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

use virtual_fs::Pipe;

use super::*;
use crate::{
    net::socket::{self, SocketProperties},
    syscalls::*,
};

// FIXME
/// ### `sock_pair()`
/// Create an interconnected socket pair; or at least it's supposed to.
///
/// Currently, this creates a pipe rather than a pair of sockets. Before this
/// syscall was added, wasix-libc would just do pipe2 in its socketpair
/// implementation. Since we fixed pipe2 to return a simplex pipe, that was no
/// longer an option; hence this syscall was added, but the implementation
/// still uses a pipe as the underlying communication mechanism. This is not
/// the correct implementation and needs to be fixed. We hope that the pipe
/// is sufficient for anything that doesn't do socket-specific stuff, such
/// as sending out-of-band packets.
///
/// Note: This is (supposed to be) similar to `socketpair` in POSIX using PF_INET
///
/// ## Parameters
///
/// * `af` - Address family
/// * `socktype` - Socket type, either datagram or stream
/// * `sock_proto` - Socket protocol
///
/// ## Return
///
/// The file descriptor of the socket that has been opened.
#[instrument(level = "trace", skip_all, fields(?af, ?ty, ?pt, sock1 = field::Empty, sock2 = field::Empty), ret)]
pub fn sock_pair<M: MemorySize>(
    mut ctx: FunctionEnvMut<'_, WasiEnv>,
    af: Addressfamily,
    ty: Socktype,
    pt: SockProto,
    ro_sock1: WasmPtr<WasiFd, M>,
    ro_sock2: WasmPtr<WasiFd, M>,
) -> Result<Errno, WasiError> {
    // only certain combinations are supported
    match pt {
        SockProto::Tcp => {
            if ty != Socktype::Stream {
                return Ok(Errno::Notsup);
            }
        }
        SockProto::Udp => {
            if ty != Socktype::Dgram {
                return Ok(Errno::Notsup);
            }
        }
        _ => {}
    }

    // FIXME: currently, socket properties are ignored outright, since they
    // make no sense for the underlying pipe
    let (fd1, fd2) = wasi_try_ok!(sock_pair_internal(&mut ctx, None, None));

    #[cfg(feature = "journal")]
    if ctx.data().enable_journal {
        JournalEffector::save_sock_pair(&mut ctx, fd1, fd2).map_err(|err| {
            tracing::error!("failed to save sock_pair event - {}", err);
            WasiError::Exit(ExitCode::from(Errno::Fault))
        })?;
    }

    let env = ctx.data();
    let (memory, state, inodes) = unsafe { env.get_memory_and_wasi_state_and_inodes(&ctx, 0) };
    wasi_try_mem_ok!(ro_sock1.write(&memory, fd1));
    wasi_try_mem_ok!(ro_sock2.write(&memory, fd2));

    Ok(Errno::Success)
}

pub(crate) fn sock_pair_internal(
    ctx: &mut FunctionEnvMut<'_, WasiEnv>,
    with_fd1: Option<WasiFd>,
    with_fd2: Option<WasiFd>,
) -> Result<(WasiFd, WasiFd), Errno> {
    let env = ctx.data();
    let (memory, state, inodes) = unsafe { env.get_memory_and_wasi_state_and_inodes(&ctx, 0) };
    let (end1, end2) = Pipe::channel();

    let inode1 = state.fs.create_inode_with_default_stat(
        inodes,
        Kind::DuplexPipe { pipe: end1 },
        false,
        "socketpair".into(),
    );
    let inode2 = state.fs.create_inode_with_default_stat(
        inodes,
        Kind::DuplexPipe { pipe: end2 },
        false,
        "socketpair".into(),
    );

    let rights = Rights::all_socket();
    let fd1 = if let Some(fd) = with_fd1 {
        state
            .fs
            .with_fd(
                rights,
                rights,
                Fdflags::empty(),
                Fdflagsext::empty(),
                0,
                inode1,
                fd,
            )
            .map(|_| fd)?
    } else {
        state.fs.create_fd(
            rights,
            rights,
            Fdflags::empty(),
            Fdflagsext::empty(),
            0,
            inode1,
        )?
    };
    let fd2 = if let Some(fd) = with_fd2 {
        state
            .fs
            .with_fd(
                rights,
                rights,
                Fdflags::empty(),
                Fdflagsext::empty(),
                0,
                inode2,
                fd,
            )
            .map(|_| fd)?
    } else {
        state.fs.create_fd(
            rights,
            rights,
            Fdflags::empty(),
            Fdflagsext::empty(),
            0,
            inode2,
        )?
    };
    Span::current().record("end1", fd1);
    Span::current().record("end2", fd2);

    Ok((fd1, fd2))
}