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 * These are definitions needed by the state machine.
11 *
12 * Please send any bug reports or fixes you make to the
13 * email addresses:
14 * lksctp developers <linux-sctp@vger.kernel.org>
15 *
16 * Written or modified by:
17 * La Monte H.P. Yarroll <piggy@acm.org>
18 * Karl Knutson <karl@athena.chicago.il.us>
19 * Xingang Guo <xingang.guo@intel.com>
20 * Jon Grimm <jgrimm@us.ibm.com>
21 * Dajiang Zhang <dajiang.zhang@nokia.com>
22 * Sridhar Samudrala <sri@us.ibm.com>
23 * Daisy Chang <daisyc@us.ibm.com>
24 * Ardelle Fan <ardelle.fan@intel.com>
25 * Kevin Gao <kevin.gao@intel.com>
26 */
27
28 #include <linux/types.h>
29 #include <linux/compiler.h>
30 #include <linux/slab.h>
31 #include <linux/in.h>
32 #include <net/sctp/command.h>
33 #include <net/sctp/sctp.h>
34
35 #ifndef __sctp_sm_h__
36 #define __sctp_sm_h__
37
38 /*
39 * Possible values for the disposition are:
40 */
41 enum sctp_disposition {
42 SCTP_DISPOSITION_DISCARD, /* No further processing. */
43 SCTP_DISPOSITION_CONSUME, /* Process return values normally. */
44 SCTP_DISPOSITION_NOMEM, /* We ran out of memory--recover. */
45 SCTP_DISPOSITION_DELETE_TCB, /* Close the association. */
46 SCTP_DISPOSITION_ABORT, /* Close the association NOW. */
47 SCTP_DISPOSITION_VIOLATION, /* The peer is misbehaving. */
48 SCTP_DISPOSITION_NOT_IMPL, /* This entry is not implemented. */
49 SCTP_DISPOSITION_ERROR, /* This is plain old user error. */
50 SCTP_DISPOSITION_BUG, /* This is a bug. */
51 };
52
53 typedef enum sctp_disposition (sctp_state_fn_t) (
54 struct net *net,
55 const struct sctp_endpoint *ep,
56 const struct sctp_association *asoc,
57 const union sctp_subtype type,
58 void *arg,
59 struct sctp_cmd_seq *commands);
60 typedef void (sctp_timer_event_t) (struct timer_list *);
61 struct sctp_sm_table_entry {
62 sctp_state_fn_t *fn;
63 const char *name;
64 };
65
66 /* A naming convention of "sctp_sf_xxx" applies to all the state functions
67 * currently in use.
68 */
69
70 /* Prototypes for generic state functions. */
71 sctp_state_fn_t sctp_sf_not_impl;
72 sctp_state_fn_t sctp_sf_bug;
73
74 /* Prototypes for gener timer state functions. */
75 sctp_state_fn_t sctp_sf_timer_ignore;
76
77 /* Prototypes for chunk state functions. */
78 sctp_state_fn_t sctp_sf_do_9_1_abort;
79 sctp_state_fn_t sctp_sf_cookie_wait_abort;
80 sctp_state_fn_t sctp_sf_cookie_echoed_abort;
81 sctp_state_fn_t sctp_sf_shutdown_pending_abort;
82 sctp_state_fn_t sctp_sf_shutdown_sent_abort;
83 sctp_state_fn_t sctp_sf_shutdown_ack_sent_abort;
84 sctp_state_fn_t sctp_sf_do_5_1B_init;
85 sctp_state_fn_t sctp_sf_do_5_1C_ack;
86 sctp_state_fn_t sctp_sf_do_5_1D_ce;
87 sctp_state_fn_t sctp_sf_do_5_1E_ca;
88 sctp_state_fn_t sctp_sf_do_4_C;
89 sctp_state_fn_t sctp_sf_eat_data_6_2;
90 sctp_state_fn_t sctp_sf_eat_data_fast_4_4;
91 sctp_state_fn_t sctp_sf_eat_sack_6_2;
92 sctp_state_fn_t sctp_sf_operr_notify;
93 sctp_state_fn_t sctp_sf_t1_init_timer_expire;
94 sctp_state_fn_t sctp_sf_t1_cookie_timer_expire;
95 sctp_state_fn_t sctp_sf_t2_timer_expire;
96 sctp_state_fn_t sctp_sf_t4_timer_expire;
97 sctp_state_fn_t sctp_sf_t5_timer_expire;
98 sctp_state_fn_t sctp_sf_sendbeat_8_3;
99 sctp_state_fn_t sctp_sf_beat_8_3;
