winnet.c

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/*
 * Copyright (c) 2020 Bitdefender
 * SPDX-License-Identifier: Apache-2.0
 */
#include "introcore.h"
#include "guests.h"
#include "intronet.h"
#include "winnet.h"
#include "winprocesshp.h"
#include "winpe.h"
#include "drivers.h"
#include "alerts.h"
#include "bitmask.h"
#include "structs.h"

#define TCPIP_MAX_PARTITION_CNT 0x40

#define NET_BYTE_ORDER(Word)    (((Word) >> 8) | ((Word) << 8))

#define VALID_PORT(Port)        (0 != (Port) && 49151 != (Port))

#define WINNET_LIST_ITERS_CAP 64
struct _WINNET_STATE
{
    struct _PARTITION
    {
        QWORD   Table;          
        DWORD   Count;          
        DWORD   Size;           

        BOOLEAN Found;          
    } Partition;

    struct _BITMAP
    {
        QWORD   PortAssignment; 
        QWORD   Buffer;         

        BOOLEAN Found;          
    } Bitmap;
} gWinNet;


static inline INTRO_NET_AF
IntWinNetConvertAf(
    _In_ WORD Af
    )
{
    switch (Af)
    {
    case AF_INET:
        return introNetAfIpv4;
    case AF_INET6:
        return introNetAfIpv6;
    }

    return introNetAfUnknown;
}


static INTSTATUS
IntWinNetGetAddrFam(
    _In_reads_bytes_(Size) const BYTE *Buffer,
    _In_ size_t Size,
    _Inout_ size_t *Offset,
    _Inout_ void *Context
    )
{
#define ADDR_FAM_OFFSET (gGuest.Guest64 ? (gGuest.OSVersion >= 9200 ? 0x18 : 0x14) : 0xC)

    POOL_HEADER ph;
    INTRONET_ENDPOINT *net = (INTRONET_ENDPOINT *)Context;
    size_t off;
    QWORD addr;
    INTSTATUS status;
    DWORD tag;
    WORD fam;

    *Offset = ROUND_UP(*Offset, gGuest.WordSize);

    off = *Offset;
    *Offset += gGuest.WordSize;

    if (off + gGuest.WordSize > Size)
    {
        return INT_STATUS_BUFFER_OVERFLOW;
    }

    addr = gGuest.Guest64 ? *(const QWORD *)(Buffer + off) : *(const DWORD *)(Buffer + off);

    if (ROUND_DOWN(addr, WIN_POOL_HEADER_SIZE) != addr)
    {
        return INT_STATUS_ALIGNMENT_INCONSISTENCY;
    }

    status = IntKernVirtMemRead(addr - WIN_POOL_HEADER_SIZE, WIN_POOL_HEADER_SIZE, &ph, NULL);
    if (!INT_SUCCESS(status))
    {
        return status;
    }

    tag = gGuest.Guest64 ? ph.Header64.PoolTag : ph.Header32.PoolTag;

    if (tag != POOL_TAG_INNL)
    {
        return INT_STATUS_INVALID_OBJECT_TYPE;
    }
    
    status = IntKernVirtMemRead(addr + ADDR_FAM_OFFSET, sizeof(fam), &fam, NULL);
    if (!INT_SUCCESS(status))
    {
        return status;
    }

    net->AddressFamily = IntWinNetConvertAf(fam);
    if (net->AddressFamily == introNetAfUnknown)
    {
        return INT_STATUS_INVALID_OBJECT_TYPE;
    }

    return INT_STATUS_SUCCESS;

#undef ADDR_FAM_OFFSET
}


static INTSTATUS
IntWinNetGetLocalAddr(
    _In_ QWORD Gva,
    _Out_ INTRONET_ENDPOINT *Endpoint
    )
{
    INTSTATUS status;
    QWORD addr;
    LOCAL_ADDRESS la;

    addr = FIX_GUEST_POINTER(gGuest.Guest64, Gva);
    status = IntKernVirtMemRead(addr, gGuest.Guest64 ? sizeof(la.Addr64) : sizeof(la.Addr32), &la, NULL);
    if (!INT_SUCCESS(status))
    {
        return status;
    }

    addr = gGuest.Guest64 ? la.Addr64.InAddr : la.Addr32.InAddr;
    status = IntKernVirtMemFetchWordSize(addr, &addr);
    if (!INT_SUCCESS(status))
    {
        return status;
    }

    addr = FIX_GUEST_POINTER(gGuest.Guest64, addr);
    return IntKernVirtMemRead(addr, sizeof(Endpoint->LocalAddress), &Endpoint->LocalAddress, NULL);
}


static INTSTATUS
IntWinNetGetAddrInfo(
    _In_reads_bytes_(Size) const BYTE *Buffer,
    _In_ size_t Size,
    _Inout_ size_t *Offset,
    _Inout_ void *Context
    )
{
    QWORD addr, local, remote;
    ADDRINFO ai = { 0 };
    DWORD sz;
    INTRONET_ENDPOINT *net = (INTRONET_ENDPOINT *)Context;
    size_t off;
    INTSTATUS status;

