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

use bitflags::bitflags;
use core::mem::MaybeUninit;

use crate::pid::Pid;
use crate::{backend, io};

/// `__user_cap_data_struct`
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub struct CapabilitySets {
    /// `__user_cap_data_struct.effective`
    pub effective: CapabilityFlags,
    /// `__user_cap_data_struct.permitted`
    pub permitted: CapabilityFlags,
    /// `__user_cap_data_struct.inheritable`
    pub inheritable: CapabilityFlags,
}

bitflags! {
    /// `CAP_*` constants.
    #[repr(transparent)]
    #[derive(Copy, Clone, Eq, PartialEq, Hash, Debug)]
    pub struct CapabilityFlags: u64 {
        /// `CAP_CHOWN`
        const CHOWN = 1 << linux_raw_sys::general::CAP_CHOWN;
        /// `CAP_DAC_OVERRIDE`
        const DAC_OVERRIDE = 1 << linux_raw_sys::general::CAP_DAC_OVERRIDE;
        /// `CAP_DAC_READ_SEARCH`
        const DAC_READ_SEARCH = 1 << linux_raw_sys::general::CAP_DAC_READ_SEARCH;
        /// `CAP_FOWNER`
        const FOWNER = 1 << linux_raw_sys::general::CAP_FOWNER;
        /// `CAP_FSETID`
        const FSETID = 1 << linux_raw_sys::general::CAP_FSETID;
        /// `CAP_KILL`
        const KILL = 1 << linux_raw_sys::general::CAP_KILL;
        /// `CAP_SETGID`
        const SETGID = 1 << linux_raw_sys::general::CAP_SETGID;
        /// `CAP_SETUID`
        const SETUID = 1 << linux_raw_sys::general::CAP_SETUID;
        /// `CAP_SETPCAP`
        const SETPCAP = 1 << linux_raw_sys::general::CAP_SETPCAP;
        /// `CAP_LINUX_IMMUTABLE`
        const LINUX_IMMUTABLE = 1 << linux_raw_sys::general::CAP_LINUX_IMMUTABLE;
        /// `CAP_NET_BIND_SERVICE`
        const NET_BIND_SERVICE = 1 << linux_raw_sys::general::CAP_NET_BIND_SERVICE;
        /// `CAP_NET_BROADCAST`
        const NET_BROADCAST = 1 << linux_raw_sys::general::CAP_NET_BROADCAST;
        /// `CAP_NET_ADMIN`
        const NET_ADMIN = 1 << linux_raw_sys::general::CAP_NET_ADMIN;
        /// `CAP_NET_RAW`
        const NET_RAW = 1 << linux_raw_sys::general::CAP_NET_RAW;
        /// `CAP_IPC_LOCK`
        const IPC_LOCK = 1 << linux_raw_sys::general::CAP_IPC_LOCK;
        /// `CAP_IPC_OWNER`
        const IPC_OWNER = 1 << linux_raw_sys::general::CAP_IPC_OWNER;
        /// `CAP_SYS_MODULE`
        const SYS_MODULE = 1 << linux_raw_sys::general::CAP_SYS_MODULE;
        /// `CAP_SYS_RAWIO`
        const SYS_RAWIO = 1 << linux_raw_sys::general::CAP_SYS_RAWIO;
        /// `CAP_SYS_CHROOT`
        const SYS_CHROOT = 1 << linux_raw_sys::general::CAP_SYS_CHROOT;
        /// `CAP_SYS_PTRACE`
        const SYS_PTRACE = 1 << linux_raw_sys::general::CAP_SYS_PTRACE;
        /// `CAP_SYS_PACCT`
        const SYS_PACCT = 1 << linux_raw_sys::general::CAP_SYS_PACCT;
        /// `CAP_SYS_ADMIN`
        const SYS_ADMIN = 1 << linux_raw_sys::general::CAP_SYS_ADMIN;
        /// `CAP_SYS_BOOT`
        const SYS_BOOT = 1 << linux_raw_sys::general::CAP_SYS_BOOT;
        /// `CAP_SYS_NICE`
        const SYS_NICE = 1 << linux_raw_sys::general::CAP_SYS_NICE;
        /// `CAP_SYS_RESOURCE`
        const SYS_RESOURCE = 1 << linux_raw_sys::general::CAP_SYS_RESOURCE;
        /// `CAP_SYS_TIME`
        const SYS_TIME = 1 << linux_raw_sys::general::CAP_SYS_TIME;
        /// `CAP_SYS_TTY_CONFIG`
        const SYS_TTY_CONFIG = 1 << linux_raw_sys::general::CAP_SYS_TTY_CONFIG;
        /// `CAP_MKNOD`
        const MKNOD = 1 << linux_raw_sys::general::CAP_MKNOD;
        /// `CAP_LEASE`
        const LEASE = 1 << linux_raw_sys::general::CAP_LEASE;
        /// `CAP_AUDIT_WRITE`
        const AUDIT_WRITE = 1 << linux_raw_sys::general::CAP_AUDIT_WRITE;
        /// `CAP_AUDIT_CONTROL`
        const AUDIT_CONTROL = 1 << linux_raw_sys::general::CAP_AUDIT_CONTROL;
        /// `CAP_SETFCAP`
        const SETFCAP = 1 << linux_raw_sys::general::CAP_SETFCAP;
        /// `CAP_MAC_OVERRIDE`
        const MAC_OVERRIDE = 1 << linux_raw_sys::general::CAP_MAC_OVERRIDE;
        /// `CAP_MAC_ADMIN`
        const MAC_ADMIN = 1 << linux_raw_sys::general::CAP_MAC_ADMIN;
        /// `CAP_SYSLOG`
        const SYSLOG = 1 << linux_raw_sys::general::CAP_SYSLOG;
        /// `CAP_WAKE_ALARM`
        const WAKE_ALARM = 1 << linux_raw_sys::general::CAP_WAKE_ALARM;
        /// `CAP_BLOCK_SUSPEND`
        const BLOCK_SUSPEND = 1 << linux_raw_sys::general::CAP_BLOCK_SUSPEND;
        /// `CAP_AUDIT_READ`
        const AUDIT_READ = 1 << linux_raw_sys::general::CAP_AUDIT_READ;
        /// `CAP_PERFMON`
        const PERFMON = 1 << linux_raw_sys::general::CAP_PERFMON;
        /// `CAP_BPF`
        const BPF = 1 << linux_raw_sys::general::CAP_BPF;
        /// `CAP_CHECKPOINT_RESTORE`
        const CHECKPOINT_RESTORE = 1 << linux_raw_sys::general::CAP_CHECKPOINT_RESTORE;

