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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 #define SCTP_CID_MAX			SCTP_CID_ASCONF_ACK
65 
66 #define SCTP_NUM_BASE_CHUNK_TYPES	(SCTP_CID_BASE_MAX + 1)
67 
68 #define SCTP_NUM_ADDIP_CHUNK_TYPES	2
69 
70 #define SCTP_NUM_PRSCTP_CHUNK_TYPES	1
71 
72 #define SCTP_NUM_AUTH_CHUNK_TYPES	1
73 
74 #define SCTP_NUM_CHUNK_TYPES		(SCTP_NUM_BASE_CHUNK_TYPES + \
75 					 SCTP_NUM_ADDIP_CHUNK_TYPES +\
76 					 SCTP_NUM_PRSCTP_CHUNK_TYPES +\
77 					 SCTP_NUM_AUTH_CHUNK_TYPES)
78 
79 /* These are the different flavours of event.  */
80 typedef enum {
81 
82 	SCTP_EVENT_T_CHUNK = 1,
83 	SCTP_EVENT_T_TIMEOUT,
84 	SCTP_EVENT_T_OTHER,
85 	SCTP_EVENT_T_PRIMITIVE
86 
87 } sctp_event_t;
88 
89 #define SCTP_EVENT_T_MAX SCTP_EVENT_T_PRIMITIVE
90 #define SCTP_EVENT_T_NUM (SCTP_EVENT_T_MAX + 1)
91 
92 /* As a convenience for the state machine, we append SCTP_EVENT_* and
93  * SCTP_ULP_* to the list of possible chunks.
94  */
95 
96 typedef enum {
97 	SCTP_EVENT_TIMEOUT_NONE = 0,
98 	SCTP_EVENT_TIMEOUT_T1_COOKIE,
99 	SCTP_EVENT_TIMEOUT_T1_INIT,
100 	SCTP_EVENT_TIMEOUT_T2_SHUTDOWN,
101 	SCTP_EVENT_TIMEOUT_T3_RTX,
102 	SCTP_EVENT_TIMEOUT_T4_RTO,
103 	SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD,
104 	SCTP_EVENT_TIMEOUT_HEARTBEAT,
105 	SCTP_EVENT_TIMEOUT_SACK,
106 	SCTP_EVENT_TIMEOUT_AUTOCLOSE,
107 } sctp_event_timeout_t;
108 
109 #define SCTP_EVENT_TIMEOUT_MAX		SCTP_EVENT_TIMEOUT_AUTOCLOSE
110 #define SCTP_NUM_TIMEOUT_TYPES		(SCTP_EVENT_TIMEOUT_MAX + 1)
111 
112 typedef enum {
113 	SCTP_EVENT_NO_PENDING_TSN = 0,
114 	SCTP_EVENT_ICMP_PROTO_UNREACH,
115 } sctp_event_other_t;
116 
117 #define SCTP_EVENT_OTHER_MAX		SCTP_EVENT_ICMP_PROTO_UNREACH
118 #define SCTP_NUM_OTHER_TYPES		(SCTP_EVENT_OTHER_MAX + 1)
119 
120 /* These are primitive requests from the ULP.  */
121 typedef enum {
122 	SCTP_PRIMITIVE_ASSOCIATE = 0,
123 	SCTP_PRIMITIVE_SHUTDOWN,
124 	SCTP_PRIMITIVE_ABORT,
125 	SCTP_PRIMITIVE_SEND,
126 	SCTP_PRIMITIVE_REQUESTHEARTBEAT,
127 	SCTP_PRIMITIVE_ASCONF,
128 } sctp_event_primitive_t;
129 
130 #define SCTP_EVENT_PRIMITIVE_MAX	SCTP_PRIMITIVE_ASCONF
131 #define SCTP_NUM_PRIMITIVE_TYPES	(SCTP_EVENT_PRIMITIVE_MAX + 1)
132 
133 /* We define here a utility type for manipulating subtypes.
