Crate dns 

Available on crate feature dns only.

DNS support for Rama.

Resolvers

Rama ships with several client::resolver::DnsResolver implementations. The most commonly used ones are re-exported from client:

• client::NativeDnsResolver — alias for the platform-native resolver: AppleDnsResolver on Apple platforms, WindowsDnsResolver on Windows, LinuxDnsResolver on Linux, and client::TokioDnsResolver (host-backed via tokio) elsewhere. Each is exposed under client when the corresponding target is active.
• client::TokioDnsResolver — host-backed resolver that uses the blocking system getaddrinfo via tokio’s threadpool.
• client::HickoryDnsResolver — pure-Rust resolver from the Hickory DNS project (https://github.com/hickory-dns/hickory-dns); gated behind the hickory feature.
• client::DenyAllDnsResolver — fails every lookup with client::DnsDeniedError; useful when DNS must be disabled.
• client::EmptyDnsResolver — returns no addresses for every lookup.

Implement client::resolver::DnsResolver yourself to plug in any other resolver, and combine resolvers with the chain / tuple / variant adapters under client.

Picking a resolver for high-QPS workloads

On Apple platforms (AppleDnsResolver, via DNSServiceQueryRecord + AsyncFd) and Windows (WindowsDnsResolver, via DnsQueryEx with a completion callback on the system thread pool), the native resolvers are fully asynchronous and scale naturally — no tokio blocking-pool traffic.

LinuxDnsResolver (via res_nsearch / getaddrinfo) and client::TokioDnsResolver (via getaddrinfo) are different: each lookup occupies a tokio blocking-pool thread for the duration of the libc call. Under sustained high-concurrency DNS load (typical for forward proxies) that pool can become a bottleneck. For such workloads prefer the pure-Rust client::HickoryDnsResolver (gated behind the hickory feature), which speaks DNS directly over async UDP/TCP and gives finer control over caching and upstream selection.

Global DNS resolver

Rama uses a process-wide shared DNS resolver by default. If nothing is installed explicitly, it lazily initialises to client::NativeDnsResolver on first use — i.e. the best native resolver for the current platform.

Use client::try_init_global_dns_resolver or client::init_global_dns_resolver to install a different resolver (e.g. client::HickoryDnsResolver under the hickory feature, or your own implementation). This has to happen before the first lookup; both initialisers fail / panic if the global resolver has already been initialised.

client::GlobalDnsResolver is a thin handle that defers fetching the global resolver until it’s actually used — handy when you want to pass a resolver around without forcing it to be constructed yet.

Rama

Crate used by the end-user rama crate and rama crate authors alike.

Learn more about rama:

• Github: https://github.com/plabayo/rama
• Book: https://ramaproxy.org/book/

Modules

client

dial9dial9

Pre-defined dial9 events for DNS lookups.