    *Offset = ROUND_UP(*Offset, gGuest.WordSize);

    if (gGuest.Guest64)
    {
        sz = sizeof(ai.Addr64);
    }
    else
    {
        sz = gGuest.OSVersion >= 9200 ? sizeof(ai.Addr32.Win8AndAbove) : sizeof(ai.Addr32.Win7);
    }

    off = *Offset;
    *Offset += gGuest.WordSize;

    if (off + gGuest.WordSize > Size)
    {
        return INT_STATUS_BUFFER_OVERFLOW;
    }
    
    addr = gGuest.Guest64 ? *(const QWORD *)(Buffer + off) : *(const DWORD *)(Buffer + off);
    status = IntKernVirtMemRead(addr, sz, &ai, NULL);
    if (!INT_SUCCESS(status))
    {
        return status;
    }

    if (gGuest.Guest64)
    {
        remote = ai.Addr64.Remote;
        local = ai.Addr64.Local;
    }
    else
    {
        remote = gGuest.OSVersion >= 9200 ? ai.Addr32.Win8AndAbove.Remote : ai.Addr32.Win7.Remote;
        local = gGuest.OSVersion >= 9200 ? ai.Addr32.Win8AndAbove.Local : ai.Addr32.Win7.Local;
    }

    status = IntKernVirtMemRead(remote, sizeof(net->RemoteAddress), &net->RemoteAddress, NULL);
    if (!INT_SUCCESS(status))
    {
        return status;
    }

    return IntWinNetGetLocalAddr(local, net);
}


static INTSTATUS
IntWinNetGetPortsAndState(
    _In_reads_bytes_(Size) const BYTE *Buffer,
    _In_ size_t Size,
    _Inout_ size_t *Offset,
    _Inout_ void *Context
    )
{
    INTSTATUS status;
    size_t off, skip;
    INTRONET_ENDPOINT *net = (INTRONET_ENDPOINT *)Context;

    *Offset = ROUND_UP(*Offset, sizeof(DWORD));

    skip = 4;
    off = *Offset;

    // Make sure we can fit both ports and the state.
    if (off + 2 * sizeof(WORD) + sizeof(DWORD) > Size)
    {
        status = INT_STATUS_BUFFER_OVERFLOW;
        goto _exit;
    }

    if (gGuest.Guest64 && IS_KERNEL_POINTER_WIN(TRUE, *(const QWORD *)(Buffer + off)))
    {
        skip = 8;
        status = INT_STATUS_INVALID_DATA_TYPE;
        goto _exit;
    }

    net->State = IntNetConvertState(*(const DWORD *)(Buffer + off));
    if (net->State == introNetStateUnknown ||
        net->State == introNetStateListening ||
        net->State == introNetStateClosed)
    {
        status = INT_STATUS_INVALID_OBJECT_TYPE;
        goto _exit;
    }

    net->LocalPort = NET_BYTE_ORDER(*(const WORD *)(Buffer + off + 4));
    net->RemotePort = NET_BYTE_ORDER(*(const WORD *)(Buffer + off + 6));

    if (!VALID_PORT(net->LocalPort) || !VALID_PORT(net->RemotePort))
    {
        status = INT_STATUS_INVALID_OBJECT_TYPE;
        goto _exit;
    }

    skip += 4;
    status = INT_STATUS_SUCCESS;

_exit:
    *Offset += skip;

    return status;
}


static INTSTATUS
IntWinNetGetOwner(
    _In_reads_bytes_(Size) const BYTE *Buffer,
    _In_ size_t Size,
    _Inout_ size_t *Offset,
    _Inout_ void *Context
    )
{
    INTRONET_ENDPOINT *net = (INTRONET_ENDPOINT *)Context;
    QWORD addr;
    size_t off;

    *Offset = ROUND_UP(*Offset, gGuest.WordSize);

    off = *Offset;
    *Offset += gGuest.WordSize;

    if (off + gGuest.WordSize > Size)
    {
        return INT_STATUS_BUFFER_OVERFLOW;
    }

    addr = gGuest.Guest64 ? *(const QWORD *)(Buffer + off) : *(const DWORD *)(Buffer + off);

    net->OwnerProcess = IntWinProcFindObjectByEprocess(addr);
    if (NULL == net->OwnerProcess)
    {
        return INT_STATUS_INVALID_OBJECT_TYPE;
    }

    return INT_STATUS_SUCCESS;
}


static INTSTATUS
IntWinNetGetListenerAddressInfo(
    _In_reads_bytes_(Size) const BYTE *Buffer,
    _In_ size_t Size,
    _Inout_ size_t *Offset,
    _Inout_ void *Context
    )
{
    INTRONET_ENDPOINT *net = (INTRONET_ENDPOINT *)Context;
    QWORD addrinfo;
    size_t off;
    INTSTATUS status;
    WORD port;

    *Offset = ROUND_UP(*Offset, gGuest.WordSize);

    off = *Offset;
    *Offset += gGuest.WordSize;

    // Make sure we can fit the both the address and address family pointers
    // and the local port, which is at an offset of 2 bytes from those pointers.
    if (off + 2ull * gGuest.WordSize + 2 + sizeof(WORD) > Size)
    {
        return INT_STATUS_BUFFER_OVERFLOW;
    }

    addrinfo = gGuest.Guest64 ? *(const QWORD *)(Buffer + off) : *(const DWORD *)(Buffer + off);
    if (0 == addrinfo)
    {
        // Handle dual stack sockets.
        if (introNetAfIpv4 == net->AddressFamily)
        {
            net->LocalAddress.Ipv4[0] = 127;
            net->LocalAddress.Ipv4[3] = 1;
        }
        else
        {
            net->LocalAddress.Ipv6[15] = 1;
        }
    }
    else
    {
        status = IntWinNetGetLocalAddr(addrinfo, net);
        if (!INT_SUCCESS(status))
        {
            return status;
        }
    }

    // Get to the next pointer.
    off += gGuest.WordSize;

    // Note that this will increase the offset.
    status = IntWinNetGetAddrFam(Buffer, Size, &off, Context);
    if (!INT_SUCCESS(status))
    {
        return status;
    }

    port = NET_BYTE_ORDER(*(const WORD *)(Buffer + off + 2));
    if (port != net->LocalPort)
    {
        return INT_STATUS_INVALID_DATA_TYPE;
    }

    net->State = introNetStateListening;