134  * The subtype constructors all work like this:
135  *
136  * 	sctp_subtype_t foo = SCTP_ST_CHUNK(SCTP_CID_INIT);
137  */
138 
139 typedef union {
140 	sctp_cid_t chunk;
141 	sctp_event_timeout_t timeout;
142 	sctp_event_other_t other;
143 	sctp_event_primitive_t primitive;
144 } sctp_subtype_t;
145 
146 #define SCTP_SUBTYPE_CONSTRUCTOR(_name, _type, _elt) \
147 static inline sctp_subtype_t	\
148 SCTP_ST_## _name (_type _arg)		\
149 { sctp_subtype_t _retval; _retval._elt = _arg; return _retval; }
150 
151 SCTP_SUBTYPE_CONSTRUCTOR(CHUNK,		sctp_cid_t,		chunk)
152 SCTP_SUBTYPE_CONSTRUCTOR(TIMEOUT,	sctp_event_timeout_t,	timeout)
153 SCTP_SUBTYPE_CONSTRUCTOR(OTHER,		sctp_event_other_t,	other)
154 SCTP_SUBTYPE_CONSTRUCTOR(PRIMITIVE,	sctp_event_primitive_t,	primitive)
155 
156 
157 #define sctp_chunk_is_control(a) (a->chunk_hdr->type != SCTP_CID_DATA)
158 #define sctp_chunk_is_data(a) (a->chunk_hdr->type == SCTP_CID_DATA)
159 
160 /* Calculate the actual data size in a data chunk */
161 #define SCTP_DATA_SNDSIZE(c) ((int)((unsigned long)(c->chunk_end)\
162 		       		- (unsigned long)(c->chunk_hdr)\
163 				- sizeof(sctp_data_chunk_t)))
164 
165 #define SCTP_MAX_ERROR_CAUSE  SCTP_ERROR_NONEXIST_IP
166 #define SCTP_NUM_ERROR_CAUSE  10
167 
168 /* Internal error codes */
169 typedef enum {
170 
171 	SCTP_IERROR_NO_ERROR	        = 0,
172 	SCTP_IERROR_BASE		= 1000,
173 	SCTP_IERROR_NO_COOKIE,
174 	SCTP_IERROR_BAD_SIG,
175 	SCTP_IERROR_STALE_COOKIE,
176 	SCTP_IERROR_NOMEM,
177 	SCTP_IERROR_MALFORMED,
178 	SCTP_IERROR_BAD_TAG,
179 	SCTP_IERROR_BIG_GAP,
180 	SCTP_IERROR_DUP_TSN,
181 	SCTP_IERROR_HIGH_TSN,
182 	SCTP_IERROR_IGNORE_TSN,
183 	SCTP_IERROR_NO_DATA,
184 	SCTP_IERROR_BAD_STREAM,
185 	SCTP_IERROR_BAD_PORTS,
186 	SCTP_IERROR_AUTH_BAD_HMAC,
187 	SCTP_IERROR_AUTH_BAD_KEYID,
188 	SCTP_IERROR_PROTO_VIOLATION,
189 	SCTP_IERROR_ERROR,
190 	SCTP_IERROR_ABORT,
191 } sctp_ierror_t;
192 
193 
194 
195 /* SCTP state defines for internal state machine */
196 typedef enum {
197 
198 	SCTP_STATE_EMPTY		= 0,
199 	SCTP_STATE_CLOSED		= 1,
200 	SCTP_STATE_COOKIE_WAIT		= 2,
201 	SCTP_STATE_COOKIE_ECHOED	= 3,
202 	SCTP_STATE_ESTABLISHED		= 4,
203 	SCTP_STATE_SHUTDOWN_PENDING	= 5,
204 	SCTP_STATE_SHUTDOWN_SENT	= 6,
205 	SCTP_STATE_SHUTDOWN_RECEIVED	= 7,
206 	SCTP_STATE_SHUTDOWN_ACK_SENT	= 8,
207 
208 } sctp_state_t;
209 
210 #define SCTP_STATE_MAX			SCTP_STATE_SHUTDOWN_ACK_SENT
211 #define SCTP_STATE_NUM_STATES		(SCTP_STATE_MAX + 1)
212 
213 /* These are values for sk->state.
