FreeBSD-5.3/usr.sbin/atm/scspd/scsp_hfsm.c
/*
*
* ===================================
* HARP | Host ATM Research Platform
* ===================================
*
*
* This Host ATM Research Platform ("HARP") file (the "Software") is
* made available by Network Computing Services, Inc. ("NetworkCS")
* "AS IS". NetworkCS does not provide maintenance, improvements or
* support of any kind.
*
* NETWORKCS MAKES NO WARRANTIES OR REPRESENTATIONS, EXPRESS OR IMPLIED,
* INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS FOR A PARTICULAR PURPOSE, AS TO ANY ELEMENT OF THE
* SOFTWARE OR ANY SUPPORT PROVIDED IN CONNECTION WITH THIS SOFTWARE.
* In no event shall NetworkCS be responsible for any damages, including
* but not limited to consequential damages, arising from or relating to
* any use of the Software or related support.
*
* Copyright 1994-1998 Network Computing Services, Inc.
*
* Copies of this Software may be made, however, the above copyright
* notice must be reproduced on all copies.
*
* @(#) $FreeBSD: src/usr.sbin/atm/scspd/scsp_hfsm.c,v 1.4 2002/10/10 00:32:55 alfred Exp $
*
*/
/*
* Server Cache Synchronization Protocol (SCSP) Support
* ----------------------------------------------------
*
* HELLO finite state machine
*
*/
#include <sys/types.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <net/if.h>
#include <netinet/in.h>
#include <netatm/queue.h>
#include <netatm/atm.h>
#include <netatm/atm_if.h>
#include <netatm/atm_sap.h>
#include <netatm/atm_sys.h>
#include <netatm/atm_ioctl.h>
#include <errno.h>
#include <libatm.h>
#include <stdio.h>
#include <syslog.h>
#include "scsp_msg.h"
#include "scsp_if.h"
#include "scsp_var.h"
#ifndef lint
__RCSID("@(#) $FreeBSD: src/usr.sbin/atm/scspd/scsp_hfsm.c,v 1.4 2002/10/10 00:32:55 alfred Exp $");
#endif
/*
* HELLO FSM actions
*/
#define HELLO_ACTION_CNT 7
int scsp_hello_act_00(Scsp_dcs *, Scsp_msg *);
int scsp_hello_act_01(Scsp_dcs *, Scsp_msg *);
int scsp_hello_act_02(Scsp_dcs *, Scsp_msg *);
int scsp_hello_act_03(Scsp_dcs *, Scsp_msg *);
int scsp_hello_act_04(Scsp_dcs *, Scsp_msg *);
int scsp_hello_act_05(Scsp_dcs *, Scsp_msg *);
int scsp_hello_act_06(Scsp_dcs *, Scsp_msg *);
static int (*scsp_action_vector[HELLO_ACTION_CNT])() = {
scsp_hello_act_00,
scsp_hello_act_01,
scsp_hello_act_02,
scsp_hello_act_03,
scsp_hello_act_04,
scsp_hello_act_05,
scsp_hello_act_06
};
/*
* HELLO FSM state table
*/
static int hello_state_table[SCSP_HFSM_EVENT_CNT][SCSP_HFSM_STATE_CNT] = {
/* 0 1 2 3 */
{ 1, 1, 1, 1 }, /* 0 */
{ 0, 2, 2, 2 }, /* 1 */
{ 0, 3, 3, 3 }, /* 2 */
{ 0, 0, 4, 4 }, /* 3 */
{ 0, 5, 5, 6 }, /* 4 */
};
/*
* HELLO finite state machine
*
* Arguments:
* dcsp pointer to a DCS control block for the neighbor
* event the event which has occurred
