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

//! Unix peer credentials.

// NOTE: Code in this file is heavily based on work done in PR 13 from the tokio-uds repository on
//       GitHub.
//
//       For reference, the link is here: https://github.com/tokio-rs/tokio-uds/pull/13
//       Credit to Martin Habovštiak (GitHub username Kixunil) and contributors for this work.

use libc::{gid_t, pid_t, uid_t};

/// Credentials for a UNIX process for credentials passing.
#[unstable(feature = "peer_credentials_unix_socket", issue = "42839", reason = "unstable")]
#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
pub struct UCred {
    /// The UID part of the peer credential. This is the effective UID of the process at the domain
    /// socket's endpoint.
    pub uid: uid_t,
    /// The GID part of the peer credential. This is the effective GID of the process at the domain
    /// socket's endpoint.
    pub gid: gid_t,
    /// The PID part of the peer credential. This field is optional because the PID part of the
    /// peer credentials is not supported on every platform. On platforms where the mechanism to
    /// discover the PID exists, this field will be populated to the PID of the process at the
    /// domain socket's endpoint. Otherwise, it will be set to None.
    pub pid: Option<pid_t>,
}

#[cfg(any(target_os = "android", target_os = "linux"))]
pub use self::impl_linux::peer_cred;

#[cfg(any(
    target_os = "dragonfly",
    target_os = "freebsd",
    target_os = "openbsd",
    target_os = "netbsd"
))]
pub use self::impl_bsd::peer_cred;

#[cfg(any(target_os = "macos", target_os = "ios",))]
pub use self::impl_mac::peer_cred;

#[cfg(any(target_os = "linux", target_os = "android"))]
pub mod impl_linux {
    use super::UCred;
    use crate::os::unix::io::AsRawFd;
    use crate::os::unix::net::UnixStream;
    use crate::{io, mem};
    use libc::{c_void, getsockopt, socklen_t, ucred, SOL_SOCKET, SO_PEERCRED};

    pub fn peer_cred(socket: &UnixStream) -> io::Result<UCred> {
        let ucred_size = mem::size_of::<ucred>();

        // Trivial sanity checks.
        assert!(mem::size_of::<u32>() <= mem::size_of::<usize>());
        assert!(ucred_size <= u32::MAX as usize);

        let mut ucred_size = ucred_size as socklen_t;
        let mut ucred: ucred = ucred { pid: 1, uid: 1, gid: 1 };

        unsafe {
            let ret = getsockopt(
                socket.as_raw_fd(),
                SOL_SOCKET,
                SO_PEERCRED,
                &mut ucred as *mut ucred as *mut c_void,
                &mut ucred_size,
            );

            if ret == 0 && ucred_size as usize == mem::size_of::<ucred>() {
                Ok(UCred { uid: ucred.uid, gid: ucred.gid, pid: Some(ucred.pid) })
            } else {
                Err(io::Error::last_os_error())
            }
        }
    }
}

#[cfg(any(
    target_os = "dragonfly",
    target_os = "freebsd",
    target_os = "openbsd",
    target_os = "netbsd"
))]
pub mod impl_bsd {
    use super::UCred;
    use crate::io;
    use crate::os::unix::io::AsRawFd;
    use crate::os::unix::net::UnixStream;

    pub fn peer_cred(socket: &UnixStream) -> io::Result<UCred> {
        let mut cred = UCred { uid: 1, gid: 1, pid: None };
        unsafe {
            let ret = libc::getpeereid(socket.as_raw_fd(), &mut cred.uid, &mut cred.gid);

            if ret == 0 { Ok(cred) } else { Err(io::Error::last_os_error()) }
        }
    }
}

#[cfg(any(target_os = "macos", target_os = "ios",))]
pub mod impl_mac {
    use super::UCred;
    use crate::os::unix::io::AsRawFd;
    use crate::os::unix::net::UnixStream;
    use crate::{io, mem};
    use libc::{c_void, getpeereid, getsockopt, pid_t, socklen_t, LOCAL_PEERPID, SOL_LOCAL};

    pub fn peer_cred(socket: &UnixStream) -> io::Result<UCred> {
        let mut cred = UCred { uid: 1, gid: 1, pid: None };
        unsafe {
            let ret = getpeereid(socket.as_raw_fd(), &mut cred.uid, &mut cred.gid);

            if ret != 0 {
                return Err(io::Error::last_os_error());
            }

            let mut pid: pid_t = 1;
            let mut pid_size = mem::size_of::<pid_t>() as socklen_t;

            let ret = getsockopt(
                socket.as_raw_fd(),
                SOL_LOCAL,
                LOCAL_PEERPID,
                &mut pid as *mut pid_t as *mut c_void,
                &mut pid_size,
            );

            if ret == 0 && pid_size as usize == mem::size_of::<pid_t>() {
                cred.pid = Some(pid);
                Ok(cred)
            } else {
                Err(io::Error::last_os_error())
            }
        }
    }
}