214  * For a UDP-style SCTP socket, the states are defined as follows
215  * - A socket in SCTP_SS_CLOSED state indicates that it is not willing to
216  *   accept new associations, but it can initiate the creation of new ones.
217  * - A socket in SCTP_SS_LISTENING state indicates that it is willing to
218  *   accept new  associations and can initiate the creation of new ones.
219  * - A socket in SCTP_SS_ESTABLISHED state indicates that it is a peeled off
220  *   socket with one association.
221  * For a TCP-style SCTP socket, the states are defined as follows
222  * - A socket in SCTP_SS_CLOSED state indicates that it is not willing to
223  *   accept new associations, but it can initiate the creation of new ones.
224  * - A socket in SCTP_SS_LISTENING state indicates that it is willing to
225  *   accept new associations, but cannot initiate the creation of new ones.
226  * - A socket in SCTP_SS_ESTABLISHED state indicates that it has a single
227  *   association.
228  */
229 typedef enum {
230 	SCTP_SS_CLOSED         = TCP_CLOSE,
231 	SCTP_SS_LISTENING      = TCP_LISTEN,
232 	SCTP_SS_ESTABLISHING   = TCP_SYN_SENT,
233 	SCTP_SS_ESTABLISHED    = TCP_ESTABLISHED,
234 	SCTP_SS_DISCONNECTING  = TCP_CLOSING,
235 } sctp_sock_state_t;
236 
237 /* These functions map various type to printable names.  */
238 const char *sctp_cname(const sctp_subtype_t);	/* chunk types */
239 const char *sctp_oname(const sctp_subtype_t);	/* other events */
240 const char *sctp_tname(const sctp_subtype_t);	/* timeouts */
241 const char *sctp_pname(const sctp_subtype_t);	/* primitives */
242 
243 /* This is a table of printable names of sctp_state_t's.  */
244 extern const char *sctp_state_tbl[], *sctp_evttype_tbl[], *sctp_status_tbl[];
245 
246 /* Maximum chunk length considering padding requirements. */
247 enum { SCTP_MAX_CHUNK_LEN = ((1<<16) - sizeof(__u32)) };
248 
249 /* Encourage Cookie-Echo bundling by pre-fragmenting chunks a little
250  * harder (until reaching ESTABLISHED state).
251  */
252 enum { SCTP_ARBITRARY_COOKIE_ECHO_LEN = 200 };
253 
254 /* Guess at how big to make the TSN mapping array.
255  * We guarantee that we can handle at least this big a gap between the
256  * cumulative ACK and the highest TSN.  In practice, we can often
257  * handle up to twice this value.
258  *
259  * NEVER make this more than 32767 (2^15-1).  The Gap Ack Blocks in a
260  * SACK (see  section 3.3.4) are only 16 bits, so 2*SCTP_TSN_MAP_SIZE
261  * must be less than 65535 (2^16 - 1), or we will have overflow
262  * problems creating SACK's.
263  */
264 #define SCTP_TSN_MAP_INITIAL BITS_PER_LONG
265 #define SCTP_TSN_MAP_INCREMENT SCTP_TSN_MAP_INITIAL
266 #define SCTP_TSN_MAP_SIZE 4096
267 #define SCTP_TSN_MAX_GAP  65535
268 
269 /* We will not record more than this many duplicate TSNs between two
270  * SACKs.  The minimum PMTU is 576.  Remove all the headers and there
271  * is enough room for 131 duplicate reports.  Round down to the
272  * nearest power of 2.
