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1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/* SCTP kernel Implementation
3 * (C) Copyright IBM Corp. 2001, 2004
4 * Copyright (C) 1999-2001 Cisco, Motorola
5 *
6 * This file is part of the SCTP kernel implementation
7 *
8 * These are the definitions needed for the command object.
9 *
10 * Please send any bug reports or fixes you make to the
11 * email address(es):
12 * lksctp developers <[email protected]>
13 *
14 * Written or modified by:
15 * La Monte H.P. Yarroll <[email protected]>
16 * Karl Knutson <[email protected]>
17 * Ardelle Fan <[email protected]>
18 * Sridhar Samudrala <[email protected]>
19 */
20
21#ifndef __net_sctp_command_h__
22#define __net_sctp_command_h__
23
24#include <net/sctp/constants.h>
25#include <net/sctp/structs.h>
26
27
28enum sctp_verb {
29 SCTP_CMD_NOP = 0, /* Do nothing. */
30 SCTP_CMD_NEW_ASOC, /* Register a new association. */
31 SCTP_CMD_DELETE_TCB, /* Delete the current association. */
32 SCTP_CMD_NEW_STATE, /* Enter a new state. */
33 SCTP_CMD_REPORT_TSN, /* Record the arrival of a TSN. */
34 SCTP_CMD_GEN_SACK, /* Send a Selective ACK (maybe). */
35 SCTP_CMD_PROCESS_SACK, /* Process an inbound SACK. */
36 SCTP_CMD_GEN_INIT_ACK, /* Generate an INIT ACK chunk. */
37 SCTP_CMD_PEER_INIT, /* Process a INIT from the peer. */
38 SCTP_CMD_GEN_COOKIE_ECHO, /* Generate a COOKIE ECHO chunk. */
39 SCTP_CMD_CHUNK_ULP, /* Send a chunk to the sockets layer. */
40 SCTP_CMD_EVENT_ULP, /* Send a notification to the sockets layer. */
41 SCTP_CMD_REPLY, /* Send a chunk to our peer. */
42 SCTP_CMD_SEND_PKT, /* Send a full packet to our peer. */
43 SCTP_CMD_RETRAN, /* Mark a transport for retransmission. */
44 SCTP_CMD_ECN_CE, /* Do delayed CE processing. */
45 SCTP_CMD_ECN_ECNE, /* Do delayed ECNE processing. */
46 SCTP_CMD_ECN_CWR, /* Do delayed CWR processing. */
47 SCTP_CMD_TIMER_START, /* Start a timer. */
48 SCTP_CMD_TIMER_START_ONCE, /* Start a timer once */
49 SCTP_CMD_TIMER_RESTART, /* Restart a timer. */
50 SCTP_CMD_TIMER_STOP, /* Stop a timer. */
51 SCTP_CMD_INIT_CHOOSE_TRANSPORT, /* Choose transport for an INIT. */
52 SCTP_CMD_INIT_COUNTER_RESET, /* Reset init counter. */
53 SCTP_CMD_INIT_COUNTER_INC, /* Increment init counter. */
54 SCTP_CMD_INIT_RESTART, /* High level, do init timer work. */
55 SCTP_CMD_COOKIEECHO_RESTART, /* High level, do cookie-echo timer work. */
56 SCTP_CMD_INIT_FAILED, /* High level, do init failure work. */
57 SCTP_CMD_REPORT_DUP, /* Report a duplicate TSN. */
58 SCTP_CMD_STRIKE, /* Mark a strike against a transport. */
59 SCTP_CMD_HB_TIMERS_START, /* Start the heartbeat timers. */
60 SCTP_CMD_HB_TIMER_UPDATE, /* Update a heartbeat timers. */
61 SCTP_CMD_HB_TIMERS_STOP, /* Stop the heartbeat timers. */
62 SCTP_CMD_PROBE_TIMER_UPDATE, /* Update a probe timer. */
63 SCTP_CMD_TRANSPORT_HB_SENT, /* Reset the status of a transport. */
64 SCTP_CMD_TRANSPORT_IDLE, /* Do manipulations on idle transport */
65 SCTP_CMD_TRANSPORT_ON, /* Mark the transport as active. */
66 SCTP_CMD_REPORT_ERROR, /* Pass this error back out of the sm. */
67 SCTP_CMD_REPORT_BAD_TAG, /* Verification tags didn't match. */
