Crate c_ares[−][src]
Expand description
A safe wrapper for the c-ares
library.
This crate is a fairly faithful wrapper of c-ares
; which is to say that it preserves some of
the complexity of using the underlying library. If you just want to make a DNS query, you
should probably prefer the c-ares-resolver
crate,
which does the hard work for you.
Direct usage of this crate requires you to pay attention to c-ares
as it tells you which
file descriptors it cares about, and to poll for activity on those file descriptors.
This likely requires you to have an event loop or similar with which to integrate.
Still here? Usage of this crate is as follows:
-
Create a
Channel
. -
Make queries on the
Channel
. Queries all take callbacks, which will be called when the query completes. -
Have
c-ares
tell you what file descriptors to listen on for read and / or write events. You can do this either by providing a callback, which is called whenever the set of interesting file descriptors changes, or by querying theChannel
directly either withget_sock()
or withfds()
. -
Do as
c-ares
asks. That is, listen for the events that it requests, on the file descriptors that it cares about. -
When a file descriptor becomes readable or writable, call either
process_fd()
orprocess()
on theChannel
to tellc-ares
what has happened. -
If you have queries pending and don’t see events happening, you still need to call either
process_fd()
orprocess()
at some point anyway - to givec-ares
an opportunity to process any requests that have timed out.
Complete examples showing how to use the library can be found here.
Structs
The contents of a single AAAA record.
The result of a successful AAAA lookup.
Iterator of AAAAResult
s.
The contents of a single A record.
The result of a successful A lookup.
Iterator of AResult
s.
The contents of a single CAA record.
The result of a successful CAA lookup.
Iterator of CAAResult
s.
The result of a successful CNAME lookup.
A channel for name service lookups.
Flags that may be passed when initializing a Channel
.
Information about the set of sockets that c-ares
is interested in, as returned by
get_sock()
.
Iterator for sockets of interest to c-ares
.
Iterator of IpAddr
s.
Iterator of &'a CStr
s.
The result of a successful host lookup.
The contents of a single MX record.
The result of a successful MX lookup.
Iterator of MXResult
s.
The contents of a single NAPTR record.
The result of a successful NAPTR lookup.
Iterator of NAPTRResult
s.
Flags that may be provided on a call to get_name_info()
.
The result of a successful NS lookup.
The result of a successful name-info lookup.
Used to configure the behaviour of the name resolver.
The result of a successful PTR lookup.
The result of a successful SOA lookup.
The contents of a single SRV record.
The result of a successful SRV lookup.
Iterator of SRVResult
s.
The contents of a single TXT record.
The result of a successful TXT lookup.
Iterator of TXTResult
s.
The contents of a single URI record.
The result of a successful URI lookup.
Iterator of URIResult
s.
Enums
Constants
An invalid socket / file descriptor. Use this to represent ‘no action’ when calling
process_fd()
on a channel.
Functions
Get the version number of the underlying c-ares
library.