MahnoKropotkinvich/smtp-filter
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

add filter rule

Browse Source
This commit is contained in:
Mahno 2025-04-15 18:27:54 +08:00
parent 28a768458b
commit 0a86ef3e98
1 changed files with 29 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

32
main.go
View File

@ -6,6 +6,7 @@ import (
"io"
"net"
"os"
"regexp"
"strings"
"sync"
"time"
@ -26,6 +27,8 @@ var (
serverTLSConf *tls.Config
)
var re = regexp.MustCompile(`^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$`)
type timeoutConn struct {
conn net.Conn
}
@ -132,7 +135,11 @@ func handleConnection(clientConn net.Conn) {
log.Infof("Connection upgraded to TLS for %s", smtp.clientAddr)
continue
}
if strings.HasPrefix(cmd, "AUTH") {
smtp.client.Write([]byte("554 5.7.1 Access denied\r\n"))
log.Warnf("Rejected recipient from %s: external auth denied", smtp.clientAddr)
return
}
// Handle RCPT TO validation inside TLS if needed
if strings.HasPrefix(cmd, "RCPT TO:") {
parts := strings.Split(strings.ToLower(line), ":")
@ -141,13 +148,32 @@ func handleConnection(clientConn net.Conn) {
return
}
email := strings.Trim(strings.TrimSpace(parts[1]), "<>")
// email := strings.Trim(strings.TrimSpace(parts[1]), "<>")
// domain := strings.Split(email, "@")
// if len(domain) != 2 {
// smtp.client.Write([]byte("501 Syntax error in parameters or arguments\r\n"))
// return
// }
// fmt.Sscanf(parts[1], "<%s>%s", &email, &whatever)
// email := re.FindStringSubmatch(parts[1])
// if len(email) < 1 {
// log.Errorf("%s is not email address", email[1])
// return
// }
// domain := strings.Split(email[0], "@")
start := strings.Index(parts[1], "<")
end := strings.Index(parts[1], ">")
if start == -1 || end == -1 || start >= end {
smtp.client.Write([]byte("501 Syntax error in parameters or arguments\r\n"))
return
}
email := parts[1][start+1 : end]
domain := strings.Split(email, "@")
if len(domain) != 2 {
smtp.client.Write([]byte("501 Syntax error in parameters or arguments\r\n"))
return
}
if domain[1] != allowDomain {
log.Warnf("Rejected recipient from %s: domain %s not allowed", smtp.clientAddr, domain[1])
smtp.client.Write([]byte("554 Domain not allowed\r\n"))