        /// <https://docs.rs/bitflags/*/bitflags/#externally-defined-flags>
        const _ = !0;
    }
}

/// `capget(_LINUX_CAPABILITY_VERSION_3, pid)`
///
/// # References
///  - [Linux]
///
/// [Linux]: https://man7.org/linux/man-pages/man2/capget.2.html
#[inline]
#[doc(alias = "capget")]
pub fn capabilities(pid: Option<Pid>) -> io::Result<CapabilitySets> {
    capget(pid)
}

/// `capset(_LINUX_CAPABILITY_VERSION_3, pid, effective, permitted,
/// inheritable)`
///
/// # References
///  - [Linux]
///
/// [Linux]: https://man7.org/linux/man-pages/man2/capget.2.html
#[inline]
#[doc(alias = "capset")]
pub fn set_capabilities(pid: Option<Pid>, sets: CapabilitySets) -> io::Result<()> {
    capset(pid, sets)
}

#[inline]
#[allow(unsafe_code)]
fn capget(pid: Option<Pid>) -> io::Result<CapabilitySets> {
    let mut data = [MaybeUninit::<linux_raw_sys::general::__user_cap_data_struct>::uninit(); 2];

    let data = {
        let mut header = linux_raw_sys::general::__user_cap_header_struct {
            version: linux_raw_sys::general::_LINUX_CAPABILITY_VERSION_3,
            pid: Pid::as_raw(pid) as backend::c::c_int,
        };

        backend::thread::syscalls::capget(&mut header, &mut data)?;
        // SAFETY: v3 is a 64-bit implementation, so the kernel filled in both
        // data structs.
        unsafe { (data[0].assume_init(), data[1].assume_init()) }
    };

    let effective = u64::from(data.0.effective) | (u64::from(data.1.effective) << u32::BITS);
    let permitted = u64::from(data.0.permitted) | (u64::from(data.1.permitted) << u32::BITS);
    let inheritable = u64::from(data.0.inheritable) | (u64::from(data.1.inheritable) << u32::BITS);

    // The kernel returns a partitioned bitset that we just combined above.
    Ok(CapabilitySets {
        effective: CapabilityFlags::from_bits_retain(effective),
        permitted: CapabilityFlags::from_bits_retain(permitted),
        inheritable: CapabilityFlags::from_bits_retain(inheritable),
    })
}

#[inline]
fn capset(pid: Option<Pid>, sets: CapabilitySets) -> io::Result<()> {
    let mut header = linux_raw_sys::general::__user_cap_header_struct {
        version: linux_raw_sys::general::_LINUX_CAPABILITY_VERSION_3,
        pid: Pid::as_raw(pid) as backend::c::c_int,
    };
    let data = [
        linux_raw_sys::general::__user_cap_data_struct {
            effective: sets.effective.bits() as u32,
            permitted: sets.permitted.bits() as u32,
            inheritable: sets.inheritable.bits() as u32,
        },
        linux_raw_sys::general::__user_cap_data_struct {
            effective: (sets.effective.bits() >> u32::BITS) as u32,
            permitted: (sets.permitted.bits() >> u32::BITS) as u32,
            inheritable: (sets.inheritable.bits() >> u32::BITS) as u32,
        },
    ];

    backend::thread::syscalls::capset(&mut header, &data)
}