initial commit
This commit is contained in:
commit
f28bfd0ace
7 changed files with 358 additions and 0 deletions
4
.envrc
Normal file
4
.envrc
Normal file
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@ -0,0 +1,4 @@
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if ! has nix_direnv_version || ! nix_direnv_version 2.2.0; then
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source_url "https://raw.githubusercontent.com/nix-community/nix-direnv/2.2.0/direnvrc" "sha256-5EwyKnkJNQeXrRkYbwwRBcXbibosCJqyIUuz9Xq+LRc="
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fi
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use flake
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12
cmd/inbound/inbound.go
Normal file
12
cmd/inbound/inbound.go
Normal file
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@ -0,0 +1,12 @@
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package main
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import "flag"
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var listenPort int
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func init() {
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flag.IntVar(&listenPort, "p", 2525, "port on which to listen for incoming emails")
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}
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func main() {
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}
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61
flake.lock
Normal file
61
flake.lock
Normal file
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@ -0,0 +1,61 @@
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{
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"nodes": {
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"flake-utils": {
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"inputs": {
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"systems": "systems"
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},
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"locked": {
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"lastModified": 1681202837,
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"narHash": "sha256-H+Rh19JDwRtpVPAWp64F+rlEtxUWBAQW28eAi3SRSzg=",
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"owner": "numtide",
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"repo": "flake-utils",
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"rev": "cfacdce06f30d2b68473a46042957675eebb3401",
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"type": "github"
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},
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"original": {
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"owner": "numtide",
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"repo": "flake-utils",
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"type": "github"
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}
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},
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"nixpkgs": {
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"locked": {
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"lastModified": 1683627095,
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"narHash": "sha256-8u9SejRpL2TrMuHBdhYh4FKc1OGPDLyWTpIbNTtoHsA=",
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"owner": "nixos",
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"repo": "nixpkgs",
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"rev": "a08e061a4ee8329747d54ddf1566d34c55c895eb",
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"type": "github"
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},
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"original": {
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"owner": "nixos",
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"ref": "nixos-22.11",
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"repo": "nixpkgs",
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"type": "github"
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}
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},
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"root": {
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"inputs": {
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"flake-utils": "flake-utils",
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"nixpkgs": "nixpkgs"
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}
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},
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"systems": {
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"locked": {
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"lastModified": 1681028828,
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"narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
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"owner": "nix-systems",
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"repo": "default",
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"rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
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"type": "github"
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},
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"original": {
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"owner": "nix-systems",
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"repo": "default",
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"type": "github"
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}
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}
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},
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"root": "root",
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"version": 7
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}
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52
flake.nix
Normal file
52
flake.nix
Normal file
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@ -0,0 +1,52 @@
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{
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description = "tkcli devshell";
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inputs = {
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nixpkgs.url = "github:nixos/nixpkgs/nixos-22.11";
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#nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable"; # localstack is broken right now (2023-01-25) in unstable, due to a missing dependency
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flake-utils.url = "github:numtide/flake-utils";
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};
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outputs = { self, nixpkgs, flake-utils, ... }@inputs:
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flake-utils.lib.eachDefaultSystem (system:
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let
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pkgs = nixpkgs.legacyPackages.${system};
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gci = pkgs.buildGoModule rec {
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name = "gci";
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src = pkgs.fetchFromGitHub {
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owner = "daixiang0";
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repo = "gci";
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rev = "v0.10.1";
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sha256 = "sha256-/YR61lovuYw+GEeXIgvyPbesz2epmQVmSLWjWwKT4Ag=";
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};
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# Switch to fake vendor sha for upgrades:
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#vendorSha256 = pkgs.lib.fakeSha256;
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vendorSha256 = "sha256-g7htGfU6C2rzfu8hAn6SGr0ZRwB8ZzSf9CgHYmdupE8=";
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};
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cclint = pkgs.writeScriptBin "lint" ''
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#!/bin/sh
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pushd $(git rev-parse --show-toplevel)/
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${pkgs.go}/bin/go mod tidy
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${pkgs.gofumpt}/bin/gofumpt -w *.go ./cmd/*
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${gci}/bin/gci write --skip-generated -s standard -s default -s "Prefix(git.cycore.io/cycore)" .
