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 <linux-sctp@vger.kernel.org>
13  *
14  * Written or modified by:
15  *   La Monte H.P. Yarroll <piggy@acm.org>
16  *   Karl Knutson <karl@athena.chicago.il.us>
17  *   Ardelle Fan <ardelle.fan@intel.com>
18  *   Sridhar Samudrala <sri@us.ibm.com>
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 
28 enum 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 
105 union 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) \
140 static inline union sctp_arg	\
141 SCTP_## name (type arg)		\
142 { union sctp_arg retval;\
143   retval.zero_all = NULL;\
144   retval.elt = arg;\
145   return retval;\
146 }
147 
SCTP_ARG_CONSTRUCTOR(I32,__s32,i32)148 SCTP_ARG_CONSTRUCTOR(I32,	__s32, i32)
149 SCTP_ARG_CONSTRUCTOR(U32,	__u32, u32)
150 SCTP_ARG_CONSTRUCTOR(BE32,	__be32, be32)
151 SCTP_ARG_CONSTRUCTOR(U16,	__u16, u16)
152 SCTP_ARG_CONSTRUCTOR(U8,	__u8, u8)
153 SCTP_ARG_CONSTRUCTOR(ERROR,     int, error)
154 SCTP_ARG_CONSTRUCTOR(PERR,      __be16, err)	/* protocol error */
155 SCTP_ARG_CONSTRUCTOR(STATE,	enum sctp_state, state)
156 SCTP_ARG_CONSTRUCTOR(TO,	enum sctp_event_timeout, to)
157 SCTP_ARG_CONSTRUCTOR(CHUNK,	struct sctp_chunk *, chunk)
158 SCTP_ARG_CONSTRUCTOR(ASOC,	struct sctp_association *, asoc)
159 SCTP_ARG_CONSTRUCTOR(TRANSPORT,	struct sctp_transport *, transport)
160 SCTP_ARG_CONSTRUCTOR(BA,	struct sctp_bind_addr *, bp)
161 SCTP_ARG_CONSTRUCTOR(PEER_INIT,	struct sctp_init_chunk *, init)
162 SCTP_ARG_CONSTRUCTOR(ULPEVENT,  struct sctp_ulpevent *, ulpevent)
163 SCTP_ARG_CONSTRUCTOR(PACKET,	struct sctp_packet *, packet)
164 SCTP_ARG_CONSTRUCTOR(SACKH,	struct sctp_sackhdr *, sackh)
165 SCTP_ARG_CONSTRUCTOR(DATAMSG,	struct sctp_datamsg *, msg)
166 
167 static inline union sctp_arg SCTP_FORCE(void)
168 {
169 	return SCTP_I32(1);
170 }
171 
SCTP_NOFORCE(void)172 static inline union sctp_arg SCTP_NOFORCE(void)
173 {
174 	return SCTP_I32(0);
175 }
176 
SCTP_NULL(void)177 static inline union sctp_arg SCTP_NULL(void)
178 {
179 	union sctp_arg retval;
180 	retval.zero_all = NULL;
181 	return retval;
182 }
183 
184 struct sctp_cmd {
185 	union sctp_arg obj;
186 	enum sctp_verb verb;
187 };
188 
189 struct 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  */
sctp_init_cmd_seq(struct sctp_cmd_seq * seq)199 static 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  */
sctp_add_cmd_sf(struct sctp_cmd_seq * seq,enum sctp_verb verb,union sctp_arg obj)213 static 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  */
sctp_next_cmd(struct sctp_cmd_seq * seq)228 static 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__ */
237