Leaked source code of windows server 2003
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/*++
Copyright (c) 1995 Microsoft Corporation
Module Name:
changebc.c
Abstract:
The change broadcast handlers
Author:
Stefan Solomon 07/11/1995
Revision History:
--*/
#include "precomp.h"
#pragma hdrstop
BOOL RTMSignaledChanges = FALSE;
BOOL RIPSignaledChanges = FALSE;
BOOL DestroyStartChangesBcastWi = FALSE;
// List of interfaces CBs which can send changes broadcasts
LIST_ENTRY IfChangesBcastList;
PWORK_ITEM
CreateChangesBcastWi(PICB icbp);
VOID
AddRouteToChangesBcast(PICB icbp,
PIPX_ROUTE IpxRoutep);
VOID
FlushChangesBcastQueue(PICB icbp);
BOOL
IsChangeBcastPacketEmpty(PUCHAR hdrp);
VOID
CreateStartChangesBcastWi(VOID)
{
PWORK_ITEM wip;
InitializeListHead(&IfChangesBcastList);
if((wip = AllocateWorkItem(START_CHANGES_BCAST_TYPE)) == NULL) {
// !!! log -> can't allocate wi
return;
}
StartWiTimer(wip, CHANGES_BCAST_TIME);
}
VOID
ProcessRTMChanges(VOID)
{
RTMSignaledChanges = TRUE;
}
VOID
ProcessRIPChanges(VOID)
{
RIPSignaledChanges = TRUE;
}
/*++
Function: StartChangesBcast
Descr: Called by the worker every 1 second
Remark: >> Called with the database lock held <<
--*/
VOID
StartChangesBcast(PWORK_ITEM wip)
{
PLIST_ENTRY lep;
PICB icbp;
PWORK_ITEM bcwip; // bcast change work item
BOOL skipit, lastmessage;
IPX_ROUTE IpxRoute;
if(DestroyStartChangesBcastWi) {
FreeWorkItem(wip);
return;
}
if(!RTMSignaledChanges && !RIPSignaledChanges) {
// re-queue in the timer queue if no changes signaled in the last 1 sec
StartWiTimer(wip, CHANGES_BCAST_TIME);
return;
}
// make a list of interfaces with
// oper state UP. This is a local list of nodes where each node points to
// an interface with state UP and lock held.
lep = IndexIfList.Flink;
while(lep != &IndexIfList)
{
icbp = CONTAINING_RECORD(lep, ICB, IfListLinkage);
if((icbp->InterfaceIndex != 0) &&
(icbp->IfStats.RipIfOperState == OPER_STATE_UP) &&
(icbp->IfConfigInfo.UpdateMode == IPX_STANDARD_UPDATE) &&
(icbp->IfConfigInfo.Supply == ADMIN_STATE_ENABLED)) {
ACQUIRE_IF_LOCK(icbp);
if((bcwip = CreateChangesBcastWi(icbp)) == NULL) {
RELEASE_IF_LOCK(icbp);
break;
}
else
{
// insert the bcast wi in the interface changes bcast queue
InsertTailList(&icbp->ChangesBcastQueue, &bcwip->Linkage);
// insert the interface CB in the global if changes bcast list
InsertTailList(&IfChangesBcastList, &icbp->AuxLinkage);
}
}
lep = lep->Flink;
}
// dequeue the RTM messages. For each message fill in the bcast changes
// wi packets according to the split horizon algorithm
if(RIPSignaledChanges) {
ACQUIRE_RIP_CHANGED_LIST_LOCK;
while(DequeueRouteChangeFromRip(&IpxRoute) == NO_ERROR) {
lep = IfChangesBcastList.Flink;
while(lep != &IfChangesBcastList)
{
icbp = CONTAINING_RECORD(lep, ICB, AuxLinkage);
AddRouteToChangesBcast(icbp, &IpxRoute);
lep = lep->Flink;
}
}
RELEASE_RIP_CHANGED_LIST_LOCK;
RIPSignaledChanges = FALSE;
}
if(RTMSignaledChanges) {
while(DequeueRouteChangeFromRtm(&IpxRoute, &skipit, &lastmessage) == NO_ERROR)
{
if(skipit) {
if(lastmessage) {
break;
}
else
{
continue;
}
}
else
{
lep = IfChangesBcastList.Flink;
while(lep != &IfChangesBcastList)
{
icbp = CONTAINING_RECORD(lep, ICB, AuxLinkage);
AddRouteToChangesBcast(icbp, &IpxRoute);
lep = lep->Flink;
}
if(lastmessage) {