100 sctp_state_fn_t sctp_sf_backbeat_8_3;
101 sctp_state_fn_t sctp_sf_do_9_2_final;
102 sctp_state_fn_t sctp_sf_do_9_2_shutdown;
103 sctp_state_fn_t sctp_sf_do_9_2_shut_ctsn;
104 sctp_state_fn_t sctp_sf_do_ecn_cwr;
105 sctp_state_fn_t sctp_sf_do_ecne;
106 sctp_state_fn_t sctp_sf_ootb;
107 sctp_state_fn_t sctp_sf_pdiscard;
108 sctp_state_fn_t sctp_sf_violation;
109 sctp_state_fn_t sctp_sf_discard_chunk;
110 sctp_state_fn_t sctp_sf_do_5_2_1_siminit;
111 sctp_state_fn_t sctp_sf_do_5_2_2_dupinit;
112 sctp_state_fn_t sctp_sf_do_5_2_3_initack;
113 sctp_state_fn_t sctp_sf_do_5_2_4_dupcook;
114 sctp_state_fn_t sctp_sf_unk_chunk;
115 sctp_state_fn_t sctp_sf_do_8_5_1_E_sa;
116 sctp_state_fn_t sctp_sf_cookie_echoed_err;
117 sctp_state_fn_t sctp_sf_do_asconf;
118 sctp_state_fn_t sctp_sf_do_asconf_ack;
119 sctp_state_fn_t sctp_sf_do_reconf;
120 sctp_state_fn_t sctp_sf_do_9_2_reshutack;
121 sctp_state_fn_t sctp_sf_eat_fwd_tsn;
122 sctp_state_fn_t sctp_sf_eat_fwd_tsn_fast;
123 sctp_state_fn_t sctp_sf_eat_auth;
124
125 /* Prototypes for primitive event state functions. */
126 sctp_state_fn_t sctp_sf_do_prm_asoc;
127 sctp_state_fn_t sctp_sf_do_prm_send;
128 sctp_state_fn_t sctp_sf_do_9_2_prm_shutdown;
129 sctp_state_fn_t sctp_sf_cookie_wait_prm_shutdown;
130 sctp_state_fn_t sctp_sf_cookie_echoed_prm_shutdown;
131 sctp_state_fn_t sctp_sf_do_9_1_prm_abort;
132 sctp_state_fn_t sctp_sf_cookie_wait_prm_abort;
133 sctp_state_fn_t sctp_sf_cookie_echoed_prm_abort;
134 sctp_state_fn_t sctp_sf_shutdown_pending_prm_abort;
135 sctp_state_fn_t sctp_sf_shutdown_sent_prm_abort;
136 sctp_state_fn_t sctp_sf_shutdown_ack_sent_prm_abort;
137 sctp_state_fn_t sctp_sf_error_closed;
138 sctp_state_fn_t sctp_sf_error_shutdown;
139 sctp_state_fn_t sctp_sf_ignore_primitive;
140 sctp_state_fn_t sctp_sf_do_prm_requestheartbeat;
141 sctp_state_fn_t sctp_sf_do_prm_asconf;
142 sctp_state_fn_t sctp_sf_do_prm_reconf;
143
144 /* Prototypes for other event state functions. */
145 sctp_state_fn_t sctp_sf_do_no_pending_tsn;
146 sctp_state_fn_t sctp_sf_do_9_2_start_shutdown;
147 sctp_state_fn_t sctp_sf_do_9_2_shutdown_ack;
148 sctp_state_fn_t sctp_sf_ignore_other;
149 sctp_state_fn_t sctp_sf_cookie_wait_icmp_abort;
150
151 /* Prototypes for timeout event state functions. */
152 sctp_state_fn_t sctp_sf_do_6_3_3_rtx;
153 sctp_state_fn_t sctp_sf_send_reconf;
154 sctp_state_fn_t sctp_sf_send_probe;
155 sctp_state_fn_t sctp_sf_do_6_2_sack;
156 sctp_state_fn_t sctp_sf_autoclose_timer_expire;
157
158 /* Prototypes for utility support functions. */
159 const struct sctp_sm_table_entry *sctp_sm_lookup_event(
160 struct net *net,
161 enum sctp_event_type event_type,
162 enum sctp_state state,
163 union sctp_subtype event_subtype);
164 int sctp_chunk_iif(const struct sctp_chunk *);
165 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *,
166 struct sctp_chunk *,
167 gfp_t gfp);
168
169 /* Prototypes for chunk-building functions. */
170 struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc,
171 const struct sctp_bind_addr *bp,
172 gfp_t gfp, int vparam_len);
173 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc,
174 const struct sctp_chunk *chunk,
175 const gfp_t gfp, const int unkparam_len);
176 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc,