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${pkgs.golangci-lint}/bin/golangci-lint run ./...
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${pkgs.go}/bin/go test -v ./...
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'';
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in
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{
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devShells.default = pkgs.mkShell {
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packages = with pkgs; [
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bashInteractive
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envsubst
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gci
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gofumpt
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golangci-lint
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go
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go-tools
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cclint
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];
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};
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});
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}
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17
go.mod
Normal file
17
go.mod
Normal file
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@ -0,0 +1,17 @@
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module git.cycore.io/cycore/mail
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go 1.20
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require (
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github.com/emersion/go-imap v1.2.1 // indirect
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github.com/emersion/go-message v0.16.0 // indirect
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github.com/emersion/go-milter v0.3.3 // indirect
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github.com/emersion/go-sasl v0.0.0-20200509203442-7bfe0ed36a21 // indirect
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github.com/emersion/go-smtp v0.16.0 // indirect
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github.com/emersion/go-textwrapper v0.0.0-20200911093747-65d896831594 // indirect
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go.uber.org/atomic v1.7.0 // indirect
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go.uber.org/multierr v1.6.0 // indirect
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go.uber.org/zap v1.24.0 // indirect
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golang.org/x/text v0.3.7 // indirect
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golang.org/x/time v0.3.0 // indirect
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)
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35
go.sum
Normal file
35
go.sum
Normal file
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@ -0,0 +1,35 @@
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github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
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github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
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github.com/emersion/go-imap v1.2.1 h1:+s9ZjMEjOB8NzZMVTM3cCenz2JrQIGGo5j1df19WjTA=
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github.com/emersion/go-imap v1.2.1/go.mod h1:Qlx1FSx2FTxjnjWpIlVNEuX+ylerZQNFE5NsmKFSejY=
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github.com/emersion/go-message v0.11.2/go.mod h1:C4jnca5HOTo4bGN9YdqNQM9sITuT3Y0K6bSUw9RklvY=
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github.com/emersion/go-message v0.15.0 h1:urgKGqt2JAc9NFJcgncQcohHdiYb803YTH9OQwHBHIY=
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github.com/emersion/go-message v0.15.0/go.mod h1:wQUEfE+38+7EW8p8aZ96ptg6bAb1iwdgej19uXASlE4=
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github.com/emersion/go-message v0.16.0 h1:uZLz8ClLv3V5fSFF/fFdW9jXjrZkXIpE1Fn8fKx7pO4=
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github.com/emersion/go-message v0.16.0/go.mod h1:pDJDgf/xeUIF+eicT6B/hPX/ZbEorKkUMPOxrPVG2eQ=
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github.com/emersion/go-milter v0.3.3 h1:DiP9Xmw2FqEuosNCd01XPDBb1K3OziNmt7BG2ddFlgs=
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github.com/emersion/go-milter v0.3.3/go.mod h1:ablHK0pbLB83kMFBznp/Rj8aV+Kc3jw8cxzzmCNLIOY=
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github.com/emersion/go-sasl v0.0.0-20200509203442-7bfe0ed36a21 h1:OJyUGMJTzHTd1XQp98QTaHernxMYzRaOasRir9hUlFQ=
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github.com/emersion/go-sasl v0.0.0-20200509203442-7bfe0ed36a21/go.mod h1:iL2twTeMvZnrg54ZoPDNfJaJaqy0xIQFuBdrLsmspwQ=
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github.com/emersion/go-smtp v0.16.0 h1:eB9CY9527WdEZSs5sWisTmilDX7gG+Q/2IdRcmubpa8=
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github.com/emersion/go-smtp v0.16.0/go.mod h1:qm27SGYgoIPRot6ubfQ/GpiPy/g3PaZAVRxiO/sDUgQ=
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github.com/emersion/go-textwrapper v0.0.0-20160606182133-d0e65e56babe/go.mod h1:aqO8z8wPrjkscevZJFVE1wXJrLpC5LtJG7fqLOsPb2U=
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github.com/emersion/go-textwrapper v0.0.0-20200911093747-65d896831594 h1:IbFBtwoTQyw0fIM5xv1HF+Y+3ZijDR839WMulgxCcUY=
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github.com/emersion/go-textwrapper v0.0.0-20200911093747-65d896831594/go.mod h1:aqO8z8wPrjkscevZJFVE1wXJrLpC5LtJG7fqLOsPb2U=
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github.com/martinlindhe/base36 v1.0.0/go.mod h1:+AtEs8xrBpCeYgSLoY/aJ6Wf37jtBuR0s35750M27+8=
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github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
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github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
