refactor to async tokio with modular architecture
- Replace synchronous std::net::UdpSocket with tokio async runtime - Spawn concurrent task per incoming DNS query via tokio::spawn - Extract monolithic main.rs into modules: buffer, header, question, record, packet, config, cache, forward, stats - Share state across tasks via Arc<ServerCtx> with scoped Mutex locks - Add TOML config loading, TTL-aware cache, structured logging, stats - Add CLAUDE.md, README, dns_fun.toml config, and design docs Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
This commit is contained in:
Razvan Dimescu
59
CLAUDE.md
Normal file
59
CLAUDE.md
Normal file
@@ -0,0 +1,59 @@
|
|||||||
|
# CLAUDE.md
|
||||||
|
|
||||||
|
This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
|
||||||
|
|
||||||
|
## Overview
|
||||||
|
|
||||||
|
A DNS forwarding/caching proxy in Rust. Serves local zone records from TOML config, caches upstream responses with TTL-based expiration, forwards unknown queries to an upstream resolver, and logs all queries with structured output.
|
||||||
|
|
||||||
|
## Build & Run
|
||||||
|
|
||||||
|
```bash
|
||||||
|
cargo build # compile
|
||||||
|
sudo cargo run # run with default config (dns_fun.toml)
|
||||||
|
sudo cargo run -- path/to/config # run with custom config path
|
||||||
|
RUST_LOG=debug sudo cargo run # verbose logging
|
||||||
|
```
|
||||||
|
|
||||||
|
Test with: `dig @127.0.0.1 google.com`
|
||||||
|
|
||||||
|
No tests or linter configured.
|
||||||
|
|
||||||
|
## Architecture
|
||||||
|
|
||||||
|
```
|
||||||
|
src/
|
||||||
|
lib.rs # module declarations, Error/Result type aliases
|
||||||
|
main.rs # startup, config load, UDP listen loop, request pipeline
|
||||||
|
buffer.rs # BytePacketBuffer — 512-byte DNS wire format read/write
|
||||||
|
header.rs # DnsHeader, ResultCode — 12-byte header bitfield parsing
|
||||||
|
question.rs # DnsQuestion, QueryType — query section (A, NS, CNAME, MX, AAAA)
|
||||||
|
record.rs # DnsRecord — resource record variants with read/write
|
||||||
|
packet.rs # DnsPacket — top-level: header + questions + answers + authorities + resources
|
||||||
|
config.rs # Config loading from TOML, zone map builder
|
||||||
|
cache.rs # DnsCache — TTL-aware cache with lazy eviction
|
||||||
|
forward.rs # forward_query() — sends query to upstream, build_servfail() — error response
|
||||||
|
stats.rs # ServerStats — query counters and periodic summary
|
||||||
|
```
|
||||||
|
|
||||||
|
## Request Pipeline
|
||||||
|
|
||||||
|
```
|
||||||
|
Query → Parse → Log → Local Zones → Cache → Upstream Forward (+ cache result) → Log → Respond
|
||||||
|
```
|
||||||
|
|
||||||
|
## Config
|
||||||
|
|
||||||
|
`dns_fun.toml` at project root. Sections: `[server]`, `[upstream]`, `[cache]`, `[[zones]]`. Falls back to sensible defaults if file is missing.
|
||||||
|
|
||||||
|
## Logging
|
||||||
|
|
||||||
|
Controlled via `RUST_LOG` env var. Default level: `info` (one structured line per query). `debug` adds response details. Stats summary every 1000 queries.
|
||||||
|
|
||||||
|
## Key Details
|
||||||
|
|
||||||
|
- Rust 2018 edition, deps: `serde`, `toml`, `log`, `env_logger`
|
||||||
|
- DNS packet size limited to 512 bytes (standard UDP DNS)
|
||||||
|
- `BytePacketBuffer::read_qname` handles label compression (pointer jumps)
|
||||||
|
- `type Error = Box<dyn std::error::Error>` / `type Result<T>` aliased in `lib.rs`
|
||||||
|
- Cache: TTL clamped between `min_ttl` and `max_ttl`, lazy eviction every 1000 queries
|
||||||
425
Cargo.lock
generated
Normal file
425
Cargo.lock
generated
Normal file
@@ -0,0 +1,425 @@
|
|||||||
|
# This file is automatically @generated by Cargo.
|
||||||
|
# It is not intended for manual editing.
|
||||||
|
version = 4
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "aho-corasick"
|
||||||
|
version = "1.1.4"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "ddd31a130427c27518df266943a5308ed92d4b226cc639f5a8f1002816174301"
|
||||||
|
dependencies = [
|
||||||
|
"memchr",
|
||||||
|
]
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "anstream"
|
||||||
|
version = "0.6.21"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "43d5b281e737544384e969a5ccad3f1cdd24b48086a0fc1b2a5262a26b8f4f4a"
|
||||||
|
dependencies = [
|
||||||
|
"anstyle",
|
||||||
|
"anstyle-parse",
|
||||||
|
"anstyle-query",
|
||||||
|
"anstyle-wincon",
|
||||||
|
"colorchoice",
|
||||||
|
"is_terminal_polyfill",
|
||||||
|
"utf8parse",
|
||||||
|
]
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "anstyle"
|
||||||
|
version = "1.0.13"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "5192cca8006f1fd4f7237516f40fa183bb07f8fbdfedaa0036de5ea9b0b45e78"
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "anstyle-parse"
|
||||||
|
version = "0.2.7"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "4e7644824f0aa2c7b9384579234ef10eb7efb6a0deb83f9630a49594dd9c15c2"
|
||||||
|
dependencies = [
|
||||||
|
"utf8parse",
|
||||||
|
]
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "anstyle-query"
|
||||||
|
version = "1.1.5"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "40c48f72fd53cd289104fc64099abca73db4166ad86ea0b4341abe65af83dadc"
|
||||||
|
dependencies = [
|
||||||
|
"windows-sys",
|
||||||
|
]
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "anstyle-wincon"
|
||||||
|
version = "3.0.11"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "291e6a250ff86cd4a820112fb8898808a366d8f9f58ce16d1f538353ad55747d"
|
||||||
|
dependencies = [
|
||||||
|
"anstyle",
|
||||||
|
"once_cell_polyfill",
|
||||||
|
"windows-sys",
|
||||||
|
]
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "colorchoice"
|
||||||
|
version = "1.0.4"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "b05b61dc5112cbb17e4b6cd61790d9845d13888356391624cbe7e41efeac1e75"
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "dns_fun"
|
||||||
|
version = "0.1.0"
|
||||||
|
dependencies = [
|
||||||
|
"env_logger",
|
||||||
|
"log",
|
||||||
|
"serde",
|
||||||
|
"tokio",
|
||||||
|
"toml",
|
||||||
|
]
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "env_filter"
|
||||||
|
version = "1.0.0"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "7a1c3cc8e57274ec99de65301228b537f1e4eedc1b8e0f9411c6caac8ae7308f"
|
||||||
|
dependencies = [
|
||||||
|
"log",
|
||||||
|
"regex",
|
||||||
|
]
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "env_logger"
|
||||||
|
version = "0.11.9"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "b2daee4ea451f429a58296525ddf28b45a3b64f1acf6587e2067437bb11e218d"
|
||||||
|
dependencies = [
|
||||||
|
"anstream",
|
||||||
|
"anstyle",
|
||||||
|
"env_filter",
|
||||||
|
"jiff",
|
||||||
|
"log",
|
||||||
|
]
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "equivalent"
|
||||||
|
version = "1.0.2"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "877a4ace8713b0bcf2a4e7eec82529c029f1d0619886d18145fea96c3ffe5c0f"
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "hashbrown"
|
||||||
|
version = "0.16.1"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "841d1cc9bed7f9236f321df977030373f4a4163ae1a7dbfe1a51a2c1a51d9100"
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "indexmap"
|
||||||
|
version = "2.13.0"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "7714e70437a7dc3ac8eb7e6f8df75fd8eb422675fc7678aff7364301092b1017"
|
||||||
|
dependencies = [
|
||||||
|
"equivalent",
|
||||||
|
"hashbrown",
|
||||||
|
]
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "is_terminal_polyfill"
|
||||||
|
version = "1.70.2"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "a6cb138bb79a146c1bd460005623e142ef0181e3d0219cb493e02f7d08a35695"
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "jiff"
|
||||||
|
version = "0.2.23"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "1a3546dc96b6d42c5f24902af9e2538e82e39ad350b0c766eb3fbf2d8f3d8359"
|
||||||
|
dependencies = [
|
||||||
|
"jiff-static",
|
||||||
|
"log",
|
||||||
|
"portable-atomic",
|
||||||
|
"portable-atomic-util",
|
||||||
|
"serde_core",
|
||||||
|
]
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "jiff-static"
|
||||||
|
version = "0.2.23"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "2a8c8b344124222efd714b73bb41f8b5120b27a7cc1c75593a6ff768d9d05aa4"
|
||||||
|
dependencies = [
|
||||||
|
"proc-macro2",
|
||||||
|
"quote",
|
||||||
|
"syn",
|
||||||
|
]
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "libc"
|
||||||
|
version = "0.2.183"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "b5b646652bf6661599e1da8901b3b9522896f01e736bad5f723fe7a3a27f899d"
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "log"
|
||||||
|
version = "0.4.29"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "5e5032e24019045c762d3c0f28f5b6b8bbf38563a65908389bf7978758920897"
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "memchr"
|
||||||
|
version = "2.8.0"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "f8ca58f447f06ed17d5fc4043ce1b10dd205e060fb3ce5b979b8ed8e59ff3f79"
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "mio"
|
||||||
|
version = "1.1.1"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "a69bcab0ad47271a0234d9422b131806bf3968021e5dc9328caf2d4cd58557fc"
|
||||||
|
dependencies = [
|
||||||
|
"libc",
|
||||||
|
"wasi",
|
||||||
|
"windows-sys",
|
||||||
|
]
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "once_cell_polyfill"
|
||||||
|
version = "1.70.2"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "384b8ab6d37215f3c5301a95a4accb5d64aa607f1fcb26a11b5303878451b4fe"
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "pin-project-lite"
|
||||||
|
version = "0.2.17"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "a89322df9ebe1c1578d689c92318e070967d1042b512afbe49518723f4e6d5cd"
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "portable-atomic"
|
||||||
|
version = "1.13.1"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "c33a9471896f1c69cecef8d20cbe2f7accd12527ce60845ff44c153bb2a21b49"
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "portable-atomic-util"
|
||||||
|
version = "0.2.5"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "7a9db96d7fa8782dd8c15ce32ffe8680bbd1e978a43bf51a34d39483540495f5"
|
||||||
|
dependencies = [
|
||||||
|
"portable-atomic",
|
||||||
|
]
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "proc-macro2"
|
||||||
|
version = "1.0.106"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "8fd00f0bb2e90d81d1044c2b32617f68fcb9fa3bb7640c23e9c748e53fb30934"
|
||||||
|
dependencies = [
|
||||||
|
"unicode-ident",
|
||||||
|
]
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "quote"
|
||||||
|
version = "1.0.45"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "41f2619966050689382d2b44f664f4bc593e129785a36d6ee376ddf37259b924"
|
||||||
|
dependencies = [
|
||||||
|
"proc-macro2",
|
||||||
|
]
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "regex"
|
||||||
|
version = "1.12.3"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "e10754a14b9137dd7b1e3e5b0493cc9171fdd105e0ab477f51b72e7f3ac0e276"
|
||||||
|
dependencies = [
|
||||||
|
"aho-corasick",
|
||||||
|
"memchr",
|
||||||
|
"regex-automata",
|
||||||
|
"regex-syntax",
|
||||||
|
]
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "regex-automata"
|
||||||
|
version = "0.4.14"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "6e1dd4122fc1595e8162618945476892eefca7b88c52820e74af6262213cae8f"
|
||||||
|
dependencies = [
|
||||||
|
"aho-corasick",
|
||||||
|
"memchr",
|
||||||
|
"regex-syntax",
|
||||||
|
]
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "regex-syntax"
|
||||||
|
version = "0.8.10"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "dc897dd8d9e8bd1ed8cdad82b5966c3e0ecae09fb1907d58efaa013543185d0a"
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "serde"
|
||||||
|
version = "1.0.228"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "9a8e94ea7f378bd32cbbd37198a4a91436180c5bb472411e48b5ec2e2124ae9e"
|
||||||
|
dependencies = [
|
||||||
|
"serde_core",
|
||||||
|
"serde_derive",
|
||||||
|
]
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "serde_core"
|
||||||
|
version = "1.0.228"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "41d385c7d4ca58e59fc732af25c3983b67ac852c1a25000afe1175de458b67ad"
|
||||||
|
dependencies = [
|
||||||
|
"serde_derive",
|
||||||
|
]
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "serde_derive"
|
||||||
|
version = "1.0.228"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "d540f220d3187173da220f885ab66608367b6574e925011a9353e4badda91d79"
|
||||||
|
dependencies = [
|
||||||
|
"proc-macro2",
|
||||||
|
"quote",
|
||||||
|
"syn",
|
||||||
|
]
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "serde_spanned"
|
||||||
|
version = "0.6.9"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "bf41e0cfaf7226dca15e8197172c295a782857fcb97fad1808a166870dee75a3"
|
||||||
|
dependencies = [
|
||||||
|
"serde",
|
||||||
|
]
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "socket2"
|
||||||
|
version = "0.6.3"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "3a766e1110788c36f4fa1c2b71b387a7815aa65f88ce0229841826633d93723e"
|
||||||
|
dependencies = [
|
||||||
|
"libc",
|
||||||
|
"windows-sys",
|
||||||
|
]
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "syn"
|
||||||
|
version = "2.0.117"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "e665b8803e7b1d2a727f4023456bbbbe74da67099c585258af0ad9c5013b9b99"
|
||||||
|
dependencies = [
|
||||||
|
"proc-macro2",
|
||||||
|
"quote",
|
||||||
|
"unicode-ident",
|
||||||
|
]
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "tokio"
|
||||||
|
version = "1.50.0"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "27ad5e34374e03cfffefc301becb44e9dc3c17584f414349ebe29ed26661822d"
|
||||||
|
dependencies = [
|
||||||
|
"libc",
|
||||||
|
"mio",
|
||||||
|
"pin-project-lite",
|
||||||
|
"socket2",
|
||||||
|
"tokio-macros",
|
||||||
|
"windows-sys",
|
||||||
|
]
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "tokio-macros"
|
||||||
|
version = "2.6.1"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "5c55a2eff8b69ce66c84f85e1da1c233edc36ceb85a2058d11b0d6a3c7e7569c"
|
||||||
|
dependencies = [
|
||||||
|
"proc-macro2",
|
||||||
|
"quote",
|
||||||
|
"syn",
|
||||||
|
]
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "toml"
|
||||||
|
version = "0.8.23"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "dc1beb996b9d83529a9e75c17a1686767d148d70663143c7854d8b4a09ced362"
|
||||||
|
dependencies = [
|
||||||
|
"serde",
|
||||||
|
"serde_spanned",
|
||||||
|
"toml_datetime",
|
||||||
|
"toml_edit",
|
||||||
|
]
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "toml_datetime"
|
||||||
|
version = "0.6.11"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "22cddaf88f4fbc13c51aebbf5f8eceb5c7c5a9da2ac40a13519eb5b0a0e8f11c"
|
||||||
|
dependencies = [
|
||||||
|
"serde",
|
||||||
|
]
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "toml_edit"
|
||||||
|
version = "0.22.27"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "41fe8c660ae4257887cf66394862d21dbca4a6ddd26f04a3560410406a2f819a"
|
||||||
|
dependencies = [
|
||||||
|
"indexmap",
|
||||||
|
"serde",
|
||||||
|
"serde_spanned",
|
||||||
|
"toml_datetime",
|
||||||
|
"toml_write",
|
||||||
|
"winnow",
|
||||||
|
]
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "toml_write"
|
||||||
|
version = "0.1.2"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "5d99f8c9a7727884afe522e9bd5edbfc91a3312b36a77b5fb8926e4c31a41801"
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "unicode-ident"
|
||||||
|
version = "1.0.24"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "e6e4313cd5fcd3dad5cafa179702e2b244f760991f45397d14d4ebf38247da75"
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "utf8parse"
|
||||||
|
version = "0.2.2"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "06abde3611657adf66d383f00b093d7faecc7fa57071cce2578660c9f1010821"
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "wasi"
|
||||||
|
version = "0.11.1+wasi-snapshot-preview1"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "ccf3ec651a847eb01de73ccad15eb7d99f80485de043efb2f370cd654f4ea44b"
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "windows-link"
|
||||||
|
version = "0.2.1"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "f0805222e57f7521d6a62e36fa9163bc891acd422f971defe97d64e70d0a4fe5"
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "windows-sys"
|
||||||
|
version = "0.61.2"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "ae137229bcbd6cdf0f7b80a31df61766145077ddf49416a728b02cb3921ff3fc"
|
||||||
|
dependencies = [
|
||||||
|
"windows-link",
|
||||||
|
]
|
||||||
|
|
||||||
|
[[package]]
|
||||||
|
name = "winnow"
|
||||||
|
version = "0.7.15"
|
||||||
|
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||||
|
checksum = "df79d97927682d2fd8adb29682d1140b343be4ac0f08fd68b7765d9c059d3945"
|
||||||
|
dependencies = [
|
||||||
|
"memchr",
|
||||||
|
]
|
||||||
@@ -7,3 +7,8 @@ edition = "2018"
|
|||||||
# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
|
# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
|
||||||
|
|
||||||
[dependencies]
|
[dependencies]
|
||||||
|
tokio = { version = "1", features = ["rt-multi-thread", "macros", "net", "time"] }
|
||||||
|
toml = "0.8"
|
||||||
|
serde = { version = "1", features = ["derive"] }
|
||||||
|
log = "0.4"
|
||||||
|
env_logger = "0.11"
|
||||||
|
|||||||
121
README.md
121
README.md
@@ -1 +1,122 @@
|
|||||||
# dns_fun
|
# dns_fun
|
||||||
|
|
||||||
|
A DNS forwarding/caching proxy written from scratch in Rust. Parses and serializes DNS wire protocol (RFC 1035), serves local zone records from TOML config, caches upstream responses with TTL-aware expiration, and logs every query with structured output.