177 const struct sctp_chunk *chunk);
178 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc,
179 const struct sctp_chunk *chunk);
180 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc,
181 const __u32 lowest_tsn,
182 const struct sctp_chunk *chunk);
183 struct sctp_chunk *sctp_make_idata(const struct sctp_association *asoc,
184 __u8 flags, int paylen, gfp_t gfp);
185 struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc,
186 __u32 new_cum_tsn, size_t nstreams,
187 struct sctp_ifwdtsn_skip *skiplist);
188 struct sctp_chunk *sctp_make_datafrag_empty(const struct sctp_association *asoc,
189 const struct sctp_sndrcvinfo *sinfo,
190 int len, __u8 flags, gfp_t gfp);
191 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc,
192 const __u32 lowest_tsn);
193 struct sctp_chunk *sctp_make_sack(struct sctp_association *asoc);
194 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,
195 const struct sctp_chunk *chunk);
196 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc,
197 const struct sctp_chunk *chunk);
198 struct sctp_chunk *sctp_make_shutdown_complete(
199 const struct sctp_association *asoc,
200 const struct sctp_chunk *chunk);
201 int sctp_init_cause(struct sctp_chunk *chunk, __be16 cause, size_t paylen);
202 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc,
203 const struct sctp_chunk *chunk,
204 const size_t hint);
205 struct sctp_chunk *sctp_make_abort_no_data(const struct sctp_association *asoc,
206 const struct sctp_chunk *chunk,
207 __u32 tsn);
208 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc,
209 struct msghdr *msg, size_t msg_len);
210 struct sctp_chunk *sctp_make_abort_violation(
211 const struct sctp_association *asoc,
212 const struct sctp_chunk *chunk,
213 const __u8 *payload,
214 const size_t paylen);
215 struct sctp_chunk *sctp_make_violation_paramlen(
216 const struct sctp_association *asoc,
217 const struct sctp_chunk *chunk,
218 struct sctp_paramhdr *param);
219 struct sctp_chunk *sctp_make_violation_max_retrans(
220 const struct sctp_association *asoc,
221 const struct sctp_chunk *chunk);
222 struct sctp_chunk *sctp_make_new_encap_port(
223 const struct sctp_association *asoc,
224 const struct sctp_chunk *chunk);
225 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc,
226 const struct sctp_transport *transport,
227 __u32 probe_size);
228 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc,
229 const struct sctp_chunk *chunk,
230 const void *payload,
231 const size_t paylen);
232 struct sctp_chunk *sctp_make_pad(const struct sctp_association *asoc, int len);
233 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc,
234 const struct sctp_chunk *chunk,
235 __be16 cause_code, const void *payload,
236 size_t paylen, size_t reserve_tail);
237
238 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc,
239 union sctp_addr *laddr,
240 struct sockaddr *addrs,
241 int addrcnt, __be16 flags);
242 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
243 union sctp_addr *addr);
244 bool sctp_verify_asconf(const struct sctp_association *asoc,
245 struct sctp_chunk *chunk, bool addr_param_needed,
246 struct sctp_paramhdr **errp);
247 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
248 struct sctp_chunk *asconf);