* msg pointer to received message, if there is one
*
* Returns:
* 0 success
* errno error encountered
*
*/
int
scsp_hfsm(dcsp, event, msg)
Scsp_dcs *dcsp;
int event;
Scsp_msg *msg;
{
int action, rc, state;
/*
* Select an action from the state table
*/
state = dcsp->sd_hello_state;
action = hello_state_table[event][state];
if (scsp_trace_mode & SCSP_TRACE_HFSM) {
scsp_trace("HFSM: state=%d, event=%d, action=%d\n",
state, event, action);
}
if (action >= HELLO_ACTION_CNT || action <= 0) {
scsp_log(LOG_ERR, "Hello FSM--invalid action %d; state=%d, event=%d",
action, dcsp->sd_hello_state, event);
abort();
}
/*
* Perform the selected action
*/
rc = scsp_action_vector[action](dcsp, msg);
return(rc);
}
/*
* HELLO finite state machine action 0
* Unexpected action -- log an error message
*
* Arguments:
* dcsp pointer to DCS control block
* msg pointer to received message (ignored)
*
* Returns:
* EOPNOTSUPP always returns EOPNOTSUPP
*
*/
int
scsp_hello_act_00(dcsp, msg)
Scsp_dcs *dcsp;
Scsp_msg *msg;
{
scsp_log(LOG_ERR, "Hello FSM error--unexpected action, state=%d",
dcsp->sd_hello_state);
return(EOPNOTSUPP);
}
/*
* HELLO finite state machine action 1
* VCC open -- send HELLO message, start hello timer, go to Waiting
* state
*
* Arguments:
* dcsp pointer to DCS control block
* msg pointer to received message (ignored)
*
* Returns:
* 0 success
* errno error encountered
*
*/
int
scsp_hello_act_01(dcsp, msg)
Scsp_dcs *dcsp;
Scsp_msg *msg;
{
int rc;
/*
* Cancel the VCC open timer if it's running
*/
HARP_CANCEL(&dcsp->sd_open_t);
/*
* Go to Waiting state
*/
dcsp->sd_hello_state = SCSP_HFSM_WAITING;
/*
* Send a Hello message
*/
rc = scsp_send_hello(dcsp);
if (rc == 0) {
/*
* Success--start the Hello timer
*/
HARP_TIMER(&dcsp->sd_hello_h_t, SCSP_HELLO_Interval,
scsp_hello_timeout);
}
return(rc);
}
/*
* HELLO finite state machine action 2
* VCC closed -- notify CA FSM, go to Down state, try to re-open VCC
*
* Arguments:
* dcsp pointer to DCS control block
* msg pointer to received message (ignored)
*
* Returns:
* 0 success
* errno error encountered
*
*/
int
scsp_hello_act_02(dcsp, msg)
Scsp_dcs *dcsp;
Scsp_msg *msg;
{
int rc;
/*
* Cancel any current timers
*/
HARP_CANCEL(&dcsp->sd_hello_h_t);
HARP_CANCEL(&dcsp->sd_hello_rcv_t);
/*
* Log the loss of the VCC
*/
if (dcsp->sd_hello_state > SCSP_HFSM_WAITING) {
scsp_log(LOG_ERR, "VC to %s closed",
format_atm_addr(&dcsp->sd_addr));
}
/*
* Tell the CA FSM that the conection to the DCS is lost
*/
rc = scsp_cafsm(dcsp, SCSP_CAFSM_HELLO_DOWN, (void *)0);
/*
* Go to Down state
*/
dcsp->sd_hello_state = SCSP_HFSM_DOWN;
/*
* If our ID is lower than the DCS's, wait a second before
* trying to connect. This should keep both of us from
* trying to connect at the same time, resulting in two
* VCCs being open.
