1 files changed, 123 insertions, 0 deletions
diff --git a/tools/plink/proxy.h b/tools/plink/proxy.h
new file mode 100644
index 000000000..683b2603d
--- /dev/null
+++ b/tools/plink/proxy.h
@@ -0,0 +1,123 @@
+/*
+ * Network proxy abstraction in PuTTY
+ *
+ * A proxy layer, if necessary, wedges itself between the
+ * network code and the higher level backend.
+ *
+ * Supported proxies: HTTP CONNECT, generic telnet, SOCKS 4 & 5
+ */
+
+#ifndef PUTTY_PROXY_H
+#define PUTTY_PROXY_H
+
+#define PROXY_ERROR_GENERAL 8000
+#define PROXY_ERROR_UNEXPECTED 8001
+
+typedef struct Socket_proxy_tag * Proxy_Socket;
+
+struct Socket_proxy_tag {
+    const struct socket_function_table *fn;
+    /* the above variable absolutely *must* be the first in this structure */
+
+    char * error;
+
+    Socket sub_socket;
+    Plug plug;
+    SockAddr remote_addr;
+    int remote_port;
+
+    bufchain pending_output_data;
+    bufchain pending_oob_output_data;
+    int pending_flush;
+    bufchain pending_input_data;
+
+#define PROXY_STATE_NEW    -1
+#define PROXY_STATE_ACTIVE  0
+
+    int state; /* proxy states greater than 0 are implementation
+		* dependent, but represent various stages/states
+		* of the initialization/setup/negotiation with the
+		* proxy server.
+		*/
+    int freeze; /* should we freeze the underlying socket when
+		 * we are done with the proxy negotiation? this
+		 * simply caches the value of sk_set_frozen calls.
+		 */
+
+#define PROXY_CHANGE_NEW      -1
+#define PROXY_CHANGE_CLOSING   0
+#define PROXY_CHANGE_SENT      1
+#define PROXY_CHANGE_RECEIVE   2
+#define PROXY_CHANGE_ACCEPTING 3
+
+    /* something has changed (a call from the sub socket
+     * layer into our Proxy Plug layer, or we were just
+     * created, etc), so the proxy layer needs to handle
+     * this change (the type of which is the second argument)
+     * and further the proxy negotiation process.
+     */
+
+    int (*negotiate) (Proxy_Socket /* this */, int /* change type */);
+
+    /* current arguments of plug handlers
+     * (for use by proxy's negotiate function)
+     */
+
+    /* closing */
+    const char *closing_error_msg;
+    int closing_error_code;
+    int closing_calling_back;
+
+    /* receive */
+    int receive_urgent;
+    char *receive_data;
+    int receive_len;
+
+    /* sent */
+    int sent_bufsize;
+
+    /* accepting */
+    OSSocket accepting_sock;
+
+    /* configuration, used to look up proxy settings */
+    Config cfg;
+
+    /* CHAP transient data */
+    int chap_num_attributes;
+    int chap_num_attributes_processed;
+    int chap_current_attribute;
+    int chap_current_datalen;
+};
+
+typedef struct Plug_proxy_tag * Proxy_Plug;
+
+struct Plug_proxy_tag {
+    const struct plug_function_table *fn;
+    /* the above variable absolutely *must* be the first in this structure */
+
+    Proxy_Socket proxy_socket;
+
+};
+
+extern void proxy_activate (Proxy_Socket);
+
+extern int proxy_http_negotiate (Proxy_Socket, int);
+extern int proxy_telnet_negotiate (Proxy_Socket, int);
+extern int proxy_socks4_negotiate (Proxy_Socket, int);
+extern int proxy_socks5_negotiate (Proxy_Socket, int);
+
+/*
+ * This may be reused by local-command proxies on individual
+ * platforms.
+ */
+char *format_telnet_command(SockAddr addr, int port, const Config *cfg);
+
+/*
+ * These are implemented in cproxy.c or nocproxy.c, depending on
+ * whether encrypted proxy authentication is available.
+ */
+extern void proxy_socks5_offerencryptedauth(char *command, int *len);
+extern int proxy_socks5_handlechap (Proxy_Socket p);
+extern int proxy_socks5_selectchap(Proxy_Socket p);
+
+#endif