249 int sctp_process_asconf_ack(struct sctp_association *asoc,
250 struct sctp_chunk *asconf_ack);
251 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
252 __u32 new_cum_tsn, size_t nstreams,
253 struct sctp_fwdtsn_skip *skiplist);
254 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc,
255 __u16 key_id);
256 struct sctp_chunk *sctp_make_strreset_req(const struct sctp_association *asoc,
257 __u16 stream_num, __be16 *stream_list,
258 bool out, bool in);
259 struct sctp_chunk *sctp_make_strreset_tsnreq(
260 const struct sctp_association *asoc);
261 struct sctp_chunk *sctp_make_strreset_addstrm(
262 const struct sctp_association *asoc,
263 __u16 out, __u16 in);
264 struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc,
265 __u32 result, __u32 sn);
266 struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc,
267 __u32 result, __u32 sn,
268 __u32 sender_tsn,
269 __u32 receiver_tsn);
270 bool sctp_verify_reconf(const struct sctp_association *asoc,
271 struct sctp_chunk *chunk,
272 struct sctp_paramhdr **errp);
273 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk);
274 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk);
275
276 /* Prototypes for stream-processing functions. */
277 struct sctp_chunk *sctp_process_strreset_outreq(
278 struct sctp_association *asoc,
279 union sctp_params param,
280 struct sctp_ulpevent **evp);
281 struct sctp_chunk *sctp_process_strreset_inreq(
282 struct sctp_association *asoc,
283 union sctp_params param,
284 struct sctp_ulpevent **evp);
285 struct sctp_chunk *sctp_process_strreset_tsnreq(
286 struct sctp_association *asoc,
287 union sctp_params param,
288 struct sctp_ulpevent **evp);
289 struct sctp_chunk *sctp_process_strreset_addstrm_out(
290 struct sctp_association *asoc,
291 union sctp_params param,
292 struct sctp_ulpevent **evp);
293 struct sctp_chunk *sctp_process_strreset_addstrm_in(
294 struct sctp_association *asoc,
295 union sctp_params param,
296 struct sctp_ulpevent **evp);
297 struct sctp_chunk *sctp_process_strreset_resp(
298 struct sctp_association *asoc,
299 union sctp_params param,
300 struct sctp_ulpevent **evp);
301
302 /* Prototypes for statetable processing. */
303
304 int sctp_do_sm(struct net *net, enum sctp_event_type event_type,
305 union sctp_subtype subtype, enum sctp_state state,
306 struct sctp_endpoint *ep, struct sctp_association *asoc,
307 void *event_arg, gfp_t gfp);
308
309 /* 2nd level prototypes */
310 void sctp_generate_t3_rtx_event(struct timer_list *t);
311 void sctp_generate_heartbeat_event(struct timer_list *t);
312 void sctp_generate_reconf_event(struct timer_list *t);
313 void sctp_generate_probe_event(struct timer_list *t);
314 void sctp_generate_proto_unreach_event(struct timer_list *t);
315
316 void sctp_ootb_pkt_free(struct sctp_packet *packet);
317
318 struct sctp_association *sctp_unpack_cookie(
319 const struct sctp_endpoint *ep,
320 const struct sctp_association *asoc,
321 struct sctp_chunk *chunk,
322 gfp_t gfp, int *err,
323 struct sctp_chunk **err_chk_p);
324
325 /* 3rd level prototypes */
326 __u32 sctp_generate_tag(const struct sctp_endpoint *ep);
327 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep);
328
329 /* Extern declarations for major data structures. */
