Merge pull request #7 from orware/master

Add Allowed Sender IPs/Ranges Functionality to MailRelay
This commit is contained in:
Doug Lauder
2025-05-24 16:20:51 -04:00
committed by GitHub
4 changed files with 59 additions and 0 deletions

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@ -27,11 +27,18 @@ func sendMail(e *mail.Envelope, config *relayConfig) error {
msg.WriteString("\r\n")
Logger.Infof("starting email send -- from:%s, starttls:%t", e.MailFrom.String(), config.STARTTLS)
Logger.Infof("Client Remote IP: %s", e.RemoteIP)
var err error
var conn net.Conn
var client *smtp.Client
var writer io.WriteCloser
if AllowedSendersFilter.Blocked(e.RemoteIP) {
Logger.Info("Remote IP of " + e.RemoteIP + " not allowed to send email.")
return errors.Wrap(err, "Remote IP of "+e.RemoteIP+" not allowed to send email.")
}
tlsconfig := &tls.Config{
InsecureSkipVerify: config.SkipVerify, //nolint:gosec
ServerName: config.Server,

1
go.mod
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@ -6,6 +6,7 @@ require (
github.com/asaskevich/EventBus v0.0.0-20180103000110-68a521d7cbbb // indirect
github.com/flashmob/go-guerrilla v1.6.1
github.com/go-sql-driver/mysql v1.5.0 // indirect
github.com/jpillora/ipfilter v1.2.2
github.com/kr/text v0.2.0 // indirect
github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e // indirect
github.com/pkg/errors v0.9.1

7
go.sum
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@ -8,6 +8,8 @@ github.com/flashmob/go-guerrilla v1.6.1 h1:MLkqzRFUJveVAWuQ3s2MNPTAWbvXLt8EFsBor
github.com/flashmob/go-guerrilla v1.6.1/go.mod h1:ZT9TRggRsSY4ZVndoyx8TRUxi3tM/nOYtKWKDX94H0I=
github.com/go-sql-driver/mysql v1.5.0 h1:ozyZYNQW3x3HtqT1jira07DN2PArx2v7/mN66gGcHOs=
github.com/go-sql-driver/mysql v1.5.0/go.mod h1:DCzpHaOWr8IXmIStZouvnhqoel9Qv2LBy8hT2VhHyBg=
github.com/jpillora/ipfilter v1.2.2 h1:lfENG7V1/T+ZutAtSbt6gssvzj3Ql0JmcFlqS/BES2E=
github.com/jpillora/ipfilter v1.2.2/go.mod h1:xvAYjA+48eM9E5+sg9yI55N5lE9sefckjsnDvSiEA+g=
github.com/konsorten/go-windows-terminal-sequences v1.0.3 h1:CE8S1cTafDpPvMhIxNJKvHsGVBgn1xWYf1NbHQhywc8=
github.com/konsorten/go-windows-terminal-sequences v1.0.3/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
@ -16,6 +18,8 @@ github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e h1:fD57ERR4JtEqsWbfPhv4DMiApHyliiK5xCTNVSPiaAs=
github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e/go.mod h1:zD1mROLANZcx1PVRCS0qkT7pwLkGfwJo4zjcN/Tysno=
github.com/phuslu/iploc v1.0.20200807 h1:LIBm2Y9l5zmUvnJhQgMcLZ0iVwuG+5/L6AgbMwSOpE4=
github.com/phuslu/iploc v1.0.20200807/go.mod h1:Q/0VX0txvbxekt4NhWIi3Q3eyZ139lHhnlzvDxyXhuc=
github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
@ -24,8 +28,11 @@ github.com/sirupsen/logrus v1.6.0 h1:UBcNElsrwanuuMsnGSlYmtmgbb23qDR5dG+6X6Oo89I
github.com/sirupsen/logrus v1.6.0/go.mod h1:7uNnSEd1DgxDLC74fIahvMZmmYsHGZGEOFrfsX/uA88=
github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
github.com/stretchr/testify v1.5.1 h1:nOGnQDM7FYENwehXlg/kFVnos3rEvtKTjRvOWSzb6H4=
github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
github.com/tomasen/realip v0.0.0-20180522021738-f0c99a92ddce h1:fb190+cK2Xz/dvi9Hv8eCYJYvIGUTN2/KLq1pT6CjEc=
github.com/tomasen/realip v0.0.0-20180522021738-f0c99a92ddce/go.mod h1:o8v6yHRoik09Xen7gje4m9ERNah1d1PPsVq1VEx9vE4=
golang.org/x/sys v0.0.0-20190422165155-953cdadca894/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/sys v0.1.0 h1:kunALQeHf1/185U1i0GOB/fy1IPRDDpuoOOqRReG57U=
golang.org/x/sys v0.1.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=