|
||||||
|
|
||||||
|
No async runtime, no DNS libraries — just `std::net::UdpSocket` and manual packet parsing.
|
||||||
|
|
||||||
|
## Record Types
|
||||||
|
|
||||||
|
A, NS, CNAME, MX, AAAA
|
||||||
|
|
||||||
|
## Usage
|
||||||
|
|
||||||
|
```bash
|
||||||
|
# Run with default config (dns_fun.toml)
|
||||||
|
sudo cargo run
|
||||||
|
|
||||||
|
# Run with custom config path
|
||||||
|
sudo cargo run -- path/to/config.toml
|
||||||
|
|
||||||
|
# Test
|
||||||
|
dig @127.0.0.1 google.com
|
||||||
|
dig @127.0.0.1 mysite.local
|
||||||
|
```
|
||||||
|
|
||||||
|
Requires root/sudo for binding to port 53.
|
||||||
|
|
||||||
|
## Configuration
|
||||||
|
|
||||||
|
Edit `dns_fun.toml`:
|
||||||
|
|
||||||
|
```toml
|
||||||
|
[server]
|
||||||
|
bind_addr = "0.0.0.0:53"
|
||||||
|
|
||||||
|
[upstream]
|
||||||
|
address = "8.8.8.8"
|
||||||
|
port = 53
|
||||||
|
timeout_ms = 3000
|
||||||
|
|
||||||
|
[cache]
|
||||||
|
max_entries = 10000
|
||||||
|
min_ttl = 60 # floor: cache at least 60s
|
||||||
|
max_ttl = 86400 # ceiling: never cache longer than 24h
|
||||||
|
|
||||||
|
[[zones]]
|
||||||
|
domain = "mysite.local"
|
||||||
|
record_type = "A"
|
||||||
|
value = "127.0.0.1"
|
||||||
|
ttl = 60
|
||||||
|
|
||||||
|
[[zones]]
|
||||||
|
domain = "other.local"
|
||||||
|
record_type = "AAAA"
|
||||||
|
value = "::1"
|
||||||
|
ttl = 120
|
||||||
|
```
|
||||||
|
|
||||||
|
All sections are optional — sensible defaults are used if the config file is missing.
|
||||||
|
|
||||||
|
## Request Pipeline
|
||||||
|
|
||||||
|
```
|
||||||
|
Query -> Parse -> Local Zones -> Cache -> Upstream Forward -> Respond
|
||||||
|
```
|
||||||
|
|
||||||
|
1. **Local zones** — match against records defined in `[[zones]]`, respond immediately
|
||||||
|
2. **Cache** — return TTL-adjusted cached response if available
|
||||||
|
3. **Forward** — send query to upstream resolver, cache the response
|
||||||
|
4. **SERVFAIL** — returned to client on upstream failure
|
||||||
|
|
||||||
|
## Caching
|
||||||
|
|
||||||
|
- TTL derived from minimum TTL across answer records
|
||||||
|
- Clamped to configured `min_ttl`/`max_ttl` bounds
|
||||||
|
- TTLs in cached responses decrease over time (adjusted on serve)
|
||||||
|
- Lazy eviction on capacity overflow + periodic sweep every 1000 queries
|
||||||
|
|
||||||
|
## Logging
|
||||||
|
|
||||||
|
Controlled via `RUST_LOG` environment variable:
|
||||||
|
|
||||||
|
```bash
|
||||||
|
RUST_LOG=info sudo cargo run # default — one line per query
|
||||||
|
RUST_LOG=debug sudo cargo run # includes response details
|
||||||
|
RUST_LOG=warn sudo cargo run # errors only
|
||||||
|
```
|
||||||
|
|
||||||
|
Log output:
|
||||||
|
|
||||||
|
```
|
||||||
|
2026-03-10T14:23:01.123Z INFO 192.168.1.5:41234 | A google.com | FORWARD | NOERROR | 12ms
|
||||||
|
2026-03-10T14:23:01.456Z INFO 192.168.1.5:41235 | A mysite.local | LOCAL | NOERROR | 0ms
|
||||||
|
2026-03-10T14:23:02.789Z INFO 192.168.1.5:41236 | A google.com | CACHED | NOERROR | 0ms
|
||||||
|
```
|
||||||
|
|
||||||
|
Stats summary (total, forwarded, cached, local, blocked, errors) logged every 1000 queries.
|
||||||
|
|
||||||
|
## Project Structure
|
||||||
|
|
||||||
|
```
|
||||||
|
src/
|
||||||
|
main.rs # startup, config load, UDP listen loop, request pipeline
|
||||||
|
lib.rs # module declarations, Error/Result type aliases
|
||||||
|
buffer.rs # BytePacketBuffer — 512-byte DNS wire format read/write
|
||||||
|
header.rs # DnsHeader, ResultCode
|
||||||
|
question.rs # DnsQuestion, QueryType
|
||||||
|
record.rs # DnsRecord (A, NS, CNAME, MX, AAAA, UNKNOWN)
|
||||||
|
packet.rs # DnsPacket — full DNS message parse/serialize
|
||||||
|
config.rs # TOML config loading, zone map builder
|
||||||
|
cache.rs # TTL-aware DNS response cache with lazy eviction
|
||||||
|
forward.rs # upstream forwarding, SERVFAIL builder
|
||||||
|
stats.rs # query counters and periodic summary
|
||||||
|
```
|
||||||
|
|
||||||
|
## Dependencies
|
||||||
|
|
||||||
|
```toml
|
||||||
|
toml = "0.8"
|
||||||
|
serde = { version = "1", features = ["derive"] }
|
||||||
|
log = "0.4"
|
||||||
|
env_logger = "0.11"
|
||||||
|
```
|
||||||
|
|||||||
25
dns_fun.toml
Normal file
25
dns_fun.toml
Normal file
@@ -0,0 +1,25 @@
|
|||||||
|
[server]
|
||||||
|
bind_addr = "0.0.0.0:53"
|
||||||
|
|
||||||
|
[upstream]
|
||||||
|
address = "8.8.8.8"
|
||||||
|
port = 53
|
||||||
|
timeout_ms = 3000
|
||||||
|
|
||||||
|
[cache]
|
||||||
|
max_entries = 10000
|
||||||
|
min_ttl = 60
|
||||||
|
max_ttl = 86400
|
||||||
|
|
||||||
|
# Example zone records:
|
||||||
|
# [[zones]]
|
||||||
|
# domain = "dimescu.ro"
|
||||||
|
# record_type = "A"
|
||||||
|
# value = "3.120.139.105"
|
||||||
|
# ttl = 30
|
||||||
|
|
||||||
|
# [[zones]]
|
||||||
|
# domain = "test.local"
|
||||||
|
# record_type = "A"
|
||||||
|
# value = "127.0.0.1"
|
||||||
|
# ttl = 60
|
||||||
181
src/buffer.rs
Normal file
181
src/buffer.rs
Normal file
@@ -0,0 +1,181 @@
|
|||||||
|
use crate::{Result};
|
||||||
|
|
||||||
|
pub struct BytePacketBuffer {
|
||||||
|
pub buf: [u8; 512],
|
||||||
|
pub pos: usize,
|
||||||
|
}
|
||||||
|
|
||||||
|
impl BytePacketBuffer {
|
||||||
|
pub fn new() -> BytePacketBuffer {
|
||||||
|
BytePacketBuffer {
|
||||||
|
buf: [0; 512],
|
||||||
|
pos: 0,
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn pos(&self) -> usize {
|
||||||
|
self.pos
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn filled(&self) -> &[u8] {
|
||||||
|
&self.buf[..self.pos]
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn step(&mut self, steps: usize) -> Result<()> {
|
||||||
|
self.pos += steps;
|
||||||
|
Ok(())
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn seek(&mut self, pos: usize) -> Result<()> {
|
||||||
|
self.pos = pos;
|
||||||
|
Ok(())
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn read(&mut self) -> Result<u8> {
|
||||||
|
if self.pos >= 512 {
|
||||||
|
return Err("End of buffer".into());
|
||||||
|
}
|
||||||
|
let res = self.buf[self.pos];
|
||||||
|
self.pos += 1;
|
||||||
|
Ok(res)
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn get(&self, pos: usize) -> Result<u8> {
|
||||||
|
if pos >= 512 {
|
||||||
|
return Err("End of buffer".into());
|
||||||
|
}
|
||||||
|
Ok(self.buf[pos])
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn get_range(&self, start: usize, len: usize) -> Result<&[u8]> {
|
||||||
|
if start + len > 512 {
|
||||||
|
return Err("End of buffer".into());
|
||||||
|
}
|
||||||
|
Ok(&self.buf[start..start + len])
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn read_u16(&mut self) -> Result<u16> {
|
||||||
|
let res = ((self.read()? as u16) << 8) | (self.read()? as u16);
|
||||||
|
Ok(res)
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn read_u32(&mut self) -> Result<u32> {
|
||||||
|
let res = ((self.read()? as u32) << 24)
|
||||||
|
| ((self.read()? as u32) << 16)
|
||||||
|
| ((self.read()? as u32) << 8)
|
||||||
|
| ((self.read()? as u32) << 0);
|
||||||
|
Ok(res)
|
||||||
|
}
|
||||||
|
|
||||||
|
/// Read a qname, handling label compression (pointer jumps).
|
||||||
|
/// Converts wire format like [3]www[6]google[3]com[0] into "www.google.com".
