c_ares/
srv.rs

1use std::fmt;
2use std::marker::PhantomData;
3use std::os::raw::{c_int, c_uchar, c_void};
4use std::ptr;
5use std::slice;
6
7use itertools::Itertools;
8
9use crate::error::{Error, Result};
10use crate::panic;
11use crate::utils::hostname_as_str;
12
13/// The result of a successful SRV lookup.
14#[derive(Debug)]
15pub struct SRVResults {
16    srv_reply: *mut c_ares_sys::ares_srv_reply,
17    phantom: PhantomData<c_ares_sys::ares_srv_reply>,
18}
19
20/// The contents of a single SRV record.
21#[derive(Clone, Copy)]
22pub struct SRVResult<'a> {
23    // A single result - reference into an `SRVResults`.
24    srv_reply: &'a c_ares_sys::ares_srv_reply,
25}
26
27impl SRVResults {
28    /// Obtain an `SRVResults` from the response to an SRV lookup.
29    pub fn parse_from(data: &[u8]) -> Result<SRVResults> {
30        let mut srv_reply: *mut c_ares_sys::ares_srv_reply = ptr::null_mut();
31        let parse_status = unsafe {
32            c_ares_sys::ares_parse_srv_reply(data.as_ptr(), data.len() as c_int, &mut srv_reply)
33        };
34        if parse_status == c_ares_sys::ares_status_t::ARES_SUCCESS as i32 {
35            let srv_result = SRVResults::new(srv_reply);
36            Ok(srv_result)
37        } else {
38            Err(Error::from(parse_status))
39        }
40    }
41
42    fn new(srv_reply: *mut c_ares_sys::ares_srv_reply) -> Self {
43        SRVResults {
44            srv_reply,
45            phantom: PhantomData,
46        }
47    }
48
49    /// Returns an iterator over the `SRVResult` values in this `SRVResults`.
50    pub fn iter(&self) -> SRVResultsIter {
51        SRVResultsIter {
52            next: unsafe { self.srv_reply.as_ref() },
53        }
54    }
55}
56
57impl fmt::Display for SRVResults {
58    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
59        let results = self.iter().format("}, {");
60        write!(fmt, "[{{{results}}}]")
61    }
62}
63
64/// Iterator of `SRVResult`s.
65#[derive(Clone, Copy)]
66pub struct SRVResultsIter<'a> {
67    next: Option<&'a c_ares_sys::ares_srv_reply>,
68}
69
70impl<'a> Iterator for SRVResultsIter<'a> {
71    type Item = SRVResult<'a>;
72    fn next(&mut self) -> Option<Self::Item> {
73        let opt_reply = self.next;
74        self.next = opt_reply.and_then(|reply| unsafe { reply.next.as_ref() });
75        opt_reply.map(|reply| SRVResult { srv_reply: reply })
76    }
77}
78
79impl<'a> IntoIterator for &'a SRVResults {
80    type Item = SRVResult<'a>;
81    type IntoIter = SRVResultsIter<'a>;
82
83    fn into_iter(self) -> Self::IntoIter {
84        self.iter()
85    }
86}
87
88impl Drop for SRVResults {
89    fn drop(&mut self) {
90        unsafe { c_ares_sys::ares_free_data(self.srv_reply.cast()) }
91    }
92}
93
94unsafe impl Send for SRVResults {}
95unsafe impl Sync for SRVResults {}
96unsafe impl Send for SRVResult<'_> {}
97unsafe impl Sync for SRVResult<'_> {}
98unsafe impl Send for SRVResultsIter<'_> {}
99unsafe impl Sync for SRVResultsIter<'_> {}
100
101impl<'a> SRVResult<'a> {
102    /// Returns the hostname in this `SRVResult`.
103    pub fn host(self) -> &'a str {
104        unsafe { hostname_as_str(self.srv_reply.host) }
105    }
106
107    /// Returns the weight in this `SRVResult`.
108    pub fn weight(self) -> u16 {
109        self.srv_reply.weight
110    }
111
112    /// Returns the priority in this `SRVResult`.
113    pub fn priority(self) -> u16 {
114        self.srv_reply.priority
115    }
116
117    /// Returns the port in this `SRVResult`.
118    pub fn port(self) -> u16 {
119        self.srv_reply.port
120    }
121}
122
123impl fmt::Display for SRVResult<'_> {
124    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
125        write!(fmt, "Host: {}, ", self.host())?;
126        write!(fmt, "Port: {}, ", self.port())?;
127        write!(fmt, "Priority: {}, ", self.priority())?;
128        write!(fmt, "Weight: {}", self.weight())
129    }
130}
131
132pub(crate) unsafe extern "C" fn query_srv_callback<F>(
133    arg: *mut c_void,
134    status: c_int,
135    _timeouts: c_int,
136    abuf: *mut c_uchar,
137    alen: c_int,
138) where
139    F: FnOnce(Result<SRVResults>) + Send + 'static,
140{
141    ares_callback!(arg.cast::<F>(), status, abuf, alen, SRVResults::parse_from);
142}
c_ares/srv.rs

c_ares/
srv.rs