    *Offset += 2ull * gGuest.WordSize;

    return INT_STATUS_SUCCESS;
}


static INTSTATUS
IntWinNetFillTcpStruct(
    _In_ const QWORD Gva,
    _Inout_updates_(Count) INT_STRUCT_INVARIANT *Invariants,
    _In_ size_t Count,
    _In_ DWORD PoolTag,
    _In_ BOOLEAN LogErrors,
    _Inout_ INTRONET_ENDPOINT *Endpoint
    )
{
    QWORD alignedAddr;
    const POOL_HEADER *ph;
    BYTE *map;
    size_t sz, originalOffset;
    ssize_t offset;
    INTSTATUS status;

    if (!IS_KERNEL_POINTER_WIN(gGuest.Guest64, Gva))
    {
        return INT_STATUS_INVALID_PARAMETER_1;
    }

    if (NULL == Invariants)
    {
        return INT_STATUS_INVALID_PARAMETER_2;
    }

    if (0 == Count || Count > INT_STRUCT_MAX_INVARIANT_CNT)
    {
        return INT_STATUS_INVALID_PARAMETER_3;
    }

    if (NULL == Endpoint)
    {
        return INT_STATUS_INVALID_PARAMETER_5;
    }

    alignedAddr = Gva & PAGE_MASK;
    originalOffset = ROUND_DOWN(Gva & PAGE_OFFSET, WIN_POOL_HEADER_SIZE);

    status = IntVirtMemMap(alignedAddr, PAGE_SIZE, gGuest.Mm.SystemCr3, 0, &map);
    if (!INT_SUCCESS(status))
    {
        return status;
    }

    ph = NULL;
    sz = 0;
    offset = originalOffset;
    while (offset >= 0)
    {
        DWORD tag, type;

        ph = (const POOL_HEADER *)((size_t)map + offset);

        tag = gGuest.Guest64 ? ph->Header64.PoolTag : ph->Header32.PoolTag;
        type = gGuest.Guest64 ? ph->Header64.PoolType : ph->Header32.PoolType;

        sz = gGuest.Guest64 ? ph->Header64.BlockSize : ph->Header32.BlockSize;
        sz *= WIN_POOL_BLOCK_SIZE;

        if (tag == PoolTag && offset + sz <= PAGE_SIZE && type == NonPagedPoolMustSucceed)
        {
            break;
        }

        offset -= WIN_POOL_HEADER_SIZE;
        ph = NULL;
    }

    if (NULL == ph)
    {
        status = INT_STATUS_NOT_FOUND;
        goto _exit;
    }

    if (offset + sz < originalOffset)
    {
        status = INT_STATUS_INVALID_OBJECT_TYPE;
        goto _exit;
    }
    
    status = IntStructFill(map + offset, sz, Invariants, Count, LogErrors, Endpoint);
    if (!INT_SUCCESS(status))
    {
        if (LogErrors)
        {
            IntDumpBuffer(map, alignedAddr, PAGE_SIZE, 16, 1, TRUE, TRUE);
        }
    }

_exit:

    IntVirtMemUnmap(&map);

    return status;
}


static INTSTATUS
IntWinNetGetTcpEndpoint(
    _In_ QWORD Gva,
    _Inout_ INTRONET_ENDPOINT *Endpoint
    )
{
    INTSTATUS status;

    static BOOLEAN found = FALSE;
    static INT_STRUCT_INVARIANT invs[] =
    {
        {
            .Offset = INT_OFFSET_NOT_INITIALIZED,
            .Getter = IntWinNetGetAddrFam,
        },
        {
            .Offset = INT_OFFSET_NOT_INITIALIZED,
            .Getter = IntWinNetGetAddrInfo,
        },
        {
            .Offset = INT_OFFSET_NOT_INITIALIZED,
            .Getter = IntWinNetGetPortsAndState,
        },
        {
            .Offset = INT_OFFSET_NOT_INITIALIZED,
            .Getter = IntWinNetGetOwner,
        },
    };

    status = IntWinNetFillTcpStruct(Gva, invs, ARRAYSIZE(invs), POOL_TAG_TCPE, found, Endpoint);
    if (!INT_SUCCESS(status))
    {
        WARNING("[WARNING] Failed to fill endpoint from 0x%016llx: 0x%08x\n", Gva, status);
        if (!found)
        {
            for (size_t i = 0; i < ARRAYSIZE(invs); i++)
            {
                invs[i].Offset = INT_OFFSET_NOT_INITIALIZED;
            }
        }
    }
    else
    {
        found = TRUE;
    }

    return status;
}


static INTSTATUS
IntWinNetGetTcpListener(
    _In_ QWORD Gva,
    _Inout_ INTRONET_ENDPOINT *Endpoint
    )
{
    INTSTATUS status;

    static BOOLEAN found = FALSE;
    static INT_STRUCT_INVARIANT invs[] =
    {
        {
            .Offset = INT_OFFSET_NOT_INITIALIZED,
            .Getter = IntWinNetGetOwner,
        },

        {
            .Offset = INT_OFFSET_NOT_INITIALIZED,
            .Getter = IntWinNetGetListenerAddressInfo,
        },
    };

    status = IntWinNetFillTcpStruct(Gva, invs, ARRAYSIZE(invs), POOL_TAG_TCPL, found, Endpoint);
    if (!INT_SUCCESS(status))
    {
        WARNING("[WARNING] Failed to fill listener from 0x%016llx: 0x%08x\n", Gva, status);

        if (!found)
        {
            for (size_t i = 0; i < ARRAYSIZE(invs); i++)
            {
                invs[i].Offset = INT_OFFSET_NOT_INITIALIZED;
            }
        }
    }
    else
    {
        found = TRUE;
    }

    return status;
}


static INTSTATUS
IntWinNetIterateLinkedList(
    _In_ QWORD Gva,
    _In_ PFUNC_IntWinNetCallback Callback,
    _Inout_opt_ void *Context
    )
{

