ch4 - DNS Stub Resolver CLI

ch4 is a DNS Stub Resolver CLI tool built around rsdns.

ch4's primary goal is to expose rsdns's capabilities in a concise manner. It can be used as a simple substitute for dig, with which it tries to be mostly compatible.

ch4 by default uses the tokio async runtime and the corresponding rsdns resolver. It can be built with all resolvers and async runtimes supported by rsdns via the same set of features net-tokio, net-async-std, net-smol and net-std.

Features

  1. Built on Linux, Windows, and MacOS
  2. Auto-detection of operating system's default nameserver
  3. Supported RFCs are listed in rsdns

Installation

shell cargo install ch4

ch4 currently doesn't provide pre-built binaries. See rustrup.rs for installation of cargo and the Rust toolchain.

Examples

Nameserver address can be specified with @ prefix.

```shell $> ch4 @8.8.8.8 AAAA docs.rs

; <<>> ch4 0.1.0 git:6b11f4e <<>> AAAA docs.rs ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 60549 ;; flags: qr rd ra; QUERY: 1, ANSWER: 8, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION: ;docs.rs. IN AAAA

;; ANSWER SECTION: docs.rs. 59 IN AAAA 2600:9000:21f8:9a00:14:cae8:4080:93a1 docs.rs. 59 IN AAAA 2600:9000:21f8:6a00:14:cae8:4080:93a1 docs.rs. 59 IN AAAA 2600:9000:21f8:2600:14:cae8:4080:93a1 docs.rs. 59 IN AAAA 2600:9000:21f8:7000:14:cae8:4080:93a1 docs.rs. 59 IN AAAA 2600:9000:21f8:3800:14:cae8:4080:93a1 docs.rs. 59 IN AAAA 2600:9000:21f8:2800:14:cae8:4080:93a1 docs.rs. 59 IN AAAA 2600:9000:21f8:8000:14:cae8:4080:93a1 docs.rs. 59 IN AAAA 2600:9000:21f8:d600:14:cae8:4080:93a1

;; Query time: 158.264869ms ;; SERVER: 8.8.8.8:53 ;; WHEN: Fri, 13 Aug 2021 09:01:00 +0300 ;; MSG SIZE rcvd: 249

```

When nameserver is not specified, it is auto-detected from the OS configuration.

```shell $> ch4 crates.io ANY

; <<>> ch4 0.1.0 git:6b11f4e <<>> ANY crates.io ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 8493 ;; flags: qr rd ra; QUERY: 1, ANSWER: 12, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION: ;crates.io. IN ANY

;; ANSWER SECTION: crates.io. 300 IN TXT "v=spf1 include:mailgun.org ~all" crates.io. 300 IN MX 10 mxa.mailgun.org. crates.io. 300 IN MX 10 mxb.mailgun.org. crates.io. 900 IN SOA ns-1064.awsdns-05.org. awsdns-hostmaster.amazon.com. 1 7200 900 1209600 86400 crates.io. 56 IN A 13.225.255.29 crates.io. 56 IN A 13.225.255.54 crates.io. 56 IN A 13.225.255.16 crates.io. 56 IN A 13.225.255.26 crates.io. 60 IN NS ns-217.awsdns-27.com. crates.io. 60 IN NS ns-1543.awsdns-00.co.uk. crates.io. 60 IN NS ns-817.awsdns-38.net. crates.io. 60 IN NS ns-1064.awsdns-05.org.

;; Query time: 228.227499ms ;; SERVER: 127.0.0.53:53 ;; WHEN: Fri, 13 Aug 2021 08:06:40 +0300 ;; MSG SIZE rcvd: 384

```

Options

ch4's options follow the features exposed by rsdns. The detailed list of options is shown via --help flag.

```shell $> ch4 --help

ch4 0.1.0 git:6b11f4e DNS Stub Resolver

USAGE: ch4 [FLAGS] [OPTIONS] [positional]...

FLAGS: -h, --help Prints help information

    --info
        Prints build information

    --rrset
        Uses query_rrset API instead of query_raw

-V, --version
        Prints version information

OPTIONS: -p, --port [default: 53]

-l, --query-lifetime <query-lifetime>
        query lifetime (in msec). [default: 10000]

-t, --query-timeout <query-timeout>
        query timeout (in msec). Use 0 to disable. [default: 2000]

ARGS: ... Positional arguments ...

        Positional arguments may be specified without any particular order.
        Arguments specified later take precedence.
        Arguments that are not recognized as special are treated as names
        to be queried.


        @<nameserver> - specifies the nameserver IP address.
                        If not specified, the first nameserver from OS
                        configuration is used.

        <qtype>       - query type (A, AAAA, NS ...).
                        An argument matching any of the supported query types
                        is considered as query type. Trailing dot can be
                        used to disambiguate a query name (A.).

        +udp          - sets the Udp protocol strategy.
                        UDP is preferred for all queries including ANY.

        +tcp          - sets the Tcp protocol strategy.
                        Only TCP is used for all queries.

        +notcp        - sets NoTcp protocol strategy. Only UDP is used.
                        Truncated queries are returned as is.

        +[no]rec      - enables (disables) recursive query.
                        Queries are recursive by default.

```

Some build information and the list of auto-detected DNS servers are shown via --info flag.

```shell $> ch4 --info

build time: Fri, 13 Aug 2021 05:02:04 +0000 build semver: 0.1.0 git version: n/a git commit hash: 6b11f4e7c0693b241f41f3607fb16fee064ba130 git branch: refs/heads/master compiler: rustc rustc: rustc 1.54.0 (a178d0322 2021-07-26) ci platform: Generic CI cargo features: nettokio, tokio cargo profile: debug cargo target: x8664-pc-windows-msvc endianness: little pointer width: 64 build system name: Windows build os version: Windows Server 2019 Datacenter build cpu vendor: GenuineIntel build cpu brand: Intel(R) Xeon(R) Platinum 8171M CPU @ 2.60GHz dns server #0: 168.63.129.16:53 ```

License

Licensed under either of

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.