command.h

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/* SCTP kernel Implementation
 * (C) Copyright IBM Corp. 2001, 2004
 * Copyright (C) 1999-2001 Cisco, Motorola
 *
 * This file is part of the SCTP kernel implementation
 *
 * These are the definitions needed for the command object.
 *
 * This SCTP implementation  is free software;
 * you can redistribute it and/or modify it under the terms of
 * the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This SCTP implementation  is distributed in the hope that it
 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
 *                 ************************
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with GNU CC; see the file COPYING.  If not, write to
 * the Free Software Foundation, 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 * Please send any bug reports or fixes you make to one of the
 * following email addresses:
 *
 * La Monte H.P. Yarroll <[email protected]>
 * Karl Knutson <[email protected]>
 * Ardelle Fan <[email protected]>
 * Sridhar Samudrala <[email protected]>
 *
 * Any bugs reported given to us we will try to fix... any fixes shared will
 * be incorporated into the next SCTP release.
 */


#ifndef __net_sctp_command_h__
#define __net_sctp_command_h__

#include <net/sctp/constants.h>
#include <net/sctp/structs.h>


typedef enum {
    SCTP_CMD_NOP = 0,   /* Do nothing. */
    SCTP_CMD_NEW_ASOC,  /* Register a new association.  */
    SCTP_CMD_DELETE_TCB,    /* Delete the current association. */
    SCTP_CMD_NEW_STATE, /* Enter a new state.  */
    SCTP_CMD_REPORT_TSN,    /* Record the arrival of a TSN.  */
    SCTP_CMD_GEN_SACK,  /* Send a Selective ACK (maybe).  */
    SCTP_CMD_PROCESS_SACK,  /* Process an inbound SACK.  */
    SCTP_CMD_GEN_INIT_ACK,  /* Generate an INIT ACK chunk.  */
    SCTP_CMD_PEER_INIT, /* Process a INIT from the peer.  */
    SCTP_CMD_GEN_COOKIE_ECHO, /* Generate a COOKIE ECHO chunk. */
    SCTP_CMD_CHUNK_ULP, /* Send a chunk to the sockets layer.  */
    SCTP_CMD_EVENT_ULP, /* Send a notification to the sockets layer. */
    SCTP_CMD_REPLY,     /* Send a chunk to our peer.  */
    SCTP_CMD_SEND_PKT,  /* Send a full packet to our peer.  */
    SCTP_CMD_RETRAN,    /* Mark a transport for retransmission.  */
    SCTP_CMD_ECN_CE,        /* Do delayed CE processing.   */
    SCTP_CMD_ECN_ECNE,  /* Do delayed ECNE processing. */
    SCTP_CMD_ECN_CWR,   /* Do delayed CWR processing.  */
    SCTP_CMD_TIMER_START,   /* Start a timer.  */
    SCTP_CMD_TIMER_START_ONCE, /* Start a timer once */
    SCTP_CMD_TIMER_RESTART, /* Restart a timer. */
    SCTP_CMD_TIMER_STOP,    /* Stop a timer. */
    SCTP_CMD_INIT_CHOOSE_TRANSPORT, /* Choose transport for an INIT. */
    SCTP_CMD_INIT_COUNTER_RESET, /* Reset init counter. */
    SCTP_CMD_INIT_COUNTER_INC,   /* Increment init counter. */
    SCTP_CMD_INIT_RESTART,  /* High level, do init timer work. */
    SCTP_CMD_COOKIEECHO_RESTART,  /* High level, do cookie-echo timer work. */
    SCTP_CMD_INIT_FAILED,   /* High level, do init failure work. */
    SCTP_CMD_REPORT_DUP,    /* Report a duplicate TSN.  */
    SCTP_CMD_STRIKE,    /* Mark a strike against a transport.  */
