sm.h

  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 */
 41enum 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
 53typedef 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);
 60typedef void (sctp_timer_event_t) (struct timer_list *);
 61struct 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. */
 71sctp_state_fn_t sctp_sf_not_impl;
 72sctp_state_fn_t sctp_sf_bug;
 73
 74/* Prototypes for gener timer state functions. */
 75sctp_state_fn_t sctp_sf_timer_ignore;
 76
 77/* Prototypes for chunk state functions. */
 78sctp_state_fn_t sctp_sf_do_9_1_abort;
 79sctp_state_fn_t sctp_sf_cookie_wait_abort;
 80sctp_state_fn_t sctp_sf_cookie_echoed_abort;
 81sctp_state_fn_t sctp_sf_shutdown_pending_abort;
 82sctp_state_fn_t sctp_sf_shutdown_sent_abort;
 83sctp_state_fn_t sctp_sf_shutdown_ack_sent_abort;
 84sctp_state_fn_t sctp_sf_do_5_1B_init;
 85sctp_state_fn_t sctp_sf_do_5_1C_ack;
 86sctp_state_fn_t sctp_sf_do_5_1D_ce;
 87sctp_state_fn_t sctp_sf_do_5_1E_ca;
 88sctp_state_fn_t sctp_sf_do_4_C;
 89sctp_state_fn_t sctp_sf_eat_data_6_2;
 90sctp_state_fn_t sctp_sf_eat_data_fast_4_4;
 91sctp_state_fn_t sctp_sf_eat_sack_6_2;
 92sctp_state_fn_t sctp_sf_operr_notify;
 93sctp_state_fn_t sctp_sf_t1_init_timer_expire;
 94sctp_state_fn_t sctp_sf_t1_cookie_timer_expire;
 95sctp_state_fn_t sctp_sf_t2_timer_expire;
 96sctp_state_fn_t sctp_sf_t4_timer_expire;
 97sctp_state_fn_t sctp_sf_t5_timer_expire;
 98sctp_state_fn_t sctp_sf_sendbeat_8_3;
 99sctp_state_fn_t sctp_sf_beat_8_3;
100sctp_state_fn_t sctp_sf_backbeat_8_3;
101sctp_state_fn_t sctp_sf_do_9_2_final;
102sctp_state_fn_t sctp_sf_do_9_2_shutdown;
103sctp_state_fn_t sctp_sf_do_9_2_shut_ctsn;
104sctp_state_fn_t sctp_sf_do_ecn_cwr;
105sctp_state_fn_t sctp_sf_do_ecne;
106sctp_state_fn_t sctp_sf_ootb;
107sctp_state_fn_t sctp_sf_pdiscard;
108sctp_state_fn_t sctp_sf_violation;
109sctp_state_fn_t sctp_sf_discard_chunk;
110sctp_state_fn_t sctp_sf_do_5_2_1_siminit;
111sctp_state_fn_t sctp_sf_do_5_2_2_dupinit;
112sctp_state_fn_t sctp_sf_do_5_2_3_initack;
113sctp_state_fn_t sctp_sf_do_5_2_4_dupcook;
114sctp_state_fn_t sctp_sf_unk_chunk;
115sctp_state_fn_t sctp_sf_do_8_5_1_E_sa;
116sctp_state_fn_t sctp_sf_cookie_echoed_err;
117sctp_state_fn_t sctp_sf_do_asconf;
118sctp_state_fn_t sctp_sf_do_asconf_ack;
119sctp_state_fn_t sctp_sf_do_reconf;
120sctp_state_fn_t sctp_sf_do_9_2_reshutack;
121sctp_state_fn_t sctp_sf_eat_fwd_tsn;
122sctp_state_fn_t sctp_sf_eat_fwd_tsn_fast;
123sctp_state_fn_t sctp_sf_eat_auth;
124
125/* Prototypes for primitive event state functions.  */
126sctp_state_fn_t sctp_sf_do_prm_asoc;
127sctp_state_fn_t sctp_sf_do_prm_send;
128sctp_state_fn_t sctp_sf_do_9_2_prm_shutdown;
129sctp_state_fn_t sctp_sf_cookie_wait_prm_shutdown;
130sctp_state_fn_t sctp_sf_cookie_echoed_prm_shutdown;
131sctp_state_fn_t sctp_sf_do_9_1_prm_abort;
132sctp_state_fn_t sctp_sf_cookie_wait_prm_abort;
133sctp_state_fn_t sctp_sf_cookie_echoed_prm_abort;
134sctp_state_fn_t sctp_sf_shutdown_pending_prm_abort;
135sctp_state_fn_t sctp_sf_shutdown_sent_prm_abort;
136sctp_state_fn_t sctp_sf_shutdown_ack_sent_prm_abort;
137sctp_state_fn_t sctp_sf_error_closed;
138sctp_state_fn_t sctp_sf_error_shutdown;
139sctp_state_fn_t sctp_sf_ignore_primitive;
140sctp_state_fn_t sctp_sf_do_prm_requestheartbeat;
141sctp_state_fn_t sctp_sf_do_prm_asconf;
142sctp_state_fn_t sctp_sf_do_prm_reconf;
143
144/* Prototypes for other event state functions.  */
145sctp_state_fn_t sctp_sf_do_no_pending_tsn;
146sctp_state_fn_t sctp_sf_do_9_2_start_shutdown;
147sctp_state_fn_t sctp_sf_do_9_2_shutdown_ack;
148sctp_state_fn_t sctp_sf_ignore_other;
149sctp_state_fn_t sctp_sf_cookie_wait_icmp_abort;
150
151/* Prototypes for timeout event state functions.  */