68 SCTP_CMD_PROCESS_CTSN, /* Sideeffect from shutdown. */
69 SCTP_CMD_ASSOC_FAILED, /* Handle association failure. */
70 SCTP_CMD_DISCARD_PACKET, /* Discard the whole packet. */
71 SCTP_CMD_GEN_SHUTDOWN, /* Generate a SHUTDOWN chunk. */
72 SCTP_CMD_PURGE_OUTQUEUE, /* Purge all data waiting to be sent. */
73 SCTP_CMD_SETUP_T2, /* Hi-level, setup T2-shutdown parms. */
74 SCTP_CMD_RTO_PENDING, /* Set transport's rto_pending. */
75 SCTP_CMD_PART_DELIVER, /* Partial data delivery considerations. */
76 SCTP_CMD_RENEGE, /* Renege data on an association. */
77 SCTP_CMD_SETUP_T4, /* ADDIP, setup T4 RTO timer parms. */
78 SCTP_CMD_PROCESS_OPERR, /* Process an ERROR chunk. */
79 SCTP_CMD_REPORT_FWDTSN, /* Report new cumulative TSN Ack. */
80 SCTP_CMD_PROCESS_FWDTSN, /* Skips were reported, so process further. */
81 SCTP_CMD_CLEAR_INIT_TAG, /* Clears association peer's inittag. */
82 SCTP_CMD_DEL_NON_PRIMARY, /* Removes non-primary peer transports. */
83 SCTP_CMD_T3_RTX_TIMERS_STOP, /* Stops T3-rtx pending timers */
84 SCTP_CMD_FORCE_PRIM_RETRAN, /* Forces retrans. over primary path. */
85 SCTP_CMD_SET_SK_ERR, /* Set sk_err */
86 SCTP_CMD_ASSOC_CHANGE, /* generate and send assoc_change event */
87 SCTP_CMD_ADAPTATION_IND, /* generate and send adaptation event */
88 SCTP_CMD_PEER_NO_AUTH, /* generate and send authentication event */
89 SCTP_CMD_ASSOC_SHKEY, /* generate the association shared keys */
90 SCTP_CMD_T1_RETRAN, /* Mark for retransmission after T1 timeout */
91 SCTP_CMD_UPDATE_INITTAG, /* Update peer inittag */
92 SCTP_CMD_SEND_MSG, /* Send the whole use message */
93 SCTP_CMD_PURGE_ASCONF_QUEUE, /* Purge all asconf queues.*/
94 SCTP_CMD_SET_ASOC, /* Restore association context */
95 SCTP_CMD_LAST
96};
97
98/* How many commands can you put in an struct sctp_cmd_seq?
99 * This is a rather arbitrary number, ideally derived from a careful
100 * analysis of the state functions, but in reality just taken from
101 * thin air in the hopes othat we don't trigger a kernel panic.
102 */
103#define SCTP_MAX_NUM_COMMANDS 20
104
105union sctp_arg {
106 void *zero_all; /* Set to NULL to clear the entire union */
107 __s32 i32;
108 __u32 u32;
109 __be32 be32;
110 __u16 u16;
111 __u8 u8;
112 int error;
113 __be16 err;
114 enum sctp_state state;
115 enum sctp_event_timeout to;
116 struct sctp_chunk *chunk;
117 struct sctp_association *asoc;
118 struct sctp_transport *transport;
119 struct sctp_bind_addr *bp;
120 struct sctp_init_chunk *init;
121 struct sctp_ulpevent *ulpevent;
122 struct sctp_packet *packet;
123 struct sctp_sackhdr *sackh;
124 struct sctp_datamsg *msg;
125};
126
127/* We are simulating ML type constructors here.
128 *
129 * SCTP_ARG_CONSTRUCTOR(NAME, TYPE, ELT) builds a function called
130 * SCTP_NAME() which takes an argument of type TYPE and returns an
131 * union sctp_arg. It does this by inserting the sole argument into
132 * the ELT union element of a local union sctp_arg.
133 *
134 * E.g., SCTP_ARG_CONSTRUCTOR(I32, __s32, i32) builds SCTP_I32(arg),
135 * which takes an __s32 and returns a union sctp_arg containing the
136 * __s32. So, after foo = SCTP_I32(arg), foo.i32 == arg.
