aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/src/nt_path_converter/device.c
blob: 90fcc9844d73199cde17730ba45349c01ebaa91b (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
/**
 * \file
 * \author Egor Tensin <Egor.Tensin@gmail.com>
 * \copyright This file is licensed under the terms of the MIT License.
 *            See LICENSE.txt for details.
 */

#include "control_codes.h"
#include "device.h"
#include "nt2dos.h"

#include <ntddk.h>

static NTSTATUS device_open(DEVICE_OBJECT *device_object, IRP *irp)
{
    NTSTATUS status = STATUS_SUCCESS;

    irp->IoStatus.Status = status;
    irp->IoStatus.Information = 0;
    IoCompleteRequest(irp, IO_NO_INCREMENT);
    return status;
}

typedef NTSTATUS (*ioctl_handler)(void *, unsigned long,
                                  void *, unsigned long,
                                  ULONG_PTR *);

static NTSTATUS handle_convert_nt_path(void *in_buf,
                                       unsigned long in_buf_size,
                                       void *out_buf,
                                       unsigned long out_buf_size,
                                       ULONG_PTR *nbwritten)
{
    UNICODE_STRING uUnresolved, uResolved;
    NTSTATUS status = STATUS_SUCCESS;

    RtlInitUnicodeString(&uUnresolved, (WCHAR *) in_buf);
    status = nt2dos(&uResolved, &uUnresolved);

    if (!NT_SUCCESS(status))
        return status;

    *nbwritten = uResolved.Length;

    if (out_buf_size < uResolved.Length)
    {
        status = STATUS_BUFFER_OVERFLOW;
        goto FREE_RESOLVED;
    }

    RtlCopyMemory(out_buf, uResolved.Buffer, uResolved.Length);

FREE_RESOLVED:
    ExFreePool(uResolved.Buffer);

    return status;
}

static NTSTATUS device_ioctl(DEVICE_OBJECT *device_object, IRP *irp)
{
    IO_STACK_LOCATION *io_stack_loc;
    void* in_buf, *out_buf;
    unsigned long in_buf_size, out_buf_size;
    ioctl_handler handler;
    NTSTATUS status = STATUS_UNSUCCESSFUL;

    irp->IoStatus.Status = status;
    irp->IoStatus.Information = 0;
    io_stack_loc = IoGetCurrentIrpStackLocation(irp);

    in_buf = out_buf = irp->AssociatedIrp.SystemBuffer;
    in_buf_size = io_stack_loc->Parameters.DeviceIoControl.InputBufferLength;
    out_buf_size = io_stack_loc->Parameters.DeviceIoControl.OutputBufferLength;

    switch (io_stack_loc->Parameters.DeviceIoControl.IoControlCode)
    {
        case CONVERT_NT_PATH:
            handler = handle_convert_nt_path;
            break;
        default:
            status = irp->IoStatus.Status = STATUS_NOT_SUPPORTED;
            goto complete_request;
    }

    status = irp->IoStatus.Status = handler(in_buf, in_buf_size,
                                            out_buf, out_buf_size,
                                            &irp->IoStatus.Information);

complete_request:
    IoCompleteRequest(irp, IO_NO_INCREMENT);

    return status;
}

typedef struct
{
    const wchar_t *path;
    const wchar_t *symlink;
} device_info;

typedef struct
{
    DEVICE_OBJECT *object;
    UNICODE_STRING path;
    UNICODE_STRING symlink;
} device;

#define NUMOF_DEVICES 1

static device_info devices_info[NUMOF_DEVICES] =
{
    {
        L"\\Device\\nt_path_converter",
        L"\\DosDevices\\nt_path_converter",
    },
};

static device devices[NUMOF_DEVICES];

static void destroy_device(int i)
{
    IoDeleteSymbolicLink(&devices[i].symlink);
    IoDeleteDevice(devices[i].object);
}

void destroy_devices()
{
    int i;
    for (i = 0; i < NUMOF_DEVICES; ++i)
        destroy_device(i);
}

static NTSTATUS set_up_device(DRIVER_OBJECT *driver_object, int i)
{
    NTSTATUS status = STATUS_SUCCESS;

    RtlInitUnicodeString(&devices[i].path, devices_info[i].path);
    RtlInitUnicodeString(&devices[i].symlink, devices_info[i].symlink);

    status = IoCreateDevice(driver_object,
                            0,
                            &devices[i].path,
                            FILE_DEVICE_UNKNOWN,
                            FILE_DEVICE_SECURE_OPEN,
                            FALSE,
                            &devices[i].object);

    if (!NT_SUCCESS(status))
        return status;

    devices[i].object->Flags |= DO_BUFFERED_IO;
    devices[i].object->Flags &= ~DO_DEVICE_INITIALIZING;

    if (!NT_SUCCESS(status = IoCreateSymbolicLink(&devices[i].symlink,
                                                  &devices[i].path)))
        goto delete_device;

    return status;

delete_device:
    IoDeleteDevice(devices[i].object);

    return status;
}

NTSTATUS set_up_devices(DRIVER_OBJECT *driver_object)
{
    int i, j;
    NTSTATUS status = STATUS_SUCCESS;

    for (i = 0; i < NUMOF_DEVICES; ++i)
        if (!NT_SUCCESS(status = set_up_device(driver_object, i)))
            goto destroy_devices;

    driver_object->MajorFunction[IRP_MJ_CREATE] = device_open;
    driver_object->MajorFunction[IRP_MJ_DEVICE_CONTROL] = device_ioctl;

    return status;

destroy_devices:
    for (j = 0; j < i; ++j)
        destroy_device(j);

    return status;
}