Replacing port 25 to 587 for SMTP protocol

commands.c

@@ -736,6 +736,8 @@ static struct mobile_packet *command_change_clock(struct mobile_adapter *adapter
     // Replying with a different command in the header tricks the official GBA
     // library into never changing its serial mode. Using the REINIT command
     // forces it to set its serial mode to 8-bit.
+    mobile_debug_print(adapter, PSTR("<NO32BIT> Forcing adapter to keep using 8-bit mode!"));
+    mobile_debug_endl(adapter);
     packet->command = MOBILE_COMMAND_REINIT;
     s->mode_32bit = false;
 #endif
@@ -882,7 +884,8 @@ enum process_tcp_connect {
 };
 
 enum procdata_tcp_connect {
-    PROCDATA_TCP_CONNECT_CONN
+    PROCDATA_TCP_CONNECT_CONN,
+    PROCDATA_TCP_CONNECT_FALLBACK
 };
 
 static struct mobile_packet *command_tcp_connect_begin(struct mobile_adapter *adapter, struct mobile_packet *packet)
@@ -904,6 +907,15 @@ static struct mobile_packet *command_tcp_connect_begin(struct mobile_adapter *ad
     }
     s->connections[conn] = true;
 
+    b->processing_data[PROCDATA_TCP_CONNECT_FALLBACK] = 1;
+    if (adapter->config.mail_port) {
+        if ((packet->data[4] << 8 | packet->data[5]) == 25) {
+            mobile_debug_print(adapter, PSTR("<SMTP> Replacing port 25 to 587!"));
+            mobile_debug_endl(adapter);
+            b->processing_data[PROCDATA_TCP_CONNECT_FALLBACK] = 0;
+        }
+    }
+
     b->processing_data[PROCDATA_TCP_CONNECT_CONN] = conn;
     b->processing = PROCESS_TCP_CONNECT_CONNECTING;
     return NULL;
@@ -920,15 +932,42 @@ static struct mobile_packet *command_tcp_connect_connecting(struct mobile_adapte
         .type = MOBILE_ADDRTYPE_IPV4,
         .port = packet->data[4] << 8 | packet->data[5],
     };
+
+    if (adapter->config.mail_port) {
+        if (!b->processing_data[PROCDATA_TCP_CONNECT_FALLBACK]) {
+            if (addr.port == 25) addr.port = 587;
+        } 
+    }
+
     memcpy(addr.host, packet->data, 4);
 
     int rc = mobile_cb_sock_connect(adapter, conn,
         (struct mobile_addr *)&addr);
     if (rc == 0) return NULL;
     if (rc < 0) {
-        mobile_cb_sock_close(adapter, conn);
-        s->connections[conn] = false;
-        return error_packet(packet, 3);
+
+        if (!b->processing_data[PROCDATA_TCP_CONNECT_FALLBACK]) {
+            mobile_debug_print(adapter, PSTR("<SMTP> Failed to connect to port 587, trying port 25!"));
+            mobile_debug_endl(adapter);
+
+            mobile_cb_sock_close(adapter, conn);
+            if (!mobile_cb_sock_open(adapter, conn, MOBILE_SOCKTYPE_TCP,
+                    MOBILE_ADDRTYPE_IPV4, 0)) {
+                s->connections[conn] = false;
+                return error_packet(packet, 3);
+            }
+
+            b->processing_data[PROCDATA_TCP_CONNECT_FALLBACK] = 1;
+            addr.port = 25;
+            rc = mobile_cb_sock_connect(adapter, conn, (struct mobile_addr *)&addr);
+            if (rc == 0) return NULL;
+        }
+
+        if (rc < 0) {
+            mobile_cb_sock_close(adapter, conn);
+            s->connections[conn] = false;
+            return error_packet(packet, 3);
+        }
     }
 
     packet->data[0] = conn;

config.c

@@ -107,6 +107,7 @@ static bool config_library_load(struct mobile_adapter *adapter)
     config->p2p_port |= buffer[0x09] << 8;
     config->relay.type = buffer[0x0a];
     config->relay_token_init = buffer[0x0b];
+    config->mail_port = buffer[0x0c];
 
     if (!config_check_addrtype(config->dns1.type)) return false;
     if (!config_check_addrtype(config->dns2.type)) return false;
@@ -159,8 +160,9 @@ static void config_library_save(struct mobile_adapter *adapter)
     buffer[0x09] = config->p2p_port >> 8;
     buffer[0x0a] = config->relay.type;
     buffer[0x0b] = config->relay_token_init;
+    buffer[0x0c] = config->mail_port;
 
-    // 0x0c - 0x19 unused
+    // 0x0d - 0x19 unused
 
     config_library_save_host(&config->dns1, buffer + 0x20, buffer + 0x1a);
     config_library_save_host(&config->dns2, buffer + 0x30, buffer + 0x1c);
@@ -191,6 +193,7 @@ void mobile_config_init(struct mobile_adapter *adapter)
     adapter->config.p2p_port = MOBILE_DEFAULT_P2P_PORT;
     adapter->config.relay = (struct mobile_addr){.type = MOBILE_ADDRTYPE_NONE};
     adapter->config.relay_token_init = false;
+    adapter->config.mail_port = true;
     memset(adapter->config.relay_token, 0, MOBILE_RELAY_TOKEN_SIZE);
 }
 
@@ -307,3 +310,14 @@ bool mobile_config_get_relay_token(struct mobile_adapter *adapter, unsigned char
     memcpy(token, adapter->config.relay_token, MOBILE_RELAY_TOKEN_SIZE);
     return true;
 }
+
+void mobile_config_set_alt_mail(struct mobile_adapter *adapter, bool alt_mail) 
+{
+    adapter->config.mail_port = alt_mail;
+    mobile_config_apply(adapter);
+}
+
+void mobile_config_get_alt_mail(struct mobile_adapter *adapter, bool *alt_mail) 
+{
+    *alt_mail = adapter->config.mail_port;
+}

config.h

@@ -34,6 +34,9 @@ struct mobile_adapter_config {
     //   for p2p communication, instead of direct TCP connections
     struct mobile_addr relay;
 
+    // Makes the adapter use port 587 instead 25 for SMTP connections.
+    bool mail_port: 1;
+
     // Authentication token used for relay connections
     unsigned char relay_token[MOBILE_RELAY_TOKEN_SIZE];
 };

mobile.h

@@ -426,6 +426,8 @@ void mobile_config_set_relay(struct mobile_adapter *adapter, const struct mobile
 void mobile_config_get_relay(struct mobile_adapter *adapter, struct mobile_addr *relay);
 void mobile_config_set_relay_token(struct mobile_adapter *adapter, const unsigned char *token);
 bool mobile_config_get_relay_token(struct mobile_adapter *adapter, unsigned char *token);
+void mobile_config_set_alt_mail(struct mobile_adapter *adapter, bool alt_mail);
+void mobile_config_get_alt_mail(struct mobile_adapter *adapter, bool *alt_mail);
 
 // mobile_config_load - Manually force a load of the configuration values
 //