|
||||||
|
pub fn read_qname(&mut self, outstr: &mut String) -> Result<()> {
|
||||||
|
let mut pos = self.pos();
|
||||||
|
let mut jumped = false;
|
||||||
|
let max_jumps = 5;
|
||||||
|
let mut jumps_performed = 0;
|
||||||
|
let mut delim = "";
|
||||||
|
|
||||||
|
loop {
|
||||||
|
if jumps_performed > max_jumps {
|
||||||
|
return Err(format!("Limit of {} jumps exceeded", max_jumps).into());
|
||||||
|
}
|
||||||
|
|
||||||
|
let len = self.get(pos)?;
|
||||||
|
|
||||||
|
if (len & 0xC0) == 0xC0 {
|
||||||
|
if !jumped {
|
||||||
|
self.seek(pos + 2)?;
|
||||||
|
}
|
||||||
|
|
||||||
|
let b2 = self.get(pos + 1)? as u16;
|
||||||
|
let offset = (((len as u16) ^ 0xC0) << 8) | b2;
|
||||||
|
pos = offset as usize;
|
||||||
|
|
||||||
|
jumped = true;
|
||||||
|
jumps_performed += 1;
|
||||||
|
continue;
|
||||||
|
} else {
|
||||||
|
pos += 1;
|
||||||
|
|
||||||
|
if len == 0 {
|
||||||
|
break;
|
||||||
|
}
|
||||||
|
|
||||||
|
outstr.push_str(delim);
|
||||||
|
|
||||||
|
let str_buffer = self.get_range(pos, len as usize)?;
|
||||||
|
for &b in str_buffer {
|
||||||
|
outstr.push(b.to_ascii_lowercase() as char);
|
||||||
|
}
|
||||||
|
|
||||||
|
delim = ".";
|
||||||
|
pos += len as usize;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
if !jumped {
|
||||||
|
self.seek(pos)?;
|
||||||
|
}
|
||||||
|
|
||||||
|
Ok(())
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn write(&mut self, val: u8) -> Result<()> {
|
||||||
|
if self.pos >= 512 {
|
||||||
|
return Err("End of buffer".into());
|
||||||
|
}
|
||||||
|
self.buf[self.pos] = val;
|
||||||
|
self.pos += 1;
|
||||||
|
Ok(())
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn write_u8(&mut self, val: u8) -> Result<()> {
|
||||||
|
self.write(val)
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn write_u16(&mut self, val: u16) -> Result<()> {
|
||||||
|
self.write((val >> 8) as u8)?;
|
||||||
|
self.write((val & 0xFF) as u8)?;
|
||||||
|
Ok(())
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn write_u32(&mut self, val: u32) -> Result<()> {
|
||||||
|
self.write(((val >> 24) & 0xFF) as u8)?;
|
||||||
|
self.write(((val >> 16) & 0xFF) as u8)?;
|
||||||
|
self.write(((val >> 8) & 0xFF) as u8)?;
|
||||||
|
self.write(((val >> 0) & 0xFF) as u8)?;
|
||||||
|
Ok(())
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn write_qname(&mut self, qname: &str) -> Result<()> {
|
||||||
|
for label in qname.split('.') {
|
||||||
|
let len = label.len();
|
||||||
|
if len > 0x3f {
|
||||||
|
return Err("Single label exceeds 63 characters of length".into());
|
||||||
|
}
|
||||||
|
|
||||||
|
self.write_u8(len as u8)?;
|
||||||
|
for b in label.as_bytes() {
|
||||||
|
self.write_u8(*b)?;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
self.write_u8(0)?;
|
||||||
|
Ok(())
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn set(&mut self, pos: usize, val: u8) -> Result<()> {
|
||||||
|
if pos >= 512 {
|
||||||
|
return Err("End of buffer".into());
|
||||||
|
}
|
||||||
|
self.buf[pos] = val;
|
||||||
|
Ok(())
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn set_u16(&mut self, pos: usize, val: u16) -> Result<()> {
|
||||||
|
self.set(pos, (val >> 8) as u8)?;
|
||||||
|
self.set(pos + 1, (val & 0xFF) as u8)?;
|
||||||
|
Ok(())
|
||||||
|
}
|
||||||
|
}
|
||||||
95
src/cache.rs
Normal file
95
src/cache.rs
Normal file
@@ -0,0 +1,95 @@
|
|||||||
|
use std::collections::HashMap;
|
||||||
|
use std::time::{Duration, Instant};
|
||||||
|
|
||||||
|
use crate::packet::DnsPacket;
|
||||||
|
use crate::question::QueryType;
|
||||||
|
use crate::record::DnsRecord;
|
||||||
|
|
||||||
|
struct CacheEntry {
|
||||||
|
packet: DnsPacket,
|
||||||
|
inserted_at: Instant,
|
||||||
|
ttl: Duration,
|
||||||
|
}
|
||||||
|
|
||||||
|
pub struct DnsCache {
|
||||||
|
entries: HashMap<(String, QueryType), CacheEntry>,
|
||||||
|
max_entries: usize,
|
||||||
|
min_ttl: u32,
|
||||||
|
max_ttl: u32,
|
||||||
|
query_count: u64,
|
||||||
|
}
|
||||||
|
|
||||||
|
impl DnsCache {
|
||||||
|
pub fn new(max_entries: usize, min_ttl: u32, max_ttl: u32) -> Self {
|
||||||
|
DnsCache {
|
||||||
|
entries: HashMap::new(),
|
||||||
|
max_entries,
|
||||||
|
min_ttl,
|
||||||
|
max_ttl,
|
||||||
|
query_count: 0,
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn lookup(&mut self, domain: &str, qtype: QueryType) -> Option<DnsPacket> {
|
||||||
|
self.query_count += 1;
|
||||||
|
|
||||||
|
// Periodic eviction every 1000 queries
|
||||||
|
if self.query_count % 1000 == 0 {
|
||||||
|
self.evict_expired();
|
||||||
|
}
|
||||||
|
|
||||||
|
let key = (domain.to_string(), qtype);
|
||||||
|
let entry = self.entries.get(&key)?;
|
||||||
|
|
||||||
|
let elapsed = entry.inserted_at.elapsed();
|
||||||
|
if elapsed >= entry.ttl {
|
||||||
|
self.entries.remove(&key);
|
||||||
|
return None;
|
||||||
|
}
|
||||||
|
|
||||||
|
let remaining_secs = (entry.ttl - elapsed).as_secs() as u32;
|
||||||
|
let remaining = remaining_secs.max(1);
|
||||||
|
|
||||||
|
let mut packet = entry.packet.clone();
|
||||||
|
adjust_ttls(&mut packet.answers, remaining);
|
||||||
|
adjust_ttls(&mut packet.authorities, remaining);
|
||||||
|
adjust_ttls(&mut packet.resources, remaining);
|
||||||
|
|
||||||
|
Some(packet)
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn insert(&mut self, domain: &str, qtype: QueryType, packet: &DnsPacket) {
|
||||||
|
if self.entries.len() >= self.max_entries {
|
||||||
|
self.evict_expired();
|
||||||
|
// If still full after eviction, skip insertion
|
||||||
|
if self.entries.len() >= self.max_entries {
|
||||||
|
return;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
let min_ttl = extract_min_ttl(&packet.answers)
|
||||||
|
.unwrap_or(self.min_ttl)
|
||||||
|
.clamp(self.min_ttl, self.max_ttl);
|
||||||
|
|
||||||
|
let key = (domain.to_string(), qtype);
|
||||||
|
self.entries.insert(key, CacheEntry {
|
||||||
|
packet: packet.clone(),
|
||||||
|
inserted_at: Instant::now(),
|
||||||
|
ttl: Duration::from_secs(min_ttl as u64),
|
||||||
|
});
|
||||||
|
}
|
||||||
|
|
||||||
|
fn evict_expired(&mut self) {
|
||||||
|
self.entries.retain(|_, entry| entry.inserted_at.elapsed() < entry.ttl);
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
fn extract_min_ttl(records: &[DnsRecord]) -> Option<u32> {
|
||||||
|
records.iter().map(|r| r.ttl()).min()
|
||||||
|
}
|
||||||
|
|
||||||
|
fn adjust_ttls(records: &mut [DnsRecord], new_ttl: u32) {
|
||||||
|
for record in records.iter_mut() {
|
||||||
|
record.set_ttl(new_ttl);
|
||||||
|
}
|
||||||
|
}
|
||||||
169
src/config.rs
Normal file
169
src/config.rs
Normal file
@@ -0,0 +1,169 @@
|
|||||||
|
use std::collections::HashMap;
|
||||||
|
use std::net::Ipv4Addr;
|
||||||
|
use std::net::Ipv6Addr;
|
||||||
|
use std::path::Path;
|
||||||
|
|
||||||
|
use serde::Deserialize;
|
||||||
|
|
||||||
|
use crate::question::QueryType;
|
||||||
|
use crate::record::DnsRecord;
|
||||||
|
use crate::Result;
|
||||||
|
|
||||||
|
#[derive(Deserialize)]
|
||||||
|
pub struct Config {
|
||||||
|
#[serde(default)]
|
||||||
|
pub server: ServerConfig,
|
||||||
|
#[serde(default)]
|
||||||
|
pub upstream: UpstreamConfig,
|
||||||
|
#[serde(default)]
|
||||||
|
pub cache: CacheConfig,
|
||||||
|
#[serde(default)]
|
||||||
|
pub zones: Vec<ZoneRecord>,
|
||||||
|
}
|
||||||
|
|
||||||
|
#[derive(Deserialize)]
|
||||||
|
pub struct ServerConfig {
|
||||||
|
#[serde(default = "default_bind_addr")]
|
||||||
|
pub bind_addr: String,
|
||||||
|
}
|
||||||
|
|
||||||
|
impl Default for ServerConfig {
|
||||||
|
fn default() -> Self {
|
||||||
|
ServerConfig {
|
||||||
|
bind_addr: default_bind_addr(),
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
fn default_bind_addr() -> String {
|
||||||
|
"0.0.0.0:53".to_string()
|
||||||
|
}
|
||||||
|
|
||||||
|
#[derive(Deserialize)]
|
||||||
|
pub struct UpstreamConfig {
|
||||||
|
#[serde(default = "default_upstream_addr")]
|
||||||
|
pub address: String,
|
||||||
|
#[serde(default = "default_upstream_port")]
|
||||||
|
pub port: u16,
|
||||||
|
#[serde(default = "default_timeout_ms")]
|
||||||
|
pub timeout_ms: u64,
|
||||||
|
}
|
||||||
|
|
||||||
|
impl Default for UpstreamConfig {
|
||||||
|
fn default() -> Self {
|
||||||
|
UpstreamConfig {
|
||||||
|
address: default_upstream_addr(),
|
||||||
|
port: default_upstream_port(),
|
||||||
|
timeout_ms: default_timeout_ms(),
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
fn default_upstream_addr() -> String {
|
||||||
|
"8.8.8.8".to_string()
|
||||||
|
}
|
||||||
|
fn default_upstream_port() -> u16 {
|
||||||
|
53
|
||||||
|
}
|
||||||
|
fn default_timeout_ms() -> u64 {
|
||||||
|
3000
|
||||||
|
}
|
||||||
|
|
||||||
|
#[derive(Deserialize)]
|
||||||
|
pub struct CacheConfig {
|
||||||
|
#[serde(default = "default_max_entries")]
|
||||||
|
pub max_entries: usize,
|
||||||
|
#[serde(default = "default_min_ttl")]
|
||||||
|
pub min_ttl: u32,
|
||||||
|
#[serde(default = "default_max_ttl")]
|
||||||
|
pub max_ttl: u32,
|
||||||
|
}
|
||||||
|
|
||||||
|
impl Default for CacheConfig {
|
||||||
|
fn default() -> Self {
|
||||||
|
CacheConfig {
|
||||||
|
max_entries: default_max_entries(),
|
||||||
|
min_ttl: default_min_ttl(),
|
||||||
|
max_ttl: default_max_ttl(),
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
fn default_max_entries() -> usize {
|
||||||
|
10000
|
||||||
|
}
|
||||||
|
fn default_min_ttl() -> u32 {
|
||||||
|
60
|
||||||
|
}
|
||||||
|
fn default_max_ttl() -> u32 {
|
||||||
|
86400
|
||||||
|
}
|
||||||
|
|
||||||
|
#[derive(Deserialize)]
|
||||||
|
pub struct ZoneRecord {
|
||||||
|
pub domain: String,
|
||||||
|
pub record_type: String,
|
||||||
|
pub value: String,
|
||||||
|
#[serde(default = "default_zone_ttl")]
|
||||||
|
pub ttl: u32,
|
||||||
|
}
|
||||||
|
|
||||||
|
fn default_zone_ttl() -> u32 {
|
||||||
|
300
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn load_config(path: &str) -> Result<Config> {
|
||||||
|
if !Path::new(path).exists() {
|
||||||
|
return Ok(Config {
|
||||||
|
server: ServerConfig::default(),
|
||||||
|
upstream: UpstreamConfig::default(),
|
||||||
|
cache: CacheConfig::default(),
|
||||||
|
zones: Vec::new(),
|
||||||
|
});
|
||||||
|
}
|
||||||
|
let contents = std::fs::read_to_string(path)?;
|
||||||
|
let config: Config = toml::from_str(&contents)?;
|
||||||
|
Ok(config)
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn build_zone_map(zones: &[ZoneRecord]) -> Result<HashMap<(String, QueryType), Vec<DnsRecord>>> {
|
||||||
|
let mut map: HashMap<(String, QueryType), Vec<DnsRecord>> = HashMap::new();
|
||||||
|
|
||||||
|
for zone in zones {
|
||||||
|
let domain = zone.domain.to_lowercase();
|
||||||
|
let (qtype, record) = match zone.record_type.to_uppercase().as_str() {
|
||||||
|
"A" => {
|
||||||
|
let addr: Ipv4Addr = zone.value.parse()
|
||||||
|
.map_err(|e| format!("invalid A record value '{}': {}", zone.value, e))?;
|
||||||
|
(QueryType::A, DnsRecord::A { domain: domain.clone(), addr, ttl: zone.ttl })
|
||||||
|
}
|
||||||
|
"AAAA" => {
|
||||||
|
let addr: Ipv6Addr = zone.value.parse()
|
||||||
|
.map_err(|e| format!("invalid AAAA record value '{}': {}", zone.value, e))?;
|
||||||
|
(QueryType::AAAA, DnsRecord::AAAA { domain: domain.clone(), addr, ttl: zone.ttl })
|
||||||
|
}
|
||||||
|
"CNAME" => {
|
||||||
|
(QueryType::CNAME, DnsRecord::CNAME { domain: domain.clone(), host: zone.value.clone(), ttl: zone.ttl })
|
||||||
|
}
|
||||||
|
"NS" => {
|
||||||
|
(QueryType::NS, DnsRecord::NS { domain: domain.clone(), host: zone.value.clone(), ttl: zone.ttl })
