Add outbound proxy support for target in connectback mode

common.h

@@ -140,6 +140,13 @@
 #define ESCAPE_CR 1
 #define ESCAPE_TILDE 2
 
+/* Outbound proxy */
+#define OUTBOUND_PROXY_TYPE_NULL 0
+#define OUTBOUND_PROXY_TYPE_SOCKS4 1
+#define OUTBOUND_PROXY_TYPE_SOCKS4A 2
+#define OUTBOUND_PROXY_TYPE_SOCKS5 3
+#define OUTBOUND_PROXY_TYPE_SOCKS5H 4
+#define OUTBOUND_PROXY_TYPE_HTTP 5
 
 /******************************************************************************
  * global variables
@@ -254,6 +261,7 @@ void connection_node_delete(struct connection_node *);
 struct connection_node *connection_node_find(unsigned short origin, unsigned short id);
 void connection_node_queue(struct connection_node *cur_connection_node);
 int parse_socks_request(struct connection_node *cur_connection_node);
+int parse_addr_string(char *addr_string, unsigned char ip[4], unsigned short *port);
 char *addr_to_string(int atype, char *addr, char *port, int len);
 
 /* report.c */

config.h

@@ -10,6 +10,55 @@
 #define CONTROL_ADDRESS "0.0.0.0"
 #define CONTROL_PORT "2200"
 
+/*
+ * Outbound proxy for target
+ */
+
+// Default: no proxy
+#define OUTBOUND_PROXY_TYPE OUTBOUND_PROXY_TYPE_NULL
+#define OUTBOUND_PROXY_ADDR NULL
+#define OUTBOUND_PROXY_USERNAME NULL
+#define OUTBOUND_PROXY_PASSWORD NULL
+
+/* Examples */
+
+/* socks4 (CONTROL_ADDRESS must be ipv4 address) */
+// #define OUTBOUND_PROXY_TYPE OUTBOUND_PROXY_TYPE_SOCKS4
+// #define OUTBOUND_PROXY_ADDR "127.0.0.1:1080"
+// #define OUTBOUND_PROXY_USERNAME NULL
+// #define OUTBOUND_PROXY_PASSWORD NULL
+
+/* socks4a (CONTROL_ADDRESS can be domain to be resolved by the proxy) */
+// #define OUTBOUND_PROXY_TYPE OUTBOUND_PROXY_TYPE_SOCKS4A
+// #define OUTBOUND_PROXY_ADDR "127.0.0.1:1080"
+// #define OUTBOUND_PROXY_USERNAME NULL
+// #define OUTBOUND_PROXY_PASSWORD NULL
+
+/* socks5 (CONTROL_ADDRESS must be ipv4 address) */
+// #define OUTBOUND_PROXY_TYPE OUTBOUND_PROXY_TYPE_SOCKS5
+// #define OUTBOUND_PROXY_ADDR "127.0.0.1:1080"
+// #define OUTBOUND_PROXY_USERNAME NULL
+// #define OUTBOUND_PROXY_PASSWORD NULL
+
+/* socks5h (CONTROL_ADDRESS can be domain to be resolved by the proxy) */
+// #define OUTBOUND_PROXY_TYPE OUTBOUND_PROXY_TYPE_SOCKS5H
+// #define OUTBOUND_PROXY_ADDR "127.0.0.1:1080"
+// #define OUTBOUND_PROXY_USERNAME NULL
+// #define OUTBOUND_PROXY_PASSWORD NULL
+
+/* http (CONTROL_ADDRESS can be domain to be resolved by the proxy). Check proxy
+ * access control, for squid port 443 usually allowed */
+// #define OUTBOUND_PROXY_TYPE OUTBOUND_PROXY_TYPE_HTTP
+// #define OUTBOUND_PROXY_ADDR "127.0.0.1:3128"
+// #define OUTBOUND_PROXY_USERNAME NULL
+// #define OUTBOUND_PROXY_PASSWORD NULL
+
+/* proxy authentication (http/socks5/socks5h proxy only) */
+// #define OUTBOUND_PROXY_TYPE OUTBOUND_PROXY_TYPE_HTTP
+// #define OUTBOUND_PROXY_ADDR "127.0.0.1:3128"
+// #define OUTBOUND_PROXY_USERNAME "foo"
+// #define OUTBOUND_PROXY_PASSWORD "bar"
+
 // Default socks proxy listener port.
 #define SOCKS_LISTENER "2280"
 

helper_objects.h

@@ -55,6 +55,10 @@ struct config_helper {
 	int tap;
 
 	char *ip_addr;
+	int outbound_proxy_type;
+	char *outbound_proxy_addr;
+	char *outbound_proxy_username;
+	char *outbound_proxy_password;
 	char *keys_dir;
 	char *rc_file;
 	char *shell;