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github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
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go.uber.org/atomic v1.7.0 h1:ADUqmZGgLDDfbSL9ZmPxKTybcoEYHgpYfELNoN+7hsw=
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go.uber.org/atomic v1.7.0/go.mod h1:fEN4uk6kAWBTFdckzkM89CLk9XfWZrxpCo0nPH17wJc=
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go.uber.org/multierr v1.6.0 h1:y6IPFStTAIT5Ytl7/XYmHvzXQ7S3g/IeZW9hyZ5thw4=
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go.uber.org/multierr v1.6.0/go.mod h1:cdWPpRnG4AhwMwsgIHip0KRBQjJy5kYEpYjJxpXp9iU=
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go.uber.org/zap v1.24.0 h1:FiJd5l1UOLj0wCgbSE0rwwXHzEdAZS6hiiSnxJN/D60=
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go.uber.org/zap v1.24.0/go.mod h1:2kMP+WWQ8aoFoedH3T2sq6iJ2yDWpHbP0f6MQbS9Gkg=
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golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
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golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
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golang.org/x/text v0.3.7 h1:olpwvP2KacW1ZWvsR7uQhoyTYvKAupfQrRGBFM352Gk=
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golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
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golang.org/x/time v0.3.0 h1:rg5rLMjNzMS1RkNLzCG38eapWhnYLFYXDXj2gOlr8j4=
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golang.org/x/time v0.3.0/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
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golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
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177
server/server.go
Normal file
177
server/server.go
Normal file
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@ -0,0 +1,177 @@
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package server
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import (
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"context"
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"fmt"
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"io"
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"strings"
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"time"
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"github.com/emersion/go-message/mail"
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"github.com/emersion/go-milter"
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"github.com/emersion/go-smtp"
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"go.uber.org/zap"
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"golang.org/x/time/rate"
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)
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const ConnectionTimeout = 3 * time.Minute
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// ErrRateLimit indicates that the message is rejected due to a rate limit.
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var ErrRateLimit = &smtp.SMTPError{
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Code: 450,
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EnhancedCode: [3]int{4, 2, 0},
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Message: "too many requests",
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}
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// ErrBadGateway indicates a downstream system failure.
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var ErrBadGateway = &smtp.SMTPError{
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Code: 451,
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EnhancedCode: [3]int{4, 4, 3},
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Message: "bad gateway",
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}
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// Backend provides a backend implementation of an SMTP server.
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type Backend struct {
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AllowedDomains []string
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Log *zap.Logger
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RootContext context.Context
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RSpam *milter.Client
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OverallLimiter *rate.Limiter
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}
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// NewSession implements smtp.Backend
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func (b *Backend) NewSession(conn *smtp.Conn) (smtp.Session, error) {
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ctx, cancel := context.WithTimeout(b.RootContext, ConnectionTimeout)
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defer cancel()
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if err := b.OverallLimiter.Wait(ctx); err != nil {
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return nil, ErrRateLimit
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}
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rs, err := b.RSpam.Session()
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if err != nil {
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return nil, ErrBadGateway
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}
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return &Session{
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b: b,
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conn: conn,
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rspam: rs,
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}, nil
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}
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// Session provides an implementation of an SMTP session.