break;
}
}
}
RTMSignaledChanges = FALSE;
}
// send the first bcast change wi for each if CB
while(!IsListEmpty(&IfChangesBcastList))
{
lep = RemoveHeadList(&IfChangesBcastList);
icbp = CONTAINING_RECORD(lep, ICB, AuxLinkage);
if(!IsListEmpty(&icbp->ChangesBcastQueue)) {
lep = RemoveHeadList(&icbp->ChangesBcastQueue);
bcwip = CONTAINING_RECORD(lep, WORK_ITEM, Linkage);
// check if the bcast work item packet contains at least one net entry
if(!IsChangeBcastPacketEmpty(bcwip->Packet)) {
// send the bcast change work item
if(IfRefSendSubmit(bcwip) != NO_ERROR) {
// can't send on this interface -> Flush the changes bc queue
FlushChangesBcastQueue(icbp);
// and free the current changes bcast wi
FreeWorkItem(bcwip);
}
}
else
{
FreeWorkItem(bcwip);
}
}
RELEASE_IF_LOCK(icbp);
}
// requeue the start changes bcast wi in timer queue
StartWiTimer(wip, CHANGES_BCAST_TIME);
}
/*++
Function: IfChangeBcast
Descr: if the interface is operational then
the change bcast packet work item is freed and the next change bacst
wi is dequeued from the interface change bcast queue.
else
the work item is discarded
Remark: Called with the interface lock held
--*/
VOID
IfChangeBcast(PWORK_ITEM wip)
{
PICB icbp;
PWORK_ITEM list_wip;
PLIST_ENTRY lep;
icbp = wip->icbp;
if(icbp->IfStats.RipIfOperState != OPER_STATE_UP) {
// flush the associated changes bcast queue if any
FlushChangesBcastQueue(icbp);
}
else
{
if(!IsListEmpty(&icbp->ChangesBcastQueue)) {
// send next bcast change
lep = RemoveHeadList(&icbp->ChangesBcastQueue);
list_wip = CONTAINING_RECORD(lep, WORK_ITEM, Linkage);
// submit the work item for send and increment the ref count
if(IfRefSendSubmit(list_wip) != NO_ERROR) {
// can't send on this interface -> Flush the changes bc queue
FlushChangesBcastQueue(icbp);
// and free the one we intended to send
FreeWorkItem(list_wip);
}
}
}
FreeWorkItem(wip);
}
/*++
Function: ShutdownInterfaces
Descr: called to:
1. Initiate a bcast update on all interfaces with the down routes
2. check on the bcast update termination
Remark: called with database locked
Note: Because the database is locked when this routine is called,
no interface can change its operational state while this routine
is executing
--*/
#define IsStartShutdown() \
wip->WorkItemSpecific.WIS_ShutdownInterfaces.ShutdownState == SHUTDOWN_START
#define IsCheckShutdown() \
wip->WorkItemSpecific.WIS_ShutdownInterfaces.ShutdownState == SHUTDOWN_STATUS_CHECK
#define SetCheckShutdown() \
wip->WorkItemSpecific.WIS_ShutdownInterfaces.ShutdownState = SHUTDOWN_STATUS_CHECK;
/*++
Function: ShutdownInterfaces
Descr: if START_SHUTDOWN then:
initiates if shutdown bcast on all active ifs and
removes (deletes) all inactive ifs
else
removes all ifs which finished shutdown bcast
Remark: called with database lock held
--*/
VOID
ShutdownInterfaces(PWORK_ITEM wip)
{
PLIST_ENTRY lep;
PICB icbp;
if(IsStartShutdown()) {
lep = IndexIfList.Flink;
while(lep != &IndexIfList)
{
icbp = CONTAINING_RECORD(lep, ICB, IfListLinkage);
lep = lep->Flink;
ACQUIRE_IF_LOCK(icbp);
if(icbp->IfStats.RipIfOperState != OPER_STATE_UP) {
// interface down -> delete it
Trace(CHANGEBC_TRACE, "ShutdownInterfaces: delete inactive if %d\n", icbp->InterfaceIndex);
if(!DeleteRipInterface(icbp)) {
