rsurl 0.1.7

A pure-Rust implementation of curl. Library, C FFI, and CLI for HTTP/HTTPS/FTP/FTPS.
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
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

//! The object-safe byte-stream trait that connectors hand back.
//!
//! A [`Connector`](crate::net::Connector) returns a `Box<dyn NetStream>` — a
//! plaintext, TCP-equivalent bidirectional pipe to the target. It is only the
//! *plaintext* layer: every protocol in this crate sets its socket timeouts
//! before any TLS upgrade, and the TLS layer ([`crate::tls::connect_over`])
//! requires merely `Read + Write`, so it can wrap a `Box<dyn NetStream>`
//! directly without `NetStream` needing to model the encrypted layer.

use std::io::{self, Read, Write};
use std::net::{Shutdown, SocketAddr, TcpStream};
use std::time::Duration;

/// A plaintext, TCP-equivalent byte stream produced by a
/// [`Connector`](crate::net::Connector).
///
/// Object-safe (`Box<dyn NetStream>`) and `Read + Write + Send` so it can be
/// stored in protocol state, handed to [`crate::tls::connect_over`], and used
/// from worker threads. The extra methods mirror the subset of
/// [`std::net::TcpStream`]'s API the protocol backends actually use.
pub trait NetStream: Read + Write + Send {
    /// See [`TcpStream::set_read_timeout`].
    fn set_read_timeout(&self, dur: Option<Duration>) -> io::Result<()>;
    /// See [`TcpStream::set_write_timeout`].
    fn set_write_timeout(&self, dur: Option<Duration>) -> io::Result<()>;
    /// See [`TcpStream::peer_addr`].
    fn peer_addr(&self) -> io::Result<SocketAddr>;
    /// See [`TcpStream::local_addr`].
    fn local_addr(&self) -> io::Result<SocketAddr>;
    /// See [`TcpStream::shutdown`].
    fn shutdown(&self, how: Shutdown) -> io::Result<()>;
    /// Boxed analogue of [`TcpStream::try_clone`] — a second owned handle to
    /// the same connection (the DICT backend needs an independent writer).
    fn try_clone_box(&self) -> io::Result<Box<dyn NetStream>>;
}

impl NetStream for TcpStream {
    fn set_read_timeout(&self, dur: Option<Duration>) -> io::Result<()> {
        TcpStream::set_read_timeout(self, dur)
    }
    fn set_write_timeout(&self, dur: Option<Duration>) -> io::Result<()> {
        TcpStream::set_write_timeout(self, dur)
    }
    fn peer_addr(&self) -> io::Result<SocketAddr> {
        TcpStream::peer_addr(self)
    }
    fn local_addr(&self) -> io::Result<SocketAddr> {
        TcpStream::local_addr(self)
    }
    fn shutdown(&self, how: Shutdown) -> io::Result<()> {
        TcpStream::shutdown(self, how)
    }
    fn try_clone_box(&self) -> io::Result<Box<dyn NetStream>> {
        Ok(Box::new(TcpStream::try_clone(self)?))
    }
}

#[cfg(unix)]
impl NetStream for std::os::unix::net::UnixStream {
    fn set_read_timeout(&self, dur: Option<Duration>) -> io::Result<()> {
        std::os::unix::net::UnixStream::set_read_timeout(self, dur)
    }
    fn set_write_timeout(&self, dur: Option<Duration>) -> io::Result<()> {
        std::os::unix::net::UnixStream::set_write_timeout(self, dur)
    }
    fn peer_addr(&self) -> io::Result<SocketAddr> {
        // Unix sockets have no IP peer address.
        Err(io::Error::new(
            io::ErrorKind::Unsupported,
            "peer_addr unavailable on a Unix-domain socket",
        ))
    }
    fn local_addr(&self) -> io::Result<SocketAddr> {
        Err(io::Error::new(
            io::ErrorKind::Unsupported,
            "local_addr unavailable on a Unix-domain socket",
        ))
    }
    fn shutdown(&self, how: Shutdown) -> io::Result<()> {
        std::os::unix::net::UnixStream::shutdown(self, how)
    }
    fn try_clone_box(&self) -> io::Result<Box<dyn NetStream>> {
        Ok(Box::new(std::os::unix::net::UnixStream::try_clone(self)?))
    }
}

// `Read`/`Write` for `Box<dyn NetStream>` come for free from the std blanket
// impls `impl<T: Read + ?Sized> Read for Box<T>` (and the `Write` analogue),
// since `dyn NetStream: Read + Write`. The `NetStream` methods are reachable
// on a `Box<dyn NetStream>` value through auto-deref, so no forwarding impl is
// required here.

/// A protocol transport that is either plaintext or TLS-wrapped, with support
/// for an in-place STARTTLS-style upgrade. Shared by the line-oriented protocol
/// backends (ftp, imap, smtp, pop3, ldap): modelling the transport as an enum
/// (rather than a generic `S: Read + Write`) is what lets [`upgrade`] swap a
/// `Plain` connection for a `Tls` one wrapping the very same socket in place.
///
/// `Tls` is boxed because the active TLS backend's stream is much larger than a
/// bare `Box<dyn NetStream>`, and clippy flags the variant-size mismatch.
///
/// [`upgrade`]: MaybeTlsStream::upgrade
pub(crate) enum MaybeTlsStream {
    Plain(Box<dyn NetStream>),
    Tls(Box<crate::tls::TlsStream<Box<dyn NetStream>>>),
    /// Transient placeholder held only while [`upgrade`](MaybeTlsStream::upgrade)
    /// moves the inner socket out to hand it to the TLS handshake; reads and
    /// writes error out. In steady state a transport is only `Plain` or `Tls`.
    Upgrading,
}

impl MaybeTlsStream {
    /// True for a plaintext (non-TLS) transport.
    pub(crate) fn is_plain(&self) -> bool {
        matches!(self, Self::Plain(_))
    }

    /// Upgrade a plaintext transport to TLS in place (RFC 2595 / RFC 3207
    /// STARTTLS), verifying `host` as the SNI / certificate name — exactly as an
    /// implicit-TLS scheme does. Errors, leaving the transport unchanged, if it
    /// is not currently plaintext.
    pub(crate) fn upgrade(&mut self, host: &str) -> crate::error::Result<()> {
        let plain = match std::mem::replace(self, Self::Upgrading) {
            Self::Plain(s) => s,
            other => {
                *self = other;
                return Err(crate::error::Error::BadResponse(
                    "STARTTLS requested on a non-plaintext connection".into(),
                ));
            }
        };
        let tls = crate::tls::connect_over(plain, host)?;
        *self = Self::Tls(Box::new(tls));
        Ok(())
    }
}

impl Read for MaybeTlsStream {
    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
        match self {
            Self::Plain(s) => s.read(buf),
            Self::Tls(s) => s.read(buf),
            Self::Upgrading => Err(io::Error::other("tls upgrade in progress")),
        }
    }
}

impl Write for MaybeTlsStream {
    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
        match self {
            Self::Plain(s) => s.write(buf),
            Self::Tls(s) => s.write(buf),
            Self::Upgrading => Err(io::Error::other("tls upgrade in progress")),
        }
    }
    fn flush(&mut self) -> io::Result<()> {
        match self {
            Self::Plain(s) => s.flush(),
            Self::Tls(s) => s.flush(),
            Self::Upgrading => Err(io::Error::other("tls upgrade in progress")),
        }
    }
}