g3-dpi: add port for On-Demand Mail Relay protocol

doc/standards.md

@@ -300,6 +300,8 @@ The code should comply to these, but should be more compliant to existing popula
     : Simple Mail Transfer Protocol
  - [rfc6409](https://datatracker.ietf.org/doc/html/rfc6409)
     : Message Submission for Mail
+ - [rfc2645](https://datatracker.ietf.org/doc/html/rfc2645)
+    : ON-DEMAND MAIL RELAY (ODMR) SMTP with Dynamic IP Addresses
  - [rfc6152](https://datatracker.ietf.org/doc/html/rfc6152)
     : SMTP Service Extension for 8-bit MIME Transport
  - [rfc3030](https://datatracker.ietf.org/doc/html/rfc3030)

g3proxy/src/inspect/smtp/initiation.rs

@@ -197,6 +197,7 @@ impl Initiation {
                 "RRVS" => true,     // Require Recipient Valid Since, RFC7293, add a RCPT param key
                 "REQUIRETLS" => true, // Require TLS, RFC8689, add a MAIL param key
                 "LIMITS" => true,   // LIMITS, RFC9422
+                "ATRN" => true,     // On-Demand Mail Relay, RFC2645, change the protocol
                 _ => false,
             }
         }

lib/g3-dpi/src/protocol/bittorrent.rs

@@ -40,6 +40,7 @@ impl ProtocolInspectState {
         self.exclude_other(MaybeProtocol::Ftp);
         self.exclude_other(MaybeProtocol::Ssh);
         self.exclude_other(MaybeProtocol::Smtp);
+        self.exclude_other(MaybeProtocol::Odmr);
         self.exclude_other(MaybeProtocol::Pop3);
         self.exclude_other(MaybeProtocol::Imap);
         self.exclude_other(MaybeProtocol::Http);

lib/g3-dpi/src/protocol/ftp.rs

@@ -38,6 +38,7 @@ impl ProtocolInspectState {
                 // 0x31
                 self.ftp_exclude_by_byte0();
                 self.exclude_other(MaybeProtocol::Smtp);
+                self.exclude_other(MaybeProtocol::Odmr);
                 self.exclude_other(MaybeProtocol::Nntp);
 
                 if &data[0..3] == b"120" {
@@ -63,6 +64,7 @@ impl ProtocolInspectState {
                 // 0x34
                 self.ftp_exclude_by_byte0();
                 self.exclude_other(MaybeProtocol::Smtp);
+                self.exclude_other(MaybeProtocol::Odmr);
                 self.exclude_other(MaybeProtocol::Nntp);
 
                 if &data[0..3] == b"421" {

lib/g3-dpi/src/protocol/imap.rs

@@ -43,6 +43,7 @@ impl ProtocolInspectState {
         self.exclude_other(MaybeProtocol::Ftp);
         self.exclude_other(MaybeProtocol::Ssh);
         self.exclude_other(MaybeProtocol::Smtp);
+        self.exclude_other(MaybeProtocol::Odmr);
         self.exclude_other(MaybeProtocol::Pop3);
         self.exclude_other(MaybeProtocol::Nntp);
         self.exclude_other(MaybeProtocol::Nats);

lib/g3-dpi/src/protocol/inspect.rs

@@ -110,6 +110,7 @@ impl ProtocolInspectState {
             MaybeProtocol::BitTorrent => self.check_bittorrent_tcp_handshake(data),
             MaybeProtocol::Ftp
             | MaybeProtocol::Smtp
+            | MaybeProtocol::Odmr
             | MaybeProtocol::Pop3
             | MaybeProtocol::Nntp
             | MaybeProtocol::Nnsp
@@ -147,7 +148,7 @@ impl ProtocolInspectState {
         match proto {
             MaybeProtocol::Ftp => self.check_ftp_server_greeting(data, size_limit),
             MaybeProtocol::Ssh => self.check_ssh_server_protocol_version_exchange(data),
-            MaybeProtocol::Smtp => self.check_smtp_server_greeting(data),
+            MaybeProtocol::Smtp | MaybeProtocol::Odmr => self.check_smtp_server_greeting(data),
             MaybeProtocol::Pop3 => self.check_pop3_server_greeting(data),
             MaybeProtocol::Nntp | MaybeProtocol::Nnsp => self.check_nntp_server_greeting(data),
             MaybeProtocol::Imap => self.check_imap_server_greeting(data, size_limit),

