c_ares/

flags.rs

use bitflags::bitflags;
bitflags!(
    /// Flags that may be passed when initializing a `Channel`.
    #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
    pub struct Flags: i32 {
        /// Always use TCP queries (the "virtual circuit") instead of UDP queries.  Normally, TCP
        /// is only used if a UDP query yields a truncated result.
        const USEVC = c_ares_sys::ARES_FLAG_USEVC;

        /// Only query the first server in the list of servers to query.
        const PRIMARY = c_ares_sys::ARES_FLAG_PRIMARY;

        /// If a truncated response to a UDP query is received, do not fall back to TCP; simply
        /// continue on with the truncated response.
        const IGNTC = c_ares_sys::ARES_FLAG_IGNTC;

        /// Do not set the "recursion desired" bit on outgoing queries, so that the name server
        /// being contacted will not try to fetch the answer from other servers if it doesn't know
        /// the answer locally.
        const NORECURSE = c_ares_sys::ARES_FLAG_NORECURSE;

        /// Do not close communications sockets when the number of active queries drops to zero.
        const STAYOPEN = c_ares_sys::ARES_FLAG_STAYOPEN;

        /// Do not use the default search domains; only query hostnames as-is or as aliases.
        const NOSEARCH = c_ares_sys::ARES_FLAG_NOSEARCH;

        /// Do not honor the HOSTALIASES environment variable, which normally specifies a file of
        /// hostname translations.
        const NOALIASES = c_ares_sys::ARES_FLAG_NOALIASES;

        /// Do not discard responses with the SERVFAIL, NOTIMP, or REFUSED response code or
        /// responses whose questions don't match the questions in the request. Primarily useful
        /// for writing clients which might be used to test or debug name servers.
        const NOCHECKRESP = c_ares_sys::ARES_FLAG_NOCHECKRESP;

        /// Include an EDNS pseudo-resource record (RFC 2671) in generated requests.  As of c-ares
        /// v1.22, this is on by default if flags are otherwise not set.
        const EDNS = c_ares_sys::ARES_FLAG_EDNS;

        /// Do not attempt to add a default local named server if there are no other servers
        /// available.  Instead, fail initialization with ARES_ENOSERVER.
        const NO_DFLT_SVR = c_ares_sys::ARES_FLAG_NO_DFLT_SVR;

        /// Enable support for DNS 0x20 as per
        /// https://datatracker.ietf.org/doc/html/draft-vixie-dnsext-dns0x20-00 which adds
        /// additional entropy to the request by randomizing the case of the query name.
        const DNS_0X20 = c_ares_sys::ARES_FLAG_DNS0x20;
    }
);