// if cb moved on discarded list, still referenced
RELEASE_IF_LOCK(icbp);
}
}
else
{
// interface up -> remove its rip routes
DeleteAllRipRoutes(icbp->InterfaceIndex);
RELEASE_IF_LOCK(icbp);
}
}
}
else
{
SS_ASSERT(IsCheckShutdown());
lep = IndexIfList.Flink;
while(lep != &IndexIfList)
{
icbp = CONTAINING_RECORD(lep, ICB, IfListLinkage);
lep = lep->Flink;
ACQUIRE_IF_LOCK(icbp);
if(IsListEmpty(&icbp->ChangesBcastQueue)) {
Trace(CHANGEBC_TRACE, "ShutdownInterfaces: delete shut-down if %d\n", icbp->InterfaceIndex);
// interface broadcasted all changes -> delete it
if(!DeleteRipInterface(icbp)) {
// if cb moved on discarded list, still referenced
RELEASE_IF_LOCK(icbp);
}
}
else
{
// interface still broadcasting
RELEASE_IF_LOCK(icbp);
}
}
}
if(!IsListEmpty(&IndexIfList)) {
SetCheckShutdown();
StartWiTimer(wip, 5000);
}
else
{
// no more ifs up
FreeWorkItem(wip);
// signal the worker thread to stop
SetEvent(WorkerThreadObjects[TERMINATE_WORKER_EVENT]);
}
}
/*++
Function: CreateChnagesBcastWi
Descr: allocates and inits the wi and packet header for a chnages bacst
--*/
PWORK_ITEM
CreateChangesBcastWi(PICB icbp)
{
PWORK_ITEM wip;
UCHAR ripsocket[2];
if((wip = AllocateWorkItem(CHANGE_BCAST_PACKET_TYPE)) == NULL) {
return NULL;
}
// init the bcast work item
wip->icbp = icbp;
wip->AdapterIndex = icbp->AdapterBindingInfo.AdapterIndex;
PUTUSHORT2SHORT(ripsocket, IPX_RIP_SOCKET);
SetRipIpxHeader(wip->Packet,
icbp,
bcastnode,
ripsocket,
RIP_RESPONSE);
// set initial packet length
PUTUSHORT2SHORT(wip->Packet + IPXH_LENGTH, RIP_INFO); // header length + RIP op code
return wip;
}
/*++
Function: AddRouteToChangesBcast
Descr: checks if the route should be bcasted on this if
walks the list of broadcast change work items queued at the
if CB and sets the network entry in the last packet
If last packet is full allocates a new work bcast work item
--*/
VOID
AddRouteToChangesBcast(PICB icbp,
PIPX_ROUTE IpxRoutep)
{
PUCHAR hdrp;
PLIST_ENTRY lep;
USHORT pktlen;
PWORK_ITEM wip; // changes bcast wi ptr
// check if to bcast the route on this if
if(!IsRouteAdvertisable(icbp, IpxRoutep)) {
return;
}
// go to the last bcast change wi in the list
lep = icbp->ChangesBcastQueue.Blink;
if(lep == &icbp->ChangesBcastQueue) {
// changes bcast queue empty !
return;
}
wip = CONTAINING_RECORD(lep, WORK_ITEM, Linkage);
// check if the last packet is full
GETSHORT2USHORT(&pktlen, wip->Packet + IPXH_LENGTH);
if(pktlen >= RIP_PACKET_LEN) {
// we need a new packet
if((wip = CreateChangesBcastWi(icbp)) == NULL) {
// out of memory
return;
}
InsertTailList(&icbp->ChangesBcastQueue, &wip->Linkage);
GETSHORT2USHORT(&pktlen, wip->Packet + IPXH_LENGTH);
}
SetNetworkEntry(wip->Packet + pktlen, IpxRoutep, icbp->LinkTickCount);
pktlen += NE_ENTRYSIZE;
PUTUSHORT2SHORT(&wip->Packet + IPXH_LENGTH, pktlen);
}
BOOL
IsChangeBcastPacketEmpty(PUCHAR hdrp)
{
USHORT pktlen;
GETSHORT2USHORT(&pktlen, hdrp + IPXH_LENGTH);
if(pktlen > RIP_INFO) {
return FALSE;
}
else
{
return TRUE;
}
}
VOID
FlushChangesBcastQueue(PICB icbp)
{
PLIST_ENTRY lep;
PWORK_ITEM wip;
// flush the associated changes bcast queue if any
while(!IsListEmpty(&icbp->ChangesBcastQueue))
{
lep = RemoveHeadList(&icbp->ChangesBcastQueue);
wip = CONTAINING_RECORD(lep, WORK_ITEM, Linkage);
FreeWorkItem(wip);
}
}