    SCTP_CMD_HB_TIMERS_START,    /* Start the heartbeat timers. */
    SCTP_CMD_HB_TIMER_UPDATE,    /* Update a heartbeat timers.  */
    SCTP_CMD_HB_TIMERS_STOP,     /* Stop the heartbeat timers.  */
    SCTP_CMD_TRANSPORT_HB_SENT,  /* Reset the status of a transport. */
    SCTP_CMD_TRANSPORT_IDLE,     /* Do manipulations on idle transport */
    SCTP_CMD_TRANSPORT_ON,       /* Mark the transport as active. */
    SCTP_CMD_REPORT_ERROR,   /* Pass this error back out of the sm. */
    SCTP_CMD_REPORT_BAD_TAG, /* Verification tags didn't match. */
    SCTP_CMD_PROCESS_CTSN,   /* Sideeffect from shutdown. */
    SCTP_CMD_ASSOC_FAILED,   /* Handle association failure. */
    SCTP_CMD_DISCARD_PACKET, /* Discard the whole packet. */
    SCTP_CMD_GEN_SHUTDOWN,   /* Generate a SHUTDOWN chunk. */
    SCTP_CMD_UPDATE_ASSOC,   /* Update association information. */
    SCTP_CMD_PURGE_OUTQUEUE, /* Purge all data waiting to be sent. */
    SCTP_CMD_SETUP_T2,       /* Hi-level, setup T2-shutdown parms.  */
    SCTP_CMD_RTO_PENDING,    /* Set transport's rto_pending. */
    SCTP_CMD_PART_DELIVER,   /* Partial data delivery considerations. */
    SCTP_CMD_RENEGE,         /* Renege data on an association. */
    SCTP_CMD_SETUP_T4,   /* ADDIP, setup T4 RTO timer parms. */
    SCTP_CMD_PROCESS_OPERR,  /* Process an ERROR chunk. */
    SCTP_CMD_REPORT_FWDTSN,  /* Report new cumulative TSN Ack. */
    SCTP_CMD_PROCESS_FWDTSN, /* Skips were reported, so process further. */
    SCTP_CMD_CLEAR_INIT_TAG, /* Clears association peer's inittag. */
    SCTP_CMD_DEL_NON_PRIMARY, /* Removes non-primary peer transports. */
    SCTP_CMD_T3_RTX_TIMERS_STOP, /* Stops T3-rtx pending timers */
    SCTP_CMD_FORCE_PRIM_RETRAN,  /* Forces retrans. over primary path. */
    SCTP_CMD_SET_SK_ERR,     /* Set sk_err */
    SCTP_CMD_ASSOC_CHANGE,   /* generate and send assoc_change event */
    SCTP_CMD_ADAPTATION_IND, /* generate and send adaptation event */
    SCTP_CMD_ASSOC_SHKEY,    /* generate the association shared keys */
    SCTP_CMD_T1_RETRAN,  /* Mark for retransmission after T1 timeout  */
    SCTP_CMD_UPDATE_INITTAG, /* Update peer inittag */
    SCTP_CMD_SEND_MSG,   /* Send the whole use message */
    SCTP_CMD_SEND_NEXT_ASCONF, /* Send the next ASCONF after ACK */
    SCTP_CMD_PURGE_ASCONF_QUEUE, /* Purge all asconf queues.*/
    SCTP_CMD_SET_ASOC,   /* Restore association context */
    SCTP_CMD_LAST
} sctp_verb_t;

/* How many commands can you put in an sctp_cmd_seq_t?
 * This is a rather arbitrary number, ideally derived from a careful
 * analysis of the state functions, but in reality just taken from
 * thin air in the hopes othat we don't trigger a kernel panic.
 */
#define SCTP_MAX_NUM_COMMANDS 14

typedef union {
    __s32 i32;
    __u32 u32;
    __be32 be32;
    __u16 u16;
    __u8 u8;
    int error;
    __be16 err;
    sctp_state_t state;
    sctp_event_timeout_t to;
    unsigned long zero;
    void *ptr;
    struct sctp_chunk *chunk;
    struct sctp_association *asoc;
    struct sctp_transport *transport;
    struct sctp_bind_addr *bp;
    sctp_init_chunk_t *init;
    struct sctp_ulpevent *ulpevent;
    struct sctp_packet *packet;
    sctp_sackhdr_t *sackh;
    struct sctp_datamsg *msg;
} sctp_arg_t;