*/
if (scsp_cmp_id(&dcsp->sd_server->ss_lsid,
&dcsp->sd_dcsid) < 0) {
/*
* Our ID is lower--start the VCC open timer for one
* second so we'll try to open the VCC if the DCS
* doesn't do it by then
*/
HARP_TIMER(&dcsp->sd_open_t, 1, scsp_open_timeout);
} else {
/*
* Our ID is higher--try to reopen the VCC immediately
*/
if (scsp_dcs_connect(dcsp)) {
/*
* Conncect failed -- set a timer and try
* again later
*/
HARP_TIMER(&dcsp->sd_open_t, SCSP_Open_Interval,
scsp_open_timeout);
}
}
return(0);
}
/*
* HELLO finite state machine action 3
* Hello timer expired -- send HELLO message, restart hello timer
*
* Arguments:
* dcsp pointer to DCS control block
* msg pointer to received message (ignored)
*
* Returns:
* 0 success
* errno error encountered
*
*/
int
scsp_hello_act_03(dcsp, msg)
Scsp_dcs *dcsp;
Scsp_msg *msg;
{
int rc;
/*
* Send a Hello message
*/
rc = scsp_send_hello(dcsp);
if (rc == 0) {
/*
* Success--restart the Hello timer
*/
HARP_TIMER(&dcsp->sd_hello_h_t, SCSP_HELLO_Interval,
scsp_hello_timeout);
}
return(rc);
}
/*
* HELLO finite state machine action 4
* Receive timer expired -- if we haven't received any Hellos, notify
* CA FSM and go to Waiting state; if we've received Hellos, but we
* weren't in the receiver ID list, go to Unidirectional state
*
* Arguments:
* dcsp pointer to DCS control block
* msg pointer to received message (ignored)
*
* Returns:
* 0 success
* errno error encountered
*
*/
int
scsp_hello_act_04(dcsp, msg)
Scsp_dcs *dcsp;
Scsp_msg *msg;
{
int rc = 0;
/*
* Check whether we'ver received any Hellos lately
*/
if (dcsp->sd_hello_rcvd) {
/*
* We've had Hellos since the receive timer was
* started--go to Unidirectional state
*/
dcsp->sd_hello_rcvd = 0;
dcsp->sd_hello_state = SCSP_HFSM_UNI_DIR;
} else {
/*
* We haven't seen any Hellos at all from the DCS in
* hello_interval * dead_factor seconds--go to Waiting
* state
*/
dcsp->sd_hello_state = SCSP_HFSM_WAITING;
}
/*
* Notify the CA FSM
*/
rc = scsp_cafsm(dcsp, SCSP_CAFSM_HELLO_DOWN, (void *)0);
return(rc);
}
/*
* HELLO finite state machine action 5
* Message received -- Ignore all but HELLO messages; if local server
* is in receiver list, notify CA FSM and go to Bidirectional state;
* otherwise, go to Unidirectional state
*
* Arguments:
* dcsp pointer to DCS control block
* msg pointer to received message
*
* Returns:
* 0 success
* errno error encountered
*
*/
int
scsp_hello_act_05(dcsp, msg)
Scsp_dcs *dcsp;
Scsp_msg *msg;
{
int rc;
Scsp_id *ridp;
/*
* Null message pointer means message decode failed, so
* message must have been invalid. Go to Waiting state.
*/
if (msg == (Scsp_msg *)0) {
dcsp->sd_hello_state = SCSP_HFSM_WAITING;
HARP_CANCEL(&dcsp->sd_hello_rcv_t);
return(0);
}
/*
* Ignore the message if it isn't a Hello
*/
if (msg->sc_msg_type != SCSP_HELLO_MSG) {
return(0);
}
/*
* Save relevant information about DCS, but don't let him give
* us zero for timeout values
*/
if (msg->sc_hello->hello_int) {
dcsp->sd_hello_int = msg->sc_hello->hello_int;
} else {
dcsp->sd_hello_int = 1;
}
if (msg->sc_hello->dead_factor) {
dcsp->sd_hello_df = msg->sc_hello->dead_factor;
} else {
dcsp->sd_hello_df = 1;
}
dcsp->sd_dcsid = msg->sc_hello->hello_mcp.sid;
/*
* Check the message for the local server's ID
*/
for (ridp = &msg->sc_hello->hello_mcp.rid;
ridp;
ridp = ridp->next) {
if (scsp_cmp_id(&dcsp->sd_server->ss_lsid, ridp) == 0) {
/*
* Cancel and restart the receive timer
*/
HARP_CANCEL(&dcsp->sd_hello_rcv_t);
HARP_TIMER(&dcsp->sd_hello_rcv_t,
dcsp->sd_hello_int * dcsp->sd_hello_df,
scsp_hello_rcv_timeout);
/*
* Go to Bidirectional state and notify the
* CA FSM that the connection is up
*/
dcsp->sd_hello_state = SCSP_HFSM_BI_DIR;
rc = scsp_cafsm(dcsp,
SCSP_CAFSM_HELLO_UP,
(void *)0);
return(rc);
}
}
/*
* We weren't in the receiver ID list, so go to
* Unidirectional state
*/
dcsp->sd_hello_state = SCSP_HFSM_UNI_DIR;
return(0);
}
/*
* HELLO finite state machine action 6
* Message received -- if message is not a HELLO, pass it to the CA
* FSM; otherwise, if local server is not in receiver list, notify
* CA FSM and go to Unidirectional state
*
* Arguments:
* dcsp pointer to DCS control block
* msg pointer to received message
*
* Returns:
* 0 success
* errno error encountered
*
*/
int
scsp_hello_act_06(dcsp, msg)
Scsp_dcs *dcsp;
Scsp_msg *msg;
{
int rc = 0, rcv_found;
Scsp_id *ridp;
/*
* Null message pointer means message decode failed, so
* message must have been invalid. Go to Waiting state.