152sctp_state_fn_t sctp_sf_do_6_3_3_rtx;
153sctp_state_fn_t sctp_sf_send_reconf;
154sctp_state_fn_t sctp_sf_send_probe;
155sctp_state_fn_t sctp_sf_do_6_2_sack;
156sctp_state_fn_t sctp_sf_autoclose_timer_expire;
157
158/* Prototypes for utility support functions.  */
159const 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);
164struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *,
165					     struct sctp_chunk *,
166					     gfp_t gfp);
167
168/* Prototypes for chunk-building functions.  */
169struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc,
170				  const struct sctp_bind_addr *bp,
171				  gfp_t gfp, int vparam_len);
172struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc,
173				      const struct sctp_chunk *chunk,
174				      const gfp_t gfp, const int unkparam_len);
175struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc,
176					 const struct sctp_chunk *chunk);
177struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc,
178					const struct sctp_chunk *chunk);
179struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc,
180				 const __u32 lowest_tsn,
181				 const struct sctp_chunk *chunk);
182struct sctp_chunk *sctp_make_idata(const struct sctp_association *asoc,
183				   __u8 flags, int paylen, gfp_t gfp);
184struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc,
185				     __u32 new_cum_tsn, size_t nstreams,
186				     struct sctp_ifwdtsn_skip *skiplist);
187struct sctp_chunk *sctp_make_datafrag_empty(const struct sctp_association *asoc,
188					    const struct sctp_sndrcvinfo *sinfo,
189					    int len, __u8 flags, gfp_t gfp);
190struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc,
191				  const __u32 lowest_tsn);
192struct sctp_chunk *sctp_make_sack(struct sctp_association *asoc);
193struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,
194				      const struct sctp_chunk *chunk);
195struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc,
196					  const struct sctp_chunk *chunk);
197struct sctp_chunk *sctp_make_shutdown_complete(
198					const struct sctp_association *asoc,
199					const struct sctp_chunk *chunk);
200int sctp_init_cause(struct sctp_chunk *chunk, __be16 cause, size_t paylen);
201struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc,
202				   const struct sctp_chunk *chunk,
203				   const size_t hint);
204struct sctp_chunk *sctp_make_abort_no_data(const struct sctp_association *asoc,
205					   const struct sctp_chunk *chunk,
206					   __u32 tsn);
207struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc,
208					struct msghdr *msg, size_t msg_len);
209struct sctp_chunk *sctp_make_abort_violation(
210					const struct sctp_association *asoc,
211					const struct sctp_chunk *chunk,
212					const __u8 *payload,
213					const size_t paylen);
214struct sctp_chunk *sctp_make_violation_paramlen(
215					const struct sctp_association *asoc,
216					const struct sctp_chunk *chunk,
217					struct sctp_paramhdr *param);
218struct sctp_chunk *sctp_make_violation_max_retrans(
219					const struct sctp_association *asoc,
220					const struct sctp_chunk *chunk);
221struct sctp_chunk *sctp_make_new_encap_port(
222					const struct sctp_association *asoc,
223					const struct sctp_chunk *chunk);
224struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc,
225				       const struct sctp_transport *transport,
226				       __u32 probe_size);
227struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc,
228					   const struct sctp_chunk *chunk,
229					   const void *payload,
230					   const size_t paylen);
231struct sctp_chunk *sctp_make_pad(const struct sctp_association *asoc, int len);
232struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc,