    INTSTATUS status;
    QWORD flink = 0;
    QWORD head = FIX_GUEST_POINTER(gGuest.Guest64, Gva);
    size_t iters = 0;

    status = IntKernVirtMemFetchWordSize(head, &flink);
    if (!INT_SUCCESS(status))
    {
        return status;
    }

    while (flink != head && iters++ < WINNET_LIST_ITERS_CAP)
    {
        QWORD old = flink;
        INTRONET_ENDPOINT net = { 0 };

        status = IntWinNetGetTcpEndpoint(flink, &net);
        if (!INT_SUCCESS(status))
        {
            WARNING("[WARNING] Failed to extract tcp endpoint from 0x%016llx: 0x%08x\n", flink, status);
            return status;
        }

        Callback(&net, Context);

        status = IntKernVirtMemFetchWordSize(old, &flink);
        if (!INT_SUCCESS(status))
        {
            WARNING("[WARNING] IntKernVirtMemFetchWordSize failed for 0x%016llx: 0x%08x\n", old, status);
            return status;
        }

        flink = FIX_GUEST_POINTER(gGuest.Guest64, flink);

        // don't trust the guest, this may be a moment when this endpoint is to
        // be removed from the linked list, so it's list entry will point to itself,
        // causing an infinite loop here.
        if (old == flink)
        {
            ERROR("[ERROR] Entry @ 0x%016llx points to itself\n", old);
            return INT_STATUS_SUCCESS;
        }
    }

    return INT_STATUS_SUCCESS;
}


static INTSTATUS
IntWinNetParseTcpPartition(
    _In_ PFUNC_IntWinNetCallback Callback,
    _Inout_opt_ void *Context
    )
{
#define TCP_DIRECTORY_ENTRY_CNT     0x80
#define TCP_DIRECTORY_ENTRY_SIZE    (2ull * (gGuest.WordSize))
#define TCP_DIRECTORY_SIZE          (TCP_DIRECTORY_ENTRY_CNT * TCP_DIRECTORY_ENTRY_SIZE)

    for (DWORD i = 0; i < gWinNet.Partition.Count; i++)
    {
        QWORD ht, dir, addr;
        DWORD cnt, sz;
        INTSTATUS status;

        union
        {
            RTL_DYNAMIC_HASH_TABLE64 Ht64;
            RTL_DYNAMIC_HASH_TABLE32 Ht32;
        } tbl;

        addr = gWinNet.Partition.Table + (QWORD)i * gWinNet.Partition.Size + gGuest.WordSize;

        ht = 0;
        status = IntKernVirtMemFetchWordSize(addr, &ht);
        if (!INT_SUCCESS(status))
        {
            ERROR("[ERROR] IntKernVirtMemFetchWordSize failed for 0x%016llx: 0x%08x\n",
                  addr, status);
            return status;
        }

        sz = gGuest.Guest64 ? sizeof(tbl.Ht64) : sizeof(tbl.Ht32);
        status = IntKernVirtMemRead(ht, sz, &tbl, NULL);
        if (!INT_SUCCESS(status))
        {
            continue;
        }

        dir = gGuest.Guest64 ? tbl.Ht64.Directory : tbl.Ht32.Directory;
        cnt = gGuest.Guest64 ? tbl.Ht64.NonEmptyBuckets : tbl.Ht32.NonEmptyBuckets;

        // don't iterate a directory with empty buckets.
        if (cnt == 0)
        {
            continue;
        }

        for (size_t j = 0; j < TCP_DIRECTORY_ENTRY_CNT; j++)
        {
            QWORD list = FIX_GUEST_POINTER(gGuest.Guest64, dir + j * TCP_DIRECTORY_ENTRY_SIZE);

            status = IntWinNetIterateLinkedList(list, Callback, Context);
            if (!INT_SUCCESS(status))
            {
                WARNING("[WARNING] IntWinNetIterateLinkedList failed: 0x%08x\n", status);
            }
        }

    }
#undef TCP_DIRECTORY_SIZE
#undef TCP_DIRECTORY_ENTRY_SIZE
#undef TCP_DIRECTORY_ENTRY_CNT

    return INT_STATUS_SUCCESS;
}


static INTSTATUS
IntWinNetIterateSlinkedList(
    _In_ INTRONET_PORT Port,
    _In_ QWORD Gva,
    _In_ PFUNC_IntWinNetCallback Callback,
    _Inout_opt_ void *Context
    )
{
// Pointers inside the InetPortAssignmentArray are not properly aligned. There may be some refcount bits
// or something. This is the mask Windows applies as well.
#define WINNET_CLEAN_PTR_MASK   ((QWORD)0xFFFFFFFFFFFFFFFCull)

    INTSTATUS status = INT_STATUS_SUCCESS;
    QWORD slist = Gva & WINNET_CLEAN_PTR_MASK;
    QWORD slistOld = 0;
    size_t iters = 0;

    while (IS_KERNEL_POINTER_WIN(gGuest.Guest64, slist) && slist != slistOld && iters++ < WINNET_LIST_ITERS_CAP)
    {
        INTRONET_ENDPOINT net = { .LocalPort = Port };

        status = IntWinNetGetTcpListener(slist, &net);
        if (INT_SUCCESS(status))
        {
            // We ignore errors here because we might have "dummy" endpoints active on this port.
            // We might want to look into those because we might not actually need to iterate the
            // TCP Partition if we can get to the "real" endpoints from here.

