include/net/sctp/command.h

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2 /* SCTP kernel Implementation
   3  * (C) Copyright IBM Corp. 2001, 2004
   4  * Copyright (C) 1999-2001 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_TRANSPORT_HB_SENT,  /* Reset the status of a transport. */
  63         SCTP_CMD_TRANSPORT_IDLE,     /* Do manipulations on idle transport */
  64         SCTP_CMD_TRANSPORT_ON,       /* Mark the transport as active. */
  65         SCTP_CMD_REPORT_ERROR,   /* Pass this error back out of the sm. */
  66         SCTP_CMD_REPORT_BAD_TAG, /* Verification tags didn't match. */
  67         SCTP_CMD_PROCESS_CTSN,   /* Sideeffect from shutdown. */
  68         SCTP_CMD_ASSOC_FAILED,   /* Handle association failure. */
  69         SCTP_CMD_DISCARD_PACKET, /* Discard the whole packet. */
  70         SCTP_CMD_GEN_SHUTDOWN,   /* Generate a SHUTDOWN chunk. */
  71         SCTP_CMD_UPDATE_ASSOC,   /* Update association information. */
  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
 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
 172 static inline union sctp_arg SCTP_NOFORCE(void)
 173 {
 174         return SCTP_I32(0);
 175 }
 176
 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  */
 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  */
 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  */
 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__ */