137 */
138
139#define SCTP_ARG_CONSTRUCTOR(name, type, elt) \
140static inline union sctp_arg \
141SCTP_## name (type arg) \
142{ union sctp_arg retval;\
143 retval.zero_all = NULL;\
144 retval.elt = arg;\
145 return retval;\
146}
147
148SCTP_ARG_CONSTRUCTOR(I32, __s32, i32)
149SCTP_ARG_CONSTRUCTOR(U32, __u32, u32)
150SCTP_ARG_CONSTRUCTOR(BE32, __be32, be32)
151SCTP_ARG_CONSTRUCTOR(U16, __u16, u16)
152SCTP_ARG_CONSTRUCTOR(U8, __u8, u8)
153SCTP_ARG_CONSTRUCTOR(ERROR, int, error)
154SCTP_ARG_CONSTRUCTOR(PERR, __be16, err) /* protocol error */
155SCTP_ARG_CONSTRUCTOR(STATE, enum sctp_state, state)
156SCTP_ARG_CONSTRUCTOR(TO, enum sctp_event_timeout, to)
157SCTP_ARG_CONSTRUCTOR(CHUNK, struct sctp_chunk *, chunk)
158SCTP_ARG_CONSTRUCTOR(ASOC, struct sctp_association *, asoc)
159SCTP_ARG_CONSTRUCTOR(TRANSPORT, struct sctp_transport *, transport)
160SCTP_ARG_CONSTRUCTOR(BA, struct sctp_bind_addr *, bp)
161SCTP_ARG_CONSTRUCTOR(PEER_INIT, struct sctp_init_chunk *, init)
162SCTP_ARG_CONSTRUCTOR(ULPEVENT, struct sctp_ulpevent *, ulpevent)
163SCTP_ARG_CONSTRUCTOR(PACKET, struct sctp_packet *, packet)
164SCTP_ARG_CONSTRUCTOR(SACKH, struct sctp_sackhdr *, sackh)
165SCTP_ARG_CONSTRUCTOR(DATAMSG, struct sctp_datamsg *, msg)
166
167static inline union sctp_arg SCTP_FORCE(void)
168{
169 return SCTP_I32(1);
170}
171
172static inline union sctp_arg SCTP_NOFORCE(void)
173{
174 return SCTP_I32(0);
175}
176
177static inline union sctp_arg SCTP_NULL(void)
178{
179 union sctp_arg retval;
180 retval.zero_all = NULL;
181 return retval;
182}
183
184struct sctp_cmd {
185 union sctp_arg obj;
186 enum sctp_verb verb;
187};
188
189struct sctp_cmd_seq {
190 struct sctp_cmd cmds[SCTP_MAX_NUM_COMMANDS];
191 struct sctp_cmd *last_used_slot;
192 struct sctp_cmd *next_cmd;
193};
194
195
196/* Initialize a block of memory as a command sequence.
197 * Return 0 if the initialization fails.
198 */
199static inline int sctp_init_cmd_seq(struct sctp_cmd_seq *seq)
200{
201 /* cmds[] is filled backwards to simplify the overflow BUG() check */
202 seq->last_used_slot = seq->cmds + SCTP_MAX_NUM_COMMANDS;
203 seq->next_cmd = seq->last_used_slot;
204 return 1; /* We always succeed. */
205}
206
207
208/* Add a command to an struct sctp_cmd_seq.
209 *
210 * Use the SCTP_* constructors defined by SCTP_ARG_CONSTRUCTOR() above
211 * to wrap data which goes in the obj argument.
212 */
213static inline void sctp_add_cmd_sf(struct sctp_cmd_seq *seq,
214 enum sctp_verb verb, union sctp_arg obj)
215{
216 struct sctp_cmd *cmd = seq->last_used_slot - 1;
217
218 BUG_ON(cmd < seq->cmds);
219
220 cmd->verb = verb;
221 cmd->obj = obj;
222 seq->last_used_slot = cmd;
223}
224
225/* Return the next command structure in an sctp_cmd_seq.
226 * Return NULL at the end of the sequence.
227 */
228static inline struct sctp_cmd *sctp_next_cmd(struct sctp_cmd_seq *seq)
229{
230 if (seq->next_cmd <= seq->last_used_slot)
231 return NULL;
232
233 return --seq->next_cmd;
234}
235
236#endif /* __net_sctp_command_h__ */