            Callback(&net, Context);
        }

        slistOld = slist;
        status = IntKernVirtMemFetchWordSize(slistOld, &slist);
        if (!INT_SUCCESS(status))
        {
            return status;
        }

        slist &= WINNET_CLEAN_PTR_MASK;
    }

    return status;

#undef WINNET_CLEAN_PTR_MASK
}


static INTSTATUS
IntWinNetParseTcpBitmap(
    _In_ PFUNC_IntWinNetCallback Callback,
    _Inout_opt_ void *Context
    )
{
    INTSTATUS status;
    DWORD sz = 0x10000;
    BITMASK *bts;
    size_t pasz, offListener, offPa;

    offListener = gGuest.WordSize;

    if (gGuest.OSVersion >= 19041)
    {
        pasz = gGuest.Guest64 ? 4ull * sizeof(QWORD) : 6ull * sizeof(DWORD);
        offPa = gGuest.Guest64 ? 3 * sizeof(QWORD) : 4 * sizeof(DWORD);
        offListener = 2 * sizeof(QWORD);
    }
    else if (gGuest.OSVersion >= 9600)
    {
        pasz = 3ull * gGuest.WordSize;
        offPa = gGuest.Guest64 ? 3 * sizeof(QWORD) : 4 * sizeof(DWORD);
    }
    else
    {
        pasz = 2ull * gGuest.WordSize;
        offPa = gGuest.Guest64 ? 4 * sizeof(QWORD) : 5 * sizeof(DWORD);
    }

    bts = BitMaskAlloc(sz);
    if (NULL == bts)
    {
        ERROR("[ERROR] BitMaskAlloc failed\n");
        return INT_STATUS_INSUFFICIENT_RESOURCES;
    }


    status = IntKernVirtMemRead(gWinNet.Bitmap.Buffer, sz / 8, bts->Bits, NULL);
    if (!INT_SUCCESS(status))
    {
        ERROR("[ERROR] IntKernVirtMemRead failed to read 0x%x bytes from 0x%016llx: 0x%08x\n",
              sz / 8, gWinNet.Bitmap.Buffer, status);
        goto _exit;
    }

    for (DWORD i = 1; i < sz; i++)
    {
#define TCP_PORT_ASSIGNMENT_ARRAY_INDEX(i)      (((i) >> 8) & 0xFF)
#define TCP_PORT_ASSIGNMENT_INDEX(i)            ((i) & 0xFF)

        QWORD addr = 0;
        QWORD arr = 0;
        QWORD pa = 0;
        QWORD listener = 0;

        if (!BitMaskTest(bts, i))
        {
            continue;
        }

        addr = gWinNet.Bitmap.PortAssignment + (QWORD)gGuest.WordSize * TCP_PORT_ASSIGNMENT_ARRAY_INDEX(i);
        status = IntKernVirtMemFetchWordSize(addr, &arr);
        if (!INT_SUCCESS(status))
        {
            continue;
        }

        arr += offPa;
        status = IntKernVirtMemFetchWordSize(arr, &pa);
        if (!INT_SUCCESS(status))
        {
            continue;
        }

        pa += pasz * TCP_PORT_ASSIGNMENT_INDEX(i) + offListener;
        status = IntKernVirtMemFetchWordSize(pa, &listener);
        if (!INT_SUCCESS(status))
        {
            continue;
        }

        status = IntWinNetIterateSlinkedList((INTRONET_PORT)i, listener, Callback, Context);
        if (!INT_SUCCESS(status))
        {
            WARNING("[WARNING] IntWinNetIterateSlinkedList failed: 0x%08x\n", status);
        }

#undef TCP_PORT_ASSIGNMENT_INDEX
#undef TCP_PORT_ASSIGNMENT_ARRAY_INDEX
    }

_exit:
    BitMaskFree(&bts);

    return INT_STATUS_SUCCESS;
}


static INTSTATUS
IntWinNetCheckPartition(
    _In_reads_bytes_(Size) const BYTE *Buffer,
    _In_ size_t Size
    )
{
    QWORD page;
    size_t sz;
    INTSTATUS status;

    // Describe the fist 3 elements of a tcpip!_PARTITION undocumented structure.
    // Each of those should pe pointers to some nt!_RTL_DYNAMIC_HASH_TABLE that
    // reside in the same page, with the THcT pool tag.
    const union _PARTITION
    {
        DWORD Part32[3];
        QWORD Part64[3];
    } *part = (const union _PARTITION *)Buffer;

    sz = gGuest.Guest64 ? sizeof(part->Part64) : sizeof(part->Part32);

    if (sz > Size)
    {
        return INT_STATUS_INVALID_DATA_SIZE;
    }

    page = (gGuest.Guest64 ? part->Part64[0] : part->Part32[0]) & PAGE_MASK;
    if (!IS_KERNEL_POINTER_WIN(gGuest.Guest64, page))
    {
        return INT_STATUS_INVALID_DATA_TYPE;
    }

    for (size_t i = 0; i < ARRAYSIZE(part->Part64); i++)
    {
        QWORD p = gGuest.Guest64 ? part->Part64[i] : part->Part32[i];
        DWORD ptag;

        if (i == 0)
        {
            if ((p - WIN_POOL_HEADER_SIZE) < page)
            {
                return INT_STATUS_INVALID_DATA_TYPE;
            }

            status = IntKernVirtMemFetchDword(p - WIN_POOL_HEADER_SIZE + 4, &ptag);
            if (!INT_SUCCESS(status))
            {
                return status;
            }

            if (ptag != POOL_TAG_TCHT)
            {
                return INT_STATUS_INVALID_OBJECT_TYPE;
            }
        }
        else
        {
            if ((p & PAGE_MASK) != page)
            {
                return INT_STATUS_INVALID_DATA_TYPE;
            }
        }

