aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/um/libservice/src/device.cpp
blob: 5643106005d86b7babc5de5a33f96c5191816bdd (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
// Copyright (c) 2015 Egor Tensin <Egor.Tensin@gmail.com>
// This file is part of the "Windows 7 drivers" project.
// For details, see https://github.com/egor-tensin/windows7-drivers.
// Distributed under the MIT License.

#include "libservice/all.hpp"

#include <Windows.h>

#include <cstddef>

#include <limits>
#include <stdexcept>
#include <string>
#include <system_error>
#include <utility>

namespace libservice
{
    namespace
    {
        Handle open_device(const std::string& path)
        {
            const auto raw = CreateFileA(
                path.c_str(),
                GENERIC_READ | GENERIC_WRITE,
                0,
                NULL,
                OPEN_EXISTING,
                FILE_ATTRIBUTE_NORMAL,
                NULL);

            if (INVALID_HANDLE_VALUE == raw)
            {
                const auto ec = GetLastError();
                throw std::system_error(
                    ec, WindowsErrorCategory::get(), LIBSERVICE_ERROR_PREFIX);
            }

            return Handle(raw);
        }
    }

    Device Device::open(const std::string& path)
    {
        return Device(open_device(path));
    }

    std::size_t Device::get_required_output_size(
        Code code,
        const void* in_buf,
        std::size_t in_buf_size) const
    {
        DWORD nbreq;

        if (in_buf_size > std::numeric_limits<DWORD>::max())
            throw std::range_error("input buffer size is too large");

        std::size_t nbwritten = DeviceIoControl(
            handle,
            code,
            const_cast<void*>(in_buf),
            static_cast<DWORD>(in_buf_size),
            NULL,
            0,
            &nbreq,
            NULL);

        if (0 == nbwritten)
        {
            const auto ec = GetLastError();

            switch (ec)
            {
                case ERROR_MORE_DATA:
                    return nbreq;

                default:
                    throw std::system_error(
                        ec, WindowsErrorCategory::get(), LIBSERVICE_ERROR_PREFIX);
            }
        }

        return nbwritten;
    }

    std::size_t Device::send_control_code(
        Code code,
        const void* in_buf,
        std::size_t in_buf_size,
        void* out_buf,
        std::size_t out_buf_size) const
    {
        DWORD nbreq;

        if (in_buf_size > std::numeric_limits<DWORD>::max())
            throw std::range_error("input buffer size is too large");
        if (out_buf_size > std::numeric_limits<DWORD>::max())
            throw std::range_error("output buffer size is too large");

        std::size_t nbwritten = DeviceIoControl(
            handle,
            code,
            const_cast<void*>(in_buf),
            static_cast<DWORD>(in_buf_size),
            out_buf,
            static_cast<DWORD>(out_buf_size),
            &nbreq,
            NULL);

        if (0 == nbwritten)
        {
            const auto ec = GetLastError();
            throw std::system_error(
                ec, WindowsErrorCategory::get(), LIBSERVICE_ERROR_PREFIX);
        }

        return nbwritten;
    }

    void swap(Device& a, Device& b) LIBSERVICE_NOEXCEPT
    {
        a.swap(b);
    }
}

namespace std
{
    template <>
    void swap<libservice::Device>(
        libservice::Device& a,
        libservice::Device& b)
    {
        a.swap(b);
    }
}