44
main.go
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@ -1,6 +1,7 @@
package main
import (
"bufio"
"encoding/json"
"flag"
"fmt"
@ -10,6 +11,7 @@ import (
"syscall"
log "github.com/flashmob/go-guerrilla/log"
"github.com/jpillora/ipfilter"
)
const (
@ -23,6 +25,9 @@ const (
// Logger is the global logger
var Logger log.Logger
// Global List of Allowed Sender IPs:
var AllowedSendersFilter = ipfilter.New(ipfilter.Options{})
type mailRelayConfig struct {
SMTPServer string `json:"smtp_server"`
SMTPPort int `json:"smtp_port"`
@ -36,6 +41,7 @@ type mailRelayConfig struct {
LocalListenIP string `json:"local_listen_ip"`
LocalListenPort int `json:"local_listen_port"`
AllowedHosts []string `json:"allowed_hosts"`
AllowedSenders string `json:"allowed_senders"`
TimeoutSecs int `json:"timeout_secs"`
}
@ -53,12 +59,16 @@ func run() error {
var test bool
var testsender string
var testrcpt string
var checkIP bool
var ipToCheck string
var verbose bool
flag.StringVar(&configFile, "config", "/etc/mailrelay.json", "specifies JSON config file")
flag.BoolVar(&test, "test", false, "sends a test message to SMTP server")
flag.StringVar(&testsender, "sender", "", "used with 'test' to specify sender email address")
flag.StringVar(&testrcpt, "rcpt", "", "used with 'test' to specify recipient email address")
flag.BoolVar(&verbose, "verbose", false, "verbose output")
flag.BoolVar(&checkIP, "checkIP", false, "Checks a provided IP address to see if it would be allowed")
flag.StringVar(&ipToCheck, "ip", "", "used with 'checkIP' to specify IP address to test")
flag.Parse()
appConfig, err := loadConfig(configFile)
@ -67,6 +77,34 @@ func run() error {
return fmt.Errorf("loading config: %w", err)
}
if appConfig.AllowedSenders != "*" {
file, err := os.Open(appConfig.AllowedSenders)
if err != nil {
return fmt.Errorf("failed opening file: %s", err)
}
scanner := bufio.NewScanner(file)
scanner.Split(bufio.ScanLines)
var allowedIPsAndRanges []string
for scanner.Scan() {
allowedIPsAndRanges = append(allowedIPsAndRanges, scanner.Text())
}
file.Close()
for _, eachline := range allowedIPsAndRanges {
fmt.Println(eachline)
}
AllowedSendersFilter = ipfilter.New(ipfilter.Options{
//AllowedIPs: []string{"192.168.0.0/24"},
AllowedIPs: allowedIPsAndRanges,
BlockByDefault: true,
})
}
err = Start(appConfig, verbose)
if err != nil {
flag.Usage()
@ -90,6 +128,11 @@ func run() error {
return nil
}
if checkIP {
Logger.Infof("Checking to see if %s is allowed to send email: %t", ipToCheck, AllowedSendersFilter.Allowed(ipToCheck))
return nil
}
// Wait for SIGINT
c := make(chan os.Signal, 1)
signal.Notify(c, os.Interrupt, syscall.SIGTERM)
@ -125,6 +168,7 @@ func configDefaults(config *mailRelayConfig) {
config.LocalListenIP = DefaultLocalListenIP
config.LocalListenPort = DefaultLocalListenPort
config.AllowedHosts = []string{"*"}
config.AllowedSenders = "*"
config.TimeoutSecs = DefaultTimeoutSecs
}