scsir 0.3.0

A simple library for issuing SCSI commands
Documentation 
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

#![allow(dead_code)]

use std::mem::size_of_val;

use modular_bitfield_msb::prelude::*;

use crate::command::get_array;

#[bitfield]
#[derive(Clone, Copy, Debug)]
pub struct ShortHeader {
    pub mode_data_length: B8,
    pub medium_type: B8,
    pub write_protect: B1,
    reserved_0: B2,
    pub dpo_and_fua_support: B1,
    reserved_1: B4,
    pub block_descriptor_length: B8,
}

#[bitfield]
#[derive(Clone, Copy, Debug)]
pub struct LongHeader {
    pub mode_data_length: B16,
    pub medium_type: B8,
    pub write_protect: B1,
    reserved_0: B2,
    pub dpo_and_fua_support: B1,
    reserved_1: B4,
    reserved_2: B7,
    pub long_lba: B1,
    reserved_3: B8,
    pub block_descriptor_length: B16,
}

#[derive(Clone, Copy, Debug)]
pub enum HeaderType {
    Short,
    Long,
}

#[derive(Clone, Copy, Debug)]
pub enum HeaderStorage {
    Short(ShortHeader),
    Long(LongHeader),
}

impl HeaderStorage {
    pub fn from_bytes(header_type: HeaderType, bytes: &[u8]) -> (Self, &[u8]) {
        match header_type {
            HeaderType::Short => {
                let (array, bytes) = get_array(bytes);
                (HeaderStorage::Short(ShortHeader::from_bytes(array)), bytes)
            }
            HeaderType::Long => {
                let (array, bytes) = get_array(bytes);
                (HeaderStorage::Long(LongHeader::from_bytes(array)), bytes)
            }
        }
    }

    pub fn required_allocation_length(&self) -> u16 {
        match self {
            HeaderStorage::Short(h) => (h.mode_data_length() as u16)
                .saturating_add(size_of_val(&h.mode_data_length()) as u16),
            HeaderStorage::Long(h) => h
                .mode_data_length()
                .saturating_add(size_of_val(&h.mode_data_length()) as u16),
        }
    }

    pub fn mode_data_length(&self) -> u16 {
        match self {
            HeaderStorage::Short(h) => h.mode_data_length() as u16,
            HeaderStorage::Long(h) => h.mode_data_length(),
        }
    }

    pub fn medium_type(&self) -> u8 {
        match self {
            HeaderStorage::Short(h) => h.medium_type(),
            HeaderStorage::Long(h) => h.medium_type(),
        }
    }

    pub fn write_protect(&self) -> bool {
        match self {
            HeaderStorage::Short(h) => h.write_protect() != 0,
            HeaderStorage::Long(h) => h.write_protect() != 0,
        }
    }

    pub fn dpo_and_fua_support(&self) -> bool {
        match self {
            HeaderStorage::Short(h) => h.dpo_and_fua_support() != 0,
            HeaderStorage::Long(h) => h.dpo_and_fua_support() != 0,
        }
    }

    pub fn long_lba(&self) -> bool {
        match self {
            HeaderStorage::Short(_) => false,
            HeaderStorage::Long(h) => h.long_lba() != 0,
        }
    }

    pub fn block_descriptor_length(&self) -> u16 {
        match self {
            HeaderStorage::Short(h) => h.block_descriptor_length() as u16,
            HeaderStorage::Long(h) => h.block_descriptor_length(),
        }
    }

    pub fn to_bytes(&self) -> Vec<u8> {
        match self {
            HeaderStorage::Short(h) => h.bytes.to_vec(),
            HeaderStorage::Long(h) => h.bytes.to_vec(),
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use std::mem::size_of;

    const SHORT_HEADER_LENGTH: usize = 4;
    const LONG_HEADER_LENGTH: usize = 8;

    #[test]
    fn layout_test() {
        assert_eq!(
            size_of::<ShortHeader>(),
            SHORT_HEADER_LENGTH,
            concat!("Size of: ", stringify!(ShortHeader))
        );

        assert_eq!(
            size_of::<LongHeader>(),
            LONG_HEADER_LENGTH,
            concat!("Size of: ", stringify!(LongHeader))
        );
    }
}