330 extern sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES];
331
332
333 /* Get the size of a DATA chunk payload. */
334 static inline __u16 sctp_data_size(struct sctp_chunk *chunk)
335 {
336 __u16 size;
337
338 size = ntohs(chunk->chunk_hdr->length);
339 size -= sctp_datachk_len(&chunk->asoc->stream);
340
341 return size;
342 }
343
344 /* Compare two TSNs */
345 #define TSN_lt(a,b) \
346 (typecheck(__u32, a) && \
347 typecheck(__u32, b) && \
348 ((__s32)((a) - (b)) < 0))
349
350 #define TSN_lte(a,b) \
351 (typecheck(__u32, a) && \
352 typecheck(__u32, b) && \
353 ((__s32)((a) - (b)) <= 0))
354
355 /* Compare two MIDs */
356 #define MID_lt(a, b) \
357 (typecheck(__u32, a) && \
358 typecheck(__u32, b) && \
359 ((__s32)((a) - (b)) < 0))
360
361 /* Compare two SSNs */
362 #define SSN_lt(a,b) \
363 (typecheck(__u16, a) && \
364 typecheck(__u16, b) && \
365 ((__s16)((a) - (b)) < 0))
366
367 /* ADDIP 3.1.1 */
368 #define ADDIP_SERIAL_gte(a,b) \
369 (typecheck(__u32, a) && \
370 typecheck(__u32, b) && \
371 ((__s32)((b) - (a)) <= 0))
372
373 /* Check VTAG of the packet matches the sender's own tag. */
374 static inline int
375 sctp_vtag_verify(const struct sctp_chunk *chunk,
376 const struct sctp_association *asoc)
377 {
378 /* RFC 2960 Sec 8.5 When receiving an SCTP packet, the endpoint
379 * MUST ensure that the value in the Verification Tag field of
380 * the received SCTP packet matches its own Tag. If the received
381 * Verification Tag value does not match the receiver's own
382 * tag value, the receiver shall silently discard the packet...
383 */
384 if (ntohl(chunk->sctp_hdr->vtag) != asoc->c.my_vtag)
385 return 0;
386
387 chunk->transport->encap_port = SCTP_INPUT_CB(chunk->skb)->encap_port;
388 return 1;
389 }
390
391 /* Check VTAG of the packet matches the sender's own tag and the T bit is
392 * not set, OR its peer's tag and the T bit is set in the Chunk Flags.
393 */
394 static inline int
395 sctp_vtag_verify_either(const struct sctp_chunk *chunk,
396 const struct sctp_association *asoc)
397 {
398 /* RFC 2960 Section 8.5.1, sctpimpguide Section 2.41
399 *
400 * B) The receiver of a ABORT MUST accept the packet
401 * if the Verification Tag field of the packet matches its own tag
402 * and the T bit is not set
403 * OR
404 * it is set to its peer's tag and the T bit is set in the Chunk
405 * Flags.
406 * Otherwise, the receiver MUST silently discard the packet
407 * and take no further action.
408 *
409 * C) The receiver of a SHUTDOWN COMPLETE shall accept the packet
410 * if the Verification Tag field of the packet matches its own tag
411 * and the T bit is not set
412 * OR
413 * it is set to its peer's tag and the T bit is set in the Chunk
414 * Flags.
415 * Otherwise, the receiver MUST silently discard the packet
416 * and take no further action. An endpoint MUST ignore the
417 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
418 */
419 if ((!sctp_test_T_bit(chunk) &&
420 (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag)) ||
421 (sctp_test_T_bit(chunk) && asoc->c.peer_vtag &&
422 (ntohl(chunk->sctp_hdr->vtag) == asoc->c.peer_vtag))) {
423 return 1;
424 }
425
426 return 0;
427 }
428
429 #endif /* __sctp_sm_h__ */
430
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