|
||||||
|
}
|
||||||
|
"MX" => {
|
||||||
|
let parts: Vec<&str> = zone.value.splitn(2, ' ').collect();
|
||||||
|
if parts.len() != 2 {
|
||||||
|
return Err(format!("MX value must be 'priority host', got '{}'", zone.value).into());
|
||||||
|
}
|
||||||
|
let priority: u16 = parts[0].parse()
|
||||||
|
.map_err(|e| format!("invalid MX priority '{}': {}", parts[0], e))?;
|
||||||
|
(QueryType::MX, DnsRecord::MX { domain: domain.clone(), priority, host: parts[1].to_string(), ttl: zone.ttl })
|
||||||
|
}
|
||||||
|
other => {
|
||||||
|
return Err(format!("unsupported record type '{}'", other).into());
|
||||||
|
}
|
||||||
|
};
|
||||||
|
|
||||||
|
map.entry((domain, qtype)).or_default().push(record);
|
||||||
|
}
|
||||||
|
|
||||||
|
Ok(map)
|
||||||
|
}
|
||||||
27
src/forward.rs
Normal file
27
src/forward.rs
Normal file
@@ -0,0 +1,27 @@
|
|||||||
|
use std::net::SocketAddr;
|
||||||
|
use std::time::Duration;
|
||||||
|
|
||||||
|
use tokio::net::UdpSocket;
|
||||||
|
use tokio::time::timeout;
|
||||||
|
|
||||||
|
use crate::buffer::BytePacketBuffer;
|
||||||
|
use crate::packet::DnsPacket;
|
||||||
|
use crate::Result;
|
||||||
|
|
||||||
|
pub async fn forward_query(
|
||||||
|
query: &DnsPacket,
|
||||||
|
upstream: SocketAddr,
|
||||||
|
timeout_duration: Duration,
|
||||||
|
) -> Result<DnsPacket> {
|
||||||
|
let socket = UdpSocket::bind("0.0.0.0:0").await?;
|
||||||
|
|
||||||
|
let mut send_buffer = BytePacketBuffer::new();
|
||||||
|
query.write(&mut send_buffer)?;
|
||||||
|
|
||||||
|
socket.send_to(send_buffer.filled(), upstream).await?;
|
||||||
|
|
||||||
|
let mut recv_buffer = BytePacketBuffer::new();
|
||||||
|
timeout(timeout_duration, socket.recv_from(&mut recv_buffer.buf)).await??;
|
||||||
|
|
||||||
|
DnsPacket::from_buffer(&mut recv_buffer)
|
||||||
|
}
|
||||||
133
src/header.rs
Normal file
133
src/header.rs
Normal file
@@ -0,0 +1,133 @@
|
|||||||
|
use crate::buffer::BytePacketBuffer;
|
||||||
|
use crate::Result;
|
||||||
|
|
||||||
|
#[derive(Copy, Clone, Debug, PartialEq, Eq)]
|
||||||
|
pub enum ResultCode {
|
||||||
|
NOERROR = 0,
|
||||||
|
FORMERR = 1,
|
||||||
|
SERVFAIL = 2,
|
||||||
|
NXDOMAIN = 3,
|
||||||
|
NOTIMP = 4,
|
||||||
|
REFUSED = 5,
|
||||||
|
}
|
||||||
|
|
||||||
|
impl ResultCode {
|
||||||
|
pub fn from_num(num: u8) -> ResultCode {
|
||||||
|
match num {
|
||||||
|
1 => ResultCode::FORMERR,
|
||||||
|
2 => ResultCode::SERVFAIL,
|
||||||
|
3 => ResultCode::NXDOMAIN,
|
||||||
|
4 => ResultCode::NOTIMP,
|
||||||
|
5 => ResultCode::REFUSED,
|
||||||
|
0 | _ => ResultCode::NOERROR,
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn as_str(&self) -> &'static str {
|
||||||
|
match self {
|
||||||
|
ResultCode::NOERROR => "NOERROR",
|
||||||
|
ResultCode::FORMERR => "FORMERR",
|
||||||
|
ResultCode::SERVFAIL => "SERVFAIL",
|
||||||
|
ResultCode::NXDOMAIN => "NXDOMAIN",
|
||||||
|
ResultCode::NOTIMP => "NOTIMP",
|
||||||
|
ResultCode::REFUSED => "REFUSED",
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
#[derive(Clone, Debug)]
|
||||||
|
pub struct DnsHeader {
|
||||||
|
pub id: u16,
|
||||||
|
|
||||||
|
pub recursion_desired: bool,
|
||||||
|
pub truncated_message: bool,
|
||||||
|
pub authoritative_answer: bool,
|
||||||
|
pub opcode: u8,
|
||||||
|
pub response: bool,
|
||||||
|
|
||||||
|
pub rescode: ResultCode,
|
||||||
|
pub checking_disabled: bool,
|
||||||
|
pub authed_data: bool,
|
||||||
|
pub z: bool,
|
||||||
|
pub recursion_available: bool,
|
||||||
|
|
||||||
|
pub questions: u16,
|
||||||
|
pub answers: u16,
|
||||||
|
pub authoritative_entries: u16,
|
||||||
|
pub resource_entries: u16,
|
||||||
|
}
|
||||||
|
|
||||||
|
impl DnsHeader {
|
||||||
|
pub fn new() -> DnsHeader {
|
||||||
|
DnsHeader {
|
||||||
|
id: 0,
|
||||||
|
recursion_desired: false,
|
||||||
|
truncated_message: false,
|
||||||
|
authoritative_answer: false,
|
||||||
|
opcode: 0,
|
||||||
|
response: false,
|
||||||
|
rescode: ResultCode::NOERROR,
|
||||||
|
checking_disabled: false,
|
||||||
|
authed_data: false,
|
||||||
|
z: false,
|
||||||
|
recursion_available: false,
|
||||||
|
questions: 0,
|
||||||
|
answers: 0,
|
||||||
|
authoritative_entries: 0,
|
||||||
|
resource_entries: 0,
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn read(&mut self, buffer: &mut BytePacketBuffer) -> Result<()> {
|
||||||
|
self.id = buffer.read_u16()?;
|
||||||
|
|
||||||
|
let flags = buffer.read_u16()?;
|
||||||
|
let a = (flags >> 8) as u8;
|
||||||
|
let b = (flags & 0xFF) as u8;
|
||||||
|
self.recursion_desired = (a & (1 << 0)) > 0;
|
||||||
|
self.truncated_message = (a & (1 << 1)) > 0;
|
||||||
|
self.authoritative_answer = (a & (1 << 2)) > 0;
|
||||||
|
self.opcode = (a >> 3) & 0x0F;
|
||||||
|
self.response = (a & (1 << 7)) > 0;
|
||||||
|
|
||||||
|
self.rescode = ResultCode::from_num(b & 0x0F);
|
||||||
|
self.checking_disabled = (b & (1 << 4)) > 0;
|
||||||
|
self.authed_data = (b & (1 << 5)) > 0;
|
||||||
|
self.z = (b & (1 << 6)) > 0;
|
||||||
|
self.recursion_available = (b & (1 << 7)) > 0;
|
||||||
|
|
||||||
|
self.questions = buffer.read_u16()?;
|
||||||
|
self.answers = buffer.read_u16()?;
|
||||||
|
self.authoritative_entries = buffer.read_u16()?;
|
||||||
|
self.resource_entries = buffer.read_u16()?;
|
||||||
|
|
||||||
|
Ok(())
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn write(&self, buffer: &mut BytePacketBuffer) -> Result<()> {
|
||||||
|
buffer.write_u16(self.id)?;
|
||||||
|
|
||||||
|
buffer.write_u8(
|
||||||
|
(self.recursion_desired as u8)
|
||||||
|
| ((self.truncated_message as u8) << 1)
|
||||||
|
| ((self.authoritative_answer as u8) << 2)
|
||||||
|
| (self.opcode << 3)
|
||||||
|
| ((self.response as u8) << 7) as u8,
|
||||||
|
)?;
|
||||||
|
|
||||||
|
buffer.write_u8(
|
||||||
|
(self.rescode as u8)
|
||||||
|
| ((self.checking_disabled as u8) << 4)
|
||||||
|
| ((self.authed_data as u8) << 5)
|
||||||
|
| ((self.z as u8) << 6)
|
||||||
|
| ((self.recursion_available as u8) << 7),
|
||||||
|
)?;
|
||||||
|
|
||||||
|
buffer.write_u16(self.questions)?;
|
||||||
|
buffer.write_u16(self.answers)?;
|
||||||
|
buffer.write_u16(self.authoritative_entries)?;
|
||||||
|
buffer.write_u16(self.resource_entries)?;
|
||||||
|
|
||||||
|
Ok(())
|
||||||
|
}
|
||||||
|
}
|
||||||
12
src/lib.rs
Normal file
12
src/lib.rs
Normal file
@@ -0,0 +1,12 @@
|
|||||||
|
pub mod buffer;
|
||||||
|
pub mod cache;
|
||||||
|
pub mod config;
|
||||||
|
pub mod forward;
|
||||||
|
pub mod header;
|
||||||
|
pub mod packet;
|
||||||
|
pub mod question;
|
||||||
|
pub mod record;
|
||||||
|
pub mod stats;
|
||||||
|
|
||||||
|
pub type Error = Box<dyn std::error::Error + Send + Sync>;
|
||||||
|
pub type Result<T> = std::result::Result<T, Error>;
|
||||||
915
src/main.rs
915
src/main.rs
@@ -1,801 +1,144 @@
|
|||||||
use std::fs::File;
|
use std::collections::HashMap;
|
||||||
use std::io::Read;
|
use std::net::SocketAddr;
|
||||||
use std::net::Ipv4Addr;
|
use std::sync::{Arc, Mutex};
|
||||||
use std::net::Ipv6Addr;
|
use std::time::{Duration, Instant};
|
||||||
|
|
||||||
type Error = Box<dyn std::error::Error>;
|
use log::{debug, error, info, warn};
|
||||||
type Result<T> = std::result::Result<T, Error>;
|
use tokio::net::UdpSocket;
|
||||||
|
|
||||||
pub struct BytePacketBuffer {
|
use dns_fun::buffer::BytePacketBuffer;
|
||||||
pub buf: [u8; 512],
|
use dns_fun::cache::DnsCache;
|
||||||
pub pos: usize,
|
use dns_fun::config::{build_zone_map, load_config};
|
||||||
|
use dns_fun::forward::forward_query;
|
||||||
|
use dns_fun::header::ResultCode;
|
||||||
|
use dns_fun::packet::DnsPacket;
|
||||||
|
use dns_fun::question::QueryType;
|
||||||
|
use dns_fun::record::DnsRecord;
|
||||||
|
use dns_fun::stats::{QueryPath, ServerStats};
|
||||||
|
|
||||||
|
struct ServerCtx {
|
||||||
|
socket: Arc<UdpSocket>,
|
||||||
|
zone_map: HashMap<(String, QueryType), Vec<DnsRecord>>,
|
||||||
|
cache: Mutex<DnsCache>,
|
||||||
|
stats: Mutex<ServerStats>,
|
||||||
|
upstream: SocketAddr,
|
||||||
|
timeout: Duration,
|
||||||
}
|
}
|
||||||
|
|
||||||
impl BytePacketBuffer {
|
#[tokio::main]
|
||||||
|
async fn main() -> dns_fun::Result<()> {
|
||||||
/// This gives us a fresh buffer for holding the packet contents, and a
|
env_logger::Builder::from_env(env_logger::Env::default().default_filter_or("info"))
|
||||||
/// field for keeping track of where we are.
|
.format_timestamp_millis()
|
||||||
pub fn new() -> BytePacketBuffer {
|
.init();
|
||||||
BytePacketBuffer {
|
|
||||||
buf: [0; 512],
|
let config_path = std::env::args().nth(1).unwrap_or_else(|| "dns_fun.toml".to_string());
|
||||||
pos: 0,
|
let config = load_config(&config_path)?;
|
||||||
}
|
|
||||||
}
|
let upstream: SocketAddr = format!("{}:{}", config.upstream.address, config.upstream.port).parse()?;
|
||||||
|
let socket = Arc::new(UdpSocket::bind(&config.server.bind_addr).await?);
|
||||||
/// Current position within buffer
|
|
||||||
fn pos(&self) -> usize {
|
let ctx = Arc::new(ServerCtx {
|
||||||
self.pos
|
socket: Arc::clone(&socket),
|
||||||
}
|
zone_map: build_zone_map(&config.zones)?,
|
||||||
|
cache: Mutex::new(DnsCache::new(
|
||||||
/// Step the buffer position forward a specific number of steps
|
config.cache.max_entries,
|
||||||
fn step(&mut self, steps: usize) -> Result<()> {
|
config.cache.min_ttl,
|
||||||
self.pos += steps;
|
config.cache.max_ttl,
|
||||||
|
)),
|
||||||
Ok(())
|
stats: Mutex::new(ServerStats::new()),
|
||||||
}
|
upstream,
|
||||||
|
timeout: Duration::from_millis(config.upstream.timeout_ms),
|
||||||
/// Change the buffer position
|
});
|
||||||
fn seek(&mut self, pos: usize) -> Result<()> {
|
|
||||||
self.pos = pos;
|
info!(
|
||||||
|
"dns_fun starting on {}, upstream {}, {} zone records, cache max {}",
|
||||||
Ok(())
|
config.server.bind_addr,
|
||||||
}
|
upstream,
|
||||||
|
ctx.zone_map.len(),
|
||||||
/// Read a single byte and move the position one step forward
|
config.cache.max_entries,
|
||||||
fn read(&mut self) -> Result<u8> {
|
|
||||||
if self.pos >= 512 {
|
|
||||||
return Err("End of buffer".into());
|
|
||||||
}
|
|
||||||
let res = self.buf[self.pos];
|
|
||||||
self.pos += 1;
|
|
||||||
|
|
||||||
Ok(res)
|
|
||||||
}
|
|
||||||
|
|
||||||
/// Get a single byte, without changing the buffer position
|
|
||||||
fn get(&mut self, pos: usize) -> Result<u8> {
|
|
||||||
if pos >= 512 {
|
|
||||||
return Err("End of buffer".into());
|
|
||||||
}
|
|
||||||
Ok(self.buf[pos])
|
|
||||||
}
|
|
||||||
|
|
||||||
/// Get a range of bytes
|
|
||||||
fn get_range(&mut self, start: usize, len: usize) -> Result<&[u8]> {
|
|
||||||
if start + len >= 512 {
|
|
||||||
return Err("End of buffer".into());
|
|
||||||
}
|
|
||||||
Ok(&self.buf[start..start + len as usize])
|
|
||||||
}
|
|
||||||
|
|
||||||
/// Read two bytes, stepping two steps forward
|
|
||||||
fn read_u16(&mut self) -> Result<u16> {
|
|
||||||
let res = ((self.read()? as u16) << 8) | (self.read()? as u16);
|
|
||||||
|
|
||||||
Ok(res)
|
|
||||||
}
|
|
||||||
|
|
||||||
/// Read four bytes, stepping four steps forward
|
|
||||||
fn read_u32(&mut self) -> Result<u32> {
|
|
||||||
let res = ((self.read()? as u32) << 24)
|
|
||||||
| ((self.read()? as u32) << 16)
|
|
||||||
| ((self.read()? as u32) << 8)
|
|
||||||
| ((self.read()? as u32) << 0);
|
|
||||||
|
|
||||||
Ok(res)
|
|
||||||
}
|
|
||||||
|
|
||||||
|
|
||||||
/// Read a qname
|
|
||||||
///
|
|
||||||
/// The tricky part: Reading domain names, taking labels into consideration.
