cid.c

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/*++
 
Module Name:
 
    cid.c
 
Purpose:
 
    This translation unit contains the implementation of client IDS of processes and threads. (PID/TID)
 
Author:
 
    slep (Matanel) 2025.
 
Revision History:
 
--*/
 
#include "../../includes/ps.h"
#include "../../includes/ob.h"
#include "../../includes/ht.h"
#include "../../assert.h"
 
PHANDLE_TABLE PspCidTable = NULL; // The main table.
 
void
PsInitializeCidTable(
    void
)
 
/*++
 
    Routine description:
 
        Initializes the CID Table.
 
    Arguments:
 
        None.
 
    Return Values:
 
        None, on failure it bugchecks.
 
--*/
 
{
    PspCidTable = HtCreateHandleTable(NULL);
    assert(PspCidTable != NULL);
    if (!PspCidTable) MeBugCheck(CID_TABLE_NULL);
 
    // Claim the first handle, HANDLE 4 (pid) is the PID of the SystemProcess, it must not be used.
    HtCreateHandle(PspCidTable, &PsInitialSystemProcess, MT_PROCESS_ALL_ACCESS);
 
    // Set the system process's handle table to the CID Table.
}
 
HANDLE
PsAllocateProcessId(
    IN  PEPROCESS Process
)
 
/*++
 
    Routine description:
 
        Creates a PID for the specified Process.
 
    Arguments:
 
        [IN]    PEPROCESS Process - The process to create the PID for.
 
    Return Values:
 
        The HANDLE (pid) for the process.
 
--*/
 
{
    // Basically, return the handle from the PspCidTable.
    // The PID/TID is a NULL access, it is only used to identify a process
    // But to NOT authenticate it, routines like MtOpenProcess (future) would check the HANDLE of a process itself
    // (e.g PspCreateProcess returns it), but not the PID, dumbo bumbo.
    return HtCreateHandle(PspCidTable, (void*)Process, 0);
}
 
HANDLE
PsAllocateThreadId(
    IN  PETHREAD Thread
)
 
/*++
 
    Routine description:
 
        Creates a TID for the specified thread.
 
    Arguments:
 
        [IN]    PETHREAD Thread - The thread to create the TID for.
 
    Return Values:
 
        The HANDLE (tid) for the thread.
 
--*/
 
{
    return HtCreateHandle(PspCidTable, (void*)Thread, 0);
}
 
PEPROCESS
PsLookupProcessByProcessId(
    IN HANDLE ProcessId
)
 
/*++
 
    Routine description:
 
        Finds the process associated with the PID given.
 
    Arguments:
 
        [IN]    HANDLE ProcessId - The PID of the process.
 
    Return Values:
 
        Pointer to Process associated with the PID, or NULL if none.
 
--*/
 
{
    return HtGetObject(PspCidTable, ProcessId, NULL);
}
 
PETHREAD
PsLookupThreadByThreadId(
    IN HANDLE ThreadId
)
 
/*++
 
    Routine description:
 
        Finds the thread associated with the TID given.
 
    Arguments:
 
        [IN]    HANDLE ThreadId - The TID of the thread.
 
    Return Values:
 
        Pointer to Thread associated with the TID, or NULL if none.
 
--*/
 
{
    return HtGetObject(PspCidTable, ThreadId, NULL);
}
 
void
PsFreeCid(
    IN HANDLE Cid
)
 
/*++
 
    Routine description:
 
        Frees the CID (PID,TID)
 
    Arguments:
 
        [IN]    HANDLE Cid - CID Allocated.
 
    Return Values:
 
        None.
 
--*/
 
{
    HtDeleteHandle(PspCidTable, Cid);
}