    }

    return INT_STATUS_SUCCESS;
}


static INTSTATUS
IntWinNetFindTcpPartition(
    _In_ QWORD PartitionAddress,
    _In_ QWORD PartitionPointer
    )
{
    BYTE *map;
    QWORD addr;
    QWORD cnt;
    DWORD sz;
    DWORD off;
    INTSTATUS status;

    if (gWinNet.Partition.Found)
    {
        return INT_STATUS_ALREADY_INITIALIZED;
    }

    if (!IS_KERNEL_POINTER_WIN(gGuest.Guest64, PartitionAddress))
    {
        return INT_STATUS_INVALID_DATA_TYPE;
    }

    off = PartitionAddress & PAGE_OFFSET;
    if (ROUND_DOWN(off, gGuest.WordSize) != off)
    {
        return INT_STATUS_ALIGNMENT_INCONSISTENCY;
    }

    status = IntVirtMemMap(PartitionAddress & PAGE_MASK, PAGE_SIZE, gGuest.Mm.SystemCr3, 0, &map);
    if (!INT_SUCCESS(status))
    {
        return status;
    }

    // Check for a valid tcpip!_PARTITION.
    status = IntWinNetCheckPartition(map + off, PAGE_SIZE - off);
    if (!INT_SUCCESS(status))
    {
        goto _exit;
    }

    // Read the tcpip!PartitionCount value.
    addr = PartitionPointer;

    if (gGuest.OSVersion >= 19041)
    {
        sz = gGuest.WordSize;
        addr -= gGuest.WordSize;
    }
    else if (gGuest.OSVersion >= 9600)
    {
        sz = sizeof(DWORD);
        addr -= sizeof(DWORD);
    }
    else if (gGuest.OSVersion >= 9200)
    {
        sz = gGuest.WordSize;
        addr -= gGuest.WordSize;
    }
    else
    {
        sz = 2;
        addr += gGuest.WordSize + 2ull;
    }

    cnt = 0;
    status = IntKernVirtMemRead(addr, sz, &cnt, NULL);
    if (!INT_SUCCESS(status))
    {
        goto _exit;
    }

    if (cnt > TCPIP_MAX_PARTITION_CNT)
    {
        goto _exit;
    }

    if (cnt > 1)
    {
        // Search for the next partition to determine the size.
        status = INT_STATUS_NOT_FOUND;
        for (DWORD cur = off + 8 * gGuest.WordSize; cur < PAGE_SIZE; cur += gGuest.WordSize)
        {
            status = IntWinNetCheckPartition(map + cur, PAGE_SIZE - cur);
            if (INT_SUCCESS(status))
            {
                sz = cur - off;
                break;
            }
        }

        if (!INT_SUCCESS(status))
        {
            goto _exit;
        }
    }
    else
    {
        // We don't realy care for it's size if there's only one of them but set it just in case.
        sz = PAGE_SIZE - off;
    }

    IntDumpGvaEx(PartitionPointer - 8, 0x20, gGuest.Mm.SystemCr3, 16, 1, FALSE, TRUE);

    gWinNet.Partition.Table = PartitionAddress;
    gWinNet.Partition.Size = sz;
    gWinNet.Partition.Count = (DWORD)cnt;

    TRACE("[WINNET] Found tcpip!ParitionTable @ 0x%016llx pointing to"
          " 0x%016llx with %u elements of size 0x%x from 0x%016llx\n",
          PartitionAddress, gWinNet.Partition.Table, gWinNet.Partition.Count,
          gWinNet.Partition.Size, PartitionPointer);

    gWinNet.Partition.Found = TRUE;
    
    status = INT_STATUS_SUCCESS;

_exit:
    IntVirtMemUnmap(&map);

    return status;
}


static INTSTATUS
IntWinNetSearchForAlloc(
    _In_ QWORD Gva,
    _In_ DWORD Tag,
    _Out_ QWORD *Alloc
    )
{
    BYTE *map;
    QWORD aligned;
    DWORD off;
    INTSTATUS status;

    aligned = Gva & PAGE_MASK;
    off = ROUND_UP(Gva & PAGE_OFFSET, gGuest.WordSize);

    status = IntVirtMemMap(aligned, PAGE_SIZE, gGuest.Mm.SystemCr3, 0, &map);
    if (!INT_SUCCESS(status))
    {
        return status;
    }

    while (off < PAGE_SIZE)
    {
        QWORD addr = gGuest.Guest64 ? *(QWORD *)((size_t)map + off) :
                                      *(DWORD *)((size_t)map + off);
        DWORD tag;

        status = IntKernVirtMemFetchDword(addr - WIN_POOL_HEADER_SIZE + 4, &tag);
        if (INT_SUCCESS(status) && tag == Tag)
        {
            *Alloc = addr;
            goto _exit;
        }

        off += gGuest.WordSize;
    }

    status = INT_STATUS_NOT_FOUND;