|
|
||||||
/// Will take something like [3]www[6]google[3]com[0] and append
|
|
||||||
/// www.google.com to outstr.
|
|
||||||
fn read_qname(&mut self, outstr: &mut String) -> Result<()> {
|
|
||||||
// Since we might encounter jumps, we'll keep track of our position
|
|
||||||
// locally as opposed to using the position within the struct. This
|
|
||||||
// allows us to move the shared position to a point past our current
|
|
||||||
// qname, while keeping track of our progress on the current qname
|
|
||||||
// using this variable.
|
|
||||||
let mut pos = self.pos();
|
|
||||||
|
|
||||||
// track whether or not we've jumped
|
|
||||||
let mut jumped = false;
|
|
||||||
let max_jumps = 5;
|
|
||||||
let mut jumps_performed = 0;
|
|
||||||
|
|
||||||
// Our delimiter which we append for each label. Since we don't want a
|
|
||||||
// dot at the beginning of the domain name we'll leave it empty for now
|
|
||||||
// and set it to "." at the end of the first iteration.
|
|
||||||
let mut delim = "";
|
|
||||||
loop {
|
|
||||||
// Dns Packets are untrusted data, so we need to be paranoid. Someone
|
|
||||||
// can craft a packet with a cycle in the jump instructions. This guards
|
|
||||||
// against such packets.
|
|
||||||
if jumps_performed > max_jumps {
|
|
||||||
return Err(format!("Limit of {} jumps exceeded", max_jumps).into());
|
|
||||||
}
|
|
||||||
|
|
||||||
// At this point, we're always at the beginning of a label. Recall
|
|
||||||
// that labels start with a length byte.
|
|
||||||
let len = self.get(pos)?;
|
|
||||||
|
|
||||||
// If len has the two most significant bit are set, it represents a
|
|
||||||
// jump to some other offset in the packet:
|
|
||||||
if (len & 0xC0) == 0xC0 {
|
|
||||||
// Update the buffer position to a point past the current
|
|
||||||
// label. We don't need to touch it any further.
|
|
||||||
if !jumped {
|
|
||||||
self.seek(pos + 2)?;
|
|
||||||
}
|
|
||||||
|
|
||||||
// Read another byte, calculate offset and perform the jump by
|
|
||||||
// updating our local position variable
|
|
||||||
let b2 = self.get(pos + 1)? as u16;
|
|
||||||
let offset = (((len as u16) ^ 0xC0) << 8) | b2;
|
|
||||||
pos = offset as usize;
|
|
||||||
|
|
||||||
// Indicate that a jump was performed.
|
|
||||||
jumped = true;
|
|
||||||
jumps_performed += 1;
|
|
||||||
|
|
||||||
continue;
|
|
||||||
}
|
|
||||||
// The base scenario, where we're reading a single label and
|
|
||||||
// appending it to the output:
|
|
||||||
else {
|
|
||||||
// Move a single byte forward to move past the length byte.
|
|
||||||
pos += 1;
|
|
||||||
|
|
||||||
// Domain names are terminated by an empty label of length 0,
|
|
||||||
// so if the length is zero we're done.
|
|
||||||
if len == 0 {
|
|
||||||
break;
|
|
||||||
}
|
|
||||||
|
|
||||||
// Append the delimiter to our output buffer first.
|
|
||||||
outstr.push_str(delim);
|
|
||||||
|
|
||||||
// Extract the actual ASCII bytes for this label and append them
|
|
||||||
// to the output buffer.
|
|
||||||
let str_buffer = self.get_range(pos, len as usize)?;
|
|
||||||
outstr.push_str(&String::from_utf8_lossy(str_buffer).to_lowercase());
|
|
||||||
|
|
||||||
delim = ".";
|
|
||||||
|
|
||||||
// Move forward the full length of the label.
|
|
||||||
pos += len as usize;
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
if !jumped {
|
|
||||||
self.seek(pos)?;
|
|
||||||
}
|
|
||||||
|
|
||||||
Ok(())
|
|
||||||
}
|
|
||||||
fn write(&mut self, val: u8) -> Result<()> {
|
|
||||||
if self.pos >= 512 {
|
|
||||||
return Err("End of buffer".into());
|
|
||||||
}
|
|
||||||
self.buf[self.pos] = val;
|
|
||||||
self.pos += 1;
|
|
||||||
Ok(())
|
|
||||||
}
|
|
||||||
|
|
||||||
fn write_u8(&mut self, val: u8) -> Result<()> {
|
|
||||||
self.write(val)?;
|
|
||||||
|
|
||||||
Ok(())
|
|
||||||
}
|
|
||||||
|
|
||||||
fn write_u16(&mut self, val: u16) -> Result<()> {
|
|
||||||
self.write((val >> 8) as u8)?;
|
|
||||||
self.write((val & 0xFF) as u8)?;
|
|
||||||
|
|
||||||
Ok(())
|
|
||||||
}
|
|
||||||
|
|
||||||
fn write_u32(&mut self, val: u32) -> Result<()> {
|
|
||||||
self.write(((val >> 24) & 0xFF) as u8)?;
|
|
||||||
self.write(((val >> 16) & 0xFF) as u8)?;
|
|
||||||
self.write(((val >> 8) & 0xFF) as u8)?;
|
|
||||||
self.write(((val >> 0) & 0xFF) as u8)?;
|
|
||||||
|
|
||||||
Ok(())
|
|
||||||
}
|
|
||||||
|
|
||||||
fn write_qname(&mut self, qname: &str) -> Result<()> {
|
|
||||||
for label in qname.split('.') {
|
|
||||||
let len = label.len();
|
|
||||||
if len > 0x3f {
|
|
||||||
return Err("Single label exceeds 63 characters of length".into());
|
|
||||||
}
|
|
||||||
|
|
||||||
self.write_u8(len as u8)?;
|
|
||||||
for b in label.as_bytes() {
|
|
||||||
self.write_u8(*b)?;
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
self.write_u8(0)?;
|
|
||||||
|
|
||||||
Ok(())
|
|
||||||
}
|
|
||||||
|
|
||||||
fn set(&mut self, pos: usize, val: u8) -> Result<()> {
|
|
||||||
self.buf[pos] = val;
|
|
||||||
|
|
||||||
Ok(())
|
|
||||||
}
|
|
||||||
|
|
||||||
fn set_u16(&mut self, pos: usize, val: u16) -> Result<()> {
|
|
||||||
self.set(pos, (val >> 8) as u8)?;
|
|
||||||
self.set(pos + 1, (val & 0xFF) as u8)?;
|
|
||||||
|
|
||||||
Ok(())
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
#[derive(Copy, Clone, Debug, PartialEq, Eq)]
|
|
||||||
pub enum ResultCode {
|
|
||||||
NOERROR = 0,
|
|
||||||
FORMERR = 1,
|
|
||||||
SERVFAIL = 2,
|
|
||||||
NXDOMAIN = 3,
|
|
||||||
NOTIMP = 4,
|
|
||||||
REFUSED = 5,
|
|
||||||
}
|
|
||||||
|
|
||||||
impl ResultCode {
|
|
||||||
pub fn from_num(num: u8) -> ResultCode {
|
|
||||||
match num {
|
|
||||||
1 => ResultCode::FORMERR,
|
|
||||||
2 => ResultCode::SERVFAIL,
|
|
||||||
3 => ResultCode::NXDOMAIN,
|
|
||||||
4 => ResultCode::NOTIMP,
|
|
||||||
5 => ResultCode::REFUSED,
|
|
||||||
0 | _ => ResultCode::NOERROR,
|
|
||||||
}
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
#[derive(Clone, Debug)]
|
|
||||||
pub struct DnsHeader {
|
|
||||||
pub id: u16, // 16 bits
|
|
||||||
|
|
||||||
pub recursion_desired: bool, // 1 bit
|
|
||||||
pub truncated_message: bool, // 1 bit
|
|
||||||
pub authoritative_answer: bool, // 1 bit
|
|
||||||
pub opcode: u8, // 4 bits
|
|
||||||
pub response: bool, // 1 bit
|
|
||||||
|
|
||||||
pub rescode: ResultCode, // 4 bits
|
|
||||||
pub checking_disabled: bool, // 1 bit
|
|
||||||
pub authed_data: bool, // 1 bit
|
|
||||||
pub z: bool, // 1 bit
|
|
||||||
pub recursion_available: bool, // 1 bit
|
|
||||||
|
|
||||||
pub questions: u16, // 16 bits
|
|
||||||
pub answers: u16, // 16 bits
|
|
||||||
pub authoritative_entries: u16, // 16 bits
|
|
||||||
pub resource_entries: u16, // 16 bits
|
|
||||||
}
|
|
||||||
|
|
||||||
impl DnsHeader {
|
|
||||||
pub fn new() -> DnsHeader {
|
|
||||||
DnsHeader {
|
|
||||||
id: 0,
|
|
||||||
|
|
||||||
recursion_desired: false,
|
|
||||||
truncated_message: false,
|
|
||||||
authoritative_answer: false,
|
|
||||||
opcode: 0,
|
|
||||||
response: false,
|
|
||||||
|
|
||||||
rescode: ResultCode::NOERROR,
|
|
||||||
checking_disabled: false,
|
|
||||||
authed_data: false,
|
|
||||||
z: false,
|
|
||||||
recursion_available: false,
|
|
||||||
|
|
||||||
questions: 0,
|
|
||||||
answers: 0,
|
|
||||||
authoritative_entries: 0,
|
|
||||||
resource_entries: 0,
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
pub fn read(&mut self, buffer: &mut BytePacketBuffer) -> Result<()> {
|
|
||||||
self.id = buffer.read_u16()?;
|
|
||||||
|
|
||||||
let flags = buffer.read_u16()?;
|
|
||||||
let a = (flags >> 8) as u8;
|
|
||||||
let b = (flags & 0xFF) as u8;
|
|
||||||
self.recursion_desired = (a & (1 << 0)) > 0;
|
|
||||||
self.truncated_message = (a & (1 << 1)) > 0;
|
|
||||||
self.authoritative_answer = (a & (1 << 2)) > 0;
|
|
||||||
self.opcode = (a >> 3) & 0x0F;
|
|
||||||
self.response = (a & (1 << 7)) > 0;
|
|
||||||
|
|
||||||
self.rescode = ResultCode::from_num(b & 0x0F);
|
|
||||||
self.checking_disabled = (b & (1 << 4)) > 0;
|
|
||||||
self.authed_data = (b & (1 << 5)) > 0;
|
|
||||||
self.z = (b & (1 << 6)) > 0;
|
|
||||||
self.recursion_available = (b & (1 << 7)) > 0;
|
|
||||||
|
|
||||||
self.questions = buffer.read_u16()?;
|
|
||||||
self.answers = buffer.read_u16()?;
|
|
||||||
self.authoritative_entries = buffer.read_u16()?;
|
|
||||||
self.resource_entries = buffer.read_u16()?;
|
|
||||||
|
|
||||||
// Return the constant header size
|
|
||||||
Ok(())
|
|
||||||
}
|
|
||||||
|
|
||||||
pub fn write(&self, buffer: &mut BytePacketBuffer) -> Result<()> {
|
|
||||||
buffer.write_u16(self.id)?;
|
|
||||||
|
|
||||||
buffer.write_u8(
|
|
||||||
(self.recursion_desired as u8)
|
|
||||||
| ((self.truncated_message as u8) << 1)
|
|
||||||
| ((self.authoritative_answer as u8) << 2)
|
|
||||||
| (self.opcode << 3)
|
|
||||||
| ((self.response as u8) << 7) as u8,
|
|
||||||
)?;
|
|
||||||
|
|
||||||
buffer.write_u8(
|
|
||||||
(self.rescode as u8)
|
|
||||||
| ((self.checking_disabled as u8) << 4)
|
|
||||||
| ((self.authed_data as u8) << 5)
|
|
||||||
| ((self.z as u8) << 6)
|
|
||||||
| ((self.recursion_available as u8) << 7),
|
|
||||||
)?;
|
|
||||||
|
|
||||||
buffer.write_u16(self.questions)?;
|
|
||||||
buffer.write_u16(self.answers)?;
|
|
||||||
buffer.write_u16(self.authoritative_entries)?;
|
|
||||||
buffer.write_u16(self.resource_entries)?;
|
|
||||||
|
|
||||||
Ok(())
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
#[derive(PartialEq, Eq, Debug, Clone, Hash, Copy)]
|
|
||||||
pub enum QueryType {
|
|
||||||
UNKNOWN(u16),
|
|
||||||
A, // 1
|
|
||||||
NS, // 2
|
|
||||||
CNAME, // 5
|
|
||||||
MX, // 15
|
|
||||||
AAAA, // 28
|
|
||||||
}
|
|
||||||
|
|
||||||
impl QueryType {
|
|
||||||
pub fn to_num(&self) -> u16 {
|
|
||||||
match *self {
|
|
||||||
QueryType::UNKNOWN(x) => x,
|
|
||||||
QueryType::A => 1,
|
|
||||||
QueryType::NS => 2,
|
|
||||||
QueryType::CNAME => 5,
|
|
||||||
QueryType::MX => 15,
|
|
||||||
QueryType::AAAA => 28,
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
pub fn from_num(num: u16) -> QueryType {
|
|
||||||
match num {
|
|
||||||
1 => QueryType::A,
|
|
||||||
2 => QueryType::NS,
|
|
||||||
5 => QueryType::CNAME,
|
|
||||||
15 => QueryType::MX,
|
|
||||||
28 => QueryType::AAAA,
|
|
||||||
_ => QueryType::UNKNOWN(num),
|
|
||||||
}
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