/* We are simulating ML type constructors here.
 *
 * SCTP_ARG_CONSTRUCTOR(NAME, TYPE, ELT) builds a function called
 * SCTP_NAME() which takes an argument of type TYPE and returns an
 * sctp_arg_t.  It does this by inserting the sole argument into the
 * ELT union element of a local sctp_arg_t.
 *
 * E.g., SCTP_ARG_CONSTRUCTOR(I32, __s32, i32) builds SCTP_I32(arg),
 * which takes an __s32 and returns a sctp_arg_t containing the
 * __s32.  So, after foo = SCTP_I32(arg), foo.i32 == arg.
 */
static inline sctp_arg_t SCTP_NULL(void)
{
    sctp_arg_t retval; retval.ptr = NULL; return retval;
}
static inline sctp_arg_t SCTP_NOFORCE(void)
{
    sctp_arg_t retval = {.zero = 0UL}; retval.i32 = 0; return retval;
}
static inline sctp_arg_t SCTP_FORCE(void)
{
    sctp_arg_t retval = {.zero = 0UL}; retval.i32 = 1; return retval;
}

#define SCTP_ARG_CONSTRUCTOR(name, type, elt) \
static inline sctp_arg_t    \
SCTP_## name (type arg)     \
{ sctp_arg_t retval = {.zero = 0UL}; retval.elt = arg; return retval; }

SCTP_ARG_CONSTRUCTOR(I32,   __s32, i32)
SCTP_ARG_CONSTRUCTOR(U32,   __u32, u32)
SCTP_ARG_CONSTRUCTOR(BE32,  __be32, be32)
SCTP_ARG_CONSTRUCTOR(U16,   __u16, u16)
SCTP_ARG_CONSTRUCTOR(U8,    __u8, u8)
SCTP_ARG_CONSTRUCTOR(ERROR,     int, error)
SCTP_ARG_CONSTRUCTOR(PERR,      __be16, err)    /* protocol error */
SCTP_ARG_CONSTRUCTOR(STATE, sctp_state_t, state)
SCTP_ARG_CONSTRUCTOR(TO,    sctp_event_timeout_t, to)
SCTP_ARG_CONSTRUCTOR(PTR,   void *, ptr)
SCTP_ARG_CONSTRUCTOR(CHUNK, struct sctp_chunk *, chunk)
SCTP_ARG_CONSTRUCTOR(ASOC,  struct sctp_association *, asoc)
SCTP_ARG_CONSTRUCTOR(TRANSPORT, struct sctp_transport *, transport)
SCTP_ARG_CONSTRUCTOR(BA,    struct sctp_bind_addr *, bp)
SCTP_ARG_CONSTRUCTOR(PEER_INIT, sctp_init_chunk_t *, init)
SCTP_ARG_CONSTRUCTOR(ULPEVENT,  struct sctp_ulpevent *, ulpevent)
SCTP_ARG_CONSTRUCTOR(PACKET,    struct sctp_packet *, packet)
SCTP_ARG_CONSTRUCTOR(SACKH, sctp_sackhdr_t *, sackh)
SCTP_ARG_CONSTRUCTOR(DATAMSG,   struct sctp_datamsg *, msg)

typedef struct {
    sctp_arg_t obj;
    sctp_verb_t verb;
} sctp_cmd_t;

typedef struct {
    sctp_cmd_t cmds[SCTP_MAX_NUM_COMMANDS];
    __u8 next_free_slot;
    __u8 next_cmd;
} sctp_cmd_seq_t;


/* Initialize a block of memory as a command sequence.
 * Return 0 if the initialization fails.
 */
int sctp_init_cmd_seq(sctp_cmd_seq_t *seq);

/* Add a command to an sctp_cmd_seq_t.
 *
 * Use the SCTP_* constructors defined by SCTP_ARG_CONSTRUCTOR() above
 * to wrap data which goes in the obj argument.
 */
void sctp_add_cmd_sf(sctp_cmd_seq_t *seq, sctp_verb_t verb, sctp_arg_t obj);

/* Return the next command structure in an sctp_cmd_seq.
 * Return NULL at the end of the sequence.
 */
sctp_cmd_t *sctp_next_cmd(sctp_cmd_seq_t *seq);

#endif /* __net_sctp_command_h__ */