lib/g3-dpi/src/protocol/mod.rs

@@ -31,6 +31,7 @@ pub use portmap::{ProtocolPortMap, ProtocolPortMapValue};
 pub enum MaybeProtocol {
     Http,
     Smtp,
+    Odmr, // On-Demand Mail Relay, a restricted profile of SMTP
     Ssh,
     Ftp,
     Dns,
@@ -88,6 +89,7 @@ impl FromStr for MaybeProtocol {
         match s.to_lowercase().as_str() {
             "http" => Ok(MaybeProtocol::Http),
             "smtp" => Ok(MaybeProtocol::Smtp),
+            "odmr" => Ok(MaybeProtocol::Odmr),
             "ssh" => Ok(MaybeProtocol::Ssh),
             "ftp" => Ok(MaybeProtocol::Ftp),
             "pop3" => Ok(MaybeProtocol::Pop3),

lib/g3-dpi/src/protocol/nats.rs

@@ -42,6 +42,7 @@ impl ProtocolInspectState {
         self.exclude_other(MaybeProtocol::Ftp);
         self.exclude_other(MaybeProtocol::Ssh);
         self.exclude_other(MaybeProtocol::Smtp);
+        self.exclude_other(MaybeProtocol::Odmr);
         self.exclude_other(MaybeProtocol::Pop3);
         self.exclude_other(MaybeProtocol::Nntp);
         self.exclude_other(MaybeProtocol::Imap);

lib/g3-dpi/src/protocol/nntp.rs

@@ -57,6 +57,7 @@ impl ProtocolInspectState {
         // exclude impossible protocols
         self.exclude_other(MaybeProtocol::Ftp);
         self.exclude_other(MaybeProtocol::Smtp);
+        self.exclude_other(MaybeProtocol::Odmr);
 
         if !matches!(data[2], b'0' | b'1') {
             self.exclude_current();

lib/g3-dpi/src/protocol/pop3.rs

@@ -46,6 +46,7 @@ impl ProtocolInspectState {
         self.exclude_other(MaybeProtocol::Ftp);
         self.exclude_other(MaybeProtocol::Ssh);
         self.exclude_other(MaybeProtocol::Smtp);
+        self.exclude_other(MaybeProtocol::Odmr);
         self.exclude_other(MaybeProtocol::Nntp);
         self.exclude_other(MaybeProtocol::Imap);
         self.exclude_other(MaybeProtocol::Nats);

lib/g3-dpi/src/protocol/portmap.rs

@@ -128,6 +128,7 @@ impl ProtocolPortMap {
         map.insert(119, MaybeProtocol::Nntp);
         map.insert(143, MaybeProtocol::Imap);
         map.insert(322, MaybeProtocol::Rtsps);
+        map.insert(366, MaybeProtocol::Odmr);
         map.insert(433, MaybeProtocol::Nnsp);
         map.insert(443, MaybeProtocol::Https);
         map.insert(465, MaybeProtocol::Submissions);

lib/g3-dpi/src/protocol/ssh.rs

@@ -118,6 +118,7 @@ impl ProtocolInspectState {
         // exclude impossible protocols
         self.exclude_other(MaybeProtocol::Ftp);
         self.exclude_other(MaybeProtocol::Smtp);
+        self.exclude_other(MaybeProtocol::Odmr);
         self.exclude_other(MaybeProtocol::Pop3);
         self.exclude_other(MaybeProtocol::Nntp);
         self.exclude_other(MaybeProtocol::Imap);