#[derive(Debug, Clone, PartialEq, Eq)]
|
|
||||||
pub struct DnsQuestion {
|
|
||||||
pub name: String,
|
|
||||||
pub qtype: QueryType,
|
|
||||||
}
|
|
||||||
|
|
||||||
impl DnsQuestion {
|
|
||||||
pub fn new(name: String, qtype: QueryType) -> DnsQuestion {
|
|
||||||
DnsQuestion {
|
|
||||||
name: name,
|
|
||||||
qtype: qtype,
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
pub fn read(&mut self, buffer: &mut BytePacketBuffer) -> Result<()> {
|
|
||||||
buffer.read_qname(&mut self.name)?;
|
|
||||||
self.qtype = QueryType::from_num(buffer.read_u16()?); // qtype
|
|
||||||
let _ = buffer.read_u16()?; // class
|
|
||||||
|
|
||||||
Ok(())
|
|
||||||
}
|
|
||||||
|
|
||||||
pub fn write(&self, buffer: &mut BytePacketBuffer) -> Result<()> {
|
|
||||||
buffer.write_qname(&self.name)?;
|
|
||||||
|
|
||||||
let typenum = self.qtype.to_num();
|
|
||||||
buffer.write_u16(typenum)?;
|
|
||||||
buffer.write_u16(1)?;
|
|
||||||
|
|
||||||
Ok(())
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
#[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
|
|
||||||
#[allow(dead_code)]
|
|
||||||
pub enum DnsRecord {
|
|
||||||
UNKNOWN {
|
|
||||||
domain: String,
|
|
||||||
qtype: u16,
|
|
||||||
data_len: u16,
|
|
||||||
ttl: u32,
|
|
||||||
}, // 0
|
|
||||||
A {
|
|
||||||
domain: String,
|
|
||||||
addr: Ipv4Addr,
|
|
||||||
ttl: u32,
|
|
||||||
}, // 1
|
|
||||||
NS {
|
|
||||||
domain: String,
|
|
||||||
host: String,
|
|
||||||
ttl: u32,
|
|
||||||
}, // 2
|
|
||||||
CNAME {
|
|
||||||
domain: String,
|
|
||||||
host: String,
|
|
||||||
ttl: u32,
|
|
||||||
}, // 5
|
|
||||||
MX {
|
|
||||||
domain: String,
|
|
||||||
priority: u16,
|
|
||||||
host: String,
|
|
||||||
ttl: u32,
|
|
||||||
}, // 15
|
|
||||||
AAAA {
|
|
||||||
domain: String,
|
|
||||||
addr: Ipv6Addr,
|
|
||||||
ttl: u32,
|
|
||||||
}, // 28
|
|
||||||
}
|
|
||||||
|
|
||||||
impl DnsRecord {
|
|
||||||
pub fn read(buffer: &mut BytePacketBuffer) -> Result<DnsRecord> {
|
|
||||||
let mut domain = String::new();
|
|
||||||
buffer.read_qname(&mut domain)?;
|
|
||||||
|
|
||||||
let qtype_num = buffer.read_u16()?;
|
|
||||||
let qtype = QueryType::from_num(qtype_num);
|
|
||||||
let _ = buffer.read_u16()?;
|
|
||||||
let ttl = buffer.read_u32()?;
|
|
||||||
let data_len = buffer.read_u16()?;
|
|
||||||
|
|
||||||
match qtype {
|
|
||||||
QueryType::A => {
|
|
||||||
let raw_addr = buffer.read_u32()?;
|
|
||||||
let addr = Ipv4Addr::new(
|
|
||||||
((raw_addr >> 24) & 0xFF) as u8,
|
|
||||||
((raw_addr >> 16) & 0xFF) as u8,
|
|
||||||
((raw_addr >> 8) & 0xFF) as u8,
|
|
||||||
((raw_addr >> 0) & 0xFF) as u8,
|
|
||||||
);
|
);
|
||||||
|
|
||||||
Ok(DnsRecord::A {
|
|
||||||
domain: domain,
|
|
||||||
addr: addr,
|
|
||||||
ttl: ttl,
|
|
||||||
})
|
|
||||||
}
|
|
||||||
QueryType::AAAA => {
|
|
||||||
let raw_addr1 = buffer.read_u32()?;
|
|
||||||
let raw_addr2 = buffer.read_u32()?;
|
|
||||||
let raw_addr3 = buffer.read_u32()?;
|
|
||||||
let raw_addr4 = buffer.read_u32()?;
|
|
||||||
let addr = Ipv6Addr::new(
|
|
||||||
((raw_addr1 >> 16) & 0xFFFF) as u16,
|
|
||||||
((raw_addr1 >> 0) & 0xFFFF) as u16,
|
|
||||||
((raw_addr2 >> 16) & 0xFFFF) as u16,
|
|
||||||
((raw_addr2 >> 0) & 0xFFFF) as u16,
|
|
||||||
((raw_addr3 >> 16) & 0xFFFF) as u16,
|
|
||||||
((raw_addr3 >> 0) & 0xFFFF) as u16,
|
|
||||||
((raw_addr4 >> 16) & 0xFFFF) as u16,
|
|
||||||
((raw_addr4 >> 0) & 0xFFFF) as u16,
|
|
||||||
);
|
|
||||||
|
|
||||||
Ok(DnsRecord::AAAA {
|
|
||||||
domain: domain,
|
|
||||||
addr: addr,
|
|
||||||
ttl: ttl,
|
|
||||||
})
|
|
||||||
}
|
|
||||||
QueryType::NS => {
|
|
||||||
let mut ns = String::new();
|
|
||||||
buffer.read_qname(&mut ns)?;
|
|
||||||
|
|
||||||
Ok(DnsRecord::NS {
|
|
||||||
domain: domain,
|
|
||||||
host: ns,
|
|
||||||
ttl: ttl,
|
|
||||||
})
|
|
||||||
}
|
|
||||||
QueryType::CNAME => {
|
|
||||||
let mut cname = String::new();
|
|
||||||
buffer.read_qname(&mut cname)?;
|
|
||||||
|
|
||||||
Ok(DnsRecord::CNAME {
|
|
||||||
domain: domain,
|
|
||||||
host: cname,
|
|
||||||
ttl: ttl,
|
|
||||||
})
|
|
||||||
}
|
|
||||||
QueryType::MX => {
|
|
||||||
let priority = buffer.read_u16()?;
|
|
||||||
let mut mx = String::new();
|
|
||||||
buffer.read_qname(&mut mx)?;
|
|
||||||
|
|
||||||
Ok(DnsRecord::MX {
|
|
||||||
domain: domain,
|
|
||||||
priority: priority,
|
|
||||||
host: mx,
|
|
||||||
ttl: ttl,
|
|
||||||
})
|
|
||||||
}
|
|
||||||
QueryType::UNKNOWN(_) => {
|
|
||||||
buffer.step(data_len as usize)?;
|
|
||||||
|
|
||||||
Ok(DnsRecord::UNKNOWN {
|
|
||||||
domain: domain,
|
|
||||||
qtype: qtype_num,
|
|
||||||
data_len: data_len,
|
|
||||||
ttl: ttl,
|
|
||||||
})
|
|
||||||
}
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
pub fn write(&self, buffer: &mut BytePacketBuffer) -> Result<usize> {
|
|
||||||
let start_pos = buffer.pos();
|
|
||||||
|
|
||||||
match *self {
|
|
||||||
DnsRecord::A {
|
|
||||||
ref domain,
|
|
||||||
ref addr,
|
|
||||||
ttl,
|
|
||||||
} => {
|
|
||||||
buffer.write_qname(domain)?;
|
|
||||||
buffer.write_u16(QueryType::A.to_num())?;
|
|
||||||
buffer.write_u16(1)?;
|
|
||||||
buffer.write_u32(ttl)?;
|
|
||||||
buffer.write_u16(4)?;
|
|
||||||
|
|
||||||
let octets = addr.octets();
|
|
||||||
buffer.write_u8(octets[0])?;
|
|
||||||
buffer.write_u8(octets[1])?;
|
|
||||||
buffer.write_u8(octets[2])?;
|
|
||||||
buffer.write_u8(octets[3])?;
|
|
||||||
}
|
|
||||||
DnsRecord::NS {
|
|
||||||
ref domain,
|
|
||||||
ref host,
|
|
||||||
ttl,
|
|
||||||
} => {
|
|
||||||
buffer.write_qname(domain)?;
|
|
||||||
buffer.write_u16(QueryType::NS.to_num())?;
|
|
||||||
buffer.write_u16(1)?;
|
|
||||||
buffer.write_u32(ttl)?;
|
|
||||||
|
|
||||||
let pos = buffer.pos();
|
|
||||||
buffer.write_u16(0)?;
|
|
||||||
|
|
||||||
buffer.write_qname(host)?;
|
|
||||||
|
|
||||||
let size = buffer.pos() - (pos + 2);
|
|
||||||
buffer.set_u16(pos, size as u16)?;
|
|
||||||
}
|
|
||||||
DnsRecord::CNAME {
|
|
||||||
ref domain,
|
|
||||||
ref host,
|
|
||||||
ttl,
|
|
||||||
} => {
|
|
||||||
buffer.write_qname(domain)?;
|
|
||||||
buffer.write_u16(QueryType::CNAME.to_num())?;
|
|
||||||
buffer.write_u16(1)?;
|
|
||||||
buffer.write_u32(ttl)?;
|
|
||||||
|
|
||||||
let pos = buffer.pos();
|
|
||||||
buffer.write_u16(0)?;
|
|
||||||
|
|
||||||
buffer.write_qname(host)?;
|
|
||||||
|
|
||||||
let size = buffer.pos() - (pos + 2);
|
|
||||||
buffer.set_u16(pos, size as u16)?;
|
|
||||||
}
|
|
||||||
DnsRecord::MX {
|
|
||||||
ref domain,
|
|
||||||
priority,
|
|
||||||
ref host,
|
|
||||||
ttl,
|
|
||||||
} => {
|
|
||||||
buffer.write_qname(domain)?;
|
|
||||||
buffer.write_u16(QueryType::MX.to_num())?;
|
|
||||||
buffer.write_u16(1)?;
|
|
||||||
buffer.write_u32(ttl)?;
|
|
||||||
|
|
||||||
let pos = buffer.pos();
|
|
||||||
buffer.write_u16(0)?;
|
|
||||||
|
|
||||||
buffer.write_u16(priority)?;
|
|
||||||
buffer.write_qname(host)?;
|
|
||||||
|
|
||||||
let size = buffer.pos() - (pos + 2);
|
|
||||||
buffer.set_u16(pos, size as u16)?;
|
|
||||||
}
|
|
||||||
DnsRecord::AAAA {
|
|
||||||
ref domain,
|
|
||||||
ref addr,
|
|
||||||
ttl,
|
|
||||||
} => {
|
|
||||||
buffer.write_qname(domain)?;
|
|
||||||
buffer.write_u16(QueryType::AAAA.to_num())?;
|
|
||||||
buffer.write_u16(1)?;
|
|
||||||
buffer.write_u32(ttl)?;
|
|
||||||
buffer.write_u16(16)?;
|
|
||||||
|
|
||||||
for octet in &addr.segments() {
|
|
||||||
buffer.write_u16(*octet)?;
|
|
||||||
}
|
|
||||||
}
|
|
||||||
DnsRecord::UNKNOWN { .. } => {
|
|
||||||
println!("Skipping record: {:?}", self);
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
Ok(buffer.pos() - start_pos)
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
#[derive(Clone, Debug)]
|
|
||||||
pub struct DnsPacket {
|
|
||||||
pub header: DnsHeader,
|
|
||||||
pub questions: Vec<DnsQuestion>,
|
|
||||||
pub answers: Vec<DnsRecord>,
|
|
||||||
pub authorities: Vec<DnsRecord>,
|
|
||||||
pub resources: Vec<DnsRecord>,
|
|
||||||
}
|
|
||||||
|
|
||||||
impl DnsPacket {
|
|
||||||
pub fn new() -> DnsPacket {
|
|
||||||
DnsPacket {
|
|
||||||
header: DnsHeader::new(),
|
|
||||||
questions: Vec::new(),
|
|
||||||
answers: Vec::new(),
|
|
||||||
authorities: Vec::new(),
|
|
||||||
resources: Vec::new(),
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
pub fn from_buffer(buffer: &mut BytePacketBuffer) -> Result<DnsPacket> {
|
|
||||||
let mut result = DnsPacket::new();
|
|
||||||
result.header.read(buffer)?;
|
|
||||||
|
|
||||||
for _ in 0..result.header.questions {
|
|
||||||
let mut question = DnsQuestion::new("".to_string(), QueryType::UNKNOWN(0));
|
|
||||||
question.read(buffer)?;
|
|
||||||
result.questions.push(question);
|
|
||||||
}
|
|
||||||
|
|
||||||
for _ in 0..result.header.answers {
|
|
||||||
let rec = DnsRecord::read(buffer)?;
|
|
||||||
result.answers.push(rec);
|
|
||||||
}
|
|
||||||
for _ in 0..result.header.authoritative_entries {
|
|
||||||
let rec = DnsRecord::read(buffer)?;
|
|
||||||
result.authorities.push(rec);
|
|
||||||
}
|
|
||||||
for _ in 0..result.header.resource_entries {
|
|
||||||
let rec = DnsRecord::read(buffer)?;
|
|
||||||
result.resources.push(rec);
|
|
||||||
}
|
|
||||||
|
|
||||||
Ok(result)
|
|
||||||
}
|
|
||||||
|
|
||||||
pub fn write(&mut self, buffer: &mut BytePacketBuffer) -> Result<()> {
|
|
||||||
self.header.questions = self.questions.len() as u16;
|
|
||||||
self.header.answers = self.answers.len() as u16;
|
|
||||||
self.header.authoritative_entries = self.authorities.len() as u16;
|
|
||||||
self.header.resource_entries = self.resources.len() as u16;
|
|
||||||
|
|
||||||
self.header.write(buffer)?;
|
|
||||||
|
|
||||||
for question in &self.questions {
|
|
||||||
question.write(buffer)?;
|
|
||||||
}
|
|
||||||
for rec in &self.answers {
|
|
||||||
rec.write(buffer)?;
|
|
||||||
}
|
|
||||||
for rec in &self.authorities {
|
|
||||||
rec.write(buffer)?;
|
|
||||||
}
|
|
||||||
for rec in &self.resources {
|
|
||||||
rec.write(buffer)?;
|
|
||||||
}
|
|
||||||
|
|
||||||
Ok(())
|
|
||||||
}
|
|
||||||
|
|
||||||
pub fn display(&self) {
|
|
||||||
println!("{:#?}", self.header);
|
|
||||||
|
|
||||||
for q in &self.questions {
|
|
||||||
println!("{:#?}", q);
|
|
||||||
}
|
|
||||||
for rec in &self.answers {
|
|
||||||
println!("{:#?}", rec);
|
|
||||||
}
|
|
||||||
for rec in &self.authorities {
