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
164
165
166
167
168
169
170
171
172
173
174
175

use std::ffi::CStr;
use std::fmt;
use std::marker::PhantomData;
use std::mem;
use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
use std::os::raw::{c_char, c_int};
use std::slice;
use std::str;

use c_ares_sys;
use c_types;
use itertools::Itertools;

use types::AddressFamily;
use utils::address_family;

#[derive(Debug)]
pub struct HostentOwned {
    inner: *mut c_types::hostent,
    phantom: PhantomData<c_types::hostent>,
}

impl HostentOwned {
    pub fn new(hostent: *mut c_types::hostent) -> HostentOwned {
        HostentOwned {
            inner: hostent,
            phantom: PhantomData,
        }
    }
}

impl Drop for HostentOwned {
    fn drop(&mut self) {
        unsafe {
            c_ares_sys::ares_free_hostent(self.inner);
        }
    }
}

#[derive(Clone, Copy)]
pub struct HostentBorrowed<'a> {
    inner: &'a c_types::hostent,
}

impl<'a> HostentBorrowed<'a> {
    pub fn new(hostent: &'a c_types::hostent) -> HostentBorrowed<'a> {
        HostentBorrowed { inner: hostent }
    }
}

pub trait HasHostent {
    fn hostent(&self) -> &c_types::hostent;

    fn hostname(&self) -> &str {
        unsafe {
            let c_str = CStr::from_ptr(self.hostent().h_name);
            str::from_utf8_unchecked(c_str.to_bytes())
        }
    }

    fn addresses(&self) -> HostAddressResultsIter {
        // h_addrtype is `c_short` on windows, `c_int` on unix.  Tell clippy to
        // allow the identity conversion in the latter case.
        #[cfg_attr(feature = "cargo-clippy", allow(identity_conversion))]
        let addrtype = c_int::from(self.hostent().h_addrtype);
        HostAddressResultsIter {
            family: address_family(addrtype),
            next: unsafe { &*(self.hostent().h_addr_list as *const _) },
        }
    }

    fn aliases(&self) -> HostAliasResultsIter {
        HostAliasResultsIter {
            next: unsafe { &*(self.hostent().h_aliases as *const _) },
        }
    }

    fn display(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
        write!(fmt, "Hostname: {}, ", self.hostname())?;
        let addresses = self.addresses().format(", ");
        write!(fmt, "Addresses: [{}]", addresses)?;
        let aliases = self.aliases().format(", ");
        write!(fmt, "Aliases: [{}]", aliases)
    }
}

impl HasHostent for HostentOwned {
    fn hostent(&self) -> &c_types::hostent {
        unsafe { &*self.inner }
    }
}

impl<'a> HasHostent for HostentBorrowed<'a> {
    fn hostent(&self) -> &c_types::hostent {
        self.inner
    }
}

unsafe impl Send for HostentOwned {}
unsafe impl Sync for HostentOwned {}

unsafe impl<'a> Send for HostentBorrowed<'a> {}
unsafe impl<'a> Sync for HostentBorrowed<'a> {}

/// Iterator of `IpAddr`s.
#[derive(Clone, Copy, Debug)]
pub struct HostAddressResultsIter<'a> {
    family: Option<AddressFamily>,
    next: &'a *const c_char,
}

// Get an IpAddr from a family and an array of bytes, as found in a `hostent`.
unsafe fn ip_address_from_bytes(family: AddressFamily, h_addr: *const u8) -> Option<IpAddr> {
    match family {
        AddressFamily::INET => {
            let source = slice::from_raw_parts(h_addr, 4);
            let mut bytes: [u8; 4] = mem::uninitialized();
            bytes.copy_from_slice(source);
            let ipv4 = Ipv4Addr::from(bytes);
            Some(IpAddr::V4(ipv4))
        }
        AddressFamily::INET6 => {
            let source = slice::from_raw_parts(h_addr, 16);
            let mut bytes: [u8; 16] = mem::uninitialized();
            bytes.copy_from_slice(source);
            let ipv6 = Ipv6Addr::from(bytes);
            Some(IpAddr::V6(ipv6))
        }
        _ => None,
    }
}

impl<'a> Iterator for HostAddressResultsIter<'a> {
    type Item = IpAddr;
    fn next(&mut self) -> Option<Self::Item> {
        let h_addr = *self.next;
        if h_addr.is_null() {
            None
        } else {
            unsafe {
                self.next = &*(self.next as *const *const c_char).offset(1);
                self.family
                    .and_then(|family| ip_address_from_bytes(family, h_addr as *const u8))
            }
        }
    }
}

unsafe impl<'a> Send for HostAddressResultsIter<'a> {}
unsafe impl<'a> Sync for HostAddressResultsIter<'a> {}

/// Iterator of `&'a str`s.
#[derive(Clone, Copy, Debug)]
pub struct HostAliasResultsIter<'a> {
    next: &'a *const c_char,
}

impl<'a> Iterator for HostAliasResultsIter<'a> {
    type Item = &'a str;
    fn next(&mut self) -> Option<Self::Item> {
        let h_alias = *self.next;
        if h_alias.is_null() {
            None
        } else {
            unsafe {
                self.next = &*(self.next as *const *const c_char).offset(1);
                let c_str = CStr::from_ptr(h_alias);
                Some(str::from_utf8_unchecked(c_str.to_bytes()))
            }
        }
    }
}

unsafe impl<'a> Send for HostAliasResultsIter<'a> {}
unsafe impl<'a> Sync for HostAliasResultsIter<'a> {}