273  */
274 enum { SCTP_MIN_PMTU = 576 };
275 enum { SCTP_MAX_DUP_TSNS = 16 };
276 enum { SCTP_MAX_GABS = 16 };
277 
278 /* Heartbeat interval - 30 secs */
279 #define SCTP_DEFAULT_TIMEOUT_HEARTBEAT	(30*1000)
280 
281 /* Delayed sack timer - 200ms */
282 #define SCTP_DEFAULT_TIMEOUT_SACK	(200)
283 
284 /* RTO.Initial              - 3  seconds
285  * RTO.Min                  - 1  second
286  * RTO.Max                  - 60 seconds
287  * RTO.Alpha                - 1/8
288  * RTO.Beta                 - 1/4
289  */
290 #define SCTP_RTO_INITIAL	(3 * 1000)
291 #define SCTP_RTO_MIN		(1 * 1000)
292 #define SCTP_RTO_MAX		(60 * 1000)
293 
294 #define SCTP_RTO_ALPHA          3   /* 1/8 when converted to right shifts. */
295 #define SCTP_RTO_BETA           2   /* 1/4 when converted to right shifts. */
296 
297 /* Maximum number of new data packets that can be sent in a burst.  */
298 #define SCTP_DEFAULT_MAX_BURST		4
299 
300 #define SCTP_CLOCK_GRANULARITY	1	/* 1 jiffy */
301 
302 #define SCTP_DEF_MAX_INIT 6
303 #define SCTP_DEF_MAX_SEND 10
304 
305 #define SCTP_DEFAULT_COOKIE_LIFE	(60 * 1000) /* 60 seconds */
306 
307 #define SCTP_DEFAULT_MINWINDOW	1500	/* default minimum rwnd size */
308 #define SCTP_DEFAULT_MAXWINDOW	65535	/* default rwnd size */
309 #define SCTP_DEFAULT_MAXSEGMENT 1500	/* MTU size, this is the limit
310                                          * to which we will raise the P-MTU.
311 					 */
312 #define SCTP_DEFAULT_MINSEGMENT 512	/* MTU size ... if no mtu disc */
313 #define SCTP_HOW_MANY_SECRETS 2		/* How many secrets I keep */
314 #define SCTP_HOW_LONG_COOKIE_LIVE 3600	/* How many seconds the current
315 					 * secret will live?
316 					 */
317 #define SCTP_SECRET_SIZE 32		/* Number of octets in a 256 bits. */
318 
319 #define SCTP_SIGNATURE_SIZE 20	        /* size of a SLA-1 signature */
320 
321 #define SCTP_COOKIE_MULTIPLE 32 /* Pad out our cookie to make our hash
322 				 * functions simpler to write.
323 				 */
324 
325 #if defined (CONFIG_SCTP_HMAC_MD5)
326 #define SCTP_COOKIE_HMAC_ALG "hmac(md5)"
327 #elif defined (CONFIG_SCTP_HMAC_SHA1)
328 #define SCTP_COOKIE_HMAC_ALG "hmac(sha1)"
329 #else
330 #define SCTP_COOKIE_HMAC_ALG NULL
331 #endif
332 
333 /* These return values describe the success or failure of a number of
334  * routines which form the lower interface to SCTP_outqueue.
335  */
336 typedef enum {
337 	SCTP_XMIT_OK,
338 	SCTP_XMIT_PMTU_FULL,
339 	SCTP_XMIT_RWND_FULL,
340 	SCTP_XMIT_NAGLE_DELAY,
341 } sctp_xmit_t;
342 
343 /* These are the commands for manipulating transports.  */
344 typedef enum {
345 	SCTP_TRANSPORT_UP,
346 	SCTP_TRANSPORT_DOWN,
347 } sctp_transport_cmd_t;
348 
349 /* These are the address scopes defined mainly for IPv4 addresses
350  * based on draft of SCTP IPv4 scoping <draft-stewart-tsvwg-sctp-ipv4-00.txt>.
351  * These scopes are hopefully generic enough to be used on scoping both
352  * IPv4 and IPv6 addresses in SCTP.
353  * At this point, the IPv6 scopes will be mapped to these internal scopes
354  * as much as possible.
355  */
356 typedef enum {
357 	SCTP_SCOPE_GLOBAL,		/* IPv4 global addresses */
358 	SCTP_SCOPE_PRIVATE,		/* IPv4 private addresses */
359 	SCTP_SCOPE_LINK,		/* IPv4 link local address */
360 	SCTP_SCOPE_LOOPBACK,		/* IPv4 loopback address */
361 	SCTP_SCOPE_UNUSABLE,		/* IPv4 unusable addresses */
362 } sctp_scope_t;
363 
364 /* Based on IPv4 scoping <draft-stewart-tsvwg-sctp-ipv4-00.txt>,
365  * SCTP IPv4 unusable addresses: 0.0.0.0/8, 224.0.0.0/4, 198.18.0.0/24,
366  * 192.88.99.0/24.