|
|
||||||
println!("{:#?}", rec);
|
|
||||||
}
|
|
||||||
for rec in &self.resources {
|
|
||||||
println!("{:#?}", rec);
|
|
||||||
}
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
/*fn main() -> Result<()> {
|
|
||||||
let mut f = File::open("response_packet.txt")?;
|
|
||||||
let mut buffer = BytePacketBuffer::new();
|
|
||||||
f.read(&mut buffer.buf)?;
|
|
||||||
|
|
||||||
let packet = DnsPacket::from_buffer(&mut buffer)?;
|
|
||||||
println!("{:#?}", packet.header);
|
|
||||||
|
|
||||||
for q in packet.questions {
|
|
||||||
println!("{:#?}", q);
|
|
||||||
}
|
|
||||||
for rec in packet.answers {
|
|
||||||
println!("{:#?}", rec);
|
|
||||||
}
|
|
||||||
for rec in packet.authorities {
|
|
||||||
println!("{:#?}", rec);
|
|
||||||
}
|
|
||||||
for rec in packet.resources {
|
|
||||||
println!("{:#?}", rec);
|
|
||||||
}
|
|
||||||
|
|
||||||
Ok(())
|
|
||||||
}*/
|
|
||||||
|
|
||||||
use std::net::UdpSocket;
|
|
||||||
|
|
||||||
fn main() -> std::io::Result<()> {
|
|
||||||
let socket = UdpSocket::bind("0.0.0.0:53")?;
|
|
||||||
loop {
|
loop {
|
||||||
let mut buffer = BytePacketBuffer::new();
|
let mut buffer = BytePacketBuffer::new();
|
||||||
let (number_of_bytes, src_addr) = socket.recv_from(&mut buffer.buf)?;
|
let (_, src_addr) = socket.recv_from(&mut buffer.buf).await?;
|
||||||
print!("received: {} from {} \n", number_of_bytes, src_addr);
|
|
||||||
|
|
||||||
let packet = DnsPacket::from_buffer(&mut buffer).unwrap();
|
let ctx = Arc::clone(&ctx);
|
||||||
packet.display();
|
tokio::spawn(async move {
|
||||||
|
if let Err(e) = handle_query(buffer, src_addr, &ctx).await {
|
||||||
|
error!("{} | HANDLER ERROR | {}", src_addr, e);
|
||||||
|
}
|
||||||
|
});
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
let mut resp = DnsPacket::new();
|
async fn handle_query(
|
||||||
resp.header.id = packet.header.id;
|
mut buffer: BytePacketBuffer,
|
||||||
resp.header.authoritative_answer = true;
|
src_addr: SocketAddr,
|
||||||
resp.header.response = true;
|
ctx: &ServerCtx,
|
||||||
resp.questions = packet.questions;
|
) -> dns_fun::Result<()> {
|
||||||
resp.answers.push(DnsRecord::A{domain: "dimescu.ro".to_string(), addr: Ipv4Addr::new(3, 120, 139, 105), ttl: 30});
|
let start = Instant::now();
|
||||||
resp.display();
|
|
||||||
|
|
||||||
let mut req_buffer = BytePacketBuffer::new();
|
let query = match DnsPacket::from_buffer(&mut buffer) {
|
||||||
resp.write(&mut req_buffer).unwrap();
|
Ok(packet) => packet,
|
||||||
|
Err(e) => {
|
||||||
|
warn!("{} | PARSE ERROR | {}", src_addr, e);
|
||||||
|
return Ok(());
|
||||||
|
}
|
||||||
|
};
|
||||||
|
|
||||||
socket.send_to(&req_buffer.buf[0..req_buffer.pos], src_addr).unwrap();
|
let (qname, qtype) = match query.questions.first() {
|
||||||
|
Some(q) => (q.name.clone(), q.qtype),
|
||||||
|
None => return Ok(()),
|
||||||
|
};
|
||||||
|
|
||||||
|
// Pipeline: local zones -> cache -> upstream
|
||||||
|
// Each lock is scoped to avoid holding MutexGuard across await points.
|
||||||
|
let (response, path) = if let Some(records) = ctx.zone_map.get(&(qname.to_lowercase(), qtype)) {
|
||||||
|
let mut resp = DnsPacket::response_from(&query, ResultCode::NOERROR);
|
||||||
|
resp.answers = records.clone();
|
||||||
|
(resp, QueryPath::Local)
|
||||||
|
} else {
|
||||||
|
let cached = ctx.cache.lock().unwrap().lookup(&qname, qtype);
|
||||||
|
if let Some(cached) = cached {
|
||||||
|
let mut resp = cached;
|
||||||
|
resp.header.id = query.header.id;
|
||||||
|
(resp, QueryPath::Cached)
|
||||||
|
} else {
|
||||||
|
match forward_query(&query, ctx.upstream, ctx.timeout).await {
|
||||||
|
Ok(resp) => {
|
||||||
|
ctx.cache.lock().unwrap().insert(&qname, qtype, &resp);
|
||||||
|
(resp, QueryPath::Forwarded)
|
||||||
|
}
|
||||||
|
Err(e) => {
|
||||||
|
error!("{} | {:?} {} | UPSTREAM ERROR | {}", src_addr, qtype, qname, e);
|
||||||
|
(DnsPacket::response_from(&query, ResultCode::SERVFAIL), QueryPath::UpstreamError)
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
};
|
||||||
|
|
||||||
|
let elapsed = start.elapsed();
|
||||||
|
|
||||||
|
info!(
|
||||||
|
"{} | {:?} {} | {} | {} | {}ms",
|
||||||
|
src_addr, qtype, qname, path.as_str(),
|
||||||
|
response.header.rescode.as_str(), elapsed.as_millis(),
|
||||||
|
);
|
||||||
|
|
||||||
|
debug!(
|
||||||
|
"response: {} answers, {} authorities, {} resources",
|
||||||
|
response.answers.len(), response.authorities.len(), response.resources.len(),
|
||||||
|
);
|
||||||
|
|
||||||
|
let mut resp_buffer = BytePacketBuffer::new();
|
||||||
|
response.write(&mut resp_buffer)?;
|
||||||
|
ctx.socket.send_to(resp_buffer.filled(), src_addr).await?;
|
||||||
|
|
||||||
|
// Record stats and log summary every 1000 queries (single lock acquisition)
|
||||||
|
let mut s = ctx.stats.lock().unwrap();
|
||||||
|
let total = s.record(path);
|
||||||
|
if total % 1000 == 0 {
|
||||||
|
s.log_summary();
|
||||||
}
|
}
|
||||||
|
|
||||||
Ok(())
|
Ok(())
|
||||||
|
|||||||
105
src/packet.rs
Normal file
105
src/packet.rs
Normal file
@@ -0,0 +1,105 @@
|
|||||||
|
use crate::buffer::BytePacketBuffer;
|
||||||
|
use crate::header::DnsHeader;
|
||||||
|
use crate::question::{DnsQuestion, QueryType};
|
||||||
|
use crate::record::DnsRecord;
|
||||||
|
use crate::Result;
|
||||||
|
|
||||||
|
#[derive(Clone, Debug)]
|
||||||
|
pub struct DnsPacket {
|
||||||
|
pub header: DnsHeader,
|
||||||
|
pub questions: Vec<DnsQuestion>,
|
||||||
|
pub answers: Vec<DnsRecord>,
|
||||||
|
pub authorities: Vec<DnsRecord>,
|
||||||
|
pub resources: Vec<DnsRecord>,
|
||||||
|
}
|
||||||
|
|
||||||
|
impl DnsPacket {
|
||||||
|
pub fn new() -> DnsPacket {
|
||||||
|
DnsPacket {
|
||||||
|
header: DnsHeader::new(),
|
||||||
|
questions: Vec::new(),
|
||||||
|
answers: Vec::new(),
|
||||||
|
authorities: Vec::new(),
|
||||||
|
resources: Vec::new(),
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn response_from(query: &DnsPacket, rescode: crate::header::ResultCode) -> DnsPacket {
|
||||||
|
let mut resp = DnsPacket::new();
|
||||||
|
resp.header.id = query.header.id;
|
||||||
|
resp.header.response = true;
|
||||||
|
resp.header.recursion_desired = query.header.recursion_desired;
|
||||||
|
resp.header.recursion_available = true;
|
||||||
|
resp.header.rescode = rescode;
|
||||||
|
resp.questions = query.questions.clone();
|
||||||
|
resp
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn from_buffer(buffer: &mut BytePacketBuffer) -> Result<DnsPacket> {
|
||||||
|
let mut result = DnsPacket::new();
|
||||||
|
result.header.read(buffer)?;
|
||||||
|
|
||||||
|
for _ in 0..result.header.questions {
|
||||||
|
let mut question = DnsQuestion::new("".to_string(), QueryType::UNKNOWN(0));
|
||||||
|
question.read(buffer)?;
|
||||||
|
result.questions.push(question);
|
||||||
|
}
|
||||||
|
|
||||||
|
for _ in 0..result.header.answers {
|
||||||
|
let rec = DnsRecord::read(buffer)?;
|
||||||
|
result.answers.push(rec);
|
||||||
|
}
|
||||||
|
for _ in 0..result.header.authoritative_entries {
|
||||||
|
let rec = DnsRecord::read(buffer)?;
|
||||||
|
result.authorities.push(rec);
|
||||||
|
}
|
||||||
|
for _ in 0..result.header.resource_entries {
|
||||||
|
let rec = DnsRecord::read(buffer)?;
|
||||||
|
result.resources.push(rec);
|
||||||
|
}
|
||||||
|
|
||||||
|
Ok(result)
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn write(&self, buffer: &mut BytePacketBuffer) -> Result<()> {
|
||||||
|
let mut header = self.header.clone();
|
||||||
|
header.questions = self.questions.len() as u16;
|
||||||
|
header.answers = self.answers.len() as u16;
|
||||||
|
header.authoritative_entries = self.authorities.len() as u16;
|
||||||
|
header.resource_entries = self.resources.len() as u16;
|
||||||
|
|
||||||
|
header.write(buffer)?;
|
||||||
|
|
||||||
|
for question in &self.questions {
|
||||||
|
question.write(buffer)?;
|
||||||
|
}
|
||||||
|
for rec in &self.answers {
|
||||||
|
rec.write(buffer)?;
|
||||||
|
}
|
||||||
|
for rec in &self.authorities {
|
||||||
|
rec.write(buffer)?;
|
||||||
|
}
|
||||||
|
for rec in &self.resources {
|
||||||
|
rec.write(buffer)?;
|
||||||
|
}
|
||||||
|
|
||||||
|
Ok(())
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn display(&self) {
|
||||||
|
println!("{:#?}", self.header);
|
||||||
|
|
||||||
|
for q in &self.questions {
|
||||||
|
println!("{:#?}", q);
|
||||||
|
}
|
||||||
|
for rec in &self.answers {
|
||||||
|
println!("{:#?}", rec);
|
||||||
|
}
|
||||||
|
for rec in &self.authorities {
|
||||||
|
println!("{:#?}", rec);
|
||||||
|
}
|
||||||
|
for rec in &self.resources {
|
||||||
|
println!("{:#?}", rec);
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
64
src/question.rs
Normal file
64
src/question.rs
Normal file
@@ -0,0 +1,64 @@
|
|||||||
|
use crate::buffer::BytePacketBuffer;
|
||||||
|
use crate::Result;
|
||||||
|
|
||||||
|
#[derive(PartialEq, Eq, Debug, Clone, Hash, Copy)]
|
||||||
|
pub enum QueryType {
|
||||||
|
UNKNOWN(u16),
|
||||||
|
A, // 1
|
||||||
|
NS, // 2
|
||||||
|
CNAME, // 5
|
||||||
|
MX, // 15
|
||||||
|
AAAA, // 28
|
||||||
|
}
|
||||||
|
|
||||||
|
impl QueryType {
|
||||||
|
pub fn to_num(&self) -> u16 {
|
||||||
|
match *self {
|
||||||
|
QueryType::UNKNOWN(x) => x,
|
||||||
|
QueryType::A => 1,
|
||||||
|
QueryType::NS => 2,
|
||||||
|
QueryType::CNAME => 5,
|
||||||
|
QueryType::MX => 15,
|
||||||
|
QueryType::AAAA => 28,
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn from_num(num: u16) -> QueryType {
|
||||||
|
match num {
|
||||||
|
1 => QueryType::A,
|
||||||
|
2 => QueryType::NS,
|
||||||
|
5 => QueryType::CNAME,
|
||||||
|
15 => QueryType::MX,
|
||||||
|
28 => QueryType::AAAA,
|
||||||
|
_ => QueryType::UNKNOWN(num),
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
#[derive(Debug, Clone, PartialEq, Eq)]
|
||||||
|
pub struct DnsQuestion {
|
||||||
|
pub name: String,
|
||||||
|
pub qtype: QueryType,
|
||||||
|
}
|
||||||
|
|
||||||
|
impl DnsQuestion {
|
||||||
|
pub fn new(name: String, qtype: QueryType) -> DnsQuestion {
|
||||||
|
DnsQuestion { name, qtype }
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn read(&mut self, buffer: &mut BytePacketBuffer) -> Result<()> {
|
||||||
|
buffer.read_qname(&mut self.name)?;
|
||||||
|
self.qtype = QueryType::from_num(buffer.read_u16()?);
|
||||||
|
