ringline 0.1.0

Async I/O runtime with io_uring (Linux) and mio (cross-platform) backends
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

//! Portable sockaddr conversion helpers shared across backends.

use std::net::SocketAddr;

/// Convert a libc sockaddr_storage to a std SocketAddr.
pub(crate) fn sockaddr_to_socket_addr(
    addr: &libc::sockaddr_storage,
    len: u32,
) -> Option<SocketAddr> {
    use std::net::{Ipv4Addr, Ipv6Addr, SocketAddrV4, SocketAddrV6};
    match addr.ss_family as libc::c_int {
        libc::AF_INET if len >= std::mem::size_of::<libc::sockaddr_in>() as u32 => {
            let sa = unsafe { &*(addr as *const _ as *const libc::sockaddr_in) };
            let ip = Ipv4Addr::from(u32::from_be(sa.sin_addr.s_addr));
            let port = u16::from_be(sa.sin_port);
            Some(SocketAddr::V4(SocketAddrV4::new(ip, port)))
        }
        libc::AF_INET6 if len >= std::mem::size_of::<libc::sockaddr_in6>() as u32 => {
            let sa = unsafe { &*(addr as *const _ as *const libc::sockaddr_in6) };
            let ip = Ipv6Addr::from(sa.sin6_addr.s6_addr);
            let port = u16::from_be(sa.sin6_port);
            Some(SocketAddr::V6(SocketAddrV6::new(
                ip,
                port,
                sa.sin6_flowinfo,
                sa.sin6_scope_id,
            )))
        }
        _ => None,
    }
}

/// Convert a libc sockaddr_storage to a `PeerAddr` (TCP or Unix).
#[allow(dead_code)]
pub(crate) fn sockaddr_to_peer_addr(
    addr: &libc::sockaddr_storage,
    len: u32,
) -> Option<crate::connection::PeerAddr> {
    match addr.ss_family as libc::c_int {
        libc::AF_INET | libc::AF_INET6 => {
            sockaddr_to_socket_addr(addr, len).map(crate::connection::PeerAddr::Tcp)
        }
        libc::AF_UNIX => {
            let sa = unsafe { &*(addr as *const _ as *const libc::sockaddr_un) };
            let path_offset = memoffset(sa);
            let path_len = (len as usize).saturating_sub(path_offset);
            if path_len == 0 {
                Some(crate::connection::PeerAddr::Unix(std::path::PathBuf::new()))
            } else {
                #[allow(clippy::unnecessary_cast)]
                let bytes: &[u8] = unsafe {
                    std::slice::from_raw_parts(sa.sun_path.as_ptr() as *const u8, path_len)
                };
                let end = bytes.iter().position(|&b| b == 0).unwrap_or(path_len);
                let path = std::str::from_utf8(&bytes[..end]).unwrap_or("");
                Some(crate::connection::PeerAddr::Unix(std::path::PathBuf::from(
                    path,
                )))
            }
        }
        _ => None,
    }
}

/// Offset of `sun_path` within `sockaddr_un`.
fn memoffset(sa: &libc::sockaddr_un) -> usize {
    let base = sa as *const _ as usize;
    let path = sa.sun_path.as_ptr() as usize;
    path - base
}

/// Write a Unix socket path into a sockaddr_storage, return the address length.
pub(crate) fn unix_path_to_sockaddr(
    path: &std::path::Path,
    storage: &mut libc::sockaddr_storage,
) -> u32 {
    unsafe {
        std::ptr::write_bytes(
            storage as *mut _ as *mut u8,
            0,
            std::mem::size_of::<libc::sockaddr_storage>(),
        );
    }
    let sa = storage as *mut _ as *mut libc::sockaddr_un;
    unsafe {
        (*sa).sun_family = libc::AF_UNIX as libc::sa_family_t;
    }
    let path_bytes = path.as_os_str().as_encoded_bytes();
    let max_len = std::mem::size_of_val(unsafe { &(*sa).sun_path }) - 1;
    let copy_len = path_bytes.len().min(max_len);
    #[allow(clippy::unnecessary_cast)]
    unsafe {
        std::ptr::copy_nonoverlapping(
            path_bytes.as_ptr(),
            (*sa).sun_path.as_mut_ptr() as *mut u8,
            copy_len,
        );
    }
    let sa_ref = unsafe { &*sa };
    let offset = memoffset(sa_ref);
    (offset + copy_len + 1) as u32
}

/// Write a SocketAddr into a sockaddr_storage, return the address length.
pub(crate) fn socket_addr_to_sockaddr(
    addr: SocketAddr,
    storage: &mut libc::sockaddr_storage,
) -> u32 {
    unsafe {
        std::ptr::write_bytes(
            storage as *mut _ as *mut u8,
            0,
            std::mem::size_of::<libc::sockaddr_storage>(),
        );
    }
    match addr {
        SocketAddr::V4(v4) => {
            let sa = storage as *mut _ as *mut libc::sockaddr_in;
            unsafe {
                (*sa).sin_family = libc::AF_INET as libc::sa_family_t;
                (*sa).sin_port = v4.port().to_be();
                (*sa).sin_addr.s_addr = u32::from_ne_bytes(v4.ip().octets());
            }
            std::mem::size_of::<libc::sockaddr_in>() as u32
        }
        SocketAddr::V6(v6) => {
            let sa = storage as *mut _ as *mut libc::sockaddr_in6;
            unsafe {
                (*sa).sin6_family = libc::AF_INET6 as libc::sa_family_t;
                (*sa).sin6_port = v6.port().to_be();
                (*sa).sin6_flowinfo = v6.flowinfo();
                (*sa).sin6_addr.s6_addr = v6.ip().octets();
                (*sa).sin6_scope_id = v6.scope_id();
            }
            std::mem::size_of::<libc::sockaddr_in6>() as u32
        }
    }
}