367  * Also, RFC 8.4, non-unicast addresses are not considered valid SCTP
368  * addresses.
369  */
370 #define IS_IPV4_UNUSABLE_ADDRESS(a)	    \
371 	((htonl(INADDR_BROADCAST) == a) ||  \
372 	 ipv4_is_multicast(a) ||	    \
373 	 ipv4_is_zeronet(a) ||		    \
374 	 ipv4_is_test_198(a) ||		    \
375 	 ipv4_is_anycast_6to4(a))
376 
377 /* Flags used for the bind address copy functions.  */
378 #define SCTP_ADDR6_ALLOWED	0x00000001	/* IPv6 address is allowed by
379 						   local sock family */
380 #define SCTP_ADDR4_PEERSUPP	0x00000002	/* IPv4 address is supported by
381 						   peer */
382 #define SCTP_ADDR6_PEERSUPP	0x00000004	/* IPv6 address is supported by
383 						   peer */
384 
385 /* Reasons to retransmit. */
386 typedef enum {
387 	SCTP_RTXR_T3_RTX,
388 	SCTP_RTXR_FAST_RTX,
389 	SCTP_RTXR_PMTUD,
390 	SCTP_RTXR_T1_RTX,
391 } sctp_retransmit_reason_t;
392 
393 /* Reasons to lower cwnd. */
394 typedef enum {
395 	SCTP_LOWER_CWND_T3_RTX,
396 	SCTP_LOWER_CWND_FAST_RTX,
397 	SCTP_LOWER_CWND_ECNE,
398 	SCTP_LOWER_CWND_INACTIVE,
399 } sctp_lower_cwnd_t;
400 
401 
402 /* SCTP-AUTH Necessary constants */
403 
404 /* SCTP-AUTH, Section 3.3
405  *
406  *  The following Table 2 shows the currently defined values for HMAC
407  *  identifiers.
408  *
409  *  +-----------------+--------------------------+
410  *  | HMAC Identifier | Message Digest Algorithm |
411  *  +-----------------+--------------------------+
412  *  | 0               | Reserved                 |
413  *  | 1               | SHA-1 defined in [8]     |
414  *  | 2               | Reserved                 |
415  *  | 3               | SHA-256 defined in [8]   |
416  *  +-----------------+--------------------------+
417  */
418 enum {
419 	SCTP_AUTH_HMAC_ID_RESERVED_0,
420 	SCTP_AUTH_HMAC_ID_SHA1,
421 	SCTP_AUTH_HMAC_ID_RESERVED_2,
422 #if defined (CONFIG_CRYPTO_SHA256) || defined (CONFIG_CRYPTO_SHA256_MODULE)
423 	SCTP_AUTH_HMAC_ID_SHA256,
424 #endif
425 	__SCTP_AUTH_HMAC_MAX
426 };
427 
428 #define SCTP_AUTH_HMAC_ID_MAX	__SCTP_AUTH_HMAC_MAX - 1
429 #define SCTP_AUTH_NUM_HMACS 	__SCTP_AUTH_HMAC_MAX
430 #define SCTP_SHA1_SIG_SIZE 20
431 #define SCTP_SHA256_SIG_SIZE 32
432 
433 /*  SCTP-AUTH, Section 3.2
434  *     The chunk types for INIT, INIT-ACK, SHUTDOWN-COMPLETE and AUTH chunks
435  *     MUST NOT be listed in the CHUNKS parameter
436  */
437 #define SCTP_NUM_NOAUTH_CHUNKS	4
438 #define SCTP_AUTH_MAX_CHUNKS	(SCTP_NUM_CHUNK_TYPES - SCTP_NUM_NOAUTH_CHUNKS)
439 
440 /* SCTP-AUTH Section 6.1
441  * The RANDOM parameter MUST contain a 32 byte random number.
442  */
443 #define SCTP_AUTH_RANDOM_LENGTH 32
444 
445 #endif /* __sctp_constants_h__ */
446