*/
if (msg == (Scsp_msg *)0) {
HARP_CANCEL(&dcsp->sd_hello_rcv_t);
dcsp->sd_hello_state = SCSP_HFSM_WAITING;
rc = scsp_cafsm(dcsp, SCSP_CAFSM_HELLO_DOWN, (void *)0);
return(rc);
}
/*
* Process the message depending on its type
*/
switch(msg->sc_msg_type) {
case SCSP_CA_MSG:
rc = scsp_cafsm(dcsp, SCSP_CAFSM_CA_MSG, (void *)msg);
break;
case SCSP_CSU_REQ_MSG:
rc = scsp_cafsm(dcsp, SCSP_CAFSM_CSU_REQ, (void *)msg);
break;
case SCSP_CSU_REPLY_MSG:
rc = scsp_cafsm(dcsp, SCSP_CAFSM_CSU_REPLY,
(void *)msg);
break;
case SCSP_CSUS_MSG:
rc = scsp_cafsm(dcsp, SCSP_CAFSM_CSUS_MSG, (void *)msg);
break;
case SCSP_HELLO_MSG:
/*
* Make sure DCS info is consistent. The sender ID,
* family ID, protocol ID, and server group ID are
* checked.
*/
if (scsp_cmp_id(&msg->sc_hello->hello_mcp.sid,
&dcsp->sd_dcsid) ||
(msg->sc_hello->family_id !=
dcsp->sd_server->ss_fid) ||
(msg->sc_hello->hello_mcp.pid !=
dcsp->sd_server->ss_pid) ||
(msg->sc_hello->hello_mcp.sgid !=
dcsp->sd_server->ss_sgid)) {
/*
* Bad info--revert to waiting state
*/
HARP_CANCEL(&dcsp->sd_hello_rcv_t);
dcsp->sd_hello_state = SCSP_HFSM_WAITING;
rc = scsp_cafsm(dcsp,
SCSP_CAFSM_HELLO_DOWN,
(void *)0);
return(rc);
}
/*
* Mark the arrival of the Hello message
*/
dcsp->sd_hello_rcvd = 1;
/*
* Check the message for the local server's ID
*/
for (ridp = &msg->sc_hello->hello_mcp.rid,
rcv_found = 0;
ridp;
ridp = ridp->next) {
rcv_found = (scsp_cmp_id(ridp,
&dcsp->sd_server->ss_lsid) == 0);
}
if (rcv_found) {
/*
* The LS ID was in the list of receiver IDs--
* Reset the Hello receive timer
*/
dcsp->sd_hello_rcvd = 0;
HARP_CANCEL(&dcsp->sd_hello_rcv_t);
HARP_TIMER(&dcsp->sd_hello_rcv_t,
dcsp->sd_hello_int *
dcsp->sd_hello_df,
scsp_hello_rcv_timeout);
}
break;
}
return(rc);
}