_exit:
    IntVirtMemUnmap(&map);

    return status;
}


static INTSTATUS
IntWinNetGetTcpPortPoolFromCompartment(
    _In_ QWORD Gva,
    _Out_ QWORD *PortPool
    )
{
    QWORD inetCmp, tcpCmp, pool;
    DWORD tag;
    INTSTATUS status;

    if (ROUND_DOWN(Gva, WIN_POOL_HEADER_SIZE) != Gva)
    {
        return INT_STATUS_ALIGNMENT_INCONSISTENCY;
    }

    status = IntKernVirtMemFetchDword(Gva - WIN_POOL_HEADER_SIZE + 4, &tag);
    if (!INT_SUCCESS(status) || POOL_TAG_INCS != tag)
    {
        return INT_STATUS_INVALID_OBJECT_TYPE;
    }

    status = IntWinNetSearchForAlloc(Gva, POOL_TAG_INCO, &inetCmp);
    if (!INT_SUCCESS(status))
    {
        return status;
    }

    status = IntWinNetSearchForAlloc(inetCmp, POOL_TAG_TCCO, &tcpCmp);
    if (!INT_SUCCESS(status))
    {
        return status;
    }

    pool = 0;
    status = IntKernVirtMemFetchWordSize(tcpCmp, &pool);
    if (!INT_SUCCESS(status))
    {
        return status;
    }

    if ((pool & PAGE_OFFSET) != 0)
    {
        return INT_STATUS_ALIGNMENT_INCONSISTENCY;
    }

    *PortPool = pool;

    return INT_STATUS_SUCCESS;
}



static INTSTATUS
IntWinNetGetTcpPortPool(
    _In_ QWORD Gva,
    _Out_ QWORD *PortPool
    )
{
    QWORD addr;
    INTSTATUS status;

    union
    {
        DWORD Ptr32[2];
        QWORD Ptr64[2];
    } ptrs;

    if ((Gva & PAGE_OFFSET) != 0)
    {
        return INT_STATUS_ALIGNMENT_INCONSISTENCY;
    }

    status = IntKernVirtMemRead(Gva, 2 * gGuest.WordSize, &ptrs, NULL);
    if (!INT_SUCCESS(status))
    {
        return status;
    }

    addr = gGuest.Guest64 ? ptrs.Ptr64[0] : ptrs.Ptr32[0];
    if (IS_KERNEL_POINTER_WIN(gGuest.Guest64, addr) && 
        (addr & PAGE_OFFSET) == 0)
    {
        *PortPool = Gva;
        return INT_STATUS_SUCCESS;
    }

    addr = gGuest.Guest64 ? ptrs.Ptr64[1] : ptrs.Ptr32[1];
    if (IS_KERNEL_POINTER_WIN(gGuest.Guest64, addr) &&
        (addr & PAGE_OFFSET) == 0)
    {
        *PortPool = addr;
        return INT_STATUS_SUCCESS;
    }

    return INT_STATUS_INVALID_OBJECT_TYPE;
}


static INTSTATUS
IntWinNetFindTcpBitmap(
    _In_ QWORD Gva,
    _In_ QWORD Addr
    )
{
    void *map;
    QWORD pool, sz, buf, pa;
    size_t i;
    DWORD tag;
    INTSTATUS status;

    if (gWinNet.Bitmap.Found)
    {
        return INT_STATUS_ALREADY_INITIALIZED;
    }

    if (gGuest.OSVersion > 10586)
    {
        status = IntWinNetGetTcpPortPoolFromCompartment(Gva, &pool);
    }
    else
    {
        status = IntWinNetGetTcpPortPool(Gva, &pool);
    }
    if (!INT_SUCCESS(status))
    {
        return status;
    }

    status = IntVirtMemMap(pool, PAGE_SIZE, gGuest.Mm.SystemCr3, 0, &map);
    if (!INT_SUCCESS(status))
    {
        return status;
    }

    buf = pa = 0;
    status = INT_STATUS_NOT_FOUND;
    for (i = 0; i < PAGE_SIZE - 2ull * gGuest.WordSize; i += gGuest.WordSize)
    {
        size_t p = (size_t)map + i;
        sz = gGuest.Guest64 ? ((QWORD *)p)[0] : ((DWORD *)p)[0];
        buf = gGuest.Guest64 ? ((QWORD *)p)[1] : ((DWORD *)p)[1];
        pa = gGuest.Guest64 ? ((QWORD *)p)[2] : ((DWORD *)p)[2];

        sz &= 0xFFFFFFFF;
        
        if (0x10000 == sz && IS_KERNEL_POINTER_WIN(gGuest.Guest64, buf) &&
            ((buf & PAGE_MASK) == (pool & PAGE_MASK)))
        {
            status = INT_STATUS_SUCCESS;
            break;
        }
    }

    if (!INT_SUCCESS(status))
    {
        goto _exit;
    }

    status = IntKernVirtMemFetchDword(pa - WIN_POOL_HEADER_SIZE + 4, &tag);
    if (!INT_SUCCESS(status) || POOL_TAG_INPA != tag)
    {
        status = INT_STATUS_INVALID_OBJECT_TYPE;
        goto _exit;
    }

    gWinNet.Bitmap.PortAssignment = pool + i + 2ull * gGuest.WordSize;
    gWinNet.Bitmap.Buffer = buf;

    TRACE("[WINNET] Found tcpip!TcpPortPool @ 0x%016llx, BitmapBuffer @ 0x%016llx, "
          "and port assignment array @ 0x%016llx from 0x%016llx:0x%016llx\n", pool,
          gWinNet.Bitmap.Buffer, gWinNet.Bitmap.PortAssignment, Gva, Addr);

    gWinNet.Bitmap.Found = TRUE;

    status = INT_STATUS_SUCCESS;

_exit:
    IntVirtMemUnmap(&map);

    return status;
}


static INTSTATUS
IntWinNetFindTcpObjects(
    void
    )
{
    IMAGE_SECTION_HEADER sec;
    PKERNEL_DRIVER drv;
    DWORD objs;
    INTSTATUS status;

    if (gWinNet.Bitmap.Found && gWinNet.Partition.Found)
    {
        return INT_STATUS_ALREADY_INITIALIZED_HINT;
    }

    drv = IntDriverFindByName(u"tcpip.sys");
    if (NULL == drv)
    {
        ERROR("[ERROR] Failed to find `tcpip.sys`\n");
        return INT_STATUS_NOT_FOUND;
    }