233				      const struct sctp_chunk *chunk,
234				      __be16 cause_code, const void *payload,
235				      size_t paylen, size_t reserve_tail);
236
237struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc,
238					      union sctp_addr *laddr,
239					      struct sockaddr *addrs,
240					      int addrcnt, __be16 flags);
241struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
242					     union sctp_addr *addr);
243bool sctp_verify_asconf(const struct sctp_association *asoc,
244			struct sctp_chunk *chunk, bool addr_param_needed,
245			struct sctp_paramhdr **errp);
246struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
247				       struct sctp_chunk *asconf);
248int sctp_process_asconf_ack(struct sctp_association *asoc,
249			    struct sctp_chunk *asconf_ack);
250struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
251				    __u32 new_cum_tsn, size_t nstreams,
252				    struct sctp_fwdtsn_skip *skiplist);
253struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc,
254				  __u16 key_id);
255struct sctp_chunk *sctp_make_strreset_req(const struct sctp_association *asoc,
256					  __u16 stream_num, __be16 *stream_list,
257					  bool out, bool in);
258struct sctp_chunk *sctp_make_strreset_tsnreq(
259					const struct sctp_association *asoc);
260struct sctp_chunk *sctp_make_strreset_addstrm(
261					const struct sctp_association *asoc,
262					__u16 out, __u16 in);
263struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc,
264					   __u32 result, __u32 sn);
265struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc,
266					      __u32 result, __u32 sn,
267					      __u32 sender_tsn,
268					      __u32 receiver_tsn);
269bool sctp_verify_reconf(const struct sctp_association *asoc,
270			struct sctp_chunk *chunk,
271			struct sctp_paramhdr **errp);
272void sctp_chunk_assign_tsn(struct sctp_chunk *chunk);
273void sctp_chunk_assign_ssn(struct sctp_chunk *chunk);
274
275/* Prototypes for stream-processing functions.  */
276struct sctp_chunk *sctp_process_strreset_outreq(
277				struct sctp_association *asoc,
278				union sctp_params param,
279				struct sctp_ulpevent **evp);
280struct sctp_chunk *sctp_process_strreset_inreq(
281				struct sctp_association *asoc,
282				union sctp_params param,
283				struct sctp_ulpevent **evp);
284struct sctp_chunk *sctp_process_strreset_tsnreq(
285				struct sctp_association *asoc,
286				union sctp_params param,
287				struct sctp_ulpevent **evp);
288struct sctp_chunk *sctp_process_strreset_addstrm_out(
289				struct sctp_association *asoc,
290				union sctp_params param,
291				struct sctp_ulpevent **evp);
292struct sctp_chunk *sctp_process_strreset_addstrm_in(
293				struct sctp_association *asoc,
294				union sctp_params param,
295				struct sctp_ulpevent **evp);
296struct sctp_chunk *sctp_process_strreset_resp(
297				struct sctp_association *asoc,
298				union sctp_params param,
299				struct sctp_ulpevent **evp);
300
301/* Prototypes for statetable processing. */
302
303int sctp_do_sm(struct net *net, enum sctp_event_type event_type,
304	       union sctp_subtype subtype, enum sctp_state state,
305	       struct sctp_endpoint *ep, struct sctp_association *asoc,
306	       void *event_arg, gfp_t gfp);
307
308/* 2nd level prototypes */
309void sctp_generate_t3_rtx_event(struct timer_list *t);
310void sctp_generate_heartbeat_event(struct timer_list *t);
311void sctp_generate_reconf_event(struct timer_list *t);
312void sctp_generate_probe_event(struct timer_list *t);
313void sctp_generate_proto_unreach_event(struct timer_list *t);
314
315void sctp_ootb_pkt_free(struct sctp_packet *packet);
316
317struct sctp_association *sctp_unpack_cookie(
