tor_proto/stream/
params.rs

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1//! Declares a type to configure new streams.
2
3use tor_cell::relaycell::msg::{BeginFlags, IpVersionPreference};
4
5/// A set of preferences used to declare how a new stream should be opened.
6#[derive(Clone, Debug, Default)]
7pub struct StreamParameters {
8    /// Preferred IP version to use.
9    ip_version: IpVersionPreference,
10    /// True if we are requesting an optimistic stream.
11    optimistic: bool,
12    /// True if we are suppressing hostnames
13    suppress_hostname: bool,
14    /// True if we are suppressing flags.
15    suppress_begin_flags: bool,
16}
17
18impl StreamParameters {
19    /// Create a new [`StreamParameters`] using default settings.
20    pub fn new() -> Self {
21        Self::default()
22    }
23
24    /// Configure this `StreamParameters` to include no flags in any
25    /// `BEGIN` message it generates.
26    ///
27    /// This is used to implement onion services.  It may make other
28    /// operations inoperable.
29    pub fn suppress_begin_flags(&mut self) -> &mut Self {
30        self.suppress_begin_flags = true;
31        self
32    }
33
34    /// Configure this `StreamParameters` to suppress hostnames in the
35    /// BEGIN messages.
36    ///
37    /// This is used to implement onion services. It will make other
38    /// kinds of connections not work.
39    pub fn suppress_hostname(&mut self) -> &mut Self {
40        self.suppress_hostname = true;
41        self
42    }
43
44    /// Configure which IP version (IPv4 or IPv6) you'd like to request,
45    /// if you're connecting to a hostname.
46    ///
47    /// The default is to allow either version, but to prefer IPv4.
48    pub fn ip_version(&mut self, preference: IpVersionPreference) -> &mut Self {
49        self.ip_version = preference;
50        self
51    }
52
53    /// Configure whether the stream should be opened "optimistically."
54    ///
55    /// By default, streams are not "optimistic". When you call
56    /// [`ClientCirc::begin_stream()`](crate::tunnel::circuit::ClientCirc::begin_stream),
57    /// the function won't give you a stream until the exit node has
58    /// confirmed that it has successfully opened a connection to your
59    /// target address.  It's safer to wait in this way, but it is slower:
60    /// it takes an entire round trip to get your confirmation.
61    ///
62    /// If a stream _is_ configured to be "optimistic", then
63    /// `ClientCirc::begin_stream()` will return the stream
64    /// immediately, without waiting for an answer from the exit.  You
65    /// can start sending data on the stream right away, though of
66    /// course this data will be lost if the connection is not
67    /// actually successful.
68    pub fn optimistic(&mut self, optimistic: bool) -> &mut Self {
69        self.optimistic = optimistic;
70        self
71    }
72
73    /// Crate-internal: Return true if the stream is optimistic.
74    pub(crate) fn is_optimistic(&self) -> bool {
75        self.optimistic
76    }
77
78    /// Crate-internal: Get a set of [`BeginFlags`] for this stream.
79    pub(crate) fn begin_flags(&self) -> BeginFlags {
80        if self.suppress_begin_flags {
81            0.into()
82        } else {
83            self.ip_version.into()
84        }
85    }
86
87    /// Crate-internal: Return true if we are suppressing hostnames.
88    pub(crate) fn suppressing_hostname(&self) -> bool {
89        self.suppress_hostname
90    }
91}
tor_proto/stream/params.rs

tor_proto/stream/
params.rs