    TRACE("[WINNET] tcpip.sys @ 0x%016llx\n", drv->BaseVa);

    status = IntPeGetSectionHeaderByName(drv->BaseVa, NULL, ".data", gGuest.Mm.SystemCr3, &sec);
    if (!INT_SUCCESS(status))
    {
        ERROR("[ERROR] Failed to find `.data` section in `tcpip.sys`: 0x%08x\n", status);
        return status;
    }

    objs = 0;
    for (size_t page = 0; page < ROUND_UP((size_t)sec.Misc.VirtualSize, PAGE_SIZE); page += PAGE_SIZE)
    {
        QWORD gva = drv->BaseVa + sec.VirtualAddress + page;
        void *map;

        status = IntVirtMemMap(gva, PAGE_SIZE, gGuest.Mm.SystemCr3, 0, &map);
        if (!INT_SUCCESS(status))
        {
            ERROR("[ERROR] IntVirtMemMap failed for 0x%016llx: 0x%08x\n", gva, status);
            return status;
        }

        for (size_t i = 0; objs < 2 && i < PAGE_SIZE / gGuest.WordSize; i++)
        {
            QWORD ptr = gGuest.Guest64 ? ((QWORD *)map)[i] : ((DWORD *)map)[i];

            status = IntWinNetFindTcpPartition(ptr, gva + i * gGuest.WordSize);
            if (INT_SUCCESS(status))
            {
                objs++;
                continue;
            }

            status = IntWinNetFindTcpBitmap(ptr, gva + i * gGuest.WordSize);
            if (INT_SUCCESS(status))
            {
                objs++;
                continue;
            }
        }

        IntVirtMemUnmap(&map);

        if (objs == 2)
        {
            status = INT_STATUS_SUCCESS;
            break;
        }
    }

    return status;
}


static INTSTATUS
IntWinNetIterateConnections(
    _In_ PFUNC_IntWinNetCallback Callback,
    _Inout_opt_ void *Context
    )
{
    INTSTATUS status;

    status = IntWinNetFindTcpObjects();
    if (!INT_SUCCESS(status))
    {
        ERROR("[ERROR] IntWinNetFindTcpObjects failed ( 0x%016llx, 0x%016llx): 0x%08x\n", 
              gWinNet.Partition.Table, gWinNet.Bitmap.Buffer, status);
        return status;
    }

    status = IntWinNetParseTcpPartition(Callback, Context);
    if (!INT_SUCCESS(status))
    {
        WARNING("[WARNING] IntWinNetParseTcpPartition failed: 0x%08x\n", status);
    }

    status = IntWinNetParseTcpBitmap(Callback, Context);
    if (!INT_SUCCESS(status))
    {
        WARNING("[WARNING] IntWinNetParseTcpBitmap failed: 0x%08x\n", status);
    }

    return status;
}


_Function_class_(PFUNC_IntWinNetCallback) static INTSTATUS
IntWinNetSendConnectionEvent(
    _In_ const INTRONET_ENDPOINT *Endpoint,
    _Inout_opt_ void *Context
    )
{
    INTSTATUS status;
    EVENT_CONNECTION_EVENT *evt = &gAlert.Connection;
    const WIN_PROCESS_OBJECT *proc = (WIN_PROCESS_OBJECT *)Context;

    if (proc != Endpoint->OwnerProcess)
    {
        return INT_STATUS_NOT_NEEDED_HINT;
    }

    IntAlertFillConnection(Endpoint, evt);

    status = IntNotifyIntroEvent(introEventConnectionEvent, evt, sizeof(*evt));
    if (!INT_SUCCESS(status))
    {
        WARNING("[WARNING] IntNotifyIntroEvent failed: 0x%08x\n", status);
    }

    return status;
}


INTSTATUS
IntWinNetSendProcessConnections(
    _In_ WIN_PROCESS_OBJECT *Process
    )
{
    if (!(gGuest.CoreOptions.Current & INTRO_OPT_EVENT_CONNECTIONS))
    {
        return INT_STATUS_NOT_NEEDED_HINT;
    }

    return IntWinNetIterateConnections(IntWinNetSendConnectionEvent, Process);
}


_Function_class_(PFUNC_IntWinNetCallback) static INTSTATUS
IntWinNetDumpConnection(
    _In_ const INTRONET_ENDPOINT *Endpoint,
    _Inout_opt_ void *Context
    )
{
    char local[INTRONET_MIN_BUFFER_SIZE] = { 0 };
    char remote[INTRONET_MIN_BUFFER_SIZE] = { 0 };

    UNREFERENCED_PARAMETER(Context);

    IntNetAddrToStr(Endpoint->AddressFamily, &Endpoint->LocalAddress, local);
    IntNetAddrToStr(Endpoint->AddressFamily, &Endpoint->RemoteAddress, remote);

    LOG("[WINNET] Endpoint @ 0x%016llx Local %s:%d Remote %s:%d State %s Owner 0x%016llx (%s:%u)\n",
        Endpoint->Endpoint, local, Endpoint->LocalPort, remote, Endpoint->RemotePort,
        IntNetStateToString(Endpoint->State), Endpoint->Endpoint,
        Endpoint->OwnerProcess->Name, Endpoint->OwnerProcess->Pid);

    return INT_STATUS_SUCCESS;
}


//
// IntWinNetDumpConnections
//
INTSTATUS
IntWinNetDumpConnections(
    void
    )
{
    return IntWinNetIterateConnections(IntWinNetDumpConnection, NULL);
}