let _ = buffer.read_u16()?; // class
|
||||||
|
|
||||||
|
Ok(())
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn write(&self, buffer: &mut BytePacketBuffer) -> Result<()> {
|
||||||
|
buffer.write_qname(&self.name)?;
|
||||||
|
buffer.write_u16(self.qtype.to_num())?;
|
||||||
|
buffer.write_u16(1)?;
|
||||||
|
|
||||||
|
Ok(())
|
||||||
|
}
|
||||||
|
}
|
||||||
249
src/record.rs
Normal file
249
src/record.rs
Normal file
@@ -0,0 +1,249 @@
|
|||||||
|
use std::net::Ipv4Addr;
|
||||||
|
use std::net::Ipv6Addr;
|
||||||
|
|
||||||
|
use crate::buffer::BytePacketBuffer;
|
||||||
|
use crate::question::QueryType;
|
||||||
|
use crate::Result;
|
||||||
|
|
||||||
|
#[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
|
||||||
|
#[allow(dead_code)]
|
||||||
|
pub enum DnsRecord {
|
||||||
|
UNKNOWN {
|
||||||
|
domain: String,
|
||||||
|
qtype: u16,
|
||||||
|
data_len: u16,
|
||||||
|
ttl: u32,
|
||||||
|
},
|
||||||
|
A {
|
||||||
|
domain: String,
|
||||||
|
addr: Ipv4Addr,
|
||||||
|
ttl: u32,
|
||||||
|
},
|
||||||
|
NS {
|
||||||
|
domain: String,
|
||||||
|
host: String,
|
||||||
|
ttl: u32,
|
||||||
|
},
|
||||||
|
CNAME {
|
||||||
|
domain: String,
|
||||||
|
host: String,
|
||||||
|
ttl: u32,
|
||||||
|
},
|
||||||
|
MX {
|
||||||
|
domain: String,
|
||||||
|
priority: u16,
|
||||||
|
host: String,
|
||||||
|
ttl: u32,
|
||||||
|
},
|
||||||
|
AAAA {
|
||||||
|
domain: String,
|
||||||
|
addr: Ipv6Addr,
|
||||||
|
ttl: u32,
|
||||||
|
},
|
||||||
|
}
|
||||||
|
|
||||||
|
impl DnsRecord {
|
||||||
|
pub fn ttl(&self) -> u32 {
|
||||||
|
match self {
|
||||||
|
DnsRecord::A { ttl, .. }
|
||||||
|
| DnsRecord::NS { ttl, .. }
|
||||||
|
| DnsRecord::CNAME { ttl, .. }
|
||||||
|
| DnsRecord::MX { ttl, .. }
|
||||||
|
| DnsRecord::AAAA { ttl, .. }
|
||||||
|
| DnsRecord::UNKNOWN { ttl, .. } => *ttl,
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn set_ttl(&mut self, new_ttl: u32) {
|
||||||
|
match self {
|
||||||
|
DnsRecord::A { ttl, .. }
|
||||||
|
| DnsRecord::NS { ttl, .. }
|
||||||
|
| DnsRecord::CNAME { ttl, .. }
|
||||||
|
| DnsRecord::MX { ttl, .. }
|
||||||
|
| DnsRecord::AAAA { ttl, .. }
|
||||||
|
| DnsRecord::UNKNOWN { ttl, .. } => *ttl = new_ttl,
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn read(buffer: &mut BytePacketBuffer) -> Result<DnsRecord> {
|
||||||
|
let mut domain = String::new();
|
||||||
|
buffer.read_qname(&mut domain)?;
|
||||||
|
|
||||||
|
let qtype_num = buffer.read_u16()?;
|
||||||
|
let qtype = QueryType::from_num(qtype_num);
|
||||||
|
let _ = buffer.read_u16()?;
|
||||||
|
let ttl = buffer.read_u32()?;
|
||||||
|
let data_len = buffer.read_u16()?;
|
||||||
|
|
||||||
|
match qtype {
|
||||||
|
QueryType::A => {
|
||||||
|
let raw_addr = buffer.read_u32()?;
|
||||||
|
let addr = Ipv4Addr::new(
|
||||||
|
((raw_addr >> 24) & 0xFF) as u8,
|
||||||
|
((raw_addr >> 16) & 0xFF) as u8,
|
||||||
|
((raw_addr >> 8) & 0xFF) as u8,
|
||||||
|
((raw_addr >> 0) & 0xFF) as u8,
|
||||||
|
);
|
||||||
|
|
||||||
|
Ok(DnsRecord::A { domain, addr, ttl })
|
||||||
|
}
|
||||||
|
QueryType::AAAA => {
|
||||||
|
let raw_addr1 = buffer.read_u32()?;
|
||||||
|
let raw_addr2 = buffer.read_u32()?;
|
||||||
|
let raw_addr3 = buffer.read_u32()?;
|
||||||
|
let raw_addr4 = buffer.read_u32()?;
|
||||||
|
let addr = Ipv6Addr::new(
|
||||||
|
((raw_addr1 >> 16) & 0xFFFF) as u16,
|
||||||
|
((raw_addr1 >> 0) & 0xFFFF) as u16,
|
||||||
|
((raw_addr2 >> 16) & 0xFFFF) as u16,
|
||||||
|
((raw_addr2 >> 0) & 0xFFFF) as u16,
|
||||||
|
((raw_addr3 >> 16) & 0xFFFF) as u16,
|
||||||
|
((raw_addr3 >> 0) & 0xFFFF) as u16,
|
||||||
|
((raw_addr4 >> 16) & 0xFFFF) as u16,
|
||||||
|
((raw_addr4 >> 0) & 0xFFFF) as u16,
|
||||||
|
);
|
||||||
|
|
||||||
|
Ok(DnsRecord::AAAA { domain, addr, ttl })
|
||||||
|
}
|
||||||
|
QueryType::NS => {
|
||||||
|
let mut ns = String::new();
|
||||||
|
buffer.read_qname(&mut ns)?;
|
||||||
|
|
||||||
|
Ok(DnsRecord::NS {
|
||||||
|
domain,
|
||||||
|
host: ns,
|
||||||
|
ttl,
|
||||||
|
})
|
||||||
|
}
|
||||||
|
QueryType::CNAME => {
|
||||||
|
let mut cname = String::new();
|
||||||
|
buffer.read_qname(&mut cname)?;
|
||||||
|
|
||||||
|
Ok(DnsRecord::CNAME {
|
||||||
|
domain,
|
||||||
|
host: cname,
|
||||||
|
ttl,
|
||||||
|
})
|
||||||
|
}
|
||||||
|
QueryType::MX => {
|
||||||
|
let priority = buffer.read_u16()?;
|
||||||
|
let mut mx = String::new();
|
||||||
|
buffer.read_qname(&mut mx)?;
|
||||||
|
|
||||||
|
Ok(DnsRecord::MX {
|
||||||
|
domain,
|
||||||
|
priority,
|
||||||
|
host: mx,
|
||||||
|
ttl,
|
||||||
|
})
|
||||||
|
}
|
||||||
|
QueryType::UNKNOWN(_) => {
|
||||||
|
buffer.step(data_len as usize)?;
|
||||||
|
|
||||||
|
Ok(DnsRecord::UNKNOWN {
|
||||||
|
domain,
|
||||||
|
qtype: qtype_num,
|
||||||
|
data_len,
|
||||||
|
ttl,
|
||||||
|
})
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn write(&self, buffer: &mut BytePacketBuffer) -> Result<usize> {
|
||||||
|
let start_pos = buffer.pos();
|
||||||
|
|
||||||
|
match *self {
|
||||||
|
DnsRecord::A {
|
||||||
|
ref domain,
|
||||||
|
ref addr,
|
||||||
|
ttl,
|
||||||
|
} => {
|
||||||
|
buffer.write_qname(domain)?;
|
||||||
|
buffer.write_u16(QueryType::A.to_num())?;
|
||||||
|
buffer.write_u16(1)?;
|
||||||
|
buffer.write_u32(ttl)?;
|
||||||
|
buffer.write_u16(4)?;
|
||||||
|
|
||||||
|
let octets = addr.octets();
|
||||||
|
buffer.write_u8(octets[0])?;
|
||||||
|
buffer.write_u8(octets[1])?;
|
||||||
|
buffer.write_u8(octets[2])?;
|
||||||
|
buffer.write_u8(octets[3])?;
|
||||||
|
}
|
||||||
|
DnsRecord::NS {
|
||||||
|
ref domain,
|
||||||
|
ref host,
|
||||||
|
ttl,
|
||||||
|
} => {
|
||||||
|
buffer.write_qname(domain)?;
|
||||||
|
buffer.write_u16(QueryType::NS.to_num())?;
|
||||||
|
buffer.write_u16(1)?;
|
||||||
|
buffer.write_u32(ttl)?;
|
||||||
|
|
||||||
|
let pos = buffer.pos();
|
||||||
|
buffer.write_u16(0)?;
|
||||||
|
buffer.write_qname(host)?;
|
||||||
|
|
||||||
|
let size = buffer.pos() - (pos + 2);
|
||||||
|
buffer.set_u16(pos, size as u16)?;
|
||||||
|
}
|
||||||
|
DnsRecord::CNAME {
|
||||||
|
ref domain,
|
||||||
|
ref host,
|
||||||
|
ttl,
|
||||||
|
} => {
|
||||||
|
buffer.write_qname(domain)?;
|
||||||
|
buffer.write_u16(QueryType::CNAME.to_num())?;
|
||||||
|
buffer.write_u16(1)?;
|
||||||
|
buffer.write_u32(ttl)?;
|
||||||
|
|
||||||
|
let pos = buffer.pos();
|
||||||
|
buffer.write_u16(0)?;
|
||||||
|
buffer.write_qname(host)?;
|
||||||
|
|
||||||
|
let size = buffer.pos() - (pos + 2);
|
||||||
|
buffer.set_u16(pos, size as u16)?;
|
||||||
|
}
|
||||||
|
DnsRecord::MX {
|
||||||
|
ref domain,
|
||||||
|
priority,
|
||||||
|
ref host,
|
||||||
|
ttl,
|
||||||
|
} => {
|
||||||
|
buffer.write_qname(domain)?;
|
||||||
|
buffer.write_u16(QueryType::MX.to_num())?;
|
||||||
|
buffer.write_u16(1)?;
|
||||||
|
buffer.write_u32(ttl)?;
|
||||||
|
|
||||||
|
let pos = buffer.pos();
|
||||||
|
buffer.write_u16(0)?;
|
||||||
|
buffer.write_u16(priority)?;
|
||||||
|
buffer.write_qname(host)?;
|
||||||
|
|
||||||
|
let size = buffer.pos() - (pos + 2);
|
||||||
|
buffer.set_u16(pos, size as u16)?;
|
||||||
|
}
|
||||||
|
DnsRecord::AAAA {
|
||||||
|
ref domain,
|
||||||
|
ref addr,
|
||||||
|
ttl,
|
||||||
|
} => {
|
||||||
|
buffer.write_qname(domain)?;
|
||||||
|
buffer.write_u16(QueryType::AAAA.to_num())?;
|
||||||
|
buffer.write_u16(1)?;
|
||||||
|
buffer.write_u32(ttl)?;
|
||||||
|
buffer.write_u16(16)?;
|
||||||
|
|
||||||
|
for octet in &addr.segments() {
|
||||||
|
buffer.write_u16(*octet)?;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
DnsRecord::UNKNOWN { .. } => {
|
||||||
|
println!("Skipping record: {:?}", self);
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
Ok(buffer.pos() - start_pos)
|
||||||
|
}
|
||||||
|
}
|
||||||
79
src/stats.rs
Normal file
79
src/stats.rs
Normal file
@@ -0,0 +1,79 @@
|
|||||||
|
use std::time::Instant;
|
||||||
|
|
||||||
|
pub struct ServerStats {
|
||||||
|
queries_total: u64,
|
||||||
|
queries_forwarded: u64,
|
||||||
|
queries_cached: u64,
|
||||||
|
queries_blocked: u64,
|
||||||
|
queries_local: u64,
|
||||||
|
upstream_errors: u64,
|
||||||
|
started_at: Instant,
|
||||||
|
}
|
||||||
|
|
||||||
|
pub enum QueryPath {
|
||||||
|
Local,
|
||||||
|
Cached,
|
||||||
|
Forwarded,
|
||||||
|
Blocked,
|
||||||
|
UpstreamError,
|
||||||
|
}
|
||||||
|
|
||||||
|
impl QueryPath {
|
||||||
|
pub fn as_str(&self) -> &'static str {
|
||||||
|
match self {
|
||||||
|
QueryPath::Local => "LOCAL",
|
||||||
|
QueryPath::Cached => "CACHED",
|
||||||
|
QueryPath::Forwarded => "FORWARD",
|
||||||
|
QueryPath::Blocked => "BLOCKED",
|
||||||
|
QueryPath::UpstreamError => "SERVFAIL",
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
impl ServerStats {
|
||||||
|
pub fn new() -> Self {
|
||||||
|
ServerStats {
|
||||||
|
queries_total: 0,
|
||||||
|
queries_forwarded: 0,
|
||||||
|
queries_cached: 0,
|
||||||
|
queries_blocked: 0,
|
||||||
|
queries_local: 0,
|
||||||
|
upstream_errors: 0,
|
||||||
|
started_at: Instant::now(),
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn record(&mut self, path: QueryPath) -> u64 {
|
||||||
|
self.queries_total += 1;
|
||||||
|
match path {
|
||||||
|
QueryPath::Local => self.queries_local += 1,
|
||||||
|
QueryPath::Cached => self.queries_cached += 1,
|
||||||
|
QueryPath::Forwarded => self.queries_forwarded += 1,
|
||||||
|
QueryPath::Blocked => self.queries_blocked += 1,
|
||||||
|
QueryPath::UpstreamError => self.upstream_errors += 1,
|
||||||
|
}
|
||||||
|
self.queries_total
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn total(&self) -> u64 {
|
||||||
|
self.queries_total
|
||||||
|
}
|
||||||
|
|
||||||
|
pub fn log_summary(&self) {
|
||||||
|
let uptime = self.started_at.elapsed();
|
||||||
|
let hours = uptime.as_secs() / 3600;
|
||||||
|
let mins = (uptime.as_secs() % 3600) / 60;
|
||||||
|
let secs = uptime.as_secs() % 60;
|
||||||
|
|
||||||
|
log::info!(
|
||||||
|
"STATS | uptime {}h{}m{}s | total {} | fwd {} | cached {} | local {} | blocked {} | errors {}",
|
||||||
|
hours, mins, secs,
|
||||||
|
self.queries_total,
|
||||||
|
self.queries_forwarded,
|
||||||
|
self.queries_cached,
|
||||||
|
self.queries_local,
|
||||||
|
self.queries_blocked,
|
||||||
|
self.upstream_errors,
|
||||||
|
);
|
||||||
|
}
|
||||||
|
}
|
||||||
Reference in New Issue
Block a user