318					const struct sctp_endpoint *ep,
319					const struct sctp_association *asoc,
320					struct sctp_chunk *chunk,
321					gfp_t gfp, int *err,
322					struct sctp_chunk **err_chk_p);
323
324/* 3rd level prototypes */
325__u32 sctp_generate_tag(const struct sctp_endpoint *ep);
326__u32 sctp_generate_tsn(const struct sctp_endpoint *ep);
327
328/* Extern declarations for major data structures.  */
329extern sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES];
330
331
332/* Get the size of a DATA chunk payload. */
333static inline __u16 sctp_data_size(struct sctp_chunk *chunk)
334{
335	__u16 size;
336
337	size = ntohs(chunk->chunk_hdr->length);
338	size -= sctp_datachk_len(&chunk->asoc->stream);
339
340	return size;
341}
342
343/* Compare two TSNs */
344#define TSN_lt(a,b)	\
345	(typecheck(__u32, a) && \
346	 typecheck(__u32, b) && \
347	 ((__s32)((a) - (b)) < 0))
348
349#define TSN_lte(a,b)	\
350	(typecheck(__u32, a) && \
351	 typecheck(__u32, b) && \
352	 ((__s32)((a) - (b)) <= 0))
353
354/* Compare two MIDs */
355#define MID_lt(a, b)	\
356	(typecheck(__u32, a) && \
357	 typecheck(__u32, b) && \
358	 ((__s32)((a) - (b)) < 0))
359
360/* Compare two SSNs */
361#define SSN_lt(a,b)		\
362	(typecheck(__u16, a) && \
363	 typecheck(__u16, b) && \
364	 ((__s16)((a) - (b)) < 0))
365
366/* ADDIP 3.1.1 */
367#define ADDIP_SERIAL_gte(a,b)	\
368	(typecheck(__u32, a) && \
369	 typecheck(__u32, b) && \
370	 ((__s32)((b) - (a)) <= 0))
371
372/* Check VTAG of the packet matches the sender's own tag. */
373static inline int
374sctp_vtag_verify(const struct sctp_chunk *chunk,
375		 const struct sctp_association *asoc)
376{
377	/* RFC 2960 Sec 8.5 When receiving an SCTP packet, the endpoint
378	 * MUST ensure that the value in the Verification Tag field of
379	 * the received SCTP packet matches its own Tag. If the received
380	 * Verification Tag value does not match the receiver's own
381	 * tag value, the receiver shall silently discard the packet...
382	 */
383	if (ntohl(chunk->sctp_hdr->vtag) != asoc->c.my_vtag)
384		return 0;
385
386	chunk->transport->encap_port = SCTP_INPUT_CB(chunk->skb)->encap_port;
387	return 1;
388}
389
390/* Check VTAG of the packet matches the sender's own tag and the T bit is
391 * not set, OR its peer's tag and the T bit is set in the Chunk Flags.
392 */
393static inline int
394sctp_vtag_verify_either(const struct sctp_chunk *chunk,
395			const struct sctp_association *asoc)
396{
397        /* RFC 2960 Section 8.5.1, sctpimpguide Section 2.41
398	 *
399	 * B) The receiver of a ABORT MUST accept the packet
400	 *    if the Verification Tag field of the packet matches its own tag
401	 *    and the T bit is not set
402	 *    OR
403	 *    it is set to its peer's tag and the T bit is set in the Chunk
404	 *    Flags.
405	 *    Otherwise, the receiver MUST silently discard the packet
406	 *    and take no further action.
407	 *
408	 * C) The receiver of a SHUTDOWN COMPLETE shall accept the packet
409	 *    if the Verification Tag field of the packet matches its own tag
410	 *    and the T bit is not set
411	 *    OR
412	 *    it is set to its peer's tag and the T bit is set in the Chunk
413	 *    Flags.
414	 *    Otherwise, the receiver MUST silently discard the packet
415	 *    and take no further action.  An endpoint MUST ignore the
416	 *    SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
417	 */
418        if ((!sctp_test_T_bit(chunk) &&
419             (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag)) ||
420	    (sctp_test_T_bit(chunk) && asoc->c.peer_vtag &&
421	     (ntohl(chunk->sctp_hdr->vtag) == asoc->c.peer_vtag))) {
422                return 1;
423	}
424
425	return 0;
426}
427
428#endif /* __sctp_sm_h__ */