1// NOTE: Code in this file is heavily based on work done in PR 13 from the tokio-uds repository on
2// GitHub.
3//
4// For reference, the link is here: https://github.com/tokio-rs/tokio-uds/pull/13
5// Credit to Martin Habovštiak (GitHub username Kixunil) and contributors for this work.
6
7use libc::{gid_t, pid_t, uid_t};
8
9/// Credentials for a UNIX process for credentials passing.
10#[unstable(feature = "peer_credentials_unix_socket", issue = "42839", reason = "unstable")]
11#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
12pub struct UCred {
13 /// The UID part of the peer credential. This is the effective UID of the process at the domain
14 /// socket's endpoint.
15 pub uid: uid_t,
16 /// The GID part of the peer credential. This is the effective GID of the process at the domain
17 /// socket's endpoint.
18 pub gid: gid_t,
19 /// The PID part of the peer credential. This field is optional because the PID part of the
20 /// peer credentials is not supported on every platform. On platforms where the mechanism to
21 /// discover the PID exists, this field will be populated to the PID of the process at the
22 /// domain socket's endpoint. Otherwise, it will be set to None.
23 pub pid: Option<pid_t>,
24}
25
26#[cfg(target_vendor = "apple")]
27pub(super) use self::impl_apple::peer_cred;
28#[cfg(any(
29 target_os = "dragonfly",
30 target_os = "freebsd",
31 target_os = "openbsd",
32 target_os = "netbsd",
33 target_os = "nto"
34))]
35pub(super) use self::impl_bsd::peer_cred;
36#[cfg(any(target_os = "android", target_os = "linux", target_os = "cygwin"))]
37pub(super) use self::impl_linux::peer_cred;
38
39#[cfg(any(target_os = "linux", target_os = "android", target_os = "cygwin"))]
40mod impl_linux {
41 use libc::{SO_PEERCRED, SOL_SOCKET, c_void, getsockopt, socklen_t, ucred};
42
43 use super::UCred;
44 use crate::io;
45 use crate::os::unix::io::AsRawFd;
46 use crate::os::unix::net::UnixStream;
47
48 pub fn peer_cred(socket: &UnixStream) -> io::Result<UCred> {
49 let ucred_size = size_of::<ucred>();
50
51 // Trivial sanity checks.
52 assert!(size_of::<u32>() <= size_of::<usize>());
53 assert!(ucred_size <= u32::MAX as usize);
54
55 let mut ucred_size = ucred_size as socklen_t;
56 let mut ucred: ucred = ucred { pid: 1, uid: 1, gid: 1 };
57
58 unsafe {
59 let ret = getsockopt(
60 socket.as_raw_fd(),
61 SOL_SOCKET,
62 SO_PEERCRED,
63 (&raw mut ucred) as *mut c_void,
64 &mut ucred_size,
65 );
66
67 if ret == 0 && ucred_size as usize == size_of::<ucred>() {
68 Ok(UCred { uid: ucred.uid, gid: ucred.gid, pid: Some(ucred.pid) })
69 } else {
70 Err(io::Error::last_os_error())
71 }
72 }
73 }
74}
75
76#[cfg(any(
77 target_os = "dragonfly",
78 target_os = "freebsd",
79 target_os = "openbsd",
80 target_os = "netbsd",
81 target_os = "nto",
82))]
83mod impl_bsd {
84 use super::UCred;
85 use crate::io;
86 use crate::os::unix::io::AsRawFd;
87 use crate::os::unix::net::UnixStream;
88
89 pub fn peer_cred(socket: &UnixStream) -> io::Result<UCred> {
90 let mut cred = UCred { uid: 1, gid: 1, pid: None };
91 unsafe {
92 let ret = libc::getpeereid(socket.as_raw_fd(), &mut cred.uid, &mut cred.gid);
93
94 if ret == 0 { Ok(cred) } else { Err(io::Error::last_os_error()) }
95 }
96 }
97}
98
99#[cfg(target_vendor = "apple")]
100mod impl_apple {
101 use libc::{LOCAL_PEERPID, SOL_LOCAL, c_void, getpeereid, getsockopt, pid_t, socklen_t};
102
103 use super::UCred;
104 use crate::io;
105 use crate::os::unix::io::AsRawFd;
106 use crate::os::unix::net::UnixStream;
107
108 pub fn peer_cred(socket: &UnixStream) -> io::Result<UCred> {
109 let mut cred = UCred { uid: 1, gid: 1, pid: None };
110 unsafe {
111 let ret = getpeereid(socket.as_raw_fd(), &mut cred.uid, &mut cred.gid);
112
113 if ret != 0 {
114 return Err(io::Error::last_os_error());
115 }
116
117 let mut pid: pid_t = 1;
118 let mut pid_size = size_of::<pid_t>() as socklen_t;
119
120 let ret = getsockopt(
121 socket.as_raw_fd(),
122 SOL_LOCAL,
123 LOCAL_PEERPID,
124 (&raw mut pid) as *mut c_void,
125 &mut pid_size,
126 );
127
128 if ret == 0 && pid_size as usize == size_of::<pid_t>() {
129 cred.pid = Some(pid);
130 Ok(cred)
131 } else {
132 Err(io::Error::last_os_error())
133 }
134 }
135 }
136}
137