH_MAX_CHUNKS	(SCTP_NUM_CHUNK_TYPES - SCTP_NUM_NOAUTH_CHUNKS)
436 
437 /* SCTP-AUTH Section 6.1
438  * The RANDOM parameter MUST contain a 32 byte random number.
439  */
440 #define SCTP_AUTH_RANDOM_LENGTH 32
441 
442 #endif /* __sctp_constants_h__ */
443