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type Session struct {
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b *Backend
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conn *smtp.Conn
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rspam *milter.ClientSession
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}
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// Discard currently processed message.
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func (session *Session) Reset() {
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panic("not implemented") // TODO: Implement
|
||||
}
|
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|
||||
// Free all resources associated with session.
|
||||
func (session *Session) Logout() error {
|
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panic("not implemented") // TODO: Implement
|
||||
}
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|
||||
// Authenticate the user using SASL PLAIN.
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func (session *Session) AuthPlain(username string, password string) error {
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return smtp.ErrAuthUnsupported
|
||||
}
|
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|
||||
// Set return path for currently processed message.
|
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func (session *Session) Mail(from string, opts *smtp.MailOptions) error {
|
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action, err := session.rspam.Mail(from, nil)
|
||||
if err != nil {
|
||||
return fmt.Errorf("filter failure: %w", err)
|
||||
}
|
||||
|
||||
return parseAction(action)
|
||||
}
|
||||
|
||||
// Add recipient for currently processed message.
|
||||
func (session *Session) Rcpt(to string) error {
|
||||
if err := session.validateDomain(to); err != nil {
|
||||
return &smtp.SMTPError{
|
||||
Code: 550,
|
||||
EnhancedCode: [3]int{5, 1, 2},
|
||||
Message: err.Error(),
|
||||
}
|
||||
}
|
||||
|
||||
action, err := session.rspam.Rcpt(to, nil)
|
||||
if err != nil {
|
||||
return fmt.Errorf("filter failure: %w", err)
|
||||
}
|
||||
|
||||
return parseAction(action)
|
||||
}
|
||||
|
||||
// Set currently processed message contents and send it.
|
||||
//
|
||||
// r must be consumed before Data returns.
|
||||
func (session *Session) Data(r io.Reader) error {
|
||||
// TODO: handle the modifyAction below, whatever it is.
|
||||
_, action, err := session.rspam.BodyReadFrom(r)
|
||||
if err != nil {
|
||||
return fmt.Errorf("filter failure: %w", err)
|
||||
}
|
||||
|
||||
return parseAction(action)
|
||||
}
|
||||
|
||||
func (session *Session) validateDomain(to string) error {
|
||||
toAddr, err := mail.ParseAddress(to)
|
||||
if err != nil {
|
||||
return fmt.Errorf("failed to parse address: %w", err)
|
||||
}
|
||||
|
||||
pieces := strings.Split(toAddr.Address, "@")
|
||||
if len(pieces) != 2 {
|
||||
return fmt.Errorf("invalid address")
|
||||
}
|
||||
|
||||
for _, d := range session.b.AllowedDomains {
|
||||
if strings.Contains(pieces[2], d) {
|
||||
return nil
|
||||
}
|
||||
}
|
||||
|
||||
return fmt.Errorf("invalid domain")
|
||||
}
|
||||
|
||||
func parseAction(action *milter.Action) error {
|
||||
switch action.Code {
|
||||
case milter.ActAccept:
|
||||
return nil
|
||||
case milter.ActContinue:
|
||||
return nil
|
||||
case milter.ActDiscard:
|
||||
return milterReject(action)
|
||||
case milter.ActReject:
|
||||
return milterReject(action)
|
||||
case milter.ActTempFail:
|
||||
return milterReject(action)
|
||||
case milter.ActReplyCode:
|
||||
return milterReject(action)
|
||||
case milter.ActSkip:
|
||||
return milterReject(action)
|
||||
}
|
||||
|
||||
return fmt.Errorf("unhandled action code %q", action.Code)
|
||||
}
|
||||
|
||||
func milterReject(action *milter.Action) error {
|
||||
return &smtp.SMTPError{
|
||||
Code: action.SMTPCode,
|
||||
EnhancedCode: [3]int{4, 2, 0},
|
||||
Message: action.SMTPText,
|
||||
}
|
||||
}
|
||||
Loading…
Reference in a new issue